Commit | Line | Data |
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3993f6b1 | 1 | /* GNU/Linux native-dependent code common to multiple platforms. |
dba24537 | 2 | |
28e7fd62 | 3 | Copyright (C) 2001-2013 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" | |
22 | #include "target.h" | |
96d7229d LM |
23 | #include "nat/linux-nat.h" |
24 | #include "nat/linux-waitpid.h" | |
d6b0e80f | 25 | #include "gdb_string.h" |
3993f6b1 | 26 | #include "gdb_wait.h" |
d6b0e80f AC |
27 | #include "gdb_assert.h" |
28 | #ifdef HAVE_TKILL_SYSCALL | |
29 | #include <unistd.h> | |
30 | #include <sys/syscall.h> | |
31 | #endif | |
3993f6b1 | 32 | #include <sys/ptrace.h> |
0274a8ce | 33 | #include "linux-nat.h" |
af96c192 | 34 | #include "linux-ptrace.h" |
13da1c97 | 35 | #include "linux-procfs.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 */ | |
1777feb0 | 49 | #include "gdbthread.h" /* for struct thread_info etc. */ |
dba24537 AC |
50 | #include "gdb_stat.h" /* for struct stat */ |
51 | #include <fcntl.h> /* for O_RDONLY */ | |
b84876c2 PA |
52 | #include "inf-loop.h" |
53 | #include "event-loop.h" | |
54 | #include "event-top.h" | |
07e059b5 VP |
55 | #include <pwd.h> |
56 | #include <sys/types.h> | |
57 | #include "gdb_dirent.h" | |
58 | #include "xml-support.h" | |
191c4426 | 59 | #include "terminal.h" |
efcbbd14 | 60 | #include <sys/vfs.h> |
6c95b8df | 61 | #include "solib.h" |
d26e3629 | 62 | #include "linux-osdata.h" |
6432734d | 63 | #include "linux-tdep.h" |
7dcd53a0 | 64 | #include "symfile.h" |
5808517f YQ |
65 | #include "agent.h" |
66 | #include "tracepoint.h" | |
87b0bb13 JK |
67 | #include "exceptions.h" |
68 | #include "linux-ptrace.h" | |
69 | #include "buffer.h" | |
6ecd4729 | 70 | #include "target-descriptions.h" |
614c279d | 71 | #include "filestuff.h" |
efcbbd14 UW |
72 | |
73 | #ifndef SPUFS_MAGIC | |
74 | #define SPUFS_MAGIC 0x23c9b64e | |
75 | #endif | |
dba24537 | 76 | |
10568435 JK |
77 | #ifdef HAVE_PERSONALITY |
78 | # include <sys/personality.h> | |
79 | # if !HAVE_DECL_ADDR_NO_RANDOMIZE | |
80 | # define ADDR_NO_RANDOMIZE 0x0040000 | |
81 | # endif | |
82 | #endif /* HAVE_PERSONALITY */ | |
83 | ||
1777feb0 | 84 | /* This comment documents high-level logic of this file. |
8a77dff3 VP |
85 | |
86 | Waiting for events in sync mode | |
87 | =============================== | |
88 | ||
89 | When waiting for an event in a specific thread, we just use waitpid, passing | |
90 | the specific pid, and not passing WNOHANG. | |
91 | ||
1777feb0 | 92 | When waiting for an event in all threads, waitpid is not quite good. Prior to |
8a77dff3 | 93 | version 2.4, Linux can either wait for event in main thread, or in secondary |
1777feb0 | 94 | threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might |
8a77dff3 VP |
95 | miss an event. The solution is to use non-blocking waitpid, together with |
96 | sigsuspend. First, we use non-blocking waitpid to get an event in the main | |
1777feb0 | 97 | process, if any. Second, we use non-blocking waitpid with the __WCLONED |
8a77dff3 VP |
98 | flag to check for events in cloned processes. If nothing is found, we use |
99 | sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something | |
100 | happened to a child process -- and SIGCHLD will be delivered both for events | |
101 | in main debugged process and in cloned processes. As soon as we know there's | |
3e43a32a MS |
102 | an event, we get back to calling nonblocking waitpid with and without |
103 | __WCLONED. | |
8a77dff3 VP |
104 | |
105 | Note that SIGCHLD should be blocked between waitpid and sigsuspend calls, | |
1777feb0 | 106 | so that we don't miss a signal. If SIGCHLD arrives in between, when it's |
8a77dff3 VP |
107 | blocked, the signal becomes pending and sigsuspend immediately |
108 | notices it and returns. | |
109 | ||
110 | Waiting for events in async mode | |
111 | ================================ | |
112 | ||
7feb7d06 PA |
113 | In async mode, GDB should always be ready to handle both user input |
114 | and target events, so neither blocking waitpid nor sigsuspend are | |
115 | viable options. Instead, we should asynchronously notify the GDB main | |
116 | event loop whenever there's an unprocessed event from the target. We | |
117 | detect asynchronous target events by handling SIGCHLD signals. To | |
118 | notify the event loop about target events, the self-pipe trick is used | |
119 | --- a pipe is registered as waitable event source in the event loop, | |
120 | the event loop select/poll's on the read end of this pipe (as well on | |
121 | other event sources, e.g., stdin), and the SIGCHLD handler writes a | |
122 | byte to this pipe. This is more portable than relying on | |
123 | pselect/ppoll, since on kernels that lack those syscalls, libc | |
124 | emulates them with select/poll+sigprocmask, and that is racy | |
125 | (a.k.a. plain broken). | |
126 | ||
127 | Obviously, if we fail to notify the event loop if there's a target | |
128 | event, it's bad. OTOH, if we notify the event loop when there's no | |
129 | event from the target, linux_nat_wait will detect that there's no real | |
130 | event to report, and return event of type TARGET_WAITKIND_IGNORE. | |
131 | This is mostly harmless, but it will waste time and is better avoided. | |
132 | ||
133 | The main design point is that every time GDB is outside linux-nat.c, | |
134 | we have a SIGCHLD handler installed that is called when something | |
135 | happens to the target and notifies the GDB event loop. Whenever GDB | |
136 | core decides to handle the event, and calls into linux-nat.c, we | |
137 | process things as in sync mode, except that the we never block in | |
138 | sigsuspend. | |
139 | ||
140 | While processing an event, we may end up momentarily blocked in | |
141 | waitpid calls. Those waitpid calls, while blocking, are guarantied to | |
142 | return quickly. E.g., in all-stop mode, before reporting to the core | |
143 | that an LWP hit a breakpoint, all LWPs are stopped by sending them | |
144 | SIGSTOP, and synchronously waiting for the SIGSTOP to be reported. | |
145 | Note that this is different from blocking indefinitely waiting for the | |
146 | next event --- here, we're already handling an event. | |
8a77dff3 VP |
147 | |
148 | Use of signals | |
149 | ============== | |
150 | ||
151 | We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another | |
152 | signal is not entirely significant; we just need for a signal to be delivered, | |
153 | so that we can intercept it. SIGSTOP's advantage is that it can not be | |
154 | blocked. A disadvantage is that it is not a real-time signal, so it can only | |
155 | be queued once; we do not keep track of other sources of SIGSTOP. | |
156 | ||
157 | Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't | |
158 | use them, because they have special behavior when the signal is generated - | |
159 | not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL | |
160 | kills the entire thread group. | |
161 | ||
162 | A delivered SIGSTOP would stop the entire thread group, not just the thread we | |
163 | tkill'd. But we never let the SIGSTOP be delivered; we always intercept and | |
164 | cancel it (by PTRACE_CONT without passing SIGSTOP). | |
165 | ||
166 | We could use a real-time signal instead. This would solve those problems; we | |
167 | could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB. | |
168 | But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH | |
169 | generates it, and there are races with trying to find a signal that is not | |
170 | blocked. */ | |
a0ef4274 | 171 | |
dba24537 AC |
172 | #ifndef O_LARGEFILE |
173 | #define O_LARGEFILE 0 | |
174 | #endif | |
0274a8ce | 175 | |
10d6c8cd DJ |
176 | /* The single-threaded native GNU/Linux target_ops. We save a pointer for |
177 | the use of the multi-threaded target. */ | |
178 | static struct target_ops *linux_ops; | |
f973ed9c | 179 | static struct target_ops linux_ops_saved; |
10d6c8cd | 180 | |
9f0bdab8 | 181 | /* The method to call, if any, when a new thread is attached. */ |
7b50312a PA |
182 | static void (*linux_nat_new_thread) (struct lwp_info *); |
183 | ||
26cb8b7c PA |
184 | /* The method to call, if any, when a new fork is attached. */ |
185 | static linux_nat_new_fork_ftype *linux_nat_new_fork; | |
186 | ||
187 | /* The method to call, if any, when a process is no longer | |
188 | attached. */ | |
189 | static linux_nat_forget_process_ftype *linux_nat_forget_process_hook; | |
190 | ||
7b50312a PA |
191 | /* Hook to call prior to resuming a thread. */ |
192 | static void (*linux_nat_prepare_to_resume) (struct lwp_info *); | |
9f0bdab8 | 193 | |
5b009018 PA |
194 | /* The method to call, if any, when the siginfo object needs to be |
195 | converted between the layout returned by ptrace, and the layout in | |
196 | the architecture of the inferior. */ | |
a5362b9a | 197 | static int (*linux_nat_siginfo_fixup) (siginfo_t *, |
5b009018 PA |
198 | gdb_byte *, |
199 | int); | |
200 | ||
ac264b3b MS |
201 | /* The saved to_xfer_partial method, inherited from inf-ptrace.c. |
202 | Called by our to_xfer_partial. */ | |
203 | static LONGEST (*super_xfer_partial) (struct target_ops *, | |
204 | enum target_object, | |
205 | const char *, gdb_byte *, | |
206 | const gdb_byte *, | |
10d6c8cd DJ |
207 | ULONGEST, LONGEST); |
208 | ||
ccce17b0 | 209 | static unsigned int debug_linux_nat; |
920d2a44 AC |
210 | static void |
211 | show_debug_linux_nat (struct ui_file *file, int from_tty, | |
212 | struct cmd_list_element *c, const char *value) | |
213 | { | |
214 | fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"), | |
215 | value); | |
216 | } | |
d6b0e80f | 217 | |
ae087d01 DJ |
218 | struct simple_pid_list |
219 | { | |
220 | int pid; | |
3d799a95 | 221 | int status; |
ae087d01 DJ |
222 | struct simple_pid_list *next; |
223 | }; | |
224 | struct simple_pid_list *stopped_pids; | |
225 | ||
3dd5b83d PA |
226 | /* Async mode support. */ |
227 | ||
b84876c2 PA |
228 | /* The read/write ends of the pipe registered as waitable file in the |
229 | event loop. */ | |
230 | static int linux_nat_event_pipe[2] = { -1, -1 }; | |
231 | ||
7feb7d06 | 232 | /* Flush the event pipe. */ |
b84876c2 | 233 | |
7feb7d06 PA |
234 | static void |
235 | async_file_flush (void) | |
b84876c2 | 236 | { |
7feb7d06 PA |
237 | int ret; |
238 | char buf; | |
b84876c2 | 239 | |
7feb7d06 | 240 | do |
b84876c2 | 241 | { |
7feb7d06 | 242 | ret = read (linux_nat_event_pipe[0], &buf, 1); |
b84876c2 | 243 | } |
7feb7d06 | 244 | while (ret >= 0 || (ret == -1 && errno == EINTR)); |
b84876c2 PA |
245 | } |
246 | ||
7feb7d06 PA |
247 | /* Put something (anything, doesn't matter what, or how much) in event |
248 | pipe, so that the select/poll in the event-loop realizes we have | |
249 | something to process. */ | |
252fbfc8 | 250 | |
b84876c2 | 251 | static void |
7feb7d06 | 252 | async_file_mark (void) |
b84876c2 | 253 | { |
7feb7d06 | 254 | int ret; |
b84876c2 | 255 | |
7feb7d06 PA |
256 | /* It doesn't really matter what the pipe contains, as long we end |
257 | up with something in it. Might as well flush the previous | |
258 | left-overs. */ | |
259 | async_file_flush (); | |
b84876c2 | 260 | |
7feb7d06 | 261 | do |
b84876c2 | 262 | { |
7feb7d06 | 263 | ret = write (linux_nat_event_pipe[1], "+", 1); |
b84876c2 | 264 | } |
7feb7d06 | 265 | while (ret == -1 && errno == EINTR); |
b84876c2 | 266 | |
7feb7d06 PA |
267 | /* Ignore EAGAIN. If the pipe is full, the event loop will already |
268 | be awakened anyway. */ | |
b84876c2 PA |
269 | } |
270 | ||
7feb7d06 | 271 | static void linux_nat_async (void (*callback) |
3e43a32a MS |
272 | (enum inferior_event_type event_type, |
273 | void *context), | |
7feb7d06 | 274 | void *context); |
7feb7d06 PA |
275 | static int kill_lwp (int lwpid, int signo); |
276 | ||
277 | static int stop_callback (struct lwp_info *lp, void *data); | |
278 | ||
279 | static void block_child_signals (sigset_t *prev_mask); | |
280 | static void restore_child_signals_mask (sigset_t *prev_mask); | |
2277426b PA |
281 | |
282 | struct lwp_info; | |
283 | static struct lwp_info *add_lwp (ptid_t ptid); | |
284 | static void purge_lwp_list (int pid); | |
4403d8e9 | 285 | static void delete_lwp (ptid_t ptid); |
2277426b PA |
286 | static struct lwp_info *find_lwp_pid (ptid_t ptid); |
287 | ||
ae087d01 DJ |
288 | \f |
289 | /* Trivial list manipulation functions to keep track of a list of | |
290 | new stopped processes. */ | |
291 | static void | |
3d799a95 | 292 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
ae087d01 DJ |
293 | { |
294 | struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list)); | |
e0881a8e | 295 | |
ae087d01 | 296 | new_pid->pid = pid; |
3d799a95 | 297 | new_pid->status = status; |
ae087d01 DJ |
298 | new_pid->next = *listp; |
299 | *listp = new_pid; | |
300 | } | |
301 | ||
84636d28 PA |
302 | static int |
303 | in_pid_list_p (struct simple_pid_list *list, int pid) | |
304 | { | |
305 | struct simple_pid_list *p; | |
306 | ||
307 | for (p = list; p != NULL; p = p->next) | |
308 | if (p->pid == pid) | |
309 | return 1; | |
310 | return 0; | |
311 | } | |
312 | ||
ae087d01 | 313 | static int |
46a96992 | 314 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
ae087d01 DJ |
315 | { |
316 | struct simple_pid_list **p; | |
317 | ||
318 | for (p = listp; *p != NULL; p = &(*p)->next) | |
319 | if ((*p)->pid == pid) | |
320 | { | |
321 | struct simple_pid_list *next = (*p)->next; | |
e0881a8e | 322 | |
46a96992 | 323 | *statusp = (*p)->status; |
ae087d01 DJ |
324 | xfree (*p); |
325 | *p = next; | |
326 | return 1; | |
327 | } | |
328 | return 0; | |
329 | } | |
330 | ||
96d7229d LM |
331 | /* Initialize ptrace warnings and check for supported ptrace |
332 | features given PID. */ | |
3993f6b1 DJ |
333 | |
334 | static void | |
96d7229d | 335 | linux_init_ptrace (pid_t pid) |
3993f6b1 | 336 | { |
96d7229d LM |
337 | linux_enable_event_reporting (pid); |
338 | linux_ptrace_init_warnings (); | |
4de4c07c DJ |
339 | } |
340 | ||
6d8fd2b7 UW |
341 | static void |
342 | linux_child_post_attach (int pid) | |
4de4c07c | 343 | { |
96d7229d | 344 | linux_init_ptrace (pid); |
4de4c07c DJ |
345 | } |
346 | ||
10d6c8cd | 347 | static void |
4de4c07c DJ |
348 | linux_child_post_startup_inferior (ptid_t ptid) |
349 | { | |
96d7229d | 350 | linux_init_ptrace (ptid_get_pid (ptid)); |
4de4c07c DJ |
351 | } |
352 | ||
4403d8e9 JK |
353 | /* Return the number of known LWPs in the tgid given by PID. */ |
354 | ||
355 | static int | |
356 | num_lwps (int pid) | |
357 | { | |
358 | int count = 0; | |
359 | struct lwp_info *lp; | |
360 | ||
361 | for (lp = lwp_list; lp; lp = lp->next) | |
362 | if (ptid_get_pid (lp->ptid) == pid) | |
363 | count++; | |
364 | ||
365 | return count; | |
366 | } | |
367 | ||
368 | /* Call delete_lwp with prototype compatible for make_cleanup. */ | |
369 | ||
370 | static void | |
371 | delete_lwp_cleanup (void *lp_voidp) | |
372 | { | |
373 | struct lwp_info *lp = lp_voidp; | |
374 | ||
375 | delete_lwp (lp->ptid); | |
376 | } | |
377 | ||
6d8fd2b7 | 378 | static int |
07107ca6 LM |
379 | linux_child_follow_fork (struct target_ops *ops, int follow_child, |
380 | int detach_fork) | |
3993f6b1 | 381 | { |
9016a515 | 382 | int has_vforked; |
4de4c07c DJ |
383 | int parent_pid, child_pid; |
384 | ||
e58b0e63 PA |
385 | has_vforked = (inferior_thread ()->pending_follow.kind |
386 | == TARGET_WAITKIND_VFORKED); | |
387 | parent_pid = ptid_get_lwp (inferior_ptid); | |
d3587048 | 388 | if (parent_pid == 0) |
e58b0e63 PA |
389 | parent_pid = ptid_get_pid (inferior_ptid); |
390 | child_pid = PIDGET (inferior_thread ()->pending_follow.value.related_pid); | |
4de4c07c | 391 | |
6c95b8df PA |
392 | if (has_vforked |
393 | && !non_stop /* Non-stop always resumes both branches. */ | |
394 | && (!target_is_async_p () || sync_execution) | |
395 | && !(follow_child || detach_fork || sched_multi)) | |
396 | { | |
397 | /* The parent stays blocked inside the vfork syscall until the | |
398 | child execs or exits. If we don't let the child run, then | |
399 | the parent stays blocked. If we're telling the parent to run | |
400 | in the foreground, the user will not be able to ctrl-c to get | |
401 | back the terminal, effectively hanging the debug session. */ | |
ac74f770 MS |
402 | fprintf_filtered (gdb_stderr, _("\ |
403 | Can not resume the parent process over vfork in the foreground while\n\ | |
404 | holding the child stopped. Try \"set detach-on-fork\" or \ | |
405 | \"set schedule-multiple\".\n")); | |
406 | /* FIXME output string > 80 columns. */ | |
6c95b8df PA |
407 | return 1; |
408 | } | |
409 | ||
4de4c07c DJ |
410 | if (! follow_child) |
411 | { | |
6c95b8df | 412 | struct lwp_info *child_lp = NULL; |
4de4c07c | 413 | |
1777feb0 | 414 | /* We're already attached to the parent, by default. */ |
4de4c07c | 415 | |
ac264b3b MS |
416 | /* Detach new forked process? */ |
417 | if (detach_fork) | |
f75c00e4 | 418 | { |
4403d8e9 JK |
419 | struct cleanup *old_chain; |
420 | ||
6c95b8df PA |
421 | /* Before detaching from the child, remove all breakpoints |
422 | from it. If we forked, then this has already been taken | |
423 | care of by infrun.c. If we vforked however, any | |
424 | breakpoint inserted in the parent is visible in the | |
425 | child, even those added while stopped in a vfork | |
426 | catchpoint. This will remove the breakpoints from the | |
427 | parent also, but they'll be reinserted below. */ | |
428 | if (has_vforked) | |
429 | { | |
430 | /* keep breakpoints list in sync. */ | |
431 | remove_breakpoints_pid (GET_PID (inferior_ptid)); | |
432 | } | |
433 | ||
e85a822c | 434 | if (info_verbose || debug_linux_nat) |
ac264b3b MS |
435 | { |
436 | target_terminal_ours (); | |
437 | fprintf_filtered (gdb_stdlog, | |
3e43a32a MS |
438 | "Detaching after fork from " |
439 | "child process %d.\n", | |
ac264b3b MS |
440 | child_pid); |
441 | } | |
4de4c07c | 442 | |
4403d8e9 JK |
443 | old_chain = save_inferior_ptid (); |
444 | inferior_ptid = ptid_build (child_pid, child_pid, 0); | |
445 | ||
446 | child_lp = add_lwp (inferior_ptid); | |
447 | child_lp->stopped = 1; | |
448 | child_lp->last_resume_kind = resume_stop; | |
449 | make_cleanup (delete_lwp_cleanup, child_lp); | |
450 | ||
4403d8e9 JK |
451 | if (linux_nat_prepare_to_resume != NULL) |
452 | linux_nat_prepare_to_resume (child_lp); | |
ac264b3b | 453 | ptrace (PTRACE_DETACH, child_pid, 0, 0); |
4403d8e9 JK |
454 | |
455 | do_cleanups (old_chain); | |
ac264b3b MS |
456 | } |
457 | else | |
458 | { | |
77435e4c | 459 | struct inferior *parent_inf, *child_inf; |
2277426b | 460 | struct cleanup *old_chain; |
7f9f62ba PA |
461 | |
462 | /* Add process to GDB's tables. */ | |
77435e4c PA |
463 | child_inf = add_inferior (child_pid); |
464 | ||
e58b0e63 | 465 | parent_inf = current_inferior (); |
77435e4c | 466 | child_inf->attach_flag = parent_inf->attach_flag; |
191c4426 | 467 | copy_terminal_info (child_inf, parent_inf); |
6ecd4729 PA |
468 | child_inf->gdbarch = parent_inf->gdbarch; |
469 | copy_inferior_target_desc_info (child_inf, parent_inf); | |
7f9f62ba | 470 | |
2277426b | 471 | old_chain = save_inferior_ptid (); |
6c95b8df | 472 | save_current_program_space (); |
2277426b PA |
473 | |
474 | inferior_ptid = ptid_build (child_pid, child_pid, 0); | |
475 | add_thread (inferior_ptid); | |
6c95b8df PA |
476 | child_lp = add_lwp (inferior_ptid); |
477 | child_lp->stopped = 1; | |
25289eb2 | 478 | child_lp->last_resume_kind = resume_stop; |
7dcd53a0 | 479 | child_inf->symfile_flags = SYMFILE_NO_READ; |
2277426b | 480 | |
6c95b8df PA |
481 | /* If this is a vfork child, then the address-space is |
482 | shared with the parent. */ | |
483 | if (has_vforked) | |
484 | { | |
485 | child_inf->pspace = parent_inf->pspace; | |
486 | child_inf->aspace = parent_inf->aspace; | |
487 | ||
488 | /* The parent will be frozen until the child is done | |
489 | with the shared region. Keep track of the | |
490 | parent. */ | |
491 | child_inf->vfork_parent = parent_inf; | |
492 | child_inf->pending_detach = 0; | |
493 | parent_inf->vfork_child = child_inf; | |
494 | parent_inf->pending_detach = 0; | |
495 | } | |
496 | else | |
497 | { | |
498 | child_inf->aspace = new_address_space (); | |
499 | child_inf->pspace = add_program_space (child_inf->aspace); | |
500 | child_inf->removable = 1; | |
501 | set_current_program_space (child_inf->pspace); | |
502 | clone_program_space (child_inf->pspace, parent_inf->pspace); | |
503 | ||
504 | /* Let the shared library layer (solib-svr4) learn about | |
505 | this new process, relocate the cloned exec, pull in | |
506 | shared libraries, and install the solib event | |
507 | breakpoint. If a "cloned-VM" event was propagated | |
508 | better throughout the core, this wouldn't be | |
509 | required. */ | |
268a4a75 | 510 | solib_create_inferior_hook (0); |
6c95b8df PA |
511 | } |
512 | ||
513 | /* Let the thread_db layer learn about this new process. */ | |
2277426b PA |
514 | check_for_thread_db (); |
515 | ||
516 | do_cleanups (old_chain); | |
ac264b3b | 517 | } |
9016a515 DJ |
518 | |
519 | if (has_vforked) | |
520 | { | |
3ced3da4 | 521 | struct lwp_info *parent_lp; |
6c95b8df PA |
522 | struct inferior *parent_inf; |
523 | ||
524 | parent_inf = current_inferior (); | |
525 | ||
526 | /* If we detached from the child, then we have to be careful | |
527 | to not insert breakpoints in the parent until the child | |
528 | is done with the shared memory region. However, if we're | |
529 | staying attached to the child, then we can and should | |
530 | insert breakpoints, so that we can debug it. A | |
531 | subsequent child exec or exit is enough to know when does | |
532 | the child stops using the parent's address space. */ | |
533 | parent_inf->waiting_for_vfork_done = detach_fork; | |
56710373 | 534 | parent_inf->pspace->breakpoints_not_allowed = detach_fork; |
6c95b8df | 535 | |
3ced3da4 | 536 | parent_lp = find_lwp_pid (pid_to_ptid (parent_pid)); |
96d7229d | 537 | gdb_assert (linux_supports_tracefork () >= 0); |
3ced3da4 | 538 | |
96d7229d | 539 | if (linux_supports_tracevforkdone ()) |
9016a515 | 540 | { |
6c95b8df PA |
541 | if (debug_linux_nat) |
542 | fprintf_unfiltered (gdb_stdlog, | |
543 | "LCFF: waiting for VFORK_DONE on %d\n", | |
544 | parent_pid); | |
3ced3da4 | 545 | parent_lp->stopped = 1; |
9016a515 | 546 | |
6c95b8df PA |
547 | /* We'll handle the VFORK_DONE event like any other |
548 | event, in target_wait. */ | |
9016a515 DJ |
549 | } |
550 | else | |
551 | { | |
552 | /* We can't insert breakpoints until the child has | |
553 | finished with the shared memory region. We need to | |
554 | wait until that happens. Ideal would be to just | |
555 | call: | |
556 | - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0); | |
557 | - waitpid (parent_pid, &status, __WALL); | |
558 | However, most architectures can't handle a syscall | |
559 | being traced on the way out if it wasn't traced on | |
560 | the way in. | |
561 | ||
562 | We might also think to loop, continuing the child | |
563 | until it exits or gets a SIGTRAP. One problem is | |
564 | that the child might call ptrace with PTRACE_TRACEME. | |
565 | ||
566 | There's no simple and reliable way to figure out when | |
567 | the vforked child will be done with its copy of the | |
568 | shared memory. We could step it out of the syscall, | |
569 | two instructions, let it go, and then single-step the | |
570 | parent once. When we have hardware single-step, this | |
571 | would work; with software single-step it could still | |
572 | be made to work but we'd have to be able to insert | |
573 | single-step breakpoints in the child, and we'd have | |
574 | to insert -just- the single-step breakpoint in the | |
575 | parent. Very awkward. | |
576 | ||
577 | In the end, the best we can do is to make sure it | |
578 | runs for a little while. Hopefully it will be out of | |
579 | range of any breakpoints we reinsert. Usually this | |
580 | is only the single-step breakpoint at vfork's return | |
581 | point. */ | |
582 | ||
6c95b8df PA |
583 | if (debug_linux_nat) |
584 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
585 | "LCFF: no VFORK_DONE " |
586 | "support, sleeping a bit\n"); | |
6c95b8df | 587 | |
9016a515 | 588 | usleep (10000); |
9016a515 | 589 | |
6c95b8df PA |
590 | /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event, |
591 | and leave it pending. The next linux_nat_resume call | |
592 | will notice a pending event, and bypasses actually | |
593 | resuming the inferior. */ | |
3ced3da4 PA |
594 | parent_lp->status = 0; |
595 | parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE; | |
596 | parent_lp->stopped = 1; | |
6c95b8df PA |
597 | |
598 | /* If we're in async mode, need to tell the event loop | |
599 | there's something here to process. */ | |
600 | if (target_can_async_p ()) | |
601 | async_file_mark (); | |
602 | } | |
9016a515 | 603 | } |
4de4c07c | 604 | } |
3993f6b1 | 605 | else |
4de4c07c | 606 | { |
77435e4c | 607 | struct inferior *parent_inf, *child_inf; |
3ced3da4 | 608 | struct lwp_info *child_lp; |
6c95b8df | 609 | struct program_space *parent_pspace; |
4de4c07c | 610 | |
e85a822c | 611 | if (info_verbose || debug_linux_nat) |
f75c00e4 DJ |
612 | { |
613 | target_terminal_ours (); | |
6c95b8df | 614 | if (has_vforked) |
3e43a32a MS |
615 | fprintf_filtered (gdb_stdlog, |
616 | _("Attaching after process %d " | |
617 | "vfork to child process %d.\n"), | |
6c95b8df PA |
618 | parent_pid, child_pid); |
619 | else | |
3e43a32a MS |
620 | fprintf_filtered (gdb_stdlog, |
621 | _("Attaching after process %d " | |
622 | "fork to child process %d.\n"), | |
6c95b8df | 623 | parent_pid, child_pid); |
f75c00e4 | 624 | } |
4de4c07c | 625 | |
7a7d3353 PA |
626 | /* Add the new inferior first, so that the target_detach below |
627 | doesn't unpush the target. */ | |
628 | ||
77435e4c PA |
629 | child_inf = add_inferior (child_pid); |
630 | ||
e58b0e63 | 631 | parent_inf = current_inferior (); |
77435e4c | 632 | child_inf->attach_flag = parent_inf->attach_flag; |
191c4426 | 633 | copy_terminal_info (child_inf, parent_inf); |
6ecd4729 PA |
634 | child_inf->gdbarch = parent_inf->gdbarch; |
635 | copy_inferior_target_desc_info (child_inf, parent_inf); | |
7a7d3353 | 636 | |
6c95b8df | 637 | parent_pspace = parent_inf->pspace; |
9016a515 | 638 | |
6c95b8df PA |
639 | /* If we're vforking, we want to hold on to the parent until the |
640 | child exits or execs. At child exec or exit time we can | |
641 | remove the old breakpoints from the parent and detach or | |
642 | resume debugging it. Otherwise, detach the parent now; we'll | |
643 | want to reuse it's program/address spaces, but we can't set | |
644 | them to the child before removing breakpoints from the | |
645 | parent, otherwise, the breakpoints module could decide to | |
646 | remove breakpoints from the wrong process (since they'd be | |
647 | assigned to the same address space). */ | |
9016a515 DJ |
648 | |
649 | if (has_vforked) | |
7f9f62ba | 650 | { |
6c95b8df PA |
651 | gdb_assert (child_inf->vfork_parent == NULL); |
652 | gdb_assert (parent_inf->vfork_child == NULL); | |
653 | child_inf->vfork_parent = parent_inf; | |
654 | child_inf->pending_detach = 0; | |
655 | parent_inf->vfork_child = child_inf; | |
656 | parent_inf->pending_detach = detach_fork; | |
657 | parent_inf->waiting_for_vfork_done = 0; | |
ac264b3b | 658 | } |
2277426b | 659 | else if (detach_fork) |
b84876c2 | 660 | target_detach (NULL, 0); |
4de4c07c | 661 | |
6c95b8df PA |
662 | /* Note that the detach above makes PARENT_INF dangling. */ |
663 | ||
664 | /* Add the child thread to the appropriate lists, and switch to | |
665 | this new thread, before cloning the program space, and | |
666 | informing the solib layer about this new process. */ | |
667 | ||
9f0bdab8 | 668 | inferior_ptid = ptid_build (child_pid, child_pid, 0); |
2277426b | 669 | add_thread (inferior_ptid); |
3ced3da4 PA |
670 | child_lp = add_lwp (inferior_ptid); |
671 | child_lp->stopped = 1; | |
25289eb2 | 672 | child_lp->last_resume_kind = resume_stop; |
6c95b8df PA |
673 | |
674 | /* If this is a vfork child, then the address-space is shared | |
675 | with the parent. If we detached from the parent, then we can | |
676 | reuse the parent's program/address spaces. */ | |
677 | if (has_vforked || detach_fork) | |
678 | { | |
679 | child_inf->pspace = parent_pspace; | |
680 | child_inf->aspace = child_inf->pspace->aspace; | |
681 | } | |
682 | else | |
683 | { | |
684 | child_inf->aspace = new_address_space (); | |
685 | child_inf->pspace = add_program_space (child_inf->aspace); | |
686 | child_inf->removable = 1; | |
7dcd53a0 | 687 | child_inf->symfile_flags = SYMFILE_NO_READ; |
6c95b8df PA |
688 | set_current_program_space (child_inf->pspace); |
689 | clone_program_space (child_inf->pspace, parent_pspace); | |
690 | ||
691 | /* Let the shared library layer (solib-svr4) learn about | |
692 | this new process, relocate the cloned exec, pull in | |
693 | shared libraries, and install the solib event breakpoint. | |
694 | If a "cloned-VM" event was propagated better throughout | |
695 | the core, this wouldn't be required. */ | |
268a4a75 | 696 | solib_create_inferior_hook (0); |
6c95b8df | 697 | } |
ac264b3b | 698 | |
6c95b8df | 699 | /* Let the thread_db layer learn about this new process. */ |
ef29ce1a | 700 | check_for_thread_db (); |
4de4c07c DJ |
701 | } |
702 | ||
703 | return 0; | |
704 | } | |
705 | ||
4de4c07c | 706 | \f |
77b06cd7 | 707 | static int |
6d8fd2b7 | 708 | linux_child_insert_fork_catchpoint (int pid) |
4de4c07c | 709 | { |
96d7229d | 710 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
711 | } |
712 | ||
eb73ad13 PA |
713 | static int |
714 | linux_child_remove_fork_catchpoint (int pid) | |
715 | { | |
716 | return 0; | |
717 | } | |
718 | ||
77b06cd7 | 719 | static int |
6d8fd2b7 | 720 | linux_child_insert_vfork_catchpoint (int pid) |
3993f6b1 | 721 | { |
96d7229d | 722 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
723 | } |
724 | ||
eb73ad13 PA |
725 | static int |
726 | linux_child_remove_vfork_catchpoint (int pid) | |
727 | { | |
728 | return 0; | |
729 | } | |
730 | ||
77b06cd7 | 731 | static int |
6d8fd2b7 | 732 | linux_child_insert_exec_catchpoint (int pid) |
3993f6b1 | 733 | { |
96d7229d | 734 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
735 | } |
736 | ||
eb73ad13 PA |
737 | static int |
738 | linux_child_remove_exec_catchpoint (int pid) | |
739 | { | |
740 | return 0; | |
741 | } | |
742 | ||
a96d9b2e SDJ |
743 | static int |
744 | linux_child_set_syscall_catchpoint (int pid, int needed, int any_count, | |
745 | int table_size, int *table) | |
746 | { | |
96d7229d | 747 | if (!linux_supports_tracesysgood ()) |
77b06cd7 TJB |
748 | return 1; |
749 | ||
a96d9b2e SDJ |
750 | /* On GNU/Linux, we ignore the arguments. It means that we only |
751 | enable the syscall catchpoints, but do not disable them. | |
77b06cd7 | 752 | |
a96d9b2e SDJ |
753 | Also, we do not use the `table' information because we do not |
754 | filter system calls here. We let GDB do the logic for us. */ | |
755 | return 0; | |
756 | } | |
757 | ||
d6b0e80f AC |
758 | /* On GNU/Linux there are no real LWP's. The closest thing to LWP's |
759 | are processes sharing the same VM space. A multi-threaded process | |
760 | is basically a group of such processes. However, such a grouping | |
761 | is almost entirely a user-space issue; the kernel doesn't enforce | |
762 | such a grouping at all (this might change in the future). In | |
763 | general, we'll rely on the threads library (i.e. the GNU/Linux | |
764 | Threads library) to provide such a grouping. | |
765 | ||
766 | It is perfectly well possible to write a multi-threaded application | |
767 | without the assistance of a threads library, by using the clone | |
768 | system call directly. This module should be able to give some | |
769 | rudimentary support for debugging such applications if developers | |
770 | specify the CLONE_PTRACE flag in the clone system call, and are | |
771 | using the Linux kernel 2.4 or above. | |
772 | ||
773 | Note that there are some peculiarities in GNU/Linux that affect | |
774 | this code: | |
775 | ||
776 | - In general one should specify the __WCLONE flag to waitpid in | |
777 | order to make it report events for any of the cloned processes | |
778 | (and leave it out for the initial process). However, if a cloned | |
779 | process has exited the exit status is only reported if the | |
780 | __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but | |
781 | we cannot use it since GDB must work on older systems too. | |
782 | ||
783 | - When a traced, cloned process exits and is waited for by the | |
784 | debugger, the kernel reassigns it to the original parent and | |
785 | keeps it around as a "zombie". Somehow, the GNU/Linux Threads | |
786 | library doesn't notice this, which leads to the "zombie problem": | |
787 | When debugged a multi-threaded process that spawns a lot of | |
788 | threads will run out of processes, even if the threads exit, | |
789 | because the "zombies" stay around. */ | |
790 | ||
791 | /* List of known LWPs. */ | |
9f0bdab8 | 792 | struct lwp_info *lwp_list; |
d6b0e80f AC |
793 | \f |
794 | ||
d6b0e80f AC |
795 | /* Original signal mask. */ |
796 | static sigset_t normal_mask; | |
797 | ||
798 | /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in | |
799 | _initialize_linux_nat. */ | |
800 | static sigset_t suspend_mask; | |
801 | ||
7feb7d06 PA |
802 | /* Signals to block to make that sigsuspend work. */ |
803 | static sigset_t blocked_mask; | |
804 | ||
805 | /* SIGCHLD action. */ | |
806 | struct sigaction sigchld_action; | |
b84876c2 | 807 | |
7feb7d06 PA |
808 | /* Block child signals (SIGCHLD and linux threads signals), and store |
809 | the previous mask in PREV_MASK. */ | |
84e46146 | 810 | |
7feb7d06 PA |
811 | static void |
812 | block_child_signals (sigset_t *prev_mask) | |
813 | { | |
814 | /* Make sure SIGCHLD is blocked. */ | |
815 | if (!sigismember (&blocked_mask, SIGCHLD)) | |
816 | sigaddset (&blocked_mask, SIGCHLD); | |
817 | ||
818 | sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask); | |
819 | } | |
820 | ||
821 | /* Restore child signals mask, previously returned by | |
822 | block_child_signals. */ | |
823 | ||
824 | static void | |
825 | restore_child_signals_mask (sigset_t *prev_mask) | |
826 | { | |
827 | sigprocmask (SIG_SETMASK, prev_mask, NULL); | |
828 | } | |
2455069d UW |
829 | |
830 | /* Mask of signals to pass directly to the inferior. */ | |
831 | static sigset_t pass_mask; | |
832 | ||
833 | /* Update signals to pass to the inferior. */ | |
834 | static void | |
835 | linux_nat_pass_signals (int numsigs, unsigned char *pass_signals) | |
836 | { | |
837 | int signo; | |
838 | ||
839 | sigemptyset (&pass_mask); | |
840 | ||
841 | for (signo = 1; signo < NSIG; signo++) | |
842 | { | |
2ea28649 | 843 | int target_signo = gdb_signal_from_host (signo); |
2455069d UW |
844 | if (target_signo < numsigs && pass_signals[target_signo]) |
845 | sigaddset (&pass_mask, signo); | |
846 | } | |
847 | } | |
848 | ||
d6b0e80f AC |
849 | \f |
850 | ||
851 | /* Prototypes for local functions. */ | |
852 | static int stop_wait_callback (struct lwp_info *lp, void *data); | |
28439f5e | 853 | static int linux_thread_alive (ptid_t ptid); |
6d8fd2b7 | 854 | static char *linux_child_pid_to_exec_file (int pid); |
710151dd | 855 | |
d6b0e80f AC |
856 | \f |
857 | /* Convert wait status STATUS to a string. Used for printing debug | |
858 | messages only. */ | |
859 | ||
860 | static char * | |
861 | status_to_str (int status) | |
862 | { | |
863 | static char buf[64]; | |
864 | ||
865 | if (WIFSTOPPED (status)) | |
206aa767 | 866 | { |
ca2163eb | 867 | if (WSTOPSIG (status) == SYSCALL_SIGTRAP) |
206aa767 DE |
868 | snprintf (buf, sizeof (buf), "%s (stopped at syscall)", |
869 | strsignal (SIGTRAP)); | |
870 | else | |
871 | snprintf (buf, sizeof (buf), "%s (stopped)", | |
872 | strsignal (WSTOPSIG (status))); | |
873 | } | |
d6b0e80f AC |
874 | else if (WIFSIGNALED (status)) |
875 | snprintf (buf, sizeof (buf), "%s (terminated)", | |
ba9b2ec3 | 876 | strsignal (WTERMSIG (status))); |
d6b0e80f AC |
877 | else |
878 | snprintf (buf, sizeof (buf), "%d (exited)", WEXITSTATUS (status)); | |
879 | ||
880 | return buf; | |
881 | } | |
882 | ||
7b50312a PA |
883 | /* Destroy and free LP. */ |
884 | ||
885 | static void | |
886 | lwp_free (struct lwp_info *lp) | |
887 | { | |
888 | xfree (lp->arch_private); | |
889 | xfree (lp); | |
890 | } | |
891 | ||
d90e17a7 PA |
892 | /* Remove all LWPs belong to PID from the lwp list. */ |
893 | ||
894 | static void | |
895 | purge_lwp_list (int pid) | |
896 | { | |
897 | struct lwp_info *lp, *lpprev, *lpnext; | |
898 | ||
899 | lpprev = NULL; | |
900 | ||
901 | for (lp = lwp_list; lp; lp = lpnext) | |
902 | { | |
903 | lpnext = lp->next; | |
904 | ||
905 | if (ptid_get_pid (lp->ptid) == pid) | |
906 | { | |
907 | if (lp == lwp_list) | |
908 | lwp_list = lp->next; | |
909 | else | |
910 | lpprev->next = lp->next; | |
911 | ||
7b50312a | 912 | lwp_free (lp); |
d90e17a7 PA |
913 | } |
914 | else | |
915 | lpprev = lp; | |
916 | } | |
917 | } | |
918 | ||
26cb8b7c PA |
919 | /* Add the LWP specified by PTID to the list. PTID is the first LWP |
920 | in the process. Return a pointer to the structure describing the | |
921 | new LWP. | |
922 | ||
923 | This differs from add_lwp in that we don't let the arch specific | |
924 | bits know about this new thread. Current clients of this callback | |
925 | take the opportunity to install watchpoints in the new thread, and | |
926 | we shouldn't do that for the first thread. If we're spawning a | |
927 | child ("run"), the thread executes the shell wrapper first, and we | |
928 | shouldn't touch it until it execs the program we want to debug. | |
929 | For "attach", it'd be okay to call the callback, but it's not | |
930 | necessary, because watchpoints can't yet have been inserted into | |
931 | the inferior. */ | |
d6b0e80f AC |
932 | |
933 | static struct lwp_info * | |
26cb8b7c | 934 | add_initial_lwp (ptid_t ptid) |
d6b0e80f AC |
935 | { |
936 | struct lwp_info *lp; | |
937 | ||
938 | gdb_assert (is_lwp (ptid)); | |
939 | ||
940 | lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info)); | |
941 | ||
942 | memset (lp, 0, sizeof (struct lwp_info)); | |
943 | ||
25289eb2 | 944 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
945 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
946 | ||
947 | lp->ptid = ptid; | |
dc146f7c | 948 | lp->core = -1; |
d6b0e80f AC |
949 | |
950 | lp->next = lwp_list; | |
951 | lwp_list = lp; | |
d6b0e80f | 952 | |
26cb8b7c PA |
953 | return lp; |
954 | } | |
955 | ||
956 | /* Add the LWP specified by PID to the list. Return a pointer to the | |
957 | structure describing the new LWP. The LWP should already be | |
958 | stopped. */ | |
959 | ||
960 | static struct lwp_info * | |
961 | add_lwp (ptid_t ptid) | |
962 | { | |
963 | struct lwp_info *lp; | |
964 | ||
965 | lp = add_initial_lwp (ptid); | |
966 | ||
6e012a6c PA |
967 | /* Let the arch specific bits know about this new thread. Current |
968 | clients of this callback take the opportunity to install | |
26cb8b7c PA |
969 | watchpoints in the new thread. We don't do this for the first |
970 | thread though. See add_initial_lwp. */ | |
971 | if (linux_nat_new_thread != NULL) | |
7b50312a | 972 | linux_nat_new_thread (lp); |
9f0bdab8 | 973 | |
d6b0e80f AC |
974 | return lp; |
975 | } | |
976 | ||
977 | /* Remove the LWP specified by PID from the list. */ | |
978 | ||
979 | static void | |
980 | delete_lwp (ptid_t ptid) | |
981 | { | |
982 | struct lwp_info *lp, *lpprev; | |
983 | ||
984 | lpprev = NULL; | |
985 | ||
986 | for (lp = lwp_list; lp; lpprev = lp, lp = lp->next) | |
987 | if (ptid_equal (lp->ptid, ptid)) | |
988 | break; | |
989 | ||
990 | if (!lp) | |
991 | return; | |
992 | ||
d6b0e80f AC |
993 | if (lpprev) |
994 | lpprev->next = lp->next; | |
995 | else | |
996 | lwp_list = lp->next; | |
997 | ||
7b50312a | 998 | lwp_free (lp); |
d6b0e80f AC |
999 | } |
1000 | ||
1001 | /* Return a pointer to the structure describing the LWP corresponding | |
1002 | to PID. If no corresponding LWP could be found, return NULL. */ | |
1003 | ||
1004 | static struct lwp_info * | |
1005 | find_lwp_pid (ptid_t ptid) | |
1006 | { | |
1007 | struct lwp_info *lp; | |
1008 | int lwp; | |
1009 | ||
1010 | if (is_lwp (ptid)) | |
1011 | lwp = GET_LWP (ptid); | |
1012 | else | |
1013 | lwp = GET_PID (ptid); | |
1014 | ||
1015 | for (lp = lwp_list; lp; lp = lp->next) | |
1016 | if (lwp == GET_LWP (lp->ptid)) | |
1017 | return lp; | |
1018 | ||
1019 | return NULL; | |
1020 | } | |
1021 | ||
1022 | /* Call CALLBACK with its second argument set to DATA for every LWP in | |
1023 | the list. If CALLBACK returns 1 for a particular LWP, return a | |
1024 | pointer to the structure describing that LWP immediately. | |
1025 | Otherwise return NULL. */ | |
1026 | ||
1027 | struct lwp_info * | |
d90e17a7 PA |
1028 | iterate_over_lwps (ptid_t filter, |
1029 | int (*callback) (struct lwp_info *, void *), | |
1030 | void *data) | |
d6b0e80f AC |
1031 | { |
1032 | struct lwp_info *lp, *lpnext; | |
1033 | ||
1034 | for (lp = lwp_list; lp; lp = lpnext) | |
1035 | { | |
1036 | lpnext = lp->next; | |
d90e17a7 PA |
1037 | |
1038 | if (ptid_match (lp->ptid, filter)) | |
1039 | { | |
1040 | if ((*callback) (lp, data)) | |
1041 | return lp; | |
1042 | } | |
d6b0e80f AC |
1043 | } |
1044 | ||
1045 | return NULL; | |
1046 | } | |
1047 | ||
2277426b PA |
1048 | /* Update our internal state when changing from one checkpoint to |
1049 | another indicated by NEW_PTID. We can only switch single-threaded | |
1050 | applications, so we only create one new LWP, and the previous list | |
1051 | is discarded. */ | |
f973ed9c DJ |
1052 | |
1053 | void | |
1054 | linux_nat_switch_fork (ptid_t new_ptid) | |
1055 | { | |
1056 | struct lwp_info *lp; | |
1057 | ||
2277426b PA |
1058 | purge_lwp_list (GET_PID (inferior_ptid)); |
1059 | ||
f973ed9c DJ |
1060 | lp = add_lwp (new_ptid); |
1061 | lp->stopped = 1; | |
e26af52f | 1062 | |
2277426b PA |
1063 | /* This changes the thread's ptid while preserving the gdb thread |
1064 | num. Also changes the inferior pid, while preserving the | |
1065 | inferior num. */ | |
1066 | thread_change_ptid (inferior_ptid, new_ptid); | |
1067 | ||
1068 | /* We've just told GDB core that the thread changed target id, but, | |
1069 | in fact, it really is a different thread, with different register | |
1070 | contents. */ | |
1071 | registers_changed (); | |
e26af52f DJ |
1072 | } |
1073 | ||
e26af52f DJ |
1074 | /* Handle the exit of a single thread LP. */ |
1075 | ||
1076 | static void | |
1077 | exit_lwp (struct lwp_info *lp) | |
1078 | { | |
e09875d4 | 1079 | struct thread_info *th = find_thread_ptid (lp->ptid); |
063bfe2e VP |
1080 | |
1081 | if (th) | |
e26af52f | 1082 | { |
17faa917 DJ |
1083 | if (print_thread_events) |
1084 | printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid)); | |
1085 | ||
4f8d22e3 | 1086 | delete_thread (lp->ptid); |
e26af52f DJ |
1087 | } |
1088 | ||
1089 | delete_lwp (lp->ptid); | |
1090 | } | |
1091 | ||
a0ef4274 DJ |
1092 | /* Wait for the LWP specified by LP, which we have just attached to. |
1093 | Returns a wait status for that LWP, to cache. */ | |
1094 | ||
1095 | static int | |
1096 | linux_nat_post_attach_wait (ptid_t ptid, int first, int *cloned, | |
1097 | int *signalled) | |
1098 | { | |
1099 | pid_t new_pid, pid = GET_LWP (ptid); | |
1100 | int status; | |
1101 | ||
644cebc9 | 1102 | if (linux_proc_pid_is_stopped (pid)) |
a0ef4274 DJ |
1103 | { |
1104 | if (debug_linux_nat) | |
1105 | fprintf_unfiltered (gdb_stdlog, | |
1106 | "LNPAW: Attaching to a stopped process\n"); | |
1107 | ||
1108 | /* The process is definitely stopped. It is in a job control | |
1109 | stop, unless the kernel predates the TASK_STOPPED / | |
1110 | TASK_TRACED distinction, in which case it might be in a | |
1111 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
1112 | can kill it, signal it, et cetera. | |
1113 | ||
1114 | First make sure there is a pending SIGSTOP. Since we are | |
1115 | already attached, the process can not transition from stopped | |
1116 | to running without a PTRACE_CONT; so we know this signal will | |
1117 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
1118 | probably already in the queue (unless this kernel is old | |
1119 | enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP | |
1120 | is not an RT signal, it can only be queued once. */ | |
1121 | kill_lwp (pid, SIGSTOP); | |
1122 | ||
1123 | /* Finally, resume the stopped process. This will deliver the SIGSTOP | |
1124 | (or a higher priority signal, just like normal PTRACE_ATTACH). */ | |
1125 | ptrace (PTRACE_CONT, pid, 0, 0); | |
1126 | } | |
1127 | ||
1128 | /* Make sure the initial process is stopped. The user-level threads | |
1129 | layer might want to poke around in the inferior, and that won't | |
1130 | work if things haven't stabilized yet. */ | |
1131 | new_pid = my_waitpid (pid, &status, 0); | |
1132 | if (new_pid == -1 && errno == ECHILD) | |
1133 | { | |
1134 | if (first) | |
1135 | warning (_("%s is a cloned process"), target_pid_to_str (ptid)); | |
1136 | ||
1137 | /* Try again with __WCLONE to check cloned processes. */ | |
1138 | new_pid = my_waitpid (pid, &status, __WCLONE); | |
1139 | *cloned = 1; | |
1140 | } | |
1141 | ||
dacc9cb2 PP |
1142 | gdb_assert (pid == new_pid); |
1143 | ||
1144 | if (!WIFSTOPPED (status)) | |
1145 | { | |
1146 | /* The pid we tried to attach has apparently just exited. */ | |
1147 | if (debug_linux_nat) | |
1148 | fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s", | |
1149 | pid, status_to_str (status)); | |
1150 | return status; | |
1151 | } | |
a0ef4274 DJ |
1152 | |
1153 | if (WSTOPSIG (status) != SIGSTOP) | |
1154 | { | |
1155 | *signalled = 1; | |
1156 | if (debug_linux_nat) | |
1157 | fprintf_unfiltered (gdb_stdlog, | |
1158 | "LNPAW: Received %s after attaching\n", | |
1159 | status_to_str (status)); | |
1160 | } | |
1161 | ||
1162 | return status; | |
1163 | } | |
1164 | ||
84636d28 PA |
1165 | /* Attach to the LWP specified by PID. Return 0 if successful, -1 if |
1166 | the new LWP could not be attached, or 1 if we're already auto | |
1167 | attached to this thread, but haven't processed the | |
1168 | PTRACE_EVENT_CLONE event of its parent thread, so we just ignore | |
1169 | its existance, without considering it an error. */ | |
d6b0e80f | 1170 | |
9ee57c33 | 1171 | int |
93815fbf | 1172 | lin_lwp_attach_lwp (ptid_t ptid) |
d6b0e80f | 1173 | { |
9ee57c33 | 1174 | struct lwp_info *lp; |
84636d28 | 1175 | int lwpid; |
d6b0e80f AC |
1176 | |
1177 | gdb_assert (is_lwp (ptid)); | |
1178 | ||
9ee57c33 | 1179 | lp = find_lwp_pid (ptid); |
84636d28 | 1180 | lwpid = GET_LWP (ptid); |
d6b0e80f AC |
1181 | |
1182 | /* We assume that we're already attached to any LWP that has an id | |
1183 | equal to the overall process id, and to any LWP that is already | |
1184 | in our list of LWPs. If we're not seeing exit events from threads | |
1185 | and we've had PID wraparound since we last tried to stop all threads, | |
1186 | this assumption might be wrong; fortunately, this is very unlikely | |
1187 | to happen. */ | |
84636d28 | 1188 | if (lwpid != GET_PID (ptid) && lp == NULL) |
d6b0e80f | 1189 | { |
a0ef4274 | 1190 | int status, cloned = 0, signalled = 0; |
d6b0e80f | 1191 | |
84636d28 | 1192 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) |
9ee57c33 | 1193 | { |
96d7229d | 1194 | if (linux_supports_tracefork ()) |
84636d28 PA |
1195 | { |
1196 | /* If we haven't stopped all threads when we get here, | |
1197 | we may have seen a thread listed in thread_db's list, | |
1198 | but not processed the PTRACE_EVENT_CLONE yet. If | |
1199 | that's the case, ignore this new thread, and let | |
1200 | normal event handling discover it later. */ | |
1201 | if (in_pid_list_p (stopped_pids, lwpid)) | |
1202 | { | |
1203 | /* We've already seen this thread stop, but we | |
1204 | haven't seen the PTRACE_EVENT_CLONE extended | |
1205 | event yet. */ | |
84636d28 PA |
1206 | return 0; |
1207 | } | |
1208 | else | |
1209 | { | |
1210 | int new_pid; | |
1211 | int status; | |
1212 | ||
1213 | /* See if we've got a stop for this new child | |
1214 | pending. If so, we're already attached. */ | |
1215 | new_pid = my_waitpid (lwpid, &status, WNOHANG); | |
1216 | if (new_pid == -1 && errno == ECHILD) | |
1217 | new_pid = my_waitpid (lwpid, &status, __WCLONE | WNOHANG); | |
1218 | if (new_pid != -1) | |
1219 | { | |
1220 | if (WIFSTOPPED (status)) | |
1221 | add_to_pid_list (&stopped_pids, lwpid, status); | |
84636d28 PA |
1222 | return 1; |
1223 | } | |
1224 | } | |
1225 | } | |
1226 | ||
9ee57c33 DJ |
1227 | /* If we fail to attach to the thread, issue a warning, |
1228 | but continue. One way this can happen is if thread | |
e9efe249 | 1229 | creation is interrupted; as of Linux kernel 2.6.19, a |
9ee57c33 DJ |
1230 | bug may place threads in the thread list and then fail |
1231 | to create them. */ | |
1232 | warning (_("Can't attach %s: %s"), target_pid_to_str (ptid), | |
1233 | safe_strerror (errno)); | |
1234 | return -1; | |
1235 | } | |
1236 | ||
d6b0e80f AC |
1237 | if (debug_linux_nat) |
1238 | fprintf_unfiltered (gdb_stdlog, | |
1239 | "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n", | |
1240 | target_pid_to_str (ptid)); | |
1241 | ||
a0ef4274 | 1242 | status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled); |
dacc9cb2 | 1243 | if (!WIFSTOPPED (status)) |
12696c10 | 1244 | return 1; |
dacc9cb2 | 1245 | |
a0ef4274 DJ |
1246 | lp = add_lwp (ptid); |
1247 | lp->stopped = 1; | |
1248 | lp->cloned = cloned; | |
1249 | lp->signalled = signalled; | |
1250 | if (WSTOPSIG (status) != SIGSTOP) | |
d6b0e80f | 1251 | { |
a0ef4274 DJ |
1252 | lp->resumed = 1; |
1253 | lp->status = status; | |
d6b0e80f AC |
1254 | } |
1255 | ||
a0ef4274 | 1256 | target_post_attach (GET_LWP (lp->ptid)); |
d6b0e80f AC |
1257 | |
1258 | if (debug_linux_nat) | |
1259 | { | |
1260 | fprintf_unfiltered (gdb_stdlog, | |
1261 | "LLAL: waitpid %s received %s\n", | |
1262 | target_pid_to_str (ptid), | |
1263 | status_to_str (status)); | |
1264 | } | |
1265 | } | |
1266 | else | |
1267 | { | |
1268 | /* We assume that the LWP representing the original process is | |
1269 | already stopped. Mark it as stopped in the data structure | |
155bd5d1 AC |
1270 | that the GNU/linux ptrace layer uses to keep track of |
1271 | threads. Note that this won't have already been done since | |
1272 | the main thread will have, we assume, been stopped by an | |
1273 | attach from a different layer. */ | |
9ee57c33 DJ |
1274 | if (lp == NULL) |
1275 | lp = add_lwp (ptid); | |
d6b0e80f AC |
1276 | lp->stopped = 1; |
1277 | } | |
9ee57c33 | 1278 | |
25289eb2 | 1279 | lp->last_resume_kind = resume_stop; |
9ee57c33 | 1280 | return 0; |
d6b0e80f AC |
1281 | } |
1282 | ||
b84876c2 | 1283 | static void |
136d6dae VP |
1284 | linux_nat_create_inferior (struct target_ops *ops, |
1285 | char *exec_file, char *allargs, char **env, | |
b84876c2 PA |
1286 | int from_tty) |
1287 | { | |
10568435 JK |
1288 | #ifdef HAVE_PERSONALITY |
1289 | int personality_orig = 0, personality_set = 0; | |
1290 | #endif /* HAVE_PERSONALITY */ | |
b84876c2 PA |
1291 | |
1292 | /* The fork_child mechanism is synchronous and calls target_wait, so | |
1293 | we have to mask the async mode. */ | |
1294 | ||
10568435 JK |
1295 | #ifdef HAVE_PERSONALITY |
1296 | if (disable_randomization) | |
1297 | { | |
1298 | errno = 0; | |
1299 | personality_orig = personality (0xffffffff); | |
1300 | if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE)) | |
1301 | { | |
1302 | personality_set = 1; | |
1303 | personality (personality_orig | ADDR_NO_RANDOMIZE); | |
1304 | } | |
1305 | if (errno != 0 || (personality_set | |
1306 | && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE))) | |
1307 | warning (_("Error disabling address space randomization: %s"), | |
1308 | safe_strerror (errno)); | |
1309 | } | |
1310 | #endif /* HAVE_PERSONALITY */ | |
1311 | ||
2455069d UW |
1312 | /* Make sure we report all signals during startup. */ |
1313 | linux_nat_pass_signals (0, NULL); | |
1314 | ||
136d6dae | 1315 | linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty); |
b84876c2 | 1316 | |
10568435 JK |
1317 | #ifdef HAVE_PERSONALITY |
1318 | if (personality_set) | |
1319 | { | |
1320 | errno = 0; | |
1321 | personality (personality_orig); | |
1322 | if (errno != 0) | |
1323 | warning (_("Error restoring address space randomization: %s"), | |
1324 | safe_strerror (errno)); | |
1325 | } | |
1326 | #endif /* HAVE_PERSONALITY */ | |
b84876c2 PA |
1327 | } |
1328 | ||
d6b0e80f | 1329 | static void |
136d6dae | 1330 | linux_nat_attach (struct target_ops *ops, char *args, int from_tty) |
d6b0e80f AC |
1331 | { |
1332 | struct lwp_info *lp; | |
d6b0e80f | 1333 | int status; |
af990527 | 1334 | ptid_t ptid; |
87b0bb13 | 1335 | volatile struct gdb_exception ex; |
d6b0e80f | 1336 | |
2455069d UW |
1337 | /* Make sure we report all signals during attach. */ |
1338 | linux_nat_pass_signals (0, NULL); | |
1339 | ||
87b0bb13 JK |
1340 | TRY_CATCH (ex, RETURN_MASK_ERROR) |
1341 | { | |
1342 | linux_ops->to_attach (ops, args, from_tty); | |
1343 | } | |
1344 | if (ex.reason < 0) | |
1345 | { | |
1346 | pid_t pid = parse_pid_to_attach (args); | |
1347 | struct buffer buffer; | |
1348 | char *message, *buffer_s; | |
1349 | ||
1350 | message = xstrdup (ex.message); | |
1351 | make_cleanup (xfree, message); | |
1352 | ||
1353 | buffer_init (&buffer); | |
1354 | linux_ptrace_attach_warnings (pid, &buffer); | |
1355 | ||
1356 | buffer_grow_str0 (&buffer, ""); | |
1357 | buffer_s = buffer_finish (&buffer); | |
1358 | make_cleanup (xfree, buffer_s); | |
1359 | ||
1360 | throw_error (ex.error, "%s%s", buffer_s, message); | |
1361 | } | |
d6b0e80f | 1362 | |
af990527 PA |
1363 | /* The ptrace base target adds the main thread with (pid,0,0) |
1364 | format. Decorate it with lwp info. */ | |
1365 | ptid = BUILD_LWP (GET_PID (inferior_ptid), GET_PID (inferior_ptid)); | |
1366 | thread_change_ptid (inferior_ptid, ptid); | |
1367 | ||
9f0bdab8 | 1368 | /* Add the initial process as the first LWP to the list. */ |
26cb8b7c | 1369 | lp = add_initial_lwp (ptid); |
a0ef4274 DJ |
1370 | |
1371 | status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->cloned, | |
1372 | &lp->signalled); | |
dacc9cb2 PP |
1373 | if (!WIFSTOPPED (status)) |
1374 | { | |
1375 | if (WIFEXITED (status)) | |
1376 | { | |
1377 | int exit_code = WEXITSTATUS (status); | |
1378 | ||
1379 | target_terminal_ours (); | |
1380 | target_mourn_inferior (); | |
1381 | if (exit_code == 0) | |
1382 | error (_("Unable to attach: program exited normally.")); | |
1383 | else | |
1384 | error (_("Unable to attach: program exited with code %d."), | |
1385 | exit_code); | |
1386 | } | |
1387 | else if (WIFSIGNALED (status)) | |
1388 | { | |
2ea28649 | 1389 | enum gdb_signal signo; |
dacc9cb2 PP |
1390 | |
1391 | target_terminal_ours (); | |
1392 | target_mourn_inferior (); | |
1393 | ||
2ea28649 | 1394 | signo = gdb_signal_from_host (WTERMSIG (status)); |
dacc9cb2 PP |
1395 | error (_("Unable to attach: program terminated with signal " |
1396 | "%s, %s."), | |
2ea28649 PA |
1397 | gdb_signal_to_name (signo), |
1398 | gdb_signal_to_string (signo)); | |
dacc9cb2 PP |
1399 | } |
1400 | ||
1401 | internal_error (__FILE__, __LINE__, | |
1402 | _("unexpected status %d for PID %ld"), | |
1403 | status, (long) GET_LWP (ptid)); | |
1404 | } | |
1405 | ||
a0ef4274 | 1406 | lp->stopped = 1; |
9f0bdab8 | 1407 | |
a0ef4274 | 1408 | /* Save the wait status to report later. */ |
d6b0e80f | 1409 | lp->resumed = 1; |
a0ef4274 DJ |
1410 | if (debug_linux_nat) |
1411 | fprintf_unfiltered (gdb_stdlog, | |
1412 | "LNA: waitpid %ld, saving status %s\n", | |
1413 | (long) GET_PID (lp->ptid), status_to_str (status)); | |
710151dd | 1414 | |
7feb7d06 PA |
1415 | lp->status = status; |
1416 | ||
1417 | if (target_can_async_p ()) | |
1418 | target_async (inferior_event_handler, 0); | |
d6b0e80f AC |
1419 | } |
1420 | ||
a0ef4274 DJ |
1421 | /* Get pending status of LP. */ |
1422 | static int | |
1423 | get_pending_status (struct lwp_info *lp, int *status) | |
1424 | { | |
a493e3e2 | 1425 | enum gdb_signal signo = GDB_SIGNAL_0; |
ca2163eb PA |
1426 | |
1427 | /* If we paused threads momentarily, we may have stored pending | |
1428 | events in lp->status or lp->waitstatus (see stop_wait_callback), | |
1429 | and GDB core hasn't seen any signal for those threads. | |
1430 | Otherwise, the last signal reported to the core is found in the | |
1431 | thread object's stop_signal. | |
1432 | ||
1433 | There's a corner case that isn't handled here at present. Only | |
1434 | if the thread stopped with a TARGET_WAITKIND_STOPPED does | |
1435 | stop_signal make sense as a real signal to pass to the inferior. | |
1436 | Some catchpoint related events, like | |
1437 | TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set | |
a493e3e2 | 1438 | to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But, |
ca2163eb PA |
1439 | those traps are debug API (ptrace in our case) related and |
1440 | induced; the inferior wouldn't see them if it wasn't being | |
1441 | traced. Hence, we should never pass them to the inferior, even | |
1442 | when set to pass state. Since this corner case isn't handled by | |
1443 | infrun.c when proceeding with a signal, for consistency, neither | |
1444 | do we handle it here (or elsewhere in the file we check for | |
1445 | signal pass state). Normally SIGTRAP isn't set to pass state, so | |
1446 | this is really a corner case. */ | |
1447 | ||
1448 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
a493e3e2 | 1449 | signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */ |
ca2163eb | 1450 | else if (lp->status) |
2ea28649 | 1451 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
ca2163eb PA |
1452 | else if (non_stop && !is_executing (lp->ptid)) |
1453 | { | |
1454 | struct thread_info *tp = find_thread_ptid (lp->ptid); | |
e0881a8e | 1455 | |
16c381f0 | 1456 | signo = tp->suspend.stop_signal; |
ca2163eb PA |
1457 | } |
1458 | else if (!non_stop) | |
a0ef4274 | 1459 | { |
ca2163eb PA |
1460 | struct target_waitstatus last; |
1461 | ptid_t last_ptid; | |
4c28f408 | 1462 | |
ca2163eb | 1463 | get_last_target_status (&last_ptid, &last); |
4c28f408 | 1464 | |
ca2163eb PA |
1465 | if (GET_LWP (lp->ptid) == GET_LWP (last_ptid)) |
1466 | { | |
e09875d4 | 1467 | struct thread_info *tp = find_thread_ptid (lp->ptid); |
e0881a8e | 1468 | |
16c381f0 | 1469 | signo = tp->suspend.stop_signal; |
4c28f408 | 1470 | } |
ca2163eb | 1471 | } |
4c28f408 | 1472 | |
ca2163eb | 1473 | *status = 0; |
4c28f408 | 1474 | |
a493e3e2 | 1475 | if (signo == GDB_SIGNAL_0) |
ca2163eb PA |
1476 | { |
1477 | if (debug_linux_nat) | |
1478 | fprintf_unfiltered (gdb_stdlog, | |
1479 | "GPT: lwp %s has no pending signal\n", | |
1480 | target_pid_to_str (lp->ptid)); | |
1481 | } | |
1482 | else if (!signal_pass_state (signo)) | |
1483 | { | |
1484 | if (debug_linux_nat) | |
3e43a32a MS |
1485 | fprintf_unfiltered (gdb_stdlog, |
1486 | "GPT: lwp %s had signal %s, " | |
1487 | "but it is in no pass state\n", | |
ca2163eb | 1488 | target_pid_to_str (lp->ptid), |
2ea28649 | 1489 | gdb_signal_to_string (signo)); |
a0ef4274 | 1490 | } |
a0ef4274 | 1491 | else |
4c28f408 | 1492 | { |
2ea28649 | 1493 | *status = W_STOPCODE (gdb_signal_to_host (signo)); |
ca2163eb PA |
1494 | |
1495 | if (debug_linux_nat) | |
1496 | fprintf_unfiltered (gdb_stdlog, | |
1497 | "GPT: lwp %s has pending signal %s\n", | |
1498 | target_pid_to_str (lp->ptid), | |
2ea28649 | 1499 | gdb_signal_to_string (signo)); |
4c28f408 | 1500 | } |
a0ef4274 DJ |
1501 | |
1502 | return 0; | |
1503 | } | |
1504 | ||
d6b0e80f AC |
1505 | static int |
1506 | detach_callback (struct lwp_info *lp, void *data) | |
1507 | { | |
1508 | gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status)); | |
1509 | ||
1510 | if (debug_linux_nat && lp->status) | |
1511 | fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n", | |
1512 | strsignal (WSTOPSIG (lp->status)), | |
1513 | target_pid_to_str (lp->ptid)); | |
1514 | ||
a0ef4274 DJ |
1515 | /* If there is a pending SIGSTOP, get rid of it. */ |
1516 | if (lp->signalled) | |
d6b0e80f | 1517 | { |
d6b0e80f AC |
1518 | if (debug_linux_nat) |
1519 | fprintf_unfiltered (gdb_stdlog, | |
a0ef4274 DJ |
1520 | "DC: Sending SIGCONT to %s\n", |
1521 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 1522 | |
a0ef4274 | 1523 | kill_lwp (GET_LWP (lp->ptid), SIGCONT); |
d6b0e80f | 1524 | lp->signalled = 0; |
d6b0e80f AC |
1525 | } |
1526 | ||
1527 | /* We don't actually detach from the LWP that has an id equal to the | |
1528 | overall process id just yet. */ | |
1529 | if (GET_LWP (lp->ptid) != GET_PID (lp->ptid)) | |
1530 | { | |
a0ef4274 DJ |
1531 | int status = 0; |
1532 | ||
1533 | /* Pass on any pending signal for this LWP. */ | |
1534 | get_pending_status (lp, &status); | |
1535 | ||
7b50312a PA |
1536 | if (linux_nat_prepare_to_resume != NULL) |
1537 | linux_nat_prepare_to_resume (lp); | |
d6b0e80f AC |
1538 | errno = 0; |
1539 | if (ptrace (PTRACE_DETACH, GET_LWP (lp->ptid), 0, | |
a0ef4274 | 1540 | WSTOPSIG (status)) < 0) |
8a3fe4f8 | 1541 | error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid), |
d6b0e80f AC |
1542 | safe_strerror (errno)); |
1543 | ||
1544 | if (debug_linux_nat) | |
1545 | fprintf_unfiltered (gdb_stdlog, | |
1546 | "PTRACE_DETACH (%s, %s, 0) (OK)\n", | |
1547 | target_pid_to_str (lp->ptid), | |
7feb7d06 | 1548 | strsignal (WSTOPSIG (status))); |
d6b0e80f AC |
1549 | |
1550 | delete_lwp (lp->ptid); | |
1551 | } | |
1552 | ||
1553 | return 0; | |
1554 | } | |
1555 | ||
1556 | static void | |
136d6dae | 1557 | linux_nat_detach (struct target_ops *ops, char *args, int from_tty) |
d6b0e80f | 1558 | { |
b84876c2 | 1559 | int pid; |
a0ef4274 | 1560 | int status; |
d90e17a7 PA |
1561 | struct lwp_info *main_lwp; |
1562 | ||
1563 | pid = GET_PID (inferior_ptid); | |
a0ef4274 | 1564 | |
ae5e0686 MK |
1565 | /* Don't unregister from the event loop, as there may be other |
1566 | inferiors running. */ | |
b84876c2 | 1567 | |
4c28f408 PA |
1568 | /* Stop all threads before detaching. ptrace requires that the |
1569 | thread is stopped to sucessfully detach. */ | |
d90e17a7 | 1570 | iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL); |
4c28f408 PA |
1571 | /* ... and wait until all of them have reported back that |
1572 | they're no longer running. */ | |
d90e17a7 | 1573 | iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL); |
4c28f408 | 1574 | |
d90e17a7 | 1575 | iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL); |
d6b0e80f AC |
1576 | |
1577 | /* Only the initial process should be left right now. */ | |
d90e17a7 PA |
1578 | gdb_assert (num_lwps (GET_PID (inferior_ptid)) == 1); |
1579 | ||
1580 | main_lwp = find_lwp_pid (pid_to_ptid (pid)); | |
d6b0e80f | 1581 | |
a0ef4274 DJ |
1582 | /* Pass on any pending signal for the last LWP. */ |
1583 | if ((args == NULL || *args == '\0') | |
d90e17a7 | 1584 | && get_pending_status (main_lwp, &status) != -1 |
a0ef4274 DJ |
1585 | && WIFSTOPPED (status)) |
1586 | { | |
1587 | /* Put the signal number in ARGS so that inf_ptrace_detach will | |
1588 | pass it along with PTRACE_DETACH. */ | |
1589 | args = alloca (8); | |
1590 | sprintf (args, "%d", (int) WSTOPSIG (status)); | |
ddabfc73 TT |
1591 | if (debug_linux_nat) |
1592 | fprintf_unfiltered (gdb_stdlog, | |
1593 | "LND: Sending signal %s to %s\n", | |
1594 | args, | |
1595 | target_pid_to_str (main_lwp->ptid)); | |
a0ef4274 DJ |
1596 | } |
1597 | ||
7b50312a PA |
1598 | if (linux_nat_prepare_to_resume != NULL) |
1599 | linux_nat_prepare_to_resume (main_lwp); | |
d90e17a7 | 1600 | delete_lwp (main_lwp->ptid); |
b84876c2 | 1601 | |
7a7d3353 PA |
1602 | if (forks_exist_p ()) |
1603 | { | |
1604 | /* Multi-fork case. The current inferior_ptid is being detached | |
1605 | from, but there are other viable forks to debug. Detach from | |
1606 | the current fork, and context-switch to the first | |
1607 | available. */ | |
1608 | linux_fork_detach (args, from_tty); | |
7a7d3353 PA |
1609 | } |
1610 | else | |
1611 | linux_ops->to_detach (ops, args, from_tty); | |
d6b0e80f AC |
1612 | } |
1613 | ||
1614 | /* Resume LP. */ | |
1615 | ||
25289eb2 | 1616 | static void |
e5ef252a | 1617 | resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) |
d6b0e80f | 1618 | { |
25289eb2 | 1619 | if (lp->stopped) |
6c95b8df | 1620 | { |
25289eb2 PA |
1621 | struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid)); |
1622 | ||
1623 | if (inf->vfork_child != NULL) | |
1624 | { | |
1625 | if (debug_linux_nat) | |
1626 | fprintf_unfiltered (gdb_stdlog, | |
1627 | "RC: Not resuming %s (vfork parent)\n", | |
1628 | target_pid_to_str (lp->ptid)); | |
1629 | } | |
1630 | else if (lp->status == 0 | |
1631 | && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) | |
1632 | { | |
1633 | if (debug_linux_nat) | |
1634 | fprintf_unfiltered (gdb_stdlog, | |
e5ef252a PA |
1635 | "RC: Resuming sibling %s, %s, %s\n", |
1636 | target_pid_to_str (lp->ptid), | |
1637 | (signo != GDB_SIGNAL_0 | |
1638 | ? strsignal (gdb_signal_to_host (signo)) | |
1639 | : "0"), | |
1640 | step ? "step" : "resume"); | |
25289eb2 | 1641 | |
7b50312a PA |
1642 | if (linux_nat_prepare_to_resume != NULL) |
1643 | linux_nat_prepare_to_resume (lp); | |
25289eb2 PA |
1644 | linux_ops->to_resume (linux_ops, |
1645 | pid_to_ptid (GET_LWP (lp->ptid)), | |
e5ef252a | 1646 | step, signo); |
25289eb2 PA |
1647 | lp->stopped = 0; |
1648 | lp->step = step; | |
25289eb2 PA |
1649 | lp->stopped_by_watchpoint = 0; |
1650 | } | |
1651 | else | |
1652 | { | |
1653 | if (debug_linux_nat) | |
1654 | fprintf_unfiltered (gdb_stdlog, | |
1655 | "RC: Not resuming sibling %s (has pending)\n", | |
1656 | target_pid_to_str (lp->ptid)); | |
1657 | } | |
6c95b8df | 1658 | } |
25289eb2 | 1659 | else |
d6b0e80f | 1660 | { |
d90e17a7 PA |
1661 | if (debug_linux_nat) |
1662 | fprintf_unfiltered (gdb_stdlog, | |
25289eb2 | 1663 | "RC: Not resuming sibling %s (not stopped)\n", |
d6b0e80f | 1664 | target_pid_to_str (lp->ptid)); |
d6b0e80f | 1665 | } |
25289eb2 | 1666 | } |
d6b0e80f | 1667 | |
e5ef252a PA |
1668 | /* Resume LWP, with the last stop signal, if it is in pass state. */ |
1669 | ||
25289eb2 | 1670 | static int |
e5ef252a | 1671 | linux_nat_resume_callback (struct lwp_info *lp, void *data) |
25289eb2 | 1672 | { |
e5ef252a PA |
1673 | enum gdb_signal signo = GDB_SIGNAL_0; |
1674 | ||
1675 | if (lp->stopped) | |
1676 | { | |
1677 | struct thread_info *thread; | |
1678 | ||
1679 | thread = find_thread_ptid (lp->ptid); | |
1680 | if (thread != NULL) | |
1681 | { | |
1682 | if (signal_pass_state (thread->suspend.stop_signal)) | |
1683 | signo = thread->suspend.stop_signal; | |
1684 | thread->suspend.stop_signal = GDB_SIGNAL_0; | |
1685 | } | |
1686 | } | |
1687 | ||
1688 | resume_lwp (lp, 0, signo); | |
d6b0e80f AC |
1689 | return 0; |
1690 | } | |
1691 | ||
1692 | static int | |
1693 | resume_clear_callback (struct lwp_info *lp, void *data) | |
1694 | { | |
1695 | lp->resumed = 0; | |
25289eb2 | 1696 | lp->last_resume_kind = resume_stop; |
d6b0e80f AC |
1697 | return 0; |
1698 | } | |
1699 | ||
1700 | static int | |
1701 | resume_set_callback (struct lwp_info *lp, void *data) | |
1702 | { | |
1703 | lp->resumed = 1; | |
25289eb2 | 1704 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1705 | return 0; |
1706 | } | |
1707 | ||
1708 | static void | |
28439f5e | 1709 | linux_nat_resume (struct target_ops *ops, |
2ea28649 | 1710 | ptid_t ptid, int step, enum gdb_signal signo) |
d6b0e80f AC |
1711 | { |
1712 | struct lwp_info *lp; | |
d90e17a7 | 1713 | int resume_many; |
d6b0e80f | 1714 | |
76f50ad1 DJ |
1715 | if (debug_linux_nat) |
1716 | fprintf_unfiltered (gdb_stdlog, | |
1717 | "LLR: Preparing to %s %s, %s, inferior_ptid %s\n", | |
1718 | step ? "step" : "resume", | |
1719 | target_pid_to_str (ptid), | |
a493e3e2 | 1720 | (signo != GDB_SIGNAL_0 |
2ea28649 | 1721 | ? strsignal (gdb_signal_to_host (signo)) : "0"), |
76f50ad1 DJ |
1722 | target_pid_to_str (inferior_ptid)); |
1723 | ||
d6b0e80f | 1724 | /* A specific PTID means `step only this process id'. */ |
d90e17a7 PA |
1725 | resume_many = (ptid_equal (minus_one_ptid, ptid) |
1726 | || ptid_is_pid (ptid)); | |
4c28f408 | 1727 | |
e3e9f5a2 PA |
1728 | /* Mark the lwps we're resuming as resumed. */ |
1729 | iterate_over_lwps (ptid, resume_set_callback, NULL); | |
d6b0e80f | 1730 | |
d90e17a7 PA |
1731 | /* See if it's the current inferior that should be handled |
1732 | specially. */ | |
1733 | if (resume_many) | |
1734 | lp = find_lwp_pid (inferior_ptid); | |
1735 | else | |
1736 | lp = find_lwp_pid (ptid); | |
9f0bdab8 | 1737 | gdb_assert (lp != NULL); |
d6b0e80f | 1738 | |
9f0bdab8 DJ |
1739 | /* Remember if we're stepping. */ |
1740 | lp->step = step; | |
25289eb2 | 1741 | lp->last_resume_kind = step ? resume_step : resume_continue; |
d6b0e80f | 1742 | |
9f0bdab8 DJ |
1743 | /* If we have a pending wait status for this thread, there is no |
1744 | point in resuming the process. But first make sure that | |
1745 | linux_nat_wait won't preemptively handle the event - we | |
1746 | should never take this short-circuit if we are going to | |
1747 | leave LP running, since we have skipped resuming all the | |
1748 | other threads. This bit of code needs to be synchronized | |
1749 | with linux_nat_wait. */ | |
76f50ad1 | 1750 | |
9f0bdab8 DJ |
1751 | if (lp->status && WIFSTOPPED (lp->status)) |
1752 | { | |
2455069d UW |
1753 | if (!lp->step |
1754 | && WSTOPSIG (lp->status) | |
1755 | && sigismember (&pass_mask, WSTOPSIG (lp->status))) | |
d6b0e80f | 1756 | { |
9f0bdab8 DJ |
1757 | if (debug_linux_nat) |
1758 | fprintf_unfiltered (gdb_stdlog, | |
1759 | "LLR: Not short circuiting for ignored " | |
1760 | "status 0x%x\n", lp->status); | |
1761 | ||
d6b0e80f AC |
1762 | /* FIXME: What should we do if we are supposed to continue |
1763 | this thread with a signal? */ | |
a493e3e2 | 1764 | gdb_assert (signo == GDB_SIGNAL_0); |
2ea28649 | 1765 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
9f0bdab8 DJ |
1766 | lp->status = 0; |
1767 | } | |
1768 | } | |
76f50ad1 | 1769 | |
6c95b8df | 1770 | if (lp->status || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) |
9f0bdab8 DJ |
1771 | { |
1772 | /* FIXME: What should we do if we are supposed to continue | |
1773 | this thread with a signal? */ | |
a493e3e2 | 1774 | gdb_assert (signo == GDB_SIGNAL_0); |
76f50ad1 | 1775 | |
9f0bdab8 DJ |
1776 | if (debug_linux_nat) |
1777 | fprintf_unfiltered (gdb_stdlog, | |
1778 | "LLR: Short circuiting for status 0x%x\n", | |
1779 | lp->status); | |
d6b0e80f | 1780 | |
7feb7d06 PA |
1781 | if (target_can_async_p ()) |
1782 | { | |
1783 | target_async (inferior_event_handler, 0); | |
1784 | /* Tell the event loop we have something to process. */ | |
1785 | async_file_mark (); | |
1786 | } | |
9f0bdab8 | 1787 | return; |
d6b0e80f AC |
1788 | } |
1789 | ||
9f0bdab8 | 1790 | /* Mark LWP as not stopped to prevent it from being continued by |
e5ef252a | 1791 | linux_nat_resume_callback. */ |
9f0bdab8 DJ |
1792 | lp->stopped = 0; |
1793 | ||
d90e17a7 | 1794 | if (resume_many) |
e5ef252a | 1795 | iterate_over_lwps (ptid, linux_nat_resume_callback, NULL); |
d90e17a7 PA |
1796 | |
1797 | /* Convert to something the lower layer understands. */ | |
1798 | ptid = pid_to_ptid (GET_LWP (lp->ptid)); | |
d6b0e80f | 1799 | |
7b50312a PA |
1800 | if (linux_nat_prepare_to_resume != NULL) |
1801 | linux_nat_prepare_to_resume (lp); | |
28439f5e | 1802 | linux_ops->to_resume (linux_ops, ptid, step, signo); |
ebec9a0f | 1803 | lp->stopped_by_watchpoint = 0; |
9f0bdab8 | 1804 | |
d6b0e80f AC |
1805 | if (debug_linux_nat) |
1806 | fprintf_unfiltered (gdb_stdlog, | |
1807 | "LLR: %s %s, %s (resume event thread)\n", | |
1808 | step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
1809 | target_pid_to_str (ptid), | |
a493e3e2 | 1810 | (signo != GDB_SIGNAL_0 |
2ea28649 | 1811 | ? strsignal (gdb_signal_to_host (signo)) : "0")); |
b84876c2 PA |
1812 | |
1813 | if (target_can_async_p ()) | |
8ea051c5 | 1814 | target_async (inferior_event_handler, 0); |
d6b0e80f AC |
1815 | } |
1816 | ||
c5f62d5f | 1817 | /* Send a signal to an LWP. */ |
d6b0e80f AC |
1818 | |
1819 | static int | |
1820 | kill_lwp (int lwpid, int signo) | |
1821 | { | |
c5f62d5f DE |
1822 | /* Use tkill, if possible, in case we are using nptl threads. If tkill |
1823 | fails, then we are not using nptl threads and we should be using kill. */ | |
d6b0e80f AC |
1824 | |
1825 | #ifdef HAVE_TKILL_SYSCALL | |
c5f62d5f DE |
1826 | { |
1827 | static int tkill_failed; | |
1828 | ||
1829 | if (!tkill_failed) | |
1830 | { | |
1831 | int ret; | |
1832 | ||
1833 | errno = 0; | |
1834 | ret = syscall (__NR_tkill, lwpid, signo); | |
1835 | if (errno != ENOSYS) | |
1836 | return ret; | |
1837 | tkill_failed = 1; | |
1838 | } | |
1839 | } | |
d6b0e80f AC |
1840 | #endif |
1841 | ||
1842 | return kill (lwpid, signo); | |
1843 | } | |
1844 | ||
ca2163eb PA |
1845 | /* Handle a GNU/Linux syscall trap wait response. If we see a syscall |
1846 | event, check if the core is interested in it: if not, ignore the | |
1847 | event, and keep waiting; otherwise, we need to toggle the LWP's | |
1848 | syscall entry/exit status, since the ptrace event itself doesn't | |
1849 | indicate it, and report the trap to higher layers. */ | |
1850 | ||
1851 | static int | |
1852 | linux_handle_syscall_trap (struct lwp_info *lp, int stopping) | |
1853 | { | |
1854 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
1855 | struct gdbarch *gdbarch = target_thread_architecture (lp->ptid); | |
1856 | int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid); | |
1857 | ||
1858 | if (stopping) | |
1859 | { | |
1860 | /* If we're stopping threads, there's a SIGSTOP pending, which | |
1861 | makes it so that the LWP reports an immediate syscall return, | |
1862 | followed by the SIGSTOP. Skip seeing that "return" using | |
1863 | PTRACE_CONT directly, and let stop_wait_callback collect the | |
1864 | SIGSTOP. Later when the thread is resumed, a new syscall | |
1865 | entry event. If we didn't do this (and returned 0), we'd | |
1866 | leave a syscall entry pending, and our caller, by using | |
1867 | PTRACE_CONT to collect the SIGSTOP, skips the syscall return | |
1868 | itself. Later, when the user re-resumes this LWP, we'd see | |
1869 | another syscall entry event and we'd mistake it for a return. | |
1870 | ||
1871 | If stop_wait_callback didn't force the SIGSTOP out of the LWP | |
1872 | (leaving immediately with LWP->signalled set, without issuing | |
1873 | a PTRACE_CONT), it would still be problematic to leave this | |
1874 | syscall enter pending, as later when the thread is resumed, | |
1875 | it would then see the same syscall exit mentioned above, | |
1876 | followed by the delayed SIGSTOP, while the syscall didn't | |
1877 | actually get to execute. It seems it would be even more | |
1878 | confusing to the user. */ | |
1879 | ||
1880 | if (debug_linux_nat) | |
1881 | fprintf_unfiltered (gdb_stdlog, | |
1882 | "LHST: ignoring syscall %d " | |
1883 | "for LWP %ld (stopping threads), " | |
1884 | "resuming with PTRACE_CONT for SIGSTOP\n", | |
1885 | syscall_number, | |
1886 | GET_LWP (lp->ptid)); | |
1887 | ||
1888 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
1889 | ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); | |
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, | |
1918 | GET_LWP (lp->ptid)); | |
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, | |
1929 | GET_LWP (lp->ptid)); | |
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, | |
1955 | GET_LWP (lp->ptid)); | |
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 | ||
1966 | /* Note that gdbarch_get_syscall_number may access registers, hence | |
1967 | fill a regcache. */ | |
1968 | registers_changed (); | |
7b50312a PA |
1969 | if (linux_nat_prepare_to_resume != NULL) |
1970 | linux_nat_prepare_to_resume (lp); | |
ca2163eb | 1971 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
a493e3e2 | 1972 | lp->step, GDB_SIGNAL_0); |
ca2163eb PA |
1973 | return 1; |
1974 | } | |
1975 | ||
3d799a95 DJ |
1976 | /* Handle a GNU/Linux extended wait response. If we see a clone |
1977 | event, we need to add the new LWP to our list (and not report the | |
1978 | trap to higher layers). This function returns non-zero if the | |
1979 | event should be ignored and we should wait again. If STOPPING is | |
1980 | true, the new LWP remains stopped, otherwise it is continued. */ | |
d6b0e80f AC |
1981 | |
1982 | static int | |
3d799a95 DJ |
1983 | linux_handle_extended_wait (struct lwp_info *lp, int status, |
1984 | int stopping) | |
d6b0e80f | 1985 | { |
3d799a95 DJ |
1986 | int pid = GET_LWP (lp->ptid); |
1987 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
3d799a95 | 1988 | int event = status >> 16; |
d6b0e80f | 1989 | |
3d799a95 DJ |
1990 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
1991 | || event == PTRACE_EVENT_CLONE) | |
d6b0e80f | 1992 | { |
3d799a95 DJ |
1993 | unsigned long new_pid; |
1994 | int ret; | |
1995 | ||
1996 | ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); | |
6fc19103 | 1997 | |
3d799a95 DJ |
1998 | /* If we haven't already seen the new PID stop, wait for it now. */ |
1999 | if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
2000 | { | |
2001 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
2002 | hits the SIGSTOP, but we're already attached. */ | |
2003 | ret = my_waitpid (new_pid, &status, | |
2004 | (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0); | |
2005 | if (ret == -1) | |
2006 | perror_with_name (_("waiting for new child")); | |
2007 | else if (ret != new_pid) | |
2008 | internal_error (__FILE__, __LINE__, | |
2009 | _("wait returned unexpected PID %d"), ret); | |
2010 | else if (!WIFSTOPPED (status)) | |
2011 | internal_error (__FILE__, __LINE__, | |
2012 | _("wait returned unexpected status 0x%x"), status); | |
2013 | } | |
2014 | ||
3a3e9ee3 | 2015 | ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0); |
3d799a95 | 2016 | |
26cb8b7c PA |
2017 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) |
2018 | { | |
2019 | /* The arch-specific native code may need to know about new | |
2020 | forks even if those end up never mapped to an | |
2021 | inferior. */ | |
2022 | if (linux_nat_new_fork != NULL) | |
2023 | linux_nat_new_fork (lp, new_pid); | |
2024 | } | |
2025 | ||
2277426b PA |
2026 | if (event == PTRACE_EVENT_FORK |
2027 | && linux_fork_checkpointing_p (GET_PID (lp->ptid))) | |
2028 | { | |
2277426b PA |
2029 | /* Handle checkpointing by linux-fork.c here as a special |
2030 | case. We don't want the follow-fork-mode or 'catch fork' | |
2031 | to interfere with this. */ | |
2032 | ||
2033 | /* This won't actually modify the breakpoint list, but will | |
2034 | physically remove the breakpoints from the child. */ | |
d80ee84f | 2035 | detach_breakpoints (ptid_build (new_pid, new_pid, 0)); |
2277426b PA |
2036 | |
2037 | /* Retain child fork in ptrace (stopped) state. */ | |
14571dad MS |
2038 | if (!find_fork_pid (new_pid)) |
2039 | add_fork (new_pid); | |
2277426b PA |
2040 | |
2041 | /* Report as spurious, so that infrun doesn't want to follow | |
2042 | this fork. We're actually doing an infcall in | |
2043 | linux-fork.c. */ | |
2044 | ourstatus->kind = TARGET_WAITKIND_SPURIOUS; | |
2277426b PA |
2045 | |
2046 | /* Report the stop to the core. */ | |
2047 | return 0; | |
2048 | } | |
2049 | ||
3d799a95 DJ |
2050 | if (event == PTRACE_EVENT_FORK) |
2051 | ourstatus->kind = TARGET_WAITKIND_FORKED; | |
2052 | else if (event == PTRACE_EVENT_VFORK) | |
2053 | ourstatus->kind = TARGET_WAITKIND_VFORKED; | |
6fc19103 | 2054 | else |
3d799a95 | 2055 | { |
78768c4a JK |
2056 | struct lwp_info *new_lp; |
2057 | ||
3d799a95 | 2058 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
78768c4a | 2059 | |
3c4d7e12 PA |
2060 | if (debug_linux_nat) |
2061 | fprintf_unfiltered (gdb_stdlog, | |
2062 | "LHEW: Got clone event " | |
2063 | "from LWP %d, new child is LWP %ld\n", | |
2064 | pid, new_pid); | |
2065 | ||
d90e17a7 | 2066 | new_lp = add_lwp (BUILD_LWP (new_pid, GET_PID (lp->ptid))); |
3d799a95 | 2067 | new_lp->cloned = 1; |
4c28f408 | 2068 | new_lp->stopped = 1; |
d6b0e80f | 2069 | |
3d799a95 DJ |
2070 | if (WSTOPSIG (status) != SIGSTOP) |
2071 | { | |
2072 | /* This can happen if someone starts sending signals to | |
2073 | the new thread before it gets a chance to run, which | |
2074 | have a lower number than SIGSTOP (e.g. SIGUSR1). | |
2075 | This is an unlikely case, and harder to handle for | |
2076 | fork / vfork than for clone, so we do not try - but | |
2077 | we handle it for clone events here. We'll send | |
2078 | the other signal on to the thread below. */ | |
2079 | ||
2080 | new_lp->signalled = 1; | |
2081 | } | |
2082 | else | |
79395f92 PA |
2083 | { |
2084 | struct thread_info *tp; | |
2085 | ||
2086 | /* When we stop for an event in some other thread, and | |
2087 | pull the thread list just as this thread has cloned, | |
2088 | we'll have seen the new thread in the thread_db list | |
2089 | before handling the CLONE event (glibc's | |
2090 | pthread_create adds the new thread to the thread list | |
2091 | before clone'ing, and has the kernel fill in the | |
2092 | thread's tid on the clone call with | |
2093 | CLONE_PARENT_SETTID). If that happened, and the core | |
2094 | had requested the new thread to stop, we'll have | |
2095 | killed it with SIGSTOP. But since SIGSTOP is not an | |
2096 | RT signal, it can only be queued once. We need to be | |
2097 | careful to not resume the LWP if we wanted it to | |
2098 | stop. In that case, we'll leave the SIGSTOP pending. | |
a493e3e2 | 2099 | It will later be reported as GDB_SIGNAL_0. */ |
79395f92 PA |
2100 | tp = find_thread_ptid (new_lp->ptid); |
2101 | if (tp != NULL && tp->stop_requested) | |
2102 | new_lp->last_resume_kind = resume_stop; | |
2103 | else | |
2104 | status = 0; | |
2105 | } | |
d6b0e80f | 2106 | |
4c28f408 | 2107 | if (non_stop) |
3d799a95 | 2108 | { |
4c28f408 PA |
2109 | /* Add the new thread to GDB's lists as soon as possible |
2110 | so that: | |
2111 | ||
2112 | 1) the frontend doesn't have to wait for a stop to | |
2113 | display them, and, | |
2114 | ||
2115 | 2) we tag it with the correct running state. */ | |
2116 | ||
2117 | /* If the thread_db layer is active, let it know about | |
2118 | this new thread, and add it to GDB's list. */ | |
2119 | if (!thread_db_attach_lwp (new_lp->ptid)) | |
2120 | { | |
2121 | /* We're not using thread_db. Add it to GDB's | |
2122 | list. */ | |
2123 | target_post_attach (GET_LWP (new_lp->ptid)); | |
2124 | add_thread (new_lp->ptid); | |
2125 | } | |
2126 | ||
2127 | if (!stopping) | |
2128 | { | |
2129 | set_running (new_lp->ptid, 1); | |
2130 | set_executing (new_lp->ptid, 1); | |
e21ffe51 PA |
2131 | /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced |
2132 | resume_stop. */ | |
2133 | new_lp->last_resume_kind = resume_continue; | |
4c28f408 PA |
2134 | } |
2135 | } | |
2136 | ||
79395f92 PA |
2137 | if (status != 0) |
2138 | { | |
2139 | /* We created NEW_LP so it cannot yet contain STATUS. */ | |
2140 | gdb_assert (new_lp->status == 0); | |
2141 | ||
2142 | /* Save the wait status to report later. */ | |
2143 | if (debug_linux_nat) | |
2144 | fprintf_unfiltered (gdb_stdlog, | |
2145 | "LHEW: waitpid of new LWP %ld, " | |
2146 | "saving status %s\n", | |
2147 | (long) GET_LWP (new_lp->ptid), | |
2148 | status_to_str (status)); | |
2149 | new_lp->status = status; | |
2150 | } | |
2151 | ||
ca2163eb PA |
2152 | /* Note the need to use the low target ops to resume, to |
2153 | handle resuming with PT_SYSCALL if we have syscall | |
2154 | catchpoints. */ | |
4c28f408 PA |
2155 | if (!stopping) |
2156 | { | |
3d799a95 | 2157 | new_lp->resumed = 1; |
ca2163eb | 2158 | |
79395f92 | 2159 | if (status == 0) |
ad34eb2f | 2160 | { |
e21ffe51 | 2161 | gdb_assert (new_lp->last_resume_kind == resume_continue); |
ad34eb2f JK |
2162 | if (debug_linux_nat) |
2163 | fprintf_unfiltered (gdb_stdlog, | |
79395f92 PA |
2164 | "LHEW: resuming new LWP %ld\n", |
2165 | GET_LWP (new_lp->ptid)); | |
7b50312a PA |
2166 | if (linux_nat_prepare_to_resume != NULL) |
2167 | linux_nat_prepare_to_resume (new_lp); | |
79395f92 | 2168 | linux_ops->to_resume (linux_ops, pid_to_ptid (new_pid), |
a493e3e2 | 2169 | 0, GDB_SIGNAL_0); |
79395f92 | 2170 | new_lp->stopped = 0; |
ad34eb2f JK |
2171 | } |
2172 | } | |
d6b0e80f | 2173 | |
3d799a95 DJ |
2174 | if (debug_linux_nat) |
2175 | fprintf_unfiltered (gdb_stdlog, | |
3c4d7e12 | 2176 | "LHEW: resuming parent LWP %d\n", pid); |
7b50312a PA |
2177 | if (linux_nat_prepare_to_resume != NULL) |
2178 | linux_nat_prepare_to_resume (lp); | |
ca2163eb | 2179 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
a493e3e2 | 2180 | 0, GDB_SIGNAL_0); |
3d799a95 DJ |
2181 | |
2182 | return 1; | |
2183 | } | |
2184 | ||
2185 | return 0; | |
d6b0e80f AC |
2186 | } |
2187 | ||
3d799a95 DJ |
2188 | if (event == PTRACE_EVENT_EXEC) |
2189 | { | |
a75724bc PA |
2190 | if (debug_linux_nat) |
2191 | fprintf_unfiltered (gdb_stdlog, | |
2192 | "LHEW: Got exec event from LWP %ld\n", | |
2193 | GET_LWP (lp->ptid)); | |
2194 | ||
3d799a95 DJ |
2195 | ourstatus->kind = TARGET_WAITKIND_EXECD; |
2196 | ourstatus->value.execd_pathname | |
6d8fd2b7 | 2197 | = xstrdup (linux_child_pid_to_exec_file (pid)); |
3d799a95 | 2198 | |
6c95b8df PA |
2199 | return 0; |
2200 | } | |
2201 | ||
2202 | if (event == PTRACE_EVENT_VFORK_DONE) | |
2203 | { | |
2204 | if (current_inferior ()->waiting_for_vfork_done) | |
3d799a95 | 2205 | { |
6c95b8df | 2206 | if (debug_linux_nat) |
3e43a32a MS |
2207 | fprintf_unfiltered (gdb_stdlog, |
2208 | "LHEW: Got expected PTRACE_EVENT_" | |
2209 | "VFORK_DONE from LWP %ld: stopping\n", | |
6c95b8df | 2210 | GET_LWP (lp->ptid)); |
3d799a95 | 2211 | |
6c95b8df PA |
2212 | ourstatus->kind = TARGET_WAITKIND_VFORK_DONE; |
2213 | return 0; | |
3d799a95 DJ |
2214 | } |
2215 | ||
6c95b8df | 2216 | if (debug_linux_nat) |
3e43a32a MS |
2217 | fprintf_unfiltered (gdb_stdlog, |
2218 | "LHEW: Got PTRACE_EVENT_VFORK_DONE " | |
2219 | "from LWP %ld: resuming\n", | |
6c95b8df PA |
2220 | GET_LWP (lp->ptid)); |
2221 | ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); | |
2222 | return 1; | |
3d799a95 DJ |
2223 | } |
2224 | ||
2225 | internal_error (__FILE__, __LINE__, | |
2226 | _("unknown ptrace event %d"), event); | |
d6b0e80f AC |
2227 | } |
2228 | ||
2229 | /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has | |
2230 | exited. */ | |
2231 | ||
2232 | static int | |
2233 | wait_lwp (struct lwp_info *lp) | |
2234 | { | |
2235 | pid_t pid; | |
432b4d03 | 2236 | int status = 0; |
d6b0e80f | 2237 | int thread_dead = 0; |
432b4d03 | 2238 | sigset_t prev_mask; |
d6b0e80f AC |
2239 | |
2240 | gdb_assert (!lp->stopped); | |
2241 | gdb_assert (lp->status == 0); | |
2242 | ||
432b4d03 JK |
2243 | /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
2244 | block_child_signals (&prev_mask); | |
2245 | ||
2246 | for (;;) | |
d6b0e80f | 2247 | { |
432b4d03 JK |
2248 | /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind |
2249 | was right and we should just call sigsuspend. */ | |
2250 | ||
2251 | pid = my_waitpid (GET_LWP (lp->ptid), &status, WNOHANG); | |
d6b0e80f | 2252 | if (pid == -1 && errno == ECHILD) |
432b4d03 | 2253 | pid = my_waitpid (GET_LWP (lp->ptid), &status, __WCLONE | WNOHANG); |
a9f4bb21 PA |
2254 | if (pid == -1 && errno == ECHILD) |
2255 | { | |
2256 | /* The thread has previously exited. We need to delete it | |
2257 | now because, for some vendor 2.4 kernels with NPTL | |
2258 | support backported, there won't be an exit event unless | |
2259 | it is the main thread. 2.6 kernels will report an exit | |
2260 | event for each thread that exits, as expected. */ | |
2261 | thread_dead = 1; | |
2262 | if (debug_linux_nat) | |
2263 | fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n", | |
2264 | target_pid_to_str (lp->ptid)); | |
2265 | } | |
432b4d03 JK |
2266 | if (pid != 0) |
2267 | break; | |
2268 | ||
2269 | /* Bugs 10970, 12702. | |
2270 | Thread group leader may have exited in which case we'll lock up in | |
2271 | waitpid if there are other threads, even if they are all zombies too. | |
2272 | Basically, we're not supposed to use waitpid this way. | |
2273 | __WCLONE is not applicable for the leader so we can't use that. | |
2274 | LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED | |
2275 | process; it gets ESRCH both for the zombie and for running processes. | |
2276 | ||
2277 | As a workaround, check if we're waiting for the thread group leader and | |
2278 | if it's a zombie, and avoid calling waitpid if it is. | |
2279 | ||
2280 | This is racy, what if the tgl becomes a zombie right after we check? | |
2281 | Therefore always use WNOHANG with sigsuspend - it is equivalent to | |
5f572dec | 2282 | waiting waitpid but linux_proc_pid_is_zombie is safe this way. */ |
432b4d03 JK |
2283 | |
2284 | if (GET_PID (lp->ptid) == GET_LWP (lp->ptid) | |
5f572dec | 2285 | && linux_proc_pid_is_zombie (GET_LWP (lp->ptid))) |
d6b0e80f | 2286 | { |
d6b0e80f AC |
2287 | thread_dead = 1; |
2288 | if (debug_linux_nat) | |
432b4d03 JK |
2289 | fprintf_unfiltered (gdb_stdlog, |
2290 | "WL: Thread group leader %s vanished.\n", | |
d6b0e80f | 2291 | target_pid_to_str (lp->ptid)); |
432b4d03 | 2292 | break; |
d6b0e80f | 2293 | } |
432b4d03 JK |
2294 | |
2295 | /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers | |
2296 | get invoked despite our caller had them intentionally blocked by | |
2297 | block_child_signals. This is sensitive only to the loop of | |
2298 | linux_nat_wait_1 and there if we get called my_waitpid gets called | |
2299 | again before it gets to sigsuspend so we can safely let the handlers | |
2300 | get executed here. */ | |
2301 | ||
2302 | sigsuspend (&suspend_mask); | |
2303 | } | |
2304 | ||
2305 | restore_child_signals_mask (&prev_mask); | |
2306 | ||
d6b0e80f AC |
2307 | if (!thread_dead) |
2308 | { | |
2309 | gdb_assert (pid == GET_LWP (lp->ptid)); | |
2310 | ||
2311 | if (debug_linux_nat) | |
2312 | { | |
2313 | fprintf_unfiltered (gdb_stdlog, | |
2314 | "WL: waitpid %s received %s\n", | |
2315 | target_pid_to_str (lp->ptid), | |
2316 | status_to_str (status)); | |
2317 | } | |
d6b0e80f | 2318 | |
a9f4bb21 PA |
2319 | /* Check if the thread has exited. */ |
2320 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
2321 | { | |
2322 | thread_dead = 1; | |
2323 | if (debug_linux_nat) | |
2324 | fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n", | |
2325 | target_pid_to_str (lp->ptid)); | |
2326 | } | |
d6b0e80f AC |
2327 | } |
2328 | ||
2329 | if (thread_dead) | |
2330 | { | |
e26af52f | 2331 | exit_lwp (lp); |
d6b0e80f AC |
2332 | return 0; |
2333 | } | |
2334 | ||
2335 | gdb_assert (WIFSTOPPED (status)); | |
2336 | ||
ca2163eb PA |
2337 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2338 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2339 | { | |
2340 | /* No longer need the sysgood bit. The ptrace event ends up | |
2341 | recorded in lp->waitstatus if we care for it. We can carry | |
2342 | on handling the event like a regular SIGTRAP from here | |
2343 | on. */ | |
2344 | status = W_STOPCODE (SIGTRAP); | |
2345 | if (linux_handle_syscall_trap (lp, 1)) | |
2346 | return wait_lwp (lp); | |
2347 | } | |
2348 | ||
d6b0e80f AC |
2349 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
2350 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0) | |
2351 | { | |
2352 | if (debug_linux_nat) | |
2353 | fprintf_unfiltered (gdb_stdlog, | |
2354 | "WL: Handling extended status 0x%06x\n", | |
2355 | status); | |
3d799a95 | 2356 | if (linux_handle_extended_wait (lp, status, 1)) |
d6b0e80f AC |
2357 | return wait_lwp (lp); |
2358 | } | |
2359 | ||
2360 | return status; | |
2361 | } | |
2362 | ||
2363 | /* Send a SIGSTOP to LP. */ | |
2364 | ||
2365 | static int | |
2366 | stop_callback (struct lwp_info *lp, void *data) | |
2367 | { | |
2368 | if (!lp->stopped && !lp->signalled) | |
2369 | { | |
2370 | int ret; | |
2371 | ||
2372 | if (debug_linux_nat) | |
2373 | { | |
2374 | fprintf_unfiltered (gdb_stdlog, | |
2375 | "SC: kill %s **<SIGSTOP>**\n", | |
2376 | target_pid_to_str (lp->ptid)); | |
2377 | } | |
2378 | errno = 0; | |
2379 | ret = kill_lwp (GET_LWP (lp->ptid), SIGSTOP); | |
2380 | if (debug_linux_nat) | |
2381 | { | |
2382 | fprintf_unfiltered (gdb_stdlog, | |
2383 | "SC: lwp kill %d %s\n", | |
2384 | ret, | |
2385 | errno ? safe_strerror (errno) : "ERRNO-OK"); | |
2386 | } | |
2387 | ||
2388 | lp->signalled = 1; | |
2389 | gdb_assert (lp->status == 0); | |
2390 | } | |
2391 | ||
2392 | return 0; | |
2393 | } | |
2394 | ||
7b50312a PA |
2395 | /* Request a stop on LWP. */ |
2396 | ||
2397 | void | |
2398 | linux_stop_lwp (struct lwp_info *lwp) | |
2399 | { | |
2400 | stop_callback (lwp, NULL); | |
2401 | } | |
2402 | ||
57380f4e | 2403 | /* Return non-zero if LWP PID has a pending SIGINT. */ |
d6b0e80f AC |
2404 | |
2405 | static int | |
57380f4e DJ |
2406 | linux_nat_has_pending_sigint (int pid) |
2407 | { | |
2408 | sigset_t pending, blocked, ignored; | |
57380f4e DJ |
2409 | |
2410 | linux_proc_pending_signals (pid, &pending, &blocked, &ignored); | |
2411 | ||
2412 | if (sigismember (&pending, SIGINT) | |
2413 | && !sigismember (&ignored, SIGINT)) | |
2414 | return 1; | |
2415 | ||
2416 | return 0; | |
2417 | } | |
2418 | ||
2419 | /* Set a flag in LP indicating that we should ignore its next SIGINT. */ | |
2420 | ||
2421 | static int | |
2422 | set_ignore_sigint (struct lwp_info *lp, void *data) | |
d6b0e80f | 2423 | { |
57380f4e DJ |
2424 | /* If a thread has a pending SIGINT, consume it; otherwise, set a |
2425 | flag to consume the next one. */ | |
2426 | if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) | |
2427 | && WSTOPSIG (lp->status) == SIGINT) | |
2428 | lp->status = 0; | |
2429 | else | |
2430 | lp->ignore_sigint = 1; | |
2431 | ||
2432 | return 0; | |
2433 | } | |
2434 | ||
2435 | /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. | |
2436 | This function is called after we know the LWP has stopped; if the LWP | |
2437 | stopped before the expected SIGINT was delivered, then it will never have | |
2438 | arrived. Also, if the signal was delivered to a shared queue and consumed | |
2439 | by a different thread, it will never be delivered to this LWP. */ | |
d6b0e80f | 2440 | |
57380f4e DJ |
2441 | static void |
2442 | maybe_clear_ignore_sigint (struct lwp_info *lp) | |
2443 | { | |
2444 | if (!lp->ignore_sigint) | |
2445 | return; | |
2446 | ||
2447 | if (!linux_nat_has_pending_sigint (GET_LWP (lp->ptid))) | |
2448 | { | |
2449 | if (debug_linux_nat) | |
2450 | fprintf_unfiltered (gdb_stdlog, | |
2451 | "MCIS: Clearing bogus flag for %s\n", | |
2452 | target_pid_to_str (lp->ptid)); | |
2453 | lp->ignore_sigint = 0; | |
2454 | } | |
2455 | } | |
2456 | ||
ebec9a0f PA |
2457 | /* Fetch the possible triggered data watchpoint info and store it in |
2458 | LP. | |
2459 | ||
2460 | On some archs, like x86, that use debug registers to set | |
2461 | watchpoints, it's possible that the way to know which watched | |
2462 | address trapped, is to check the register that is used to select | |
2463 | which address to watch. Problem is, between setting the watchpoint | |
2464 | and reading back which data address trapped, the user may change | |
2465 | the set of watchpoints, and, as a consequence, GDB changes the | |
2466 | debug registers in the inferior. To avoid reading back a stale | |
2467 | stopped-data-address when that happens, we cache in LP the fact | |
2468 | that a watchpoint trapped, and the corresponding data address, as | |
2469 | soon as we see LP stop with a SIGTRAP. If GDB changes the debug | |
2470 | registers meanwhile, we have the cached data we can rely on. */ | |
2471 | ||
2472 | static void | |
2473 | save_sigtrap (struct lwp_info *lp) | |
2474 | { | |
2475 | struct cleanup *old_chain; | |
2476 | ||
2477 | if (linux_ops->to_stopped_by_watchpoint == NULL) | |
2478 | { | |
2479 | lp->stopped_by_watchpoint = 0; | |
2480 | return; | |
2481 | } | |
2482 | ||
2483 | old_chain = save_inferior_ptid (); | |
2484 | inferior_ptid = lp->ptid; | |
2485 | ||
2486 | lp->stopped_by_watchpoint = linux_ops->to_stopped_by_watchpoint (); | |
2487 | ||
2488 | if (lp->stopped_by_watchpoint) | |
2489 | { | |
2490 | if (linux_ops->to_stopped_data_address != NULL) | |
2491 | lp->stopped_data_address_p = | |
2492 | linux_ops->to_stopped_data_address (¤t_target, | |
2493 | &lp->stopped_data_address); | |
2494 | else | |
2495 | lp->stopped_data_address_p = 0; | |
2496 | } | |
2497 | ||
2498 | do_cleanups (old_chain); | |
2499 | } | |
2500 | ||
2501 | /* See save_sigtrap. */ | |
2502 | ||
2503 | static int | |
2504 | linux_nat_stopped_by_watchpoint (void) | |
2505 | { | |
2506 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2507 | ||
2508 | gdb_assert (lp != NULL); | |
2509 | ||
2510 | return lp->stopped_by_watchpoint; | |
2511 | } | |
2512 | ||
2513 | static int | |
2514 | linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p) | |
2515 | { | |
2516 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2517 | ||
2518 | gdb_assert (lp != NULL); | |
2519 | ||
2520 | *addr_p = lp->stopped_data_address; | |
2521 | ||
2522 | return lp->stopped_data_address_p; | |
2523 | } | |
2524 | ||
26ab7092 JK |
2525 | /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
2526 | ||
2527 | static int | |
2528 | sigtrap_is_event (int status) | |
2529 | { | |
2530 | return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; | |
2531 | } | |
2532 | ||
2533 | /* SIGTRAP-like events recognizer. */ | |
2534 | ||
2535 | static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event; | |
2536 | ||
00390b84 JK |
2537 | /* Check for SIGTRAP-like events in LP. */ |
2538 | ||
2539 | static int | |
2540 | linux_nat_lp_status_is_event (struct lwp_info *lp) | |
2541 | { | |
2542 | /* We check for lp->waitstatus in addition to lp->status, because we can | |
2543 | have pending process exits recorded in lp->status | |
2544 | and W_EXITCODE(0,0) == 0. We should probably have an additional | |
2545 | lp->status_p flag. */ | |
2546 | ||
2547 | return (lp->waitstatus.kind == TARGET_WAITKIND_IGNORE | |
2548 | && linux_nat_status_is_event (lp->status)); | |
2549 | } | |
2550 | ||
26ab7092 JK |
2551 | /* Set alternative SIGTRAP-like events recognizer. If |
2552 | breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be | |
2553 | applied. */ | |
2554 | ||
2555 | void | |
2556 | linux_nat_set_status_is_event (struct target_ops *t, | |
2557 | int (*status_is_event) (int status)) | |
2558 | { | |
2559 | linux_nat_status_is_event = status_is_event; | |
2560 | } | |
2561 | ||
57380f4e DJ |
2562 | /* Wait until LP is stopped. */ |
2563 | ||
2564 | static int | |
2565 | stop_wait_callback (struct lwp_info *lp, void *data) | |
2566 | { | |
6c95b8df PA |
2567 | struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid)); |
2568 | ||
2569 | /* If this is a vfork parent, bail out, it is not going to report | |
2570 | any SIGSTOP until the vfork is done with. */ | |
2571 | if (inf->vfork_child != NULL) | |
2572 | return 0; | |
2573 | ||
d6b0e80f AC |
2574 | if (!lp->stopped) |
2575 | { | |
2576 | int status; | |
2577 | ||
2578 | status = wait_lwp (lp); | |
2579 | if (status == 0) | |
2580 | return 0; | |
2581 | ||
57380f4e DJ |
2582 | if (lp->ignore_sigint && WIFSTOPPED (status) |
2583 | && WSTOPSIG (status) == SIGINT) | |
d6b0e80f | 2584 | { |
57380f4e | 2585 | lp->ignore_sigint = 0; |
d6b0e80f AC |
2586 | |
2587 | errno = 0; | |
2588 | ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); | |
2589 | if (debug_linux_nat) | |
2590 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
2591 | "PTRACE_CONT %s, 0, 0 (%s) " |
2592 | "(discarding SIGINT)\n", | |
d6b0e80f AC |
2593 | target_pid_to_str (lp->ptid), |
2594 | errno ? safe_strerror (errno) : "OK"); | |
2595 | ||
57380f4e | 2596 | return stop_wait_callback (lp, NULL); |
d6b0e80f AC |
2597 | } |
2598 | ||
57380f4e DJ |
2599 | maybe_clear_ignore_sigint (lp); |
2600 | ||
d6b0e80f AC |
2601 | if (WSTOPSIG (status) != SIGSTOP) |
2602 | { | |
e5ef252a | 2603 | /* The thread was stopped with a signal other than SIGSTOP. */ |
7feb7d06 | 2604 | |
e5ef252a PA |
2605 | save_sigtrap (lp); |
2606 | ||
2607 | if (debug_linux_nat) | |
2608 | fprintf_unfiltered (gdb_stdlog, | |
2609 | "SWC: Pending event %s in %s\n", | |
2610 | status_to_str ((int) status), | |
2611 | target_pid_to_str (lp->ptid)); | |
2612 | ||
2613 | /* Save the sigtrap event. */ | |
2614 | lp->status = status; | |
2615 | gdb_assert (!lp->stopped); | |
2616 | gdb_assert (lp->signalled); | |
2617 | lp->stopped = 1; | |
d6b0e80f AC |
2618 | } |
2619 | else | |
2620 | { | |
2621 | /* We caught the SIGSTOP that we intended to catch, so | |
2622 | there's no SIGSTOP pending. */ | |
e5ef252a PA |
2623 | |
2624 | if (debug_linux_nat) | |
2625 | fprintf_unfiltered (gdb_stdlog, | |
2626 | "SWC: Delayed SIGSTOP caught for %s.\n", | |
2627 | target_pid_to_str (lp->ptid)); | |
2628 | ||
d6b0e80f | 2629 | lp->stopped = 1; |
e5ef252a PA |
2630 | |
2631 | /* Reset SIGNALLED only after the stop_wait_callback call | |
2632 | above as it does gdb_assert on SIGNALLED. */ | |
d6b0e80f AC |
2633 | lp->signalled = 0; |
2634 | } | |
2635 | } | |
2636 | ||
2637 | return 0; | |
2638 | } | |
2639 | ||
d6b0e80f AC |
2640 | /* Return non-zero if LP has a wait status pending. */ |
2641 | ||
2642 | static int | |
2643 | status_callback (struct lwp_info *lp, void *data) | |
2644 | { | |
2645 | /* Only report a pending wait status if we pretend that this has | |
2646 | indeed been resumed. */ | |
ca2163eb PA |
2647 | if (!lp->resumed) |
2648 | return 0; | |
2649 | ||
2650 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
2651 | { | |
2652 | /* A ptrace event, like PTRACE_FORK|VFORK|EXEC, syscall event, | |
766062f6 | 2653 | or a pending process exit. Note that `W_EXITCODE(0,0) == |
ca2163eb PA |
2654 | 0', so a clean process exit can not be stored pending in |
2655 | lp->status, it is indistinguishable from | |
2656 | no-pending-status. */ | |
2657 | return 1; | |
2658 | } | |
2659 | ||
2660 | if (lp->status != 0) | |
2661 | return 1; | |
2662 | ||
2663 | return 0; | |
d6b0e80f AC |
2664 | } |
2665 | ||
2666 | /* Return non-zero if LP isn't stopped. */ | |
2667 | ||
2668 | static int | |
2669 | running_callback (struct lwp_info *lp, void *data) | |
2670 | { | |
25289eb2 PA |
2671 | return (!lp->stopped |
2672 | || ((lp->status != 0 | |
2673 | || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
2674 | && lp->resumed)); | |
d6b0e80f AC |
2675 | } |
2676 | ||
2677 | /* Count the LWP's that have had events. */ | |
2678 | ||
2679 | static int | |
2680 | count_events_callback (struct lwp_info *lp, void *data) | |
2681 | { | |
2682 | int *count = data; | |
2683 | ||
2684 | gdb_assert (count != NULL); | |
2685 | ||
e09490f1 | 2686 | /* Count only resumed LWPs that have a SIGTRAP event pending. */ |
00390b84 | 2687 | if (lp->resumed && linux_nat_lp_status_is_event (lp)) |
d6b0e80f AC |
2688 | (*count)++; |
2689 | ||
2690 | return 0; | |
2691 | } | |
2692 | ||
2693 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
2694 | ||
2695 | static int | |
2696 | select_singlestep_lwp_callback (struct lwp_info *lp, void *data) | |
2697 | { | |
25289eb2 PA |
2698 | if (lp->last_resume_kind == resume_step |
2699 | && lp->status != 0) | |
d6b0e80f AC |
2700 | return 1; |
2701 | else | |
2702 | return 0; | |
2703 | } | |
2704 | ||
2705 | /* Select the Nth LWP that has had a SIGTRAP event. */ | |
2706 | ||
2707 | static int | |
2708 | select_event_lwp_callback (struct lwp_info *lp, void *data) | |
2709 | { | |
2710 | int *selector = data; | |
2711 | ||
2712 | gdb_assert (selector != NULL); | |
2713 | ||
1777feb0 | 2714 | /* Select only resumed LWPs that have a SIGTRAP event pending. */ |
00390b84 | 2715 | if (lp->resumed && linux_nat_lp_status_is_event (lp)) |
d6b0e80f AC |
2716 | if ((*selector)-- == 0) |
2717 | return 1; | |
2718 | ||
2719 | return 0; | |
2720 | } | |
2721 | ||
710151dd PA |
2722 | static int |
2723 | cancel_breakpoint (struct lwp_info *lp) | |
2724 | { | |
2725 | /* Arrange for a breakpoint to be hit again later. We don't keep | |
2726 | the SIGTRAP status and don't forward the SIGTRAP signal to the | |
2727 | LWP. We will handle the current event, eventually we will resume | |
2728 | this LWP, and this breakpoint will trap again. | |
2729 | ||
2730 | If we do not do this, then we run the risk that the user will | |
2731 | delete or disable the breakpoint, but the LWP will have already | |
2732 | tripped on it. */ | |
2733 | ||
515630c5 UW |
2734 | struct regcache *regcache = get_thread_regcache (lp->ptid); |
2735 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
2736 | CORE_ADDR pc; | |
2737 | ||
2738 | pc = regcache_read_pc (regcache) - gdbarch_decr_pc_after_break (gdbarch); | |
6c95b8df | 2739 | if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
710151dd PA |
2740 | { |
2741 | if (debug_linux_nat) | |
2742 | fprintf_unfiltered (gdb_stdlog, | |
2743 | "CB: Push back breakpoint for %s\n", | |
2744 | target_pid_to_str (lp->ptid)); | |
2745 | ||
2746 | /* Back up the PC if necessary. */ | |
515630c5 UW |
2747 | if (gdbarch_decr_pc_after_break (gdbarch)) |
2748 | regcache_write_pc (regcache, pc); | |
2749 | ||
710151dd PA |
2750 | return 1; |
2751 | } | |
2752 | return 0; | |
2753 | } | |
2754 | ||
d6b0e80f AC |
2755 | static int |
2756 | cancel_breakpoints_callback (struct lwp_info *lp, void *data) | |
2757 | { | |
2758 | struct lwp_info *event_lp = data; | |
2759 | ||
2760 | /* Leave the LWP that has been elected to receive a SIGTRAP alone. */ | |
2761 | if (lp == event_lp) | |
2762 | return 0; | |
2763 | ||
2764 | /* If a LWP other than the LWP that we're reporting an event for has | |
2765 | hit a GDB breakpoint (as opposed to some random trap signal), | |
2766 | then just arrange for it to hit it again later. We don't keep | |
2767 | the SIGTRAP status and don't forward the SIGTRAP signal to the | |
2768 | LWP. We will handle the current event, eventually we will resume | |
2769 | all LWPs, and this one will get its breakpoint trap again. | |
2770 | ||
2771 | If we do not do this, then we run the risk that the user will | |
2772 | delete or disable the breakpoint, but the LWP will have already | |
2773 | tripped on it. */ | |
2774 | ||
00390b84 | 2775 | if (linux_nat_lp_status_is_event (lp) |
710151dd PA |
2776 | && cancel_breakpoint (lp)) |
2777 | /* Throw away the SIGTRAP. */ | |
2778 | lp->status = 0; | |
d6b0e80f AC |
2779 | |
2780 | return 0; | |
2781 | } | |
2782 | ||
2783 | /* Select one LWP out of those that have events pending. */ | |
2784 | ||
2785 | static void | |
d90e17a7 | 2786 | select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
d6b0e80f AC |
2787 | { |
2788 | int num_events = 0; | |
2789 | int random_selector; | |
2790 | struct lwp_info *event_lp; | |
2791 | ||
ac264b3b | 2792 | /* Record the wait status for the original LWP. */ |
d6b0e80f AC |
2793 | (*orig_lp)->status = *status; |
2794 | ||
2795 | /* Give preference to any LWP that is being single-stepped. */ | |
d90e17a7 PA |
2796 | event_lp = iterate_over_lwps (filter, |
2797 | select_singlestep_lwp_callback, NULL); | |
d6b0e80f AC |
2798 | if (event_lp != NULL) |
2799 | { | |
2800 | if (debug_linux_nat) | |
2801 | fprintf_unfiltered (gdb_stdlog, | |
2802 | "SEL: Select single-step %s\n", | |
2803 | target_pid_to_str (event_lp->ptid)); | |
2804 | } | |
2805 | else | |
2806 | { | |
2807 | /* No single-stepping LWP. Select one at random, out of those | |
2808 | which have had SIGTRAP events. */ | |
2809 | ||
2810 | /* First see how many SIGTRAP events we have. */ | |
d90e17a7 | 2811 | iterate_over_lwps (filter, count_events_callback, &num_events); |
d6b0e80f AC |
2812 | |
2813 | /* Now randomly pick a LWP out of those that have had a SIGTRAP. */ | |
2814 | random_selector = (int) | |
2815 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
2816 | ||
2817 | if (debug_linux_nat && num_events > 1) | |
2818 | fprintf_unfiltered (gdb_stdlog, | |
2819 | "SEL: Found %d SIGTRAP events, selecting #%d\n", | |
2820 | num_events, random_selector); | |
2821 | ||
d90e17a7 PA |
2822 | event_lp = iterate_over_lwps (filter, |
2823 | select_event_lwp_callback, | |
d6b0e80f AC |
2824 | &random_selector); |
2825 | } | |
2826 | ||
2827 | if (event_lp != NULL) | |
2828 | { | |
2829 | /* Switch the event LWP. */ | |
2830 | *orig_lp = event_lp; | |
2831 | *status = event_lp->status; | |
2832 | } | |
2833 | ||
2834 | /* Flush the wait status for the event LWP. */ | |
2835 | (*orig_lp)->status = 0; | |
2836 | } | |
2837 | ||
2838 | /* Return non-zero if LP has been resumed. */ | |
2839 | ||
2840 | static int | |
2841 | resumed_callback (struct lwp_info *lp, void *data) | |
2842 | { | |
2843 | return lp->resumed; | |
2844 | } | |
2845 | ||
12d9289a PA |
2846 | /* Stop an active thread, verify it still exists, then resume it. If |
2847 | the thread ends up with a pending status, then it is not resumed, | |
2848 | and *DATA (really a pointer to int), is set. */ | |
d6b0e80f AC |
2849 | |
2850 | static int | |
2851 | stop_and_resume_callback (struct lwp_info *lp, void *data) | |
2852 | { | |
12d9289a PA |
2853 | int *new_pending_p = data; |
2854 | ||
25289eb2 | 2855 | if (!lp->stopped) |
d6b0e80f | 2856 | { |
25289eb2 PA |
2857 | ptid_t ptid = lp->ptid; |
2858 | ||
d6b0e80f AC |
2859 | stop_callback (lp, NULL); |
2860 | stop_wait_callback (lp, NULL); | |
25289eb2 PA |
2861 | |
2862 | /* Resume if the lwp still exists, and the core wanted it | |
2863 | running. */ | |
12d9289a PA |
2864 | lp = find_lwp_pid (ptid); |
2865 | if (lp != NULL) | |
25289eb2 | 2866 | { |
12d9289a PA |
2867 | if (lp->last_resume_kind == resume_stop |
2868 | && lp->status == 0) | |
2869 | { | |
2870 | /* The core wanted the LWP to stop. Even if it stopped | |
2871 | cleanly (with SIGSTOP), leave the event pending. */ | |
2872 | if (debug_linux_nat) | |
2873 | fprintf_unfiltered (gdb_stdlog, | |
2874 | "SARC: core wanted LWP %ld stopped " | |
2875 | "(leaving SIGSTOP pending)\n", | |
2876 | GET_LWP (lp->ptid)); | |
2877 | lp->status = W_STOPCODE (SIGSTOP); | |
2878 | } | |
2879 | ||
2880 | if (lp->status == 0) | |
2881 | { | |
2882 | if (debug_linux_nat) | |
2883 | fprintf_unfiltered (gdb_stdlog, | |
2884 | "SARC: re-resuming LWP %ld\n", | |
2885 | GET_LWP (lp->ptid)); | |
e5ef252a | 2886 | resume_lwp (lp, lp->step, GDB_SIGNAL_0); |
12d9289a PA |
2887 | } |
2888 | else | |
2889 | { | |
2890 | if (debug_linux_nat) | |
2891 | fprintf_unfiltered (gdb_stdlog, | |
2892 | "SARC: not re-resuming LWP %ld " | |
2893 | "(has pending)\n", | |
2894 | GET_LWP (lp->ptid)); | |
2895 | if (new_pending_p) | |
2896 | *new_pending_p = 1; | |
2897 | } | |
25289eb2 | 2898 | } |
d6b0e80f AC |
2899 | } |
2900 | return 0; | |
2901 | } | |
2902 | ||
02f3fc28 | 2903 | /* Check if we should go on and pass this event to common code. |
12d9289a PA |
2904 | Return the affected lwp if we are, or NULL otherwise. If we stop |
2905 | all lwps temporarily, we may end up with new pending events in some | |
2906 | other lwp. In that case set *NEW_PENDING_P to true. */ | |
2907 | ||
02f3fc28 | 2908 | static struct lwp_info * |
0e5bf2a8 | 2909 | linux_nat_filter_event (int lwpid, int status, int *new_pending_p) |
02f3fc28 PA |
2910 | { |
2911 | struct lwp_info *lp; | |
2912 | ||
12d9289a PA |
2913 | *new_pending_p = 0; |
2914 | ||
02f3fc28 PA |
2915 | lp = find_lwp_pid (pid_to_ptid (lwpid)); |
2916 | ||
2917 | /* Check for stop events reported by a process we didn't already | |
2918 | know about - anything not already in our LWP list. | |
2919 | ||
2920 | If we're expecting to receive stopped processes after | |
2921 | fork, vfork, and clone events, then we'll just add the | |
2922 | new one to our list and go back to waiting for the event | |
2923 | to be reported - the stopped process might be returned | |
0e5bf2a8 PA |
2924 | from waitpid before or after the event is. |
2925 | ||
2926 | But note the case of a non-leader thread exec'ing after the | |
2927 | leader having exited, and gone from our lists. The non-leader | |
2928 | thread changes its tid to the tgid. */ | |
2929 | ||
2930 | if (WIFSTOPPED (status) && lp == NULL | |
2931 | && (WSTOPSIG (status) == SIGTRAP && status >> 16 == PTRACE_EVENT_EXEC)) | |
2932 | { | |
2933 | /* A multi-thread exec after we had seen the leader exiting. */ | |
2934 | if (debug_linux_nat) | |
2935 | fprintf_unfiltered (gdb_stdlog, | |
2936 | "LLW: Re-adding thread group leader LWP %d.\n", | |
2937 | lwpid); | |
2938 | ||
2939 | lp = add_lwp (BUILD_LWP (lwpid, lwpid)); | |
2940 | lp->stopped = 1; | |
2941 | lp->resumed = 1; | |
2942 | add_thread (lp->ptid); | |
2943 | } | |
2944 | ||
02f3fc28 PA |
2945 | if (WIFSTOPPED (status) && !lp) |
2946 | { | |
84636d28 | 2947 | add_to_pid_list (&stopped_pids, lwpid, status); |
02f3fc28 PA |
2948 | return NULL; |
2949 | } | |
2950 | ||
2951 | /* Make sure we don't report an event for the exit of an LWP not in | |
1777feb0 | 2952 | our list, i.e. not part of the current process. This can happen |
fd62cb89 | 2953 | if we detach from a program we originally forked and then it |
02f3fc28 PA |
2954 | exits. */ |
2955 | if (!WIFSTOPPED (status) && !lp) | |
2956 | return NULL; | |
2957 | ||
ca2163eb PA |
2958 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2959 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2960 | { | |
2961 | /* No longer need the sysgood bit. The ptrace event ends up | |
2962 | recorded in lp->waitstatus if we care for it. We can carry | |
2963 | on handling the event like a regular SIGTRAP from here | |
2964 | on. */ | |
2965 | status = W_STOPCODE (SIGTRAP); | |
2966 | if (linux_handle_syscall_trap (lp, 0)) | |
2967 | return NULL; | |
2968 | } | |
02f3fc28 | 2969 | |
ca2163eb PA |
2970 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
2971 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0) | |
02f3fc28 PA |
2972 | { |
2973 | if (debug_linux_nat) | |
2974 | fprintf_unfiltered (gdb_stdlog, | |
2975 | "LLW: Handling extended status 0x%06x\n", | |
2976 | status); | |
2977 | if (linux_handle_extended_wait (lp, status, 0)) | |
2978 | return NULL; | |
2979 | } | |
2980 | ||
26ab7092 | 2981 | if (linux_nat_status_is_event (status)) |
da559b09 | 2982 | save_sigtrap (lp); |
ca2163eb | 2983 | |
02f3fc28 | 2984 | /* Check if the thread has exited. */ |
d90e17a7 PA |
2985 | if ((WIFEXITED (status) || WIFSIGNALED (status)) |
2986 | && num_lwps (GET_PID (lp->ptid)) > 1) | |
02f3fc28 | 2987 | { |
9db03742 JB |
2988 | /* If this is the main thread, we must stop all threads and verify |
2989 | if they are still alive. This is because in the nptl thread model | |
2990 | on Linux 2.4, there is no signal issued for exiting LWPs | |
02f3fc28 PA |
2991 | other than the main thread. We only get the main thread exit |
2992 | signal once all child threads have already exited. If we | |
2993 | stop all the threads and use the stop_wait_callback to check | |
2994 | if they have exited we can determine whether this signal | |
2995 | should be ignored or whether it means the end of the debugged | |
2996 | application, regardless of which threading model is being | |
5d3b6af6 | 2997 | used. */ |
02f3fc28 PA |
2998 | if (GET_PID (lp->ptid) == GET_LWP (lp->ptid)) |
2999 | { | |
3000 | lp->stopped = 1; | |
d90e17a7 | 3001 | iterate_over_lwps (pid_to_ptid (GET_PID (lp->ptid)), |
12d9289a | 3002 | stop_and_resume_callback, new_pending_p); |
02f3fc28 PA |
3003 | } |
3004 | ||
3005 | if (debug_linux_nat) | |
3006 | fprintf_unfiltered (gdb_stdlog, | |
3007 | "LLW: %s exited.\n", | |
3008 | target_pid_to_str (lp->ptid)); | |
3009 | ||
d90e17a7 | 3010 | if (num_lwps (GET_PID (lp->ptid)) > 1) |
9db03742 JB |
3011 | { |
3012 | /* If there is at least one more LWP, then the exit signal | |
3013 | was not the end of the debugged application and should be | |
3014 | ignored. */ | |
3015 | exit_lwp (lp); | |
3016 | return NULL; | |
3017 | } | |
02f3fc28 PA |
3018 | } |
3019 | ||
3020 | /* Check if the current LWP has previously exited. In the nptl | |
3021 | thread model, LWPs other than the main thread do not issue | |
3022 | signals when they exit so we must check whenever the thread has | |
3023 | stopped. A similar check is made in stop_wait_callback(). */ | |
d90e17a7 | 3024 | if (num_lwps (GET_PID (lp->ptid)) > 1 && !linux_thread_alive (lp->ptid)) |
02f3fc28 | 3025 | { |
d90e17a7 PA |
3026 | ptid_t ptid = pid_to_ptid (GET_PID (lp->ptid)); |
3027 | ||
02f3fc28 PA |
3028 | if (debug_linux_nat) |
3029 | fprintf_unfiltered (gdb_stdlog, | |
3030 | "LLW: %s exited.\n", | |
3031 | target_pid_to_str (lp->ptid)); | |
3032 | ||
3033 | exit_lwp (lp); | |
3034 | ||
3035 | /* Make sure there is at least one thread running. */ | |
d90e17a7 | 3036 | gdb_assert (iterate_over_lwps (ptid, running_callback, NULL)); |
02f3fc28 PA |
3037 | |
3038 | /* Discard the event. */ | |
3039 | return NULL; | |
3040 | } | |
3041 | ||
3042 | /* Make sure we don't report a SIGSTOP that we sent ourselves in | |
3043 | an attempt to stop an LWP. */ | |
3044 | if (lp->signalled | |
3045 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) | |
3046 | { | |
3047 | if (debug_linux_nat) | |
3048 | fprintf_unfiltered (gdb_stdlog, | |
3049 | "LLW: Delayed SIGSTOP caught for %s.\n", | |
3050 | target_pid_to_str (lp->ptid)); | |
3051 | ||
02f3fc28 PA |
3052 | lp->signalled = 0; |
3053 | ||
25289eb2 PA |
3054 | if (lp->last_resume_kind != resume_stop) |
3055 | { | |
3056 | /* This is a delayed SIGSTOP. */ | |
02f3fc28 | 3057 | |
25289eb2 PA |
3058 | registers_changed (); |
3059 | ||
7b50312a PA |
3060 | if (linux_nat_prepare_to_resume != NULL) |
3061 | linux_nat_prepare_to_resume (lp); | |
25289eb2 | 3062 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
a493e3e2 | 3063 | lp->step, GDB_SIGNAL_0); |
25289eb2 PA |
3064 | if (debug_linux_nat) |
3065 | fprintf_unfiltered (gdb_stdlog, | |
3066 | "LLW: %s %s, 0, 0 (discard SIGSTOP)\n", | |
3067 | lp->step ? | |
3068 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3069 | target_pid_to_str (lp->ptid)); | |
02f3fc28 | 3070 | |
25289eb2 PA |
3071 | lp->stopped = 0; |
3072 | gdb_assert (lp->resumed); | |
02f3fc28 | 3073 | |
25289eb2 PA |
3074 | /* Discard the event. */ |
3075 | return NULL; | |
3076 | } | |
02f3fc28 PA |
3077 | } |
3078 | ||
57380f4e DJ |
3079 | /* Make sure we don't report a SIGINT that we have already displayed |
3080 | for another thread. */ | |
3081 | if (lp->ignore_sigint | |
3082 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) | |
3083 | { | |
3084 | if (debug_linux_nat) | |
3085 | fprintf_unfiltered (gdb_stdlog, | |
3086 | "LLW: Delayed SIGINT caught for %s.\n", | |
3087 | target_pid_to_str (lp->ptid)); | |
3088 | ||
3089 | /* This is a delayed SIGINT. */ | |
3090 | lp->ignore_sigint = 0; | |
3091 | ||
3092 | registers_changed (); | |
7b50312a PA |
3093 | if (linux_nat_prepare_to_resume != NULL) |
3094 | linux_nat_prepare_to_resume (lp); | |
28439f5e | 3095 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
a493e3e2 | 3096 | lp->step, GDB_SIGNAL_0); |
57380f4e DJ |
3097 | if (debug_linux_nat) |
3098 | fprintf_unfiltered (gdb_stdlog, | |
3099 | "LLW: %s %s, 0, 0 (discard SIGINT)\n", | |
3100 | lp->step ? | |
3101 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3102 | target_pid_to_str (lp->ptid)); | |
3103 | ||
3104 | lp->stopped = 0; | |
3105 | gdb_assert (lp->resumed); | |
3106 | ||
3107 | /* Discard the event. */ | |
3108 | return NULL; | |
3109 | } | |
3110 | ||
02f3fc28 PA |
3111 | /* An interesting event. */ |
3112 | gdb_assert (lp); | |
ca2163eb | 3113 | lp->status = status; |
02f3fc28 PA |
3114 | return lp; |
3115 | } | |
3116 | ||
0e5bf2a8 PA |
3117 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
3118 | their exits until all other threads in the group have exited. */ | |
3119 | ||
3120 | static void | |
3121 | check_zombie_leaders (void) | |
3122 | { | |
3123 | struct inferior *inf; | |
3124 | ||
3125 | ALL_INFERIORS (inf) | |
3126 | { | |
3127 | struct lwp_info *leader_lp; | |
3128 | ||
3129 | if (inf->pid == 0) | |
3130 | continue; | |
3131 | ||
3132 | leader_lp = find_lwp_pid (pid_to_ptid (inf->pid)); | |
3133 | if (leader_lp != NULL | |
3134 | /* Check if there are other threads in the group, as we may | |
3135 | have raced with the inferior simply exiting. */ | |
3136 | && num_lwps (inf->pid) > 1 | |
5f572dec | 3137 | && linux_proc_pid_is_zombie (inf->pid)) |
0e5bf2a8 PA |
3138 | { |
3139 | if (debug_linux_nat) | |
3140 | fprintf_unfiltered (gdb_stdlog, | |
3141 | "CZL: Thread group leader %d zombie " | |
3142 | "(it exited, or another thread execd).\n", | |
3143 | inf->pid); | |
3144 | ||
3145 | /* A leader zombie can mean one of two things: | |
3146 | ||
3147 | - It exited, and there's an exit status pending | |
3148 | available, or only the leader exited (not the whole | |
3149 | program). In the latter case, we can't waitpid the | |
3150 | leader's exit status until all other threads are gone. | |
3151 | ||
3152 | - There are 3 or more threads in the group, and a thread | |
3153 | other than the leader exec'd. On an exec, the Linux | |
3154 | kernel destroys all other threads (except the execing | |
3155 | one) in the thread group, and resets the execing thread's | |
3156 | tid to the tgid. No exit notification is sent for the | |
3157 | execing thread -- from the ptracer's perspective, it | |
3158 | appears as though the execing thread just vanishes. | |
3159 | Until we reap all other threads except the leader and the | |
3160 | execing thread, the leader will be zombie, and the | |
3161 | execing thread will be in `D (disc sleep)'. As soon as | |
3162 | all other threads are reaped, the execing thread changes | |
3163 | it's tid to the tgid, and the previous (zombie) leader | |
3164 | vanishes, giving place to the "new" leader. We could try | |
3165 | distinguishing the exit and exec cases, by waiting once | |
3166 | more, and seeing if something comes out, but it doesn't | |
3167 | sound useful. The previous leader _does_ go away, and | |
3168 | we'll re-add the new one once we see the exec event | |
3169 | (which is just the same as what would happen if the | |
3170 | previous leader did exit voluntarily before some other | |
3171 | thread execs). */ | |
3172 | ||
3173 | if (debug_linux_nat) | |
3174 | fprintf_unfiltered (gdb_stdlog, | |
3175 | "CZL: Thread group leader %d vanished.\n", | |
3176 | inf->pid); | |
3177 | exit_lwp (leader_lp); | |
3178 | } | |
3179 | } | |
3180 | } | |
3181 | ||
d6b0e80f | 3182 | static ptid_t |
7feb7d06 | 3183 | linux_nat_wait_1 (struct target_ops *ops, |
47608cb1 PA |
3184 | ptid_t ptid, struct target_waitstatus *ourstatus, |
3185 | int target_options) | |
d6b0e80f | 3186 | { |
7feb7d06 | 3187 | static sigset_t prev_mask; |
4b60df3d | 3188 | enum resume_kind last_resume_kind; |
12d9289a | 3189 | struct lwp_info *lp; |
12d9289a | 3190 | int status; |
d6b0e80f | 3191 | |
01124a23 | 3192 | if (debug_linux_nat) |
b84876c2 PA |
3193 | fprintf_unfiltered (gdb_stdlog, "LLW: enter\n"); |
3194 | ||
f973ed9c DJ |
3195 | /* The first time we get here after starting a new inferior, we may |
3196 | not have added it to the LWP list yet - this is the earliest | |
3197 | moment at which we know its PID. */ | |
d90e17a7 | 3198 | if (ptid_is_pid (inferior_ptid)) |
f973ed9c | 3199 | { |
27c9d204 PA |
3200 | /* Upgrade the main thread's ptid. */ |
3201 | thread_change_ptid (inferior_ptid, | |
3202 | BUILD_LWP (GET_PID (inferior_ptid), | |
3203 | GET_PID (inferior_ptid))); | |
3204 | ||
26cb8b7c | 3205 | lp = add_initial_lwp (inferior_ptid); |
f973ed9c DJ |
3206 | lp->resumed = 1; |
3207 | } | |
3208 | ||
12696c10 | 3209 | /* Make sure SIGCHLD is blocked until the sigsuspend below. */ |
7feb7d06 | 3210 | block_child_signals (&prev_mask); |
d6b0e80f AC |
3211 | |
3212 | retry: | |
d90e17a7 PA |
3213 | lp = NULL; |
3214 | status = 0; | |
d6b0e80f AC |
3215 | |
3216 | /* First check if there is a LWP with a wait status pending. */ | |
0e5bf2a8 | 3217 | if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) |
d6b0e80f | 3218 | { |
0e5bf2a8 | 3219 | /* Any LWP in the PTID group that's been resumed will do. */ |
d90e17a7 | 3220 | lp = iterate_over_lwps (ptid, status_callback, NULL); |
d6b0e80f AC |
3221 | if (lp) |
3222 | { | |
ca2163eb | 3223 | if (debug_linux_nat && lp->status) |
d6b0e80f AC |
3224 | fprintf_unfiltered (gdb_stdlog, |
3225 | "LLW: Using pending wait status %s for %s.\n", | |
ca2163eb | 3226 | status_to_str (lp->status), |
d6b0e80f AC |
3227 | target_pid_to_str (lp->ptid)); |
3228 | } | |
d6b0e80f AC |
3229 | } |
3230 | else if (is_lwp (ptid)) | |
3231 | { | |
3232 | if (debug_linux_nat) | |
3233 | fprintf_unfiltered (gdb_stdlog, | |
3234 | "LLW: Waiting for specific LWP %s.\n", | |
3235 | target_pid_to_str (ptid)); | |
3236 | ||
3237 | /* We have a specific LWP to check. */ | |
3238 | lp = find_lwp_pid (ptid); | |
3239 | gdb_assert (lp); | |
d6b0e80f | 3240 | |
ca2163eb | 3241 | if (debug_linux_nat && lp->status) |
d6b0e80f AC |
3242 | fprintf_unfiltered (gdb_stdlog, |
3243 | "LLW: Using pending wait status %s for %s.\n", | |
ca2163eb | 3244 | status_to_str (lp->status), |
d6b0e80f AC |
3245 | target_pid_to_str (lp->ptid)); |
3246 | ||
d90e17a7 PA |
3247 | /* We check for lp->waitstatus in addition to lp->status, |
3248 | because we can have pending process exits recorded in | |
3249 | lp->status and W_EXITCODE(0,0) == 0. We should probably have | |
3250 | an additional lp->status_p flag. */ | |
ca2163eb | 3251 | if (lp->status == 0 && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) |
d90e17a7 | 3252 | lp = NULL; |
d6b0e80f AC |
3253 | } |
3254 | ||
b84876c2 PA |
3255 | if (!target_can_async_p ()) |
3256 | { | |
3257 | /* Causes SIGINT to be passed on to the attached process. */ | |
3258 | set_sigint_trap (); | |
b84876c2 | 3259 | } |
d6b0e80f | 3260 | |
0e5bf2a8 | 3261 | /* But if we don't find a pending event, we'll have to wait. */ |
7feb7d06 | 3262 | |
d90e17a7 | 3263 | while (lp == NULL) |
d6b0e80f AC |
3264 | { |
3265 | pid_t lwpid; | |
3266 | ||
0e5bf2a8 PA |
3267 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
3268 | quirks: | |
3269 | ||
3270 | - If the thread group leader exits while other threads in the | |
3271 | thread group still exist, waitpid(TGID, ...) hangs. That | |
3272 | waitpid won't return an exit status until the other threads | |
3273 | in the group are reapped. | |
3274 | ||
3275 | - When a non-leader thread execs, that thread just vanishes | |
3276 | without reporting an exit (so we'd hang if we waited for it | |
3277 | explicitly in that case). The exec event is reported to | |
3278 | the TGID pid. */ | |
3279 | ||
3280 | errno = 0; | |
3281 | lwpid = my_waitpid (-1, &status, __WCLONE | WNOHANG); | |
3282 | if (lwpid == 0 || (lwpid == -1 && errno == ECHILD)) | |
3283 | lwpid = my_waitpid (-1, &status, WNOHANG); | |
3284 | ||
3285 | if (debug_linux_nat) | |
3286 | fprintf_unfiltered (gdb_stdlog, | |
3287 | "LNW: waitpid(-1, ...) returned %d, %s\n", | |
3288 | lwpid, errno ? safe_strerror (errno) : "ERRNO-OK"); | |
b84876c2 | 3289 | |
d6b0e80f AC |
3290 | if (lwpid > 0) |
3291 | { | |
12d9289a PA |
3292 | /* If this is true, then we paused LWPs momentarily, and may |
3293 | now have pending events to handle. */ | |
3294 | int new_pending; | |
3295 | ||
d6b0e80f AC |
3296 | if (debug_linux_nat) |
3297 | { | |
3298 | fprintf_unfiltered (gdb_stdlog, | |
3299 | "LLW: waitpid %ld received %s\n", | |
3300 | (long) lwpid, status_to_str (status)); | |
3301 | } | |
3302 | ||
0e5bf2a8 | 3303 | lp = linux_nat_filter_event (lwpid, status, &new_pending); |
d90e17a7 | 3304 | |
33355866 JK |
3305 | /* STATUS is now no longer valid, use LP->STATUS instead. */ |
3306 | status = 0; | |
3307 | ||
0e5bf2a8 | 3308 | if (lp && !ptid_match (lp->ptid, ptid)) |
d6b0e80f | 3309 | { |
e3e9f5a2 PA |
3310 | gdb_assert (lp->resumed); |
3311 | ||
d90e17a7 | 3312 | if (debug_linux_nat) |
3e43a32a MS |
3313 | fprintf (stderr, |
3314 | "LWP %ld got an event %06x, leaving pending.\n", | |
33355866 | 3315 | ptid_get_lwp (lp->ptid), lp->status); |
d90e17a7 | 3316 | |
ca2163eb | 3317 | if (WIFSTOPPED (lp->status)) |
d90e17a7 | 3318 | { |
ca2163eb | 3319 | if (WSTOPSIG (lp->status) != SIGSTOP) |
d90e17a7 | 3320 | { |
e3e9f5a2 PA |
3321 | /* Cancel breakpoint hits. The breakpoint may |
3322 | be removed before we fetch events from this | |
3323 | process to report to the core. It is best | |
3324 | not to assume the moribund breakpoints | |
3325 | heuristic always handles these cases --- it | |
3326 | could be too many events go through to the | |
3327 | core before this one is handled. All-stop | |
3328 | always cancels breakpoint hits in all | |
3329 | threads. */ | |
3330 | if (non_stop | |
00390b84 | 3331 | && linux_nat_lp_status_is_event (lp) |
e3e9f5a2 PA |
3332 | && cancel_breakpoint (lp)) |
3333 | { | |
3334 | /* Throw away the SIGTRAP. */ | |
3335 | lp->status = 0; | |
3336 | ||
3337 | if (debug_linux_nat) | |
3338 | fprintf (stderr, | |
3e43a32a MS |
3339 | "LLW: LWP %ld hit a breakpoint while" |
3340 | " waiting for another process;" | |
3341 | " cancelled it\n", | |
e3e9f5a2 PA |
3342 | ptid_get_lwp (lp->ptid)); |
3343 | } | |
3344 | lp->stopped = 1; | |
d90e17a7 PA |
3345 | } |
3346 | else | |
3347 | { | |
3348 | lp->stopped = 1; | |
3349 | lp->signalled = 0; | |
3350 | } | |
3351 | } | |
33355866 | 3352 | else if (WIFEXITED (lp->status) || WIFSIGNALED (lp->status)) |
d90e17a7 PA |
3353 | { |
3354 | if (debug_linux_nat) | |
3e43a32a MS |
3355 | fprintf (stderr, |
3356 | "Process %ld exited while stopping LWPs\n", | |
d90e17a7 PA |
3357 | ptid_get_lwp (lp->ptid)); |
3358 | ||
3359 | /* This was the last lwp in the process. Since | |
3360 | events are serialized to GDB core, and we can't | |
3361 | report this one right now, but GDB core and the | |
3362 | other target layers will want to be notified | |
3363 | about the exit code/signal, leave the status | |
3364 | pending for the next time we're able to report | |
3365 | it. */ | |
d90e17a7 PA |
3366 | |
3367 | /* Prevent trying to stop this thread again. We'll | |
3368 | never try to resume it because it has a pending | |
3369 | status. */ | |
3370 | lp->stopped = 1; | |
3371 | ||
3372 | /* Dead LWP's aren't expected to reported a pending | |
3373 | sigstop. */ | |
3374 | lp->signalled = 0; | |
3375 | ||
3376 | /* Store the pending event in the waitstatus as | |
3377 | well, because W_EXITCODE(0,0) == 0. */ | |
ca2163eb | 3378 | store_waitstatus (&lp->waitstatus, lp->status); |
d90e17a7 PA |
3379 | } |
3380 | ||
3381 | /* Keep looking. */ | |
3382 | lp = NULL; | |
d6b0e80f AC |
3383 | } |
3384 | ||
0e5bf2a8 | 3385 | if (new_pending) |
d90e17a7 | 3386 | { |
0e5bf2a8 PA |
3387 | /* Some LWP now has a pending event. Go all the way |
3388 | back to check it. */ | |
3389 | goto retry; | |
3390 | } | |
12d9289a | 3391 | |
0e5bf2a8 PA |
3392 | if (lp) |
3393 | { | |
3394 | /* We got an event to report to the core. */ | |
3395 | break; | |
d90e17a7 | 3396 | } |
0e5bf2a8 PA |
3397 | |
3398 | /* Retry until nothing comes out of waitpid. A single | |
3399 | SIGCHLD can indicate more than one child stopped. */ | |
3400 | continue; | |
d6b0e80f AC |
3401 | } |
3402 | ||
0e5bf2a8 PA |
3403 | /* Check for zombie thread group leaders. Those can't be reaped |
3404 | until all other threads in the thread group are. */ | |
3405 | check_zombie_leaders (); | |
d6b0e80f | 3406 | |
0e5bf2a8 PA |
3407 | /* If there are no resumed children left, bail. We'd be stuck |
3408 | forever in the sigsuspend call below otherwise. */ | |
3409 | if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL) | |
3410 | { | |
3411 | if (debug_linux_nat) | |
3412 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n"); | |
b84876c2 | 3413 | |
0e5bf2a8 | 3414 | ourstatus->kind = TARGET_WAITKIND_NO_RESUMED; |
b84876c2 | 3415 | |
0e5bf2a8 PA |
3416 | if (!target_can_async_p ()) |
3417 | clear_sigint_trap (); | |
b84876c2 | 3418 | |
0e5bf2a8 PA |
3419 | restore_child_signals_mask (&prev_mask); |
3420 | return minus_one_ptid; | |
d6b0e80f | 3421 | } |
28736962 | 3422 | |
0e5bf2a8 PA |
3423 | /* No interesting event to report to the core. */ |
3424 | ||
3425 | if (target_options & TARGET_WNOHANG) | |
3426 | { | |
01124a23 | 3427 | if (debug_linux_nat) |
28736962 PA |
3428 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n"); |
3429 | ||
0e5bf2a8 | 3430 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
28736962 PA |
3431 | restore_child_signals_mask (&prev_mask); |
3432 | return minus_one_ptid; | |
3433 | } | |
d6b0e80f AC |
3434 | |
3435 | /* We shouldn't end up here unless we want to try again. */ | |
d90e17a7 | 3436 | gdb_assert (lp == NULL); |
0e5bf2a8 PA |
3437 | |
3438 | /* Block until we get an event reported with SIGCHLD. */ | |
3439 | sigsuspend (&suspend_mask); | |
d6b0e80f AC |
3440 | } |
3441 | ||
b84876c2 | 3442 | if (!target_can_async_p ()) |
d26b5354 | 3443 | clear_sigint_trap (); |
d6b0e80f AC |
3444 | |
3445 | gdb_assert (lp); | |
3446 | ||
ca2163eb PA |
3447 | status = lp->status; |
3448 | lp->status = 0; | |
3449 | ||
d6b0e80f AC |
3450 | /* Don't report signals that GDB isn't interested in, such as |
3451 | signals that are neither printed nor stopped upon. Stopping all | |
3452 | threads can be a bit time-consuming so if we want decent | |
3453 | performance with heavily multi-threaded programs, especially when | |
3454 | they're using a high frequency timer, we'd better avoid it if we | |
3455 | can. */ | |
3456 | ||
3457 | if (WIFSTOPPED (status)) | |
3458 | { | |
2ea28649 | 3459 | enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status)); |
d6b0e80f | 3460 | |
2455069d UW |
3461 | /* When using hardware single-step, we need to report every signal. |
3462 | Otherwise, signals in pass_mask may be short-circuited. */ | |
d539ed7e | 3463 | if (!lp->step |
2455069d | 3464 | && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status))) |
d6b0e80f AC |
3465 | { |
3466 | /* FIMXE: kettenis/2001-06-06: Should we resume all threads | |
3467 | here? It is not clear we should. GDB may not expect | |
3468 | other threads to run. On the other hand, not resuming | |
3469 | newly attached threads may cause an unwanted delay in | |
3470 | getting them running. */ | |
3471 | registers_changed (); | |
7b50312a PA |
3472 | if (linux_nat_prepare_to_resume != NULL) |
3473 | linux_nat_prepare_to_resume (lp); | |
28439f5e | 3474 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
10d6c8cd | 3475 | lp->step, signo); |
d6b0e80f AC |
3476 | if (debug_linux_nat) |
3477 | fprintf_unfiltered (gdb_stdlog, | |
3478 | "LLW: %s %s, %s (preempt 'handle')\n", | |
3479 | lp->step ? | |
3480 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3481 | target_pid_to_str (lp->ptid), | |
a493e3e2 | 3482 | (signo != GDB_SIGNAL_0 |
2ea28649 | 3483 | ? strsignal (gdb_signal_to_host (signo)) |
423ec54c | 3484 | : "0")); |
d6b0e80f | 3485 | lp->stopped = 0; |
d6b0e80f AC |
3486 | goto retry; |
3487 | } | |
3488 | ||
1ad15515 | 3489 | if (!non_stop) |
d6b0e80f | 3490 | { |
1ad15515 PA |
3491 | /* Only do the below in all-stop, as we currently use SIGINT |
3492 | to implement target_stop (see linux_nat_stop) in | |
3493 | non-stop. */ | |
a493e3e2 | 3494 | if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0) |
1ad15515 PA |
3495 | { |
3496 | /* If ^C/BREAK is typed at the tty/console, SIGINT gets | |
3497 | forwarded to the entire process group, that is, all LWPs | |
3498 | will receive it - unless they're using CLONE_THREAD to | |
3499 | share signals. Since we only want to report it once, we | |
3500 | mark it as ignored for all LWPs except this one. */ | |
d90e17a7 PA |
3501 | iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid)), |
3502 | set_ignore_sigint, NULL); | |
1ad15515 PA |
3503 | lp->ignore_sigint = 0; |
3504 | } | |
3505 | else | |
3506 | maybe_clear_ignore_sigint (lp); | |
d6b0e80f AC |
3507 | } |
3508 | } | |
3509 | ||
3510 | /* This LWP is stopped now. */ | |
3511 | lp->stopped = 1; | |
3512 | ||
3513 | if (debug_linux_nat) | |
3514 | fprintf_unfiltered (gdb_stdlog, "LLW: Candidate event %s in %s.\n", | |
3515 | status_to_str (status), target_pid_to_str (lp->ptid)); | |
3516 | ||
4c28f408 PA |
3517 | if (!non_stop) |
3518 | { | |
3519 | /* Now stop all other LWP's ... */ | |
d90e17a7 | 3520 | iterate_over_lwps (minus_one_ptid, stop_callback, NULL); |
4c28f408 PA |
3521 | |
3522 | /* ... and wait until all of them have reported back that | |
3523 | they're no longer running. */ | |
d90e17a7 | 3524 | iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL); |
4c28f408 PA |
3525 | |
3526 | /* If we're not waiting for a specific LWP, choose an event LWP | |
3527 | from among those that have had events. Giving equal priority | |
3528 | to all LWPs that have had events helps prevent | |
3529 | starvation. */ | |
0e5bf2a8 | 3530 | if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) |
d90e17a7 | 3531 | select_event_lwp (ptid, &lp, &status); |
d6b0e80f | 3532 | |
e3e9f5a2 PA |
3533 | /* Now that we've selected our final event LWP, cancel any |
3534 | breakpoints in other LWPs that have hit a GDB breakpoint. | |
3535 | See the comment in cancel_breakpoints_callback to find out | |
3536 | why. */ | |
3537 | iterate_over_lwps (minus_one_ptid, cancel_breakpoints_callback, lp); | |
3538 | ||
4b60df3d PA |
3539 | /* We'll need this to determine whether to report a SIGSTOP as |
3540 | TARGET_WAITKIND_0. Need to take a copy because | |
3541 | resume_clear_callback clears it. */ | |
3542 | last_resume_kind = lp->last_resume_kind; | |
3543 | ||
e3e9f5a2 PA |
3544 | /* In all-stop, from the core's perspective, all LWPs are now |
3545 | stopped until a new resume action is sent over. */ | |
3546 | iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL); | |
3547 | } | |
3548 | else | |
25289eb2 | 3549 | { |
4b60df3d PA |
3550 | /* See above. */ |
3551 | last_resume_kind = lp->last_resume_kind; | |
3552 | resume_clear_callback (lp, NULL); | |
25289eb2 | 3553 | } |
d6b0e80f | 3554 | |
26ab7092 | 3555 | if (linux_nat_status_is_event (status)) |
d6b0e80f | 3556 | { |
d6b0e80f AC |
3557 | if (debug_linux_nat) |
3558 | fprintf_unfiltered (gdb_stdlog, | |
4fdebdd0 PA |
3559 | "LLW: trap ptid is %s.\n", |
3560 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 3561 | } |
d6b0e80f AC |
3562 | |
3563 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
3564 | { | |
3565 | *ourstatus = lp->waitstatus; | |
3566 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
3567 | } | |
3568 | else | |
3569 | store_waitstatus (ourstatus, status); | |
3570 | ||
01124a23 | 3571 | if (debug_linux_nat) |
b84876c2 PA |
3572 | fprintf_unfiltered (gdb_stdlog, "LLW: exit\n"); |
3573 | ||
7feb7d06 | 3574 | restore_child_signals_mask (&prev_mask); |
1e225492 | 3575 | |
4b60df3d | 3576 | if (last_resume_kind == resume_stop |
25289eb2 PA |
3577 | && ourstatus->kind == TARGET_WAITKIND_STOPPED |
3578 | && WSTOPSIG (status) == SIGSTOP) | |
3579 | { | |
3580 | /* A thread that has been requested to stop by GDB with | |
3581 | target_stop, and it stopped cleanly, so report as SIG0. The | |
3582 | use of SIGSTOP is an implementation detail. */ | |
a493e3e2 | 3583 | ourstatus->value.sig = GDB_SIGNAL_0; |
25289eb2 PA |
3584 | } |
3585 | ||
1e225492 JK |
3586 | if (ourstatus->kind == TARGET_WAITKIND_EXITED |
3587 | || ourstatus->kind == TARGET_WAITKIND_SIGNALLED) | |
3588 | lp->core = -1; | |
3589 | else | |
2e794194 | 3590 | lp->core = linux_common_core_of_thread (lp->ptid); |
1e225492 | 3591 | |
f973ed9c | 3592 | return lp->ptid; |
d6b0e80f AC |
3593 | } |
3594 | ||
e3e9f5a2 PA |
3595 | /* Resume LWPs that are currently stopped without any pending status |
3596 | to report, but are resumed from the core's perspective. */ | |
3597 | ||
3598 | static int | |
3599 | resume_stopped_resumed_lwps (struct lwp_info *lp, void *data) | |
3600 | { | |
3601 | ptid_t *wait_ptid_p = data; | |
3602 | ||
3603 | if (lp->stopped | |
3604 | && lp->resumed | |
3605 | && lp->status == 0 | |
3606 | && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) | |
3607 | { | |
336060f3 PA |
3608 | struct regcache *regcache = get_thread_regcache (lp->ptid); |
3609 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
3610 | CORE_ADDR pc = regcache_read_pc (regcache); | |
3611 | ||
e3e9f5a2 PA |
3612 | gdb_assert (is_executing (lp->ptid)); |
3613 | ||
3614 | /* Don't bother if there's a breakpoint at PC that we'd hit | |
3615 | immediately, and we're not waiting for this LWP. */ | |
3616 | if (!ptid_match (lp->ptid, *wait_ptid_p)) | |
3617 | { | |
e3e9f5a2 PA |
3618 | if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
3619 | return 0; | |
3620 | } | |
3621 | ||
3622 | if (debug_linux_nat) | |
3623 | fprintf_unfiltered (gdb_stdlog, | |
336060f3 PA |
3624 | "RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n", |
3625 | target_pid_to_str (lp->ptid), | |
3626 | paddress (gdbarch, pc), | |
3627 | lp->step); | |
e3e9f5a2 | 3628 | |
336060f3 | 3629 | registers_changed (); |
7b50312a PA |
3630 | if (linux_nat_prepare_to_resume != NULL) |
3631 | linux_nat_prepare_to_resume (lp); | |
e3e9f5a2 | 3632 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
a493e3e2 | 3633 | lp->step, GDB_SIGNAL_0); |
e3e9f5a2 | 3634 | lp->stopped = 0; |
e3e9f5a2 PA |
3635 | lp->stopped_by_watchpoint = 0; |
3636 | } | |
3637 | ||
3638 | return 0; | |
3639 | } | |
3640 | ||
7feb7d06 PA |
3641 | static ptid_t |
3642 | linux_nat_wait (struct target_ops *ops, | |
47608cb1 PA |
3643 | ptid_t ptid, struct target_waitstatus *ourstatus, |
3644 | int target_options) | |
7feb7d06 PA |
3645 | { |
3646 | ptid_t event_ptid; | |
3647 | ||
3648 | if (debug_linux_nat) | |
09826ec5 PA |
3649 | { |
3650 | char *options_string; | |
3651 | ||
3652 | options_string = target_options_to_string (target_options); | |
3653 | fprintf_unfiltered (gdb_stdlog, | |
3654 | "linux_nat_wait: [%s], [%s]\n", | |
3655 | target_pid_to_str (ptid), | |
3656 | options_string); | |
3657 | xfree (options_string); | |
3658 | } | |
7feb7d06 PA |
3659 | |
3660 | /* Flush the async file first. */ | |
3661 | if (target_can_async_p ()) | |
3662 | async_file_flush (); | |
3663 | ||
e3e9f5a2 PA |
3664 | /* Resume LWPs that are currently stopped without any pending status |
3665 | to report, but are resumed from the core's perspective. LWPs get | |
3666 | in this state if we find them stopping at a time we're not | |
3667 | interested in reporting the event (target_wait on a | |
3668 | specific_process, for example, see linux_nat_wait_1), and | |
3669 | meanwhile the event became uninteresting. Don't bother resuming | |
3670 | LWPs we're not going to wait for if they'd stop immediately. */ | |
3671 | if (non_stop) | |
3672 | iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid); | |
3673 | ||
47608cb1 | 3674 | event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options); |
7feb7d06 PA |
3675 | |
3676 | /* If we requested any event, and something came out, assume there | |
3677 | may be more. If we requested a specific lwp or process, also | |
3678 | assume there may be more. */ | |
3679 | if (target_can_async_p () | |
6953d224 PA |
3680 | && ((ourstatus->kind != TARGET_WAITKIND_IGNORE |
3681 | && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED) | |
7feb7d06 PA |
3682 | || !ptid_equal (ptid, minus_one_ptid))) |
3683 | async_file_mark (); | |
3684 | ||
3685 | /* Get ready for the next event. */ | |
3686 | if (target_can_async_p ()) | |
3687 | target_async (inferior_event_handler, 0); | |
3688 | ||
3689 | return event_ptid; | |
3690 | } | |
3691 | ||
d6b0e80f AC |
3692 | static int |
3693 | kill_callback (struct lwp_info *lp, void *data) | |
3694 | { | |
ed731959 JK |
3695 | /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
3696 | ||
3697 | errno = 0; | |
3698 | kill (GET_LWP (lp->ptid), SIGKILL); | |
3699 | if (debug_linux_nat) | |
3700 | fprintf_unfiltered (gdb_stdlog, | |
3701 | "KC: kill (SIGKILL) %s, 0, 0 (%s)\n", | |
3702 | target_pid_to_str (lp->ptid), | |
3703 | errno ? safe_strerror (errno) : "OK"); | |
3704 | ||
3705 | /* Some kernels ignore even SIGKILL for processes under ptrace. */ | |
3706 | ||
d6b0e80f AC |
3707 | errno = 0; |
3708 | ptrace (PTRACE_KILL, GET_LWP (lp->ptid), 0, 0); | |
3709 | if (debug_linux_nat) | |
3710 | fprintf_unfiltered (gdb_stdlog, | |
3711 | "KC: PTRACE_KILL %s, 0, 0 (%s)\n", | |
3712 | target_pid_to_str (lp->ptid), | |
3713 | errno ? safe_strerror (errno) : "OK"); | |
3714 | ||
3715 | return 0; | |
3716 | } | |
3717 | ||
3718 | static int | |
3719 | kill_wait_callback (struct lwp_info *lp, void *data) | |
3720 | { | |
3721 | pid_t pid; | |
3722 | ||
3723 | /* We must make sure that there are no pending events (delayed | |
3724 | SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current | |
3725 | program doesn't interfere with any following debugging session. */ | |
3726 | ||
3727 | /* For cloned processes we must check both with __WCLONE and | |
3728 | without, since the exit status of a cloned process isn't reported | |
3729 | with __WCLONE. */ | |
3730 | if (lp->cloned) | |
3731 | { | |
3732 | do | |
3733 | { | |
58aecb61 | 3734 | pid = my_waitpid (GET_LWP (lp->ptid), NULL, __WCLONE); |
e85a822c | 3735 | if (pid != (pid_t) -1) |
d6b0e80f | 3736 | { |
e85a822c DJ |
3737 | if (debug_linux_nat) |
3738 | fprintf_unfiltered (gdb_stdlog, | |
3739 | "KWC: wait %s received unknown.\n", | |
3740 | target_pid_to_str (lp->ptid)); | |
3741 | /* The Linux kernel sometimes fails to kill a thread | |
3742 | completely after PTRACE_KILL; that goes from the stop | |
3743 | point in do_fork out to the one in | |
3744 | get_signal_to_deliever and waits again. So kill it | |
3745 | again. */ | |
3746 | kill_callback (lp, NULL); | |
d6b0e80f AC |
3747 | } |
3748 | } | |
3749 | while (pid == GET_LWP (lp->ptid)); | |
3750 | ||
3751 | gdb_assert (pid == -1 && errno == ECHILD); | |
3752 | } | |
3753 | ||
3754 | do | |
3755 | { | |
58aecb61 | 3756 | pid = my_waitpid (GET_LWP (lp->ptid), NULL, 0); |
e85a822c | 3757 | if (pid != (pid_t) -1) |
d6b0e80f | 3758 | { |
e85a822c DJ |
3759 | if (debug_linux_nat) |
3760 | fprintf_unfiltered (gdb_stdlog, | |
3761 | "KWC: wait %s received unk.\n", | |
3762 | target_pid_to_str (lp->ptid)); | |
3763 | /* See the call to kill_callback above. */ | |
3764 | kill_callback (lp, NULL); | |
d6b0e80f AC |
3765 | } |
3766 | } | |
3767 | while (pid == GET_LWP (lp->ptid)); | |
3768 | ||
3769 | gdb_assert (pid == -1 && errno == ECHILD); | |
3770 | return 0; | |
3771 | } | |
3772 | ||
3773 | static void | |
7d85a9c0 | 3774 | linux_nat_kill (struct target_ops *ops) |
d6b0e80f | 3775 | { |
f973ed9c DJ |
3776 | struct target_waitstatus last; |
3777 | ptid_t last_ptid; | |
3778 | int status; | |
d6b0e80f | 3779 | |
f973ed9c DJ |
3780 | /* If we're stopped while forking and we haven't followed yet, |
3781 | kill the other task. We need to do this first because the | |
3782 | parent will be sleeping if this is a vfork. */ | |
d6b0e80f | 3783 | |
f973ed9c | 3784 | get_last_target_status (&last_ptid, &last); |
d6b0e80f | 3785 | |
f973ed9c DJ |
3786 | if (last.kind == TARGET_WAITKIND_FORKED |
3787 | || last.kind == TARGET_WAITKIND_VFORKED) | |
3788 | { | |
3a3e9ee3 | 3789 | ptrace (PT_KILL, PIDGET (last.value.related_pid), 0, 0); |
f973ed9c | 3790 | wait (&status); |
26cb8b7c PA |
3791 | |
3792 | /* Let the arch-specific native code know this process is | |
3793 | gone. */ | |
3794 | linux_nat_forget_process (PIDGET (last.value.related_pid)); | |
f973ed9c DJ |
3795 | } |
3796 | ||
3797 | if (forks_exist_p ()) | |
7feb7d06 | 3798 | linux_fork_killall (); |
f973ed9c DJ |
3799 | else |
3800 | { | |
d90e17a7 | 3801 | ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid)); |
e0881a8e | 3802 | |
4c28f408 PA |
3803 | /* Stop all threads before killing them, since ptrace requires |
3804 | that the thread is stopped to sucessfully PTRACE_KILL. */ | |
d90e17a7 | 3805 | iterate_over_lwps (ptid, stop_callback, NULL); |
4c28f408 PA |
3806 | /* ... and wait until all of them have reported back that |
3807 | they're no longer running. */ | |
d90e17a7 | 3808 | iterate_over_lwps (ptid, stop_wait_callback, NULL); |
4c28f408 | 3809 | |
f973ed9c | 3810 | /* Kill all LWP's ... */ |
d90e17a7 | 3811 | iterate_over_lwps (ptid, kill_callback, NULL); |
f973ed9c DJ |
3812 | |
3813 | /* ... and wait until we've flushed all events. */ | |
d90e17a7 | 3814 | iterate_over_lwps (ptid, kill_wait_callback, NULL); |
f973ed9c DJ |
3815 | } |
3816 | ||
3817 | target_mourn_inferior (); | |
d6b0e80f AC |
3818 | } |
3819 | ||
3820 | static void | |
136d6dae | 3821 | linux_nat_mourn_inferior (struct target_ops *ops) |
d6b0e80f | 3822 | { |
26cb8b7c PA |
3823 | int pid = ptid_get_pid (inferior_ptid); |
3824 | ||
3825 | purge_lwp_list (pid); | |
d6b0e80f | 3826 | |
f973ed9c | 3827 | if (! forks_exist_p ()) |
d90e17a7 PA |
3828 | /* Normal case, no other forks available. */ |
3829 | linux_ops->to_mourn_inferior (ops); | |
f973ed9c DJ |
3830 | else |
3831 | /* Multi-fork case. The current inferior_ptid has exited, but | |
3832 | there are other viable forks to debug. Delete the exiting | |
3833 | one and context-switch to the first available. */ | |
3834 | linux_fork_mourn_inferior (); | |
26cb8b7c PA |
3835 | |
3836 | /* Let the arch-specific native code know this process is gone. */ | |
3837 | linux_nat_forget_process (pid); | |
d6b0e80f AC |
3838 | } |
3839 | ||
5b009018 PA |
3840 | /* Convert a native/host siginfo object, into/from the siginfo in the |
3841 | layout of the inferiors' architecture. */ | |
3842 | ||
3843 | static void | |
a5362b9a | 3844 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
5b009018 PA |
3845 | { |
3846 | int done = 0; | |
3847 | ||
3848 | if (linux_nat_siginfo_fixup != NULL) | |
3849 | done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction); | |
3850 | ||
3851 | /* If there was no callback, or the callback didn't do anything, | |
3852 | then just do a straight memcpy. */ | |
3853 | if (!done) | |
3854 | { | |
3855 | if (direction == 1) | |
a5362b9a | 3856 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
5b009018 | 3857 | else |
a5362b9a | 3858 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
5b009018 PA |
3859 | } |
3860 | } | |
3861 | ||
4aa995e1 PA |
3862 | static LONGEST |
3863 | linux_xfer_siginfo (struct target_ops *ops, enum target_object object, | |
3864 | const char *annex, gdb_byte *readbuf, | |
3865 | const gdb_byte *writebuf, ULONGEST offset, LONGEST len) | |
3866 | { | |
4aa995e1 | 3867 | int pid; |
a5362b9a TS |
3868 | siginfo_t siginfo; |
3869 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; | |
4aa995e1 PA |
3870 | |
3871 | gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO); | |
3872 | gdb_assert (readbuf || writebuf); | |
3873 | ||
3874 | pid = GET_LWP (inferior_ptid); | |
3875 | if (pid == 0) | |
3876 | pid = GET_PID (inferior_ptid); | |
3877 | ||
3878 | if (offset > sizeof (siginfo)) | |
3879 | return -1; | |
3880 | ||
3881 | errno = 0; | |
3882 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3883 | if (errno != 0) | |
3884 | return -1; | |
3885 | ||
5b009018 PA |
3886 | /* When GDB is built as a 64-bit application, ptrace writes into |
3887 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
3888 | inferior with a 64-bit GDB should look the same as debugging it | |
3889 | with a 32-bit GDB, we need to convert it. GDB core always sees | |
3890 | the converted layout, so any read/write will have to be done | |
3891 | post-conversion. */ | |
3892 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
3893 | ||
4aa995e1 PA |
3894 | if (offset + len > sizeof (siginfo)) |
3895 | len = sizeof (siginfo) - offset; | |
3896 | ||
3897 | if (readbuf != NULL) | |
5b009018 | 3898 | memcpy (readbuf, inf_siginfo + offset, len); |
4aa995e1 PA |
3899 | else |
3900 | { | |
5b009018 PA |
3901 | memcpy (inf_siginfo + offset, writebuf, len); |
3902 | ||
3903 | /* Convert back to ptrace layout before flushing it out. */ | |
3904 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
3905 | ||
4aa995e1 PA |
3906 | errno = 0; |
3907 | ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3908 | if (errno != 0) | |
3909 | return -1; | |
3910 | } | |
3911 | ||
3912 | return len; | |
3913 | } | |
3914 | ||
10d6c8cd DJ |
3915 | static LONGEST |
3916 | linux_nat_xfer_partial (struct target_ops *ops, enum target_object object, | |
3917 | const char *annex, gdb_byte *readbuf, | |
3918 | const gdb_byte *writebuf, | |
3919 | ULONGEST offset, LONGEST len) | |
d6b0e80f | 3920 | { |
4aa995e1 | 3921 | struct cleanup *old_chain; |
10d6c8cd | 3922 | LONGEST xfer; |
d6b0e80f | 3923 | |
4aa995e1 PA |
3924 | if (object == TARGET_OBJECT_SIGNAL_INFO) |
3925 | return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf, | |
3926 | offset, len); | |
3927 | ||
c35b1492 PA |
3928 | /* The target is connected but no live inferior is selected. Pass |
3929 | this request down to a lower stratum (e.g., the executable | |
3930 | file). */ | |
3931 | if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid)) | |
3932 | return 0; | |
3933 | ||
4aa995e1 PA |
3934 | old_chain = save_inferior_ptid (); |
3935 | ||
d6b0e80f AC |
3936 | if (is_lwp (inferior_ptid)) |
3937 | inferior_ptid = pid_to_ptid (GET_LWP (inferior_ptid)); | |
3938 | ||
10d6c8cd DJ |
3939 | xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf, |
3940 | offset, len); | |
d6b0e80f AC |
3941 | |
3942 | do_cleanups (old_chain); | |
3943 | return xfer; | |
3944 | } | |
3945 | ||
3946 | static int | |
28439f5e | 3947 | linux_thread_alive (ptid_t ptid) |
d6b0e80f | 3948 | { |
8c6a60d1 | 3949 | int err, tmp_errno; |
4c28f408 | 3950 | |
d6b0e80f AC |
3951 | gdb_assert (is_lwp (ptid)); |
3952 | ||
4c28f408 PA |
3953 | /* Send signal 0 instead of anything ptrace, because ptracing a |
3954 | running thread errors out claiming that the thread doesn't | |
3955 | exist. */ | |
3956 | err = kill_lwp (GET_LWP (ptid), 0); | |
8c6a60d1 | 3957 | tmp_errno = errno; |
d6b0e80f AC |
3958 | if (debug_linux_nat) |
3959 | fprintf_unfiltered (gdb_stdlog, | |
4c28f408 | 3960 | "LLTA: KILL(SIG0) %s (%s)\n", |
d6b0e80f | 3961 | target_pid_to_str (ptid), |
8c6a60d1 | 3962 | err ? safe_strerror (tmp_errno) : "OK"); |
9c0dd46b | 3963 | |
4c28f408 | 3964 | if (err != 0) |
d6b0e80f AC |
3965 | return 0; |
3966 | ||
3967 | return 1; | |
3968 | } | |
3969 | ||
28439f5e PA |
3970 | static int |
3971 | linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid) | |
3972 | { | |
3973 | return linux_thread_alive (ptid); | |
3974 | } | |
3975 | ||
d6b0e80f | 3976 | static char * |
117de6a9 | 3977 | linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid) |
d6b0e80f AC |
3978 | { |
3979 | static char buf[64]; | |
3980 | ||
a0ef4274 | 3981 | if (is_lwp (ptid) |
d90e17a7 PA |
3982 | && (GET_PID (ptid) != GET_LWP (ptid) |
3983 | || num_lwps (GET_PID (ptid)) > 1)) | |
d6b0e80f AC |
3984 | { |
3985 | snprintf (buf, sizeof (buf), "LWP %ld", GET_LWP (ptid)); | |
3986 | return buf; | |
3987 | } | |
3988 | ||
3989 | return normal_pid_to_str (ptid); | |
3990 | } | |
3991 | ||
4694da01 TT |
3992 | static char * |
3993 | linux_nat_thread_name (struct thread_info *thr) | |
3994 | { | |
3995 | int pid = ptid_get_pid (thr->ptid); | |
3996 | long lwp = ptid_get_lwp (thr->ptid); | |
3997 | #define FORMAT "/proc/%d/task/%ld/comm" | |
3998 | char buf[sizeof (FORMAT) + 30]; | |
3999 | FILE *comm_file; | |
4000 | char *result = NULL; | |
4001 | ||
4002 | snprintf (buf, sizeof (buf), FORMAT, pid, lwp); | |
614c279d | 4003 | comm_file = gdb_fopen_cloexec (buf, "r"); |
4694da01 TT |
4004 | if (comm_file) |
4005 | { | |
4006 | /* Not exported by the kernel, so we define it here. */ | |
4007 | #define COMM_LEN 16 | |
4008 | static char line[COMM_LEN + 1]; | |
4009 | ||
4010 | if (fgets (line, sizeof (line), comm_file)) | |
4011 | { | |
4012 | char *nl = strchr (line, '\n'); | |
4013 | ||
4014 | if (nl) | |
4015 | *nl = '\0'; | |
4016 | if (*line != '\0') | |
4017 | result = line; | |
4018 | } | |
4019 | ||
4020 | fclose (comm_file); | |
4021 | } | |
4022 | ||
4023 | #undef COMM_LEN | |
4024 | #undef FORMAT | |
4025 | ||
4026 | return result; | |
4027 | } | |
4028 | ||
dba24537 AC |
4029 | /* Accepts an integer PID; Returns a string representing a file that |
4030 | can be opened to get the symbols for the child process. */ | |
4031 | ||
6d8fd2b7 UW |
4032 | static char * |
4033 | linux_child_pid_to_exec_file (int pid) | |
dba24537 AC |
4034 | { |
4035 | char *name1, *name2; | |
4036 | ||
d8d2a3ee PA |
4037 | name1 = xmalloc (PATH_MAX); |
4038 | name2 = xmalloc (PATH_MAX); | |
dba24537 AC |
4039 | make_cleanup (xfree, name1); |
4040 | make_cleanup (xfree, name2); | |
d8d2a3ee | 4041 | memset (name2, 0, PATH_MAX); |
dba24537 AC |
4042 | |
4043 | sprintf (name1, "/proc/%d/exe", pid); | |
d8d2a3ee | 4044 | if (readlink (name1, name2, PATH_MAX - 1) > 0) |
dba24537 AC |
4045 | return name2; |
4046 | else | |
4047 | return name1; | |
4048 | } | |
4049 | ||
dba24537 AC |
4050 | /* Records the thread's register state for the corefile note |
4051 | section. */ | |
4052 | ||
4053 | static char * | |
6432734d UW |
4054 | linux_nat_collect_thread_registers (const struct regcache *regcache, |
4055 | ptid_t ptid, bfd *obfd, | |
4056 | char *note_data, int *note_size, | |
2ea28649 | 4057 | enum gdb_signal stop_signal) |
dba24537 | 4058 | { |
6432734d | 4059 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
4f844a66 | 4060 | const struct regset *regset; |
55e969c1 | 4061 | int core_regset_p; |
6432734d UW |
4062 | gdb_gregset_t gregs; |
4063 | gdb_fpregset_t fpregs; | |
4f844a66 DM |
4064 | |
4065 | core_regset_p = gdbarch_regset_from_core_section_p (gdbarch); | |
dba24537 | 4066 | |
6432734d UW |
4067 | if (core_regset_p |
4068 | && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg", | |
4069 | sizeof (gregs))) | |
4070 | != NULL && regset->collect_regset != NULL) | |
4071 | regset->collect_regset (regset, regcache, -1, &gregs, sizeof (gregs)); | |
4f844a66 | 4072 | else |
6432734d | 4073 | fill_gregset (regcache, &gregs, -1); |
2f2241f1 | 4074 | |
6432734d UW |
4075 | note_data = (char *) elfcore_write_prstatus |
4076 | (obfd, note_data, note_size, ptid_get_lwp (ptid), | |
2ea28649 | 4077 | gdb_signal_to_host (stop_signal), &gregs); |
2f2241f1 | 4078 | |
6432734d UW |
4079 | if (core_regset_p |
4080 | && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg2", | |
4081 | sizeof (fpregs))) | |
3e43a32a | 4082 | != NULL && regset->collect_regset != NULL) |
6432734d UW |
4083 | regset->collect_regset (regset, regcache, -1, &fpregs, sizeof (fpregs)); |
4084 | else | |
4085 | fill_fpregset (regcache, &fpregs, -1); | |
17ea7499 | 4086 | |
6432734d UW |
4087 | note_data = (char *) elfcore_write_prfpreg (obfd, note_data, note_size, |
4088 | &fpregs, sizeof (fpregs)); | |
4f844a66 | 4089 | |
dba24537 AC |
4090 | return note_data; |
4091 | } | |
4092 | ||
dba24537 AC |
4093 | /* Fills the "to_make_corefile_note" target vector. Builds the note |
4094 | section for a corefile, and returns it in a malloc buffer. */ | |
4095 | ||
4096 | static char * | |
4097 | linux_nat_make_corefile_notes (bfd *obfd, int *note_size) | |
4098 | { | |
6432734d UW |
4099 | /* FIXME: uweigand/2011-10-06: Once all GNU/Linux architectures have been |
4100 | converted to gdbarch_core_regset_sections, this function can go away. */ | |
f5656ead | 4101 | return linux_make_corefile_notes (target_gdbarch (), obfd, note_size, |
6432734d | 4102 | linux_nat_collect_thread_registers); |
dba24537 AC |
4103 | } |
4104 | ||
10d6c8cd DJ |
4105 | /* Implement the to_xfer_partial interface for memory reads using the /proc |
4106 | filesystem. Because we can use a single read() call for /proc, this | |
4107 | can be much more efficient than banging away at PTRACE_PEEKTEXT, | |
4108 | but it doesn't support writes. */ | |
4109 | ||
4110 | static LONGEST | |
4111 | linux_proc_xfer_partial (struct target_ops *ops, enum target_object object, | |
4112 | const char *annex, gdb_byte *readbuf, | |
4113 | const gdb_byte *writebuf, | |
4114 | ULONGEST offset, LONGEST len) | |
dba24537 | 4115 | { |
10d6c8cd DJ |
4116 | LONGEST ret; |
4117 | int fd; | |
dba24537 AC |
4118 | char filename[64]; |
4119 | ||
10d6c8cd | 4120 | if (object != TARGET_OBJECT_MEMORY || !readbuf) |
dba24537 AC |
4121 | return 0; |
4122 | ||
4123 | /* Don't bother for one word. */ | |
4124 | if (len < 3 * sizeof (long)) | |
4125 | return 0; | |
4126 | ||
4127 | /* We could keep this file open and cache it - possibly one per | |
4128 | thread. That requires some juggling, but is even faster. */ | |
4129 | sprintf (filename, "/proc/%d/mem", PIDGET (inferior_ptid)); | |
614c279d | 4130 | fd = gdb_open_cloexec (filename, O_RDONLY | O_LARGEFILE, 0); |
dba24537 AC |
4131 | if (fd == -1) |
4132 | return 0; | |
4133 | ||
4134 | /* If pread64 is available, use it. It's faster if the kernel | |
4135 | supports it (only one syscall), and it's 64-bit safe even on | |
4136 | 32-bit platforms (for instance, SPARC debugging a SPARC64 | |
4137 | application). */ | |
4138 | #ifdef HAVE_PREAD64 | |
10d6c8cd | 4139 | if (pread64 (fd, readbuf, len, offset) != len) |
dba24537 | 4140 | #else |
10d6c8cd | 4141 | if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len) |
dba24537 AC |
4142 | #endif |
4143 | ret = 0; | |
4144 | else | |
4145 | ret = len; | |
4146 | ||
4147 | close (fd); | |
4148 | return ret; | |
4149 | } | |
4150 | ||
efcbbd14 UW |
4151 | |
4152 | /* Enumerate spufs IDs for process PID. */ | |
4153 | static LONGEST | |
4154 | spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, LONGEST len) | |
4155 | { | |
f5656ead | 4156 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
efcbbd14 UW |
4157 | LONGEST pos = 0; |
4158 | LONGEST written = 0; | |
4159 | char path[128]; | |
4160 | DIR *dir; | |
4161 | struct dirent *entry; | |
4162 | ||
4163 | xsnprintf (path, sizeof path, "/proc/%d/fd", pid); | |
4164 | dir = opendir (path); | |
4165 | if (!dir) | |
4166 | return -1; | |
4167 | ||
4168 | rewinddir (dir); | |
4169 | while ((entry = readdir (dir)) != NULL) | |
4170 | { | |
4171 | struct stat st; | |
4172 | struct statfs stfs; | |
4173 | int fd; | |
4174 | ||
4175 | fd = atoi (entry->d_name); | |
4176 | if (!fd) | |
4177 | continue; | |
4178 | ||
4179 | xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd); | |
4180 | if (stat (path, &st) != 0) | |
4181 | continue; | |
4182 | if (!S_ISDIR (st.st_mode)) | |
4183 | continue; | |
4184 | ||
4185 | if (statfs (path, &stfs) != 0) | |
4186 | continue; | |
4187 | if (stfs.f_type != SPUFS_MAGIC) | |
4188 | continue; | |
4189 | ||
4190 | if (pos >= offset && pos + 4 <= offset + len) | |
4191 | { | |
4192 | store_unsigned_integer (buf + pos - offset, 4, byte_order, fd); | |
4193 | written += 4; | |
4194 | } | |
4195 | pos += 4; | |
4196 | } | |
4197 | ||
4198 | closedir (dir); | |
4199 | return written; | |
4200 | } | |
4201 | ||
4202 | /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU | |
4203 | object type, using the /proc file system. */ | |
4204 | static LONGEST | |
4205 | linux_proc_xfer_spu (struct target_ops *ops, enum target_object object, | |
4206 | const char *annex, gdb_byte *readbuf, | |
4207 | const gdb_byte *writebuf, | |
4208 | ULONGEST offset, LONGEST len) | |
4209 | { | |
4210 | char buf[128]; | |
4211 | int fd = 0; | |
4212 | int ret = -1; | |
4213 | int pid = PIDGET (inferior_ptid); | |
4214 | ||
4215 | if (!annex) | |
4216 | { | |
4217 | if (!readbuf) | |
4218 | return -1; | |
4219 | else | |
4220 | return spu_enumerate_spu_ids (pid, readbuf, offset, len); | |
4221 | } | |
4222 | ||
4223 | xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex); | |
614c279d | 4224 | fd = gdb_open_cloexec (buf, writebuf? O_WRONLY : O_RDONLY, 0); |
efcbbd14 UW |
4225 | if (fd <= 0) |
4226 | return -1; | |
4227 | ||
4228 | if (offset != 0 | |
4229 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) | |
4230 | { | |
4231 | close (fd); | |
4232 | return 0; | |
4233 | } | |
4234 | ||
4235 | if (writebuf) | |
4236 | ret = write (fd, writebuf, (size_t) len); | |
4237 | else if (readbuf) | |
4238 | ret = read (fd, readbuf, (size_t) len); | |
4239 | ||
4240 | close (fd); | |
4241 | return ret; | |
4242 | } | |
4243 | ||
4244 | ||
dba24537 AC |
4245 | /* Parse LINE as a signal set and add its set bits to SIGS. */ |
4246 | ||
4247 | static void | |
4248 | add_line_to_sigset (const char *line, sigset_t *sigs) | |
4249 | { | |
4250 | int len = strlen (line) - 1; | |
4251 | const char *p; | |
4252 | int signum; | |
4253 | ||
4254 | if (line[len] != '\n') | |
8a3fe4f8 | 4255 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4256 | |
4257 | p = line; | |
4258 | signum = len * 4; | |
4259 | while (len-- > 0) | |
4260 | { | |
4261 | int digit; | |
4262 | ||
4263 | if (*p >= '0' && *p <= '9') | |
4264 | digit = *p - '0'; | |
4265 | else if (*p >= 'a' && *p <= 'f') | |
4266 | digit = *p - 'a' + 10; | |
4267 | else | |
8a3fe4f8 | 4268 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4269 | |
4270 | signum -= 4; | |
4271 | ||
4272 | if (digit & 1) | |
4273 | sigaddset (sigs, signum + 1); | |
4274 | if (digit & 2) | |
4275 | sigaddset (sigs, signum + 2); | |
4276 | if (digit & 4) | |
4277 | sigaddset (sigs, signum + 3); | |
4278 | if (digit & 8) | |
4279 | sigaddset (sigs, signum + 4); | |
4280 | ||
4281 | p++; | |
4282 | } | |
4283 | } | |
4284 | ||
4285 | /* Find process PID's pending signals from /proc/pid/status and set | |
4286 | SIGS to match. */ | |
4287 | ||
4288 | void | |
3e43a32a MS |
4289 | linux_proc_pending_signals (int pid, sigset_t *pending, |
4290 | sigset_t *blocked, sigset_t *ignored) | |
dba24537 AC |
4291 | { |
4292 | FILE *procfile; | |
d8d2a3ee | 4293 | char buffer[PATH_MAX], fname[PATH_MAX]; |
7c8a8b04 | 4294 | struct cleanup *cleanup; |
dba24537 AC |
4295 | |
4296 | sigemptyset (pending); | |
4297 | sigemptyset (blocked); | |
4298 | sigemptyset (ignored); | |
4299 | sprintf (fname, "/proc/%d/status", pid); | |
614c279d | 4300 | procfile = gdb_fopen_cloexec (fname, "r"); |
dba24537 | 4301 | if (procfile == NULL) |
8a3fe4f8 | 4302 | error (_("Could not open %s"), fname); |
7c8a8b04 | 4303 | cleanup = make_cleanup_fclose (procfile); |
dba24537 | 4304 | |
d8d2a3ee | 4305 | while (fgets (buffer, PATH_MAX, procfile) != NULL) |
dba24537 AC |
4306 | { |
4307 | /* Normal queued signals are on the SigPnd line in the status | |
4308 | file. However, 2.6 kernels also have a "shared" pending | |
4309 | queue for delivering signals to a thread group, so check for | |
4310 | a ShdPnd line also. | |
4311 | ||
4312 | Unfortunately some Red Hat kernels include the shared pending | |
4313 | queue but not the ShdPnd status field. */ | |
4314 | ||
4315 | if (strncmp (buffer, "SigPnd:\t", 8) == 0) | |
4316 | add_line_to_sigset (buffer + 8, pending); | |
4317 | else if (strncmp (buffer, "ShdPnd:\t", 8) == 0) | |
4318 | add_line_to_sigset (buffer + 8, pending); | |
4319 | else if (strncmp (buffer, "SigBlk:\t", 8) == 0) | |
4320 | add_line_to_sigset (buffer + 8, blocked); | |
4321 | else if (strncmp (buffer, "SigIgn:\t", 8) == 0) | |
4322 | add_line_to_sigset (buffer + 8, ignored); | |
4323 | } | |
4324 | ||
7c8a8b04 | 4325 | do_cleanups (cleanup); |
dba24537 AC |
4326 | } |
4327 | ||
07e059b5 VP |
4328 | static LONGEST |
4329 | linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object, | |
e0881a8e MS |
4330 | const char *annex, gdb_byte *readbuf, |
4331 | const gdb_byte *writebuf, ULONGEST offset, LONGEST len) | |
07e059b5 | 4332 | { |
07e059b5 VP |
4333 | gdb_assert (object == TARGET_OBJECT_OSDATA); |
4334 | ||
d26e3629 | 4335 | return linux_common_xfer_osdata (annex, readbuf, offset, len); |
07e059b5 VP |
4336 | } |
4337 | ||
10d6c8cd DJ |
4338 | static LONGEST |
4339 | linux_xfer_partial (struct target_ops *ops, enum target_object object, | |
4340 | const char *annex, gdb_byte *readbuf, | |
4341 | const gdb_byte *writebuf, ULONGEST offset, LONGEST len) | |
4342 | { | |
4343 | LONGEST xfer; | |
4344 | ||
4345 | if (object == TARGET_OBJECT_AUXV) | |
9f2982ff | 4346 | return memory_xfer_auxv (ops, object, annex, readbuf, writebuf, |
10d6c8cd DJ |
4347 | offset, len); |
4348 | ||
07e059b5 VP |
4349 | if (object == TARGET_OBJECT_OSDATA) |
4350 | return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf, | |
4351 | offset, len); | |
4352 | ||
efcbbd14 UW |
4353 | if (object == TARGET_OBJECT_SPU) |
4354 | return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf, | |
4355 | offset, len); | |
4356 | ||
8f313923 JK |
4357 | /* GDB calculates all the addresses in possibly larget width of the address. |
4358 | Address width needs to be masked before its final use - either by | |
4359 | linux_proc_xfer_partial or inf_ptrace_xfer_partial. | |
4360 | ||
4361 | Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ | |
4362 | ||
4363 | if (object == TARGET_OBJECT_MEMORY) | |
4364 | { | |
f5656ead | 4365 | int addr_bit = gdbarch_addr_bit (target_gdbarch ()); |
8f313923 JK |
4366 | |
4367 | if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) | |
4368 | offset &= ((ULONGEST) 1 << addr_bit) - 1; | |
4369 | } | |
4370 | ||
10d6c8cd DJ |
4371 | xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf, |
4372 | offset, len); | |
4373 | if (xfer != 0) | |
4374 | return xfer; | |
4375 | ||
4376 | return super_xfer_partial (ops, object, annex, readbuf, writebuf, | |
4377 | offset, len); | |
4378 | } | |
4379 | ||
5808517f YQ |
4380 | static void |
4381 | cleanup_target_stop (void *arg) | |
4382 | { | |
4383 | ptid_t *ptid = (ptid_t *) arg; | |
4384 | ||
4385 | gdb_assert (arg != NULL); | |
4386 | ||
4387 | /* Unpause all */ | |
a493e3e2 | 4388 | target_resume (*ptid, 0, GDB_SIGNAL_0); |
5808517f YQ |
4389 | } |
4390 | ||
4391 | static VEC(static_tracepoint_marker_p) * | |
4392 | linux_child_static_tracepoint_markers_by_strid (const char *strid) | |
4393 | { | |
4394 | char s[IPA_CMD_BUF_SIZE]; | |
4395 | struct cleanup *old_chain; | |
4396 | int pid = ptid_get_pid (inferior_ptid); | |
4397 | VEC(static_tracepoint_marker_p) *markers = NULL; | |
4398 | struct static_tracepoint_marker *marker = NULL; | |
4399 | char *p = s; | |
4400 | ptid_t ptid = ptid_build (pid, 0, 0); | |
4401 | ||
4402 | /* Pause all */ | |
4403 | target_stop (ptid); | |
4404 | ||
4405 | memcpy (s, "qTfSTM", sizeof ("qTfSTM")); | |
4406 | s[sizeof ("qTfSTM")] = 0; | |
4407 | ||
42476b70 | 4408 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4409 | |
4410 | old_chain = make_cleanup (free_current_marker, &marker); | |
4411 | make_cleanup (cleanup_target_stop, &ptid); | |
4412 | ||
4413 | while (*p++ == 'm') | |
4414 | { | |
4415 | if (marker == NULL) | |
4416 | marker = XCNEW (struct static_tracepoint_marker); | |
4417 | ||
4418 | do | |
4419 | { | |
4420 | parse_static_tracepoint_marker_definition (p, &p, marker); | |
4421 | ||
4422 | if (strid == NULL || strcmp (strid, marker->str_id) == 0) | |
4423 | { | |
4424 | VEC_safe_push (static_tracepoint_marker_p, | |
4425 | markers, marker); | |
4426 | marker = NULL; | |
4427 | } | |
4428 | else | |
4429 | { | |
4430 | release_static_tracepoint_marker (marker); | |
4431 | memset (marker, 0, sizeof (*marker)); | |
4432 | } | |
4433 | } | |
4434 | while (*p++ == ','); /* comma-separated list */ | |
4435 | ||
4436 | memcpy (s, "qTsSTM", sizeof ("qTsSTM")); | |
4437 | s[sizeof ("qTsSTM")] = 0; | |
42476b70 | 4438 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4439 | p = s; |
4440 | } | |
4441 | ||
4442 | do_cleanups (old_chain); | |
4443 | ||
4444 | return markers; | |
4445 | } | |
4446 | ||
e9efe249 | 4447 | /* Create a prototype generic GNU/Linux target. The client can override |
10d6c8cd DJ |
4448 | it with local methods. */ |
4449 | ||
910122bf UW |
4450 | static void |
4451 | linux_target_install_ops (struct target_ops *t) | |
10d6c8cd | 4452 | { |
6d8fd2b7 | 4453 | t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint; |
eb73ad13 | 4454 | t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint; |
6d8fd2b7 | 4455 | t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint; |
eb73ad13 | 4456 | t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint; |
6d8fd2b7 | 4457 | t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint; |
eb73ad13 | 4458 | t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint; |
a96d9b2e | 4459 | t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint; |
6d8fd2b7 | 4460 | t->to_pid_to_exec_file = linux_child_pid_to_exec_file; |
10d6c8cd | 4461 | t->to_post_startup_inferior = linux_child_post_startup_inferior; |
6d8fd2b7 UW |
4462 | t->to_post_attach = linux_child_post_attach; |
4463 | t->to_follow_fork = linux_child_follow_fork; | |
10d6c8cd DJ |
4464 | t->to_make_corefile_notes = linux_nat_make_corefile_notes; |
4465 | ||
4466 | super_xfer_partial = t->to_xfer_partial; | |
4467 | t->to_xfer_partial = linux_xfer_partial; | |
5808517f YQ |
4468 | |
4469 | t->to_static_tracepoint_markers_by_strid | |
4470 | = linux_child_static_tracepoint_markers_by_strid; | |
910122bf UW |
4471 | } |
4472 | ||
4473 | struct target_ops * | |
4474 | linux_target (void) | |
4475 | { | |
4476 | struct target_ops *t; | |
4477 | ||
4478 | t = inf_ptrace_target (); | |
4479 | linux_target_install_ops (t); | |
4480 | ||
4481 | return t; | |
4482 | } | |
4483 | ||
4484 | struct target_ops * | |
7714d83a | 4485 | linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int)) |
910122bf UW |
4486 | { |
4487 | struct target_ops *t; | |
4488 | ||
4489 | t = inf_ptrace_trad_target (register_u_offset); | |
4490 | linux_target_install_ops (t); | |
10d6c8cd | 4491 | |
10d6c8cd DJ |
4492 | return t; |
4493 | } | |
4494 | ||
b84876c2 PA |
4495 | /* target_is_async_p implementation. */ |
4496 | ||
4497 | static int | |
4498 | linux_nat_is_async_p (void) | |
4499 | { | |
4500 | /* NOTE: palves 2008-03-21: We're only async when the user requests | |
7feb7d06 | 4501 | it explicitly with the "set target-async" command. |
b84876c2 | 4502 | Someday, linux will always be async. */ |
3dd5b83d | 4503 | return target_async_permitted; |
b84876c2 PA |
4504 | } |
4505 | ||
4506 | /* target_can_async_p implementation. */ | |
4507 | ||
4508 | static int | |
4509 | linux_nat_can_async_p (void) | |
4510 | { | |
4511 | /* NOTE: palves 2008-03-21: We're only async when the user requests | |
7feb7d06 | 4512 | it explicitly with the "set target-async" command. |
b84876c2 | 4513 | Someday, linux will always be async. */ |
3dd5b83d | 4514 | return target_async_permitted; |
b84876c2 PA |
4515 | } |
4516 | ||
9908b566 VP |
4517 | static int |
4518 | linux_nat_supports_non_stop (void) | |
4519 | { | |
4520 | return 1; | |
4521 | } | |
4522 | ||
d90e17a7 PA |
4523 | /* True if we want to support multi-process. To be removed when GDB |
4524 | supports multi-exec. */ | |
4525 | ||
2277426b | 4526 | int linux_multi_process = 1; |
d90e17a7 PA |
4527 | |
4528 | static int | |
4529 | linux_nat_supports_multi_process (void) | |
4530 | { | |
4531 | return linux_multi_process; | |
4532 | } | |
4533 | ||
03583c20 UW |
4534 | static int |
4535 | linux_nat_supports_disable_randomization (void) | |
4536 | { | |
4537 | #ifdef HAVE_PERSONALITY | |
4538 | return 1; | |
4539 | #else | |
4540 | return 0; | |
4541 | #endif | |
4542 | } | |
4543 | ||
b84876c2 PA |
4544 | static int async_terminal_is_ours = 1; |
4545 | ||
4546 | /* target_terminal_inferior implementation. */ | |
4547 | ||
4548 | static void | |
4549 | linux_nat_terminal_inferior (void) | |
4550 | { | |
4551 | if (!target_is_async_p ()) | |
4552 | { | |
4553 | /* Async mode is disabled. */ | |
4554 | terminal_inferior (); | |
4555 | return; | |
4556 | } | |
4557 | ||
b84876c2 PA |
4558 | terminal_inferior (); |
4559 | ||
d9d2d8b6 | 4560 | /* Calls to target_terminal_*() are meant to be idempotent. */ |
b84876c2 PA |
4561 | if (!async_terminal_is_ours) |
4562 | return; | |
4563 | ||
4564 | delete_file_handler (input_fd); | |
4565 | async_terminal_is_ours = 0; | |
4566 | set_sigint_trap (); | |
4567 | } | |
4568 | ||
4569 | /* target_terminal_ours implementation. */ | |
4570 | ||
2c0b251b | 4571 | static void |
b84876c2 PA |
4572 | linux_nat_terminal_ours (void) |
4573 | { | |
4574 | if (!target_is_async_p ()) | |
4575 | { | |
4576 | /* Async mode is disabled. */ | |
4577 | terminal_ours (); | |
4578 | return; | |
4579 | } | |
4580 | ||
4581 | /* GDB should never give the terminal to the inferior if the | |
4582 | inferior is running in the background (run&, continue&, etc.), | |
4583 | but claiming it sure should. */ | |
4584 | terminal_ours (); | |
4585 | ||
b84876c2 PA |
4586 | if (async_terminal_is_ours) |
4587 | return; | |
4588 | ||
4589 | clear_sigint_trap (); | |
4590 | add_file_handler (input_fd, stdin_event_handler, 0); | |
4591 | async_terminal_is_ours = 1; | |
4592 | } | |
4593 | ||
4594 | static void (*async_client_callback) (enum inferior_event_type event_type, | |
4595 | void *context); | |
4596 | static void *async_client_context; | |
4597 | ||
7feb7d06 PA |
4598 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
4599 | so we notice when any child changes state, and notify the | |
4600 | event-loop; it allows us to use sigsuspend in linux_nat_wait_1 | |
4601 | above to wait for the arrival of a SIGCHLD. */ | |
4602 | ||
b84876c2 | 4603 | static void |
7feb7d06 | 4604 | sigchld_handler (int signo) |
b84876c2 | 4605 | { |
7feb7d06 PA |
4606 | int old_errno = errno; |
4607 | ||
01124a23 DE |
4608 | if (debug_linux_nat) |
4609 | ui_file_write_async_safe (gdb_stdlog, | |
4610 | "sigchld\n", sizeof ("sigchld\n") - 1); | |
7feb7d06 PA |
4611 | |
4612 | if (signo == SIGCHLD | |
4613 | && linux_nat_event_pipe[0] != -1) | |
4614 | async_file_mark (); /* Let the event loop know that there are | |
4615 | events to handle. */ | |
4616 | ||
4617 | errno = old_errno; | |
4618 | } | |
4619 | ||
4620 | /* Callback registered with the target events file descriptor. */ | |
4621 | ||
4622 | static void | |
4623 | handle_target_event (int error, gdb_client_data client_data) | |
4624 | { | |
4625 | (*async_client_callback) (INF_REG_EVENT, async_client_context); | |
4626 | } | |
4627 | ||
4628 | /* Create/destroy the target events pipe. Returns previous state. */ | |
4629 | ||
4630 | static int | |
4631 | linux_async_pipe (int enable) | |
4632 | { | |
4633 | int previous = (linux_nat_event_pipe[0] != -1); | |
4634 | ||
4635 | if (previous != enable) | |
4636 | { | |
4637 | sigset_t prev_mask; | |
4638 | ||
12696c10 PA |
4639 | /* Block child signals while we create/destroy the pipe, as |
4640 | their handler writes to it. */ | |
7feb7d06 PA |
4641 | block_child_signals (&prev_mask); |
4642 | ||
4643 | if (enable) | |
4644 | { | |
614c279d | 4645 | if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1) |
7feb7d06 PA |
4646 | internal_error (__FILE__, __LINE__, |
4647 | "creating event pipe failed."); | |
4648 | ||
4649 | fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK); | |
4650 | fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK); | |
4651 | } | |
4652 | else | |
4653 | { | |
4654 | close (linux_nat_event_pipe[0]); | |
4655 | close (linux_nat_event_pipe[1]); | |
4656 | linux_nat_event_pipe[0] = -1; | |
4657 | linux_nat_event_pipe[1] = -1; | |
4658 | } | |
4659 | ||
4660 | restore_child_signals_mask (&prev_mask); | |
4661 | } | |
4662 | ||
4663 | return previous; | |
b84876c2 PA |
4664 | } |
4665 | ||
4666 | /* target_async implementation. */ | |
4667 | ||
4668 | static void | |
4669 | linux_nat_async (void (*callback) (enum inferior_event_type event_type, | |
4670 | void *context), void *context) | |
4671 | { | |
b84876c2 PA |
4672 | if (callback != NULL) |
4673 | { | |
4674 | async_client_callback = callback; | |
4675 | async_client_context = context; | |
7feb7d06 PA |
4676 | if (!linux_async_pipe (1)) |
4677 | { | |
4678 | add_file_handler (linux_nat_event_pipe[0], | |
4679 | handle_target_event, NULL); | |
4680 | /* There may be pending events to handle. Tell the event loop | |
4681 | to poll them. */ | |
4682 | async_file_mark (); | |
4683 | } | |
b84876c2 PA |
4684 | } |
4685 | else | |
4686 | { | |
4687 | async_client_callback = callback; | |
4688 | async_client_context = context; | |
b84876c2 | 4689 | delete_file_handler (linux_nat_event_pipe[0]); |
7feb7d06 | 4690 | linux_async_pipe (0); |
b84876c2 PA |
4691 | } |
4692 | return; | |
4693 | } | |
4694 | ||
a493e3e2 | 4695 | /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other |
252fbfc8 PA |
4696 | event came out. */ |
4697 | ||
4c28f408 | 4698 | static int |
252fbfc8 | 4699 | linux_nat_stop_lwp (struct lwp_info *lwp, void *data) |
4c28f408 | 4700 | { |
d90e17a7 | 4701 | if (!lwp->stopped) |
252fbfc8 | 4702 | { |
d90e17a7 PA |
4703 | if (debug_linux_nat) |
4704 | fprintf_unfiltered (gdb_stdlog, | |
4705 | "LNSL: running -> suspending %s\n", | |
4706 | target_pid_to_str (lwp->ptid)); | |
252fbfc8 | 4707 | |
252fbfc8 | 4708 | |
25289eb2 PA |
4709 | if (lwp->last_resume_kind == resume_stop) |
4710 | { | |
4711 | if (debug_linux_nat) | |
4712 | fprintf_unfiltered (gdb_stdlog, | |
4713 | "linux-nat: already stopping LWP %ld at " | |
4714 | "GDB's request\n", | |
4715 | ptid_get_lwp (lwp->ptid)); | |
4716 | return 0; | |
4717 | } | |
252fbfc8 | 4718 | |
25289eb2 PA |
4719 | stop_callback (lwp, NULL); |
4720 | lwp->last_resume_kind = resume_stop; | |
d90e17a7 PA |
4721 | } |
4722 | else | |
4723 | { | |
4724 | /* Already known to be stopped; do nothing. */ | |
252fbfc8 | 4725 | |
d90e17a7 PA |
4726 | if (debug_linux_nat) |
4727 | { | |
e09875d4 | 4728 | if (find_thread_ptid (lwp->ptid)->stop_requested) |
3e43a32a MS |
4729 | fprintf_unfiltered (gdb_stdlog, |
4730 | "LNSL: already stopped/stop_requested %s\n", | |
d90e17a7 PA |
4731 | target_pid_to_str (lwp->ptid)); |
4732 | else | |
3e43a32a MS |
4733 | fprintf_unfiltered (gdb_stdlog, |
4734 | "LNSL: already stopped/no " | |
4735 | "stop_requested yet %s\n", | |
d90e17a7 | 4736 | target_pid_to_str (lwp->ptid)); |
252fbfc8 PA |
4737 | } |
4738 | } | |
4c28f408 PA |
4739 | return 0; |
4740 | } | |
4741 | ||
4742 | static void | |
4743 | linux_nat_stop (ptid_t ptid) | |
4744 | { | |
4745 | if (non_stop) | |
d90e17a7 | 4746 | iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL); |
4c28f408 PA |
4747 | else |
4748 | linux_ops->to_stop (ptid); | |
4749 | } | |
4750 | ||
d90e17a7 | 4751 | static void |
460014f5 | 4752 | linux_nat_close (void) |
d90e17a7 PA |
4753 | { |
4754 | /* Unregister from the event loop. */ | |
305436e0 PA |
4755 | if (linux_nat_is_async_p ()) |
4756 | linux_nat_async (NULL, 0); | |
d90e17a7 | 4757 | |
d90e17a7 | 4758 | if (linux_ops->to_close) |
460014f5 | 4759 | linux_ops->to_close (); |
d90e17a7 PA |
4760 | } |
4761 | ||
c0694254 PA |
4762 | /* When requests are passed down from the linux-nat layer to the |
4763 | single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are | |
4764 | used. The address space pointer is stored in the inferior object, | |
4765 | but the common code that is passed such ptid can't tell whether | |
4766 | lwpid is a "main" process id or not (it assumes so). We reverse | |
4767 | look up the "main" process id from the lwp here. */ | |
4768 | ||
70221824 | 4769 | static struct address_space * |
c0694254 PA |
4770 | linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid) |
4771 | { | |
4772 | struct lwp_info *lwp; | |
4773 | struct inferior *inf; | |
4774 | int pid; | |
4775 | ||
4776 | pid = GET_LWP (ptid); | |
4777 | if (GET_LWP (ptid) == 0) | |
4778 | { | |
4779 | /* An (lwpid,0,0) ptid. Look up the lwp object to get at the | |
4780 | tgid. */ | |
4781 | lwp = find_lwp_pid (ptid); | |
4782 | pid = GET_PID (lwp->ptid); | |
4783 | } | |
4784 | else | |
4785 | { | |
4786 | /* A (pid,lwpid,0) ptid. */ | |
4787 | pid = GET_PID (ptid); | |
4788 | } | |
4789 | ||
4790 | inf = find_inferior_pid (pid); | |
4791 | gdb_assert (inf != NULL); | |
4792 | return inf->aspace; | |
4793 | } | |
4794 | ||
dc146f7c VP |
4795 | /* Return the cached value of the processor core for thread PTID. */ |
4796 | ||
70221824 | 4797 | static int |
dc146f7c VP |
4798 | linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid) |
4799 | { | |
4800 | struct lwp_info *info = find_lwp_pid (ptid); | |
e0881a8e | 4801 | |
dc146f7c VP |
4802 | if (info) |
4803 | return info->core; | |
4804 | return -1; | |
4805 | } | |
4806 | ||
f973ed9c DJ |
4807 | void |
4808 | linux_nat_add_target (struct target_ops *t) | |
4809 | { | |
f973ed9c DJ |
4810 | /* Save the provided single-threaded target. We save this in a separate |
4811 | variable because another target we've inherited from (e.g. inf-ptrace) | |
4812 | may have saved a pointer to T; we want to use it for the final | |
4813 | process stratum target. */ | |
4814 | linux_ops_saved = *t; | |
4815 | linux_ops = &linux_ops_saved; | |
4816 | ||
4817 | /* Override some methods for multithreading. */ | |
b84876c2 | 4818 | t->to_create_inferior = linux_nat_create_inferior; |
f973ed9c DJ |
4819 | t->to_attach = linux_nat_attach; |
4820 | t->to_detach = linux_nat_detach; | |
4821 | t->to_resume = linux_nat_resume; | |
4822 | t->to_wait = linux_nat_wait; | |
2455069d | 4823 | t->to_pass_signals = linux_nat_pass_signals; |
f973ed9c DJ |
4824 | t->to_xfer_partial = linux_nat_xfer_partial; |
4825 | t->to_kill = linux_nat_kill; | |
4826 | t->to_mourn_inferior = linux_nat_mourn_inferior; | |
4827 | t->to_thread_alive = linux_nat_thread_alive; | |
4828 | t->to_pid_to_str = linux_nat_pid_to_str; | |
4694da01 | 4829 | t->to_thread_name = linux_nat_thread_name; |
f973ed9c | 4830 | t->to_has_thread_control = tc_schedlock; |
c0694254 | 4831 | t->to_thread_address_space = linux_nat_thread_address_space; |
ebec9a0f PA |
4832 | t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint; |
4833 | t->to_stopped_data_address = linux_nat_stopped_data_address; | |
f973ed9c | 4834 | |
b84876c2 PA |
4835 | t->to_can_async_p = linux_nat_can_async_p; |
4836 | t->to_is_async_p = linux_nat_is_async_p; | |
9908b566 | 4837 | t->to_supports_non_stop = linux_nat_supports_non_stop; |
b84876c2 | 4838 | t->to_async = linux_nat_async; |
b84876c2 PA |
4839 | t->to_terminal_inferior = linux_nat_terminal_inferior; |
4840 | t->to_terminal_ours = linux_nat_terminal_ours; | |
d90e17a7 | 4841 | t->to_close = linux_nat_close; |
b84876c2 | 4842 | |
4c28f408 PA |
4843 | /* Methods for non-stop support. */ |
4844 | t->to_stop = linux_nat_stop; | |
4845 | ||
d90e17a7 PA |
4846 | t->to_supports_multi_process = linux_nat_supports_multi_process; |
4847 | ||
03583c20 UW |
4848 | t->to_supports_disable_randomization |
4849 | = linux_nat_supports_disable_randomization; | |
4850 | ||
dc146f7c VP |
4851 | t->to_core_of_thread = linux_nat_core_of_thread; |
4852 | ||
f973ed9c DJ |
4853 | /* We don't change the stratum; this target will sit at |
4854 | process_stratum and thread_db will set at thread_stratum. This | |
4855 | is a little strange, since this is a multi-threaded-capable | |
4856 | target, but we want to be on the stack below thread_db, and we | |
4857 | also want to be used for single-threaded processes. */ | |
4858 | ||
4859 | add_target (t); | |
f973ed9c DJ |
4860 | } |
4861 | ||
9f0bdab8 DJ |
4862 | /* Register a method to call whenever a new thread is attached. */ |
4863 | void | |
7b50312a PA |
4864 | linux_nat_set_new_thread (struct target_ops *t, |
4865 | void (*new_thread) (struct lwp_info *)) | |
9f0bdab8 DJ |
4866 | { |
4867 | /* Save the pointer. We only support a single registered instance | |
4868 | of the GNU/Linux native target, so we do not need to map this to | |
4869 | T. */ | |
4870 | linux_nat_new_thread = new_thread; | |
4871 | } | |
4872 | ||
26cb8b7c PA |
4873 | /* See declaration in linux-nat.h. */ |
4874 | ||
4875 | void | |
4876 | linux_nat_set_new_fork (struct target_ops *t, | |
4877 | linux_nat_new_fork_ftype *new_fork) | |
4878 | { | |
4879 | /* Save the pointer. */ | |
4880 | linux_nat_new_fork = new_fork; | |
4881 | } | |
4882 | ||
4883 | /* See declaration in linux-nat.h. */ | |
4884 | ||
4885 | void | |
4886 | linux_nat_set_forget_process (struct target_ops *t, | |
4887 | linux_nat_forget_process_ftype *fn) | |
4888 | { | |
4889 | /* Save the pointer. */ | |
4890 | linux_nat_forget_process_hook = fn; | |
4891 | } | |
4892 | ||
4893 | /* See declaration in linux-nat.h. */ | |
4894 | ||
4895 | void | |
4896 | linux_nat_forget_process (pid_t pid) | |
4897 | { | |
4898 | if (linux_nat_forget_process_hook != NULL) | |
4899 | linux_nat_forget_process_hook (pid); | |
4900 | } | |
4901 | ||
5b009018 PA |
4902 | /* Register a method that converts a siginfo object between the layout |
4903 | that ptrace returns, and the layout in the architecture of the | |
4904 | inferior. */ | |
4905 | void | |
4906 | linux_nat_set_siginfo_fixup (struct target_ops *t, | |
a5362b9a | 4907 | int (*siginfo_fixup) (siginfo_t *, |
5b009018 PA |
4908 | gdb_byte *, |
4909 | int)) | |
4910 | { | |
4911 | /* Save the pointer. */ | |
4912 | linux_nat_siginfo_fixup = siginfo_fixup; | |
4913 | } | |
4914 | ||
7b50312a PA |
4915 | /* Register a method to call prior to resuming a thread. */ |
4916 | ||
4917 | void | |
4918 | linux_nat_set_prepare_to_resume (struct target_ops *t, | |
4919 | void (*prepare_to_resume) (struct lwp_info *)) | |
4920 | { | |
4921 | /* Save the pointer. */ | |
4922 | linux_nat_prepare_to_resume = prepare_to_resume; | |
4923 | } | |
4924 | ||
f865ee35 JK |
4925 | /* See linux-nat.h. */ |
4926 | ||
4927 | int | |
4928 | linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo) | |
9f0bdab8 | 4929 | { |
da559b09 | 4930 | int pid; |
9f0bdab8 | 4931 | |
da559b09 JK |
4932 | pid = GET_LWP (ptid); |
4933 | if (pid == 0) | |
4934 | pid = GET_PID (ptid); | |
f865ee35 | 4935 | |
da559b09 JK |
4936 | errno = 0; |
4937 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo); | |
4938 | if (errno != 0) | |
4939 | { | |
4940 | memset (siginfo, 0, sizeof (*siginfo)); | |
4941 | return 0; | |
4942 | } | |
f865ee35 | 4943 | return 1; |
9f0bdab8 DJ |
4944 | } |
4945 | ||
2c0b251b PA |
4946 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
4947 | extern initialize_file_ftype _initialize_linux_nat; | |
4948 | ||
d6b0e80f AC |
4949 | void |
4950 | _initialize_linux_nat (void) | |
4951 | { | |
ccce17b0 YQ |
4952 | add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance, |
4953 | &debug_linux_nat, _("\ | |
b84876c2 PA |
4954 | Set debugging of GNU/Linux lwp module."), _("\ |
4955 | Show debugging of GNU/Linux lwp module."), _("\ | |
4956 | Enables printf debugging output."), | |
ccce17b0 YQ |
4957 | NULL, |
4958 | show_debug_linux_nat, | |
4959 | &setdebuglist, &showdebuglist); | |
b84876c2 | 4960 | |
b84876c2 | 4961 | /* Save this mask as the default. */ |
d6b0e80f AC |
4962 | sigprocmask (SIG_SETMASK, NULL, &normal_mask); |
4963 | ||
7feb7d06 PA |
4964 | /* Install a SIGCHLD handler. */ |
4965 | sigchld_action.sa_handler = sigchld_handler; | |
4966 | sigemptyset (&sigchld_action.sa_mask); | |
4967 | sigchld_action.sa_flags = SA_RESTART; | |
b84876c2 PA |
4968 | |
4969 | /* Make it the default. */ | |
7feb7d06 | 4970 | sigaction (SIGCHLD, &sigchld_action, NULL); |
d6b0e80f AC |
4971 | |
4972 | /* Make sure we don't block SIGCHLD during a sigsuspend. */ | |
4973 | sigprocmask (SIG_SETMASK, NULL, &suspend_mask); | |
4974 | sigdelset (&suspend_mask, SIGCHLD); | |
4975 | ||
7feb7d06 | 4976 | sigemptyset (&blocked_mask); |
d6b0e80f AC |
4977 | } |
4978 | \f | |
4979 | ||
4980 | /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to | |
4981 | the GNU/Linux Threads library and therefore doesn't really belong | |
4982 | here. */ | |
4983 | ||
4984 | /* Read variable NAME in the target and return its value if found. | |
4985 | Otherwise return zero. It is assumed that the type of the variable | |
4986 | is `int'. */ | |
4987 | ||
4988 | static int | |
4989 | get_signo (const char *name) | |
4990 | { | |
4991 | struct minimal_symbol *ms; | |
4992 | int signo; | |
4993 | ||
4994 | ms = lookup_minimal_symbol (name, NULL, NULL); | |
4995 | if (ms == NULL) | |
4996 | return 0; | |
4997 | ||
8e70166d | 4998 | if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo, |
d6b0e80f AC |
4999 | sizeof (signo)) != 0) |
5000 | return 0; | |
5001 | ||
5002 | return signo; | |
5003 | } | |
5004 | ||
5005 | /* Return the set of signals used by the threads library in *SET. */ | |
5006 | ||
5007 | void | |
5008 | lin_thread_get_thread_signals (sigset_t *set) | |
5009 | { | |
5010 | struct sigaction action; | |
5011 | int restart, cancel; | |
5012 | ||
b84876c2 | 5013 | sigemptyset (&blocked_mask); |
d6b0e80f AC |
5014 | sigemptyset (set); |
5015 | ||
5016 | restart = get_signo ("__pthread_sig_restart"); | |
17fbb0bd DJ |
5017 | cancel = get_signo ("__pthread_sig_cancel"); |
5018 | ||
5019 | /* LinuxThreads normally uses the first two RT signals, but in some legacy | |
5020 | cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does | |
5021 | not provide any way for the debugger to query the signal numbers - | |
5022 | fortunately they don't change! */ | |
5023 | ||
d6b0e80f | 5024 | if (restart == 0) |
17fbb0bd | 5025 | restart = __SIGRTMIN; |
d6b0e80f | 5026 | |
d6b0e80f | 5027 | if (cancel == 0) |
17fbb0bd | 5028 | cancel = __SIGRTMIN + 1; |
d6b0e80f AC |
5029 | |
5030 | sigaddset (set, restart); | |
5031 | sigaddset (set, cancel); | |
5032 | ||
5033 | /* The GNU/Linux Threads library makes terminating threads send a | |
5034 | special "cancel" signal instead of SIGCHLD. Make sure we catch | |
5035 | those (to prevent them from terminating GDB itself, which is | |
5036 | likely to be their default action) and treat them the same way as | |
5037 | SIGCHLD. */ | |
5038 | ||
5039 | action.sa_handler = sigchld_handler; | |
5040 | sigemptyset (&action.sa_mask); | |
58aecb61 | 5041 | action.sa_flags = SA_RESTART; |
d6b0e80f AC |
5042 | sigaction (cancel, &action, NULL); |
5043 | ||
5044 | /* We block the "cancel" signal throughout this code ... */ | |
5045 | sigaddset (&blocked_mask, cancel); | |
5046 | sigprocmask (SIG_BLOCK, &blocked_mask, NULL); | |
5047 | ||
5048 | /* ... except during a sigsuspend. */ | |
5049 | sigdelset (&suspend_mask, cancel); | |
5050 | } |