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Commit | Line | Data |
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da6d8c04 | 1 | /* Low level interface to ptrace, for the remote server for GDB. |
545587ee DJ |
2 | Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, |
3 | 2006 | |
da6d8c04 DJ |
4 | Free Software Foundation, Inc. |
5 | ||
6 | This file is part of GDB. | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program; if not, write to the Free Software | |
6f0f660e EZ |
20 | Foundation, Inc., 51 Franklin Street, Fifth Floor, |
21 | Boston, MA 02110-1301, USA. */ | |
da6d8c04 DJ |
22 | |
23 | #include "server.h" | |
58caa3dc | 24 | #include "linux-low.h" |
da6d8c04 | 25 | |
58caa3dc | 26 | #include <sys/wait.h> |
da6d8c04 DJ |
27 | #include <stdio.h> |
28 | #include <sys/param.h> | |
29 | #include <sys/dir.h> | |
30 | #include <sys/ptrace.h> | |
31 | #include <sys/user.h> | |
32 | #include <signal.h> | |
33 | #include <sys/ioctl.h> | |
34 | #include <fcntl.h> | |
d07c63e7 | 35 | #include <string.h> |
0a30fbc4 DJ |
36 | #include <stdlib.h> |
37 | #include <unistd.h> | |
fa6a77dc | 38 | #include <errno.h> |
fd500816 | 39 | #include <sys/syscall.h> |
da6d8c04 | 40 | |
0d62e5e8 DJ |
41 | /* ``all_threads'' is keyed by the LWP ID - it should be the thread ID instead, |
42 | however. This requires changing the ID in place when we go from !using_threads | |
43 | to using_threads, immediately. | |
611cb4a5 | 44 | |
0d62e5e8 DJ |
45 | ``all_processes'' is keyed by the process ID - which on Linux is (presently) |
46 | the same as the LWP ID. */ | |
47 | ||
48 | struct inferior_list all_processes; | |
49 | ||
50 | /* FIXME this is a bit of a hack, and could be removed. */ | |
51 | int stopping_threads; | |
52 | ||
53 | /* FIXME make into a target method? */ | |
54 | int using_threads; | |
55 | ||
56 | static void linux_resume_one_process (struct inferior_list_entry *entry, | |
57 | int step, int signal); | |
64386c31 | 58 | static void linux_resume (struct thread_resume *resume_info); |
0d62e5e8 DJ |
59 | static void stop_all_processes (void); |
60 | static int linux_wait_for_event (struct thread_info *child); | |
61 | ||
62 | struct pending_signals | |
63 | { | |
64 | int signal; | |
65 | struct pending_signals *prev; | |
66 | }; | |
611cb4a5 | 67 | |
d844cde6 | 68 | #define PTRACE_ARG3_TYPE long |
c6ecbae5 | 69 | #define PTRACE_XFER_TYPE long |
da6d8c04 | 70 | |
58caa3dc DJ |
71 | #ifdef HAVE_LINUX_REGSETS |
72 | static int use_regsets_p = 1; | |
73 | #endif | |
74 | ||
0d62e5e8 DJ |
75 | int debug_threads = 0; |
76 | ||
77 | #define pid_of(proc) ((proc)->head.id) | |
78 | ||
79 | /* FIXME: Delete eventually. */ | |
80 | #define inferior_pid (pid_of (get_thread_process (current_inferior))) | |
81 | ||
82 | /* This function should only be called if the process got a SIGTRAP. | |
83 | The SIGTRAP could mean several things. | |
84 | ||
85 | On i386, where decr_pc_after_break is non-zero: | |
86 | If we were single-stepping this process using PTRACE_SINGLESTEP, | |
87 | we will get only the one SIGTRAP (even if the instruction we | |
88 | stepped over was a breakpoint). The value of $eip will be the | |
89 | next instruction. | |
90 | If we continue the process using PTRACE_CONT, we will get a | |
91 | SIGTRAP when we hit a breakpoint. The value of $eip will be | |
92 | the instruction after the breakpoint (i.e. needs to be | |
93 | decremented). If we report the SIGTRAP to GDB, we must also | |
94 | report the undecremented PC. If we cancel the SIGTRAP, we | |
95 | must resume at the decremented PC. | |
96 | ||
97 | (Presumably, not yet tested) On a non-decr_pc_after_break machine | |
98 | with hardware or kernel single-step: | |
99 | If we single-step over a breakpoint instruction, our PC will | |
100 | point at the following instruction. If we continue and hit a | |
101 | breakpoint instruction, our PC will point at the breakpoint | |
102 | instruction. */ | |
103 | ||
104 | static CORE_ADDR | |
105 | get_stop_pc (void) | |
106 | { | |
107 | CORE_ADDR stop_pc = (*the_low_target.get_pc) (); | |
108 | ||
109 | if (get_thread_process (current_inferior)->stepping) | |
110 | return stop_pc; | |
111 | else | |
112 | return stop_pc - the_low_target.decr_pc_after_break; | |
113 | } | |
ce3a066d | 114 | |
0d62e5e8 | 115 | static void * |
a1928bad | 116 | add_process (unsigned long pid) |
611cb4a5 | 117 | { |
0d62e5e8 DJ |
118 | struct process_info *process; |
119 | ||
120 | process = (struct process_info *) malloc (sizeof (*process)); | |
121 | memset (process, 0, sizeof (*process)); | |
122 | ||
123 | process->head.id = pid; | |
124 | ||
125 | /* Default to tid == lwpid == pid. */ | |
126 | process->tid = pid; | |
127 | process->lwpid = pid; | |
128 | ||
129 | add_inferior_to_list (&all_processes, &process->head); | |
130 | ||
131 | return process; | |
132 | } | |
611cb4a5 | 133 | |
da6d8c04 DJ |
134 | /* Start an inferior process and returns its pid. |
135 | ALLARGS is a vector of program-name and args. */ | |
136 | ||
ce3a066d DJ |
137 | static int |
138 | linux_create_inferior (char *program, char **allargs) | |
da6d8c04 | 139 | { |
0d62e5e8 | 140 | void *new_process; |
da6d8c04 DJ |
141 | int pid; |
142 | ||
143 | pid = fork (); | |
144 | if (pid < 0) | |
145 | perror_with_name ("fork"); | |
146 | ||
147 | if (pid == 0) | |
148 | { | |
149 | ptrace (PTRACE_TRACEME, 0, 0, 0); | |
150 | ||
254787d4 | 151 | signal (__SIGRTMIN + 1, SIG_DFL); |
0d62e5e8 | 152 | |
a9fa9f7d DJ |
153 | setpgid (0, 0); |
154 | ||
da6d8c04 DJ |
155 | execv (program, allargs); |
156 | ||
157 | fprintf (stderr, "Cannot exec %s: %s.\n", program, | |
d07c63e7 | 158 | strerror (errno)); |
da6d8c04 DJ |
159 | fflush (stderr); |
160 | _exit (0177); | |
161 | } | |
162 | ||
0d62e5e8 | 163 | new_process = add_process (pid); |
a06660f7 | 164 | add_thread (pid, new_process, pid); |
611cb4a5 | 165 | |
a9fa9f7d | 166 | return pid; |
da6d8c04 DJ |
167 | } |
168 | ||
169 | /* Attach to an inferior process. */ | |
170 | ||
0d62e5e8 | 171 | void |
a1928bad | 172 | linux_attach_lwp (unsigned long pid, unsigned long tid) |
da6d8c04 | 173 | { |
0d62e5e8 | 174 | struct process_info *new_process; |
611cb4a5 | 175 | |
da6d8c04 DJ |
176 | if (ptrace (PTRACE_ATTACH, pid, 0, 0) != 0) |
177 | { | |
a1928bad | 178 | fprintf (stderr, "Cannot attach to process %ld: %s (%d)\n", pid, |
43d5792c | 179 | strerror (errno), errno); |
da6d8c04 | 180 | fflush (stderr); |
0d62e5e8 DJ |
181 | |
182 | /* If we fail to attach to an LWP, just return. */ | |
183 | if (!using_threads) | |
184 | _exit (0177); | |
185 | return; | |
da6d8c04 DJ |
186 | } |
187 | ||
0d62e5e8 | 188 | new_process = (struct process_info *) add_process (pid); |
a06660f7 | 189 | add_thread (tid, new_process, pid); |
0d62e5e8 DJ |
190 | |
191 | /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH | |
192 | brings it to a halt. We should ignore that SIGSTOP and resume the process | |
193 | (unless this is the first process, in which case the flag will be cleared | |
194 | in linux_attach). | |
195 | ||
196 | On the other hand, if we are currently trying to stop all threads, we | |
197 | should treat the new thread as if we had sent it a SIGSTOP. This works | |
198 | because we are guaranteed that add_process added us to the end of the | |
199 | list, and so the new thread has not yet reached wait_for_sigstop (but | |
200 | will). */ | |
201 | if (! stopping_threads) | |
202 | new_process->stop_expected = 1; | |
203 | } | |
204 | ||
205 | int | |
a1928bad | 206 | linux_attach (unsigned long pid) |
0d62e5e8 DJ |
207 | { |
208 | struct process_info *process; | |
209 | ||
210 | linux_attach_lwp (pid, pid); | |
211 | ||
212 | /* Don't ignore the initial SIGSTOP if we just attached to this process. */ | |
213 | process = (struct process_info *) find_inferior_id (&all_processes, pid); | |
214 | process->stop_expected = 0; | |
215 | ||
da6d8c04 DJ |
216 | return 0; |
217 | } | |
218 | ||
219 | /* Kill the inferior process. Make us have no inferior. */ | |
220 | ||
ce3a066d | 221 | static void |
0d62e5e8 | 222 | linux_kill_one_process (struct inferior_list_entry *entry) |
da6d8c04 | 223 | { |
0d62e5e8 DJ |
224 | struct thread_info *thread = (struct thread_info *) entry; |
225 | struct process_info *process = get_thread_process (thread); | |
226 | int wstat; | |
227 | ||
fd500816 DJ |
228 | /* We avoid killing the first thread here, because of a Linux kernel (at |
229 | least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before | |
230 | the children get a chance to be reaped, it will remain a zombie | |
231 | forever. */ | |
232 | if (entry == all_threads.head) | |
233 | return; | |
234 | ||
0d62e5e8 DJ |
235 | do |
236 | { | |
237 | ptrace (PTRACE_KILL, pid_of (process), 0, 0); | |
238 | ||
239 | /* Make sure it died. The loop is most likely unnecessary. */ | |
240 | wstat = linux_wait_for_event (thread); | |
241 | } while (WIFSTOPPED (wstat)); | |
da6d8c04 DJ |
242 | } |
243 | ||
0d62e5e8 DJ |
244 | static void |
245 | linux_kill (void) | |
246 | { | |
fd500816 DJ |
247 | struct thread_info *thread = (struct thread_info *) all_threads.head; |
248 | struct process_info *process = get_thread_process (thread); | |
249 | int wstat; | |
250 | ||
0d62e5e8 | 251 | for_each_inferior (&all_threads, linux_kill_one_process); |
fd500816 DJ |
252 | |
253 | /* See the comment in linux_kill_one_process. We did not kill the first | |
254 | thread in the list, so do so now. */ | |
255 | do | |
256 | { | |
257 | ptrace (PTRACE_KILL, pid_of (process), 0, 0); | |
258 | ||
259 | /* Make sure it died. The loop is most likely unnecessary. */ | |
260 | wstat = linux_wait_for_event (thread); | |
261 | } while (WIFSTOPPED (wstat)); | |
0d62e5e8 DJ |
262 | } |
263 | ||
6ad8ae5c DJ |
264 | static void |
265 | linux_detach_one_process (struct inferior_list_entry *entry) | |
266 | { | |
267 | struct thread_info *thread = (struct thread_info *) entry; | |
268 | struct process_info *process = get_thread_process (thread); | |
269 | ||
270 | ptrace (PTRACE_DETACH, pid_of (process), 0, 0); | |
271 | } | |
272 | ||
273 | static void | |
274 | linux_detach (void) | |
275 | { | |
276 | for_each_inferior (&all_threads, linux_detach_one_process); | |
277 | } | |
278 | ||
279 | /* Return nonzero if the given thread is still alive. */ | |
0d62e5e8 | 280 | static int |
a1928bad | 281 | linux_thread_alive (unsigned long tid) |
0d62e5e8 DJ |
282 | { |
283 | if (find_inferior_id (&all_threads, tid) != NULL) | |
284 | return 1; | |
285 | else | |
286 | return 0; | |
287 | } | |
288 | ||
289 | /* Return nonzero if this process stopped at a breakpoint which | |
290 | no longer appears to be inserted. Also adjust the PC | |
291 | appropriately to resume where the breakpoint used to be. */ | |
ce3a066d | 292 | static int |
0d62e5e8 | 293 | check_removed_breakpoint (struct process_info *event_child) |
da6d8c04 | 294 | { |
0d62e5e8 DJ |
295 | CORE_ADDR stop_pc; |
296 | struct thread_info *saved_inferior; | |
297 | ||
298 | if (event_child->pending_is_breakpoint == 0) | |
299 | return 0; | |
300 | ||
301 | if (debug_threads) | |
302 | fprintf (stderr, "Checking for breakpoint.\n"); | |
303 | ||
304 | saved_inferior = current_inferior; | |
305 | current_inferior = get_process_thread (event_child); | |
306 | ||
307 | stop_pc = get_stop_pc (); | |
308 | ||
309 | /* If the PC has changed since we stopped, then we shouldn't do | |
310 | anything. This happens if, for instance, GDB handled the | |
311 | decr_pc_after_break subtraction itself. */ | |
312 | if (stop_pc != event_child->pending_stop_pc) | |
313 | { | |
314 | if (debug_threads) | |
315 | fprintf (stderr, "Ignoring, PC was changed.\n"); | |
316 | ||
317 | event_child->pending_is_breakpoint = 0; | |
318 | current_inferior = saved_inferior; | |
319 | return 0; | |
320 | } | |
321 | ||
322 | /* If the breakpoint is still there, we will report hitting it. */ | |
323 | if ((*the_low_target.breakpoint_at) (stop_pc)) | |
324 | { | |
325 | if (debug_threads) | |
326 | fprintf (stderr, "Ignoring, breakpoint is still present.\n"); | |
327 | current_inferior = saved_inferior; | |
328 | return 0; | |
329 | } | |
330 | ||
331 | if (debug_threads) | |
332 | fprintf (stderr, "Removed breakpoint.\n"); | |
333 | ||
334 | /* For decr_pc_after_break targets, here is where we perform the | |
335 | decrement. We go immediately from this function to resuming, | |
336 | and can not safely call get_stop_pc () again. */ | |
337 | if (the_low_target.set_pc != NULL) | |
338 | (*the_low_target.set_pc) (stop_pc); | |
339 | ||
340 | /* We consumed the pending SIGTRAP. */ | |
5544ad89 | 341 | event_child->pending_is_breakpoint = 0; |
0d62e5e8 DJ |
342 | event_child->status_pending_p = 0; |
343 | event_child->status_pending = 0; | |
344 | ||
345 | current_inferior = saved_inferior; | |
da6d8c04 DJ |
346 | return 1; |
347 | } | |
348 | ||
0d62e5e8 DJ |
349 | /* Return 1 if this process has an interesting status pending. This function |
350 | may silently resume an inferior process. */ | |
611cb4a5 | 351 | static int |
0d62e5e8 DJ |
352 | status_pending_p (struct inferior_list_entry *entry, void *dummy) |
353 | { | |
354 | struct process_info *process = (struct process_info *) entry; | |
355 | ||
356 | if (process->status_pending_p) | |
357 | if (check_removed_breakpoint (process)) | |
358 | { | |
359 | /* This thread was stopped at a breakpoint, and the breakpoint | |
360 | is now gone. We were told to continue (or step...) all threads, | |
361 | so GDB isn't trying to single-step past this breakpoint. | |
362 | So instead of reporting the old SIGTRAP, pretend we got to | |
363 | the breakpoint just after it was removed instead of just | |
364 | before; resume the process. */ | |
365 | linux_resume_one_process (&process->head, 0, 0); | |
366 | return 0; | |
367 | } | |
368 | ||
369 | return process->status_pending_p; | |
370 | } | |
371 | ||
372 | static void | |
373 | linux_wait_for_process (struct process_info **childp, int *wstatp) | |
611cb4a5 | 374 | { |
0d62e5e8 DJ |
375 | int ret; |
376 | int to_wait_for = -1; | |
377 | ||
378 | if (*childp != NULL) | |
379 | to_wait_for = (*childp)->lwpid; | |
611cb4a5 DJ |
380 | |
381 | while (1) | |
382 | { | |
0d62e5e8 DJ |
383 | ret = waitpid (to_wait_for, wstatp, WNOHANG); |
384 | ||
385 | if (ret == -1) | |
386 | { | |
387 | if (errno != ECHILD) | |
388 | perror_with_name ("waitpid"); | |
389 | } | |
390 | else if (ret > 0) | |
391 | break; | |
392 | ||
393 | ret = waitpid (to_wait_for, wstatp, WNOHANG | __WCLONE); | |
394 | ||
395 | if (ret == -1) | |
396 | { | |
397 | if (errno != ECHILD) | |
398 | perror_with_name ("waitpid (WCLONE)"); | |
399 | } | |
400 | else if (ret > 0) | |
401 | break; | |
402 | ||
403 | usleep (1000); | |
404 | } | |
405 | ||
406 | if (debug_threads | |
407 | && (!WIFSTOPPED (*wstatp) | |
408 | || (WSTOPSIG (*wstatp) != 32 | |
409 | && WSTOPSIG (*wstatp) != 33))) | |
410 | fprintf (stderr, "Got an event from %d (%x)\n", ret, *wstatp); | |
411 | ||
412 | if (to_wait_for == -1) | |
413 | *childp = (struct process_info *) find_inferior_id (&all_processes, ret); | |
414 | ||
415 | (*childp)->stopped = 1; | |
416 | (*childp)->pending_is_breakpoint = 0; | |
417 | ||
418 | if (debug_threads | |
419 | && WIFSTOPPED (*wstatp)) | |
420 | { | |
421 | current_inferior = (struct thread_info *) | |
422 | find_inferior_id (&all_threads, (*childp)->tid); | |
423 | /* For testing only; i386_stop_pc prints out a diagnostic. */ | |
424 | if (the_low_target.get_pc != NULL) | |
425 | get_stop_pc (); | |
426 | } | |
427 | } | |
611cb4a5 | 428 | |
0d62e5e8 DJ |
429 | static int |
430 | linux_wait_for_event (struct thread_info *child) | |
431 | { | |
432 | CORE_ADDR stop_pc; | |
433 | struct process_info *event_child; | |
434 | int wstat; | |
435 | ||
436 | /* Check for a process with a pending status. */ | |
437 | /* It is possible that the user changed the pending task's registers since | |
438 | it stopped. We correctly handle the change of PC if we hit a breakpoint | |
e5379b03 | 439 | (in check_removed_breakpoint); signals should be reported anyway. */ |
0d62e5e8 DJ |
440 | if (child == NULL) |
441 | { | |
442 | event_child = (struct process_info *) | |
443 | find_inferior (&all_processes, status_pending_p, NULL); | |
444 | if (debug_threads && event_child) | |
a1928bad | 445 | fprintf (stderr, "Got a pending child %ld\n", event_child->lwpid); |
0d62e5e8 DJ |
446 | } |
447 | else | |
448 | { | |
449 | event_child = get_thread_process (child); | |
450 | if (event_child->status_pending_p | |
451 | && check_removed_breakpoint (event_child)) | |
452 | event_child = NULL; | |
453 | } | |
611cb4a5 | 454 | |
0d62e5e8 DJ |
455 | if (event_child != NULL) |
456 | { | |
457 | if (event_child->status_pending_p) | |
611cb4a5 | 458 | { |
0d62e5e8 | 459 | if (debug_threads) |
a1928bad | 460 | fprintf (stderr, "Got an event from pending child %ld (%04x)\n", |
0d62e5e8 DJ |
461 | event_child->lwpid, event_child->status_pending); |
462 | wstat = event_child->status_pending; | |
463 | event_child->status_pending_p = 0; | |
464 | event_child->status_pending = 0; | |
465 | current_inferior = get_process_thread (event_child); | |
466 | return wstat; | |
467 | } | |
468 | } | |
469 | ||
470 | /* We only enter this loop if no process has a pending wait status. Thus | |
471 | any action taken in response to a wait status inside this loop is | |
472 | responding as soon as we detect the status, not after any pending | |
473 | events. */ | |
474 | while (1) | |
475 | { | |
476 | if (child == NULL) | |
477 | event_child = NULL; | |
478 | else | |
479 | event_child = get_thread_process (child); | |
480 | ||
481 | linux_wait_for_process (&event_child, &wstat); | |
482 | ||
483 | if (event_child == NULL) | |
484 | error ("event from unknown child"); | |
611cb4a5 | 485 | |
0d62e5e8 DJ |
486 | current_inferior = (struct thread_info *) |
487 | find_inferior_id (&all_threads, event_child->tid); | |
488 | ||
489 | if (using_threads) | |
490 | { | |
491 | /* Check for thread exit. */ | |
492 | if (! WIFSTOPPED (wstat)) | |
611cb4a5 | 493 | { |
0d62e5e8 | 494 | if (debug_threads) |
a1928bad | 495 | fprintf (stderr, "Thread %ld (LWP %ld) exiting\n", |
0d62e5e8 DJ |
496 | event_child->tid, event_child->head.id); |
497 | ||
498 | /* If the last thread is exiting, just return. */ | |
499 | if (all_threads.head == all_threads.tail) | |
500 | return wstat; | |
501 | ||
502 | dead_thread_notify (event_child->tid); | |
503 | ||
504 | remove_inferior (&all_processes, &event_child->head); | |
505 | free (event_child); | |
506 | remove_thread (current_inferior); | |
507 | current_inferior = (struct thread_info *) all_threads.head; | |
508 | ||
509 | /* If we were waiting for this particular child to do something... | |
510 | well, it did something. */ | |
511 | if (child != NULL) | |
512 | return wstat; | |
513 | ||
514 | /* Wait for a more interesting event. */ | |
611cb4a5 DJ |
515 | continue; |
516 | } | |
517 | ||
0d62e5e8 DJ |
518 | if (WIFSTOPPED (wstat) |
519 | && WSTOPSIG (wstat) == SIGSTOP | |
520 | && event_child->stop_expected) | |
521 | { | |
522 | if (debug_threads) | |
523 | fprintf (stderr, "Expected stop.\n"); | |
524 | event_child->stop_expected = 0; | |
525 | linux_resume_one_process (&event_child->head, | |
526 | event_child->stepping, 0); | |
527 | continue; | |
528 | } | |
611cb4a5 | 529 | |
0d62e5e8 DJ |
530 | /* FIXME drow/2002-06-09: Get signal numbers from the inferior's |
531 | thread library? */ | |
532 | if (WIFSTOPPED (wstat) | |
254787d4 DJ |
533 | && (WSTOPSIG (wstat) == __SIGRTMIN |
534 | || WSTOPSIG (wstat) == __SIGRTMIN + 1)) | |
611cb4a5 | 535 | { |
0d62e5e8 | 536 | if (debug_threads) |
a1928bad | 537 | fprintf (stderr, "Ignored signal %d for %ld (LWP %ld).\n", |
0d62e5e8 DJ |
538 | WSTOPSIG (wstat), event_child->tid, |
539 | event_child->head.id); | |
540 | linux_resume_one_process (&event_child->head, | |
541 | event_child->stepping, | |
542 | WSTOPSIG (wstat)); | |
543 | continue; | |
544 | } | |
545 | } | |
611cb4a5 | 546 | |
0d62e5e8 DJ |
547 | /* If this event was not handled above, and is not a SIGTRAP, report |
548 | it. */ | |
549 | if (!WIFSTOPPED (wstat) || WSTOPSIG (wstat) != SIGTRAP) | |
550 | return wstat; | |
611cb4a5 | 551 | |
0d62e5e8 DJ |
552 | /* If this target does not support breakpoints, we simply report the |
553 | SIGTRAP; it's of no concern to us. */ | |
554 | if (the_low_target.get_pc == NULL) | |
555 | return wstat; | |
556 | ||
557 | stop_pc = get_stop_pc (); | |
558 | ||
559 | /* bp_reinsert will only be set if we were single-stepping. | |
560 | Notice that we will resume the process after hitting | |
561 | a gdbserver breakpoint; single-stepping to/over one | |
562 | is not supported (yet). */ | |
563 | if (event_child->bp_reinsert != 0) | |
564 | { | |
565 | if (debug_threads) | |
566 | fprintf (stderr, "Reinserted breakpoint.\n"); | |
567 | reinsert_breakpoint (event_child->bp_reinsert); | |
568 | event_child->bp_reinsert = 0; | |
569 | ||
570 | /* Clear the single-stepping flag and SIGTRAP as we resume. */ | |
571 | linux_resume_one_process (&event_child->head, 0, 0); | |
572 | continue; | |
573 | } | |
574 | ||
575 | if (debug_threads) | |
576 | fprintf (stderr, "Hit a (non-reinsert) breakpoint.\n"); | |
577 | ||
578 | if (check_breakpoints (stop_pc) != 0) | |
579 | { | |
580 | /* We hit one of our own breakpoints. We mark it as a pending | |
e5379b03 | 581 | breakpoint, so that check_removed_breakpoint () will do the PC |
0d62e5e8 DJ |
582 | adjustment for us at the appropriate time. */ |
583 | event_child->pending_is_breakpoint = 1; | |
584 | event_child->pending_stop_pc = stop_pc; | |
585 | ||
586 | /* Now we need to put the breakpoint back. We continue in the event | |
587 | loop instead of simply replacing the breakpoint right away, | |
588 | in order to not lose signals sent to the thread that hit the | |
589 | breakpoint. Unfortunately this increases the window where another | |
590 | thread could sneak past the removed breakpoint. For the current | |
591 | use of server-side breakpoints (thread creation) this is | |
592 | acceptable; but it needs to be considered before this breakpoint | |
593 | mechanism can be used in more general ways. For some breakpoints | |
594 | it may be necessary to stop all other threads, but that should | |
595 | be avoided where possible. | |
596 | ||
597 | If breakpoint_reinsert_addr is NULL, that means that we can | |
598 | use PTRACE_SINGLESTEP on this platform. Uninsert the breakpoint, | |
599 | mark it for reinsertion, and single-step. | |
600 | ||
601 | Otherwise, call the target function to figure out where we need | |
602 | our temporary breakpoint, create it, and continue executing this | |
603 | process. */ | |
604 | if (the_low_target.breakpoint_reinsert_addr == NULL) | |
605 | { | |
606 | event_child->bp_reinsert = stop_pc; | |
607 | uninsert_breakpoint (stop_pc); | |
608 | linux_resume_one_process (&event_child->head, 1, 0); | |
609 | } | |
610 | else | |
611 | { | |
612 | reinsert_breakpoint_by_bp | |
613 | (stop_pc, (*the_low_target.breakpoint_reinsert_addr) ()); | |
614 | linux_resume_one_process (&event_child->head, 0, 0); | |
611cb4a5 | 615 | } |
0d62e5e8 DJ |
616 | |
617 | continue; | |
618 | } | |
619 | ||
620 | /* If we were single-stepping, we definitely want to report the | |
621 | SIGTRAP. The single-step operation has completed, so also | |
aa691b87 | 622 | clear the stepping flag; in general this does not matter, |
0d62e5e8 DJ |
623 | because the SIGTRAP will be reported to the client, which |
624 | will give us a new action for this thread, but clear it for | |
625 | consistency anyway. It's safe to clear the stepping flag | |
626 | because the only consumer of get_stop_pc () after this point | |
e5379b03 | 627 | is check_removed_breakpoint, and pending_is_breakpoint is not |
0d62e5e8 DJ |
628 | set. It might be wiser to use a step_completed flag instead. */ |
629 | if (event_child->stepping) | |
630 | { | |
631 | event_child->stepping = 0; | |
632 | return wstat; | |
633 | } | |
634 | ||
635 | /* A SIGTRAP that we can't explain. It may have been a breakpoint. | |
636 | Check if it is a breakpoint, and if so mark the process information | |
637 | accordingly. This will handle both the necessary fiddling with the | |
638 | PC on decr_pc_after_break targets and suppressing extra threads | |
639 | hitting a breakpoint if two hit it at once and then GDB removes it | |
640 | after the first is reported. Arguably it would be better to report | |
641 | multiple threads hitting breakpoints simultaneously, but the current | |
642 | remote protocol does not allow this. */ | |
643 | if ((*the_low_target.breakpoint_at) (stop_pc)) | |
644 | { | |
645 | event_child->pending_is_breakpoint = 1; | |
646 | event_child->pending_stop_pc = stop_pc; | |
611cb4a5 DJ |
647 | } |
648 | ||
649 | return wstat; | |
650 | } | |
0d62e5e8 | 651 | |
611cb4a5 DJ |
652 | /* NOTREACHED */ |
653 | return 0; | |
654 | } | |
655 | ||
0d62e5e8 | 656 | /* Wait for process, returns status. */ |
da6d8c04 | 657 | |
ce3a066d DJ |
658 | static unsigned char |
659 | linux_wait (char *status) | |
da6d8c04 | 660 | { |
e5f1222d | 661 | int w; |
0d62e5e8 DJ |
662 | struct thread_info *child = NULL; |
663 | ||
664 | retry: | |
665 | /* If we were only supposed to resume one thread, only wait for | |
666 | that thread - if it's still alive. If it died, however - which | |
667 | can happen if we're coming from the thread death case below - | |
668 | then we need to make sure we restart the other threads. We could | |
669 | pick a thread at random or restart all; restarting all is less | |
670 | arbitrary. */ | |
d592fa2f | 671 | if (cont_thread != 0 && cont_thread != -1) |
0d62e5e8 DJ |
672 | { |
673 | child = (struct thread_info *) find_inferior_id (&all_threads, | |
674 | cont_thread); | |
675 | ||
676 | /* No stepping, no signal - unless one is pending already, of course. */ | |
677 | if (child == NULL) | |
64386c31 DJ |
678 | { |
679 | struct thread_resume resume_info; | |
680 | resume_info.thread = -1; | |
681 | resume_info.step = resume_info.sig = resume_info.leave_stopped = 0; | |
682 | linux_resume (&resume_info); | |
683 | } | |
0d62e5e8 | 684 | } |
da6d8c04 DJ |
685 | |
686 | enable_async_io (); | |
62ea82f5 | 687 | unblock_async_io (); |
0d62e5e8 DJ |
688 | w = linux_wait_for_event (child); |
689 | stop_all_processes (); | |
da6d8c04 | 690 | disable_async_io (); |
da6d8c04 | 691 | |
0d62e5e8 DJ |
692 | /* If we are waiting for a particular child, and it exited, |
693 | linux_wait_for_event will return its exit status. Similarly if | |
694 | the last child exited. If this is not the last child, however, | |
695 | do not report it as exited until there is a 'thread exited' response | |
696 | available in the remote protocol. Instead, just wait for another event. | |
697 | This should be safe, because if the thread crashed we will already | |
698 | have reported the termination signal to GDB; that should stop any | |
699 | in-progress stepping operations, etc. | |
700 | ||
701 | Report the exit status of the last thread to exit. This matches | |
702 | LinuxThreads' behavior. */ | |
703 | ||
704 | if (all_threads.head == all_threads.tail) | |
da6d8c04 | 705 | { |
0d62e5e8 DJ |
706 | if (WIFEXITED (w)) |
707 | { | |
708 | fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w)); | |
709 | *status = 'W'; | |
710 | clear_inferiors (); | |
075b3282 DJ |
711 | free (all_processes.head); |
712 | all_processes.head = all_processes.tail = NULL; | |
0d62e5e8 DJ |
713 | return ((unsigned char) WEXITSTATUS (w)); |
714 | } | |
715 | else if (!WIFSTOPPED (w)) | |
716 | { | |
717 | fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w)); | |
0d62e5e8 | 718 | *status = 'X'; |
075b3282 DJ |
719 | clear_inferiors (); |
720 | free (all_processes.head); | |
721 | all_processes.head = all_processes.tail = NULL; | |
0d62e5e8 DJ |
722 | return ((unsigned char) WTERMSIG (w)); |
723 | } | |
da6d8c04 | 724 | } |
0d62e5e8 | 725 | else |
da6d8c04 | 726 | { |
0d62e5e8 DJ |
727 | if (!WIFSTOPPED (w)) |
728 | goto retry; | |
da6d8c04 DJ |
729 | } |
730 | ||
da6d8c04 DJ |
731 | *status = 'T'; |
732 | return ((unsigned char) WSTOPSIG (w)); | |
733 | } | |
734 | ||
fd500816 DJ |
735 | /* Send a signal to an LWP. For LinuxThreads, kill is enough; however, if |
736 | thread groups are in use, we need to use tkill. */ | |
737 | ||
738 | static int | |
a1928bad | 739 | kill_lwp (unsigned long lwpid, int signo) |
fd500816 DJ |
740 | { |
741 | static int tkill_failed; | |
742 | ||
743 | errno = 0; | |
744 | ||
745 | #ifdef SYS_tkill | |
746 | if (!tkill_failed) | |
747 | { | |
748 | int ret = syscall (SYS_tkill, lwpid, signo); | |
749 | if (errno != ENOSYS) | |
750 | return ret; | |
751 | errno = 0; | |
752 | tkill_failed = 1; | |
753 | } | |
754 | #endif | |
755 | ||
756 | return kill (lwpid, signo); | |
757 | } | |
758 | ||
0d62e5e8 DJ |
759 | static void |
760 | send_sigstop (struct inferior_list_entry *entry) | |
761 | { | |
762 | struct process_info *process = (struct process_info *) entry; | |
763 | ||
764 | if (process->stopped) | |
765 | return; | |
766 | ||
767 | /* If we already have a pending stop signal for this process, don't | |
768 | send another. */ | |
769 | if (process->stop_expected) | |
770 | { | |
771 | process->stop_expected = 0; | |
772 | return; | |
773 | } | |
774 | ||
775 | if (debug_threads) | |
a1928bad | 776 | fprintf (stderr, "Sending sigstop to process %ld\n", process->head.id); |
0d62e5e8 | 777 | |
fd500816 | 778 | kill_lwp (process->head.id, SIGSTOP); |
0d62e5e8 DJ |
779 | process->sigstop_sent = 1; |
780 | } | |
781 | ||
782 | static void | |
783 | wait_for_sigstop (struct inferior_list_entry *entry) | |
784 | { | |
785 | struct process_info *process = (struct process_info *) entry; | |
786 | struct thread_info *saved_inferior, *thread; | |
a1928bad DJ |
787 | int wstat; |
788 | unsigned long saved_tid; | |
0d62e5e8 DJ |
789 | |
790 | if (process->stopped) | |
791 | return; | |
792 | ||
793 | saved_inferior = current_inferior; | |
794 | saved_tid = ((struct inferior_list_entry *) saved_inferior)->id; | |
795 | thread = (struct thread_info *) find_inferior_id (&all_threads, | |
796 | process->tid); | |
797 | wstat = linux_wait_for_event (thread); | |
798 | ||
799 | /* If we stopped with a non-SIGSTOP signal, save it for later | |
800 | and record the pending SIGSTOP. If the process exited, just | |
801 | return. */ | |
802 | if (WIFSTOPPED (wstat) | |
803 | && WSTOPSIG (wstat) != SIGSTOP) | |
804 | { | |
805 | if (debug_threads) | |
806 | fprintf (stderr, "Stopped with non-sigstop signal\n"); | |
807 | process->status_pending_p = 1; | |
808 | process->status_pending = wstat; | |
809 | process->stop_expected = 1; | |
810 | } | |
811 | ||
812 | if (linux_thread_alive (saved_tid)) | |
813 | current_inferior = saved_inferior; | |
814 | else | |
815 | { | |
816 | if (debug_threads) | |
817 | fprintf (stderr, "Previously current thread died.\n"); | |
818 | ||
819 | /* Set a valid thread as current. */ | |
820 | set_desired_inferior (0); | |
821 | } | |
822 | } | |
823 | ||
824 | static void | |
825 | stop_all_processes (void) | |
826 | { | |
827 | stopping_threads = 1; | |
828 | for_each_inferior (&all_processes, send_sigstop); | |
829 | for_each_inferior (&all_processes, wait_for_sigstop); | |
830 | stopping_threads = 0; | |
831 | } | |
832 | ||
da6d8c04 DJ |
833 | /* Resume execution of the inferior process. |
834 | If STEP is nonzero, single-step it. | |
835 | If SIGNAL is nonzero, give it that signal. */ | |
836 | ||
ce3a066d | 837 | static void |
0d62e5e8 DJ |
838 | linux_resume_one_process (struct inferior_list_entry *entry, |
839 | int step, int signal) | |
da6d8c04 | 840 | { |
0d62e5e8 DJ |
841 | struct process_info *process = (struct process_info *) entry; |
842 | struct thread_info *saved_inferior; | |
843 | ||
844 | if (process->stopped == 0) | |
845 | return; | |
846 | ||
847 | /* If we have pending signals or status, and a new signal, enqueue the | |
848 | signal. Also enqueue the signal if we are waiting to reinsert a | |
849 | breakpoint; it will be picked up again below. */ | |
850 | if (signal != 0 | |
851 | && (process->status_pending_p || process->pending_signals != NULL | |
852 | || process->bp_reinsert != 0)) | |
853 | { | |
854 | struct pending_signals *p_sig; | |
855 | p_sig = malloc (sizeof (*p_sig)); | |
856 | p_sig->prev = process->pending_signals; | |
857 | p_sig->signal = signal; | |
858 | process->pending_signals = p_sig; | |
859 | } | |
860 | ||
e5379b03 | 861 | if (process->status_pending_p && !check_removed_breakpoint (process)) |
0d62e5e8 DJ |
862 | return; |
863 | ||
864 | saved_inferior = current_inferior; | |
865 | current_inferior = get_process_thread (process); | |
866 | ||
867 | if (debug_threads) | |
a1928bad | 868 | fprintf (stderr, "Resuming process %ld (%s, signal %d, stop %s)\n", inferior_pid, |
0d62e5e8 DJ |
869 | step ? "step" : "continue", signal, |
870 | process->stop_expected ? "expected" : "not expected"); | |
871 | ||
872 | /* This bit needs some thinking about. If we get a signal that | |
873 | we must report while a single-step reinsert is still pending, | |
874 | we often end up resuming the thread. It might be better to | |
875 | (ew) allow a stack of pending events; then we could be sure that | |
876 | the reinsert happened right away and not lose any signals. | |
877 | ||
878 | Making this stack would also shrink the window in which breakpoints are | |
879 | uninserted (see comment in linux_wait_for_process) but not enough for | |
880 | complete correctness, so it won't solve that problem. It may be | |
881 | worthwhile just to solve this one, however. */ | |
882 | if (process->bp_reinsert != 0) | |
883 | { | |
884 | if (debug_threads) | |
885 | fprintf (stderr, " pending reinsert at %08lx", (long)process->bp_reinsert); | |
886 | if (step == 0) | |
887 | fprintf (stderr, "BAD - reinserting but not stepping.\n"); | |
888 | step = 1; | |
889 | ||
890 | /* Postpone any pending signal. It was enqueued above. */ | |
891 | signal = 0; | |
892 | } | |
893 | ||
894 | check_removed_breakpoint (process); | |
895 | ||
aa691b87 | 896 | if (debug_threads && the_low_target.get_pc != NULL) |
0d62e5e8 DJ |
897 | { |
898 | fprintf (stderr, " "); | |
899 | (long) (*the_low_target.get_pc) (); | |
900 | } | |
901 | ||
902 | /* If we have pending signals, consume one unless we are trying to reinsert | |
903 | a breakpoint. */ | |
904 | if (process->pending_signals != NULL && process->bp_reinsert == 0) | |
905 | { | |
906 | struct pending_signals **p_sig; | |
907 | ||
908 | p_sig = &process->pending_signals; | |
909 | while ((*p_sig)->prev != NULL) | |
910 | p_sig = &(*p_sig)->prev; | |
911 | ||
912 | signal = (*p_sig)->signal; | |
913 | free (*p_sig); | |
914 | *p_sig = NULL; | |
915 | } | |
916 | ||
917 | regcache_invalidate_one ((struct inferior_list_entry *) | |
918 | get_process_thread (process)); | |
da6d8c04 | 919 | errno = 0; |
0d62e5e8 DJ |
920 | process->stopped = 0; |
921 | process->stepping = step; | |
922 | ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, process->lwpid, 0, signal); | |
923 | ||
924 | current_inferior = saved_inferior; | |
da6d8c04 DJ |
925 | if (errno) |
926 | perror_with_name ("ptrace"); | |
927 | } | |
928 | ||
64386c31 DJ |
929 | static struct thread_resume *resume_ptr; |
930 | ||
931 | /* This function is called once per thread. We look up the thread | |
5544ad89 DJ |
932 | in RESUME_PTR, and mark the thread with a pointer to the appropriate |
933 | resume request. | |
934 | ||
935 | This algorithm is O(threads * resume elements), but resume elements | |
936 | is small (and will remain small at least until GDB supports thread | |
937 | suspension). */ | |
0d62e5e8 | 938 | static void |
5544ad89 | 939 | linux_set_resume_request (struct inferior_list_entry *entry) |
0d62e5e8 DJ |
940 | { |
941 | struct process_info *process; | |
64386c31 | 942 | struct thread_info *thread; |
5544ad89 | 943 | int ndx; |
64386c31 DJ |
944 | |
945 | thread = (struct thread_info *) entry; | |
946 | process = get_thread_process (thread); | |
947 | ||
948 | ndx = 0; | |
949 | while (resume_ptr[ndx].thread != -1 && resume_ptr[ndx].thread != entry->id) | |
950 | ndx++; | |
951 | ||
5544ad89 DJ |
952 | process->resume = &resume_ptr[ndx]; |
953 | } | |
954 | ||
955 | /* This function is called once per thread. We check the thread's resume | |
956 | request, which will tell us whether to resume, step, or leave the thread | |
957 | stopped; and what signal, if any, it should be sent. For threads which | |
958 | we aren't explicitly told otherwise, we preserve the stepping flag; this | |
959 | is used for stepping over gdbserver-placed breakpoints. */ | |
960 | ||
961 | static void | |
962 | linux_continue_one_thread (struct inferior_list_entry *entry) | |
963 | { | |
964 | struct process_info *process; | |
965 | struct thread_info *thread; | |
966 | int step; | |
967 | ||
968 | thread = (struct thread_info *) entry; | |
969 | process = get_thread_process (thread); | |
970 | ||
971 | if (process->resume->leave_stopped) | |
64386c31 DJ |
972 | return; |
973 | ||
5544ad89 DJ |
974 | if (process->resume->thread == -1) |
975 | step = process->stepping || process->resume->step; | |
64386c31 | 976 | else |
5544ad89 DJ |
977 | step = process->resume->step; |
978 | ||
979 | linux_resume_one_process (&process->head, step, process->resume->sig); | |
c6ecbae5 | 980 | |
5544ad89 DJ |
981 | process->resume = NULL; |
982 | } | |
983 | ||
984 | /* This function is called once per thread. We check the thread's resume | |
985 | request, which will tell us whether to resume, step, or leave the thread | |
986 | stopped; and what signal, if any, it should be sent. We queue any needed | |
987 | signals, since we won't actually resume. We already have a pending event | |
988 | to report, so we don't need to preserve any step requests; they should | |
989 | be re-issued if necessary. */ | |
990 | ||
991 | static void | |
992 | linux_queue_one_thread (struct inferior_list_entry *entry) | |
993 | { | |
994 | struct process_info *process; | |
995 | struct thread_info *thread; | |
996 | ||
997 | thread = (struct thread_info *) entry; | |
998 | process = get_thread_process (thread); | |
999 | ||
1000 | if (process->resume->leave_stopped) | |
1001 | return; | |
1002 | ||
1003 | /* If we have a new signal, enqueue the signal. */ | |
1004 | if (process->resume->sig != 0) | |
1005 | { | |
1006 | struct pending_signals *p_sig; | |
1007 | p_sig = malloc (sizeof (*p_sig)); | |
1008 | p_sig->prev = process->pending_signals; | |
1009 | p_sig->signal = process->resume->sig; | |
1010 | process->pending_signals = p_sig; | |
1011 | } | |
1012 | ||
1013 | process->resume = NULL; | |
1014 | } | |
1015 | ||
1016 | /* Set DUMMY if this process has an interesting status pending. */ | |
1017 | static int | |
1018 | resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p) | |
1019 | { | |
1020 | struct process_info *process = (struct process_info *) entry; | |
1021 | ||
1022 | /* Processes which will not be resumed are not interesting, because | |
1023 | we might not wait for them next time through linux_wait. */ | |
1024 | if (process->resume->leave_stopped) | |
1025 | return 0; | |
1026 | ||
1027 | /* If this thread has a removed breakpoint, we won't have any | |
1028 | events to report later, so check now. check_removed_breakpoint | |
1029 | may clear status_pending_p. We avoid calling check_removed_breakpoint | |
1030 | for any thread that we are not otherwise going to resume - this | |
1031 | lets us preserve stopped status when two threads hit a breakpoint. | |
1032 | GDB removes the breakpoint to single-step a particular thread | |
1033 | past it, then re-inserts it and resumes all threads. We want | |
1034 | to report the second thread without resuming it in the interim. */ | |
1035 | if (process->status_pending_p) | |
1036 | check_removed_breakpoint (process); | |
1037 | ||
1038 | if (process->status_pending_p) | |
1039 | * (int *) flag_p = 1; | |
1040 | ||
1041 | return 0; | |
0d62e5e8 DJ |
1042 | } |
1043 | ||
1044 | static void | |
64386c31 | 1045 | linux_resume (struct thread_resume *resume_info) |
0d62e5e8 | 1046 | { |
5544ad89 | 1047 | int pending_flag; |
c6ecbae5 | 1048 | |
5544ad89 | 1049 | /* Yes, the use of a global here is rather ugly. */ |
64386c31 | 1050 | resume_ptr = resume_info; |
5544ad89 DJ |
1051 | |
1052 | for_each_inferior (&all_threads, linux_set_resume_request); | |
1053 | ||
1054 | /* If there is a thread which would otherwise be resumed, which | |
1055 | has a pending status, then don't resume any threads - we can just | |
1056 | report the pending status. Make sure to queue any signals | |
1057 | that would otherwise be sent. */ | |
1058 | pending_flag = 0; | |
1059 | find_inferior (&all_processes, resume_status_pending_p, &pending_flag); | |
1060 | ||
1061 | if (debug_threads) | |
1062 | { | |
1063 | if (pending_flag) | |
1064 | fprintf (stderr, "Not resuming, pending status\n"); | |
1065 | else | |
1066 | fprintf (stderr, "Resuming, no pending status\n"); | |
1067 | } | |
1068 | ||
1069 | if (pending_flag) | |
1070 | for_each_inferior (&all_threads, linux_queue_one_thread); | |
1071 | else | |
62ea82f5 DJ |
1072 | { |
1073 | block_async_io (); | |
1074 | enable_async_io (); | |
1075 | for_each_inferior (&all_threads, linux_continue_one_thread); | |
1076 | } | |
0d62e5e8 DJ |
1077 | } |
1078 | ||
1079 | #ifdef HAVE_LINUX_USRREGS | |
da6d8c04 DJ |
1080 | |
1081 | int | |
0a30fbc4 | 1082 | register_addr (int regnum) |
da6d8c04 DJ |
1083 | { |
1084 | int addr; | |
1085 | ||
2ec06d2e | 1086 | if (regnum < 0 || regnum >= the_low_target.num_regs) |
da6d8c04 DJ |
1087 | error ("Invalid register number %d.", regnum); |
1088 | ||
2ec06d2e | 1089 | addr = the_low_target.regmap[regnum]; |
da6d8c04 DJ |
1090 | |
1091 | return addr; | |
1092 | } | |
1093 | ||
58caa3dc | 1094 | /* Fetch one register. */ |
da6d8c04 DJ |
1095 | static void |
1096 | fetch_register (int regno) | |
1097 | { | |
1098 | CORE_ADDR regaddr; | |
48d93c75 | 1099 | int i, size; |
0d62e5e8 | 1100 | char *buf; |
da6d8c04 | 1101 | |
2ec06d2e | 1102 | if (regno >= the_low_target.num_regs) |
0a30fbc4 | 1103 | return; |
2ec06d2e | 1104 | if ((*the_low_target.cannot_fetch_register) (regno)) |
0a30fbc4 | 1105 | return; |
da6d8c04 | 1106 | |
0a30fbc4 DJ |
1107 | regaddr = register_addr (regno); |
1108 | if (regaddr == -1) | |
1109 | return; | |
48d93c75 UW |
1110 | size = (register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1) |
1111 | & - sizeof (PTRACE_XFER_TYPE); | |
1112 | buf = alloca (size); | |
1113 | for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE)) | |
da6d8c04 DJ |
1114 | { |
1115 | errno = 0; | |
0d62e5e8 | 1116 | *(PTRACE_XFER_TYPE *) (buf + i) = |
da6d8c04 DJ |
1117 | ptrace (PTRACE_PEEKUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, 0); |
1118 | regaddr += sizeof (PTRACE_XFER_TYPE); | |
1119 | if (errno != 0) | |
1120 | { | |
1121 | /* Warning, not error, in case we are attached; sometimes the | |
1122 | kernel doesn't let us at the registers. */ | |
1123 | char *err = strerror (errno); | |
1124 | char *msg = alloca (strlen (err) + 128); | |
1125 | sprintf (msg, "reading register %d: %s", regno, err); | |
1126 | error (msg); | |
1127 | goto error_exit; | |
1128 | } | |
1129 | } | |
5a1f5858 DJ |
1130 | if (the_low_target.left_pad_xfer |
1131 | && register_size (regno) < sizeof (PTRACE_XFER_TYPE)) | |
1132 | supply_register (regno, (buf + sizeof (PTRACE_XFER_TYPE) | |
1133 | - register_size (regno))); | |
1134 | else | |
1135 | supply_register (regno, buf); | |
0d62e5e8 | 1136 | |
da6d8c04 DJ |
1137 | error_exit:; |
1138 | } | |
1139 | ||
1140 | /* Fetch all registers, or just one, from the child process. */ | |
58caa3dc DJ |
1141 | static void |
1142 | usr_fetch_inferior_registers (int regno) | |
da6d8c04 DJ |
1143 | { |
1144 | if (regno == -1 || regno == 0) | |
2ec06d2e | 1145 | for (regno = 0; regno < the_low_target.num_regs; regno++) |
da6d8c04 DJ |
1146 | fetch_register (regno); |
1147 | else | |
1148 | fetch_register (regno); | |
1149 | } | |
1150 | ||
1151 | /* Store our register values back into the inferior. | |
1152 | If REGNO is -1, do this for all registers. | |
1153 | Otherwise, REGNO specifies which register (so we can save time). */ | |
58caa3dc DJ |
1154 | static void |
1155 | usr_store_inferior_registers (int regno) | |
da6d8c04 DJ |
1156 | { |
1157 | CORE_ADDR regaddr; | |
48d93c75 | 1158 | int i, size; |
0d62e5e8 | 1159 | char *buf; |
da6d8c04 DJ |
1160 | |
1161 | if (regno >= 0) | |
1162 | { | |
2ec06d2e | 1163 | if (regno >= the_low_target.num_regs) |
0a30fbc4 DJ |
1164 | return; |
1165 | ||
bc1e36ca | 1166 | if ((*the_low_target.cannot_store_register) (regno) == 1) |
0a30fbc4 DJ |
1167 | return; |
1168 | ||
1169 | regaddr = register_addr (regno); | |
1170 | if (regaddr == -1) | |
da6d8c04 | 1171 | return; |
da6d8c04 | 1172 | errno = 0; |
48d93c75 UW |
1173 | size = (register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1) |
1174 | & - sizeof (PTRACE_XFER_TYPE); | |
1175 | buf = alloca (size); | |
1176 | memset (buf, 0, size); | |
5a1f5858 DJ |
1177 | if (the_low_target.left_pad_xfer |
1178 | && register_size (regno) < sizeof (PTRACE_XFER_TYPE)) | |
1179 | collect_register (regno, (buf + sizeof (PTRACE_XFER_TYPE) | |
1180 | - register_size (regno))); | |
1181 | else | |
1182 | collect_register (regno, buf); | |
48d93c75 | 1183 | for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE)) |
da6d8c04 | 1184 | { |
0a30fbc4 DJ |
1185 | errno = 0; |
1186 | ptrace (PTRACE_POKEUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, | |
2ff29de4 | 1187 | *(PTRACE_XFER_TYPE *) (buf + i)); |
da6d8c04 DJ |
1188 | if (errno != 0) |
1189 | { | |
bc1e36ca DJ |
1190 | if ((*the_low_target.cannot_store_register) (regno) == 0) |
1191 | { | |
1192 | char *err = strerror (errno); | |
1193 | char *msg = alloca (strlen (err) + 128); | |
1194 | sprintf (msg, "writing register %d: %s", | |
1195 | regno, err); | |
1196 | error (msg); | |
1197 | return; | |
1198 | } | |
da6d8c04 | 1199 | } |
2ff29de4 | 1200 | regaddr += sizeof (PTRACE_XFER_TYPE); |
da6d8c04 | 1201 | } |
da6d8c04 DJ |
1202 | } |
1203 | else | |
2ec06d2e | 1204 | for (regno = 0; regno < the_low_target.num_regs; regno++) |
0d62e5e8 | 1205 | usr_store_inferior_registers (regno); |
da6d8c04 | 1206 | } |
58caa3dc DJ |
1207 | #endif /* HAVE_LINUX_USRREGS */ |
1208 | ||
1209 | ||
1210 | ||
1211 | #ifdef HAVE_LINUX_REGSETS | |
1212 | ||
1213 | static int | |
0d62e5e8 | 1214 | regsets_fetch_inferior_registers () |
58caa3dc DJ |
1215 | { |
1216 | struct regset_info *regset; | |
e9d25b98 | 1217 | int saw_general_regs = 0; |
58caa3dc DJ |
1218 | |
1219 | regset = target_regsets; | |
1220 | ||
1221 | while (regset->size >= 0) | |
1222 | { | |
1223 | void *buf; | |
1224 | int res; | |
1225 | ||
1226 | if (regset->size == 0) | |
1227 | { | |
1228 | regset ++; | |
1229 | continue; | |
1230 | } | |
1231 | ||
1232 | buf = malloc (regset->size); | |
d06f167a | 1233 | res = ptrace (regset->get_request, inferior_pid, 0, buf); |
58caa3dc DJ |
1234 | if (res < 0) |
1235 | { | |
1236 | if (errno == EIO) | |
1237 | { | |
1238 | /* If we get EIO on the first regset, do not try regsets again. | |
1239 | If we get EIO on a later regset, disable that regset. */ | |
1240 | if (regset == target_regsets) | |
1241 | { | |
1242 | use_regsets_p = 0; | |
1243 | return -1; | |
1244 | } | |
1245 | else | |
1246 | { | |
1247 | regset->size = 0; | |
1248 | continue; | |
1249 | } | |
1250 | } | |
1251 | else | |
1252 | { | |
0d62e5e8 | 1253 | char s[256]; |
a1928bad | 1254 | sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%ld", |
0d62e5e8 DJ |
1255 | inferior_pid); |
1256 | perror (s); | |
58caa3dc DJ |
1257 | } |
1258 | } | |
e9d25b98 DJ |
1259 | else if (regset->type == GENERAL_REGS) |
1260 | saw_general_regs = 1; | |
58caa3dc DJ |
1261 | regset->store_function (buf); |
1262 | regset ++; | |
1263 | } | |
e9d25b98 DJ |
1264 | if (saw_general_regs) |
1265 | return 0; | |
1266 | else | |
1267 | return 1; | |
58caa3dc DJ |
1268 | } |
1269 | ||
1270 | static int | |
0d62e5e8 | 1271 | regsets_store_inferior_registers () |
58caa3dc DJ |
1272 | { |
1273 | struct regset_info *regset; | |
e9d25b98 | 1274 | int saw_general_regs = 0; |
58caa3dc DJ |
1275 | |
1276 | regset = target_regsets; | |
1277 | ||
1278 | while (regset->size >= 0) | |
1279 | { | |
1280 | void *buf; | |
1281 | int res; | |
1282 | ||
1283 | if (regset->size == 0) | |
1284 | { | |
1285 | regset ++; | |
1286 | continue; | |
1287 | } | |
1288 | ||
1289 | buf = malloc (regset->size); | |
545587ee DJ |
1290 | |
1291 | /* First fill the buffer with the current register set contents, | |
1292 | in case there are any items in the kernel's regset that are | |
1293 | not in gdbserver's regcache. */ | |
1294 | res = ptrace (regset->get_request, inferior_pid, 0, buf); | |
1295 | ||
1296 | if (res == 0) | |
1297 | { | |
1298 | /* Then overlay our cached registers on that. */ | |
1299 | regset->fill_function (buf); | |
1300 | ||
1301 | /* Only now do we write the register set. */ | |
1302 | res = ptrace (regset->set_request, inferior_pid, 0, buf); | |
1303 | } | |
1304 | ||
58caa3dc DJ |
1305 | if (res < 0) |
1306 | { | |
1307 | if (errno == EIO) | |
1308 | { | |
1309 | /* If we get EIO on the first regset, do not try regsets again. | |
1310 | If we get EIO on a later regset, disable that regset. */ | |
1311 | if (regset == target_regsets) | |
1312 | { | |
1313 | use_regsets_p = 0; | |
1314 | return -1; | |
1315 | } | |
1316 | else | |
1317 | { | |
1318 | regset->size = 0; | |
1319 | continue; | |
1320 | } | |
1321 | } | |
1322 | else | |
1323 | { | |
ce3a066d | 1324 | perror ("Warning: ptrace(regsets_store_inferior_registers)"); |
58caa3dc DJ |
1325 | } |
1326 | } | |
e9d25b98 DJ |
1327 | else if (regset->type == GENERAL_REGS) |
1328 | saw_general_regs = 1; | |
58caa3dc | 1329 | regset ++; |
09ec9b38 | 1330 | free (buf); |
58caa3dc | 1331 | } |
e9d25b98 DJ |
1332 | if (saw_general_regs) |
1333 | return 0; | |
1334 | else | |
1335 | return 1; | |
ce3a066d | 1336 | return 0; |
58caa3dc DJ |
1337 | } |
1338 | ||
1339 | #endif /* HAVE_LINUX_REGSETS */ | |
1340 | ||
1341 | ||
1342 | void | |
ce3a066d | 1343 | linux_fetch_registers (int regno) |
58caa3dc DJ |
1344 | { |
1345 | #ifdef HAVE_LINUX_REGSETS | |
1346 | if (use_regsets_p) | |
1347 | { | |
1348 | if (regsets_fetch_inferior_registers () == 0) | |
1349 | return; | |
1350 | } | |
1351 | #endif | |
1352 | #ifdef HAVE_LINUX_USRREGS | |
1353 | usr_fetch_inferior_registers (regno); | |
1354 | #endif | |
1355 | } | |
1356 | ||
1357 | void | |
ce3a066d | 1358 | linux_store_registers (int regno) |
58caa3dc DJ |
1359 | { |
1360 | #ifdef HAVE_LINUX_REGSETS | |
1361 | if (use_regsets_p) | |
1362 | { | |
1363 | if (regsets_store_inferior_registers () == 0) | |
1364 | return; | |
1365 | } | |
1366 | #endif | |
1367 | #ifdef HAVE_LINUX_USRREGS | |
1368 | usr_store_inferior_registers (regno); | |
1369 | #endif | |
1370 | } | |
1371 | ||
da6d8c04 | 1372 | |
da6d8c04 DJ |
1373 | /* Copy LEN bytes from inferior's memory starting at MEMADDR |
1374 | to debugger memory starting at MYADDR. */ | |
1375 | ||
c3e735a6 | 1376 | static int |
f450004a | 1377 | linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len) |
da6d8c04 DJ |
1378 | { |
1379 | register int i; | |
1380 | /* Round starting address down to longword boundary. */ | |
1381 | register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); | |
1382 | /* Round ending address up; get number of longwords that makes. */ | |
aa691b87 RM |
1383 | register int count |
1384 | = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) | |
da6d8c04 DJ |
1385 | / sizeof (PTRACE_XFER_TYPE); |
1386 | /* Allocate buffer of that many longwords. */ | |
aa691b87 | 1387 | register PTRACE_XFER_TYPE *buffer |
da6d8c04 DJ |
1388 | = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE)); |
1389 | ||
1390 | /* Read all the longwords */ | |
1391 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) | |
1392 | { | |
c3e735a6 | 1393 | errno = 0; |
d844cde6 | 1394 | buffer[i] = ptrace (PTRACE_PEEKTEXT, inferior_pid, (PTRACE_ARG3_TYPE) addr, 0); |
c3e735a6 DJ |
1395 | if (errno) |
1396 | return errno; | |
da6d8c04 DJ |
1397 | } |
1398 | ||
1399 | /* Copy appropriate bytes out of the buffer. */ | |
1400 | memcpy (myaddr, (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), len); | |
c3e735a6 DJ |
1401 | |
1402 | return 0; | |
da6d8c04 DJ |
1403 | } |
1404 | ||
1405 | /* Copy LEN bytes of data from debugger memory at MYADDR | |
1406 | to inferior's memory at MEMADDR. | |
1407 | On failure (cannot write the inferior) | |
1408 | returns the value of errno. */ | |
1409 | ||
ce3a066d | 1410 | static int |
f450004a | 1411 | linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len) |
da6d8c04 DJ |
1412 | { |
1413 | register int i; | |
1414 | /* Round starting address down to longword boundary. */ | |
1415 | register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); | |
1416 | /* Round ending address up; get number of longwords that makes. */ | |
1417 | register int count | |
1418 | = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) / sizeof (PTRACE_XFER_TYPE); | |
1419 | /* Allocate buffer of that many longwords. */ | |
1420 | register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE)); | |
1421 | extern int errno; | |
1422 | ||
0d62e5e8 DJ |
1423 | if (debug_threads) |
1424 | { | |
1425 | fprintf (stderr, "Writing %02x to %08lx\n", (unsigned)myaddr[0], (long)memaddr); | |
1426 | } | |
1427 | ||
da6d8c04 DJ |
1428 | /* Fill start and end extra bytes of buffer with existing memory data. */ |
1429 | ||
d844cde6 DJ |
1430 | buffer[0] = ptrace (PTRACE_PEEKTEXT, inferior_pid, |
1431 | (PTRACE_ARG3_TYPE) addr, 0); | |
da6d8c04 DJ |
1432 | |
1433 | if (count > 1) | |
1434 | { | |
1435 | buffer[count - 1] | |
1436 | = ptrace (PTRACE_PEEKTEXT, inferior_pid, | |
d844cde6 DJ |
1437 | (PTRACE_ARG3_TYPE) (addr + (count - 1) |
1438 | * sizeof (PTRACE_XFER_TYPE)), | |
1439 | 0); | |
da6d8c04 DJ |
1440 | } |
1441 | ||
1442 | /* Copy data to be written over corresponding part of buffer */ | |
1443 | ||
1444 | memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), myaddr, len); | |
1445 | ||
1446 | /* Write the entire buffer. */ | |
1447 | ||
1448 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) | |
1449 | { | |
1450 | errno = 0; | |
d844cde6 | 1451 | ptrace (PTRACE_POKETEXT, inferior_pid, (PTRACE_ARG3_TYPE) addr, buffer[i]); |
da6d8c04 DJ |
1452 | if (errno) |
1453 | return errno; | |
1454 | } | |
1455 | ||
1456 | return 0; | |
1457 | } | |
2f2893d9 DJ |
1458 | |
1459 | static void | |
1460 | linux_look_up_symbols (void) | |
1461 | { | |
0d62e5e8 DJ |
1462 | #ifdef USE_THREAD_DB |
1463 | if (using_threads) | |
1464 | return; | |
1465 | ||
1466 | using_threads = thread_db_init (); | |
1467 | #endif | |
1468 | } | |
1469 | ||
e5379b03 DJ |
1470 | static void |
1471 | linux_send_signal (int signum) | |
1472 | { | |
a1928bad | 1473 | extern unsigned long signal_pid; |
e5379b03 | 1474 | |
d592fa2f | 1475 | if (cont_thread != 0 && cont_thread != -1) |
e5379b03 DJ |
1476 | { |
1477 | struct process_info *process; | |
1478 | ||
1479 | process = get_thread_process (current_inferior); | |
fd500816 | 1480 | kill_lwp (process->lwpid, signum); |
e5379b03 DJ |
1481 | } |
1482 | else | |
fd500816 | 1483 | kill_lwp (signal_pid, signum); |
e5379b03 DJ |
1484 | } |
1485 | ||
aa691b87 RM |
1486 | /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET |
1487 | to debugger memory starting at MYADDR. */ | |
1488 | ||
1489 | static int | |
f450004a | 1490 | linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len) |
aa691b87 RM |
1491 | { |
1492 | char filename[PATH_MAX]; | |
1493 | int fd, n; | |
1494 | ||
a1928bad | 1495 | snprintf (filename, sizeof filename, "/proc/%ld/auxv", inferior_pid); |
aa691b87 RM |
1496 | |
1497 | fd = open (filename, O_RDONLY); | |
1498 | if (fd < 0) | |
1499 | return -1; | |
1500 | ||
1501 | if (offset != (CORE_ADDR) 0 | |
1502 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) | |
1503 | n = -1; | |
1504 | else | |
1505 | n = read (fd, myaddr, len); | |
1506 | ||
1507 | close (fd); | |
1508 | ||
1509 | return n; | |
1510 | } | |
1511 | ||
e013ee27 OF |
1512 | /* These watchpoint related wrapper functions simply pass on the function call |
1513 | if the target has registered a corresponding function. */ | |
1514 | ||
1515 | static int | |
1516 | linux_insert_watchpoint (char type, CORE_ADDR addr, int len) | |
1517 | { | |
1518 | if (the_low_target.insert_watchpoint != NULL) | |
1519 | return the_low_target.insert_watchpoint (type, addr, len); | |
1520 | else | |
1521 | /* Unsupported (see target.h). */ | |
1522 | return 1; | |
1523 | } | |
1524 | ||
1525 | static int | |
1526 | linux_remove_watchpoint (char type, CORE_ADDR addr, int len) | |
1527 | { | |
1528 | if (the_low_target.remove_watchpoint != NULL) | |
1529 | return the_low_target.remove_watchpoint (type, addr, len); | |
1530 | else | |
1531 | /* Unsupported (see target.h). */ | |
1532 | return 1; | |
1533 | } | |
1534 | ||
1535 | static int | |
1536 | linux_stopped_by_watchpoint (void) | |
1537 | { | |
1538 | if (the_low_target.stopped_by_watchpoint != NULL) | |
1539 | return the_low_target.stopped_by_watchpoint (); | |
1540 | else | |
1541 | return 0; | |
1542 | } | |
1543 | ||
1544 | static CORE_ADDR | |
1545 | linux_stopped_data_address (void) | |
1546 | { | |
1547 | if (the_low_target.stopped_data_address != NULL) | |
1548 | return the_low_target.stopped_data_address (); | |
1549 | else | |
1550 | return 0; | |
1551 | } | |
1552 | ||
ce3a066d DJ |
1553 | static struct target_ops linux_target_ops = { |
1554 | linux_create_inferior, | |
1555 | linux_attach, | |
1556 | linux_kill, | |
6ad8ae5c | 1557 | linux_detach, |
ce3a066d DJ |
1558 | linux_thread_alive, |
1559 | linux_resume, | |
1560 | linux_wait, | |
1561 | linux_fetch_registers, | |
1562 | linux_store_registers, | |
1563 | linux_read_memory, | |
1564 | linux_write_memory, | |
2f2893d9 | 1565 | linux_look_up_symbols, |
e5379b03 | 1566 | linux_send_signal, |
aa691b87 | 1567 | linux_read_auxv, |
e013ee27 OF |
1568 | linux_insert_watchpoint, |
1569 | linux_remove_watchpoint, | |
1570 | linux_stopped_by_watchpoint, | |
1571 | linux_stopped_data_address, | |
ce3a066d DJ |
1572 | }; |
1573 | ||
0d62e5e8 DJ |
1574 | static void |
1575 | linux_init_signals () | |
1576 | { | |
1577 | /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads | |
1578 | to find what the cancel signal actually is. */ | |
254787d4 | 1579 | signal (__SIGRTMIN+1, SIG_IGN); |
0d62e5e8 DJ |
1580 | } |
1581 | ||
da6d8c04 DJ |
1582 | void |
1583 | initialize_low (void) | |
1584 | { | |
0d62e5e8 | 1585 | using_threads = 0; |
ce3a066d | 1586 | set_target_ops (&linux_target_ops); |
611cb4a5 DJ |
1587 | set_breakpoint_data (the_low_target.breakpoint, |
1588 | the_low_target.breakpoint_len); | |
0a30fbc4 | 1589 | init_registers (); |
0d62e5e8 | 1590 | linux_init_signals (); |
da6d8c04 | 1591 | } |