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" | |
d6b0e80f | 23 | #include "gdb_string.h" |
3993f6b1 | 24 | #include "gdb_wait.h" |
d6b0e80f AC |
25 | #include "gdb_assert.h" |
26 | #ifdef HAVE_TKILL_SYSCALL | |
27 | #include <unistd.h> | |
28 | #include <sys/syscall.h> | |
29 | #endif | |
3993f6b1 | 30 | #include <sys/ptrace.h> |
0274a8ce | 31 | #include "linux-nat.h" |
af96c192 | 32 | #include "linux-ptrace.h" |
13da1c97 | 33 | #include "linux-procfs.h" |
ac264b3b | 34 | #include "linux-fork.h" |
d6b0e80f AC |
35 | #include "gdbthread.h" |
36 | #include "gdbcmd.h" | |
37 | #include "regcache.h" | |
4f844a66 | 38 | #include "regset.h" |
dab06dbe | 39 | #include "inf-child.h" |
10d6c8cd DJ |
40 | #include "inf-ptrace.h" |
41 | #include "auxv.h" | |
dba24537 | 42 | #include <sys/param.h> /* for MAXPATHLEN */ |
1777feb0 | 43 | #include <sys/procfs.h> /* for elf_gregset etc. */ |
dba24537 AC |
44 | #include "elf-bfd.h" /* for elfcore_write_* */ |
45 | #include "gregset.h" /* for gregset */ | |
46 | #include "gdbcore.h" /* for get_exec_file */ | |
47 | #include <ctype.h> /* for isdigit */ | |
1777feb0 | 48 | #include "gdbthread.h" /* for struct thread_info etc. */ |
dba24537 AC |
49 | #include "gdb_stat.h" /* for struct stat */ |
50 | #include <fcntl.h> /* for O_RDONLY */ | |
b84876c2 PA |
51 | #include "inf-loop.h" |
52 | #include "event-loop.h" | |
53 | #include "event-top.h" | |
07e059b5 VP |
54 | #include <pwd.h> |
55 | #include <sys/types.h> | |
56 | #include "gdb_dirent.h" | |
57 | #include "xml-support.h" | |
191c4426 | 58 | #include "terminal.h" |
efcbbd14 | 59 | #include <sys/vfs.h> |
6c95b8df | 60 | #include "solib.h" |
d26e3629 | 61 | #include "linux-osdata.h" |
6432734d | 62 | #include "linux-tdep.h" |
7dcd53a0 | 63 | #include "symfile.h" |
5808517f YQ |
64 | #include "agent.h" |
65 | #include "tracepoint.h" | |
87b0bb13 JK |
66 | #include "exceptions.h" |
67 | #include "linux-ptrace.h" | |
68 | #include "buffer.h" | |
6ecd4729 | 69 | #include "target-descriptions.h" |
614c279d | 70 | #include "filestuff.h" |
efcbbd14 UW |
71 | |
72 | #ifndef SPUFS_MAGIC | |
73 | #define SPUFS_MAGIC 0x23c9b64e | |
74 | #endif | |
dba24537 | 75 | |
10568435 JK |
76 | #ifdef HAVE_PERSONALITY |
77 | # include <sys/personality.h> | |
78 | # if !HAVE_DECL_ADDR_NO_RANDOMIZE | |
79 | # define ADDR_NO_RANDOMIZE 0x0040000 | |
80 | # endif | |
81 | #endif /* HAVE_PERSONALITY */ | |
82 | ||
1777feb0 | 83 | /* This comment documents high-level logic of this file. |
8a77dff3 VP |
84 | |
85 | Waiting for events in sync mode | |
86 | =============================== | |
87 | ||
88 | When waiting for an event in a specific thread, we just use waitpid, passing | |
89 | the specific pid, and not passing WNOHANG. | |
90 | ||
1777feb0 | 91 | When waiting for an event in all threads, waitpid is not quite good. Prior to |
8a77dff3 | 92 | version 2.4, Linux can either wait for event in main thread, or in secondary |
1777feb0 | 93 | threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might |
8a77dff3 VP |
94 | miss an event. The solution is to use non-blocking waitpid, together with |
95 | sigsuspend. First, we use non-blocking waitpid to get an event in the main | |
1777feb0 | 96 | process, if any. Second, we use non-blocking waitpid with the __WCLONED |
8a77dff3 VP |
97 | flag to check for events in cloned processes. If nothing is found, we use |
98 | sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something | |
99 | happened to a child process -- and SIGCHLD will be delivered both for events | |
100 | in main debugged process and in cloned processes. As soon as we know there's | |
3e43a32a MS |
101 | an event, we get back to calling nonblocking waitpid with and without |
102 | __WCLONED. | |
8a77dff3 VP |
103 | |
104 | Note that SIGCHLD should be blocked between waitpid and sigsuspend calls, | |
1777feb0 | 105 | so that we don't miss a signal. If SIGCHLD arrives in between, when it's |
8a77dff3 VP |
106 | blocked, the signal becomes pending and sigsuspend immediately |
107 | notices it and returns. | |
108 | ||
109 | Waiting for events in async mode | |
110 | ================================ | |
111 | ||
7feb7d06 PA |
112 | In async mode, GDB should always be ready to handle both user input |
113 | and target events, so neither blocking waitpid nor sigsuspend are | |
114 | viable options. Instead, we should asynchronously notify the GDB main | |
115 | event loop whenever there's an unprocessed event from the target. We | |
116 | detect asynchronous target events by handling SIGCHLD signals. To | |
117 | notify the event loop about target events, the self-pipe trick is used | |
118 | --- a pipe is registered as waitable event source in the event loop, | |
119 | the event loop select/poll's on the read end of this pipe (as well on | |
120 | other event sources, e.g., stdin), and the SIGCHLD handler writes a | |
121 | byte to this pipe. This is more portable than relying on | |
122 | pselect/ppoll, since on kernels that lack those syscalls, libc | |
123 | emulates them with select/poll+sigprocmask, and that is racy | |
124 | (a.k.a. plain broken). | |
125 | ||
126 | Obviously, if we fail to notify the event loop if there's a target | |
127 | event, it's bad. OTOH, if we notify the event loop when there's no | |
128 | event from the target, linux_nat_wait will detect that there's no real | |
129 | event to report, and return event of type TARGET_WAITKIND_IGNORE. | |
130 | This is mostly harmless, but it will waste time and is better avoided. | |
131 | ||
132 | The main design point is that every time GDB is outside linux-nat.c, | |
133 | we have a SIGCHLD handler installed that is called when something | |
134 | happens to the target and notifies the GDB event loop. Whenever GDB | |
135 | core decides to handle the event, and calls into linux-nat.c, we | |
136 | process things as in sync mode, except that the we never block in | |
137 | sigsuspend. | |
138 | ||
139 | While processing an event, we may end up momentarily blocked in | |
140 | waitpid calls. Those waitpid calls, while blocking, are guarantied to | |
141 | return quickly. E.g., in all-stop mode, before reporting to the core | |
142 | that an LWP hit a breakpoint, all LWPs are stopped by sending them | |
143 | SIGSTOP, and synchronously waiting for the SIGSTOP to be reported. | |
144 | Note that this is different from blocking indefinitely waiting for the | |
145 | next event --- here, we're already handling an event. | |
8a77dff3 VP |
146 | |
147 | Use of signals | |
148 | ============== | |
149 | ||
150 | We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another | |
151 | signal is not entirely significant; we just need for a signal to be delivered, | |
152 | so that we can intercept it. SIGSTOP's advantage is that it can not be | |
153 | blocked. A disadvantage is that it is not a real-time signal, so it can only | |
154 | be queued once; we do not keep track of other sources of SIGSTOP. | |
155 | ||
156 | Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't | |
157 | use them, because they have special behavior when the signal is generated - | |
158 | not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL | |
159 | kills the entire thread group. | |
160 | ||
161 | A delivered SIGSTOP would stop the entire thread group, not just the thread we | |
162 | tkill'd. But we never let the SIGSTOP be delivered; we always intercept and | |
163 | cancel it (by PTRACE_CONT without passing SIGSTOP). | |
164 | ||
165 | We could use a real-time signal instead. This would solve those problems; we | |
166 | could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB. | |
167 | But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH | |
168 | generates it, and there are races with trying to find a signal that is not | |
169 | blocked. */ | |
a0ef4274 | 170 | |
dba24537 AC |
171 | #ifndef O_LARGEFILE |
172 | #define O_LARGEFILE 0 | |
173 | #endif | |
0274a8ce | 174 | |
ca2163eb PA |
175 | /* Unlike other extended result codes, WSTOPSIG (status) on |
176 | PTRACE_O_TRACESYSGOOD syscall events doesn't return SIGTRAP, but | |
177 | instead SIGTRAP with bit 7 set. */ | |
178 | #define SYSCALL_SIGTRAP (SIGTRAP | 0x80) | |
179 | ||
10d6c8cd DJ |
180 | /* The single-threaded native GNU/Linux target_ops. We save a pointer for |
181 | the use of the multi-threaded target. */ | |
182 | static struct target_ops *linux_ops; | |
f973ed9c | 183 | static struct target_ops linux_ops_saved; |
10d6c8cd | 184 | |
9f0bdab8 | 185 | /* The method to call, if any, when a new thread is attached. */ |
7b50312a PA |
186 | static void (*linux_nat_new_thread) (struct lwp_info *); |
187 | ||
26cb8b7c PA |
188 | /* The method to call, if any, when a new fork is attached. */ |
189 | static linux_nat_new_fork_ftype *linux_nat_new_fork; | |
190 | ||
191 | /* The method to call, if any, when a process is no longer | |
192 | attached. */ | |
193 | static linux_nat_forget_process_ftype *linux_nat_forget_process_hook; | |
194 | ||
7b50312a PA |
195 | /* Hook to call prior to resuming a thread. */ |
196 | static void (*linux_nat_prepare_to_resume) (struct lwp_info *); | |
9f0bdab8 | 197 | |
5b009018 PA |
198 | /* The method to call, if any, when the siginfo object needs to be |
199 | converted between the layout returned by ptrace, and the layout in | |
200 | the architecture of the inferior. */ | |
a5362b9a | 201 | static int (*linux_nat_siginfo_fixup) (siginfo_t *, |
5b009018 PA |
202 | gdb_byte *, |
203 | int); | |
204 | ||
ac264b3b MS |
205 | /* The saved to_xfer_partial method, inherited from inf-ptrace.c. |
206 | Called by our to_xfer_partial. */ | |
207 | static LONGEST (*super_xfer_partial) (struct target_ops *, | |
208 | enum target_object, | |
209 | const char *, gdb_byte *, | |
210 | const gdb_byte *, | |
10d6c8cd DJ |
211 | ULONGEST, LONGEST); |
212 | ||
ccce17b0 | 213 | static unsigned int debug_linux_nat; |
920d2a44 AC |
214 | static void |
215 | show_debug_linux_nat (struct ui_file *file, int from_tty, | |
216 | struct cmd_list_element *c, const char *value) | |
217 | { | |
218 | fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"), | |
219 | value); | |
220 | } | |
d6b0e80f | 221 | |
ae087d01 DJ |
222 | struct simple_pid_list |
223 | { | |
224 | int pid; | |
3d799a95 | 225 | int status; |
ae087d01 DJ |
226 | struct simple_pid_list *next; |
227 | }; | |
228 | struct simple_pid_list *stopped_pids; | |
229 | ||
3993f6b1 DJ |
230 | /* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACEFORK |
231 | can not be used, 1 if it can. */ | |
232 | ||
233 | static int linux_supports_tracefork_flag = -1; | |
234 | ||
3e43a32a MS |
235 | /* This variable is a tri-state flag: -1 for unknown, 0 if |
236 | PTRACE_O_TRACESYSGOOD can not be used, 1 if it can. */ | |
a96d9b2e SDJ |
237 | |
238 | static int linux_supports_tracesysgood_flag = -1; | |
239 | ||
9016a515 DJ |
240 | /* If we have PTRACE_O_TRACEFORK, this flag indicates whether we also have |
241 | PTRACE_O_TRACEVFORKDONE. */ | |
242 | ||
243 | static int linux_supports_tracevforkdone_flag = -1; | |
244 | ||
a96d9b2e SDJ |
245 | /* Stores the current used ptrace() options. */ |
246 | static int current_ptrace_options = 0; | |
247 | ||
3dd5b83d PA |
248 | /* Async mode support. */ |
249 | ||
b84876c2 PA |
250 | /* The read/write ends of the pipe registered as waitable file in the |
251 | event loop. */ | |
252 | static int linux_nat_event_pipe[2] = { -1, -1 }; | |
253 | ||
7feb7d06 | 254 | /* Flush the event pipe. */ |
b84876c2 | 255 | |
7feb7d06 PA |
256 | static void |
257 | async_file_flush (void) | |
b84876c2 | 258 | { |
7feb7d06 PA |
259 | int ret; |
260 | char buf; | |
b84876c2 | 261 | |
7feb7d06 | 262 | do |
b84876c2 | 263 | { |
7feb7d06 | 264 | ret = read (linux_nat_event_pipe[0], &buf, 1); |
b84876c2 | 265 | } |
7feb7d06 | 266 | while (ret >= 0 || (ret == -1 && errno == EINTR)); |
b84876c2 PA |
267 | } |
268 | ||
7feb7d06 PA |
269 | /* Put something (anything, doesn't matter what, or how much) in event |
270 | pipe, so that the select/poll in the event-loop realizes we have | |
271 | something to process. */ | |
252fbfc8 | 272 | |
b84876c2 | 273 | static void |
7feb7d06 | 274 | async_file_mark (void) |
b84876c2 | 275 | { |
7feb7d06 | 276 | int ret; |
b84876c2 | 277 | |
7feb7d06 PA |
278 | /* It doesn't really matter what the pipe contains, as long we end |
279 | up with something in it. Might as well flush the previous | |
280 | left-overs. */ | |
281 | async_file_flush (); | |
b84876c2 | 282 | |
7feb7d06 | 283 | do |
b84876c2 | 284 | { |
7feb7d06 | 285 | ret = write (linux_nat_event_pipe[1], "+", 1); |
b84876c2 | 286 | } |
7feb7d06 | 287 | while (ret == -1 && errno == EINTR); |
b84876c2 | 288 | |
7feb7d06 PA |
289 | /* Ignore EAGAIN. If the pipe is full, the event loop will already |
290 | be awakened anyway. */ | |
b84876c2 PA |
291 | } |
292 | ||
7feb7d06 | 293 | static void linux_nat_async (void (*callback) |
3e43a32a MS |
294 | (enum inferior_event_type event_type, |
295 | void *context), | |
7feb7d06 | 296 | void *context); |
7feb7d06 PA |
297 | static int kill_lwp (int lwpid, int signo); |
298 | ||
299 | static int stop_callback (struct lwp_info *lp, void *data); | |
300 | ||
301 | static void block_child_signals (sigset_t *prev_mask); | |
302 | static void restore_child_signals_mask (sigset_t *prev_mask); | |
2277426b PA |
303 | |
304 | struct lwp_info; | |
305 | static struct lwp_info *add_lwp (ptid_t ptid); | |
306 | static void purge_lwp_list (int pid); | |
4403d8e9 | 307 | static void delete_lwp (ptid_t ptid); |
2277426b PA |
308 | static struct lwp_info *find_lwp_pid (ptid_t ptid); |
309 | ||
ae087d01 DJ |
310 | \f |
311 | /* Trivial list manipulation functions to keep track of a list of | |
312 | new stopped processes. */ | |
313 | static void | |
3d799a95 | 314 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
ae087d01 DJ |
315 | { |
316 | struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list)); | |
e0881a8e | 317 | |
ae087d01 | 318 | new_pid->pid = pid; |
3d799a95 | 319 | new_pid->status = status; |
ae087d01 DJ |
320 | new_pid->next = *listp; |
321 | *listp = new_pid; | |
322 | } | |
323 | ||
84636d28 PA |
324 | static int |
325 | in_pid_list_p (struct simple_pid_list *list, int pid) | |
326 | { | |
327 | struct simple_pid_list *p; | |
328 | ||
329 | for (p = list; p != NULL; p = p->next) | |
330 | if (p->pid == pid) | |
331 | return 1; | |
332 | return 0; | |
333 | } | |
334 | ||
ae087d01 | 335 | static int |
46a96992 | 336 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
ae087d01 DJ |
337 | { |
338 | struct simple_pid_list **p; | |
339 | ||
340 | for (p = listp; *p != NULL; p = &(*p)->next) | |
341 | if ((*p)->pid == pid) | |
342 | { | |
343 | struct simple_pid_list *next = (*p)->next; | |
e0881a8e | 344 | |
46a96992 | 345 | *statusp = (*p)->status; |
ae087d01 DJ |
346 | xfree (*p); |
347 | *p = next; | |
348 | return 1; | |
349 | } | |
350 | return 0; | |
351 | } | |
352 | ||
3993f6b1 DJ |
353 | \f |
354 | /* A helper function for linux_test_for_tracefork, called after fork (). */ | |
355 | ||
356 | static void | |
357 | linux_tracefork_child (void) | |
358 | { | |
3993f6b1 DJ |
359 | ptrace (PTRACE_TRACEME, 0, 0, 0); |
360 | kill (getpid (), SIGSTOP); | |
361 | fork (); | |
48bb3cce | 362 | _exit (0); |
3993f6b1 DJ |
363 | } |
364 | ||
7feb7d06 | 365 | /* Wrapper function for waitpid which handles EINTR. */ |
b957e937 DJ |
366 | |
367 | static int | |
46a96992 | 368 | my_waitpid (int pid, int *statusp, int flags) |
b957e937 DJ |
369 | { |
370 | int ret; | |
b84876c2 | 371 | |
b957e937 DJ |
372 | do |
373 | { | |
46a96992 | 374 | ret = waitpid (pid, statusp, flags); |
b957e937 DJ |
375 | } |
376 | while (ret == -1 && errno == EINTR); | |
377 | ||
378 | return ret; | |
379 | } | |
380 | ||
381 | /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. | |
382 | ||
383 | First, we try to enable fork tracing on ORIGINAL_PID. If this fails, | |
384 | we know that the feature is not available. This may change the tracing | |
385 | options for ORIGINAL_PID, but we'll be setting them shortly anyway. | |
386 | ||
387 | However, if it succeeds, we don't know for sure that the feature is | |
388 | available; old versions of PTRACE_SETOPTIONS ignored unknown options. We | |
3993f6b1 | 389 | create a child process, attach to it, use PTRACE_SETOPTIONS to enable |
b957e937 DJ |
390 | fork tracing, and let it fork. If the process exits, we assume that we |
391 | can't use TRACEFORK; if we get the fork notification, and we can extract | |
392 | the new child's PID, then we assume that we can. */ | |
3993f6b1 DJ |
393 | |
394 | static void | |
b957e937 | 395 | linux_test_for_tracefork (int original_pid) |
3993f6b1 DJ |
396 | { |
397 | int child_pid, ret, status; | |
398 | long second_pid; | |
7feb7d06 | 399 | sigset_t prev_mask; |
4c28f408 | 400 | |
7feb7d06 PA |
401 | /* We don't want those ptrace calls to be interrupted. */ |
402 | block_child_signals (&prev_mask); | |
3993f6b1 | 403 | |
b957e937 DJ |
404 | linux_supports_tracefork_flag = 0; |
405 | linux_supports_tracevforkdone_flag = 0; | |
406 | ||
407 | ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACEFORK); | |
408 | if (ret != 0) | |
7feb7d06 PA |
409 | { |
410 | restore_child_signals_mask (&prev_mask); | |
411 | return; | |
412 | } | |
b957e937 | 413 | |
3993f6b1 DJ |
414 | child_pid = fork (); |
415 | if (child_pid == -1) | |
e2e0b3e5 | 416 | perror_with_name (("fork")); |
3993f6b1 DJ |
417 | |
418 | if (child_pid == 0) | |
419 | linux_tracefork_child (); | |
420 | ||
b957e937 | 421 | ret = my_waitpid (child_pid, &status, 0); |
3993f6b1 | 422 | if (ret == -1) |
e2e0b3e5 | 423 | perror_with_name (("waitpid")); |
3993f6b1 | 424 | else if (ret != child_pid) |
8a3fe4f8 | 425 | error (_("linux_test_for_tracefork: waitpid: unexpected result %d."), ret); |
3993f6b1 | 426 | if (! WIFSTOPPED (status)) |
3e43a32a MS |
427 | error (_("linux_test_for_tracefork: waitpid: unexpected status %d."), |
428 | status); | |
3993f6b1 | 429 | |
3993f6b1 DJ |
430 | ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK); |
431 | if (ret != 0) | |
432 | { | |
b957e937 DJ |
433 | ret = ptrace (PTRACE_KILL, child_pid, 0, 0); |
434 | if (ret != 0) | |
435 | { | |
8a3fe4f8 | 436 | warning (_("linux_test_for_tracefork: failed to kill child")); |
7feb7d06 | 437 | restore_child_signals_mask (&prev_mask); |
b957e937 DJ |
438 | return; |
439 | } | |
440 | ||
441 | ret = my_waitpid (child_pid, &status, 0); | |
442 | if (ret != child_pid) | |
3e43a32a MS |
443 | warning (_("linux_test_for_tracefork: failed " |
444 | "to wait for killed child")); | |
b957e937 | 445 | else if (!WIFSIGNALED (status)) |
3e43a32a MS |
446 | warning (_("linux_test_for_tracefork: unexpected " |
447 | "wait status 0x%x from killed child"), status); | |
b957e937 | 448 | |
7feb7d06 | 449 | restore_child_signals_mask (&prev_mask); |
3993f6b1 DJ |
450 | return; |
451 | } | |
452 | ||
9016a515 DJ |
453 | /* Check whether PTRACE_O_TRACEVFORKDONE is available. */ |
454 | ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, | |
455 | PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORKDONE); | |
456 | linux_supports_tracevforkdone_flag = (ret == 0); | |
457 | ||
b957e937 DJ |
458 | ret = ptrace (PTRACE_CONT, child_pid, 0, 0); |
459 | if (ret != 0) | |
8a3fe4f8 | 460 | warning (_("linux_test_for_tracefork: failed to resume child")); |
b957e937 DJ |
461 | |
462 | ret = my_waitpid (child_pid, &status, 0); | |
463 | ||
3993f6b1 DJ |
464 | if (ret == child_pid && WIFSTOPPED (status) |
465 | && status >> 16 == PTRACE_EVENT_FORK) | |
466 | { | |
467 | second_pid = 0; | |
468 | ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid); | |
469 | if (ret == 0 && second_pid != 0) | |
470 | { | |
471 | int second_status; | |
472 | ||
473 | linux_supports_tracefork_flag = 1; | |
b957e937 DJ |
474 | my_waitpid (second_pid, &second_status, 0); |
475 | ret = ptrace (PTRACE_KILL, second_pid, 0, 0); | |
476 | if (ret != 0) | |
3e43a32a MS |
477 | warning (_("linux_test_for_tracefork: " |
478 | "failed to kill second child")); | |
97725dc4 | 479 | my_waitpid (second_pid, &status, 0); |
3993f6b1 DJ |
480 | } |
481 | } | |
b957e937 | 482 | else |
8a3fe4f8 AC |
483 | warning (_("linux_test_for_tracefork: unexpected result from waitpid " |
484 | "(%d, status 0x%x)"), ret, status); | |
3993f6b1 | 485 | |
b957e937 DJ |
486 | ret = ptrace (PTRACE_KILL, child_pid, 0, 0); |
487 | if (ret != 0) | |
8a3fe4f8 | 488 | warning (_("linux_test_for_tracefork: failed to kill child")); |
b957e937 | 489 | my_waitpid (child_pid, &status, 0); |
4c28f408 | 490 | |
7feb7d06 | 491 | restore_child_signals_mask (&prev_mask); |
3993f6b1 DJ |
492 | } |
493 | ||
a96d9b2e SDJ |
494 | /* Determine if PTRACE_O_TRACESYSGOOD can be used to follow syscalls. |
495 | ||
496 | We try to enable syscall tracing on ORIGINAL_PID. If this fails, | |
497 | we know that the feature is not available. This may change the tracing | |
498 | options for ORIGINAL_PID, but we'll be setting them shortly anyway. */ | |
499 | ||
500 | static void | |
501 | linux_test_for_tracesysgood (int original_pid) | |
502 | { | |
503 | int ret; | |
504 | sigset_t prev_mask; | |
505 | ||
506 | /* We don't want those ptrace calls to be interrupted. */ | |
507 | block_child_signals (&prev_mask); | |
508 | ||
509 | linux_supports_tracesysgood_flag = 0; | |
510 | ||
511 | ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACESYSGOOD); | |
512 | if (ret != 0) | |
513 | goto out; | |
514 | ||
515 | linux_supports_tracesysgood_flag = 1; | |
516 | out: | |
517 | restore_child_signals_mask (&prev_mask); | |
518 | } | |
519 | ||
520 | /* Determine wether we support PTRACE_O_TRACESYSGOOD option available. | |
521 | This function also sets linux_supports_tracesysgood_flag. */ | |
522 | ||
523 | static int | |
524 | linux_supports_tracesysgood (int pid) | |
525 | { | |
526 | if (linux_supports_tracesysgood_flag == -1) | |
527 | linux_test_for_tracesysgood (pid); | |
528 | return linux_supports_tracesysgood_flag; | |
529 | } | |
530 | ||
3993f6b1 DJ |
531 | /* Return non-zero iff we have tracefork functionality available. |
532 | This function also sets linux_supports_tracefork_flag. */ | |
533 | ||
534 | static int | |
b957e937 | 535 | linux_supports_tracefork (int pid) |
3993f6b1 DJ |
536 | { |
537 | if (linux_supports_tracefork_flag == -1) | |
b957e937 | 538 | linux_test_for_tracefork (pid); |
3993f6b1 DJ |
539 | return linux_supports_tracefork_flag; |
540 | } | |
541 | ||
9016a515 | 542 | static int |
b957e937 | 543 | linux_supports_tracevforkdone (int pid) |
9016a515 DJ |
544 | { |
545 | if (linux_supports_tracefork_flag == -1) | |
b957e937 | 546 | linux_test_for_tracefork (pid); |
9016a515 DJ |
547 | return linux_supports_tracevforkdone_flag; |
548 | } | |
549 | ||
a96d9b2e SDJ |
550 | static void |
551 | linux_enable_tracesysgood (ptid_t ptid) | |
552 | { | |
553 | int pid = ptid_get_lwp (ptid); | |
554 | ||
555 | if (pid == 0) | |
556 | pid = ptid_get_pid (ptid); | |
557 | ||
558 | if (linux_supports_tracesysgood (pid) == 0) | |
559 | return; | |
560 | ||
561 | current_ptrace_options |= PTRACE_O_TRACESYSGOOD; | |
562 | ||
563 | ptrace (PTRACE_SETOPTIONS, pid, 0, current_ptrace_options); | |
564 | } | |
565 | ||
3993f6b1 | 566 | \f |
4de4c07c DJ |
567 | void |
568 | linux_enable_event_reporting (ptid_t ptid) | |
569 | { | |
d3587048 | 570 | int pid = ptid_get_lwp (ptid); |
4de4c07c | 571 | |
d3587048 DJ |
572 | if (pid == 0) |
573 | pid = ptid_get_pid (ptid); | |
574 | ||
b957e937 | 575 | if (! linux_supports_tracefork (pid)) |
4de4c07c DJ |
576 | return; |
577 | ||
a96d9b2e SDJ |
578 | current_ptrace_options |= PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK |
579 | | PTRACE_O_TRACEEXEC | PTRACE_O_TRACECLONE; | |
580 | ||
b957e937 | 581 | if (linux_supports_tracevforkdone (pid)) |
a96d9b2e | 582 | current_ptrace_options |= PTRACE_O_TRACEVFORKDONE; |
9016a515 DJ |
583 | |
584 | /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support | |
585 | read-only process state. */ | |
4de4c07c | 586 | |
a96d9b2e | 587 | ptrace (PTRACE_SETOPTIONS, pid, 0, current_ptrace_options); |
4de4c07c DJ |
588 | } |
589 | ||
6d8fd2b7 UW |
590 | static void |
591 | linux_child_post_attach (int pid) | |
4de4c07c DJ |
592 | { |
593 | linux_enable_event_reporting (pid_to_ptid (pid)); | |
a96d9b2e | 594 | linux_enable_tracesysgood (pid_to_ptid (pid)); |
aa7c7447 | 595 | linux_ptrace_init_warnings (); |
4de4c07c DJ |
596 | } |
597 | ||
10d6c8cd | 598 | static void |
4de4c07c DJ |
599 | linux_child_post_startup_inferior (ptid_t ptid) |
600 | { | |
601 | linux_enable_event_reporting (ptid); | |
a96d9b2e | 602 | linux_enable_tracesysgood (ptid); |
aa7c7447 | 603 | linux_ptrace_init_warnings (); |
4de4c07c DJ |
604 | } |
605 | ||
4403d8e9 JK |
606 | /* Return the number of known LWPs in the tgid given by PID. */ |
607 | ||
608 | static int | |
609 | num_lwps (int pid) | |
610 | { | |
611 | int count = 0; | |
612 | struct lwp_info *lp; | |
613 | ||
614 | for (lp = lwp_list; lp; lp = lp->next) | |
615 | if (ptid_get_pid (lp->ptid) == pid) | |
616 | count++; | |
617 | ||
618 | return count; | |
619 | } | |
620 | ||
621 | /* Call delete_lwp with prototype compatible for make_cleanup. */ | |
622 | ||
623 | static void | |
624 | delete_lwp_cleanup (void *lp_voidp) | |
625 | { | |
626 | struct lwp_info *lp = lp_voidp; | |
627 | ||
628 | delete_lwp (lp->ptid); | |
629 | } | |
630 | ||
6d8fd2b7 UW |
631 | static int |
632 | linux_child_follow_fork (struct target_ops *ops, int follow_child) | |
3993f6b1 | 633 | { |
7feb7d06 | 634 | sigset_t prev_mask; |
9016a515 | 635 | int has_vforked; |
4de4c07c DJ |
636 | int parent_pid, child_pid; |
637 | ||
7feb7d06 | 638 | block_child_signals (&prev_mask); |
b84876c2 | 639 | |
e58b0e63 PA |
640 | has_vforked = (inferior_thread ()->pending_follow.kind |
641 | == TARGET_WAITKIND_VFORKED); | |
642 | parent_pid = ptid_get_lwp (inferior_ptid); | |
d3587048 | 643 | if (parent_pid == 0) |
e58b0e63 PA |
644 | parent_pid = ptid_get_pid (inferior_ptid); |
645 | child_pid = PIDGET (inferior_thread ()->pending_follow.value.related_pid); | |
4de4c07c | 646 | |
6c95b8df PA |
647 | if (has_vforked |
648 | && !non_stop /* Non-stop always resumes both branches. */ | |
649 | && (!target_is_async_p () || sync_execution) | |
650 | && !(follow_child || detach_fork || sched_multi)) | |
651 | { | |
652 | /* The parent stays blocked inside the vfork syscall until the | |
653 | child execs or exits. If we don't let the child run, then | |
654 | the parent stays blocked. If we're telling the parent to run | |
655 | in the foreground, the user will not be able to ctrl-c to get | |
656 | back the terminal, effectively hanging the debug session. */ | |
ac74f770 MS |
657 | fprintf_filtered (gdb_stderr, _("\ |
658 | Can not resume the parent process over vfork in the foreground while\n\ | |
659 | holding the child stopped. Try \"set detach-on-fork\" or \ | |
660 | \"set schedule-multiple\".\n")); | |
661 | /* FIXME output string > 80 columns. */ | |
6c95b8df PA |
662 | return 1; |
663 | } | |
664 | ||
4de4c07c DJ |
665 | if (! follow_child) |
666 | { | |
6c95b8df | 667 | struct lwp_info *child_lp = NULL; |
4de4c07c | 668 | |
1777feb0 | 669 | /* We're already attached to the parent, by default. */ |
4de4c07c | 670 | |
ac264b3b MS |
671 | /* Detach new forked process? */ |
672 | if (detach_fork) | |
f75c00e4 | 673 | { |
4403d8e9 JK |
674 | struct cleanup *old_chain; |
675 | ||
6c95b8df PA |
676 | /* Before detaching from the child, remove all breakpoints |
677 | from it. If we forked, then this has already been taken | |
678 | care of by infrun.c. If we vforked however, any | |
679 | breakpoint inserted in the parent is visible in the | |
680 | child, even those added while stopped in a vfork | |
681 | catchpoint. This will remove the breakpoints from the | |
682 | parent also, but they'll be reinserted below. */ | |
683 | if (has_vforked) | |
684 | { | |
685 | /* keep breakpoints list in sync. */ | |
686 | remove_breakpoints_pid (GET_PID (inferior_ptid)); | |
687 | } | |
688 | ||
e85a822c | 689 | if (info_verbose || debug_linux_nat) |
ac264b3b MS |
690 | { |
691 | target_terminal_ours (); | |
692 | fprintf_filtered (gdb_stdlog, | |
3e43a32a MS |
693 | "Detaching after fork from " |
694 | "child process %d.\n", | |
ac264b3b MS |
695 | child_pid); |
696 | } | |
4de4c07c | 697 | |
4403d8e9 JK |
698 | old_chain = save_inferior_ptid (); |
699 | inferior_ptid = ptid_build (child_pid, child_pid, 0); | |
700 | ||
701 | child_lp = add_lwp (inferior_ptid); | |
702 | child_lp->stopped = 1; | |
703 | child_lp->last_resume_kind = resume_stop; | |
704 | make_cleanup (delete_lwp_cleanup, child_lp); | |
705 | ||
4403d8e9 JK |
706 | if (linux_nat_prepare_to_resume != NULL) |
707 | linux_nat_prepare_to_resume (child_lp); | |
ac264b3b | 708 | ptrace (PTRACE_DETACH, child_pid, 0, 0); |
4403d8e9 JK |
709 | |
710 | do_cleanups (old_chain); | |
ac264b3b MS |
711 | } |
712 | else | |
713 | { | |
77435e4c | 714 | struct inferior *parent_inf, *child_inf; |
2277426b | 715 | struct cleanup *old_chain; |
7f9f62ba PA |
716 | |
717 | /* Add process to GDB's tables. */ | |
77435e4c PA |
718 | child_inf = add_inferior (child_pid); |
719 | ||
e58b0e63 | 720 | parent_inf = current_inferior (); |
77435e4c | 721 | child_inf->attach_flag = parent_inf->attach_flag; |
191c4426 | 722 | copy_terminal_info (child_inf, parent_inf); |
6ecd4729 PA |
723 | child_inf->gdbarch = parent_inf->gdbarch; |
724 | copy_inferior_target_desc_info (child_inf, parent_inf); | |
7f9f62ba | 725 | |
2277426b | 726 | old_chain = save_inferior_ptid (); |
6c95b8df | 727 | save_current_program_space (); |
2277426b PA |
728 | |
729 | inferior_ptid = ptid_build (child_pid, child_pid, 0); | |
730 | add_thread (inferior_ptid); | |
6c95b8df PA |
731 | child_lp = add_lwp (inferior_ptid); |
732 | child_lp->stopped = 1; | |
25289eb2 | 733 | child_lp->last_resume_kind = resume_stop; |
7dcd53a0 | 734 | child_inf->symfile_flags = SYMFILE_NO_READ; |
2277426b | 735 | |
6c95b8df PA |
736 | /* If this is a vfork child, then the address-space is |
737 | shared with the parent. */ | |
738 | if (has_vforked) | |
739 | { | |
740 | child_inf->pspace = parent_inf->pspace; | |
741 | child_inf->aspace = parent_inf->aspace; | |
742 | ||
743 | /* The parent will be frozen until the child is done | |
744 | with the shared region. Keep track of the | |
745 | parent. */ | |
746 | child_inf->vfork_parent = parent_inf; | |
747 | child_inf->pending_detach = 0; | |
748 | parent_inf->vfork_child = child_inf; | |
749 | parent_inf->pending_detach = 0; | |
750 | } | |
751 | else | |
752 | { | |
753 | child_inf->aspace = new_address_space (); | |
754 | child_inf->pspace = add_program_space (child_inf->aspace); | |
755 | child_inf->removable = 1; | |
756 | set_current_program_space (child_inf->pspace); | |
757 | clone_program_space (child_inf->pspace, parent_inf->pspace); | |
758 | ||
759 | /* Let the shared library layer (solib-svr4) learn about | |
760 | this new process, relocate the cloned exec, pull in | |
761 | shared libraries, and install the solib event | |
762 | breakpoint. If a "cloned-VM" event was propagated | |
763 | better throughout the core, this wouldn't be | |
764 | required. */ | |
268a4a75 | 765 | solib_create_inferior_hook (0); |
6c95b8df PA |
766 | } |
767 | ||
768 | /* Let the thread_db layer learn about this new process. */ | |
2277426b PA |
769 | check_for_thread_db (); |
770 | ||
771 | do_cleanups (old_chain); | |
ac264b3b | 772 | } |
9016a515 DJ |
773 | |
774 | if (has_vforked) | |
775 | { | |
3ced3da4 | 776 | struct lwp_info *parent_lp; |
6c95b8df PA |
777 | struct inferior *parent_inf; |
778 | ||
779 | parent_inf = current_inferior (); | |
780 | ||
781 | /* If we detached from the child, then we have to be careful | |
782 | to not insert breakpoints in the parent until the child | |
783 | is done with the shared memory region. However, if we're | |
784 | staying attached to the child, then we can and should | |
785 | insert breakpoints, so that we can debug it. A | |
786 | subsequent child exec or exit is enough to know when does | |
787 | the child stops using the parent's address space. */ | |
788 | parent_inf->waiting_for_vfork_done = detach_fork; | |
56710373 | 789 | parent_inf->pspace->breakpoints_not_allowed = detach_fork; |
6c95b8df | 790 | |
3ced3da4 | 791 | parent_lp = find_lwp_pid (pid_to_ptid (parent_pid)); |
b957e937 | 792 | gdb_assert (linux_supports_tracefork_flag >= 0); |
3ced3da4 | 793 | |
b957e937 | 794 | if (linux_supports_tracevforkdone (0)) |
9016a515 | 795 | { |
6c95b8df PA |
796 | if (debug_linux_nat) |
797 | fprintf_unfiltered (gdb_stdlog, | |
798 | "LCFF: waiting for VFORK_DONE on %d\n", | |
799 | parent_pid); | |
3ced3da4 | 800 | parent_lp->stopped = 1; |
9016a515 | 801 | |
6c95b8df PA |
802 | /* We'll handle the VFORK_DONE event like any other |
803 | event, in target_wait. */ | |
9016a515 DJ |
804 | } |
805 | else | |
806 | { | |
807 | /* We can't insert breakpoints until the child has | |
808 | finished with the shared memory region. We need to | |
809 | wait until that happens. Ideal would be to just | |
810 | call: | |
811 | - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0); | |
812 | - waitpid (parent_pid, &status, __WALL); | |
813 | However, most architectures can't handle a syscall | |
814 | being traced on the way out if it wasn't traced on | |
815 | the way in. | |
816 | ||
817 | We might also think to loop, continuing the child | |
818 | until it exits or gets a SIGTRAP. One problem is | |
819 | that the child might call ptrace with PTRACE_TRACEME. | |
820 | ||
821 | There's no simple and reliable way to figure out when | |
822 | the vforked child will be done with its copy of the | |
823 | shared memory. We could step it out of the syscall, | |
824 | two instructions, let it go, and then single-step the | |
825 | parent once. When we have hardware single-step, this | |
826 | would work; with software single-step it could still | |
827 | be made to work but we'd have to be able to insert | |
828 | single-step breakpoints in the child, and we'd have | |
829 | to insert -just- the single-step breakpoint in the | |
830 | parent. Very awkward. | |
831 | ||
832 | In the end, the best we can do is to make sure it | |
833 | runs for a little while. Hopefully it will be out of | |
834 | range of any breakpoints we reinsert. Usually this | |
835 | is only the single-step breakpoint at vfork's return | |
836 | point. */ | |
837 | ||
6c95b8df PA |
838 | if (debug_linux_nat) |
839 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
840 | "LCFF: no VFORK_DONE " |
841 | "support, sleeping a bit\n"); | |
6c95b8df | 842 | |
9016a515 | 843 | usleep (10000); |
9016a515 | 844 | |
6c95b8df PA |
845 | /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event, |
846 | and leave it pending. The next linux_nat_resume call | |
847 | will notice a pending event, and bypasses actually | |
848 | resuming the inferior. */ | |
3ced3da4 PA |
849 | parent_lp->status = 0; |
850 | parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE; | |
851 | parent_lp->stopped = 1; | |
6c95b8df PA |
852 | |
853 | /* If we're in async mode, need to tell the event loop | |
854 | there's something here to process. */ | |
855 | if (target_can_async_p ()) | |
856 | async_file_mark (); | |
857 | } | |
9016a515 | 858 | } |
4de4c07c | 859 | } |
3993f6b1 | 860 | else |
4de4c07c | 861 | { |
77435e4c | 862 | struct inferior *parent_inf, *child_inf; |
3ced3da4 | 863 | struct lwp_info *child_lp; |
6c95b8df | 864 | struct program_space *parent_pspace; |
4de4c07c | 865 | |
e85a822c | 866 | if (info_verbose || debug_linux_nat) |
f75c00e4 DJ |
867 | { |
868 | target_terminal_ours (); | |
6c95b8df | 869 | if (has_vforked) |
3e43a32a MS |
870 | fprintf_filtered (gdb_stdlog, |
871 | _("Attaching after process %d " | |
872 | "vfork to child process %d.\n"), | |
6c95b8df PA |
873 | parent_pid, child_pid); |
874 | else | |
3e43a32a MS |
875 | fprintf_filtered (gdb_stdlog, |
876 | _("Attaching after process %d " | |
877 | "fork to child process %d.\n"), | |
6c95b8df | 878 | parent_pid, child_pid); |
f75c00e4 | 879 | } |
4de4c07c | 880 | |
7a7d3353 PA |
881 | /* Add the new inferior first, so that the target_detach below |
882 | doesn't unpush the target. */ | |
883 | ||
77435e4c PA |
884 | child_inf = add_inferior (child_pid); |
885 | ||
e58b0e63 | 886 | parent_inf = current_inferior (); |
77435e4c | 887 | child_inf->attach_flag = parent_inf->attach_flag; |
191c4426 | 888 | copy_terminal_info (child_inf, parent_inf); |
6ecd4729 PA |
889 | child_inf->gdbarch = parent_inf->gdbarch; |
890 | copy_inferior_target_desc_info (child_inf, parent_inf); | |
7a7d3353 | 891 | |
6c95b8df | 892 | parent_pspace = parent_inf->pspace; |
9016a515 | 893 | |
6c95b8df PA |
894 | /* If we're vforking, we want to hold on to the parent until the |
895 | child exits or execs. At child exec or exit time we can | |
896 | remove the old breakpoints from the parent and detach or | |
897 | resume debugging it. Otherwise, detach the parent now; we'll | |
898 | want to reuse it's program/address spaces, but we can't set | |
899 | them to the child before removing breakpoints from the | |
900 | parent, otherwise, the breakpoints module could decide to | |
901 | remove breakpoints from the wrong process (since they'd be | |
902 | assigned to the same address space). */ | |
9016a515 DJ |
903 | |
904 | if (has_vforked) | |
7f9f62ba | 905 | { |
6c95b8df PA |
906 | gdb_assert (child_inf->vfork_parent == NULL); |
907 | gdb_assert (parent_inf->vfork_child == NULL); | |
908 | child_inf->vfork_parent = parent_inf; | |
909 | child_inf->pending_detach = 0; | |
910 | parent_inf->vfork_child = child_inf; | |
911 | parent_inf->pending_detach = detach_fork; | |
912 | parent_inf->waiting_for_vfork_done = 0; | |
ac264b3b | 913 | } |
2277426b | 914 | else if (detach_fork) |
b84876c2 | 915 | target_detach (NULL, 0); |
4de4c07c | 916 | |
6c95b8df PA |
917 | /* Note that the detach above makes PARENT_INF dangling. */ |
918 | ||
919 | /* Add the child thread to the appropriate lists, and switch to | |
920 | this new thread, before cloning the program space, and | |
921 | informing the solib layer about this new process. */ | |
922 | ||
9f0bdab8 | 923 | inferior_ptid = ptid_build (child_pid, child_pid, 0); |
2277426b | 924 | add_thread (inferior_ptid); |
3ced3da4 PA |
925 | child_lp = add_lwp (inferior_ptid); |
926 | child_lp->stopped = 1; | |
25289eb2 | 927 | child_lp->last_resume_kind = resume_stop; |
6c95b8df PA |
928 | |
929 | /* If this is a vfork child, then the address-space is shared | |
930 | with the parent. If we detached from the parent, then we can | |
931 | reuse the parent's program/address spaces. */ | |
932 | if (has_vforked || detach_fork) | |
933 | { | |
934 | child_inf->pspace = parent_pspace; | |
935 | child_inf->aspace = child_inf->pspace->aspace; | |
936 | } | |
937 | else | |
938 | { | |
939 | child_inf->aspace = new_address_space (); | |
940 | child_inf->pspace = add_program_space (child_inf->aspace); | |
941 | child_inf->removable = 1; | |
7dcd53a0 | 942 | child_inf->symfile_flags = SYMFILE_NO_READ; |
6c95b8df PA |
943 | set_current_program_space (child_inf->pspace); |
944 | clone_program_space (child_inf->pspace, parent_pspace); | |
945 | ||
946 | /* Let the shared library layer (solib-svr4) learn about | |
947 | this new process, relocate the cloned exec, pull in | |
948 | shared libraries, and install the solib event breakpoint. | |
949 | If a "cloned-VM" event was propagated better throughout | |
950 | the core, this wouldn't be required. */ | |
268a4a75 | 951 | solib_create_inferior_hook (0); |
6c95b8df | 952 | } |
ac264b3b | 953 | |
6c95b8df | 954 | /* Let the thread_db layer learn about this new process. */ |
ef29ce1a | 955 | check_for_thread_db (); |
4de4c07c DJ |
956 | } |
957 | ||
7feb7d06 | 958 | restore_child_signals_mask (&prev_mask); |
4de4c07c DJ |
959 | return 0; |
960 | } | |
961 | ||
4de4c07c | 962 | \f |
77b06cd7 | 963 | static int |
6d8fd2b7 | 964 | linux_child_insert_fork_catchpoint (int pid) |
4de4c07c | 965 | { |
77b06cd7 | 966 | return !linux_supports_tracefork (pid); |
3993f6b1 DJ |
967 | } |
968 | ||
eb73ad13 PA |
969 | static int |
970 | linux_child_remove_fork_catchpoint (int pid) | |
971 | { | |
972 | return 0; | |
973 | } | |
974 | ||
77b06cd7 | 975 | static int |
6d8fd2b7 | 976 | linux_child_insert_vfork_catchpoint (int pid) |
3993f6b1 | 977 | { |
77b06cd7 | 978 | return !linux_supports_tracefork (pid); |
3993f6b1 DJ |
979 | } |
980 | ||
eb73ad13 PA |
981 | static int |
982 | linux_child_remove_vfork_catchpoint (int pid) | |
983 | { | |
984 | return 0; | |
985 | } | |
986 | ||
77b06cd7 | 987 | static int |
6d8fd2b7 | 988 | linux_child_insert_exec_catchpoint (int pid) |
3993f6b1 | 989 | { |
77b06cd7 | 990 | return !linux_supports_tracefork (pid); |
3993f6b1 DJ |
991 | } |
992 | ||
eb73ad13 PA |
993 | static int |
994 | linux_child_remove_exec_catchpoint (int pid) | |
995 | { | |
996 | return 0; | |
997 | } | |
998 | ||
a96d9b2e SDJ |
999 | static int |
1000 | linux_child_set_syscall_catchpoint (int pid, int needed, int any_count, | |
1001 | int table_size, int *table) | |
1002 | { | |
77b06cd7 TJB |
1003 | if (!linux_supports_tracesysgood (pid)) |
1004 | return 1; | |
1005 | ||
a96d9b2e SDJ |
1006 | /* On GNU/Linux, we ignore the arguments. It means that we only |
1007 | enable the syscall catchpoints, but do not disable them. | |
77b06cd7 | 1008 | |
a96d9b2e SDJ |
1009 | Also, we do not use the `table' information because we do not |
1010 | filter system calls here. We let GDB do the logic for us. */ | |
1011 | return 0; | |
1012 | } | |
1013 | ||
d6b0e80f AC |
1014 | /* On GNU/Linux there are no real LWP's. The closest thing to LWP's |
1015 | are processes sharing the same VM space. A multi-threaded process | |
1016 | is basically a group of such processes. However, such a grouping | |
1017 | is almost entirely a user-space issue; the kernel doesn't enforce | |
1018 | such a grouping at all (this might change in the future). In | |
1019 | general, we'll rely on the threads library (i.e. the GNU/Linux | |
1020 | Threads library) to provide such a grouping. | |
1021 | ||
1022 | It is perfectly well possible to write a multi-threaded application | |
1023 | without the assistance of a threads library, by using the clone | |
1024 | system call directly. This module should be able to give some | |
1025 | rudimentary support for debugging such applications if developers | |
1026 | specify the CLONE_PTRACE flag in the clone system call, and are | |
1027 | using the Linux kernel 2.4 or above. | |
1028 | ||
1029 | Note that there are some peculiarities in GNU/Linux that affect | |
1030 | this code: | |
1031 | ||
1032 | - In general one should specify the __WCLONE flag to waitpid in | |
1033 | order to make it report events for any of the cloned processes | |
1034 | (and leave it out for the initial process). However, if a cloned | |
1035 | process has exited the exit status is only reported if the | |
1036 | __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but | |
1037 | we cannot use it since GDB must work on older systems too. | |
1038 | ||
1039 | - When a traced, cloned process exits and is waited for by the | |
1040 | debugger, the kernel reassigns it to the original parent and | |
1041 | keeps it around as a "zombie". Somehow, the GNU/Linux Threads | |
1042 | library doesn't notice this, which leads to the "zombie problem": | |
1043 | When debugged a multi-threaded process that spawns a lot of | |
1044 | threads will run out of processes, even if the threads exit, | |
1045 | because the "zombies" stay around. */ | |
1046 | ||
1047 | /* List of known LWPs. */ | |
9f0bdab8 | 1048 | struct lwp_info *lwp_list; |
d6b0e80f AC |
1049 | \f |
1050 | ||
d6b0e80f AC |
1051 | /* Original signal mask. */ |
1052 | static sigset_t normal_mask; | |
1053 | ||
1054 | /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in | |
1055 | _initialize_linux_nat. */ | |
1056 | static sigset_t suspend_mask; | |
1057 | ||
7feb7d06 PA |
1058 | /* Signals to block to make that sigsuspend work. */ |
1059 | static sigset_t blocked_mask; | |
1060 | ||
1061 | /* SIGCHLD action. */ | |
1062 | struct sigaction sigchld_action; | |
b84876c2 | 1063 | |
7feb7d06 PA |
1064 | /* Block child signals (SIGCHLD and linux threads signals), and store |
1065 | the previous mask in PREV_MASK. */ | |
84e46146 | 1066 | |
7feb7d06 PA |
1067 | static void |
1068 | block_child_signals (sigset_t *prev_mask) | |
1069 | { | |
1070 | /* Make sure SIGCHLD is blocked. */ | |
1071 | if (!sigismember (&blocked_mask, SIGCHLD)) | |
1072 | sigaddset (&blocked_mask, SIGCHLD); | |
1073 | ||
1074 | sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask); | |
1075 | } | |
1076 | ||
1077 | /* Restore child signals mask, previously returned by | |
1078 | block_child_signals. */ | |
1079 | ||
1080 | static void | |
1081 | restore_child_signals_mask (sigset_t *prev_mask) | |
1082 | { | |
1083 | sigprocmask (SIG_SETMASK, prev_mask, NULL); | |
1084 | } | |
2455069d UW |
1085 | |
1086 | /* Mask of signals to pass directly to the inferior. */ | |
1087 | static sigset_t pass_mask; | |
1088 | ||
1089 | /* Update signals to pass to the inferior. */ | |
1090 | static void | |
1091 | linux_nat_pass_signals (int numsigs, unsigned char *pass_signals) | |
1092 | { | |
1093 | int signo; | |
1094 | ||
1095 | sigemptyset (&pass_mask); | |
1096 | ||
1097 | for (signo = 1; signo < NSIG; signo++) | |
1098 | { | |
2ea28649 | 1099 | int target_signo = gdb_signal_from_host (signo); |
2455069d UW |
1100 | if (target_signo < numsigs && pass_signals[target_signo]) |
1101 | sigaddset (&pass_mask, signo); | |
1102 | } | |
1103 | } | |
1104 | ||
d6b0e80f AC |
1105 | \f |
1106 | ||
1107 | /* Prototypes for local functions. */ | |
1108 | static int stop_wait_callback (struct lwp_info *lp, void *data); | |
28439f5e | 1109 | static int linux_thread_alive (ptid_t ptid); |
6d8fd2b7 | 1110 | static char *linux_child_pid_to_exec_file (int pid); |
710151dd | 1111 | |
d6b0e80f AC |
1112 | \f |
1113 | /* Convert wait status STATUS to a string. Used for printing debug | |
1114 | messages only. */ | |
1115 | ||
1116 | static char * | |
1117 | status_to_str (int status) | |
1118 | { | |
1119 | static char buf[64]; | |
1120 | ||
1121 | if (WIFSTOPPED (status)) | |
206aa767 | 1122 | { |
ca2163eb | 1123 | if (WSTOPSIG (status) == SYSCALL_SIGTRAP) |
206aa767 DE |
1124 | snprintf (buf, sizeof (buf), "%s (stopped at syscall)", |
1125 | strsignal (SIGTRAP)); | |
1126 | else | |
1127 | snprintf (buf, sizeof (buf), "%s (stopped)", | |
1128 | strsignal (WSTOPSIG (status))); | |
1129 | } | |
d6b0e80f AC |
1130 | else if (WIFSIGNALED (status)) |
1131 | snprintf (buf, sizeof (buf), "%s (terminated)", | |
ba9b2ec3 | 1132 | strsignal (WTERMSIG (status))); |
d6b0e80f AC |
1133 | else |
1134 | snprintf (buf, sizeof (buf), "%d (exited)", WEXITSTATUS (status)); | |
1135 | ||
1136 | return buf; | |
1137 | } | |
1138 | ||
7b50312a PA |
1139 | /* Destroy and free LP. */ |
1140 | ||
1141 | static void | |
1142 | lwp_free (struct lwp_info *lp) | |
1143 | { | |
1144 | xfree (lp->arch_private); | |
1145 | xfree (lp); | |
1146 | } | |
1147 | ||
d90e17a7 PA |
1148 | /* Remove all LWPs belong to PID from the lwp list. */ |
1149 | ||
1150 | static void | |
1151 | purge_lwp_list (int pid) | |
1152 | { | |
1153 | struct lwp_info *lp, *lpprev, *lpnext; | |
1154 | ||
1155 | lpprev = NULL; | |
1156 | ||
1157 | for (lp = lwp_list; lp; lp = lpnext) | |
1158 | { | |
1159 | lpnext = lp->next; | |
1160 | ||
1161 | if (ptid_get_pid (lp->ptid) == pid) | |
1162 | { | |
1163 | if (lp == lwp_list) | |
1164 | lwp_list = lp->next; | |
1165 | else | |
1166 | lpprev->next = lp->next; | |
1167 | ||
7b50312a | 1168 | lwp_free (lp); |
d90e17a7 PA |
1169 | } |
1170 | else | |
1171 | lpprev = lp; | |
1172 | } | |
1173 | } | |
1174 | ||
26cb8b7c PA |
1175 | /* Add the LWP specified by PTID to the list. PTID is the first LWP |
1176 | in the process. Return a pointer to the structure describing the | |
1177 | new LWP. | |
1178 | ||
1179 | This differs from add_lwp in that we don't let the arch specific | |
1180 | bits know about this new thread. Current clients of this callback | |
1181 | take the opportunity to install watchpoints in the new thread, and | |
1182 | we shouldn't do that for the first thread. If we're spawning a | |
1183 | child ("run"), the thread executes the shell wrapper first, and we | |
1184 | shouldn't touch it until it execs the program we want to debug. | |
1185 | For "attach", it'd be okay to call the callback, but it's not | |
1186 | necessary, because watchpoints can't yet have been inserted into | |
1187 | the inferior. */ | |
d6b0e80f AC |
1188 | |
1189 | static struct lwp_info * | |
26cb8b7c | 1190 | add_initial_lwp (ptid_t ptid) |
d6b0e80f AC |
1191 | { |
1192 | struct lwp_info *lp; | |
1193 | ||
1194 | gdb_assert (is_lwp (ptid)); | |
1195 | ||
1196 | lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info)); | |
1197 | ||
1198 | memset (lp, 0, sizeof (struct lwp_info)); | |
1199 | ||
25289eb2 | 1200 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1201 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
1202 | ||
1203 | lp->ptid = ptid; | |
dc146f7c | 1204 | lp->core = -1; |
d6b0e80f AC |
1205 | |
1206 | lp->next = lwp_list; | |
1207 | lwp_list = lp; | |
d6b0e80f | 1208 | |
26cb8b7c PA |
1209 | return lp; |
1210 | } | |
1211 | ||
1212 | /* Add the LWP specified by PID to the list. Return a pointer to the | |
1213 | structure describing the new LWP. The LWP should already be | |
1214 | stopped. */ | |
1215 | ||
1216 | static struct lwp_info * | |
1217 | add_lwp (ptid_t ptid) | |
1218 | { | |
1219 | struct lwp_info *lp; | |
1220 | ||
1221 | lp = add_initial_lwp (ptid); | |
1222 | ||
6e012a6c PA |
1223 | /* Let the arch specific bits know about this new thread. Current |
1224 | clients of this callback take the opportunity to install | |
26cb8b7c PA |
1225 | watchpoints in the new thread. We don't do this for the first |
1226 | thread though. See add_initial_lwp. */ | |
1227 | if (linux_nat_new_thread != NULL) | |
7b50312a | 1228 | linux_nat_new_thread (lp); |
9f0bdab8 | 1229 | |
d6b0e80f AC |
1230 | return lp; |
1231 | } | |
1232 | ||
1233 | /* Remove the LWP specified by PID from the list. */ | |
1234 | ||
1235 | static void | |
1236 | delete_lwp (ptid_t ptid) | |
1237 | { | |
1238 | struct lwp_info *lp, *lpprev; | |
1239 | ||
1240 | lpprev = NULL; | |
1241 | ||
1242 | for (lp = lwp_list; lp; lpprev = lp, lp = lp->next) | |
1243 | if (ptid_equal (lp->ptid, ptid)) | |
1244 | break; | |
1245 | ||
1246 | if (!lp) | |
1247 | return; | |
1248 | ||
d6b0e80f AC |
1249 | if (lpprev) |
1250 | lpprev->next = lp->next; | |
1251 | else | |
1252 | lwp_list = lp->next; | |
1253 | ||
7b50312a | 1254 | lwp_free (lp); |
d6b0e80f AC |
1255 | } |
1256 | ||
1257 | /* Return a pointer to the structure describing the LWP corresponding | |
1258 | to PID. If no corresponding LWP could be found, return NULL. */ | |
1259 | ||
1260 | static struct lwp_info * | |
1261 | find_lwp_pid (ptid_t ptid) | |
1262 | { | |
1263 | struct lwp_info *lp; | |
1264 | int lwp; | |
1265 | ||
1266 | if (is_lwp (ptid)) | |
1267 | lwp = GET_LWP (ptid); | |
1268 | else | |
1269 | lwp = GET_PID (ptid); | |
1270 | ||
1271 | for (lp = lwp_list; lp; lp = lp->next) | |
1272 | if (lwp == GET_LWP (lp->ptid)) | |
1273 | return lp; | |
1274 | ||
1275 | return NULL; | |
1276 | } | |
1277 | ||
1278 | /* Call CALLBACK with its second argument set to DATA for every LWP in | |
1279 | the list. If CALLBACK returns 1 for a particular LWP, return a | |
1280 | pointer to the structure describing that LWP immediately. | |
1281 | Otherwise return NULL. */ | |
1282 | ||
1283 | struct lwp_info * | |
d90e17a7 PA |
1284 | iterate_over_lwps (ptid_t filter, |
1285 | int (*callback) (struct lwp_info *, void *), | |
1286 | void *data) | |
d6b0e80f AC |
1287 | { |
1288 | struct lwp_info *lp, *lpnext; | |
1289 | ||
1290 | for (lp = lwp_list; lp; lp = lpnext) | |
1291 | { | |
1292 | lpnext = lp->next; | |
d90e17a7 PA |
1293 | |
1294 | if (ptid_match (lp->ptid, filter)) | |
1295 | { | |
1296 | if ((*callback) (lp, data)) | |
1297 | return lp; | |
1298 | } | |
d6b0e80f AC |
1299 | } |
1300 | ||
1301 | return NULL; | |
1302 | } | |
1303 | ||
2277426b PA |
1304 | /* Update our internal state when changing from one checkpoint to |
1305 | another indicated by NEW_PTID. We can only switch single-threaded | |
1306 | applications, so we only create one new LWP, and the previous list | |
1307 | is discarded. */ | |
f973ed9c DJ |
1308 | |
1309 | void | |
1310 | linux_nat_switch_fork (ptid_t new_ptid) | |
1311 | { | |
1312 | struct lwp_info *lp; | |
1313 | ||
2277426b PA |
1314 | purge_lwp_list (GET_PID (inferior_ptid)); |
1315 | ||
f973ed9c DJ |
1316 | lp = add_lwp (new_ptid); |
1317 | lp->stopped = 1; | |
e26af52f | 1318 | |
2277426b PA |
1319 | /* This changes the thread's ptid while preserving the gdb thread |
1320 | num. Also changes the inferior pid, while preserving the | |
1321 | inferior num. */ | |
1322 | thread_change_ptid (inferior_ptid, new_ptid); | |
1323 | ||
1324 | /* We've just told GDB core that the thread changed target id, but, | |
1325 | in fact, it really is a different thread, with different register | |
1326 | contents. */ | |
1327 | registers_changed (); | |
e26af52f DJ |
1328 | } |
1329 | ||
e26af52f DJ |
1330 | /* Handle the exit of a single thread LP. */ |
1331 | ||
1332 | static void | |
1333 | exit_lwp (struct lwp_info *lp) | |
1334 | { | |
e09875d4 | 1335 | struct thread_info *th = find_thread_ptid (lp->ptid); |
063bfe2e VP |
1336 | |
1337 | if (th) | |
e26af52f | 1338 | { |
17faa917 DJ |
1339 | if (print_thread_events) |
1340 | printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid)); | |
1341 | ||
4f8d22e3 | 1342 | delete_thread (lp->ptid); |
e26af52f DJ |
1343 | } |
1344 | ||
1345 | delete_lwp (lp->ptid); | |
1346 | } | |
1347 | ||
a0ef4274 DJ |
1348 | /* Wait for the LWP specified by LP, which we have just attached to. |
1349 | Returns a wait status for that LWP, to cache. */ | |
1350 | ||
1351 | static int | |
1352 | linux_nat_post_attach_wait (ptid_t ptid, int first, int *cloned, | |
1353 | int *signalled) | |
1354 | { | |
1355 | pid_t new_pid, pid = GET_LWP (ptid); | |
1356 | int status; | |
1357 | ||
644cebc9 | 1358 | if (linux_proc_pid_is_stopped (pid)) |
a0ef4274 DJ |
1359 | { |
1360 | if (debug_linux_nat) | |
1361 | fprintf_unfiltered (gdb_stdlog, | |
1362 | "LNPAW: Attaching to a stopped process\n"); | |
1363 | ||
1364 | /* The process is definitely stopped. It is in a job control | |
1365 | stop, unless the kernel predates the TASK_STOPPED / | |
1366 | TASK_TRACED distinction, in which case it might be in a | |
1367 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
1368 | can kill it, signal it, et cetera. | |
1369 | ||
1370 | First make sure there is a pending SIGSTOP. Since we are | |
1371 | already attached, the process can not transition from stopped | |
1372 | to running without a PTRACE_CONT; so we know this signal will | |
1373 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
1374 | probably already in the queue (unless this kernel is old | |
1375 | enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP | |
1376 | is not an RT signal, it can only be queued once. */ | |
1377 | kill_lwp (pid, SIGSTOP); | |
1378 | ||
1379 | /* Finally, resume the stopped process. This will deliver the SIGSTOP | |
1380 | (or a higher priority signal, just like normal PTRACE_ATTACH). */ | |
1381 | ptrace (PTRACE_CONT, pid, 0, 0); | |
1382 | } | |
1383 | ||
1384 | /* Make sure the initial process is stopped. The user-level threads | |
1385 | layer might want to poke around in the inferior, and that won't | |
1386 | work if things haven't stabilized yet. */ | |
1387 | new_pid = my_waitpid (pid, &status, 0); | |
1388 | if (new_pid == -1 && errno == ECHILD) | |
1389 | { | |
1390 | if (first) | |
1391 | warning (_("%s is a cloned process"), target_pid_to_str (ptid)); | |
1392 | ||
1393 | /* Try again with __WCLONE to check cloned processes. */ | |
1394 | new_pid = my_waitpid (pid, &status, __WCLONE); | |
1395 | *cloned = 1; | |
1396 | } | |
1397 | ||
dacc9cb2 PP |
1398 | gdb_assert (pid == new_pid); |
1399 | ||
1400 | if (!WIFSTOPPED (status)) | |
1401 | { | |
1402 | /* The pid we tried to attach has apparently just exited. */ | |
1403 | if (debug_linux_nat) | |
1404 | fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s", | |
1405 | pid, status_to_str (status)); | |
1406 | return status; | |
1407 | } | |
a0ef4274 DJ |
1408 | |
1409 | if (WSTOPSIG (status) != SIGSTOP) | |
1410 | { | |
1411 | *signalled = 1; | |
1412 | if (debug_linux_nat) | |
1413 | fprintf_unfiltered (gdb_stdlog, | |
1414 | "LNPAW: Received %s after attaching\n", | |
1415 | status_to_str (status)); | |
1416 | } | |
1417 | ||
1418 | return status; | |
1419 | } | |
1420 | ||
84636d28 PA |
1421 | /* Attach to the LWP specified by PID. Return 0 if successful, -1 if |
1422 | the new LWP could not be attached, or 1 if we're already auto | |
1423 | attached to this thread, but haven't processed the | |
1424 | PTRACE_EVENT_CLONE event of its parent thread, so we just ignore | |
1425 | its existance, without considering it an error. */ | |
d6b0e80f | 1426 | |
9ee57c33 | 1427 | int |
93815fbf | 1428 | lin_lwp_attach_lwp (ptid_t ptid) |
d6b0e80f | 1429 | { |
9ee57c33 | 1430 | struct lwp_info *lp; |
7feb7d06 | 1431 | sigset_t prev_mask; |
84636d28 | 1432 | int lwpid; |
d6b0e80f AC |
1433 | |
1434 | gdb_assert (is_lwp (ptid)); | |
1435 | ||
7feb7d06 | 1436 | block_child_signals (&prev_mask); |
d6b0e80f | 1437 | |
9ee57c33 | 1438 | lp = find_lwp_pid (ptid); |
84636d28 | 1439 | lwpid = GET_LWP (ptid); |
d6b0e80f AC |
1440 | |
1441 | /* We assume that we're already attached to any LWP that has an id | |
1442 | equal to the overall process id, and to any LWP that is already | |
1443 | in our list of LWPs. If we're not seeing exit events from threads | |
1444 | and we've had PID wraparound since we last tried to stop all threads, | |
1445 | this assumption might be wrong; fortunately, this is very unlikely | |
1446 | to happen. */ | |
84636d28 | 1447 | if (lwpid != GET_PID (ptid) && lp == NULL) |
d6b0e80f | 1448 | { |
a0ef4274 | 1449 | int status, cloned = 0, signalled = 0; |
d6b0e80f | 1450 | |
84636d28 | 1451 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) |
9ee57c33 | 1452 | { |
84636d28 PA |
1453 | if (linux_supports_tracefork_flag) |
1454 | { | |
1455 | /* If we haven't stopped all threads when we get here, | |
1456 | we may have seen a thread listed in thread_db's list, | |
1457 | but not processed the PTRACE_EVENT_CLONE yet. If | |
1458 | that's the case, ignore this new thread, and let | |
1459 | normal event handling discover it later. */ | |
1460 | if (in_pid_list_p (stopped_pids, lwpid)) | |
1461 | { | |
1462 | /* We've already seen this thread stop, but we | |
1463 | haven't seen the PTRACE_EVENT_CLONE extended | |
1464 | event yet. */ | |
1465 | restore_child_signals_mask (&prev_mask); | |
1466 | return 0; | |
1467 | } | |
1468 | else | |
1469 | { | |
1470 | int new_pid; | |
1471 | int status; | |
1472 | ||
1473 | /* See if we've got a stop for this new child | |
1474 | pending. If so, we're already attached. */ | |
1475 | new_pid = my_waitpid (lwpid, &status, WNOHANG); | |
1476 | if (new_pid == -1 && errno == ECHILD) | |
1477 | new_pid = my_waitpid (lwpid, &status, __WCLONE | WNOHANG); | |
1478 | if (new_pid != -1) | |
1479 | { | |
1480 | if (WIFSTOPPED (status)) | |
1481 | add_to_pid_list (&stopped_pids, lwpid, status); | |
1482 | ||
1483 | restore_child_signals_mask (&prev_mask); | |
1484 | return 1; | |
1485 | } | |
1486 | } | |
1487 | } | |
1488 | ||
9ee57c33 DJ |
1489 | /* If we fail to attach to the thread, issue a warning, |
1490 | but continue. One way this can happen is if thread | |
e9efe249 | 1491 | creation is interrupted; as of Linux kernel 2.6.19, a |
9ee57c33 DJ |
1492 | bug may place threads in the thread list and then fail |
1493 | to create them. */ | |
1494 | warning (_("Can't attach %s: %s"), target_pid_to_str (ptid), | |
1495 | safe_strerror (errno)); | |
7feb7d06 | 1496 | restore_child_signals_mask (&prev_mask); |
9ee57c33 DJ |
1497 | return -1; |
1498 | } | |
1499 | ||
d6b0e80f AC |
1500 | if (debug_linux_nat) |
1501 | fprintf_unfiltered (gdb_stdlog, | |
1502 | "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n", | |
1503 | target_pid_to_str (ptid)); | |
1504 | ||
a0ef4274 | 1505 | status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled); |
dacc9cb2 | 1506 | if (!WIFSTOPPED (status)) |
673c2bbe DE |
1507 | { |
1508 | restore_child_signals_mask (&prev_mask); | |
f687d035 | 1509 | return 1; |
673c2bbe | 1510 | } |
dacc9cb2 | 1511 | |
a0ef4274 DJ |
1512 | lp = add_lwp (ptid); |
1513 | lp->stopped = 1; | |
1514 | lp->cloned = cloned; | |
1515 | lp->signalled = signalled; | |
1516 | if (WSTOPSIG (status) != SIGSTOP) | |
d6b0e80f | 1517 | { |
a0ef4274 DJ |
1518 | lp->resumed = 1; |
1519 | lp->status = status; | |
d6b0e80f AC |
1520 | } |
1521 | ||
a0ef4274 | 1522 | target_post_attach (GET_LWP (lp->ptid)); |
d6b0e80f AC |
1523 | |
1524 | if (debug_linux_nat) | |
1525 | { | |
1526 | fprintf_unfiltered (gdb_stdlog, | |
1527 | "LLAL: waitpid %s received %s\n", | |
1528 | target_pid_to_str (ptid), | |
1529 | status_to_str (status)); | |
1530 | } | |
1531 | } | |
1532 | else | |
1533 | { | |
1534 | /* We assume that the LWP representing the original process is | |
1535 | already stopped. Mark it as stopped in the data structure | |
155bd5d1 AC |
1536 | that the GNU/linux ptrace layer uses to keep track of |
1537 | threads. Note that this won't have already been done since | |
1538 | the main thread will have, we assume, been stopped by an | |
1539 | attach from a different layer. */ | |
9ee57c33 DJ |
1540 | if (lp == NULL) |
1541 | lp = add_lwp (ptid); | |
d6b0e80f AC |
1542 | lp->stopped = 1; |
1543 | } | |
9ee57c33 | 1544 | |
25289eb2 | 1545 | lp->last_resume_kind = resume_stop; |
7feb7d06 | 1546 | restore_child_signals_mask (&prev_mask); |
9ee57c33 | 1547 | return 0; |
d6b0e80f AC |
1548 | } |
1549 | ||
b84876c2 | 1550 | static void |
136d6dae VP |
1551 | linux_nat_create_inferior (struct target_ops *ops, |
1552 | char *exec_file, char *allargs, char **env, | |
b84876c2 PA |
1553 | int from_tty) |
1554 | { | |
10568435 JK |
1555 | #ifdef HAVE_PERSONALITY |
1556 | int personality_orig = 0, personality_set = 0; | |
1557 | #endif /* HAVE_PERSONALITY */ | |
b84876c2 PA |
1558 | |
1559 | /* The fork_child mechanism is synchronous and calls target_wait, so | |
1560 | we have to mask the async mode. */ | |
1561 | ||
10568435 JK |
1562 | #ifdef HAVE_PERSONALITY |
1563 | if (disable_randomization) | |
1564 | { | |
1565 | errno = 0; | |
1566 | personality_orig = personality (0xffffffff); | |
1567 | if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE)) | |
1568 | { | |
1569 | personality_set = 1; | |
1570 | personality (personality_orig | ADDR_NO_RANDOMIZE); | |
1571 | } | |
1572 | if (errno != 0 || (personality_set | |
1573 | && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE))) | |
1574 | warning (_("Error disabling address space randomization: %s"), | |
1575 | safe_strerror (errno)); | |
1576 | } | |
1577 | #endif /* HAVE_PERSONALITY */ | |
1578 | ||
2455069d UW |
1579 | /* Make sure we report all signals during startup. */ |
1580 | linux_nat_pass_signals (0, NULL); | |
1581 | ||
136d6dae | 1582 | linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty); |
b84876c2 | 1583 | |
10568435 JK |
1584 | #ifdef HAVE_PERSONALITY |
1585 | if (personality_set) | |
1586 | { | |
1587 | errno = 0; | |
1588 | personality (personality_orig); | |
1589 | if (errno != 0) | |
1590 | warning (_("Error restoring address space randomization: %s"), | |
1591 | safe_strerror (errno)); | |
1592 | } | |
1593 | #endif /* HAVE_PERSONALITY */ | |
b84876c2 PA |
1594 | } |
1595 | ||
d6b0e80f | 1596 | static void |
136d6dae | 1597 | linux_nat_attach (struct target_ops *ops, char *args, int from_tty) |
d6b0e80f AC |
1598 | { |
1599 | struct lwp_info *lp; | |
d6b0e80f | 1600 | int status; |
af990527 | 1601 | ptid_t ptid; |
87b0bb13 | 1602 | volatile struct gdb_exception ex; |
d6b0e80f | 1603 | |
2455069d UW |
1604 | /* Make sure we report all signals during attach. */ |
1605 | linux_nat_pass_signals (0, NULL); | |
1606 | ||
87b0bb13 JK |
1607 | TRY_CATCH (ex, RETURN_MASK_ERROR) |
1608 | { | |
1609 | linux_ops->to_attach (ops, args, from_tty); | |
1610 | } | |
1611 | if (ex.reason < 0) | |
1612 | { | |
1613 | pid_t pid = parse_pid_to_attach (args); | |
1614 | struct buffer buffer; | |
1615 | char *message, *buffer_s; | |
1616 | ||
1617 | message = xstrdup (ex.message); | |
1618 | make_cleanup (xfree, message); | |
1619 | ||
1620 | buffer_init (&buffer); | |
1621 | linux_ptrace_attach_warnings (pid, &buffer); | |
1622 | ||
1623 | buffer_grow_str0 (&buffer, ""); | |
1624 | buffer_s = buffer_finish (&buffer); | |
1625 | make_cleanup (xfree, buffer_s); | |
1626 | ||
1627 | throw_error (ex.error, "%s%s", buffer_s, message); | |
1628 | } | |
d6b0e80f | 1629 | |
af990527 PA |
1630 | /* The ptrace base target adds the main thread with (pid,0,0) |
1631 | format. Decorate it with lwp info. */ | |
1632 | ptid = BUILD_LWP (GET_PID (inferior_ptid), GET_PID (inferior_ptid)); | |
1633 | thread_change_ptid (inferior_ptid, ptid); | |
1634 | ||
9f0bdab8 | 1635 | /* Add the initial process as the first LWP to the list. */ |
26cb8b7c | 1636 | lp = add_initial_lwp (ptid); |
a0ef4274 DJ |
1637 | |
1638 | status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->cloned, | |
1639 | &lp->signalled); | |
dacc9cb2 PP |
1640 | if (!WIFSTOPPED (status)) |
1641 | { | |
1642 | if (WIFEXITED (status)) | |
1643 | { | |
1644 | int exit_code = WEXITSTATUS (status); | |
1645 | ||
1646 | target_terminal_ours (); | |
1647 | target_mourn_inferior (); | |
1648 | if (exit_code == 0) | |
1649 | error (_("Unable to attach: program exited normally.")); | |
1650 | else | |
1651 | error (_("Unable to attach: program exited with code %d."), | |
1652 | exit_code); | |
1653 | } | |
1654 | else if (WIFSIGNALED (status)) | |
1655 | { | |
2ea28649 | 1656 | enum gdb_signal signo; |
dacc9cb2 PP |
1657 | |
1658 | target_terminal_ours (); | |
1659 | target_mourn_inferior (); | |
1660 | ||
2ea28649 | 1661 | signo = gdb_signal_from_host (WTERMSIG (status)); |
dacc9cb2 PP |
1662 | error (_("Unable to attach: program terminated with signal " |
1663 | "%s, %s."), | |
2ea28649 PA |
1664 | gdb_signal_to_name (signo), |
1665 | gdb_signal_to_string (signo)); | |
dacc9cb2 PP |
1666 | } |
1667 | ||
1668 | internal_error (__FILE__, __LINE__, | |
1669 | _("unexpected status %d for PID %ld"), | |
1670 | status, (long) GET_LWP (ptid)); | |
1671 | } | |
1672 | ||
a0ef4274 | 1673 | lp->stopped = 1; |
9f0bdab8 | 1674 | |
a0ef4274 | 1675 | /* Save the wait status to report later. */ |
d6b0e80f | 1676 | lp->resumed = 1; |
a0ef4274 DJ |
1677 | if (debug_linux_nat) |
1678 | fprintf_unfiltered (gdb_stdlog, | |
1679 | "LNA: waitpid %ld, saving status %s\n", | |
1680 | (long) GET_PID (lp->ptid), status_to_str (status)); | |
710151dd | 1681 | |
7feb7d06 PA |
1682 | lp->status = status; |
1683 | ||
1684 | if (target_can_async_p ()) | |
1685 | target_async (inferior_event_handler, 0); | |
d6b0e80f AC |
1686 | } |
1687 | ||
a0ef4274 DJ |
1688 | /* Get pending status of LP. */ |
1689 | static int | |
1690 | get_pending_status (struct lwp_info *lp, int *status) | |
1691 | { | |
a493e3e2 | 1692 | enum gdb_signal signo = GDB_SIGNAL_0; |
ca2163eb PA |
1693 | |
1694 | /* If we paused threads momentarily, we may have stored pending | |
1695 | events in lp->status or lp->waitstatus (see stop_wait_callback), | |
1696 | and GDB core hasn't seen any signal for those threads. | |
1697 | Otherwise, the last signal reported to the core is found in the | |
1698 | thread object's stop_signal. | |
1699 | ||
1700 | There's a corner case that isn't handled here at present. Only | |
1701 | if the thread stopped with a TARGET_WAITKIND_STOPPED does | |
1702 | stop_signal make sense as a real signal to pass to the inferior. | |
1703 | Some catchpoint related events, like | |
1704 | TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set | |
a493e3e2 | 1705 | to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But, |
ca2163eb PA |
1706 | those traps are debug API (ptrace in our case) related and |
1707 | induced; the inferior wouldn't see them if it wasn't being | |
1708 | traced. Hence, we should never pass them to the inferior, even | |
1709 | when set to pass state. Since this corner case isn't handled by | |
1710 | infrun.c when proceeding with a signal, for consistency, neither | |
1711 | do we handle it here (or elsewhere in the file we check for | |
1712 | signal pass state). Normally SIGTRAP isn't set to pass state, so | |
1713 | this is really a corner case. */ | |
1714 | ||
1715 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
a493e3e2 | 1716 | signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */ |
ca2163eb | 1717 | else if (lp->status) |
2ea28649 | 1718 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
ca2163eb PA |
1719 | else if (non_stop && !is_executing (lp->ptid)) |
1720 | { | |
1721 | struct thread_info *tp = find_thread_ptid (lp->ptid); | |
e0881a8e | 1722 | |
16c381f0 | 1723 | signo = tp->suspend.stop_signal; |
ca2163eb PA |
1724 | } |
1725 | else if (!non_stop) | |
a0ef4274 | 1726 | { |
ca2163eb PA |
1727 | struct target_waitstatus last; |
1728 | ptid_t last_ptid; | |
4c28f408 | 1729 | |
ca2163eb | 1730 | get_last_target_status (&last_ptid, &last); |
4c28f408 | 1731 | |
ca2163eb PA |
1732 | if (GET_LWP (lp->ptid) == GET_LWP (last_ptid)) |
1733 | { | |
e09875d4 | 1734 | struct thread_info *tp = find_thread_ptid (lp->ptid); |
e0881a8e | 1735 | |
16c381f0 | 1736 | signo = tp->suspend.stop_signal; |
4c28f408 | 1737 | } |
ca2163eb | 1738 | } |
4c28f408 | 1739 | |
ca2163eb | 1740 | *status = 0; |
4c28f408 | 1741 | |
a493e3e2 | 1742 | if (signo == GDB_SIGNAL_0) |
ca2163eb PA |
1743 | { |
1744 | if (debug_linux_nat) | |
1745 | fprintf_unfiltered (gdb_stdlog, | |
1746 | "GPT: lwp %s has no pending signal\n", | |
1747 | target_pid_to_str (lp->ptid)); | |
1748 | } | |
1749 | else if (!signal_pass_state (signo)) | |
1750 | { | |
1751 | if (debug_linux_nat) | |
3e43a32a MS |
1752 | fprintf_unfiltered (gdb_stdlog, |
1753 | "GPT: lwp %s had signal %s, " | |
1754 | "but it is in no pass state\n", | |
ca2163eb | 1755 | target_pid_to_str (lp->ptid), |
2ea28649 | 1756 | gdb_signal_to_string (signo)); |
a0ef4274 | 1757 | } |
a0ef4274 | 1758 | else |
4c28f408 | 1759 | { |
2ea28649 | 1760 | *status = W_STOPCODE (gdb_signal_to_host (signo)); |
ca2163eb PA |
1761 | |
1762 | if (debug_linux_nat) | |
1763 | fprintf_unfiltered (gdb_stdlog, | |
1764 | "GPT: lwp %s has pending signal %s\n", | |
1765 | target_pid_to_str (lp->ptid), | |
2ea28649 | 1766 | gdb_signal_to_string (signo)); |
4c28f408 | 1767 | } |
a0ef4274 DJ |
1768 | |
1769 | return 0; | |
1770 | } | |
1771 | ||
d6b0e80f AC |
1772 | static int |
1773 | detach_callback (struct lwp_info *lp, void *data) | |
1774 | { | |
1775 | gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status)); | |
1776 | ||
1777 | if (debug_linux_nat && lp->status) | |
1778 | fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n", | |
1779 | strsignal (WSTOPSIG (lp->status)), | |
1780 | target_pid_to_str (lp->ptid)); | |
1781 | ||
a0ef4274 DJ |
1782 | /* If there is a pending SIGSTOP, get rid of it. */ |
1783 | if (lp->signalled) | |
d6b0e80f | 1784 | { |
d6b0e80f AC |
1785 | if (debug_linux_nat) |
1786 | fprintf_unfiltered (gdb_stdlog, | |
a0ef4274 DJ |
1787 | "DC: Sending SIGCONT to %s\n", |
1788 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 1789 | |
a0ef4274 | 1790 | kill_lwp (GET_LWP (lp->ptid), SIGCONT); |
d6b0e80f | 1791 | lp->signalled = 0; |
d6b0e80f AC |
1792 | } |
1793 | ||
1794 | /* We don't actually detach from the LWP that has an id equal to the | |
1795 | overall process id just yet. */ | |
1796 | if (GET_LWP (lp->ptid) != GET_PID (lp->ptid)) | |
1797 | { | |
a0ef4274 DJ |
1798 | int status = 0; |
1799 | ||
1800 | /* Pass on any pending signal for this LWP. */ | |
1801 | get_pending_status (lp, &status); | |
1802 | ||
7b50312a PA |
1803 | if (linux_nat_prepare_to_resume != NULL) |
1804 | linux_nat_prepare_to_resume (lp); | |
d6b0e80f AC |
1805 | errno = 0; |
1806 | if (ptrace (PTRACE_DETACH, GET_LWP (lp->ptid), 0, | |
a0ef4274 | 1807 | WSTOPSIG (status)) < 0) |
8a3fe4f8 | 1808 | error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid), |
d6b0e80f AC |
1809 | safe_strerror (errno)); |
1810 | ||
1811 | if (debug_linux_nat) | |
1812 | fprintf_unfiltered (gdb_stdlog, | |
1813 | "PTRACE_DETACH (%s, %s, 0) (OK)\n", | |
1814 | target_pid_to_str (lp->ptid), | |
7feb7d06 | 1815 | strsignal (WSTOPSIG (status))); |
d6b0e80f AC |
1816 | |
1817 | delete_lwp (lp->ptid); | |
1818 | } | |
1819 | ||
1820 | return 0; | |
1821 | } | |
1822 | ||
1823 | static void | |
136d6dae | 1824 | linux_nat_detach (struct target_ops *ops, char *args, int from_tty) |
d6b0e80f | 1825 | { |
b84876c2 | 1826 | int pid; |
a0ef4274 | 1827 | int status; |
d90e17a7 PA |
1828 | struct lwp_info *main_lwp; |
1829 | ||
1830 | pid = GET_PID (inferior_ptid); | |
a0ef4274 | 1831 | |
ae5e0686 MK |
1832 | /* Don't unregister from the event loop, as there may be other |
1833 | inferiors running. */ | |
b84876c2 | 1834 | |
4c28f408 PA |
1835 | /* Stop all threads before detaching. ptrace requires that the |
1836 | thread is stopped to sucessfully detach. */ | |
d90e17a7 | 1837 | iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL); |
4c28f408 PA |
1838 | /* ... and wait until all of them have reported back that |
1839 | they're no longer running. */ | |
d90e17a7 | 1840 | iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL); |
4c28f408 | 1841 | |
d90e17a7 | 1842 | iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL); |
d6b0e80f AC |
1843 | |
1844 | /* Only the initial process should be left right now. */ | |
d90e17a7 PA |
1845 | gdb_assert (num_lwps (GET_PID (inferior_ptid)) == 1); |
1846 | ||
1847 | main_lwp = find_lwp_pid (pid_to_ptid (pid)); | |
d6b0e80f | 1848 | |
a0ef4274 DJ |
1849 | /* Pass on any pending signal for the last LWP. */ |
1850 | if ((args == NULL || *args == '\0') | |
d90e17a7 | 1851 | && get_pending_status (main_lwp, &status) != -1 |
a0ef4274 DJ |
1852 | && WIFSTOPPED (status)) |
1853 | { | |
1854 | /* Put the signal number in ARGS so that inf_ptrace_detach will | |
1855 | pass it along with PTRACE_DETACH. */ | |
1856 | args = alloca (8); | |
1857 | sprintf (args, "%d", (int) WSTOPSIG (status)); | |
ddabfc73 TT |
1858 | if (debug_linux_nat) |
1859 | fprintf_unfiltered (gdb_stdlog, | |
1860 | "LND: Sending signal %s to %s\n", | |
1861 | args, | |
1862 | target_pid_to_str (main_lwp->ptid)); | |
a0ef4274 DJ |
1863 | } |
1864 | ||
7b50312a PA |
1865 | if (linux_nat_prepare_to_resume != NULL) |
1866 | linux_nat_prepare_to_resume (main_lwp); | |
d90e17a7 | 1867 | delete_lwp (main_lwp->ptid); |
b84876c2 | 1868 | |
7a7d3353 PA |
1869 | if (forks_exist_p ()) |
1870 | { | |
1871 | /* Multi-fork case. The current inferior_ptid is being detached | |
1872 | from, but there are other viable forks to debug. Detach from | |
1873 | the current fork, and context-switch to the first | |
1874 | available. */ | |
1875 | linux_fork_detach (args, from_tty); | |
7a7d3353 PA |
1876 | } |
1877 | else | |
1878 | linux_ops->to_detach (ops, args, from_tty); | |
d6b0e80f AC |
1879 | } |
1880 | ||
1881 | /* Resume LP. */ | |
1882 | ||
25289eb2 | 1883 | static void |
e5ef252a | 1884 | resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) |
d6b0e80f | 1885 | { |
25289eb2 | 1886 | if (lp->stopped) |
6c95b8df | 1887 | { |
25289eb2 PA |
1888 | struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid)); |
1889 | ||
1890 | if (inf->vfork_child != NULL) | |
1891 | { | |
1892 | if (debug_linux_nat) | |
1893 | fprintf_unfiltered (gdb_stdlog, | |
1894 | "RC: Not resuming %s (vfork parent)\n", | |
1895 | target_pid_to_str (lp->ptid)); | |
1896 | } | |
1897 | else if (lp->status == 0 | |
1898 | && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) | |
1899 | { | |
1900 | if (debug_linux_nat) | |
1901 | fprintf_unfiltered (gdb_stdlog, | |
e5ef252a PA |
1902 | "RC: Resuming sibling %s, %s, %s\n", |
1903 | target_pid_to_str (lp->ptid), | |
1904 | (signo != GDB_SIGNAL_0 | |
1905 | ? strsignal (gdb_signal_to_host (signo)) | |
1906 | : "0"), | |
1907 | step ? "step" : "resume"); | |
25289eb2 | 1908 | |
7b50312a PA |
1909 | if (linux_nat_prepare_to_resume != NULL) |
1910 | linux_nat_prepare_to_resume (lp); | |
25289eb2 PA |
1911 | linux_ops->to_resume (linux_ops, |
1912 | pid_to_ptid (GET_LWP (lp->ptid)), | |
e5ef252a | 1913 | step, signo); |
25289eb2 PA |
1914 | lp->stopped = 0; |
1915 | lp->step = step; | |
25289eb2 PA |
1916 | lp->stopped_by_watchpoint = 0; |
1917 | } | |
1918 | else | |
1919 | { | |
1920 | if (debug_linux_nat) | |
1921 | fprintf_unfiltered (gdb_stdlog, | |
1922 | "RC: Not resuming sibling %s (has pending)\n", | |
1923 | target_pid_to_str (lp->ptid)); | |
1924 | } | |
6c95b8df | 1925 | } |
25289eb2 | 1926 | else |
d6b0e80f | 1927 | { |
d90e17a7 PA |
1928 | if (debug_linux_nat) |
1929 | fprintf_unfiltered (gdb_stdlog, | |
25289eb2 | 1930 | "RC: Not resuming sibling %s (not stopped)\n", |
d6b0e80f | 1931 | target_pid_to_str (lp->ptid)); |
d6b0e80f | 1932 | } |
25289eb2 | 1933 | } |
d6b0e80f | 1934 | |
e5ef252a PA |
1935 | /* Resume LWP, with the last stop signal, if it is in pass state. */ |
1936 | ||
25289eb2 | 1937 | static int |
e5ef252a | 1938 | linux_nat_resume_callback (struct lwp_info *lp, void *data) |
25289eb2 | 1939 | { |
e5ef252a PA |
1940 | enum gdb_signal signo = GDB_SIGNAL_0; |
1941 | ||
1942 | if (lp->stopped) | |
1943 | { | |
1944 | struct thread_info *thread; | |
1945 | ||
1946 | thread = find_thread_ptid (lp->ptid); | |
1947 | if (thread != NULL) | |
1948 | { | |
1949 | if (signal_pass_state (thread->suspend.stop_signal)) | |
1950 | signo = thread->suspend.stop_signal; | |
1951 | thread->suspend.stop_signal = GDB_SIGNAL_0; | |
1952 | } | |
1953 | } | |
1954 | ||
1955 | resume_lwp (lp, 0, signo); | |
d6b0e80f AC |
1956 | return 0; |
1957 | } | |
1958 | ||
1959 | static int | |
1960 | resume_clear_callback (struct lwp_info *lp, void *data) | |
1961 | { | |
1962 | lp->resumed = 0; | |
25289eb2 | 1963 | lp->last_resume_kind = resume_stop; |
d6b0e80f AC |
1964 | return 0; |
1965 | } | |
1966 | ||
1967 | static int | |
1968 | resume_set_callback (struct lwp_info *lp, void *data) | |
1969 | { | |
1970 | lp->resumed = 1; | |
25289eb2 | 1971 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1972 | return 0; |
1973 | } | |
1974 | ||
1975 | static void | |
28439f5e | 1976 | linux_nat_resume (struct target_ops *ops, |
2ea28649 | 1977 | ptid_t ptid, int step, enum gdb_signal signo) |
d6b0e80f | 1978 | { |
7feb7d06 | 1979 | sigset_t prev_mask; |
d6b0e80f | 1980 | struct lwp_info *lp; |
d90e17a7 | 1981 | int resume_many; |
d6b0e80f | 1982 | |
76f50ad1 DJ |
1983 | if (debug_linux_nat) |
1984 | fprintf_unfiltered (gdb_stdlog, | |
1985 | "LLR: Preparing to %s %s, %s, inferior_ptid %s\n", | |
1986 | step ? "step" : "resume", | |
1987 | target_pid_to_str (ptid), | |
a493e3e2 | 1988 | (signo != GDB_SIGNAL_0 |
2ea28649 | 1989 | ? strsignal (gdb_signal_to_host (signo)) : "0"), |
76f50ad1 DJ |
1990 | target_pid_to_str (inferior_ptid)); |
1991 | ||
7feb7d06 | 1992 | block_child_signals (&prev_mask); |
b84876c2 | 1993 | |
d6b0e80f | 1994 | /* A specific PTID means `step only this process id'. */ |
d90e17a7 PA |
1995 | resume_many = (ptid_equal (minus_one_ptid, ptid) |
1996 | || ptid_is_pid (ptid)); | |
4c28f408 | 1997 | |
e3e9f5a2 PA |
1998 | /* Mark the lwps we're resuming as resumed. */ |
1999 | iterate_over_lwps (ptid, resume_set_callback, NULL); | |
d6b0e80f | 2000 | |
d90e17a7 PA |
2001 | /* See if it's the current inferior that should be handled |
2002 | specially. */ | |
2003 | if (resume_many) | |
2004 | lp = find_lwp_pid (inferior_ptid); | |
2005 | else | |
2006 | lp = find_lwp_pid (ptid); | |
9f0bdab8 | 2007 | gdb_assert (lp != NULL); |
d6b0e80f | 2008 | |
9f0bdab8 DJ |
2009 | /* Remember if we're stepping. */ |
2010 | lp->step = step; | |
25289eb2 | 2011 | lp->last_resume_kind = step ? resume_step : resume_continue; |
d6b0e80f | 2012 | |
9f0bdab8 DJ |
2013 | /* If we have a pending wait status for this thread, there is no |
2014 | point in resuming the process. But first make sure that | |
2015 | linux_nat_wait won't preemptively handle the event - we | |
2016 | should never take this short-circuit if we are going to | |
2017 | leave LP running, since we have skipped resuming all the | |
2018 | other threads. This bit of code needs to be synchronized | |
2019 | with linux_nat_wait. */ | |
76f50ad1 | 2020 | |
9f0bdab8 DJ |
2021 | if (lp->status && WIFSTOPPED (lp->status)) |
2022 | { | |
2455069d UW |
2023 | if (!lp->step |
2024 | && WSTOPSIG (lp->status) | |
2025 | && sigismember (&pass_mask, WSTOPSIG (lp->status))) | |
d6b0e80f | 2026 | { |
9f0bdab8 DJ |
2027 | if (debug_linux_nat) |
2028 | fprintf_unfiltered (gdb_stdlog, | |
2029 | "LLR: Not short circuiting for ignored " | |
2030 | "status 0x%x\n", lp->status); | |
2031 | ||
d6b0e80f AC |
2032 | /* FIXME: What should we do if we are supposed to continue |
2033 | this thread with a signal? */ | |
a493e3e2 | 2034 | gdb_assert (signo == GDB_SIGNAL_0); |
2ea28649 | 2035 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
9f0bdab8 DJ |
2036 | lp->status = 0; |
2037 | } | |
2038 | } | |
76f50ad1 | 2039 | |
6c95b8df | 2040 | if (lp->status || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) |
9f0bdab8 DJ |
2041 | { |
2042 | /* FIXME: What should we do if we are supposed to continue | |
2043 | this thread with a signal? */ | |
a493e3e2 | 2044 | gdb_assert (signo == GDB_SIGNAL_0); |
76f50ad1 | 2045 | |
9f0bdab8 DJ |
2046 | if (debug_linux_nat) |
2047 | fprintf_unfiltered (gdb_stdlog, | |
2048 | "LLR: Short circuiting for status 0x%x\n", | |
2049 | lp->status); | |
d6b0e80f | 2050 | |
7feb7d06 PA |
2051 | restore_child_signals_mask (&prev_mask); |
2052 | if (target_can_async_p ()) | |
2053 | { | |
2054 | target_async (inferior_event_handler, 0); | |
2055 | /* Tell the event loop we have something to process. */ | |
2056 | async_file_mark (); | |
2057 | } | |
9f0bdab8 | 2058 | return; |
d6b0e80f AC |
2059 | } |
2060 | ||
9f0bdab8 | 2061 | /* Mark LWP as not stopped to prevent it from being continued by |
e5ef252a | 2062 | linux_nat_resume_callback. */ |
9f0bdab8 DJ |
2063 | lp->stopped = 0; |
2064 | ||
d90e17a7 | 2065 | if (resume_many) |
e5ef252a | 2066 | iterate_over_lwps (ptid, linux_nat_resume_callback, NULL); |
d90e17a7 PA |
2067 | |
2068 | /* Convert to something the lower layer understands. */ | |
2069 | ptid = pid_to_ptid (GET_LWP (lp->ptid)); | |
d6b0e80f | 2070 | |
7b50312a PA |
2071 | if (linux_nat_prepare_to_resume != NULL) |
2072 | linux_nat_prepare_to_resume (lp); | |
28439f5e | 2073 | linux_ops->to_resume (linux_ops, ptid, step, signo); |
ebec9a0f | 2074 | lp->stopped_by_watchpoint = 0; |
9f0bdab8 | 2075 | |
d6b0e80f AC |
2076 | if (debug_linux_nat) |
2077 | fprintf_unfiltered (gdb_stdlog, | |
2078 | "LLR: %s %s, %s (resume event thread)\n", | |
2079 | step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
2080 | target_pid_to_str (ptid), | |
a493e3e2 | 2081 | (signo != GDB_SIGNAL_0 |
2ea28649 | 2082 | ? strsignal (gdb_signal_to_host (signo)) : "0")); |
b84876c2 | 2083 | |
7feb7d06 | 2084 | restore_child_signals_mask (&prev_mask); |
b84876c2 | 2085 | if (target_can_async_p ()) |
8ea051c5 | 2086 | target_async (inferior_event_handler, 0); |
d6b0e80f AC |
2087 | } |
2088 | ||
c5f62d5f | 2089 | /* Send a signal to an LWP. */ |
d6b0e80f AC |
2090 | |
2091 | static int | |
2092 | kill_lwp (int lwpid, int signo) | |
2093 | { | |
c5f62d5f DE |
2094 | /* Use tkill, if possible, in case we are using nptl threads. If tkill |
2095 | fails, then we are not using nptl threads and we should be using kill. */ | |
d6b0e80f AC |
2096 | |
2097 | #ifdef HAVE_TKILL_SYSCALL | |
c5f62d5f DE |
2098 | { |
2099 | static int tkill_failed; | |
2100 | ||
2101 | if (!tkill_failed) | |
2102 | { | |
2103 | int ret; | |
2104 | ||
2105 | errno = 0; | |
2106 | ret = syscall (__NR_tkill, lwpid, signo); | |
2107 | if (errno != ENOSYS) | |
2108 | return ret; | |
2109 | tkill_failed = 1; | |
2110 | } | |
2111 | } | |
d6b0e80f AC |
2112 | #endif |
2113 | ||
2114 | return kill (lwpid, signo); | |
2115 | } | |
2116 | ||
ca2163eb PA |
2117 | /* Handle a GNU/Linux syscall trap wait response. If we see a syscall |
2118 | event, check if the core is interested in it: if not, ignore the | |
2119 | event, and keep waiting; otherwise, we need to toggle the LWP's | |
2120 | syscall entry/exit status, since the ptrace event itself doesn't | |
2121 | indicate it, and report the trap to higher layers. */ | |
2122 | ||
2123 | static int | |
2124 | linux_handle_syscall_trap (struct lwp_info *lp, int stopping) | |
2125 | { | |
2126 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
2127 | struct gdbarch *gdbarch = target_thread_architecture (lp->ptid); | |
2128 | int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid); | |
2129 | ||
2130 | if (stopping) | |
2131 | { | |
2132 | /* If we're stopping threads, there's a SIGSTOP pending, which | |
2133 | makes it so that the LWP reports an immediate syscall return, | |
2134 | followed by the SIGSTOP. Skip seeing that "return" using | |
2135 | PTRACE_CONT directly, and let stop_wait_callback collect the | |
2136 | SIGSTOP. Later when the thread is resumed, a new syscall | |
2137 | entry event. If we didn't do this (and returned 0), we'd | |
2138 | leave a syscall entry pending, and our caller, by using | |
2139 | PTRACE_CONT to collect the SIGSTOP, skips the syscall return | |
2140 | itself. Later, when the user re-resumes this LWP, we'd see | |
2141 | another syscall entry event and we'd mistake it for a return. | |
2142 | ||
2143 | If stop_wait_callback didn't force the SIGSTOP out of the LWP | |
2144 | (leaving immediately with LWP->signalled set, without issuing | |
2145 | a PTRACE_CONT), it would still be problematic to leave this | |
2146 | syscall enter pending, as later when the thread is resumed, | |
2147 | it would then see the same syscall exit mentioned above, | |
2148 | followed by the delayed SIGSTOP, while the syscall didn't | |
2149 | actually get to execute. It seems it would be even more | |
2150 | confusing to the user. */ | |
2151 | ||
2152 | if (debug_linux_nat) | |
2153 | fprintf_unfiltered (gdb_stdlog, | |
2154 | "LHST: ignoring syscall %d " | |
2155 | "for LWP %ld (stopping threads), " | |
2156 | "resuming with PTRACE_CONT for SIGSTOP\n", | |
2157 | syscall_number, | |
2158 | GET_LWP (lp->ptid)); | |
2159 | ||
2160 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2161 | ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); | |
2162 | return 1; | |
2163 | } | |
2164 | ||
2165 | if (catch_syscall_enabled ()) | |
2166 | { | |
2167 | /* Always update the entry/return state, even if this particular | |
2168 | syscall isn't interesting to the core now. In async mode, | |
2169 | the user could install a new catchpoint for this syscall | |
2170 | between syscall enter/return, and we'll need to know to | |
2171 | report a syscall return if that happens. */ | |
2172 | lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
2173 | ? TARGET_WAITKIND_SYSCALL_RETURN | |
2174 | : TARGET_WAITKIND_SYSCALL_ENTRY); | |
2175 | ||
2176 | if (catching_syscall_number (syscall_number)) | |
2177 | { | |
2178 | /* Alright, an event to report. */ | |
2179 | ourstatus->kind = lp->syscall_state; | |
2180 | ourstatus->value.syscall_number = syscall_number; | |
2181 | ||
2182 | if (debug_linux_nat) | |
2183 | fprintf_unfiltered (gdb_stdlog, | |
2184 | "LHST: stopping for %s of syscall %d" | |
2185 | " for LWP %ld\n", | |
3e43a32a MS |
2186 | lp->syscall_state |
2187 | == TARGET_WAITKIND_SYSCALL_ENTRY | |
ca2163eb PA |
2188 | ? "entry" : "return", |
2189 | syscall_number, | |
2190 | GET_LWP (lp->ptid)); | |
2191 | return 0; | |
2192 | } | |
2193 | ||
2194 | if (debug_linux_nat) | |
2195 | fprintf_unfiltered (gdb_stdlog, | |
2196 | "LHST: ignoring %s of syscall %d " | |
2197 | "for LWP %ld\n", | |
2198 | lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
2199 | ? "entry" : "return", | |
2200 | syscall_number, | |
2201 | GET_LWP (lp->ptid)); | |
2202 | } | |
2203 | else | |
2204 | { | |
2205 | /* If we had been syscall tracing, and hence used PT_SYSCALL | |
2206 | before on this LWP, it could happen that the user removes all | |
2207 | syscall catchpoints before we get to process this event. | |
2208 | There are two noteworthy issues here: | |
2209 | ||
2210 | - When stopped at a syscall entry event, resuming with | |
2211 | PT_STEP still resumes executing the syscall and reports a | |
2212 | syscall return. | |
2213 | ||
2214 | - Only PT_SYSCALL catches syscall enters. If we last | |
2215 | single-stepped this thread, then this event can't be a | |
2216 | syscall enter. If we last single-stepped this thread, this | |
2217 | has to be a syscall exit. | |
2218 | ||
2219 | The points above mean that the next resume, be it PT_STEP or | |
2220 | PT_CONTINUE, can not trigger a syscall trace event. */ | |
2221 | if (debug_linux_nat) | |
2222 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
2223 | "LHST: caught syscall event " |
2224 | "with no syscall catchpoints." | |
ca2163eb PA |
2225 | " %d for LWP %ld, ignoring\n", |
2226 | syscall_number, | |
2227 | GET_LWP (lp->ptid)); | |
2228 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2229 | } | |
2230 | ||
2231 | /* The core isn't interested in this event. For efficiency, avoid | |
2232 | stopping all threads only to have the core resume them all again. | |
2233 | Since we're not stopping threads, if we're still syscall tracing | |
2234 | and not stepping, we can't use PTRACE_CONT here, as we'd miss any | |
2235 | subsequent syscall. Simply resume using the inf-ptrace layer, | |
2236 | which knows when to use PT_SYSCALL or PT_CONTINUE. */ | |
2237 | ||
2238 | /* Note that gdbarch_get_syscall_number may access registers, hence | |
2239 | fill a regcache. */ | |
2240 | registers_changed (); | |
7b50312a PA |
2241 | if (linux_nat_prepare_to_resume != NULL) |
2242 | linux_nat_prepare_to_resume (lp); | |
ca2163eb | 2243 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
a493e3e2 | 2244 | lp->step, GDB_SIGNAL_0); |
ca2163eb PA |
2245 | return 1; |
2246 | } | |
2247 | ||
3d799a95 DJ |
2248 | /* Handle a GNU/Linux extended wait response. If we see a clone |
2249 | event, we need to add the new LWP to our list (and not report the | |
2250 | trap to higher layers). This function returns non-zero if the | |
2251 | event should be ignored and we should wait again. If STOPPING is | |
2252 | true, the new LWP remains stopped, otherwise it is continued. */ | |
d6b0e80f AC |
2253 | |
2254 | static int | |
3d799a95 DJ |
2255 | linux_handle_extended_wait (struct lwp_info *lp, int status, |
2256 | int stopping) | |
d6b0e80f | 2257 | { |
3d799a95 DJ |
2258 | int pid = GET_LWP (lp->ptid); |
2259 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
3d799a95 | 2260 | int event = status >> 16; |
d6b0e80f | 2261 | |
3d799a95 DJ |
2262 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
2263 | || event == PTRACE_EVENT_CLONE) | |
d6b0e80f | 2264 | { |
3d799a95 DJ |
2265 | unsigned long new_pid; |
2266 | int ret; | |
2267 | ||
2268 | ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); | |
6fc19103 | 2269 | |
3d799a95 DJ |
2270 | /* If we haven't already seen the new PID stop, wait for it now. */ |
2271 | if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
2272 | { | |
2273 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
2274 | hits the SIGSTOP, but we're already attached. */ | |
2275 | ret = my_waitpid (new_pid, &status, | |
2276 | (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0); | |
2277 | if (ret == -1) | |
2278 | perror_with_name (_("waiting for new child")); | |
2279 | else if (ret != new_pid) | |
2280 | internal_error (__FILE__, __LINE__, | |
2281 | _("wait returned unexpected PID %d"), ret); | |
2282 | else if (!WIFSTOPPED (status)) | |
2283 | internal_error (__FILE__, __LINE__, | |
2284 | _("wait returned unexpected status 0x%x"), status); | |
2285 | } | |
2286 | ||
3a3e9ee3 | 2287 | ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0); |
3d799a95 | 2288 | |
26cb8b7c PA |
2289 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) |
2290 | { | |
2291 | /* The arch-specific native code may need to know about new | |
2292 | forks even if those end up never mapped to an | |
2293 | inferior. */ | |
2294 | if (linux_nat_new_fork != NULL) | |
2295 | linux_nat_new_fork (lp, new_pid); | |
2296 | } | |
2297 | ||
2277426b PA |
2298 | if (event == PTRACE_EVENT_FORK |
2299 | && linux_fork_checkpointing_p (GET_PID (lp->ptid))) | |
2300 | { | |
2277426b PA |
2301 | /* Handle checkpointing by linux-fork.c here as a special |
2302 | case. We don't want the follow-fork-mode or 'catch fork' | |
2303 | to interfere with this. */ | |
2304 | ||
2305 | /* This won't actually modify the breakpoint list, but will | |
2306 | physically remove the breakpoints from the child. */ | |
d80ee84f | 2307 | detach_breakpoints (ptid_build (new_pid, new_pid, 0)); |
2277426b PA |
2308 | |
2309 | /* Retain child fork in ptrace (stopped) state. */ | |
14571dad MS |
2310 | if (!find_fork_pid (new_pid)) |
2311 | add_fork (new_pid); | |
2277426b PA |
2312 | |
2313 | /* Report as spurious, so that infrun doesn't want to follow | |
2314 | this fork. We're actually doing an infcall in | |
2315 | linux-fork.c. */ | |
2316 | ourstatus->kind = TARGET_WAITKIND_SPURIOUS; | |
2277426b PA |
2317 | |
2318 | /* Report the stop to the core. */ | |
2319 | return 0; | |
2320 | } | |
2321 | ||
3d799a95 DJ |
2322 | if (event == PTRACE_EVENT_FORK) |
2323 | ourstatus->kind = TARGET_WAITKIND_FORKED; | |
2324 | else if (event == PTRACE_EVENT_VFORK) | |
2325 | ourstatus->kind = TARGET_WAITKIND_VFORKED; | |
6fc19103 | 2326 | else |
3d799a95 | 2327 | { |
78768c4a JK |
2328 | struct lwp_info *new_lp; |
2329 | ||
3d799a95 | 2330 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
78768c4a | 2331 | |
3c4d7e12 PA |
2332 | if (debug_linux_nat) |
2333 | fprintf_unfiltered (gdb_stdlog, | |
2334 | "LHEW: Got clone event " | |
2335 | "from LWP %d, new child is LWP %ld\n", | |
2336 | pid, new_pid); | |
2337 | ||
d90e17a7 | 2338 | new_lp = add_lwp (BUILD_LWP (new_pid, GET_PID (lp->ptid))); |
3d799a95 | 2339 | new_lp->cloned = 1; |
4c28f408 | 2340 | new_lp->stopped = 1; |
d6b0e80f | 2341 | |
3d799a95 DJ |
2342 | if (WSTOPSIG (status) != SIGSTOP) |
2343 | { | |
2344 | /* This can happen if someone starts sending signals to | |
2345 | the new thread before it gets a chance to run, which | |
2346 | have a lower number than SIGSTOP (e.g. SIGUSR1). | |
2347 | This is an unlikely case, and harder to handle for | |
2348 | fork / vfork than for clone, so we do not try - but | |
2349 | we handle it for clone events here. We'll send | |
2350 | the other signal on to the thread below. */ | |
2351 | ||
2352 | new_lp->signalled = 1; | |
2353 | } | |
2354 | else | |
79395f92 PA |
2355 | { |
2356 | struct thread_info *tp; | |
2357 | ||
2358 | /* When we stop for an event in some other thread, and | |
2359 | pull the thread list just as this thread has cloned, | |
2360 | we'll have seen the new thread in the thread_db list | |
2361 | before handling the CLONE event (glibc's | |
2362 | pthread_create adds the new thread to the thread list | |
2363 | before clone'ing, and has the kernel fill in the | |
2364 | thread's tid on the clone call with | |
2365 | CLONE_PARENT_SETTID). If that happened, and the core | |
2366 | had requested the new thread to stop, we'll have | |
2367 | killed it with SIGSTOP. But since SIGSTOP is not an | |
2368 | RT signal, it can only be queued once. We need to be | |
2369 | careful to not resume the LWP if we wanted it to | |
2370 | stop. In that case, we'll leave the SIGSTOP pending. | |
a493e3e2 | 2371 | It will later be reported as GDB_SIGNAL_0. */ |
79395f92 PA |
2372 | tp = find_thread_ptid (new_lp->ptid); |
2373 | if (tp != NULL && tp->stop_requested) | |
2374 | new_lp->last_resume_kind = resume_stop; | |
2375 | else | |
2376 | status = 0; | |
2377 | } | |
d6b0e80f | 2378 | |
4c28f408 | 2379 | if (non_stop) |
3d799a95 | 2380 | { |
4c28f408 PA |
2381 | /* Add the new thread to GDB's lists as soon as possible |
2382 | so that: | |
2383 | ||
2384 | 1) the frontend doesn't have to wait for a stop to | |
2385 | display them, and, | |
2386 | ||
2387 | 2) we tag it with the correct running state. */ | |
2388 | ||
2389 | /* If the thread_db layer is active, let it know about | |
2390 | this new thread, and add it to GDB's list. */ | |
2391 | if (!thread_db_attach_lwp (new_lp->ptid)) | |
2392 | { | |
2393 | /* We're not using thread_db. Add it to GDB's | |
2394 | list. */ | |
2395 | target_post_attach (GET_LWP (new_lp->ptid)); | |
2396 | add_thread (new_lp->ptid); | |
2397 | } | |
2398 | ||
2399 | if (!stopping) | |
2400 | { | |
2401 | set_running (new_lp->ptid, 1); | |
2402 | set_executing (new_lp->ptid, 1); | |
e21ffe51 PA |
2403 | /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced |
2404 | resume_stop. */ | |
2405 | new_lp->last_resume_kind = resume_continue; | |
4c28f408 PA |
2406 | } |
2407 | } | |
2408 | ||
79395f92 PA |
2409 | if (status != 0) |
2410 | { | |
2411 | /* We created NEW_LP so it cannot yet contain STATUS. */ | |
2412 | gdb_assert (new_lp->status == 0); | |
2413 | ||
2414 | /* Save the wait status to report later. */ | |
2415 | if (debug_linux_nat) | |
2416 | fprintf_unfiltered (gdb_stdlog, | |
2417 | "LHEW: waitpid of new LWP %ld, " | |
2418 | "saving status %s\n", | |
2419 | (long) GET_LWP (new_lp->ptid), | |
2420 | status_to_str (status)); | |
2421 | new_lp->status = status; | |
2422 | } | |
2423 | ||
ca2163eb PA |
2424 | /* Note the need to use the low target ops to resume, to |
2425 | handle resuming with PT_SYSCALL if we have syscall | |
2426 | catchpoints. */ | |
4c28f408 PA |
2427 | if (!stopping) |
2428 | { | |
3d799a95 | 2429 | new_lp->resumed = 1; |
ca2163eb | 2430 | |
79395f92 | 2431 | if (status == 0) |
ad34eb2f | 2432 | { |
e21ffe51 | 2433 | gdb_assert (new_lp->last_resume_kind == resume_continue); |
ad34eb2f JK |
2434 | if (debug_linux_nat) |
2435 | fprintf_unfiltered (gdb_stdlog, | |
79395f92 PA |
2436 | "LHEW: resuming new LWP %ld\n", |
2437 | GET_LWP (new_lp->ptid)); | |
7b50312a PA |
2438 | if (linux_nat_prepare_to_resume != NULL) |
2439 | linux_nat_prepare_to_resume (new_lp); | |
79395f92 | 2440 | linux_ops->to_resume (linux_ops, pid_to_ptid (new_pid), |
a493e3e2 | 2441 | 0, GDB_SIGNAL_0); |
79395f92 | 2442 | new_lp->stopped = 0; |
ad34eb2f JK |
2443 | } |
2444 | } | |
d6b0e80f | 2445 | |
3d799a95 DJ |
2446 | if (debug_linux_nat) |
2447 | fprintf_unfiltered (gdb_stdlog, | |
3c4d7e12 | 2448 | "LHEW: resuming parent LWP %d\n", pid); |
7b50312a PA |
2449 | if (linux_nat_prepare_to_resume != NULL) |
2450 | linux_nat_prepare_to_resume (lp); | |
ca2163eb | 2451 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
a493e3e2 | 2452 | 0, GDB_SIGNAL_0); |
3d799a95 DJ |
2453 | |
2454 | return 1; | |
2455 | } | |
2456 | ||
2457 | return 0; | |
d6b0e80f AC |
2458 | } |
2459 | ||
3d799a95 DJ |
2460 | if (event == PTRACE_EVENT_EXEC) |
2461 | { | |
a75724bc PA |
2462 | if (debug_linux_nat) |
2463 | fprintf_unfiltered (gdb_stdlog, | |
2464 | "LHEW: Got exec event from LWP %ld\n", | |
2465 | GET_LWP (lp->ptid)); | |
2466 | ||
3d799a95 DJ |
2467 | ourstatus->kind = TARGET_WAITKIND_EXECD; |
2468 | ourstatus->value.execd_pathname | |
6d8fd2b7 | 2469 | = xstrdup (linux_child_pid_to_exec_file (pid)); |
3d799a95 | 2470 | |
6c95b8df PA |
2471 | return 0; |
2472 | } | |
2473 | ||
2474 | if (event == PTRACE_EVENT_VFORK_DONE) | |
2475 | { | |
2476 | if (current_inferior ()->waiting_for_vfork_done) | |
3d799a95 | 2477 | { |
6c95b8df | 2478 | if (debug_linux_nat) |
3e43a32a MS |
2479 | fprintf_unfiltered (gdb_stdlog, |
2480 | "LHEW: Got expected PTRACE_EVENT_" | |
2481 | "VFORK_DONE from LWP %ld: stopping\n", | |
6c95b8df | 2482 | GET_LWP (lp->ptid)); |
3d799a95 | 2483 | |
6c95b8df PA |
2484 | ourstatus->kind = TARGET_WAITKIND_VFORK_DONE; |
2485 | return 0; | |
3d799a95 DJ |
2486 | } |
2487 | ||
6c95b8df | 2488 | if (debug_linux_nat) |
3e43a32a MS |
2489 | fprintf_unfiltered (gdb_stdlog, |
2490 | "LHEW: Got PTRACE_EVENT_VFORK_DONE " | |
2491 | "from LWP %ld: resuming\n", | |
6c95b8df PA |
2492 | GET_LWP (lp->ptid)); |
2493 | ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); | |
2494 | return 1; | |
3d799a95 DJ |
2495 | } |
2496 | ||
2497 | internal_error (__FILE__, __LINE__, | |
2498 | _("unknown ptrace event %d"), event); | |
d6b0e80f AC |
2499 | } |
2500 | ||
2501 | /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has | |
2502 | exited. */ | |
2503 | ||
2504 | static int | |
2505 | wait_lwp (struct lwp_info *lp) | |
2506 | { | |
2507 | pid_t pid; | |
432b4d03 | 2508 | int status = 0; |
d6b0e80f | 2509 | int thread_dead = 0; |
432b4d03 | 2510 | sigset_t prev_mask; |
d6b0e80f AC |
2511 | |
2512 | gdb_assert (!lp->stopped); | |
2513 | gdb_assert (lp->status == 0); | |
2514 | ||
432b4d03 JK |
2515 | /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
2516 | block_child_signals (&prev_mask); | |
2517 | ||
2518 | for (;;) | |
d6b0e80f | 2519 | { |
432b4d03 JK |
2520 | /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind |
2521 | was right and we should just call sigsuspend. */ | |
2522 | ||
2523 | pid = my_waitpid (GET_LWP (lp->ptid), &status, WNOHANG); | |
d6b0e80f | 2524 | if (pid == -1 && errno == ECHILD) |
432b4d03 | 2525 | pid = my_waitpid (GET_LWP (lp->ptid), &status, __WCLONE | WNOHANG); |
a9f4bb21 PA |
2526 | if (pid == -1 && errno == ECHILD) |
2527 | { | |
2528 | /* The thread has previously exited. We need to delete it | |
2529 | now because, for some vendor 2.4 kernels with NPTL | |
2530 | support backported, there won't be an exit event unless | |
2531 | it is the main thread. 2.6 kernels will report an exit | |
2532 | event for each thread that exits, as expected. */ | |
2533 | thread_dead = 1; | |
2534 | if (debug_linux_nat) | |
2535 | fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n", | |
2536 | target_pid_to_str (lp->ptid)); | |
2537 | } | |
432b4d03 JK |
2538 | if (pid != 0) |
2539 | break; | |
2540 | ||
2541 | /* Bugs 10970, 12702. | |
2542 | Thread group leader may have exited in which case we'll lock up in | |
2543 | waitpid if there are other threads, even if they are all zombies too. | |
2544 | Basically, we're not supposed to use waitpid this way. | |
2545 | __WCLONE is not applicable for the leader so we can't use that. | |
2546 | LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED | |
2547 | process; it gets ESRCH both for the zombie and for running processes. | |
2548 | ||
2549 | As a workaround, check if we're waiting for the thread group leader and | |
2550 | if it's a zombie, and avoid calling waitpid if it is. | |
2551 | ||
2552 | This is racy, what if the tgl becomes a zombie right after we check? | |
2553 | Therefore always use WNOHANG with sigsuspend - it is equivalent to | |
5f572dec | 2554 | waiting waitpid but linux_proc_pid_is_zombie is safe this way. */ |
432b4d03 JK |
2555 | |
2556 | if (GET_PID (lp->ptid) == GET_LWP (lp->ptid) | |
5f572dec | 2557 | && linux_proc_pid_is_zombie (GET_LWP (lp->ptid))) |
d6b0e80f | 2558 | { |
d6b0e80f AC |
2559 | thread_dead = 1; |
2560 | if (debug_linux_nat) | |
432b4d03 JK |
2561 | fprintf_unfiltered (gdb_stdlog, |
2562 | "WL: Thread group leader %s vanished.\n", | |
d6b0e80f | 2563 | target_pid_to_str (lp->ptid)); |
432b4d03 | 2564 | break; |
d6b0e80f | 2565 | } |
432b4d03 JK |
2566 | |
2567 | /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers | |
2568 | get invoked despite our caller had them intentionally blocked by | |
2569 | block_child_signals. This is sensitive only to the loop of | |
2570 | linux_nat_wait_1 and there if we get called my_waitpid gets called | |
2571 | again before it gets to sigsuspend so we can safely let the handlers | |
2572 | get executed here. */ | |
2573 | ||
2574 | sigsuspend (&suspend_mask); | |
2575 | } | |
2576 | ||
2577 | restore_child_signals_mask (&prev_mask); | |
2578 | ||
d6b0e80f AC |
2579 | if (!thread_dead) |
2580 | { | |
2581 | gdb_assert (pid == GET_LWP (lp->ptid)); | |
2582 | ||
2583 | if (debug_linux_nat) | |
2584 | { | |
2585 | fprintf_unfiltered (gdb_stdlog, | |
2586 | "WL: waitpid %s received %s\n", | |
2587 | target_pid_to_str (lp->ptid), | |
2588 | status_to_str (status)); | |
2589 | } | |
d6b0e80f | 2590 | |
a9f4bb21 PA |
2591 | /* Check if the thread has exited. */ |
2592 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
2593 | { | |
2594 | thread_dead = 1; | |
2595 | if (debug_linux_nat) | |
2596 | fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n", | |
2597 | target_pid_to_str (lp->ptid)); | |
2598 | } | |
d6b0e80f AC |
2599 | } |
2600 | ||
2601 | if (thread_dead) | |
2602 | { | |
e26af52f | 2603 | exit_lwp (lp); |
d6b0e80f AC |
2604 | return 0; |
2605 | } | |
2606 | ||
2607 | gdb_assert (WIFSTOPPED (status)); | |
2608 | ||
ca2163eb PA |
2609 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2610 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2611 | { | |
2612 | /* No longer need the sysgood bit. The ptrace event ends up | |
2613 | recorded in lp->waitstatus if we care for it. We can carry | |
2614 | on handling the event like a regular SIGTRAP from here | |
2615 | on. */ | |
2616 | status = W_STOPCODE (SIGTRAP); | |
2617 | if (linux_handle_syscall_trap (lp, 1)) | |
2618 | return wait_lwp (lp); | |
2619 | } | |
2620 | ||
d6b0e80f AC |
2621 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
2622 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0) | |
2623 | { | |
2624 | if (debug_linux_nat) | |
2625 | fprintf_unfiltered (gdb_stdlog, | |
2626 | "WL: Handling extended status 0x%06x\n", | |
2627 | status); | |
3d799a95 | 2628 | if (linux_handle_extended_wait (lp, status, 1)) |
d6b0e80f AC |
2629 | return wait_lwp (lp); |
2630 | } | |
2631 | ||
2632 | return status; | |
2633 | } | |
2634 | ||
2635 | /* Send a SIGSTOP to LP. */ | |
2636 | ||
2637 | static int | |
2638 | stop_callback (struct lwp_info *lp, void *data) | |
2639 | { | |
2640 | if (!lp->stopped && !lp->signalled) | |
2641 | { | |
2642 | int ret; | |
2643 | ||
2644 | if (debug_linux_nat) | |
2645 | { | |
2646 | fprintf_unfiltered (gdb_stdlog, | |
2647 | "SC: kill %s **<SIGSTOP>**\n", | |
2648 | target_pid_to_str (lp->ptid)); | |
2649 | } | |
2650 | errno = 0; | |
2651 | ret = kill_lwp (GET_LWP (lp->ptid), SIGSTOP); | |
2652 | if (debug_linux_nat) | |
2653 | { | |
2654 | fprintf_unfiltered (gdb_stdlog, | |
2655 | "SC: lwp kill %d %s\n", | |
2656 | ret, | |
2657 | errno ? safe_strerror (errno) : "ERRNO-OK"); | |
2658 | } | |
2659 | ||
2660 | lp->signalled = 1; | |
2661 | gdb_assert (lp->status == 0); | |
2662 | } | |
2663 | ||
2664 | return 0; | |
2665 | } | |
2666 | ||
7b50312a PA |
2667 | /* Request a stop on LWP. */ |
2668 | ||
2669 | void | |
2670 | linux_stop_lwp (struct lwp_info *lwp) | |
2671 | { | |
2672 | stop_callback (lwp, NULL); | |
2673 | } | |
2674 | ||
57380f4e | 2675 | /* Return non-zero if LWP PID has a pending SIGINT. */ |
d6b0e80f AC |
2676 | |
2677 | static int | |
57380f4e DJ |
2678 | linux_nat_has_pending_sigint (int pid) |
2679 | { | |
2680 | sigset_t pending, blocked, ignored; | |
57380f4e DJ |
2681 | |
2682 | linux_proc_pending_signals (pid, &pending, &blocked, &ignored); | |
2683 | ||
2684 | if (sigismember (&pending, SIGINT) | |
2685 | && !sigismember (&ignored, SIGINT)) | |
2686 | return 1; | |
2687 | ||
2688 | return 0; | |
2689 | } | |
2690 | ||
2691 | /* Set a flag in LP indicating that we should ignore its next SIGINT. */ | |
2692 | ||
2693 | static int | |
2694 | set_ignore_sigint (struct lwp_info *lp, void *data) | |
d6b0e80f | 2695 | { |
57380f4e DJ |
2696 | /* If a thread has a pending SIGINT, consume it; otherwise, set a |
2697 | flag to consume the next one. */ | |
2698 | if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) | |
2699 | && WSTOPSIG (lp->status) == SIGINT) | |
2700 | lp->status = 0; | |
2701 | else | |
2702 | lp->ignore_sigint = 1; | |
2703 | ||
2704 | return 0; | |
2705 | } | |
2706 | ||
2707 | /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. | |
2708 | This function is called after we know the LWP has stopped; if the LWP | |
2709 | stopped before the expected SIGINT was delivered, then it will never have | |
2710 | arrived. Also, if the signal was delivered to a shared queue and consumed | |
2711 | by a different thread, it will never be delivered to this LWP. */ | |
d6b0e80f | 2712 | |
57380f4e DJ |
2713 | static void |
2714 | maybe_clear_ignore_sigint (struct lwp_info *lp) | |
2715 | { | |
2716 | if (!lp->ignore_sigint) | |
2717 | return; | |
2718 | ||
2719 | if (!linux_nat_has_pending_sigint (GET_LWP (lp->ptid))) | |
2720 | { | |
2721 | if (debug_linux_nat) | |
2722 | fprintf_unfiltered (gdb_stdlog, | |
2723 | "MCIS: Clearing bogus flag for %s\n", | |
2724 | target_pid_to_str (lp->ptid)); | |
2725 | lp->ignore_sigint = 0; | |
2726 | } | |
2727 | } | |
2728 | ||
ebec9a0f PA |
2729 | /* Fetch the possible triggered data watchpoint info and store it in |
2730 | LP. | |
2731 | ||
2732 | On some archs, like x86, that use debug registers to set | |
2733 | watchpoints, it's possible that the way to know which watched | |
2734 | address trapped, is to check the register that is used to select | |
2735 | which address to watch. Problem is, between setting the watchpoint | |
2736 | and reading back which data address trapped, the user may change | |
2737 | the set of watchpoints, and, as a consequence, GDB changes the | |
2738 | debug registers in the inferior. To avoid reading back a stale | |
2739 | stopped-data-address when that happens, we cache in LP the fact | |
2740 | that a watchpoint trapped, and the corresponding data address, as | |
2741 | soon as we see LP stop with a SIGTRAP. If GDB changes the debug | |
2742 | registers meanwhile, we have the cached data we can rely on. */ | |
2743 | ||
2744 | static void | |
2745 | save_sigtrap (struct lwp_info *lp) | |
2746 | { | |
2747 | struct cleanup *old_chain; | |
2748 | ||
2749 | if (linux_ops->to_stopped_by_watchpoint == NULL) | |
2750 | { | |
2751 | lp->stopped_by_watchpoint = 0; | |
2752 | return; | |
2753 | } | |
2754 | ||
2755 | old_chain = save_inferior_ptid (); | |
2756 | inferior_ptid = lp->ptid; | |
2757 | ||
2758 | lp->stopped_by_watchpoint = linux_ops->to_stopped_by_watchpoint (); | |
2759 | ||
2760 | if (lp->stopped_by_watchpoint) | |
2761 | { | |
2762 | if (linux_ops->to_stopped_data_address != NULL) | |
2763 | lp->stopped_data_address_p = | |
2764 | linux_ops->to_stopped_data_address (¤t_target, | |
2765 | &lp->stopped_data_address); | |
2766 | else | |
2767 | lp->stopped_data_address_p = 0; | |
2768 | } | |
2769 | ||
2770 | do_cleanups (old_chain); | |
2771 | } | |
2772 | ||
2773 | /* See save_sigtrap. */ | |
2774 | ||
2775 | static int | |
2776 | linux_nat_stopped_by_watchpoint (void) | |
2777 | { | |
2778 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2779 | ||
2780 | gdb_assert (lp != NULL); | |
2781 | ||
2782 | return lp->stopped_by_watchpoint; | |
2783 | } | |
2784 | ||
2785 | static int | |
2786 | linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p) | |
2787 | { | |
2788 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2789 | ||
2790 | gdb_assert (lp != NULL); | |
2791 | ||
2792 | *addr_p = lp->stopped_data_address; | |
2793 | ||
2794 | return lp->stopped_data_address_p; | |
2795 | } | |
2796 | ||
26ab7092 JK |
2797 | /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
2798 | ||
2799 | static int | |
2800 | sigtrap_is_event (int status) | |
2801 | { | |
2802 | return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; | |
2803 | } | |
2804 | ||
2805 | /* SIGTRAP-like events recognizer. */ | |
2806 | ||
2807 | static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event; | |
2808 | ||
00390b84 JK |
2809 | /* Check for SIGTRAP-like events in LP. */ |
2810 | ||
2811 | static int | |
2812 | linux_nat_lp_status_is_event (struct lwp_info *lp) | |
2813 | { | |
2814 | /* We check for lp->waitstatus in addition to lp->status, because we can | |
2815 | have pending process exits recorded in lp->status | |
2816 | and W_EXITCODE(0,0) == 0. We should probably have an additional | |
2817 | lp->status_p flag. */ | |
2818 | ||
2819 | return (lp->waitstatus.kind == TARGET_WAITKIND_IGNORE | |
2820 | && linux_nat_status_is_event (lp->status)); | |
2821 | } | |
2822 | ||
26ab7092 JK |
2823 | /* Set alternative SIGTRAP-like events recognizer. If |
2824 | breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be | |
2825 | applied. */ | |
2826 | ||
2827 | void | |
2828 | linux_nat_set_status_is_event (struct target_ops *t, | |
2829 | int (*status_is_event) (int status)) | |
2830 | { | |
2831 | linux_nat_status_is_event = status_is_event; | |
2832 | } | |
2833 | ||
57380f4e DJ |
2834 | /* Wait until LP is stopped. */ |
2835 | ||
2836 | static int | |
2837 | stop_wait_callback (struct lwp_info *lp, void *data) | |
2838 | { | |
6c95b8df PA |
2839 | struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid)); |
2840 | ||
2841 | /* If this is a vfork parent, bail out, it is not going to report | |
2842 | any SIGSTOP until the vfork is done with. */ | |
2843 | if (inf->vfork_child != NULL) | |
2844 | return 0; | |
2845 | ||
d6b0e80f AC |
2846 | if (!lp->stopped) |
2847 | { | |
2848 | int status; | |
2849 | ||
2850 | status = wait_lwp (lp); | |
2851 | if (status == 0) | |
2852 | return 0; | |
2853 | ||
57380f4e DJ |
2854 | if (lp->ignore_sigint && WIFSTOPPED (status) |
2855 | && WSTOPSIG (status) == SIGINT) | |
d6b0e80f | 2856 | { |
57380f4e | 2857 | lp->ignore_sigint = 0; |
d6b0e80f AC |
2858 | |
2859 | errno = 0; | |
2860 | ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); | |
2861 | if (debug_linux_nat) | |
2862 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
2863 | "PTRACE_CONT %s, 0, 0 (%s) " |
2864 | "(discarding SIGINT)\n", | |
d6b0e80f AC |
2865 | target_pid_to_str (lp->ptid), |
2866 | errno ? safe_strerror (errno) : "OK"); | |
2867 | ||
57380f4e | 2868 | return stop_wait_callback (lp, NULL); |
d6b0e80f AC |
2869 | } |
2870 | ||
57380f4e DJ |
2871 | maybe_clear_ignore_sigint (lp); |
2872 | ||
d6b0e80f AC |
2873 | if (WSTOPSIG (status) != SIGSTOP) |
2874 | { | |
e5ef252a | 2875 | /* The thread was stopped with a signal other than SIGSTOP. */ |
7feb7d06 | 2876 | |
e5ef252a PA |
2877 | save_sigtrap (lp); |
2878 | ||
2879 | if (debug_linux_nat) | |
2880 | fprintf_unfiltered (gdb_stdlog, | |
2881 | "SWC: Pending event %s in %s\n", | |
2882 | status_to_str ((int) status), | |
2883 | target_pid_to_str (lp->ptid)); | |
2884 | ||
2885 | /* Save the sigtrap event. */ | |
2886 | lp->status = status; | |
2887 | gdb_assert (!lp->stopped); | |
2888 | gdb_assert (lp->signalled); | |
2889 | lp->stopped = 1; | |
d6b0e80f AC |
2890 | } |
2891 | else | |
2892 | { | |
2893 | /* We caught the SIGSTOP that we intended to catch, so | |
2894 | there's no SIGSTOP pending. */ | |
e5ef252a PA |
2895 | |
2896 | if (debug_linux_nat) | |
2897 | fprintf_unfiltered (gdb_stdlog, | |
2898 | "SWC: Delayed SIGSTOP caught for %s.\n", | |
2899 | target_pid_to_str (lp->ptid)); | |
2900 | ||
d6b0e80f | 2901 | lp->stopped = 1; |
e5ef252a PA |
2902 | |
2903 | /* Reset SIGNALLED only after the stop_wait_callback call | |
2904 | above as it does gdb_assert on SIGNALLED. */ | |
d6b0e80f AC |
2905 | lp->signalled = 0; |
2906 | } | |
2907 | } | |
2908 | ||
2909 | return 0; | |
2910 | } | |
2911 | ||
d6b0e80f AC |
2912 | /* Return non-zero if LP has a wait status pending. */ |
2913 | ||
2914 | static int | |
2915 | status_callback (struct lwp_info *lp, void *data) | |
2916 | { | |
2917 | /* Only report a pending wait status if we pretend that this has | |
2918 | indeed been resumed. */ | |
ca2163eb PA |
2919 | if (!lp->resumed) |
2920 | return 0; | |
2921 | ||
2922 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
2923 | { | |
2924 | /* A ptrace event, like PTRACE_FORK|VFORK|EXEC, syscall event, | |
766062f6 | 2925 | or a pending process exit. Note that `W_EXITCODE(0,0) == |
ca2163eb PA |
2926 | 0', so a clean process exit can not be stored pending in |
2927 | lp->status, it is indistinguishable from | |
2928 | no-pending-status. */ | |
2929 | return 1; | |
2930 | } | |
2931 | ||
2932 | if (lp->status != 0) | |
2933 | return 1; | |
2934 | ||
2935 | return 0; | |
d6b0e80f AC |
2936 | } |
2937 | ||
2938 | /* Return non-zero if LP isn't stopped. */ | |
2939 | ||
2940 | static int | |
2941 | running_callback (struct lwp_info *lp, void *data) | |
2942 | { | |
25289eb2 PA |
2943 | return (!lp->stopped |
2944 | || ((lp->status != 0 | |
2945 | || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
2946 | && lp->resumed)); | |
d6b0e80f AC |
2947 | } |
2948 | ||
2949 | /* Count the LWP's that have had events. */ | |
2950 | ||
2951 | static int | |
2952 | count_events_callback (struct lwp_info *lp, void *data) | |
2953 | { | |
2954 | int *count = data; | |
2955 | ||
2956 | gdb_assert (count != NULL); | |
2957 | ||
e09490f1 | 2958 | /* Count only resumed LWPs that have a SIGTRAP event pending. */ |
00390b84 | 2959 | if (lp->resumed && linux_nat_lp_status_is_event (lp)) |
d6b0e80f AC |
2960 | (*count)++; |
2961 | ||
2962 | return 0; | |
2963 | } | |
2964 | ||
2965 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
2966 | ||
2967 | static int | |
2968 | select_singlestep_lwp_callback (struct lwp_info *lp, void *data) | |
2969 | { | |
25289eb2 PA |
2970 | if (lp->last_resume_kind == resume_step |
2971 | && lp->status != 0) | |
d6b0e80f AC |
2972 | return 1; |
2973 | else | |
2974 | return 0; | |
2975 | } | |
2976 | ||
2977 | /* Select the Nth LWP that has had a SIGTRAP event. */ | |
2978 | ||
2979 | static int | |
2980 | select_event_lwp_callback (struct lwp_info *lp, void *data) | |
2981 | { | |
2982 | int *selector = data; | |
2983 | ||
2984 | gdb_assert (selector != NULL); | |
2985 | ||
1777feb0 | 2986 | /* Select only resumed LWPs that have a SIGTRAP event pending. */ |
00390b84 | 2987 | if (lp->resumed && linux_nat_lp_status_is_event (lp)) |
d6b0e80f AC |
2988 | if ((*selector)-- == 0) |
2989 | return 1; | |
2990 | ||
2991 | return 0; | |
2992 | } | |
2993 | ||
710151dd PA |
2994 | static int |
2995 | cancel_breakpoint (struct lwp_info *lp) | |
2996 | { | |
2997 | /* Arrange for a breakpoint to be hit again later. We don't keep | |
2998 | the SIGTRAP status and don't forward the SIGTRAP signal to the | |
2999 | LWP. We will handle the current event, eventually we will resume | |
3000 | this LWP, and this breakpoint will trap again. | |
3001 | ||
3002 | If we do not do this, then we run the risk that the user will | |
3003 | delete or disable the breakpoint, but the LWP will have already | |
3004 | tripped on it. */ | |
3005 | ||
515630c5 UW |
3006 | struct regcache *regcache = get_thread_regcache (lp->ptid); |
3007 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
3008 | CORE_ADDR pc; | |
3009 | ||
3010 | pc = regcache_read_pc (regcache) - gdbarch_decr_pc_after_break (gdbarch); | |
6c95b8df | 3011 | if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
710151dd PA |
3012 | { |
3013 | if (debug_linux_nat) | |
3014 | fprintf_unfiltered (gdb_stdlog, | |
3015 | "CB: Push back breakpoint for %s\n", | |
3016 | target_pid_to_str (lp->ptid)); | |
3017 | ||
3018 | /* Back up the PC if necessary. */ | |
515630c5 UW |
3019 | if (gdbarch_decr_pc_after_break (gdbarch)) |
3020 | regcache_write_pc (regcache, pc); | |
3021 | ||
710151dd PA |
3022 | return 1; |
3023 | } | |
3024 | return 0; | |
3025 | } | |
3026 | ||
d6b0e80f AC |
3027 | static int |
3028 | cancel_breakpoints_callback (struct lwp_info *lp, void *data) | |
3029 | { | |
3030 | struct lwp_info *event_lp = data; | |
3031 | ||
3032 | /* Leave the LWP that has been elected to receive a SIGTRAP alone. */ | |
3033 | if (lp == event_lp) | |
3034 | return 0; | |
3035 | ||
3036 | /* If a LWP other than the LWP that we're reporting an event for has | |
3037 | hit a GDB breakpoint (as opposed to some random trap signal), | |
3038 | then just arrange for it to hit it again later. We don't keep | |
3039 | the SIGTRAP status and don't forward the SIGTRAP signal to the | |
3040 | LWP. We will handle the current event, eventually we will resume | |
3041 | all LWPs, and this one will get its breakpoint trap again. | |
3042 | ||
3043 | If we do not do this, then we run the risk that the user will | |
3044 | delete or disable the breakpoint, but the LWP will have already | |
3045 | tripped on it. */ | |
3046 | ||
00390b84 | 3047 | if (linux_nat_lp_status_is_event (lp) |
710151dd PA |
3048 | && cancel_breakpoint (lp)) |
3049 | /* Throw away the SIGTRAP. */ | |
3050 | lp->status = 0; | |
d6b0e80f AC |
3051 | |
3052 | return 0; | |
3053 | } | |
3054 | ||
3055 | /* Select one LWP out of those that have events pending. */ | |
3056 | ||
3057 | static void | |
d90e17a7 | 3058 | select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
d6b0e80f AC |
3059 | { |
3060 | int num_events = 0; | |
3061 | int random_selector; | |
3062 | struct lwp_info *event_lp; | |
3063 | ||
ac264b3b | 3064 | /* Record the wait status for the original LWP. */ |
d6b0e80f AC |
3065 | (*orig_lp)->status = *status; |
3066 | ||
3067 | /* Give preference to any LWP that is being single-stepped. */ | |
d90e17a7 PA |
3068 | event_lp = iterate_over_lwps (filter, |
3069 | select_singlestep_lwp_callback, NULL); | |
d6b0e80f AC |
3070 | if (event_lp != NULL) |
3071 | { | |
3072 | if (debug_linux_nat) | |
3073 | fprintf_unfiltered (gdb_stdlog, | |
3074 | "SEL: Select single-step %s\n", | |
3075 | target_pid_to_str (event_lp->ptid)); | |
3076 | } | |
3077 | else | |
3078 | { | |
3079 | /* No single-stepping LWP. Select one at random, out of those | |
3080 | which have had SIGTRAP events. */ | |
3081 | ||
3082 | /* First see how many SIGTRAP events we have. */ | |
d90e17a7 | 3083 | iterate_over_lwps (filter, count_events_callback, &num_events); |
d6b0e80f AC |
3084 | |
3085 | /* Now randomly pick a LWP out of those that have had a SIGTRAP. */ | |
3086 | random_selector = (int) | |
3087 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
3088 | ||
3089 | if (debug_linux_nat && num_events > 1) | |
3090 | fprintf_unfiltered (gdb_stdlog, | |
3091 | "SEL: Found %d SIGTRAP events, selecting #%d\n", | |
3092 | num_events, random_selector); | |
3093 | ||
d90e17a7 PA |
3094 | event_lp = iterate_over_lwps (filter, |
3095 | select_event_lwp_callback, | |
d6b0e80f AC |
3096 | &random_selector); |
3097 | } | |
3098 | ||
3099 | if (event_lp != NULL) | |
3100 | { | |
3101 | /* Switch the event LWP. */ | |
3102 | *orig_lp = event_lp; | |
3103 | *status = event_lp->status; | |
3104 | } | |
3105 | ||
3106 | /* Flush the wait status for the event LWP. */ | |
3107 | (*orig_lp)->status = 0; | |
3108 | } | |
3109 | ||
3110 | /* Return non-zero if LP has been resumed. */ | |
3111 | ||
3112 | static int | |
3113 | resumed_callback (struct lwp_info *lp, void *data) | |
3114 | { | |
3115 | return lp->resumed; | |
3116 | } | |
3117 | ||
12d9289a PA |
3118 | /* Stop an active thread, verify it still exists, then resume it. If |
3119 | the thread ends up with a pending status, then it is not resumed, | |
3120 | and *DATA (really a pointer to int), is set. */ | |
d6b0e80f AC |
3121 | |
3122 | static int | |
3123 | stop_and_resume_callback (struct lwp_info *lp, void *data) | |
3124 | { | |
12d9289a PA |
3125 | int *new_pending_p = data; |
3126 | ||
25289eb2 | 3127 | if (!lp->stopped) |
d6b0e80f | 3128 | { |
25289eb2 PA |
3129 | ptid_t ptid = lp->ptid; |
3130 | ||
d6b0e80f AC |
3131 | stop_callback (lp, NULL); |
3132 | stop_wait_callback (lp, NULL); | |
25289eb2 PA |
3133 | |
3134 | /* Resume if the lwp still exists, and the core wanted it | |
3135 | running. */ | |
12d9289a PA |
3136 | lp = find_lwp_pid (ptid); |
3137 | if (lp != NULL) | |
25289eb2 | 3138 | { |
12d9289a PA |
3139 | if (lp->last_resume_kind == resume_stop |
3140 | && lp->status == 0) | |
3141 | { | |
3142 | /* The core wanted the LWP to stop. Even if it stopped | |
3143 | cleanly (with SIGSTOP), leave the event pending. */ | |
3144 | if (debug_linux_nat) | |
3145 | fprintf_unfiltered (gdb_stdlog, | |
3146 | "SARC: core wanted LWP %ld stopped " | |
3147 | "(leaving SIGSTOP pending)\n", | |
3148 | GET_LWP (lp->ptid)); | |
3149 | lp->status = W_STOPCODE (SIGSTOP); | |
3150 | } | |
3151 | ||
3152 | if (lp->status == 0) | |
3153 | { | |
3154 | if (debug_linux_nat) | |
3155 | fprintf_unfiltered (gdb_stdlog, | |
3156 | "SARC: re-resuming LWP %ld\n", | |
3157 | GET_LWP (lp->ptid)); | |
e5ef252a | 3158 | resume_lwp (lp, lp->step, GDB_SIGNAL_0); |
12d9289a PA |
3159 | } |
3160 | else | |
3161 | { | |
3162 | if (debug_linux_nat) | |
3163 | fprintf_unfiltered (gdb_stdlog, | |
3164 | "SARC: not re-resuming LWP %ld " | |
3165 | "(has pending)\n", | |
3166 | GET_LWP (lp->ptid)); | |
3167 | if (new_pending_p) | |
3168 | *new_pending_p = 1; | |
3169 | } | |
25289eb2 | 3170 | } |
d6b0e80f AC |
3171 | } |
3172 | return 0; | |
3173 | } | |
3174 | ||
02f3fc28 | 3175 | /* Check if we should go on and pass this event to common code. |
12d9289a PA |
3176 | Return the affected lwp if we are, or NULL otherwise. If we stop |
3177 | all lwps temporarily, we may end up with new pending events in some | |
3178 | other lwp. In that case set *NEW_PENDING_P to true. */ | |
3179 | ||
02f3fc28 | 3180 | static struct lwp_info * |
0e5bf2a8 | 3181 | linux_nat_filter_event (int lwpid, int status, int *new_pending_p) |
02f3fc28 PA |
3182 | { |
3183 | struct lwp_info *lp; | |
3184 | ||
12d9289a PA |
3185 | *new_pending_p = 0; |
3186 | ||
02f3fc28 PA |
3187 | lp = find_lwp_pid (pid_to_ptid (lwpid)); |
3188 | ||
3189 | /* Check for stop events reported by a process we didn't already | |
3190 | know about - anything not already in our LWP list. | |
3191 | ||
3192 | If we're expecting to receive stopped processes after | |
3193 | fork, vfork, and clone events, then we'll just add the | |
3194 | new one to our list and go back to waiting for the event | |
3195 | to be reported - the stopped process might be returned | |
0e5bf2a8 PA |
3196 | from waitpid before or after the event is. |
3197 | ||
3198 | But note the case of a non-leader thread exec'ing after the | |
3199 | leader having exited, and gone from our lists. The non-leader | |
3200 | thread changes its tid to the tgid. */ | |
3201 | ||
3202 | if (WIFSTOPPED (status) && lp == NULL | |
3203 | && (WSTOPSIG (status) == SIGTRAP && status >> 16 == PTRACE_EVENT_EXEC)) | |
3204 | { | |
3205 | /* A multi-thread exec after we had seen the leader exiting. */ | |
3206 | if (debug_linux_nat) | |
3207 | fprintf_unfiltered (gdb_stdlog, | |
3208 | "LLW: Re-adding thread group leader LWP %d.\n", | |
3209 | lwpid); | |
3210 | ||
3211 | lp = add_lwp (BUILD_LWP (lwpid, lwpid)); | |
3212 | lp->stopped = 1; | |
3213 | lp->resumed = 1; | |
3214 | add_thread (lp->ptid); | |
3215 | } | |
3216 | ||
02f3fc28 PA |
3217 | if (WIFSTOPPED (status) && !lp) |
3218 | { | |
84636d28 | 3219 | add_to_pid_list (&stopped_pids, lwpid, status); |
02f3fc28 PA |
3220 | return NULL; |
3221 | } | |
3222 | ||
3223 | /* Make sure we don't report an event for the exit of an LWP not in | |
1777feb0 | 3224 | our list, i.e. not part of the current process. This can happen |
fd62cb89 | 3225 | if we detach from a program we originally forked and then it |
02f3fc28 PA |
3226 | exits. */ |
3227 | if (!WIFSTOPPED (status) && !lp) | |
3228 | return NULL; | |
3229 | ||
ca2163eb PA |
3230 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
3231 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
3232 | { | |
3233 | /* No longer need the sysgood bit. The ptrace event ends up | |
3234 | recorded in lp->waitstatus if we care for it. We can carry | |
3235 | on handling the event like a regular SIGTRAP from here | |
3236 | on. */ | |
3237 | status = W_STOPCODE (SIGTRAP); | |
3238 | if (linux_handle_syscall_trap (lp, 0)) | |
3239 | return NULL; | |
3240 | } | |
02f3fc28 | 3241 | |
ca2163eb PA |
3242 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
3243 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0) | |
02f3fc28 PA |
3244 | { |
3245 | if (debug_linux_nat) | |
3246 | fprintf_unfiltered (gdb_stdlog, | |
3247 | "LLW: Handling extended status 0x%06x\n", | |
3248 | status); | |
3249 | if (linux_handle_extended_wait (lp, status, 0)) | |
3250 | return NULL; | |
3251 | } | |
3252 | ||
26ab7092 | 3253 | if (linux_nat_status_is_event (status)) |
da559b09 | 3254 | save_sigtrap (lp); |
ca2163eb | 3255 | |
02f3fc28 | 3256 | /* Check if the thread has exited. */ |
d90e17a7 PA |
3257 | if ((WIFEXITED (status) || WIFSIGNALED (status)) |
3258 | && num_lwps (GET_PID (lp->ptid)) > 1) | |
02f3fc28 | 3259 | { |
9db03742 JB |
3260 | /* If this is the main thread, we must stop all threads and verify |
3261 | if they are still alive. This is because in the nptl thread model | |
3262 | on Linux 2.4, there is no signal issued for exiting LWPs | |
02f3fc28 PA |
3263 | other than the main thread. We only get the main thread exit |
3264 | signal once all child threads have already exited. If we | |
3265 | stop all the threads and use the stop_wait_callback to check | |
3266 | if they have exited we can determine whether this signal | |
3267 | should be ignored or whether it means the end of the debugged | |
3268 | application, regardless of which threading model is being | |
5d3b6af6 | 3269 | used. */ |
02f3fc28 PA |
3270 | if (GET_PID (lp->ptid) == GET_LWP (lp->ptid)) |
3271 | { | |
3272 | lp->stopped = 1; | |
d90e17a7 | 3273 | iterate_over_lwps (pid_to_ptid (GET_PID (lp->ptid)), |
12d9289a | 3274 | stop_and_resume_callback, new_pending_p); |
02f3fc28 PA |
3275 | } |
3276 | ||
3277 | if (debug_linux_nat) | |
3278 | fprintf_unfiltered (gdb_stdlog, | |
3279 | "LLW: %s exited.\n", | |
3280 | target_pid_to_str (lp->ptid)); | |
3281 | ||
d90e17a7 | 3282 | if (num_lwps (GET_PID (lp->ptid)) > 1) |
9db03742 JB |
3283 | { |
3284 | /* If there is at least one more LWP, then the exit signal | |
3285 | was not the end of the debugged application and should be | |
3286 | ignored. */ | |
3287 | exit_lwp (lp); | |
3288 | return NULL; | |
3289 | } | |
02f3fc28 PA |
3290 | } |
3291 | ||
3292 | /* Check if the current LWP has previously exited. In the nptl | |
3293 | thread model, LWPs other than the main thread do not issue | |
3294 | signals when they exit so we must check whenever the thread has | |
3295 | stopped. A similar check is made in stop_wait_callback(). */ | |
d90e17a7 | 3296 | if (num_lwps (GET_PID (lp->ptid)) > 1 && !linux_thread_alive (lp->ptid)) |
02f3fc28 | 3297 | { |
d90e17a7 PA |
3298 | ptid_t ptid = pid_to_ptid (GET_PID (lp->ptid)); |
3299 | ||
02f3fc28 PA |
3300 | if (debug_linux_nat) |
3301 | fprintf_unfiltered (gdb_stdlog, | |
3302 | "LLW: %s exited.\n", | |
3303 | target_pid_to_str (lp->ptid)); | |
3304 | ||
3305 | exit_lwp (lp); | |
3306 | ||
3307 | /* Make sure there is at least one thread running. */ | |
d90e17a7 | 3308 | gdb_assert (iterate_over_lwps (ptid, running_callback, NULL)); |
02f3fc28 PA |
3309 | |
3310 | /* Discard the event. */ | |
3311 | return NULL; | |
3312 | } | |
3313 | ||
3314 | /* Make sure we don't report a SIGSTOP that we sent ourselves in | |
3315 | an attempt to stop an LWP. */ | |
3316 | if (lp->signalled | |
3317 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) | |
3318 | { | |
3319 | if (debug_linux_nat) | |
3320 | fprintf_unfiltered (gdb_stdlog, | |
3321 | "LLW: Delayed SIGSTOP caught for %s.\n", | |
3322 | target_pid_to_str (lp->ptid)); | |
3323 | ||
02f3fc28 PA |
3324 | lp->signalled = 0; |
3325 | ||
25289eb2 PA |
3326 | if (lp->last_resume_kind != resume_stop) |
3327 | { | |
3328 | /* This is a delayed SIGSTOP. */ | |
02f3fc28 | 3329 | |
25289eb2 PA |
3330 | registers_changed (); |
3331 | ||
7b50312a PA |
3332 | if (linux_nat_prepare_to_resume != NULL) |
3333 | linux_nat_prepare_to_resume (lp); | |
25289eb2 | 3334 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
a493e3e2 | 3335 | lp->step, GDB_SIGNAL_0); |
25289eb2 PA |
3336 | if (debug_linux_nat) |
3337 | fprintf_unfiltered (gdb_stdlog, | |
3338 | "LLW: %s %s, 0, 0 (discard SIGSTOP)\n", | |
3339 | lp->step ? | |
3340 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3341 | target_pid_to_str (lp->ptid)); | |
02f3fc28 | 3342 | |
25289eb2 PA |
3343 | lp->stopped = 0; |
3344 | gdb_assert (lp->resumed); | |
02f3fc28 | 3345 | |
25289eb2 PA |
3346 | /* Discard the event. */ |
3347 | return NULL; | |
3348 | } | |
02f3fc28 PA |
3349 | } |
3350 | ||
57380f4e DJ |
3351 | /* Make sure we don't report a SIGINT that we have already displayed |
3352 | for another thread. */ | |
3353 | if (lp->ignore_sigint | |
3354 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) | |
3355 | { | |
3356 | if (debug_linux_nat) | |
3357 | fprintf_unfiltered (gdb_stdlog, | |
3358 | "LLW: Delayed SIGINT caught for %s.\n", | |
3359 | target_pid_to_str (lp->ptid)); | |
3360 | ||
3361 | /* This is a delayed SIGINT. */ | |
3362 | lp->ignore_sigint = 0; | |
3363 | ||
3364 | registers_changed (); | |
7b50312a PA |
3365 | if (linux_nat_prepare_to_resume != NULL) |
3366 | linux_nat_prepare_to_resume (lp); | |
28439f5e | 3367 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
a493e3e2 | 3368 | lp->step, GDB_SIGNAL_0); |
57380f4e DJ |
3369 | if (debug_linux_nat) |
3370 | fprintf_unfiltered (gdb_stdlog, | |
3371 | "LLW: %s %s, 0, 0 (discard SIGINT)\n", | |
3372 | lp->step ? | |
3373 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3374 | target_pid_to_str (lp->ptid)); | |
3375 | ||
3376 | lp->stopped = 0; | |
3377 | gdb_assert (lp->resumed); | |
3378 | ||
3379 | /* Discard the event. */ | |
3380 | return NULL; | |
3381 | } | |
3382 | ||
02f3fc28 PA |
3383 | /* An interesting event. */ |
3384 | gdb_assert (lp); | |
ca2163eb | 3385 | lp->status = status; |
02f3fc28 PA |
3386 | return lp; |
3387 | } | |
3388 | ||
0e5bf2a8 PA |
3389 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
3390 | their exits until all other threads in the group have exited. */ | |
3391 | ||
3392 | static void | |
3393 | check_zombie_leaders (void) | |
3394 | { | |
3395 | struct inferior *inf; | |
3396 | ||
3397 | ALL_INFERIORS (inf) | |
3398 | { | |
3399 | struct lwp_info *leader_lp; | |
3400 | ||
3401 | if (inf->pid == 0) | |
3402 | continue; | |
3403 | ||
3404 | leader_lp = find_lwp_pid (pid_to_ptid (inf->pid)); | |
3405 | if (leader_lp != NULL | |
3406 | /* Check if there are other threads in the group, as we may | |
3407 | have raced with the inferior simply exiting. */ | |
3408 | && num_lwps (inf->pid) > 1 | |
5f572dec | 3409 | && linux_proc_pid_is_zombie (inf->pid)) |
0e5bf2a8 PA |
3410 | { |
3411 | if (debug_linux_nat) | |
3412 | fprintf_unfiltered (gdb_stdlog, | |
3413 | "CZL: Thread group leader %d zombie " | |
3414 | "(it exited, or another thread execd).\n", | |
3415 | inf->pid); | |
3416 | ||
3417 | /* A leader zombie can mean one of two things: | |
3418 | ||
3419 | - It exited, and there's an exit status pending | |
3420 | available, or only the leader exited (not the whole | |
3421 | program). In the latter case, we can't waitpid the | |
3422 | leader's exit status until all other threads are gone. | |
3423 | ||
3424 | - There are 3 or more threads in the group, and a thread | |
3425 | other than the leader exec'd. On an exec, the Linux | |
3426 | kernel destroys all other threads (except the execing | |
3427 | one) in the thread group, and resets the execing thread's | |
3428 | tid to the tgid. No exit notification is sent for the | |
3429 | execing thread -- from the ptracer's perspective, it | |
3430 | appears as though the execing thread just vanishes. | |
3431 | Until we reap all other threads except the leader and the | |
3432 | execing thread, the leader will be zombie, and the | |
3433 | execing thread will be in `D (disc sleep)'. As soon as | |
3434 | all other threads are reaped, the execing thread changes | |
3435 | it's tid to the tgid, and the previous (zombie) leader | |
3436 | vanishes, giving place to the "new" leader. We could try | |
3437 | distinguishing the exit and exec cases, by waiting once | |
3438 | more, and seeing if something comes out, but it doesn't | |
3439 | sound useful. The previous leader _does_ go away, and | |
3440 | we'll re-add the new one once we see the exec event | |
3441 | (which is just the same as what would happen if the | |
3442 | previous leader did exit voluntarily before some other | |
3443 | thread execs). */ | |
3444 | ||
3445 | if (debug_linux_nat) | |
3446 | fprintf_unfiltered (gdb_stdlog, | |
3447 | "CZL: Thread group leader %d vanished.\n", | |
3448 | inf->pid); | |
3449 | exit_lwp (leader_lp); | |
3450 | } | |
3451 | } | |
3452 | } | |
3453 | ||
d6b0e80f | 3454 | static ptid_t |
7feb7d06 | 3455 | linux_nat_wait_1 (struct target_ops *ops, |
47608cb1 PA |
3456 | ptid_t ptid, struct target_waitstatus *ourstatus, |
3457 | int target_options) | |
d6b0e80f | 3458 | { |
7feb7d06 | 3459 | static sigset_t prev_mask; |
4b60df3d | 3460 | enum resume_kind last_resume_kind; |
12d9289a | 3461 | struct lwp_info *lp; |
12d9289a | 3462 | int status; |
d6b0e80f | 3463 | |
01124a23 | 3464 | if (debug_linux_nat) |
b84876c2 PA |
3465 | fprintf_unfiltered (gdb_stdlog, "LLW: enter\n"); |
3466 | ||
f973ed9c DJ |
3467 | /* The first time we get here after starting a new inferior, we may |
3468 | not have added it to the LWP list yet - this is the earliest | |
3469 | moment at which we know its PID. */ | |
d90e17a7 | 3470 | if (ptid_is_pid (inferior_ptid)) |
f973ed9c | 3471 | { |
27c9d204 PA |
3472 | /* Upgrade the main thread's ptid. */ |
3473 | thread_change_ptid (inferior_ptid, | |
3474 | BUILD_LWP (GET_PID (inferior_ptid), | |
3475 | GET_PID (inferior_ptid))); | |
3476 | ||
26cb8b7c | 3477 | lp = add_initial_lwp (inferior_ptid); |
f973ed9c DJ |
3478 | lp->resumed = 1; |
3479 | } | |
3480 | ||
7feb7d06 PA |
3481 | /* Make sure SIGCHLD is blocked. */ |
3482 | block_child_signals (&prev_mask); | |
d6b0e80f AC |
3483 | |
3484 | retry: | |
d90e17a7 PA |
3485 | lp = NULL; |
3486 | status = 0; | |
d6b0e80f AC |
3487 | |
3488 | /* First check if there is a LWP with a wait status pending. */ | |
0e5bf2a8 | 3489 | if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) |
d6b0e80f | 3490 | { |
0e5bf2a8 | 3491 | /* Any LWP in the PTID group that's been resumed will do. */ |
d90e17a7 | 3492 | lp = iterate_over_lwps (ptid, status_callback, NULL); |
d6b0e80f AC |
3493 | if (lp) |
3494 | { | |
ca2163eb | 3495 | if (debug_linux_nat && lp->status) |
d6b0e80f AC |
3496 | fprintf_unfiltered (gdb_stdlog, |
3497 | "LLW: Using pending wait status %s for %s.\n", | |
ca2163eb | 3498 | status_to_str (lp->status), |
d6b0e80f AC |
3499 | target_pid_to_str (lp->ptid)); |
3500 | } | |
d6b0e80f AC |
3501 | } |
3502 | else if (is_lwp (ptid)) | |
3503 | { | |
3504 | if (debug_linux_nat) | |
3505 | fprintf_unfiltered (gdb_stdlog, | |
3506 | "LLW: Waiting for specific LWP %s.\n", | |
3507 | target_pid_to_str (ptid)); | |
3508 | ||
3509 | /* We have a specific LWP to check. */ | |
3510 | lp = find_lwp_pid (ptid); | |
3511 | gdb_assert (lp); | |
d6b0e80f | 3512 | |
ca2163eb | 3513 | if (debug_linux_nat && lp->status) |
d6b0e80f AC |
3514 | fprintf_unfiltered (gdb_stdlog, |
3515 | "LLW: Using pending wait status %s for %s.\n", | |
ca2163eb | 3516 | status_to_str (lp->status), |
d6b0e80f AC |
3517 | target_pid_to_str (lp->ptid)); |
3518 | ||
d90e17a7 PA |
3519 | /* We check for lp->waitstatus in addition to lp->status, |
3520 | because we can have pending process exits recorded in | |
3521 | lp->status and W_EXITCODE(0,0) == 0. We should probably have | |
3522 | an additional lp->status_p flag. */ | |
ca2163eb | 3523 | if (lp->status == 0 && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) |
d90e17a7 | 3524 | lp = NULL; |
d6b0e80f AC |
3525 | } |
3526 | ||
b84876c2 PA |
3527 | if (!target_can_async_p ()) |
3528 | { | |
3529 | /* Causes SIGINT to be passed on to the attached process. */ | |
3530 | set_sigint_trap (); | |
b84876c2 | 3531 | } |
d6b0e80f | 3532 | |
0e5bf2a8 | 3533 | /* But if we don't find a pending event, we'll have to wait. */ |
7feb7d06 | 3534 | |
d90e17a7 | 3535 | while (lp == NULL) |
d6b0e80f AC |
3536 | { |
3537 | pid_t lwpid; | |
3538 | ||
0e5bf2a8 PA |
3539 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
3540 | quirks: | |
3541 | ||
3542 | - If the thread group leader exits while other threads in the | |
3543 | thread group still exist, waitpid(TGID, ...) hangs. That | |
3544 | waitpid won't return an exit status until the other threads | |
3545 | in the group are reapped. | |
3546 | ||
3547 | - When a non-leader thread execs, that thread just vanishes | |
3548 | without reporting an exit (so we'd hang if we waited for it | |
3549 | explicitly in that case). The exec event is reported to | |
3550 | the TGID pid. */ | |
3551 | ||
3552 | errno = 0; | |
3553 | lwpid = my_waitpid (-1, &status, __WCLONE | WNOHANG); | |
3554 | if (lwpid == 0 || (lwpid == -1 && errno == ECHILD)) | |
3555 | lwpid = my_waitpid (-1, &status, WNOHANG); | |
3556 | ||
3557 | if (debug_linux_nat) | |
3558 | fprintf_unfiltered (gdb_stdlog, | |
3559 | "LNW: waitpid(-1, ...) returned %d, %s\n", | |
3560 | lwpid, errno ? safe_strerror (errno) : "ERRNO-OK"); | |
b84876c2 | 3561 | |
d6b0e80f AC |
3562 | if (lwpid > 0) |
3563 | { | |
12d9289a PA |
3564 | /* If this is true, then we paused LWPs momentarily, and may |
3565 | now have pending events to handle. */ | |
3566 | int new_pending; | |
3567 | ||
d6b0e80f AC |
3568 | if (debug_linux_nat) |
3569 | { | |
3570 | fprintf_unfiltered (gdb_stdlog, | |
3571 | "LLW: waitpid %ld received %s\n", | |
3572 | (long) lwpid, status_to_str (status)); | |
3573 | } | |
3574 | ||
0e5bf2a8 | 3575 | lp = linux_nat_filter_event (lwpid, status, &new_pending); |
d90e17a7 | 3576 | |
33355866 JK |
3577 | /* STATUS is now no longer valid, use LP->STATUS instead. */ |
3578 | status = 0; | |
3579 | ||
0e5bf2a8 | 3580 | if (lp && !ptid_match (lp->ptid, ptid)) |
d6b0e80f | 3581 | { |
e3e9f5a2 PA |
3582 | gdb_assert (lp->resumed); |
3583 | ||
d90e17a7 | 3584 | if (debug_linux_nat) |
3e43a32a MS |
3585 | fprintf (stderr, |
3586 | "LWP %ld got an event %06x, leaving pending.\n", | |
33355866 | 3587 | ptid_get_lwp (lp->ptid), lp->status); |
d90e17a7 | 3588 | |
ca2163eb | 3589 | if (WIFSTOPPED (lp->status)) |
d90e17a7 | 3590 | { |
ca2163eb | 3591 | if (WSTOPSIG (lp->status) != SIGSTOP) |
d90e17a7 | 3592 | { |
e3e9f5a2 PA |
3593 | /* Cancel breakpoint hits. The breakpoint may |
3594 | be removed before we fetch events from this | |
3595 | process to report to the core. It is best | |
3596 | not to assume the moribund breakpoints | |
3597 | heuristic always handles these cases --- it | |
3598 | could be too many events go through to the | |
3599 | core before this one is handled. All-stop | |
3600 | always cancels breakpoint hits in all | |
3601 | threads. */ | |
3602 | if (non_stop | |
00390b84 | 3603 | && linux_nat_lp_status_is_event (lp) |
e3e9f5a2 PA |
3604 | && cancel_breakpoint (lp)) |
3605 | { | |
3606 | /* Throw away the SIGTRAP. */ | |
3607 | lp->status = 0; | |
3608 | ||
3609 | if (debug_linux_nat) | |
3610 | fprintf (stderr, | |
3e43a32a MS |
3611 | "LLW: LWP %ld hit a breakpoint while" |
3612 | " waiting for another process;" | |
3613 | " cancelled it\n", | |
e3e9f5a2 PA |
3614 | ptid_get_lwp (lp->ptid)); |
3615 | } | |
3616 | lp->stopped = 1; | |
d90e17a7 PA |
3617 | } |
3618 | else | |
3619 | { | |
3620 | lp->stopped = 1; | |
3621 | lp->signalled = 0; | |
3622 | } | |
3623 | } | |
33355866 | 3624 | else if (WIFEXITED (lp->status) || WIFSIGNALED (lp->status)) |
d90e17a7 PA |
3625 | { |
3626 | if (debug_linux_nat) | |
3e43a32a MS |
3627 | fprintf (stderr, |
3628 | "Process %ld exited while stopping LWPs\n", | |
d90e17a7 PA |
3629 | ptid_get_lwp (lp->ptid)); |
3630 | ||
3631 | /* This was the last lwp in the process. Since | |
3632 | events are serialized to GDB core, and we can't | |
3633 | report this one right now, but GDB core and the | |
3634 | other target layers will want to be notified | |
3635 | about the exit code/signal, leave the status | |
3636 | pending for the next time we're able to report | |
3637 | it. */ | |
d90e17a7 PA |
3638 | |
3639 | /* Prevent trying to stop this thread again. We'll | |
3640 | never try to resume it because it has a pending | |
3641 | status. */ | |
3642 | lp->stopped = 1; | |
3643 | ||
3644 | /* Dead LWP's aren't expected to reported a pending | |
3645 | sigstop. */ | |
3646 | lp->signalled = 0; | |
3647 | ||
3648 | /* Store the pending event in the waitstatus as | |
3649 | well, because W_EXITCODE(0,0) == 0. */ | |
ca2163eb | 3650 | store_waitstatus (&lp->waitstatus, lp->status); |
d90e17a7 PA |
3651 | } |
3652 | ||
3653 | /* Keep looking. */ | |
3654 | lp = NULL; | |
d6b0e80f AC |
3655 | } |
3656 | ||
0e5bf2a8 | 3657 | if (new_pending) |
d90e17a7 | 3658 | { |
0e5bf2a8 PA |
3659 | /* Some LWP now has a pending event. Go all the way |
3660 | back to check it. */ | |
3661 | goto retry; | |
3662 | } | |
12d9289a | 3663 | |
0e5bf2a8 PA |
3664 | if (lp) |
3665 | { | |
3666 | /* We got an event to report to the core. */ | |
3667 | break; | |
d90e17a7 | 3668 | } |
0e5bf2a8 PA |
3669 | |
3670 | /* Retry until nothing comes out of waitpid. A single | |
3671 | SIGCHLD can indicate more than one child stopped. */ | |
3672 | continue; | |
d6b0e80f AC |
3673 | } |
3674 | ||
0e5bf2a8 PA |
3675 | /* Check for zombie thread group leaders. Those can't be reaped |
3676 | until all other threads in the thread group are. */ | |
3677 | check_zombie_leaders (); | |
d6b0e80f | 3678 | |
0e5bf2a8 PA |
3679 | /* If there are no resumed children left, bail. We'd be stuck |
3680 | forever in the sigsuspend call below otherwise. */ | |
3681 | if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL) | |
3682 | { | |
3683 | if (debug_linux_nat) | |
3684 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n"); | |
b84876c2 | 3685 | |
0e5bf2a8 | 3686 | ourstatus->kind = TARGET_WAITKIND_NO_RESUMED; |
b84876c2 | 3687 | |
0e5bf2a8 PA |
3688 | if (!target_can_async_p ()) |
3689 | clear_sigint_trap (); | |
b84876c2 | 3690 | |
0e5bf2a8 PA |
3691 | restore_child_signals_mask (&prev_mask); |
3692 | return minus_one_ptid; | |
d6b0e80f | 3693 | } |
28736962 | 3694 | |
0e5bf2a8 PA |
3695 | /* No interesting event to report to the core. */ |
3696 | ||
3697 | if (target_options & TARGET_WNOHANG) | |
3698 | { | |
01124a23 | 3699 | if (debug_linux_nat) |
28736962 PA |
3700 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n"); |
3701 | ||
0e5bf2a8 | 3702 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
28736962 PA |
3703 | restore_child_signals_mask (&prev_mask); |
3704 | return minus_one_ptid; | |
3705 | } | |
d6b0e80f AC |
3706 | |
3707 | /* We shouldn't end up here unless we want to try again. */ | |
d90e17a7 | 3708 | gdb_assert (lp == NULL); |
0e5bf2a8 PA |
3709 | |
3710 | /* Block until we get an event reported with SIGCHLD. */ | |
3711 | sigsuspend (&suspend_mask); | |
d6b0e80f AC |
3712 | } |
3713 | ||
b84876c2 | 3714 | if (!target_can_async_p ()) |
d26b5354 | 3715 | clear_sigint_trap (); |
d6b0e80f AC |
3716 | |
3717 | gdb_assert (lp); | |
3718 | ||
ca2163eb PA |
3719 | status = lp->status; |
3720 | lp->status = 0; | |
3721 | ||
d6b0e80f AC |
3722 | /* Don't report signals that GDB isn't interested in, such as |
3723 | signals that are neither printed nor stopped upon. Stopping all | |
3724 | threads can be a bit time-consuming so if we want decent | |
3725 | performance with heavily multi-threaded programs, especially when | |
3726 | they're using a high frequency timer, we'd better avoid it if we | |
3727 | can. */ | |
3728 | ||
3729 | if (WIFSTOPPED (status)) | |
3730 | { | |
2ea28649 | 3731 | enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status)); |
d6b0e80f | 3732 | |
2455069d UW |
3733 | /* When using hardware single-step, we need to report every signal. |
3734 | Otherwise, signals in pass_mask may be short-circuited. */ | |
d539ed7e | 3735 | if (!lp->step |
2455069d | 3736 | && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status))) |
d6b0e80f AC |
3737 | { |
3738 | /* FIMXE: kettenis/2001-06-06: Should we resume all threads | |
3739 | here? It is not clear we should. GDB may not expect | |
3740 | other threads to run. On the other hand, not resuming | |
3741 | newly attached threads may cause an unwanted delay in | |
3742 | getting them running. */ | |
3743 | registers_changed (); | |
7b50312a PA |
3744 | if (linux_nat_prepare_to_resume != NULL) |
3745 | linux_nat_prepare_to_resume (lp); | |
28439f5e | 3746 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
10d6c8cd | 3747 | lp->step, signo); |
d6b0e80f AC |
3748 | if (debug_linux_nat) |
3749 | fprintf_unfiltered (gdb_stdlog, | |
3750 | "LLW: %s %s, %s (preempt 'handle')\n", | |
3751 | lp->step ? | |
3752 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3753 | target_pid_to_str (lp->ptid), | |
a493e3e2 | 3754 | (signo != GDB_SIGNAL_0 |
2ea28649 | 3755 | ? strsignal (gdb_signal_to_host (signo)) |
423ec54c | 3756 | : "0")); |
d6b0e80f | 3757 | lp->stopped = 0; |
d6b0e80f AC |
3758 | goto retry; |
3759 | } | |
3760 | ||
1ad15515 | 3761 | if (!non_stop) |
d6b0e80f | 3762 | { |
1ad15515 PA |
3763 | /* Only do the below in all-stop, as we currently use SIGINT |
3764 | to implement target_stop (see linux_nat_stop) in | |
3765 | non-stop. */ | |
a493e3e2 | 3766 | if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0) |
1ad15515 PA |
3767 | { |
3768 | /* If ^C/BREAK is typed at the tty/console, SIGINT gets | |
3769 | forwarded to the entire process group, that is, all LWPs | |
3770 | will receive it - unless they're using CLONE_THREAD to | |
3771 | share signals. Since we only want to report it once, we | |
3772 | mark it as ignored for all LWPs except this one. */ | |
d90e17a7 PA |
3773 | iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid)), |
3774 | set_ignore_sigint, NULL); | |
1ad15515 PA |
3775 | lp->ignore_sigint = 0; |
3776 | } | |
3777 | else | |
3778 | maybe_clear_ignore_sigint (lp); | |
d6b0e80f AC |
3779 | } |
3780 | } | |
3781 | ||
3782 | /* This LWP is stopped now. */ | |
3783 | lp->stopped = 1; | |
3784 | ||
3785 | if (debug_linux_nat) | |
3786 | fprintf_unfiltered (gdb_stdlog, "LLW: Candidate event %s in %s.\n", | |
3787 | status_to_str (status), target_pid_to_str (lp->ptid)); | |
3788 | ||
4c28f408 PA |
3789 | if (!non_stop) |
3790 | { | |
3791 | /* Now stop all other LWP's ... */ | |
d90e17a7 | 3792 | iterate_over_lwps (minus_one_ptid, stop_callback, NULL); |
4c28f408 PA |
3793 | |
3794 | /* ... and wait until all of them have reported back that | |
3795 | they're no longer running. */ | |
d90e17a7 | 3796 | iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL); |
4c28f408 PA |
3797 | |
3798 | /* If we're not waiting for a specific LWP, choose an event LWP | |
3799 | from among those that have had events. Giving equal priority | |
3800 | to all LWPs that have had events helps prevent | |
3801 | starvation. */ | |
0e5bf2a8 | 3802 | if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) |
d90e17a7 | 3803 | select_event_lwp (ptid, &lp, &status); |
d6b0e80f | 3804 | |
e3e9f5a2 PA |
3805 | /* Now that we've selected our final event LWP, cancel any |
3806 | breakpoints in other LWPs that have hit a GDB breakpoint. | |
3807 | See the comment in cancel_breakpoints_callback to find out | |
3808 | why. */ | |
3809 | iterate_over_lwps (minus_one_ptid, cancel_breakpoints_callback, lp); | |
3810 | ||
4b60df3d PA |
3811 | /* We'll need this to determine whether to report a SIGSTOP as |
3812 | TARGET_WAITKIND_0. Need to take a copy because | |
3813 | resume_clear_callback clears it. */ | |
3814 | last_resume_kind = lp->last_resume_kind; | |
3815 | ||
e3e9f5a2 PA |
3816 | /* In all-stop, from the core's perspective, all LWPs are now |
3817 | stopped until a new resume action is sent over. */ | |
3818 | iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL); | |
3819 | } | |
3820 | else | |
25289eb2 | 3821 | { |
4b60df3d PA |
3822 | /* See above. */ |
3823 | last_resume_kind = lp->last_resume_kind; | |
3824 | resume_clear_callback (lp, NULL); | |
25289eb2 | 3825 | } |
d6b0e80f | 3826 | |
26ab7092 | 3827 | if (linux_nat_status_is_event (status)) |
d6b0e80f | 3828 | { |
d6b0e80f AC |
3829 | if (debug_linux_nat) |
3830 | fprintf_unfiltered (gdb_stdlog, | |
4fdebdd0 PA |
3831 | "LLW: trap ptid is %s.\n", |
3832 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 3833 | } |
d6b0e80f AC |
3834 | |
3835 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
3836 | { | |
3837 | *ourstatus = lp->waitstatus; | |
3838 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
3839 | } | |
3840 | else | |
3841 | store_waitstatus (ourstatus, status); | |
3842 | ||
01124a23 | 3843 | if (debug_linux_nat) |
b84876c2 PA |
3844 | fprintf_unfiltered (gdb_stdlog, "LLW: exit\n"); |
3845 | ||
7feb7d06 | 3846 | restore_child_signals_mask (&prev_mask); |
1e225492 | 3847 | |
4b60df3d | 3848 | if (last_resume_kind == resume_stop |
25289eb2 PA |
3849 | && ourstatus->kind == TARGET_WAITKIND_STOPPED |
3850 | && WSTOPSIG (status) == SIGSTOP) | |
3851 | { | |
3852 | /* A thread that has been requested to stop by GDB with | |
3853 | target_stop, and it stopped cleanly, so report as SIG0. The | |
3854 | use of SIGSTOP is an implementation detail. */ | |
a493e3e2 | 3855 | ourstatus->value.sig = GDB_SIGNAL_0; |
25289eb2 PA |
3856 | } |
3857 | ||
1e225492 JK |
3858 | if (ourstatus->kind == TARGET_WAITKIND_EXITED |
3859 | || ourstatus->kind == TARGET_WAITKIND_SIGNALLED) | |
3860 | lp->core = -1; | |
3861 | else | |
2e794194 | 3862 | lp->core = linux_common_core_of_thread (lp->ptid); |
1e225492 | 3863 | |
f973ed9c | 3864 | return lp->ptid; |
d6b0e80f AC |
3865 | } |
3866 | ||
e3e9f5a2 PA |
3867 | /* Resume LWPs that are currently stopped without any pending status |
3868 | to report, but are resumed from the core's perspective. */ | |
3869 | ||
3870 | static int | |
3871 | resume_stopped_resumed_lwps (struct lwp_info *lp, void *data) | |
3872 | { | |
3873 | ptid_t *wait_ptid_p = data; | |
3874 | ||
3875 | if (lp->stopped | |
3876 | && lp->resumed | |
3877 | && lp->status == 0 | |
3878 | && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) | |
3879 | { | |
336060f3 PA |
3880 | struct regcache *regcache = get_thread_regcache (lp->ptid); |
3881 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
3882 | CORE_ADDR pc = regcache_read_pc (regcache); | |
3883 | ||
e3e9f5a2 PA |
3884 | gdb_assert (is_executing (lp->ptid)); |
3885 | ||
3886 | /* Don't bother if there's a breakpoint at PC that we'd hit | |
3887 | immediately, and we're not waiting for this LWP. */ | |
3888 | if (!ptid_match (lp->ptid, *wait_ptid_p)) | |
3889 | { | |
e3e9f5a2 PA |
3890 | if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
3891 | return 0; | |
3892 | } | |
3893 | ||
3894 | if (debug_linux_nat) | |
3895 | fprintf_unfiltered (gdb_stdlog, | |
336060f3 PA |
3896 | "RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n", |
3897 | target_pid_to_str (lp->ptid), | |
3898 | paddress (gdbarch, pc), | |
3899 | lp->step); | |
e3e9f5a2 | 3900 | |
336060f3 | 3901 | registers_changed (); |
7b50312a PA |
3902 | if (linux_nat_prepare_to_resume != NULL) |
3903 | linux_nat_prepare_to_resume (lp); | |
e3e9f5a2 | 3904 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
a493e3e2 | 3905 | lp->step, GDB_SIGNAL_0); |
e3e9f5a2 | 3906 | lp->stopped = 0; |
e3e9f5a2 PA |
3907 | lp->stopped_by_watchpoint = 0; |
3908 | } | |
3909 | ||
3910 | return 0; | |
3911 | } | |
3912 | ||
7feb7d06 PA |
3913 | static ptid_t |
3914 | linux_nat_wait (struct target_ops *ops, | |
47608cb1 PA |
3915 | ptid_t ptid, struct target_waitstatus *ourstatus, |
3916 | int target_options) | |
7feb7d06 PA |
3917 | { |
3918 | ptid_t event_ptid; | |
3919 | ||
3920 | if (debug_linux_nat) | |
09826ec5 PA |
3921 | { |
3922 | char *options_string; | |
3923 | ||
3924 | options_string = target_options_to_string (target_options); | |
3925 | fprintf_unfiltered (gdb_stdlog, | |
3926 | "linux_nat_wait: [%s], [%s]\n", | |
3927 | target_pid_to_str (ptid), | |
3928 | options_string); | |
3929 | xfree (options_string); | |
3930 | } | |
7feb7d06 PA |
3931 | |
3932 | /* Flush the async file first. */ | |
3933 | if (target_can_async_p ()) | |
3934 | async_file_flush (); | |
3935 | ||
e3e9f5a2 PA |
3936 | /* Resume LWPs that are currently stopped without any pending status |
3937 | to report, but are resumed from the core's perspective. LWPs get | |
3938 | in this state if we find them stopping at a time we're not | |
3939 | interested in reporting the event (target_wait on a | |
3940 | specific_process, for example, see linux_nat_wait_1), and | |
3941 | meanwhile the event became uninteresting. Don't bother resuming | |
3942 | LWPs we're not going to wait for if they'd stop immediately. */ | |
3943 | if (non_stop) | |
3944 | iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid); | |
3945 | ||
47608cb1 | 3946 | event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options); |
7feb7d06 PA |
3947 | |
3948 | /* If we requested any event, and something came out, assume there | |
3949 | may be more. If we requested a specific lwp or process, also | |
3950 | assume there may be more. */ | |
3951 | if (target_can_async_p () | |
6953d224 PA |
3952 | && ((ourstatus->kind != TARGET_WAITKIND_IGNORE |
3953 | && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED) | |
7feb7d06 PA |
3954 | || !ptid_equal (ptid, minus_one_ptid))) |
3955 | async_file_mark (); | |
3956 | ||
3957 | /* Get ready for the next event. */ | |
3958 | if (target_can_async_p ()) | |
3959 | target_async (inferior_event_handler, 0); | |
3960 | ||
3961 | return event_ptid; | |
3962 | } | |
3963 | ||
d6b0e80f AC |
3964 | static int |
3965 | kill_callback (struct lwp_info *lp, void *data) | |
3966 | { | |
ed731959 JK |
3967 | /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
3968 | ||
3969 | errno = 0; | |
3970 | kill (GET_LWP (lp->ptid), SIGKILL); | |
3971 | if (debug_linux_nat) | |
3972 | fprintf_unfiltered (gdb_stdlog, | |
3973 | "KC: kill (SIGKILL) %s, 0, 0 (%s)\n", | |
3974 | target_pid_to_str (lp->ptid), | |
3975 | errno ? safe_strerror (errno) : "OK"); | |
3976 | ||
3977 | /* Some kernels ignore even SIGKILL for processes under ptrace. */ | |
3978 | ||
d6b0e80f AC |
3979 | errno = 0; |
3980 | ptrace (PTRACE_KILL, GET_LWP (lp->ptid), 0, 0); | |
3981 | if (debug_linux_nat) | |
3982 | fprintf_unfiltered (gdb_stdlog, | |
3983 | "KC: PTRACE_KILL %s, 0, 0 (%s)\n", | |
3984 | target_pid_to_str (lp->ptid), | |
3985 | errno ? safe_strerror (errno) : "OK"); | |
3986 | ||
3987 | return 0; | |
3988 | } | |
3989 | ||
3990 | static int | |
3991 | kill_wait_callback (struct lwp_info *lp, void *data) | |
3992 | { | |
3993 | pid_t pid; | |
3994 | ||
3995 | /* We must make sure that there are no pending events (delayed | |
3996 | SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current | |
3997 | program doesn't interfere with any following debugging session. */ | |
3998 | ||
3999 | /* For cloned processes we must check both with __WCLONE and | |
4000 | without, since the exit status of a cloned process isn't reported | |
4001 | with __WCLONE. */ | |
4002 | if (lp->cloned) | |
4003 | { | |
4004 | do | |
4005 | { | |
58aecb61 | 4006 | pid = my_waitpid (GET_LWP (lp->ptid), NULL, __WCLONE); |
e85a822c | 4007 | if (pid != (pid_t) -1) |
d6b0e80f | 4008 | { |
e85a822c DJ |
4009 | if (debug_linux_nat) |
4010 | fprintf_unfiltered (gdb_stdlog, | |
4011 | "KWC: wait %s received unknown.\n", | |
4012 | target_pid_to_str (lp->ptid)); | |
4013 | /* The Linux kernel sometimes fails to kill a thread | |
4014 | completely after PTRACE_KILL; that goes from the stop | |
4015 | point in do_fork out to the one in | |
4016 | get_signal_to_deliever and waits again. So kill it | |
4017 | again. */ | |
4018 | kill_callback (lp, NULL); | |
d6b0e80f AC |
4019 | } |
4020 | } | |
4021 | while (pid == GET_LWP (lp->ptid)); | |
4022 | ||
4023 | gdb_assert (pid == -1 && errno == ECHILD); | |
4024 | } | |
4025 | ||
4026 | do | |
4027 | { | |
58aecb61 | 4028 | pid = my_waitpid (GET_LWP (lp->ptid), NULL, 0); |
e85a822c | 4029 | if (pid != (pid_t) -1) |
d6b0e80f | 4030 | { |
e85a822c DJ |
4031 | if (debug_linux_nat) |
4032 | fprintf_unfiltered (gdb_stdlog, | |
4033 | "KWC: wait %s received unk.\n", | |
4034 | target_pid_to_str (lp->ptid)); | |
4035 | /* See the call to kill_callback above. */ | |
4036 | kill_callback (lp, NULL); | |
d6b0e80f AC |
4037 | } |
4038 | } | |
4039 | while (pid == GET_LWP (lp->ptid)); | |
4040 | ||
4041 | gdb_assert (pid == -1 && errno == ECHILD); | |
4042 | return 0; | |
4043 | } | |
4044 | ||
4045 | static void | |
7d85a9c0 | 4046 | linux_nat_kill (struct target_ops *ops) |
d6b0e80f | 4047 | { |
f973ed9c DJ |
4048 | struct target_waitstatus last; |
4049 | ptid_t last_ptid; | |
4050 | int status; | |
d6b0e80f | 4051 | |
f973ed9c DJ |
4052 | /* If we're stopped while forking and we haven't followed yet, |
4053 | kill the other task. We need to do this first because the | |
4054 | parent will be sleeping if this is a vfork. */ | |
d6b0e80f | 4055 | |
f973ed9c | 4056 | get_last_target_status (&last_ptid, &last); |
d6b0e80f | 4057 | |
f973ed9c DJ |
4058 | if (last.kind == TARGET_WAITKIND_FORKED |
4059 | || last.kind == TARGET_WAITKIND_VFORKED) | |
4060 | { | |
3a3e9ee3 | 4061 | ptrace (PT_KILL, PIDGET (last.value.related_pid), 0, 0); |
f973ed9c | 4062 | wait (&status); |
26cb8b7c PA |
4063 | |
4064 | /* Let the arch-specific native code know this process is | |
4065 | gone. */ | |
4066 | linux_nat_forget_process (PIDGET (last.value.related_pid)); | |
f973ed9c DJ |
4067 | } |
4068 | ||
4069 | if (forks_exist_p ()) | |
7feb7d06 | 4070 | linux_fork_killall (); |
f973ed9c DJ |
4071 | else |
4072 | { | |
d90e17a7 | 4073 | ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid)); |
e0881a8e | 4074 | |
4c28f408 PA |
4075 | /* Stop all threads before killing them, since ptrace requires |
4076 | that the thread is stopped to sucessfully PTRACE_KILL. */ | |
d90e17a7 | 4077 | iterate_over_lwps (ptid, stop_callback, NULL); |
4c28f408 PA |
4078 | /* ... and wait until all of them have reported back that |
4079 | they're no longer running. */ | |
d90e17a7 | 4080 | iterate_over_lwps (ptid, stop_wait_callback, NULL); |
4c28f408 | 4081 | |
f973ed9c | 4082 | /* Kill all LWP's ... */ |
d90e17a7 | 4083 | iterate_over_lwps (ptid, kill_callback, NULL); |
f973ed9c DJ |
4084 | |
4085 | /* ... and wait until we've flushed all events. */ | |
d90e17a7 | 4086 | iterate_over_lwps (ptid, kill_wait_callback, NULL); |
f973ed9c DJ |
4087 | } |
4088 | ||
4089 | target_mourn_inferior (); | |
d6b0e80f AC |
4090 | } |
4091 | ||
4092 | static void | |
136d6dae | 4093 | linux_nat_mourn_inferior (struct target_ops *ops) |
d6b0e80f | 4094 | { |
26cb8b7c PA |
4095 | int pid = ptid_get_pid (inferior_ptid); |
4096 | ||
4097 | purge_lwp_list (pid); | |
d6b0e80f | 4098 | |
f973ed9c | 4099 | if (! forks_exist_p ()) |
d90e17a7 PA |
4100 | /* Normal case, no other forks available. */ |
4101 | linux_ops->to_mourn_inferior (ops); | |
f973ed9c DJ |
4102 | else |
4103 | /* Multi-fork case. The current inferior_ptid has exited, but | |
4104 | there are other viable forks to debug. Delete the exiting | |
4105 | one and context-switch to the first available. */ | |
4106 | linux_fork_mourn_inferior (); | |
26cb8b7c PA |
4107 | |
4108 | /* Let the arch-specific native code know this process is gone. */ | |
4109 | linux_nat_forget_process (pid); | |
d6b0e80f AC |
4110 | } |
4111 | ||
5b009018 PA |
4112 | /* Convert a native/host siginfo object, into/from the siginfo in the |
4113 | layout of the inferiors' architecture. */ | |
4114 | ||
4115 | static void | |
a5362b9a | 4116 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
5b009018 PA |
4117 | { |
4118 | int done = 0; | |
4119 | ||
4120 | if (linux_nat_siginfo_fixup != NULL) | |
4121 | done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction); | |
4122 | ||
4123 | /* If there was no callback, or the callback didn't do anything, | |
4124 | then just do a straight memcpy. */ | |
4125 | if (!done) | |
4126 | { | |
4127 | if (direction == 1) | |
a5362b9a | 4128 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
5b009018 | 4129 | else |
a5362b9a | 4130 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
5b009018 PA |
4131 | } |
4132 | } | |
4133 | ||
4aa995e1 PA |
4134 | static LONGEST |
4135 | linux_xfer_siginfo (struct target_ops *ops, enum target_object object, | |
4136 | const char *annex, gdb_byte *readbuf, | |
4137 | const gdb_byte *writebuf, ULONGEST offset, LONGEST len) | |
4138 | { | |
4aa995e1 | 4139 | int pid; |
a5362b9a TS |
4140 | siginfo_t siginfo; |
4141 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; | |
4aa995e1 PA |
4142 | |
4143 | gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO); | |
4144 | gdb_assert (readbuf || writebuf); | |
4145 | ||
4146 | pid = GET_LWP (inferior_ptid); | |
4147 | if (pid == 0) | |
4148 | pid = GET_PID (inferior_ptid); | |
4149 | ||
4150 | if (offset > sizeof (siginfo)) | |
4151 | return -1; | |
4152 | ||
4153 | errno = 0; | |
4154 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
4155 | if (errno != 0) | |
4156 | return -1; | |
4157 | ||
5b009018 PA |
4158 | /* When GDB is built as a 64-bit application, ptrace writes into |
4159 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
4160 | inferior with a 64-bit GDB should look the same as debugging it | |
4161 | with a 32-bit GDB, we need to convert it. GDB core always sees | |
4162 | the converted layout, so any read/write will have to be done | |
4163 | post-conversion. */ | |
4164 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
4165 | ||
4aa995e1 PA |
4166 | if (offset + len > sizeof (siginfo)) |
4167 | len = sizeof (siginfo) - offset; | |
4168 | ||
4169 | if (readbuf != NULL) | |
5b009018 | 4170 | memcpy (readbuf, inf_siginfo + offset, len); |
4aa995e1 PA |
4171 | else |
4172 | { | |
5b009018 PA |
4173 | memcpy (inf_siginfo + offset, writebuf, len); |
4174 | ||
4175 | /* Convert back to ptrace layout before flushing it out. */ | |
4176 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
4177 | ||
4aa995e1 PA |
4178 | errno = 0; |
4179 | ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
4180 | if (errno != 0) | |
4181 | return -1; | |
4182 | } | |
4183 | ||
4184 | return len; | |
4185 | } | |
4186 | ||
10d6c8cd DJ |
4187 | static LONGEST |
4188 | linux_nat_xfer_partial (struct target_ops *ops, enum target_object object, | |
4189 | const char *annex, gdb_byte *readbuf, | |
4190 | const gdb_byte *writebuf, | |
4191 | ULONGEST offset, LONGEST len) | |
d6b0e80f | 4192 | { |
4aa995e1 | 4193 | struct cleanup *old_chain; |
10d6c8cd | 4194 | LONGEST xfer; |
d6b0e80f | 4195 | |
4aa995e1 PA |
4196 | if (object == TARGET_OBJECT_SIGNAL_INFO) |
4197 | return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf, | |
4198 | offset, len); | |
4199 | ||
c35b1492 PA |
4200 | /* The target is connected but no live inferior is selected. Pass |
4201 | this request down to a lower stratum (e.g., the executable | |
4202 | file). */ | |
4203 | if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid)) | |
4204 | return 0; | |
4205 | ||
4aa995e1 PA |
4206 | old_chain = save_inferior_ptid (); |
4207 | ||
d6b0e80f AC |
4208 | if (is_lwp (inferior_ptid)) |
4209 | inferior_ptid = pid_to_ptid (GET_LWP (inferior_ptid)); | |
4210 | ||
10d6c8cd DJ |
4211 | xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf, |
4212 | offset, len); | |
d6b0e80f AC |
4213 | |
4214 | do_cleanups (old_chain); | |
4215 | return xfer; | |
4216 | } | |
4217 | ||
4218 | static int | |
28439f5e | 4219 | linux_thread_alive (ptid_t ptid) |
d6b0e80f | 4220 | { |
8c6a60d1 | 4221 | int err, tmp_errno; |
4c28f408 | 4222 | |
d6b0e80f AC |
4223 | gdb_assert (is_lwp (ptid)); |
4224 | ||
4c28f408 PA |
4225 | /* Send signal 0 instead of anything ptrace, because ptracing a |
4226 | running thread errors out claiming that the thread doesn't | |
4227 | exist. */ | |
4228 | err = kill_lwp (GET_LWP (ptid), 0); | |
8c6a60d1 | 4229 | tmp_errno = errno; |
d6b0e80f AC |
4230 | if (debug_linux_nat) |
4231 | fprintf_unfiltered (gdb_stdlog, | |
4c28f408 | 4232 | "LLTA: KILL(SIG0) %s (%s)\n", |
d6b0e80f | 4233 | target_pid_to_str (ptid), |
8c6a60d1 | 4234 | err ? safe_strerror (tmp_errno) : "OK"); |
9c0dd46b | 4235 | |
4c28f408 | 4236 | if (err != 0) |
d6b0e80f AC |
4237 | return 0; |
4238 | ||
4239 | return 1; | |
4240 | } | |
4241 | ||
28439f5e PA |
4242 | static int |
4243 | linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid) | |
4244 | { | |
4245 | return linux_thread_alive (ptid); | |
4246 | } | |
4247 | ||
d6b0e80f | 4248 | static char * |
117de6a9 | 4249 | linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid) |
d6b0e80f AC |
4250 | { |
4251 | static char buf[64]; | |
4252 | ||
a0ef4274 | 4253 | if (is_lwp (ptid) |
d90e17a7 PA |
4254 | && (GET_PID (ptid) != GET_LWP (ptid) |
4255 | || num_lwps (GET_PID (ptid)) > 1)) | |
d6b0e80f AC |
4256 | { |
4257 | snprintf (buf, sizeof (buf), "LWP %ld", GET_LWP (ptid)); | |
4258 | return buf; | |
4259 | } | |
4260 | ||
4261 | return normal_pid_to_str (ptid); | |
4262 | } | |
4263 | ||
4694da01 TT |
4264 | static char * |
4265 | linux_nat_thread_name (struct thread_info *thr) | |
4266 | { | |
4267 | int pid = ptid_get_pid (thr->ptid); | |
4268 | long lwp = ptid_get_lwp (thr->ptid); | |
4269 | #define FORMAT "/proc/%d/task/%ld/comm" | |
4270 | char buf[sizeof (FORMAT) + 30]; | |
4271 | FILE *comm_file; | |
4272 | char *result = NULL; | |
4273 | ||
4274 | snprintf (buf, sizeof (buf), FORMAT, pid, lwp); | |
614c279d | 4275 | comm_file = gdb_fopen_cloexec (buf, "r"); |
4694da01 TT |
4276 | if (comm_file) |
4277 | { | |
4278 | /* Not exported by the kernel, so we define it here. */ | |
4279 | #define COMM_LEN 16 | |
4280 | static char line[COMM_LEN + 1]; | |
4281 | ||
4282 | if (fgets (line, sizeof (line), comm_file)) | |
4283 | { | |
4284 | char *nl = strchr (line, '\n'); | |
4285 | ||
4286 | if (nl) | |
4287 | *nl = '\0'; | |
4288 | if (*line != '\0') | |
4289 | result = line; | |
4290 | } | |
4291 | ||
4292 | fclose (comm_file); | |
4293 | } | |
4294 | ||
4295 | #undef COMM_LEN | |
4296 | #undef FORMAT | |
4297 | ||
4298 | return result; | |
4299 | } | |
4300 | ||
dba24537 AC |
4301 | /* Accepts an integer PID; Returns a string representing a file that |
4302 | can be opened to get the symbols for the child process. */ | |
4303 | ||
6d8fd2b7 UW |
4304 | static char * |
4305 | linux_child_pid_to_exec_file (int pid) | |
dba24537 AC |
4306 | { |
4307 | char *name1, *name2; | |
4308 | ||
4309 | name1 = xmalloc (MAXPATHLEN); | |
4310 | name2 = xmalloc (MAXPATHLEN); | |
4311 | make_cleanup (xfree, name1); | |
4312 | make_cleanup (xfree, name2); | |
4313 | memset (name2, 0, MAXPATHLEN); | |
4314 | ||
4315 | sprintf (name1, "/proc/%d/exe", pid); | |
0270a750 | 4316 | if (readlink (name1, name2, MAXPATHLEN - 1) > 0) |
dba24537 AC |
4317 | return name2; |
4318 | else | |
4319 | return name1; | |
4320 | } | |
4321 | ||
dba24537 AC |
4322 | /* Records the thread's register state for the corefile note |
4323 | section. */ | |
4324 | ||
4325 | static char * | |
6432734d UW |
4326 | linux_nat_collect_thread_registers (const struct regcache *regcache, |
4327 | ptid_t ptid, bfd *obfd, | |
4328 | char *note_data, int *note_size, | |
2ea28649 | 4329 | enum gdb_signal stop_signal) |
dba24537 | 4330 | { |
6432734d | 4331 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
4f844a66 | 4332 | const struct regset *regset; |
55e969c1 | 4333 | int core_regset_p; |
6432734d UW |
4334 | gdb_gregset_t gregs; |
4335 | gdb_fpregset_t fpregs; | |
4f844a66 DM |
4336 | |
4337 | core_regset_p = gdbarch_regset_from_core_section_p (gdbarch); | |
dba24537 | 4338 | |
6432734d UW |
4339 | if (core_regset_p |
4340 | && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg", | |
4341 | sizeof (gregs))) | |
4342 | != NULL && regset->collect_regset != NULL) | |
4343 | regset->collect_regset (regset, regcache, -1, &gregs, sizeof (gregs)); | |
4f844a66 | 4344 | else |
6432734d | 4345 | fill_gregset (regcache, &gregs, -1); |
2f2241f1 | 4346 | |
6432734d UW |
4347 | note_data = (char *) elfcore_write_prstatus |
4348 | (obfd, note_data, note_size, ptid_get_lwp (ptid), | |
2ea28649 | 4349 | gdb_signal_to_host (stop_signal), &gregs); |
2f2241f1 | 4350 | |
6432734d UW |
4351 | if (core_regset_p |
4352 | && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg2", | |
4353 | sizeof (fpregs))) | |
3e43a32a | 4354 | != NULL && regset->collect_regset != NULL) |
6432734d UW |
4355 | regset->collect_regset (regset, regcache, -1, &fpregs, sizeof (fpregs)); |
4356 | else | |
4357 | fill_fpregset (regcache, &fpregs, -1); | |
17ea7499 | 4358 | |
6432734d UW |
4359 | note_data = (char *) elfcore_write_prfpreg (obfd, note_data, note_size, |
4360 | &fpregs, sizeof (fpregs)); | |
4f844a66 | 4361 | |
dba24537 AC |
4362 | return note_data; |
4363 | } | |
4364 | ||
dba24537 AC |
4365 | /* Fills the "to_make_corefile_note" target vector. Builds the note |
4366 | section for a corefile, and returns it in a malloc buffer. */ | |
4367 | ||
4368 | static char * | |
4369 | linux_nat_make_corefile_notes (bfd *obfd, int *note_size) | |
4370 | { | |
6432734d UW |
4371 | /* FIXME: uweigand/2011-10-06: Once all GNU/Linux architectures have been |
4372 | converted to gdbarch_core_regset_sections, this function can go away. */ | |
f5656ead | 4373 | return linux_make_corefile_notes (target_gdbarch (), obfd, note_size, |
6432734d | 4374 | linux_nat_collect_thread_registers); |
dba24537 AC |
4375 | } |
4376 | ||
10d6c8cd DJ |
4377 | /* Implement the to_xfer_partial interface for memory reads using the /proc |
4378 | filesystem. Because we can use a single read() call for /proc, this | |
4379 | can be much more efficient than banging away at PTRACE_PEEKTEXT, | |
4380 | but it doesn't support writes. */ | |
4381 | ||
4382 | static LONGEST | |
4383 | linux_proc_xfer_partial (struct target_ops *ops, enum target_object object, | |
4384 | const char *annex, gdb_byte *readbuf, | |
4385 | const gdb_byte *writebuf, | |
4386 | ULONGEST offset, LONGEST len) | |
dba24537 | 4387 | { |
10d6c8cd DJ |
4388 | LONGEST ret; |
4389 | int fd; | |
dba24537 AC |
4390 | char filename[64]; |
4391 | ||
10d6c8cd | 4392 | if (object != TARGET_OBJECT_MEMORY || !readbuf) |
dba24537 AC |
4393 | return 0; |
4394 | ||
4395 | /* Don't bother for one word. */ | |
4396 | if (len < 3 * sizeof (long)) | |
4397 | return 0; | |
4398 | ||
4399 | /* We could keep this file open and cache it - possibly one per | |
4400 | thread. That requires some juggling, but is even faster. */ | |
4401 | sprintf (filename, "/proc/%d/mem", PIDGET (inferior_ptid)); | |
614c279d | 4402 | fd = gdb_open_cloexec (filename, O_RDONLY | O_LARGEFILE, 0); |
dba24537 AC |
4403 | if (fd == -1) |
4404 | return 0; | |
4405 | ||
4406 | /* If pread64 is available, use it. It's faster if the kernel | |
4407 | supports it (only one syscall), and it's 64-bit safe even on | |
4408 | 32-bit platforms (for instance, SPARC debugging a SPARC64 | |
4409 | application). */ | |
4410 | #ifdef HAVE_PREAD64 | |
10d6c8cd | 4411 | if (pread64 (fd, readbuf, len, offset) != len) |
dba24537 | 4412 | #else |
10d6c8cd | 4413 | if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len) |
dba24537 AC |
4414 | #endif |
4415 | ret = 0; | |
4416 | else | |
4417 | ret = len; | |
4418 | ||
4419 | close (fd); | |
4420 | return ret; | |
4421 | } | |
4422 | ||
efcbbd14 UW |
4423 | |
4424 | /* Enumerate spufs IDs for process PID. */ | |
4425 | static LONGEST | |
4426 | spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, LONGEST len) | |
4427 | { | |
f5656ead | 4428 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
efcbbd14 UW |
4429 | LONGEST pos = 0; |
4430 | LONGEST written = 0; | |
4431 | char path[128]; | |
4432 | DIR *dir; | |
4433 | struct dirent *entry; | |
4434 | ||
4435 | xsnprintf (path, sizeof path, "/proc/%d/fd", pid); | |
4436 | dir = opendir (path); | |
4437 | if (!dir) | |
4438 | return -1; | |
4439 | ||
4440 | rewinddir (dir); | |
4441 | while ((entry = readdir (dir)) != NULL) | |
4442 | { | |
4443 | struct stat st; | |
4444 | struct statfs stfs; | |
4445 | int fd; | |
4446 | ||
4447 | fd = atoi (entry->d_name); | |
4448 | if (!fd) | |
4449 | continue; | |
4450 | ||
4451 | xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd); | |
4452 | if (stat (path, &st) != 0) | |
4453 | continue; | |
4454 | if (!S_ISDIR (st.st_mode)) | |
4455 | continue; | |
4456 | ||
4457 | if (statfs (path, &stfs) != 0) | |
4458 | continue; | |
4459 | if (stfs.f_type != SPUFS_MAGIC) | |
4460 | continue; | |
4461 | ||
4462 | if (pos >= offset && pos + 4 <= offset + len) | |
4463 | { | |
4464 | store_unsigned_integer (buf + pos - offset, 4, byte_order, fd); | |
4465 | written += 4; | |
4466 | } | |
4467 | pos += 4; | |
4468 | } | |
4469 | ||
4470 | closedir (dir); | |
4471 | return written; | |
4472 | } | |
4473 | ||
4474 | /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU | |
4475 | object type, using the /proc file system. */ | |
4476 | static LONGEST | |
4477 | linux_proc_xfer_spu (struct target_ops *ops, enum target_object object, | |
4478 | const char *annex, gdb_byte *readbuf, | |
4479 | const gdb_byte *writebuf, | |
4480 | ULONGEST offset, LONGEST len) | |
4481 | { | |
4482 | char buf[128]; | |
4483 | int fd = 0; | |
4484 | int ret = -1; | |
4485 | int pid = PIDGET (inferior_ptid); | |
4486 | ||
4487 | if (!annex) | |
4488 | { | |
4489 | if (!readbuf) | |
4490 | return -1; | |
4491 | else | |
4492 | return spu_enumerate_spu_ids (pid, readbuf, offset, len); | |
4493 | } | |
4494 | ||
4495 | xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex); | |
614c279d | 4496 | fd = gdb_open_cloexec (buf, writebuf? O_WRONLY : O_RDONLY, 0); |
efcbbd14 UW |
4497 | if (fd <= 0) |
4498 | return -1; | |
4499 | ||
4500 | if (offset != 0 | |
4501 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) | |
4502 | { | |
4503 | close (fd); | |
4504 | return 0; | |
4505 | } | |
4506 | ||
4507 | if (writebuf) | |
4508 | ret = write (fd, writebuf, (size_t) len); | |
4509 | else if (readbuf) | |
4510 | ret = read (fd, readbuf, (size_t) len); | |
4511 | ||
4512 | close (fd); | |
4513 | return ret; | |
4514 | } | |
4515 | ||
4516 | ||
dba24537 AC |
4517 | /* Parse LINE as a signal set and add its set bits to SIGS. */ |
4518 | ||
4519 | static void | |
4520 | add_line_to_sigset (const char *line, sigset_t *sigs) | |
4521 | { | |
4522 | int len = strlen (line) - 1; | |
4523 | const char *p; | |
4524 | int signum; | |
4525 | ||
4526 | if (line[len] != '\n') | |
8a3fe4f8 | 4527 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4528 | |
4529 | p = line; | |
4530 | signum = len * 4; | |
4531 | while (len-- > 0) | |
4532 | { | |
4533 | int digit; | |
4534 | ||
4535 | if (*p >= '0' && *p <= '9') | |
4536 | digit = *p - '0'; | |
4537 | else if (*p >= 'a' && *p <= 'f') | |
4538 | digit = *p - 'a' + 10; | |
4539 | else | |
8a3fe4f8 | 4540 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4541 | |
4542 | signum -= 4; | |
4543 | ||
4544 | if (digit & 1) | |
4545 | sigaddset (sigs, signum + 1); | |
4546 | if (digit & 2) | |
4547 | sigaddset (sigs, signum + 2); | |
4548 | if (digit & 4) | |
4549 | sigaddset (sigs, signum + 3); | |
4550 | if (digit & 8) | |
4551 | sigaddset (sigs, signum + 4); | |
4552 | ||
4553 | p++; | |
4554 | } | |
4555 | } | |
4556 | ||
4557 | /* Find process PID's pending signals from /proc/pid/status and set | |
4558 | SIGS to match. */ | |
4559 | ||
4560 | void | |
3e43a32a MS |
4561 | linux_proc_pending_signals (int pid, sigset_t *pending, |
4562 | sigset_t *blocked, sigset_t *ignored) | |
dba24537 AC |
4563 | { |
4564 | FILE *procfile; | |
4565 | char buffer[MAXPATHLEN], fname[MAXPATHLEN]; | |
7c8a8b04 | 4566 | struct cleanup *cleanup; |
dba24537 AC |
4567 | |
4568 | sigemptyset (pending); | |
4569 | sigemptyset (blocked); | |
4570 | sigemptyset (ignored); | |
4571 | sprintf (fname, "/proc/%d/status", pid); | |
614c279d | 4572 | procfile = gdb_fopen_cloexec (fname, "r"); |
dba24537 | 4573 | if (procfile == NULL) |
8a3fe4f8 | 4574 | error (_("Could not open %s"), fname); |
7c8a8b04 | 4575 | cleanup = make_cleanup_fclose (procfile); |
dba24537 AC |
4576 | |
4577 | while (fgets (buffer, MAXPATHLEN, procfile) != NULL) | |
4578 | { | |
4579 | /* Normal queued signals are on the SigPnd line in the status | |
4580 | file. However, 2.6 kernels also have a "shared" pending | |
4581 | queue for delivering signals to a thread group, so check for | |
4582 | a ShdPnd line also. | |
4583 | ||
4584 | Unfortunately some Red Hat kernels include the shared pending | |
4585 | queue but not the ShdPnd status field. */ | |
4586 | ||
4587 | if (strncmp (buffer, "SigPnd:\t", 8) == 0) | |
4588 | add_line_to_sigset (buffer + 8, pending); | |
4589 | else if (strncmp (buffer, "ShdPnd:\t", 8) == 0) | |
4590 | add_line_to_sigset (buffer + 8, pending); | |
4591 | else if (strncmp (buffer, "SigBlk:\t", 8) == 0) | |
4592 | add_line_to_sigset (buffer + 8, blocked); | |
4593 | else if (strncmp (buffer, "SigIgn:\t", 8) == 0) | |
4594 | add_line_to_sigset (buffer + 8, ignored); | |
4595 | } | |
4596 | ||
7c8a8b04 | 4597 | do_cleanups (cleanup); |
dba24537 AC |
4598 | } |
4599 | ||
07e059b5 VP |
4600 | static LONGEST |
4601 | linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object, | |
e0881a8e MS |
4602 | const char *annex, gdb_byte *readbuf, |
4603 | const gdb_byte *writebuf, ULONGEST offset, LONGEST len) | |
07e059b5 | 4604 | { |
07e059b5 VP |
4605 | gdb_assert (object == TARGET_OBJECT_OSDATA); |
4606 | ||
d26e3629 | 4607 | return linux_common_xfer_osdata (annex, readbuf, offset, len); |
07e059b5 VP |
4608 | } |
4609 | ||
10d6c8cd DJ |
4610 | static LONGEST |
4611 | linux_xfer_partial (struct target_ops *ops, enum target_object object, | |
4612 | const char *annex, gdb_byte *readbuf, | |
4613 | const gdb_byte *writebuf, ULONGEST offset, LONGEST len) | |
4614 | { | |
4615 | LONGEST xfer; | |
4616 | ||
4617 | if (object == TARGET_OBJECT_AUXV) | |
9f2982ff | 4618 | return memory_xfer_auxv (ops, object, annex, readbuf, writebuf, |
10d6c8cd DJ |
4619 | offset, len); |
4620 | ||
07e059b5 VP |
4621 | if (object == TARGET_OBJECT_OSDATA) |
4622 | return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf, | |
4623 | offset, len); | |
4624 | ||
efcbbd14 UW |
4625 | if (object == TARGET_OBJECT_SPU) |
4626 | return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf, | |
4627 | offset, len); | |
4628 | ||
8f313923 JK |
4629 | /* GDB calculates all the addresses in possibly larget width of the address. |
4630 | Address width needs to be masked before its final use - either by | |
4631 | linux_proc_xfer_partial or inf_ptrace_xfer_partial. | |
4632 | ||
4633 | Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ | |
4634 | ||
4635 | if (object == TARGET_OBJECT_MEMORY) | |
4636 | { | |
f5656ead | 4637 | int addr_bit = gdbarch_addr_bit (target_gdbarch ()); |
8f313923 JK |
4638 | |
4639 | if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) | |
4640 | offset &= ((ULONGEST) 1 << addr_bit) - 1; | |
4641 | } | |
4642 | ||
10d6c8cd DJ |
4643 | xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf, |
4644 | offset, len); | |
4645 | if (xfer != 0) | |
4646 | return xfer; | |
4647 | ||
4648 | return super_xfer_partial (ops, object, annex, readbuf, writebuf, | |
4649 | offset, len); | |
4650 | } | |
4651 | ||
5808517f YQ |
4652 | static void |
4653 | cleanup_target_stop (void *arg) | |
4654 | { | |
4655 | ptid_t *ptid = (ptid_t *) arg; | |
4656 | ||
4657 | gdb_assert (arg != NULL); | |
4658 | ||
4659 | /* Unpause all */ | |
a493e3e2 | 4660 | target_resume (*ptid, 0, GDB_SIGNAL_0); |
5808517f YQ |
4661 | } |
4662 | ||
4663 | static VEC(static_tracepoint_marker_p) * | |
4664 | linux_child_static_tracepoint_markers_by_strid (const char *strid) | |
4665 | { | |
4666 | char s[IPA_CMD_BUF_SIZE]; | |
4667 | struct cleanup *old_chain; | |
4668 | int pid = ptid_get_pid (inferior_ptid); | |
4669 | VEC(static_tracepoint_marker_p) *markers = NULL; | |
4670 | struct static_tracepoint_marker *marker = NULL; | |
4671 | char *p = s; | |
4672 | ptid_t ptid = ptid_build (pid, 0, 0); | |
4673 | ||
4674 | /* Pause all */ | |
4675 | target_stop (ptid); | |
4676 | ||
4677 | memcpy (s, "qTfSTM", sizeof ("qTfSTM")); | |
4678 | s[sizeof ("qTfSTM")] = 0; | |
4679 | ||
42476b70 | 4680 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4681 | |
4682 | old_chain = make_cleanup (free_current_marker, &marker); | |
4683 | make_cleanup (cleanup_target_stop, &ptid); | |
4684 | ||
4685 | while (*p++ == 'm') | |
4686 | { | |
4687 | if (marker == NULL) | |
4688 | marker = XCNEW (struct static_tracepoint_marker); | |
4689 | ||
4690 | do | |
4691 | { | |
4692 | parse_static_tracepoint_marker_definition (p, &p, marker); | |
4693 | ||
4694 | if (strid == NULL || strcmp (strid, marker->str_id) == 0) | |
4695 | { | |
4696 | VEC_safe_push (static_tracepoint_marker_p, | |
4697 | markers, marker); | |
4698 | marker = NULL; | |
4699 | } | |
4700 | else | |
4701 | { | |
4702 | release_static_tracepoint_marker (marker); | |
4703 | memset (marker, 0, sizeof (*marker)); | |
4704 | } | |
4705 | } | |
4706 | while (*p++ == ','); /* comma-separated list */ | |
4707 | ||
4708 | memcpy (s, "qTsSTM", sizeof ("qTsSTM")); | |
4709 | s[sizeof ("qTsSTM")] = 0; | |
42476b70 | 4710 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4711 | p = s; |
4712 | } | |
4713 | ||
4714 | do_cleanups (old_chain); | |
4715 | ||
4716 | return markers; | |
4717 | } | |
4718 | ||
e9efe249 | 4719 | /* Create a prototype generic GNU/Linux target. The client can override |
10d6c8cd DJ |
4720 | it with local methods. */ |
4721 | ||
910122bf UW |
4722 | static void |
4723 | linux_target_install_ops (struct target_ops *t) | |
10d6c8cd | 4724 | { |
6d8fd2b7 | 4725 | t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint; |
eb73ad13 | 4726 | t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint; |
6d8fd2b7 | 4727 | t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint; |
eb73ad13 | 4728 | t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint; |
6d8fd2b7 | 4729 | t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint; |
eb73ad13 | 4730 | t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint; |
a96d9b2e | 4731 | t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint; |
6d8fd2b7 | 4732 | t->to_pid_to_exec_file = linux_child_pid_to_exec_file; |
10d6c8cd | 4733 | t->to_post_startup_inferior = linux_child_post_startup_inferior; |
6d8fd2b7 UW |
4734 | t->to_post_attach = linux_child_post_attach; |
4735 | t->to_follow_fork = linux_child_follow_fork; | |
10d6c8cd DJ |
4736 | t->to_make_corefile_notes = linux_nat_make_corefile_notes; |
4737 | ||
4738 | super_xfer_partial = t->to_xfer_partial; | |
4739 | t->to_xfer_partial = linux_xfer_partial; | |
5808517f YQ |
4740 | |
4741 | t->to_static_tracepoint_markers_by_strid | |
4742 | = linux_child_static_tracepoint_markers_by_strid; | |
910122bf UW |
4743 | } |
4744 | ||
4745 | struct target_ops * | |
4746 | linux_target (void) | |
4747 | { | |
4748 | struct target_ops *t; | |
4749 | ||
4750 | t = inf_ptrace_target (); | |
4751 | linux_target_install_ops (t); | |
4752 | ||
4753 | return t; | |
4754 | } | |
4755 | ||
4756 | struct target_ops * | |
7714d83a | 4757 | linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int)) |
910122bf UW |
4758 | { |
4759 | struct target_ops *t; | |
4760 | ||
4761 | t = inf_ptrace_trad_target (register_u_offset); | |
4762 | linux_target_install_ops (t); | |
10d6c8cd | 4763 | |
10d6c8cd DJ |
4764 | return t; |
4765 | } | |
4766 | ||
b84876c2 PA |
4767 | /* target_is_async_p implementation. */ |
4768 | ||
4769 | static int | |
4770 | linux_nat_is_async_p (void) | |
4771 | { | |
4772 | /* NOTE: palves 2008-03-21: We're only async when the user requests | |
7feb7d06 | 4773 | it explicitly with the "set target-async" command. |
b84876c2 | 4774 | Someday, linux will always be async. */ |
3dd5b83d | 4775 | return target_async_permitted; |
b84876c2 PA |
4776 | } |
4777 | ||
4778 | /* target_can_async_p implementation. */ | |
4779 | ||
4780 | static int | |
4781 | linux_nat_can_async_p (void) | |
4782 | { | |
4783 | /* NOTE: palves 2008-03-21: We're only async when the user requests | |
7feb7d06 | 4784 | it explicitly with the "set target-async" command. |
b84876c2 | 4785 | Someday, linux will always be async. */ |
3dd5b83d | 4786 | return target_async_permitted; |
b84876c2 PA |
4787 | } |
4788 | ||
9908b566 VP |
4789 | static int |
4790 | linux_nat_supports_non_stop (void) | |
4791 | { | |
4792 | return 1; | |
4793 | } | |
4794 | ||
d90e17a7 PA |
4795 | /* True if we want to support multi-process. To be removed when GDB |
4796 | supports multi-exec. */ | |
4797 | ||
2277426b | 4798 | int linux_multi_process = 1; |
d90e17a7 PA |
4799 | |
4800 | static int | |
4801 | linux_nat_supports_multi_process (void) | |
4802 | { | |
4803 | return linux_multi_process; | |
4804 | } | |
4805 | ||
03583c20 UW |
4806 | static int |
4807 | linux_nat_supports_disable_randomization (void) | |
4808 | { | |
4809 | #ifdef HAVE_PERSONALITY | |
4810 | return 1; | |
4811 | #else | |
4812 | return 0; | |
4813 | #endif | |
4814 | } | |
4815 | ||
b84876c2 PA |
4816 | static int async_terminal_is_ours = 1; |
4817 | ||
4818 | /* target_terminal_inferior implementation. */ | |
4819 | ||
4820 | static void | |
4821 | linux_nat_terminal_inferior (void) | |
4822 | { | |
4823 | if (!target_is_async_p ()) | |
4824 | { | |
4825 | /* Async mode is disabled. */ | |
4826 | terminal_inferior (); | |
4827 | return; | |
4828 | } | |
4829 | ||
b84876c2 PA |
4830 | terminal_inferior (); |
4831 | ||
d9d2d8b6 | 4832 | /* Calls to target_terminal_*() are meant to be idempotent. */ |
b84876c2 PA |
4833 | if (!async_terminal_is_ours) |
4834 | return; | |
4835 | ||
4836 | delete_file_handler (input_fd); | |
4837 | async_terminal_is_ours = 0; | |
4838 | set_sigint_trap (); | |
4839 | } | |
4840 | ||
4841 | /* target_terminal_ours implementation. */ | |
4842 | ||
2c0b251b | 4843 | static void |
b84876c2 PA |
4844 | linux_nat_terminal_ours (void) |
4845 | { | |
4846 | if (!target_is_async_p ()) | |
4847 | { | |
4848 | /* Async mode is disabled. */ | |
4849 | terminal_ours (); | |
4850 | return; | |
4851 | } | |
4852 | ||
4853 | /* GDB should never give the terminal to the inferior if the | |
4854 | inferior is running in the background (run&, continue&, etc.), | |
4855 | but claiming it sure should. */ | |
4856 | terminal_ours (); | |
4857 | ||
b84876c2 PA |
4858 | if (async_terminal_is_ours) |
4859 | return; | |
4860 | ||
4861 | clear_sigint_trap (); | |
4862 | add_file_handler (input_fd, stdin_event_handler, 0); | |
4863 | async_terminal_is_ours = 1; | |
4864 | } | |
4865 | ||
4866 | static void (*async_client_callback) (enum inferior_event_type event_type, | |
4867 | void *context); | |
4868 | static void *async_client_context; | |
4869 | ||
7feb7d06 PA |
4870 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
4871 | so we notice when any child changes state, and notify the | |
4872 | event-loop; it allows us to use sigsuspend in linux_nat_wait_1 | |
4873 | above to wait for the arrival of a SIGCHLD. */ | |
4874 | ||
b84876c2 | 4875 | static void |
7feb7d06 | 4876 | sigchld_handler (int signo) |
b84876c2 | 4877 | { |
7feb7d06 PA |
4878 | int old_errno = errno; |
4879 | ||
01124a23 DE |
4880 | if (debug_linux_nat) |
4881 | ui_file_write_async_safe (gdb_stdlog, | |
4882 | "sigchld\n", sizeof ("sigchld\n") - 1); | |
7feb7d06 PA |
4883 | |
4884 | if (signo == SIGCHLD | |
4885 | && linux_nat_event_pipe[0] != -1) | |
4886 | async_file_mark (); /* Let the event loop know that there are | |
4887 | events to handle. */ | |
4888 | ||
4889 | errno = old_errno; | |
4890 | } | |
4891 | ||
4892 | /* Callback registered with the target events file descriptor. */ | |
4893 | ||
4894 | static void | |
4895 | handle_target_event (int error, gdb_client_data client_data) | |
4896 | { | |
4897 | (*async_client_callback) (INF_REG_EVENT, async_client_context); | |
4898 | } | |
4899 | ||
4900 | /* Create/destroy the target events pipe. Returns previous state. */ | |
4901 | ||
4902 | static int | |
4903 | linux_async_pipe (int enable) | |
4904 | { | |
4905 | int previous = (linux_nat_event_pipe[0] != -1); | |
4906 | ||
4907 | if (previous != enable) | |
4908 | { | |
4909 | sigset_t prev_mask; | |
4910 | ||
4911 | block_child_signals (&prev_mask); | |
4912 | ||
4913 | if (enable) | |
4914 | { | |
614c279d | 4915 | if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1) |
7feb7d06 PA |
4916 | internal_error (__FILE__, __LINE__, |
4917 | "creating event pipe failed."); | |
4918 | ||
4919 | fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK); | |
4920 | fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK); | |
4921 | } | |
4922 | else | |
4923 | { | |
4924 | close (linux_nat_event_pipe[0]); | |
4925 | close (linux_nat_event_pipe[1]); | |
4926 | linux_nat_event_pipe[0] = -1; | |
4927 | linux_nat_event_pipe[1] = -1; | |
4928 | } | |
4929 | ||
4930 | restore_child_signals_mask (&prev_mask); | |
4931 | } | |
4932 | ||
4933 | return previous; | |
b84876c2 PA |
4934 | } |
4935 | ||
4936 | /* target_async implementation. */ | |
4937 | ||
4938 | static void | |
4939 | linux_nat_async (void (*callback) (enum inferior_event_type event_type, | |
4940 | void *context), void *context) | |
4941 | { | |
b84876c2 PA |
4942 | if (callback != NULL) |
4943 | { | |
4944 | async_client_callback = callback; | |
4945 | async_client_context = context; | |
7feb7d06 PA |
4946 | if (!linux_async_pipe (1)) |
4947 | { | |
4948 | add_file_handler (linux_nat_event_pipe[0], | |
4949 | handle_target_event, NULL); | |
4950 | /* There may be pending events to handle. Tell the event loop | |
4951 | to poll them. */ | |
4952 | async_file_mark (); | |
4953 | } | |
b84876c2 PA |
4954 | } |
4955 | else | |
4956 | { | |
4957 | async_client_callback = callback; | |
4958 | async_client_context = context; | |
b84876c2 | 4959 | delete_file_handler (linux_nat_event_pipe[0]); |
7feb7d06 | 4960 | linux_async_pipe (0); |
b84876c2 PA |
4961 | } |
4962 | return; | |
4963 | } | |
4964 | ||
a493e3e2 | 4965 | /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other |
252fbfc8 PA |
4966 | event came out. */ |
4967 | ||
4c28f408 | 4968 | static int |
252fbfc8 | 4969 | linux_nat_stop_lwp (struct lwp_info *lwp, void *data) |
4c28f408 | 4970 | { |
d90e17a7 | 4971 | if (!lwp->stopped) |
252fbfc8 | 4972 | { |
d90e17a7 PA |
4973 | if (debug_linux_nat) |
4974 | fprintf_unfiltered (gdb_stdlog, | |
4975 | "LNSL: running -> suspending %s\n", | |
4976 | target_pid_to_str (lwp->ptid)); | |
252fbfc8 | 4977 | |
252fbfc8 | 4978 | |
25289eb2 PA |
4979 | if (lwp->last_resume_kind == resume_stop) |
4980 | { | |
4981 | if (debug_linux_nat) | |
4982 | fprintf_unfiltered (gdb_stdlog, | |
4983 | "linux-nat: already stopping LWP %ld at " | |
4984 | "GDB's request\n", | |
4985 | ptid_get_lwp (lwp->ptid)); | |
4986 | return 0; | |
4987 | } | |
252fbfc8 | 4988 | |
25289eb2 PA |
4989 | stop_callback (lwp, NULL); |
4990 | lwp->last_resume_kind = resume_stop; | |
d90e17a7 PA |
4991 | } |
4992 | else | |
4993 | { | |
4994 | /* Already known to be stopped; do nothing. */ | |
252fbfc8 | 4995 | |
d90e17a7 PA |
4996 | if (debug_linux_nat) |
4997 | { | |
e09875d4 | 4998 | if (find_thread_ptid (lwp->ptid)->stop_requested) |
3e43a32a MS |
4999 | fprintf_unfiltered (gdb_stdlog, |
5000 | "LNSL: already stopped/stop_requested %s\n", | |
d90e17a7 PA |
5001 | target_pid_to_str (lwp->ptid)); |
5002 | else | |
3e43a32a MS |
5003 | fprintf_unfiltered (gdb_stdlog, |
5004 | "LNSL: already stopped/no " | |
5005 | "stop_requested yet %s\n", | |
d90e17a7 | 5006 | target_pid_to_str (lwp->ptid)); |
252fbfc8 PA |
5007 | } |
5008 | } | |
4c28f408 PA |
5009 | return 0; |
5010 | } | |
5011 | ||
5012 | static void | |
5013 | linux_nat_stop (ptid_t ptid) | |
5014 | { | |
5015 | if (non_stop) | |
d90e17a7 | 5016 | iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL); |
4c28f408 PA |
5017 | else |
5018 | linux_ops->to_stop (ptid); | |
5019 | } | |
5020 | ||
d90e17a7 | 5021 | static void |
460014f5 | 5022 | linux_nat_close (void) |
d90e17a7 PA |
5023 | { |
5024 | /* Unregister from the event loop. */ | |
305436e0 PA |
5025 | if (linux_nat_is_async_p ()) |
5026 | linux_nat_async (NULL, 0); | |
d90e17a7 | 5027 | |
d90e17a7 | 5028 | if (linux_ops->to_close) |
460014f5 | 5029 | linux_ops->to_close (); |
d90e17a7 PA |
5030 | } |
5031 | ||
c0694254 PA |
5032 | /* When requests are passed down from the linux-nat layer to the |
5033 | single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are | |
5034 | used. The address space pointer is stored in the inferior object, | |
5035 | but the common code that is passed such ptid can't tell whether | |
5036 | lwpid is a "main" process id or not (it assumes so). We reverse | |
5037 | look up the "main" process id from the lwp here. */ | |
5038 | ||
70221824 | 5039 | static struct address_space * |
c0694254 PA |
5040 | linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid) |
5041 | { | |
5042 | struct lwp_info *lwp; | |
5043 | struct inferior *inf; | |
5044 | int pid; | |
5045 | ||
5046 | pid = GET_LWP (ptid); | |
5047 | if (GET_LWP (ptid) == 0) | |
5048 | { | |
5049 | /* An (lwpid,0,0) ptid. Look up the lwp object to get at the | |
5050 | tgid. */ | |
5051 | lwp = find_lwp_pid (ptid); | |
5052 | pid = GET_PID (lwp->ptid); | |
5053 | } | |
5054 | else | |
5055 | { | |
5056 | /* A (pid,lwpid,0) ptid. */ | |
5057 | pid = GET_PID (ptid); | |
5058 | } | |
5059 | ||
5060 | inf = find_inferior_pid (pid); | |
5061 | gdb_assert (inf != NULL); | |
5062 | return inf->aspace; | |
5063 | } | |
5064 | ||
dc146f7c VP |
5065 | /* Return the cached value of the processor core for thread PTID. */ |
5066 | ||
70221824 | 5067 | static int |
dc146f7c VP |
5068 | linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid) |
5069 | { | |
5070 | struct lwp_info *info = find_lwp_pid (ptid); | |
e0881a8e | 5071 | |
dc146f7c VP |
5072 | if (info) |
5073 | return info->core; | |
5074 | return -1; | |
5075 | } | |
5076 | ||
f973ed9c DJ |
5077 | void |
5078 | linux_nat_add_target (struct target_ops *t) | |
5079 | { | |
f973ed9c DJ |
5080 | /* Save the provided single-threaded target. We save this in a separate |
5081 | variable because another target we've inherited from (e.g. inf-ptrace) | |
5082 | may have saved a pointer to T; we want to use it for the final | |
5083 | process stratum target. */ | |
5084 | linux_ops_saved = *t; | |
5085 | linux_ops = &linux_ops_saved; | |
5086 | ||
5087 | /* Override some methods for multithreading. */ | |
b84876c2 | 5088 | t->to_create_inferior = linux_nat_create_inferior; |
f973ed9c DJ |
5089 | t->to_attach = linux_nat_attach; |
5090 | t->to_detach = linux_nat_detach; | |
5091 | t->to_resume = linux_nat_resume; | |
5092 | t->to_wait = linux_nat_wait; | |
2455069d | 5093 | t->to_pass_signals = linux_nat_pass_signals; |
f973ed9c DJ |
5094 | t->to_xfer_partial = linux_nat_xfer_partial; |
5095 | t->to_kill = linux_nat_kill; | |
5096 | t->to_mourn_inferior = linux_nat_mourn_inferior; | |
5097 | t->to_thread_alive = linux_nat_thread_alive; | |
5098 | t->to_pid_to_str = linux_nat_pid_to_str; | |
4694da01 | 5099 | t->to_thread_name = linux_nat_thread_name; |
f973ed9c | 5100 | t->to_has_thread_control = tc_schedlock; |
c0694254 | 5101 | t->to_thread_address_space = linux_nat_thread_address_space; |
ebec9a0f PA |
5102 | t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint; |
5103 | t->to_stopped_data_address = linux_nat_stopped_data_address; | |
f973ed9c | 5104 | |
b84876c2 PA |
5105 | t->to_can_async_p = linux_nat_can_async_p; |
5106 | t->to_is_async_p = linux_nat_is_async_p; | |
9908b566 | 5107 | t->to_supports_non_stop = linux_nat_supports_non_stop; |
b84876c2 | 5108 | t->to_async = linux_nat_async; |
b84876c2 PA |
5109 | t->to_terminal_inferior = linux_nat_terminal_inferior; |
5110 | t->to_terminal_ours = linux_nat_terminal_ours; | |
d90e17a7 | 5111 | t->to_close = linux_nat_close; |
b84876c2 | 5112 | |
4c28f408 PA |
5113 | /* Methods for non-stop support. */ |
5114 | t->to_stop = linux_nat_stop; | |
5115 | ||
d90e17a7 PA |
5116 | t->to_supports_multi_process = linux_nat_supports_multi_process; |
5117 | ||
03583c20 UW |
5118 | t->to_supports_disable_randomization |
5119 | = linux_nat_supports_disable_randomization; | |
5120 | ||
dc146f7c VP |
5121 | t->to_core_of_thread = linux_nat_core_of_thread; |
5122 | ||
f973ed9c DJ |
5123 | /* We don't change the stratum; this target will sit at |
5124 | process_stratum and thread_db will set at thread_stratum. This | |
5125 | is a little strange, since this is a multi-threaded-capable | |
5126 | target, but we want to be on the stack below thread_db, and we | |
5127 | also want to be used for single-threaded processes. */ | |
5128 | ||
5129 | add_target (t); | |
f973ed9c DJ |
5130 | } |
5131 | ||
9f0bdab8 DJ |
5132 | /* Register a method to call whenever a new thread is attached. */ |
5133 | void | |
7b50312a PA |
5134 | linux_nat_set_new_thread (struct target_ops *t, |
5135 | void (*new_thread) (struct lwp_info *)) | |
9f0bdab8 DJ |
5136 | { |
5137 | /* Save the pointer. We only support a single registered instance | |
5138 | of the GNU/Linux native target, so we do not need to map this to | |
5139 | T. */ | |
5140 | linux_nat_new_thread = new_thread; | |
5141 | } | |
5142 | ||
26cb8b7c PA |
5143 | /* See declaration in linux-nat.h. */ |
5144 | ||
5145 | void | |
5146 | linux_nat_set_new_fork (struct target_ops *t, | |
5147 | linux_nat_new_fork_ftype *new_fork) | |
5148 | { | |
5149 | /* Save the pointer. */ | |
5150 | linux_nat_new_fork = new_fork; | |
5151 | } | |
5152 | ||
5153 | /* See declaration in linux-nat.h. */ | |
5154 | ||
5155 | void | |
5156 | linux_nat_set_forget_process (struct target_ops *t, | |
5157 | linux_nat_forget_process_ftype *fn) | |
5158 | { | |
5159 | /* Save the pointer. */ | |
5160 | linux_nat_forget_process_hook = fn; | |
5161 | } | |
5162 | ||
5163 | /* See declaration in linux-nat.h. */ | |
5164 | ||
5165 | void | |
5166 | linux_nat_forget_process (pid_t pid) | |
5167 | { | |
5168 | if (linux_nat_forget_process_hook != NULL) | |
5169 | linux_nat_forget_process_hook (pid); | |
5170 | } | |
5171 | ||
5b009018 PA |
5172 | /* Register a method that converts a siginfo object between the layout |
5173 | that ptrace returns, and the layout in the architecture of the | |
5174 | inferior. */ | |
5175 | void | |
5176 | linux_nat_set_siginfo_fixup (struct target_ops *t, | |
a5362b9a | 5177 | int (*siginfo_fixup) (siginfo_t *, |
5b009018 PA |
5178 | gdb_byte *, |
5179 | int)) | |
5180 | { | |
5181 | /* Save the pointer. */ | |
5182 | linux_nat_siginfo_fixup = siginfo_fixup; | |
5183 | } | |
5184 | ||
7b50312a PA |
5185 | /* Register a method to call prior to resuming a thread. */ |
5186 | ||
5187 | void | |
5188 | linux_nat_set_prepare_to_resume (struct target_ops *t, | |
5189 | void (*prepare_to_resume) (struct lwp_info *)) | |
5190 | { | |
5191 | /* Save the pointer. */ | |
5192 | linux_nat_prepare_to_resume = prepare_to_resume; | |
5193 | } | |
5194 | ||
f865ee35 JK |
5195 | /* See linux-nat.h. */ |
5196 | ||
5197 | int | |
5198 | linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo) | |
9f0bdab8 | 5199 | { |
da559b09 | 5200 | int pid; |
9f0bdab8 | 5201 | |
da559b09 JK |
5202 | pid = GET_LWP (ptid); |
5203 | if (pid == 0) | |
5204 | pid = GET_PID (ptid); | |
f865ee35 | 5205 | |
da559b09 JK |
5206 | errno = 0; |
5207 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo); | |
5208 | if (errno != 0) | |
5209 | { | |
5210 | memset (siginfo, 0, sizeof (*siginfo)); | |
5211 | return 0; | |
5212 | } | |
f865ee35 | 5213 | return 1; |
9f0bdab8 DJ |
5214 | } |
5215 | ||
2c0b251b PA |
5216 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
5217 | extern initialize_file_ftype _initialize_linux_nat; | |
5218 | ||
d6b0e80f AC |
5219 | void |
5220 | _initialize_linux_nat (void) | |
5221 | { | |
ccce17b0 YQ |
5222 | add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance, |
5223 | &debug_linux_nat, _("\ | |
b84876c2 PA |
5224 | Set debugging of GNU/Linux lwp module."), _("\ |
5225 | Show debugging of GNU/Linux lwp module."), _("\ | |
5226 | Enables printf debugging output."), | |
ccce17b0 YQ |
5227 | NULL, |
5228 | show_debug_linux_nat, | |
5229 | &setdebuglist, &showdebuglist); | |
b84876c2 | 5230 | |
b84876c2 | 5231 | /* Save this mask as the default. */ |
d6b0e80f AC |
5232 | sigprocmask (SIG_SETMASK, NULL, &normal_mask); |
5233 | ||
7feb7d06 PA |
5234 | /* Install a SIGCHLD handler. */ |
5235 | sigchld_action.sa_handler = sigchld_handler; | |
5236 | sigemptyset (&sigchld_action.sa_mask); | |
5237 | sigchld_action.sa_flags = SA_RESTART; | |
b84876c2 PA |
5238 | |
5239 | /* Make it the default. */ | |
7feb7d06 | 5240 | sigaction (SIGCHLD, &sigchld_action, NULL); |
d6b0e80f AC |
5241 | |
5242 | /* Make sure we don't block SIGCHLD during a sigsuspend. */ | |
5243 | sigprocmask (SIG_SETMASK, NULL, &suspend_mask); | |
5244 | sigdelset (&suspend_mask, SIGCHLD); | |
5245 | ||
7feb7d06 | 5246 | sigemptyset (&blocked_mask); |
d6b0e80f AC |
5247 | } |
5248 | \f | |
5249 | ||
5250 | /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to | |
5251 | the GNU/Linux Threads library and therefore doesn't really belong | |
5252 | here. */ | |
5253 | ||
5254 | /* Read variable NAME in the target and return its value if found. | |
5255 | Otherwise return zero. It is assumed that the type of the variable | |
5256 | is `int'. */ | |
5257 | ||
5258 | static int | |
5259 | get_signo (const char *name) | |
5260 | { | |
5261 | struct minimal_symbol *ms; | |
5262 | int signo; | |
5263 | ||
5264 | ms = lookup_minimal_symbol (name, NULL, NULL); | |
5265 | if (ms == NULL) | |
5266 | return 0; | |
5267 | ||
8e70166d | 5268 | if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo, |
d6b0e80f AC |
5269 | sizeof (signo)) != 0) |
5270 | return 0; | |
5271 | ||
5272 | return signo; | |
5273 | } | |
5274 | ||
5275 | /* Return the set of signals used by the threads library in *SET. */ | |
5276 | ||
5277 | void | |
5278 | lin_thread_get_thread_signals (sigset_t *set) | |
5279 | { | |
5280 | struct sigaction action; | |
5281 | int restart, cancel; | |
5282 | ||
b84876c2 | 5283 | sigemptyset (&blocked_mask); |
d6b0e80f AC |
5284 | sigemptyset (set); |
5285 | ||
5286 | restart = get_signo ("__pthread_sig_restart"); | |
17fbb0bd DJ |
5287 | cancel = get_signo ("__pthread_sig_cancel"); |
5288 | ||
5289 | /* LinuxThreads normally uses the first two RT signals, but in some legacy | |
5290 | cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does | |
5291 | not provide any way for the debugger to query the signal numbers - | |
5292 | fortunately they don't change! */ | |
5293 | ||
d6b0e80f | 5294 | if (restart == 0) |
17fbb0bd | 5295 | restart = __SIGRTMIN; |
d6b0e80f | 5296 | |
d6b0e80f | 5297 | if (cancel == 0) |
17fbb0bd | 5298 | cancel = __SIGRTMIN + 1; |
d6b0e80f AC |
5299 | |
5300 | sigaddset (set, restart); | |
5301 | sigaddset (set, cancel); | |
5302 | ||
5303 | /* The GNU/Linux Threads library makes terminating threads send a | |
5304 | special "cancel" signal instead of SIGCHLD. Make sure we catch | |
5305 | those (to prevent them from terminating GDB itself, which is | |
5306 | likely to be their default action) and treat them the same way as | |
5307 | SIGCHLD. */ | |
5308 | ||
5309 | action.sa_handler = sigchld_handler; | |
5310 | sigemptyset (&action.sa_mask); | |
58aecb61 | 5311 | action.sa_flags = SA_RESTART; |
d6b0e80f AC |
5312 | sigaction (cancel, &action, NULL); |
5313 | ||
5314 | /* We block the "cancel" signal throughout this code ... */ | |
5315 | sigaddset (&blocked_mask, cancel); | |
5316 | sigprocmask (SIG_BLOCK, &blocked_mask, NULL); | |
5317 | ||
5318 | /* ... except during a sigsuspend. */ | |
5319 | sigdelset (&suspend_mask, cancel); | |
5320 | } |