Commit | Line | Data |
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3993f6b1 | 1 | /* GNU/Linux native-dependent code common to multiple platforms. |
dba24537 | 2 | |
3666a048 | 3 | Copyright (C) 2001-2021 Free Software Foundation, Inc. |
3993f6b1 DJ |
4 | |
5 | This file is part of GDB. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
a9762ec7 | 9 | the Free Software Foundation; either version 3 of the License, or |
3993f6b1 DJ |
10 | (at your option) any later version. |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
a9762ec7 | 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
3993f6b1 DJ |
19 | |
20 | #include "defs.h" | |
21 | #include "inferior.h" | |
45741a9c | 22 | #include "infrun.h" |
3993f6b1 | 23 | #include "target.h" |
96d7229d LM |
24 | #include "nat/linux-nat.h" |
25 | #include "nat/linux-waitpid.h" | |
268a13a5 | 26 | #include "gdbsupport/gdb_wait.h" |
d6b0e80f AC |
27 | #include <unistd.h> |
28 | #include <sys/syscall.h> | |
5826e159 | 29 | #include "nat/gdb_ptrace.h" |
0274a8ce | 30 | #include "linux-nat.h" |
125f8a3d GB |
31 | #include "nat/linux-ptrace.h" |
32 | #include "nat/linux-procfs.h" | |
8cc73a39 | 33 | #include "nat/linux-personality.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" | |
1777feb0 | 42 | #include <sys/procfs.h> /* for elf_gregset etc. */ |
dba24537 AC |
43 | #include "elf-bfd.h" /* for elfcore_write_* */ |
44 | #include "gregset.h" /* for gregset */ | |
45 | #include "gdbcore.h" /* for get_exec_file */ | |
46 | #include <ctype.h> /* for isdigit */ | |
53ce3c39 | 47 | #include <sys/stat.h> /* for struct stat */ |
dba24537 | 48 | #include <fcntl.h> /* for O_RDONLY */ |
b84876c2 | 49 | #include "inf-loop.h" |
400b5eca | 50 | #include "gdbsupport/event-loop.h" |
b84876c2 | 51 | #include "event-top.h" |
07e059b5 VP |
52 | #include <pwd.h> |
53 | #include <sys/types.h> | |
2978b111 | 54 | #include <dirent.h> |
07e059b5 | 55 | #include "xml-support.h" |
efcbbd14 | 56 | #include <sys/vfs.h> |
6c95b8df | 57 | #include "solib.h" |
125f8a3d | 58 | #include "nat/linux-osdata.h" |
6432734d | 59 | #include "linux-tdep.h" |
7dcd53a0 | 60 | #include "symfile.h" |
268a13a5 | 61 | #include "gdbsupport/agent.h" |
5808517f | 62 | #include "tracepoint.h" |
268a13a5 | 63 | #include "gdbsupport/buffer.h" |
6ecd4729 | 64 | #include "target-descriptions.h" |
268a13a5 | 65 | #include "gdbsupport/filestuff.h" |
77e371c0 | 66 | #include "objfiles.h" |
7a6a1731 | 67 | #include "nat/linux-namespaces.h" |
268a13a5 TT |
68 | #include "gdbsupport/fileio.h" |
69 | #include "gdbsupport/scope-exit.h" | |
21987b9c | 70 | #include "gdbsupport/gdb-sigmask.h" |
ba988419 | 71 | #include "gdbsupport/common-debug.h" |
efcbbd14 | 72 | |
1777feb0 | 73 | /* This comment documents high-level logic of this file. |
8a77dff3 VP |
74 | |
75 | Waiting for events in sync mode | |
76 | =============================== | |
77 | ||
4a6ed09b PA |
78 | When waiting for an event in a specific thread, we just use waitpid, |
79 | passing the specific pid, and not passing WNOHANG. | |
80 | ||
81 | When waiting for an event in all threads, waitpid is not quite good: | |
82 | ||
83 | - If the thread group leader exits while other threads in the thread | |
84 | group still exist, waitpid(TGID, ...) hangs. That waitpid won't | |
85 | return an exit status until the other threads in the group are | |
86 | reaped. | |
87 | ||
88 | - When a non-leader thread execs, that thread just vanishes without | |
89 | reporting an exit (so we'd hang if we waited for it explicitly in | |
90 | that case). The exec event is instead reported to the TGID pid. | |
91 | ||
92 | The solution is to always use -1 and WNOHANG, together with | |
93 | sigsuspend. | |
94 | ||
95 | First, we use non-blocking waitpid to check for events. If nothing is | |
96 | found, we use sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, | |
97 | it means something happened to a child process. As soon as we know | |
98 | there's an event, we get back to calling nonblocking waitpid. | |
99 | ||
100 | Note that SIGCHLD should be blocked between waitpid and sigsuspend | |
101 | calls, so that we don't miss a signal. If SIGCHLD arrives in between, | |
102 | when it's blocked, the signal becomes pending and sigsuspend | |
103 | immediately notices it and returns. | |
104 | ||
105 | Waiting for events in async mode (TARGET_WNOHANG) | |
106 | ================================================= | |
8a77dff3 | 107 | |
7feb7d06 PA |
108 | In async mode, GDB should always be ready to handle both user input |
109 | and target events, so neither blocking waitpid nor sigsuspend are | |
110 | viable options. Instead, we should asynchronously notify the GDB main | |
111 | event loop whenever there's an unprocessed event from the target. We | |
112 | detect asynchronous target events by handling SIGCHLD signals. To | |
113 | notify the event loop about target events, the self-pipe trick is used | |
114 | --- a pipe is registered as waitable event source in the event loop, | |
115 | the event loop select/poll's on the read end of this pipe (as well on | |
116 | other event sources, e.g., stdin), and the SIGCHLD handler writes a | |
117 | byte to this pipe. This is more portable than relying on | |
118 | pselect/ppoll, since on kernels that lack those syscalls, libc | |
119 | emulates them with select/poll+sigprocmask, and that is racy | |
120 | (a.k.a. plain broken). | |
121 | ||
122 | Obviously, if we fail to notify the event loop if there's a target | |
123 | event, it's bad. OTOH, if we notify the event loop when there's no | |
124 | event from the target, linux_nat_wait will detect that there's no real | |
125 | event to report, and return event of type TARGET_WAITKIND_IGNORE. | |
126 | This is mostly harmless, but it will waste time and is better avoided. | |
127 | ||
128 | The main design point is that every time GDB is outside linux-nat.c, | |
129 | we have a SIGCHLD handler installed that is called when something | |
130 | happens to the target and notifies the GDB event loop. Whenever GDB | |
131 | core decides to handle the event, and calls into linux-nat.c, we | |
132 | process things as in sync mode, except that the we never block in | |
133 | sigsuspend. | |
134 | ||
135 | While processing an event, we may end up momentarily blocked in | |
136 | waitpid calls. Those waitpid calls, while blocking, are guarantied to | |
137 | return quickly. E.g., in all-stop mode, before reporting to the core | |
138 | that an LWP hit a breakpoint, all LWPs are stopped by sending them | |
139 | SIGSTOP, and synchronously waiting for the SIGSTOP to be reported. | |
140 | Note that this is different from blocking indefinitely waiting for the | |
141 | next event --- here, we're already handling an event. | |
8a77dff3 VP |
142 | |
143 | Use of signals | |
144 | ============== | |
145 | ||
146 | We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another | |
147 | signal is not entirely significant; we just need for a signal to be delivered, | |
148 | so that we can intercept it. SIGSTOP's advantage is that it can not be | |
149 | blocked. A disadvantage is that it is not a real-time signal, so it can only | |
150 | be queued once; we do not keep track of other sources of SIGSTOP. | |
151 | ||
152 | Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't | |
153 | use them, because they have special behavior when the signal is generated - | |
154 | not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL | |
155 | kills the entire thread group. | |
156 | ||
157 | A delivered SIGSTOP would stop the entire thread group, not just the thread we | |
158 | tkill'd. But we never let the SIGSTOP be delivered; we always intercept and | |
159 | cancel it (by PTRACE_CONT without passing SIGSTOP). | |
160 | ||
161 | We could use a real-time signal instead. This would solve those problems; we | |
162 | could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB. | |
163 | But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH | |
164 | generates it, and there are races with trying to find a signal that is not | |
4a6ed09b PA |
165 | blocked. |
166 | ||
167 | Exec events | |
168 | =========== | |
169 | ||
170 | The case of a thread group (process) with 3 or more threads, and a | |
171 | thread other than the leader execs is worth detailing: | |
172 | ||
173 | On an exec, the Linux kernel destroys all threads except the execing | |
174 | one in the thread group, and resets the execing thread's tid to the | |
175 | tgid. No exit notification is sent for the execing thread -- from the | |
176 | ptracer's perspective, it appears as though the execing thread just | |
177 | vanishes. Until we reap all other threads except the leader and the | |
178 | execing thread, the leader will be zombie, and the execing thread will | |
179 | be in `D (disc sleep)' state. As soon as all other threads are | |
180 | reaped, the execing thread changes its tid to the tgid, and the | |
181 | previous (zombie) leader vanishes, giving place to the "new" | |
182 | leader. */ | |
a0ef4274 | 183 | |
dba24537 AC |
184 | #ifndef O_LARGEFILE |
185 | #define O_LARGEFILE 0 | |
186 | #endif | |
0274a8ce | 187 | |
f6ac5f3d PA |
188 | struct linux_nat_target *linux_target; |
189 | ||
433bbbf8 | 190 | /* Does the current host support PTRACE_GETREGSET? */ |
0bdb2f78 | 191 | enum tribool have_ptrace_getregset = TRIBOOL_UNKNOWN; |
433bbbf8 | 192 | |
ccce17b0 | 193 | static unsigned int debug_linux_nat; |
920d2a44 AC |
194 | static void |
195 | show_debug_linux_nat (struct ui_file *file, int from_tty, | |
196 | struct cmd_list_element *c, const char *value) | |
197 | { | |
198 | fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"), | |
199 | value); | |
200 | } | |
d6b0e80f | 201 | |
17417fb0 | 202 | /* Print a linux-nat debug statement. */ |
9327494e SM |
203 | |
204 | #define linux_nat_debug_printf(fmt, ...) \ | |
74b773fc | 205 | debug_prefixed_printf_cond (debug_linux_nat, "linux-nat", fmt, ##__VA_ARGS__) |
9327494e | 206 | |
ae087d01 DJ |
207 | struct simple_pid_list |
208 | { | |
209 | int pid; | |
3d799a95 | 210 | int status; |
ae087d01 DJ |
211 | struct simple_pid_list *next; |
212 | }; | |
05c309a8 | 213 | static struct simple_pid_list *stopped_pids; |
ae087d01 | 214 | |
aa01bd36 PA |
215 | /* Whether target_thread_events is in effect. */ |
216 | static int report_thread_events; | |
217 | ||
3dd5b83d PA |
218 | /* Async mode support. */ |
219 | ||
b84876c2 PA |
220 | /* The read/write ends of the pipe registered as waitable file in the |
221 | event loop. */ | |
222 | static int linux_nat_event_pipe[2] = { -1, -1 }; | |
223 | ||
198297aa PA |
224 | /* True if we're currently in async mode. */ |
225 | #define linux_is_async_p() (linux_nat_event_pipe[0] != -1) | |
226 | ||
7feb7d06 | 227 | /* Flush the event pipe. */ |
b84876c2 | 228 | |
7feb7d06 PA |
229 | static void |
230 | async_file_flush (void) | |
b84876c2 | 231 | { |
7feb7d06 PA |
232 | int ret; |
233 | char buf; | |
b84876c2 | 234 | |
7feb7d06 | 235 | do |
b84876c2 | 236 | { |
7feb7d06 | 237 | ret = read (linux_nat_event_pipe[0], &buf, 1); |
b84876c2 | 238 | } |
7feb7d06 | 239 | while (ret >= 0 || (ret == -1 && errno == EINTR)); |
b84876c2 PA |
240 | } |
241 | ||
7feb7d06 PA |
242 | /* Put something (anything, doesn't matter what, or how much) in event |
243 | pipe, so that the select/poll in the event-loop realizes we have | |
244 | something to process. */ | |
252fbfc8 | 245 | |
b84876c2 | 246 | static void |
7feb7d06 | 247 | async_file_mark (void) |
b84876c2 | 248 | { |
7feb7d06 | 249 | int ret; |
b84876c2 | 250 | |
7feb7d06 PA |
251 | /* It doesn't really matter what the pipe contains, as long we end |
252 | up with something in it. Might as well flush the previous | |
253 | left-overs. */ | |
254 | async_file_flush (); | |
b84876c2 | 255 | |
7feb7d06 | 256 | do |
b84876c2 | 257 | { |
7feb7d06 | 258 | ret = write (linux_nat_event_pipe[1], "+", 1); |
b84876c2 | 259 | } |
7feb7d06 | 260 | while (ret == -1 && errno == EINTR); |
b84876c2 | 261 | |
7feb7d06 PA |
262 | /* Ignore EAGAIN. If the pipe is full, the event loop will already |
263 | be awakened anyway. */ | |
b84876c2 PA |
264 | } |
265 | ||
7feb7d06 PA |
266 | static int kill_lwp (int lwpid, int signo); |
267 | ||
d3a70e03 | 268 | static int stop_callback (struct lwp_info *lp); |
7feb7d06 PA |
269 | |
270 | static void block_child_signals (sigset_t *prev_mask); | |
271 | static void restore_child_signals_mask (sigset_t *prev_mask); | |
2277426b PA |
272 | |
273 | struct lwp_info; | |
274 | static struct lwp_info *add_lwp (ptid_t ptid); | |
275 | static void purge_lwp_list (int pid); | |
4403d8e9 | 276 | static void delete_lwp (ptid_t ptid); |
2277426b PA |
277 | static struct lwp_info *find_lwp_pid (ptid_t ptid); |
278 | ||
8a99810d PA |
279 | static int lwp_status_pending_p (struct lwp_info *lp); |
280 | ||
e7ad2f14 PA |
281 | static void save_stop_reason (struct lwp_info *lp); |
282 | ||
05c06f31 PA |
283 | static void maybe_close_proc_mem_file (pid_t pid); |
284 | ||
cff068da GB |
285 | \f |
286 | /* LWP accessors. */ | |
287 | ||
288 | /* See nat/linux-nat.h. */ | |
289 | ||
290 | ptid_t | |
291 | ptid_of_lwp (struct lwp_info *lwp) | |
292 | { | |
293 | return lwp->ptid; | |
294 | } | |
295 | ||
296 | /* See nat/linux-nat.h. */ | |
297 | ||
4b134ca1 GB |
298 | void |
299 | lwp_set_arch_private_info (struct lwp_info *lwp, | |
300 | struct arch_lwp_info *info) | |
301 | { | |
302 | lwp->arch_private = info; | |
303 | } | |
304 | ||
305 | /* See nat/linux-nat.h. */ | |
306 | ||
307 | struct arch_lwp_info * | |
308 | lwp_arch_private_info (struct lwp_info *lwp) | |
309 | { | |
310 | return lwp->arch_private; | |
311 | } | |
312 | ||
313 | /* See nat/linux-nat.h. */ | |
314 | ||
cff068da GB |
315 | int |
316 | lwp_is_stopped (struct lwp_info *lwp) | |
317 | { | |
318 | return lwp->stopped; | |
319 | } | |
320 | ||
321 | /* See nat/linux-nat.h. */ | |
322 | ||
323 | enum target_stop_reason | |
324 | lwp_stop_reason (struct lwp_info *lwp) | |
325 | { | |
326 | return lwp->stop_reason; | |
327 | } | |
328 | ||
0e00e962 AA |
329 | /* See nat/linux-nat.h. */ |
330 | ||
331 | int | |
332 | lwp_is_stepping (struct lwp_info *lwp) | |
333 | { | |
334 | return lwp->step; | |
335 | } | |
336 | ||
ae087d01 DJ |
337 | \f |
338 | /* Trivial list manipulation functions to keep track of a list of | |
339 | new stopped processes. */ | |
340 | static void | |
3d799a95 | 341 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
ae087d01 | 342 | { |
8d749320 | 343 | struct simple_pid_list *new_pid = XNEW (struct simple_pid_list); |
e0881a8e | 344 | |
ae087d01 | 345 | new_pid->pid = pid; |
3d799a95 | 346 | new_pid->status = status; |
ae087d01 DJ |
347 | new_pid->next = *listp; |
348 | *listp = new_pid; | |
349 | } | |
350 | ||
351 | static int | |
46a96992 | 352 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
ae087d01 DJ |
353 | { |
354 | struct simple_pid_list **p; | |
355 | ||
356 | for (p = listp; *p != NULL; p = &(*p)->next) | |
357 | if ((*p)->pid == pid) | |
358 | { | |
359 | struct simple_pid_list *next = (*p)->next; | |
e0881a8e | 360 | |
46a96992 | 361 | *statusp = (*p)->status; |
ae087d01 DJ |
362 | xfree (*p); |
363 | *p = next; | |
364 | return 1; | |
365 | } | |
366 | return 0; | |
367 | } | |
368 | ||
de0d863e DB |
369 | /* Return the ptrace options that we want to try to enable. */ |
370 | ||
371 | static int | |
372 | linux_nat_ptrace_options (int attached) | |
373 | { | |
374 | int options = 0; | |
375 | ||
376 | if (!attached) | |
377 | options |= PTRACE_O_EXITKILL; | |
378 | ||
379 | options |= (PTRACE_O_TRACESYSGOOD | |
380 | | PTRACE_O_TRACEVFORKDONE | |
381 | | PTRACE_O_TRACEVFORK | |
382 | | PTRACE_O_TRACEFORK | |
383 | | PTRACE_O_TRACEEXEC); | |
384 | ||
385 | return options; | |
386 | } | |
387 | ||
1b919490 VB |
388 | /* Initialize ptrace and procfs warnings and check for supported |
389 | ptrace features given PID. | |
beed38b8 JB |
390 | |
391 | ATTACHED should be nonzero iff we attached to the inferior. */ | |
3993f6b1 DJ |
392 | |
393 | static void | |
1b919490 | 394 | linux_init_ptrace_procfs (pid_t pid, int attached) |
3993f6b1 | 395 | { |
de0d863e DB |
396 | int options = linux_nat_ptrace_options (attached); |
397 | ||
398 | linux_enable_event_reporting (pid, options); | |
96d7229d | 399 | linux_ptrace_init_warnings (); |
1b919490 | 400 | linux_proc_init_warnings (); |
4de4c07c DJ |
401 | } |
402 | ||
f6ac5f3d PA |
403 | linux_nat_target::~linux_nat_target () |
404 | {} | |
405 | ||
406 | void | |
407 | linux_nat_target::post_attach (int pid) | |
4de4c07c | 408 | { |
1b919490 | 409 | linux_init_ptrace_procfs (pid, 1); |
4de4c07c DJ |
410 | } |
411 | ||
f6ac5f3d PA |
412 | void |
413 | linux_nat_target::post_startup_inferior (ptid_t ptid) | |
4de4c07c | 414 | { |
1b919490 | 415 | linux_init_ptrace_procfs (ptid.pid (), 0); |
4de4c07c DJ |
416 | } |
417 | ||
4403d8e9 JK |
418 | /* Return the number of known LWPs in the tgid given by PID. */ |
419 | ||
420 | static int | |
421 | num_lwps (int pid) | |
422 | { | |
423 | int count = 0; | |
424 | struct lwp_info *lp; | |
425 | ||
426 | for (lp = lwp_list; lp; lp = lp->next) | |
e99b03dc | 427 | if (lp->ptid.pid () == pid) |
4403d8e9 JK |
428 | count++; |
429 | ||
430 | return count; | |
431 | } | |
432 | ||
169bb27b | 433 | /* Deleter for lwp_info unique_ptr specialisation. */ |
4403d8e9 | 434 | |
169bb27b | 435 | struct lwp_deleter |
4403d8e9 | 436 | { |
169bb27b AB |
437 | void operator() (struct lwp_info *lwp) const |
438 | { | |
439 | delete_lwp (lwp->ptid); | |
440 | } | |
441 | }; | |
4403d8e9 | 442 | |
169bb27b AB |
443 | /* A unique_ptr specialisation for lwp_info. */ |
444 | ||
445 | typedef std::unique_ptr<struct lwp_info, lwp_deleter> lwp_info_up; | |
4403d8e9 | 446 | |
d83ad864 DB |
447 | /* Target hook for follow_fork. On entry inferior_ptid must be the |
448 | ptid of the followed inferior. At return, inferior_ptid will be | |
449 | unchanged. */ | |
450 | ||
e97007b6 | 451 | void |
5ab2fbf1 | 452 | linux_nat_target::follow_fork (bool follow_child, bool detach_fork) |
3993f6b1 | 453 | { |
d83ad864 | 454 | if (!follow_child) |
4de4c07c | 455 | { |
6c95b8df | 456 | struct lwp_info *child_lp = NULL; |
d83ad864 | 457 | int has_vforked; |
79639e11 | 458 | ptid_t parent_ptid, child_ptid; |
d83ad864 DB |
459 | int parent_pid, child_pid; |
460 | ||
461 | has_vforked = (inferior_thread ()->pending_follow.kind | |
462 | == TARGET_WAITKIND_VFORKED); | |
79639e11 PA |
463 | parent_ptid = inferior_ptid; |
464 | child_ptid = inferior_thread ()->pending_follow.value.related_pid; | |
e38504b3 TT |
465 | parent_pid = parent_ptid.lwp (); |
466 | child_pid = child_ptid.lwp (); | |
4de4c07c | 467 | |
1777feb0 | 468 | /* We're already attached to the parent, by default. */ |
2989a365 | 469 | child_lp = add_lwp (child_ptid); |
d83ad864 DB |
470 | child_lp->stopped = 1; |
471 | child_lp->last_resume_kind = resume_stop; | |
4de4c07c | 472 | |
ac264b3b MS |
473 | /* Detach new forked process? */ |
474 | if (detach_fork) | |
f75c00e4 | 475 | { |
95347337 AB |
476 | int child_stop_signal = 0; |
477 | bool detach_child = true; | |
4403d8e9 | 478 | |
169bb27b AB |
479 | /* Move CHILD_LP into a unique_ptr and clear the source pointer |
480 | to prevent us doing anything stupid with it. */ | |
481 | lwp_info_up child_lp_ptr (child_lp); | |
482 | child_lp = nullptr; | |
483 | ||
484 | linux_target->low_prepare_to_resume (child_lp_ptr.get ()); | |
c077881a HZ |
485 | |
486 | /* When debugging an inferior in an architecture that supports | |
487 | hardware single stepping on a kernel without commit | |
488 | 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child | |
489 | process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits | |
490 | set if the parent process had them set. | |
491 | To work around this, single step the child process | |
492 | once before detaching to clear the flags. */ | |
493 | ||
2fd9d7ca PA |
494 | /* Note that we consult the parent's architecture instead of |
495 | the child's because there's no inferior for the child at | |
496 | this point. */ | |
c077881a | 497 | if (!gdbarch_software_single_step_p (target_thread_architecture |
2fd9d7ca | 498 | (parent_ptid))) |
c077881a | 499 | { |
95347337 AB |
500 | int status; |
501 | ||
c077881a HZ |
502 | linux_disable_event_reporting (child_pid); |
503 | if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0) | |
504 | perror_with_name (_("Couldn't do single step")); | |
505 | if (my_waitpid (child_pid, &status, 0) < 0) | |
506 | perror_with_name (_("Couldn't wait vfork process")); | |
95347337 AB |
507 | else |
508 | { | |
509 | detach_child = WIFSTOPPED (status); | |
510 | child_stop_signal = WSTOPSIG (status); | |
511 | } | |
c077881a HZ |
512 | } |
513 | ||
95347337 | 514 | if (detach_child) |
9caaaa83 | 515 | { |
95347337 | 516 | int signo = child_stop_signal; |
9caaaa83 | 517 | |
9caaaa83 PA |
518 | if (signo != 0 |
519 | && !signal_pass_state (gdb_signal_from_host (signo))) | |
520 | signo = 0; | |
521 | ptrace (PTRACE_DETACH, child_pid, 0, signo); | |
522 | } | |
ac264b3b MS |
523 | } |
524 | else | |
525 | { | |
5b6d1e4f PA |
526 | /* Switching inferior_ptid is not enough, because then |
527 | inferior_thread () would crash by not finding the thread | |
528 | in the current inferior. */ | |
529 | scoped_restore_current_thread restore_current_thread; | |
530 | thread_info *child = find_thread_ptid (this, child_ptid); | |
531 | switch_to_thread (child); | |
2989a365 | 532 | |
6c95b8df | 533 | /* Let the thread_db layer learn about this new process. */ |
2277426b | 534 | check_for_thread_db (); |
ac264b3b | 535 | } |
9016a515 DJ |
536 | |
537 | if (has_vforked) | |
538 | { | |
3ced3da4 | 539 | struct lwp_info *parent_lp; |
6c95b8df | 540 | |
79639e11 | 541 | parent_lp = find_lwp_pid (parent_ptid); |
96d7229d | 542 | gdb_assert (linux_supports_tracefork () >= 0); |
3ced3da4 | 543 | |
96d7229d | 544 | if (linux_supports_tracevforkdone ()) |
9016a515 | 545 | { |
9327494e SM |
546 | linux_nat_debug_printf ("waiting for VFORK_DONE on %d", |
547 | parent_pid); | |
3ced3da4 | 548 | parent_lp->stopped = 1; |
9016a515 | 549 | |
6c95b8df PA |
550 | /* We'll handle the VFORK_DONE event like any other |
551 | event, in target_wait. */ | |
9016a515 DJ |
552 | } |
553 | else | |
554 | { | |
555 | /* We can't insert breakpoints until the child has | |
556 | finished with the shared memory region. We need to | |
557 | wait until that happens. Ideal would be to just | |
558 | call: | |
559 | - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0); | |
560 | - waitpid (parent_pid, &status, __WALL); | |
561 | However, most architectures can't handle a syscall | |
562 | being traced on the way out if it wasn't traced on | |
563 | the way in. | |
564 | ||
565 | We might also think to loop, continuing the child | |
566 | until it exits or gets a SIGTRAP. One problem is | |
567 | that the child might call ptrace with PTRACE_TRACEME. | |
568 | ||
569 | There's no simple and reliable way to figure out when | |
570 | the vforked child will be done with its copy of the | |
571 | shared memory. We could step it out of the syscall, | |
572 | two instructions, let it go, and then single-step the | |
573 | parent once. When we have hardware single-step, this | |
574 | would work; with software single-step it could still | |
575 | be made to work but we'd have to be able to insert | |
576 | single-step breakpoints in the child, and we'd have | |
577 | to insert -just- the single-step breakpoint in the | |
578 | parent. Very awkward. | |
579 | ||
580 | In the end, the best we can do is to make sure it | |
581 | runs for a little while. Hopefully it will be out of | |
582 | range of any breakpoints we reinsert. Usually this | |
583 | is only the single-step breakpoint at vfork's return | |
584 | point. */ | |
585 | ||
9327494e | 586 | linux_nat_debug_printf ("no VFORK_DONE support, sleeping a bit"); |
6c95b8df | 587 | |
9016a515 | 588 | usleep (10000); |
9016a515 | 589 | |
6c95b8df PA |
590 | /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event, |
591 | and leave it pending. The next linux_nat_resume call | |
592 | will notice a pending event, and bypasses actually | |
593 | resuming the inferior. */ | |
3ced3da4 PA |
594 | parent_lp->status = 0; |
595 | parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE; | |
596 | parent_lp->stopped = 1; | |
6c95b8df PA |
597 | |
598 | /* If we're in async mode, need to tell the event loop | |
599 | there's something here to process. */ | |
d9d41e78 | 600 | if (target_is_async_p ()) |
6c95b8df PA |
601 | async_file_mark (); |
602 | } | |
9016a515 | 603 | } |
4de4c07c | 604 | } |
3993f6b1 | 605 | else |
4de4c07c | 606 | { |
3ced3da4 | 607 | struct lwp_info *child_lp; |
4de4c07c | 608 | |
3ced3da4 PA |
609 | child_lp = add_lwp (inferior_ptid); |
610 | child_lp->stopped = 1; | |
25289eb2 | 611 | child_lp->last_resume_kind = resume_stop; |
6c95b8df | 612 | |
6c95b8df | 613 | /* Let the thread_db layer learn about this new process. */ |
ef29ce1a | 614 | check_for_thread_db (); |
4de4c07c | 615 | } |
4de4c07c DJ |
616 | } |
617 | ||
4de4c07c | 618 | \f |
f6ac5f3d PA |
619 | int |
620 | linux_nat_target::insert_fork_catchpoint (int pid) | |
4de4c07c | 621 | { |
96d7229d | 622 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
623 | } |
624 | ||
f6ac5f3d PA |
625 | int |
626 | linux_nat_target::remove_fork_catchpoint (int pid) | |
eb73ad13 PA |
627 | { |
628 | return 0; | |
629 | } | |
630 | ||
f6ac5f3d PA |
631 | int |
632 | linux_nat_target::insert_vfork_catchpoint (int pid) | |
3993f6b1 | 633 | { |
96d7229d | 634 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
635 | } |
636 | ||
f6ac5f3d PA |
637 | int |
638 | linux_nat_target::remove_vfork_catchpoint (int pid) | |
eb73ad13 PA |
639 | { |
640 | return 0; | |
641 | } | |
642 | ||
f6ac5f3d PA |
643 | int |
644 | linux_nat_target::insert_exec_catchpoint (int pid) | |
3993f6b1 | 645 | { |
96d7229d | 646 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
647 | } |
648 | ||
f6ac5f3d PA |
649 | int |
650 | linux_nat_target::remove_exec_catchpoint (int pid) | |
eb73ad13 PA |
651 | { |
652 | return 0; | |
653 | } | |
654 | ||
f6ac5f3d PA |
655 | int |
656 | linux_nat_target::set_syscall_catchpoint (int pid, bool needed, int any_count, | |
657 | gdb::array_view<const int> syscall_counts) | |
a96d9b2e | 658 | { |
96d7229d | 659 | if (!linux_supports_tracesysgood ()) |
77b06cd7 TJB |
660 | return 1; |
661 | ||
a96d9b2e SDJ |
662 | /* On GNU/Linux, we ignore the arguments. It means that we only |
663 | enable the syscall catchpoints, but do not disable them. | |
77b06cd7 | 664 | |
649a140c | 665 | Also, we do not use the `syscall_counts' information because we do not |
a96d9b2e SDJ |
666 | filter system calls here. We let GDB do the logic for us. */ |
667 | return 0; | |
668 | } | |
669 | ||
774113b0 PA |
670 | /* List of known LWPs, keyed by LWP PID. This speeds up the common |
671 | case of mapping a PID returned from the kernel to our corresponding | |
672 | lwp_info data structure. */ | |
673 | static htab_t lwp_lwpid_htab; | |
674 | ||
675 | /* Calculate a hash from a lwp_info's LWP PID. */ | |
676 | ||
677 | static hashval_t | |
678 | lwp_info_hash (const void *ap) | |
679 | { | |
680 | const struct lwp_info *lp = (struct lwp_info *) ap; | |
e38504b3 | 681 | pid_t pid = lp->ptid.lwp (); |
774113b0 PA |
682 | |
683 | return iterative_hash_object (pid, 0); | |
684 | } | |
685 | ||
686 | /* Equality function for the lwp_info hash table. Compares the LWP's | |
687 | PID. */ | |
688 | ||
689 | static int | |
690 | lwp_lwpid_htab_eq (const void *a, const void *b) | |
691 | { | |
692 | const struct lwp_info *entry = (const struct lwp_info *) a; | |
693 | const struct lwp_info *element = (const struct lwp_info *) b; | |
694 | ||
e38504b3 | 695 | return entry->ptid.lwp () == element->ptid.lwp (); |
774113b0 PA |
696 | } |
697 | ||
698 | /* Create the lwp_lwpid_htab hash table. */ | |
699 | ||
700 | static void | |
701 | lwp_lwpid_htab_create (void) | |
702 | { | |
703 | lwp_lwpid_htab = htab_create (100, lwp_info_hash, lwp_lwpid_htab_eq, NULL); | |
704 | } | |
705 | ||
706 | /* Add LP to the hash table. */ | |
707 | ||
708 | static void | |
709 | lwp_lwpid_htab_add_lwp (struct lwp_info *lp) | |
710 | { | |
711 | void **slot; | |
712 | ||
713 | slot = htab_find_slot (lwp_lwpid_htab, lp, INSERT); | |
714 | gdb_assert (slot != NULL && *slot == NULL); | |
715 | *slot = lp; | |
716 | } | |
717 | ||
718 | /* Head of doubly-linked list of known LWPs. Sorted by reverse | |
719 | creation order. This order is assumed in some cases. E.g., | |
720 | reaping status after killing alls lwps of a process: the leader LWP | |
721 | must be reaped last. */ | |
9f0bdab8 | 722 | struct lwp_info *lwp_list; |
774113b0 PA |
723 | |
724 | /* Add LP to sorted-by-reverse-creation-order doubly-linked list. */ | |
725 | ||
726 | static void | |
727 | lwp_list_add (struct lwp_info *lp) | |
728 | { | |
729 | lp->next = lwp_list; | |
730 | if (lwp_list != NULL) | |
731 | lwp_list->prev = lp; | |
732 | lwp_list = lp; | |
733 | } | |
734 | ||
735 | /* Remove LP from sorted-by-reverse-creation-order doubly-linked | |
736 | list. */ | |
737 | ||
738 | static void | |
739 | lwp_list_remove (struct lwp_info *lp) | |
740 | { | |
741 | /* Remove from sorted-by-creation-order list. */ | |
742 | if (lp->next != NULL) | |
743 | lp->next->prev = lp->prev; | |
744 | if (lp->prev != NULL) | |
745 | lp->prev->next = lp->next; | |
746 | if (lp == lwp_list) | |
747 | lwp_list = lp->next; | |
748 | } | |
749 | ||
d6b0e80f AC |
750 | \f |
751 | ||
d6b0e80f AC |
752 | /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in |
753 | _initialize_linux_nat. */ | |
754 | static sigset_t suspend_mask; | |
755 | ||
7feb7d06 PA |
756 | /* Signals to block to make that sigsuspend work. */ |
757 | static sigset_t blocked_mask; | |
758 | ||
759 | /* SIGCHLD action. */ | |
6bd434d6 | 760 | static struct sigaction sigchld_action; |
b84876c2 | 761 | |
7feb7d06 PA |
762 | /* Block child signals (SIGCHLD and linux threads signals), and store |
763 | the previous mask in PREV_MASK. */ | |
84e46146 | 764 | |
7feb7d06 PA |
765 | static void |
766 | block_child_signals (sigset_t *prev_mask) | |
767 | { | |
768 | /* Make sure SIGCHLD is blocked. */ | |
769 | if (!sigismember (&blocked_mask, SIGCHLD)) | |
770 | sigaddset (&blocked_mask, SIGCHLD); | |
771 | ||
21987b9c | 772 | gdb_sigmask (SIG_BLOCK, &blocked_mask, prev_mask); |
7feb7d06 PA |
773 | } |
774 | ||
775 | /* Restore child signals mask, previously returned by | |
776 | block_child_signals. */ | |
777 | ||
778 | static void | |
779 | restore_child_signals_mask (sigset_t *prev_mask) | |
780 | { | |
21987b9c | 781 | gdb_sigmask (SIG_SETMASK, prev_mask, NULL); |
7feb7d06 | 782 | } |
2455069d UW |
783 | |
784 | /* Mask of signals to pass directly to the inferior. */ | |
785 | static sigset_t pass_mask; | |
786 | ||
787 | /* Update signals to pass to the inferior. */ | |
f6ac5f3d | 788 | void |
adc6a863 PA |
789 | linux_nat_target::pass_signals |
790 | (gdb::array_view<const unsigned char> pass_signals) | |
2455069d UW |
791 | { |
792 | int signo; | |
793 | ||
794 | sigemptyset (&pass_mask); | |
795 | ||
796 | for (signo = 1; signo < NSIG; signo++) | |
797 | { | |
2ea28649 | 798 | int target_signo = gdb_signal_from_host (signo); |
adc6a863 | 799 | if (target_signo < pass_signals.size () && pass_signals[target_signo]) |
dda83cd7 | 800 | sigaddset (&pass_mask, signo); |
2455069d UW |
801 | } |
802 | } | |
803 | ||
d6b0e80f AC |
804 | \f |
805 | ||
806 | /* Prototypes for local functions. */ | |
d3a70e03 TT |
807 | static int stop_wait_callback (struct lwp_info *lp); |
808 | static int resume_stopped_resumed_lwps (struct lwp_info *lp, const ptid_t wait_ptid); | |
ced2dffb | 809 | static int check_ptrace_stopped_lwp_gone (struct lwp_info *lp); |
710151dd | 810 | |
d6b0e80f | 811 | \f |
d6b0e80f | 812 | |
7b50312a PA |
813 | /* Destroy and free LP. */ |
814 | ||
815 | static void | |
816 | lwp_free (struct lwp_info *lp) | |
817 | { | |
466eecee | 818 | /* Let the arch specific bits release arch_lwp_info. */ |
135340af | 819 | linux_target->low_delete_thread (lp->arch_private); |
466eecee | 820 | |
7b50312a PA |
821 | xfree (lp); |
822 | } | |
823 | ||
774113b0 | 824 | /* Traversal function for purge_lwp_list. */ |
d90e17a7 | 825 | |
774113b0 PA |
826 | static int |
827 | lwp_lwpid_htab_remove_pid (void **slot, void *info) | |
d90e17a7 | 828 | { |
774113b0 PA |
829 | struct lwp_info *lp = (struct lwp_info *) *slot; |
830 | int pid = *(int *) info; | |
d90e17a7 | 831 | |
e99b03dc | 832 | if (lp->ptid.pid () == pid) |
d90e17a7 | 833 | { |
774113b0 PA |
834 | htab_clear_slot (lwp_lwpid_htab, slot); |
835 | lwp_list_remove (lp); | |
836 | lwp_free (lp); | |
837 | } | |
d90e17a7 | 838 | |
774113b0 PA |
839 | return 1; |
840 | } | |
d90e17a7 | 841 | |
774113b0 PA |
842 | /* Remove all LWPs belong to PID from the lwp list. */ |
843 | ||
844 | static void | |
845 | purge_lwp_list (int pid) | |
846 | { | |
847 | htab_traverse_noresize (lwp_lwpid_htab, lwp_lwpid_htab_remove_pid, &pid); | |
d90e17a7 PA |
848 | } |
849 | ||
26cb8b7c PA |
850 | /* Add the LWP specified by PTID to the list. PTID is the first LWP |
851 | in the process. Return a pointer to the structure describing the | |
852 | new LWP. | |
853 | ||
854 | This differs from add_lwp in that we don't let the arch specific | |
855 | bits know about this new thread. Current clients of this callback | |
856 | take the opportunity to install watchpoints in the new thread, and | |
857 | we shouldn't do that for the first thread. If we're spawning a | |
858 | child ("run"), the thread executes the shell wrapper first, and we | |
859 | shouldn't touch it until it execs the program we want to debug. | |
860 | For "attach", it'd be okay to call the callback, but it's not | |
861 | necessary, because watchpoints can't yet have been inserted into | |
862 | the inferior. */ | |
d6b0e80f AC |
863 | |
864 | static struct lwp_info * | |
26cb8b7c | 865 | add_initial_lwp (ptid_t ptid) |
d6b0e80f AC |
866 | { |
867 | struct lwp_info *lp; | |
868 | ||
15a9e13e | 869 | gdb_assert (ptid.lwp_p ()); |
d6b0e80f | 870 | |
8d749320 | 871 | lp = XNEW (struct lwp_info); |
d6b0e80f AC |
872 | |
873 | memset (lp, 0, sizeof (struct lwp_info)); | |
874 | ||
25289eb2 | 875 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
876 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
877 | ||
878 | lp->ptid = ptid; | |
dc146f7c | 879 | lp->core = -1; |
d6b0e80f | 880 | |
774113b0 PA |
881 | /* Add to sorted-by-reverse-creation-order list. */ |
882 | lwp_list_add (lp); | |
883 | ||
884 | /* Add to keyed-by-pid htab. */ | |
885 | lwp_lwpid_htab_add_lwp (lp); | |
d6b0e80f | 886 | |
26cb8b7c PA |
887 | return lp; |
888 | } | |
889 | ||
890 | /* Add the LWP specified by PID to the list. Return a pointer to the | |
891 | structure describing the new LWP. The LWP should already be | |
892 | stopped. */ | |
893 | ||
894 | static struct lwp_info * | |
895 | add_lwp (ptid_t ptid) | |
896 | { | |
897 | struct lwp_info *lp; | |
898 | ||
899 | lp = add_initial_lwp (ptid); | |
900 | ||
6e012a6c PA |
901 | /* Let the arch specific bits know about this new thread. Current |
902 | clients of this callback take the opportunity to install | |
26cb8b7c PA |
903 | watchpoints in the new thread. We don't do this for the first |
904 | thread though. See add_initial_lwp. */ | |
135340af | 905 | linux_target->low_new_thread (lp); |
9f0bdab8 | 906 | |
d6b0e80f AC |
907 | return lp; |
908 | } | |
909 | ||
910 | /* Remove the LWP specified by PID from the list. */ | |
911 | ||
912 | static void | |
913 | delete_lwp (ptid_t ptid) | |
914 | { | |
774113b0 PA |
915 | struct lwp_info *lp; |
916 | void **slot; | |
917 | struct lwp_info dummy; | |
d6b0e80f | 918 | |
774113b0 PA |
919 | dummy.ptid = ptid; |
920 | slot = htab_find_slot (lwp_lwpid_htab, &dummy, NO_INSERT); | |
921 | if (slot == NULL) | |
922 | return; | |
d6b0e80f | 923 | |
774113b0 PA |
924 | lp = *(struct lwp_info **) slot; |
925 | gdb_assert (lp != NULL); | |
d6b0e80f | 926 | |
774113b0 | 927 | htab_clear_slot (lwp_lwpid_htab, slot); |
d6b0e80f | 928 | |
774113b0 PA |
929 | /* Remove from sorted-by-creation-order list. */ |
930 | lwp_list_remove (lp); | |
d6b0e80f | 931 | |
774113b0 | 932 | /* Release. */ |
7b50312a | 933 | lwp_free (lp); |
d6b0e80f AC |
934 | } |
935 | ||
936 | /* Return a pointer to the structure describing the LWP corresponding | |
937 | to PID. If no corresponding LWP could be found, return NULL. */ | |
938 | ||
939 | static struct lwp_info * | |
940 | find_lwp_pid (ptid_t ptid) | |
941 | { | |
942 | struct lwp_info *lp; | |
943 | int lwp; | |
774113b0 | 944 | struct lwp_info dummy; |
d6b0e80f | 945 | |
15a9e13e | 946 | if (ptid.lwp_p ()) |
e38504b3 | 947 | lwp = ptid.lwp (); |
d6b0e80f | 948 | else |
e99b03dc | 949 | lwp = ptid.pid (); |
d6b0e80f | 950 | |
fd79271b | 951 | dummy.ptid = ptid_t (0, lwp, 0); |
774113b0 PA |
952 | lp = (struct lwp_info *) htab_find (lwp_lwpid_htab, &dummy); |
953 | return lp; | |
d6b0e80f AC |
954 | } |
955 | ||
6d4ee8c6 | 956 | /* See nat/linux-nat.h. */ |
d6b0e80f AC |
957 | |
958 | struct lwp_info * | |
d90e17a7 | 959 | iterate_over_lwps (ptid_t filter, |
d3a70e03 | 960 | gdb::function_view<iterate_over_lwps_ftype> callback) |
d6b0e80f AC |
961 | { |
962 | struct lwp_info *lp, *lpnext; | |
963 | ||
964 | for (lp = lwp_list; lp; lp = lpnext) | |
965 | { | |
966 | lpnext = lp->next; | |
d90e17a7 | 967 | |
26a57c92 | 968 | if (lp->ptid.matches (filter)) |
d90e17a7 | 969 | { |
d3a70e03 | 970 | if (callback (lp) != 0) |
d90e17a7 PA |
971 | return lp; |
972 | } | |
d6b0e80f AC |
973 | } |
974 | ||
975 | return NULL; | |
976 | } | |
977 | ||
2277426b PA |
978 | /* Update our internal state when changing from one checkpoint to |
979 | another indicated by NEW_PTID. We can only switch single-threaded | |
980 | applications, so we only create one new LWP, and the previous list | |
981 | is discarded. */ | |
f973ed9c DJ |
982 | |
983 | void | |
984 | linux_nat_switch_fork (ptid_t new_ptid) | |
985 | { | |
986 | struct lwp_info *lp; | |
987 | ||
e99b03dc | 988 | purge_lwp_list (inferior_ptid.pid ()); |
2277426b | 989 | |
f973ed9c DJ |
990 | lp = add_lwp (new_ptid); |
991 | lp->stopped = 1; | |
e26af52f | 992 | |
2277426b PA |
993 | /* This changes the thread's ptid while preserving the gdb thread |
994 | num. Also changes the inferior pid, while preserving the | |
995 | inferior num. */ | |
5b6d1e4f | 996 | thread_change_ptid (linux_target, inferior_ptid, new_ptid); |
2277426b PA |
997 | |
998 | /* We've just told GDB core that the thread changed target id, but, | |
999 | in fact, it really is a different thread, with different register | |
1000 | contents. */ | |
1001 | registers_changed (); | |
e26af52f DJ |
1002 | } |
1003 | ||
e26af52f DJ |
1004 | /* Handle the exit of a single thread LP. */ |
1005 | ||
1006 | static void | |
1007 | exit_lwp (struct lwp_info *lp) | |
1008 | { | |
5b6d1e4f | 1009 | struct thread_info *th = find_thread_ptid (linux_target, lp->ptid); |
063bfe2e VP |
1010 | |
1011 | if (th) | |
e26af52f | 1012 | { |
17faa917 | 1013 | if (print_thread_events) |
a068643d TT |
1014 | printf_unfiltered (_("[%s exited]\n"), |
1015 | target_pid_to_str (lp->ptid).c_str ()); | |
17faa917 | 1016 | |
00431a78 | 1017 | delete_thread (th); |
e26af52f DJ |
1018 | } |
1019 | ||
1020 | delete_lwp (lp->ptid); | |
1021 | } | |
1022 | ||
a0ef4274 DJ |
1023 | /* Wait for the LWP specified by LP, which we have just attached to. |
1024 | Returns a wait status for that LWP, to cache. */ | |
1025 | ||
1026 | static int | |
22827c51 | 1027 | linux_nat_post_attach_wait (ptid_t ptid, int *signalled) |
a0ef4274 | 1028 | { |
e38504b3 | 1029 | pid_t new_pid, pid = ptid.lwp (); |
a0ef4274 DJ |
1030 | int status; |
1031 | ||
644cebc9 | 1032 | if (linux_proc_pid_is_stopped (pid)) |
a0ef4274 | 1033 | { |
9327494e | 1034 | linux_nat_debug_printf ("Attaching to a stopped process"); |
a0ef4274 DJ |
1035 | |
1036 | /* The process is definitely stopped. It is in a job control | |
1037 | stop, unless the kernel predates the TASK_STOPPED / | |
1038 | TASK_TRACED distinction, in which case it might be in a | |
1039 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
1040 | can kill it, signal it, et cetera. | |
1041 | ||
dda83cd7 | 1042 | First make sure there is a pending SIGSTOP. Since we are |
a0ef4274 DJ |
1043 | already attached, the process can not transition from stopped |
1044 | to running without a PTRACE_CONT; so we know this signal will | |
1045 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
1046 | probably already in the queue (unless this kernel is old | |
1047 | enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP | |
1048 | is not an RT signal, it can only be queued once. */ | |
1049 | kill_lwp (pid, SIGSTOP); | |
1050 | ||
1051 | /* Finally, resume the stopped process. This will deliver the SIGSTOP | |
1052 | (or a higher priority signal, just like normal PTRACE_ATTACH). */ | |
1053 | ptrace (PTRACE_CONT, pid, 0, 0); | |
1054 | } | |
1055 | ||
1056 | /* Make sure the initial process is stopped. The user-level threads | |
1057 | layer might want to poke around in the inferior, and that won't | |
1058 | work if things haven't stabilized yet. */ | |
4a6ed09b | 1059 | new_pid = my_waitpid (pid, &status, __WALL); |
dacc9cb2 PP |
1060 | gdb_assert (pid == new_pid); |
1061 | ||
1062 | if (!WIFSTOPPED (status)) | |
1063 | { | |
1064 | /* The pid we tried to attach has apparently just exited. */ | |
9327494e | 1065 | linux_nat_debug_printf ("Failed to stop %d: %s", pid, |
8d06918f | 1066 | status_to_str (status).c_str ()); |
dacc9cb2 PP |
1067 | return status; |
1068 | } | |
a0ef4274 DJ |
1069 | |
1070 | if (WSTOPSIG (status) != SIGSTOP) | |
1071 | { | |
1072 | *signalled = 1; | |
9327494e | 1073 | linux_nat_debug_printf ("Received %s after attaching", |
8d06918f | 1074 | status_to_str (status).c_str ()); |
a0ef4274 DJ |
1075 | } |
1076 | ||
1077 | return status; | |
1078 | } | |
1079 | ||
f6ac5f3d PA |
1080 | void |
1081 | linux_nat_target::create_inferior (const char *exec_file, | |
1082 | const std::string &allargs, | |
1083 | char **env, int from_tty) | |
b84876c2 | 1084 | { |
41272101 TT |
1085 | maybe_disable_address_space_randomization restore_personality |
1086 | (disable_randomization); | |
b84876c2 PA |
1087 | |
1088 | /* The fork_child mechanism is synchronous and calls target_wait, so | |
1089 | we have to mask the async mode. */ | |
1090 | ||
2455069d | 1091 | /* Make sure we report all signals during startup. */ |
adc6a863 | 1092 | pass_signals ({}); |
2455069d | 1093 | |
f6ac5f3d | 1094 | inf_ptrace_target::create_inferior (exec_file, allargs, env, from_tty); |
b84876c2 PA |
1095 | } |
1096 | ||
8784d563 PA |
1097 | /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not |
1098 | already attached. Returns true if a new LWP is found, false | |
1099 | otherwise. */ | |
1100 | ||
1101 | static int | |
1102 | attach_proc_task_lwp_callback (ptid_t ptid) | |
1103 | { | |
1104 | struct lwp_info *lp; | |
1105 | ||
1106 | /* Ignore LWPs we're already attached to. */ | |
1107 | lp = find_lwp_pid (ptid); | |
1108 | if (lp == NULL) | |
1109 | { | |
e38504b3 | 1110 | int lwpid = ptid.lwp (); |
8784d563 PA |
1111 | |
1112 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) | |
1113 | { | |
1114 | int err = errno; | |
1115 | ||
1116 | /* Be quiet if we simply raced with the thread exiting. | |
1117 | EPERM is returned if the thread's task still exists, and | |
1118 | is marked as exited or zombie, as well as other | |
1119 | conditions, so in that case, confirm the status in | |
1120 | /proc/PID/status. */ | |
1121 | if (err == ESRCH | |
1122 | || (err == EPERM && linux_proc_pid_is_gone (lwpid))) | |
1123 | { | |
9327494e SM |
1124 | linux_nat_debug_printf |
1125 | ("Cannot attach to lwp %d: thread is gone (%d: %s)", | |
1126 | lwpid, err, safe_strerror (err)); | |
1127 | ||
8784d563 PA |
1128 | } |
1129 | else | |
1130 | { | |
4d9b86e1 | 1131 | std::string reason |
50fa3001 | 1132 | = linux_ptrace_attach_fail_reason_string (ptid, err); |
4d9b86e1 | 1133 | |
f71f0b0d | 1134 | warning (_("Cannot attach to lwp %d: %s"), |
4d9b86e1 | 1135 | lwpid, reason.c_str ()); |
8784d563 PA |
1136 | } |
1137 | } | |
1138 | else | |
1139 | { | |
9327494e SM |
1140 | linux_nat_debug_printf ("PTRACE_ATTACH %s, 0, 0 (OK)", |
1141 | target_pid_to_str (ptid).c_str ()); | |
8784d563 PA |
1142 | |
1143 | lp = add_lwp (ptid); | |
8784d563 PA |
1144 | |
1145 | /* The next time we wait for this LWP we'll see a SIGSTOP as | |
1146 | PTRACE_ATTACH brings it to a halt. */ | |
1147 | lp->signalled = 1; | |
1148 | ||
1149 | /* We need to wait for a stop before being able to make the | |
1150 | next ptrace call on this LWP. */ | |
1151 | lp->must_set_ptrace_flags = 1; | |
026a9174 PA |
1152 | |
1153 | /* So that wait collects the SIGSTOP. */ | |
1154 | lp->resumed = 1; | |
1155 | ||
1156 | /* Also add the LWP to gdb's thread list, in case a | |
1157 | matching libthread_db is not found (or the process uses | |
1158 | raw clone). */ | |
5b6d1e4f | 1159 | add_thread (linux_target, lp->ptid); |
719546c4 SM |
1160 | set_running (linux_target, lp->ptid, true); |
1161 | set_executing (linux_target, lp->ptid, true); | |
8784d563 PA |
1162 | } |
1163 | ||
1164 | return 1; | |
1165 | } | |
1166 | return 0; | |
1167 | } | |
1168 | ||
f6ac5f3d PA |
1169 | void |
1170 | linux_nat_target::attach (const char *args, int from_tty) | |
d6b0e80f AC |
1171 | { |
1172 | struct lwp_info *lp; | |
d6b0e80f | 1173 | int status; |
af990527 | 1174 | ptid_t ptid; |
d6b0e80f | 1175 | |
2455069d | 1176 | /* Make sure we report all signals during attach. */ |
adc6a863 | 1177 | pass_signals ({}); |
2455069d | 1178 | |
a70b8144 | 1179 | try |
87b0bb13 | 1180 | { |
f6ac5f3d | 1181 | inf_ptrace_target::attach (args, from_tty); |
87b0bb13 | 1182 | } |
230d2906 | 1183 | catch (const gdb_exception_error &ex) |
87b0bb13 JK |
1184 | { |
1185 | pid_t pid = parse_pid_to_attach (args); | |
50fa3001 | 1186 | std::string reason = linux_ptrace_attach_fail_reason (pid); |
87b0bb13 | 1187 | |
4d9b86e1 | 1188 | if (!reason.empty ()) |
3d6e9d23 TT |
1189 | throw_error (ex.error, "warning: %s\n%s", reason.c_str (), |
1190 | ex.what ()); | |
7ae1a6a6 | 1191 | else |
3d6e9d23 | 1192 | throw_error (ex.error, "%s", ex.what ()); |
87b0bb13 | 1193 | } |
d6b0e80f | 1194 | |
af990527 PA |
1195 | /* The ptrace base target adds the main thread with (pid,0,0) |
1196 | format. Decorate it with lwp info. */ | |
e99b03dc TT |
1197 | ptid = ptid_t (inferior_ptid.pid (), |
1198 | inferior_ptid.pid (), | |
fd79271b | 1199 | 0); |
5b6d1e4f | 1200 | thread_change_ptid (linux_target, inferior_ptid, ptid); |
af990527 | 1201 | |
9f0bdab8 | 1202 | /* Add the initial process as the first LWP to the list. */ |
26cb8b7c | 1203 | lp = add_initial_lwp (ptid); |
a0ef4274 | 1204 | |
22827c51 | 1205 | status = linux_nat_post_attach_wait (lp->ptid, &lp->signalled); |
dacc9cb2 PP |
1206 | if (!WIFSTOPPED (status)) |
1207 | { | |
1208 | if (WIFEXITED (status)) | |
1209 | { | |
1210 | int exit_code = WEXITSTATUS (status); | |
1211 | ||
223ffa71 | 1212 | target_terminal::ours (); |
bc1e6c81 | 1213 | target_mourn_inferior (inferior_ptid); |
dacc9cb2 PP |
1214 | if (exit_code == 0) |
1215 | error (_("Unable to attach: program exited normally.")); | |
1216 | else | |
1217 | error (_("Unable to attach: program exited with code %d."), | |
1218 | exit_code); | |
1219 | } | |
1220 | else if (WIFSIGNALED (status)) | |
1221 | { | |
2ea28649 | 1222 | enum gdb_signal signo; |
dacc9cb2 | 1223 | |
223ffa71 | 1224 | target_terminal::ours (); |
bc1e6c81 | 1225 | target_mourn_inferior (inferior_ptid); |
dacc9cb2 | 1226 | |
2ea28649 | 1227 | signo = gdb_signal_from_host (WTERMSIG (status)); |
dacc9cb2 PP |
1228 | error (_("Unable to attach: program terminated with signal " |
1229 | "%s, %s."), | |
2ea28649 PA |
1230 | gdb_signal_to_name (signo), |
1231 | gdb_signal_to_string (signo)); | |
dacc9cb2 PP |
1232 | } |
1233 | ||
1234 | internal_error (__FILE__, __LINE__, | |
1235 | _("unexpected status %d for PID %ld"), | |
e38504b3 | 1236 | status, (long) ptid.lwp ()); |
dacc9cb2 PP |
1237 | } |
1238 | ||
a0ef4274 | 1239 | lp->stopped = 1; |
9f0bdab8 | 1240 | |
a0ef4274 | 1241 | /* Save the wait status to report later. */ |
d6b0e80f | 1242 | lp->resumed = 1; |
9327494e | 1243 | linux_nat_debug_printf ("waitpid %ld, saving status %s", |
8d06918f SM |
1244 | (long) lp->ptid.pid (), |
1245 | status_to_str (status).c_str ()); | |
710151dd | 1246 | |
7feb7d06 PA |
1247 | lp->status = status; |
1248 | ||
8784d563 PA |
1249 | /* We must attach to every LWP. If /proc is mounted, use that to |
1250 | find them now. The inferior may be using raw clone instead of | |
1251 | using pthreads. But even if it is using pthreads, thread_db | |
1252 | walks structures in the inferior's address space to find the list | |
1253 | of threads/LWPs, and those structures may well be corrupted. | |
1254 | Note that once thread_db is loaded, we'll still use it to list | |
1255 | threads and associate pthread info with each LWP. */ | |
e99b03dc | 1256 | linux_proc_attach_tgid_threads (lp->ptid.pid (), |
8784d563 PA |
1257 | attach_proc_task_lwp_callback); |
1258 | ||
7feb7d06 | 1259 | if (target_can_async_p ()) |
6a3753b3 | 1260 | target_async (1); |
d6b0e80f AC |
1261 | } |
1262 | ||
ced2dffb PA |
1263 | /* Get pending signal of THREAD as a host signal number, for detaching |
1264 | purposes. This is the signal the thread last stopped for, which we | |
1265 | need to deliver to the thread when detaching, otherwise, it'd be | |
1266 | suppressed/lost. */ | |
1267 | ||
a0ef4274 | 1268 | static int |
ced2dffb | 1269 | get_detach_signal (struct lwp_info *lp) |
a0ef4274 | 1270 | { |
a493e3e2 | 1271 | enum gdb_signal signo = GDB_SIGNAL_0; |
ca2163eb PA |
1272 | |
1273 | /* If we paused threads momentarily, we may have stored pending | |
1274 | events in lp->status or lp->waitstatus (see stop_wait_callback), | |
1275 | and GDB core hasn't seen any signal for those threads. | |
1276 | Otherwise, the last signal reported to the core is found in the | |
1277 | thread object's stop_signal. | |
1278 | ||
1279 | There's a corner case that isn't handled here at present. Only | |
1280 | if the thread stopped with a TARGET_WAITKIND_STOPPED does | |
1281 | stop_signal make sense as a real signal to pass to the inferior. | |
1282 | Some catchpoint related events, like | |
1283 | TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set | |
a493e3e2 | 1284 | to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But, |
ca2163eb PA |
1285 | those traps are debug API (ptrace in our case) related and |
1286 | induced; the inferior wouldn't see them if it wasn't being | |
1287 | traced. Hence, we should never pass them to the inferior, even | |
1288 | when set to pass state. Since this corner case isn't handled by | |
1289 | infrun.c when proceeding with a signal, for consistency, neither | |
1290 | do we handle it here (or elsewhere in the file we check for | |
1291 | signal pass state). Normally SIGTRAP isn't set to pass state, so | |
1292 | this is really a corner case. */ | |
1293 | ||
1294 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
a493e3e2 | 1295 | signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */ |
ca2163eb | 1296 | else if (lp->status) |
2ea28649 | 1297 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
00431a78 | 1298 | else |
ca2163eb | 1299 | { |
5b6d1e4f | 1300 | struct thread_info *tp = find_thread_ptid (linux_target, lp->ptid); |
e0881a8e | 1301 | |
00431a78 | 1302 | if (target_is_non_stop_p () && !tp->executing) |
ca2163eb | 1303 | { |
00431a78 PA |
1304 | if (tp->suspend.waitstatus_pending_p) |
1305 | signo = tp->suspend.waitstatus.value.sig; | |
1306 | else | |
1307 | signo = tp->suspend.stop_signal; | |
1308 | } | |
1309 | else if (!target_is_non_stop_p ()) | |
1310 | { | |
00431a78 | 1311 | ptid_t last_ptid; |
5b6d1e4f | 1312 | process_stratum_target *last_target; |
00431a78 | 1313 | |
5b6d1e4f | 1314 | get_last_target_status (&last_target, &last_ptid, nullptr); |
e0881a8e | 1315 | |
5b6d1e4f PA |
1316 | if (last_target == linux_target |
1317 | && lp->ptid.lwp () == last_ptid.lwp ()) | |
00431a78 | 1318 | signo = tp->suspend.stop_signal; |
4c28f408 | 1319 | } |
ca2163eb | 1320 | } |
4c28f408 | 1321 | |
a493e3e2 | 1322 | if (signo == GDB_SIGNAL_0) |
ca2163eb | 1323 | { |
9327494e SM |
1324 | linux_nat_debug_printf ("lwp %s has no pending signal", |
1325 | target_pid_to_str (lp->ptid).c_str ()); | |
ca2163eb PA |
1326 | } |
1327 | else if (!signal_pass_state (signo)) | |
1328 | { | |
9327494e SM |
1329 | linux_nat_debug_printf |
1330 | ("lwp %s had signal %s but it is in no pass state", | |
1331 | target_pid_to_str (lp->ptid).c_str (), gdb_signal_to_string (signo)); | |
a0ef4274 | 1332 | } |
a0ef4274 | 1333 | else |
4c28f408 | 1334 | { |
9327494e SM |
1335 | linux_nat_debug_printf ("lwp %s has pending signal %s", |
1336 | target_pid_to_str (lp->ptid).c_str (), | |
1337 | gdb_signal_to_string (signo)); | |
ced2dffb PA |
1338 | |
1339 | return gdb_signal_to_host (signo); | |
4c28f408 | 1340 | } |
a0ef4274 DJ |
1341 | |
1342 | return 0; | |
1343 | } | |
1344 | ||
ced2dffb PA |
1345 | /* Detach from LP. If SIGNO_P is non-NULL, then it points to the |
1346 | signal number that should be passed to the LWP when detaching. | |
1347 | Otherwise pass any pending signal the LWP may have, if any. */ | |
1348 | ||
1349 | static void | |
1350 | detach_one_lwp (struct lwp_info *lp, int *signo_p) | |
d6b0e80f | 1351 | { |
e38504b3 | 1352 | int lwpid = lp->ptid.lwp (); |
ced2dffb PA |
1353 | int signo; |
1354 | ||
d6b0e80f AC |
1355 | gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status)); |
1356 | ||
9327494e SM |
1357 | if (lp->status != 0) |
1358 | linux_nat_debug_printf ("Pending %s for %s on detach.", | |
1359 | strsignal (WSTOPSIG (lp->status)), | |
1360 | target_pid_to_str (lp->ptid).c_str ()); | |
d6b0e80f | 1361 | |
a0ef4274 DJ |
1362 | /* If there is a pending SIGSTOP, get rid of it. */ |
1363 | if (lp->signalled) | |
d6b0e80f | 1364 | { |
9327494e SM |
1365 | linux_nat_debug_printf ("Sending SIGCONT to %s", |
1366 | target_pid_to_str (lp->ptid).c_str ()); | |
d6b0e80f | 1367 | |
ced2dffb | 1368 | kill_lwp (lwpid, SIGCONT); |
d6b0e80f | 1369 | lp->signalled = 0; |
d6b0e80f AC |
1370 | } |
1371 | ||
ced2dffb | 1372 | if (signo_p == NULL) |
d6b0e80f | 1373 | { |
a0ef4274 | 1374 | /* Pass on any pending signal for this LWP. */ |
ced2dffb PA |
1375 | signo = get_detach_signal (lp); |
1376 | } | |
1377 | else | |
1378 | signo = *signo_p; | |
a0ef4274 | 1379 | |
ced2dffb PA |
1380 | /* Preparing to resume may try to write registers, and fail if the |
1381 | lwp is zombie. If that happens, ignore the error. We'll handle | |
1382 | it below, when detach fails with ESRCH. */ | |
a70b8144 | 1383 | try |
ced2dffb | 1384 | { |
135340af | 1385 | linux_target->low_prepare_to_resume (lp); |
ced2dffb | 1386 | } |
230d2906 | 1387 | catch (const gdb_exception_error &ex) |
ced2dffb PA |
1388 | { |
1389 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 1390 | throw; |
ced2dffb | 1391 | } |
d6b0e80f | 1392 | |
ced2dffb PA |
1393 | if (ptrace (PTRACE_DETACH, lwpid, 0, signo) < 0) |
1394 | { | |
1395 | int save_errno = errno; | |
1396 | ||
1397 | /* We know the thread exists, so ESRCH must mean the lwp is | |
1398 | zombie. This can happen if one of the already-detached | |
1399 | threads exits the whole thread group. In that case we're | |
1400 | still attached, and must reap the lwp. */ | |
1401 | if (save_errno == ESRCH) | |
1402 | { | |
1403 | int ret, status; | |
d6b0e80f | 1404 | |
ced2dffb PA |
1405 | ret = my_waitpid (lwpid, &status, __WALL); |
1406 | if (ret == -1) | |
1407 | { | |
1408 | warning (_("Couldn't reap LWP %d while detaching: %s"), | |
6d91ce9a | 1409 | lwpid, safe_strerror (errno)); |
ced2dffb PA |
1410 | } |
1411 | else if (!WIFEXITED (status) && !WIFSIGNALED (status)) | |
1412 | { | |
1413 | warning (_("Reaping LWP %d while detaching " | |
1414 | "returned unexpected status 0x%x"), | |
1415 | lwpid, status); | |
1416 | } | |
1417 | } | |
1418 | else | |
1419 | { | |
a068643d TT |
1420 | error (_("Can't detach %s: %s"), |
1421 | target_pid_to_str (lp->ptid).c_str (), | |
ced2dffb PA |
1422 | safe_strerror (save_errno)); |
1423 | } | |
d6b0e80f | 1424 | } |
9327494e SM |
1425 | else |
1426 | linux_nat_debug_printf ("PTRACE_DETACH (%s, %s, 0) (OK)", | |
1427 | target_pid_to_str (lp->ptid).c_str (), | |
1428 | strsignal (signo)); | |
ced2dffb PA |
1429 | |
1430 | delete_lwp (lp->ptid); | |
1431 | } | |
d6b0e80f | 1432 | |
ced2dffb | 1433 | static int |
d3a70e03 | 1434 | detach_callback (struct lwp_info *lp) |
ced2dffb PA |
1435 | { |
1436 | /* We don't actually detach from the thread group leader just yet. | |
1437 | If the thread group exits, we must reap the zombie clone lwps | |
1438 | before we're able to reap the leader. */ | |
e38504b3 | 1439 | if (lp->ptid.lwp () != lp->ptid.pid ()) |
ced2dffb | 1440 | detach_one_lwp (lp, NULL); |
d6b0e80f AC |
1441 | return 0; |
1442 | } | |
1443 | ||
f6ac5f3d PA |
1444 | void |
1445 | linux_nat_target::detach (inferior *inf, int from_tty) | |
d6b0e80f | 1446 | { |
d90e17a7 | 1447 | struct lwp_info *main_lwp; |
bc09b0c1 | 1448 | int pid = inf->pid; |
a0ef4274 | 1449 | |
ae5e0686 MK |
1450 | /* Don't unregister from the event loop, as there may be other |
1451 | inferiors running. */ | |
b84876c2 | 1452 | |
4c28f408 | 1453 | /* Stop all threads before detaching. ptrace requires that the |
30baf67b | 1454 | thread is stopped to successfully detach. */ |
d3a70e03 | 1455 | iterate_over_lwps (ptid_t (pid), stop_callback); |
4c28f408 PA |
1456 | /* ... and wait until all of them have reported back that |
1457 | they're no longer running. */ | |
d3a70e03 | 1458 | iterate_over_lwps (ptid_t (pid), stop_wait_callback); |
4c28f408 | 1459 | |
e87f0fe8 PA |
1460 | /* We can now safely remove breakpoints. We don't this in earlier |
1461 | in common code because this target doesn't currently support | |
1462 | writing memory while the inferior is running. */ | |
1463 | remove_breakpoints_inf (current_inferior ()); | |
1464 | ||
d3a70e03 | 1465 | iterate_over_lwps (ptid_t (pid), detach_callback); |
d6b0e80f AC |
1466 | |
1467 | /* Only the initial process should be left right now. */ | |
bc09b0c1 | 1468 | gdb_assert (num_lwps (pid) == 1); |
d90e17a7 | 1469 | |
f2907e49 | 1470 | main_lwp = find_lwp_pid (ptid_t (pid)); |
d6b0e80f | 1471 | |
7a7d3353 PA |
1472 | if (forks_exist_p ()) |
1473 | { | |
1474 | /* Multi-fork case. The current inferior_ptid is being detached | |
1475 | from, but there are other viable forks to debug. Detach from | |
1476 | the current fork, and context-switch to the first | |
1477 | available. */ | |
6bd6f3b6 | 1478 | linux_fork_detach (from_tty); |
7a7d3353 PA |
1479 | } |
1480 | else | |
ced2dffb | 1481 | { |
ced2dffb PA |
1482 | target_announce_detach (from_tty); |
1483 | ||
6bd6f3b6 SM |
1484 | /* Pass on any pending signal for the last LWP. */ |
1485 | int signo = get_detach_signal (main_lwp); | |
ced2dffb PA |
1486 | |
1487 | detach_one_lwp (main_lwp, &signo); | |
1488 | ||
f6ac5f3d | 1489 | detach_success (inf); |
ced2dffb | 1490 | } |
05c06f31 PA |
1491 | |
1492 | maybe_close_proc_mem_file (pid); | |
d6b0e80f AC |
1493 | } |
1494 | ||
8a99810d PA |
1495 | /* Resume execution of the inferior process. If STEP is nonzero, |
1496 | single-step it. If SIGNAL is nonzero, give it that signal. */ | |
1497 | ||
1498 | static void | |
23f238d3 PA |
1499 | linux_resume_one_lwp_throw (struct lwp_info *lp, int step, |
1500 | enum gdb_signal signo) | |
8a99810d | 1501 | { |
8a99810d | 1502 | lp->step = step; |
9c02b525 PA |
1503 | |
1504 | /* stop_pc doubles as the PC the LWP had when it was last resumed. | |
1505 | We only presently need that if the LWP is stepped though (to | |
1506 | handle the case of stepping a breakpoint instruction). */ | |
1507 | if (step) | |
1508 | { | |
5b6d1e4f | 1509 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
9c02b525 PA |
1510 | |
1511 | lp->stop_pc = regcache_read_pc (regcache); | |
1512 | } | |
1513 | else | |
1514 | lp->stop_pc = 0; | |
1515 | ||
135340af | 1516 | linux_target->low_prepare_to_resume (lp); |
f6ac5f3d | 1517 | linux_target->low_resume (lp->ptid, step, signo); |
23f238d3 PA |
1518 | |
1519 | /* Successfully resumed. Clear state that no longer makes sense, | |
1520 | and mark the LWP as running. Must not do this before resuming | |
1521 | otherwise if that fails other code will be confused. E.g., we'd | |
1522 | later try to stop the LWP and hang forever waiting for a stop | |
1523 | status. Note that we must not throw after this is cleared, | |
1524 | otherwise handle_zombie_lwp_error would get confused. */ | |
8a99810d | 1525 | lp->stopped = 0; |
1ad3de98 | 1526 | lp->core = -1; |
23f238d3 | 1527 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; |
5b6d1e4f | 1528 | registers_changed_ptid (linux_target, lp->ptid); |
8a99810d PA |
1529 | } |
1530 | ||
23f238d3 PA |
1531 | /* Called when we try to resume a stopped LWP and that errors out. If |
1532 | the LWP is no longer in ptrace-stopped state (meaning it's zombie, | |
1533 | or about to become), discard the error, clear any pending status | |
1534 | the LWP may have, and return true (we'll collect the exit status | |
1535 | soon enough). Otherwise, return false. */ | |
1536 | ||
1537 | static int | |
1538 | check_ptrace_stopped_lwp_gone (struct lwp_info *lp) | |
1539 | { | |
1540 | /* If we get an error after resuming the LWP successfully, we'd | |
1541 | confuse !T state for the LWP being gone. */ | |
1542 | gdb_assert (lp->stopped); | |
1543 | ||
1544 | /* We can't just check whether the LWP is in 'Z (Zombie)' state, | |
1545 | because even if ptrace failed with ESRCH, the tracee may be "not | |
1546 | yet fully dead", but already refusing ptrace requests. In that | |
1547 | case the tracee has 'R (Running)' state for a little bit | |
1548 | (observed in Linux 3.18). See also the note on ESRCH in the | |
1549 | ptrace(2) man page. Instead, check whether the LWP has any state | |
1550 | other than ptrace-stopped. */ | |
1551 | ||
1552 | /* Don't assume anything if /proc/PID/status can't be read. */ | |
e38504b3 | 1553 | if (linux_proc_pid_is_trace_stopped_nowarn (lp->ptid.lwp ()) == 0) |
23f238d3 PA |
1554 | { |
1555 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; | |
1556 | lp->status = 0; | |
1557 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
1558 | return 1; | |
1559 | } | |
1560 | return 0; | |
1561 | } | |
1562 | ||
1563 | /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP | |
1564 | disappears while we try to resume it. */ | |
1565 | ||
1566 | static void | |
1567 | linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) | |
1568 | { | |
a70b8144 | 1569 | try |
23f238d3 PA |
1570 | { |
1571 | linux_resume_one_lwp_throw (lp, step, signo); | |
1572 | } | |
230d2906 | 1573 | catch (const gdb_exception_error &ex) |
23f238d3 PA |
1574 | { |
1575 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 1576 | throw; |
23f238d3 | 1577 | } |
23f238d3 PA |
1578 | } |
1579 | ||
d6b0e80f AC |
1580 | /* Resume LP. */ |
1581 | ||
25289eb2 | 1582 | static void |
e5ef252a | 1583 | resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) |
d6b0e80f | 1584 | { |
25289eb2 | 1585 | if (lp->stopped) |
6c95b8df | 1586 | { |
5b6d1e4f | 1587 | struct inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
25289eb2 PA |
1588 | |
1589 | if (inf->vfork_child != NULL) | |
1590 | { | |
9327494e SM |
1591 | linux_nat_debug_printf ("Not resuming %s (vfork parent)", |
1592 | target_pid_to_str (lp->ptid).c_str ()); | |
25289eb2 | 1593 | } |
8a99810d | 1594 | else if (!lwp_status_pending_p (lp)) |
25289eb2 | 1595 | { |
9327494e SM |
1596 | linux_nat_debug_printf ("Resuming sibling %s, %s, %s", |
1597 | target_pid_to_str (lp->ptid).c_str (), | |
1598 | (signo != GDB_SIGNAL_0 | |
1599 | ? strsignal (gdb_signal_to_host (signo)) | |
1600 | : "0"), | |
1601 | step ? "step" : "resume"); | |
25289eb2 | 1602 | |
8a99810d | 1603 | linux_resume_one_lwp (lp, step, signo); |
25289eb2 PA |
1604 | } |
1605 | else | |
1606 | { | |
9327494e SM |
1607 | linux_nat_debug_printf ("Not resuming sibling %s (has pending)", |
1608 | target_pid_to_str (lp->ptid).c_str ()); | |
25289eb2 | 1609 | } |
6c95b8df | 1610 | } |
25289eb2 | 1611 | else |
9327494e | 1612 | linux_nat_debug_printf ("Not resuming sibling %s (not stopped)", |
a068643d | 1613 | target_pid_to_str (lp->ptid).c_str ()); |
25289eb2 | 1614 | } |
d6b0e80f | 1615 | |
8817a6f2 PA |
1616 | /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing. |
1617 | Resume LWP with the last stop signal, if it is in pass state. */ | |
e5ef252a | 1618 | |
25289eb2 | 1619 | static int |
d3a70e03 | 1620 | linux_nat_resume_callback (struct lwp_info *lp, struct lwp_info *except) |
25289eb2 | 1621 | { |
e5ef252a PA |
1622 | enum gdb_signal signo = GDB_SIGNAL_0; |
1623 | ||
8817a6f2 PA |
1624 | if (lp == except) |
1625 | return 0; | |
1626 | ||
e5ef252a PA |
1627 | if (lp->stopped) |
1628 | { | |
1629 | struct thread_info *thread; | |
1630 | ||
5b6d1e4f | 1631 | thread = find_thread_ptid (linux_target, lp->ptid); |
e5ef252a PA |
1632 | if (thread != NULL) |
1633 | { | |
70509625 | 1634 | signo = thread->suspend.stop_signal; |
e5ef252a PA |
1635 | thread->suspend.stop_signal = GDB_SIGNAL_0; |
1636 | } | |
1637 | } | |
1638 | ||
1639 | resume_lwp (lp, 0, signo); | |
d6b0e80f AC |
1640 | return 0; |
1641 | } | |
1642 | ||
1643 | static int | |
d3a70e03 | 1644 | resume_clear_callback (struct lwp_info *lp) |
d6b0e80f AC |
1645 | { |
1646 | lp->resumed = 0; | |
25289eb2 | 1647 | lp->last_resume_kind = resume_stop; |
d6b0e80f AC |
1648 | return 0; |
1649 | } | |
1650 | ||
1651 | static int | |
d3a70e03 | 1652 | resume_set_callback (struct lwp_info *lp) |
d6b0e80f AC |
1653 | { |
1654 | lp->resumed = 1; | |
25289eb2 | 1655 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1656 | return 0; |
1657 | } | |
1658 | ||
f6ac5f3d PA |
1659 | void |
1660 | linux_nat_target::resume (ptid_t ptid, int step, enum gdb_signal signo) | |
d6b0e80f AC |
1661 | { |
1662 | struct lwp_info *lp; | |
d90e17a7 | 1663 | int resume_many; |
d6b0e80f | 1664 | |
9327494e SM |
1665 | linux_nat_debug_printf ("Preparing to %s %s, %s, inferior_ptid %s", |
1666 | step ? "step" : "resume", | |
1667 | target_pid_to_str (ptid).c_str (), | |
1668 | (signo != GDB_SIGNAL_0 | |
1669 | ? strsignal (gdb_signal_to_host (signo)) : "0"), | |
1670 | target_pid_to_str (inferior_ptid).c_str ()); | |
76f50ad1 | 1671 | |
d6b0e80f | 1672 | /* A specific PTID means `step only this process id'. */ |
d7e15655 | 1673 | resume_many = (minus_one_ptid == ptid |
0e998d96 | 1674 | || ptid.is_pid ()); |
4c28f408 | 1675 | |
7da6a5b9 LM |
1676 | /* Mark the lwps we're resuming as resumed and update their |
1677 | last_resume_kind to resume_continue. */ | |
d3a70e03 | 1678 | iterate_over_lwps (ptid, resume_set_callback); |
d6b0e80f | 1679 | |
d90e17a7 PA |
1680 | /* See if it's the current inferior that should be handled |
1681 | specially. */ | |
1682 | if (resume_many) | |
1683 | lp = find_lwp_pid (inferior_ptid); | |
1684 | else | |
1685 | lp = find_lwp_pid (ptid); | |
9f0bdab8 | 1686 | gdb_assert (lp != NULL); |
d6b0e80f | 1687 | |
9f0bdab8 | 1688 | /* Remember if we're stepping. */ |
25289eb2 | 1689 | lp->last_resume_kind = step ? resume_step : resume_continue; |
d6b0e80f | 1690 | |
9f0bdab8 DJ |
1691 | /* If we have a pending wait status for this thread, there is no |
1692 | point in resuming the process. But first make sure that | |
1693 | linux_nat_wait won't preemptively handle the event - we | |
1694 | should never take this short-circuit if we are going to | |
1695 | leave LP running, since we have skipped resuming all the | |
1696 | other threads. This bit of code needs to be synchronized | |
1697 | with linux_nat_wait. */ | |
76f50ad1 | 1698 | |
9f0bdab8 DJ |
1699 | if (lp->status && WIFSTOPPED (lp->status)) |
1700 | { | |
2455069d UW |
1701 | if (!lp->step |
1702 | && WSTOPSIG (lp->status) | |
1703 | && sigismember (&pass_mask, WSTOPSIG (lp->status))) | |
d6b0e80f | 1704 | { |
9327494e SM |
1705 | linux_nat_debug_printf |
1706 | ("Not short circuiting for ignored status 0x%x", lp->status); | |
9f0bdab8 | 1707 | |
d6b0e80f AC |
1708 | /* FIXME: What should we do if we are supposed to continue |
1709 | this thread with a signal? */ | |
a493e3e2 | 1710 | gdb_assert (signo == GDB_SIGNAL_0); |
2ea28649 | 1711 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
9f0bdab8 DJ |
1712 | lp->status = 0; |
1713 | } | |
1714 | } | |
76f50ad1 | 1715 | |
8a99810d | 1716 | if (lwp_status_pending_p (lp)) |
9f0bdab8 DJ |
1717 | { |
1718 | /* FIXME: What should we do if we are supposed to continue | |
1719 | this thread with a signal? */ | |
a493e3e2 | 1720 | gdb_assert (signo == GDB_SIGNAL_0); |
76f50ad1 | 1721 | |
9327494e SM |
1722 | linux_nat_debug_printf ("Short circuiting for status 0x%x", |
1723 | lp->status); | |
d6b0e80f | 1724 | |
7feb7d06 PA |
1725 | if (target_can_async_p ()) |
1726 | { | |
6a3753b3 | 1727 | target_async (1); |
7feb7d06 PA |
1728 | /* Tell the event loop we have something to process. */ |
1729 | async_file_mark (); | |
1730 | } | |
9f0bdab8 | 1731 | return; |
d6b0e80f AC |
1732 | } |
1733 | ||
d90e17a7 | 1734 | if (resume_many) |
d3a70e03 TT |
1735 | iterate_over_lwps (ptid, [=] (struct lwp_info *info) |
1736 | { | |
1737 | return linux_nat_resume_callback (info, lp); | |
1738 | }); | |
d90e17a7 | 1739 | |
9327494e SM |
1740 | linux_nat_debug_printf ("%s %s, %s (resume event thread)", |
1741 | step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
1742 | target_pid_to_str (lp->ptid).c_str (), | |
1743 | (signo != GDB_SIGNAL_0 | |
1744 | ? strsignal (gdb_signal_to_host (signo)) : "0")); | |
b84876c2 | 1745 | |
2bf6fb9d PA |
1746 | linux_resume_one_lwp (lp, step, signo); |
1747 | ||
b84876c2 | 1748 | if (target_can_async_p ()) |
6a3753b3 | 1749 | target_async (1); |
d6b0e80f AC |
1750 | } |
1751 | ||
c5f62d5f | 1752 | /* Send a signal to an LWP. */ |
d6b0e80f AC |
1753 | |
1754 | static int | |
1755 | kill_lwp (int lwpid, int signo) | |
1756 | { | |
4a6ed09b | 1757 | int ret; |
d6b0e80f | 1758 | |
4a6ed09b PA |
1759 | errno = 0; |
1760 | ret = syscall (__NR_tkill, lwpid, signo); | |
1761 | if (errno == ENOSYS) | |
1762 | { | |
1763 | /* If tkill fails, then we are not using nptl threads, a | |
1764 | configuration we no longer support. */ | |
1765 | perror_with_name (("tkill")); | |
1766 | } | |
1767 | return ret; | |
d6b0e80f AC |
1768 | } |
1769 | ||
ca2163eb PA |
1770 | /* Handle a GNU/Linux syscall trap wait response. If we see a syscall |
1771 | event, check if the core is interested in it: if not, ignore the | |
1772 | event, and keep waiting; otherwise, we need to toggle the LWP's | |
1773 | syscall entry/exit status, since the ptrace event itself doesn't | |
1774 | indicate it, and report the trap to higher layers. */ | |
1775 | ||
1776 | static int | |
1777 | linux_handle_syscall_trap (struct lwp_info *lp, int stopping) | |
1778 | { | |
1779 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
1780 | struct gdbarch *gdbarch = target_thread_architecture (lp->ptid); | |
5b6d1e4f | 1781 | thread_info *thread = find_thread_ptid (linux_target, lp->ptid); |
00431a78 | 1782 | int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, thread); |
ca2163eb PA |
1783 | |
1784 | if (stopping) | |
1785 | { | |
1786 | /* If we're stopping threads, there's a SIGSTOP pending, which | |
1787 | makes it so that the LWP reports an immediate syscall return, | |
1788 | followed by the SIGSTOP. Skip seeing that "return" using | |
1789 | PTRACE_CONT directly, and let stop_wait_callback collect the | |
1790 | SIGSTOP. Later when the thread is resumed, a new syscall | |
1791 | entry event. If we didn't do this (and returned 0), we'd | |
1792 | leave a syscall entry pending, and our caller, by using | |
1793 | PTRACE_CONT to collect the SIGSTOP, skips the syscall return | |
1794 | itself. Later, when the user re-resumes this LWP, we'd see | |
1795 | another syscall entry event and we'd mistake it for a return. | |
1796 | ||
1797 | If stop_wait_callback didn't force the SIGSTOP out of the LWP | |
1798 | (leaving immediately with LWP->signalled set, without issuing | |
1799 | a PTRACE_CONT), it would still be problematic to leave this | |
1800 | syscall enter pending, as later when the thread is resumed, | |
1801 | it would then see the same syscall exit mentioned above, | |
1802 | followed by the delayed SIGSTOP, while the syscall didn't | |
1803 | actually get to execute. It seems it would be even more | |
1804 | confusing to the user. */ | |
1805 | ||
9327494e SM |
1806 | linux_nat_debug_printf |
1807 | ("ignoring syscall %d for LWP %ld (stopping threads), resuming with " | |
1808 | "PTRACE_CONT for SIGSTOP", syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1809 | |
1810 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
e38504b3 | 1811 | ptrace (PTRACE_CONT, lp->ptid.lwp (), 0, 0); |
8817a6f2 | 1812 | lp->stopped = 0; |
ca2163eb PA |
1813 | return 1; |
1814 | } | |
1815 | ||
bfd09d20 JS |
1816 | /* Always update the entry/return state, even if this particular |
1817 | syscall isn't interesting to the core now. In async mode, | |
1818 | the user could install a new catchpoint for this syscall | |
1819 | between syscall enter/return, and we'll need to know to | |
1820 | report a syscall return if that happens. */ | |
1821 | lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1822 | ? TARGET_WAITKIND_SYSCALL_RETURN | |
1823 | : TARGET_WAITKIND_SYSCALL_ENTRY); | |
1824 | ||
ca2163eb PA |
1825 | if (catch_syscall_enabled ()) |
1826 | { | |
ca2163eb PA |
1827 | if (catching_syscall_number (syscall_number)) |
1828 | { | |
1829 | /* Alright, an event to report. */ | |
1830 | ourstatus->kind = lp->syscall_state; | |
1831 | ourstatus->value.syscall_number = syscall_number; | |
1832 | ||
9327494e SM |
1833 | linux_nat_debug_printf |
1834 | ("stopping for %s of syscall %d for LWP %ld", | |
1835 | (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1836 | ? "entry" : "return"), syscall_number, lp->ptid.lwp ()); | |
1837 | ||
ca2163eb PA |
1838 | return 0; |
1839 | } | |
1840 | ||
9327494e SM |
1841 | linux_nat_debug_printf |
1842 | ("ignoring %s of syscall %d for LWP %ld", | |
1843 | (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1844 | ? "entry" : "return"), syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1845 | } |
1846 | else | |
1847 | { | |
1848 | /* If we had been syscall tracing, and hence used PT_SYSCALL | |
1849 | before on this LWP, it could happen that the user removes all | |
1850 | syscall catchpoints before we get to process this event. | |
1851 | There are two noteworthy issues here: | |
1852 | ||
1853 | - When stopped at a syscall entry event, resuming with | |
1854 | PT_STEP still resumes executing the syscall and reports a | |
1855 | syscall return. | |
1856 | ||
1857 | - Only PT_SYSCALL catches syscall enters. If we last | |
1858 | single-stepped this thread, then this event can't be a | |
1859 | syscall enter. If we last single-stepped this thread, this | |
1860 | has to be a syscall exit. | |
1861 | ||
1862 | The points above mean that the next resume, be it PT_STEP or | |
1863 | PT_CONTINUE, can not trigger a syscall trace event. */ | |
9327494e SM |
1864 | linux_nat_debug_printf |
1865 | ("caught syscall event with no syscall catchpoints. %d for LWP %ld, " | |
1866 | "ignoring", syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1867 | lp->syscall_state = TARGET_WAITKIND_IGNORE; |
1868 | } | |
1869 | ||
1870 | /* The core isn't interested in this event. For efficiency, avoid | |
1871 | stopping all threads only to have the core resume them all again. | |
1872 | Since we're not stopping threads, if we're still syscall tracing | |
1873 | and not stepping, we can't use PTRACE_CONT here, as we'd miss any | |
1874 | subsequent syscall. Simply resume using the inf-ptrace layer, | |
1875 | which knows when to use PT_SYSCALL or PT_CONTINUE. */ | |
1876 | ||
8a99810d | 1877 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
ca2163eb PA |
1878 | return 1; |
1879 | } | |
1880 | ||
3d799a95 DJ |
1881 | /* Handle a GNU/Linux extended wait response. If we see a clone |
1882 | event, we need to add the new LWP to our list (and not report the | |
1883 | trap to higher layers). This function returns non-zero if the | |
1884 | event should be ignored and we should wait again. If STOPPING is | |
1885 | true, the new LWP remains stopped, otherwise it is continued. */ | |
d6b0e80f AC |
1886 | |
1887 | static int | |
4dd63d48 | 1888 | linux_handle_extended_wait (struct lwp_info *lp, int status) |
d6b0e80f | 1889 | { |
e38504b3 | 1890 | int pid = lp->ptid.lwp (); |
3d799a95 | 1891 | struct target_waitstatus *ourstatus = &lp->waitstatus; |
89a5711c | 1892 | int event = linux_ptrace_get_extended_event (status); |
d6b0e80f | 1893 | |
bfd09d20 JS |
1894 | /* All extended events we currently use are mid-syscall. Only |
1895 | PTRACE_EVENT_STOP is delivered more like a signal-stop, but | |
1896 | you have to be using PTRACE_SEIZE to get that. */ | |
1897 | lp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY; | |
1898 | ||
3d799a95 DJ |
1899 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
1900 | || event == PTRACE_EVENT_CLONE) | |
d6b0e80f | 1901 | { |
3d799a95 DJ |
1902 | unsigned long new_pid; |
1903 | int ret; | |
1904 | ||
1905 | ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); | |
6fc19103 | 1906 | |
3d799a95 DJ |
1907 | /* If we haven't already seen the new PID stop, wait for it now. */ |
1908 | if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
1909 | { | |
1910 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
1911 | hits the SIGSTOP, but we're already attached. */ | |
4a6ed09b | 1912 | ret = my_waitpid (new_pid, &status, __WALL); |
3d799a95 DJ |
1913 | if (ret == -1) |
1914 | perror_with_name (_("waiting for new child")); | |
1915 | else if (ret != new_pid) | |
1916 | internal_error (__FILE__, __LINE__, | |
1917 | _("wait returned unexpected PID %d"), ret); | |
1918 | else if (!WIFSTOPPED (status)) | |
1919 | internal_error (__FILE__, __LINE__, | |
1920 | _("wait returned unexpected status 0x%x"), status); | |
1921 | } | |
1922 | ||
fd79271b | 1923 | ourstatus->value.related_pid = ptid_t (new_pid, new_pid, 0); |
3d799a95 | 1924 | |
26cb8b7c PA |
1925 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) |
1926 | { | |
1927 | /* The arch-specific native code may need to know about new | |
1928 | forks even if those end up never mapped to an | |
1929 | inferior. */ | |
135340af | 1930 | linux_target->low_new_fork (lp, new_pid); |
26cb8b7c | 1931 | } |
1310c1b0 PFC |
1932 | else if (event == PTRACE_EVENT_CLONE) |
1933 | { | |
1934 | linux_target->low_new_clone (lp, new_pid); | |
1935 | } | |
26cb8b7c | 1936 | |
2277426b | 1937 | if (event == PTRACE_EVENT_FORK |
e99b03dc | 1938 | && linux_fork_checkpointing_p (lp->ptid.pid ())) |
2277426b | 1939 | { |
2277426b PA |
1940 | /* Handle checkpointing by linux-fork.c here as a special |
1941 | case. We don't want the follow-fork-mode or 'catch fork' | |
1942 | to interfere with this. */ | |
1943 | ||
1944 | /* This won't actually modify the breakpoint list, but will | |
1945 | physically remove the breakpoints from the child. */ | |
fd79271b | 1946 | detach_breakpoints (ptid_t (new_pid, new_pid, 0)); |
2277426b PA |
1947 | |
1948 | /* Retain child fork in ptrace (stopped) state. */ | |
14571dad MS |
1949 | if (!find_fork_pid (new_pid)) |
1950 | add_fork (new_pid); | |
2277426b PA |
1951 | |
1952 | /* Report as spurious, so that infrun doesn't want to follow | |
1953 | this fork. We're actually doing an infcall in | |
1954 | linux-fork.c. */ | |
1955 | ourstatus->kind = TARGET_WAITKIND_SPURIOUS; | |
2277426b PA |
1956 | |
1957 | /* Report the stop to the core. */ | |
1958 | return 0; | |
1959 | } | |
1960 | ||
3d799a95 DJ |
1961 | if (event == PTRACE_EVENT_FORK) |
1962 | ourstatus->kind = TARGET_WAITKIND_FORKED; | |
1963 | else if (event == PTRACE_EVENT_VFORK) | |
1964 | ourstatus->kind = TARGET_WAITKIND_VFORKED; | |
4dd63d48 | 1965 | else if (event == PTRACE_EVENT_CLONE) |
3d799a95 | 1966 | { |
78768c4a JK |
1967 | struct lwp_info *new_lp; |
1968 | ||
3d799a95 | 1969 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
78768c4a | 1970 | |
9327494e SM |
1971 | linux_nat_debug_printf |
1972 | ("Got clone event from LWP %d, new child is LWP %ld", pid, new_pid); | |
3c4d7e12 | 1973 | |
e99b03dc | 1974 | new_lp = add_lwp (ptid_t (lp->ptid.pid (), new_pid, 0)); |
4c28f408 | 1975 | new_lp->stopped = 1; |
4dd63d48 | 1976 | new_lp->resumed = 1; |
d6b0e80f | 1977 | |
2db9a427 PA |
1978 | /* If the thread_db layer is active, let it record the user |
1979 | level thread id and status, and add the thread to GDB's | |
1980 | list. */ | |
1981 | if (!thread_db_notice_clone (lp->ptid, new_lp->ptid)) | |
3d799a95 | 1982 | { |
2db9a427 PA |
1983 | /* The process is not using thread_db. Add the LWP to |
1984 | GDB's list. */ | |
e38504b3 | 1985 | target_post_attach (new_lp->ptid.lwp ()); |
5b6d1e4f | 1986 | add_thread (linux_target, new_lp->ptid); |
2db9a427 | 1987 | } |
4c28f408 | 1988 | |
2ee52aa4 | 1989 | /* Even if we're stopping the thread for some reason |
4dd63d48 PA |
1990 | internal to this module, from the perspective of infrun |
1991 | and the user/frontend, this new thread is running until | |
1992 | it next reports a stop. */ | |
719546c4 SM |
1993 | set_running (linux_target, new_lp->ptid, true); |
1994 | set_executing (linux_target, new_lp->ptid, true); | |
4c28f408 | 1995 | |
4dd63d48 | 1996 | if (WSTOPSIG (status) != SIGSTOP) |
79395f92 | 1997 | { |
4dd63d48 PA |
1998 | /* This can happen if someone starts sending signals to |
1999 | the new thread before it gets a chance to run, which | |
2000 | have a lower number than SIGSTOP (e.g. SIGUSR1). | |
2001 | This is an unlikely case, and harder to handle for | |
2002 | fork / vfork than for clone, so we do not try - but | |
2003 | we handle it for clone events here. */ | |
2004 | ||
2005 | new_lp->signalled = 1; | |
2006 | ||
79395f92 PA |
2007 | /* We created NEW_LP so it cannot yet contain STATUS. */ |
2008 | gdb_assert (new_lp->status == 0); | |
2009 | ||
2010 | /* Save the wait status to report later. */ | |
9327494e SM |
2011 | linux_nat_debug_printf |
2012 | ("waitpid of new LWP %ld, saving status %s", | |
8d06918f | 2013 | (long) new_lp->ptid.lwp (), status_to_str (status).c_str ()); |
79395f92 PA |
2014 | new_lp->status = status; |
2015 | } | |
aa01bd36 PA |
2016 | else if (report_thread_events) |
2017 | { | |
2018 | new_lp->waitstatus.kind = TARGET_WAITKIND_THREAD_CREATED; | |
2019 | new_lp->status = status; | |
2020 | } | |
79395f92 | 2021 | |
3d799a95 DJ |
2022 | return 1; |
2023 | } | |
2024 | ||
2025 | return 0; | |
d6b0e80f AC |
2026 | } |
2027 | ||
3d799a95 DJ |
2028 | if (event == PTRACE_EVENT_EXEC) |
2029 | { | |
9327494e | 2030 | linux_nat_debug_printf ("Got exec event from LWP %ld", lp->ptid.lwp ()); |
a75724bc | 2031 | |
05c06f31 PA |
2032 | /* Close the /proc/<pid>/mem file if it was open for this |
2033 | inferior. */ | |
2034 | maybe_close_proc_mem_file (lp->ptid.pid ()); | |
2035 | ||
3d799a95 DJ |
2036 | ourstatus->kind = TARGET_WAITKIND_EXECD; |
2037 | ourstatus->value.execd_pathname | |
f6ac5f3d | 2038 | = xstrdup (linux_proc_pid_to_exec_file (pid)); |
3d799a95 | 2039 | |
8af756ef PA |
2040 | /* The thread that execed must have been resumed, but, when a |
2041 | thread execs, it changes its tid to the tgid, and the old | |
2042 | tgid thread might have not been resumed. */ | |
2043 | lp->resumed = 1; | |
6c95b8df PA |
2044 | return 0; |
2045 | } | |
2046 | ||
2047 | if (event == PTRACE_EVENT_VFORK_DONE) | |
2048 | { | |
2049 | if (current_inferior ()->waiting_for_vfork_done) | |
3d799a95 | 2050 | { |
9327494e SM |
2051 | linux_nat_debug_printf |
2052 | ("Got expected PTRACE_EVENT_VFORK_DONE from LWP %ld: stopping", | |
2053 | lp->ptid.lwp ()); | |
3d799a95 | 2054 | |
6c95b8df PA |
2055 | ourstatus->kind = TARGET_WAITKIND_VFORK_DONE; |
2056 | return 0; | |
3d799a95 DJ |
2057 | } |
2058 | ||
9327494e SM |
2059 | linux_nat_debug_printf |
2060 | ("Got PTRACE_EVENT_VFORK_DONE from LWP %ld: ignoring", lp->ptid.lwp ()); | |
2061 | ||
6c95b8df | 2062 | return 1; |
3d799a95 DJ |
2063 | } |
2064 | ||
2065 | internal_error (__FILE__, __LINE__, | |
2066 | _("unknown ptrace event %d"), event); | |
d6b0e80f AC |
2067 | } |
2068 | ||
9c3a5d93 PA |
2069 | /* Suspend waiting for a signal. We're mostly interested in |
2070 | SIGCHLD/SIGINT. */ | |
2071 | ||
2072 | static void | |
2073 | wait_for_signal () | |
2074 | { | |
9327494e | 2075 | linux_nat_debug_printf ("about to sigsuspend"); |
9c3a5d93 PA |
2076 | sigsuspend (&suspend_mask); |
2077 | ||
2078 | /* If the quit flag is set, it means that the user pressed Ctrl-C | |
2079 | and we're debugging a process that is running on a separate | |
2080 | terminal, so we must forward the Ctrl-C to the inferior. (If the | |
2081 | inferior is sharing GDB's terminal, then the Ctrl-C reaches the | |
2082 | inferior directly.) We must do this here because functions that | |
2083 | need to block waiting for a signal loop forever until there's an | |
2084 | event to report before returning back to the event loop. */ | |
2085 | if (!target_terminal::is_ours ()) | |
2086 | { | |
2087 | if (check_quit_flag ()) | |
2088 | target_pass_ctrlc (); | |
2089 | } | |
2090 | } | |
2091 | ||
d6b0e80f AC |
2092 | /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has |
2093 | exited. */ | |
2094 | ||
2095 | static int | |
2096 | wait_lwp (struct lwp_info *lp) | |
2097 | { | |
2098 | pid_t pid; | |
432b4d03 | 2099 | int status = 0; |
d6b0e80f | 2100 | int thread_dead = 0; |
432b4d03 | 2101 | sigset_t prev_mask; |
d6b0e80f AC |
2102 | |
2103 | gdb_assert (!lp->stopped); | |
2104 | gdb_assert (lp->status == 0); | |
2105 | ||
432b4d03 JK |
2106 | /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
2107 | block_child_signals (&prev_mask); | |
2108 | ||
2109 | for (;;) | |
d6b0e80f | 2110 | { |
e38504b3 | 2111 | pid = my_waitpid (lp->ptid.lwp (), &status, __WALL | WNOHANG); |
a9f4bb21 PA |
2112 | if (pid == -1 && errno == ECHILD) |
2113 | { | |
2114 | /* The thread has previously exited. We need to delete it | |
4a6ed09b PA |
2115 | now because if this was a non-leader thread execing, we |
2116 | won't get an exit event. See comments on exec events at | |
2117 | the top of the file. */ | |
a9f4bb21 | 2118 | thread_dead = 1; |
9327494e SM |
2119 | linux_nat_debug_printf ("%s vanished.", |
2120 | target_pid_to_str (lp->ptid).c_str ()); | |
a9f4bb21 | 2121 | } |
432b4d03 JK |
2122 | if (pid != 0) |
2123 | break; | |
2124 | ||
2125 | /* Bugs 10970, 12702. | |
2126 | Thread group leader may have exited in which case we'll lock up in | |
2127 | waitpid if there are other threads, even if they are all zombies too. | |
2128 | Basically, we're not supposed to use waitpid this way. | |
4a6ed09b PA |
2129 | tkill(pid,0) cannot be used here as it gets ESRCH for both |
2130 | for zombie and running processes. | |
432b4d03 JK |
2131 | |
2132 | As a workaround, check if we're waiting for the thread group leader and | |
2133 | if it's a zombie, and avoid calling waitpid if it is. | |
2134 | ||
2135 | This is racy, what if the tgl becomes a zombie right after we check? | |
2136 | Therefore always use WNOHANG with sigsuspend - it is equivalent to | |
5f572dec | 2137 | waiting waitpid but linux_proc_pid_is_zombie is safe this way. */ |
432b4d03 | 2138 | |
e38504b3 TT |
2139 | if (lp->ptid.pid () == lp->ptid.lwp () |
2140 | && linux_proc_pid_is_zombie (lp->ptid.lwp ())) | |
d6b0e80f | 2141 | { |
d6b0e80f | 2142 | thread_dead = 1; |
9327494e SM |
2143 | linux_nat_debug_printf ("Thread group leader %s vanished.", |
2144 | target_pid_to_str (lp->ptid).c_str ()); | |
432b4d03 | 2145 | break; |
d6b0e80f | 2146 | } |
432b4d03 JK |
2147 | |
2148 | /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers | |
2149 | get invoked despite our caller had them intentionally blocked by | |
2150 | block_child_signals. This is sensitive only to the loop of | |
2151 | linux_nat_wait_1 and there if we get called my_waitpid gets called | |
2152 | again before it gets to sigsuspend so we can safely let the handlers | |
2153 | get executed here. */ | |
9c3a5d93 | 2154 | wait_for_signal (); |
432b4d03 JK |
2155 | } |
2156 | ||
2157 | restore_child_signals_mask (&prev_mask); | |
2158 | ||
d6b0e80f AC |
2159 | if (!thread_dead) |
2160 | { | |
e38504b3 | 2161 | gdb_assert (pid == lp->ptid.lwp ()); |
d6b0e80f | 2162 | |
9327494e | 2163 | linux_nat_debug_printf ("waitpid %s received %s", |
a068643d | 2164 | target_pid_to_str (lp->ptid).c_str (), |
8d06918f | 2165 | status_to_str (status).c_str ()); |
d6b0e80f | 2166 | |
a9f4bb21 PA |
2167 | /* Check if the thread has exited. */ |
2168 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
2169 | { | |
aa01bd36 | 2170 | if (report_thread_events |
e38504b3 | 2171 | || lp->ptid.pid () == lp->ptid.lwp ()) |
69dde7dc | 2172 | { |
9327494e | 2173 | linux_nat_debug_printf ("LWP %d exited.", lp->ptid.pid ()); |
69dde7dc | 2174 | |
aa01bd36 | 2175 | /* If this is the leader exiting, it means the whole |
69dde7dc PA |
2176 | process is gone. Store the status to report to the |
2177 | core. Store it in lp->waitstatus, because lp->status | |
2178 | would be ambiguous (W_EXITCODE(0,0) == 0). */ | |
2179 | store_waitstatus (&lp->waitstatus, status); | |
2180 | return 0; | |
2181 | } | |
2182 | ||
a9f4bb21 | 2183 | thread_dead = 1; |
9327494e SM |
2184 | linux_nat_debug_printf ("%s exited.", |
2185 | target_pid_to_str (lp->ptid).c_str ()); | |
a9f4bb21 | 2186 | } |
d6b0e80f AC |
2187 | } |
2188 | ||
2189 | if (thread_dead) | |
2190 | { | |
e26af52f | 2191 | exit_lwp (lp); |
d6b0e80f AC |
2192 | return 0; |
2193 | } | |
2194 | ||
2195 | gdb_assert (WIFSTOPPED (status)); | |
8817a6f2 | 2196 | lp->stopped = 1; |
d6b0e80f | 2197 | |
8784d563 PA |
2198 | if (lp->must_set_ptrace_flags) |
2199 | { | |
5b6d1e4f | 2200 | inferior *inf = find_inferior_pid (linux_target, lp->ptid.pid ()); |
de0d863e | 2201 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 2202 | |
e38504b3 | 2203 | linux_enable_event_reporting (lp->ptid.lwp (), options); |
8784d563 PA |
2204 | lp->must_set_ptrace_flags = 0; |
2205 | } | |
2206 | ||
ca2163eb PA |
2207 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2208 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2209 | { | |
2210 | /* No longer need the sysgood bit. The ptrace event ends up | |
2211 | recorded in lp->waitstatus if we care for it. We can carry | |
2212 | on handling the event like a regular SIGTRAP from here | |
2213 | on. */ | |
2214 | status = W_STOPCODE (SIGTRAP); | |
2215 | if (linux_handle_syscall_trap (lp, 1)) | |
2216 | return wait_lwp (lp); | |
2217 | } | |
bfd09d20 JS |
2218 | else |
2219 | { | |
2220 | /* Almost all other ptrace-stops are known to be outside of system | |
2221 | calls, with further exceptions in linux_handle_extended_wait. */ | |
2222 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2223 | } | |
ca2163eb | 2224 | |
d6b0e80f | 2225 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2226 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2227 | && linux_is_extended_waitstatus (status)) | |
d6b0e80f | 2228 | { |
9327494e | 2229 | linux_nat_debug_printf ("Handling extended status 0x%06x", status); |
4dd63d48 | 2230 | linux_handle_extended_wait (lp, status); |
20ba1ce6 | 2231 | return 0; |
d6b0e80f AC |
2232 | } |
2233 | ||
2234 | return status; | |
2235 | } | |
2236 | ||
2237 | /* Send a SIGSTOP to LP. */ | |
2238 | ||
2239 | static int | |
d3a70e03 | 2240 | stop_callback (struct lwp_info *lp) |
d6b0e80f AC |
2241 | { |
2242 | if (!lp->stopped && !lp->signalled) | |
2243 | { | |
2244 | int ret; | |
2245 | ||
9327494e | 2246 | linux_nat_debug_printf ("kill %s **<SIGSTOP>**", |
a068643d | 2247 | target_pid_to_str (lp->ptid).c_str ()); |
9327494e | 2248 | |
d6b0e80f | 2249 | errno = 0; |
e38504b3 | 2250 | ret = kill_lwp (lp->ptid.lwp (), SIGSTOP); |
9327494e | 2251 | linux_nat_debug_printf ("lwp kill %d %s", ret, |
d6b0e80f | 2252 | errno ? safe_strerror (errno) : "ERRNO-OK"); |
d6b0e80f AC |
2253 | |
2254 | lp->signalled = 1; | |
2255 | gdb_assert (lp->status == 0); | |
2256 | } | |
2257 | ||
2258 | return 0; | |
2259 | } | |
2260 | ||
7b50312a PA |
2261 | /* Request a stop on LWP. */ |
2262 | ||
2263 | void | |
2264 | linux_stop_lwp (struct lwp_info *lwp) | |
2265 | { | |
d3a70e03 | 2266 | stop_callback (lwp); |
7b50312a PA |
2267 | } |
2268 | ||
2db9a427 PA |
2269 | /* See linux-nat.h */ |
2270 | ||
2271 | void | |
2272 | linux_stop_and_wait_all_lwps (void) | |
2273 | { | |
2274 | /* Stop all LWP's ... */ | |
d3a70e03 | 2275 | iterate_over_lwps (minus_one_ptid, stop_callback); |
2db9a427 PA |
2276 | |
2277 | /* ... and wait until all of them have reported back that | |
2278 | they're no longer running. */ | |
d3a70e03 | 2279 | iterate_over_lwps (minus_one_ptid, stop_wait_callback); |
2db9a427 PA |
2280 | } |
2281 | ||
2282 | /* See linux-nat.h */ | |
2283 | ||
2284 | void | |
2285 | linux_unstop_all_lwps (void) | |
2286 | { | |
2287 | iterate_over_lwps (minus_one_ptid, | |
d3a70e03 TT |
2288 | [] (struct lwp_info *info) |
2289 | { | |
2290 | return resume_stopped_resumed_lwps (info, minus_one_ptid); | |
2291 | }); | |
2db9a427 PA |
2292 | } |
2293 | ||
57380f4e | 2294 | /* Return non-zero if LWP PID has a pending SIGINT. */ |
d6b0e80f AC |
2295 | |
2296 | static int | |
57380f4e DJ |
2297 | linux_nat_has_pending_sigint (int pid) |
2298 | { | |
2299 | sigset_t pending, blocked, ignored; | |
57380f4e DJ |
2300 | |
2301 | linux_proc_pending_signals (pid, &pending, &blocked, &ignored); | |
2302 | ||
2303 | if (sigismember (&pending, SIGINT) | |
2304 | && !sigismember (&ignored, SIGINT)) | |
2305 | return 1; | |
2306 | ||
2307 | return 0; | |
2308 | } | |
2309 | ||
2310 | /* Set a flag in LP indicating that we should ignore its next SIGINT. */ | |
2311 | ||
2312 | static int | |
d3a70e03 | 2313 | set_ignore_sigint (struct lwp_info *lp) |
d6b0e80f | 2314 | { |
57380f4e DJ |
2315 | /* If a thread has a pending SIGINT, consume it; otherwise, set a |
2316 | flag to consume the next one. */ | |
2317 | if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) | |
2318 | && WSTOPSIG (lp->status) == SIGINT) | |
2319 | lp->status = 0; | |
2320 | else | |
2321 | lp->ignore_sigint = 1; | |
2322 | ||
2323 | return 0; | |
2324 | } | |
2325 | ||
2326 | /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. | |
2327 | This function is called after we know the LWP has stopped; if the LWP | |
2328 | stopped before the expected SIGINT was delivered, then it will never have | |
2329 | arrived. Also, if the signal was delivered to a shared queue and consumed | |
2330 | by a different thread, it will never be delivered to this LWP. */ | |
d6b0e80f | 2331 | |
57380f4e DJ |
2332 | static void |
2333 | maybe_clear_ignore_sigint (struct lwp_info *lp) | |
2334 | { | |
2335 | if (!lp->ignore_sigint) | |
2336 | return; | |
2337 | ||
e38504b3 | 2338 | if (!linux_nat_has_pending_sigint (lp->ptid.lwp ())) |
57380f4e | 2339 | { |
9327494e SM |
2340 | linux_nat_debug_printf ("Clearing bogus flag for %s", |
2341 | target_pid_to_str (lp->ptid).c_str ()); | |
57380f4e DJ |
2342 | lp->ignore_sigint = 0; |
2343 | } | |
2344 | } | |
2345 | ||
ebec9a0f PA |
2346 | /* Fetch the possible triggered data watchpoint info and store it in |
2347 | LP. | |
2348 | ||
2349 | On some archs, like x86, that use debug registers to set | |
2350 | watchpoints, it's possible that the way to know which watched | |
2351 | address trapped, is to check the register that is used to select | |
2352 | which address to watch. Problem is, between setting the watchpoint | |
2353 | and reading back which data address trapped, the user may change | |
2354 | the set of watchpoints, and, as a consequence, GDB changes the | |
2355 | debug registers in the inferior. To avoid reading back a stale | |
2356 | stopped-data-address when that happens, we cache in LP the fact | |
2357 | that a watchpoint trapped, and the corresponding data address, as | |
2358 | soon as we see LP stop with a SIGTRAP. If GDB changes the debug | |
2359 | registers meanwhile, we have the cached data we can rely on. */ | |
2360 | ||
9c02b525 PA |
2361 | static int |
2362 | check_stopped_by_watchpoint (struct lwp_info *lp) | |
ebec9a0f | 2363 | { |
2989a365 | 2364 | scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); |
ebec9a0f PA |
2365 | inferior_ptid = lp->ptid; |
2366 | ||
f6ac5f3d | 2367 | if (linux_target->low_stopped_by_watchpoint ()) |
ebec9a0f | 2368 | { |
15c66dd6 | 2369 | lp->stop_reason = TARGET_STOPPED_BY_WATCHPOINT; |
f6ac5f3d PA |
2370 | lp->stopped_data_address_p |
2371 | = linux_target->low_stopped_data_address (&lp->stopped_data_address); | |
ebec9a0f PA |
2372 | } |
2373 | ||
15c66dd6 | 2374 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
9c02b525 PA |
2375 | } |
2376 | ||
9c02b525 | 2377 | /* Returns true if the LWP had stopped for a watchpoint. */ |
ebec9a0f | 2378 | |
57810aa7 | 2379 | bool |
f6ac5f3d | 2380 | linux_nat_target::stopped_by_watchpoint () |
ebec9a0f PA |
2381 | { |
2382 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2383 | ||
2384 | gdb_assert (lp != NULL); | |
2385 | ||
15c66dd6 | 2386 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
ebec9a0f PA |
2387 | } |
2388 | ||
57810aa7 | 2389 | bool |
f6ac5f3d | 2390 | linux_nat_target::stopped_data_address (CORE_ADDR *addr_p) |
ebec9a0f PA |
2391 | { |
2392 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2393 | ||
2394 | gdb_assert (lp != NULL); | |
2395 | ||
2396 | *addr_p = lp->stopped_data_address; | |
2397 | ||
2398 | return lp->stopped_data_address_p; | |
2399 | } | |
2400 | ||
26ab7092 JK |
2401 | /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
2402 | ||
135340af PA |
2403 | bool |
2404 | linux_nat_target::low_status_is_event (int status) | |
26ab7092 JK |
2405 | { |
2406 | return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; | |
2407 | } | |
2408 | ||
57380f4e DJ |
2409 | /* Wait until LP is stopped. */ |
2410 | ||
2411 | static int | |
d3a70e03 | 2412 | stop_wait_callback (struct lwp_info *lp) |
57380f4e | 2413 | { |
5b6d1e4f | 2414 | inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
6c95b8df PA |
2415 | |
2416 | /* If this is a vfork parent, bail out, it is not going to report | |
2417 | any SIGSTOP until the vfork is done with. */ | |
2418 | if (inf->vfork_child != NULL) | |
2419 | return 0; | |
2420 | ||
d6b0e80f AC |
2421 | if (!lp->stopped) |
2422 | { | |
2423 | int status; | |
2424 | ||
2425 | status = wait_lwp (lp); | |
2426 | if (status == 0) | |
2427 | return 0; | |
2428 | ||
57380f4e DJ |
2429 | if (lp->ignore_sigint && WIFSTOPPED (status) |
2430 | && WSTOPSIG (status) == SIGINT) | |
d6b0e80f | 2431 | { |
57380f4e | 2432 | lp->ignore_sigint = 0; |
d6b0e80f AC |
2433 | |
2434 | errno = 0; | |
e38504b3 | 2435 | ptrace (PTRACE_CONT, lp->ptid.lwp (), 0, 0); |
8817a6f2 | 2436 | lp->stopped = 0; |
9327494e SM |
2437 | linux_nat_debug_printf |
2438 | ("PTRACE_CONT %s, 0, 0 (%s) (discarding SIGINT)", | |
2439 | target_pid_to_str (lp->ptid).c_str (), | |
2440 | errno ? safe_strerror (errno) : "OK"); | |
d6b0e80f | 2441 | |
d3a70e03 | 2442 | return stop_wait_callback (lp); |
d6b0e80f AC |
2443 | } |
2444 | ||
57380f4e DJ |
2445 | maybe_clear_ignore_sigint (lp); |
2446 | ||
d6b0e80f AC |
2447 | if (WSTOPSIG (status) != SIGSTOP) |
2448 | { | |
e5ef252a | 2449 | /* The thread was stopped with a signal other than SIGSTOP. */ |
7feb7d06 | 2450 | |
9327494e | 2451 | linux_nat_debug_printf ("Pending event %s in %s", |
8d06918f | 2452 | status_to_str ((int) status).c_str (), |
9327494e | 2453 | target_pid_to_str (lp->ptid).c_str ()); |
e5ef252a PA |
2454 | |
2455 | /* Save the sigtrap event. */ | |
2456 | lp->status = status; | |
e5ef252a | 2457 | gdb_assert (lp->signalled); |
e7ad2f14 | 2458 | save_stop_reason (lp); |
d6b0e80f AC |
2459 | } |
2460 | else | |
2461 | { | |
7010835a | 2462 | /* We caught the SIGSTOP that we intended to catch. */ |
e5ef252a | 2463 | |
9327494e SM |
2464 | linux_nat_debug_printf ("Expected SIGSTOP caught for %s.", |
2465 | target_pid_to_str (lp->ptid).c_str ()); | |
e5ef252a | 2466 | |
d6b0e80f | 2467 | lp->signalled = 0; |
7010835a AB |
2468 | |
2469 | /* If we are waiting for this stop so we can report the thread | |
2470 | stopped then we need to record this status. Otherwise, we can | |
2471 | now discard this stop event. */ | |
2472 | if (lp->last_resume_kind == resume_stop) | |
2473 | { | |
2474 | lp->status = status; | |
2475 | save_stop_reason (lp); | |
2476 | } | |
d6b0e80f AC |
2477 | } |
2478 | } | |
2479 | ||
2480 | return 0; | |
2481 | } | |
2482 | ||
9c02b525 PA |
2483 | /* Return non-zero if LP has a wait status pending. Discard the |
2484 | pending event and resume the LWP if the event that originally | |
2485 | caused the stop became uninteresting. */ | |
d6b0e80f AC |
2486 | |
2487 | static int | |
d3a70e03 | 2488 | status_callback (struct lwp_info *lp) |
d6b0e80f AC |
2489 | { |
2490 | /* Only report a pending wait status if we pretend that this has | |
2491 | indeed been resumed. */ | |
ca2163eb PA |
2492 | if (!lp->resumed) |
2493 | return 0; | |
2494 | ||
eb54c8bf PA |
2495 | if (!lwp_status_pending_p (lp)) |
2496 | return 0; | |
2497 | ||
15c66dd6 PA |
2498 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
2499 | || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) | |
9c02b525 | 2500 | { |
5b6d1e4f | 2501 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
9c02b525 PA |
2502 | CORE_ADDR pc; |
2503 | int discard = 0; | |
2504 | ||
9c02b525 PA |
2505 | pc = regcache_read_pc (regcache); |
2506 | ||
2507 | if (pc != lp->stop_pc) | |
2508 | { | |
9327494e SM |
2509 | linux_nat_debug_printf ("PC of %s changed. was=%s, now=%s", |
2510 | target_pid_to_str (lp->ptid).c_str (), | |
2511 | paddress (target_gdbarch (), lp->stop_pc), | |
2512 | paddress (target_gdbarch (), pc)); | |
9c02b525 PA |
2513 | discard = 1; |
2514 | } | |
faf09f01 PA |
2515 | |
2516 | #if !USE_SIGTRAP_SIGINFO | |
a01bda52 | 2517 | else if (!breakpoint_inserted_here_p (regcache->aspace (), pc)) |
9c02b525 | 2518 | { |
9327494e SM |
2519 | linux_nat_debug_printf ("previous breakpoint of %s, at %s gone", |
2520 | target_pid_to_str (lp->ptid).c_str (), | |
2521 | paddress (target_gdbarch (), lp->stop_pc)); | |
9c02b525 PA |
2522 | |
2523 | discard = 1; | |
2524 | } | |
faf09f01 | 2525 | #endif |
9c02b525 PA |
2526 | |
2527 | if (discard) | |
2528 | { | |
9327494e SM |
2529 | linux_nat_debug_printf ("pending event of %s cancelled.", |
2530 | target_pid_to_str (lp->ptid).c_str ()); | |
9c02b525 PA |
2531 | |
2532 | lp->status = 0; | |
2533 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); | |
2534 | return 0; | |
2535 | } | |
9c02b525 PA |
2536 | } |
2537 | ||
eb54c8bf | 2538 | return 1; |
d6b0e80f AC |
2539 | } |
2540 | ||
d6b0e80f AC |
2541 | /* Count the LWP's that have had events. */ |
2542 | ||
2543 | static int | |
d3a70e03 | 2544 | count_events_callback (struct lwp_info *lp, int *count) |
d6b0e80f | 2545 | { |
d6b0e80f AC |
2546 | gdb_assert (count != NULL); |
2547 | ||
9c02b525 PA |
2548 | /* Select only resumed LWPs that have an event pending. */ |
2549 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2550 | (*count)++; |
2551 | ||
2552 | return 0; | |
2553 | } | |
2554 | ||
2555 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
2556 | ||
2557 | static int | |
d3a70e03 | 2558 | select_singlestep_lwp_callback (struct lwp_info *lp) |
d6b0e80f | 2559 | { |
25289eb2 PA |
2560 | if (lp->last_resume_kind == resume_step |
2561 | && lp->status != 0) | |
d6b0e80f AC |
2562 | return 1; |
2563 | else | |
2564 | return 0; | |
2565 | } | |
2566 | ||
8a99810d PA |
2567 | /* Returns true if LP has a status pending. */ |
2568 | ||
2569 | static int | |
2570 | lwp_status_pending_p (struct lwp_info *lp) | |
2571 | { | |
2572 | /* We check for lp->waitstatus in addition to lp->status, because we | |
2573 | can have pending process exits recorded in lp->status and | |
2574 | W_EXITCODE(0,0) happens to be 0. */ | |
2575 | return lp->status != 0 || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE; | |
2576 | } | |
2577 | ||
b90fc188 | 2578 | /* Select the Nth LWP that has had an event. */ |
d6b0e80f AC |
2579 | |
2580 | static int | |
d3a70e03 | 2581 | select_event_lwp_callback (struct lwp_info *lp, int *selector) |
d6b0e80f | 2582 | { |
d6b0e80f AC |
2583 | gdb_assert (selector != NULL); |
2584 | ||
9c02b525 PA |
2585 | /* Select only resumed LWPs that have an event pending. */ |
2586 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2587 | if ((*selector)-- == 0) |
2588 | return 1; | |
2589 | ||
2590 | return 0; | |
2591 | } | |
2592 | ||
e7ad2f14 PA |
2593 | /* Called when the LWP stopped for a signal/trap. If it stopped for a |
2594 | trap check what caused it (breakpoint, watchpoint, trace, etc.), | |
2595 | and save the result in the LWP's stop_reason field. If it stopped | |
2596 | for a breakpoint, decrement the PC if necessary on the lwp's | |
2597 | architecture. */ | |
9c02b525 | 2598 | |
e7ad2f14 PA |
2599 | static void |
2600 | save_stop_reason (struct lwp_info *lp) | |
710151dd | 2601 | { |
e7ad2f14 PA |
2602 | struct regcache *regcache; |
2603 | struct gdbarch *gdbarch; | |
515630c5 | 2604 | CORE_ADDR pc; |
9c02b525 | 2605 | CORE_ADDR sw_bp_pc; |
faf09f01 PA |
2606 | #if USE_SIGTRAP_SIGINFO |
2607 | siginfo_t siginfo; | |
2608 | #endif | |
9c02b525 | 2609 | |
e7ad2f14 PA |
2610 | gdb_assert (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON); |
2611 | gdb_assert (lp->status != 0); | |
2612 | ||
135340af | 2613 | if (!linux_target->low_status_is_event (lp->status)) |
e7ad2f14 PA |
2614 | return; |
2615 | ||
5b6d1e4f | 2616 | regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 2617 | gdbarch = regcache->arch (); |
e7ad2f14 | 2618 | |
9c02b525 | 2619 | pc = regcache_read_pc (regcache); |
527a273a | 2620 | sw_bp_pc = pc - gdbarch_decr_pc_after_break (gdbarch); |
515630c5 | 2621 | |
faf09f01 PA |
2622 | #if USE_SIGTRAP_SIGINFO |
2623 | if (linux_nat_get_siginfo (lp->ptid, &siginfo)) | |
2624 | { | |
2625 | if (siginfo.si_signo == SIGTRAP) | |
2626 | { | |
e7ad2f14 PA |
2627 | if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code) |
2628 | && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) | |
faf09f01 | 2629 | { |
e7ad2f14 PA |
2630 | /* The si_code is ambiguous on this arch -- check debug |
2631 | registers. */ | |
2632 | if (!check_stopped_by_watchpoint (lp)) | |
2633 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2634 | } | |
2635 | else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)) | |
2636 | { | |
2637 | /* If we determine the LWP stopped for a SW breakpoint, | |
2638 | trust it. Particularly don't check watchpoint | |
7da6a5b9 | 2639 | registers, because, at least on s390, we'd find |
e7ad2f14 PA |
2640 | stopped-by-watchpoint as long as there's a watchpoint |
2641 | set. */ | |
faf09f01 | 2642 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
faf09f01 | 2643 | } |
e7ad2f14 | 2644 | else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) |
faf09f01 | 2645 | { |
e7ad2f14 PA |
2646 | /* This can indicate either a hardware breakpoint or |
2647 | hardware watchpoint. Check debug registers. */ | |
2648 | if (!check_stopped_by_watchpoint (lp)) | |
2649 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; | |
faf09f01 | 2650 | } |
2bf6fb9d PA |
2651 | else if (siginfo.si_code == TRAP_TRACE) |
2652 | { | |
9327494e SM |
2653 | linux_nat_debug_printf ("%s stopped by trace", |
2654 | target_pid_to_str (lp->ptid).c_str ()); | |
e7ad2f14 PA |
2655 | |
2656 | /* We may have single stepped an instruction that | |
2657 | triggered a watchpoint. In that case, on some | |
2658 | architectures (such as x86), instead of TRAP_HWBKPT, | |
2659 | si_code indicates TRAP_TRACE, and we need to check | |
2660 | the debug registers separately. */ | |
2661 | check_stopped_by_watchpoint (lp); | |
2bf6fb9d | 2662 | } |
faf09f01 PA |
2663 | } |
2664 | } | |
2665 | #else | |
9c02b525 | 2666 | if ((!lp->step || lp->stop_pc == sw_bp_pc) |
a01bda52 | 2667 | && software_breakpoint_inserted_here_p (regcache->aspace (), |
9c02b525 | 2668 | sw_bp_pc)) |
710151dd | 2669 | { |
9c02b525 PA |
2670 | /* The LWP was either continued, or stepped a software |
2671 | breakpoint instruction. */ | |
e7ad2f14 PA |
2672 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
2673 | } | |
2674 | ||
a01bda52 | 2675 | if (hardware_breakpoint_inserted_here_p (regcache->aspace (), pc)) |
e7ad2f14 PA |
2676 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; |
2677 | ||
2678 | if (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON) | |
2679 | check_stopped_by_watchpoint (lp); | |
2680 | #endif | |
2681 | ||
2682 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT) | |
2683 | { | |
9327494e SM |
2684 | linux_nat_debug_printf ("%s stopped by software breakpoint", |
2685 | target_pid_to_str (lp->ptid).c_str ()); | |
710151dd PA |
2686 | |
2687 | /* Back up the PC if necessary. */ | |
9c02b525 PA |
2688 | if (pc != sw_bp_pc) |
2689 | regcache_write_pc (regcache, sw_bp_pc); | |
515630c5 | 2690 | |
e7ad2f14 PA |
2691 | /* Update this so we record the correct stop PC below. */ |
2692 | pc = sw_bp_pc; | |
710151dd | 2693 | } |
e7ad2f14 | 2694 | else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) |
9c02b525 | 2695 | { |
9327494e SM |
2696 | linux_nat_debug_printf ("%s stopped by hardware breakpoint", |
2697 | target_pid_to_str (lp->ptid).c_str ()); | |
e7ad2f14 PA |
2698 | } |
2699 | else if (lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT) | |
2700 | { | |
9327494e SM |
2701 | linux_nat_debug_printf ("%s stopped by hardware watchpoint", |
2702 | target_pid_to_str (lp->ptid).c_str ()); | |
9c02b525 | 2703 | } |
d6b0e80f | 2704 | |
e7ad2f14 | 2705 | lp->stop_pc = pc; |
d6b0e80f AC |
2706 | } |
2707 | ||
faf09f01 PA |
2708 | |
2709 | /* Returns true if the LWP had stopped for a software breakpoint. */ | |
2710 | ||
57810aa7 | 2711 | bool |
f6ac5f3d | 2712 | linux_nat_target::stopped_by_sw_breakpoint () |
faf09f01 PA |
2713 | { |
2714 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2715 | ||
2716 | gdb_assert (lp != NULL); | |
2717 | ||
2718 | return lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2719 | } | |
2720 | ||
2721 | /* Implement the supports_stopped_by_sw_breakpoint method. */ | |
2722 | ||
57810aa7 | 2723 | bool |
f6ac5f3d | 2724 | linux_nat_target::supports_stopped_by_sw_breakpoint () |
faf09f01 PA |
2725 | { |
2726 | return USE_SIGTRAP_SIGINFO; | |
2727 | } | |
2728 | ||
2729 | /* Returns true if the LWP had stopped for a hardware | |
2730 | breakpoint/watchpoint. */ | |
2731 | ||
57810aa7 | 2732 | bool |
f6ac5f3d | 2733 | linux_nat_target::stopped_by_hw_breakpoint () |
faf09f01 PA |
2734 | { |
2735 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2736 | ||
2737 | gdb_assert (lp != NULL); | |
2738 | ||
2739 | return lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT; | |
2740 | } | |
2741 | ||
2742 | /* Implement the supports_stopped_by_hw_breakpoint method. */ | |
2743 | ||
57810aa7 | 2744 | bool |
f6ac5f3d | 2745 | linux_nat_target::supports_stopped_by_hw_breakpoint () |
faf09f01 PA |
2746 | { |
2747 | return USE_SIGTRAP_SIGINFO; | |
2748 | } | |
2749 | ||
d6b0e80f AC |
2750 | /* Select one LWP out of those that have events pending. */ |
2751 | ||
2752 | static void | |
d90e17a7 | 2753 | select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
d6b0e80f AC |
2754 | { |
2755 | int num_events = 0; | |
2756 | int random_selector; | |
9c02b525 | 2757 | struct lwp_info *event_lp = NULL; |
d6b0e80f | 2758 | |
ac264b3b | 2759 | /* Record the wait status for the original LWP. */ |
d6b0e80f AC |
2760 | (*orig_lp)->status = *status; |
2761 | ||
9c02b525 PA |
2762 | /* In all-stop, give preference to the LWP that is being |
2763 | single-stepped. There will be at most one, and it will be the | |
2764 | LWP that the core is most interested in. If we didn't do this, | |
2765 | then we'd have to handle pending step SIGTRAPs somehow in case | |
2766 | the core later continues the previously-stepped thread, as | |
2767 | otherwise we'd report the pending SIGTRAP then, and the core, not | |
2768 | having stepped the thread, wouldn't understand what the trap was | |
2769 | for, and therefore would report it to the user as a random | |
2770 | signal. */ | |
fbea99ea | 2771 | if (!target_is_non_stop_p ()) |
d6b0e80f | 2772 | { |
d3a70e03 | 2773 | event_lp = iterate_over_lwps (filter, select_singlestep_lwp_callback); |
9c02b525 PA |
2774 | if (event_lp != NULL) |
2775 | { | |
9327494e SM |
2776 | linux_nat_debug_printf ("Select single-step %s", |
2777 | target_pid_to_str (event_lp->ptid).c_str ()); | |
9c02b525 | 2778 | } |
d6b0e80f | 2779 | } |
9c02b525 PA |
2780 | |
2781 | if (event_lp == NULL) | |
d6b0e80f | 2782 | { |
9c02b525 | 2783 | /* Pick one at random, out of those which have had events. */ |
d6b0e80f | 2784 | |
9c02b525 | 2785 | /* First see how many events we have. */ |
d3a70e03 TT |
2786 | iterate_over_lwps (filter, |
2787 | [&] (struct lwp_info *info) | |
2788 | { | |
2789 | return count_events_callback (info, &num_events); | |
2790 | }); | |
8bf3b159 | 2791 | gdb_assert (num_events > 0); |
d6b0e80f | 2792 | |
9c02b525 PA |
2793 | /* Now randomly pick a LWP out of those that have had |
2794 | events. */ | |
d6b0e80f AC |
2795 | random_selector = (int) |
2796 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
2797 | ||
9327494e SM |
2798 | if (num_events > 1) |
2799 | linux_nat_debug_printf ("Found %d events, selecting #%d", | |
2800 | num_events, random_selector); | |
d6b0e80f | 2801 | |
d3a70e03 TT |
2802 | event_lp |
2803 | = (iterate_over_lwps | |
2804 | (filter, | |
2805 | [&] (struct lwp_info *info) | |
2806 | { | |
2807 | return select_event_lwp_callback (info, | |
2808 | &random_selector); | |
2809 | })); | |
d6b0e80f AC |
2810 | } |
2811 | ||
2812 | if (event_lp != NULL) | |
2813 | { | |
2814 | /* Switch the event LWP. */ | |
2815 | *orig_lp = event_lp; | |
2816 | *status = event_lp->status; | |
2817 | } | |
2818 | ||
2819 | /* Flush the wait status for the event LWP. */ | |
2820 | (*orig_lp)->status = 0; | |
2821 | } | |
2822 | ||
2823 | /* Return non-zero if LP has been resumed. */ | |
2824 | ||
2825 | static int | |
d3a70e03 | 2826 | resumed_callback (struct lwp_info *lp) |
d6b0e80f AC |
2827 | { |
2828 | return lp->resumed; | |
2829 | } | |
2830 | ||
02f3fc28 | 2831 | /* Check if we should go on and pass this event to common code. |
12d9289a | 2832 | |
897608ed SM |
2833 | If so, save the status to the lwp_info structure associated to LWPID. */ |
2834 | ||
2835 | static void | |
9c02b525 | 2836 | linux_nat_filter_event (int lwpid, int status) |
02f3fc28 PA |
2837 | { |
2838 | struct lwp_info *lp; | |
89a5711c | 2839 | int event = linux_ptrace_get_extended_event (status); |
02f3fc28 | 2840 | |
f2907e49 | 2841 | lp = find_lwp_pid (ptid_t (lwpid)); |
02f3fc28 PA |
2842 | |
2843 | /* Check for stop events reported by a process we didn't already | |
2844 | know about - anything not already in our LWP list. | |
2845 | ||
2846 | If we're expecting to receive stopped processes after | |
2847 | fork, vfork, and clone events, then we'll just add the | |
2848 | new one to our list and go back to waiting for the event | |
2849 | to be reported - the stopped process might be returned | |
0e5bf2a8 PA |
2850 | from waitpid before or after the event is. |
2851 | ||
2852 | But note the case of a non-leader thread exec'ing after the | |
2853 | leader having exited, and gone from our lists. The non-leader | |
2854 | thread changes its tid to the tgid. */ | |
2855 | ||
2856 | if (WIFSTOPPED (status) && lp == NULL | |
89a5711c | 2857 | && (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC)) |
0e5bf2a8 PA |
2858 | { |
2859 | /* A multi-thread exec after we had seen the leader exiting. */ | |
9327494e | 2860 | linux_nat_debug_printf ("Re-adding thread group leader LWP %d.", lwpid); |
0e5bf2a8 | 2861 | |
fd79271b | 2862 | lp = add_lwp (ptid_t (lwpid, lwpid, 0)); |
0e5bf2a8 PA |
2863 | lp->stopped = 1; |
2864 | lp->resumed = 1; | |
5b6d1e4f | 2865 | add_thread (linux_target, lp->ptid); |
0e5bf2a8 PA |
2866 | } |
2867 | ||
02f3fc28 PA |
2868 | if (WIFSTOPPED (status) && !lp) |
2869 | { | |
9327494e | 2870 | linux_nat_debug_printf ("saving LWP %ld status %s in stopped_pids list", |
8d06918f | 2871 | (long) lwpid, status_to_str (status).c_str ()); |
84636d28 | 2872 | add_to_pid_list (&stopped_pids, lwpid, status); |
897608ed | 2873 | return; |
02f3fc28 PA |
2874 | } |
2875 | ||
2876 | /* Make sure we don't report an event for the exit of an LWP not in | |
1777feb0 | 2877 | our list, i.e. not part of the current process. This can happen |
fd62cb89 | 2878 | if we detach from a program we originally forked and then it |
02f3fc28 PA |
2879 | exits. */ |
2880 | if (!WIFSTOPPED (status) && !lp) | |
897608ed | 2881 | return; |
02f3fc28 | 2882 | |
8817a6f2 PA |
2883 | /* This LWP is stopped now. (And if dead, this prevents it from |
2884 | ever being continued.) */ | |
2885 | lp->stopped = 1; | |
2886 | ||
8784d563 PA |
2887 | if (WIFSTOPPED (status) && lp->must_set_ptrace_flags) |
2888 | { | |
5b6d1e4f | 2889 | inferior *inf = find_inferior_pid (linux_target, lp->ptid.pid ()); |
de0d863e | 2890 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 2891 | |
e38504b3 | 2892 | linux_enable_event_reporting (lp->ptid.lwp (), options); |
8784d563 PA |
2893 | lp->must_set_ptrace_flags = 0; |
2894 | } | |
2895 | ||
ca2163eb PA |
2896 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2897 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2898 | { | |
2899 | /* No longer need the sysgood bit. The ptrace event ends up | |
2900 | recorded in lp->waitstatus if we care for it. We can carry | |
2901 | on handling the event like a regular SIGTRAP from here | |
2902 | on. */ | |
2903 | status = W_STOPCODE (SIGTRAP); | |
2904 | if (linux_handle_syscall_trap (lp, 0)) | |
897608ed | 2905 | return; |
ca2163eb | 2906 | } |
bfd09d20 JS |
2907 | else |
2908 | { | |
2909 | /* Almost all other ptrace-stops are known to be outside of system | |
2910 | calls, with further exceptions in linux_handle_extended_wait. */ | |
2911 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2912 | } | |
02f3fc28 | 2913 | |
ca2163eb | 2914 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2915 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2916 | && linux_is_extended_waitstatus (status)) | |
02f3fc28 | 2917 | { |
9327494e SM |
2918 | linux_nat_debug_printf ("Handling extended status 0x%06x", status); |
2919 | ||
4dd63d48 | 2920 | if (linux_handle_extended_wait (lp, status)) |
897608ed | 2921 | return; |
02f3fc28 PA |
2922 | } |
2923 | ||
2924 | /* Check if the thread has exited. */ | |
9c02b525 PA |
2925 | if (WIFEXITED (status) || WIFSIGNALED (status)) |
2926 | { | |
aa01bd36 | 2927 | if (!report_thread_events |
e99b03dc | 2928 | && num_lwps (lp->ptid.pid ()) > 1) |
02f3fc28 | 2929 | { |
9327494e SM |
2930 | linux_nat_debug_printf ("%s exited.", |
2931 | target_pid_to_str (lp->ptid).c_str ()); | |
9c02b525 | 2932 | |
4a6ed09b PA |
2933 | /* If there is at least one more LWP, then the exit signal |
2934 | was not the end of the debugged application and should be | |
2935 | ignored. */ | |
2936 | exit_lwp (lp); | |
897608ed | 2937 | return; |
02f3fc28 PA |
2938 | } |
2939 | ||
77598427 PA |
2940 | /* Note that even if the leader was ptrace-stopped, it can still |
2941 | exit, if e.g., some other thread brings down the whole | |
2942 | process (calls `exit'). So don't assert that the lwp is | |
2943 | resumed. */ | |
9327494e SM |
2944 | linux_nat_debug_printf ("LWP %ld exited (resumed=%d)", |
2945 | lp->ptid.lwp (), lp->resumed); | |
02f3fc28 | 2946 | |
9c02b525 PA |
2947 | /* Dead LWP's aren't expected to reported a pending sigstop. */ |
2948 | lp->signalled = 0; | |
2949 | ||
2950 | /* Store the pending event in the waitstatus, because | |
2951 | W_EXITCODE(0,0) == 0. */ | |
2952 | store_waitstatus (&lp->waitstatus, status); | |
897608ed | 2953 | return; |
02f3fc28 PA |
2954 | } |
2955 | ||
02f3fc28 PA |
2956 | /* Make sure we don't report a SIGSTOP that we sent ourselves in |
2957 | an attempt to stop an LWP. */ | |
2958 | if (lp->signalled | |
2959 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) | |
2960 | { | |
02f3fc28 PA |
2961 | lp->signalled = 0; |
2962 | ||
2bf6fb9d | 2963 | if (lp->last_resume_kind == resume_stop) |
25289eb2 | 2964 | { |
9327494e SM |
2965 | linux_nat_debug_printf ("resume_stop SIGSTOP caught for %s.", |
2966 | target_pid_to_str (lp->ptid).c_str ()); | |
2bf6fb9d PA |
2967 | } |
2968 | else | |
2969 | { | |
2970 | /* This is a delayed SIGSTOP. Filter out the event. */ | |
02f3fc28 | 2971 | |
9327494e SM |
2972 | linux_nat_debug_printf |
2973 | ("%s %s, 0, 0 (discard delayed SIGSTOP)", | |
2974 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
2975 | target_pid_to_str (lp->ptid).c_str ()); | |
02f3fc28 | 2976 | |
2bf6fb9d | 2977 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
25289eb2 | 2978 | gdb_assert (lp->resumed); |
897608ed | 2979 | return; |
25289eb2 | 2980 | } |
02f3fc28 PA |
2981 | } |
2982 | ||
57380f4e DJ |
2983 | /* Make sure we don't report a SIGINT that we have already displayed |
2984 | for another thread. */ | |
2985 | if (lp->ignore_sigint | |
2986 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) | |
2987 | { | |
9327494e SM |
2988 | linux_nat_debug_printf ("Delayed SIGINT caught for %s.", |
2989 | target_pid_to_str (lp->ptid).c_str ()); | |
57380f4e DJ |
2990 | |
2991 | /* This is a delayed SIGINT. */ | |
2992 | lp->ignore_sigint = 0; | |
2993 | ||
8a99810d | 2994 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
9327494e SM |
2995 | linux_nat_debug_printf ("%s %s, 0, 0 (discard SIGINT)", |
2996 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
2997 | target_pid_to_str (lp->ptid).c_str ()); | |
57380f4e DJ |
2998 | gdb_assert (lp->resumed); |
2999 | ||
3000 | /* Discard the event. */ | |
897608ed | 3001 | return; |
57380f4e DJ |
3002 | } |
3003 | ||
9c02b525 PA |
3004 | /* Don't report signals that GDB isn't interested in, such as |
3005 | signals that are neither printed nor stopped upon. Stopping all | |
7da6a5b9 | 3006 | threads can be a bit time-consuming, so if we want decent |
9c02b525 PA |
3007 | performance with heavily multi-threaded programs, especially when |
3008 | they're using a high frequency timer, we'd better avoid it if we | |
3009 | can. */ | |
3010 | if (WIFSTOPPED (status)) | |
3011 | { | |
3012 | enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status)); | |
3013 | ||
fbea99ea | 3014 | if (!target_is_non_stop_p ()) |
9c02b525 PA |
3015 | { |
3016 | /* Only do the below in all-stop, as we currently use SIGSTOP | |
3017 | to implement target_stop (see linux_nat_stop) in | |
3018 | non-stop. */ | |
3019 | if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0) | |
3020 | { | |
3021 | /* If ^C/BREAK is typed at the tty/console, SIGINT gets | |
3022 | forwarded to the entire process group, that is, all LWPs | |
3023 | will receive it - unless they're using CLONE_THREAD to | |
3024 | share signals. Since we only want to report it once, we | |
3025 | mark it as ignored for all LWPs except this one. */ | |
d3a70e03 | 3026 | iterate_over_lwps (ptid_t (lp->ptid.pid ()), set_ignore_sigint); |
9c02b525 PA |
3027 | lp->ignore_sigint = 0; |
3028 | } | |
3029 | else | |
3030 | maybe_clear_ignore_sigint (lp); | |
3031 | } | |
3032 | ||
3033 | /* When using hardware single-step, we need to report every signal. | |
c9587f88 | 3034 | Otherwise, signals in pass_mask may be short-circuited |
d8c06f22 AB |
3035 | except signals that might be caused by a breakpoint, or SIGSTOP |
3036 | if we sent the SIGSTOP and are waiting for it to arrive. */ | |
9c02b525 | 3037 | if (!lp->step |
c9587f88 | 3038 | && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status)) |
d8c06f22 | 3039 | && (WSTOPSIG (status) != SIGSTOP |
5b6d1e4f | 3040 | || !find_thread_ptid (linux_target, lp->ptid)->stop_requested) |
c9587f88 | 3041 | && !linux_wstatus_maybe_breakpoint (status)) |
9c02b525 PA |
3042 | { |
3043 | linux_resume_one_lwp (lp, lp->step, signo); | |
9327494e SM |
3044 | linux_nat_debug_printf |
3045 | ("%s %s, %s (preempt 'handle')", | |
3046 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3047 | target_pid_to_str (lp->ptid).c_str (), | |
3048 | (signo != GDB_SIGNAL_0 | |
3049 | ? strsignal (gdb_signal_to_host (signo)) : "0")); | |
897608ed | 3050 | return; |
9c02b525 PA |
3051 | } |
3052 | } | |
3053 | ||
02f3fc28 PA |
3054 | /* An interesting event. */ |
3055 | gdb_assert (lp); | |
ca2163eb | 3056 | lp->status = status; |
e7ad2f14 | 3057 | save_stop_reason (lp); |
02f3fc28 PA |
3058 | } |
3059 | ||
0e5bf2a8 PA |
3060 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
3061 | their exits until all other threads in the group have exited. */ | |
3062 | ||
3063 | static void | |
3064 | check_zombie_leaders (void) | |
3065 | { | |
08036331 | 3066 | for (inferior *inf : all_inferiors ()) |
0e5bf2a8 PA |
3067 | { |
3068 | struct lwp_info *leader_lp; | |
3069 | ||
3070 | if (inf->pid == 0) | |
3071 | continue; | |
3072 | ||
f2907e49 | 3073 | leader_lp = find_lwp_pid (ptid_t (inf->pid)); |
0e5bf2a8 PA |
3074 | if (leader_lp != NULL |
3075 | /* Check if there are other threads in the group, as we may | |
3076 | have raced with the inferior simply exiting. */ | |
3077 | && num_lwps (inf->pid) > 1 | |
5f572dec | 3078 | && linux_proc_pid_is_zombie (inf->pid)) |
0e5bf2a8 | 3079 | { |
9327494e SM |
3080 | linux_nat_debug_printf ("Thread group leader %d zombie " |
3081 | "(it exited, or another thread execd).", | |
3082 | inf->pid); | |
0e5bf2a8 PA |
3083 | |
3084 | /* A leader zombie can mean one of two things: | |
3085 | ||
3086 | - It exited, and there's an exit status pending | |
3087 | available, or only the leader exited (not the whole | |
3088 | program). In the latter case, we can't waitpid the | |
3089 | leader's exit status until all other threads are gone. | |
3090 | ||
3091 | - There are 3 or more threads in the group, and a thread | |
4a6ed09b PA |
3092 | other than the leader exec'd. See comments on exec |
3093 | events at the top of the file. We could try | |
0e5bf2a8 PA |
3094 | distinguishing the exit and exec cases, by waiting once |
3095 | more, and seeing if something comes out, but it doesn't | |
3096 | sound useful. The previous leader _does_ go away, and | |
3097 | we'll re-add the new one once we see the exec event | |
3098 | (which is just the same as what would happen if the | |
3099 | previous leader did exit voluntarily before some other | |
3100 | thread execs). */ | |
3101 | ||
9327494e | 3102 | linux_nat_debug_printf ("Thread group leader %d vanished.", inf->pid); |
0e5bf2a8 PA |
3103 | exit_lwp (leader_lp); |
3104 | } | |
3105 | } | |
3106 | } | |
3107 | ||
aa01bd36 PA |
3108 | /* Convenience function that is called when the kernel reports an exit |
3109 | event. This decides whether to report the event to GDB as a | |
3110 | process exit event, a thread exit event, or to suppress the | |
3111 | event. */ | |
3112 | ||
3113 | static ptid_t | |
3114 | filter_exit_event (struct lwp_info *event_child, | |
3115 | struct target_waitstatus *ourstatus) | |
3116 | { | |
3117 | ptid_t ptid = event_child->ptid; | |
3118 | ||
e99b03dc | 3119 | if (num_lwps (ptid.pid ()) > 1) |
aa01bd36 PA |
3120 | { |
3121 | if (report_thread_events) | |
3122 | ourstatus->kind = TARGET_WAITKIND_THREAD_EXITED; | |
3123 | else | |
3124 | ourstatus->kind = TARGET_WAITKIND_IGNORE; | |
3125 | ||
3126 | exit_lwp (event_child); | |
3127 | } | |
3128 | ||
3129 | return ptid; | |
3130 | } | |
3131 | ||
d6b0e80f | 3132 | static ptid_t |
f6ac5f3d | 3133 | linux_nat_wait_1 (ptid_t ptid, struct target_waitstatus *ourstatus, |
b60cea74 | 3134 | target_wait_flags target_options) |
d6b0e80f | 3135 | { |
fc9b8e47 | 3136 | sigset_t prev_mask; |
4b60df3d | 3137 | enum resume_kind last_resume_kind; |
12d9289a | 3138 | struct lwp_info *lp; |
12d9289a | 3139 | int status; |
d6b0e80f | 3140 | |
9327494e | 3141 | linux_nat_debug_printf ("enter"); |
b84876c2 | 3142 | |
f973ed9c DJ |
3143 | /* The first time we get here after starting a new inferior, we may |
3144 | not have added it to the LWP list yet - this is the earliest | |
3145 | moment at which we know its PID. */ | |
677c92fe | 3146 | if (ptid.is_pid () && find_lwp_pid (ptid) == nullptr) |
f973ed9c | 3147 | { |
677c92fe | 3148 | ptid_t lwp_ptid (ptid.pid (), ptid.pid ()); |
27c9d204 | 3149 | |
677c92fe SM |
3150 | /* Upgrade the main thread's ptid. */ |
3151 | thread_change_ptid (linux_target, ptid, lwp_ptid); | |
3152 | lp = add_initial_lwp (lwp_ptid); | |
f973ed9c DJ |
3153 | lp->resumed = 1; |
3154 | } | |
3155 | ||
12696c10 | 3156 | /* Make sure SIGCHLD is blocked until the sigsuspend below. */ |
7feb7d06 | 3157 | block_child_signals (&prev_mask); |
d6b0e80f | 3158 | |
d6b0e80f | 3159 | /* First check if there is a LWP with a wait status pending. */ |
d3a70e03 | 3160 | lp = iterate_over_lwps (ptid, status_callback); |
8a99810d | 3161 | if (lp != NULL) |
d6b0e80f | 3162 | { |
9327494e | 3163 | linux_nat_debug_printf ("Using pending wait status %s for %s.", |
8d06918f | 3164 | status_to_str (lp->status).c_str (), |
9327494e | 3165 | target_pid_to_str (lp->ptid).c_str ()); |
d6b0e80f AC |
3166 | } |
3167 | ||
9c02b525 PA |
3168 | /* But if we don't find a pending event, we'll have to wait. Always |
3169 | pull all events out of the kernel. We'll randomly select an | |
3170 | event LWP out of all that have events, to prevent starvation. */ | |
7feb7d06 | 3171 | |
d90e17a7 | 3172 | while (lp == NULL) |
d6b0e80f AC |
3173 | { |
3174 | pid_t lwpid; | |
3175 | ||
0e5bf2a8 PA |
3176 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
3177 | quirks: | |
3178 | ||
3179 | - If the thread group leader exits while other threads in the | |
3180 | thread group still exist, waitpid(TGID, ...) hangs. That | |
3181 | waitpid won't return an exit status until the other threads | |
85102364 | 3182 | in the group are reaped. |
0e5bf2a8 PA |
3183 | |
3184 | - When a non-leader thread execs, that thread just vanishes | |
3185 | without reporting an exit (so we'd hang if we waited for it | |
3186 | explicitly in that case). The exec event is reported to | |
3187 | the TGID pid. */ | |
3188 | ||
3189 | errno = 0; | |
4a6ed09b | 3190 | lwpid = my_waitpid (-1, &status, __WALL | WNOHANG); |
0e5bf2a8 | 3191 | |
9327494e SM |
3192 | linux_nat_debug_printf ("waitpid(-1, ...) returned %d, %s", |
3193 | lwpid, | |
3194 | errno ? safe_strerror (errno) : "ERRNO-OK"); | |
b84876c2 | 3195 | |
d6b0e80f AC |
3196 | if (lwpid > 0) |
3197 | { | |
9327494e | 3198 | linux_nat_debug_printf ("waitpid %ld received %s", |
8d06918f SM |
3199 | (long) lwpid, |
3200 | status_to_str (status).c_str ()); | |
d6b0e80f | 3201 | |
9c02b525 | 3202 | linux_nat_filter_event (lwpid, status); |
0e5bf2a8 PA |
3203 | /* Retry until nothing comes out of waitpid. A single |
3204 | SIGCHLD can indicate more than one child stopped. */ | |
3205 | continue; | |
d6b0e80f AC |
3206 | } |
3207 | ||
20ba1ce6 PA |
3208 | /* Now that we've pulled all events out of the kernel, resume |
3209 | LWPs that don't have an interesting event to report. */ | |
3210 | iterate_over_lwps (minus_one_ptid, | |
d3a70e03 TT |
3211 | [] (struct lwp_info *info) |
3212 | { | |
3213 | return resume_stopped_resumed_lwps (info, minus_one_ptid); | |
3214 | }); | |
20ba1ce6 PA |
3215 | |
3216 | /* ... and find an LWP with a status to report to the core, if | |
3217 | any. */ | |
d3a70e03 | 3218 | lp = iterate_over_lwps (ptid, status_callback); |
9c02b525 PA |
3219 | if (lp != NULL) |
3220 | break; | |
3221 | ||
0e5bf2a8 PA |
3222 | /* Check for zombie thread group leaders. Those can't be reaped |
3223 | until all other threads in the thread group are. */ | |
3224 | check_zombie_leaders (); | |
d6b0e80f | 3225 | |
0e5bf2a8 PA |
3226 | /* If there are no resumed children left, bail. We'd be stuck |
3227 | forever in the sigsuspend call below otherwise. */ | |
d3a70e03 | 3228 | if (iterate_over_lwps (ptid, resumed_callback) == NULL) |
0e5bf2a8 | 3229 | { |
9327494e | 3230 | linux_nat_debug_printf ("exit (no resumed LWP)"); |
b84876c2 | 3231 | |
0e5bf2a8 | 3232 | ourstatus->kind = TARGET_WAITKIND_NO_RESUMED; |
b84876c2 | 3233 | |
0e5bf2a8 PA |
3234 | restore_child_signals_mask (&prev_mask); |
3235 | return minus_one_ptid; | |
d6b0e80f | 3236 | } |
28736962 | 3237 | |
0e5bf2a8 PA |
3238 | /* No interesting event to report to the core. */ |
3239 | ||
3240 | if (target_options & TARGET_WNOHANG) | |
3241 | { | |
9327494e | 3242 | linux_nat_debug_printf ("exit (ignore)"); |
28736962 | 3243 | |
0e5bf2a8 | 3244 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
28736962 PA |
3245 | restore_child_signals_mask (&prev_mask); |
3246 | return minus_one_ptid; | |
3247 | } | |
d6b0e80f AC |
3248 | |
3249 | /* We shouldn't end up here unless we want to try again. */ | |
d90e17a7 | 3250 | gdb_assert (lp == NULL); |
0e5bf2a8 PA |
3251 | |
3252 | /* Block until we get an event reported with SIGCHLD. */ | |
9c3a5d93 | 3253 | wait_for_signal (); |
d6b0e80f AC |
3254 | } |
3255 | ||
d6b0e80f AC |
3256 | gdb_assert (lp); |
3257 | ||
ca2163eb PA |
3258 | status = lp->status; |
3259 | lp->status = 0; | |
3260 | ||
fbea99ea | 3261 | if (!target_is_non_stop_p ()) |
4c28f408 PA |
3262 | { |
3263 | /* Now stop all other LWP's ... */ | |
d3a70e03 | 3264 | iterate_over_lwps (minus_one_ptid, stop_callback); |
4c28f408 PA |
3265 | |
3266 | /* ... and wait until all of them have reported back that | |
3267 | they're no longer running. */ | |
d3a70e03 | 3268 | iterate_over_lwps (minus_one_ptid, stop_wait_callback); |
9c02b525 PA |
3269 | } |
3270 | ||
3271 | /* If we're not waiting for a specific LWP, choose an event LWP from | |
3272 | among those that have had events. Giving equal priority to all | |
3273 | LWPs that have had events helps prevent starvation. */ | |
d7e15655 | 3274 | if (ptid == minus_one_ptid || ptid.is_pid ()) |
9c02b525 PA |
3275 | select_event_lwp (ptid, &lp, &status); |
3276 | ||
3277 | gdb_assert (lp != NULL); | |
3278 | ||
3279 | /* Now that we've selected our final event LWP, un-adjust its PC if | |
faf09f01 PA |
3280 | it was a software breakpoint, and we can't reliably support the |
3281 | "stopped by software breakpoint" stop reason. */ | |
3282 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT | |
3283 | && !USE_SIGTRAP_SIGINFO) | |
9c02b525 | 3284 | { |
5b6d1e4f | 3285 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 3286 | struct gdbarch *gdbarch = regcache->arch (); |
527a273a | 3287 | int decr_pc = gdbarch_decr_pc_after_break (gdbarch); |
4c28f408 | 3288 | |
9c02b525 PA |
3289 | if (decr_pc != 0) |
3290 | { | |
3291 | CORE_ADDR pc; | |
d6b0e80f | 3292 | |
9c02b525 PA |
3293 | pc = regcache_read_pc (regcache); |
3294 | regcache_write_pc (regcache, pc + decr_pc); | |
3295 | } | |
3296 | } | |
e3e9f5a2 | 3297 | |
9c02b525 PA |
3298 | /* We'll need this to determine whether to report a SIGSTOP as |
3299 | GDB_SIGNAL_0. Need to take a copy because resume_clear_callback | |
3300 | clears it. */ | |
3301 | last_resume_kind = lp->last_resume_kind; | |
4b60df3d | 3302 | |
fbea99ea | 3303 | if (!target_is_non_stop_p ()) |
9c02b525 | 3304 | { |
e3e9f5a2 PA |
3305 | /* In all-stop, from the core's perspective, all LWPs are now |
3306 | stopped until a new resume action is sent over. */ | |
d3a70e03 | 3307 | iterate_over_lwps (minus_one_ptid, resume_clear_callback); |
e3e9f5a2 PA |
3308 | } |
3309 | else | |
25289eb2 | 3310 | { |
d3a70e03 | 3311 | resume_clear_callback (lp); |
25289eb2 | 3312 | } |
d6b0e80f | 3313 | |
135340af | 3314 | if (linux_target->low_status_is_event (status)) |
d6b0e80f | 3315 | { |
9327494e SM |
3316 | linux_nat_debug_printf ("trap ptid is %s.", |
3317 | target_pid_to_str (lp->ptid).c_str ()); | |
d6b0e80f | 3318 | } |
d6b0e80f AC |
3319 | |
3320 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
3321 | { | |
3322 | *ourstatus = lp->waitstatus; | |
3323 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
3324 | } | |
3325 | else | |
3326 | store_waitstatus (ourstatus, status); | |
3327 | ||
9327494e | 3328 | linux_nat_debug_printf ("exit"); |
b84876c2 | 3329 | |
7feb7d06 | 3330 | restore_child_signals_mask (&prev_mask); |
1e225492 | 3331 | |
4b60df3d | 3332 | if (last_resume_kind == resume_stop |
25289eb2 PA |
3333 | && ourstatus->kind == TARGET_WAITKIND_STOPPED |
3334 | && WSTOPSIG (status) == SIGSTOP) | |
3335 | { | |
3336 | /* A thread that has been requested to stop by GDB with | |
3337 | target_stop, and it stopped cleanly, so report as SIG0. The | |
3338 | use of SIGSTOP is an implementation detail. */ | |
a493e3e2 | 3339 | ourstatus->value.sig = GDB_SIGNAL_0; |
25289eb2 PA |
3340 | } |
3341 | ||
1e225492 JK |
3342 | if (ourstatus->kind == TARGET_WAITKIND_EXITED |
3343 | || ourstatus->kind == TARGET_WAITKIND_SIGNALLED) | |
3344 | lp->core = -1; | |
3345 | else | |
2e794194 | 3346 | lp->core = linux_common_core_of_thread (lp->ptid); |
1e225492 | 3347 | |
aa01bd36 PA |
3348 | if (ourstatus->kind == TARGET_WAITKIND_EXITED) |
3349 | return filter_exit_event (lp, ourstatus); | |
3350 | ||
f973ed9c | 3351 | return lp->ptid; |
d6b0e80f AC |
3352 | } |
3353 | ||
e3e9f5a2 PA |
3354 | /* Resume LWPs that are currently stopped without any pending status |
3355 | to report, but are resumed from the core's perspective. */ | |
3356 | ||
3357 | static int | |
d3a70e03 | 3358 | resume_stopped_resumed_lwps (struct lwp_info *lp, const ptid_t wait_ptid) |
e3e9f5a2 | 3359 | { |
4dd63d48 PA |
3360 | if (!lp->stopped) |
3361 | { | |
9327494e SM |
3362 | linux_nat_debug_printf ("NOT resuming LWP %s, not stopped", |
3363 | target_pid_to_str (lp->ptid).c_str ()); | |
4dd63d48 PA |
3364 | } |
3365 | else if (!lp->resumed) | |
3366 | { | |
9327494e SM |
3367 | linux_nat_debug_printf ("NOT resuming LWP %s, not resumed", |
3368 | target_pid_to_str (lp->ptid).c_str ()); | |
4dd63d48 PA |
3369 | } |
3370 | else if (lwp_status_pending_p (lp)) | |
3371 | { | |
9327494e SM |
3372 | linux_nat_debug_printf ("NOT resuming LWP %s, has pending status", |
3373 | target_pid_to_str (lp->ptid).c_str ()); | |
4dd63d48 PA |
3374 | } |
3375 | else | |
e3e9f5a2 | 3376 | { |
5b6d1e4f | 3377 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 3378 | struct gdbarch *gdbarch = regcache->arch (); |
336060f3 | 3379 | |
a70b8144 | 3380 | try |
e3e9f5a2 | 3381 | { |
23f238d3 PA |
3382 | CORE_ADDR pc = regcache_read_pc (regcache); |
3383 | int leave_stopped = 0; | |
e3e9f5a2 | 3384 | |
23f238d3 PA |
3385 | /* Don't bother if there's a breakpoint at PC that we'd hit |
3386 | immediately, and we're not waiting for this LWP. */ | |
d3a70e03 | 3387 | if (!lp->ptid.matches (wait_ptid)) |
23f238d3 | 3388 | { |
a01bda52 | 3389 | if (breakpoint_inserted_here_p (regcache->aspace (), pc)) |
23f238d3 PA |
3390 | leave_stopped = 1; |
3391 | } | |
e3e9f5a2 | 3392 | |
23f238d3 PA |
3393 | if (!leave_stopped) |
3394 | { | |
9327494e SM |
3395 | linux_nat_debug_printf |
3396 | ("resuming stopped-resumed LWP %s at %s: step=%d", | |
3397 | target_pid_to_str (lp->ptid).c_str (), paddress (gdbarch, pc), | |
3398 | lp->step); | |
23f238d3 PA |
3399 | |
3400 | linux_resume_one_lwp_throw (lp, lp->step, GDB_SIGNAL_0); | |
3401 | } | |
3402 | } | |
230d2906 | 3403 | catch (const gdb_exception_error &ex) |
23f238d3 PA |
3404 | { |
3405 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 3406 | throw; |
23f238d3 | 3407 | } |
e3e9f5a2 PA |
3408 | } |
3409 | ||
3410 | return 0; | |
3411 | } | |
3412 | ||
f6ac5f3d PA |
3413 | ptid_t |
3414 | linux_nat_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus, | |
b60cea74 | 3415 | target_wait_flags target_options) |
7feb7d06 PA |
3416 | { |
3417 | ptid_t event_ptid; | |
3418 | ||
9327494e SM |
3419 | linux_nat_debug_printf ("[%s], [%s]", target_pid_to_str (ptid).c_str (), |
3420 | target_options_to_string (target_options).c_str ()); | |
7feb7d06 PA |
3421 | |
3422 | /* Flush the async file first. */ | |
d9d41e78 | 3423 | if (target_is_async_p ()) |
7feb7d06 PA |
3424 | async_file_flush (); |
3425 | ||
e3e9f5a2 PA |
3426 | /* Resume LWPs that are currently stopped without any pending status |
3427 | to report, but are resumed from the core's perspective. LWPs get | |
3428 | in this state if we find them stopping at a time we're not | |
3429 | interested in reporting the event (target_wait on a | |
3430 | specific_process, for example, see linux_nat_wait_1), and | |
3431 | meanwhile the event became uninteresting. Don't bother resuming | |
3432 | LWPs we're not going to wait for if they'd stop immediately. */ | |
fbea99ea | 3433 | if (target_is_non_stop_p ()) |
d3a70e03 TT |
3434 | iterate_over_lwps (minus_one_ptid, |
3435 | [=] (struct lwp_info *info) | |
3436 | { | |
3437 | return resume_stopped_resumed_lwps (info, ptid); | |
3438 | }); | |
e3e9f5a2 | 3439 | |
f6ac5f3d | 3440 | event_ptid = linux_nat_wait_1 (ptid, ourstatus, target_options); |
7feb7d06 PA |
3441 | |
3442 | /* If we requested any event, and something came out, assume there | |
3443 | may be more. If we requested a specific lwp or process, also | |
3444 | assume there may be more. */ | |
d9d41e78 | 3445 | if (target_is_async_p () |
6953d224 PA |
3446 | && ((ourstatus->kind != TARGET_WAITKIND_IGNORE |
3447 | && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED) | |
d7e15655 | 3448 | || ptid != minus_one_ptid)) |
7feb7d06 PA |
3449 | async_file_mark (); |
3450 | ||
7feb7d06 PA |
3451 | return event_ptid; |
3452 | } | |
3453 | ||
1d2736d4 PA |
3454 | /* Kill one LWP. */ |
3455 | ||
3456 | static void | |
3457 | kill_one_lwp (pid_t pid) | |
d6b0e80f | 3458 | { |
ed731959 JK |
3459 | /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
3460 | ||
3461 | errno = 0; | |
1d2736d4 | 3462 | kill_lwp (pid, SIGKILL); |
9327494e | 3463 | |
ed731959 | 3464 | if (debug_linux_nat) |
57745c90 PA |
3465 | { |
3466 | int save_errno = errno; | |
3467 | ||
9327494e SM |
3468 | linux_nat_debug_printf |
3469 | ("kill (SIGKILL) %ld, 0, 0 (%s)", (long) pid, | |
3470 | save_errno != 0 ? safe_strerror (save_errno) : "OK"); | |
57745c90 | 3471 | } |
ed731959 JK |
3472 | |
3473 | /* Some kernels ignore even SIGKILL for processes under ptrace. */ | |
3474 | ||
d6b0e80f | 3475 | errno = 0; |
1d2736d4 | 3476 | ptrace (PTRACE_KILL, pid, 0, 0); |
d6b0e80f | 3477 | if (debug_linux_nat) |
57745c90 PA |
3478 | { |
3479 | int save_errno = errno; | |
3480 | ||
9327494e SM |
3481 | linux_nat_debug_printf |
3482 | ("PTRACE_KILL %ld, 0, 0 (%s)", (long) pid, | |
3483 | save_errno ? safe_strerror (save_errno) : "OK"); | |
57745c90 | 3484 | } |
d6b0e80f AC |
3485 | } |
3486 | ||
1d2736d4 PA |
3487 | /* Wait for an LWP to die. */ |
3488 | ||
3489 | static void | |
3490 | kill_wait_one_lwp (pid_t pid) | |
d6b0e80f | 3491 | { |
1d2736d4 | 3492 | pid_t res; |
d6b0e80f AC |
3493 | |
3494 | /* We must make sure that there are no pending events (delayed | |
3495 | SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current | |
3496 | program doesn't interfere with any following debugging session. */ | |
3497 | ||
d6b0e80f AC |
3498 | do |
3499 | { | |
1d2736d4 PA |
3500 | res = my_waitpid (pid, NULL, __WALL); |
3501 | if (res != (pid_t) -1) | |
d6b0e80f | 3502 | { |
9327494e SM |
3503 | linux_nat_debug_printf ("wait %ld received unknown.", (long) pid); |
3504 | ||
4a6ed09b PA |
3505 | /* The Linux kernel sometimes fails to kill a thread |
3506 | completely after PTRACE_KILL; that goes from the stop | |
3507 | point in do_fork out to the one in get_signal_to_deliver | |
3508 | and waits again. So kill it again. */ | |
1d2736d4 | 3509 | kill_one_lwp (pid); |
d6b0e80f AC |
3510 | } |
3511 | } | |
1d2736d4 PA |
3512 | while (res == pid); |
3513 | ||
3514 | gdb_assert (res == -1 && errno == ECHILD); | |
3515 | } | |
3516 | ||
3517 | /* Callback for iterate_over_lwps. */ | |
d6b0e80f | 3518 | |
1d2736d4 | 3519 | static int |
d3a70e03 | 3520 | kill_callback (struct lwp_info *lp) |
1d2736d4 | 3521 | { |
e38504b3 | 3522 | kill_one_lwp (lp->ptid.lwp ()); |
d6b0e80f AC |
3523 | return 0; |
3524 | } | |
3525 | ||
1d2736d4 PA |
3526 | /* Callback for iterate_over_lwps. */ |
3527 | ||
3528 | static int | |
d3a70e03 | 3529 | kill_wait_callback (struct lwp_info *lp) |
1d2736d4 | 3530 | { |
e38504b3 | 3531 | kill_wait_one_lwp (lp->ptid.lwp ()); |
1d2736d4 PA |
3532 | return 0; |
3533 | } | |
3534 | ||
3535 | /* Kill the fork children of any threads of inferior INF that are | |
3536 | stopped at a fork event. */ | |
3537 | ||
3538 | static void | |
3539 | kill_unfollowed_fork_children (struct inferior *inf) | |
3540 | { | |
08036331 PA |
3541 | for (thread_info *thread : inf->non_exited_threads ()) |
3542 | { | |
3543 | struct target_waitstatus *ws = &thread->pending_follow; | |
1d2736d4 | 3544 | |
08036331 PA |
3545 | if (ws->kind == TARGET_WAITKIND_FORKED |
3546 | || ws->kind == TARGET_WAITKIND_VFORKED) | |
3547 | { | |
3548 | ptid_t child_ptid = ws->value.related_pid; | |
3549 | int child_pid = child_ptid.pid (); | |
3550 | int child_lwp = child_ptid.lwp (); | |
3551 | ||
3552 | kill_one_lwp (child_lwp); | |
3553 | kill_wait_one_lwp (child_lwp); | |
3554 | ||
3555 | /* Let the arch-specific native code know this process is | |
3556 | gone. */ | |
3557 | linux_target->low_forget_process (child_pid); | |
3558 | } | |
3559 | } | |
1d2736d4 PA |
3560 | } |
3561 | ||
f6ac5f3d PA |
3562 | void |
3563 | linux_nat_target::kill () | |
d6b0e80f | 3564 | { |
f973ed9c DJ |
3565 | /* If we're stopped while forking and we haven't followed yet, |
3566 | kill the other task. We need to do this first because the | |
3567 | parent will be sleeping if this is a vfork. */ | |
1d2736d4 | 3568 | kill_unfollowed_fork_children (current_inferior ()); |
f973ed9c DJ |
3569 | |
3570 | if (forks_exist_p ()) | |
7feb7d06 | 3571 | linux_fork_killall (); |
f973ed9c DJ |
3572 | else |
3573 | { | |
e99b03dc | 3574 | ptid_t ptid = ptid_t (inferior_ptid.pid ()); |
e0881a8e | 3575 | |
4c28f408 | 3576 | /* Stop all threads before killing them, since ptrace requires |
30baf67b | 3577 | that the thread is stopped to successfully PTRACE_KILL. */ |
d3a70e03 | 3578 | iterate_over_lwps (ptid, stop_callback); |
4c28f408 PA |
3579 | /* ... and wait until all of them have reported back that |
3580 | they're no longer running. */ | |
d3a70e03 | 3581 | iterate_over_lwps (ptid, stop_wait_callback); |
4c28f408 | 3582 | |
f973ed9c | 3583 | /* Kill all LWP's ... */ |
d3a70e03 | 3584 | iterate_over_lwps (ptid, kill_callback); |
f973ed9c DJ |
3585 | |
3586 | /* ... and wait until we've flushed all events. */ | |
d3a70e03 | 3587 | iterate_over_lwps (ptid, kill_wait_callback); |
f973ed9c DJ |
3588 | } |
3589 | ||
bc1e6c81 | 3590 | target_mourn_inferior (inferior_ptid); |
d6b0e80f AC |
3591 | } |
3592 | ||
f6ac5f3d PA |
3593 | void |
3594 | linux_nat_target::mourn_inferior () | |
d6b0e80f | 3595 | { |
e99b03dc | 3596 | int pid = inferior_ptid.pid (); |
26cb8b7c PA |
3597 | |
3598 | purge_lwp_list (pid); | |
d6b0e80f | 3599 | |
05c06f31 PA |
3600 | /* Close the /proc/<pid>/mem file if it was open for this |
3601 | inferior. */ | |
3602 | maybe_close_proc_mem_file (pid); | |
3603 | ||
f973ed9c | 3604 | if (! forks_exist_p ()) |
d90e17a7 | 3605 | /* Normal case, no other forks available. */ |
f6ac5f3d | 3606 | inf_ptrace_target::mourn_inferior (); |
f973ed9c DJ |
3607 | else |
3608 | /* Multi-fork case. The current inferior_ptid has exited, but | |
3609 | there are other viable forks to debug. Delete the exiting | |
3610 | one and context-switch to the first available. */ | |
3611 | linux_fork_mourn_inferior (); | |
26cb8b7c PA |
3612 | |
3613 | /* Let the arch-specific native code know this process is gone. */ | |
135340af | 3614 | linux_target->low_forget_process (pid); |
d6b0e80f AC |
3615 | } |
3616 | ||
5b009018 PA |
3617 | /* Convert a native/host siginfo object, into/from the siginfo in the |
3618 | layout of the inferiors' architecture. */ | |
3619 | ||
3620 | static void | |
a5362b9a | 3621 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
5b009018 | 3622 | { |
135340af PA |
3623 | /* If the low target didn't do anything, then just do a straight |
3624 | memcpy. */ | |
3625 | if (!linux_target->low_siginfo_fixup (siginfo, inf_siginfo, direction)) | |
5b009018 PA |
3626 | { |
3627 | if (direction == 1) | |
a5362b9a | 3628 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
5b009018 | 3629 | else |
a5362b9a | 3630 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
5b009018 PA |
3631 | } |
3632 | } | |
3633 | ||
9b409511 | 3634 | static enum target_xfer_status |
f6ac5f3d | 3635 | linux_xfer_siginfo (enum target_object object, |
dda83cd7 | 3636 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
3637 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
3638 | ULONGEST *xfered_len) | |
4aa995e1 | 3639 | { |
4aa995e1 | 3640 | int pid; |
a5362b9a TS |
3641 | siginfo_t siginfo; |
3642 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; | |
4aa995e1 PA |
3643 | |
3644 | gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO); | |
3645 | gdb_assert (readbuf || writebuf); | |
3646 | ||
e38504b3 | 3647 | pid = inferior_ptid.lwp (); |
4aa995e1 | 3648 | if (pid == 0) |
e99b03dc | 3649 | pid = inferior_ptid.pid (); |
4aa995e1 PA |
3650 | |
3651 | if (offset > sizeof (siginfo)) | |
2ed4b548 | 3652 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3653 | |
3654 | errno = 0; | |
3655 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3656 | if (errno != 0) | |
2ed4b548 | 3657 | return TARGET_XFER_E_IO; |
4aa995e1 | 3658 | |
5b009018 PA |
3659 | /* When GDB is built as a 64-bit application, ptrace writes into |
3660 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
3661 | inferior with a 64-bit GDB should look the same as debugging it | |
3662 | with a 32-bit GDB, we need to convert it. GDB core always sees | |
3663 | the converted layout, so any read/write will have to be done | |
3664 | post-conversion. */ | |
3665 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
3666 | ||
4aa995e1 PA |
3667 | if (offset + len > sizeof (siginfo)) |
3668 | len = sizeof (siginfo) - offset; | |
3669 | ||
3670 | if (readbuf != NULL) | |
5b009018 | 3671 | memcpy (readbuf, inf_siginfo + offset, len); |
4aa995e1 PA |
3672 | else |
3673 | { | |
5b009018 PA |
3674 | memcpy (inf_siginfo + offset, writebuf, len); |
3675 | ||
3676 | /* Convert back to ptrace layout before flushing it out. */ | |
3677 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
3678 | ||
4aa995e1 PA |
3679 | errno = 0; |
3680 | ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3681 | if (errno != 0) | |
2ed4b548 | 3682 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3683 | } |
3684 | ||
9b409511 YQ |
3685 | *xfered_len = len; |
3686 | return TARGET_XFER_OK; | |
4aa995e1 PA |
3687 | } |
3688 | ||
9b409511 | 3689 | static enum target_xfer_status |
f6ac5f3d PA |
3690 | linux_nat_xfer_osdata (enum target_object object, |
3691 | const char *annex, gdb_byte *readbuf, | |
3692 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, | |
3693 | ULONGEST *xfered_len); | |
3694 | ||
f6ac5f3d | 3695 | static enum target_xfer_status |
05c06f31 PA |
3696 | linux_proc_xfer_memory_partial (gdb_byte *readbuf, const gdb_byte *writebuf, |
3697 | ULONGEST offset, LONGEST len, ULONGEST *xfered_len); | |
f6ac5f3d PA |
3698 | |
3699 | enum target_xfer_status | |
3700 | linux_nat_target::xfer_partial (enum target_object object, | |
3701 | const char *annex, gdb_byte *readbuf, | |
3702 | const gdb_byte *writebuf, | |
3703 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) | |
d6b0e80f | 3704 | { |
4aa995e1 | 3705 | if (object == TARGET_OBJECT_SIGNAL_INFO) |
f6ac5f3d | 3706 | return linux_xfer_siginfo (object, annex, readbuf, writebuf, |
9b409511 | 3707 | offset, len, xfered_len); |
4aa995e1 | 3708 | |
c35b1492 PA |
3709 | /* The target is connected but no live inferior is selected. Pass |
3710 | this request down to a lower stratum (e.g., the executable | |
3711 | file). */ | |
d7e15655 | 3712 | if (object == TARGET_OBJECT_MEMORY && inferior_ptid == null_ptid) |
9b409511 | 3713 | return TARGET_XFER_EOF; |
c35b1492 | 3714 | |
f6ac5f3d PA |
3715 | if (object == TARGET_OBJECT_AUXV) |
3716 | return memory_xfer_auxv (this, object, annex, readbuf, writebuf, | |
3717 | offset, len, xfered_len); | |
3718 | ||
3719 | if (object == TARGET_OBJECT_OSDATA) | |
3720 | return linux_nat_xfer_osdata (object, annex, readbuf, writebuf, | |
3721 | offset, len, xfered_len); | |
d6b0e80f | 3722 | |
f6ac5f3d PA |
3723 | if (object == TARGET_OBJECT_MEMORY) |
3724 | { | |
05c06f31 PA |
3725 | /* GDB calculates all addresses in the largest possible address |
3726 | width. The address width must be masked before its final use | |
3727 | by linux_proc_xfer_partial. | |
3728 | ||
3729 | Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ | |
f6ac5f3d PA |
3730 | int addr_bit = gdbarch_addr_bit (target_gdbarch ()); |
3731 | ||
3732 | if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) | |
3733 | offset &= ((ULONGEST) 1 << addr_bit) - 1; | |
f6ac5f3d | 3734 | |
05c06f31 PA |
3735 | return linux_proc_xfer_memory_partial (readbuf, writebuf, |
3736 | offset, len, xfered_len); | |
3737 | } | |
f6ac5f3d PA |
3738 | |
3739 | return inf_ptrace_target::xfer_partial (object, annex, readbuf, writebuf, | |
3740 | offset, len, xfered_len); | |
d6b0e80f AC |
3741 | } |
3742 | ||
57810aa7 | 3743 | bool |
f6ac5f3d | 3744 | linux_nat_target::thread_alive (ptid_t ptid) |
28439f5e | 3745 | { |
4a6ed09b PA |
3746 | /* As long as a PTID is in lwp list, consider it alive. */ |
3747 | return find_lwp_pid (ptid) != NULL; | |
28439f5e PA |
3748 | } |
3749 | ||
8a06aea7 PA |
3750 | /* Implement the to_update_thread_list target method for this |
3751 | target. */ | |
3752 | ||
f6ac5f3d PA |
3753 | void |
3754 | linux_nat_target::update_thread_list () | |
8a06aea7 | 3755 | { |
a6904d5a PA |
3756 | struct lwp_info *lwp; |
3757 | ||
4a6ed09b PA |
3758 | /* We add/delete threads from the list as clone/exit events are |
3759 | processed, so just try deleting exited threads still in the | |
3760 | thread list. */ | |
3761 | delete_exited_threads (); | |
a6904d5a PA |
3762 | |
3763 | /* Update the processor core that each lwp/thread was last seen | |
3764 | running on. */ | |
3765 | ALL_LWPS (lwp) | |
1ad3de98 PA |
3766 | { |
3767 | /* Avoid accessing /proc if the thread hasn't run since we last | |
3768 | time we fetched the thread's core. Accessing /proc becomes | |
3769 | noticeably expensive when we have thousands of LWPs. */ | |
3770 | if (lwp->core == -1) | |
3771 | lwp->core = linux_common_core_of_thread (lwp->ptid); | |
3772 | } | |
8a06aea7 PA |
3773 | } |
3774 | ||
a068643d | 3775 | std::string |
f6ac5f3d | 3776 | linux_nat_target::pid_to_str (ptid_t ptid) |
d6b0e80f | 3777 | { |
15a9e13e | 3778 | if (ptid.lwp_p () |
e38504b3 | 3779 | && (ptid.pid () != ptid.lwp () |
e99b03dc | 3780 | || num_lwps (ptid.pid ()) > 1)) |
a068643d | 3781 | return string_printf ("LWP %ld", ptid.lwp ()); |
d6b0e80f AC |
3782 | |
3783 | return normal_pid_to_str (ptid); | |
3784 | } | |
3785 | ||
f6ac5f3d PA |
3786 | const char * |
3787 | linux_nat_target::thread_name (struct thread_info *thr) | |
4694da01 | 3788 | { |
79efa585 | 3789 | return linux_proc_tid_get_name (thr->ptid); |
4694da01 TT |
3790 | } |
3791 | ||
dba24537 AC |
3792 | /* Accepts an integer PID; Returns a string representing a file that |
3793 | can be opened to get the symbols for the child process. */ | |
3794 | ||
f6ac5f3d PA |
3795 | char * |
3796 | linux_nat_target::pid_to_exec_file (int pid) | |
dba24537 | 3797 | { |
e0d86d2c | 3798 | return linux_proc_pid_to_exec_file (pid); |
dba24537 AC |
3799 | } |
3800 | ||
05c06f31 PA |
3801 | /* Keep the /proc/<pid>/mem file open between memory accesses, as a |
3802 | cache to avoid constantly closing/opening the file in the common | |
3803 | case of multiple memory reads/writes from/to the same inferior. | |
3804 | Note we don't keep a file open per inferior to avoid keeping too | |
3805 | many file descriptors open, which can run into resource limits. */ | |
3806 | static struct | |
3807 | { | |
3808 | /* The LWP this open file is for. Note that after opening the file, | |
3809 | even if the thread subsequently exits, the open file is still | |
3810 | usable for accessing memory. It's only when the whole process | |
3811 | exits or execs that the file becomes invalid (at which point | |
3812 | reads/writes return EOF). */ | |
3813 | ptid_t ptid; | |
10d6c8cd | 3814 | |
05c06f31 PA |
3815 | /* The file descriptor. -1 if file is not open. */ |
3816 | int fd = -1; | |
3817 | ||
3818 | /* Close FD and clear it to -1. */ | |
3819 | void close () | |
3820 | { | |
3821 | linux_nat_debug_printf ("closing fd %d for /proc/%d/task/%ld/mem\n", | |
3822 | fd, ptid.pid (), ptid.lwp ()); | |
3823 | ::close (fd); | |
3824 | fd = -1; | |
3825 | } | |
3826 | } last_proc_mem_file; | |
3827 | ||
3828 | /* Close the /proc/<pid>/mem file if its LWP matches PTID. */ | |
3829 | ||
3830 | static void | |
3831 | maybe_close_proc_mem_file (pid_t pid) | |
dba24537 | 3832 | { |
05c06f31 PA |
3833 | if (last_proc_mem_file.ptid.pid () == pid) |
3834 | last_proc_mem_file.close (); | |
3835 | } | |
dba24537 | 3836 | |
05c06f31 PA |
3837 | /* Helper for linux_proc_xfer_memory_partial. Accesses /proc via |
3838 | PTID. Returns -1 on error, with errno set. Returns number of | |
3839 | read/written bytes otherwise. Returns 0 on EOF, which indicates | |
3840 | the address space is gone (because the process exited or | |
3841 | execed). */ | |
dba24537 | 3842 | |
05c06f31 PA |
3843 | static ssize_t |
3844 | linux_proc_xfer_memory_partial_pid (ptid_t ptid, | |
3845 | gdb_byte *readbuf, const gdb_byte *writebuf, | |
3846 | ULONGEST offset, LONGEST len) | |
3847 | { | |
3848 | ssize_t ret; | |
dba24537 | 3849 | |
05c06f31 PA |
3850 | /* As long as we're hitting the same inferior, the previously open |
3851 | file is good, even if the thread it was open for exits. */ | |
3852 | if (last_proc_mem_file.fd != -1 | |
3853 | && last_proc_mem_file.ptid.pid () != ptid.pid ()) | |
3854 | last_proc_mem_file.close (); | |
3855 | ||
3856 | if (last_proc_mem_file.fd == -1) | |
3857 | { | |
3858 | /* Actually use /proc/<pid>/task/<lwp>/mem instead of | |
3859 | /proc/<lwp>/mem to avoid PID-reuse races, as we may be trying | |
3860 | to read memory via a thread which we've already reaped. | |
3861 | /proc/<lwp>/mem could open a file for the wrong process. If | |
3862 | the LWPID is reused for the same process it's OK, we can read | |
3863 | memory through it just fine. If the LWPID is reused for a | |
3864 | different process, then the open will fail because the path | |
3865 | won't exist. */ | |
3866 | char filename[64]; | |
3867 | xsnprintf (filename, sizeof filename, | |
3868 | "/proc/%d/task/%ld/mem", ptid.pid (), ptid.lwp ()); | |
3869 | ||
3870 | last_proc_mem_file.fd | |
3871 | = gdb_open_cloexec (filename, O_RDWR | O_LARGEFILE, 0); | |
3872 | ||
3873 | if (last_proc_mem_file.fd == -1) | |
3874 | { | |
3875 | linux_nat_debug_printf ("opening %s failed: %s (%d)\n", | |
3876 | filename, safe_strerror (errno), errno); | |
3877 | return -1; | |
3878 | } | |
3879 | last_proc_mem_file.ptid = ptid; | |
3880 | ||
3881 | linux_nat_debug_printf ("opened fd %d for %s\n", | |
3882 | last_proc_mem_file.fd, filename); | |
3883 | } | |
3884 | ||
3885 | int fd = last_proc_mem_file.fd; | |
dba24537 | 3886 | |
a379284a AA |
3887 | /* Use pread64/pwrite64 if available, since they save a syscall and can |
3888 | handle 64-bit offsets even on 32-bit platforms (for instance, SPARC | |
3889 | debugging a SPARC64 application). */ | |
dba24537 | 3890 | #ifdef HAVE_PREAD64 |
a379284a AA |
3891 | ret = (readbuf ? pread64 (fd, readbuf, len, offset) |
3892 | : pwrite64 (fd, writebuf, len, offset)); | |
dba24537 | 3893 | #else |
a379284a AA |
3894 | ret = lseek (fd, offset, SEEK_SET); |
3895 | if (ret != -1) | |
3896 | ret = (readbuf ? read (fd, readbuf, len) | |
3897 | : write (fd, writebuf, len)); | |
dba24537 | 3898 | #endif |
dba24537 | 3899 | |
05c06f31 PA |
3900 | if (ret == -1) |
3901 | { | |
3902 | linux_nat_debug_printf ("accessing fd %d for pid %ld failed: %s (%d)\n", | |
3903 | fd, ptid.lwp (), | |
3904 | safe_strerror (errno), errno); | |
3905 | } | |
3906 | else if (ret == 0) | |
3907 | { | |
3908 | linux_nat_debug_printf ("accessing fd %d for pid %ld got EOF\n", | |
3909 | fd, ptid.lwp ()); | |
3910 | } | |
9b409511 | 3911 | |
05c06f31 PA |
3912 | return ret; |
3913 | } | |
3914 | ||
3915 | /* Implement the to_xfer_partial target method using /proc/<pid>/mem. | |
3916 | Because we can use a single read/write call, this can be much more | |
3917 | efficient than banging away at PTRACE_PEEKTEXT. Also, unlike | |
3918 | PTRACE_PEEKTEXT/PTRACE_POKETEXT, this works with running | |
3919 | threads. */ | |
3920 | ||
3921 | static enum target_xfer_status | |
3922 | linux_proc_xfer_memory_partial (gdb_byte *readbuf, const gdb_byte *writebuf, | |
3923 | ULONGEST offset, LONGEST len, | |
3924 | ULONGEST *xfered_len) | |
3925 | { | |
3926 | /* Unlike PTRACE_PEEKTEXT/PTRACE_POKETEXT, reading/writing from/to | |
3927 | /proc/<pid>/mem works with running threads, and even exited | |
3928 | threads if the file was already open. If we need to open or | |
3929 | reopen the /proc file though, we may get an EACCES error | |
3930 | ("Permission denied"), meaning the thread is gone but its exit | |
3931 | status isn't reaped yet, or ENOENT if the thread is gone and | |
3932 | already reaped. In that case, just try opening the file for | |
3933 | another thread in the process. If all threads fail, then it must | |
3934 | mean the whole process exited, in which case there's nothing else | |
3935 | to do and we just fail the memory access. | |
3936 | ||
3937 | Note we don't simply always access via the leader thread because | |
3938 | the leader may exit without exiting the whole process. See | |
3939 | gdb.threads/leader-exit.exp, for example. */ | |
3940 | ||
3941 | /* It's frequently the case that the selected thread is stopped, and | |
3942 | is thus not likely to exit (unless something kills the process | |
3943 | outside our control, with e.g., SIGKILL). Give that one a try | |
3944 | first. | |
3945 | ||
3946 | Also, inferior_ptid may actually point at an LWP not in lwp_list. | |
3947 | This happens when we're detaching from a fork child that we don't | |
3948 | want to debug ("set detach-on-fork on"), and the breakpoints | |
3949 | module uninstalls breakpoints from the fork child. Which process | |
3950 | to access is given by inferior_ptid. */ | |
3951 | int res = linux_proc_xfer_memory_partial_pid (inferior_ptid, | |
3952 | readbuf, writebuf, | |
3953 | offset, len); | |
3954 | if (res == 0) | |
3955 | { | |
3956 | /* EOF means the address space is gone, the whole | |
3957 | process exited or execed. */ | |
3958 | return TARGET_XFER_EOF; | |
3959 | } | |
3960 | else if (res != -1) | |
3961 | { | |
3962 | *xfered_len = res; | |
3963 | return TARGET_XFER_OK; | |
3964 | } | |
9b409511 YQ |
3965 | else |
3966 | { | |
05c06f31 PA |
3967 | /* If we simply raced with the thread exiting (EACCES), or the |
3968 | current thread is THREAD_EXITED (ENOENT), try some other | |
3969 | thread. It's easier to handle an ENOENT failure than check | |
3970 | for THREAD_EXIT upfront because this function is called | |
3971 | before a thread for inferior_ptid is added to the thread | |
3972 | list. */ | |
3973 | if (errno != EACCES && errno != ENOENT) | |
3974 | return TARGET_XFER_EOF; | |
3975 | } | |
3976 | ||
3977 | int cur_pid = current_inferior ()->pid; | |
3978 | ||
3979 | if (inferior_ptid.pid () != cur_pid) | |
3980 | { | |
3981 | /* We're accessing a fork child, and the access above failed. | |
3982 | Don't bother iterating the LWP list, since there's no other | |
3983 | LWP for this process. */ | |
3984 | return TARGET_XFER_EOF; | |
3985 | } | |
3986 | ||
3987 | /* Iterate over LWPs of the current inferior, trying to access | |
3988 | memory through one of them. */ | |
3989 | for (lwp_info *lp = lwp_list; lp != nullptr; lp = lp->next) | |
3990 | { | |
3991 | if (lp->ptid.pid () != cur_pid) | |
3992 | continue; | |
3993 | ||
3994 | res = linux_proc_xfer_memory_partial_pid (lp->ptid, | |
3995 | readbuf, writebuf, | |
3996 | offset, len); | |
3997 | ||
3998 | if (res == 0) | |
3999 | { | |
4000 | /* EOF means the address space is gone, the whole process | |
4001 | exited or execed. */ | |
4002 | return TARGET_XFER_EOF; | |
4003 | } | |
4004 | else if (res == -1) | |
4005 | { | |
4006 | if (errno == EACCES) | |
4007 | { | |
4008 | /* This LWP is gone, try another one. */ | |
4009 | continue; | |
4010 | } | |
4011 | ||
4012 | return TARGET_XFER_EOF; | |
4013 | } | |
4014 | ||
4015 | *xfered_len = res; | |
9b409511 YQ |
4016 | return TARGET_XFER_OK; |
4017 | } | |
dba24537 | 4018 | |
05c06f31 PA |
4019 | /* No luck. */ |
4020 | return TARGET_XFER_EOF; | |
4021 | } | |
efcbbd14 | 4022 | |
dba24537 AC |
4023 | /* Parse LINE as a signal set and add its set bits to SIGS. */ |
4024 | ||
4025 | static void | |
4026 | add_line_to_sigset (const char *line, sigset_t *sigs) | |
4027 | { | |
4028 | int len = strlen (line) - 1; | |
4029 | const char *p; | |
4030 | int signum; | |
4031 | ||
4032 | if (line[len] != '\n') | |
8a3fe4f8 | 4033 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4034 | |
4035 | p = line; | |
4036 | signum = len * 4; | |
4037 | while (len-- > 0) | |
4038 | { | |
4039 | int digit; | |
4040 | ||
4041 | if (*p >= '0' && *p <= '9') | |
4042 | digit = *p - '0'; | |
4043 | else if (*p >= 'a' && *p <= 'f') | |
4044 | digit = *p - 'a' + 10; | |
4045 | else | |
8a3fe4f8 | 4046 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4047 | |
4048 | signum -= 4; | |
4049 | ||
4050 | if (digit & 1) | |
4051 | sigaddset (sigs, signum + 1); | |
4052 | if (digit & 2) | |
4053 | sigaddset (sigs, signum + 2); | |
4054 | if (digit & 4) | |
4055 | sigaddset (sigs, signum + 3); | |
4056 | if (digit & 8) | |
4057 | sigaddset (sigs, signum + 4); | |
4058 | ||
4059 | p++; | |
4060 | } | |
4061 | } | |
4062 | ||
4063 | /* Find process PID's pending signals from /proc/pid/status and set | |
4064 | SIGS to match. */ | |
4065 | ||
4066 | void | |
3e43a32a MS |
4067 | linux_proc_pending_signals (int pid, sigset_t *pending, |
4068 | sigset_t *blocked, sigset_t *ignored) | |
dba24537 | 4069 | { |
d8d2a3ee | 4070 | char buffer[PATH_MAX], fname[PATH_MAX]; |
dba24537 AC |
4071 | |
4072 | sigemptyset (pending); | |
4073 | sigemptyset (blocked); | |
4074 | sigemptyset (ignored); | |
cde33bf1 | 4075 | xsnprintf (fname, sizeof fname, "/proc/%d/status", pid); |
d419f42d | 4076 | gdb_file_up procfile = gdb_fopen_cloexec (fname, "r"); |
dba24537 | 4077 | if (procfile == NULL) |
8a3fe4f8 | 4078 | error (_("Could not open %s"), fname); |
dba24537 | 4079 | |
d419f42d | 4080 | while (fgets (buffer, PATH_MAX, procfile.get ()) != NULL) |
dba24537 AC |
4081 | { |
4082 | /* Normal queued signals are on the SigPnd line in the status | |
4083 | file. However, 2.6 kernels also have a "shared" pending | |
4084 | queue for delivering signals to a thread group, so check for | |
4085 | a ShdPnd line also. | |
4086 | ||
4087 | Unfortunately some Red Hat kernels include the shared pending | |
4088 | queue but not the ShdPnd status field. */ | |
4089 | ||
61012eef | 4090 | if (startswith (buffer, "SigPnd:\t")) |
dba24537 | 4091 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4092 | else if (startswith (buffer, "ShdPnd:\t")) |
dba24537 | 4093 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4094 | else if (startswith (buffer, "SigBlk:\t")) |
dba24537 | 4095 | add_line_to_sigset (buffer + 8, blocked); |
61012eef | 4096 | else if (startswith (buffer, "SigIgn:\t")) |
dba24537 AC |
4097 | add_line_to_sigset (buffer + 8, ignored); |
4098 | } | |
dba24537 AC |
4099 | } |
4100 | ||
9b409511 | 4101 | static enum target_xfer_status |
f6ac5f3d | 4102 | linux_nat_xfer_osdata (enum target_object object, |
e0881a8e | 4103 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
4104 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
4105 | ULONGEST *xfered_len) | |
07e059b5 | 4106 | { |
07e059b5 VP |
4107 | gdb_assert (object == TARGET_OBJECT_OSDATA); |
4108 | ||
9b409511 YQ |
4109 | *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len); |
4110 | if (*xfered_len == 0) | |
4111 | return TARGET_XFER_EOF; | |
4112 | else | |
4113 | return TARGET_XFER_OK; | |
07e059b5 VP |
4114 | } |
4115 | ||
f6ac5f3d PA |
4116 | std::vector<static_tracepoint_marker> |
4117 | linux_nat_target::static_tracepoint_markers_by_strid (const char *strid) | |
5808517f YQ |
4118 | { |
4119 | char s[IPA_CMD_BUF_SIZE]; | |
e99b03dc | 4120 | int pid = inferior_ptid.pid (); |
5d9310c4 | 4121 | std::vector<static_tracepoint_marker> markers; |
256642e8 | 4122 | const char *p = s; |
fd79271b | 4123 | ptid_t ptid = ptid_t (pid, 0, 0); |
5d9310c4 | 4124 | static_tracepoint_marker marker; |
5808517f YQ |
4125 | |
4126 | /* Pause all */ | |
4127 | target_stop (ptid); | |
4128 | ||
4129 | memcpy (s, "qTfSTM", sizeof ("qTfSTM")); | |
4130 | s[sizeof ("qTfSTM")] = 0; | |
4131 | ||
42476b70 | 4132 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f | 4133 | |
1db93f14 TT |
4134 | /* Unpause all. */ |
4135 | SCOPE_EXIT { target_continue_no_signal (ptid); }; | |
5808517f YQ |
4136 | |
4137 | while (*p++ == 'm') | |
4138 | { | |
5808517f YQ |
4139 | do |
4140 | { | |
5d9310c4 | 4141 | parse_static_tracepoint_marker_definition (p, &p, &marker); |
5808517f | 4142 | |
5d9310c4 SM |
4143 | if (strid == NULL || marker.str_id == strid) |
4144 | markers.push_back (std::move (marker)); | |
5808517f YQ |
4145 | } |
4146 | while (*p++ == ','); /* comma-separated list */ | |
4147 | ||
4148 | memcpy (s, "qTsSTM", sizeof ("qTsSTM")); | |
4149 | s[sizeof ("qTsSTM")] = 0; | |
42476b70 | 4150 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4151 | p = s; |
4152 | } | |
4153 | ||
5808517f YQ |
4154 | return markers; |
4155 | } | |
4156 | ||
b84876c2 PA |
4157 | /* target_is_async_p implementation. */ |
4158 | ||
57810aa7 | 4159 | bool |
f6ac5f3d | 4160 | linux_nat_target::is_async_p () |
b84876c2 | 4161 | { |
198297aa | 4162 | return linux_is_async_p (); |
b84876c2 PA |
4163 | } |
4164 | ||
4165 | /* target_can_async_p implementation. */ | |
4166 | ||
57810aa7 | 4167 | bool |
f6ac5f3d | 4168 | linux_nat_target::can_async_p () |
b84876c2 | 4169 | { |
fde1b17d SM |
4170 | /* We're always async, unless the user explicitly prevented it with the |
4171 | "maint set target-async" command. */ | |
3dd5b83d | 4172 | return target_async_permitted; |
b84876c2 PA |
4173 | } |
4174 | ||
57810aa7 | 4175 | bool |
f6ac5f3d | 4176 | linux_nat_target::supports_non_stop () |
9908b566 | 4177 | { |
f80c8ec4 | 4178 | return true; |
9908b566 VP |
4179 | } |
4180 | ||
fbea99ea PA |
4181 | /* to_always_non_stop_p implementation. */ |
4182 | ||
57810aa7 | 4183 | bool |
f6ac5f3d | 4184 | linux_nat_target::always_non_stop_p () |
fbea99ea | 4185 | { |
f80c8ec4 | 4186 | return true; |
fbea99ea PA |
4187 | } |
4188 | ||
57810aa7 | 4189 | bool |
f6ac5f3d | 4190 | linux_nat_target::supports_multi_process () |
d90e17a7 | 4191 | { |
aee91db3 | 4192 | return true; |
d90e17a7 PA |
4193 | } |
4194 | ||
57810aa7 | 4195 | bool |
f6ac5f3d | 4196 | linux_nat_target::supports_disable_randomization () |
03583c20 | 4197 | { |
f80c8ec4 | 4198 | return true; |
03583c20 UW |
4199 | } |
4200 | ||
7feb7d06 PA |
4201 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
4202 | so we notice when any child changes state, and notify the | |
4203 | event-loop; it allows us to use sigsuspend in linux_nat_wait_1 | |
4204 | above to wait for the arrival of a SIGCHLD. */ | |
4205 | ||
b84876c2 | 4206 | static void |
7feb7d06 | 4207 | sigchld_handler (int signo) |
b84876c2 | 4208 | { |
7feb7d06 PA |
4209 | int old_errno = errno; |
4210 | ||
01124a23 | 4211 | if (debug_linux_nat) |
da5bd37e | 4212 | gdb_stdlog->write_async_safe ("sigchld\n", sizeof ("sigchld\n") - 1); |
7feb7d06 PA |
4213 | |
4214 | if (signo == SIGCHLD | |
4215 | && linux_nat_event_pipe[0] != -1) | |
4216 | async_file_mark (); /* Let the event loop know that there are | |
4217 | events to handle. */ | |
4218 | ||
4219 | errno = old_errno; | |
4220 | } | |
4221 | ||
4222 | /* Callback registered with the target events file descriptor. */ | |
4223 | ||
4224 | static void | |
4225 | handle_target_event (int error, gdb_client_data client_data) | |
4226 | { | |
b1a35af2 | 4227 | inferior_event_handler (INF_REG_EVENT); |
7feb7d06 PA |
4228 | } |
4229 | ||
4230 | /* Create/destroy the target events pipe. Returns previous state. */ | |
4231 | ||
4232 | static int | |
4233 | linux_async_pipe (int enable) | |
4234 | { | |
198297aa | 4235 | int previous = linux_is_async_p (); |
7feb7d06 PA |
4236 | |
4237 | if (previous != enable) | |
4238 | { | |
4239 | sigset_t prev_mask; | |
4240 | ||
12696c10 PA |
4241 | /* Block child signals while we create/destroy the pipe, as |
4242 | their handler writes to it. */ | |
7feb7d06 PA |
4243 | block_child_signals (&prev_mask); |
4244 | ||
4245 | if (enable) | |
4246 | { | |
614c279d | 4247 | if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1) |
7feb7d06 PA |
4248 | internal_error (__FILE__, __LINE__, |
4249 | "creating event pipe failed."); | |
4250 | ||
4251 | fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK); | |
4252 | fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK); | |
4253 | } | |
4254 | else | |
4255 | { | |
4256 | close (linux_nat_event_pipe[0]); | |
4257 | close (linux_nat_event_pipe[1]); | |
4258 | linux_nat_event_pipe[0] = -1; | |
4259 | linux_nat_event_pipe[1] = -1; | |
4260 | } | |
4261 | ||
4262 | restore_child_signals_mask (&prev_mask); | |
4263 | } | |
4264 | ||
4265 | return previous; | |
b84876c2 PA |
4266 | } |
4267 | ||
5b6d1e4f PA |
4268 | int |
4269 | linux_nat_target::async_wait_fd () | |
4270 | { | |
4271 | return linux_nat_event_pipe[0]; | |
4272 | } | |
4273 | ||
b84876c2 PA |
4274 | /* target_async implementation. */ |
4275 | ||
f6ac5f3d PA |
4276 | void |
4277 | linux_nat_target::async (int enable) | |
b84876c2 | 4278 | { |
6a3753b3 | 4279 | if (enable) |
b84876c2 | 4280 | { |
7feb7d06 PA |
4281 | if (!linux_async_pipe (1)) |
4282 | { | |
4283 | add_file_handler (linux_nat_event_pipe[0], | |
2554f6f5 SM |
4284 | handle_target_event, NULL, |
4285 | "linux-nat"); | |
7feb7d06 PA |
4286 | /* There may be pending events to handle. Tell the event loop |
4287 | to poll them. */ | |
4288 | async_file_mark (); | |
4289 | } | |
b84876c2 PA |
4290 | } |
4291 | else | |
4292 | { | |
b84876c2 | 4293 | delete_file_handler (linux_nat_event_pipe[0]); |
7feb7d06 | 4294 | linux_async_pipe (0); |
b84876c2 PA |
4295 | } |
4296 | return; | |
4297 | } | |
4298 | ||
a493e3e2 | 4299 | /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other |
252fbfc8 PA |
4300 | event came out. */ |
4301 | ||
4c28f408 | 4302 | static int |
d3a70e03 | 4303 | linux_nat_stop_lwp (struct lwp_info *lwp) |
4c28f408 | 4304 | { |
d90e17a7 | 4305 | if (!lwp->stopped) |
252fbfc8 | 4306 | { |
9327494e SM |
4307 | linux_nat_debug_printf ("running -> suspending %s", |
4308 | target_pid_to_str (lwp->ptid).c_str ()); | |
252fbfc8 | 4309 | |
252fbfc8 | 4310 | |
25289eb2 PA |
4311 | if (lwp->last_resume_kind == resume_stop) |
4312 | { | |
9327494e SM |
4313 | linux_nat_debug_printf ("already stopping LWP %ld at GDB's request", |
4314 | lwp->ptid.lwp ()); | |
25289eb2 PA |
4315 | return 0; |
4316 | } | |
252fbfc8 | 4317 | |
d3a70e03 | 4318 | stop_callback (lwp); |
25289eb2 | 4319 | lwp->last_resume_kind = resume_stop; |
d90e17a7 PA |
4320 | } |
4321 | else | |
4322 | { | |
4323 | /* Already known to be stopped; do nothing. */ | |
252fbfc8 | 4324 | |
d90e17a7 PA |
4325 | if (debug_linux_nat) |
4326 | { | |
5b6d1e4f | 4327 | if (find_thread_ptid (linux_target, lwp->ptid)->stop_requested) |
9327494e SM |
4328 | linux_nat_debug_printf ("already stopped/stop_requested %s", |
4329 | target_pid_to_str (lwp->ptid).c_str ()); | |
d90e17a7 | 4330 | else |
9327494e SM |
4331 | linux_nat_debug_printf ("already stopped/no stop_requested yet %s", |
4332 | target_pid_to_str (lwp->ptid).c_str ()); | |
252fbfc8 PA |
4333 | } |
4334 | } | |
4c28f408 PA |
4335 | return 0; |
4336 | } | |
4337 | ||
f6ac5f3d PA |
4338 | void |
4339 | linux_nat_target::stop (ptid_t ptid) | |
4c28f408 | 4340 | { |
d3a70e03 | 4341 | iterate_over_lwps (ptid, linux_nat_stop_lwp); |
bfedc46a PA |
4342 | } |
4343 | ||
f6ac5f3d PA |
4344 | void |
4345 | linux_nat_target::close () | |
d90e17a7 PA |
4346 | { |
4347 | /* Unregister from the event loop. */ | |
f6ac5f3d PA |
4348 | if (is_async_p ()) |
4349 | async (0); | |
d90e17a7 | 4350 | |
f6ac5f3d | 4351 | inf_ptrace_target::close (); |
d90e17a7 PA |
4352 | } |
4353 | ||
c0694254 PA |
4354 | /* When requests are passed down from the linux-nat layer to the |
4355 | single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are | |
4356 | used. The address space pointer is stored in the inferior object, | |
4357 | but the common code that is passed such ptid can't tell whether | |
4358 | lwpid is a "main" process id or not (it assumes so). We reverse | |
4359 | look up the "main" process id from the lwp here. */ | |
4360 | ||
f6ac5f3d PA |
4361 | struct address_space * |
4362 | linux_nat_target::thread_address_space (ptid_t ptid) | |
c0694254 PA |
4363 | { |
4364 | struct lwp_info *lwp; | |
4365 | struct inferior *inf; | |
4366 | int pid; | |
4367 | ||
e38504b3 | 4368 | if (ptid.lwp () == 0) |
c0694254 PA |
4369 | { |
4370 | /* An (lwpid,0,0) ptid. Look up the lwp object to get at the | |
4371 | tgid. */ | |
4372 | lwp = find_lwp_pid (ptid); | |
e99b03dc | 4373 | pid = lwp->ptid.pid (); |
c0694254 PA |
4374 | } |
4375 | else | |
4376 | { | |
4377 | /* A (pid,lwpid,0) ptid. */ | |
e99b03dc | 4378 | pid = ptid.pid (); |
c0694254 PA |
4379 | } |
4380 | ||
5b6d1e4f | 4381 | inf = find_inferior_pid (this, pid); |
c0694254 PA |
4382 | gdb_assert (inf != NULL); |
4383 | return inf->aspace; | |
4384 | } | |
4385 | ||
dc146f7c VP |
4386 | /* Return the cached value of the processor core for thread PTID. */ |
4387 | ||
f6ac5f3d PA |
4388 | int |
4389 | linux_nat_target::core_of_thread (ptid_t ptid) | |
dc146f7c VP |
4390 | { |
4391 | struct lwp_info *info = find_lwp_pid (ptid); | |
e0881a8e | 4392 | |
dc146f7c VP |
4393 | if (info) |
4394 | return info->core; | |
4395 | return -1; | |
4396 | } | |
4397 | ||
7a6a1731 GB |
4398 | /* Implementation of to_filesystem_is_local. */ |
4399 | ||
57810aa7 | 4400 | bool |
f6ac5f3d | 4401 | linux_nat_target::filesystem_is_local () |
7a6a1731 GB |
4402 | { |
4403 | struct inferior *inf = current_inferior (); | |
4404 | ||
4405 | if (inf->fake_pid_p || inf->pid == 0) | |
57810aa7 | 4406 | return true; |
7a6a1731 GB |
4407 | |
4408 | return linux_ns_same (inf->pid, LINUX_NS_MNT); | |
4409 | } | |
4410 | ||
4411 | /* Convert the INF argument passed to a to_fileio_* method | |
4412 | to a process ID suitable for passing to its corresponding | |
4413 | linux_mntns_* function. If INF is non-NULL then the | |
4414 | caller is requesting the filesystem seen by INF. If INF | |
4415 | is NULL then the caller is requesting the filesystem seen | |
4416 | by the GDB. We fall back to GDB's filesystem in the case | |
4417 | that INF is non-NULL but its PID is unknown. */ | |
4418 | ||
4419 | static pid_t | |
4420 | linux_nat_fileio_pid_of (struct inferior *inf) | |
4421 | { | |
4422 | if (inf == NULL || inf->fake_pid_p || inf->pid == 0) | |
4423 | return getpid (); | |
4424 | else | |
4425 | return inf->pid; | |
4426 | } | |
4427 | ||
4428 | /* Implementation of to_fileio_open. */ | |
4429 | ||
f6ac5f3d PA |
4430 | int |
4431 | linux_nat_target::fileio_open (struct inferior *inf, const char *filename, | |
4432 | int flags, int mode, int warn_if_slow, | |
4433 | int *target_errno) | |
7a6a1731 GB |
4434 | { |
4435 | int nat_flags; | |
4436 | mode_t nat_mode; | |
4437 | int fd; | |
4438 | ||
4439 | if (fileio_to_host_openflags (flags, &nat_flags) == -1 | |
4440 | || fileio_to_host_mode (mode, &nat_mode) == -1) | |
4441 | { | |
4442 | *target_errno = FILEIO_EINVAL; | |
4443 | return -1; | |
4444 | } | |
4445 | ||
4446 | fd = linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf), | |
4447 | filename, nat_flags, nat_mode); | |
4448 | if (fd == -1) | |
4449 | *target_errno = host_to_fileio_error (errno); | |
4450 | ||
4451 | return fd; | |
4452 | } | |
4453 | ||
4454 | /* Implementation of to_fileio_readlink. */ | |
4455 | ||
f6ac5f3d PA |
4456 | gdb::optional<std::string> |
4457 | linux_nat_target::fileio_readlink (struct inferior *inf, const char *filename, | |
4458 | int *target_errno) | |
7a6a1731 GB |
4459 | { |
4460 | char buf[PATH_MAX]; | |
4461 | int len; | |
7a6a1731 GB |
4462 | |
4463 | len = linux_mntns_readlink (linux_nat_fileio_pid_of (inf), | |
4464 | filename, buf, sizeof (buf)); | |
4465 | if (len < 0) | |
4466 | { | |
4467 | *target_errno = host_to_fileio_error (errno); | |
e0d3522b | 4468 | return {}; |
7a6a1731 GB |
4469 | } |
4470 | ||
e0d3522b | 4471 | return std::string (buf, len); |
7a6a1731 GB |
4472 | } |
4473 | ||
4474 | /* Implementation of to_fileio_unlink. */ | |
4475 | ||
f6ac5f3d PA |
4476 | int |
4477 | linux_nat_target::fileio_unlink (struct inferior *inf, const char *filename, | |
4478 | int *target_errno) | |
7a6a1731 GB |
4479 | { |
4480 | int ret; | |
4481 | ||
4482 | ret = linux_mntns_unlink (linux_nat_fileio_pid_of (inf), | |
4483 | filename); | |
4484 | if (ret == -1) | |
4485 | *target_errno = host_to_fileio_error (errno); | |
4486 | ||
4487 | return ret; | |
4488 | } | |
4489 | ||
aa01bd36 PA |
4490 | /* Implementation of the to_thread_events method. */ |
4491 | ||
f6ac5f3d PA |
4492 | void |
4493 | linux_nat_target::thread_events (int enable) | |
aa01bd36 PA |
4494 | { |
4495 | report_thread_events = enable; | |
4496 | } | |
4497 | ||
f6ac5f3d PA |
4498 | linux_nat_target::linux_nat_target () |
4499 | { | |
f973ed9c DJ |
4500 | /* We don't change the stratum; this target will sit at |
4501 | process_stratum and thread_db will set at thread_stratum. This | |
4502 | is a little strange, since this is a multi-threaded-capable | |
4503 | target, but we want to be on the stack below thread_db, and we | |
4504 | also want to be used for single-threaded processes. */ | |
f973ed9c DJ |
4505 | } |
4506 | ||
f865ee35 JK |
4507 | /* See linux-nat.h. */ |
4508 | ||
4509 | int | |
4510 | linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo) | |
9f0bdab8 | 4511 | { |
da559b09 | 4512 | int pid; |
9f0bdab8 | 4513 | |
e38504b3 | 4514 | pid = ptid.lwp (); |
da559b09 | 4515 | if (pid == 0) |
e99b03dc | 4516 | pid = ptid.pid (); |
f865ee35 | 4517 | |
da559b09 JK |
4518 | errno = 0; |
4519 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo); | |
4520 | if (errno != 0) | |
4521 | { | |
4522 | memset (siginfo, 0, sizeof (*siginfo)); | |
4523 | return 0; | |
4524 | } | |
f865ee35 | 4525 | return 1; |
9f0bdab8 DJ |
4526 | } |
4527 | ||
7b669087 GB |
4528 | /* See nat/linux-nat.h. */ |
4529 | ||
4530 | ptid_t | |
4531 | current_lwp_ptid (void) | |
4532 | { | |
15a9e13e | 4533 | gdb_assert (inferior_ptid.lwp_p ()); |
7b669087 GB |
4534 | return inferior_ptid; |
4535 | } | |
4536 | ||
6c265988 | 4537 | void _initialize_linux_nat (); |
d6b0e80f | 4538 | void |
6c265988 | 4539 | _initialize_linux_nat () |
d6b0e80f | 4540 | { |
ccce17b0 YQ |
4541 | add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance, |
4542 | &debug_linux_nat, _("\ | |
b84876c2 PA |
4543 | Set debugging of GNU/Linux lwp module."), _("\ |
4544 | Show debugging of GNU/Linux lwp module."), _("\ | |
4545 | Enables printf debugging output."), | |
ccce17b0 YQ |
4546 | NULL, |
4547 | show_debug_linux_nat, | |
4548 | &setdebuglist, &showdebuglist); | |
b84876c2 | 4549 | |
7a6a1731 GB |
4550 | add_setshow_boolean_cmd ("linux-namespaces", class_maintenance, |
4551 | &debug_linux_namespaces, _("\ | |
4552 | Set debugging of GNU/Linux namespaces module."), _("\ | |
4553 | Show debugging of GNU/Linux namespaces module."), _("\ | |
4554 | Enables printf debugging output."), | |
4555 | NULL, | |
4556 | NULL, | |
4557 | &setdebuglist, &showdebuglist); | |
4558 | ||
7feb7d06 PA |
4559 | /* Install a SIGCHLD handler. */ |
4560 | sigchld_action.sa_handler = sigchld_handler; | |
4561 | sigemptyset (&sigchld_action.sa_mask); | |
4562 | sigchld_action.sa_flags = SA_RESTART; | |
b84876c2 PA |
4563 | |
4564 | /* Make it the default. */ | |
7feb7d06 | 4565 | sigaction (SIGCHLD, &sigchld_action, NULL); |
d6b0e80f AC |
4566 | |
4567 | /* Make sure we don't block SIGCHLD during a sigsuspend. */ | |
21987b9c | 4568 | gdb_sigmask (SIG_SETMASK, NULL, &suspend_mask); |
d6b0e80f AC |
4569 | sigdelset (&suspend_mask, SIGCHLD); |
4570 | ||
7feb7d06 | 4571 | sigemptyset (&blocked_mask); |
774113b0 PA |
4572 | |
4573 | lwp_lwpid_htab_create (); | |
d6b0e80f AC |
4574 | } |
4575 | \f | |
4576 | ||
4577 | /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to | |
4578 | the GNU/Linux Threads library and therefore doesn't really belong | |
4579 | here. */ | |
4580 | ||
089436f7 TV |
4581 | /* NPTL reserves the first two RT signals, but does not provide any |
4582 | way for the debugger to query the signal numbers - fortunately | |
4583 | they don't change. */ | |
4584 | static int lin_thread_signals[] = { __SIGRTMIN, __SIGRTMIN + 1 }; | |
d6b0e80f | 4585 | |
089436f7 TV |
4586 | /* See linux-nat.h. */ |
4587 | ||
4588 | unsigned int | |
4589 | lin_thread_get_thread_signal_num (void) | |
d6b0e80f | 4590 | { |
089436f7 TV |
4591 | return sizeof (lin_thread_signals) / sizeof (lin_thread_signals[0]); |
4592 | } | |
d6b0e80f | 4593 | |
089436f7 TV |
4594 | /* See linux-nat.h. */ |
4595 | ||
4596 | int | |
4597 | lin_thread_get_thread_signal (unsigned int i) | |
4598 | { | |
4599 | gdb_assert (i < lin_thread_get_thread_signal_num ()); | |
4600 | return lin_thread_signals[i]; | |
d6b0e80f | 4601 | } |