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" |
efcbbd14 UW |
70 | |
71 | #ifndef SPUFS_MAGIC | |
72 | #define SPUFS_MAGIC 0x23c9b64e | |
73 | #endif | |
dba24537 | 74 | |
10568435 JK |
75 | #ifdef HAVE_PERSONALITY |
76 | # include <sys/personality.h> | |
77 | # if !HAVE_DECL_ADDR_NO_RANDOMIZE | |
78 | # define ADDR_NO_RANDOMIZE 0x0040000 | |
79 | # endif | |
80 | #endif /* HAVE_PERSONALITY */ | |
81 | ||
1777feb0 | 82 | /* This comment documents high-level logic of this file. |
8a77dff3 VP |
83 | |
84 | Waiting for events in sync mode | |
85 | =============================== | |
86 | ||
87 | When waiting for an event in a specific thread, we just use waitpid, passing | |
88 | the specific pid, and not passing WNOHANG. | |
89 | ||
1777feb0 | 90 | When waiting for an event in all threads, waitpid is not quite good. Prior to |
8a77dff3 | 91 | version 2.4, Linux can either wait for event in main thread, or in secondary |
1777feb0 | 92 | threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might |
8a77dff3 VP |
93 | miss an event. The solution is to use non-blocking waitpid, together with |
94 | sigsuspend. First, we use non-blocking waitpid to get an event in the main | |
1777feb0 | 95 | process, if any. Second, we use non-blocking waitpid with the __WCLONED |
8a77dff3 VP |
96 | flag to check for events in cloned processes. If nothing is found, we use |
97 | sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something | |
98 | happened to a child process -- and SIGCHLD will be delivered both for events | |
99 | in main debugged process and in cloned processes. As soon as we know there's | |
3e43a32a MS |
100 | an event, we get back to calling nonblocking waitpid with and without |
101 | __WCLONED. | |
8a77dff3 VP |
102 | |
103 | Note that SIGCHLD should be blocked between waitpid and sigsuspend calls, | |
1777feb0 | 104 | so that we don't miss a signal. If SIGCHLD arrives in between, when it's |
8a77dff3 VP |
105 | blocked, the signal becomes pending and sigsuspend immediately |
106 | notices it and returns. | |
107 | ||
108 | Waiting for events in async mode | |
109 | ================================ | |
110 | ||
7feb7d06 PA |
111 | In async mode, GDB should always be ready to handle both user input |
112 | and target events, so neither blocking waitpid nor sigsuspend are | |
113 | viable options. Instead, we should asynchronously notify the GDB main | |
114 | event loop whenever there's an unprocessed event from the target. We | |
115 | detect asynchronous target events by handling SIGCHLD signals. To | |
116 | notify the event loop about target events, the self-pipe trick is used | |
117 | --- a pipe is registered as waitable event source in the event loop, | |
118 | the event loop select/poll's on the read end of this pipe (as well on | |
119 | other event sources, e.g., stdin), and the SIGCHLD handler writes a | |
120 | byte to this pipe. This is more portable than relying on | |
121 | pselect/ppoll, since on kernels that lack those syscalls, libc | |
122 | emulates them with select/poll+sigprocmask, and that is racy | |
123 | (a.k.a. plain broken). | |
124 | ||
125 | Obviously, if we fail to notify the event loop if there's a target | |
126 | event, it's bad. OTOH, if we notify the event loop when there's no | |
127 | event from the target, linux_nat_wait will detect that there's no real | |
128 | event to report, and return event of type TARGET_WAITKIND_IGNORE. | |
129 | This is mostly harmless, but it will waste time and is better avoided. | |
130 | ||
131 | The main design point is that every time GDB is outside linux-nat.c, | |
132 | we have a SIGCHLD handler installed that is called when something | |
133 | happens to the target and notifies the GDB event loop. Whenever GDB | |
134 | core decides to handle the event, and calls into linux-nat.c, we | |
135 | process things as in sync mode, except that the we never block in | |
136 | sigsuspend. | |
137 | ||
138 | While processing an event, we may end up momentarily blocked in | |
139 | waitpid calls. Those waitpid calls, while blocking, are guarantied to | |
140 | return quickly. E.g., in all-stop mode, before reporting to the core | |
141 | that an LWP hit a breakpoint, all LWPs are stopped by sending them | |
142 | SIGSTOP, and synchronously waiting for the SIGSTOP to be reported. | |
143 | Note that this is different from blocking indefinitely waiting for the | |
144 | next event --- here, we're already handling an event. | |
8a77dff3 VP |
145 | |
146 | Use of signals | |
147 | ============== | |
148 | ||
149 | We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another | |
150 | signal is not entirely significant; we just need for a signal to be delivered, | |
151 | so that we can intercept it. SIGSTOP's advantage is that it can not be | |
152 | blocked. A disadvantage is that it is not a real-time signal, so it can only | |
153 | be queued once; we do not keep track of other sources of SIGSTOP. | |
154 | ||
155 | Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't | |
156 | use them, because they have special behavior when the signal is generated - | |
157 | not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL | |
158 | kills the entire thread group. | |
159 | ||
160 | A delivered SIGSTOP would stop the entire thread group, not just the thread we | |
161 | tkill'd. But we never let the SIGSTOP be delivered; we always intercept and | |
162 | cancel it (by PTRACE_CONT without passing SIGSTOP). | |
163 | ||
164 | We could use a real-time signal instead. This would solve those problems; we | |
165 | could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB. | |
166 | But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH | |
167 | generates it, and there are races with trying to find a signal that is not | |
168 | blocked. */ | |
a0ef4274 | 169 | |
dba24537 AC |
170 | #ifndef O_LARGEFILE |
171 | #define O_LARGEFILE 0 | |
172 | #endif | |
0274a8ce | 173 | |
ca2163eb PA |
174 | /* Unlike other extended result codes, WSTOPSIG (status) on |
175 | PTRACE_O_TRACESYSGOOD syscall events doesn't return SIGTRAP, but | |
176 | instead SIGTRAP with bit 7 set. */ | |
177 | #define SYSCALL_SIGTRAP (SIGTRAP | 0x80) | |
178 | ||
10d6c8cd DJ |
179 | /* The single-threaded native GNU/Linux target_ops. We save a pointer for |
180 | the use of the multi-threaded target. */ | |
181 | static struct target_ops *linux_ops; | |
f973ed9c | 182 | static struct target_ops linux_ops_saved; |
10d6c8cd | 183 | |
9f0bdab8 | 184 | /* The method to call, if any, when a new thread is attached. */ |
7b50312a PA |
185 | static void (*linux_nat_new_thread) (struct lwp_info *); |
186 | ||
26cb8b7c PA |
187 | /* The method to call, if any, when a new fork is attached. */ |
188 | static linux_nat_new_fork_ftype *linux_nat_new_fork; | |
189 | ||
190 | /* The method to call, if any, when a process is no longer | |
191 | attached. */ | |
192 | static linux_nat_forget_process_ftype *linux_nat_forget_process_hook; | |
193 | ||
7b50312a PA |
194 | /* Hook to call prior to resuming a thread. */ |
195 | static void (*linux_nat_prepare_to_resume) (struct lwp_info *); | |
9f0bdab8 | 196 | |
5b009018 PA |
197 | /* The method to call, if any, when the siginfo object needs to be |
198 | converted between the layout returned by ptrace, and the layout in | |
199 | the architecture of the inferior. */ | |
a5362b9a | 200 | static int (*linux_nat_siginfo_fixup) (siginfo_t *, |
5b009018 PA |
201 | gdb_byte *, |
202 | int); | |
203 | ||
ac264b3b MS |
204 | /* The saved to_xfer_partial method, inherited from inf-ptrace.c. |
205 | Called by our to_xfer_partial. */ | |
206 | static LONGEST (*super_xfer_partial) (struct target_ops *, | |
207 | enum target_object, | |
208 | const char *, gdb_byte *, | |
209 | const gdb_byte *, | |
10d6c8cd DJ |
210 | ULONGEST, LONGEST); |
211 | ||
ccce17b0 | 212 | static unsigned int debug_linux_nat; |
920d2a44 AC |
213 | static void |
214 | show_debug_linux_nat (struct ui_file *file, int from_tty, | |
215 | struct cmd_list_element *c, const char *value) | |
216 | { | |
217 | fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"), | |
218 | value); | |
219 | } | |
d6b0e80f | 220 | |
ae087d01 DJ |
221 | struct simple_pid_list |
222 | { | |
223 | int pid; | |
3d799a95 | 224 | int status; |
ae087d01 DJ |
225 | struct simple_pid_list *next; |
226 | }; | |
227 | struct simple_pid_list *stopped_pids; | |
228 | ||
3993f6b1 DJ |
229 | /* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACEFORK |
230 | can not be used, 1 if it can. */ | |
231 | ||
232 | static int linux_supports_tracefork_flag = -1; | |
233 | ||
3e43a32a MS |
234 | /* This variable is a tri-state flag: -1 for unknown, 0 if |
235 | PTRACE_O_TRACESYSGOOD can not be used, 1 if it can. */ | |
a96d9b2e SDJ |
236 | |
237 | static int linux_supports_tracesysgood_flag = -1; | |
238 | ||
9016a515 DJ |
239 | /* If we have PTRACE_O_TRACEFORK, this flag indicates whether we also have |
240 | PTRACE_O_TRACEVFORKDONE. */ | |
241 | ||
242 | static int linux_supports_tracevforkdone_flag = -1; | |
243 | ||
a96d9b2e SDJ |
244 | /* Stores the current used ptrace() options. */ |
245 | static int current_ptrace_options = 0; | |
246 | ||
3dd5b83d PA |
247 | /* Async mode support. */ |
248 | ||
b84876c2 PA |
249 | /* The read/write ends of the pipe registered as waitable file in the |
250 | event loop. */ | |
251 | static int linux_nat_event_pipe[2] = { -1, -1 }; | |
252 | ||
7feb7d06 | 253 | /* Flush the event pipe. */ |
b84876c2 | 254 | |
7feb7d06 PA |
255 | static void |
256 | async_file_flush (void) | |
b84876c2 | 257 | { |
7feb7d06 PA |
258 | int ret; |
259 | char buf; | |
b84876c2 | 260 | |
7feb7d06 | 261 | do |
b84876c2 | 262 | { |
7feb7d06 | 263 | ret = read (linux_nat_event_pipe[0], &buf, 1); |
b84876c2 | 264 | } |
7feb7d06 | 265 | while (ret >= 0 || (ret == -1 && errno == EINTR)); |
b84876c2 PA |
266 | } |
267 | ||
7feb7d06 PA |
268 | /* Put something (anything, doesn't matter what, or how much) in event |
269 | pipe, so that the select/poll in the event-loop realizes we have | |
270 | something to process. */ | |
252fbfc8 | 271 | |
b84876c2 | 272 | static void |
7feb7d06 | 273 | async_file_mark (void) |
b84876c2 | 274 | { |
7feb7d06 | 275 | int ret; |
b84876c2 | 276 | |
7feb7d06 PA |
277 | /* It doesn't really matter what the pipe contains, as long we end |
278 | up with something in it. Might as well flush the previous | |
279 | left-overs. */ | |
280 | async_file_flush (); | |
b84876c2 | 281 | |
7feb7d06 | 282 | do |
b84876c2 | 283 | { |
7feb7d06 | 284 | ret = write (linux_nat_event_pipe[1], "+", 1); |
b84876c2 | 285 | } |
7feb7d06 | 286 | while (ret == -1 && errno == EINTR); |
b84876c2 | 287 | |
7feb7d06 PA |
288 | /* Ignore EAGAIN. If the pipe is full, the event loop will already |
289 | be awakened anyway. */ | |
b84876c2 PA |
290 | } |
291 | ||
7feb7d06 | 292 | static void linux_nat_async (void (*callback) |
3e43a32a MS |
293 | (enum inferior_event_type event_type, |
294 | void *context), | |
7feb7d06 | 295 | void *context); |
7feb7d06 PA |
296 | static int kill_lwp (int lwpid, int signo); |
297 | ||
298 | static int stop_callback (struct lwp_info *lp, void *data); | |
299 | ||
300 | static void block_child_signals (sigset_t *prev_mask); | |
301 | static void restore_child_signals_mask (sigset_t *prev_mask); | |
2277426b PA |
302 | |
303 | struct lwp_info; | |
304 | static struct lwp_info *add_lwp (ptid_t ptid); | |
305 | static void purge_lwp_list (int pid); | |
4403d8e9 | 306 | static void delete_lwp (ptid_t ptid); |
2277426b PA |
307 | static struct lwp_info *find_lwp_pid (ptid_t ptid); |
308 | ||
ae087d01 DJ |
309 | \f |
310 | /* Trivial list manipulation functions to keep track of a list of | |
311 | new stopped processes. */ | |
312 | static void | |
3d799a95 | 313 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
ae087d01 DJ |
314 | { |
315 | struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list)); | |
e0881a8e | 316 | |
ae087d01 | 317 | new_pid->pid = pid; |
3d799a95 | 318 | new_pid->status = status; |
ae087d01 DJ |
319 | new_pid->next = *listp; |
320 | *listp = new_pid; | |
321 | } | |
322 | ||
84636d28 PA |
323 | static int |
324 | in_pid_list_p (struct simple_pid_list *list, int pid) | |
325 | { | |
326 | struct simple_pid_list *p; | |
327 | ||
328 | for (p = list; p != NULL; p = p->next) | |
329 | if (p->pid == pid) | |
330 | return 1; | |
331 | return 0; | |
332 | } | |
333 | ||
ae087d01 | 334 | static int |
46a96992 | 335 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
ae087d01 DJ |
336 | { |
337 | struct simple_pid_list **p; | |
338 | ||
339 | for (p = listp; *p != NULL; p = &(*p)->next) | |
340 | if ((*p)->pid == pid) | |
341 | { | |
342 | struct simple_pid_list *next = (*p)->next; | |
e0881a8e | 343 | |
46a96992 | 344 | *statusp = (*p)->status; |
ae087d01 DJ |
345 | xfree (*p); |
346 | *p = next; | |
347 | return 1; | |
348 | } | |
349 | return 0; | |
350 | } | |
351 | ||
3993f6b1 DJ |
352 | \f |
353 | /* A helper function for linux_test_for_tracefork, called after fork (). */ | |
354 | ||
355 | static void | |
356 | linux_tracefork_child (void) | |
357 | { | |
3993f6b1 DJ |
358 | ptrace (PTRACE_TRACEME, 0, 0, 0); |
359 | kill (getpid (), SIGSTOP); | |
360 | fork (); | |
48bb3cce | 361 | _exit (0); |
3993f6b1 DJ |
362 | } |
363 | ||
7feb7d06 | 364 | /* Wrapper function for waitpid which handles EINTR. */ |
b957e937 DJ |
365 | |
366 | static int | |
46a96992 | 367 | my_waitpid (int pid, int *statusp, int flags) |
b957e937 DJ |
368 | { |
369 | int ret; | |
b84876c2 | 370 | |
b957e937 DJ |
371 | do |
372 | { | |
46a96992 | 373 | ret = waitpid (pid, statusp, flags); |
b957e937 DJ |
374 | } |
375 | while (ret == -1 && errno == EINTR); | |
376 | ||
377 | return ret; | |
378 | } | |
379 | ||
380 | /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. | |
381 | ||
382 | First, we try to enable fork tracing on ORIGINAL_PID. If this fails, | |
383 | we know that the feature is not available. This may change the tracing | |
384 | options for ORIGINAL_PID, but we'll be setting them shortly anyway. | |
385 | ||
386 | However, if it succeeds, we don't know for sure that the feature is | |
387 | available; old versions of PTRACE_SETOPTIONS ignored unknown options. We | |
3993f6b1 | 388 | create a child process, attach to it, use PTRACE_SETOPTIONS to enable |
b957e937 DJ |
389 | fork tracing, and let it fork. If the process exits, we assume that we |
390 | can't use TRACEFORK; if we get the fork notification, and we can extract | |
391 | the new child's PID, then we assume that we can. */ | |
3993f6b1 DJ |
392 | |
393 | static void | |
b957e937 | 394 | linux_test_for_tracefork (int original_pid) |
3993f6b1 DJ |
395 | { |
396 | int child_pid, ret, status; | |
397 | long second_pid; | |
7feb7d06 | 398 | sigset_t prev_mask; |
4c28f408 | 399 | |
7feb7d06 PA |
400 | /* We don't want those ptrace calls to be interrupted. */ |
401 | block_child_signals (&prev_mask); | |
3993f6b1 | 402 | |
b957e937 DJ |
403 | linux_supports_tracefork_flag = 0; |
404 | linux_supports_tracevforkdone_flag = 0; | |
405 | ||
406 | ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACEFORK); | |
407 | if (ret != 0) | |
7feb7d06 PA |
408 | { |
409 | restore_child_signals_mask (&prev_mask); | |
410 | return; | |
411 | } | |
b957e937 | 412 | |
3993f6b1 DJ |
413 | child_pid = fork (); |
414 | if (child_pid == -1) | |
e2e0b3e5 | 415 | perror_with_name (("fork")); |
3993f6b1 DJ |
416 | |
417 | if (child_pid == 0) | |
418 | linux_tracefork_child (); | |
419 | ||
b957e937 | 420 | ret = my_waitpid (child_pid, &status, 0); |
3993f6b1 | 421 | if (ret == -1) |
e2e0b3e5 | 422 | perror_with_name (("waitpid")); |
3993f6b1 | 423 | else if (ret != child_pid) |
8a3fe4f8 | 424 | error (_("linux_test_for_tracefork: waitpid: unexpected result %d."), ret); |
3993f6b1 | 425 | if (! WIFSTOPPED (status)) |
3e43a32a MS |
426 | error (_("linux_test_for_tracefork: waitpid: unexpected status %d."), |
427 | status); | |
3993f6b1 | 428 | |
3993f6b1 DJ |
429 | ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK); |
430 | if (ret != 0) | |
431 | { | |
b957e937 DJ |
432 | ret = ptrace (PTRACE_KILL, child_pid, 0, 0); |
433 | if (ret != 0) | |
434 | { | |
8a3fe4f8 | 435 | warning (_("linux_test_for_tracefork: failed to kill child")); |
7feb7d06 | 436 | restore_child_signals_mask (&prev_mask); |
b957e937 DJ |
437 | return; |
438 | } | |
439 | ||
440 | ret = my_waitpid (child_pid, &status, 0); | |
441 | if (ret != child_pid) | |
3e43a32a MS |
442 | warning (_("linux_test_for_tracefork: failed " |
443 | "to wait for killed child")); | |
b957e937 | 444 | else if (!WIFSIGNALED (status)) |
3e43a32a MS |
445 | warning (_("linux_test_for_tracefork: unexpected " |
446 | "wait status 0x%x from killed child"), status); | |
b957e937 | 447 | |
7feb7d06 | 448 | restore_child_signals_mask (&prev_mask); |
3993f6b1 DJ |
449 | return; |
450 | } | |
451 | ||
9016a515 DJ |
452 | /* Check whether PTRACE_O_TRACEVFORKDONE is available. */ |
453 | ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, | |
454 | PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORKDONE); | |
455 | linux_supports_tracevforkdone_flag = (ret == 0); | |
456 | ||
b957e937 DJ |
457 | ret = ptrace (PTRACE_CONT, child_pid, 0, 0); |
458 | if (ret != 0) | |
8a3fe4f8 | 459 | warning (_("linux_test_for_tracefork: failed to resume child")); |
b957e937 DJ |
460 | |
461 | ret = my_waitpid (child_pid, &status, 0); | |
462 | ||
3993f6b1 DJ |
463 | if (ret == child_pid && WIFSTOPPED (status) |
464 | && status >> 16 == PTRACE_EVENT_FORK) | |
465 | { | |
466 | second_pid = 0; | |
467 | ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid); | |
468 | if (ret == 0 && second_pid != 0) | |
469 | { | |
470 | int second_status; | |
471 | ||
472 | linux_supports_tracefork_flag = 1; | |
b957e937 DJ |
473 | my_waitpid (second_pid, &second_status, 0); |
474 | ret = ptrace (PTRACE_KILL, second_pid, 0, 0); | |
475 | if (ret != 0) | |
3e43a32a MS |
476 | warning (_("linux_test_for_tracefork: " |
477 | "failed to kill second child")); | |
97725dc4 | 478 | my_waitpid (second_pid, &status, 0); |
3993f6b1 DJ |
479 | } |
480 | } | |
b957e937 | 481 | else |
8a3fe4f8 AC |
482 | warning (_("linux_test_for_tracefork: unexpected result from waitpid " |
483 | "(%d, status 0x%x)"), ret, status); | |
3993f6b1 | 484 | |
b957e937 DJ |
485 | ret = ptrace (PTRACE_KILL, child_pid, 0, 0); |
486 | if (ret != 0) | |
8a3fe4f8 | 487 | warning (_("linux_test_for_tracefork: failed to kill child")); |
b957e937 | 488 | my_waitpid (child_pid, &status, 0); |
4c28f408 | 489 | |
7feb7d06 | 490 | restore_child_signals_mask (&prev_mask); |
3993f6b1 DJ |
491 | } |
492 | ||
a96d9b2e SDJ |
493 | /* Determine if PTRACE_O_TRACESYSGOOD can be used to follow syscalls. |
494 | ||
495 | We try to enable syscall tracing on ORIGINAL_PID. If this fails, | |
496 | we know that the feature is not available. This may change the tracing | |
497 | options for ORIGINAL_PID, but we'll be setting them shortly anyway. */ | |
498 | ||
499 | static void | |
500 | linux_test_for_tracesysgood (int original_pid) | |
501 | { | |
502 | int ret; | |
503 | sigset_t prev_mask; | |
504 | ||
505 | /* We don't want those ptrace calls to be interrupted. */ | |
506 | block_child_signals (&prev_mask); | |
507 | ||
508 | linux_supports_tracesysgood_flag = 0; | |
509 | ||
510 | ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACESYSGOOD); | |
511 | if (ret != 0) | |
512 | goto out; | |
513 | ||
514 | linux_supports_tracesysgood_flag = 1; | |
515 | out: | |
516 | restore_child_signals_mask (&prev_mask); | |
517 | } | |
518 | ||
519 | /* Determine wether we support PTRACE_O_TRACESYSGOOD option available. | |
520 | This function also sets linux_supports_tracesysgood_flag. */ | |
521 | ||
522 | static int | |
523 | linux_supports_tracesysgood (int pid) | |
524 | { | |
525 | if (linux_supports_tracesysgood_flag == -1) | |
526 | linux_test_for_tracesysgood (pid); | |
527 | return linux_supports_tracesysgood_flag; | |
528 | } | |
529 | ||
3993f6b1 DJ |
530 | /* Return non-zero iff we have tracefork functionality available. |
531 | This function also sets linux_supports_tracefork_flag. */ | |
532 | ||
533 | static int | |
b957e937 | 534 | linux_supports_tracefork (int pid) |
3993f6b1 DJ |
535 | { |
536 | if (linux_supports_tracefork_flag == -1) | |
b957e937 | 537 | linux_test_for_tracefork (pid); |
3993f6b1 DJ |
538 | return linux_supports_tracefork_flag; |
539 | } | |
540 | ||
9016a515 | 541 | static int |
b957e937 | 542 | linux_supports_tracevforkdone (int pid) |
9016a515 DJ |
543 | { |
544 | if (linux_supports_tracefork_flag == -1) | |
b957e937 | 545 | linux_test_for_tracefork (pid); |
9016a515 DJ |
546 | return linux_supports_tracevforkdone_flag; |
547 | } | |
548 | ||
a96d9b2e SDJ |
549 | static void |
550 | linux_enable_tracesysgood (ptid_t ptid) | |
551 | { | |
552 | int pid = ptid_get_lwp (ptid); | |
553 | ||
554 | if (pid == 0) | |
555 | pid = ptid_get_pid (ptid); | |
556 | ||
557 | if (linux_supports_tracesysgood (pid) == 0) | |
558 | return; | |
559 | ||
560 | current_ptrace_options |= PTRACE_O_TRACESYSGOOD; | |
561 | ||
562 | ptrace (PTRACE_SETOPTIONS, pid, 0, current_ptrace_options); | |
563 | } | |
564 | ||
3993f6b1 | 565 | \f |
4de4c07c DJ |
566 | void |
567 | linux_enable_event_reporting (ptid_t ptid) | |
568 | { | |
d3587048 | 569 | int pid = ptid_get_lwp (ptid); |
4de4c07c | 570 | |
d3587048 DJ |
571 | if (pid == 0) |
572 | pid = ptid_get_pid (ptid); | |
573 | ||
b957e937 | 574 | if (! linux_supports_tracefork (pid)) |
4de4c07c DJ |
575 | return; |
576 | ||
a96d9b2e SDJ |
577 | current_ptrace_options |= PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK |
578 | | PTRACE_O_TRACEEXEC | PTRACE_O_TRACECLONE; | |
579 | ||
b957e937 | 580 | if (linux_supports_tracevforkdone (pid)) |
a96d9b2e | 581 | current_ptrace_options |= PTRACE_O_TRACEVFORKDONE; |
9016a515 DJ |
582 | |
583 | /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support | |
584 | read-only process state. */ | |
4de4c07c | 585 | |
a96d9b2e | 586 | ptrace (PTRACE_SETOPTIONS, pid, 0, current_ptrace_options); |
4de4c07c DJ |
587 | } |
588 | ||
6d8fd2b7 UW |
589 | static void |
590 | linux_child_post_attach (int pid) | |
4de4c07c DJ |
591 | { |
592 | linux_enable_event_reporting (pid_to_ptid (pid)); | |
a96d9b2e | 593 | linux_enable_tracesysgood (pid_to_ptid (pid)); |
aa7c7447 | 594 | linux_ptrace_init_warnings (); |
4de4c07c DJ |
595 | } |
596 | ||
10d6c8cd | 597 | static void |
4de4c07c DJ |
598 | linux_child_post_startup_inferior (ptid_t ptid) |
599 | { | |
600 | linux_enable_event_reporting (ptid); | |
a96d9b2e | 601 | linux_enable_tracesysgood (ptid); |
aa7c7447 | 602 | linux_ptrace_init_warnings (); |
4de4c07c DJ |
603 | } |
604 | ||
4403d8e9 JK |
605 | /* Return the number of known LWPs in the tgid given by PID. */ |
606 | ||
607 | static int | |
608 | num_lwps (int pid) | |
609 | { | |
610 | int count = 0; | |
611 | struct lwp_info *lp; | |
612 | ||
613 | for (lp = lwp_list; lp; lp = lp->next) | |
614 | if (ptid_get_pid (lp->ptid) == pid) | |
615 | count++; | |
616 | ||
617 | return count; | |
618 | } | |
619 | ||
620 | /* Call delete_lwp with prototype compatible for make_cleanup. */ | |
621 | ||
622 | static void | |
623 | delete_lwp_cleanup (void *lp_voidp) | |
624 | { | |
625 | struct lwp_info *lp = lp_voidp; | |
626 | ||
627 | delete_lwp (lp->ptid); | |
628 | } | |
629 | ||
6d8fd2b7 UW |
630 | static int |
631 | linux_child_follow_fork (struct target_ops *ops, int follow_child) | |
3993f6b1 | 632 | { |
7feb7d06 | 633 | sigset_t prev_mask; |
9016a515 | 634 | int has_vforked; |
4de4c07c DJ |
635 | int parent_pid, child_pid; |
636 | ||
7feb7d06 | 637 | block_child_signals (&prev_mask); |
b84876c2 | 638 | |
e58b0e63 PA |
639 | has_vforked = (inferior_thread ()->pending_follow.kind |
640 | == TARGET_WAITKIND_VFORKED); | |
641 | parent_pid = ptid_get_lwp (inferior_ptid); | |
d3587048 | 642 | if (parent_pid == 0) |
e58b0e63 PA |
643 | parent_pid = ptid_get_pid (inferior_ptid); |
644 | child_pid = PIDGET (inferior_thread ()->pending_follow.value.related_pid); | |
4de4c07c | 645 | |
2277426b PA |
646 | if (!detach_fork) |
647 | linux_enable_event_reporting (pid_to_ptid (child_pid)); | |
648 | ||
6c95b8df PA |
649 | if (has_vforked |
650 | && !non_stop /* Non-stop always resumes both branches. */ | |
651 | && (!target_is_async_p () || sync_execution) | |
652 | && !(follow_child || detach_fork || sched_multi)) | |
653 | { | |
654 | /* The parent stays blocked inside the vfork syscall until the | |
655 | child execs or exits. If we don't let the child run, then | |
656 | the parent stays blocked. If we're telling the parent to run | |
657 | in the foreground, the user will not be able to ctrl-c to get | |
658 | back the terminal, effectively hanging the debug session. */ | |
ac74f770 MS |
659 | fprintf_filtered (gdb_stderr, _("\ |
660 | Can not resume the parent process over vfork in the foreground while\n\ | |
661 | holding the child stopped. Try \"set detach-on-fork\" or \ | |
662 | \"set schedule-multiple\".\n")); | |
663 | /* FIXME output string > 80 columns. */ | |
6c95b8df PA |
664 | return 1; |
665 | } | |
666 | ||
4de4c07c DJ |
667 | if (! follow_child) |
668 | { | |
6c95b8df | 669 | struct lwp_info *child_lp = NULL; |
4de4c07c | 670 | |
1777feb0 | 671 | /* We're already attached to the parent, by default. */ |
4de4c07c | 672 | |
ac264b3b MS |
673 | /* Detach new forked process? */ |
674 | if (detach_fork) | |
f75c00e4 | 675 | { |
4403d8e9 JK |
676 | struct cleanup *old_chain; |
677 | ||
6c95b8df PA |
678 | /* Before detaching from the child, remove all breakpoints |
679 | from it. If we forked, then this has already been taken | |
680 | care of by infrun.c. If we vforked however, any | |
681 | breakpoint inserted in the parent is visible in the | |
682 | child, even those added while stopped in a vfork | |
683 | catchpoint. This will remove the breakpoints from the | |
684 | parent also, but they'll be reinserted below. */ | |
685 | if (has_vforked) | |
686 | { | |
687 | /* keep breakpoints list in sync. */ | |
688 | remove_breakpoints_pid (GET_PID (inferior_ptid)); | |
689 | } | |
690 | ||
e85a822c | 691 | if (info_verbose || debug_linux_nat) |
ac264b3b MS |
692 | { |
693 | target_terminal_ours (); | |
694 | fprintf_filtered (gdb_stdlog, | |
3e43a32a MS |
695 | "Detaching after fork from " |
696 | "child process %d.\n", | |
ac264b3b MS |
697 | child_pid); |
698 | } | |
4de4c07c | 699 | |
4403d8e9 JK |
700 | old_chain = save_inferior_ptid (); |
701 | inferior_ptid = ptid_build (child_pid, child_pid, 0); | |
702 | ||
703 | child_lp = add_lwp (inferior_ptid); | |
704 | child_lp->stopped = 1; | |
705 | child_lp->last_resume_kind = resume_stop; | |
706 | make_cleanup (delete_lwp_cleanup, child_lp); | |
707 | ||
4403d8e9 JK |
708 | if (linux_nat_prepare_to_resume != NULL) |
709 | linux_nat_prepare_to_resume (child_lp); | |
ac264b3b | 710 | ptrace (PTRACE_DETACH, child_pid, 0, 0); |
4403d8e9 JK |
711 | |
712 | do_cleanups (old_chain); | |
ac264b3b MS |
713 | } |
714 | else | |
715 | { | |
77435e4c | 716 | struct inferior *parent_inf, *child_inf; |
2277426b | 717 | struct cleanup *old_chain; |
7f9f62ba PA |
718 | |
719 | /* Add process to GDB's tables. */ | |
77435e4c PA |
720 | child_inf = add_inferior (child_pid); |
721 | ||
e58b0e63 | 722 | parent_inf = current_inferior (); |
77435e4c | 723 | child_inf->attach_flag = parent_inf->attach_flag; |
191c4426 | 724 | copy_terminal_info (child_inf, parent_inf); |
6ecd4729 PA |
725 | child_inf->gdbarch = parent_inf->gdbarch; |
726 | copy_inferior_target_desc_info (child_inf, parent_inf); | |
7f9f62ba | 727 | |
2277426b | 728 | old_chain = save_inferior_ptid (); |
6c95b8df | 729 | save_current_program_space (); |
2277426b PA |
730 | |
731 | inferior_ptid = ptid_build (child_pid, child_pid, 0); | |
732 | add_thread (inferior_ptid); | |
6c95b8df PA |
733 | child_lp = add_lwp (inferior_ptid); |
734 | child_lp->stopped = 1; | |
25289eb2 | 735 | child_lp->last_resume_kind = resume_stop; |
7dcd53a0 | 736 | child_inf->symfile_flags = SYMFILE_NO_READ; |
2277426b | 737 | |
6c95b8df PA |
738 | /* If this is a vfork child, then the address-space is |
739 | shared with the parent. */ | |
740 | if (has_vforked) | |
741 | { | |
742 | child_inf->pspace = parent_inf->pspace; | |
743 | child_inf->aspace = parent_inf->aspace; | |
744 | ||
745 | /* The parent will be frozen until the child is done | |
746 | with the shared region. Keep track of the | |
747 | parent. */ | |
748 | child_inf->vfork_parent = parent_inf; | |
749 | child_inf->pending_detach = 0; | |
750 | parent_inf->vfork_child = child_inf; | |
751 | parent_inf->pending_detach = 0; | |
752 | } | |
753 | else | |
754 | { | |
755 | child_inf->aspace = new_address_space (); | |
756 | child_inf->pspace = add_program_space (child_inf->aspace); | |
757 | child_inf->removable = 1; | |
758 | set_current_program_space (child_inf->pspace); | |
759 | clone_program_space (child_inf->pspace, parent_inf->pspace); | |
760 | ||
761 | /* Let the shared library layer (solib-svr4) learn about | |
762 | this new process, relocate the cloned exec, pull in | |
763 | shared libraries, and install the solib event | |
764 | breakpoint. If a "cloned-VM" event was propagated | |
765 | better throughout the core, this wouldn't be | |
766 | required. */ | |
268a4a75 | 767 | solib_create_inferior_hook (0); |
6c95b8df PA |
768 | } |
769 | ||
770 | /* Let the thread_db layer learn about this new process. */ | |
2277426b PA |
771 | check_for_thread_db (); |
772 | ||
773 | do_cleanups (old_chain); | |
ac264b3b | 774 | } |
9016a515 DJ |
775 | |
776 | if (has_vforked) | |
777 | { | |
3ced3da4 | 778 | struct lwp_info *parent_lp; |
6c95b8df PA |
779 | struct inferior *parent_inf; |
780 | ||
781 | parent_inf = current_inferior (); | |
782 | ||
783 | /* If we detached from the child, then we have to be careful | |
784 | to not insert breakpoints in the parent until the child | |
785 | is done with the shared memory region. However, if we're | |
786 | staying attached to the child, then we can and should | |
787 | insert breakpoints, so that we can debug it. A | |
788 | subsequent child exec or exit is enough to know when does | |
789 | the child stops using the parent's address space. */ | |
790 | parent_inf->waiting_for_vfork_done = detach_fork; | |
56710373 | 791 | parent_inf->pspace->breakpoints_not_allowed = detach_fork; |
6c95b8df | 792 | |
3ced3da4 | 793 | parent_lp = find_lwp_pid (pid_to_ptid (parent_pid)); |
b957e937 | 794 | gdb_assert (linux_supports_tracefork_flag >= 0); |
3ced3da4 | 795 | |
b957e937 | 796 | if (linux_supports_tracevforkdone (0)) |
9016a515 | 797 | { |
6c95b8df PA |
798 | if (debug_linux_nat) |
799 | fprintf_unfiltered (gdb_stdlog, | |
800 | "LCFF: waiting for VFORK_DONE on %d\n", | |
801 | parent_pid); | |
3ced3da4 | 802 | parent_lp->stopped = 1; |
9016a515 | 803 | |
6c95b8df PA |
804 | /* We'll handle the VFORK_DONE event like any other |
805 | event, in target_wait. */ | |
9016a515 DJ |
806 | } |
807 | else | |
808 | { | |
809 | /* We can't insert breakpoints until the child has | |
810 | finished with the shared memory region. We need to | |
811 | wait until that happens. Ideal would be to just | |
812 | call: | |
813 | - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0); | |
814 | - waitpid (parent_pid, &status, __WALL); | |
815 | However, most architectures can't handle a syscall | |
816 | being traced on the way out if it wasn't traced on | |
817 | the way in. | |
818 | ||
819 | We might also think to loop, continuing the child | |
820 | until it exits or gets a SIGTRAP. One problem is | |
821 | that the child might call ptrace with PTRACE_TRACEME. | |
822 | ||
823 | There's no simple and reliable way to figure out when | |
824 | the vforked child will be done with its copy of the | |
825 | shared memory. We could step it out of the syscall, | |
826 | two instructions, let it go, and then single-step the | |
827 | parent once. When we have hardware single-step, this | |
828 | would work; with software single-step it could still | |
829 | be made to work but we'd have to be able to insert | |
830 | single-step breakpoints in the child, and we'd have | |
831 | to insert -just- the single-step breakpoint in the | |
832 | parent. Very awkward. | |
833 | ||
834 | In the end, the best we can do is to make sure it | |
835 | runs for a little while. Hopefully it will be out of | |
836 | range of any breakpoints we reinsert. Usually this | |
837 | is only the single-step breakpoint at vfork's return | |
838 | point. */ | |
839 | ||
6c95b8df PA |
840 | if (debug_linux_nat) |
841 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
842 | "LCFF: no VFORK_DONE " |
843 | "support, sleeping a bit\n"); | |
6c95b8df | 844 | |
9016a515 | 845 | usleep (10000); |
9016a515 | 846 | |
6c95b8df PA |
847 | /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event, |
848 | and leave it pending. The next linux_nat_resume call | |
849 | will notice a pending event, and bypasses actually | |
850 | resuming the inferior. */ | |
3ced3da4 PA |
851 | parent_lp->status = 0; |
852 | parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE; | |
853 | parent_lp->stopped = 1; | |
6c95b8df PA |
854 | |
855 | /* If we're in async mode, need to tell the event loop | |
856 | there's something here to process. */ | |
857 | if (target_can_async_p ()) | |
858 | async_file_mark (); | |
859 | } | |
9016a515 | 860 | } |
4de4c07c | 861 | } |
3993f6b1 | 862 | else |
4de4c07c | 863 | { |
77435e4c | 864 | struct inferior *parent_inf, *child_inf; |
3ced3da4 | 865 | struct lwp_info *child_lp; |
6c95b8df | 866 | struct program_space *parent_pspace; |
4de4c07c | 867 | |
e85a822c | 868 | if (info_verbose || debug_linux_nat) |
f75c00e4 DJ |
869 | { |
870 | target_terminal_ours (); | |
6c95b8df | 871 | if (has_vforked) |
3e43a32a MS |
872 | fprintf_filtered (gdb_stdlog, |
873 | _("Attaching after process %d " | |
874 | "vfork to child process %d.\n"), | |
6c95b8df PA |
875 | parent_pid, child_pid); |
876 | else | |
3e43a32a MS |
877 | fprintf_filtered (gdb_stdlog, |
878 | _("Attaching after process %d " | |
879 | "fork to child process %d.\n"), | |
6c95b8df | 880 | parent_pid, child_pid); |
f75c00e4 | 881 | } |
4de4c07c | 882 | |
7a7d3353 PA |
883 | /* Add the new inferior first, so that the target_detach below |
884 | doesn't unpush the target. */ | |
885 | ||
77435e4c PA |
886 | child_inf = add_inferior (child_pid); |
887 | ||
e58b0e63 | 888 | parent_inf = current_inferior (); |
77435e4c | 889 | child_inf->attach_flag = parent_inf->attach_flag; |
191c4426 | 890 | copy_terminal_info (child_inf, parent_inf); |
6ecd4729 PA |
891 | child_inf->gdbarch = parent_inf->gdbarch; |
892 | copy_inferior_target_desc_info (child_inf, parent_inf); | |
7a7d3353 | 893 | |
6c95b8df | 894 | parent_pspace = parent_inf->pspace; |
9016a515 | 895 | |
6c95b8df PA |
896 | /* If we're vforking, we want to hold on to the parent until the |
897 | child exits or execs. At child exec or exit time we can | |
898 | remove the old breakpoints from the parent and detach or | |
899 | resume debugging it. Otherwise, detach the parent now; we'll | |
900 | want to reuse it's program/address spaces, but we can't set | |
901 | them to the child before removing breakpoints from the | |
902 | parent, otherwise, the breakpoints module could decide to | |
903 | remove breakpoints from the wrong process (since they'd be | |
904 | assigned to the same address space). */ | |
9016a515 DJ |
905 | |
906 | if (has_vforked) | |
7f9f62ba | 907 | { |
6c95b8df PA |
908 | gdb_assert (child_inf->vfork_parent == NULL); |
909 | gdb_assert (parent_inf->vfork_child == NULL); | |
910 | child_inf->vfork_parent = parent_inf; | |
911 | child_inf->pending_detach = 0; | |
912 | parent_inf->vfork_child = child_inf; | |
913 | parent_inf->pending_detach = detach_fork; | |
914 | parent_inf->waiting_for_vfork_done = 0; | |
ac264b3b | 915 | } |
2277426b | 916 | else if (detach_fork) |
b84876c2 | 917 | target_detach (NULL, 0); |
4de4c07c | 918 | |
6c95b8df PA |
919 | /* Note that the detach above makes PARENT_INF dangling. */ |
920 | ||
921 | /* Add the child thread to the appropriate lists, and switch to | |
922 | this new thread, before cloning the program space, and | |
923 | informing the solib layer about this new process. */ | |
924 | ||
9f0bdab8 | 925 | inferior_ptid = ptid_build (child_pid, child_pid, 0); |
2277426b | 926 | add_thread (inferior_ptid); |
3ced3da4 PA |
927 | child_lp = add_lwp (inferior_ptid); |
928 | child_lp->stopped = 1; | |
25289eb2 | 929 | child_lp->last_resume_kind = resume_stop; |
6c95b8df PA |
930 | |
931 | /* If this is a vfork child, then the address-space is shared | |
932 | with the parent. If we detached from the parent, then we can | |
933 | reuse the parent's program/address spaces. */ | |
934 | if (has_vforked || detach_fork) | |
935 | { | |
936 | child_inf->pspace = parent_pspace; | |
937 | child_inf->aspace = child_inf->pspace->aspace; | |
938 | } | |
939 | else | |
940 | { | |
941 | child_inf->aspace = new_address_space (); | |
942 | child_inf->pspace = add_program_space (child_inf->aspace); | |
943 | child_inf->removable = 1; | |
7dcd53a0 | 944 | child_inf->symfile_flags = SYMFILE_NO_READ; |
6c95b8df PA |
945 | set_current_program_space (child_inf->pspace); |
946 | clone_program_space (child_inf->pspace, parent_pspace); | |
947 | ||
948 | /* Let the shared library layer (solib-svr4) learn about | |
949 | this new process, relocate the cloned exec, pull in | |
950 | shared libraries, and install the solib event breakpoint. | |
951 | If a "cloned-VM" event was propagated better throughout | |
952 | the core, this wouldn't be required. */ | |
268a4a75 | 953 | solib_create_inferior_hook (0); |
6c95b8df | 954 | } |
ac264b3b | 955 | |
6c95b8df | 956 | /* Let the thread_db layer learn about this new process. */ |
ef29ce1a | 957 | check_for_thread_db (); |
4de4c07c DJ |
958 | } |
959 | ||
7feb7d06 | 960 | restore_child_signals_mask (&prev_mask); |
4de4c07c DJ |
961 | return 0; |
962 | } | |
963 | ||
4de4c07c | 964 | \f |
77b06cd7 | 965 | static int |
6d8fd2b7 | 966 | linux_child_insert_fork_catchpoint (int pid) |
4de4c07c | 967 | { |
77b06cd7 | 968 | return !linux_supports_tracefork (pid); |
3993f6b1 DJ |
969 | } |
970 | ||
eb73ad13 PA |
971 | static int |
972 | linux_child_remove_fork_catchpoint (int pid) | |
973 | { | |
974 | return 0; | |
975 | } | |
976 | ||
77b06cd7 | 977 | static int |
6d8fd2b7 | 978 | linux_child_insert_vfork_catchpoint (int pid) |
3993f6b1 | 979 | { |
77b06cd7 | 980 | return !linux_supports_tracefork (pid); |
3993f6b1 DJ |
981 | } |
982 | ||
eb73ad13 PA |
983 | static int |
984 | linux_child_remove_vfork_catchpoint (int pid) | |
985 | { | |
986 | return 0; | |
987 | } | |
988 | ||
77b06cd7 | 989 | static int |
6d8fd2b7 | 990 | linux_child_insert_exec_catchpoint (int pid) |
3993f6b1 | 991 | { |
77b06cd7 | 992 | return !linux_supports_tracefork (pid); |
3993f6b1 DJ |
993 | } |
994 | ||
eb73ad13 PA |
995 | static int |
996 | linux_child_remove_exec_catchpoint (int pid) | |
997 | { | |
998 | return 0; | |
999 | } | |
1000 | ||
a96d9b2e SDJ |
1001 | static int |
1002 | linux_child_set_syscall_catchpoint (int pid, int needed, int any_count, | |
1003 | int table_size, int *table) | |
1004 | { | |
77b06cd7 TJB |
1005 | if (!linux_supports_tracesysgood (pid)) |
1006 | return 1; | |
1007 | ||
a96d9b2e SDJ |
1008 | /* On GNU/Linux, we ignore the arguments. It means that we only |
1009 | enable the syscall catchpoints, but do not disable them. | |
77b06cd7 | 1010 | |
a96d9b2e SDJ |
1011 | Also, we do not use the `table' information because we do not |
1012 | filter system calls here. We let GDB do the logic for us. */ | |
1013 | return 0; | |
1014 | } | |
1015 | ||
d6b0e80f AC |
1016 | /* On GNU/Linux there are no real LWP's. The closest thing to LWP's |
1017 | are processes sharing the same VM space. A multi-threaded process | |
1018 | is basically a group of such processes. However, such a grouping | |
1019 | is almost entirely a user-space issue; the kernel doesn't enforce | |
1020 | such a grouping at all (this might change in the future). In | |
1021 | general, we'll rely on the threads library (i.e. the GNU/Linux | |
1022 | Threads library) to provide such a grouping. | |
1023 | ||
1024 | It is perfectly well possible to write a multi-threaded application | |
1025 | without the assistance of a threads library, by using the clone | |
1026 | system call directly. This module should be able to give some | |
1027 | rudimentary support for debugging such applications if developers | |
1028 | specify the CLONE_PTRACE flag in the clone system call, and are | |
1029 | using the Linux kernel 2.4 or above. | |
1030 | ||
1031 | Note that there are some peculiarities in GNU/Linux that affect | |
1032 | this code: | |
1033 | ||
1034 | - In general one should specify the __WCLONE flag to waitpid in | |
1035 | order to make it report events for any of the cloned processes | |
1036 | (and leave it out for the initial process). However, if a cloned | |
1037 | process has exited the exit status is only reported if the | |
1038 | __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but | |
1039 | we cannot use it since GDB must work on older systems too. | |
1040 | ||
1041 | - When a traced, cloned process exits and is waited for by the | |
1042 | debugger, the kernel reassigns it to the original parent and | |
1043 | keeps it around as a "zombie". Somehow, the GNU/Linux Threads | |
1044 | library doesn't notice this, which leads to the "zombie problem": | |
1045 | When debugged a multi-threaded process that spawns a lot of | |
1046 | threads will run out of processes, even if the threads exit, | |
1047 | because the "zombies" stay around. */ | |
1048 | ||
1049 | /* List of known LWPs. */ | |
9f0bdab8 | 1050 | struct lwp_info *lwp_list; |
d6b0e80f AC |
1051 | \f |
1052 | ||
d6b0e80f AC |
1053 | /* Original signal mask. */ |
1054 | static sigset_t normal_mask; | |
1055 | ||
1056 | /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in | |
1057 | _initialize_linux_nat. */ | |
1058 | static sigset_t suspend_mask; | |
1059 | ||
7feb7d06 PA |
1060 | /* Signals to block to make that sigsuspend work. */ |
1061 | static sigset_t blocked_mask; | |
1062 | ||
1063 | /* SIGCHLD action. */ | |
1064 | struct sigaction sigchld_action; | |
b84876c2 | 1065 | |
7feb7d06 PA |
1066 | /* Block child signals (SIGCHLD and linux threads signals), and store |
1067 | the previous mask in PREV_MASK. */ | |
84e46146 | 1068 | |
7feb7d06 PA |
1069 | static void |
1070 | block_child_signals (sigset_t *prev_mask) | |
1071 | { | |
1072 | /* Make sure SIGCHLD is blocked. */ | |
1073 | if (!sigismember (&blocked_mask, SIGCHLD)) | |
1074 | sigaddset (&blocked_mask, SIGCHLD); | |
1075 | ||
1076 | sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask); | |
1077 | } | |
1078 | ||
1079 | /* Restore child signals mask, previously returned by | |
1080 | block_child_signals. */ | |
1081 | ||
1082 | static void | |
1083 | restore_child_signals_mask (sigset_t *prev_mask) | |
1084 | { | |
1085 | sigprocmask (SIG_SETMASK, prev_mask, NULL); | |
1086 | } | |
2455069d UW |
1087 | |
1088 | /* Mask of signals to pass directly to the inferior. */ | |
1089 | static sigset_t pass_mask; | |
1090 | ||
1091 | /* Update signals to pass to the inferior. */ | |
1092 | static void | |
1093 | linux_nat_pass_signals (int numsigs, unsigned char *pass_signals) | |
1094 | { | |
1095 | int signo; | |
1096 | ||
1097 | sigemptyset (&pass_mask); | |
1098 | ||
1099 | for (signo = 1; signo < NSIG; signo++) | |
1100 | { | |
2ea28649 | 1101 | int target_signo = gdb_signal_from_host (signo); |
2455069d UW |
1102 | if (target_signo < numsigs && pass_signals[target_signo]) |
1103 | sigaddset (&pass_mask, signo); | |
1104 | } | |
1105 | } | |
1106 | ||
d6b0e80f AC |
1107 | \f |
1108 | ||
1109 | /* Prototypes for local functions. */ | |
1110 | static int stop_wait_callback (struct lwp_info *lp, void *data); | |
28439f5e | 1111 | static int linux_thread_alive (ptid_t ptid); |
6d8fd2b7 | 1112 | static char *linux_child_pid_to_exec_file (int pid); |
710151dd | 1113 | |
d6b0e80f AC |
1114 | \f |
1115 | /* Convert wait status STATUS to a string. Used for printing debug | |
1116 | messages only. */ | |
1117 | ||
1118 | static char * | |
1119 | status_to_str (int status) | |
1120 | { | |
1121 | static char buf[64]; | |
1122 | ||
1123 | if (WIFSTOPPED (status)) | |
206aa767 | 1124 | { |
ca2163eb | 1125 | if (WSTOPSIG (status) == SYSCALL_SIGTRAP) |
206aa767 DE |
1126 | snprintf (buf, sizeof (buf), "%s (stopped at syscall)", |
1127 | strsignal (SIGTRAP)); | |
1128 | else | |
1129 | snprintf (buf, sizeof (buf), "%s (stopped)", | |
1130 | strsignal (WSTOPSIG (status))); | |
1131 | } | |
d6b0e80f AC |
1132 | else if (WIFSIGNALED (status)) |
1133 | snprintf (buf, sizeof (buf), "%s (terminated)", | |
ba9b2ec3 | 1134 | strsignal (WTERMSIG (status))); |
d6b0e80f AC |
1135 | else |
1136 | snprintf (buf, sizeof (buf), "%d (exited)", WEXITSTATUS (status)); | |
1137 | ||
1138 | return buf; | |
1139 | } | |
1140 | ||
7b50312a PA |
1141 | /* Destroy and free LP. */ |
1142 | ||
1143 | static void | |
1144 | lwp_free (struct lwp_info *lp) | |
1145 | { | |
1146 | xfree (lp->arch_private); | |
1147 | xfree (lp); | |
1148 | } | |
1149 | ||
d90e17a7 PA |
1150 | /* Remove all LWPs belong to PID from the lwp list. */ |
1151 | ||
1152 | static void | |
1153 | purge_lwp_list (int pid) | |
1154 | { | |
1155 | struct lwp_info *lp, *lpprev, *lpnext; | |
1156 | ||
1157 | lpprev = NULL; | |
1158 | ||
1159 | for (lp = lwp_list; lp; lp = lpnext) | |
1160 | { | |
1161 | lpnext = lp->next; | |
1162 | ||
1163 | if (ptid_get_pid (lp->ptid) == pid) | |
1164 | { | |
1165 | if (lp == lwp_list) | |
1166 | lwp_list = lp->next; | |
1167 | else | |
1168 | lpprev->next = lp->next; | |
1169 | ||
7b50312a | 1170 | lwp_free (lp); |
d90e17a7 PA |
1171 | } |
1172 | else | |
1173 | lpprev = lp; | |
1174 | } | |
1175 | } | |
1176 | ||
26cb8b7c PA |
1177 | /* Add the LWP specified by PTID to the list. PTID is the first LWP |
1178 | in the process. Return a pointer to the structure describing the | |
1179 | new LWP. | |
1180 | ||
1181 | This differs from add_lwp in that we don't let the arch specific | |
1182 | bits know about this new thread. Current clients of this callback | |
1183 | take the opportunity to install watchpoints in the new thread, and | |
1184 | we shouldn't do that for the first thread. If we're spawning a | |
1185 | child ("run"), the thread executes the shell wrapper first, and we | |
1186 | shouldn't touch it until it execs the program we want to debug. | |
1187 | For "attach", it'd be okay to call the callback, but it's not | |
1188 | necessary, because watchpoints can't yet have been inserted into | |
1189 | the inferior. */ | |
d6b0e80f AC |
1190 | |
1191 | static struct lwp_info * | |
26cb8b7c | 1192 | add_initial_lwp (ptid_t ptid) |
d6b0e80f AC |
1193 | { |
1194 | struct lwp_info *lp; | |
1195 | ||
1196 | gdb_assert (is_lwp (ptid)); | |
1197 | ||
1198 | lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info)); | |
1199 | ||
1200 | memset (lp, 0, sizeof (struct lwp_info)); | |
1201 | ||
25289eb2 | 1202 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1203 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
1204 | ||
1205 | lp->ptid = ptid; | |
dc146f7c | 1206 | lp->core = -1; |
d6b0e80f AC |
1207 | |
1208 | lp->next = lwp_list; | |
1209 | lwp_list = lp; | |
d6b0e80f | 1210 | |
26cb8b7c PA |
1211 | return lp; |
1212 | } | |
1213 | ||
1214 | /* Add the LWP specified by PID to the list. Return a pointer to the | |
1215 | structure describing the new LWP. The LWP should already be | |
1216 | stopped. */ | |
1217 | ||
1218 | static struct lwp_info * | |
1219 | add_lwp (ptid_t ptid) | |
1220 | { | |
1221 | struct lwp_info *lp; | |
1222 | ||
1223 | lp = add_initial_lwp (ptid); | |
1224 | ||
6e012a6c PA |
1225 | /* Let the arch specific bits know about this new thread. Current |
1226 | clients of this callback take the opportunity to install | |
26cb8b7c PA |
1227 | watchpoints in the new thread. We don't do this for the first |
1228 | thread though. See add_initial_lwp. */ | |
1229 | if (linux_nat_new_thread != NULL) | |
7b50312a | 1230 | linux_nat_new_thread (lp); |
9f0bdab8 | 1231 | |
d6b0e80f AC |
1232 | return lp; |
1233 | } | |
1234 | ||
1235 | /* Remove the LWP specified by PID from the list. */ | |
1236 | ||
1237 | static void | |
1238 | delete_lwp (ptid_t ptid) | |
1239 | { | |
1240 | struct lwp_info *lp, *lpprev; | |
1241 | ||
1242 | lpprev = NULL; | |
1243 | ||
1244 | for (lp = lwp_list; lp; lpprev = lp, lp = lp->next) | |
1245 | if (ptid_equal (lp->ptid, ptid)) | |
1246 | break; | |
1247 | ||
1248 | if (!lp) | |
1249 | return; | |
1250 | ||
d6b0e80f AC |
1251 | if (lpprev) |
1252 | lpprev->next = lp->next; | |
1253 | else | |
1254 | lwp_list = lp->next; | |
1255 | ||
7b50312a | 1256 | lwp_free (lp); |
d6b0e80f AC |
1257 | } |
1258 | ||
1259 | /* Return a pointer to the structure describing the LWP corresponding | |
1260 | to PID. If no corresponding LWP could be found, return NULL. */ | |
1261 | ||
1262 | static struct lwp_info * | |
1263 | find_lwp_pid (ptid_t ptid) | |
1264 | { | |
1265 | struct lwp_info *lp; | |
1266 | int lwp; | |
1267 | ||
1268 | if (is_lwp (ptid)) | |
1269 | lwp = GET_LWP (ptid); | |
1270 | else | |
1271 | lwp = GET_PID (ptid); | |
1272 | ||
1273 | for (lp = lwp_list; lp; lp = lp->next) | |
1274 | if (lwp == GET_LWP (lp->ptid)) | |
1275 | return lp; | |
1276 | ||
1277 | return NULL; | |
1278 | } | |
1279 | ||
1280 | /* Call CALLBACK with its second argument set to DATA for every LWP in | |
1281 | the list. If CALLBACK returns 1 for a particular LWP, return a | |
1282 | pointer to the structure describing that LWP immediately. | |
1283 | Otherwise return NULL. */ | |
1284 | ||
1285 | struct lwp_info * | |
d90e17a7 PA |
1286 | iterate_over_lwps (ptid_t filter, |
1287 | int (*callback) (struct lwp_info *, void *), | |
1288 | void *data) | |
d6b0e80f AC |
1289 | { |
1290 | struct lwp_info *lp, *lpnext; | |
1291 | ||
1292 | for (lp = lwp_list; lp; lp = lpnext) | |
1293 | { | |
1294 | lpnext = lp->next; | |
d90e17a7 PA |
1295 | |
1296 | if (ptid_match (lp->ptid, filter)) | |
1297 | { | |
1298 | if ((*callback) (lp, data)) | |
1299 | return lp; | |
1300 | } | |
d6b0e80f AC |
1301 | } |
1302 | ||
1303 | return NULL; | |
1304 | } | |
1305 | ||
2277426b PA |
1306 | /* Update our internal state when changing from one checkpoint to |
1307 | another indicated by NEW_PTID. We can only switch single-threaded | |
1308 | applications, so we only create one new LWP, and the previous list | |
1309 | is discarded. */ | |
f973ed9c DJ |
1310 | |
1311 | void | |
1312 | linux_nat_switch_fork (ptid_t new_ptid) | |
1313 | { | |
1314 | struct lwp_info *lp; | |
1315 | ||
2277426b PA |
1316 | purge_lwp_list (GET_PID (inferior_ptid)); |
1317 | ||
f973ed9c DJ |
1318 | lp = add_lwp (new_ptid); |
1319 | lp->stopped = 1; | |
e26af52f | 1320 | |
2277426b PA |
1321 | /* This changes the thread's ptid while preserving the gdb thread |
1322 | num. Also changes the inferior pid, while preserving the | |
1323 | inferior num. */ | |
1324 | thread_change_ptid (inferior_ptid, new_ptid); | |
1325 | ||
1326 | /* We've just told GDB core that the thread changed target id, but, | |
1327 | in fact, it really is a different thread, with different register | |
1328 | contents. */ | |
1329 | registers_changed (); | |
e26af52f DJ |
1330 | } |
1331 | ||
e26af52f DJ |
1332 | /* Handle the exit of a single thread LP. */ |
1333 | ||
1334 | static void | |
1335 | exit_lwp (struct lwp_info *lp) | |
1336 | { | |
e09875d4 | 1337 | struct thread_info *th = find_thread_ptid (lp->ptid); |
063bfe2e VP |
1338 | |
1339 | if (th) | |
e26af52f | 1340 | { |
17faa917 DJ |
1341 | if (print_thread_events) |
1342 | printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid)); | |
1343 | ||
4f8d22e3 | 1344 | delete_thread (lp->ptid); |
e26af52f DJ |
1345 | } |
1346 | ||
1347 | delete_lwp (lp->ptid); | |
1348 | } | |
1349 | ||
a0ef4274 DJ |
1350 | /* Wait for the LWP specified by LP, which we have just attached to. |
1351 | Returns a wait status for that LWP, to cache. */ | |
1352 | ||
1353 | static int | |
1354 | linux_nat_post_attach_wait (ptid_t ptid, int first, int *cloned, | |
1355 | int *signalled) | |
1356 | { | |
1357 | pid_t new_pid, pid = GET_LWP (ptid); | |
1358 | int status; | |
1359 | ||
644cebc9 | 1360 | if (linux_proc_pid_is_stopped (pid)) |
a0ef4274 DJ |
1361 | { |
1362 | if (debug_linux_nat) | |
1363 | fprintf_unfiltered (gdb_stdlog, | |
1364 | "LNPAW: Attaching to a stopped process\n"); | |
1365 | ||
1366 | /* The process is definitely stopped. It is in a job control | |
1367 | stop, unless the kernel predates the TASK_STOPPED / | |
1368 | TASK_TRACED distinction, in which case it might be in a | |
1369 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
1370 | can kill it, signal it, et cetera. | |
1371 | ||
1372 | First make sure there is a pending SIGSTOP. Since we are | |
1373 | already attached, the process can not transition from stopped | |
1374 | to running without a PTRACE_CONT; so we know this signal will | |
1375 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
1376 | probably already in the queue (unless this kernel is old | |
1377 | enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP | |
1378 | is not an RT signal, it can only be queued once. */ | |
1379 | kill_lwp (pid, SIGSTOP); | |
1380 | ||
1381 | /* Finally, resume the stopped process. This will deliver the SIGSTOP | |
1382 | (or a higher priority signal, just like normal PTRACE_ATTACH). */ | |
1383 | ptrace (PTRACE_CONT, pid, 0, 0); | |
1384 | } | |
1385 | ||
1386 | /* Make sure the initial process is stopped. The user-level threads | |
1387 | layer might want to poke around in the inferior, and that won't | |
1388 | work if things haven't stabilized yet. */ | |
1389 | new_pid = my_waitpid (pid, &status, 0); | |
1390 | if (new_pid == -1 && errno == ECHILD) | |
1391 | { | |
1392 | if (first) | |
1393 | warning (_("%s is a cloned process"), target_pid_to_str (ptid)); | |
1394 | ||
1395 | /* Try again with __WCLONE to check cloned processes. */ | |
1396 | new_pid = my_waitpid (pid, &status, __WCLONE); | |
1397 | *cloned = 1; | |
1398 | } | |
1399 | ||
dacc9cb2 PP |
1400 | gdb_assert (pid == new_pid); |
1401 | ||
1402 | if (!WIFSTOPPED (status)) | |
1403 | { | |
1404 | /* The pid we tried to attach has apparently just exited. */ | |
1405 | if (debug_linux_nat) | |
1406 | fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s", | |
1407 | pid, status_to_str (status)); | |
1408 | return status; | |
1409 | } | |
a0ef4274 DJ |
1410 | |
1411 | if (WSTOPSIG (status) != SIGSTOP) | |
1412 | { | |
1413 | *signalled = 1; | |
1414 | if (debug_linux_nat) | |
1415 | fprintf_unfiltered (gdb_stdlog, | |
1416 | "LNPAW: Received %s after attaching\n", | |
1417 | status_to_str (status)); | |
1418 | } | |
1419 | ||
1420 | return status; | |
1421 | } | |
1422 | ||
84636d28 PA |
1423 | /* Attach to the LWP specified by PID. Return 0 if successful, -1 if |
1424 | the new LWP could not be attached, or 1 if we're already auto | |
1425 | attached to this thread, but haven't processed the | |
1426 | PTRACE_EVENT_CLONE event of its parent thread, so we just ignore | |
1427 | its existance, without considering it an error. */ | |
d6b0e80f | 1428 | |
9ee57c33 | 1429 | int |
93815fbf | 1430 | lin_lwp_attach_lwp (ptid_t ptid) |
d6b0e80f | 1431 | { |
9ee57c33 | 1432 | struct lwp_info *lp; |
7feb7d06 | 1433 | sigset_t prev_mask; |
84636d28 | 1434 | int lwpid; |
d6b0e80f AC |
1435 | |
1436 | gdb_assert (is_lwp (ptid)); | |
1437 | ||
7feb7d06 | 1438 | block_child_signals (&prev_mask); |
d6b0e80f | 1439 | |
9ee57c33 | 1440 | lp = find_lwp_pid (ptid); |
84636d28 | 1441 | lwpid = GET_LWP (ptid); |
d6b0e80f AC |
1442 | |
1443 | /* We assume that we're already attached to any LWP that has an id | |
1444 | equal to the overall process id, and to any LWP that is already | |
1445 | in our list of LWPs. If we're not seeing exit events from threads | |
1446 | and we've had PID wraparound since we last tried to stop all threads, | |
1447 | this assumption might be wrong; fortunately, this is very unlikely | |
1448 | to happen. */ | |
84636d28 | 1449 | if (lwpid != GET_PID (ptid) && lp == NULL) |
d6b0e80f | 1450 | { |
a0ef4274 | 1451 | int status, cloned = 0, signalled = 0; |
d6b0e80f | 1452 | |
84636d28 | 1453 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) |
9ee57c33 | 1454 | { |
84636d28 PA |
1455 | if (linux_supports_tracefork_flag) |
1456 | { | |
1457 | /* If we haven't stopped all threads when we get here, | |
1458 | we may have seen a thread listed in thread_db's list, | |
1459 | but not processed the PTRACE_EVENT_CLONE yet. If | |
1460 | that's the case, ignore this new thread, and let | |
1461 | normal event handling discover it later. */ | |
1462 | if (in_pid_list_p (stopped_pids, lwpid)) | |
1463 | { | |
1464 | /* We've already seen this thread stop, but we | |
1465 | haven't seen the PTRACE_EVENT_CLONE extended | |
1466 | event yet. */ | |
1467 | restore_child_signals_mask (&prev_mask); | |
1468 | return 0; | |
1469 | } | |
1470 | else | |
1471 | { | |
1472 | int new_pid; | |
1473 | int status; | |
1474 | ||
1475 | /* See if we've got a stop for this new child | |
1476 | pending. If so, we're already attached. */ | |
1477 | new_pid = my_waitpid (lwpid, &status, WNOHANG); | |
1478 | if (new_pid == -1 && errno == ECHILD) | |
1479 | new_pid = my_waitpid (lwpid, &status, __WCLONE | WNOHANG); | |
1480 | if (new_pid != -1) | |
1481 | { | |
1482 | if (WIFSTOPPED (status)) | |
1483 | add_to_pid_list (&stopped_pids, lwpid, status); | |
1484 | ||
1485 | restore_child_signals_mask (&prev_mask); | |
1486 | return 1; | |
1487 | } | |
1488 | } | |
1489 | } | |
1490 | ||
9ee57c33 DJ |
1491 | /* If we fail to attach to the thread, issue a warning, |
1492 | but continue. One way this can happen is if thread | |
e9efe249 | 1493 | creation is interrupted; as of Linux kernel 2.6.19, a |
9ee57c33 DJ |
1494 | bug may place threads in the thread list and then fail |
1495 | to create them. */ | |
1496 | warning (_("Can't attach %s: %s"), target_pid_to_str (ptid), | |
1497 | safe_strerror (errno)); | |
7feb7d06 | 1498 | restore_child_signals_mask (&prev_mask); |
9ee57c33 DJ |
1499 | return -1; |
1500 | } | |
1501 | ||
d6b0e80f AC |
1502 | if (debug_linux_nat) |
1503 | fprintf_unfiltered (gdb_stdlog, | |
1504 | "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n", | |
1505 | target_pid_to_str (ptid)); | |
1506 | ||
a0ef4274 | 1507 | status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled); |
dacc9cb2 | 1508 | if (!WIFSTOPPED (status)) |
673c2bbe DE |
1509 | { |
1510 | restore_child_signals_mask (&prev_mask); | |
f687d035 | 1511 | return 1; |
673c2bbe | 1512 | } |
dacc9cb2 | 1513 | |
a0ef4274 DJ |
1514 | lp = add_lwp (ptid); |
1515 | lp->stopped = 1; | |
1516 | lp->cloned = cloned; | |
1517 | lp->signalled = signalled; | |
1518 | if (WSTOPSIG (status) != SIGSTOP) | |
d6b0e80f | 1519 | { |
a0ef4274 DJ |
1520 | lp->resumed = 1; |
1521 | lp->status = status; | |
d6b0e80f AC |
1522 | } |
1523 | ||
a0ef4274 | 1524 | target_post_attach (GET_LWP (lp->ptid)); |
d6b0e80f AC |
1525 | |
1526 | if (debug_linux_nat) | |
1527 | { | |
1528 | fprintf_unfiltered (gdb_stdlog, | |
1529 | "LLAL: waitpid %s received %s\n", | |
1530 | target_pid_to_str (ptid), | |
1531 | status_to_str (status)); | |
1532 | } | |
1533 | } | |
1534 | else | |
1535 | { | |
1536 | /* We assume that the LWP representing the original process is | |
1537 | already stopped. Mark it as stopped in the data structure | |
155bd5d1 AC |
1538 | that the GNU/linux ptrace layer uses to keep track of |
1539 | threads. Note that this won't have already been done since | |
1540 | the main thread will have, we assume, been stopped by an | |
1541 | attach from a different layer. */ | |
9ee57c33 DJ |
1542 | if (lp == NULL) |
1543 | lp = add_lwp (ptid); | |
d6b0e80f AC |
1544 | lp->stopped = 1; |
1545 | } | |
9ee57c33 | 1546 | |
25289eb2 | 1547 | lp->last_resume_kind = resume_stop; |
7feb7d06 | 1548 | restore_child_signals_mask (&prev_mask); |
9ee57c33 | 1549 | return 0; |
d6b0e80f AC |
1550 | } |
1551 | ||
b84876c2 | 1552 | static void |
136d6dae VP |
1553 | linux_nat_create_inferior (struct target_ops *ops, |
1554 | char *exec_file, char *allargs, char **env, | |
b84876c2 PA |
1555 | int from_tty) |
1556 | { | |
10568435 JK |
1557 | #ifdef HAVE_PERSONALITY |
1558 | int personality_orig = 0, personality_set = 0; | |
1559 | #endif /* HAVE_PERSONALITY */ | |
b84876c2 PA |
1560 | |
1561 | /* The fork_child mechanism is synchronous and calls target_wait, so | |
1562 | we have to mask the async mode. */ | |
1563 | ||
10568435 JK |
1564 | #ifdef HAVE_PERSONALITY |
1565 | if (disable_randomization) | |
1566 | { | |
1567 | errno = 0; | |
1568 | personality_orig = personality (0xffffffff); | |
1569 | if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE)) | |
1570 | { | |
1571 | personality_set = 1; | |
1572 | personality (personality_orig | ADDR_NO_RANDOMIZE); | |
1573 | } | |
1574 | if (errno != 0 || (personality_set | |
1575 | && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE))) | |
1576 | warning (_("Error disabling address space randomization: %s"), | |
1577 | safe_strerror (errno)); | |
1578 | } | |
1579 | #endif /* HAVE_PERSONALITY */ | |
1580 | ||
2455069d UW |
1581 | /* Make sure we report all signals during startup. */ |
1582 | linux_nat_pass_signals (0, NULL); | |
1583 | ||
136d6dae | 1584 | linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty); |
b84876c2 | 1585 | |
10568435 JK |
1586 | #ifdef HAVE_PERSONALITY |
1587 | if (personality_set) | |
1588 | { | |
1589 | errno = 0; | |
1590 | personality (personality_orig); | |
1591 | if (errno != 0) | |
1592 | warning (_("Error restoring address space randomization: %s"), | |
1593 | safe_strerror (errno)); | |
1594 | } | |
1595 | #endif /* HAVE_PERSONALITY */ | |
b84876c2 PA |
1596 | } |
1597 | ||
d6b0e80f | 1598 | static void |
136d6dae | 1599 | linux_nat_attach (struct target_ops *ops, char *args, int from_tty) |
d6b0e80f AC |
1600 | { |
1601 | struct lwp_info *lp; | |
d6b0e80f | 1602 | int status; |
af990527 | 1603 | ptid_t ptid; |
87b0bb13 | 1604 | volatile struct gdb_exception ex; |
d6b0e80f | 1605 | |
2455069d UW |
1606 | /* Make sure we report all signals during attach. */ |
1607 | linux_nat_pass_signals (0, NULL); | |
1608 | ||
87b0bb13 JK |
1609 | TRY_CATCH (ex, RETURN_MASK_ERROR) |
1610 | { | |
1611 | linux_ops->to_attach (ops, args, from_tty); | |
1612 | } | |
1613 | if (ex.reason < 0) | |
1614 | { | |
1615 | pid_t pid = parse_pid_to_attach (args); | |
1616 | struct buffer buffer; | |
1617 | char *message, *buffer_s; | |
1618 | ||
1619 | message = xstrdup (ex.message); | |
1620 | make_cleanup (xfree, message); | |
1621 | ||
1622 | buffer_init (&buffer); | |
1623 | linux_ptrace_attach_warnings (pid, &buffer); | |
1624 | ||
1625 | buffer_grow_str0 (&buffer, ""); | |
1626 | buffer_s = buffer_finish (&buffer); | |
1627 | make_cleanup (xfree, buffer_s); | |
1628 | ||
1629 | throw_error (ex.error, "%s%s", buffer_s, message); | |
1630 | } | |
d6b0e80f | 1631 | |
af990527 PA |
1632 | /* The ptrace base target adds the main thread with (pid,0,0) |
1633 | format. Decorate it with lwp info. */ | |
1634 | ptid = BUILD_LWP (GET_PID (inferior_ptid), GET_PID (inferior_ptid)); | |
1635 | thread_change_ptid (inferior_ptid, ptid); | |
1636 | ||
9f0bdab8 | 1637 | /* Add the initial process as the first LWP to the list. */ |
26cb8b7c | 1638 | lp = add_initial_lwp (ptid); |
a0ef4274 DJ |
1639 | |
1640 | status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->cloned, | |
1641 | &lp->signalled); | |
dacc9cb2 PP |
1642 | if (!WIFSTOPPED (status)) |
1643 | { | |
1644 | if (WIFEXITED (status)) | |
1645 | { | |
1646 | int exit_code = WEXITSTATUS (status); | |
1647 | ||
1648 | target_terminal_ours (); | |
1649 | target_mourn_inferior (); | |
1650 | if (exit_code == 0) | |
1651 | error (_("Unable to attach: program exited normally.")); | |
1652 | else | |
1653 | error (_("Unable to attach: program exited with code %d."), | |
1654 | exit_code); | |
1655 | } | |
1656 | else if (WIFSIGNALED (status)) | |
1657 | { | |
2ea28649 | 1658 | enum gdb_signal signo; |
dacc9cb2 PP |
1659 | |
1660 | target_terminal_ours (); | |
1661 | target_mourn_inferior (); | |
1662 | ||
2ea28649 | 1663 | signo = gdb_signal_from_host (WTERMSIG (status)); |
dacc9cb2 PP |
1664 | error (_("Unable to attach: program terminated with signal " |
1665 | "%s, %s."), | |
2ea28649 PA |
1666 | gdb_signal_to_name (signo), |
1667 | gdb_signal_to_string (signo)); | |
dacc9cb2 PP |
1668 | } |
1669 | ||
1670 | internal_error (__FILE__, __LINE__, | |
1671 | _("unexpected status %d for PID %ld"), | |
1672 | status, (long) GET_LWP (ptid)); | |
1673 | } | |
1674 | ||
a0ef4274 | 1675 | lp->stopped = 1; |
9f0bdab8 | 1676 | |
a0ef4274 | 1677 | /* Save the wait status to report later. */ |
d6b0e80f | 1678 | lp->resumed = 1; |
a0ef4274 DJ |
1679 | if (debug_linux_nat) |
1680 | fprintf_unfiltered (gdb_stdlog, | |
1681 | "LNA: waitpid %ld, saving status %s\n", | |
1682 | (long) GET_PID (lp->ptid), status_to_str (status)); | |
710151dd | 1683 | |
7feb7d06 PA |
1684 | lp->status = status; |
1685 | ||
1686 | if (target_can_async_p ()) | |
1687 | target_async (inferior_event_handler, 0); | |
d6b0e80f AC |
1688 | } |
1689 | ||
a0ef4274 DJ |
1690 | /* Get pending status of LP. */ |
1691 | static int | |
1692 | get_pending_status (struct lwp_info *lp, int *status) | |
1693 | { | |
a493e3e2 | 1694 | enum gdb_signal signo = GDB_SIGNAL_0; |
ca2163eb PA |
1695 | |
1696 | /* If we paused threads momentarily, we may have stored pending | |
1697 | events in lp->status or lp->waitstatus (see stop_wait_callback), | |
1698 | and GDB core hasn't seen any signal for those threads. | |
1699 | Otherwise, the last signal reported to the core is found in the | |
1700 | thread object's stop_signal. | |
1701 | ||
1702 | There's a corner case that isn't handled here at present. Only | |
1703 | if the thread stopped with a TARGET_WAITKIND_STOPPED does | |
1704 | stop_signal make sense as a real signal to pass to the inferior. | |
1705 | Some catchpoint related events, like | |
1706 | TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set | |
a493e3e2 | 1707 | to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But, |
ca2163eb PA |
1708 | those traps are debug API (ptrace in our case) related and |
1709 | induced; the inferior wouldn't see them if it wasn't being | |
1710 | traced. Hence, we should never pass them to the inferior, even | |
1711 | when set to pass state. Since this corner case isn't handled by | |
1712 | infrun.c when proceeding with a signal, for consistency, neither | |
1713 | do we handle it here (or elsewhere in the file we check for | |
1714 | signal pass state). Normally SIGTRAP isn't set to pass state, so | |
1715 | this is really a corner case. */ | |
1716 | ||
1717 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
a493e3e2 | 1718 | signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */ |
ca2163eb | 1719 | else if (lp->status) |
2ea28649 | 1720 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
ca2163eb PA |
1721 | else if (non_stop && !is_executing (lp->ptid)) |
1722 | { | |
1723 | struct thread_info *tp = find_thread_ptid (lp->ptid); | |
e0881a8e | 1724 | |
16c381f0 | 1725 | signo = tp->suspend.stop_signal; |
ca2163eb PA |
1726 | } |
1727 | else if (!non_stop) | |
a0ef4274 | 1728 | { |
ca2163eb PA |
1729 | struct target_waitstatus last; |
1730 | ptid_t last_ptid; | |
4c28f408 | 1731 | |
ca2163eb | 1732 | get_last_target_status (&last_ptid, &last); |
4c28f408 | 1733 | |
ca2163eb PA |
1734 | if (GET_LWP (lp->ptid) == GET_LWP (last_ptid)) |
1735 | { | |
e09875d4 | 1736 | struct thread_info *tp = find_thread_ptid (lp->ptid); |
e0881a8e | 1737 | |
16c381f0 | 1738 | signo = tp->suspend.stop_signal; |
4c28f408 | 1739 | } |
ca2163eb | 1740 | } |
4c28f408 | 1741 | |
ca2163eb | 1742 | *status = 0; |
4c28f408 | 1743 | |
a493e3e2 | 1744 | if (signo == GDB_SIGNAL_0) |
ca2163eb PA |
1745 | { |
1746 | if (debug_linux_nat) | |
1747 | fprintf_unfiltered (gdb_stdlog, | |
1748 | "GPT: lwp %s has no pending signal\n", | |
1749 | target_pid_to_str (lp->ptid)); | |
1750 | } | |
1751 | else if (!signal_pass_state (signo)) | |
1752 | { | |
1753 | if (debug_linux_nat) | |
3e43a32a MS |
1754 | fprintf_unfiltered (gdb_stdlog, |
1755 | "GPT: lwp %s had signal %s, " | |
1756 | "but it is in no pass state\n", | |
ca2163eb | 1757 | target_pid_to_str (lp->ptid), |
2ea28649 | 1758 | gdb_signal_to_string (signo)); |
a0ef4274 | 1759 | } |
a0ef4274 | 1760 | else |
4c28f408 | 1761 | { |
2ea28649 | 1762 | *status = W_STOPCODE (gdb_signal_to_host (signo)); |
ca2163eb PA |
1763 | |
1764 | if (debug_linux_nat) | |
1765 | fprintf_unfiltered (gdb_stdlog, | |
1766 | "GPT: lwp %s has pending signal %s\n", | |
1767 | target_pid_to_str (lp->ptid), | |
2ea28649 | 1768 | gdb_signal_to_string (signo)); |
4c28f408 | 1769 | } |
a0ef4274 DJ |
1770 | |
1771 | return 0; | |
1772 | } | |
1773 | ||
d6b0e80f AC |
1774 | static int |
1775 | detach_callback (struct lwp_info *lp, void *data) | |
1776 | { | |
1777 | gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status)); | |
1778 | ||
1779 | if (debug_linux_nat && lp->status) | |
1780 | fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n", | |
1781 | strsignal (WSTOPSIG (lp->status)), | |
1782 | target_pid_to_str (lp->ptid)); | |
1783 | ||
a0ef4274 DJ |
1784 | /* If there is a pending SIGSTOP, get rid of it. */ |
1785 | if (lp->signalled) | |
d6b0e80f | 1786 | { |
d6b0e80f AC |
1787 | if (debug_linux_nat) |
1788 | fprintf_unfiltered (gdb_stdlog, | |
a0ef4274 DJ |
1789 | "DC: Sending SIGCONT to %s\n", |
1790 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 1791 | |
a0ef4274 | 1792 | kill_lwp (GET_LWP (lp->ptid), SIGCONT); |
d6b0e80f | 1793 | lp->signalled = 0; |
d6b0e80f AC |
1794 | } |
1795 | ||
1796 | /* We don't actually detach from the LWP that has an id equal to the | |
1797 | overall process id just yet. */ | |
1798 | if (GET_LWP (lp->ptid) != GET_PID (lp->ptid)) | |
1799 | { | |
a0ef4274 DJ |
1800 | int status = 0; |
1801 | ||
1802 | /* Pass on any pending signal for this LWP. */ | |
1803 | get_pending_status (lp, &status); | |
1804 | ||
7b50312a PA |
1805 | if (linux_nat_prepare_to_resume != NULL) |
1806 | linux_nat_prepare_to_resume (lp); | |
d6b0e80f AC |
1807 | errno = 0; |
1808 | if (ptrace (PTRACE_DETACH, GET_LWP (lp->ptid), 0, | |
a0ef4274 | 1809 | WSTOPSIG (status)) < 0) |
8a3fe4f8 | 1810 | error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid), |
d6b0e80f AC |
1811 | safe_strerror (errno)); |
1812 | ||
1813 | if (debug_linux_nat) | |
1814 | fprintf_unfiltered (gdb_stdlog, | |
1815 | "PTRACE_DETACH (%s, %s, 0) (OK)\n", | |
1816 | target_pid_to_str (lp->ptid), | |
7feb7d06 | 1817 | strsignal (WSTOPSIG (status))); |
d6b0e80f AC |
1818 | |
1819 | delete_lwp (lp->ptid); | |
1820 | } | |
1821 | ||
1822 | return 0; | |
1823 | } | |
1824 | ||
1825 | static void | |
136d6dae | 1826 | linux_nat_detach (struct target_ops *ops, char *args, int from_tty) |
d6b0e80f | 1827 | { |
b84876c2 | 1828 | int pid; |
a0ef4274 | 1829 | int status; |
d90e17a7 PA |
1830 | struct lwp_info *main_lwp; |
1831 | ||
1832 | pid = GET_PID (inferior_ptid); | |
a0ef4274 | 1833 | |
ae5e0686 MK |
1834 | /* Don't unregister from the event loop, as there may be other |
1835 | inferiors running. */ | |
b84876c2 | 1836 | |
4c28f408 PA |
1837 | /* Stop all threads before detaching. ptrace requires that the |
1838 | thread is stopped to sucessfully detach. */ | |
d90e17a7 | 1839 | iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL); |
4c28f408 PA |
1840 | /* ... and wait until all of them have reported back that |
1841 | they're no longer running. */ | |
d90e17a7 | 1842 | iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL); |
4c28f408 | 1843 | |
d90e17a7 | 1844 | iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL); |
d6b0e80f AC |
1845 | |
1846 | /* Only the initial process should be left right now. */ | |
d90e17a7 PA |
1847 | gdb_assert (num_lwps (GET_PID (inferior_ptid)) == 1); |
1848 | ||
1849 | main_lwp = find_lwp_pid (pid_to_ptid (pid)); | |
d6b0e80f | 1850 | |
a0ef4274 DJ |
1851 | /* Pass on any pending signal for the last LWP. */ |
1852 | if ((args == NULL || *args == '\0') | |
d90e17a7 | 1853 | && get_pending_status (main_lwp, &status) != -1 |
a0ef4274 DJ |
1854 | && WIFSTOPPED (status)) |
1855 | { | |
1856 | /* Put the signal number in ARGS so that inf_ptrace_detach will | |
1857 | pass it along with PTRACE_DETACH. */ | |
1858 | args = alloca (8); | |
1859 | sprintf (args, "%d", (int) WSTOPSIG (status)); | |
ddabfc73 TT |
1860 | if (debug_linux_nat) |
1861 | fprintf_unfiltered (gdb_stdlog, | |
1862 | "LND: Sending signal %s to %s\n", | |
1863 | args, | |
1864 | target_pid_to_str (main_lwp->ptid)); | |
a0ef4274 DJ |
1865 | } |
1866 | ||
7b50312a PA |
1867 | if (linux_nat_prepare_to_resume != NULL) |
1868 | linux_nat_prepare_to_resume (main_lwp); | |
d90e17a7 | 1869 | delete_lwp (main_lwp->ptid); |
b84876c2 | 1870 | |
7a7d3353 PA |
1871 | if (forks_exist_p ()) |
1872 | { | |
1873 | /* Multi-fork case. The current inferior_ptid is being detached | |
1874 | from, but there are other viable forks to debug. Detach from | |
1875 | the current fork, and context-switch to the first | |
1876 | available. */ | |
1877 | linux_fork_detach (args, from_tty); | |
7a7d3353 PA |
1878 | } |
1879 | else | |
1880 | linux_ops->to_detach (ops, args, from_tty); | |
d6b0e80f AC |
1881 | } |
1882 | ||
1883 | /* Resume LP. */ | |
1884 | ||
25289eb2 | 1885 | static void |
e5ef252a | 1886 | resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) |
d6b0e80f | 1887 | { |
25289eb2 | 1888 | if (lp->stopped) |
6c95b8df | 1889 | { |
25289eb2 PA |
1890 | struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid)); |
1891 | ||
1892 | if (inf->vfork_child != NULL) | |
1893 | { | |
1894 | if (debug_linux_nat) | |
1895 | fprintf_unfiltered (gdb_stdlog, | |
1896 | "RC: Not resuming %s (vfork parent)\n", | |
1897 | target_pid_to_str (lp->ptid)); | |
1898 | } | |
1899 | else if (lp->status == 0 | |
1900 | && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) | |
1901 | { | |
1902 | if (debug_linux_nat) | |
1903 | fprintf_unfiltered (gdb_stdlog, | |
e5ef252a PA |
1904 | "RC: Resuming sibling %s, %s, %s\n", |
1905 | target_pid_to_str (lp->ptid), | |
1906 | (signo != GDB_SIGNAL_0 | |
1907 | ? strsignal (gdb_signal_to_host (signo)) | |
1908 | : "0"), | |
1909 | step ? "step" : "resume"); | |
25289eb2 | 1910 | |
7b50312a PA |
1911 | if (linux_nat_prepare_to_resume != NULL) |
1912 | linux_nat_prepare_to_resume (lp); | |
25289eb2 PA |
1913 | linux_ops->to_resume (linux_ops, |
1914 | pid_to_ptid (GET_LWP (lp->ptid)), | |
e5ef252a | 1915 | step, signo); |
25289eb2 PA |
1916 | lp->stopped = 0; |
1917 | lp->step = step; | |
25289eb2 PA |
1918 | lp->stopped_by_watchpoint = 0; |
1919 | } | |
1920 | else | |
1921 | { | |
1922 | if (debug_linux_nat) | |
1923 | fprintf_unfiltered (gdb_stdlog, | |
1924 | "RC: Not resuming sibling %s (has pending)\n", | |
1925 | target_pid_to_str (lp->ptid)); | |
1926 | } | |
6c95b8df | 1927 | } |
25289eb2 | 1928 | else |
d6b0e80f | 1929 | { |
d90e17a7 PA |
1930 | if (debug_linux_nat) |
1931 | fprintf_unfiltered (gdb_stdlog, | |
25289eb2 | 1932 | "RC: Not resuming sibling %s (not stopped)\n", |
d6b0e80f | 1933 | target_pid_to_str (lp->ptid)); |
d6b0e80f | 1934 | } |
25289eb2 | 1935 | } |
d6b0e80f | 1936 | |
e5ef252a PA |
1937 | /* Resume LWP, with the last stop signal, if it is in pass state. */ |
1938 | ||
25289eb2 | 1939 | static int |
e5ef252a | 1940 | linux_nat_resume_callback (struct lwp_info *lp, void *data) |
25289eb2 | 1941 | { |
e5ef252a PA |
1942 | enum gdb_signal signo = GDB_SIGNAL_0; |
1943 | ||
1944 | if (lp->stopped) | |
1945 | { | |
1946 | struct thread_info *thread; | |
1947 | ||
1948 | thread = find_thread_ptid (lp->ptid); | |
1949 | if (thread != NULL) | |
1950 | { | |
1951 | if (signal_pass_state (thread->suspend.stop_signal)) | |
1952 | signo = thread->suspend.stop_signal; | |
1953 | thread->suspend.stop_signal = GDB_SIGNAL_0; | |
1954 | } | |
1955 | } | |
1956 | ||
1957 | resume_lwp (lp, 0, signo); | |
d6b0e80f AC |
1958 | return 0; |
1959 | } | |
1960 | ||
1961 | static int | |
1962 | resume_clear_callback (struct lwp_info *lp, void *data) | |
1963 | { | |
1964 | lp->resumed = 0; | |
25289eb2 | 1965 | lp->last_resume_kind = resume_stop; |
d6b0e80f AC |
1966 | return 0; |
1967 | } | |
1968 | ||
1969 | static int | |
1970 | resume_set_callback (struct lwp_info *lp, void *data) | |
1971 | { | |
1972 | lp->resumed = 1; | |
25289eb2 | 1973 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1974 | return 0; |
1975 | } | |
1976 | ||
1977 | static void | |
28439f5e | 1978 | linux_nat_resume (struct target_ops *ops, |
2ea28649 | 1979 | ptid_t ptid, int step, enum gdb_signal signo) |
d6b0e80f | 1980 | { |
7feb7d06 | 1981 | sigset_t prev_mask; |
d6b0e80f | 1982 | struct lwp_info *lp; |
d90e17a7 | 1983 | int resume_many; |
d6b0e80f | 1984 | |
76f50ad1 DJ |
1985 | if (debug_linux_nat) |
1986 | fprintf_unfiltered (gdb_stdlog, | |
1987 | "LLR: Preparing to %s %s, %s, inferior_ptid %s\n", | |
1988 | step ? "step" : "resume", | |
1989 | target_pid_to_str (ptid), | |
a493e3e2 | 1990 | (signo != GDB_SIGNAL_0 |
2ea28649 | 1991 | ? strsignal (gdb_signal_to_host (signo)) : "0"), |
76f50ad1 DJ |
1992 | target_pid_to_str (inferior_ptid)); |
1993 | ||
7feb7d06 | 1994 | block_child_signals (&prev_mask); |
b84876c2 | 1995 | |
d6b0e80f | 1996 | /* A specific PTID means `step only this process id'. */ |
d90e17a7 PA |
1997 | resume_many = (ptid_equal (minus_one_ptid, ptid) |
1998 | || ptid_is_pid (ptid)); | |
4c28f408 | 1999 | |
e3e9f5a2 PA |
2000 | /* Mark the lwps we're resuming as resumed. */ |
2001 | iterate_over_lwps (ptid, resume_set_callback, NULL); | |
d6b0e80f | 2002 | |
d90e17a7 PA |
2003 | /* See if it's the current inferior that should be handled |
2004 | specially. */ | |
2005 | if (resume_many) | |
2006 | lp = find_lwp_pid (inferior_ptid); | |
2007 | else | |
2008 | lp = find_lwp_pid (ptid); | |
9f0bdab8 | 2009 | gdb_assert (lp != NULL); |
d6b0e80f | 2010 | |
9f0bdab8 DJ |
2011 | /* Remember if we're stepping. */ |
2012 | lp->step = step; | |
25289eb2 | 2013 | lp->last_resume_kind = step ? resume_step : resume_continue; |
d6b0e80f | 2014 | |
9f0bdab8 DJ |
2015 | /* If we have a pending wait status for this thread, there is no |
2016 | point in resuming the process. But first make sure that | |
2017 | linux_nat_wait won't preemptively handle the event - we | |
2018 | should never take this short-circuit if we are going to | |
2019 | leave LP running, since we have skipped resuming all the | |
2020 | other threads. This bit of code needs to be synchronized | |
2021 | with linux_nat_wait. */ | |
76f50ad1 | 2022 | |
9f0bdab8 DJ |
2023 | if (lp->status && WIFSTOPPED (lp->status)) |
2024 | { | |
2455069d UW |
2025 | if (!lp->step |
2026 | && WSTOPSIG (lp->status) | |
2027 | && sigismember (&pass_mask, WSTOPSIG (lp->status))) | |
d6b0e80f | 2028 | { |
9f0bdab8 DJ |
2029 | if (debug_linux_nat) |
2030 | fprintf_unfiltered (gdb_stdlog, | |
2031 | "LLR: Not short circuiting for ignored " | |
2032 | "status 0x%x\n", lp->status); | |
2033 | ||
d6b0e80f AC |
2034 | /* FIXME: What should we do if we are supposed to continue |
2035 | this thread with a signal? */ | |
a493e3e2 | 2036 | gdb_assert (signo == GDB_SIGNAL_0); |
2ea28649 | 2037 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
9f0bdab8 DJ |
2038 | lp->status = 0; |
2039 | } | |
2040 | } | |
76f50ad1 | 2041 | |
6c95b8df | 2042 | if (lp->status || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) |
9f0bdab8 DJ |
2043 | { |
2044 | /* FIXME: What should we do if we are supposed to continue | |
2045 | this thread with a signal? */ | |
a493e3e2 | 2046 | gdb_assert (signo == GDB_SIGNAL_0); |
76f50ad1 | 2047 | |
9f0bdab8 DJ |
2048 | if (debug_linux_nat) |
2049 | fprintf_unfiltered (gdb_stdlog, | |
2050 | "LLR: Short circuiting for status 0x%x\n", | |
2051 | lp->status); | |
d6b0e80f | 2052 | |
7feb7d06 PA |
2053 | restore_child_signals_mask (&prev_mask); |
2054 | if (target_can_async_p ()) | |
2055 | { | |
2056 | target_async (inferior_event_handler, 0); | |
2057 | /* Tell the event loop we have something to process. */ | |
2058 | async_file_mark (); | |
2059 | } | |
9f0bdab8 | 2060 | return; |
d6b0e80f AC |
2061 | } |
2062 | ||
9f0bdab8 | 2063 | /* Mark LWP as not stopped to prevent it from being continued by |
e5ef252a | 2064 | linux_nat_resume_callback. */ |
9f0bdab8 DJ |
2065 | lp->stopped = 0; |
2066 | ||
d90e17a7 | 2067 | if (resume_many) |
e5ef252a | 2068 | iterate_over_lwps (ptid, linux_nat_resume_callback, NULL); |
d90e17a7 PA |
2069 | |
2070 | /* Convert to something the lower layer understands. */ | |
2071 | ptid = pid_to_ptid (GET_LWP (lp->ptid)); | |
d6b0e80f | 2072 | |
7b50312a PA |
2073 | if (linux_nat_prepare_to_resume != NULL) |
2074 | linux_nat_prepare_to_resume (lp); | |
28439f5e | 2075 | linux_ops->to_resume (linux_ops, ptid, step, signo); |
ebec9a0f | 2076 | lp->stopped_by_watchpoint = 0; |
9f0bdab8 | 2077 | |
d6b0e80f AC |
2078 | if (debug_linux_nat) |
2079 | fprintf_unfiltered (gdb_stdlog, | |
2080 | "LLR: %s %s, %s (resume event thread)\n", | |
2081 | step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
2082 | target_pid_to_str (ptid), | |
a493e3e2 | 2083 | (signo != GDB_SIGNAL_0 |
2ea28649 | 2084 | ? strsignal (gdb_signal_to_host (signo)) : "0")); |
b84876c2 | 2085 | |
7feb7d06 | 2086 | restore_child_signals_mask (&prev_mask); |
b84876c2 | 2087 | if (target_can_async_p ()) |
8ea051c5 | 2088 | target_async (inferior_event_handler, 0); |
d6b0e80f AC |
2089 | } |
2090 | ||
c5f62d5f | 2091 | /* Send a signal to an LWP. */ |
d6b0e80f AC |
2092 | |
2093 | static int | |
2094 | kill_lwp (int lwpid, int signo) | |
2095 | { | |
c5f62d5f DE |
2096 | /* Use tkill, if possible, in case we are using nptl threads. If tkill |
2097 | fails, then we are not using nptl threads and we should be using kill. */ | |
d6b0e80f AC |
2098 | |
2099 | #ifdef HAVE_TKILL_SYSCALL | |
c5f62d5f DE |
2100 | { |
2101 | static int tkill_failed; | |
2102 | ||
2103 | if (!tkill_failed) | |
2104 | { | |
2105 | int ret; | |
2106 | ||
2107 | errno = 0; | |
2108 | ret = syscall (__NR_tkill, lwpid, signo); | |
2109 | if (errno != ENOSYS) | |
2110 | return ret; | |
2111 | tkill_failed = 1; | |
2112 | } | |
2113 | } | |
d6b0e80f AC |
2114 | #endif |
2115 | ||
2116 | return kill (lwpid, signo); | |
2117 | } | |
2118 | ||
ca2163eb PA |
2119 | /* Handle a GNU/Linux syscall trap wait response. If we see a syscall |
2120 | event, check if the core is interested in it: if not, ignore the | |
2121 | event, and keep waiting; otherwise, we need to toggle the LWP's | |
2122 | syscall entry/exit status, since the ptrace event itself doesn't | |
2123 | indicate it, and report the trap to higher layers. */ | |
2124 | ||
2125 | static int | |
2126 | linux_handle_syscall_trap (struct lwp_info *lp, int stopping) | |
2127 | { | |
2128 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
2129 | struct gdbarch *gdbarch = target_thread_architecture (lp->ptid); | |
2130 | int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid); | |
2131 | ||
2132 | if (stopping) | |
2133 | { | |
2134 | /* If we're stopping threads, there's a SIGSTOP pending, which | |
2135 | makes it so that the LWP reports an immediate syscall return, | |
2136 | followed by the SIGSTOP. Skip seeing that "return" using | |
2137 | PTRACE_CONT directly, and let stop_wait_callback collect the | |
2138 | SIGSTOP. Later when the thread is resumed, a new syscall | |
2139 | entry event. If we didn't do this (and returned 0), we'd | |
2140 | leave a syscall entry pending, and our caller, by using | |
2141 | PTRACE_CONT to collect the SIGSTOP, skips the syscall return | |
2142 | itself. Later, when the user re-resumes this LWP, we'd see | |
2143 | another syscall entry event and we'd mistake it for a return. | |
2144 | ||
2145 | If stop_wait_callback didn't force the SIGSTOP out of the LWP | |
2146 | (leaving immediately with LWP->signalled set, without issuing | |
2147 | a PTRACE_CONT), it would still be problematic to leave this | |
2148 | syscall enter pending, as later when the thread is resumed, | |
2149 | it would then see the same syscall exit mentioned above, | |
2150 | followed by the delayed SIGSTOP, while the syscall didn't | |
2151 | actually get to execute. It seems it would be even more | |
2152 | confusing to the user. */ | |
2153 | ||
2154 | if (debug_linux_nat) | |
2155 | fprintf_unfiltered (gdb_stdlog, | |
2156 | "LHST: ignoring syscall %d " | |
2157 | "for LWP %ld (stopping threads), " | |
2158 | "resuming with PTRACE_CONT for SIGSTOP\n", | |
2159 | syscall_number, | |
2160 | GET_LWP (lp->ptid)); | |
2161 | ||
2162 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2163 | ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); | |
2164 | return 1; | |
2165 | } | |
2166 | ||
2167 | if (catch_syscall_enabled ()) | |
2168 | { | |
2169 | /* Always update the entry/return state, even if this particular | |
2170 | syscall isn't interesting to the core now. In async mode, | |
2171 | the user could install a new catchpoint for this syscall | |
2172 | between syscall enter/return, and we'll need to know to | |
2173 | report a syscall return if that happens. */ | |
2174 | lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
2175 | ? TARGET_WAITKIND_SYSCALL_RETURN | |
2176 | : TARGET_WAITKIND_SYSCALL_ENTRY); | |
2177 | ||
2178 | if (catching_syscall_number (syscall_number)) | |
2179 | { | |
2180 | /* Alright, an event to report. */ | |
2181 | ourstatus->kind = lp->syscall_state; | |
2182 | ourstatus->value.syscall_number = syscall_number; | |
2183 | ||
2184 | if (debug_linux_nat) | |
2185 | fprintf_unfiltered (gdb_stdlog, | |
2186 | "LHST: stopping for %s of syscall %d" | |
2187 | " for LWP %ld\n", | |
3e43a32a MS |
2188 | lp->syscall_state |
2189 | == TARGET_WAITKIND_SYSCALL_ENTRY | |
ca2163eb PA |
2190 | ? "entry" : "return", |
2191 | syscall_number, | |
2192 | GET_LWP (lp->ptid)); | |
2193 | return 0; | |
2194 | } | |
2195 | ||
2196 | if (debug_linux_nat) | |
2197 | fprintf_unfiltered (gdb_stdlog, | |
2198 | "LHST: ignoring %s of syscall %d " | |
2199 | "for LWP %ld\n", | |
2200 | lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
2201 | ? "entry" : "return", | |
2202 | syscall_number, | |
2203 | GET_LWP (lp->ptid)); | |
2204 | } | |
2205 | else | |
2206 | { | |
2207 | /* If we had been syscall tracing, and hence used PT_SYSCALL | |
2208 | before on this LWP, it could happen that the user removes all | |
2209 | syscall catchpoints before we get to process this event. | |
2210 | There are two noteworthy issues here: | |
2211 | ||
2212 | - When stopped at a syscall entry event, resuming with | |
2213 | PT_STEP still resumes executing the syscall and reports a | |
2214 | syscall return. | |
2215 | ||
2216 | - Only PT_SYSCALL catches syscall enters. If we last | |
2217 | single-stepped this thread, then this event can't be a | |
2218 | syscall enter. If we last single-stepped this thread, this | |
2219 | has to be a syscall exit. | |
2220 | ||
2221 | The points above mean that the next resume, be it PT_STEP or | |
2222 | PT_CONTINUE, can not trigger a syscall trace event. */ | |
2223 | if (debug_linux_nat) | |
2224 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
2225 | "LHST: caught syscall event " |
2226 | "with no syscall catchpoints." | |
ca2163eb PA |
2227 | " %d for LWP %ld, ignoring\n", |
2228 | syscall_number, | |
2229 | GET_LWP (lp->ptid)); | |
2230 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2231 | } | |
2232 | ||
2233 | /* The core isn't interested in this event. For efficiency, avoid | |
2234 | stopping all threads only to have the core resume them all again. | |
2235 | Since we're not stopping threads, if we're still syscall tracing | |
2236 | and not stepping, we can't use PTRACE_CONT here, as we'd miss any | |
2237 | subsequent syscall. Simply resume using the inf-ptrace layer, | |
2238 | which knows when to use PT_SYSCALL or PT_CONTINUE. */ | |
2239 | ||
2240 | /* Note that gdbarch_get_syscall_number may access registers, hence | |
2241 | fill a regcache. */ | |
2242 | registers_changed (); | |
7b50312a PA |
2243 | if (linux_nat_prepare_to_resume != NULL) |
2244 | linux_nat_prepare_to_resume (lp); | |
ca2163eb | 2245 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
a493e3e2 | 2246 | lp->step, GDB_SIGNAL_0); |
ca2163eb PA |
2247 | return 1; |
2248 | } | |
2249 | ||
3d799a95 DJ |
2250 | /* Handle a GNU/Linux extended wait response. If we see a clone |
2251 | event, we need to add the new LWP to our list (and not report the | |
2252 | trap to higher layers). This function returns non-zero if the | |
2253 | event should be ignored and we should wait again. If STOPPING is | |
2254 | true, the new LWP remains stopped, otherwise it is continued. */ | |
d6b0e80f AC |
2255 | |
2256 | static int | |
3d799a95 DJ |
2257 | linux_handle_extended_wait (struct lwp_info *lp, int status, |
2258 | int stopping) | |
d6b0e80f | 2259 | { |
3d799a95 DJ |
2260 | int pid = GET_LWP (lp->ptid); |
2261 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
3d799a95 | 2262 | int event = status >> 16; |
d6b0e80f | 2263 | |
3d799a95 DJ |
2264 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
2265 | || event == PTRACE_EVENT_CLONE) | |
d6b0e80f | 2266 | { |
3d799a95 DJ |
2267 | unsigned long new_pid; |
2268 | int ret; | |
2269 | ||
2270 | ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); | |
6fc19103 | 2271 | |
3d799a95 DJ |
2272 | /* If we haven't already seen the new PID stop, wait for it now. */ |
2273 | if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
2274 | { | |
2275 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
2276 | hits the SIGSTOP, but we're already attached. */ | |
2277 | ret = my_waitpid (new_pid, &status, | |
2278 | (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0); | |
2279 | if (ret == -1) | |
2280 | perror_with_name (_("waiting for new child")); | |
2281 | else if (ret != new_pid) | |
2282 | internal_error (__FILE__, __LINE__, | |
2283 | _("wait returned unexpected PID %d"), ret); | |
2284 | else if (!WIFSTOPPED (status)) | |
2285 | internal_error (__FILE__, __LINE__, | |
2286 | _("wait returned unexpected status 0x%x"), status); | |
2287 | } | |
2288 | ||
3a3e9ee3 | 2289 | ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0); |
3d799a95 | 2290 | |
26cb8b7c PA |
2291 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) |
2292 | { | |
2293 | /* The arch-specific native code may need to know about new | |
2294 | forks even if those end up never mapped to an | |
2295 | inferior. */ | |
2296 | if (linux_nat_new_fork != NULL) | |
2297 | linux_nat_new_fork (lp, new_pid); | |
2298 | } | |
2299 | ||
2277426b PA |
2300 | if (event == PTRACE_EVENT_FORK |
2301 | && linux_fork_checkpointing_p (GET_PID (lp->ptid))) | |
2302 | { | |
2277426b PA |
2303 | /* Handle checkpointing by linux-fork.c here as a special |
2304 | case. We don't want the follow-fork-mode or 'catch fork' | |
2305 | to interfere with this. */ | |
2306 | ||
2307 | /* This won't actually modify the breakpoint list, but will | |
2308 | physically remove the breakpoints from the child. */ | |
d80ee84f | 2309 | detach_breakpoints (ptid_build (new_pid, new_pid, 0)); |
2277426b PA |
2310 | |
2311 | /* Retain child fork in ptrace (stopped) state. */ | |
14571dad MS |
2312 | if (!find_fork_pid (new_pid)) |
2313 | add_fork (new_pid); | |
2277426b PA |
2314 | |
2315 | /* Report as spurious, so that infrun doesn't want to follow | |
2316 | this fork. We're actually doing an infcall in | |
2317 | linux-fork.c. */ | |
2318 | ourstatus->kind = TARGET_WAITKIND_SPURIOUS; | |
2319 | linux_enable_event_reporting (pid_to_ptid (new_pid)); | |
2320 | ||
2321 | /* Report the stop to the core. */ | |
2322 | return 0; | |
2323 | } | |
2324 | ||
3d799a95 DJ |
2325 | if (event == PTRACE_EVENT_FORK) |
2326 | ourstatus->kind = TARGET_WAITKIND_FORKED; | |
2327 | else if (event == PTRACE_EVENT_VFORK) | |
2328 | ourstatus->kind = TARGET_WAITKIND_VFORKED; | |
6fc19103 | 2329 | else |
3d799a95 | 2330 | { |
78768c4a JK |
2331 | struct lwp_info *new_lp; |
2332 | ||
3d799a95 | 2333 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
78768c4a | 2334 | |
3c4d7e12 PA |
2335 | if (debug_linux_nat) |
2336 | fprintf_unfiltered (gdb_stdlog, | |
2337 | "LHEW: Got clone event " | |
2338 | "from LWP %d, new child is LWP %ld\n", | |
2339 | pid, new_pid); | |
2340 | ||
d90e17a7 | 2341 | new_lp = add_lwp (BUILD_LWP (new_pid, GET_PID (lp->ptid))); |
3d799a95 | 2342 | new_lp->cloned = 1; |
4c28f408 | 2343 | new_lp->stopped = 1; |
d6b0e80f | 2344 | |
3d799a95 DJ |
2345 | if (WSTOPSIG (status) != SIGSTOP) |
2346 | { | |
2347 | /* This can happen if someone starts sending signals to | |
2348 | the new thread before it gets a chance to run, which | |
2349 | have a lower number than SIGSTOP (e.g. SIGUSR1). | |
2350 | This is an unlikely case, and harder to handle for | |
2351 | fork / vfork than for clone, so we do not try - but | |
2352 | we handle it for clone events here. We'll send | |
2353 | the other signal on to the thread below. */ | |
2354 | ||
2355 | new_lp->signalled = 1; | |
2356 | } | |
2357 | else | |
79395f92 PA |
2358 | { |
2359 | struct thread_info *tp; | |
2360 | ||
2361 | /* When we stop for an event in some other thread, and | |
2362 | pull the thread list just as this thread has cloned, | |
2363 | we'll have seen the new thread in the thread_db list | |
2364 | before handling the CLONE event (glibc's | |
2365 | pthread_create adds the new thread to the thread list | |
2366 | before clone'ing, and has the kernel fill in the | |
2367 | thread's tid on the clone call with | |
2368 | CLONE_PARENT_SETTID). If that happened, and the core | |
2369 | had requested the new thread to stop, we'll have | |
2370 | killed it with SIGSTOP. But since SIGSTOP is not an | |
2371 | RT signal, it can only be queued once. We need to be | |
2372 | careful to not resume the LWP if we wanted it to | |
2373 | stop. In that case, we'll leave the SIGSTOP pending. | |
a493e3e2 | 2374 | It will later be reported as GDB_SIGNAL_0. */ |
79395f92 PA |
2375 | tp = find_thread_ptid (new_lp->ptid); |
2376 | if (tp != NULL && tp->stop_requested) | |
2377 | new_lp->last_resume_kind = resume_stop; | |
2378 | else | |
2379 | status = 0; | |
2380 | } | |
d6b0e80f | 2381 | |
4c28f408 | 2382 | if (non_stop) |
3d799a95 | 2383 | { |
4c28f408 PA |
2384 | /* Add the new thread to GDB's lists as soon as possible |
2385 | so that: | |
2386 | ||
2387 | 1) the frontend doesn't have to wait for a stop to | |
2388 | display them, and, | |
2389 | ||
2390 | 2) we tag it with the correct running state. */ | |
2391 | ||
2392 | /* If the thread_db layer is active, let it know about | |
2393 | this new thread, and add it to GDB's list. */ | |
2394 | if (!thread_db_attach_lwp (new_lp->ptid)) | |
2395 | { | |
2396 | /* We're not using thread_db. Add it to GDB's | |
2397 | list. */ | |
2398 | target_post_attach (GET_LWP (new_lp->ptid)); | |
2399 | add_thread (new_lp->ptid); | |
2400 | } | |
2401 | ||
2402 | if (!stopping) | |
2403 | { | |
2404 | set_running (new_lp->ptid, 1); | |
2405 | set_executing (new_lp->ptid, 1); | |
e21ffe51 PA |
2406 | /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced |
2407 | resume_stop. */ | |
2408 | new_lp->last_resume_kind = resume_continue; | |
4c28f408 PA |
2409 | } |
2410 | } | |
2411 | ||
79395f92 PA |
2412 | if (status != 0) |
2413 | { | |
2414 | /* We created NEW_LP so it cannot yet contain STATUS. */ | |
2415 | gdb_assert (new_lp->status == 0); | |
2416 | ||
2417 | /* Save the wait status to report later. */ | |
2418 | if (debug_linux_nat) | |
2419 | fprintf_unfiltered (gdb_stdlog, | |
2420 | "LHEW: waitpid of new LWP %ld, " | |
2421 | "saving status %s\n", | |
2422 | (long) GET_LWP (new_lp->ptid), | |
2423 | status_to_str (status)); | |
2424 | new_lp->status = status; | |
2425 | } | |
2426 | ||
ca2163eb PA |
2427 | /* Note the need to use the low target ops to resume, to |
2428 | handle resuming with PT_SYSCALL if we have syscall | |
2429 | catchpoints. */ | |
4c28f408 PA |
2430 | if (!stopping) |
2431 | { | |
3d799a95 | 2432 | new_lp->resumed = 1; |
ca2163eb | 2433 | |
79395f92 | 2434 | if (status == 0) |
ad34eb2f | 2435 | { |
e21ffe51 | 2436 | gdb_assert (new_lp->last_resume_kind == resume_continue); |
ad34eb2f JK |
2437 | if (debug_linux_nat) |
2438 | fprintf_unfiltered (gdb_stdlog, | |
79395f92 PA |
2439 | "LHEW: resuming new LWP %ld\n", |
2440 | GET_LWP (new_lp->ptid)); | |
7b50312a PA |
2441 | if (linux_nat_prepare_to_resume != NULL) |
2442 | linux_nat_prepare_to_resume (new_lp); | |
79395f92 | 2443 | linux_ops->to_resume (linux_ops, pid_to_ptid (new_pid), |
a493e3e2 | 2444 | 0, GDB_SIGNAL_0); |
79395f92 | 2445 | new_lp->stopped = 0; |
ad34eb2f JK |
2446 | } |
2447 | } | |
d6b0e80f | 2448 | |
3d799a95 DJ |
2449 | if (debug_linux_nat) |
2450 | fprintf_unfiltered (gdb_stdlog, | |
3c4d7e12 | 2451 | "LHEW: resuming parent LWP %d\n", pid); |
7b50312a PA |
2452 | if (linux_nat_prepare_to_resume != NULL) |
2453 | linux_nat_prepare_to_resume (lp); | |
ca2163eb | 2454 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
a493e3e2 | 2455 | 0, GDB_SIGNAL_0); |
3d799a95 DJ |
2456 | |
2457 | return 1; | |
2458 | } | |
2459 | ||
2460 | return 0; | |
d6b0e80f AC |
2461 | } |
2462 | ||
3d799a95 DJ |
2463 | if (event == PTRACE_EVENT_EXEC) |
2464 | { | |
a75724bc PA |
2465 | if (debug_linux_nat) |
2466 | fprintf_unfiltered (gdb_stdlog, | |
2467 | "LHEW: Got exec event from LWP %ld\n", | |
2468 | GET_LWP (lp->ptid)); | |
2469 | ||
3d799a95 DJ |
2470 | ourstatus->kind = TARGET_WAITKIND_EXECD; |
2471 | ourstatus->value.execd_pathname | |
6d8fd2b7 | 2472 | = xstrdup (linux_child_pid_to_exec_file (pid)); |
3d799a95 | 2473 | |
6c95b8df PA |
2474 | return 0; |
2475 | } | |
2476 | ||
2477 | if (event == PTRACE_EVENT_VFORK_DONE) | |
2478 | { | |
2479 | if (current_inferior ()->waiting_for_vfork_done) | |
3d799a95 | 2480 | { |
6c95b8df | 2481 | if (debug_linux_nat) |
3e43a32a MS |
2482 | fprintf_unfiltered (gdb_stdlog, |
2483 | "LHEW: Got expected PTRACE_EVENT_" | |
2484 | "VFORK_DONE from LWP %ld: stopping\n", | |
6c95b8df | 2485 | GET_LWP (lp->ptid)); |
3d799a95 | 2486 | |
6c95b8df PA |
2487 | ourstatus->kind = TARGET_WAITKIND_VFORK_DONE; |
2488 | return 0; | |
3d799a95 DJ |
2489 | } |
2490 | ||
6c95b8df | 2491 | if (debug_linux_nat) |
3e43a32a MS |
2492 | fprintf_unfiltered (gdb_stdlog, |
2493 | "LHEW: Got PTRACE_EVENT_VFORK_DONE " | |
2494 | "from LWP %ld: resuming\n", | |
6c95b8df PA |
2495 | GET_LWP (lp->ptid)); |
2496 | ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); | |
2497 | return 1; | |
3d799a95 DJ |
2498 | } |
2499 | ||
2500 | internal_error (__FILE__, __LINE__, | |
2501 | _("unknown ptrace event %d"), event); | |
d6b0e80f AC |
2502 | } |
2503 | ||
2504 | /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has | |
2505 | exited. */ | |
2506 | ||
2507 | static int | |
2508 | wait_lwp (struct lwp_info *lp) | |
2509 | { | |
2510 | pid_t pid; | |
432b4d03 | 2511 | int status = 0; |
d6b0e80f | 2512 | int thread_dead = 0; |
432b4d03 | 2513 | sigset_t prev_mask; |
d6b0e80f AC |
2514 | |
2515 | gdb_assert (!lp->stopped); | |
2516 | gdb_assert (lp->status == 0); | |
2517 | ||
432b4d03 JK |
2518 | /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
2519 | block_child_signals (&prev_mask); | |
2520 | ||
2521 | for (;;) | |
d6b0e80f | 2522 | { |
432b4d03 JK |
2523 | /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind |
2524 | was right and we should just call sigsuspend. */ | |
2525 | ||
2526 | pid = my_waitpid (GET_LWP (lp->ptid), &status, WNOHANG); | |
d6b0e80f | 2527 | if (pid == -1 && errno == ECHILD) |
432b4d03 | 2528 | pid = my_waitpid (GET_LWP (lp->ptid), &status, __WCLONE | WNOHANG); |
a9f4bb21 PA |
2529 | if (pid == -1 && errno == ECHILD) |
2530 | { | |
2531 | /* The thread has previously exited. We need to delete it | |
2532 | now because, for some vendor 2.4 kernels with NPTL | |
2533 | support backported, there won't be an exit event unless | |
2534 | it is the main thread. 2.6 kernels will report an exit | |
2535 | event for each thread that exits, as expected. */ | |
2536 | thread_dead = 1; | |
2537 | if (debug_linux_nat) | |
2538 | fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n", | |
2539 | target_pid_to_str (lp->ptid)); | |
2540 | } | |
432b4d03 JK |
2541 | if (pid != 0) |
2542 | break; | |
2543 | ||
2544 | /* Bugs 10970, 12702. | |
2545 | Thread group leader may have exited in which case we'll lock up in | |
2546 | waitpid if there are other threads, even if they are all zombies too. | |
2547 | Basically, we're not supposed to use waitpid this way. | |
2548 | __WCLONE is not applicable for the leader so we can't use that. | |
2549 | LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED | |
2550 | process; it gets ESRCH both for the zombie and for running processes. | |
2551 | ||
2552 | As a workaround, check if we're waiting for the thread group leader and | |
2553 | if it's a zombie, and avoid calling waitpid if it is. | |
2554 | ||
2555 | This is racy, what if the tgl becomes a zombie right after we check? | |
2556 | Therefore always use WNOHANG with sigsuspend - it is equivalent to | |
5f572dec | 2557 | waiting waitpid but linux_proc_pid_is_zombie is safe this way. */ |
432b4d03 JK |
2558 | |
2559 | if (GET_PID (lp->ptid) == GET_LWP (lp->ptid) | |
5f572dec | 2560 | && linux_proc_pid_is_zombie (GET_LWP (lp->ptid))) |
d6b0e80f | 2561 | { |
d6b0e80f AC |
2562 | thread_dead = 1; |
2563 | if (debug_linux_nat) | |
432b4d03 JK |
2564 | fprintf_unfiltered (gdb_stdlog, |
2565 | "WL: Thread group leader %s vanished.\n", | |
d6b0e80f | 2566 | target_pid_to_str (lp->ptid)); |
432b4d03 | 2567 | break; |
d6b0e80f | 2568 | } |
432b4d03 JK |
2569 | |
2570 | /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers | |
2571 | get invoked despite our caller had them intentionally blocked by | |
2572 | block_child_signals. This is sensitive only to the loop of | |
2573 | linux_nat_wait_1 and there if we get called my_waitpid gets called | |
2574 | again before it gets to sigsuspend so we can safely let the handlers | |
2575 | get executed here. */ | |
2576 | ||
2577 | sigsuspend (&suspend_mask); | |
2578 | } | |
2579 | ||
2580 | restore_child_signals_mask (&prev_mask); | |
2581 | ||
d6b0e80f AC |
2582 | if (!thread_dead) |
2583 | { | |
2584 | gdb_assert (pid == GET_LWP (lp->ptid)); | |
2585 | ||
2586 | if (debug_linux_nat) | |
2587 | { | |
2588 | fprintf_unfiltered (gdb_stdlog, | |
2589 | "WL: waitpid %s received %s\n", | |
2590 | target_pid_to_str (lp->ptid), | |
2591 | status_to_str (status)); | |
2592 | } | |
d6b0e80f | 2593 | |
a9f4bb21 PA |
2594 | /* Check if the thread has exited. */ |
2595 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
2596 | { | |
2597 | thread_dead = 1; | |
2598 | if (debug_linux_nat) | |
2599 | fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n", | |
2600 | target_pid_to_str (lp->ptid)); | |
2601 | } | |
d6b0e80f AC |
2602 | } |
2603 | ||
2604 | if (thread_dead) | |
2605 | { | |
e26af52f | 2606 | exit_lwp (lp); |
d6b0e80f AC |
2607 | return 0; |
2608 | } | |
2609 | ||
2610 | gdb_assert (WIFSTOPPED (status)); | |
2611 | ||
ca2163eb PA |
2612 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2613 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2614 | { | |
2615 | /* No longer need the sysgood bit. The ptrace event ends up | |
2616 | recorded in lp->waitstatus if we care for it. We can carry | |
2617 | on handling the event like a regular SIGTRAP from here | |
2618 | on. */ | |
2619 | status = W_STOPCODE (SIGTRAP); | |
2620 | if (linux_handle_syscall_trap (lp, 1)) | |
2621 | return wait_lwp (lp); | |
2622 | } | |
2623 | ||
d6b0e80f AC |
2624 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
2625 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0) | |
2626 | { | |
2627 | if (debug_linux_nat) | |
2628 | fprintf_unfiltered (gdb_stdlog, | |
2629 | "WL: Handling extended status 0x%06x\n", | |
2630 | status); | |
3d799a95 | 2631 | if (linux_handle_extended_wait (lp, status, 1)) |
d6b0e80f AC |
2632 | return wait_lwp (lp); |
2633 | } | |
2634 | ||
2635 | return status; | |
2636 | } | |
2637 | ||
2638 | /* Send a SIGSTOP to LP. */ | |
2639 | ||
2640 | static int | |
2641 | stop_callback (struct lwp_info *lp, void *data) | |
2642 | { | |
2643 | if (!lp->stopped && !lp->signalled) | |
2644 | { | |
2645 | int ret; | |
2646 | ||
2647 | if (debug_linux_nat) | |
2648 | { | |
2649 | fprintf_unfiltered (gdb_stdlog, | |
2650 | "SC: kill %s **<SIGSTOP>**\n", | |
2651 | target_pid_to_str (lp->ptid)); | |
2652 | } | |
2653 | errno = 0; | |
2654 | ret = kill_lwp (GET_LWP (lp->ptid), SIGSTOP); | |
2655 | if (debug_linux_nat) | |
2656 | { | |
2657 | fprintf_unfiltered (gdb_stdlog, | |
2658 | "SC: lwp kill %d %s\n", | |
2659 | ret, | |
2660 | errno ? safe_strerror (errno) : "ERRNO-OK"); | |
2661 | } | |
2662 | ||
2663 | lp->signalled = 1; | |
2664 | gdb_assert (lp->status == 0); | |
2665 | } | |
2666 | ||
2667 | return 0; | |
2668 | } | |
2669 | ||
7b50312a PA |
2670 | /* Request a stop on LWP. */ |
2671 | ||
2672 | void | |
2673 | linux_stop_lwp (struct lwp_info *lwp) | |
2674 | { | |
2675 | stop_callback (lwp, NULL); | |
2676 | } | |
2677 | ||
57380f4e | 2678 | /* Return non-zero if LWP PID has a pending SIGINT. */ |
d6b0e80f AC |
2679 | |
2680 | static int | |
57380f4e DJ |
2681 | linux_nat_has_pending_sigint (int pid) |
2682 | { | |
2683 | sigset_t pending, blocked, ignored; | |
57380f4e DJ |
2684 | |
2685 | linux_proc_pending_signals (pid, &pending, &blocked, &ignored); | |
2686 | ||
2687 | if (sigismember (&pending, SIGINT) | |
2688 | && !sigismember (&ignored, SIGINT)) | |
2689 | return 1; | |
2690 | ||
2691 | return 0; | |
2692 | } | |
2693 | ||
2694 | /* Set a flag in LP indicating that we should ignore its next SIGINT. */ | |
2695 | ||
2696 | static int | |
2697 | set_ignore_sigint (struct lwp_info *lp, void *data) | |
d6b0e80f | 2698 | { |
57380f4e DJ |
2699 | /* If a thread has a pending SIGINT, consume it; otherwise, set a |
2700 | flag to consume the next one. */ | |
2701 | if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) | |
2702 | && WSTOPSIG (lp->status) == SIGINT) | |
2703 | lp->status = 0; | |
2704 | else | |
2705 | lp->ignore_sigint = 1; | |
2706 | ||
2707 | return 0; | |
2708 | } | |
2709 | ||
2710 | /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. | |
2711 | This function is called after we know the LWP has stopped; if the LWP | |
2712 | stopped before the expected SIGINT was delivered, then it will never have | |
2713 | arrived. Also, if the signal was delivered to a shared queue and consumed | |
2714 | by a different thread, it will never be delivered to this LWP. */ | |
d6b0e80f | 2715 | |
57380f4e DJ |
2716 | static void |
2717 | maybe_clear_ignore_sigint (struct lwp_info *lp) | |
2718 | { | |
2719 | if (!lp->ignore_sigint) | |
2720 | return; | |
2721 | ||
2722 | if (!linux_nat_has_pending_sigint (GET_LWP (lp->ptid))) | |
2723 | { | |
2724 | if (debug_linux_nat) | |
2725 | fprintf_unfiltered (gdb_stdlog, | |
2726 | "MCIS: Clearing bogus flag for %s\n", | |
2727 | target_pid_to_str (lp->ptid)); | |
2728 | lp->ignore_sigint = 0; | |
2729 | } | |
2730 | } | |
2731 | ||
ebec9a0f PA |
2732 | /* Fetch the possible triggered data watchpoint info and store it in |
2733 | LP. | |
2734 | ||
2735 | On some archs, like x86, that use debug registers to set | |
2736 | watchpoints, it's possible that the way to know which watched | |
2737 | address trapped, is to check the register that is used to select | |
2738 | which address to watch. Problem is, between setting the watchpoint | |
2739 | and reading back which data address trapped, the user may change | |
2740 | the set of watchpoints, and, as a consequence, GDB changes the | |
2741 | debug registers in the inferior. To avoid reading back a stale | |
2742 | stopped-data-address when that happens, we cache in LP the fact | |
2743 | that a watchpoint trapped, and the corresponding data address, as | |
2744 | soon as we see LP stop with a SIGTRAP. If GDB changes the debug | |
2745 | registers meanwhile, we have the cached data we can rely on. */ | |
2746 | ||
2747 | static void | |
2748 | save_sigtrap (struct lwp_info *lp) | |
2749 | { | |
2750 | struct cleanup *old_chain; | |
2751 | ||
2752 | if (linux_ops->to_stopped_by_watchpoint == NULL) | |
2753 | { | |
2754 | lp->stopped_by_watchpoint = 0; | |
2755 | return; | |
2756 | } | |
2757 | ||
2758 | old_chain = save_inferior_ptid (); | |
2759 | inferior_ptid = lp->ptid; | |
2760 | ||
2761 | lp->stopped_by_watchpoint = linux_ops->to_stopped_by_watchpoint (); | |
2762 | ||
2763 | if (lp->stopped_by_watchpoint) | |
2764 | { | |
2765 | if (linux_ops->to_stopped_data_address != NULL) | |
2766 | lp->stopped_data_address_p = | |
2767 | linux_ops->to_stopped_data_address (¤t_target, | |
2768 | &lp->stopped_data_address); | |
2769 | else | |
2770 | lp->stopped_data_address_p = 0; | |
2771 | } | |
2772 | ||
2773 | do_cleanups (old_chain); | |
2774 | } | |
2775 | ||
2776 | /* See save_sigtrap. */ | |
2777 | ||
2778 | static int | |
2779 | linux_nat_stopped_by_watchpoint (void) | |
2780 | { | |
2781 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2782 | ||
2783 | gdb_assert (lp != NULL); | |
2784 | ||
2785 | return lp->stopped_by_watchpoint; | |
2786 | } | |
2787 | ||
2788 | static int | |
2789 | linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p) | |
2790 | { | |
2791 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2792 | ||
2793 | gdb_assert (lp != NULL); | |
2794 | ||
2795 | *addr_p = lp->stopped_data_address; | |
2796 | ||
2797 | return lp->stopped_data_address_p; | |
2798 | } | |
2799 | ||
26ab7092 JK |
2800 | /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
2801 | ||
2802 | static int | |
2803 | sigtrap_is_event (int status) | |
2804 | { | |
2805 | return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; | |
2806 | } | |
2807 | ||
2808 | /* SIGTRAP-like events recognizer. */ | |
2809 | ||
2810 | static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event; | |
2811 | ||
00390b84 JK |
2812 | /* Check for SIGTRAP-like events in LP. */ |
2813 | ||
2814 | static int | |
2815 | linux_nat_lp_status_is_event (struct lwp_info *lp) | |
2816 | { | |
2817 | /* We check for lp->waitstatus in addition to lp->status, because we can | |
2818 | have pending process exits recorded in lp->status | |
2819 | and W_EXITCODE(0,0) == 0. We should probably have an additional | |
2820 | lp->status_p flag. */ | |
2821 | ||
2822 | return (lp->waitstatus.kind == TARGET_WAITKIND_IGNORE | |
2823 | && linux_nat_status_is_event (lp->status)); | |
2824 | } | |
2825 | ||
26ab7092 JK |
2826 | /* Set alternative SIGTRAP-like events recognizer. If |
2827 | breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be | |
2828 | applied. */ | |
2829 | ||
2830 | void | |
2831 | linux_nat_set_status_is_event (struct target_ops *t, | |
2832 | int (*status_is_event) (int status)) | |
2833 | { | |
2834 | linux_nat_status_is_event = status_is_event; | |
2835 | } | |
2836 | ||
57380f4e DJ |
2837 | /* Wait until LP is stopped. */ |
2838 | ||
2839 | static int | |
2840 | stop_wait_callback (struct lwp_info *lp, void *data) | |
2841 | { | |
6c95b8df PA |
2842 | struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid)); |
2843 | ||
2844 | /* If this is a vfork parent, bail out, it is not going to report | |
2845 | any SIGSTOP until the vfork is done with. */ | |
2846 | if (inf->vfork_child != NULL) | |
2847 | return 0; | |
2848 | ||
d6b0e80f AC |
2849 | if (!lp->stopped) |
2850 | { | |
2851 | int status; | |
2852 | ||
2853 | status = wait_lwp (lp); | |
2854 | if (status == 0) | |
2855 | return 0; | |
2856 | ||
57380f4e DJ |
2857 | if (lp->ignore_sigint && WIFSTOPPED (status) |
2858 | && WSTOPSIG (status) == SIGINT) | |
d6b0e80f | 2859 | { |
57380f4e | 2860 | lp->ignore_sigint = 0; |
d6b0e80f AC |
2861 | |
2862 | errno = 0; | |
2863 | ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); | |
2864 | if (debug_linux_nat) | |
2865 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
2866 | "PTRACE_CONT %s, 0, 0 (%s) " |
2867 | "(discarding SIGINT)\n", | |
d6b0e80f AC |
2868 | target_pid_to_str (lp->ptid), |
2869 | errno ? safe_strerror (errno) : "OK"); | |
2870 | ||
57380f4e | 2871 | return stop_wait_callback (lp, NULL); |
d6b0e80f AC |
2872 | } |
2873 | ||
57380f4e DJ |
2874 | maybe_clear_ignore_sigint (lp); |
2875 | ||
d6b0e80f AC |
2876 | if (WSTOPSIG (status) != SIGSTOP) |
2877 | { | |
e5ef252a | 2878 | /* The thread was stopped with a signal other than SIGSTOP. */ |
7feb7d06 | 2879 | |
e5ef252a PA |
2880 | save_sigtrap (lp); |
2881 | ||
2882 | if (debug_linux_nat) | |
2883 | fprintf_unfiltered (gdb_stdlog, | |
2884 | "SWC: Pending event %s in %s\n", | |
2885 | status_to_str ((int) status), | |
2886 | target_pid_to_str (lp->ptid)); | |
2887 | ||
2888 | /* Save the sigtrap event. */ | |
2889 | lp->status = status; | |
2890 | gdb_assert (!lp->stopped); | |
2891 | gdb_assert (lp->signalled); | |
2892 | lp->stopped = 1; | |
d6b0e80f AC |
2893 | } |
2894 | else | |
2895 | { | |
2896 | /* We caught the SIGSTOP that we intended to catch, so | |
2897 | there's no SIGSTOP pending. */ | |
e5ef252a PA |
2898 | |
2899 | if (debug_linux_nat) | |
2900 | fprintf_unfiltered (gdb_stdlog, | |
2901 | "SWC: Delayed SIGSTOP caught for %s.\n", | |
2902 | target_pid_to_str (lp->ptid)); | |
2903 | ||
d6b0e80f | 2904 | lp->stopped = 1; |
e5ef252a PA |
2905 | |
2906 | /* Reset SIGNALLED only after the stop_wait_callback call | |
2907 | above as it does gdb_assert on SIGNALLED. */ | |
d6b0e80f AC |
2908 | lp->signalled = 0; |
2909 | } | |
2910 | } | |
2911 | ||
2912 | return 0; | |
2913 | } | |
2914 | ||
d6b0e80f AC |
2915 | /* Return non-zero if LP has a wait status pending. */ |
2916 | ||
2917 | static int | |
2918 | status_callback (struct lwp_info *lp, void *data) | |
2919 | { | |
2920 | /* Only report a pending wait status if we pretend that this has | |
2921 | indeed been resumed. */ | |
ca2163eb PA |
2922 | if (!lp->resumed) |
2923 | return 0; | |
2924 | ||
2925 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
2926 | { | |
2927 | /* A ptrace event, like PTRACE_FORK|VFORK|EXEC, syscall event, | |
766062f6 | 2928 | or a pending process exit. Note that `W_EXITCODE(0,0) == |
ca2163eb PA |
2929 | 0', so a clean process exit can not be stored pending in |
2930 | lp->status, it is indistinguishable from | |
2931 | no-pending-status. */ | |
2932 | return 1; | |
2933 | } | |
2934 | ||
2935 | if (lp->status != 0) | |
2936 | return 1; | |
2937 | ||
2938 | return 0; | |
d6b0e80f AC |
2939 | } |
2940 | ||
2941 | /* Return non-zero if LP isn't stopped. */ | |
2942 | ||
2943 | static int | |
2944 | running_callback (struct lwp_info *lp, void *data) | |
2945 | { | |
25289eb2 PA |
2946 | return (!lp->stopped |
2947 | || ((lp->status != 0 | |
2948 | || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
2949 | && lp->resumed)); | |
d6b0e80f AC |
2950 | } |
2951 | ||
2952 | /* Count the LWP's that have had events. */ | |
2953 | ||
2954 | static int | |
2955 | count_events_callback (struct lwp_info *lp, void *data) | |
2956 | { | |
2957 | int *count = data; | |
2958 | ||
2959 | gdb_assert (count != NULL); | |
2960 | ||
e09490f1 | 2961 | /* Count only resumed LWPs that have a SIGTRAP event pending. */ |
00390b84 | 2962 | if (lp->resumed && linux_nat_lp_status_is_event (lp)) |
d6b0e80f AC |
2963 | (*count)++; |
2964 | ||
2965 | return 0; | |
2966 | } | |
2967 | ||
2968 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
2969 | ||
2970 | static int | |
2971 | select_singlestep_lwp_callback (struct lwp_info *lp, void *data) | |
2972 | { | |
25289eb2 PA |
2973 | if (lp->last_resume_kind == resume_step |
2974 | && lp->status != 0) | |
d6b0e80f AC |
2975 | return 1; |
2976 | else | |
2977 | return 0; | |
2978 | } | |
2979 | ||
2980 | /* Select the Nth LWP that has had a SIGTRAP event. */ | |
2981 | ||
2982 | static int | |
2983 | select_event_lwp_callback (struct lwp_info *lp, void *data) | |
2984 | { | |
2985 | int *selector = data; | |
2986 | ||
2987 | gdb_assert (selector != NULL); | |
2988 | ||
1777feb0 | 2989 | /* Select only resumed LWPs that have a SIGTRAP event pending. */ |
00390b84 | 2990 | if (lp->resumed && linux_nat_lp_status_is_event (lp)) |
d6b0e80f AC |
2991 | if ((*selector)-- == 0) |
2992 | return 1; | |
2993 | ||
2994 | return 0; | |
2995 | } | |
2996 | ||
710151dd PA |
2997 | static int |
2998 | cancel_breakpoint (struct lwp_info *lp) | |
2999 | { | |
3000 | /* Arrange for a breakpoint to be hit again later. We don't keep | |
3001 | the SIGTRAP status and don't forward the SIGTRAP signal to the | |
3002 | LWP. We will handle the current event, eventually we will resume | |
3003 | this LWP, and this breakpoint will trap again. | |
3004 | ||
3005 | If we do not do this, then we run the risk that the user will | |
3006 | delete or disable the breakpoint, but the LWP will have already | |
3007 | tripped on it. */ | |
3008 | ||
515630c5 UW |
3009 | struct regcache *regcache = get_thread_regcache (lp->ptid); |
3010 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
3011 | CORE_ADDR pc; | |
3012 | ||
3013 | pc = regcache_read_pc (regcache) - gdbarch_decr_pc_after_break (gdbarch); | |
6c95b8df | 3014 | if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
710151dd PA |
3015 | { |
3016 | if (debug_linux_nat) | |
3017 | fprintf_unfiltered (gdb_stdlog, | |
3018 | "CB: Push back breakpoint for %s\n", | |
3019 | target_pid_to_str (lp->ptid)); | |
3020 | ||
3021 | /* Back up the PC if necessary. */ | |
515630c5 UW |
3022 | if (gdbarch_decr_pc_after_break (gdbarch)) |
3023 | regcache_write_pc (regcache, pc); | |
3024 | ||
710151dd PA |
3025 | return 1; |
3026 | } | |
3027 | return 0; | |
3028 | } | |
3029 | ||
d6b0e80f AC |
3030 | static int |
3031 | cancel_breakpoints_callback (struct lwp_info *lp, void *data) | |
3032 | { | |
3033 | struct lwp_info *event_lp = data; | |
3034 | ||
3035 | /* Leave the LWP that has been elected to receive a SIGTRAP alone. */ | |
3036 | if (lp == event_lp) | |
3037 | return 0; | |
3038 | ||
3039 | /* If a LWP other than the LWP that we're reporting an event for has | |
3040 | hit a GDB breakpoint (as opposed to some random trap signal), | |
3041 | then just arrange for it to hit it again later. We don't keep | |
3042 | the SIGTRAP status and don't forward the SIGTRAP signal to the | |
3043 | LWP. We will handle the current event, eventually we will resume | |
3044 | all LWPs, and this one will get its breakpoint trap again. | |
3045 | ||
3046 | If we do not do this, then we run the risk that the user will | |
3047 | delete or disable the breakpoint, but the LWP will have already | |
3048 | tripped on it. */ | |
3049 | ||
00390b84 | 3050 | if (linux_nat_lp_status_is_event (lp) |
710151dd PA |
3051 | && cancel_breakpoint (lp)) |
3052 | /* Throw away the SIGTRAP. */ | |
3053 | lp->status = 0; | |
d6b0e80f AC |
3054 | |
3055 | return 0; | |
3056 | } | |
3057 | ||
3058 | /* Select one LWP out of those that have events pending. */ | |
3059 | ||
3060 | static void | |
d90e17a7 | 3061 | select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
d6b0e80f AC |
3062 | { |
3063 | int num_events = 0; | |
3064 | int random_selector; | |
3065 | struct lwp_info *event_lp; | |
3066 | ||
ac264b3b | 3067 | /* Record the wait status for the original LWP. */ |
d6b0e80f AC |
3068 | (*orig_lp)->status = *status; |
3069 | ||
3070 | /* Give preference to any LWP that is being single-stepped. */ | |
d90e17a7 PA |
3071 | event_lp = iterate_over_lwps (filter, |
3072 | select_singlestep_lwp_callback, NULL); | |
d6b0e80f AC |
3073 | if (event_lp != NULL) |
3074 | { | |
3075 | if (debug_linux_nat) | |
3076 | fprintf_unfiltered (gdb_stdlog, | |
3077 | "SEL: Select single-step %s\n", | |
3078 | target_pid_to_str (event_lp->ptid)); | |
3079 | } | |
3080 | else | |
3081 | { | |
3082 | /* No single-stepping LWP. Select one at random, out of those | |
3083 | which have had SIGTRAP events. */ | |
3084 | ||
3085 | /* First see how many SIGTRAP events we have. */ | |
d90e17a7 | 3086 | iterate_over_lwps (filter, count_events_callback, &num_events); |
d6b0e80f AC |
3087 | |
3088 | /* Now randomly pick a LWP out of those that have had a SIGTRAP. */ | |
3089 | random_selector = (int) | |
3090 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
3091 | ||
3092 | if (debug_linux_nat && num_events > 1) | |
3093 | fprintf_unfiltered (gdb_stdlog, | |
3094 | "SEL: Found %d SIGTRAP events, selecting #%d\n", | |
3095 | num_events, random_selector); | |
3096 | ||
d90e17a7 PA |
3097 | event_lp = iterate_over_lwps (filter, |
3098 | select_event_lwp_callback, | |
d6b0e80f AC |
3099 | &random_selector); |
3100 | } | |
3101 | ||
3102 | if (event_lp != NULL) | |
3103 | { | |
3104 | /* Switch the event LWP. */ | |
3105 | *orig_lp = event_lp; | |
3106 | *status = event_lp->status; | |
3107 | } | |
3108 | ||
3109 | /* Flush the wait status for the event LWP. */ | |
3110 | (*orig_lp)->status = 0; | |
3111 | } | |
3112 | ||
3113 | /* Return non-zero if LP has been resumed. */ | |
3114 | ||
3115 | static int | |
3116 | resumed_callback (struct lwp_info *lp, void *data) | |
3117 | { | |
3118 | return lp->resumed; | |
3119 | } | |
3120 | ||
12d9289a PA |
3121 | /* Stop an active thread, verify it still exists, then resume it. If |
3122 | the thread ends up with a pending status, then it is not resumed, | |
3123 | and *DATA (really a pointer to int), is set. */ | |
d6b0e80f AC |
3124 | |
3125 | static int | |
3126 | stop_and_resume_callback (struct lwp_info *lp, void *data) | |
3127 | { | |
12d9289a PA |
3128 | int *new_pending_p = data; |
3129 | ||
25289eb2 | 3130 | if (!lp->stopped) |
d6b0e80f | 3131 | { |
25289eb2 PA |
3132 | ptid_t ptid = lp->ptid; |
3133 | ||
d6b0e80f AC |
3134 | stop_callback (lp, NULL); |
3135 | stop_wait_callback (lp, NULL); | |
25289eb2 PA |
3136 | |
3137 | /* Resume if the lwp still exists, and the core wanted it | |
3138 | running. */ | |
12d9289a PA |
3139 | lp = find_lwp_pid (ptid); |
3140 | if (lp != NULL) | |
25289eb2 | 3141 | { |
12d9289a PA |
3142 | if (lp->last_resume_kind == resume_stop |
3143 | && lp->status == 0) | |
3144 | { | |
3145 | /* The core wanted the LWP to stop. Even if it stopped | |
3146 | cleanly (with SIGSTOP), leave the event pending. */ | |
3147 | if (debug_linux_nat) | |
3148 | fprintf_unfiltered (gdb_stdlog, | |
3149 | "SARC: core wanted LWP %ld stopped " | |
3150 | "(leaving SIGSTOP pending)\n", | |
3151 | GET_LWP (lp->ptid)); | |
3152 | lp->status = W_STOPCODE (SIGSTOP); | |
3153 | } | |
3154 | ||
3155 | if (lp->status == 0) | |
3156 | { | |
3157 | if (debug_linux_nat) | |
3158 | fprintf_unfiltered (gdb_stdlog, | |
3159 | "SARC: re-resuming LWP %ld\n", | |
3160 | GET_LWP (lp->ptid)); | |
e5ef252a | 3161 | resume_lwp (lp, lp->step, GDB_SIGNAL_0); |
12d9289a PA |
3162 | } |
3163 | else | |
3164 | { | |
3165 | if (debug_linux_nat) | |
3166 | fprintf_unfiltered (gdb_stdlog, | |
3167 | "SARC: not re-resuming LWP %ld " | |
3168 | "(has pending)\n", | |
3169 | GET_LWP (lp->ptid)); | |
3170 | if (new_pending_p) | |
3171 | *new_pending_p = 1; | |
3172 | } | |
25289eb2 | 3173 | } |
d6b0e80f AC |
3174 | } |
3175 | return 0; | |
3176 | } | |
3177 | ||
02f3fc28 | 3178 | /* Check if we should go on and pass this event to common code. |
12d9289a PA |
3179 | Return the affected lwp if we are, or NULL otherwise. If we stop |
3180 | all lwps temporarily, we may end up with new pending events in some | |
3181 | other lwp. In that case set *NEW_PENDING_P to true. */ | |
3182 | ||
02f3fc28 | 3183 | static struct lwp_info * |
0e5bf2a8 | 3184 | linux_nat_filter_event (int lwpid, int status, int *new_pending_p) |
02f3fc28 PA |
3185 | { |
3186 | struct lwp_info *lp; | |
3187 | ||
12d9289a PA |
3188 | *new_pending_p = 0; |
3189 | ||
02f3fc28 PA |
3190 | lp = find_lwp_pid (pid_to_ptid (lwpid)); |
3191 | ||
3192 | /* Check for stop events reported by a process we didn't already | |
3193 | know about - anything not already in our LWP list. | |
3194 | ||
3195 | If we're expecting to receive stopped processes after | |
3196 | fork, vfork, and clone events, then we'll just add the | |
3197 | new one to our list and go back to waiting for the event | |
3198 | to be reported - the stopped process might be returned | |
0e5bf2a8 PA |
3199 | from waitpid before or after the event is. |
3200 | ||
3201 | But note the case of a non-leader thread exec'ing after the | |
3202 | leader having exited, and gone from our lists. The non-leader | |
3203 | thread changes its tid to the tgid. */ | |
3204 | ||
3205 | if (WIFSTOPPED (status) && lp == NULL | |
3206 | && (WSTOPSIG (status) == SIGTRAP && status >> 16 == PTRACE_EVENT_EXEC)) | |
3207 | { | |
3208 | /* A multi-thread exec after we had seen the leader exiting. */ | |
3209 | if (debug_linux_nat) | |
3210 | fprintf_unfiltered (gdb_stdlog, | |
3211 | "LLW: Re-adding thread group leader LWP %d.\n", | |
3212 | lwpid); | |
3213 | ||
3214 | lp = add_lwp (BUILD_LWP (lwpid, lwpid)); | |
3215 | lp->stopped = 1; | |
3216 | lp->resumed = 1; | |
3217 | add_thread (lp->ptid); | |
3218 | } | |
3219 | ||
02f3fc28 PA |
3220 | if (WIFSTOPPED (status) && !lp) |
3221 | { | |
84636d28 | 3222 | add_to_pid_list (&stopped_pids, lwpid, status); |
02f3fc28 PA |
3223 | return NULL; |
3224 | } | |
3225 | ||
3226 | /* Make sure we don't report an event for the exit of an LWP not in | |
1777feb0 | 3227 | our list, i.e. not part of the current process. This can happen |
fd62cb89 | 3228 | if we detach from a program we originally forked and then it |
02f3fc28 PA |
3229 | exits. */ |
3230 | if (!WIFSTOPPED (status) && !lp) | |
3231 | return NULL; | |
3232 | ||
ca2163eb PA |
3233 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
3234 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
3235 | { | |
3236 | /* No longer need the sysgood bit. The ptrace event ends up | |
3237 | recorded in lp->waitstatus if we care for it. We can carry | |
3238 | on handling the event like a regular SIGTRAP from here | |
3239 | on. */ | |
3240 | status = W_STOPCODE (SIGTRAP); | |
3241 | if (linux_handle_syscall_trap (lp, 0)) | |
3242 | return NULL; | |
3243 | } | |
02f3fc28 | 3244 | |
ca2163eb PA |
3245 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
3246 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0) | |
02f3fc28 PA |
3247 | { |
3248 | if (debug_linux_nat) | |
3249 | fprintf_unfiltered (gdb_stdlog, | |
3250 | "LLW: Handling extended status 0x%06x\n", | |
3251 | status); | |
3252 | if (linux_handle_extended_wait (lp, status, 0)) | |
3253 | return NULL; | |
3254 | } | |
3255 | ||
26ab7092 | 3256 | if (linux_nat_status_is_event (status)) |
da559b09 | 3257 | save_sigtrap (lp); |
ca2163eb | 3258 | |
02f3fc28 | 3259 | /* Check if the thread has exited. */ |
d90e17a7 PA |
3260 | if ((WIFEXITED (status) || WIFSIGNALED (status)) |
3261 | && num_lwps (GET_PID (lp->ptid)) > 1) | |
02f3fc28 | 3262 | { |
9db03742 JB |
3263 | /* If this is the main thread, we must stop all threads and verify |
3264 | if they are still alive. This is because in the nptl thread model | |
3265 | on Linux 2.4, there is no signal issued for exiting LWPs | |
02f3fc28 PA |
3266 | other than the main thread. We only get the main thread exit |
3267 | signal once all child threads have already exited. If we | |
3268 | stop all the threads and use the stop_wait_callback to check | |
3269 | if they have exited we can determine whether this signal | |
3270 | should be ignored or whether it means the end of the debugged | |
3271 | application, regardless of which threading model is being | |
5d3b6af6 | 3272 | used. */ |
02f3fc28 PA |
3273 | if (GET_PID (lp->ptid) == GET_LWP (lp->ptid)) |
3274 | { | |
3275 | lp->stopped = 1; | |
d90e17a7 | 3276 | iterate_over_lwps (pid_to_ptid (GET_PID (lp->ptid)), |
12d9289a | 3277 | stop_and_resume_callback, new_pending_p); |
02f3fc28 PA |
3278 | } |
3279 | ||
3280 | if (debug_linux_nat) | |
3281 | fprintf_unfiltered (gdb_stdlog, | |
3282 | "LLW: %s exited.\n", | |
3283 | target_pid_to_str (lp->ptid)); | |
3284 | ||
d90e17a7 | 3285 | if (num_lwps (GET_PID (lp->ptid)) > 1) |
9db03742 JB |
3286 | { |
3287 | /* If there is at least one more LWP, then the exit signal | |
3288 | was not the end of the debugged application and should be | |
3289 | ignored. */ | |
3290 | exit_lwp (lp); | |
3291 | return NULL; | |
3292 | } | |
02f3fc28 PA |
3293 | } |
3294 | ||
3295 | /* Check if the current LWP has previously exited. In the nptl | |
3296 | thread model, LWPs other than the main thread do not issue | |
3297 | signals when they exit so we must check whenever the thread has | |
3298 | stopped. A similar check is made in stop_wait_callback(). */ | |
d90e17a7 | 3299 | if (num_lwps (GET_PID (lp->ptid)) > 1 && !linux_thread_alive (lp->ptid)) |
02f3fc28 | 3300 | { |
d90e17a7 PA |
3301 | ptid_t ptid = pid_to_ptid (GET_PID (lp->ptid)); |
3302 | ||
02f3fc28 PA |
3303 | if (debug_linux_nat) |
3304 | fprintf_unfiltered (gdb_stdlog, | |
3305 | "LLW: %s exited.\n", | |
3306 | target_pid_to_str (lp->ptid)); | |
3307 | ||
3308 | exit_lwp (lp); | |
3309 | ||
3310 | /* Make sure there is at least one thread running. */ | |
d90e17a7 | 3311 | gdb_assert (iterate_over_lwps (ptid, running_callback, NULL)); |
02f3fc28 PA |
3312 | |
3313 | /* Discard the event. */ | |
3314 | return NULL; | |
3315 | } | |
3316 | ||
3317 | /* Make sure we don't report a SIGSTOP that we sent ourselves in | |
3318 | an attempt to stop an LWP. */ | |
3319 | if (lp->signalled | |
3320 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) | |
3321 | { | |
3322 | if (debug_linux_nat) | |
3323 | fprintf_unfiltered (gdb_stdlog, | |
3324 | "LLW: Delayed SIGSTOP caught for %s.\n", | |
3325 | target_pid_to_str (lp->ptid)); | |
3326 | ||
02f3fc28 PA |
3327 | lp->signalled = 0; |
3328 | ||
25289eb2 PA |
3329 | if (lp->last_resume_kind != resume_stop) |
3330 | { | |
3331 | /* This is a delayed SIGSTOP. */ | |
02f3fc28 | 3332 | |
25289eb2 PA |
3333 | registers_changed (); |
3334 | ||
7b50312a PA |
3335 | if (linux_nat_prepare_to_resume != NULL) |
3336 | linux_nat_prepare_to_resume (lp); | |
25289eb2 | 3337 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
a493e3e2 | 3338 | lp->step, GDB_SIGNAL_0); |
25289eb2 PA |
3339 | if (debug_linux_nat) |
3340 | fprintf_unfiltered (gdb_stdlog, | |
3341 | "LLW: %s %s, 0, 0 (discard SIGSTOP)\n", | |
3342 | lp->step ? | |
3343 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3344 | target_pid_to_str (lp->ptid)); | |
02f3fc28 | 3345 | |
25289eb2 PA |
3346 | lp->stopped = 0; |
3347 | gdb_assert (lp->resumed); | |
02f3fc28 | 3348 | |
25289eb2 PA |
3349 | /* Discard the event. */ |
3350 | return NULL; | |
3351 | } | |
02f3fc28 PA |
3352 | } |
3353 | ||
57380f4e DJ |
3354 | /* Make sure we don't report a SIGINT that we have already displayed |
3355 | for another thread. */ | |
3356 | if (lp->ignore_sigint | |
3357 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) | |
3358 | { | |
3359 | if (debug_linux_nat) | |
3360 | fprintf_unfiltered (gdb_stdlog, | |
3361 | "LLW: Delayed SIGINT caught for %s.\n", | |
3362 | target_pid_to_str (lp->ptid)); | |
3363 | ||
3364 | /* This is a delayed SIGINT. */ | |
3365 | lp->ignore_sigint = 0; | |
3366 | ||
3367 | registers_changed (); | |
7b50312a PA |
3368 | if (linux_nat_prepare_to_resume != NULL) |
3369 | linux_nat_prepare_to_resume (lp); | |
28439f5e | 3370 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
a493e3e2 | 3371 | lp->step, GDB_SIGNAL_0); |
57380f4e DJ |
3372 | if (debug_linux_nat) |
3373 | fprintf_unfiltered (gdb_stdlog, | |
3374 | "LLW: %s %s, 0, 0 (discard SIGINT)\n", | |
3375 | lp->step ? | |
3376 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3377 | target_pid_to_str (lp->ptid)); | |
3378 | ||
3379 | lp->stopped = 0; | |
3380 | gdb_assert (lp->resumed); | |
3381 | ||
3382 | /* Discard the event. */ | |
3383 | return NULL; | |
3384 | } | |
3385 | ||
02f3fc28 PA |
3386 | /* An interesting event. */ |
3387 | gdb_assert (lp); | |
ca2163eb | 3388 | lp->status = status; |
02f3fc28 PA |
3389 | return lp; |
3390 | } | |
3391 | ||
0e5bf2a8 PA |
3392 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
3393 | their exits until all other threads in the group have exited. */ | |
3394 | ||
3395 | static void | |
3396 | check_zombie_leaders (void) | |
3397 | { | |
3398 | struct inferior *inf; | |
3399 | ||
3400 | ALL_INFERIORS (inf) | |
3401 | { | |
3402 | struct lwp_info *leader_lp; | |
3403 | ||
3404 | if (inf->pid == 0) | |
3405 | continue; | |
3406 | ||
3407 | leader_lp = find_lwp_pid (pid_to_ptid (inf->pid)); | |
3408 | if (leader_lp != NULL | |
3409 | /* Check if there are other threads in the group, as we may | |
3410 | have raced with the inferior simply exiting. */ | |
3411 | && num_lwps (inf->pid) > 1 | |
5f572dec | 3412 | && linux_proc_pid_is_zombie (inf->pid)) |
0e5bf2a8 PA |
3413 | { |
3414 | if (debug_linux_nat) | |
3415 | fprintf_unfiltered (gdb_stdlog, | |
3416 | "CZL: Thread group leader %d zombie " | |
3417 | "(it exited, or another thread execd).\n", | |
3418 | inf->pid); | |
3419 | ||
3420 | /* A leader zombie can mean one of two things: | |
3421 | ||
3422 | - It exited, and there's an exit status pending | |
3423 | available, or only the leader exited (not the whole | |
3424 | program). In the latter case, we can't waitpid the | |
3425 | leader's exit status until all other threads are gone. | |
3426 | ||
3427 | - There are 3 or more threads in the group, and a thread | |
3428 | other than the leader exec'd. On an exec, the Linux | |
3429 | kernel destroys all other threads (except the execing | |
3430 | one) in the thread group, and resets the execing thread's | |
3431 | tid to the tgid. No exit notification is sent for the | |
3432 | execing thread -- from the ptracer's perspective, it | |
3433 | appears as though the execing thread just vanishes. | |
3434 | Until we reap all other threads except the leader and the | |
3435 | execing thread, the leader will be zombie, and the | |
3436 | execing thread will be in `D (disc sleep)'. As soon as | |
3437 | all other threads are reaped, the execing thread changes | |
3438 | it's tid to the tgid, and the previous (zombie) leader | |
3439 | vanishes, giving place to the "new" leader. We could try | |
3440 | distinguishing the exit and exec cases, by waiting once | |
3441 | more, and seeing if something comes out, but it doesn't | |
3442 | sound useful. The previous leader _does_ go away, and | |
3443 | we'll re-add the new one once we see the exec event | |
3444 | (which is just the same as what would happen if the | |
3445 | previous leader did exit voluntarily before some other | |
3446 | thread execs). */ | |
3447 | ||
3448 | if (debug_linux_nat) | |
3449 | fprintf_unfiltered (gdb_stdlog, | |
3450 | "CZL: Thread group leader %d vanished.\n", | |
3451 | inf->pid); | |
3452 | exit_lwp (leader_lp); | |
3453 | } | |
3454 | } | |
3455 | } | |
3456 | ||
d6b0e80f | 3457 | static ptid_t |
7feb7d06 | 3458 | linux_nat_wait_1 (struct target_ops *ops, |
47608cb1 PA |
3459 | ptid_t ptid, struct target_waitstatus *ourstatus, |
3460 | int target_options) | |
d6b0e80f | 3461 | { |
7feb7d06 | 3462 | static sigset_t prev_mask; |
4b60df3d | 3463 | enum resume_kind last_resume_kind; |
12d9289a | 3464 | struct lwp_info *lp; |
12d9289a | 3465 | int status; |
d6b0e80f | 3466 | |
01124a23 | 3467 | if (debug_linux_nat) |
b84876c2 PA |
3468 | fprintf_unfiltered (gdb_stdlog, "LLW: enter\n"); |
3469 | ||
f973ed9c DJ |
3470 | /* The first time we get here after starting a new inferior, we may |
3471 | not have added it to the LWP list yet - this is the earliest | |
3472 | moment at which we know its PID. */ | |
d90e17a7 | 3473 | if (ptid_is_pid (inferior_ptid)) |
f973ed9c | 3474 | { |
27c9d204 PA |
3475 | /* Upgrade the main thread's ptid. */ |
3476 | thread_change_ptid (inferior_ptid, | |
3477 | BUILD_LWP (GET_PID (inferior_ptid), | |
3478 | GET_PID (inferior_ptid))); | |
3479 | ||
26cb8b7c | 3480 | lp = add_initial_lwp (inferior_ptid); |
f973ed9c DJ |
3481 | lp->resumed = 1; |
3482 | } | |
3483 | ||
7feb7d06 PA |
3484 | /* Make sure SIGCHLD is blocked. */ |
3485 | block_child_signals (&prev_mask); | |
d6b0e80f AC |
3486 | |
3487 | retry: | |
d90e17a7 PA |
3488 | lp = NULL; |
3489 | status = 0; | |
d6b0e80f AC |
3490 | |
3491 | /* First check if there is a LWP with a wait status pending. */ | |
0e5bf2a8 | 3492 | if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) |
d6b0e80f | 3493 | { |
0e5bf2a8 | 3494 | /* Any LWP in the PTID group that's been resumed will do. */ |
d90e17a7 | 3495 | lp = iterate_over_lwps (ptid, status_callback, NULL); |
d6b0e80f AC |
3496 | if (lp) |
3497 | { | |
ca2163eb | 3498 | if (debug_linux_nat && lp->status) |
d6b0e80f AC |
3499 | fprintf_unfiltered (gdb_stdlog, |
3500 | "LLW: Using pending wait status %s for %s.\n", | |
ca2163eb | 3501 | status_to_str (lp->status), |
d6b0e80f AC |
3502 | target_pid_to_str (lp->ptid)); |
3503 | } | |
d6b0e80f AC |
3504 | } |
3505 | else if (is_lwp (ptid)) | |
3506 | { | |
3507 | if (debug_linux_nat) | |
3508 | fprintf_unfiltered (gdb_stdlog, | |
3509 | "LLW: Waiting for specific LWP %s.\n", | |
3510 | target_pid_to_str (ptid)); | |
3511 | ||
3512 | /* We have a specific LWP to check. */ | |
3513 | lp = find_lwp_pid (ptid); | |
3514 | gdb_assert (lp); | |
d6b0e80f | 3515 | |
ca2163eb | 3516 | if (debug_linux_nat && lp->status) |
d6b0e80f AC |
3517 | fprintf_unfiltered (gdb_stdlog, |
3518 | "LLW: Using pending wait status %s for %s.\n", | |
ca2163eb | 3519 | status_to_str (lp->status), |
d6b0e80f AC |
3520 | target_pid_to_str (lp->ptid)); |
3521 | ||
d90e17a7 PA |
3522 | /* We check for lp->waitstatus in addition to lp->status, |
3523 | because we can have pending process exits recorded in | |
3524 | lp->status and W_EXITCODE(0,0) == 0. We should probably have | |
3525 | an additional lp->status_p flag. */ | |
ca2163eb | 3526 | if (lp->status == 0 && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) |
d90e17a7 | 3527 | lp = NULL; |
d6b0e80f AC |
3528 | } |
3529 | ||
b84876c2 PA |
3530 | if (!target_can_async_p ()) |
3531 | { | |
3532 | /* Causes SIGINT to be passed on to the attached process. */ | |
3533 | set_sigint_trap (); | |
b84876c2 | 3534 | } |
d6b0e80f | 3535 | |
0e5bf2a8 | 3536 | /* But if we don't find a pending event, we'll have to wait. */ |
7feb7d06 | 3537 | |
d90e17a7 | 3538 | while (lp == NULL) |
d6b0e80f AC |
3539 | { |
3540 | pid_t lwpid; | |
3541 | ||
0e5bf2a8 PA |
3542 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
3543 | quirks: | |
3544 | ||
3545 | - If the thread group leader exits while other threads in the | |
3546 | thread group still exist, waitpid(TGID, ...) hangs. That | |
3547 | waitpid won't return an exit status until the other threads | |
3548 | in the group are reapped. | |
3549 | ||
3550 | - When a non-leader thread execs, that thread just vanishes | |
3551 | without reporting an exit (so we'd hang if we waited for it | |
3552 | explicitly in that case). The exec event is reported to | |
3553 | the TGID pid. */ | |
3554 | ||
3555 | errno = 0; | |
3556 | lwpid = my_waitpid (-1, &status, __WCLONE | WNOHANG); | |
3557 | if (lwpid == 0 || (lwpid == -1 && errno == ECHILD)) | |
3558 | lwpid = my_waitpid (-1, &status, WNOHANG); | |
3559 | ||
3560 | if (debug_linux_nat) | |
3561 | fprintf_unfiltered (gdb_stdlog, | |
3562 | "LNW: waitpid(-1, ...) returned %d, %s\n", | |
3563 | lwpid, errno ? safe_strerror (errno) : "ERRNO-OK"); | |
b84876c2 | 3564 | |
d6b0e80f AC |
3565 | if (lwpid > 0) |
3566 | { | |
12d9289a PA |
3567 | /* If this is true, then we paused LWPs momentarily, and may |
3568 | now have pending events to handle. */ | |
3569 | int new_pending; | |
3570 | ||
d6b0e80f AC |
3571 | if (debug_linux_nat) |
3572 | { | |
3573 | fprintf_unfiltered (gdb_stdlog, | |
3574 | "LLW: waitpid %ld received %s\n", | |
3575 | (long) lwpid, status_to_str (status)); | |
3576 | } | |
3577 | ||
0e5bf2a8 | 3578 | lp = linux_nat_filter_event (lwpid, status, &new_pending); |
d90e17a7 | 3579 | |
33355866 JK |
3580 | /* STATUS is now no longer valid, use LP->STATUS instead. */ |
3581 | status = 0; | |
3582 | ||
0e5bf2a8 | 3583 | if (lp && !ptid_match (lp->ptid, ptid)) |
d6b0e80f | 3584 | { |
e3e9f5a2 PA |
3585 | gdb_assert (lp->resumed); |
3586 | ||
d90e17a7 | 3587 | if (debug_linux_nat) |
3e43a32a MS |
3588 | fprintf (stderr, |
3589 | "LWP %ld got an event %06x, leaving pending.\n", | |
33355866 | 3590 | ptid_get_lwp (lp->ptid), lp->status); |
d90e17a7 | 3591 | |
ca2163eb | 3592 | if (WIFSTOPPED (lp->status)) |
d90e17a7 | 3593 | { |
ca2163eb | 3594 | if (WSTOPSIG (lp->status) != SIGSTOP) |
d90e17a7 | 3595 | { |
e3e9f5a2 PA |
3596 | /* Cancel breakpoint hits. The breakpoint may |
3597 | be removed before we fetch events from this | |
3598 | process to report to the core. It is best | |
3599 | not to assume the moribund breakpoints | |
3600 | heuristic always handles these cases --- it | |
3601 | could be too many events go through to the | |
3602 | core before this one is handled. All-stop | |
3603 | always cancels breakpoint hits in all | |
3604 | threads. */ | |
3605 | if (non_stop | |
00390b84 | 3606 | && linux_nat_lp_status_is_event (lp) |
e3e9f5a2 PA |
3607 | && cancel_breakpoint (lp)) |
3608 | { | |
3609 | /* Throw away the SIGTRAP. */ | |
3610 | lp->status = 0; | |
3611 | ||
3612 | if (debug_linux_nat) | |
3613 | fprintf (stderr, | |
3e43a32a MS |
3614 | "LLW: LWP %ld hit a breakpoint while" |
3615 | " waiting for another process;" | |
3616 | " cancelled it\n", | |
e3e9f5a2 PA |
3617 | ptid_get_lwp (lp->ptid)); |
3618 | } | |
3619 | lp->stopped = 1; | |
d90e17a7 PA |
3620 | } |
3621 | else | |
3622 | { | |
3623 | lp->stopped = 1; | |
3624 | lp->signalled = 0; | |
3625 | } | |
3626 | } | |
33355866 | 3627 | else if (WIFEXITED (lp->status) || WIFSIGNALED (lp->status)) |
d90e17a7 PA |
3628 | { |
3629 | if (debug_linux_nat) | |
3e43a32a MS |
3630 | fprintf (stderr, |
3631 | "Process %ld exited while stopping LWPs\n", | |
d90e17a7 PA |
3632 | ptid_get_lwp (lp->ptid)); |
3633 | ||
3634 | /* This was the last lwp in the process. Since | |
3635 | events are serialized to GDB core, and we can't | |
3636 | report this one right now, but GDB core and the | |
3637 | other target layers will want to be notified | |
3638 | about the exit code/signal, leave the status | |
3639 | pending for the next time we're able to report | |
3640 | it. */ | |
d90e17a7 PA |
3641 | |
3642 | /* Prevent trying to stop this thread again. We'll | |
3643 | never try to resume it because it has a pending | |
3644 | status. */ | |
3645 | lp->stopped = 1; | |
3646 | ||
3647 | /* Dead LWP's aren't expected to reported a pending | |
3648 | sigstop. */ | |
3649 | lp->signalled = 0; | |
3650 | ||
3651 | /* Store the pending event in the waitstatus as | |
3652 | well, because W_EXITCODE(0,0) == 0. */ | |
ca2163eb | 3653 | store_waitstatus (&lp->waitstatus, lp->status); |
d90e17a7 PA |
3654 | } |
3655 | ||
3656 | /* Keep looking. */ | |
3657 | lp = NULL; | |
d6b0e80f AC |
3658 | } |
3659 | ||
0e5bf2a8 | 3660 | if (new_pending) |
d90e17a7 | 3661 | { |
0e5bf2a8 PA |
3662 | /* Some LWP now has a pending event. Go all the way |
3663 | back to check it. */ | |
3664 | goto retry; | |
3665 | } | |
12d9289a | 3666 | |
0e5bf2a8 PA |
3667 | if (lp) |
3668 | { | |
3669 | /* We got an event to report to the core. */ | |
3670 | break; | |
d90e17a7 | 3671 | } |
0e5bf2a8 PA |
3672 | |
3673 | /* Retry until nothing comes out of waitpid. A single | |
3674 | SIGCHLD can indicate more than one child stopped. */ | |
3675 | continue; | |
d6b0e80f AC |
3676 | } |
3677 | ||
0e5bf2a8 PA |
3678 | /* Check for zombie thread group leaders. Those can't be reaped |
3679 | until all other threads in the thread group are. */ | |
3680 | check_zombie_leaders (); | |
d6b0e80f | 3681 | |
0e5bf2a8 PA |
3682 | /* If there are no resumed children left, bail. We'd be stuck |
3683 | forever in the sigsuspend call below otherwise. */ | |
3684 | if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL) | |
3685 | { | |
3686 | if (debug_linux_nat) | |
3687 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n"); | |
b84876c2 | 3688 | |
0e5bf2a8 | 3689 | ourstatus->kind = TARGET_WAITKIND_NO_RESUMED; |
b84876c2 | 3690 | |
0e5bf2a8 PA |
3691 | if (!target_can_async_p ()) |
3692 | clear_sigint_trap (); | |
b84876c2 | 3693 | |
0e5bf2a8 PA |
3694 | restore_child_signals_mask (&prev_mask); |
3695 | return minus_one_ptid; | |
d6b0e80f | 3696 | } |
28736962 | 3697 | |
0e5bf2a8 PA |
3698 | /* No interesting event to report to the core. */ |
3699 | ||
3700 | if (target_options & TARGET_WNOHANG) | |
3701 | { | |
01124a23 | 3702 | if (debug_linux_nat) |
28736962 PA |
3703 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n"); |
3704 | ||
0e5bf2a8 | 3705 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
28736962 PA |
3706 | restore_child_signals_mask (&prev_mask); |
3707 | return minus_one_ptid; | |
3708 | } | |
d6b0e80f AC |
3709 | |
3710 | /* We shouldn't end up here unless we want to try again. */ | |
d90e17a7 | 3711 | gdb_assert (lp == NULL); |
0e5bf2a8 PA |
3712 | |
3713 | /* Block until we get an event reported with SIGCHLD. */ | |
3714 | sigsuspend (&suspend_mask); | |
d6b0e80f AC |
3715 | } |
3716 | ||
b84876c2 | 3717 | if (!target_can_async_p ()) |
d26b5354 | 3718 | clear_sigint_trap (); |
d6b0e80f AC |
3719 | |
3720 | gdb_assert (lp); | |
3721 | ||
ca2163eb PA |
3722 | status = lp->status; |
3723 | lp->status = 0; | |
3724 | ||
d6b0e80f AC |
3725 | /* Don't report signals that GDB isn't interested in, such as |
3726 | signals that are neither printed nor stopped upon. Stopping all | |
3727 | threads can be a bit time-consuming so if we want decent | |
3728 | performance with heavily multi-threaded programs, especially when | |
3729 | they're using a high frequency timer, we'd better avoid it if we | |
3730 | can. */ | |
3731 | ||
3732 | if (WIFSTOPPED (status)) | |
3733 | { | |
2ea28649 | 3734 | enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status)); |
d6b0e80f | 3735 | |
2455069d UW |
3736 | /* When using hardware single-step, we need to report every signal. |
3737 | Otherwise, signals in pass_mask may be short-circuited. */ | |
d539ed7e | 3738 | if (!lp->step |
2455069d | 3739 | && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status))) |
d6b0e80f AC |
3740 | { |
3741 | /* FIMXE: kettenis/2001-06-06: Should we resume all threads | |
3742 | here? It is not clear we should. GDB may not expect | |
3743 | other threads to run. On the other hand, not resuming | |
3744 | newly attached threads may cause an unwanted delay in | |
3745 | getting them running. */ | |
3746 | registers_changed (); | |
7b50312a PA |
3747 | if (linux_nat_prepare_to_resume != NULL) |
3748 | linux_nat_prepare_to_resume (lp); | |
28439f5e | 3749 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
10d6c8cd | 3750 | lp->step, signo); |
d6b0e80f AC |
3751 | if (debug_linux_nat) |
3752 | fprintf_unfiltered (gdb_stdlog, | |
3753 | "LLW: %s %s, %s (preempt 'handle')\n", | |
3754 | lp->step ? | |
3755 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3756 | target_pid_to_str (lp->ptid), | |
a493e3e2 | 3757 | (signo != GDB_SIGNAL_0 |
2ea28649 | 3758 | ? strsignal (gdb_signal_to_host (signo)) |
423ec54c | 3759 | : "0")); |
d6b0e80f | 3760 | lp->stopped = 0; |
d6b0e80f AC |
3761 | goto retry; |
3762 | } | |
3763 | ||
1ad15515 | 3764 | if (!non_stop) |
d6b0e80f | 3765 | { |
1ad15515 PA |
3766 | /* Only do the below in all-stop, as we currently use SIGINT |
3767 | to implement target_stop (see linux_nat_stop) in | |
3768 | non-stop. */ | |
a493e3e2 | 3769 | if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0) |
1ad15515 PA |
3770 | { |
3771 | /* If ^C/BREAK is typed at the tty/console, SIGINT gets | |
3772 | forwarded to the entire process group, that is, all LWPs | |
3773 | will receive it - unless they're using CLONE_THREAD to | |
3774 | share signals. Since we only want to report it once, we | |
3775 | mark it as ignored for all LWPs except this one. */ | |
d90e17a7 PA |
3776 | iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid)), |
3777 | set_ignore_sigint, NULL); | |
1ad15515 PA |
3778 | lp->ignore_sigint = 0; |
3779 | } | |
3780 | else | |
3781 | maybe_clear_ignore_sigint (lp); | |
d6b0e80f AC |
3782 | } |
3783 | } | |
3784 | ||
3785 | /* This LWP is stopped now. */ | |
3786 | lp->stopped = 1; | |
3787 | ||
3788 | if (debug_linux_nat) | |
3789 | fprintf_unfiltered (gdb_stdlog, "LLW: Candidate event %s in %s.\n", | |
3790 | status_to_str (status), target_pid_to_str (lp->ptid)); | |
3791 | ||
4c28f408 PA |
3792 | if (!non_stop) |
3793 | { | |
3794 | /* Now stop all other LWP's ... */ | |
d90e17a7 | 3795 | iterate_over_lwps (minus_one_ptid, stop_callback, NULL); |
4c28f408 PA |
3796 | |
3797 | /* ... and wait until all of them have reported back that | |
3798 | they're no longer running. */ | |
d90e17a7 | 3799 | iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL); |
4c28f408 PA |
3800 | |
3801 | /* If we're not waiting for a specific LWP, choose an event LWP | |
3802 | from among those that have had events. Giving equal priority | |
3803 | to all LWPs that have had events helps prevent | |
3804 | starvation. */ | |
0e5bf2a8 | 3805 | if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) |
d90e17a7 | 3806 | select_event_lwp (ptid, &lp, &status); |
d6b0e80f | 3807 | |
e3e9f5a2 PA |
3808 | /* Now that we've selected our final event LWP, cancel any |
3809 | breakpoints in other LWPs that have hit a GDB breakpoint. | |
3810 | See the comment in cancel_breakpoints_callback to find out | |
3811 | why. */ | |
3812 | iterate_over_lwps (minus_one_ptid, cancel_breakpoints_callback, lp); | |
3813 | ||
4b60df3d PA |
3814 | /* We'll need this to determine whether to report a SIGSTOP as |
3815 | TARGET_WAITKIND_0. Need to take a copy because | |
3816 | resume_clear_callback clears it. */ | |
3817 | last_resume_kind = lp->last_resume_kind; | |
3818 | ||
e3e9f5a2 PA |
3819 | /* In all-stop, from the core's perspective, all LWPs are now |
3820 | stopped until a new resume action is sent over. */ | |
3821 | iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL); | |
3822 | } | |
3823 | else | |
25289eb2 | 3824 | { |
4b60df3d PA |
3825 | /* See above. */ |
3826 | last_resume_kind = lp->last_resume_kind; | |
3827 | resume_clear_callback (lp, NULL); | |
25289eb2 | 3828 | } |
d6b0e80f | 3829 | |
26ab7092 | 3830 | if (linux_nat_status_is_event (status)) |
d6b0e80f | 3831 | { |
d6b0e80f AC |
3832 | if (debug_linux_nat) |
3833 | fprintf_unfiltered (gdb_stdlog, | |
4fdebdd0 PA |
3834 | "LLW: trap ptid is %s.\n", |
3835 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 3836 | } |
d6b0e80f AC |
3837 | |
3838 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
3839 | { | |
3840 | *ourstatus = lp->waitstatus; | |
3841 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
3842 | } | |
3843 | else | |
3844 | store_waitstatus (ourstatus, status); | |
3845 | ||
01124a23 | 3846 | if (debug_linux_nat) |
b84876c2 PA |
3847 | fprintf_unfiltered (gdb_stdlog, "LLW: exit\n"); |
3848 | ||
7feb7d06 | 3849 | restore_child_signals_mask (&prev_mask); |
1e225492 | 3850 | |
4b60df3d | 3851 | if (last_resume_kind == resume_stop |
25289eb2 PA |
3852 | && ourstatus->kind == TARGET_WAITKIND_STOPPED |
3853 | && WSTOPSIG (status) == SIGSTOP) | |
3854 | { | |
3855 | /* A thread that has been requested to stop by GDB with | |
3856 | target_stop, and it stopped cleanly, so report as SIG0. The | |
3857 | use of SIGSTOP is an implementation detail. */ | |
a493e3e2 | 3858 | ourstatus->value.sig = GDB_SIGNAL_0; |
25289eb2 PA |
3859 | } |
3860 | ||
1e225492 JK |
3861 | if (ourstatus->kind == TARGET_WAITKIND_EXITED |
3862 | || ourstatus->kind == TARGET_WAITKIND_SIGNALLED) | |
3863 | lp->core = -1; | |
3864 | else | |
2e794194 | 3865 | lp->core = linux_common_core_of_thread (lp->ptid); |
1e225492 | 3866 | |
f973ed9c | 3867 | return lp->ptid; |
d6b0e80f AC |
3868 | } |
3869 | ||
e3e9f5a2 PA |
3870 | /* Resume LWPs that are currently stopped without any pending status |
3871 | to report, but are resumed from the core's perspective. */ | |
3872 | ||
3873 | static int | |
3874 | resume_stopped_resumed_lwps (struct lwp_info *lp, void *data) | |
3875 | { | |
3876 | ptid_t *wait_ptid_p = data; | |
3877 | ||
3878 | if (lp->stopped | |
3879 | && lp->resumed | |
3880 | && lp->status == 0 | |
3881 | && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) | |
3882 | { | |
336060f3 PA |
3883 | struct regcache *regcache = get_thread_regcache (lp->ptid); |
3884 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
3885 | CORE_ADDR pc = regcache_read_pc (regcache); | |
3886 | ||
e3e9f5a2 PA |
3887 | gdb_assert (is_executing (lp->ptid)); |
3888 | ||
3889 | /* Don't bother if there's a breakpoint at PC that we'd hit | |
3890 | immediately, and we're not waiting for this LWP. */ | |
3891 | if (!ptid_match (lp->ptid, *wait_ptid_p)) | |
3892 | { | |
e3e9f5a2 PA |
3893 | if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
3894 | return 0; | |
3895 | } | |
3896 | ||
3897 | if (debug_linux_nat) | |
3898 | fprintf_unfiltered (gdb_stdlog, | |
336060f3 PA |
3899 | "RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n", |
3900 | target_pid_to_str (lp->ptid), | |
3901 | paddress (gdbarch, pc), | |
3902 | lp->step); | |
e3e9f5a2 | 3903 | |
336060f3 | 3904 | registers_changed (); |
7b50312a PA |
3905 | if (linux_nat_prepare_to_resume != NULL) |
3906 | linux_nat_prepare_to_resume (lp); | |
e3e9f5a2 | 3907 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
a493e3e2 | 3908 | lp->step, GDB_SIGNAL_0); |
e3e9f5a2 | 3909 | lp->stopped = 0; |
e3e9f5a2 PA |
3910 | lp->stopped_by_watchpoint = 0; |
3911 | } | |
3912 | ||
3913 | return 0; | |
3914 | } | |
3915 | ||
7feb7d06 PA |
3916 | static ptid_t |
3917 | linux_nat_wait (struct target_ops *ops, | |
47608cb1 PA |
3918 | ptid_t ptid, struct target_waitstatus *ourstatus, |
3919 | int target_options) | |
7feb7d06 PA |
3920 | { |
3921 | ptid_t event_ptid; | |
3922 | ||
3923 | if (debug_linux_nat) | |
09826ec5 PA |
3924 | { |
3925 | char *options_string; | |
3926 | ||
3927 | options_string = target_options_to_string (target_options); | |
3928 | fprintf_unfiltered (gdb_stdlog, | |
3929 | "linux_nat_wait: [%s], [%s]\n", | |
3930 | target_pid_to_str (ptid), | |
3931 | options_string); | |
3932 | xfree (options_string); | |
3933 | } | |
7feb7d06 PA |
3934 | |
3935 | /* Flush the async file first. */ | |
3936 | if (target_can_async_p ()) | |
3937 | async_file_flush (); | |
3938 | ||
e3e9f5a2 PA |
3939 | /* Resume LWPs that are currently stopped without any pending status |
3940 | to report, but are resumed from the core's perspective. LWPs get | |
3941 | in this state if we find them stopping at a time we're not | |
3942 | interested in reporting the event (target_wait on a | |
3943 | specific_process, for example, see linux_nat_wait_1), and | |
3944 | meanwhile the event became uninteresting. Don't bother resuming | |
3945 | LWPs we're not going to wait for if they'd stop immediately. */ | |
3946 | if (non_stop) | |
3947 | iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid); | |
3948 | ||
47608cb1 | 3949 | event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options); |
7feb7d06 PA |
3950 | |
3951 | /* If we requested any event, and something came out, assume there | |
3952 | may be more. If we requested a specific lwp or process, also | |
3953 | assume there may be more. */ | |
3954 | if (target_can_async_p () | |
6953d224 PA |
3955 | && ((ourstatus->kind != TARGET_WAITKIND_IGNORE |
3956 | && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED) | |
7feb7d06 PA |
3957 | || !ptid_equal (ptid, minus_one_ptid))) |
3958 | async_file_mark (); | |
3959 | ||
3960 | /* Get ready for the next event. */ | |
3961 | if (target_can_async_p ()) | |
3962 | target_async (inferior_event_handler, 0); | |
3963 | ||
3964 | return event_ptid; | |
3965 | } | |
3966 | ||
d6b0e80f AC |
3967 | static int |
3968 | kill_callback (struct lwp_info *lp, void *data) | |
3969 | { | |
ed731959 JK |
3970 | /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
3971 | ||
3972 | errno = 0; | |
3973 | kill (GET_LWP (lp->ptid), SIGKILL); | |
3974 | if (debug_linux_nat) | |
3975 | fprintf_unfiltered (gdb_stdlog, | |
3976 | "KC: kill (SIGKILL) %s, 0, 0 (%s)\n", | |
3977 | target_pid_to_str (lp->ptid), | |
3978 | errno ? safe_strerror (errno) : "OK"); | |
3979 | ||
3980 | /* Some kernels ignore even SIGKILL for processes under ptrace. */ | |
3981 | ||
d6b0e80f AC |
3982 | errno = 0; |
3983 | ptrace (PTRACE_KILL, GET_LWP (lp->ptid), 0, 0); | |
3984 | if (debug_linux_nat) | |
3985 | fprintf_unfiltered (gdb_stdlog, | |
3986 | "KC: PTRACE_KILL %s, 0, 0 (%s)\n", | |
3987 | target_pid_to_str (lp->ptid), | |
3988 | errno ? safe_strerror (errno) : "OK"); | |
3989 | ||
3990 | return 0; | |
3991 | } | |
3992 | ||
3993 | static int | |
3994 | kill_wait_callback (struct lwp_info *lp, void *data) | |
3995 | { | |
3996 | pid_t pid; | |
3997 | ||
3998 | /* We must make sure that there are no pending events (delayed | |
3999 | SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current | |
4000 | program doesn't interfere with any following debugging session. */ | |
4001 | ||
4002 | /* For cloned processes we must check both with __WCLONE and | |
4003 | without, since the exit status of a cloned process isn't reported | |
4004 | with __WCLONE. */ | |
4005 | if (lp->cloned) | |
4006 | { | |
4007 | do | |
4008 | { | |
58aecb61 | 4009 | pid = my_waitpid (GET_LWP (lp->ptid), NULL, __WCLONE); |
e85a822c | 4010 | if (pid != (pid_t) -1) |
d6b0e80f | 4011 | { |
e85a822c DJ |
4012 | if (debug_linux_nat) |
4013 | fprintf_unfiltered (gdb_stdlog, | |
4014 | "KWC: wait %s received unknown.\n", | |
4015 | target_pid_to_str (lp->ptid)); | |
4016 | /* The Linux kernel sometimes fails to kill a thread | |
4017 | completely after PTRACE_KILL; that goes from the stop | |
4018 | point in do_fork out to the one in | |
4019 | get_signal_to_deliever and waits again. So kill it | |
4020 | again. */ | |
4021 | kill_callback (lp, NULL); | |
d6b0e80f AC |
4022 | } |
4023 | } | |
4024 | while (pid == GET_LWP (lp->ptid)); | |
4025 | ||
4026 | gdb_assert (pid == -1 && errno == ECHILD); | |
4027 | } | |
4028 | ||
4029 | do | |
4030 | { | |
58aecb61 | 4031 | pid = my_waitpid (GET_LWP (lp->ptid), NULL, 0); |
e85a822c | 4032 | if (pid != (pid_t) -1) |
d6b0e80f | 4033 | { |
e85a822c DJ |
4034 | if (debug_linux_nat) |
4035 | fprintf_unfiltered (gdb_stdlog, | |
4036 | "KWC: wait %s received unk.\n", | |
4037 | target_pid_to_str (lp->ptid)); | |
4038 | /* See the call to kill_callback above. */ | |
4039 | kill_callback (lp, NULL); | |
d6b0e80f AC |
4040 | } |
4041 | } | |
4042 | while (pid == GET_LWP (lp->ptid)); | |
4043 | ||
4044 | gdb_assert (pid == -1 && errno == ECHILD); | |
4045 | return 0; | |
4046 | } | |
4047 | ||
4048 | static void | |
7d85a9c0 | 4049 | linux_nat_kill (struct target_ops *ops) |
d6b0e80f | 4050 | { |
f973ed9c DJ |
4051 | struct target_waitstatus last; |
4052 | ptid_t last_ptid; | |
4053 | int status; | |
d6b0e80f | 4054 | |
f973ed9c DJ |
4055 | /* If we're stopped while forking and we haven't followed yet, |
4056 | kill the other task. We need to do this first because the | |
4057 | parent will be sleeping if this is a vfork. */ | |
d6b0e80f | 4058 | |
f973ed9c | 4059 | get_last_target_status (&last_ptid, &last); |
d6b0e80f | 4060 | |
f973ed9c DJ |
4061 | if (last.kind == TARGET_WAITKIND_FORKED |
4062 | || last.kind == TARGET_WAITKIND_VFORKED) | |
4063 | { | |
3a3e9ee3 | 4064 | ptrace (PT_KILL, PIDGET (last.value.related_pid), 0, 0); |
f973ed9c | 4065 | wait (&status); |
26cb8b7c PA |
4066 | |
4067 | /* Let the arch-specific native code know this process is | |
4068 | gone. */ | |
4069 | linux_nat_forget_process (PIDGET (last.value.related_pid)); | |
f973ed9c DJ |
4070 | } |
4071 | ||
4072 | if (forks_exist_p ()) | |
7feb7d06 | 4073 | linux_fork_killall (); |
f973ed9c DJ |
4074 | else |
4075 | { | |
d90e17a7 | 4076 | ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid)); |
e0881a8e | 4077 | |
4c28f408 PA |
4078 | /* Stop all threads before killing them, since ptrace requires |
4079 | that the thread is stopped to sucessfully PTRACE_KILL. */ | |
d90e17a7 | 4080 | iterate_over_lwps (ptid, stop_callback, NULL); |
4c28f408 PA |
4081 | /* ... and wait until all of them have reported back that |
4082 | they're no longer running. */ | |
d90e17a7 | 4083 | iterate_over_lwps (ptid, stop_wait_callback, NULL); |
4c28f408 | 4084 | |
f973ed9c | 4085 | /* Kill all LWP's ... */ |
d90e17a7 | 4086 | iterate_over_lwps (ptid, kill_callback, NULL); |
f973ed9c DJ |
4087 | |
4088 | /* ... and wait until we've flushed all events. */ | |
d90e17a7 | 4089 | iterate_over_lwps (ptid, kill_wait_callback, NULL); |
f973ed9c DJ |
4090 | } |
4091 | ||
4092 | target_mourn_inferior (); | |
d6b0e80f AC |
4093 | } |
4094 | ||
4095 | static void | |
136d6dae | 4096 | linux_nat_mourn_inferior (struct target_ops *ops) |
d6b0e80f | 4097 | { |
26cb8b7c PA |
4098 | int pid = ptid_get_pid (inferior_ptid); |
4099 | ||
4100 | purge_lwp_list (pid); | |
d6b0e80f | 4101 | |
f973ed9c | 4102 | if (! forks_exist_p ()) |
d90e17a7 PA |
4103 | /* Normal case, no other forks available. */ |
4104 | linux_ops->to_mourn_inferior (ops); | |
f973ed9c DJ |
4105 | else |
4106 | /* Multi-fork case. The current inferior_ptid has exited, but | |
4107 | there are other viable forks to debug. Delete the exiting | |
4108 | one and context-switch to the first available. */ | |
4109 | linux_fork_mourn_inferior (); | |
26cb8b7c PA |
4110 | |
4111 | /* Let the arch-specific native code know this process is gone. */ | |
4112 | linux_nat_forget_process (pid); | |
d6b0e80f AC |
4113 | } |
4114 | ||
5b009018 PA |
4115 | /* Convert a native/host siginfo object, into/from the siginfo in the |
4116 | layout of the inferiors' architecture. */ | |
4117 | ||
4118 | static void | |
a5362b9a | 4119 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
5b009018 PA |
4120 | { |
4121 | int done = 0; | |
4122 | ||
4123 | if (linux_nat_siginfo_fixup != NULL) | |
4124 | done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction); | |
4125 | ||
4126 | /* If there was no callback, or the callback didn't do anything, | |
4127 | then just do a straight memcpy. */ | |
4128 | if (!done) | |
4129 | { | |
4130 | if (direction == 1) | |
a5362b9a | 4131 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
5b009018 | 4132 | else |
a5362b9a | 4133 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
5b009018 PA |
4134 | } |
4135 | } | |
4136 | ||
4aa995e1 PA |
4137 | static LONGEST |
4138 | linux_xfer_siginfo (struct target_ops *ops, enum target_object object, | |
4139 | const char *annex, gdb_byte *readbuf, | |
4140 | const gdb_byte *writebuf, ULONGEST offset, LONGEST len) | |
4141 | { | |
4aa995e1 | 4142 | int pid; |
a5362b9a TS |
4143 | siginfo_t siginfo; |
4144 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; | |
4aa995e1 PA |
4145 | |
4146 | gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO); | |
4147 | gdb_assert (readbuf || writebuf); | |
4148 | ||
4149 | pid = GET_LWP (inferior_ptid); | |
4150 | if (pid == 0) | |
4151 | pid = GET_PID (inferior_ptid); | |
4152 | ||
4153 | if (offset > sizeof (siginfo)) | |
4154 | return -1; | |
4155 | ||
4156 | errno = 0; | |
4157 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
4158 | if (errno != 0) | |
4159 | return -1; | |
4160 | ||
5b009018 PA |
4161 | /* When GDB is built as a 64-bit application, ptrace writes into |
4162 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
4163 | inferior with a 64-bit GDB should look the same as debugging it | |
4164 | with a 32-bit GDB, we need to convert it. GDB core always sees | |
4165 | the converted layout, so any read/write will have to be done | |
4166 | post-conversion. */ | |
4167 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
4168 | ||
4aa995e1 PA |
4169 | if (offset + len > sizeof (siginfo)) |
4170 | len = sizeof (siginfo) - offset; | |
4171 | ||
4172 | if (readbuf != NULL) | |
5b009018 | 4173 | memcpy (readbuf, inf_siginfo + offset, len); |
4aa995e1 PA |
4174 | else |
4175 | { | |
5b009018 PA |
4176 | memcpy (inf_siginfo + offset, writebuf, len); |
4177 | ||
4178 | /* Convert back to ptrace layout before flushing it out. */ | |
4179 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
4180 | ||
4aa995e1 PA |
4181 | errno = 0; |
4182 | ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
4183 | if (errno != 0) | |
4184 | return -1; | |
4185 | } | |
4186 | ||
4187 | return len; | |
4188 | } | |
4189 | ||
10d6c8cd DJ |
4190 | static LONGEST |
4191 | linux_nat_xfer_partial (struct target_ops *ops, enum target_object object, | |
4192 | const char *annex, gdb_byte *readbuf, | |
4193 | const gdb_byte *writebuf, | |
4194 | ULONGEST offset, LONGEST len) | |
d6b0e80f | 4195 | { |
4aa995e1 | 4196 | struct cleanup *old_chain; |
10d6c8cd | 4197 | LONGEST xfer; |
d6b0e80f | 4198 | |
4aa995e1 PA |
4199 | if (object == TARGET_OBJECT_SIGNAL_INFO) |
4200 | return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf, | |
4201 | offset, len); | |
4202 | ||
c35b1492 PA |
4203 | /* The target is connected but no live inferior is selected. Pass |
4204 | this request down to a lower stratum (e.g., the executable | |
4205 | file). */ | |
4206 | if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid)) | |
4207 | return 0; | |
4208 | ||
4aa995e1 PA |
4209 | old_chain = save_inferior_ptid (); |
4210 | ||
d6b0e80f AC |
4211 | if (is_lwp (inferior_ptid)) |
4212 | inferior_ptid = pid_to_ptid (GET_LWP (inferior_ptid)); | |
4213 | ||
10d6c8cd DJ |
4214 | xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf, |
4215 | offset, len); | |
d6b0e80f AC |
4216 | |
4217 | do_cleanups (old_chain); | |
4218 | return xfer; | |
4219 | } | |
4220 | ||
4221 | static int | |
28439f5e | 4222 | linux_thread_alive (ptid_t ptid) |
d6b0e80f | 4223 | { |
8c6a60d1 | 4224 | int err, tmp_errno; |
4c28f408 | 4225 | |
d6b0e80f AC |
4226 | gdb_assert (is_lwp (ptid)); |
4227 | ||
4c28f408 PA |
4228 | /* Send signal 0 instead of anything ptrace, because ptracing a |
4229 | running thread errors out claiming that the thread doesn't | |
4230 | exist. */ | |
4231 | err = kill_lwp (GET_LWP (ptid), 0); | |
8c6a60d1 | 4232 | tmp_errno = errno; |
d6b0e80f AC |
4233 | if (debug_linux_nat) |
4234 | fprintf_unfiltered (gdb_stdlog, | |
4c28f408 | 4235 | "LLTA: KILL(SIG0) %s (%s)\n", |
d6b0e80f | 4236 | target_pid_to_str (ptid), |
8c6a60d1 | 4237 | err ? safe_strerror (tmp_errno) : "OK"); |
9c0dd46b | 4238 | |
4c28f408 | 4239 | if (err != 0) |
d6b0e80f AC |
4240 | return 0; |
4241 | ||
4242 | return 1; | |
4243 | } | |
4244 | ||
28439f5e PA |
4245 | static int |
4246 | linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid) | |
4247 | { | |
4248 | return linux_thread_alive (ptid); | |
4249 | } | |
4250 | ||
d6b0e80f | 4251 | static char * |
117de6a9 | 4252 | linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid) |
d6b0e80f AC |
4253 | { |
4254 | static char buf[64]; | |
4255 | ||
a0ef4274 | 4256 | if (is_lwp (ptid) |
d90e17a7 PA |
4257 | && (GET_PID (ptid) != GET_LWP (ptid) |
4258 | || num_lwps (GET_PID (ptid)) > 1)) | |
d6b0e80f AC |
4259 | { |
4260 | snprintf (buf, sizeof (buf), "LWP %ld", GET_LWP (ptid)); | |
4261 | return buf; | |
4262 | } | |
4263 | ||
4264 | return normal_pid_to_str (ptid); | |
4265 | } | |
4266 | ||
4694da01 TT |
4267 | static char * |
4268 | linux_nat_thread_name (struct thread_info *thr) | |
4269 | { | |
4270 | int pid = ptid_get_pid (thr->ptid); | |
4271 | long lwp = ptid_get_lwp (thr->ptid); | |
4272 | #define FORMAT "/proc/%d/task/%ld/comm" | |
4273 | char buf[sizeof (FORMAT) + 30]; | |
4274 | FILE *comm_file; | |
4275 | char *result = NULL; | |
4276 | ||
4277 | snprintf (buf, sizeof (buf), FORMAT, pid, lwp); | |
4278 | comm_file = fopen (buf, "r"); | |
4279 | if (comm_file) | |
4280 | { | |
4281 | /* Not exported by the kernel, so we define it here. */ | |
4282 | #define COMM_LEN 16 | |
4283 | static char line[COMM_LEN + 1]; | |
4284 | ||
4285 | if (fgets (line, sizeof (line), comm_file)) | |
4286 | { | |
4287 | char *nl = strchr (line, '\n'); | |
4288 | ||
4289 | if (nl) | |
4290 | *nl = '\0'; | |
4291 | if (*line != '\0') | |
4292 | result = line; | |
4293 | } | |
4294 | ||
4295 | fclose (comm_file); | |
4296 | } | |
4297 | ||
4298 | #undef COMM_LEN | |
4299 | #undef FORMAT | |
4300 | ||
4301 | return result; | |
4302 | } | |
4303 | ||
dba24537 AC |
4304 | /* Accepts an integer PID; Returns a string representing a file that |
4305 | can be opened to get the symbols for the child process. */ | |
4306 | ||
6d8fd2b7 UW |
4307 | static char * |
4308 | linux_child_pid_to_exec_file (int pid) | |
dba24537 AC |
4309 | { |
4310 | char *name1, *name2; | |
4311 | ||
4312 | name1 = xmalloc (MAXPATHLEN); | |
4313 | name2 = xmalloc (MAXPATHLEN); | |
4314 | make_cleanup (xfree, name1); | |
4315 | make_cleanup (xfree, name2); | |
4316 | memset (name2, 0, MAXPATHLEN); | |
4317 | ||
4318 | sprintf (name1, "/proc/%d/exe", pid); | |
0270a750 | 4319 | if (readlink (name1, name2, MAXPATHLEN - 1) > 0) |
dba24537 AC |
4320 | return name2; |
4321 | else | |
4322 | return name1; | |
4323 | } | |
4324 | ||
dba24537 AC |
4325 | /* Records the thread's register state for the corefile note |
4326 | section. */ | |
4327 | ||
4328 | static char * | |
6432734d UW |
4329 | linux_nat_collect_thread_registers (const struct regcache *regcache, |
4330 | ptid_t ptid, bfd *obfd, | |
4331 | char *note_data, int *note_size, | |
2ea28649 | 4332 | enum gdb_signal stop_signal) |
dba24537 | 4333 | { |
6432734d | 4334 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
4f844a66 | 4335 | const struct regset *regset; |
55e969c1 | 4336 | int core_regset_p; |
6432734d UW |
4337 | gdb_gregset_t gregs; |
4338 | gdb_fpregset_t fpregs; | |
4f844a66 DM |
4339 | |
4340 | core_regset_p = gdbarch_regset_from_core_section_p (gdbarch); | |
dba24537 | 4341 | |
6432734d UW |
4342 | if (core_regset_p |
4343 | && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg", | |
4344 | sizeof (gregs))) | |
4345 | != NULL && regset->collect_regset != NULL) | |
4346 | regset->collect_regset (regset, regcache, -1, &gregs, sizeof (gregs)); | |
4f844a66 | 4347 | else |
6432734d | 4348 | fill_gregset (regcache, &gregs, -1); |
2f2241f1 | 4349 | |
6432734d UW |
4350 | note_data = (char *) elfcore_write_prstatus |
4351 | (obfd, note_data, note_size, ptid_get_lwp (ptid), | |
2ea28649 | 4352 | gdb_signal_to_host (stop_signal), &gregs); |
2f2241f1 | 4353 | |
6432734d UW |
4354 | if (core_regset_p |
4355 | && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg2", | |
4356 | sizeof (fpregs))) | |
3e43a32a | 4357 | != NULL && regset->collect_regset != NULL) |
6432734d UW |
4358 | regset->collect_regset (regset, regcache, -1, &fpregs, sizeof (fpregs)); |
4359 | else | |
4360 | fill_fpregset (regcache, &fpregs, -1); | |
17ea7499 | 4361 | |
6432734d UW |
4362 | note_data = (char *) elfcore_write_prfpreg (obfd, note_data, note_size, |
4363 | &fpregs, sizeof (fpregs)); | |
4f844a66 | 4364 | |
dba24537 AC |
4365 | return note_data; |
4366 | } | |
4367 | ||
dba24537 AC |
4368 | /* Fills the "to_make_corefile_note" target vector. Builds the note |
4369 | section for a corefile, and returns it in a malloc buffer. */ | |
4370 | ||
4371 | static char * | |
4372 | linux_nat_make_corefile_notes (bfd *obfd, int *note_size) | |
4373 | { | |
6432734d UW |
4374 | /* FIXME: uweigand/2011-10-06: Once all GNU/Linux architectures have been |
4375 | converted to gdbarch_core_regset_sections, this function can go away. */ | |
f5656ead | 4376 | return linux_make_corefile_notes (target_gdbarch (), obfd, note_size, |
6432734d | 4377 | linux_nat_collect_thread_registers); |
dba24537 AC |
4378 | } |
4379 | ||
10d6c8cd DJ |
4380 | /* Implement the to_xfer_partial interface for memory reads using the /proc |
4381 | filesystem. Because we can use a single read() call for /proc, this | |
4382 | can be much more efficient than banging away at PTRACE_PEEKTEXT, | |
4383 | but it doesn't support writes. */ | |
4384 | ||
4385 | static LONGEST | |
4386 | linux_proc_xfer_partial (struct target_ops *ops, enum target_object object, | |
4387 | const char *annex, gdb_byte *readbuf, | |
4388 | const gdb_byte *writebuf, | |
4389 | ULONGEST offset, LONGEST len) | |
dba24537 | 4390 | { |
10d6c8cd DJ |
4391 | LONGEST ret; |
4392 | int fd; | |
dba24537 AC |
4393 | char filename[64]; |
4394 | ||
10d6c8cd | 4395 | if (object != TARGET_OBJECT_MEMORY || !readbuf) |
dba24537 AC |
4396 | return 0; |
4397 | ||
4398 | /* Don't bother for one word. */ | |
4399 | if (len < 3 * sizeof (long)) | |
4400 | return 0; | |
4401 | ||
4402 | /* We could keep this file open and cache it - possibly one per | |
4403 | thread. That requires some juggling, but is even faster. */ | |
4404 | sprintf (filename, "/proc/%d/mem", PIDGET (inferior_ptid)); | |
4405 | fd = open (filename, O_RDONLY | O_LARGEFILE); | |
4406 | if (fd == -1) | |
4407 | return 0; | |
4408 | ||
4409 | /* If pread64 is available, use it. It's faster if the kernel | |
4410 | supports it (only one syscall), and it's 64-bit safe even on | |
4411 | 32-bit platforms (for instance, SPARC debugging a SPARC64 | |
4412 | application). */ | |
4413 | #ifdef HAVE_PREAD64 | |
10d6c8cd | 4414 | if (pread64 (fd, readbuf, len, offset) != len) |
dba24537 | 4415 | #else |
10d6c8cd | 4416 | if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len) |
dba24537 AC |
4417 | #endif |
4418 | ret = 0; | |
4419 | else | |
4420 | ret = len; | |
4421 | ||
4422 | close (fd); | |
4423 | return ret; | |
4424 | } | |
4425 | ||
efcbbd14 UW |
4426 | |
4427 | /* Enumerate spufs IDs for process PID. */ | |
4428 | static LONGEST | |
4429 | spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, LONGEST len) | |
4430 | { | |
f5656ead | 4431 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
efcbbd14 UW |
4432 | LONGEST pos = 0; |
4433 | LONGEST written = 0; | |
4434 | char path[128]; | |
4435 | DIR *dir; | |
4436 | struct dirent *entry; | |
4437 | ||
4438 | xsnprintf (path, sizeof path, "/proc/%d/fd", pid); | |
4439 | dir = opendir (path); | |
4440 | if (!dir) | |
4441 | return -1; | |
4442 | ||
4443 | rewinddir (dir); | |
4444 | while ((entry = readdir (dir)) != NULL) | |
4445 | { | |
4446 | struct stat st; | |
4447 | struct statfs stfs; | |
4448 | int fd; | |
4449 | ||
4450 | fd = atoi (entry->d_name); | |
4451 | if (!fd) | |
4452 | continue; | |
4453 | ||
4454 | xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd); | |
4455 | if (stat (path, &st) != 0) | |
4456 | continue; | |
4457 | if (!S_ISDIR (st.st_mode)) | |
4458 | continue; | |
4459 | ||
4460 | if (statfs (path, &stfs) != 0) | |
4461 | continue; | |
4462 | if (stfs.f_type != SPUFS_MAGIC) | |
4463 | continue; | |
4464 | ||
4465 | if (pos >= offset && pos + 4 <= offset + len) | |
4466 | { | |
4467 | store_unsigned_integer (buf + pos - offset, 4, byte_order, fd); | |
4468 | written += 4; | |
4469 | } | |
4470 | pos += 4; | |
4471 | } | |
4472 | ||
4473 | closedir (dir); | |
4474 | return written; | |
4475 | } | |
4476 | ||
4477 | /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU | |
4478 | object type, using the /proc file system. */ | |
4479 | static LONGEST | |
4480 | linux_proc_xfer_spu (struct target_ops *ops, enum target_object object, | |
4481 | const char *annex, gdb_byte *readbuf, | |
4482 | const gdb_byte *writebuf, | |
4483 | ULONGEST offset, LONGEST len) | |
4484 | { | |
4485 | char buf[128]; | |
4486 | int fd = 0; | |
4487 | int ret = -1; | |
4488 | int pid = PIDGET (inferior_ptid); | |
4489 | ||
4490 | if (!annex) | |
4491 | { | |
4492 | if (!readbuf) | |
4493 | return -1; | |
4494 | else | |
4495 | return spu_enumerate_spu_ids (pid, readbuf, offset, len); | |
4496 | } | |
4497 | ||
4498 | xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex); | |
4499 | fd = open (buf, writebuf? O_WRONLY : O_RDONLY); | |
4500 | if (fd <= 0) | |
4501 | return -1; | |
4502 | ||
4503 | if (offset != 0 | |
4504 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) | |
4505 | { | |
4506 | close (fd); | |
4507 | return 0; | |
4508 | } | |
4509 | ||
4510 | if (writebuf) | |
4511 | ret = write (fd, writebuf, (size_t) len); | |
4512 | else if (readbuf) | |
4513 | ret = read (fd, readbuf, (size_t) len); | |
4514 | ||
4515 | close (fd); | |
4516 | return ret; | |
4517 | } | |
4518 | ||
4519 | ||
dba24537 AC |
4520 | /* Parse LINE as a signal set and add its set bits to SIGS. */ |
4521 | ||
4522 | static void | |
4523 | add_line_to_sigset (const char *line, sigset_t *sigs) | |
4524 | { | |
4525 | int len = strlen (line) - 1; | |
4526 | const char *p; | |
4527 | int signum; | |
4528 | ||
4529 | if (line[len] != '\n') | |
8a3fe4f8 | 4530 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4531 | |
4532 | p = line; | |
4533 | signum = len * 4; | |
4534 | while (len-- > 0) | |
4535 | { | |
4536 | int digit; | |
4537 | ||
4538 | if (*p >= '0' && *p <= '9') | |
4539 | digit = *p - '0'; | |
4540 | else if (*p >= 'a' && *p <= 'f') | |
4541 | digit = *p - 'a' + 10; | |
4542 | else | |
8a3fe4f8 | 4543 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4544 | |
4545 | signum -= 4; | |
4546 | ||
4547 | if (digit & 1) | |
4548 | sigaddset (sigs, signum + 1); | |
4549 | if (digit & 2) | |
4550 | sigaddset (sigs, signum + 2); | |
4551 | if (digit & 4) | |
4552 | sigaddset (sigs, signum + 3); | |
4553 | if (digit & 8) | |
4554 | sigaddset (sigs, signum + 4); | |
4555 | ||
4556 | p++; | |
4557 | } | |
4558 | } | |
4559 | ||
4560 | /* Find process PID's pending signals from /proc/pid/status and set | |
4561 | SIGS to match. */ | |
4562 | ||
4563 | void | |
3e43a32a MS |
4564 | linux_proc_pending_signals (int pid, sigset_t *pending, |
4565 | sigset_t *blocked, sigset_t *ignored) | |
dba24537 AC |
4566 | { |
4567 | FILE *procfile; | |
4568 | char buffer[MAXPATHLEN], fname[MAXPATHLEN]; | |
7c8a8b04 | 4569 | struct cleanup *cleanup; |
dba24537 AC |
4570 | |
4571 | sigemptyset (pending); | |
4572 | sigemptyset (blocked); | |
4573 | sigemptyset (ignored); | |
4574 | sprintf (fname, "/proc/%d/status", pid); | |
4575 | procfile = fopen (fname, "r"); | |
4576 | if (procfile == NULL) | |
8a3fe4f8 | 4577 | error (_("Could not open %s"), fname); |
7c8a8b04 | 4578 | cleanup = make_cleanup_fclose (procfile); |
dba24537 AC |
4579 | |
4580 | while (fgets (buffer, MAXPATHLEN, procfile) != NULL) | |
4581 | { | |
4582 | /* Normal queued signals are on the SigPnd line in the status | |
4583 | file. However, 2.6 kernels also have a "shared" pending | |
4584 | queue for delivering signals to a thread group, so check for | |
4585 | a ShdPnd line also. | |
4586 | ||
4587 | Unfortunately some Red Hat kernels include the shared pending | |
4588 | queue but not the ShdPnd status field. */ | |
4589 | ||
4590 | if (strncmp (buffer, "SigPnd:\t", 8) == 0) | |
4591 | add_line_to_sigset (buffer + 8, pending); | |
4592 | else if (strncmp (buffer, "ShdPnd:\t", 8) == 0) | |
4593 | add_line_to_sigset (buffer + 8, pending); | |
4594 | else if (strncmp (buffer, "SigBlk:\t", 8) == 0) | |
4595 | add_line_to_sigset (buffer + 8, blocked); | |
4596 | else if (strncmp (buffer, "SigIgn:\t", 8) == 0) | |
4597 | add_line_to_sigset (buffer + 8, ignored); | |
4598 | } | |
4599 | ||
7c8a8b04 | 4600 | do_cleanups (cleanup); |
dba24537 AC |
4601 | } |
4602 | ||
07e059b5 VP |
4603 | static LONGEST |
4604 | linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object, | |
e0881a8e MS |
4605 | const char *annex, gdb_byte *readbuf, |
4606 | const gdb_byte *writebuf, ULONGEST offset, LONGEST len) | |
07e059b5 | 4607 | { |
07e059b5 VP |
4608 | gdb_assert (object == TARGET_OBJECT_OSDATA); |
4609 | ||
d26e3629 | 4610 | return linux_common_xfer_osdata (annex, readbuf, offset, len); |
07e059b5 VP |
4611 | } |
4612 | ||
10d6c8cd DJ |
4613 | static LONGEST |
4614 | linux_xfer_partial (struct target_ops *ops, enum target_object object, | |
4615 | const char *annex, gdb_byte *readbuf, | |
4616 | const gdb_byte *writebuf, ULONGEST offset, LONGEST len) | |
4617 | { | |
4618 | LONGEST xfer; | |
4619 | ||
4620 | if (object == TARGET_OBJECT_AUXV) | |
9f2982ff | 4621 | return memory_xfer_auxv (ops, object, annex, readbuf, writebuf, |
10d6c8cd DJ |
4622 | offset, len); |
4623 | ||
07e059b5 VP |
4624 | if (object == TARGET_OBJECT_OSDATA) |
4625 | return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf, | |
4626 | offset, len); | |
4627 | ||
efcbbd14 UW |
4628 | if (object == TARGET_OBJECT_SPU) |
4629 | return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf, | |
4630 | offset, len); | |
4631 | ||
8f313923 JK |
4632 | /* GDB calculates all the addresses in possibly larget width of the address. |
4633 | Address width needs to be masked before its final use - either by | |
4634 | linux_proc_xfer_partial or inf_ptrace_xfer_partial. | |
4635 | ||
4636 | Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ | |
4637 | ||
4638 | if (object == TARGET_OBJECT_MEMORY) | |
4639 | { | |
f5656ead | 4640 | int addr_bit = gdbarch_addr_bit (target_gdbarch ()); |
8f313923 JK |
4641 | |
4642 | if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) | |
4643 | offset &= ((ULONGEST) 1 << addr_bit) - 1; | |
4644 | } | |
4645 | ||
10d6c8cd DJ |
4646 | xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf, |
4647 | offset, len); | |
4648 | if (xfer != 0) | |
4649 | return xfer; | |
4650 | ||
4651 | return super_xfer_partial (ops, object, annex, readbuf, writebuf, | |
4652 | offset, len); | |
4653 | } | |
4654 | ||
5808517f YQ |
4655 | static void |
4656 | cleanup_target_stop (void *arg) | |
4657 | { | |
4658 | ptid_t *ptid = (ptid_t *) arg; | |
4659 | ||
4660 | gdb_assert (arg != NULL); | |
4661 | ||
4662 | /* Unpause all */ | |
a493e3e2 | 4663 | target_resume (*ptid, 0, GDB_SIGNAL_0); |
5808517f YQ |
4664 | } |
4665 | ||
4666 | static VEC(static_tracepoint_marker_p) * | |
4667 | linux_child_static_tracepoint_markers_by_strid (const char *strid) | |
4668 | { | |
4669 | char s[IPA_CMD_BUF_SIZE]; | |
4670 | struct cleanup *old_chain; | |
4671 | int pid = ptid_get_pid (inferior_ptid); | |
4672 | VEC(static_tracepoint_marker_p) *markers = NULL; | |
4673 | struct static_tracepoint_marker *marker = NULL; | |
4674 | char *p = s; | |
4675 | ptid_t ptid = ptid_build (pid, 0, 0); | |
4676 | ||
4677 | /* Pause all */ | |
4678 | target_stop (ptid); | |
4679 | ||
4680 | memcpy (s, "qTfSTM", sizeof ("qTfSTM")); | |
4681 | s[sizeof ("qTfSTM")] = 0; | |
4682 | ||
42476b70 | 4683 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4684 | |
4685 | old_chain = make_cleanup (free_current_marker, &marker); | |
4686 | make_cleanup (cleanup_target_stop, &ptid); | |
4687 | ||
4688 | while (*p++ == 'm') | |
4689 | { | |
4690 | if (marker == NULL) | |
4691 | marker = XCNEW (struct static_tracepoint_marker); | |
4692 | ||
4693 | do | |
4694 | { | |
4695 | parse_static_tracepoint_marker_definition (p, &p, marker); | |
4696 | ||
4697 | if (strid == NULL || strcmp (strid, marker->str_id) == 0) | |
4698 | { | |
4699 | VEC_safe_push (static_tracepoint_marker_p, | |
4700 | markers, marker); | |
4701 | marker = NULL; | |
4702 | } | |
4703 | else | |
4704 | { | |
4705 | release_static_tracepoint_marker (marker); | |
4706 | memset (marker, 0, sizeof (*marker)); | |
4707 | } | |
4708 | } | |
4709 | while (*p++ == ','); /* comma-separated list */ | |
4710 | ||
4711 | memcpy (s, "qTsSTM", sizeof ("qTsSTM")); | |
4712 | s[sizeof ("qTsSTM")] = 0; | |
42476b70 | 4713 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4714 | p = s; |
4715 | } | |
4716 | ||
4717 | do_cleanups (old_chain); | |
4718 | ||
4719 | return markers; | |
4720 | } | |
4721 | ||
e9efe249 | 4722 | /* Create a prototype generic GNU/Linux target. The client can override |
10d6c8cd DJ |
4723 | it with local methods. */ |
4724 | ||
910122bf UW |
4725 | static void |
4726 | linux_target_install_ops (struct target_ops *t) | |
10d6c8cd | 4727 | { |
6d8fd2b7 | 4728 | t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint; |
eb73ad13 | 4729 | t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint; |
6d8fd2b7 | 4730 | t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint; |
eb73ad13 | 4731 | t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint; |
6d8fd2b7 | 4732 | t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint; |
eb73ad13 | 4733 | t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint; |
a96d9b2e | 4734 | t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint; |
6d8fd2b7 | 4735 | t->to_pid_to_exec_file = linux_child_pid_to_exec_file; |
10d6c8cd | 4736 | t->to_post_startup_inferior = linux_child_post_startup_inferior; |
6d8fd2b7 UW |
4737 | t->to_post_attach = linux_child_post_attach; |
4738 | t->to_follow_fork = linux_child_follow_fork; | |
10d6c8cd DJ |
4739 | t->to_make_corefile_notes = linux_nat_make_corefile_notes; |
4740 | ||
4741 | super_xfer_partial = t->to_xfer_partial; | |
4742 | t->to_xfer_partial = linux_xfer_partial; | |
5808517f YQ |
4743 | |
4744 | t->to_static_tracepoint_markers_by_strid | |
4745 | = linux_child_static_tracepoint_markers_by_strid; | |
910122bf UW |
4746 | } |
4747 | ||
4748 | struct target_ops * | |
4749 | linux_target (void) | |
4750 | { | |
4751 | struct target_ops *t; | |
4752 | ||
4753 | t = inf_ptrace_target (); | |
4754 | linux_target_install_ops (t); | |
4755 | ||
4756 | return t; | |
4757 | } | |
4758 | ||
4759 | struct target_ops * | |
7714d83a | 4760 | linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int)) |
910122bf UW |
4761 | { |
4762 | struct target_ops *t; | |
4763 | ||
4764 | t = inf_ptrace_trad_target (register_u_offset); | |
4765 | linux_target_install_ops (t); | |
10d6c8cd | 4766 | |
10d6c8cd DJ |
4767 | return t; |
4768 | } | |
4769 | ||
b84876c2 PA |
4770 | /* target_is_async_p implementation. */ |
4771 | ||
4772 | static int | |
4773 | linux_nat_is_async_p (void) | |
4774 | { | |
4775 | /* NOTE: palves 2008-03-21: We're only async when the user requests | |
7feb7d06 | 4776 | it explicitly with the "set target-async" command. |
b84876c2 | 4777 | Someday, linux will always be async. */ |
3dd5b83d | 4778 | return target_async_permitted; |
b84876c2 PA |
4779 | } |
4780 | ||
4781 | /* target_can_async_p implementation. */ | |
4782 | ||
4783 | static int | |
4784 | linux_nat_can_async_p (void) | |
4785 | { | |
4786 | /* NOTE: palves 2008-03-21: We're only async when the user requests | |
7feb7d06 | 4787 | it explicitly with the "set target-async" command. |
b84876c2 | 4788 | Someday, linux will always be async. */ |
3dd5b83d | 4789 | return target_async_permitted; |
b84876c2 PA |
4790 | } |
4791 | ||
9908b566 VP |
4792 | static int |
4793 | linux_nat_supports_non_stop (void) | |
4794 | { | |
4795 | return 1; | |
4796 | } | |
4797 | ||
d90e17a7 PA |
4798 | /* True if we want to support multi-process. To be removed when GDB |
4799 | supports multi-exec. */ | |
4800 | ||
2277426b | 4801 | int linux_multi_process = 1; |
d90e17a7 PA |
4802 | |
4803 | static int | |
4804 | linux_nat_supports_multi_process (void) | |
4805 | { | |
4806 | return linux_multi_process; | |
4807 | } | |
4808 | ||
03583c20 UW |
4809 | static int |
4810 | linux_nat_supports_disable_randomization (void) | |
4811 | { | |
4812 | #ifdef HAVE_PERSONALITY | |
4813 | return 1; | |
4814 | #else | |
4815 | return 0; | |
4816 | #endif | |
4817 | } | |
4818 | ||
b84876c2 PA |
4819 | static int async_terminal_is_ours = 1; |
4820 | ||
4821 | /* target_terminal_inferior implementation. */ | |
4822 | ||
4823 | static void | |
4824 | linux_nat_terminal_inferior (void) | |
4825 | { | |
4826 | if (!target_is_async_p ()) | |
4827 | { | |
4828 | /* Async mode is disabled. */ | |
4829 | terminal_inferior (); | |
4830 | return; | |
4831 | } | |
4832 | ||
b84876c2 PA |
4833 | terminal_inferior (); |
4834 | ||
d9d2d8b6 | 4835 | /* Calls to target_terminal_*() are meant to be idempotent. */ |
b84876c2 PA |
4836 | if (!async_terminal_is_ours) |
4837 | return; | |
4838 | ||
4839 | delete_file_handler (input_fd); | |
4840 | async_terminal_is_ours = 0; | |
4841 | set_sigint_trap (); | |
4842 | } | |
4843 | ||
4844 | /* target_terminal_ours implementation. */ | |
4845 | ||
2c0b251b | 4846 | static void |
b84876c2 PA |
4847 | linux_nat_terminal_ours (void) |
4848 | { | |
4849 | if (!target_is_async_p ()) | |
4850 | { | |
4851 | /* Async mode is disabled. */ | |
4852 | terminal_ours (); | |
4853 | return; | |
4854 | } | |
4855 | ||
4856 | /* GDB should never give the terminal to the inferior if the | |
4857 | inferior is running in the background (run&, continue&, etc.), | |
4858 | but claiming it sure should. */ | |
4859 | terminal_ours (); | |
4860 | ||
b84876c2 PA |
4861 | if (async_terminal_is_ours) |
4862 | return; | |
4863 | ||
4864 | clear_sigint_trap (); | |
4865 | add_file_handler (input_fd, stdin_event_handler, 0); | |
4866 | async_terminal_is_ours = 1; | |
4867 | } | |
4868 | ||
4869 | static void (*async_client_callback) (enum inferior_event_type event_type, | |
4870 | void *context); | |
4871 | static void *async_client_context; | |
4872 | ||
7feb7d06 PA |
4873 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
4874 | so we notice when any child changes state, and notify the | |
4875 | event-loop; it allows us to use sigsuspend in linux_nat_wait_1 | |
4876 | above to wait for the arrival of a SIGCHLD. */ | |
4877 | ||
b84876c2 | 4878 | static void |
7feb7d06 | 4879 | sigchld_handler (int signo) |
b84876c2 | 4880 | { |
7feb7d06 PA |
4881 | int old_errno = errno; |
4882 | ||
01124a23 DE |
4883 | if (debug_linux_nat) |
4884 | ui_file_write_async_safe (gdb_stdlog, | |
4885 | "sigchld\n", sizeof ("sigchld\n") - 1); | |
7feb7d06 PA |
4886 | |
4887 | if (signo == SIGCHLD | |
4888 | && linux_nat_event_pipe[0] != -1) | |
4889 | async_file_mark (); /* Let the event loop know that there are | |
4890 | events to handle. */ | |
4891 | ||
4892 | errno = old_errno; | |
4893 | } | |
4894 | ||
4895 | /* Callback registered with the target events file descriptor. */ | |
4896 | ||
4897 | static void | |
4898 | handle_target_event (int error, gdb_client_data client_data) | |
4899 | { | |
4900 | (*async_client_callback) (INF_REG_EVENT, async_client_context); | |
4901 | } | |
4902 | ||
4903 | /* Create/destroy the target events pipe. Returns previous state. */ | |
4904 | ||
4905 | static int | |
4906 | linux_async_pipe (int enable) | |
4907 | { | |
4908 | int previous = (linux_nat_event_pipe[0] != -1); | |
4909 | ||
4910 | if (previous != enable) | |
4911 | { | |
4912 | sigset_t prev_mask; | |
4913 | ||
4914 | block_child_signals (&prev_mask); | |
4915 | ||
4916 | if (enable) | |
4917 | { | |
4918 | if (pipe (linux_nat_event_pipe) == -1) | |
4919 | internal_error (__FILE__, __LINE__, | |
4920 | "creating event pipe failed."); | |
4921 | ||
4922 | fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK); | |
4923 | fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK); | |
4924 | } | |
4925 | else | |
4926 | { | |
4927 | close (linux_nat_event_pipe[0]); | |
4928 | close (linux_nat_event_pipe[1]); | |
4929 | linux_nat_event_pipe[0] = -1; | |
4930 | linux_nat_event_pipe[1] = -1; | |
4931 | } | |
4932 | ||
4933 | restore_child_signals_mask (&prev_mask); | |
4934 | } | |
4935 | ||
4936 | return previous; | |
b84876c2 PA |
4937 | } |
4938 | ||
4939 | /* target_async implementation. */ | |
4940 | ||
4941 | static void | |
4942 | linux_nat_async (void (*callback) (enum inferior_event_type event_type, | |
4943 | void *context), void *context) | |
4944 | { | |
b84876c2 PA |
4945 | if (callback != NULL) |
4946 | { | |
4947 | async_client_callback = callback; | |
4948 | async_client_context = context; | |
7feb7d06 PA |
4949 | if (!linux_async_pipe (1)) |
4950 | { | |
4951 | add_file_handler (linux_nat_event_pipe[0], | |
4952 | handle_target_event, NULL); | |
4953 | /* There may be pending events to handle. Tell the event loop | |
4954 | to poll them. */ | |
4955 | async_file_mark (); | |
4956 | } | |
b84876c2 PA |
4957 | } |
4958 | else | |
4959 | { | |
4960 | async_client_callback = callback; | |
4961 | async_client_context = context; | |
b84876c2 | 4962 | delete_file_handler (linux_nat_event_pipe[0]); |
7feb7d06 | 4963 | linux_async_pipe (0); |
b84876c2 PA |
4964 | } |
4965 | return; | |
4966 | } | |
4967 | ||
a493e3e2 | 4968 | /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other |
252fbfc8 PA |
4969 | event came out. */ |
4970 | ||
4c28f408 | 4971 | static int |
252fbfc8 | 4972 | linux_nat_stop_lwp (struct lwp_info *lwp, void *data) |
4c28f408 | 4973 | { |
d90e17a7 | 4974 | if (!lwp->stopped) |
252fbfc8 | 4975 | { |
d90e17a7 PA |
4976 | if (debug_linux_nat) |
4977 | fprintf_unfiltered (gdb_stdlog, | |
4978 | "LNSL: running -> suspending %s\n", | |
4979 | target_pid_to_str (lwp->ptid)); | |
252fbfc8 | 4980 | |
252fbfc8 | 4981 | |
25289eb2 PA |
4982 | if (lwp->last_resume_kind == resume_stop) |
4983 | { | |
4984 | if (debug_linux_nat) | |
4985 | fprintf_unfiltered (gdb_stdlog, | |
4986 | "linux-nat: already stopping LWP %ld at " | |
4987 | "GDB's request\n", | |
4988 | ptid_get_lwp (lwp->ptid)); | |
4989 | return 0; | |
4990 | } | |
252fbfc8 | 4991 | |
25289eb2 PA |
4992 | stop_callback (lwp, NULL); |
4993 | lwp->last_resume_kind = resume_stop; | |
d90e17a7 PA |
4994 | } |
4995 | else | |
4996 | { | |
4997 | /* Already known to be stopped; do nothing. */ | |
252fbfc8 | 4998 | |
d90e17a7 PA |
4999 | if (debug_linux_nat) |
5000 | { | |
e09875d4 | 5001 | if (find_thread_ptid (lwp->ptid)->stop_requested) |
3e43a32a MS |
5002 | fprintf_unfiltered (gdb_stdlog, |
5003 | "LNSL: already stopped/stop_requested %s\n", | |
d90e17a7 PA |
5004 | target_pid_to_str (lwp->ptid)); |
5005 | else | |
3e43a32a MS |
5006 | fprintf_unfiltered (gdb_stdlog, |
5007 | "LNSL: already stopped/no " | |
5008 | "stop_requested yet %s\n", | |
d90e17a7 | 5009 | target_pid_to_str (lwp->ptid)); |
252fbfc8 PA |
5010 | } |
5011 | } | |
4c28f408 PA |
5012 | return 0; |
5013 | } | |
5014 | ||
5015 | static void | |
5016 | linux_nat_stop (ptid_t ptid) | |
5017 | { | |
5018 | if (non_stop) | |
d90e17a7 | 5019 | iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL); |
4c28f408 PA |
5020 | else |
5021 | linux_ops->to_stop (ptid); | |
5022 | } | |
5023 | ||
d90e17a7 PA |
5024 | static void |
5025 | linux_nat_close (int quitting) | |
5026 | { | |
5027 | /* Unregister from the event loop. */ | |
305436e0 PA |
5028 | if (linux_nat_is_async_p ()) |
5029 | linux_nat_async (NULL, 0); | |
d90e17a7 | 5030 | |
d90e17a7 PA |
5031 | if (linux_ops->to_close) |
5032 | linux_ops->to_close (quitting); | |
5033 | } | |
5034 | ||
c0694254 PA |
5035 | /* When requests are passed down from the linux-nat layer to the |
5036 | single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are | |
5037 | used. The address space pointer is stored in the inferior object, | |
5038 | but the common code that is passed such ptid can't tell whether | |
5039 | lwpid is a "main" process id or not (it assumes so). We reverse | |
5040 | look up the "main" process id from the lwp here. */ | |
5041 | ||
70221824 | 5042 | static struct address_space * |
c0694254 PA |
5043 | linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid) |
5044 | { | |
5045 | struct lwp_info *lwp; | |
5046 | struct inferior *inf; | |
5047 | int pid; | |
5048 | ||
5049 | pid = GET_LWP (ptid); | |
5050 | if (GET_LWP (ptid) == 0) | |
5051 | { | |
5052 | /* An (lwpid,0,0) ptid. Look up the lwp object to get at the | |
5053 | tgid. */ | |
5054 | lwp = find_lwp_pid (ptid); | |
5055 | pid = GET_PID (lwp->ptid); | |
5056 | } | |
5057 | else | |
5058 | { | |
5059 | /* A (pid,lwpid,0) ptid. */ | |
5060 | pid = GET_PID (ptid); | |
5061 | } | |
5062 | ||
5063 | inf = find_inferior_pid (pid); | |
5064 | gdb_assert (inf != NULL); | |
5065 | return inf->aspace; | |
5066 | } | |
5067 | ||
dc146f7c VP |
5068 | /* Return the cached value of the processor core for thread PTID. */ |
5069 | ||
70221824 | 5070 | static int |
dc146f7c VP |
5071 | linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid) |
5072 | { | |
5073 | struct lwp_info *info = find_lwp_pid (ptid); | |
e0881a8e | 5074 | |
dc146f7c VP |
5075 | if (info) |
5076 | return info->core; | |
5077 | return -1; | |
5078 | } | |
5079 | ||
f973ed9c DJ |
5080 | void |
5081 | linux_nat_add_target (struct target_ops *t) | |
5082 | { | |
f973ed9c DJ |
5083 | /* Save the provided single-threaded target. We save this in a separate |
5084 | variable because another target we've inherited from (e.g. inf-ptrace) | |
5085 | may have saved a pointer to T; we want to use it for the final | |
5086 | process stratum target. */ | |
5087 | linux_ops_saved = *t; | |
5088 | linux_ops = &linux_ops_saved; | |
5089 | ||
5090 | /* Override some methods for multithreading. */ | |
b84876c2 | 5091 | t->to_create_inferior = linux_nat_create_inferior; |
f973ed9c DJ |
5092 | t->to_attach = linux_nat_attach; |
5093 | t->to_detach = linux_nat_detach; | |
5094 | t->to_resume = linux_nat_resume; | |
5095 | t->to_wait = linux_nat_wait; | |
2455069d | 5096 | t->to_pass_signals = linux_nat_pass_signals; |
f973ed9c DJ |
5097 | t->to_xfer_partial = linux_nat_xfer_partial; |
5098 | t->to_kill = linux_nat_kill; | |
5099 | t->to_mourn_inferior = linux_nat_mourn_inferior; | |
5100 | t->to_thread_alive = linux_nat_thread_alive; | |
5101 | t->to_pid_to_str = linux_nat_pid_to_str; | |
4694da01 | 5102 | t->to_thread_name = linux_nat_thread_name; |
f973ed9c | 5103 | t->to_has_thread_control = tc_schedlock; |
c0694254 | 5104 | t->to_thread_address_space = linux_nat_thread_address_space; |
ebec9a0f PA |
5105 | t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint; |
5106 | t->to_stopped_data_address = linux_nat_stopped_data_address; | |
f973ed9c | 5107 | |
b84876c2 PA |
5108 | t->to_can_async_p = linux_nat_can_async_p; |
5109 | t->to_is_async_p = linux_nat_is_async_p; | |
9908b566 | 5110 | t->to_supports_non_stop = linux_nat_supports_non_stop; |
b84876c2 | 5111 | t->to_async = linux_nat_async; |
b84876c2 PA |
5112 | t->to_terminal_inferior = linux_nat_terminal_inferior; |
5113 | t->to_terminal_ours = linux_nat_terminal_ours; | |
d90e17a7 | 5114 | t->to_close = linux_nat_close; |
b84876c2 | 5115 | |
4c28f408 PA |
5116 | /* Methods for non-stop support. */ |
5117 | t->to_stop = linux_nat_stop; | |
5118 | ||
d90e17a7 PA |
5119 | t->to_supports_multi_process = linux_nat_supports_multi_process; |
5120 | ||
03583c20 UW |
5121 | t->to_supports_disable_randomization |
5122 | = linux_nat_supports_disable_randomization; | |
5123 | ||
dc146f7c VP |
5124 | t->to_core_of_thread = linux_nat_core_of_thread; |
5125 | ||
f973ed9c DJ |
5126 | /* We don't change the stratum; this target will sit at |
5127 | process_stratum and thread_db will set at thread_stratum. This | |
5128 | is a little strange, since this is a multi-threaded-capable | |
5129 | target, but we want to be on the stack below thread_db, and we | |
5130 | also want to be used for single-threaded processes. */ | |
5131 | ||
5132 | add_target (t); | |
f973ed9c DJ |
5133 | } |
5134 | ||
9f0bdab8 DJ |
5135 | /* Register a method to call whenever a new thread is attached. */ |
5136 | void | |
7b50312a PA |
5137 | linux_nat_set_new_thread (struct target_ops *t, |
5138 | void (*new_thread) (struct lwp_info *)) | |
9f0bdab8 DJ |
5139 | { |
5140 | /* Save the pointer. We only support a single registered instance | |
5141 | of the GNU/Linux native target, so we do not need to map this to | |
5142 | T. */ | |
5143 | linux_nat_new_thread = new_thread; | |
5144 | } | |
5145 | ||
26cb8b7c PA |
5146 | /* See declaration in linux-nat.h. */ |
5147 | ||
5148 | void | |
5149 | linux_nat_set_new_fork (struct target_ops *t, | |
5150 | linux_nat_new_fork_ftype *new_fork) | |
5151 | { | |
5152 | /* Save the pointer. */ | |
5153 | linux_nat_new_fork = new_fork; | |
5154 | } | |
5155 | ||
5156 | /* See declaration in linux-nat.h. */ | |
5157 | ||
5158 | void | |
5159 | linux_nat_set_forget_process (struct target_ops *t, | |
5160 | linux_nat_forget_process_ftype *fn) | |
5161 | { | |
5162 | /* Save the pointer. */ | |
5163 | linux_nat_forget_process_hook = fn; | |
5164 | } | |
5165 | ||
5166 | /* See declaration in linux-nat.h. */ | |
5167 | ||
5168 | void | |
5169 | linux_nat_forget_process (pid_t pid) | |
5170 | { | |
5171 | if (linux_nat_forget_process_hook != NULL) | |
5172 | linux_nat_forget_process_hook (pid); | |
5173 | } | |
5174 | ||
5b009018 PA |
5175 | /* Register a method that converts a siginfo object between the layout |
5176 | that ptrace returns, and the layout in the architecture of the | |
5177 | inferior. */ | |
5178 | void | |
5179 | linux_nat_set_siginfo_fixup (struct target_ops *t, | |
a5362b9a | 5180 | int (*siginfo_fixup) (siginfo_t *, |
5b009018 PA |
5181 | gdb_byte *, |
5182 | int)) | |
5183 | { | |
5184 | /* Save the pointer. */ | |
5185 | linux_nat_siginfo_fixup = siginfo_fixup; | |
5186 | } | |
5187 | ||
7b50312a PA |
5188 | /* Register a method to call prior to resuming a thread. */ |
5189 | ||
5190 | void | |
5191 | linux_nat_set_prepare_to_resume (struct target_ops *t, | |
5192 | void (*prepare_to_resume) (struct lwp_info *)) | |
5193 | { | |
5194 | /* Save the pointer. */ | |
5195 | linux_nat_prepare_to_resume = prepare_to_resume; | |
5196 | } | |
5197 | ||
f865ee35 JK |
5198 | /* See linux-nat.h. */ |
5199 | ||
5200 | int | |
5201 | linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo) | |
9f0bdab8 | 5202 | { |
da559b09 | 5203 | int pid; |
9f0bdab8 | 5204 | |
da559b09 JK |
5205 | pid = GET_LWP (ptid); |
5206 | if (pid == 0) | |
5207 | pid = GET_PID (ptid); | |
f865ee35 | 5208 | |
da559b09 JK |
5209 | errno = 0; |
5210 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo); | |
5211 | if (errno != 0) | |
5212 | { | |
5213 | memset (siginfo, 0, sizeof (*siginfo)); | |
5214 | return 0; | |
5215 | } | |
f865ee35 | 5216 | return 1; |
9f0bdab8 DJ |
5217 | } |
5218 | ||
2c0b251b PA |
5219 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
5220 | extern initialize_file_ftype _initialize_linux_nat; | |
5221 | ||
d6b0e80f AC |
5222 | void |
5223 | _initialize_linux_nat (void) | |
5224 | { | |
ccce17b0 YQ |
5225 | add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance, |
5226 | &debug_linux_nat, _("\ | |
b84876c2 PA |
5227 | Set debugging of GNU/Linux lwp module."), _("\ |
5228 | Show debugging of GNU/Linux lwp module."), _("\ | |
5229 | Enables printf debugging output."), | |
ccce17b0 YQ |
5230 | NULL, |
5231 | show_debug_linux_nat, | |
5232 | &setdebuglist, &showdebuglist); | |
b84876c2 | 5233 | |
b84876c2 | 5234 | /* Save this mask as the default. */ |
d6b0e80f AC |
5235 | sigprocmask (SIG_SETMASK, NULL, &normal_mask); |
5236 | ||
7feb7d06 PA |
5237 | /* Install a SIGCHLD handler. */ |
5238 | sigchld_action.sa_handler = sigchld_handler; | |
5239 | sigemptyset (&sigchld_action.sa_mask); | |
5240 | sigchld_action.sa_flags = SA_RESTART; | |
b84876c2 PA |
5241 | |
5242 | /* Make it the default. */ | |
7feb7d06 | 5243 | sigaction (SIGCHLD, &sigchld_action, NULL); |
d6b0e80f AC |
5244 | |
5245 | /* Make sure we don't block SIGCHLD during a sigsuspend. */ | |
5246 | sigprocmask (SIG_SETMASK, NULL, &suspend_mask); | |
5247 | sigdelset (&suspend_mask, SIGCHLD); | |
5248 | ||
7feb7d06 | 5249 | sigemptyset (&blocked_mask); |
d6b0e80f AC |
5250 | } |
5251 | \f | |
5252 | ||
5253 | /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to | |
5254 | the GNU/Linux Threads library and therefore doesn't really belong | |
5255 | here. */ | |
5256 | ||
5257 | /* Read variable NAME in the target and return its value if found. | |
5258 | Otherwise return zero. It is assumed that the type of the variable | |
5259 | is `int'. */ | |
5260 | ||
5261 | static int | |
5262 | get_signo (const char *name) | |
5263 | { | |
5264 | struct minimal_symbol *ms; | |
5265 | int signo; | |
5266 | ||
5267 | ms = lookup_minimal_symbol (name, NULL, NULL); | |
5268 | if (ms == NULL) | |
5269 | return 0; | |
5270 | ||
8e70166d | 5271 | if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo, |
d6b0e80f AC |
5272 | sizeof (signo)) != 0) |
5273 | return 0; | |
5274 | ||
5275 | return signo; | |
5276 | } | |
5277 | ||
5278 | /* Return the set of signals used by the threads library in *SET. */ | |
5279 | ||
5280 | void | |
5281 | lin_thread_get_thread_signals (sigset_t *set) | |
5282 | { | |
5283 | struct sigaction action; | |
5284 | int restart, cancel; | |
5285 | ||
b84876c2 | 5286 | sigemptyset (&blocked_mask); |
d6b0e80f AC |
5287 | sigemptyset (set); |
5288 | ||
5289 | restart = get_signo ("__pthread_sig_restart"); | |
17fbb0bd DJ |
5290 | cancel = get_signo ("__pthread_sig_cancel"); |
5291 | ||
5292 | /* LinuxThreads normally uses the first two RT signals, but in some legacy | |
5293 | cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does | |
5294 | not provide any way for the debugger to query the signal numbers - | |
5295 | fortunately they don't change! */ | |
5296 | ||
d6b0e80f | 5297 | if (restart == 0) |
17fbb0bd | 5298 | restart = __SIGRTMIN; |
d6b0e80f | 5299 | |
d6b0e80f | 5300 | if (cancel == 0) |
17fbb0bd | 5301 | cancel = __SIGRTMIN + 1; |
d6b0e80f AC |
5302 | |
5303 | sigaddset (set, restart); | |
5304 | sigaddset (set, cancel); | |
5305 | ||
5306 | /* The GNU/Linux Threads library makes terminating threads send a | |
5307 | special "cancel" signal instead of SIGCHLD. Make sure we catch | |
5308 | those (to prevent them from terminating GDB itself, which is | |
5309 | likely to be their default action) and treat them the same way as | |
5310 | SIGCHLD. */ | |
5311 | ||
5312 | action.sa_handler = sigchld_handler; | |
5313 | sigemptyset (&action.sa_mask); | |
58aecb61 | 5314 | action.sa_flags = SA_RESTART; |
d6b0e80f AC |
5315 | sigaction (cancel, &action, NULL); |
5316 | ||
5317 | /* We block the "cancel" signal throughout this code ... */ | |
5318 | sigaddset (&blocked_mask, cancel); | |
5319 | sigprocmask (SIG_BLOCK, &blocked_mask, NULL); | |
5320 | ||
5321 | /* ... except during a sigsuspend. */ | |
5322 | sigdelset (&suspend_mask, cancel); | |
5323 | } |