Commit | Line | Data |
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ac264b3b MS |
1 | /* GNU/Linux native-dependent code for debugging multiple forks. |
2 | ||
28e7fd62 | 3 | Copyright (C) 2005-2013 Free Software Foundation, Inc. |
ac264b3b MS |
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 | |
a9762ec7 | 9 | the Free Software Foundation; either version 3 of the License, or |
ac264b3b MS |
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 | |
a9762ec7 | 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
ac264b3b MS |
19 | |
20 | #include "defs.h" | |
5af949e3 | 21 | #include "arch-utils.h" |
ac264b3b MS |
22 | #include "inferior.h" |
23 | #include "regcache.h" | |
24 | #include "gdbcmd.h" | |
25 | #include "infcall.h" | |
3e3b026f | 26 | #include "objfiles.h" |
791b663b | 27 | #include "gdb_assert.h" |
0e9f083f | 28 | #include <string.h> |
ac264b3b | 29 | #include "linux-fork.h" |
f973ed9c | 30 | #include "linux-nat.h" |
7a298875 | 31 | #include "gdbthread.h" |
05cba821 | 32 | #include "source.h" |
ac264b3b MS |
33 | |
34 | #include <sys/ptrace.h> | |
3c61c145 | 35 | #include "gdb_wait.h" |
2978b111 | 36 | #include <dirent.h> |
ac264b3b MS |
37 | #include <ctype.h> |
38 | ||
39 | struct fork_info *fork_list; | |
40 | static int highest_fork_num; | |
41 | ||
42 | /* Prevent warning from -Wmissing-prototypes. */ | |
43 | extern void _initialize_linux_fork (void); | |
44 | ||
ac264b3b MS |
45 | /* Fork list data structure: */ |
46 | struct fork_info | |
47 | { | |
48 | struct fork_info *next; | |
49 | ptid_t ptid; | |
7a298875 | 50 | ptid_t parent_ptid; |
1777feb0 | 51 | int num; /* Convenient handle (GDB fork id). */ |
3cb5bea9 | 52 | struct regcache *savedregs; /* Convenient for info fork, saves |
ac264b3b MS |
53 | having to actually switch contexts. */ |
54 | int clobber_regs; /* True if we should restore saved regs. */ | |
ac264b3b MS |
55 | off_t *filepos; /* Set of open file descriptors' offsets. */ |
56 | int maxfd; | |
57 | }; | |
58 | ||
59 | /* Fork list methods: */ | |
60 | ||
3cb5bea9 | 61 | int |
ac264b3b MS |
62 | forks_exist_p (void) |
63 | { | |
64 | return (fork_list != NULL); | |
65 | } | |
66 | ||
3cb5bea9 | 67 | /* Add a fork to the internal fork list. */ |
ac264b3b | 68 | |
3cb5bea9 | 69 | struct fork_info * |
ac264b3b MS |
70 | add_fork (pid_t pid) |
71 | { | |
72 | struct fork_info *fp; | |
73 | ||
dfd4cc63 | 74 | if (fork_list == NULL && pid != ptid_get_pid (inferior_ptid)) |
ac264b3b MS |
75 | { |
76 | /* Special case -- if this is the first fork in the list | |
77 | (the list is hitherto empty), and if this new fork is | |
78 | NOT the current inferior_ptid, then add inferior_ptid | |
79 | first, as a special zeroeth fork id. */ | |
80 | highest_fork_num = -1; | |
dfd4cc63 | 81 | add_fork (ptid_get_pid (inferior_ptid)); /* safe recursion */ |
ac264b3b MS |
82 | } |
83 | ||
84 | fp = XZALLOC (struct fork_info); | |
f973ed9c | 85 | fp->ptid = ptid_build (pid, pid, 0); |
ac264b3b MS |
86 | fp->num = ++highest_fork_num; |
87 | fp->next = fork_list; | |
88 | fork_list = fp; | |
89 | return fp; | |
90 | } | |
91 | ||
92 | static void | |
93 | free_fork (struct fork_info *fp) | |
94 | { | |
95 | /* Notes on step-resume breakpoints: since this is a concern for | |
96 | threads, let's convince ourselves that it's not a concern for | |
97 | forks. There are two ways for a fork_info to be created. First, | |
98 | by the checkpoint command, in which case we're at a gdb prompt | |
99 | and there can't be any step-resume breakpoint. Second, by a fork | |
100 | in the user program, in which case we *may* have stepped into the | |
101 | fork call, but regardless of whether we follow the parent or the | |
102 | child, we will return to the same place and the step-resume | |
103 | breakpoint, if any, will take care of itself as usual. And | |
104 | unlike threads, we do not save a private copy of the step-resume | |
105 | breakpoint -- so we're OK. */ | |
106 | ||
107 | if (fp) | |
108 | { | |
109 | if (fp->savedregs) | |
110 | regcache_xfree (fp->savedregs); | |
111 | if (fp->filepos) | |
112 | xfree (fp->filepos); | |
113 | xfree (fp); | |
114 | } | |
115 | } | |
116 | ||
117 | static void | |
118 | delete_fork (ptid_t ptid) | |
119 | { | |
120 | struct fork_info *fp, *fpprev; | |
121 | ||
122 | fpprev = NULL; | |
123 | ||
26cb8b7c PA |
124 | linux_nat_forget_process (ptid_get_pid (ptid)); |
125 | ||
ac264b3b MS |
126 | for (fp = fork_list; fp; fpprev = fp, fp = fp->next) |
127 | if (ptid_equal (fp->ptid, ptid)) | |
128 | break; | |
129 | ||
130 | if (!fp) | |
131 | return; | |
132 | ||
133 | if (fpprev) | |
134 | fpprev->next = fp->next; | |
135 | else | |
136 | fork_list = fp->next; | |
137 | ||
138 | free_fork (fp); | |
139 | ||
3cb5bea9 | 140 | /* Special case: if there is now only one process in the list, |
ac264b3b MS |
141 | and if it is (hopefully!) the current inferior_ptid, then |
142 | remove it, leaving the list empty -- we're now down to the | |
143 | default case of debugging a single process. */ | |
144 | if (fork_list != NULL && fork_list->next == NULL && | |
145 | ptid_equal (fork_list->ptid, inferior_ptid)) | |
146 | { | |
147 | /* Last fork -- delete from list and handle as solo process | |
148 | (should be a safe recursion). */ | |
149 | delete_fork (inferior_ptid); | |
150 | } | |
151 | } | |
152 | ||
153 | /* Find a fork_info by matching PTID. */ | |
154 | static struct fork_info * | |
155 | find_fork_ptid (ptid_t ptid) | |
156 | { | |
157 | struct fork_info *fp; | |
158 | ||
159 | for (fp = fork_list; fp; fp = fp->next) | |
160 | if (ptid_equal (fp->ptid, ptid)) | |
161 | return fp; | |
162 | ||
163 | return NULL; | |
164 | } | |
165 | ||
166 | /* Find a fork_info by matching ID. */ | |
167 | static struct fork_info * | |
168 | find_fork_id (int num) | |
169 | { | |
170 | struct fork_info *fp; | |
171 | ||
172 | for (fp = fork_list; fp; fp = fp->next) | |
173 | if (fp->num == num) | |
174 | return fp; | |
175 | ||
176 | return NULL; | |
177 | } | |
178 | ||
179 | /* Find a fork_info by matching pid. */ | |
180 | extern struct fork_info * | |
181 | find_fork_pid (pid_t pid) | |
182 | { | |
183 | struct fork_info *fp; | |
184 | ||
185 | for (fp = fork_list; fp; fp = fp->next) | |
186 | if (pid == ptid_get_pid (fp->ptid)) | |
187 | return fp; | |
188 | ||
189 | return NULL; | |
190 | } | |
191 | ||
192 | static ptid_t | |
193 | fork_id_to_ptid (int num) | |
194 | { | |
195 | struct fork_info *fork = find_fork_id (num); | |
196 | if (fork) | |
197 | return fork->ptid; | |
198 | else | |
199 | return pid_to_ptid (-1); | |
200 | } | |
201 | ||
202 | static void | |
203 | init_fork_list (void) | |
204 | { | |
205 | struct fork_info *fp, *fpnext; | |
206 | ||
207 | if (!fork_list) | |
208 | return; | |
209 | ||
210 | for (fp = fork_list; fp; fp = fpnext) | |
211 | { | |
212 | fpnext = fp->next; | |
213 | free_fork (fp); | |
214 | } | |
215 | ||
216 | fork_list = NULL; | |
217 | } | |
218 | ||
219 | /* Fork list <-> gdb interface. */ | |
220 | ||
3cb5bea9 | 221 | /* Utility function for fork_load/fork_save. |
ac264b3b MS |
222 | Calls lseek in the (current) inferior process. */ |
223 | ||
224 | static off_t | |
225 | call_lseek (int fd, off_t offset, int whence) | |
226 | { | |
227 | char exp[80]; | |
228 | ||
229 | snprintf (&exp[0], sizeof (exp), "lseek (%d, %ld, %d)", | |
230 | fd, (long) offset, whence); | |
231 | return (off_t) parse_and_eval_long (&exp[0]); | |
232 | } | |
233 | ||
234 | /* Load infrun state for the fork PTID. */ | |
235 | ||
236 | static void | |
237 | fork_load_infrun_state (struct fork_info *fp) | |
238 | { | |
239 | extern void nullify_last_target_wait_ptid (); | |
240 | int i; | |
241 | ||
2277426b | 242 | linux_nat_switch_fork (fp->ptid); |
f973ed9c | 243 | |
ac264b3b | 244 | if (fp->savedregs && fp->clobber_regs) |
594f7785 | 245 | regcache_cpy (get_current_regcache (), fp->savedregs); |
ac264b3b | 246 | |
791b663b DJ |
247 | registers_changed (); |
248 | reinit_frame_cache (); | |
249 | ||
fb14de7b | 250 | stop_pc = regcache_read_pc (get_current_regcache ()); |
ac264b3b MS |
251 | nullify_last_target_wait_ptid (); |
252 | ||
253 | /* Now restore the file positions of open file descriptors. */ | |
254 | if (fp->filepos) | |
255 | { | |
256 | for (i = 0; i <= fp->maxfd; i++) | |
257 | if (fp->filepos[i] != (off_t) -1) | |
258 | call_lseek (i, fp->filepos[i], SEEK_SET); | |
259 | /* NOTE: I can get away with using SEEK_SET and SEEK_CUR because | |
260 | this is native-only. If it ever has to be cross, we'll have | |
261 | to rethink this. */ | |
262 | } | |
263 | } | |
264 | ||
265 | /* Save infrun state for the fork PTID. | |
266 | Exported for use by linux child_follow_fork. */ | |
267 | ||
2277426b | 268 | static void |
ac264b3b MS |
269 | fork_save_infrun_state (struct fork_info *fp, int clobber_regs) |
270 | { | |
d8d2a3ee | 271 | char path[PATH_MAX]; |
ac264b3b MS |
272 | struct dirent *de; |
273 | DIR *d; | |
274 | ||
275 | if (fp->savedregs) | |
276 | regcache_xfree (fp->savedregs); | |
277 | ||
594f7785 | 278 | fp->savedregs = regcache_dup (get_current_regcache ()); |
ac264b3b | 279 | fp->clobber_regs = clobber_regs; |
ac264b3b MS |
280 | |
281 | if (clobber_regs) | |
282 | { | |
283 | /* Now save the 'state' (file position) of all open file descriptors. | |
284 | Unfortunately fork does not take care of that for us... */ | |
dfd4cc63 LM |
285 | snprintf (path, PATH_MAX, "/proc/%ld/fd", |
286 | (long) ptid_get_pid (fp->ptid)); | |
ac264b3b MS |
287 | if ((d = opendir (path)) != NULL) |
288 | { | |
289 | long tmp; | |
290 | ||
291 | fp->maxfd = 0; | |
292 | while ((de = readdir (d)) != NULL) | |
293 | { | |
294 | /* Count open file descriptors (actually find highest | |
295 | numbered). */ | |
296 | tmp = strtol (&de->d_name[0], NULL, 10); | |
297 | if (fp->maxfd < tmp) | |
298 | fp->maxfd = tmp; | |
299 | } | |
300 | /* Allocate array of file positions. */ | |
3cb5bea9 | 301 | fp->filepos = xrealloc (fp->filepos, |
ac264b3b MS |
302 | (fp->maxfd + 1) * sizeof (*fp->filepos)); |
303 | ||
304 | /* Initialize to -1 (invalid). */ | |
305 | for (tmp = 0; tmp <= fp->maxfd; tmp++) | |
306 | fp->filepos[tmp] = -1; | |
307 | ||
308 | /* Now find actual file positions. */ | |
309 | rewinddir (d); | |
310 | while ((de = readdir (d)) != NULL) | |
311 | if (isdigit (de->d_name[0])) | |
312 | { | |
313 | tmp = strtol (&de->d_name[0], NULL, 10); | |
314 | fp->filepos[tmp] = call_lseek (tmp, 0, SEEK_CUR); | |
315 | } | |
316 | closedir (d); | |
317 | } | |
318 | } | |
319 | } | |
320 | ||
321 | /* Kill 'em all, let God sort 'em out... */ | |
322 | ||
3cb5bea9 | 323 | void |
ac264b3b MS |
324 | linux_fork_killall (void) |
325 | { | |
326 | /* Walk list and kill every pid. No need to treat the | |
327 | current inferior_ptid as special (we do not return a | |
328 | status for it) -- however any process may be a child | |
329 | or a parent, so may get a SIGCHLD from a previously | |
330 | killed child. Wait them all out. */ | |
56aac7e8 | 331 | struct fork_info *fp; |
ac264b3b MS |
332 | pid_t pid, ret; |
333 | int status; | |
334 | ||
56aac7e8 MS |
335 | for (fp = fork_list; fp; fp = fp->next) |
336 | { | |
dfd4cc63 | 337 | pid = ptid_get_pid (fp->ptid); |
56aac7e8 | 338 | do { |
4c28f408 PA |
339 | /* Use SIGKILL instead of PTRACE_KILL because the former works even |
340 | if the thread is running, while the later doesn't. */ | |
341 | kill (pid, SIGKILL); | |
56aac7e8 MS |
342 | ret = waitpid (pid, &status, 0); |
343 | /* We might get a SIGCHLD instead of an exit status. This is | |
344 | aggravated by the first kill above - a child has just | |
345 | died. MVS comment cut-and-pasted from linux-nat. */ | |
346 | } while (ret == pid && WIFSTOPPED (status)); | |
347 | } | |
348 | init_fork_list (); /* Clear list, prepare to start fresh. */ | |
ac264b3b MS |
349 | } |
350 | ||
351 | /* The current inferior_ptid has exited, but there are other viable | |
352 | forks to debug. Delete the exiting one and context-switch to the | |
353 | first available. */ | |
354 | ||
3cb5bea9 | 355 | void |
ac264b3b MS |
356 | linux_fork_mourn_inferior (void) |
357 | { | |
358 | /* Wait just one more time to collect the inferior's exit status. | |
359 | Do not check whether this succeeds though, since we may be | |
360 | dealing with a process that we attached to. Such a process will | |
361 | only report its exit status to its original parent. */ | |
362 | int status; | |
363 | ||
364 | waitpid (ptid_get_pid (inferior_ptid), &status, 0); | |
365 | ||
366 | /* OK, presumably inferior_ptid is the one who has exited. | |
367 | We need to delete that one from the fork_list, and switch | |
368 | to the next available fork. */ | |
369 | delete_fork (inferior_ptid); | |
791b663b DJ |
370 | |
371 | /* There should still be a fork - if there's only one left, | |
372 | delete_fork won't remove it, because we haven't updated | |
373 | inferior_ptid yet. */ | |
374 | gdb_assert (fork_list); | |
375 | ||
376 | fork_load_infrun_state (fork_list); | |
377 | printf_filtered (_("[Switching to %s]\n"), | |
378 | target_pid_to_str (inferior_ptid)); | |
379 | ||
380 | /* If there's only one fork, switch back to non-fork mode. */ | |
381 | if (fork_list->next == NULL) | |
382 | delete_fork (inferior_ptid); | |
ac264b3b MS |
383 | } |
384 | ||
7a7d3353 PA |
385 | /* The current inferior_ptid is being detached, but there are other |
386 | viable forks to debug. Detach and delete it and context-switch to | |
387 | the first available. */ | |
388 | ||
3cb5bea9 | 389 | void |
52554a0e | 390 | linux_fork_detach (const char *args, int from_tty) |
7a7d3353 PA |
391 | { |
392 | /* OK, inferior_ptid is the one we are detaching from. We need to | |
393 | delete it from the fork_list, and switch to the next available | |
394 | fork. */ | |
395 | ||
dfd4cc63 | 396 | if (ptrace (PTRACE_DETACH, ptid_get_pid (inferior_ptid), 0, 0)) |
7a7d3353 PA |
397 | error (_("Unable to detach %s"), target_pid_to_str (inferior_ptid)); |
398 | ||
399 | delete_fork (inferior_ptid); | |
7a7d3353 PA |
400 | |
401 | /* There should still be a fork - if there's only one left, | |
402 | delete_fork won't remove it, because we haven't updated | |
403 | inferior_ptid yet. */ | |
404 | gdb_assert (fork_list); | |
405 | ||
406 | fork_load_infrun_state (fork_list); | |
407 | ||
408 | if (from_tty) | |
409 | printf_filtered (_("[Switching to %s]\n"), | |
410 | target_pid_to_str (inferior_ptid)); | |
411 | ||
412 | /* If there's only one fork, switch back to non-fork mode. */ | |
413 | if (fork_list->next == NULL) | |
414 | delete_fork (inferior_ptid); | |
415 | } | |
416 | ||
7a298875 HZ |
417 | static void |
418 | inferior_call_waitpid_cleanup (void *fp) | |
419 | { | |
420 | struct fork_info *oldfp = fp; | |
421 | ||
e17c9e56 HZ |
422 | if (oldfp) |
423 | { | |
1777feb0 | 424 | /* Switch back to inferior_ptid. */ |
e17c9e56 HZ |
425 | remove_breakpoints (); |
426 | fork_load_infrun_state (oldfp); | |
427 | insert_breakpoints (); | |
428 | } | |
7a298875 HZ |
429 | } |
430 | ||
431 | static int | |
432 | inferior_call_waitpid (ptid_t pptid, int pid) | |
433 | { | |
434 | struct objfile *waitpid_objf; | |
435 | struct value *waitpid_fn = NULL; | |
e17c9e56 | 436 | struct value *argv[4], *retv; |
7a298875 HZ |
437 | struct gdbarch *gdbarch = get_current_arch (); |
438 | struct fork_info *oldfp = NULL, *newfp = NULL; | |
e17c9e56 | 439 | struct cleanup *old_cleanup; |
7a298875 HZ |
440 | int ret = -1; |
441 | ||
442 | if (!ptid_equal (pptid, inferior_ptid)) | |
443 | { | |
444 | /* Switch to pptid. */ | |
445 | oldfp = find_fork_ptid (inferior_ptid); | |
446 | gdb_assert (oldfp != NULL); | |
447 | newfp = find_fork_ptid (pptid); | |
da3ecdc6 | 448 | gdb_assert (newfp != NULL); |
7a298875 HZ |
449 | fork_save_infrun_state (oldfp, 1); |
450 | remove_breakpoints (); | |
451 | fork_load_infrun_state (newfp); | |
452 | insert_breakpoints (); | |
7a298875 HZ |
453 | } |
454 | ||
e17c9e56 HZ |
455 | old_cleanup = make_cleanup (inferior_call_waitpid_cleanup, oldfp); |
456 | ||
7a298875 HZ |
457 | /* Get the waitpid_fn. */ |
458 | if (lookup_minimal_symbol ("waitpid", NULL, NULL) != NULL) | |
459 | waitpid_fn = find_function_in_inferior ("waitpid", &waitpid_objf); | |
460 | if (!waitpid_fn && lookup_minimal_symbol ("_waitpid", NULL, NULL) != NULL) | |
461 | waitpid_fn = find_function_in_inferior ("_waitpid", &waitpid_objf); | |
462 | if (!waitpid_fn) | |
463 | goto out; | |
464 | ||
465 | /* Get the argv. */ | |
466 | argv[0] = value_from_longest (builtin_type (gdbarch)->builtin_int, pid); | |
467 | argv[1] = value_from_pointer (builtin_type (gdbarch)->builtin_data_ptr, 0); | |
468 | argv[2] = value_from_longest (builtin_type (gdbarch)->builtin_int, 0); | |
469 | argv[3] = 0; | |
470 | ||
e17c9e56 HZ |
471 | retv = call_function_by_hand (waitpid_fn, 3, argv); |
472 | if (value_as_long (retv) < 0) | |
473 | goto out; | |
7a298875 HZ |
474 | |
475 | ret = 0; | |
476 | ||
477 | out: | |
e17c9e56 | 478 | do_cleanups (old_cleanup); |
7a298875 HZ |
479 | return ret; |
480 | } | |
481 | ||
ac264b3b MS |
482 | /* Fork list <-> user interface. */ |
483 | ||
484 | static void | |
3cb5bea9 | 485 | delete_checkpoint_command (char *args, int from_tty) |
ac264b3b | 486 | { |
e17c9e56 | 487 | ptid_t ptid, pptid; |
7a298875 | 488 | struct fork_info *fi; |
ac264b3b MS |
489 | |
490 | if (!args || !*args) | |
2277426b | 491 | error (_("Requires argument (checkpoint id to delete)")); |
ac264b3b MS |
492 | |
493 | ptid = fork_id_to_ptid (parse_and_eval_long (args)); | |
494 | if (ptid_equal (ptid, minus_one_ptid)) | |
2277426b | 495 | error (_("No such checkpoint id, %s"), args); |
ac264b3b MS |
496 | |
497 | if (ptid_equal (ptid, inferior_ptid)) | |
3cb5bea9 PA |
498 | error (_("\ |
499 | Please switch to another checkpoint before deleting the current one")); | |
ac264b3b | 500 | |
dfd4cc63 | 501 | if (ptrace (PTRACE_KILL, ptid_get_pid (ptid), 0, 0)) |
54ba13f7 | 502 | error (_("Unable to kill pid %s"), target_pid_to_str (ptid)); |
ac264b3b | 503 | |
7a298875 HZ |
504 | fi = find_fork_ptid (ptid); |
505 | gdb_assert (fi); | |
e17c9e56 | 506 | pptid = fi->parent_ptid; |
7a298875 | 507 | |
ac264b3b MS |
508 | if (from_tty) |
509 | printf_filtered (_("Killed %s\n"), target_pid_to_str (ptid)); | |
510 | ||
511 | delete_fork (ptid); | |
7a298875 HZ |
512 | |
513 | /* If fi->parent_ptid is not a part of lwp but it's a part of checkpoint | |
514 | list, waitpid the ptid. | |
515 | If fi->parent_ptid is a part of lwp and it is stoped, waitpid the | |
516 | ptid. */ | |
e17c9e56 HZ |
517 | if ((!find_thread_ptid (pptid) && find_fork_ptid (pptid)) |
518 | || (find_thread_ptid (pptid) && is_stopped (pptid))) | |
7a298875 | 519 | { |
dfd4cc63 | 520 | if (inferior_call_waitpid (pptid, ptid_get_pid (ptid))) |
7a298875 HZ |
521 | warning (_("Unable to wait pid %s"), target_pid_to_str (ptid)); |
522 | } | |
ac264b3b MS |
523 | } |
524 | ||
525 | static void | |
3cb5bea9 | 526 | detach_checkpoint_command (char *args, int from_tty) |
ac264b3b MS |
527 | { |
528 | ptid_t ptid; | |
529 | ||
530 | if (!args || !*args) | |
2277426b | 531 | error (_("Requires argument (checkpoint id to detach)")); |
ac264b3b MS |
532 | |
533 | ptid = fork_id_to_ptid (parse_and_eval_long (args)); | |
534 | if (ptid_equal (ptid, minus_one_ptid)) | |
2277426b | 535 | error (_("No such checkpoint id, %s"), args); |
ac264b3b MS |
536 | |
537 | if (ptid_equal (ptid, inferior_ptid)) | |
2277426b PA |
538 | error (_("\ |
539 | Please switch to another checkpoint before detaching the current one")); | |
ac264b3b | 540 | |
dfd4cc63 | 541 | if (ptrace (PTRACE_DETACH, ptid_get_pid (ptid), 0, 0)) |
ac264b3b MS |
542 | error (_("Unable to detach %s"), target_pid_to_str (ptid)); |
543 | ||
544 | if (from_tty) | |
545 | printf_filtered (_("Detached %s\n"), target_pid_to_str (ptid)); | |
546 | ||
547 | delete_fork (ptid); | |
548 | } | |
549 | ||
3cb5bea9 | 550 | /* Print information about currently known checkpoints. */ |
ac264b3b MS |
551 | |
552 | static void | |
3cb5bea9 | 553 | info_checkpoints_command (char *arg, int from_tty) |
ac264b3b | 554 | { |
5af949e3 | 555 | struct gdbarch *gdbarch = get_current_arch (); |
ac264b3b | 556 | struct symtab_and_line sal; |
ac264b3b | 557 | struct fork_info *fp; |
ac264b3b | 558 | ULONGEST pc; |
b8db102d MS |
559 | int requested = -1; |
560 | struct fork_info *printed = NULL; | |
561 | ||
562 | if (arg && *arg) | |
563 | requested = (int) parse_and_eval_long (arg); | |
ac264b3b MS |
564 | |
565 | for (fp = fork_list; fp; fp = fp->next) | |
566 | { | |
b8db102d MS |
567 | if (requested > 0 && fp->num != requested) |
568 | continue; | |
569 | ||
570 | printed = fp; | |
ac264b3b MS |
571 | if (ptid_equal (fp->ptid, inferior_ptid)) |
572 | { | |
573 | printf_filtered ("* "); | |
fb14de7b | 574 | pc = regcache_read_pc (get_current_regcache ()); |
ac264b3b MS |
575 | } |
576 | else | |
577 | { | |
578 | printf_filtered (" "); | |
2277426b | 579 | pc = regcache_read_pc (fp->savedregs); |
ac264b3b MS |
580 | } |
581 | printf_filtered ("%d %s", fp->num, target_pid_to_str (fp->ptid)); | |
582 | if (fp->num == 0) | |
583 | printf_filtered (_(" (main process)")); | |
584 | printf_filtered (_(" at ")); | |
5af949e3 | 585 | fputs_filtered (paddress (gdbarch, pc), gdb_stdout); |
ac264b3b MS |
586 | |
587 | sal = find_pc_line (pc, 0); | |
588 | if (sal.symtab) | |
05cba821 JK |
589 | printf_filtered (_(", file %s"), |
590 | symtab_to_filename_for_display (sal.symtab)); | |
ac264b3b MS |
591 | if (sal.line) |
592 | printf_filtered (_(", line %d"), sal.line); | |
593 | if (!sal.symtab && !sal.line) | |
594 | { | |
7cbd4a93 | 595 | struct bound_minimal_symbol msym; |
ac264b3b MS |
596 | |
597 | msym = lookup_minimal_symbol_by_pc (pc); | |
7cbd4a93 TT |
598 | if (msym.minsym) |
599 | printf_filtered (", <%s>", SYMBOL_LINKAGE_NAME (msym.minsym)); | |
ac264b3b MS |
600 | } |
601 | ||
602 | putchar_filtered ('\n'); | |
603 | } | |
b8db102d MS |
604 | if (printed == NULL) |
605 | { | |
606 | if (requested > 0) | |
2277426b | 607 | printf_filtered (_("No checkpoint number %d.\n"), requested); |
b8db102d | 608 | else |
2277426b | 609 | printf_filtered (_("No checkpoints.\n")); |
b8db102d | 610 | } |
ac264b3b MS |
611 | } |
612 | ||
2277426b PA |
613 | /* The PID of the process we're checkpointing. */ |
614 | static int checkpointing_pid = 0; | |
ac264b3b | 615 | |
2277426b PA |
616 | int |
617 | linux_fork_checkpointing_p (int pid) | |
ac264b3b | 618 | { |
2277426b | 619 | return (checkpointing_pid == pid); |
ac264b3b MS |
620 | } |
621 | ||
92f6badc KP |
622 | /* Callback for iterate over threads. Used to check whether |
623 | the current inferior is multi-threaded. Returns true as soon | |
624 | as it sees the second thread of the current inferior. */ | |
625 | ||
626 | static int | |
627 | inf_has_multiple_thread_cb (struct thread_info *tp, void *data) | |
628 | { | |
629 | int *count_p = (int *) data; | |
630 | ||
631 | if (current_inferior ()->pid == ptid_get_pid (tp->ptid)) | |
632 | (*count_p)++; | |
633 | ||
634 | /* Stop the iteration if multiple threads have been detected. */ | |
635 | return *count_p > 1; | |
636 | } | |
637 | ||
638 | /* Return true if the current inferior is multi-threaded. */ | |
639 | ||
640 | static int | |
641 | inf_has_multiple_threads (void) | |
642 | { | |
643 | int count = 0; | |
644 | ||
645 | iterate_over_threads (inf_has_multiple_thread_cb, &count); | |
646 | return (count > 1); | |
647 | } | |
648 | ||
ac264b3b MS |
649 | static void |
650 | checkpoint_command (char *args, int from_tty) | |
651 | { | |
3e3b026f UW |
652 | struct objfile *fork_objf; |
653 | struct gdbarch *gdbarch; | |
ac264b3b MS |
654 | struct target_waitstatus last_target_waitstatus; |
655 | ptid_t last_target_ptid; | |
656 | struct value *fork_fn = NULL, *ret; | |
657 | struct fork_info *fp; | |
658 | pid_t retpid; | |
659 | struct cleanup *old_chain; | |
74960c60 | 660 | |
92f6badc KP |
661 | if (!target_has_execution) |
662 | error (_("The program is not being run.")); | |
663 | ||
664 | /* Ensure that the inferior is not multithreaded. */ | |
665 | update_thread_list (); | |
666 | if (inf_has_multiple_threads ()) | |
667 | error (_("checkpoint: can't checkpoint multiple threads.")); | |
668 | ||
ac264b3b MS |
669 | /* Make the inferior fork, record its (and gdb's) state. */ |
670 | ||
671 | if (lookup_minimal_symbol ("fork", NULL, NULL) != NULL) | |
3e3b026f | 672 | fork_fn = find_function_in_inferior ("fork", &fork_objf); |
ac264b3b MS |
673 | if (!fork_fn) |
674 | if (lookup_minimal_symbol ("_fork", NULL, NULL) != NULL) | |
3e3b026f | 675 | fork_fn = find_function_in_inferior ("fork", &fork_objf); |
ac264b3b MS |
676 | if (!fork_fn) |
677 | error (_("checkpoint: can't find fork function in inferior.")); | |
678 | ||
3e3b026f UW |
679 | gdbarch = get_objfile_arch (fork_objf); |
680 | ret = value_from_longest (builtin_type (gdbarch)->builtin_int, 0); | |
2277426b PA |
681 | |
682 | /* Tell linux-nat.c that we're checkpointing this inferior. */ | |
683 | old_chain = make_cleanup_restore_integer (&checkpointing_pid); | |
dfd4cc63 | 684 | checkpointing_pid = ptid_get_pid (inferior_ptid); |
2277426b | 685 | |
ac264b3b MS |
686 | ret = call_function_by_hand (fork_fn, 0, &ret); |
687 | do_cleanups (old_chain); | |
688 | if (!ret) /* Probably can't happen. */ | |
689 | error (_("checkpoint: call_function_by_hand returned null.")); | |
690 | ||
691 | retpid = value_as_long (ret); | |
692 | get_last_target_status (&last_target_ptid, &last_target_waitstatus); | |
693 | if (from_tty) | |
694 | { | |
695 | int parent_pid; | |
696 | ||
3cb5bea9 | 697 | printf_filtered (_("checkpoint: fork returned pid %ld.\n"), |
ac264b3b MS |
698 | (long) retpid); |
699 | if (info_verbose) | |
700 | { | |
701 | parent_pid = ptid_get_lwp (last_target_ptid); | |
702 | if (parent_pid == 0) | |
703 | parent_pid = ptid_get_pid (last_target_ptid); | |
3cb5bea9 | 704 | printf_filtered (_(" gdb says parent = %ld.\n"), |
ac264b3b MS |
705 | (long) parent_pid); |
706 | } | |
707 | } | |
708 | ||
709 | fp = find_fork_pid (retpid); | |
710 | if (!fp) | |
711 | error (_("Failed to find new fork")); | |
712 | fork_save_infrun_state (fp, 1); | |
7a298875 | 713 | fp->parent_ptid = last_target_ptid; |
ac264b3b MS |
714 | } |
715 | ||
716 | static void | |
717 | linux_fork_context (struct fork_info *newfp, int from_tty) | |
718 | { | |
719 | /* Now we attempt to switch processes. */ | |
0d14fc63 | 720 | struct fork_info *oldfp; |
ac264b3b | 721 | |
0d14fc63 | 722 | gdb_assert (newfp != NULL); |
ac264b3b | 723 | |
0d14fc63 PA |
724 | oldfp = find_fork_ptid (inferior_ptid); |
725 | gdb_assert (oldfp != NULL); | |
ac264b3b MS |
726 | |
727 | fork_save_infrun_state (oldfp, 1); | |
74960c60 | 728 | remove_breakpoints (); |
ac264b3b | 729 | fork_load_infrun_state (newfp); |
74960c60 | 730 | insert_breakpoints (); |
ac264b3b | 731 | |
3cb5bea9 | 732 | printf_filtered (_("Switching to %s\n"), |
ac264b3b MS |
733 | target_pid_to_str (inferior_ptid)); |
734 | ||
08d72866 | 735 | print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC, 1); |
ac264b3b MS |
736 | } |
737 | ||
2277426b | 738 | /* Switch inferior process (checkpoint) context, by checkpoint id. */ |
ac264b3b MS |
739 | static void |
740 | restart_command (char *args, int from_tty) | |
741 | { | |
742 | struct fork_info *fp; | |
743 | ||
744 | if (!args || !*args) | |
745 | error (_("Requires argument (checkpoint id to restart)")); | |
746 | ||
747 | if ((fp = find_fork_id (parse_and_eval_long (args))) == NULL) | |
748 | error (_("Not found: checkpoint id %s"), args); | |
749 | ||
750 | linux_fork_context (fp, from_tty); | |
751 | } | |
752 | ||
753 | void | |
754 | _initialize_linux_fork (void) | |
755 | { | |
756 | init_fork_list (); | |
757 | ||
ac264b3b MS |
758 | /* Checkpoint command: create a fork of the inferior process |
759 | and set it aside for later debugging. */ | |
760 | ||
761 | add_com ("checkpoint", class_obscure, checkpoint_command, _("\ | |
762 | Fork a duplicate process (experimental).")); | |
763 | ||
2277426b PA |
764 | /* Restart command: restore the context of a specified checkpoint |
765 | process. */ | |
ac264b3b MS |
766 | |
767 | add_com ("restart", class_obscure, restart_command, _("\ | |
768 | restart <n>: restore program context from a checkpoint.\n\ | |
769 | Argument 'n' is checkpoint ID, as displayed by 'info checkpoints'.")); | |
770 | ||
b8db102d | 771 | /* Delete checkpoint command: kill the process and remove it from |
3cb5bea9 | 772 | the fork list. */ |
ac264b3b | 773 | |
3cb5bea9 | 774 | add_cmd ("checkpoint", class_obscure, delete_checkpoint_command, _("\ |
2277426b | 775 | Delete a checkpoint (experimental)."), |
b8db102d | 776 | &deletelist); |
ac264b3b | 777 | |
3cb5bea9 | 778 | /* Detach checkpoint command: release the process to run independently, |
ac264b3b MS |
779 | and remove it from the fork list. */ |
780 | ||
3cb5bea9 | 781 | add_cmd ("checkpoint", class_obscure, detach_checkpoint_command, _("\ |
2277426b | 782 | Detach from a checkpoint (experimental)."), |
f73adfeb | 783 | &detachlist); |
ac264b3b | 784 | |
3cb5bea9 | 785 | /* Info checkpoints command: list all forks/checkpoints |
ac264b3b MS |
786 | currently under gdb's control. */ |
787 | ||
3cb5bea9 | 788 | add_info ("checkpoints", info_checkpoints_command, |
2277426b | 789 | _("IDs of currently known checkpoints.")); |
ac264b3b | 790 | } |