| 1 | /* Low level interface to ptrace, for the remote server for GDB. |
| 2 | Copyright (C) 1995-2019 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GDB. |
| 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 3 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | #include "server.h" |
| 20 | #include "linux-low.h" |
| 21 | #include "nat/linux-osdata.h" |
| 22 | #include "gdbsupport/agent.h" |
| 23 | #include "tdesc.h" |
| 24 | #include "gdbsupport/rsp-low.h" |
| 25 | #include "gdbsupport/signals-state-save-restore.h" |
| 26 | #include "nat/linux-nat.h" |
| 27 | #include "nat/linux-waitpid.h" |
| 28 | #include "gdbsupport/gdb_wait.h" |
| 29 | #include "nat/gdb_ptrace.h" |
| 30 | #include "nat/linux-ptrace.h" |
| 31 | #include "nat/linux-procfs.h" |
| 32 | #include "nat/linux-personality.h" |
| 33 | #include <signal.h> |
| 34 | #include <sys/ioctl.h> |
| 35 | #include <fcntl.h> |
| 36 | #include <unistd.h> |
| 37 | #include <sys/syscall.h> |
| 38 | #include <sched.h> |
| 39 | #include <ctype.h> |
| 40 | #include <pwd.h> |
| 41 | #include <sys/types.h> |
| 42 | #include <dirent.h> |
| 43 | #include <sys/stat.h> |
| 44 | #include <sys/vfs.h> |
| 45 | #include <sys/uio.h> |
| 46 | #include "gdbsupport/filestuff.h" |
| 47 | #include "tracepoint.h" |
| 48 | #include "hostio.h" |
| 49 | #include <inttypes.h> |
| 50 | #include "gdbsupport/common-inferior.h" |
| 51 | #include "nat/fork-inferior.h" |
| 52 | #include "gdbsupport/environ.h" |
| 53 | #include "gdbsupport/scoped_restore.h" |
| 54 | #ifndef ELFMAG0 |
| 55 | /* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h |
| 56 | then ELFMAG0 will have been defined. If it didn't get included by |
| 57 | gdb_proc_service.h then including it will likely introduce a duplicate |
| 58 | definition of elf_fpregset_t. */ |
| 59 | #include <elf.h> |
| 60 | #endif |
| 61 | #include "nat/linux-namespaces.h" |
| 62 | |
| 63 | #ifdef HAVE_PERSONALITY |
| 64 | # include <sys/personality.h> |
| 65 | # if !HAVE_DECL_ADDR_NO_RANDOMIZE |
| 66 | # define ADDR_NO_RANDOMIZE 0x0040000 |
| 67 | # endif |
| 68 | #endif |
| 69 | |
| 70 | #ifndef O_LARGEFILE |
| 71 | #define O_LARGEFILE 0 |
| 72 | #endif |
| 73 | |
| 74 | #ifndef AT_HWCAP2 |
| 75 | #define AT_HWCAP2 26 |
| 76 | #endif |
| 77 | |
| 78 | /* Some targets did not define these ptrace constants from the start, |
| 79 | so gdbserver defines them locally here. In the future, these may |
| 80 | be removed after they are added to asm/ptrace.h. */ |
| 81 | #if !(defined(PT_TEXT_ADDR) \ |
| 82 | || defined(PT_DATA_ADDR) \ |
| 83 | || defined(PT_TEXT_END_ADDR)) |
| 84 | #if defined(__mcoldfire__) |
| 85 | /* These are still undefined in 3.10 kernels. */ |
| 86 | #define PT_TEXT_ADDR 49*4 |
| 87 | #define PT_DATA_ADDR 50*4 |
| 88 | #define PT_TEXT_END_ADDR 51*4 |
| 89 | /* BFIN already defines these since at least 2.6.32 kernels. */ |
| 90 | #elif defined(BFIN) |
| 91 | #define PT_TEXT_ADDR 220 |
| 92 | #define PT_TEXT_END_ADDR 224 |
| 93 | #define PT_DATA_ADDR 228 |
| 94 | /* These are still undefined in 3.10 kernels. */ |
| 95 | #elif defined(__TMS320C6X__) |
| 96 | #define PT_TEXT_ADDR (0x10000*4) |
| 97 | #define PT_DATA_ADDR (0x10004*4) |
| 98 | #define PT_TEXT_END_ADDR (0x10008*4) |
| 99 | #endif |
| 100 | #endif |
| 101 | |
| 102 | #ifdef HAVE_LINUX_BTRACE |
| 103 | # include "nat/linux-btrace.h" |
| 104 | # include "gdbsupport/btrace-common.h" |
| 105 | #endif |
| 106 | |
| 107 | #ifndef HAVE_ELF32_AUXV_T |
| 108 | /* Copied from glibc's elf.h. */ |
| 109 | typedef struct |
| 110 | { |
| 111 | uint32_t a_type; /* Entry type */ |
| 112 | union |
| 113 | { |
| 114 | uint32_t a_val; /* Integer value */ |
| 115 | /* We use to have pointer elements added here. We cannot do that, |
| 116 | though, since it does not work when using 32-bit definitions |
| 117 | on 64-bit platforms and vice versa. */ |
| 118 | } a_un; |
| 119 | } Elf32_auxv_t; |
| 120 | #endif |
| 121 | |
| 122 | #ifndef HAVE_ELF64_AUXV_T |
| 123 | /* Copied from glibc's elf.h. */ |
| 124 | typedef struct |
| 125 | { |
| 126 | uint64_t a_type; /* Entry type */ |
| 127 | union |
| 128 | { |
| 129 | uint64_t a_val; /* Integer value */ |
| 130 | /* We use to have pointer elements added here. We cannot do that, |
| 131 | though, since it does not work when using 32-bit definitions |
| 132 | on 64-bit platforms and vice versa. */ |
| 133 | } a_un; |
| 134 | } Elf64_auxv_t; |
| 135 | #endif |
| 136 | |
| 137 | /* Does the current host support PTRACE_GETREGSET? */ |
| 138 | int have_ptrace_getregset = -1; |
| 139 | |
| 140 | /* LWP accessors. */ |
| 141 | |
| 142 | /* See nat/linux-nat.h. */ |
| 143 | |
| 144 | ptid_t |
| 145 | ptid_of_lwp (struct lwp_info *lwp) |
| 146 | { |
| 147 | return ptid_of (get_lwp_thread (lwp)); |
| 148 | } |
| 149 | |
| 150 | /* See nat/linux-nat.h. */ |
| 151 | |
| 152 | void |
| 153 | lwp_set_arch_private_info (struct lwp_info *lwp, |
| 154 | struct arch_lwp_info *info) |
| 155 | { |
| 156 | lwp->arch_private = info; |
| 157 | } |
| 158 | |
| 159 | /* See nat/linux-nat.h. */ |
| 160 | |
| 161 | struct arch_lwp_info * |
| 162 | lwp_arch_private_info (struct lwp_info *lwp) |
| 163 | { |
| 164 | return lwp->arch_private; |
| 165 | } |
| 166 | |
| 167 | /* See nat/linux-nat.h. */ |
| 168 | |
| 169 | int |
| 170 | lwp_is_stopped (struct lwp_info *lwp) |
| 171 | { |
| 172 | return lwp->stopped; |
| 173 | } |
| 174 | |
| 175 | /* See nat/linux-nat.h. */ |
| 176 | |
| 177 | enum target_stop_reason |
| 178 | lwp_stop_reason (struct lwp_info *lwp) |
| 179 | { |
| 180 | return lwp->stop_reason; |
| 181 | } |
| 182 | |
| 183 | /* See nat/linux-nat.h. */ |
| 184 | |
| 185 | int |
| 186 | lwp_is_stepping (struct lwp_info *lwp) |
| 187 | { |
| 188 | return lwp->stepping; |
| 189 | } |
| 190 | |
| 191 | /* A list of all unknown processes which receive stop signals. Some |
| 192 | other process will presumably claim each of these as forked |
| 193 | children momentarily. */ |
| 194 | |
| 195 | struct simple_pid_list |
| 196 | { |
| 197 | /* The process ID. */ |
| 198 | int pid; |
| 199 | |
| 200 | /* The status as reported by waitpid. */ |
| 201 | int status; |
| 202 | |
| 203 | /* Next in chain. */ |
| 204 | struct simple_pid_list *next; |
| 205 | }; |
| 206 | struct simple_pid_list *stopped_pids; |
| 207 | |
| 208 | /* Trivial list manipulation functions to keep track of a list of new |
| 209 | stopped processes. */ |
| 210 | |
| 211 | static void |
| 212 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
| 213 | { |
| 214 | struct simple_pid_list *new_pid = XNEW (struct simple_pid_list); |
| 215 | |
| 216 | new_pid->pid = pid; |
| 217 | new_pid->status = status; |
| 218 | new_pid->next = *listp; |
| 219 | *listp = new_pid; |
| 220 | } |
| 221 | |
| 222 | static int |
| 223 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
| 224 | { |
| 225 | struct simple_pid_list **p; |
| 226 | |
| 227 | for (p = listp; *p != NULL; p = &(*p)->next) |
| 228 | if ((*p)->pid == pid) |
| 229 | { |
| 230 | struct simple_pid_list *next = (*p)->next; |
| 231 | |
| 232 | *statusp = (*p)->status; |
| 233 | xfree (*p); |
| 234 | *p = next; |
| 235 | return 1; |
| 236 | } |
| 237 | return 0; |
| 238 | } |
| 239 | |
| 240 | enum stopping_threads_kind |
| 241 | { |
| 242 | /* Not stopping threads presently. */ |
| 243 | NOT_STOPPING_THREADS, |
| 244 | |
| 245 | /* Stopping threads. */ |
| 246 | STOPPING_THREADS, |
| 247 | |
| 248 | /* Stopping and suspending threads. */ |
| 249 | STOPPING_AND_SUSPENDING_THREADS |
| 250 | }; |
| 251 | |
| 252 | /* This is set while stop_all_lwps is in effect. */ |
| 253 | enum stopping_threads_kind stopping_threads = NOT_STOPPING_THREADS; |
| 254 | |
| 255 | /* FIXME make into a target method? */ |
| 256 | int using_threads = 1; |
| 257 | |
| 258 | /* True if we're presently stabilizing threads (moving them out of |
| 259 | jump pads). */ |
| 260 | static int stabilizing_threads; |
| 261 | |
| 262 | static void linux_resume_one_lwp (struct lwp_info *lwp, |
| 263 | int step, int signal, siginfo_t *info); |
| 264 | static void linux_resume (struct thread_resume *resume_info, size_t n); |
| 265 | static void stop_all_lwps (int suspend, struct lwp_info *except); |
| 266 | static void unstop_all_lwps (int unsuspend, struct lwp_info *except); |
| 267 | static void unsuspend_all_lwps (struct lwp_info *except); |
| 268 | static int linux_wait_for_event_filtered (ptid_t wait_ptid, ptid_t filter_ptid, |
| 269 | int *wstat, int options); |
| 270 | static int linux_wait_for_event (ptid_t ptid, int *wstat, int options); |
| 271 | static struct lwp_info *add_lwp (ptid_t ptid); |
| 272 | static void linux_mourn (struct process_info *process); |
| 273 | static int linux_stopped_by_watchpoint (void); |
| 274 | static void mark_lwp_dead (struct lwp_info *lwp, int wstat); |
| 275 | static int lwp_is_marked_dead (struct lwp_info *lwp); |
| 276 | static void proceed_all_lwps (void); |
| 277 | static int finish_step_over (struct lwp_info *lwp); |
| 278 | static int kill_lwp (unsigned long lwpid, int signo); |
| 279 | static void enqueue_pending_signal (struct lwp_info *lwp, int signal, siginfo_t *info); |
| 280 | static void complete_ongoing_step_over (void); |
| 281 | static int linux_low_ptrace_options (int attached); |
| 282 | static int check_ptrace_stopped_lwp_gone (struct lwp_info *lp); |
| 283 | static void proceed_one_lwp (thread_info *thread, lwp_info *except); |
| 284 | |
| 285 | /* When the event-loop is doing a step-over, this points at the thread |
| 286 | being stepped. */ |
| 287 | ptid_t step_over_bkpt; |
| 288 | |
| 289 | /* True if the low target can hardware single-step. */ |
| 290 | |
| 291 | static int |
| 292 | can_hardware_single_step (void) |
| 293 | { |
| 294 | if (the_low_target.supports_hardware_single_step != NULL) |
| 295 | return the_low_target.supports_hardware_single_step (); |
| 296 | else |
| 297 | return 0; |
| 298 | } |
| 299 | |
| 300 | /* True if the low target can software single-step. Such targets |
| 301 | implement the GET_NEXT_PCS callback. */ |
| 302 | |
| 303 | static int |
| 304 | can_software_single_step (void) |
| 305 | { |
| 306 | return (the_low_target.get_next_pcs != NULL); |
| 307 | } |
| 308 | |
| 309 | /* True if the low target supports memory breakpoints. If so, we'll |
| 310 | have a GET_PC implementation. */ |
| 311 | |
| 312 | static int |
| 313 | supports_breakpoints (void) |
| 314 | { |
| 315 | return (the_low_target.get_pc != NULL); |
| 316 | } |
| 317 | |
| 318 | /* Returns true if this target can support fast tracepoints. This |
| 319 | does not mean that the in-process agent has been loaded in the |
| 320 | inferior. */ |
| 321 | |
| 322 | static int |
| 323 | supports_fast_tracepoints (void) |
| 324 | { |
| 325 | return the_low_target.install_fast_tracepoint_jump_pad != NULL; |
| 326 | } |
| 327 | |
| 328 | /* True if LWP is stopped in its stepping range. */ |
| 329 | |
| 330 | static int |
| 331 | lwp_in_step_range (struct lwp_info *lwp) |
| 332 | { |
| 333 | CORE_ADDR pc = lwp->stop_pc; |
| 334 | |
| 335 | return (pc >= lwp->step_range_start && pc < lwp->step_range_end); |
| 336 | } |
| 337 | |
| 338 | struct pending_signals |
| 339 | { |
| 340 | int signal; |
| 341 | siginfo_t info; |
| 342 | struct pending_signals *prev; |
| 343 | }; |
| 344 | |
| 345 | /* The read/write ends of the pipe registered as waitable file in the |
| 346 | event loop. */ |
| 347 | static int linux_event_pipe[2] = { -1, -1 }; |
| 348 | |
| 349 | /* True if we're currently in async mode. */ |
| 350 | #define target_is_async_p() (linux_event_pipe[0] != -1) |
| 351 | |
| 352 | static void send_sigstop (struct lwp_info *lwp); |
| 353 | static void wait_for_sigstop (void); |
| 354 | |
| 355 | /* Return non-zero if HEADER is a 64-bit ELF file. */ |
| 356 | |
| 357 | static int |
| 358 | elf_64_header_p (const Elf64_Ehdr *header, unsigned int *machine) |
| 359 | { |
| 360 | if (header->e_ident[EI_MAG0] == ELFMAG0 |
| 361 | && header->e_ident[EI_MAG1] == ELFMAG1 |
| 362 | && header->e_ident[EI_MAG2] == ELFMAG2 |
| 363 | && header->e_ident[EI_MAG3] == ELFMAG3) |
| 364 | { |
| 365 | *machine = header->e_machine; |
| 366 | return header->e_ident[EI_CLASS] == ELFCLASS64; |
| 367 | |
| 368 | } |
| 369 | *machine = EM_NONE; |
| 370 | return -1; |
| 371 | } |
| 372 | |
| 373 | /* Return non-zero if FILE is a 64-bit ELF file, |
| 374 | zero if the file is not a 64-bit ELF file, |
| 375 | and -1 if the file is not accessible or doesn't exist. */ |
| 376 | |
| 377 | static int |
| 378 | elf_64_file_p (const char *file, unsigned int *machine) |
| 379 | { |
| 380 | Elf64_Ehdr header; |
| 381 | int fd; |
| 382 | |
| 383 | fd = open (file, O_RDONLY); |
| 384 | if (fd < 0) |
| 385 | return -1; |
| 386 | |
| 387 | if (read (fd, &header, sizeof (header)) != sizeof (header)) |
| 388 | { |
| 389 | close (fd); |
| 390 | return 0; |
| 391 | } |
| 392 | close (fd); |
| 393 | |
| 394 | return elf_64_header_p (&header, machine); |
| 395 | } |
| 396 | |
| 397 | /* Accepts an integer PID; Returns true if the executable PID is |
| 398 | running is a 64-bit ELF file.. */ |
| 399 | |
| 400 | int |
| 401 | linux_pid_exe_is_elf_64_file (int pid, unsigned int *machine) |
| 402 | { |
| 403 | char file[PATH_MAX]; |
| 404 | |
| 405 | sprintf (file, "/proc/%d/exe", pid); |
| 406 | return elf_64_file_p (file, machine); |
| 407 | } |
| 408 | |
| 409 | static void |
| 410 | delete_lwp (struct lwp_info *lwp) |
| 411 | { |
| 412 | struct thread_info *thr = get_lwp_thread (lwp); |
| 413 | |
| 414 | if (debug_threads) |
| 415 | debug_printf ("deleting %ld\n", lwpid_of (thr)); |
| 416 | |
| 417 | remove_thread (thr); |
| 418 | |
| 419 | if (the_low_target.delete_thread != NULL) |
| 420 | the_low_target.delete_thread (lwp->arch_private); |
| 421 | else |
| 422 | gdb_assert (lwp->arch_private == NULL); |
| 423 | |
| 424 | free (lwp); |
| 425 | } |
| 426 | |
| 427 | /* Add a process to the common process list, and set its private |
| 428 | data. */ |
| 429 | |
| 430 | static struct process_info * |
| 431 | linux_add_process (int pid, int attached) |
| 432 | { |
| 433 | struct process_info *proc; |
| 434 | |
| 435 | proc = add_process (pid, attached); |
| 436 | proc->priv = XCNEW (struct process_info_private); |
| 437 | |
| 438 | if (the_low_target.new_process != NULL) |
| 439 | proc->priv->arch_private = the_low_target.new_process (); |
| 440 | |
| 441 | return proc; |
| 442 | } |
| 443 | |
| 444 | static CORE_ADDR get_pc (struct lwp_info *lwp); |
| 445 | |
| 446 | /* Call the target arch_setup function on the current thread. */ |
| 447 | |
| 448 | static void |
| 449 | linux_arch_setup (void) |
| 450 | { |
| 451 | the_low_target.arch_setup (); |
| 452 | } |
| 453 | |
| 454 | /* Call the target arch_setup function on THREAD. */ |
| 455 | |
| 456 | static void |
| 457 | linux_arch_setup_thread (struct thread_info *thread) |
| 458 | { |
| 459 | struct thread_info *saved_thread; |
| 460 | |
| 461 | saved_thread = current_thread; |
| 462 | current_thread = thread; |
| 463 | |
| 464 | linux_arch_setup (); |
| 465 | |
| 466 | current_thread = saved_thread; |
| 467 | } |
| 468 | |
| 469 | /* Handle a GNU/Linux extended wait response. If we see a clone, |
| 470 | fork, or vfork event, we need to add the new LWP to our list |
| 471 | (and return 0 so as not to report the trap to higher layers). |
| 472 | If we see an exec event, we will modify ORIG_EVENT_LWP to point |
| 473 | to a new LWP representing the new program. */ |
| 474 | |
| 475 | static int |
| 476 | handle_extended_wait (struct lwp_info **orig_event_lwp, int wstat) |
| 477 | { |
| 478 | client_state &cs = get_client_state (); |
| 479 | struct lwp_info *event_lwp = *orig_event_lwp; |
| 480 | int event = linux_ptrace_get_extended_event (wstat); |
| 481 | struct thread_info *event_thr = get_lwp_thread (event_lwp); |
| 482 | struct lwp_info *new_lwp; |
| 483 | |
| 484 | gdb_assert (event_lwp->waitstatus.kind == TARGET_WAITKIND_IGNORE); |
| 485 | |
| 486 | /* All extended events we currently use are mid-syscall. Only |
| 487 | PTRACE_EVENT_STOP is delivered more like a signal-stop, but |
| 488 | you have to be using PTRACE_SEIZE to get that. */ |
| 489 | event_lwp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY; |
| 490 | |
| 491 | if ((event == PTRACE_EVENT_FORK) || (event == PTRACE_EVENT_VFORK) |
| 492 | || (event == PTRACE_EVENT_CLONE)) |
| 493 | { |
| 494 | ptid_t ptid; |
| 495 | unsigned long new_pid; |
| 496 | int ret, status; |
| 497 | |
| 498 | /* Get the pid of the new lwp. */ |
| 499 | ptrace (PTRACE_GETEVENTMSG, lwpid_of (event_thr), (PTRACE_TYPE_ARG3) 0, |
| 500 | &new_pid); |
| 501 | |
| 502 | /* If we haven't already seen the new PID stop, wait for it now. */ |
| 503 | if (!pull_pid_from_list (&stopped_pids, new_pid, &status)) |
| 504 | { |
| 505 | /* The new child has a pending SIGSTOP. We can't affect it until it |
| 506 | hits the SIGSTOP, but we're already attached. */ |
| 507 | |
| 508 | ret = my_waitpid (new_pid, &status, __WALL); |
| 509 | |
| 510 | if (ret == -1) |
| 511 | perror_with_name ("waiting for new child"); |
| 512 | else if (ret != new_pid) |
| 513 | warning ("wait returned unexpected PID %d", ret); |
| 514 | else if (!WIFSTOPPED (status)) |
| 515 | warning ("wait returned unexpected status 0x%x", status); |
| 516 | } |
| 517 | |
| 518 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) |
| 519 | { |
| 520 | struct process_info *parent_proc; |
| 521 | struct process_info *child_proc; |
| 522 | struct lwp_info *child_lwp; |
| 523 | struct thread_info *child_thr; |
| 524 | struct target_desc *tdesc; |
| 525 | |
| 526 | ptid = ptid_t (new_pid, new_pid, 0); |
| 527 | |
| 528 | if (debug_threads) |
| 529 | { |
| 530 | debug_printf ("HEW: Got fork event from LWP %ld, " |
| 531 | "new child is %d\n", |
| 532 | ptid_of (event_thr).lwp (), |
| 533 | ptid.pid ()); |
| 534 | } |
| 535 | |
| 536 | /* Add the new process to the tables and clone the breakpoint |
| 537 | lists of the parent. We need to do this even if the new process |
| 538 | will be detached, since we will need the process object and the |
| 539 | breakpoints to remove any breakpoints from memory when we |
| 540 | detach, and the client side will access registers. */ |
| 541 | child_proc = linux_add_process (new_pid, 0); |
| 542 | gdb_assert (child_proc != NULL); |
| 543 | child_lwp = add_lwp (ptid); |
| 544 | gdb_assert (child_lwp != NULL); |
| 545 | child_lwp->stopped = 1; |
| 546 | child_lwp->must_set_ptrace_flags = 1; |
| 547 | child_lwp->status_pending_p = 0; |
| 548 | child_thr = get_lwp_thread (child_lwp); |
| 549 | child_thr->last_resume_kind = resume_stop; |
| 550 | child_thr->last_status.kind = TARGET_WAITKIND_STOPPED; |
| 551 | |
| 552 | /* If we're suspending all threads, leave this one suspended |
| 553 | too. If the fork/clone parent is stepping over a breakpoint, |
| 554 | all other threads have been suspended already. Leave the |
| 555 | child suspended too. */ |
| 556 | if (stopping_threads == STOPPING_AND_SUSPENDING_THREADS |
| 557 | || event_lwp->bp_reinsert != 0) |
| 558 | { |
| 559 | if (debug_threads) |
| 560 | debug_printf ("HEW: leaving child suspended\n"); |
| 561 | child_lwp->suspended = 1; |
| 562 | } |
| 563 | |
| 564 | parent_proc = get_thread_process (event_thr); |
| 565 | child_proc->attached = parent_proc->attached; |
| 566 | |
| 567 | if (event_lwp->bp_reinsert != 0 |
| 568 | && can_software_single_step () |
| 569 | && event == PTRACE_EVENT_VFORK) |
| 570 | { |
| 571 | /* If we leave single-step breakpoints there, child will |
| 572 | hit it, so uninsert single-step breakpoints from parent |
| 573 | (and child). Once vfork child is done, reinsert |
| 574 | them back to parent. */ |
| 575 | uninsert_single_step_breakpoints (event_thr); |
| 576 | } |
| 577 | |
| 578 | clone_all_breakpoints (child_thr, event_thr); |
| 579 | |
| 580 | tdesc = allocate_target_description (); |
| 581 | copy_target_description (tdesc, parent_proc->tdesc); |
| 582 | child_proc->tdesc = tdesc; |
| 583 | |
| 584 | /* Clone arch-specific process data. */ |
| 585 | if (the_low_target.new_fork != NULL) |
| 586 | the_low_target.new_fork (parent_proc, child_proc); |
| 587 | |
| 588 | /* Save fork info in the parent thread. */ |
| 589 | if (event == PTRACE_EVENT_FORK) |
| 590 | event_lwp->waitstatus.kind = TARGET_WAITKIND_FORKED; |
| 591 | else if (event == PTRACE_EVENT_VFORK) |
| 592 | event_lwp->waitstatus.kind = TARGET_WAITKIND_VFORKED; |
| 593 | |
| 594 | event_lwp->waitstatus.value.related_pid = ptid; |
| 595 | |
| 596 | /* The status_pending field contains bits denoting the |
| 597 | extended event, so when the pending event is handled, |
| 598 | the handler will look at lwp->waitstatus. */ |
| 599 | event_lwp->status_pending_p = 1; |
| 600 | event_lwp->status_pending = wstat; |
| 601 | |
| 602 | /* Link the threads until the parent event is passed on to |
| 603 | higher layers. */ |
| 604 | event_lwp->fork_relative = child_lwp; |
| 605 | child_lwp->fork_relative = event_lwp; |
| 606 | |
| 607 | /* If the parent thread is doing step-over with single-step |
| 608 | breakpoints, the list of single-step breakpoints are cloned |
| 609 | from the parent's. Remove them from the child process. |
| 610 | In case of vfork, we'll reinsert them back once vforked |
| 611 | child is done. */ |
| 612 | if (event_lwp->bp_reinsert != 0 |
| 613 | && can_software_single_step ()) |
| 614 | { |
| 615 | /* The child process is forked and stopped, so it is safe |
| 616 | to access its memory without stopping all other threads |
| 617 | from other processes. */ |
| 618 | delete_single_step_breakpoints (child_thr); |
| 619 | |
| 620 | gdb_assert (has_single_step_breakpoints (event_thr)); |
| 621 | gdb_assert (!has_single_step_breakpoints (child_thr)); |
| 622 | } |
| 623 | |
| 624 | /* Report the event. */ |
| 625 | return 0; |
| 626 | } |
| 627 | |
| 628 | if (debug_threads) |
| 629 | debug_printf ("HEW: Got clone event " |
| 630 | "from LWP %ld, new child is LWP %ld\n", |
| 631 | lwpid_of (event_thr), new_pid); |
| 632 | |
| 633 | ptid = ptid_t (pid_of (event_thr), new_pid, 0); |
| 634 | new_lwp = add_lwp (ptid); |
| 635 | |
| 636 | /* Either we're going to immediately resume the new thread |
| 637 | or leave it stopped. linux_resume_one_lwp is a nop if it |
| 638 | thinks the thread is currently running, so set this first |
| 639 | before calling linux_resume_one_lwp. */ |
| 640 | new_lwp->stopped = 1; |
| 641 | |
| 642 | /* If we're suspending all threads, leave this one suspended |
| 643 | too. If the fork/clone parent is stepping over a breakpoint, |
| 644 | all other threads have been suspended already. Leave the |
| 645 | child suspended too. */ |
| 646 | if (stopping_threads == STOPPING_AND_SUSPENDING_THREADS |
| 647 | || event_lwp->bp_reinsert != 0) |
| 648 | new_lwp->suspended = 1; |
| 649 | |
| 650 | /* Normally we will get the pending SIGSTOP. But in some cases |
| 651 | we might get another signal delivered to the group first. |
| 652 | If we do get another signal, be sure not to lose it. */ |
| 653 | if (WSTOPSIG (status) != SIGSTOP) |
| 654 | { |
| 655 | new_lwp->stop_expected = 1; |
| 656 | new_lwp->status_pending_p = 1; |
| 657 | new_lwp->status_pending = status; |
| 658 | } |
| 659 | else if (cs.report_thread_events) |
| 660 | { |
| 661 | new_lwp->waitstatus.kind = TARGET_WAITKIND_THREAD_CREATED; |
| 662 | new_lwp->status_pending_p = 1; |
| 663 | new_lwp->status_pending = status; |
| 664 | } |
| 665 | |
| 666 | #ifdef USE_THREAD_DB |
| 667 | thread_db_notice_clone (event_thr, ptid); |
| 668 | #endif |
| 669 | |
| 670 | /* Don't report the event. */ |
| 671 | return 1; |
| 672 | } |
| 673 | else if (event == PTRACE_EVENT_VFORK_DONE) |
| 674 | { |
| 675 | event_lwp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE; |
| 676 | |
| 677 | if (event_lwp->bp_reinsert != 0 && can_software_single_step ()) |
| 678 | { |
| 679 | reinsert_single_step_breakpoints (event_thr); |
| 680 | |
| 681 | gdb_assert (has_single_step_breakpoints (event_thr)); |
| 682 | } |
| 683 | |
| 684 | /* Report the event. */ |
| 685 | return 0; |
| 686 | } |
| 687 | else if (event == PTRACE_EVENT_EXEC && cs.report_exec_events) |
| 688 | { |
| 689 | struct process_info *proc; |
| 690 | std::vector<int> syscalls_to_catch; |
| 691 | ptid_t event_ptid; |
| 692 | pid_t event_pid; |
| 693 | |
| 694 | if (debug_threads) |
| 695 | { |
| 696 | debug_printf ("HEW: Got exec event from LWP %ld\n", |
| 697 | lwpid_of (event_thr)); |
| 698 | } |
| 699 | |
| 700 | /* Get the event ptid. */ |
| 701 | event_ptid = ptid_of (event_thr); |
| 702 | event_pid = event_ptid.pid (); |
| 703 | |
| 704 | /* Save the syscall list from the execing process. */ |
| 705 | proc = get_thread_process (event_thr); |
| 706 | syscalls_to_catch = std::move (proc->syscalls_to_catch); |
| 707 | |
| 708 | /* Delete the execing process and all its threads. */ |
| 709 | linux_mourn (proc); |
| 710 | current_thread = NULL; |
| 711 | |
| 712 | /* Create a new process/lwp/thread. */ |
| 713 | proc = linux_add_process (event_pid, 0); |
| 714 | event_lwp = add_lwp (event_ptid); |
| 715 | event_thr = get_lwp_thread (event_lwp); |
| 716 | gdb_assert (current_thread == event_thr); |
| 717 | linux_arch_setup_thread (event_thr); |
| 718 | |
| 719 | /* Set the event status. */ |
| 720 | event_lwp->waitstatus.kind = TARGET_WAITKIND_EXECD; |
| 721 | event_lwp->waitstatus.value.execd_pathname |
| 722 | = xstrdup (linux_proc_pid_to_exec_file (lwpid_of (event_thr))); |
| 723 | |
| 724 | /* Mark the exec status as pending. */ |
| 725 | event_lwp->stopped = 1; |
| 726 | event_lwp->status_pending_p = 1; |
| 727 | event_lwp->status_pending = wstat; |
| 728 | event_thr->last_resume_kind = resume_continue; |
| 729 | event_thr->last_status.kind = TARGET_WAITKIND_IGNORE; |
| 730 | |
| 731 | /* Update syscall state in the new lwp, effectively mid-syscall too. */ |
| 732 | event_lwp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY; |
| 733 | |
| 734 | /* Restore the list to catch. Don't rely on the client, which is free |
| 735 | to avoid sending a new list when the architecture doesn't change. |
| 736 | Also, for ANY_SYSCALL, the architecture doesn't really matter. */ |
| 737 | proc->syscalls_to_catch = std::move (syscalls_to_catch); |
| 738 | |
| 739 | /* Report the event. */ |
| 740 | *orig_event_lwp = event_lwp; |
| 741 | return 0; |
| 742 | } |
| 743 | |
| 744 | internal_error (__FILE__, __LINE__, _("unknown ptrace event %d"), event); |
| 745 | } |
| 746 | |
| 747 | /* Return the PC as read from the regcache of LWP, without any |
| 748 | adjustment. */ |
| 749 | |
| 750 | static CORE_ADDR |
| 751 | get_pc (struct lwp_info *lwp) |
| 752 | { |
| 753 | struct thread_info *saved_thread; |
| 754 | struct regcache *regcache; |
| 755 | CORE_ADDR pc; |
| 756 | |
| 757 | if (the_low_target.get_pc == NULL) |
| 758 | return 0; |
| 759 | |
| 760 | saved_thread = current_thread; |
| 761 | current_thread = get_lwp_thread (lwp); |
| 762 | |
| 763 | regcache = get_thread_regcache (current_thread, 1); |
| 764 | pc = (*the_low_target.get_pc) (regcache); |
| 765 | |
| 766 | if (debug_threads) |
| 767 | debug_printf ("pc is 0x%lx\n", (long) pc); |
| 768 | |
| 769 | current_thread = saved_thread; |
| 770 | return pc; |
| 771 | } |
| 772 | |
| 773 | /* This function should only be called if LWP got a SYSCALL_SIGTRAP. |
| 774 | Fill *SYSNO with the syscall nr trapped. */ |
| 775 | |
| 776 | static void |
| 777 | get_syscall_trapinfo (struct lwp_info *lwp, int *sysno) |
| 778 | { |
| 779 | struct thread_info *saved_thread; |
| 780 | struct regcache *regcache; |
| 781 | |
| 782 | if (the_low_target.get_syscall_trapinfo == NULL) |
| 783 | { |
| 784 | /* If we cannot get the syscall trapinfo, report an unknown |
| 785 | system call number. */ |
| 786 | *sysno = UNKNOWN_SYSCALL; |
| 787 | return; |
| 788 | } |
| 789 | |
| 790 | saved_thread = current_thread; |
| 791 | current_thread = get_lwp_thread (lwp); |
| 792 | |
| 793 | regcache = get_thread_regcache (current_thread, 1); |
| 794 | (*the_low_target.get_syscall_trapinfo) (regcache, sysno); |
| 795 | |
| 796 | if (debug_threads) |
| 797 | debug_printf ("get_syscall_trapinfo sysno %d\n", *sysno); |
| 798 | |
| 799 | current_thread = saved_thread; |
| 800 | } |
| 801 | |
| 802 | static int check_stopped_by_watchpoint (struct lwp_info *child); |
| 803 | |
| 804 | /* Called when the LWP stopped for a signal/trap. If it stopped for a |
| 805 | trap check what caused it (breakpoint, watchpoint, trace, etc.), |
| 806 | and save the result in the LWP's stop_reason field. If it stopped |
| 807 | for a breakpoint, decrement the PC if necessary on the lwp's |
| 808 | architecture. Returns true if we now have the LWP's stop PC. */ |
| 809 | |
| 810 | static int |
| 811 | save_stop_reason (struct lwp_info *lwp) |
| 812 | { |
| 813 | CORE_ADDR pc; |
| 814 | CORE_ADDR sw_breakpoint_pc; |
| 815 | struct thread_info *saved_thread; |
| 816 | #if USE_SIGTRAP_SIGINFO |
| 817 | siginfo_t siginfo; |
| 818 | #endif |
| 819 | |
| 820 | if (the_low_target.get_pc == NULL) |
| 821 | return 0; |
| 822 | |
| 823 | pc = get_pc (lwp); |
| 824 | sw_breakpoint_pc = pc - the_low_target.decr_pc_after_break; |
| 825 | |
| 826 | /* breakpoint_at reads from the current thread. */ |
| 827 | saved_thread = current_thread; |
| 828 | current_thread = get_lwp_thread (lwp); |
| 829 | |
| 830 | #if USE_SIGTRAP_SIGINFO |
| 831 | if (ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread), |
| 832 | (PTRACE_TYPE_ARG3) 0, &siginfo) == 0) |
| 833 | { |
| 834 | if (siginfo.si_signo == SIGTRAP) |
| 835 | { |
| 836 | if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code) |
| 837 | && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) |
| 838 | { |
| 839 | /* The si_code is ambiguous on this arch -- check debug |
| 840 | registers. */ |
| 841 | if (!check_stopped_by_watchpoint (lwp)) |
| 842 | lwp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
| 843 | } |
| 844 | else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)) |
| 845 | { |
| 846 | /* If we determine the LWP stopped for a SW breakpoint, |
| 847 | trust it. Particularly don't check watchpoint |
| 848 | registers, because at least on s390, we'd find |
| 849 | stopped-by-watchpoint as long as there's a watchpoint |
| 850 | set. */ |
| 851 | lwp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
| 852 | } |
| 853 | else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) |
| 854 | { |
| 855 | /* This can indicate either a hardware breakpoint or |
| 856 | hardware watchpoint. Check debug registers. */ |
| 857 | if (!check_stopped_by_watchpoint (lwp)) |
| 858 | lwp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; |
| 859 | } |
| 860 | else if (siginfo.si_code == TRAP_TRACE) |
| 861 | { |
| 862 | /* We may have single stepped an instruction that |
| 863 | triggered a watchpoint. In that case, on some |
| 864 | architectures (such as x86), instead of TRAP_HWBKPT, |
| 865 | si_code indicates TRAP_TRACE, and we need to check |
| 866 | the debug registers separately. */ |
| 867 | if (!check_stopped_by_watchpoint (lwp)) |
| 868 | lwp->stop_reason = TARGET_STOPPED_BY_SINGLE_STEP; |
| 869 | } |
| 870 | } |
| 871 | } |
| 872 | #else |
| 873 | /* We may have just stepped a breakpoint instruction. E.g., in |
| 874 | non-stop mode, GDB first tells the thread A to step a range, and |
| 875 | then the user inserts a breakpoint inside the range. In that |
| 876 | case we need to report the breakpoint PC. */ |
| 877 | if ((!lwp->stepping || lwp->stop_pc == sw_breakpoint_pc) |
| 878 | && (*the_low_target.breakpoint_at) (sw_breakpoint_pc)) |
| 879 | lwp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
| 880 | |
| 881 | if (hardware_breakpoint_inserted_here (pc)) |
| 882 | lwp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; |
| 883 | |
| 884 | if (lwp->stop_reason == TARGET_STOPPED_BY_NO_REASON) |
| 885 | check_stopped_by_watchpoint (lwp); |
| 886 | #endif |
| 887 | |
| 888 | if (lwp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT) |
| 889 | { |
| 890 | if (debug_threads) |
| 891 | { |
| 892 | struct thread_info *thr = get_lwp_thread (lwp); |
| 893 | |
| 894 | debug_printf ("CSBB: %s stopped by software breakpoint\n", |
| 895 | target_pid_to_str (ptid_of (thr))); |
| 896 | } |
| 897 | |
| 898 | /* Back up the PC if necessary. */ |
| 899 | if (pc != sw_breakpoint_pc) |
| 900 | { |
| 901 | struct regcache *regcache |
| 902 | = get_thread_regcache (current_thread, 1); |
| 903 | (*the_low_target.set_pc) (regcache, sw_breakpoint_pc); |
| 904 | } |
| 905 | |
| 906 | /* Update this so we record the correct stop PC below. */ |
| 907 | pc = sw_breakpoint_pc; |
| 908 | } |
| 909 | else if (lwp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) |
| 910 | { |
| 911 | if (debug_threads) |
| 912 | { |
| 913 | struct thread_info *thr = get_lwp_thread (lwp); |
| 914 | |
| 915 | debug_printf ("CSBB: %s stopped by hardware breakpoint\n", |
| 916 | target_pid_to_str (ptid_of (thr))); |
| 917 | } |
| 918 | } |
| 919 | else if (lwp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT) |
| 920 | { |
| 921 | if (debug_threads) |
| 922 | { |
| 923 | struct thread_info *thr = get_lwp_thread (lwp); |
| 924 | |
| 925 | debug_printf ("CSBB: %s stopped by hardware watchpoint\n", |
| 926 | target_pid_to_str (ptid_of (thr))); |
| 927 | } |
| 928 | } |
| 929 | else if (lwp->stop_reason == TARGET_STOPPED_BY_SINGLE_STEP) |
| 930 | { |
| 931 | if (debug_threads) |
| 932 | { |
| 933 | struct thread_info *thr = get_lwp_thread (lwp); |
| 934 | |
| 935 | debug_printf ("CSBB: %s stopped by trace\n", |
| 936 | target_pid_to_str (ptid_of (thr))); |
| 937 | } |
| 938 | } |
| 939 | |
| 940 | lwp->stop_pc = pc; |
| 941 | current_thread = saved_thread; |
| 942 | return 1; |
| 943 | } |
| 944 | |
| 945 | static struct lwp_info * |
| 946 | add_lwp (ptid_t ptid) |
| 947 | { |
| 948 | struct lwp_info *lwp; |
| 949 | |
| 950 | lwp = XCNEW (struct lwp_info); |
| 951 | |
| 952 | lwp->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
| 953 | |
| 954 | lwp->thread = add_thread (ptid, lwp); |
| 955 | |
| 956 | if (the_low_target.new_thread != NULL) |
| 957 | the_low_target.new_thread (lwp); |
| 958 | |
| 959 | return lwp; |
| 960 | } |
| 961 | |
| 962 | /* Callback to be used when calling fork_inferior, responsible for |
| 963 | actually initiating the tracing of the inferior. */ |
| 964 | |
| 965 | static void |
| 966 | linux_ptrace_fun () |
| 967 | { |
| 968 | if (ptrace (PTRACE_TRACEME, 0, (PTRACE_TYPE_ARG3) 0, |
| 969 | (PTRACE_TYPE_ARG4) 0) < 0) |
| 970 | trace_start_error_with_name ("ptrace"); |
| 971 | |
| 972 | if (setpgid (0, 0) < 0) |
| 973 | trace_start_error_with_name ("setpgid"); |
| 974 | |
| 975 | /* If GDBserver is connected to gdb via stdio, redirect the inferior's |
| 976 | stdout to stderr so that inferior i/o doesn't corrupt the connection. |
| 977 | Also, redirect stdin to /dev/null. */ |
| 978 | if (remote_connection_is_stdio ()) |
| 979 | { |
| 980 | if (close (0) < 0) |
| 981 | trace_start_error_with_name ("close"); |
| 982 | if (open ("/dev/null", O_RDONLY) < 0) |
| 983 | trace_start_error_with_name ("open"); |
| 984 | if (dup2 (2, 1) < 0) |
| 985 | trace_start_error_with_name ("dup2"); |
| 986 | if (write (2, "stdin/stdout redirected\n", |
| 987 | sizeof ("stdin/stdout redirected\n") - 1) < 0) |
| 988 | { |
| 989 | /* Errors ignored. */; |
| 990 | } |
| 991 | } |
| 992 | } |
| 993 | |
| 994 | /* Start an inferior process and returns its pid. |
| 995 | PROGRAM is the name of the program to be started, and PROGRAM_ARGS |
| 996 | are its arguments. */ |
| 997 | |
| 998 | static int |
| 999 | linux_create_inferior (const char *program, |
| 1000 | const std::vector<char *> &program_args) |
| 1001 | { |
| 1002 | client_state &cs = get_client_state (); |
| 1003 | struct lwp_info *new_lwp; |
| 1004 | int pid; |
| 1005 | ptid_t ptid; |
| 1006 | |
| 1007 | { |
| 1008 | maybe_disable_address_space_randomization restore_personality |
| 1009 | (cs.disable_randomization); |
| 1010 | std::string str_program_args = stringify_argv (program_args); |
| 1011 | |
| 1012 | pid = fork_inferior (program, |
| 1013 | str_program_args.c_str (), |
| 1014 | get_environ ()->envp (), linux_ptrace_fun, |
| 1015 | NULL, NULL, NULL, NULL); |
| 1016 | } |
| 1017 | |
| 1018 | linux_add_process (pid, 0); |
| 1019 | |
| 1020 | ptid = ptid_t (pid, pid, 0); |
| 1021 | new_lwp = add_lwp (ptid); |
| 1022 | new_lwp->must_set_ptrace_flags = 1; |
| 1023 | |
| 1024 | post_fork_inferior (pid, program); |
| 1025 | |
| 1026 | return pid; |
| 1027 | } |
| 1028 | |
| 1029 | /* Implement the post_create_inferior target_ops method. */ |
| 1030 | |
| 1031 | static void |
| 1032 | linux_post_create_inferior (void) |
| 1033 | { |
| 1034 | struct lwp_info *lwp = get_thread_lwp (current_thread); |
| 1035 | |
| 1036 | linux_arch_setup (); |
| 1037 | |
| 1038 | if (lwp->must_set_ptrace_flags) |
| 1039 | { |
| 1040 | struct process_info *proc = current_process (); |
| 1041 | int options = linux_low_ptrace_options (proc->attached); |
| 1042 | |
| 1043 | linux_enable_event_reporting (lwpid_of (current_thread), options); |
| 1044 | lwp->must_set_ptrace_flags = 0; |
| 1045 | } |
| 1046 | } |
| 1047 | |
| 1048 | /* Attach to an inferior process. Returns 0 on success, ERRNO on |
| 1049 | error. */ |
| 1050 | |
| 1051 | int |
| 1052 | linux_attach_lwp (ptid_t ptid) |
| 1053 | { |
| 1054 | struct lwp_info *new_lwp; |
| 1055 | int lwpid = ptid.lwp (); |
| 1056 | |
| 1057 | if (ptrace (PTRACE_ATTACH, lwpid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0) |
| 1058 | != 0) |
| 1059 | return errno; |
| 1060 | |
| 1061 | new_lwp = add_lwp (ptid); |
| 1062 | |
| 1063 | /* We need to wait for SIGSTOP before being able to make the next |
| 1064 | ptrace call on this LWP. */ |
| 1065 | new_lwp->must_set_ptrace_flags = 1; |
| 1066 | |
| 1067 | if (linux_proc_pid_is_stopped (lwpid)) |
| 1068 | { |
| 1069 | if (debug_threads) |
| 1070 | debug_printf ("Attached to a stopped process\n"); |
| 1071 | |
| 1072 | /* The process is definitely stopped. It is in a job control |
| 1073 | stop, unless the kernel predates the TASK_STOPPED / |
| 1074 | TASK_TRACED distinction, in which case it might be in a |
| 1075 | ptrace stop. Make sure it is in a ptrace stop; from there we |
| 1076 | can kill it, signal it, et cetera. |
| 1077 | |
| 1078 | First make sure there is a pending SIGSTOP. Since we are |
| 1079 | already attached, the process can not transition from stopped |
| 1080 | to running without a PTRACE_CONT; so we know this signal will |
| 1081 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is |
| 1082 | probably already in the queue (unless this kernel is old |
| 1083 | enough to use TASK_STOPPED for ptrace stops); but since |
| 1084 | SIGSTOP is not an RT signal, it can only be queued once. */ |
| 1085 | kill_lwp (lwpid, SIGSTOP); |
| 1086 | |
| 1087 | /* Finally, resume the stopped process. This will deliver the |
| 1088 | SIGSTOP (or a higher priority signal, just like normal |
| 1089 | PTRACE_ATTACH), which we'll catch later on. */ |
| 1090 | ptrace (PTRACE_CONT, lwpid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0); |
| 1091 | } |
| 1092 | |
| 1093 | /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH |
| 1094 | brings it to a halt. |
| 1095 | |
| 1096 | There are several cases to consider here: |
| 1097 | |
| 1098 | 1) gdbserver has already attached to the process and is being notified |
| 1099 | of a new thread that is being created. |
| 1100 | In this case we should ignore that SIGSTOP and resume the |
| 1101 | process. This is handled below by setting stop_expected = 1, |
| 1102 | and the fact that add_thread sets last_resume_kind == |
| 1103 | resume_continue. |
| 1104 | |
| 1105 | 2) This is the first thread (the process thread), and we're attaching |
| 1106 | to it via attach_inferior. |
| 1107 | In this case we want the process thread to stop. |
| 1108 | This is handled by having linux_attach set last_resume_kind == |
| 1109 | resume_stop after we return. |
| 1110 | |
| 1111 | If the pid we are attaching to is also the tgid, we attach to and |
| 1112 | stop all the existing threads. Otherwise, we attach to pid and |
| 1113 | ignore any other threads in the same group as this pid. |
| 1114 | |
| 1115 | 3) GDB is connecting to gdbserver and is requesting an enumeration of all |
| 1116 | existing threads. |
| 1117 | In this case we want the thread to stop. |
| 1118 | FIXME: This case is currently not properly handled. |
| 1119 | We should wait for the SIGSTOP but don't. Things work apparently |
| 1120 | because enough time passes between when we ptrace (ATTACH) and when |
| 1121 | gdb makes the next ptrace call on the thread. |
| 1122 | |
| 1123 | On the other hand, if we are currently trying to stop all threads, we |
| 1124 | should treat the new thread as if we had sent it a SIGSTOP. This works |
| 1125 | because we are guaranteed that the add_lwp call above added us to the |
| 1126 | end of the list, and so the new thread has not yet reached |
| 1127 | wait_for_sigstop (but will). */ |
| 1128 | new_lwp->stop_expected = 1; |
| 1129 | |
| 1130 | return 0; |
| 1131 | } |
| 1132 | |
| 1133 | /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not |
| 1134 | already attached. Returns true if a new LWP is found, false |
| 1135 | otherwise. */ |
| 1136 | |
| 1137 | static int |
| 1138 | attach_proc_task_lwp_callback (ptid_t ptid) |
| 1139 | { |
| 1140 | /* Is this a new thread? */ |
| 1141 | if (find_thread_ptid (ptid) == NULL) |
| 1142 | { |
| 1143 | int lwpid = ptid.lwp (); |
| 1144 | int err; |
| 1145 | |
| 1146 | if (debug_threads) |
| 1147 | debug_printf ("Found new lwp %d\n", lwpid); |
| 1148 | |
| 1149 | err = linux_attach_lwp (ptid); |
| 1150 | |
| 1151 | /* Be quiet if we simply raced with the thread exiting. EPERM |
| 1152 | is returned if the thread's task still exists, and is marked |
| 1153 | as exited or zombie, as well as other conditions, so in that |
| 1154 | case, confirm the status in /proc/PID/status. */ |
| 1155 | if (err == ESRCH |
| 1156 | || (err == EPERM && linux_proc_pid_is_gone (lwpid))) |
| 1157 | { |
| 1158 | if (debug_threads) |
| 1159 | { |
| 1160 | debug_printf ("Cannot attach to lwp %d: " |
| 1161 | "thread is gone (%d: %s)\n", |
| 1162 | lwpid, err, strerror (err)); |
| 1163 | } |
| 1164 | } |
| 1165 | else if (err != 0) |
| 1166 | { |
| 1167 | std::string reason |
| 1168 | = linux_ptrace_attach_fail_reason_string (ptid, err); |
| 1169 | |
| 1170 | warning (_("Cannot attach to lwp %d: %s"), lwpid, reason.c_str ()); |
| 1171 | } |
| 1172 | |
| 1173 | return 1; |
| 1174 | } |
| 1175 | return 0; |
| 1176 | } |
| 1177 | |
| 1178 | static void async_file_mark (void); |
| 1179 | |
| 1180 | /* Attach to PID. If PID is the tgid, attach to it and all |
| 1181 | of its threads. */ |
| 1182 | |
| 1183 | static int |
| 1184 | linux_attach (unsigned long pid) |
| 1185 | { |
| 1186 | struct process_info *proc; |
| 1187 | struct thread_info *initial_thread; |
| 1188 | ptid_t ptid = ptid_t (pid, pid, 0); |
| 1189 | int err; |
| 1190 | |
| 1191 | proc = linux_add_process (pid, 1); |
| 1192 | |
| 1193 | /* Attach to PID. We will check for other threads |
| 1194 | soon. */ |
| 1195 | err = linux_attach_lwp (ptid); |
| 1196 | if (err != 0) |
| 1197 | { |
| 1198 | remove_process (proc); |
| 1199 | |
| 1200 | std::string reason = linux_ptrace_attach_fail_reason_string (ptid, err); |
| 1201 | error ("Cannot attach to process %ld: %s", pid, reason.c_str ()); |
| 1202 | } |
| 1203 | |
| 1204 | /* Don't ignore the initial SIGSTOP if we just attached to this |
| 1205 | process. It will be collected by wait shortly. */ |
| 1206 | initial_thread = find_thread_ptid (ptid_t (pid, pid, 0)); |
| 1207 | initial_thread->last_resume_kind = resume_stop; |
| 1208 | |
| 1209 | /* We must attach to every LWP. If /proc is mounted, use that to |
| 1210 | find them now. On the one hand, the inferior may be using raw |
| 1211 | clone instead of using pthreads. On the other hand, even if it |
| 1212 | is using pthreads, GDB may not be connected yet (thread_db needs |
| 1213 | to do symbol lookups, through qSymbol). Also, thread_db walks |
| 1214 | structures in the inferior's address space to find the list of |
| 1215 | threads/LWPs, and those structures may well be corrupted. Note |
| 1216 | that once thread_db is loaded, we'll still use it to list threads |
| 1217 | and associate pthread info with each LWP. */ |
| 1218 | linux_proc_attach_tgid_threads (pid, attach_proc_task_lwp_callback); |
| 1219 | |
| 1220 | /* GDB will shortly read the xml target description for this |
| 1221 | process, to figure out the process' architecture. But the target |
| 1222 | description is only filled in when the first process/thread in |
| 1223 | the thread group reports its initial PTRACE_ATTACH SIGSTOP. Do |
| 1224 | that now, otherwise, if GDB is fast enough, it could read the |
| 1225 | target description _before_ that initial stop. */ |
| 1226 | if (non_stop) |
| 1227 | { |
| 1228 | struct lwp_info *lwp; |
| 1229 | int wstat, lwpid; |
| 1230 | ptid_t pid_ptid = ptid_t (pid); |
| 1231 | |
| 1232 | lwpid = linux_wait_for_event_filtered (pid_ptid, pid_ptid, |
| 1233 | &wstat, __WALL); |
| 1234 | gdb_assert (lwpid > 0); |
| 1235 | |
| 1236 | lwp = find_lwp_pid (ptid_t (lwpid)); |
| 1237 | |
| 1238 | if (!WIFSTOPPED (wstat) || WSTOPSIG (wstat) != SIGSTOP) |
| 1239 | { |
| 1240 | lwp->status_pending_p = 1; |
| 1241 | lwp->status_pending = wstat; |
| 1242 | } |
| 1243 | |
| 1244 | initial_thread->last_resume_kind = resume_continue; |
| 1245 | |
| 1246 | async_file_mark (); |
| 1247 | |
| 1248 | gdb_assert (proc->tdesc != NULL); |
| 1249 | } |
| 1250 | |
| 1251 | return 0; |
| 1252 | } |
| 1253 | |
| 1254 | static int |
| 1255 | last_thread_of_process_p (int pid) |
| 1256 | { |
| 1257 | bool seen_one = false; |
| 1258 | |
| 1259 | thread_info *thread = find_thread (pid, [&] (thread_info *thr_arg) |
| 1260 | { |
| 1261 | if (!seen_one) |
| 1262 | { |
| 1263 | /* This is the first thread of this process we see. */ |
| 1264 | seen_one = true; |
| 1265 | return false; |
| 1266 | } |
| 1267 | else |
| 1268 | { |
| 1269 | /* This is the second thread of this process we see. */ |
| 1270 | return true; |
| 1271 | } |
| 1272 | }); |
| 1273 | |
| 1274 | return thread == NULL; |
| 1275 | } |
| 1276 | |
| 1277 | /* Kill LWP. */ |
| 1278 | |
| 1279 | static void |
| 1280 | linux_kill_one_lwp (struct lwp_info *lwp) |
| 1281 | { |
| 1282 | struct thread_info *thr = get_lwp_thread (lwp); |
| 1283 | int pid = lwpid_of (thr); |
| 1284 | |
| 1285 | /* PTRACE_KILL is unreliable. After stepping into a signal handler, |
| 1286 | there is no signal context, and ptrace(PTRACE_KILL) (or |
| 1287 | ptrace(PTRACE_CONT, SIGKILL), pretty much the same) acts like |
| 1288 | ptrace(CONT, pid, 0,0) and just resumes the tracee. A better |
| 1289 | alternative is to kill with SIGKILL. We only need one SIGKILL |
| 1290 | per process, not one for each thread. But since we still support |
| 1291 | support debugging programs using raw clone without CLONE_THREAD, |
| 1292 | we send one for each thread. For years, we used PTRACE_KILL |
| 1293 | only, so we're being a bit paranoid about some old kernels where |
| 1294 | PTRACE_KILL might work better (dubious if there are any such, but |
| 1295 | that's why it's paranoia), so we try SIGKILL first, PTRACE_KILL |
| 1296 | second, and so we're fine everywhere. */ |
| 1297 | |
| 1298 | errno = 0; |
| 1299 | kill_lwp (pid, SIGKILL); |
| 1300 | if (debug_threads) |
| 1301 | { |
| 1302 | int save_errno = errno; |
| 1303 | |
| 1304 | debug_printf ("LKL: kill_lwp (SIGKILL) %s, 0, 0 (%s)\n", |
| 1305 | target_pid_to_str (ptid_of (thr)), |
| 1306 | save_errno ? strerror (save_errno) : "OK"); |
| 1307 | } |
| 1308 | |
| 1309 | errno = 0; |
| 1310 | ptrace (PTRACE_KILL, pid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0); |
| 1311 | if (debug_threads) |
| 1312 | { |
| 1313 | int save_errno = errno; |
| 1314 | |
| 1315 | debug_printf ("LKL: PTRACE_KILL %s, 0, 0 (%s)\n", |
| 1316 | target_pid_to_str (ptid_of (thr)), |
| 1317 | save_errno ? strerror (save_errno) : "OK"); |
| 1318 | } |
| 1319 | } |
| 1320 | |
| 1321 | /* Kill LWP and wait for it to die. */ |
| 1322 | |
| 1323 | static void |
| 1324 | kill_wait_lwp (struct lwp_info *lwp) |
| 1325 | { |
| 1326 | struct thread_info *thr = get_lwp_thread (lwp); |
| 1327 | int pid = ptid_of (thr).pid (); |
| 1328 | int lwpid = ptid_of (thr).lwp (); |
| 1329 | int wstat; |
| 1330 | int res; |
| 1331 | |
| 1332 | if (debug_threads) |
| 1333 | debug_printf ("kwl: killing lwp %d, for pid: %d\n", lwpid, pid); |
| 1334 | |
| 1335 | do |
| 1336 | { |
| 1337 | linux_kill_one_lwp (lwp); |
| 1338 | |
| 1339 | /* Make sure it died. Notes: |
| 1340 | |
| 1341 | - The loop is most likely unnecessary. |
| 1342 | |
| 1343 | - We don't use linux_wait_for_event as that could delete lwps |
| 1344 | while we're iterating over them. We're not interested in |
| 1345 | any pending status at this point, only in making sure all |
| 1346 | wait status on the kernel side are collected until the |
| 1347 | process is reaped. |
| 1348 | |
| 1349 | - We don't use __WALL here as the __WALL emulation relies on |
| 1350 | SIGCHLD, and killing a stopped process doesn't generate |
| 1351 | one, nor an exit status. |
| 1352 | */ |
| 1353 | res = my_waitpid (lwpid, &wstat, 0); |
| 1354 | if (res == -1 && errno == ECHILD) |
| 1355 | res = my_waitpid (lwpid, &wstat, __WCLONE); |
| 1356 | } while (res > 0 && WIFSTOPPED (wstat)); |
| 1357 | |
| 1358 | /* Even if it was stopped, the child may have already disappeared. |
| 1359 | E.g., if it was killed by SIGKILL. */ |
| 1360 | if (res < 0 && errno != ECHILD) |
| 1361 | perror_with_name ("kill_wait_lwp"); |
| 1362 | } |
| 1363 | |
| 1364 | /* Callback for `for_each_thread'. Kills an lwp of a given process, |
| 1365 | except the leader. */ |
| 1366 | |
| 1367 | static void |
| 1368 | kill_one_lwp_callback (thread_info *thread, int pid) |
| 1369 | { |
| 1370 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 1371 | |
| 1372 | /* We avoid killing the first thread here, because of a Linux kernel (at |
| 1373 | least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before |
| 1374 | the children get a chance to be reaped, it will remain a zombie |
| 1375 | forever. */ |
| 1376 | |
| 1377 | if (lwpid_of (thread) == pid) |
| 1378 | { |
| 1379 | if (debug_threads) |
| 1380 | debug_printf ("lkop: is last of process %s\n", |
| 1381 | target_pid_to_str (thread->id)); |
| 1382 | return; |
| 1383 | } |
| 1384 | |
| 1385 | kill_wait_lwp (lwp); |
| 1386 | } |
| 1387 | |
| 1388 | static int |
| 1389 | linux_kill (process_info *process) |
| 1390 | { |
| 1391 | int pid = process->pid; |
| 1392 | |
| 1393 | /* If we're killing a running inferior, make sure it is stopped |
| 1394 | first, as PTRACE_KILL will not work otherwise. */ |
| 1395 | stop_all_lwps (0, NULL); |
| 1396 | |
| 1397 | for_each_thread (pid, [&] (thread_info *thread) |
| 1398 | { |
| 1399 | kill_one_lwp_callback (thread, pid); |
| 1400 | }); |
| 1401 | |
| 1402 | /* See the comment in linux_kill_one_lwp. We did not kill the first |
| 1403 | thread in the list, so do so now. */ |
| 1404 | lwp_info *lwp = find_lwp_pid (ptid_t (pid)); |
| 1405 | |
| 1406 | if (lwp == NULL) |
| 1407 | { |
| 1408 | if (debug_threads) |
| 1409 | debug_printf ("lk_1: cannot find lwp for pid: %d\n", |
| 1410 | pid); |
| 1411 | } |
| 1412 | else |
| 1413 | kill_wait_lwp (lwp); |
| 1414 | |
| 1415 | the_target->mourn (process); |
| 1416 | |
| 1417 | /* Since we presently can only stop all lwps of all processes, we |
| 1418 | need to unstop lwps of other processes. */ |
| 1419 | unstop_all_lwps (0, NULL); |
| 1420 | return 0; |
| 1421 | } |
| 1422 | |
| 1423 | /* Get pending signal of THREAD, for detaching purposes. This is the |
| 1424 | signal the thread last stopped for, which we need to deliver to the |
| 1425 | thread when detaching, otherwise, it'd be suppressed/lost. */ |
| 1426 | |
| 1427 | static int |
| 1428 | get_detach_signal (struct thread_info *thread) |
| 1429 | { |
| 1430 | client_state &cs = get_client_state (); |
| 1431 | enum gdb_signal signo = GDB_SIGNAL_0; |
| 1432 | int status; |
| 1433 | struct lwp_info *lp = get_thread_lwp (thread); |
| 1434 | |
| 1435 | if (lp->status_pending_p) |
| 1436 | status = lp->status_pending; |
| 1437 | else |
| 1438 | { |
| 1439 | /* If the thread had been suspended by gdbserver, and it stopped |
| 1440 | cleanly, then it'll have stopped with SIGSTOP. But we don't |
| 1441 | want to deliver that SIGSTOP. */ |
| 1442 | if (thread->last_status.kind != TARGET_WAITKIND_STOPPED |
| 1443 | || thread->last_status.value.sig == GDB_SIGNAL_0) |
| 1444 | return 0; |
| 1445 | |
| 1446 | /* Otherwise, we may need to deliver the signal we |
| 1447 | intercepted. */ |
| 1448 | status = lp->last_status; |
| 1449 | } |
| 1450 | |
| 1451 | if (!WIFSTOPPED (status)) |
| 1452 | { |
| 1453 | if (debug_threads) |
| 1454 | debug_printf ("GPS: lwp %s hasn't stopped: no pending signal\n", |
| 1455 | target_pid_to_str (ptid_of (thread))); |
| 1456 | return 0; |
| 1457 | } |
| 1458 | |
| 1459 | /* Extended wait statuses aren't real SIGTRAPs. */ |
| 1460 | if (WSTOPSIG (status) == SIGTRAP && linux_is_extended_waitstatus (status)) |
| 1461 | { |
| 1462 | if (debug_threads) |
| 1463 | debug_printf ("GPS: lwp %s had stopped with extended " |
| 1464 | "status: no pending signal\n", |
| 1465 | target_pid_to_str (ptid_of (thread))); |
| 1466 | return 0; |
| 1467 | } |
| 1468 | |
| 1469 | signo = gdb_signal_from_host (WSTOPSIG (status)); |
| 1470 | |
| 1471 | if (cs.program_signals_p && !cs.program_signals[signo]) |
| 1472 | { |
| 1473 | if (debug_threads) |
| 1474 | debug_printf ("GPS: lwp %s had signal %s, but it is in nopass state\n", |
| 1475 | target_pid_to_str (ptid_of (thread)), |
| 1476 | gdb_signal_to_string (signo)); |
| 1477 | return 0; |
| 1478 | } |
| 1479 | else if (!cs.program_signals_p |
| 1480 | /* If we have no way to know which signals GDB does not |
| 1481 | want to have passed to the program, assume |
| 1482 | SIGTRAP/SIGINT, which is GDB's default. */ |
| 1483 | && (signo == GDB_SIGNAL_TRAP || signo == GDB_SIGNAL_INT)) |
| 1484 | { |
| 1485 | if (debug_threads) |
| 1486 | debug_printf ("GPS: lwp %s had signal %s, " |
| 1487 | "but we don't know if we should pass it. " |
| 1488 | "Default to not.\n", |
| 1489 | target_pid_to_str (ptid_of (thread)), |
| 1490 | gdb_signal_to_string (signo)); |
| 1491 | return 0; |
| 1492 | } |
| 1493 | else |
| 1494 | { |
| 1495 | if (debug_threads) |
| 1496 | debug_printf ("GPS: lwp %s has pending signal %s: delivering it.\n", |
| 1497 | target_pid_to_str (ptid_of (thread)), |
| 1498 | gdb_signal_to_string (signo)); |
| 1499 | |
| 1500 | return WSTOPSIG (status); |
| 1501 | } |
| 1502 | } |
| 1503 | |
| 1504 | /* Detach from LWP. */ |
| 1505 | |
| 1506 | static void |
| 1507 | linux_detach_one_lwp (struct lwp_info *lwp) |
| 1508 | { |
| 1509 | struct thread_info *thread = get_lwp_thread (lwp); |
| 1510 | int sig; |
| 1511 | int lwpid; |
| 1512 | |
| 1513 | /* If there is a pending SIGSTOP, get rid of it. */ |
| 1514 | if (lwp->stop_expected) |
| 1515 | { |
| 1516 | if (debug_threads) |
| 1517 | debug_printf ("Sending SIGCONT to %s\n", |
| 1518 | target_pid_to_str (ptid_of (thread))); |
| 1519 | |
| 1520 | kill_lwp (lwpid_of (thread), SIGCONT); |
| 1521 | lwp->stop_expected = 0; |
| 1522 | } |
| 1523 | |
| 1524 | /* Pass on any pending signal for this thread. */ |
| 1525 | sig = get_detach_signal (thread); |
| 1526 | |
| 1527 | /* Preparing to resume may try to write registers, and fail if the |
| 1528 | lwp is zombie. If that happens, ignore the error. We'll handle |
| 1529 | it below, when detach fails with ESRCH. */ |
| 1530 | try |
| 1531 | { |
| 1532 | /* Flush any pending changes to the process's registers. */ |
| 1533 | regcache_invalidate_thread (thread); |
| 1534 | |
| 1535 | /* Finally, let it resume. */ |
| 1536 | if (the_low_target.prepare_to_resume != NULL) |
| 1537 | the_low_target.prepare_to_resume (lwp); |
| 1538 | } |
| 1539 | catch (const gdb_exception_error &ex) |
| 1540 | { |
| 1541 | if (!check_ptrace_stopped_lwp_gone (lwp)) |
| 1542 | throw; |
| 1543 | } |
| 1544 | |
| 1545 | lwpid = lwpid_of (thread); |
| 1546 | if (ptrace (PTRACE_DETACH, lwpid, (PTRACE_TYPE_ARG3) 0, |
| 1547 | (PTRACE_TYPE_ARG4) (long) sig) < 0) |
| 1548 | { |
| 1549 | int save_errno = errno; |
| 1550 | |
| 1551 | /* We know the thread exists, so ESRCH must mean the lwp is |
| 1552 | zombie. This can happen if one of the already-detached |
| 1553 | threads exits the whole thread group. In that case we're |
| 1554 | still attached, and must reap the lwp. */ |
| 1555 | if (save_errno == ESRCH) |
| 1556 | { |
| 1557 | int ret, status; |
| 1558 | |
| 1559 | ret = my_waitpid (lwpid, &status, __WALL); |
| 1560 | if (ret == -1) |
| 1561 | { |
| 1562 | warning (_("Couldn't reap LWP %d while detaching: %s"), |
| 1563 | lwpid, strerror (errno)); |
| 1564 | } |
| 1565 | else if (!WIFEXITED (status) && !WIFSIGNALED (status)) |
| 1566 | { |
| 1567 | warning (_("Reaping LWP %d while detaching " |
| 1568 | "returned unexpected status 0x%x"), |
| 1569 | lwpid, status); |
| 1570 | } |
| 1571 | } |
| 1572 | else |
| 1573 | { |
| 1574 | error (_("Can't detach %s: %s"), |
| 1575 | target_pid_to_str (ptid_of (thread)), |
| 1576 | strerror (save_errno)); |
| 1577 | } |
| 1578 | } |
| 1579 | else if (debug_threads) |
| 1580 | { |
| 1581 | debug_printf ("PTRACE_DETACH (%s, %s, 0) (OK)\n", |
| 1582 | target_pid_to_str (ptid_of (thread)), |
| 1583 | strsignal (sig)); |
| 1584 | } |
| 1585 | |
| 1586 | delete_lwp (lwp); |
| 1587 | } |
| 1588 | |
| 1589 | /* Callback for for_each_thread. Detaches from non-leader threads of a |
| 1590 | given process. */ |
| 1591 | |
| 1592 | static void |
| 1593 | linux_detach_lwp_callback (thread_info *thread) |
| 1594 | { |
| 1595 | /* We don't actually detach from the thread group leader just yet. |
| 1596 | If the thread group exits, we must reap the zombie clone lwps |
| 1597 | before we're able to reap the leader. */ |
| 1598 | if (thread->id.pid () == thread->id.lwp ()) |
| 1599 | return; |
| 1600 | |
| 1601 | lwp_info *lwp = get_thread_lwp (thread); |
| 1602 | linux_detach_one_lwp (lwp); |
| 1603 | } |
| 1604 | |
| 1605 | static int |
| 1606 | linux_detach (process_info *process) |
| 1607 | { |
| 1608 | struct lwp_info *main_lwp; |
| 1609 | |
| 1610 | /* As there's a step over already in progress, let it finish first, |
| 1611 | otherwise nesting a stabilize_threads operation on top gets real |
| 1612 | messy. */ |
| 1613 | complete_ongoing_step_over (); |
| 1614 | |
| 1615 | /* Stop all threads before detaching. First, ptrace requires that |
| 1616 | the thread is stopped to sucessfully detach. Second, thread_db |
| 1617 | may need to uninstall thread event breakpoints from memory, which |
| 1618 | only works with a stopped process anyway. */ |
| 1619 | stop_all_lwps (0, NULL); |
| 1620 | |
| 1621 | #ifdef USE_THREAD_DB |
| 1622 | thread_db_detach (process); |
| 1623 | #endif |
| 1624 | |
| 1625 | /* Stabilize threads (move out of jump pads). */ |
| 1626 | stabilize_threads (); |
| 1627 | |
| 1628 | /* Detach from the clone lwps first. If the thread group exits just |
| 1629 | while we're detaching, we must reap the clone lwps before we're |
| 1630 | able to reap the leader. */ |
| 1631 | for_each_thread (process->pid, linux_detach_lwp_callback); |
| 1632 | |
| 1633 | main_lwp = find_lwp_pid (ptid_t (process->pid)); |
| 1634 | linux_detach_one_lwp (main_lwp); |
| 1635 | |
| 1636 | the_target->mourn (process); |
| 1637 | |
| 1638 | /* Since we presently can only stop all lwps of all processes, we |
| 1639 | need to unstop lwps of other processes. */ |
| 1640 | unstop_all_lwps (0, NULL); |
| 1641 | return 0; |
| 1642 | } |
| 1643 | |
| 1644 | /* Remove all LWPs that belong to process PROC from the lwp list. */ |
| 1645 | |
| 1646 | static void |
| 1647 | linux_mourn (struct process_info *process) |
| 1648 | { |
| 1649 | struct process_info_private *priv; |
| 1650 | |
| 1651 | #ifdef USE_THREAD_DB |
| 1652 | thread_db_mourn (process); |
| 1653 | #endif |
| 1654 | |
| 1655 | for_each_thread (process->pid, [] (thread_info *thread) |
| 1656 | { |
| 1657 | delete_lwp (get_thread_lwp (thread)); |
| 1658 | }); |
| 1659 | |
| 1660 | /* Freeing all private data. */ |
| 1661 | priv = process->priv; |
| 1662 | if (the_low_target.delete_process != NULL) |
| 1663 | the_low_target.delete_process (priv->arch_private); |
| 1664 | else |
| 1665 | gdb_assert (priv->arch_private == NULL); |
| 1666 | free (priv); |
| 1667 | process->priv = NULL; |
| 1668 | |
| 1669 | remove_process (process); |
| 1670 | } |
| 1671 | |
| 1672 | static void |
| 1673 | linux_join (int pid) |
| 1674 | { |
| 1675 | int status, ret; |
| 1676 | |
| 1677 | do { |
| 1678 | ret = my_waitpid (pid, &status, 0); |
| 1679 | if (WIFEXITED (status) || WIFSIGNALED (status)) |
| 1680 | break; |
| 1681 | } while (ret != -1 || errno != ECHILD); |
| 1682 | } |
| 1683 | |
| 1684 | /* Return nonzero if the given thread is still alive. */ |
| 1685 | static int |
| 1686 | linux_thread_alive (ptid_t ptid) |
| 1687 | { |
| 1688 | struct lwp_info *lwp = find_lwp_pid (ptid); |
| 1689 | |
| 1690 | /* We assume we always know if a thread exits. If a whole process |
| 1691 | exited but we still haven't been able to report it to GDB, we'll |
| 1692 | hold on to the last lwp of the dead process. */ |
| 1693 | if (lwp != NULL) |
| 1694 | return !lwp_is_marked_dead (lwp); |
| 1695 | else |
| 1696 | return 0; |
| 1697 | } |
| 1698 | |
| 1699 | /* Return 1 if this lwp still has an interesting status pending. If |
| 1700 | not (e.g., it had stopped for a breakpoint that is gone), return |
| 1701 | false. */ |
| 1702 | |
| 1703 | static int |
| 1704 | thread_still_has_status_pending_p (struct thread_info *thread) |
| 1705 | { |
| 1706 | struct lwp_info *lp = get_thread_lwp (thread); |
| 1707 | |
| 1708 | if (!lp->status_pending_p) |
| 1709 | return 0; |
| 1710 | |
| 1711 | if (thread->last_resume_kind != resume_stop |
| 1712 | && (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
| 1713 | || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)) |
| 1714 | { |
| 1715 | struct thread_info *saved_thread; |
| 1716 | CORE_ADDR pc; |
| 1717 | int discard = 0; |
| 1718 | |
| 1719 | gdb_assert (lp->last_status != 0); |
| 1720 | |
| 1721 | pc = get_pc (lp); |
| 1722 | |
| 1723 | saved_thread = current_thread; |
| 1724 | current_thread = thread; |
| 1725 | |
| 1726 | if (pc != lp->stop_pc) |
| 1727 | { |
| 1728 | if (debug_threads) |
| 1729 | debug_printf ("PC of %ld changed\n", |
| 1730 | lwpid_of (thread)); |
| 1731 | discard = 1; |
| 1732 | } |
| 1733 | |
| 1734 | #if !USE_SIGTRAP_SIGINFO |
| 1735 | else if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
| 1736 | && !(*the_low_target.breakpoint_at) (pc)) |
| 1737 | { |
| 1738 | if (debug_threads) |
| 1739 | debug_printf ("previous SW breakpoint of %ld gone\n", |
| 1740 | lwpid_of (thread)); |
| 1741 | discard = 1; |
| 1742 | } |
| 1743 | else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT |
| 1744 | && !hardware_breakpoint_inserted_here (pc)) |
| 1745 | { |
| 1746 | if (debug_threads) |
| 1747 | debug_printf ("previous HW breakpoint of %ld gone\n", |
| 1748 | lwpid_of (thread)); |
| 1749 | discard = 1; |
| 1750 | } |
| 1751 | #endif |
| 1752 | |
| 1753 | current_thread = saved_thread; |
| 1754 | |
| 1755 | if (discard) |
| 1756 | { |
| 1757 | if (debug_threads) |
| 1758 | debug_printf ("discarding pending breakpoint status\n"); |
| 1759 | lp->status_pending_p = 0; |
| 1760 | return 0; |
| 1761 | } |
| 1762 | } |
| 1763 | |
| 1764 | return 1; |
| 1765 | } |
| 1766 | |
| 1767 | /* Returns true if LWP is resumed from the client's perspective. */ |
| 1768 | |
| 1769 | static int |
| 1770 | lwp_resumed (struct lwp_info *lwp) |
| 1771 | { |
| 1772 | struct thread_info *thread = get_lwp_thread (lwp); |
| 1773 | |
| 1774 | if (thread->last_resume_kind != resume_stop) |
| 1775 | return 1; |
| 1776 | |
| 1777 | /* Did gdb send us a `vCont;t', but we haven't reported the |
| 1778 | corresponding stop to gdb yet? If so, the thread is still |
| 1779 | resumed/running from gdb's perspective. */ |
| 1780 | if (thread->last_resume_kind == resume_stop |
| 1781 | && thread->last_status.kind == TARGET_WAITKIND_IGNORE) |
| 1782 | return 1; |
| 1783 | |
| 1784 | return 0; |
| 1785 | } |
| 1786 | |
| 1787 | /* Return true if this lwp has an interesting status pending. */ |
| 1788 | static bool |
| 1789 | status_pending_p_callback (thread_info *thread, ptid_t ptid) |
| 1790 | { |
| 1791 | struct lwp_info *lp = get_thread_lwp (thread); |
| 1792 | |
| 1793 | /* Check if we're only interested in events from a specific process |
| 1794 | or a specific LWP. */ |
| 1795 | if (!thread->id.matches (ptid)) |
| 1796 | return 0; |
| 1797 | |
| 1798 | if (!lwp_resumed (lp)) |
| 1799 | return 0; |
| 1800 | |
| 1801 | if (lp->status_pending_p |
| 1802 | && !thread_still_has_status_pending_p (thread)) |
| 1803 | { |
| 1804 | linux_resume_one_lwp (lp, lp->stepping, GDB_SIGNAL_0, NULL); |
| 1805 | return 0; |
| 1806 | } |
| 1807 | |
| 1808 | return lp->status_pending_p; |
| 1809 | } |
| 1810 | |
| 1811 | struct lwp_info * |
| 1812 | find_lwp_pid (ptid_t ptid) |
| 1813 | { |
| 1814 | thread_info *thread = find_thread ([&] (thread_info *thr_arg) |
| 1815 | { |
| 1816 | int lwp = ptid.lwp () != 0 ? ptid.lwp () : ptid.pid (); |
| 1817 | return thr_arg->id.lwp () == lwp; |
| 1818 | }); |
| 1819 | |
| 1820 | if (thread == NULL) |
| 1821 | return NULL; |
| 1822 | |
| 1823 | return get_thread_lwp (thread); |
| 1824 | } |
| 1825 | |
| 1826 | /* Return the number of known LWPs in the tgid given by PID. */ |
| 1827 | |
| 1828 | static int |
| 1829 | num_lwps (int pid) |
| 1830 | { |
| 1831 | int count = 0; |
| 1832 | |
| 1833 | for_each_thread (pid, [&] (thread_info *thread) |
| 1834 | { |
| 1835 | count++; |
| 1836 | }); |
| 1837 | |
| 1838 | return count; |
| 1839 | } |
| 1840 | |
| 1841 | /* See nat/linux-nat.h. */ |
| 1842 | |
| 1843 | struct lwp_info * |
| 1844 | iterate_over_lwps (ptid_t filter, |
| 1845 | gdb::function_view<iterate_over_lwps_ftype> callback) |
| 1846 | { |
| 1847 | thread_info *thread = find_thread (filter, [&] (thread_info *thr_arg) |
| 1848 | { |
| 1849 | lwp_info *lwp = get_thread_lwp (thr_arg); |
| 1850 | |
| 1851 | return callback (lwp); |
| 1852 | }); |
| 1853 | |
| 1854 | if (thread == NULL) |
| 1855 | return NULL; |
| 1856 | |
| 1857 | return get_thread_lwp (thread); |
| 1858 | } |
| 1859 | |
| 1860 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
| 1861 | their exits until all other threads in the group have exited. */ |
| 1862 | |
| 1863 | static void |
| 1864 | check_zombie_leaders (void) |
| 1865 | { |
| 1866 | for_each_process ([] (process_info *proc) { |
| 1867 | pid_t leader_pid = pid_of (proc); |
| 1868 | struct lwp_info *leader_lp; |
| 1869 | |
| 1870 | leader_lp = find_lwp_pid (ptid_t (leader_pid)); |
| 1871 | |
| 1872 | if (debug_threads) |
| 1873 | debug_printf ("leader_pid=%d, leader_lp!=NULL=%d, " |
| 1874 | "num_lwps=%d, zombie=%d\n", |
| 1875 | leader_pid, leader_lp!= NULL, num_lwps (leader_pid), |
| 1876 | linux_proc_pid_is_zombie (leader_pid)); |
| 1877 | |
| 1878 | if (leader_lp != NULL && !leader_lp->stopped |
| 1879 | /* Check if there are other threads in the group, as we may |
| 1880 | have raced with the inferior simply exiting. */ |
| 1881 | && !last_thread_of_process_p (leader_pid) |
| 1882 | && linux_proc_pid_is_zombie (leader_pid)) |
| 1883 | { |
| 1884 | /* A leader zombie can mean one of two things: |
| 1885 | |
| 1886 | - It exited, and there's an exit status pending |
| 1887 | available, or only the leader exited (not the whole |
| 1888 | program). In the latter case, we can't waitpid the |
| 1889 | leader's exit status until all other threads are gone. |
| 1890 | |
| 1891 | - There are 3 or more threads in the group, and a thread |
| 1892 | other than the leader exec'd. On an exec, the Linux |
| 1893 | kernel destroys all other threads (except the execing |
| 1894 | one) in the thread group, and resets the execing thread's |
| 1895 | tid to the tgid. No exit notification is sent for the |
| 1896 | execing thread -- from the ptracer's perspective, it |
| 1897 | appears as though the execing thread just vanishes. |
| 1898 | Until we reap all other threads except the leader and the |
| 1899 | execing thread, the leader will be zombie, and the |
| 1900 | execing thread will be in `D (disc sleep)'. As soon as |
| 1901 | all other threads are reaped, the execing thread changes |
| 1902 | it's tid to the tgid, and the previous (zombie) leader |
| 1903 | vanishes, giving place to the "new" leader. We could try |
| 1904 | distinguishing the exit and exec cases, by waiting once |
| 1905 | more, and seeing if something comes out, but it doesn't |
| 1906 | sound useful. The previous leader _does_ go away, and |
| 1907 | we'll re-add the new one once we see the exec event |
| 1908 | (which is just the same as what would happen if the |
| 1909 | previous leader did exit voluntarily before some other |
| 1910 | thread execs). */ |
| 1911 | |
| 1912 | if (debug_threads) |
| 1913 | debug_printf ("CZL: Thread group leader %d zombie " |
| 1914 | "(it exited, or another thread execd).\n", |
| 1915 | leader_pid); |
| 1916 | |
| 1917 | delete_lwp (leader_lp); |
| 1918 | } |
| 1919 | }); |
| 1920 | } |
| 1921 | |
| 1922 | /* Callback for `find_thread'. Returns the first LWP that is not |
| 1923 | stopped. */ |
| 1924 | |
| 1925 | static bool |
| 1926 | not_stopped_callback (thread_info *thread, ptid_t filter) |
| 1927 | { |
| 1928 | if (!thread->id.matches (filter)) |
| 1929 | return false; |
| 1930 | |
| 1931 | lwp_info *lwp = get_thread_lwp (thread); |
| 1932 | |
| 1933 | return !lwp->stopped; |
| 1934 | } |
| 1935 | |
| 1936 | /* Increment LWP's suspend count. */ |
| 1937 | |
| 1938 | static void |
| 1939 | lwp_suspended_inc (struct lwp_info *lwp) |
| 1940 | { |
| 1941 | lwp->suspended++; |
| 1942 | |
| 1943 | if (debug_threads && lwp->suspended > 4) |
| 1944 | { |
| 1945 | struct thread_info *thread = get_lwp_thread (lwp); |
| 1946 | |
| 1947 | debug_printf ("LWP %ld has a suspiciously high suspend count," |
| 1948 | " suspended=%d\n", lwpid_of (thread), lwp->suspended); |
| 1949 | } |
| 1950 | } |
| 1951 | |
| 1952 | /* Decrement LWP's suspend count. */ |
| 1953 | |
| 1954 | static void |
| 1955 | lwp_suspended_decr (struct lwp_info *lwp) |
| 1956 | { |
| 1957 | lwp->suspended--; |
| 1958 | |
| 1959 | if (lwp->suspended < 0) |
| 1960 | { |
| 1961 | struct thread_info *thread = get_lwp_thread (lwp); |
| 1962 | |
| 1963 | internal_error (__FILE__, __LINE__, |
| 1964 | "unsuspend LWP %ld, suspended=%d\n", lwpid_of (thread), |
| 1965 | lwp->suspended); |
| 1966 | } |
| 1967 | } |
| 1968 | |
| 1969 | /* This function should only be called if the LWP got a SIGTRAP. |
| 1970 | |
| 1971 | Handle any tracepoint steps or hits. Return true if a tracepoint |
| 1972 | event was handled, 0 otherwise. */ |
| 1973 | |
| 1974 | static int |
| 1975 | handle_tracepoints (struct lwp_info *lwp) |
| 1976 | { |
| 1977 | struct thread_info *tinfo = get_lwp_thread (lwp); |
| 1978 | int tpoint_related_event = 0; |
| 1979 | |
| 1980 | gdb_assert (lwp->suspended == 0); |
| 1981 | |
| 1982 | /* If this tracepoint hit causes a tracing stop, we'll immediately |
| 1983 | uninsert tracepoints. To do this, we temporarily pause all |
| 1984 | threads, unpatch away, and then unpause threads. We need to make |
| 1985 | sure the unpausing doesn't resume LWP too. */ |
| 1986 | lwp_suspended_inc (lwp); |
| 1987 | |
| 1988 | /* And we need to be sure that any all-threads-stopping doesn't try |
| 1989 | to move threads out of the jump pads, as it could deadlock the |
| 1990 | inferior (LWP could be in the jump pad, maybe even holding the |
| 1991 | lock.) */ |
| 1992 | |
| 1993 | /* Do any necessary step collect actions. */ |
| 1994 | tpoint_related_event |= tracepoint_finished_step (tinfo, lwp->stop_pc); |
| 1995 | |
| 1996 | tpoint_related_event |= handle_tracepoint_bkpts (tinfo, lwp->stop_pc); |
| 1997 | |
| 1998 | /* See if we just hit a tracepoint and do its main collect |
| 1999 | actions. */ |
| 2000 | tpoint_related_event |= tracepoint_was_hit (tinfo, lwp->stop_pc); |
| 2001 | |
| 2002 | lwp_suspended_decr (lwp); |
| 2003 | |
| 2004 | gdb_assert (lwp->suspended == 0); |
| 2005 | gdb_assert (!stabilizing_threads |
| 2006 | || (lwp->collecting_fast_tracepoint |
| 2007 | != fast_tpoint_collect_result::not_collecting)); |
| 2008 | |
| 2009 | if (tpoint_related_event) |
| 2010 | { |
| 2011 | if (debug_threads) |
| 2012 | debug_printf ("got a tracepoint event\n"); |
| 2013 | return 1; |
| 2014 | } |
| 2015 | |
| 2016 | return 0; |
| 2017 | } |
| 2018 | |
| 2019 | /* Convenience wrapper. Returns information about LWP's fast tracepoint |
| 2020 | collection status. */ |
| 2021 | |
| 2022 | static fast_tpoint_collect_result |
| 2023 | linux_fast_tracepoint_collecting (struct lwp_info *lwp, |
| 2024 | struct fast_tpoint_collect_status *status) |
| 2025 | { |
| 2026 | CORE_ADDR thread_area; |
| 2027 | struct thread_info *thread = get_lwp_thread (lwp); |
| 2028 | |
| 2029 | if (the_low_target.get_thread_area == NULL) |
| 2030 | return fast_tpoint_collect_result::not_collecting; |
| 2031 | |
| 2032 | /* Get the thread area address. This is used to recognize which |
| 2033 | thread is which when tracing with the in-process agent library. |
| 2034 | We don't read anything from the address, and treat it as opaque; |
| 2035 | it's the address itself that we assume is unique per-thread. */ |
| 2036 | if ((*the_low_target.get_thread_area) (lwpid_of (thread), &thread_area) == -1) |
| 2037 | return fast_tpoint_collect_result::not_collecting; |
| 2038 | |
| 2039 | return fast_tracepoint_collecting (thread_area, lwp->stop_pc, status); |
| 2040 | } |
| 2041 | |
| 2042 | /* The reason we resume in the caller, is because we want to be able |
| 2043 | to pass lwp->status_pending as WSTAT, and we need to clear |
| 2044 | status_pending_p before resuming, otherwise, linux_resume_one_lwp |
| 2045 | refuses to resume. */ |
| 2046 | |
| 2047 | static int |
| 2048 | maybe_move_out_of_jump_pad (struct lwp_info *lwp, int *wstat) |
| 2049 | { |
| 2050 | struct thread_info *saved_thread; |
| 2051 | |
| 2052 | saved_thread = current_thread; |
| 2053 | current_thread = get_lwp_thread (lwp); |
| 2054 | |
| 2055 | if ((wstat == NULL |
| 2056 | || (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) != SIGTRAP)) |
| 2057 | && supports_fast_tracepoints () |
| 2058 | && agent_loaded_p ()) |
| 2059 | { |
| 2060 | struct fast_tpoint_collect_status status; |
| 2061 | |
| 2062 | if (debug_threads) |
| 2063 | debug_printf ("Checking whether LWP %ld needs to move out of the " |
| 2064 | "jump pad.\n", |
| 2065 | lwpid_of (current_thread)); |
| 2066 | |
| 2067 | fast_tpoint_collect_result r |
| 2068 | = linux_fast_tracepoint_collecting (lwp, &status); |
| 2069 | |
| 2070 | if (wstat == NULL |
| 2071 | || (WSTOPSIG (*wstat) != SIGILL |
| 2072 | && WSTOPSIG (*wstat) != SIGFPE |
| 2073 | && WSTOPSIG (*wstat) != SIGSEGV |
| 2074 | && WSTOPSIG (*wstat) != SIGBUS)) |
| 2075 | { |
| 2076 | lwp->collecting_fast_tracepoint = r; |
| 2077 | |
| 2078 | if (r != fast_tpoint_collect_result::not_collecting) |
| 2079 | { |
| 2080 | if (r == fast_tpoint_collect_result::before_insn |
| 2081 | && lwp->exit_jump_pad_bkpt == NULL) |
| 2082 | { |
| 2083 | /* Haven't executed the original instruction yet. |
| 2084 | Set breakpoint there, and wait till it's hit, |
| 2085 | then single-step until exiting the jump pad. */ |
| 2086 | lwp->exit_jump_pad_bkpt |
| 2087 | = set_breakpoint_at (status.adjusted_insn_addr, NULL); |
| 2088 | } |
| 2089 | |
| 2090 | if (debug_threads) |
| 2091 | debug_printf ("Checking whether LWP %ld needs to move out of " |
| 2092 | "the jump pad...it does\n", |
| 2093 | lwpid_of (current_thread)); |
| 2094 | current_thread = saved_thread; |
| 2095 | |
| 2096 | return 1; |
| 2097 | } |
| 2098 | } |
| 2099 | else |
| 2100 | { |
| 2101 | /* If we get a synchronous signal while collecting, *and* |
| 2102 | while executing the (relocated) original instruction, |
| 2103 | reset the PC to point at the tpoint address, before |
| 2104 | reporting to GDB. Otherwise, it's an IPA lib bug: just |
| 2105 | report the signal to GDB, and pray for the best. */ |
| 2106 | |
| 2107 | lwp->collecting_fast_tracepoint |
| 2108 | = fast_tpoint_collect_result::not_collecting; |
| 2109 | |
| 2110 | if (r != fast_tpoint_collect_result::not_collecting |
| 2111 | && (status.adjusted_insn_addr <= lwp->stop_pc |
| 2112 | && lwp->stop_pc < status.adjusted_insn_addr_end)) |
| 2113 | { |
| 2114 | siginfo_t info; |
| 2115 | struct regcache *regcache; |
| 2116 | |
| 2117 | /* The si_addr on a few signals references the address |
| 2118 | of the faulting instruction. Adjust that as |
| 2119 | well. */ |
| 2120 | if ((WSTOPSIG (*wstat) == SIGILL |
| 2121 | || WSTOPSIG (*wstat) == SIGFPE |
| 2122 | || WSTOPSIG (*wstat) == SIGBUS |
| 2123 | || WSTOPSIG (*wstat) == SIGSEGV) |
| 2124 | && ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread), |
| 2125 | (PTRACE_TYPE_ARG3) 0, &info) == 0 |
| 2126 | /* Final check just to make sure we don't clobber |
| 2127 | the siginfo of non-kernel-sent signals. */ |
| 2128 | && (uintptr_t) info.si_addr == lwp->stop_pc) |
| 2129 | { |
| 2130 | info.si_addr = (void *) (uintptr_t) status.tpoint_addr; |
| 2131 | ptrace (PTRACE_SETSIGINFO, lwpid_of (current_thread), |
| 2132 | (PTRACE_TYPE_ARG3) 0, &info); |
| 2133 | } |
| 2134 | |
| 2135 | regcache = get_thread_regcache (current_thread, 1); |
| 2136 | (*the_low_target.set_pc) (regcache, status.tpoint_addr); |
| 2137 | lwp->stop_pc = status.tpoint_addr; |
| 2138 | |
| 2139 | /* Cancel any fast tracepoint lock this thread was |
| 2140 | holding. */ |
| 2141 | force_unlock_trace_buffer (); |
| 2142 | } |
| 2143 | |
| 2144 | if (lwp->exit_jump_pad_bkpt != NULL) |
| 2145 | { |
| 2146 | if (debug_threads) |
| 2147 | debug_printf ("Cancelling fast exit-jump-pad: removing bkpt. " |
| 2148 | "stopping all threads momentarily.\n"); |
| 2149 | |
| 2150 | stop_all_lwps (1, lwp); |
| 2151 | |
| 2152 | delete_breakpoint (lwp->exit_jump_pad_bkpt); |
| 2153 | lwp->exit_jump_pad_bkpt = NULL; |
| 2154 | |
| 2155 | unstop_all_lwps (1, lwp); |
| 2156 | |
| 2157 | gdb_assert (lwp->suspended >= 0); |
| 2158 | } |
| 2159 | } |
| 2160 | } |
| 2161 | |
| 2162 | if (debug_threads) |
| 2163 | debug_printf ("Checking whether LWP %ld needs to move out of the " |
| 2164 | "jump pad...no\n", |
| 2165 | lwpid_of (current_thread)); |
| 2166 | |
| 2167 | current_thread = saved_thread; |
| 2168 | return 0; |
| 2169 | } |
| 2170 | |
| 2171 | /* Enqueue one signal in the "signals to report later when out of the |
| 2172 | jump pad" list. */ |
| 2173 | |
| 2174 | static void |
| 2175 | enqueue_one_deferred_signal (struct lwp_info *lwp, int *wstat) |
| 2176 | { |
| 2177 | struct pending_signals *p_sig; |
| 2178 | struct thread_info *thread = get_lwp_thread (lwp); |
| 2179 | |
| 2180 | if (debug_threads) |
| 2181 | debug_printf ("Deferring signal %d for LWP %ld.\n", |
| 2182 | WSTOPSIG (*wstat), lwpid_of (thread)); |
| 2183 | |
| 2184 | if (debug_threads) |
| 2185 | { |
| 2186 | struct pending_signals *sig; |
| 2187 | |
| 2188 | for (sig = lwp->pending_signals_to_report; |
| 2189 | sig != NULL; |
| 2190 | sig = sig->prev) |
| 2191 | debug_printf (" Already queued %d\n", |
| 2192 | sig->signal); |
| 2193 | |
| 2194 | debug_printf (" (no more currently queued signals)\n"); |
| 2195 | } |
| 2196 | |
| 2197 | /* Don't enqueue non-RT signals if they are already in the deferred |
| 2198 | queue. (SIGSTOP being the easiest signal to see ending up here |
| 2199 | twice) */ |
| 2200 | if (WSTOPSIG (*wstat) < __SIGRTMIN) |
| 2201 | { |
| 2202 | struct pending_signals *sig; |
| 2203 | |
| 2204 | for (sig = lwp->pending_signals_to_report; |
| 2205 | sig != NULL; |
| 2206 | sig = sig->prev) |
| 2207 | { |
| 2208 | if (sig->signal == WSTOPSIG (*wstat)) |
| 2209 | { |
| 2210 | if (debug_threads) |
| 2211 | debug_printf ("Not requeuing already queued non-RT signal %d" |
| 2212 | " for LWP %ld\n", |
| 2213 | sig->signal, |
| 2214 | lwpid_of (thread)); |
| 2215 | return; |
| 2216 | } |
| 2217 | } |
| 2218 | } |
| 2219 | |
| 2220 | p_sig = XCNEW (struct pending_signals); |
| 2221 | p_sig->prev = lwp->pending_signals_to_report; |
| 2222 | p_sig->signal = WSTOPSIG (*wstat); |
| 2223 | |
| 2224 | ptrace (PTRACE_GETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0, |
| 2225 | &p_sig->info); |
| 2226 | |
| 2227 | lwp->pending_signals_to_report = p_sig; |
| 2228 | } |
| 2229 | |
| 2230 | /* Dequeue one signal from the "signals to report later when out of |
| 2231 | the jump pad" list. */ |
| 2232 | |
| 2233 | static int |
| 2234 | dequeue_one_deferred_signal (struct lwp_info *lwp, int *wstat) |
| 2235 | { |
| 2236 | struct thread_info *thread = get_lwp_thread (lwp); |
| 2237 | |
| 2238 | if (lwp->pending_signals_to_report != NULL) |
| 2239 | { |
| 2240 | struct pending_signals **p_sig; |
| 2241 | |
| 2242 | p_sig = &lwp->pending_signals_to_report; |
| 2243 | while ((*p_sig)->prev != NULL) |
| 2244 | p_sig = &(*p_sig)->prev; |
| 2245 | |
| 2246 | *wstat = W_STOPCODE ((*p_sig)->signal); |
| 2247 | if ((*p_sig)->info.si_signo != 0) |
| 2248 | ptrace (PTRACE_SETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0, |
| 2249 | &(*p_sig)->info); |
| 2250 | free (*p_sig); |
| 2251 | *p_sig = NULL; |
| 2252 | |
| 2253 | if (debug_threads) |
| 2254 | debug_printf ("Reporting deferred signal %d for LWP %ld.\n", |
| 2255 | WSTOPSIG (*wstat), lwpid_of (thread)); |
| 2256 | |
| 2257 | if (debug_threads) |
| 2258 | { |
| 2259 | struct pending_signals *sig; |
| 2260 | |
| 2261 | for (sig = lwp->pending_signals_to_report; |
| 2262 | sig != NULL; |
| 2263 | sig = sig->prev) |
| 2264 | debug_printf (" Still queued %d\n", |
| 2265 | sig->signal); |
| 2266 | |
| 2267 | debug_printf (" (no more queued signals)\n"); |
| 2268 | } |
| 2269 | |
| 2270 | return 1; |
| 2271 | } |
| 2272 | |
| 2273 | return 0; |
| 2274 | } |
| 2275 | |
| 2276 | /* Fetch the possibly triggered data watchpoint info and store it in |
| 2277 | CHILD. |
| 2278 | |
| 2279 | On some archs, like x86, that use debug registers to set |
| 2280 | watchpoints, it's possible that the way to know which watched |
| 2281 | address trapped, is to check the register that is used to select |
| 2282 | which address to watch. Problem is, between setting the watchpoint |
| 2283 | and reading back which data address trapped, the user may change |
| 2284 | the set of watchpoints, and, as a consequence, GDB changes the |
| 2285 | debug registers in the inferior. To avoid reading back a stale |
| 2286 | stopped-data-address when that happens, we cache in LP the fact |
| 2287 | that a watchpoint trapped, and the corresponding data address, as |
| 2288 | soon as we see CHILD stop with a SIGTRAP. If GDB changes the debug |
| 2289 | registers meanwhile, we have the cached data we can rely on. */ |
| 2290 | |
| 2291 | static int |
| 2292 | check_stopped_by_watchpoint (struct lwp_info *child) |
| 2293 | { |
| 2294 | if (the_low_target.stopped_by_watchpoint != NULL) |
| 2295 | { |
| 2296 | struct thread_info *saved_thread; |
| 2297 | |
| 2298 | saved_thread = current_thread; |
| 2299 | current_thread = get_lwp_thread (child); |
| 2300 | |
| 2301 | if (the_low_target.stopped_by_watchpoint ()) |
| 2302 | { |
| 2303 | child->stop_reason = TARGET_STOPPED_BY_WATCHPOINT; |
| 2304 | |
| 2305 | if (the_low_target.stopped_data_address != NULL) |
| 2306 | child->stopped_data_address |
| 2307 | = the_low_target.stopped_data_address (); |
| 2308 | else |
| 2309 | child->stopped_data_address = 0; |
| 2310 | } |
| 2311 | |
| 2312 | current_thread = saved_thread; |
| 2313 | } |
| 2314 | |
| 2315 | return child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
| 2316 | } |
| 2317 | |
| 2318 | /* Return the ptrace options that we want to try to enable. */ |
| 2319 | |
| 2320 | static int |
| 2321 | linux_low_ptrace_options (int attached) |
| 2322 | { |
| 2323 | client_state &cs = get_client_state (); |
| 2324 | int options = 0; |
| 2325 | |
| 2326 | if (!attached) |
| 2327 | options |= PTRACE_O_EXITKILL; |
| 2328 | |
| 2329 | if (cs.report_fork_events) |
| 2330 | options |= PTRACE_O_TRACEFORK; |
| 2331 | |
| 2332 | if (cs.report_vfork_events) |
| 2333 | options |= (PTRACE_O_TRACEVFORK | PTRACE_O_TRACEVFORKDONE); |
| 2334 | |
| 2335 | if (cs.report_exec_events) |
| 2336 | options |= PTRACE_O_TRACEEXEC; |
| 2337 | |
| 2338 | options |= PTRACE_O_TRACESYSGOOD; |
| 2339 | |
| 2340 | return options; |
| 2341 | } |
| 2342 | |
| 2343 | /* Do low-level handling of the event, and check if we should go on |
| 2344 | and pass it to caller code. Return the affected lwp if we are, or |
| 2345 | NULL otherwise. */ |
| 2346 | |
| 2347 | static struct lwp_info * |
| 2348 | linux_low_filter_event (int lwpid, int wstat) |
| 2349 | { |
| 2350 | client_state &cs = get_client_state (); |
| 2351 | struct lwp_info *child; |
| 2352 | struct thread_info *thread; |
| 2353 | int have_stop_pc = 0; |
| 2354 | |
| 2355 | child = find_lwp_pid (ptid_t (lwpid)); |
| 2356 | |
| 2357 | /* Check for stop events reported by a process we didn't already |
| 2358 | know about - anything not already in our LWP list. |
| 2359 | |
| 2360 | If we're expecting to receive stopped processes after |
| 2361 | fork, vfork, and clone events, then we'll just add the |
| 2362 | new one to our list and go back to waiting for the event |
| 2363 | to be reported - the stopped process might be returned |
| 2364 | from waitpid before or after the event is. |
| 2365 | |
| 2366 | But note the case of a non-leader thread exec'ing after the |
| 2367 | leader having exited, and gone from our lists (because |
| 2368 | check_zombie_leaders deleted it). The non-leader thread |
| 2369 | changes its tid to the tgid. */ |
| 2370 | |
| 2371 | if (WIFSTOPPED (wstat) && child == NULL && WSTOPSIG (wstat) == SIGTRAP |
| 2372 | && linux_ptrace_get_extended_event (wstat) == PTRACE_EVENT_EXEC) |
| 2373 | { |
| 2374 | ptid_t child_ptid; |
| 2375 | |
| 2376 | /* A multi-thread exec after we had seen the leader exiting. */ |
| 2377 | if (debug_threads) |
| 2378 | { |
| 2379 | debug_printf ("LLW: Re-adding thread group leader LWP %d" |
| 2380 | "after exec.\n", lwpid); |
| 2381 | } |
| 2382 | |
| 2383 | child_ptid = ptid_t (lwpid, lwpid, 0); |
| 2384 | child = add_lwp (child_ptid); |
| 2385 | child->stopped = 1; |
| 2386 | current_thread = child->thread; |
| 2387 | } |
| 2388 | |
| 2389 | /* If we didn't find a process, one of two things presumably happened: |
| 2390 | - A process we started and then detached from has exited. Ignore it. |
| 2391 | - A process we are controlling has forked and the new child's stop |
| 2392 | was reported to us by the kernel. Save its PID. */ |
| 2393 | if (child == NULL && WIFSTOPPED (wstat)) |
| 2394 | { |
| 2395 | add_to_pid_list (&stopped_pids, lwpid, wstat); |
| 2396 | return NULL; |
| 2397 | } |
| 2398 | else if (child == NULL) |
| 2399 | return NULL; |
| 2400 | |
| 2401 | thread = get_lwp_thread (child); |
| 2402 | |
| 2403 | child->stopped = 1; |
| 2404 | |
| 2405 | child->last_status = wstat; |
| 2406 | |
| 2407 | /* Check if the thread has exited. */ |
| 2408 | if ((WIFEXITED (wstat) || WIFSIGNALED (wstat))) |
| 2409 | { |
| 2410 | if (debug_threads) |
| 2411 | debug_printf ("LLFE: %d exited.\n", lwpid); |
| 2412 | |
| 2413 | if (finish_step_over (child)) |
| 2414 | { |
| 2415 | /* Unsuspend all other LWPs, and set them back running again. */ |
| 2416 | unsuspend_all_lwps (child); |
| 2417 | } |
| 2418 | |
| 2419 | /* If there is at least one more LWP, then the exit signal was |
| 2420 | not the end of the debugged application and should be |
| 2421 | ignored, unless GDB wants to hear about thread exits. */ |
| 2422 | if (cs.report_thread_events |
| 2423 | || last_thread_of_process_p (pid_of (thread))) |
| 2424 | { |
| 2425 | /* Since events are serialized to GDB core, and we can't |
| 2426 | report this one right now. Leave the status pending for |
| 2427 | the next time we're able to report it. */ |
| 2428 | mark_lwp_dead (child, wstat); |
| 2429 | return child; |
| 2430 | } |
| 2431 | else |
| 2432 | { |
| 2433 | delete_lwp (child); |
| 2434 | return NULL; |
| 2435 | } |
| 2436 | } |
| 2437 | |
| 2438 | gdb_assert (WIFSTOPPED (wstat)); |
| 2439 | |
| 2440 | if (WIFSTOPPED (wstat)) |
| 2441 | { |
| 2442 | struct process_info *proc; |
| 2443 | |
| 2444 | /* Architecture-specific setup after inferior is running. */ |
| 2445 | proc = find_process_pid (pid_of (thread)); |
| 2446 | if (proc->tdesc == NULL) |
| 2447 | { |
| 2448 | if (proc->attached) |
| 2449 | { |
| 2450 | /* This needs to happen after we have attached to the |
| 2451 | inferior and it is stopped for the first time, but |
| 2452 | before we access any inferior registers. */ |
| 2453 | linux_arch_setup_thread (thread); |
| 2454 | } |
| 2455 | else |
| 2456 | { |
| 2457 | /* The process is started, but GDBserver will do |
| 2458 | architecture-specific setup after the program stops at |
| 2459 | the first instruction. */ |
| 2460 | child->status_pending_p = 1; |
| 2461 | child->status_pending = wstat; |
| 2462 | return child; |
| 2463 | } |
| 2464 | } |
| 2465 | } |
| 2466 | |
| 2467 | if (WIFSTOPPED (wstat) && child->must_set_ptrace_flags) |
| 2468 | { |
| 2469 | struct process_info *proc = find_process_pid (pid_of (thread)); |
| 2470 | int options = linux_low_ptrace_options (proc->attached); |
| 2471 | |
| 2472 | linux_enable_event_reporting (lwpid, options); |
| 2473 | child->must_set_ptrace_flags = 0; |
| 2474 | } |
| 2475 | |
| 2476 | /* Always update syscall_state, even if it will be filtered later. */ |
| 2477 | if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SYSCALL_SIGTRAP) |
| 2478 | { |
| 2479 | child->syscall_state |
| 2480 | = (child->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY |
| 2481 | ? TARGET_WAITKIND_SYSCALL_RETURN |
| 2482 | : TARGET_WAITKIND_SYSCALL_ENTRY); |
| 2483 | } |
| 2484 | else |
| 2485 | { |
| 2486 | /* Almost all other ptrace-stops are known to be outside of system |
| 2487 | calls, with further exceptions in handle_extended_wait. */ |
| 2488 | child->syscall_state = TARGET_WAITKIND_IGNORE; |
| 2489 | } |
| 2490 | |
| 2491 | /* Be careful to not overwrite stop_pc until save_stop_reason is |
| 2492 | called. */ |
| 2493 | if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP |
| 2494 | && linux_is_extended_waitstatus (wstat)) |
| 2495 | { |
| 2496 | child->stop_pc = get_pc (child); |
| 2497 | if (handle_extended_wait (&child, wstat)) |
| 2498 | { |
| 2499 | /* The event has been handled, so just return without |
| 2500 | reporting it. */ |
| 2501 | return NULL; |
| 2502 | } |
| 2503 | } |
| 2504 | |
| 2505 | if (linux_wstatus_maybe_breakpoint (wstat)) |
| 2506 | { |
| 2507 | if (save_stop_reason (child)) |
| 2508 | have_stop_pc = 1; |
| 2509 | } |
| 2510 | |
| 2511 | if (!have_stop_pc) |
| 2512 | child->stop_pc = get_pc (child); |
| 2513 | |
| 2514 | if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGSTOP |
| 2515 | && child->stop_expected) |
| 2516 | { |
| 2517 | if (debug_threads) |
| 2518 | debug_printf ("Expected stop.\n"); |
| 2519 | child->stop_expected = 0; |
| 2520 | |
| 2521 | if (thread->last_resume_kind == resume_stop) |
| 2522 | { |
| 2523 | /* We want to report the stop to the core. Treat the |
| 2524 | SIGSTOP as a normal event. */ |
| 2525 | if (debug_threads) |
| 2526 | debug_printf ("LLW: resume_stop SIGSTOP caught for %s.\n", |
| 2527 | target_pid_to_str (ptid_of (thread))); |
| 2528 | } |
| 2529 | else if (stopping_threads != NOT_STOPPING_THREADS) |
| 2530 | { |
| 2531 | /* Stopping threads. We don't want this SIGSTOP to end up |
| 2532 | pending. */ |
| 2533 | if (debug_threads) |
| 2534 | debug_printf ("LLW: SIGSTOP caught for %s " |
| 2535 | "while stopping threads.\n", |
| 2536 | target_pid_to_str (ptid_of (thread))); |
| 2537 | return NULL; |
| 2538 | } |
| 2539 | else |
| 2540 | { |
| 2541 | /* This is a delayed SIGSTOP. Filter out the event. */ |
| 2542 | if (debug_threads) |
| 2543 | debug_printf ("LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n", |
| 2544 | child->stepping ? "step" : "continue", |
| 2545 | target_pid_to_str (ptid_of (thread))); |
| 2546 | |
| 2547 | linux_resume_one_lwp (child, child->stepping, 0, NULL); |
| 2548 | return NULL; |
| 2549 | } |
| 2550 | } |
| 2551 | |
| 2552 | child->status_pending_p = 1; |
| 2553 | child->status_pending = wstat; |
| 2554 | return child; |
| 2555 | } |
| 2556 | |
| 2557 | /* Return true if THREAD is doing hardware single step. */ |
| 2558 | |
| 2559 | static int |
| 2560 | maybe_hw_step (struct thread_info *thread) |
| 2561 | { |
| 2562 | if (can_hardware_single_step ()) |
| 2563 | return 1; |
| 2564 | else |
| 2565 | { |
| 2566 | /* GDBserver must insert single-step breakpoint for software |
| 2567 | single step. */ |
| 2568 | gdb_assert (has_single_step_breakpoints (thread)); |
| 2569 | return 0; |
| 2570 | } |
| 2571 | } |
| 2572 | |
| 2573 | /* Resume LWPs that are currently stopped without any pending status |
| 2574 | to report, but are resumed from the core's perspective. */ |
| 2575 | |
| 2576 | static void |
| 2577 | resume_stopped_resumed_lwps (thread_info *thread) |
| 2578 | { |
| 2579 | struct lwp_info *lp = get_thread_lwp (thread); |
| 2580 | |
| 2581 | if (lp->stopped |
| 2582 | && !lp->suspended |
| 2583 | && !lp->status_pending_p |
| 2584 | && thread->last_status.kind == TARGET_WAITKIND_IGNORE) |
| 2585 | { |
| 2586 | int step = 0; |
| 2587 | |
| 2588 | if (thread->last_resume_kind == resume_step) |
| 2589 | step = maybe_hw_step (thread); |
| 2590 | |
| 2591 | if (debug_threads) |
| 2592 | debug_printf ("RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n", |
| 2593 | target_pid_to_str (ptid_of (thread)), |
| 2594 | paddress (lp->stop_pc), |
| 2595 | step); |
| 2596 | |
| 2597 | linux_resume_one_lwp (lp, step, GDB_SIGNAL_0, NULL); |
| 2598 | } |
| 2599 | } |
| 2600 | |
| 2601 | /* Wait for an event from child(ren) WAIT_PTID, and return any that |
| 2602 | match FILTER_PTID (leaving others pending). The PTIDs can be: |
| 2603 | minus_one_ptid, to specify any child; a pid PTID, specifying all |
| 2604 | lwps of a thread group; or a PTID representing a single lwp. Store |
| 2605 | the stop status through the status pointer WSTAT. OPTIONS is |
| 2606 | passed to the waitpid call. Return 0 if no event was found and |
| 2607 | OPTIONS contains WNOHANG. Return -1 if no unwaited-for children |
| 2608 | was found. Return the PID of the stopped child otherwise. */ |
| 2609 | |
| 2610 | static int |
| 2611 | linux_wait_for_event_filtered (ptid_t wait_ptid, ptid_t filter_ptid, |
| 2612 | int *wstatp, int options) |
| 2613 | { |
| 2614 | struct thread_info *event_thread; |
| 2615 | struct lwp_info *event_child, *requested_child; |
| 2616 | sigset_t block_mask, prev_mask; |
| 2617 | |
| 2618 | retry: |
| 2619 | /* N.B. event_thread points to the thread_info struct that contains |
| 2620 | event_child. Keep them in sync. */ |
| 2621 | event_thread = NULL; |
| 2622 | event_child = NULL; |
| 2623 | requested_child = NULL; |
| 2624 | |
| 2625 | /* Check for a lwp with a pending status. */ |
| 2626 | |
| 2627 | if (filter_ptid == minus_one_ptid || filter_ptid.is_pid ()) |
| 2628 | { |
| 2629 | event_thread = find_thread_in_random ([&] (thread_info *thread) |
| 2630 | { |
| 2631 | return status_pending_p_callback (thread, filter_ptid); |
| 2632 | }); |
| 2633 | |
| 2634 | if (event_thread != NULL) |
| 2635 | event_child = get_thread_lwp (event_thread); |
| 2636 | if (debug_threads && event_thread) |
| 2637 | debug_printf ("Got a pending child %ld\n", lwpid_of (event_thread)); |
| 2638 | } |
| 2639 | else if (filter_ptid != null_ptid) |
| 2640 | { |
| 2641 | requested_child = find_lwp_pid (filter_ptid); |
| 2642 | |
| 2643 | if (stopping_threads == NOT_STOPPING_THREADS |
| 2644 | && requested_child->status_pending_p |
| 2645 | && (requested_child->collecting_fast_tracepoint |
| 2646 | != fast_tpoint_collect_result::not_collecting)) |
| 2647 | { |
| 2648 | enqueue_one_deferred_signal (requested_child, |
| 2649 | &requested_child->status_pending); |
| 2650 | requested_child->status_pending_p = 0; |
| 2651 | requested_child->status_pending = 0; |
| 2652 | linux_resume_one_lwp (requested_child, 0, 0, NULL); |
| 2653 | } |
| 2654 | |
| 2655 | if (requested_child->suspended |
| 2656 | && requested_child->status_pending_p) |
| 2657 | { |
| 2658 | internal_error (__FILE__, __LINE__, |
| 2659 | "requesting an event out of a" |
| 2660 | " suspended child?"); |
| 2661 | } |
| 2662 | |
| 2663 | if (requested_child->status_pending_p) |
| 2664 | { |
| 2665 | event_child = requested_child; |
| 2666 | event_thread = get_lwp_thread (event_child); |
| 2667 | } |
| 2668 | } |
| 2669 | |
| 2670 | if (event_child != NULL) |
| 2671 | { |
| 2672 | if (debug_threads) |
| 2673 | debug_printf ("Got an event from pending child %ld (%04x)\n", |
| 2674 | lwpid_of (event_thread), event_child->status_pending); |
| 2675 | *wstatp = event_child->status_pending; |
| 2676 | event_child->status_pending_p = 0; |
| 2677 | event_child->status_pending = 0; |
| 2678 | current_thread = event_thread; |
| 2679 | return lwpid_of (event_thread); |
| 2680 | } |
| 2681 | |
| 2682 | /* But if we don't find a pending event, we'll have to wait. |
| 2683 | |
| 2684 | We only enter this loop if no process has a pending wait status. |
| 2685 | Thus any action taken in response to a wait status inside this |
| 2686 | loop is responding as soon as we detect the status, not after any |
| 2687 | pending events. */ |
| 2688 | |
| 2689 | /* Make sure SIGCHLD is blocked until the sigsuspend below. Block |
| 2690 | all signals while here. */ |
| 2691 | sigfillset (&block_mask); |
| 2692 | sigprocmask (SIG_BLOCK, &block_mask, &prev_mask); |
| 2693 | |
| 2694 | /* Always pull all events out of the kernel. We'll randomly select |
| 2695 | an event LWP out of all that have events, to prevent |
| 2696 | starvation. */ |
| 2697 | while (event_child == NULL) |
| 2698 | { |
| 2699 | pid_t ret = 0; |
| 2700 | |
| 2701 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
| 2702 | quirks: |
| 2703 | |
| 2704 | - If the thread group leader exits while other threads in the |
| 2705 | thread group still exist, waitpid(TGID, ...) hangs. That |
| 2706 | waitpid won't return an exit status until the other threads |
| 2707 | in the group are reaped. |
| 2708 | |
| 2709 | - When a non-leader thread execs, that thread just vanishes |
| 2710 | without reporting an exit (so we'd hang if we waited for it |
| 2711 | explicitly in that case). The exec event is reported to |
| 2712 | the TGID pid. */ |
| 2713 | errno = 0; |
| 2714 | ret = my_waitpid (-1, wstatp, options | WNOHANG); |
| 2715 | |
| 2716 | if (debug_threads) |
| 2717 | debug_printf ("LWFE: waitpid(-1, ...) returned %d, %s\n", |
| 2718 | ret, errno ? strerror (errno) : "ERRNO-OK"); |
| 2719 | |
| 2720 | if (ret > 0) |
| 2721 | { |
| 2722 | if (debug_threads) |
| 2723 | { |
| 2724 | debug_printf ("LLW: waitpid %ld received %s\n", |
| 2725 | (long) ret, status_to_str (*wstatp)); |
| 2726 | } |
| 2727 | |
| 2728 | /* Filter all events. IOW, leave all events pending. We'll |
| 2729 | randomly select an event LWP out of all that have events |
| 2730 | below. */ |
| 2731 | linux_low_filter_event (ret, *wstatp); |
| 2732 | /* Retry until nothing comes out of waitpid. A single |
| 2733 | SIGCHLD can indicate more than one child stopped. */ |
| 2734 | continue; |
| 2735 | } |
| 2736 | |
| 2737 | /* Now that we've pulled all events out of the kernel, resume |
| 2738 | LWPs that don't have an interesting event to report. */ |
| 2739 | if (stopping_threads == NOT_STOPPING_THREADS) |
| 2740 | for_each_thread (resume_stopped_resumed_lwps); |
| 2741 | |
| 2742 | /* ... and find an LWP with a status to report to the core, if |
| 2743 | any. */ |
| 2744 | event_thread = find_thread_in_random ([&] (thread_info *thread) |
| 2745 | { |
| 2746 | return status_pending_p_callback (thread, filter_ptid); |
| 2747 | }); |
| 2748 | |
| 2749 | if (event_thread != NULL) |
| 2750 | { |
| 2751 | event_child = get_thread_lwp (event_thread); |
| 2752 | *wstatp = event_child->status_pending; |
| 2753 | event_child->status_pending_p = 0; |
| 2754 | event_child->status_pending = 0; |
| 2755 | break; |
| 2756 | } |
| 2757 | |
| 2758 | /* Check for zombie thread group leaders. Those can't be reaped |
| 2759 | until all other threads in the thread group are. */ |
| 2760 | check_zombie_leaders (); |
| 2761 | |
| 2762 | auto not_stopped = [&] (thread_info *thread) |
| 2763 | { |
| 2764 | return not_stopped_callback (thread, wait_ptid); |
| 2765 | }; |
| 2766 | |
| 2767 | /* If there are no resumed children left in the set of LWPs we |
| 2768 | want to wait for, bail. We can't just block in |
| 2769 | waitpid/sigsuspend, because lwps might have been left stopped |
| 2770 | in trace-stop state, and we'd be stuck forever waiting for |
| 2771 | their status to change (which would only happen if we resumed |
| 2772 | them). Even if WNOHANG is set, this return code is preferred |
| 2773 | over 0 (below), as it is more detailed. */ |
| 2774 | if (find_thread (not_stopped) == NULL) |
| 2775 | { |
| 2776 | if (debug_threads) |
| 2777 | debug_printf ("LLW: exit (no unwaited-for LWP)\n"); |
| 2778 | sigprocmask (SIG_SETMASK, &prev_mask, NULL); |
| 2779 | return -1; |
| 2780 | } |
| 2781 | |
| 2782 | /* No interesting event to report to the caller. */ |
| 2783 | if ((options & WNOHANG)) |
| 2784 | { |
| 2785 | if (debug_threads) |
| 2786 | debug_printf ("WNOHANG set, no event found\n"); |
| 2787 | |
| 2788 | sigprocmask (SIG_SETMASK, &prev_mask, NULL); |
| 2789 | return 0; |
| 2790 | } |
| 2791 | |
| 2792 | /* Block until we get an event reported with SIGCHLD. */ |
| 2793 | if (debug_threads) |
| 2794 | debug_printf ("sigsuspend'ing\n"); |
| 2795 | |
| 2796 | sigsuspend (&prev_mask); |
| 2797 | sigprocmask (SIG_SETMASK, &prev_mask, NULL); |
| 2798 | goto retry; |
| 2799 | } |
| 2800 | |
| 2801 | sigprocmask (SIG_SETMASK, &prev_mask, NULL); |
| 2802 | |
| 2803 | current_thread = event_thread; |
| 2804 | |
| 2805 | return lwpid_of (event_thread); |
| 2806 | } |
| 2807 | |
| 2808 | /* Wait for an event from child(ren) PTID. PTIDs can be: |
| 2809 | minus_one_ptid, to specify any child; a pid PTID, specifying all |
| 2810 | lwps of a thread group; or a PTID representing a single lwp. Store |
| 2811 | the stop status through the status pointer WSTAT. OPTIONS is |
| 2812 | passed to the waitpid call. Return 0 if no event was found and |
| 2813 | OPTIONS contains WNOHANG. Return -1 if no unwaited-for children |
| 2814 | was found. Return the PID of the stopped child otherwise. */ |
| 2815 | |
| 2816 | static int |
| 2817 | linux_wait_for_event (ptid_t ptid, int *wstatp, int options) |
| 2818 | { |
| 2819 | return linux_wait_for_event_filtered (ptid, ptid, wstatp, options); |
| 2820 | } |
| 2821 | |
| 2822 | /* Select one LWP out of those that have events pending. */ |
| 2823 | |
| 2824 | static void |
| 2825 | select_event_lwp (struct lwp_info **orig_lp) |
| 2826 | { |
| 2827 | struct thread_info *event_thread = NULL; |
| 2828 | |
| 2829 | /* In all-stop, give preference to the LWP that is being |
| 2830 | single-stepped. There will be at most one, and it's the LWP that |
| 2831 | the core is most interested in. If we didn't do this, then we'd |
| 2832 | have to handle pending step SIGTRAPs somehow in case the core |
| 2833 | later continues the previously-stepped thread, otherwise we'd |
| 2834 | report the pending SIGTRAP, and the core, not having stepped the |
| 2835 | thread, wouldn't understand what the trap was for, and therefore |
| 2836 | would report it to the user as a random signal. */ |
| 2837 | if (!non_stop) |
| 2838 | { |
| 2839 | event_thread = find_thread ([] (thread_info *thread) |
| 2840 | { |
| 2841 | lwp_info *lp = get_thread_lwp (thread); |
| 2842 | |
| 2843 | return (thread->last_status.kind == TARGET_WAITKIND_IGNORE |
| 2844 | && thread->last_resume_kind == resume_step |
| 2845 | && lp->status_pending_p); |
| 2846 | }); |
| 2847 | |
| 2848 | if (event_thread != NULL) |
| 2849 | { |
| 2850 | if (debug_threads) |
| 2851 | debug_printf ("SEL: Select single-step %s\n", |
| 2852 | target_pid_to_str (ptid_of (event_thread))); |
| 2853 | } |
| 2854 | } |
| 2855 | if (event_thread == NULL) |
| 2856 | { |
| 2857 | /* No single-stepping LWP. Select one at random, out of those |
| 2858 | which have had events. */ |
| 2859 | |
| 2860 | event_thread = find_thread_in_random ([&] (thread_info *thread) |
| 2861 | { |
| 2862 | lwp_info *lp = get_thread_lwp (thread); |
| 2863 | |
| 2864 | /* Only resumed LWPs that have an event pending. */ |
| 2865 | return (thread->last_status.kind == TARGET_WAITKIND_IGNORE |
| 2866 | && lp->status_pending_p); |
| 2867 | }); |
| 2868 | } |
| 2869 | |
| 2870 | if (event_thread != NULL) |
| 2871 | { |
| 2872 | struct lwp_info *event_lp = get_thread_lwp (event_thread); |
| 2873 | |
| 2874 | /* Switch the event LWP. */ |
| 2875 | *orig_lp = event_lp; |
| 2876 | } |
| 2877 | } |
| 2878 | |
| 2879 | /* Decrement the suspend count of all LWPs, except EXCEPT, if non |
| 2880 | NULL. */ |
| 2881 | |
| 2882 | static void |
| 2883 | unsuspend_all_lwps (struct lwp_info *except) |
| 2884 | { |
| 2885 | for_each_thread ([&] (thread_info *thread) |
| 2886 | { |
| 2887 | lwp_info *lwp = get_thread_lwp (thread); |
| 2888 | |
| 2889 | if (lwp != except) |
| 2890 | lwp_suspended_decr (lwp); |
| 2891 | }); |
| 2892 | } |
| 2893 | |
| 2894 | static void move_out_of_jump_pad_callback (thread_info *thread); |
| 2895 | static bool stuck_in_jump_pad_callback (thread_info *thread); |
| 2896 | static bool lwp_running (thread_info *thread); |
| 2897 | static ptid_t linux_wait_1 (ptid_t ptid, |
| 2898 | struct target_waitstatus *ourstatus, |
| 2899 | int target_options); |
| 2900 | |
| 2901 | /* Stabilize threads (move out of jump pads). |
| 2902 | |
| 2903 | If a thread is midway collecting a fast tracepoint, we need to |
| 2904 | finish the collection and move it out of the jump pad before |
| 2905 | reporting the signal. |
| 2906 | |
| 2907 | This avoids recursion while collecting (when a signal arrives |
| 2908 | midway, and the signal handler itself collects), which would trash |
| 2909 | the trace buffer. In case the user set a breakpoint in a signal |
| 2910 | handler, this avoids the backtrace showing the jump pad, etc.. |
| 2911 | Most importantly, there are certain things we can't do safely if |
| 2912 | threads are stopped in a jump pad (or in its callee's). For |
| 2913 | example: |
| 2914 | |
| 2915 | - starting a new trace run. A thread still collecting the |
| 2916 | previous run, could trash the trace buffer when resumed. The trace |
| 2917 | buffer control structures would have been reset but the thread had |
| 2918 | no way to tell. The thread could even midway memcpy'ing to the |
| 2919 | buffer, which would mean that when resumed, it would clobber the |
| 2920 | trace buffer that had been set for a new run. |
| 2921 | |
| 2922 | - we can't rewrite/reuse the jump pads for new tracepoints |
| 2923 | safely. Say you do tstart while a thread is stopped midway while |
| 2924 | collecting. When the thread is later resumed, it finishes the |
| 2925 | collection, and returns to the jump pad, to execute the original |
| 2926 | instruction that was under the tracepoint jump at the time the |
| 2927 | older run had been started. If the jump pad had been rewritten |
| 2928 | since for something else in the new run, the thread would now |
| 2929 | execute the wrong / random instructions. */ |
| 2930 | |
| 2931 | static void |
| 2932 | linux_stabilize_threads (void) |
| 2933 | { |
| 2934 | thread_info *thread_stuck = find_thread (stuck_in_jump_pad_callback); |
| 2935 | |
| 2936 | if (thread_stuck != NULL) |
| 2937 | { |
| 2938 | if (debug_threads) |
| 2939 | debug_printf ("can't stabilize, LWP %ld is stuck in jump pad\n", |
| 2940 | lwpid_of (thread_stuck)); |
| 2941 | return; |
| 2942 | } |
| 2943 | |
| 2944 | thread_info *saved_thread = current_thread; |
| 2945 | |
| 2946 | stabilizing_threads = 1; |
| 2947 | |
| 2948 | /* Kick 'em all. */ |
| 2949 | for_each_thread (move_out_of_jump_pad_callback); |
| 2950 | |
| 2951 | /* Loop until all are stopped out of the jump pads. */ |
| 2952 | while (find_thread (lwp_running) != NULL) |
| 2953 | { |
| 2954 | struct target_waitstatus ourstatus; |
| 2955 | struct lwp_info *lwp; |
| 2956 | int wstat; |
| 2957 | |
| 2958 | /* Note that we go through the full wait even loop. While |
| 2959 | moving threads out of jump pad, we need to be able to step |
| 2960 | over internal breakpoints and such. */ |
| 2961 | linux_wait_1 (minus_one_ptid, &ourstatus, 0); |
| 2962 | |
| 2963 | if (ourstatus.kind == TARGET_WAITKIND_STOPPED) |
| 2964 | { |
| 2965 | lwp = get_thread_lwp (current_thread); |
| 2966 | |
| 2967 | /* Lock it. */ |
| 2968 | lwp_suspended_inc (lwp); |
| 2969 | |
| 2970 | if (ourstatus.value.sig != GDB_SIGNAL_0 |
| 2971 | || current_thread->last_resume_kind == resume_stop) |
| 2972 | { |
| 2973 | wstat = W_STOPCODE (gdb_signal_to_host (ourstatus.value.sig)); |
| 2974 | enqueue_one_deferred_signal (lwp, &wstat); |
| 2975 | } |
| 2976 | } |
| 2977 | } |
| 2978 | |
| 2979 | unsuspend_all_lwps (NULL); |
| 2980 | |
| 2981 | stabilizing_threads = 0; |
| 2982 | |
| 2983 | current_thread = saved_thread; |
| 2984 | |
| 2985 | if (debug_threads) |
| 2986 | { |
| 2987 | thread_stuck = find_thread (stuck_in_jump_pad_callback); |
| 2988 | |
| 2989 | if (thread_stuck != NULL) |
| 2990 | debug_printf ("couldn't stabilize, LWP %ld got stuck in jump pad\n", |
| 2991 | lwpid_of (thread_stuck)); |
| 2992 | } |
| 2993 | } |
| 2994 | |
| 2995 | /* Convenience function that is called when the kernel reports an |
| 2996 | event that is not passed out to GDB. */ |
| 2997 | |
| 2998 | static ptid_t |
| 2999 | ignore_event (struct target_waitstatus *ourstatus) |
| 3000 | { |
| 3001 | /* If we got an event, there may still be others, as a single |
| 3002 | SIGCHLD can indicate more than one child stopped. This forces |
| 3003 | another target_wait call. */ |
| 3004 | async_file_mark (); |
| 3005 | |
| 3006 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
| 3007 | return null_ptid; |
| 3008 | } |
| 3009 | |
| 3010 | /* Convenience function that is called when the kernel reports an exit |
| 3011 | event. This decides whether to report the event to GDB as a |
| 3012 | process exit event, a thread exit event, or to suppress the |
| 3013 | event. */ |
| 3014 | |
| 3015 | static ptid_t |
| 3016 | filter_exit_event (struct lwp_info *event_child, |
| 3017 | struct target_waitstatus *ourstatus) |
| 3018 | { |
| 3019 | client_state &cs = get_client_state (); |
| 3020 | struct thread_info *thread = get_lwp_thread (event_child); |
| 3021 | ptid_t ptid = ptid_of (thread); |
| 3022 | |
| 3023 | if (!last_thread_of_process_p (pid_of (thread))) |
| 3024 | { |
| 3025 | if (cs.report_thread_events) |
| 3026 | ourstatus->kind = TARGET_WAITKIND_THREAD_EXITED; |
| 3027 | else |
| 3028 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
| 3029 | |
| 3030 | delete_lwp (event_child); |
| 3031 | } |
| 3032 | return ptid; |
| 3033 | } |
| 3034 | |
| 3035 | /* Returns 1 if GDB is interested in any event_child syscalls. */ |
| 3036 | |
| 3037 | static int |
| 3038 | gdb_catching_syscalls_p (struct lwp_info *event_child) |
| 3039 | { |
| 3040 | struct thread_info *thread = get_lwp_thread (event_child); |
| 3041 | struct process_info *proc = get_thread_process (thread); |
| 3042 | |
| 3043 | return !proc->syscalls_to_catch.empty (); |
| 3044 | } |
| 3045 | |
| 3046 | /* Returns 1 if GDB is interested in the event_child syscall. |
| 3047 | Only to be called when stopped reason is SYSCALL_SIGTRAP. */ |
| 3048 | |
| 3049 | static int |
| 3050 | gdb_catch_this_syscall_p (struct lwp_info *event_child) |
| 3051 | { |
| 3052 | int sysno; |
| 3053 | struct thread_info *thread = get_lwp_thread (event_child); |
| 3054 | struct process_info *proc = get_thread_process (thread); |
| 3055 | |
| 3056 | if (proc->syscalls_to_catch.empty ()) |
| 3057 | return 0; |
| 3058 | |
| 3059 | if (proc->syscalls_to_catch[0] == ANY_SYSCALL) |
| 3060 | return 1; |
| 3061 | |
| 3062 | get_syscall_trapinfo (event_child, &sysno); |
| 3063 | |
| 3064 | for (int iter : proc->syscalls_to_catch) |
| 3065 | if (iter == sysno) |
| 3066 | return 1; |
| 3067 | |
| 3068 | return 0; |
| 3069 | } |
| 3070 | |
| 3071 | /* Wait for process, returns status. */ |
| 3072 | |
| 3073 | static ptid_t |
| 3074 | linux_wait_1 (ptid_t ptid, |
| 3075 | struct target_waitstatus *ourstatus, int target_options) |
| 3076 | { |
| 3077 | client_state &cs = get_client_state (); |
| 3078 | int w; |
| 3079 | struct lwp_info *event_child; |
| 3080 | int options; |
| 3081 | int pid; |
| 3082 | int step_over_finished; |
| 3083 | int bp_explains_trap; |
| 3084 | int maybe_internal_trap; |
| 3085 | int report_to_gdb; |
| 3086 | int trace_event; |
| 3087 | int in_step_range; |
| 3088 | int any_resumed; |
| 3089 | |
| 3090 | if (debug_threads) |
| 3091 | { |
| 3092 | debug_enter (); |
| 3093 | debug_printf ("linux_wait_1: [%s]\n", target_pid_to_str (ptid)); |
| 3094 | } |
| 3095 | |
| 3096 | /* Translate generic target options into linux options. */ |
| 3097 | options = __WALL; |
| 3098 | if (target_options & TARGET_WNOHANG) |
| 3099 | options |= WNOHANG; |
| 3100 | |
| 3101 | bp_explains_trap = 0; |
| 3102 | trace_event = 0; |
| 3103 | in_step_range = 0; |
| 3104 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
| 3105 | |
| 3106 | auto status_pending_p_any = [&] (thread_info *thread) |
| 3107 | { |
| 3108 | return status_pending_p_callback (thread, minus_one_ptid); |
| 3109 | }; |
| 3110 | |
| 3111 | auto not_stopped = [&] (thread_info *thread) |
| 3112 | { |
| 3113 | return not_stopped_callback (thread, minus_one_ptid); |
| 3114 | }; |
| 3115 | |
| 3116 | /* Find a resumed LWP, if any. */ |
| 3117 | if (find_thread (status_pending_p_any) != NULL) |
| 3118 | any_resumed = 1; |
| 3119 | else if (find_thread (not_stopped) != NULL) |
| 3120 | any_resumed = 1; |
| 3121 | else |
| 3122 | any_resumed = 0; |
| 3123 | |
| 3124 | if (step_over_bkpt == null_ptid) |
| 3125 | pid = linux_wait_for_event (ptid, &w, options); |
| 3126 | else |
| 3127 | { |
| 3128 | if (debug_threads) |
| 3129 | debug_printf ("step_over_bkpt set [%s], doing a blocking wait\n", |
| 3130 | target_pid_to_str (step_over_bkpt)); |
| 3131 | pid = linux_wait_for_event (step_over_bkpt, &w, options & ~WNOHANG); |
| 3132 | } |
| 3133 | |
| 3134 | if (pid == 0 || (pid == -1 && !any_resumed)) |
| 3135 | { |
| 3136 | gdb_assert (target_options & TARGET_WNOHANG); |
| 3137 | |
| 3138 | if (debug_threads) |
| 3139 | { |
| 3140 | debug_printf ("linux_wait_1 ret = null_ptid, " |
| 3141 | "TARGET_WAITKIND_IGNORE\n"); |
| 3142 | debug_exit (); |
| 3143 | } |
| 3144 | |
| 3145 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
| 3146 | return null_ptid; |
| 3147 | } |
| 3148 | else if (pid == -1) |
| 3149 | { |
| 3150 | if (debug_threads) |
| 3151 | { |
| 3152 | debug_printf ("linux_wait_1 ret = null_ptid, " |
| 3153 | "TARGET_WAITKIND_NO_RESUMED\n"); |
| 3154 | debug_exit (); |
| 3155 | } |
| 3156 | |
| 3157 | ourstatus->kind = TARGET_WAITKIND_NO_RESUMED; |
| 3158 | return null_ptid; |
| 3159 | } |
| 3160 | |
| 3161 | event_child = get_thread_lwp (current_thread); |
| 3162 | |
| 3163 | /* linux_wait_for_event only returns an exit status for the last |
| 3164 | child of a process. Report it. */ |
| 3165 | if (WIFEXITED (w) || WIFSIGNALED (w)) |
| 3166 | { |
| 3167 | if (WIFEXITED (w)) |
| 3168 | { |
| 3169 | ourstatus->kind = TARGET_WAITKIND_EXITED; |
| 3170 | ourstatus->value.integer = WEXITSTATUS (w); |
| 3171 | |
| 3172 | if (debug_threads) |
| 3173 | { |
| 3174 | debug_printf ("linux_wait_1 ret = %s, exited with " |
| 3175 | "retcode %d\n", |
| 3176 | target_pid_to_str (ptid_of (current_thread)), |
| 3177 | WEXITSTATUS (w)); |
| 3178 | debug_exit (); |
| 3179 | } |
| 3180 | } |
| 3181 | else |
| 3182 | { |
| 3183 | ourstatus->kind = TARGET_WAITKIND_SIGNALLED; |
| 3184 | ourstatus->value.sig = gdb_signal_from_host (WTERMSIG (w)); |
| 3185 | |
| 3186 | if (debug_threads) |
| 3187 | { |
| 3188 | debug_printf ("linux_wait_1 ret = %s, terminated with " |
| 3189 | "signal %d\n", |
| 3190 | target_pid_to_str (ptid_of (current_thread)), |
| 3191 | WTERMSIG (w)); |
| 3192 | debug_exit (); |
| 3193 | } |
| 3194 | } |
| 3195 | |
| 3196 | if (ourstatus->kind == TARGET_WAITKIND_EXITED) |
| 3197 | return filter_exit_event (event_child, ourstatus); |
| 3198 | |
| 3199 | return ptid_of (current_thread); |
| 3200 | } |
| 3201 | |
| 3202 | /* If step-over executes a breakpoint instruction, in the case of a |
| 3203 | hardware single step it means a gdb/gdbserver breakpoint had been |
| 3204 | planted on top of a permanent breakpoint, in the case of a software |
| 3205 | single step it may just mean that gdbserver hit the reinsert breakpoint. |
| 3206 | The PC has been adjusted by save_stop_reason to point at |
| 3207 | the breakpoint address. |
| 3208 | So in the case of the hardware single step advance the PC manually |
| 3209 | past the breakpoint and in the case of software single step advance only |
| 3210 | if it's not the single_step_breakpoint we are hitting. |
| 3211 | This avoids that a program would keep trapping a permanent breakpoint |
| 3212 | forever. */ |
| 3213 | if (step_over_bkpt != null_ptid |
| 3214 | && event_child->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
| 3215 | && (event_child->stepping |
| 3216 | || !single_step_breakpoint_inserted_here (event_child->stop_pc))) |
| 3217 | { |
| 3218 | int increment_pc = 0; |
| 3219 | int breakpoint_kind = 0; |
| 3220 | CORE_ADDR stop_pc = event_child->stop_pc; |
| 3221 | |
| 3222 | breakpoint_kind = |
| 3223 | the_target->breakpoint_kind_from_current_state (&stop_pc); |
| 3224 | the_target->sw_breakpoint_from_kind (breakpoint_kind, &increment_pc); |
| 3225 | |
| 3226 | if (debug_threads) |
| 3227 | { |
| 3228 | debug_printf ("step-over for %s executed software breakpoint\n", |
| 3229 | target_pid_to_str (ptid_of (current_thread))); |
| 3230 | } |
| 3231 | |
| 3232 | if (increment_pc != 0) |
| 3233 | { |
| 3234 | struct regcache *regcache |
| 3235 | = get_thread_regcache (current_thread, 1); |
| 3236 | |
| 3237 | event_child->stop_pc += increment_pc; |
| 3238 | (*the_low_target.set_pc) (regcache, event_child->stop_pc); |
| 3239 | |
| 3240 | if (!(*the_low_target.breakpoint_at) (event_child->stop_pc)) |
| 3241 | event_child->stop_reason = TARGET_STOPPED_BY_NO_REASON; |
| 3242 | } |
| 3243 | } |
| 3244 | |
| 3245 | /* If this event was not handled before, and is not a SIGTRAP, we |
| 3246 | report it. SIGILL and SIGSEGV are also treated as traps in case |
| 3247 | a breakpoint is inserted at the current PC. If this target does |
| 3248 | not support internal breakpoints at all, we also report the |
| 3249 | SIGTRAP without further processing; it's of no concern to us. */ |
| 3250 | maybe_internal_trap |
| 3251 | = (supports_breakpoints () |
| 3252 | && (WSTOPSIG (w) == SIGTRAP |
| 3253 | || ((WSTOPSIG (w) == SIGILL |
| 3254 | || WSTOPSIG (w) == SIGSEGV) |
| 3255 | && (*the_low_target.breakpoint_at) (event_child->stop_pc)))); |
| 3256 | |
| 3257 | if (maybe_internal_trap) |
| 3258 | { |
| 3259 | /* Handle anything that requires bookkeeping before deciding to |
| 3260 | report the event or continue waiting. */ |
| 3261 | |
| 3262 | /* First check if we can explain the SIGTRAP with an internal |
| 3263 | breakpoint, or if we should possibly report the event to GDB. |
| 3264 | Do this before anything that may remove or insert a |
| 3265 | breakpoint. */ |
| 3266 | bp_explains_trap = breakpoint_inserted_here (event_child->stop_pc); |
| 3267 | |
| 3268 | /* We have a SIGTRAP, possibly a step-over dance has just |
| 3269 | finished. If so, tweak the state machine accordingly, |
| 3270 | reinsert breakpoints and delete any single-step |
| 3271 | breakpoints. */ |
| 3272 | step_over_finished = finish_step_over (event_child); |
| 3273 | |
| 3274 | /* Now invoke the callbacks of any internal breakpoints there. */ |
| 3275 | check_breakpoints (event_child->stop_pc); |
| 3276 | |
| 3277 | /* Handle tracepoint data collecting. This may overflow the |
| 3278 | trace buffer, and cause a tracing stop, removing |
| 3279 | breakpoints. */ |
| 3280 | trace_event = handle_tracepoints (event_child); |
| 3281 | |
| 3282 | if (bp_explains_trap) |
| 3283 | { |
| 3284 | if (debug_threads) |
| 3285 | debug_printf ("Hit a gdbserver breakpoint.\n"); |
| 3286 | } |
| 3287 | } |
| 3288 | else |
| 3289 | { |
| 3290 | /* We have some other signal, possibly a step-over dance was in |
| 3291 | progress, and it should be cancelled too. */ |
| 3292 | step_over_finished = finish_step_over (event_child); |
| 3293 | } |
| 3294 | |
| 3295 | /* We have all the data we need. Either report the event to GDB, or |
| 3296 | resume threads and keep waiting for more. */ |
| 3297 | |
| 3298 | /* If we're collecting a fast tracepoint, finish the collection and |
| 3299 | move out of the jump pad before delivering a signal. See |
| 3300 | linux_stabilize_threads. */ |
| 3301 | |
| 3302 | if (WIFSTOPPED (w) |
| 3303 | && WSTOPSIG (w) != SIGTRAP |
| 3304 | && supports_fast_tracepoints () |
| 3305 | && agent_loaded_p ()) |
| 3306 | { |
| 3307 | if (debug_threads) |
| 3308 | debug_printf ("Got signal %d for LWP %ld. Check if we need " |
| 3309 | "to defer or adjust it.\n", |
| 3310 | WSTOPSIG (w), lwpid_of (current_thread)); |
| 3311 | |
| 3312 | /* Allow debugging the jump pad itself. */ |
| 3313 | if (current_thread->last_resume_kind != resume_step |
| 3314 | && maybe_move_out_of_jump_pad (event_child, &w)) |
| 3315 | { |
| 3316 | enqueue_one_deferred_signal (event_child, &w); |
| 3317 | |
| 3318 | if (debug_threads) |
| 3319 | debug_printf ("Signal %d for LWP %ld deferred (in jump pad)\n", |
| 3320 | WSTOPSIG (w), lwpid_of (current_thread)); |
| 3321 | |
| 3322 | linux_resume_one_lwp (event_child, 0, 0, NULL); |
| 3323 | |
| 3324 | if (debug_threads) |
| 3325 | debug_exit (); |
| 3326 | return ignore_event (ourstatus); |
| 3327 | } |
| 3328 | } |
| 3329 | |
| 3330 | if (event_child->collecting_fast_tracepoint |
| 3331 | != fast_tpoint_collect_result::not_collecting) |
| 3332 | { |
| 3333 | if (debug_threads) |
| 3334 | debug_printf ("LWP %ld was trying to move out of the jump pad (%d). " |
| 3335 | "Check if we're already there.\n", |
| 3336 | lwpid_of (current_thread), |
| 3337 | (int) event_child->collecting_fast_tracepoint); |
| 3338 | |
| 3339 | trace_event = 1; |
| 3340 | |
| 3341 | event_child->collecting_fast_tracepoint |
| 3342 | = linux_fast_tracepoint_collecting (event_child, NULL); |
| 3343 | |
| 3344 | if (event_child->collecting_fast_tracepoint |
| 3345 | != fast_tpoint_collect_result::before_insn) |
| 3346 | { |
| 3347 | /* No longer need this breakpoint. */ |
| 3348 | if (event_child->exit_jump_pad_bkpt != NULL) |
| 3349 | { |
| 3350 | if (debug_threads) |
| 3351 | debug_printf ("No longer need exit-jump-pad bkpt; removing it." |
| 3352 | "stopping all threads momentarily.\n"); |
| 3353 | |
| 3354 | /* Other running threads could hit this breakpoint. |
| 3355 | We don't handle moribund locations like GDB does, |
| 3356 | instead we always pause all threads when removing |
| 3357 | breakpoints, so that any step-over or |
| 3358 | decr_pc_after_break adjustment is always taken |
| 3359 | care of while the breakpoint is still |
| 3360 | inserted. */ |
| 3361 | stop_all_lwps (1, event_child); |
| 3362 | |
| 3363 | delete_breakpoint (event_child->exit_jump_pad_bkpt); |
| 3364 | event_child->exit_jump_pad_bkpt = NULL; |
| 3365 | |
| 3366 | unstop_all_lwps (1, event_child); |
| 3367 | |
| 3368 | gdb_assert (event_child->suspended >= 0); |
| 3369 | } |
| 3370 | } |
| 3371 | |
| 3372 | if (event_child->collecting_fast_tracepoint |
| 3373 | == fast_tpoint_collect_result::not_collecting) |
| 3374 | { |
| 3375 | if (debug_threads) |
| 3376 | debug_printf ("fast tracepoint finished " |
| 3377 | "collecting successfully.\n"); |
| 3378 | |
| 3379 | /* We may have a deferred signal to report. */ |
| 3380 | if (dequeue_one_deferred_signal (event_child, &w)) |
| 3381 | { |
| 3382 | if (debug_threads) |
| 3383 | debug_printf ("dequeued one signal.\n"); |
| 3384 | } |
| 3385 | else |
| 3386 | { |
| 3387 | if (debug_threads) |
| 3388 | debug_printf ("no deferred signals.\n"); |
| 3389 | |
| 3390 | if (stabilizing_threads) |
| 3391 | { |
| 3392 | ourstatus->kind = TARGET_WAITKIND_STOPPED; |
| 3393 | ourstatus->value.sig = GDB_SIGNAL_0; |
| 3394 | |
| 3395 | if (debug_threads) |
| 3396 | { |
| 3397 | debug_printf ("linux_wait_1 ret = %s, stopped " |
| 3398 | "while stabilizing threads\n", |
| 3399 | target_pid_to_str (ptid_of (current_thread))); |
| 3400 | debug_exit (); |
| 3401 | } |
| 3402 | |
| 3403 | return ptid_of (current_thread); |
| 3404 | } |
| 3405 | } |
| 3406 | } |
| 3407 | } |
| 3408 | |
| 3409 | /* Check whether GDB would be interested in this event. */ |
| 3410 | |
| 3411 | /* Check if GDB is interested in this syscall. */ |
| 3412 | if (WIFSTOPPED (w) |
| 3413 | && WSTOPSIG (w) == SYSCALL_SIGTRAP |
| 3414 | && !gdb_catch_this_syscall_p (event_child)) |
| 3415 | { |
| 3416 | if (debug_threads) |
| 3417 | { |
| 3418 | debug_printf ("Ignored syscall for LWP %ld.\n", |
| 3419 | lwpid_of (current_thread)); |
| 3420 | } |
| 3421 | |
| 3422 | linux_resume_one_lwp (event_child, event_child->stepping, |
| 3423 | 0, NULL); |
| 3424 | |
| 3425 | if (debug_threads) |
| 3426 | debug_exit (); |
| 3427 | return ignore_event (ourstatus); |
| 3428 | } |
| 3429 | |
| 3430 | /* If GDB is not interested in this signal, don't stop other |
| 3431 | threads, and don't report it to GDB. Just resume the inferior |
| 3432 | right away. We do this for threading-related signals as well as |
| 3433 | any that GDB specifically requested we ignore. But never ignore |
| 3434 | SIGSTOP if we sent it ourselves, and do not ignore signals when |
| 3435 | stepping - they may require special handling to skip the signal |
| 3436 | handler. Also never ignore signals that could be caused by a |
| 3437 | breakpoint. */ |
| 3438 | if (WIFSTOPPED (w) |
| 3439 | && current_thread->last_resume_kind != resume_step |
| 3440 | && ( |
| 3441 | #if defined (USE_THREAD_DB) && !defined (__ANDROID__) |
| 3442 | (current_process ()->priv->thread_db != NULL |
| 3443 | && (WSTOPSIG (w) == __SIGRTMIN |
| 3444 | || WSTOPSIG (w) == __SIGRTMIN + 1)) |
| 3445 | || |
| 3446 | #endif |
| 3447 | (cs.pass_signals[gdb_signal_from_host (WSTOPSIG (w))] |
| 3448 | && !(WSTOPSIG (w) == SIGSTOP |
| 3449 | && current_thread->last_resume_kind == resume_stop) |
| 3450 | && !linux_wstatus_maybe_breakpoint (w)))) |
| 3451 | { |
| 3452 | siginfo_t info, *info_p; |
| 3453 | |
| 3454 | if (debug_threads) |
| 3455 | debug_printf ("Ignored signal %d for LWP %ld.\n", |
| 3456 | WSTOPSIG (w), lwpid_of (current_thread)); |
| 3457 | |
| 3458 | if (ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread), |
| 3459 | (PTRACE_TYPE_ARG3) 0, &info) == 0) |
| 3460 | info_p = &info; |
| 3461 | else |
| 3462 | info_p = NULL; |
| 3463 | |
| 3464 | if (step_over_finished) |
| 3465 | { |
| 3466 | /* We cancelled this thread's step-over above. We still |
| 3467 | need to unsuspend all other LWPs, and set them back |
| 3468 | running again while the signal handler runs. */ |
| 3469 | unsuspend_all_lwps (event_child); |
| 3470 | |
| 3471 | /* Enqueue the pending signal info so that proceed_all_lwps |
| 3472 | doesn't lose it. */ |
| 3473 | enqueue_pending_signal (event_child, WSTOPSIG (w), info_p); |
| 3474 | |
| 3475 | proceed_all_lwps (); |
| 3476 | } |
| 3477 | else |
| 3478 | { |
| 3479 | linux_resume_one_lwp (event_child, event_child->stepping, |
| 3480 | WSTOPSIG (w), info_p); |
| 3481 | } |
| 3482 | |
| 3483 | if (debug_threads) |
| 3484 | debug_exit (); |
| 3485 | |
| 3486 | return ignore_event (ourstatus); |
| 3487 | } |
| 3488 | |
| 3489 | /* Note that all addresses are always "out of the step range" when |
| 3490 | there's no range to begin with. */ |
| 3491 | in_step_range = lwp_in_step_range (event_child); |
| 3492 | |
| 3493 | /* If GDB wanted this thread to single step, and the thread is out |
| 3494 | of the step range, we always want to report the SIGTRAP, and let |
| 3495 | GDB handle it. Watchpoints should always be reported. So should |
| 3496 | signals we can't explain. A SIGTRAP we can't explain could be a |
| 3497 | GDB breakpoint --- we may or not support Z0 breakpoints. If we |
| 3498 | do, we're be able to handle GDB breakpoints on top of internal |
| 3499 | breakpoints, by handling the internal breakpoint and still |
| 3500 | reporting the event to GDB. If we don't, we're out of luck, GDB |
| 3501 | won't see the breakpoint hit. If we see a single-step event but |
| 3502 | the thread should be continuing, don't pass the trap to gdb. |
| 3503 | That indicates that we had previously finished a single-step but |
| 3504 | left the single-step pending -- see |
| 3505 | complete_ongoing_step_over. */ |
| 3506 | report_to_gdb = (!maybe_internal_trap |
| 3507 | || (current_thread->last_resume_kind == resume_step |
| 3508 | && !in_step_range) |
| 3509 | || event_child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT |
| 3510 | || (!in_step_range |
| 3511 | && !bp_explains_trap |
| 3512 | && !trace_event |
| 3513 | && !step_over_finished |
| 3514 | && !(current_thread->last_resume_kind == resume_continue |
| 3515 | && event_child->stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)) |
| 3516 | || (gdb_breakpoint_here (event_child->stop_pc) |
| 3517 | && gdb_condition_true_at_breakpoint (event_child->stop_pc) |
| 3518 | && gdb_no_commands_at_breakpoint (event_child->stop_pc)) |
| 3519 | || event_child->waitstatus.kind != TARGET_WAITKIND_IGNORE); |
| 3520 | |
| 3521 | run_breakpoint_commands (event_child->stop_pc); |
| 3522 | |
| 3523 | /* We found no reason GDB would want us to stop. We either hit one |
| 3524 | of our own breakpoints, or finished an internal step GDB |
| 3525 | shouldn't know about. */ |
| 3526 | if (!report_to_gdb) |
| 3527 | { |
| 3528 | if (debug_threads) |
| 3529 | { |
| 3530 | if (bp_explains_trap) |
| 3531 | debug_printf ("Hit a gdbserver breakpoint.\n"); |
| 3532 | if (step_over_finished) |
| 3533 | debug_printf ("Step-over finished.\n"); |
| 3534 | if (trace_event) |
| 3535 | debug_printf ("Tracepoint event.\n"); |
| 3536 | if (lwp_in_step_range (event_child)) |
| 3537 | debug_printf ("Range stepping pc 0x%s [0x%s, 0x%s).\n", |
| 3538 | paddress (event_child->stop_pc), |
| 3539 | paddress (event_child->step_range_start), |
| 3540 | paddress (event_child->step_range_end)); |
| 3541 | } |
| 3542 | |
| 3543 | /* We're not reporting this breakpoint to GDB, so apply the |
| 3544 | decr_pc_after_break adjustment to the inferior's regcache |
| 3545 | ourselves. */ |
| 3546 | |
| 3547 | if (the_low_target.set_pc != NULL) |
| 3548 | { |
| 3549 | struct regcache *regcache |
| 3550 | = get_thread_regcache (current_thread, 1); |
| 3551 | (*the_low_target.set_pc) (regcache, event_child->stop_pc); |
| 3552 | } |
| 3553 | |
| 3554 | if (step_over_finished) |
| 3555 | { |
| 3556 | /* If we have finished stepping over a breakpoint, we've |
| 3557 | stopped and suspended all LWPs momentarily except the |
| 3558 | stepping one. This is where we resume them all again. |
| 3559 | We're going to keep waiting, so use proceed, which |
| 3560 | handles stepping over the next breakpoint. */ |
| 3561 | unsuspend_all_lwps (event_child); |
| 3562 | } |
| 3563 | else |
| 3564 | { |
| 3565 | /* Remove the single-step breakpoints if any. Note that |
| 3566 | there isn't single-step breakpoint if we finished stepping |
| 3567 | over. */ |
| 3568 | if (can_software_single_step () |
| 3569 | && has_single_step_breakpoints (current_thread)) |
| 3570 | { |
| 3571 | stop_all_lwps (0, event_child); |
| 3572 | delete_single_step_breakpoints (current_thread); |
| 3573 | unstop_all_lwps (0, event_child); |
| 3574 | } |
| 3575 | } |
| 3576 | |
| 3577 | if (debug_threads) |
| 3578 | debug_printf ("proceeding all threads.\n"); |
| 3579 | proceed_all_lwps (); |
| 3580 | |
| 3581 | if (debug_threads) |
| 3582 | debug_exit (); |
| 3583 | |
| 3584 | return ignore_event (ourstatus); |
| 3585 | } |
| 3586 | |
| 3587 | if (debug_threads) |
| 3588 | { |
| 3589 | if (event_child->waitstatus.kind != TARGET_WAITKIND_IGNORE) |
| 3590 | { |
| 3591 | std::string str |
| 3592 | = target_waitstatus_to_string (&event_child->waitstatus); |
| 3593 | |
| 3594 | debug_printf ("LWP %ld: extended event with waitstatus %s\n", |
| 3595 | lwpid_of (get_lwp_thread (event_child)), str.c_str ()); |
| 3596 | } |
| 3597 | if (current_thread->last_resume_kind == resume_step) |
| 3598 | { |
| 3599 | if (event_child->step_range_start == event_child->step_range_end) |
| 3600 | debug_printf ("GDB wanted to single-step, reporting event.\n"); |
| 3601 | else if (!lwp_in_step_range (event_child)) |
| 3602 | debug_printf ("Out of step range, reporting event.\n"); |
| 3603 | } |
| 3604 | if (event_child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT) |
| 3605 | debug_printf ("Stopped by watchpoint.\n"); |
| 3606 | else if (gdb_breakpoint_here (event_child->stop_pc)) |
| 3607 | debug_printf ("Stopped by GDB breakpoint.\n"); |
| 3608 | if (debug_threads) |
| 3609 | debug_printf ("Hit a non-gdbserver trap event.\n"); |
| 3610 | } |
| 3611 | |
| 3612 | /* Alright, we're going to report a stop. */ |
| 3613 | |
| 3614 | /* Remove single-step breakpoints. */ |
| 3615 | if (can_software_single_step ()) |
| 3616 | { |
| 3617 | /* Remove single-step breakpoints or not. It it is true, stop all |
| 3618 | lwps, so that other threads won't hit the breakpoint in the |
| 3619 | staled memory. */ |
| 3620 | int remove_single_step_breakpoints_p = 0; |
| 3621 | |
| 3622 | if (non_stop) |
| 3623 | { |
| 3624 | remove_single_step_breakpoints_p |
| 3625 | = has_single_step_breakpoints (current_thread); |
| 3626 | } |
| 3627 | else |
| 3628 | { |
| 3629 | /* In all-stop, a stop reply cancels all previous resume |
| 3630 | requests. Delete all single-step breakpoints. */ |
| 3631 | |
| 3632 | find_thread ([&] (thread_info *thread) { |
| 3633 | if (has_single_step_breakpoints (thread)) |
| 3634 | { |
| 3635 | remove_single_step_breakpoints_p = 1; |
| 3636 | return true; |
| 3637 | } |
| 3638 | |
| 3639 | return false; |
| 3640 | }); |
| 3641 | } |
| 3642 | |
| 3643 | if (remove_single_step_breakpoints_p) |
| 3644 | { |
| 3645 | /* If we remove single-step breakpoints from memory, stop all lwps, |
| 3646 | so that other threads won't hit the breakpoint in the staled |
| 3647 | memory. */ |
| 3648 | stop_all_lwps (0, event_child); |
| 3649 | |
| 3650 | if (non_stop) |
| 3651 | { |
| 3652 | gdb_assert (has_single_step_breakpoints (current_thread)); |
| 3653 | delete_single_step_breakpoints (current_thread); |
| 3654 | } |
| 3655 | else |
| 3656 | { |
| 3657 | for_each_thread ([] (thread_info *thread){ |
| 3658 | if (has_single_step_breakpoints (thread)) |
| 3659 | delete_single_step_breakpoints (thread); |
| 3660 | }); |
| 3661 | } |
| 3662 | |
| 3663 | unstop_all_lwps (0, event_child); |
| 3664 | } |
| 3665 | } |
| 3666 | |
| 3667 | if (!stabilizing_threads) |
| 3668 | { |
| 3669 | /* In all-stop, stop all threads. */ |
| 3670 | if (!non_stop) |
| 3671 | stop_all_lwps (0, NULL); |
| 3672 | |
| 3673 | if (step_over_finished) |
| 3674 | { |
| 3675 | if (!non_stop) |
| 3676 | { |
| 3677 | /* If we were doing a step-over, all other threads but |
| 3678 | the stepping one had been paused in start_step_over, |
| 3679 | with their suspend counts incremented. We don't want |
| 3680 | to do a full unstop/unpause, because we're in |
| 3681 | all-stop mode (so we want threads stopped), but we |
| 3682 | still need to unsuspend the other threads, to |
| 3683 | decrement their `suspended' count back. */ |
| 3684 | unsuspend_all_lwps (event_child); |
| 3685 | } |
| 3686 | else |
| 3687 | { |
| 3688 | /* If we just finished a step-over, then all threads had |
| 3689 | been momentarily paused. In all-stop, that's fine, |
| 3690 | we want threads stopped by now anyway. In non-stop, |
| 3691 | we need to re-resume threads that GDB wanted to be |
| 3692 | running. */ |
| 3693 | unstop_all_lwps (1, event_child); |
| 3694 | } |
| 3695 | } |
| 3696 | |
| 3697 | /* If we're not waiting for a specific LWP, choose an event LWP |
| 3698 | from among those that have had events. Giving equal priority |
| 3699 | to all LWPs that have had events helps prevent |
| 3700 | starvation. */ |
| 3701 | if (ptid == minus_one_ptid) |
| 3702 | { |
| 3703 | event_child->status_pending_p = 1; |
| 3704 | event_child->status_pending = w; |
| 3705 | |
| 3706 | select_event_lwp (&event_child); |
| 3707 | |
| 3708 | /* current_thread and event_child must stay in sync. */ |
| 3709 | current_thread = get_lwp_thread (event_child); |
| 3710 | |
| 3711 | event_child->status_pending_p = 0; |
| 3712 | w = event_child->status_pending; |
| 3713 | } |
| 3714 | |
| 3715 | |
| 3716 | /* Stabilize threads (move out of jump pads). */ |
| 3717 | if (!non_stop) |
| 3718 | stabilize_threads (); |
| 3719 | } |
| 3720 | else |
| 3721 | { |
| 3722 | /* If we just finished a step-over, then all threads had been |
| 3723 | momentarily paused. In all-stop, that's fine, we want |
| 3724 | threads stopped by now anyway. In non-stop, we need to |
| 3725 | re-resume threads that GDB wanted to be running. */ |
| 3726 | if (step_over_finished) |
| 3727 | unstop_all_lwps (1, event_child); |
| 3728 | } |
| 3729 | |
| 3730 | if (event_child->waitstatus.kind != TARGET_WAITKIND_IGNORE) |
| 3731 | { |
| 3732 | /* If the reported event is an exit, fork, vfork or exec, let |
| 3733 | GDB know. */ |
| 3734 | |
| 3735 | /* Break the unreported fork relationship chain. */ |
| 3736 | if (event_child->waitstatus.kind == TARGET_WAITKIND_FORKED |
| 3737 | || event_child->waitstatus.kind == TARGET_WAITKIND_VFORKED) |
| 3738 | { |
| 3739 | event_child->fork_relative->fork_relative = NULL; |
| 3740 | event_child->fork_relative = NULL; |
| 3741 | } |
| 3742 | |
| 3743 | *ourstatus = event_child->waitstatus; |
| 3744 | /* Clear the event lwp's waitstatus since we handled it already. */ |
| 3745 | event_child->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
| 3746 | } |
| 3747 | else |
| 3748 | ourstatus->kind = TARGET_WAITKIND_STOPPED; |
| 3749 | |
| 3750 | /* Now that we've selected our final event LWP, un-adjust its PC if |
| 3751 | it was a software breakpoint, and the client doesn't know we can |
| 3752 | adjust the breakpoint ourselves. */ |
| 3753 | if (event_child->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
| 3754 | && !cs.swbreak_feature) |
| 3755 | { |
| 3756 | int decr_pc = the_low_target.decr_pc_after_break; |
| 3757 | |
| 3758 | if (decr_pc != 0) |
| 3759 | { |
| 3760 | struct regcache *regcache |
| 3761 | = get_thread_regcache (current_thread, 1); |
| 3762 | (*the_low_target.set_pc) (regcache, event_child->stop_pc + decr_pc); |
| 3763 | } |
| 3764 | } |
| 3765 | |
| 3766 | if (WSTOPSIG (w) == SYSCALL_SIGTRAP) |
| 3767 | { |
| 3768 | get_syscall_trapinfo (event_child, |
| 3769 | &ourstatus->value.syscall_number); |
| 3770 | ourstatus->kind = event_child->syscall_state; |
| 3771 | } |
| 3772 | else if (current_thread->last_resume_kind == resume_stop |
| 3773 | && WSTOPSIG (w) == SIGSTOP) |
| 3774 | { |
| 3775 | /* A thread that has been requested to stop by GDB with vCont;t, |
| 3776 | and it stopped cleanly, so report as SIG0. The use of |
| 3777 | SIGSTOP is an implementation detail. */ |
| 3778 | ourstatus->value.sig = GDB_SIGNAL_0; |
| 3779 | } |
| 3780 | else if (current_thread->last_resume_kind == resume_stop |
| 3781 | && WSTOPSIG (w) != SIGSTOP) |
| 3782 | { |
| 3783 | /* A thread that has been requested to stop by GDB with vCont;t, |
| 3784 | but, it stopped for other reasons. */ |
| 3785 | ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w)); |
| 3786 | } |
| 3787 | else if (ourstatus->kind == TARGET_WAITKIND_STOPPED) |
| 3788 | { |
| 3789 | ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w)); |
| 3790 | } |
| 3791 | |
| 3792 | gdb_assert (step_over_bkpt == null_ptid); |
| 3793 | |
| 3794 | if (debug_threads) |
| 3795 | { |
| 3796 | debug_printf ("linux_wait_1 ret = %s, %d, %d\n", |
| 3797 | target_pid_to_str (ptid_of (current_thread)), |
| 3798 | ourstatus->kind, ourstatus->value.sig); |
| 3799 | debug_exit (); |
| 3800 | } |
| 3801 | |
| 3802 | if (ourstatus->kind == TARGET_WAITKIND_EXITED) |
| 3803 | return filter_exit_event (event_child, ourstatus); |
| 3804 | |
| 3805 | return ptid_of (current_thread); |
| 3806 | } |
| 3807 | |
| 3808 | /* Get rid of any pending event in the pipe. */ |
| 3809 | static void |
| 3810 | async_file_flush (void) |
| 3811 | { |
| 3812 | int ret; |
| 3813 | char buf; |
| 3814 | |
| 3815 | do |
| 3816 | ret = read (linux_event_pipe[0], &buf, 1); |
| 3817 | while (ret >= 0 || (ret == -1 && errno == EINTR)); |
| 3818 | } |
| 3819 | |
| 3820 | /* Put something in the pipe, so the event loop wakes up. */ |
| 3821 | static void |
| 3822 | async_file_mark (void) |
| 3823 | { |
| 3824 | int ret; |
| 3825 | |
| 3826 | async_file_flush (); |
| 3827 | |
| 3828 | do |
| 3829 | ret = write (linux_event_pipe[1], "+", 1); |
| 3830 | while (ret == 0 || (ret == -1 && errno == EINTR)); |
| 3831 | |
| 3832 | /* Ignore EAGAIN. If the pipe is full, the event loop will already |
| 3833 | be awakened anyway. */ |
| 3834 | } |
| 3835 | |
| 3836 | static ptid_t |
| 3837 | linux_wait (ptid_t ptid, |
| 3838 | struct target_waitstatus *ourstatus, int target_options) |
| 3839 | { |
| 3840 | ptid_t event_ptid; |
| 3841 | |
| 3842 | /* Flush the async file first. */ |
| 3843 | if (target_is_async_p ()) |
| 3844 | async_file_flush (); |
| 3845 | |
| 3846 | do |
| 3847 | { |
| 3848 | event_ptid = linux_wait_1 (ptid, ourstatus, target_options); |
| 3849 | } |
| 3850 | while ((target_options & TARGET_WNOHANG) == 0 |
| 3851 | && event_ptid == null_ptid |
| 3852 | && ourstatus->kind == TARGET_WAITKIND_IGNORE); |
| 3853 | |
| 3854 | /* If at least one stop was reported, there may be more. A single |
| 3855 | SIGCHLD can signal more than one child stop. */ |
| 3856 | if (target_is_async_p () |
| 3857 | && (target_options & TARGET_WNOHANG) != 0 |
| 3858 | && event_ptid != null_ptid) |
| 3859 | async_file_mark (); |
| 3860 | |
| 3861 | return event_ptid; |
| 3862 | } |
| 3863 | |
| 3864 | /* Send a signal to an LWP. */ |
| 3865 | |
| 3866 | static int |
| 3867 | kill_lwp (unsigned long lwpid, int signo) |
| 3868 | { |
| 3869 | int ret; |
| 3870 | |
| 3871 | errno = 0; |
| 3872 | ret = syscall (__NR_tkill, lwpid, signo); |
| 3873 | if (errno == ENOSYS) |
| 3874 | { |
| 3875 | /* If tkill fails, then we are not using nptl threads, a |
| 3876 | configuration we no longer support. */ |
| 3877 | perror_with_name (("tkill")); |
| 3878 | } |
| 3879 | return ret; |
| 3880 | } |
| 3881 | |
| 3882 | void |
| 3883 | linux_stop_lwp (struct lwp_info *lwp) |
| 3884 | { |
| 3885 | send_sigstop (lwp); |
| 3886 | } |
| 3887 | |
| 3888 | static void |
| 3889 | send_sigstop (struct lwp_info *lwp) |
| 3890 | { |
| 3891 | int pid; |
| 3892 | |
| 3893 | pid = lwpid_of (get_lwp_thread (lwp)); |
| 3894 | |
| 3895 | /* If we already have a pending stop signal for this process, don't |
| 3896 | send another. */ |
| 3897 | if (lwp->stop_expected) |
| 3898 | { |
| 3899 | if (debug_threads) |
| 3900 | debug_printf ("Have pending sigstop for lwp %d\n", pid); |
| 3901 | |
| 3902 | return; |
| 3903 | } |
| 3904 | |
| 3905 | if (debug_threads) |
| 3906 | debug_printf ("Sending sigstop to lwp %d\n", pid); |
| 3907 | |
| 3908 | lwp->stop_expected = 1; |
| 3909 | kill_lwp (pid, SIGSTOP); |
| 3910 | } |
| 3911 | |
| 3912 | static void |
| 3913 | send_sigstop (thread_info *thread, lwp_info *except) |
| 3914 | { |
| 3915 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 3916 | |
| 3917 | /* Ignore EXCEPT. */ |
| 3918 | if (lwp == except) |
| 3919 | return; |
| 3920 | |
| 3921 | if (lwp->stopped) |
| 3922 | return; |
| 3923 | |
| 3924 | send_sigstop (lwp); |
| 3925 | } |
| 3926 | |
| 3927 | /* Increment the suspend count of an LWP, and stop it, if not stopped |
| 3928 | yet. */ |
| 3929 | static void |
| 3930 | suspend_and_send_sigstop (thread_info *thread, lwp_info *except) |
| 3931 | { |
| 3932 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 3933 | |
| 3934 | /* Ignore EXCEPT. */ |
| 3935 | if (lwp == except) |
| 3936 | return; |
| 3937 | |
| 3938 | lwp_suspended_inc (lwp); |
| 3939 | |
| 3940 | send_sigstop (thread, except); |
| 3941 | } |
| 3942 | |
| 3943 | static void |
| 3944 | mark_lwp_dead (struct lwp_info *lwp, int wstat) |
| 3945 | { |
| 3946 | /* Store the exit status for later. */ |
| 3947 | lwp->status_pending_p = 1; |
| 3948 | lwp->status_pending = wstat; |
| 3949 | |
| 3950 | /* Store in waitstatus as well, as there's nothing else to process |
| 3951 | for this event. */ |
| 3952 | if (WIFEXITED (wstat)) |
| 3953 | { |
| 3954 | lwp->waitstatus.kind = TARGET_WAITKIND_EXITED; |
| 3955 | lwp->waitstatus.value.integer = WEXITSTATUS (wstat); |
| 3956 | } |
| 3957 | else if (WIFSIGNALED (wstat)) |
| 3958 | { |
| 3959 | lwp->waitstatus.kind = TARGET_WAITKIND_SIGNALLED; |
| 3960 | lwp->waitstatus.value.sig = gdb_signal_from_host (WTERMSIG (wstat)); |
| 3961 | } |
| 3962 | |
| 3963 | /* Prevent trying to stop it. */ |
| 3964 | lwp->stopped = 1; |
| 3965 | |
| 3966 | /* No further stops are expected from a dead lwp. */ |
| 3967 | lwp->stop_expected = 0; |
| 3968 | } |
| 3969 | |
| 3970 | /* Return true if LWP has exited already, and has a pending exit event |
| 3971 | to report to GDB. */ |
| 3972 | |
| 3973 | static int |
| 3974 | lwp_is_marked_dead (struct lwp_info *lwp) |
| 3975 | { |
| 3976 | return (lwp->status_pending_p |
| 3977 | && (WIFEXITED (lwp->status_pending) |
| 3978 | || WIFSIGNALED (lwp->status_pending))); |
| 3979 | } |
| 3980 | |
| 3981 | /* Wait for all children to stop for the SIGSTOPs we just queued. */ |
| 3982 | |
| 3983 | static void |
| 3984 | wait_for_sigstop (void) |
| 3985 | { |
| 3986 | struct thread_info *saved_thread; |
| 3987 | ptid_t saved_tid; |
| 3988 | int wstat; |
| 3989 | int ret; |
| 3990 | |
| 3991 | saved_thread = current_thread; |
| 3992 | if (saved_thread != NULL) |
| 3993 | saved_tid = saved_thread->id; |
| 3994 | else |
| 3995 | saved_tid = null_ptid; /* avoid bogus unused warning */ |
| 3996 | |
| 3997 | if (debug_threads) |
| 3998 | debug_printf ("wait_for_sigstop: pulling events\n"); |
| 3999 | |
| 4000 | /* Passing NULL_PTID as filter indicates we want all events to be |
| 4001 | left pending. Eventually this returns when there are no |
| 4002 | unwaited-for children left. */ |
| 4003 | ret = linux_wait_for_event_filtered (minus_one_ptid, null_ptid, |
| 4004 | &wstat, __WALL); |
| 4005 | gdb_assert (ret == -1); |
| 4006 | |
| 4007 | if (saved_thread == NULL || linux_thread_alive (saved_tid)) |
| 4008 | current_thread = saved_thread; |
| 4009 | else |
| 4010 | { |
| 4011 | if (debug_threads) |
| 4012 | debug_printf ("Previously current thread died.\n"); |
| 4013 | |
| 4014 | /* We can't change the current inferior behind GDB's back, |
| 4015 | otherwise, a subsequent command may apply to the wrong |
| 4016 | process. */ |
| 4017 | current_thread = NULL; |
| 4018 | } |
| 4019 | } |
| 4020 | |
| 4021 | /* Returns true if THREAD is stopped in a jump pad, and we can't |
| 4022 | move it out, because we need to report the stop event to GDB. For |
| 4023 | example, if the user puts a breakpoint in the jump pad, it's |
| 4024 | because she wants to debug it. */ |
| 4025 | |
| 4026 | static bool |
| 4027 | stuck_in_jump_pad_callback (thread_info *thread) |
| 4028 | { |
| 4029 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 4030 | |
| 4031 | if (lwp->suspended != 0) |
| 4032 | { |
| 4033 | internal_error (__FILE__, __LINE__, |
| 4034 | "LWP %ld is suspended, suspended=%d\n", |
| 4035 | lwpid_of (thread), lwp->suspended); |
| 4036 | } |
| 4037 | gdb_assert (lwp->stopped); |
| 4038 | |
| 4039 | /* Allow debugging the jump pad, gdb_collect, etc.. */ |
| 4040 | return (supports_fast_tracepoints () |
| 4041 | && agent_loaded_p () |
| 4042 | && (gdb_breakpoint_here (lwp->stop_pc) |
| 4043 | || lwp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT |
| 4044 | || thread->last_resume_kind == resume_step) |
| 4045 | && (linux_fast_tracepoint_collecting (lwp, NULL) |
| 4046 | != fast_tpoint_collect_result::not_collecting)); |
| 4047 | } |
| 4048 | |
| 4049 | static void |
| 4050 | move_out_of_jump_pad_callback (thread_info *thread) |
| 4051 | { |
| 4052 | struct thread_info *saved_thread; |
| 4053 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 4054 | int *wstat; |
| 4055 | |
| 4056 | if (lwp->suspended != 0) |
| 4057 | { |
| 4058 | internal_error (__FILE__, __LINE__, |
| 4059 | "LWP %ld is suspended, suspended=%d\n", |
| 4060 | lwpid_of (thread), lwp->suspended); |
| 4061 | } |
| 4062 | gdb_assert (lwp->stopped); |
| 4063 | |
| 4064 | /* For gdb_breakpoint_here. */ |
| 4065 | saved_thread = current_thread; |
| 4066 | current_thread = thread; |
| 4067 | |
| 4068 | wstat = lwp->status_pending_p ? &lwp->status_pending : NULL; |
| 4069 | |
| 4070 | /* Allow debugging the jump pad, gdb_collect, etc. */ |
| 4071 | if (!gdb_breakpoint_here (lwp->stop_pc) |
| 4072 | && lwp->stop_reason != TARGET_STOPPED_BY_WATCHPOINT |
| 4073 | && thread->last_resume_kind != resume_step |
| 4074 | && maybe_move_out_of_jump_pad (lwp, wstat)) |
| 4075 | { |
| 4076 | if (debug_threads) |
| 4077 | debug_printf ("LWP %ld needs stabilizing (in jump pad)\n", |
| 4078 | lwpid_of (thread)); |
| 4079 | |
| 4080 | if (wstat) |
| 4081 | { |
| 4082 | lwp->status_pending_p = 0; |
| 4083 | enqueue_one_deferred_signal (lwp, wstat); |
| 4084 | |
| 4085 | if (debug_threads) |
| 4086 | debug_printf ("Signal %d for LWP %ld deferred " |
| 4087 | "(in jump pad)\n", |
| 4088 | WSTOPSIG (*wstat), lwpid_of (thread)); |
| 4089 | } |
| 4090 | |
| 4091 | linux_resume_one_lwp (lwp, 0, 0, NULL); |
| 4092 | } |
| 4093 | else |
| 4094 | lwp_suspended_inc (lwp); |
| 4095 | |
| 4096 | current_thread = saved_thread; |
| 4097 | } |
| 4098 | |
| 4099 | static bool |
| 4100 | lwp_running (thread_info *thread) |
| 4101 | { |
| 4102 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 4103 | |
| 4104 | if (lwp_is_marked_dead (lwp)) |
| 4105 | return false; |
| 4106 | |
| 4107 | return !lwp->stopped; |
| 4108 | } |
| 4109 | |
| 4110 | /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL. |
| 4111 | If SUSPEND, then also increase the suspend count of every LWP, |
| 4112 | except EXCEPT. */ |
| 4113 | |
| 4114 | static void |
| 4115 | stop_all_lwps (int suspend, struct lwp_info *except) |
| 4116 | { |
| 4117 | /* Should not be called recursively. */ |
| 4118 | gdb_assert (stopping_threads == NOT_STOPPING_THREADS); |
| 4119 | |
| 4120 | if (debug_threads) |
| 4121 | { |
| 4122 | debug_enter (); |
| 4123 | debug_printf ("stop_all_lwps (%s, except=%s)\n", |
| 4124 | suspend ? "stop-and-suspend" : "stop", |
| 4125 | except != NULL |
| 4126 | ? target_pid_to_str (ptid_of (get_lwp_thread (except))) |
| 4127 | : "none"); |
| 4128 | } |
| 4129 | |
| 4130 | stopping_threads = (suspend |
| 4131 | ? STOPPING_AND_SUSPENDING_THREADS |
| 4132 | : STOPPING_THREADS); |
| 4133 | |
| 4134 | if (suspend) |
| 4135 | for_each_thread ([&] (thread_info *thread) |
| 4136 | { |
| 4137 | suspend_and_send_sigstop (thread, except); |
| 4138 | }); |
| 4139 | else |
| 4140 | for_each_thread ([&] (thread_info *thread) |
| 4141 | { |
| 4142 | send_sigstop (thread, except); |
| 4143 | }); |
| 4144 | |
| 4145 | wait_for_sigstop (); |
| 4146 | stopping_threads = NOT_STOPPING_THREADS; |
| 4147 | |
| 4148 | if (debug_threads) |
| 4149 | { |
| 4150 | debug_printf ("stop_all_lwps done, setting stopping_threads " |
| 4151 | "back to !stopping\n"); |
| 4152 | debug_exit (); |
| 4153 | } |
| 4154 | } |
| 4155 | |
| 4156 | /* Enqueue one signal in the chain of signals which need to be |
| 4157 | delivered to this process on next resume. */ |
| 4158 | |
| 4159 | static void |
| 4160 | enqueue_pending_signal (struct lwp_info *lwp, int signal, siginfo_t *info) |
| 4161 | { |
| 4162 | struct pending_signals *p_sig = XNEW (struct pending_signals); |
| 4163 | |
| 4164 | p_sig->prev = lwp->pending_signals; |
| 4165 | p_sig->signal = signal; |
| 4166 | if (info == NULL) |
| 4167 | memset (&p_sig->info, 0, sizeof (siginfo_t)); |
| 4168 | else |
| 4169 | memcpy (&p_sig->info, info, sizeof (siginfo_t)); |
| 4170 | lwp->pending_signals = p_sig; |
| 4171 | } |
| 4172 | |
| 4173 | /* Install breakpoints for software single stepping. */ |
| 4174 | |
| 4175 | static void |
| 4176 | install_software_single_step_breakpoints (struct lwp_info *lwp) |
| 4177 | { |
| 4178 | struct thread_info *thread = get_lwp_thread (lwp); |
| 4179 | struct regcache *regcache = get_thread_regcache (thread, 1); |
| 4180 | |
| 4181 | scoped_restore save_current_thread = make_scoped_restore (¤t_thread); |
| 4182 | |
| 4183 | current_thread = thread; |
| 4184 | std::vector<CORE_ADDR> next_pcs = the_low_target.get_next_pcs (regcache); |
| 4185 | |
| 4186 | for (CORE_ADDR pc : next_pcs) |
| 4187 | set_single_step_breakpoint (pc, current_ptid); |
| 4188 | } |
| 4189 | |
| 4190 | /* Single step via hardware or software single step. |
| 4191 | Return 1 if hardware single stepping, 0 if software single stepping |
| 4192 | or can't single step. */ |
| 4193 | |
| 4194 | static int |
| 4195 | single_step (struct lwp_info* lwp) |
| 4196 | { |
| 4197 | int step = 0; |
| 4198 | |
| 4199 | if (can_hardware_single_step ()) |
| 4200 | { |
| 4201 | step = 1; |
| 4202 | } |
| 4203 | else if (can_software_single_step ()) |
| 4204 | { |
| 4205 | install_software_single_step_breakpoints (lwp); |
| 4206 | step = 0; |
| 4207 | } |
| 4208 | else |
| 4209 | { |
| 4210 | if (debug_threads) |
| 4211 | debug_printf ("stepping is not implemented on this target"); |
| 4212 | } |
| 4213 | |
| 4214 | return step; |
| 4215 | } |
| 4216 | |
| 4217 | /* The signal can be delivered to the inferior if we are not trying to |
| 4218 | finish a fast tracepoint collect. Since signal can be delivered in |
| 4219 | the step-over, the program may go to signal handler and trap again |
| 4220 | after return from the signal handler. We can live with the spurious |
| 4221 | double traps. */ |
| 4222 | |
| 4223 | static int |
| 4224 | lwp_signal_can_be_delivered (struct lwp_info *lwp) |
| 4225 | { |
| 4226 | return (lwp->collecting_fast_tracepoint |
| 4227 | == fast_tpoint_collect_result::not_collecting); |
| 4228 | } |
| 4229 | |
| 4230 | /* Resume execution of LWP. If STEP is nonzero, single-step it. If |
| 4231 | SIGNAL is nonzero, give it that signal. */ |
| 4232 | |
| 4233 | static void |
| 4234 | linux_resume_one_lwp_throw (struct lwp_info *lwp, |
| 4235 | int step, int signal, siginfo_t *info) |
| 4236 | { |
| 4237 | struct thread_info *thread = get_lwp_thread (lwp); |
| 4238 | struct thread_info *saved_thread; |
| 4239 | int ptrace_request; |
| 4240 | struct process_info *proc = get_thread_process (thread); |
| 4241 | |
| 4242 | /* Note that target description may not be initialised |
| 4243 | (proc->tdesc == NULL) at this point because the program hasn't |
| 4244 | stopped at the first instruction yet. It means GDBserver skips |
| 4245 | the extra traps from the wrapper program (see option --wrapper). |
| 4246 | Code in this function that requires register access should be |
| 4247 | guarded by proc->tdesc == NULL or something else. */ |
| 4248 | |
| 4249 | if (lwp->stopped == 0) |
| 4250 | return; |
| 4251 | |
| 4252 | gdb_assert (lwp->waitstatus.kind == TARGET_WAITKIND_IGNORE); |
| 4253 | |
| 4254 | fast_tpoint_collect_result fast_tp_collecting |
| 4255 | = lwp->collecting_fast_tracepoint; |
| 4256 | |
| 4257 | gdb_assert (!stabilizing_threads |
| 4258 | || (fast_tp_collecting |
| 4259 | != fast_tpoint_collect_result::not_collecting)); |
| 4260 | |
| 4261 | /* Cancel actions that rely on GDB not changing the PC (e.g., the |
| 4262 | user used the "jump" command, or "set $pc = foo"). */ |
| 4263 | if (thread->while_stepping != NULL && lwp->stop_pc != get_pc (lwp)) |
| 4264 | { |
| 4265 | /* Collecting 'while-stepping' actions doesn't make sense |
| 4266 | anymore. */ |
| 4267 | release_while_stepping_state_list (thread); |
| 4268 | } |
| 4269 | |
| 4270 | /* If we have pending signals or status, and a new signal, enqueue the |
| 4271 | signal. Also enqueue the signal if it can't be delivered to the |
| 4272 | inferior right now. */ |
| 4273 | if (signal != 0 |
| 4274 | && (lwp->status_pending_p |
| 4275 | || lwp->pending_signals != NULL |
| 4276 | || !lwp_signal_can_be_delivered (lwp))) |
| 4277 | { |
| 4278 | enqueue_pending_signal (lwp, signal, info); |
| 4279 | |
| 4280 | /* Postpone any pending signal. It was enqueued above. */ |
| 4281 | signal = 0; |
| 4282 | } |
| 4283 | |
| 4284 | if (lwp->status_pending_p) |
| 4285 | { |
| 4286 | if (debug_threads) |
| 4287 | debug_printf ("Not resuming lwp %ld (%s, stop %s);" |
| 4288 | " has pending status\n", |
| 4289 | lwpid_of (thread), step ? "step" : "continue", |
| 4290 | lwp->stop_expected ? "expected" : "not expected"); |
| 4291 | return; |
| 4292 | } |
| 4293 | |
| 4294 | saved_thread = current_thread; |
| 4295 | current_thread = thread; |
| 4296 | |
| 4297 | /* This bit needs some thinking about. If we get a signal that |
| 4298 | we must report while a single-step reinsert is still pending, |
| 4299 | we often end up resuming the thread. It might be better to |
| 4300 | (ew) allow a stack of pending events; then we could be sure that |
| 4301 | the reinsert happened right away and not lose any signals. |
| 4302 | |
| 4303 | Making this stack would also shrink the window in which breakpoints are |
| 4304 | uninserted (see comment in linux_wait_for_lwp) but not enough for |
| 4305 | complete correctness, so it won't solve that problem. It may be |
| 4306 | worthwhile just to solve this one, however. */ |
| 4307 | if (lwp->bp_reinsert != 0) |
| 4308 | { |
| 4309 | if (debug_threads) |
| 4310 | debug_printf (" pending reinsert at 0x%s\n", |
| 4311 | paddress (lwp->bp_reinsert)); |
| 4312 | |
| 4313 | if (can_hardware_single_step ()) |
| 4314 | { |
| 4315 | if (fast_tp_collecting == fast_tpoint_collect_result::not_collecting) |
| 4316 | { |
| 4317 | if (step == 0) |
| 4318 | warning ("BAD - reinserting but not stepping."); |
| 4319 | if (lwp->suspended) |
| 4320 | warning ("BAD - reinserting and suspended(%d).", |
| 4321 | lwp->suspended); |
| 4322 | } |
| 4323 | } |
| 4324 | |
| 4325 | step = maybe_hw_step (thread); |
| 4326 | } |
| 4327 | |
| 4328 | if (fast_tp_collecting == fast_tpoint_collect_result::before_insn) |
| 4329 | { |
| 4330 | if (debug_threads) |
| 4331 | debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad" |
| 4332 | " (exit-jump-pad-bkpt)\n", |
| 4333 | lwpid_of (thread)); |
| 4334 | } |
| 4335 | else if (fast_tp_collecting == fast_tpoint_collect_result::at_insn) |
| 4336 | { |
| 4337 | if (debug_threads) |
| 4338 | debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad" |
| 4339 | " single-stepping\n", |
| 4340 | lwpid_of (thread)); |
| 4341 | |
| 4342 | if (can_hardware_single_step ()) |
| 4343 | step = 1; |
| 4344 | else |
| 4345 | { |
| 4346 | internal_error (__FILE__, __LINE__, |
| 4347 | "moving out of jump pad single-stepping" |
| 4348 | " not implemented on this target"); |
| 4349 | } |
| 4350 | } |
| 4351 | |
| 4352 | /* If we have while-stepping actions in this thread set it stepping. |
| 4353 | If we have a signal to deliver, it may or may not be set to |
| 4354 | SIG_IGN, we don't know. Assume so, and allow collecting |
| 4355 | while-stepping into a signal handler. A possible smart thing to |
| 4356 | do would be to set an internal breakpoint at the signal return |
| 4357 | address, continue, and carry on catching this while-stepping |
| 4358 | action only when that breakpoint is hit. A future |
| 4359 | enhancement. */ |
| 4360 | if (thread->while_stepping != NULL) |
| 4361 | { |
| 4362 | if (debug_threads) |
| 4363 | debug_printf ("lwp %ld has a while-stepping action -> forcing step.\n", |
| 4364 | lwpid_of (thread)); |
| 4365 | |
| 4366 | step = single_step (lwp); |
| 4367 | } |
| 4368 | |
| 4369 | if (proc->tdesc != NULL && the_low_target.get_pc != NULL) |
| 4370 | { |
| 4371 | struct regcache *regcache = get_thread_regcache (current_thread, 1); |
| 4372 | |
| 4373 | lwp->stop_pc = (*the_low_target.get_pc) (regcache); |
| 4374 | |
| 4375 | if (debug_threads) |
| 4376 | { |
| 4377 | debug_printf (" %s from pc 0x%lx\n", step ? "step" : "continue", |
| 4378 | (long) lwp->stop_pc); |
| 4379 | } |
| 4380 | } |
| 4381 | |
| 4382 | /* If we have pending signals, consume one if it can be delivered to |
| 4383 | the inferior. */ |
| 4384 | if (lwp->pending_signals != NULL && lwp_signal_can_be_delivered (lwp)) |
| 4385 | { |
| 4386 | struct pending_signals **p_sig; |
| 4387 | |
| 4388 | p_sig = &lwp->pending_signals; |
| 4389 | while ((*p_sig)->prev != NULL) |
| 4390 | p_sig = &(*p_sig)->prev; |
| 4391 | |
| 4392 | signal = (*p_sig)->signal; |
| 4393 | if ((*p_sig)->info.si_signo != 0) |
| 4394 | ptrace (PTRACE_SETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0, |
| 4395 | &(*p_sig)->info); |
| 4396 | |
| 4397 | free (*p_sig); |
| 4398 | *p_sig = NULL; |
| 4399 | } |
| 4400 | |
| 4401 | if (debug_threads) |
| 4402 | debug_printf ("Resuming lwp %ld (%s, signal %d, stop %s)\n", |
| 4403 | lwpid_of (thread), step ? "step" : "continue", signal, |
| 4404 | lwp->stop_expected ? "expected" : "not expected"); |
| 4405 | |
| 4406 | if (the_low_target.prepare_to_resume != NULL) |
| 4407 | the_low_target.prepare_to_resume (lwp); |
| 4408 | |
| 4409 | regcache_invalidate_thread (thread); |
| 4410 | errno = 0; |
| 4411 | lwp->stepping = step; |
| 4412 | if (step) |
| 4413 | ptrace_request = PTRACE_SINGLESTEP; |
| 4414 | else if (gdb_catching_syscalls_p (lwp)) |
| 4415 | ptrace_request = PTRACE_SYSCALL; |
| 4416 | else |
| 4417 | ptrace_request = PTRACE_CONT; |
| 4418 | ptrace (ptrace_request, |
| 4419 | lwpid_of (thread), |
| 4420 | (PTRACE_TYPE_ARG3) 0, |
| 4421 | /* Coerce to a uintptr_t first to avoid potential gcc warning |
| 4422 | of coercing an 8 byte integer to a 4 byte pointer. */ |
| 4423 | (PTRACE_TYPE_ARG4) (uintptr_t) signal); |
| 4424 | |
| 4425 | current_thread = saved_thread; |
| 4426 | if (errno) |
| 4427 | perror_with_name ("resuming thread"); |
| 4428 | |
| 4429 | /* Successfully resumed. Clear state that no longer makes sense, |
| 4430 | and mark the LWP as running. Must not do this before resuming |
| 4431 | otherwise if that fails other code will be confused. E.g., we'd |
| 4432 | later try to stop the LWP and hang forever waiting for a stop |
| 4433 | status. Note that we must not throw after this is cleared, |
| 4434 | otherwise handle_zombie_lwp_error would get confused. */ |
| 4435 | lwp->stopped = 0; |
| 4436 | lwp->stop_reason = TARGET_STOPPED_BY_NO_REASON; |
| 4437 | } |
| 4438 | |
| 4439 | /* Called when we try to resume a stopped LWP and that errors out. If |
| 4440 | the LWP is no longer in ptrace-stopped state (meaning it's zombie, |
| 4441 | or about to become), discard the error, clear any pending status |
| 4442 | the LWP may have, and return true (we'll collect the exit status |
| 4443 | soon enough). Otherwise, return false. */ |
| 4444 | |
| 4445 | static int |
| 4446 | check_ptrace_stopped_lwp_gone (struct lwp_info *lp) |
| 4447 | { |
| 4448 | struct thread_info *thread = get_lwp_thread (lp); |
| 4449 | |
| 4450 | /* If we get an error after resuming the LWP successfully, we'd |
| 4451 | confuse !T state for the LWP being gone. */ |
| 4452 | gdb_assert (lp->stopped); |
| 4453 | |
| 4454 | /* We can't just check whether the LWP is in 'Z (Zombie)' state, |
| 4455 | because even if ptrace failed with ESRCH, the tracee may be "not |
| 4456 | yet fully dead", but already refusing ptrace requests. In that |
| 4457 | case the tracee has 'R (Running)' state for a little bit |
| 4458 | (observed in Linux 3.18). See also the note on ESRCH in the |
| 4459 | ptrace(2) man page. Instead, check whether the LWP has any state |
| 4460 | other than ptrace-stopped. */ |
| 4461 | |
| 4462 | /* Don't assume anything if /proc/PID/status can't be read. */ |
| 4463 | if (linux_proc_pid_is_trace_stopped_nowarn (lwpid_of (thread)) == 0) |
| 4464 | { |
| 4465 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; |
| 4466 | lp->status_pending_p = 0; |
| 4467 | return 1; |
| 4468 | } |
| 4469 | return 0; |
| 4470 | } |
| 4471 | |
| 4472 | /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP |
| 4473 | disappears while we try to resume it. */ |
| 4474 | |
| 4475 | static void |
| 4476 | linux_resume_one_lwp (struct lwp_info *lwp, |
| 4477 | int step, int signal, siginfo_t *info) |
| 4478 | { |
| 4479 | try |
| 4480 | { |
| 4481 | linux_resume_one_lwp_throw (lwp, step, signal, info); |
| 4482 | } |
| 4483 | catch (const gdb_exception_error &ex) |
| 4484 | { |
| 4485 | if (!check_ptrace_stopped_lwp_gone (lwp)) |
| 4486 | throw; |
| 4487 | } |
| 4488 | } |
| 4489 | |
| 4490 | /* This function is called once per thread via for_each_thread. |
| 4491 | We look up which resume request applies to THREAD and mark it with a |
| 4492 | pointer to the appropriate resume request. |
| 4493 | |
| 4494 | This algorithm is O(threads * resume elements), but resume elements |
| 4495 | is small (and will remain small at least until GDB supports thread |
| 4496 | suspension). */ |
| 4497 | |
| 4498 | static void |
| 4499 | linux_set_resume_request (thread_info *thread, thread_resume *resume, size_t n) |
| 4500 | { |
| 4501 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 4502 | |
| 4503 | for (int ndx = 0; ndx < n; ndx++) |
| 4504 | { |
| 4505 | ptid_t ptid = resume[ndx].thread; |
| 4506 | if (ptid == minus_one_ptid |
| 4507 | || ptid == thread->id |
| 4508 | /* Handle both 'pPID' and 'pPID.-1' as meaning 'all threads |
| 4509 | of PID'. */ |
| 4510 | || (ptid.pid () == pid_of (thread) |
| 4511 | && (ptid.is_pid () |
| 4512 | || ptid.lwp () == -1))) |
| 4513 | { |
| 4514 | if (resume[ndx].kind == resume_stop |
| 4515 | && thread->last_resume_kind == resume_stop) |
| 4516 | { |
| 4517 | if (debug_threads) |
| 4518 | debug_printf ("already %s LWP %ld at GDB's request\n", |
| 4519 | (thread->last_status.kind |
| 4520 | == TARGET_WAITKIND_STOPPED) |
| 4521 | ? "stopped" |
| 4522 | : "stopping", |
| 4523 | lwpid_of (thread)); |
| 4524 | |
| 4525 | continue; |
| 4526 | } |
| 4527 | |
| 4528 | /* Ignore (wildcard) resume requests for already-resumed |
| 4529 | threads. */ |
| 4530 | if (resume[ndx].kind != resume_stop |
| 4531 | && thread->last_resume_kind != resume_stop) |
| 4532 | { |
| 4533 | if (debug_threads) |
| 4534 | debug_printf ("already %s LWP %ld at GDB's request\n", |
| 4535 | (thread->last_resume_kind |
| 4536 | == resume_step) |
| 4537 | ? "stepping" |
| 4538 | : "continuing", |
| 4539 | lwpid_of (thread)); |
| 4540 | continue; |
| 4541 | } |
| 4542 | |
| 4543 | /* Don't let wildcard resumes resume fork children that GDB |
| 4544 | does not yet know are new fork children. */ |
| 4545 | if (lwp->fork_relative != NULL) |
| 4546 | { |
| 4547 | struct lwp_info *rel = lwp->fork_relative; |
| 4548 | |
| 4549 | if (rel->status_pending_p |
| 4550 | && (rel->waitstatus.kind == TARGET_WAITKIND_FORKED |
| 4551 | || rel->waitstatus.kind == TARGET_WAITKIND_VFORKED)) |
| 4552 | { |
| 4553 | if (debug_threads) |
| 4554 | debug_printf ("not resuming LWP %ld: has queued stop reply\n", |
| 4555 | lwpid_of (thread)); |
| 4556 | continue; |
| 4557 | } |
| 4558 | } |
| 4559 | |
| 4560 | /* If the thread has a pending event that has already been |
| 4561 | reported to GDBserver core, but GDB has not pulled the |
| 4562 | event out of the vStopped queue yet, likewise, ignore the |
| 4563 | (wildcard) resume request. */ |
| 4564 | if (in_queued_stop_replies (thread->id)) |
| 4565 | { |
| 4566 | if (debug_threads) |
| 4567 | debug_printf ("not resuming LWP %ld: has queued stop reply\n", |
| 4568 | lwpid_of (thread)); |
| 4569 | continue; |
| 4570 | } |
| 4571 | |
| 4572 | lwp->resume = &resume[ndx]; |
| 4573 | thread->last_resume_kind = lwp->resume->kind; |
| 4574 | |
| 4575 | lwp->step_range_start = lwp->resume->step_range_start; |
| 4576 | lwp->step_range_end = lwp->resume->step_range_end; |
| 4577 | |
| 4578 | /* If we had a deferred signal to report, dequeue one now. |
| 4579 | This can happen if LWP gets more than one signal while |
| 4580 | trying to get out of a jump pad. */ |
| 4581 | if (lwp->stopped |
| 4582 | && !lwp->status_pending_p |
| 4583 | && dequeue_one_deferred_signal (lwp, &lwp->status_pending)) |
| 4584 | { |
| 4585 | lwp->status_pending_p = 1; |
| 4586 | |
| 4587 | if (debug_threads) |
| 4588 | debug_printf ("Dequeueing deferred signal %d for LWP %ld, " |
| 4589 | "leaving status pending.\n", |
| 4590 | WSTOPSIG (lwp->status_pending), |
| 4591 | lwpid_of (thread)); |
| 4592 | } |
| 4593 | |
| 4594 | return; |
| 4595 | } |
| 4596 | } |
| 4597 | |
| 4598 | /* No resume action for this thread. */ |
| 4599 | lwp->resume = NULL; |
| 4600 | } |
| 4601 | |
| 4602 | /* find_thread callback for linux_resume. Return true if this lwp has an |
| 4603 | interesting status pending. */ |
| 4604 | |
| 4605 | static bool |
| 4606 | resume_status_pending_p (thread_info *thread) |
| 4607 | { |
| 4608 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 4609 | |
| 4610 | /* LWPs which will not be resumed are not interesting, because |
| 4611 | we might not wait for them next time through linux_wait. */ |
| 4612 | if (lwp->resume == NULL) |
| 4613 | return false; |
| 4614 | |
| 4615 | return thread_still_has_status_pending_p (thread); |
| 4616 | } |
| 4617 | |
| 4618 | /* Return 1 if this lwp that GDB wants running is stopped at an |
| 4619 | internal breakpoint that we need to step over. It assumes that any |
| 4620 | required STOP_PC adjustment has already been propagated to the |
| 4621 | inferior's regcache. */ |
| 4622 | |
| 4623 | static bool |
| 4624 | need_step_over_p (thread_info *thread) |
| 4625 | { |
| 4626 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 4627 | struct thread_info *saved_thread; |
| 4628 | CORE_ADDR pc; |
| 4629 | struct process_info *proc = get_thread_process (thread); |
| 4630 | |
| 4631 | /* GDBserver is skipping the extra traps from the wrapper program, |
| 4632 | don't have to do step over. */ |
| 4633 | if (proc->tdesc == NULL) |
| 4634 | return false; |
| 4635 | |
| 4636 | /* LWPs which will not be resumed are not interesting, because we |
| 4637 | might not wait for them next time through linux_wait. */ |
| 4638 | |
| 4639 | if (!lwp->stopped) |
| 4640 | { |
| 4641 | if (debug_threads) |
| 4642 | debug_printf ("Need step over [LWP %ld]? Ignoring, not stopped\n", |
| 4643 | lwpid_of (thread)); |
| 4644 | return false; |
| 4645 | } |
| 4646 | |
| 4647 | if (thread->last_resume_kind == resume_stop) |
| 4648 | { |
| 4649 | if (debug_threads) |
| 4650 | debug_printf ("Need step over [LWP %ld]? Ignoring, should remain" |
| 4651 | " stopped\n", |
| 4652 | lwpid_of (thread)); |
| 4653 | return false; |
| 4654 | } |
| 4655 | |
| 4656 | gdb_assert (lwp->suspended >= 0); |
| 4657 | |
| 4658 | if (lwp->suspended) |
| 4659 | { |
| 4660 | if (debug_threads) |
| 4661 | debug_printf ("Need step over [LWP %ld]? Ignoring, suspended\n", |
| 4662 | lwpid_of (thread)); |
| 4663 | return false; |
| 4664 | } |
| 4665 | |
| 4666 | if (lwp->status_pending_p) |
| 4667 | { |
| 4668 | if (debug_threads) |
| 4669 | debug_printf ("Need step over [LWP %ld]? Ignoring, has pending" |
| 4670 | " status.\n", |
| 4671 | lwpid_of (thread)); |
| 4672 | return false; |
| 4673 | } |
| 4674 | |
| 4675 | /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already, |
| 4676 | or we have. */ |
| 4677 | pc = get_pc (lwp); |
| 4678 | |
| 4679 | /* If the PC has changed since we stopped, then don't do anything, |
| 4680 | and let the breakpoint/tracepoint be hit. This happens if, for |
| 4681 | instance, GDB handled the decr_pc_after_break subtraction itself, |
| 4682 | GDB is OOL stepping this thread, or the user has issued a "jump" |
| 4683 | command, or poked thread's registers herself. */ |
| 4684 | if (pc != lwp->stop_pc) |
| 4685 | { |
| 4686 | if (debug_threads) |
| 4687 | debug_printf ("Need step over [LWP %ld]? Cancelling, PC was changed. " |
| 4688 | "Old stop_pc was 0x%s, PC is now 0x%s\n", |
| 4689 | lwpid_of (thread), |
| 4690 | paddress (lwp->stop_pc), paddress (pc)); |
| 4691 | return false; |
| 4692 | } |
| 4693 | |
| 4694 | /* On software single step target, resume the inferior with signal |
| 4695 | rather than stepping over. */ |
| 4696 | if (can_software_single_step () |
| 4697 | && lwp->pending_signals != NULL |
| 4698 | && lwp_signal_can_be_delivered (lwp)) |
| 4699 | { |
| 4700 | if (debug_threads) |
| 4701 | debug_printf ("Need step over [LWP %ld]? Ignoring, has pending" |
| 4702 | " signals.\n", |
| 4703 | lwpid_of (thread)); |
| 4704 | |
| 4705 | return false; |
| 4706 | } |
| 4707 | |
| 4708 | saved_thread = current_thread; |
| 4709 | current_thread = thread; |
| 4710 | |
| 4711 | /* We can only step over breakpoints we know about. */ |
| 4712 | if (breakpoint_here (pc) || fast_tracepoint_jump_here (pc)) |
| 4713 | { |
| 4714 | /* Don't step over a breakpoint that GDB expects to hit |
| 4715 | though. If the condition is being evaluated on the target's side |
| 4716 | and it evaluate to false, step over this breakpoint as well. */ |
| 4717 | if (gdb_breakpoint_here (pc) |
| 4718 | && gdb_condition_true_at_breakpoint (pc) |
| 4719 | && gdb_no_commands_at_breakpoint (pc)) |
| 4720 | { |
| 4721 | if (debug_threads) |
| 4722 | debug_printf ("Need step over [LWP %ld]? yes, but found" |
| 4723 | " GDB breakpoint at 0x%s; skipping step over\n", |
| 4724 | lwpid_of (thread), paddress (pc)); |
| 4725 | |
| 4726 | current_thread = saved_thread; |
| 4727 | return false; |
| 4728 | } |
| 4729 | else |
| 4730 | { |
| 4731 | if (debug_threads) |
| 4732 | debug_printf ("Need step over [LWP %ld]? yes, " |
| 4733 | "found breakpoint at 0x%s\n", |
| 4734 | lwpid_of (thread), paddress (pc)); |
| 4735 | |
| 4736 | /* We've found an lwp that needs stepping over --- return 1 so |
| 4737 | that find_thread stops looking. */ |
| 4738 | current_thread = saved_thread; |
| 4739 | |
| 4740 | return true; |
| 4741 | } |
| 4742 | } |
| 4743 | |
| 4744 | current_thread = saved_thread; |
| 4745 | |
| 4746 | if (debug_threads) |
| 4747 | debug_printf ("Need step over [LWP %ld]? No, no breakpoint found" |
| 4748 | " at 0x%s\n", |
| 4749 | lwpid_of (thread), paddress (pc)); |
| 4750 | |
| 4751 | return false; |
| 4752 | } |
| 4753 | |
| 4754 | /* Start a step-over operation on LWP. When LWP stopped at a |
| 4755 | breakpoint, to make progress, we need to remove the breakpoint out |
| 4756 | of the way. If we let other threads run while we do that, they may |
| 4757 | pass by the breakpoint location and miss hitting it. To avoid |
| 4758 | that, a step-over momentarily stops all threads while LWP is |
| 4759 | single-stepped by either hardware or software while the breakpoint |
| 4760 | is temporarily uninserted from the inferior. When the single-step |
| 4761 | finishes, we reinsert the breakpoint, and let all threads that are |
| 4762 | supposed to be running, run again. */ |
| 4763 | |
| 4764 | static int |
| 4765 | start_step_over (struct lwp_info *lwp) |
| 4766 | { |
| 4767 | struct thread_info *thread = get_lwp_thread (lwp); |
| 4768 | struct thread_info *saved_thread; |
| 4769 | CORE_ADDR pc; |
| 4770 | int step; |
| 4771 | |
| 4772 | if (debug_threads) |
| 4773 | debug_printf ("Starting step-over on LWP %ld. Stopping all threads\n", |
| 4774 | lwpid_of (thread)); |
| 4775 | |
| 4776 | stop_all_lwps (1, lwp); |
| 4777 | |
| 4778 | if (lwp->suspended != 0) |
| 4779 | { |
| 4780 | internal_error (__FILE__, __LINE__, |
| 4781 | "LWP %ld suspended=%d\n", lwpid_of (thread), |
| 4782 | lwp->suspended); |
| 4783 | } |
| 4784 | |
| 4785 | if (debug_threads) |
| 4786 | debug_printf ("Done stopping all threads for step-over.\n"); |
| 4787 | |
| 4788 | /* Note, we should always reach here with an already adjusted PC, |
| 4789 | either by GDB (if we're resuming due to GDB's request), or by our |
| 4790 | caller, if we just finished handling an internal breakpoint GDB |
| 4791 | shouldn't care about. */ |
| 4792 | pc = get_pc (lwp); |
| 4793 | |
| 4794 | saved_thread = current_thread; |
| 4795 | current_thread = thread; |
| 4796 | |
| 4797 | lwp->bp_reinsert = pc; |
| 4798 | uninsert_breakpoints_at (pc); |
| 4799 | uninsert_fast_tracepoint_jumps_at (pc); |
| 4800 | |
| 4801 | step = single_step (lwp); |
| 4802 | |
| 4803 | current_thread = saved_thread; |
| 4804 | |
| 4805 | linux_resume_one_lwp (lwp, step, 0, NULL); |
| 4806 | |
| 4807 | /* Require next event from this LWP. */ |
| 4808 | step_over_bkpt = thread->id; |
| 4809 | return 1; |
| 4810 | } |
| 4811 | |
| 4812 | /* Finish a step-over. Reinsert the breakpoint we had uninserted in |
| 4813 | start_step_over, if still there, and delete any single-step |
| 4814 | breakpoints we've set, on non hardware single-step targets. */ |
| 4815 | |
| 4816 | static int |
| 4817 | finish_step_over (struct lwp_info *lwp) |
| 4818 | { |
| 4819 | if (lwp->bp_reinsert != 0) |
| 4820 | { |
| 4821 | struct thread_info *saved_thread = current_thread; |
| 4822 | |
| 4823 | if (debug_threads) |
| 4824 | debug_printf ("Finished step over.\n"); |
| 4825 | |
| 4826 | current_thread = get_lwp_thread (lwp); |
| 4827 | |
| 4828 | /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there |
| 4829 | may be no breakpoint to reinsert there by now. */ |
| 4830 | reinsert_breakpoints_at (lwp->bp_reinsert); |
| 4831 | reinsert_fast_tracepoint_jumps_at (lwp->bp_reinsert); |
| 4832 | |
| 4833 | lwp->bp_reinsert = 0; |
| 4834 | |
| 4835 | /* Delete any single-step breakpoints. No longer needed. We |
| 4836 | don't have to worry about other threads hitting this trap, |
| 4837 | and later not being able to explain it, because we were |
| 4838 | stepping over a breakpoint, and we hold all threads but |
| 4839 | LWP stopped while doing that. */ |
| 4840 | if (!can_hardware_single_step ()) |
| 4841 | { |
| 4842 | gdb_assert (has_single_step_breakpoints (current_thread)); |
| 4843 | delete_single_step_breakpoints (current_thread); |
| 4844 | } |
| 4845 | |
| 4846 | step_over_bkpt = null_ptid; |
| 4847 | current_thread = saved_thread; |
| 4848 | return 1; |
| 4849 | } |
| 4850 | else |
| 4851 | return 0; |
| 4852 | } |
| 4853 | |
| 4854 | /* If there's a step over in progress, wait until all threads stop |
| 4855 | (that is, until the stepping thread finishes its step), and |
| 4856 | unsuspend all lwps. The stepping thread ends with its status |
| 4857 | pending, which is processed later when we get back to processing |
| 4858 | events. */ |
| 4859 | |
| 4860 | static void |
| 4861 | complete_ongoing_step_over (void) |
| 4862 | { |
| 4863 | if (step_over_bkpt != null_ptid) |
| 4864 | { |
| 4865 | struct lwp_info *lwp; |
| 4866 | int wstat; |
| 4867 | int ret; |
| 4868 | |
| 4869 | if (debug_threads) |
| 4870 | debug_printf ("detach: step over in progress, finish it first\n"); |
| 4871 | |
| 4872 | /* Passing NULL_PTID as filter indicates we want all events to |
| 4873 | be left pending. Eventually this returns when there are no |
| 4874 | unwaited-for children left. */ |
| 4875 | ret = linux_wait_for_event_filtered (minus_one_ptid, null_ptid, |
| 4876 | &wstat, __WALL); |
| 4877 | gdb_assert (ret == -1); |
| 4878 | |
| 4879 | lwp = find_lwp_pid (step_over_bkpt); |
| 4880 | if (lwp != NULL) |
| 4881 | finish_step_over (lwp); |
| 4882 | step_over_bkpt = null_ptid; |
| 4883 | unsuspend_all_lwps (lwp); |
| 4884 | } |
| 4885 | } |
| 4886 | |
| 4887 | /* This function is called once per thread. We check the thread's resume |
| 4888 | request, which will tell us whether to resume, step, or leave the thread |
| 4889 | stopped; and what signal, if any, it should be sent. |
| 4890 | |
| 4891 | For threads which we aren't explicitly told otherwise, we preserve |
| 4892 | the stepping flag; this is used for stepping over gdbserver-placed |
| 4893 | breakpoints. |
| 4894 | |
| 4895 | If pending_flags was set in any thread, we queue any needed |
| 4896 | signals, since we won't actually resume. We already have a pending |
| 4897 | event to report, so we don't need to preserve any step requests; |
| 4898 | they should be re-issued if necessary. */ |
| 4899 | |
| 4900 | static void |
| 4901 | linux_resume_one_thread (thread_info *thread, bool leave_all_stopped) |
| 4902 | { |
| 4903 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 4904 | int leave_pending; |
| 4905 | |
| 4906 | if (lwp->resume == NULL) |
| 4907 | return; |
| 4908 | |
| 4909 | if (lwp->resume->kind == resume_stop) |
| 4910 | { |
| 4911 | if (debug_threads) |
| 4912 | debug_printf ("resume_stop request for LWP %ld\n", lwpid_of (thread)); |
| 4913 | |
| 4914 | if (!lwp->stopped) |
| 4915 | { |
| 4916 | if (debug_threads) |
| 4917 | debug_printf ("stopping LWP %ld\n", lwpid_of (thread)); |
| 4918 | |
| 4919 | /* Stop the thread, and wait for the event asynchronously, |
| 4920 | through the event loop. */ |
| 4921 | send_sigstop (lwp); |
| 4922 | } |
| 4923 | else |
| 4924 | { |
| 4925 | if (debug_threads) |
| 4926 | debug_printf ("already stopped LWP %ld\n", |
| 4927 | lwpid_of (thread)); |
| 4928 | |
| 4929 | /* The LWP may have been stopped in an internal event that |
| 4930 | was not meant to be notified back to GDB (e.g., gdbserver |
| 4931 | breakpoint), so we should be reporting a stop event in |
| 4932 | this case too. */ |
| 4933 | |
| 4934 | /* If the thread already has a pending SIGSTOP, this is a |
| 4935 | no-op. Otherwise, something later will presumably resume |
| 4936 | the thread and this will cause it to cancel any pending |
| 4937 | operation, due to last_resume_kind == resume_stop. If |
| 4938 | the thread already has a pending status to report, we |
| 4939 | will still report it the next time we wait - see |
| 4940 | status_pending_p_callback. */ |
| 4941 | |
| 4942 | /* If we already have a pending signal to report, then |
| 4943 | there's no need to queue a SIGSTOP, as this means we're |
| 4944 | midway through moving the LWP out of the jumppad, and we |
| 4945 | will report the pending signal as soon as that is |
| 4946 | finished. */ |
| 4947 | if (lwp->pending_signals_to_report == NULL) |
| 4948 | send_sigstop (lwp); |
| 4949 | } |
| 4950 | |
| 4951 | /* For stop requests, we're done. */ |
| 4952 | lwp->resume = NULL; |
| 4953 | thread->last_status.kind = TARGET_WAITKIND_IGNORE; |
| 4954 | return; |
| 4955 | } |
| 4956 | |
| 4957 | /* If this thread which is about to be resumed has a pending status, |
| 4958 | then don't resume it - we can just report the pending status. |
| 4959 | Likewise if it is suspended, because e.g., another thread is |
| 4960 | stepping past a breakpoint. Make sure to queue any signals that |
| 4961 | would otherwise be sent. In all-stop mode, we do this decision |
| 4962 | based on if *any* thread has a pending status. If there's a |
| 4963 | thread that needs the step-over-breakpoint dance, then don't |
| 4964 | resume any other thread but that particular one. */ |
| 4965 | leave_pending = (lwp->suspended |
| 4966 | || lwp->status_pending_p |
| 4967 | || leave_all_stopped); |
| 4968 | |
| 4969 | /* If we have a new signal, enqueue the signal. */ |
| 4970 | if (lwp->resume->sig != 0) |
| 4971 | { |
| 4972 | siginfo_t info, *info_p; |
| 4973 | |
| 4974 | /* If this is the same signal we were previously stopped by, |
| 4975 | make sure to queue its siginfo. */ |
| 4976 | if (WIFSTOPPED (lwp->last_status) |
| 4977 | && WSTOPSIG (lwp->last_status) == lwp->resume->sig |
| 4978 | && ptrace (PTRACE_GETSIGINFO, lwpid_of (thread), |
| 4979 | (PTRACE_TYPE_ARG3) 0, &info) == 0) |
| 4980 | info_p = &info; |
| 4981 | else |
| 4982 | info_p = NULL; |
| 4983 | |
| 4984 | enqueue_pending_signal (lwp, lwp->resume->sig, info_p); |
| 4985 | } |
| 4986 | |
| 4987 | if (!leave_pending) |
| 4988 | { |
| 4989 | if (debug_threads) |
| 4990 | debug_printf ("resuming LWP %ld\n", lwpid_of (thread)); |
| 4991 | |
| 4992 | proceed_one_lwp (thread, NULL); |
| 4993 | } |
| 4994 | else |
| 4995 | { |
| 4996 | if (debug_threads) |
| 4997 | debug_printf ("leaving LWP %ld stopped\n", lwpid_of (thread)); |
| 4998 | } |
| 4999 | |
| 5000 | thread->last_status.kind = TARGET_WAITKIND_IGNORE; |
| 5001 | lwp->resume = NULL; |
| 5002 | } |
| 5003 | |
| 5004 | static void |
| 5005 | linux_resume (struct thread_resume *resume_info, size_t n) |
| 5006 | { |
| 5007 | struct thread_info *need_step_over = NULL; |
| 5008 | |
| 5009 | if (debug_threads) |
| 5010 | { |
| 5011 | debug_enter (); |
| 5012 | debug_printf ("linux_resume:\n"); |
| 5013 | } |
| 5014 | |
| 5015 | for_each_thread ([&] (thread_info *thread) |
| 5016 | { |
| 5017 | linux_set_resume_request (thread, resume_info, n); |
| 5018 | }); |
| 5019 | |
| 5020 | /* If there is a thread which would otherwise be resumed, which has |
| 5021 | a pending status, then don't resume any threads - we can just |
| 5022 | report the pending status. Make sure to queue any signals that |
| 5023 | would otherwise be sent. In non-stop mode, we'll apply this |
| 5024 | logic to each thread individually. We consume all pending events |
| 5025 | before considering to start a step-over (in all-stop). */ |
| 5026 | bool any_pending = false; |
| 5027 | if (!non_stop) |
| 5028 | any_pending = find_thread (resume_status_pending_p) != NULL; |
| 5029 | |
| 5030 | /* If there is a thread which would otherwise be resumed, which is |
| 5031 | stopped at a breakpoint that needs stepping over, then don't |
| 5032 | resume any threads - have it step over the breakpoint with all |
| 5033 | other threads stopped, then resume all threads again. Make sure |
| 5034 | to queue any signals that would otherwise be delivered or |
| 5035 | queued. */ |
| 5036 | if (!any_pending && supports_breakpoints ()) |
| 5037 | need_step_over = find_thread (need_step_over_p); |
| 5038 | |
| 5039 | bool leave_all_stopped = (need_step_over != NULL || any_pending); |
| 5040 | |
| 5041 | if (debug_threads) |
| 5042 | { |
| 5043 | if (need_step_over != NULL) |
| 5044 | debug_printf ("Not resuming all, need step over\n"); |
| 5045 | else if (any_pending) |
| 5046 | debug_printf ("Not resuming, all-stop and found " |
| 5047 | "an LWP with pending status\n"); |
| 5048 | else |
| 5049 | debug_printf ("Resuming, no pending status or step over needed\n"); |
| 5050 | } |
| 5051 | |
| 5052 | /* Even if we're leaving threads stopped, queue all signals we'd |
| 5053 | otherwise deliver. */ |
| 5054 | for_each_thread ([&] (thread_info *thread) |
| 5055 | { |
| 5056 | linux_resume_one_thread (thread, leave_all_stopped); |
| 5057 | }); |
| 5058 | |
| 5059 | if (need_step_over) |
| 5060 | start_step_over (get_thread_lwp (need_step_over)); |
| 5061 | |
| 5062 | if (debug_threads) |
| 5063 | { |
| 5064 | debug_printf ("linux_resume done\n"); |
| 5065 | debug_exit (); |
| 5066 | } |
| 5067 | |
| 5068 | /* We may have events that were pending that can/should be sent to |
| 5069 | the client now. Trigger a linux_wait call. */ |
| 5070 | if (target_is_async_p ()) |
| 5071 | async_file_mark (); |
| 5072 | } |
| 5073 | |
| 5074 | /* This function is called once per thread. We check the thread's |
| 5075 | last resume request, which will tell us whether to resume, step, or |
| 5076 | leave the thread stopped. Any signal the client requested to be |
| 5077 | delivered has already been enqueued at this point. |
| 5078 | |
| 5079 | If any thread that GDB wants running is stopped at an internal |
| 5080 | breakpoint that needs stepping over, we start a step-over operation |
| 5081 | on that particular thread, and leave all others stopped. */ |
| 5082 | |
| 5083 | static void |
| 5084 | proceed_one_lwp (thread_info *thread, lwp_info *except) |
| 5085 | { |
| 5086 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 5087 | int step; |
| 5088 | |
| 5089 | if (lwp == except) |
| 5090 | return; |
| 5091 | |
| 5092 | if (debug_threads) |
| 5093 | debug_printf ("proceed_one_lwp: lwp %ld\n", lwpid_of (thread)); |
| 5094 | |
| 5095 | if (!lwp->stopped) |
| 5096 | { |
| 5097 | if (debug_threads) |
| 5098 | debug_printf (" LWP %ld already running\n", lwpid_of (thread)); |
| 5099 | return; |
| 5100 | } |
| 5101 | |
| 5102 | if (thread->last_resume_kind == resume_stop |
| 5103 | && thread->last_status.kind != TARGET_WAITKIND_IGNORE) |
| 5104 | { |
| 5105 | if (debug_threads) |
| 5106 | debug_printf (" client wants LWP to remain %ld stopped\n", |
| 5107 | lwpid_of (thread)); |
| 5108 | return; |
| 5109 | } |
| 5110 | |
| 5111 | if (lwp->status_pending_p) |
| 5112 | { |
| 5113 | if (debug_threads) |
| 5114 | debug_printf (" LWP %ld has pending status, leaving stopped\n", |
| 5115 | lwpid_of (thread)); |
| 5116 | return; |
| 5117 | } |
| 5118 | |
| 5119 | gdb_assert (lwp->suspended >= 0); |
| 5120 | |
| 5121 | if (lwp->suspended) |
| 5122 | { |
| 5123 | if (debug_threads) |
| 5124 | debug_printf (" LWP %ld is suspended\n", lwpid_of (thread)); |
| 5125 | return; |
| 5126 | } |
| 5127 | |
| 5128 | if (thread->last_resume_kind == resume_stop |
| 5129 | && lwp->pending_signals_to_report == NULL |
| 5130 | && (lwp->collecting_fast_tracepoint |
| 5131 | == fast_tpoint_collect_result::not_collecting)) |
| 5132 | { |
| 5133 | /* We haven't reported this LWP as stopped yet (otherwise, the |
| 5134 | last_status.kind check above would catch it, and we wouldn't |
| 5135 | reach here. This LWP may have been momentarily paused by a |
| 5136 | stop_all_lwps call while handling for example, another LWP's |
| 5137 | step-over. In that case, the pending expected SIGSTOP signal |
| 5138 | that was queued at vCont;t handling time will have already |
| 5139 | been consumed by wait_for_sigstop, and so we need to requeue |
| 5140 | another one here. Note that if the LWP already has a SIGSTOP |
| 5141 | pending, this is a no-op. */ |
| 5142 | |
| 5143 | if (debug_threads) |
| 5144 | debug_printf ("Client wants LWP %ld to stop. " |
| 5145 | "Making sure it has a SIGSTOP pending\n", |
| 5146 | lwpid_of (thread)); |
| 5147 | |
| 5148 | send_sigstop (lwp); |
| 5149 | } |
| 5150 | |
| 5151 | if (thread->last_resume_kind == resume_step) |
| 5152 | { |
| 5153 | if (debug_threads) |
| 5154 | debug_printf (" stepping LWP %ld, client wants it stepping\n", |
| 5155 | lwpid_of (thread)); |
| 5156 | |
| 5157 | /* If resume_step is requested by GDB, install single-step |
| 5158 | breakpoints when the thread is about to be actually resumed if |
| 5159 | the single-step breakpoints weren't removed. */ |
| 5160 | if (can_software_single_step () |
| 5161 | && !has_single_step_breakpoints (thread)) |
| 5162 | install_software_single_step_breakpoints (lwp); |
| 5163 | |
| 5164 | step = maybe_hw_step (thread); |
| 5165 | } |
| 5166 | else if (lwp->bp_reinsert != 0) |
| 5167 | { |
| 5168 | if (debug_threads) |
| 5169 | debug_printf (" stepping LWP %ld, reinsert set\n", |
| 5170 | lwpid_of (thread)); |
| 5171 | |
| 5172 | step = maybe_hw_step (thread); |
| 5173 | } |
| 5174 | else |
| 5175 | step = 0; |
| 5176 | |
| 5177 | linux_resume_one_lwp (lwp, step, 0, NULL); |
| 5178 | } |
| 5179 | |
| 5180 | static void |
| 5181 | unsuspend_and_proceed_one_lwp (thread_info *thread, lwp_info *except) |
| 5182 | { |
| 5183 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 5184 | |
| 5185 | if (lwp == except) |
| 5186 | return; |
| 5187 | |
| 5188 | lwp_suspended_decr (lwp); |
| 5189 | |
| 5190 | proceed_one_lwp (thread, except); |
| 5191 | } |
| 5192 | |
| 5193 | /* When we finish a step-over, set threads running again. If there's |
| 5194 | another thread that may need a step-over, now's the time to start |
| 5195 | it. Eventually, we'll move all threads past their breakpoints. */ |
| 5196 | |
| 5197 | static void |
| 5198 | proceed_all_lwps (void) |
| 5199 | { |
| 5200 | struct thread_info *need_step_over; |
| 5201 | |
| 5202 | /* If there is a thread which would otherwise be resumed, which is |
| 5203 | stopped at a breakpoint that needs stepping over, then don't |
| 5204 | resume any threads - have it step over the breakpoint with all |
| 5205 | other threads stopped, then resume all threads again. */ |
| 5206 | |
| 5207 | if (supports_breakpoints ()) |
| 5208 | { |
| 5209 | need_step_over = find_thread (need_step_over_p); |
| 5210 | |
| 5211 | if (need_step_over != NULL) |
| 5212 | { |
| 5213 | if (debug_threads) |
| 5214 | debug_printf ("proceed_all_lwps: found " |
| 5215 | "thread %ld needing a step-over\n", |
| 5216 | lwpid_of (need_step_over)); |
| 5217 | |
| 5218 | start_step_over (get_thread_lwp (need_step_over)); |
| 5219 | return; |
| 5220 | } |
| 5221 | } |
| 5222 | |
| 5223 | if (debug_threads) |
| 5224 | debug_printf ("Proceeding, no step-over needed\n"); |
| 5225 | |
| 5226 | for_each_thread ([] (thread_info *thread) |
| 5227 | { |
| 5228 | proceed_one_lwp (thread, NULL); |
| 5229 | }); |
| 5230 | } |
| 5231 | |
| 5232 | /* Stopped LWPs that the client wanted to be running, that don't have |
| 5233 | pending statuses, are set to run again, except for EXCEPT, if not |
| 5234 | NULL. This undoes a stop_all_lwps call. */ |
| 5235 | |
| 5236 | static void |
| 5237 | unstop_all_lwps (int unsuspend, struct lwp_info *except) |
| 5238 | { |
| 5239 | if (debug_threads) |
| 5240 | { |
| 5241 | debug_enter (); |
| 5242 | if (except) |
| 5243 | debug_printf ("unstopping all lwps, except=(LWP %ld)\n", |
| 5244 | lwpid_of (get_lwp_thread (except))); |
| 5245 | else |
| 5246 | debug_printf ("unstopping all lwps\n"); |
| 5247 | } |
| 5248 | |
| 5249 | if (unsuspend) |
| 5250 | for_each_thread ([&] (thread_info *thread) |
| 5251 | { |
| 5252 | unsuspend_and_proceed_one_lwp (thread, except); |
| 5253 | }); |
| 5254 | else |
| 5255 | for_each_thread ([&] (thread_info *thread) |
| 5256 | { |
| 5257 | proceed_one_lwp (thread, except); |
| 5258 | }); |
| 5259 | |
| 5260 | if (debug_threads) |
| 5261 | { |
| 5262 | debug_printf ("unstop_all_lwps done\n"); |
| 5263 | debug_exit (); |
| 5264 | } |
| 5265 | } |
| 5266 | |
| 5267 | |
| 5268 | #ifdef HAVE_LINUX_REGSETS |
| 5269 | |
| 5270 | #define use_linux_regsets 1 |
| 5271 | |
| 5272 | /* Returns true if REGSET has been disabled. */ |
| 5273 | |
| 5274 | static int |
| 5275 | regset_disabled (struct regsets_info *info, struct regset_info *regset) |
| 5276 | { |
| 5277 | return (info->disabled_regsets != NULL |
| 5278 | && info->disabled_regsets[regset - info->regsets]); |
| 5279 | } |
| 5280 | |
| 5281 | /* Disable REGSET. */ |
| 5282 | |
| 5283 | static void |
| 5284 | disable_regset (struct regsets_info *info, struct regset_info *regset) |
| 5285 | { |
| 5286 | int dr_offset; |
| 5287 | |
| 5288 | dr_offset = regset - info->regsets; |
| 5289 | if (info->disabled_regsets == NULL) |
| 5290 | info->disabled_regsets = (char *) xcalloc (1, info->num_regsets); |
| 5291 | info->disabled_regsets[dr_offset] = 1; |
| 5292 | } |
| 5293 | |
| 5294 | static int |
| 5295 | regsets_fetch_inferior_registers (struct regsets_info *regsets_info, |
| 5296 | struct regcache *regcache) |
| 5297 | { |
| 5298 | struct regset_info *regset; |
| 5299 | int saw_general_regs = 0; |
| 5300 | int pid; |
| 5301 | struct iovec iov; |
| 5302 | |
| 5303 | pid = lwpid_of (current_thread); |
| 5304 | for (regset = regsets_info->regsets; regset->size >= 0; regset++) |
| 5305 | { |
| 5306 | void *buf, *data; |
| 5307 | int nt_type, res; |
| 5308 | |
| 5309 | if (regset->size == 0 || regset_disabled (regsets_info, regset)) |
| 5310 | continue; |
| 5311 | |
| 5312 | buf = xmalloc (regset->size); |
| 5313 | |
| 5314 | nt_type = regset->nt_type; |
| 5315 | if (nt_type) |
| 5316 | { |
| 5317 | iov.iov_base = buf; |
| 5318 | iov.iov_len = regset->size; |
| 5319 | data = (void *) &iov; |
| 5320 | } |
| 5321 | else |
| 5322 | data = buf; |
| 5323 | |
| 5324 | #ifndef __sparc__ |
| 5325 | res = ptrace (regset->get_request, pid, |
| 5326 | (PTRACE_TYPE_ARG3) (long) nt_type, data); |
| 5327 | #else |
| 5328 | res = ptrace (regset->get_request, pid, data, nt_type); |
| 5329 | #endif |
| 5330 | if (res < 0) |
| 5331 | { |
| 5332 | if (errno == EIO |
| 5333 | || (errno == EINVAL && regset->type == OPTIONAL_REGS)) |
| 5334 | { |
| 5335 | /* If we get EIO on a regset, or an EINVAL and the regset is |
| 5336 | optional, do not try it again for this process mode. */ |
| 5337 | disable_regset (regsets_info, regset); |
| 5338 | } |
| 5339 | else if (errno == ENODATA) |
| 5340 | { |
| 5341 | /* ENODATA may be returned if the regset is currently |
| 5342 | not "active". This can happen in normal operation, |
| 5343 | so suppress the warning in this case. */ |
| 5344 | } |
| 5345 | else if (errno == ESRCH) |
| 5346 | { |
| 5347 | /* At this point, ESRCH should mean the process is |
| 5348 | already gone, in which case we simply ignore attempts |
| 5349 | to read its registers. */ |
| 5350 | } |
| 5351 | else |
| 5352 | { |
| 5353 | char s[256]; |
| 5354 | sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d", |
| 5355 | pid); |
| 5356 | perror (s); |
| 5357 | } |
| 5358 | } |
| 5359 | else |
| 5360 | { |
| 5361 | if (regset->type == GENERAL_REGS) |
| 5362 | saw_general_regs = 1; |
| 5363 | regset->store_function (regcache, buf); |
| 5364 | } |
| 5365 | free (buf); |
| 5366 | } |
| 5367 | if (saw_general_regs) |
| 5368 | return 0; |
| 5369 | else |
| 5370 | return 1; |
| 5371 | } |
| 5372 | |
| 5373 | static int |
| 5374 | regsets_store_inferior_registers (struct regsets_info *regsets_info, |
| 5375 | struct regcache *regcache) |
| 5376 | { |
| 5377 | struct regset_info *regset; |
| 5378 | int saw_general_regs = 0; |
| 5379 | int pid; |
| 5380 | struct iovec iov; |
| 5381 | |
| 5382 | pid = lwpid_of (current_thread); |
| 5383 | for (regset = regsets_info->regsets; regset->size >= 0; regset++) |
| 5384 | { |
| 5385 | void *buf, *data; |
| 5386 | int nt_type, res; |
| 5387 | |
| 5388 | if (regset->size == 0 || regset_disabled (regsets_info, regset) |
| 5389 | || regset->fill_function == NULL) |
| 5390 | continue; |
| 5391 | |
| 5392 | buf = xmalloc (regset->size); |
| 5393 | |
| 5394 | /* First fill the buffer with the current register set contents, |
| 5395 | in case there are any items in the kernel's regset that are |
| 5396 | not in gdbserver's regcache. */ |
| 5397 | |
| 5398 | nt_type = regset->nt_type; |
| 5399 | if (nt_type) |
| 5400 | { |
| 5401 | iov.iov_base = buf; |
| 5402 | iov.iov_len = regset->size; |
| 5403 | data = (void *) &iov; |
| 5404 | } |
| 5405 | else |
| 5406 | data = buf; |
| 5407 | |
| 5408 | #ifndef __sparc__ |
| 5409 | res = ptrace (regset->get_request, pid, |
| 5410 | (PTRACE_TYPE_ARG3) (long) nt_type, data); |
| 5411 | #else |
| 5412 | res = ptrace (regset->get_request, pid, data, nt_type); |
| 5413 | #endif |
| 5414 | |
| 5415 | if (res == 0) |
| 5416 | { |
| 5417 | /* Then overlay our cached registers on that. */ |
| 5418 | regset->fill_function (regcache, buf); |
| 5419 | |
| 5420 | /* Only now do we write the register set. */ |
| 5421 | #ifndef __sparc__ |
| 5422 | res = ptrace (regset->set_request, pid, |
| 5423 | (PTRACE_TYPE_ARG3) (long) nt_type, data); |
| 5424 | #else |
| 5425 | res = ptrace (regset->set_request, pid, data, nt_type); |
| 5426 | #endif |
| 5427 | } |
| 5428 | |
| 5429 | if (res < 0) |
| 5430 | { |
| 5431 | if (errno == EIO |
| 5432 | || (errno == EINVAL && regset->type == OPTIONAL_REGS)) |
| 5433 | { |
| 5434 | /* If we get EIO on a regset, or an EINVAL and the regset is |
| 5435 | optional, do not try it again for this process mode. */ |
| 5436 | disable_regset (regsets_info, regset); |
| 5437 | } |
| 5438 | else if (errno == ESRCH) |
| 5439 | { |
| 5440 | /* At this point, ESRCH should mean the process is |
| 5441 | already gone, in which case we simply ignore attempts |
| 5442 | to change its registers. See also the related |
| 5443 | comment in linux_resume_one_lwp. */ |
| 5444 | free (buf); |
| 5445 | return 0; |
| 5446 | } |
| 5447 | else |
| 5448 | { |
| 5449 | perror ("Warning: ptrace(regsets_store_inferior_registers)"); |
| 5450 | } |
| 5451 | } |
| 5452 | else if (regset->type == GENERAL_REGS) |
| 5453 | saw_general_regs = 1; |
| 5454 | free (buf); |
| 5455 | } |
| 5456 | if (saw_general_regs) |
| 5457 | return 0; |
| 5458 | else |
| 5459 | return 1; |
| 5460 | } |
| 5461 | |
| 5462 | #else /* !HAVE_LINUX_REGSETS */ |
| 5463 | |
| 5464 | #define use_linux_regsets 0 |
| 5465 | #define regsets_fetch_inferior_registers(regsets_info, regcache) 1 |
| 5466 | #define regsets_store_inferior_registers(regsets_info, regcache) 1 |
| 5467 | |
| 5468 | #endif |
| 5469 | |
| 5470 | /* Return 1 if register REGNO is supported by one of the regset ptrace |
| 5471 | calls or 0 if it has to be transferred individually. */ |
| 5472 | |
| 5473 | static int |
| 5474 | linux_register_in_regsets (const struct regs_info *regs_info, int regno) |
| 5475 | { |
| 5476 | unsigned char mask = 1 << (regno % 8); |
| 5477 | size_t index = regno / 8; |
| 5478 | |
| 5479 | return (use_linux_regsets |
| 5480 | && (regs_info->regset_bitmap == NULL |
| 5481 | || (regs_info->regset_bitmap[index] & mask) != 0)); |
| 5482 | } |
| 5483 | |
| 5484 | #ifdef HAVE_LINUX_USRREGS |
| 5485 | |
| 5486 | static int |
| 5487 | register_addr (const struct usrregs_info *usrregs, int regnum) |
| 5488 | { |
| 5489 | int addr; |
| 5490 | |
| 5491 | if (regnum < 0 || regnum >= usrregs->num_regs) |
| 5492 | error ("Invalid register number %d.", regnum); |
| 5493 | |
| 5494 | addr = usrregs->regmap[regnum]; |
| 5495 | |
| 5496 | return addr; |
| 5497 | } |
| 5498 | |
| 5499 | /* Fetch one register. */ |
| 5500 | static void |
| 5501 | fetch_register (const struct usrregs_info *usrregs, |
| 5502 | struct regcache *regcache, int regno) |
| 5503 | { |
| 5504 | CORE_ADDR regaddr; |
| 5505 | int i, size; |
| 5506 | char *buf; |
| 5507 | int pid; |
| 5508 | |
| 5509 | if (regno >= usrregs->num_regs) |
| 5510 | return; |
| 5511 | if ((*the_low_target.cannot_fetch_register) (regno)) |
| 5512 | return; |
| 5513 | |
| 5514 | regaddr = register_addr (usrregs, regno); |
| 5515 | if (regaddr == -1) |
| 5516 | return; |
| 5517 | |
| 5518 | size = ((register_size (regcache->tdesc, regno) |
| 5519 | + sizeof (PTRACE_XFER_TYPE) - 1) |
| 5520 | & -sizeof (PTRACE_XFER_TYPE)); |
| 5521 | buf = (char *) alloca (size); |
| 5522 | |
| 5523 | pid = lwpid_of (current_thread); |
| 5524 | for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE)) |
| 5525 | { |
| 5526 | errno = 0; |
| 5527 | *(PTRACE_XFER_TYPE *) (buf + i) = |
| 5528 | ptrace (PTRACE_PEEKUSER, pid, |
| 5529 | /* Coerce to a uintptr_t first to avoid potential gcc warning |
| 5530 | of coercing an 8 byte integer to a 4 byte pointer. */ |
| 5531 | (PTRACE_TYPE_ARG3) (uintptr_t) regaddr, (PTRACE_TYPE_ARG4) 0); |
| 5532 | regaddr += sizeof (PTRACE_XFER_TYPE); |
| 5533 | if (errno != 0) |
| 5534 | { |
| 5535 | /* Mark register REGNO unavailable. */ |
| 5536 | supply_register (regcache, regno, NULL); |
| 5537 | return; |
| 5538 | } |
| 5539 | } |
| 5540 | |
| 5541 | if (the_low_target.supply_ptrace_register) |
| 5542 | the_low_target.supply_ptrace_register (regcache, regno, buf); |
| 5543 | else |
| 5544 | supply_register (regcache, regno, buf); |
| 5545 | } |
| 5546 | |
| 5547 | /* Store one register. */ |
| 5548 | static void |
| 5549 | store_register (const struct usrregs_info *usrregs, |
| 5550 | struct regcache *regcache, int regno) |
| 5551 | { |
| 5552 | CORE_ADDR regaddr; |
| 5553 | int i, size; |
| 5554 | char *buf; |
| 5555 | int pid; |
| 5556 | |
| 5557 | if (regno >= usrregs->num_regs) |
| 5558 | return; |
| 5559 | if ((*the_low_target.cannot_store_register) (regno)) |
| 5560 | return; |
| 5561 | |
| 5562 | regaddr = register_addr (usrregs, regno); |
| 5563 | if (regaddr == -1) |
| 5564 | return; |
| 5565 | |
| 5566 | size = ((register_size (regcache->tdesc, regno) |
| 5567 | + sizeof (PTRACE_XFER_TYPE) - 1) |
| 5568 | & -sizeof (PTRACE_XFER_TYPE)); |
| 5569 | buf = (char *) alloca (size); |
| 5570 | memset (buf, 0, size); |
| 5571 | |
| 5572 | if (the_low_target.collect_ptrace_register) |
| 5573 | the_low_target.collect_ptrace_register (regcache, regno, buf); |
| 5574 | else |
| 5575 | collect_register (regcache, regno, buf); |
| 5576 | |
| 5577 | pid = lwpid_of (current_thread); |
| 5578 | for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE)) |
| 5579 | { |
| 5580 | errno = 0; |
| 5581 | ptrace (PTRACE_POKEUSER, pid, |
| 5582 | /* Coerce to a uintptr_t first to avoid potential gcc warning |
| 5583 | about coercing an 8 byte integer to a 4 byte pointer. */ |
| 5584 | (PTRACE_TYPE_ARG3) (uintptr_t) regaddr, |
| 5585 | (PTRACE_TYPE_ARG4) *(PTRACE_XFER_TYPE *) (buf + i)); |
| 5586 | if (errno != 0) |
| 5587 | { |
| 5588 | /* At this point, ESRCH should mean the process is |
| 5589 | already gone, in which case we simply ignore attempts |
| 5590 | to change its registers. See also the related |
| 5591 | comment in linux_resume_one_lwp. */ |
| 5592 | if (errno == ESRCH) |
| 5593 | return; |
| 5594 | |
| 5595 | if ((*the_low_target.cannot_store_register) (regno) == 0) |
| 5596 | error ("writing register %d: %s", regno, strerror (errno)); |
| 5597 | } |
| 5598 | regaddr += sizeof (PTRACE_XFER_TYPE); |
| 5599 | } |
| 5600 | } |
| 5601 | |
| 5602 | /* Fetch all registers, or just one, from the child process. |
| 5603 | If REGNO is -1, do this for all registers, skipping any that are |
| 5604 | assumed to have been retrieved by regsets_fetch_inferior_registers, |
| 5605 | unless ALL is non-zero. |
| 5606 | Otherwise, REGNO specifies which register (so we can save time). */ |
| 5607 | static void |
| 5608 | usr_fetch_inferior_registers (const struct regs_info *regs_info, |
| 5609 | struct regcache *regcache, int regno, int all) |
| 5610 | { |
| 5611 | struct usrregs_info *usr = regs_info->usrregs; |
| 5612 | |
| 5613 | if (regno == -1) |
| 5614 | { |
| 5615 | for (regno = 0; regno < usr->num_regs; regno++) |
| 5616 | if (all || !linux_register_in_regsets (regs_info, regno)) |
| 5617 | fetch_register (usr, regcache, regno); |
| 5618 | } |
| 5619 | else |
| 5620 | fetch_register (usr, regcache, regno); |
| 5621 | } |
| 5622 | |
| 5623 | /* Store our register values back into the inferior. |
| 5624 | If REGNO is -1, do this for all registers, skipping any that are |
| 5625 | assumed to have been saved by regsets_store_inferior_registers, |
| 5626 | unless ALL is non-zero. |
| 5627 | Otherwise, REGNO specifies which register (so we can save time). */ |
| 5628 | static void |
| 5629 | usr_store_inferior_registers (const struct regs_info *regs_info, |
| 5630 | struct regcache *regcache, int regno, int all) |
| 5631 | { |
| 5632 | struct usrregs_info *usr = regs_info->usrregs; |
| 5633 | |
| 5634 | if (regno == -1) |
| 5635 | { |
| 5636 | for (regno = 0; regno < usr->num_regs; regno++) |
| 5637 | if (all || !linux_register_in_regsets (regs_info, regno)) |
| 5638 | store_register (usr, regcache, regno); |
| 5639 | } |
| 5640 | else |
| 5641 | store_register (usr, regcache, regno); |
| 5642 | } |
| 5643 | |
| 5644 | #else /* !HAVE_LINUX_USRREGS */ |
| 5645 | |
| 5646 | #define usr_fetch_inferior_registers(regs_info, regcache, regno, all) do {} while (0) |
| 5647 | #define usr_store_inferior_registers(regs_info, regcache, regno, all) do {} while (0) |
| 5648 | |
| 5649 | #endif |
| 5650 | |
| 5651 | |
| 5652 | static void |
| 5653 | linux_fetch_registers (struct regcache *regcache, int regno) |
| 5654 | { |
| 5655 | int use_regsets; |
| 5656 | int all = 0; |
| 5657 | const struct regs_info *regs_info = (*the_low_target.regs_info) (); |
| 5658 | |
| 5659 | if (regno == -1) |
| 5660 | { |
| 5661 | if (the_low_target.fetch_register != NULL |
| 5662 | && regs_info->usrregs != NULL) |
| 5663 | for (regno = 0; regno < regs_info->usrregs->num_regs; regno++) |
| 5664 | (*the_low_target.fetch_register) (regcache, regno); |
| 5665 | |
| 5666 | all = regsets_fetch_inferior_registers (regs_info->regsets_info, regcache); |
| 5667 | if (regs_info->usrregs != NULL) |
| 5668 | usr_fetch_inferior_registers (regs_info, regcache, -1, all); |
| 5669 | } |
| 5670 | else |
| 5671 | { |
| 5672 | if (the_low_target.fetch_register != NULL |
| 5673 | && (*the_low_target.fetch_register) (regcache, regno)) |
| 5674 | return; |
| 5675 | |
| 5676 | use_regsets = linux_register_in_regsets (regs_info, regno); |
| 5677 | if (use_regsets) |
| 5678 | all = regsets_fetch_inferior_registers (regs_info->regsets_info, |
| 5679 | regcache); |
| 5680 | if ((!use_regsets || all) && regs_info->usrregs != NULL) |
| 5681 | usr_fetch_inferior_registers (regs_info, regcache, regno, 1); |
| 5682 | } |
| 5683 | } |
| 5684 | |
| 5685 | static void |
| 5686 | linux_store_registers (struct regcache *regcache, int regno) |
| 5687 | { |
| 5688 | int use_regsets; |
| 5689 | int all = 0; |
| 5690 | const struct regs_info *regs_info = (*the_low_target.regs_info) (); |
| 5691 | |
| 5692 | if (regno == -1) |
| 5693 | { |
| 5694 | all = regsets_store_inferior_registers (regs_info->regsets_info, |
| 5695 | regcache); |
| 5696 | if (regs_info->usrregs != NULL) |
| 5697 | usr_store_inferior_registers (regs_info, regcache, regno, all); |
| 5698 | } |
| 5699 | else |
| 5700 | { |
| 5701 | use_regsets = linux_register_in_regsets (regs_info, regno); |
| 5702 | if (use_regsets) |
| 5703 | all = regsets_store_inferior_registers (regs_info->regsets_info, |
| 5704 | regcache); |
| 5705 | if ((!use_regsets || all) && regs_info->usrregs != NULL) |
| 5706 | usr_store_inferior_registers (regs_info, regcache, regno, 1); |
| 5707 | } |
| 5708 | } |
| 5709 | |
| 5710 | |
| 5711 | /* Copy LEN bytes from inferior's memory starting at MEMADDR |
| 5712 | to debugger memory starting at MYADDR. */ |
| 5713 | |
| 5714 | static int |
| 5715 | linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len) |
| 5716 | { |
| 5717 | int pid = lwpid_of (current_thread); |
| 5718 | PTRACE_XFER_TYPE *buffer; |
| 5719 | CORE_ADDR addr; |
| 5720 | int count; |
| 5721 | char filename[64]; |
| 5722 | int i; |
| 5723 | int ret; |
| 5724 | int fd; |
| 5725 | |
| 5726 | /* Try using /proc. Don't bother for one word. */ |
| 5727 | if (len >= 3 * sizeof (long)) |
| 5728 | { |
| 5729 | int bytes; |
| 5730 | |
| 5731 | /* We could keep this file open and cache it - possibly one per |
| 5732 | thread. That requires some juggling, but is even faster. */ |
| 5733 | sprintf (filename, "/proc/%d/mem", pid); |
| 5734 | fd = open (filename, O_RDONLY | O_LARGEFILE); |
| 5735 | if (fd == -1) |
| 5736 | goto no_proc; |
| 5737 | |
| 5738 | /* If pread64 is available, use it. It's faster if the kernel |
| 5739 | supports it (only one syscall), and it's 64-bit safe even on |
| 5740 | 32-bit platforms (for instance, SPARC debugging a SPARC64 |
| 5741 | application). */ |
| 5742 | #ifdef HAVE_PREAD64 |
| 5743 | bytes = pread64 (fd, myaddr, len, memaddr); |
| 5744 | #else |
| 5745 | bytes = -1; |
| 5746 | if (lseek (fd, memaddr, SEEK_SET) != -1) |
| 5747 | bytes = read (fd, myaddr, len); |
| 5748 | #endif |
| 5749 | |
| 5750 | close (fd); |
| 5751 | if (bytes == len) |
| 5752 | return 0; |
| 5753 | |
| 5754 | /* Some data was read, we'll try to get the rest with ptrace. */ |
| 5755 | if (bytes > 0) |
| 5756 | { |
| 5757 | memaddr += bytes; |
| 5758 | myaddr += bytes; |
| 5759 | len -= bytes; |
| 5760 | } |
| 5761 | } |
| 5762 | |
| 5763 | no_proc: |
| 5764 | /* Round starting address down to longword boundary. */ |
| 5765 | addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); |
| 5766 | /* Round ending address up; get number of longwords that makes. */ |
| 5767 | count = ((((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) |
| 5768 | / sizeof (PTRACE_XFER_TYPE)); |
| 5769 | /* Allocate buffer of that many longwords. */ |
| 5770 | buffer = XALLOCAVEC (PTRACE_XFER_TYPE, count); |
| 5771 | |
| 5772 | /* Read all the longwords */ |
| 5773 | errno = 0; |
| 5774 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) |
| 5775 | { |
| 5776 | /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning |
| 5777 | about coercing an 8 byte integer to a 4 byte pointer. */ |
| 5778 | buffer[i] = ptrace (PTRACE_PEEKTEXT, pid, |
| 5779 | (PTRACE_TYPE_ARG3) (uintptr_t) addr, |
| 5780 | (PTRACE_TYPE_ARG4) 0); |
| 5781 | if (errno) |
| 5782 | break; |
| 5783 | } |
| 5784 | ret = errno; |
| 5785 | |
| 5786 | /* Copy appropriate bytes out of the buffer. */ |
| 5787 | if (i > 0) |
| 5788 | { |
| 5789 | i *= sizeof (PTRACE_XFER_TYPE); |
| 5790 | i -= memaddr & (sizeof (PTRACE_XFER_TYPE) - 1); |
| 5791 | memcpy (myaddr, |
| 5792 | (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), |
| 5793 | i < len ? i : len); |
| 5794 | } |
| 5795 | |
| 5796 | return ret; |
| 5797 | } |
| 5798 | |
| 5799 | /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's |
| 5800 | memory at MEMADDR. On failure (cannot write to the inferior) |
| 5801 | returns the value of errno. Always succeeds if LEN is zero. */ |
| 5802 | |
| 5803 | static int |
| 5804 | linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len) |
| 5805 | { |
| 5806 | int i; |
| 5807 | /* Round starting address down to longword boundary. */ |
| 5808 | CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); |
| 5809 | /* Round ending address up; get number of longwords that makes. */ |
| 5810 | int count |
| 5811 | = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) |
| 5812 | / sizeof (PTRACE_XFER_TYPE); |
| 5813 | |
| 5814 | /* Allocate buffer of that many longwords. */ |
| 5815 | PTRACE_XFER_TYPE *buffer = XALLOCAVEC (PTRACE_XFER_TYPE, count); |
| 5816 | |
| 5817 | int pid = lwpid_of (current_thread); |
| 5818 | |
| 5819 | if (len == 0) |
| 5820 | { |
| 5821 | /* Zero length write always succeeds. */ |
| 5822 | return 0; |
| 5823 | } |
| 5824 | |
| 5825 | if (debug_threads) |
| 5826 | { |
| 5827 | /* Dump up to four bytes. */ |
| 5828 | char str[4 * 2 + 1]; |
| 5829 | char *p = str; |
| 5830 | int dump = len < 4 ? len : 4; |
| 5831 | |
| 5832 | for (i = 0; i < dump; i++) |
| 5833 | { |
| 5834 | sprintf (p, "%02x", myaddr[i]); |
| 5835 | p += 2; |
| 5836 | } |
| 5837 | *p = '\0'; |
| 5838 | |
| 5839 | debug_printf ("Writing %s to 0x%08lx in process %d\n", |
| 5840 | str, (long) memaddr, pid); |
| 5841 | } |
| 5842 | |
| 5843 | /* Fill start and end extra bytes of buffer with existing memory data. */ |
| 5844 | |
| 5845 | errno = 0; |
| 5846 | /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning |
| 5847 | about coercing an 8 byte integer to a 4 byte pointer. */ |
| 5848 | buffer[0] = ptrace (PTRACE_PEEKTEXT, pid, |
| 5849 | (PTRACE_TYPE_ARG3) (uintptr_t) addr, |
| 5850 | (PTRACE_TYPE_ARG4) 0); |
| 5851 | if (errno) |
| 5852 | return errno; |
| 5853 | |
| 5854 | if (count > 1) |
| 5855 | { |
| 5856 | errno = 0; |
| 5857 | buffer[count - 1] |
| 5858 | = ptrace (PTRACE_PEEKTEXT, pid, |
| 5859 | /* Coerce to a uintptr_t first to avoid potential gcc warning |
| 5860 | about coercing an 8 byte integer to a 4 byte pointer. */ |
| 5861 | (PTRACE_TYPE_ARG3) (uintptr_t) (addr + (count - 1) |
| 5862 | * sizeof (PTRACE_XFER_TYPE)), |
| 5863 | (PTRACE_TYPE_ARG4) 0); |
| 5864 | if (errno) |
| 5865 | return errno; |
| 5866 | } |
| 5867 | |
| 5868 | /* Copy data to be written over corresponding part of buffer. */ |
| 5869 | |
| 5870 | memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), |
| 5871 | myaddr, len); |
| 5872 | |
| 5873 | /* Write the entire buffer. */ |
| 5874 | |
| 5875 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) |
| 5876 | { |
| 5877 | errno = 0; |
| 5878 | ptrace (PTRACE_POKETEXT, pid, |
| 5879 | /* Coerce to a uintptr_t first to avoid potential gcc warning |
| 5880 | about coercing an 8 byte integer to a 4 byte pointer. */ |
| 5881 | (PTRACE_TYPE_ARG3) (uintptr_t) addr, |
| 5882 | (PTRACE_TYPE_ARG4) buffer[i]); |
| 5883 | if (errno) |
| 5884 | return errno; |
| 5885 | } |
| 5886 | |
| 5887 | return 0; |
| 5888 | } |
| 5889 | |
| 5890 | static void |
| 5891 | linux_look_up_symbols (void) |
| 5892 | { |
| 5893 | #ifdef USE_THREAD_DB |
| 5894 | struct process_info *proc = current_process (); |
| 5895 | |
| 5896 | if (proc->priv->thread_db != NULL) |
| 5897 | return; |
| 5898 | |
| 5899 | thread_db_init (); |
| 5900 | #endif |
| 5901 | } |
| 5902 | |
| 5903 | static void |
| 5904 | linux_request_interrupt (void) |
| 5905 | { |
| 5906 | /* Send a SIGINT to the process group. This acts just like the user |
| 5907 | typed a ^C on the controlling terminal. */ |
| 5908 | kill (-signal_pid, SIGINT); |
| 5909 | } |
| 5910 | |
| 5911 | /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET |
| 5912 | to debugger memory starting at MYADDR. */ |
| 5913 | |
| 5914 | static int |
| 5915 | linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len) |
| 5916 | { |
| 5917 | char filename[PATH_MAX]; |
| 5918 | int fd, n; |
| 5919 | int pid = lwpid_of (current_thread); |
| 5920 | |
| 5921 | xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid); |
| 5922 | |
| 5923 | fd = open (filename, O_RDONLY); |
| 5924 | if (fd < 0) |
| 5925 | return -1; |
| 5926 | |
| 5927 | if (offset != (CORE_ADDR) 0 |
| 5928 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) |
| 5929 | n = -1; |
| 5930 | else |
| 5931 | n = read (fd, myaddr, len); |
| 5932 | |
| 5933 | close (fd); |
| 5934 | |
| 5935 | return n; |
| 5936 | } |
| 5937 | |
| 5938 | /* These breakpoint and watchpoint related wrapper functions simply |
| 5939 | pass on the function call if the target has registered a |
| 5940 | corresponding function. */ |
| 5941 | |
| 5942 | static int |
| 5943 | linux_supports_z_point_type (char z_type) |
| 5944 | { |
| 5945 | return (the_low_target.supports_z_point_type != NULL |
| 5946 | && the_low_target.supports_z_point_type (z_type)); |
| 5947 | } |
| 5948 | |
| 5949 | static int |
| 5950 | linux_insert_point (enum raw_bkpt_type type, CORE_ADDR addr, |
| 5951 | int size, struct raw_breakpoint *bp) |
| 5952 | { |
| 5953 | if (type == raw_bkpt_type_sw) |
| 5954 | return insert_memory_breakpoint (bp); |
| 5955 | else if (the_low_target.insert_point != NULL) |
| 5956 | return the_low_target.insert_point (type, addr, size, bp); |
| 5957 | else |
| 5958 | /* Unsupported (see target.h). */ |
| 5959 | return 1; |
| 5960 | } |
| 5961 | |
| 5962 | static int |
| 5963 | linux_remove_point (enum raw_bkpt_type type, CORE_ADDR addr, |
| 5964 | int size, struct raw_breakpoint *bp) |
| 5965 | { |
| 5966 | if (type == raw_bkpt_type_sw) |
| 5967 | return remove_memory_breakpoint (bp); |
| 5968 | else if (the_low_target.remove_point != NULL) |
| 5969 | return the_low_target.remove_point (type, addr, size, bp); |
| 5970 | else |
| 5971 | /* Unsupported (see target.h). */ |
| 5972 | return 1; |
| 5973 | } |
| 5974 | |
| 5975 | /* Implement the to_stopped_by_sw_breakpoint target_ops |
| 5976 | method. */ |
| 5977 | |
| 5978 | static int |
| 5979 | linux_stopped_by_sw_breakpoint (void) |
| 5980 | { |
| 5981 | struct lwp_info *lwp = get_thread_lwp (current_thread); |
| 5982 | |
| 5983 | return (lwp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT); |
| 5984 | } |
| 5985 | |
| 5986 | /* Implement the to_supports_stopped_by_sw_breakpoint target_ops |
| 5987 | method. */ |
| 5988 | |
| 5989 | static int |
| 5990 | linux_supports_stopped_by_sw_breakpoint (void) |
| 5991 | { |
| 5992 | return USE_SIGTRAP_SIGINFO; |
| 5993 | } |
| 5994 | |
| 5995 | /* Implement the to_stopped_by_hw_breakpoint target_ops |
| 5996 | method. */ |
| 5997 | |
| 5998 | static int |
| 5999 | linux_stopped_by_hw_breakpoint (void) |
| 6000 | { |
| 6001 | struct lwp_info *lwp = get_thread_lwp (current_thread); |
| 6002 | |
| 6003 | return (lwp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT); |
| 6004 | } |
| 6005 | |
| 6006 | /* Implement the to_supports_stopped_by_hw_breakpoint target_ops |
| 6007 | method. */ |
| 6008 | |
| 6009 | static int |
| 6010 | linux_supports_stopped_by_hw_breakpoint (void) |
| 6011 | { |
| 6012 | return USE_SIGTRAP_SIGINFO; |
| 6013 | } |
| 6014 | |
| 6015 | /* Implement the supports_hardware_single_step target_ops method. */ |
| 6016 | |
| 6017 | static int |
| 6018 | linux_supports_hardware_single_step (void) |
| 6019 | { |
| 6020 | return can_hardware_single_step (); |
| 6021 | } |
| 6022 | |
| 6023 | static int |
| 6024 | linux_supports_software_single_step (void) |
| 6025 | { |
| 6026 | return can_software_single_step (); |
| 6027 | } |
| 6028 | |
| 6029 | static int |
| 6030 | linux_stopped_by_watchpoint (void) |
| 6031 | { |
| 6032 | struct lwp_info *lwp = get_thread_lwp (current_thread); |
| 6033 | |
| 6034 | return lwp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
| 6035 | } |
| 6036 | |
| 6037 | static CORE_ADDR |
| 6038 | linux_stopped_data_address (void) |
| 6039 | { |
| 6040 | struct lwp_info *lwp = get_thread_lwp (current_thread); |
| 6041 | |
| 6042 | return lwp->stopped_data_address; |
| 6043 | } |
| 6044 | |
| 6045 | #if defined(__UCLIBC__) && defined(HAS_NOMMU) \ |
| 6046 | && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \ |
| 6047 | && defined(PT_TEXT_END_ADDR) |
| 6048 | |
| 6049 | /* This is only used for targets that define PT_TEXT_ADDR, |
| 6050 | PT_DATA_ADDR and PT_TEXT_END_ADDR. If those are not defined, supposedly |
| 6051 | the target has different ways of acquiring this information, like |
| 6052 | loadmaps. */ |
| 6053 | |
| 6054 | /* Under uClinux, programs are loaded at non-zero offsets, which we need |
| 6055 | to tell gdb about. */ |
| 6056 | |
| 6057 | static int |
| 6058 | linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p) |
| 6059 | { |
| 6060 | unsigned long text, text_end, data; |
| 6061 | int pid = lwpid_of (current_thread); |
| 6062 | |
| 6063 | errno = 0; |
| 6064 | |
| 6065 | text = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_TEXT_ADDR, |
| 6066 | (PTRACE_TYPE_ARG4) 0); |
| 6067 | text_end = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_TEXT_END_ADDR, |
| 6068 | (PTRACE_TYPE_ARG4) 0); |
| 6069 | data = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_DATA_ADDR, |
| 6070 | (PTRACE_TYPE_ARG4) 0); |
| 6071 | |
| 6072 | if (errno == 0) |
| 6073 | { |
| 6074 | /* Both text and data offsets produced at compile-time (and so |
| 6075 | used by gdb) are relative to the beginning of the program, |
| 6076 | with the data segment immediately following the text segment. |
| 6077 | However, the actual runtime layout in memory may put the data |
| 6078 | somewhere else, so when we send gdb a data base-address, we |
| 6079 | use the real data base address and subtract the compile-time |
| 6080 | data base-address from it (which is just the length of the |
| 6081 | text segment). BSS immediately follows data in both |
| 6082 | cases. */ |
| 6083 | *text_p = text; |
| 6084 | *data_p = data - (text_end - text); |
| 6085 | |
| 6086 | return 1; |
| 6087 | } |
| 6088 | return 0; |
| 6089 | } |
| 6090 | #endif |
| 6091 | |
| 6092 | static int |
| 6093 | linux_qxfer_osdata (const char *annex, |
| 6094 | unsigned char *readbuf, unsigned const char *writebuf, |
| 6095 | CORE_ADDR offset, int len) |
| 6096 | { |
| 6097 | return linux_common_xfer_osdata (annex, readbuf, offset, len); |
| 6098 | } |
| 6099 | |
| 6100 | /* Convert a native/host siginfo object, into/from the siginfo in the |
| 6101 | layout of the inferiors' architecture. */ |
| 6102 | |
| 6103 | static void |
| 6104 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
| 6105 | { |
| 6106 | int done = 0; |
| 6107 | |
| 6108 | if (the_low_target.siginfo_fixup != NULL) |
| 6109 | done = the_low_target.siginfo_fixup (siginfo, inf_siginfo, direction); |
| 6110 | |
| 6111 | /* If there was no callback, or the callback didn't do anything, |
| 6112 | then just do a straight memcpy. */ |
| 6113 | if (!done) |
| 6114 | { |
| 6115 | if (direction == 1) |
| 6116 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
| 6117 | else |
| 6118 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
| 6119 | } |
| 6120 | } |
| 6121 | |
| 6122 | static int |
| 6123 | linux_xfer_siginfo (const char *annex, unsigned char *readbuf, |
| 6124 | unsigned const char *writebuf, CORE_ADDR offset, int len) |
| 6125 | { |
| 6126 | int pid; |
| 6127 | siginfo_t siginfo; |
| 6128 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; |
| 6129 | |
| 6130 | if (current_thread == NULL) |
| 6131 | return -1; |
| 6132 | |
| 6133 | pid = lwpid_of (current_thread); |
| 6134 | |
| 6135 | if (debug_threads) |
| 6136 | debug_printf ("%s siginfo for lwp %d.\n", |
| 6137 | readbuf != NULL ? "Reading" : "Writing", |
| 6138 | pid); |
| 6139 | |
| 6140 | if (offset >= sizeof (siginfo)) |
| 6141 | return -1; |
| 6142 | |
| 6143 | if (ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo) != 0) |
| 6144 | return -1; |
| 6145 | |
| 6146 | /* When GDBSERVER is built as a 64-bit application, ptrace writes into |
| 6147 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit |
| 6148 | inferior with a 64-bit GDBSERVER should look the same as debugging it |
| 6149 | with a 32-bit GDBSERVER, we need to convert it. */ |
| 6150 | siginfo_fixup (&siginfo, inf_siginfo, 0); |
| 6151 | |
| 6152 | if (offset + len > sizeof (siginfo)) |
| 6153 | len = sizeof (siginfo) - offset; |
| 6154 | |
| 6155 | if (readbuf != NULL) |
| 6156 | memcpy (readbuf, inf_siginfo + offset, len); |
| 6157 | else |
| 6158 | { |
| 6159 | memcpy (inf_siginfo + offset, writebuf, len); |
| 6160 | |
| 6161 | /* Convert back to ptrace layout before flushing it out. */ |
| 6162 | siginfo_fixup (&siginfo, inf_siginfo, 1); |
| 6163 | |
| 6164 | if (ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo) != 0) |
| 6165 | return -1; |
| 6166 | } |
| 6167 | |
| 6168 | return len; |
| 6169 | } |
| 6170 | |
| 6171 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
| 6172 | so we notice when children change state; as the handler for the |
| 6173 | sigsuspend in my_waitpid. */ |
| 6174 | |
| 6175 | static void |
| 6176 | sigchld_handler (int signo) |
| 6177 | { |
| 6178 | int old_errno = errno; |
| 6179 | |
| 6180 | if (debug_threads) |
| 6181 | { |
| 6182 | do |
| 6183 | { |
| 6184 | /* Use the async signal safe debug function. */ |
| 6185 | if (debug_write ("sigchld_handler\n", |
| 6186 | sizeof ("sigchld_handler\n") - 1) < 0) |
| 6187 | break; /* just ignore */ |
| 6188 | } while (0); |
| 6189 | } |
| 6190 | |
| 6191 | if (target_is_async_p ()) |
| 6192 | async_file_mark (); /* trigger a linux_wait */ |
| 6193 | |
| 6194 | errno = old_errno; |
| 6195 | } |
| 6196 | |
| 6197 | static int |
| 6198 | linux_supports_non_stop (void) |
| 6199 | { |
| 6200 | return 1; |
| 6201 | } |
| 6202 | |
| 6203 | static int |
| 6204 | linux_async (int enable) |
| 6205 | { |
| 6206 | int previous = target_is_async_p (); |
| 6207 | |
| 6208 | if (debug_threads) |
| 6209 | debug_printf ("linux_async (%d), previous=%d\n", |
| 6210 | enable, previous); |
| 6211 | |
| 6212 | if (previous != enable) |
| 6213 | { |
| 6214 | sigset_t mask; |
| 6215 | sigemptyset (&mask); |
| 6216 | sigaddset (&mask, SIGCHLD); |
| 6217 | |
| 6218 | sigprocmask (SIG_BLOCK, &mask, NULL); |
| 6219 | |
| 6220 | if (enable) |
| 6221 | { |
| 6222 | if (pipe (linux_event_pipe) == -1) |
| 6223 | { |
| 6224 | linux_event_pipe[0] = -1; |
| 6225 | linux_event_pipe[1] = -1; |
| 6226 | sigprocmask (SIG_UNBLOCK, &mask, NULL); |
| 6227 | |
| 6228 | warning ("creating event pipe failed."); |
| 6229 | return previous; |
| 6230 | } |
| 6231 | |
| 6232 | fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK); |
| 6233 | fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK); |
| 6234 | |
| 6235 | /* Register the event loop handler. */ |
| 6236 | add_file_handler (linux_event_pipe[0], |
| 6237 | handle_target_event, NULL); |
| 6238 | |
| 6239 | /* Always trigger a linux_wait. */ |
| 6240 | async_file_mark (); |
| 6241 | } |
| 6242 | else |
| 6243 | { |
| 6244 | delete_file_handler (linux_event_pipe[0]); |
| 6245 | |
| 6246 | close (linux_event_pipe[0]); |
| 6247 | close (linux_event_pipe[1]); |
| 6248 | linux_event_pipe[0] = -1; |
| 6249 | linux_event_pipe[1] = -1; |
| 6250 | } |
| 6251 | |
| 6252 | sigprocmask (SIG_UNBLOCK, &mask, NULL); |
| 6253 | } |
| 6254 | |
| 6255 | return previous; |
| 6256 | } |
| 6257 | |
| 6258 | static int |
| 6259 | linux_start_non_stop (int nonstop) |
| 6260 | { |
| 6261 | /* Register or unregister from event-loop accordingly. */ |
| 6262 | linux_async (nonstop); |
| 6263 | |
| 6264 | if (target_is_async_p () != (nonstop != 0)) |
| 6265 | return -1; |
| 6266 | |
| 6267 | return 0; |
| 6268 | } |
| 6269 | |
| 6270 | static int |
| 6271 | linux_supports_multi_process (void) |
| 6272 | { |
| 6273 | return 1; |
| 6274 | } |
| 6275 | |
| 6276 | /* Check if fork events are supported. */ |
| 6277 | |
| 6278 | static int |
| 6279 | linux_supports_fork_events (void) |
| 6280 | { |
| 6281 | return linux_supports_tracefork (); |
| 6282 | } |
| 6283 | |
| 6284 | /* Check if vfork events are supported. */ |
| 6285 | |
| 6286 | static int |
| 6287 | linux_supports_vfork_events (void) |
| 6288 | { |
| 6289 | return linux_supports_tracefork (); |
| 6290 | } |
| 6291 | |
| 6292 | /* Check if exec events are supported. */ |
| 6293 | |
| 6294 | static int |
| 6295 | linux_supports_exec_events (void) |
| 6296 | { |
| 6297 | return linux_supports_traceexec (); |
| 6298 | } |
| 6299 | |
| 6300 | /* Target hook for 'handle_new_gdb_connection'. Causes a reset of the |
| 6301 | ptrace flags for all inferiors. This is in case the new GDB connection |
| 6302 | doesn't support the same set of events that the previous one did. */ |
| 6303 | |
| 6304 | static void |
| 6305 | linux_handle_new_gdb_connection (void) |
| 6306 | { |
| 6307 | /* Request that all the lwps reset their ptrace options. */ |
| 6308 | for_each_thread ([] (thread_info *thread) |
| 6309 | { |
| 6310 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 6311 | |
| 6312 | if (!lwp->stopped) |
| 6313 | { |
| 6314 | /* Stop the lwp so we can modify its ptrace options. */ |
| 6315 | lwp->must_set_ptrace_flags = 1; |
| 6316 | linux_stop_lwp (lwp); |
| 6317 | } |
| 6318 | else |
| 6319 | { |
| 6320 | /* Already stopped; go ahead and set the ptrace options. */ |
| 6321 | struct process_info *proc = find_process_pid (pid_of (thread)); |
| 6322 | int options = linux_low_ptrace_options (proc->attached); |
| 6323 | |
| 6324 | linux_enable_event_reporting (lwpid_of (thread), options); |
| 6325 | lwp->must_set_ptrace_flags = 0; |
| 6326 | } |
| 6327 | }); |
| 6328 | } |
| 6329 | |
| 6330 | static int |
| 6331 | linux_supports_disable_randomization (void) |
| 6332 | { |
| 6333 | #ifdef HAVE_PERSONALITY |
| 6334 | return 1; |
| 6335 | #else |
| 6336 | return 0; |
| 6337 | #endif |
| 6338 | } |
| 6339 | |
| 6340 | static int |
| 6341 | linux_supports_agent (void) |
| 6342 | { |
| 6343 | return 1; |
| 6344 | } |
| 6345 | |
| 6346 | static int |
| 6347 | linux_supports_range_stepping (void) |
| 6348 | { |
| 6349 | if (can_software_single_step ()) |
| 6350 | return 1; |
| 6351 | if (*the_low_target.supports_range_stepping == NULL) |
| 6352 | return 0; |
| 6353 | |
| 6354 | return (*the_low_target.supports_range_stepping) (); |
| 6355 | } |
| 6356 | |
| 6357 | #if defined PT_GETDSBT || defined PTRACE_GETFDPIC |
| 6358 | struct target_loadseg |
| 6359 | { |
| 6360 | /* Core address to which the segment is mapped. */ |
| 6361 | Elf32_Addr addr; |
| 6362 | /* VMA recorded in the program header. */ |
| 6363 | Elf32_Addr p_vaddr; |
| 6364 | /* Size of this segment in memory. */ |
| 6365 | Elf32_Word p_memsz; |
| 6366 | }; |
| 6367 | |
| 6368 | # if defined PT_GETDSBT |
| 6369 | struct target_loadmap |
| 6370 | { |
| 6371 | /* Protocol version number, must be zero. */ |
| 6372 | Elf32_Word version; |
| 6373 | /* Pointer to the DSBT table, its size, and the DSBT index. */ |
| 6374 | unsigned *dsbt_table; |
| 6375 | unsigned dsbt_size, dsbt_index; |
| 6376 | /* Number of segments in this map. */ |
| 6377 | Elf32_Word nsegs; |
| 6378 | /* The actual memory map. */ |
| 6379 | struct target_loadseg segs[/*nsegs*/]; |
| 6380 | }; |
| 6381 | # define LINUX_LOADMAP PT_GETDSBT |
| 6382 | # define LINUX_LOADMAP_EXEC PTRACE_GETDSBT_EXEC |
| 6383 | # define LINUX_LOADMAP_INTERP PTRACE_GETDSBT_INTERP |
| 6384 | # else |
| 6385 | struct target_loadmap |
| 6386 | { |
| 6387 | /* Protocol version number, must be zero. */ |
| 6388 | Elf32_Half version; |
| 6389 | /* Number of segments in this map. */ |
| 6390 | Elf32_Half nsegs; |
| 6391 | /* The actual memory map. */ |
| 6392 | struct target_loadseg segs[/*nsegs*/]; |
| 6393 | }; |
| 6394 | # define LINUX_LOADMAP PTRACE_GETFDPIC |
| 6395 | # define LINUX_LOADMAP_EXEC PTRACE_GETFDPIC_EXEC |
| 6396 | # define LINUX_LOADMAP_INTERP PTRACE_GETFDPIC_INTERP |
| 6397 | # endif |
| 6398 | |
| 6399 | static int |
| 6400 | linux_read_loadmap (const char *annex, CORE_ADDR offset, |
| 6401 | unsigned char *myaddr, unsigned int len) |
| 6402 | { |
| 6403 | int pid = lwpid_of (current_thread); |
| 6404 | int addr = -1; |
| 6405 | struct target_loadmap *data = NULL; |
| 6406 | unsigned int actual_length, copy_length; |
| 6407 | |
| 6408 | if (strcmp (annex, "exec") == 0) |
| 6409 | addr = (int) LINUX_LOADMAP_EXEC; |
| 6410 | else if (strcmp (annex, "interp") == 0) |
| 6411 | addr = (int) LINUX_LOADMAP_INTERP; |
| 6412 | else |
| 6413 | return -1; |
| 6414 | |
| 6415 | if (ptrace (LINUX_LOADMAP, pid, addr, &data) != 0) |
| 6416 | return -1; |
| 6417 | |
| 6418 | if (data == NULL) |
| 6419 | return -1; |
| 6420 | |
| 6421 | actual_length = sizeof (struct target_loadmap) |
| 6422 | + sizeof (struct target_loadseg) * data->nsegs; |
| 6423 | |
| 6424 | if (offset < 0 || offset > actual_length) |
| 6425 | return -1; |
| 6426 | |
| 6427 | copy_length = actual_length - offset < len ? actual_length - offset : len; |
| 6428 | memcpy (myaddr, (char *) data + offset, copy_length); |
| 6429 | return copy_length; |
| 6430 | } |
| 6431 | #else |
| 6432 | # define linux_read_loadmap NULL |
| 6433 | #endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */ |
| 6434 | |
| 6435 | static void |
| 6436 | linux_process_qsupported (char **features, int count) |
| 6437 | { |
| 6438 | if (the_low_target.process_qsupported != NULL) |
| 6439 | the_low_target.process_qsupported (features, count); |
| 6440 | } |
| 6441 | |
| 6442 | static int |
| 6443 | linux_supports_catch_syscall (void) |
| 6444 | { |
| 6445 | return (the_low_target.get_syscall_trapinfo != NULL |
| 6446 | && linux_supports_tracesysgood ()); |
| 6447 | } |
| 6448 | |
| 6449 | static int |
| 6450 | linux_get_ipa_tdesc_idx (void) |
| 6451 | { |
| 6452 | if (the_low_target.get_ipa_tdesc_idx == NULL) |
| 6453 | return 0; |
| 6454 | |
| 6455 | return (*the_low_target.get_ipa_tdesc_idx) (); |
| 6456 | } |
| 6457 | |
| 6458 | static int |
| 6459 | linux_supports_tracepoints (void) |
| 6460 | { |
| 6461 | if (*the_low_target.supports_tracepoints == NULL) |
| 6462 | return 0; |
| 6463 | |
| 6464 | return (*the_low_target.supports_tracepoints) (); |
| 6465 | } |
| 6466 | |
| 6467 | static CORE_ADDR |
| 6468 | linux_read_pc (struct regcache *regcache) |
| 6469 | { |
| 6470 | if (the_low_target.get_pc == NULL) |
| 6471 | return 0; |
| 6472 | |
| 6473 | return (*the_low_target.get_pc) (regcache); |
| 6474 | } |
| 6475 | |
| 6476 | static void |
| 6477 | linux_write_pc (struct regcache *regcache, CORE_ADDR pc) |
| 6478 | { |
| 6479 | gdb_assert (the_low_target.set_pc != NULL); |
| 6480 | |
| 6481 | (*the_low_target.set_pc) (regcache, pc); |
| 6482 | } |
| 6483 | |
| 6484 | static int |
| 6485 | linux_thread_stopped (struct thread_info *thread) |
| 6486 | { |
| 6487 | return get_thread_lwp (thread)->stopped; |
| 6488 | } |
| 6489 | |
| 6490 | /* This exposes stop-all-threads functionality to other modules. */ |
| 6491 | |
| 6492 | static void |
| 6493 | linux_pause_all (int freeze) |
| 6494 | { |
| 6495 | stop_all_lwps (freeze, NULL); |
| 6496 | } |
| 6497 | |
| 6498 | /* This exposes unstop-all-threads functionality to other gdbserver |
| 6499 | modules. */ |
| 6500 | |
| 6501 | static void |
| 6502 | linux_unpause_all (int unfreeze) |
| 6503 | { |
| 6504 | unstop_all_lwps (unfreeze, NULL); |
| 6505 | } |
| 6506 | |
| 6507 | static int |
| 6508 | linux_prepare_to_access_memory (void) |
| 6509 | { |
| 6510 | /* Neither ptrace nor /proc/PID/mem allow accessing memory through a |
| 6511 | running LWP. */ |
| 6512 | if (non_stop) |
| 6513 | linux_pause_all (1); |
| 6514 | return 0; |
| 6515 | } |
| 6516 | |
| 6517 | static void |
| 6518 | linux_done_accessing_memory (void) |
| 6519 | { |
| 6520 | /* Neither ptrace nor /proc/PID/mem allow accessing memory through a |
| 6521 | running LWP. */ |
| 6522 | if (non_stop) |
| 6523 | linux_unpause_all (1); |
| 6524 | } |
| 6525 | |
| 6526 | static int |
| 6527 | linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr, |
| 6528 | CORE_ADDR collector, |
| 6529 | CORE_ADDR lockaddr, |
| 6530 | ULONGEST orig_size, |
| 6531 | CORE_ADDR *jump_entry, |
| 6532 | CORE_ADDR *trampoline, |
| 6533 | ULONGEST *trampoline_size, |
| 6534 | unsigned char *jjump_pad_insn, |
| 6535 | ULONGEST *jjump_pad_insn_size, |
| 6536 | CORE_ADDR *adjusted_insn_addr, |
| 6537 | CORE_ADDR *adjusted_insn_addr_end, |
| 6538 | char *err) |
| 6539 | { |
| 6540 | return (*the_low_target.install_fast_tracepoint_jump_pad) |
| 6541 | (tpoint, tpaddr, collector, lockaddr, orig_size, |
| 6542 | jump_entry, trampoline, trampoline_size, |
| 6543 | jjump_pad_insn, jjump_pad_insn_size, |
| 6544 | adjusted_insn_addr, adjusted_insn_addr_end, |
| 6545 | err); |
| 6546 | } |
| 6547 | |
| 6548 | static struct emit_ops * |
| 6549 | linux_emit_ops (void) |
| 6550 | { |
| 6551 | if (the_low_target.emit_ops != NULL) |
| 6552 | return (*the_low_target.emit_ops) (); |
| 6553 | else |
| 6554 | return NULL; |
| 6555 | } |
| 6556 | |
| 6557 | static int |
| 6558 | linux_get_min_fast_tracepoint_insn_len (void) |
| 6559 | { |
| 6560 | return (*the_low_target.get_min_fast_tracepoint_insn_len) (); |
| 6561 | } |
| 6562 | |
| 6563 | /* Extract &phdr and num_phdr in the inferior. Return 0 on success. */ |
| 6564 | |
| 6565 | static int |
| 6566 | get_phdr_phnum_from_proc_auxv (const int pid, const int is_elf64, |
| 6567 | CORE_ADDR *phdr_memaddr, int *num_phdr) |
| 6568 | { |
| 6569 | char filename[PATH_MAX]; |
| 6570 | int fd; |
| 6571 | const int auxv_size = is_elf64 |
| 6572 | ? sizeof (Elf64_auxv_t) : sizeof (Elf32_auxv_t); |
| 6573 | char buf[sizeof (Elf64_auxv_t)]; /* The larger of the two. */ |
| 6574 | |
| 6575 | xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid); |
| 6576 | |
| 6577 | fd = open (filename, O_RDONLY); |
| 6578 | if (fd < 0) |
| 6579 | return 1; |
| 6580 | |
| 6581 | *phdr_memaddr = 0; |
| 6582 | *num_phdr = 0; |
| 6583 | while (read (fd, buf, auxv_size) == auxv_size |
| 6584 | && (*phdr_memaddr == 0 || *num_phdr == 0)) |
| 6585 | { |
| 6586 | if (is_elf64) |
| 6587 | { |
| 6588 | Elf64_auxv_t *const aux = (Elf64_auxv_t *) buf; |
| 6589 | |
| 6590 | switch (aux->a_type) |
| 6591 | { |
| 6592 | case AT_PHDR: |
| 6593 | *phdr_memaddr = aux->a_un.a_val; |
| 6594 | break; |
| 6595 | case AT_PHNUM: |
| 6596 | *num_phdr = aux->a_un.a_val; |
| 6597 | break; |
| 6598 | } |
| 6599 | } |
| 6600 | else |
| 6601 | { |
| 6602 | Elf32_auxv_t *const aux = (Elf32_auxv_t *) buf; |
| 6603 | |
| 6604 | switch (aux->a_type) |
| 6605 | { |
| 6606 | case AT_PHDR: |
| 6607 | *phdr_memaddr = aux->a_un.a_val; |
| 6608 | break; |
| 6609 | case AT_PHNUM: |
| 6610 | *num_phdr = aux->a_un.a_val; |
| 6611 | break; |
| 6612 | } |
| 6613 | } |
| 6614 | } |
| 6615 | |
| 6616 | close (fd); |
| 6617 | |
| 6618 | if (*phdr_memaddr == 0 || *num_phdr == 0) |
| 6619 | { |
| 6620 | warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: " |
| 6621 | "phdr_memaddr = %ld, phdr_num = %d", |
| 6622 | (long) *phdr_memaddr, *num_phdr); |
| 6623 | return 2; |
| 6624 | } |
| 6625 | |
| 6626 | return 0; |
| 6627 | } |
| 6628 | |
| 6629 | /* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */ |
| 6630 | |
| 6631 | static CORE_ADDR |
| 6632 | get_dynamic (const int pid, const int is_elf64) |
| 6633 | { |
| 6634 | CORE_ADDR phdr_memaddr, relocation; |
| 6635 | int num_phdr, i; |
| 6636 | unsigned char *phdr_buf; |
| 6637 | const int phdr_size = is_elf64 ? sizeof (Elf64_Phdr) : sizeof (Elf32_Phdr); |
| 6638 | |
| 6639 | if (get_phdr_phnum_from_proc_auxv (pid, is_elf64, &phdr_memaddr, &num_phdr)) |
| 6640 | return 0; |
| 6641 | |
| 6642 | gdb_assert (num_phdr < 100); /* Basic sanity check. */ |
| 6643 | phdr_buf = (unsigned char *) alloca (num_phdr * phdr_size); |
| 6644 | |
| 6645 | if (linux_read_memory (phdr_memaddr, phdr_buf, num_phdr * phdr_size)) |
| 6646 | return 0; |
| 6647 | |
| 6648 | /* Compute relocation: it is expected to be 0 for "regular" executables, |
| 6649 | non-zero for PIE ones. */ |
| 6650 | relocation = -1; |
| 6651 | for (i = 0; relocation == -1 && i < num_phdr; i++) |
| 6652 | if (is_elf64) |
| 6653 | { |
| 6654 | Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size); |
| 6655 | |
| 6656 | if (p->p_type == PT_PHDR) |
| 6657 | relocation = phdr_memaddr - p->p_vaddr; |
| 6658 | } |
| 6659 | else |
| 6660 | { |
| 6661 | Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size); |
| 6662 | |
| 6663 | if (p->p_type == PT_PHDR) |
| 6664 | relocation = phdr_memaddr - p->p_vaddr; |
| 6665 | } |
| 6666 | |
| 6667 | if (relocation == -1) |
| 6668 | { |
| 6669 | /* PT_PHDR is optional, but necessary for PIE in general. Fortunately |
| 6670 | any real world executables, including PIE executables, have always |
| 6671 | PT_PHDR present. PT_PHDR is not present in some shared libraries or |
| 6672 | in fpc (Free Pascal 2.4) binaries but neither of those have a need for |
| 6673 | or present DT_DEBUG anyway (fpc binaries are statically linked). |
| 6674 | |
| 6675 | Therefore if there exists DT_DEBUG there is always also PT_PHDR. |
| 6676 | |
| 6677 | GDB could find RELOCATION also from AT_ENTRY - e_entry. */ |
| 6678 | |
| 6679 | return 0; |
| 6680 | } |
| 6681 | |
| 6682 | for (i = 0; i < num_phdr; i++) |
| 6683 | { |
| 6684 | if (is_elf64) |
| 6685 | { |
| 6686 | Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size); |
| 6687 | |
| 6688 | if (p->p_type == PT_DYNAMIC) |
| 6689 | return p->p_vaddr + relocation; |
| 6690 | } |
| 6691 | else |
| 6692 | { |
| 6693 | Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size); |
| 6694 | |
| 6695 | if (p->p_type == PT_DYNAMIC) |
| 6696 | return p->p_vaddr + relocation; |
| 6697 | } |
| 6698 | } |
| 6699 | |
| 6700 | return 0; |
| 6701 | } |
| 6702 | |
| 6703 | /* Return &_r_debug in the inferior, or -1 if not present. Return value |
| 6704 | can be 0 if the inferior does not yet have the library list initialized. |
| 6705 | We look for DT_MIPS_RLD_MAP first. MIPS executables use this instead of |
| 6706 | DT_DEBUG, although they sometimes contain an unused DT_DEBUG entry too. */ |
| 6707 | |
| 6708 | static CORE_ADDR |
| 6709 | get_r_debug (const int pid, const int is_elf64) |
| 6710 | { |
| 6711 | CORE_ADDR dynamic_memaddr; |
| 6712 | const int dyn_size = is_elf64 ? sizeof (Elf64_Dyn) : sizeof (Elf32_Dyn); |
| 6713 | unsigned char buf[sizeof (Elf64_Dyn)]; /* The larger of the two. */ |
| 6714 | CORE_ADDR map = -1; |
| 6715 | |
| 6716 | dynamic_memaddr = get_dynamic (pid, is_elf64); |
| 6717 | if (dynamic_memaddr == 0) |
| 6718 | return map; |
| 6719 | |
| 6720 | while (linux_read_memory (dynamic_memaddr, buf, dyn_size) == 0) |
| 6721 | { |
| 6722 | if (is_elf64) |
| 6723 | { |
| 6724 | Elf64_Dyn *const dyn = (Elf64_Dyn *) buf; |
| 6725 | #if defined DT_MIPS_RLD_MAP || defined DT_MIPS_RLD_MAP_REL |
| 6726 | union |
| 6727 | { |
| 6728 | Elf64_Xword map; |
| 6729 | unsigned char buf[sizeof (Elf64_Xword)]; |
| 6730 | } |
| 6731 | rld_map; |
| 6732 | #endif |
| 6733 | #ifdef DT_MIPS_RLD_MAP |
| 6734 | if (dyn->d_tag == DT_MIPS_RLD_MAP) |
| 6735 | { |
| 6736 | if (linux_read_memory (dyn->d_un.d_val, |
| 6737 | rld_map.buf, sizeof (rld_map.buf)) == 0) |
| 6738 | return rld_map.map; |
| 6739 | else |
| 6740 | break; |
| 6741 | } |
| 6742 | #endif /* DT_MIPS_RLD_MAP */ |
| 6743 | #ifdef DT_MIPS_RLD_MAP_REL |
| 6744 | if (dyn->d_tag == DT_MIPS_RLD_MAP_REL) |
| 6745 | { |
| 6746 | if (linux_read_memory (dyn->d_un.d_val + dynamic_memaddr, |
| 6747 | rld_map.buf, sizeof (rld_map.buf)) == 0) |
| 6748 | return rld_map.map; |
| 6749 | else |
| 6750 | break; |
| 6751 | } |
| 6752 | #endif /* DT_MIPS_RLD_MAP_REL */ |
| 6753 | |
| 6754 | if (dyn->d_tag == DT_DEBUG && map == -1) |
| 6755 | map = dyn->d_un.d_val; |
| 6756 | |
| 6757 | if (dyn->d_tag == DT_NULL) |
| 6758 | break; |
| 6759 | } |
| 6760 | else |
| 6761 | { |
| 6762 | Elf32_Dyn *const dyn = (Elf32_Dyn *) buf; |
| 6763 | #if defined DT_MIPS_RLD_MAP || defined DT_MIPS_RLD_MAP_REL |
| 6764 | union |
| 6765 | { |
| 6766 | Elf32_Word map; |
| 6767 | unsigned char buf[sizeof (Elf32_Word)]; |
| 6768 | } |
| 6769 | rld_map; |
| 6770 | #endif |
| 6771 | #ifdef DT_MIPS_RLD_MAP |
| 6772 | if (dyn->d_tag == DT_MIPS_RLD_MAP) |
| 6773 | { |
| 6774 | if (linux_read_memory (dyn->d_un.d_val, |
| 6775 | rld_map.buf, sizeof (rld_map.buf)) == 0) |
| 6776 | return rld_map.map; |
| 6777 | else |
| 6778 | break; |
| 6779 | } |
| 6780 | #endif /* DT_MIPS_RLD_MAP */ |
| 6781 | #ifdef DT_MIPS_RLD_MAP_REL |
| 6782 | if (dyn->d_tag == DT_MIPS_RLD_MAP_REL) |
| 6783 | { |
| 6784 | if (linux_read_memory (dyn->d_un.d_val + dynamic_memaddr, |
| 6785 | rld_map.buf, sizeof (rld_map.buf)) == 0) |
| 6786 | return rld_map.map; |
| 6787 | else |
| 6788 | break; |
| 6789 | } |
| 6790 | #endif /* DT_MIPS_RLD_MAP_REL */ |
| 6791 | |
| 6792 | if (dyn->d_tag == DT_DEBUG && map == -1) |
| 6793 | map = dyn->d_un.d_val; |
| 6794 | |
| 6795 | if (dyn->d_tag == DT_NULL) |
| 6796 | break; |
| 6797 | } |
| 6798 | |
| 6799 | dynamic_memaddr += dyn_size; |
| 6800 | } |
| 6801 | |
| 6802 | return map; |
| 6803 | } |
| 6804 | |
| 6805 | /* Read one pointer from MEMADDR in the inferior. */ |
| 6806 | |
| 6807 | static int |
| 6808 | read_one_ptr (CORE_ADDR memaddr, CORE_ADDR *ptr, int ptr_size) |
| 6809 | { |
| 6810 | int ret; |
| 6811 | |
| 6812 | /* Go through a union so this works on either big or little endian |
| 6813 | hosts, when the inferior's pointer size is smaller than the size |
| 6814 | of CORE_ADDR. It is assumed the inferior's endianness is the |
| 6815 | same of the superior's. */ |
| 6816 | union |
| 6817 | { |
| 6818 | CORE_ADDR core_addr; |
| 6819 | unsigned int ui; |
| 6820 | unsigned char uc; |
| 6821 | } addr; |
| 6822 | |
| 6823 | ret = linux_read_memory (memaddr, &addr.uc, ptr_size); |
| 6824 | if (ret == 0) |
| 6825 | { |
| 6826 | if (ptr_size == sizeof (CORE_ADDR)) |
| 6827 | *ptr = addr.core_addr; |
| 6828 | else if (ptr_size == sizeof (unsigned int)) |
| 6829 | *ptr = addr.ui; |
| 6830 | else |
| 6831 | gdb_assert_not_reached ("unhandled pointer size"); |
| 6832 | } |
| 6833 | return ret; |
| 6834 | } |
| 6835 | |
| 6836 | struct link_map_offsets |
| 6837 | { |
| 6838 | /* Offset and size of r_debug.r_version. */ |
| 6839 | int r_version_offset; |
| 6840 | |
| 6841 | /* Offset and size of r_debug.r_map. */ |
| 6842 | int r_map_offset; |
| 6843 | |
| 6844 | /* Offset to l_addr field in struct link_map. */ |
| 6845 | int l_addr_offset; |
| 6846 | |
| 6847 | /* Offset to l_name field in struct link_map. */ |
| 6848 | int l_name_offset; |
| 6849 | |
| 6850 | /* Offset to l_ld field in struct link_map. */ |
| 6851 | int l_ld_offset; |
| 6852 | |
| 6853 | /* Offset to l_next field in struct link_map. */ |
| 6854 | int l_next_offset; |
| 6855 | |
| 6856 | /* Offset to l_prev field in struct link_map. */ |
| 6857 | int l_prev_offset; |
| 6858 | }; |
| 6859 | |
| 6860 | /* Construct qXfer:libraries-svr4:read reply. */ |
| 6861 | |
| 6862 | static int |
| 6863 | linux_qxfer_libraries_svr4 (const char *annex, unsigned char *readbuf, |
| 6864 | unsigned const char *writebuf, |
| 6865 | CORE_ADDR offset, int len) |
| 6866 | { |
| 6867 | struct process_info_private *const priv = current_process ()->priv; |
| 6868 | char filename[PATH_MAX]; |
| 6869 | int pid, is_elf64; |
| 6870 | |
| 6871 | static const struct link_map_offsets lmo_32bit_offsets = |
| 6872 | { |
| 6873 | 0, /* r_version offset. */ |
| 6874 | 4, /* r_debug.r_map offset. */ |
| 6875 | 0, /* l_addr offset in link_map. */ |
| 6876 | 4, /* l_name offset in link_map. */ |
| 6877 | 8, /* l_ld offset in link_map. */ |
| 6878 | 12, /* l_next offset in link_map. */ |
| 6879 | 16 /* l_prev offset in link_map. */ |
| 6880 | }; |
| 6881 | |
| 6882 | static const struct link_map_offsets lmo_64bit_offsets = |
| 6883 | { |
| 6884 | 0, /* r_version offset. */ |
| 6885 | 8, /* r_debug.r_map offset. */ |
| 6886 | 0, /* l_addr offset in link_map. */ |
| 6887 | 8, /* l_name offset in link_map. */ |
| 6888 | 16, /* l_ld offset in link_map. */ |
| 6889 | 24, /* l_next offset in link_map. */ |
| 6890 | 32 /* l_prev offset in link_map. */ |
| 6891 | }; |
| 6892 | const struct link_map_offsets *lmo; |
| 6893 | unsigned int machine; |
| 6894 | int ptr_size; |
| 6895 | CORE_ADDR lm_addr = 0, lm_prev = 0; |
| 6896 | CORE_ADDR l_name, l_addr, l_ld, l_next, l_prev; |
| 6897 | int header_done = 0; |
| 6898 | |
| 6899 | if (writebuf != NULL) |
| 6900 | return -2; |
| 6901 | if (readbuf == NULL) |
| 6902 | return -1; |
| 6903 | |
| 6904 | pid = lwpid_of (current_thread); |
| 6905 | xsnprintf (filename, sizeof filename, "/proc/%d/exe", pid); |
| 6906 | is_elf64 = elf_64_file_p (filename, &machine); |
| 6907 | lmo = is_elf64 ? &lmo_64bit_offsets : &lmo_32bit_offsets; |
| 6908 | ptr_size = is_elf64 ? 8 : 4; |
| 6909 | |
| 6910 | while (annex[0] != '\0') |
| 6911 | { |
| 6912 | const char *sep; |
| 6913 | CORE_ADDR *addrp; |
| 6914 | int name_len; |
| 6915 | |
| 6916 | sep = strchr (annex, '='); |
| 6917 | if (sep == NULL) |
| 6918 | break; |
| 6919 | |
| 6920 | name_len = sep - annex; |
| 6921 | if (name_len == 5 && startswith (annex, "start")) |
| 6922 | addrp = &lm_addr; |
| 6923 | else if (name_len == 4 && startswith (annex, "prev")) |
| 6924 | addrp = &lm_prev; |
| 6925 | else |
| 6926 | { |
| 6927 | annex = strchr (sep, ';'); |
| 6928 | if (annex == NULL) |
| 6929 | break; |
| 6930 | annex++; |
| 6931 | continue; |
| 6932 | } |
| 6933 | |
| 6934 | annex = decode_address_to_semicolon (addrp, sep + 1); |
| 6935 | } |
| 6936 | |
| 6937 | if (lm_addr == 0) |
| 6938 | { |
| 6939 | int r_version = 0; |
| 6940 | |
| 6941 | if (priv->r_debug == 0) |
| 6942 | priv->r_debug = get_r_debug (pid, is_elf64); |
| 6943 | |
| 6944 | /* We failed to find DT_DEBUG. Such situation will not change |
| 6945 | for this inferior - do not retry it. Report it to GDB as |
| 6946 | E01, see for the reasons at the GDB solib-svr4.c side. */ |
| 6947 | if (priv->r_debug == (CORE_ADDR) -1) |
| 6948 | return -1; |
| 6949 | |
| 6950 | if (priv->r_debug != 0) |
| 6951 | { |
| 6952 | if (linux_read_memory (priv->r_debug + lmo->r_version_offset, |
| 6953 | (unsigned char *) &r_version, |
| 6954 | sizeof (r_version)) != 0 |
| 6955 | || r_version != 1) |
| 6956 | { |
| 6957 | warning ("unexpected r_debug version %d", r_version); |
| 6958 | } |
| 6959 | else if (read_one_ptr (priv->r_debug + lmo->r_map_offset, |
| 6960 | &lm_addr, ptr_size) != 0) |
| 6961 | { |
| 6962 | warning ("unable to read r_map from 0x%lx", |
| 6963 | (long) priv->r_debug + lmo->r_map_offset); |
| 6964 | } |
| 6965 | } |
| 6966 | } |
| 6967 | |
| 6968 | std::string document = "<library-list-svr4 version=\"1.0\""; |
| 6969 | |
| 6970 | while (lm_addr |
| 6971 | && read_one_ptr (lm_addr + lmo->l_name_offset, |
| 6972 | &l_name, ptr_size) == 0 |
| 6973 | && read_one_ptr (lm_addr + lmo->l_addr_offset, |
| 6974 | &l_addr, ptr_size) == 0 |
| 6975 | && read_one_ptr (lm_addr + lmo->l_ld_offset, |
| 6976 | &l_ld, ptr_size) == 0 |
| 6977 | && read_one_ptr (lm_addr + lmo->l_prev_offset, |
| 6978 | &l_prev, ptr_size) == 0 |
| 6979 | && read_one_ptr (lm_addr + lmo->l_next_offset, |
| 6980 | &l_next, ptr_size) == 0) |
| 6981 | { |
| 6982 | unsigned char libname[PATH_MAX]; |
| 6983 | |
| 6984 | if (lm_prev != l_prev) |
| 6985 | { |
| 6986 | warning ("Corrupted shared library list: 0x%lx != 0x%lx", |
| 6987 | (long) lm_prev, (long) l_prev); |
| 6988 | break; |
| 6989 | } |
| 6990 | |
| 6991 | /* Ignore the first entry even if it has valid name as the first entry |
| 6992 | corresponds to the main executable. The first entry should not be |
| 6993 | skipped if the dynamic loader was loaded late by a static executable |
| 6994 | (see solib-svr4.c parameter ignore_first). But in such case the main |
| 6995 | executable does not have PT_DYNAMIC present and this function already |
| 6996 | exited above due to failed get_r_debug. */ |
| 6997 | if (lm_prev == 0) |
| 6998 | string_appendf (document, " main-lm=\"0x%lx\"", (unsigned long) lm_addr); |
| 6999 | else |
| 7000 | { |
| 7001 | /* Not checking for error because reading may stop before |
| 7002 | we've got PATH_MAX worth of characters. */ |
| 7003 | libname[0] = '\0'; |
| 7004 | linux_read_memory (l_name, libname, sizeof (libname) - 1); |
| 7005 | libname[sizeof (libname) - 1] = '\0'; |
| 7006 | if (libname[0] != '\0') |
| 7007 | { |
| 7008 | if (!header_done) |
| 7009 | { |
| 7010 | /* Terminate `<library-list-svr4'. */ |
| 7011 | document += '>'; |
| 7012 | header_done = 1; |
| 7013 | } |
| 7014 | |
| 7015 | string_appendf (document, "<library name=\""); |
| 7016 | xml_escape_text_append (&document, (char *) libname); |
| 7017 | string_appendf (document, "\" lm=\"0x%lx\" " |
| 7018 | "l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>", |
| 7019 | (unsigned long) lm_addr, (unsigned long) l_addr, |
| 7020 | (unsigned long) l_ld); |
| 7021 | } |
| 7022 | } |
| 7023 | |
| 7024 | lm_prev = lm_addr; |
| 7025 | lm_addr = l_next; |
| 7026 | } |
| 7027 | |
| 7028 | if (!header_done) |
| 7029 | { |
| 7030 | /* Empty list; terminate `<library-list-svr4'. */ |
| 7031 | document += "/>"; |
| 7032 | } |
| 7033 | else |
| 7034 | document += "</library-list-svr4>"; |
| 7035 | |
| 7036 | int document_len = document.length (); |
| 7037 | if (offset < document_len) |
| 7038 | document_len -= offset; |
| 7039 | else |
| 7040 | document_len = 0; |
| 7041 | if (len > document_len) |
| 7042 | len = document_len; |
| 7043 | |
| 7044 | memcpy (readbuf, document.data () + offset, len); |
| 7045 | |
| 7046 | return len; |
| 7047 | } |
| 7048 | |
| 7049 | #ifdef HAVE_LINUX_BTRACE |
| 7050 | |
| 7051 | /* See to_disable_btrace target method. */ |
| 7052 | |
| 7053 | static int |
| 7054 | linux_low_disable_btrace (struct btrace_target_info *tinfo) |
| 7055 | { |
| 7056 | enum btrace_error err; |
| 7057 | |
| 7058 | err = linux_disable_btrace (tinfo); |
| 7059 | return (err == BTRACE_ERR_NONE ? 0 : -1); |
| 7060 | } |
| 7061 | |
| 7062 | /* Encode an Intel Processor Trace configuration. */ |
| 7063 | |
| 7064 | static void |
| 7065 | linux_low_encode_pt_config (struct buffer *buffer, |
| 7066 | const struct btrace_data_pt_config *config) |
| 7067 | { |
| 7068 | buffer_grow_str (buffer, "<pt-config>\n"); |
| 7069 | |
| 7070 | switch (config->cpu.vendor) |
| 7071 | { |
| 7072 | case CV_INTEL: |
| 7073 | buffer_xml_printf (buffer, "<cpu vendor=\"GenuineIntel\" family=\"%u\" " |
| 7074 | "model=\"%u\" stepping=\"%u\"/>\n", |
| 7075 | config->cpu.family, config->cpu.model, |
| 7076 | config->cpu.stepping); |
| 7077 | break; |
| 7078 | |
| 7079 | default: |
| 7080 | break; |
| 7081 | } |
| 7082 | |
| 7083 | buffer_grow_str (buffer, "</pt-config>\n"); |
| 7084 | } |
| 7085 | |
| 7086 | /* Encode a raw buffer. */ |
| 7087 | |
| 7088 | static void |
| 7089 | linux_low_encode_raw (struct buffer *buffer, const gdb_byte *data, |
| 7090 | unsigned int size) |
| 7091 | { |
| 7092 | if (size == 0) |
| 7093 | return; |
| 7094 | |
| 7095 | /* We use hex encoding - see gdbsupport/rsp-low.h. */ |
| 7096 | buffer_grow_str (buffer, "<raw>\n"); |
| 7097 | |
| 7098 | while (size-- > 0) |
| 7099 | { |
| 7100 | char elem[2]; |
| 7101 | |
| 7102 | elem[0] = tohex ((*data >> 4) & 0xf); |
| 7103 | elem[1] = tohex (*data++ & 0xf); |
| 7104 | |
| 7105 | buffer_grow (buffer, elem, 2); |
| 7106 | } |
| 7107 | |
| 7108 | buffer_grow_str (buffer, "</raw>\n"); |
| 7109 | } |
| 7110 | |
| 7111 | /* See to_read_btrace target method. */ |
| 7112 | |
| 7113 | static int |
| 7114 | linux_low_read_btrace (struct btrace_target_info *tinfo, struct buffer *buffer, |
| 7115 | enum btrace_read_type type) |
| 7116 | { |
| 7117 | struct btrace_data btrace; |
| 7118 | struct btrace_block *block; |
| 7119 | enum btrace_error err; |
| 7120 | int i; |
| 7121 | |
| 7122 | err = linux_read_btrace (&btrace, tinfo, type); |
| 7123 | if (err != BTRACE_ERR_NONE) |
| 7124 | { |
| 7125 | if (err == BTRACE_ERR_OVERFLOW) |
| 7126 | buffer_grow_str0 (buffer, "E.Overflow."); |
| 7127 | else |
| 7128 | buffer_grow_str0 (buffer, "E.Generic Error."); |
| 7129 | |
| 7130 | return -1; |
| 7131 | } |
| 7132 | |
| 7133 | switch (btrace.format) |
| 7134 | { |
| 7135 | case BTRACE_FORMAT_NONE: |
| 7136 | buffer_grow_str0 (buffer, "E.No Trace."); |
| 7137 | return -1; |
| 7138 | |
| 7139 | case BTRACE_FORMAT_BTS: |
| 7140 | buffer_grow_str (buffer, "<!DOCTYPE btrace SYSTEM \"btrace.dtd\">\n"); |
| 7141 | buffer_grow_str (buffer, "<btrace version=\"1.0\">\n"); |
| 7142 | |
| 7143 | for (i = 0; |
| 7144 | VEC_iterate (btrace_block_s, btrace.variant.bts.blocks, i, block); |
| 7145 | i++) |
| 7146 | buffer_xml_printf (buffer, "<block begin=\"0x%s\" end=\"0x%s\"/>\n", |
| 7147 | paddress (block->begin), paddress (block->end)); |
| 7148 | |
| 7149 | buffer_grow_str0 (buffer, "</btrace>\n"); |
| 7150 | break; |
| 7151 | |
| 7152 | case BTRACE_FORMAT_PT: |
| 7153 | buffer_grow_str (buffer, "<!DOCTYPE btrace SYSTEM \"btrace.dtd\">\n"); |
| 7154 | buffer_grow_str (buffer, "<btrace version=\"1.0\">\n"); |
| 7155 | buffer_grow_str (buffer, "<pt>\n"); |
| 7156 | |
| 7157 | linux_low_encode_pt_config (buffer, &btrace.variant.pt.config); |
| 7158 | |
| 7159 | linux_low_encode_raw (buffer, btrace.variant.pt.data, |
| 7160 | btrace.variant.pt.size); |
| 7161 | |
| 7162 | buffer_grow_str (buffer, "</pt>\n"); |
| 7163 | buffer_grow_str0 (buffer, "</btrace>\n"); |
| 7164 | break; |
| 7165 | |
| 7166 | default: |
| 7167 | buffer_grow_str0 (buffer, "E.Unsupported Trace Format."); |
| 7168 | return -1; |
| 7169 | } |
| 7170 | |
| 7171 | return 0; |
| 7172 | } |
| 7173 | |
| 7174 | /* See to_btrace_conf target method. */ |
| 7175 | |
| 7176 | static int |
| 7177 | linux_low_btrace_conf (const struct btrace_target_info *tinfo, |
| 7178 | struct buffer *buffer) |
| 7179 | { |
| 7180 | const struct btrace_config *conf; |
| 7181 | |
| 7182 | buffer_grow_str (buffer, "<!DOCTYPE btrace-conf SYSTEM \"btrace-conf.dtd\">\n"); |
| 7183 | buffer_grow_str (buffer, "<btrace-conf version=\"1.0\">\n"); |
| 7184 | |
| 7185 | conf = linux_btrace_conf (tinfo); |
| 7186 | if (conf != NULL) |
| 7187 | { |
| 7188 | switch (conf->format) |
| 7189 | { |
| 7190 | case BTRACE_FORMAT_NONE: |
| 7191 | break; |
| 7192 | |
| 7193 | case BTRACE_FORMAT_BTS: |
| 7194 | buffer_xml_printf (buffer, "<bts"); |
| 7195 | buffer_xml_printf (buffer, " size=\"0x%x\"", conf->bts.size); |
| 7196 | buffer_xml_printf (buffer, " />\n"); |
| 7197 | break; |
| 7198 | |
| 7199 | case BTRACE_FORMAT_PT: |
| 7200 | buffer_xml_printf (buffer, "<pt"); |
| 7201 | buffer_xml_printf (buffer, " size=\"0x%x\"", conf->pt.size); |
| 7202 | buffer_xml_printf (buffer, "/>\n"); |
| 7203 | break; |
| 7204 | } |
| 7205 | } |
| 7206 | |
| 7207 | buffer_grow_str0 (buffer, "</btrace-conf>\n"); |
| 7208 | return 0; |
| 7209 | } |
| 7210 | #endif /* HAVE_LINUX_BTRACE */ |
| 7211 | |
| 7212 | /* See nat/linux-nat.h. */ |
| 7213 | |
| 7214 | ptid_t |
| 7215 | current_lwp_ptid (void) |
| 7216 | { |
| 7217 | return ptid_of (current_thread); |
| 7218 | } |
| 7219 | |
| 7220 | /* Implementation of the target_ops method "breakpoint_kind_from_pc". */ |
| 7221 | |
| 7222 | static int |
| 7223 | linux_breakpoint_kind_from_pc (CORE_ADDR *pcptr) |
| 7224 | { |
| 7225 | if (the_low_target.breakpoint_kind_from_pc != NULL) |
| 7226 | return (*the_low_target.breakpoint_kind_from_pc) (pcptr); |
| 7227 | else |
| 7228 | return default_breakpoint_kind_from_pc (pcptr); |
| 7229 | } |
| 7230 | |
| 7231 | /* Implementation of the target_ops method "sw_breakpoint_from_kind". */ |
| 7232 | |
| 7233 | static const gdb_byte * |
| 7234 | linux_sw_breakpoint_from_kind (int kind, int *size) |
| 7235 | { |
| 7236 | gdb_assert (the_low_target.sw_breakpoint_from_kind != NULL); |
| 7237 | |
| 7238 | return (*the_low_target.sw_breakpoint_from_kind) (kind, size); |
| 7239 | } |
| 7240 | |
| 7241 | /* Implementation of the target_ops method |
| 7242 | "breakpoint_kind_from_current_state". */ |
| 7243 | |
| 7244 | static int |
| 7245 | linux_breakpoint_kind_from_current_state (CORE_ADDR *pcptr) |
| 7246 | { |
| 7247 | if (the_low_target.breakpoint_kind_from_current_state != NULL) |
| 7248 | return (*the_low_target.breakpoint_kind_from_current_state) (pcptr); |
| 7249 | else |
| 7250 | return linux_breakpoint_kind_from_pc (pcptr); |
| 7251 | } |
| 7252 | |
| 7253 | /* Default implementation of linux_target_ops method "set_pc" for |
| 7254 | 32-bit pc register which is literally named "pc". */ |
| 7255 | |
| 7256 | void |
| 7257 | linux_set_pc_32bit (struct regcache *regcache, CORE_ADDR pc) |
| 7258 | { |
| 7259 | uint32_t newpc = pc; |
| 7260 | |
| 7261 | supply_register_by_name (regcache, "pc", &newpc); |
| 7262 | } |
| 7263 | |
| 7264 | /* Default implementation of linux_target_ops method "get_pc" for |
| 7265 | 32-bit pc register which is literally named "pc". */ |
| 7266 | |
| 7267 | CORE_ADDR |
| 7268 | linux_get_pc_32bit (struct regcache *regcache) |
| 7269 | { |
| 7270 | uint32_t pc; |
| 7271 | |
| 7272 | collect_register_by_name (regcache, "pc", &pc); |
| 7273 | if (debug_threads) |
| 7274 | debug_printf ("stop pc is 0x%" PRIx32 "\n", pc); |
| 7275 | return pc; |
| 7276 | } |
| 7277 | |
| 7278 | /* Default implementation of linux_target_ops method "set_pc" for |
| 7279 | 64-bit pc register which is literally named "pc". */ |
| 7280 | |
| 7281 | void |
| 7282 | linux_set_pc_64bit (struct regcache *regcache, CORE_ADDR pc) |
| 7283 | { |
| 7284 | uint64_t newpc = pc; |
| 7285 | |
| 7286 | supply_register_by_name (regcache, "pc", &newpc); |
| 7287 | } |
| 7288 | |
| 7289 | /* Default implementation of linux_target_ops method "get_pc" for |
| 7290 | 64-bit pc register which is literally named "pc". */ |
| 7291 | |
| 7292 | CORE_ADDR |
| 7293 | linux_get_pc_64bit (struct regcache *regcache) |
| 7294 | { |
| 7295 | uint64_t pc; |
| 7296 | |
| 7297 | collect_register_by_name (regcache, "pc", &pc); |
| 7298 | if (debug_threads) |
| 7299 | debug_printf ("stop pc is 0x%" PRIx64 "\n", pc); |
| 7300 | return pc; |
| 7301 | } |
| 7302 | |
| 7303 | /* See linux-low.h. */ |
| 7304 | |
| 7305 | int |
| 7306 | linux_get_auxv (int wordsize, CORE_ADDR match, CORE_ADDR *valp) |
| 7307 | { |
| 7308 | gdb_byte *data = (gdb_byte *) alloca (2 * wordsize); |
| 7309 | int offset = 0; |
| 7310 | |
| 7311 | gdb_assert (wordsize == 4 || wordsize == 8); |
| 7312 | |
| 7313 | while ((*the_target->read_auxv) (offset, data, 2 * wordsize) == 2 * wordsize) |
| 7314 | { |
| 7315 | if (wordsize == 4) |
| 7316 | { |
| 7317 | uint32_t *data_p = (uint32_t *) data; |
| 7318 | if (data_p[0] == match) |
| 7319 | { |
| 7320 | *valp = data_p[1]; |
| 7321 | return 1; |
| 7322 | } |
| 7323 | } |
| 7324 | else |
| 7325 | { |
| 7326 | uint64_t *data_p = (uint64_t *) data; |
| 7327 | if (data_p[0] == match) |
| 7328 | { |
| 7329 | *valp = data_p[1]; |
| 7330 | return 1; |
| 7331 | } |
| 7332 | } |
| 7333 | |
| 7334 | offset += 2 * wordsize; |
| 7335 | } |
| 7336 | |
| 7337 | return 0; |
| 7338 | } |
| 7339 | |
| 7340 | /* See linux-low.h. */ |
| 7341 | |
| 7342 | CORE_ADDR |
| 7343 | linux_get_hwcap (int wordsize) |
| 7344 | { |
| 7345 | CORE_ADDR hwcap = 0; |
| 7346 | linux_get_auxv (wordsize, AT_HWCAP, &hwcap); |
| 7347 | return hwcap; |
| 7348 | } |
| 7349 | |
| 7350 | /* See linux-low.h. */ |
| 7351 | |
| 7352 | CORE_ADDR |
| 7353 | linux_get_hwcap2 (int wordsize) |
| 7354 | { |
| 7355 | CORE_ADDR hwcap2 = 0; |
| 7356 | linux_get_auxv (wordsize, AT_HWCAP2, &hwcap2); |
| 7357 | return hwcap2; |
| 7358 | } |
| 7359 | |
| 7360 | static struct target_ops linux_target_ops = { |
| 7361 | linux_create_inferior, |
| 7362 | linux_post_create_inferior, |
| 7363 | linux_attach, |
| 7364 | linux_kill, |
| 7365 | linux_detach, |
| 7366 | linux_mourn, |
| 7367 | linux_join, |
| 7368 | linux_thread_alive, |
| 7369 | linux_resume, |
| 7370 | linux_wait, |
| 7371 | linux_fetch_registers, |
| 7372 | linux_store_registers, |
| 7373 | linux_prepare_to_access_memory, |
| 7374 | linux_done_accessing_memory, |
| 7375 | linux_read_memory, |
| 7376 | linux_write_memory, |
| 7377 | linux_look_up_symbols, |
| 7378 | linux_request_interrupt, |
| 7379 | linux_read_auxv, |
| 7380 | linux_supports_z_point_type, |
| 7381 | linux_insert_point, |
| 7382 | linux_remove_point, |
| 7383 | linux_stopped_by_sw_breakpoint, |
| 7384 | linux_supports_stopped_by_sw_breakpoint, |
| 7385 | linux_stopped_by_hw_breakpoint, |
| 7386 | linux_supports_stopped_by_hw_breakpoint, |
| 7387 | linux_supports_hardware_single_step, |
| 7388 | linux_stopped_by_watchpoint, |
| 7389 | linux_stopped_data_address, |
| 7390 | #if defined(__UCLIBC__) && defined(HAS_NOMMU) \ |
| 7391 | && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \ |
| 7392 | && defined(PT_TEXT_END_ADDR) |
| 7393 | linux_read_offsets, |
| 7394 | #else |
| 7395 | NULL, |
| 7396 | #endif |
| 7397 | #ifdef USE_THREAD_DB |
| 7398 | thread_db_get_tls_address, |
| 7399 | #else |
| 7400 | NULL, |
| 7401 | #endif |
| 7402 | hostio_last_error_from_errno, |
| 7403 | linux_qxfer_osdata, |
| 7404 | linux_xfer_siginfo, |
| 7405 | linux_supports_non_stop, |
| 7406 | linux_async, |
| 7407 | linux_start_non_stop, |
| 7408 | linux_supports_multi_process, |
| 7409 | linux_supports_fork_events, |
| 7410 | linux_supports_vfork_events, |
| 7411 | linux_supports_exec_events, |
| 7412 | linux_handle_new_gdb_connection, |
| 7413 | #ifdef USE_THREAD_DB |
| 7414 | thread_db_handle_monitor_command, |
| 7415 | #else |
| 7416 | NULL, |
| 7417 | #endif |
| 7418 | linux_common_core_of_thread, |
| 7419 | linux_read_loadmap, |
| 7420 | linux_process_qsupported, |
| 7421 | linux_supports_tracepoints, |
| 7422 | linux_read_pc, |
| 7423 | linux_write_pc, |
| 7424 | linux_thread_stopped, |
| 7425 | NULL, |
| 7426 | linux_pause_all, |
| 7427 | linux_unpause_all, |
| 7428 | linux_stabilize_threads, |
| 7429 | linux_install_fast_tracepoint_jump_pad, |
| 7430 | linux_emit_ops, |
| 7431 | linux_supports_disable_randomization, |
| 7432 | linux_get_min_fast_tracepoint_insn_len, |
| 7433 | linux_qxfer_libraries_svr4, |
| 7434 | linux_supports_agent, |
| 7435 | #ifdef HAVE_LINUX_BTRACE |
| 7436 | linux_enable_btrace, |
| 7437 | linux_low_disable_btrace, |
| 7438 | linux_low_read_btrace, |
| 7439 | linux_low_btrace_conf, |
| 7440 | #else |
| 7441 | NULL, |
| 7442 | NULL, |
| 7443 | NULL, |
| 7444 | NULL, |
| 7445 | #endif |
| 7446 | linux_supports_range_stepping, |
| 7447 | linux_proc_pid_to_exec_file, |
| 7448 | linux_mntns_open_cloexec, |
| 7449 | linux_mntns_unlink, |
| 7450 | linux_mntns_readlink, |
| 7451 | linux_breakpoint_kind_from_pc, |
| 7452 | linux_sw_breakpoint_from_kind, |
| 7453 | linux_proc_tid_get_name, |
| 7454 | linux_breakpoint_kind_from_current_state, |
| 7455 | linux_supports_software_single_step, |
| 7456 | linux_supports_catch_syscall, |
| 7457 | linux_get_ipa_tdesc_idx, |
| 7458 | #if USE_THREAD_DB |
| 7459 | thread_db_thread_handle, |
| 7460 | #else |
| 7461 | NULL, |
| 7462 | #endif |
| 7463 | }; |
| 7464 | |
| 7465 | #ifdef HAVE_LINUX_REGSETS |
| 7466 | void |
| 7467 | initialize_regsets_info (struct regsets_info *info) |
| 7468 | { |
| 7469 | for (info->num_regsets = 0; |
| 7470 | info->regsets[info->num_regsets].size >= 0; |
| 7471 | info->num_regsets++) |
| 7472 | ; |
| 7473 | } |
| 7474 | #endif |
| 7475 | |
| 7476 | void |
| 7477 | initialize_low (void) |
| 7478 | { |
| 7479 | struct sigaction sigchld_action; |
| 7480 | |
| 7481 | memset (&sigchld_action, 0, sizeof (sigchld_action)); |
| 7482 | set_target_ops (&linux_target_ops); |
| 7483 | |
| 7484 | linux_ptrace_init_warnings (); |
| 7485 | linux_proc_init_warnings (); |
| 7486 | |
| 7487 | sigchld_action.sa_handler = sigchld_handler; |
| 7488 | sigemptyset (&sigchld_action.sa_mask); |
| 7489 | sigchld_action.sa_flags = SA_RESTART; |
| 7490 | sigaction (SIGCHLD, &sigchld_action, NULL); |
| 7491 | |
| 7492 | initialize_low_arch (); |
| 7493 | |
| 7494 | linux_check_ptrace_features (); |
| 7495 | } |