Commit | Line | Data |
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3993f6b1 | 1 | /* GNU/Linux native-dependent code common to multiple platforms. |
dba24537 | 2 | |
b811d2c2 | 3 | Copyright (C) 2001-2020 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 PA |
49 | #include "inf-loop.h" |
50 | #include "event-loop.h" | |
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" |
efcbbd14 | 71 | |
1777feb0 | 72 | /* This comment documents high-level logic of this file. |
8a77dff3 VP |
73 | |
74 | Waiting for events in sync mode | |
75 | =============================== | |
76 | ||
4a6ed09b PA |
77 | When waiting for an event in a specific thread, we just use waitpid, |
78 | passing the specific pid, and not passing WNOHANG. | |
79 | ||
80 | When waiting for an event in all threads, waitpid is not quite good: | |
81 | ||
82 | - If the thread group leader exits while other threads in the thread | |
83 | group still exist, waitpid(TGID, ...) hangs. That waitpid won't | |
84 | return an exit status until the other threads in the group are | |
85 | reaped. | |
86 | ||
87 | - When a non-leader thread execs, that thread just vanishes without | |
88 | reporting an exit (so we'd hang if we waited for it explicitly in | |
89 | that case). The exec event is instead reported to the TGID pid. | |
90 | ||
91 | The solution is to always use -1 and WNOHANG, together with | |
92 | sigsuspend. | |
93 | ||
94 | First, we use non-blocking waitpid to check for events. If nothing is | |
95 | found, we use sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, | |
96 | it means something happened to a child process. As soon as we know | |
97 | there's an event, we get back to calling nonblocking waitpid. | |
98 | ||
99 | Note that SIGCHLD should be blocked between waitpid and sigsuspend | |
100 | calls, so that we don't miss a signal. If SIGCHLD arrives in between, | |
101 | when it's blocked, the signal becomes pending and sigsuspend | |
102 | immediately notices it and returns. | |
103 | ||
104 | Waiting for events in async mode (TARGET_WNOHANG) | |
105 | ================================================= | |
8a77dff3 | 106 | |
7feb7d06 PA |
107 | In async mode, GDB should always be ready to handle both user input |
108 | and target events, so neither blocking waitpid nor sigsuspend are | |
109 | viable options. Instead, we should asynchronously notify the GDB main | |
110 | event loop whenever there's an unprocessed event from the target. We | |
111 | detect asynchronous target events by handling SIGCHLD signals. To | |
112 | notify the event loop about target events, the self-pipe trick is used | |
113 | --- a pipe is registered as waitable event source in the event loop, | |
114 | the event loop select/poll's on the read end of this pipe (as well on | |
115 | other event sources, e.g., stdin), and the SIGCHLD handler writes a | |
116 | byte to this pipe. This is more portable than relying on | |
117 | pselect/ppoll, since on kernels that lack those syscalls, libc | |
118 | emulates them with select/poll+sigprocmask, and that is racy | |
119 | (a.k.a. plain broken). | |
120 | ||
121 | Obviously, if we fail to notify the event loop if there's a target | |
122 | event, it's bad. OTOH, if we notify the event loop when there's no | |
123 | event from the target, linux_nat_wait will detect that there's no real | |
124 | event to report, and return event of type TARGET_WAITKIND_IGNORE. | |
125 | This is mostly harmless, but it will waste time and is better avoided. | |
126 | ||
127 | The main design point is that every time GDB is outside linux-nat.c, | |
128 | we have a SIGCHLD handler installed that is called when something | |
129 | happens to the target and notifies the GDB event loop. Whenever GDB | |
130 | core decides to handle the event, and calls into linux-nat.c, we | |
131 | process things as in sync mode, except that the we never block in | |
132 | sigsuspend. | |
133 | ||
134 | While processing an event, we may end up momentarily blocked in | |
135 | waitpid calls. Those waitpid calls, while blocking, are guarantied to | |
136 | return quickly. E.g., in all-stop mode, before reporting to the core | |
137 | that an LWP hit a breakpoint, all LWPs are stopped by sending them | |
138 | SIGSTOP, and synchronously waiting for the SIGSTOP to be reported. | |
139 | Note that this is different from blocking indefinitely waiting for the | |
140 | next event --- here, we're already handling an event. | |
8a77dff3 VP |
141 | |
142 | Use of signals | |
143 | ============== | |
144 | ||
145 | We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another | |
146 | signal is not entirely significant; we just need for a signal to be delivered, | |
147 | so that we can intercept it. SIGSTOP's advantage is that it can not be | |
148 | blocked. A disadvantage is that it is not a real-time signal, so it can only | |
149 | be queued once; we do not keep track of other sources of SIGSTOP. | |
150 | ||
151 | Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't | |
152 | use them, because they have special behavior when the signal is generated - | |
153 | not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL | |
154 | kills the entire thread group. | |
155 | ||
156 | A delivered SIGSTOP would stop the entire thread group, not just the thread we | |
157 | tkill'd. But we never let the SIGSTOP be delivered; we always intercept and | |
158 | cancel it (by PTRACE_CONT without passing SIGSTOP). | |
159 | ||
160 | We could use a real-time signal instead. This would solve those problems; we | |
161 | could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB. | |
162 | But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH | |
163 | generates it, and there are races with trying to find a signal that is not | |
4a6ed09b PA |
164 | blocked. |
165 | ||
166 | Exec events | |
167 | =========== | |
168 | ||
169 | The case of a thread group (process) with 3 or more threads, and a | |
170 | thread other than the leader execs is worth detailing: | |
171 | ||
172 | On an exec, the Linux kernel destroys all threads except the execing | |
173 | one in the thread group, and resets the execing thread's tid to the | |
174 | tgid. No exit notification is sent for the execing thread -- from the | |
175 | ptracer's perspective, it appears as though the execing thread just | |
176 | vanishes. Until we reap all other threads except the leader and the | |
177 | execing thread, the leader will be zombie, and the execing thread will | |
178 | be in `D (disc sleep)' state. As soon as all other threads are | |
179 | reaped, the execing thread changes its tid to the tgid, and the | |
180 | previous (zombie) leader vanishes, giving place to the "new" | |
181 | leader. */ | |
a0ef4274 | 182 | |
dba24537 AC |
183 | #ifndef O_LARGEFILE |
184 | #define O_LARGEFILE 0 | |
185 | #endif | |
0274a8ce | 186 | |
f6ac5f3d PA |
187 | struct linux_nat_target *linux_target; |
188 | ||
433bbbf8 | 189 | /* Does the current host support PTRACE_GETREGSET? */ |
0bdb2f78 | 190 | enum tribool have_ptrace_getregset = TRIBOOL_UNKNOWN; |
433bbbf8 | 191 | |
ccce17b0 | 192 | static unsigned int debug_linux_nat; |
920d2a44 AC |
193 | static void |
194 | show_debug_linux_nat (struct ui_file *file, int from_tty, | |
195 | struct cmd_list_element *c, const char *value) | |
196 | { | |
197 | fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"), | |
198 | value); | |
199 | } | |
d6b0e80f | 200 | |
ae087d01 DJ |
201 | struct simple_pid_list |
202 | { | |
203 | int pid; | |
3d799a95 | 204 | int status; |
ae087d01 DJ |
205 | struct simple_pid_list *next; |
206 | }; | |
207 | struct simple_pid_list *stopped_pids; | |
208 | ||
aa01bd36 PA |
209 | /* Whether target_thread_events is in effect. */ |
210 | static int report_thread_events; | |
211 | ||
3dd5b83d PA |
212 | /* Async mode support. */ |
213 | ||
b84876c2 PA |
214 | /* The read/write ends of the pipe registered as waitable file in the |
215 | event loop. */ | |
216 | static int linux_nat_event_pipe[2] = { -1, -1 }; | |
217 | ||
198297aa PA |
218 | /* True if we're currently in async mode. */ |
219 | #define linux_is_async_p() (linux_nat_event_pipe[0] != -1) | |
220 | ||
7feb7d06 | 221 | /* Flush the event pipe. */ |
b84876c2 | 222 | |
7feb7d06 PA |
223 | static void |
224 | async_file_flush (void) | |
b84876c2 | 225 | { |
7feb7d06 PA |
226 | int ret; |
227 | char buf; | |
b84876c2 | 228 | |
7feb7d06 | 229 | do |
b84876c2 | 230 | { |
7feb7d06 | 231 | ret = read (linux_nat_event_pipe[0], &buf, 1); |
b84876c2 | 232 | } |
7feb7d06 | 233 | while (ret >= 0 || (ret == -1 && errno == EINTR)); |
b84876c2 PA |
234 | } |
235 | ||
7feb7d06 PA |
236 | /* Put something (anything, doesn't matter what, or how much) in event |
237 | pipe, so that the select/poll in the event-loop realizes we have | |
238 | something to process. */ | |
252fbfc8 | 239 | |
b84876c2 | 240 | static void |
7feb7d06 | 241 | async_file_mark (void) |
b84876c2 | 242 | { |
7feb7d06 | 243 | int ret; |
b84876c2 | 244 | |
7feb7d06 PA |
245 | /* It doesn't really matter what the pipe contains, as long we end |
246 | up with something in it. Might as well flush the previous | |
247 | left-overs. */ | |
248 | async_file_flush (); | |
b84876c2 | 249 | |
7feb7d06 | 250 | do |
b84876c2 | 251 | { |
7feb7d06 | 252 | ret = write (linux_nat_event_pipe[1], "+", 1); |
b84876c2 | 253 | } |
7feb7d06 | 254 | while (ret == -1 && errno == EINTR); |
b84876c2 | 255 | |
7feb7d06 PA |
256 | /* Ignore EAGAIN. If the pipe is full, the event loop will already |
257 | be awakened anyway. */ | |
b84876c2 PA |
258 | } |
259 | ||
7feb7d06 PA |
260 | static int kill_lwp (int lwpid, int signo); |
261 | ||
d3a70e03 | 262 | static int stop_callback (struct lwp_info *lp); |
7feb7d06 PA |
263 | |
264 | static void block_child_signals (sigset_t *prev_mask); | |
265 | static void restore_child_signals_mask (sigset_t *prev_mask); | |
2277426b PA |
266 | |
267 | struct lwp_info; | |
268 | static struct lwp_info *add_lwp (ptid_t ptid); | |
269 | static void purge_lwp_list (int pid); | |
4403d8e9 | 270 | static void delete_lwp (ptid_t ptid); |
2277426b PA |
271 | static struct lwp_info *find_lwp_pid (ptid_t ptid); |
272 | ||
8a99810d PA |
273 | static int lwp_status_pending_p (struct lwp_info *lp); |
274 | ||
e7ad2f14 PA |
275 | static void save_stop_reason (struct lwp_info *lp); |
276 | ||
cff068da GB |
277 | \f |
278 | /* LWP accessors. */ | |
279 | ||
280 | /* See nat/linux-nat.h. */ | |
281 | ||
282 | ptid_t | |
283 | ptid_of_lwp (struct lwp_info *lwp) | |
284 | { | |
285 | return lwp->ptid; | |
286 | } | |
287 | ||
288 | /* See nat/linux-nat.h. */ | |
289 | ||
4b134ca1 GB |
290 | void |
291 | lwp_set_arch_private_info (struct lwp_info *lwp, | |
292 | struct arch_lwp_info *info) | |
293 | { | |
294 | lwp->arch_private = info; | |
295 | } | |
296 | ||
297 | /* See nat/linux-nat.h. */ | |
298 | ||
299 | struct arch_lwp_info * | |
300 | lwp_arch_private_info (struct lwp_info *lwp) | |
301 | { | |
302 | return lwp->arch_private; | |
303 | } | |
304 | ||
305 | /* See nat/linux-nat.h. */ | |
306 | ||
cff068da GB |
307 | int |
308 | lwp_is_stopped (struct lwp_info *lwp) | |
309 | { | |
310 | return lwp->stopped; | |
311 | } | |
312 | ||
313 | /* See nat/linux-nat.h. */ | |
314 | ||
315 | enum target_stop_reason | |
316 | lwp_stop_reason (struct lwp_info *lwp) | |
317 | { | |
318 | return lwp->stop_reason; | |
319 | } | |
320 | ||
0e00e962 AA |
321 | /* See nat/linux-nat.h. */ |
322 | ||
323 | int | |
324 | lwp_is_stepping (struct lwp_info *lwp) | |
325 | { | |
326 | return lwp->step; | |
327 | } | |
328 | ||
ae087d01 DJ |
329 | \f |
330 | /* Trivial list manipulation functions to keep track of a list of | |
331 | new stopped processes. */ | |
332 | static void | |
3d799a95 | 333 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
ae087d01 | 334 | { |
8d749320 | 335 | struct simple_pid_list *new_pid = XNEW (struct simple_pid_list); |
e0881a8e | 336 | |
ae087d01 | 337 | new_pid->pid = pid; |
3d799a95 | 338 | new_pid->status = status; |
ae087d01 DJ |
339 | new_pid->next = *listp; |
340 | *listp = new_pid; | |
341 | } | |
342 | ||
343 | static int | |
46a96992 | 344 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
ae087d01 DJ |
345 | { |
346 | struct simple_pid_list **p; | |
347 | ||
348 | for (p = listp; *p != NULL; p = &(*p)->next) | |
349 | if ((*p)->pid == pid) | |
350 | { | |
351 | struct simple_pid_list *next = (*p)->next; | |
e0881a8e | 352 | |
46a96992 | 353 | *statusp = (*p)->status; |
ae087d01 DJ |
354 | xfree (*p); |
355 | *p = next; | |
356 | return 1; | |
357 | } | |
358 | return 0; | |
359 | } | |
360 | ||
de0d863e DB |
361 | /* Return the ptrace options that we want to try to enable. */ |
362 | ||
363 | static int | |
364 | linux_nat_ptrace_options (int attached) | |
365 | { | |
366 | int options = 0; | |
367 | ||
368 | if (!attached) | |
369 | options |= PTRACE_O_EXITKILL; | |
370 | ||
371 | options |= (PTRACE_O_TRACESYSGOOD | |
372 | | PTRACE_O_TRACEVFORKDONE | |
373 | | PTRACE_O_TRACEVFORK | |
374 | | PTRACE_O_TRACEFORK | |
375 | | PTRACE_O_TRACEEXEC); | |
376 | ||
377 | return options; | |
378 | } | |
379 | ||
1b919490 VB |
380 | /* Initialize ptrace and procfs warnings and check for supported |
381 | ptrace features given PID. | |
beed38b8 JB |
382 | |
383 | ATTACHED should be nonzero iff we attached to the inferior. */ | |
3993f6b1 DJ |
384 | |
385 | static void | |
1b919490 | 386 | linux_init_ptrace_procfs (pid_t pid, int attached) |
3993f6b1 | 387 | { |
de0d863e DB |
388 | int options = linux_nat_ptrace_options (attached); |
389 | ||
390 | linux_enable_event_reporting (pid, options); | |
96d7229d | 391 | linux_ptrace_init_warnings (); |
1b919490 | 392 | linux_proc_init_warnings (); |
4de4c07c DJ |
393 | } |
394 | ||
f6ac5f3d PA |
395 | linux_nat_target::~linux_nat_target () |
396 | {} | |
397 | ||
398 | void | |
399 | linux_nat_target::post_attach (int pid) | |
4de4c07c | 400 | { |
1b919490 | 401 | linux_init_ptrace_procfs (pid, 1); |
4de4c07c DJ |
402 | } |
403 | ||
f6ac5f3d PA |
404 | void |
405 | linux_nat_target::post_startup_inferior (ptid_t ptid) | |
4de4c07c | 406 | { |
1b919490 | 407 | linux_init_ptrace_procfs (ptid.pid (), 0); |
4de4c07c DJ |
408 | } |
409 | ||
4403d8e9 JK |
410 | /* Return the number of known LWPs in the tgid given by PID. */ |
411 | ||
412 | static int | |
413 | num_lwps (int pid) | |
414 | { | |
415 | int count = 0; | |
416 | struct lwp_info *lp; | |
417 | ||
418 | for (lp = lwp_list; lp; lp = lp->next) | |
e99b03dc | 419 | if (lp->ptid.pid () == pid) |
4403d8e9 JK |
420 | count++; |
421 | ||
422 | return count; | |
423 | } | |
424 | ||
169bb27b | 425 | /* Deleter for lwp_info unique_ptr specialisation. */ |
4403d8e9 | 426 | |
169bb27b | 427 | struct lwp_deleter |
4403d8e9 | 428 | { |
169bb27b AB |
429 | void operator() (struct lwp_info *lwp) const |
430 | { | |
431 | delete_lwp (lwp->ptid); | |
432 | } | |
433 | }; | |
4403d8e9 | 434 | |
169bb27b AB |
435 | /* A unique_ptr specialisation for lwp_info. */ |
436 | ||
437 | typedef std::unique_ptr<struct lwp_info, lwp_deleter> lwp_info_up; | |
4403d8e9 | 438 | |
d83ad864 DB |
439 | /* Target hook for follow_fork. On entry inferior_ptid must be the |
440 | ptid of the followed inferior. At return, inferior_ptid will be | |
441 | unchanged. */ | |
442 | ||
f6ac5f3d PA |
443 | int |
444 | linux_nat_target::follow_fork (int follow_child, int detach_fork) | |
3993f6b1 | 445 | { |
d83ad864 | 446 | if (!follow_child) |
4de4c07c | 447 | { |
6c95b8df | 448 | struct lwp_info *child_lp = NULL; |
d83ad864 | 449 | int has_vforked; |
79639e11 | 450 | ptid_t parent_ptid, child_ptid; |
d83ad864 DB |
451 | int parent_pid, child_pid; |
452 | ||
453 | has_vforked = (inferior_thread ()->pending_follow.kind | |
454 | == TARGET_WAITKIND_VFORKED); | |
79639e11 PA |
455 | parent_ptid = inferior_ptid; |
456 | child_ptid = inferior_thread ()->pending_follow.value.related_pid; | |
e38504b3 TT |
457 | parent_pid = parent_ptid.lwp (); |
458 | child_pid = child_ptid.lwp (); | |
4de4c07c | 459 | |
1777feb0 | 460 | /* We're already attached to the parent, by default. */ |
2989a365 | 461 | child_lp = add_lwp (child_ptid); |
d83ad864 DB |
462 | child_lp->stopped = 1; |
463 | child_lp->last_resume_kind = resume_stop; | |
4de4c07c | 464 | |
ac264b3b MS |
465 | /* Detach new forked process? */ |
466 | if (detach_fork) | |
f75c00e4 | 467 | { |
95347337 AB |
468 | int child_stop_signal = 0; |
469 | bool detach_child = true; | |
4403d8e9 | 470 | |
169bb27b AB |
471 | /* Move CHILD_LP into a unique_ptr and clear the source pointer |
472 | to prevent us doing anything stupid with it. */ | |
473 | lwp_info_up child_lp_ptr (child_lp); | |
474 | child_lp = nullptr; | |
475 | ||
476 | linux_target->low_prepare_to_resume (child_lp_ptr.get ()); | |
c077881a HZ |
477 | |
478 | /* When debugging an inferior in an architecture that supports | |
479 | hardware single stepping on a kernel without commit | |
480 | 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child | |
481 | process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits | |
482 | set if the parent process had them set. | |
483 | To work around this, single step the child process | |
484 | once before detaching to clear the flags. */ | |
485 | ||
2fd9d7ca PA |
486 | /* Note that we consult the parent's architecture instead of |
487 | the child's because there's no inferior for the child at | |
488 | this point. */ | |
c077881a | 489 | if (!gdbarch_software_single_step_p (target_thread_architecture |
2fd9d7ca | 490 | (parent_ptid))) |
c077881a | 491 | { |
95347337 AB |
492 | int status; |
493 | ||
c077881a HZ |
494 | linux_disable_event_reporting (child_pid); |
495 | if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0) | |
496 | perror_with_name (_("Couldn't do single step")); | |
497 | if (my_waitpid (child_pid, &status, 0) < 0) | |
498 | perror_with_name (_("Couldn't wait vfork process")); | |
95347337 AB |
499 | else |
500 | { | |
501 | detach_child = WIFSTOPPED (status); | |
502 | child_stop_signal = WSTOPSIG (status); | |
503 | } | |
c077881a HZ |
504 | } |
505 | ||
95347337 | 506 | if (detach_child) |
9caaaa83 | 507 | { |
95347337 | 508 | int signo = child_stop_signal; |
9caaaa83 | 509 | |
9caaaa83 PA |
510 | if (signo != 0 |
511 | && !signal_pass_state (gdb_signal_from_host (signo))) | |
512 | signo = 0; | |
513 | ptrace (PTRACE_DETACH, child_pid, 0, signo); | |
514 | } | |
ac264b3b MS |
515 | } |
516 | else | |
517 | { | |
5b6d1e4f PA |
518 | /* Switching inferior_ptid is not enough, because then |
519 | inferior_thread () would crash by not finding the thread | |
520 | in the current inferior. */ | |
521 | scoped_restore_current_thread restore_current_thread; | |
522 | thread_info *child = find_thread_ptid (this, child_ptid); | |
523 | switch_to_thread (child); | |
2989a365 | 524 | |
6c95b8df | 525 | /* Let the thread_db layer learn about this new process. */ |
2277426b | 526 | check_for_thread_db (); |
ac264b3b | 527 | } |
9016a515 DJ |
528 | |
529 | if (has_vforked) | |
530 | { | |
3ced3da4 | 531 | struct lwp_info *parent_lp; |
6c95b8df | 532 | |
79639e11 | 533 | parent_lp = find_lwp_pid (parent_ptid); |
96d7229d | 534 | gdb_assert (linux_supports_tracefork () >= 0); |
3ced3da4 | 535 | |
96d7229d | 536 | if (linux_supports_tracevforkdone ()) |
9016a515 | 537 | { |
6c95b8df PA |
538 | if (debug_linux_nat) |
539 | fprintf_unfiltered (gdb_stdlog, | |
540 | "LCFF: waiting for VFORK_DONE on %d\n", | |
541 | parent_pid); | |
3ced3da4 | 542 | parent_lp->stopped = 1; |
9016a515 | 543 | |
6c95b8df PA |
544 | /* We'll handle the VFORK_DONE event like any other |
545 | event, in target_wait. */ | |
9016a515 DJ |
546 | } |
547 | else | |
548 | { | |
549 | /* We can't insert breakpoints until the child has | |
550 | finished with the shared memory region. We need to | |
551 | wait until that happens. Ideal would be to just | |
552 | call: | |
553 | - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0); | |
554 | - waitpid (parent_pid, &status, __WALL); | |
555 | However, most architectures can't handle a syscall | |
556 | being traced on the way out if it wasn't traced on | |
557 | the way in. | |
558 | ||
559 | We might also think to loop, continuing the child | |
560 | until it exits or gets a SIGTRAP. One problem is | |
561 | that the child might call ptrace with PTRACE_TRACEME. | |
562 | ||
563 | There's no simple and reliable way to figure out when | |
564 | the vforked child will be done with its copy of the | |
565 | shared memory. We could step it out of the syscall, | |
566 | two instructions, let it go, and then single-step the | |
567 | parent once. When we have hardware single-step, this | |
568 | would work; with software single-step it could still | |
569 | be made to work but we'd have to be able to insert | |
570 | single-step breakpoints in the child, and we'd have | |
571 | to insert -just- the single-step breakpoint in the | |
572 | parent. Very awkward. | |
573 | ||
574 | In the end, the best we can do is to make sure it | |
575 | runs for a little while. Hopefully it will be out of | |
576 | range of any breakpoints we reinsert. Usually this | |
577 | is only the single-step breakpoint at vfork's return | |
578 | point. */ | |
579 | ||
6c95b8df PA |
580 | if (debug_linux_nat) |
581 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
582 | "LCFF: no VFORK_DONE " |
583 | "support, sleeping a bit\n"); | |
6c95b8df | 584 | |
9016a515 | 585 | usleep (10000); |
9016a515 | 586 | |
6c95b8df PA |
587 | /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event, |
588 | and leave it pending. The next linux_nat_resume call | |
589 | will notice a pending event, and bypasses actually | |
590 | resuming the inferior. */ | |
3ced3da4 PA |
591 | parent_lp->status = 0; |
592 | parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE; | |
593 | parent_lp->stopped = 1; | |
6c95b8df PA |
594 | |
595 | /* If we're in async mode, need to tell the event loop | |
596 | there's something here to process. */ | |
d9d41e78 | 597 | if (target_is_async_p ()) |
6c95b8df PA |
598 | async_file_mark (); |
599 | } | |
9016a515 | 600 | } |
4de4c07c | 601 | } |
3993f6b1 | 602 | else |
4de4c07c | 603 | { |
3ced3da4 | 604 | struct lwp_info *child_lp; |
4de4c07c | 605 | |
3ced3da4 PA |
606 | child_lp = add_lwp (inferior_ptid); |
607 | child_lp->stopped = 1; | |
25289eb2 | 608 | child_lp->last_resume_kind = resume_stop; |
6c95b8df | 609 | |
6c95b8df | 610 | /* Let the thread_db layer learn about this new process. */ |
ef29ce1a | 611 | check_for_thread_db (); |
4de4c07c DJ |
612 | } |
613 | ||
614 | return 0; | |
615 | } | |
616 | ||
4de4c07c | 617 | \f |
f6ac5f3d PA |
618 | int |
619 | linux_nat_target::insert_fork_catchpoint (int pid) | |
4de4c07c | 620 | { |
96d7229d | 621 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
622 | } |
623 | ||
f6ac5f3d PA |
624 | int |
625 | linux_nat_target::remove_fork_catchpoint (int pid) | |
eb73ad13 PA |
626 | { |
627 | return 0; | |
628 | } | |
629 | ||
f6ac5f3d PA |
630 | int |
631 | linux_nat_target::insert_vfork_catchpoint (int pid) | |
3993f6b1 | 632 | { |
96d7229d | 633 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
634 | } |
635 | ||
f6ac5f3d PA |
636 | int |
637 | linux_nat_target::remove_vfork_catchpoint (int pid) | |
eb73ad13 PA |
638 | { |
639 | return 0; | |
640 | } | |
641 | ||
f6ac5f3d PA |
642 | int |
643 | linux_nat_target::insert_exec_catchpoint (int pid) | |
3993f6b1 | 644 | { |
96d7229d | 645 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
646 | } |
647 | ||
f6ac5f3d PA |
648 | int |
649 | linux_nat_target::remove_exec_catchpoint (int pid) | |
eb73ad13 PA |
650 | { |
651 | return 0; | |
652 | } | |
653 | ||
f6ac5f3d PA |
654 | int |
655 | linux_nat_target::set_syscall_catchpoint (int pid, bool needed, int any_count, | |
656 | gdb::array_view<const int> syscall_counts) | |
a96d9b2e | 657 | { |
96d7229d | 658 | if (!linux_supports_tracesysgood ()) |
77b06cd7 TJB |
659 | return 1; |
660 | ||
a96d9b2e SDJ |
661 | /* On GNU/Linux, we ignore the arguments. It means that we only |
662 | enable the syscall catchpoints, but do not disable them. | |
77b06cd7 | 663 | |
649a140c | 664 | Also, we do not use the `syscall_counts' information because we do not |
a96d9b2e SDJ |
665 | filter system calls here. We let GDB do the logic for us. */ |
666 | return 0; | |
667 | } | |
668 | ||
774113b0 PA |
669 | /* List of known LWPs, keyed by LWP PID. This speeds up the common |
670 | case of mapping a PID returned from the kernel to our corresponding | |
671 | lwp_info data structure. */ | |
672 | static htab_t lwp_lwpid_htab; | |
673 | ||
674 | /* Calculate a hash from a lwp_info's LWP PID. */ | |
675 | ||
676 | static hashval_t | |
677 | lwp_info_hash (const void *ap) | |
678 | { | |
679 | const struct lwp_info *lp = (struct lwp_info *) ap; | |
e38504b3 | 680 | pid_t pid = lp->ptid.lwp (); |
774113b0 PA |
681 | |
682 | return iterative_hash_object (pid, 0); | |
683 | } | |
684 | ||
685 | /* Equality function for the lwp_info hash table. Compares the LWP's | |
686 | PID. */ | |
687 | ||
688 | static int | |
689 | lwp_lwpid_htab_eq (const void *a, const void *b) | |
690 | { | |
691 | const struct lwp_info *entry = (const struct lwp_info *) a; | |
692 | const struct lwp_info *element = (const struct lwp_info *) b; | |
693 | ||
e38504b3 | 694 | return entry->ptid.lwp () == element->ptid.lwp (); |
774113b0 PA |
695 | } |
696 | ||
697 | /* Create the lwp_lwpid_htab hash table. */ | |
698 | ||
699 | static void | |
700 | lwp_lwpid_htab_create (void) | |
701 | { | |
702 | lwp_lwpid_htab = htab_create (100, lwp_info_hash, lwp_lwpid_htab_eq, NULL); | |
703 | } | |
704 | ||
705 | /* Add LP to the hash table. */ | |
706 | ||
707 | static void | |
708 | lwp_lwpid_htab_add_lwp (struct lwp_info *lp) | |
709 | { | |
710 | void **slot; | |
711 | ||
712 | slot = htab_find_slot (lwp_lwpid_htab, lp, INSERT); | |
713 | gdb_assert (slot != NULL && *slot == NULL); | |
714 | *slot = lp; | |
715 | } | |
716 | ||
717 | /* Head of doubly-linked list of known LWPs. Sorted by reverse | |
718 | creation order. This order is assumed in some cases. E.g., | |
719 | reaping status after killing alls lwps of a process: the leader LWP | |
720 | must be reaped last. */ | |
9f0bdab8 | 721 | struct lwp_info *lwp_list; |
774113b0 PA |
722 | |
723 | /* Add LP to sorted-by-reverse-creation-order doubly-linked list. */ | |
724 | ||
725 | static void | |
726 | lwp_list_add (struct lwp_info *lp) | |
727 | { | |
728 | lp->next = lwp_list; | |
729 | if (lwp_list != NULL) | |
730 | lwp_list->prev = lp; | |
731 | lwp_list = lp; | |
732 | } | |
733 | ||
734 | /* Remove LP from sorted-by-reverse-creation-order doubly-linked | |
735 | list. */ | |
736 | ||
737 | static void | |
738 | lwp_list_remove (struct lwp_info *lp) | |
739 | { | |
740 | /* Remove from sorted-by-creation-order list. */ | |
741 | if (lp->next != NULL) | |
742 | lp->next->prev = lp->prev; | |
743 | if (lp->prev != NULL) | |
744 | lp->prev->next = lp->next; | |
745 | if (lp == lwp_list) | |
746 | lwp_list = lp->next; | |
747 | } | |
748 | ||
d6b0e80f AC |
749 | \f |
750 | ||
d6b0e80f AC |
751 | /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in |
752 | _initialize_linux_nat. */ | |
753 | static sigset_t suspend_mask; | |
754 | ||
7feb7d06 PA |
755 | /* Signals to block to make that sigsuspend work. */ |
756 | static sigset_t blocked_mask; | |
757 | ||
758 | /* SIGCHLD action. */ | |
759 | struct sigaction sigchld_action; | |
b84876c2 | 760 | |
7feb7d06 PA |
761 | /* Block child signals (SIGCHLD and linux threads signals), and store |
762 | the previous mask in PREV_MASK. */ | |
84e46146 | 763 | |
7feb7d06 PA |
764 | static void |
765 | block_child_signals (sigset_t *prev_mask) | |
766 | { | |
767 | /* Make sure SIGCHLD is blocked. */ | |
768 | if (!sigismember (&blocked_mask, SIGCHLD)) | |
769 | sigaddset (&blocked_mask, SIGCHLD); | |
770 | ||
21987b9c | 771 | gdb_sigmask (SIG_BLOCK, &blocked_mask, prev_mask); |
7feb7d06 PA |
772 | } |
773 | ||
774 | /* Restore child signals mask, previously returned by | |
775 | block_child_signals. */ | |
776 | ||
777 | static void | |
778 | restore_child_signals_mask (sigset_t *prev_mask) | |
779 | { | |
21987b9c | 780 | gdb_sigmask (SIG_SETMASK, prev_mask, NULL); |
7feb7d06 | 781 | } |
2455069d UW |
782 | |
783 | /* Mask of signals to pass directly to the inferior. */ | |
784 | static sigset_t pass_mask; | |
785 | ||
786 | /* Update signals to pass to the inferior. */ | |
f6ac5f3d | 787 | void |
adc6a863 PA |
788 | linux_nat_target::pass_signals |
789 | (gdb::array_view<const unsigned char> pass_signals) | |
2455069d UW |
790 | { |
791 | int signo; | |
792 | ||
793 | sigemptyset (&pass_mask); | |
794 | ||
795 | for (signo = 1; signo < NSIG; signo++) | |
796 | { | |
2ea28649 | 797 | int target_signo = gdb_signal_from_host (signo); |
adc6a863 | 798 | if (target_signo < pass_signals.size () && pass_signals[target_signo]) |
2455069d UW |
799 | sigaddset (&pass_mask, signo); |
800 | } | |
801 | } | |
802 | ||
d6b0e80f AC |
803 | \f |
804 | ||
805 | /* Prototypes for local functions. */ | |
d3a70e03 TT |
806 | static int stop_wait_callback (struct lwp_info *lp); |
807 | static int resume_stopped_resumed_lwps (struct lwp_info *lp, const ptid_t wait_ptid); | |
ced2dffb | 808 | static int check_ptrace_stopped_lwp_gone (struct lwp_info *lp); |
710151dd | 809 | |
d6b0e80f | 810 | \f |
d6b0e80f | 811 | |
7b50312a PA |
812 | /* Destroy and free LP. */ |
813 | ||
814 | static void | |
815 | lwp_free (struct lwp_info *lp) | |
816 | { | |
466eecee | 817 | /* Let the arch specific bits release arch_lwp_info. */ |
135340af | 818 | linux_target->low_delete_thread (lp->arch_private); |
466eecee | 819 | |
7b50312a PA |
820 | xfree (lp); |
821 | } | |
822 | ||
774113b0 | 823 | /* Traversal function for purge_lwp_list. */ |
d90e17a7 | 824 | |
774113b0 PA |
825 | static int |
826 | lwp_lwpid_htab_remove_pid (void **slot, void *info) | |
d90e17a7 | 827 | { |
774113b0 PA |
828 | struct lwp_info *lp = (struct lwp_info *) *slot; |
829 | int pid = *(int *) info; | |
d90e17a7 | 830 | |
e99b03dc | 831 | if (lp->ptid.pid () == pid) |
d90e17a7 | 832 | { |
774113b0 PA |
833 | htab_clear_slot (lwp_lwpid_htab, slot); |
834 | lwp_list_remove (lp); | |
835 | lwp_free (lp); | |
836 | } | |
d90e17a7 | 837 | |
774113b0 PA |
838 | return 1; |
839 | } | |
d90e17a7 | 840 | |
774113b0 PA |
841 | /* Remove all LWPs belong to PID from the lwp list. */ |
842 | ||
843 | static void | |
844 | purge_lwp_list (int pid) | |
845 | { | |
846 | htab_traverse_noresize (lwp_lwpid_htab, lwp_lwpid_htab_remove_pid, &pid); | |
d90e17a7 PA |
847 | } |
848 | ||
26cb8b7c PA |
849 | /* Add the LWP specified by PTID to the list. PTID is the first LWP |
850 | in the process. Return a pointer to the structure describing the | |
851 | new LWP. | |
852 | ||
853 | This differs from add_lwp in that we don't let the arch specific | |
854 | bits know about this new thread. Current clients of this callback | |
855 | take the opportunity to install watchpoints in the new thread, and | |
856 | we shouldn't do that for the first thread. If we're spawning a | |
857 | child ("run"), the thread executes the shell wrapper first, and we | |
858 | shouldn't touch it until it execs the program we want to debug. | |
859 | For "attach", it'd be okay to call the callback, but it's not | |
860 | necessary, because watchpoints can't yet have been inserted into | |
861 | the inferior. */ | |
d6b0e80f AC |
862 | |
863 | static struct lwp_info * | |
26cb8b7c | 864 | add_initial_lwp (ptid_t ptid) |
d6b0e80f AC |
865 | { |
866 | struct lwp_info *lp; | |
867 | ||
15a9e13e | 868 | gdb_assert (ptid.lwp_p ()); |
d6b0e80f | 869 | |
8d749320 | 870 | lp = XNEW (struct lwp_info); |
d6b0e80f AC |
871 | |
872 | memset (lp, 0, sizeof (struct lwp_info)); | |
873 | ||
25289eb2 | 874 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
875 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
876 | ||
877 | lp->ptid = ptid; | |
dc146f7c | 878 | lp->core = -1; |
d6b0e80f | 879 | |
774113b0 PA |
880 | /* Add to sorted-by-reverse-creation-order list. */ |
881 | lwp_list_add (lp); | |
882 | ||
883 | /* Add to keyed-by-pid htab. */ | |
884 | lwp_lwpid_htab_add_lwp (lp); | |
d6b0e80f | 885 | |
26cb8b7c PA |
886 | return lp; |
887 | } | |
888 | ||
889 | /* Add the LWP specified by PID to the list. Return a pointer to the | |
890 | structure describing the new LWP. The LWP should already be | |
891 | stopped. */ | |
892 | ||
893 | static struct lwp_info * | |
894 | add_lwp (ptid_t ptid) | |
895 | { | |
896 | struct lwp_info *lp; | |
897 | ||
898 | lp = add_initial_lwp (ptid); | |
899 | ||
6e012a6c PA |
900 | /* Let the arch specific bits know about this new thread. Current |
901 | clients of this callback take the opportunity to install | |
26cb8b7c PA |
902 | watchpoints in the new thread. We don't do this for the first |
903 | thread though. See add_initial_lwp. */ | |
135340af | 904 | linux_target->low_new_thread (lp); |
9f0bdab8 | 905 | |
d6b0e80f AC |
906 | return lp; |
907 | } | |
908 | ||
909 | /* Remove the LWP specified by PID from the list. */ | |
910 | ||
911 | static void | |
912 | delete_lwp (ptid_t ptid) | |
913 | { | |
774113b0 PA |
914 | struct lwp_info *lp; |
915 | void **slot; | |
916 | struct lwp_info dummy; | |
d6b0e80f | 917 | |
774113b0 PA |
918 | dummy.ptid = ptid; |
919 | slot = htab_find_slot (lwp_lwpid_htab, &dummy, NO_INSERT); | |
920 | if (slot == NULL) | |
921 | return; | |
d6b0e80f | 922 | |
774113b0 PA |
923 | lp = *(struct lwp_info **) slot; |
924 | gdb_assert (lp != NULL); | |
d6b0e80f | 925 | |
774113b0 | 926 | htab_clear_slot (lwp_lwpid_htab, slot); |
d6b0e80f | 927 | |
774113b0 PA |
928 | /* Remove from sorted-by-creation-order list. */ |
929 | lwp_list_remove (lp); | |
d6b0e80f | 930 | |
774113b0 | 931 | /* Release. */ |
7b50312a | 932 | lwp_free (lp); |
d6b0e80f AC |
933 | } |
934 | ||
935 | /* Return a pointer to the structure describing the LWP corresponding | |
936 | to PID. If no corresponding LWP could be found, return NULL. */ | |
937 | ||
938 | static struct lwp_info * | |
939 | find_lwp_pid (ptid_t ptid) | |
940 | { | |
941 | struct lwp_info *lp; | |
942 | int lwp; | |
774113b0 | 943 | struct lwp_info dummy; |
d6b0e80f | 944 | |
15a9e13e | 945 | if (ptid.lwp_p ()) |
e38504b3 | 946 | lwp = ptid.lwp (); |
d6b0e80f | 947 | else |
e99b03dc | 948 | lwp = ptid.pid (); |
d6b0e80f | 949 | |
fd79271b | 950 | dummy.ptid = ptid_t (0, lwp, 0); |
774113b0 PA |
951 | lp = (struct lwp_info *) htab_find (lwp_lwpid_htab, &dummy); |
952 | return lp; | |
d6b0e80f AC |
953 | } |
954 | ||
6d4ee8c6 | 955 | /* See nat/linux-nat.h. */ |
d6b0e80f AC |
956 | |
957 | struct lwp_info * | |
d90e17a7 | 958 | iterate_over_lwps (ptid_t filter, |
d3a70e03 | 959 | gdb::function_view<iterate_over_lwps_ftype> callback) |
d6b0e80f AC |
960 | { |
961 | struct lwp_info *lp, *lpnext; | |
962 | ||
963 | for (lp = lwp_list; lp; lp = lpnext) | |
964 | { | |
965 | lpnext = lp->next; | |
d90e17a7 | 966 | |
26a57c92 | 967 | if (lp->ptid.matches (filter)) |
d90e17a7 | 968 | { |
d3a70e03 | 969 | if (callback (lp) != 0) |
d90e17a7 PA |
970 | return lp; |
971 | } | |
d6b0e80f AC |
972 | } |
973 | ||
974 | return NULL; | |
975 | } | |
976 | ||
2277426b PA |
977 | /* Update our internal state when changing from one checkpoint to |
978 | another indicated by NEW_PTID. We can only switch single-threaded | |
979 | applications, so we only create one new LWP, and the previous list | |
980 | is discarded. */ | |
f973ed9c DJ |
981 | |
982 | void | |
983 | linux_nat_switch_fork (ptid_t new_ptid) | |
984 | { | |
985 | struct lwp_info *lp; | |
986 | ||
e99b03dc | 987 | purge_lwp_list (inferior_ptid.pid ()); |
2277426b | 988 | |
f973ed9c DJ |
989 | lp = add_lwp (new_ptid); |
990 | lp->stopped = 1; | |
e26af52f | 991 | |
2277426b PA |
992 | /* This changes the thread's ptid while preserving the gdb thread |
993 | num. Also changes the inferior pid, while preserving the | |
994 | inferior num. */ | |
5b6d1e4f | 995 | thread_change_ptid (linux_target, inferior_ptid, new_ptid); |
2277426b PA |
996 | |
997 | /* We've just told GDB core that the thread changed target id, but, | |
998 | in fact, it really is a different thread, with different register | |
999 | contents. */ | |
1000 | registers_changed (); | |
e26af52f DJ |
1001 | } |
1002 | ||
e26af52f DJ |
1003 | /* Handle the exit of a single thread LP. */ |
1004 | ||
1005 | static void | |
1006 | exit_lwp (struct lwp_info *lp) | |
1007 | { | |
5b6d1e4f | 1008 | struct thread_info *th = find_thread_ptid (linux_target, lp->ptid); |
063bfe2e VP |
1009 | |
1010 | if (th) | |
e26af52f | 1011 | { |
17faa917 | 1012 | if (print_thread_events) |
a068643d TT |
1013 | printf_unfiltered (_("[%s exited]\n"), |
1014 | target_pid_to_str (lp->ptid).c_str ()); | |
17faa917 | 1015 | |
00431a78 | 1016 | delete_thread (th); |
e26af52f DJ |
1017 | } |
1018 | ||
1019 | delete_lwp (lp->ptid); | |
1020 | } | |
1021 | ||
a0ef4274 DJ |
1022 | /* Wait for the LWP specified by LP, which we have just attached to. |
1023 | Returns a wait status for that LWP, to cache. */ | |
1024 | ||
1025 | static int | |
22827c51 | 1026 | linux_nat_post_attach_wait (ptid_t ptid, int *signalled) |
a0ef4274 | 1027 | { |
e38504b3 | 1028 | pid_t new_pid, pid = ptid.lwp (); |
a0ef4274 DJ |
1029 | int status; |
1030 | ||
644cebc9 | 1031 | if (linux_proc_pid_is_stopped (pid)) |
a0ef4274 DJ |
1032 | { |
1033 | if (debug_linux_nat) | |
1034 | fprintf_unfiltered (gdb_stdlog, | |
1035 | "LNPAW: Attaching to a stopped process\n"); | |
1036 | ||
1037 | /* The process is definitely stopped. It is in a job control | |
1038 | stop, unless the kernel predates the TASK_STOPPED / | |
1039 | TASK_TRACED distinction, in which case it might be in a | |
1040 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
1041 | can kill it, signal it, et cetera. | |
1042 | ||
1043 | First make sure there is a pending SIGSTOP. Since we are | |
1044 | already attached, the process can not transition from stopped | |
1045 | to running without a PTRACE_CONT; so we know this signal will | |
1046 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
1047 | probably already in the queue (unless this kernel is old | |
1048 | enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP | |
1049 | is not an RT signal, it can only be queued once. */ | |
1050 | kill_lwp (pid, SIGSTOP); | |
1051 | ||
1052 | /* Finally, resume the stopped process. This will deliver the SIGSTOP | |
1053 | (or a higher priority signal, just like normal PTRACE_ATTACH). */ | |
1054 | ptrace (PTRACE_CONT, pid, 0, 0); | |
1055 | } | |
1056 | ||
1057 | /* Make sure the initial process is stopped. The user-level threads | |
1058 | layer might want to poke around in the inferior, and that won't | |
1059 | work if things haven't stabilized yet. */ | |
4a6ed09b | 1060 | new_pid = my_waitpid (pid, &status, __WALL); |
dacc9cb2 PP |
1061 | gdb_assert (pid == new_pid); |
1062 | ||
1063 | if (!WIFSTOPPED (status)) | |
1064 | { | |
1065 | /* The pid we tried to attach has apparently just exited. */ | |
1066 | if (debug_linux_nat) | |
1067 | fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s", | |
1068 | pid, status_to_str (status)); | |
1069 | return status; | |
1070 | } | |
a0ef4274 DJ |
1071 | |
1072 | if (WSTOPSIG (status) != SIGSTOP) | |
1073 | { | |
1074 | *signalled = 1; | |
1075 | if (debug_linux_nat) | |
1076 | fprintf_unfiltered (gdb_stdlog, | |
1077 | "LNPAW: Received %s after attaching\n", | |
1078 | status_to_str (status)); | |
1079 | } | |
1080 | ||
1081 | return status; | |
1082 | } | |
1083 | ||
f6ac5f3d PA |
1084 | void |
1085 | linux_nat_target::create_inferior (const char *exec_file, | |
1086 | const std::string &allargs, | |
1087 | char **env, int from_tty) | |
b84876c2 | 1088 | { |
41272101 TT |
1089 | maybe_disable_address_space_randomization restore_personality |
1090 | (disable_randomization); | |
b84876c2 PA |
1091 | |
1092 | /* The fork_child mechanism is synchronous and calls target_wait, so | |
1093 | we have to mask the async mode. */ | |
1094 | ||
2455069d | 1095 | /* Make sure we report all signals during startup. */ |
adc6a863 | 1096 | pass_signals ({}); |
2455069d | 1097 | |
f6ac5f3d | 1098 | inf_ptrace_target::create_inferior (exec_file, allargs, env, from_tty); |
b84876c2 PA |
1099 | } |
1100 | ||
8784d563 PA |
1101 | /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not |
1102 | already attached. Returns true if a new LWP is found, false | |
1103 | otherwise. */ | |
1104 | ||
1105 | static int | |
1106 | attach_proc_task_lwp_callback (ptid_t ptid) | |
1107 | { | |
1108 | struct lwp_info *lp; | |
1109 | ||
1110 | /* Ignore LWPs we're already attached to. */ | |
1111 | lp = find_lwp_pid (ptid); | |
1112 | if (lp == NULL) | |
1113 | { | |
e38504b3 | 1114 | int lwpid = ptid.lwp (); |
8784d563 PA |
1115 | |
1116 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) | |
1117 | { | |
1118 | int err = errno; | |
1119 | ||
1120 | /* Be quiet if we simply raced with the thread exiting. | |
1121 | EPERM is returned if the thread's task still exists, and | |
1122 | is marked as exited or zombie, as well as other | |
1123 | conditions, so in that case, confirm the status in | |
1124 | /proc/PID/status. */ | |
1125 | if (err == ESRCH | |
1126 | || (err == EPERM && linux_proc_pid_is_gone (lwpid))) | |
1127 | { | |
1128 | if (debug_linux_nat) | |
1129 | { | |
1130 | fprintf_unfiltered (gdb_stdlog, | |
1131 | "Cannot attach to lwp %d: " | |
1132 | "thread is gone (%d: %s)\n", | |
1133 | lwpid, err, safe_strerror (err)); | |
1134 | } | |
1135 | } | |
1136 | else | |
1137 | { | |
4d9b86e1 | 1138 | std::string reason |
50fa3001 | 1139 | = linux_ptrace_attach_fail_reason_string (ptid, err); |
4d9b86e1 | 1140 | |
f71f0b0d | 1141 | warning (_("Cannot attach to lwp %d: %s"), |
4d9b86e1 | 1142 | lwpid, reason.c_str ()); |
8784d563 PA |
1143 | } |
1144 | } | |
1145 | else | |
1146 | { | |
1147 | if (debug_linux_nat) | |
1148 | fprintf_unfiltered (gdb_stdlog, | |
1149 | "PTRACE_ATTACH %s, 0, 0 (OK)\n", | |
a068643d | 1150 | target_pid_to_str (ptid).c_str ()); |
8784d563 PA |
1151 | |
1152 | lp = add_lwp (ptid); | |
8784d563 PA |
1153 | |
1154 | /* The next time we wait for this LWP we'll see a SIGSTOP as | |
1155 | PTRACE_ATTACH brings it to a halt. */ | |
1156 | lp->signalled = 1; | |
1157 | ||
1158 | /* We need to wait for a stop before being able to make the | |
1159 | next ptrace call on this LWP. */ | |
1160 | lp->must_set_ptrace_flags = 1; | |
026a9174 PA |
1161 | |
1162 | /* So that wait collects the SIGSTOP. */ | |
1163 | lp->resumed = 1; | |
1164 | ||
1165 | /* Also add the LWP to gdb's thread list, in case a | |
1166 | matching libthread_db is not found (or the process uses | |
1167 | raw clone). */ | |
5b6d1e4f PA |
1168 | add_thread (linux_target, lp->ptid); |
1169 | set_running (linux_target, lp->ptid, 1); | |
1170 | set_executing (linux_target, lp->ptid, 1); | |
8784d563 PA |
1171 | } |
1172 | ||
1173 | return 1; | |
1174 | } | |
1175 | return 0; | |
1176 | } | |
1177 | ||
f6ac5f3d PA |
1178 | void |
1179 | linux_nat_target::attach (const char *args, int from_tty) | |
d6b0e80f AC |
1180 | { |
1181 | struct lwp_info *lp; | |
d6b0e80f | 1182 | int status; |
af990527 | 1183 | ptid_t ptid; |
d6b0e80f | 1184 | |
2455069d | 1185 | /* Make sure we report all signals during attach. */ |
adc6a863 | 1186 | pass_signals ({}); |
2455069d | 1187 | |
a70b8144 | 1188 | try |
87b0bb13 | 1189 | { |
f6ac5f3d | 1190 | inf_ptrace_target::attach (args, from_tty); |
87b0bb13 | 1191 | } |
230d2906 | 1192 | catch (const gdb_exception_error &ex) |
87b0bb13 JK |
1193 | { |
1194 | pid_t pid = parse_pid_to_attach (args); | |
50fa3001 | 1195 | std::string reason = linux_ptrace_attach_fail_reason (pid); |
87b0bb13 | 1196 | |
4d9b86e1 | 1197 | if (!reason.empty ()) |
3d6e9d23 TT |
1198 | throw_error (ex.error, "warning: %s\n%s", reason.c_str (), |
1199 | ex.what ()); | |
7ae1a6a6 | 1200 | else |
3d6e9d23 | 1201 | throw_error (ex.error, "%s", ex.what ()); |
87b0bb13 | 1202 | } |
d6b0e80f | 1203 | |
af990527 PA |
1204 | /* The ptrace base target adds the main thread with (pid,0,0) |
1205 | format. Decorate it with lwp info. */ | |
e99b03dc TT |
1206 | ptid = ptid_t (inferior_ptid.pid (), |
1207 | inferior_ptid.pid (), | |
fd79271b | 1208 | 0); |
5b6d1e4f | 1209 | thread_change_ptid (linux_target, inferior_ptid, ptid); |
af990527 | 1210 | |
9f0bdab8 | 1211 | /* Add the initial process as the first LWP to the list. */ |
26cb8b7c | 1212 | lp = add_initial_lwp (ptid); |
a0ef4274 | 1213 | |
22827c51 | 1214 | status = linux_nat_post_attach_wait (lp->ptid, &lp->signalled); |
dacc9cb2 PP |
1215 | if (!WIFSTOPPED (status)) |
1216 | { | |
1217 | if (WIFEXITED (status)) | |
1218 | { | |
1219 | int exit_code = WEXITSTATUS (status); | |
1220 | ||
223ffa71 | 1221 | target_terminal::ours (); |
bc1e6c81 | 1222 | target_mourn_inferior (inferior_ptid); |
dacc9cb2 PP |
1223 | if (exit_code == 0) |
1224 | error (_("Unable to attach: program exited normally.")); | |
1225 | else | |
1226 | error (_("Unable to attach: program exited with code %d."), | |
1227 | exit_code); | |
1228 | } | |
1229 | else if (WIFSIGNALED (status)) | |
1230 | { | |
2ea28649 | 1231 | enum gdb_signal signo; |
dacc9cb2 | 1232 | |
223ffa71 | 1233 | target_terminal::ours (); |
bc1e6c81 | 1234 | target_mourn_inferior (inferior_ptid); |
dacc9cb2 | 1235 | |
2ea28649 | 1236 | signo = gdb_signal_from_host (WTERMSIG (status)); |
dacc9cb2 PP |
1237 | error (_("Unable to attach: program terminated with signal " |
1238 | "%s, %s."), | |
2ea28649 PA |
1239 | gdb_signal_to_name (signo), |
1240 | gdb_signal_to_string (signo)); | |
dacc9cb2 PP |
1241 | } |
1242 | ||
1243 | internal_error (__FILE__, __LINE__, | |
1244 | _("unexpected status %d for PID %ld"), | |
e38504b3 | 1245 | status, (long) ptid.lwp ()); |
dacc9cb2 PP |
1246 | } |
1247 | ||
a0ef4274 | 1248 | lp->stopped = 1; |
9f0bdab8 | 1249 | |
a0ef4274 | 1250 | /* Save the wait status to report later. */ |
d6b0e80f | 1251 | lp->resumed = 1; |
a0ef4274 DJ |
1252 | if (debug_linux_nat) |
1253 | fprintf_unfiltered (gdb_stdlog, | |
1254 | "LNA: waitpid %ld, saving status %s\n", | |
e99b03dc | 1255 | (long) lp->ptid.pid (), status_to_str (status)); |
710151dd | 1256 | |
7feb7d06 PA |
1257 | lp->status = status; |
1258 | ||
8784d563 PA |
1259 | /* We must attach to every LWP. If /proc is mounted, use that to |
1260 | find them now. The inferior may be using raw clone instead of | |
1261 | using pthreads. But even if it is using pthreads, thread_db | |
1262 | walks structures in the inferior's address space to find the list | |
1263 | of threads/LWPs, and those structures may well be corrupted. | |
1264 | Note that once thread_db is loaded, we'll still use it to list | |
1265 | threads and associate pthread info with each LWP. */ | |
e99b03dc | 1266 | linux_proc_attach_tgid_threads (lp->ptid.pid (), |
8784d563 PA |
1267 | attach_proc_task_lwp_callback); |
1268 | ||
7feb7d06 | 1269 | if (target_can_async_p ()) |
6a3753b3 | 1270 | target_async (1); |
d6b0e80f AC |
1271 | } |
1272 | ||
ced2dffb PA |
1273 | /* Get pending signal of THREAD as a host signal number, for detaching |
1274 | purposes. This is the signal the thread last stopped for, which we | |
1275 | need to deliver to the thread when detaching, otherwise, it'd be | |
1276 | suppressed/lost. */ | |
1277 | ||
a0ef4274 | 1278 | static int |
ced2dffb | 1279 | get_detach_signal (struct lwp_info *lp) |
a0ef4274 | 1280 | { |
a493e3e2 | 1281 | enum gdb_signal signo = GDB_SIGNAL_0; |
ca2163eb PA |
1282 | |
1283 | /* If we paused threads momentarily, we may have stored pending | |
1284 | events in lp->status or lp->waitstatus (see stop_wait_callback), | |
1285 | and GDB core hasn't seen any signal for those threads. | |
1286 | Otherwise, the last signal reported to the core is found in the | |
1287 | thread object's stop_signal. | |
1288 | ||
1289 | There's a corner case that isn't handled here at present. Only | |
1290 | if the thread stopped with a TARGET_WAITKIND_STOPPED does | |
1291 | stop_signal make sense as a real signal to pass to the inferior. | |
1292 | Some catchpoint related events, like | |
1293 | TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set | |
a493e3e2 | 1294 | to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But, |
ca2163eb PA |
1295 | those traps are debug API (ptrace in our case) related and |
1296 | induced; the inferior wouldn't see them if it wasn't being | |
1297 | traced. Hence, we should never pass them to the inferior, even | |
1298 | when set to pass state. Since this corner case isn't handled by | |
1299 | infrun.c when proceeding with a signal, for consistency, neither | |
1300 | do we handle it here (or elsewhere in the file we check for | |
1301 | signal pass state). Normally SIGTRAP isn't set to pass state, so | |
1302 | this is really a corner case. */ | |
1303 | ||
1304 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
a493e3e2 | 1305 | signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */ |
ca2163eb | 1306 | else if (lp->status) |
2ea28649 | 1307 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
00431a78 | 1308 | else |
ca2163eb | 1309 | { |
5b6d1e4f | 1310 | struct thread_info *tp = find_thread_ptid (linux_target, lp->ptid); |
e0881a8e | 1311 | |
00431a78 | 1312 | if (target_is_non_stop_p () && !tp->executing) |
ca2163eb | 1313 | { |
00431a78 PA |
1314 | if (tp->suspend.waitstatus_pending_p) |
1315 | signo = tp->suspend.waitstatus.value.sig; | |
1316 | else | |
1317 | signo = tp->suspend.stop_signal; | |
1318 | } | |
1319 | else if (!target_is_non_stop_p ()) | |
1320 | { | |
00431a78 | 1321 | ptid_t last_ptid; |
5b6d1e4f | 1322 | process_stratum_target *last_target; |
00431a78 | 1323 | |
5b6d1e4f | 1324 | get_last_target_status (&last_target, &last_ptid, nullptr); |
e0881a8e | 1325 | |
5b6d1e4f PA |
1326 | if (last_target == linux_target |
1327 | && lp->ptid.lwp () == last_ptid.lwp ()) | |
00431a78 | 1328 | signo = tp->suspend.stop_signal; |
4c28f408 | 1329 | } |
ca2163eb | 1330 | } |
4c28f408 | 1331 | |
a493e3e2 | 1332 | if (signo == GDB_SIGNAL_0) |
ca2163eb PA |
1333 | { |
1334 | if (debug_linux_nat) | |
1335 | fprintf_unfiltered (gdb_stdlog, | |
1336 | "GPT: lwp %s has no pending signal\n", | |
a068643d | 1337 | target_pid_to_str (lp->ptid).c_str ()); |
ca2163eb PA |
1338 | } |
1339 | else if (!signal_pass_state (signo)) | |
1340 | { | |
1341 | if (debug_linux_nat) | |
3e43a32a MS |
1342 | fprintf_unfiltered (gdb_stdlog, |
1343 | "GPT: lwp %s had signal %s, " | |
1344 | "but it is in no pass state\n", | |
a068643d | 1345 | target_pid_to_str (lp->ptid).c_str (), |
2ea28649 | 1346 | gdb_signal_to_string (signo)); |
a0ef4274 | 1347 | } |
a0ef4274 | 1348 | else |
4c28f408 | 1349 | { |
ca2163eb PA |
1350 | if (debug_linux_nat) |
1351 | fprintf_unfiltered (gdb_stdlog, | |
1352 | "GPT: lwp %s has pending signal %s\n", | |
a068643d | 1353 | target_pid_to_str (lp->ptid).c_str (), |
2ea28649 | 1354 | gdb_signal_to_string (signo)); |
ced2dffb PA |
1355 | |
1356 | return gdb_signal_to_host (signo); | |
4c28f408 | 1357 | } |
a0ef4274 DJ |
1358 | |
1359 | return 0; | |
1360 | } | |
1361 | ||
ced2dffb PA |
1362 | /* Detach from LP. If SIGNO_P is non-NULL, then it points to the |
1363 | signal number that should be passed to the LWP when detaching. | |
1364 | Otherwise pass any pending signal the LWP may have, if any. */ | |
1365 | ||
1366 | static void | |
1367 | detach_one_lwp (struct lwp_info *lp, int *signo_p) | |
d6b0e80f | 1368 | { |
e38504b3 | 1369 | int lwpid = lp->ptid.lwp (); |
ced2dffb PA |
1370 | int signo; |
1371 | ||
d6b0e80f AC |
1372 | gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status)); |
1373 | ||
1374 | if (debug_linux_nat && lp->status) | |
1375 | fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n", | |
1376 | strsignal (WSTOPSIG (lp->status)), | |
a068643d | 1377 | target_pid_to_str (lp->ptid).c_str ()); |
d6b0e80f | 1378 | |
a0ef4274 DJ |
1379 | /* If there is a pending SIGSTOP, get rid of it. */ |
1380 | if (lp->signalled) | |
d6b0e80f | 1381 | { |
d6b0e80f AC |
1382 | if (debug_linux_nat) |
1383 | fprintf_unfiltered (gdb_stdlog, | |
a0ef4274 | 1384 | "DC: Sending SIGCONT to %s\n", |
a068643d | 1385 | target_pid_to_str (lp->ptid).c_str ()); |
d6b0e80f | 1386 | |
ced2dffb | 1387 | kill_lwp (lwpid, SIGCONT); |
d6b0e80f | 1388 | lp->signalled = 0; |
d6b0e80f AC |
1389 | } |
1390 | ||
ced2dffb | 1391 | if (signo_p == NULL) |
d6b0e80f | 1392 | { |
a0ef4274 | 1393 | /* Pass on any pending signal for this LWP. */ |
ced2dffb PA |
1394 | signo = get_detach_signal (lp); |
1395 | } | |
1396 | else | |
1397 | signo = *signo_p; | |
a0ef4274 | 1398 | |
ced2dffb PA |
1399 | /* Preparing to resume may try to write registers, and fail if the |
1400 | lwp is zombie. If that happens, ignore the error. We'll handle | |
1401 | it below, when detach fails with ESRCH. */ | |
a70b8144 | 1402 | try |
ced2dffb | 1403 | { |
135340af | 1404 | linux_target->low_prepare_to_resume (lp); |
ced2dffb | 1405 | } |
230d2906 | 1406 | catch (const gdb_exception_error &ex) |
ced2dffb PA |
1407 | { |
1408 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 1409 | throw; |
ced2dffb | 1410 | } |
d6b0e80f | 1411 | |
ced2dffb PA |
1412 | if (ptrace (PTRACE_DETACH, lwpid, 0, signo) < 0) |
1413 | { | |
1414 | int save_errno = errno; | |
1415 | ||
1416 | /* We know the thread exists, so ESRCH must mean the lwp is | |
1417 | zombie. This can happen if one of the already-detached | |
1418 | threads exits the whole thread group. In that case we're | |
1419 | still attached, and must reap the lwp. */ | |
1420 | if (save_errno == ESRCH) | |
1421 | { | |
1422 | int ret, status; | |
d6b0e80f | 1423 | |
ced2dffb PA |
1424 | ret = my_waitpid (lwpid, &status, __WALL); |
1425 | if (ret == -1) | |
1426 | { | |
1427 | warning (_("Couldn't reap LWP %d while detaching: %s"), | |
6d91ce9a | 1428 | lwpid, safe_strerror (errno)); |
ced2dffb PA |
1429 | } |
1430 | else if (!WIFEXITED (status) && !WIFSIGNALED (status)) | |
1431 | { | |
1432 | warning (_("Reaping LWP %d while detaching " | |
1433 | "returned unexpected status 0x%x"), | |
1434 | lwpid, status); | |
1435 | } | |
1436 | } | |
1437 | else | |
1438 | { | |
a068643d TT |
1439 | error (_("Can't detach %s: %s"), |
1440 | target_pid_to_str (lp->ptid).c_str (), | |
ced2dffb PA |
1441 | safe_strerror (save_errno)); |
1442 | } | |
d6b0e80f | 1443 | } |
ced2dffb PA |
1444 | else if (debug_linux_nat) |
1445 | { | |
1446 | fprintf_unfiltered (gdb_stdlog, | |
1447 | "PTRACE_DETACH (%s, %s, 0) (OK)\n", | |
a068643d | 1448 | target_pid_to_str (lp->ptid).c_str (), |
ced2dffb PA |
1449 | strsignal (signo)); |
1450 | } | |
1451 | ||
1452 | delete_lwp (lp->ptid); | |
1453 | } | |
d6b0e80f | 1454 | |
ced2dffb | 1455 | static int |
d3a70e03 | 1456 | detach_callback (struct lwp_info *lp) |
ced2dffb PA |
1457 | { |
1458 | /* We don't actually detach from the thread group leader just yet. | |
1459 | If the thread group exits, we must reap the zombie clone lwps | |
1460 | before we're able to reap the leader. */ | |
e38504b3 | 1461 | if (lp->ptid.lwp () != lp->ptid.pid ()) |
ced2dffb | 1462 | detach_one_lwp (lp, NULL); |
d6b0e80f AC |
1463 | return 0; |
1464 | } | |
1465 | ||
f6ac5f3d PA |
1466 | void |
1467 | linux_nat_target::detach (inferior *inf, int from_tty) | |
d6b0e80f | 1468 | { |
d90e17a7 | 1469 | struct lwp_info *main_lwp; |
bc09b0c1 | 1470 | int pid = inf->pid; |
a0ef4274 | 1471 | |
ae5e0686 MK |
1472 | /* Don't unregister from the event loop, as there may be other |
1473 | inferiors running. */ | |
b84876c2 | 1474 | |
4c28f408 | 1475 | /* Stop all threads before detaching. ptrace requires that the |
30baf67b | 1476 | thread is stopped to successfully detach. */ |
d3a70e03 | 1477 | iterate_over_lwps (ptid_t (pid), stop_callback); |
4c28f408 PA |
1478 | /* ... and wait until all of them have reported back that |
1479 | they're no longer running. */ | |
d3a70e03 | 1480 | iterate_over_lwps (ptid_t (pid), stop_wait_callback); |
4c28f408 | 1481 | |
d3a70e03 | 1482 | iterate_over_lwps (ptid_t (pid), detach_callback); |
d6b0e80f AC |
1483 | |
1484 | /* Only the initial process should be left right now. */ | |
bc09b0c1 | 1485 | gdb_assert (num_lwps (pid) == 1); |
d90e17a7 | 1486 | |
f2907e49 | 1487 | main_lwp = find_lwp_pid (ptid_t (pid)); |
d6b0e80f | 1488 | |
7a7d3353 PA |
1489 | if (forks_exist_p ()) |
1490 | { | |
1491 | /* Multi-fork case. The current inferior_ptid is being detached | |
1492 | from, but there are other viable forks to debug. Detach from | |
1493 | the current fork, and context-switch to the first | |
1494 | available. */ | |
6bd6f3b6 | 1495 | linux_fork_detach (from_tty); |
7a7d3353 PA |
1496 | } |
1497 | else | |
ced2dffb | 1498 | { |
ced2dffb PA |
1499 | target_announce_detach (from_tty); |
1500 | ||
6bd6f3b6 SM |
1501 | /* Pass on any pending signal for the last LWP. */ |
1502 | int signo = get_detach_signal (main_lwp); | |
ced2dffb PA |
1503 | |
1504 | detach_one_lwp (main_lwp, &signo); | |
1505 | ||
f6ac5f3d | 1506 | detach_success (inf); |
ced2dffb | 1507 | } |
d6b0e80f AC |
1508 | } |
1509 | ||
8a99810d PA |
1510 | /* Resume execution of the inferior process. If STEP is nonzero, |
1511 | single-step it. If SIGNAL is nonzero, give it that signal. */ | |
1512 | ||
1513 | static void | |
23f238d3 PA |
1514 | linux_resume_one_lwp_throw (struct lwp_info *lp, int step, |
1515 | enum gdb_signal signo) | |
8a99810d | 1516 | { |
8a99810d | 1517 | lp->step = step; |
9c02b525 PA |
1518 | |
1519 | /* stop_pc doubles as the PC the LWP had when it was last resumed. | |
1520 | We only presently need that if the LWP is stepped though (to | |
1521 | handle the case of stepping a breakpoint instruction). */ | |
1522 | if (step) | |
1523 | { | |
5b6d1e4f | 1524 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
9c02b525 PA |
1525 | |
1526 | lp->stop_pc = regcache_read_pc (regcache); | |
1527 | } | |
1528 | else | |
1529 | lp->stop_pc = 0; | |
1530 | ||
135340af | 1531 | linux_target->low_prepare_to_resume (lp); |
f6ac5f3d | 1532 | linux_target->low_resume (lp->ptid, step, signo); |
23f238d3 PA |
1533 | |
1534 | /* Successfully resumed. Clear state that no longer makes sense, | |
1535 | and mark the LWP as running. Must not do this before resuming | |
1536 | otherwise if that fails other code will be confused. E.g., we'd | |
1537 | later try to stop the LWP and hang forever waiting for a stop | |
1538 | status. Note that we must not throw after this is cleared, | |
1539 | otherwise handle_zombie_lwp_error would get confused. */ | |
8a99810d | 1540 | lp->stopped = 0; |
1ad3de98 | 1541 | lp->core = -1; |
23f238d3 | 1542 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; |
5b6d1e4f | 1543 | registers_changed_ptid (linux_target, lp->ptid); |
8a99810d PA |
1544 | } |
1545 | ||
23f238d3 PA |
1546 | /* Called when we try to resume a stopped LWP and that errors out. If |
1547 | the LWP is no longer in ptrace-stopped state (meaning it's zombie, | |
1548 | or about to become), discard the error, clear any pending status | |
1549 | the LWP may have, and return true (we'll collect the exit status | |
1550 | soon enough). Otherwise, return false. */ | |
1551 | ||
1552 | static int | |
1553 | check_ptrace_stopped_lwp_gone (struct lwp_info *lp) | |
1554 | { | |
1555 | /* If we get an error after resuming the LWP successfully, we'd | |
1556 | confuse !T state for the LWP being gone. */ | |
1557 | gdb_assert (lp->stopped); | |
1558 | ||
1559 | /* We can't just check whether the LWP is in 'Z (Zombie)' state, | |
1560 | because even if ptrace failed with ESRCH, the tracee may be "not | |
1561 | yet fully dead", but already refusing ptrace requests. In that | |
1562 | case the tracee has 'R (Running)' state for a little bit | |
1563 | (observed in Linux 3.18). See also the note on ESRCH in the | |
1564 | ptrace(2) man page. Instead, check whether the LWP has any state | |
1565 | other than ptrace-stopped. */ | |
1566 | ||
1567 | /* Don't assume anything if /proc/PID/status can't be read. */ | |
e38504b3 | 1568 | if (linux_proc_pid_is_trace_stopped_nowarn (lp->ptid.lwp ()) == 0) |
23f238d3 PA |
1569 | { |
1570 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; | |
1571 | lp->status = 0; | |
1572 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
1573 | return 1; | |
1574 | } | |
1575 | return 0; | |
1576 | } | |
1577 | ||
1578 | /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP | |
1579 | disappears while we try to resume it. */ | |
1580 | ||
1581 | static void | |
1582 | linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) | |
1583 | { | |
a70b8144 | 1584 | try |
23f238d3 PA |
1585 | { |
1586 | linux_resume_one_lwp_throw (lp, step, signo); | |
1587 | } | |
230d2906 | 1588 | catch (const gdb_exception_error &ex) |
23f238d3 PA |
1589 | { |
1590 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 1591 | throw; |
23f238d3 | 1592 | } |
23f238d3 PA |
1593 | } |
1594 | ||
d6b0e80f AC |
1595 | /* Resume LP. */ |
1596 | ||
25289eb2 | 1597 | static void |
e5ef252a | 1598 | resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) |
d6b0e80f | 1599 | { |
25289eb2 | 1600 | if (lp->stopped) |
6c95b8df | 1601 | { |
5b6d1e4f | 1602 | struct inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
25289eb2 PA |
1603 | |
1604 | if (inf->vfork_child != NULL) | |
1605 | { | |
1606 | if (debug_linux_nat) | |
1607 | fprintf_unfiltered (gdb_stdlog, | |
1608 | "RC: Not resuming %s (vfork parent)\n", | |
a068643d | 1609 | target_pid_to_str (lp->ptid).c_str ()); |
25289eb2 | 1610 | } |
8a99810d | 1611 | else if (!lwp_status_pending_p (lp)) |
25289eb2 PA |
1612 | { |
1613 | if (debug_linux_nat) | |
1614 | fprintf_unfiltered (gdb_stdlog, | |
e5ef252a | 1615 | "RC: Resuming sibling %s, %s, %s\n", |
a068643d | 1616 | target_pid_to_str (lp->ptid).c_str (), |
e5ef252a PA |
1617 | (signo != GDB_SIGNAL_0 |
1618 | ? strsignal (gdb_signal_to_host (signo)) | |
1619 | : "0"), | |
1620 | step ? "step" : "resume"); | |
25289eb2 | 1621 | |
8a99810d | 1622 | linux_resume_one_lwp (lp, step, signo); |
25289eb2 PA |
1623 | } |
1624 | else | |
1625 | { | |
1626 | if (debug_linux_nat) | |
1627 | fprintf_unfiltered (gdb_stdlog, | |
1628 | "RC: Not resuming sibling %s (has pending)\n", | |
a068643d | 1629 | target_pid_to_str (lp->ptid).c_str ()); |
25289eb2 | 1630 | } |
6c95b8df | 1631 | } |
25289eb2 | 1632 | else |
d6b0e80f | 1633 | { |
d90e17a7 PA |
1634 | if (debug_linux_nat) |
1635 | fprintf_unfiltered (gdb_stdlog, | |
25289eb2 | 1636 | "RC: Not resuming sibling %s (not stopped)\n", |
a068643d | 1637 | target_pid_to_str (lp->ptid).c_str ()); |
d6b0e80f | 1638 | } |
25289eb2 | 1639 | } |
d6b0e80f | 1640 | |
8817a6f2 PA |
1641 | /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing. |
1642 | Resume LWP with the last stop signal, if it is in pass state. */ | |
e5ef252a | 1643 | |
25289eb2 | 1644 | static int |
d3a70e03 | 1645 | linux_nat_resume_callback (struct lwp_info *lp, struct lwp_info *except) |
25289eb2 | 1646 | { |
e5ef252a PA |
1647 | enum gdb_signal signo = GDB_SIGNAL_0; |
1648 | ||
8817a6f2 PA |
1649 | if (lp == except) |
1650 | return 0; | |
1651 | ||
e5ef252a PA |
1652 | if (lp->stopped) |
1653 | { | |
1654 | struct thread_info *thread; | |
1655 | ||
5b6d1e4f | 1656 | thread = find_thread_ptid (linux_target, lp->ptid); |
e5ef252a PA |
1657 | if (thread != NULL) |
1658 | { | |
70509625 | 1659 | signo = thread->suspend.stop_signal; |
e5ef252a PA |
1660 | thread->suspend.stop_signal = GDB_SIGNAL_0; |
1661 | } | |
1662 | } | |
1663 | ||
1664 | resume_lwp (lp, 0, signo); | |
d6b0e80f AC |
1665 | return 0; |
1666 | } | |
1667 | ||
1668 | static int | |
d3a70e03 | 1669 | resume_clear_callback (struct lwp_info *lp) |
d6b0e80f AC |
1670 | { |
1671 | lp->resumed = 0; | |
25289eb2 | 1672 | lp->last_resume_kind = resume_stop; |
d6b0e80f AC |
1673 | return 0; |
1674 | } | |
1675 | ||
1676 | static int | |
d3a70e03 | 1677 | resume_set_callback (struct lwp_info *lp) |
d6b0e80f AC |
1678 | { |
1679 | lp->resumed = 1; | |
25289eb2 | 1680 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1681 | return 0; |
1682 | } | |
1683 | ||
f6ac5f3d PA |
1684 | void |
1685 | linux_nat_target::resume (ptid_t ptid, int step, enum gdb_signal signo) | |
d6b0e80f AC |
1686 | { |
1687 | struct lwp_info *lp; | |
d90e17a7 | 1688 | int resume_many; |
d6b0e80f | 1689 | |
76f50ad1 DJ |
1690 | if (debug_linux_nat) |
1691 | fprintf_unfiltered (gdb_stdlog, | |
1692 | "LLR: Preparing to %s %s, %s, inferior_ptid %s\n", | |
1693 | step ? "step" : "resume", | |
a068643d | 1694 | target_pid_to_str (ptid).c_str (), |
a493e3e2 | 1695 | (signo != GDB_SIGNAL_0 |
2ea28649 | 1696 | ? strsignal (gdb_signal_to_host (signo)) : "0"), |
a068643d | 1697 | target_pid_to_str (inferior_ptid).c_str ()); |
76f50ad1 | 1698 | |
d6b0e80f | 1699 | /* A specific PTID means `step only this process id'. */ |
d7e15655 | 1700 | resume_many = (minus_one_ptid == ptid |
0e998d96 | 1701 | || ptid.is_pid ()); |
4c28f408 | 1702 | |
e3e9f5a2 | 1703 | /* Mark the lwps we're resuming as resumed. */ |
d3a70e03 | 1704 | iterate_over_lwps (ptid, resume_set_callback); |
d6b0e80f | 1705 | |
d90e17a7 PA |
1706 | /* See if it's the current inferior that should be handled |
1707 | specially. */ | |
1708 | if (resume_many) | |
1709 | lp = find_lwp_pid (inferior_ptid); | |
1710 | else | |
1711 | lp = find_lwp_pid (ptid); | |
9f0bdab8 | 1712 | gdb_assert (lp != NULL); |
d6b0e80f | 1713 | |
9f0bdab8 | 1714 | /* Remember if we're stepping. */ |
25289eb2 | 1715 | lp->last_resume_kind = step ? resume_step : resume_continue; |
d6b0e80f | 1716 | |
9f0bdab8 DJ |
1717 | /* If we have a pending wait status for this thread, there is no |
1718 | point in resuming the process. But first make sure that | |
1719 | linux_nat_wait won't preemptively handle the event - we | |
1720 | should never take this short-circuit if we are going to | |
1721 | leave LP running, since we have skipped resuming all the | |
1722 | other threads. This bit of code needs to be synchronized | |
1723 | with linux_nat_wait. */ | |
76f50ad1 | 1724 | |
9f0bdab8 DJ |
1725 | if (lp->status && WIFSTOPPED (lp->status)) |
1726 | { | |
2455069d UW |
1727 | if (!lp->step |
1728 | && WSTOPSIG (lp->status) | |
1729 | && sigismember (&pass_mask, WSTOPSIG (lp->status))) | |
d6b0e80f | 1730 | { |
9f0bdab8 DJ |
1731 | if (debug_linux_nat) |
1732 | fprintf_unfiltered (gdb_stdlog, | |
1733 | "LLR: Not short circuiting for ignored " | |
1734 | "status 0x%x\n", lp->status); | |
1735 | ||
d6b0e80f AC |
1736 | /* FIXME: What should we do if we are supposed to continue |
1737 | this thread with a signal? */ | |
a493e3e2 | 1738 | gdb_assert (signo == GDB_SIGNAL_0); |
2ea28649 | 1739 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
9f0bdab8 DJ |
1740 | lp->status = 0; |
1741 | } | |
1742 | } | |
76f50ad1 | 1743 | |
8a99810d | 1744 | if (lwp_status_pending_p (lp)) |
9f0bdab8 DJ |
1745 | { |
1746 | /* FIXME: What should we do if we are supposed to continue | |
1747 | this thread with a signal? */ | |
a493e3e2 | 1748 | gdb_assert (signo == GDB_SIGNAL_0); |
76f50ad1 | 1749 | |
9f0bdab8 DJ |
1750 | if (debug_linux_nat) |
1751 | fprintf_unfiltered (gdb_stdlog, | |
1752 | "LLR: Short circuiting for status 0x%x\n", | |
1753 | lp->status); | |
d6b0e80f | 1754 | |
7feb7d06 PA |
1755 | if (target_can_async_p ()) |
1756 | { | |
6a3753b3 | 1757 | target_async (1); |
7feb7d06 PA |
1758 | /* Tell the event loop we have something to process. */ |
1759 | async_file_mark (); | |
1760 | } | |
9f0bdab8 | 1761 | return; |
d6b0e80f AC |
1762 | } |
1763 | ||
d90e17a7 | 1764 | if (resume_many) |
d3a70e03 TT |
1765 | iterate_over_lwps (ptid, [=] (struct lwp_info *info) |
1766 | { | |
1767 | return linux_nat_resume_callback (info, lp); | |
1768 | }); | |
d90e17a7 | 1769 | |
d6b0e80f AC |
1770 | if (debug_linux_nat) |
1771 | fprintf_unfiltered (gdb_stdlog, | |
1772 | "LLR: %s %s, %s (resume event thread)\n", | |
1773 | step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
a068643d | 1774 | target_pid_to_str (lp->ptid).c_str (), |
a493e3e2 | 1775 | (signo != GDB_SIGNAL_0 |
2ea28649 | 1776 | ? strsignal (gdb_signal_to_host (signo)) : "0")); |
b84876c2 | 1777 | |
2bf6fb9d PA |
1778 | linux_resume_one_lwp (lp, step, signo); |
1779 | ||
b84876c2 | 1780 | if (target_can_async_p ()) |
6a3753b3 | 1781 | target_async (1); |
d6b0e80f AC |
1782 | } |
1783 | ||
c5f62d5f | 1784 | /* Send a signal to an LWP. */ |
d6b0e80f AC |
1785 | |
1786 | static int | |
1787 | kill_lwp (int lwpid, int signo) | |
1788 | { | |
4a6ed09b | 1789 | int ret; |
d6b0e80f | 1790 | |
4a6ed09b PA |
1791 | errno = 0; |
1792 | ret = syscall (__NR_tkill, lwpid, signo); | |
1793 | if (errno == ENOSYS) | |
1794 | { | |
1795 | /* If tkill fails, then we are not using nptl threads, a | |
1796 | configuration we no longer support. */ | |
1797 | perror_with_name (("tkill")); | |
1798 | } | |
1799 | return ret; | |
d6b0e80f AC |
1800 | } |
1801 | ||
ca2163eb PA |
1802 | /* Handle a GNU/Linux syscall trap wait response. If we see a syscall |
1803 | event, check if the core is interested in it: if not, ignore the | |
1804 | event, and keep waiting; otherwise, we need to toggle the LWP's | |
1805 | syscall entry/exit status, since the ptrace event itself doesn't | |
1806 | indicate it, and report the trap to higher layers. */ | |
1807 | ||
1808 | static int | |
1809 | linux_handle_syscall_trap (struct lwp_info *lp, int stopping) | |
1810 | { | |
1811 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
1812 | struct gdbarch *gdbarch = target_thread_architecture (lp->ptid); | |
5b6d1e4f | 1813 | thread_info *thread = find_thread_ptid (linux_target, lp->ptid); |
00431a78 | 1814 | int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, thread); |
ca2163eb PA |
1815 | |
1816 | if (stopping) | |
1817 | { | |
1818 | /* If we're stopping threads, there's a SIGSTOP pending, which | |
1819 | makes it so that the LWP reports an immediate syscall return, | |
1820 | followed by the SIGSTOP. Skip seeing that "return" using | |
1821 | PTRACE_CONT directly, and let stop_wait_callback collect the | |
1822 | SIGSTOP. Later when the thread is resumed, a new syscall | |
1823 | entry event. If we didn't do this (and returned 0), we'd | |
1824 | leave a syscall entry pending, and our caller, by using | |
1825 | PTRACE_CONT to collect the SIGSTOP, skips the syscall return | |
1826 | itself. Later, when the user re-resumes this LWP, we'd see | |
1827 | another syscall entry event and we'd mistake it for a return. | |
1828 | ||
1829 | If stop_wait_callback didn't force the SIGSTOP out of the LWP | |
1830 | (leaving immediately with LWP->signalled set, without issuing | |
1831 | a PTRACE_CONT), it would still be problematic to leave this | |
1832 | syscall enter pending, as later when the thread is resumed, | |
1833 | it would then see the same syscall exit mentioned above, | |
1834 | followed by the delayed SIGSTOP, while the syscall didn't | |
1835 | actually get to execute. It seems it would be even more | |
1836 | confusing to the user. */ | |
1837 | ||
1838 | if (debug_linux_nat) | |
1839 | fprintf_unfiltered (gdb_stdlog, | |
1840 | "LHST: ignoring syscall %d " | |
1841 | "for LWP %ld (stopping threads), " | |
1842 | "resuming with PTRACE_CONT for SIGSTOP\n", | |
1843 | syscall_number, | |
e38504b3 | 1844 | lp->ptid.lwp ()); |
ca2163eb PA |
1845 | |
1846 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
e38504b3 | 1847 | ptrace (PTRACE_CONT, lp->ptid.lwp (), 0, 0); |
8817a6f2 | 1848 | lp->stopped = 0; |
ca2163eb PA |
1849 | return 1; |
1850 | } | |
1851 | ||
bfd09d20 JS |
1852 | /* Always update the entry/return state, even if this particular |
1853 | syscall isn't interesting to the core now. In async mode, | |
1854 | the user could install a new catchpoint for this syscall | |
1855 | between syscall enter/return, and we'll need to know to | |
1856 | report a syscall return if that happens. */ | |
1857 | lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1858 | ? TARGET_WAITKIND_SYSCALL_RETURN | |
1859 | : TARGET_WAITKIND_SYSCALL_ENTRY); | |
1860 | ||
ca2163eb PA |
1861 | if (catch_syscall_enabled ()) |
1862 | { | |
ca2163eb PA |
1863 | if (catching_syscall_number (syscall_number)) |
1864 | { | |
1865 | /* Alright, an event to report. */ | |
1866 | ourstatus->kind = lp->syscall_state; | |
1867 | ourstatus->value.syscall_number = syscall_number; | |
1868 | ||
1869 | if (debug_linux_nat) | |
1870 | fprintf_unfiltered (gdb_stdlog, | |
1871 | "LHST: stopping for %s of syscall %d" | |
1872 | " for LWP %ld\n", | |
3e43a32a MS |
1873 | lp->syscall_state |
1874 | == TARGET_WAITKIND_SYSCALL_ENTRY | |
ca2163eb PA |
1875 | ? "entry" : "return", |
1876 | syscall_number, | |
e38504b3 | 1877 | lp->ptid.lwp ()); |
ca2163eb PA |
1878 | return 0; |
1879 | } | |
1880 | ||
1881 | if (debug_linux_nat) | |
1882 | fprintf_unfiltered (gdb_stdlog, | |
1883 | "LHST: ignoring %s of syscall %d " | |
1884 | "for LWP %ld\n", | |
1885 | lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1886 | ? "entry" : "return", | |
1887 | syscall_number, | |
e38504b3 | 1888 | lp->ptid.lwp ()); |
ca2163eb PA |
1889 | } |
1890 | else | |
1891 | { | |
1892 | /* If we had been syscall tracing, and hence used PT_SYSCALL | |
1893 | before on this LWP, it could happen that the user removes all | |
1894 | syscall catchpoints before we get to process this event. | |
1895 | There are two noteworthy issues here: | |
1896 | ||
1897 | - When stopped at a syscall entry event, resuming with | |
1898 | PT_STEP still resumes executing the syscall and reports a | |
1899 | syscall return. | |
1900 | ||
1901 | - Only PT_SYSCALL catches syscall enters. If we last | |
1902 | single-stepped this thread, then this event can't be a | |
1903 | syscall enter. If we last single-stepped this thread, this | |
1904 | has to be a syscall exit. | |
1905 | ||
1906 | The points above mean that the next resume, be it PT_STEP or | |
1907 | PT_CONTINUE, can not trigger a syscall trace event. */ | |
1908 | if (debug_linux_nat) | |
1909 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
1910 | "LHST: caught syscall event " |
1911 | "with no syscall catchpoints." | |
ca2163eb PA |
1912 | " %d for LWP %ld, ignoring\n", |
1913 | syscall_number, | |
e38504b3 | 1914 | lp->ptid.lwp ()); |
ca2163eb PA |
1915 | lp->syscall_state = TARGET_WAITKIND_IGNORE; |
1916 | } | |
1917 | ||
1918 | /* The core isn't interested in this event. For efficiency, avoid | |
1919 | stopping all threads only to have the core resume them all again. | |
1920 | Since we're not stopping threads, if we're still syscall tracing | |
1921 | and not stepping, we can't use PTRACE_CONT here, as we'd miss any | |
1922 | subsequent syscall. Simply resume using the inf-ptrace layer, | |
1923 | which knows when to use PT_SYSCALL or PT_CONTINUE. */ | |
1924 | ||
8a99810d | 1925 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
ca2163eb PA |
1926 | return 1; |
1927 | } | |
1928 | ||
3d799a95 DJ |
1929 | /* Handle a GNU/Linux extended wait response. If we see a clone |
1930 | event, we need to add the new LWP to our list (and not report the | |
1931 | trap to higher layers). This function returns non-zero if the | |
1932 | event should be ignored and we should wait again. If STOPPING is | |
1933 | true, the new LWP remains stopped, otherwise it is continued. */ | |
d6b0e80f AC |
1934 | |
1935 | static int | |
4dd63d48 | 1936 | linux_handle_extended_wait (struct lwp_info *lp, int status) |
d6b0e80f | 1937 | { |
e38504b3 | 1938 | int pid = lp->ptid.lwp (); |
3d799a95 | 1939 | struct target_waitstatus *ourstatus = &lp->waitstatus; |
89a5711c | 1940 | int event = linux_ptrace_get_extended_event (status); |
d6b0e80f | 1941 | |
bfd09d20 JS |
1942 | /* All extended events we currently use are mid-syscall. Only |
1943 | PTRACE_EVENT_STOP is delivered more like a signal-stop, but | |
1944 | you have to be using PTRACE_SEIZE to get that. */ | |
1945 | lp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY; | |
1946 | ||
3d799a95 DJ |
1947 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
1948 | || event == PTRACE_EVENT_CLONE) | |
d6b0e80f | 1949 | { |
3d799a95 DJ |
1950 | unsigned long new_pid; |
1951 | int ret; | |
1952 | ||
1953 | ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); | |
6fc19103 | 1954 | |
3d799a95 DJ |
1955 | /* If we haven't already seen the new PID stop, wait for it now. */ |
1956 | if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
1957 | { | |
1958 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
1959 | hits the SIGSTOP, but we're already attached. */ | |
4a6ed09b | 1960 | ret = my_waitpid (new_pid, &status, __WALL); |
3d799a95 DJ |
1961 | if (ret == -1) |
1962 | perror_with_name (_("waiting for new child")); | |
1963 | else if (ret != new_pid) | |
1964 | internal_error (__FILE__, __LINE__, | |
1965 | _("wait returned unexpected PID %d"), ret); | |
1966 | else if (!WIFSTOPPED (status)) | |
1967 | internal_error (__FILE__, __LINE__, | |
1968 | _("wait returned unexpected status 0x%x"), status); | |
1969 | } | |
1970 | ||
fd79271b | 1971 | ourstatus->value.related_pid = ptid_t (new_pid, new_pid, 0); |
3d799a95 | 1972 | |
26cb8b7c PA |
1973 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) |
1974 | { | |
1975 | /* The arch-specific native code may need to know about new | |
1976 | forks even if those end up never mapped to an | |
1977 | inferior. */ | |
135340af | 1978 | linux_target->low_new_fork (lp, new_pid); |
26cb8b7c PA |
1979 | } |
1980 | ||
2277426b | 1981 | if (event == PTRACE_EVENT_FORK |
e99b03dc | 1982 | && linux_fork_checkpointing_p (lp->ptid.pid ())) |
2277426b | 1983 | { |
2277426b PA |
1984 | /* Handle checkpointing by linux-fork.c here as a special |
1985 | case. We don't want the follow-fork-mode or 'catch fork' | |
1986 | to interfere with this. */ | |
1987 | ||
1988 | /* This won't actually modify the breakpoint list, but will | |
1989 | physically remove the breakpoints from the child. */ | |
fd79271b | 1990 | detach_breakpoints (ptid_t (new_pid, new_pid, 0)); |
2277426b PA |
1991 | |
1992 | /* Retain child fork in ptrace (stopped) state. */ | |
14571dad MS |
1993 | if (!find_fork_pid (new_pid)) |
1994 | add_fork (new_pid); | |
2277426b PA |
1995 | |
1996 | /* Report as spurious, so that infrun doesn't want to follow | |
1997 | this fork. We're actually doing an infcall in | |
1998 | linux-fork.c. */ | |
1999 | ourstatus->kind = TARGET_WAITKIND_SPURIOUS; | |
2277426b PA |
2000 | |
2001 | /* Report the stop to the core. */ | |
2002 | return 0; | |
2003 | } | |
2004 | ||
3d799a95 DJ |
2005 | if (event == PTRACE_EVENT_FORK) |
2006 | ourstatus->kind = TARGET_WAITKIND_FORKED; | |
2007 | else if (event == PTRACE_EVENT_VFORK) | |
2008 | ourstatus->kind = TARGET_WAITKIND_VFORKED; | |
4dd63d48 | 2009 | else if (event == PTRACE_EVENT_CLONE) |
3d799a95 | 2010 | { |
78768c4a JK |
2011 | struct lwp_info *new_lp; |
2012 | ||
3d799a95 | 2013 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
78768c4a | 2014 | |
3c4d7e12 PA |
2015 | if (debug_linux_nat) |
2016 | fprintf_unfiltered (gdb_stdlog, | |
2017 | "LHEW: Got clone event " | |
2018 | "from LWP %d, new child is LWP %ld\n", | |
2019 | pid, new_pid); | |
2020 | ||
e99b03dc | 2021 | new_lp = add_lwp (ptid_t (lp->ptid.pid (), new_pid, 0)); |
4c28f408 | 2022 | new_lp->stopped = 1; |
4dd63d48 | 2023 | new_lp->resumed = 1; |
d6b0e80f | 2024 | |
2db9a427 PA |
2025 | /* If the thread_db layer is active, let it record the user |
2026 | level thread id and status, and add the thread to GDB's | |
2027 | list. */ | |
2028 | if (!thread_db_notice_clone (lp->ptid, new_lp->ptid)) | |
3d799a95 | 2029 | { |
2db9a427 PA |
2030 | /* The process is not using thread_db. Add the LWP to |
2031 | GDB's list. */ | |
e38504b3 | 2032 | target_post_attach (new_lp->ptid.lwp ()); |
5b6d1e4f | 2033 | add_thread (linux_target, new_lp->ptid); |
2db9a427 | 2034 | } |
4c28f408 | 2035 | |
2ee52aa4 | 2036 | /* Even if we're stopping the thread for some reason |
4dd63d48 PA |
2037 | internal to this module, from the perspective of infrun |
2038 | and the user/frontend, this new thread is running until | |
2039 | it next reports a stop. */ | |
5b6d1e4f PA |
2040 | set_running (linux_target, new_lp->ptid, 1); |
2041 | set_executing (linux_target, new_lp->ptid, 1); | |
4c28f408 | 2042 | |
4dd63d48 | 2043 | if (WSTOPSIG (status) != SIGSTOP) |
79395f92 | 2044 | { |
4dd63d48 PA |
2045 | /* This can happen if someone starts sending signals to |
2046 | the new thread before it gets a chance to run, which | |
2047 | have a lower number than SIGSTOP (e.g. SIGUSR1). | |
2048 | This is an unlikely case, and harder to handle for | |
2049 | fork / vfork than for clone, so we do not try - but | |
2050 | we handle it for clone events here. */ | |
2051 | ||
2052 | new_lp->signalled = 1; | |
2053 | ||
79395f92 PA |
2054 | /* We created NEW_LP so it cannot yet contain STATUS. */ |
2055 | gdb_assert (new_lp->status == 0); | |
2056 | ||
2057 | /* Save the wait status to report later. */ | |
2058 | if (debug_linux_nat) | |
2059 | fprintf_unfiltered (gdb_stdlog, | |
2060 | "LHEW: waitpid of new LWP %ld, " | |
2061 | "saving status %s\n", | |
e38504b3 | 2062 | (long) new_lp->ptid.lwp (), |
79395f92 PA |
2063 | status_to_str (status)); |
2064 | new_lp->status = status; | |
2065 | } | |
aa01bd36 PA |
2066 | else if (report_thread_events) |
2067 | { | |
2068 | new_lp->waitstatus.kind = TARGET_WAITKIND_THREAD_CREATED; | |
2069 | new_lp->status = status; | |
2070 | } | |
79395f92 | 2071 | |
3d799a95 DJ |
2072 | return 1; |
2073 | } | |
2074 | ||
2075 | return 0; | |
d6b0e80f AC |
2076 | } |
2077 | ||
3d799a95 DJ |
2078 | if (event == PTRACE_EVENT_EXEC) |
2079 | { | |
a75724bc PA |
2080 | if (debug_linux_nat) |
2081 | fprintf_unfiltered (gdb_stdlog, | |
2082 | "LHEW: Got exec event from LWP %ld\n", | |
e38504b3 | 2083 | lp->ptid.lwp ()); |
a75724bc | 2084 | |
3d799a95 DJ |
2085 | ourstatus->kind = TARGET_WAITKIND_EXECD; |
2086 | ourstatus->value.execd_pathname | |
f6ac5f3d | 2087 | = xstrdup (linux_proc_pid_to_exec_file (pid)); |
3d799a95 | 2088 | |
8af756ef PA |
2089 | /* The thread that execed must have been resumed, but, when a |
2090 | thread execs, it changes its tid to the tgid, and the old | |
2091 | tgid thread might have not been resumed. */ | |
2092 | lp->resumed = 1; | |
6c95b8df PA |
2093 | return 0; |
2094 | } | |
2095 | ||
2096 | if (event == PTRACE_EVENT_VFORK_DONE) | |
2097 | { | |
2098 | if (current_inferior ()->waiting_for_vfork_done) | |
3d799a95 | 2099 | { |
6c95b8df | 2100 | if (debug_linux_nat) |
3e43a32a MS |
2101 | fprintf_unfiltered (gdb_stdlog, |
2102 | "LHEW: Got expected PTRACE_EVENT_" | |
2103 | "VFORK_DONE from LWP %ld: stopping\n", | |
e38504b3 | 2104 | lp->ptid.lwp ()); |
3d799a95 | 2105 | |
6c95b8df PA |
2106 | ourstatus->kind = TARGET_WAITKIND_VFORK_DONE; |
2107 | return 0; | |
3d799a95 DJ |
2108 | } |
2109 | ||
6c95b8df | 2110 | if (debug_linux_nat) |
3e43a32a MS |
2111 | fprintf_unfiltered (gdb_stdlog, |
2112 | "LHEW: Got PTRACE_EVENT_VFORK_DONE " | |
20ba1ce6 | 2113 | "from LWP %ld: ignoring\n", |
e38504b3 | 2114 | lp->ptid.lwp ()); |
6c95b8df | 2115 | return 1; |
3d799a95 DJ |
2116 | } |
2117 | ||
2118 | internal_error (__FILE__, __LINE__, | |
2119 | _("unknown ptrace event %d"), event); | |
d6b0e80f AC |
2120 | } |
2121 | ||
9c3a5d93 PA |
2122 | /* Suspend waiting for a signal. We're mostly interested in |
2123 | SIGCHLD/SIGINT. */ | |
2124 | ||
2125 | static void | |
2126 | wait_for_signal () | |
2127 | { | |
2128 | if (debug_linux_nat) | |
2129 | fprintf_unfiltered (gdb_stdlog, "linux-nat: about to sigsuspend\n"); | |
2130 | sigsuspend (&suspend_mask); | |
2131 | ||
2132 | /* If the quit flag is set, it means that the user pressed Ctrl-C | |
2133 | and we're debugging a process that is running on a separate | |
2134 | terminal, so we must forward the Ctrl-C to the inferior. (If the | |
2135 | inferior is sharing GDB's terminal, then the Ctrl-C reaches the | |
2136 | inferior directly.) We must do this here because functions that | |
2137 | need to block waiting for a signal loop forever until there's an | |
2138 | event to report before returning back to the event loop. */ | |
2139 | if (!target_terminal::is_ours ()) | |
2140 | { | |
2141 | if (check_quit_flag ()) | |
2142 | target_pass_ctrlc (); | |
2143 | } | |
2144 | } | |
2145 | ||
d6b0e80f AC |
2146 | /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has |
2147 | exited. */ | |
2148 | ||
2149 | static int | |
2150 | wait_lwp (struct lwp_info *lp) | |
2151 | { | |
2152 | pid_t pid; | |
432b4d03 | 2153 | int status = 0; |
d6b0e80f | 2154 | int thread_dead = 0; |
432b4d03 | 2155 | sigset_t prev_mask; |
d6b0e80f AC |
2156 | |
2157 | gdb_assert (!lp->stopped); | |
2158 | gdb_assert (lp->status == 0); | |
2159 | ||
432b4d03 JK |
2160 | /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
2161 | block_child_signals (&prev_mask); | |
2162 | ||
2163 | for (;;) | |
d6b0e80f | 2164 | { |
e38504b3 | 2165 | pid = my_waitpid (lp->ptid.lwp (), &status, __WALL | WNOHANG); |
a9f4bb21 PA |
2166 | if (pid == -1 && errno == ECHILD) |
2167 | { | |
2168 | /* The thread has previously exited. We need to delete it | |
4a6ed09b PA |
2169 | now because if this was a non-leader thread execing, we |
2170 | won't get an exit event. See comments on exec events at | |
2171 | the top of the file. */ | |
a9f4bb21 PA |
2172 | thread_dead = 1; |
2173 | if (debug_linux_nat) | |
2174 | fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n", | |
a068643d | 2175 | target_pid_to_str (lp->ptid).c_str ()); |
a9f4bb21 | 2176 | } |
432b4d03 JK |
2177 | if (pid != 0) |
2178 | break; | |
2179 | ||
2180 | /* Bugs 10970, 12702. | |
2181 | Thread group leader may have exited in which case we'll lock up in | |
2182 | waitpid if there are other threads, even if they are all zombies too. | |
2183 | Basically, we're not supposed to use waitpid this way. | |
4a6ed09b PA |
2184 | tkill(pid,0) cannot be used here as it gets ESRCH for both |
2185 | for zombie and running processes. | |
432b4d03 JK |
2186 | |
2187 | As a workaround, check if we're waiting for the thread group leader and | |
2188 | if it's a zombie, and avoid calling waitpid if it is. | |
2189 | ||
2190 | This is racy, what if the tgl becomes a zombie right after we check? | |
2191 | Therefore always use WNOHANG with sigsuspend - it is equivalent to | |
5f572dec | 2192 | waiting waitpid but linux_proc_pid_is_zombie is safe this way. */ |
432b4d03 | 2193 | |
e38504b3 TT |
2194 | if (lp->ptid.pid () == lp->ptid.lwp () |
2195 | && linux_proc_pid_is_zombie (lp->ptid.lwp ())) | |
d6b0e80f | 2196 | { |
d6b0e80f AC |
2197 | thread_dead = 1; |
2198 | if (debug_linux_nat) | |
432b4d03 JK |
2199 | fprintf_unfiltered (gdb_stdlog, |
2200 | "WL: Thread group leader %s vanished.\n", | |
a068643d | 2201 | target_pid_to_str (lp->ptid).c_str ()); |
432b4d03 | 2202 | break; |
d6b0e80f | 2203 | } |
432b4d03 JK |
2204 | |
2205 | /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers | |
2206 | get invoked despite our caller had them intentionally blocked by | |
2207 | block_child_signals. This is sensitive only to the loop of | |
2208 | linux_nat_wait_1 and there if we get called my_waitpid gets called | |
2209 | again before it gets to sigsuspend so we can safely let the handlers | |
2210 | get executed here. */ | |
9c3a5d93 | 2211 | wait_for_signal (); |
432b4d03 JK |
2212 | } |
2213 | ||
2214 | restore_child_signals_mask (&prev_mask); | |
2215 | ||
d6b0e80f AC |
2216 | if (!thread_dead) |
2217 | { | |
e38504b3 | 2218 | gdb_assert (pid == lp->ptid.lwp ()); |
d6b0e80f AC |
2219 | |
2220 | if (debug_linux_nat) | |
2221 | { | |
2222 | fprintf_unfiltered (gdb_stdlog, | |
2223 | "WL: waitpid %s received %s\n", | |
a068643d | 2224 | target_pid_to_str (lp->ptid).c_str (), |
d6b0e80f AC |
2225 | status_to_str (status)); |
2226 | } | |
d6b0e80f | 2227 | |
a9f4bb21 PA |
2228 | /* Check if the thread has exited. */ |
2229 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
2230 | { | |
aa01bd36 | 2231 | if (report_thread_events |
e38504b3 | 2232 | || lp->ptid.pid () == lp->ptid.lwp ()) |
69dde7dc PA |
2233 | { |
2234 | if (debug_linux_nat) | |
aa01bd36 | 2235 | fprintf_unfiltered (gdb_stdlog, "WL: LWP %d exited.\n", |
e99b03dc | 2236 | lp->ptid.pid ()); |
69dde7dc | 2237 | |
aa01bd36 | 2238 | /* If this is the leader exiting, it means the whole |
69dde7dc PA |
2239 | process is gone. Store the status to report to the |
2240 | core. Store it in lp->waitstatus, because lp->status | |
2241 | would be ambiguous (W_EXITCODE(0,0) == 0). */ | |
2242 | store_waitstatus (&lp->waitstatus, status); | |
2243 | return 0; | |
2244 | } | |
2245 | ||
a9f4bb21 PA |
2246 | thread_dead = 1; |
2247 | if (debug_linux_nat) | |
2248 | fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n", | |
a068643d | 2249 | target_pid_to_str (lp->ptid).c_str ()); |
a9f4bb21 | 2250 | } |
d6b0e80f AC |
2251 | } |
2252 | ||
2253 | if (thread_dead) | |
2254 | { | |
e26af52f | 2255 | exit_lwp (lp); |
d6b0e80f AC |
2256 | return 0; |
2257 | } | |
2258 | ||
2259 | gdb_assert (WIFSTOPPED (status)); | |
8817a6f2 | 2260 | lp->stopped = 1; |
d6b0e80f | 2261 | |
8784d563 PA |
2262 | if (lp->must_set_ptrace_flags) |
2263 | { | |
5b6d1e4f | 2264 | inferior *inf = find_inferior_pid (linux_target, lp->ptid.pid ()); |
de0d863e | 2265 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 2266 | |
e38504b3 | 2267 | linux_enable_event_reporting (lp->ptid.lwp (), options); |
8784d563 PA |
2268 | lp->must_set_ptrace_flags = 0; |
2269 | } | |
2270 | ||
ca2163eb PA |
2271 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2272 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2273 | { | |
2274 | /* No longer need the sysgood bit. The ptrace event ends up | |
2275 | recorded in lp->waitstatus if we care for it. We can carry | |
2276 | on handling the event like a regular SIGTRAP from here | |
2277 | on. */ | |
2278 | status = W_STOPCODE (SIGTRAP); | |
2279 | if (linux_handle_syscall_trap (lp, 1)) | |
2280 | return wait_lwp (lp); | |
2281 | } | |
bfd09d20 JS |
2282 | else |
2283 | { | |
2284 | /* Almost all other ptrace-stops are known to be outside of system | |
2285 | calls, with further exceptions in linux_handle_extended_wait. */ | |
2286 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2287 | } | |
ca2163eb | 2288 | |
d6b0e80f | 2289 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2290 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2291 | && linux_is_extended_waitstatus (status)) | |
d6b0e80f AC |
2292 | { |
2293 | if (debug_linux_nat) | |
2294 | fprintf_unfiltered (gdb_stdlog, | |
2295 | "WL: Handling extended status 0x%06x\n", | |
2296 | status); | |
4dd63d48 | 2297 | linux_handle_extended_wait (lp, status); |
20ba1ce6 | 2298 | return 0; |
d6b0e80f AC |
2299 | } |
2300 | ||
2301 | return status; | |
2302 | } | |
2303 | ||
2304 | /* Send a SIGSTOP to LP. */ | |
2305 | ||
2306 | static int | |
d3a70e03 | 2307 | stop_callback (struct lwp_info *lp) |
d6b0e80f AC |
2308 | { |
2309 | if (!lp->stopped && !lp->signalled) | |
2310 | { | |
2311 | int ret; | |
2312 | ||
2313 | if (debug_linux_nat) | |
2314 | { | |
2315 | fprintf_unfiltered (gdb_stdlog, | |
2316 | "SC: kill %s **<SIGSTOP>**\n", | |
a068643d | 2317 | target_pid_to_str (lp->ptid).c_str ()); |
d6b0e80f AC |
2318 | } |
2319 | errno = 0; | |
e38504b3 | 2320 | ret = kill_lwp (lp->ptid.lwp (), SIGSTOP); |
d6b0e80f AC |
2321 | if (debug_linux_nat) |
2322 | { | |
2323 | fprintf_unfiltered (gdb_stdlog, | |
2324 | "SC: lwp kill %d %s\n", | |
2325 | ret, | |
2326 | errno ? safe_strerror (errno) : "ERRNO-OK"); | |
2327 | } | |
2328 | ||
2329 | lp->signalled = 1; | |
2330 | gdb_assert (lp->status == 0); | |
2331 | } | |
2332 | ||
2333 | return 0; | |
2334 | } | |
2335 | ||
7b50312a PA |
2336 | /* Request a stop on LWP. */ |
2337 | ||
2338 | void | |
2339 | linux_stop_lwp (struct lwp_info *lwp) | |
2340 | { | |
d3a70e03 | 2341 | stop_callback (lwp); |
7b50312a PA |
2342 | } |
2343 | ||
2db9a427 PA |
2344 | /* See linux-nat.h */ |
2345 | ||
2346 | void | |
2347 | linux_stop_and_wait_all_lwps (void) | |
2348 | { | |
2349 | /* Stop all LWP's ... */ | |
d3a70e03 | 2350 | iterate_over_lwps (minus_one_ptid, stop_callback); |
2db9a427 PA |
2351 | |
2352 | /* ... and wait until all of them have reported back that | |
2353 | they're no longer running. */ | |
d3a70e03 | 2354 | iterate_over_lwps (minus_one_ptid, stop_wait_callback); |
2db9a427 PA |
2355 | } |
2356 | ||
2357 | /* See linux-nat.h */ | |
2358 | ||
2359 | void | |
2360 | linux_unstop_all_lwps (void) | |
2361 | { | |
2362 | iterate_over_lwps (minus_one_ptid, | |
d3a70e03 TT |
2363 | [] (struct lwp_info *info) |
2364 | { | |
2365 | return resume_stopped_resumed_lwps (info, minus_one_ptid); | |
2366 | }); | |
2db9a427 PA |
2367 | } |
2368 | ||
57380f4e | 2369 | /* Return non-zero if LWP PID has a pending SIGINT. */ |
d6b0e80f AC |
2370 | |
2371 | static int | |
57380f4e DJ |
2372 | linux_nat_has_pending_sigint (int pid) |
2373 | { | |
2374 | sigset_t pending, blocked, ignored; | |
57380f4e DJ |
2375 | |
2376 | linux_proc_pending_signals (pid, &pending, &blocked, &ignored); | |
2377 | ||
2378 | if (sigismember (&pending, SIGINT) | |
2379 | && !sigismember (&ignored, SIGINT)) | |
2380 | return 1; | |
2381 | ||
2382 | return 0; | |
2383 | } | |
2384 | ||
2385 | /* Set a flag in LP indicating that we should ignore its next SIGINT. */ | |
2386 | ||
2387 | static int | |
d3a70e03 | 2388 | set_ignore_sigint (struct lwp_info *lp) |
d6b0e80f | 2389 | { |
57380f4e DJ |
2390 | /* If a thread has a pending SIGINT, consume it; otherwise, set a |
2391 | flag to consume the next one. */ | |
2392 | if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) | |
2393 | && WSTOPSIG (lp->status) == SIGINT) | |
2394 | lp->status = 0; | |
2395 | else | |
2396 | lp->ignore_sigint = 1; | |
2397 | ||
2398 | return 0; | |
2399 | } | |
2400 | ||
2401 | /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. | |
2402 | This function is called after we know the LWP has stopped; if the LWP | |
2403 | stopped before the expected SIGINT was delivered, then it will never have | |
2404 | arrived. Also, if the signal was delivered to a shared queue and consumed | |
2405 | by a different thread, it will never be delivered to this LWP. */ | |
d6b0e80f | 2406 | |
57380f4e DJ |
2407 | static void |
2408 | maybe_clear_ignore_sigint (struct lwp_info *lp) | |
2409 | { | |
2410 | if (!lp->ignore_sigint) | |
2411 | return; | |
2412 | ||
e38504b3 | 2413 | if (!linux_nat_has_pending_sigint (lp->ptid.lwp ())) |
57380f4e DJ |
2414 | { |
2415 | if (debug_linux_nat) | |
2416 | fprintf_unfiltered (gdb_stdlog, | |
2417 | "MCIS: Clearing bogus flag for %s\n", | |
a068643d | 2418 | target_pid_to_str (lp->ptid).c_str ()); |
57380f4e DJ |
2419 | lp->ignore_sigint = 0; |
2420 | } | |
2421 | } | |
2422 | ||
ebec9a0f PA |
2423 | /* Fetch the possible triggered data watchpoint info and store it in |
2424 | LP. | |
2425 | ||
2426 | On some archs, like x86, that use debug registers to set | |
2427 | watchpoints, it's possible that the way to know which watched | |
2428 | address trapped, is to check the register that is used to select | |
2429 | which address to watch. Problem is, between setting the watchpoint | |
2430 | and reading back which data address trapped, the user may change | |
2431 | the set of watchpoints, and, as a consequence, GDB changes the | |
2432 | debug registers in the inferior. To avoid reading back a stale | |
2433 | stopped-data-address when that happens, we cache in LP the fact | |
2434 | that a watchpoint trapped, and the corresponding data address, as | |
2435 | soon as we see LP stop with a SIGTRAP. If GDB changes the debug | |
2436 | registers meanwhile, we have the cached data we can rely on. */ | |
2437 | ||
9c02b525 PA |
2438 | static int |
2439 | check_stopped_by_watchpoint (struct lwp_info *lp) | |
ebec9a0f | 2440 | { |
2989a365 | 2441 | scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); |
ebec9a0f PA |
2442 | inferior_ptid = lp->ptid; |
2443 | ||
f6ac5f3d | 2444 | if (linux_target->low_stopped_by_watchpoint ()) |
ebec9a0f | 2445 | { |
15c66dd6 | 2446 | lp->stop_reason = TARGET_STOPPED_BY_WATCHPOINT; |
f6ac5f3d PA |
2447 | lp->stopped_data_address_p |
2448 | = linux_target->low_stopped_data_address (&lp->stopped_data_address); | |
ebec9a0f PA |
2449 | } |
2450 | ||
15c66dd6 | 2451 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
9c02b525 PA |
2452 | } |
2453 | ||
9c02b525 | 2454 | /* Returns true if the LWP had stopped for a watchpoint. */ |
ebec9a0f | 2455 | |
57810aa7 | 2456 | bool |
f6ac5f3d | 2457 | linux_nat_target::stopped_by_watchpoint () |
ebec9a0f PA |
2458 | { |
2459 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2460 | ||
2461 | gdb_assert (lp != NULL); | |
2462 | ||
15c66dd6 | 2463 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
ebec9a0f PA |
2464 | } |
2465 | ||
57810aa7 | 2466 | bool |
f6ac5f3d | 2467 | linux_nat_target::stopped_data_address (CORE_ADDR *addr_p) |
ebec9a0f PA |
2468 | { |
2469 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2470 | ||
2471 | gdb_assert (lp != NULL); | |
2472 | ||
2473 | *addr_p = lp->stopped_data_address; | |
2474 | ||
2475 | return lp->stopped_data_address_p; | |
2476 | } | |
2477 | ||
26ab7092 JK |
2478 | /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
2479 | ||
135340af PA |
2480 | bool |
2481 | linux_nat_target::low_status_is_event (int status) | |
26ab7092 JK |
2482 | { |
2483 | return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; | |
2484 | } | |
2485 | ||
57380f4e DJ |
2486 | /* Wait until LP is stopped. */ |
2487 | ||
2488 | static int | |
d3a70e03 | 2489 | stop_wait_callback (struct lwp_info *lp) |
57380f4e | 2490 | { |
5b6d1e4f | 2491 | inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
6c95b8df PA |
2492 | |
2493 | /* If this is a vfork parent, bail out, it is not going to report | |
2494 | any SIGSTOP until the vfork is done with. */ | |
2495 | if (inf->vfork_child != NULL) | |
2496 | return 0; | |
2497 | ||
d6b0e80f AC |
2498 | if (!lp->stopped) |
2499 | { | |
2500 | int status; | |
2501 | ||
2502 | status = wait_lwp (lp); | |
2503 | if (status == 0) | |
2504 | return 0; | |
2505 | ||
57380f4e DJ |
2506 | if (lp->ignore_sigint && WIFSTOPPED (status) |
2507 | && WSTOPSIG (status) == SIGINT) | |
d6b0e80f | 2508 | { |
57380f4e | 2509 | lp->ignore_sigint = 0; |
d6b0e80f AC |
2510 | |
2511 | errno = 0; | |
e38504b3 | 2512 | ptrace (PTRACE_CONT, lp->ptid.lwp (), 0, 0); |
8817a6f2 | 2513 | lp->stopped = 0; |
d6b0e80f AC |
2514 | if (debug_linux_nat) |
2515 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
2516 | "PTRACE_CONT %s, 0, 0 (%s) " |
2517 | "(discarding SIGINT)\n", | |
a068643d | 2518 | target_pid_to_str (lp->ptid).c_str (), |
d6b0e80f AC |
2519 | errno ? safe_strerror (errno) : "OK"); |
2520 | ||
d3a70e03 | 2521 | return stop_wait_callback (lp); |
d6b0e80f AC |
2522 | } |
2523 | ||
57380f4e DJ |
2524 | maybe_clear_ignore_sigint (lp); |
2525 | ||
d6b0e80f AC |
2526 | if (WSTOPSIG (status) != SIGSTOP) |
2527 | { | |
e5ef252a | 2528 | /* The thread was stopped with a signal other than SIGSTOP. */ |
7feb7d06 | 2529 | |
e5ef252a PA |
2530 | if (debug_linux_nat) |
2531 | fprintf_unfiltered (gdb_stdlog, | |
2532 | "SWC: Pending event %s in %s\n", | |
2533 | status_to_str ((int) status), | |
a068643d | 2534 | target_pid_to_str (lp->ptid).c_str ()); |
e5ef252a PA |
2535 | |
2536 | /* Save the sigtrap event. */ | |
2537 | lp->status = status; | |
e5ef252a | 2538 | gdb_assert (lp->signalled); |
e7ad2f14 | 2539 | save_stop_reason (lp); |
d6b0e80f AC |
2540 | } |
2541 | else | |
2542 | { | |
7010835a | 2543 | /* We caught the SIGSTOP that we intended to catch. */ |
e5ef252a PA |
2544 | |
2545 | if (debug_linux_nat) | |
2546 | fprintf_unfiltered (gdb_stdlog, | |
2bf6fb9d | 2547 | "SWC: Expected SIGSTOP caught for %s.\n", |
a068643d | 2548 | target_pid_to_str (lp->ptid).c_str ()); |
e5ef252a | 2549 | |
d6b0e80f | 2550 | lp->signalled = 0; |
7010835a AB |
2551 | |
2552 | /* If we are waiting for this stop so we can report the thread | |
2553 | stopped then we need to record this status. Otherwise, we can | |
2554 | now discard this stop event. */ | |
2555 | if (lp->last_resume_kind == resume_stop) | |
2556 | { | |
2557 | lp->status = status; | |
2558 | save_stop_reason (lp); | |
2559 | } | |
d6b0e80f AC |
2560 | } |
2561 | } | |
2562 | ||
2563 | return 0; | |
2564 | } | |
2565 | ||
9c02b525 PA |
2566 | /* Return non-zero if LP has a wait status pending. Discard the |
2567 | pending event and resume the LWP if the event that originally | |
2568 | caused the stop became uninteresting. */ | |
d6b0e80f AC |
2569 | |
2570 | static int | |
d3a70e03 | 2571 | status_callback (struct lwp_info *lp) |
d6b0e80f AC |
2572 | { |
2573 | /* Only report a pending wait status if we pretend that this has | |
2574 | indeed been resumed. */ | |
ca2163eb PA |
2575 | if (!lp->resumed) |
2576 | return 0; | |
2577 | ||
eb54c8bf PA |
2578 | if (!lwp_status_pending_p (lp)) |
2579 | return 0; | |
2580 | ||
15c66dd6 PA |
2581 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
2582 | || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) | |
9c02b525 | 2583 | { |
5b6d1e4f | 2584 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
9c02b525 PA |
2585 | CORE_ADDR pc; |
2586 | int discard = 0; | |
2587 | ||
9c02b525 PA |
2588 | pc = regcache_read_pc (regcache); |
2589 | ||
2590 | if (pc != lp->stop_pc) | |
2591 | { | |
2592 | if (debug_linux_nat) | |
2593 | fprintf_unfiltered (gdb_stdlog, | |
2594 | "SC: PC of %s changed. was=%s, now=%s\n", | |
a068643d | 2595 | target_pid_to_str (lp->ptid).c_str (), |
9c02b525 PA |
2596 | paddress (target_gdbarch (), lp->stop_pc), |
2597 | paddress (target_gdbarch (), pc)); | |
2598 | discard = 1; | |
2599 | } | |
faf09f01 PA |
2600 | |
2601 | #if !USE_SIGTRAP_SIGINFO | |
a01bda52 | 2602 | else if (!breakpoint_inserted_here_p (regcache->aspace (), pc)) |
9c02b525 PA |
2603 | { |
2604 | if (debug_linux_nat) | |
2605 | fprintf_unfiltered (gdb_stdlog, | |
2606 | "SC: previous breakpoint of %s, at %s gone\n", | |
a068643d | 2607 | target_pid_to_str (lp->ptid).c_str (), |
9c02b525 PA |
2608 | paddress (target_gdbarch (), lp->stop_pc)); |
2609 | ||
2610 | discard = 1; | |
2611 | } | |
faf09f01 | 2612 | #endif |
9c02b525 PA |
2613 | |
2614 | if (discard) | |
2615 | { | |
2616 | if (debug_linux_nat) | |
2617 | fprintf_unfiltered (gdb_stdlog, | |
2618 | "SC: pending event of %s cancelled.\n", | |
a068643d | 2619 | target_pid_to_str (lp->ptid).c_str ()); |
9c02b525 PA |
2620 | |
2621 | lp->status = 0; | |
2622 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); | |
2623 | return 0; | |
2624 | } | |
9c02b525 PA |
2625 | } |
2626 | ||
eb54c8bf | 2627 | return 1; |
d6b0e80f AC |
2628 | } |
2629 | ||
d6b0e80f AC |
2630 | /* Count the LWP's that have had events. */ |
2631 | ||
2632 | static int | |
d3a70e03 | 2633 | count_events_callback (struct lwp_info *lp, int *count) |
d6b0e80f | 2634 | { |
d6b0e80f AC |
2635 | gdb_assert (count != NULL); |
2636 | ||
9c02b525 PA |
2637 | /* Select only resumed LWPs that have an event pending. */ |
2638 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2639 | (*count)++; |
2640 | ||
2641 | return 0; | |
2642 | } | |
2643 | ||
2644 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
2645 | ||
2646 | static int | |
d3a70e03 | 2647 | select_singlestep_lwp_callback (struct lwp_info *lp) |
d6b0e80f | 2648 | { |
25289eb2 PA |
2649 | if (lp->last_resume_kind == resume_step |
2650 | && lp->status != 0) | |
d6b0e80f AC |
2651 | return 1; |
2652 | else | |
2653 | return 0; | |
2654 | } | |
2655 | ||
8a99810d PA |
2656 | /* Returns true if LP has a status pending. */ |
2657 | ||
2658 | static int | |
2659 | lwp_status_pending_p (struct lwp_info *lp) | |
2660 | { | |
2661 | /* We check for lp->waitstatus in addition to lp->status, because we | |
2662 | can have pending process exits recorded in lp->status and | |
2663 | W_EXITCODE(0,0) happens to be 0. */ | |
2664 | return lp->status != 0 || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE; | |
2665 | } | |
2666 | ||
b90fc188 | 2667 | /* Select the Nth LWP that has had an event. */ |
d6b0e80f AC |
2668 | |
2669 | static int | |
d3a70e03 | 2670 | select_event_lwp_callback (struct lwp_info *lp, int *selector) |
d6b0e80f | 2671 | { |
d6b0e80f AC |
2672 | gdb_assert (selector != NULL); |
2673 | ||
9c02b525 PA |
2674 | /* Select only resumed LWPs that have an event pending. */ |
2675 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2676 | if ((*selector)-- == 0) |
2677 | return 1; | |
2678 | ||
2679 | return 0; | |
2680 | } | |
2681 | ||
e7ad2f14 PA |
2682 | /* Called when the LWP stopped for a signal/trap. If it stopped for a |
2683 | trap check what caused it (breakpoint, watchpoint, trace, etc.), | |
2684 | and save the result in the LWP's stop_reason field. If it stopped | |
2685 | for a breakpoint, decrement the PC if necessary on the lwp's | |
2686 | architecture. */ | |
9c02b525 | 2687 | |
e7ad2f14 PA |
2688 | static void |
2689 | save_stop_reason (struct lwp_info *lp) | |
710151dd | 2690 | { |
e7ad2f14 PA |
2691 | struct regcache *regcache; |
2692 | struct gdbarch *gdbarch; | |
515630c5 | 2693 | CORE_ADDR pc; |
9c02b525 | 2694 | CORE_ADDR sw_bp_pc; |
faf09f01 PA |
2695 | #if USE_SIGTRAP_SIGINFO |
2696 | siginfo_t siginfo; | |
2697 | #endif | |
9c02b525 | 2698 | |
e7ad2f14 PA |
2699 | gdb_assert (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON); |
2700 | gdb_assert (lp->status != 0); | |
2701 | ||
135340af | 2702 | if (!linux_target->low_status_is_event (lp->status)) |
e7ad2f14 PA |
2703 | return; |
2704 | ||
5b6d1e4f | 2705 | regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 2706 | gdbarch = regcache->arch (); |
e7ad2f14 | 2707 | |
9c02b525 | 2708 | pc = regcache_read_pc (regcache); |
527a273a | 2709 | sw_bp_pc = pc - gdbarch_decr_pc_after_break (gdbarch); |
515630c5 | 2710 | |
faf09f01 PA |
2711 | #if USE_SIGTRAP_SIGINFO |
2712 | if (linux_nat_get_siginfo (lp->ptid, &siginfo)) | |
2713 | { | |
2714 | if (siginfo.si_signo == SIGTRAP) | |
2715 | { | |
e7ad2f14 PA |
2716 | if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code) |
2717 | && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) | |
faf09f01 | 2718 | { |
e7ad2f14 PA |
2719 | /* The si_code is ambiguous on this arch -- check debug |
2720 | registers. */ | |
2721 | if (!check_stopped_by_watchpoint (lp)) | |
2722 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2723 | } | |
2724 | else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)) | |
2725 | { | |
2726 | /* If we determine the LWP stopped for a SW breakpoint, | |
2727 | trust it. Particularly don't check watchpoint | |
2728 | registers, because at least on s390, we'd find | |
2729 | stopped-by-watchpoint as long as there's a watchpoint | |
2730 | set. */ | |
faf09f01 | 2731 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
faf09f01 | 2732 | } |
e7ad2f14 | 2733 | else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) |
faf09f01 | 2734 | { |
e7ad2f14 PA |
2735 | /* This can indicate either a hardware breakpoint or |
2736 | hardware watchpoint. Check debug registers. */ | |
2737 | if (!check_stopped_by_watchpoint (lp)) | |
2738 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; | |
faf09f01 | 2739 | } |
2bf6fb9d PA |
2740 | else if (siginfo.si_code == TRAP_TRACE) |
2741 | { | |
2742 | if (debug_linux_nat) | |
2743 | fprintf_unfiltered (gdb_stdlog, | |
2744 | "CSBB: %s stopped by trace\n", | |
a068643d | 2745 | target_pid_to_str (lp->ptid).c_str ()); |
e7ad2f14 PA |
2746 | |
2747 | /* We may have single stepped an instruction that | |
2748 | triggered a watchpoint. In that case, on some | |
2749 | architectures (such as x86), instead of TRAP_HWBKPT, | |
2750 | si_code indicates TRAP_TRACE, and we need to check | |
2751 | the debug registers separately. */ | |
2752 | check_stopped_by_watchpoint (lp); | |
2bf6fb9d | 2753 | } |
faf09f01 PA |
2754 | } |
2755 | } | |
2756 | #else | |
9c02b525 | 2757 | if ((!lp->step || lp->stop_pc == sw_bp_pc) |
a01bda52 | 2758 | && software_breakpoint_inserted_here_p (regcache->aspace (), |
9c02b525 | 2759 | sw_bp_pc)) |
710151dd | 2760 | { |
9c02b525 PA |
2761 | /* The LWP was either continued, or stepped a software |
2762 | breakpoint instruction. */ | |
e7ad2f14 PA |
2763 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
2764 | } | |
2765 | ||
a01bda52 | 2766 | if (hardware_breakpoint_inserted_here_p (regcache->aspace (), pc)) |
e7ad2f14 PA |
2767 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; |
2768 | ||
2769 | if (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON) | |
2770 | check_stopped_by_watchpoint (lp); | |
2771 | #endif | |
2772 | ||
2773 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT) | |
2774 | { | |
710151dd PA |
2775 | if (debug_linux_nat) |
2776 | fprintf_unfiltered (gdb_stdlog, | |
2bf6fb9d | 2777 | "CSBB: %s stopped by software breakpoint\n", |
a068643d | 2778 | target_pid_to_str (lp->ptid).c_str ()); |
710151dd PA |
2779 | |
2780 | /* Back up the PC if necessary. */ | |
9c02b525 PA |
2781 | if (pc != sw_bp_pc) |
2782 | regcache_write_pc (regcache, sw_bp_pc); | |
515630c5 | 2783 | |
e7ad2f14 PA |
2784 | /* Update this so we record the correct stop PC below. */ |
2785 | pc = sw_bp_pc; | |
710151dd | 2786 | } |
e7ad2f14 | 2787 | else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) |
9c02b525 PA |
2788 | { |
2789 | if (debug_linux_nat) | |
2790 | fprintf_unfiltered (gdb_stdlog, | |
e7ad2f14 | 2791 | "CSBB: %s stopped by hardware breakpoint\n", |
a068643d | 2792 | target_pid_to_str (lp->ptid).c_str ()); |
e7ad2f14 PA |
2793 | } |
2794 | else if (lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT) | |
2795 | { | |
2796 | if (debug_linux_nat) | |
2797 | fprintf_unfiltered (gdb_stdlog, | |
2798 | "CSBB: %s stopped by hardware watchpoint\n", | |
a068643d | 2799 | target_pid_to_str (lp->ptid).c_str ()); |
9c02b525 | 2800 | } |
d6b0e80f | 2801 | |
e7ad2f14 | 2802 | lp->stop_pc = pc; |
d6b0e80f AC |
2803 | } |
2804 | ||
faf09f01 PA |
2805 | |
2806 | /* Returns true if the LWP had stopped for a software breakpoint. */ | |
2807 | ||
57810aa7 | 2808 | bool |
f6ac5f3d | 2809 | linux_nat_target::stopped_by_sw_breakpoint () |
faf09f01 PA |
2810 | { |
2811 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2812 | ||
2813 | gdb_assert (lp != NULL); | |
2814 | ||
2815 | return lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2816 | } | |
2817 | ||
2818 | /* Implement the supports_stopped_by_sw_breakpoint method. */ | |
2819 | ||
57810aa7 | 2820 | bool |
f6ac5f3d | 2821 | linux_nat_target::supports_stopped_by_sw_breakpoint () |
faf09f01 PA |
2822 | { |
2823 | return USE_SIGTRAP_SIGINFO; | |
2824 | } | |
2825 | ||
2826 | /* Returns true if the LWP had stopped for a hardware | |
2827 | breakpoint/watchpoint. */ | |
2828 | ||
57810aa7 | 2829 | bool |
f6ac5f3d | 2830 | linux_nat_target::stopped_by_hw_breakpoint () |
faf09f01 PA |
2831 | { |
2832 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2833 | ||
2834 | gdb_assert (lp != NULL); | |
2835 | ||
2836 | return lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT; | |
2837 | } | |
2838 | ||
2839 | /* Implement the supports_stopped_by_hw_breakpoint method. */ | |
2840 | ||
57810aa7 | 2841 | bool |
f6ac5f3d | 2842 | linux_nat_target::supports_stopped_by_hw_breakpoint () |
faf09f01 PA |
2843 | { |
2844 | return USE_SIGTRAP_SIGINFO; | |
2845 | } | |
2846 | ||
d6b0e80f AC |
2847 | /* Select one LWP out of those that have events pending. */ |
2848 | ||
2849 | static void | |
d90e17a7 | 2850 | select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
d6b0e80f AC |
2851 | { |
2852 | int num_events = 0; | |
2853 | int random_selector; | |
9c02b525 | 2854 | struct lwp_info *event_lp = NULL; |
d6b0e80f | 2855 | |
ac264b3b | 2856 | /* Record the wait status for the original LWP. */ |
d6b0e80f AC |
2857 | (*orig_lp)->status = *status; |
2858 | ||
9c02b525 PA |
2859 | /* In all-stop, give preference to the LWP that is being |
2860 | single-stepped. There will be at most one, and it will be the | |
2861 | LWP that the core is most interested in. If we didn't do this, | |
2862 | then we'd have to handle pending step SIGTRAPs somehow in case | |
2863 | the core later continues the previously-stepped thread, as | |
2864 | otherwise we'd report the pending SIGTRAP then, and the core, not | |
2865 | having stepped the thread, wouldn't understand what the trap was | |
2866 | for, and therefore would report it to the user as a random | |
2867 | signal. */ | |
fbea99ea | 2868 | if (!target_is_non_stop_p ()) |
d6b0e80f | 2869 | { |
d3a70e03 | 2870 | event_lp = iterate_over_lwps (filter, select_singlestep_lwp_callback); |
9c02b525 PA |
2871 | if (event_lp != NULL) |
2872 | { | |
2873 | if (debug_linux_nat) | |
2874 | fprintf_unfiltered (gdb_stdlog, | |
2875 | "SEL: Select single-step %s\n", | |
a068643d | 2876 | target_pid_to_str (event_lp->ptid).c_str ()); |
9c02b525 | 2877 | } |
d6b0e80f | 2878 | } |
9c02b525 PA |
2879 | |
2880 | if (event_lp == NULL) | |
d6b0e80f | 2881 | { |
9c02b525 | 2882 | /* Pick one at random, out of those which have had events. */ |
d6b0e80f | 2883 | |
9c02b525 | 2884 | /* First see how many events we have. */ |
d3a70e03 TT |
2885 | iterate_over_lwps (filter, |
2886 | [&] (struct lwp_info *info) | |
2887 | { | |
2888 | return count_events_callback (info, &num_events); | |
2889 | }); | |
8bf3b159 | 2890 | gdb_assert (num_events > 0); |
d6b0e80f | 2891 | |
9c02b525 PA |
2892 | /* Now randomly pick a LWP out of those that have had |
2893 | events. */ | |
d6b0e80f AC |
2894 | random_selector = (int) |
2895 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
2896 | ||
2897 | if (debug_linux_nat && num_events > 1) | |
2898 | fprintf_unfiltered (gdb_stdlog, | |
9c02b525 | 2899 | "SEL: Found %d events, selecting #%d\n", |
d6b0e80f AC |
2900 | num_events, random_selector); |
2901 | ||
d3a70e03 TT |
2902 | event_lp |
2903 | = (iterate_over_lwps | |
2904 | (filter, | |
2905 | [&] (struct lwp_info *info) | |
2906 | { | |
2907 | return select_event_lwp_callback (info, | |
2908 | &random_selector); | |
2909 | })); | |
d6b0e80f AC |
2910 | } |
2911 | ||
2912 | if (event_lp != NULL) | |
2913 | { | |
2914 | /* Switch the event LWP. */ | |
2915 | *orig_lp = event_lp; | |
2916 | *status = event_lp->status; | |
2917 | } | |
2918 | ||
2919 | /* Flush the wait status for the event LWP. */ | |
2920 | (*orig_lp)->status = 0; | |
2921 | } | |
2922 | ||
2923 | /* Return non-zero if LP has been resumed. */ | |
2924 | ||
2925 | static int | |
d3a70e03 | 2926 | resumed_callback (struct lwp_info *lp) |
d6b0e80f AC |
2927 | { |
2928 | return lp->resumed; | |
2929 | } | |
2930 | ||
02f3fc28 | 2931 | /* Check if we should go on and pass this event to common code. |
9c02b525 | 2932 | Return the affected lwp if we are, or NULL otherwise. */ |
12d9289a | 2933 | |
02f3fc28 | 2934 | static struct lwp_info * |
9c02b525 | 2935 | linux_nat_filter_event (int lwpid, int status) |
02f3fc28 PA |
2936 | { |
2937 | struct lwp_info *lp; | |
89a5711c | 2938 | int event = linux_ptrace_get_extended_event (status); |
02f3fc28 | 2939 | |
f2907e49 | 2940 | lp = find_lwp_pid (ptid_t (lwpid)); |
02f3fc28 PA |
2941 | |
2942 | /* Check for stop events reported by a process we didn't already | |
2943 | know about - anything not already in our LWP list. | |
2944 | ||
2945 | If we're expecting to receive stopped processes after | |
2946 | fork, vfork, and clone events, then we'll just add the | |
2947 | new one to our list and go back to waiting for the event | |
2948 | to be reported - the stopped process might be returned | |
0e5bf2a8 PA |
2949 | from waitpid before or after the event is. |
2950 | ||
2951 | But note the case of a non-leader thread exec'ing after the | |
2952 | leader having exited, and gone from our lists. The non-leader | |
2953 | thread changes its tid to the tgid. */ | |
2954 | ||
2955 | if (WIFSTOPPED (status) && lp == NULL | |
89a5711c | 2956 | && (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC)) |
0e5bf2a8 PA |
2957 | { |
2958 | /* A multi-thread exec after we had seen the leader exiting. */ | |
2959 | if (debug_linux_nat) | |
2960 | fprintf_unfiltered (gdb_stdlog, | |
2961 | "LLW: Re-adding thread group leader LWP %d.\n", | |
2962 | lwpid); | |
2963 | ||
fd79271b | 2964 | lp = add_lwp (ptid_t (lwpid, lwpid, 0)); |
0e5bf2a8 PA |
2965 | lp->stopped = 1; |
2966 | lp->resumed = 1; | |
5b6d1e4f | 2967 | add_thread (linux_target, lp->ptid); |
0e5bf2a8 PA |
2968 | } |
2969 | ||
02f3fc28 PA |
2970 | if (WIFSTOPPED (status) && !lp) |
2971 | { | |
3b27ef47 PA |
2972 | if (debug_linux_nat) |
2973 | fprintf_unfiltered (gdb_stdlog, | |
2974 | "LHEW: saving LWP %ld status %s in stopped_pids list\n", | |
2975 | (long) lwpid, status_to_str (status)); | |
84636d28 | 2976 | add_to_pid_list (&stopped_pids, lwpid, status); |
02f3fc28 PA |
2977 | return NULL; |
2978 | } | |
2979 | ||
2980 | /* Make sure we don't report an event for the exit of an LWP not in | |
1777feb0 | 2981 | our list, i.e. not part of the current process. This can happen |
fd62cb89 | 2982 | if we detach from a program we originally forked and then it |
02f3fc28 PA |
2983 | exits. */ |
2984 | if (!WIFSTOPPED (status) && !lp) | |
2985 | return NULL; | |
2986 | ||
8817a6f2 PA |
2987 | /* This LWP is stopped now. (And if dead, this prevents it from |
2988 | ever being continued.) */ | |
2989 | lp->stopped = 1; | |
2990 | ||
8784d563 PA |
2991 | if (WIFSTOPPED (status) && lp->must_set_ptrace_flags) |
2992 | { | |
5b6d1e4f | 2993 | inferior *inf = find_inferior_pid (linux_target, lp->ptid.pid ()); |
de0d863e | 2994 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 2995 | |
e38504b3 | 2996 | linux_enable_event_reporting (lp->ptid.lwp (), options); |
8784d563 PA |
2997 | lp->must_set_ptrace_flags = 0; |
2998 | } | |
2999 | ||
ca2163eb PA |
3000 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
3001 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
3002 | { | |
3003 | /* No longer need the sysgood bit. The ptrace event ends up | |
3004 | recorded in lp->waitstatus if we care for it. We can carry | |
3005 | on handling the event like a regular SIGTRAP from here | |
3006 | on. */ | |
3007 | status = W_STOPCODE (SIGTRAP); | |
3008 | if (linux_handle_syscall_trap (lp, 0)) | |
3009 | return NULL; | |
3010 | } | |
bfd09d20 JS |
3011 | else |
3012 | { | |
3013 | /* Almost all other ptrace-stops are known to be outside of system | |
3014 | calls, with further exceptions in linux_handle_extended_wait. */ | |
3015 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
3016 | } | |
02f3fc28 | 3017 | |
ca2163eb | 3018 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
3019 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
3020 | && linux_is_extended_waitstatus (status)) | |
02f3fc28 PA |
3021 | { |
3022 | if (debug_linux_nat) | |
3023 | fprintf_unfiltered (gdb_stdlog, | |
3024 | "LLW: Handling extended status 0x%06x\n", | |
3025 | status); | |
4dd63d48 | 3026 | if (linux_handle_extended_wait (lp, status)) |
02f3fc28 PA |
3027 | return NULL; |
3028 | } | |
3029 | ||
3030 | /* Check if the thread has exited. */ | |
9c02b525 PA |
3031 | if (WIFEXITED (status) || WIFSIGNALED (status)) |
3032 | { | |
aa01bd36 | 3033 | if (!report_thread_events |
e99b03dc | 3034 | && num_lwps (lp->ptid.pid ()) > 1) |
02f3fc28 | 3035 | { |
9c02b525 PA |
3036 | if (debug_linux_nat) |
3037 | fprintf_unfiltered (gdb_stdlog, | |
3038 | "LLW: %s exited.\n", | |
a068643d | 3039 | target_pid_to_str (lp->ptid).c_str ()); |
9c02b525 | 3040 | |
4a6ed09b PA |
3041 | /* If there is at least one more LWP, then the exit signal |
3042 | was not the end of the debugged application and should be | |
3043 | ignored. */ | |
3044 | exit_lwp (lp); | |
3045 | return NULL; | |
02f3fc28 PA |
3046 | } |
3047 | ||
77598427 PA |
3048 | /* Note that even if the leader was ptrace-stopped, it can still |
3049 | exit, if e.g., some other thread brings down the whole | |
3050 | process (calls `exit'). So don't assert that the lwp is | |
3051 | resumed. */ | |
02f3fc28 PA |
3052 | if (debug_linux_nat) |
3053 | fprintf_unfiltered (gdb_stdlog, | |
aa01bd36 | 3054 | "LWP %ld exited (resumed=%d)\n", |
e38504b3 | 3055 | lp->ptid.lwp (), lp->resumed); |
02f3fc28 | 3056 | |
9c02b525 PA |
3057 | /* Dead LWP's aren't expected to reported a pending sigstop. */ |
3058 | lp->signalled = 0; | |
3059 | ||
3060 | /* Store the pending event in the waitstatus, because | |
3061 | W_EXITCODE(0,0) == 0. */ | |
3062 | store_waitstatus (&lp->waitstatus, status); | |
3063 | return lp; | |
02f3fc28 PA |
3064 | } |
3065 | ||
02f3fc28 PA |
3066 | /* Make sure we don't report a SIGSTOP that we sent ourselves in |
3067 | an attempt to stop an LWP. */ | |
3068 | if (lp->signalled | |
3069 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) | |
3070 | { | |
02f3fc28 PA |
3071 | lp->signalled = 0; |
3072 | ||
2bf6fb9d | 3073 | if (lp->last_resume_kind == resume_stop) |
25289eb2 | 3074 | { |
2bf6fb9d PA |
3075 | if (debug_linux_nat) |
3076 | fprintf_unfiltered (gdb_stdlog, | |
3077 | "LLW: resume_stop SIGSTOP caught for %s.\n", | |
a068643d | 3078 | target_pid_to_str (lp->ptid).c_str ()); |
2bf6fb9d PA |
3079 | } |
3080 | else | |
3081 | { | |
3082 | /* This is a delayed SIGSTOP. Filter out the event. */ | |
02f3fc28 | 3083 | |
25289eb2 PA |
3084 | if (debug_linux_nat) |
3085 | fprintf_unfiltered (gdb_stdlog, | |
2bf6fb9d | 3086 | "LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n", |
25289eb2 PA |
3087 | lp->step ? |
3088 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
a068643d | 3089 | target_pid_to_str (lp->ptid).c_str ()); |
02f3fc28 | 3090 | |
2bf6fb9d | 3091 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
25289eb2 | 3092 | gdb_assert (lp->resumed); |
25289eb2 PA |
3093 | return NULL; |
3094 | } | |
02f3fc28 PA |
3095 | } |
3096 | ||
57380f4e DJ |
3097 | /* Make sure we don't report a SIGINT that we have already displayed |
3098 | for another thread. */ | |
3099 | if (lp->ignore_sigint | |
3100 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) | |
3101 | { | |
3102 | if (debug_linux_nat) | |
3103 | fprintf_unfiltered (gdb_stdlog, | |
3104 | "LLW: Delayed SIGINT caught for %s.\n", | |
a068643d | 3105 | target_pid_to_str (lp->ptid).c_str ()); |
57380f4e DJ |
3106 | |
3107 | /* This is a delayed SIGINT. */ | |
3108 | lp->ignore_sigint = 0; | |
3109 | ||
8a99810d | 3110 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
57380f4e DJ |
3111 | if (debug_linux_nat) |
3112 | fprintf_unfiltered (gdb_stdlog, | |
3113 | "LLW: %s %s, 0, 0 (discard SIGINT)\n", | |
3114 | lp->step ? | |
3115 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
a068643d | 3116 | target_pid_to_str (lp->ptid).c_str ()); |
57380f4e DJ |
3117 | gdb_assert (lp->resumed); |
3118 | ||
3119 | /* Discard the event. */ | |
3120 | return NULL; | |
3121 | } | |
3122 | ||
9c02b525 PA |
3123 | /* Don't report signals that GDB isn't interested in, such as |
3124 | signals that are neither printed nor stopped upon. Stopping all | |
3125 | threads can be a bit time-consuming so if we want decent | |
3126 | performance with heavily multi-threaded programs, especially when | |
3127 | they're using a high frequency timer, we'd better avoid it if we | |
3128 | can. */ | |
3129 | if (WIFSTOPPED (status)) | |
3130 | { | |
3131 | enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status)); | |
3132 | ||
fbea99ea | 3133 | if (!target_is_non_stop_p ()) |
9c02b525 PA |
3134 | { |
3135 | /* Only do the below in all-stop, as we currently use SIGSTOP | |
3136 | to implement target_stop (see linux_nat_stop) in | |
3137 | non-stop. */ | |
3138 | if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0) | |
3139 | { | |
3140 | /* If ^C/BREAK is typed at the tty/console, SIGINT gets | |
3141 | forwarded to the entire process group, that is, all LWPs | |
3142 | will receive it - unless they're using CLONE_THREAD to | |
3143 | share signals. Since we only want to report it once, we | |
3144 | mark it as ignored for all LWPs except this one. */ | |
d3a70e03 | 3145 | iterate_over_lwps (ptid_t (lp->ptid.pid ()), set_ignore_sigint); |
9c02b525 PA |
3146 | lp->ignore_sigint = 0; |
3147 | } | |
3148 | else | |
3149 | maybe_clear_ignore_sigint (lp); | |
3150 | } | |
3151 | ||
3152 | /* When using hardware single-step, we need to report every signal. | |
c9587f88 | 3153 | Otherwise, signals in pass_mask may be short-circuited |
d8c06f22 AB |
3154 | except signals that might be caused by a breakpoint, or SIGSTOP |
3155 | if we sent the SIGSTOP and are waiting for it to arrive. */ | |
9c02b525 | 3156 | if (!lp->step |
c9587f88 | 3157 | && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status)) |
d8c06f22 | 3158 | && (WSTOPSIG (status) != SIGSTOP |
5b6d1e4f | 3159 | || !find_thread_ptid (linux_target, lp->ptid)->stop_requested) |
c9587f88 | 3160 | && !linux_wstatus_maybe_breakpoint (status)) |
9c02b525 PA |
3161 | { |
3162 | linux_resume_one_lwp (lp, lp->step, signo); | |
3163 | if (debug_linux_nat) | |
3164 | fprintf_unfiltered (gdb_stdlog, | |
3165 | "LLW: %s %s, %s (preempt 'handle')\n", | |
3166 | lp->step ? | |
3167 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
a068643d | 3168 | target_pid_to_str (lp->ptid).c_str (), |
9c02b525 PA |
3169 | (signo != GDB_SIGNAL_0 |
3170 | ? strsignal (gdb_signal_to_host (signo)) | |
3171 | : "0")); | |
3172 | return NULL; | |
3173 | } | |
3174 | } | |
3175 | ||
02f3fc28 PA |
3176 | /* An interesting event. */ |
3177 | gdb_assert (lp); | |
ca2163eb | 3178 | lp->status = status; |
e7ad2f14 | 3179 | save_stop_reason (lp); |
02f3fc28 PA |
3180 | return lp; |
3181 | } | |
3182 | ||
0e5bf2a8 PA |
3183 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
3184 | their exits until all other threads in the group have exited. */ | |
3185 | ||
3186 | static void | |
3187 | check_zombie_leaders (void) | |
3188 | { | |
08036331 | 3189 | for (inferior *inf : all_inferiors ()) |
0e5bf2a8 PA |
3190 | { |
3191 | struct lwp_info *leader_lp; | |
3192 | ||
3193 | if (inf->pid == 0) | |
3194 | continue; | |
3195 | ||
f2907e49 | 3196 | leader_lp = find_lwp_pid (ptid_t (inf->pid)); |
0e5bf2a8 PA |
3197 | if (leader_lp != NULL |
3198 | /* Check if there are other threads in the group, as we may | |
3199 | have raced with the inferior simply exiting. */ | |
3200 | && num_lwps (inf->pid) > 1 | |
5f572dec | 3201 | && linux_proc_pid_is_zombie (inf->pid)) |
0e5bf2a8 PA |
3202 | { |
3203 | if (debug_linux_nat) | |
3204 | fprintf_unfiltered (gdb_stdlog, | |
3205 | "CZL: Thread group leader %d zombie " | |
3206 | "(it exited, or another thread execd).\n", | |
3207 | inf->pid); | |
3208 | ||
3209 | /* A leader zombie can mean one of two things: | |
3210 | ||
3211 | - It exited, and there's an exit status pending | |
3212 | available, or only the leader exited (not the whole | |
3213 | program). In the latter case, we can't waitpid the | |
3214 | leader's exit status until all other threads are gone. | |
3215 | ||
3216 | - There are 3 or more threads in the group, and a thread | |
4a6ed09b PA |
3217 | other than the leader exec'd. See comments on exec |
3218 | events at the top of the file. We could try | |
0e5bf2a8 PA |
3219 | distinguishing the exit and exec cases, by waiting once |
3220 | more, and seeing if something comes out, but it doesn't | |
3221 | sound useful. The previous leader _does_ go away, and | |
3222 | we'll re-add the new one once we see the exec event | |
3223 | (which is just the same as what would happen if the | |
3224 | previous leader did exit voluntarily before some other | |
3225 | thread execs). */ | |
3226 | ||
3227 | if (debug_linux_nat) | |
3228 | fprintf_unfiltered (gdb_stdlog, | |
3229 | "CZL: Thread group leader %d vanished.\n", | |
3230 | inf->pid); | |
3231 | exit_lwp (leader_lp); | |
3232 | } | |
3233 | } | |
3234 | } | |
3235 | ||
aa01bd36 PA |
3236 | /* Convenience function that is called when the kernel reports an exit |
3237 | event. This decides whether to report the event to GDB as a | |
3238 | process exit event, a thread exit event, or to suppress the | |
3239 | event. */ | |
3240 | ||
3241 | static ptid_t | |
3242 | filter_exit_event (struct lwp_info *event_child, | |
3243 | struct target_waitstatus *ourstatus) | |
3244 | { | |
3245 | ptid_t ptid = event_child->ptid; | |
3246 | ||
e99b03dc | 3247 | if (num_lwps (ptid.pid ()) > 1) |
aa01bd36 PA |
3248 | { |
3249 | if (report_thread_events) | |
3250 | ourstatus->kind = TARGET_WAITKIND_THREAD_EXITED; | |
3251 | else | |
3252 | ourstatus->kind = TARGET_WAITKIND_IGNORE; | |
3253 | ||
3254 | exit_lwp (event_child); | |
3255 | } | |
3256 | ||
3257 | return ptid; | |
3258 | } | |
3259 | ||
d6b0e80f | 3260 | static ptid_t |
f6ac5f3d | 3261 | linux_nat_wait_1 (ptid_t ptid, struct target_waitstatus *ourstatus, |
47608cb1 | 3262 | int target_options) |
d6b0e80f | 3263 | { |
fc9b8e47 | 3264 | sigset_t prev_mask; |
4b60df3d | 3265 | enum resume_kind last_resume_kind; |
12d9289a | 3266 | struct lwp_info *lp; |
12d9289a | 3267 | int status; |
d6b0e80f | 3268 | |
01124a23 | 3269 | if (debug_linux_nat) |
b84876c2 PA |
3270 | fprintf_unfiltered (gdb_stdlog, "LLW: enter\n"); |
3271 | ||
f973ed9c DJ |
3272 | /* The first time we get here after starting a new inferior, we may |
3273 | not have added it to the LWP list yet - this is the earliest | |
3274 | moment at which we know its PID. */ | |
0e998d96 | 3275 | if (inferior_ptid.is_pid ()) |
f973ed9c | 3276 | { |
27c9d204 | 3277 | /* Upgrade the main thread's ptid. */ |
5b6d1e4f | 3278 | thread_change_ptid (linux_target, inferior_ptid, |
e99b03dc TT |
3279 | ptid_t (inferior_ptid.pid (), |
3280 | inferior_ptid.pid (), 0)); | |
27c9d204 | 3281 | |
26cb8b7c | 3282 | lp = add_initial_lwp (inferior_ptid); |
f973ed9c DJ |
3283 | lp->resumed = 1; |
3284 | } | |
3285 | ||
12696c10 | 3286 | /* Make sure SIGCHLD is blocked until the sigsuspend below. */ |
7feb7d06 | 3287 | block_child_signals (&prev_mask); |
d6b0e80f | 3288 | |
d6b0e80f | 3289 | /* First check if there is a LWP with a wait status pending. */ |
d3a70e03 | 3290 | lp = iterate_over_lwps (ptid, status_callback); |
8a99810d | 3291 | if (lp != NULL) |
d6b0e80f AC |
3292 | { |
3293 | if (debug_linux_nat) | |
d6b0e80f AC |
3294 | fprintf_unfiltered (gdb_stdlog, |
3295 | "LLW: Using pending wait status %s for %s.\n", | |
ca2163eb | 3296 | status_to_str (lp->status), |
a068643d | 3297 | target_pid_to_str (lp->ptid).c_str ()); |
d6b0e80f AC |
3298 | } |
3299 | ||
9c02b525 PA |
3300 | /* But if we don't find a pending event, we'll have to wait. Always |
3301 | pull all events out of the kernel. We'll randomly select an | |
3302 | event LWP out of all that have events, to prevent starvation. */ | |
7feb7d06 | 3303 | |
d90e17a7 | 3304 | while (lp == NULL) |
d6b0e80f AC |
3305 | { |
3306 | pid_t lwpid; | |
3307 | ||
0e5bf2a8 PA |
3308 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
3309 | quirks: | |
3310 | ||
3311 | - If the thread group leader exits while other threads in the | |
3312 | thread group still exist, waitpid(TGID, ...) hangs. That | |
3313 | waitpid won't return an exit status until the other threads | |
85102364 | 3314 | in the group are reaped. |
0e5bf2a8 PA |
3315 | |
3316 | - When a non-leader thread execs, that thread just vanishes | |
3317 | without reporting an exit (so we'd hang if we waited for it | |
3318 | explicitly in that case). The exec event is reported to | |
3319 | the TGID pid. */ | |
3320 | ||
3321 | errno = 0; | |
4a6ed09b | 3322 | lwpid = my_waitpid (-1, &status, __WALL | WNOHANG); |
0e5bf2a8 PA |
3323 | |
3324 | if (debug_linux_nat) | |
3325 | fprintf_unfiltered (gdb_stdlog, | |
3326 | "LNW: waitpid(-1, ...) returned %d, %s\n", | |
3327 | lwpid, errno ? safe_strerror (errno) : "ERRNO-OK"); | |
b84876c2 | 3328 | |
d6b0e80f AC |
3329 | if (lwpid > 0) |
3330 | { | |
d6b0e80f AC |
3331 | if (debug_linux_nat) |
3332 | { | |
3333 | fprintf_unfiltered (gdb_stdlog, | |
3334 | "LLW: waitpid %ld received %s\n", | |
3335 | (long) lwpid, status_to_str (status)); | |
3336 | } | |
3337 | ||
9c02b525 | 3338 | linux_nat_filter_event (lwpid, status); |
0e5bf2a8 PA |
3339 | /* Retry until nothing comes out of waitpid. A single |
3340 | SIGCHLD can indicate more than one child stopped. */ | |
3341 | continue; | |
d6b0e80f AC |
3342 | } |
3343 | ||
20ba1ce6 PA |
3344 | /* Now that we've pulled all events out of the kernel, resume |
3345 | LWPs that don't have an interesting event to report. */ | |
3346 | iterate_over_lwps (minus_one_ptid, | |
d3a70e03 TT |
3347 | [] (struct lwp_info *info) |
3348 | { | |
3349 | return resume_stopped_resumed_lwps (info, minus_one_ptid); | |
3350 | }); | |
20ba1ce6 PA |
3351 | |
3352 | /* ... and find an LWP with a status to report to the core, if | |
3353 | any. */ | |
d3a70e03 | 3354 | lp = iterate_over_lwps (ptid, status_callback); |
9c02b525 PA |
3355 | if (lp != NULL) |
3356 | break; | |
3357 | ||
0e5bf2a8 PA |
3358 | /* Check for zombie thread group leaders. Those can't be reaped |
3359 | until all other threads in the thread group are. */ | |
3360 | check_zombie_leaders (); | |
d6b0e80f | 3361 | |
0e5bf2a8 PA |
3362 | /* If there are no resumed children left, bail. We'd be stuck |
3363 | forever in the sigsuspend call below otherwise. */ | |
d3a70e03 | 3364 | if (iterate_over_lwps (ptid, resumed_callback) == NULL) |
0e5bf2a8 PA |
3365 | { |
3366 | if (debug_linux_nat) | |
3367 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n"); | |
b84876c2 | 3368 | |
0e5bf2a8 | 3369 | ourstatus->kind = TARGET_WAITKIND_NO_RESUMED; |
b84876c2 | 3370 | |
0e5bf2a8 PA |
3371 | restore_child_signals_mask (&prev_mask); |
3372 | return minus_one_ptid; | |
d6b0e80f | 3373 | } |
28736962 | 3374 | |
0e5bf2a8 PA |
3375 | /* No interesting event to report to the core. */ |
3376 | ||
3377 | if (target_options & TARGET_WNOHANG) | |
3378 | { | |
01124a23 | 3379 | if (debug_linux_nat) |
28736962 PA |
3380 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n"); |
3381 | ||
0e5bf2a8 | 3382 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
28736962 PA |
3383 | restore_child_signals_mask (&prev_mask); |
3384 | return minus_one_ptid; | |
3385 | } | |
d6b0e80f AC |
3386 | |
3387 | /* We shouldn't end up here unless we want to try again. */ | |
d90e17a7 | 3388 | gdb_assert (lp == NULL); |
0e5bf2a8 PA |
3389 | |
3390 | /* Block until we get an event reported with SIGCHLD. */ | |
9c3a5d93 | 3391 | wait_for_signal (); |
d6b0e80f AC |
3392 | } |
3393 | ||
d6b0e80f AC |
3394 | gdb_assert (lp); |
3395 | ||
ca2163eb PA |
3396 | status = lp->status; |
3397 | lp->status = 0; | |
3398 | ||
fbea99ea | 3399 | if (!target_is_non_stop_p ()) |
4c28f408 PA |
3400 | { |
3401 | /* Now stop all other LWP's ... */ | |
d3a70e03 | 3402 | iterate_over_lwps (minus_one_ptid, stop_callback); |
4c28f408 PA |
3403 | |
3404 | /* ... and wait until all of them have reported back that | |
3405 | they're no longer running. */ | |
d3a70e03 | 3406 | iterate_over_lwps (minus_one_ptid, stop_wait_callback); |
9c02b525 PA |
3407 | } |
3408 | ||
3409 | /* If we're not waiting for a specific LWP, choose an event LWP from | |
3410 | among those that have had events. Giving equal priority to all | |
3411 | LWPs that have had events helps prevent starvation. */ | |
d7e15655 | 3412 | if (ptid == minus_one_ptid || ptid.is_pid ()) |
9c02b525 PA |
3413 | select_event_lwp (ptid, &lp, &status); |
3414 | ||
3415 | gdb_assert (lp != NULL); | |
3416 | ||
3417 | /* Now that we've selected our final event LWP, un-adjust its PC if | |
faf09f01 PA |
3418 | it was a software breakpoint, and we can't reliably support the |
3419 | "stopped by software breakpoint" stop reason. */ | |
3420 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT | |
3421 | && !USE_SIGTRAP_SIGINFO) | |
9c02b525 | 3422 | { |
5b6d1e4f | 3423 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 3424 | struct gdbarch *gdbarch = regcache->arch (); |
527a273a | 3425 | int decr_pc = gdbarch_decr_pc_after_break (gdbarch); |
4c28f408 | 3426 | |
9c02b525 PA |
3427 | if (decr_pc != 0) |
3428 | { | |
3429 | CORE_ADDR pc; | |
d6b0e80f | 3430 | |
9c02b525 PA |
3431 | pc = regcache_read_pc (regcache); |
3432 | regcache_write_pc (regcache, pc + decr_pc); | |
3433 | } | |
3434 | } | |
e3e9f5a2 | 3435 | |
9c02b525 PA |
3436 | /* We'll need this to determine whether to report a SIGSTOP as |
3437 | GDB_SIGNAL_0. Need to take a copy because resume_clear_callback | |
3438 | clears it. */ | |
3439 | last_resume_kind = lp->last_resume_kind; | |
4b60df3d | 3440 | |
fbea99ea | 3441 | if (!target_is_non_stop_p ()) |
9c02b525 | 3442 | { |
e3e9f5a2 PA |
3443 | /* In all-stop, from the core's perspective, all LWPs are now |
3444 | stopped until a new resume action is sent over. */ | |
d3a70e03 | 3445 | iterate_over_lwps (minus_one_ptid, resume_clear_callback); |
e3e9f5a2 PA |
3446 | } |
3447 | else | |
25289eb2 | 3448 | { |
d3a70e03 | 3449 | resume_clear_callback (lp); |
25289eb2 | 3450 | } |
d6b0e80f | 3451 | |
135340af | 3452 | if (linux_target->low_status_is_event (status)) |
d6b0e80f | 3453 | { |
d6b0e80f AC |
3454 | if (debug_linux_nat) |
3455 | fprintf_unfiltered (gdb_stdlog, | |
4fdebdd0 | 3456 | "LLW: trap ptid is %s.\n", |
a068643d | 3457 | target_pid_to_str (lp->ptid).c_str ()); |
d6b0e80f | 3458 | } |
d6b0e80f AC |
3459 | |
3460 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
3461 | { | |
3462 | *ourstatus = lp->waitstatus; | |
3463 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
3464 | } | |
3465 | else | |
3466 | store_waitstatus (ourstatus, status); | |
3467 | ||
01124a23 | 3468 | if (debug_linux_nat) |
b84876c2 PA |
3469 | fprintf_unfiltered (gdb_stdlog, "LLW: exit\n"); |
3470 | ||
7feb7d06 | 3471 | restore_child_signals_mask (&prev_mask); |
1e225492 | 3472 | |
4b60df3d | 3473 | if (last_resume_kind == resume_stop |
25289eb2 PA |
3474 | && ourstatus->kind == TARGET_WAITKIND_STOPPED |
3475 | && WSTOPSIG (status) == SIGSTOP) | |
3476 | { | |
3477 | /* A thread that has been requested to stop by GDB with | |
3478 | target_stop, and it stopped cleanly, so report as SIG0. The | |
3479 | use of SIGSTOP is an implementation detail. */ | |
a493e3e2 | 3480 | ourstatus->value.sig = GDB_SIGNAL_0; |
25289eb2 PA |
3481 | } |
3482 | ||
1e225492 JK |
3483 | if (ourstatus->kind == TARGET_WAITKIND_EXITED |
3484 | || ourstatus->kind == TARGET_WAITKIND_SIGNALLED) | |
3485 | lp->core = -1; | |
3486 | else | |
2e794194 | 3487 | lp->core = linux_common_core_of_thread (lp->ptid); |
1e225492 | 3488 | |
aa01bd36 PA |
3489 | if (ourstatus->kind == TARGET_WAITKIND_EXITED) |
3490 | return filter_exit_event (lp, ourstatus); | |
3491 | ||
f973ed9c | 3492 | return lp->ptid; |
d6b0e80f AC |
3493 | } |
3494 | ||
e3e9f5a2 PA |
3495 | /* Resume LWPs that are currently stopped without any pending status |
3496 | to report, but are resumed from the core's perspective. */ | |
3497 | ||
3498 | static int | |
d3a70e03 | 3499 | resume_stopped_resumed_lwps (struct lwp_info *lp, const ptid_t wait_ptid) |
e3e9f5a2 | 3500 | { |
4dd63d48 PA |
3501 | if (!lp->stopped) |
3502 | { | |
3503 | if (debug_linux_nat) | |
3504 | fprintf_unfiltered (gdb_stdlog, | |
3505 | "RSRL: NOT resuming LWP %s, not stopped\n", | |
a068643d | 3506 | target_pid_to_str (lp->ptid).c_str ()); |
4dd63d48 PA |
3507 | } |
3508 | else if (!lp->resumed) | |
3509 | { | |
3510 | if (debug_linux_nat) | |
3511 | fprintf_unfiltered (gdb_stdlog, | |
3512 | "RSRL: NOT resuming LWP %s, not resumed\n", | |
a068643d | 3513 | target_pid_to_str (lp->ptid).c_str ()); |
4dd63d48 PA |
3514 | } |
3515 | else if (lwp_status_pending_p (lp)) | |
3516 | { | |
3517 | if (debug_linux_nat) | |
3518 | fprintf_unfiltered (gdb_stdlog, | |
3519 | "RSRL: NOT resuming LWP %s, has pending status\n", | |
a068643d | 3520 | target_pid_to_str (lp->ptid).c_str ()); |
4dd63d48 PA |
3521 | } |
3522 | else | |
e3e9f5a2 | 3523 | { |
5b6d1e4f | 3524 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 3525 | struct gdbarch *gdbarch = regcache->arch (); |
336060f3 | 3526 | |
a70b8144 | 3527 | try |
e3e9f5a2 | 3528 | { |
23f238d3 PA |
3529 | CORE_ADDR pc = regcache_read_pc (regcache); |
3530 | int leave_stopped = 0; | |
e3e9f5a2 | 3531 | |
23f238d3 PA |
3532 | /* Don't bother if there's a breakpoint at PC that we'd hit |
3533 | immediately, and we're not waiting for this LWP. */ | |
d3a70e03 | 3534 | if (!lp->ptid.matches (wait_ptid)) |
23f238d3 | 3535 | { |
a01bda52 | 3536 | if (breakpoint_inserted_here_p (regcache->aspace (), pc)) |
23f238d3 PA |
3537 | leave_stopped = 1; |
3538 | } | |
e3e9f5a2 | 3539 | |
23f238d3 PA |
3540 | if (!leave_stopped) |
3541 | { | |
3542 | if (debug_linux_nat) | |
3543 | fprintf_unfiltered (gdb_stdlog, | |
3544 | "RSRL: resuming stopped-resumed LWP %s at " | |
3545 | "%s: step=%d\n", | |
a068643d | 3546 | target_pid_to_str (lp->ptid).c_str (), |
23f238d3 PA |
3547 | paddress (gdbarch, pc), |
3548 | lp->step); | |
3549 | ||
3550 | linux_resume_one_lwp_throw (lp, lp->step, GDB_SIGNAL_0); | |
3551 | } | |
3552 | } | |
230d2906 | 3553 | catch (const gdb_exception_error &ex) |
23f238d3 PA |
3554 | { |
3555 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 3556 | throw; |
23f238d3 | 3557 | } |
e3e9f5a2 PA |
3558 | } |
3559 | ||
3560 | return 0; | |
3561 | } | |
3562 | ||
f6ac5f3d PA |
3563 | ptid_t |
3564 | linux_nat_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus, | |
3565 | int target_options) | |
7feb7d06 PA |
3566 | { |
3567 | ptid_t event_ptid; | |
3568 | ||
3569 | if (debug_linux_nat) | |
09826ec5 | 3570 | { |
09ce46f2 | 3571 | std::string options_string = target_options_to_string (target_options); |
09826ec5 PA |
3572 | fprintf_unfiltered (gdb_stdlog, |
3573 | "linux_nat_wait: [%s], [%s]\n", | |
a068643d | 3574 | target_pid_to_str (ptid).c_str (), |
09ce46f2 | 3575 | options_string.c_str ()); |
09826ec5 | 3576 | } |
7feb7d06 PA |
3577 | |
3578 | /* Flush the async file first. */ | |
d9d41e78 | 3579 | if (target_is_async_p ()) |
7feb7d06 PA |
3580 | async_file_flush (); |
3581 | ||
e3e9f5a2 PA |
3582 | /* Resume LWPs that are currently stopped without any pending status |
3583 | to report, but are resumed from the core's perspective. LWPs get | |
3584 | in this state if we find them stopping at a time we're not | |
3585 | interested in reporting the event (target_wait on a | |
3586 | specific_process, for example, see linux_nat_wait_1), and | |
3587 | meanwhile the event became uninteresting. Don't bother resuming | |
3588 | LWPs we're not going to wait for if they'd stop immediately. */ | |
fbea99ea | 3589 | if (target_is_non_stop_p ()) |
d3a70e03 TT |
3590 | iterate_over_lwps (minus_one_ptid, |
3591 | [=] (struct lwp_info *info) | |
3592 | { | |
3593 | return resume_stopped_resumed_lwps (info, ptid); | |
3594 | }); | |
e3e9f5a2 | 3595 | |
f6ac5f3d | 3596 | event_ptid = linux_nat_wait_1 (ptid, ourstatus, target_options); |
7feb7d06 PA |
3597 | |
3598 | /* If we requested any event, and something came out, assume there | |
3599 | may be more. If we requested a specific lwp or process, also | |
3600 | assume there may be more. */ | |
d9d41e78 | 3601 | if (target_is_async_p () |
6953d224 PA |
3602 | && ((ourstatus->kind != TARGET_WAITKIND_IGNORE |
3603 | && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED) | |
d7e15655 | 3604 | || ptid != minus_one_ptid)) |
7feb7d06 PA |
3605 | async_file_mark (); |
3606 | ||
7feb7d06 PA |
3607 | return event_ptid; |
3608 | } | |
3609 | ||
1d2736d4 PA |
3610 | /* Kill one LWP. */ |
3611 | ||
3612 | static void | |
3613 | kill_one_lwp (pid_t pid) | |
d6b0e80f | 3614 | { |
ed731959 JK |
3615 | /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
3616 | ||
3617 | errno = 0; | |
1d2736d4 | 3618 | kill_lwp (pid, SIGKILL); |
ed731959 | 3619 | if (debug_linux_nat) |
57745c90 PA |
3620 | { |
3621 | int save_errno = errno; | |
3622 | ||
3623 | fprintf_unfiltered (gdb_stdlog, | |
1d2736d4 | 3624 | "KC: kill (SIGKILL) %ld, 0, 0 (%s)\n", (long) pid, |
57745c90 PA |
3625 | save_errno ? safe_strerror (save_errno) : "OK"); |
3626 | } | |
ed731959 JK |
3627 | |
3628 | /* Some kernels ignore even SIGKILL for processes under ptrace. */ | |
3629 | ||
d6b0e80f | 3630 | errno = 0; |
1d2736d4 | 3631 | ptrace (PTRACE_KILL, pid, 0, 0); |
d6b0e80f | 3632 | if (debug_linux_nat) |
57745c90 PA |
3633 | { |
3634 | int save_errno = errno; | |
3635 | ||
3636 | fprintf_unfiltered (gdb_stdlog, | |
1d2736d4 | 3637 | "KC: PTRACE_KILL %ld, 0, 0 (%s)\n", (long) pid, |
57745c90 PA |
3638 | save_errno ? safe_strerror (save_errno) : "OK"); |
3639 | } | |
d6b0e80f AC |
3640 | } |
3641 | ||
1d2736d4 PA |
3642 | /* Wait for an LWP to die. */ |
3643 | ||
3644 | static void | |
3645 | kill_wait_one_lwp (pid_t pid) | |
d6b0e80f | 3646 | { |
1d2736d4 | 3647 | pid_t res; |
d6b0e80f AC |
3648 | |
3649 | /* We must make sure that there are no pending events (delayed | |
3650 | SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current | |
3651 | program doesn't interfere with any following debugging session. */ | |
3652 | ||
d6b0e80f AC |
3653 | do |
3654 | { | |
1d2736d4 PA |
3655 | res = my_waitpid (pid, NULL, __WALL); |
3656 | if (res != (pid_t) -1) | |
d6b0e80f | 3657 | { |
e85a822c DJ |
3658 | if (debug_linux_nat) |
3659 | fprintf_unfiltered (gdb_stdlog, | |
1d2736d4 PA |
3660 | "KWC: wait %ld received unknown.\n", |
3661 | (long) pid); | |
4a6ed09b PA |
3662 | /* The Linux kernel sometimes fails to kill a thread |
3663 | completely after PTRACE_KILL; that goes from the stop | |
3664 | point in do_fork out to the one in get_signal_to_deliver | |
3665 | and waits again. So kill it again. */ | |
1d2736d4 | 3666 | kill_one_lwp (pid); |
d6b0e80f AC |
3667 | } |
3668 | } | |
1d2736d4 PA |
3669 | while (res == pid); |
3670 | ||
3671 | gdb_assert (res == -1 && errno == ECHILD); | |
3672 | } | |
3673 | ||
3674 | /* Callback for iterate_over_lwps. */ | |
d6b0e80f | 3675 | |
1d2736d4 | 3676 | static int |
d3a70e03 | 3677 | kill_callback (struct lwp_info *lp) |
1d2736d4 | 3678 | { |
e38504b3 | 3679 | kill_one_lwp (lp->ptid.lwp ()); |
d6b0e80f AC |
3680 | return 0; |
3681 | } | |
3682 | ||
1d2736d4 PA |
3683 | /* Callback for iterate_over_lwps. */ |
3684 | ||
3685 | static int | |
d3a70e03 | 3686 | kill_wait_callback (struct lwp_info *lp) |
1d2736d4 | 3687 | { |
e38504b3 | 3688 | kill_wait_one_lwp (lp->ptid.lwp ()); |
1d2736d4 PA |
3689 | return 0; |
3690 | } | |
3691 | ||
3692 | /* Kill the fork children of any threads of inferior INF that are | |
3693 | stopped at a fork event. */ | |
3694 | ||
3695 | static void | |
3696 | kill_unfollowed_fork_children (struct inferior *inf) | |
3697 | { | |
08036331 PA |
3698 | for (thread_info *thread : inf->non_exited_threads ()) |
3699 | { | |
3700 | struct target_waitstatus *ws = &thread->pending_follow; | |
1d2736d4 | 3701 | |
08036331 PA |
3702 | if (ws->kind == TARGET_WAITKIND_FORKED |
3703 | || ws->kind == TARGET_WAITKIND_VFORKED) | |
3704 | { | |
3705 | ptid_t child_ptid = ws->value.related_pid; | |
3706 | int child_pid = child_ptid.pid (); | |
3707 | int child_lwp = child_ptid.lwp (); | |
3708 | ||
3709 | kill_one_lwp (child_lwp); | |
3710 | kill_wait_one_lwp (child_lwp); | |
3711 | ||
3712 | /* Let the arch-specific native code know this process is | |
3713 | gone. */ | |
3714 | linux_target->low_forget_process (child_pid); | |
3715 | } | |
3716 | } | |
1d2736d4 PA |
3717 | } |
3718 | ||
f6ac5f3d PA |
3719 | void |
3720 | linux_nat_target::kill () | |
d6b0e80f | 3721 | { |
f973ed9c DJ |
3722 | /* If we're stopped while forking and we haven't followed yet, |
3723 | kill the other task. We need to do this first because the | |
3724 | parent will be sleeping if this is a vfork. */ | |
1d2736d4 | 3725 | kill_unfollowed_fork_children (current_inferior ()); |
f973ed9c DJ |
3726 | |
3727 | if (forks_exist_p ()) | |
7feb7d06 | 3728 | linux_fork_killall (); |
f973ed9c DJ |
3729 | else |
3730 | { | |
e99b03dc | 3731 | ptid_t ptid = ptid_t (inferior_ptid.pid ()); |
e0881a8e | 3732 | |
4c28f408 | 3733 | /* Stop all threads before killing them, since ptrace requires |
30baf67b | 3734 | that the thread is stopped to successfully PTRACE_KILL. */ |
d3a70e03 | 3735 | iterate_over_lwps (ptid, stop_callback); |
4c28f408 PA |
3736 | /* ... and wait until all of them have reported back that |
3737 | they're no longer running. */ | |
d3a70e03 | 3738 | iterate_over_lwps (ptid, stop_wait_callback); |
4c28f408 | 3739 | |
f973ed9c | 3740 | /* Kill all LWP's ... */ |
d3a70e03 | 3741 | iterate_over_lwps (ptid, kill_callback); |
f973ed9c DJ |
3742 | |
3743 | /* ... and wait until we've flushed all events. */ | |
d3a70e03 | 3744 | iterate_over_lwps (ptid, kill_wait_callback); |
f973ed9c DJ |
3745 | } |
3746 | ||
bc1e6c81 | 3747 | target_mourn_inferior (inferior_ptid); |
d6b0e80f AC |
3748 | } |
3749 | ||
f6ac5f3d PA |
3750 | void |
3751 | linux_nat_target::mourn_inferior () | |
d6b0e80f | 3752 | { |
e99b03dc | 3753 | int pid = inferior_ptid.pid (); |
26cb8b7c PA |
3754 | |
3755 | purge_lwp_list (pid); | |
d6b0e80f | 3756 | |
f973ed9c | 3757 | if (! forks_exist_p ()) |
d90e17a7 | 3758 | /* Normal case, no other forks available. */ |
f6ac5f3d | 3759 | inf_ptrace_target::mourn_inferior (); |
f973ed9c DJ |
3760 | else |
3761 | /* Multi-fork case. The current inferior_ptid has exited, but | |
3762 | there are other viable forks to debug. Delete the exiting | |
3763 | one and context-switch to the first available. */ | |
3764 | linux_fork_mourn_inferior (); | |
26cb8b7c PA |
3765 | |
3766 | /* Let the arch-specific native code know this process is gone. */ | |
135340af | 3767 | linux_target->low_forget_process (pid); |
d6b0e80f AC |
3768 | } |
3769 | ||
5b009018 PA |
3770 | /* Convert a native/host siginfo object, into/from the siginfo in the |
3771 | layout of the inferiors' architecture. */ | |
3772 | ||
3773 | static void | |
a5362b9a | 3774 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
5b009018 | 3775 | { |
135340af PA |
3776 | /* If the low target didn't do anything, then just do a straight |
3777 | memcpy. */ | |
3778 | if (!linux_target->low_siginfo_fixup (siginfo, inf_siginfo, direction)) | |
5b009018 PA |
3779 | { |
3780 | if (direction == 1) | |
a5362b9a | 3781 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
5b009018 | 3782 | else |
a5362b9a | 3783 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
5b009018 PA |
3784 | } |
3785 | } | |
3786 | ||
9b409511 | 3787 | static enum target_xfer_status |
f6ac5f3d | 3788 | linux_xfer_siginfo (enum target_object object, |
4aa995e1 | 3789 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
3790 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
3791 | ULONGEST *xfered_len) | |
4aa995e1 | 3792 | { |
4aa995e1 | 3793 | int pid; |
a5362b9a TS |
3794 | siginfo_t siginfo; |
3795 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; | |
4aa995e1 PA |
3796 | |
3797 | gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO); | |
3798 | gdb_assert (readbuf || writebuf); | |
3799 | ||
e38504b3 | 3800 | pid = inferior_ptid.lwp (); |
4aa995e1 | 3801 | if (pid == 0) |
e99b03dc | 3802 | pid = inferior_ptid.pid (); |
4aa995e1 PA |
3803 | |
3804 | if (offset > sizeof (siginfo)) | |
2ed4b548 | 3805 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3806 | |
3807 | errno = 0; | |
3808 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3809 | if (errno != 0) | |
2ed4b548 | 3810 | return TARGET_XFER_E_IO; |
4aa995e1 | 3811 | |
5b009018 PA |
3812 | /* When GDB is built as a 64-bit application, ptrace writes into |
3813 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
3814 | inferior with a 64-bit GDB should look the same as debugging it | |
3815 | with a 32-bit GDB, we need to convert it. GDB core always sees | |
3816 | the converted layout, so any read/write will have to be done | |
3817 | post-conversion. */ | |
3818 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
3819 | ||
4aa995e1 PA |
3820 | if (offset + len > sizeof (siginfo)) |
3821 | len = sizeof (siginfo) - offset; | |
3822 | ||
3823 | if (readbuf != NULL) | |
5b009018 | 3824 | memcpy (readbuf, inf_siginfo + offset, len); |
4aa995e1 PA |
3825 | else |
3826 | { | |
5b009018 PA |
3827 | memcpy (inf_siginfo + offset, writebuf, len); |
3828 | ||
3829 | /* Convert back to ptrace layout before flushing it out. */ | |
3830 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
3831 | ||
4aa995e1 PA |
3832 | errno = 0; |
3833 | ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3834 | if (errno != 0) | |
2ed4b548 | 3835 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3836 | } |
3837 | ||
9b409511 YQ |
3838 | *xfered_len = len; |
3839 | return TARGET_XFER_OK; | |
4aa995e1 PA |
3840 | } |
3841 | ||
9b409511 | 3842 | static enum target_xfer_status |
f6ac5f3d PA |
3843 | linux_nat_xfer_osdata (enum target_object object, |
3844 | const char *annex, gdb_byte *readbuf, | |
3845 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, | |
3846 | ULONGEST *xfered_len); | |
3847 | ||
f6ac5f3d PA |
3848 | static enum target_xfer_status |
3849 | linux_proc_xfer_partial (enum target_object object, | |
3850 | const char *annex, gdb_byte *readbuf, | |
3851 | const gdb_byte *writebuf, | |
3852 | ULONGEST offset, LONGEST len, ULONGEST *xfered_len); | |
3853 | ||
3854 | enum target_xfer_status | |
3855 | linux_nat_target::xfer_partial (enum target_object object, | |
3856 | const char *annex, gdb_byte *readbuf, | |
3857 | const gdb_byte *writebuf, | |
3858 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) | |
d6b0e80f | 3859 | { |
9b409511 | 3860 | enum target_xfer_status xfer; |
d6b0e80f | 3861 | |
4aa995e1 | 3862 | if (object == TARGET_OBJECT_SIGNAL_INFO) |
f6ac5f3d | 3863 | return linux_xfer_siginfo (object, annex, readbuf, writebuf, |
9b409511 | 3864 | offset, len, xfered_len); |
4aa995e1 | 3865 | |
c35b1492 PA |
3866 | /* The target is connected but no live inferior is selected. Pass |
3867 | this request down to a lower stratum (e.g., the executable | |
3868 | file). */ | |
d7e15655 | 3869 | if (object == TARGET_OBJECT_MEMORY && inferior_ptid == null_ptid) |
9b409511 | 3870 | return TARGET_XFER_EOF; |
c35b1492 | 3871 | |
f6ac5f3d PA |
3872 | if (object == TARGET_OBJECT_AUXV) |
3873 | return memory_xfer_auxv (this, object, annex, readbuf, writebuf, | |
3874 | offset, len, xfered_len); | |
3875 | ||
3876 | if (object == TARGET_OBJECT_OSDATA) | |
3877 | return linux_nat_xfer_osdata (object, annex, readbuf, writebuf, | |
3878 | offset, len, xfered_len); | |
d6b0e80f | 3879 | |
f6ac5f3d PA |
3880 | /* GDB calculates all addresses in the largest possible address |
3881 | width. | |
3882 | The address width must be masked before its final use - either by | |
3883 | linux_proc_xfer_partial or inf_ptrace_target::xfer_partial. | |
3884 | ||
3885 | Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ | |
3886 | ||
3887 | if (object == TARGET_OBJECT_MEMORY) | |
3888 | { | |
3889 | int addr_bit = gdbarch_addr_bit (target_gdbarch ()); | |
3890 | ||
3891 | if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) | |
3892 | offset &= ((ULONGEST) 1 << addr_bit) - 1; | |
3893 | } | |
3894 | ||
3895 | xfer = linux_proc_xfer_partial (object, annex, readbuf, writebuf, | |
3896 | offset, len, xfered_len); | |
3897 | if (xfer != TARGET_XFER_EOF) | |
3898 | return xfer; | |
3899 | ||
3900 | return inf_ptrace_target::xfer_partial (object, annex, readbuf, writebuf, | |
3901 | offset, len, xfered_len); | |
d6b0e80f AC |
3902 | } |
3903 | ||
57810aa7 | 3904 | bool |
f6ac5f3d | 3905 | linux_nat_target::thread_alive (ptid_t ptid) |
28439f5e | 3906 | { |
4a6ed09b PA |
3907 | /* As long as a PTID is in lwp list, consider it alive. */ |
3908 | return find_lwp_pid (ptid) != NULL; | |
28439f5e PA |
3909 | } |
3910 | ||
8a06aea7 PA |
3911 | /* Implement the to_update_thread_list target method for this |
3912 | target. */ | |
3913 | ||
f6ac5f3d PA |
3914 | void |
3915 | linux_nat_target::update_thread_list () | |
8a06aea7 | 3916 | { |
a6904d5a PA |
3917 | struct lwp_info *lwp; |
3918 | ||
4a6ed09b PA |
3919 | /* We add/delete threads from the list as clone/exit events are |
3920 | processed, so just try deleting exited threads still in the | |
3921 | thread list. */ | |
3922 | delete_exited_threads (); | |
a6904d5a PA |
3923 | |
3924 | /* Update the processor core that each lwp/thread was last seen | |
3925 | running on. */ | |
3926 | ALL_LWPS (lwp) | |
1ad3de98 PA |
3927 | { |
3928 | /* Avoid accessing /proc if the thread hasn't run since we last | |
3929 | time we fetched the thread's core. Accessing /proc becomes | |
3930 | noticeably expensive when we have thousands of LWPs. */ | |
3931 | if (lwp->core == -1) | |
3932 | lwp->core = linux_common_core_of_thread (lwp->ptid); | |
3933 | } | |
8a06aea7 PA |
3934 | } |
3935 | ||
a068643d | 3936 | std::string |
f6ac5f3d | 3937 | linux_nat_target::pid_to_str (ptid_t ptid) |
d6b0e80f | 3938 | { |
15a9e13e | 3939 | if (ptid.lwp_p () |
e38504b3 | 3940 | && (ptid.pid () != ptid.lwp () |
e99b03dc | 3941 | || num_lwps (ptid.pid ()) > 1)) |
a068643d | 3942 | return string_printf ("LWP %ld", ptid.lwp ()); |
d6b0e80f AC |
3943 | |
3944 | return normal_pid_to_str (ptid); | |
3945 | } | |
3946 | ||
f6ac5f3d PA |
3947 | const char * |
3948 | linux_nat_target::thread_name (struct thread_info *thr) | |
4694da01 | 3949 | { |
79efa585 | 3950 | return linux_proc_tid_get_name (thr->ptid); |
4694da01 TT |
3951 | } |
3952 | ||
dba24537 AC |
3953 | /* Accepts an integer PID; Returns a string representing a file that |
3954 | can be opened to get the symbols for the child process. */ | |
3955 | ||
f6ac5f3d PA |
3956 | char * |
3957 | linux_nat_target::pid_to_exec_file (int pid) | |
dba24537 | 3958 | { |
e0d86d2c | 3959 | return linux_proc_pid_to_exec_file (pid); |
dba24537 AC |
3960 | } |
3961 | ||
a379284a AA |
3962 | /* Implement the to_xfer_partial target method using /proc/<pid>/mem. |
3963 | Because we can use a single read/write call, this can be much more | |
3964 | efficient than banging away at PTRACE_PEEKTEXT. */ | |
10d6c8cd | 3965 | |
9b409511 | 3966 | static enum target_xfer_status |
f6ac5f3d | 3967 | linux_proc_xfer_partial (enum target_object object, |
10d6c8cd DJ |
3968 | const char *annex, gdb_byte *readbuf, |
3969 | const gdb_byte *writebuf, | |
9b409511 | 3970 | ULONGEST offset, LONGEST len, ULONGEST *xfered_len) |
dba24537 | 3971 | { |
10d6c8cd DJ |
3972 | LONGEST ret; |
3973 | int fd; | |
dba24537 AC |
3974 | char filename[64]; |
3975 | ||
a379284a | 3976 | if (object != TARGET_OBJECT_MEMORY) |
f486487f | 3977 | return TARGET_XFER_EOF; |
dba24537 AC |
3978 | |
3979 | /* Don't bother for one word. */ | |
3980 | if (len < 3 * sizeof (long)) | |
9b409511 | 3981 | return TARGET_XFER_EOF; |
dba24537 AC |
3982 | |
3983 | /* We could keep this file open and cache it - possibly one per | |
3984 | thread. That requires some juggling, but is even faster. */ | |
b67aeab0 | 3985 | xsnprintf (filename, sizeof filename, "/proc/%ld/mem", |
e38504b3 | 3986 | inferior_ptid.lwp ()); |
a379284a AA |
3987 | fd = gdb_open_cloexec (filename, ((readbuf ? O_RDONLY : O_WRONLY) |
3988 | | O_LARGEFILE), 0); | |
dba24537 | 3989 | if (fd == -1) |
9b409511 | 3990 | return TARGET_XFER_EOF; |
dba24537 | 3991 | |
a379284a AA |
3992 | /* Use pread64/pwrite64 if available, since they save a syscall and can |
3993 | handle 64-bit offsets even on 32-bit platforms (for instance, SPARC | |
3994 | debugging a SPARC64 application). */ | |
dba24537 | 3995 | #ifdef HAVE_PREAD64 |
a379284a AA |
3996 | ret = (readbuf ? pread64 (fd, readbuf, len, offset) |
3997 | : pwrite64 (fd, writebuf, len, offset)); | |
dba24537 | 3998 | #else |
a379284a AA |
3999 | ret = lseek (fd, offset, SEEK_SET); |
4000 | if (ret != -1) | |
4001 | ret = (readbuf ? read (fd, readbuf, len) | |
4002 | : write (fd, writebuf, len)); | |
dba24537 | 4003 | #endif |
dba24537 AC |
4004 | |
4005 | close (fd); | |
9b409511 | 4006 | |
a379284a | 4007 | if (ret == -1 || ret == 0) |
9b409511 YQ |
4008 | return TARGET_XFER_EOF; |
4009 | else | |
4010 | { | |
4011 | *xfered_len = ret; | |
4012 | return TARGET_XFER_OK; | |
4013 | } | |
dba24537 AC |
4014 | } |
4015 | ||
efcbbd14 | 4016 | |
dba24537 AC |
4017 | /* Parse LINE as a signal set and add its set bits to SIGS. */ |
4018 | ||
4019 | static void | |
4020 | add_line_to_sigset (const char *line, sigset_t *sigs) | |
4021 | { | |
4022 | int len = strlen (line) - 1; | |
4023 | const char *p; | |
4024 | int signum; | |
4025 | ||
4026 | if (line[len] != '\n') | |
8a3fe4f8 | 4027 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4028 | |
4029 | p = line; | |
4030 | signum = len * 4; | |
4031 | while (len-- > 0) | |
4032 | { | |
4033 | int digit; | |
4034 | ||
4035 | if (*p >= '0' && *p <= '9') | |
4036 | digit = *p - '0'; | |
4037 | else if (*p >= 'a' && *p <= 'f') | |
4038 | digit = *p - 'a' + 10; | |
4039 | else | |
8a3fe4f8 | 4040 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4041 | |
4042 | signum -= 4; | |
4043 | ||
4044 | if (digit & 1) | |
4045 | sigaddset (sigs, signum + 1); | |
4046 | if (digit & 2) | |
4047 | sigaddset (sigs, signum + 2); | |
4048 | if (digit & 4) | |
4049 | sigaddset (sigs, signum + 3); | |
4050 | if (digit & 8) | |
4051 | sigaddset (sigs, signum + 4); | |
4052 | ||
4053 | p++; | |
4054 | } | |
4055 | } | |
4056 | ||
4057 | /* Find process PID's pending signals from /proc/pid/status and set | |
4058 | SIGS to match. */ | |
4059 | ||
4060 | void | |
3e43a32a MS |
4061 | linux_proc_pending_signals (int pid, sigset_t *pending, |
4062 | sigset_t *blocked, sigset_t *ignored) | |
dba24537 | 4063 | { |
d8d2a3ee | 4064 | char buffer[PATH_MAX], fname[PATH_MAX]; |
dba24537 AC |
4065 | |
4066 | sigemptyset (pending); | |
4067 | sigemptyset (blocked); | |
4068 | sigemptyset (ignored); | |
cde33bf1 | 4069 | xsnprintf (fname, sizeof fname, "/proc/%d/status", pid); |
d419f42d | 4070 | gdb_file_up procfile = gdb_fopen_cloexec (fname, "r"); |
dba24537 | 4071 | if (procfile == NULL) |
8a3fe4f8 | 4072 | error (_("Could not open %s"), fname); |
dba24537 | 4073 | |
d419f42d | 4074 | while (fgets (buffer, PATH_MAX, procfile.get ()) != NULL) |
dba24537 AC |
4075 | { |
4076 | /* Normal queued signals are on the SigPnd line in the status | |
4077 | file. However, 2.6 kernels also have a "shared" pending | |
4078 | queue for delivering signals to a thread group, so check for | |
4079 | a ShdPnd line also. | |
4080 | ||
4081 | Unfortunately some Red Hat kernels include the shared pending | |
4082 | queue but not the ShdPnd status field. */ | |
4083 | ||
61012eef | 4084 | if (startswith (buffer, "SigPnd:\t")) |
dba24537 | 4085 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4086 | else if (startswith (buffer, "ShdPnd:\t")) |
dba24537 | 4087 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4088 | else if (startswith (buffer, "SigBlk:\t")) |
dba24537 | 4089 | add_line_to_sigset (buffer + 8, blocked); |
61012eef | 4090 | else if (startswith (buffer, "SigIgn:\t")) |
dba24537 AC |
4091 | add_line_to_sigset (buffer + 8, ignored); |
4092 | } | |
dba24537 AC |
4093 | } |
4094 | ||
9b409511 | 4095 | static enum target_xfer_status |
f6ac5f3d | 4096 | linux_nat_xfer_osdata (enum target_object object, |
e0881a8e | 4097 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
4098 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
4099 | ULONGEST *xfered_len) | |
07e059b5 | 4100 | { |
07e059b5 VP |
4101 | gdb_assert (object == TARGET_OBJECT_OSDATA); |
4102 | ||
9b409511 YQ |
4103 | *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len); |
4104 | if (*xfered_len == 0) | |
4105 | return TARGET_XFER_EOF; | |
4106 | else | |
4107 | return TARGET_XFER_OK; | |
07e059b5 VP |
4108 | } |
4109 | ||
f6ac5f3d PA |
4110 | std::vector<static_tracepoint_marker> |
4111 | linux_nat_target::static_tracepoint_markers_by_strid (const char *strid) | |
5808517f YQ |
4112 | { |
4113 | char s[IPA_CMD_BUF_SIZE]; | |
e99b03dc | 4114 | int pid = inferior_ptid.pid (); |
5d9310c4 | 4115 | std::vector<static_tracepoint_marker> markers; |
256642e8 | 4116 | const char *p = s; |
fd79271b | 4117 | ptid_t ptid = ptid_t (pid, 0, 0); |
5d9310c4 | 4118 | static_tracepoint_marker marker; |
5808517f YQ |
4119 | |
4120 | /* Pause all */ | |
4121 | target_stop (ptid); | |
4122 | ||
4123 | memcpy (s, "qTfSTM", sizeof ("qTfSTM")); | |
4124 | s[sizeof ("qTfSTM")] = 0; | |
4125 | ||
42476b70 | 4126 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f | 4127 | |
1db93f14 TT |
4128 | /* Unpause all. */ |
4129 | SCOPE_EXIT { target_continue_no_signal (ptid); }; | |
5808517f YQ |
4130 | |
4131 | while (*p++ == 'm') | |
4132 | { | |
5808517f YQ |
4133 | do |
4134 | { | |
5d9310c4 | 4135 | parse_static_tracepoint_marker_definition (p, &p, &marker); |
5808517f | 4136 | |
5d9310c4 SM |
4137 | if (strid == NULL || marker.str_id == strid) |
4138 | markers.push_back (std::move (marker)); | |
5808517f YQ |
4139 | } |
4140 | while (*p++ == ','); /* comma-separated list */ | |
4141 | ||
4142 | memcpy (s, "qTsSTM", sizeof ("qTsSTM")); | |
4143 | s[sizeof ("qTsSTM")] = 0; | |
42476b70 | 4144 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4145 | p = s; |
4146 | } | |
4147 | ||
5808517f YQ |
4148 | return markers; |
4149 | } | |
4150 | ||
b84876c2 PA |
4151 | /* target_is_async_p implementation. */ |
4152 | ||
57810aa7 | 4153 | bool |
f6ac5f3d | 4154 | linux_nat_target::is_async_p () |
b84876c2 | 4155 | { |
198297aa | 4156 | return linux_is_async_p (); |
b84876c2 PA |
4157 | } |
4158 | ||
4159 | /* target_can_async_p implementation. */ | |
4160 | ||
57810aa7 | 4161 | bool |
f6ac5f3d | 4162 | linux_nat_target::can_async_p () |
b84876c2 | 4163 | { |
fde1b17d SM |
4164 | /* We're always async, unless the user explicitly prevented it with the |
4165 | "maint set target-async" command. */ | |
3dd5b83d | 4166 | return target_async_permitted; |
b84876c2 PA |
4167 | } |
4168 | ||
57810aa7 | 4169 | bool |
f6ac5f3d | 4170 | linux_nat_target::supports_non_stop () |
9908b566 VP |
4171 | { |
4172 | return 1; | |
4173 | } | |
4174 | ||
fbea99ea PA |
4175 | /* to_always_non_stop_p implementation. */ |
4176 | ||
57810aa7 | 4177 | bool |
f6ac5f3d | 4178 | linux_nat_target::always_non_stop_p () |
fbea99ea | 4179 | { |
f12899e9 | 4180 | return 1; |
fbea99ea PA |
4181 | } |
4182 | ||
d90e17a7 PA |
4183 | /* True if we want to support multi-process. To be removed when GDB |
4184 | supports multi-exec. */ | |
4185 | ||
2277426b | 4186 | int linux_multi_process = 1; |
d90e17a7 | 4187 | |
57810aa7 | 4188 | bool |
f6ac5f3d | 4189 | linux_nat_target::supports_multi_process () |
d90e17a7 PA |
4190 | { |
4191 | return linux_multi_process; | |
4192 | } | |
4193 | ||
57810aa7 | 4194 | bool |
f6ac5f3d | 4195 | linux_nat_target::supports_disable_randomization () |
03583c20 UW |
4196 | { |
4197 | #ifdef HAVE_PERSONALITY | |
4198 | return 1; | |
4199 | #else | |
4200 | return 0; | |
4201 | #endif | |
4202 | } | |
4203 | ||
7feb7d06 PA |
4204 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
4205 | so we notice when any child changes state, and notify the | |
4206 | event-loop; it allows us to use sigsuspend in linux_nat_wait_1 | |
4207 | above to wait for the arrival of a SIGCHLD. */ | |
4208 | ||
b84876c2 | 4209 | static void |
7feb7d06 | 4210 | sigchld_handler (int signo) |
b84876c2 | 4211 | { |
7feb7d06 PA |
4212 | int old_errno = errno; |
4213 | ||
01124a23 DE |
4214 | if (debug_linux_nat) |
4215 | ui_file_write_async_safe (gdb_stdlog, | |
4216 | "sigchld\n", sizeof ("sigchld\n") - 1); | |
7feb7d06 PA |
4217 | |
4218 | if (signo == SIGCHLD | |
4219 | && linux_nat_event_pipe[0] != -1) | |
4220 | async_file_mark (); /* Let the event loop know that there are | |
4221 | events to handle. */ | |
4222 | ||
4223 | errno = old_errno; | |
4224 | } | |
4225 | ||
4226 | /* Callback registered with the target events file descriptor. */ | |
4227 | ||
4228 | static void | |
4229 | handle_target_event (int error, gdb_client_data client_data) | |
4230 | { | |
6a3753b3 | 4231 | inferior_event_handler (INF_REG_EVENT, NULL); |
7feb7d06 PA |
4232 | } |
4233 | ||
4234 | /* Create/destroy the target events pipe. Returns previous state. */ | |
4235 | ||
4236 | static int | |
4237 | linux_async_pipe (int enable) | |
4238 | { | |
198297aa | 4239 | int previous = linux_is_async_p (); |
7feb7d06 PA |
4240 | |
4241 | if (previous != enable) | |
4242 | { | |
4243 | sigset_t prev_mask; | |
4244 | ||
12696c10 PA |
4245 | /* Block child signals while we create/destroy the pipe, as |
4246 | their handler writes to it. */ | |
7feb7d06 PA |
4247 | block_child_signals (&prev_mask); |
4248 | ||
4249 | if (enable) | |
4250 | { | |
614c279d | 4251 | if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1) |
7feb7d06 PA |
4252 | internal_error (__FILE__, __LINE__, |
4253 | "creating event pipe failed."); | |
4254 | ||
4255 | fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK); | |
4256 | fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK); | |
4257 | } | |
4258 | else | |
4259 | { | |
4260 | close (linux_nat_event_pipe[0]); | |
4261 | close (linux_nat_event_pipe[1]); | |
4262 | linux_nat_event_pipe[0] = -1; | |
4263 | linux_nat_event_pipe[1] = -1; | |
4264 | } | |
4265 | ||
4266 | restore_child_signals_mask (&prev_mask); | |
4267 | } | |
4268 | ||
4269 | return previous; | |
b84876c2 PA |
4270 | } |
4271 | ||
5b6d1e4f PA |
4272 | int |
4273 | linux_nat_target::async_wait_fd () | |
4274 | { | |
4275 | return linux_nat_event_pipe[0]; | |
4276 | } | |
4277 | ||
b84876c2 PA |
4278 | /* target_async implementation. */ |
4279 | ||
f6ac5f3d PA |
4280 | void |
4281 | linux_nat_target::async (int enable) | |
b84876c2 | 4282 | { |
6a3753b3 | 4283 | if (enable) |
b84876c2 | 4284 | { |
7feb7d06 PA |
4285 | if (!linux_async_pipe (1)) |
4286 | { | |
4287 | add_file_handler (linux_nat_event_pipe[0], | |
4288 | handle_target_event, NULL); | |
4289 | /* There may be pending events to handle. Tell the event loop | |
4290 | to poll them. */ | |
4291 | async_file_mark (); | |
4292 | } | |
b84876c2 PA |
4293 | } |
4294 | else | |
4295 | { | |
b84876c2 | 4296 | delete_file_handler (linux_nat_event_pipe[0]); |
7feb7d06 | 4297 | linux_async_pipe (0); |
b84876c2 PA |
4298 | } |
4299 | return; | |
4300 | } | |
4301 | ||
a493e3e2 | 4302 | /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other |
252fbfc8 PA |
4303 | event came out. */ |
4304 | ||
4c28f408 | 4305 | static int |
d3a70e03 | 4306 | linux_nat_stop_lwp (struct lwp_info *lwp) |
4c28f408 | 4307 | { |
d90e17a7 | 4308 | if (!lwp->stopped) |
252fbfc8 | 4309 | { |
d90e17a7 PA |
4310 | if (debug_linux_nat) |
4311 | fprintf_unfiltered (gdb_stdlog, | |
4312 | "LNSL: running -> suspending %s\n", | |
a068643d | 4313 | target_pid_to_str (lwp->ptid).c_str ()); |
252fbfc8 | 4314 | |
252fbfc8 | 4315 | |
25289eb2 PA |
4316 | if (lwp->last_resume_kind == resume_stop) |
4317 | { | |
4318 | if (debug_linux_nat) | |
4319 | fprintf_unfiltered (gdb_stdlog, | |
4320 | "linux-nat: already stopping LWP %ld at " | |
4321 | "GDB's request\n", | |
e38504b3 | 4322 | lwp->ptid.lwp ()); |
25289eb2 PA |
4323 | return 0; |
4324 | } | |
252fbfc8 | 4325 | |
d3a70e03 | 4326 | stop_callback (lwp); |
25289eb2 | 4327 | lwp->last_resume_kind = resume_stop; |
d90e17a7 PA |
4328 | } |
4329 | else | |
4330 | { | |
4331 | /* Already known to be stopped; do nothing. */ | |
252fbfc8 | 4332 | |
d90e17a7 PA |
4333 | if (debug_linux_nat) |
4334 | { | |
5b6d1e4f | 4335 | if (find_thread_ptid (linux_target, lwp->ptid)->stop_requested) |
3e43a32a MS |
4336 | fprintf_unfiltered (gdb_stdlog, |
4337 | "LNSL: already stopped/stop_requested %s\n", | |
a068643d | 4338 | target_pid_to_str (lwp->ptid).c_str ()); |
d90e17a7 | 4339 | else |
3e43a32a MS |
4340 | fprintf_unfiltered (gdb_stdlog, |
4341 | "LNSL: already stopped/no " | |
4342 | "stop_requested yet %s\n", | |
a068643d | 4343 | target_pid_to_str (lwp->ptid).c_str ()); |
252fbfc8 PA |
4344 | } |
4345 | } | |
4c28f408 PA |
4346 | return 0; |
4347 | } | |
4348 | ||
f6ac5f3d PA |
4349 | void |
4350 | linux_nat_target::stop (ptid_t ptid) | |
4c28f408 | 4351 | { |
d3a70e03 | 4352 | iterate_over_lwps (ptid, linux_nat_stop_lwp); |
bfedc46a PA |
4353 | } |
4354 | ||
f6ac5f3d PA |
4355 | void |
4356 | linux_nat_target::close () | |
d90e17a7 PA |
4357 | { |
4358 | /* Unregister from the event loop. */ | |
f6ac5f3d PA |
4359 | if (is_async_p ()) |
4360 | async (0); | |
d90e17a7 | 4361 | |
f6ac5f3d | 4362 | inf_ptrace_target::close (); |
d90e17a7 PA |
4363 | } |
4364 | ||
c0694254 PA |
4365 | /* When requests are passed down from the linux-nat layer to the |
4366 | single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are | |
4367 | used. The address space pointer is stored in the inferior object, | |
4368 | but the common code that is passed such ptid can't tell whether | |
4369 | lwpid is a "main" process id or not (it assumes so). We reverse | |
4370 | look up the "main" process id from the lwp here. */ | |
4371 | ||
f6ac5f3d PA |
4372 | struct address_space * |
4373 | linux_nat_target::thread_address_space (ptid_t ptid) | |
c0694254 PA |
4374 | { |
4375 | struct lwp_info *lwp; | |
4376 | struct inferior *inf; | |
4377 | int pid; | |
4378 | ||
e38504b3 | 4379 | if (ptid.lwp () == 0) |
c0694254 PA |
4380 | { |
4381 | /* An (lwpid,0,0) ptid. Look up the lwp object to get at the | |
4382 | tgid. */ | |
4383 | lwp = find_lwp_pid (ptid); | |
e99b03dc | 4384 | pid = lwp->ptid.pid (); |
c0694254 PA |
4385 | } |
4386 | else | |
4387 | { | |
4388 | /* A (pid,lwpid,0) ptid. */ | |
e99b03dc | 4389 | pid = ptid.pid (); |
c0694254 PA |
4390 | } |
4391 | ||
5b6d1e4f | 4392 | inf = find_inferior_pid (this, pid); |
c0694254 PA |
4393 | gdb_assert (inf != NULL); |
4394 | return inf->aspace; | |
4395 | } | |
4396 | ||
dc146f7c VP |
4397 | /* Return the cached value of the processor core for thread PTID. */ |
4398 | ||
f6ac5f3d PA |
4399 | int |
4400 | linux_nat_target::core_of_thread (ptid_t ptid) | |
dc146f7c VP |
4401 | { |
4402 | struct lwp_info *info = find_lwp_pid (ptid); | |
e0881a8e | 4403 | |
dc146f7c VP |
4404 | if (info) |
4405 | return info->core; | |
4406 | return -1; | |
4407 | } | |
4408 | ||
7a6a1731 GB |
4409 | /* Implementation of to_filesystem_is_local. */ |
4410 | ||
57810aa7 | 4411 | bool |
f6ac5f3d | 4412 | linux_nat_target::filesystem_is_local () |
7a6a1731 GB |
4413 | { |
4414 | struct inferior *inf = current_inferior (); | |
4415 | ||
4416 | if (inf->fake_pid_p || inf->pid == 0) | |
57810aa7 | 4417 | return true; |
7a6a1731 GB |
4418 | |
4419 | return linux_ns_same (inf->pid, LINUX_NS_MNT); | |
4420 | } | |
4421 | ||
4422 | /* Convert the INF argument passed to a to_fileio_* method | |
4423 | to a process ID suitable for passing to its corresponding | |
4424 | linux_mntns_* function. If INF is non-NULL then the | |
4425 | caller is requesting the filesystem seen by INF. If INF | |
4426 | is NULL then the caller is requesting the filesystem seen | |
4427 | by the GDB. We fall back to GDB's filesystem in the case | |
4428 | that INF is non-NULL but its PID is unknown. */ | |
4429 | ||
4430 | static pid_t | |
4431 | linux_nat_fileio_pid_of (struct inferior *inf) | |
4432 | { | |
4433 | if (inf == NULL || inf->fake_pid_p || inf->pid == 0) | |
4434 | return getpid (); | |
4435 | else | |
4436 | return inf->pid; | |
4437 | } | |
4438 | ||
4439 | /* Implementation of to_fileio_open. */ | |
4440 | ||
f6ac5f3d PA |
4441 | int |
4442 | linux_nat_target::fileio_open (struct inferior *inf, const char *filename, | |
4443 | int flags, int mode, int warn_if_slow, | |
4444 | int *target_errno) | |
7a6a1731 GB |
4445 | { |
4446 | int nat_flags; | |
4447 | mode_t nat_mode; | |
4448 | int fd; | |
4449 | ||
4450 | if (fileio_to_host_openflags (flags, &nat_flags) == -1 | |
4451 | || fileio_to_host_mode (mode, &nat_mode) == -1) | |
4452 | { | |
4453 | *target_errno = FILEIO_EINVAL; | |
4454 | return -1; | |
4455 | } | |
4456 | ||
4457 | fd = linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf), | |
4458 | filename, nat_flags, nat_mode); | |
4459 | if (fd == -1) | |
4460 | *target_errno = host_to_fileio_error (errno); | |
4461 | ||
4462 | return fd; | |
4463 | } | |
4464 | ||
4465 | /* Implementation of to_fileio_readlink. */ | |
4466 | ||
f6ac5f3d PA |
4467 | gdb::optional<std::string> |
4468 | linux_nat_target::fileio_readlink (struct inferior *inf, const char *filename, | |
4469 | int *target_errno) | |
7a6a1731 GB |
4470 | { |
4471 | char buf[PATH_MAX]; | |
4472 | int len; | |
7a6a1731 GB |
4473 | |
4474 | len = linux_mntns_readlink (linux_nat_fileio_pid_of (inf), | |
4475 | filename, buf, sizeof (buf)); | |
4476 | if (len < 0) | |
4477 | { | |
4478 | *target_errno = host_to_fileio_error (errno); | |
e0d3522b | 4479 | return {}; |
7a6a1731 GB |
4480 | } |
4481 | ||
e0d3522b | 4482 | return std::string (buf, len); |
7a6a1731 GB |
4483 | } |
4484 | ||
4485 | /* Implementation of to_fileio_unlink. */ | |
4486 | ||
f6ac5f3d PA |
4487 | int |
4488 | linux_nat_target::fileio_unlink (struct inferior *inf, const char *filename, | |
4489 | int *target_errno) | |
7a6a1731 GB |
4490 | { |
4491 | int ret; | |
4492 | ||
4493 | ret = linux_mntns_unlink (linux_nat_fileio_pid_of (inf), | |
4494 | filename); | |
4495 | if (ret == -1) | |
4496 | *target_errno = host_to_fileio_error (errno); | |
4497 | ||
4498 | return ret; | |
4499 | } | |
4500 | ||
aa01bd36 PA |
4501 | /* Implementation of the to_thread_events method. */ |
4502 | ||
f6ac5f3d PA |
4503 | void |
4504 | linux_nat_target::thread_events (int enable) | |
aa01bd36 PA |
4505 | { |
4506 | report_thread_events = enable; | |
4507 | } | |
4508 | ||
f6ac5f3d PA |
4509 | linux_nat_target::linux_nat_target () |
4510 | { | |
f973ed9c DJ |
4511 | /* We don't change the stratum; this target will sit at |
4512 | process_stratum and thread_db will set at thread_stratum. This | |
4513 | is a little strange, since this is a multi-threaded-capable | |
4514 | target, but we want to be on the stack below thread_db, and we | |
4515 | also want to be used for single-threaded processes. */ | |
f973ed9c DJ |
4516 | } |
4517 | ||
f865ee35 JK |
4518 | /* See linux-nat.h. */ |
4519 | ||
4520 | int | |
4521 | linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo) | |
9f0bdab8 | 4522 | { |
da559b09 | 4523 | int pid; |
9f0bdab8 | 4524 | |
e38504b3 | 4525 | pid = ptid.lwp (); |
da559b09 | 4526 | if (pid == 0) |
e99b03dc | 4527 | pid = ptid.pid (); |
f865ee35 | 4528 | |
da559b09 JK |
4529 | errno = 0; |
4530 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo); | |
4531 | if (errno != 0) | |
4532 | { | |
4533 | memset (siginfo, 0, sizeof (*siginfo)); | |
4534 | return 0; | |
4535 | } | |
f865ee35 | 4536 | return 1; |
9f0bdab8 DJ |
4537 | } |
4538 | ||
7b669087 GB |
4539 | /* See nat/linux-nat.h. */ |
4540 | ||
4541 | ptid_t | |
4542 | current_lwp_ptid (void) | |
4543 | { | |
15a9e13e | 4544 | gdb_assert (inferior_ptid.lwp_p ()); |
7b669087 GB |
4545 | return inferior_ptid; |
4546 | } | |
4547 | ||
d6b0e80f AC |
4548 | void |
4549 | _initialize_linux_nat (void) | |
4550 | { | |
ccce17b0 YQ |
4551 | add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance, |
4552 | &debug_linux_nat, _("\ | |
b84876c2 PA |
4553 | Set debugging of GNU/Linux lwp module."), _("\ |
4554 | Show debugging of GNU/Linux lwp module."), _("\ | |
4555 | Enables printf debugging output."), | |
ccce17b0 YQ |
4556 | NULL, |
4557 | show_debug_linux_nat, | |
4558 | &setdebuglist, &showdebuglist); | |
b84876c2 | 4559 | |
7a6a1731 GB |
4560 | add_setshow_boolean_cmd ("linux-namespaces", class_maintenance, |
4561 | &debug_linux_namespaces, _("\ | |
4562 | Set debugging of GNU/Linux namespaces module."), _("\ | |
4563 | Show debugging of GNU/Linux namespaces module."), _("\ | |
4564 | Enables printf debugging output."), | |
4565 | NULL, | |
4566 | NULL, | |
4567 | &setdebuglist, &showdebuglist); | |
4568 | ||
7feb7d06 PA |
4569 | /* Install a SIGCHLD handler. */ |
4570 | sigchld_action.sa_handler = sigchld_handler; | |
4571 | sigemptyset (&sigchld_action.sa_mask); | |
4572 | sigchld_action.sa_flags = SA_RESTART; | |
b84876c2 PA |
4573 | |
4574 | /* Make it the default. */ | |
7feb7d06 | 4575 | sigaction (SIGCHLD, &sigchld_action, NULL); |
d6b0e80f AC |
4576 | |
4577 | /* Make sure we don't block SIGCHLD during a sigsuspend. */ | |
21987b9c | 4578 | gdb_sigmask (SIG_SETMASK, NULL, &suspend_mask); |
d6b0e80f AC |
4579 | sigdelset (&suspend_mask, SIGCHLD); |
4580 | ||
7feb7d06 | 4581 | sigemptyset (&blocked_mask); |
774113b0 PA |
4582 | |
4583 | lwp_lwpid_htab_create (); | |
d6b0e80f AC |
4584 | } |
4585 | \f | |
4586 | ||
4587 | /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to | |
4588 | the GNU/Linux Threads library and therefore doesn't really belong | |
4589 | here. */ | |
4590 | ||
d6b0e80f AC |
4591 | /* Return the set of signals used by the threads library in *SET. */ |
4592 | ||
4593 | void | |
4594 | lin_thread_get_thread_signals (sigset_t *set) | |
4595 | { | |
d6b0e80f AC |
4596 | sigemptyset (set); |
4597 | ||
4a6ed09b PA |
4598 | /* NPTL reserves the first two RT signals, but does not provide any |
4599 | way for the debugger to query the signal numbers - fortunately | |
4600 | they don't change. */ | |
4601 | sigaddset (set, __SIGRTMIN); | |
4602 | sigaddset (set, __SIGRTMIN + 1); | |
d6b0e80f | 4603 | } |