| 1 | /* Low level interface to ptrace, for the remote server for GDB. |
| 2 | Copyright 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004 |
| 3 | Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 2 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 59 Temple Place - Suite 330, |
| 20 | Boston, MA 02111-1307, USA. */ |
| 21 | |
| 22 | #include "server.h" |
| 23 | #include "linux-low.h" |
| 24 | |
| 25 | #include <sys/wait.h> |
| 26 | #include <stdio.h> |
| 27 | #include <sys/param.h> |
| 28 | #include <sys/dir.h> |
| 29 | #include <sys/ptrace.h> |
| 30 | #include <sys/user.h> |
| 31 | #include <signal.h> |
| 32 | #include <sys/ioctl.h> |
| 33 | #include <fcntl.h> |
| 34 | #include <string.h> |
| 35 | #include <stdlib.h> |
| 36 | #include <unistd.h> |
| 37 | #include <errno.h> |
| 38 | |
| 39 | /* ``all_threads'' is keyed by the LWP ID - it should be the thread ID instead, |
| 40 | however. This requires changing the ID in place when we go from !using_threads |
| 41 | to using_threads, immediately. |
| 42 | |
| 43 | ``all_processes'' is keyed by the process ID - which on Linux is (presently) |
| 44 | the same as the LWP ID. */ |
| 45 | |
| 46 | struct inferior_list all_processes; |
| 47 | |
| 48 | /* FIXME this is a bit of a hack, and could be removed. */ |
| 49 | int stopping_threads; |
| 50 | |
| 51 | /* FIXME make into a target method? */ |
| 52 | int using_threads; |
| 53 | |
| 54 | static void linux_resume_one_process (struct inferior_list_entry *entry, |
| 55 | int step, int signal); |
| 56 | static void linux_resume (struct thread_resume *resume_info); |
| 57 | static void stop_all_processes (void); |
| 58 | static int linux_wait_for_event (struct thread_info *child); |
| 59 | |
| 60 | struct pending_signals |
| 61 | { |
| 62 | int signal; |
| 63 | struct pending_signals *prev; |
| 64 | }; |
| 65 | |
| 66 | #define PTRACE_ARG3_TYPE long |
| 67 | #define PTRACE_XFER_TYPE long |
| 68 | |
| 69 | #ifdef HAVE_LINUX_REGSETS |
| 70 | static int use_regsets_p = 1; |
| 71 | #endif |
| 72 | |
| 73 | int debug_threads = 0; |
| 74 | |
| 75 | #define pid_of(proc) ((proc)->head.id) |
| 76 | |
| 77 | /* FIXME: Delete eventually. */ |
| 78 | #define inferior_pid (pid_of (get_thread_process (current_inferior))) |
| 79 | |
| 80 | /* This function should only be called if the process got a SIGTRAP. |
| 81 | The SIGTRAP could mean several things. |
| 82 | |
| 83 | On i386, where decr_pc_after_break is non-zero: |
| 84 | If we were single-stepping this process using PTRACE_SINGLESTEP, |
| 85 | we will get only the one SIGTRAP (even if the instruction we |
| 86 | stepped over was a breakpoint). The value of $eip will be the |
| 87 | next instruction. |
| 88 | If we continue the process using PTRACE_CONT, we will get a |
| 89 | SIGTRAP when we hit a breakpoint. The value of $eip will be |
| 90 | the instruction after the breakpoint (i.e. needs to be |
| 91 | decremented). If we report the SIGTRAP to GDB, we must also |
| 92 | report the undecremented PC. If we cancel the SIGTRAP, we |
| 93 | must resume at the decremented PC. |
| 94 | |
| 95 | (Presumably, not yet tested) On a non-decr_pc_after_break machine |
| 96 | with hardware or kernel single-step: |
| 97 | If we single-step over a breakpoint instruction, our PC will |
| 98 | point at the following instruction. If we continue and hit a |
| 99 | breakpoint instruction, our PC will point at the breakpoint |
| 100 | instruction. */ |
| 101 | |
| 102 | static CORE_ADDR |
| 103 | get_stop_pc (void) |
| 104 | { |
| 105 | CORE_ADDR stop_pc = (*the_low_target.get_pc) (); |
| 106 | |
| 107 | if (get_thread_process (current_inferior)->stepping) |
| 108 | return stop_pc; |
| 109 | else |
| 110 | return stop_pc - the_low_target.decr_pc_after_break; |
| 111 | } |
| 112 | |
| 113 | static void * |
| 114 | add_process (int pid) |
| 115 | { |
| 116 | struct process_info *process; |
| 117 | |
| 118 | process = (struct process_info *) malloc (sizeof (*process)); |
| 119 | memset (process, 0, sizeof (*process)); |
| 120 | |
| 121 | process->head.id = pid; |
| 122 | |
| 123 | /* Default to tid == lwpid == pid. */ |
| 124 | process->tid = pid; |
| 125 | process->lwpid = pid; |
| 126 | |
| 127 | add_inferior_to_list (&all_processes, &process->head); |
| 128 | |
| 129 | return process; |
| 130 | } |
| 131 | |
| 132 | /* Start an inferior process and returns its pid. |
| 133 | ALLARGS is a vector of program-name and args. */ |
| 134 | |
| 135 | static int |
| 136 | linux_create_inferior (char *program, char **allargs) |
| 137 | { |
| 138 | void *new_process; |
| 139 | int pid; |
| 140 | |
| 141 | pid = fork (); |
| 142 | if (pid < 0) |
| 143 | perror_with_name ("fork"); |
| 144 | |
| 145 | if (pid == 0) |
| 146 | { |
| 147 | ptrace (PTRACE_TRACEME, 0, 0, 0); |
| 148 | |
| 149 | signal (__SIGRTMIN + 1, SIG_DFL); |
| 150 | |
| 151 | setpgid (0, 0); |
| 152 | |
| 153 | execv (program, allargs); |
| 154 | |
| 155 | fprintf (stderr, "Cannot exec %s: %s.\n", program, |
| 156 | strerror (errno)); |
| 157 | fflush (stderr); |
| 158 | _exit (0177); |
| 159 | } |
| 160 | |
| 161 | new_process = add_process (pid); |
| 162 | add_thread (pid, new_process); |
| 163 | |
| 164 | return pid; |
| 165 | } |
| 166 | |
| 167 | /* Attach to an inferior process. */ |
| 168 | |
| 169 | void |
| 170 | linux_attach_lwp (int pid, int tid) |
| 171 | { |
| 172 | struct process_info *new_process; |
| 173 | |
| 174 | if (ptrace (PTRACE_ATTACH, pid, 0, 0) != 0) |
| 175 | { |
| 176 | fprintf (stderr, "Cannot attach to process %d: %s (%d)\n", pid, |
| 177 | strerror (errno), errno); |
| 178 | fflush (stderr); |
| 179 | |
| 180 | /* If we fail to attach to an LWP, just return. */ |
| 181 | if (!using_threads) |
| 182 | _exit (0177); |
| 183 | return; |
| 184 | } |
| 185 | |
| 186 | new_process = (struct process_info *) add_process (pid); |
| 187 | add_thread (tid, new_process); |
| 188 | |
| 189 | /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH |
| 190 | brings it to a halt. We should ignore that SIGSTOP and resume the process |
| 191 | (unless this is the first process, in which case the flag will be cleared |
| 192 | in linux_attach). |
| 193 | |
| 194 | On the other hand, if we are currently trying to stop all threads, we |
| 195 | should treat the new thread as if we had sent it a SIGSTOP. This works |
| 196 | because we are guaranteed that add_process added us to the end of the |
| 197 | list, and so the new thread has not yet reached wait_for_sigstop (but |
| 198 | will). */ |
| 199 | if (! stopping_threads) |
| 200 | new_process->stop_expected = 1; |
| 201 | } |
| 202 | |
| 203 | int |
| 204 | linux_attach (int pid) |
| 205 | { |
| 206 | struct process_info *process; |
| 207 | |
| 208 | linux_attach_lwp (pid, pid); |
| 209 | |
| 210 | /* Don't ignore the initial SIGSTOP if we just attached to this process. */ |
| 211 | process = (struct process_info *) find_inferior_id (&all_processes, pid); |
| 212 | process->stop_expected = 0; |
| 213 | |
| 214 | return 0; |
| 215 | } |
| 216 | |
| 217 | /* Kill the inferior process. Make us have no inferior. */ |
| 218 | |
| 219 | static void |
| 220 | linux_kill_one_process (struct inferior_list_entry *entry) |
| 221 | { |
| 222 | struct thread_info *thread = (struct thread_info *) entry; |
| 223 | struct process_info *process = get_thread_process (thread); |
| 224 | int wstat; |
| 225 | |
| 226 | do |
| 227 | { |
| 228 | ptrace (PTRACE_KILL, pid_of (process), 0, 0); |
| 229 | |
| 230 | /* Make sure it died. The loop is most likely unnecessary. */ |
| 231 | wstat = linux_wait_for_event (thread); |
| 232 | } while (WIFSTOPPED (wstat)); |
| 233 | } |
| 234 | |
| 235 | static void |
| 236 | linux_kill (void) |
| 237 | { |
| 238 | for_each_inferior (&all_threads, linux_kill_one_process); |
| 239 | } |
| 240 | |
| 241 | static void |
| 242 | linux_detach_one_process (struct inferior_list_entry *entry) |
| 243 | { |
| 244 | struct thread_info *thread = (struct thread_info *) entry; |
| 245 | struct process_info *process = get_thread_process (thread); |
| 246 | |
| 247 | ptrace (PTRACE_DETACH, pid_of (process), 0, 0); |
| 248 | } |
| 249 | |
| 250 | static void |
| 251 | linux_detach (void) |
| 252 | { |
| 253 | for_each_inferior (&all_threads, linux_detach_one_process); |
| 254 | } |
| 255 | |
| 256 | /* Return nonzero if the given thread is still alive. */ |
| 257 | static int |
| 258 | linux_thread_alive (int tid) |
| 259 | { |
| 260 | if (find_inferior_id (&all_threads, tid) != NULL) |
| 261 | return 1; |
| 262 | else |
| 263 | return 0; |
| 264 | } |
| 265 | |
| 266 | /* Return nonzero if this process stopped at a breakpoint which |
| 267 | no longer appears to be inserted. Also adjust the PC |
| 268 | appropriately to resume where the breakpoint used to be. */ |
| 269 | static int |
| 270 | check_removed_breakpoint (struct process_info *event_child) |
| 271 | { |
| 272 | CORE_ADDR stop_pc; |
| 273 | struct thread_info *saved_inferior; |
| 274 | |
| 275 | if (event_child->pending_is_breakpoint == 0) |
| 276 | return 0; |
| 277 | |
| 278 | if (debug_threads) |
| 279 | fprintf (stderr, "Checking for breakpoint.\n"); |
| 280 | |
| 281 | saved_inferior = current_inferior; |
| 282 | current_inferior = get_process_thread (event_child); |
| 283 | |
| 284 | stop_pc = get_stop_pc (); |
| 285 | |
| 286 | /* If the PC has changed since we stopped, then we shouldn't do |
| 287 | anything. This happens if, for instance, GDB handled the |
| 288 | decr_pc_after_break subtraction itself. */ |
| 289 | if (stop_pc != event_child->pending_stop_pc) |
| 290 | { |
| 291 | if (debug_threads) |
| 292 | fprintf (stderr, "Ignoring, PC was changed.\n"); |
| 293 | |
| 294 | event_child->pending_is_breakpoint = 0; |
| 295 | current_inferior = saved_inferior; |
| 296 | return 0; |
| 297 | } |
| 298 | |
| 299 | /* If the breakpoint is still there, we will report hitting it. */ |
| 300 | if ((*the_low_target.breakpoint_at) (stop_pc)) |
| 301 | { |
| 302 | if (debug_threads) |
| 303 | fprintf (stderr, "Ignoring, breakpoint is still present.\n"); |
| 304 | current_inferior = saved_inferior; |
| 305 | return 0; |
| 306 | } |
| 307 | |
| 308 | if (debug_threads) |
| 309 | fprintf (stderr, "Removed breakpoint.\n"); |
| 310 | |
| 311 | /* For decr_pc_after_break targets, here is where we perform the |
| 312 | decrement. We go immediately from this function to resuming, |
| 313 | and can not safely call get_stop_pc () again. */ |
| 314 | if (the_low_target.set_pc != NULL) |
| 315 | (*the_low_target.set_pc) (stop_pc); |
| 316 | |
| 317 | /* We consumed the pending SIGTRAP. */ |
| 318 | event_child->pending_is_breakpoint = 0; |
| 319 | event_child->status_pending_p = 0; |
| 320 | event_child->status_pending = 0; |
| 321 | |
| 322 | current_inferior = saved_inferior; |
| 323 | return 1; |
| 324 | } |
| 325 | |
| 326 | /* Return 1 if this process has an interesting status pending. This function |
| 327 | may silently resume an inferior process. */ |
| 328 | static int |
| 329 | status_pending_p (struct inferior_list_entry *entry, void *dummy) |
| 330 | { |
| 331 | struct process_info *process = (struct process_info *) entry; |
| 332 | |
| 333 | if (process->status_pending_p) |
| 334 | if (check_removed_breakpoint (process)) |
| 335 | { |
| 336 | /* This thread was stopped at a breakpoint, and the breakpoint |
| 337 | is now gone. We were told to continue (or step...) all threads, |
| 338 | so GDB isn't trying to single-step past this breakpoint. |
| 339 | So instead of reporting the old SIGTRAP, pretend we got to |
| 340 | the breakpoint just after it was removed instead of just |
| 341 | before; resume the process. */ |
| 342 | linux_resume_one_process (&process->head, 0, 0); |
| 343 | return 0; |
| 344 | } |
| 345 | |
| 346 | return process->status_pending_p; |
| 347 | } |
| 348 | |
| 349 | static void |
| 350 | linux_wait_for_process (struct process_info **childp, int *wstatp) |
| 351 | { |
| 352 | int ret; |
| 353 | int to_wait_for = -1; |
| 354 | |
| 355 | if (*childp != NULL) |
| 356 | to_wait_for = (*childp)->lwpid; |
| 357 | |
| 358 | while (1) |
| 359 | { |
| 360 | ret = waitpid (to_wait_for, wstatp, WNOHANG); |
| 361 | |
| 362 | if (ret == -1) |
| 363 | { |
| 364 | if (errno != ECHILD) |
| 365 | perror_with_name ("waitpid"); |
| 366 | } |
| 367 | else if (ret > 0) |
| 368 | break; |
| 369 | |
| 370 | ret = waitpid (to_wait_for, wstatp, WNOHANG | __WCLONE); |
| 371 | |
| 372 | if (ret == -1) |
| 373 | { |
| 374 | if (errno != ECHILD) |
| 375 | perror_with_name ("waitpid (WCLONE)"); |
| 376 | } |
| 377 | else if (ret > 0) |
| 378 | break; |
| 379 | |
| 380 | usleep (1000); |
| 381 | } |
| 382 | |
| 383 | if (debug_threads |
| 384 | && (!WIFSTOPPED (*wstatp) |
| 385 | || (WSTOPSIG (*wstatp) != 32 |
| 386 | && WSTOPSIG (*wstatp) != 33))) |
| 387 | fprintf (stderr, "Got an event from %d (%x)\n", ret, *wstatp); |
| 388 | |
| 389 | if (to_wait_for == -1) |
| 390 | *childp = (struct process_info *) find_inferior_id (&all_processes, ret); |
| 391 | |
| 392 | (*childp)->stopped = 1; |
| 393 | (*childp)->pending_is_breakpoint = 0; |
| 394 | |
| 395 | if (debug_threads |
| 396 | && WIFSTOPPED (*wstatp)) |
| 397 | { |
| 398 | current_inferior = (struct thread_info *) |
| 399 | find_inferior_id (&all_threads, (*childp)->tid); |
| 400 | /* For testing only; i386_stop_pc prints out a diagnostic. */ |
| 401 | if (the_low_target.get_pc != NULL) |
| 402 | get_stop_pc (); |
| 403 | } |
| 404 | } |
| 405 | |
| 406 | static int |
| 407 | linux_wait_for_event (struct thread_info *child) |
| 408 | { |
| 409 | CORE_ADDR stop_pc; |
| 410 | struct process_info *event_child; |
| 411 | int wstat; |
| 412 | |
| 413 | /* Check for a process with a pending status. */ |
| 414 | /* It is possible that the user changed the pending task's registers since |
| 415 | it stopped. We correctly handle the change of PC if we hit a breakpoint |
| 416 | (in check_removed_breakpoint); signals should be reported anyway. */ |
| 417 | if (child == NULL) |
| 418 | { |
| 419 | event_child = (struct process_info *) |
| 420 | find_inferior (&all_processes, status_pending_p, NULL); |
| 421 | if (debug_threads && event_child) |
| 422 | fprintf (stderr, "Got a pending child %d\n", event_child->lwpid); |
| 423 | } |
| 424 | else |
| 425 | { |
| 426 | event_child = get_thread_process (child); |
| 427 | if (event_child->status_pending_p |
| 428 | && check_removed_breakpoint (event_child)) |
| 429 | event_child = NULL; |
| 430 | } |
| 431 | |
| 432 | if (event_child != NULL) |
| 433 | { |
| 434 | if (event_child->status_pending_p) |
| 435 | { |
| 436 | if (debug_threads) |
| 437 | fprintf (stderr, "Got an event from pending child %d (%04x)\n", |
| 438 | event_child->lwpid, event_child->status_pending); |
| 439 | wstat = event_child->status_pending; |
| 440 | event_child->status_pending_p = 0; |
| 441 | event_child->status_pending = 0; |
| 442 | current_inferior = get_process_thread (event_child); |
| 443 | return wstat; |
| 444 | } |
| 445 | } |
| 446 | |
| 447 | /* We only enter this loop if no process has a pending wait status. Thus |
| 448 | any action taken in response to a wait status inside this loop is |
| 449 | responding as soon as we detect the status, not after any pending |
| 450 | events. */ |
| 451 | while (1) |
| 452 | { |
| 453 | if (child == NULL) |
| 454 | event_child = NULL; |
| 455 | else |
| 456 | event_child = get_thread_process (child); |
| 457 | |
| 458 | linux_wait_for_process (&event_child, &wstat); |
| 459 | |
| 460 | if (event_child == NULL) |
| 461 | error ("event from unknown child"); |
| 462 | |
| 463 | current_inferior = (struct thread_info *) |
| 464 | find_inferior_id (&all_threads, event_child->tid); |
| 465 | |
| 466 | if (using_threads) |
| 467 | { |
| 468 | /* Check for thread exit. */ |
| 469 | if (! WIFSTOPPED (wstat)) |
| 470 | { |
| 471 | if (debug_threads) |
| 472 | fprintf (stderr, "Thread %d (LWP %d) exiting\n", |
| 473 | event_child->tid, event_child->head.id); |
| 474 | |
| 475 | /* If the last thread is exiting, just return. */ |
| 476 | if (all_threads.head == all_threads.tail) |
| 477 | return wstat; |
| 478 | |
| 479 | dead_thread_notify (event_child->tid); |
| 480 | |
| 481 | remove_inferior (&all_processes, &event_child->head); |
| 482 | free (event_child); |
| 483 | remove_thread (current_inferior); |
| 484 | current_inferior = (struct thread_info *) all_threads.head; |
| 485 | |
| 486 | /* If we were waiting for this particular child to do something... |
| 487 | well, it did something. */ |
| 488 | if (child != NULL) |
| 489 | return wstat; |
| 490 | |
| 491 | /* Wait for a more interesting event. */ |
| 492 | continue; |
| 493 | } |
| 494 | |
| 495 | if (WIFSTOPPED (wstat) |
| 496 | && WSTOPSIG (wstat) == SIGSTOP |
| 497 | && event_child->stop_expected) |
| 498 | { |
| 499 | if (debug_threads) |
| 500 | fprintf (stderr, "Expected stop.\n"); |
| 501 | event_child->stop_expected = 0; |
| 502 | linux_resume_one_process (&event_child->head, |
| 503 | event_child->stepping, 0); |
| 504 | continue; |
| 505 | } |
| 506 | |
| 507 | /* FIXME drow/2002-06-09: Get signal numbers from the inferior's |
| 508 | thread library? */ |
| 509 | if (WIFSTOPPED (wstat) |
| 510 | && (WSTOPSIG (wstat) == __SIGRTMIN |
| 511 | || WSTOPSIG (wstat) == __SIGRTMIN + 1)) |
| 512 | { |
| 513 | if (debug_threads) |
| 514 | fprintf (stderr, "Ignored signal %d for %d (LWP %d).\n", |
| 515 | WSTOPSIG (wstat), event_child->tid, |
| 516 | event_child->head.id); |
| 517 | linux_resume_one_process (&event_child->head, |
| 518 | event_child->stepping, |
| 519 | WSTOPSIG (wstat)); |
| 520 | continue; |
| 521 | } |
| 522 | } |
| 523 | |
| 524 | /* If this event was not handled above, and is not a SIGTRAP, report |
| 525 | it. */ |
| 526 | if (!WIFSTOPPED (wstat) || WSTOPSIG (wstat) != SIGTRAP) |
| 527 | return wstat; |
| 528 | |
| 529 | /* If this target does not support breakpoints, we simply report the |
| 530 | SIGTRAP; it's of no concern to us. */ |
| 531 | if (the_low_target.get_pc == NULL) |
| 532 | return wstat; |
| 533 | |
| 534 | stop_pc = get_stop_pc (); |
| 535 | |
| 536 | /* bp_reinsert will only be set if we were single-stepping. |
| 537 | Notice that we will resume the process after hitting |
| 538 | a gdbserver breakpoint; single-stepping to/over one |
| 539 | is not supported (yet). */ |
| 540 | if (event_child->bp_reinsert != 0) |
| 541 | { |
| 542 | if (debug_threads) |
| 543 | fprintf (stderr, "Reinserted breakpoint.\n"); |
| 544 | reinsert_breakpoint (event_child->bp_reinsert); |
| 545 | event_child->bp_reinsert = 0; |
| 546 | |
| 547 | /* Clear the single-stepping flag and SIGTRAP as we resume. */ |
| 548 | linux_resume_one_process (&event_child->head, 0, 0); |
| 549 | continue; |
| 550 | } |
| 551 | |
| 552 | if (debug_threads) |
| 553 | fprintf (stderr, "Hit a (non-reinsert) breakpoint.\n"); |
| 554 | |
| 555 | if (check_breakpoints (stop_pc) != 0) |
| 556 | { |
| 557 | /* We hit one of our own breakpoints. We mark it as a pending |
| 558 | breakpoint, so that check_removed_breakpoint () will do the PC |
| 559 | adjustment for us at the appropriate time. */ |
| 560 | event_child->pending_is_breakpoint = 1; |
| 561 | event_child->pending_stop_pc = stop_pc; |
| 562 | |
| 563 | /* Now we need to put the breakpoint back. We continue in the event |
| 564 | loop instead of simply replacing the breakpoint right away, |
| 565 | in order to not lose signals sent to the thread that hit the |
| 566 | breakpoint. Unfortunately this increases the window where another |
| 567 | thread could sneak past the removed breakpoint. For the current |
| 568 | use of server-side breakpoints (thread creation) this is |
| 569 | acceptable; but it needs to be considered before this breakpoint |
| 570 | mechanism can be used in more general ways. For some breakpoints |
| 571 | it may be necessary to stop all other threads, but that should |
| 572 | be avoided where possible. |
| 573 | |
| 574 | If breakpoint_reinsert_addr is NULL, that means that we can |
| 575 | use PTRACE_SINGLESTEP on this platform. Uninsert the breakpoint, |
| 576 | mark it for reinsertion, and single-step. |
| 577 | |
| 578 | Otherwise, call the target function to figure out where we need |
| 579 | our temporary breakpoint, create it, and continue executing this |
| 580 | process. */ |
| 581 | if (the_low_target.breakpoint_reinsert_addr == NULL) |
| 582 | { |
| 583 | event_child->bp_reinsert = stop_pc; |
| 584 | uninsert_breakpoint (stop_pc); |
| 585 | linux_resume_one_process (&event_child->head, 1, 0); |
| 586 | } |
| 587 | else |
| 588 | { |
| 589 | reinsert_breakpoint_by_bp |
| 590 | (stop_pc, (*the_low_target.breakpoint_reinsert_addr) ()); |
| 591 | linux_resume_one_process (&event_child->head, 0, 0); |
| 592 | } |
| 593 | |
| 594 | continue; |
| 595 | } |
| 596 | |
| 597 | /* If we were single-stepping, we definitely want to report the |
| 598 | SIGTRAP. The single-step operation has completed, so also |
| 599 | clear the stepping flag; in general this does not matter, |
| 600 | because the SIGTRAP will be reported to the client, which |
| 601 | will give us a new action for this thread, but clear it for |
| 602 | consistency anyway. It's safe to clear the stepping flag |
| 603 | because the only consumer of get_stop_pc () after this point |
| 604 | is check_removed_breakpoint, and pending_is_breakpoint is not |
| 605 | set. It might be wiser to use a step_completed flag instead. */ |
| 606 | if (event_child->stepping) |
| 607 | { |
| 608 | event_child->stepping = 0; |
| 609 | return wstat; |
| 610 | } |
| 611 | |
| 612 | /* A SIGTRAP that we can't explain. It may have been a breakpoint. |
| 613 | Check if it is a breakpoint, and if so mark the process information |
| 614 | accordingly. This will handle both the necessary fiddling with the |
| 615 | PC on decr_pc_after_break targets and suppressing extra threads |
| 616 | hitting a breakpoint if two hit it at once and then GDB removes it |
| 617 | after the first is reported. Arguably it would be better to report |
| 618 | multiple threads hitting breakpoints simultaneously, but the current |
| 619 | remote protocol does not allow this. */ |
| 620 | if ((*the_low_target.breakpoint_at) (stop_pc)) |
| 621 | { |
| 622 | event_child->pending_is_breakpoint = 1; |
| 623 | event_child->pending_stop_pc = stop_pc; |
| 624 | } |
| 625 | |
| 626 | return wstat; |
| 627 | } |
| 628 | |
| 629 | /* NOTREACHED */ |
| 630 | return 0; |
| 631 | } |
| 632 | |
| 633 | /* Wait for process, returns status. */ |
| 634 | |
| 635 | static unsigned char |
| 636 | linux_wait (char *status) |
| 637 | { |
| 638 | int w; |
| 639 | struct thread_info *child = NULL; |
| 640 | |
| 641 | retry: |
| 642 | /* If we were only supposed to resume one thread, only wait for |
| 643 | that thread - if it's still alive. If it died, however - which |
| 644 | can happen if we're coming from the thread death case below - |
| 645 | then we need to make sure we restart the other threads. We could |
| 646 | pick a thread at random or restart all; restarting all is less |
| 647 | arbitrary. */ |
| 648 | if (cont_thread > 0) |
| 649 | { |
| 650 | child = (struct thread_info *) find_inferior_id (&all_threads, |
| 651 | cont_thread); |
| 652 | |
| 653 | /* No stepping, no signal - unless one is pending already, of course. */ |
| 654 | if (child == NULL) |
| 655 | { |
| 656 | struct thread_resume resume_info; |
| 657 | resume_info.thread = -1; |
| 658 | resume_info.step = resume_info.sig = resume_info.leave_stopped = 0; |
| 659 | linux_resume (&resume_info); |
| 660 | } |
| 661 | } |
| 662 | |
| 663 | enable_async_io (); |
| 664 | unblock_async_io (); |
| 665 | w = linux_wait_for_event (child); |
| 666 | stop_all_processes (); |
| 667 | disable_async_io (); |
| 668 | |
| 669 | /* If we are waiting for a particular child, and it exited, |
| 670 | linux_wait_for_event will return its exit status. Similarly if |
| 671 | the last child exited. If this is not the last child, however, |
| 672 | do not report it as exited until there is a 'thread exited' response |
| 673 | available in the remote protocol. Instead, just wait for another event. |
| 674 | This should be safe, because if the thread crashed we will already |
| 675 | have reported the termination signal to GDB; that should stop any |
| 676 | in-progress stepping operations, etc. |
| 677 | |
| 678 | Report the exit status of the last thread to exit. This matches |
| 679 | LinuxThreads' behavior. */ |
| 680 | |
| 681 | if (all_threads.head == all_threads.tail) |
| 682 | { |
| 683 | if (WIFEXITED (w)) |
| 684 | { |
| 685 | fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w)); |
| 686 | *status = 'W'; |
| 687 | clear_inferiors (); |
| 688 | return ((unsigned char) WEXITSTATUS (w)); |
| 689 | } |
| 690 | else if (!WIFSTOPPED (w)) |
| 691 | { |
| 692 | fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w)); |
| 693 | clear_inferiors (); |
| 694 | *status = 'X'; |
| 695 | return ((unsigned char) WTERMSIG (w)); |
| 696 | } |
| 697 | } |
| 698 | else |
| 699 | { |
| 700 | if (!WIFSTOPPED (w)) |
| 701 | goto retry; |
| 702 | } |
| 703 | |
| 704 | *status = 'T'; |
| 705 | return ((unsigned char) WSTOPSIG (w)); |
| 706 | } |
| 707 | |
| 708 | static void |
| 709 | send_sigstop (struct inferior_list_entry *entry) |
| 710 | { |
| 711 | struct process_info *process = (struct process_info *) entry; |
| 712 | |
| 713 | if (process->stopped) |
| 714 | return; |
| 715 | |
| 716 | /* If we already have a pending stop signal for this process, don't |
| 717 | send another. */ |
| 718 | if (process->stop_expected) |
| 719 | { |
| 720 | process->stop_expected = 0; |
| 721 | return; |
| 722 | } |
| 723 | |
| 724 | if (debug_threads) |
| 725 | fprintf (stderr, "Sending sigstop to process %d\n", process->head.id); |
| 726 | |
| 727 | kill (process->head.id, SIGSTOP); |
| 728 | process->sigstop_sent = 1; |
| 729 | } |
| 730 | |
| 731 | static void |
| 732 | wait_for_sigstop (struct inferior_list_entry *entry) |
| 733 | { |
| 734 | struct process_info *process = (struct process_info *) entry; |
| 735 | struct thread_info *saved_inferior, *thread; |
| 736 | int wstat, saved_tid; |
| 737 | |
| 738 | if (process->stopped) |
| 739 | return; |
| 740 | |
| 741 | saved_inferior = current_inferior; |
| 742 | saved_tid = ((struct inferior_list_entry *) saved_inferior)->id; |
| 743 | thread = (struct thread_info *) find_inferior_id (&all_threads, |
| 744 | process->tid); |
| 745 | wstat = linux_wait_for_event (thread); |
| 746 | |
| 747 | /* If we stopped with a non-SIGSTOP signal, save it for later |
| 748 | and record the pending SIGSTOP. If the process exited, just |
| 749 | return. */ |
| 750 | if (WIFSTOPPED (wstat) |
| 751 | && WSTOPSIG (wstat) != SIGSTOP) |
| 752 | { |
| 753 | if (debug_threads) |
| 754 | fprintf (stderr, "Stopped with non-sigstop signal\n"); |
| 755 | process->status_pending_p = 1; |
| 756 | process->status_pending = wstat; |
| 757 | process->stop_expected = 1; |
| 758 | } |
| 759 | |
| 760 | if (linux_thread_alive (saved_tid)) |
| 761 | current_inferior = saved_inferior; |
| 762 | else |
| 763 | { |
| 764 | if (debug_threads) |
| 765 | fprintf (stderr, "Previously current thread died.\n"); |
| 766 | |
| 767 | /* Set a valid thread as current. */ |
| 768 | set_desired_inferior (0); |
| 769 | } |
| 770 | } |
| 771 | |
| 772 | static void |
| 773 | stop_all_processes (void) |
| 774 | { |
| 775 | stopping_threads = 1; |
| 776 | for_each_inferior (&all_processes, send_sigstop); |
| 777 | for_each_inferior (&all_processes, wait_for_sigstop); |
| 778 | stopping_threads = 0; |
| 779 | } |
| 780 | |
| 781 | /* Resume execution of the inferior process. |
| 782 | If STEP is nonzero, single-step it. |
| 783 | If SIGNAL is nonzero, give it that signal. */ |
| 784 | |
| 785 | static void |
| 786 | linux_resume_one_process (struct inferior_list_entry *entry, |
| 787 | int step, int signal) |
| 788 | { |
| 789 | struct process_info *process = (struct process_info *) entry; |
| 790 | struct thread_info *saved_inferior; |
| 791 | |
| 792 | if (process->stopped == 0) |
| 793 | return; |
| 794 | |
| 795 | /* If we have pending signals or status, and a new signal, enqueue the |
| 796 | signal. Also enqueue the signal if we are waiting to reinsert a |
| 797 | breakpoint; it will be picked up again below. */ |
| 798 | if (signal != 0 |
| 799 | && (process->status_pending_p || process->pending_signals != NULL |
| 800 | || process->bp_reinsert != 0)) |
| 801 | { |
| 802 | struct pending_signals *p_sig; |
| 803 | p_sig = malloc (sizeof (*p_sig)); |
| 804 | p_sig->prev = process->pending_signals; |
| 805 | p_sig->signal = signal; |
| 806 | process->pending_signals = p_sig; |
| 807 | } |
| 808 | |
| 809 | if (process->status_pending_p && !check_removed_breakpoint (process)) |
| 810 | return; |
| 811 | |
| 812 | saved_inferior = current_inferior; |
| 813 | current_inferior = get_process_thread (process); |
| 814 | |
| 815 | if (debug_threads) |
| 816 | fprintf (stderr, "Resuming process %d (%s, signal %d, stop %s)\n", inferior_pid, |
| 817 | step ? "step" : "continue", signal, |
| 818 | process->stop_expected ? "expected" : "not expected"); |
| 819 | |
| 820 | /* This bit needs some thinking about. If we get a signal that |
| 821 | we must report while a single-step reinsert is still pending, |
| 822 | we often end up resuming the thread. It might be better to |
| 823 | (ew) allow a stack of pending events; then we could be sure that |
| 824 | the reinsert happened right away and not lose any signals. |
| 825 | |
| 826 | Making this stack would also shrink the window in which breakpoints are |
| 827 | uninserted (see comment in linux_wait_for_process) but not enough for |
| 828 | complete correctness, so it won't solve that problem. It may be |
| 829 | worthwhile just to solve this one, however. */ |
| 830 | if (process->bp_reinsert != 0) |
| 831 | { |
| 832 | if (debug_threads) |
| 833 | fprintf (stderr, " pending reinsert at %08lx", (long)process->bp_reinsert); |
| 834 | if (step == 0) |
| 835 | fprintf (stderr, "BAD - reinserting but not stepping.\n"); |
| 836 | step = 1; |
| 837 | |
| 838 | /* Postpone any pending signal. It was enqueued above. */ |
| 839 | signal = 0; |
| 840 | } |
| 841 | |
| 842 | check_removed_breakpoint (process); |
| 843 | |
| 844 | if (debug_threads && the_low_target.get_pc != NULL) |
| 845 | { |
| 846 | fprintf (stderr, " "); |
| 847 | (long) (*the_low_target.get_pc) (); |
| 848 | } |
| 849 | |
| 850 | /* If we have pending signals, consume one unless we are trying to reinsert |
| 851 | a breakpoint. */ |
| 852 | if (process->pending_signals != NULL && process->bp_reinsert == 0) |
| 853 | { |
| 854 | struct pending_signals **p_sig; |
| 855 | |
| 856 | p_sig = &process->pending_signals; |
| 857 | while ((*p_sig)->prev != NULL) |
| 858 | p_sig = &(*p_sig)->prev; |
| 859 | |
| 860 | signal = (*p_sig)->signal; |
| 861 | free (*p_sig); |
| 862 | *p_sig = NULL; |
| 863 | } |
| 864 | |
| 865 | regcache_invalidate_one ((struct inferior_list_entry *) |
| 866 | get_process_thread (process)); |
| 867 | errno = 0; |
| 868 | process->stopped = 0; |
| 869 | process->stepping = step; |
| 870 | ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, process->lwpid, 0, signal); |
| 871 | |
| 872 | current_inferior = saved_inferior; |
| 873 | if (errno) |
| 874 | perror_with_name ("ptrace"); |
| 875 | } |
| 876 | |
| 877 | static struct thread_resume *resume_ptr; |
| 878 | |
| 879 | /* This function is called once per thread. We look up the thread |
| 880 | in RESUME_PTR, and mark the thread with a pointer to the appropriate |
| 881 | resume request. |
| 882 | |
| 883 | This algorithm is O(threads * resume elements), but resume elements |
| 884 | is small (and will remain small at least until GDB supports thread |
| 885 | suspension). */ |
| 886 | static void |
| 887 | linux_set_resume_request (struct inferior_list_entry *entry) |
| 888 | { |
| 889 | struct process_info *process; |
| 890 | struct thread_info *thread; |
| 891 | int ndx; |
| 892 | |
| 893 | thread = (struct thread_info *) entry; |
| 894 | process = get_thread_process (thread); |
| 895 | |
| 896 | ndx = 0; |
| 897 | while (resume_ptr[ndx].thread != -1 && resume_ptr[ndx].thread != entry->id) |
| 898 | ndx++; |
| 899 | |
| 900 | process->resume = &resume_ptr[ndx]; |
| 901 | } |
| 902 | |
| 903 | /* This function is called once per thread. We check the thread's resume |
| 904 | request, which will tell us whether to resume, step, or leave the thread |
| 905 | stopped; and what signal, if any, it should be sent. For threads which |
| 906 | we aren't explicitly told otherwise, we preserve the stepping flag; this |
| 907 | is used for stepping over gdbserver-placed breakpoints. */ |
| 908 | |
| 909 | static void |
| 910 | linux_continue_one_thread (struct inferior_list_entry *entry) |
| 911 | { |
| 912 | struct process_info *process; |
| 913 | struct thread_info *thread; |
| 914 | int step; |
| 915 | |
| 916 | thread = (struct thread_info *) entry; |
| 917 | process = get_thread_process (thread); |
| 918 | |
| 919 | if (process->resume->leave_stopped) |
| 920 | return; |
| 921 | |
| 922 | if (process->resume->thread == -1) |
| 923 | step = process->stepping || process->resume->step; |
| 924 | else |
| 925 | step = process->resume->step; |
| 926 | |
| 927 | linux_resume_one_process (&process->head, step, process->resume->sig); |
| 928 | |
| 929 | process->resume = NULL; |
| 930 | } |
| 931 | |
| 932 | /* This function is called once per thread. We check the thread's resume |
| 933 | request, which will tell us whether to resume, step, or leave the thread |
| 934 | stopped; and what signal, if any, it should be sent. We queue any needed |
| 935 | signals, since we won't actually resume. We already have a pending event |
| 936 | to report, so we don't need to preserve any step requests; they should |
| 937 | be re-issued if necessary. */ |
| 938 | |
| 939 | static void |
| 940 | linux_queue_one_thread (struct inferior_list_entry *entry) |
| 941 | { |
| 942 | struct process_info *process; |
| 943 | struct thread_info *thread; |
| 944 | |
| 945 | thread = (struct thread_info *) entry; |
| 946 | process = get_thread_process (thread); |
| 947 | |
| 948 | if (process->resume->leave_stopped) |
| 949 | return; |
| 950 | |
| 951 | /* If we have a new signal, enqueue the signal. */ |
| 952 | if (process->resume->sig != 0) |
| 953 | { |
| 954 | struct pending_signals *p_sig; |
| 955 | p_sig = malloc (sizeof (*p_sig)); |
| 956 | p_sig->prev = process->pending_signals; |
| 957 | p_sig->signal = process->resume->sig; |
| 958 | process->pending_signals = p_sig; |
| 959 | } |
| 960 | |
| 961 | process->resume = NULL; |
| 962 | } |
| 963 | |
| 964 | /* Set DUMMY if this process has an interesting status pending. */ |
| 965 | static int |
| 966 | resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p) |
| 967 | { |
| 968 | struct process_info *process = (struct process_info *) entry; |
| 969 | |
| 970 | /* Processes which will not be resumed are not interesting, because |
| 971 | we might not wait for them next time through linux_wait. */ |
| 972 | if (process->resume->leave_stopped) |
| 973 | return 0; |
| 974 | |
| 975 | /* If this thread has a removed breakpoint, we won't have any |
| 976 | events to report later, so check now. check_removed_breakpoint |
| 977 | may clear status_pending_p. We avoid calling check_removed_breakpoint |
| 978 | for any thread that we are not otherwise going to resume - this |
| 979 | lets us preserve stopped status when two threads hit a breakpoint. |
| 980 | GDB removes the breakpoint to single-step a particular thread |
| 981 | past it, then re-inserts it and resumes all threads. We want |
| 982 | to report the second thread without resuming it in the interim. */ |
| 983 | if (process->status_pending_p) |
| 984 | check_removed_breakpoint (process); |
| 985 | |
| 986 | if (process->status_pending_p) |
| 987 | * (int *) flag_p = 1; |
| 988 | |
| 989 | return 0; |
| 990 | } |
| 991 | |
| 992 | static void |
| 993 | linux_resume (struct thread_resume *resume_info) |
| 994 | { |
| 995 | int pending_flag; |
| 996 | |
| 997 | /* Yes, the use of a global here is rather ugly. */ |
| 998 | resume_ptr = resume_info; |
| 999 | |
| 1000 | for_each_inferior (&all_threads, linux_set_resume_request); |
| 1001 | |
| 1002 | /* If there is a thread which would otherwise be resumed, which |
| 1003 | has a pending status, then don't resume any threads - we can just |
| 1004 | report the pending status. Make sure to queue any signals |
| 1005 | that would otherwise be sent. */ |
| 1006 | pending_flag = 0; |
| 1007 | find_inferior (&all_processes, resume_status_pending_p, &pending_flag); |
| 1008 | |
| 1009 | if (debug_threads) |
| 1010 | { |
| 1011 | if (pending_flag) |
| 1012 | fprintf (stderr, "Not resuming, pending status\n"); |
| 1013 | else |
| 1014 | fprintf (stderr, "Resuming, no pending status\n"); |
| 1015 | } |
| 1016 | |
| 1017 | if (pending_flag) |
| 1018 | for_each_inferior (&all_threads, linux_queue_one_thread); |
| 1019 | else |
| 1020 | { |
| 1021 | block_async_io (); |
| 1022 | enable_async_io (); |
| 1023 | for_each_inferior (&all_threads, linux_continue_one_thread); |
| 1024 | } |
| 1025 | } |
| 1026 | |
| 1027 | #ifdef HAVE_LINUX_USRREGS |
| 1028 | |
| 1029 | int |
| 1030 | register_addr (int regnum) |
| 1031 | { |
| 1032 | int addr; |
| 1033 | |
| 1034 | if (regnum < 0 || regnum >= the_low_target.num_regs) |
| 1035 | error ("Invalid register number %d.", regnum); |
| 1036 | |
| 1037 | addr = the_low_target.regmap[regnum]; |
| 1038 | |
| 1039 | return addr; |
| 1040 | } |
| 1041 | |
| 1042 | /* Fetch one register. */ |
| 1043 | static void |
| 1044 | fetch_register (int regno) |
| 1045 | { |
| 1046 | CORE_ADDR regaddr; |
| 1047 | register int i; |
| 1048 | char *buf; |
| 1049 | |
| 1050 | if (regno >= the_low_target.num_regs) |
| 1051 | return; |
| 1052 | if ((*the_low_target.cannot_fetch_register) (regno)) |
| 1053 | return; |
| 1054 | |
| 1055 | regaddr = register_addr (regno); |
| 1056 | if (regaddr == -1) |
| 1057 | return; |
| 1058 | buf = alloca (register_size (regno)); |
| 1059 | for (i = 0; i < register_size (regno); i += sizeof (PTRACE_XFER_TYPE)) |
| 1060 | { |
| 1061 | errno = 0; |
| 1062 | *(PTRACE_XFER_TYPE *) (buf + i) = |
| 1063 | ptrace (PTRACE_PEEKUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, 0); |
| 1064 | regaddr += sizeof (PTRACE_XFER_TYPE); |
| 1065 | if (errno != 0) |
| 1066 | { |
| 1067 | /* Warning, not error, in case we are attached; sometimes the |
| 1068 | kernel doesn't let us at the registers. */ |
| 1069 | char *err = strerror (errno); |
| 1070 | char *msg = alloca (strlen (err) + 128); |
| 1071 | sprintf (msg, "reading register %d: %s", regno, err); |
| 1072 | error (msg); |
| 1073 | goto error_exit; |
| 1074 | } |
| 1075 | } |
| 1076 | supply_register (regno, buf); |
| 1077 | |
| 1078 | error_exit:; |
| 1079 | } |
| 1080 | |
| 1081 | /* Fetch all registers, or just one, from the child process. */ |
| 1082 | static void |
| 1083 | usr_fetch_inferior_registers (int regno) |
| 1084 | { |
| 1085 | if (regno == -1 || regno == 0) |
| 1086 | for (regno = 0; regno < the_low_target.num_regs; regno++) |
| 1087 | fetch_register (regno); |
| 1088 | else |
| 1089 | fetch_register (regno); |
| 1090 | } |
| 1091 | |
| 1092 | /* Store our register values back into the inferior. |
| 1093 | If REGNO is -1, do this for all registers. |
| 1094 | Otherwise, REGNO specifies which register (so we can save time). */ |
| 1095 | static void |
| 1096 | usr_store_inferior_registers (int regno) |
| 1097 | { |
| 1098 | CORE_ADDR regaddr; |
| 1099 | int i; |
| 1100 | char *buf; |
| 1101 | |
| 1102 | if (regno >= 0) |
| 1103 | { |
| 1104 | if (regno >= the_low_target.num_regs) |
| 1105 | return; |
| 1106 | |
| 1107 | if ((*the_low_target.cannot_store_register) (regno) == 1) |
| 1108 | return; |
| 1109 | |
| 1110 | regaddr = register_addr (regno); |
| 1111 | if (regaddr == -1) |
| 1112 | return; |
| 1113 | errno = 0; |
| 1114 | buf = alloca (register_size (regno)); |
| 1115 | collect_register (regno, buf); |
| 1116 | for (i = 0; i < register_size (regno); i += sizeof (PTRACE_XFER_TYPE)) |
| 1117 | { |
| 1118 | errno = 0; |
| 1119 | ptrace (PTRACE_POKEUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, |
| 1120 | *(PTRACE_XFER_TYPE *) (buf + i)); |
| 1121 | if (errno != 0) |
| 1122 | { |
| 1123 | if ((*the_low_target.cannot_store_register) (regno) == 0) |
| 1124 | { |
| 1125 | char *err = strerror (errno); |
| 1126 | char *msg = alloca (strlen (err) + 128); |
| 1127 | sprintf (msg, "writing register %d: %s", |
| 1128 | regno, err); |
| 1129 | error (msg); |
| 1130 | return; |
| 1131 | } |
| 1132 | } |
| 1133 | regaddr += sizeof (PTRACE_XFER_TYPE); |
| 1134 | } |
| 1135 | } |
| 1136 | else |
| 1137 | for (regno = 0; regno < the_low_target.num_regs; regno++) |
| 1138 | usr_store_inferior_registers (regno); |
| 1139 | } |
| 1140 | #endif /* HAVE_LINUX_USRREGS */ |
| 1141 | |
| 1142 | |
| 1143 | |
| 1144 | #ifdef HAVE_LINUX_REGSETS |
| 1145 | |
| 1146 | static int |
| 1147 | regsets_fetch_inferior_registers () |
| 1148 | { |
| 1149 | struct regset_info *regset; |
| 1150 | |
| 1151 | regset = target_regsets; |
| 1152 | |
| 1153 | while (regset->size >= 0) |
| 1154 | { |
| 1155 | void *buf; |
| 1156 | int res; |
| 1157 | |
| 1158 | if (regset->size == 0) |
| 1159 | { |
| 1160 | regset ++; |
| 1161 | continue; |
| 1162 | } |
| 1163 | |
| 1164 | buf = malloc (regset->size); |
| 1165 | res = ptrace (regset->get_request, inferior_pid, 0, buf); |
| 1166 | if (res < 0) |
| 1167 | { |
| 1168 | if (errno == EIO) |
| 1169 | { |
| 1170 | /* If we get EIO on the first regset, do not try regsets again. |
| 1171 | If we get EIO on a later regset, disable that regset. */ |
| 1172 | if (regset == target_regsets) |
| 1173 | { |
| 1174 | use_regsets_p = 0; |
| 1175 | return -1; |
| 1176 | } |
| 1177 | else |
| 1178 | { |
| 1179 | regset->size = 0; |
| 1180 | continue; |
| 1181 | } |
| 1182 | } |
| 1183 | else |
| 1184 | { |
| 1185 | char s[256]; |
| 1186 | sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d", |
| 1187 | inferior_pid); |
| 1188 | perror (s); |
| 1189 | } |
| 1190 | } |
| 1191 | regset->store_function (buf); |
| 1192 | regset ++; |
| 1193 | } |
| 1194 | return 0; |
| 1195 | } |
| 1196 | |
| 1197 | static int |
| 1198 | regsets_store_inferior_registers () |
| 1199 | { |
| 1200 | struct regset_info *regset; |
| 1201 | |
| 1202 | regset = target_regsets; |
| 1203 | |
| 1204 | while (regset->size >= 0) |
| 1205 | { |
| 1206 | void *buf; |
| 1207 | int res; |
| 1208 | |
| 1209 | if (regset->size == 0) |
| 1210 | { |
| 1211 | regset ++; |
| 1212 | continue; |
| 1213 | } |
| 1214 | |
| 1215 | buf = malloc (regset->size); |
| 1216 | regset->fill_function (buf); |
| 1217 | res = ptrace (regset->set_request, inferior_pid, 0, buf); |
| 1218 | if (res < 0) |
| 1219 | { |
| 1220 | if (errno == EIO) |
| 1221 | { |
| 1222 | /* If we get EIO on the first regset, do not try regsets again. |
| 1223 | If we get EIO on a later regset, disable that regset. */ |
| 1224 | if (regset == target_regsets) |
| 1225 | { |
| 1226 | use_regsets_p = 0; |
| 1227 | return -1; |
| 1228 | } |
| 1229 | else |
| 1230 | { |
| 1231 | regset->size = 0; |
| 1232 | continue; |
| 1233 | } |
| 1234 | } |
| 1235 | else |
| 1236 | { |
| 1237 | perror ("Warning: ptrace(regsets_store_inferior_registers)"); |
| 1238 | } |
| 1239 | } |
| 1240 | regset ++; |
| 1241 | free (buf); |
| 1242 | } |
| 1243 | return 0; |
| 1244 | } |
| 1245 | |
| 1246 | #endif /* HAVE_LINUX_REGSETS */ |
| 1247 | |
| 1248 | |
| 1249 | void |
| 1250 | linux_fetch_registers (int regno) |
| 1251 | { |
| 1252 | #ifdef HAVE_LINUX_REGSETS |
| 1253 | if (use_regsets_p) |
| 1254 | { |
| 1255 | if (regsets_fetch_inferior_registers () == 0) |
| 1256 | return; |
| 1257 | } |
| 1258 | #endif |
| 1259 | #ifdef HAVE_LINUX_USRREGS |
| 1260 | usr_fetch_inferior_registers (regno); |
| 1261 | #endif |
| 1262 | } |
| 1263 | |
| 1264 | void |
| 1265 | linux_store_registers (int regno) |
| 1266 | { |
| 1267 | #ifdef HAVE_LINUX_REGSETS |
| 1268 | if (use_regsets_p) |
| 1269 | { |
| 1270 | if (regsets_store_inferior_registers () == 0) |
| 1271 | return; |
| 1272 | } |
| 1273 | #endif |
| 1274 | #ifdef HAVE_LINUX_USRREGS |
| 1275 | usr_store_inferior_registers (regno); |
| 1276 | #endif |
| 1277 | } |
| 1278 | |
| 1279 | |
| 1280 | /* Copy LEN bytes from inferior's memory starting at MEMADDR |
| 1281 | to debugger memory starting at MYADDR. */ |
| 1282 | |
| 1283 | static int |
| 1284 | linux_read_memory (CORE_ADDR memaddr, char *myaddr, int len) |
| 1285 | { |
| 1286 | register int i; |
| 1287 | /* Round starting address down to longword boundary. */ |
| 1288 | register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); |
| 1289 | /* Round ending address up; get number of longwords that makes. */ |
| 1290 | register int count |
| 1291 | = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) |
| 1292 | / sizeof (PTRACE_XFER_TYPE); |
| 1293 | /* Allocate buffer of that many longwords. */ |
| 1294 | register PTRACE_XFER_TYPE *buffer |
| 1295 | = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE)); |
| 1296 | |
| 1297 | /* Read all the longwords */ |
| 1298 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) |
| 1299 | { |
| 1300 | errno = 0; |
| 1301 | buffer[i] = ptrace (PTRACE_PEEKTEXT, inferior_pid, (PTRACE_ARG3_TYPE) addr, 0); |
| 1302 | if (errno) |
| 1303 | return errno; |
| 1304 | } |
| 1305 | |
| 1306 | /* Copy appropriate bytes out of the buffer. */ |
| 1307 | memcpy (myaddr, (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), len); |
| 1308 | |
| 1309 | return 0; |
| 1310 | } |
| 1311 | |
| 1312 | /* Copy LEN bytes of data from debugger memory at MYADDR |
| 1313 | to inferior's memory at MEMADDR. |
| 1314 | On failure (cannot write the inferior) |
| 1315 | returns the value of errno. */ |
| 1316 | |
| 1317 | static int |
| 1318 | linux_write_memory (CORE_ADDR memaddr, const char *myaddr, int len) |
| 1319 | { |
| 1320 | register int i; |
| 1321 | /* Round starting address down to longword boundary. */ |
| 1322 | register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); |
| 1323 | /* Round ending address up; get number of longwords that makes. */ |
| 1324 | register int count |
| 1325 | = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) / sizeof (PTRACE_XFER_TYPE); |
| 1326 | /* Allocate buffer of that many longwords. */ |
| 1327 | register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE)); |
| 1328 | extern int errno; |
| 1329 | |
| 1330 | if (debug_threads) |
| 1331 | { |
| 1332 | fprintf (stderr, "Writing %02x to %08lx\n", (unsigned)myaddr[0], (long)memaddr); |
| 1333 | } |
| 1334 | |
| 1335 | /* Fill start and end extra bytes of buffer with existing memory data. */ |
| 1336 | |
| 1337 | buffer[0] = ptrace (PTRACE_PEEKTEXT, inferior_pid, |
| 1338 | (PTRACE_ARG3_TYPE) addr, 0); |
| 1339 | |
| 1340 | if (count > 1) |
| 1341 | { |
| 1342 | buffer[count - 1] |
| 1343 | = ptrace (PTRACE_PEEKTEXT, inferior_pid, |
| 1344 | (PTRACE_ARG3_TYPE) (addr + (count - 1) |
| 1345 | * sizeof (PTRACE_XFER_TYPE)), |
| 1346 | 0); |
| 1347 | } |
| 1348 | |
| 1349 | /* Copy data to be written over corresponding part of buffer */ |
| 1350 | |
| 1351 | memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), myaddr, len); |
| 1352 | |
| 1353 | /* Write the entire buffer. */ |
| 1354 | |
| 1355 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) |
| 1356 | { |
| 1357 | errno = 0; |
| 1358 | ptrace (PTRACE_POKETEXT, inferior_pid, (PTRACE_ARG3_TYPE) addr, buffer[i]); |
| 1359 | if (errno) |
| 1360 | return errno; |
| 1361 | } |
| 1362 | |
| 1363 | return 0; |
| 1364 | } |
| 1365 | |
| 1366 | static void |
| 1367 | linux_look_up_symbols (void) |
| 1368 | { |
| 1369 | #ifdef USE_THREAD_DB |
| 1370 | if (using_threads) |
| 1371 | return; |
| 1372 | |
| 1373 | using_threads = thread_db_init (); |
| 1374 | #endif |
| 1375 | } |
| 1376 | |
| 1377 | static void |
| 1378 | linux_send_signal (int signum) |
| 1379 | { |
| 1380 | extern int signal_pid; |
| 1381 | |
| 1382 | if (cont_thread > 0) |
| 1383 | { |
| 1384 | struct process_info *process; |
| 1385 | |
| 1386 | process = get_thread_process (current_inferior); |
| 1387 | kill (process->lwpid, signum); |
| 1388 | } |
| 1389 | else |
| 1390 | kill (signal_pid, signum); |
| 1391 | } |
| 1392 | |
| 1393 | /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET |
| 1394 | to debugger memory starting at MYADDR. */ |
| 1395 | |
| 1396 | static int |
| 1397 | linux_read_auxv (CORE_ADDR offset, char *myaddr, unsigned int len) |
| 1398 | { |
| 1399 | char filename[PATH_MAX]; |
| 1400 | int fd, n; |
| 1401 | |
| 1402 | snprintf (filename, sizeof filename, "/proc/%d/auxv", inferior_pid); |
| 1403 | |
| 1404 | fd = open (filename, O_RDONLY); |
| 1405 | if (fd < 0) |
| 1406 | return -1; |
| 1407 | |
| 1408 | if (offset != (CORE_ADDR) 0 |
| 1409 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) |
| 1410 | n = -1; |
| 1411 | else |
| 1412 | n = read (fd, myaddr, len); |
| 1413 | |
| 1414 | close (fd); |
| 1415 | |
| 1416 | return n; |
| 1417 | } |
| 1418 | |
| 1419 | \f |
| 1420 | static struct target_ops linux_target_ops = { |
| 1421 | linux_create_inferior, |
| 1422 | linux_attach, |
| 1423 | linux_kill, |
| 1424 | linux_detach, |
| 1425 | linux_thread_alive, |
| 1426 | linux_resume, |
| 1427 | linux_wait, |
| 1428 | linux_fetch_registers, |
| 1429 | linux_store_registers, |
| 1430 | linux_read_memory, |
| 1431 | linux_write_memory, |
| 1432 | linux_look_up_symbols, |
| 1433 | linux_send_signal, |
| 1434 | linux_read_auxv, |
| 1435 | }; |
| 1436 | |
| 1437 | static void |
| 1438 | linux_init_signals () |
| 1439 | { |
| 1440 | /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads |
| 1441 | to find what the cancel signal actually is. */ |
| 1442 | signal (__SIGRTMIN+1, SIG_IGN); |
| 1443 | } |
| 1444 | |
| 1445 | void |
| 1446 | initialize_low (void) |
| 1447 | { |
| 1448 | using_threads = 0; |
| 1449 | set_target_ops (&linux_target_ops); |
| 1450 | set_breakpoint_data (the_low_target.breakpoint, |
| 1451 | the_low_target.breakpoint_len); |
| 1452 | init_registers (); |
| 1453 | linux_init_signals (); |
| 1454 | } |