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ac264b3b MS |
1 | /* GNU/Linux native-dependent code for debugging multiple forks. |
2 | ||
b811d2c2 | 3 | Copyright (C) 2005-2020 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" |
ac264b3b | 28 | #include "linux-fork.h" |
f973ed9c | 29 | #include "linux-nat.h" |
7a298875 | 30 | #include "gdbthread.h" |
05cba821 | 31 | #include "source.h" |
ac264b3b | 32 | |
5826e159 | 33 | #include "nat/gdb_ptrace.h" |
268a13a5 | 34 | #include "gdbsupport/gdb_wait.h" |
2978b111 | 35 | #include <dirent.h> |
ac264b3b MS |
36 | #include <ctype.h> |
37 | ||
06974e6c | 38 | #include <list> |
ac264b3b | 39 | |
ac264b3b MS |
40 | /* Fork list data structure: */ |
41 | struct fork_info | |
42 | { | |
06974e6c PA |
43 | explicit fork_info (pid_t pid) |
44 | : ptid (pid, pid, 0) | |
45 | { | |
46 | } | |
47 | ||
48 | ~fork_info () | |
49 | { | |
50 | /* Notes on step-resume breakpoints: since this is a concern for | |
51 | threads, let's convince ourselves that it's not a concern for | |
52 | forks. There are two ways for a fork_info to be created. | |
53 | First, by the checkpoint command, in which case we're at a gdb | |
54 | prompt and there can't be any step-resume breakpoint. Second, | |
55 | by a fork in the user program, in which case we *may* have | |
56 | stepped into the fork call, but regardless of whether we follow | |
57 | the parent or the child, we will return to the same place and | |
58 | the step-resume breakpoint, if any, will take care of itself as | |
59 | usual. And unlike threads, we do not save a private copy of | |
60 | the step-resume breakpoint -- so we're OK. */ | |
61 | ||
62 | if (savedregs) | |
63 | delete savedregs; | |
64 | if (filepos) | |
65 | xfree (filepos); | |
66 | } | |
67 | ||
68 | ptid_t ptid = null_ptid; | |
69 | ptid_t parent_ptid = null_ptid; | |
70 | ||
71 | /* Convenient handle (GDB fork id). */ | |
72 | int num = 0; | |
73 | ||
74 | /* Convenient for info fork, saves having to actually switch | |
75 | contexts. */ | |
76 | readonly_detached_regcache *savedregs = nullptr; | |
77 | ||
78 | CORE_ADDR pc = 0; | |
79 | ||
06974e6c PA |
80 | /* Set of open file descriptors' offsets. */ |
81 | off_t *filepos = nullptr; | |
82 | ||
83 | int maxfd = 0; | |
ac264b3b MS |
84 | }; |
85 | ||
06974e6c PA |
86 | static std::list<fork_info> fork_list; |
87 | static int highest_fork_num; | |
88 | ||
ac264b3b MS |
89 | /* Fork list methods: */ |
90 | ||
3cb5bea9 | 91 | int |
ac264b3b MS |
92 | forks_exist_p (void) |
93 | { | |
06974e6c | 94 | return !fork_list.empty (); |
ac264b3b MS |
95 | } |
96 | ||
2f341b6e PA |
97 | /* Return the last fork in the list. */ |
98 | ||
99 | static struct fork_info * | |
100 | find_last_fork (void) | |
101 | { | |
06974e6c | 102 | if (fork_list.empty ()) |
2f341b6e PA |
103 | return NULL; |
104 | ||
06974e6c | 105 | return &fork_list.back (); |
2f341b6e PA |
106 | } |
107 | ||
06974e6c | 108 | /* Return true iff there's one fork in the list. */ |
ac264b3b | 109 | |
06974e6c PA |
110 | static bool |
111 | one_fork_p () | |
ac264b3b | 112 | { |
fa47e446 | 113 | return fork_list.size () == 1; |
72f31aea PA |
114 | } |
115 | ||
116 | /* Add a new fork to the internal fork list. */ | |
117 | ||
118 | void | |
119 | add_fork (pid_t pid) | |
120 | { | |
06974e6c | 121 | fork_list.emplace_back (pid); |
2f341b6e | 122 | |
06974e6c PA |
123 | if (one_fork_p ()) |
124 | highest_fork_num = 0; | |
2f341b6e | 125 | |
06974e6c | 126 | fork_info *fp = &fork_list.back (); |
72f31aea | 127 | fp->num = ++highest_fork_num; |
ac264b3b MS |
128 | } |
129 | ||
ac264b3b MS |
130 | static void |
131 | delete_fork (ptid_t ptid) | |
132 | { | |
e99b03dc | 133 | linux_target->low_forget_process (ptid.pid ()); |
26cb8b7c | 134 | |
06974e6c PA |
135 | for (auto it = fork_list.begin (); it != fork_list.end (); ++it) |
136 | if (it->ptid == ptid) | |
137 | { | |
138 | fork_list.erase (it); | |
ac264b3b | 139 | |
06974e6c PA |
140 | /* Special case: if there is now only one process in the list, |
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 (one_fork_p () && fork_list.front ().ptid == inferior_ptid) | |
145 | { | |
146 | /* Last fork -- delete from list and handle as solo | |
147 | process (should be a safe recursion). */ | |
148 | delete_fork (inferior_ptid); | |
149 | } | |
150 | return; | |
151 | } | |
ac264b3b MS |
152 | } |
153 | ||
154 | /* Find a fork_info by matching PTID. */ | |
155 | static struct fork_info * | |
156 | find_fork_ptid (ptid_t ptid) | |
157 | { | |
06974e6c PA |
158 | for (fork_info &fi : fork_list) |
159 | if (fi.ptid == ptid) | |
160 | return &fi; | |
ac264b3b MS |
161 | |
162 | return NULL; | |
163 | } | |
164 | ||
165 | /* Find a fork_info by matching ID. */ | |
166 | static struct fork_info * | |
167 | find_fork_id (int num) | |
168 | { | |
06974e6c PA |
169 | for (fork_info &fi : fork_list) |
170 | if (fi.num == num) | |
171 | return &fi; | |
ac264b3b MS |
172 | |
173 | return NULL; | |
174 | } | |
175 | ||
176 | /* Find a fork_info by matching pid. */ | |
177 | extern struct fork_info * | |
178 | find_fork_pid (pid_t pid) | |
179 | { | |
06974e6c PA |
180 | for (fork_info &fi : fork_list) |
181 | if (pid == fi.ptid.pid ()) | |
182 | return &fi; | |
ac264b3b MS |
183 | |
184 | return NULL; | |
185 | } | |
186 | ||
187 | static ptid_t | |
188 | fork_id_to_ptid (int num) | |
189 | { | |
190 | struct fork_info *fork = find_fork_id (num); | |
191 | if (fork) | |
192 | return fork->ptid; | |
193 | else | |
f2907e49 | 194 | return ptid_t (-1); |
ac264b3b MS |
195 | } |
196 | ||
ac264b3b MS |
197 | /* Fork list <-> gdb interface. */ |
198 | ||
3cb5bea9 | 199 | /* Utility function for fork_load/fork_save. |
ac264b3b MS |
200 | Calls lseek in the (current) inferior process. */ |
201 | ||
202 | static off_t | |
203 | call_lseek (int fd, off_t offset, int whence) | |
204 | { | |
205 | char exp[80]; | |
206 | ||
7022349d | 207 | snprintf (&exp[0], sizeof (exp), "(long) lseek (%d, %ld, %d)", |
ac264b3b MS |
208 | fd, (long) offset, whence); |
209 | return (off_t) parse_and_eval_long (&exp[0]); | |
210 | } | |
211 | ||
212 | /* Load infrun state for the fork PTID. */ | |
213 | ||
214 | static void | |
215 | fork_load_infrun_state (struct fork_info *fp) | |
216 | { | |
ac264b3b MS |
217 | int i; |
218 | ||
2277426b | 219 | linux_nat_switch_fork (fp->ptid); |
f973ed9c | 220 | |
b7e60d85 | 221 | if (fp->savedregs) |
fc5b8736 | 222 | get_current_regcache ()->restore (fp->savedregs); |
ac264b3b | 223 | |
791b663b DJ |
224 | registers_changed (); |
225 | reinit_frame_cache (); | |
226 | ||
f2ffa92b PA |
227 | inferior_thread ()->suspend.stop_pc |
228 | = regcache_read_pc (get_current_regcache ()); | |
ac264b3b MS |
229 | nullify_last_target_wait_ptid (); |
230 | ||
231 | /* Now restore the file positions of open file descriptors. */ | |
232 | if (fp->filepos) | |
233 | { | |
234 | for (i = 0; i <= fp->maxfd; i++) | |
235 | if (fp->filepos[i] != (off_t) -1) | |
236 | call_lseek (i, fp->filepos[i], SEEK_SET); | |
237 | /* NOTE: I can get away with using SEEK_SET and SEEK_CUR because | |
238 | this is native-only. If it ever has to be cross, we'll have | |
239 | to rethink this. */ | |
240 | } | |
241 | } | |
242 | ||
b7e60d85 | 243 | /* Save infrun state for the fork FP. */ |
ac264b3b | 244 | |
2277426b | 245 | static void |
b7e60d85 | 246 | fork_save_infrun_state (struct fork_info *fp) |
ac264b3b | 247 | { |
d8d2a3ee | 248 | char path[PATH_MAX]; |
ac264b3b MS |
249 | struct dirent *de; |
250 | DIR *d; | |
251 | ||
252 | if (fp->savedregs) | |
c0e383c6 | 253 | delete fp->savedregs; |
ac264b3b | 254 | |
daf6667d YQ |
255 | fp->savedregs = new readonly_detached_regcache (*get_current_regcache ()); |
256 | fp->pc = regcache_read_pc (get_current_regcache ()); | |
ac264b3b | 257 | |
b7e60d85 PA |
258 | /* Now save the 'state' (file position) of all open file descriptors. |
259 | Unfortunately fork does not take care of that for us... */ | |
260 | snprintf (path, PATH_MAX, "/proc/%ld/fd", (long) fp->ptid.pid ()); | |
261 | if ((d = opendir (path)) != NULL) | |
ac264b3b | 262 | { |
b7e60d85 PA |
263 | long tmp; |
264 | ||
265 | fp->maxfd = 0; | |
266 | while ((de = readdir (d)) != NULL) | |
ac264b3b | 267 | { |
b7e60d85 PA |
268 | /* Count open file descriptors (actually find highest |
269 | numbered). */ | |
270 | tmp = strtol (&de->d_name[0], NULL, 10); | |
271 | if (fp->maxfd < tmp) | |
272 | fp->maxfd = tmp; | |
ac264b3b | 273 | } |
b7e60d85 PA |
274 | /* Allocate array of file positions. */ |
275 | fp->filepos = XRESIZEVEC (off_t, fp->filepos, fp->maxfd + 1); | |
276 | ||
277 | /* Initialize to -1 (invalid). */ | |
278 | for (tmp = 0; tmp <= fp->maxfd; tmp++) | |
279 | fp->filepos[tmp] = -1; | |
280 | ||
281 | /* Now find actual file positions. */ | |
282 | rewinddir (d); | |
283 | while ((de = readdir (d)) != NULL) | |
284 | if (isdigit (de->d_name[0])) | |
285 | { | |
286 | tmp = strtol (&de->d_name[0], NULL, 10); | |
287 | fp->filepos[tmp] = call_lseek (tmp, 0, SEEK_CUR); | |
288 | } | |
289 | closedir (d); | |
ac264b3b MS |
290 | } |
291 | } | |
292 | ||
293 | /* Kill 'em all, let God sort 'em out... */ | |
294 | ||
3cb5bea9 | 295 | void |
ac264b3b MS |
296 | linux_fork_killall (void) |
297 | { | |
298 | /* Walk list and kill every pid. No need to treat the | |
299 | current inferior_ptid as special (we do not return a | |
300 | status for it) -- however any process may be a child | |
301 | or a parent, so may get a SIGCHLD from a previously | |
302 | killed child. Wait them all out. */ | |
ac264b3b | 303 | |
06974e6c | 304 | for (fork_info &fi : fork_list) |
56aac7e8 | 305 | { |
06974e6c PA |
306 | pid_t pid = fi.ptid.pid (); |
307 | int status; | |
308 | pid_t ret; | |
56aac7e8 | 309 | do { |
4c28f408 PA |
310 | /* Use SIGKILL instead of PTRACE_KILL because the former works even |
311 | if the thread is running, while the later doesn't. */ | |
312 | kill (pid, SIGKILL); | |
56aac7e8 MS |
313 | ret = waitpid (pid, &status, 0); |
314 | /* We might get a SIGCHLD instead of an exit status. This is | |
315 | aggravated by the first kill above - a child has just | |
316 | died. MVS comment cut-and-pasted from linux-nat. */ | |
317 | } while (ret == pid && WIFSTOPPED (status)); | |
318 | } | |
06974e6c PA |
319 | |
320 | /* Clear list, prepare to start fresh. */ | |
321 | fork_list.clear (); | |
ac264b3b MS |
322 | } |
323 | ||
324 | /* The current inferior_ptid has exited, but there are other viable | |
325 | forks to debug. Delete the exiting one and context-switch to the | |
326 | first available. */ | |
327 | ||
3cb5bea9 | 328 | void |
ac264b3b MS |
329 | linux_fork_mourn_inferior (void) |
330 | { | |
2f341b6e PA |
331 | struct fork_info *last; |
332 | int status; | |
333 | ||
ac264b3b MS |
334 | /* Wait just one more time to collect the inferior's exit status. |
335 | Do not check whether this succeeds though, since we may be | |
336 | dealing with a process that we attached to. Such a process will | |
337 | only report its exit status to its original parent. */ | |
e99b03dc | 338 | waitpid (inferior_ptid.pid (), &status, 0); |
ac264b3b MS |
339 | |
340 | /* OK, presumably inferior_ptid is the one who has exited. | |
341 | We need to delete that one from the fork_list, and switch | |
342 | to the next available fork. */ | |
343 | delete_fork (inferior_ptid); | |
791b663b DJ |
344 | |
345 | /* There should still be a fork - if there's only one left, | |
346 | delete_fork won't remove it, because we haven't updated | |
347 | inferior_ptid yet. */ | |
06974e6c | 348 | gdb_assert (!fork_list.empty ()); |
791b663b | 349 | |
2f341b6e PA |
350 | last = find_last_fork (); |
351 | fork_load_infrun_state (last); | |
791b663b | 352 | printf_filtered (_("[Switching to %s]\n"), |
a068643d | 353 | target_pid_to_str (inferior_ptid).c_str ()); |
791b663b DJ |
354 | |
355 | /* If there's only one fork, switch back to non-fork mode. */ | |
06974e6c | 356 | if (one_fork_p ()) |
791b663b | 357 | delete_fork (inferior_ptid); |
ac264b3b MS |
358 | } |
359 | ||
7a7d3353 PA |
360 | /* The current inferior_ptid is being detached, but there are other |
361 | viable forks to debug. Detach and delete it and context-switch to | |
362 | the first available. */ | |
363 | ||
3cb5bea9 | 364 | void |
6bd6f3b6 | 365 | linux_fork_detach (int from_tty) |
7a7d3353 PA |
366 | { |
367 | /* OK, inferior_ptid is the one we are detaching from. We need to | |
368 | delete it from the fork_list, and switch to the next available | |
369 | fork. */ | |
370 | ||
e99b03dc | 371 | if (ptrace (PTRACE_DETACH, inferior_ptid.pid (), 0, 0)) |
a068643d TT |
372 | error (_("Unable to detach %s"), |
373 | target_pid_to_str (inferior_ptid).c_str ()); | |
7a7d3353 PA |
374 | |
375 | delete_fork (inferior_ptid); | |
7a7d3353 PA |
376 | |
377 | /* There should still be a fork - if there's only one left, | |
378 | delete_fork won't remove it, because we haven't updated | |
379 | inferior_ptid yet. */ | |
06974e6c | 380 | gdb_assert (!fork_list.empty ()); |
7a7d3353 | 381 | |
06974e6c | 382 | fork_load_infrun_state (&fork_list.front ()); |
7a7d3353 PA |
383 | |
384 | if (from_tty) | |
385 | printf_filtered (_("[Switching to %s]\n"), | |
a068643d | 386 | target_pid_to_str (inferior_ptid).c_str ()); |
7a7d3353 PA |
387 | |
388 | /* If there's only one fork, switch back to non-fork mode. */ | |
06974e6c | 389 | if (one_fork_p ()) |
7a7d3353 PA |
390 | delete_fork (inferior_ptid); |
391 | } | |
392 | ||
a07c8880 AB |
393 | /* Temporarily switch to the infrun state stored on the fork_info |
394 | identified by a given ptid_t. When this object goes out of scope, | |
395 | restore the currently selected infrun state. */ | |
7a298875 | 396 | |
a07c8880 AB |
397 | class scoped_switch_fork_info |
398 | { | |
399 | public: | |
400 | /* Switch to the infrun state held on the fork_info identified by | |
401 | PPTID. If PPTID is the current inferior then no switch is done. */ | |
1ef8573c | 402 | explicit scoped_switch_fork_info (ptid_t pptid) |
a07c8880 AB |
403 | : m_oldfp (nullptr) |
404 | { | |
405 | if (pptid != inferior_ptid) | |
406 | { | |
407 | struct fork_info *newfp = nullptr; | |
408 | ||
409 | /* Switch to pptid. */ | |
410 | m_oldfp = find_fork_ptid (inferior_ptid); | |
411 | gdb_assert (m_oldfp != nullptr); | |
412 | newfp = find_fork_ptid (pptid); | |
413 | gdb_assert (newfp != nullptr); | |
b7e60d85 | 414 | fork_save_infrun_state (m_oldfp); |
a07c8880 AB |
415 | remove_breakpoints (); |
416 | fork_load_infrun_state (newfp); | |
417 | insert_breakpoints (); | |
418 | } | |
419 | } | |
420 | ||
421 | /* Restore the previously selected infrun state. If the constructor | |
422 | didn't need to switch states, then nothing is done here either. */ | |
423 | ~scoped_switch_fork_info () | |
424 | { | |
425 | if (m_oldfp != nullptr) | |
426 | { | |
427 | /* Switch back to inferior_ptid. */ | |
a70b8144 | 428 | try |
1ef8573c AB |
429 | { |
430 | remove_breakpoints (); | |
431 | fork_load_infrun_state (m_oldfp); | |
432 | insert_breakpoints (); | |
433 | } | |
230d2906 | 434 | catch (const gdb_exception &ex) |
1ef8573c AB |
435 | { |
436 | warning (_("Couldn't restore checkpoint state in %s: %s"), | |
3d6e9d23 TT |
437 | target_pid_to_str (m_oldfp->ptid).c_str (), |
438 | ex.what ()); | |
1ef8573c | 439 | } |
a07c8880 AB |
440 | } |
441 | } | |
442 | ||
443 | DISABLE_COPY_AND_ASSIGN (scoped_switch_fork_info); | |
444 | ||
445 | private: | |
446 | /* The fork_info for the previously selected infrun state, or nullptr if | |
447 | we were already in the desired state, and nothing needs to be | |
448 | restored. */ | |
449 | struct fork_info *m_oldfp; | |
450 | }; | |
7a298875 HZ |
451 | |
452 | static int | |
453 | inferior_call_waitpid (ptid_t pptid, int pid) | |
454 | { | |
455 | struct objfile *waitpid_objf; | |
456 | struct value *waitpid_fn = NULL; | |
7a298875 HZ |
457 | int ret = -1; |
458 | ||
a07c8880 | 459 | scoped_switch_fork_info switch_fork_info (pptid); |
e17c9e56 | 460 | |
7a298875 | 461 | /* Get the waitpid_fn. */ |
3b7344d5 | 462 | if (lookup_minimal_symbol ("waitpid", NULL, NULL).minsym != NULL) |
7a298875 | 463 | waitpid_fn = find_function_in_inferior ("waitpid", &waitpid_objf); |
3b7344d5 TT |
464 | if (!waitpid_fn |
465 | && lookup_minimal_symbol ("_waitpid", NULL, NULL).minsym != NULL) | |
7a298875 | 466 | waitpid_fn = find_function_in_inferior ("_waitpid", &waitpid_objf); |
a07c8880 AB |
467 | if (waitpid_fn != nullptr) |
468 | { | |
469 | struct gdbarch *gdbarch = get_current_arch (); | |
470 | struct value *argv[3], *retv; | |
7a298875 | 471 | |
a07c8880 AB |
472 | /* Get the argv. */ |
473 | argv[0] = value_from_longest (builtin_type (gdbarch)->builtin_int, pid); | |
474 | argv[1] = value_from_pointer (builtin_type (gdbarch)->builtin_data_ptr, 0); | |
475 | argv[2] = value_from_longest (builtin_type (gdbarch)->builtin_int, 0); | |
7a298875 | 476 | |
a07c8880 | 477 | retv = call_function_by_hand (waitpid_fn, NULL, argv); |
7a298875 | 478 | |
a07c8880 AB |
479 | if (value_as_long (retv) >= 0) |
480 | ret = 0; | |
481 | } | |
7a298875 | 482 | |
7a298875 HZ |
483 | return ret; |
484 | } | |
485 | ||
ac264b3b MS |
486 | /* Fork list <-> user interface. */ |
487 | ||
488 | static void | |
5b64bf74 | 489 | delete_checkpoint_command (const char *args, int from_tty) |
ac264b3b | 490 | { |
e17c9e56 | 491 | ptid_t ptid, pptid; |
7a298875 | 492 | struct fork_info *fi; |
ac264b3b MS |
493 | |
494 | if (!args || !*args) | |
2277426b | 495 | error (_("Requires argument (checkpoint id to delete)")); |
ac264b3b MS |
496 | |
497 | ptid = fork_id_to_ptid (parse_and_eval_long (args)); | |
d7e15655 | 498 | if (ptid == minus_one_ptid) |
2277426b | 499 | error (_("No such checkpoint id, %s"), args); |
ac264b3b | 500 | |
d7e15655 | 501 | if (ptid == inferior_ptid) |
3cb5bea9 PA |
502 | error (_("\ |
503 | Please switch to another checkpoint before deleting the current one")); | |
ac264b3b | 504 | |
e99b03dc | 505 | if (ptrace (PTRACE_KILL, ptid.pid (), 0, 0)) |
a068643d | 506 | error (_("Unable to kill pid %s"), target_pid_to_str (ptid).c_str ()); |
ac264b3b | 507 | |
7a298875 HZ |
508 | fi = find_fork_ptid (ptid); |
509 | gdb_assert (fi); | |
e17c9e56 | 510 | pptid = fi->parent_ptid; |
7a298875 | 511 | |
ac264b3b | 512 | if (from_tty) |
a068643d | 513 | printf_filtered (_("Killed %s\n"), target_pid_to_str (ptid).c_str ()); |
ac264b3b MS |
514 | |
515 | delete_fork (ptid); | |
7a298875 HZ |
516 | |
517 | /* If fi->parent_ptid is not a part of lwp but it's a part of checkpoint | |
518 | list, waitpid the ptid. | |
00431a78 | 519 | If fi->parent_ptid is a part of lwp and it is stopped, waitpid the |
7a298875 | 520 | ptid. */ |
5b6d1e4f | 521 | thread_info *parent = find_thread_ptid (linux_target, pptid); |
00431a78 PA |
522 | if ((parent == NULL && find_fork_ptid (pptid)) |
523 | || (parent != NULL && parent->state == THREAD_STOPPED)) | |
7a298875 | 524 | { |
e99b03dc | 525 | if (inferior_call_waitpid (pptid, ptid.pid ())) |
a068643d TT |
526 | warning (_("Unable to wait pid %s"), |
527 | target_pid_to_str (ptid).c_str ()); | |
7a298875 | 528 | } |
ac264b3b MS |
529 | } |
530 | ||
531 | static void | |
5b64bf74 | 532 | detach_checkpoint_command (const char *args, int from_tty) |
ac264b3b MS |
533 | { |
534 | ptid_t ptid; | |
535 | ||
536 | if (!args || !*args) | |
2277426b | 537 | error (_("Requires argument (checkpoint id to detach)")); |
ac264b3b MS |
538 | |
539 | ptid = fork_id_to_ptid (parse_and_eval_long (args)); | |
d7e15655 | 540 | if (ptid == minus_one_ptid) |
2277426b | 541 | error (_("No such checkpoint id, %s"), args); |
ac264b3b | 542 | |
d7e15655 | 543 | if (ptid == inferior_ptid) |
2277426b PA |
544 | error (_("\ |
545 | Please switch to another checkpoint before detaching the current one")); | |
ac264b3b | 546 | |
e99b03dc | 547 | if (ptrace (PTRACE_DETACH, ptid.pid (), 0, 0)) |
a068643d | 548 | error (_("Unable to detach %s"), target_pid_to_str (ptid).c_str ()); |
ac264b3b MS |
549 | |
550 | if (from_tty) | |
a068643d | 551 | printf_filtered (_("Detached %s\n"), target_pid_to_str (ptid).c_str ()); |
ac264b3b MS |
552 | |
553 | delete_fork (ptid); | |
554 | } | |
555 | ||
3cb5bea9 | 556 | /* Print information about currently known checkpoints. */ |
ac264b3b MS |
557 | |
558 | static void | |
1d12d88f | 559 | info_checkpoints_command (const char *arg, int from_tty) |
ac264b3b | 560 | { |
5af949e3 | 561 | struct gdbarch *gdbarch = get_current_arch (); |
b8db102d | 562 | int requested = -1; |
06974e6c | 563 | const fork_info *printed = NULL; |
b8db102d MS |
564 | |
565 | if (arg && *arg) | |
566 | requested = (int) parse_and_eval_long (arg); | |
ac264b3b | 567 | |
06974e6c | 568 | for (const fork_info &fi : fork_list) |
ac264b3b | 569 | { |
06974e6c | 570 | if (requested > 0 && fi.num != requested) |
b8db102d MS |
571 | continue; |
572 | ||
06974e6c PA |
573 | printed = &fi; |
574 | if (fi.ptid == inferior_ptid) | |
daf6667d | 575 | printf_filtered ("* "); |
ac264b3b | 576 | else |
daf6667d YQ |
577 | printf_filtered (" "); |
578 | ||
06974e6c | 579 | ULONGEST pc = fi.pc; |
a068643d | 580 | printf_filtered ("%d %s", fi.num, target_pid_to_str (fi.ptid).c_str ()); |
06974e6c | 581 | if (fi.num == 0) |
ac264b3b MS |
582 | printf_filtered (_(" (main process)")); |
583 | printf_filtered (_(" at ")); | |
5af949e3 | 584 | fputs_filtered (paddress (gdbarch, pc), gdb_stdout); |
ac264b3b | 585 | |
06974e6c | 586 | symtab_and_line sal = find_pc_line (pc, 0); |
ac264b3b | 587 | if (sal.symtab) |
05cba821 JK |
588 | printf_filtered (_(", file %s"), |
589 | symtab_to_filename_for_display (sal.symtab)); | |
ac264b3b MS |
590 | if (sal.line) |
591 | printf_filtered (_(", line %d"), sal.line); | |
592 | if (!sal.symtab && !sal.line) | |
593 | { | |
7cbd4a93 | 594 | struct bound_minimal_symbol msym; |
ac264b3b MS |
595 | |
596 | msym = lookup_minimal_symbol_by_pc (pc); | |
7cbd4a93 | 597 | if (msym.minsym) |
c9d95fa3 | 598 | printf_filtered (", <%s>", msym.minsym->linkage_name ()); |
ac264b3b MS |
599 | } |
600 | ||
601 | putchar_filtered ('\n'); | |
602 | } | |
b8db102d MS |
603 | if (printed == NULL) |
604 | { | |
605 | if (requested > 0) | |
2277426b | 606 | printf_filtered (_("No checkpoint number %d.\n"), requested); |
b8db102d | 607 | else |
2277426b | 608 | printf_filtered (_("No checkpoints.\n")); |
b8db102d | 609 | } |
ac264b3b MS |
610 | } |
611 | ||
2277426b PA |
612 | /* The PID of the process we're checkpointing. */ |
613 | static int checkpointing_pid = 0; | |
ac264b3b | 614 | |
2277426b PA |
615 | int |
616 | linux_fork_checkpointing_p (int pid) | |
ac264b3b | 617 | { |
2277426b | 618 | return (checkpointing_pid == pid); |
ac264b3b MS |
619 | } |
620 | ||
92f6badc KP |
621 | /* Return true if the current inferior is multi-threaded. */ |
622 | ||
e52c971f PA |
623 | static bool |
624 | inf_has_multiple_threads () | |
92f6badc KP |
625 | { |
626 | int count = 0; | |
627 | ||
e52c971f PA |
628 | /* Return true as soon as we see the second thread of the current |
629 | inferior. */ | |
630 | for (thread_info *tp ATTRIBUTE_UNUSED : current_inferior ()->threads ()) | |
631 | if (++count > 1) | |
632 | return true; | |
633 | ||
634 | return false; | |
92f6badc KP |
635 | } |
636 | ||
ac264b3b | 637 | static void |
0b39b52e | 638 | checkpoint_command (const char *args, int from_tty) |
ac264b3b | 639 | { |
3e3b026f UW |
640 | struct objfile *fork_objf; |
641 | struct gdbarch *gdbarch; | |
ac264b3b MS |
642 | struct target_waitstatus last_target_waitstatus; |
643 | ptid_t last_target_ptid; | |
644 | struct value *fork_fn = NULL, *ret; | |
645 | struct fork_info *fp; | |
646 | pid_t retpid; | |
74960c60 | 647 | |
92f6badc KP |
648 | if (!target_has_execution) |
649 | error (_("The program is not being run.")); | |
650 | ||
651 | /* Ensure that the inferior is not multithreaded. */ | |
652 | update_thread_list (); | |
653 | if (inf_has_multiple_threads ()) | |
654 | error (_("checkpoint: can't checkpoint multiple threads.")); | |
655 | ||
ac264b3b MS |
656 | /* Make the inferior fork, record its (and gdb's) state. */ |
657 | ||
3b7344d5 | 658 | if (lookup_minimal_symbol ("fork", NULL, NULL).minsym != NULL) |
3e3b026f | 659 | fork_fn = find_function_in_inferior ("fork", &fork_objf); |
ac264b3b | 660 | if (!fork_fn) |
3b7344d5 | 661 | if (lookup_minimal_symbol ("_fork", NULL, NULL).minsym != NULL) |
3e3b026f | 662 | fork_fn = find_function_in_inferior ("fork", &fork_objf); |
ac264b3b MS |
663 | if (!fork_fn) |
664 | error (_("checkpoint: can't find fork function in inferior.")); | |
665 | ||
3e3b026f UW |
666 | gdbarch = get_objfile_arch (fork_objf); |
667 | ret = value_from_longest (builtin_type (gdbarch)->builtin_int, 0); | |
2277426b PA |
668 | |
669 | /* Tell linux-nat.c that we're checkpointing this inferior. */ | |
b7b633e9 TT |
670 | { |
671 | scoped_restore save_pid | |
e99b03dc | 672 | = make_scoped_restore (&checkpointing_pid, inferior_ptid.pid ()); |
b7b633e9 | 673 | |
e71585ff | 674 | ret = call_function_by_hand (fork_fn, NULL, {}); |
b7b633e9 | 675 | } |
2277426b | 676 | |
ac264b3b MS |
677 | if (!ret) /* Probably can't happen. */ |
678 | error (_("checkpoint: call_function_by_hand returned null.")); | |
679 | ||
680 | retpid = value_as_long (ret); | |
5b6d1e4f | 681 | get_last_target_status (nullptr, &last_target_ptid, &last_target_waitstatus); |
6f9d33d8 PP |
682 | |
683 | fp = find_fork_pid (retpid); | |
684 | ||
ac264b3b MS |
685 | if (from_tty) |
686 | { | |
687 | int parent_pid; | |
688 | ||
6f9d33d8 PP |
689 | printf_filtered (_("checkpoint %d: fork returned pid %ld.\n"), |
690 | fp != NULL ? fp->num : -1, (long) retpid); | |
ac264b3b MS |
691 | if (info_verbose) |
692 | { | |
e38504b3 | 693 | parent_pid = last_target_ptid.lwp (); |
ac264b3b | 694 | if (parent_pid == 0) |
e99b03dc | 695 | parent_pid = last_target_ptid.pid (); |
3cb5bea9 | 696 | printf_filtered (_(" gdb says parent = %ld.\n"), |
ac264b3b MS |
697 | (long) parent_pid); |
698 | } | |
699 | } | |
700 | ||
ac264b3b MS |
701 | if (!fp) |
702 | error (_("Failed to find new fork")); | |
72f31aea | 703 | |
06974e6c | 704 | if (one_fork_p ()) |
72f31aea PA |
705 | { |
706 | /* Special case -- if this is the first fork in the list (the | |
707 | list was hitherto empty), then add inferior_ptid first, as a | |
708 | special zeroeth fork id. */ | |
06974e6c | 709 | fork_list.emplace_front (inferior_ptid.pid ()); |
72f31aea PA |
710 | } |
711 | ||
b7e60d85 | 712 | fork_save_infrun_state (fp); |
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 | 726 | |
b7e60d85 | 727 | fork_save_infrun_state (oldfp); |
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"), |
a068643d | 733 | target_pid_to_str (inferior_ptid).c_str ()); |
ac264b3b | 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 | 739 | static void |
0b39b52e | 740 | restart_command (const char *args, int from_tty) |
ac264b3b MS |
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 | ||
6c265988 | 753 | void _initialize_linux_fork (); |
ac264b3b | 754 | void |
6c265988 | 755 | _initialize_linux_fork () |
ac264b3b | 756 | { |
ac264b3b MS |
757 | /* Checkpoint command: create a fork of the inferior process |
758 | and set it aside for later debugging. */ | |
759 | ||
760 | add_com ("checkpoint", class_obscure, checkpoint_command, _("\ | |
761 | Fork a duplicate process (experimental).")); | |
762 | ||
2277426b PA |
763 | /* Restart command: restore the context of a specified checkpoint |
764 | process. */ | |
ac264b3b MS |
765 | |
766 | add_com ("restart", class_obscure, restart_command, _("\ | |
590042fc PW |
767 | Restore program context from a checkpoint.\n\ |
768 | Usage: restart N\n\ | |
c8a15b78 | 769 | Argument N is checkpoint ID, as displayed by 'info checkpoints'.")); |
ac264b3b | 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 | } |