Commit | Line | Data |
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3993f6b1 | 1 | /* GNU/Linux native-dependent code common to multiple platforms. |
dba24537 | 2 | |
32d0add0 | 3 | Copyright (C) 2001-2015 Free Software Foundation, Inc. |
3993f6b1 DJ |
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 |
3993f6b1 DJ |
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/>. */ |
3993f6b1 DJ |
19 | |
20 | #include "defs.h" | |
21 | #include "inferior.h" | |
45741a9c | 22 | #include "infrun.h" |
3993f6b1 | 23 | #include "target.h" |
96d7229d LM |
24 | #include "nat/linux-nat.h" |
25 | #include "nat/linux-waitpid.h" | |
3993f6b1 | 26 | #include "gdb_wait.h" |
d6b0e80f AC |
27 | #ifdef HAVE_TKILL_SYSCALL |
28 | #include <unistd.h> | |
29 | #include <sys/syscall.h> | |
30 | #endif | |
3993f6b1 | 31 | #include <sys/ptrace.h> |
0274a8ce | 32 | #include "linux-nat.h" |
125f8a3d GB |
33 | #include "nat/linux-ptrace.h" |
34 | #include "nat/linux-procfs.h" | |
8cc73a39 | 35 | #include "nat/linux-personality.h" |
ac264b3b | 36 | #include "linux-fork.h" |
d6b0e80f AC |
37 | #include "gdbthread.h" |
38 | #include "gdbcmd.h" | |
39 | #include "regcache.h" | |
4f844a66 | 40 | #include "regset.h" |
dab06dbe | 41 | #include "inf-child.h" |
10d6c8cd DJ |
42 | #include "inf-ptrace.h" |
43 | #include "auxv.h" | |
1777feb0 | 44 | #include <sys/procfs.h> /* for elf_gregset etc. */ |
dba24537 AC |
45 | #include "elf-bfd.h" /* for elfcore_write_* */ |
46 | #include "gregset.h" /* for gregset */ | |
47 | #include "gdbcore.h" /* for get_exec_file */ | |
48 | #include <ctype.h> /* for isdigit */ | |
53ce3c39 | 49 | #include <sys/stat.h> /* for struct stat */ |
dba24537 | 50 | #include <fcntl.h> /* for O_RDONLY */ |
b84876c2 PA |
51 | #include "inf-loop.h" |
52 | #include "event-loop.h" | |
53 | #include "event-top.h" | |
07e059b5 VP |
54 | #include <pwd.h> |
55 | #include <sys/types.h> | |
2978b111 | 56 | #include <dirent.h> |
07e059b5 | 57 | #include "xml-support.h" |
efcbbd14 | 58 | #include <sys/vfs.h> |
6c95b8df | 59 | #include "solib.h" |
125f8a3d | 60 | #include "nat/linux-osdata.h" |
6432734d | 61 | #include "linux-tdep.h" |
7dcd53a0 | 62 | #include "symfile.h" |
5808517f YQ |
63 | #include "agent.h" |
64 | #include "tracepoint.h" | |
87b0bb13 | 65 | #include "buffer.h" |
6ecd4729 | 66 | #include "target-descriptions.h" |
614c279d | 67 | #include "filestuff.h" |
77e371c0 | 68 | #include "objfiles.h" |
efcbbd14 UW |
69 | |
70 | #ifndef SPUFS_MAGIC | |
71 | #define SPUFS_MAGIC 0x23c9b64e | |
72 | #endif | |
dba24537 | 73 | |
1777feb0 | 74 | /* This comment documents high-level logic of this file. |
8a77dff3 VP |
75 | |
76 | Waiting for events in sync mode | |
77 | =============================== | |
78 | ||
79 | When waiting for an event in a specific thread, we just use waitpid, passing | |
80 | the specific pid, and not passing WNOHANG. | |
81 | ||
1777feb0 | 82 | When waiting for an event in all threads, waitpid is not quite good. Prior to |
8a77dff3 | 83 | version 2.4, Linux can either wait for event in main thread, or in secondary |
1777feb0 | 84 | threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might |
8a77dff3 VP |
85 | miss an event. The solution is to use non-blocking waitpid, together with |
86 | sigsuspend. First, we use non-blocking waitpid to get an event in the main | |
1777feb0 | 87 | process, if any. Second, we use non-blocking waitpid with the __WCLONED |
8a77dff3 VP |
88 | flag to check for events in cloned processes. If nothing is found, we use |
89 | sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something | |
90 | happened to a child process -- and SIGCHLD will be delivered both for events | |
91 | in main debugged process and in cloned processes. As soon as we know there's | |
3e43a32a MS |
92 | an event, we get back to calling nonblocking waitpid with and without |
93 | __WCLONED. | |
8a77dff3 VP |
94 | |
95 | Note that SIGCHLD should be blocked between waitpid and sigsuspend calls, | |
1777feb0 | 96 | so that we don't miss a signal. If SIGCHLD arrives in between, when it's |
8a77dff3 VP |
97 | blocked, the signal becomes pending and sigsuspend immediately |
98 | notices it and returns. | |
99 | ||
100 | Waiting for events in async mode | |
101 | ================================ | |
102 | ||
7feb7d06 PA |
103 | In async mode, GDB should always be ready to handle both user input |
104 | and target events, so neither blocking waitpid nor sigsuspend are | |
105 | viable options. Instead, we should asynchronously notify the GDB main | |
106 | event loop whenever there's an unprocessed event from the target. We | |
107 | detect asynchronous target events by handling SIGCHLD signals. To | |
108 | notify the event loop about target events, the self-pipe trick is used | |
109 | --- a pipe is registered as waitable event source in the event loop, | |
110 | the event loop select/poll's on the read end of this pipe (as well on | |
111 | other event sources, e.g., stdin), and the SIGCHLD handler writes a | |
112 | byte to this pipe. This is more portable than relying on | |
113 | pselect/ppoll, since on kernels that lack those syscalls, libc | |
114 | emulates them with select/poll+sigprocmask, and that is racy | |
115 | (a.k.a. plain broken). | |
116 | ||
117 | Obviously, if we fail to notify the event loop if there's a target | |
118 | event, it's bad. OTOH, if we notify the event loop when there's no | |
119 | event from the target, linux_nat_wait will detect that there's no real | |
120 | event to report, and return event of type TARGET_WAITKIND_IGNORE. | |
121 | This is mostly harmless, but it will waste time and is better avoided. | |
122 | ||
123 | The main design point is that every time GDB is outside linux-nat.c, | |
124 | we have a SIGCHLD handler installed that is called when something | |
125 | happens to the target and notifies the GDB event loop. Whenever GDB | |
126 | core decides to handle the event, and calls into linux-nat.c, we | |
127 | process things as in sync mode, except that the we never block in | |
128 | sigsuspend. | |
129 | ||
130 | While processing an event, we may end up momentarily blocked in | |
131 | waitpid calls. Those waitpid calls, while blocking, are guarantied to | |
132 | return quickly. E.g., in all-stop mode, before reporting to the core | |
133 | that an LWP hit a breakpoint, all LWPs are stopped by sending them | |
134 | SIGSTOP, and synchronously waiting for the SIGSTOP to be reported. | |
135 | Note that this is different from blocking indefinitely waiting for the | |
136 | next event --- here, we're already handling an event. | |
8a77dff3 VP |
137 | |
138 | Use of signals | |
139 | ============== | |
140 | ||
141 | We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another | |
142 | signal is not entirely significant; we just need for a signal to be delivered, | |
143 | so that we can intercept it. SIGSTOP's advantage is that it can not be | |
144 | blocked. A disadvantage is that it is not a real-time signal, so it can only | |
145 | be queued once; we do not keep track of other sources of SIGSTOP. | |
146 | ||
147 | Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't | |
148 | use them, because they have special behavior when the signal is generated - | |
149 | not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL | |
150 | kills the entire thread group. | |
151 | ||
152 | A delivered SIGSTOP would stop the entire thread group, not just the thread we | |
153 | tkill'd. But we never let the SIGSTOP be delivered; we always intercept and | |
154 | cancel it (by PTRACE_CONT without passing SIGSTOP). | |
155 | ||
156 | We could use a real-time signal instead. This would solve those problems; we | |
157 | could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB. | |
158 | But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH | |
159 | generates it, and there are races with trying to find a signal that is not | |
160 | blocked. */ | |
a0ef4274 | 161 | |
dba24537 AC |
162 | #ifndef O_LARGEFILE |
163 | #define O_LARGEFILE 0 | |
164 | #endif | |
0274a8ce | 165 | |
10d6c8cd DJ |
166 | /* The single-threaded native GNU/Linux target_ops. We save a pointer for |
167 | the use of the multi-threaded target. */ | |
168 | static struct target_ops *linux_ops; | |
f973ed9c | 169 | static struct target_ops linux_ops_saved; |
10d6c8cd | 170 | |
9f0bdab8 | 171 | /* The method to call, if any, when a new thread is attached. */ |
7b50312a PA |
172 | static void (*linux_nat_new_thread) (struct lwp_info *); |
173 | ||
26cb8b7c PA |
174 | /* The method to call, if any, when a new fork is attached. */ |
175 | static linux_nat_new_fork_ftype *linux_nat_new_fork; | |
176 | ||
177 | /* The method to call, if any, when a process is no longer | |
178 | attached. */ | |
179 | static linux_nat_forget_process_ftype *linux_nat_forget_process_hook; | |
180 | ||
7b50312a PA |
181 | /* Hook to call prior to resuming a thread. */ |
182 | static void (*linux_nat_prepare_to_resume) (struct lwp_info *); | |
9f0bdab8 | 183 | |
5b009018 PA |
184 | /* The method to call, if any, when the siginfo object needs to be |
185 | converted between the layout returned by ptrace, and the layout in | |
186 | the architecture of the inferior. */ | |
a5362b9a | 187 | static int (*linux_nat_siginfo_fixup) (siginfo_t *, |
5b009018 PA |
188 | gdb_byte *, |
189 | int); | |
190 | ||
ac264b3b MS |
191 | /* The saved to_xfer_partial method, inherited from inf-ptrace.c. |
192 | Called by our to_xfer_partial. */ | |
4ac248ca | 193 | static target_xfer_partial_ftype *super_xfer_partial; |
10d6c8cd | 194 | |
6a3cb8e8 PA |
195 | /* The saved to_close method, inherited from inf-ptrace.c. |
196 | Called by our to_close. */ | |
197 | static void (*super_close) (struct target_ops *); | |
198 | ||
ccce17b0 | 199 | static unsigned int debug_linux_nat; |
920d2a44 AC |
200 | static void |
201 | show_debug_linux_nat (struct ui_file *file, int from_tty, | |
202 | struct cmd_list_element *c, const char *value) | |
203 | { | |
204 | fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"), | |
205 | value); | |
206 | } | |
d6b0e80f | 207 | |
ae087d01 DJ |
208 | struct simple_pid_list |
209 | { | |
210 | int pid; | |
3d799a95 | 211 | int status; |
ae087d01 DJ |
212 | struct simple_pid_list *next; |
213 | }; | |
214 | struct simple_pid_list *stopped_pids; | |
215 | ||
3dd5b83d PA |
216 | /* Async mode support. */ |
217 | ||
b84876c2 PA |
218 | /* The read/write ends of the pipe registered as waitable file in the |
219 | event loop. */ | |
220 | static int linux_nat_event_pipe[2] = { -1, -1 }; | |
221 | ||
198297aa PA |
222 | /* True if we're currently in async mode. */ |
223 | #define linux_is_async_p() (linux_nat_event_pipe[0] != -1) | |
224 | ||
7feb7d06 | 225 | /* Flush the event pipe. */ |
b84876c2 | 226 | |
7feb7d06 PA |
227 | static void |
228 | async_file_flush (void) | |
b84876c2 | 229 | { |
7feb7d06 PA |
230 | int ret; |
231 | char buf; | |
b84876c2 | 232 | |
7feb7d06 | 233 | do |
b84876c2 | 234 | { |
7feb7d06 | 235 | ret = read (linux_nat_event_pipe[0], &buf, 1); |
b84876c2 | 236 | } |
7feb7d06 | 237 | while (ret >= 0 || (ret == -1 && errno == EINTR)); |
b84876c2 PA |
238 | } |
239 | ||
7feb7d06 PA |
240 | /* Put something (anything, doesn't matter what, or how much) in event |
241 | pipe, so that the select/poll in the event-loop realizes we have | |
242 | something to process. */ | |
252fbfc8 | 243 | |
b84876c2 | 244 | static void |
7feb7d06 | 245 | async_file_mark (void) |
b84876c2 | 246 | { |
7feb7d06 | 247 | int ret; |
b84876c2 | 248 | |
7feb7d06 PA |
249 | /* It doesn't really matter what the pipe contains, as long we end |
250 | up with something in it. Might as well flush the previous | |
251 | left-overs. */ | |
252 | async_file_flush (); | |
b84876c2 | 253 | |
7feb7d06 | 254 | do |
b84876c2 | 255 | { |
7feb7d06 | 256 | ret = write (linux_nat_event_pipe[1], "+", 1); |
b84876c2 | 257 | } |
7feb7d06 | 258 | while (ret == -1 && errno == EINTR); |
b84876c2 | 259 | |
7feb7d06 PA |
260 | /* Ignore EAGAIN. If the pipe is full, the event loop will already |
261 | be awakened anyway. */ | |
b84876c2 PA |
262 | } |
263 | ||
7feb7d06 PA |
264 | static int kill_lwp (int lwpid, int signo); |
265 | ||
266 | static int stop_callback (struct lwp_info *lp, void *data); | |
267 | ||
268 | static void block_child_signals (sigset_t *prev_mask); | |
269 | static void restore_child_signals_mask (sigset_t *prev_mask); | |
2277426b PA |
270 | |
271 | struct lwp_info; | |
272 | static struct lwp_info *add_lwp (ptid_t ptid); | |
273 | static void purge_lwp_list (int pid); | |
4403d8e9 | 274 | static void delete_lwp (ptid_t ptid); |
2277426b PA |
275 | static struct lwp_info *find_lwp_pid (ptid_t ptid); |
276 | ||
8a99810d PA |
277 | static int lwp_status_pending_p (struct lwp_info *lp); |
278 | ||
9c02b525 PA |
279 | static int check_stopped_by_breakpoint (struct lwp_info *lp); |
280 | static int sigtrap_is_event (int status); | |
281 | static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event; | |
282 | ||
ae087d01 DJ |
283 | \f |
284 | /* Trivial list manipulation functions to keep track of a list of | |
285 | new stopped processes. */ | |
286 | static void | |
3d799a95 | 287 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
ae087d01 DJ |
288 | { |
289 | struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list)); | |
e0881a8e | 290 | |
ae087d01 | 291 | new_pid->pid = pid; |
3d799a95 | 292 | new_pid->status = status; |
ae087d01 DJ |
293 | new_pid->next = *listp; |
294 | *listp = new_pid; | |
295 | } | |
296 | ||
84636d28 PA |
297 | static int |
298 | in_pid_list_p (struct simple_pid_list *list, int pid) | |
299 | { | |
300 | struct simple_pid_list *p; | |
301 | ||
302 | for (p = list; p != NULL; p = p->next) | |
303 | if (p->pid == pid) | |
304 | return 1; | |
305 | return 0; | |
306 | } | |
307 | ||
ae087d01 | 308 | static int |
46a96992 | 309 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
ae087d01 DJ |
310 | { |
311 | struct simple_pid_list **p; | |
312 | ||
313 | for (p = listp; *p != NULL; p = &(*p)->next) | |
314 | if ((*p)->pid == pid) | |
315 | { | |
316 | struct simple_pid_list *next = (*p)->next; | |
e0881a8e | 317 | |
46a96992 | 318 | *statusp = (*p)->status; |
ae087d01 DJ |
319 | xfree (*p); |
320 | *p = next; | |
321 | return 1; | |
322 | } | |
323 | return 0; | |
324 | } | |
325 | ||
96d7229d | 326 | /* Initialize ptrace warnings and check for supported ptrace |
beed38b8 JB |
327 | features given PID. |
328 | ||
329 | ATTACHED should be nonzero iff we attached to the inferior. */ | |
3993f6b1 DJ |
330 | |
331 | static void | |
beed38b8 | 332 | linux_init_ptrace (pid_t pid, int attached) |
3993f6b1 | 333 | { |
beed38b8 | 334 | linux_enable_event_reporting (pid, attached); |
96d7229d | 335 | linux_ptrace_init_warnings (); |
4de4c07c DJ |
336 | } |
337 | ||
6d8fd2b7 | 338 | static void |
f045800c | 339 | linux_child_post_attach (struct target_ops *self, int pid) |
4de4c07c | 340 | { |
beed38b8 | 341 | linux_init_ptrace (pid, 1); |
4de4c07c DJ |
342 | } |
343 | ||
10d6c8cd | 344 | static void |
2e97a79e | 345 | linux_child_post_startup_inferior (struct target_ops *self, ptid_t ptid) |
4de4c07c | 346 | { |
beed38b8 | 347 | linux_init_ptrace (ptid_get_pid (ptid), 0); |
4de4c07c DJ |
348 | } |
349 | ||
4403d8e9 JK |
350 | /* Return the number of known LWPs in the tgid given by PID. */ |
351 | ||
352 | static int | |
353 | num_lwps (int pid) | |
354 | { | |
355 | int count = 0; | |
356 | struct lwp_info *lp; | |
357 | ||
358 | for (lp = lwp_list; lp; lp = lp->next) | |
359 | if (ptid_get_pid (lp->ptid) == pid) | |
360 | count++; | |
361 | ||
362 | return count; | |
363 | } | |
364 | ||
365 | /* Call delete_lwp with prototype compatible for make_cleanup. */ | |
366 | ||
367 | static void | |
368 | delete_lwp_cleanup (void *lp_voidp) | |
369 | { | |
370 | struct lwp_info *lp = lp_voidp; | |
371 | ||
372 | delete_lwp (lp->ptid); | |
373 | } | |
374 | ||
d83ad864 DB |
375 | /* Target hook for follow_fork. On entry inferior_ptid must be the |
376 | ptid of the followed inferior. At return, inferior_ptid will be | |
377 | unchanged. */ | |
378 | ||
6d8fd2b7 | 379 | static int |
07107ca6 LM |
380 | linux_child_follow_fork (struct target_ops *ops, int follow_child, |
381 | int detach_fork) | |
3993f6b1 | 382 | { |
d83ad864 | 383 | if (!follow_child) |
4de4c07c | 384 | { |
6c95b8df | 385 | struct lwp_info *child_lp = NULL; |
d83ad864 DB |
386 | int status = W_STOPCODE (0); |
387 | struct cleanup *old_chain; | |
388 | int has_vforked; | |
389 | int parent_pid, child_pid; | |
390 | ||
391 | has_vforked = (inferior_thread ()->pending_follow.kind | |
392 | == TARGET_WAITKIND_VFORKED); | |
393 | parent_pid = ptid_get_lwp (inferior_ptid); | |
394 | if (parent_pid == 0) | |
395 | parent_pid = ptid_get_pid (inferior_ptid); | |
396 | child_pid | |
397 | = ptid_get_pid (inferior_thread ()->pending_follow.value.related_pid); | |
398 | ||
4de4c07c | 399 | |
1777feb0 | 400 | /* We're already attached to the parent, by default. */ |
d83ad864 DB |
401 | old_chain = save_inferior_ptid (); |
402 | inferior_ptid = ptid_build (child_pid, child_pid, 0); | |
403 | child_lp = add_lwp (inferior_ptid); | |
404 | child_lp->stopped = 1; | |
405 | child_lp->last_resume_kind = resume_stop; | |
4de4c07c | 406 | |
ac264b3b MS |
407 | /* Detach new forked process? */ |
408 | if (detach_fork) | |
f75c00e4 | 409 | { |
4403d8e9 JK |
410 | make_cleanup (delete_lwp_cleanup, child_lp); |
411 | ||
4403d8e9 JK |
412 | if (linux_nat_prepare_to_resume != NULL) |
413 | linux_nat_prepare_to_resume (child_lp); | |
c077881a HZ |
414 | |
415 | /* When debugging an inferior in an architecture that supports | |
416 | hardware single stepping on a kernel without commit | |
417 | 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child | |
418 | process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits | |
419 | set if the parent process had them set. | |
420 | To work around this, single step the child process | |
421 | once before detaching to clear the flags. */ | |
422 | ||
423 | if (!gdbarch_software_single_step_p (target_thread_architecture | |
424 | (child_lp->ptid))) | |
425 | { | |
c077881a HZ |
426 | linux_disable_event_reporting (child_pid); |
427 | if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0) | |
428 | perror_with_name (_("Couldn't do single step")); | |
429 | if (my_waitpid (child_pid, &status, 0) < 0) | |
430 | perror_with_name (_("Couldn't wait vfork process")); | |
431 | } | |
432 | ||
433 | if (WIFSTOPPED (status)) | |
9caaaa83 PA |
434 | { |
435 | int signo; | |
436 | ||
437 | signo = WSTOPSIG (status); | |
438 | if (signo != 0 | |
439 | && !signal_pass_state (gdb_signal_from_host (signo))) | |
440 | signo = 0; | |
441 | ptrace (PTRACE_DETACH, child_pid, 0, signo); | |
442 | } | |
4403d8e9 | 443 | |
d83ad864 | 444 | /* Resets value of inferior_ptid to parent ptid. */ |
4403d8e9 | 445 | do_cleanups (old_chain); |
ac264b3b MS |
446 | } |
447 | else | |
448 | { | |
6c95b8df | 449 | /* Let the thread_db layer learn about this new process. */ |
2277426b | 450 | check_for_thread_db (); |
ac264b3b | 451 | } |
9016a515 | 452 | |
d83ad864 DB |
453 | do_cleanups (old_chain); |
454 | ||
9016a515 DJ |
455 | if (has_vforked) |
456 | { | |
3ced3da4 | 457 | struct lwp_info *parent_lp; |
6c95b8df | 458 | |
3ced3da4 | 459 | parent_lp = find_lwp_pid (pid_to_ptid (parent_pid)); |
96d7229d | 460 | gdb_assert (linux_supports_tracefork () >= 0); |
3ced3da4 | 461 | |
96d7229d | 462 | if (linux_supports_tracevforkdone ()) |
9016a515 | 463 | { |
6c95b8df PA |
464 | if (debug_linux_nat) |
465 | fprintf_unfiltered (gdb_stdlog, | |
466 | "LCFF: waiting for VFORK_DONE on %d\n", | |
467 | parent_pid); | |
3ced3da4 | 468 | parent_lp->stopped = 1; |
9016a515 | 469 | |
6c95b8df PA |
470 | /* We'll handle the VFORK_DONE event like any other |
471 | event, in target_wait. */ | |
9016a515 DJ |
472 | } |
473 | else | |
474 | { | |
475 | /* We can't insert breakpoints until the child has | |
476 | finished with the shared memory region. We need to | |
477 | wait until that happens. Ideal would be to just | |
478 | call: | |
479 | - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0); | |
480 | - waitpid (parent_pid, &status, __WALL); | |
481 | However, most architectures can't handle a syscall | |
482 | being traced on the way out if it wasn't traced on | |
483 | the way in. | |
484 | ||
485 | We might also think to loop, continuing the child | |
486 | until it exits or gets a SIGTRAP. One problem is | |
487 | that the child might call ptrace with PTRACE_TRACEME. | |
488 | ||
489 | There's no simple and reliable way to figure out when | |
490 | the vforked child will be done with its copy of the | |
491 | shared memory. We could step it out of the syscall, | |
492 | two instructions, let it go, and then single-step the | |
493 | parent once. When we have hardware single-step, this | |
494 | would work; with software single-step it could still | |
495 | be made to work but we'd have to be able to insert | |
496 | single-step breakpoints in the child, and we'd have | |
497 | to insert -just- the single-step breakpoint in the | |
498 | parent. Very awkward. | |
499 | ||
500 | In the end, the best we can do is to make sure it | |
501 | runs for a little while. Hopefully it will be out of | |
502 | range of any breakpoints we reinsert. Usually this | |
503 | is only the single-step breakpoint at vfork's return | |
504 | point. */ | |
505 | ||
6c95b8df PA |
506 | if (debug_linux_nat) |
507 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
508 | "LCFF: no VFORK_DONE " |
509 | "support, sleeping a bit\n"); | |
6c95b8df | 510 | |
9016a515 | 511 | usleep (10000); |
9016a515 | 512 | |
6c95b8df PA |
513 | /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event, |
514 | and leave it pending. The next linux_nat_resume call | |
515 | will notice a pending event, and bypasses actually | |
516 | resuming the inferior. */ | |
3ced3da4 PA |
517 | parent_lp->status = 0; |
518 | parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE; | |
519 | parent_lp->stopped = 1; | |
6c95b8df PA |
520 | |
521 | /* If we're in async mode, need to tell the event loop | |
522 | there's something here to process. */ | |
523 | if (target_can_async_p ()) | |
524 | async_file_mark (); | |
525 | } | |
9016a515 | 526 | } |
4de4c07c | 527 | } |
3993f6b1 | 528 | else |
4de4c07c | 529 | { |
3ced3da4 | 530 | struct lwp_info *child_lp; |
4de4c07c | 531 | |
3ced3da4 PA |
532 | child_lp = add_lwp (inferior_ptid); |
533 | child_lp->stopped = 1; | |
25289eb2 | 534 | child_lp->last_resume_kind = resume_stop; |
6c95b8df | 535 | |
6c95b8df | 536 | /* Let the thread_db layer learn about this new process. */ |
ef29ce1a | 537 | check_for_thread_db (); |
4de4c07c DJ |
538 | } |
539 | ||
540 | return 0; | |
541 | } | |
542 | ||
4de4c07c | 543 | \f |
77b06cd7 | 544 | static int |
a863b201 | 545 | linux_child_insert_fork_catchpoint (struct target_ops *self, int pid) |
4de4c07c | 546 | { |
96d7229d | 547 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
548 | } |
549 | ||
eb73ad13 | 550 | static int |
973fc227 | 551 | linux_child_remove_fork_catchpoint (struct target_ops *self, int pid) |
eb73ad13 PA |
552 | { |
553 | return 0; | |
554 | } | |
555 | ||
77b06cd7 | 556 | static int |
3ecc7da0 | 557 | linux_child_insert_vfork_catchpoint (struct target_ops *self, int pid) |
3993f6b1 | 558 | { |
96d7229d | 559 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
560 | } |
561 | ||
eb73ad13 | 562 | static int |
e98cf0cd | 563 | linux_child_remove_vfork_catchpoint (struct target_ops *self, int pid) |
eb73ad13 PA |
564 | { |
565 | return 0; | |
566 | } | |
567 | ||
77b06cd7 | 568 | static int |
ba025e51 | 569 | linux_child_insert_exec_catchpoint (struct target_ops *self, int pid) |
3993f6b1 | 570 | { |
96d7229d | 571 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
572 | } |
573 | ||
eb73ad13 | 574 | static int |
758e29d2 | 575 | linux_child_remove_exec_catchpoint (struct target_ops *self, int pid) |
eb73ad13 PA |
576 | { |
577 | return 0; | |
578 | } | |
579 | ||
a96d9b2e | 580 | static int |
ff214e67 TT |
581 | linux_child_set_syscall_catchpoint (struct target_ops *self, |
582 | int pid, int needed, int any_count, | |
a96d9b2e SDJ |
583 | int table_size, int *table) |
584 | { | |
96d7229d | 585 | if (!linux_supports_tracesysgood ()) |
77b06cd7 TJB |
586 | return 1; |
587 | ||
a96d9b2e SDJ |
588 | /* On GNU/Linux, we ignore the arguments. It means that we only |
589 | enable the syscall catchpoints, but do not disable them. | |
77b06cd7 | 590 | |
a96d9b2e SDJ |
591 | Also, we do not use the `table' information because we do not |
592 | filter system calls here. We let GDB do the logic for us. */ | |
593 | return 0; | |
594 | } | |
595 | ||
d6b0e80f AC |
596 | /* On GNU/Linux there are no real LWP's. The closest thing to LWP's |
597 | are processes sharing the same VM space. A multi-threaded process | |
598 | is basically a group of such processes. However, such a grouping | |
599 | is almost entirely a user-space issue; the kernel doesn't enforce | |
600 | such a grouping at all (this might change in the future). In | |
601 | general, we'll rely on the threads library (i.e. the GNU/Linux | |
602 | Threads library) to provide such a grouping. | |
603 | ||
604 | It is perfectly well possible to write a multi-threaded application | |
605 | without the assistance of a threads library, by using the clone | |
606 | system call directly. This module should be able to give some | |
607 | rudimentary support for debugging such applications if developers | |
608 | specify the CLONE_PTRACE flag in the clone system call, and are | |
609 | using the Linux kernel 2.4 or above. | |
610 | ||
611 | Note that there are some peculiarities in GNU/Linux that affect | |
612 | this code: | |
613 | ||
614 | - In general one should specify the __WCLONE flag to waitpid in | |
615 | order to make it report events for any of the cloned processes | |
616 | (and leave it out for the initial process). However, if a cloned | |
617 | process has exited the exit status is only reported if the | |
618 | __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but | |
619 | we cannot use it since GDB must work on older systems too. | |
620 | ||
621 | - When a traced, cloned process exits and is waited for by the | |
622 | debugger, the kernel reassigns it to the original parent and | |
623 | keeps it around as a "zombie". Somehow, the GNU/Linux Threads | |
624 | library doesn't notice this, which leads to the "zombie problem": | |
625 | When debugged a multi-threaded process that spawns a lot of | |
626 | threads will run out of processes, even if the threads exit, | |
627 | because the "zombies" stay around. */ | |
628 | ||
629 | /* List of known LWPs. */ | |
9f0bdab8 | 630 | struct lwp_info *lwp_list; |
d6b0e80f AC |
631 | \f |
632 | ||
d6b0e80f AC |
633 | /* Original signal mask. */ |
634 | static sigset_t normal_mask; | |
635 | ||
636 | /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in | |
637 | _initialize_linux_nat. */ | |
638 | static sigset_t suspend_mask; | |
639 | ||
7feb7d06 PA |
640 | /* Signals to block to make that sigsuspend work. */ |
641 | static sigset_t blocked_mask; | |
642 | ||
643 | /* SIGCHLD action. */ | |
644 | struct sigaction sigchld_action; | |
b84876c2 | 645 | |
7feb7d06 PA |
646 | /* Block child signals (SIGCHLD and linux threads signals), and store |
647 | the previous mask in PREV_MASK. */ | |
84e46146 | 648 | |
7feb7d06 PA |
649 | static void |
650 | block_child_signals (sigset_t *prev_mask) | |
651 | { | |
652 | /* Make sure SIGCHLD is blocked. */ | |
653 | if (!sigismember (&blocked_mask, SIGCHLD)) | |
654 | sigaddset (&blocked_mask, SIGCHLD); | |
655 | ||
656 | sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask); | |
657 | } | |
658 | ||
659 | /* Restore child signals mask, previously returned by | |
660 | block_child_signals. */ | |
661 | ||
662 | static void | |
663 | restore_child_signals_mask (sigset_t *prev_mask) | |
664 | { | |
665 | sigprocmask (SIG_SETMASK, prev_mask, NULL); | |
666 | } | |
2455069d UW |
667 | |
668 | /* Mask of signals to pass directly to the inferior. */ | |
669 | static sigset_t pass_mask; | |
670 | ||
671 | /* Update signals to pass to the inferior. */ | |
672 | static void | |
94bedb42 TT |
673 | linux_nat_pass_signals (struct target_ops *self, |
674 | int numsigs, unsigned char *pass_signals) | |
2455069d UW |
675 | { |
676 | int signo; | |
677 | ||
678 | sigemptyset (&pass_mask); | |
679 | ||
680 | for (signo = 1; signo < NSIG; signo++) | |
681 | { | |
2ea28649 | 682 | int target_signo = gdb_signal_from_host (signo); |
2455069d UW |
683 | if (target_signo < numsigs && pass_signals[target_signo]) |
684 | sigaddset (&pass_mask, signo); | |
685 | } | |
686 | } | |
687 | ||
d6b0e80f AC |
688 | \f |
689 | ||
690 | /* Prototypes for local functions. */ | |
691 | static int stop_wait_callback (struct lwp_info *lp, void *data); | |
28439f5e | 692 | static int linux_thread_alive (ptid_t ptid); |
8dd27370 | 693 | static char *linux_child_pid_to_exec_file (struct target_ops *self, int pid); |
710151dd | 694 | |
d6b0e80f | 695 | \f |
d6b0e80f | 696 | |
7b50312a PA |
697 | /* Destroy and free LP. */ |
698 | ||
699 | static void | |
700 | lwp_free (struct lwp_info *lp) | |
701 | { | |
702 | xfree (lp->arch_private); | |
703 | xfree (lp); | |
704 | } | |
705 | ||
d90e17a7 PA |
706 | /* Remove all LWPs belong to PID from the lwp list. */ |
707 | ||
708 | static void | |
709 | purge_lwp_list (int pid) | |
710 | { | |
711 | struct lwp_info *lp, *lpprev, *lpnext; | |
712 | ||
713 | lpprev = NULL; | |
714 | ||
715 | for (lp = lwp_list; lp; lp = lpnext) | |
716 | { | |
717 | lpnext = lp->next; | |
718 | ||
719 | if (ptid_get_pid (lp->ptid) == pid) | |
720 | { | |
721 | if (lp == lwp_list) | |
722 | lwp_list = lp->next; | |
723 | else | |
724 | lpprev->next = lp->next; | |
725 | ||
7b50312a | 726 | lwp_free (lp); |
d90e17a7 PA |
727 | } |
728 | else | |
729 | lpprev = lp; | |
730 | } | |
731 | } | |
732 | ||
26cb8b7c PA |
733 | /* Add the LWP specified by PTID to the list. PTID is the first LWP |
734 | in the process. Return a pointer to the structure describing the | |
735 | new LWP. | |
736 | ||
737 | This differs from add_lwp in that we don't let the arch specific | |
738 | bits know about this new thread. Current clients of this callback | |
739 | take the opportunity to install watchpoints in the new thread, and | |
740 | we shouldn't do that for the first thread. If we're spawning a | |
741 | child ("run"), the thread executes the shell wrapper first, and we | |
742 | shouldn't touch it until it execs the program we want to debug. | |
743 | For "attach", it'd be okay to call the callback, but it's not | |
744 | necessary, because watchpoints can't yet have been inserted into | |
745 | the inferior. */ | |
d6b0e80f AC |
746 | |
747 | static struct lwp_info * | |
26cb8b7c | 748 | add_initial_lwp (ptid_t ptid) |
d6b0e80f AC |
749 | { |
750 | struct lwp_info *lp; | |
751 | ||
dfd4cc63 | 752 | gdb_assert (ptid_lwp_p (ptid)); |
d6b0e80f AC |
753 | |
754 | lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info)); | |
755 | ||
756 | memset (lp, 0, sizeof (struct lwp_info)); | |
757 | ||
25289eb2 | 758 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
759 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
760 | ||
761 | lp->ptid = ptid; | |
dc146f7c | 762 | lp->core = -1; |
d6b0e80f AC |
763 | |
764 | lp->next = lwp_list; | |
765 | lwp_list = lp; | |
d6b0e80f | 766 | |
26cb8b7c PA |
767 | return lp; |
768 | } | |
769 | ||
770 | /* Add the LWP specified by PID to the list. Return a pointer to the | |
771 | structure describing the new LWP. The LWP should already be | |
772 | stopped. */ | |
773 | ||
774 | static struct lwp_info * | |
775 | add_lwp (ptid_t ptid) | |
776 | { | |
777 | struct lwp_info *lp; | |
778 | ||
779 | lp = add_initial_lwp (ptid); | |
780 | ||
6e012a6c PA |
781 | /* Let the arch specific bits know about this new thread. Current |
782 | clients of this callback take the opportunity to install | |
26cb8b7c PA |
783 | watchpoints in the new thread. We don't do this for the first |
784 | thread though. See add_initial_lwp. */ | |
785 | if (linux_nat_new_thread != NULL) | |
7b50312a | 786 | linux_nat_new_thread (lp); |
9f0bdab8 | 787 | |
d6b0e80f AC |
788 | return lp; |
789 | } | |
790 | ||
791 | /* Remove the LWP specified by PID from the list. */ | |
792 | ||
793 | static void | |
794 | delete_lwp (ptid_t ptid) | |
795 | { | |
796 | struct lwp_info *lp, *lpprev; | |
797 | ||
798 | lpprev = NULL; | |
799 | ||
800 | for (lp = lwp_list; lp; lpprev = lp, lp = lp->next) | |
801 | if (ptid_equal (lp->ptid, ptid)) | |
802 | break; | |
803 | ||
804 | if (!lp) | |
805 | return; | |
806 | ||
d6b0e80f AC |
807 | if (lpprev) |
808 | lpprev->next = lp->next; | |
809 | else | |
810 | lwp_list = lp->next; | |
811 | ||
7b50312a | 812 | lwp_free (lp); |
d6b0e80f AC |
813 | } |
814 | ||
815 | /* Return a pointer to the structure describing the LWP corresponding | |
816 | to PID. If no corresponding LWP could be found, return NULL. */ | |
817 | ||
818 | static struct lwp_info * | |
819 | find_lwp_pid (ptid_t ptid) | |
820 | { | |
821 | struct lwp_info *lp; | |
822 | int lwp; | |
823 | ||
dfd4cc63 LM |
824 | if (ptid_lwp_p (ptid)) |
825 | lwp = ptid_get_lwp (ptid); | |
d6b0e80f | 826 | else |
dfd4cc63 | 827 | lwp = ptid_get_pid (ptid); |
d6b0e80f AC |
828 | |
829 | for (lp = lwp_list; lp; lp = lp->next) | |
dfd4cc63 | 830 | if (lwp == ptid_get_lwp (lp->ptid)) |
d6b0e80f AC |
831 | return lp; |
832 | ||
833 | return NULL; | |
834 | } | |
835 | ||
836 | /* Call CALLBACK with its second argument set to DATA for every LWP in | |
837 | the list. If CALLBACK returns 1 for a particular LWP, return a | |
838 | pointer to the structure describing that LWP immediately. | |
839 | Otherwise return NULL. */ | |
840 | ||
841 | struct lwp_info * | |
d90e17a7 PA |
842 | iterate_over_lwps (ptid_t filter, |
843 | int (*callback) (struct lwp_info *, void *), | |
844 | void *data) | |
d6b0e80f AC |
845 | { |
846 | struct lwp_info *lp, *lpnext; | |
847 | ||
848 | for (lp = lwp_list; lp; lp = lpnext) | |
849 | { | |
850 | lpnext = lp->next; | |
d90e17a7 PA |
851 | |
852 | if (ptid_match (lp->ptid, filter)) | |
853 | { | |
854 | if ((*callback) (lp, data)) | |
855 | return lp; | |
856 | } | |
d6b0e80f AC |
857 | } |
858 | ||
859 | return NULL; | |
860 | } | |
861 | ||
2277426b PA |
862 | /* Update our internal state when changing from one checkpoint to |
863 | another indicated by NEW_PTID. We can only switch single-threaded | |
864 | applications, so we only create one new LWP, and the previous list | |
865 | is discarded. */ | |
f973ed9c DJ |
866 | |
867 | void | |
868 | linux_nat_switch_fork (ptid_t new_ptid) | |
869 | { | |
870 | struct lwp_info *lp; | |
871 | ||
dfd4cc63 | 872 | purge_lwp_list (ptid_get_pid (inferior_ptid)); |
2277426b | 873 | |
f973ed9c DJ |
874 | lp = add_lwp (new_ptid); |
875 | lp->stopped = 1; | |
e26af52f | 876 | |
2277426b PA |
877 | /* This changes the thread's ptid while preserving the gdb thread |
878 | num. Also changes the inferior pid, while preserving the | |
879 | inferior num. */ | |
880 | thread_change_ptid (inferior_ptid, new_ptid); | |
881 | ||
882 | /* We've just told GDB core that the thread changed target id, but, | |
883 | in fact, it really is a different thread, with different register | |
884 | contents. */ | |
885 | registers_changed (); | |
e26af52f DJ |
886 | } |
887 | ||
e26af52f DJ |
888 | /* Handle the exit of a single thread LP. */ |
889 | ||
890 | static void | |
891 | exit_lwp (struct lwp_info *lp) | |
892 | { | |
e09875d4 | 893 | struct thread_info *th = find_thread_ptid (lp->ptid); |
063bfe2e VP |
894 | |
895 | if (th) | |
e26af52f | 896 | { |
17faa917 DJ |
897 | if (print_thread_events) |
898 | printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid)); | |
899 | ||
4f8d22e3 | 900 | delete_thread (lp->ptid); |
e26af52f DJ |
901 | } |
902 | ||
903 | delete_lwp (lp->ptid); | |
904 | } | |
905 | ||
a0ef4274 DJ |
906 | /* Wait for the LWP specified by LP, which we have just attached to. |
907 | Returns a wait status for that LWP, to cache. */ | |
908 | ||
909 | static int | |
910 | linux_nat_post_attach_wait (ptid_t ptid, int first, int *cloned, | |
911 | int *signalled) | |
912 | { | |
dfd4cc63 | 913 | pid_t new_pid, pid = ptid_get_lwp (ptid); |
a0ef4274 DJ |
914 | int status; |
915 | ||
644cebc9 | 916 | if (linux_proc_pid_is_stopped (pid)) |
a0ef4274 DJ |
917 | { |
918 | if (debug_linux_nat) | |
919 | fprintf_unfiltered (gdb_stdlog, | |
920 | "LNPAW: Attaching to a stopped process\n"); | |
921 | ||
922 | /* The process is definitely stopped. It is in a job control | |
923 | stop, unless the kernel predates the TASK_STOPPED / | |
924 | TASK_TRACED distinction, in which case it might be in a | |
925 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
926 | can kill it, signal it, et cetera. | |
927 | ||
928 | First make sure there is a pending SIGSTOP. Since we are | |
929 | already attached, the process can not transition from stopped | |
930 | to running without a PTRACE_CONT; so we know this signal will | |
931 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
932 | probably already in the queue (unless this kernel is old | |
933 | enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP | |
934 | is not an RT signal, it can only be queued once. */ | |
935 | kill_lwp (pid, SIGSTOP); | |
936 | ||
937 | /* Finally, resume the stopped process. This will deliver the SIGSTOP | |
938 | (or a higher priority signal, just like normal PTRACE_ATTACH). */ | |
939 | ptrace (PTRACE_CONT, pid, 0, 0); | |
940 | } | |
941 | ||
942 | /* Make sure the initial process is stopped. The user-level threads | |
943 | layer might want to poke around in the inferior, and that won't | |
944 | work if things haven't stabilized yet. */ | |
945 | new_pid = my_waitpid (pid, &status, 0); | |
946 | if (new_pid == -1 && errno == ECHILD) | |
947 | { | |
948 | if (first) | |
949 | warning (_("%s is a cloned process"), target_pid_to_str (ptid)); | |
950 | ||
951 | /* Try again with __WCLONE to check cloned processes. */ | |
952 | new_pid = my_waitpid (pid, &status, __WCLONE); | |
953 | *cloned = 1; | |
954 | } | |
955 | ||
dacc9cb2 PP |
956 | gdb_assert (pid == new_pid); |
957 | ||
958 | if (!WIFSTOPPED (status)) | |
959 | { | |
960 | /* The pid we tried to attach has apparently just exited. */ | |
961 | if (debug_linux_nat) | |
962 | fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s", | |
963 | pid, status_to_str (status)); | |
964 | return status; | |
965 | } | |
a0ef4274 DJ |
966 | |
967 | if (WSTOPSIG (status) != SIGSTOP) | |
968 | { | |
969 | *signalled = 1; | |
970 | if (debug_linux_nat) | |
971 | fprintf_unfiltered (gdb_stdlog, | |
972 | "LNPAW: Received %s after attaching\n", | |
973 | status_to_str (status)); | |
974 | } | |
975 | ||
976 | return status; | |
977 | } | |
978 | ||
84636d28 PA |
979 | /* Attach to the LWP specified by PID. Return 0 if successful, -1 if |
980 | the new LWP could not be attached, or 1 if we're already auto | |
981 | attached to this thread, but haven't processed the | |
982 | PTRACE_EVENT_CLONE event of its parent thread, so we just ignore | |
983 | its existance, without considering it an error. */ | |
d6b0e80f | 984 | |
9ee57c33 | 985 | int |
93815fbf | 986 | lin_lwp_attach_lwp (ptid_t ptid) |
d6b0e80f | 987 | { |
9ee57c33 | 988 | struct lwp_info *lp; |
84636d28 | 989 | int lwpid; |
d6b0e80f | 990 | |
dfd4cc63 | 991 | gdb_assert (ptid_lwp_p (ptid)); |
d6b0e80f | 992 | |
9ee57c33 | 993 | lp = find_lwp_pid (ptid); |
dfd4cc63 | 994 | lwpid = ptid_get_lwp (ptid); |
d6b0e80f AC |
995 | |
996 | /* We assume that we're already attached to any LWP that has an id | |
997 | equal to the overall process id, and to any LWP that is already | |
998 | in our list of LWPs. If we're not seeing exit events from threads | |
999 | and we've had PID wraparound since we last tried to stop all threads, | |
1000 | this assumption might be wrong; fortunately, this is very unlikely | |
1001 | to happen. */ | |
dfd4cc63 | 1002 | if (lwpid != ptid_get_pid (ptid) && lp == NULL) |
d6b0e80f | 1003 | { |
a0ef4274 | 1004 | int status, cloned = 0, signalled = 0; |
d6b0e80f | 1005 | |
84636d28 | 1006 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) |
9ee57c33 | 1007 | { |
96d7229d | 1008 | if (linux_supports_tracefork ()) |
84636d28 PA |
1009 | { |
1010 | /* If we haven't stopped all threads when we get here, | |
1011 | we may have seen a thread listed in thread_db's list, | |
1012 | but not processed the PTRACE_EVENT_CLONE yet. If | |
1013 | that's the case, ignore this new thread, and let | |
1014 | normal event handling discover it later. */ | |
1015 | if (in_pid_list_p (stopped_pids, lwpid)) | |
1016 | { | |
1017 | /* We've already seen this thread stop, but we | |
1018 | haven't seen the PTRACE_EVENT_CLONE extended | |
1019 | event yet. */ | |
84636d28 PA |
1020 | return 0; |
1021 | } | |
1022 | else | |
1023 | { | |
1024 | int new_pid; | |
1025 | int status; | |
1026 | ||
1027 | /* See if we've got a stop for this new child | |
1028 | pending. If so, we're already attached. */ | |
a33e3959 | 1029 | gdb_assert (lwpid > 0); |
84636d28 PA |
1030 | new_pid = my_waitpid (lwpid, &status, WNOHANG); |
1031 | if (new_pid == -1 && errno == ECHILD) | |
1032 | new_pid = my_waitpid (lwpid, &status, __WCLONE | WNOHANG); | |
1033 | if (new_pid != -1) | |
1034 | { | |
1035 | if (WIFSTOPPED (status)) | |
1036 | add_to_pid_list (&stopped_pids, lwpid, status); | |
84636d28 PA |
1037 | return 1; |
1038 | } | |
1039 | } | |
1040 | } | |
1041 | ||
9ee57c33 DJ |
1042 | /* If we fail to attach to the thread, issue a warning, |
1043 | but continue. One way this can happen is if thread | |
e9efe249 | 1044 | creation is interrupted; as of Linux kernel 2.6.19, a |
9ee57c33 DJ |
1045 | bug may place threads in the thread list and then fail |
1046 | to create them. */ | |
1047 | warning (_("Can't attach %s: %s"), target_pid_to_str (ptid), | |
1048 | safe_strerror (errno)); | |
1049 | return -1; | |
1050 | } | |
1051 | ||
d6b0e80f AC |
1052 | if (debug_linux_nat) |
1053 | fprintf_unfiltered (gdb_stdlog, | |
1054 | "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n", | |
1055 | target_pid_to_str (ptid)); | |
1056 | ||
a0ef4274 | 1057 | status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled); |
dacc9cb2 | 1058 | if (!WIFSTOPPED (status)) |
12696c10 | 1059 | return 1; |
dacc9cb2 | 1060 | |
a0ef4274 DJ |
1061 | lp = add_lwp (ptid); |
1062 | lp->stopped = 1; | |
1063 | lp->cloned = cloned; | |
1064 | lp->signalled = signalled; | |
1065 | if (WSTOPSIG (status) != SIGSTOP) | |
d6b0e80f | 1066 | { |
a0ef4274 DJ |
1067 | lp->resumed = 1; |
1068 | lp->status = status; | |
d6b0e80f AC |
1069 | } |
1070 | ||
dfd4cc63 | 1071 | target_post_attach (ptid_get_lwp (lp->ptid)); |
d6b0e80f AC |
1072 | |
1073 | if (debug_linux_nat) | |
1074 | { | |
1075 | fprintf_unfiltered (gdb_stdlog, | |
1076 | "LLAL: waitpid %s received %s\n", | |
1077 | target_pid_to_str (ptid), | |
1078 | status_to_str (status)); | |
1079 | } | |
1080 | } | |
1081 | else | |
1082 | { | |
1083 | /* We assume that the LWP representing the original process is | |
1084 | already stopped. Mark it as stopped in the data structure | |
155bd5d1 AC |
1085 | that the GNU/linux ptrace layer uses to keep track of |
1086 | threads. Note that this won't have already been done since | |
1087 | the main thread will have, we assume, been stopped by an | |
1088 | attach from a different layer. */ | |
9ee57c33 DJ |
1089 | if (lp == NULL) |
1090 | lp = add_lwp (ptid); | |
d6b0e80f AC |
1091 | lp->stopped = 1; |
1092 | } | |
9ee57c33 | 1093 | |
25289eb2 | 1094 | lp->last_resume_kind = resume_stop; |
9ee57c33 | 1095 | return 0; |
d6b0e80f AC |
1096 | } |
1097 | ||
b84876c2 | 1098 | static void |
136d6dae VP |
1099 | linux_nat_create_inferior (struct target_ops *ops, |
1100 | char *exec_file, char *allargs, char **env, | |
b84876c2 PA |
1101 | int from_tty) |
1102 | { | |
8cc73a39 SDJ |
1103 | struct cleanup *restore_personality |
1104 | = maybe_disable_address_space_randomization (disable_randomization); | |
b84876c2 PA |
1105 | |
1106 | /* The fork_child mechanism is synchronous and calls target_wait, so | |
1107 | we have to mask the async mode. */ | |
1108 | ||
2455069d | 1109 | /* Make sure we report all signals during startup. */ |
94bedb42 | 1110 | linux_nat_pass_signals (ops, 0, NULL); |
2455069d | 1111 | |
136d6dae | 1112 | linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty); |
b84876c2 | 1113 | |
8cc73a39 | 1114 | do_cleanups (restore_personality); |
b84876c2 PA |
1115 | } |
1116 | ||
8784d563 PA |
1117 | /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not |
1118 | already attached. Returns true if a new LWP is found, false | |
1119 | otherwise. */ | |
1120 | ||
1121 | static int | |
1122 | attach_proc_task_lwp_callback (ptid_t ptid) | |
1123 | { | |
1124 | struct lwp_info *lp; | |
1125 | ||
1126 | /* Ignore LWPs we're already attached to. */ | |
1127 | lp = find_lwp_pid (ptid); | |
1128 | if (lp == NULL) | |
1129 | { | |
1130 | int lwpid = ptid_get_lwp (ptid); | |
1131 | ||
1132 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) | |
1133 | { | |
1134 | int err = errno; | |
1135 | ||
1136 | /* Be quiet if we simply raced with the thread exiting. | |
1137 | EPERM is returned if the thread's task still exists, and | |
1138 | is marked as exited or zombie, as well as other | |
1139 | conditions, so in that case, confirm the status in | |
1140 | /proc/PID/status. */ | |
1141 | if (err == ESRCH | |
1142 | || (err == EPERM && linux_proc_pid_is_gone (lwpid))) | |
1143 | { | |
1144 | if (debug_linux_nat) | |
1145 | { | |
1146 | fprintf_unfiltered (gdb_stdlog, | |
1147 | "Cannot attach to lwp %d: " | |
1148 | "thread is gone (%d: %s)\n", | |
1149 | lwpid, err, safe_strerror (err)); | |
1150 | } | |
1151 | } | |
1152 | else | |
1153 | { | |
f71f0b0d | 1154 | warning (_("Cannot attach to lwp %d: %s"), |
8784d563 PA |
1155 | lwpid, |
1156 | linux_ptrace_attach_fail_reason_string (ptid, | |
1157 | err)); | |
1158 | } | |
1159 | } | |
1160 | else | |
1161 | { | |
1162 | if (debug_linux_nat) | |
1163 | fprintf_unfiltered (gdb_stdlog, | |
1164 | "PTRACE_ATTACH %s, 0, 0 (OK)\n", | |
1165 | target_pid_to_str (ptid)); | |
1166 | ||
1167 | lp = add_lwp (ptid); | |
1168 | lp->cloned = 1; | |
1169 | ||
1170 | /* The next time we wait for this LWP we'll see a SIGSTOP as | |
1171 | PTRACE_ATTACH brings it to a halt. */ | |
1172 | lp->signalled = 1; | |
1173 | ||
1174 | /* We need to wait for a stop before being able to make the | |
1175 | next ptrace call on this LWP. */ | |
1176 | lp->must_set_ptrace_flags = 1; | |
1177 | } | |
1178 | ||
1179 | return 1; | |
1180 | } | |
1181 | return 0; | |
1182 | } | |
1183 | ||
d6b0e80f | 1184 | static void |
c0939df1 | 1185 | linux_nat_attach (struct target_ops *ops, const char *args, int from_tty) |
d6b0e80f AC |
1186 | { |
1187 | struct lwp_info *lp; | |
d6b0e80f | 1188 | int status; |
af990527 | 1189 | ptid_t ptid; |
87b0bb13 | 1190 | volatile struct gdb_exception ex; |
d6b0e80f | 1191 | |
2455069d | 1192 | /* Make sure we report all signals during attach. */ |
94bedb42 | 1193 | linux_nat_pass_signals (ops, 0, NULL); |
2455069d | 1194 | |
87b0bb13 JK |
1195 | TRY_CATCH (ex, RETURN_MASK_ERROR) |
1196 | { | |
1197 | linux_ops->to_attach (ops, args, from_tty); | |
1198 | } | |
1199 | if (ex.reason < 0) | |
1200 | { | |
1201 | pid_t pid = parse_pid_to_attach (args); | |
1202 | struct buffer buffer; | |
1203 | char *message, *buffer_s; | |
1204 | ||
1205 | message = xstrdup (ex.message); | |
1206 | make_cleanup (xfree, message); | |
1207 | ||
1208 | buffer_init (&buffer); | |
7ae1a6a6 | 1209 | linux_ptrace_attach_fail_reason (pid, &buffer); |
87b0bb13 JK |
1210 | |
1211 | buffer_grow_str0 (&buffer, ""); | |
1212 | buffer_s = buffer_finish (&buffer); | |
1213 | make_cleanup (xfree, buffer_s); | |
1214 | ||
7ae1a6a6 PA |
1215 | if (*buffer_s != '\0') |
1216 | throw_error (ex.error, "warning: %s\n%s", buffer_s, message); | |
1217 | else | |
1218 | throw_error (ex.error, "%s", message); | |
87b0bb13 | 1219 | } |
d6b0e80f | 1220 | |
af990527 PA |
1221 | /* The ptrace base target adds the main thread with (pid,0,0) |
1222 | format. Decorate it with lwp info. */ | |
dfd4cc63 LM |
1223 | ptid = ptid_build (ptid_get_pid (inferior_ptid), |
1224 | ptid_get_pid (inferior_ptid), | |
1225 | 0); | |
af990527 PA |
1226 | thread_change_ptid (inferior_ptid, ptid); |
1227 | ||
9f0bdab8 | 1228 | /* Add the initial process as the first LWP to the list. */ |
26cb8b7c | 1229 | lp = add_initial_lwp (ptid); |
a0ef4274 DJ |
1230 | |
1231 | status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->cloned, | |
1232 | &lp->signalled); | |
dacc9cb2 PP |
1233 | if (!WIFSTOPPED (status)) |
1234 | { | |
1235 | if (WIFEXITED (status)) | |
1236 | { | |
1237 | int exit_code = WEXITSTATUS (status); | |
1238 | ||
1239 | target_terminal_ours (); | |
1240 | target_mourn_inferior (); | |
1241 | if (exit_code == 0) | |
1242 | error (_("Unable to attach: program exited normally.")); | |
1243 | else | |
1244 | error (_("Unable to attach: program exited with code %d."), | |
1245 | exit_code); | |
1246 | } | |
1247 | else if (WIFSIGNALED (status)) | |
1248 | { | |
2ea28649 | 1249 | enum gdb_signal signo; |
dacc9cb2 PP |
1250 | |
1251 | target_terminal_ours (); | |
1252 | target_mourn_inferior (); | |
1253 | ||
2ea28649 | 1254 | signo = gdb_signal_from_host (WTERMSIG (status)); |
dacc9cb2 PP |
1255 | error (_("Unable to attach: program terminated with signal " |
1256 | "%s, %s."), | |
2ea28649 PA |
1257 | gdb_signal_to_name (signo), |
1258 | gdb_signal_to_string (signo)); | |
dacc9cb2 PP |
1259 | } |
1260 | ||
1261 | internal_error (__FILE__, __LINE__, | |
1262 | _("unexpected status %d for PID %ld"), | |
dfd4cc63 | 1263 | status, (long) ptid_get_lwp (ptid)); |
dacc9cb2 PP |
1264 | } |
1265 | ||
a0ef4274 | 1266 | lp->stopped = 1; |
9f0bdab8 | 1267 | |
a0ef4274 | 1268 | /* Save the wait status to report later. */ |
d6b0e80f | 1269 | lp->resumed = 1; |
a0ef4274 DJ |
1270 | if (debug_linux_nat) |
1271 | fprintf_unfiltered (gdb_stdlog, | |
1272 | "LNA: waitpid %ld, saving status %s\n", | |
dfd4cc63 | 1273 | (long) ptid_get_pid (lp->ptid), status_to_str (status)); |
710151dd | 1274 | |
7feb7d06 PA |
1275 | lp->status = status; |
1276 | ||
8784d563 PA |
1277 | /* We must attach to every LWP. If /proc is mounted, use that to |
1278 | find them now. The inferior may be using raw clone instead of | |
1279 | using pthreads. But even if it is using pthreads, thread_db | |
1280 | walks structures in the inferior's address space to find the list | |
1281 | of threads/LWPs, and those structures may well be corrupted. | |
1282 | Note that once thread_db is loaded, we'll still use it to list | |
1283 | threads and associate pthread info with each LWP. */ | |
1284 | linux_proc_attach_tgid_threads (ptid_get_pid (lp->ptid), | |
1285 | attach_proc_task_lwp_callback); | |
1286 | ||
7feb7d06 PA |
1287 | if (target_can_async_p ()) |
1288 | target_async (inferior_event_handler, 0); | |
d6b0e80f AC |
1289 | } |
1290 | ||
a0ef4274 DJ |
1291 | /* Get pending status of LP. */ |
1292 | static int | |
1293 | get_pending_status (struct lwp_info *lp, int *status) | |
1294 | { | |
a493e3e2 | 1295 | enum gdb_signal signo = GDB_SIGNAL_0; |
ca2163eb PA |
1296 | |
1297 | /* If we paused threads momentarily, we may have stored pending | |
1298 | events in lp->status or lp->waitstatus (see stop_wait_callback), | |
1299 | and GDB core hasn't seen any signal for those threads. | |
1300 | Otherwise, the last signal reported to the core is found in the | |
1301 | thread object's stop_signal. | |
1302 | ||
1303 | There's a corner case that isn't handled here at present. Only | |
1304 | if the thread stopped with a TARGET_WAITKIND_STOPPED does | |
1305 | stop_signal make sense as a real signal to pass to the inferior. | |
1306 | Some catchpoint related events, like | |
1307 | TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set | |
a493e3e2 | 1308 | to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But, |
ca2163eb PA |
1309 | those traps are debug API (ptrace in our case) related and |
1310 | induced; the inferior wouldn't see them if it wasn't being | |
1311 | traced. Hence, we should never pass them to the inferior, even | |
1312 | when set to pass state. Since this corner case isn't handled by | |
1313 | infrun.c when proceeding with a signal, for consistency, neither | |
1314 | do we handle it here (or elsewhere in the file we check for | |
1315 | signal pass state). Normally SIGTRAP isn't set to pass state, so | |
1316 | this is really a corner case. */ | |
1317 | ||
1318 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
a493e3e2 | 1319 | signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */ |
ca2163eb | 1320 | else if (lp->status) |
2ea28649 | 1321 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
ca2163eb PA |
1322 | else if (non_stop && !is_executing (lp->ptid)) |
1323 | { | |
1324 | struct thread_info *tp = find_thread_ptid (lp->ptid); | |
e0881a8e | 1325 | |
16c381f0 | 1326 | signo = tp->suspend.stop_signal; |
ca2163eb PA |
1327 | } |
1328 | else if (!non_stop) | |
a0ef4274 | 1329 | { |
ca2163eb PA |
1330 | struct target_waitstatus last; |
1331 | ptid_t last_ptid; | |
4c28f408 | 1332 | |
ca2163eb | 1333 | get_last_target_status (&last_ptid, &last); |
4c28f408 | 1334 | |
dfd4cc63 | 1335 | if (ptid_get_lwp (lp->ptid) == ptid_get_lwp (last_ptid)) |
ca2163eb | 1336 | { |
e09875d4 | 1337 | struct thread_info *tp = find_thread_ptid (lp->ptid); |
e0881a8e | 1338 | |
16c381f0 | 1339 | signo = tp->suspend.stop_signal; |
4c28f408 | 1340 | } |
ca2163eb | 1341 | } |
4c28f408 | 1342 | |
ca2163eb | 1343 | *status = 0; |
4c28f408 | 1344 | |
a493e3e2 | 1345 | if (signo == GDB_SIGNAL_0) |
ca2163eb PA |
1346 | { |
1347 | if (debug_linux_nat) | |
1348 | fprintf_unfiltered (gdb_stdlog, | |
1349 | "GPT: lwp %s has no pending signal\n", | |
1350 | target_pid_to_str (lp->ptid)); | |
1351 | } | |
1352 | else if (!signal_pass_state (signo)) | |
1353 | { | |
1354 | if (debug_linux_nat) | |
3e43a32a MS |
1355 | fprintf_unfiltered (gdb_stdlog, |
1356 | "GPT: lwp %s had signal %s, " | |
1357 | "but it is in no pass state\n", | |
ca2163eb | 1358 | target_pid_to_str (lp->ptid), |
2ea28649 | 1359 | gdb_signal_to_string (signo)); |
a0ef4274 | 1360 | } |
a0ef4274 | 1361 | else |
4c28f408 | 1362 | { |
2ea28649 | 1363 | *status = W_STOPCODE (gdb_signal_to_host (signo)); |
ca2163eb PA |
1364 | |
1365 | if (debug_linux_nat) | |
1366 | fprintf_unfiltered (gdb_stdlog, | |
1367 | "GPT: lwp %s has pending signal %s\n", | |
1368 | target_pid_to_str (lp->ptid), | |
2ea28649 | 1369 | gdb_signal_to_string (signo)); |
4c28f408 | 1370 | } |
a0ef4274 DJ |
1371 | |
1372 | return 0; | |
1373 | } | |
1374 | ||
d6b0e80f AC |
1375 | static int |
1376 | detach_callback (struct lwp_info *lp, void *data) | |
1377 | { | |
1378 | gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status)); | |
1379 | ||
1380 | if (debug_linux_nat && lp->status) | |
1381 | fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n", | |
1382 | strsignal (WSTOPSIG (lp->status)), | |
1383 | target_pid_to_str (lp->ptid)); | |
1384 | ||
a0ef4274 DJ |
1385 | /* If there is a pending SIGSTOP, get rid of it. */ |
1386 | if (lp->signalled) | |
d6b0e80f | 1387 | { |
d6b0e80f AC |
1388 | if (debug_linux_nat) |
1389 | fprintf_unfiltered (gdb_stdlog, | |
a0ef4274 DJ |
1390 | "DC: Sending SIGCONT to %s\n", |
1391 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 1392 | |
dfd4cc63 | 1393 | kill_lwp (ptid_get_lwp (lp->ptid), SIGCONT); |
d6b0e80f | 1394 | lp->signalled = 0; |
d6b0e80f AC |
1395 | } |
1396 | ||
1397 | /* We don't actually detach from the LWP that has an id equal to the | |
1398 | overall process id just yet. */ | |
dfd4cc63 | 1399 | if (ptid_get_lwp (lp->ptid) != ptid_get_pid (lp->ptid)) |
d6b0e80f | 1400 | { |
a0ef4274 DJ |
1401 | int status = 0; |
1402 | ||
1403 | /* Pass on any pending signal for this LWP. */ | |
1404 | get_pending_status (lp, &status); | |
1405 | ||
7b50312a PA |
1406 | if (linux_nat_prepare_to_resume != NULL) |
1407 | linux_nat_prepare_to_resume (lp); | |
d6b0e80f | 1408 | errno = 0; |
dfd4cc63 | 1409 | if (ptrace (PTRACE_DETACH, ptid_get_lwp (lp->ptid), 0, |
a0ef4274 | 1410 | WSTOPSIG (status)) < 0) |
8a3fe4f8 | 1411 | error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid), |
d6b0e80f AC |
1412 | safe_strerror (errno)); |
1413 | ||
1414 | if (debug_linux_nat) | |
1415 | fprintf_unfiltered (gdb_stdlog, | |
1416 | "PTRACE_DETACH (%s, %s, 0) (OK)\n", | |
1417 | target_pid_to_str (lp->ptid), | |
7feb7d06 | 1418 | strsignal (WSTOPSIG (status))); |
d6b0e80f AC |
1419 | |
1420 | delete_lwp (lp->ptid); | |
1421 | } | |
1422 | ||
1423 | return 0; | |
1424 | } | |
1425 | ||
1426 | static void | |
52554a0e | 1427 | linux_nat_detach (struct target_ops *ops, const char *args, int from_tty) |
d6b0e80f | 1428 | { |
b84876c2 | 1429 | int pid; |
a0ef4274 | 1430 | int status; |
d90e17a7 PA |
1431 | struct lwp_info *main_lwp; |
1432 | ||
dfd4cc63 | 1433 | pid = ptid_get_pid (inferior_ptid); |
a0ef4274 | 1434 | |
ae5e0686 MK |
1435 | /* Don't unregister from the event loop, as there may be other |
1436 | inferiors running. */ | |
b84876c2 | 1437 | |
4c28f408 PA |
1438 | /* Stop all threads before detaching. ptrace requires that the |
1439 | thread is stopped to sucessfully detach. */ | |
d90e17a7 | 1440 | iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL); |
4c28f408 PA |
1441 | /* ... and wait until all of them have reported back that |
1442 | they're no longer running. */ | |
d90e17a7 | 1443 | iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL); |
4c28f408 | 1444 | |
d90e17a7 | 1445 | iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL); |
d6b0e80f AC |
1446 | |
1447 | /* Only the initial process should be left right now. */ | |
dfd4cc63 | 1448 | gdb_assert (num_lwps (ptid_get_pid (inferior_ptid)) == 1); |
d90e17a7 PA |
1449 | |
1450 | main_lwp = find_lwp_pid (pid_to_ptid (pid)); | |
d6b0e80f | 1451 | |
a0ef4274 DJ |
1452 | /* Pass on any pending signal for the last LWP. */ |
1453 | if ((args == NULL || *args == '\0') | |
d90e17a7 | 1454 | && get_pending_status (main_lwp, &status) != -1 |
a0ef4274 DJ |
1455 | && WIFSTOPPED (status)) |
1456 | { | |
52554a0e TT |
1457 | char *tem; |
1458 | ||
a0ef4274 DJ |
1459 | /* Put the signal number in ARGS so that inf_ptrace_detach will |
1460 | pass it along with PTRACE_DETACH. */ | |
52554a0e | 1461 | tem = alloca (8); |
cde33bf1 | 1462 | xsnprintf (tem, 8, "%d", (int) WSTOPSIG (status)); |
52554a0e | 1463 | args = tem; |
ddabfc73 TT |
1464 | if (debug_linux_nat) |
1465 | fprintf_unfiltered (gdb_stdlog, | |
1466 | "LND: Sending signal %s to %s\n", | |
1467 | args, | |
1468 | target_pid_to_str (main_lwp->ptid)); | |
a0ef4274 DJ |
1469 | } |
1470 | ||
7b50312a PA |
1471 | if (linux_nat_prepare_to_resume != NULL) |
1472 | linux_nat_prepare_to_resume (main_lwp); | |
d90e17a7 | 1473 | delete_lwp (main_lwp->ptid); |
b84876c2 | 1474 | |
7a7d3353 PA |
1475 | if (forks_exist_p ()) |
1476 | { | |
1477 | /* Multi-fork case. The current inferior_ptid is being detached | |
1478 | from, but there are other viable forks to debug. Detach from | |
1479 | the current fork, and context-switch to the first | |
1480 | available. */ | |
1481 | linux_fork_detach (args, from_tty); | |
7a7d3353 PA |
1482 | } |
1483 | else | |
1484 | linux_ops->to_detach (ops, args, from_tty); | |
d6b0e80f AC |
1485 | } |
1486 | ||
8a99810d PA |
1487 | /* Resume execution of the inferior process. If STEP is nonzero, |
1488 | single-step it. If SIGNAL is nonzero, give it that signal. */ | |
1489 | ||
1490 | static void | |
1491 | linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) | |
1492 | { | |
1493 | ptid_t ptid; | |
1494 | ||
1495 | lp->step = step; | |
9c02b525 PA |
1496 | |
1497 | /* stop_pc doubles as the PC the LWP had when it was last resumed. | |
1498 | We only presently need that if the LWP is stepped though (to | |
1499 | handle the case of stepping a breakpoint instruction). */ | |
1500 | if (step) | |
1501 | { | |
1502 | struct regcache *regcache = get_thread_regcache (lp->ptid); | |
1503 | ||
1504 | lp->stop_pc = regcache_read_pc (regcache); | |
1505 | } | |
1506 | else | |
1507 | lp->stop_pc = 0; | |
1508 | ||
8a99810d PA |
1509 | if (linux_nat_prepare_to_resume != NULL) |
1510 | linux_nat_prepare_to_resume (lp); | |
1511 | /* Convert to something the lower layer understands. */ | |
1512 | ptid = pid_to_ptid (ptid_get_lwp (lp->ptid)); | |
1513 | linux_ops->to_resume (linux_ops, ptid, step, signo); | |
9c02b525 | 1514 | lp->stop_reason = LWP_STOPPED_BY_NO_REASON; |
8a99810d PA |
1515 | lp->stopped = 0; |
1516 | registers_changed_ptid (lp->ptid); | |
1517 | } | |
1518 | ||
d6b0e80f AC |
1519 | /* Resume LP. */ |
1520 | ||
25289eb2 | 1521 | static void |
e5ef252a | 1522 | resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) |
d6b0e80f | 1523 | { |
25289eb2 | 1524 | if (lp->stopped) |
6c95b8df | 1525 | { |
c9657e70 | 1526 | struct inferior *inf = find_inferior_ptid (lp->ptid); |
25289eb2 PA |
1527 | |
1528 | if (inf->vfork_child != NULL) | |
1529 | { | |
1530 | if (debug_linux_nat) | |
1531 | fprintf_unfiltered (gdb_stdlog, | |
1532 | "RC: Not resuming %s (vfork parent)\n", | |
1533 | target_pid_to_str (lp->ptid)); | |
1534 | } | |
8a99810d | 1535 | else if (!lwp_status_pending_p (lp)) |
25289eb2 PA |
1536 | { |
1537 | if (debug_linux_nat) | |
1538 | fprintf_unfiltered (gdb_stdlog, | |
e5ef252a PA |
1539 | "RC: Resuming sibling %s, %s, %s\n", |
1540 | target_pid_to_str (lp->ptid), | |
1541 | (signo != GDB_SIGNAL_0 | |
1542 | ? strsignal (gdb_signal_to_host (signo)) | |
1543 | : "0"), | |
1544 | step ? "step" : "resume"); | |
25289eb2 | 1545 | |
8a99810d | 1546 | linux_resume_one_lwp (lp, step, signo); |
25289eb2 PA |
1547 | } |
1548 | else | |
1549 | { | |
1550 | if (debug_linux_nat) | |
1551 | fprintf_unfiltered (gdb_stdlog, | |
1552 | "RC: Not resuming sibling %s (has pending)\n", | |
1553 | target_pid_to_str (lp->ptid)); | |
1554 | } | |
6c95b8df | 1555 | } |
25289eb2 | 1556 | else |
d6b0e80f | 1557 | { |
d90e17a7 PA |
1558 | if (debug_linux_nat) |
1559 | fprintf_unfiltered (gdb_stdlog, | |
25289eb2 | 1560 | "RC: Not resuming sibling %s (not stopped)\n", |
d6b0e80f | 1561 | target_pid_to_str (lp->ptid)); |
d6b0e80f | 1562 | } |
25289eb2 | 1563 | } |
d6b0e80f | 1564 | |
8817a6f2 PA |
1565 | /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing. |
1566 | Resume LWP with the last stop signal, if it is in pass state. */ | |
e5ef252a | 1567 | |
25289eb2 | 1568 | static int |
8817a6f2 | 1569 | linux_nat_resume_callback (struct lwp_info *lp, void *except) |
25289eb2 | 1570 | { |
e5ef252a PA |
1571 | enum gdb_signal signo = GDB_SIGNAL_0; |
1572 | ||
8817a6f2 PA |
1573 | if (lp == except) |
1574 | return 0; | |
1575 | ||
e5ef252a PA |
1576 | if (lp->stopped) |
1577 | { | |
1578 | struct thread_info *thread; | |
1579 | ||
1580 | thread = find_thread_ptid (lp->ptid); | |
1581 | if (thread != NULL) | |
1582 | { | |
70509625 | 1583 | signo = thread->suspend.stop_signal; |
e5ef252a PA |
1584 | thread->suspend.stop_signal = GDB_SIGNAL_0; |
1585 | } | |
1586 | } | |
1587 | ||
1588 | resume_lwp (lp, 0, signo); | |
d6b0e80f AC |
1589 | return 0; |
1590 | } | |
1591 | ||
1592 | static int | |
1593 | resume_clear_callback (struct lwp_info *lp, void *data) | |
1594 | { | |
1595 | lp->resumed = 0; | |
25289eb2 | 1596 | lp->last_resume_kind = resume_stop; |
d6b0e80f AC |
1597 | return 0; |
1598 | } | |
1599 | ||
1600 | static int | |
1601 | resume_set_callback (struct lwp_info *lp, void *data) | |
1602 | { | |
1603 | lp->resumed = 1; | |
25289eb2 | 1604 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1605 | return 0; |
1606 | } | |
1607 | ||
1608 | static void | |
28439f5e | 1609 | linux_nat_resume (struct target_ops *ops, |
2ea28649 | 1610 | ptid_t ptid, int step, enum gdb_signal signo) |
d6b0e80f AC |
1611 | { |
1612 | struct lwp_info *lp; | |
d90e17a7 | 1613 | int resume_many; |
d6b0e80f | 1614 | |
76f50ad1 DJ |
1615 | if (debug_linux_nat) |
1616 | fprintf_unfiltered (gdb_stdlog, | |
1617 | "LLR: Preparing to %s %s, %s, inferior_ptid %s\n", | |
1618 | step ? "step" : "resume", | |
1619 | target_pid_to_str (ptid), | |
a493e3e2 | 1620 | (signo != GDB_SIGNAL_0 |
2ea28649 | 1621 | ? strsignal (gdb_signal_to_host (signo)) : "0"), |
76f50ad1 DJ |
1622 | target_pid_to_str (inferior_ptid)); |
1623 | ||
d6b0e80f | 1624 | /* A specific PTID means `step only this process id'. */ |
d90e17a7 PA |
1625 | resume_many = (ptid_equal (minus_one_ptid, ptid) |
1626 | || ptid_is_pid (ptid)); | |
4c28f408 | 1627 | |
e3e9f5a2 PA |
1628 | /* Mark the lwps we're resuming as resumed. */ |
1629 | iterate_over_lwps (ptid, resume_set_callback, NULL); | |
d6b0e80f | 1630 | |
d90e17a7 PA |
1631 | /* See if it's the current inferior that should be handled |
1632 | specially. */ | |
1633 | if (resume_many) | |
1634 | lp = find_lwp_pid (inferior_ptid); | |
1635 | else | |
1636 | lp = find_lwp_pid (ptid); | |
9f0bdab8 | 1637 | gdb_assert (lp != NULL); |
d6b0e80f | 1638 | |
9f0bdab8 | 1639 | /* Remember if we're stepping. */ |
25289eb2 | 1640 | lp->last_resume_kind = step ? resume_step : resume_continue; |
d6b0e80f | 1641 | |
9f0bdab8 DJ |
1642 | /* If we have a pending wait status for this thread, there is no |
1643 | point in resuming the process. But first make sure that | |
1644 | linux_nat_wait won't preemptively handle the event - we | |
1645 | should never take this short-circuit if we are going to | |
1646 | leave LP running, since we have skipped resuming all the | |
1647 | other threads. This bit of code needs to be synchronized | |
1648 | with linux_nat_wait. */ | |
76f50ad1 | 1649 | |
9f0bdab8 DJ |
1650 | if (lp->status && WIFSTOPPED (lp->status)) |
1651 | { | |
2455069d UW |
1652 | if (!lp->step |
1653 | && WSTOPSIG (lp->status) | |
1654 | && sigismember (&pass_mask, WSTOPSIG (lp->status))) | |
d6b0e80f | 1655 | { |
9f0bdab8 DJ |
1656 | if (debug_linux_nat) |
1657 | fprintf_unfiltered (gdb_stdlog, | |
1658 | "LLR: Not short circuiting for ignored " | |
1659 | "status 0x%x\n", lp->status); | |
1660 | ||
d6b0e80f AC |
1661 | /* FIXME: What should we do if we are supposed to continue |
1662 | this thread with a signal? */ | |
a493e3e2 | 1663 | gdb_assert (signo == GDB_SIGNAL_0); |
2ea28649 | 1664 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
9f0bdab8 DJ |
1665 | lp->status = 0; |
1666 | } | |
1667 | } | |
76f50ad1 | 1668 | |
8a99810d | 1669 | if (lwp_status_pending_p (lp)) |
9f0bdab8 DJ |
1670 | { |
1671 | /* FIXME: What should we do if we are supposed to continue | |
1672 | this thread with a signal? */ | |
a493e3e2 | 1673 | gdb_assert (signo == GDB_SIGNAL_0); |
76f50ad1 | 1674 | |
9f0bdab8 DJ |
1675 | if (debug_linux_nat) |
1676 | fprintf_unfiltered (gdb_stdlog, | |
1677 | "LLR: Short circuiting for status 0x%x\n", | |
1678 | lp->status); | |
d6b0e80f | 1679 | |
7feb7d06 PA |
1680 | if (target_can_async_p ()) |
1681 | { | |
1682 | target_async (inferior_event_handler, 0); | |
1683 | /* Tell the event loop we have something to process. */ | |
1684 | async_file_mark (); | |
1685 | } | |
9f0bdab8 | 1686 | return; |
d6b0e80f AC |
1687 | } |
1688 | ||
d90e17a7 | 1689 | if (resume_many) |
8817a6f2 | 1690 | iterate_over_lwps (ptid, linux_nat_resume_callback, lp); |
d90e17a7 | 1691 | |
8a99810d | 1692 | linux_resume_one_lwp (lp, step, signo); |
9f0bdab8 | 1693 | |
d6b0e80f AC |
1694 | if (debug_linux_nat) |
1695 | fprintf_unfiltered (gdb_stdlog, | |
1696 | "LLR: %s %s, %s (resume event thread)\n", | |
1697 | step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
1698 | target_pid_to_str (ptid), | |
a493e3e2 | 1699 | (signo != GDB_SIGNAL_0 |
2ea28649 | 1700 | ? strsignal (gdb_signal_to_host (signo)) : "0")); |
b84876c2 PA |
1701 | |
1702 | if (target_can_async_p ()) | |
8ea051c5 | 1703 | target_async (inferior_event_handler, 0); |
d6b0e80f AC |
1704 | } |
1705 | ||
c5f62d5f | 1706 | /* Send a signal to an LWP. */ |
d6b0e80f AC |
1707 | |
1708 | static int | |
1709 | kill_lwp (int lwpid, int signo) | |
1710 | { | |
c5f62d5f DE |
1711 | /* Use tkill, if possible, in case we are using nptl threads. If tkill |
1712 | fails, then we are not using nptl threads and we should be using kill. */ | |
d6b0e80f AC |
1713 | |
1714 | #ifdef HAVE_TKILL_SYSCALL | |
c5f62d5f DE |
1715 | { |
1716 | static int tkill_failed; | |
1717 | ||
1718 | if (!tkill_failed) | |
1719 | { | |
1720 | int ret; | |
1721 | ||
1722 | errno = 0; | |
1723 | ret = syscall (__NR_tkill, lwpid, signo); | |
1724 | if (errno != ENOSYS) | |
1725 | return ret; | |
1726 | tkill_failed = 1; | |
1727 | } | |
1728 | } | |
d6b0e80f AC |
1729 | #endif |
1730 | ||
1731 | return kill (lwpid, signo); | |
1732 | } | |
1733 | ||
ca2163eb PA |
1734 | /* Handle a GNU/Linux syscall trap wait response. If we see a syscall |
1735 | event, check if the core is interested in it: if not, ignore the | |
1736 | event, and keep waiting; otherwise, we need to toggle the LWP's | |
1737 | syscall entry/exit status, since the ptrace event itself doesn't | |
1738 | indicate it, and report the trap to higher layers. */ | |
1739 | ||
1740 | static int | |
1741 | linux_handle_syscall_trap (struct lwp_info *lp, int stopping) | |
1742 | { | |
1743 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
1744 | struct gdbarch *gdbarch = target_thread_architecture (lp->ptid); | |
1745 | int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid); | |
1746 | ||
1747 | if (stopping) | |
1748 | { | |
1749 | /* If we're stopping threads, there's a SIGSTOP pending, which | |
1750 | makes it so that the LWP reports an immediate syscall return, | |
1751 | followed by the SIGSTOP. Skip seeing that "return" using | |
1752 | PTRACE_CONT directly, and let stop_wait_callback collect the | |
1753 | SIGSTOP. Later when the thread is resumed, a new syscall | |
1754 | entry event. If we didn't do this (and returned 0), we'd | |
1755 | leave a syscall entry pending, and our caller, by using | |
1756 | PTRACE_CONT to collect the SIGSTOP, skips the syscall return | |
1757 | itself. Later, when the user re-resumes this LWP, we'd see | |
1758 | another syscall entry event and we'd mistake it for a return. | |
1759 | ||
1760 | If stop_wait_callback didn't force the SIGSTOP out of the LWP | |
1761 | (leaving immediately with LWP->signalled set, without issuing | |
1762 | a PTRACE_CONT), it would still be problematic to leave this | |
1763 | syscall enter pending, as later when the thread is resumed, | |
1764 | it would then see the same syscall exit mentioned above, | |
1765 | followed by the delayed SIGSTOP, while the syscall didn't | |
1766 | actually get to execute. It seems it would be even more | |
1767 | confusing to the user. */ | |
1768 | ||
1769 | if (debug_linux_nat) | |
1770 | fprintf_unfiltered (gdb_stdlog, | |
1771 | "LHST: ignoring syscall %d " | |
1772 | "for LWP %ld (stopping threads), " | |
1773 | "resuming with PTRACE_CONT for SIGSTOP\n", | |
1774 | syscall_number, | |
dfd4cc63 | 1775 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1776 | |
1777 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
dfd4cc63 | 1778 | ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0); |
8817a6f2 | 1779 | lp->stopped = 0; |
ca2163eb PA |
1780 | return 1; |
1781 | } | |
1782 | ||
1783 | if (catch_syscall_enabled ()) | |
1784 | { | |
1785 | /* Always update the entry/return state, even if this particular | |
1786 | syscall isn't interesting to the core now. In async mode, | |
1787 | the user could install a new catchpoint for this syscall | |
1788 | between syscall enter/return, and we'll need to know to | |
1789 | report a syscall return if that happens. */ | |
1790 | lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1791 | ? TARGET_WAITKIND_SYSCALL_RETURN | |
1792 | : TARGET_WAITKIND_SYSCALL_ENTRY); | |
1793 | ||
1794 | if (catching_syscall_number (syscall_number)) | |
1795 | { | |
1796 | /* Alright, an event to report. */ | |
1797 | ourstatus->kind = lp->syscall_state; | |
1798 | ourstatus->value.syscall_number = syscall_number; | |
1799 | ||
1800 | if (debug_linux_nat) | |
1801 | fprintf_unfiltered (gdb_stdlog, | |
1802 | "LHST: stopping for %s of syscall %d" | |
1803 | " for LWP %ld\n", | |
3e43a32a MS |
1804 | lp->syscall_state |
1805 | == TARGET_WAITKIND_SYSCALL_ENTRY | |
ca2163eb PA |
1806 | ? "entry" : "return", |
1807 | syscall_number, | |
dfd4cc63 | 1808 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1809 | return 0; |
1810 | } | |
1811 | ||
1812 | if (debug_linux_nat) | |
1813 | fprintf_unfiltered (gdb_stdlog, | |
1814 | "LHST: ignoring %s of syscall %d " | |
1815 | "for LWP %ld\n", | |
1816 | lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1817 | ? "entry" : "return", | |
1818 | syscall_number, | |
dfd4cc63 | 1819 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1820 | } |
1821 | else | |
1822 | { | |
1823 | /* If we had been syscall tracing, and hence used PT_SYSCALL | |
1824 | before on this LWP, it could happen that the user removes all | |
1825 | syscall catchpoints before we get to process this event. | |
1826 | There are two noteworthy issues here: | |
1827 | ||
1828 | - When stopped at a syscall entry event, resuming with | |
1829 | PT_STEP still resumes executing the syscall and reports a | |
1830 | syscall return. | |
1831 | ||
1832 | - Only PT_SYSCALL catches syscall enters. If we last | |
1833 | single-stepped this thread, then this event can't be a | |
1834 | syscall enter. If we last single-stepped this thread, this | |
1835 | has to be a syscall exit. | |
1836 | ||
1837 | The points above mean that the next resume, be it PT_STEP or | |
1838 | PT_CONTINUE, can not trigger a syscall trace event. */ | |
1839 | if (debug_linux_nat) | |
1840 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
1841 | "LHST: caught syscall event " |
1842 | "with no syscall catchpoints." | |
ca2163eb PA |
1843 | " %d for LWP %ld, ignoring\n", |
1844 | syscall_number, | |
dfd4cc63 | 1845 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1846 | lp->syscall_state = TARGET_WAITKIND_IGNORE; |
1847 | } | |
1848 | ||
1849 | /* The core isn't interested in this event. For efficiency, avoid | |
1850 | stopping all threads only to have the core resume them all again. | |
1851 | Since we're not stopping threads, if we're still syscall tracing | |
1852 | and not stepping, we can't use PTRACE_CONT here, as we'd miss any | |
1853 | subsequent syscall. Simply resume using the inf-ptrace layer, | |
1854 | which knows when to use PT_SYSCALL or PT_CONTINUE. */ | |
1855 | ||
8a99810d | 1856 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
ca2163eb PA |
1857 | return 1; |
1858 | } | |
1859 | ||
3d799a95 DJ |
1860 | /* Handle a GNU/Linux extended wait response. If we see a clone |
1861 | event, we need to add the new LWP to our list (and not report the | |
1862 | trap to higher layers). This function returns non-zero if the | |
1863 | event should be ignored and we should wait again. If STOPPING is | |
1864 | true, the new LWP remains stopped, otherwise it is continued. */ | |
d6b0e80f AC |
1865 | |
1866 | static int | |
3d799a95 DJ |
1867 | linux_handle_extended_wait (struct lwp_info *lp, int status, |
1868 | int stopping) | |
d6b0e80f | 1869 | { |
dfd4cc63 | 1870 | int pid = ptid_get_lwp (lp->ptid); |
3d799a95 | 1871 | struct target_waitstatus *ourstatus = &lp->waitstatus; |
89a5711c | 1872 | int event = linux_ptrace_get_extended_event (status); |
d6b0e80f | 1873 | |
3d799a95 DJ |
1874 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
1875 | || event == PTRACE_EVENT_CLONE) | |
d6b0e80f | 1876 | { |
3d799a95 DJ |
1877 | unsigned long new_pid; |
1878 | int ret; | |
1879 | ||
1880 | ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); | |
6fc19103 | 1881 | |
3d799a95 DJ |
1882 | /* If we haven't already seen the new PID stop, wait for it now. */ |
1883 | if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
1884 | { | |
1885 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
1886 | hits the SIGSTOP, but we're already attached. */ | |
1887 | ret = my_waitpid (new_pid, &status, | |
1888 | (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0); | |
1889 | if (ret == -1) | |
1890 | perror_with_name (_("waiting for new child")); | |
1891 | else if (ret != new_pid) | |
1892 | internal_error (__FILE__, __LINE__, | |
1893 | _("wait returned unexpected PID %d"), ret); | |
1894 | else if (!WIFSTOPPED (status)) | |
1895 | internal_error (__FILE__, __LINE__, | |
1896 | _("wait returned unexpected status 0x%x"), status); | |
1897 | } | |
1898 | ||
3a3e9ee3 | 1899 | ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0); |
3d799a95 | 1900 | |
26cb8b7c PA |
1901 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) |
1902 | { | |
1903 | /* The arch-specific native code may need to know about new | |
1904 | forks even if those end up never mapped to an | |
1905 | inferior. */ | |
1906 | if (linux_nat_new_fork != NULL) | |
1907 | linux_nat_new_fork (lp, new_pid); | |
1908 | } | |
1909 | ||
2277426b | 1910 | if (event == PTRACE_EVENT_FORK |
dfd4cc63 | 1911 | && linux_fork_checkpointing_p (ptid_get_pid (lp->ptid))) |
2277426b | 1912 | { |
2277426b PA |
1913 | /* Handle checkpointing by linux-fork.c here as a special |
1914 | case. We don't want the follow-fork-mode or 'catch fork' | |
1915 | to interfere with this. */ | |
1916 | ||
1917 | /* This won't actually modify the breakpoint list, but will | |
1918 | physically remove the breakpoints from the child. */ | |
d80ee84f | 1919 | detach_breakpoints (ptid_build (new_pid, new_pid, 0)); |
2277426b PA |
1920 | |
1921 | /* Retain child fork in ptrace (stopped) state. */ | |
14571dad MS |
1922 | if (!find_fork_pid (new_pid)) |
1923 | add_fork (new_pid); | |
2277426b PA |
1924 | |
1925 | /* Report as spurious, so that infrun doesn't want to follow | |
1926 | this fork. We're actually doing an infcall in | |
1927 | linux-fork.c. */ | |
1928 | ourstatus->kind = TARGET_WAITKIND_SPURIOUS; | |
2277426b PA |
1929 | |
1930 | /* Report the stop to the core. */ | |
1931 | return 0; | |
1932 | } | |
1933 | ||
3d799a95 DJ |
1934 | if (event == PTRACE_EVENT_FORK) |
1935 | ourstatus->kind = TARGET_WAITKIND_FORKED; | |
1936 | else if (event == PTRACE_EVENT_VFORK) | |
1937 | ourstatus->kind = TARGET_WAITKIND_VFORKED; | |
6fc19103 | 1938 | else |
3d799a95 | 1939 | { |
78768c4a JK |
1940 | struct lwp_info *new_lp; |
1941 | ||
3d799a95 | 1942 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
78768c4a | 1943 | |
3c4d7e12 PA |
1944 | if (debug_linux_nat) |
1945 | fprintf_unfiltered (gdb_stdlog, | |
1946 | "LHEW: Got clone event " | |
1947 | "from LWP %d, new child is LWP %ld\n", | |
1948 | pid, new_pid); | |
1949 | ||
dfd4cc63 | 1950 | new_lp = add_lwp (ptid_build (ptid_get_pid (lp->ptid), new_pid, 0)); |
3d799a95 | 1951 | new_lp->cloned = 1; |
4c28f408 | 1952 | new_lp->stopped = 1; |
d6b0e80f | 1953 | |
3d799a95 DJ |
1954 | if (WSTOPSIG (status) != SIGSTOP) |
1955 | { | |
1956 | /* This can happen if someone starts sending signals to | |
1957 | the new thread before it gets a chance to run, which | |
1958 | have a lower number than SIGSTOP (e.g. SIGUSR1). | |
1959 | This is an unlikely case, and harder to handle for | |
1960 | fork / vfork than for clone, so we do not try - but | |
1961 | we handle it for clone events here. We'll send | |
1962 | the other signal on to the thread below. */ | |
1963 | ||
1964 | new_lp->signalled = 1; | |
1965 | } | |
1966 | else | |
79395f92 PA |
1967 | { |
1968 | struct thread_info *tp; | |
1969 | ||
1970 | /* When we stop for an event in some other thread, and | |
1971 | pull the thread list just as this thread has cloned, | |
1972 | we'll have seen the new thread in the thread_db list | |
1973 | before handling the CLONE event (glibc's | |
1974 | pthread_create adds the new thread to the thread list | |
1975 | before clone'ing, and has the kernel fill in the | |
1976 | thread's tid on the clone call with | |
1977 | CLONE_PARENT_SETTID). If that happened, and the core | |
1978 | had requested the new thread to stop, we'll have | |
1979 | killed it with SIGSTOP. But since SIGSTOP is not an | |
1980 | RT signal, it can only be queued once. We need to be | |
1981 | careful to not resume the LWP if we wanted it to | |
1982 | stop. In that case, we'll leave the SIGSTOP pending. | |
a493e3e2 | 1983 | It will later be reported as GDB_SIGNAL_0. */ |
79395f92 PA |
1984 | tp = find_thread_ptid (new_lp->ptid); |
1985 | if (tp != NULL && tp->stop_requested) | |
1986 | new_lp->last_resume_kind = resume_stop; | |
1987 | else | |
1988 | status = 0; | |
1989 | } | |
d6b0e80f | 1990 | |
4c28f408 | 1991 | if (non_stop) |
3d799a95 | 1992 | { |
4c28f408 PA |
1993 | /* Add the new thread to GDB's lists as soon as possible |
1994 | so that: | |
1995 | ||
1996 | 1) the frontend doesn't have to wait for a stop to | |
1997 | display them, and, | |
1998 | ||
1999 | 2) we tag it with the correct running state. */ | |
2000 | ||
2001 | /* If the thread_db layer is active, let it know about | |
2002 | this new thread, and add it to GDB's list. */ | |
2003 | if (!thread_db_attach_lwp (new_lp->ptid)) | |
2004 | { | |
2005 | /* We're not using thread_db. Add it to GDB's | |
2006 | list. */ | |
dfd4cc63 | 2007 | target_post_attach (ptid_get_lwp (new_lp->ptid)); |
4c28f408 PA |
2008 | add_thread (new_lp->ptid); |
2009 | } | |
2010 | ||
2011 | if (!stopping) | |
2012 | { | |
2013 | set_running (new_lp->ptid, 1); | |
2014 | set_executing (new_lp->ptid, 1); | |
e21ffe51 PA |
2015 | /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced |
2016 | resume_stop. */ | |
2017 | new_lp->last_resume_kind = resume_continue; | |
4c28f408 PA |
2018 | } |
2019 | } | |
2020 | ||
79395f92 PA |
2021 | if (status != 0) |
2022 | { | |
2023 | /* We created NEW_LP so it cannot yet contain STATUS. */ | |
2024 | gdb_assert (new_lp->status == 0); | |
2025 | ||
2026 | /* Save the wait status to report later. */ | |
2027 | if (debug_linux_nat) | |
2028 | fprintf_unfiltered (gdb_stdlog, | |
2029 | "LHEW: waitpid of new LWP %ld, " | |
2030 | "saving status %s\n", | |
dfd4cc63 | 2031 | (long) ptid_get_lwp (new_lp->ptid), |
79395f92 PA |
2032 | status_to_str (status)); |
2033 | new_lp->status = status; | |
2034 | } | |
2035 | ||
ca2163eb PA |
2036 | /* Note the need to use the low target ops to resume, to |
2037 | handle resuming with PT_SYSCALL if we have syscall | |
2038 | catchpoints. */ | |
4c28f408 PA |
2039 | if (!stopping) |
2040 | { | |
3d799a95 | 2041 | new_lp->resumed = 1; |
ca2163eb | 2042 | |
79395f92 | 2043 | if (status == 0) |
ad34eb2f | 2044 | { |
e21ffe51 | 2045 | gdb_assert (new_lp->last_resume_kind == resume_continue); |
ad34eb2f JK |
2046 | if (debug_linux_nat) |
2047 | fprintf_unfiltered (gdb_stdlog, | |
79395f92 | 2048 | "LHEW: resuming new LWP %ld\n", |
dfd4cc63 | 2049 | ptid_get_lwp (new_lp->ptid)); |
8a99810d | 2050 | linux_resume_one_lwp (new_lp, 0, GDB_SIGNAL_0); |
ad34eb2f JK |
2051 | } |
2052 | } | |
d6b0e80f | 2053 | |
3d799a95 DJ |
2054 | if (debug_linux_nat) |
2055 | fprintf_unfiltered (gdb_stdlog, | |
3c4d7e12 | 2056 | "LHEW: resuming parent LWP %d\n", pid); |
8a99810d | 2057 | linux_resume_one_lwp (lp, 0, GDB_SIGNAL_0); |
3d799a95 DJ |
2058 | return 1; |
2059 | } | |
2060 | ||
2061 | return 0; | |
d6b0e80f AC |
2062 | } |
2063 | ||
3d799a95 DJ |
2064 | if (event == PTRACE_EVENT_EXEC) |
2065 | { | |
a75724bc PA |
2066 | if (debug_linux_nat) |
2067 | fprintf_unfiltered (gdb_stdlog, | |
2068 | "LHEW: Got exec event from LWP %ld\n", | |
dfd4cc63 | 2069 | ptid_get_lwp (lp->ptid)); |
a75724bc | 2070 | |
3d799a95 DJ |
2071 | ourstatus->kind = TARGET_WAITKIND_EXECD; |
2072 | ourstatus->value.execd_pathname | |
8dd27370 | 2073 | = xstrdup (linux_child_pid_to_exec_file (NULL, pid)); |
3d799a95 | 2074 | |
8af756ef PA |
2075 | /* The thread that execed must have been resumed, but, when a |
2076 | thread execs, it changes its tid to the tgid, and the old | |
2077 | tgid thread might have not been resumed. */ | |
2078 | lp->resumed = 1; | |
6c95b8df PA |
2079 | return 0; |
2080 | } | |
2081 | ||
2082 | if (event == PTRACE_EVENT_VFORK_DONE) | |
2083 | { | |
2084 | if (current_inferior ()->waiting_for_vfork_done) | |
3d799a95 | 2085 | { |
6c95b8df | 2086 | if (debug_linux_nat) |
3e43a32a MS |
2087 | fprintf_unfiltered (gdb_stdlog, |
2088 | "LHEW: Got expected PTRACE_EVENT_" | |
2089 | "VFORK_DONE from LWP %ld: stopping\n", | |
dfd4cc63 | 2090 | ptid_get_lwp (lp->ptid)); |
3d799a95 | 2091 | |
6c95b8df PA |
2092 | ourstatus->kind = TARGET_WAITKIND_VFORK_DONE; |
2093 | return 0; | |
3d799a95 DJ |
2094 | } |
2095 | ||
6c95b8df | 2096 | if (debug_linux_nat) |
3e43a32a MS |
2097 | fprintf_unfiltered (gdb_stdlog, |
2098 | "LHEW: Got PTRACE_EVENT_VFORK_DONE " | |
2099 | "from LWP %ld: resuming\n", | |
dfd4cc63 LM |
2100 | ptid_get_lwp (lp->ptid)); |
2101 | ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0); | |
6c95b8df | 2102 | return 1; |
3d799a95 DJ |
2103 | } |
2104 | ||
2105 | internal_error (__FILE__, __LINE__, | |
2106 | _("unknown ptrace event %d"), event); | |
d6b0e80f AC |
2107 | } |
2108 | ||
2109 | /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has | |
2110 | exited. */ | |
2111 | ||
2112 | static int | |
2113 | wait_lwp (struct lwp_info *lp) | |
2114 | { | |
2115 | pid_t pid; | |
432b4d03 | 2116 | int status = 0; |
d6b0e80f | 2117 | int thread_dead = 0; |
432b4d03 | 2118 | sigset_t prev_mask; |
d6b0e80f AC |
2119 | |
2120 | gdb_assert (!lp->stopped); | |
2121 | gdb_assert (lp->status == 0); | |
2122 | ||
432b4d03 JK |
2123 | /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
2124 | block_child_signals (&prev_mask); | |
2125 | ||
2126 | for (;;) | |
d6b0e80f | 2127 | { |
432b4d03 JK |
2128 | /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind |
2129 | was right and we should just call sigsuspend. */ | |
2130 | ||
dfd4cc63 | 2131 | pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, WNOHANG); |
d6b0e80f | 2132 | if (pid == -1 && errno == ECHILD) |
dfd4cc63 | 2133 | pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, __WCLONE | WNOHANG); |
a9f4bb21 PA |
2134 | if (pid == -1 && errno == ECHILD) |
2135 | { | |
2136 | /* The thread has previously exited. We need to delete it | |
2137 | now because, for some vendor 2.4 kernels with NPTL | |
2138 | support backported, there won't be an exit event unless | |
2139 | it is the main thread. 2.6 kernels will report an exit | |
2140 | event for each thread that exits, as expected. */ | |
2141 | thread_dead = 1; | |
2142 | if (debug_linux_nat) | |
2143 | fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n", | |
2144 | target_pid_to_str (lp->ptid)); | |
2145 | } | |
432b4d03 JK |
2146 | if (pid != 0) |
2147 | break; | |
2148 | ||
2149 | /* Bugs 10970, 12702. | |
2150 | Thread group leader may have exited in which case we'll lock up in | |
2151 | waitpid if there are other threads, even if they are all zombies too. | |
2152 | Basically, we're not supposed to use waitpid this way. | |
2153 | __WCLONE is not applicable for the leader so we can't use that. | |
2154 | LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED | |
2155 | process; it gets ESRCH both for the zombie and for running processes. | |
2156 | ||
2157 | As a workaround, check if we're waiting for the thread group leader and | |
2158 | if it's a zombie, and avoid calling waitpid if it is. | |
2159 | ||
2160 | This is racy, what if the tgl becomes a zombie right after we check? | |
2161 | Therefore always use WNOHANG with sigsuspend - it is equivalent to | |
5f572dec | 2162 | waiting waitpid but linux_proc_pid_is_zombie is safe this way. */ |
432b4d03 | 2163 | |
dfd4cc63 LM |
2164 | if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid) |
2165 | && linux_proc_pid_is_zombie (ptid_get_lwp (lp->ptid))) | |
d6b0e80f | 2166 | { |
d6b0e80f AC |
2167 | thread_dead = 1; |
2168 | if (debug_linux_nat) | |
432b4d03 JK |
2169 | fprintf_unfiltered (gdb_stdlog, |
2170 | "WL: Thread group leader %s vanished.\n", | |
d6b0e80f | 2171 | target_pid_to_str (lp->ptid)); |
432b4d03 | 2172 | break; |
d6b0e80f | 2173 | } |
432b4d03 JK |
2174 | |
2175 | /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers | |
2176 | get invoked despite our caller had them intentionally blocked by | |
2177 | block_child_signals. This is sensitive only to the loop of | |
2178 | linux_nat_wait_1 and there if we get called my_waitpid gets called | |
2179 | again before it gets to sigsuspend so we can safely let the handlers | |
2180 | get executed here. */ | |
2181 | ||
d36bf488 DE |
2182 | if (debug_linux_nat) |
2183 | fprintf_unfiltered (gdb_stdlog, "WL: about to sigsuspend\n"); | |
432b4d03 JK |
2184 | sigsuspend (&suspend_mask); |
2185 | } | |
2186 | ||
2187 | restore_child_signals_mask (&prev_mask); | |
2188 | ||
d6b0e80f AC |
2189 | if (!thread_dead) |
2190 | { | |
dfd4cc63 | 2191 | gdb_assert (pid == ptid_get_lwp (lp->ptid)); |
d6b0e80f AC |
2192 | |
2193 | if (debug_linux_nat) | |
2194 | { | |
2195 | fprintf_unfiltered (gdb_stdlog, | |
2196 | "WL: waitpid %s received %s\n", | |
2197 | target_pid_to_str (lp->ptid), | |
2198 | status_to_str (status)); | |
2199 | } | |
d6b0e80f | 2200 | |
a9f4bb21 PA |
2201 | /* Check if the thread has exited. */ |
2202 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
2203 | { | |
2204 | thread_dead = 1; | |
2205 | if (debug_linux_nat) | |
2206 | fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n", | |
2207 | target_pid_to_str (lp->ptid)); | |
2208 | } | |
d6b0e80f AC |
2209 | } |
2210 | ||
2211 | if (thread_dead) | |
2212 | { | |
e26af52f | 2213 | exit_lwp (lp); |
d6b0e80f AC |
2214 | return 0; |
2215 | } | |
2216 | ||
2217 | gdb_assert (WIFSTOPPED (status)); | |
8817a6f2 | 2218 | lp->stopped = 1; |
d6b0e80f | 2219 | |
8784d563 PA |
2220 | if (lp->must_set_ptrace_flags) |
2221 | { | |
2222 | struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid)); | |
2223 | ||
2224 | linux_enable_event_reporting (ptid_get_lwp (lp->ptid), inf->attach_flag); | |
2225 | lp->must_set_ptrace_flags = 0; | |
2226 | } | |
2227 | ||
ca2163eb PA |
2228 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2229 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2230 | { | |
2231 | /* No longer need the sysgood bit. The ptrace event ends up | |
2232 | recorded in lp->waitstatus if we care for it. We can carry | |
2233 | on handling the event like a regular SIGTRAP from here | |
2234 | on. */ | |
2235 | status = W_STOPCODE (SIGTRAP); | |
2236 | if (linux_handle_syscall_trap (lp, 1)) | |
2237 | return wait_lwp (lp); | |
2238 | } | |
2239 | ||
d6b0e80f | 2240 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2241 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2242 | && linux_is_extended_waitstatus (status)) | |
d6b0e80f AC |
2243 | { |
2244 | if (debug_linux_nat) | |
2245 | fprintf_unfiltered (gdb_stdlog, | |
2246 | "WL: Handling extended status 0x%06x\n", | |
2247 | status); | |
3d799a95 | 2248 | if (linux_handle_extended_wait (lp, status, 1)) |
d6b0e80f AC |
2249 | return wait_lwp (lp); |
2250 | } | |
2251 | ||
2252 | return status; | |
2253 | } | |
2254 | ||
2255 | /* Send a SIGSTOP to LP. */ | |
2256 | ||
2257 | static int | |
2258 | stop_callback (struct lwp_info *lp, void *data) | |
2259 | { | |
2260 | if (!lp->stopped && !lp->signalled) | |
2261 | { | |
2262 | int ret; | |
2263 | ||
2264 | if (debug_linux_nat) | |
2265 | { | |
2266 | fprintf_unfiltered (gdb_stdlog, | |
2267 | "SC: kill %s **<SIGSTOP>**\n", | |
2268 | target_pid_to_str (lp->ptid)); | |
2269 | } | |
2270 | errno = 0; | |
dfd4cc63 | 2271 | ret = kill_lwp (ptid_get_lwp (lp->ptid), SIGSTOP); |
d6b0e80f AC |
2272 | if (debug_linux_nat) |
2273 | { | |
2274 | fprintf_unfiltered (gdb_stdlog, | |
2275 | "SC: lwp kill %d %s\n", | |
2276 | ret, | |
2277 | errno ? safe_strerror (errno) : "ERRNO-OK"); | |
2278 | } | |
2279 | ||
2280 | lp->signalled = 1; | |
2281 | gdb_assert (lp->status == 0); | |
2282 | } | |
2283 | ||
2284 | return 0; | |
2285 | } | |
2286 | ||
7b50312a PA |
2287 | /* Request a stop on LWP. */ |
2288 | ||
2289 | void | |
2290 | linux_stop_lwp (struct lwp_info *lwp) | |
2291 | { | |
2292 | stop_callback (lwp, NULL); | |
2293 | } | |
2294 | ||
57380f4e | 2295 | /* Return non-zero if LWP PID has a pending SIGINT. */ |
d6b0e80f AC |
2296 | |
2297 | static int | |
57380f4e DJ |
2298 | linux_nat_has_pending_sigint (int pid) |
2299 | { | |
2300 | sigset_t pending, blocked, ignored; | |
57380f4e DJ |
2301 | |
2302 | linux_proc_pending_signals (pid, &pending, &blocked, &ignored); | |
2303 | ||
2304 | if (sigismember (&pending, SIGINT) | |
2305 | && !sigismember (&ignored, SIGINT)) | |
2306 | return 1; | |
2307 | ||
2308 | return 0; | |
2309 | } | |
2310 | ||
2311 | /* Set a flag in LP indicating that we should ignore its next SIGINT. */ | |
2312 | ||
2313 | static int | |
2314 | set_ignore_sigint (struct lwp_info *lp, void *data) | |
d6b0e80f | 2315 | { |
57380f4e DJ |
2316 | /* If a thread has a pending SIGINT, consume it; otherwise, set a |
2317 | flag to consume the next one. */ | |
2318 | if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) | |
2319 | && WSTOPSIG (lp->status) == SIGINT) | |
2320 | lp->status = 0; | |
2321 | else | |
2322 | lp->ignore_sigint = 1; | |
2323 | ||
2324 | return 0; | |
2325 | } | |
2326 | ||
2327 | /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. | |
2328 | This function is called after we know the LWP has stopped; if the LWP | |
2329 | stopped before the expected SIGINT was delivered, then it will never have | |
2330 | arrived. Also, if the signal was delivered to a shared queue and consumed | |
2331 | by a different thread, it will never be delivered to this LWP. */ | |
d6b0e80f | 2332 | |
57380f4e DJ |
2333 | static void |
2334 | maybe_clear_ignore_sigint (struct lwp_info *lp) | |
2335 | { | |
2336 | if (!lp->ignore_sigint) | |
2337 | return; | |
2338 | ||
dfd4cc63 | 2339 | if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp->ptid))) |
57380f4e DJ |
2340 | { |
2341 | if (debug_linux_nat) | |
2342 | fprintf_unfiltered (gdb_stdlog, | |
2343 | "MCIS: Clearing bogus flag for %s\n", | |
2344 | target_pid_to_str (lp->ptid)); | |
2345 | lp->ignore_sigint = 0; | |
2346 | } | |
2347 | } | |
2348 | ||
ebec9a0f PA |
2349 | /* Fetch the possible triggered data watchpoint info and store it in |
2350 | LP. | |
2351 | ||
2352 | On some archs, like x86, that use debug registers to set | |
2353 | watchpoints, it's possible that the way to know which watched | |
2354 | address trapped, is to check the register that is used to select | |
2355 | which address to watch. Problem is, between setting the watchpoint | |
2356 | and reading back which data address trapped, the user may change | |
2357 | the set of watchpoints, and, as a consequence, GDB changes the | |
2358 | debug registers in the inferior. To avoid reading back a stale | |
2359 | stopped-data-address when that happens, we cache in LP the fact | |
2360 | that a watchpoint trapped, and the corresponding data address, as | |
2361 | soon as we see LP stop with a SIGTRAP. If GDB changes the debug | |
2362 | registers meanwhile, we have the cached data we can rely on. */ | |
2363 | ||
9c02b525 PA |
2364 | static int |
2365 | check_stopped_by_watchpoint (struct lwp_info *lp) | |
ebec9a0f PA |
2366 | { |
2367 | struct cleanup *old_chain; | |
2368 | ||
2369 | if (linux_ops->to_stopped_by_watchpoint == NULL) | |
9c02b525 | 2370 | return 0; |
ebec9a0f PA |
2371 | |
2372 | old_chain = save_inferior_ptid (); | |
2373 | inferior_ptid = lp->ptid; | |
2374 | ||
9c02b525 | 2375 | if (linux_ops->to_stopped_by_watchpoint (linux_ops)) |
ebec9a0f | 2376 | { |
9c02b525 PA |
2377 | lp->stop_reason = LWP_STOPPED_BY_WATCHPOINT; |
2378 | ||
ebec9a0f PA |
2379 | if (linux_ops->to_stopped_data_address != NULL) |
2380 | lp->stopped_data_address_p = | |
2381 | linux_ops->to_stopped_data_address (¤t_target, | |
2382 | &lp->stopped_data_address); | |
2383 | else | |
2384 | lp->stopped_data_address_p = 0; | |
2385 | } | |
2386 | ||
2387 | do_cleanups (old_chain); | |
9c02b525 PA |
2388 | |
2389 | return lp->stop_reason == LWP_STOPPED_BY_WATCHPOINT; | |
2390 | } | |
2391 | ||
2392 | /* Called when the LWP stopped for a trap that could be explained by a | |
2393 | watchpoint or a breakpoint. */ | |
2394 | ||
2395 | static void | |
2396 | save_sigtrap (struct lwp_info *lp) | |
2397 | { | |
2398 | gdb_assert (lp->stop_reason == LWP_STOPPED_BY_NO_REASON); | |
2399 | gdb_assert (lp->status != 0); | |
2400 | ||
2401 | if (check_stopped_by_watchpoint (lp)) | |
2402 | return; | |
2403 | ||
2404 | if (linux_nat_status_is_event (lp->status)) | |
2405 | check_stopped_by_breakpoint (lp); | |
ebec9a0f PA |
2406 | } |
2407 | ||
9c02b525 | 2408 | /* Returns true if the LWP had stopped for a watchpoint. */ |
ebec9a0f PA |
2409 | |
2410 | static int | |
6a109b6b | 2411 | linux_nat_stopped_by_watchpoint (struct target_ops *ops) |
ebec9a0f PA |
2412 | { |
2413 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2414 | ||
2415 | gdb_assert (lp != NULL); | |
2416 | ||
9c02b525 | 2417 | return lp->stop_reason == LWP_STOPPED_BY_WATCHPOINT; |
ebec9a0f PA |
2418 | } |
2419 | ||
2420 | static int | |
2421 | linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p) | |
2422 | { | |
2423 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2424 | ||
2425 | gdb_assert (lp != NULL); | |
2426 | ||
2427 | *addr_p = lp->stopped_data_address; | |
2428 | ||
2429 | return lp->stopped_data_address_p; | |
2430 | } | |
2431 | ||
26ab7092 JK |
2432 | /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
2433 | ||
2434 | static int | |
2435 | sigtrap_is_event (int status) | |
2436 | { | |
2437 | return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; | |
2438 | } | |
2439 | ||
26ab7092 JK |
2440 | /* Set alternative SIGTRAP-like events recognizer. If |
2441 | breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be | |
2442 | applied. */ | |
2443 | ||
2444 | void | |
2445 | linux_nat_set_status_is_event (struct target_ops *t, | |
2446 | int (*status_is_event) (int status)) | |
2447 | { | |
2448 | linux_nat_status_is_event = status_is_event; | |
2449 | } | |
2450 | ||
57380f4e DJ |
2451 | /* Wait until LP is stopped. */ |
2452 | ||
2453 | static int | |
2454 | stop_wait_callback (struct lwp_info *lp, void *data) | |
2455 | { | |
c9657e70 | 2456 | struct inferior *inf = find_inferior_ptid (lp->ptid); |
6c95b8df PA |
2457 | |
2458 | /* If this is a vfork parent, bail out, it is not going to report | |
2459 | any SIGSTOP until the vfork is done with. */ | |
2460 | if (inf->vfork_child != NULL) | |
2461 | return 0; | |
2462 | ||
d6b0e80f AC |
2463 | if (!lp->stopped) |
2464 | { | |
2465 | int status; | |
2466 | ||
2467 | status = wait_lwp (lp); | |
2468 | if (status == 0) | |
2469 | return 0; | |
2470 | ||
57380f4e DJ |
2471 | if (lp->ignore_sigint && WIFSTOPPED (status) |
2472 | && WSTOPSIG (status) == SIGINT) | |
d6b0e80f | 2473 | { |
57380f4e | 2474 | lp->ignore_sigint = 0; |
d6b0e80f AC |
2475 | |
2476 | errno = 0; | |
dfd4cc63 | 2477 | ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0); |
8817a6f2 | 2478 | lp->stopped = 0; |
d6b0e80f AC |
2479 | if (debug_linux_nat) |
2480 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
2481 | "PTRACE_CONT %s, 0, 0 (%s) " |
2482 | "(discarding SIGINT)\n", | |
d6b0e80f AC |
2483 | target_pid_to_str (lp->ptid), |
2484 | errno ? safe_strerror (errno) : "OK"); | |
2485 | ||
57380f4e | 2486 | return stop_wait_callback (lp, NULL); |
d6b0e80f AC |
2487 | } |
2488 | ||
57380f4e DJ |
2489 | maybe_clear_ignore_sigint (lp); |
2490 | ||
d6b0e80f AC |
2491 | if (WSTOPSIG (status) != SIGSTOP) |
2492 | { | |
e5ef252a | 2493 | /* The thread was stopped with a signal other than SIGSTOP. */ |
7feb7d06 | 2494 | |
e5ef252a PA |
2495 | if (debug_linux_nat) |
2496 | fprintf_unfiltered (gdb_stdlog, | |
2497 | "SWC: Pending event %s in %s\n", | |
2498 | status_to_str ((int) status), | |
2499 | target_pid_to_str (lp->ptid)); | |
2500 | ||
2501 | /* Save the sigtrap event. */ | |
2502 | lp->status = status; | |
e5ef252a | 2503 | gdb_assert (lp->signalled); |
9c02b525 | 2504 | save_sigtrap (lp); |
d6b0e80f AC |
2505 | } |
2506 | else | |
2507 | { | |
2508 | /* We caught the SIGSTOP that we intended to catch, so | |
2509 | there's no SIGSTOP pending. */ | |
e5ef252a PA |
2510 | |
2511 | if (debug_linux_nat) | |
2512 | fprintf_unfiltered (gdb_stdlog, | |
2513 | "SWC: Delayed SIGSTOP caught for %s.\n", | |
2514 | target_pid_to_str (lp->ptid)); | |
2515 | ||
e5ef252a PA |
2516 | /* Reset SIGNALLED only after the stop_wait_callback call |
2517 | above as it does gdb_assert on SIGNALLED. */ | |
d6b0e80f AC |
2518 | lp->signalled = 0; |
2519 | } | |
2520 | } | |
2521 | ||
2522 | return 0; | |
2523 | } | |
2524 | ||
9c02b525 PA |
2525 | /* Return non-zero if LP has a wait status pending. Discard the |
2526 | pending event and resume the LWP if the event that originally | |
2527 | caused the stop became uninteresting. */ | |
d6b0e80f AC |
2528 | |
2529 | static int | |
2530 | status_callback (struct lwp_info *lp, void *data) | |
2531 | { | |
2532 | /* Only report a pending wait status if we pretend that this has | |
2533 | indeed been resumed. */ | |
ca2163eb PA |
2534 | if (!lp->resumed) |
2535 | return 0; | |
2536 | ||
9c02b525 PA |
2537 | if (lp->stop_reason == LWP_STOPPED_BY_SW_BREAKPOINT |
2538 | || lp->stop_reason == LWP_STOPPED_BY_HW_BREAKPOINT) | |
2539 | { | |
2540 | struct regcache *regcache = get_thread_regcache (lp->ptid); | |
2541 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
2542 | CORE_ADDR pc; | |
2543 | int discard = 0; | |
2544 | ||
2545 | gdb_assert (lp->status != 0); | |
2546 | ||
2547 | pc = regcache_read_pc (regcache); | |
2548 | ||
2549 | if (pc != lp->stop_pc) | |
2550 | { | |
2551 | if (debug_linux_nat) | |
2552 | fprintf_unfiltered (gdb_stdlog, | |
2553 | "SC: PC of %s changed. was=%s, now=%s\n", | |
2554 | target_pid_to_str (lp->ptid), | |
2555 | paddress (target_gdbarch (), lp->stop_pc), | |
2556 | paddress (target_gdbarch (), pc)); | |
2557 | discard = 1; | |
2558 | } | |
2559 | else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) | |
2560 | { | |
2561 | if (debug_linux_nat) | |
2562 | fprintf_unfiltered (gdb_stdlog, | |
2563 | "SC: previous breakpoint of %s, at %s gone\n", | |
2564 | target_pid_to_str (lp->ptid), | |
2565 | paddress (target_gdbarch (), lp->stop_pc)); | |
2566 | ||
2567 | discard = 1; | |
2568 | } | |
2569 | ||
2570 | if (discard) | |
2571 | { | |
2572 | if (debug_linux_nat) | |
2573 | fprintf_unfiltered (gdb_stdlog, | |
2574 | "SC: pending event of %s cancelled.\n", | |
2575 | target_pid_to_str (lp->ptid)); | |
2576 | ||
2577 | lp->status = 0; | |
2578 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); | |
2579 | return 0; | |
2580 | } | |
2581 | return 1; | |
2582 | } | |
2583 | ||
8a99810d | 2584 | return lwp_status_pending_p (lp); |
d6b0e80f AC |
2585 | } |
2586 | ||
2587 | /* Return non-zero if LP isn't stopped. */ | |
2588 | ||
2589 | static int | |
2590 | running_callback (struct lwp_info *lp, void *data) | |
2591 | { | |
25289eb2 | 2592 | return (!lp->stopped |
8a99810d | 2593 | || (lwp_status_pending_p (lp) && lp->resumed)); |
d6b0e80f AC |
2594 | } |
2595 | ||
2596 | /* Count the LWP's that have had events. */ | |
2597 | ||
2598 | static int | |
2599 | count_events_callback (struct lwp_info *lp, void *data) | |
2600 | { | |
2601 | int *count = data; | |
2602 | ||
2603 | gdb_assert (count != NULL); | |
2604 | ||
9c02b525 PA |
2605 | /* Select only resumed LWPs that have an event pending. */ |
2606 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2607 | (*count)++; |
2608 | ||
2609 | return 0; | |
2610 | } | |
2611 | ||
2612 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
2613 | ||
2614 | static int | |
2615 | select_singlestep_lwp_callback (struct lwp_info *lp, void *data) | |
2616 | { | |
25289eb2 PA |
2617 | if (lp->last_resume_kind == resume_step |
2618 | && lp->status != 0) | |
d6b0e80f AC |
2619 | return 1; |
2620 | else | |
2621 | return 0; | |
2622 | } | |
2623 | ||
8a99810d PA |
2624 | /* Returns true if LP has a status pending. */ |
2625 | ||
2626 | static int | |
2627 | lwp_status_pending_p (struct lwp_info *lp) | |
2628 | { | |
2629 | /* We check for lp->waitstatus in addition to lp->status, because we | |
2630 | can have pending process exits recorded in lp->status and | |
2631 | W_EXITCODE(0,0) happens to be 0. */ | |
2632 | return lp->status != 0 || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE; | |
2633 | } | |
2634 | ||
d6b0e80f AC |
2635 | /* Select the Nth LWP that has had a SIGTRAP event. */ |
2636 | ||
2637 | static int | |
2638 | select_event_lwp_callback (struct lwp_info *lp, void *data) | |
2639 | { | |
2640 | int *selector = data; | |
2641 | ||
2642 | gdb_assert (selector != NULL); | |
2643 | ||
9c02b525 PA |
2644 | /* Select only resumed LWPs that have an event pending. */ |
2645 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2646 | if ((*selector)-- == 0) |
2647 | return 1; | |
2648 | ||
2649 | return 0; | |
2650 | } | |
2651 | ||
9c02b525 PA |
2652 | /* Called when the LWP got a signal/trap that could be explained by a |
2653 | software or hardware breakpoint. */ | |
2654 | ||
710151dd | 2655 | static int |
9c02b525 | 2656 | check_stopped_by_breakpoint (struct lwp_info *lp) |
710151dd PA |
2657 | { |
2658 | /* Arrange for a breakpoint to be hit again later. We don't keep | |
2659 | the SIGTRAP status and don't forward the SIGTRAP signal to the | |
2660 | LWP. We will handle the current event, eventually we will resume | |
2661 | this LWP, and this breakpoint will trap again. | |
2662 | ||
2663 | If we do not do this, then we run the risk that the user will | |
2664 | delete or disable the breakpoint, but the LWP will have already | |
2665 | tripped on it. */ | |
2666 | ||
515630c5 UW |
2667 | struct regcache *regcache = get_thread_regcache (lp->ptid); |
2668 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
2669 | CORE_ADDR pc; | |
9c02b525 PA |
2670 | CORE_ADDR sw_bp_pc; |
2671 | ||
2672 | pc = regcache_read_pc (regcache); | |
2673 | sw_bp_pc = pc - target_decr_pc_after_break (gdbarch); | |
515630c5 | 2674 | |
9c02b525 PA |
2675 | if ((!lp->step || lp->stop_pc == sw_bp_pc) |
2676 | && software_breakpoint_inserted_here_p (get_regcache_aspace (regcache), | |
2677 | sw_bp_pc)) | |
710151dd | 2678 | { |
9c02b525 PA |
2679 | /* The LWP was either continued, or stepped a software |
2680 | breakpoint instruction. */ | |
710151dd PA |
2681 | if (debug_linux_nat) |
2682 | fprintf_unfiltered (gdb_stdlog, | |
9c02b525 | 2683 | "CB: Push back software breakpoint for %s\n", |
710151dd PA |
2684 | target_pid_to_str (lp->ptid)); |
2685 | ||
2686 | /* Back up the PC if necessary. */ | |
9c02b525 PA |
2687 | if (pc != sw_bp_pc) |
2688 | regcache_write_pc (regcache, sw_bp_pc); | |
515630c5 | 2689 | |
9c02b525 PA |
2690 | lp->stop_pc = sw_bp_pc; |
2691 | lp->stop_reason = LWP_STOPPED_BY_SW_BREAKPOINT; | |
710151dd PA |
2692 | return 1; |
2693 | } | |
710151dd | 2694 | |
9c02b525 PA |
2695 | if (hardware_breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
2696 | { | |
2697 | if (debug_linux_nat) | |
2698 | fprintf_unfiltered (gdb_stdlog, | |
2699 | "CB: Push back hardware breakpoint for %s\n", | |
2700 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 2701 | |
9c02b525 PA |
2702 | lp->stop_pc = pc; |
2703 | lp->stop_reason = LWP_STOPPED_BY_HW_BREAKPOINT; | |
2704 | return 1; | |
2705 | } | |
d6b0e80f AC |
2706 | |
2707 | return 0; | |
2708 | } | |
2709 | ||
2710 | /* Select one LWP out of those that have events pending. */ | |
2711 | ||
2712 | static void | |
d90e17a7 | 2713 | select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
d6b0e80f AC |
2714 | { |
2715 | int num_events = 0; | |
2716 | int random_selector; | |
9c02b525 | 2717 | struct lwp_info *event_lp = NULL; |
d6b0e80f | 2718 | |
ac264b3b | 2719 | /* Record the wait status for the original LWP. */ |
d6b0e80f AC |
2720 | (*orig_lp)->status = *status; |
2721 | ||
9c02b525 PA |
2722 | /* In all-stop, give preference to the LWP that is being |
2723 | single-stepped. There will be at most one, and it will be the | |
2724 | LWP that the core is most interested in. If we didn't do this, | |
2725 | then we'd have to handle pending step SIGTRAPs somehow in case | |
2726 | the core later continues the previously-stepped thread, as | |
2727 | otherwise we'd report the pending SIGTRAP then, and the core, not | |
2728 | having stepped the thread, wouldn't understand what the trap was | |
2729 | for, and therefore would report it to the user as a random | |
2730 | signal. */ | |
2731 | if (!non_stop) | |
d6b0e80f | 2732 | { |
9c02b525 PA |
2733 | event_lp = iterate_over_lwps (filter, |
2734 | select_singlestep_lwp_callback, NULL); | |
2735 | if (event_lp != NULL) | |
2736 | { | |
2737 | if (debug_linux_nat) | |
2738 | fprintf_unfiltered (gdb_stdlog, | |
2739 | "SEL: Select single-step %s\n", | |
2740 | target_pid_to_str (event_lp->ptid)); | |
2741 | } | |
d6b0e80f | 2742 | } |
9c02b525 PA |
2743 | |
2744 | if (event_lp == NULL) | |
d6b0e80f | 2745 | { |
9c02b525 | 2746 | /* Pick one at random, out of those which have had events. */ |
d6b0e80f | 2747 | |
9c02b525 | 2748 | /* First see how many events we have. */ |
d90e17a7 | 2749 | iterate_over_lwps (filter, count_events_callback, &num_events); |
d6b0e80f | 2750 | |
9c02b525 PA |
2751 | /* Now randomly pick a LWP out of those that have had |
2752 | events. */ | |
d6b0e80f AC |
2753 | random_selector = (int) |
2754 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
2755 | ||
2756 | if (debug_linux_nat && num_events > 1) | |
2757 | fprintf_unfiltered (gdb_stdlog, | |
9c02b525 | 2758 | "SEL: Found %d events, selecting #%d\n", |
d6b0e80f AC |
2759 | num_events, random_selector); |
2760 | ||
d90e17a7 PA |
2761 | event_lp = iterate_over_lwps (filter, |
2762 | select_event_lwp_callback, | |
d6b0e80f AC |
2763 | &random_selector); |
2764 | } | |
2765 | ||
2766 | if (event_lp != NULL) | |
2767 | { | |
2768 | /* Switch the event LWP. */ | |
2769 | *orig_lp = event_lp; | |
2770 | *status = event_lp->status; | |
2771 | } | |
2772 | ||
2773 | /* Flush the wait status for the event LWP. */ | |
2774 | (*orig_lp)->status = 0; | |
2775 | } | |
2776 | ||
2777 | /* Return non-zero if LP has been resumed. */ | |
2778 | ||
2779 | static int | |
2780 | resumed_callback (struct lwp_info *lp, void *data) | |
2781 | { | |
2782 | return lp->resumed; | |
2783 | } | |
2784 | ||
12d9289a PA |
2785 | /* Stop an active thread, verify it still exists, then resume it. If |
2786 | the thread ends up with a pending status, then it is not resumed, | |
2787 | and *DATA (really a pointer to int), is set. */ | |
d6b0e80f AC |
2788 | |
2789 | static int | |
2790 | stop_and_resume_callback (struct lwp_info *lp, void *data) | |
2791 | { | |
25289eb2 | 2792 | if (!lp->stopped) |
d6b0e80f | 2793 | { |
25289eb2 PA |
2794 | ptid_t ptid = lp->ptid; |
2795 | ||
d6b0e80f AC |
2796 | stop_callback (lp, NULL); |
2797 | stop_wait_callback (lp, NULL); | |
25289eb2 PA |
2798 | |
2799 | /* Resume if the lwp still exists, and the core wanted it | |
2800 | running. */ | |
12d9289a PA |
2801 | lp = find_lwp_pid (ptid); |
2802 | if (lp != NULL) | |
25289eb2 | 2803 | { |
12d9289a | 2804 | if (lp->last_resume_kind == resume_stop |
8a99810d | 2805 | && !lwp_status_pending_p (lp)) |
12d9289a PA |
2806 | { |
2807 | /* The core wanted the LWP to stop. Even if it stopped | |
2808 | cleanly (with SIGSTOP), leave the event pending. */ | |
2809 | if (debug_linux_nat) | |
2810 | fprintf_unfiltered (gdb_stdlog, | |
2811 | "SARC: core wanted LWP %ld stopped " | |
2812 | "(leaving SIGSTOP pending)\n", | |
dfd4cc63 | 2813 | ptid_get_lwp (lp->ptid)); |
12d9289a PA |
2814 | lp->status = W_STOPCODE (SIGSTOP); |
2815 | } | |
2816 | ||
8a99810d | 2817 | if (!lwp_status_pending_p (lp)) |
12d9289a PA |
2818 | { |
2819 | if (debug_linux_nat) | |
2820 | fprintf_unfiltered (gdb_stdlog, | |
2821 | "SARC: re-resuming LWP %ld\n", | |
dfd4cc63 | 2822 | ptid_get_lwp (lp->ptid)); |
e5ef252a | 2823 | resume_lwp (lp, lp->step, GDB_SIGNAL_0); |
12d9289a PA |
2824 | } |
2825 | else | |
2826 | { | |
2827 | if (debug_linux_nat) | |
2828 | fprintf_unfiltered (gdb_stdlog, | |
2829 | "SARC: not re-resuming LWP %ld " | |
2830 | "(has pending)\n", | |
dfd4cc63 | 2831 | ptid_get_lwp (lp->ptid)); |
12d9289a | 2832 | } |
25289eb2 | 2833 | } |
d6b0e80f AC |
2834 | } |
2835 | return 0; | |
2836 | } | |
2837 | ||
02f3fc28 | 2838 | /* Check if we should go on and pass this event to common code. |
9c02b525 | 2839 | Return the affected lwp if we are, or NULL otherwise. */ |
12d9289a | 2840 | |
02f3fc28 | 2841 | static struct lwp_info * |
9c02b525 | 2842 | linux_nat_filter_event (int lwpid, int status) |
02f3fc28 PA |
2843 | { |
2844 | struct lwp_info *lp; | |
89a5711c | 2845 | int event = linux_ptrace_get_extended_event (status); |
02f3fc28 PA |
2846 | |
2847 | lp = find_lwp_pid (pid_to_ptid (lwpid)); | |
2848 | ||
2849 | /* Check for stop events reported by a process we didn't already | |
2850 | know about - anything not already in our LWP list. | |
2851 | ||
2852 | If we're expecting to receive stopped processes after | |
2853 | fork, vfork, and clone events, then we'll just add the | |
2854 | new one to our list and go back to waiting for the event | |
2855 | to be reported - the stopped process might be returned | |
0e5bf2a8 PA |
2856 | from waitpid before or after the event is. |
2857 | ||
2858 | But note the case of a non-leader thread exec'ing after the | |
2859 | leader having exited, and gone from our lists. The non-leader | |
2860 | thread changes its tid to the tgid. */ | |
2861 | ||
2862 | if (WIFSTOPPED (status) && lp == NULL | |
89a5711c | 2863 | && (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC)) |
0e5bf2a8 PA |
2864 | { |
2865 | /* A multi-thread exec after we had seen the leader exiting. */ | |
2866 | if (debug_linux_nat) | |
2867 | fprintf_unfiltered (gdb_stdlog, | |
2868 | "LLW: Re-adding thread group leader LWP %d.\n", | |
2869 | lwpid); | |
2870 | ||
dfd4cc63 | 2871 | lp = add_lwp (ptid_build (lwpid, lwpid, 0)); |
0e5bf2a8 PA |
2872 | lp->stopped = 1; |
2873 | lp->resumed = 1; | |
2874 | add_thread (lp->ptid); | |
2875 | } | |
2876 | ||
02f3fc28 PA |
2877 | if (WIFSTOPPED (status) && !lp) |
2878 | { | |
84636d28 | 2879 | add_to_pid_list (&stopped_pids, lwpid, status); |
02f3fc28 PA |
2880 | return NULL; |
2881 | } | |
2882 | ||
2883 | /* Make sure we don't report an event for the exit of an LWP not in | |
1777feb0 | 2884 | our list, i.e. not part of the current process. This can happen |
fd62cb89 | 2885 | if we detach from a program we originally forked and then it |
02f3fc28 PA |
2886 | exits. */ |
2887 | if (!WIFSTOPPED (status) && !lp) | |
2888 | return NULL; | |
2889 | ||
8817a6f2 PA |
2890 | /* This LWP is stopped now. (And if dead, this prevents it from |
2891 | ever being continued.) */ | |
2892 | lp->stopped = 1; | |
2893 | ||
8784d563 PA |
2894 | if (WIFSTOPPED (status) && lp->must_set_ptrace_flags) |
2895 | { | |
2896 | struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid)); | |
2897 | ||
2898 | linux_enable_event_reporting (ptid_get_lwp (lp->ptid), inf->attach_flag); | |
2899 | lp->must_set_ptrace_flags = 0; | |
2900 | } | |
2901 | ||
ca2163eb PA |
2902 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2903 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2904 | { | |
2905 | /* No longer need the sysgood bit. The ptrace event ends up | |
2906 | recorded in lp->waitstatus if we care for it. We can carry | |
2907 | on handling the event like a regular SIGTRAP from here | |
2908 | on. */ | |
2909 | status = W_STOPCODE (SIGTRAP); | |
2910 | if (linux_handle_syscall_trap (lp, 0)) | |
2911 | return NULL; | |
2912 | } | |
02f3fc28 | 2913 | |
ca2163eb | 2914 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2915 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2916 | && linux_is_extended_waitstatus (status)) | |
02f3fc28 PA |
2917 | { |
2918 | if (debug_linux_nat) | |
2919 | fprintf_unfiltered (gdb_stdlog, | |
2920 | "LLW: Handling extended status 0x%06x\n", | |
2921 | status); | |
2922 | if (linux_handle_extended_wait (lp, status, 0)) | |
2923 | return NULL; | |
2924 | } | |
2925 | ||
2926 | /* Check if the thread has exited. */ | |
9c02b525 PA |
2927 | if (WIFEXITED (status) || WIFSIGNALED (status)) |
2928 | { | |
2929 | if (num_lwps (ptid_get_pid (lp->ptid)) > 1) | |
02f3fc28 | 2930 | { |
9c02b525 PA |
2931 | /* If this is the main thread, we must stop all threads and |
2932 | verify if they are still alive. This is because in the | |
2933 | nptl thread model on Linux 2.4, there is no signal issued | |
2934 | for exiting LWPs other than the main thread. We only get | |
2935 | the main thread exit signal once all child threads have | |
2936 | already exited. If we stop all the threads and use the | |
2937 | stop_wait_callback to check if they have exited we can | |
2938 | determine whether this signal should be ignored or | |
2939 | whether it means the end of the debugged application, | |
2940 | regardless of which threading model is being used. */ | |
2941 | if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid)) | |
2942 | { | |
2943 | iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp->ptid)), | |
2944 | stop_and_resume_callback, NULL); | |
2945 | } | |
2946 | ||
2947 | if (debug_linux_nat) | |
2948 | fprintf_unfiltered (gdb_stdlog, | |
2949 | "LLW: %s exited.\n", | |
2950 | target_pid_to_str (lp->ptid)); | |
2951 | ||
2952 | if (num_lwps (ptid_get_pid (lp->ptid)) > 1) | |
2953 | { | |
2954 | /* If there is at least one more LWP, then the exit signal | |
2955 | was not the end of the debugged application and should be | |
2956 | ignored. */ | |
2957 | exit_lwp (lp); | |
2958 | return NULL; | |
2959 | } | |
02f3fc28 PA |
2960 | } |
2961 | ||
9c02b525 PA |
2962 | gdb_assert (lp->resumed); |
2963 | ||
02f3fc28 PA |
2964 | if (debug_linux_nat) |
2965 | fprintf_unfiltered (gdb_stdlog, | |
9c02b525 PA |
2966 | "Process %ld exited\n", |
2967 | ptid_get_lwp (lp->ptid)); | |
02f3fc28 | 2968 | |
9c02b525 PA |
2969 | /* This was the last lwp in the process. Since events are |
2970 | serialized to GDB core, we may not be able report this one | |
2971 | right now, but GDB core and the other target layers will want | |
2972 | to be notified about the exit code/signal, leave the status | |
2973 | pending for the next time we're able to report it. */ | |
2974 | ||
2975 | /* Dead LWP's aren't expected to reported a pending sigstop. */ | |
2976 | lp->signalled = 0; | |
2977 | ||
2978 | /* Store the pending event in the waitstatus, because | |
2979 | W_EXITCODE(0,0) == 0. */ | |
2980 | store_waitstatus (&lp->waitstatus, status); | |
2981 | return lp; | |
02f3fc28 PA |
2982 | } |
2983 | ||
2984 | /* Check if the current LWP has previously exited. In the nptl | |
2985 | thread model, LWPs other than the main thread do not issue | |
2986 | signals when they exit so we must check whenever the thread has | |
2987 | stopped. A similar check is made in stop_wait_callback(). */ | |
dfd4cc63 | 2988 | if (num_lwps (ptid_get_pid (lp->ptid)) > 1 && !linux_thread_alive (lp->ptid)) |
02f3fc28 | 2989 | { |
dfd4cc63 | 2990 | ptid_t ptid = pid_to_ptid (ptid_get_pid (lp->ptid)); |
d90e17a7 | 2991 | |
02f3fc28 PA |
2992 | if (debug_linux_nat) |
2993 | fprintf_unfiltered (gdb_stdlog, | |
2994 | "LLW: %s exited.\n", | |
2995 | target_pid_to_str (lp->ptid)); | |
2996 | ||
2997 | exit_lwp (lp); | |
2998 | ||
2999 | /* Make sure there is at least one thread running. */ | |
d90e17a7 | 3000 | gdb_assert (iterate_over_lwps (ptid, running_callback, NULL)); |
02f3fc28 PA |
3001 | |
3002 | /* Discard the event. */ | |
3003 | return NULL; | |
3004 | } | |
3005 | ||
3006 | /* Make sure we don't report a SIGSTOP that we sent ourselves in | |
3007 | an attempt to stop an LWP. */ | |
3008 | if (lp->signalled | |
3009 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) | |
3010 | { | |
3011 | if (debug_linux_nat) | |
3012 | fprintf_unfiltered (gdb_stdlog, | |
3013 | "LLW: Delayed SIGSTOP caught for %s.\n", | |
3014 | target_pid_to_str (lp->ptid)); | |
3015 | ||
02f3fc28 PA |
3016 | lp->signalled = 0; |
3017 | ||
25289eb2 PA |
3018 | if (lp->last_resume_kind != resume_stop) |
3019 | { | |
3020 | /* This is a delayed SIGSTOP. */ | |
02f3fc28 | 3021 | |
8a99810d | 3022 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
25289eb2 PA |
3023 | if (debug_linux_nat) |
3024 | fprintf_unfiltered (gdb_stdlog, | |
3025 | "LLW: %s %s, 0, 0 (discard SIGSTOP)\n", | |
3026 | lp->step ? | |
3027 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3028 | target_pid_to_str (lp->ptid)); | |
02f3fc28 | 3029 | |
25289eb2 | 3030 | gdb_assert (lp->resumed); |
02f3fc28 | 3031 | |
25289eb2 PA |
3032 | /* Discard the event. */ |
3033 | return NULL; | |
3034 | } | |
02f3fc28 PA |
3035 | } |
3036 | ||
57380f4e DJ |
3037 | /* Make sure we don't report a SIGINT that we have already displayed |
3038 | for another thread. */ | |
3039 | if (lp->ignore_sigint | |
3040 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) | |
3041 | { | |
3042 | if (debug_linux_nat) | |
3043 | fprintf_unfiltered (gdb_stdlog, | |
3044 | "LLW: Delayed SIGINT caught for %s.\n", | |
3045 | target_pid_to_str (lp->ptid)); | |
3046 | ||
3047 | /* This is a delayed SIGINT. */ | |
3048 | lp->ignore_sigint = 0; | |
3049 | ||
8a99810d | 3050 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
57380f4e DJ |
3051 | if (debug_linux_nat) |
3052 | fprintf_unfiltered (gdb_stdlog, | |
3053 | "LLW: %s %s, 0, 0 (discard SIGINT)\n", | |
3054 | lp->step ? | |
3055 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3056 | target_pid_to_str (lp->ptid)); | |
57380f4e DJ |
3057 | gdb_assert (lp->resumed); |
3058 | ||
3059 | /* Discard the event. */ | |
3060 | return NULL; | |
3061 | } | |
3062 | ||
9c02b525 PA |
3063 | /* Don't report signals that GDB isn't interested in, such as |
3064 | signals that are neither printed nor stopped upon. Stopping all | |
3065 | threads can be a bit time-consuming so if we want decent | |
3066 | performance with heavily multi-threaded programs, especially when | |
3067 | they're using a high frequency timer, we'd better avoid it if we | |
3068 | can. */ | |
3069 | if (WIFSTOPPED (status)) | |
3070 | { | |
3071 | enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status)); | |
3072 | ||
3073 | if (!non_stop) | |
3074 | { | |
3075 | /* Only do the below in all-stop, as we currently use SIGSTOP | |
3076 | to implement target_stop (see linux_nat_stop) in | |
3077 | non-stop. */ | |
3078 | if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0) | |
3079 | { | |
3080 | /* If ^C/BREAK is typed at the tty/console, SIGINT gets | |
3081 | forwarded to the entire process group, that is, all LWPs | |
3082 | will receive it - unless they're using CLONE_THREAD to | |
3083 | share signals. Since we only want to report it once, we | |
3084 | mark it as ignored for all LWPs except this one. */ | |
3085 | iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp->ptid)), | |
3086 | set_ignore_sigint, NULL); | |
3087 | lp->ignore_sigint = 0; | |
3088 | } | |
3089 | else | |
3090 | maybe_clear_ignore_sigint (lp); | |
3091 | } | |
3092 | ||
3093 | /* When using hardware single-step, we need to report every signal. | |
3094 | Otherwise, signals in pass_mask may be short-circuited. */ | |
3095 | if (!lp->step | |
3096 | && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status))) | |
3097 | { | |
3098 | linux_resume_one_lwp (lp, lp->step, signo); | |
3099 | if (debug_linux_nat) | |
3100 | fprintf_unfiltered (gdb_stdlog, | |
3101 | "LLW: %s %s, %s (preempt 'handle')\n", | |
3102 | lp->step ? | |
3103 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3104 | target_pid_to_str (lp->ptid), | |
3105 | (signo != GDB_SIGNAL_0 | |
3106 | ? strsignal (gdb_signal_to_host (signo)) | |
3107 | : "0")); | |
3108 | return NULL; | |
3109 | } | |
3110 | } | |
3111 | ||
02f3fc28 PA |
3112 | /* An interesting event. */ |
3113 | gdb_assert (lp); | |
ca2163eb | 3114 | lp->status = status; |
9c02b525 | 3115 | save_sigtrap (lp); |
02f3fc28 PA |
3116 | return lp; |
3117 | } | |
3118 | ||
0e5bf2a8 PA |
3119 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
3120 | their exits until all other threads in the group have exited. */ | |
3121 | ||
3122 | static void | |
3123 | check_zombie_leaders (void) | |
3124 | { | |
3125 | struct inferior *inf; | |
3126 | ||
3127 | ALL_INFERIORS (inf) | |
3128 | { | |
3129 | struct lwp_info *leader_lp; | |
3130 | ||
3131 | if (inf->pid == 0) | |
3132 | continue; | |
3133 | ||
3134 | leader_lp = find_lwp_pid (pid_to_ptid (inf->pid)); | |
3135 | if (leader_lp != NULL | |
3136 | /* Check if there are other threads in the group, as we may | |
3137 | have raced with the inferior simply exiting. */ | |
3138 | && num_lwps (inf->pid) > 1 | |
5f572dec | 3139 | && linux_proc_pid_is_zombie (inf->pid)) |
0e5bf2a8 PA |
3140 | { |
3141 | if (debug_linux_nat) | |
3142 | fprintf_unfiltered (gdb_stdlog, | |
3143 | "CZL: Thread group leader %d zombie " | |
3144 | "(it exited, or another thread execd).\n", | |
3145 | inf->pid); | |
3146 | ||
3147 | /* A leader zombie can mean one of two things: | |
3148 | ||
3149 | - It exited, and there's an exit status pending | |
3150 | available, or only the leader exited (not the whole | |
3151 | program). In the latter case, we can't waitpid the | |
3152 | leader's exit status until all other threads are gone. | |
3153 | ||
3154 | - There are 3 or more threads in the group, and a thread | |
3155 | other than the leader exec'd. On an exec, the Linux | |
3156 | kernel destroys all other threads (except the execing | |
3157 | one) in the thread group, and resets the execing thread's | |
3158 | tid to the tgid. No exit notification is sent for the | |
3159 | execing thread -- from the ptracer's perspective, it | |
3160 | appears as though the execing thread just vanishes. | |
3161 | Until we reap all other threads except the leader and the | |
3162 | execing thread, the leader will be zombie, and the | |
3163 | execing thread will be in `D (disc sleep)'. As soon as | |
3164 | all other threads are reaped, the execing thread changes | |
3165 | it's tid to the tgid, and the previous (zombie) leader | |
3166 | vanishes, giving place to the "new" leader. We could try | |
3167 | distinguishing the exit and exec cases, by waiting once | |
3168 | more, and seeing if something comes out, but it doesn't | |
3169 | sound useful. The previous leader _does_ go away, and | |
3170 | we'll re-add the new one once we see the exec event | |
3171 | (which is just the same as what would happen if the | |
3172 | previous leader did exit voluntarily before some other | |
3173 | thread execs). */ | |
3174 | ||
3175 | if (debug_linux_nat) | |
3176 | fprintf_unfiltered (gdb_stdlog, | |
3177 | "CZL: Thread group leader %d vanished.\n", | |
3178 | inf->pid); | |
3179 | exit_lwp (leader_lp); | |
3180 | } | |
3181 | } | |
3182 | } | |
3183 | ||
d6b0e80f | 3184 | static ptid_t |
7feb7d06 | 3185 | linux_nat_wait_1 (struct target_ops *ops, |
47608cb1 PA |
3186 | ptid_t ptid, struct target_waitstatus *ourstatus, |
3187 | int target_options) | |
d6b0e80f | 3188 | { |
fc9b8e47 | 3189 | sigset_t prev_mask; |
4b60df3d | 3190 | enum resume_kind last_resume_kind; |
12d9289a | 3191 | struct lwp_info *lp; |
12d9289a | 3192 | int status; |
d6b0e80f | 3193 | |
01124a23 | 3194 | if (debug_linux_nat) |
b84876c2 PA |
3195 | fprintf_unfiltered (gdb_stdlog, "LLW: enter\n"); |
3196 | ||
f973ed9c DJ |
3197 | /* The first time we get here after starting a new inferior, we may |
3198 | not have added it to the LWP list yet - this is the earliest | |
3199 | moment at which we know its PID. */ | |
d90e17a7 | 3200 | if (ptid_is_pid (inferior_ptid)) |
f973ed9c | 3201 | { |
27c9d204 PA |
3202 | /* Upgrade the main thread's ptid. */ |
3203 | thread_change_ptid (inferior_ptid, | |
dfd4cc63 LM |
3204 | ptid_build (ptid_get_pid (inferior_ptid), |
3205 | ptid_get_pid (inferior_ptid), 0)); | |
27c9d204 | 3206 | |
26cb8b7c | 3207 | lp = add_initial_lwp (inferior_ptid); |
f973ed9c DJ |
3208 | lp->resumed = 1; |
3209 | } | |
3210 | ||
12696c10 | 3211 | /* Make sure SIGCHLD is blocked until the sigsuspend below. */ |
7feb7d06 | 3212 | block_child_signals (&prev_mask); |
d6b0e80f | 3213 | |
d6b0e80f | 3214 | /* First check if there is a LWP with a wait status pending. */ |
8a99810d PA |
3215 | lp = iterate_over_lwps (ptid, status_callback, NULL); |
3216 | if (lp != NULL) | |
d6b0e80f AC |
3217 | { |
3218 | if (debug_linux_nat) | |
d6b0e80f AC |
3219 | fprintf_unfiltered (gdb_stdlog, |
3220 | "LLW: Using pending wait status %s for %s.\n", | |
ca2163eb | 3221 | status_to_str (lp->status), |
d6b0e80f | 3222 | target_pid_to_str (lp->ptid)); |
d6b0e80f AC |
3223 | } |
3224 | ||
b84876c2 PA |
3225 | if (!target_can_async_p ()) |
3226 | { | |
3227 | /* Causes SIGINT to be passed on to the attached process. */ | |
3228 | set_sigint_trap (); | |
b84876c2 | 3229 | } |
d6b0e80f | 3230 | |
9c02b525 PA |
3231 | /* But if we don't find a pending event, we'll have to wait. Always |
3232 | pull all events out of the kernel. We'll randomly select an | |
3233 | event LWP out of all that have events, to prevent starvation. */ | |
7feb7d06 | 3234 | |
d90e17a7 | 3235 | while (lp == NULL) |
d6b0e80f AC |
3236 | { |
3237 | pid_t lwpid; | |
3238 | ||
0e5bf2a8 PA |
3239 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
3240 | quirks: | |
3241 | ||
3242 | - If the thread group leader exits while other threads in the | |
3243 | thread group still exist, waitpid(TGID, ...) hangs. That | |
3244 | waitpid won't return an exit status until the other threads | |
3245 | in the group are reapped. | |
3246 | ||
3247 | - When a non-leader thread execs, that thread just vanishes | |
3248 | without reporting an exit (so we'd hang if we waited for it | |
3249 | explicitly in that case). The exec event is reported to | |
3250 | the TGID pid. */ | |
3251 | ||
3252 | errno = 0; | |
3253 | lwpid = my_waitpid (-1, &status, __WCLONE | WNOHANG); | |
3254 | if (lwpid == 0 || (lwpid == -1 && errno == ECHILD)) | |
3255 | lwpid = my_waitpid (-1, &status, WNOHANG); | |
3256 | ||
3257 | if (debug_linux_nat) | |
3258 | fprintf_unfiltered (gdb_stdlog, | |
3259 | "LNW: waitpid(-1, ...) returned %d, %s\n", | |
3260 | lwpid, errno ? safe_strerror (errno) : "ERRNO-OK"); | |
b84876c2 | 3261 | |
d6b0e80f AC |
3262 | if (lwpid > 0) |
3263 | { | |
d6b0e80f AC |
3264 | if (debug_linux_nat) |
3265 | { | |
3266 | fprintf_unfiltered (gdb_stdlog, | |
3267 | "LLW: waitpid %ld received %s\n", | |
3268 | (long) lwpid, status_to_str (status)); | |
3269 | } | |
3270 | ||
9c02b525 | 3271 | linux_nat_filter_event (lwpid, status); |
0e5bf2a8 PA |
3272 | /* Retry until nothing comes out of waitpid. A single |
3273 | SIGCHLD can indicate more than one child stopped. */ | |
3274 | continue; | |
d6b0e80f AC |
3275 | } |
3276 | ||
9c02b525 PA |
3277 | /* Now that we've pulled all events out of the kernel, check if |
3278 | there's any LWP with a status to report to the core. */ | |
3279 | lp = iterate_over_lwps (ptid, status_callback, NULL); | |
3280 | if (lp != NULL) | |
3281 | break; | |
3282 | ||
0e5bf2a8 PA |
3283 | /* Check for zombie thread group leaders. Those can't be reaped |
3284 | until all other threads in the thread group are. */ | |
3285 | check_zombie_leaders (); | |
d6b0e80f | 3286 | |
0e5bf2a8 PA |
3287 | /* If there are no resumed children left, bail. We'd be stuck |
3288 | forever in the sigsuspend call below otherwise. */ | |
3289 | if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL) | |
3290 | { | |
3291 | if (debug_linux_nat) | |
3292 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n"); | |
b84876c2 | 3293 | |
0e5bf2a8 | 3294 | ourstatus->kind = TARGET_WAITKIND_NO_RESUMED; |
b84876c2 | 3295 | |
0e5bf2a8 PA |
3296 | if (!target_can_async_p ()) |
3297 | clear_sigint_trap (); | |
b84876c2 | 3298 | |
0e5bf2a8 PA |
3299 | restore_child_signals_mask (&prev_mask); |
3300 | return minus_one_ptid; | |
d6b0e80f | 3301 | } |
28736962 | 3302 | |
0e5bf2a8 PA |
3303 | /* No interesting event to report to the core. */ |
3304 | ||
3305 | if (target_options & TARGET_WNOHANG) | |
3306 | { | |
01124a23 | 3307 | if (debug_linux_nat) |
28736962 PA |
3308 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n"); |
3309 | ||
0e5bf2a8 | 3310 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
28736962 PA |
3311 | restore_child_signals_mask (&prev_mask); |
3312 | return minus_one_ptid; | |
3313 | } | |
d6b0e80f AC |
3314 | |
3315 | /* We shouldn't end up here unless we want to try again. */ | |
d90e17a7 | 3316 | gdb_assert (lp == NULL); |
0e5bf2a8 PA |
3317 | |
3318 | /* Block until we get an event reported with SIGCHLD. */ | |
d36bf488 DE |
3319 | if (debug_linux_nat) |
3320 | fprintf_unfiltered (gdb_stdlog, "LNW: about to sigsuspend\n"); | |
0e5bf2a8 | 3321 | sigsuspend (&suspend_mask); |
d6b0e80f AC |
3322 | } |
3323 | ||
b84876c2 | 3324 | if (!target_can_async_p ()) |
d26b5354 | 3325 | clear_sigint_trap (); |
d6b0e80f AC |
3326 | |
3327 | gdb_assert (lp); | |
3328 | ||
ca2163eb PA |
3329 | status = lp->status; |
3330 | lp->status = 0; | |
3331 | ||
4c28f408 PA |
3332 | if (!non_stop) |
3333 | { | |
3334 | /* Now stop all other LWP's ... */ | |
d90e17a7 | 3335 | iterate_over_lwps (minus_one_ptid, stop_callback, NULL); |
4c28f408 PA |
3336 | |
3337 | /* ... and wait until all of them have reported back that | |
3338 | they're no longer running. */ | |
d90e17a7 | 3339 | iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL); |
9c02b525 PA |
3340 | } |
3341 | ||
3342 | /* If we're not waiting for a specific LWP, choose an event LWP from | |
3343 | among those that have had events. Giving equal priority to all | |
3344 | LWPs that have had events helps prevent starvation. */ | |
3345 | if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) | |
3346 | select_event_lwp (ptid, &lp, &status); | |
3347 | ||
3348 | gdb_assert (lp != NULL); | |
3349 | ||
3350 | /* Now that we've selected our final event LWP, un-adjust its PC if | |
3351 | it was a software breakpoint. */ | |
3352 | if (lp->stop_reason == LWP_STOPPED_BY_SW_BREAKPOINT) | |
3353 | { | |
3354 | struct regcache *regcache = get_thread_regcache (lp->ptid); | |
3355 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
3356 | int decr_pc = target_decr_pc_after_break (gdbarch); | |
4c28f408 | 3357 | |
9c02b525 PA |
3358 | if (decr_pc != 0) |
3359 | { | |
3360 | CORE_ADDR pc; | |
d6b0e80f | 3361 | |
9c02b525 PA |
3362 | pc = regcache_read_pc (regcache); |
3363 | regcache_write_pc (regcache, pc + decr_pc); | |
3364 | } | |
3365 | } | |
e3e9f5a2 | 3366 | |
9c02b525 PA |
3367 | /* We'll need this to determine whether to report a SIGSTOP as |
3368 | GDB_SIGNAL_0. Need to take a copy because resume_clear_callback | |
3369 | clears it. */ | |
3370 | last_resume_kind = lp->last_resume_kind; | |
4b60df3d | 3371 | |
9c02b525 PA |
3372 | if (!non_stop) |
3373 | { | |
e3e9f5a2 PA |
3374 | /* In all-stop, from the core's perspective, all LWPs are now |
3375 | stopped until a new resume action is sent over. */ | |
3376 | iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL); | |
3377 | } | |
3378 | else | |
25289eb2 | 3379 | { |
4b60df3d | 3380 | resume_clear_callback (lp, NULL); |
25289eb2 | 3381 | } |
d6b0e80f | 3382 | |
26ab7092 | 3383 | if (linux_nat_status_is_event (status)) |
d6b0e80f | 3384 | { |
d6b0e80f AC |
3385 | if (debug_linux_nat) |
3386 | fprintf_unfiltered (gdb_stdlog, | |
4fdebdd0 PA |
3387 | "LLW: trap ptid is %s.\n", |
3388 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 3389 | } |
d6b0e80f AC |
3390 | |
3391 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
3392 | { | |
3393 | *ourstatus = lp->waitstatus; | |
3394 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
3395 | } | |
3396 | else | |
3397 | store_waitstatus (ourstatus, status); | |
3398 | ||
01124a23 | 3399 | if (debug_linux_nat) |
b84876c2 PA |
3400 | fprintf_unfiltered (gdb_stdlog, "LLW: exit\n"); |
3401 | ||
7feb7d06 | 3402 | restore_child_signals_mask (&prev_mask); |
1e225492 | 3403 | |
4b60df3d | 3404 | if (last_resume_kind == resume_stop |
25289eb2 PA |
3405 | && ourstatus->kind == TARGET_WAITKIND_STOPPED |
3406 | && WSTOPSIG (status) == SIGSTOP) | |
3407 | { | |
3408 | /* A thread that has been requested to stop by GDB with | |
3409 | target_stop, and it stopped cleanly, so report as SIG0. The | |
3410 | use of SIGSTOP is an implementation detail. */ | |
a493e3e2 | 3411 | ourstatus->value.sig = GDB_SIGNAL_0; |
25289eb2 PA |
3412 | } |
3413 | ||
1e225492 JK |
3414 | if (ourstatus->kind == TARGET_WAITKIND_EXITED |
3415 | || ourstatus->kind == TARGET_WAITKIND_SIGNALLED) | |
3416 | lp->core = -1; | |
3417 | else | |
2e794194 | 3418 | lp->core = linux_common_core_of_thread (lp->ptid); |
1e225492 | 3419 | |
f973ed9c | 3420 | return lp->ptid; |
d6b0e80f AC |
3421 | } |
3422 | ||
e3e9f5a2 PA |
3423 | /* Resume LWPs that are currently stopped without any pending status |
3424 | to report, but are resumed from the core's perspective. */ | |
3425 | ||
3426 | static int | |
3427 | resume_stopped_resumed_lwps (struct lwp_info *lp, void *data) | |
3428 | { | |
3429 | ptid_t *wait_ptid_p = data; | |
3430 | ||
3431 | if (lp->stopped | |
3432 | && lp->resumed | |
8a99810d | 3433 | && !lwp_status_pending_p (lp)) |
e3e9f5a2 | 3434 | { |
336060f3 PA |
3435 | struct regcache *regcache = get_thread_regcache (lp->ptid); |
3436 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
3437 | CORE_ADDR pc = regcache_read_pc (regcache); | |
3438 | ||
e3e9f5a2 PA |
3439 | gdb_assert (is_executing (lp->ptid)); |
3440 | ||
3441 | /* Don't bother if there's a breakpoint at PC that we'd hit | |
3442 | immediately, and we're not waiting for this LWP. */ | |
3443 | if (!ptid_match (lp->ptid, *wait_ptid_p)) | |
3444 | { | |
e3e9f5a2 PA |
3445 | if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
3446 | return 0; | |
3447 | } | |
3448 | ||
3449 | if (debug_linux_nat) | |
3450 | fprintf_unfiltered (gdb_stdlog, | |
336060f3 PA |
3451 | "RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n", |
3452 | target_pid_to_str (lp->ptid), | |
3453 | paddress (gdbarch, pc), | |
3454 | lp->step); | |
e3e9f5a2 | 3455 | |
8a99810d | 3456 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
e3e9f5a2 PA |
3457 | } |
3458 | ||
3459 | return 0; | |
3460 | } | |
3461 | ||
7feb7d06 PA |
3462 | static ptid_t |
3463 | linux_nat_wait (struct target_ops *ops, | |
47608cb1 PA |
3464 | ptid_t ptid, struct target_waitstatus *ourstatus, |
3465 | int target_options) | |
7feb7d06 PA |
3466 | { |
3467 | ptid_t event_ptid; | |
3468 | ||
3469 | if (debug_linux_nat) | |
09826ec5 PA |
3470 | { |
3471 | char *options_string; | |
3472 | ||
3473 | options_string = target_options_to_string (target_options); | |
3474 | fprintf_unfiltered (gdb_stdlog, | |
3475 | "linux_nat_wait: [%s], [%s]\n", | |
3476 | target_pid_to_str (ptid), | |
3477 | options_string); | |
3478 | xfree (options_string); | |
3479 | } | |
7feb7d06 PA |
3480 | |
3481 | /* Flush the async file first. */ | |
3482 | if (target_can_async_p ()) | |
3483 | async_file_flush (); | |
3484 | ||
e3e9f5a2 PA |
3485 | /* Resume LWPs that are currently stopped without any pending status |
3486 | to report, but are resumed from the core's perspective. LWPs get | |
3487 | in this state if we find them stopping at a time we're not | |
3488 | interested in reporting the event (target_wait on a | |
3489 | specific_process, for example, see linux_nat_wait_1), and | |
3490 | meanwhile the event became uninteresting. Don't bother resuming | |
3491 | LWPs we're not going to wait for if they'd stop immediately. */ | |
3492 | if (non_stop) | |
3493 | iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid); | |
3494 | ||
47608cb1 | 3495 | event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options); |
7feb7d06 PA |
3496 | |
3497 | /* If we requested any event, and something came out, assume there | |
3498 | may be more. If we requested a specific lwp or process, also | |
3499 | assume there may be more. */ | |
3500 | if (target_can_async_p () | |
6953d224 PA |
3501 | && ((ourstatus->kind != TARGET_WAITKIND_IGNORE |
3502 | && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED) | |
7feb7d06 PA |
3503 | || !ptid_equal (ptid, minus_one_ptid))) |
3504 | async_file_mark (); | |
3505 | ||
3506 | /* Get ready for the next event. */ | |
3507 | if (target_can_async_p ()) | |
3508 | target_async (inferior_event_handler, 0); | |
3509 | ||
3510 | return event_ptid; | |
3511 | } | |
3512 | ||
d6b0e80f AC |
3513 | static int |
3514 | kill_callback (struct lwp_info *lp, void *data) | |
3515 | { | |
ed731959 JK |
3516 | /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
3517 | ||
3518 | errno = 0; | |
69ff6be5 | 3519 | kill_lwp (ptid_get_lwp (lp->ptid), SIGKILL); |
ed731959 | 3520 | if (debug_linux_nat) |
57745c90 PA |
3521 | { |
3522 | int save_errno = errno; | |
3523 | ||
3524 | fprintf_unfiltered (gdb_stdlog, | |
3525 | "KC: kill (SIGKILL) %s, 0, 0 (%s)\n", | |
3526 | target_pid_to_str (lp->ptid), | |
3527 | save_errno ? safe_strerror (save_errno) : "OK"); | |
3528 | } | |
ed731959 JK |
3529 | |
3530 | /* Some kernels ignore even SIGKILL for processes under ptrace. */ | |
3531 | ||
d6b0e80f | 3532 | errno = 0; |
dfd4cc63 | 3533 | ptrace (PTRACE_KILL, ptid_get_lwp (lp->ptid), 0, 0); |
d6b0e80f | 3534 | if (debug_linux_nat) |
57745c90 PA |
3535 | { |
3536 | int save_errno = errno; | |
3537 | ||
3538 | fprintf_unfiltered (gdb_stdlog, | |
3539 | "KC: PTRACE_KILL %s, 0, 0 (%s)\n", | |
3540 | target_pid_to_str (lp->ptid), | |
3541 | save_errno ? safe_strerror (save_errno) : "OK"); | |
3542 | } | |
d6b0e80f AC |
3543 | |
3544 | return 0; | |
3545 | } | |
3546 | ||
3547 | static int | |
3548 | kill_wait_callback (struct lwp_info *lp, void *data) | |
3549 | { | |
3550 | pid_t pid; | |
3551 | ||
3552 | /* We must make sure that there are no pending events (delayed | |
3553 | SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current | |
3554 | program doesn't interfere with any following debugging session. */ | |
3555 | ||
3556 | /* For cloned processes we must check both with __WCLONE and | |
3557 | without, since the exit status of a cloned process isn't reported | |
3558 | with __WCLONE. */ | |
3559 | if (lp->cloned) | |
3560 | { | |
3561 | do | |
3562 | { | |
dfd4cc63 | 3563 | pid = my_waitpid (ptid_get_lwp (lp->ptid), NULL, __WCLONE); |
e85a822c | 3564 | if (pid != (pid_t) -1) |
d6b0e80f | 3565 | { |
e85a822c DJ |
3566 | if (debug_linux_nat) |
3567 | fprintf_unfiltered (gdb_stdlog, | |
3568 | "KWC: wait %s received unknown.\n", | |
3569 | target_pid_to_str (lp->ptid)); | |
3570 | /* The Linux kernel sometimes fails to kill a thread | |
3571 | completely after PTRACE_KILL; that goes from the stop | |
3572 | point in do_fork out to the one in | |
3573 | get_signal_to_deliever and waits again. So kill it | |
3574 | again. */ | |
3575 | kill_callback (lp, NULL); | |
d6b0e80f AC |
3576 | } |
3577 | } | |
dfd4cc63 | 3578 | while (pid == ptid_get_lwp (lp->ptid)); |
d6b0e80f AC |
3579 | |
3580 | gdb_assert (pid == -1 && errno == ECHILD); | |
3581 | } | |
3582 | ||
3583 | do | |
3584 | { | |
dfd4cc63 | 3585 | pid = my_waitpid (ptid_get_lwp (lp->ptid), NULL, 0); |
e85a822c | 3586 | if (pid != (pid_t) -1) |
d6b0e80f | 3587 | { |
e85a822c DJ |
3588 | if (debug_linux_nat) |
3589 | fprintf_unfiltered (gdb_stdlog, | |
3590 | "KWC: wait %s received unk.\n", | |
3591 | target_pid_to_str (lp->ptid)); | |
3592 | /* See the call to kill_callback above. */ | |
3593 | kill_callback (lp, NULL); | |
d6b0e80f AC |
3594 | } |
3595 | } | |
dfd4cc63 | 3596 | while (pid == ptid_get_lwp (lp->ptid)); |
d6b0e80f AC |
3597 | |
3598 | gdb_assert (pid == -1 && errno == ECHILD); | |
3599 | return 0; | |
3600 | } | |
3601 | ||
3602 | static void | |
7d85a9c0 | 3603 | linux_nat_kill (struct target_ops *ops) |
d6b0e80f | 3604 | { |
f973ed9c DJ |
3605 | struct target_waitstatus last; |
3606 | ptid_t last_ptid; | |
3607 | int status; | |
d6b0e80f | 3608 | |
f973ed9c DJ |
3609 | /* If we're stopped while forking and we haven't followed yet, |
3610 | kill the other task. We need to do this first because the | |
3611 | parent will be sleeping if this is a vfork. */ | |
d6b0e80f | 3612 | |
f973ed9c | 3613 | get_last_target_status (&last_ptid, &last); |
d6b0e80f | 3614 | |
f973ed9c DJ |
3615 | if (last.kind == TARGET_WAITKIND_FORKED |
3616 | || last.kind == TARGET_WAITKIND_VFORKED) | |
3617 | { | |
dfd4cc63 | 3618 | ptrace (PT_KILL, ptid_get_pid (last.value.related_pid), 0, 0); |
f973ed9c | 3619 | wait (&status); |
26cb8b7c PA |
3620 | |
3621 | /* Let the arch-specific native code know this process is | |
3622 | gone. */ | |
dfd4cc63 | 3623 | linux_nat_forget_process (ptid_get_pid (last.value.related_pid)); |
f973ed9c DJ |
3624 | } |
3625 | ||
3626 | if (forks_exist_p ()) | |
7feb7d06 | 3627 | linux_fork_killall (); |
f973ed9c DJ |
3628 | else |
3629 | { | |
d90e17a7 | 3630 | ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid)); |
e0881a8e | 3631 | |
4c28f408 PA |
3632 | /* Stop all threads before killing them, since ptrace requires |
3633 | that the thread is stopped to sucessfully PTRACE_KILL. */ | |
d90e17a7 | 3634 | iterate_over_lwps (ptid, stop_callback, NULL); |
4c28f408 PA |
3635 | /* ... and wait until all of them have reported back that |
3636 | they're no longer running. */ | |
d90e17a7 | 3637 | iterate_over_lwps (ptid, stop_wait_callback, NULL); |
4c28f408 | 3638 | |
f973ed9c | 3639 | /* Kill all LWP's ... */ |
d90e17a7 | 3640 | iterate_over_lwps (ptid, kill_callback, NULL); |
f973ed9c DJ |
3641 | |
3642 | /* ... and wait until we've flushed all events. */ | |
d90e17a7 | 3643 | iterate_over_lwps (ptid, kill_wait_callback, NULL); |
f973ed9c DJ |
3644 | } |
3645 | ||
3646 | target_mourn_inferior (); | |
d6b0e80f AC |
3647 | } |
3648 | ||
3649 | static void | |
136d6dae | 3650 | linux_nat_mourn_inferior (struct target_ops *ops) |
d6b0e80f | 3651 | { |
26cb8b7c PA |
3652 | int pid = ptid_get_pid (inferior_ptid); |
3653 | ||
3654 | purge_lwp_list (pid); | |
d6b0e80f | 3655 | |
f973ed9c | 3656 | if (! forks_exist_p ()) |
d90e17a7 PA |
3657 | /* Normal case, no other forks available. */ |
3658 | linux_ops->to_mourn_inferior (ops); | |
f973ed9c DJ |
3659 | else |
3660 | /* Multi-fork case. The current inferior_ptid has exited, but | |
3661 | there are other viable forks to debug. Delete the exiting | |
3662 | one and context-switch to the first available. */ | |
3663 | linux_fork_mourn_inferior (); | |
26cb8b7c PA |
3664 | |
3665 | /* Let the arch-specific native code know this process is gone. */ | |
3666 | linux_nat_forget_process (pid); | |
d6b0e80f AC |
3667 | } |
3668 | ||
5b009018 PA |
3669 | /* Convert a native/host siginfo object, into/from the siginfo in the |
3670 | layout of the inferiors' architecture. */ | |
3671 | ||
3672 | static void | |
a5362b9a | 3673 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
5b009018 PA |
3674 | { |
3675 | int done = 0; | |
3676 | ||
3677 | if (linux_nat_siginfo_fixup != NULL) | |
3678 | done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction); | |
3679 | ||
3680 | /* If there was no callback, or the callback didn't do anything, | |
3681 | then just do a straight memcpy. */ | |
3682 | if (!done) | |
3683 | { | |
3684 | if (direction == 1) | |
a5362b9a | 3685 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
5b009018 | 3686 | else |
a5362b9a | 3687 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
5b009018 PA |
3688 | } |
3689 | } | |
3690 | ||
9b409511 | 3691 | static enum target_xfer_status |
4aa995e1 PA |
3692 | linux_xfer_siginfo (struct target_ops *ops, enum target_object object, |
3693 | const char *annex, gdb_byte *readbuf, | |
9b409511 YQ |
3694 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
3695 | ULONGEST *xfered_len) | |
4aa995e1 | 3696 | { |
4aa995e1 | 3697 | int pid; |
a5362b9a TS |
3698 | siginfo_t siginfo; |
3699 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; | |
4aa995e1 PA |
3700 | |
3701 | gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO); | |
3702 | gdb_assert (readbuf || writebuf); | |
3703 | ||
dfd4cc63 | 3704 | pid = ptid_get_lwp (inferior_ptid); |
4aa995e1 | 3705 | if (pid == 0) |
dfd4cc63 | 3706 | pid = ptid_get_pid (inferior_ptid); |
4aa995e1 PA |
3707 | |
3708 | if (offset > sizeof (siginfo)) | |
2ed4b548 | 3709 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3710 | |
3711 | errno = 0; | |
3712 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3713 | if (errno != 0) | |
2ed4b548 | 3714 | return TARGET_XFER_E_IO; |
4aa995e1 | 3715 | |
5b009018 PA |
3716 | /* When GDB is built as a 64-bit application, ptrace writes into |
3717 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
3718 | inferior with a 64-bit GDB should look the same as debugging it | |
3719 | with a 32-bit GDB, we need to convert it. GDB core always sees | |
3720 | the converted layout, so any read/write will have to be done | |
3721 | post-conversion. */ | |
3722 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
3723 | ||
4aa995e1 PA |
3724 | if (offset + len > sizeof (siginfo)) |
3725 | len = sizeof (siginfo) - offset; | |
3726 | ||
3727 | if (readbuf != NULL) | |
5b009018 | 3728 | memcpy (readbuf, inf_siginfo + offset, len); |
4aa995e1 PA |
3729 | else |
3730 | { | |
5b009018 PA |
3731 | memcpy (inf_siginfo + offset, writebuf, len); |
3732 | ||
3733 | /* Convert back to ptrace layout before flushing it out. */ | |
3734 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
3735 | ||
4aa995e1 PA |
3736 | errno = 0; |
3737 | ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3738 | if (errno != 0) | |
2ed4b548 | 3739 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3740 | } |
3741 | ||
9b409511 YQ |
3742 | *xfered_len = len; |
3743 | return TARGET_XFER_OK; | |
4aa995e1 PA |
3744 | } |
3745 | ||
9b409511 | 3746 | static enum target_xfer_status |
10d6c8cd DJ |
3747 | linux_nat_xfer_partial (struct target_ops *ops, enum target_object object, |
3748 | const char *annex, gdb_byte *readbuf, | |
3749 | const gdb_byte *writebuf, | |
9b409511 | 3750 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) |
d6b0e80f | 3751 | { |
4aa995e1 | 3752 | struct cleanup *old_chain; |
9b409511 | 3753 | enum target_xfer_status xfer; |
d6b0e80f | 3754 | |
4aa995e1 PA |
3755 | if (object == TARGET_OBJECT_SIGNAL_INFO) |
3756 | return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf, | |
9b409511 | 3757 | offset, len, xfered_len); |
4aa995e1 | 3758 | |
c35b1492 PA |
3759 | /* The target is connected but no live inferior is selected. Pass |
3760 | this request down to a lower stratum (e.g., the executable | |
3761 | file). */ | |
3762 | if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid)) | |
9b409511 | 3763 | return TARGET_XFER_EOF; |
c35b1492 | 3764 | |
4aa995e1 PA |
3765 | old_chain = save_inferior_ptid (); |
3766 | ||
dfd4cc63 LM |
3767 | if (ptid_lwp_p (inferior_ptid)) |
3768 | inferior_ptid = pid_to_ptid (ptid_get_lwp (inferior_ptid)); | |
d6b0e80f | 3769 | |
10d6c8cd | 3770 | xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf, |
9b409511 | 3771 | offset, len, xfered_len); |
d6b0e80f AC |
3772 | |
3773 | do_cleanups (old_chain); | |
3774 | return xfer; | |
3775 | } | |
3776 | ||
3777 | static int | |
28439f5e | 3778 | linux_thread_alive (ptid_t ptid) |
d6b0e80f | 3779 | { |
8c6a60d1 | 3780 | int err, tmp_errno; |
4c28f408 | 3781 | |
dfd4cc63 | 3782 | gdb_assert (ptid_lwp_p (ptid)); |
d6b0e80f | 3783 | |
4c28f408 PA |
3784 | /* Send signal 0 instead of anything ptrace, because ptracing a |
3785 | running thread errors out claiming that the thread doesn't | |
3786 | exist. */ | |
dfd4cc63 | 3787 | err = kill_lwp (ptid_get_lwp (ptid), 0); |
8c6a60d1 | 3788 | tmp_errno = errno; |
d6b0e80f AC |
3789 | if (debug_linux_nat) |
3790 | fprintf_unfiltered (gdb_stdlog, | |
4c28f408 | 3791 | "LLTA: KILL(SIG0) %s (%s)\n", |
d6b0e80f | 3792 | target_pid_to_str (ptid), |
8c6a60d1 | 3793 | err ? safe_strerror (tmp_errno) : "OK"); |
9c0dd46b | 3794 | |
4c28f408 | 3795 | if (err != 0) |
d6b0e80f AC |
3796 | return 0; |
3797 | ||
3798 | return 1; | |
3799 | } | |
3800 | ||
28439f5e PA |
3801 | static int |
3802 | linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid) | |
3803 | { | |
3804 | return linux_thread_alive (ptid); | |
3805 | } | |
3806 | ||
d6b0e80f | 3807 | static char * |
117de6a9 | 3808 | linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid) |
d6b0e80f AC |
3809 | { |
3810 | static char buf[64]; | |
3811 | ||
dfd4cc63 LM |
3812 | if (ptid_lwp_p (ptid) |
3813 | && (ptid_get_pid (ptid) != ptid_get_lwp (ptid) | |
3814 | || num_lwps (ptid_get_pid (ptid)) > 1)) | |
d6b0e80f | 3815 | { |
dfd4cc63 | 3816 | snprintf (buf, sizeof (buf), "LWP %ld", ptid_get_lwp (ptid)); |
d6b0e80f AC |
3817 | return buf; |
3818 | } | |
3819 | ||
3820 | return normal_pid_to_str (ptid); | |
3821 | } | |
3822 | ||
4694da01 | 3823 | static char * |
503a628d | 3824 | linux_nat_thread_name (struct target_ops *self, struct thread_info *thr) |
4694da01 TT |
3825 | { |
3826 | int pid = ptid_get_pid (thr->ptid); | |
3827 | long lwp = ptid_get_lwp (thr->ptid); | |
3828 | #define FORMAT "/proc/%d/task/%ld/comm" | |
3829 | char buf[sizeof (FORMAT) + 30]; | |
3830 | FILE *comm_file; | |
3831 | char *result = NULL; | |
3832 | ||
3833 | snprintf (buf, sizeof (buf), FORMAT, pid, lwp); | |
614c279d | 3834 | comm_file = gdb_fopen_cloexec (buf, "r"); |
4694da01 TT |
3835 | if (comm_file) |
3836 | { | |
3837 | /* Not exported by the kernel, so we define it here. */ | |
3838 | #define COMM_LEN 16 | |
3839 | static char line[COMM_LEN + 1]; | |
3840 | ||
3841 | if (fgets (line, sizeof (line), comm_file)) | |
3842 | { | |
3843 | char *nl = strchr (line, '\n'); | |
3844 | ||
3845 | if (nl) | |
3846 | *nl = '\0'; | |
3847 | if (*line != '\0') | |
3848 | result = line; | |
3849 | } | |
3850 | ||
3851 | fclose (comm_file); | |
3852 | } | |
3853 | ||
3854 | #undef COMM_LEN | |
3855 | #undef FORMAT | |
3856 | ||
3857 | return result; | |
3858 | } | |
3859 | ||
dba24537 AC |
3860 | /* Accepts an integer PID; Returns a string representing a file that |
3861 | can be opened to get the symbols for the child process. */ | |
3862 | ||
6d8fd2b7 | 3863 | static char * |
8dd27370 | 3864 | linux_child_pid_to_exec_file (struct target_ops *self, int pid) |
dba24537 | 3865 | { |
b4ab256d HZ |
3866 | static char buf[PATH_MAX]; |
3867 | char name[PATH_MAX]; | |
dba24537 | 3868 | |
b4ab256d HZ |
3869 | xsnprintf (name, PATH_MAX, "/proc/%d/exe", pid); |
3870 | memset (buf, 0, PATH_MAX); | |
3871 | if (readlink (name, buf, PATH_MAX - 1) <= 0) | |
3872 | strcpy (buf, name); | |
dba24537 | 3873 | |
b4ab256d | 3874 | return buf; |
dba24537 AC |
3875 | } |
3876 | ||
10d6c8cd DJ |
3877 | /* Implement the to_xfer_partial interface for memory reads using the /proc |
3878 | filesystem. Because we can use a single read() call for /proc, this | |
3879 | can be much more efficient than banging away at PTRACE_PEEKTEXT, | |
3880 | but it doesn't support writes. */ | |
3881 | ||
9b409511 | 3882 | static enum target_xfer_status |
10d6c8cd DJ |
3883 | linux_proc_xfer_partial (struct target_ops *ops, enum target_object object, |
3884 | const char *annex, gdb_byte *readbuf, | |
3885 | const gdb_byte *writebuf, | |
9b409511 | 3886 | ULONGEST offset, LONGEST len, ULONGEST *xfered_len) |
dba24537 | 3887 | { |
10d6c8cd DJ |
3888 | LONGEST ret; |
3889 | int fd; | |
dba24537 AC |
3890 | char filename[64]; |
3891 | ||
10d6c8cd | 3892 | if (object != TARGET_OBJECT_MEMORY || !readbuf) |
dba24537 AC |
3893 | return 0; |
3894 | ||
3895 | /* Don't bother for one word. */ | |
3896 | if (len < 3 * sizeof (long)) | |
9b409511 | 3897 | return TARGET_XFER_EOF; |
dba24537 AC |
3898 | |
3899 | /* We could keep this file open and cache it - possibly one per | |
3900 | thread. That requires some juggling, but is even faster. */ | |
cde33bf1 YQ |
3901 | xsnprintf (filename, sizeof filename, "/proc/%d/mem", |
3902 | ptid_get_pid (inferior_ptid)); | |
614c279d | 3903 | fd = gdb_open_cloexec (filename, O_RDONLY | O_LARGEFILE, 0); |
dba24537 | 3904 | if (fd == -1) |
9b409511 | 3905 | return TARGET_XFER_EOF; |
dba24537 AC |
3906 | |
3907 | /* If pread64 is available, use it. It's faster if the kernel | |
3908 | supports it (only one syscall), and it's 64-bit safe even on | |
3909 | 32-bit platforms (for instance, SPARC debugging a SPARC64 | |
3910 | application). */ | |
3911 | #ifdef HAVE_PREAD64 | |
10d6c8cd | 3912 | if (pread64 (fd, readbuf, len, offset) != len) |
dba24537 | 3913 | #else |
10d6c8cd | 3914 | if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len) |
dba24537 AC |
3915 | #endif |
3916 | ret = 0; | |
3917 | else | |
3918 | ret = len; | |
3919 | ||
3920 | close (fd); | |
9b409511 YQ |
3921 | |
3922 | if (ret == 0) | |
3923 | return TARGET_XFER_EOF; | |
3924 | else | |
3925 | { | |
3926 | *xfered_len = ret; | |
3927 | return TARGET_XFER_OK; | |
3928 | } | |
dba24537 AC |
3929 | } |
3930 | ||
efcbbd14 UW |
3931 | |
3932 | /* Enumerate spufs IDs for process PID. */ | |
3933 | static LONGEST | |
b55e14c7 | 3934 | spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, ULONGEST len) |
efcbbd14 | 3935 | { |
f5656ead | 3936 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
efcbbd14 UW |
3937 | LONGEST pos = 0; |
3938 | LONGEST written = 0; | |
3939 | char path[128]; | |
3940 | DIR *dir; | |
3941 | struct dirent *entry; | |
3942 | ||
3943 | xsnprintf (path, sizeof path, "/proc/%d/fd", pid); | |
3944 | dir = opendir (path); | |
3945 | if (!dir) | |
3946 | return -1; | |
3947 | ||
3948 | rewinddir (dir); | |
3949 | while ((entry = readdir (dir)) != NULL) | |
3950 | { | |
3951 | struct stat st; | |
3952 | struct statfs stfs; | |
3953 | int fd; | |
3954 | ||
3955 | fd = atoi (entry->d_name); | |
3956 | if (!fd) | |
3957 | continue; | |
3958 | ||
3959 | xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd); | |
3960 | if (stat (path, &st) != 0) | |
3961 | continue; | |
3962 | if (!S_ISDIR (st.st_mode)) | |
3963 | continue; | |
3964 | ||
3965 | if (statfs (path, &stfs) != 0) | |
3966 | continue; | |
3967 | if (stfs.f_type != SPUFS_MAGIC) | |
3968 | continue; | |
3969 | ||
3970 | if (pos >= offset && pos + 4 <= offset + len) | |
3971 | { | |
3972 | store_unsigned_integer (buf + pos - offset, 4, byte_order, fd); | |
3973 | written += 4; | |
3974 | } | |
3975 | pos += 4; | |
3976 | } | |
3977 | ||
3978 | closedir (dir); | |
3979 | return written; | |
3980 | } | |
3981 | ||
3982 | /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU | |
3983 | object type, using the /proc file system. */ | |
9b409511 YQ |
3984 | |
3985 | static enum target_xfer_status | |
efcbbd14 UW |
3986 | linux_proc_xfer_spu (struct target_ops *ops, enum target_object object, |
3987 | const char *annex, gdb_byte *readbuf, | |
3988 | const gdb_byte *writebuf, | |
9b409511 | 3989 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) |
efcbbd14 UW |
3990 | { |
3991 | char buf[128]; | |
3992 | int fd = 0; | |
3993 | int ret = -1; | |
dfd4cc63 | 3994 | int pid = ptid_get_pid (inferior_ptid); |
efcbbd14 UW |
3995 | |
3996 | if (!annex) | |
3997 | { | |
3998 | if (!readbuf) | |
2ed4b548 | 3999 | return TARGET_XFER_E_IO; |
efcbbd14 | 4000 | else |
9b409511 YQ |
4001 | { |
4002 | LONGEST l = spu_enumerate_spu_ids (pid, readbuf, offset, len); | |
4003 | ||
4004 | if (l < 0) | |
4005 | return TARGET_XFER_E_IO; | |
4006 | else if (l == 0) | |
4007 | return TARGET_XFER_EOF; | |
4008 | else | |
4009 | { | |
4010 | *xfered_len = (ULONGEST) l; | |
4011 | return TARGET_XFER_OK; | |
4012 | } | |
4013 | } | |
efcbbd14 UW |
4014 | } |
4015 | ||
4016 | xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex); | |
614c279d | 4017 | fd = gdb_open_cloexec (buf, writebuf? O_WRONLY : O_RDONLY, 0); |
efcbbd14 | 4018 | if (fd <= 0) |
2ed4b548 | 4019 | return TARGET_XFER_E_IO; |
efcbbd14 UW |
4020 | |
4021 | if (offset != 0 | |
4022 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) | |
4023 | { | |
4024 | close (fd); | |
9b409511 | 4025 | return TARGET_XFER_EOF; |
efcbbd14 UW |
4026 | } |
4027 | ||
4028 | if (writebuf) | |
4029 | ret = write (fd, writebuf, (size_t) len); | |
4030 | else if (readbuf) | |
4031 | ret = read (fd, readbuf, (size_t) len); | |
4032 | ||
4033 | close (fd); | |
9b409511 YQ |
4034 | |
4035 | if (ret < 0) | |
4036 | return TARGET_XFER_E_IO; | |
4037 | else if (ret == 0) | |
4038 | return TARGET_XFER_EOF; | |
4039 | else | |
4040 | { | |
4041 | *xfered_len = (ULONGEST) ret; | |
4042 | return TARGET_XFER_OK; | |
4043 | } | |
efcbbd14 UW |
4044 | } |
4045 | ||
4046 | ||
dba24537 AC |
4047 | /* Parse LINE as a signal set and add its set bits to SIGS. */ |
4048 | ||
4049 | static void | |
4050 | add_line_to_sigset (const char *line, sigset_t *sigs) | |
4051 | { | |
4052 | int len = strlen (line) - 1; | |
4053 | const char *p; | |
4054 | int signum; | |
4055 | ||
4056 | if (line[len] != '\n') | |
8a3fe4f8 | 4057 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4058 | |
4059 | p = line; | |
4060 | signum = len * 4; | |
4061 | while (len-- > 0) | |
4062 | { | |
4063 | int digit; | |
4064 | ||
4065 | if (*p >= '0' && *p <= '9') | |
4066 | digit = *p - '0'; | |
4067 | else if (*p >= 'a' && *p <= 'f') | |
4068 | digit = *p - 'a' + 10; | |
4069 | else | |
8a3fe4f8 | 4070 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4071 | |
4072 | signum -= 4; | |
4073 | ||
4074 | if (digit & 1) | |
4075 | sigaddset (sigs, signum + 1); | |
4076 | if (digit & 2) | |
4077 | sigaddset (sigs, signum + 2); | |
4078 | if (digit & 4) | |
4079 | sigaddset (sigs, signum + 3); | |
4080 | if (digit & 8) | |
4081 | sigaddset (sigs, signum + 4); | |
4082 | ||
4083 | p++; | |
4084 | } | |
4085 | } | |
4086 | ||
4087 | /* Find process PID's pending signals from /proc/pid/status and set | |
4088 | SIGS to match. */ | |
4089 | ||
4090 | void | |
3e43a32a MS |
4091 | linux_proc_pending_signals (int pid, sigset_t *pending, |
4092 | sigset_t *blocked, sigset_t *ignored) | |
dba24537 AC |
4093 | { |
4094 | FILE *procfile; | |
d8d2a3ee | 4095 | char buffer[PATH_MAX], fname[PATH_MAX]; |
7c8a8b04 | 4096 | struct cleanup *cleanup; |
dba24537 AC |
4097 | |
4098 | sigemptyset (pending); | |
4099 | sigemptyset (blocked); | |
4100 | sigemptyset (ignored); | |
cde33bf1 | 4101 | xsnprintf (fname, sizeof fname, "/proc/%d/status", pid); |
614c279d | 4102 | procfile = gdb_fopen_cloexec (fname, "r"); |
dba24537 | 4103 | if (procfile == NULL) |
8a3fe4f8 | 4104 | error (_("Could not open %s"), fname); |
7c8a8b04 | 4105 | cleanup = make_cleanup_fclose (procfile); |
dba24537 | 4106 | |
d8d2a3ee | 4107 | while (fgets (buffer, PATH_MAX, procfile) != NULL) |
dba24537 AC |
4108 | { |
4109 | /* Normal queued signals are on the SigPnd line in the status | |
4110 | file. However, 2.6 kernels also have a "shared" pending | |
4111 | queue for delivering signals to a thread group, so check for | |
4112 | a ShdPnd line also. | |
4113 | ||
4114 | Unfortunately some Red Hat kernels include the shared pending | |
4115 | queue but not the ShdPnd status field. */ | |
4116 | ||
4117 | if (strncmp (buffer, "SigPnd:\t", 8) == 0) | |
4118 | add_line_to_sigset (buffer + 8, pending); | |
4119 | else if (strncmp (buffer, "ShdPnd:\t", 8) == 0) | |
4120 | add_line_to_sigset (buffer + 8, pending); | |
4121 | else if (strncmp (buffer, "SigBlk:\t", 8) == 0) | |
4122 | add_line_to_sigset (buffer + 8, blocked); | |
4123 | else if (strncmp (buffer, "SigIgn:\t", 8) == 0) | |
4124 | add_line_to_sigset (buffer + 8, ignored); | |
4125 | } | |
4126 | ||
7c8a8b04 | 4127 | do_cleanups (cleanup); |
dba24537 AC |
4128 | } |
4129 | ||
9b409511 | 4130 | static enum target_xfer_status |
07e059b5 | 4131 | linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object, |
e0881a8e | 4132 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
4133 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
4134 | ULONGEST *xfered_len) | |
07e059b5 | 4135 | { |
07e059b5 VP |
4136 | gdb_assert (object == TARGET_OBJECT_OSDATA); |
4137 | ||
9b409511 YQ |
4138 | *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len); |
4139 | if (*xfered_len == 0) | |
4140 | return TARGET_XFER_EOF; | |
4141 | else | |
4142 | return TARGET_XFER_OK; | |
07e059b5 VP |
4143 | } |
4144 | ||
9b409511 | 4145 | static enum target_xfer_status |
10d6c8cd DJ |
4146 | linux_xfer_partial (struct target_ops *ops, enum target_object object, |
4147 | const char *annex, gdb_byte *readbuf, | |
9b409511 YQ |
4148 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
4149 | ULONGEST *xfered_len) | |
10d6c8cd | 4150 | { |
9b409511 | 4151 | enum target_xfer_status xfer; |
10d6c8cd DJ |
4152 | |
4153 | if (object == TARGET_OBJECT_AUXV) | |
9f2982ff | 4154 | return memory_xfer_auxv (ops, object, annex, readbuf, writebuf, |
9b409511 | 4155 | offset, len, xfered_len); |
10d6c8cd | 4156 | |
07e059b5 VP |
4157 | if (object == TARGET_OBJECT_OSDATA) |
4158 | return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf, | |
9b409511 | 4159 | offset, len, xfered_len); |
07e059b5 | 4160 | |
efcbbd14 UW |
4161 | if (object == TARGET_OBJECT_SPU) |
4162 | return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf, | |
9b409511 | 4163 | offset, len, xfered_len); |
efcbbd14 | 4164 | |
8f313923 JK |
4165 | /* GDB calculates all the addresses in possibly larget width of the address. |
4166 | Address width needs to be masked before its final use - either by | |
4167 | linux_proc_xfer_partial or inf_ptrace_xfer_partial. | |
4168 | ||
4169 | Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ | |
4170 | ||
4171 | if (object == TARGET_OBJECT_MEMORY) | |
4172 | { | |
f5656ead | 4173 | int addr_bit = gdbarch_addr_bit (target_gdbarch ()); |
8f313923 JK |
4174 | |
4175 | if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) | |
4176 | offset &= ((ULONGEST) 1 << addr_bit) - 1; | |
4177 | } | |
4178 | ||
10d6c8cd | 4179 | xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf, |
9b409511 YQ |
4180 | offset, len, xfered_len); |
4181 | if (xfer != TARGET_XFER_EOF) | |
10d6c8cd DJ |
4182 | return xfer; |
4183 | ||
4184 | return super_xfer_partial (ops, object, annex, readbuf, writebuf, | |
9b409511 | 4185 | offset, len, xfered_len); |
10d6c8cd DJ |
4186 | } |
4187 | ||
5808517f YQ |
4188 | static void |
4189 | cleanup_target_stop (void *arg) | |
4190 | { | |
4191 | ptid_t *ptid = (ptid_t *) arg; | |
4192 | ||
4193 | gdb_assert (arg != NULL); | |
4194 | ||
4195 | /* Unpause all */ | |
a493e3e2 | 4196 | target_resume (*ptid, 0, GDB_SIGNAL_0); |
5808517f YQ |
4197 | } |
4198 | ||
4199 | static VEC(static_tracepoint_marker_p) * | |
c686c57f TT |
4200 | linux_child_static_tracepoint_markers_by_strid (struct target_ops *self, |
4201 | const char *strid) | |
5808517f YQ |
4202 | { |
4203 | char s[IPA_CMD_BUF_SIZE]; | |
4204 | struct cleanup *old_chain; | |
4205 | int pid = ptid_get_pid (inferior_ptid); | |
4206 | VEC(static_tracepoint_marker_p) *markers = NULL; | |
4207 | struct static_tracepoint_marker *marker = NULL; | |
4208 | char *p = s; | |
4209 | ptid_t ptid = ptid_build (pid, 0, 0); | |
4210 | ||
4211 | /* Pause all */ | |
4212 | target_stop (ptid); | |
4213 | ||
4214 | memcpy (s, "qTfSTM", sizeof ("qTfSTM")); | |
4215 | s[sizeof ("qTfSTM")] = 0; | |
4216 | ||
42476b70 | 4217 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4218 | |
4219 | old_chain = make_cleanup (free_current_marker, &marker); | |
4220 | make_cleanup (cleanup_target_stop, &ptid); | |
4221 | ||
4222 | while (*p++ == 'm') | |
4223 | { | |
4224 | if (marker == NULL) | |
4225 | marker = XCNEW (struct static_tracepoint_marker); | |
4226 | ||
4227 | do | |
4228 | { | |
4229 | parse_static_tracepoint_marker_definition (p, &p, marker); | |
4230 | ||
4231 | if (strid == NULL || strcmp (strid, marker->str_id) == 0) | |
4232 | { | |
4233 | VEC_safe_push (static_tracepoint_marker_p, | |
4234 | markers, marker); | |
4235 | marker = NULL; | |
4236 | } | |
4237 | else | |
4238 | { | |
4239 | release_static_tracepoint_marker (marker); | |
4240 | memset (marker, 0, sizeof (*marker)); | |
4241 | } | |
4242 | } | |
4243 | while (*p++ == ','); /* comma-separated list */ | |
4244 | ||
4245 | memcpy (s, "qTsSTM", sizeof ("qTsSTM")); | |
4246 | s[sizeof ("qTsSTM")] = 0; | |
42476b70 | 4247 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4248 | p = s; |
4249 | } | |
4250 | ||
4251 | do_cleanups (old_chain); | |
4252 | ||
4253 | return markers; | |
4254 | } | |
4255 | ||
e9efe249 | 4256 | /* Create a prototype generic GNU/Linux target. The client can override |
10d6c8cd DJ |
4257 | it with local methods. */ |
4258 | ||
910122bf UW |
4259 | static void |
4260 | linux_target_install_ops (struct target_ops *t) | |
10d6c8cd | 4261 | { |
6d8fd2b7 | 4262 | t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint; |
eb73ad13 | 4263 | t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint; |
6d8fd2b7 | 4264 | t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint; |
eb73ad13 | 4265 | t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint; |
6d8fd2b7 | 4266 | t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint; |
eb73ad13 | 4267 | t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint; |
a96d9b2e | 4268 | t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint; |
6d8fd2b7 | 4269 | t->to_pid_to_exec_file = linux_child_pid_to_exec_file; |
10d6c8cd | 4270 | t->to_post_startup_inferior = linux_child_post_startup_inferior; |
6d8fd2b7 UW |
4271 | t->to_post_attach = linux_child_post_attach; |
4272 | t->to_follow_fork = linux_child_follow_fork; | |
10d6c8cd DJ |
4273 | |
4274 | super_xfer_partial = t->to_xfer_partial; | |
4275 | t->to_xfer_partial = linux_xfer_partial; | |
5808517f YQ |
4276 | |
4277 | t->to_static_tracepoint_markers_by_strid | |
4278 | = linux_child_static_tracepoint_markers_by_strid; | |
910122bf UW |
4279 | } |
4280 | ||
4281 | struct target_ops * | |
4282 | linux_target (void) | |
4283 | { | |
4284 | struct target_ops *t; | |
4285 | ||
4286 | t = inf_ptrace_target (); | |
4287 | linux_target_install_ops (t); | |
4288 | ||
4289 | return t; | |
4290 | } | |
4291 | ||
4292 | struct target_ops * | |
7714d83a | 4293 | linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int)) |
910122bf UW |
4294 | { |
4295 | struct target_ops *t; | |
4296 | ||
4297 | t = inf_ptrace_trad_target (register_u_offset); | |
4298 | linux_target_install_ops (t); | |
10d6c8cd | 4299 | |
10d6c8cd DJ |
4300 | return t; |
4301 | } | |
4302 | ||
b84876c2 PA |
4303 | /* target_is_async_p implementation. */ |
4304 | ||
4305 | static int | |
6a109b6b | 4306 | linux_nat_is_async_p (struct target_ops *ops) |
b84876c2 | 4307 | { |
198297aa | 4308 | return linux_is_async_p (); |
b84876c2 PA |
4309 | } |
4310 | ||
4311 | /* target_can_async_p implementation. */ | |
4312 | ||
4313 | static int | |
6a109b6b | 4314 | linux_nat_can_async_p (struct target_ops *ops) |
b84876c2 PA |
4315 | { |
4316 | /* NOTE: palves 2008-03-21: We're only async when the user requests | |
7feb7d06 | 4317 | it explicitly with the "set target-async" command. |
b84876c2 | 4318 | Someday, linux will always be async. */ |
3dd5b83d | 4319 | return target_async_permitted; |
b84876c2 PA |
4320 | } |
4321 | ||
9908b566 | 4322 | static int |
2a9a2795 | 4323 | linux_nat_supports_non_stop (struct target_ops *self) |
9908b566 VP |
4324 | { |
4325 | return 1; | |
4326 | } | |
4327 | ||
d90e17a7 PA |
4328 | /* True if we want to support multi-process. To be removed when GDB |
4329 | supports multi-exec. */ | |
4330 | ||
2277426b | 4331 | int linux_multi_process = 1; |
d90e17a7 PA |
4332 | |
4333 | static int | |
86ce2668 | 4334 | linux_nat_supports_multi_process (struct target_ops *self) |
d90e17a7 PA |
4335 | { |
4336 | return linux_multi_process; | |
4337 | } | |
4338 | ||
03583c20 | 4339 | static int |
2bfc0540 | 4340 | linux_nat_supports_disable_randomization (struct target_ops *self) |
03583c20 UW |
4341 | { |
4342 | #ifdef HAVE_PERSONALITY | |
4343 | return 1; | |
4344 | #else | |
4345 | return 0; | |
4346 | #endif | |
4347 | } | |
4348 | ||
b84876c2 PA |
4349 | static int async_terminal_is_ours = 1; |
4350 | ||
4d4ca2a1 DE |
4351 | /* target_terminal_inferior implementation. |
4352 | ||
4353 | This is a wrapper around child_terminal_inferior to add async support. */ | |
b84876c2 PA |
4354 | |
4355 | static void | |
d2f640d4 | 4356 | linux_nat_terminal_inferior (struct target_ops *self) |
b84876c2 | 4357 | { |
198297aa PA |
4358 | /* Like target_terminal_inferior, use target_can_async_p, not |
4359 | target_is_async_p, since at this point the target is not async | |
4360 | yet. If it can async, then we know it will become async prior to | |
4361 | resume. */ | |
4362 | if (!target_can_async_p ()) | |
b84876c2 PA |
4363 | { |
4364 | /* Async mode is disabled. */ | |
d6b64346 | 4365 | child_terminal_inferior (self); |
b84876c2 PA |
4366 | return; |
4367 | } | |
4368 | ||
d6b64346 | 4369 | child_terminal_inferior (self); |
b84876c2 | 4370 | |
d9d2d8b6 | 4371 | /* Calls to target_terminal_*() are meant to be idempotent. */ |
b84876c2 PA |
4372 | if (!async_terminal_is_ours) |
4373 | return; | |
4374 | ||
4375 | delete_file_handler (input_fd); | |
4376 | async_terminal_is_ours = 0; | |
4377 | set_sigint_trap (); | |
4378 | } | |
4379 | ||
4d4ca2a1 DE |
4380 | /* target_terminal_ours implementation. |
4381 | ||
4382 | This is a wrapper around child_terminal_ours to add async support (and | |
4383 | implement the target_terminal_ours vs target_terminal_ours_for_output | |
4384 | distinction). child_terminal_ours is currently no different than | |
4385 | child_terminal_ours_for_output. | |
4386 | We leave target_terminal_ours_for_output alone, leaving it to | |
4387 | child_terminal_ours_for_output. */ | |
b84876c2 | 4388 | |
2c0b251b | 4389 | static void |
e3594fd1 | 4390 | linux_nat_terminal_ours (struct target_ops *self) |
b84876c2 | 4391 | { |
b84876c2 PA |
4392 | /* GDB should never give the terminal to the inferior if the |
4393 | inferior is running in the background (run&, continue&, etc.), | |
4394 | but claiming it sure should. */ | |
d6b64346 | 4395 | child_terminal_ours (self); |
b84876c2 | 4396 | |
b84876c2 PA |
4397 | if (async_terminal_is_ours) |
4398 | return; | |
4399 | ||
4400 | clear_sigint_trap (); | |
4401 | add_file_handler (input_fd, stdin_event_handler, 0); | |
4402 | async_terminal_is_ours = 1; | |
4403 | } | |
4404 | ||
4405 | static void (*async_client_callback) (enum inferior_event_type event_type, | |
4406 | void *context); | |
4407 | static void *async_client_context; | |
4408 | ||
7feb7d06 PA |
4409 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
4410 | so we notice when any child changes state, and notify the | |
4411 | event-loop; it allows us to use sigsuspend in linux_nat_wait_1 | |
4412 | above to wait for the arrival of a SIGCHLD. */ | |
4413 | ||
b84876c2 | 4414 | static void |
7feb7d06 | 4415 | sigchld_handler (int signo) |
b84876c2 | 4416 | { |
7feb7d06 PA |
4417 | int old_errno = errno; |
4418 | ||
01124a23 DE |
4419 | if (debug_linux_nat) |
4420 | ui_file_write_async_safe (gdb_stdlog, | |
4421 | "sigchld\n", sizeof ("sigchld\n") - 1); | |
7feb7d06 PA |
4422 | |
4423 | if (signo == SIGCHLD | |
4424 | && linux_nat_event_pipe[0] != -1) | |
4425 | async_file_mark (); /* Let the event loop know that there are | |
4426 | events to handle. */ | |
4427 | ||
4428 | errno = old_errno; | |
4429 | } | |
4430 | ||
4431 | /* Callback registered with the target events file descriptor. */ | |
4432 | ||
4433 | static void | |
4434 | handle_target_event (int error, gdb_client_data client_data) | |
4435 | { | |
4436 | (*async_client_callback) (INF_REG_EVENT, async_client_context); | |
4437 | } | |
4438 | ||
4439 | /* Create/destroy the target events pipe. Returns previous state. */ | |
4440 | ||
4441 | static int | |
4442 | linux_async_pipe (int enable) | |
4443 | { | |
198297aa | 4444 | int previous = linux_is_async_p (); |
7feb7d06 PA |
4445 | |
4446 | if (previous != enable) | |
4447 | { | |
4448 | sigset_t prev_mask; | |
4449 | ||
12696c10 PA |
4450 | /* Block child signals while we create/destroy the pipe, as |
4451 | their handler writes to it. */ | |
7feb7d06 PA |
4452 | block_child_signals (&prev_mask); |
4453 | ||
4454 | if (enable) | |
4455 | { | |
614c279d | 4456 | if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1) |
7feb7d06 PA |
4457 | internal_error (__FILE__, __LINE__, |
4458 | "creating event pipe failed."); | |
4459 | ||
4460 | fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK); | |
4461 | fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK); | |
4462 | } | |
4463 | else | |
4464 | { | |
4465 | close (linux_nat_event_pipe[0]); | |
4466 | close (linux_nat_event_pipe[1]); | |
4467 | linux_nat_event_pipe[0] = -1; | |
4468 | linux_nat_event_pipe[1] = -1; | |
4469 | } | |
4470 | ||
4471 | restore_child_signals_mask (&prev_mask); | |
4472 | } | |
4473 | ||
4474 | return previous; | |
b84876c2 PA |
4475 | } |
4476 | ||
4477 | /* target_async implementation. */ | |
4478 | ||
4479 | static void | |
6a109b6b TT |
4480 | linux_nat_async (struct target_ops *ops, |
4481 | void (*callback) (enum inferior_event_type event_type, | |
4482 | void *context), | |
4483 | void *context) | |
b84876c2 | 4484 | { |
b84876c2 PA |
4485 | if (callback != NULL) |
4486 | { | |
4487 | async_client_callback = callback; | |
4488 | async_client_context = context; | |
7feb7d06 PA |
4489 | if (!linux_async_pipe (1)) |
4490 | { | |
4491 | add_file_handler (linux_nat_event_pipe[0], | |
4492 | handle_target_event, NULL); | |
4493 | /* There may be pending events to handle. Tell the event loop | |
4494 | to poll them. */ | |
4495 | async_file_mark (); | |
4496 | } | |
b84876c2 PA |
4497 | } |
4498 | else | |
4499 | { | |
4500 | async_client_callback = callback; | |
4501 | async_client_context = context; | |
b84876c2 | 4502 | delete_file_handler (linux_nat_event_pipe[0]); |
7feb7d06 | 4503 | linux_async_pipe (0); |
b84876c2 PA |
4504 | } |
4505 | return; | |
4506 | } | |
4507 | ||
a493e3e2 | 4508 | /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other |
252fbfc8 PA |
4509 | event came out. */ |
4510 | ||
4c28f408 | 4511 | static int |
252fbfc8 | 4512 | linux_nat_stop_lwp (struct lwp_info *lwp, void *data) |
4c28f408 | 4513 | { |
d90e17a7 | 4514 | if (!lwp->stopped) |
252fbfc8 | 4515 | { |
d90e17a7 PA |
4516 | if (debug_linux_nat) |
4517 | fprintf_unfiltered (gdb_stdlog, | |
4518 | "LNSL: running -> suspending %s\n", | |
4519 | target_pid_to_str (lwp->ptid)); | |
252fbfc8 | 4520 | |
252fbfc8 | 4521 | |
25289eb2 PA |
4522 | if (lwp->last_resume_kind == resume_stop) |
4523 | { | |
4524 | if (debug_linux_nat) | |
4525 | fprintf_unfiltered (gdb_stdlog, | |
4526 | "linux-nat: already stopping LWP %ld at " | |
4527 | "GDB's request\n", | |
4528 | ptid_get_lwp (lwp->ptid)); | |
4529 | return 0; | |
4530 | } | |
252fbfc8 | 4531 | |
25289eb2 PA |
4532 | stop_callback (lwp, NULL); |
4533 | lwp->last_resume_kind = resume_stop; | |
d90e17a7 PA |
4534 | } |
4535 | else | |
4536 | { | |
4537 | /* Already known to be stopped; do nothing. */ | |
252fbfc8 | 4538 | |
d90e17a7 PA |
4539 | if (debug_linux_nat) |
4540 | { | |
e09875d4 | 4541 | if (find_thread_ptid (lwp->ptid)->stop_requested) |
3e43a32a MS |
4542 | fprintf_unfiltered (gdb_stdlog, |
4543 | "LNSL: already stopped/stop_requested %s\n", | |
d90e17a7 PA |
4544 | target_pid_to_str (lwp->ptid)); |
4545 | else | |
3e43a32a MS |
4546 | fprintf_unfiltered (gdb_stdlog, |
4547 | "LNSL: already stopped/no " | |
4548 | "stop_requested yet %s\n", | |
d90e17a7 | 4549 | target_pid_to_str (lwp->ptid)); |
252fbfc8 PA |
4550 | } |
4551 | } | |
4c28f408 PA |
4552 | return 0; |
4553 | } | |
4554 | ||
4555 | static void | |
1eab8a48 | 4556 | linux_nat_stop (struct target_ops *self, ptid_t ptid) |
4c28f408 PA |
4557 | { |
4558 | if (non_stop) | |
d90e17a7 | 4559 | iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL); |
4c28f408 | 4560 | else |
1eab8a48 | 4561 | linux_ops->to_stop (linux_ops, ptid); |
4c28f408 PA |
4562 | } |
4563 | ||
d90e17a7 | 4564 | static void |
de90e03d | 4565 | linux_nat_close (struct target_ops *self) |
d90e17a7 PA |
4566 | { |
4567 | /* Unregister from the event loop. */ | |
9debeba0 DE |
4568 | if (linux_nat_is_async_p (self)) |
4569 | linux_nat_async (self, NULL, NULL); | |
d90e17a7 | 4570 | |
d90e17a7 | 4571 | if (linux_ops->to_close) |
de90e03d | 4572 | linux_ops->to_close (linux_ops); |
6a3cb8e8 PA |
4573 | |
4574 | super_close (self); | |
d90e17a7 PA |
4575 | } |
4576 | ||
c0694254 PA |
4577 | /* When requests are passed down from the linux-nat layer to the |
4578 | single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are | |
4579 | used. The address space pointer is stored in the inferior object, | |
4580 | but the common code that is passed such ptid can't tell whether | |
4581 | lwpid is a "main" process id or not (it assumes so). We reverse | |
4582 | look up the "main" process id from the lwp here. */ | |
4583 | ||
70221824 | 4584 | static struct address_space * |
c0694254 PA |
4585 | linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid) |
4586 | { | |
4587 | struct lwp_info *lwp; | |
4588 | struct inferior *inf; | |
4589 | int pid; | |
4590 | ||
dfd4cc63 | 4591 | if (ptid_get_lwp (ptid) == 0) |
c0694254 PA |
4592 | { |
4593 | /* An (lwpid,0,0) ptid. Look up the lwp object to get at the | |
4594 | tgid. */ | |
4595 | lwp = find_lwp_pid (ptid); | |
dfd4cc63 | 4596 | pid = ptid_get_pid (lwp->ptid); |
c0694254 PA |
4597 | } |
4598 | else | |
4599 | { | |
4600 | /* A (pid,lwpid,0) ptid. */ | |
dfd4cc63 | 4601 | pid = ptid_get_pid (ptid); |
c0694254 PA |
4602 | } |
4603 | ||
4604 | inf = find_inferior_pid (pid); | |
4605 | gdb_assert (inf != NULL); | |
4606 | return inf->aspace; | |
4607 | } | |
4608 | ||
dc146f7c VP |
4609 | /* Return the cached value of the processor core for thread PTID. */ |
4610 | ||
70221824 | 4611 | static int |
dc146f7c VP |
4612 | linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid) |
4613 | { | |
4614 | struct lwp_info *info = find_lwp_pid (ptid); | |
e0881a8e | 4615 | |
dc146f7c VP |
4616 | if (info) |
4617 | return info->core; | |
4618 | return -1; | |
4619 | } | |
4620 | ||
f973ed9c DJ |
4621 | void |
4622 | linux_nat_add_target (struct target_ops *t) | |
4623 | { | |
f973ed9c DJ |
4624 | /* Save the provided single-threaded target. We save this in a separate |
4625 | variable because another target we've inherited from (e.g. inf-ptrace) | |
4626 | may have saved a pointer to T; we want to use it for the final | |
4627 | process stratum target. */ | |
4628 | linux_ops_saved = *t; | |
4629 | linux_ops = &linux_ops_saved; | |
4630 | ||
4631 | /* Override some methods for multithreading. */ | |
b84876c2 | 4632 | t->to_create_inferior = linux_nat_create_inferior; |
f973ed9c DJ |
4633 | t->to_attach = linux_nat_attach; |
4634 | t->to_detach = linux_nat_detach; | |
4635 | t->to_resume = linux_nat_resume; | |
4636 | t->to_wait = linux_nat_wait; | |
2455069d | 4637 | t->to_pass_signals = linux_nat_pass_signals; |
f973ed9c DJ |
4638 | t->to_xfer_partial = linux_nat_xfer_partial; |
4639 | t->to_kill = linux_nat_kill; | |
4640 | t->to_mourn_inferior = linux_nat_mourn_inferior; | |
4641 | t->to_thread_alive = linux_nat_thread_alive; | |
4642 | t->to_pid_to_str = linux_nat_pid_to_str; | |
4694da01 | 4643 | t->to_thread_name = linux_nat_thread_name; |
f973ed9c | 4644 | t->to_has_thread_control = tc_schedlock; |
c0694254 | 4645 | t->to_thread_address_space = linux_nat_thread_address_space; |
ebec9a0f PA |
4646 | t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint; |
4647 | t->to_stopped_data_address = linux_nat_stopped_data_address; | |
f973ed9c | 4648 | |
b84876c2 PA |
4649 | t->to_can_async_p = linux_nat_can_async_p; |
4650 | t->to_is_async_p = linux_nat_is_async_p; | |
9908b566 | 4651 | t->to_supports_non_stop = linux_nat_supports_non_stop; |
b84876c2 | 4652 | t->to_async = linux_nat_async; |
b84876c2 PA |
4653 | t->to_terminal_inferior = linux_nat_terminal_inferior; |
4654 | t->to_terminal_ours = linux_nat_terminal_ours; | |
6a3cb8e8 PA |
4655 | |
4656 | super_close = t->to_close; | |
d90e17a7 | 4657 | t->to_close = linux_nat_close; |
b84876c2 | 4658 | |
4c28f408 PA |
4659 | /* Methods for non-stop support. */ |
4660 | t->to_stop = linux_nat_stop; | |
4661 | ||
d90e17a7 PA |
4662 | t->to_supports_multi_process = linux_nat_supports_multi_process; |
4663 | ||
03583c20 UW |
4664 | t->to_supports_disable_randomization |
4665 | = linux_nat_supports_disable_randomization; | |
4666 | ||
dc146f7c VP |
4667 | t->to_core_of_thread = linux_nat_core_of_thread; |
4668 | ||
f973ed9c DJ |
4669 | /* We don't change the stratum; this target will sit at |
4670 | process_stratum and thread_db will set at thread_stratum. This | |
4671 | is a little strange, since this is a multi-threaded-capable | |
4672 | target, but we want to be on the stack below thread_db, and we | |
4673 | also want to be used for single-threaded processes. */ | |
4674 | ||
4675 | add_target (t); | |
f973ed9c DJ |
4676 | } |
4677 | ||
9f0bdab8 DJ |
4678 | /* Register a method to call whenever a new thread is attached. */ |
4679 | void | |
7b50312a PA |
4680 | linux_nat_set_new_thread (struct target_ops *t, |
4681 | void (*new_thread) (struct lwp_info *)) | |
9f0bdab8 DJ |
4682 | { |
4683 | /* Save the pointer. We only support a single registered instance | |
4684 | of the GNU/Linux native target, so we do not need to map this to | |
4685 | T. */ | |
4686 | linux_nat_new_thread = new_thread; | |
4687 | } | |
4688 | ||
26cb8b7c PA |
4689 | /* See declaration in linux-nat.h. */ |
4690 | ||
4691 | void | |
4692 | linux_nat_set_new_fork (struct target_ops *t, | |
4693 | linux_nat_new_fork_ftype *new_fork) | |
4694 | { | |
4695 | /* Save the pointer. */ | |
4696 | linux_nat_new_fork = new_fork; | |
4697 | } | |
4698 | ||
4699 | /* See declaration in linux-nat.h. */ | |
4700 | ||
4701 | void | |
4702 | linux_nat_set_forget_process (struct target_ops *t, | |
4703 | linux_nat_forget_process_ftype *fn) | |
4704 | { | |
4705 | /* Save the pointer. */ | |
4706 | linux_nat_forget_process_hook = fn; | |
4707 | } | |
4708 | ||
4709 | /* See declaration in linux-nat.h. */ | |
4710 | ||
4711 | void | |
4712 | linux_nat_forget_process (pid_t pid) | |
4713 | { | |
4714 | if (linux_nat_forget_process_hook != NULL) | |
4715 | linux_nat_forget_process_hook (pid); | |
4716 | } | |
4717 | ||
5b009018 PA |
4718 | /* Register a method that converts a siginfo object between the layout |
4719 | that ptrace returns, and the layout in the architecture of the | |
4720 | inferior. */ | |
4721 | void | |
4722 | linux_nat_set_siginfo_fixup (struct target_ops *t, | |
a5362b9a | 4723 | int (*siginfo_fixup) (siginfo_t *, |
5b009018 PA |
4724 | gdb_byte *, |
4725 | int)) | |
4726 | { | |
4727 | /* Save the pointer. */ | |
4728 | linux_nat_siginfo_fixup = siginfo_fixup; | |
4729 | } | |
4730 | ||
7b50312a PA |
4731 | /* Register a method to call prior to resuming a thread. */ |
4732 | ||
4733 | void | |
4734 | linux_nat_set_prepare_to_resume (struct target_ops *t, | |
4735 | void (*prepare_to_resume) (struct lwp_info *)) | |
4736 | { | |
4737 | /* Save the pointer. */ | |
4738 | linux_nat_prepare_to_resume = prepare_to_resume; | |
4739 | } | |
4740 | ||
f865ee35 JK |
4741 | /* See linux-nat.h. */ |
4742 | ||
4743 | int | |
4744 | linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo) | |
9f0bdab8 | 4745 | { |
da559b09 | 4746 | int pid; |
9f0bdab8 | 4747 | |
dfd4cc63 | 4748 | pid = ptid_get_lwp (ptid); |
da559b09 | 4749 | if (pid == 0) |
dfd4cc63 | 4750 | pid = ptid_get_pid (ptid); |
f865ee35 | 4751 | |
da559b09 JK |
4752 | errno = 0; |
4753 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo); | |
4754 | if (errno != 0) | |
4755 | { | |
4756 | memset (siginfo, 0, sizeof (*siginfo)); | |
4757 | return 0; | |
4758 | } | |
f865ee35 | 4759 | return 1; |
9f0bdab8 DJ |
4760 | } |
4761 | ||
2c0b251b PA |
4762 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
4763 | extern initialize_file_ftype _initialize_linux_nat; | |
4764 | ||
d6b0e80f AC |
4765 | void |
4766 | _initialize_linux_nat (void) | |
4767 | { | |
ccce17b0 YQ |
4768 | add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance, |
4769 | &debug_linux_nat, _("\ | |
b84876c2 PA |
4770 | Set debugging of GNU/Linux lwp module."), _("\ |
4771 | Show debugging of GNU/Linux lwp module."), _("\ | |
4772 | Enables printf debugging output."), | |
ccce17b0 YQ |
4773 | NULL, |
4774 | show_debug_linux_nat, | |
4775 | &setdebuglist, &showdebuglist); | |
b84876c2 | 4776 | |
b84876c2 | 4777 | /* Save this mask as the default. */ |
d6b0e80f AC |
4778 | sigprocmask (SIG_SETMASK, NULL, &normal_mask); |
4779 | ||
7feb7d06 PA |
4780 | /* Install a SIGCHLD handler. */ |
4781 | sigchld_action.sa_handler = sigchld_handler; | |
4782 | sigemptyset (&sigchld_action.sa_mask); | |
4783 | sigchld_action.sa_flags = SA_RESTART; | |
b84876c2 PA |
4784 | |
4785 | /* Make it the default. */ | |
7feb7d06 | 4786 | sigaction (SIGCHLD, &sigchld_action, NULL); |
d6b0e80f AC |
4787 | |
4788 | /* Make sure we don't block SIGCHLD during a sigsuspend. */ | |
4789 | sigprocmask (SIG_SETMASK, NULL, &suspend_mask); | |
4790 | sigdelset (&suspend_mask, SIGCHLD); | |
4791 | ||
7feb7d06 | 4792 | sigemptyset (&blocked_mask); |
8009206a TT |
4793 | |
4794 | /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to | |
4795 | support read-only process state. */ | |
4796 | linux_ptrace_set_additional_flags (PTRACE_O_TRACESYSGOOD | |
4797 | | PTRACE_O_TRACEVFORKDONE | |
4798 | | PTRACE_O_TRACEVFORK | |
4799 | | PTRACE_O_TRACEFORK | |
4800 | | PTRACE_O_TRACEEXEC); | |
d6b0e80f AC |
4801 | } |
4802 | \f | |
4803 | ||
4804 | /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to | |
4805 | the GNU/Linux Threads library and therefore doesn't really belong | |
4806 | here. */ | |
4807 | ||
4808 | /* Read variable NAME in the target and return its value if found. | |
4809 | Otherwise return zero. It is assumed that the type of the variable | |
4810 | is `int'. */ | |
4811 | ||
4812 | static int | |
4813 | get_signo (const char *name) | |
4814 | { | |
3b7344d5 | 4815 | struct bound_minimal_symbol ms; |
d6b0e80f AC |
4816 | int signo; |
4817 | ||
4818 | ms = lookup_minimal_symbol (name, NULL, NULL); | |
3b7344d5 | 4819 | if (ms.minsym == NULL) |
d6b0e80f AC |
4820 | return 0; |
4821 | ||
77e371c0 | 4822 | if (target_read_memory (BMSYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo, |
d6b0e80f AC |
4823 | sizeof (signo)) != 0) |
4824 | return 0; | |
4825 | ||
4826 | return signo; | |
4827 | } | |
4828 | ||
4829 | /* Return the set of signals used by the threads library in *SET. */ | |
4830 | ||
4831 | void | |
4832 | lin_thread_get_thread_signals (sigset_t *set) | |
4833 | { | |
4834 | struct sigaction action; | |
4835 | int restart, cancel; | |
4836 | ||
b84876c2 | 4837 | sigemptyset (&blocked_mask); |
d6b0e80f AC |
4838 | sigemptyset (set); |
4839 | ||
4840 | restart = get_signo ("__pthread_sig_restart"); | |
17fbb0bd DJ |
4841 | cancel = get_signo ("__pthread_sig_cancel"); |
4842 | ||
4843 | /* LinuxThreads normally uses the first two RT signals, but in some legacy | |
4844 | cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does | |
4845 | not provide any way for the debugger to query the signal numbers - | |
4846 | fortunately they don't change! */ | |
4847 | ||
d6b0e80f | 4848 | if (restart == 0) |
17fbb0bd | 4849 | restart = __SIGRTMIN; |
d6b0e80f | 4850 | |
d6b0e80f | 4851 | if (cancel == 0) |
17fbb0bd | 4852 | cancel = __SIGRTMIN + 1; |
d6b0e80f AC |
4853 | |
4854 | sigaddset (set, restart); | |
4855 | sigaddset (set, cancel); | |
4856 | ||
4857 | /* The GNU/Linux Threads library makes terminating threads send a | |
4858 | special "cancel" signal instead of SIGCHLD. Make sure we catch | |
4859 | those (to prevent them from terminating GDB itself, which is | |
4860 | likely to be their default action) and treat them the same way as | |
4861 | SIGCHLD. */ | |
4862 | ||
4863 | action.sa_handler = sigchld_handler; | |
4864 | sigemptyset (&action.sa_mask); | |
58aecb61 | 4865 | action.sa_flags = SA_RESTART; |
d6b0e80f AC |
4866 | sigaction (cancel, &action, NULL); |
4867 | ||
4868 | /* We block the "cancel" signal throughout this code ... */ | |
4869 | sigaddset (&blocked_mask, cancel); | |
4870 | sigprocmask (SIG_BLOCK, &blocked_mask, NULL); | |
4871 | ||
4872 | /* ... except during a sigsuspend. */ | |
4873 | sigdelset (&suspend_mask, cancel); | |
4874 | } |