| 1 | /* Low level interface to ptrace, for the remote server for GDB. |
| 2 | Copyright (C) 1995-2020 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 <inttypes.h> |
| 49 | #include "gdbsupport/common-inferior.h" |
| 50 | #include "nat/fork-inferior.h" |
| 51 | #include "gdbsupport/environ.h" |
| 52 | #include "gdbsupport/gdb-sigmask.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 | #if (defined(__UCLIBC__) \ |
| 103 | && defined(HAS_NOMMU) \ |
| 104 | && defined(PT_TEXT_ADDR) \ |
| 105 | && defined(PT_DATA_ADDR) \ |
| 106 | && defined(PT_TEXT_END_ADDR)) |
| 107 | #define SUPPORTS_READ_OFFSETS |
| 108 | #endif |
| 109 | |
| 110 | #ifdef HAVE_LINUX_BTRACE |
| 111 | # include "nat/linux-btrace.h" |
| 112 | # include "gdbsupport/btrace-common.h" |
| 113 | #endif |
| 114 | |
| 115 | #ifndef HAVE_ELF32_AUXV_T |
| 116 | /* Copied from glibc's elf.h. */ |
| 117 | typedef struct |
| 118 | { |
| 119 | uint32_t a_type; /* Entry type */ |
| 120 | union |
| 121 | { |
| 122 | uint32_t a_val; /* Integer value */ |
| 123 | /* We use to have pointer elements added here. We cannot do that, |
| 124 | though, since it does not work when using 32-bit definitions |
| 125 | on 64-bit platforms and vice versa. */ |
| 126 | } a_un; |
| 127 | } Elf32_auxv_t; |
| 128 | #endif |
| 129 | |
| 130 | #ifndef HAVE_ELF64_AUXV_T |
| 131 | /* Copied from glibc's elf.h. */ |
| 132 | typedef struct |
| 133 | { |
| 134 | uint64_t a_type; /* Entry type */ |
| 135 | union |
| 136 | { |
| 137 | uint64_t a_val; /* Integer value */ |
| 138 | /* We use to have pointer elements added here. We cannot do that, |
| 139 | though, since it does not work when using 32-bit definitions |
| 140 | on 64-bit platforms and vice versa. */ |
| 141 | } a_un; |
| 142 | } Elf64_auxv_t; |
| 143 | #endif |
| 144 | |
| 145 | /* Does the current host support PTRACE_GETREGSET? */ |
| 146 | int have_ptrace_getregset = -1; |
| 147 | |
| 148 | /* LWP accessors. */ |
| 149 | |
| 150 | /* See nat/linux-nat.h. */ |
| 151 | |
| 152 | ptid_t |
| 153 | ptid_of_lwp (struct lwp_info *lwp) |
| 154 | { |
| 155 | return ptid_of (get_lwp_thread (lwp)); |
| 156 | } |
| 157 | |
| 158 | /* See nat/linux-nat.h. */ |
| 159 | |
| 160 | void |
| 161 | lwp_set_arch_private_info (struct lwp_info *lwp, |
| 162 | struct arch_lwp_info *info) |
| 163 | { |
| 164 | lwp->arch_private = info; |
| 165 | } |
| 166 | |
| 167 | /* See nat/linux-nat.h. */ |
| 168 | |
| 169 | struct arch_lwp_info * |
| 170 | lwp_arch_private_info (struct lwp_info *lwp) |
| 171 | { |
| 172 | return lwp->arch_private; |
| 173 | } |
| 174 | |
| 175 | /* See nat/linux-nat.h. */ |
| 176 | |
| 177 | int |
| 178 | lwp_is_stopped (struct lwp_info *lwp) |
| 179 | { |
| 180 | return lwp->stopped; |
| 181 | } |
| 182 | |
| 183 | /* See nat/linux-nat.h. */ |
| 184 | |
| 185 | enum target_stop_reason |
| 186 | lwp_stop_reason (struct lwp_info *lwp) |
| 187 | { |
| 188 | return lwp->stop_reason; |
| 189 | } |
| 190 | |
| 191 | /* See nat/linux-nat.h. */ |
| 192 | |
| 193 | int |
| 194 | lwp_is_stepping (struct lwp_info *lwp) |
| 195 | { |
| 196 | return lwp->stepping; |
| 197 | } |
| 198 | |
| 199 | /* A list of all unknown processes which receive stop signals. Some |
| 200 | other process will presumably claim each of these as forked |
| 201 | children momentarily. */ |
| 202 | |
| 203 | struct simple_pid_list |
| 204 | { |
| 205 | /* The process ID. */ |
| 206 | int pid; |
| 207 | |
| 208 | /* The status as reported by waitpid. */ |
| 209 | int status; |
| 210 | |
| 211 | /* Next in chain. */ |
| 212 | struct simple_pid_list *next; |
| 213 | }; |
| 214 | struct simple_pid_list *stopped_pids; |
| 215 | |
| 216 | /* Trivial list manipulation functions to keep track of a list of new |
| 217 | stopped processes. */ |
| 218 | |
| 219 | static void |
| 220 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
| 221 | { |
| 222 | struct simple_pid_list *new_pid = XNEW (struct simple_pid_list); |
| 223 | |
| 224 | new_pid->pid = pid; |
| 225 | new_pid->status = status; |
| 226 | new_pid->next = *listp; |
| 227 | *listp = new_pid; |
| 228 | } |
| 229 | |
| 230 | static int |
| 231 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
| 232 | { |
| 233 | struct simple_pid_list **p; |
| 234 | |
| 235 | for (p = listp; *p != NULL; p = &(*p)->next) |
| 236 | if ((*p)->pid == pid) |
| 237 | { |
| 238 | struct simple_pid_list *next = (*p)->next; |
| 239 | |
| 240 | *statusp = (*p)->status; |
| 241 | xfree (*p); |
| 242 | *p = next; |
| 243 | return 1; |
| 244 | } |
| 245 | return 0; |
| 246 | } |
| 247 | |
| 248 | enum stopping_threads_kind |
| 249 | { |
| 250 | /* Not stopping threads presently. */ |
| 251 | NOT_STOPPING_THREADS, |
| 252 | |
| 253 | /* Stopping threads. */ |
| 254 | STOPPING_THREADS, |
| 255 | |
| 256 | /* Stopping and suspending threads. */ |
| 257 | STOPPING_AND_SUSPENDING_THREADS |
| 258 | }; |
| 259 | |
| 260 | /* This is set while stop_all_lwps is in effect. */ |
| 261 | enum stopping_threads_kind stopping_threads = NOT_STOPPING_THREADS; |
| 262 | |
| 263 | /* FIXME make into a target method? */ |
| 264 | int using_threads = 1; |
| 265 | |
| 266 | /* True if we're presently stabilizing threads (moving them out of |
| 267 | jump pads). */ |
| 268 | static int stabilizing_threads; |
| 269 | |
| 270 | static void unsuspend_all_lwps (struct lwp_info *except); |
| 271 | static struct lwp_info *add_lwp (ptid_t ptid); |
| 272 | static void mark_lwp_dead (struct lwp_info *lwp, int wstat); |
| 273 | static int lwp_is_marked_dead (struct lwp_info *lwp); |
| 274 | static int finish_step_over (struct lwp_info *lwp); |
| 275 | static int kill_lwp (unsigned long lwpid, int signo); |
| 276 | static void enqueue_pending_signal (struct lwp_info *lwp, int signal, siginfo_t *info); |
| 277 | static int linux_low_ptrace_options (int attached); |
| 278 | static int check_ptrace_stopped_lwp_gone (struct lwp_info *lp); |
| 279 | |
| 280 | /* When the event-loop is doing a step-over, this points at the thread |
| 281 | being stepped. */ |
| 282 | ptid_t step_over_bkpt; |
| 283 | |
| 284 | /* True if the low target can hardware single-step. */ |
| 285 | |
| 286 | static int |
| 287 | can_hardware_single_step (void) |
| 288 | { |
| 289 | if (the_low_target.supports_hardware_single_step != NULL) |
| 290 | return the_low_target.supports_hardware_single_step (); |
| 291 | else |
| 292 | return 0; |
| 293 | } |
| 294 | |
| 295 | bool |
| 296 | linux_process_target::low_supports_breakpoints () |
| 297 | { |
| 298 | return false; |
| 299 | } |
| 300 | |
| 301 | CORE_ADDR |
| 302 | linux_process_target::low_get_pc (regcache *regcache) |
| 303 | { |
| 304 | return 0; |
| 305 | } |
| 306 | |
| 307 | void |
| 308 | linux_process_target::low_set_pc (regcache *regcache, CORE_ADDR newpc) |
| 309 | { |
| 310 | gdb_assert_not_reached ("linux target op low_set_pc is not implemented"); |
| 311 | } |
| 312 | |
| 313 | std::vector<CORE_ADDR> |
| 314 | linux_process_target::low_get_next_pcs (regcache *regcache) |
| 315 | { |
| 316 | gdb_assert_not_reached ("linux target op low_get_next_pcs is not " |
| 317 | "implemented"); |
| 318 | } |
| 319 | |
| 320 | int |
| 321 | linux_process_target::low_decr_pc_after_break () |
| 322 | { |
| 323 | return 0; |
| 324 | } |
| 325 | |
| 326 | /* Returns true if this target can support fast tracepoints. This |
| 327 | does not mean that the in-process agent has been loaded in the |
| 328 | inferior. */ |
| 329 | |
| 330 | static int |
| 331 | supports_fast_tracepoints (void) |
| 332 | { |
| 333 | return the_low_target.install_fast_tracepoint_jump_pad != NULL; |
| 334 | } |
| 335 | |
| 336 | /* True if LWP is stopped in its stepping range. */ |
| 337 | |
| 338 | static int |
| 339 | lwp_in_step_range (struct lwp_info *lwp) |
| 340 | { |
| 341 | CORE_ADDR pc = lwp->stop_pc; |
| 342 | |
| 343 | return (pc >= lwp->step_range_start && pc < lwp->step_range_end); |
| 344 | } |
| 345 | |
| 346 | struct pending_signals |
| 347 | { |
| 348 | int signal; |
| 349 | siginfo_t info; |
| 350 | struct pending_signals *prev; |
| 351 | }; |
| 352 | |
| 353 | /* The read/write ends of the pipe registered as waitable file in the |
| 354 | event loop. */ |
| 355 | static int linux_event_pipe[2] = { -1, -1 }; |
| 356 | |
| 357 | /* True if we're currently in async mode. */ |
| 358 | #define target_is_async_p() (linux_event_pipe[0] != -1) |
| 359 | |
| 360 | static void send_sigstop (struct lwp_info *lwp); |
| 361 | |
| 362 | /* Return non-zero if HEADER is a 64-bit ELF file. */ |
| 363 | |
| 364 | static int |
| 365 | elf_64_header_p (const Elf64_Ehdr *header, unsigned int *machine) |
| 366 | { |
| 367 | if (header->e_ident[EI_MAG0] == ELFMAG0 |
| 368 | && header->e_ident[EI_MAG1] == ELFMAG1 |
| 369 | && header->e_ident[EI_MAG2] == ELFMAG2 |
| 370 | && header->e_ident[EI_MAG3] == ELFMAG3) |
| 371 | { |
| 372 | *machine = header->e_machine; |
| 373 | return header->e_ident[EI_CLASS] == ELFCLASS64; |
| 374 | |
| 375 | } |
| 376 | *machine = EM_NONE; |
| 377 | return -1; |
| 378 | } |
| 379 | |
| 380 | /* Return non-zero if FILE is a 64-bit ELF file, |
| 381 | zero if the file is not a 64-bit ELF file, |
| 382 | and -1 if the file is not accessible or doesn't exist. */ |
| 383 | |
| 384 | static int |
| 385 | elf_64_file_p (const char *file, unsigned int *machine) |
| 386 | { |
| 387 | Elf64_Ehdr header; |
| 388 | int fd; |
| 389 | |
| 390 | fd = open (file, O_RDONLY); |
| 391 | if (fd < 0) |
| 392 | return -1; |
| 393 | |
| 394 | if (read (fd, &header, sizeof (header)) != sizeof (header)) |
| 395 | { |
| 396 | close (fd); |
| 397 | return 0; |
| 398 | } |
| 399 | close (fd); |
| 400 | |
| 401 | return elf_64_header_p (&header, machine); |
| 402 | } |
| 403 | |
| 404 | /* Accepts an integer PID; Returns true if the executable PID is |
| 405 | running is a 64-bit ELF file.. */ |
| 406 | |
| 407 | int |
| 408 | linux_pid_exe_is_elf_64_file (int pid, unsigned int *machine) |
| 409 | { |
| 410 | char file[PATH_MAX]; |
| 411 | |
| 412 | sprintf (file, "/proc/%d/exe", pid); |
| 413 | return elf_64_file_p (file, machine); |
| 414 | } |
| 415 | |
| 416 | static void |
| 417 | delete_lwp (struct lwp_info *lwp) |
| 418 | { |
| 419 | struct thread_info *thr = get_lwp_thread (lwp); |
| 420 | |
| 421 | if (debug_threads) |
| 422 | debug_printf ("deleting %ld\n", lwpid_of (thr)); |
| 423 | |
| 424 | remove_thread (thr); |
| 425 | |
| 426 | if (the_low_target.delete_thread != NULL) |
| 427 | the_low_target.delete_thread (lwp->arch_private); |
| 428 | else |
| 429 | gdb_assert (lwp->arch_private == NULL); |
| 430 | |
| 431 | free (lwp); |
| 432 | } |
| 433 | |
| 434 | /* Add a process to the common process list, and set its private |
| 435 | data. */ |
| 436 | |
| 437 | static struct process_info * |
| 438 | linux_add_process (int pid, int attached) |
| 439 | { |
| 440 | struct process_info *proc; |
| 441 | |
| 442 | proc = add_process (pid, attached); |
| 443 | proc->priv = XCNEW (struct process_info_private); |
| 444 | |
| 445 | if (the_low_target.new_process != NULL) |
| 446 | proc->priv->arch_private = the_low_target.new_process (); |
| 447 | |
| 448 | return proc; |
| 449 | } |
| 450 | |
| 451 | void |
| 452 | linux_process_target::arch_setup_thread (thread_info *thread) |
| 453 | { |
| 454 | struct thread_info *saved_thread; |
| 455 | |
| 456 | saved_thread = current_thread; |
| 457 | current_thread = thread; |
| 458 | |
| 459 | low_arch_setup (); |
| 460 | |
| 461 | current_thread = saved_thread; |
| 462 | } |
| 463 | |
| 464 | int |
| 465 | linux_process_target::handle_extended_wait (lwp_info **orig_event_lwp, |
| 466 | int wstat) |
| 467 | { |
| 468 | client_state &cs = get_client_state (); |
| 469 | struct lwp_info *event_lwp = *orig_event_lwp; |
| 470 | int event = linux_ptrace_get_extended_event (wstat); |
| 471 | struct thread_info *event_thr = get_lwp_thread (event_lwp); |
| 472 | struct lwp_info *new_lwp; |
| 473 | |
| 474 | gdb_assert (event_lwp->waitstatus.kind == TARGET_WAITKIND_IGNORE); |
| 475 | |
| 476 | /* All extended events we currently use are mid-syscall. Only |
| 477 | PTRACE_EVENT_STOP is delivered more like a signal-stop, but |
| 478 | you have to be using PTRACE_SEIZE to get that. */ |
| 479 | event_lwp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY; |
| 480 | |
| 481 | if ((event == PTRACE_EVENT_FORK) || (event == PTRACE_EVENT_VFORK) |
| 482 | || (event == PTRACE_EVENT_CLONE)) |
| 483 | { |
| 484 | ptid_t ptid; |
| 485 | unsigned long new_pid; |
| 486 | int ret, status; |
| 487 | |
| 488 | /* Get the pid of the new lwp. */ |
| 489 | ptrace (PTRACE_GETEVENTMSG, lwpid_of (event_thr), (PTRACE_TYPE_ARG3) 0, |
| 490 | &new_pid); |
| 491 | |
| 492 | /* If we haven't already seen the new PID stop, wait for it now. */ |
| 493 | if (!pull_pid_from_list (&stopped_pids, new_pid, &status)) |
| 494 | { |
| 495 | /* The new child has a pending SIGSTOP. We can't affect it until it |
| 496 | hits the SIGSTOP, but we're already attached. */ |
| 497 | |
| 498 | ret = my_waitpid (new_pid, &status, __WALL); |
| 499 | |
| 500 | if (ret == -1) |
| 501 | perror_with_name ("waiting for new child"); |
| 502 | else if (ret != new_pid) |
| 503 | warning ("wait returned unexpected PID %d", ret); |
| 504 | else if (!WIFSTOPPED (status)) |
| 505 | warning ("wait returned unexpected status 0x%x", status); |
| 506 | } |
| 507 | |
| 508 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) |
| 509 | { |
| 510 | struct process_info *parent_proc; |
| 511 | struct process_info *child_proc; |
| 512 | struct lwp_info *child_lwp; |
| 513 | struct thread_info *child_thr; |
| 514 | struct target_desc *tdesc; |
| 515 | |
| 516 | ptid = ptid_t (new_pid, new_pid, 0); |
| 517 | |
| 518 | if (debug_threads) |
| 519 | { |
| 520 | debug_printf ("HEW: Got fork event from LWP %ld, " |
| 521 | "new child is %d\n", |
| 522 | ptid_of (event_thr).lwp (), |
| 523 | ptid.pid ()); |
| 524 | } |
| 525 | |
| 526 | /* Add the new process to the tables and clone the breakpoint |
| 527 | lists of the parent. We need to do this even if the new process |
| 528 | will be detached, since we will need the process object and the |
| 529 | breakpoints to remove any breakpoints from memory when we |
| 530 | detach, and the client side will access registers. */ |
| 531 | child_proc = linux_add_process (new_pid, 0); |
| 532 | gdb_assert (child_proc != NULL); |
| 533 | child_lwp = add_lwp (ptid); |
| 534 | gdb_assert (child_lwp != NULL); |
| 535 | child_lwp->stopped = 1; |
| 536 | child_lwp->must_set_ptrace_flags = 1; |
| 537 | child_lwp->status_pending_p = 0; |
| 538 | child_thr = get_lwp_thread (child_lwp); |
| 539 | child_thr->last_resume_kind = resume_stop; |
| 540 | child_thr->last_status.kind = TARGET_WAITKIND_STOPPED; |
| 541 | |
| 542 | /* If we're suspending all threads, leave this one suspended |
| 543 | too. If the fork/clone parent is stepping over a breakpoint, |
| 544 | all other threads have been suspended already. Leave the |
| 545 | child suspended too. */ |
| 546 | if (stopping_threads == STOPPING_AND_SUSPENDING_THREADS |
| 547 | || event_lwp->bp_reinsert != 0) |
| 548 | { |
| 549 | if (debug_threads) |
| 550 | debug_printf ("HEW: leaving child suspended\n"); |
| 551 | child_lwp->suspended = 1; |
| 552 | } |
| 553 | |
| 554 | parent_proc = get_thread_process (event_thr); |
| 555 | child_proc->attached = parent_proc->attached; |
| 556 | |
| 557 | if (event_lwp->bp_reinsert != 0 |
| 558 | && supports_software_single_step () |
| 559 | && event == PTRACE_EVENT_VFORK) |
| 560 | { |
| 561 | /* If we leave single-step breakpoints there, child will |
| 562 | hit it, so uninsert single-step breakpoints from parent |
| 563 | (and child). Once vfork child is done, reinsert |
| 564 | them back to parent. */ |
| 565 | uninsert_single_step_breakpoints (event_thr); |
| 566 | } |
| 567 | |
| 568 | clone_all_breakpoints (child_thr, event_thr); |
| 569 | |
| 570 | tdesc = allocate_target_description (); |
| 571 | copy_target_description (tdesc, parent_proc->tdesc); |
| 572 | child_proc->tdesc = tdesc; |
| 573 | |
| 574 | /* Clone arch-specific process data. */ |
| 575 | if (the_low_target.new_fork != NULL) |
| 576 | the_low_target.new_fork (parent_proc, child_proc); |
| 577 | |
| 578 | /* Save fork info in the parent thread. */ |
| 579 | if (event == PTRACE_EVENT_FORK) |
| 580 | event_lwp->waitstatus.kind = TARGET_WAITKIND_FORKED; |
| 581 | else if (event == PTRACE_EVENT_VFORK) |
| 582 | event_lwp->waitstatus.kind = TARGET_WAITKIND_VFORKED; |
| 583 | |
| 584 | event_lwp->waitstatus.value.related_pid = ptid; |
| 585 | |
| 586 | /* The status_pending field contains bits denoting the |
| 587 | extended event, so when the pending event is handled, |
| 588 | the handler will look at lwp->waitstatus. */ |
| 589 | event_lwp->status_pending_p = 1; |
| 590 | event_lwp->status_pending = wstat; |
| 591 | |
| 592 | /* Link the threads until the parent event is passed on to |
| 593 | higher layers. */ |
| 594 | event_lwp->fork_relative = child_lwp; |
| 595 | child_lwp->fork_relative = event_lwp; |
| 596 | |
| 597 | /* If the parent thread is doing step-over with single-step |
| 598 | breakpoints, the list of single-step breakpoints are cloned |
| 599 | from the parent's. Remove them from the child process. |
| 600 | In case of vfork, we'll reinsert them back once vforked |
| 601 | child is done. */ |
| 602 | if (event_lwp->bp_reinsert != 0 |
| 603 | && supports_software_single_step ()) |
| 604 | { |
| 605 | /* The child process is forked and stopped, so it is safe |
| 606 | to access its memory without stopping all other threads |
| 607 | from other processes. */ |
| 608 | delete_single_step_breakpoints (child_thr); |
| 609 | |
| 610 | gdb_assert (has_single_step_breakpoints (event_thr)); |
| 611 | gdb_assert (!has_single_step_breakpoints (child_thr)); |
| 612 | } |
| 613 | |
| 614 | /* Report the event. */ |
| 615 | return 0; |
| 616 | } |
| 617 | |
| 618 | if (debug_threads) |
| 619 | debug_printf ("HEW: Got clone event " |
| 620 | "from LWP %ld, new child is LWP %ld\n", |
| 621 | lwpid_of (event_thr), new_pid); |
| 622 | |
| 623 | ptid = ptid_t (pid_of (event_thr), new_pid, 0); |
| 624 | new_lwp = add_lwp (ptid); |
| 625 | |
| 626 | /* Either we're going to immediately resume the new thread |
| 627 | or leave it stopped. resume_one_lwp is a nop if it |
| 628 | thinks the thread is currently running, so set this first |
| 629 | before calling resume_one_lwp. */ |
| 630 | new_lwp->stopped = 1; |
| 631 | |
| 632 | /* If we're suspending all threads, leave this one suspended |
| 633 | too. If the fork/clone parent is stepping over a breakpoint, |
| 634 | all other threads have been suspended already. Leave the |
| 635 | child suspended too. */ |
| 636 | if (stopping_threads == STOPPING_AND_SUSPENDING_THREADS |
| 637 | || event_lwp->bp_reinsert != 0) |
| 638 | new_lwp->suspended = 1; |
| 639 | |
| 640 | /* Normally we will get the pending SIGSTOP. But in some cases |
| 641 | we might get another signal delivered to the group first. |
| 642 | If we do get another signal, be sure not to lose it. */ |
| 643 | if (WSTOPSIG (status) != SIGSTOP) |
| 644 | { |
| 645 | new_lwp->stop_expected = 1; |
| 646 | new_lwp->status_pending_p = 1; |
| 647 | new_lwp->status_pending = status; |
| 648 | } |
| 649 | else if (cs.report_thread_events) |
| 650 | { |
| 651 | new_lwp->waitstatus.kind = TARGET_WAITKIND_THREAD_CREATED; |
| 652 | new_lwp->status_pending_p = 1; |
| 653 | new_lwp->status_pending = status; |
| 654 | } |
| 655 | |
| 656 | #ifdef USE_THREAD_DB |
| 657 | thread_db_notice_clone (event_thr, ptid); |
| 658 | #endif |
| 659 | |
| 660 | /* Don't report the event. */ |
| 661 | return 1; |
| 662 | } |
| 663 | else if (event == PTRACE_EVENT_VFORK_DONE) |
| 664 | { |
| 665 | event_lwp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE; |
| 666 | |
| 667 | if (event_lwp->bp_reinsert != 0 && supports_software_single_step ()) |
| 668 | { |
| 669 | reinsert_single_step_breakpoints (event_thr); |
| 670 | |
| 671 | gdb_assert (has_single_step_breakpoints (event_thr)); |
| 672 | } |
| 673 | |
| 674 | /* Report the event. */ |
| 675 | return 0; |
| 676 | } |
| 677 | else if (event == PTRACE_EVENT_EXEC && cs.report_exec_events) |
| 678 | { |
| 679 | struct process_info *proc; |
| 680 | std::vector<int> syscalls_to_catch; |
| 681 | ptid_t event_ptid; |
| 682 | pid_t event_pid; |
| 683 | |
| 684 | if (debug_threads) |
| 685 | { |
| 686 | debug_printf ("HEW: Got exec event from LWP %ld\n", |
| 687 | lwpid_of (event_thr)); |
| 688 | } |
| 689 | |
| 690 | /* Get the event ptid. */ |
| 691 | event_ptid = ptid_of (event_thr); |
| 692 | event_pid = event_ptid.pid (); |
| 693 | |
| 694 | /* Save the syscall list from the execing process. */ |
| 695 | proc = get_thread_process (event_thr); |
| 696 | syscalls_to_catch = std::move (proc->syscalls_to_catch); |
| 697 | |
| 698 | /* Delete the execing process and all its threads. */ |
| 699 | mourn (proc); |
| 700 | current_thread = NULL; |
| 701 | |
| 702 | /* Create a new process/lwp/thread. */ |
| 703 | proc = linux_add_process (event_pid, 0); |
| 704 | event_lwp = add_lwp (event_ptid); |
| 705 | event_thr = get_lwp_thread (event_lwp); |
| 706 | gdb_assert (current_thread == event_thr); |
| 707 | arch_setup_thread (event_thr); |
| 708 | |
| 709 | /* Set the event status. */ |
| 710 | event_lwp->waitstatus.kind = TARGET_WAITKIND_EXECD; |
| 711 | event_lwp->waitstatus.value.execd_pathname |
| 712 | = xstrdup (linux_proc_pid_to_exec_file (lwpid_of (event_thr))); |
| 713 | |
| 714 | /* Mark the exec status as pending. */ |
| 715 | event_lwp->stopped = 1; |
| 716 | event_lwp->status_pending_p = 1; |
| 717 | event_lwp->status_pending = wstat; |
| 718 | event_thr->last_resume_kind = resume_continue; |
| 719 | event_thr->last_status.kind = TARGET_WAITKIND_IGNORE; |
| 720 | |
| 721 | /* Update syscall state in the new lwp, effectively mid-syscall too. */ |
| 722 | event_lwp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY; |
| 723 | |
| 724 | /* Restore the list to catch. Don't rely on the client, which is free |
| 725 | to avoid sending a new list when the architecture doesn't change. |
| 726 | Also, for ANY_SYSCALL, the architecture doesn't really matter. */ |
| 727 | proc->syscalls_to_catch = std::move (syscalls_to_catch); |
| 728 | |
| 729 | /* Report the event. */ |
| 730 | *orig_event_lwp = event_lwp; |
| 731 | return 0; |
| 732 | } |
| 733 | |
| 734 | internal_error (__FILE__, __LINE__, _("unknown ptrace event %d"), event); |
| 735 | } |
| 736 | |
| 737 | CORE_ADDR |
| 738 | linux_process_target::get_pc (lwp_info *lwp) |
| 739 | { |
| 740 | struct thread_info *saved_thread; |
| 741 | struct regcache *regcache; |
| 742 | CORE_ADDR pc; |
| 743 | |
| 744 | if (!low_supports_breakpoints ()) |
| 745 | return 0; |
| 746 | |
| 747 | saved_thread = current_thread; |
| 748 | current_thread = get_lwp_thread (lwp); |
| 749 | |
| 750 | regcache = get_thread_regcache (current_thread, 1); |
| 751 | pc = low_get_pc (regcache); |
| 752 | |
| 753 | if (debug_threads) |
| 754 | debug_printf ("pc is 0x%lx\n", (long) pc); |
| 755 | |
| 756 | current_thread = saved_thread; |
| 757 | return pc; |
| 758 | } |
| 759 | |
| 760 | /* This function should only be called if LWP got a SYSCALL_SIGTRAP. |
| 761 | Fill *SYSNO with the syscall nr trapped. */ |
| 762 | |
| 763 | static void |
| 764 | get_syscall_trapinfo (struct lwp_info *lwp, int *sysno) |
| 765 | { |
| 766 | struct thread_info *saved_thread; |
| 767 | struct regcache *regcache; |
| 768 | |
| 769 | if (the_low_target.get_syscall_trapinfo == NULL) |
| 770 | { |
| 771 | /* If we cannot get the syscall trapinfo, report an unknown |
| 772 | system call number. */ |
| 773 | *sysno = UNKNOWN_SYSCALL; |
| 774 | return; |
| 775 | } |
| 776 | |
| 777 | saved_thread = current_thread; |
| 778 | current_thread = get_lwp_thread (lwp); |
| 779 | |
| 780 | regcache = get_thread_regcache (current_thread, 1); |
| 781 | (*the_low_target.get_syscall_trapinfo) (regcache, sysno); |
| 782 | |
| 783 | if (debug_threads) |
| 784 | debug_printf ("get_syscall_trapinfo sysno %d\n", *sysno); |
| 785 | |
| 786 | current_thread = saved_thread; |
| 787 | } |
| 788 | |
| 789 | static int check_stopped_by_watchpoint (struct lwp_info *child); |
| 790 | |
| 791 | bool |
| 792 | linux_process_target::save_stop_reason (lwp_info *lwp) |
| 793 | { |
| 794 | CORE_ADDR pc; |
| 795 | CORE_ADDR sw_breakpoint_pc; |
| 796 | struct thread_info *saved_thread; |
| 797 | #if USE_SIGTRAP_SIGINFO |
| 798 | siginfo_t siginfo; |
| 799 | #endif |
| 800 | |
| 801 | if (!low_supports_breakpoints ()) |
| 802 | return false; |
| 803 | |
| 804 | pc = get_pc (lwp); |
| 805 | sw_breakpoint_pc = pc - low_decr_pc_after_break (); |
| 806 | |
| 807 | /* breakpoint_at reads from the current thread. */ |
| 808 | saved_thread = current_thread; |
| 809 | current_thread = get_lwp_thread (lwp); |
| 810 | |
| 811 | #if USE_SIGTRAP_SIGINFO |
| 812 | if (ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread), |
| 813 | (PTRACE_TYPE_ARG3) 0, &siginfo) == 0) |
| 814 | { |
| 815 | if (siginfo.si_signo == SIGTRAP) |
| 816 | { |
| 817 | if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code) |
| 818 | && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) |
| 819 | { |
| 820 | /* The si_code is ambiguous on this arch -- check debug |
| 821 | registers. */ |
| 822 | if (!check_stopped_by_watchpoint (lwp)) |
| 823 | lwp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
| 824 | } |
| 825 | else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)) |
| 826 | { |
| 827 | /* If we determine the LWP stopped for a SW breakpoint, |
| 828 | trust it. Particularly don't check watchpoint |
| 829 | registers, because at least on s390, we'd find |
| 830 | stopped-by-watchpoint as long as there's a watchpoint |
| 831 | set. */ |
| 832 | lwp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
| 833 | } |
| 834 | else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) |
| 835 | { |
| 836 | /* This can indicate either a hardware breakpoint or |
| 837 | hardware watchpoint. Check debug registers. */ |
| 838 | if (!check_stopped_by_watchpoint (lwp)) |
| 839 | lwp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; |
| 840 | } |
| 841 | else if (siginfo.si_code == TRAP_TRACE) |
| 842 | { |
| 843 | /* We may have single stepped an instruction that |
| 844 | triggered a watchpoint. In that case, on some |
| 845 | architectures (such as x86), instead of TRAP_HWBKPT, |
| 846 | si_code indicates TRAP_TRACE, and we need to check |
| 847 | the debug registers separately. */ |
| 848 | if (!check_stopped_by_watchpoint (lwp)) |
| 849 | lwp->stop_reason = TARGET_STOPPED_BY_SINGLE_STEP; |
| 850 | } |
| 851 | } |
| 852 | } |
| 853 | #else |
| 854 | /* We may have just stepped a breakpoint instruction. E.g., in |
| 855 | non-stop mode, GDB first tells the thread A to step a range, and |
| 856 | then the user inserts a breakpoint inside the range. In that |
| 857 | case we need to report the breakpoint PC. */ |
| 858 | if ((!lwp->stepping || lwp->stop_pc == sw_breakpoint_pc) |
| 859 | && low_breakpoint_at (sw_breakpoint_pc)) |
| 860 | lwp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
| 861 | |
| 862 | if (hardware_breakpoint_inserted_here (pc)) |
| 863 | lwp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; |
| 864 | |
| 865 | if (lwp->stop_reason == TARGET_STOPPED_BY_NO_REASON) |
| 866 | check_stopped_by_watchpoint (lwp); |
| 867 | #endif |
| 868 | |
| 869 | if (lwp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT) |
| 870 | { |
| 871 | if (debug_threads) |
| 872 | { |
| 873 | struct thread_info *thr = get_lwp_thread (lwp); |
| 874 | |
| 875 | debug_printf ("CSBB: %s stopped by software breakpoint\n", |
| 876 | target_pid_to_str (ptid_of (thr))); |
| 877 | } |
| 878 | |
| 879 | /* Back up the PC if necessary. */ |
| 880 | if (pc != sw_breakpoint_pc) |
| 881 | { |
| 882 | struct regcache *regcache |
| 883 | = get_thread_regcache (current_thread, 1); |
| 884 | low_set_pc (regcache, sw_breakpoint_pc); |
| 885 | } |
| 886 | |
| 887 | /* Update this so we record the correct stop PC below. */ |
| 888 | pc = sw_breakpoint_pc; |
| 889 | } |
| 890 | else if (lwp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) |
| 891 | { |
| 892 | if (debug_threads) |
| 893 | { |
| 894 | struct thread_info *thr = get_lwp_thread (lwp); |
| 895 | |
| 896 | debug_printf ("CSBB: %s stopped by hardware breakpoint\n", |
| 897 | target_pid_to_str (ptid_of (thr))); |
| 898 | } |
| 899 | } |
| 900 | else if (lwp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT) |
| 901 | { |
| 902 | if (debug_threads) |
| 903 | { |
| 904 | struct thread_info *thr = get_lwp_thread (lwp); |
| 905 | |
| 906 | debug_printf ("CSBB: %s stopped by hardware watchpoint\n", |
| 907 | target_pid_to_str (ptid_of (thr))); |
| 908 | } |
| 909 | } |
| 910 | else if (lwp->stop_reason == TARGET_STOPPED_BY_SINGLE_STEP) |
| 911 | { |
| 912 | if (debug_threads) |
| 913 | { |
| 914 | struct thread_info *thr = get_lwp_thread (lwp); |
| 915 | |
| 916 | debug_printf ("CSBB: %s stopped by trace\n", |
| 917 | target_pid_to_str (ptid_of (thr))); |
| 918 | } |
| 919 | } |
| 920 | |
| 921 | lwp->stop_pc = pc; |
| 922 | current_thread = saved_thread; |
| 923 | return true; |
| 924 | } |
| 925 | |
| 926 | static struct lwp_info * |
| 927 | add_lwp (ptid_t ptid) |
| 928 | { |
| 929 | struct lwp_info *lwp; |
| 930 | |
| 931 | lwp = XCNEW (struct lwp_info); |
| 932 | |
| 933 | lwp->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
| 934 | |
| 935 | lwp->thread = add_thread (ptid, lwp); |
| 936 | |
| 937 | if (the_low_target.new_thread != NULL) |
| 938 | the_low_target.new_thread (lwp); |
| 939 | |
| 940 | return lwp; |
| 941 | } |
| 942 | |
| 943 | /* Callback to be used when calling fork_inferior, responsible for |
| 944 | actually initiating the tracing of the inferior. */ |
| 945 | |
| 946 | static void |
| 947 | linux_ptrace_fun () |
| 948 | { |
| 949 | if (ptrace (PTRACE_TRACEME, 0, (PTRACE_TYPE_ARG3) 0, |
| 950 | (PTRACE_TYPE_ARG4) 0) < 0) |
| 951 | trace_start_error_with_name ("ptrace"); |
| 952 | |
| 953 | if (setpgid (0, 0) < 0) |
| 954 | trace_start_error_with_name ("setpgid"); |
| 955 | |
| 956 | /* If GDBserver is connected to gdb via stdio, redirect the inferior's |
| 957 | stdout to stderr so that inferior i/o doesn't corrupt the connection. |
| 958 | Also, redirect stdin to /dev/null. */ |
| 959 | if (remote_connection_is_stdio ()) |
| 960 | { |
| 961 | if (close (0) < 0) |
| 962 | trace_start_error_with_name ("close"); |
| 963 | if (open ("/dev/null", O_RDONLY) < 0) |
| 964 | trace_start_error_with_name ("open"); |
| 965 | if (dup2 (2, 1) < 0) |
| 966 | trace_start_error_with_name ("dup2"); |
| 967 | if (write (2, "stdin/stdout redirected\n", |
| 968 | sizeof ("stdin/stdout redirected\n") - 1) < 0) |
| 969 | { |
| 970 | /* Errors ignored. */; |
| 971 | } |
| 972 | } |
| 973 | } |
| 974 | |
| 975 | /* Start an inferior process and returns its pid. |
| 976 | PROGRAM is the name of the program to be started, and PROGRAM_ARGS |
| 977 | are its arguments. */ |
| 978 | |
| 979 | int |
| 980 | linux_process_target::create_inferior (const char *program, |
| 981 | const std::vector<char *> &program_args) |
| 982 | { |
| 983 | client_state &cs = get_client_state (); |
| 984 | struct lwp_info *new_lwp; |
| 985 | int pid; |
| 986 | ptid_t ptid; |
| 987 | |
| 988 | { |
| 989 | maybe_disable_address_space_randomization restore_personality |
| 990 | (cs.disable_randomization); |
| 991 | std::string str_program_args = stringify_argv (program_args); |
| 992 | |
| 993 | pid = fork_inferior (program, |
| 994 | str_program_args.c_str (), |
| 995 | get_environ ()->envp (), linux_ptrace_fun, |
| 996 | NULL, NULL, NULL, NULL); |
| 997 | } |
| 998 | |
| 999 | linux_add_process (pid, 0); |
| 1000 | |
| 1001 | ptid = ptid_t (pid, pid, 0); |
| 1002 | new_lwp = add_lwp (ptid); |
| 1003 | new_lwp->must_set_ptrace_flags = 1; |
| 1004 | |
| 1005 | post_fork_inferior (pid, program); |
| 1006 | |
| 1007 | return pid; |
| 1008 | } |
| 1009 | |
| 1010 | /* Implement the post_create_inferior target_ops method. */ |
| 1011 | |
| 1012 | void |
| 1013 | linux_process_target::post_create_inferior () |
| 1014 | { |
| 1015 | struct lwp_info *lwp = get_thread_lwp (current_thread); |
| 1016 | |
| 1017 | low_arch_setup (); |
| 1018 | |
| 1019 | if (lwp->must_set_ptrace_flags) |
| 1020 | { |
| 1021 | struct process_info *proc = current_process (); |
| 1022 | int options = linux_low_ptrace_options (proc->attached); |
| 1023 | |
| 1024 | linux_enable_event_reporting (lwpid_of (current_thread), options); |
| 1025 | lwp->must_set_ptrace_flags = 0; |
| 1026 | } |
| 1027 | } |
| 1028 | |
| 1029 | /* Attach to an inferior process. Returns 0 on success, ERRNO on |
| 1030 | error. */ |
| 1031 | |
| 1032 | int |
| 1033 | linux_attach_lwp (ptid_t ptid) |
| 1034 | { |
| 1035 | struct lwp_info *new_lwp; |
| 1036 | int lwpid = ptid.lwp (); |
| 1037 | |
| 1038 | if (ptrace (PTRACE_ATTACH, lwpid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0) |
| 1039 | != 0) |
| 1040 | return errno; |
| 1041 | |
| 1042 | new_lwp = add_lwp (ptid); |
| 1043 | |
| 1044 | /* We need to wait for SIGSTOP before being able to make the next |
| 1045 | ptrace call on this LWP. */ |
| 1046 | new_lwp->must_set_ptrace_flags = 1; |
| 1047 | |
| 1048 | if (linux_proc_pid_is_stopped (lwpid)) |
| 1049 | { |
| 1050 | if (debug_threads) |
| 1051 | debug_printf ("Attached to a stopped process\n"); |
| 1052 | |
| 1053 | /* The process is definitely stopped. It is in a job control |
| 1054 | stop, unless the kernel predates the TASK_STOPPED / |
| 1055 | TASK_TRACED distinction, in which case it might be in a |
| 1056 | ptrace stop. Make sure it is in a ptrace stop; from there we |
| 1057 | can kill it, signal it, et cetera. |
| 1058 | |
| 1059 | First make sure there is a pending SIGSTOP. Since we are |
| 1060 | already attached, the process can not transition from stopped |
| 1061 | to running without a PTRACE_CONT; so we know this signal will |
| 1062 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is |
| 1063 | probably already in the queue (unless this kernel is old |
| 1064 | enough to use TASK_STOPPED for ptrace stops); but since |
| 1065 | SIGSTOP is not an RT signal, it can only be queued once. */ |
| 1066 | kill_lwp (lwpid, SIGSTOP); |
| 1067 | |
| 1068 | /* Finally, resume the stopped process. This will deliver the |
| 1069 | SIGSTOP (or a higher priority signal, just like normal |
| 1070 | PTRACE_ATTACH), which we'll catch later on. */ |
| 1071 | ptrace (PTRACE_CONT, lwpid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0); |
| 1072 | } |
| 1073 | |
| 1074 | /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH |
| 1075 | brings it to a halt. |
| 1076 | |
| 1077 | There are several cases to consider here: |
| 1078 | |
| 1079 | 1) gdbserver has already attached to the process and is being notified |
| 1080 | of a new thread that is being created. |
| 1081 | In this case we should ignore that SIGSTOP and resume the |
| 1082 | process. This is handled below by setting stop_expected = 1, |
| 1083 | and the fact that add_thread sets last_resume_kind == |
| 1084 | resume_continue. |
| 1085 | |
| 1086 | 2) This is the first thread (the process thread), and we're attaching |
| 1087 | to it via attach_inferior. |
| 1088 | In this case we want the process thread to stop. |
| 1089 | This is handled by having linux_attach set last_resume_kind == |
| 1090 | resume_stop after we return. |
| 1091 | |
| 1092 | If the pid we are attaching to is also the tgid, we attach to and |
| 1093 | stop all the existing threads. Otherwise, we attach to pid and |
| 1094 | ignore any other threads in the same group as this pid. |
| 1095 | |
| 1096 | 3) GDB is connecting to gdbserver and is requesting an enumeration of all |
| 1097 | existing threads. |
| 1098 | In this case we want the thread to stop. |
| 1099 | FIXME: This case is currently not properly handled. |
| 1100 | We should wait for the SIGSTOP but don't. Things work apparently |
| 1101 | because enough time passes between when we ptrace (ATTACH) and when |
| 1102 | gdb makes the next ptrace call on the thread. |
| 1103 | |
| 1104 | On the other hand, if we are currently trying to stop all threads, we |
| 1105 | should treat the new thread as if we had sent it a SIGSTOP. This works |
| 1106 | because we are guaranteed that the add_lwp call above added us to the |
| 1107 | end of the list, and so the new thread has not yet reached |
| 1108 | wait_for_sigstop (but will). */ |
| 1109 | new_lwp->stop_expected = 1; |
| 1110 | |
| 1111 | return 0; |
| 1112 | } |
| 1113 | |
| 1114 | /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not |
| 1115 | already attached. Returns true if a new LWP is found, false |
| 1116 | otherwise. */ |
| 1117 | |
| 1118 | static int |
| 1119 | attach_proc_task_lwp_callback (ptid_t ptid) |
| 1120 | { |
| 1121 | /* Is this a new thread? */ |
| 1122 | if (find_thread_ptid (ptid) == NULL) |
| 1123 | { |
| 1124 | int lwpid = ptid.lwp (); |
| 1125 | int err; |
| 1126 | |
| 1127 | if (debug_threads) |
| 1128 | debug_printf ("Found new lwp %d\n", lwpid); |
| 1129 | |
| 1130 | err = linux_attach_lwp (ptid); |
| 1131 | |
| 1132 | /* Be quiet if we simply raced with the thread exiting. EPERM |
| 1133 | is returned if the thread's task still exists, and is marked |
| 1134 | as exited or zombie, as well as other conditions, so in that |
| 1135 | case, confirm the status in /proc/PID/status. */ |
| 1136 | if (err == ESRCH |
| 1137 | || (err == EPERM && linux_proc_pid_is_gone (lwpid))) |
| 1138 | { |
| 1139 | if (debug_threads) |
| 1140 | { |
| 1141 | debug_printf ("Cannot attach to lwp %d: " |
| 1142 | "thread is gone (%d: %s)\n", |
| 1143 | lwpid, err, safe_strerror (err)); |
| 1144 | } |
| 1145 | } |
| 1146 | else if (err != 0) |
| 1147 | { |
| 1148 | std::string reason |
| 1149 | = linux_ptrace_attach_fail_reason_string (ptid, err); |
| 1150 | |
| 1151 | warning (_("Cannot attach to lwp %d: %s"), lwpid, reason.c_str ()); |
| 1152 | } |
| 1153 | |
| 1154 | return 1; |
| 1155 | } |
| 1156 | return 0; |
| 1157 | } |
| 1158 | |
| 1159 | static void async_file_mark (void); |
| 1160 | |
| 1161 | /* Attach to PID. If PID is the tgid, attach to it and all |
| 1162 | of its threads. */ |
| 1163 | |
| 1164 | int |
| 1165 | linux_process_target::attach (unsigned long pid) |
| 1166 | { |
| 1167 | struct process_info *proc; |
| 1168 | struct thread_info *initial_thread; |
| 1169 | ptid_t ptid = ptid_t (pid, pid, 0); |
| 1170 | int err; |
| 1171 | |
| 1172 | proc = linux_add_process (pid, 1); |
| 1173 | |
| 1174 | /* Attach to PID. We will check for other threads |
| 1175 | soon. */ |
| 1176 | err = linux_attach_lwp (ptid); |
| 1177 | if (err != 0) |
| 1178 | { |
| 1179 | remove_process (proc); |
| 1180 | |
| 1181 | std::string reason = linux_ptrace_attach_fail_reason_string (ptid, err); |
| 1182 | error ("Cannot attach to process %ld: %s", pid, reason.c_str ()); |
| 1183 | } |
| 1184 | |
| 1185 | /* Don't ignore the initial SIGSTOP if we just attached to this |
| 1186 | process. It will be collected by wait shortly. */ |
| 1187 | initial_thread = find_thread_ptid (ptid_t (pid, pid, 0)); |
| 1188 | initial_thread->last_resume_kind = resume_stop; |
| 1189 | |
| 1190 | /* We must attach to every LWP. If /proc is mounted, use that to |
| 1191 | find them now. On the one hand, the inferior may be using raw |
| 1192 | clone instead of using pthreads. On the other hand, even if it |
| 1193 | is using pthreads, GDB may not be connected yet (thread_db needs |
| 1194 | to do symbol lookups, through qSymbol). Also, thread_db walks |
| 1195 | structures in the inferior's address space to find the list of |
| 1196 | threads/LWPs, and those structures may well be corrupted. Note |
| 1197 | that once thread_db is loaded, we'll still use it to list threads |
| 1198 | and associate pthread info with each LWP. */ |
| 1199 | linux_proc_attach_tgid_threads (pid, attach_proc_task_lwp_callback); |
| 1200 | |
| 1201 | /* GDB will shortly read the xml target description for this |
| 1202 | process, to figure out the process' architecture. But the target |
| 1203 | description is only filled in when the first process/thread in |
| 1204 | the thread group reports its initial PTRACE_ATTACH SIGSTOP. Do |
| 1205 | that now, otherwise, if GDB is fast enough, it could read the |
| 1206 | target description _before_ that initial stop. */ |
| 1207 | if (non_stop) |
| 1208 | { |
| 1209 | struct lwp_info *lwp; |
| 1210 | int wstat, lwpid; |
| 1211 | ptid_t pid_ptid = ptid_t (pid); |
| 1212 | |
| 1213 | lwpid = wait_for_event_filtered (pid_ptid, pid_ptid, &wstat, __WALL); |
| 1214 | gdb_assert (lwpid > 0); |
| 1215 | |
| 1216 | lwp = find_lwp_pid (ptid_t (lwpid)); |
| 1217 | |
| 1218 | if (!WIFSTOPPED (wstat) || WSTOPSIG (wstat) != SIGSTOP) |
| 1219 | { |
| 1220 | lwp->status_pending_p = 1; |
| 1221 | lwp->status_pending = wstat; |
| 1222 | } |
| 1223 | |
| 1224 | initial_thread->last_resume_kind = resume_continue; |
| 1225 | |
| 1226 | async_file_mark (); |
| 1227 | |
| 1228 | gdb_assert (proc->tdesc != NULL); |
| 1229 | } |
| 1230 | |
| 1231 | return 0; |
| 1232 | } |
| 1233 | |
| 1234 | static int |
| 1235 | last_thread_of_process_p (int pid) |
| 1236 | { |
| 1237 | bool seen_one = false; |
| 1238 | |
| 1239 | thread_info *thread = find_thread (pid, [&] (thread_info *thr_arg) |
| 1240 | { |
| 1241 | if (!seen_one) |
| 1242 | { |
| 1243 | /* This is the first thread of this process we see. */ |
| 1244 | seen_one = true; |
| 1245 | return false; |
| 1246 | } |
| 1247 | else |
| 1248 | { |
| 1249 | /* This is the second thread of this process we see. */ |
| 1250 | return true; |
| 1251 | } |
| 1252 | }); |
| 1253 | |
| 1254 | return thread == NULL; |
| 1255 | } |
| 1256 | |
| 1257 | /* Kill LWP. */ |
| 1258 | |
| 1259 | static void |
| 1260 | linux_kill_one_lwp (struct lwp_info *lwp) |
| 1261 | { |
| 1262 | struct thread_info *thr = get_lwp_thread (lwp); |
| 1263 | int pid = lwpid_of (thr); |
| 1264 | |
| 1265 | /* PTRACE_KILL is unreliable. After stepping into a signal handler, |
| 1266 | there is no signal context, and ptrace(PTRACE_KILL) (or |
| 1267 | ptrace(PTRACE_CONT, SIGKILL), pretty much the same) acts like |
| 1268 | ptrace(CONT, pid, 0,0) and just resumes the tracee. A better |
| 1269 | alternative is to kill with SIGKILL. We only need one SIGKILL |
| 1270 | per process, not one for each thread. But since we still support |
| 1271 | support debugging programs using raw clone without CLONE_THREAD, |
| 1272 | we send one for each thread. For years, we used PTRACE_KILL |
| 1273 | only, so we're being a bit paranoid about some old kernels where |
| 1274 | PTRACE_KILL might work better (dubious if there are any such, but |
| 1275 | that's why it's paranoia), so we try SIGKILL first, PTRACE_KILL |
| 1276 | second, and so we're fine everywhere. */ |
| 1277 | |
| 1278 | errno = 0; |
| 1279 | kill_lwp (pid, SIGKILL); |
| 1280 | if (debug_threads) |
| 1281 | { |
| 1282 | int save_errno = errno; |
| 1283 | |
| 1284 | debug_printf ("LKL: kill_lwp (SIGKILL) %s, 0, 0 (%s)\n", |
| 1285 | target_pid_to_str (ptid_of (thr)), |
| 1286 | save_errno ? safe_strerror (save_errno) : "OK"); |
| 1287 | } |
| 1288 | |
| 1289 | errno = 0; |
| 1290 | ptrace (PTRACE_KILL, pid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0); |
| 1291 | if (debug_threads) |
| 1292 | { |
| 1293 | int save_errno = errno; |
| 1294 | |
| 1295 | debug_printf ("LKL: PTRACE_KILL %s, 0, 0 (%s)\n", |
| 1296 | target_pid_to_str (ptid_of (thr)), |
| 1297 | save_errno ? safe_strerror (save_errno) : "OK"); |
| 1298 | } |
| 1299 | } |
| 1300 | |
| 1301 | /* Kill LWP and wait for it to die. */ |
| 1302 | |
| 1303 | static void |
| 1304 | kill_wait_lwp (struct lwp_info *lwp) |
| 1305 | { |
| 1306 | struct thread_info *thr = get_lwp_thread (lwp); |
| 1307 | int pid = ptid_of (thr).pid (); |
| 1308 | int lwpid = ptid_of (thr).lwp (); |
| 1309 | int wstat; |
| 1310 | int res; |
| 1311 | |
| 1312 | if (debug_threads) |
| 1313 | debug_printf ("kwl: killing lwp %d, for pid: %d\n", lwpid, pid); |
| 1314 | |
| 1315 | do |
| 1316 | { |
| 1317 | linux_kill_one_lwp (lwp); |
| 1318 | |
| 1319 | /* Make sure it died. Notes: |
| 1320 | |
| 1321 | - The loop is most likely unnecessary. |
| 1322 | |
| 1323 | - We don't use wait_for_event as that could delete lwps |
| 1324 | while we're iterating over them. We're not interested in |
| 1325 | any pending status at this point, only in making sure all |
| 1326 | wait status on the kernel side are collected until the |
| 1327 | process is reaped. |
| 1328 | |
| 1329 | - We don't use __WALL here as the __WALL emulation relies on |
| 1330 | SIGCHLD, and killing a stopped process doesn't generate |
| 1331 | one, nor an exit status. |
| 1332 | */ |
| 1333 | res = my_waitpid (lwpid, &wstat, 0); |
| 1334 | if (res == -1 && errno == ECHILD) |
| 1335 | res = my_waitpid (lwpid, &wstat, __WCLONE); |
| 1336 | } while (res > 0 && WIFSTOPPED (wstat)); |
| 1337 | |
| 1338 | /* Even if it was stopped, the child may have already disappeared. |
| 1339 | E.g., if it was killed by SIGKILL. */ |
| 1340 | if (res < 0 && errno != ECHILD) |
| 1341 | perror_with_name ("kill_wait_lwp"); |
| 1342 | } |
| 1343 | |
| 1344 | /* Callback for `for_each_thread'. Kills an lwp of a given process, |
| 1345 | except the leader. */ |
| 1346 | |
| 1347 | static void |
| 1348 | kill_one_lwp_callback (thread_info *thread, int pid) |
| 1349 | { |
| 1350 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 1351 | |
| 1352 | /* We avoid killing the first thread here, because of a Linux kernel (at |
| 1353 | least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before |
| 1354 | the children get a chance to be reaped, it will remain a zombie |
| 1355 | forever. */ |
| 1356 | |
| 1357 | if (lwpid_of (thread) == pid) |
| 1358 | { |
| 1359 | if (debug_threads) |
| 1360 | debug_printf ("lkop: is last of process %s\n", |
| 1361 | target_pid_to_str (thread->id)); |
| 1362 | return; |
| 1363 | } |
| 1364 | |
| 1365 | kill_wait_lwp (lwp); |
| 1366 | } |
| 1367 | |
| 1368 | int |
| 1369 | linux_process_target::kill (process_info *process) |
| 1370 | { |
| 1371 | int pid = process->pid; |
| 1372 | |
| 1373 | /* If we're killing a running inferior, make sure it is stopped |
| 1374 | first, as PTRACE_KILL will not work otherwise. */ |
| 1375 | stop_all_lwps (0, NULL); |
| 1376 | |
| 1377 | for_each_thread (pid, [&] (thread_info *thread) |
| 1378 | { |
| 1379 | kill_one_lwp_callback (thread, pid); |
| 1380 | }); |
| 1381 | |
| 1382 | /* See the comment in linux_kill_one_lwp. We did not kill the first |
| 1383 | thread in the list, so do so now. */ |
| 1384 | lwp_info *lwp = find_lwp_pid (ptid_t (pid)); |
| 1385 | |
| 1386 | if (lwp == NULL) |
| 1387 | { |
| 1388 | if (debug_threads) |
| 1389 | debug_printf ("lk_1: cannot find lwp for pid: %d\n", |
| 1390 | pid); |
| 1391 | } |
| 1392 | else |
| 1393 | kill_wait_lwp (lwp); |
| 1394 | |
| 1395 | mourn (process); |
| 1396 | |
| 1397 | /* Since we presently can only stop all lwps of all processes, we |
| 1398 | need to unstop lwps of other processes. */ |
| 1399 | unstop_all_lwps (0, NULL); |
| 1400 | return 0; |
| 1401 | } |
| 1402 | |
| 1403 | /* Get pending signal of THREAD, for detaching purposes. This is the |
| 1404 | signal the thread last stopped for, which we need to deliver to the |
| 1405 | thread when detaching, otherwise, it'd be suppressed/lost. */ |
| 1406 | |
| 1407 | static int |
| 1408 | get_detach_signal (struct thread_info *thread) |
| 1409 | { |
| 1410 | client_state &cs = get_client_state (); |
| 1411 | enum gdb_signal signo = GDB_SIGNAL_0; |
| 1412 | int status; |
| 1413 | struct lwp_info *lp = get_thread_lwp (thread); |
| 1414 | |
| 1415 | if (lp->status_pending_p) |
| 1416 | status = lp->status_pending; |
| 1417 | else |
| 1418 | { |
| 1419 | /* If the thread had been suspended by gdbserver, and it stopped |
| 1420 | cleanly, then it'll have stopped with SIGSTOP. But we don't |
| 1421 | want to deliver that SIGSTOP. */ |
| 1422 | if (thread->last_status.kind != TARGET_WAITKIND_STOPPED |
| 1423 | || thread->last_status.value.sig == GDB_SIGNAL_0) |
| 1424 | return 0; |
| 1425 | |
| 1426 | /* Otherwise, we may need to deliver the signal we |
| 1427 | intercepted. */ |
| 1428 | status = lp->last_status; |
| 1429 | } |
| 1430 | |
| 1431 | if (!WIFSTOPPED (status)) |
| 1432 | { |
| 1433 | if (debug_threads) |
| 1434 | debug_printf ("GPS: lwp %s hasn't stopped: no pending signal\n", |
| 1435 | target_pid_to_str (ptid_of (thread))); |
| 1436 | return 0; |
| 1437 | } |
| 1438 | |
| 1439 | /* Extended wait statuses aren't real SIGTRAPs. */ |
| 1440 | if (WSTOPSIG (status) == SIGTRAP && linux_is_extended_waitstatus (status)) |
| 1441 | { |
| 1442 | if (debug_threads) |
| 1443 | debug_printf ("GPS: lwp %s had stopped with extended " |
| 1444 | "status: no pending signal\n", |
| 1445 | target_pid_to_str (ptid_of (thread))); |
| 1446 | return 0; |
| 1447 | } |
| 1448 | |
| 1449 | signo = gdb_signal_from_host (WSTOPSIG (status)); |
| 1450 | |
| 1451 | if (cs.program_signals_p && !cs.program_signals[signo]) |
| 1452 | { |
| 1453 | if (debug_threads) |
| 1454 | debug_printf ("GPS: lwp %s had signal %s, but it is in nopass state\n", |
| 1455 | target_pid_to_str (ptid_of (thread)), |
| 1456 | gdb_signal_to_string (signo)); |
| 1457 | return 0; |
| 1458 | } |
| 1459 | else if (!cs.program_signals_p |
| 1460 | /* If we have no way to know which signals GDB does not |
| 1461 | want to have passed to the program, assume |
| 1462 | SIGTRAP/SIGINT, which is GDB's default. */ |
| 1463 | && (signo == GDB_SIGNAL_TRAP || signo == GDB_SIGNAL_INT)) |
| 1464 | { |
| 1465 | if (debug_threads) |
| 1466 | debug_printf ("GPS: lwp %s had signal %s, " |
| 1467 | "but we don't know if we should pass it. " |
| 1468 | "Default to not.\n", |
| 1469 | target_pid_to_str (ptid_of (thread)), |
| 1470 | gdb_signal_to_string (signo)); |
| 1471 | return 0; |
| 1472 | } |
| 1473 | else |
| 1474 | { |
| 1475 | if (debug_threads) |
| 1476 | debug_printf ("GPS: lwp %s has pending signal %s: delivering it.\n", |
| 1477 | target_pid_to_str (ptid_of (thread)), |
| 1478 | gdb_signal_to_string (signo)); |
| 1479 | |
| 1480 | return WSTOPSIG (status); |
| 1481 | } |
| 1482 | } |
| 1483 | |
| 1484 | /* Detach from LWP. */ |
| 1485 | |
| 1486 | static void |
| 1487 | linux_detach_one_lwp (struct lwp_info *lwp) |
| 1488 | { |
| 1489 | struct thread_info *thread = get_lwp_thread (lwp); |
| 1490 | int sig; |
| 1491 | int lwpid; |
| 1492 | |
| 1493 | /* If there is a pending SIGSTOP, get rid of it. */ |
| 1494 | if (lwp->stop_expected) |
| 1495 | { |
| 1496 | if (debug_threads) |
| 1497 | debug_printf ("Sending SIGCONT to %s\n", |
| 1498 | target_pid_to_str (ptid_of (thread))); |
| 1499 | |
| 1500 | kill_lwp (lwpid_of (thread), SIGCONT); |
| 1501 | lwp->stop_expected = 0; |
| 1502 | } |
| 1503 | |
| 1504 | /* Pass on any pending signal for this thread. */ |
| 1505 | sig = get_detach_signal (thread); |
| 1506 | |
| 1507 | /* Preparing to resume may try to write registers, and fail if the |
| 1508 | lwp is zombie. If that happens, ignore the error. We'll handle |
| 1509 | it below, when detach fails with ESRCH. */ |
| 1510 | try |
| 1511 | { |
| 1512 | /* Flush any pending changes to the process's registers. */ |
| 1513 | regcache_invalidate_thread (thread); |
| 1514 | |
| 1515 | /* Finally, let it resume. */ |
| 1516 | if (the_low_target.prepare_to_resume != NULL) |
| 1517 | the_low_target.prepare_to_resume (lwp); |
| 1518 | } |
| 1519 | catch (const gdb_exception_error &ex) |
| 1520 | { |
| 1521 | if (!check_ptrace_stopped_lwp_gone (lwp)) |
| 1522 | throw; |
| 1523 | } |
| 1524 | |
| 1525 | lwpid = lwpid_of (thread); |
| 1526 | if (ptrace (PTRACE_DETACH, lwpid, (PTRACE_TYPE_ARG3) 0, |
| 1527 | (PTRACE_TYPE_ARG4) (long) sig) < 0) |
| 1528 | { |
| 1529 | int save_errno = errno; |
| 1530 | |
| 1531 | /* We know the thread exists, so ESRCH must mean the lwp is |
| 1532 | zombie. This can happen if one of the already-detached |
| 1533 | threads exits the whole thread group. In that case we're |
| 1534 | still attached, and must reap the lwp. */ |
| 1535 | if (save_errno == ESRCH) |
| 1536 | { |
| 1537 | int ret, status; |
| 1538 | |
| 1539 | ret = my_waitpid (lwpid, &status, __WALL); |
| 1540 | if (ret == -1) |
| 1541 | { |
| 1542 | warning (_("Couldn't reap LWP %d while detaching: %s"), |
| 1543 | lwpid, safe_strerror (errno)); |
| 1544 | } |
| 1545 | else if (!WIFEXITED (status) && !WIFSIGNALED (status)) |
| 1546 | { |
| 1547 | warning (_("Reaping LWP %d while detaching " |
| 1548 | "returned unexpected status 0x%x"), |
| 1549 | lwpid, status); |
| 1550 | } |
| 1551 | } |
| 1552 | else |
| 1553 | { |
| 1554 | error (_("Can't detach %s: %s"), |
| 1555 | target_pid_to_str (ptid_of (thread)), |
| 1556 | safe_strerror (save_errno)); |
| 1557 | } |
| 1558 | } |
| 1559 | else if (debug_threads) |
| 1560 | { |
| 1561 | debug_printf ("PTRACE_DETACH (%s, %s, 0) (OK)\n", |
| 1562 | target_pid_to_str (ptid_of (thread)), |
| 1563 | strsignal (sig)); |
| 1564 | } |
| 1565 | |
| 1566 | delete_lwp (lwp); |
| 1567 | } |
| 1568 | |
| 1569 | /* Callback for for_each_thread. Detaches from non-leader threads of a |
| 1570 | given process. */ |
| 1571 | |
| 1572 | static void |
| 1573 | linux_detach_lwp_callback (thread_info *thread) |
| 1574 | { |
| 1575 | /* We don't actually detach from the thread group leader just yet. |
| 1576 | If the thread group exits, we must reap the zombie clone lwps |
| 1577 | before we're able to reap the leader. */ |
| 1578 | if (thread->id.pid () == thread->id.lwp ()) |
| 1579 | return; |
| 1580 | |
| 1581 | lwp_info *lwp = get_thread_lwp (thread); |
| 1582 | linux_detach_one_lwp (lwp); |
| 1583 | } |
| 1584 | |
| 1585 | int |
| 1586 | linux_process_target::detach (process_info *process) |
| 1587 | { |
| 1588 | struct lwp_info *main_lwp; |
| 1589 | |
| 1590 | /* As there's a step over already in progress, let it finish first, |
| 1591 | otherwise nesting a stabilize_threads operation on top gets real |
| 1592 | messy. */ |
| 1593 | complete_ongoing_step_over (); |
| 1594 | |
| 1595 | /* Stop all threads before detaching. First, ptrace requires that |
| 1596 | the thread is stopped to successfully detach. Second, thread_db |
| 1597 | may need to uninstall thread event breakpoints from memory, which |
| 1598 | only works with a stopped process anyway. */ |
| 1599 | stop_all_lwps (0, NULL); |
| 1600 | |
| 1601 | #ifdef USE_THREAD_DB |
| 1602 | thread_db_detach (process); |
| 1603 | #endif |
| 1604 | |
| 1605 | /* Stabilize threads (move out of jump pads). */ |
| 1606 | target_stabilize_threads (); |
| 1607 | |
| 1608 | /* Detach from the clone lwps first. If the thread group exits just |
| 1609 | while we're detaching, we must reap the clone lwps before we're |
| 1610 | able to reap the leader. */ |
| 1611 | for_each_thread (process->pid, linux_detach_lwp_callback); |
| 1612 | |
| 1613 | main_lwp = find_lwp_pid (ptid_t (process->pid)); |
| 1614 | linux_detach_one_lwp (main_lwp); |
| 1615 | |
| 1616 | mourn (process); |
| 1617 | |
| 1618 | /* Since we presently can only stop all lwps of all processes, we |
| 1619 | need to unstop lwps of other processes. */ |
| 1620 | unstop_all_lwps (0, NULL); |
| 1621 | return 0; |
| 1622 | } |
| 1623 | |
| 1624 | /* Remove all LWPs that belong to process PROC from the lwp list. */ |
| 1625 | |
| 1626 | void |
| 1627 | linux_process_target::mourn (process_info *process) |
| 1628 | { |
| 1629 | struct process_info_private *priv; |
| 1630 | |
| 1631 | #ifdef USE_THREAD_DB |
| 1632 | thread_db_mourn (process); |
| 1633 | #endif |
| 1634 | |
| 1635 | for_each_thread (process->pid, [] (thread_info *thread) |
| 1636 | { |
| 1637 | delete_lwp (get_thread_lwp (thread)); |
| 1638 | }); |
| 1639 | |
| 1640 | /* Freeing all private data. */ |
| 1641 | priv = process->priv; |
| 1642 | if (the_low_target.delete_process != NULL) |
| 1643 | the_low_target.delete_process (priv->arch_private); |
| 1644 | else |
| 1645 | gdb_assert (priv->arch_private == NULL); |
| 1646 | free (priv); |
| 1647 | process->priv = NULL; |
| 1648 | |
| 1649 | remove_process (process); |
| 1650 | } |
| 1651 | |
| 1652 | void |
| 1653 | linux_process_target::join (int pid) |
| 1654 | { |
| 1655 | int status, ret; |
| 1656 | |
| 1657 | do { |
| 1658 | ret = my_waitpid (pid, &status, 0); |
| 1659 | if (WIFEXITED (status) || WIFSIGNALED (status)) |
| 1660 | break; |
| 1661 | } while (ret != -1 || errno != ECHILD); |
| 1662 | } |
| 1663 | |
| 1664 | /* Return true if the given thread is still alive. */ |
| 1665 | |
| 1666 | bool |
| 1667 | linux_process_target::thread_alive (ptid_t ptid) |
| 1668 | { |
| 1669 | struct lwp_info *lwp = find_lwp_pid (ptid); |
| 1670 | |
| 1671 | /* We assume we always know if a thread exits. If a whole process |
| 1672 | exited but we still haven't been able to report it to GDB, we'll |
| 1673 | hold on to the last lwp of the dead process. */ |
| 1674 | if (lwp != NULL) |
| 1675 | return !lwp_is_marked_dead (lwp); |
| 1676 | else |
| 1677 | return 0; |
| 1678 | } |
| 1679 | |
| 1680 | bool |
| 1681 | linux_process_target::thread_still_has_status_pending (thread_info *thread) |
| 1682 | { |
| 1683 | struct lwp_info *lp = get_thread_lwp (thread); |
| 1684 | |
| 1685 | if (!lp->status_pending_p) |
| 1686 | return 0; |
| 1687 | |
| 1688 | if (thread->last_resume_kind != resume_stop |
| 1689 | && (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
| 1690 | || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)) |
| 1691 | { |
| 1692 | struct thread_info *saved_thread; |
| 1693 | CORE_ADDR pc; |
| 1694 | int discard = 0; |
| 1695 | |
| 1696 | gdb_assert (lp->last_status != 0); |
| 1697 | |
| 1698 | pc = get_pc (lp); |
| 1699 | |
| 1700 | saved_thread = current_thread; |
| 1701 | current_thread = thread; |
| 1702 | |
| 1703 | if (pc != lp->stop_pc) |
| 1704 | { |
| 1705 | if (debug_threads) |
| 1706 | debug_printf ("PC of %ld changed\n", |
| 1707 | lwpid_of (thread)); |
| 1708 | discard = 1; |
| 1709 | } |
| 1710 | |
| 1711 | #if !USE_SIGTRAP_SIGINFO |
| 1712 | else if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
| 1713 | && !low_breakpoint_at (pc)) |
| 1714 | { |
| 1715 | if (debug_threads) |
| 1716 | debug_printf ("previous SW breakpoint of %ld gone\n", |
| 1717 | lwpid_of (thread)); |
| 1718 | discard = 1; |
| 1719 | } |
| 1720 | else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT |
| 1721 | && !hardware_breakpoint_inserted_here (pc)) |
| 1722 | { |
| 1723 | if (debug_threads) |
| 1724 | debug_printf ("previous HW breakpoint of %ld gone\n", |
| 1725 | lwpid_of (thread)); |
| 1726 | discard = 1; |
| 1727 | } |
| 1728 | #endif |
| 1729 | |
| 1730 | current_thread = saved_thread; |
| 1731 | |
| 1732 | if (discard) |
| 1733 | { |
| 1734 | if (debug_threads) |
| 1735 | debug_printf ("discarding pending breakpoint status\n"); |
| 1736 | lp->status_pending_p = 0; |
| 1737 | return 0; |
| 1738 | } |
| 1739 | } |
| 1740 | |
| 1741 | return 1; |
| 1742 | } |
| 1743 | |
| 1744 | /* Returns true if LWP is resumed from the client's perspective. */ |
| 1745 | |
| 1746 | static int |
| 1747 | lwp_resumed (struct lwp_info *lwp) |
| 1748 | { |
| 1749 | struct thread_info *thread = get_lwp_thread (lwp); |
| 1750 | |
| 1751 | if (thread->last_resume_kind != resume_stop) |
| 1752 | return 1; |
| 1753 | |
| 1754 | /* Did gdb send us a `vCont;t', but we haven't reported the |
| 1755 | corresponding stop to gdb yet? If so, the thread is still |
| 1756 | resumed/running from gdb's perspective. */ |
| 1757 | if (thread->last_resume_kind == resume_stop |
| 1758 | && thread->last_status.kind == TARGET_WAITKIND_IGNORE) |
| 1759 | return 1; |
| 1760 | |
| 1761 | return 0; |
| 1762 | } |
| 1763 | |
| 1764 | bool |
| 1765 | linux_process_target::status_pending_p_callback (thread_info *thread, |
| 1766 | ptid_t ptid) |
| 1767 | { |
| 1768 | struct lwp_info *lp = get_thread_lwp (thread); |
| 1769 | |
| 1770 | /* Check if we're only interested in events from a specific process |
| 1771 | or a specific LWP. */ |
| 1772 | if (!thread->id.matches (ptid)) |
| 1773 | return 0; |
| 1774 | |
| 1775 | if (!lwp_resumed (lp)) |
| 1776 | return 0; |
| 1777 | |
| 1778 | if (lp->status_pending_p |
| 1779 | && !thread_still_has_status_pending (thread)) |
| 1780 | { |
| 1781 | resume_one_lwp (lp, lp->stepping, GDB_SIGNAL_0, NULL); |
| 1782 | return 0; |
| 1783 | } |
| 1784 | |
| 1785 | return lp->status_pending_p; |
| 1786 | } |
| 1787 | |
| 1788 | struct lwp_info * |
| 1789 | find_lwp_pid (ptid_t ptid) |
| 1790 | { |
| 1791 | thread_info *thread = find_thread ([&] (thread_info *thr_arg) |
| 1792 | { |
| 1793 | int lwp = ptid.lwp () != 0 ? ptid.lwp () : ptid.pid (); |
| 1794 | return thr_arg->id.lwp () == lwp; |
| 1795 | }); |
| 1796 | |
| 1797 | if (thread == NULL) |
| 1798 | return NULL; |
| 1799 | |
| 1800 | return get_thread_lwp (thread); |
| 1801 | } |
| 1802 | |
| 1803 | /* Return the number of known LWPs in the tgid given by PID. */ |
| 1804 | |
| 1805 | static int |
| 1806 | num_lwps (int pid) |
| 1807 | { |
| 1808 | int count = 0; |
| 1809 | |
| 1810 | for_each_thread (pid, [&] (thread_info *thread) |
| 1811 | { |
| 1812 | count++; |
| 1813 | }); |
| 1814 | |
| 1815 | return count; |
| 1816 | } |
| 1817 | |
| 1818 | /* See nat/linux-nat.h. */ |
| 1819 | |
| 1820 | struct lwp_info * |
| 1821 | iterate_over_lwps (ptid_t filter, |
| 1822 | gdb::function_view<iterate_over_lwps_ftype> callback) |
| 1823 | { |
| 1824 | thread_info *thread = find_thread (filter, [&] (thread_info *thr_arg) |
| 1825 | { |
| 1826 | lwp_info *lwp = get_thread_lwp (thr_arg); |
| 1827 | |
| 1828 | return callback (lwp); |
| 1829 | }); |
| 1830 | |
| 1831 | if (thread == NULL) |
| 1832 | return NULL; |
| 1833 | |
| 1834 | return get_thread_lwp (thread); |
| 1835 | } |
| 1836 | |
| 1837 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
| 1838 | their exits until all other threads in the group have exited. */ |
| 1839 | |
| 1840 | static void |
| 1841 | check_zombie_leaders (void) |
| 1842 | { |
| 1843 | for_each_process ([] (process_info *proc) { |
| 1844 | pid_t leader_pid = pid_of (proc); |
| 1845 | struct lwp_info *leader_lp; |
| 1846 | |
| 1847 | leader_lp = find_lwp_pid (ptid_t (leader_pid)); |
| 1848 | |
| 1849 | if (debug_threads) |
| 1850 | debug_printf ("leader_pid=%d, leader_lp!=NULL=%d, " |
| 1851 | "num_lwps=%d, zombie=%d\n", |
| 1852 | leader_pid, leader_lp!= NULL, num_lwps (leader_pid), |
| 1853 | linux_proc_pid_is_zombie (leader_pid)); |
| 1854 | |
| 1855 | if (leader_lp != NULL && !leader_lp->stopped |
| 1856 | /* Check if there are other threads in the group, as we may |
| 1857 | have raced with the inferior simply exiting. */ |
| 1858 | && !last_thread_of_process_p (leader_pid) |
| 1859 | && linux_proc_pid_is_zombie (leader_pid)) |
| 1860 | { |
| 1861 | /* A leader zombie can mean one of two things: |
| 1862 | |
| 1863 | - It exited, and there's an exit status pending |
| 1864 | available, or only the leader exited (not the whole |
| 1865 | program). In the latter case, we can't waitpid the |
| 1866 | leader's exit status until all other threads are gone. |
| 1867 | |
| 1868 | - There are 3 or more threads in the group, and a thread |
| 1869 | other than the leader exec'd. On an exec, the Linux |
| 1870 | kernel destroys all other threads (except the execing |
| 1871 | one) in the thread group, and resets the execing thread's |
| 1872 | tid to the tgid. No exit notification is sent for the |
| 1873 | execing thread -- from the ptracer's perspective, it |
| 1874 | appears as though the execing thread just vanishes. |
| 1875 | Until we reap all other threads except the leader and the |
| 1876 | execing thread, the leader will be zombie, and the |
| 1877 | execing thread will be in `D (disc sleep)'. As soon as |
| 1878 | all other threads are reaped, the execing thread changes |
| 1879 | it's tid to the tgid, and the previous (zombie) leader |
| 1880 | vanishes, giving place to the "new" leader. We could try |
| 1881 | distinguishing the exit and exec cases, by waiting once |
| 1882 | more, and seeing if something comes out, but it doesn't |
| 1883 | sound useful. The previous leader _does_ go away, and |
| 1884 | we'll re-add the new one once we see the exec event |
| 1885 | (which is just the same as what would happen if the |
| 1886 | previous leader did exit voluntarily before some other |
| 1887 | thread execs). */ |
| 1888 | |
| 1889 | if (debug_threads) |
| 1890 | debug_printf ("CZL: Thread group leader %d zombie " |
| 1891 | "(it exited, or another thread execd).\n", |
| 1892 | leader_pid); |
| 1893 | |
| 1894 | delete_lwp (leader_lp); |
| 1895 | } |
| 1896 | }); |
| 1897 | } |
| 1898 | |
| 1899 | /* Callback for `find_thread'. Returns the first LWP that is not |
| 1900 | stopped. */ |
| 1901 | |
| 1902 | static bool |
| 1903 | not_stopped_callback (thread_info *thread, ptid_t filter) |
| 1904 | { |
| 1905 | if (!thread->id.matches (filter)) |
| 1906 | return false; |
| 1907 | |
| 1908 | lwp_info *lwp = get_thread_lwp (thread); |
| 1909 | |
| 1910 | return !lwp->stopped; |
| 1911 | } |
| 1912 | |
| 1913 | /* Increment LWP's suspend count. */ |
| 1914 | |
| 1915 | static void |
| 1916 | lwp_suspended_inc (struct lwp_info *lwp) |
| 1917 | { |
| 1918 | lwp->suspended++; |
| 1919 | |
| 1920 | if (debug_threads && lwp->suspended > 4) |
| 1921 | { |
| 1922 | struct thread_info *thread = get_lwp_thread (lwp); |
| 1923 | |
| 1924 | debug_printf ("LWP %ld has a suspiciously high suspend count," |
| 1925 | " suspended=%d\n", lwpid_of (thread), lwp->suspended); |
| 1926 | } |
| 1927 | } |
| 1928 | |
| 1929 | /* Decrement LWP's suspend count. */ |
| 1930 | |
| 1931 | static void |
| 1932 | lwp_suspended_decr (struct lwp_info *lwp) |
| 1933 | { |
| 1934 | lwp->suspended--; |
| 1935 | |
| 1936 | if (lwp->suspended < 0) |
| 1937 | { |
| 1938 | struct thread_info *thread = get_lwp_thread (lwp); |
| 1939 | |
| 1940 | internal_error (__FILE__, __LINE__, |
| 1941 | "unsuspend LWP %ld, suspended=%d\n", lwpid_of (thread), |
| 1942 | lwp->suspended); |
| 1943 | } |
| 1944 | } |
| 1945 | |
| 1946 | /* This function should only be called if the LWP got a SIGTRAP. |
| 1947 | |
| 1948 | Handle any tracepoint steps or hits. Return true if a tracepoint |
| 1949 | event was handled, 0 otherwise. */ |
| 1950 | |
| 1951 | static int |
| 1952 | handle_tracepoints (struct lwp_info *lwp) |
| 1953 | { |
| 1954 | struct thread_info *tinfo = get_lwp_thread (lwp); |
| 1955 | int tpoint_related_event = 0; |
| 1956 | |
| 1957 | gdb_assert (lwp->suspended == 0); |
| 1958 | |
| 1959 | /* If this tracepoint hit causes a tracing stop, we'll immediately |
| 1960 | uninsert tracepoints. To do this, we temporarily pause all |
| 1961 | threads, unpatch away, and then unpause threads. We need to make |
| 1962 | sure the unpausing doesn't resume LWP too. */ |
| 1963 | lwp_suspended_inc (lwp); |
| 1964 | |
| 1965 | /* And we need to be sure that any all-threads-stopping doesn't try |
| 1966 | to move threads out of the jump pads, as it could deadlock the |
| 1967 | inferior (LWP could be in the jump pad, maybe even holding the |
| 1968 | lock.) */ |
| 1969 | |
| 1970 | /* Do any necessary step collect actions. */ |
| 1971 | tpoint_related_event |= tracepoint_finished_step (tinfo, lwp->stop_pc); |
| 1972 | |
| 1973 | tpoint_related_event |= handle_tracepoint_bkpts (tinfo, lwp->stop_pc); |
| 1974 | |
| 1975 | /* See if we just hit a tracepoint and do its main collect |
| 1976 | actions. */ |
| 1977 | tpoint_related_event |= tracepoint_was_hit (tinfo, lwp->stop_pc); |
| 1978 | |
| 1979 | lwp_suspended_decr (lwp); |
| 1980 | |
| 1981 | gdb_assert (lwp->suspended == 0); |
| 1982 | gdb_assert (!stabilizing_threads |
| 1983 | || (lwp->collecting_fast_tracepoint |
| 1984 | != fast_tpoint_collect_result::not_collecting)); |
| 1985 | |
| 1986 | if (tpoint_related_event) |
| 1987 | { |
| 1988 | if (debug_threads) |
| 1989 | debug_printf ("got a tracepoint event\n"); |
| 1990 | return 1; |
| 1991 | } |
| 1992 | |
| 1993 | return 0; |
| 1994 | } |
| 1995 | |
| 1996 | /* Convenience wrapper. Returns information about LWP's fast tracepoint |
| 1997 | collection status. */ |
| 1998 | |
| 1999 | static fast_tpoint_collect_result |
| 2000 | linux_fast_tracepoint_collecting (struct lwp_info *lwp, |
| 2001 | struct fast_tpoint_collect_status *status) |
| 2002 | { |
| 2003 | CORE_ADDR thread_area; |
| 2004 | struct thread_info *thread = get_lwp_thread (lwp); |
| 2005 | |
| 2006 | if (the_low_target.get_thread_area == NULL) |
| 2007 | return fast_tpoint_collect_result::not_collecting; |
| 2008 | |
| 2009 | /* Get the thread area address. This is used to recognize which |
| 2010 | thread is which when tracing with the in-process agent library. |
| 2011 | We don't read anything from the address, and treat it as opaque; |
| 2012 | it's the address itself that we assume is unique per-thread. */ |
| 2013 | if ((*the_low_target.get_thread_area) (lwpid_of (thread), &thread_area) == -1) |
| 2014 | return fast_tpoint_collect_result::not_collecting; |
| 2015 | |
| 2016 | return fast_tracepoint_collecting (thread_area, lwp->stop_pc, status); |
| 2017 | } |
| 2018 | |
| 2019 | bool |
| 2020 | linux_process_target::maybe_move_out_of_jump_pad (lwp_info *lwp, int *wstat) |
| 2021 | { |
| 2022 | struct thread_info *saved_thread; |
| 2023 | |
| 2024 | saved_thread = current_thread; |
| 2025 | current_thread = get_lwp_thread (lwp); |
| 2026 | |
| 2027 | if ((wstat == NULL |
| 2028 | || (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) != SIGTRAP)) |
| 2029 | && supports_fast_tracepoints () |
| 2030 | && agent_loaded_p ()) |
| 2031 | { |
| 2032 | struct fast_tpoint_collect_status status; |
| 2033 | |
| 2034 | if (debug_threads) |
| 2035 | debug_printf ("Checking whether LWP %ld needs to move out of the " |
| 2036 | "jump pad.\n", |
| 2037 | lwpid_of (current_thread)); |
| 2038 | |
| 2039 | fast_tpoint_collect_result r |
| 2040 | = linux_fast_tracepoint_collecting (lwp, &status); |
| 2041 | |
| 2042 | if (wstat == NULL |
| 2043 | || (WSTOPSIG (*wstat) != SIGILL |
| 2044 | && WSTOPSIG (*wstat) != SIGFPE |
| 2045 | && WSTOPSIG (*wstat) != SIGSEGV |
| 2046 | && WSTOPSIG (*wstat) != SIGBUS)) |
| 2047 | { |
| 2048 | lwp->collecting_fast_tracepoint = r; |
| 2049 | |
| 2050 | if (r != fast_tpoint_collect_result::not_collecting) |
| 2051 | { |
| 2052 | if (r == fast_tpoint_collect_result::before_insn |
| 2053 | && lwp->exit_jump_pad_bkpt == NULL) |
| 2054 | { |
| 2055 | /* Haven't executed the original instruction yet. |
| 2056 | Set breakpoint there, and wait till it's hit, |
| 2057 | then single-step until exiting the jump pad. */ |
| 2058 | lwp->exit_jump_pad_bkpt |
| 2059 | = set_breakpoint_at (status.adjusted_insn_addr, NULL); |
| 2060 | } |
| 2061 | |
| 2062 | if (debug_threads) |
| 2063 | debug_printf ("Checking whether LWP %ld needs to move out of " |
| 2064 | "the jump pad...it does\n", |
| 2065 | lwpid_of (current_thread)); |
| 2066 | current_thread = saved_thread; |
| 2067 | |
| 2068 | return true; |
| 2069 | } |
| 2070 | } |
| 2071 | else |
| 2072 | { |
| 2073 | /* If we get a synchronous signal while collecting, *and* |
| 2074 | while executing the (relocated) original instruction, |
| 2075 | reset the PC to point at the tpoint address, before |
| 2076 | reporting to GDB. Otherwise, it's an IPA lib bug: just |
| 2077 | report the signal to GDB, and pray for the best. */ |
| 2078 | |
| 2079 | lwp->collecting_fast_tracepoint |
| 2080 | = fast_tpoint_collect_result::not_collecting; |
| 2081 | |
| 2082 | if (r != fast_tpoint_collect_result::not_collecting |
| 2083 | && (status.adjusted_insn_addr <= lwp->stop_pc |
| 2084 | && lwp->stop_pc < status.adjusted_insn_addr_end)) |
| 2085 | { |
| 2086 | siginfo_t info; |
| 2087 | struct regcache *regcache; |
| 2088 | |
| 2089 | /* The si_addr on a few signals references the address |
| 2090 | of the faulting instruction. Adjust that as |
| 2091 | well. */ |
| 2092 | if ((WSTOPSIG (*wstat) == SIGILL |
| 2093 | || WSTOPSIG (*wstat) == SIGFPE |
| 2094 | || WSTOPSIG (*wstat) == SIGBUS |
| 2095 | || WSTOPSIG (*wstat) == SIGSEGV) |
| 2096 | && ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread), |
| 2097 | (PTRACE_TYPE_ARG3) 0, &info) == 0 |
| 2098 | /* Final check just to make sure we don't clobber |
| 2099 | the siginfo of non-kernel-sent signals. */ |
| 2100 | && (uintptr_t) info.si_addr == lwp->stop_pc) |
| 2101 | { |
| 2102 | info.si_addr = (void *) (uintptr_t) status.tpoint_addr; |
| 2103 | ptrace (PTRACE_SETSIGINFO, lwpid_of (current_thread), |
| 2104 | (PTRACE_TYPE_ARG3) 0, &info); |
| 2105 | } |
| 2106 | |
| 2107 | regcache = get_thread_regcache (current_thread, 1); |
| 2108 | low_set_pc (regcache, status.tpoint_addr); |
| 2109 | lwp->stop_pc = status.tpoint_addr; |
| 2110 | |
| 2111 | /* Cancel any fast tracepoint lock this thread was |
| 2112 | holding. */ |
| 2113 | force_unlock_trace_buffer (); |
| 2114 | } |
| 2115 | |
| 2116 | if (lwp->exit_jump_pad_bkpt != NULL) |
| 2117 | { |
| 2118 | if (debug_threads) |
| 2119 | debug_printf ("Cancelling fast exit-jump-pad: removing bkpt. " |
| 2120 | "stopping all threads momentarily.\n"); |
| 2121 | |
| 2122 | stop_all_lwps (1, lwp); |
| 2123 | |
| 2124 | delete_breakpoint (lwp->exit_jump_pad_bkpt); |
| 2125 | lwp->exit_jump_pad_bkpt = NULL; |
| 2126 | |
| 2127 | unstop_all_lwps (1, lwp); |
| 2128 | |
| 2129 | gdb_assert (lwp->suspended >= 0); |
| 2130 | } |
| 2131 | } |
| 2132 | } |
| 2133 | |
| 2134 | if (debug_threads) |
| 2135 | debug_printf ("Checking whether LWP %ld needs to move out of the " |
| 2136 | "jump pad...no\n", |
| 2137 | lwpid_of (current_thread)); |
| 2138 | |
| 2139 | current_thread = saved_thread; |
| 2140 | return false; |
| 2141 | } |
| 2142 | |
| 2143 | /* Enqueue one signal in the "signals to report later when out of the |
| 2144 | jump pad" list. */ |
| 2145 | |
| 2146 | static void |
| 2147 | enqueue_one_deferred_signal (struct lwp_info *lwp, int *wstat) |
| 2148 | { |
| 2149 | struct pending_signals *p_sig; |
| 2150 | struct thread_info *thread = get_lwp_thread (lwp); |
| 2151 | |
| 2152 | if (debug_threads) |
| 2153 | debug_printf ("Deferring signal %d for LWP %ld.\n", |
| 2154 | WSTOPSIG (*wstat), lwpid_of (thread)); |
| 2155 | |
| 2156 | if (debug_threads) |
| 2157 | { |
| 2158 | struct pending_signals *sig; |
| 2159 | |
| 2160 | for (sig = lwp->pending_signals_to_report; |
| 2161 | sig != NULL; |
| 2162 | sig = sig->prev) |
| 2163 | debug_printf (" Already queued %d\n", |
| 2164 | sig->signal); |
| 2165 | |
| 2166 | debug_printf (" (no more currently queued signals)\n"); |
| 2167 | } |
| 2168 | |
| 2169 | /* Don't enqueue non-RT signals if they are already in the deferred |
| 2170 | queue. (SIGSTOP being the easiest signal to see ending up here |
| 2171 | twice) */ |
| 2172 | if (WSTOPSIG (*wstat) < __SIGRTMIN) |
| 2173 | { |
| 2174 | struct pending_signals *sig; |
| 2175 | |
| 2176 | for (sig = lwp->pending_signals_to_report; |
| 2177 | sig != NULL; |
| 2178 | sig = sig->prev) |
| 2179 | { |
| 2180 | if (sig->signal == WSTOPSIG (*wstat)) |
| 2181 | { |
| 2182 | if (debug_threads) |
| 2183 | debug_printf ("Not requeuing already queued non-RT signal %d" |
| 2184 | " for LWP %ld\n", |
| 2185 | sig->signal, |
| 2186 | lwpid_of (thread)); |
| 2187 | return; |
| 2188 | } |
| 2189 | } |
| 2190 | } |
| 2191 | |
| 2192 | p_sig = XCNEW (struct pending_signals); |
| 2193 | p_sig->prev = lwp->pending_signals_to_report; |
| 2194 | p_sig->signal = WSTOPSIG (*wstat); |
| 2195 | |
| 2196 | ptrace (PTRACE_GETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0, |
| 2197 | &p_sig->info); |
| 2198 | |
| 2199 | lwp->pending_signals_to_report = p_sig; |
| 2200 | } |
| 2201 | |
| 2202 | /* Dequeue one signal from the "signals to report later when out of |
| 2203 | the jump pad" list. */ |
| 2204 | |
| 2205 | static int |
| 2206 | dequeue_one_deferred_signal (struct lwp_info *lwp, int *wstat) |
| 2207 | { |
| 2208 | struct thread_info *thread = get_lwp_thread (lwp); |
| 2209 | |
| 2210 | if (lwp->pending_signals_to_report != NULL) |
| 2211 | { |
| 2212 | struct pending_signals **p_sig; |
| 2213 | |
| 2214 | p_sig = &lwp->pending_signals_to_report; |
| 2215 | while ((*p_sig)->prev != NULL) |
| 2216 | p_sig = &(*p_sig)->prev; |
| 2217 | |
| 2218 | *wstat = W_STOPCODE ((*p_sig)->signal); |
| 2219 | if ((*p_sig)->info.si_signo != 0) |
| 2220 | ptrace (PTRACE_SETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0, |
| 2221 | &(*p_sig)->info); |
| 2222 | free (*p_sig); |
| 2223 | *p_sig = NULL; |
| 2224 | |
| 2225 | if (debug_threads) |
| 2226 | debug_printf ("Reporting deferred signal %d for LWP %ld.\n", |
| 2227 | WSTOPSIG (*wstat), lwpid_of (thread)); |
| 2228 | |
| 2229 | if (debug_threads) |
| 2230 | { |
| 2231 | struct pending_signals *sig; |
| 2232 | |
| 2233 | for (sig = lwp->pending_signals_to_report; |
| 2234 | sig != NULL; |
| 2235 | sig = sig->prev) |
| 2236 | debug_printf (" Still queued %d\n", |
| 2237 | sig->signal); |
| 2238 | |
| 2239 | debug_printf (" (no more queued signals)\n"); |
| 2240 | } |
| 2241 | |
| 2242 | return 1; |
| 2243 | } |
| 2244 | |
| 2245 | return 0; |
| 2246 | } |
| 2247 | |
| 2248 | /* Fetch the possibly triggered data watchpoint info and store it in |
| 2249 | CHILD. |
| 2250 | |
| 2251 | On some archs, like x86, that use debug registers to set |
| 2252 | watchpoints, it's possible that the way to know which watched |
| 2253 | address trapped, is to check the register that is used to select |
| 2254 | which address to watch. Problem is, between setting the watchpoint |
| 2255 | and reading back which data address trapped, the user may change |
| 2256 | the set of watchpoints, and, as a consequence, GDB changes the |
| 2257 | debug registers in the inferior. To avoid reading back a stale |
| 2258 | stopped-data-address when that happens, we cache in LP the fact |
| 2259 | that a watchpoint trapped, and the corresponding data address, as |
| 2260 | soon as we see CHILD stop with a SIGTRAP. If GDB changes the debug |
| 2261 | registers meanwhile, we have the cached data we can rely on. */ |
| 2262 | |
| 2263 | static int |
| 2264 | check_stopped_by_watchpoint (struct lwp_info *child) |
| 2265 | { |
| 2266 | if (the_low_target.stopped_by_watchpoint != NULL) |
| 2267 | { |
| 2268 | struct thread_info *saved_thread; |
| 2269 | |
| 2270 | saved_thread = current_thread; |
| 2271 | current_thread = get_lwp_thread (child); |
| 2272 | |
| 2273 | if (the_low_target.stopped_by_watchpoint ()) |
| 2274 | { |
| 2275 | child->stop_reason = TARGET_STOPPED_BY_WATCHPOINT; |
| 2276 | |
| 2277 | if (the_low_target.stopped_data_address != NULL) |
| 2278 | child->stopped_data_address |
| 2279 | = the_low_target.stopped_data_address (); |
| 2280 | else |
| 2281 | child->stopped_data_address = 0; |
| 2282 | } |
| 2283 | |
| 2284 | current_thread = saved_thread; |
| 2285 | } |
| 2286 | |
| 2287 | return child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
| 2288 | } |
| 2289 | |
| 2290 | /* Return the ptrace options that we want to try to enable. */ |
| 2291 | |
| 2292 | static int |
| 2293 | linux_low_ptrace_options (int attached) |
| 2294 | { |
| 2295 | client_state &cs = get_client_state (); |
| 2296 | int options = 0; |
| 2297 | |
| 2298 | if (!attached) |
| 2299 | options |= PTRACE_O_EXITKILL; |
| 2300 | |
| 2301 | if (cs.report_fork_events) |
| 2302 | options |= PTRACE_O_TRACEFORK; |
| 2303 | |
| 2304 | if (cs.report_vfork_events) |
| 2305 | options |= (PTRACE_O_TRACEVFORK | PTRACE_O_TRACEVFORKDONE); |
| 2306 | |
| 2307 | if (cs.report_exec_events) |
| 2308 | options |= PTRACE_O_TRACEEXEC; |
| 2309 | |
| 2310 | options |= PTRACE_O_TRACESYSGOOD; |
| 2311 | |
| 2312 | return options; |
| 2313 | } |
| 2314 | |
| 2315 | lwp_info * |
| 2316 | linux_process_target::filter_event (int lwpid, int wstat) |
| 2317 | { |
| 2318 | client_state &cs = get_client_state (); |
| 2319 | struct lwp_info *child; |
| 2320 | struct thread_info *thread; |
| 2321 | int have_stop_pc = 0; |
| 2322 | |
| 2323 | child = find_lwp_pid (ptid_t (lwpid)); |
| 2324 | |
| 2325 | /* Check for stop events reported by a process we didn't already |
| 2326 | know about - anything not already in our LWP list. |
| 2327 | |
| 2328 | If we're expecting to receive stopped processes after |
| 2329 | fork, vfork, and clone events, then we'll just add the |
| 2330 | new one to our list and go back to waiting for the event |
| 2331 | to be reported - the stopped process might be returned |
| 2332 | from waitpid before or after the event is. |
| 2333 | |
| 2334 | But note the case of a non-leader thread exec'ing after the |
| 2335 | leader having exited, and gone from our lists (because |
| 2336 | check_zombie_leaders deleted it). The non-leader thread |
| 2337 | changes its tid to the tgid. */ |
| 2338 | |
| 2339 | if (WIFSTOPPED (wstat) && child == NULL && WSTOPSIG (wstat) == SIGTRAP |
| 2340 | && linux_ptrace_get_extended_event (wstat) == PTRACE_EVENT_EXEC) |
| 2341 | { |
| 2342 | ptid_t child_ptid; |
| 2343 | |
| 2344 | /* A multi-thread exec after we had seen the leader exiting. */ |
| 2345 | if (debug_threads) |
| 2346 | { |
| 2347 | debug_printf ("LLW: Re-adding thread group leader LWP %d" |
| 2348 | "after exec.\n", lwpid); |
| 2349 | } |
| 2350 | |
| 2351 | child_ptid = ptid_t (lwpid, lwpid, 0); |
| 2352 | child = add_lwp (child_ptid); |
| 2353 | child->stopped = 1; |
| 2354 | current_thread = child->thread; |
| 2355 | } |
| 2356 | |
| 2357 | /* If we didn't find a process, one of two things presumably happened: |
| 2358 | - A process we started and then detached from has exited. Ignore it. |
| 2359 | - A process we are controlling has forked and the new child's stop |
| 2360 | was reported to us by the kernel. Save its PID. */ |
| 2361 | if (child == NULL && WIFSTOPPED (wstat)) |
| 2362 | { |
| 2363 | add_to_pid_list (&stopped_pids, lwpid, wstat); |
| 2364 | return NULL; |
| 2365 | } |
| 2366 | else if (child == NULL) |
| 2367 | return NULL; |
| 2368 | |
| 2369 | thread = get_lwp_thread (child); |
| 2370 | |
| 2371 | child->stopped = 1; |
| 2372 | |
| 2373 | child->last_status = wstat; |
| 2374 | |
| 2375 | /* Check if the thread has exited. */ |
| 2376 | if ((WIFEXITED (wstat) || WIFSIGNALED (wstat))) |
| 2377 | { |
| 2378 | if (debug_threads) |
| 2379 | debug_printf ("LLFE: %d exited.\n", lwpid); |
| 2380 | |
| 2381 | if (finish_step_over (child)) |
| 2382 | { |
| 2383 | /* Unsuspend all other LWPs, and set them back running again. */ |
| 2384 | unsuspend_all_lwps (child); |
| 2385 | } |
| 2386 | |
| 2387 | /* If there is at least one more LWP, then the exit signal was |
| 2388 | not the end of the debugged application and should be |
| 2389 | ignored, unless GDB wants to hear about thread exits. */ |
| 2390 | if (cs.report_thread_events |
| 2391 | || last_thread_of_process_p (pid_of (thread))) |
| 2392 | { |
| 2393 | /* Since events are serialized to GDB core, and we can't |
| 2394 | report this one right now. Leave the status pending for |
| 2395 | the next time we're able to report it. */ |
| 2396 | mark_lwp_dead (child, wstat); |
| 2397 | return child; |
| 2398 | } |
| 2399 | else |
| 2400 | { |
| 2401 | delete_lwp (child); |
| 2402 | return NULL; |
| 2403 | } |
| 2404 | } |
| 2405 | |
| 2406 | gdb_assert (WIFSTOPPED (wstat)); |
| 2407 | |
| 2408 | if (WIFSTOPPED (wstat)) |
| 2409 | { |
| 2410 | struct process_info *proc; |
| 2411 | |
| 2412 | /* Architecture-specific setup after inferior is running. */ |
| 2413 | proc = find_process_pid (pid_of (thread)); |
| 2414 | if (proc->tdesc == NULL) |
| 2415 | { |
| 2416 | if (proc->attached) |
| 2417 | { |
| 2418 | /* This needs to happen after we have attached to the |
| 2419 | inferior and it is stopped for the first time, but |
| 2420 | before we access any inferior registers. */ |
| 2421 | arch_setup_thread (thread); |
| 2422 | } |
| 2423 | else |
| 2424 | { |
| 2425 | /* The process is started, but GDBserver will do |
| 2426 | architecture-specific setup after the program stops at |
| 2427 | the first instruction. */ |
| 2428 | child->status_pending_p = 1; |
| 2429 | child->status_pending = wstat; |
| 2430 | return child; |
| 2431 | } |
| 2432 | } |
| 2433 | } |
| 2434 | |
| 2435 | if (WIFSTOPPED (wstat) && child->must_set_ptrace_flags) |
| 2436 | { |
| 2437 | struct process_info *proc = find_process_pid (pid_of (thread)); |
| 2438 | int options = linux_low_ptrace_options (proc->attached); |
| 2439 | |
| 2440 | linux_enable_event_reporting (lwpid, options); |
| 2441 | child->must_set_ptrace_flags = 0; |
| 2442 | } |
| 2443 | |
| 2444 | /* Always update syscall_state, even if it will be filtered later. */ |
| 2445 | if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SYSCALL_SIGTRAP) |
| 2446 | { |
| 2447 | child->syscall_state |
| 2448 | = (child->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY |
| 2449 | ? TARGET_WAITKIND_SYSCALL_RETURN |
| 2450 | : TARGET_WAITKIND_SYSCALL_ENTRY); |
| 2451 | } |
| 2452 | else |
| 2453 | { |
| 2454 | /* Almost all other ptrace-stops are known to be outside of system |
| 2455 | calls, with further exceptions in handle_extended_wait. */ |
| 2456 | child->syscall_state = TARGET_WAITKIND_IGNORE; |
| 2457 | } |
| 2458 | |
| 2459 | /* Be careful to not overwrite stop_pc until save_stop_reason is |
| 2460 | called. */ |
| 2461 | if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP |
| 2462 | && linux_is_extended_waitstatus (wstat)) |
| 2463 | { |
| 2464 | child->stop_pc = get_pc (child); |
| 2465 | if (handle_extended_wait (&child, wstat)) |
| 2466 | { |
| 2467 | /* The event has been handled, so just return without |
| 2468 | reporting it. */ |
| 2469 | return NULL; |
| 2470 | } |
| 2471 | } |
| 2472 | |
| 2473 | if (linux_wstatus_maybe_breakpoint (wstat)) |
| 2474 | { |
| 2475 | if (save_stop_reason (child)) |
| 2476 | have_stop_pc = 1; |
| 2477 | } |
| 2478 | |
| 2479 | if (!have_stop_pc) |
| 2480 | child->stop_pc = get_pc (child); |
| 2481 | |
| 2482 | if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGSTOP |
| 2483 | && child->stop_expected) |
| 2484 | { |
| 2485 | if (debug_threads) |
| 2486 | debug_printf ("Expected stop.\n"); |
| 2487 | child->stop_expected = 0; |
| 2488 | |
| 2489 | if (thread->last_resume_kind == resume_stop) |
| 2490 | { |
| 2491 | /* We want to report the stop to the core. Treat the |
| 2492 | SIGSTOP as a normal event. */ |
| 2493 | if (debug_threads) |
| 2494 | debug_printf ("LLW: resume_stop SIGSTOP caught for %s.\n", |
| 2495 | target_pid_to_str (ptid_of (thread))); |
| 2496 | } |
| 2497 | else if (stopping_threads != NOT_STOPPING_THREADS) |
| 2498 | { |
| 2499 | /* Stopping threads. We don't want this SIGSTOP to end up |
| 2500 | pending. */ |
| 2501 | if (debug_threads) |
| 2502 | debug_printf ("LLW: SIGSTOP caught for %s " |
| 2503 | "while stopping threads.\n", |
| 2504 | target_pid_to_str (ptid_of (thread))); |
| 2505 | return NULL; |
| 2506 | } |
| 2507 | else |
| 2508 | { |
| 2509 | /* This is a delayed SIGSTOP. Filter out the event. */ |
| 2510 | if (debug_threads) |
| 2511 | debug_printf ("LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n", |
| 2512 | child->stepping ? "step" : "continue", |
| 2513 | target_pid_to_str (ptid_of (thread))); |
| 2514 | |
| 2515 | resume_one_lwp (child, child->stepping, 0, NULL); |
| 2516 | return NULL; |
| 2517 | } |
| 2518 | } |
| 2519 | |
| 2520 | child->status_pending_p = 1; |
| 2521 | child->status_pending = wstat; |
| 2522 | return child; |
| 2523 | } |
| 2524 | |
| 2525 | /* Return true if THREAD is doing hardware single step. */ |
| 2526 | |
| 2527 | static int |
| 2528 | maybe_hw_step (struct thread_info *thread) |
| 2529 | { |
| 2530 | if (can_hardware_single_step ()) |
| 2531 | return 1; |
| 2532 | else |
| 2533 | { |
| 2534 | /* GDBserver must insert single-step breakpoint for software |
| 2535 | single step. */ |
| 2536 | gdb_assert (has_single_step_breakpoints (thread)); |
| 2537 | return 0; |
| 2538 | } |
| 2539 | } |
| 2540 | |
| 2541 | void |
| 2542 | linux_process_target::resume_stopped_resumed_lwps (thread_info *thread) |
| 2543 | { |
| 2544 | struct lwp_info *lp = get_thread_lwp (thread); |
| 2545 | |
| 2546 | if (lp->stopped |
| 2547 | && !lp->suspended |
| 2548 | && !lp->status_pending_p |
| 2549 | && thread->last_status.kind == TARGET_WAITKIND_IGNORE) |
| 2550 | { |
| 2551 | int step = 0; |
| 2552 | |
| 2553 | if (thread->last_resume_kind == resume_step) |
| 2554 | step = maybe_hw_step (thread); |
| 2555 | |
| 2556 | if (debug_threads) |
| 2557 | debug_printf ("RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n", |
| 2558 | target_pid_to_str (ptid_of (thread)), |
| 2559 | paddress (lp->stop_pc), |
| 2560 | step); |
| 2561 | |
| 2562 | resume_one_lwp (lp, step, GDB_SIGNAL_0, NULL); |
| 2563 | } |
| 2564 | } |
| 2565 | |
| 2566 | int |
| 2567 | linux_process_target::wait_for_event_filtered (ptid_t wait_ptid, |
| 2568 | ptid_t filter_ptid, |
| 2569 | int *wstatp, int options) |
| 2570 | { |
| 2571 | struct thread_info *event_thread; |
| 2572 | struct lwp_info *event_child, *requested_child; |
| 2573 | sigset_t block_mask, prev_mask; |
| 2574 | |
| 2575 | retry: |
| 2576 | /* N.B. event_thread points to the thread_info struct that contains |
| 2577 | event_child. Keep them in sync. */ |
| 2578 | event_thread = NULL; |
| 2579 | event_child = NULL; |
| 2580 | requested_child = NULL; |
| 2581 | |
| 2582 | /* Check for a lwp with a pending status. */ |
| 2583 | |
| 2584 | if (filter_ptid == minus_one_ptid || filter_ptid.is_pid ()) |
| 2585 | { |
| 2586 | event_thread = find_thread_in_random ([&] (thread_info *thread) |
| 2587 | { |
| 2588 | return status_pending_p_callback (thread, filter_ptid); |
| 2589 | }); |
| 2590 | |
| 2591 | if (event_thread != NULL) |
| 2592 | event_child = get_thread_lwp (event_thread); |
| 2593 | if (debug_threads && event_thread) |
| 2594 | debug_printf ("Got a pending child %ld\n", lwpid_of (event_thread)); |
| 2595 | } |
| 2596 | else if (filter_ptid != null_ptid) |
| 2597 | { |
| 2598 | requested_child = find_lwp_pid (filter_ptid); |
| 2599 | |
| 2600 | if (stopping_threads == NOT_STOPPING_THREADS |
| 2601 | && requested_child->status_pending_p |
| 2602 | && (requested_child->collecting_fast_tracepoint |
| 2603 | != fast_tpoint_collect_result::not_collecting)) |
| 2604 | { |
| 2605 | enqueue_one_deferred_signal (requested_child, |
| 2606 | &requested_child->status_pending); |
| 2607 | requested_child->status_pending_p = 0; |
| 2608 | requested_child->status_pending = 0; |
| 2609 | resume_one_lwp (requested_child, 0, 0, NULL); |
| 2610 | } |
| 2611 | |
| 2612 | if (requested_child->suspended |
| 2613 | && requested_child->status_pending_p) |
| 2614 | { |
| 2615 | internal_error (__FILE__, __LINE__, |
| 2616 | "requesting an event out of a" |
| 2617 | " suspended child?"); |
| 2618 | } |
| 2619 | |
| 2620 | if (requested_child->status_pending_p) |
| 2621 | { |
| 2622 | event_child = requested_child; |
| 2623 | event_thread = get_lwp_thread (event_child); |
| 2624 | } |
| 2625 | } |
| 2626 | |
| 2627 | if (event_child != NULL) |
| 2628 | { |
| 2629 | if (debug_threads) |
| 2630 | debug_printf ("Got an event from pending child %ld (%04x)\n", |
| 2631 | lwpid_of (event_thread), event_child->status_pending); |
| 2632 | *wstatp = event_child->status_pending; |
| 2633 | event_child->status_pending_p = 0; |
| 2634 | event_child->status_pending = 0; |
| 2635 | current_thread = event_thread; |
| 2636 | return lwpid_of (event_thread); |
| 2637 | } |
| 2638 | |
| 2639 | /* But if we don't find a pending event, we'll have to wait. |
| 2640 | |
| 2641 | We only enter this loop if no process has a pending wait status. |
| 2642 | Thus any action taken in response to a wait status inside this |
| 2643 | loop is responding as soon as we detect the status, not after any |
| 2644 | pending events. */ |
| 2645 | |
| 2646 | /* Make sure SIGCHLD is blocked until the sigsuspend below. Block |
| 2647 | all signals while here. */ |
| 2648 | sigfillset (&block_mask); |
| 2649 | gdb_sigmask (SIG_BLOCK, &block_mask, &prev_mask); |
| 2650 | |
| 2651 | /* Always pull all events out of the kernel. We'll randomly select |
| 2652 | an event LWP out of all that have events, to prevent |
| 2653 | starvation. */ |
| 2654 | while (event_child == NULL) |
| 2655 | { |
| 2656 | pid_t ret = 0; |
| 2657 | |
| 2658 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
| 2659 | quirks: |
| 2660 | |
| 2661 | - If the thread group leader exits while other threads in the |
| 2662 | thread group still exist, waitpid(TGID, ...) hangs. That |
| 2663 | waitpid won't return an exit status until the other threads |
| 2664 | in the group are reaped. |
| 2665 | |
| 2666 | - When a non-leader thread execs, that thread just vanishes |
| 2667 | without reporting an exit (so we'd hang if we waited for it |
| 2668 | explicitly in that case). The exec event is reported to |
| 2669 | the TGID pid. */ |
| 2670 | errno = 0; |
| 2671 | ret = my_waitpid (-1, wstatp, options | WNOHANG); |
| 2672 | |
| 2673 | if (debug_threads) |
| 2674 | debug_printf ("LWFE: waitpid(-1, ...) returned %d, %s\n", |
| 2675 | ret, errno ? safe_strerror (errno) : "ERRNO-OK"); |
| 2676 | |
| 2677 | if (ret > 0) |
| 2678 | { |
| 2679 | if (debug_threads) |
| 2680 | { |
| 2681 | debug_printf ("LLW: waitpid %ld received %s\n", |
| 2682 | (long) ret, status_to_str (*wstatp)); |
| 2683 | } |
| 2684 | |
| 2685 | /* Filter all events. IOW, leave all events pending. We'll |
| 2686 | randomly select an event LWP out of all that have events |
| 2687 | below. */ |
| 2688 | filter_event (ret, *wstatp); |
| 2689 | /* Retry until nothing comes out of waitpid. A single |
| 2690 | SIGCHLD can indicate more than one child stopped. */ |
| 2691 | continue; |
| 2692 | } |
| 2693 | |
| 2694 | /* Now that we've pulled all events out of the kernel, resume |
| 2695 | LWPs that don't have an interesting event to report. */ |
| 2696 | if (stopping_threads == NOT_STOPPING_THREADS) |
| 2697 | for_each_thread ([this] (thread_info *thread) |
| 2698 | { |
| 2699 | resume_stopped_resumed_lwps (thread); |
| 2700 | }); |
| 2701 | |
| 2702 | /* ... and find an LWP with a status to report to the core, if |
| 2703 | any. */ |
| 2704 | event_thread = find_thread_in_random ([&] (thread_info *thread) |
| 2705 | { |
| 2706 | return status_pending_p_callback (thread, filter_ptid); |
| 2707 | }); |
| 2708 | |
| 2709 | if (event_thread != NULL) |
| 2710 | { |
| 2711 | event_child = get_thread_lwp (event_thread); |
| 2712 | *wstatp = event_child->status_pending; |
| 2713 | event_child->status_pending_p = 0; |
| 2714 | event_child->status_pending = 0; |
| 2715 | break; |
| 2716 | } |
| 2717 | |
| 2718 | /* Check for zombie thread group leaders. Those can't be reaped |
| 2719 | until all other threads in the thread group are. */ |
| 2720 | check_zombie_leaders (); |
| 2721 | |
| 2722 | auto not_stopped = [&] (thread_info *thread) |
| 2723 | { |
| 2724 | return not_stopped_callback (thread, wait_ptid); |
| 2725 | }; |
| 2726 | |
| 2727 | /* If there are no resumed children left in the set of LWPs we |
| 2728 | want to wait for, bail. We can't just block in |
| 2729 | waitpid/sigsuspend, because lwps might have been left stopped |
| 2730 | in trace-stop state, and we'd be stuck forever waiting for |
| 2731 | their status to change (which would only happen if we resumed |
| 2732 | them). Even if WNOHANG is set, this return code is preferred |
| 2733 | over 0 (below), as it is more detailed. */ |
| 2734 | if (find_thread (not_stopped) == NULL) |
| 2735 | { |
| 2736 | if (debug_threads) |
| 2737 | debug_printf ("LLW: exit (no unwaited-for LWP)\n"); |
| 2738 | gdb_sigmask (SIG_SETMASK, &prev_mask, NULL); |
| 2739 | return -1; |
| 2740 | } |
| 2741 | |
| 2742 | /* No interesting event to report to the caller. */ |
| 2743 | if ((options & WNOHANG)) |
| 2744 | { |
| 2745 | if (debug_threads) |
| 2746 | debug_printf ("WNOHANG set, no event found\n"); |
| 2747 | |
| 2748 | gdb_sigmask (SIG_SETMASK, &prev_mask, NULL); |
| 2749 | return 0; |
| 2750 | } |
| 2751 | |
| 2752 | /* Block until we get an event reported with SIGCHLD. */ |
| 2753 | if (debug_threads) |
| 2754 | debug_printf ("sigsuspend'ing\n"); |
| 2755 | |
| 2756 | sigsuspend (&prev_mask); |
| 2757 | gdb_sigmask (SIG_SETMASK, &prev_mask, NULL); |
| 2758 | goto retry; |
| 2759 | } |
| 2760 | |
| 2761 | gdb_sigmask (SIG_SETMASK, &prev_mask, NULL); |
| 2762 | |
| 2763 | current_thread = event_thread; |
| 2764 | |
| 2765 | return lwpid_of (event_thread); |
| 2766 | } |
| 2767 | |
| 2768 | int |
| 2769 | linux_process_target::wait_for_event (ptid_t ptid, int *wstatp, int options) |
| 2770 | { |
| 2771 | return wait_for_event_filtered (ptid, ptid, wstatp, options); |
| 2772 | } |
| 2773 | |
| 2774 | /* Select one LWP out of those that have events pending. */ |
| 2775 | |
| 2776 | static void |
| 2777 | select_event_lwp (struct lwp_info **orig_lp) |
| 2778 | { |
| 2779 | struct thread_info *event_thread = NULL; |
| 2780 | |
| 2781 | /* In all-stop, give preference to the LWP that is being |
| 2782 | single-stepped. There will be at most one, and it's the LWP that |
| 2783 | the core is most interested in. If we didn't do this, then we'd |
| 2784 | have to handle pending step SIGTRAPs somehow in case the core |
| 2785 | later continues the previously-stepped thread, otherwise we'd |
| 2786 | report the pending SIGTRAP, and the core, not having stepped the |
| 2787 | thread, wouldn't understand what the trap was for, and therefore |
| 2788 | would report it to the user as a random signal. */ |
| 2789 | if (!non_stop) |
| 2790 | { |
| 2791 | event_thread = find_thread ([] (thread_info *thread) |
| 2792 | { |
| 2793 | lwp_info *lp = get_thread_lwp (thread); |
| 2794 | |
| 2795 | return (thread->last_status.kind == TARGET_WAITKIND_IGNORE |
| 2796 | && thread->last_resume_kind == resume_step |
| 2797 | && lp->status_pending_p); |
| 2798 | }); |
| 2799 | |
| 2800 | if (event_thread != NULL) |
| 2801 | { |
| 2802 | if (debug_threads) |
| 2803 | debug_printf ("SEL: Select single-step %s\n", |
| 2804 | target_pid_to_str (ptid_of (event_thread))); |
| 2805 | } |
| 2806 | } |
| 2807 | if (event_thread == NULL) |
| 2808 | { |
| 2809 | /* No single-stepping LWP. Select one at random, out of those |
| 2810 | which have had events. */ |
| 2811 | |
| 2812 | event_thread = find_thread_in_random ([&] (thread_info *thread) |
| 2813 | { |
| 2814 | lwp_info *lp = get_thread_lwp (thread); |
| 2815 | |
| 2816 | /* Only resumed LWPs that have an event pending. */ |
| 2817 | return (thread->last_status.kind == TARGET_WAITKIND_IGNORE |
| 2818 | && lp->status_pending_p); |
| 2819 | }); |
| 2820 | } |
| 2821 | |
| 2822 | if (event_thread != NULL) |
| 2823 | { |
| 2824 | struct lwp_info *event_lp = get_thread_lwp (event_thread); |
| 2825 | |
| 2826 | /* Switch the event LWP. */ |
| 2827 | *orig_lp = event_lp; |
| 2828 | } |
| 2829 | } |
| 2830 | |
| 2831 | /* Decrement the suspend count of all LWPs, except EXCEPT, if non |
| 2832 | NULL. */ |
| 2833 | |
| 2834 | static void |
| 2835 | unsuspend_all_lwps (struct lwp_info *except) |
| 2836 | { |
| 2837 | for_each_thread ([&] (thread_info *thread) |
| 2838 | { |
| 2839 | lwp_info *lwp = get_thread_lwp (thread); |
| 2840 | |
| 2841 | if (lwp != except) |
| 2842 | lwp_suspended_decr (lwp); |
| 2843 | }); |
| 2844 | } |
| 2845 | |
| 2846 | static bool stuck_in_jump_pad_callback (thread_info *thread); |
| 2847 | static bool lwp_running (thread_info *thread); |
| 2848 | |
| 2849 | /* Stabilize threads (move out of jump pads). |
| 2850 | |
| 2851 | If a thread is midway collecting a fast tracepoint, we need to |
| 2852 | finish the collection and move it out of the jump pad before |
| 2853 | reporting the signal. |
| 2854 | |
| 2855 | This avoids recursion while collecting (when a signal arrives |
| 2856 | midway, and the signal handler itself collects), which would trash |
| 2857 | the trace buffer. In case the user set a breakpoint in a signal |
| 2858 | handler, this avoids the backtrace showing the jump pad, etc.. |
| 2859 | Most importantly, there are certain things we can't do safely if |
| 2860 | threads are stopped in a jump pad (or in its callee's). For |
| 2861 | example: |
| 2862 | |
| 2863 | - starting a new trace run. A thread still collecting the |
| 2864 | previous run, could trash the trace buffer when resumed. The trace |
| 2865 | buffer control structures would have been reset but the thread had |
| 2866 | no way to tell. The thread could even midway memcpy'ing to the |
| 2867 | buffer, which would mean that when resumed, it would clobber the |
| 2868 | trace buffer that had been set for a new run. |
| 2869 | |
| 2870 | - we can't rewrite/reuse the jump pads for new tracepoints |
| 2871 | safely. Say you do tstart while a thread is stopped midway while |
| 2872 | collecting. When the thread is later resumed, it finishes the |
| 2873 | collection, and returns to the jump pad, to execute the original |
| 2874 | instruction that was under the tracepoint jump at the time the |
| 2875 | older run had been started. If the jump pad had been rewritten |
| 2876 | since for something else in the new run, the thread would now |
| 2877 | execute the wrong / random instructions. */ |
| 2878 | |
| 2879 | void |
| 2880 | linux_process_target::stabilize_threads () |
| 2881 | { |
| 2882 | thread_info *thread_stuck = find_thread (stuck_in_jump_pad_callback); |
| 2883 | |
| 2884 | if (thread_stuck != NULL) |
| 2885 | { |
| 2886 | if (debug_threads) |
| 2887 | debug_printf ("can't stabilize, LWP %ld is stuck in jump pad\n", |
| 2888 | lwpid_of (thread_stuck)); |
| 2889 | return; |
| 2890 | } |
| 2891 | |
| 2892 | thread_info *saved_thread = current_thread; |
| 2893 | |
| 2894 | stabilizing_threads = 1; |
| 2895 | |
| 2896 | /* Kick 'em all. */ |
| 2897 | for_each_thread ([this] (thread_info *thread) |
| 2898 | { |
| 2899 | move_out_of_jump_pad (thread); |
| 2900 | }); |
| 2901 | |
| 2902 | /* Loop until all are stopped out of the jump pads. */ |
| 2903 | while (find_thread (lwp_running) != NULL) |
| 2904 | { |
| 2905 | struct target_waitstatus ourstatus; |
| 2906 | struct lwp_info *lwp; |
| 2907 | int wstat; |
| 2908 | |
| 2909 | /* Note that we go through the full wait even loop. While |
| 2910 | moving threads out of jump pad, we need to be able to step |
| 2911 | over internal breakpoints and such. */ |
| 2912 | wait_1 (minus_one_ptid, &ourstatus, 0); |
| 2913 | |
| 2914 | if (ourstatus.kind == TARGET_WAITKIND_STOPPED) |
| 2915 | { |
| 2916 | lwp = get_thread_lwp (current_thread); |
| 2917 | |
| 2918 | /* Lock it. */ |
| 2919 | lwp_suspended_inc (lwp); |
| 2920 | |
| 2921 | if (ourstatus.value.sig != GDB_SIGNAL_0 |
| 2922 | || current_thread->last_resume_kind == resume_stop) |
| 2923 | { |
| 2924 | wstat = W_STOPCODE (gdb_signal_to_host (ourstatus.value.sig)); |
| 2925 | enqueue_one_deferred_signal (lwp, &wstat); |
| 2926 | } |
| 2927 | } |
| 2928 | } |
| 2929 | |
| 2930 | unsuspend_all_lwps (NULL); |
| 2931 | |
| 2932 | stabilizing_threads = 0; |
| 2933 | |
| 2934 | current_thread = saved_thread; |
| 2935 | |
| 2936 | if (debug_threads) |
| 2937 | { |
| 2938 | thread_stuck = find_thread (stuck_in_jump_pad_callback); |
| 2939 | |
| 2940 | if (thread_stuck != NULL) |
| 2941 | debug_printf ("couldn't stabilize, LWP %ld got stuck in jump pad\n", |
| 2942 | lwpid_of (thread_stuck)); |
| 2943 | } |
| 2944 | } |
| 2945 | |
| 2946 | /* Convenience function that is called when the kernel reports an |
| 2947 | event that is not passed out to GDB. */ |
| 2948 | |
| 2949 | static ptid_t |
| 2950 | ignore_event (struct target_waitstatus *ourstatus) |
| 2951 | { |
| 2952 | /* If we got an event, there may still be others, as a single |
| 2953 | SIGCHLD can indicate more than one child stopped. This forces |
| 2954 | another target_wait call. */ |
| 2955 | async_file_mark (); |
| 2956 | |
| 2957 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
| 2958 | return null_ptid; |
| 2959 | } |
| 2960 | |
| 2961 | /* Convenience function that is called when the kernel reports an exit |
| 2962 | event. This decides whether to report the event to GDB as a |
| 2963 | process exit event, a thread exit event, or to suppress the |
| 2964 | event. */ |
| 2965 | |
| 2966 | static ptid_t |
| 2967 | filter_exit_event (struct lwp_info *event_child, |
| 2968 | struct target_waitstatus *ourstatus) |
| 2969 | { |
| 2970 | client_state &cs = get_client_state (); |
| 2971 | struct thread_info *thread = get_lwp_thread (event_child); |
| 2972 | ptid_t ptid = ptid_of (thread); |
| 2973 | |
| 2974 | if (!last_thread_of_process_p (pid_of (thread))) |
| 2975 | { |
| 2976 | if (cs.report_thread_events) |
| 2977 | ourstatus->kind = TARGET_WAITKIND_THREAD_EXITED; |
| 2978 | else |
| 2979 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
| 2980 | |
| 2981 | delete_lwp (event_child); |
| 2982 | } |
| 2983 | return ptid; |
| 2984 | } |
| 2985 | |
| 2986 | /* Returns 1 if GDB is interested in any event_child syscalls. */ |
| 2987 | |
| 2988 | static int |
| 2989 | gdb_catching_syscalls_p (struct lwp_info *event_child) |
| 2990 | { |
| 2991 | struct thread_info *thread = get_lwp_thread (event_child); |
| 2992 | struct process_info *proc = get_thread_process (thread); |
| 2993 | |
| 2994 | return !proc->syscalls_to_catch.empty (); |
| 2995 | } |
| 2996 | |
| 2997 | /* Returns 1 if GDB is interested in the event_child syscall. |
| 2998 | Only to be called when stopped reason is SYSCALL_SIGTRAP. */ |
| 2999 | |
| 3000 | static int |
| 3001 | gdb_catch_this_syscall_p (struct lwp_info *event_child) |
| 3002 | { |
| 3003 | int sysno; |
| 3004 | struct thread_info *thread = get_lwp_thread (event_child); |
| 3005 | struct process_info *proc = get_thread_process (thread); |
| 3006 | |
| 3007 | if (proc->syscalls_to_catch.empty ()) |
| 3008 | return 0; |
| 3009 | |
| 3010 | if (proc->syscalls_to_catch[0] == ANY_SYSCALL) |
| 3011 | return 1; |
| 3012 | |
| 3013 | get_syscall_trapinfo (event_child, &sysno); |
| 3014 | |
| 3015 | for (int iter : proc->syscalls_to_catch) |
| 3016 | if (iter == sysno) |
| 3017 | return 1; |
| 3018 | |
| 3019 | return 0; |
| 3020 | } |
| 3021 | |
| 3022 | ptid_t |
| 3023 | linux_process_target::wait_1 (ptid_t ptid, target_waitstatus *ourstatus, |
| 3024 | int target_options) |
| 3025 | { |
| 3026 | client_state &cs = get_client_state (); |
| 3027 | int w; |
| 3028 | struct lwp_info *event_child; |
| 3029 | int options; |
| 3030 | int pid; |
| 3031 | int step_over_finished; |
| 3032 | int bp_explains_trap; |
| 3033 | int maybe_internal_trap; |
| 3034 | int report_to_gdb; |
| 3035 | int trace_event; |
| 3036 | int in_step_range; |
| 3037 | int any_resumed; |
| 3038 | |
| 3039 | if (debug_threads) |
| 3040 | { |
| 3041 | debug_enter (); |
| 3042 | debug_printf ("wait_1: [%s]\n", target_pid_to_str (ptid)); |
| 3043 | } |
| 3044 | |
| 3045 | /* Translate generic target options into linux options. */ |
| 3046 | options = __WALL; |
| 3047 | if (target_options & TARGET_WNOHANG) |
| 3048 | options |= WNOHANG; |
| 3049 | |
| 3050 | bp_explains_trap = 0; |
| 3051 | trace_event = 0; |
| 3052 | in_step_range = 0; |
| 3053 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
| 3054 | |
| 3055 | auto status_pending_p_any = [&] (thread_info *thread) |
| 3056 | { |
| 3057 | return status_pending_p_callback (thread, minus_one_ptid); |
| 3058 | }; |
| 3059 | |
| 3060 | auto not_stopped = [&] (thread_info *thread) |
| 3061 | { |
| 3062 | return not_stopped_callback (thread, minus_one_ptid); |
| 3063 | }; |
| 3064 | |
| 3065 | /* Find a resumed LWP, if any. */ |
| 3066 | if (find_thread (status_pending_p_any) != NULL) |
| 3067 | any_resumed = 1; |
| 3068 | else if (find_thread (not_stopped) != NULL) |
| 3069 | any_resumed = 1; |
| 3070 | else |
| 3071 | any_resumed = 0; |
| 3072 | |
| 3073 | if (step_over_bkpt == null_ptid) |
| 3074 | pid = wait_for_event (ptid, &w, options); |
| 3075 | else |
| 3076 | { |
| 3077 | if (debug_threads) |
| 3078 | debug_printf ("step_over_bkpt set [%s], doing a blocking wait\n", |
| 3079 | target_pid_to_str (step_over_bkpt)); |
| 3080 | pid = wait_for_event (step_over_bkpt, &w, options & ~WNOHANG); |
| 3081 | } |
| 3082 | |
| 3083 | if (pid == 0 || (pid == -1 && !any_resumed)) |
| 3084 | { |
| 3085 | gdb_assert (target_options & TARGET_WNOHANG); |
| 3086 | |
| 3087 | if (debug_threads) |
| 3088 | { |
| 3089 | debug_printf ("wait_1 ret = null_ptid, " |
| 3090 | "TARGET_WAITKIND_IGNORE\n"); |
| 3091 | debug_exit (); |
| 3092 | } |
| 3093 | |
| 3094 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
| 3095 | return null_ptid; |
| 3096 | } |
| 3097 | else if (pid == -1) |
| 3098 | { |
| 3099 | if (debug_threads) |
| 3100 | { |
| 3101 | debug_printf ("wait_1 ret = null_ptid, " |
| 3102 | "TARGET_WAITKIND_NO_RESUMED\n"); |
| 3103 | debug_exit (); |
| 3104 | } |
| 3105 | |
| 3106 | ourstatus->kind = TARGET_WAITKIND_NO_RESUMED; |
| 3107 | return null_ptid; |
| 3108 | } |
| 3109 | |
| 3110 | event_child = get_thread_lwp (current_thread); |
| 3111 | |
| 3112 | /* wait_for_event only returns an exit status for the last |
| 3113 | child of a process. Report it. */ |
| 3114 | if (WIFEXITED (w) || WIFSIGNALED (w)) |
| 3115 | { |
| 3116 | if (WIFEXITED (w)) |
| 3117 | { |
| 3118 | ourstatus->kind = TARGET_WAITKIND_EXITED; |
| 3119 | ourstatus->value.integer = WEXITSTATUS (w); |
| 3120 | |
| 3121 | if (debug_threads) |
| 3122 | { |
| 3123 | debug_printf ("wait_1 ret = %s, exited with " |
| 3124 | "retcode %d\n", |
| 3125 | target_pid_to_str (ptid_of (current_thread)), |
| 3126 | WEXITSTATUS (w)); |
| 3127 | debug_exit (); |
| 3128 | } |
| 3129 | } |
| 3130 | else |
| 3131 | { |
| 3132 | ourstatus->kind = TARGET_WAITKIND_SIGNALLED; |
| 3133 | ourstatus->value.sig = gdb_signal_from_host (WTERMSIG (w)); |
| 3134 | |
| 3135 | if (debug_threads) |
| 3136 | { |
| 3137 | debug_printf ("wait_1 ret = %s, terminated with " |
| 3138 | "signal %d\n", |
| 3139 | target_pid_to_str (ptid_of (current_thread)), |
| 3140 | WTERMSIG (w)); |
| 3141 | debug_exit (); |
| 3142 | } |
| 3143 | } |
| 3144 | |
| 3145 | if (ourstatus->kind == TARGET_WAITKIND_EXITED) |
| 3146 | return filter_exit_event (event_child, ourstatus); |
| 3147 | |
| 3148 | return ptid_of (current_thread); |
| 3149 | } |
| 3150 | |
| 3151 | /* If step-over executes a breakpoint instruction, in the case of a |
| 3152 | hardware single step it means a gdb/gdbserver breakpoint had been |
| 3153 | planted on top of a permanent breakpoint, in the case of a software |
| 3154 | single step it may just mean that gdbserver hit the reinsert breakpoint. |
| 3155 | The PC has been adjusted by save_stop_reason to point at |
| 3156 | the breakpoint address. |
| 3157 | So in the case of the hardware single step advance the PC manually |
| 3158 | past the breakpoint and in the case of software single step advance only |
| 3159 | if it's not the single_step_breakpoint we are hitting. |
| 3160 | This avoids that a program would keep trapping a permanent breakpoint |
| 3161 | forever. */ |
| 3162 | if (step_over_bkpt != null_ptid |
| 3163 | && event_child->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
| 3164 | && (event_child->stepping |
| 3165 | || !single_step_breakpoint_inserted_here (event_child->stop_pc))) |
| 3166 | { |
| 3167 | int increment_pc = 0; |
| 3168 | int breakpoint_kind = 0; |
| 3169 | CORE_ADDR stop_pc = event_child->stop_pc; |
| 3170 | |
| 3171 | breakpoint_kind = breakpoint_kind_from_current_state (&stop_pc); |
| 3172 | sw_breakpoint_from_kind (breakpoint_kind, &increment_pc); |
| 3173 | |
| 3174 | if (debug_threads) |
| 3175 | { |
| 3176 | debug_printf ("step-over for %s executed software breakpoint\n", |
| 3177 | target_pid_to_str (ptid_of (current_thread))); |
| 3178 | } |
| 3179 | |
| 3180 | if (increment_pc != 0) |
| 3181 | { |
| 3182 | struct regcache *regcache |
| 3183 | = get_thread_regcache (current_thread, 1); |
| 3184 | |
| 3185 | event_child->stop_pc += increment_pc; |
| 3186 | low_set_pc (regcache, event_child->stop_pc); |
| 3187 | |
| 3188 | if (!low_breakpoint_at (event_child->stop_pc)) |
| 3189 | event_child->stop_reason = TARGET_STOPPED_BY_NO_REASON; |
| 3190 | } |
| 3191 | } |
| 3192 | |
| 3193 | /* If this event was not handled before, and is not a SIGTRAP, we |
| 3194 | report it. SIGILL and SIGSEGV are also treated as traps in case |
| 3195 | a breakpoint is inserted at the current PC. If this target does |
| 3196 | not support internal breakpoints at all, we also report the |
| 3197 | SIGTRAP without further processing; it's of no concern to us. */ |
| 3198 | maybe_internal_trap |
| 3199 | = (low_supports_breakpoints () |
| 3200 | && (WSTOPSIG (w) == SIGTRAP |
| 3201 | || ((WSTOPSIG (w) == SIGILL |
| 3202 | || WSTOPSIG (w) == SIGSEGV) |
| 3203 | && low_breakpoint_at (event_child->stop_pc)))); |
| 3204 | |
| 3205 | if (maybe_internal_trap) |
| 3206 | { |
| 3207 | /* Handle anything that requires bookkeeping before deciding to |
| 3208 | report the event or continue waiting. */ |
| 3209 | |
| 3210 | /* First check if we can explain the SIGTRAP with an internal |
| 3211 | breakpoint, or if we should possibly report the event to GDB. |
| 3212 | Do this before anything that may remove or insert a |
| 3213 | breakpoint. */ |
| 3214 | bp_explains_trap = breakpoint_inserted_here (event_child->stop_pc); |
| 3215 | |
| 3216 | /* We have a SIGTRAP, possibly a step-over dance has just |
| 3217 | finished. If so, tweak the state machine accordingly, |
| 3218 | reinsert breakpoints and delete any single-step |
| 3219 | breakpoints. */ |
| 3220 | step_over_finished = finish_step_over (event_child); |
| 3221 | |
| 3222 | /* Now invoke the callbacks of any internal breakpoints there. */ |
| 3223 | check_breakpoints (event_child->stop_pc); |
| 3224 | |
| 3225 | /* Handle tracepoint data collecting. This may overflow the |
| 3226 | trace buffer, and cause a tracing stop, removing |
| 3227 | breakpoints. */ |
| 3228 | trace_event = handle_tracepoints (event_child); |
| 3229 | |
| 3230 | if (bp_explains_trap) |
| 3231 | { |
| 3232 | if (debug_threads) |
| 3233 | debug_printf ("Hit a gdbserver breakpoint.\n"); |
| 3234 | } |
| 3235 | } |
| 3236 | else |
| 3237 | { |
| 3238 | /* We have some other signal, possibly a step-over dance was in |
| 3239 | progress, and it should be cancelled too. */ |
| 3240 | step_over_finished = finish_step_over (event_child); |
| 3241 | } |
| 3242 | |
| 3243 | /* We have all the data we need. Either report the event to GDB, or |
| 3244 | resume threads and keep waiting for more. */ |
| 3245 | |
| 3246 | /* If we're collecting a fast tracepoint, finish the collection and |
| 3247 | move out of the jump pad before delivering a signal. See |
| 3248 | linux_stabilize_threads. */ |
| 3249 | |
| 3250 | if (WIFSTOPPED (w) |
| 3251 | && WSTOPSIG (w) != SIGTRAP |
| 3252 | && supports_fast_tracepoints () |
| 3253 | && agent_loaded_p ()) |
| 3254 | { |
| 3255 | if (debug_threads) |
| 3256 | debug_printf ("Got signal %d for LWP %ld. Check if we need " |
| 3257 | "to defer or adjust it.\n", |
| 3258 | WSTOPSIG (w), lwpid_of (current_thread)); |
| 3259 | |
| 3260 | /* Allow debugging the jump pad itself. */ |
| 3261 | if (current_thread->last_resume_kind != resume_step |
| 3262 | && maybe_move_out_of_jump_pad (event_child, &w)) |
| 3263 | { |
| 3264 | enqueue_one_deferred_signal (event_child, &w); |
| 3265 | |
| 3266 | if (debug_threads) |
| 3267 | debug_printf ("Signal %d for LWP %ld deferred (in jump pad)\n", |
| 3268 | WSTOPSIG (w), lwpid_of (current_thread)); |
| 3269 | |
| 3270 | resume_one_lwp (event_child, 0, 0, NULL); |
| 3271 | |
| 3272 | if (debug_threads) |
| 3273 | debug_exit (); |
| 3274 | return ignore_event (ourstatus); |
| 3275 | } |
| 3276 | } |
| 3277 | |
| 3278 | if (event_child->collecting_fast_tracepoint |
| 3279 | != fast_tpoint_collect_result::not_collecting) |
| 3280 | { |
| 3281 | if (debug_threads) |
| 3282 | debug_printf ("LWP %ld was trying to move out of the jump pad (%d). " |
| 3283 | "Check if we're already there.\n", |
| 3284 | lwpid_of (current_thread), |
| 3285 | (int) event_child->collecting_fast_tracepoint); |
| 3286 | |
| 3287 | trace_event = 1; |
| 3288 | |
| 3289 | event_child->collecting_fast_tracepoint |
| 3290 | = linux_fast_tracepoint_collecting (event_child, NULL); |
| 3291 | |
| 3292 | if (event_child->collecting_fast_tracepoint |
| 3293 | != fast_tpoint_collect_result::before_insn) |
| 3294 | { |
| 3295 | /* No longer need this breakpoint. */ |
| 3296 | if (event_child->exit_jump_pad_bkpt != NULL) |
| 3297 | { |
| 3298 | if (debug_threads) |
| 3299 | debug_printf ("No longer need exit-jump-pad bkpt; removing it." |
| 3300 | "stopping all threads momentarily.\n"); |
| 3301 | |
| 3302 | /* Other running threads could hit this breakpoint. |
| 3303 | We don't handle moribund locations like GDB does, |
| 3304 | instead we always pause all threads when removing |
| 3305 | breakpoints, so that any step-over or |
| 3306 | decr_pc_after_break adjustment is always taken |
| 3307 | care of while the breakpoint is still |
| 3308 | inserted. */ |
| 3309 | stop_all_lwps (1, event_child); |
| 3310 | |
| 3311 | delete_breakpoint (event_child->exit_jump_pad_bkpt); |
| 3312 | event_child->exit_jump_pad_bkpt = NULL; |
| 3313 | |
| 3314 | unstop_all_lwps (1, event_child); |
| 3315 | |
| 3316 | gdb_assert (event_child->suspended >= 0); |
| 3317 | } |
| 3318 | } |
| 3319 | |
| 3320 | if (event_child->collecting_fast_tracepoint |
| 3321 | == fast_tpoint_collect_result::not_collecting) |
| 3322 | { |
| 3323 | if (debug_threads) |
| 3324 | debug_printf ("fast tracepoint finished " |
| 3325 | "collecting successfully.\n"); |
| 3326 | |
| 3327 | /* We may have a deferred signal to report. */ |
| 3328 | if (dequeue_one_deferred_signal (event_child, &w)) |
| 3329 | { |
| 3330 | if (debug_threads) |
| 3331 | debug_printf ("dequeued one signal.\n"); |
| 3332 | } |
| 3333 | else |
| 3334 | { |
| 3335 | if (debug_threads) |
| 3336 | debug_printf ("no deferred signals.\n"); |
| 3337 | |
| 3338 | if (stabilizing_threads) |
| 3339 | { |
| 3340 | ourstatus->kind = TARGET_WAITKIND_STOPPED; |
| 3341 | ourstatus->value.sig = GDB_SIGNAL_0; |
| 3342 | |
| 3343 | if (debug_threads) |
| 3344 | { |
| 3345 | debug_printf ("wait_1 ret = %s, stopped " |
| 3346 | "while stabilizing threads\n", |
| 3347 | target_pid_to_str (ptid_of (current_thread))); |
| 3348 | debug_exit (); |
| 3349 | } |
| 3350 | |
| 3351 | return ptid_of (current_thread); |
| 3352 | } |
| 3353 | } |
| 3354 | } |
| 3355 | } |
| 3356 | |
| 3357 | /* Check whether GDB would be interested in this event. */ |
| 3358 | |
| 3359 | /* Check if GDB is interested in this syscall. */ |
| 3360 | if (WIFSTOPPED (w) |
| 3361 | && WSTOPSIG (w) == SYSCALL_SIGTRAP |
| 3362 | && !gdb_catch_this_syscall_p (event_child)) |
| 3363 | { |
| 3364 | if (debug_threads) |
| 3365 | { |
| 3366 | debug_printf ("Ignored syscall for LWP %ld.\n", |
| 3367 | lwpid_of (current_thread)); |
| 3368 | } |
| 3369 | |
| 3370 | resume_one_lwp (event_child, event_child->stepping, 0, NULL); |
| 3371 | |
| 3372 | if (debug_threads) |
| 3373 | debug_exit (); |
| 3374 | return ignore_event (ourstatus); |
| 3375 | } |
| 3376 | |
| 3377 | /* If GDB is not interested in this signal, don't stop other |
| 3378 | threads, and don't report it to GDB. Just resume the inferior |
| 3379 | right away. We do this for threading-related signals as well as |
| 3380 | any that GDB specifically requested we ignore. But never ignore |
| 3381 | SIGSTOP if we sent it ourselves, and do not ignore signals when |
| 3382 | stepping - they may require special handling to skip the signal |
| 3383 | handler. Also never ignore signals that could be caused by a |
| 3384 | breakpoint. */ |
| 3385 | if (WIFSTOPPED (w) |
| 3386 | && current_thread->last_resume_kind != resume_step |
| 3387 | && ( |
| 3388 | #if defined (USE_THREAD_DB) && !defined (__ANDROID__) |
| 3389 | (current_process ()->priv->thread_db != NULL |
| 3390 | && (WSTOPSIG (w) == __SIGRTMIN |
| 3391 | || WSTOPSIG (w) == __SIGRTMIN + 1)) |
| 3392 | || |
| 3393 | #endif |
| 3394 | (cs.pass_signals[gdb_signal_from_host (WSTOPSIG (w))] |
| 3395 | && !(WSTOPSIG (w) == SIGSTOP |
| 3396 | && current_thread->last_resume_kind == resume_stop) |
| 3397 | && !linux_wstatus_maybe_breakpoint (w)))) |
| 3398 | { |
| 3399 | siginfo_t info, *info_p; |
| 3400 | |
| 3401 | if (debug_threads) |
| 3402 | debug_printf ("Ignored signal %d for LWP %ld.\n", |
| 3403 | WSTOPSIG (w), lwpid_of (current_thread)); |
| 3404 | |
| 3405 | if (ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread), |
| 3406 | (PTRACE_TYPE_ARG3) 0, &info) == 0) |
| 3407 | info_p = &info; |
| 3408 | else |
| 3409 | info_p = NULL; |
| 3410 | |
| 3411 | if (step_over_finished) |
| 3412 | { |
| 3413 | /* We cancelled this thread's step-over above. We still |
| 3414 | need to unsuspend all other LWPs, and set them back |
| 3415 | running again while the signal handler runs. */ |
| 3416 | unsuspend_all_lwps (event_child); |
| 3417 | |
| 3418 | /* Enqueue the pending signal info so that proceed_all_lwps |
| 3419 | doesn't lose it. */ |
| 3420 | enqueue_pending_signal (event_child, WSTOPSIG (w), info_p); |
| 3421 | |
| 3422 | proceed_all_lwps (); |
| 3423 | } |
| 3424 | else |
| 3425 | { |
| 3426 | resume_one_lwp (event_child, event_child->stepping, |
| 3427 | WSTOPSIG (w), info_p); |
| 3428 | } |
| 3429 | |
| 3430 | if (debug_threads) |
| 3431 | debug_exit (); |
| 3432 | |
| 3433 | return ignore_event (ourstatus); |
| 3434 | } |
| 3435 | |
| 3436 | /* Note that all addresses are always "out of the step range" when |
| 3437 | there's no range to begin with. */ |
| 3438 | in_step_range = lwp_in_step_range (event_child); |
| 3439 | |
| 3440 | /* If GDB wanted this thread to single step, and the thread is out |
| 3441 | of the step range, we always want to report the SIGTRAP, and let |
| 3442 | GDB handle it. Watchpoints should always be reported. So should |
| 3443 | signals we can't explain. A SIGTRAP we can't explain could be a |
| 3444 | GDB breakpoint --- we may or not support Z0 breakpoints. If we |
| 3445 | do, we're be able to handle GDB breakpoints on top of internal |
| 3446 | breakpoints, by handling the internal breakpoint and still |
| 3447 | reporting the event to GDB. If we don't, we're out of luck, GDB |
| 3448 | won't see the breakpoint hit. If we see a single-step event but |
| 3449 | the thread should be continuing, don't pass the trap to gdb. |
| 3450 | That indicates that we had previously finished a single-step but |
| 3451 | left the single-step pending -- see |
| 3452 | complete_ongoing_step_over. */ |
| 3453 | report_to_gdb = (!maybe_internal_trap |
| 3454 | || (current_thread->last_resume_kind == resume_step |
| 3455 | && !in_step_range) |
| 3456 | || event_child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT |
| 3457 | || (!in_step_range |
| 3458 | && !bp_explains_trap |
| 3459 | && !trace_event |
| 3460 | && !step_over_finished |
| 3461 | && !(current_thread->last_resume_kind == resume_continue |
| 3462 | && event_child->stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)) |
| 3463 | || (gdb_breakpoint_here (event_child->stop_pc) |
| 3464 | && gdb_condition_true_at_breakpoint (event_child->stop_pc) |
| 3465 | && gdb_no_commands_at_breakpoint (event_child->stop_pc)) |
| 3466 | || event_child->waitstatus.kind != TARGET_WAITKIND_IGNORE); |
| 3467 | |
| 3468 | run_breakpoint_commands (event_child->stop_pc); |
| 3469 | |
| 3470 | /* We found no reason GDB would want us to stop. We either hit one |
| 3471 | of our own breakpoints, or finished an internal step GDB |
| 3472 | shouldn't know about. */ |
| 3473 | if (!report_to_gdb) |
| 3474 | { |
| 3475 | if (debug_threads) |
| 3476 | { |
| 3477 | if (bp_explains_trap) |
| 3478 | debug_printf ("Hit a gdbserver breakpoint.\n"); |
| 3479 | if (step_over_finished) |
| 3480 | debug_printf ("Step-over finished.\n"); |
| 3481 | if (trace_event) |
| 3482 | debug_printf ("Tracepoint event.\n"); |
| 3483 | if (lwp_in_step_range (event_child)) |
| 3484 | debug_printf ("Range stepping pc 0x%s [0x%s, 0x%s).\n", |
| 3485 | paddress (event_child->stop_pc), |
| 3486 | paddress (event_child->step_range_start), |
| 3487 | paddress (event_child->step_range_end)); |
| 3488 | } |
| 3489 | |
| 3490 | /* We're not reporting this breakpoint to GDB, so apply the |
| 3491 | decr_pc_after_break adjustment to the inferior's regcache |
| 3492 | ourselves. */ |
| 3493 | |
| 3494 | if (low_supports_breakpoints ()) |
| 3495 | { |
| 3496 | struct regcache *regcache |
| 3497 | = get_thread_regcache (current_thread, 1); |
| 3498 | low_set_pc (regcache, event_child->stop_pc); |
| 3499 | } |
| 3500 | |
| 3501 | if (step_over_finished) |
| 3502 | { |
| 3503 | /* If we have finished stepping over a breakpoint, we've |
| 3504 | stopped and suspended all LWPs momentarily except the |
| 3505 | stepping one. This is where we resume them all again. |
| 3506 | We're going to keep waiting, so use proceed, which |
| 3507 | handles stepping over the next breakpoint. */ |
| 3508 | unsuspend_all_lwps (event_child); |
| 3509 | } |
| 3510 | else |
| 3511 | { |
| 3512 | /* Remove the single-step breakpoints if any. Note that |
| 3513 | there isn't single-step breakpoint if we finished stepping |
| 3514 | over. */ |
| 3515 | if (supports_software_single_step () |
| 3516 | && has_single_step_breakpoints (current_thread)) |
| 3517 | { |
| 3518 | stop_all_lwps (0, event_child); |
| 3519 | delete_single_step_breakpoints (current_thread); |
| 3520 | unstop_all_lwps (0, event_child); |
| 3521 | } |
| 3522 | } |
| 3523 | |
| 3524 | if (debug_threads) |
| 3525 | debug_printf ("proceeding all threads.\n"); |
| 3526 | proceed_all_lwps (); |
| 3527 | |
| 3528 | if (debug_threads) |
| 3529 | debug_exit (); |
| 3530 | |
| 3531 | return ignore_event (ourstatus); |
| 3532 | } |
| 3533 | |
| 3534 | if (debug_threads) |
| 3535 | { |
| 3536 | if (event_child->waitstatus.kind != TARGET_WAITKIND_IGNORE) |
| 3537 | { |
| 3538 | std::string str |
| 3539 | = target_waitstatus_to_string (&event_child->waitstatus); |
| 3540 | |
| 3541 | debug_printf ("LWP %ld: extended event with waitstatus %s\n", |
| 3542 | lwpid_of (get_lwp_thread (event_child)), str.c_str ()); |
| 3543 | } |
| 3544 | if (current_thread->last_resume_kind == resume_step) |
| 3545 | { |
| 3546 | if (event_child->step_range_start == event_child->step_range_end) |
| 3547 | debug_printf ("GDB wanted to single-step, reporting event.\n"); |
| 3548 | else if (!lwp_in_step_range (event_child)) |
| 3549 | debug_printf ("Out of step range, reporting event.\n"); |
| 3550 | } |
| 3551 | if (event_child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT) |
| 3552 | debug_printf ("Stopped by watchpoint.\n"); |
| 3553 | else if (gdb_breakpoint_here (event_child->stop_pc)) |
| 3554 | debug_printf ("Stopped by GDB breakpoint.\n"); |
| 3555 | if (debug_threads) |
| 3556 | debug_printf ("Hit a non-gdbserver trap event.\n"); |
| 3557 | } |
| 3558 | |
| 3559 | /* Alright, we're going to report a stop. */ |
| 3560 | |
| 3561 | /* Remove single-step breakpoints. */ |
| 3562 | if (supports_software_single_step ()) |
| 3563 | { |
| 3564 | /* Remove single-step breakpoints or not. It it is true, stop all |
| 3565 | lwps, so that other threads won't hit the breakpoint in the |
| 3566 | staled memory. */ |
| 3567 | int remove_single_step_breakpoints_p = 0; |
| 3568 | |
| 3569 | if (non_stop) |
| 3570 | { |
| 3571 | remove_single_step_breakpoints_p |
| 3572 | = has_single_step_breakpoints (current_thread); |
| 3573 | } |
| 3574 | else |
| 3575 | { |
| 3576 | /* In all-stop, a stop reply cancels all previous resume |
| 3577 | requests. Delete all single-step breakpoints. */ |
| 3578 | |
| 3579 | find_thread ([&] (thread_info *thread) { |
| 3580 | if (has_single_step_breakpoints (thread)) |
| 3581 | { |
| 3582 | remove_single_step_breakpoints_p = 1; |
| 3583 | return true; |
| 3584 | } |
| 3585 | |
| 3586 | return false; |
| 3587 | }); |
| 3588 | } |
| 3589 | |
| 3590 | if (remove_single_step_breakpoints_p) |
| 3591 | { |
| 3592 | /* If we remove single-step breakpoints from memory, stop all lwps, |
| 3593 | so that other threads won't hit the breakpoint in the staled |
| 3594 | memory. */ |
| 3595 | stop_all_lwps (0, event_child); |
| 3596 | |
| 3597 | if (non_stop) |
| 3598 | { |
| 3599 | gdb_assert (has_single_step_breakpoints (current_thread)); |
| 3600 | delete_single_step_breakpoints (current_thread); |
| 3601 | } |
| 3602 | else |
| 3603 | { |
| 3604 | for_each_thread ([] (thread_info *thread){ |
| 3605 | if (has_single_step_breakpoints (thread)) |
| 3606 | delete_single_step_breakpoints (thread); |
| 3607 | }); |
| 3608 | } |
| 3609 | |
| 3610 | unstop_all_lwps (0, event_child); |
| 3611 | } |
| 3612 | } |
| 3613 | |
| 3614 | if (!stabilizing_threads) |
| 3615 | { |
| 3616 | /* In all-stop, stop all threads. */ |
| 3617 | if (!non_stop) |
| 3618 | stop_all_lwps (0, NULL); |
| 3619 | |
| 3620 | if (step_over_finished) |
| 3621 | { |
| 3622 | if (!non_stop) |
| 3623 | { |
| 3624 | /* If we were doing a step-over, all other threads but |
| 3625 | the stepping one had been paused in start_step_over, |
| 3626 | with their suspend counts incremented. We don't want |
| 3627 | to do a full unstop/unpause, because we're in |
| 3628 | all-stop mode (so we want threads stopped), but we |
| 3629 | still need to unsuspend the other threads, to |
| 3630 | decrement their `suspended' count back. */ |
| 3631 | unsuspend_all_lwps (event_child); |
| 3632 | } |
| 3633 | else |
| 3634 | { |
| 3635 | /* If we just finished a step-over, then all threads had |
| 3636 | been momentarily paused. In all-stop, that's fine, |
| 3637 | we want threads stopped by now anyway. In non-stop, |
| 3638 | we need to re-resume threads that GDB wanted to be |
| 3639 | running. */ |
| 3640 | unstop_all_lwps (1, event_child); |
| 3641 | } |
| 3642 | } |
| 3643 | |
| 3644 | /* If we're not waiting for a specific LWP, choose an event LWP |
| 3645 | from among those that have had events. Giving equal priority |
| 3646 | to all LWPs that have had events helps prevent |
| 3647 | starvation. */ |
| 3648 | if (ptid == minus_one_ptid) |
| 3649 | { |
| 3650 | event_child->status_pending_p = 1; |
| 3651 | event_child->status_pending = w; |
| 3652 | |
| 3653 | select_event_lwp (&event_child); |
| 3654 | |
| 3655 | /* current_thread and event_child must stay in sync. */ |
| 3656 | current_thread = get_lwp_thread (event_child); |
| 3657 | |
| 3658 | event_child->status_pending_p = 0; |
| 3659 | w = event_child->status_pending; |
| 3660 | } |
| 3661 | |
| 3662 | |
| 3663 | /* Stabilize threads (move out of jump pads). */ |
| 3664 | if (!non_stop) |
| 3665 | target_stabilize_threads (); |
| 3666 | } |
| 3667 | else |
| 3668 | { |
| 3669 | /* If we just finished a step-over, then all threads had been |
| 3670 | momentarily paused. In all-stop, that's fine, we want |
| 3671 | threads stopped by now anyway. In non-stop, we need to |
| 3672 | re-resume threads that GDB wanted to be running. */ |
| 3673 | if (step_over_finished) |
| 3674 | unstop_all_lwps (1, event_child); |
| 3675 | } |
| 3676 | |
| 3677 | if (event_child->waitstatus.kind != TARGET_WAITKIND_IGNORE) |
| 3678 | { |
| 3679 | /* If the reported event is an exit, fork, vfork or exec, let |
| 3680 | GDB know. */ |
| 3681 | |
| 3682 | /* Break the unreported fork relationship chain. */ |
| 3683 | if (event_child->waitstatus.kind == TARGET_WAITKIND_FORKED |
| 3684 | || event_child->waitstatus.kind == TARGET_WAITKIND_VFORKED) |
| 3685 | { |
| 3686 | event_child->fork_relative->fork_relative = NULL; |
| 3687 | event_child->fork_relative = NULL; |
| 3688 | } |
| 3689 | |
| 3690 | *ourstatus = event_child->waitstatus; |
| 3691 | /* Clear the event lwp's waitstatus since we handled it already. */ |
| 3692 | event_child->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
| 3693 | } |
| 3694 | else |
| 3695 | ourstatus->kind = TARGET_WAITKIND_STOPPED; |
| 3696 | |
| 3697 | /* Now that we've selected our final event LWP, un-adjust its PC if |
| 3698 | it was a software breakpoint, and the client doesn't know we can |
| 3699 | adjust the breakpoint ourselves. */ |
| 3700 | if (event_child->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
| 3701 | && !cs.swbreak_feature) |
| 3702 | { |
| 3703 | int decr_pc = low_decr_pc_after_break (); |
| 3704 | |
| 3705 | if (decr_pc != 0) |
| 3706 | { |
| 3707 | struct regcache *regcache |
| 3708 | = get_thread_regcache (current_thread, 1); |
| 3709 | low_set_pc (regcache, event_child->stop_pc + decr_pc); |
| 3710 | } |
| 3711 | } |
| 3712 | |
| 3713 | if (WSTOPSIG (w) == SYSCALL_SIGTRAP) |
| 3714 | { |
| 3715 | get_syscall_trapinfo (event_child, |
| 3716 | &ourstatus->value.syscall_number); |
| 3717 | ourstatus->kind = event_child->syscall_state; |
| 3718 | } |
| 3719 | else if (current_thread->last_resume_kind == resume_stop |
| 3720 | && WSTOPSIG (w) == SIGSTOP) |
| 3721 | { |
| 3722 | /* A thread that has been requested to stop by GDB with vCont;t, |
| 3723 | and it stopped cleanly, so report as SIG0. The use of |
| 3724 | SIGSTOP is an implementation detail. */ |
| 3725 | ourstatus->value.sig = GDB_SIGNAL_0; |
| 3726 | } |
| 3727 | else if (current_thread->last_resume_kind == resume_stop |
| 3728 | && WSTOPSIG (w) != SIGSTOP) |
| 3729 | { |
| 3730 | /* A thread that has been requested to stop by GDB with vCont;t, |
| 3731 | but, it stopped for other reasons. */ |
| 3732 | ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w)); |
| 3733 | } |
| 3734 | else if (ourstatus->kind == TARGET_WAITKIND_STOPPED) |
| 3735 | { |
| 3736 | ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w)); |
| 3737 | } |
| 3738 | |
| 3739 | gdb_assert (step_over_bkpt == null_ptid); |
| 3740 | |
| 3741 | if (debug_threads) |
| 3742 | { |
| 3743 | debug_printf ("wait_1 ret = %s, %d, %d\n", |
| 3744 | target_pid_to_str (ptid_of (current_thread)), |
| 3745 | ourstatus->kind, ourstatus->value.sig); |
| 3746 | debug_exit (); |
| 3747 | } |
| 3748 | |
| 3749 | if (ourstatus->kind == TARGET_WAITKIND_EXITED) |
| 3750 | return filter_exit_event (event_child, ourstatus); |
| 3751 | |
| 3752 | return ptid_of (current_thread); |
| 3753 | } |
| 3754 | |
| 3755 | /* Get rid of any pending event in the pipe. */ |
| 3756 | static void |
| 3757 | async_file_flush (void) |
| 3758 | { |
| 3759 | int ret; |
| 3760 | char buf; |
| 3761 | |
| 3762 | do |
| 3763 | ret = read (linux_event_pipe[0], &buf, 1); |
| 3764 | while (ret >= 0 || (ret == -1 && errno == EINTR)); |
| 3765 | } |
| 3766 | |
| 3767 | /* Put something in the pipe, so the event loop wakes up. */ |
| 3768 | static void |
| 3769 | async_file_mark (void) |
| 3770 | { |
| 3771 | int ret; |
| 3772 | |
| 3773 | async_file_flush (); |
| 3774 | |
| 3775 | do |
| 3776 | ret = write (linux_event_pipe[1], "+", 1); |
| 3777 | while (ret == 0 || (ret == -1 && errno == EINTR)); |
| 3778 | |
| 3779 | /* Ignore EAGAIN. If the pipe is full, the event loop will already |
| 3780 | be awakened anyway. */ |
| 3781 | } |
| 3782 | |
| 3783 | ptid_t |
| 3784 | linux_process_target::wait (ptid_t ptid, |
| 3785 | target_waitstatus *ourstatus, |
| 3786 | int target_options) |
| 3787 | { |
| 3788 | ptid_t event_ptid; |
| 3789 | |
| 3790 | /* Flush the async file first. */ |
| 3791 | if (target_is_async_p ()) |
| 3792 | async_file_flush (); |
| 3793 | |
| 3794 | do |
| 3795 | { |
| 3796 | event_ptid = wait_1 (ptid, ourstatus, target_options); |
| 3797 | } |
| 3798 | while ((target_options & TARGET_WNOHANG) == 0 |
| 3799 | && event_ptid == null_ptid |
| 3800 | && ourstatus->kind == TARGET_WAITKIND_IGNORE); |
| 3801 | |
| 3802 | /* If at least one stop was reported, there may be more. A single |
| 3803 | SIGCHLD can signal more than one child stop. */ |
| 3804 | if (target_is_async_p () |
| 3805 | && (target_options & TARGET_WNOHANG) != 0 |
| 3806 | && event_ptid != null_ptid) |
| 3807 | async_file_mark (); |
| 3808 | |
| 3809 | return event_ptid; |
| 3810 | } |
| 3811 | |
| 3812 | /* Send a signal to an LWP. */ |
| 3813 | |
| 3814 | static int |
| 3815 | kill_lwp (unsigned long lwpid, int signo) |
| 3816 | { |
| 3817 | int ret; |
| 3818 | |
| 3819 | errno = 0; |
| 3820 | ret = syscall (__NR_tkill, lwpid, signo); |
| 3821 | if (errno == ENOSYS) |
| 3822 | { |
| 3823 | /* If tkill fails, then we are not using nptl threads, a |
| 3824 | configuration we no longer support. */ |
| 3825 | perror_with_name (("tkill")); |
| 3826 | } |
| 3827 | return ret; |
| 3828 | } |
| 3829 | |
| 3830 | void |
| 3831 | linux_stop_lwp (struct lwp_info *lwp) |
| 3832 | { |
| 3833 | send_sigstop (lwp); |
| 3834 | } |
| 3835 | |
| 3836 | static void |
| 3837 | send_sigstop (struct lwp_info *lwp) |
| 3838 | { |
| 3839 | int pid; |
| 3840 | |
| 3841 | pid = lwpid_of (get_lwp_thread (lwp)); |
| 3842 | |
| 3843 | /* If we already have a pending stop signal for this process, don't |
| 3844 | send another. */ |
| 3845 | if (lwp->stop_expected) |
| 3846 | { |
| 3847 | if (debug_threads) |
| 3848 | debug_printf ("Have pending sigstop for lwp %d\n", pid); |
| 3849 | |
| 3850 | return; |
| 3851 | } |
| 3852 | |
| 3853 | if (debug_threads) |
| 3854 | debug_printf ("Sending sigstop to lwp %d\n", pid); |
| 3855 | |
| 3856 | lwp->stop_expected = 1; |
| 3857 | kill_lwp (pid, SIGSTOP); |
| 3858 | } |
| 3859 | |
| 3860 | static void |
| 3861 | send_sigstop (thread_info *thread, lwp_info *except) |
| 3862 | { |
| 3863 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 3864 | |
| 3865 | /* Ignore EXCEPT. */ |
| 3866 | if (lwp == except) |
| 3867 | return; |
| 3868 | |
| 3869 | if (lwp->stopped) |
| 3870 | return; |
| 3871 | |
| 3872 | send_sigstop (lwp); |
| 3873 | } |
| 3874 | |
| 3875 | /* Increment the suspend count of an LWP, and stop it, if not stopped |
| 3876 | yet. */ |
| 3877 | static void |
| 3878 | suspend_and_send_sigstop (thread_info *thread, lwp_info *except) |
| 3879 | { |
| 3880 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 3881 | |
| 3882 | /* Ignore EXCEPT. */ |
| 3883 | if (lwp == except) |
| 3884 | return; |
| 3885 | |
| 3886 | lwp_suspended_inc (lwp); |
| 3887 | |
| 3888 | send_sigstop (thread, except); |
| 3889 | } |
| 3890 | |
| 3891 | static void |
| 3892 | mark_lwp_dead (struct lwp_info *lwp, int wstat) |
| 3893 | { |
| 3894 | /* Store the exit status for later. */ |
| 3895 | lwp->status_pending_p = 1; |
| 3896 | lwp->status_pending = wstat; |
| 3897 | |
| 3898 | /* Store in waitstatus as well, as there's nothing else to process |
| 3899 | for this event. */ |
| 3900 | if (WIFEXITED (wstat)) |
| 3901 | { |
| 3902 | lwp->waitstatus.kind = TARGET_WAITKIND_EXITED; |
| 3903 | lwp->waitstatus.value.integer = WEXITSTATUS (wstat); |
| 3904 | } |
| 3905 | else if (WIFSIGNALED (wstat)) |
| 3906 | { |
| 3907 | lwp->waitstatus.kind = TARGET_WAITKIND_SIGNALLED; |
| 3908 | lwp->waitstatus.value.sig = gdb_signal_from_host (WTERMSIG (wstat)); |
| 3909 | } |
| 3910 | |
| 3911 | /* Prevent trying to stop it. */ |
| 3912 | lwp->stopped = 1; |
| 3913 | |
| 3914 | /* No further stops are expected from a dead lwp. */ |
| 3915 | lwp->stop_expected = 0; |
| 3916 | } |
| 3917 | |
| 3918 | /* Return true if LWP has exited already, and has a pending exit event |
| 3919 | to report to GDB. */ |
| 3920 | |
| 3921 | static int |
| 3922 | lwp_is_marked_dead (struct lwp_info *lwp) |
| 3923 | { |
| 3924 | return (lwp->status_pending_p |
| 3925 | && (WIFEXITED (lwp->status_pending) |
| 3926 | || WIFSIGNALED (lwp->status_pending))); |
| 3927 | } |
| 3928 | |
| 3929 | void |
| 3930 | linux_process_target::wait_for_sigstop () |
| 3931 | { |
| 3932 | struct thread_info *saved_thread; |
| 3933 | ptid_t saved_tid; |
| 3934 | int wstat; |
| 3935 | int ret; |
| 3936 | |
| 3937 | saved_thread = current_thread; |
| 3938 | if (saved_thread != NULL) |
| 3939 | saved_tid = saved_thread->id; |
| 3940 | else |
| 3941 | saved_tid = null_ptid; /* avoid bogus unused warning */ |
| 3942 | |
| 3943 | if (debug_threads) |
| 3944 | debug_printf ("wait_for_sigstop: pulling events\n"); |
| 3945 | |
| 3946 | /* Passing NULL_PTID as filter indicates we want all events to be |
| 3947 | left pending. Eventually this returns when there are no |
| 3948 | unwaited-for children left. */ |
| 3949 | ret = wait_for_event_filtered (minus_one_ptid, null_ptid, &wstat, __WALL); |
| 3950 | gdb_assert (ret == -1); |
| 3951 | |
| 3952 | if (saved_thread == NULL || mythread_alive (saved_tid)) |
| 3953 | current_thread = saved_thread; |
| 3954 | else |
| 3955 | { |
| 3956 | if (debug_threads) |
| 3957 | debug_printf ("Previously current thread died.\n"); |
| 3958 | |
| 3959 | /* We can't change the current inferior behind GDB's back, |
| 3960 | otherwise, a subsequent command may apply to the wrong |
| 3961 | process. */ |
| 3962 | current_thread = NULL; |
| 3963 | } |
| 3964 | } |
| 3965 | |
| 3966 | /* Returns true if THREAD is stopped in a jump pad, and we can't |
| 3967 | move it out, because we need to report the stop event to GDB. For |
| 3968 | example, if the user puts a breakpoint in the jump pad, it's |
| 3969 | because she wants to debug it. */ |
| 3970 | |
| 3971 | static bool |
| 3972 | stuck_in_jump_pad_callback (thread_info *thread) |
| 3973 | { |
| 3974 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 3975 | |
| 3976 | if (lwp->suspended != 0) |
| 3977 | { |
| 3978 | internal_error (__FILE__, __LINE__, |
| 3979 | "LWP %ld is suspended, suspended=%d\n", |
| 3980 | lwpid_of (thread), lwp->suspended); |
| 3981 | } |
| 3982 | gdb_assert (lwp->stopped); |
| 3983 | |
| 3984 | /* Allow debugging the jump pad, gdb_collect, etc.. */ |
| 3985 | return (supports_fast_tracepoints () |
| 3986 | && agent_loaded_p () |
| 3987 | && (gdb_breakpoint_here (lwp->stop_pc) |
| 3988 | || lwp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT |
| 3989 | || thread->last_resume_kind == resume_step) |
| 3990 | && (linux_fast_tracepoint_collecting (lwp, NULL) |
| 3991 | != fast_tpoint_collect_result::not_collecting)); |
| 3992 | } |
| 3993 | |
| 3994 | void |
| 3995 | linux_process_target::move_out_of_jump_pad (thread_info *thread) |
| 3996 | { |
| 3997 | struct thread_info *saved_thread; |
| 3998 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 3999 | int *wstat; |
| 4000 | |
| 4001 | if (lwp->suspended != 0) |
| 4002 | { |
| 4003 | internal_error (__FILE__, __LINE__, |
| 4004 | "LWP %ld is suspended, suspended=%d\n", |
| 4005 | lwpid_of (thread), lwp->suspended); |
| 4006 | } |
| 4007 | gdb_assert (lwp->stopped); |
| 4008 | |
| 4009 | /* For gdb_breakpoint_here. */ |
| 4010 | saved_thread = current_thread; |
| 4011 | current_thread = thread; |
| 4012 | |
| 4013 | wstat = lwp->status_pending_p ? &lwp->status_pending : NULL; |
| 4014 | |
| 4015 | /* Allow debugging the jump pad, gdb_collect, etc. */ |
| 4016 | if (!gdb_breakpoint_here (lwp->stop_pc) |
| 4017 | && lwp->stop_reason != TARGET_STOPPED_BY_WATCHPOINT |
| 4018 | && thread->last_resume_kind != resume_step |
| 4019 | && maybe_move_out_of_jump_pad (lwp, wstat)) |
| 4020 | { |
| 4021 | if (debug_threads) |
| 4022 | debug_printf ("LWP %ld needs stabilizing (in jump pad)\n", |
| 4023 | lwpid_of (thread)); |
| 4024 | |
| 4025 | if (wstat) |
| 4026 | { |
| 4027 | lwp->status_pending_p = 0; |
| 4028 | enqueue_one_deferred_signal (lwp, wstat); |
| 4029 | |
| 4030 | if (debug_threads) |
| 4031 | debug_printf ("Signal %d for LWP %ld deferred " |
| 4032 | "(in jump pad)\n", |
| 4033 | WSTOPSIG (*wstat), lwpid_of (thread)); |
| 4034 | } |
| 4035 | |
| 4036 | resume_one_lwp (lwp, 0, 0, NULL); |
| 4037 | } |
| 4038 | else |
| 4039 | lwp_suspended_inc (lwp); |
| 4040 | |
| 4041 | current_thread = saved_thread; |
| 4042 | } |
| 4043 | |
| 4044 | static bool |
| 4045 | lwp_running (thread_info *thread) |
| 4046 | { |
| 4047 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 4048 | |
| 4049 | if (lwp_is_marked_dead (lwp)) |
| 4050 | return false; |
| 4051 | |
| 4052 | return !lwp->stopped; |
| 4053 | } |
| 4054 | |
| 4055 | void |
| 4056 | linux_process_target::stop_all_lwps (int suspend, lwp_info *except) |
| 4057 | { |
| 4058 | /* Should not be called recursively. */ |
| 4059 | gdb_assert (stopping_threads == NOT_STOPPING_THREADS); |
| 4060 | |
| 4061 | if (debug_threads) |
| 4062 | { |
| 4063 | debug_enter (); |
| 4064 | debug_printf ("stop_all_lwps (%s, except=%s)\n", |
| 4065 | suspend ? "stop-and-suspend" : "stop", |
| 4066 | except != NULL |
| 4067 | ? target_pid_to_str (ptid_of (get_lwp_thread (except))) |
| 4068 | : "none"); |
| 4069 | } |
| 4070 | |
| 4071 | stopping_threads = (suspend |
| 4072 | ? STOPPING_AND_SUSPENDING_THREADS |
| 4073 | : STOPPING_THREADS); |
| 4074 | |
| 4075 | if (suspend) |
| 4076 | for_each_thread ([&] (thread_info *thread) |
| 4077 | { |
| 4078 | suspend_and_send_sigstop (thread, except); |
| 4079 | }); |
| 4080 | else |
| 4081 | for_each_thread ([&] (thread_info *thread) |
| 4082 | { |
| 4083 | send_sigstop (thread, except); |
| 4084 | }); |
| 4085 | |
| 4086 | wait_for_sigstop (); |
| 4087 | stopping_threads = NOT_STOPPING_THREADS; |
| 4088 | |
| 4089 | if (debug_threads) |
| 4090 | { |
| 4091 | debug_printf ("stop_all_lwps done, setting stopping_threads " |
| 4092 | "back to !stopping\n"); |
| 4093 | debug_exit (); |
| 4094 | } |
| 4095 | } |
| 4096 | |
| 4097 | /* Enqueue one signal in the chain of signals which need to be |
| 4098 | delivered to this process on next resume. */ |
| 4099 | |
| 4100 | static void |
| 4101 | enqueue_pending_signal (struct lwp_info *lwp, int signal, siginfo_t *info) |
| 4102 | { |
| 4103 | struct pending_signals *p_sig = XNEW (struct pending_signals); |
| 4104 | |
| 4105 | p_sig->prev = lwp->pending_signals; |
| 4106 | p_sig->signal = signal; |
| 4107 | if (info == NULL) |
| 4108 | memset (&p_sig->info, 0, sizeof (siginfo_t)); |
| 4109 | else |
| 4110 | memcpy (&p_sig->info, info, sizeof (siginfo_t)); |
| 4111 | lwp->pending_signals = p_sig; |
| 4112 | } |
| 4113 | |
| 4114 | void |
| 4115 | linux_process_target::install_software_single_step_breakpoints (lwp_info *lwp) |
| 4116 | { |
| 4117 | struct thread_info *thread = get_lwp_thread (lwp); |
| 4118 | struct regcache *regcache = get_thread_regcache (thread, 1); |
| 4119 | |
| 4120 | scoped_restore save_current_thread = make_scoped_restore (¤t_thread); |
| 4121 | |
| 4122 | current_thread = thread; |
| 4123 | std::vector<CORE_ADDR> next_pcs = low_get_next_pcs (regcache); |
| 4124 | |
| 4125 | for (CORE_ADDR pc : next_pcs) |
| 4126 | set_single_step_breakpoint (pc, current_ptid); |
| 4127 | } |
| 4128 | |
| 4129 | int |
| 4130 | linux_process_target::single_step (lwp_info* lwp) |
| 4131 | { |
| 4132 | int step = 0; |
| 4133 | |
| 4134 | if (can_hardware_single_step ()) |
| 4135 | { |
| 4136 | step = 1; |
| 4137 | } |
| 4138 | else if (supports_software_single_step ()) |
| 4139 | { |
| 4140 | install_software_single_step_breakpoints (lwp); |
| 4141 | step = 0; |
| 4142 | } |
| 4143 | else |
| 4144 | { |
| 4145 | if (debug_threads) |
| 4146 | debug_printf ("stepping is not implemented on this target"); |
| 4147 | } |
| 4148 | |
| 4149 | return step; |
| 4150 | } |
| 4151 | |
| 4152 | /* The signal can be delivered to the inferior if we are not trying to |
| 4153 | finish a fast tracepoint collect. Since signal can be delivered in |
| 4154 | the step-over, the program may go to signal handler and trap again |
| 4155 | after return from the signal handler. We can live with the spurious |
| 4156 | double traps. */ |
| 4157 | |
| 4158 | static int |
| 4159 | lwp_signal_can_be_delivered (struct lwp_info *lwp) |
| 4160 | { |
| 4161 | return (lwp->collecting_fast_tracepoint |
| 4162 | == fast_tpoint_collect_result::not_collecting); |
| 4163 | } |
| 4164 | |
| 4165 | void |
| 4166 | linux_process_target::resume_one_lwp_throw (lwp_info *lwp, int step, |
| 4167 | int signal, siginfo_t *info) |
| 4168 | { |
| 4169 | struct thread_info *thread = get_lwp_thread (lwp); |
| 4170 | struct thread_info *saved_thread; |
| 4171 | int ptrace_request; |
| 4172 | struct process_info *proc = get_thread_process (thread); |
| 4173 | |
| 4174 | /* Note that target description may not be initialised |
| 4175 | (proc->tdesc == NULL) at this point because the program hasn't |
| 4176 | stopped at the first instruction yet. It means GDBserver skips |
| 4177 | the extra traps from the wrapper program (see option --wrapper). |
| 4178 | Code in this function that requires register access should be |
| 4179 | guarded by proc->tdesc == NULL or something else. */ |
| 4180 | |
| 4181 | if (lwp->stopped == 0) |
| 4182 | return; |
| 4183 | |
| 4184 | gdb_assert (lwp->waitstatus.kind == TARGET_WAITKIND_IGNORE); |
| 4185 | |
| 4186 | fast_tpoint_collect_result fast_tp_collecting |
| 4187 | = lwp->collecting_fast_tracepoint; |
| 4188 | |
| 4189 | gdb_assert (!stabilizing_threads |
| 4190 | || (fast_tp_collecting |
| 4191 | != fast_tpoint_collect_result::not_collecting)); |
| 4192 | |
| 4193 | /* Cancel actions that rely on GDB not changing the PC (e.g., the |
| 4194 | user used the "jump" command, or "set $pc = foo"). */ |
| 4195 | if (thread->while_stepping != NULL && lwp->stop_pc != get_pc (lwp)) |
| 4196 | { |
| 4197 | /* Collecting 'while-stepping' actions doesn't make sense |
| 4198 | anymore. */ |
| 4199 | release_while_stepping_state_list (thread); |
| 4200 | } |
| 4201 | |
| 4202 | /* If we have pending signals or status, and a new signal, enqueue the |
| 4203 | signal. Also enqueue the signal if it can't be delivered to the |
| 4204 | inferior right now. */ |
| 4205 | if (signal != 0 |
| 4206 | && (lwp->status_pending_p |
| 4207 | || lwp->pending_signals != NULL |
| 4208 | || !lwp_signal_can_be_delivered (lwp))) |
| 4209 | { |
| 4210 | enqueue_pending_signal (lwp, signal, info); |
| 4211 | |
| 4212 | /* Postpone any pending signal. It was enqueued above. */ |
| 4213 | signal = 0; |
| 4214 | } |
| 4215 | |
| 4216 | if (lwp->status_pending_p) |
| 4217 | { |
| 4218 | if (debug_threads) |
| 4219 | debug_printf ("Not resuming lwp %ld (%s, stop %s);" |
| 4220 | " has pending status\n", |
| 4221 | lwpid_of (thread), step ? "step" : "continue", |
| 4222 | lwp->stop_expected ? "expected" : "not expected"); |
| 4223 | return; |
| 4224 | } |
| 4225 | |
| 4226 | saved_thread = current_thread; |
| 4227 | current_thread = thread; |
| 4228 | |
| 4229 | /* This bit needs some thinking about. If we get a signal that |
| 4230 | we must report while a single-step reinsert is still pending, |
| 4231 | we often end up resuming the thread. It might be better to |
| 4232 | (ew) allow a stack of pending events; then we could be sure that |
| 4233 | the reinsert happened right away and not lose any signals. |
| 4234 | |
| 4235 | Making this stack would also shrink the window in which breakpoints are |
| 4236 | uninserted (see comment in linux_wait_for_lwp) but not enough for |
| 4237 | complete correctness, so it won't solve that problem. It may be |
| 4238 | worthwhile just to solve this one, however. */ |
| 4239 | if (lwp->bp_reinsert != 0) |
| 4240 | { |
| 4241 | if (debug_threads) |
| 4242 | debug_printf (" pending reinsert at 0x%s\n", |
| 4243 | paddress (lwp->bp_reinsert)); |
| 4244 | |
| 4245 | if (can_hardware_single_step ()) |
| 4246 | { |
| 4247 | if (fast_tp_collecting == fast_tpoint_collect_result::not_collecting) |
| 4248 | { |
| 4249 | if (step == 0) |
| 4250 | warning ("BAD - reinserting but not stepping."); |
| 4251 | if (lwp->suspended) |
| 4252 | warning ("BAD - reinserting and suspended(%d).", |
| 4253 | lwp->suspended); |
| 4254 | } |
| 4255 | } |
| 4256 | |
| 4257 | step = maybe_hw_step (thread); |
| 4258 | } |
| 4259 | |
| 4260 | if (fast_tp_collecting == fast_tpoint_collect_result::before_insn) |
| 4261 | { |
| 4262 | if (debug_threads) |
| 4263 | debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad" |
| 4264 | " (exit-jump-pad-bkpt)\n", |
| 4265 | lwpid_of (thread)); |
| 4266 | } |
| 4267 | else if (fast_tp_collecting == fast_tpoint_collect_result::at_insn) |
| 4268 | { |
| 4269 | if (debug_threads) |
| 4270 | debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad" |
| 4271 | " single-stepping\n", |
| 4272 | lwpid_of (thread)); |
| 4273 | |
| 4274 | if (can_hardware_single_step ()) |
| 4275 | step = 1; |
| 4276 | else |
| 4277 | { |
| 4278 | internal_error (__FILE__, __LINE__, |
| 4279 | "moving out of jump pad single-stepping" |
| 4280 | " not implemented on this target"); |
| 4281 | } |
| 4282 | } |
| 4283 | |
| 4284 | /* If we have while-stepping actions in this thread set it stepping. |
| 4285 | If we have a signal to deliver, it may or may not be set to |
| 4286 | SIG_IGN, we don't know. Assume so, and allow collecting |
| 4287 | while-stepping into a signal handler. A possible smart thing to |
| 4288 | do would be to set an internal breakpoint at the signal return |
| 4289 | address, continue, and carry on catching this while-stepping |
| 4290 | action only when that breakpoint is hit. A future |
| 4291 | enhancement. */ |
| 4292 | if (thread->while_stepping != NULL) |
| 4293 | { |
| 4294 | if (debug_threads) |
| 4295 | debug_printf ("lwp %ld has a while-stepping action -> forcing step.\n", |
| 4296 | lwpid_of (thread)); |
| 4297 | |
| 4298 | step = single_step (lwp); |
| 4299 | } |
| 4300 | |
| 4301 | if (proc->tdesc != NULL && low_supports_breakpoints ()) |
| 4302 | { |
| 4303 | struct regcache *regcache = get_thread_regcache (current_thread, 1); |
| 4304 | |
| 4305 | lwp->stop_pc = low_get_pc (regcache); |
| 4306 | |
| 4307 | if (debug_threads) |
| 4308 | { |
| 4309 | debug_printf (" %s from pc 0x%lx\n", step ? "step" : "continue", |
| 4310 | (long) lwp->stop_pc); |
| 4311 | } |
| 4312 | } |
| 4313 | |
| 4314 | /* If we have pending signals, consume one if it can be delivered to |
| 4315 | the inferior. */ |
| 4316 | if (lwp->pending_signals != NULL && lwp_signal_can_be_delivered (lwp)) |
| 4317 | { |
| 4318 | struct pending_signals **p_sig; |
| 4319 | |
| 4320 | p_sig = &lwp->pending_signals; |
| 4321 | while ((*p_sig)->prev != NULL) |
| 4322 | p_sig = &(*p_sig)->prev; |
| 4323 | |
| 4324 | signal = (*p_sig)->signal; |
| 4325 | if ((*p_sig)->info.si_signo != 0) |
| 4326 | ptrace (PTRACE_SETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0, |
| 4327 | &(*p_sig)->info); |
| 4328 | |
| 4329 | free (*p_sig); |
| 4330 | *p_sig = NULL; |
| 4331 | } |
| 4332 | |
| 4333 | if (debug_threads) |
| 4334 | debug_printf ("Resuming lwp %ld (%s, signal %d, stop %s)\n", |
| 4335 | lwpid_of (thread), step ? "step" : "continue", signal, |
| 4336 | lwp->stop_expected ? "expected" : "not expected"); |
| 4337 | |
| 4338 | if (the_low_target.prepare_to_resume != NULL) |
| 4339 | the_low_target.prepare_to_resume (lwp); |
| 4340 | |
| 4341 | regcache_invalidate_thread (thread); |
| 4342 | errno = 0; |
| 4343 | lwp->stepping = step; |
| 4344 | if (step) |
| 4345 | ptrace_request = PTRACE_SINGLESTEP; |
| 4346 | else if (gdb_catching_syscalls_p (lwp)) |
| 4347 | ptrace_request = PTRACE_SYSCALL; |
| 4348 | else |
| 4349 | ptrace_request = PTRACE_CONT; |
| 4350 | ptrace (ptrace_request, |
| 4351 | lwpid_of (thread), |
| 4352 | (PTRACE_TYPE_ARG3) 0, |
| 4353 | /* Coerce to a uintptr_t first to avoid potential gcc warning |
| 4354 | of coercing an 8 byte integer to a 4 byte pointer. */ |
| 4355 | (PTRACE_TYPE_ARG4) (uintptr_t) signal); |
| 4356 | |
| 4357 | current_thread = saved_thread; |
| 4358 | if (errno) |
| 4359 | perror_with_name ("resuming thread"); |
| 4360 | |
| 4361 | /* Successfully resumed. Clear state that no longer makes sense, |
| 4362 | and mark the LWP as running. Must not do this before resuming |
| 4363 | otherwise if that fails other code will be confused. E.g., we'd |
| 4364 | later try to stop the LWP and hang forever waiting for a stop |
| 4365 | status. Note that we must not throw after this is cleared, |
| 4366 | otherwise handle_zombie_lwp_error would get confused. */ |
| 4367 | lwp->stopped = 0; |
| 4368 | lwp->stop_reason = TARGET_STOPPED_BY_NO_REASON; |
| 4369 | } |
| 4370 | |
| 4371 | /* Called when we try to resume a stopped LWP and that errors out. If |
| 4372 | the LWP is no longer in ptrace-stopped state (meaning it's zombie, |
| 4373 | or about to become), discard the error, clear any pending status |
| 4374 | the LWP may have, and return true (we'll collect the exit status |
| 4375 | soon enough). Otherwise, return false. */ |
| 4376 | |
| 4377 | static int |
| 4378 | check_ptrace_stopped_lwp_gone (struct lwp_info *lp) |
| 4379 | { |
| 4380 | struct thread_info *thread = get_lwp_thread (lp); |
| 4381 | |
| 4382 | /* If we get an error after resuming the LWP successfully, we'd |
| 4383 | confuse !T state for the LWP being gone. */ |
| 4384 | gdb_assert (lp->stopped); |
| 4385 | |
| 4386 | /* We can't just check whether the LWP is in 'Z (Zombie)' state, |
| 4387 | because even if ptrace failed with ESRCH, the tracee may be "not |
| 4388 | yet fully dead", but already refusing ptrace requests. In that |
| 4389 | case the tracee has 'R (Running)' state for a little bit |
| 4390 | (observed in Linux 3.18). See also the note on ESRCH in the |
| 4391 | ptrace(2) man page. Instead, check whether the LWP has any state |
| 4392 | other than ptrace-stopped. */ |
| 4393 | |
| 4394 | /* Don't assume anything if /proc/PID/status can't be read. */ |
| 4395 | if (linux_proc_pid_is_trace_stopped_nowarn (lwpid_of (thread)) == 0) |
| 4396 | { |
| 4397 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; |
| 4398 | lp->status_pending_p = 0; |
| 4399 | return 1; |
| 4400 | } |
| 4401 | return 0; |
| 4402 | } |
| 4403 | |
| 4404 | void |
| 4405 | linux_process_target::resume_one_lwp (lwp_info *lwp, int step, int signal, |
| 4406 | siginfo_t *info) |
| 4407 | { |
| 4408 | try |
| 4409 | { |
| 4410 | resume_one_lwp_throw (lwp, step, signal, info); |
| 4411 | } |
| 4412 | catch (const gdb_exception_error &ex) |
| 4413 | { |
| 4414 | if (!check_ptrace_stopped_lwp_gone (lwp)) |
| 4415 | throw; |
| 4416 | } |
| 4417 | } |
| 4418 | |
| 4419 | /* This function is called once per thread via for_each_thread. |
| 4420 | We look up which resume request applies to THREAD and mark it with a |
| 4421 | pointer to the appropriate resume request. |
| 4422 | |
| 4423 | This algorithm is O(threads * resume elements), but resume elements |
| 4424 | is small (and will remain small at least until GDB supports thread |
| 4425 | suspension). */ |
| 4426 | |
| 4427 | static void |
| 4428 | linux_set_resume_request (thread_info *thread, thread_resume *resume, size_t n) |
| 4429 | { |
| 4430 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 4431 | |
| 4432 | for (int ndx = 0; ndx < n; ndx++) |
| 4433 | { |
| 4434 | ptid_t ptid = resume[ndx].thread; |
| 4435 | if (ptid == minus_one_ptid |
| 4436 | || ptid == thread->id |
| 4437 | /* Handle both 'pPID' and 'pPID.-1' as meaning 'all threads |
| 4438 | of PID'. */ |
| 4439 | || (ptid.pid () == pid_of (thread) |
| 4440 | && (ptid.is_pid () |
| 4441 | || ptid.lwp () == -1))) |
| 4442 | { |
| 4443 | if (resume[ndx].kind == resume_stop |
| 4444 | && thread->last_resume_kind == resume_stop) |
| 4445 | { |
| 4446 | if (debug_threads) |
| 4447 | debug_printf ("already %s LWP %ld at GDB's request\n", |
| 4448 | (thread->last_status.kind |
| 4449 | == TARGET_WAITKIND_STOPPED) |
| 4450 | ? "stopped" |
| 4451 | : "stopping", |
| 4452 | lwpid_of (thread)); |
| 4453 | |
| 4454 | continue; |
| 4455 | } |
| 4456 | |
| 4457 | /* Ignore (wildcard) resume requests for already-resumed |
| 4458 | threads. */ |
| 4459 | if (resume[ndx].kind != resume_stop |
| 4460 | && thread->last_resume_kind != resume_stop) |
| 4461 | { |
| 4462 | if (debug_threads) |
| 4463 | debug_printf ("already %s LWP %ld at GDB's request\n", |
| 4464 | (thread->last_resume_kind |
| 4465 | == resume_step) |
| 4466 | ? "stepping" |
| 4467 | : "continuing", |
| 4468 | lwpid_of (thread)); |
| 4469 | continue; |
| 4470 | } |
| 4471 | |
| 4472 | /* Don't let wildcard resumes resume fork children that GDB |
| 4473 | does not yet know are new fork children. */ |
| 4474 | if (lwp->fork_relative != NULL) |
| 4475 | { |
| 4476 | struct lwp_info *rel = lwp->fork_relative; |
| 4477 | |
| 4478 | if (rel->status_pending_p |
| 4479 | && (rel->waitstatus.kind == TARGET_WAITKIND_FORKED |
| 4480 | || rel->waitstatus.kind == TARGET_WAITKIND_VFORKED)) |
| 4481 | { |
| 4482 | if (debug_threads) |
| 4483 | debug_printf ("not resuming LWP %ld: has queued stop reply\n", |
| 4484 | lwpid_of (thread)); |
| 4485 | continue; |
| 4486 | } |
| 4487 | } |
| 4488 | |
| 4489 | /* If the thread has a pending event that has already been |
| 4490 | reported to GDBserver core, but GDB has not pulled the |
| 4491 | event out of the vStopped queue yet, likewise, ignore the |
| 4492 | (wildcard) resume request. */ |
| 4493 | if (in_queued_stop_replies (thread->id)) |
| 4494 | { |
| 4495 | if (debug_threads) |
| 4496 | debug_printf ("not resuming LWP %ld: has queued stop reply\n", |
| 4497 | lwpid_of (thread)); |
| 4498 | continue; |
| 4499 | } |
| 4500 | |
| 4501 | lwp->resume = &resume[ndx]; |
| 4502 | thread->last_resume_kind = lwp->resume->kind; |
| 4503 | |
| 4504 | lwp->step_range_start = lwp->resume->step_range_start; |
| 4505 | lwp->step_range_end = lwp->resume->step_range_end; |
| 4506 | |
| 4507 | /* If we had a deferred signal to report, dequeue one now. |
| 4508 | This can happen if LWP gets more than one signal while |
| 4509 | trying to get out of a jump pad. */ |
| 4510 | if (lwp->stopped |
| 4511 | && !lwp->status_pending_p |
| 4512 | && dequeue_one_deferred_signal (lwp, &lwp->status_pending)) |
| 4513 | { |
| 4514 | lwp->status_pending_p = 1; |
| 4515 | |
| 4516 | if (debug_threads) |
| 4517 | debug_printf ("Dequeueing deferred signal %d for LWP %ld, " |
| 4518 | "leaving status pending.\n", |
| 4519 | WSTOPSIG (lwp->status_pending), |
| 4520 | lwpid_of (thread)); |
| 4521 | } |
| 4522 | |
| 4523 | return; |
| 4524 | } |
| 4525 | } |
| 4526 | |
| 4527 | /* No resume action for this thread. */ |
| 4528 | lwp->resume = NULL; |
| 4529 | } |
| 4530 | |
| 4531 | bool |
| 4532 | linux_process_target::resume_status_pending (thread_info *thread) |
| 4533 | { |
| 4534 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 4535 | |
| 4536 | /* LWPs which will not be resumed are not interesting, because |
| 4537 | we might not wait for them next time through linux_wait. */ |
| 4538 | if (lwp->resume == NULL) |
| 4539 | return false; |
| 4540 | |
| 4541 | return thread_still_has_status_pending (thread); |
| 4542 | } |
| 4543 | |
| 4544 | bool |
| 4545 | linux_process_target::thread_needs_step_over (thread_info *thread) |
| 4546 | { |
| 4547 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 4548 | struct thread_info *saved_thread; |
| 4549 | CORE_ADDR pc; |
| 4550 | struct process_info *proc = get_thread_process (thread); |
| 4551 | |
| 4552 | /* GDBserver is skipping the extra traps from the wrapper program, |
| 4553 | don't have to do step over. */ |
| 4554 | if (proc->tdesc == NULL) |
| 4555 | return false; |
| 4556 | |
| 4557 | /* LWPs which will not be resumed are not interesting, because we |
| 4558 | might not wait for them next time through linux_wait. */ |
| 4559 | |
| 4560 | if (!lwp->stopped) |
| 4561 | { |
| 4562 | if (debug_threads) |
| 4563 | debug_printf ("Need step over [LWP %ld]? Ignoring, not stopped\n", |
| 4564 | lwpid_of (thread)); |
| 4565 | return false; |
| 4566 | } |
| 4567 | |
| 4568 | if (thread->last_resume_kind == resume_stop) |
| 4569 | { |
| 4570 | if (debug_threads) |
| 4571 | debug_printf ("Need step over [LWP %ld]? Ignoring, should remain" |
| 4572 | " stopped\n", |
| 4573 | lwpid_of (thread)); |
| 4574 | return false; |
| 4575 | } |
| 4576 | |
| 4577 | gdb_assert (lwp->suspended >= 0); |
| 4578 | |
| 4579 | if (lwp->suspended) |
| 4580 | { |
| 4581 | if (debug_threads) |
| 4582 | debug_printf ("Need step over [LWP %ld]? Ignoring, suspended\n", |
| 4583 | lwpid_of (thread)); |
| 4584 | return false; |
| 4585 | } |
| 4586 | |
| 4587 | if (lwp->status_pending_p) |
| 4588 | { |
| 4589 | if (debug_threads) |
| 4590 | debug_printf ("Need step over [LWP %ld]? Ignoring, has pending" |
| 4591 | " status.\n", |
| 4592 | lwpid_of (thread)); |
| 4593 | return false; |
| 4594 | } |
| 4595 | |
| 4596 | /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already, |
| 4597 | or we have. */ |
| 4598 | pc = get_pc (lwp); |
| 4599 | |
| 4600 | /* If the PC has changed since we stopped, then don't do anything, |
| 4601 | and let the breakpoint/tracepoint be hit. This happens if, for |
| 4602 | instance, GDB handled the decr_pc_after_break subtraction itself, |
| 4603 | GDB is OOL stepping this thread, or the user has issued a "jump" |
| 4604 | command, or poked thread's registers herself. */ |
| 4605 | if (pc != lwp->stop_pc) |
| 4606 | { |
| 4607 | if (debug_threads) |
| 4608 | debug_printf ("Need step over [LWP %ld]? Cancelling, PC was changed. " |
| 4609 | "Old stop_pc was 0x%s, PC is now 0x%s\n", |
| 4610 | lwpid_of (thread), |
| 4611 | paddress (lwp->stop_pc), paddress (pc)); |
| 4612 | return false; |
| 4613 | } |
| 4614 | |
| 4615 | /* On software single step target, resume the inferior with signal |
| 4616 | rather than stepping over. */ |
| 4617 | if (supports_software_single_step () |
| 4618 | && lwp->pending_signals != NULL |
| 4619 | && lwp_signal_can_be_delivered (lwp)) |
| 4620 | { |
| 4621 | if (debug_threads) |
| 4622 | debug_printf ("Need step over [LWP %ld]? Ignoring, has pending" |
| 4623 | " signals.\n", |
| 4624 | lwpid_of (thread)); |
| 4625 | |
| 4626 | return false; |
| 4627 | } |
| 4628 | |
| 4629 | saved_thread = current_thread; |
| 4630 | current_thread = thread; |
| 4631 | |
| 4632 | /* We can only step over breakpoints we know about. */ |
| 4633 | if (breakpoint_here (pc) || fast_tracepoint_jump_here (pc)) |
| 4634 | { |
| 4635 | /* Don't step over a breakpoint that GDB expects to hit |
| 4636 | though. If the condition is being evaluated on the target's side |
| 4637 | and it evaluate to false, step over this breakpoint as well. */ |
| 4638 | if (gdb_breakpoint_here (pc) |
| 4639 | && gdb_condition_true_at_breakpoint (pc) |
| 4640 | && gdb_no_commands_at_breakpoint (pc)) |
| 4641 | { |
| 4642 | if (debug_threads) |
| 4643 | debug_printf ("Need step over [LWP %ld]? yes, but found" |
| 4644 | " GDB breakpoint at 0x%s; skipping step over\n", |
| 4645 | lwpid_of (thread), paddress (pc)); |
| 4646 | |
| 4647 | current_thread = saved_thread; |
| 4648 | return false; |
| 4649 | } |
| 4650 | else |
| 4651 | { |
| 4652 | if (debug_threads) |
| 4653 | debug_printf ("Need step over [LWP %ld]? yes, " |
| 4654 | "found breakpoint at 0x%s\n", |
| 4655 | lwpid_of (thread), paddress (pc)); |
| 4656 | |
| 4657 | /* We've found an lwp that needs stepping over --- return 1 so |
| 4658 | that find_thread stops looking. */ |
| 4659 | current_thread = saved_thread; |
| 4660 | |
| 4661 | return true; |
| 4662 | } |
| 4663 | } |
| 4664 | |
| 4665 | current_thread = saved_thread; |
| 4666 | |
| 4667 | if (debug_threads) |
| 4668 | debug_printf ("Need step over [LWP %ld]? No, no breakpoint found" |
| 4669 | " at 0x%s\n", |
| 4670 | lwpid_of (thread), paddress (pc)); |
| 4671 | |
| 4672 | return false; |
| 4673 | } |
| 4674 | |
| 4675 | void |
| 4676 | linux_process_target::start_step_over (lwp_info *lwp) |
| 4677 | { |
| 4678 | struct thread_info *thread = get_lwp_thread (lwp); |
| 4679 | struct thread_info *saved_thread; |
| 4680 | CORE_ADDR pc; |
| 4681 | int step; |
| 4682 | |
| 4683 | if (debug_threads) |
| 4684 | debug_printf ("Starting step-over on LWP %ld. Stopping all threads\n", |
| 4685 | lwpid_of (thread)); |
| 4686 | |
| 4687 | stop_all_lwps (1, lwp); |
| 4688 | |
| 4689 | if (lwp->suspended != 0) |
| 4690 | { |
| 4691 | internal_error (__FILE__, __LINE__, |
| 4692 | "LWP %ld suspended=%d\n", lwpid_of (thread), |
| 4693 | lwp->suspended); |
| 4694 | } |
| 4695 | |
| 4696 | if (debug_threads) |
| 4697 | debug_printf ("Done stopping all threads for step-over.\n"); |
| 4698 | |
| 4699 | /* Note, we should always reach here with an already adjusted PC, |
| 4700 | either by GDB (if we're resuming due to GDB's request), or by our |
| 4701 | caller, if we just finished handling an internal breakpoint GDB |
| 4702 | shouldn't care about. */ |
| 4703 | pc = get_pc (lwp); |
| 4704 | |
| 4705 | saved_thread = current_thread; |
| 4706 | current_thread = thread; |
| 4707 | |
| 4708 | lwp->bp_reinsert = pc; |
| 4709 | uninsert_breakpoints_at (pc); |
| 4710 | uninsert_fast_tracepoint_jumps_at (pc); |
| 4711 | |
| 4712 | step = single_step (lwp); |
| 4713 | |
| 4714 | current_thread = saved_thread; |
| 4715 | |
| 4716 | resume_one_lwp (lwp, step, 0, NULL); |
| 4717 | |
| 4718 | /* Require next event from this LWP. */ |
| 4719 | step_over_bkpt = thread->id; |
| 4720 | } |
| 4721 | |
| 4722 | /* Finish a step-over. Reinsert the breakpoint we had uninserted in |
| 4723 | start_step_over, if still there, and delete any single-step |
| 4724 | breakpoints we've set, on non hardware single-step targets. */ |
| 4725 | |
| 4726 | static int |
| 4727 | finish_step_over (struct lwp_info *lwp) |
| 4728 | { |
| 4729 | if (lwp->bp_reinsert != 0) |
| 4730 | { |
| 4731 | struct thread_info *saved_thread = current_thread; |
| 4732 | |
| 4733 | if (debug_threads) |
| 4734 | debug_printf ("Finished step over.\n"); |
| 4735 | |
| 4736 | current_thread = get_lwp_thread (lwp); |
| 4737 | |
| 4738 | /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there |
| 4739 | may be no breakpoint to reinsert there by now. */ |
| 4740 | reinsert_breakpoints_at (lwp->bp_reinsert); |
| 4741 | reinsert_fast_tracepoint_jumps_at (lwp->bp_reinsert); |
| 4742 | |
| 4743 | lwp->bp_reinsert = 0; |
| 4744 | |
| 4745 | /* Delete any single-step breakpoints. No longer needed. We |
| 4746 | don't have to worry about other threads hitting this trap, |
| 4747 | and later not being able to explain it, because we were |
| 4748 | stepping over a breakpoint, and we hold all threads but |
| 4749 | LWP stopped while doing that. */ |
| 4750 | if (!can_hardware_single_step ()) |
| 4751 | { |
| 4752 | gdb_assert (has_single_step_breakpoints (current_thread)); |
| 4753 | delete_single_step_breakpoints (current_thread); |
| 4754 | } |
| 4755 | |
| 4756 | step_over_bkpt = null_ptid; |
| 4757 | current_thread = saved_thread; |
| 4758 | return 1; |
| 4759 | } |
| 4760 | else |
| 4761 | return 0; |
| 4762 | } |
| 4763 | |
| 4764 | void |
| 4765 | linux_process_target::complete_ongoing_step_over () |
| 4766 | { |
| 4767 | if (step_over_bkpt != null_ptid) |
| 4768 | { |
| 4769 | struct lwp_info *lwp; |
| 4770 | int wstat; |
| 4771 | int ret; |
| 4772 | |
| 4773 | if (debug_threads) |
| 4774 | debug_printf ("detach: step over in progress, finish it first\n"); |
| 4775 | |
| 4776 | /* Passing NULL_PTID as filter indicates we want all events to |
| 4777 | be left pending. Eventually this returns when there are no |
| 4778 | unwaited-for children left. */ |
| 4779 | ret = wait_for_event_filtered (minus_one_ptid, null_ptid, &wstat, |
| 4780 | __WALL); |
| 4781 | gdb_assert (ret == -1); |
| 4782 | |
| 4783 | lwp = find_lwp_pid (step_over_bkpt); |
| 4784 | if (lwp != NULL) |
| 4785 | finish_step_over (lwp); |
| 4786 | step_over_bkpt = null_ptid; |
| 4787 | unsuspend_all_lwps (lwp); |
| 4788 | } |
| 4789 | } |
| 4790 | |
| 4791 | void |
| 4792 | linux_process_target::resume_one_thread (thread_info *thread, |
| 4793 | bool leave_all_stopped) |
| 4794 | { |
| 4795 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 4796 | int leave_pending; |
| 4797 | |
| 4798 | if (lwp->resume == NULL) |
| 4799 | return; |
| 4800 | |
| 4801 | if (lwp->resume->kind == resume_stop) |
| 4802 | { |
| 4803 | if (debug_threads) |
| 4804 | debug_printf ("resume_stop request for LWP %ld\n", lwpid_of (thread)); |
| 4805 | |
| 4806 | if (!lwp->stopped) |
| 4807 | { |
| 4808 | if (debug_threads) |
| 4809 | debug_printf ("stopping LWP %ld\n", lwpid_of (thread)); |
| 4810 | |
| 4811 | /* Stop the thread, and wait for the event asynchronously, |
| 4812 | through the event loop. */ |
| 4813 | send_sigstop (lwp); |
| 4814 | } |
| 4815 | else |
| 4816 | { |
| 4817 | if (debug_threads) |
| 4818 | debug_printf ("already stopped LWP %ld\n", |
| 4819 | lwpid_of (thread)); |
| 4820 | |
| 4821 | /* The LWP may have been stopped in an internal event that |
| 4822 | was not meant to be notified back to GDB (e.g., gdbserver |
| 4823 | breakpoint), so we should be reporting a stop event in |
| 4824 | this case too. */ |
| 4825 | |
| 4826 | /* If the thread already has a pending SIGSTOP, this is a |
| 4827 | no-op. Otherwise, something later will presumably resume |
| 4828 | the thread and this will cause it to cancel any pending |
| 4829 | operation, due to last_resume_kind == resume_stop. If |
| 4830 | the thread already has a pending status to report, we |
| 4831 | will still report it the next time we wait - see |
| 4832 | status_pending_p_callback. */ |
| 4833 | |
| 4834 | /* If we already have a pending signal to report, then |
| 4835 | there's no need to queue a SIGSTOP, as this means we're |
| 4836 | midway through moving the LWP out of the jumppad, and we |
| 4837 | will report the pending signal as soon as that is |
| 4838 | finished. */ |
| 4839 | if (lwp->pending_signals_to_report == NULL) |
| 4840 | send_sigstop (lwp); |
| 4841 | } |
| 4842 | |
| 4843 | /* For stop requests, we're done. */ |
| 4844 | lwp->resume = NULL; |
| 4845 | thread->last_status.kind = TARGET_WAITKIND_IGNORE; |
| 4846 | return; |
| 4847 | } |
| 4848 | |
| 4849 | /* If this thread which is about to be resumed has a pending status, |
| 4850 | then don't resume it - we can just report the pending status. |
| 4851 | Likewise if it is suspended, because e.g., another thread is |
| 4852 | stepping past a breakpoint. Make sure to queue any signals that |
| 4853 | would otherwise be sent. In all-stop mode, we do this decision |
| 4854 | based on if *any* thread has a pending status. If there's a |
| 4855 | thread that needs the step-over-breakpoint dance, then don't |
| 4856 | resume any other thread but that particular one. */ |
| 4857 | leave_pending = (lwp->suspended |
| 4858 | || lwp->status_pending_p |
| 4859 | || leave_all_stopped); |
| 4860 | |
| 4861 | /* If we have a new signal, enqueue the signal. */ |
| 4862 | if (lwp->resume->sig != 0) |
| 4863 | { |
| 4864 | siginfo_t info, *info_p; |
| 4865 | |
| 4866 | /* If this is the same signal we were previously stopped by, |
| 4867 | make sure to queue its siginfo. */ |
| 4868 | if (WIFSTOPPED (lwp->last_status) |
| 4869 | && WSTOPSIG (lwp->last_status) == lwp->resume->sig |
| 4870 | && ptrace (PTRACE_GETSIGINFO, lwpid_of (thread), |
| 4871 | (PTRACE_TYPE_ARG3) 0, &info) == 0) |
| 4872 | info_p = &info; |
| 4873 | else |
| 4874 | info_p = NULL; |
| 4875 | |
| 4876 | enqueue_pending_signal (lwp, lwp->resume->sig, info_p); |
| 4877 | } |
| 4878 | |
| 4879 | if (!leave_pending) |
| 4880 | { |
| 4881 | if (debug_threads) |
| 4882 | debug_printf ("resuming LWP %ld\n", lwpid_of (thread)); |
| 4883 | |
| 4884 | proceed_one_lwp (thread, NULL); |
| 4885 | } |
| 4886 | else |
| 4887 | { |
| 4888 | if (debug_threads) |
| 4889 | debug_printf ("leaving LWP %ld stopped\n", lwpid_of (thread)); |
| 4890 | } |
| 4891 | |
| 4892 | thread->last_status.kind = TARGET_WAITKIND_IGNORE; |
| 4893 | lwp->resume = NULL; |
| 4894 | } |
| 4895 | |
| 4896 | void |
| 4897 | linux_process_target::resume (thread_resume *resume_info, size_t n) |
| 4898 | { |
| 4899 | struct thread_info *need_step_over = NULL; |
| 4900 | |
| 4901 | if (debug_threads) |
| 4902 | { |
| 4903 | debug_enter (); |
| 4904 | debug_printf ("linux_resume:\n"); |
| 4905 | } |
| 4906 | |
| 4907 | for_each_thread ([&] (thread_info *thread) |
| 4908 | { |
| 4909 | linux_set_resume_request (thread, resume_info, n); |
| 4910 | }); |
| 4911 | |
| 4912 | /* If there is a thread which would otherwise be resumed, which has |
| 4913 | a pending status, then don't resume any threads - we can just |
| 4914 | report the pending status. Make sure to queue any signals that |
| 4915 | would otherwise be sent. In non-stop mode, we'll apply this |
| 4916 | logic to each thread individually. We consume all pending events |
| 4917 | before considering to start a step-over (in all-stop). */ |
| 4918 | bool any_pending = false; |
| 4919 | if (!non_stop) |
| 4920 | any_pending = find_thread ([this] (thread_info *thread) |
| 4921 | { |
| 4922 | return resume_status_pending (thread); |
| 4923 | }) != nullptr; |
| 4924 | |
| 4925 | /* If there is a thread which would otherwise be resumed, which is |
| 4926 | stopped at a breakpoint that needs stepping over, then don't |
| 4927 | resume any threads - have it step over the breakpoint with all |
| 4928 | other threads stopped, then resume all threads again. Make sure |
| 4929 | to queue any signals that would otherwise be delivered or |
| 4930 | queued. */ |
| 4931 | if (!any_pending && low_supports_breakpoints ()) |
| 4932 | need_step_over = find_thread ([this] (thread_info *thread) |
| 4933 | { |
| 4934 | return thread_needs_step_over (thread); |
| 4935 | }); |
| 4936 | |
| 4937 | bool leave_all_stopped = (need_step_over != NULL || any_pending); |
| 4938 | |
| 4939 | if (debug_threads) |
| 4940 | { |
| 4941 | if (need_step_over != NULL) |
| 4942 | debug_printf ("Not resuming all, need step over\n"); |
| 4943 | else if (any_pending) |
| 4944 | debug_printf ("Not resuming, all-stop and found " |
| 4945 | "an LWP with pending status\n"); |
| 4946 | else |
| 4947 | debug_printf ("Resuming, no pending status or step over needed\n"); |
| 4948 | } |
| 4949 | |
| 4950 | /* Even if we're leaving threads stopped, queue all signals we'd |
| 4951 | otherwise deliver. */ |
| 4952 | for_each_thread ([&] (thread_info *thread) |
| 4953 | { |
| 4954 | resume_one_thread (thread, leave_all_stopped); |
| 4955 | }); |
| 4956 | |
| 4957 | if (need_step_over) |
| 4958 | start_step_over (get_thread_lwp (need_step_over)); |
| 4959 | |
| 4960 | if (debug_threads) |
| 4961 | { |
| 4962 | debug_printf ("linux_resume done\n"); |
| 4963 | debug_exit (); |
| 4964 | } |
| 4965 | |
| 4966 | /* We may have events that were pending that can/should be sent to |
| 4967 | the client now. Trigger a linux_wait call. */ |
| 4968 | if (target_is_async_p ()) |
| 4969 | async_file_mark (); |
| 4970 | } |
| 4971 | |
| 4972 | void |
| 4973 | linux_process_target::proceed_one_lwp (thread_info *thread, lwp_info *except) |
| 4974 | { |
| 4975 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 4976 | int step; |
| 4977 | |
| 4978 | if (lwp == except) |
| 4979 | return; |
| 4980 | |
| 4981 | if (debug_threads) |
| 4982 | debug_printf ("proceed_one_lwp: lwp %ld\n", lwpid_of (thread)); |
| 4983 | |
| 4984 | if (!lwp->stopped) |
| 4985 | { |
| 4986 | if (debug_threads) |
| 4987 | debug_printf (" LWP %ld already running\n", lwpid_of (thread)); |
| 4988 | return; |
| 4989 | } |
| 4990 | |
| 4991 | if (thread->last_resume_kind == resume_stop |
| 4992 | && thread->last_status.kind != TARGET_WAITKIND_IGNORE) |
| 4993 | { |
| 4994 | if (debug_threads) |
| 4995 | debug_printf (" client wants LWP to remain %ld stopped\n", |
| 4996 | lwpid_of (thread)); |
| 4997 | return; |
| 4998 | } |
| 4999 | |
| 5000 | if (lwp->status_pending_p) |
| 5001 | { |
| 5002 | if (debug_threads) |
| 5003 | debug_printf (" LWP %ld has pending status, leaving stopped\n", |
| 5004 | lwpid_of (thread)); |
| 5005 | return; |
| 5006 | } |
| 5007 | |
| 5008 | gdb_assert (lwp->suspended >= 0); |
| 5009 | |
| 5010 | if (lwp->suspended) |
| 5011 | { |
| 5012 | if (debug_threads) |
| 5013 | debug_printf (" LWP %ld is suspended\n", lwpid_of (thread)); |
| 5014 | return; |
| 5015 | } |
| 5016 | |
| 5017 | if (thread->last_resume_kind == resume_stop |
| 5018 | && lwp->pending_signals_to_report == NULL |
| 5019 | && (lwp->collecting_fast_tracepoint |
| 5020 | == fast_tpoint_collect_result::not_collecting)) |
| 5021 | { |
| 5022 | /* We haven't reported this LWP as stopped yet (otherwise, the |
| 5023 | last_status.kind check above would catch it, and we wouldn't |
| 5024 | reach here. This LWP may have been momentarily paused by a |
| 5025 | stop_all_lwps call while handling for example, another LWP's |
| 5026 | step-over. In that case, the pending expected SIGSTOP signal |
| 5027 | that was queued at vCont;t handling time will have already |
| 5028 | been consumed by wait_for_sigstop, and so we need to requeue |
| 5029 | another one here. Note that if the LWP already has a SIGSTOP |
| 5030 | pending, this is a no-op. */ |
| 5031 | |
| 5032 | if (debug_threads) |
| 5033 | debug_printf ("Client wants LWP %ld to stop. " |
| 5034 | "Making sure it has a SIGSTOP pending\n", |
| 5035 | lwpid_of (thread)); |
| 5036 | |
| 5037 | send_sigstop (lwp); |
| 5038 | } |
| 5039 | |
| 5040 | if (thread->last_resume_kind == resume_step) |
| 5041 | { |
| 5042 | if (debug_threads) |
| 5043 | debug_printf (" stepping LWP %ld, client wants it stepping\n", |
| 5044 | lwpid_of (thread)); |
| 5045 | |
| 5046 | /* If resume_step is requested by GDB, install single-step |
| 5047 | breakpoints when the thread is about to be actually resumed if |
| 5048 | the single-step breakpoints weren't removed. */ |
| 5049 | if (supports_software_single_step () |
| 5050 | && !has_single_step_breakpoints (thread)) |
| 5051 | install_software_single_step_breakpoints (lwp); |
| 5052 | |
| 5053 | step = maybe_hw_step (thread); |
| 5054 | } |
| 5055 | else if (lwp->bp_reinsert != 0) |
| 5056 | { |
| 5057 | if (debug_threads) |
| 5058 | debug_printf (" stepping LWP %ld, reinsert set\n", |
| 5059 | lwpid_of (thread)); |
| 5060 | |
| 5061 | step = maybe_hw_step (thread); |
| 5062 | } |
| 5063 | else |
| 5064 | step = 0; |
| 5065 | |
| 5066 | resume_one_lwp (lwp, step, 0, NULL); |
| 5067 | } |
| 5068 | |
| 5069 | void |
| 5070 | linux_process_target::unsuspend_and_proceed_one_lwp (thread_info *thread, |
| 5071 | lwp_info *except) |
| 5072 | { |
| 5073 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 5074 | |
| 5075 | if (lwp == except) |
| 5076 | return; |
| 5077 | |
| 5078 | lwp_suspended_decr (lwp); |
| 5079 | |
| 5080 | proceed_one_lwp (thread, except); |
| 5081 | } |
| 5082 | |
| 5083 | void |
| 5084 | linux_process_target::proceed_all_lwps () |
| 5085 | { |
| 5086 | struct thread_info *need_step_over; |
| 5087 | |
| 5088 | /* If there is a thread which would otherwise be resumed, which is |
| 5089 | stopped at a breakpoint that needs stepping over, then don't |
| 5090 | resume any threads - have it step over the breakpoint with all |
| 5091 | other threads stopped, then resume all threads again. */ |
| 5092 | |
| 5093 | if (low_supports_breakpoints ()) |
| 5094 | { |
| 5095 | need_step_over = find_thread ([this] (thread_info *thread) |
| 5096 | { |
| 5097 | return thread_needs_step_over (thread); |
| 5098 | }); |
| 5099 | |
| 5100 | if (need_step_over != NULL) |
| 5101 | { |
| 5102 | if (debug_threads) |
| 5103 | debug_printf ("proceed_all_lwps: found " |
| 5104 | "thread %ld needing a step-over\n", |
| 5105 | lwpid_of (need_step_over)); |
| 5106 | |
| 5107 | start_step_over (get_thread_lwp (need_step_over)); |
| 5108 | return; |
| 5109 | } |
| 5110 | } |
| 5111 | |
| 5112 | if (debug_threads) |
| 5113 | debug_printf ("Proceeding, no step-over needed\n"); |
| 5114 | |
| 5115 | for_each_thread ([this] (thread_info *thread) |
| 5116 | { |
| 5117 | proceed_one_lwp (thread, NULL); |
| 5118 | }); |
| 5119 | } |
| 5120 | |
| 5121 | void |
| 5122 | linux_process_target::unstop_all_lwps (int unsuspend, lwp_info *except) |
| 5123 | { |
| 5124 | if (debug_threads) |
| 5125 | { |
| 5126 | debug_enter (); |
| 5127 | if (except) |
| 5128 | debug_printf ("unstopping all lwps, except=(LWP %ld)\n", |
| 5129 | lwpid_of (get_lwp_thread (except))); |
| 5130 | else |
| 5131 | debug_printf ("unstopping all lwps\n"); |
| 5132 | } |
| 5133 | |
| 5134 | if (unsuspend) |
| 5135 | for_each_thread ([&] (thread_info *thread) |
| 5136 | { |
| 5137 | unsuspend_and_proceed_one_lwp (thread, except); |
| 5138 | }); |
| 5139 | else |
| 5140 | for_each_thread ([&] (thread_info *thread) |
| 5141 | { |
| 5142 | proceed_one_lwp (thread, except); |
| 5143 | }); |
| 5144 | |
| 5145 | if (debug_threads) |
| 5146 | { |
| 5147 | debug_printf ("unstop_all_lwps done\n"); |
| 5148 | debug_exit (); |
| 5149 | } |
| 5150 | } |
| 5151 | |
| 5152 | |
| 5153 | #ifdef HAVE_LINUX_REGSETS |
| 5154 | |
| 5155 | #define use_linux_regsets 1 |
| 5156 | |
| 5157 | /* Returns true if REGSET has been disabled. */ |
| 5158 | |
| 5159 | static int |
| 5160 | regset_disabled (struct regsets_info *info, struct regset_info *regset) |
| 5161 | { |
| 5162 | return (info->disabled_regsets != NULL |
| 5163 | && info->disabled_regsets[regset - info->regsets]); |
| 5164 | } |
| 5165 | |
| 5166 | /* Disable REGSET. */ |
| 5167 | |
| 5168 | static void |
| 5169 | disable_regset (struct regsets_info *info, struct regset_info *regset) |
| 5170 | { |
| 5171 | int dr_offset; |
| 5172 | |
| 5173 | dr_offset = regset - info->regsets; |
| 5174 | if (info->disabled_regsets == NULL) |
| 5175 | info->disabled_regsets = (char *) xcalloc (1, info->num_regsets); |
| 5176 | info->disabled_regsets[dr_offset] = 1; |
| 5177 | } |
| 5178 | |
| 5179 | static int |
| 5180 | regsets_fetch_inferior_registers (struct regsets_info *regsets_info, |
| 5181 | struct regcache *regcache) |
| 5182 | { |
| 5183 | struct regset_info *regset; |
| 5184 | int saw_general_regs = 0; |
| 5185 | int pid; |
| 5186 | struct iovec iov; |
| 5187 | |
| 5188 | pid = lwpid_of (current_thread); |
| 5189 | for (regset = regsets_info->regsets; regset->size >= 0; regset++) |
| 5190 | { |
| 5191 | void *buf, *data; |
| 5192 | int nt_type, res; |
| 5193 | |
| 5194 | if (regset->size == 0 || regset_disabled (regsets_info, regset)) |
| 5195 | continue; |
| 5196 | |
| 5197 | buf = xmalloc (regset->size); |
| 5198 | |
| 5199 | nt_type = regset->nt_type; |
| 5200 | if (nt_type) |
| 5201 | { |
| 5202 | iov.iov_base = buf; |
| 5203 | iov.iov_len = regset->size; |
| 5204 | data = (void *) &iov; |
| 5205 | } |
| 5206 | else |
| 5207 | data = buf; |
| 5208 | |
| 5209 | #ifndef __sparc__ |
| 5210 | res = ptrace (regset->get_request, pid, |
| 5211 | (PTRACE_TYPE_ARG3) (long) nt_type, data); |
| 5212 | #else |
| 5213 | res = ptrace (regset->get_request, pid, data, nt_type); |
| 5214 | #endif |
| 5215 | if (res < 0) |
| 5216 | { |
| 5217 | if (errno == EIO |
| 5218 | || (errno == EINVAL && regset->type == OPTIONAL_REGS)) |
| 5219 | { |
| 5220 | /* If we get EIO on a regset, or an EINVAL and the regset is |
| 5221 | optional, do not try it again for this process mode. */ |
| 5222 | disable_regset (regsets_info, regset); |
| 5223 | } |
| 5224 | else if (errno == ENODATA) |
| 5225 | { |
| 5226 | /* ENODATA may be returned if the regset is currently |
| 5227 | not "active". This can happen in normal operation, |
| 5228 | so suppress the warning in this case. */ |
| 5229 | } |
| 5230 | else if (errno == ESRCH) |
| 5231 | { |
| 5232 | /* At this point, ESRCH should mean the process is |
| 5233 | already gone, in which case we simply ignore attempts |
| 5234 | to read its registers. */ |
| 5235 | } |
| 5236 | else |
| 5237 | { |
| 5238 | char s[256]; |
| 5239 | sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d", |
| 5240 | pid); |
| 5241 | perror (s); |
| 5242 | } |
| 5243 | } |
| 5244 | else |
| 5245 | { |
| 5246 | if (regset->type == GENERAL_REGS) |
| 5247 | saw_general_regs = 1; |
| 5248 | regset->store_function (regcache, buf); |
| 5249 | } |
| 5250 | free (buf); |
| 5251 | } |
| 5252 | if (saw_general_regs) |
| 5253 | return 0; |
| 5254 | else |
| 5255 | return 1; |
| 5256 | } |
| 5257 | |
| 5258 | static int |
| 5259 | regsets_store_inferior_registers (struct regsets_info *regsets_info, |
| 5260 | struct regcache *regcache) |
| 5261 | { |
| 5262 | struct regset_info *regset; |
| 5263 | int saw_general_regs = 0; |
| 5264 | int pid; |
| 5265 | struct iovec iov; |
| 5266 | |
| 5267 | pid = lwpid_of (current_thread); |
| 5268 | for (regset = regsets_info->regsets; regset->size >= 0; regset++) |
| 5269 | { |
| 5270 | void *buf, *data; |
| 5271 | int nt_type, res; |
| 5272 | |
| 5273 | if (regset->size == 0 || regset_disabled (regsets_info, regset) |
| 5274 | || regset->fill_function == NULL) |
| 5275 | continue; |
| 5276 | |
| 5277 | buf = xmalloc (regset->size); |
| 5278 | |
| 5279 | /* First fill the buffer with the current register set contents, |
| 5280 | in case there are any items in the kernel's regset that are |
| 5281 | not in gdbserver's regcache. */ |
| 5282 | |
| 5283 | nt_type = regset->nt_type; |
| 5284 | if (nt_type) |
| 5285 | { |
| 5286 | iov.iov_base = buf; |
| 5287 | iov.iov_len = regset->size; |
| 5288 | data = (void *) &iov; |
| 5289 | } |
| 5290 | else |
| 5291 | data = buf; |
| 5292 | |
| 5293 | #ifndef __sparc__ |
| 5294 | res = ptrace (regset->get_request, pid, |
| 5295 | (PTRACE_TYPE_ARG3) (long) nt_type, data); |
| 5296 | #else |
| 5297 | res = ptrace (regset->get_request, pid, data, nt_type); |
| 5298 | #endif |
| 5299 | |
| 5300 | if (res == 0) |
| 5301 | { |
| 5302 | /* Then overlay our cached registers on that. */ |
| 5303 | regset->fill_function (regcache, buf); |
| 5304 | |
| 5305 | /* Only now do we write the register set. */ |
| 5306 | #ifndef __sparc__ |
| 5307 | res = ptrace (regset->set_request, pid, |
| 5308 | (PTRACE_TYPE_ARG3) (long) nt_type, data); |
| 5309 | #else |
| 5310 | res = ptrace (regset->set_request, pid, data, nt_type); |
| 5311 | #endif |
| 5312 | } |
| 5313 | |
| 5314 | if (res < 0) |
| 5315 | { |
| 5316 | if (errno == EIO |
| 5317 | || (errno == EINVAL && regset->type == OPTIONAL_REGS)) |
| 5318 | { |
| 5319 | /* If we get EIO on a regset, or an EINVAL and the regset is |
| 5320 | optional, do not try it again for this process mode. */ |
| 5321 | disable_regset (regsets_info, regset); |
| 5322 | } |
| 5323 | else if (errno == ESRCH) |
| 5324 | { |
| 5325 | /* At this point, ESRCH should mean the process is |
| 5326 | already gone, in which case we simply ignore attempts |
| 5327 | to change its registers. See also the related |
| 5328 | comment in resume_one_lwp. */ |
| 5329 | free (buf); |
| 5330 | return 0; |
| 5331 | } |
| 5332 | else |
| 5333 | { |
| 5334 | perror ("Warning: ptrace(regsets_store_inferior_registers)"); |
| 5335 | } |
| 5336 | } |
| 5337 | else if (regset->type == GENERAL_REGS) |
| 5338 | saw_general_regs = 1; |
| 5339 | free (buf); |
| 5340 | } |
| 5341 | if (saw_general_regs) |
| 5342 | return 0; |
| 5343 | else |
| 5344 | return 1; |
| 5345 | } |
| 5346 | |
| 5347 | #else /* !HAVE_LINUX_REGSETS */ |
| 5348 | |
| 5349 | #define use_linux_regsets 0 |
| 5350 | #define regsets_fetch_inferior_registers(regsets_info, regcache) 1 |
| 5351 | #define regsets_store_inferior_registers(regsets_info, regcache) 1 |
| 5352 | |
| 5353 | #endif |
| 5354 | |
| 5355 | /* Return 1 if register REGNO is supported by one of the regset ptrace |
| 5356 | calls or 0 if it has to be transferred individually. */ |
| 5357 | |
| 5358 | static int |
| 5359 | linux_register_in_regsets (const struct regs_info *regs_info, int regno) |
| 5360 | { |
| 5361 | unsigned char mask = 1 << (regno % 8); |
| 5362 | size_t index = regno / 8; |
| 5363 | |
| 5364 | return (use_linux_regsets |
| 5365 | && (regs_info->regset_bitmap == NULL |
| 5366 | || (regs_info->regset_bitmap[index] & mask) != 0)); |
| 5367 | } |
| 5368 | |
| 5369 | #ifdef HAVE_LINUX_USRREGS |
| 5370 | |
| 5371 | static int |
| 5372 | register_addr (const struct usrregs_info *usrregs, int regnum) |
| 5373 | { |
| 5374 | int addr; |
| 5375 | |
| 5376 | if (regnum < 0 || regnum >= usrregs->num_regs) |
| 5377 | error ("Invalid register number %d.", regnum); |
| 5378 | |
| 5379 | addr = usrregs->regmap[regnum]; |
| 5380 | |
| 5381 | return addr; |
| 5382 | } |
| 5383 | |
| 5384 | |
| 5385 | void |
| 5386 | linux_process_target::fetch_register (const usrregs_info *usrregs, |
| 5387 | regcache *regcache, int regno) |
| 5388 | { |
| 5389 | CORE_ADDR regaddr; |
| 5390 | int i, size; |
| 5391 | char *buf; |
| 5392 | int pid; |
| 5393 | |
| 5394 | if (regno >= usrregs->num_regs) |
| 5395 | return; |
| 5396 | if (low_cannot_fetch_register (regno)) |
| 5397 | return; |
| 5398 | |
| 5399 | regaddr = register_addr (usrregs, regno); |
| 5400 | if (regaddr == -1) |
| 5401 | return; |
| 5402 | |
| 5403 | size = ((register_size (regcache->tdesc, regno) |
| 5404 | + sizeof (PTRACE_XFER_TYPE) - 1) |
| 5405 | & -sizeof (PTRACE_XFER_TYPE)); |
| 5406 | buf = (char *) alloca (size); |
| 5407 | |
| 5408 | pid = lwpid_of (current_thread); |
| 5409 | for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE)) |
| 5410 | { |
| 5411 | errno = 0; |
| 5412 | *(PTRACE_XFER_TYPE *) (buf + i) = |
| 5413 | ptrace (PTRACE_PEEKUSER, pid, |
| 5414 | /* Coerce to a uintptr_t first to avoid potential gcc warning |
| 5415 | of coercing an 8 byte integer to a 4 byte pointer. */ |
| 5416 | (PTRACE_TYPE_ARG3) (uintptr_t) regaddr, (PTRACE_TYPE_ARG4) 0); |
| 5417 | regaddr += sizeof (PTRACE_XFER_TYPE); |
| 5418 | if (errno != 0) |
| 5419 | { |
| 5420 | /* Mark register REGNO unavailable. */ |
| 5421 | supply_register (regcache, regno, NULL); |
| 5422 | return; |
| 5423 | } |
| 5424 | } |
| 5425 | |
| 5426 | if (the_low_target.supply_ptrace_register) |
| 5427 | the_low_target.supply_ptrace_register (regcache, regno, buf); |
| 5428 | else |
| 5429 | supply_register (regcache, regno, buf); |
| 5430 | } |
| 5431 | |
| 5432 | void |
| 5433 | linux_process_target::store_register (const usrregs_info *usrregs, |
| 5434 | regcache *regcache, int regno) |
| 5435 | { |
| 5436 | CORE_ADDR regaddr; |
| 5437 | int i, size; |
| 5438 | char *buf; |
| 5439 | int pid; |
| 5440 | |
| 5441 | if (regno >= usrregs->num_regs) |
| 5442 | return; |
| 5443 | if (low_cannot_store_register (regno)) |
| 5444 | return; |
| 5445 | |
| 5446 | regaddr = register_addr (usrregs, regno); |
| 5447 | if (regaddr == -1) |
| 5448 | return; |
| 5449 | |
| 5450 | size = ((register_size (regcache->tdesc, regno) |
| 5451 | + sizeof (PTRACE_XFER_TYPE) - 1) |
| 5452 | & -sizeof (PTRACE_XFER_TYPE)); |
| 5453 | buf = (char *) alloca (size); |
| 5454 | memset (buf, 0, size); |
| 5455 | |
| 5456 | if (the_low_target.collect_ptrace_register) |
| 5457 | the_low_target.collect_ptrace_register (regcache, regno, buf); |
| 5458 | else |
| 5459 | collect_register (regcache, regno, buf); |
| 5460 | |
| 5461 | pid = lwpid_of (current_thread); |
| 5462 | for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE)) |
| 5463 | { |
| 5464 | errno = 0; |
| 5465 | ptrace (PTRACE_POKEUSER, pid, |
| 5466 | /* Coerce to a uintptr_t first to avoid potential gcc warning |
| 5467 | about coercing an 8 byte integer to a 4 byte pointer. */ |
| 5468 | (PTRACE_TYPE_ARG3) (uintptr_t) regaddr, |
| 5469 | (PTRACE_TYPE_ARG4) *(PTRACE_XFER_TYPE *) (buf + i)); |
| 5470 | if (errno != 0) |
| 5471 | { |
| 5472 | /* At this point, ESRCH should mean the process is |
| 5473 | already gone, in which case we simply ignore attempts |
| 5474 | to change its registers. See also the related |
| 5475 | comment in resume_one_lwp. */ |
| 5476 | if (errno == ESRCH) |
| 5477 | return; |
| 5478 | |
| 5479 | |
| 5480 | if (!low_cannot_store_register (regno)) |
| 5481 | error ("writing register %d: %s", regno, safe_strerror (errno)); |
| 5482 | } |
| 5483 | regaddr += sizeof (PTRACE_XFER_TYPE); |
| 5484 | } |
| 5485 | } |
| 5486 | #endif /* HAVE_LINUX_USRREGS */ |
| 5487 | |
| 5488 | void |
| 5489 | linux_process_target::usr_fetch_inferior_registers (const regs_info *regs_info, |
| 5490 | regcache *regcache, |
| 5491 | int regno, int all) |
| 5492 | { |
| 5493 | #ifdef HAVE_LINUX_USRREGS |
| 5494 | struct usrregs_info *usr = regs_info->usrregs; |
| 5495 | |
| 5496 | if (regno == -1) |
| 5497 | { |
| 5498 | for (regno = 0; regno < usr->num_regs; regno++) |
| 5499 | if (all || !linux_register_in_regsets (regs_info, regno)) |
| 5500 | fetch_register (usr, regcache, regno); |
| 5501 | } |
| 5502 | else |
| 5503 | fetch_register (usr, regcache, regno); |
| 5504 | #endif |
| 5505 | } |
| 5506 | |
| 5507 | void |
| 5508 | linux_process_target::usr_store_inferior_registers (const regs_info *regs_info, |
| 5509 | regcache *regcache, |
| 5510 | int regno, int all) |
| 5511 | { |
| 5512 | #ifdef HAVE_LINUX_USRREGS |
| 5513 | struct usrregs_info *usr = regs_info->usrregs; |
| 5514 | |
| 5515 | if (regno == -1) |
| 5516 | { |
| 5517 | for (regno = 0; regno < usr->num_regs; regno++) |
| 5518 | if (all || !linux_register_in_regsets (regs_info, regno)) |
| 5519 | store_register (usr, regcache, regno); |
| 5520 | } |
| 5521 | else |
| 5522 | store_register (usr, regcache, regno); |
| 5523 | #endif |
| 5524 | } |
| 5525 | |
| 5526 | void |
| 5527 | linux_process_target::fetch_registers (regcache *regcache, int regno) |
| 5528 | { |
| 5529 | int use_regsets; |
| 5530 | int all = 0; |
| 5531 | const regs_info *regs_info = get_regs_info (); |
| 5532 | |
| 5533 | if (regno == -1) |
| 5534 | { |
| 5535 | if (regs_info->usrregs != NULL) |
| 5536 | for (regno = 0; regno < regs_info->usrregs->num_regs; regno++) |
| 5537 | low_fetch_register (regcache, regno); |
| 5538 | |
| 5539 | all = regsets_fetch_inferior_registers (regs_info->regsets_info, regcache); |
| 5540 | if (regs_info->usrregs != NULL) |
| 5541 | usr_fetch_inferior_registers (regs_info, regcache, -1, all); |
| 5542 | } |
| 5543 | else |
| 5544 | { |
| 5545 | if (low_fetch_register (regcache, regno)) |
| 5546 | return; |
| 5547 | |
| 5548 | use_regsets = linux_register_in_regsets (regs_info, regno); |
| 5549 | if (use_regsets) |
| 5550 | all = regsets_fetch_inferior_registers (regs_info->regsets_info, |
| 5551 | regcache); |
| 5552 | if ((!use_regsets || all) && regs_info->usrregs != NULL) |
| 5553 | usr_fetch_inferior_registers (regs_info, regcache, regno, 1); |
| 5554 | } |
| 5555 | } |
| 5556 | |
| 5557 | void |
| 5558 | linux_process_target::store_registers (regcache *regcache, int regno) |
| 5559 | { |
| 5560 | int use_regsets; |
| 5561 | int all = 0; |
| 5562 | const regs_info *regs_info = get_regs_info (); |
| 5563 | |
| 5564 | if (regno == -1) |
| 5565 | { |
| 5566 | all = regsets_store_inferior_registers (regs_info->regsets_info, |
| 5567 | regcache); |
| 5568 | if (regs_info->usrregs != NULL) |
| 5569 | usr_store_inferior_registers (regs_info, regcache, regno, all); |
| 5570 | } |
| 5571 | else |
| 5572 | { |
| 5573 | use_regsets = linux_register_in_regsets (regs_info, regno); |
| 5574 | if (use_regsets) |
| 5575 | all = regsets_store_inferior_registers (regs_info->regsets_info, |
| 5576 | regcache); |
| 5577 | if ((!use_regsets || all) && regs_info->usrregs != NULL) |
| 5578 | usr_store_inferior_registers (regs_info, regcache, regno, 1); |
| 5579 | } |
| 5580 | } |
| 5581 | |
| 5582 | bool |
| 5583 | linux_process_target::low_fetch_register (regcache *regcache, int regno) |
| 5584 | { |
| 5585 | return false; |
| 5586 | } |
| 5587 | |
| 5588 | /* A wrapper for the read_memory target op. */ |
| 5589 | |
| 5590 | static int |
| 5591 | linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len) |
| 5592 | { |
| 5593 | return the_target->read_memory (memaddr, myaddr, len); |
| 5594 | } |
| 5595 | |
| 5596 | /* Copy LEN bytes from inferior's memory starting at MEMADDR |
| 5597 | to debugger memory starting at MYADDR. */ |
| 5598 | |
| 5599 | int |
| 5600 | linux_process_target::read_memory (CORE_ADDR memaddr, |
| 5601 | unsigned char *myaddr, int len) |
| 5602 | { |
| 5603 | int pid = lwpid_of (current_thread); |
| 5604 | PTRACE_XFER_TYPE *buffer; |
| 5605 | CORE_ADDR addr; |
| 5606 | int count; |
| 5607 | char filename[64]; |
| 5608 | int i; |
| 5609 | int ret; |
| 5610 | int fd; |
| 5611 | |
| 5612 | /* Try using /proc. Don't bother for one word. */ |
| 5613 | if (len >= 3 * sizeof (long)) |
| 5614 | { |
| 5615 | int bytes; |
| 5616 | |
| 5617 | /* We could keep this file open and cache it - possibly one per |
| 5618 | thread. That requires some juggling, but is even faster. */ |
| 5619 | sprintf (filename, "/proc/%d/mem", pid); |
| 5620 | fd = open (filename, O_RDONLY | O_LARGEFILE); |
| 5621 | if (fd == -1) |
| 5622 | goto no_proc; |
| 5623 | |
| 5624 | /* If pread64 is available, use it. It's faster if the kernel |
| 5625 | supports it (only one syscall), and it's 64-bit safe even on |
| 5626 | 32-bit platforms (for instance, SPARC debugging a SPARC64 |
| 5627 | application). */ |
| 5628 | #ifdef HAVE_PREAD64 |
| 5629 | bytes = pread64 (fd, myaddr, len, memaddr); |
| 5630 | #else |
| 5631 | bytes = -1; |
| 5632 | if (lseek (fd, memaddr, SEEK_SET) != -1) |
| 5633 | bytes = read (fd, myaddr, len); |
| 5634 | #endif |
| 5635 | |
| 5636 | close (fd); |
| 5637 | if (bytes == len) |
| 5638 | return 0; |
| 5639 | |
| 5640 | /* Some data was read, we'll try to get the rest with ptrace. */ |
| 5641 | if (bytes > 0) |
| 5642 | { |
| 5643 | memaddr += bytes; |
| 5644 | myaddr += bytes; |
| 5645 | len -= bytes; |
| 5646 | } |
| 5647 | } |
| 5648 | |
| 5649 | no_proc: |
| 5650 | /* Round starting address down to longword boundary. */ |
| 5651 | addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); |
| 5652 | /* Round ending address up; get number of longwords that makes. */ |
| 5653 | count = ((((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) |
| 5654 | / sizeof (PTRACE_XFER_TYPE)); |
| 5655 | /* Allocate buffer of that many longwords. */ |
| 5656 | buffer = XALLOCAVEC (PTRACE_XFER_TYPE, count); |
| 5657 | |
| 5658 | /* Read all the longwords */ |
| 5659 | errno = 0; |
| 5660 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) |
| 5661 | { |
| 5662 | /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning |
| 5663 | about coercing an 8 byte integer to a 4 byte pointer. */ |
| 5664 | buffer[i] = ptrace (PTRACE_PEEKTEXT, pid, |
| 5665 | (PTRACE_TYPE_ARG3) (uintptr_t) addr, |
| 5666 | (PTRACE_TYPE_ARG4) 0); |
| 5667 | if (errno) |
| 5668 | break; |
| 5669 | } |
| 5670 | ret = errno; |
| 5671 | |
| 5672 | /* Copy appropriate bytes out of the buffer. */ |
| 5673 | if (i > 0) |
| 5674 | { |
| 5675 | i *= sizeof (PTRACE_XFER_TYPE); |
| 5676 | i -= memaddr & (sizeof (PTRACE_XFER_TYPE) - 1); |
| 5677 | memcpy (myaddr, |
| 5678 | (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), |
| 5679 | i < len ? i : len); |
| 5680 | } |
| 5681 | |
| 5682 | return ret; |
| 5683 | } |
| 5684 | |
| 5685 | /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's |
| 5686 | memory at MEMADDR. On failure (cannot write to the inferior) |
| 5687 | returns the value of errno. Always succeeds if LEN is zero. */ |
| 5688 | |
| 5689 | int |
| 5690 | linux_process_target::write_memory (CORE_ADDR memaddr, |
| 5691 | const unsigned char *myaddr, int len) |
| 5692 | { |
| 5693 | int i; |
| 5694 | /* Round starting address down to longword boundary. */ |
| 5695 | CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); |
| 5696 | /* Round ending address up; get number of longwords that makes. */ |
| 5697 | int count |
| 5698 | = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) |
| 5699 | / sizeof (PTRACE_XFER_TYPE); |
| 5700 | |
| 5701 | /* Allocate buffer of that many longwords. */ |
| 5702 | PTRACE_XFER_TYPE *buffer = XALLOCAVEC (PTRACE_XFER_TYPE, count); |
| 5703 | |
| 5704 | int pid = lwpid_of (current_thread); |
| 5705 | |
| 5706 | if (len == 0) |
| 5707 | { |
| 5708 | /* Zero length write always succeeds. */ |
| 5709 | return 0; |
| 5710 | } |
| 5711 | |
| 5712 | if (debug_threads) |
| 5713 | { |
| 5714 | /* Dump up to four bytes. */ |
| 5715 | char str[4 * 2 + 1]; |
| 5716 | char *p = str; |
| 5717 | int dump = len < 4 ? len : 4; |
| 5718 | |
| 5719 | for (i = 0; i < dump; i++) |
| 5720 | { |
| 5721 | sprintf (p, "%02x", myaddr[i]); |
| 5722 | p += 2; |
| 5723 | } |
| 5724 | *p = '\0'; |
| 5725 | |
| 5726 | debug_printf ("Writing %s to 0x%08lx in process %d\n", |
| 5727 | str, (long) memaddr, pid); |
| 5728 | } |
| 5729 | |
| 5730 | /* Fill start and end extra bytes of buffer with existing memory data. */ |
| 5731 | |
| 5732 | errno = 0; |
| 5733 | /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning |
| 5734 | about coercing an 8 byte integer to a 4 byte pointer. */ |
| 5735 | buffer[0] = ptrace (PTRACE_PEEKTEXT, pid, |
| 5736 | (PTRACE_TYPE_ARG3) (uintptr_t) addr, |
| 5737 | (PTRACE_TYPE_ARG4) 0); |
| 5738 | if (errno) |
| 5739 | return errno; |
| 5740 | |
| 5741 | if (count > 1) |
| 5742 | { |
| 5743 | errno = 0; |
| 5744 | buffer[count - 1] |
| 5745 | = ptrace (PTRACE_PEEKTEXT, pid, |
| 5746 | /* Coerce to a uintptr_t first to avoid potential gcc warning |
| 5747 | about coercing an 8 byte integer to a 4 byte pointer. */ |
| 5748 | (PTRACE_TYPE_ARG3) (uintptr_t) (addr + (count - 1) |
| 5749 | * sizeof (PTRACE_XFER_TYPE)), |
| 5750 | (PTRACE_TYPE_ARG4) 0); |
| 5751 | if (errno) |
| 5752 | return errno; |
| 5753 | } |
| 5754 | |
| 5755 | /* Copy data to be written over corresponding part of buffer. */ |
| 5756 | |
| 5757 | memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), |
| 5758 | myaddr, len); |
| 5759 | |
| 5760 | /* Write the entire buffer. */ |
| 5761 | |
| 5762 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) |
| 5763 | { |
| 5764 | errno = 0; |
| 5765 | ptrace (PTRACE_POKETEXT, pid, |
| 5766 | /* Coerce to a uintptr_t first to avoid potential gcc warning |
| 5767 | about coercing an 8 byte integer to a 4 byte pointer. */ |
| 5768 | (PTRACE_TYPE_ARG3) (uintptr_t) addr, |
| 5769 | (PTRACE_TYPE_ARG4) buffer[i]); |
| 5770 | if (errno) |
| 5771 | return errno; |
| 5772 | } |
| 5773 | |
| 5774 | return 0; |
| 5775 | } |
| 5776 | |
| 5777 | void |
| 5778 | linux_process_target::look_up_symbols () |
| 5779 | { |
| 5780 | #ifdef USE_THREAD_DB |
| 5781 | struct process_info *proc = current_process (); |
| 5782 | |
| 5783 | if (proc->priv->thread_db != NULL) |
| 5784 | return; |
| 5785 | |
| 5786 | thread_db_init (); |
| 5787 | #endif |
| 5788 | } |
| 5789 | |
| 5790 | void |
| 5791 | linux_process_target::request_interrupt () |
| 5792 | { |
| 5793 | /* Send a SIGINT to the process group. This acts just like the user |
| 5794 | typed a ^C on the controlling terminal. */ |
| 5795 | ::kill (-signal_pid, SIGINT); |
| 5796 | } |
| 5797 | |
| 5798 | bool |
| 5799 | linux_process_target::supports_read_auxv () |
| 5800 | { |
| 5801 | return true; |
| 5802 | } |
| 5803 | |
| 5804 | /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET |
| 5805 | to debugger memory starting at MYADDR. */ |
| 5806 | |
| 5807 | int |
| 5808 | linux_process_target::read_auxv (CORE_ADDR offset, unsigned char *myaddr, |
| 5809 | unsigned int len) |
| 5810 | { |
| 5811 | char filename[PATH_MAX]; |
| 5812 | int fd, n; |
| 5813 | int pid = lwpid_of (current_thread); |
| 5814 | |
| 5815 | xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid); |
| 5816 | |
| 5817 | fd = open (filename, O_RDONLY); |
| 5818 | if (fd < 0) |
| 5819 | return -1; |
| 5820 | |
| 5821 | if (offset != (CORE_ADDR) 0 |
| 5822 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) |
| 5823 | n = -1; |
| 5824 | else |
| 5825 | n = read (fd, myaddr, len); |
| 5826 | |
| 5827 | close (fd); |
| 5828 | |
| 5829 | return n; |
| 5830 | } |
| 5831 | |
| 5832 | int |
| 5833 | linux_process_target::insert_point (enum raw_bkpt_type type, CORE_ADDR addr, |
| 5834 | int size, raw_breakpoint *bp) |
| 5835 | { |
| 5836 | if (type == raw_bkpt_type_sw) |
| 5837 | return insert_memory_breakpoint (bp); |
| 5838 | else if (the_low_target.insert_point != NULL) |
| 5839 | return the_low_target.insert_point (type, addr, size, bp); |
| 5840 | else |
| 5841 | /* Unsupported (see target.h). */ |
| 5842 | return 1; |
| 5843 | } |
| 5844 | |
| 5845 | int |
| 5846 | linux_process_target::remove_point (enum raw_bkpt_type type, CORE_ADDR addr, |
| 5847 | int size, raw_breakpoint *bp) |
| 5848 | { |
| 5849 | if (type == raw_bkpt_type_sw) |
| 5850 | return remove_memory_breakpoint (bp); |
| 5851 | else if (the_low_target.remove_point != NULL) |
| 5852 | return the_low_target.remove_point (type, addr, size, bp); |
| 5853 | else |
| 5854 | /* Unsupported (see target.h). */ |
| 5855 | return 1; |
| 5856 | } |
| 5857 | |
| 5858 | /* Implement the stopped_by_sw_breakpoint target_ops |
| 5859 | method. */ |
| 5860 | |
| 5861 | bool |
| 5862 | linux_process_target::stopped_by_sw_breakpoint () |
| 5863 | { |
| 5864 | struct lwp_info *lwp = get_thread_lwp (current_thread); |
| 5865 | |
| 5866 | return (lwp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT); |
| 5867 | } |
| 5868 | |
| 5869 | /* Implement the supports_stopped_by_sw_breakpoint target_ops |
| 5870 | method. */ |
| 5871 | |
| 5872 | bool |
| 5873 | linux_process_target::supports_stopped_by_sw_breakpoint () |
| 5874 | { |
| 5875 | return USE_SIGTRAP_SIGINFO; |
| 5876 | } |
| 5877 | |
| 5878 | /* Implement the stopped_by_hw_breakpoint target_ops |
| 5879 | method. */ |
| 5880 | |
| 5881 | bool |
| 5882 | linux_process_target::stopped_by_hw_breakpoint () |
| 5883 | { |
| 5884 | struct lwp_info *lwp = get_thread_lwp (current_thread); |
| 5885 | |
| 5886 | return (lwp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT); |
| 5887 | } |
| 5888 | |
| 5889 | /* Implement the supports_stopped_by_hw_breakpoint target_ops |
| 5890 | method. */ |
| 5891 | |
| 5892 | bool |
| 5893 | linux_process_target::supports_stopped_by_hw_breakpoint () |
| 5894 | { |
| 5895 | return USE_SIGTRAP_SIGINFO; |
| 5896 | } |
| 5897 | |
| 5898 | /* Implement the supports_hardware_single_step target_ops method. */ |
| 5899 | |
| 5900 | bool |
| 5901 | linux_process_target::supports_hardware_single_step () |
| 5902 | { |
| 5903 | return can_hardware_single_step (); |
| 5904 | } |
| 5905 | |
| 5906 | bool |
| 5907 | linux_process_target::stopped_by_watchpoint () |
| 5908 | { |
| 5909 | struct lwp_info *lwp = get_thread_lwp (current_thread); |
| 5910 | |
| 5911 | return lwp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
| 5912 | } |
| 5913 | |
| 5914 | CORE_ADDR |
| 5915 | linux_process_target::stopped_data_address () |
| 5916 | { |
| 5917 | struct lwp_info *lwp = get_thread_lwp (current_thread); |
| 5918 | |
| 5919 | return lwp->stopped_data_address; |
| 5920 | } |
| 5921 | |
| 5922 | /* This is only used for targets that define PT_TEXT_ADDR, |
| 5923 | PT_DATA_ADDR and PT_TEXT_END_ADDR. If those are not defined, supposedly |
| 5924 | the target has different ways of acquiring this information, like |
| 5925 | loadmaps. */ |
| 5926 | |
| 5927 | bool |
| 5928 | linux_process_target::supports_read_offsets () |
| 5929 | { |
| 5930 | #ifdef SUPPORTS_READ_OFFSETS |
| 5931 | return true; |
| 5932 | #else |
| 5933 | return false; |
| 5934 | #endif |
| 5935 | } |
| 5936 | |
| 5937 | /* Under uClinux, programs are loaded at non-zero offsets, which we need |
| 5938 | to tell gdb about. */ |
| 5939 | |
| 5940 | int |
| 5941 | linux_process_target::read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p) |
| 5942 | { |
| 5943 | #ifdef SUPPORTS_READ_OFFSETS |
| 5944 | unsigned long text, text_end, data; |
| 5945 | int pid = lwpid_of (current_thread); |
| 5946 | |
| 5947 | errno = 0; |
| 5948 | |
| 5949 | text = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_TEXT_ADDR, |
| 5950 | (PTRACE_TYPE_ARG4) 0); |
| 5951 | text_end = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_TEXT_END_ADDR, |
| 5952 | (PTRACE_TYPE_ARG4) 0); |
| 5953 | data = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_DATA_ADDR, |
| 5954 | (PTRACE_TYPE_ARG4) 0); |
| 5955 | |
| 5956 | if (errno == 0) |
| 5957 | { |
| 5958 | /* Both text and data offsets produced at compile-time (and so |
| 5959 | used by gdb) are relative to the beginning of the program, |
| 5960 | with the data segment immediately following the text segment. |
| 5961 | However, the actual runtime layout in memory may put the data |
| 5962 | somewhere else, so when we send gdb a data base-address, we |
| 5963 | use the real data base address and subtract the compile-time |
| 5964 | data base-address from it (which is just the length of the |
| 5965 | text segment). BSS immediately follows data in both |
| 5966 | cases. */ |
| 5967 | *text_p = text; |
| 5968 | *data_p = data - (text_end - text); |
| 5969 | |
| 5970 | return 1; |
| 5971 | } |
| 5972 | return 0; |
| 5973 | #else |
| 5974 | gdb_assert_not_reached ("target op read_offsets not supported"); |
| 5975 | #endif |
| 5976 | } |
| 5977 | |
| 5978 | bool |
| 5979 | linux_process_target::supports_get_tls_address () |
| 5980 | { |
| 5981 | #ifdef USE_THREAD_DB |
| 5982 | return true; |
| 5983 | #else |
| 5984 | return false; |
| 5985 | #endif |
| 5986 | } |
| 5987 | |
| 5988 | int |
| 5989 | linux_process_target::get_tls_address (thread_info *thread, |
| 5990 | CORE_ADDR offset, |
| 5991 | CORE_ADDR load_module, |
| 5992 | CORE_ADDR *address) |
| 5993 | { |
| 5994 | #ifdef USE_THREAD_DB |
| 5995 | return thread_db_get_tls_address (thread, offset, load_module, address); |
| 5996 | #else |
| 5997 | return -1; |
| 5998 | #endif |
| 5999 | } |
| 6000 | |
| 6001 | bool |
| 6002 | linux_process_target::supports_qxfer_osdata () |
| 6003 | { |
| 6004 | return true; |
| 6005 | } |
| 6006 | |
| 6007 | int |
| 6008 | linux_process_target::qxfer_osdata (const char *annex, |
| 6009 | unsigned char *readbuf, |
| 6010 | unsigned const char *writebuf, |
| 6011 | CORE_ADDR offset, int len) |
| 6012 | { |
| 6013 | return linux_common_xfer_osdata (annex, readbuf, offset, len); |
| 6014 | } |
| 6015 | |
| 6016 | /* Convert a native/host siginfo object, into/from the siginfo in the |
| 6017 | layout of the inferiors' architecture. */ |
| 6018 | |
| 6019 | static void |
| 6020 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
| 6021 | { |
| 6022 | int done = 0; |
| 6023 | |
| 6024 | if (the_low_target.siginfo_fixup != NULL) |
| 6025 | done = the_low_target.siginfo_fixup (siginfo, inf_siginfo, direction); |
| 6026 | |
| 6027 | /* If there was no callback, or the callback didn't do anything, |
| 6028 | then just do a straight memcpy. */ |
| 6029 | if (!done) |
| 6030 | { |
| 6031 | if (direction == 1) |
| 6032 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
| 6033 | else |
| 6034 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
| 6035 | } |
| 6036 | } |
| 6037 | |
| 6038 | bool |
| 6039 | linux_process_target::supports_qxfer_siginfo () |
| 6040 | { |
| 6041 | return true; |
| 6042 | } |
| 6043 | |
| 6044 | int |
| 6045 | linux_process_target::qxfer_siginfo (const char *annex, |
| 6046 | unsigned char *readbuf, |
| 6047 | unsigned const char *writebuf, |
| 6048 | CORE_ADDR offset, int len) |
| 6049 | { |
| 6050 | int pid; |
| 6051 | siginfo_t siginfo; |
| 6052 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; |
| 6053 | |
| 6054 | if (current_thread == NULL) |
| 6055 | return -1; |
| 6056 | |
| 6057 | pid = lwpid_of (current_thread); |
| 6058 | |
| 6059 | if (debug_threads) |
| 6060 | debug_printf ("%s siginfo for lwp %d.\n", |
| 6061 | readbuf != NULL ? "Reading" : "Writing", |
| 6062 | pid); |
| 6063 | |
| 6064 | if (offset >= sizeof (siginfo)) |
| 6065 | return -1; |
| 6066 | |
| 6067 | if (ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo) != 0) |
| 6068 | return -1; |
| 6069 | |
| 6070 | /* When GDBSERVER is built as a 64-bit application, ptrace writes into |
| 6071 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit |
| 6072 | inferior with a 64-bit GDBSERVER should look the same as debugging it |
| 6073 | with a 32-bit GDBSERVER, we need to convert it. */ |
| 6074 | siginfo_fixup (&siginfo, inf_siginfo, 0); |
| 6075 | |
| 6076 | if (offset + len > sizeof (siginfo)) |
| 6077 | len = sizeof (siginfo) - offset; |
| 6078 | |
| 6079 | if (readbuf != NULL) |
| 6080 | memcpy (readbuf, inf_siginfo + offset, len); |
| 6081 | else |
| 6082 | { |
| 6083 | memcpy (inf_siginfo + offset, writebuf, len); |
| 6084 | |
| 6085 | /* Convert back to ptrace layout before flushing it out. */ |
| 6086 | siginfo_fixup (&siginfo, inf_siginfo, 1); |
| 6087 | |
| 6088 | if (ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo) != 0) |
| 6089 | return -1; |
| 6090 | } |
| 6091 | |
| 6092 | return len; |
| 6093 | } |
| 6094 | |
| 6095 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
| 6096 | so we notice when children change state; as the handler for the |
| 6097 | sigsuspend in my_waitpid. */ |
| 6098 | |
| 6099 | static void |
| 6100 | sigchld_handler (int signo) |
| 6101 | { |
| 6102 | int old_errno = errno; |
| 6103 | |
| 6104 | if (debug_threads) |
| 6105 | { |
| 6106 | do |
| 6107 | { |
| 6108 | /* Use the async signal safe debug function. */ |
| 6109 | if (debug_write ("sigchld_handler\n", |
| 6110 | sizeof ("sigchld_handler\n") - 1) < 0) |
| 6111 | break; /* just ignore */ |
| 6112 | } while (0); |
| 6113 | } |
| 6114 | |
| 6115 | if (target_is_async_p ()) |
| 6116 | async_file_mark (); /* trigger a linux_wait */ |
| 6117 | |
| 6118 | errno = old_errno; |
| 6119 | } |
| 6120 | |
| 6121 | bool |
| 6122 | linux_process_target::supports_non_stop () |
| 6123 | { |
| 6124 | return true; |
| 6125 | } |
| 6126 | |
| 6127 | bool |
| 6128 | linux_process_target::async (bool enable) |
| 6129 | { |
| 6130 | bool previous = target_is_async_p (); |
| 6131 | |
| 6132 | if (debug_threads) |
| 6133 | debug_printf ("linux_async (%d), previous=%d\n", |
| 6134 | enable, previous); |
| 6135 | |
| 6136 | if (previous != enable) |
| 6137 | { |
| 6138 | sigset_t mask; |
| 6139 | sigemptyset (&mask); |
| 6140 | sigaddset (&mask, SIGCHLD); |
| 6141 | |
| 6142 | gdb_sigmask (SIG_BLOCK, &mask, NULL); |
| 6143 | |
| 6144 | if (enable) |
| 6145 | { |
| 6146 | if (pipe (linux_event_pipe) == -1) |
| 6147 | { |
| 6148 | linux_event_pipe[0] = -1; |
| 6149 | linux_event_pipe[1] = -1; |
| 6150 | gdb_sigmask (SIG_UNBLOCK, &mask, NULL); |
| 6151 | |
| 6152 | warning ("creating event pipe failed."); |
| 6153 | return previous; |
| 6154 | } |
| 6155 | |
| 6156 | fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK); |
| 6157 | fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK); |
| 6158 | |
| 6159 | /* Register the event loop handler. */ |
| 6160 | add_file_handler (linux_event_pipe[0], |
| 6161 | handle_target_event, NULL); |
| 6162 | |
| 6163 | /* Always trigger a linux_wait. */ |
| 6164 | async_file_mark (); |
| 6165 | } |
| 6166 | else |
| 6167 | { |
| 6168 | delete_file_handler (linux_event_pipe[0]); |
| 6169 | |
| 6170 | close (linux_event_pipe[0]); |
| 6171 | close (linux_event_pipe[1]); |
| 6172 | linux_event_pipe[0] = -1; |
| 6173 | linux_event_pipe[1] = -1; |
| 6174 | } |
| 6175 | |
| 6176 | gdb_sigmask (SIG_UNBLOCK, &mask, NULL); |
| 6177 | } |
| 6178 | |
| 6179 | return previous; |
| 6180 | } |
| 6181 | |
| 6182 | int |
| 6183 | linux_process_target::start_non_stop (bool nonstop) |
| 6184 | { |
| 6185 | /* Register or unregister from event-loop accordingly. */ |
| 6186 | target_async (nonstop); |
| 6187 | |
| 6188 | if (target_is_async_p () != (nonstop != false)) |
| 6189 | return -1; |
| 6190 | |
| 6191 | return 0; |
| 6192 | } |
| 6193 | |
| 6194 | bool |
| 6195 | linux_process_target::supports_multi_process () |
| 6196 | { |
| 6197 | return true; |
| 6198 | } |
| 6199 | |
| 6200 | /* Check if fork events are supported. */ |
| 6201 | |
| 6202 | bool |
| 6203 | linux_process_target::supports_fork_events () |
| 6204 | { |
| 6205 | return linux_supports_tracefork (); |
| 6206 | } |
| 6207 | |
| 6208 | /* Check if vfork events are supported. */ |
| 6209 | |
| 6210 | bool |
| 6211 | linux_process_target::supports_vfork_events () |
| 6212 | { |
| 6213 | return linux_supports_tracefork (); |
| 6214 | } |
| 6215 | |
| 6216 | /* Check if exec events are supported. */ |
| 6217 | |
| 6218 | bool |
| 6219 | linux_process_target::supports_exec_events () |
| 6220 | { |
| 6221 | return linux_supports_traceexec (); |
| 6222 | } |
| 6223 | |
| 6224 | /* Target hook for 'handle_new_gdb_connection'. Causes a reset of the |
| 6225 | ptrace flags for all inferiors. This is in case the new GDB connection |
| 6226 | doesn't support the same set of events that the previous one did. */ |
| 6227 | |
| 6228 | void |
| 6229 | linux_process_target::handle_new_gdb_connection () |
| 6230 | { |
| 6231 | /* Request that all the lwps reset their ptrace options. */ |
| 6232 | for_each_thread ([] (thread_info *thread) |
| 6233 | { |
| 6234 | struct lwp_info *lwp = get_thread_lwp (thread); |
| 6235 | |
| 6236 | if (!lwp->stopped) |
| 6237 | { |
| 6238 | /* Stop the lwp so we can modify its ptrace options. */ |
| 6239 | lwp->must_set_ptrace_flags = 1; |
| 6240 | linux_stop_lwp (lwp); |
| 6241 | } |
| 6242 | else |
| 6243 | { |
| 6244 | /* Already stopped; go ahead and set the ptrace options. */ |
| 6245 | struct process_info *proc = find_process_pid (pid_of (thread)); |
| 6246 | int options = linux_low_ptrace_options (proc->attached); |
| 6247 | |
| 6248 | linux_enable_event_reporting (lwpid_of (thread), options); |
| 6249 | lwp->must_set_ptrace_flags = 0; |
| 6250 | } |
| 6251 | }); |
| 6252 | } |
| 6253 | |
| 6254 | int |
| 6255 | linux_process_target::handle_monitor_command (char *mon) |
| 6256 | { |
| 6257 | #ifdef USE_THREAD_DB |
| 6258 | return thread_db_handle_monitor_command (mon); |
| 6259 | #else |
| 6260 | return 0; |
| 6261 | #endif |
| 6262 | } |
| 6263 | |
| 6264 | int |
| 6265 | linux_process_target::core_of_thread (ptid_t ptid) |
| 6266 | { |
| 6267 | return linux_common_core_of_thread (ptid); |
| 6268 | } |
| 6269 | |
| 6270 | bool |
| 6271 | linux_process_target::supports_disable_randomization () |
| 6272 | { |
| 6273 | #ifdef HAVE_PERSONALITY |
| 6274 | return true; |
| 6275 | #else |
| 6276 | return false; |
| 6277 | #endif |
| 6278 | } |
| 6279 | |
| 6280 | bool |
| 6281 | linux_process_target::supports_agent () |
| 6282 | { |
| 6283 | return true; |
| 6284 | } |
| 6285 | |
| 6286 | bool |
| 6287 | linux_process_target::supports_range_stepping () |
| 6288 | { |
| 6289 | if (supports_software_single_step ()) |
| 6290 | return true; |
| 6291 | if (*the_low_target.supports_range_stepping == NULL) |
| 6292 | return false; |
| 6293 | |
| 6294 | return (*the_low_target.supports_range_stepping) (); |
| 6295 | } |
| 6296 | |
| 6297 | bool |
| 6298 | linux_process_target::supports_pid_to_exec_file () |
| 6299 | { |
| 6300 | return true; |
| 6301 | } |
| 6302 | |
| 6303 | char * |
| 6304 | linux_process_target::pid_to_exec_file (int pid) |
| 6305 | { |
| 6306 | return linux_proc_pid_to_exec_file (pid); |
| 6307 | } |
| 6308 | |
| 6309 | bool |
| 6310 | linux_process_target::supports_multifs () |
| 6311 | { |
| 6312 | return true; |
| 6313 | } |
| 6314 | |
| 6315 | int |
| 6316 | linux_process_target::multifs_open (int pid, const char *filename, |
| 6317 | int flags, mode_t mode) |
| 6318 | { |
| 6319 | return linux_mntns_open_cloexec (pid, filename, flags, mode); |
| 6320 | } |
| 6321 | |
| 6322 | int |
| 6323 | linux_process_target::multifs_unlink (int pid, const char *filename) |
| 6324 | { |
| 6325 | return linux_mntns_unlink (pid, filename); |
| 6326 | } |
| 6327 | |
| 6328 | ssize_t |
| 6329 | linux_process_target::multifs_readlink (int pid, const char *filename, |
| 6330 | char *buf, size_t bufsiz) |
| 6331 | { |
| 6332 | return linux_mntns_readlink (pid, filename, buf, bufsiz); |
| 6333 | } |
| 6334 | |
| 6335 | #if defined PT_GETDSBT || defined PTRACE_GETFDPIC |
| 6336 | struct target_loadseg |
| 6337 | { |
| 6338 | /* Core address to which the segment is mapped. */ |
| 6339 | Elf32_Addr addr; |
| 6340 | /* VMA recorded in the program header. */ |
| 6341 | Elf32_Addr p_vaddr; |
| 6342 | /* Size of this segment in memory. */ |
| 6343 | Elf32_Word p_memsz; |
| 6344 | }; |
| 6345 | |
| 6346 | # if defined PT_GETDSBT |
| 6347 | struct target_loadmap |
| 6348 | { |
| 6349 | /* Protocol version number, must be zero. */ |
| 6350 | Elf32_Word version; |
| 6351 | /* Pointer to the DSBT table, its size, and the DSBT index. */ |
| 6352 | unsigned *dsbt_table; |
| 6353 | unsigned dsbt_size, dsbt_index; |
| 6354 | /* Number of segments in this map. */ |
| 6355 | Elf32_Word nsegs; |
| 6356 | /* The actual memory map. */ |
| 6357 | struct target_loadseg segs[/*nsegs*/]; |
| 6358 | }; |
| 6359 | # define LINUX_LOADMAP PT_GETDSBT |
| 6360 | # define LINUX_LOADMAP_EXEC PTRACE_GETDSBT_EXEC |
| 6361 | # define LINUX_LOADMAP_INTERP PTRACE_GETDSBT_INTERP |
| 6362 | # else |
| 6363 | struct target_loadmap |
| 6364 | { |
| 6365 | /* Protocol version number, must be zero. */ |
| 6366 | Elf32_Half version; |
| 6367 | /* Number of segments in this map. */ |
| 6368 | Elf32_Half nsegs; |
| 6369 | /* The actual memory map. */ |
| 6370 | struct target_loadseg segs[/*nsegs*/]; |
| 6371 | }; |
| 6372 | # define LINUX_LOADMAP PTRACE_GETFDPIC |
| 6373 | # define LINUX_LOADMAP_EXEC PTRACE_GETFDPIC_EXEC |
| 6374 | # define LINUX_LOADMAP_INTERP PTRACE_GETFDPIC_INTERP |
| 6375 | # endif |
| 6376 | |
| 6377 | bool |
| 6378 | linux_process_target::supports_read_loadmap () |
| 6379 | { |
| 6380 | return true; |
| 6381 | } |
| 6382 | |
| 6383 | int |
| 6384 | linux_process_target::read_loadmap (const char *annex, CORE_ADDR offset, |
| 6385 | unsigned char *myaddr, unsigned int len) |
| 6386 | { |
| 6387 | int pid = lwpid_of (current_thread); |
| 6388 | int addr = -1; |
| 6389 | struct target_loadmap *data = NULL; |
| 6390 | unsigned int actual_length, copy_length; |
| 6391 | |
| 6392 | if (strcmp (annex, "exec") == 0) |
| 6393 | addr = (int) LINUX_LOADMAP_EXEC; |
| 6394 | else if (strcmp (annex, "interp") == 0) |
| 6395 | addr = (int) LINUX_LOADMAP_INTERP; |
| 6396 | else |
| 6397 | return -1; |
| 6398 | |
| 6399 | if (ptrace (LINUX_LOADMAP, pid, addr, &data) != 0) |
| 6400 | return -1; |
| 6401 | |
| 6402 | if (data == NULL) |
| 6403 | return -1; |
| 6404 | |
| 6405 | actual_length = sizeof (struct target_loadmap) |
| 6406 | + sizeof (struct target_loadseg) * data->nsegs; |
| 6407 | |
| 6408 | if (offset < 0 || offset > actual_length) |
| 6409 | return -1; |
| 6410 | |
| 6411 | copy_length = actual_length - offset < len ? actual_length - offset : len; |
| 6412 | memcpy (myaddr, (char *) data + offset, copy_length); |
| 6413 | return copy_length; |
| 6414 | } |
| 6415 | #endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */ |
| 6416 | |
| 6417 | void |
| 6418 | linux_process_target::process_qsupported (char **features, int count) |
| 6419 | { |
| 6420 | if (the_low_target.process_qsupported != NULL) |
| 6421 | the_low_target.process_qsupported (features, count); |
| 6422 | } |
| 6423 | |
| 6424 | bool |
| 6425 | linux_process_target::supports_catch_syscall () |
| 6426 | { |
| 6427 | return (the_low_target.get_syscall_trapinfo != NULL |
| 6428 | && linux_supports_tracesysgood ()); |
| 6429 | } |
| 6430 | |
| 6431 | int |
| 6432 | linux_process_target::get_ipa_tdesc_idx () |
| 6433 | { |
| 6434 | if (the_low_target.get_ipa_tdesc_idx == NULL) |
| 6435 | return 0; |
| 6436 | |
| 6437 | return (*the_low_target.get_ipa_tdesc_idx) (); |
| 6438 | } |
| 6439 | |
| 6440 | bool |
| 6441 | linux_process_target::supports_tracepoints () |
| 6442 | { |
| 6443 | if (*the_low_target.supports_tracepoints == NULL) |
| 6444 | return false; |
| 6445 | |
| 6446 | return (*the_low_target.supports_tracepoints) (); |
| 6447 | } |
| 6448 | |
| 6449 | CORE_ADDR |
| 6450 | linux_process_target::read_pc (regcache *regcache) |
| 6451 | { |
| 6452 | if (!low_supports_breakpoints ()) |
| 6453 | return 0; |
| 6454 | |
| 6455 | return low_get_pc (regcache); |
| 6456 | } |
| 6457 | |
| 6458 | void |
| 6459 | linux_process_target::write_pc (regcache *regcache, CORE_ADDR pc) |
| 6460 | { |
| 6461 | gdb_assert (low_supports_breakpoints ()); |
| 6462 | |
| 6463 | low_set_pc (regcache, pc); |
| 6464 | } |
| 6465 | |
| 6466 | bool |
| 6467 | linux_process_target::supports_thread_stopped () |
| 6468 | { |
| 6469 | return true; |
| 6470 | } |
| 6471 | |
| 6472 | bool |
| 6473 | linux_process_target::thread_stopped (thread_info *thread) |
| 6474 | { |
| 6475 | return get_thread_lwp (thread)->stopped; |
| 6476 | } |
| 6477 | |
| 6478 | /* This exposes stop-all-threads functionality to other modules. */ |
| 6479 | |
| 6480 | void |
| 6481 | linux_process_target::pause_all (bool freeze) |
| 6482 | { |
| 6483 | stop_all_lwps (freeze, NULL); |
| 6484 | } |
| 6485 | |
| 6486 | /* This exposes unstop-all-threads functionality to other gdbserver |
| 6487 | modules. */ |
| 6488 | |
| 6489 | void |
| 6490 | linux_process_target::unpause_all (bool unfreeze) |
| 6491 | { |
| 6492 | unstop_all_lwps (unfreeze, NULL); |
| 6493 | } |
| 6494 | |
| 6495 | int |
| 6496 | linux_process_target::prepare_to_access_memory () |
| 6497 | { |
| 6498 | /* Neither ptrace nor /proc/PID/mem allow accessing memory through a |
| 6499 | running LWP. */ |
| 6500 | if (non_stop) |
| 6501 | target_pause_all (true); |
| 6502 | return 0; |
| 6503 | } |
| 6504 | |
| 6505 | void |
| 6506 | linux_process_target::done_accessing_memory () |
| 6507 | { |
| 6508 | /* Neither ptrace nor /proc/PID/mem allow accessing memory through a |
| 6509 | running LWP. */ |
| 6510 | if (non_stop) |
| 6511 | target_unpause_all (true); |
| 6512 | } |
| 6513 | |
| 6514 | bool |
| 6515 | linux_process_target::supports_fast_tracepoints () |
| 6516 | { |
| 6517 | return the_low_target.install_fast_tracepoint_jump_pad != nullptr; |
| 6518 | } |
| 6519 | |
| 6520 | int |
| 6521 | linux_process_target::install_fast_tracepoint_jump_pad |
| 6522 | (CORE_ADDR tpoint, CORE_ADDR tpaddr, CORE_ADDR collector, |
| 6523 | CORE_ADDR lockaddr, ULONGEST orig_size, CORE_ADDR *jump_entry, |
| 6524 | CORE_ADDR *trampoline, ULONGEST *trampoline_size, |
| 6525 | unsigned char *jjump_pad_insn, ULONGEST *jjump_pad_insn_size, |
| 6526 | CORE_ADDR *adjusted_insn_addr, CORE_ADDR *adjusted_insn_addr_end, |
| 6527 | char *err) |
| 6528 | { |
| 6529 | return (*the_low_target.install_fast_tracepoint_jump_pad) |
| 6530 | (tpoint, tpaddr, collector, lockaddr, orig_size, |
| 6531 | jump_entry, trampoline, trampoline_size, |
| 6532 | jjump_pad_insn, jjump_pad_insn_size, |
| 6533 | adjusted_insn_addr, adjusted_insn_addr_end, |
| 6534 | err); |
| 6535 | } |
| 6536 | |
| 6537 | emit_ops * |
| 6538 | linux_process_target::emit_ops () |
| 6539 | { |
| 6540 | if (the_low_target.emit_ops != NULL) |
| 6541 | return (*the_low_target.emit_ops) (); |
| 6542 | else |
| 6543 | return NULL; |
| 6544 | } |
| 6545 | |
| 6546 | int |
| 6547 | linux_process_target::get_min_fast_tracepoint_insn_len () |
| 6548 | { |
| 6549 | return (*the_low_target.get_min_fast_tracepoint_insn_len) (); |
| 6550 | } |
| 6551 | |
| 6552 | /* Extract &phdr and num_phdr in the inferior. Return 0 on success. */ |
| 6553 | |
| 6554 | static int |
| 6555 | get_phdr_phnum_from_proc_auxv (const int pid, const int is_elf64, |
| 6556 | CORE_ADDR *phdr_memaddr, int *num_phdr) |
| 6557 | { |
| 6558 | char filename[PATH_MAX]; |
| 6559 | int fd; |
| 6560 | const int auxv_size = is_elf64 |
| 6561 | ? sizeof (Elf64_auxv_t) : sizeof (Elf32_auxv_t); |
| 6562 | char buf[sizeof (Elf64_auxv_t)]; /* The larger of the two. */ |
| 6563 | |
| 6564 | xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid); |
| 6565 | |
| 6566 | fd = open (filename, O_RDONLY); |
| 6567 | if (fd < 0) |
| 6568 | return 1; |
| 6569 | |
| 6570 | *phdr_memaddr = 0; |
| 6571 | *num_phdr = 0; |
| 6572 | while (read (fd, buf, auxv_size) == auxv_size |
| 6573 | && (*phdr_memaddr == 0 || *num_phdr == 0)) |
| 6574 | { |
| 6575 | if (is_elf64) |
| 6576 | { |
| 6577 | Elf64_auxv_t *const aux = (Elf64_auxv_t *) buf; |
| 6578 | |
| 6579 | switch (aux->a_type) |
| 6580 | { |
| 6581 | case AT_PHDR: |
| 6582 | *phdr_memaddr = aux->a_un.a_val; |
| 6583 | break; |
| 6584 | case AT_PHNUM: |
| 6585 | *num_phdr = aux->a_un.a_val; |
| 6586 | break; |
| 6587 | } |
| 6588 | } |
| 6589 | else |
| 6590 | { |
| 6591 | Elf32_auxv_t *const aux = (Elf32_auxv_t *) buf; |
| 6592 | |
| 6593 | switch (aux->a_type) |
| 6594 | { |
| 6595 | case AT_PHDR: |
| 6596 | *phdr_memaddr = aux->a_un.a_val; |
| 6597 | break; |
| 6598 | case AT_PHNUM: |
| 6599 | *num_phdr = aux->a_un.a_val; |
| 6600 | break; |
| 6601 | } |
| 6602 | } |
| 6603 | } |
| 6604 | |
| 6605 | close (fd); |
| 6606 | |
| 6607 | if (*phdr_memaddr == 0 || *num_phdr == 0) |
| 6608 | { |
| 6609 | warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: " |
| 6610 | "phdr_memaddr = %ld, phdr_num = %d", |
| 6611 | (long) *phdr_memaddr, *num_phdr); |
| 6612 | return 2; |
| 6613 | } |
| 6614 | |
| 6615 | return 0; |
| 6616 | } |
| 6617 | |
| 6618 | /* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */ |
| 6619 | |
| 6620 | static CORE_ADDR |
| 6621 | get_dynamic (const int pid, const int is_elf64) |
| 6622 | { |
| 6623 | CORE_ADDR phdr_memaddr, relocation; |
| 6624 | int num_phdr, i; |
| 6625 | unsigned char *phdr_buf; |
| 6626 | const int phdr_size = is_elf64 ? sizeof (Elf64_Phdr) : sizeof (Elf32_Phdr); |
| 6627 | |
| 6628 | if (get_phdr_phnum_from_proc_auxv (pid, is_elf64, &phdr_memaddr, &num_phdr)) |
| 6629 | return 0; |
| 6630 | |
| 6631 | gdb_assert (num_phdr < 100); /* Basic sanity check. */ |
| 6632 | phdr_buf = (unsigned char *) alloca (num_phdr * phdr_size); |
| 6633 | |
| 6634 | if (linux_read_memory (phdr_memaddr, phdr_buf, num_phdr * phdr_size)) |
| 6635 | return 0; |
| 6636 | |
| 6637 | /* Compute relocation: it is expected to be 0 for "regular" executables, |
| 6638 | non-zero for PIE ones. */ |
| 6639 | relocation = -1; |
| 6640 | for (i = 0; relocation == -1 && i < num_phdr; i++) |
| 6641 | if (is_elf64) |
| 6642 | { |
| 6643 | Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size); |
| 6644 | |
| 6645 | if (p->p_type == PT_PHDR) |
| 6646 | relocation = phdr_memaddr - p->p_vaddr; |
| 6647 | } |
| 6648 | else |
| 6649 | { |
| 6650 | Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size); |
| 6651 | |
| 6652 | if (p->p_type == PT_PHDR) |
| 6653 | relocation = phdr_memaddr - p->p_vaddr; |
| 6654 | } |
| 6655 | |
| 6656 | if (relocation == -1) |
| 6657 | { |
| 6658 | /* PT_PHDR is optional, but necessary for PIE in general. Fortunately |
| 6659 | any real world executables, including PIE executables, have always |
| 6660 | PT_PHDR present. PT_PHDR is not present in some shared libraries or |
| 6661 | in fpc (Free Pascal 2.4) binaries but neither of those have a need for |
| 6662 | or present DT_DEBUG anyway (fpc binaries are statically linked). |
| 6663 | |
| 6664 | Therefore if there exists DT_DEBUG there is always also PT_PHDR. |
| 6665 | |
| 6666 | GDB could find RELOCATION also from AT_ENTRY - e_entry. */ |
| 6667 | |
| 6668 | return 0; |
| 6669 | } |
| 6670 | |
| 6671 | for (i = 0; i < num_phdr; i++) |
| 6672 | { |
| 6673 | if (is_elf64) |
| 6674 | { |
| 6675 | Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size); |
| 6676 | |
| 6677 | if (p->p_type == PT_DYNAMIC) |
| 6678 | return p->p_vaddr + relocation; |
| 6679 | } |
| 6680 | else |
| 6681 | { |
| 6682 | Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size); |
| 6683 | |
| 6684 | if (p->p_type == PT_DYNAMIC) |
| 6685 | return p->p_vaddr + relocation; |
| 6686 | } |
| 6687 | } |
| 6688 | |
| 6689 | return 0; |
| 6690 | } |
| 6691 | |
| 6692 | /* Return &_r_debug in the inferior, or -1 if not present. Return value |
| 6693 | can be 0 if the inferior does not yet have the library list initialized. |
| 6694 | We look for DT_MIPS_RLD_MAP first. MIPS executables use this instead of |
| 6695 | DT_DEBUG, although they sometimes contain an unused DT_DEBUG entry too. */ |
| 6696 | |
| 6697 | static CORE_ADDR |
| 6698 | get_r_debug (const int pid, const int is_elf64) |
| 6699 | { |
| 6700 | CORE_ADDR dynamic_memaddr; |
| 6701 | const int dyn_size = is_elf64 ? sizeof (Elf64_Dyn) : sizeof (Elf32_Dyn); |
| 6702 | unsigned char buf[sizeof (Elf64_Dyn)]; /* The larger of the two. */ |
| 6703 | CORE_ADDR map = -1; |
| 6704 | |
| 6705 | dynamic_memaddr = get_dynamic (pid, is_elf64); |
| 6706 | if (dynamic_memaddr == 0) |
| 6707 | return map; |
| 6708 | |
| 6709 | while (linux_read_memory (dynamic_memaddr, buf, dyn_size) == 0) |
| 6710 | { |
| 6711 | if (is_elf64) |
| 6712 | { |
| 6713 | Elf64_Dyn *const dyn = (Elf64_Dyn *) buf; |
| 6714 | #if defined DT_MIPS_RLD_MAP || defined DT_MIPS_RLD_MAP_REL |
| 6715 | union |
| 6716 | { |
| 6717 | Elf64_Xword map; |
| 6718 | unsigned char buf[sizeof (Elf64_Xword)]; |
| 6719 | } |
| 6720 | rld_map; |
| 6721 | #endif |
| 6722 | #ifdef DT_MIPS_RLD_MAP |
| 6723 | if (dyn->d_tag == DT_MIPS_RLD_MAP) |
| 6724 | { |
| 6725 | if (linux_read_memory (dyn->d_un.d_val, |
| 6726 | rld_map.buf, sizeof (rld_map.buf)) == 0) |
| 6727 | return rld_map.map; |
| 6728 | else |
| 6729 | break; |
| 6730 | } |
| 6731 | #endif /* DT_MIPS_RLD_MAP */ |
| 6732 | #ifdef DT_MIPS_RLD_MAP_REL |
| 6733 | if (dyn->d_tag == DT_MIPS_RLD_MAP_REL) |
| 6734 | { |
| 6735 | if (linux_read_memory (dyn->d_un.d_val + dynamic_memaddr, |
| 6736 | rld_map.buf, sizeof (rld_map.buf)) == 0) |
| 6737 | return rld_map.map; |
| 6738 | else |
| 6739 | break; |
| 6740 | } |
| 6741 | #endif /* DT_MIPS_RLD_MAP_REL */ |
| 6742 | |
| 6743 | if (dyn->d_tag == DT_DEBUG && map == -1) |
| 6744 | map = dyn->d_un.d_val; |
| 6745 | |
| 6746 | if (dyn->d_tag == DT_NULL) |
| 6747 | break; |
| 6748 | } |
| 6749 | else |
| 6750 | { |
| 6751 | Elf32_Dyn *const dyn = (Elf32_Dyn *) buf; |
| 6752 | #if defined DT_MIPS_RLD_MAP || defined DT_MIPS_RLD_MAP_REL |
| 6753 | union |
| 6754 | { |
| 6755 | Elf32_Word map; |
| 6756 | unsigned char buf[sizeof (Elf32_Word)]; |
| 6757 | } |
| 6758 | rld_map; |
| 6759 | #endif |
| 6760 | #ifdef DT_MIPS_RLD_MAP |
| 6761 | if (dyn->d_tag == DT_MIPS_RLD_MAP) |
| 6762 | { |
| 6763 | if (linux_read_memory (dyn->d_un.d_val, |
| 6764 | rld_map.buf, sizeof (rld_map.buf)) == 0) |
| 6765 | return rld_map.map; |
| 6766 | else |
| 6767 | break; |
| 6768 | } |
| 6769 | #endif /* DT_MIPS_RLD_MAP */ |
| 6770 | #ifdef DT_MIPS_RLD_MAP_REL |
| 6771 | if (dyn->d_tag == DT_MIPS_RLD_MAP_REL) |
| 6772 | { |
| 6773 | if (linux_read_memory (dyn->d_un.d_val + dynamic_memaddr, |
| 6774 | rld_map.buf, sizeof (rld_map.buf)) == 0) |
| 6775 | return rld_map.map; |
| 6776 | else |
| 6777 | break; |
| 6778 | } |
| 6779 | #endif /* DT_MIPS_RLD_MAP_REL */ |
| 6780 | |
| 6781 | if (dyn->d_tag == DT_DEBUG && map == -1) |
| 6782 | map = dyn->d_un.d_val; |
| 6783 | |
| 6784 | if (dyn->d_tag == DT_NULL) |
| 6785 | break; |
| 6786 | } |
| 6787 | |
| 6788 | dynamic_memaddr += dyn_size; |
| 6789 | } |
| 6790 | |
| 6791 | return map; |
| 6792 | } |
| 6793 | |
| 6794 | /* Read one pointer from MEMADDR in the inferior. */ |
| 6795 | |
| 6796 | static int |
| 6797 | read_one_ptr (CORE_ADDR memaddr, CORE_ADDR *ptr, int ptr_size) |
| 6798 | { |
| 6799 | int ret; |
| 6800 | |
| 6801 | /* Go through a union so this works on either big or little endian |
| 6802 | hosts, when the inferior's pointer size is smaller than the size |
| 6803 | of CORE_ADDR. It is assumed the inferior's endianness is the |
| 6804 | same of the superior's. */ |
| 6805 | union |
| 6806 | { |
| 6807 | CORE_ADDR core_addr; |
| 6808 | unsigned int ui; |
| 6809 | unsigned char uc; |
| 6810 | } addr; |
| 6811 | |
| 6812 | ret = linux_read_memory (memaddr, &addr.uc, ptr_size); |
| 6813 | if (ret == 0) |
| 6814 | { |
| 6815 | if (ptr_size == sizeof (CORE_ADDR)) |
| 6816 | *ptr = addr.core_addr; |
| 6817 | else if (ptr_size == sizeof (unsigned int)) |
| 6818 | *ptr = addr.ui; |
| 6819 | else |
| 6820 | gdb_assert_not_reached ("unhandled pointer size"); |
| 6821 | } |
| 6822 | return ret; |
| 6823 | } |
| 6824 | |
| 6825 | bool |
| 6826 | linux_process_target::supports_qxfer_libraries_svr4 () |
| 6827 | { |
| 6828 | return true; |
| 6829 | } |
| 6830 | |
| 6831 | struct link_map_offsets |
| 6832 | { |
| 6833 | /* Offset and size of r_debug.r_version. */ |
| 6834 | int r_version_offset; |
| 6835 | |
| 6836 | /* Offset and size of r_debug.r_map. */ |
| 6837 | int r_map_offset; |
| 6838 | |
| 6839 | /* Offset to l_addr field in struct link_map. */ |
| 6840 | int l_addr_offset; |
| 6841 | |
| 6842 | /* Offset to l_name field in struct link_map. */ |
| 6843 | int l_name_offset; |
| 6844 | |
| 6845 | /* Offset to l_ld field in struct link_map. */ |
| 6846 | int l_ld_offset; |
| 6847 | |
| 6848 | /* Offset to l_next field in struct link_map. */ |
| 6849 | int l_next_offset; |
| 6850 | |
| 6851 | /* Offset to l_prev field in struct link_map. */ |
| 6852 | int l_prev_offset; |
| 6853 | }; |
| 6854 | |
| 6855 | /* Construct qXfer:libraries-svr4:read reply. */ |
| 6856 | |
| 6857 | int |
| 6858 | linux_process_target::qxfer_libraries_svr4 (const char *annex, |
| 6859 | unsigned char *readbuf, |
| 6860 | unsigned const char *writebuf, |
| 6861 | CORE_ADDR offset, int len) |
| 6862 | { |
| 6863 | struct process_info_private *const priv = current_process ()->priv; |
| 6864 | char filename[PATH_MAX]; |
| 6865 | int pid, is_elf64; |
| 6866 | |
| 6867 | static const struct link_map_offsets lmo_32bit_offsets = |
| 6868 | { |
| 6869 | 0, /* r_version offset. */ |
| 6870 | 4, /* r_debug.r_map offset. */ |
| 6871 | 0, /* l_addr offset in link_map. */ |
| 6872 | 4, /* l_name offset in link_map. */ |
| 6873 | 8, /* l_ld offset in link_map. */ |
| 6874 | 12, /* l_next offset in link_map. */ |
| 6875 | 16 /* l_prev offset in link_map. */ |
| 6876 | }; |
| 6877 | |
| 6878 | static const struct link_map_offsets lmo_64bit_offsets = |
| 6879 | { |
| 6880 | 0, /* r_version offset. */ |
| 6881 | 8, /* r_debug.r_map offset. */ |
| 6882 | 0, /* l_addr offset in link_map. */ |
| 6883 | 8, /* l_name offset in link_map. */ |
| 6884 | 16, /* l_ld offset in link_map. */ |
| 6885 | 24, /* l_next offset in link_map. */ |
| 6886 | 32 /* l_prev offset in link_map. */ |
| 6887 | }; |
| 6888 | const struct link_map_offsets *lmo; |
| 6889 | unsigned int machine; |
| 6890 | int ptr_size; |
| 6891 | CORE_ADDR lm_addr = 0, lm_prev = 0; |
| 6892 | CORE_ADDR l_name, l_addr, l_ld, l_next, l_prev; |
| 6893 | int header_done = 0; |
| 6894 | |
| 6895 | if (writebuf != NULL) |
| 6896 | return -2; |
| 6897 | if (readbuf == NULL) |
| 6898 | return -1; |
| 6899 | |
| 6900 | pid = lwpid_of (current_thread); |
| 6901 | xsnprintf (filename, sizeof filename, "/proc/%d/exe", pid); |
| 6902 | is_elf64 = elf_64_file_p (filename, &machine); |
| 6903 | lmo = is_elf64 ? &lmo_64bit_offsets : &lmo_32bit_offsets; |
| 6904 | ptr_size = is_elf64 ? 8 : 4; |
| 6905 | |
| 6906 | while (annex[0] != '\0') |
| 6907 | { |
| 6908 | const char *sep; |
| 6909 | CORE_ADDR *addrp; |
| 6910 | int name_len; |
| 6911 | |
| 6912 | sep = strchr (annex, '='); |
| 6913 | if (sep == NULL) |
| 6914 | break; |
| 6915 | |
| 6916 | name_len = sep - annex; |
| 6917 | if (name_len == 5 && startswith (annex, "start")) |
| 6918 | addrp = &lm_addr; |
| 6919 | else if (name_len == 4 && startswith (annex, "prev")) |
| 6920 | addrp = &lm_prev; |
| 6921 | else |
| 6922 | { |
| 6923 | annex = strchr (sep, ';'); |
| 6924 | if (annex == NULL) |
| 6925 | break; |
| 6926 | annex++; |
| 6927 | continue; |
| 6928 | } |
| 6929 | |
| 6930 | annex = decode_address_to_semicolon (addrp, sep + 1); |
| 6931 | } |
| 6932 | |
| 6933 | if (lm_addr == 0) |
| 6934 | { |
| 6935 | int r_version = 0; |
| 6936 | |
| 6937 | if (priv->r_debug == 0) |
| 6938 | priv->r_debug = get_r_debug (pid, is_elf64); |
| 6939 | |
| 6940 | /* We failed to find DT_DEBUG. Such situation will not change |
| 6941 | for this inferior - do not retry it. Report it to GDB as |
| 6942 | E01, see for the reasons at the GDB solib-svr4.c side. */ |
| 6943 | if (priv->r_debug == (CORE_ADDR) -1) |
| 6944 | return -1; |
| 6945 | |
| 6946 | if (priv->r_debug != 0) |
| 6947 | { |
| 6948 | if (linux_read_memory (priv->r_debug + lmo->r_version_offset, |
| 6949 | (unsigned char *) &r_version, |
| 6950 | sizeof (r_version)) != 0 |
| 6951 | || r_version != 1) |
| 6952 | { |
| 6953 | warning ("unexpected r_debug version %d", r_version); |
| 6954 | } |
| 6955 | else if (read_one_ptr (priv->r_debug + lmo->r_map_offset, |
| 6956 | &lm_addr, ptr_size) != 0) |
| 6957 | { |
| 6958 | warning ("unable to read r_map from 0x%lx", |
| 6959 | (long) priv->r_debug + lmo->r_map_offset); |
| 6960 | } |
| 6961 | } |
| 6962 | } |
| 6963 | |
| 6964 | std::string document = "<library-list-svr4 version=\"1.0\""; |
| 6965 | |
| 6966 | while (lm_addr |
| 6967 | && read_one_ptr (lm_addr + lmo->l_name_offset, |
| 6968 | &l_name, ptr_size) == 0 |
| 6969 | && read_one_ptr (lm_addr + lmo->l_addr_offset, |
| 6970 | &l_addr, ptr_size) == 0 |
| 6971 | && read_one_ptr (lm_addr + lmo->l_ld_offset, |
| 6972 | &l_ld, ptr_size) == 0 |
| 6973 | && read_one_ptr (lm_addr + lmo->l_prev_offset, |
| 6974 | &l_prev, ptr_size) == 0 |
| 6975 | && read_one_ptr (lm_addr + lmo->l_next_offset, |
| 6976 | &l_next, ptr_size) == 0) |
| 6977 | { |
| 6978 | unsigned char libname[PATH_MAX]; |
| 6979 | |
| 6980 | if (lm_prev != l_prev) |
| 6981 | { |
| 6982 | warning ("Corrupted shared library list: 0x%lx != 0x%lx", |
| 6983 | (long) lm_prev, (long) l_prev); |
| 6984 | break; |
| 6985 | } |
| 6986 | |
| 6987 | /* Ignore the first entry even if it has valid name as the first entry |
| 6988 | corresponds to the main executable. The first entry should not be |
| 6989 | skipped if the dynamic loader was loaded late by a static executable |
| 6990 | (see solib-svr4.c parameter ignore_first). But in such case the main |
| 6991 | executable does not have PT_DYNAMIC present and this function already |
| 6992 | exited above due to failed get_r_debug. */ |
| 6993 | if (lm_prev == 0) |
| 6994 | string_appendf (document, " main-lm=\"0x%lx\"", (unsigned long) lm_addr); |
| 6995 | else |
| 6996 | { |
| 6997 | /* Not checking for error because reading may stop before |
| 6998 | we've got PATH_MAX worth of characters. */ |
| 6999 | libname[0] = '\0'; |
| 7000 | linux_read_memory (l_name, libname, sizeof (libname) - 1); |
| 7001 | libname[sizeof (libname) - 1] = '\0'; |
| 7002 | if (libname[0] != '\0') |
| 7003 | { |
| 7004 | if (!header_done) |
| 7005 | { |
| 7006 | /* Terminate `<library-list-svr4'. */ |
| 7007 | document += '>'; |
| 7008 | header_done = 1; |
| 7009 | } |
| 7010 | |
| 7011 | string_appendf (document, "<library name=\""); |
| 7012 | xml_escape_text_append (&document, (char *) libname); |
| 7013 | string_appendf (document, "\" lm=\"0x%lx\" " |
| 7014 | "l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>", |
| 7015 | (unsigned long) lm_addr, (unsigned long) l_addr, |
| 7016 | (unsigned long) l_ld); |
| 7017 | } |
| 7018 | } |
| 7019 | |
| 7020 | lm_prev = lm_addr; |
| 7021 | lm_addr = l_next; |
| 7022 | } |
| 7023 | |
| 7024 | if (!header_done) |
| 7025 | { |
| 7026 | /* Empty list; terminate `<library-list-svr4'. */ |
| 7027 | document += "/>"; |
| 7028 | } |
| 7029 | else |
| 7030 | document += "</library-list-svr4>"; |
| 7031 | |
| 7032 | int document_len = document.length (); |
| 7033 | if (offset < document_len) |
| 7034 | document_len -= offset; |
| 7035 | else |
| 7036 | document_len = 0; |
| 7037 | if (len > document_len) |
| 7038 | len = document_len; |
| 7039 | |
| 7040 | memcpy (readbuf, document.data () + offset, len); |
| 7041 | |
| 7042 | return len; |
| 7043 | } |
| 7044 | |
| 7045 | #ifdef HAVE_LINUX_BTRACE |
| 7046 | |
| 7047 | btrace_target_info * |
| 7048 | linux_process_target::enable_btrace (ptid_t ptid, |
| 7049 | const btrace_config *conf) |
| 7050 | { |
| 7051 | return linux_enable_btrace (ptid, conf); |
| 7052 | } |
| 7053 | |
| 7054 | /* See to_disable_btrace target method. */ |
| 7055 | |
| 7056 | int |
| 7057 | linux_process_target::disable_btrace (btrace_target_info *tinfo) |
| 7058 | { |
| 7059 | enum btrace_error err; |
| 7060 | |
| 7061 | err = linux_disable_btrace (tinfo); |
| 7062 | return (err == BTRACE_ERR_NONE ? 0 : -1); |
| 7063 | } |
| 7064 | |
| 7065 | /* Encode an Intel Processor Trace configuration. */ |
| 7066 | |
| 7067 | static void |
| 7068 | linux_low_encode_pt_config (struct buffer *buffer, |
| 7069 | const struct btrace_data_pt_config *config) |
| 7070 | { |
| 7071 | buffer_grow_str (buffer, "<pt-config>\n"); |
| 7072 | |
| 7073 | switch (config->cpu.vendor) |
| 7074 | { |
| 7075 | case CV_INTEL: |
| 7076 | buffer_xml_printf (buffer, "<cpu vendor=\"GenuineIntel\" family=\"%u\" " |
| 7077 | "model=\"%u\" stepping=\"%u\"/>\n", |
| 7078 | config->cpu.family, config->cpu.model, |
| 7079 | config->cpu.stepping); |
| 7080 | break; |
| 7081 | |
| 7082 | default: |
| 7083 | break; |
| 7084 | } |
| 7085 | |
| 7086 | buffer_grow_str (buffer, "</pt-config>\n"); |
| 7087 | } |
| 7088 | |
| 7089 | /* Encode a raw buffer. */ |
| 7090 | |
| 7091 | static void |
| 7092 | linux_low_encode_raw (struct buffer *buffer, const gdb_byte *data, |
| 7093 | unsigned int size) |
| 7094 | { |
| 7095 | if (size == 0) |
| 7096 | return; |
| 7097 | |
| 7098 | /* We use hex encoding - see gdbsupport/rsp-low.h. */ |
| 7099 | buffer_grow_str (buffer, "<raw>\n"); |
| 7100 | |
| 7101 | while (size-- > 0) |
| 7102 | { |
| 7103 | char elem[2]; |
| 7104 | |
| 7105 | elem[0] = tohex ((*data >> 4) & 0xf); |
| 7106 | elem[1] = tohex (*data++ & 0xf); |
| 7107 | |
| 7108 | buffer_grow (buffer, elem, 2); |
| 7109 | } |
| 7110 | |
| 7111 | buffer_grow_str (buffer, "</raw>\n"); |
| 7112 | } |
| 7113 | |
| 7114 | /* See to_read_btrace target method. */ |
| 7115 | |
| 7116 | int |
| 7117 | linux_process_target::read_btrace (btrace_target_info *tinfo, |
| 7118 | buffer *buffer, |
| 7119 | enum btrace_read_type type) |
| 7120 | { |
| 7121 | struct btrace_data btrace; |
| 7122 | enum btrace_error err; |
| 7123 | |
| 7124 | err = linux_read_btrace (&btrace, tinfo, type); |
| 7125 | if (err != BTRACE_ERR_NONE) |
| 7126 | { |
| 7127 | if (err == BTRACE_ERR_OVERFLOW) |
| 7128 | buffer_grow_str0 (buffer, "E.Overflow."); |
| 7129 | else |
| 7130 | buffer_grow_str0 (buffer, "E.Generic Error."); |
| 7131 | |
| 7132 | return -1; |
| 7133 | } |
| 7134 | |
| 7135 | switch (btrace.format) |
| 7136 | { |
| 7137 | case BTRACE_FORMAT_NONE: |
| 7138 | buffer_grow_str0 (buffer, "E.No Trace."); |
| 7139 | return -1; |
| 7140 | |
| 7141 | case BTRACE_FORMAT_BTS: |
| 7142 | buffer_grow_str (buffer, "<!DOCTYPE btrace SYSTEM \"btrace.dtd\">\n"); |
| 7143 | buffer_grow_str (buffer, "<btrace version=\"1.0\">\n"); |
| 7144 | |
| 7145 | for (const btrace_block &block : *btrace.variant.bts.blocks) |
| 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 | int |
| 7177 | linux_process_target::read_btrace_conf (const btrace_target_info *tinfo, |
| 7178 | 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 | const char * |
| 7221 | linux_process_target::thread_name (ptid_t thread) |
| 7222 | { |
| 7223 | return linux_proc_tid_get_name (thread); |
| 7224 | } |
| 7225 | |
| 7226 | #if USE_THREAD_DB |
| 7227 | bool |
| 7228 | linux_process_target::thread_handle (ptid_t ptid, gdb_byte **handle, |
| 7229 | int *handle_len) |
| 7230 | { |
| 7231 | return thread_db_thread_handle (ptid, handle, handle_len); |
| 7232 | } |
| 7233 | #endif |
| 7234 | |
| 7235 | /* Default implementation of linux_target_ops method "set_pc" for |
| 7236 | 32-bit pc register which is literally named "pc". */ |
| 7237 | |
| 7238 | void |
| 7239 | linux_set_pc_32bit (struct regcache *regcache, CORE_ADDR pc) |
| 7240 | { |
| 7241 | uint32_t newpc = pc; |
| 7242 | |
| 7243 | supply_register_by_name (regcache, "pc", &newpc); |
| 7244 | } |
| 7245 | |
| 7246 | /* Default implementation of linux_target_ops method "get_pc" for |
| 7247 | 32-bit pc register which is literally named "pc". */ |
| 7248 | |
| 7249 | CORE_ADDR |
| 7250 | linux_get_pc_32bit (struct regcache *regcache) |
| 7251 | { |
| 7252 | uint32_t pc; |
| 7253 | |
| 7254 | collect_register_by_name (regcache, "pc", &pc); |
| 7255 | if (debug_threads) |
| 7256 | debug_printf ("stop pc is 0x%" PRIx32 "\n", pc); |
| 7257 | return pc; |
| 7258 | } |
| 7259 | |
| 7260 | /* Default implementation of linux_target_ops method "set_pc" for |
| 7261 | 64-bit pc register which is literally named "pc". */ |
| 7262 | |
| 7263 | void |
| 7264 | linux_set_pc_64bit (struct regcache *regcache, CORE_ADDR pc) |
| 7265 | { |
| 7266 | uint64_t newpc = pc; |
| 7267 | |
| 7268 | supply_register_by_name (regcache, "pc", &newpc); |
| 7269 | } |
| 7270 | |
| 7271 | /* Default implementation of linux_target_ops method "get_pc" for |
| 7272 | 64-bit pc register which is literally named "pc". */ |
| 7273 | |
| 7274 | CORE_ADDR |
| 7275 | linux_get_pc_64bit (struct regcache *regcache) |
| 7276 | { |
| 7277 | uint64_t pc; |
| 7278 | |
| 7279 | collect_register_by_name (regcache, "pc", &pc); |
| 7280 | if (debug_threads) |
| 7281 | debug_printf ("stop pc is 0x%" PRIx64 "\n", pc); |
| 7282 | return pc; |
| 7283 | } |
| 7284 | |
| 7285 | /* See linux-low.h. */ |
| 7286 | |
| 7287 | int |
| 7288 | linux_get_auxv (int wordsize, CORE_ADDR match, CORE_ADDR *valp) |
| 7289 | { |
| 7290 | gdb_byte *data = (gdb_byte *) alloca (2 * wordsize); |
| 7291 | int offset = 0; |
| 7292 | |
| 7293 | gdb_assert (wordsize == 4 || wordsize == 8); |
| 7294 | |
| 7295 | while (the_target->read_auxv (offset, data, 2 * wordsize) == 2 * wordsize) |
| 7296 | { |
| 7297 | if (wordsize == 4) |
| 7298 | { |
| 7299 | uint32_t *data_p = (uint32_t *) data; |
| 7300 | if (data_p[0] == match) |
| 7301 | { |
| 7302 | *valp = data_p[1]; |
| 7303 | return 1; |
| 7304 | } |
| 7305 | } |
| 7306 | else |
| 7307 | { |
| 7308 | uint64_t *data_p = (uint64_t *) data; |
| 7309 | if (data_p[0] == match) |
| 7310 | { |
| 7311 | *valp = data_p[1]; |
| 7312 | return 1; |
| 7313 | } |
| 7314 | } |
| 7315 | |
| 7316 | offset += 2 * wordsize; |
| 7317 | } |
| 7318 | |
| 7319 | return 0; |
| 7320 | } |
| 7321 | |
| 7322 | /* See linux-low.h. */ |
| 7323 | |
| 7324 | CORE_ADDR |
| 7325 | linux_get_hwcap (int wordsize) |
| 7326 | { |
| 7327 | CORE_ADDR hwcap = 0; |
| 7328 | linux_get_auxv (wordsize, AT_HWCAP, &hwcap); |
| 7329 | return hwcap; |
| 7330 | } |
| 7331 | |
| 7332 | /* See linux-low.h. */ |
| 7333 | |
| 7334 | CORE_ADDR |
| 7335 | linux_get_hwcap2 (int wordsize) |
| 7336 | { |
| 7337 | CORE_ADDR hwcap2 = 0; |
| 7338 | linux_get_auxv (wordsize, AT_HWCAP2, &hwcap2); |
| 7339 | return hwcap2; |
| 7340 | } |
| 7341 | |
| 7342 | #ifdef HAVE_LINUX_REGSETS |
| 7343 | void |
| 7344 | initialize_regsets_info (struct regsets_info *info) |
| 7345 | { |
| 7346 | for (info->num_regsets = 0; |
| 7347 | info->regsets[info->num_regsets].size >= 0; |
| 7348 | info->num_regsets++) |
| 7349 | ; |
| 7350 | } |
| 7351 | #endif |
| 7352 | |
| 7353 | void |
| 7354 | initialize_low (void) |
| 7355 | { |
| 7356 | struct sigaction sigchld_action; |
| 7357 | |
| 7358 | memset (&sigchld_action, 0, sizeof (sigchld_action)); |
| 7359 | set_target_ops (the_linux_target); |
| 7360 | |
| 7361 | linux_ptrace_init_warnings (); |
| 7362 | linux_proc_init_warnings (); |
| 7363 | |
| 7364 | sigchld_action.sa_handler = sigchld_handler; |
| 7365 | sigemptyset (&sigchld_action.sa_mask); |
| 7366 | sigchld_action.sa_flags = SA_RESTART; |
| 7367 | sigaction (SIGCHLD, &sigchld_action, NULL); |
| 7368 | |
| 7369 | initialize_low_arch (); |
| 7370 | |
| 7371 | linux_check_ptrace_features (); |
| 7372 | } |