Commit | Line | Data |
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ac264b3b MS |
1 | /* GNU/Linux native-dependent code for debugging multiple forks. |
2 | ||
ecd75fc8 | 3 | Copyright (C) 2005-2014 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 | 22 | #include "inferior.h" |
45741a9c | 23 | #include "infrun.h" |
ac264b3b MS |
24 | #include "regcache.h" |
25 | #include "gdbcmd.h" | |
26 | #include "infcall.h" | |
3e3b026f | 27 | #include "objfiles.h" |
791b663b | 28 | #include "gdb_assert.h" |
0e9f083f | 29 | #include <string.h> |
ac264b3b | 30 | #include "linux-fork.h" |
f973ed9c | 31 | #include "linux-nat.h" |
7a298875 | 32 | #include "gdbthread.h" |
05cba821 | 33 | #include "source.h" |
ac264b3b MS |
34 | |
35 | #include <sys/ptrace.h> | |
3c61c145 | 36 | #include "gdb_wait.h" |
2978b111 | 37 | #include <dirent.h> |
ac264b3b MS |
38 | #include <ctype.h> |
39 | ||
40 | struct fork_info *fork_list; | |
41 | static int highest_fork_num; | |
42 | ||
43 | /* Prevent warning from -Wmissing-prototypes. */ | |
44 | extern void _initialize_linux_fork (void); | |
45 | ||
ac264b3b MS |
46 | /* Fork list data structure: */ |
47 | struct fork_info | |
48 | { | |
49 | struct fork_info *next; | |
50 | ptid_t ptid; | |
7a298875 | 51 | ptid_t parent_ptid; |
1777feb0 | 52 | int num; /* Convenient handle (GDB fork id). */ |
3cb5bea9 | 53 | struct regcache *savedregs; /* Convenient for info fork, saves |
ac264b3b MS |
54 | having to actually switch contexts. */ |
55 | int clobber_regs; /* True if we should restore saved regs. */ | |
ac264b3b MS |
56 | off_t *filepos; /* Set of open file descriptors' offsets. */ |
57 | int maxfd; | |
58 | }; | |
59 | ||
60 | /* Fork list methods: */ | |
61 | ||
3cb5bea9 | 62 | int |
ac264b3b MS |
63 | forks_exist_p (void) |
64 | { | |
65 | return (fork_list != NULL); | |
66 | } | |
67 | ||
3cb5bea9 | 68 | /* Add a fork to the internal fork list. */ |
ac264b3b | 69 | |
3cb5bea9 | 70 | struct fork_info * |
ac264b3b MS |
71 | add_fork (pid_t pid) |
72 | { | |
73 | struct fork_info *fp; | |
74 | ||
dfd4cc63 | 75 | if (fork_list == NULL && pid != ptid_get_pid (inferior_ptid)) |
ac264b3b MS |
76 | { |
77 | /* Special case -- if this is the first fork in the list | |
78 | (the list is hitherto empty), and if this new fork is | |
79 | NOT the current inferior_ptid, then add inferior_ptid | |
80 | first, as a special zeroeth fork id. */ | |
81 | highest_fork_num = -1; | |
dfd4cc63 | 82 | add_fork (ptid_get_pid (inferior_ptid)); /* safe recursion */ |
ac264b3b MS |
83 | } |
84 | ||
41bf6aca | 85 | fp = XCNEW (struct fork_info); |
f973ed9c | 86 | fp->ptid = ptid_build (pid, pid, 0); |
ac264b3b MS |
87 | fp->num = ++highest_fork_num; |
88 | fp->next = fork_list; | |
89 | fork_list = fp; | |
90 | return fp; | |
91 | } | |
92 | ||
93 | static void | |
94 | free_fork (struct fork_info *fp) | |
95 | { | |
96 | /* Notes on step-resume breakpoints: since this is a concern for | |
97 | threads, let's convince ourselves that it's not a concern for | |
98 | forks. There are two ways for a fork_info to be created. First, | |
99 | by the checkpoint command, in which case we're at a gdb prompt | |
100 | and there can't be any step-resume breakpoint. Second, by a fork | |
101 | in the user program, in which case we *may* have stepped into the | |
102 | fork call, but regardless of whether we follow the parent or the | |
103 | child, we will return to the same place and the step-resume | |
104 | breakpoint, if any, will take care of itself as usual. And | |
105 | unlike threads, we do not save a private copy of the step-resume | |
106 | breakpoint -- so we're OK. */ | |
107 | ||
108 | if (fp) | |
109 | { | |
110 | if (fp->savedregs) | |
111 | regcache_xfree (fp->savedregs); | |
112 | if (fp->filepos) | |
113 | xfree (fp->filepos); | |
114 | xfree (fp); | |
115 | } | |
116 | } | |
117 | ||
118 | static void | |
119 | delete_fork (ptid_t ptid) | |
120 | { | |
121 | struct fork_info *fp, *fpprev; | |
122 | ||
123 | fpprev = NULL; | |
124 | ||
26cb8b7c PA |
125 | linux_nat_forget_process (ptid_get_pid (ptid)); |
126 | ||
ac264b3b MS |
127 | for (fp = fork_list; fp; fpprev = fp, fp = fp->next) |
128 | if (ptid_equal (fp->ptid, ptid)) | |
129 | break; | |
130 | ||
131 | if (!fp) | |
132 | return; | |
133 | ||
134 | if (fpprev) | |
135 | fpprev->next = fp->next; | |
136 | else | |
137 | fork_list = fp->next; | |
138 | ||
139 | free_fork (fp); | |
140 | ||
3cb5bea9 | 141 | /* Special case: if there is now only one process in the list, |
ac264b3b MS |
142 | and if it is (hopefully!) the current inferior_ptid, then |
143 | remove it, leaving the list empty -- we're now down to the | |
144 | default case of debugging a single process. */ | |
145 | if (fork_list != NULL && fork_list->next == NULL && | |
146 | ptid_equal (fork_list->ptid, inferior_ptid)) | |
147 | { | |
148 | /* Last fork -- delete from list and handle as solo process | |
149 | (should be a safe recursion). */ | |
150 | delete_fork (inferior_ptid); | |
151 | } | |
152 | } | |
153 | ||
154 | /* Find a fork_info by matching PTID. */ | |
155 | static struct fork_info * | |
156 | find_fork_ptid (ptid_t ptid) | |
157 | { | |
158 | struct fork_info *fp; | |
159 | ||
160 | for (fp = fork_list; fp; fp = fp->next) | |
161 | if (ptid_equal (fp->ptid, ptid)) | |
162 | return fp; | |
163 | ||
164 | return NULL; | |
165 | } | |
166 | ||
167 | /* Find a fork_info by matching ID. */ | |
168 | static struct fork_info * | |
169 | find_fork_id (int num) | |
170 | { | |
171 | struct fork_info *fp; | |
172 | ||
173 | for (fp = fork_list; fp; fp = fp->next) | |
174 | if (fp->num == num) | |
175 | return fp; | |
176 | ||
177 | return NULL; | |
178 | } | |
179 | ||
180 | /* Find a fork_info by matching pid. */ | |
181 | extern struct fork_info * | |
182 | find_fork_pid (pid_t pid) | |
183 | { | |
184 | struct fork_info *fp; | |
185 | ||
186 | for (fp = fork_list; fp; fp = fp->next) | |
187 | if (pid == ptid_get_pid (fp->ptid)) | |
188 | return fp; | |
189 | ||
190 | return NULL; | |
191 | } | |
192 | ||
193 | static ptid_t | |
194 | fork_id_to_ptid (int num) | |
195 | { | |
196 | struct fork_info *fork = find_fork_id (num); | |
197 | if (fork) | |
198 | return fork->ptid; | |
199 | else | |
200 | return pid_to_ptid (-1); | |
201 | } | |
202 | ||
203 | static void | |
204 | init_fork_list (void) | |
205 | { | |
206 | struct fork_info *fp, *fpnext; | |
207 | ||
208 | if (!fork_list) | |
209 | return; | |
210 | ||
211 | for (fp = fork_list; fp; fp = fpnext) | |
212 | { | |
213 | fpnext = fp->next; | |
214 | free_fork (fp); | |
215 | } | |
216 | ||
217 | fork_list = NULL; | |
218 | } | |
219 | ||
220 | /* Fork list <-> gdb interface. */ | |
221 | ||
3cb5bea9 | 222 | /* Utility function for fork_load/fork_save. |
ac264b3b MS |
223 | Calls lseek in the (current) inferior process. */ |
224 | ||
225 | static off_t | |
226 | call_lseek (int fd, off_t offset, int whence) | |
227 | { | |
228 | char exp[80]; | |
229 | ||
230 | snprintf (&exp[0], sizeof (exp), "lseek (%d, %ld, %d)", | |
231 | fd, (long) offset, whence); | |
232 | return (off_t) parse_and_eval_long (&exp[0]); | |
233 | } | |
234 | ||
235 | /* Load infrun state for the fork PTID. */ | |
236 | ||
237 | static void | |
238 | fork_load_infrun_state (struct fork_info *fp) | |
239 | { | |
240 | extern void nullify_last_target_wait_ptid (); | |
241 | int i; | |
242 | ||
2277426b | 243 | linux_nat_switch_fork (fp->ptid); |
f973ed9c | 244 | |
ac264b3b | 245 | if (fp->savedregs && fp->clobber_regs) |
594f7785 | 246 | regcache_cpy (get_current_regcache (), fp->savedregs); |
ac264b3b | 247 | |
791b663b DJ |
248 | registers_changed (); |
249 | reinit_frame_cache (); | |
250 | ||
fb14de7b | 251 | stop_pc = regcache_read_pc (get_current_regcache ()); |
ac264b3b MS |
252 | nullify_last_target_wait_ptid (); |
253 | ||
254 | /* Now restore the file positions of open file descriptors. */ | |
255 | if (fp->filepos) | |
256 | { | |
257 | for (i = 0; i <= fp->maxfd; i++) | |
258 | if (fp->filepos[i] != (off_t) -1) | |
259 | call_lseek (i, fp->filepos[i], SEEK_SET); | |
260 | /* NOTE: I can get away with using SEEK_SET and SEEK_CUR because | |
261 | this is native-only. If it ever has to be cross, we'll have | |
262 | to rethink this. */ | |
263 | } | |
264 | } | |
265 | ||
266 | /* Save infrun state for the fork PTID. | |
267 | Exported for use by linux child_follow_fork. */ | |
268 | ||
2277426b | 269 | static void |
ac264b3b MS |
270 | fork_save_infrun_state (struct fork_info *fp, int clobber_regs) |
271 | { | |
d8d2a3ee | 272 | char path[PATH_MAX]; |
ac264b3b MS |
273 | struct dirent *de; |
274 | DIR *d; | |
275 | ||
276 | if (fp->savedregs) | |
277 | regcache_xfree (fp->savedregs); | |
278 | ||
594f7785 | 279 | fp->savedregs = regcache_dup (get_current_regcache ()); |
ac264b3b | 280 | fp->clobber_regs = clobber_regs; |
ac264b3b MS |
281 | |
282 | if (clobber_regs) | |
283 | { | |
284 | /* Now save the 'state' (file position) of all open file descriptors. | |
285 | Unfortunately fork does not take care of that for us... */ | |
dfd4cc63 LM |
286 | snprintf (path, PATH_MAX, "/proc/%ld/fd", |
287 | (long) ptid_get_pid (fp->ptid)); | |
ac264b3b MS |
288 | if ((d = opendir (path)) != NULL) |
289 | { | |
290 | long tmp; | |
291 | ||
292 | fp->maxfd = 0; | |
293 | while ((de = readdir (d)) != NULL) | |
294 | { | |
295 | /* Count open file descriptors (actually find highest | |
296 | numbered). */ | |
297 | tmp = strtol (&de->d_name[0], NULL, 10); | |
298 | if (fp->maxfd < tmp) | |
299 | fp->maxfd = tmp; | |
300 | } | |
301 | /* Allocate array of file positions. */ | |
3cb5bea9 | 302 | fp->filepos = xrealloc (fp->filepos, |
ac264b3b MS |
303 | (fp->maxfd + 1) * sizeof (*fp->filepos)); |
304 | ||
305 | /* Initialize to -1 (invalid). */ | |
306 | for (tmp = 0; tmp <= fp->maxfd; tmp++) | |
307 | fp->filepos[tmp] = -1; | |
308 | ||
309 | /* Now find actual file positions. */ | |
310 | rewinddir (d); | |
311 | while ((de = readdir (d)) != NULL) | |
312 | if (isdigit (de->d_name[0])) | |
313 | { | |
314 | tmp = strtol (&de->d_name[0], NULL, 10); | |
315 | fp->filepos[tmp] = call_lseek (tmp, 0, SEEK_CUR); | |
316 | } | |
317 | closedir (d); | |
318 | } | |
319 | } | |
320 | } | |
321 | ||
322 | /* Kill 'em all, let God sort 'em out... */ | |
323 | ||
3cb5bea9 | 324 | void |
ac264b3b MS |
325 | linux_fork_killall (void) |
326 | { | |
327 | /* Walk list and kill every pid. No need to treat the | |
328 | current inferior_ptid as special (we do not return a | |
329 | status for it) -- however any process may be a child | |
330 | or a parent, so may get a SIGCHLD from a previously | |
331 | killed child. Wait them all out. */ | |
56aac7e8 | 332 | struct fork_info *fp; |
ac264b3b MS |
333 | pid_t pid, ret; |
334 | int status; | |
335 | ||
56aac7e8 MS |
336 | for (fp = fork_list; fp; fp = fp->next) |
337 | { | |
dfd4cc63 | 338 | pid = ptid_get_pid (fp->ptid); |
56aac7e8 | 339 | do { |
4c28f408 PA |
340 | /* Use SIGKILL instead of PTRACE_KILL because the former works even |
341 | if the thread is running, while the later doesn't. */ | |
342 | kill (pid, SIGKILL); | |
56aac7e8 MS |
343 | ret = waitpid (pid, &status, 0); |
344 | /* We might get a SIGCHLD instead of an exit status. This is | |
345 | aggravated by the first kill above - a child has just | |
346 | died. MVS comment cut-and-pasted from linux-nat. */ | |
347 | } while (ret == pid && WIFSTOPPED (status)); | |
348 | } | |
349 | init_fork_list (); /* Clear list, prepare to start fresh. */ | |
ac264b3b MS |
350 | } |
351 | ||
352 | /* The current inferior_ptid has exited, but there are other viable | |
353 | forks to debug. Delete the exiting one and context-switch to the | |
354 | first available. */ | |
355 | ||
3cb5bea9 | 356 | void |
ac264b3b MS |
357 | linux_fork_mourn_inferior (void) |
358 | { | |
359 | /* Wait just one more time to collect the inferior's exit status. | |
360 | Do not check whether this succeeds though, since we may be | |
361 | dealing with a process that we attached to. Such a process will | |
362 | only report its exit status to its original parent. */ | |
363 | int status; | |
364 | ||
365 | waitpid (ptid_get_pid (inferior_ptid), &status, 0); | |
366 | ||
367 | /* OK, presumably inferior_ptid is the one who has exited. | |
368 | We need to delete that one from the fork_list, and switch | |
369 | to the next available fork. */ | |
370 | delete_fork (inferior_ptid); | |
791b663b DJ |
371 | |
372 | /* There should still be a fork - if there's only one left, | |
373 | delete_fork won't remove it, because we haven't updated | |
374 | inferior_ptid yet. */ | |
375 | gdb_assert (fork_list); | |
376 | ||
377 | fork_load_infrun_state (fork_list); | |
378 | printf_filtered (_("[Switching to %s]\n"), | |
379 | target_pid_to_str (inferior_ptid)); | |
380 | ||
381 | /* If there's only one fork, switch back to non-fork mode. */ | |
382 | if (fork_list->next == NULL) | |
383 | delete_fork (inferior_ptid); | |
ac264b3b MS |
384 | } |
385 | ||
7a7d3353 PA |
386 | /* The current inferior_ptid is being detached, but there are other |
387 | viable forks to debug. Detach and delete it and context-switch to | |
388 | the first available. */ | |
389 | ||
3cb5bea9 | 390 | void |
52554a0e | 391 | linux_fork_detach (const char *args, int from_tty) |
7a7d3353 PA |
392 | { |
393 | /* OK, inferior_ptid is the one we are detaching from. We need to | |
394 | delete it from the fork_list, and switch to the next available | |
395 | fork. */ | |
396 | ||
dfd4cc63 | 397 | if (ptrace (PTRACE_DETACH, ptid_get_pid (inferior_ptid), 0, 0)) |
7a7d3353 PA |
398 | error (_("Unable to detach %s"), target_pid_to_str (inferior_ptid)); |
399 | ||
400 | delete_fork (inferior_ptid); | |
7a7d3353 PA |
401 | |
402 | /* There should still be a fork - if there's only one left, | |
403 | delete_fork won't remove it, because we haven't updated | |
404 | inferior_ptid yet. */ | |
405 | gdb_assert (fork_list); | |
406 | ||
407 | fork_load_infrun_state (fork_list); | |
408 | ||
409 | if (from_tty) | |
410 | printf_filtered (_("[Switching to %s]\n"), | |
411 | target_pid_to_str (inferior_ptid)); | |
412 | ||
413 | /* If there's only one fork, switch back to non-fork mode. */ | |
414 | if (fork_list->next == NULL) | |
415 | delete_fork (inferior_ptid); | |
416 | } | |
417 | ||
7a298875 HZ |
418 | static void |
419 | inferior_call_waitpid_cleanup (void *fp) | |
420 | { | |
421 | struct fork_info *oldfp = fp; | |
422 | ||
e17c9e56 HZ |
423 | if (oldfp) |
424 | { | |
1777feb0 | 425 | /* Switch back to inferior_ptid. */ |
e17c9e56 HZ |
426 | remove_breakpoints (); |
427 | fork_load_infrun_state (oldfp); | |
428 | insert_breakpoints (); | |
429 | } | |
7a298875 HZ |
430 | } |
431 | ||
432 | static int | |
433 | inferior_call_waitpid (ptid_t pptid, int pid) | |
434 | { | |
435 | struct objfile *waitpid_objf; | |
436 | struct value *waitpid_fn = NULL; | |
e17c9e56 | 437 | struct value *argv[4], *retv; |
7a298875 HZ |
438 | struct gdbarch *gdbarch = get_current_arch (); |
439 | struct fork_info *oldfp = NULL, *newfp = NULL; | |
e17c9e56 | 440 | struct cleanup *old_cleanup; |
7a298875 HZ |
441 | int ret = -1; |
442 | ||
443 | if (!ptid_equal (pptid, inferior_ptid)) | |
444 | { | |
445 | /* Switch to pptid. */ | |
446 | oldfp = find_fork_ptid (inferior_ptid); | |
447 | gdb_assert (oldfp != NULL); | |
448 | newfp = find_fork_ptid (pptid); | |
da3ecdc6 | 449 | gdb_assert (newfp != NULL); |
7a298875 HZ |
450 | fork_save_infrun_state (oldfp, 1); |
451 | remove_breakpoints (); | |
452 | fork_load_infrun_state (newfp); | |
453 | insert_breakpoints (); | |
7a298875 HZ |
454 | } |
455 | ||
e17c9e56 HZ |
456 | old_cleanup = make_cleanup (inferior_call_waitpid_cleanup, oldfp); |
457 | ||
7a298875 | 458 | /* Get the waitpid_fn. */ |
3b7344d5 | 459 | if (lookup_minimal_symbol ("waitpid", NULL, NULL).minsym != NULL) |
7a298875 | 460 | waitpid_fn = find_function_in_inferior ("waitpid", &waitpid_objf); |
3b7344d5 TT |
461 | if (!waitpid_fn |
462 | && lookup_minimal_symbol ("_waitpid", NULL, NULL).minsym != NULL) | |
7a298875 HZ |
463 | waitpid_fn = find_function_in_inferior ("_waitpid", &waitpid_objf); |
464 | if (!waitpid_fn) | |
465 | goto out; | |
466 | ||
467 | /* Get the argv. */ | |
468 | argv[0] = value_from_longest (builtin_type (gdbarch)->builtin_int, pid); | |
469 | argv[1] = value_from_pointer (builtin_type (gdbarch)->builtin_data_ptr, 0); | |
470 | argv[2] = value_from_longest (builtin_type (gdbarch)->builtin_int, 0); | |
471 | argv[3] = 0; | |
472 | ||
e17c9e56 HZ |
473 | retv = call_function_by_hand (waitpid_fn, 3, argv); |
474 | if (value_as_long (retv) < 0) | |
475 | goto out; | |
7a298875 HZ |
476 | |
477 | ret = 0; | |
478 | ||
479 | out: | |
e17c9e56 | 480 | do_cleanups (old_cleanup); |
7a298875 HZ |
481 | return ret; |
482 | } | |
483 | ||
ac264b3b MS |
484 | /* Fork list <-> user interface. */ |
485 | ||
486 | static void | |
3cb5bea9 | 487 | delete_checkpoint_command (char *args, int from_tty) |
ac264b3b | 488 | { |
e17c9e56 | 489 | ptid_t ptid, pptid; |
7a298875 | 490 | struct fork_info *fi; |
ac264b3b MS |
491 | |
492 | if (!args || !*args) | |
2277426b | 493 | error (_("Requires argument (checkpoint id to delete)")); |
ac264b3b MS |
494 | |
495 | ptid = fork_id_to_ptid (parse_and_eval_long (args)); | |
496 | if (ptid_equal (ptid, minus_one_ptid)) | |
2277426b | 497 | error (_("No such checkpoint id, %s"), args); |
ac264b3b MS |
498 | |
499 | if (ptid_equal (ptid, inferior_ptid)) | |
3cb5bea9 PA |
500 | error (_("\ |
501 | Please switch to another checkpoint before deleting the current one")); | |
ac264b3b | 502 | |
dfd4cc63 | 503 | if (ptrace (PTRACE_KILL, ptid_get_pid (ptid), 0, 0)) |
54ba13f7 | 504 | error (_("Unable to kill pid %s"), target_pid_to_str (ptid)); |
ac264b3b | 505 | |
7a298875 HZ |
506 | fi = find_fork_ptid (ptid); |
507 | gdb_assert (fi); | |
e17c9e56 | 508 | pptid = fi->parent_ptid; |
7a298875 | 509 | |
ac264b3b MS |
510 | if (from_tty) |
511 | printf_filtered (_("Killed %s\n"), target_pid_to_str (ptid)); | |
512 | ||
513 | delete_fork (ptid); | |
7a298875 HZ |
514 | |
515 | /* If fi->parent_ptid is not a part of lwp but it's a part of checkpoint | |
516 | list, waitpid the ptid. | |
517 | If fi->parent_ptid is a part of lwp and it is stoped, waitpid the | |
518 | ptid. */ | |
e17c9e56 HZ |
519 | if ((!find_thread_ptid (pptid) && find_fork_ptid (pptid)) |
520 | || (find_thread_ptid (pptid) && is_stopped (pptid))) | |
7a298875 | 521 | { |
dfd4cc63 | 522 | if (inferior_call_waitpid (pptid, ptid_get_pid (ptid))) |
7a298875 HZ |
523 | warning (_("Unable to wait pid %s"), target_pid_to_str (ptid)); |
524 | } | |
ac264b3b MS |
525 | } |
526 | ||
527 | static void | |
3cb5bea9 | 528 | detach_checkpoint_command (char *args, int from_tty) |
ac264b3b MS |
529 | { |
530 | ptid_t ptid; | |
531 | ||
532 | if (!args || !*args) | |
2277426b | 533 | error (_("Requires argument (checkpoint id to detach)")); |
ac264b3b MS |
534 | |
535 | ptid = fork_id_to_ptid (parse_and_eval_long (args)); | |
536 | if (ptid_equal (ptid, minus_one_ptid)) | |
2277426b | 537 | error (_("No such checkpoint id, %s"), args); |
ac264b3b MS |
538 | |
539 | if (ptid_equal (ptid, inferior_ptid)) | |
2277426b PA |
540 | error (_("\ |
541 | Please switch to another checkpoint before detaching the current one")); | |
ac264b3b | 542 | |
dfd4cc63 | 543 | if (ptrace (PTRACE_DETACH, ptid_get_pid (ptid), 0, 0)) |
ac264b3b MS |
544 | error (_("Unable to detach %s"), target_pid_to_str (ptid)); |
545 | ||
546 | if (from_tty) | |
547 | printf_filtered (_("Detached %s\n"), target_pid_to_str (ptid)); | |
548 | ||
549 | delete_fork (ptid); | |
550 | } | |
551 | ||
3cb5bea9 | 552 | /* Print information about currently known checkpoints. */ |
ac264b3b MS |
553 | |
554 | static void | |
3cb5bea9 | 555 | info_checkpoints_command (char *arg, int from_tty) |
ac264b3b | 556 | { |
5af949e3 | 557 | struct gdbarch *gdbarch = get_current_arch (); |
ac264b3b | 558 | struct symtab_and_line sal; |
ac264b3b | 559 | struct fork_info *fp; |
ac264b3b | 560 | ULONGEST pc; |
b8db102d MS |
561 | int requested = -1; |
562 | struct fork_info *printed = NULL; | |
563 | ||
564 | if (arg && *arg) | |
565 | requested = (int) parse_and_eval_long (arg); | |
ac264b3b MS |
566 | |
567 | for (fp = fork_list; fp; fp = fp->next) | |
568 | { | |
b8db102d MS |
569 | if (requested > 0 && fp->num != requested) |
570 | continue; | |
571 | ||
572 | printed = fp; | |
ac264b3b MS |
573 | if (ptid_equal (fp->ptid, inferior_ptid)) |
574 | { | |
575 | printf_filtered ("* "); | |
fb14de7b | 576 | pc = regcache_read_pc (get_current_regcache ()); |
ac264b3b MS |
577 | } |
578 | else | |
579 | { | |
580 | printf_filtered (" "); | |
2277426b | 581 | pc = regcache_read_pc (fp->savedregs); |
ac264b3b MS |
582 | } |
583 | printf_filtered ("%d %s", fp->num, target_pid_to_str (fp->ptid)); | |
584 | if (fp->num == 0) | |
585 | printf_filtered (_(" (main process)")); | |
586 | printf_filtered (_(" at ")); | |
5af949e3 | 587 | fputs_filtered (paddress (gdbarch, pc), gdb_stdout); |
ac264b3b MS |
588 | |
589 | sal = find_pc_line (pc, 0); | |
590 | if (sal.symtab) | |
05cba821 JK |
591 | printf_filtered (_(", file %s"), |
592 | symtab_to_filename_for_display (sal.symtab)); | |
ac264b3b MS |
593 | if (sal.line) |
594 | printf_filtered (_(", line %d"), sal.line); | |
595 | if (!sal.symtab && !sal.line) | |
596 | { | |
7cbd4a93 | 597 | struct bound_minimal_symbol msym; |
ac264b3b MS |
598 | |
599 | msym = lookup_minimal_symbol_by_pc (pc); | |
7cbd4a93 | 600 | if (msym.minsym) |
efd66ac6 | 601 | printf_filtered (", <%s>", MSYMBOL_LINKAGE_NAME (msym.minsym)); |
ac264b3b MS |
602 | } |
603 | ||
604 | putchar_filtered ('\n'); | |
605 | } | |
b8db102d MS |
606 | if (printed == NULL) |
607 | { | |
608 | if (requested > 0) | |
2277426b | 609 | printf_filtered (_("No checkpoint number %d.\n"), requested); |
b8db102d | 610 | else |
2277426b | 611 | printf_filtered (_("No checkpoints.\n")); |
b8db102d | 612 | } |
ac264b3b MS |
613 | } |
614 | ||
2277426b PA |
615 | /* The PID of the process we're checkpointing. */ |
616 | static int checkpointing_pid = 0; | |
ac264b3b | 617 | |
2277426b PA |
618 | int |
619 | linux_fork_checkpointing_p (int pid) | |
ac264b3b | 620 | { |
2277426b | 621 | return (checkpointing_pid == pid); |
ac264b3b MS |
622 | } |
623 | ||
92f6badc KP |
624 | /* Callback for iterate over threads. Used to check whether |
625 | the current inferior is multi-threaded. Returns true as soon | |
626 | as it sees the second thread of the current inferior. */ | |
627 | ||
628 | static int | |
629 | inf_has_multiple_thread_cb (struct thread_info *tp, void *data) | |
630 | { | |
631 | int *count_p = (int *) data; | |
632 | ||
633 | if (current_inferior ()->pid == ptid_get_pid (tp->ptid)) | |
634 | (*count_p)++; | |
635 | ||
636 | /* Stop the iteration if multiple threads have been detected. */ | |
637 | return *count_p > 1; | |
638 | } | |
639 | ||
640 | /* Return true if the current inferior is multi-threaded. */ | |
641 | ||
642 | static int | |
643 | inf_has_multiple_threads (void) | |
644 | { | |
645 | int count = 0; | |
646 | ||
647 | iterate_over_threads (inf_has_multiple_thread_cb, &count); | |
648 | return (count > 1); | |
649 | } | |
650 | ||
ac264b3b MS |
651 | static void |
652 | checkpoint_command (char *args, int from_tty) | |
653 | { | |
3e3b026f UW |
654 | struct objfile *fork_objf; |
655 | struct gdbarch *gdbarch; | |
ac264b3b MS |
656 | struct target_waitstatus last_target_waitstatus; |
657 | ptid_t last_target_ptid; | |
658 | struct value *fork_fn = NULL, *ret; | |
659 | struct fork_info *fp; | |
660 | pid_t retpid; | |
661 | struct cleanup *old_chain; | |
74960c60 | 662 | |
92f6badc KP |
663 | if (!target_has_execution) |
664 | error (_("The program is not being run.")); | |
665 | ||
666 | /* Ensure that the inferior is not multithreaded. */ | |
667 | update_thread_list (); | |
668 | if (inf_has_multiple_threads ()) | |
669 | error (_("checkpoint: can't checkpoint multiple threads.")); | |
670 | ||
ac264b3b MS |
671 | /* Make the inferior fork, record its (and gdb's) state. */ |
672 | ||
3b7344d5 | 673 | if (lookup_minimal_symbol ("fork", NULL, NULL).minsym != NULL) |
3e3b026f | 674 | fork_fn = find_function_in_inferior ("fork", &fork_objf); |
ac264b3b | 675 | if (!fork_fn) |
3b7344d5 | 676 | if (lookup_minimal_symbol ("_fork", NULL, NULL).minsym != NULL) |
3e3b026f | 677 | fork_fn = find_function_in_inferior ("fork", &fork_objf); |
ac264b3b MS |
678 | if (!fork_fn) |
679 | error (_("checkpoint: can't find fork function in inferior.")); | |
680 | ||
3e3b026f UW |
681 | gdbarch = get_objfile_arch (fork_objf); |
682 | ret = value_from_longest (builtin_type (gdbarch)->builtin_int, 0); | |
2277426b PA |
683 | |
684 | /* Tell linux-nat.c that we're checkpointing this inferior. */ | |
685 | old_chain = make_cleanup_restore_integer (&checkpointing_pid); | |
dfd4cc63 | 686 | checkpointing_pid = ptid_get_pid (inferior_ptid); |
2277426b | 687 | |
ac264b3b MS |
688 | ret = call_function_by_hand (fork_fn, 0, &ret); |
689 | do_cleanups (old_chain); | |
690 | if (!ret) /* Probably can't happen. */ | |
691 | error (_("checkpoint: call_function_by_hand returned null.")); | |
692 | ||
693 | retpid = value_as_long (ret); | |
694 | get_last_target_status (&last_target_ptid, &last_target_waitstatus); | |
695 | if (from_tty) | |
696 | { | |
697 | int parent_pid; | |
698 | ||
3cb5bea9 | 699 | printf_filtered (_("checkpoint: fork returned pid %ld.\n"), |
ac264b3b MS |
700 | (long) retpid); |
701 | if (info_verbose) | |
702 | { | |
703 | parent_pid = ptid_get_lwp (last_target_ptid); | |
704 | if (parent_pid == 0) | |
705 | parent_pid = ptid_get_pid (last_target_ptid); | |
3cb5bea9 | 706 | printf_filtered (_(" gdb says parent = %ld.\n"), |
ac264b3b MS |
707 | (long) parent_pid); |
708 | } | |
709 | } | |
710 | ||
711 | fp = find_fork_pid (retpid); | |
712 | if (!fp) | |
713 | error (_("Failed to find new fork")); | |
714 | fork_save_infrun_state (fp, 1); | |
7a298875 | 715 | fp->parent_ptid = last_target_ptid; |
ac264b3b MS |
716 | } |
717 | ||
718 | static void | |
719 | linux_fork_context (struct fork_info *newfp, int from_tty) | |
720 | { | |
721 | /* Now we attempt to switch processes. */ | |
0d14fc63 | 722 | struct fork_info *oldfp; |
ac264b3b | 723 | |
0d14fc63 | 724 | gdb_assert (newfp != NULL); |
ac264b3b | 725 | |
0d14fc63 PA |
726 | oldfp = find_fork_ptid (inferior_ptid); |
727 | gdb_assert (oldfp != NULL); | |
ac264b3b MS |
728 | |
729 | fork_save_infrun_state (oldfp, 1); | |
74960c60 | 730 | remove_breakpoints (); |
ac264b3b | 731 | fork_load_infrun_state (newfp); |
74960c60 | 732 | insert_breakpoints (); |
ac264b3b | 733 | |
3cb5bea9 | 734 | printf_filtered (_("Switching to %s\n"), |
ac264b3b MS |
735 | target_pid_to_str (inferior_ptid)); |
736 | ||
08d72866 | 737 | print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC, 1); |
ac264b3b MS |
738 | } |
739 | ||
2277426b | 740 | /* Switch inferior process (checkpoint) context, by checkpoint id. */ |
ac264b3b MS |
741 | static void |
742 | restart_command (char *args, int from_tty) | |
743 | { | |
744 | struct fork_info *fp; | |
745 | ||
746 | if (!args || !*args) | |
747 | error (_("Requires argument (checkpoint id to restart)")); | |
748 | ||
749 | if ((fp = find_fork_id (parse_and_eval_long (args))) == NULL) | |
750 | error (_("Not found: checkpoint id %s"), args); | |
751 | ||
752 | linux_fork_context (fp, from_tty); | |
753 | } | |
754 | ||
755 | void | |
756 | _initialize_linux_fork (void) | |
757 | { | |
758 | init_fork_list (); | |
759 | ||
ac264b3b MS |
760 | /* Checkpoint command: create a fork of the inferior process |
761 | and set it aside for later debugging. */ | |
762 | ||
763 | add_com ("checkpoint", class_obscure, checkpoint_command, _("\ | |
764 | Fork a duplicate process (experimental).")); | |
765 | ||
2277426b PA |
766 | /* Restart command: restore the context of a specified checkpoint |
767 | process. */ | |
ac264b3b MS |
768 | |
769 | add_com ("restart", class_obscure, restart_command, _("\ | |
770 | restart <n>: restore program context from a checkpoint.\n\ | |
771 | Argument 'n' is checkpoint ID, as displayed by 'info checkpoints'.")); | |
772 | ||
b8db102d | 773 | /* Delete checkpoint command: kill the process and remove it from |
3cb5bea9 | 774 | the fork list. */ |
ac264b3b | 775 | |
3cb5bea9 | 776 | add_cmd ("checkpoint", class_obscure, delete_checkpoint_command, _("\ |
2277426b | 777 | Delete a checkpoint (experimental)."), |
b8db102d | 778 | &deletelist); |
ac264b3b | 779 | |
3cb5bea9 | 780 | /* Detach checkpoint command: release the process to run independently, |
ac264b3b MS |
781 | and remove it from the fork list. */ |
782 | ||
3cb5bea9 | 783 | add_cmd ("checkpoint", class_obscure, detach_checkpoint_command, _("\ |
2277426b | 784 | Detach from a checkpoint (experimental)."), |
f73adfeb | 785 | &detachlist); |
ac264b3b | 786 | |
3cb5bea9 | 787 | /* Info checkpoints command: list all forks/checkpoints |
ac264b3b MS |
788 | currently under gdb's control. */ |
789 | ||
3cb5bea9 | 790 | add_info ("checkpoints", info_checkpoints_command, |
2277426b | 791 | _("IDs of currently known checkpoints.")); |
ac264b3b | 792 | } |