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); | |
2db9a427 | 267 | static int resume_stopped_resumed_lwps (struct lwp_info *lp, void *data); |
7feb7d06 PA |
268 | |
269 | static void block_child_signals (sigset_t *prev_mask); | |
270 | static void restore_child_signals_mask (sigset_t *prev_mask); | |
2277426b PA |
271 | |
272 | struct lwp_info; | |
273 | static struct lwp_info *add_lwp (ptid_t ptid); | |
274 | static void purge_lwp_list (int pid); | |
4403d8e9 | 275 | static void delete_lwp (ptid_t ptid); |
2277426b PA |
276 | static struct lwp_info *find_lwp_pid (ptid_t ptid); |
277 | ||
8a99810d PA |
278 | static int lwp_status_pending_p (struct lwp_info *lp); |
279 | ||
9c02b525 PA |
280 | static int check_stopped_by_breakpoint (struct lwp_info *lp); |
281 | static int sigtrap_is_event (int status); | |
282 | static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event; | |
283 | ||
cff068da GB |
284 | \f |
285 | /* LWP accessors. */ | |
286 | ||
287 | /* See nat/linux-nat.h. */ | |
288 | ||
289 | ptid_t | |
290 | ptid_of_lwp (struct lwp_info *lwp) | |
291 | { | |
292 | return lwp->ptid; | |
293 | } | |
294 | ||
295 | /* See nat/linux-nat.h. */ | |
296 | ||
4b134ca1 GB |
297 | void |
298 | lwp_set_arch_private_info (struct lwp_info *lwp, | |
299 | struct arch_lwp_info *info) | |
300 | { | |
301 | lwp->arch_private = info; | |
302 | } | |
303 | ||
304 | /* See nat/linux-nat.h. */ | |
305 | ||
306 | struct arch_lwp_info * | |
307 | lwp_arch_private_info (struct lwp_info *lwp) | |
308 | { | |
309 | return lwp->arch_private; | |
310 | } | |
311 | ||
312 | /* See nat/linux-nat.h. */ | |
313 | ||
cff068da GB |
314 | int |
315 | lwp_is_stopped (struct lwp_info *lwp) | |
316 | { | |
317 | return lwp->stopped; | |
318 | } | |
319 | ||
320 | /* See nat/linux-nat.h. */ | |
321 | ||
322 | enum target_stop_reason | |
323 | lwp_stop_reason (struct lwp_info *lwp) | |
324 | { | |
325 | return lwp->stop_reason; | |
326 | } | |
327 | ||
ae087d01 DJ |
328 | \f |
329 | /* Trivial list manipulation functions to keep track of a list of | |
330 | new stopped processes. */ | |
331 | static void | |
3d799a95 | 332 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
ae087d01 DJ |
333 | { |
334 | struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list)); | |
e0881a8e | 335 | |
ae087d01 | 336 | new_pid->pid = pid; |
3d799a95 | 337 | new_pid->status = status; |
ae087d01 DJ |
338 | new_pid->next = *listp; |
339 | *listp = new_pid; | |
340 | } | |
341 | ||
84636d28 PA |
342 | static int |
343 | in_pid_list_p (struct simple_pid_list *list, int pid) | |
344 | { | |
345 | struct simple_pid_list *p; | |
346 | ||
347 | for (p = list; p != NULL; p = p->next) | |
348 | if (p->pid == pid) | |
349 | return 1; | |
350 | return 0; | |
351 | } | |
352 | ||
ae087d01 | 353 | static int |
46a96992 | 354 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
ae087d01 DJ |
355 | { |
356 | struct simple_pid_list **p; | |
357 | ||
358 | for (p = listp; *p != NULL; p = &(*p)->next) | |
359 | if ((*p)->pid == pid) | |
360 | { | |
361 | struct simple_pid_list *next = (*p)->next; | |
e0881a8e | 362 | |
46a96992 | 363 | *statusp = (*p)->status; |
ae087d01 DJ |
364 | xfree (*p); |
365 | *p = next; | |
366 | return 1; | |
367 | } | |
368 | return 0; | |
369 | } | |
370 | ||
96d7229d | 371 | /* Initialize ptrace warnings and check for supported ptrace |
beed38b8 JB |
372 | features given PID. |
373 | ||
374 | ATTACHED should be nonzero iff we attached to the inferior. */ | |
3993f6b1 DJ |
375 | |
376 | static void | |
beed38b8 | 377 | linux_init_ptrace (pid_t pid, int attached) |
3993f6b1 | 378 | { |
beed38b8 | 379 | linux_enable_event_reporting (pid, attached); |
96d7229d | 380 | linux_ptrace_init_warnings (); |
4de4c07c DJ |
381 | } |
382 | ||
6d8fd2b7 | 383 | static void |
f045800c | 384 | linux_child_post_attach (struct target_ops *self, int pid) |
4de4c07c | 385 | { |
beed38b8 | 386 | linux_init_ptrace (pid, 1); |
4de4c07c DJ |
387 | } |
388 | ||
10d6c8cd | 389 | static void |
2e97a79e | 390 | linux_child_post_startup_inferior (struct target_ops *self, ptid_t ptid) |
4de4c07c | 391 | { |
beed38b8 | 392 | linux_init_ptrace (ptid_get_pid (ptid), 0); |
4de4c07c DJ |
393 | } |
394 | ||
4403d8e9 JK |
395 | /* Return the number of known LWPs in the tgid given by PID. */ |
396 | ||
397 | static int | |
398 | num_lwps (int pid) | |
399 | { | |
400 | int count = 0; | |
401 | struct lwp_info *lp; | |
402 | ||
403 | for (lp = lwp_list; lp; lp = lp->next) | |
404 | if (ptid_get_pid (lp->ptid) == pid) | |
405 | count++; | |
406 | ||
407 | return count; | |
408 | } | |
409 | ||
410 | /* Call delete_lwp with prototype compatible for make_cleanup. */ | |
411 | ||
412 | static void | |
413 | delete_lwp_cleanup (void *lp_voidp) | |
414 | { | |
415 | struct lwp_info *lp = lp_voidp; | |
416 | ||
417 | delete_lwp (lp->ptid); | |
418 | } | |
419 | ||
d83ad864 DB |
420 | /* Target hook for follow_fork. On entry inferior_ptid must be the |
421 | ptid of the followed inferior. At return, inferior_ptid will be | |
422 | unchanged. */ | |
423 | ||
6d8fd2b7 | 424 | static int |
07107ca6 LM |
425 | linux_child_follow_fork (struct target_ops *ops, int follow_child, |
426 | int detach_fork) | |
3993f6b1 | 427 | { |
d83ad864 | 428 | if (!follow_child) |
4de4c07c | 429 | { |
6c95b8df | 430 | struct lwp_info *child_lp = NULL; |
d83ad864 DB |
431 | int status = W_STOPCODE (0); |
432 | struct cleanup *old_chain; | |
433 | int has_vforked; | |
79639e11 | 434 | ptid_t parent_ptid, child_ptid; |
d83ad864 DB |
435 | int parent_pid, child_pid; |
436 | ||
437 | has_vforked = (inferior_thread ()->pending_follow.kind | |
438 | == TARGET_WAITKIND_VFORKED); | |
79639e11 PA |
439 | parent_ptid = inferior_ptid; |
440 | child_ptid = inferior_thread ()->pending_follow.value.related_pid; | |
441 | parent_pid = ptid_get_lwp (parent_ptid); | |
442 | child_pid = ptid_get_lwp (child_ptid); | |
4de4c07c | 443 | |
1777feb0 | 444 | /* We're already attached to the parent, by default. */ |
d83ad864 | 445 | old_chain = save_inferior_ptid (); |
79639e11 | 446 | inferior_ptid = child_ptid; |
d83ad864 DB |
447 | child_lp = add_lwp (inferior_ptid); |
448 | child_lp->stopped = 1; | |
449 | child_lp->last_resume_kind = resume_stop; | |
4de4c07c | 450 | |
ac264b3b MS |
451 | /* Detach new forked process? */ |
452 | if (detach_fork) | |
f75c00e4 | 453 | { |
4403d8e9 JK |
454 | make_cleanup (delete_lwp_cleanup, child_lp); |
455 | ||
4403d8e9 JK |
456 | if (linux_nat_prepare_to_resume != NULL) |
457 | linux_nat_prepare_to_resume (child_lp); | |
c077881a HZ |
458 | |
459 | /* When debugging an inferior in an architecture that supports | |
460 | hardware single stepping on a kernel without commit | |
461 | 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child | |
462 | process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits | |
463 | set if the parent process had them set. | |
464 | To work around this, single step the child process | |
465 | once before detaching to clear the flags. */ | |
466 | ||
467 | if (!gdbarch_software_single_step_p (target_thread_architecture | |
468 | (child_lp->ptid))) | |
469 | { | |
c077881a HZ |
470 | linux_disable_event_reporting (child_pid); |
471 | if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0) | |
472 | perror_with_name (_("Couldn't do single step")); | |
473 | if (my_waitpid (child_pid, &status, 0) < 0) | |
474 | perror_with_name (_("Couldn't wait vfork process")); | |
475 | } | |
476 | ||
477 | if (WIFSTOPPED (status)) | |
9caaaa83 PA |
478 | { |
479 | int signo; | |
480 | ||
481 | signo = WSTOPSIG (status); | |
482 | if (signo != 0 | |
483 | && !signal_pass_state (gdb_signal_from_host (signo))) | |
484 | signo = 0; | |
485 | ptrace (PTRACE_DETACH, child_pid, 0, signo); | |
486 | } | |
4403d8e9 | 487 | |
d83ad864 | 488 | /* Resets value of inferior_ptid to parent ptid. */ |
4403d8e9 | 489 | do_cleanups (old_chain); |
ac264b3b MS |
490 | } |
491 | else | |
492 | { | |
6c95b8df | 493 | /* Let the thread_db layer learn about this new process. */ |
2277426b | 494 | check_for_thread_db (); |
ac264b3b | 495 | } |
9016a515 | 496 | |
d83ad864 DB |
497 | do_cleanups (old_chain); |
498 | ||
9016a515 DJ |
499 | if (has_vforked) |
500 | { | |
3ced3da4 | 501 | struct lwp_info *parent_lp; |
6c95b8df | 502 | |
79639e11 | 503 | parent_lp = find_lwp_pid (parent_ptid); |
96d7229d | 504 | gdb_assert (linux_supports_tracefork () >= 0); |
3ced3da4 | 505 | |
96d7229d | 506 | if (linux_supports_tracevforkdone ()) |
9016a515 | 507 | { |
6c95b8df PA |
508 | if (debug_linux_nat) |
509 | fprintf_unfiltered (gdb_stdlog, | |
510 | "LCFF: waiting for VFORK_DONE on %d\n", | |
511 | parent_pid); | |
3ced3da4 | 512 | parent_lp->stopped = 1; |
9016a515 | 513 | |
6c95b8df PA |
514 | /* We'll handle the VFORK_DONE event like any other |
515 | event, in target_wait. */ | |
9016a515 DJ |
516 | } |
517 | else | |
518 | { | |
519 | /* We can't insert breakpoints until the child has | |
520 | finished with the shared memory region. We need to | |
521 | wait until that happens. Ideal would be to just | |
522 | call: | |
523 | - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0); | |
524 | - waitpid (parent_pid, &status, __WALL); | |
525 | However, most architectures can't handle a syscall | |
526 | being traced on the way out if it wasn't traced on | |
527 | the way in. | |
528 | ||
529 | We might also think to loop, continuing the child | |
530 | until it exits or gets a SIGTRAP. One problem is | |
531 | that the child might call ptrace with PTRACE_TRACEME. | |
532 | ||
533 | There's no simple and reliable way to figure out when | |
534 | the vforked child will be done with its copy of the | |
535 | shared memory. We could step it out of the syscall, | |
536 | two instructions, let it go, and then single-step the | |
537 | parent once. When we have hardware single-step, this | |
538 | would work; with software single-step it could still | |
539 | be made to work but we'd have to be able to insert | |
540 | single-step breakpoints in the child, and we'd have | |
541 | to insert -just- the single-step breakpoint in the | |
542 | parent. Very awkward. | |
543 | ||
544 | In the end, the best we can do is to make sure it | |
545 | runs for a little while. Hopefully it will be out of | |
546 | range of any breakpoints we reinsert. Usually this | |
547 | is only the single-step breakpoint at vfork's return | |
548 | point. */ | |
549 | ||
6c95b8df PA |
550 | if (debug_linux_nat) |
551 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
552 | "LCFF: no VFORK_DONE " |
553 | "support, sleeping a bit\n"); | |
6c95b8df | 554 | |
9016a515 | 555 | usleep (10000); |
9016a515 | 556 | |
6c95b8df PA |
557 | /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event, |
558 | and leave it pending. The next linux_nat_resume call | |
559 | will notice a pending event, and bypasses actually | |
560 | resuming the inferior. */ | |
3ced3da4 PA |
561 | parent_lp->status = 0; |
562 | parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE; | |
563 | parent_lp->stopped = 1; | |
6c95b8df PA |
564 | |
565 | /* If we're in async mode, need to tell the event loop | |
566 | there's something here to process. */ | |
d9d41e78 | 567 | if (target_is_async_p ()) |
6c95b8df PA |
568 | async_file_mark (); |
569 | } | |
9016a515 | 570 | } |
4de4c07c | 571 | } |
3993f6b1 | 572 | else |
4de4c07c | 573 | { |
3ced3da4 | 574 | struct lwp_info *child_lp; |
4de4c07c | 575 | |
3ced3da4 PA |
576 | child_lp = add_lwp (inferior_ptid); |
577 | child_lp->stopped = 1; | |
25289eb2 | 578 | child_lp->last_resume_kind = resume_stop; |
6c95b8df | 579 | |
6c95b8df | 580 | /* Let the thread_db layer learn about this new process. */ |
ef29ce1a | 581 | check_for_thread_db (); |
4de4c07c DJ |
582 | } |
583 | ||
584 | return 0; | |
585 | } | |
586 | ||
4de4c07c | 587 | \f |
77b06cd7 | 588 | static int |
a863b201 | 589 | linux_child_insert_fork_catchpoint (struct target_ops *self, int pid) |
4de4c07c | 590 | { |
96d7229d | 591 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
592 | } |
593 | ||
eb73ad13 | 594 | static int |
973fc227 | 595 | linux_child_remove_fork_catchpoint (struct target_ops *self, int pid) |
eb73ad13 PA |
596 | { |
597 | return 0; | |
598 | } | |
599 | ||
77b06cd7 | 600 | static int |
3ecc7da0 | 601 | linux_child_insert_vfork_catchpoint (struct target_ops *self, int pid) |
3993f6b1 | 602 | { |
96d7229d | 603 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
604 | } |
605 | ||
eb73ad13 | 606 | static int |
e98cf0cd | 607 | linux_child_remove_vfork_catchpoint (struct target_ops *self, int pid) |
eb73ad13 PA |
608 | { |
609 | return 0; | |
610 | } | |
611 | ||
77b06cd7 | 612 | static int |
ba025e51 | 613 | linux_child_insert_exec_catchpoint (struct target_ops *self, int pid) |
3993f6b1 | 614 | { |
96d7229d | 615 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
616 | } |
617 | ||
eb73ad13 | 618 | static int |
758e29d2 | 619 | linux_child_remove_exec_catchpoint (struct target_ops *self, int pid) |
eb73ad13 PA |
620 | { |
621 | return 0; | |
622 | } | |
623 | ||
a96d9b2e | 624 | static int |
ff214e67 TT |
625 | linux_child_set_syscall_catchpoint (struct target_ops *self, |
626 | int pid, int needed, int any_count, | |
a96d9b2e SDJ |
627 | int table_size, int *table) |
628 | { | |
96d7229d | 629 | if (!linux_supports_tracesysgood ()) |
77b06cd7 TJB |
630 | return 1; |
631 | ||
a96d9b2e SDJ |
632 | /* On GNU/Linux, we ignore the arguments. It means that we only |
633 | enable the syscall catchpoints, but do not disable them. | |
77b06cd7 | 634 | |
a96d9b2e SDJ |
635 | Also, we do not use the `table' information because we do not |
636 | filter system calls here. We let GDB do the logic for us. */ | |
637 | return 0; | |
638 | } | |
639 | ||
d6b0e80f AC |
640 | /* On GNU/Linux there are no real LWP's. The closest thing to LWP's |
641 | are processes sharing the same VM space. A multi-threaded process | |
642 | is basically a group of such processes. However, such a grouping | |
643 | is almost entirely a user-space issue; the kernel doesn't enforce | |
644 | such a grouping at all (this might change in the future). In | |
645 | general, we'll rely on the threads library (i.e. the GNU/Linux | |
646 | Threads library) to provide such a grouping. | |
647 | ||
648 | It is perfectly well possible to write a multi-threaded application | |
649 | without the assistance of a threads library, by using the clone | |
650 | system call directly. This module should be able to give some | |
651 | rudimentary support for debugging such applications if developers | |
652 | specify the CLONE_PTRACE flag in the clone system call, and are | |
653 | using the Linux kernel 2.4 or above. | |
654 | ||
655 | Note that there are some peculiarities in GNU/Linux that affect | |
656 | this code: | |
657 | ||
658 | - In general one should specify the __WCLONE flag to waitpid in | |
659 | order to make it report events for any of the cloned processes | |
660 | (and leave it out for the initial process). However, if a cloned | |
661 | process has exited the exit status is only reported if the | |
662 | __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but | |
663 | we cannot use it since GDB must work on older systems too. | |
664 | ||
665 | - When a traced, cloned process exits and is waited for by the | |
666 | debugger, the kernel reassigns it to the original parent and | |
667 | keeps it around as a "zombie". Somehow, the GNU/Linux Threads | |
668 | library doesn't notice this, which leads to the "zombie problem": | |
669 | When debugged a multi-threaded process that spawns a lot of | |
670 | threads will run out of processes, even if the threads exit, | |
671 | because the "zombies" stay around. */ | |
672 | ||
673 | /* List of known LWPs. */ | |
9f0bdab8 | 674 | struct lwp_info *lwp_list; |
d6b0e80f AC |
675 | \f |
676 | ||
d6b0e80f AC |
677 | /* Original signal mask. */ |
678 | static sigset_t normal_mask; | |
679 | ||
680 | /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in | |
681 | _initialize_linux_nat. */ | |
682 | static sigset_t suspend_mask; | |
683 | ||
7feb7d06 PA |
684 | /* Signals to block to make that sigsuspend work. */ |
685 | static sigset_t blocked_mask; | |
686 | ||
687 | /* SIGCHLD action. */ | |
688 | struct sigaction sigchld_action; | |
b84876c2 | 689 | |
7feb7d06 PA |
690 | /* Block child signals (SIGCHLD and linux threads signals), and store |
691 | the previous mask in PREV_MASK. */ | |
84e46146 | 692 | |
7feb7d06 PA |
693 | static void |
694 | block_child_signals (sigset_t *prev_mask) | |
695 | { | |
696 | /* Make sure SIGCHLD is blocked. */ | |
697 | if (!sigismember (&blocked_mask, SIGCHLD)) | |
698 | sigaddset (&blocked_mask, SIGCHLD); | |
699 | ||
700 | sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask); | |
701 | } | |
702 | ||
703 | /* Restore child signals mask, previously returned by | |
704 | block_child_signals. */ | |
705 | ||
706 | static void | |
707 | restore_child_signals_mask (sigset_t *prev_mask) | |
708 | { | |
709 | sigprocmask (SIG_SETMASK, prev_mask, NULL); | |
710 | } | |
2455069d UW |
711 | |
712 | /* Mask of signals to pass directly to the inferior. */ | |
713 | static sigset_t pass_mask; | |
714 | ||
715 | /* Update signals to pass to the inferior. */ | |
716 | static void | |
94bedb42 TT |
717 | linux_nat_pass_signals (struct target_ops *self, |
718 | int numsigs, unsigned char *pass_signals) | |
2455069d UW |
719 | { |
720 | int signo; | |
721 | ||
722 | sigemptyset (&pass_mask); | |
723 | ||
724 | for (signo = 1; signo < NSIG; signo++) | |
725 | { | |
2ea28649 | 726 | int target_signo = gdb_signal_from_host (signo); |
2455069d UW |
727 | if (target_signo < numsigs && pass_signals[target_signo]) |
728 | sigaddset (&pass_mask, signo); | |
729 | } | |
730 | } | |
731 | ||
d6b0e80f AC |
732 | \f |
733 | ||
734 | /* Prototypes for local functions. */ | |
735 | static int stop_wait_callback (struct lwp_info *lp, void *data); | |
28439f5e | 736 | static int linux_thread_alive (ptid_t ptid); |
8dd27370 | 737 | static char *linux_child_pid_to_exec_file (struct target_ops *self, int pid); |
20ba1ce6 | 738 | static int resume_stopped_resumed_lwps (struct lwp_info *lp, void *data); |
710151dd | 739 | |
d6b0e80f | 740 | \f |
d6b0e80f | 741 | |
7b50312a PA |
742 | /* Destroy and free LP. */ |
743 | ||
744 | static void | |
745 | lwp_free (struct lwp_info *lp) | |
746 | { | |
747 | xfree (lp->arch_private); | |
748 | xfree (lp); | |
749 | } | |
750 | ||
d90e17a7 PA |
751 | /* Remove all LWPs belong to PID from the lwp list. */ |
752 | ||
753 | static void | |
754 | purge_lwp_list (int pid) | |
755 | { | |
756 | struct lwp_info *lp, *lpprev, *lpnext; | |
757 | ||
758 | lpprev = NULL; | |
759 | ||
760 | for (lp = lwp_list; lp; lp = lpnext) | |
761 | { | |
762 | lpnext = lp->next; | |
763 | ||
764 | if (ptid_get_pid (lp->ptid) == pid) | |
765 | { | |
766 | if (lp == lwp_list) | |
767 | lwp_list = lp->next; | |
768 | else | |
769 | lpprev->next = lp->next; | |
770 | ||
7b50312a | 771 | lwp_free (lp); |
d90e17a7 PA |
772 | } |
773 | else | |
774 | lpprev = lp; | |
775 | } | |
776 | } | |
777 | ||
26cb8b7c PA |
778 | /* Add the LWP specified by PTID to the list. PTID is the first LWP |
779 | in the process. Return a pointer to the structure describing the | |
780 | new LWP. | |
781 | ||
782 | This differs from add_lwp in that we don't let the arch specific | |
783 | bits know about this new thread. Current clients of this callback | |
784 | take the opportunity to install watchpoints in the new thread, and | |
785 | we shouldn't do that for the first thread. If we're spawning a | |
786 | child ("run"), the thread executes the shell wrapper first, and we | |
787 | shouldn't touch it until it execs the program we want to debug. | |
788 | For "attach", it'd be okay to call the callback, but it's not | |
789 | necessary, because watchpoints can't yet have been inserted into | |
790 | the inferior. */ | |
d6b0e80f AC |
791 | |
792 | static struct lwp_info * | |
26cb8b7c | 793 | add_initial_lwp (ptid_t ptid) |
d6b0e80f AC |
794 | { |
795 | struct lwp_info *lp; | |
796 | ||
dfd4cc63 | 797 | gdb_assert (ptid_lwp_p (ptid)); |
d6b0e80f AC |
798 | |
799 | lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info)); | |
800 | ||
801 | memset (lp, 0, sizeof (struct lwp_info)); | |
802 | ||
25289eb2 | 803 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
804 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
805 | ||
806 | lp->ptid = ptid; | |
dc146f7c | 807 | lp->core = -1; |
d6b0e80f AC |
808 | |
809 | lp->next = lwp_list; | |
810 | lwp_list = lp; | |
d6b0e80f | 811 | |
26cb8b7c PA |
812 | return lp; |
813 | } | |
814 | ||
815 | /* Add the LWP specified by PID to the list. Return a pointer to the | |
816 | structure describing the new LWP. The LWP should already be | |
817 | stopped. */ | |
818 | ||
819 | static struct lwp_info * | |
820 | add_lwp (ptid_t ptid) | |
821 | { | |
822 | struct lwp_info *lp; | |
823 | ||
824 | lp = add_initial_lwp (ptid); | |
825 | ||
6e012a6c PA |
826 | /* Let the arch specific bits know about this new thread. Current |
827 | clients of this callback take the opportunity to install | |
26cb8b7c PA |
828 | watchpoints in the new thread. We don't do this for the first |
829 | thread though. See add_initial_lwp. */ | |
830 | if (linux_nat_new_thread != NULL) | |
7b50312a | 831 | linux_nat_new_thread (lp); |
9f0bdab8 | 832 | |
d6b0e80f AC |
833 | return lp; |
834 | } | |
835 | ||
836 | /* Remove the LWP specified by PID from the list. */ | |
837 | ||
838 | static void | |
839 | delete_lwp (ptid_t ptid) | |
840 | { | |
841 | struct lwp_info *lp, *lpprev; | |
842 | ||
843 | lpprev = NULL; | |
844 | ||
845 | for (lp = lwp_list; lp; lpprev = lp, lp = lp->next) | |
846 | if (ptid_equal (lp->ptid, ptid)) | |
847 | break; | |
848 | ||
849 | if (!lp) | |
850 | return; | |
851 | ||
d6b0e80f AC |
852 | if (lpprev) |
853 | lpprev->next = lp->next; | |
854 | else | |
855 | lwp_list = lp->next; | |
856 | ||
7b50312a | 857 | lwp_free (lp); |
d6b0e80f AC |
858 | } |
859 | ||
860 | /* Return a pointer to the structure describing the LWP corresponding | |
861 | to PID. If no corresponding LWP could be found, return NULL. */ | |
862 | ||
863 | static struct lwp_info * | |
864 | find_lwp_pid (ptid_t ptid) | |
865 | { | |
866 | struct lwp_info *lp; | |
867 | int lwp; | |
868 | ||
dfd4cc63 LM |
869 | if (ptid_lwp_p (ptid)) |
870 | lwp = ptid_get_lwp (ptid); | |
d6b0e80f | 871 | else |
dfd4cc63 | 872 | lwp = ptid_get_pid (ptid); |
d6b0e80f AC |
873 | |
874 | for (lp = lwp_list; lp; lp = lp->next) | |
dfd4cc63 | 875 | if (lwp == ptid_get_lwp (lp->ptid)) |
d6b0e80f AC |
876 | return lp; |
877 | ||
878 | return NULL; | |
879 | } | |
880 | ||
6d4ee8c6 | 881 | /* See nat/linux-nat.h. */ |
d6b0e80f AC |
882 | |
883 | struct lwp_info * | |
d90e17a7 | 884 | iterate_over_lwps (ptid_t filter, |
6d4ee8c6 | 885 | iterate_over_lwps_ftype callback, |
d90e17a7 | 886 | void *data) |
d6b0e80f AC |
887 | { |
888 | struct lwp_info *lp, *lpnext; | |
889 | ||
890 | for (lp = lwp_list; lp; lp = lpnext) | |
891 | { | |
892 | lpnext = lp->next; | |
d90e17a7 PA |
893 | |
894 | if (ptid_match (lp->ptid, filter)) | |
895 | { | |
6d4ee8c6 | 896 | if ((*callback) (lp, data) != 0) |
d90e17a7 PA |
897 | return lp; |
898 | } | |
d6b0e80f AC |
899 | } |
900 | ||
901 | return NULL; | |
902 | } | |
903 | ||
2277426b PA |
904 | /* Update our internal state when changing from one checkpoint to |
905 | another indicated by NEW_PTID. We can only switch single-threaded | |
906 | applications, so we only create one new LWP, and the previous list | |
907 | is discarded. */ | |
f973ed9c DJ |
908 | |
909 | void | |
910 | linux_nat_switch_fork (ptid_t new_ptid) | |
911 | { | |
912 | struct lwp_info *lp; | |
913 | ||
dfd4cc63 | 914 | purge_lwp_list (ptid_get_pid (inferior_ptid)); |
2277426b | 915 | |
f973ed9c DJ |
916 | lp = add_lwp (new_ptid); |
917 | lp->stopped = 1; | |
e26af52f | 918 | |
2277426b PA |
919 | /* This changes the thread's ptid while preserving the gdb thread |
920 | num. Also changes the inferior pid, while preserving the | |
921 | inferior num. */ | |
922 | thread_change_ptid (inferior_ptid, new_ptid); | |
923 | ||
924 | /* We've just told GDB core that the thread changed target id, but, | |
925 | in fact, it really is a different thread, with different register | |
926 | contents. */ | |
927 | registers_changed (); | |
e26af52f DJ |
928 | } |
929 | ||
e26af52f DJ |
930 | /* Handle the exit of a single thread LP. */ |
931 | ||
932 | static void | |
933 | exit_lwp (struct lwp_info *lp) | |
934 | { | |
e09875d4 | 935 | struct thread_info *th = find_thread_ptid (lp->ptid); |
063bfe2e VP |
936 | |
937 | if (th) | |
e26af52f | 938 | { |
17faa917 DJ |
939 | if (print_thread_events) |
940 | printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid)); | |
941 | ||
4f8d22e3 | 942 | delete_thread (lp->ptid); |
e26af52f DJ |
943 | } |
944 | ||
945 | delete_lwp (lp->ptid); | |
946 | } | |
947 | ||
a0ef4274 DJ |
948 | /* Wait for the LWP specified by LP, which we have just attached to. |
949 | Returns a wait status for that LWP, to cache. */ | |
950 | ||
951 | static int | |
952 | linux_nat_post_attach_wait (ptid_t ptid, int first, int *cloned, | |
953 | int *signalled) | |
954 | { | |
dfd4cc63 | 955 | pid_t new_pid, pid = ptid_get_lwp (ptid); |
a0ef4274 DJ |
956 | int status; |
957 | ||
644cebc9 | 958 | if (linux_proc_pid_is_stopped (pid)) |
a0ef4274 DJ |
959 | { |
960 | if (debug_linux_nat) | |
961 | fprintf_unfiltered (gdb_stdlog, | |
962 | "LNPAW: Attaching to a stopped process\n"); | |
963 | ||
964 | /* The process is definitely stopped. It is in a job control | |
965 | stop, unless the kernel predates the TASK_STOPPED / | |
966 | TASK_TRACED distinction, in which case it might be in a | |
967 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
968 | can kill it, signal it, et cetera. | |
969 | ||
970 | First make sure there is a pending SIGSTOP. Since we are | |
971 | already attached, the process can not transition from stopped | |
972 | to running without a PTRACE_CONT; so we know this signal will | |
973 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
974 | probably already in the queue (unless this kernel is old | |
975 | enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP | |
976 | is not an RT signal, it can only be queued once. */ | |
977 | kill_lwp (pid, SIGSTOP); | |
978 | ||
979 | /* Finally, resume the stopped process. This will deliver the SIGSTOP | |
980 | (or a higher priority signal, just like normal PTRACE_ATTACH). */ | |
981 | ptrace (PTRACE_CONT, pid, 0, 0); | |
982 | } | |
983 | ||
984 | /* Make sure the initial process is stopped. The user-level threads | |
985 | layer might want to poke around in the inferior, and that won't | |
986 | work if things haven't stabilized yet. */ | |
987 | new_pid = my_waitpid (pid, &status, 0); | |
988 | if (new_pid == -1 && errno == ECHILD) | |
989 | { | |
990 | if (first) | |
991 | warning (_("%s is a cloned process"), target_pid_to_str (ptid)); | |
992 | ||
993 | /* Try again with __WCLONE to check cloned processes. */ | |
994 | new_pid = my_waitpid (pid, &status, __WCLONE); | |
995 | *cloned = 1; | |
996 | } | |
997 | ||
dacc9cb2 PP |
998 | gdb_assert (pid == new_pid); |
999 | ||
1000 | if (!WIFSTOPPED (status)) | |
1001 | { | |
1002 | /* The pid we tried to attach has apparently just exited. */ | |
1003 | if (debug_linux_nat) | |
1004 | fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s", | |
1005 | pid, status_to_str (status)); | |
1006 | return status; | |
1007 | } | |
a0ef4274 DJ |
1008 | |
1009 | if (WSTOPSIG (status) != SIGSTOP) | |
1010 | { | |
1011 | *signalled = 1; | |
1012 | if (debug_linux_nat) | |
1013 | fprintf_unfiltered (gdb_stdlog, | |
1014 | "LNPAW: Received %s after attaching\n", | |
1015 | status_to_str (status)); | |
1016 | } | |
1017 | ||
1018 | return status; | |
1019 | } | |
1020 | ||
84636d28 PA |
1021 | /* Attach to the LWP specified by PID. Return 0 if successful, -1 if |
1022 | the new LWP could not be attached, or 1 if we're already auto | |
1023 | attached to this thread, but haven't processed the | |
1024 | PTRACE_EVENT_CLONE event of its parent thread, so we just ignore | |
1025 | its existance, without considering it an error. */ | |
d6b0e80f | 1026 | |
9ee57c33 | 1027 | int |
93815fbf | 1028 | lin_lwp_attach_lwp (ptid_t ptid) |
d6b0e80f | 1029 | { |
9ee57c33 | 1030 | struct lwp_info *lp; |
84636d28 | 1031 | int lwpid; |
d6b0e80f | 1032 | |
dfd4cc63 | 1033 | gdb_assert (ptid_lwp_p (ptid)); |
d6b0e80f | 1034 | |
9ee57c33 | 1035 | lp = find_lwp_pid (ptid); |
dfd4cc63 | 1036 | lwpid = ptid_get_lwp (ptid); |
d6b0e80f | 1037 | |
3b27ef47 | 1038 | /* We assume that we're already attached to any LWP that is already |
d6b0e80f AC |
1039 | in our list of LWPs. If we're not seeing exit events from threads |
1040 | and we've had PID wraparound since we last tried to stop all threads, | |
1041 | this assumption might be wrong; fortunately, this is very unlikely | |
1042 | to happen. */ | |
3b27ef47 | 1043 | if (lp == NULL) |
d6b0e80f | 1044 | { |
a0ef4274 | 1045 | int status, cloned = 0, signalled = 0; |
d6b0e80f | 1046 | |
84636d28 | 1047 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) |
9ee57c33 | 1048 | { |
96d7229d | 1049 | if (linux_supports_tracefork ()) |
84636d28 PA |
1050 | { |
1051 | /* If we haven't stopped all threads when we get here, | |
1052 | we may have seen a thread listed in thread_db's list, | |
1053 | but not processed the PTRACE_EVENT_CLONE yet. If | |
1054 | that's the case, ignore this new thread, and let | |
1055 | normal event handling discover it later. */ | |
1056 | if (in_pid_list_p (stopped_pids, lwpid)) | |
1057 | { | |
1058 | /* We've already seen this thread stop, but we | |
1059 | haven't seen the PTRACE_EVENT_CLONE extended | |
1060 | event yet. */ | |
3b27ef47 PA |
1061 | if (debug_linux_nat) |
1062 | fprintf_unfiltered (gdb_stdlog, | |
1063 | "LLAL: attach failed, but already seen " | |
1064 | "this thread %s stop\n", | |
1065 | target_pid_to_str (ptid)); | |
1066 | return 1; | |
84636d28 PA |
1067 | } |
1068 | else | |
1069 | { | |
1070 | int new_pid; | |
1071 | int status; | |
1072 | ||
3b27ef47 PA |
1073 | if (debug_linux_nat) |
1074 | fprintf_unfiltered (gdb_stdlog, | |
1075 | "LLAL: attach failed, and haven't seen " | |
1076 | "this thread %s stop yet\n", | |
1077 | target_pid_to_str (ptid)); | |
1078 | ||
1079 | /* We may or may not be attached to the LWP already. | |
1080 | Try waitpid on it. If that errors, we're not | |
1081 | attached to the LWP yet. Otherwise, we're | |
1082 | already attached. */ | |
a33e3959 | 1083 | gdb_assert (lwpid > 0); |
84636d28 PA |
1084 | new_pid = my_waitpid (lwpid, &status, WNOHANG); |
1085 | if (new_pid == -1 && errno == ECHILD) | |
1086 | new_pid = my_waitpid (lwpid, &status, __WCLONE | WNOHANG); | |
1087 | if (new_pid != -1) | |
1088 | { | |
3b27ef47 PA |
1089 | if (new_pid == 0) |
1090 | { | |
1091 | /* The child hasn't stopped for its initial | |
1092 | SIGSTOP stop yet. */ | |
1093 | if (debug_linux_nat) | |
1094 | fprintf_unfiltered (gdb_stdlog, | |
1095 | "LLAL: child hasn't " | |
1096 | "stopped yet\n"); | |
1097 | } | |
1098 | else if (WIFSTOPPED (status)) | |
1099 | { | |
1100 | if (debug_linux_nat) | |
1101 | fprintf_unfiltered (gdb_stdlog, | |
1102 | "LLAL: adding to stopped_pids\n"); | |
1103 | add_to_pid_list (&stopped_pids, lwpid, status); | |
1104 | } | |
84636d28 PA |
1105 | return 1; |
1106 | } | |
1107 | } | |
1108 | } | |
1109 | ||
9ee57c33 DJ |
1110 | /* If we fail to attach to the thread, issue a warning, |
1111 | but continue. One way this can happen is if thread | |
e9efe249 | 1112 | creation is interrupted; as of Linux kernel 2.6.19, a |
9ee57c33 DJ |
1113 | bug may place threads in the thread list and then fail |
1114 | to create them. */ | |
1115 | warning (_("Can't attach %s: %s"), target_pid_to_str (ptid), | |
1116 | safe_strerror (errno)); | |
1117 | return -1; | |
1118 | } | |
1119 | ||
d6b0e80f AC |
1120 | if (debug_linux_nat) |
1121 | fprintf_unfiltered (gdb_stdlog, | |
1122 | "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n", | |
1123 | target_pid_to_str (ptid)); | |
1124 | ||
a0ef4274 | 1125 | status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled); |
dacc9cb2 | 1126 | if (!WIFSTOPPED (status)) |
12696c10 | 1127 | return 1; |
dacc9cb2 | 1128 | |
a0ef4274 DJ |
1129 | lp = add_lwp (ptid); |
1130 | lp->stopped = 1; | |
3b27ef47 | 1131 | lp->last_resume_kind = resume_stop; |
a0ef4274 DJ |
1132 | lp->cloned = cloned; |
1133 | lp->signalled = signalled; | |
1134 | if (WSTOPSIG (status) != SIGSTOP) | |
d6b0e80f | 1135 | { |
a0ef4274 DJ |
1136 | lp->resumed = 1; |
1137 | lp->status = status; | |
d6b0e80f AC |
1138 | } |
1139 | ||
dfd4cc63 | 1140 | target_post_attach (ptid_get_lwp (lp->ptid)); |
d6b0e80f AC |
1141 | |
1142 | if (debug_linux_nat) | |
1143 | { | |
1144 | fprintf_unfiltered (gdb_stdlog, | |
1145 | "LLAL: waitpid %s received %s\n", | |
1146 | target_pid_to_str (ptid), | |
1147 | status_to_str (status)); | |
1148 | } | |
1149 | } | |
9ee57c33 | 1150 | |
9ee57c33 | 1151 | return 0; |
d6b0e80f AC |
1152 | } |
1153 | ||
b84876c2 | 1154 | static void |
136d6dae VP |
1155 | linux_nat_create_inferior (struct target_ops *ops, |
1156 | char *exec_file, char *allargs, char **env, | |
b84876c2 PA |
1157 | int from_tty) |
1158 | { | |
8cc73a39 SDJ |
1159 | struct cleanup *restore_personality |
1160 | = maybe_disable_address_space_randomization (disable_randomization); | |
b84876c2 PA |
1161 | |
1162 | /* The fork_child mechanism is synchronous and calls target_wait, so | |
1163 | we have to mask the async mode. */ | |
1164 | ||
2455069d | 1165 | /* Make sure we report all signals during startup. */ |
94bedb42 | 1166 | linux_nat_pass_signals (ops, 0, NULL); |
2455069d | 1167 | |
136d6dae | 1168 | linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty); |
b84876c2 | 1169 | |
8cc73a39 | 1170 | do_cleanups (restore_personality); |
b84876c2 PA |
1171 | } |
1172 | ||
8784d563 PA |
1173 | /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not |
1174 | already attached. Returns true if a new LWP is found, false | |
1175 | otherwise. */ | |
1176 | ||
1177 | static int | |
1178 | attach_proc_task_lwp_callback (ptid_t ptid) | |
1179 | { | |
1180 | struct lwp_info *lp; | |
1181 | ||
1182 | /* Ignore LWPs we're already attached to. */ | |
1183 | lp = find_lwp_pid (ptid); | |
1184 | if (lp == NULL) | |
1185 | { | |
1186 | int lwpid = ptid_get_lwp (ptid); | |
1187 | ||
1188 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) | |
1189 | { | |
1190 | int err = errno; | |
1191 | ||
1192 | /* Be quiet if we simply raced with the thread exiting. | |
1193 | EPERM is returned if the thread's task still exists, and | |
1194 | is marked as exited or zombie, as well as other | |
1195 | conditions, so in that case, confirm the status in | |
1196 | /proc/PID/status. */ | |
1197 | if (err == ESRCH | |
1198 | || (err == EPERM && linux_proc_pid_is_gone (lwpid))) | |
1199 | { | |
1200 | if (debug_linux_nat) | |
1201 | { | |
1202 | fprintf_unfiltered (gdb_stdlog, | |
1203 | "Cannot attach to lwp %d: " | |
1204 | "thread is gone (%d: %s)\n", | |
1205 | lwpid, err, safe_strerror (err)); | |
1206 | } | |
1207 | } | |
1208 | else | |
1209 | { | |
f71f0b0d | 1210 | warning (_("Cannot attach to lwp %d: %s"), |
8784d563 PA |
1211 | lwpid, |
1212 | linux_ptrace_attach_fail_reason_string (ptid, | |
1213 | err)); | |
1214 | } | |
1215 | } | |
1216 | else | |
1217 | { | |
1218 | if (debug_linux_nat) | |
1219 | fprintf_unfiltered (gdb_stdlog, | |
1220 | "PTRACE_ATTACH %s, 0, 0 (OK)\n", | |
1221 | target_pid_to_str (ptid)); | |
1222 | ||
1223 | lp = add_lwp (ptid); | |
1224 | lp->cloned = 1; | |
1225 | ||
1226 | /* The next time we wait for this LWP we'll see a SIGSTOP as | |
1227 | PTRACE_ATTACH brings it to a halt. */ | |
1228 | lp->signalled = 1; | |
1229 | ||
1230 | /* We need to wait for a stop before being able to make the | |
1231 | next ptrace call on this LWP. */ | |
1232 | lp->must_set_ptrace_flags = 1; | |
1233 | } | |
1234 | ||
1235 | return 1; | |
1236 | } | |
1237 | return 0; | |
1238 | } | |
1239 | ||
d6b0e80f | 1240 | static void |
c0939df1 | 1241 | linux_nat_attach (struct target_ops *ops, const char *args, int from_tty) |
d6b0e80f AC |
1242 | { |
1243 | struct lwp_info *lp; | |
d6b0e80f | 1244 | int status; |
af990527 | 1245 | ptid_t ptid; |
d6b0e80f | 1246 | |
2455069d | 1247 | /* Make sure we report all signals during attach. */ |
94bedb42 | 1248 | linux_nat_pass_signals (ops, 0, NULL); |
2455069d | 1249 | |
492d29ea | 1250 | TRY |
87b0bb13 JK |
1251 | { |
1252 | linux_ops->to_attach (ops, args, from_tty); | |
1253 | } | |
492d29ea | 1254 | CATCH (ex, RETURN_MASK_ERROR) |
87b0bb13 JK |
1255 | { |
1256 | pid_t pid = parse_pid_to_attach (args); | |
1257 | struct buffer buffer; | |
1258 | char *message, *buffer_s; | |
1259 | ||
1260 | message = xstrdup (ex.message); | |
1261 | make_cleanup (xfree, message); | |
1262 | ||
1263 | buffer_init (&buffer); | |
7ae1a6a6 | 1264 | linux_ptrace_attach_fail_reason (pid, &buffer); |
87b0bb13 JK |
1265 | |
1266 | buffer_grow_str0 (&buffer, ""); | |
1267 | buffer_s = buffer_finish (&buffer); | |
1268 | make_cleanup (xfree, buffer_s); | |
1269 | ||
7ae1a6a6 PA |
1270 | if (*buffer_s != '\0') |
1271 | throw_error (ex.error, "warning: %s\n%s", buffer_s, message); | |
1272 | else | |
1273 | throw_error (ex.error, "%s", message); | |
87b0bb13 | 1274 | } |
492d29ea | 1275 | END_CATCH |
d6b0e80f | 1276 | |
af990527 PA |
1277 | /* The ptrace base target adds the main thread with (pid,0,0) |
1278 | format. Decorate it with lwp info. */ | |
dfd4cc63 LM |
1279 | ptid = ptid_build (ptid_get_pid (inferior_ptid), |
1280 | ptid_get_pid (inferior_ptid), | |
1281 | 0); | |
af990527 PA |
1282 | thread_change_ptid (inferior_ptid, ptid); |
1283 | ||
9f0bdab8 | 1284 | /* Add the initial process as the first LWP to the list. */ |
26cb8b7c | 1285 | lp = add_initial_lwp (ptid); |
a0ef4274 DJ |
1286 | |
1287 | status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->cloned, | |
1288 | &lp->signalled); | |
dacc9cb2 PP |
1289 | if (!WIFSTOPPED (status)) |
1290 | { | |
1291 | if (WIFEXITED (status)) | |
1292 | { | |
1293 | int exit_code = WEXITSTATUS (status); | |
1294 | ||
1295 | target_terminal_ours (); | |
1296 | target_mourn_inferior (); | |
1297 | if (exit_code == 0) | |
1298 | error (_("Unable to attach: program exited normally.")); | |
1299 | else | |
1300 | error (_("Unable to attach: program exited with code %d."), | |
1301 | exit_code); | |
1302 | } | |
1303 | else if (WIFSIGNALED (status)) | |
1304 | { | |
2ea28649 | 1305 | enum gdb_signal signo; |
dacc9cb2 PP |
1306 | |
1307 | target_terminal_ours (); | |
1308 | target_mourn_inferior (); | |
1309 | ||
2ea28649 | 1310 | signo = gdb_signal_from_host (WTERMSIG (status)); |
dacc9cb2 PP |
1311 | error (_("Unable to attach: program terminated with signal " |
1312 | "%s, %s."), | |
2ea28649 PA |
1313 | gdb_signal_to_name (signo), |
1314 | gdb_signal_to_string (signo)); | |
dacc9cb2 PP |
1315 | } |
1316 | ||
1317 | internal_error (__FILE__, __LINE__, | |
1318 | _("unexpected status %d for PID %ld"), | |
dfd4cc63 | 1319 | status, (long) ptid_get_lwp (ptid)); |
dacc9cb2 PP |
1320 | } |
1321 | ||
a0ef4274 | 1322 | lp->stopped = 1; |
9f0bdab8 | 1323 | |
a0ef4274 | 1324 | /* Save the wait status to report later. */ |
d6b0e80f | 1325 | lp->resumed = 1; |
a0ef4274 DJ |
1326 | if (debug_linux_nat) |
1327 | fprintf_unfiltered (gdb_stdlog, | |
1328 | "LNA: waitpid %ld, saving status %s\n", | |
dfd4cc63 | 1329 | (long) ptid_get_pid (lp->ptid), status_to_str (status)); |
710151dd | 1330 | |
7feb7d06 PA |
1331 | lp->status = status; |
1332 | ||
8784d563 PA |
1333 | /* We must attach to every LWP. If /proc is mounted, use that to |
1334 | find them now. The inferior may be using raw clone instead of | |
1335 | using pthreads. But even if it is using pthreads, thread_db | |
1336 | walks structures in the inferior's address space to find the list | |
1337 | of threads/LWPs, and those structures may well be corrupted. | |
1338 | Note that once thread_db is loaded, we'll still use it to list | |
1339 | threads and associate pthread info with each LWP. */ | |
1340 | linux_proc_attach_tgid_threads (ptid_get_pid (lp->ptid), | |
1341 | attach_proc_task_lwp_callback); | |
1342 | ||
7feb7d06 PA |
1343 | if (target_can_async_p ()) |
1344 | target_async (inferior_event_handler, 0); | |
d6b0e80f AC |
1345 | } |
1346 | ||
a0ef4274 DJ |
1347 | /* Get pending status of LP. */ |
1348 | static int | |
1349 | get_pending_status (struct lwp_info *lp, int *status) | |
1350 | { | |
a493e3e2 | 1351 | enum gdb_signal signo = GDB_SIGNAL_0; |
ca2163eb PA |
1352 | |
1353 | /* If we paused threads momentarily, we may have stored pending | |
1354 | events in lp->status or lp->waitstatus (see stop_wait_callback), | |
1355 | and GDB core hasn't seen any signal for those threads. | |
1356 | Otherwise, the last signal reported to the core is found in the | |
1357 | thread object's stop_signal. | |
1358 | ||
1359 | There's a corner case that isn't handled here at present. Only | |
1360 | if the thread stopped with a TARGET_WAITKIND_STOPPED does | |
1361 | stop_signal make sense as a real signal to pass to the inferior. | |
1362 | Some catchpoint related events, like | |
1363 | TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set | |
a493e3e2 | 1364 | to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But, |
ca2163eb PA |
1365 | those traps are debug API (ptrace in our case) related and |
1366 | induced; the inferior wouldn't see them if it wasn't being | |
1367 | traced. Hence, we should never pass them to the inferior, even | |
1368 | when set to pass state. Since this corner case isn't handled by | |
1369 | infrun.c when proceeding with a signal, for consistency, neither | |
1370 | do we handle it here (or elsewhere in the file we check for | |
1371 | signal pass state). Normally SIGTRAP isn't set to pass state, so | |
1372 | this is really a corner case. */ | |
1373 | ||
1374 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
a493e3e2 | 1375 | signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */ |
ca2163eb | 1376 | else if (lp->status) |
2ea28649 | 1377 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
ca2163eb PA |
1378 | else if (non_stop && !is_executing (lp->ptid)) |
1379 | { | |
1380 | struct thread_info *tp = find_thread_ptid (lp->ptid); | |
e0881a8e | 1381 | |
16c381f0 | 1382 | signo = tp->suspend.stop_signal; |
ca2163eb PA |
1383 | } |
1384 | else if (!non_stop) | |
a0ef4274 | 1385 | { |
ca2163eb PA |
1386 | struct target_waitstatus last; |
1387 | ptid_t last_ptid; | |
4c28f408 | 1388 | |
ca2163eb | 1389 | get_last_target_status (&last_ptid, &last); |
4c28f408 | 1390 | |
dfd4cc63 | 1391 | if (ptid_get_lwp (lp->ptid) == ptid_get_lwp (last_ptid)) |
ca2163eb | 1392 | { |
e09875d4 | 1393 | struct thread_info *tp = find_thread_ptid (lp->ptid); |
e0881a8e | 1394 | |
16c381f0 | 1395 | signo = tp->suspend.stop_signal; |
4c28f408 | 1396 | } |
ca2163eb | 1397 | } |
4c28f408 | 1398 | |
ca2163eb | 1399 | *status = 0; |
4c28f408 | 1400 | |
a493e3e2 | 1401 | if (signo == GDB_SIGNAL_0) |
ca2163eb PA |
1402 | { |
1403 | if (debug_linux_nat) | |
1404 | fprintf_unfiltered (gdb_stdlog, | |
1405 | "GPT: lwp %s has no pending signal\n", | |
1406 | target_pid_to_str (lp->ptid)); | |
1407 | } | |
1408 | else if (!signal_pass_state (signo)) | |
1409 | { | |
1410 | if (debug_linux_nat) | |
3e43a32a MS |
1411 | fprintf_unfiltered (gdb_stdlog, |
1412 | "GPT: lwp %s had signal %s, " | |
1413 | "but it is in no pass state\n", | |
ca2163eb | 1414 | target_pid_to_str (lp->ptid), |
2ea28649 | 1415 | gdb_signal_to_string (signo)); |
a0ef4274 | 1416 | } |
a0ef4274 | 1417 | else |
4c28f408 | 1418 | { |
2ea28649 | 1419 | *status = W_STOPCODE (gdb_signal_to_host (signo)); |
ca2163eb PA |
1420 | |
1421 | if (debug_linux_nat) | |
1422 | fprintf_unfiltered (gdb_stdlog, | |
1423 | "GPT: lwp %s has pending signal %s\n", | |
1424 | target_pid_to_str (lp->ptid), | |
2ea28649 | 1425 | gdb_signal_to_string (signo)); |
4c28f408 | 1426 | } |
a0ef4274 DJ |
1427 | |
1428 | return 0; | |
1429 | } | |
1430 | ||
d6b0e80f AC |
1431 | static int |
1432 | detach_callback (struct lwp_info *lp, void *data) | |
1433 | { | |
1434 | gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status)); | |
1435 | ||
1436 | if (debug_linux_nat && lp->status) | |
1437 | fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n", | |
1438 | strsignal (WSTOPSIG (lp->status)), | |
1439 | target_pid_to_str (lp->ptid)); | |
1440 | ||
a0ef4274 DJ |
1441 | /* If there is a pending SIGSTOP, get rid of it. */ |
1442 | if (lp->signalled) | |
d6b0e80f | 1443 | { |
d6b0e80f AC |
1444 | if (debug_linux_nat) |
1445 | fprintf_unfiltered (gdb_stdlog, | |
a0ef4274 DJ |
1446 | "DC: Sending SIGCONT to %s\n", |
1447 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 1448 | |
dfd4cc63 | 1449 | kill_lwp (ptid_get_lwp (lp->ptid), SIGCONT); |
d6b0e80f | 1450 | lp->signalled = 0; |
d6b0e80f AC |
1451 | } |
1452 | ||
1453 | /* We don't actually detach from the LWP that has an id equal to the | |
1454 | overall process id just yet. */ | |
dfd4cc63 | 1455 | if (ptid_get_lwp (lp->ptid) != ptid_get_pid (lp->ptid)) |
d6b0e80f | 1456 | { |
a0ef4274 DJ |
1457 | int status = 0; |
1458 | ||
1459 | /* Pass on any pending signal for this LWP. */ | |
1460 | get_pending_status (lp, &status); | |
1461 | ||
7b50312a PA |
1462 | if (linux_nat_prepare_to_resume != NULL) |
1463 | linux_nat_prepare_to_resume (lp); | |
d6b0e80f | 1464 | errno = 0; |
dfd4cc63 | 1465 | if (ptrace (PTRACE_DETACH, ptid_get_lwp (lp->ptid), 0, |
a0ef4274 | 1466 | WSTOPSIG (status)) < 0) |
8a3fe4f8 | 1467 | error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid), |
d6b0e80f AC |
1468 | safe_strerror (errno)); |
1469 | ||
1470 | if (debug_linux_nat) | |
1471 | fprintf_unfiltered (gdb_stdlog, | |
1472 | "PTRACE_DETACH (%s, %s, 0) (OK)\n", | |
1473 | target_pid_to_str (lp->ptid), | |
7feb7d06 | 1474 | strsignal (WSTOPSIG (status))); |
d6b0e80f AC |
1475 | |
1476 | delete_lwp (lp->ptid); | |
1477 | } | |
1478 | ||
1479 | return 0; | |
1480 | } | |
1481 | ||
1482 | static void | |
52554a0e | 1483 | linux_nat_detach (struct target_ops *ops, const char *args, int from_tty) |
d6b0e80f | 1484 | { |
b84876c2 | 1485 | int pid; |
a0ef4274 | 1486 | int status; |
d90e17a7 PA |
1487 | struct lwp_info *main_lwp; |
1488 | ||
dfd4cc63 | 1489 | pid = ptid_get_pid (inferior_ptid); |
a0ef4274 | 1490 | |
ae5e0686 MK |
1491 | /* Don't unregister from the event loop, as there may be other |
1492 | inferiors running. */ | |
b84876c2 | 1493 | |
4c28f408 PA |
1494 | /* Stop all threads before detaching. ptrace requires that the |
1495 | thread is stopped to sucessfully detach. */ | |
d90e17a7 | 1496 | iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL); |
4c28f408 PA |
1497 | /* ... and wait until all of them have reported back that |
1498 | they're no longer running. */ | |
d90e17a7 | 1499 | iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL); |
4c28f408 | 1500 | |
d90e17a7 | 1501 | iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL); |
d6b0e80f AC |
1502 | |
1503 | /* Only the initial process should be left right now. */ | |
dfd4cc63 | 1504 | gdb_assert (num_lwps (ptid_get_pid (inferior_ptid)) == 1); |
d90e17a7 PA |
1505 | |
1506 | main_lwp = find_lwp_pid (pid_to_ptid (pid)); | |
d6b0e80f | 1507 | |
a0ef4274 DJ |
1508 | /* Pass on any pending signal for the last LWP. */ |
1509 | if ((args == NULL || *args == '\0') | |
d90e17a7 | 1510 | && get_pending_status (main_lwp, &status) != -1 |
a0ef4274 DJ |
1511 | && WIFSTOPPED (status)) |
1512 | { | |
52554a0e TT |
1513 | char *tem; |
1514 | ||
a0ef4274 DJ |
1515 | /* Put the signal number in ARGS so that inf_ptrace_detach will |
1516 | pass it along with PTRACE_DETACH. */ | |
52554a0e | 1517 | tem = alloca (8); |
cde33bf1 | 1518 | xsnprintf (tem, 8, "%d", (int) WSTOPSIG (status)); |
52554a0e | 1519 | args = tem; |
ddabfc73 TT |
1520 | if (debug_linux_nat) |
1521 | fprintf_unfiltered (gdb_stdlog, | |
1522 | "LND: Sending signal %s to %s\n", | |
1523 | args, | |
1524 | target_pid_to_str (main_lwp->ptid)); | |
a0ef4274 DJ |
1525 | } |
1526 | ||
7b50312a PA |
1527 | if (linux_nat_prepare_to_resume != NULL) |
1528 | linux_nat_prepare_to_resume (main_lwp); | |
d90e17a7 | 1529 | delete_lwp (main_lwp->ptid); |
b84876c2 | 1530 | |
7a7d3353 PA |
1531 | if (forks_exist_p ()) |
1532 | { | |
1533 | /* Multi-fork case. The current inferior_ptid is being detached | |
1534 | from, but there are other viable forks to debug. Detach from | |
1535 | the current fork, and context-switch to the first | |
1536 | available. */ | |
1537 | linux_fork_detach (args, from_tty); | |
7a7d3353 PA |
1538 | } |
1539 | else | |
1540 | linux_ops->to_detach (ops, args, from_tty); | |
d6b0e80f AC |
1541 | } |
1542 | ||
8a99810d PA |
1543 | /* Resume execution of the inferior process. If STEP is nonzero, |
1544 | single-step it. If SIGNAL is nonzero, give it that signal. */ | |
1545 | ||
1546 | static void | |
23f238d3 PA |
1547 | linux_resume_one_lwp_throw (struct lwp_info *lp, int step, |
1548 | enum gdb_signal signo) | |
8a99810d | 1549 | { |
8a99810d | 1550 | lp->step = step; |
9c02b525 PA |
1551 | |
1552 | /* stop_pc doubles as the PC the LWP had when it was last resumed. | |
1553 | We only presently need that if the LWP is stepped though (to | |
1554 | handle the case of stepping a breakpoint instruction). */ | |
1555 | if (step) | |
1556 | { | |
1557 | struct regcache *regcache = get_thread_regcache (lp->ptid); | |
1558 | ||
1559 | lp->stop_pc = regcache_read_pc (regcache); | |
1560 | } | |
1561 | else | |
1562 | lp->stop_pc = 0; | |
1563 | ||
8a99810d PA |
1564 | if (linux_nat_prepare_to_resume != NULL) |
1565 | linux_nat_prepare_to_resume (lp); | |
90ad5e1d | 1566 | linux_ops->to_resume (linux_ops, lp->ptid, step, signo); |
23f238d3 PA |
1567 | |
1568 | /* Successfully resumed. Clear state that no longer makes sense, | |
1569 | and mark the LWP as running. Must not do this before resuming | |
1570 | otherwise if that fails other code will be confused. E.g., we'd | |
1571 | later try to stop the LWP and hang forever waiting for a stop | |
1572 | status. Note that we must not throw after this is cleared, | |
1573 | otherwise handle_zombie_lwp_error would get confused. */ | |
8a99810d | 1574 | lp->stopped = 0; |
23f238d3 | 1575 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; |
8a99810d PA |
1576 | registers_changed_ptid (lp->ptid); |
1577 | } | |
1578 | ||
23f238d3 PA |
1579 | /* Called when we try to resume a stopped LWP and that errors out. If |
1580 | the LWP is no longer in ptrace-stopped state (meaning it's zombie, | |
1581 | or about to become), discard the error, clear any pending status | |
1582 | the LWP may have, and return true (we'll collect the exit status | |
1583 | soon enough). Otherwise, return false. */ | |
1584 | ||
1585 | static int | |
1586 | check_ptrace_stopped_lwp_gone (struct lwp_info *lp) | |
1587 | { | |
1588 | /* If we get an error after resuming the LWP successfully, we'd | |
1589 | confuse !T state for the LWP being gone. */ | |
1590 | gdb_assert (lp->stopped); | |
1591 | ||
1592 | /* We can't just check whether the LWP is in 'Z (Zombie)' state, | |
1593 | because even if ptrace failed with ESRCH, the tracee may be "not | |
1594 | yet fully dead", but already refusing ptrace requests. In that | |
1595 | case the tracee has 'R (Running)' state for a little bit | |
1596 | (observed in Linux 3.18). See also the note on ESRCH in the | |
1597 | ptrace(2) man page. Instead, check whether the LWP has any state | |
1598 | other than ptrace-stopped. */ | |
1599 | ||
1600 | /* Don't assume anything if /proc/PID/status can't be read. */ | |
1601 | if (linux_proc_pid_is_trace_stopped_nowarn (ptid_get_lwp (lp->ptid)) == 0) | |
1602 | { | |
1603 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; | |
1604 | lp->status = 0; | |
1605 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
1606 | return 1; | |
1607 | } | |
1608 | return 0; | |
1609 | } | |
1610 | ||
1611 | /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP | |
1612 | disappears while we try to resume it. */ | |
1613 | ||
1614 | static void | |
1615 | linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) | |
1616 | { | |
1617 | TRY | |
1618 | { | |
1619 | linux_resume_one_lwp_throw (lp, step, signo); | |
1620 | } | |
1621 | CATCH (ex, RETURN_MASK_ERROR) | |
1622 | { | |
1623 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
1624 | throw_exception (ex); | |
1625 | } | |
1626 | END_CATCH | |
1627 | } | |
1628 | ||
d6b0e80f AC |
1629 | /* Resume LP. */ |
1630 | ||
25289eb2 | 1631 | static void |
e5ef252a | 1632 | resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) |
d6b0e80f | 1633 | { |
25289eb2 | 1634 | if (lp->stopped) |
6c95b8df | 1635 | { |
c9657e70 | 1636 | struct inferior *inf = find_inferior_ptid (lp->ptid); |
25289eb2 PA |
1637 | |
1638 | if (inf->vfork_child != NULL) | |
1639 | { | |
1640 | if (debug_linux_nat) | |
1641 | fprintf_unfiltered (gdb_stdlog, | |
1642 | "RC: Not resuming %s (vfork parent)\n", | |
1643 | target_pid_to_str (lp->ptid)); | |
1644 | } | |
8a99810d | 1645 | else if (!lwp_status_pending_p (lp)) |
25289eb2 PA |
1646 | { |
1647 | if (debug_linux_nat) | |
1648 | fprintf_unfiltered (gdb_stdlog, | |
e5ef252a PA |
1649 | "RC: Resuming sibling %s, %s, %s\n", |
1650 | target_pid_to_str (lp->ptid), | |
1651 | (signo != GDB_SIGNAL_0 | |
1652 | ? strsignal (gdb_signal_to_host (signo)) | |
1653 | : "0"), | |
1654 | step ? "step" : "resume"); | |
25289eb2 | 1655 | |
8a99810d | 1656 | linux_resume_one_lwp (lp, step, signo); |
25289eb2 PA |
1657 | } |
1658 | else | |
1659 | { | |
1660 | if (debug_linux_nat) | |
1661 | fprintf_unfiltered (gdb_stdlog, | |
1662 | "RC: Not resuming sibling %s (has pending)\n", | |
1663 | target_pid_to_str (lp->ptid)); | |
1664 | } | |
6c95b8df | 1665 | } |
25289eb2 | 1666 | else |
d6b0e80f | 1667 | { |
d90e17a7 PA |
1668 | if (debug_linux_nat) |
1669 | fprintf_unfiltered (gdb_stdlog, | |
25289eb2 | 1670 | "RC: Not resuming sibling %s (not stopped)\n", |
d6b0e80f | 1671 | target_pid_to_str (lp->ptid)); |
d6b0e80f | 1672 | } |
25289eb2 | 1673 | } |
d6b0e80f | 1674 | |
8817a6f2 PA |
1675 | /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing. |
1676 | Resume LWP with the last stop signal, if it is in pass state. */ | |
e5ef252a | 1677 | |
25289eb2 | 1678 | static int |
8817a6f2 | 1679 | linux_nat_resume_callback (struct lwp_info *lp, void *except) |
25289eb2 | 1680 | { |
e5ef252a PA |
1681 | enum gdb_signal signo = GDB_SIGNAL_0; |
1682 | ||
8817a6f2 PA |
1683 | if (lp == except) |
1684 | return 0; | |
1685 | ||
e5ef252a PA |
1686 | if (lp->stopped) |
1687 | { | |
1688 | struct thread_info *thread; | |
1689 | ||
1690 | thread = find_thread_ptid (lp->ptid); | |
1691 | if (thread != NULL) | |
1692 | { | |
70509625 | 1693 | signo = thread->suspend.stop_signal; |
e5ef252a PA |
1694 | thread->suspend.stop_signal = GDB_SIGNAL_0; |
1695 | } | |
1696 | } | |
1697 | ||
1698 | resume_lwp (lp, 0, signo); | |
d6b0e80f AC |
1699 | return 0; |
1700 | } | |
1701 | ||
1702 | static int | |
1703 | resume_clear_callback (struct lwp_info *lp, void *data) | |
1704 | { | |
1705 | lp->resumed = 0; | |
25289eb2 | 1706 | lp->last_resume_kind = resume_stop; |
d6b0e80f AC |
1707 | return 0; |
1708 | } | |
1709 | ||
1710 | static int | |
1711 | resume_set_callback (struct lwp_info *lp, void *data) | |
1712 | { | |
1713 | lp->resumed = 1; | |
25289eb2 | 1714 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1715 | return 0; |
1716 | } | |
1717 | ||
1718 | static void | |
28439f5e | 1719 | linux_nat_resume (struct target_ops *ops, |
2ea28649 | 1720 | ptid_t ptid, int step, enum gdb_signal signo) |
d6b0e80f AC |
1721 | { |
1722 | struct lwp_info *lp; | |
d90e17a7 | 1723 | int resume_many; |
d6b0e80f | 1724 | |
76f50ad1 DJ |
1725 | if (debug_linux_nat) |
1726 | fprintf_unfiltered (gdb_stdlog, | |
1727 | "LLR: Preparing to %s %s, %s, inferior_ptid %s\n", | |
1728 | step ? "step" : "resume", | |
1729 | target_pid_to_str (ptid), | |
a493e3e2 | 1730 | (signo != GDB_SIGNAL_0 |
2ea28649 | 1731 | ? strsignal (gdb_signal_to_host (signo)) : "0"), |
76f50ad1 DJ |
1732 | target_pid_to_str (inferior_ptid)); |
1733 | ||
d6b0e80f | 1734 | /* A specific PTID means `step only this process id'. */ |
d90e17a7 PA |
1735 | resume_many = (ptid_equal (minus_one_ptid, ptid) |
1736 | || ptid_is_pid (ptid)); | |
4c28f408 | 1737 | |
e3e9f5a2 PA |
1738 | /* Mark the lwps we're resuming as resumed. */ |
1739 | iterate_over_lwps (ptid, resume_set_callback, NULL); | |
d6b0e80f | 1740 | |
d90e17a7 PA |
1741 | /* See if it's the current inferior that should be handled |
1742 | specially. */ | |
1743 | if (resume_many) | |
1744 | lp = find_lwp_pid (inferior_ptid); | |
1745 | else | |
1746 | lp = find_lwp_pid (ptid); | |
9f0bdab8 | 1747 | gdb_assert (lp != NULL); |
d6b0e80f | 1748 | |
9f0bdab8 | 1749 | /* Remember if we're stepping. */ |
25289eb2 | 1750 | lp->last_resume_kind = step ? resume_step : resume_continue; |
d6b0e80f | 1751 | |
9f0bdab8 DJ |
1752 | /* If we have a pending wait status for this thread, there is no |
1753 | point in resuming the process. But first make sure that | |
1754 | linux_nat_wait won't preemptively handle the event - we | |
1755 | should never take this short-circuit if we are going to | |
1756 | leave LP running, since we have skipped resuming all the | |
1757 | other threads. This bit of code needs to be synchronized | |
1758 | with linux_nat_wait. */ | |
76f50ad1 | 1759 | |
9f0bdab8 DJ |
1760 | if (lp->status && WIFSTOPPED (lp->status)) |
1761 | { | |
2455069d UW |
1762 | if (!lp->step |
1763 | && WSTOPSIG (lp->status) | |
1764 | && sigismember (&pass_mask, WSTOPSIG (lp->status))) | |
d6b0e80f | 1765 | { |
9f0bdab8 DJ |
1766 | if (debug_linux_nat) |
1767 | fprintf_unfiltered (gdb_stdlog, | |
1768 | "LLR: Not short circuiting for ignored " | |
1769 | "status 0x%x\n", lp->status); | |
1770 | ||
d6b0e80f AC |
1771 | /* FIXME: What should we do if we are supposed to continue |
1772 | this thread with a signal? */ | |
a493e3e2 | 1773 | gdb_assert (signo == GDB_SIGNAL_0); |
2ea28649 | 1774 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
9f0bdab8 DJ |
1775 | lp->status = 0; |
1776 | } | |
1777 | } | |
76f50ad1 | 1778 | |
8a99810d | 1779 | if (lwp_status_pending_p (lp)) |
9f0bdab8 DJ |
1780 | { |
1781 | /* FIXME: What should we do if we are supposed to continue | |
1782 | this thread with a signal? */ | |
a493e3e2 | 1783 | gdb_assert (signo == GDB_SIGNAL_0); |
76f50ad1 | 1784 | |
9f0bdab8 DJ |
1785 | if (debug_linux_nat) |
1786 | fprintf_unfiltered (gdb_stdlog, | |
1787 | "LLR: Short circuiting for status 0x%x\n", | |
1788 | lp->status); | |
d6b0e80f | 1789 | |
7feb7d06 PA |
1790 | if (target_can_async_p ()) |
1791 | { | |
1792 | target_async (inferior_event_handler, 0); | |
1793 | /* Tell the event loop we have something to process. */ | |
1794 | async_file_mark (); | |
1795 | } | |
9f0bdab8 | 1796 | return; |
d6b0e80f AC |
1797 | } |
1798 | ||
d90e17a7 | 1799 | if (resume_many) |
8817a6f2 | 1800 | iterate_over_lwps (ptid, linux_nat_resume_callback, lp); |
d90e17a7 | 1801 | |
d6b0e80f AC |
1802 | if (debug_linux_nat) |
1803 | fprintf_unfiltered (gdb_stdlog, | |
1804 | "LLR: %s %s, %s (resume event thread)\n", | |
1805 | step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
2bf6fb9d | 1806 | target_pid_to_str (lp->ptid), |
a493e3e2 | 1807 | (signo != GDB_SIGNAL_0 |
2ea28649 | 1808 | ? strsignal (gdb_signal_to_host (signo)) : "0")); |
b84876c2 | 1809 | |
2bf6fb9d PA |
1810 | linux_resume_one_lwp (lp, step, signo); |
1811 | ||
b84876c2 | 1812 | if (target_can_async_p ()) |
8ea051c5 | 1813 | target_async (inferior_event_handler, 0); |
d6b0e80f AC |
1814 | } |
1815 | ||
c5f62d5f | 1816 | /* Send a signal to an LWP. */ |
d6b0e80f AC |
1817 | |
1818 | static int | |
1819 | kill_lwp (int lwpid, int signo) | |
1820 | { | |
c5f62d5f DE |
1821 | /* Use tkill, if possible, in case we are using nptl threads. If tkill |
1822 | fails, then we are not using nptl threads and we should be using kill. */ | |
d6b0e80f AC |
1823 | |
1824 | #ifdef HAVE_TKILL_SYSCALL | |
c5f62d5f DE |
1825 | { |
1826 | static int tkill_failed; | |
1827 | ||
1828 | if (!tkill_failed) | |
1829 | { | |
1830 | int ret; | |
1831 | ||
1832 | errno = 0; | |
1833 | ret = syscall (__NR_tkill, lwpid, signo); | |
1834 | if (errno != ENOSYS) | |
1835 | return ret; | |
1836 | tkill_failed = 1; | |
1837 | } | |
1838 | } | |
d6b0e80f AC |
1839 | #endif |
1840 | ||
1841 | return kill (lwpid, signo); | |
1842 | } | |
1843 | ||
ca2163eb PA |
1844 | /* Handle a GNU/Linux syscall trap wait response. If we see a syscall |
1845 | event, check if the core is interested in it: if not, ignore the | |
1846 | event, and keep waiting; otherwise, we need to toggle the LWP's | |
1847 | syscall entry/exit status, since the ptrace event itself doesn't | |
1848 | indicate it, and report the trap to higher layers. */ | |
1849 | ||
1850 | static int | |
1851 | linux_handle_syscall_trap (struct lwp_info *lp, int stopping) | |
1852 | { | |
1853 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
1854 | struct gdbarch *gdbarch = target_thread_architecture (lp->ptid); | |
1855 | int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid); | |
1856 | ||
1857 | if (stopping) | |
1858 | { | |
1859 | /* If we're stopping threads, there's a SIGSTOP pending, which | |
1860 | makes it so that the LWP reports an immediate syscall return, | |
1861 | followed by the SIGSTOP. Skip seeing that "return" using | |
1862 | PTRACE_CONT directly, and let stop_wait_callback collect the | |
1863 | SIGSTOP. Later when the thread is resumed, a new syscall | |
1864 | entry event. If we didn't do this (and returned 0), we'd | |
1865 | leave a syscall entry pending, and our caller, by using | |
1866 | PTRACE_CONT to collect the SIGSTOP, skips the syscall return | |
1867 | itself. Later, when the user re-resumes this LWP, we'd see | |
1868 | another syscall entry event and we'd mistake it for a return. | |
1869 | ||
1870 | If stop_wait_callback didn't force the SIGSTOP out of the LWP | |
1871 | (leaving immediately with LWP->signalled set, without issuing | |
1872 | a PTRACE_CONT), it would still be problematic to leave this | |
1873 | syscall enter pending, as later when the thread is resumed, | |
1874 | it would then see the same syscall exit mentioned above, | |
1875 | followed by the delayed SIGSTOP, while the syscall didn't | |
1876 | actually get to execute. It seems it would be even more | |
1877 | confusing to the user. */ | |
1878 | ||
1879 | if (debug_linux_nat) | |
1880 | fprintf_unfiltered (gdb_stdlog, | |
1881 | "LHST: ignoring syscall %d " | |
1882 | "for LWP %ld (stopping threads), " | |
1883 | "resuming with PTRACE_CONT for SIGSTOP\n", | |
1884 | syscall_number, | |
dfd4cc63 | 1885 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1886 | |
1887 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
dfd4cc63 | 1888 | ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0); |
8817a6f2 | 1889 | lp->stopped = 0; |
ca2163eb PA |
1890 | return 1; |
1891 | } | |
1892 | ||
1893 | if (catch_syscall_enabled ()) | |
1894 | { | |
1895 | /* Always update the entry/return state, even if this particular | |
1896 | syscall isn't interesting to the core now. In async mode, | |
1897 | the user could install a new catchpoint for this syscall | |
1898 | between syscall enter/return, and we'll need to know to | |
1899 | report a syscall return if that happens. */ | |
1900 | lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1901 | ? TARGET_WAITKIND_SYSCALL_RETURN | |
1902 | : TARGET_WAITKIND_SYSCALL_ENTRY); | |
1903 | ||
1904 | if (catching_syscall_number (syscall_number)) | |
1905 | { | |
1906 | /* Alright, an event to report. */ | |
1907 | ourstatus->kind = lp->syscall_state; | |
1908 | ourstatus->value.syscall_number = syscall_number; | |
1909 | ||
1910 | if (debug_linux_nat) | |
1911 | fprintf_unfiltered (gdb_stdlog, | |
1912 | "LHST: stopping for %s of syscall %d" | |
1913 | " for LWP %ld\n", | |
3e43a32a MS |
1914 | lp->syscall_state |
1915 | == TARGET_WAITKIND_SYSCALL_ENTRY | |
ca2163eb PA |
1916 | ? "entry" : "return", |
1917 | syscall_number, | |
dfd4cc63 | 1918 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1919 | return 0; |
1920 | } | |
1921 | ||
1922 | if (debug_linux_nat) | |
1923 | fprintf_unfiltered (gdb_stdlog, | |
1924 | "LHST: ignoring %s of syscall %d " | |
1925 | "for LWP %ld\n", | |
1926 | lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1927 | ? "entry" : "return", | |
1928 | syscall_number, | |
dfd4cc63 | 1929 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1930 | } |
1931 | else | |
1932 | { | |
1933 | /* If we had been syscall tracing, and hence used PT_SYSCALL | |
1934 | before on this LWP, it could happen that the user removes all | |
1935 | syscall catchpoints before we get to process this event. | |
1936 | There are two noteworthy issues here: | |
1937 | ||
1938 | - When stopped at a syscall entry event, resuming with | |
1939 | PT_STEP still resumes executing the syscall and reports a | |
1940 | syscall return. | |
1941 | ||
1942 | - Only PT_SYSCALL catches syscall enters. If we last | |
1943 | single-stepped this thread, then this event can't be a | |
1944 | syscall enter. If we last single-stepped this thread, this | |
1945 | has to be a syscall exit. | |
1946 | ||
1947 | The points above mean that the next resume, be it PT_STEP or | |
1948 | PT_CONTINUE, can not trigger a syscall trace event. */ | |
1949 | if (debug_linux_nat) | |
1950 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
1951 | "LHST: caught syscall event " |
1952 | "with no syscall catchpoints." | |
ca2163eb PA |
1953 | " %d for LWP %ld, ignoring\n", |
1954 | syscall_number, | |
dfd4cc63 | 1955 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1956 | lp->syscall_state = TARGET_WAITKIND_IGNORE; |
1957 | } | |
1958 | ||
1959 | /* The core isn't interested in this event. For efficiency, avoid | |
1960 | stopping all threads only to have the core resume them all again. | |
1961 | Since we're not stopping threads, if we're still syscall tracing | |
1962 | and not stepping, we can't use PTRACE_CONT here, as we'd miss any | |
1963 | subsequent syscall. Simply resume using the inf-ptrace layer, | |
1964 | which knows when to use PT_SYSCALL or PT_CONTINUE. */ | |
1965 | ||
8a99810d | 1966 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
ca2163eb PA |
1967 | return 1; |
1968 | } | |
1969 | ||
3d799a95 DJ |
1970 | /* Handle a GNU/Linux extended wait response. If we see a clone |
1971 | event, we need to add the new LWP to our list (and not report the | |
1972 | trap to higher layers). This function returns non-zero if the | |
1973 | event should be ignored and we should wait again. If STOPPING is | |
1974 | true, the new LWP remains stopped, otherwise it is continued. */ | |
d6b0e80f AC |
1975 | |
1976 | static int | |
3d799a95 DJ |
1977 | linux_handle_extended_wait (struct lwp_info *lp, int status, |
1978 | int stopping) | |
d6b0e80f | 1979 | { |
dfd4cc63 | 1980 | int pid = ptid_get_lwp (lp->ptid); |
3d799a95 | 1981 | struct target_waitstatus *ourstatus = &lp->waitstatus; |
89a5711c | 1982 | int event = linux_ptrace_get_extended_event (status); |
d6b0e80f | 1983 | |
3d799a95 DJ |
1984 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
1985 | || event == PTRACE_EVENT_CLONE) | |
d6b0e80f | 1986 | { |
3d799a95 DJ |
1987 | unsigned long new_pid; |
1988 | int ret; | |
1989 | ||
1990 | ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); | |
6fc19103 | 1991 | |
3d799a95 DJ |
1992 | /* If we haven't already seen the new PID stop, wait for it now. */ |
1993 | if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
1994 | { | |
1995 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
1996 | hits the SIGSTOP, but we're already attached. */ | |
1997 | ret = my_waitpid (new_pid, &status, | |
1998 | (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0); | |
1999 | if (ret == -1) | |
2000 | perror_with_name (_("waiting for new child")); | |
2001 | else if (ret != new_pid) | |
2002 | internal_error (__FILE__, __LINE__, | |
2003 | _("wait returned unexpected PID %d"), ret); | |
2004 | else if (!WIFSTOPPED (status)) | |
2005 | internal_error (__FILE__, __LINE__, | |
2006 | _("wait returned unexpected status 0x%x"), status); | |
2007 | } | |
2008 | ||
3a3e9ee3 | 2009 | ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0); |
3d799a95 | 2010 | |
26cb8b7c PA |
2011 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) |
2012 | { | |
2013 | /* The arch-specific native code may need to know about new | |
2014 | forks even if those end up never mapped to an | |
2015 | inferior. */ | |
2016 | if (linux_nat_new_fork != NULL) | |
2017 | linux_nat_new_fork (lp, new_pid); | |
2018 | } | |
2019 | ||
2277426b | 2020 | if (event == PTRACE_EVENT_FORK |
dfd4cc63 | 2021 | && linux_fork_checkpointing_p (ptid_get_pid (lp->ptid))) |
2277426b | 2022 | { |
2277426b PA |
2023 | /* Handle checkpointing by linux-fork.c here as a special |
2024 | case. We don't want the follow-fork-mode or 'catch fork' | |
2025 | to interfere with this. */ | |
2026 | ||
2027 | /* This won't actually modify the breakpoint list, but will | |
2028 | physically remove the breakpoints from the child. */ | |
d80ee84f | 2029 | detach_breakpoints (ptid_build (new_pid, new_pid, 0)); |
2277426b PA |
2030 | |
2031 | /* Retain child fork in ptrace (stopped) state. */ | |
14571dad MS |
2032 | if (!find_fork_pid (new_pid)) |
2033 | add_fork (new_pid); | |
2277426b PA |
2034 | |
2035 | /* Report as spurious, so that infrun doesn't want to follow | |
2036 | this fork. We're actually doing an infcall in | |
2037 | linux-fork.c. */ | |
2038 | ourstatus->kind = TARGET_WAITKIND_SPURIOUS; | |
2277426b PA |
2039 | |
2040 | /* Report the stop to the core. */ | |
2041 | return 0; | |
2042 | } | |
2043 | ||
3d799a95 DJ |
2044 | if (event == PTRACE_EVENT_FORK) |
2045 | ourstatus->kind = TARGET_WAITKIND_FORKED; | |
2046 | else if (event == PTRACE_EVENT_VFORK) | |
2047 | ourstatus->kind = TARGET_WAITKIND_VFORKED; | |
6fc19103 | 2048 | else |
3d799a95 | 2049 | { |
78768c4a JK |
2050 | struct lwp_info *new_lp; |
2051 | ||
3d799a95 | 2052 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
78768c4a | 2053 | |
3c4d7e12 PA |
2054 | if (debug_linux_nat) |
2055 | fprintf_unfiltered (gdb_stdlog, | |
2056 | "LHEW: Got clone event " | |
2057 | "from LWP %d, new child is LWP %ld\n", | |
2058 | pid, new_pid); | |
2059 | ||
dfd4cc63 | 2060 | new_lp = add_lwp (ptid_build (ptid_get_pid (lp->ptid), new_pid, 0)); |
3d799a95 | 2061 | new_lp->cloned = 1; |
4c28f408 | 2062 | new_lp->stopped = 1; |
d6b0e80f | 2063 | |
3d799a95 DJ |
2064 | if (WSTOPSIG (status) != SIGSTOP) |
2065 | { | |
2066 | /* This can happen if someone starts sending signals to | |
2067 | the new thread before it gets a chance to run, which | |
2068 | have a lower number than SIGSTOP (e.g. SIGUSR1). | |
2069 | This is an unlikely case, and harder to handle for | |
2070 | fork / vfork than for clone, so we do not try - but | |
2071 | we handle it for clone events here. We'll send | |
2072 | the other signal on to the thread below. */ | |
2073 | ||
2074 | new_lp->signalled = 1; | |
2075 | } | |
2076 | else | |
79395f92 PA |
2077 | { |
2078 | struct thread_info *tp; | |
2079 | ||
2080 | /* When we stop for an event in some other thread, and | |
2081 | pull the thread list just as this thread has cloned, | |
2082 | we'll have seen the new thread in the thread_db list | |
2083 | before handling the CLONE event (glibc's | |
2084 | pthread_create adds the new thread to the thread list | |
2085 | before clone'ing, and has the kernel fill in the | |
2086 | thread's tid on the clone call with | |
2087 | CLONE_PARENT_SETTID). If that happened, and the core | |
2088 | had requested the new thread to stop, we'll have | |
2089 | killed it with SIGSTOP. But since SIGSTOP is not an | |
2090 | RT signal, it can only be queued once. We need to be | |
2091 | careful to not resume the LWP if we wanted it to | |
2092 | stop. In that case, we'll leave the SIGSTOP pending. | |
a493e3e2 | 2093 | It will later be reported as GDB_SIGNAL_0. */ |
79395f92 PA |
2094 | tp = find_thread_ptid (new_lp->ptid); |
2095 | if (tp != NULL && tp->stop_requested) | |
2096 | new_lp->last_resume_kind = resume_stop; | |
2097 | else | |
2098 | status = 0; | |
2099 | } | |
d6b0e80f | 2100 | |
2db9a427 PA |
2101 | /* If the thread_db layer is active, let it record the user |
2102 | level thread id and status, and add the thread to GDB's | |
2103 | list. */ | |
2104 | if (!thread_db_notice_clone (lp->ptid, new_lp->ptid)) | |
3d799a95 | 2105 | { |
2db9a427 PA |
2106 | /* The process is not using thread_db. Add the LWP to |
2107 | GDB's list. */ | |
2108 | target_post_attach (ptid_get_lwp (new_lp->ptid)); | |
2109 | add_thread (new_lp->ptid); | |
2110 | } | |
4c28f408 | 2111 | |
2db9a427 PA |
2112 | if (!stopping) |
2113 | { | |
2114 | set_running (new_lp->ptid, 1); | |
2115 | set_executing (new_lp->ptid, 1); | |
2116 | /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced | |
2117 | resume_stop. */ | |
2118 | new_lp->last_resume_kind = resume_continue; | |
4c28f408 PA |
2119 | } |
2120 | ||
79395f92 PA |
2121 | if (status != 0) |
2122 | { | |
2123 | /* We created NEW_LP so it cannot yet contain STATUS. */ | |
2124 | gdb_assert (new_lp->status == 0); | |
2125 | ||
2126 | /* Save the wait status to report later. */ | |
2127 | if (debug_linux_nat) | |
2128 | fprintf_unfiltered (gdb_stdlog, | |
2129 | "LHEW: waitpid of new LWP %ld, " | |
2130 | "saving status %s\n", | |
dfd4cc63 | 2131 | (long) ptid_get_lwp (new_lp->ptid), |
79395f92 PA |
2132 | status_to_str (status)); |
2133 | new_lp->status = status; | |
2134 | } | |
2135 | ||
20ba1ce6 | 2136 | new_lp->resumed = !stopping; |
3d799a95 DJ |
2137 | return 1; |
2138 | } | |
2139 | ||
2140 | return 0; | |
d6b0e80f AC |
2141 | } |
2142 | ||
3d799a95 DJ |
2143 | if (event == PTRACE_EVENT_EXEC) |
2144 | { | |
a75724bc PA |
2145 | if (debug_linux_nat) |
2146 | fprintf_unfiltered (gdb_stdlog, | |
2147 | "LHEW: Got exec event from LWP %ld\n", | |
dfd4cc63 | 2148 | ptid_get_lwp (lp->ptid)); |
a75724bc | 2149 | |
3d799a95 DJ |
2150 | ourstatus->kind = TARGET_WAITKIND_EXECD; |
2151 | ourstatus->value.execd_pathname | |
8dd27370 | 2152 | = xstrdup (linux_child_pid_to_exec_file (NULL, pid)); |
3d799a95 | 2153 | |
8af756ef PA |
2154 | /* The thread that execed must have been resumed, but, when a |
2155 | thread execs, it changes its tid to the tgid, and the old | |
2156 | tgid thread might have not been resumed. */ | |
2157 | lp->resumed = 1; | |
6c95b8df PA |
2158 | return 0; |
2159 | } | |
2160 | ||
2161 | if (event == PTRACE_EVENT_VFORK_DONE) | |
2162 | { | |
2163 | if (current_inferior ()->waiting_for_vfork_done) | |
3d799a95 | 2164 | { |
6c95b8df | 2165 | if (debug_linux_nat) |
3e43a32a MS |
2166 | fprintf_unfiltered (gdb_stdlog, |
2167 | "LHEW: Got expected PTRACE_EVENT_" | |
2168 | "VFORK_DONE from LWP %ld: stopping\n", | |
dfd4cc63 | 2169 | ptid_get_lwp (lp->ptid)); |
3d799a95 | 2170 | |
6c95b8df PA |
2171 | ourstatus->kind = TARGET_WAITKIND_VFORK_DONE; |
2172 | return 0; | |
3d799a95 DJ |
2173 | } |
2174 | ||
6c95b8df | 2175 | if (debug_linux_nat) |
3e43a32a MS |
2176 | fprintf_unfiltered (gdb_stdlog, |
2177 | "LHEW: Got PTRACE_EVENT_VFORK_DONE " | |
20ba1ce6 | 2178 | "from LWP %ld: ignoring\n", |
dfd4cc63 | 2179 | ptid_get_lwp (lp->ptid)); |
6c95b8df | 2180 | return 1; |
3d799a95 DJ |
2181 | } |
2182 | ||
2183 | internal_error (__FILE__, __LINE__, | |
2184 | _("unknown ptrace event %d"), event); | |
d6b0e80f AC |
2185 | } |
2186 | ||
2187 | /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has | |
2188 | exited. */ | |
2189 | ||
2190 | static int | |
2191 | wait_lwp (struct lwp_info *lp) | |
2192 | { | |
2193 | pid_t pid; | |
432b4d03 | 2194 | int status = 0; |
d6b0e80f | 2195 | int thread_dead = 0; |
432b4d03 | 2196 | sigset_t prev_mask; |
d6b0e80f AC |
2197 | |
2198 | gdb_assert (!lp->stopped); | |
2199 | gdb_assert (lp->status == 0); | |
2200 | ||
432b4d03 JK |
2201 | /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
2202 | block_child_signals (&prev_mask); | |
2203 | ||
2204 | for (;;) | |
d6b0e80f | 2205 | { |
432b4d03 JK |
2206 | /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind |
2207 | was right and we should just call sigsuspend. */ | |
2208 | ||
dfd4cc63 | 2209 | pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, WNOHANG); |
d6b0e80f | 2210 | if (pid == -1 && errno == ECHILD) |
dfd4cc63 | 2211 | pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, __WCLONE | WNOHANG); |
a9f4bb21 PA |
2212 | if (pid == -1 && errno == ECHILD) |
2213 | { | |
2214 | /* The thread has previously exited. We need to delete it | |
2215 | now because, for some vendor 2.4 kernels with NPTL | |
2216 | support backported, there won't be an exit event unless | |
2217 | it is the main thread. 2.6 kernels will report an exit | |
2218 | event for each thread that exits, as expected. */ | |
2219 | thread_dead = 1; | |
2220 | if (debug_linux_nat) | |
2221 | fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n", | |
2222 | target_pid_to_str (lp->ptid)); | |
2223 | } | |
432b4d03 JK |
2224 | if (pid != 0) |
2225 | break; | |
2226 | ||
2227 | /* Bugs 10970, 12702. | |
2228 | Thread group leader may have exited in which case we'll lock up in | |
2229 | waitpid if there are other threads, even if they are all zombies too. | |
2230 | Basically, we're not supposed to use waitpid this way. | |
2231 | __WCLONE is not applicable for the leader so we can't use that. | |
2232 | LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED | |
2233 | process; it gets ESRCH both for the zombie and for running processes. | |
2234 | ||
2235 | As a workaround, check if we're waiting for the thread group leader and | |
2236 | if it's a zombie, and avoid calling waitpid if it is. | |
2237 | ||
2238 | This is racy, what if the tgl becomes a zombie right after we check? | |
2239 | Therefore always use WNOHANG with sigsuspend - it is equivalent to | |
5f572dec | 2240 | waiting waitpid but linux_proc_pid_is_zombie is safe this way. */ |
432b4d03 | 2241 | |
dfd4cc63 LM |
2242 | if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid) |
2243 | && linux_proc_pid_is_zombie (ptid_get_lwp (lp->ptid))) | |
d6b0e80f | 2244 | { |
d6b0e80f AC |
2245 | thread_dead = 1; |
2246 | if (debug_linux_nat) | |
432b4d03 JK |
2247 | fprintf_unfiltered (gdb_stdlog, |
2248 | "WL: Thread group leader %s vanished.\n", | |
d6b0e80f | 2249 | target_pid_to_str (lp->ptid)); |
432b4d03 | 2250 | break; |
d6b0e80f | 2251 | } |
432b4d03 JK |
2252 | |
2253 | /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers | |
2254 | get invoked despite our caller had them intentionally blocked by | |
2255 | block_child_signals. This is sensitive only to the loop of | |
2256 | linux_nat_wait_1 and there if we get called my_waitpid gets called | |
2257 | again before it gets to sigsuspend so we can safely let the handlers | |
2258 | get executed here. */ | |
2259 | ||
d36bf488 DE |
2260 | if (debug_linux_nat) |
2261 | fprintf_unfiltered (gdb_stdlog, "WL: about to sigsuspend\n"); | |
432b4d03 JK |
2262 | sigsuspend (&suspend_mask); |
2263 | } | |
2264 | ||
2265 | restore_child_signals_mask (&prev_mask); | |
2266 | ||
d6b0e80f AC |
2267 | if (!thread_dead) |
2268 | { | |
dfd4cc63 | 2269 | gdb_assert (pid == ptid_get_lwp (lp->ptid)); |
d6b0e80f AC |
2270 | |
2271 | if (debug_linux_nat) | |
2272 | { | |
2273 | fprintf_unfiltered (gdb_stdlog, | |
2274 | "WL: waitpid %s received %s\n", | |
2275 | target_pid_to_str (lp->ptid), | |
2276 | status_to_str (status)); | |
2277 | } | |
d6b0e80f | 2278 | |
a9f4bb21 PA |
2279 | /* Check if the thread has exited. */ |
2280 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
2281 | { | |
2282 | thread_dead = 1; | |
2283 | if (debug_linux_nat) | |
2284 | fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n", | |
2285 | target_pid_to_str (lp->ptid)); | |
2286 | } | |
d6b0e80f AC |
2287 | } |
2288 | ||
2289 | if (thread_dead) | |
2290 | { | |
e26af52f | 2291 | exit_lwp (lp); |
d6b0e80f AC |
2292 | return 0; |
2293 | } | |
2294 | ||
2295 | gdb_assert (WIFSTOPPED (status)); | |
8817a6f2 | 2296 | lp->stopped = 1; |
d6b0e80f | 2297 | |
8784d563 PA |
2298 | if (lp->must_set_ptrace_flags) |
2299 | { | |
2300 | struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid)); | |
2301 | ||
2302 | linux_enable_event_reporting (ptid_get_lwp (lp->ptid), inf->attach_flag); | |
2303 | lp->must_set_ptrace_flags = 0; | |
2304 | } | |
2305 | ||
ca2163eb PA |
2306 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2307 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2308 | { | |
2309 | /* No longer need the sysgood bit. The ptrace event ends up | |
2310 | recorded in lp->waitstatus if we care for it. We can carry | |
2311 | on handling the event like a regular SIGTRAP from here | |
2312 | on. */ | |
2313 | status = W_STOPCODE (SIGTRAP); | |
2314 | if (linux_handle_syscall_trap (lp, 1)) | |
2315 | return wait_lwp (lp); | |
2316 | } | |
2317 | ||
d6b0e80f | 2318 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2319 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2320 | && linux_is_extended_waitstatus (status)) | |
d6b0e80f AC |
2321 | { |
2322 | if (debug_linux_nat) | |
2323 | fprintf_unfiltered (gdb_stdlog, | |
2324 | "WL: Handling extended status 0x%06x\n", | |
2325 | status); | |
20ba1ce6 PA |
2326 | linux_handle_extended_wait (lp, status, 1); |
2327 | return 0; | |
d6b0e80f AC |
2328 | } |
2329 | ||
2330 | return status; | |
2331 | } | |
2332 | ||
2333 | /* Send a SIGSTOP to LP. */ | |
2334 | ||
2335 | static int | |
2336 | stop_callback (struct lwp_info *lp, void *data) | |
2337 | { | |
2338 | if (!lp->stopped && !lp->signalled) | |
2339 | { | |
2340 | int ret; | |
2341 | ||
2342 | if (debug_linux_nat) | |
2343 | { | |
2344 | fprintf_unfiltered (gdb_stdlog, | |
2345 | "SC: kill %s **<SIGSTOP>**\n", | |
2346 | target_pid_to_str (lp->ptid)); | |
2347 | } | |
2348 | errno = 0; | |
dfd4cc63 | 2349 | ret = kill_lwp (ptid_get_lwp (lp->ptid), SIGSTOP); |
d6b0e80f AC |
2350 | if (debug_linux_nat) |
2351 | { | |
2352 | fprintf_unfiltered (gdb_stdlog, | |
2353 | "SC: lwp kill %d %s\n", | |
2354 | ret, | |
2355 | errno ? safe_strerror (errno) : "ERRNO-OK"); | |
2356 | } | |
2357 | ||
2358 | lp->signalled = 1; | |
2359 | gdb_assert (lp->status == 0); | |
2360 | } | |
2361 | ||
2362 | return 0; | |
2363 | } | |
2364 | ||
7b50312a PA |
2365 | /* Request a stop on LWP. */ |
2366 | ||
2367 | void | |
2368 | linux_stop_lwp (struct lwp_info *lwp) | |
2369 | { | |
2370 | stop_callback (lwp, NULL); | |
2371 | } | |
2372 | ||
2db9a427 PA |
2373 | /* See linux-nat.h */ |
2374 | ||
2375 | void | |
2376 | linux_stop_and_wait_all_lwps (void) | |
2377 | { | |
2378 | /* Stop all LWP's ... */ | |
2379 | iterate_over_lwps (minus_one_ptid, stop_callback, NULL); | |
2380 | ||
2381 | /* ... and wait until all of them have reported back that | |
2382 | they're no longer running. */ | |
2383 | iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL); | |
2384 | } | |
2385 | ||
2386 | /* See linux-nat.h */ | |
2387 | ||
2388 | void | |
2389 | linux_unstop_all_lwps (void) | |
2390 | { | |
2391 | iterate_over_lwps (minus_one_ptid, | |
2392 | resume_stopped_resumed_lwps, &minus_one_ptid); | |
2393 | } | |
2394 | ||
57380f4e | 2395 | /* Return non-zero if LWP PID has a pending SIGINT. */ |
d6b0e80f AC |
2396 | |
2397 | static int | |
57380f4e DJ |
2398 | linux_nat_has_pending_sigint (int pid) |
2399 | { | |
2400 | sigset_t pending, blocked, ignored; | |
57380f4e DJ |
2401 | |
2402 | linux_proc_pending_signals (pid, &pending, &blocked, &ignored); | |
2403 | ||
2404 | if (sigismember (&pending, SIGINT) | |
2405 | && !sigismember (&ignored, SIGINT)) | |
2406 | return 1; | |
2407 | ||
2408 | return 0; | |
2409 | } | |
2410 | ||
2411 | /* Set a flag in LP indicating that we should ignore its next SIGINT. */ | |
2412 | ||
2413 | static int | |
2414 | set_ignore_sigint (struct lwp_info *lp, void *data) | |
d6b0e80f | 2415 | { |
57380f4e DJ |
2416 | /* If a thread has a pending SIGINT, consume it; otherwise, set a |
2417 | flag to consume the next one. */ | |
2418 | if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) | |
2419 | && WSTOPSIG (lp->status) == SIGINT) | |
2420 | lp->status = 0; | |
2421 | else | |
2422 | lp->ignore_sigint = 1; | |
2423 | ||
2424 | return 0; | |
2425 | } | |
2426 | ||
2427 | /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. | |
2428 | This function is called after we know the LWP has stopped; if the LWP | |
2429 | stopped before the expected SIGINT was delivered, then it will never have | |
2430 | arrived. Also, if the signal was delivered to a shared queue and consumed | |
2431 | by a different thread, it will never be delivered to this LWP. */ | |
d6b0e80f | 2432 | |
57380f4e DJ |
2433 | static void |
2434 | maybe_clear_ignore_sigint (struct lwp_info *lp) | |
2435 | { | |
2436 | if (!lp->ignore_sigint) | |
2437 | return; | |
2438 | ||
dfd4cc63 | 2439 | if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp->ptid))) |
57380f4e DJ |
2440 | { |
2441 | if (debug_linux_nat) | |
2442 | fprintf_unfiltered (gdb_stdlog, | |
2443 | "MCIS: Clearing bogus flag for %s\n", | |
2444 | target_pid_to_str (lp->ptid)); | |
2445 | lp->ignore_sigint = 0; | |
2446 | } | |
2447 | } | |
2448 | ||
ebec9a0f PA |
2449 | /* Fetch the possible triggered data watchpoint info and store it in |
2450 | LP. | |
2451 | ||
2452 | On some archs, like x86, that use debug registers to set | |
2453 | watchpoints, it's possible that the way to know which watched | |
2454 | address trapped, is to check the register that is used to select | |
2455 | which address to watch. Problem is, between setting the watchpoint | |
2456 | and reading back which data address trapped, the user may change | |
2457 | the set of watchpoints, and, as a consequence, GDB changes the | |
2458 | debug registers in the inferior. To avoid reading back a stale | |
2459 | stopped-data-address when that happens, we cache in LP the fact | |
2460 | that a watchpoint trapped, and the corresponding data address, as | |
2461 | soon as we see LP stop with a SIGTRAP. If GDB changes the debug | |
2462 | registers meanwhile, we have the cached data we can rely on. */ | |
2463 | ||
9c02b525 PA |
2464 | static int |
2465 | check_stopped_by_watchpoint (struct lwp_info *lp) | |
ebec9a0f PA |
2466 | { |
2467 | struct cleanup *old_chain; | |
2468 | ||
2469 | if (linux_ops->to_stopped_by_watchpoint == NULL) | |
9c02b525 | 2470 | return 0; |
ebec9a0f PA |
2471 | |
2472 | old_chain = save_inferior_ptid (); | |
2473 | inferior_ptid = lp->ptid; | |
2474 | ||
9c02b525 | 2475 | if (linux_ops->to_stopped_by_watchpoint (linux_ops)) |
ebec9a0f | 2476 | { |
15c66dd6 | 2477 | lp->stop_reason = TARGET_STOPPED_BY_WATCHPOINT; |
9c02b525 | 2478 | |
ebec9a0f PA |
2479 | if (linux_ops->to_stopped_data_address != NULL) |
2480 | lp->stopped_data_address_p = | |
2481 | linux_ops->to_stopped_data_address (¤t_target, | |
2482 | &lp->stopped_data_address); | |
2483 | else | |
2484 | lp->stopped_data_address_p = 0; | |
2485 | } | |
2486 | ||
2487 | do_cleanups (old_chain); | |
9c02b525 | 2488 | |
15c66dd6 | 2489 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
9c02b525 PA |
2490 | } |
2491 | ||
2492 | /* Called when the LWP stopped for a trap that could be explained by a | |
2493 | watchpoint or a breakpoint. */ | |
2494 | ||
2495 | static void | |
2496 | save_sigtrap (struct lwp_info *lp) | |
2497 | { | |
15c66dd6 | 2498 | gdb_assert (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON); |
9c02b525 PA |
2499 | gdb_assert (lp->status != 0); |
2500 | ||
faf09f01 PA |
2501 | /* Check first if this was a SW/HW breakpoint before checking |
2502 | watchpoints, because at least s390 can't tell the data address of | |
2503 | hardware watchpoint hits, and the kernel returns | |
2504 | stopped-by-watchpoint as long as there's a watchpoint set. */ | |
9c02b525 PA |
2505 | if (linux_nat_status_is_event (lp->status)) |
2506 | check_stopped_by_breakpoint (lp); | |
faf09f01 PA |
2507 | |
2508 | /* Note that TRAP_HWBKPT can indicate either a hardware breakpoint | |
2509 | or hardware watchpoint. Check which is which if we got | |
2510 | TARGET_STOPPED_BY_HW_BREAKPOINT. */ | |
2511 | if (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON | |
2512 | || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) | |
2513 | check_stopped_by_watchpoint (lp); | |
ebec9a0f PA |
2514 | } |
2515 | ||
9c02b525 | 2516 | /* Returns true if the LWP had stopped for a watchpoint. */ |
ebec9a0f PA |
2517 | |
2518 | static int | |
6a109b6b | 2519 | linux_nat_stopped_by_watchpoint (struct target_ops *ops) |
ebec9a0f PA |
2520 | { |
2521 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2522 | ||
2523 | gdb_assert (lp != NULL); | |
2524 | ||
15c66dd6 | 2525 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
ebec9a0f PA |
2526 | } |
2527 | ||
2528 | static int | |
2529 | linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p) | |
2530 | { | |
2531 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2532 | ||
2533 | gdb_assert (lp != NULL); | |
2534 | ||
2535 | *addr_p = lp->stopped_data_address; | |
2536 | ||
2537 | return lp->stopped_data_address_p; | |
2538 | } | |
2539 | ||
26ab7092 JK |
2540 | /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
2541 | ||
2542 | static int | |
2543 | sigtrap_is_event (int status) | |
2544 | { | |
2545 | return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; | |
2546 | } | |
2547 | ||
26ab7092 JK |
2548 | /* Set alternative SIGTRAP-like events recognizer. If |
2549 | breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be | |
2550 | applied. */ | |
2551 | ||
2552 | void | |
2553 | linux_nat_set_status_is_event (struct target_ops *t, | |
2554 | int (*status_is_event) (int status)) | |
2555 | { | |
2556 | linux_nat_status_is_event = status_is_event; | |
2557 | } | |
2558 | ||
57380f4e DJ |
2559 | /* Wait until LP is stopped. */ |
2560 | ||
2561 | static int | |
2562 | stop_wait_callback (struct lwp_info *lp, void *data) | |
2563 | { | |
c9657e70 | 2564 | struct inferior *inf = find_inferior_ptid (lp->ptid); |
6c95b8df PA |
2565 | |
2566 | /* If this is a vfork parent, bail out, it is not going to report | |
2567 | any SIGSTOP until the vfork is done with. */ | |
2568 | if (inf->vfork_child != NULL) | |
2569 | return 0; | |
2570 | ||
d6b0e80f AC |
2571 | if (!lp->stopped) |
2572 | { | |
2573 | int status; | |
2574 | ||
2575 | status = wait_lwp (lp); | |
2576 | if (status == 0) | |
2577 | return 0; | |
2578 | ||
57380f4e DJ |
2579 | if (lp->ignore_sigint && WIFSTOPPED (status) |
2580 | && WSTOPSIG (status) == SIGINT) | |
d6b0e80f | 2581 | { |
57380f4e | 2582 | lp->ignore_sigint = 0; |
d6b0e80f AC |
2583 | |
2584 | errno = 0; | |
dfd4cc63 | 2585 | ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0); |
8817a6f2 | 2586 | lp->stopped = 0; |
d6b0e80f AC |
2587 | if (debug_linux_nat) |
2588 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
2589 | "PTRACE_CONT %s, 0, 0 (%s) " |
2590 | "(discarding SIGINT)\n", | |
d6b0e80f AC |
2591 | target_pid_to_str (lp->ptid), |
2592 | errno ? safe_strerror (errno) : "OK"); | |
2593 | ||
57380f4e | 2594 | return stop_wait_callback (lp, NULL); |
d6b0e80f AC |
2595 | } |
2596 | ||
57380f4e DJ |
2597 | maybe_clear_ignore_sigint (lp); |
2598 | ||
d6b0e80f AC |
2599 | if (WSTOPSIG (status) != SIGSTOP) |
2600 | { | |
e5ef252a | 2601 | /* The thread was stopped with a signal other than SIGSTOP. */ |
7feb7d06 | 2602 | |
e5ef252a PA |
2603 | if (debug_linux_nat) |
2604 | fprintf_unfiltered (gdb_stdlog, | |
2605 | "SWC: Pending event %s in %s\n", | |
2606 | status_to_str ((int) status), | |
2607 | target_pid_to_str (lp->ptid)); | |
2608 | ||
2609 | /* Save the sigtrap event. */ | |
2610 | lp->status = status; | |
e5ef252a | 2611 | gdb_assert (lp->signalled); |
9c02b525 | 2612 | save_sigtrap (lp); |
d6b0e80f AC |
2613 | } |
2614 | else | |
2615 | { | |
2616 | /* We caught the SIGSTOP that we intended to catch, so | |
2617 | there's no SIGSTOP pending. */ | |
e5ef252a PA |
2618 | |
2619 | if (debug_linux_nat) | |
2620 | fprintf_unfiltered (gdb_stdlog, | |
2bf6fb9d | 2621 | "SWC: Expected SIGSTOP caught for %s.\n", |
e5ef252a PA |
2622 | target_pid_to_str (lp->ptid)); |
2623 | ||
e5ef252a PA |
2624 | /* Reset SIGNALLED only after the stop_wait_callback call |
2625 | above as it does gdb_assert on SIGNALLED. */ | |
d6b0e80f AC |
2626 | lp->signalled = 0; |
2627 | } | |
2628 | } | |
2629 | ||
2630 | return 0; | |
2631 | } | |
2632 | ||
9c02b525 PA |
2633 | /* Return non-zero if LP has a wait status pending. Discard the |
2634 | pending event and resume the LWP if the event that originally | |
2635 | caused the stop became uninteresting. */ | |
d6b0e80f AC |
2636 | |
2637 | static int | |
2638 | status_callback (struct lwp_info *lp, void *data) | |
2639 | { | |
2640 | /* Only report a pending wait status if we pretend that this has | |
2641 | indeed been resumed. */ | |
ca2163eb PA |
2642 | if (!lp->resumed) |
2643 | return 0; | |
2644 | ||
eb54c8bf PA |
2645 | if (!lwp_status_pending_p (lp)) |
2646 | return 0; | |
2647 | ||
15c66dd6 PA |
2648 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
2649 | || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) | |
9c02b525 PA |
2650 | { |
2651 | struct regcache *regcache = get_thread_regcache (lp->ptid); | |
2652 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
2653 | CORE_ADDR pc; | |
2654 | int discard = 0; | |
2655 | ||
9c02b525 PA |
2656 | pc = regcache_read_pc (regcache); |
2657 | ||
2658 | if (pc != lp->stop_pc) | |
2659 | { | |
2660 | if (debug_linux_nat) | |
2661 | fprintf_unfiltered (gdb_stdlog, | |
2662 | "SC: PC of %s changed. was=%s, now=%s\n", | |
2663 | target_pid_to_str (lp->ptid), | |
2664 | paddress (target_gdbarch (), lp->stop_pc), | |
2665 | paddress (target_gdbarch (), pc)); | |
2666 | discard = 1; | |
2667 | } | |
faf09f01 PA |
2668 | |
2669 | #if !USE_SIGTRAP_SIGINFO | |
9c02b525 PA |
2670 | else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
2671 | { | |
2672 | if (debug_linux_nat) | |
2673 | fprintf_unfiltered (gdb_stdlog, | |
2674 | "SC: previous breakpoint of %s, at %s gone\n", | |
2675 | target_pid_to_str (lp->ptid), | |
2676 | paddress (target_gdbarch (), lp->stop_pc)); | |
2677 | ||
2678 | discard = 1; | |
2679 | } | |
faf09f01 | 2680 | #endif |
9c02b525 PA |
2681 | |
2682 | if (discard) | |
2683 | { | |
2684 | if (debug_linux_nat) | |
2685 | fprintf_unfiltered (gdb_stdlog, | |
2686 | "SC: pending event of %s cancelled.\n", | |
2687 | target_pid_to_str (lp->ptid)); | |
2688 | ||
2689 | lp->status = 0; | |
2690 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); | |
2691 | return 0; | |
2692 | } | |
9c02b525 PA |
2693 | } |
2694 | ||
eb54c8bf | 2695 | return 1; |
d6b0e80f AC |
2696 | } |
2697 | ||
2698 | /* Return non-zero if LP isn't stopped. */ | |
2699 | ||
2700 | static int | |
2701 | running_callback (struct lwp_info *lp, void *data) | |
2702 | { | |
25289eb2 | 2703 | return (!lp->stopped |
8a99810d | 2704 | || (lwp_status_pending_p (lp) && lp->resumed)); |
d6b0e80f AC |
2705 | } |
2706 | ||
2707 | /* Count the LWP's that have had events. */ | |
2708 | ||
2709 | static int | |
2710 | count_events_callback (struct lwp_info *lp, void *data) | |
2711 | { | |
2712 | int *count = data; | |
2713 | ||
2714 | gdb_assert (count != NULL); | |
2715 | ||
9c02b525 PA |
2716 | /* Select only resumed LWPs that have an event pending. */ |
2717 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2718 | (*count)++; |
2719 | ||
2720 | return 0; | |
2721 | } | |
2722 | ||
2723 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
2724 | ||
2725 | static int | |
2726 | select_singlestep_lwp_callback (struct lwp_info *lp, void *data) | |
2727 | { | |
25289eb2 PA |
2728 | if (lp->last_resume_kind == resume_step |
2729 | && lp->status != 0) | |
d6b0e80f AC |
2730 | return 1; |
2731 | else | |
2732 | return 0; | |
2733 | } | |
2734 | ||
8a99810d PA |
2735 | /* Returns true if LP has a status pending. */ |
2736 | ||
2737 | static int | |
2738 | lwp_status_pending_p (struct lwp_info *lp) | |
2739 | { | |
2740 | /* We check for lp->waitstatus in addition to lp->status, because we | |
2741 | can have pending process exits recorded in lp->status and | |
2742 | W_EXITCODE(0,0) happens to be 0. */ | |
2743 | return lp->status != 0 || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE; | |
2744 | } | |
2745 | ||
b90fc188 | 2746 | /* Select the Nth LWP that has had an event. */ |
d6b0e80f AC |
2747 | |
2748 | static int | |
2749 | select_event_lwp_callback (struct lwp_info *lp, void *data) | |
2750 | { | |
2751 | int *selector = data; | |
2752 | ||
2753 | gdb_assert (selector != NULL); | |
2754 | ||
9c02b525 PA |
2755 | /* Select only resumed LWPs that have an event pending. */ |
2756 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2757 | if ((*selector)-- == 0) |
2758 | return 1; | |
2759 | ||
2760 | return 0; | |
2761 | } | |
2762 | ||
9c02b525 PA |
2763 | /* Called when the LWP got a signal/trap that could be explained by a |
2764 | software or hardware breakpoint. */ | |
2765 | ||
710151dd | 2766 | static int |
9c02b525 | 2767 | check_stopped_by_breakpoint (struct lwp_info *lp) |
710151dd PA |
2768 | { |
2769 | /* Arrange for a breakpoint to be hit again later. We don't keep | |
2770 | the SIGTRAP status and don't forward the SIGTRAP signal to the | |
2771 | LWP. We will handle the current event, eventually we will resume | |
2772 | this LWP, and this breakpoint will trap again. | |
2773 | ||
2774 | If we do not do this, then we run the risk that the user will | |
2775 | delete or disable the breakpoint, but the LWP will have already | |
2776 | tripped on it. */ | |
2777 | ||
515630c5 UW |
2778 | struct regcache *regcache = get_thread_regcache (lp->ptid); |
2779 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
2780 | CORE_ADDR pc; | |
9c02b525 | 2781 | CORE_ADDR sw_bp_pc; |
faf09f01 PA |
2782 | #if USE_SIGTRAP_SIGINFO |
2783 | siginfo_t siginfo; | |
2784 | #endif | |
9c02b525 PA |
2785 | |
2786 | pc = regcache_read_pc (regcache); | |
527a273a | 2787 | sw_bp_pc = pc - gdbarch_decr_pc_after_break (gdbarch); |
515630c5 | 2788 | |
faf09f01 PA |
2789 | #if USE_SIGTRAP_SIGINFO |
2790 | if (linux_nat_get_siginfo (lp->ptid, &siginfo)) | |
2791 | { | |
2792 | if (siginfo.si_signo == SIGTRAP) | |
2793 | { | |
2794 | if (siginfo.si_code == GDB_ARCH_TRAP_BRKPT) | |
2795 | { | |
2796 | if (debug_linux_nat) | |
2797 | fprintf_unfiltered (gdb_stdlog, | |
2bf6fb9d PA |
2798 | "CSBB: %s stopped by software " |
2799 | "breakpoint\n", | |
faf09f01 PA |
2800 | target_pid_to_str (lp->ptid)); |
2801 | ||
2802 | /* Back up the PC if necessary. */ | |
2803 | if (pc != sw_bp_pc) | |
2804 | regcache_write_pc (regcache, sw_bp_pc); | |
2805 | ||
2806 | lp->stop_pc = sw_bp_pc; | |
2807 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2808 | return 1; | |
2809 | } | |
2810 | else if (siginfo.si_code == TRAP_HWBKPT) | |
2811 | { | |
2812 | if (debug_linux_nat) | |
2813 | fprintf_unfiltered (gdb_stdlog, | |
2bf6fb9d PA |
2814 | "CSBB: %s stopped by hardware " |
2815 | "breakpoint/watchpoint\n", | |
faf09f01 PA |
2816 | target_pid_to_str (lp->ptid)); |
2817 | ||
2818 | lp->stop_pc = pc; | |
2819 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; | |
2820 | return 1; | |
2821 | } | |
2bf6fb9d PA |
2822 | else if (siginfo.si_code == TRAP_TRACE) |
2823 | { | |
2824 | if (debug_linux_nat) | |
2825 | fprintf_unfiltered (gdb_stdlog, | |
2826 | "CSBB: %s stopped by trace\n", | |
2827 | target_pid_to_str (lp->ptid)); | |
2828 | } | |
faf09f01 PA |
2829 | } |
2830 | } | |
2831 | #else | |
9c02b525 PA |
2832 | if ((!lp->step || lp->stop_pc == sw_bp_pc) |
2833 | && software_breakpoint_inserted_here_p (get_regcache_aspace (regcache), | |
2834 | sw_bp_pc)) | |
710151dd | 2835 | { |
9c02b525 PA |
2836 | /* The LWP was either continued, or stepped a software |
2837 | breakpoint instruction. */ | |
710151dd PA |
2838 | if (debug_linux_nat) |
2839 | fprintf_unfiltered (gdb_stdlog, | |
2bf6fb9d | 2840 | "CSBB: %s stopped by software breakpoint\n", |
710151dd PA |
2841 | target_pid_to_str (lp->ptid)); |
2842 | ||
2843 | /* Back up the PC if necessary. */ | |
9c02b525 PA |
2844 | if (pc != sw_bp_pc) |
2845 | regcache_write_pc (regcache, sw_bp_pc); | |
515630c5 | 2846 | |
9c02b525 | 2847 | lp->stop_pc = sw_bp_pc; |
15c66dd6 | 2848 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
710151dd PA |
2849 | return 1; |
2850 | } | |
710151dd | 2851 | |
9c02b525 PA |
2852 | if (hardware_breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
2853 | { | |
2854 | if (debug_linux_nat) | |
2855 | fprintf_unfiltered (gdb_stdlog, | |
2bf6fb9d | 2856 | "CSBB: stopped by hardware breakpoint %s\n", |
9c02b525 | 2857 | target_pid_to_str (lp->ptid)); |
d6b0e80f | 2858 | |
9c02b525 | 2859 | lp->stop_pc = pc; |
15c66dd6 | 2860 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; |
9c02b525 PA |
2861 | return 1; |
2862 | } | |
faf09f01 | 2863 | #endif |
d6b0e80f AC |
2864 | |
2865 | return 0; | |
2866 | } | |
2867 | ||
faf09f01 PA |
2868 | |
2869 | /* Returns true if the LWP had stopped for a software breakpoint. */ | |
2870 | ||
2871 | static int | |
2872 | linux_nat_stopped_by_sw_breakpoint (struct target_ops *ops) | |
2873 | { | |
2874 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2875 | ||
2876 | gdb_assert (lp != NULL); | |
2877 | ||
2878 | return lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2879 | } | |
2880 | ||
2881 | /* Implement the supports_stopped_by_sw_breakpoint method. */ | |
2882 | ||
2883 | static int | |
2884 | linux_nat_supports_stopped_by_sw_breakpoint (struct target_ops *ops) | |
2885 | { | |
2886 | return USE_SIGTRAP_SIGINFO; | |
2887 | } | |
2888 | ||
2889 | /* Returns true if the LWP had stopped for a hardware | |
2890 | breakpoint/watchpoint. */ | |
2891 | ||
2892 | static int | |
2893 | linux_nat_stopped_by_hw_breakpoint (struct target_ops *ops) | |
2894 | { | |
2895 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2896 | ||
2897 | gdb_assert (lp != NULL); | |
2898 | ||
2899 | return lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT; | |
2900 | } | |
2901 | ||
2902 | /* Implement the supports_stopped_by_hw_breakpoint method. */ | |
2903 | ||
2904 | static int | |
2905 | linux_nat_supports_stopped_by_hw_breakpoint (struct target_ops *ops) | |
2906 | { | |
2907 | return USE_SIGTRAP_SIGINFO; | |
2908 | } | |
2909 | ||
d6b0e80f AC |
2910 | /* Select one LWP out of those that have events pending. */ |
2911 | ||
2912 | static void | |
d90e17a7 | 2913 | select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
d6b0e80f AC |
2914 | { |
2915 | int num_events = 0; | |
2916 | int random_selector; | |
9c02b525 | 2917 | struct lwp_info *event_lp = NULL; |
d6b0e80f | 2918 | |
ac264b3b | 2919 | /* Record the wait status for the original LWP. */ |
d6b0e80f AC |
2920 | (*orig_lp)->status = *status; |
2921 | ||
9c02b525 PA |
2922 | /* In all-stop, give preference to the LWP that is being |
2923 | single-stepped. There will be at most one, and it will be the | |
2924 | LWP that the core is most interested in. If we didn't do this, | |
2925 | then we'd have to handle pending step SIGTRAPs somehow in case | |
2926 | the core later continues the previously-stepped thread, as | |
2927 | otherwise we'd report the pending SIGTRAP then, and the core, not | |
2928 | having stepped the thread, wouldn't understand what the trap was | |
2929 | for, and therefore would report it to the user as a random | |
2930 | signal. */ | |
2931 | if (!non_stop) | |
d6b0e80f | 2932 | { |
9c02b525 PA |
2933 | event_lp = iterate_over_lwps (filter, |
2934 | select_singlestep_lwp_callback, NULL); | |
2935 | if (event_lp != NULL) | |
2936 | { | |
2937 | if (debug_linux_nat) | |
2938 | fprintf_unfiltered (gdb_stdlog, | |
2939 | "SEL: Select single-step %s\n", | |
2940 | target_pid_to_str (event_lp->ptid)); | |
2941 | } | |
d6b0e80f | 2942 | } |
9c02b525 PA |
2943 | |
2944 | if (event_lp == NULL) | |
d6b0e80f | 2945 | { |
9c02b525 | 2946 | /* Pick one at random, out of those which have had events. */ |
d6b0e80f | 2947 | |
9c02b525 | 2948 | /* First see how many events we have. */ |
d90e17a7 | 2949 | iterate_over_lwps (filter, count_events_callback, &num_events); |
8bf3b159 | 2950 | gdb_assert (num_events > 0); |
d6b0e80f | 2951 | |
9c02b525 PA |
2952 | /* Now randomly pick a LWP out of those that have had |
2953 | events. */ | |
d6b0e80f AC |
2954 | random_selector = (int) |
2955 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
2956 | ||
2957 | if (debug_linux_nat && num_events > 1) | |
2958 | fprintf_unfiltered (gdb_stdlog, | |
9c02b525 | 2959 | "SEL: Found %d events, selecting #%d\n", |
d6b0e80f AC |
2960 | num_events, random_selector); |
2961 | ||
d90e17a7 PA |
2962 | event_lp = iterate_over_lwps (filter, |
2963 | select_event_lwp_callback, | |
d6b0e80f AC |
2964 | &random_selector); |
2965 | } | |
2966 | ||
2967 | if (event_lp != NULL) | |
2968 | { | |
2969 | /* Switch the event LWP. */ | |
2970 | *orig_lp = event_lp; | |
2971 | *status = event_lp->status; | |
2972 | } | |
2973 | ||
2974 | /* Flush the wait status for the event LWP. */ | |
2975 | (*orig_lp)->status = 0; | |
2976 | } | |
2977 | ||
2978 | /* Return non-zero if LP has been resumed. */ | |
2979 | ||
2980 | static int | |
2981 | resumed_callback (struct lwp_info *lp, void *data) | |
2982 | { | |
2983 | return lp->resumed; | |
2984 | } | |
2985 | ||
12d9289a PA |
2986 | /* Stop an active thread, verify it still exists, then resume it. If |
2987 | the thread ends up with a pending status, then it is not resumed, | |
2988 | and *DATA (really a pointer to int), is set. */ | |
d6b0e80f AC |
2989 | |
2990 | static int | |
2991 | stop_and_resume_callback (struct lwp_info *lp, void *data) | |
2992 | { | |
25289eb2 | 2993 | if (!lp->stopped) |
d6b0e80f | 2994 | { |
25289eb2 PA |
2995 | ptid_t ptid = lp->ptid; |
2996 | ||
d6b0e80f AC |
2997 | stop_callback (lp, NULL); |
2998 | stop_wait_callback (lp, NULL); | |
25289eb2 PA |
2999 | |
3000 | /* Resume if the lwp still exists, and the core wanted it | |
3001 | running. */ | |
12d9289a PA |
3002 | lp = find_lwp_pid (ptid); |
3003 | if (lp != NULL) | |
25289eb2 | 3004 | { |
12d9289a | 3005 | if (lp->last_resume_kind == resume_stop |
8a99810d | 3006 | && !lwp_status_pending_p (lp)) |
12d9289a PA |
3007 | { |
3008 | /* The core wanted the LWP to stop. Even if it stopped | |
3009 | cleanly (with SIGSTOP), leave the event pending. */ | |
3010 | if (debug_linux_nat) | |
3011 | fprintf_unfiltered (gdb_stdlog, | |
3012 | "SARC: core wanted LWP %ld stopped " | |
3013 | "(leaving SIGSTOP pending)\n", | |
dfd4cc63 | 3014 | ptid_get_lwp (lp->ptid)); |
12d9289a PA |
3015 | lp->status = W_STOPCODE (SIGSTOP); |
3016 | } | |
3017 | ||
8a99810d | 3018 | if (!lwp_status_pending_p (lp)) |
12d9289a PA |
3019 | { |
3020 | if (debug_linux_nat) | |
3021 | fprintf_unfiltered (gdb_stdlog, | |
3022 | "SARC: re-resuming LWP %ld\n", | |
dfd4cc63 | 3023 | ptid_get_lwp (lp->ptid)); |
e5ef252a | 3024 | resume_lwp (lp, lp->step, GDB_SIGNAL_0); |
12d9289a PA |
3025 | } |
3026 | else | |
3027 | { | |
3028 | if (debug_linux_nat) | |
3029 | fprintf_unfiltered (gdb_stdlog, | |
3030 | "SARC: not re-resuming LWP %ld " | |
3031 | "(has pending)\n", | |
dfd4cc63 | 3032 | ptid_get_lwp (lp->ptid)); |
12d9289a | 3033 | } |
25289eb2 | 3034 | } |
d6b0e80f AC |
3035 | } |
3036 | return 0; | |
3037 | } | |
3038 | ||
02f3fc28 | 3039 | /* Check if we should go on and pass this event to common code. |
9c02b525 | 3040 | Return the affected lwp if we are, or NULL otherwise. */ |
12d9289a | 3041 | |
02f3fc28 | 3042 | static struct lwp_info * |
9c02b525 | 3043 | linux_nat_filter_event (int lwpid, int status) |
02f3fc28 PA |
3044 | { |
3045 | struct lwp_info *lp; | |
89a5711c | 3046 | int event = linux_ptrace_get_extended_event (status); |
02f3fc28 PA |
3047 | |
3048 | lp = find_lwp_pid (pid_to_ptid (lwpid)); | |
3049 | ||
3050 | /* Check for stop events reported by a process we didn't already | |
3051 | know about - anything not already in our LWP list. | |
3052 | ||
3053 | If we're expecting to receive stopped processes after | |
3054 | fork, vfork, and clone events, then we'll just add the | |
3055 | new one to our list and go back to waiting for the event | |
3056 | to be reported - the stopped process might be returned | |
0e5bf2a8 PA |
3057 | from waitpid before or after the event is. |
3058 | ||
3059 | But note the case of a non-leader thread exec'ing after the | |
3060 | leader having exited, and gone from our lists. The non-leader | |
3061 | thread changes its tid to the tgid. */ | |
3062 | ||
3063 | if (WIFSTOPPED (status) && lp == NULL | |
89a5711c | 3064 | && (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC)) |
0e5bf2a8 PA |
3065 | { |
3066 | /* A multi-thread exec after we had seen the leader exiting. */ | |
3067 | if (debug_linux_nat) | |
3068 | fprintf_unfiltered (gdb_stdlog, | |
3069 | "LLW: Re-adding thread group leader LWP %d.\n", | |
3070 | lwpid); | |
3071 | ||
dfd4cc63 | 3072 | lp = add_lwp (ptid_build (lwpid, lwpid, 0)); |
0e5bf2a8 PA |
3073 | lp->stopped = 1; |
3074 | lp->resumed = 1; | |
3075 | add_thread (lp->ptid); | |
3076 | } | |
3077 | ||
02f3fc28 PA |
3078 | if (WIFSTOPPED (status) && !lp) |
3079 | { | |
3b27ef47 PA |
3080 | if (debug_linux_nat) |
3081 | fprintf_unfiltered (gdb_stdlog, | |
3082 | "LHEW: saving LWP %ld status %s in stopped_pids list\n", | |
3083 | (long) lwpid, status_to_str (status)); | |
84636d28 | 3084 | add_to_pid_list (&stopped_pids, lwpid, status); |
02f3fc28 PA |
3085 | return NULL; |
3086 | } | |
3087 | ||
3088 | /* Make sure we don't report an event for the exit of an LWP not in | |
1777feb0 | 3089 | our list, i.e. not part of the current process. This can happen |
fd62cb89 | 3090 | if we detach from a program we originally forked and then it |
02f3fc28 PA |
3091 | exits. */ |
3092 | if (!WIFSTOPPED (status) && !lp) | |
3093 | return NULL; | |
3094 | ||
8817a6f2 PA |
3095 | /* This LWP is stopped now. (And if dead, this prevents it from |
3096 | ever being continued.) */ | |
3097 | lp->stopped = 1; | |
3098 | ||
8784d563 PA |
3099 | if (WIFSTOPPED (status) && lp->must_set_ptrace_flags) |
3100 | { | |
3101 | struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid)); | |
3102 | ||
3103 | linux_enable_event_reporting (ptid_get_lwp (lp->ptid), inf->attach_flag); | |
3104 | lp->must_set_ptrace_flags = 0; | |
3105 | } | |
3106 | ||
ca2163eb PA |
3107 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
3108 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
3109 | { | |
3110 | /* No longer need the sysgood bit. The ptrace event ends up | |
3111 | recorded in lp->waitstatus if we care for it. We can carry | |
3112 | on handling the event like a regular SIGTRAP from here | |
3113 | on. */ | |
3114 | status = W_STOPCODE (SIGTRAP); | |
3115 | if (linux_handle_syscall_trap (lp, 0)) | |
3116 | return NULL; | |
3117 | } | |
02f3fc28 | 3118 | |
ca2163eb | 3119 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
3120 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
3121 | && linux_is_extended_waitstatus (status)) | |
02f3fc28 PA |
3122 | { |
3123 | if (debug_linux_nat) | |
3124 | fprintf_unfiltered (gdb_stdlog, | |
3125 | "LLW: Handling extended status 0x%06x\n", | |
3126 | status); | |
3127 | if (linux_handle_extended_wait (lp, status, 0)) | |
3128 | return NULL; | |
3129 | } | |
3130 | ||
3131 | /* Check if the thread has exited. */ | |
9c02b525 PA |
3132 | if (WIFEXITED (status) || WIFSIGNALED (status)) |
3133 | { | |
3134 | if (num_lwps (ptid_get_pid (lp->ptid)) > 1) | |
02f3fc28 | 3135 | { |
9c02b525 PA |
3136 | /* If this is the main thread, we must stop all threads and |
3137 | verify if they are still alive. This is because in the | |
3138 | nptl thread model on Linux 2.4, there is no signal issued | |
3139 | for exiting LWPs other than the main thread. We only get | |
3140 | the main thread exit signal once all child threads have | |
3141 | already exited. If we stop all the threads and use the | |
3142 | stop_wait_callback to check if they have exited we can | |
3143 | determine whether this signal should be ignored or | |
3144 | whether it means the end of the debugged application, | |
3145 | regardless of which threading model is being used. */ | |
3146 | if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid)) | |
3147 | { | |
3148 | iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp->ptid)), | |
3149 | stop_and_resume_callback, NULL); | |
3150 | } | |
3151 | ||
3152 | if (debug_linux_nat) | |
3153 | fprintf_unfiltered (gdb_stdlog, | |
3154 | "LLW: %s exited.\n", | |
3155 | target_pid_to_str (lp->ptid)); | |
3156 | ||
3157 | if (num_lwps (ptid_get_pid (lp->ptid)) > 1) | |
3158 | { | |
3159 | /* If there is at least one more LWP, then the exit signal | |
3160 | was not the end of the debugged application and should be | |
3161 | ignored. */ | |
3162 | exit_lwp (lp); | |
3163 | return NULL; | |
3164 | } | |
02f3fc28 PA |
3165 | } |
3166 | ||
9c02b525 PA |
3167 | gdb_assert (lp->resumed); |
3168 | ||
02f3fc28 PA |
3169 | if (debug_linux_nat) |
3170 | fprintf_unfiltered (gdb_stdlog, | |
9c02b525 PA |
3171 | "Process %ld exited\n", |
3172 | ptid_get_lwp (lp->ptid)); | |
02f3fc28 | 3173 | |
9c02b525 PA |
3174 | /* This was the last lwp in the process. Since events are |
3175 | serialized to GDB core, we may not be able report this one | |
3176 | right now, but GDB core and the other target layers will want | |
3177 | to be notified about the exit code/signal, leave the status | |
3178 | pending for the next time we're able to report it. */ | |
3179 | ||
3180 | /* Dead LWP's aren't expected to reported a pending sigstop. */ | |
3181 | lp->signalled = 0; | |
3182 | ||
3183 | /* Store the pending event in the waitstatus, because | |
3184 | W_EXITCODE(0,0) == 0. */ | |
3185 | store_waitstatus (&lp->waitstatus, status); | |
3186 | return lp; | |
02f3fc28 PA |
3187 | } |
3188 | ||
3189 | /* Check if the current LWP has previously exited. In the nptl | |
3190 | thread model, LWPs other than the main thread do not issue | |
3191 | signals when they exit so we must check whenever the thread has | |
3192 | stopped. A similar check is made in stop_wait_callback(). */ | |
dfd4cc63 | 3193 | if (num_lwps (ptid_get_pid (lp->ptid)) > 1 && !linux_thread_alive (lp->ptid)) |
02f3fc28 | 3194 | { |
dfd4cc63 | 3195 | ptid_t ptid = pid_to_ptid (ptid_get_pid (lp->ptid)); |
d90e17a7 | 3196 | |
02f3fc28 PA |
3197 | if (debug_linux_nat) |
3198 | fprintf_unfiltered (gdb_stdlog, | |
3199 | "LLW: %s exited.\n", | |
3200 | target_pid_to_str (lp->ptid)); | |
3201 | ||
3202 | exit_lwp (lp); | |
3203 | ||
3204 | /* Make sure there is at least one thread running. */ | |
d90e17a7 | 3205 | gdb_assert (iterate_over_lwps (ptid, running_callback, NULL)); |
02f3fc28 PA |
3206 | |
3207 | /* Discard the event. */ | |
3208 | return NULL; | |
3209 | } | |
3210 | ||
3211 | /* Make sure we don't report a SIGSTOP that we sent ourselves in | |
3212 | an attempt to stop an LWP. */ | |
3213 | if (lp->signalled | |
3214 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) | |
3215 | { | |
02f3fc28 PA |
3216 | lp->signalled = 0; |
3217 | ||
2bf6fb9d | 3218 | if (lp->last_resume_kind == resume_stop) |
25289eb2 | 3219 | { |
2bf6fb9d PA |
3220 | if (debug_linux_nat) |
3221 | fprintf_unfiltered (gdb_stdlog, | |
3222 | "LLW: resume_stop SIGSTOP caught for %s.\n", | |
3223 | target_pid_to_str (lp->ptid)); | |
3224 | } | |
3225 | else | |
3226 | { | |
3227 | /* This is a delayed SIGSTOP. Filter out the event. */ | |
02f3fc28 | 3228 | |
25289eb2 PA |
3229 | if (debug_linux_nat) |
3230 | fprintf_unfiltered (gdb_stdlog, | |
2bf6fb9d | 3231 | "LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n", |
25289eb2 PA |
3232 | lp->step ? |
3233 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3234 | target_pid_to_str (lp->ptid)); | |
02f3fc28 | 3235 | |
2bf6fb9d | 3236 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
25289eb2 | 3237 | gdb_assert (lp->resumed); |
25289eb2 PA |
3238 | return NULL; |
3239 | } | |
02f3fc28 PA |
3240 | } |
3241 | ||
57380f4e DJ |
3242 | /* Make sure we don't report a SIGINT that we have already displayed |
3243 | for another thread. */ | |
3244 | if (lp->ignore_sigint | |
3245 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) | |
3246 | { | |
3247 | if (debug_linux_nat) | |
3248 | fprintf_unfiltered (gdb_stdlog, | |
3249 | "LLW: Delayed SIGINT caught for %s.\n", | |
3250 | target_pid_to_str (lp->ptid)); | |
3251 | ||
3252 | /* This is a delayed SIGINT. */ | |
3253 | lp->ignore_sigint = 0; | |
3254 | ||
8a99810d | 3255 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
57380f4e DJ |
3256 | if (debug_linux_nat) |
3257 | fprintf_unfiltered (gdb_stdlog, | |
3258 | "LLW: %s %s, 0, 0 (discard SIGINT)\n", | |
3259 | lp->step ? | |
3260 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3261 | target_pid_to_str (lp->ptid)); | |
57380f4e DJ |
3262 | gdb_assert (lp->resumed); |
3263 | ||
3264 | /* Discard the event. */ | |
3265 | return NULL; | |
3266 | } | |
3267 | ||
9c02b525 PA |
3268 | /* Don't report signals that GDB isn't interested in, such as |
3269 | signals that are neither printed nor stopped upon. Stopping all | |
3270 | threads can be a bit time-consuming so if we want decent | |
3271 | performance with heavily multi-threaded programs, especially when | |
3272 | they're using a high frequency timer, we'd better avoid it if we | |
3273 | can. */ | |
3274 | if (WIFSTOPPED (status)) | |
3275 | { | |
3276 | enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status)); | |
3277 | ||
3278 | if (!non_stop) | |
3279 | { | |
3280 | /* Only do the below in all-stop, as we currently use SIGSTOP | |
3281 | to implement target_stop (see linux_nat_stop) in | |
3282 | non-stop. */ | |
3283 | if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0) | |
3284 | { | |
3285 | /* If ^C/BREAK is typed at the tty/console, SIGINT gets | |
3286 | forwarded to the entire process group, that is, all LWPs | |
3287 | will receive it - unless they're using CLONE_THREAD to | |
3288 | share signals. Since we only want to report it once, we | |
3289 | mark it as ignored for all LWPs except this one. */ | |
3290 | iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp->ptid)), | |
3291 | set_ignore_sigint, NULL); | |
3292 | lp->ignore_sigint = 0; | |
3293 | } | |
3294 | else | |
3295 | maybe_clear_ignore_sigint (lp); | |
3296 | } | |
3297 | ||
3298 | /* When using hardware single-step, we need to report every signal. | |
c9587f88 AT |
3299 | Otherwise, signals in pass_mask may be short-circuited |
3300 | except signals that might be caused by a breakpoint. */ | |
9c02b525 | 3301 | if (!lp->step |
c9587f88 AT |
3302 | && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status)) |
3303 | && !linux_wstatus_maybe_breakpoint (status)) | |
9c02b525 PA |
3304 | { |
3305 | linux_resume_one_lwp (lp, lp->step, signo); | |
3306 | if (debug_linux_nat) | |
3307 | fprintf_unfiltered (gdb_stdlog, | |
3308 | "LLW: %s %s, %s (preempt 'handle')\n", | |
3309 | lp->step ? | |
3310 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3311 | target_pid_to_str (lp->ptid), | |
3312 | (signo != GDB_SIGNAL_0 | |
3313 | ? strsignal (gdb_signal_to_host (signo)) | |
3314 | : "0")); | |
3315 | return NULL; | |
3316 | } | |
3317 | } | |
3318 | ||
02f3fc28 PA |
3319 | /* An interesting event. */ |
3320 | gdb_assert (lp); | |
ca2163eb | 3321 | lp->status = status; |
9c02b525 | 3322 | save_sigtrap (lp); |
02f3fc28 PA |
3323 | return lp; |
3324 | } | |
3325 | ||
0e5bf2a8 PA |
3326 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
3327 | their exits until all other threads in the group have exited. */ | |
3328 | ||
3329 | static void | |
3330 | check_zombie_leaders (void) | |
3331 | { | |
3332 | struct inferior *inf; | |
3333 | ||
3334 | ALL_INFERIORS (inf) | |
3335 | { | |
3336 | struct lwp_info *leader_lp; | |
3337 | ||
3338 | if (inf->pid == 0) | |
3339 | continue; | |
3340 | ||
3341 | leader_lp = find_lwp_pid (pid_to_ptid (inf->pid)); | |
3342 | if (leader_lp != NULL | |
3343 | /* Check if there are other threads in the group, as we may | |
3344 | have raced with the inferior simply exiting. */ | |
3345 | && num_lwps (inf->pid) > 1 | |
5f572dec | 3346 | && linux_proc_pid_is_zombie (inf->pid)) |
0e5bf2a8 PA |
3347 | { |
3348 | if (debug_linux_nat) | |
3349 | fprintf_unfiltered (gdb_stdlog, | |
3350 | "CZL: Thread group leader %d zombie " | |
3351 | "(it exited, or another thread execd).\n", | |
3352 | inf->pid); | |
3353 | ||
3354 | /* A leader zombie can mean one of two things: | |
3355 | ||
3356 | - It exited, and there's an exit status pending | |
3357 | available, or only the leader exited (not the whole | |
3358 | program). In the latter case, we can't waitpid the | |
3359 | leader's exit status until all other threads are gone. | |
3360 | ||
3361 | - There are 3 or more threads in the group, and a thread | |
3362 | other than the leader exec'd. On an exec, the Linux | |
3363 | kernel destroys all other threads (except the execing | |
3364 | one) in the thread group, and resets the execing thread's | |
3365 | tid to the tgid. No exit notification is sent for the | |
3366 | execing thread -- from the ptracer's perspective, it | |
3367 | appears as though the execing thread just vanishes. | |
3368 | Until we reap all other threads except the leader and the | |
3369 | execing thread, the leader will be zombie, and the | |
3370 | execing thread will be in `D (disc sleep)'. As soon as | |
3371 | all other threads are reaped, the execing thread changes | |
3372 | it's tid to the tgid, and the previous (zombie) leader | |
3373 | vanishes, giving place to the "new" leader. We could try | |
3374 | distinguishing the exit and exec cases, by waiting once | |
3375 | more, and seeing if something comes out, but it doesn't | |
3376 | sound useful. The previous leader _does_ go away, and | |
3377 | we'll re-add the new one once we see the exec event | |
3378 | (which is just the same as what would happen if the | |
3379 | previous leader did exit voluntarily before some other | |
3380 | thread execs). */ | |
3381 | ||
3382 | if (debug_linux_nat) | |
3383 | fprintf_unfiltered (gdb_stdlog, | |
3384 | "CZL: Thread group leader %d vanished.\n", | |
3385 | inf->pid); | |
3386 | exit_lwp (leader_lp); | |
3387 | } | |
3388 | } | |
3389 | } | |
3390 | ||
d6b0e80f | 3391 | static ptid_t |
7feb7d06 | 3392 | linux_nat_wait_1 (struct target_ops *ops, |
47608cb1 PA |
3393 | ptid_t ptid, struct target_waitstatus *ourstatus, |
3394 | int target_options) | |
d6b0e80f | 3395 | { |
fc9b8e47 | 3396 | sigset_t prev_mask; |
4b60df3d | 3397 | enum resume_kind last_resume_kind; |
12d9289a | 3398 | struct lwp_info *lp; |
12d9289a | 3399 | int status; |
d6b0e80f | 3400 | |
01124a23 | 3401 | if (debug_linux_nat) |
b84876c2 PA |
3402 | fprintf_unfiltered (gdb_stdlog, "LLW: enter\n"); |
3403 | ||
f973ed9c DJ |
3404 | /* The first time we get here after starting a new inferior, we may |
3405 | not have added it to the LWP list yet - this is the earliest | |
3406 | moment at which we know its PID. */ | |
d90e17a7 | 3407 | if (ptid_is_pid (inferior_ptid)) |
f973ed9c | 3408 | { |
27c9d204 PA |
3409 | /* Upgrade the main thread's ptid. */ |
3410 | thread_change_ptid (inferior_ptid, | |
dfd4cc63 LM |
3411 | ptid_build (ptid_get_pid (inferior_ptid), |
3412 | ptid_get_pid (inferior_ptid), 0)); | |
27c9d204 | 3413 | |
26cb8b7c | 3414 | lp = add_initial_lwp (inferior_ptid); |
f973ed9c DJ |
3415 | lp->resumed = 1; |
3416 | } | |
3417 | ||
12696c10 | 3418 | /* Make sure SIGCHLD is blocked until the sigsuspend below. */ |
7feb7d06 | 3419 | block_child_signals (&prev_mask); |
d6b0e80f | 3420 | |
d6b0e80f | 3421 | /* First check if there is a LWP with a wait status pending. */ |
8a99810d PA |
3422 | lp = iterate_over_lwps (ptid, status_callback, NULL); |
3423 | if (lp != NULL) | |
d6b0e80f AC |
3424 | { |
3425 | if (debug_linux_nat) | |
d6b0e80f AC |
3426 | fprintf_unfiltered (gdb_stdlog, |
3427 | "LLW: Using pending wait status %s for %s.\n", | |
ca2163eb | 3428 | status_to_str (lp->status), |
d6b0e80f | 3429 | target_pid_to_str (lp->ptid)); |
d6b0e80f AC |
3430 | } |
3431 | ||
d9d41e78 | 3432 | if (!target_is_async_p ()) |
b84876c2 PA |
3433 | { |
3434 | /* Causes SIGINT to be passed on to the attached process. */ | |
3435 | set_sigint_trap (); | |
b84876c2 | 3436 | } |
d6b0e80f | 3437 | |
9c02b525 PA |
3438 | /* But if we don't find a pending event, we'll have to wait. Always |
3439 | pull all events out of the kernel. We'll randomly select an | |
3440 | event LWP out of all that have events, to prevent starvation. */ | |
7feb7d06 | 3441 | |
d90e17a7 | 3442 | while (lp == NULL) |
d6b0e80f AC |
3443 | { |
3444 | pid_t lwpid; | |
3445 | ||
0e5bf2a8 PA |
3446 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
3447 | quirks: | |
3448 | ||
3449 | - If the thread group leader exits while other threads in the | |
3450 | thread group still exist, waitpid(TGID, ...) hangs. That | |
3451 | waitpid won't return an exit status until the other threads | |
3452 | in the group are reapped. | |
3453 | ||
3454 | - When a non-leader thread execs, that thread just vanishes | |
3455 | without reporting an exit (so we'd hang if we waited for it | |
3456 | explicitly in that case). The exec event is reported to | |
3457 | the TGID pid. */ | |
3458 | ||
3459 | errno = 0; | |
3460 | lwpid = my_waitpid (-1, &status, __WCLONE | WNOHANG); | |
3461 | if (lwpid == 0 || (lwpid == -1 && errno == ECHILD)) | |
3462 | lwpid = my_waitpid (-1, &status, WNOHANG); | |
3463 | ||
3464 | if (debug_linux_nat) | |
3465 | fprintf_unfiltered (gdb_stdlog, | |
3466 | "LNW: waitpid(-1, ...) returned %d, %s\n", | |
3467 | lwpid, errno ? safe_strerror (errno) : "ERRNO-OK"); | |
b84876c2 | 3468 | |
d6b0e80f AC |
3469 | if (lwpid > 0) |
3470 | { | |
d6b0e80f AC |
3471 | if (debug_linux_nat) |
3472 | { | |
3473 | fprintf_unfiltered (gdb_stdlog, | |
3474 | "LLW: waitpid %ld received %s\n", | |
3475 | (long) lwpid, status_to_str (status)); | |
3476 | } | |
3477 | ||
9c02b525 | 3478 | linux_nat_filter_event (lwpid, status); |
0e5bf2a8 PA |
3479 | /* Retry until nothing comes out of waitpid. A single |
3480 | SIGCHLD can indicate more than one child stopped. */ | |
3481 | continue; | |
d6b0e80f AC |
3482 | } |
3483 | ||
20ba1ce6 PA |
3484 | /* Now that we've pulled all events out of the kernel, resume |
3485 | LWPs that don't have an interesting event to report. */ | |
3486 | iterate_over_lwps (minus_one_ptid, | |
3487 | resume_stopped_resumed_lwps, &minus_one_ptid); | |
3488 | ||
3489 | /* ... and find an LWP with a status to report to the core, if | |
3490 | any. */ | |
9c02b525 PA |
3491 | lp = iterate_over_lwps (ptid, status_callback, NULL); |
3492 | if (lp != NULL) | |
3493 | break; | |
3494 | ||
0e5bf2a8 PA |
3495 | /* Check for zombie thread group leaders. Those can't be reaped |
3496 | until all other threads in the thread group are. */ | |
3497 | check_zombie_leaders (); | |
d6b0e80f | 3498 | |
0e5bf2a8 PA |
3499 | /* If there are no resumed children left, bail. We'd be stuck |
3500 | forever in the sigsuspend call below otherwise. */ | |
3501 | if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL) | |
3502 | { | |
3503 | if (debug_linux_nat) | |
3504 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n"); | |
b84876c2 | 3505 | |
0e5bf2a8 | 3506 | ourstatus->kind = TARGET_WAITKIND_NO_RESUMED; |
b84876c2 | 3507 | |
d9d41e78 | 3508 | if (!target_is_async_p ()) |
0e5bf2a8 | 3509 | clear_sigint_trap (); |
b84876c2 | 3510 | |
0e5bf2a8 PA |
3511 | restore_child_signals_mask (&prev_mask); |
3512 | return minus_one_ptid; | |
d6b0e80f | 3513 | } |
28736962 | 3514 | |
0e5bf2a8 PA |
3515 | /* No interesting event to report to the core. */ |
3516 | ||
3517 | if (target_options & TARGET_WNOHANG) | |
3518 | { | |
01124a23 | 3519 | if (debug_linux_nat) |
28736962 PA |
3520 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n"); |
3521 | ||
0e5bf2a8 | 3522 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
28736962 PA |
3523 | restore_child_signals_mask (&prev_mask); |
3524 | return minus_one_ptid; | |
3525 | } | |
d6b0e80f AC |
3526 | |
3527 | /* We shouldn't end up here unless we want to try again. */ | |
d90e17a7 | 3528 | gdb_assert (lp == NULL); |
0e5bf2a8 PA |
3529 | |
3530 | /* Block until we get an event reported with SIGCHLD. */ | |
d36bf488 DE |
3531 | if (debug_linux_nat) |
3532 | fprintf_unfiltered (gdb_stdlog, "LNW: about to sigsuspend\n"); | |
0e5bf2a8 | 3533 | sigsuspend (&suspend_mask); |
d6b0e80f AC |
3534 | } |
3535 | ||
d9d41e78 | 3536 | if (!target_is_async_p ()) |
d26b5354 | 3537 | clear_sigint_trap (); |
d6b0e80f AC |
3538 | |
3539 | gdb_assert (lp); | |
3540 | ||
ca2163eb PA |
3541 | status = lp->status; |
3542 | lp->status = 0; | |
3543 | ||
4c28f408 PA |
3544 | if (!non_stop) |
3545 | { | |
3546 | /* Now stop all other LWP's ... */ | |
d90e17a7 | 3547 | iterate_over_lwps (minus_one_ptid, stop_callback, NULL); |
4c28f408 PA |
3548 | |
3549 | /* ... and wait until all of them have reported back that | |
3550 | they're no longer running. */ | |
d90e17a7 | 3551 | iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL); |
9c02b525 PA |
3552 | } |
3553 | ||
3554 | /* If we're not waiting for a specific LWP, choose an event LWP from | |
3555 | among those that have had events. Giving equal priority to all | |
3556 | LWPs that have had events helps prevent starvation. */ | |
3557 | if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) | |
3558 | select_event_lwp (ptid, &lp, &status); | |
3559 | ||
3560 | gdb_assert (lp != NULL); | |
3561 | ||
3562 | /* Now that we've selected our final event LWP, un-adjust its PC if | |
faf09f01 PA |
3563 | it was a software breakpoint, and we can't reliably support the |
3564 | "stopped by software breakpoint" stop reason. */ | |
3565 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT | |
3566 | && !USE_SIGTRAP_SIGINFO) | |
9c02b525 PA |
3567 | { |
3568 | struct regcache *regcache = get_thread_regcache (lp->ptid); | |
3569 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
527a273a | 3570 | int decr_pc = gdbarch_decr_pc_after_break (gdbarch); |
4c28f408 | 3571 | |
9c02b525 PA |
3572 | if (decr_pc != 0) |
3573 | { | |
3574 | CORE_ADDR pc; | |
d6b0e80f | 3575 | |
9c02b525 PA |
3576 | pc = regcache_read_pc (regcache); |
3577 | regcache_write_pc (regcache, pc + decr_pc); | |
3578 | } | |
3579 | } | |
e3e9f5a2 | 3580 | |
9c02b525 PA |
3581 | /* We'll need this to determine whether to report a SIGSTOP as |
3582 | GDB_SIGNAL_0. Need to take a copy because resume_clear_callback | |
3583 | clears it. */ | |
3584 | last_resume_kind = lp->last_resume_kind; | |
4b60df3d | 3585 | |
9c02b525 PA |
3586 | if (!non_stop) |
3587 | { | |
e3e9f5a2 PA |
3588 | /* In all-stop, from the core's perspective, all LWPs are now |
3589 | stopped until a new resume action is sent over. */ | |
3590 | iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL); | |
3591 | } | |
3592 | else | |
25289eb2 | 3593 | { |
4b60df3d | 3594 | resume_clear_callback (lp, NULL); |
25289eb2 | 3595 | } |
d6b0e80f | 3596 | |
26ab7092 | 3597 | if (linux_nat_status_is_event (status)) |
d6b0e80f | 3598 | { |
d6b0e80f AC |
3599 | if (debug_linux_nat) |
3600 | fprintf_unfiltered (gdb_stdlog, | |
4fdebdd0 PA |
3601 | "LLW: trap ptid is %s.\n", |
3602 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 3603 | } |
d6b0e80f AC |
3604 | |
3605 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
3606 | { | |
3607 | *ourstatus = lp->waitstatus; | |
3608 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
3609 | } | |
3610 | else | |
3611 | store_waitstatus (ourstatus, status); | |
3612 | ||
01124a23 | 3613 | if (debug_linux_nat) |
b84876c2 PA |
3614 | fprintf_unfiltered (gdb_stdlog, "LLW: exit\n"); |
3615 | ||
7feb7d06 | 3616 | restore_child_signals_mask (&prev_mask); |
1e225492 | 3617 | |
4b60df3d | 3618 | if (last_resume_kind == resume_stop |
25289eb2 PA |
3619 | && ourstatus->kind == TARGET_WAITKIND_STOPPED |
3620 | && WSTOPSIG (status) == SIGSTOP) | |
3621 | { | |
3622 | /* A thread that has been requested to stop by GDB with | |
3623 | target_stop, and it stopped cleanly, so report as SIG0. The | |
3624 | use of SIGSTOP is an implementation detail. */ | |
a493e3e2 | 3625 | ourstatus->value.sig = GDB_SIGNAL_0; |
25289eb2 PA |
3626 | } |
3627 | ||
1e225492 JK |
3628 | if (ourstatus->kind == TARGET_WAITKIND_EXITED |
3629 | || ourstatus->kind == TARGET_WAITKIND_SIGNALLED) | |
3630 | lp->core = -1; | |
3631 | else | |
2e794194 | 3632 | lp->core = linux_common_core_of_thread (lp->ptid); |
1e225492 | 3633 | |
f973ed9c | 3634 | return lp->ptid; |
d6b0e80f AC |
3635 | } |
3636 | ||
e3e9f5a2 PA |
3637 | /* Resume LWPs that are currently stopped without any pending status |
3638 | to report, but are resumed from the core's perspective. */ | |
3639 | ||
3640 | static int | |
3641 | resume_stopped_resumed_lwps (struct lwp_info *lp, void *data) | |
3642 | { | |
3643 | ptid_t *wait_ptid_p = data; | |
3644 | ||
3645 | if (lp->stopped | |
3646 | && lp->resumed | |
8a99810d | 3647 | && !lwp_status_pending_p (lp)) |
e3e9f5a2 | 3648 | { |
336060f3 PA |
3649 | struct regcache *regcache = get_thread_regcache (lp->ptid); |
3650 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
336060f3 | 3651 | |
23f238d3 | 3652 | TRY |
e3e9f5a2 | 3653 | { |
23f238d3 PA |
3654 | CORE_ADDR pc = regcache_read_pc (regcache); |
3655 | int leave_stopped = 0; | |
e3e9f5a2 | 3656 | |
23f238d3 PA |
3657 | /* Don't bother if there's a breakpoint at PC that we'd hit |
3658 | immediately, and we're not waiting for this LWP. */ | |
3659 | if (!ptid_match (lp->ptid, *wait_ptid_p)) | |
3660 | { | |
3661 | if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) | |
3662 | leave_stopped = 1; | |
3663 | } | |
e3e9f5a2 | 3664 | |
23f238d3 PA |
3665 | if (!leave_stopped) |
3666 | { | |
3667 | if (debug_linux_nat) | |
3668 | fprintf_unfiltered (gdb_stdlog, | |
3669 | "RSRL: resuming stopped-resumed LWP %s at " | |
3670 | "%s: step=%d\n", | |
3671 | target_pid_to_str (lp->ptid), | |
3672 | paddress (gdbarch, pc), | |
3673 | lp->step); | |
3674 | ||
3675 | linux_resume_one_lwp_throw (lp, lp->step, GDB_SIGNAL_0); | |
3676 | } | |
3677 | } | |
3678 | CATCH (ex, RETURN_MASK_ERROR) | |
3679 | { | |
3680 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
3681 | throw_exception (ex); | |
3682 | } | |
3683 | END_CATCH | |
e3e9f5a2 PA |
3684 | } |
3685 | ||
3686 | return 0; | |
3687 | } | |
3688 | ||
7feb7d06 PA |
3689 | static ptid_t |
3690 | linux_nat_wait (struct target_ops *ops, | |
47608cb1 PA |
3691 | ptid_t ptid, struct target_waitstatus *ourstatus, |
3692 | int target_options) | |
7feb7d06 PA |
3693 | { |
3694 | ptid_t event_ptid; | |
3695 | ||
3696 | if (debug_linux_nat) | |
09826ec5 PA |
3697 | { |
3698 | char *options_string; | |
3699 | ||
3700 | options_string = target_options_to_string (target_options); | |
3701 | fprintf_unfiltered (gdb_stdlog, | |
3702 | "linux_nat_wait: [%s], [%s]\n", | |
3703 | target_pid_to_str (ptid), | |
3704 | options_string); | |
3705 | xfree (options_string); | |
3706 | } | |
7feb7d06 PA |
3707 | |
3708 | /* Flush the async file first. */ | |
d9d41e78 | 3709 | if (target_is_async_p ()) |
7feb7d06 PA |
3710 | async_file_flush (); |
3711 | ||
e3e9f5a2 PA |
3712 | /* Resume LWPs that are currently stopped without any pending status |
3713 | to report, but are resumed from the core's perspective. LWPs get | |
3714 | in this state if we find them stopping at a time we're not | |
3715 | interested in reporting the event (target_wait on a | |
3716 | specific_process, for example, see linux_nat_wait_1), and | |
3717 | meanwhile the event became uninteresting. Don't bother resuming | |
3718 | LWPs we're not going to wait for if they'd stop immediately. */ | |
3719 | if (non_stop) | |
3720 | iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid); | |
3721 | ||
47608cb1 | 3722 | event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options); |
7feb7d06 PA |
3723 | |
3724 | /* If we requested any event, and something came out, assume there | |
3725 | may be more. If we requested a specific lwp or process, also | |
3726 | assume there may be more. */ | |
d9d41e78 | 3727 | if (target_is_async_p () |
6953d224 PA |
3728 | && ((ourstatus->kind != TARGET_WAITKIND_IGNORE |
3729 | && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED) | |
7feb7d06 PA |
3730 | || !ptid_equal (ptid, minus_one_ptid))) |
3731 | async_file_mark (); | |
3732 | ||
7feb7d06 PA |
3733 | return event_ptid; |
3734 | } | |
3735 | ||
d6b0e80f AC |
3736 | static int |
3737 | kill_callback (struct lwp_info *lp, void *data) | |
3738 | { | |
ed731959 JK |
3739 | /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
3740 | ||
3741 | errno = 0; | |
69ff6be5 | 3742 | kill_lwp (ptid_get_lwp (lp->ptid), SIGKILL); |
ed731959 | 3743 | if (debug_linux_nat) |
57745c90 PA |
3744 | { |
3745 | int save_errno = errno; | |
3746 | ||
3747 | fprintf_unfiltered (gdb_stdlog, | |
3748 | "KC: kill (SIGKILL) %s, 0, 0 (%s)\n", | |
3749 | target_pid_to_str (lp->ptid), | |
3750 | save_errno ? safe_strerror (save_errno) : "OK"); | |
3751 | } | |
ed731959 JK |
3752 | |
3753 | /* Some kernels ignore even SIGKILL for processes under ptrace. */ | |
3754 | ||
d6b0e80f | 3755 | errno = 0; |
dfd4cc63 | 3756 | ptrace (PTRACE_KILL, ptid_get_lwp (lp->ptid), 0, 0); |
d6b0e80f | 3757 | if (debug_linux_nat) |
57745c90 PA |
3758 | { |
3759 | int save_errno = errno; | |
3760 | ||
3761 | fprintf_unfiltered (gdb_stdlog, | |
3762 | "KC: PTRACE_KILL %s, 0, 0 (%s)\n", | |
3763 | target_pid_to_str (lp->ptid), | |
3764 | save_errno ? safe_strerror (save_errno) : "OK"); | |
3765 | } | |
d6b0e80f AC |
3766 | |
3767 | return 0; | |
3768 | } | |
3769 | ||
3770 | static int | |
3771 | kill_wait_callback (struct lwp_info *lp, void *data) | |
3772 | { | |
3773 | pid_t pid; | |
3774 | ||
3775 | /* We must make sure that there are no pending events (delayed | |
3776 | SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current | |
3777 | program doesn't interfere with any following debugging session. */ | |
3778 | ||
3779 | /* For cloned processes we must check both with __WCLONE and | |
3780 | without, since the exit status of a cloned process isn't reported | |
3781 | with __WCLONE. */ | |
3782 | if (lp->cloned) | |
3783 | { | |
3784 | do | |
3785 | { | |
dfd4cc63 | 3786 | pid = my_waitpid (ptid_get_lwp (lp->ptid), NULL, __WCLONE); |
e85a822c | 3787 | if (pid != (pid_t) -1) |
d6b0e80f | 3788 | { |
e85a822c DJ |
3789 | if (debug_linux_nat) |
3790 | fprintf_unfiltered (gdb_stdlog, | |
3791 | "KWC: wait %s received unknown.\n", | |
3792 | target_pid_to_str (lp->ptid)); | |
3793 | /* The Linux kernel sometimes fails to kill a thread | |
3794 | completely after PTRACE_KILL; that goes from the stop | |
3795 | point in do_fork out to the one in | |
3796 | get_signal_to_deliever and waits again. So kill it | |
3797 | again. */ | |
3798 | kill_callback (lp, NULL); | |
d6b0e80f AC |
3799 | } |
3800 | } | |
dfd4cc63 | 3801 | while (pid == ptid_get_lwp (lp->ptid)); |
d6b0e80f AC |
3802 | |
3803 | gdb_assert (pid == -1 && errno == ECHILD); | |
3804 | } | |
3805 | ||
3806 | do | |
3807 | { | |
dfd4cc63 | 3808 | pid = my_waitpid (ptid_get_lwp (lp->ptid), NULL, 0); |
e85a822c | 3809 | if (pid != (pid_t) -1) |
d6b0e80f | 3810 | { |
e85a822c DJ |
3811 | if (debug_linux_nat) |
3812 | fprintf_unfiltered (gdb_stdlog, | |
3813 | "KWC: wait %s received unk.\n", | |
3814 | target_pid_to_str (lp->ptid)); | |
3815 | /* See the call to kill_callback above. */ | |
3816 | kill_callback (lp, NULL); | |
d6b0e80f AC |
3817 | } |
3818 | } | |
dfd4cc63 | 3819 | while (pid == ptid_get_lwp (lp->ptid)); |
d6b0e80f AC |
3820 | |
3821 | gdb_assert (pid == -1 && errno == ECHILD); | |
3822 | return 0; | |
3823 | } | |
3824 | ||
3825 | static void | |
7d85a9c0 | 3826 | linux_nat_kill (struct target_ops *ops) |
d6b0e80f | 3827 | { |
f973ed9c DJ |
3828 | struct target_waitstatus last; |
3829 | ptid_t last_ptid; | |
3830 | int status; | |
d6b0e80f | 3831 | |
f973ed9c DJ |
3832 | /* If we're stopped while forking and we haven't followed yet, |
3833 | kill the other task. We need to do this first because the | |
3834 | parent will be sleeping if this is a vfork. */ | |
d6b0e80f | 3835 | |
f973ed9c | 3836 | get_last_target_status (&last_ptid, &last); |
d6b0e80f | 3837 | |
f973ed9c DJ |
3838 | if (last.kind == TARGET_WAITKIND_FORKED |
3839 | || last.kind == TARGET_WAITKIND_VFORKED) | |
3840 | { | |
dfd4cc63 | 3841 | ptrace (PT_KILL, ptid_get_pid (last.value.related_pid), 0, 0); |
f973ed9c | 3842 | wait (&status); |
26cb8b7c PA |
3843 | |
3844 | /* Let the arch-specific native code know this process is | |
3845 | gone. */ | |
dfd4cc63 | 3846 | linux_nat_forget_process (ptid_get_pid (last.value.related_pid)); |
f973ed9c DJ |
3847 | } |
3848 | ||
3849 | if (forks_exist_p ()) | |
7feb7d06 | 3850 | linux_fork_killall (); |
f973ed9c DJ |
3851 | else |
3852 | { | |
d90e17a7 | 3853 | ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid)); |
e0881a8e | 3854 | |
4c28f408 PA |
3855 | /* Stop all threads before killing them, since ptrace requires |
3856 | that the thread is stopped to sucessfully PTRACE_KILL. */ | |
d90e17a7 | 3857 | iterate_over_lwps (ptid, stop_callback, NULL); |
4c28f408 PA |
3858 | /* ... and wait until all of them have reported back that |
3859 | they're no longer running. */ | |
d90e17a7 | 3860 | iterate_over_lwps (ptid, stop_wait_callback, NULL); |
4c28f408 | 3861 | |
f973ed9c | 3862 | /* Kill all LWP's ... */ |
d90e17a7 | 3863 | iterate_over_lwps (ptid, kill_callback, NULL); |
f973ed9c DJ |
3864 | |
3865 | /* ... and wait until we've flushed all events. */ | |
d90e17a7 | 3866 | iterate_over_lwps (ptid, kill_wait_callback, NULL); |
f973ed9c DJ |
3867 | } |
3868 | ||
3869 | target_mourn_inferior (); | |
d6b0e80f AC |
3870 | } |
3871 | ||
3872 | static void | |
136d6dae | 3873 | linux_nat_mourn_inferior (struct target_ops *ops) |
d6b0e80f | 3874 | { |
26cb8b7c PA |
3875 | int pid = ptid_get_pid (inferior_ptid); |
3876 | ||
3877 | purge_lwp_list (pid); | |
d6b0e80f | 3878 | |
f973ed9c | 3879 | if (! forks_exist_p ()) |
d90e17a7 PA |
3880 | /* Normal case, no other forks available. */ |
3881 | linux_ops->to_mourn_inferior (ops); | |
f973ed9c DJ |
3882 | else |
3883 | /* Multi-fork case. The current inferior_ptid has exited, but | |
3884 | there are other viable forks to debug. Delete the exiting | |
3885 | one and context-switch to the first available. */ | |
3886 | linux_fork_mourn_inferior (); | |
26cb8b7c PA |
3887 | |
3888 | /* Let the arch-specific native code know this process is gone. */ | |
3889 | linux_nat_forget_process (pid); | |
d6b0e80f AC |
3890 | } |
3891 | ||
5b009018 PA |
3892 | /* Convert a native/host siginfo object, into/from the siginfo in the |
3893 | layout of the inferiors' architecture. */ | |
3894 | ||
3895 | static void | |
a5362b9a | 3896 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
5b009018 PA |
3897 | { |
3898 | int done = 0; | |
3899 | ||
3900 | if (linux_nat_siginfo_fixup != NULL) | |
3901 | done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction); | |
3902 | ||
3903 | /* If there was no callback, or the callback didn't do anything, | |
3904 | then just do a straight memcpy. */ | |
3905 | if (!done) | |
3906 | { | |
3907 | if (direction == 1) | |
a5362b9a | 3908 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
5b009018 | 3909 | else |
a5362b9a | 3910 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
5b009018 PA |
3911 | } |
3912 | } | |
3913 | ||
9b409511 | 3914 | static enum target_xfer_status |
4aa995e1 PA |
3915 | linux_xfer_siginfo (struct target_ops *ops, enum target_object object, |
3916 | const char *annex, gdb_byte *readbuf, | |
9b409511 YQ |
3917 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
3918 | ULONGEST *xfered_len) | |
4aa995e1 | 3919 | { |
4aa995e1 | 3920 | int pid; |
a5362b9a TS |
3921 | siginfo_t siginfo; |
3922 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; | |
4aa995e1 PA |
3923 | |
3924 | gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO); | |
3925 | gdb_assert (readbuf || writebuf); | |
3926 | ||
dfd4cc63 | 3927 | pid = ptid_get_lwp (inferior_ptid); |
4aa995e1 | 3928 | if (pid == 0) |
dfd4cc63 | 3929 | pid = ptid_get_pid (inferior_ptid); |
4aa995e1 PA |
3930 | |
3931 | if (offset > sizeof (siginfo)) | |
2ed4b548 | 3932 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3933 | |
3934 | errno = 0; | |
3935 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3936 | if (errno != 0) | |
2ed4b548 | 3937 | return TARGET_XFER_E_IO; |
4aa995e1 | 3938 | |
5b009018 PA |
3939 | /* When GDB is built as a 64-bit application, ptrace writes into |
3940 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
3941 | inferior with a 64-bit GDB should look the same as debugging it | |
3942 | with a 32-bit GDB, we need to convert it. GDB core always sees | |
3943 | the converted layout, so any read/write will have to be done | |
3944 | post-conversion. */ | |
3945 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
3946 | ||
4aa995e1 PA |
3947 | if (offset + len > sizeof (siginfo)) |
3948 | len = sizeof (siginfo) - offset; | |
3949 | ||
3950 | if (readbuf != NULL) | |
5b009018 | 3951 | memcpy (readbuf, inf_siginfo + offset, len); |
4aa995e1 PA |
3952 | else |
3953 | { | |
5b009018 PA |
3954 | memcpy (inf_siginfo + offset, writebuf, len); |
3955 | ||
3956 | /* Convert back to ptrace layout before flushing it out. */ | |
3957 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
3958 | ||
4aa995e1 PA |
3959 | errno = 0; |
3960 | ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3961 | if (errno != 0) | |
2ed4b548 | 3962 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3963 | } |
3964 | ||
9b409511 YQ |
3965 | *xfered_len = len; |
3966 | return TARGET_XFER_OK; | |
4aa995e1 PA |
3967 | } |
3968 | ||
9b409511 | 3969 | static enum target_xfer_status |
10d6c8cd DJ |
3970 | linux_nat_xfer_partial (struct target_ops *ops, enum target_object object, |
3971 | const char *annex, gdb_byte *readbuf, | |
3972 | const gdb_byte *writebuf, | |
9b409511 | 3973 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) |
d6b0e80f | 3974 | { |
4aa995e1 | 3975 | struct cleanup *old_chain; |
9b409511 | 3976 | enum target_xfer_status xfer; |
d6b0e80f | 3977 | |
4aa995e1 PA |
3978 | if (object == TARGET_OBJECT_SIGNAL_INFO) |
3979 | return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf, | |
9b409511 | 3980 | offset, len, xfered_len); |
4aa995e1 | 3981 | |
c35b1492 PA |
3982 | /* The target is connected but no live inferior is selected. Pass |
3983 | this request down to a lower stratum (e.g., the executable | |
3984 | file). */ | |
3985 | if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid)) | |
9b409511 | 3986 | return TARGET_XFER_EOF; |
c35b1492 | 3987 | |
4aa995e1 PA |
3988 | old_chain = save_inferior_ptid (); |
3989 | ||
dfd4cc63 LM |
3990 | if (ptid_lwp_p (inferior_ptid)) |
3991 | inferior_ptid = pid_to_ptid (ptid_get_lwp (inferior_ptid)); | |
d6b0e80f | 3992 | |
10d6c8cd | 3993 | xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf, |
9b409511 | 3994 | offset, len, xfered_len); |
d6b0e80f AC |
3995 | |
3996 | do_cleanups (old_chain); | |
3997 | return xfer; | |
3998 | } | |
3999 | ||
4000 | static int | |
28439f5e | 4001 | linux_thread_alive (ptid_t ptid) |
d6b0e80f | 4002 | { |
8c6a60d1 | 4003 | int err, tmp_errno; |
4c28f408 | 4004 | |
dfd4cc63 | 4005 | gdb_assert (ptid_lwp_p (ptid)); |
d6b0e80f | 4006 | |
4c28f408 PA |
4007 | /* Send signal 0 instead of anything ptrace, because ptracing a |
4008 | running thread errors out claiming that the thread doesn't | |
4009 | exist. */ | |
dfd4cc63 | 4010 | err = kill_lwp (ptid_get_lwp (ptid), 0); |
8c6a60d1 | 4011 | tmp_errno = errno; |
d6b0e80f AC |
4012 | if (debug_linux_nat) |
4013 | fprintf_unfiltered (gdb_stdlog, | |
4c28f408 | 4014 | "LLTA: KILL(SIG0) %s (%s)\n", |
d6b0e80f | 4015 | target_pid_to_str (ptid), |
8c6a60d1 | 4016 | err ? safe_strerror (tmp_errno) : "OK"); |
9c0dd46b | 4017 | |
4c28f408 | 4018 | if (err != 0) |
d6b0e80f AC |
4019 | return 0; |
4020 | ||
4021 | return 1; | |
4022 | } | |
4023 | ||
28439f5e PA |
4024 | static int |
4025 | linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid) | |
4026 | { | |
4027 | return linux_thread_alive (ptid); | |
4028 | } | |
4029 | ||
d6b0e80f | 4030 | static char * |
117de6a9 | 4031 | linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid) |
d6b0e80f AC |
4032 | { |
4033 | static char buf[64]; | |
4034 | ||
dfd4cc63 LM |
4035 | if (ptid_lwp_p (ptid) |
4036 | && (ptid_get_pid (ptid) != ptid_get_lwp (ptid) | |
4037 | || num_lwps (ptid_get_pid (ptid)) > 1)) | |
d6b0e80f | 4038 | { |
dfd4cc63 | 4039 | snprintf (buf, sizeof (buf), "LWP %ld", ptid_get_lwp (ptid)); |
d6b0e80f AC |
4040 | return buf; |
4041 | } | |
4042 | ||
4043 | return normal_pid_to_str (ptid); | |
4044 | } | |
4045 | ||
4694da01 | 4046 | static char * |
503a628d | 4047 | linux_nat_thread_name (struct target_ops *self, struct thread_info *thr) |
4694da01 TT |
4048 | { |
4049 | int pid = ptid_get_pid (thr->ptid); | |
4050 | long lwp = ptid_get_lwp (thr->ptid); | |
4051 | #define FORMAT "/proc/%d/task/%ld/comm" | |
4052 | char buf[sizeof (FORMAT) + 30]; | |
4053 | FILE *comm_file; | |
4054 | char *result = NULL; | |
4055 | ||
4056 | snprintf (buf, sizeof (buf), FORMAT, pid, lwp); | |
614c279d | 4057 | comm_file = gdb_fopen_cloexec (buf, "r"); |
4694da01 TT |
4058 | if (comm_file) |
4059 | { | |
4060 | /* Not exported by the kernel, so we define it here. */ | |
4061 | #define COMM_LEN 16 | |
4062 | static char line[COMM_LEN + 1]; | |
4063 | ||
4064 | if (fgets (line, sizeof (line), comm_file)) | |
4065 | { | |
4066 | char *nl = strchr (line, '\n'); | |
4067 | ||
4068 | if (nl) | |
4069 | *nl = '\0'; | |
4070 | if (*line != '\0') | |
4071 | result = line; | |
4072 | } | |
4073 | ||
4074 | fclose (comm_file); | |
4075 | } | |
4076 | ||
4077 | #undef COMM_LEN | |
4078 | #undef FORMAT | |
4079 | ||
4080 | return result; | |
4081 | } | |
4082 | ||
dba24537 AC |
4083 | /* Accepts an integer PID; Returns a string representing a file that |
4084 | can be opened to get the symbols for the child process. */ | |
4085 | ||
6d8fd2b7 | 4086 | static char * |
8dd27370 | 4087 | linux_child_pid_to_exec_file (struct target_ops *self, int pid) |
dba24537 | 4088 | { |
b4ab256d HZ |
4089 | static char buf[PATH_MAX]; |
4090 | char name[PATH_MAX]; | |
dba24537 | 4091 | |
b4ab256d HZ |
4092 | xsnprintf (name, PATH_MAX, "/proc/%d/exe", pid); |
4093 | memset (buf, 0, PATH_MAX); | |
4094 | if (readlink (name, buf, PATH_MAX - 1) <= 0) | |
4095 | strcpy (buf, name); | |
dba24537 | 4096 | |
b4ab256d | 4097 | return buf; |
dba24537 AC |
4098 | } |
4099 | ||
10d6c8cd DJ |
4100 | /* Implement the to_xfer_partial interface for memory reads using the /proc |
4101 | filesystem. Because we can use a single read() call for /proc, this | |
4102 | can be much more efficient than banging away at PTRACE_PEEKTEXT, | |
4103 | but it doesn't support writes. */ | |
4104 | ||
9b409511 | 4105 | static enum target_xfer_status |
10d6c8cd DJ |
4106 | linux_proc_xfer_partial (struct target_ops *ops, enum target_object object, |
4107 | const char *annex, gdb_byte *readbuf, | |
4108 | const gdb_byte *writebuf, | |
9b409511 | 4109 | ULONGEST offset, LONGEST len, ULONGEST *xfered_len) |
dba24537 | 4110 | { |
10d6c8cd DJ |
4111 | LONGEST ret; |
4112 | int fd; | |
dba24537 AC |
4113 | char filename[64]; |
4114 | ||
10d6c8cd | 4115 | if (object != TARGET_OBJECT_MEMORY || !readbuf) |
dba24537 AC |
4116 | return 0; |
4117 | ||
4118 | /* Don't bother for one word. */ | |
4119 | if (len < 3 * sizeof (long)) | |
9b409511 | 4120 | return TARGET_XFER_EOF; |
dba24537 AC |
4121 | |
4122 | /* We could keep this file open and cache it - possibly one per | |
4123 | thread. That requires some juggling, but is even faster. */ | |
cde33bf1 YQ |
4124 | xsnprintf (filename, sizeof filename, "/proc/%d/mem", |
4125 | ptid_get_pid (inferior_ptid)); | |
614c279d | 4126 | fd = gdb_open_cloexec (filename, O_RDONLY | O_LARGEFILE, 0); |
dba24537 | 4127 | if (fd == -1) |
9b409511 | 4128 | return TARGET_XFER_EOF; |
dba24537 AC |
4129 | |
4130 | /* If pread64 is available, use it. It's faster if the kernel | |
4131 | supports it (only one syscall), and it's 64-bit safe even on | |
4132 | 32-bit platforms (for instance, SPARC debugging a SPARC64 | |
4133 | application). */ | |
4134 | #ifdef HAVE_PREAD64 | |
10d6c8cd | 4135 | if (pread64 (fd, readbuf, len, offset) != len) |
dba24537 | 4136 | #else |
10d6c8cd | 4137 | if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len) |
dba24537 AC |
4138 | #endif |
4139 | ret = 0; | |
4140 | else | |
4141 | ret = len; | |
4142 | ||
4143 | close (fd); | |
9b409511 YQ |
4144 | |
4145 | if (ret == 0) | |
4146 | return TARGET_XFER_EOF; | |
4147 | else | |
4148 | { | |
4149 | *xfered_len = ret; | |
4150 | return TARGET_XFER_OK; | |
4151 | } | |
dba24537 AC |
4152 | } |
4153 | ||
efcbbd14 UW |
4154 | |
4155 | /* Enumerate spufs IDs for process PID. */ | |
4156 | static LONGEST | |
b55e14c7 | 4157 | spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, ULONGEST len) |
efcbbd14 | 4158 | { |
f5656ead | 4159 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
efcbbd14 UW |
4160 | LONGEST pos = 0; |
4161 | LONGEST written = 0; | |
4162 | char path[128]; | |
4163 | DIR *dir; | |
4164 | struct dirent *entry; | |
4165 | ||
4166 | xsnprintf (path, sizeof path, "/proc/%d/fd", pid); | |
4167 | dir = opendir (path); | |
4168 | if (!dir) | |
4169 | return -1; | |
4170 | ||
4171 | rewinddir (dir); | |
4172 | while ((entry = readdir (dir)) != NULL) | |
4173 | { | |
4174 | struct stat st; | |
4175 | struct statfs stfs; | |
4176 | int fd; | |
4177 | ||
4178 | fd = atoi (entry->d_name); | |
4179 | if (!fd) | |
4180 | continue; | |
4181 | ||
4182 | xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd); | |
4183 | if (stat (path, &st) != 0) | |
4184 | continue; | |
4185 | if (!S_ISDIR (st.st_mode)) | |
4186 | continue; | |
4187 | ||
4188 | if (statfs (path, &stfs) != 0) | |
4189 | continue; | |
4190 | if (stfs.f_type != SPUFS_MAGIC) | |
4191 | continue; | |
4192 | ||
4193 | if (pos >= offset && pos + 4 <= offset + len) | |
4194 | { | |
4195 | store_unsigned_integer (buf + pos - offset, 4, byte_order, fd); | |
4196 | written += 4; | |
4197 | } | |
4198 | pos += 4; | |
4199 | } | |
4200 | ||
4201 | closedir (dir); | |
4202 | return written; | |
4203 | } | |
4204 | ||
4205 | /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU | |
4206 | object type, using the /proc file system. */ | |
9b409511 YQ |
4207 | |
4208 | static enum target_xfer_status | |
efcbbd14 UW |
4209 | linux_proc_xfer_spu (struct target_ops *ops, enum target_object object, |
4210 | const char *annex, gdb_byte *readbuf, | |
4211 | const gdb_byte *writebuf, | |
9b409511 | 4212 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) |
efcbbd14 UW |
4213 | { |
4214 | char buf[128]; | |
4215 | int fd = 0; | |
4216 | int ret = -1; | |
dfd4cc63 | 4217 | int pid = ptid_get_pid (inferior_ptid); |
efcbbd14 UW |
4218 | |
4219 | if (!annex) | |
4220 | { | |
4221 | if (!readbuf) | |
2ed4b548 | 4222 | return TARGET_XFER_E_IO; |
efcbbd14 | 4223 | else |
9b409511 YQ |
4224 | { |
4225 | LONGEST l = spu_enumerate_spu_ids (pid, readbuf, offset, len); | |
4226 | ||
4227 | if (l < 0) | |
4228 | return TARGET_XFER_E_IO; | |
4229 | else if (l == 0) | |
4230 | return TARGET_XFER_EOF; | |
4231 | else | |
4232 | { | |
4233 | *xfered_len = (ULONGEST) l; | |
4234 | return TARGET_XFER_OK; | |
4235 | } | |
4236 | } | |
efcbbd14 UW |
4237 | } |
4238 | ||
4239 | xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex); | |
614c279d | 4240 | fd = gdb_open_cloexec (buf, writebuf? O_WRONLY : O_RDONLY, 0); |
efcbbd14 | 4241 | if (fd <= 0) |
2ed4b548 | 4242 | return TARGET_XFER_E_IO; |
efcbbd14 UW |
4243 | |
4244 | if (offset != 0 | |
4245 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) | |
4246 | { | |
4247 | close (fd); | |
9b409511 | 4248 | return TARGET_XFER_EOF; |
efcbbd14 UW |
4249 | } |
4250 | ||
4251 | if (writebuf) | |
4252 | ret = write (fd, writebuf, (size_t) len); | |
4253 | else if (readbuf) | |
4254 | ret = read (fd, readbuf, (size_t) len); | |
4255 | ||
4256 | close (fd); | |
9b409511 YQ |
4257 | |
4258 | if (ret < 0) | |
4259 | return TARGET_XFER_E_IO; | |
4260 | else if (ret == 0) | |
4261 | return TARGET_XFER_EOF; | |
4262 | else | |
4263 | { | |
4264 | *xfered_len = (ULONGEST) ret; | |
4265 | return TARGET_XFER_OK; | |
4266 | } | |
efcbbd14 UW |
4267 | } |
4268 | ||
4269 | ||
dba24537 AC |
4270 | /* Parse LINE as a signal set and add its set bits to SIGS. */ |
4271 | ||
4272 | static void | |
4273 | add_line_to_sigset (const char *line, sigset_t *sigs) | |
4274 | { | |
4275 | int len = strlen (line) - 1; | |
4276 | const char *p; | |
4277 | int signum; | |
4278 | ||
4279 | if (line[len] != '\n') | |
8a3fe4f8 | 4280 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4281 | |
4282 | p = line; | |
4283 | signum = len * 4; | |
4284 | while (len-- > 0) | |
4285 | { | |
4286 | int digit; | |
4287 | ||
4288 | if (*p >= '0' && *p <= '9') | |
4289 | digit = *p - '0'; | |
4290 | else if (*p >= 'a' && *p <= 'f') | |
4291 | digit = *p - 'a' + 10; | |
4292 | else | |
8a3fe4f8 | 4293 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4294 | |
4295 | signum -= 4; | |
4296 | ||
4297 | if (digit & 1) | |
4298 | sigaddset (sigs, signum + 1); | |
4299 | if (digit & 2) | |
4300 | sigaddset (sigs, signum + 2); | |
4301 | if (digit & 4) | |
4302 | sigaddset (sigs, signum + 3); | |
4303 | if (digit & 8) | |
4304 | sigaddset (sigs, signum + 4); | |
4305 | ||
4306 | p++; | |
4307 | } | |
4308 | } | |
4309 | ||
4310 | /* Find process PID's pending signals from /proc/pid/status and set | |
4311 | SIGS to match. */ | |
4312 | ||
4313 | void | |
3e43a32a MS |
4314 | linux_proc_pending_signals (int pid, sigset_t *pending, |
4315 | sigset_t *blocked, sigset_t *ignored) | |
dba24537 AC |
4316 | { |
4317 | FILE *procfile; | |
d8d2a3ee | 4318 | char buffer[PATH_MAX], fname[PATH_MAX]; |
7c8a8b04 | 4319 | struct cleanup *cleanup; |
dba24537 AC |
4320 | |
4321 | sigemptyset (pending); | |
4322 | sigemptyset (blocked); | |
4323 | sigemptyset (ignored); | |
cde33bf1 | 4324 | xsnprintf (fname, sizeof fname, "/proc/%d/status", pid); |
614c279d | 4325 | procfile = gdb_fopen_cloexec (fname, "r"); |
dba24537 | 4326 | if (procfile == NULL) |
8a3fe4f8 | 4327 | error (_("Could not open %s"), fname); |
7c8a8b04 | 4328 | cleanup = make_cleanup_fclose (procfile); |
dba24537 | 4329 | |
d8d2a3ee | 4330 | while (fgets (buffer, PATH_MAX, procfile) != NULL) |
dba24537 AC |
4331 | { |
4332 | /* Normal queued signals are on the SigPnd line in the status | |
4333 | file. However, 2.6 kernels also have a "shared" pending | |
4334 | queue for delivering signals to a thread group, so check for | |
4335 | a ShdPnd line also. | |
4336 | ||
4337 | Unfortunately some Red Hat kernels include the shared pending | |
4338 | queue but not the ShdPnd status field. */ | |
4339 | ||
61012eef | 4340 | if (startswith (buffer, "SigPnd:\t")) |
dba24537 | 4341 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4342 | else if (startswith (buffer, "ShdPnd:\t")) |
dba24537 | 4343 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4344 | else if (startswith (buffer, "SigBlk:\t")) |
dba24537 | 4345 | add_line_to_sigset (buffer + 8, blocked); |
61012eef | 4346 | else if (startswith (buffer, "SigIgn:\t")) |
dba24537 AC |
4347 | add_line_to_sigset (buffer + 8, ignored); |
4348 | } | |
4349 | ||
7c8a8b04 | 4350 | do_cleanups (cleanup); |
dba24537 AC |
4351 | } |
4352 | ||
9b409511 | 4353 | static enum target_xfer_status |
07e059b5 | 4354 | linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object, |
e0881a8e | 4355 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
4356 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
4357 | ULONGEST *xfered_len) | |
07e059b5 | 4358 | { |
07e059b5 VP |
4359 | gdb_assert (object == TARGET_OBJECT_OSDATA); |
4360 | ||
9b409511 YQ |
4361 | *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len); |
4362 | if (*xfered_len == 0) | |
4363 | return TARGET_XFER_EOF; | |
4364 | else | |
4365 | return TARGET_XFER_OK; | |
07e059b5 VP |
4366 | } |
4367 | ||
9b409511 | 4368 | static enum target_xfer_status |
10d6c8cd DJ |
4369 | linux_xfer_partial (struct target_ops *ops, enum target_object object, |
4370 | const char *annex, gdb_byte *readbuf, | |
9b409511 YQ |
4371 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
4372 | ULONGEST *xfered_len) | |
10d6c8cd | 4373 | { |
9b409511 | 4374 | enum target_xfer_status xfer; |
10d6c8cd DJ |
4375 | |
4376 | if (object == TARGET_OBJECT_AUXV) | |
9f2982ff | 4377 | return memory_xfer_auxv (ops, object, annex, readbuf, writebuf, |
9b409511 | 4378 | offset, len, xfered_len); |
10d6c8cd | 4379 | |
07e059b5 VP |
4380 | if (object == TARGET_OBJECT_OSDATA) |
4381 | return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf, | |
9b409511 | 4382 | offset, len, xfered_len); |
07e059b5 | 4383 | |
efcbbd14 UW |
4384 | if (object == TARGET_OBJECT_SPU) |
4385 | return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf, | |
9b409511 | 4386 | offset, len, xfered_len); |
efcbbd14 | 4387 | |
8f313923 JK |
4388 | /* GDB calculates all the addresses in possibly larget width of the address. |
4389 | Address width needs to be masked before its final use - either by | |
4390 | linux_proc_xfer_partial or inf_ptrace_xfer_partial. | |
4391 | ||
4392 | Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ | |
4393 | ||
4394 | if (object == TARGET_OBJECT_MEMORY) | |
4395 | { | |
f5656ead | 4396 | int addr_bit = gdbarch_addr_bit (target_gdbarch ()); |
8f313923 JK |
4397 | |
4398 | if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) | |
4399 | offset &= ((ULONGEST) 1 << addr_bit) - 1; | |
4400 | } | |
4401 | ||
10d6c8cd | 4402 | xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf, |
9b409511 YQ |
4403 | offset, len, xfered_len); |
4404 | if (xfer != TARGET_XFER_EOF) | |
10d6c8cd DJ |
4405 | return xfer; |
4406 | ||
4407 | return super_xfer_partial (ops, object, annex, readbuf, writebuf, | |
9b409511 | 4408 | offset, len, xfered_len); |
10d6c8cd DJ |
4409 | } |
4410 | ||
5808517f YQ |
4411 | static void |
4412 | cleanup_target_stop (void *arg) | |
4413 | { | |
4414 | ptid_t *ptid = (ptid_t *) arg; | |
4415 | ||
4416 | gdb_assert (arg != NULL); | |
4417 | ||
4418 | /* Unpause all */ | |
a493e3e2 | 4419 | target_resume (*ptid, 0, GDB_SIGNAL_0); |
5808517f YQ |
4420 | } |
4421 | ||
4422 | static VEC(static_tracepoint_marker_p) * | |
c686c57f TT |
4423 | linux_child_static_tracepoint_markers_by_strid (struct target_ops *self, |
4424 | const char *strid) | |
5808517f YQ |
4425 | { |
4426 | char s[IPA_CMD_BUF_SIZE]; | |
4427 | struct cleanup *old_chain; | |
4428 | int pid = ptid_get_pid (inferior_ptid); | |
4429 | VEC(static_tracepoint_marker_p) *markers = NULL; | |
4430 | struct static_tracepoint_marker *marker = NULL; | |
4431 | char *p = s; | |
4432 | ptid_t ptid = ptid_build (pid, 0, 0); | |
4433 | ||
4434 | /* Pause all */ | |
4435 | target_stop (ptid); | |
4436 | ||
4437 | memcpy (s, "qTfSTM", sizeof ("qTfSTM")); | |
4438 | s[sizeof ("qTfSTM")] = 0; | |
4439 | ||
42476b70 | 4440 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4441 | |
4442 | old_chain = make_cleanup (free_current_marker, &marker); | |
4443 | make_cleanup (cleanup_target_stop, &ptid); | |
4444 | ||
4445 | while (*p++ == 'm') | |
4446 | { | |
4447 | if (marker == NULL) | |
4448 | marker = XCNEW (struct static_tracepoint_marker); | |
4449 | ||
4450 | do | |
4451 | { | |
4452 | parse_static_tracepoint_marker_definition (p, &p, marker); | |
4453 | ||
4454 | if (strid == NULL || strcmp (strid, marker->str_id) == 0) | |
4455 | { | |
4456 | VEC_safe_push (static_tracepoint_marker_p, | |
4457 | markers, marker); | |
4458 | marker = NULL; | |
4459 | } | |
4460 | else | |
4461 | { | |
4462 | release_static_tracepoint_marker (marker); | |
4463 | memset (marker, 0, sizeof (*marker)); | |
4464 | } | |
4465 | } | |
4466 | while (*p++ == ','); /* comma-separated list */ | |
4467 | ||
4468 | memcpy (s, "qTsSTM", sizeof ("qTsSTM")); | |
4469 | s[sizeof ("qTsSTM")] = 0; | |
42476b70 | 4470 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4471 | p = s; |
4472 | } | |
4473 | ||
4474 | do_cleanups (old_chain); | |
4475 | ||
4476 | return markers; | |
4477 | } | |
4478 | ||
e9efe249 | 4479 | /* Create a prototype generic GNU/Linux target. The client can override |
10d6c8cd DJ |
4480 | it with local methods. */ |
4481 | ||
910122bf UW |
4482 | static void |
4483 | linux_target_install_ops (struct target_ops *t) | |
10d6c8cd | 4484 | { |
6d8fd2b7 | 4485 | t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint; |
eb73ad13 | 4486 | t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint; |
6d8fd2b7 | 4487 | t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint; |
eb73ad13 | 4488 | t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint; |
6d8fd2b7 | 4489 | t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint; |
eb73ad13 | 4490 | t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint; |
a96d9b2e | 4491 | t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint; |
6d8fd2b7 | 4492 | t->to_pid_to_exec_file = linux_child_pid_to_exec_file; |
10d6c8cd | 4493 | t->to_post_startup_inferior = linux_child_post_startup_inferior; |
6d8fd2b7 UW |
4494 | t->to_post_attach = linux_child_post_attach; |
4495 | t->to_follow_fork = linux_child_follow_fork; | |
10d6c8cd DJ |
4496 | |
4497 | super_xfer_partial = t->to_xfer_partial; | |
4498 | t->to_xfer_partial = linux_xfer_partial; | |
5808517f YQ |
4499 | |
4500 | t->to_static_tracepoint_markers_by_strid | |
4501 | = linux_child_static_tracepoint_markers_by_strid; | |
910122bf UW |
4502 | } |
4503 | ||
4504 | struct target_ops * | |
4505 | linux_target (void) | |
4506 | { | |
4507 | struct target_ops *t; | |
4508 | ||
4509 | t = inf_ptrace_target (); | |
4510 | linux_target_install_ops (t); | |
4511 | ||
4512 | return t; | |
4513 | } | |
4514 | ||
4515 | struct target_ops * | |
7714d83a | 4516 | linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int)) |
910122bf UW |
4517 | { |
4518 | struct target_ops *t; | |
4519 | ||
4520 | t = inf_ptrace_trad_target (register_u_offset); | |
4521 | linux_target_install_ops (t); | |
10d6c8cd | 4522 | |
10d6c8cd DJ |
4523 | return t; |
4524 | } | |
4525 | ||
b84876c2 PA |
4526 | /* target_is_async_p implementation. */ |
4527 | ||
4528 | static int | |
6a109b6b | 4529 | linux_nat_is_async_p (struct target_ops *ops) |
b84876c2 | 4530 | { |
198297aa | 4531 | return linux_is_async_p (); |
b84876c2 PA |
4532 | } |
4533 | ||
4534 | /* target_can_async_p implementation. */ | |
4535 | ||
4536 | static int | |
6a109b6b | 4537 | linux_nat_can_async_p (struct target_ops *ops) |
b84876c2 PA |
4538 | { |
4539 | /* NOTE: palves 2008-03-21: We're only async when the user requests | |
7feb7d06 | 4540 | it explicitly with the "set target-async" command. |
b84876c2 | 4541 | Someday, linux will always be async. */ |
3dd5b83d | 4542 | return target_async_permitted; |
b84876c2 PA |
4543 | } |
4544 | ||
9908b566 | 4545 | static int |
2a9a2795 | 4546 | linux_nat_supports_non_stop (struct target_ops *self) |
9908b566 VP |
4547 | { |
4548 | return 1; | |
4549 | } | |
4550 | ||
d90e17a7 PA |
4551 | /* True if we want to support multi-process. To be removed when GDB |
4552 | supports multi-exec. */ | |
4553 | ||
2277426b | 4554 | int linux_multi_process = 1; |
d90e17a7 PA |
4555 | |
4556 | static int | |
86ce2668 | 4557 | linux_nat_supports_multi_process (struct target_ops *self) |
d90e17a7 PA |
4558 | { |
4559 | return linux_multi_process; | |
4560 | } | |
4561 | ||
03583c20 | 4562 | static int |
2bfc0540 | 4563 | linux_nat_supports_disable_randomization (struct target_ops *self) |
03583c20 UW |
4564 | { |
4565 | #ifdef HAVE_PERSONALITY | |
4566 | return 1; | |
4567 | #else | |
4568 | return 0; | |
4569 | #endif | |
4570 | } | |
4571 | ||
b84876c2 PA |
4572 | static int async_terminal_is_ours = 1; |
4573 | ||
4d4ca2a1 DE |
4574 | /* target_terminal_inferior implementation. |
4575 | ||
4576 | This is a wrapper around child_terminal_inferior to add async support. */ | |
b84876c2 PA |
4577 | |
4578 | static void | |
d2f640d4 | 4579 | linux_nat_terminal_inferior (struct target_ops *self) |
b84876c2 | 4580 | { |
198297aa PA |
4581 | /* Like target_terminal_inferior, use target_can_async_p, not |
4582 | target_is_async_p, since at this point the target is not async | |
4583 | yet. If it can async, then we know it will become async prior to | |
4584 | resume. */ | |
4585 | if (!target_can_async_p ()) | |
b84876c2 PA |
4586 | { |
4587 | /* Async mode is disabled. */ | |
d6b64346 | 4588 | child_terminal_inferior (self); |
b84876c2 PA |
4589 | return; |
4590 | } | |
4591 | ||
d6b64346 | 4592 | child_terminal_inferior (self); |
b84876c2 | 4593 | |
d9d2d8b6 | 4594 | /* Calls to target_terminal_*() are meant to be idempotent. */ |
b84876c2 PA |
4595 | if (!async_terminal_is_ours) |
4596 | return; | |
4597 | ||
4598 | delete_file_handler (input_fd); | |
4599 | async_terminal_is_ours = 0; | |
4600 | set_sigint_trap (); | |
4601 | } | |
4602 | ||
4d4ca2a1 DE |
4603 | /* target_terminal_ours implementation. |
4604 | ||
4605 | This is a wrapper around child_terminal_ours to add async support (and | |
4606 | implement the target_terminal_ours vs target_terminal_ours_for_output | |
4607 | distinction). child_terminal_ours is currently no different than | |
4608 | child_terminal_ours_for_output. | |
4609 | We leave target_terminal_ours_for_output alone, leaving it to | |
4610 | child_terminal_ours_for_output. */ | |
b84876c2 | 4611 | |
2c0b251b | 4612 | static void |
e3594fd1 | 4613 | linux_nat_terminal_ours (struct target_ops *self) |
b84876c2 | 4614 | { |
b84876c2 PA |
4615 | /* GDB should never give the terminal to the inferior if the |
4616 | inferior is running in the background (run&, continue&, etc.), | |
4617 | but claiming it sure should. */ | |
d6b64346 | 4618 | child_terminal_ours (self); |
b84876c2 | 4619 | |
b84876c2 PA |
4620 | if (async_terminal_is_ours) |
4621 | return; | |
4622 | ||
4623 | clear_sigint_trap (); | |
4624 | add_file_handler (input_fd, stdin_event_handler, 0); | |
4625 | async_terminal_is_ours = 1; | |
4626 | } | |
4627 | ||
4628 | static void (*async_client_callback) (enum inferior_event_type event_type, | |
4629 | void *context); | |
4630 | static void *async_client_context; | |
4631 | ||
7feb7d06 PA |
4632 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
4633 | so we notice when any child changes state, and notify the | |
4634 | event-loop; it allows us to use sigsuspend in linux_nat_wait_1 | |
4635 | above to wait for the arrival of a SIGCHLD. */ | |
4636 | ||
b84876c2 | 4637 | static void |
7feb7d06 | 4638 | sigchld_handler (int signo) |
b84876c2 | 4639 | { |
7feb7d06 PA |
4640 | int old_errno = errno; |
4641 | ||
01124a23 DE |
4642 | if (debug_linux_nat) |
4643 | ui_file_write_async_safe (gdb_stdlog, | |
4644 | "sigchld\n", sizeof ("sigchld\n") - 1); | |
7feb7d06 PA |
4645 | |
4646 | if (signo == SIGCHLD | |
4647 | && linux_nat_event_pipe[0] != -1) | |
4648 | async_file_mark (); /* Let the event loop know that there are | |
4649 | events to handle. */ | |
4650 | ||
4651 | errno = old_errno; | |
4652 | } | |
4653 | ||
4654 | /* Callback registered with the target events file descriptor. */ | |
4655 | ||
4656 | static void | |
4657 | handle_target_event (int error, gdb_client_data client_data) | |
4658 | { | |
4659 | (*async_client_callback) (INF_REG_EVENT, async_client_context); | |
4660 | } | |
4661 | ||
4662 | /* Create/destroy the target events pipe. Returns previous state. */ | |
4663 | ||
4664 | static int | |
4665 | linux_async_pipe (int enable) | |
4666 | { | |
198297aa | 4667 | int previous = linux_is_async_p (); |
7feb7d06 PA |
4668 | |
4669 | if (previous != enable) | |
4670 | { | |
4671 | sigset_t prev_mask; | |
4672 | ||
12696c10 PA |
4673 | /* Block child signals while we create/destroy the pipe, as |
4674 | their handler writes to it. */ | |
7feb7d06 PA |
4675 | block_child_signals (&prev_mask); |
4676 | ||
4677 | if (enable) | |
4678 | { | |
614c279d | 4679 | if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1) |
7feb7d06 PA |
4680 | internal_error (__FILE__, __LINE__, |
4681 | "creating event pipe failed."); | |
4682 | ||
4683 | fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK); | |
4684 | fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK); | |
4685 | } | |
4686 | else | |
4687 | { | |
4688 | close (linux_nat_event_pipe[0]); | |
4689 | close (linux_nat_event_pipe[1]); | |
4690 | linux_nat_event_pipe[0] = -1; | |
4691 | linux_nat_event_pipe[1] = -1; | |
4692 | } | |
4693 | ||
4694 | restore_child_signals_mask (&prev_mask); | |
4695 | } | |
4696 | ||
4697 | return previous; | |
b84876c2 PA |
4698 | } |
4699 | ||
4700 | /* target_async implementation. */ | |
4701 | ||
4702 | static void | |
6a109b6b TT |
4703 | linux_nat_async (struct target_ops *ops, |
4704 | void (*callback) (enum inferior_event_type event_type, | |
4705 | void *context), | |
4706 | void *context) | |
b84876c2 | 4707 | { |
b84876c2 PA |
4708 | if (callback != NULL) |
4709 | { | |
4710 | async_client_callback = callback; | |
4711 | async_client_context = context; | |
7feb7d06 PA |
4712 | if (!linux_async_pipe (1)) |
4713 | { | |
4714 | add_file_handler (linux_nat_event_pipe[0], | |
4715 | handle_target_event, NULL); | |
4716 | /* There may be pending events to handle. Tell the event loop | |
4717 | to poll them. */ | |
4718 | async_file_mark (); | |
4719 | } | |
b84876c2 PA |
4720 | } |
4721 | else | |
4722 | { | |
4723 | async_client_callback = callback; | |
4724 | async_client_context = context; | |
b84876c2 | 4725 | delete_file_handler (linux_nat_event_pipe[0]); |
7feb7d06 | 4726 | linux_async_pipe (0); |
b84876c2 PA |
4727 | } |
4728 | return; | |
4729 | } | |
4730 | ||
a493e3e2 | 4731 | /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other |
252fbfc8 PA |
4732 | event came out. */ |
4733 | ||
4c28f408 | 4734 | static int |
252fbfc8 | 4735 | linux_nat_stop_lwp (struct lwp_info *lwp, void *data) |
4c28f408 | 4736 | { |
d90e17a7 | 4737 | if (!lwp->stopped) |
252fbfc8 | 4738 | { |
d90e17a7 PA |
4739 | if (debug_linux_nat) |
4740 | fprintf_unfiltered (gdb_stdlog, | |
4741 | "LNSL: running -> suspending %s\n", | |
4742 | target_pid_to_str (lwp->ptid)); | |
252fbfc8 | 4743 | |
252fbfc8 | 4744 | |
25289eb2 PA |
4745 | if (lwp->last_resume_kind == resume_stop) |
4746 | { | |
4747 | if (debug_linux_nat) | |
4748 | fprintf_unfiltered (gdb_stdlog, | |
4749 | "linux-nat: already stopping LWP %ld at " | |
4750 | "GDB's request\n", | |
4751 | ptid_get_lwp (lwp->ptid)); | |
4752 | return 0; | |
4753 | } | |
252fbfc8 | 4754 | |
25289eb2 PA |
4755 | stop_callback (lwp, NULL); |
4756 | lwp->last_resume_kind = resume_stop; | |
d90e17a7 PA |
4757 | } |
4758 | else | |
4759 | { | |
4760 | /* Already known to be stopped; do nothing. */ | |
252fbfc8 | 4761 | |
d90e17a7 PA |
4762 | if (debug_linux_nat) |
4763 | { | |
e09875d4 | 4764 | if (find_thread_ptid (lwp->ptid)->stop_requested) |
3e43a32a MS |
4765 | fprintf_unfiltered (gdb_stdlog, |
4766 | "LNSL: already stopped/stop_requested %s\n", | |
d90e17a7 PA |
4767 | target_pid_to_str (lwp->ptid)); |
4768 | else | |
3e43a32a MS |
4769 | fprintf_unfiltered (gdb_stdlog, |
4770 | "LNSL: already stopped/no " | |
4771 | "stop_requested yet %s\n", | |
d90e17a7 | 4772 | target_pid_to_str (lwp->ptid)); |
252fbfc8 PA |
4773 | } |
4774 | } | |
4c28f408 PA |
4775 | return 0; |
4776 | } | |
4777 | ||
4778 | static void | |
1eab8a48 | 4779 | linux_nat_stop (struct target_ops *self, ptid_t ptid) |
4c28f408 PA |
4780 | { |
4781 | if (non_stop) | |
d90e17a7 | 4782 | iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL); |
4c28f408 | 4783 | else |
1eab8a48 | 4784 | linux_ops->to_stop (linux_ops, ptid); |
4c28f408 PA |
4785 | } |
4786 | ||
d90e17a7 | 4787 | static void |
de90e03d | 4788 | linux_nat_close (struct target_ops *self) |
d90e17a7 PA |
4789 | { |
4790 | /* Unregister from the event loop. */ | |
9debeba0 DE |
4791 | if (linux_nat_is_async_p (self)) |
4792 | linux_nat_async (self, NULL, NULL); | |
d90e17a7 | 4793 | |
d90e17a7 | 4794 | if (linux_ops->to_close) |
de90e03d | 4795 | linux_ops->to_close (linux_ops); |
6a3cb8e8 PA |
4796 | |
4797 | super_close (self); | |
d90e17a7 PA |
4798 | } |
4799 | ||
c0694254 PA |
4800 | /* When requests are passed down from the linux-nat layer to the |
4801 | single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are | |
4802 | used. The address space pointer is stored in the inferior object, | |
4803 | but the common code that is passed such ptid can't tell whether | |
4804 | lwpid is a "main" process id or not (it assumes so). We reverse | |
4805 | look up the "main" process id from the lwp here. */ | |
4806 | ||
70221824 | 4807 | static struct address_space * |
c0694254 PA |
4808 | linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid) |
4809 | { | |
4810 | struct lwp_info *lwp; | |
4811 | struct inferior *inf; | |
4812 | int pid; | |
4813 | ||
dfd4cc63 | 4814 | if (ptid_get_lwp (ptid) == 0) |
c0694254 PA |
4815 | { |
4816 | /* An (lwpid,0,0) ptid. Look up the lwp object to get at the | |
4817 | tgid. */ | |
4818 | lwp = find_lwp_pid (ptid); | |
dfd4cc63 | 4819 | pid = ptid_get_pid (lwp->ptid); |
c0694254 PA |
4820 | } |
4821 | else | |
4822 | { | |
4823 | /* A (pid,lwpid,0) ptid. */ | |
dfd4cc63 | 4824 | pid = ptid_get_pid (ptid); |
c0694254 PA |
4825 | } |
4826 | ||
4827 | inf = find_inferior_pid (pid); | |
4828 | gdb_assert (inf != NULL); | |
4829 | return inf->aspace; | |
4830 | } | |
4831 | ||
dc146f7c VP |
4832 | /* Return the cached value of the processor core for thread PTID. */ |
4833 | ||
70221824 | 4834 | static int |
dc146f7c VP |
4835 | linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid) |
4836 | { | |
4837 | struct lwp_info *info = find_lwp_pid (ptid); | |
e0881a8e | 4838 | |
dc146f7c VP |
4839 | if (info) |
4840 | return info->core; | |
4841 | return -1; | |
4842 | } | |
4843 | ||
f973ed9c DJ |
4844 | void |
4845 | linux_nat_add_target (struct target_ops *t) | |
4846 | { | |
f973ed9c DJ |
4847 | /* Save the provided single-threaded target. We save this in a separate |
4848 | variable because another target we've inherited from (e.g. inf-ptrace) | |
4849 | may have saved a pointer to T; we want to use it for the final | |
4850 | process stratum target. */ | |
4851 | linux_ops_saved = *t; | |
4852 | linux_ops = &linux_ops_saved; | |
4853 | ||
4854 | /* Override some methods for multithreading. */ | |
b84876c2 | 4855 | t->to_create_inferior = linux_nat_create_inferior; |
f973ed9c DJ |
4856 | t->to_attach = linux_nat_attach; |
4857 | t->to_detach = linux_nat_detach; | |
4858 | t->to_resume = linux_nat_resume; | |
4859 | t->to_wait = linux_nat_wait; | |
2455069d | 4860 | t->to_pass_signals = linux_nat_pass_signals; |
f973ed9c DJ |
4861 | t->to_xfer_partial = linux_nat_xfer_partial; |
4862 | t->to_kill = linux_nat_kill; | |
4863 | t->to_mourn_inferior = linux_nat_mourn_inferior; | |
4864 | t->to_thread_alive = linux_nat_thread_alive; | |
4865 | t->to_pid_to_str = linux_nat_pid_to_str; | |
4694da01 | 4866 | t->to_thread_name = linux_nat_thread_name; |
f973ed9c | 4867 | t->to_has_thread_control = tc_schedlock; |
c0694254 | 4868 | t->to_thread_address_space = linux_nat_thread_address_space; |
ebec9a0f PA |
4869 | t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint; |
4870 | t->to_stopped_data_address = linux_nat_stopped_data_address; | |
faf09f01 PA |
4871 | t->to_stopped_by_sw_breakpoint = linux_nat_stopped_by_sw_breakpoint; |
4872 | t->to_supports_stopped_by_sw_breakpoint = linux_nat_supports_stopped_by_sw_breakpoint; | |
4873 | t->to_stopped_by_hw_breakpoint = linux_nat_stopped_by_hw_breakpoint; | |
4874 | t->to_supports_stopped_by_hw_breakpoint = linux_nat_supports_stopped_by_hw_breakpoint; | |
f973ed9c | 4875 | |
b84876c2 PA |
4876 | t->to_can_async_p = linux_nat_can_async_p; |
4877 | t->to_is_async_p = linux_nat_is_async_p; | |
9908b566 | 4878 | t->to_supports_non_stop = linux_nat_supports_non_stop; |
b84876c2 | 4879 | t->to_async = linux_nat_async; |
b84876c2 PA |
4880 | t->to_terminal_inferior = linux_nat_terminal_inferior; |
4881 | t->to_terminal_ours = linux_nat_terminal_ours; | |
6a3cb8e8 PA |
4882 | |
4883 | super_close = t->to_close; | |
d90e17a7 | 4884 | t->to_close = linux_nat_close; |
b84876c2 | 4885 | |
4c28f408 PA |
4886 | /* Methods for non-stop support. */ |
4887 | t->to_stop = linux_nat_stop; | |
4888 | ||
d90e17a7 PA |
4889 | t->to_supports_multi_process = linux_nat_supports_multi_process; |
4890 | ||
03583c20 UW |
4891 | t->to_supports_disable_randomization |
4892 | = linux_nat_supports_disable_randomization; | |
4893 | ||
dc146f7c VP |
4894 | t->to_core_of_thread = linux_nat_core_of_thread; |
4895 | ||
f973ed9c DJ |
4896 | /* We don't change the stratum; this target will sit at |
4897 | process_stratum and thread_db will set at thread_stratum. This | |
4898 | is a little strange, since this is a multi-threaded-capable | |
4899 | target, but we want to be on the stack below thread_db, and we | |
4900 | also want to be used for single-threaded processes. */ | |
4901 | ||
4902 | add_target (t); | |
f973ed9c DJ |
4903 | } |
4904 | ||
9f0bdab8 DJ |
4905 | /* Register a method to call whenever a new thread is attached. */ |
4906 | void | |
7b50312a PA |
4907 | linux_nat_set_new_thread (struct target_ops *t, |
4908 | void (*new_thread) (struct lwp_info *)) | |
9f0bdab8 DJ |
4909 | { |
4910 | /* Save the pointer. We only support a single registered instance | |
4911 | of the GNU/Linux native target, so we do not need to map this to | |
4912 | T. */ | |
4913 | linux_nat_new_thread = new_thread; | |
4914 | } | |
4915 | ||
26cb8b7c PA |
4916 | /* See declaration in linux-nat.h. */ |
4917 | ||
4918 | void | |
4919 | linux_nat_set_new_fork (struct target_ops *t, | |
4920 | linux_nat_new_fork_ftype *new_fork) | |
4921 | { | |
4922 | /* Save the pointer. */ | |
4923 | linux_nat_new_fork = new_fork; | |
4924 | } | |
4925 | ||
4926 | /* See declaration in linux-nat.h. */ | |
4927 | ||
4928 | void | |
4929 | linux_nat_set_forget_process (struct target_ops *t, | |
4930 | linux_nat_forget_process_ftype *fn) | |
4931 | { | |
4932 | /* Save the pointer. */ | |
4933 | linux_nat_forget_process_hook = fn; | |
4934 | } | |
4935 | ||
4936 | /* See declaration in linux-nat.h. */ | |
4937 | ||
4938 | void | |
4939 | linux_nat_forget_process (pid_t pid) | |
4940 | { | |
4941 | if (linux_nat_forget_process_hook != NULL) | |
4942 | linux_nat_forget_process_hook (pid); | |
4943 | } | |
4944 | ||
5b009018 PA |
4945 | /* Register a method that converts a siginfo object between the layout |
4946 | that ptrace returns, and the layout in the architecture of the | |
4947 | inferior. */ | |
4948 | void | |
4949 | linux_nat_set_siginfo_fixup (struct target_ops *t, | |
a5362b9a | 4950 | int (*siginfo_fixup) (siginfo_t *, |
5b009018 PA |
4951 | gdb_byte *, |
4952 | int)) | |
4953 | { | |
4954 | /* Save the pointer. */ | |
4955 | linux_nat_siginfo_fixup = siginfo_fixup; | |
4956 | } | |
4957 | ||
7b50312a PA |
4958 | /* Register a method to call prior to resuming a thread. */ |
4959 | ||
4960 | void | |
4961 | linux_nat_set_prepare_to_resume (struct target_ops *t, | |
4962 | void (*prepare_to_resume) (struct lwp_info *)) | |
4963 | { | |
4964 | /* Save the pointer. */ | |
4965 | linux_nat_prepare_to_resume = prepare_to_resume; | |
4966 | } | |
4967 | ||
f865ee35 JK |
4968 | /* See linux-nat.h. */ |
4969 | ||
4970 | int | |
4971 | linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo) | |
9f0bdab8 | 4972 | { |
da559b09 | 4973 | int pid; |
9f0bdab8 | 4974 | |
dfd4cc63 | 4975 | pid = ptid_get_lwp (ptid); |
da559b09 | 4976 | if (pid == 0) |
dfd4cc63 | 4977 | pid = ptid_get_pid (ptid); |
f865ee35 | 4978 | |
da559b09 JK |
4979 | errno = 0; |
4980 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo); | |
4981 | if (errno != 0) | |
4982 | { | |
4983 | memset (siginfo, 0, sizeof (*siginfo)); | |
4984 | return 0; | |
4985 | } | |
f865ee35 | 4986 | return 1; |
9f0bdab8 DJ |
4987 | } |
4988 | ||
7b669087 GB |
4989 | /* See nat/linux-nat.h. */ |
4990 | ||
4991 | ptid_t | |
4992 | current_lwp_ptid (void) | |
4993 | { | |
4994 | gdb_assert (ptid_lwp_p (inferior_ptid)); | |
4995 | return inferior_ptid; | |
4996 | } | |
4997 | ||
2c0b251b PA |
4998 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
4999 | extern initialize_file_ftype _initialize_linux_nat; | |
5000 | ||
d6b0e80f AC |
5001 | void |
5002 | _initialize_linux_nat (void) | |
5003 | { | |
ccce17b0 YQ |
5004 | add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance, |
5005 | &debug_linux_nat, _("\ | |
b84876c2 PA |
5006 | Set debugging of GNU/Linux lwp module."), _("\ |
5007 | Show debugging of GNU/Linux lwp module."), _("\ | |
5008 | Enables printf debugging output."), | |
ccce17b0 YQ |
5009 | NULL, |
5010 | show_debug_linux_nat, | |
5011 | &setdebuglist, &showdebuglist); | |
b84876c2 | 5012 | |
b84876c2 | 5013 | /* Save this mask as the default. */ |
d6b0e80f AC |
5014 | sigprocmask (SIG_SETMASK, NULL, &normal_mask); |
5015 | ||
7feb7d06 PA |
5016 | /* Install a SIGCHLD handler. */ |
5017 | sigchld_action.sa_handler = sigchld_handler; | |
5018 | sigemptyset (&sigchld_action.sa_mask); | |
5019 | sigchld_action.sa_flags = SA_RESTART; | |
b84876c2 PA |
5020 | |
5021 | /* Make it the default. */ | |
7feb7d06 | 5022 | sigaction (SIGCHLD, &sigchld_action, NULL); |
d6b0e80f AC |
5023 | |
5024 | /* Make sure we don't block SIGCHLD during a sigsuspend. */ | |
5025 | sigprocmask (SIG_SETMASK, NULL, &suspend_mask); | |
5026 | sigdelset (&suspend_mask, SIGCHLD); | |
5027 | ||
7feb7d06 | 5028 | sigemptyset (&blocked_mask); |
8009206a TT |
5029 | |
5030 | /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to | |
5031 | support read-only process state. */ | |
5032 | linux_ptrace_set_additional_flags (PTRACE_O_TRACESYSGOOD | |
5033 | | PTRACE_O_TRACEVFORKDONE | |
5034 | | PTRACE_O_TRACEVFORK | |
5035 | | PTRACE_O_TRACEFORK | |
5036 | | PTRACE_O_TRACEEXEC); | |
d6b0e80f AC |
5037 | } |
5038 | \f | |
5039 | ||
5040 | /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to | |
5041 | the GNU/Linux Threads library and therefore doesn't really belong | |
5042 | here. */ | |
5043 | ||
5044 | /* Read variable NAME in the target and return its value if found. | |
5045 | Otherwise return zero. It is assumed that the type of the variable | |
5046 | is `int'. */ | |
5047 | ||
5048 | static int | |
5049 | get_signo (const char *name) | |
5050 | { | |
3b7344d5 | 5051 | struct bound_minimal_symbol ms; |
d6b0e80f AC |
5052 | int signo; |
5053 | ||
5054 | ms = lookup_minimal_symbol (name, NULL, NULL); | |
3b7344d5 | 5055 | if (ms.minsym == NULL) |
d6b0e80f AC |
5056 | return 0; |
5057 | ||
77e371c0 | 5058 | if (target_read_memory (BMSYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo, |
d6b0e80f AC |
5059 | sizeof (signo)) != 0) |
5060 | return 0; | |
5061 | ||
5062 | return signo; | |
5063 | } | |
5064 | ||
5065 | /* Return the set of signals used by the threads library in *SET. */ | |
5066 | ||
5067 | void | |
5068 | lin_thread_get_thread_signals (sigset_t *set) | |
5069 | { | |
5070 | struct sigaction action; | |
5071 | int restart, cancel; | |
5072 | ||
b84876c2 | 5073 | sigemptyset (&blocked_mask); |
d6b0e80f AC |
5074 | sigemptyset (set); |
5075 | ||
5076 | restart = get_signo ("__pthread_sig_restart"); | |
17fbb0bd DJ |
5077 | cancel = get_signo ("__pthread_sig_cancel"); |
5078 | ||
5079 | /* LinuxThreads normally uses the first two RT signals, but in some legacy | |
5080 | cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does | |
5081 | not provide any way for the debugger to query the signal numbers - | |
5082 | fortunately they don't change! */ | |
5083 | ||
d6b0e80f | 5084 | if (restart == 0) |
17fbb0bd | 5085 | restart = __SIGRTMIN; |
d6b0e80f | 5086 | |
d6b0e80f | 5087 | if (cancel == 0) |
17fbb0bd | 5088 | cancel = __SIGRTMIN + 1; |
d6b0e80f AC |
5089 | |
5090 | sigaddset (set, restart); | |
5091 | sigaddset (set, cancel); | |
5092 | ||
5093 | /* The GNU/Linux Threads library makes terminating threads send a | |
5094 | special "cancel" signal instead of SIGCHLD. Make sure we catch | |
5095 | those (to prevent them from terminating GDB itself, which is | |
5096 | likely to be their default action) and treat them the same way as | |
5097 | SIGCHLD. */ | |
5098 | ||
5099 | action.sa_handler = sigchld_handler; | |
5100 | sigemptyset (&action.sa_mask); | |
58aecb61 | 5101 | action.sa_flags = SA_RESTART; |
d6b0e80f AC |
5102 | sigaction (cancel, &action, NULL); |
5103 | ||
5104 | /* We block the "cancel" signal throughout this code ... */ | |
5105 | sigaddset (&blocked_mask, cancel); | |
5106 | sigprocmask (SIG_BLOCK, &blocked_mask, NULL); | |
5107 | ||
5108 | /* ... except during a sigsuspend. */ | |
5109 | sigdelset (&suspend_mask, cancel); | |
5110 | } |