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3993f6b1 | 1 | /* GNU/Linux native-dependent code common to multiple platforms. |
dba24537 | 2 | |
1d506c26 | 3 | Copyright (C) 2001-2024 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 | 19 | |
3993f6b1 | 20 | #include "inferior.h" |
45741a9c | 21 | #include "infrun.h" |
3993f6b1 | 22 | #include "target.h" |
96d7229d LM |
23 | #include "nat/linux-nat.h" |
24 | #include "nat/linux-waitpid.h" | |
268a13a5 | 25 | #include "gdbsupport/gdb_wait.h" |
d6b0e80f AC |
26 | #include <unistd.h> |
27 | #include <sys/syscall.h> | |
5826e159 | 28 | #include "nat/gdb_ptrace.h" |
0274a8ce | 29 | #include "linux-nat.h" |
125f8a3d GB |
30 | #include "nat/linux-ptrace.h" |
31 | #include "nat/linux-procfs.h" | |
8cc73a39 | 32 | #include "nat/linux-personality.h" |
ac264b3b | 33 | #include "linux-fork.h" |
d6b0e80f | 34 | #include "gdbthread.h" |
5b9707eb | 35 | #include "cli/cli-cmds.h" |
d6b0e80f | 36 | #include "regcache.h" |
4f844a66 | 37 | #include "regset.h" |
dab06dbe | 38 | #include "inf-child.h" |
10d6c8cd DJ |
39 | #include "inf-ptrace.h" |
40 | #include "auxv.h" | |
ef0f16cc TT |
41 | #include <sys/procfs.h> |
42 | #include "elf-bfd.h" | |
43 | #include "gregset.h" | |
44 | #include "gdbcore.h" | |
45 | #include <ctype.h> | |
46 | #include <sys/stat.h> | |
47 | #include <fcntl.h> | |
b84876c2 | 48 | #include "inf-loop.h" |
400b5eca | 49 | #include "gdbsupport/event-loop.h" |
b84876c2 | 50 | #include "event-top.h" |
07e059b5 VP |
51 | #include <pwd.h> |
52 | #include <sys/types.h> | |
2978b111 | 53 | #include <dirent.h> |
07e059b5 | 54 | #include "xml-support.h" |
efcbbd14 | 55 | #include <sys/vfs.h> |
6c95b8df | 56 | #include "solib.h" |
125f8a3d | 57 | #include "nat/linux-osdata.h" |
6432734d | 58 | #include "linux-tdep.h" |
7dcd53a0 | 59 | #include "symfile.h" |
268a13a5 | 60 | #include "gdbsupport/agent.h" |
5808517f | 61 | #include "tracepoint.h" |
6ecd4729 | 62 | #include "target-descriptions.h" |
268a13a5 | 63 | #include "gdbsupport/filestuff.h" |
77e371c0 | 64 | #include "objfiles.h" |
7a6a1731 | 65 | #include "nat/linux-namespaces.h" |
b146ba14 | 66 | #include "gdbsupport/block-signals.h" |
268a13a5 TT |
67 | #include "gdbsupport/fileio.h" |
68 | #include "gdbsupport/scope-exit.h" | |
21987b9c | 69 | #include "gdbsupport/gdb-sigmask.h" |
ba988419 | 70 | #include "gdbsupport/common-debug.h" |
8a89ddbd | 71 | #include <unordered_map> |
efcbbd14 | 72 | |
1777feb0 | 73 | /* This comment documents high-level logic of this file. |
8a77dff3 VP |
74 | |
75 | Waiting for events in sync mode | |
76 | =============================== | |
77 | ||
4a6ed09b PA |
78 | When waiting for an event in a specific thread, we just use waitpid, |
79 | passing the specific pid, and not passing WNOHANG. | |
80 | ||
81 | When waiting for an event in all threads, waitpid is not quite good: | |
82 | ||
83 | - If the thread group leader exits while other threads in the thread | |
84 | group still exist, waitpid(TGID, ...) hangs. That waitpid won't | |
85 | return an exit status until the other threads in the group are | |
86 | reaped. | |
87 | ||
88 | - When a non-leader thread execs, that thread just vanishes without | |
89 | reporting an exit (so we'd hang if we waited for it explicitly in | |
90 | that case). The exec event is instead reported to the TGID pid. | |
91 | ||
92 | The solution is to always use -1 and WNOHANG, together with | |
93 | sigsuspend. | |
94 | ||
95 | First, we use non-blocking waitpid to check for events. If nothing is | |
96 | found, we use sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, | |
97 | it means something happened to a child process. As soon as we know | |
98 | there's an event, we get back to calling nonblocking waitpid. | |
99 | ||
100 | Note that SIGCHLD should be blocked between waitpid and sigsuspend | |
101 | calls, so that we don't miss a signal. If SIGCHLD arrives in between, | |
102 | when it's blocked, the signal becomes pending and sigsuspend | |
103 | immediately notices it and returns. | |
104 | ||
105 | Waiting for events in async mode (TARGET_WNOHANG) | |
106 | ================================================= | |
8a77dff3 | 107 | |
7feb7d06 PA |
108 | In async mode, GDB should always be ready to handle both user input |
109 | and target events, so neither blocking waitpid nor sigsuspend are | |
110 | viable options. Instead, we should asynchronously notify the GDB main | |
111 | event loop whenever there's an unprocessed event from the target. We | |
112 | detect asynchronous target events by handling SIGCHLD signals. To | |
c150bdf0 JB |
113 | notify the event loop about target events, an event pipe is used |
114 | --- the pipe is registered as waitable event source in the event loop, | |
7feb7d06 | 115 | the event loop select/poll's on the read end of this pipe (as well on |
c150bdf0 JB |
116 | other event sources, e.g., stdin), and the SIGCHLD handler marks the |
117 | event pipe to raise an event. This is more portable than relying on | |
7feb7d06 PA |
118 | pselect/ppoll, since on kernels that lack those syscalls, libc |
119 | emulates them with select/poll+sigprocmask, and that is racy | |
120 | (a.k.a. plain broken). | |
121 | ||
122 | Obviously, if we fail to notify the event loop if there's a target | |
123 | event, it's bad. OTOH, if we notify the event loop when there's no | |
124 | event from the target, linux_nat_wait will detect that there's no real | |
125 | event to report, and return event of type TARGET_WAITKIND_IGNORE. | |
126 | This is mostly harmless, but it will waste time and is better avoided. | |
127 | ||
128 | The main design point is that every time GDB is outside linux-nat.c, | |
129 | we have a SIGCHLD handler installed that is called when something | |
130 | happens to the target and notifies the GDB event loop. Whenever GDB | |
131 | core decides to handle the event, and calls into linux-nat.c, we | |
132 | process things as in sync mode, except that the we never block in | |
133 | sigsuspend. | |
134 | ||
135 | While processing an event, we may end up momentarily blocked in | |
136 | waitpid calls. Those waitpid calls, while blocking, are guarantied to | |
137 | return quickly. E.g., in all-stop mode, before reporting to the core | |
138 | that an LWP hit a breakpoint, all LWPs are stopped by sending them | |
139 | SIGSTOP, and synchronously waiting for the SIGSTOP to be reported. | |
140 | Note that this is different from blocking indefinitely waiting for the | |
141 | next event --- here, we're already handling an event. | |
8a77dff3 VP |
142 | |
143 | Use of signals | |
144 | ============== | |
145 | ||
146 | We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another | |
147 | signal is not entirely significant; we just need for a signal to be delivered, | |
148 | so that we can intercept it. SIGSTOP's advantage is that it can not be | |
149 | blocked. A disadvantage is that it is not a real-time signal, so it can only | |
150 | be queued once; we do not keep track of other sources of SIGSTOP. | |
151 | ||
152 | Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't | |
153 | use them, because they have special behavior when the signal is generated - | |
154 | not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL | |
155 | kills the entire thread group. | |
156 | ||
157 | A delivered SIGSTOP would stop the entire thread group, not just the thread we | |
158 | tkill'd. But we never let the SIGSTOP be delivered; we always intercept and | |
159 | cancel it (by PTRACE_CONT without passing SIGSTOP). | |
160 | ||
161 | We could use a real-time signal instead. This would solve those problems; we | |
162 | could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB. | |
163 | But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH | |
164 | generates it, and there are races with trying to find a signal that is not | |
4a6ed09b PA |
165 | blocked. |
166 | ||
167 | Exec events | |
168 | =========== | |
169 | ||
170 | The case of a thread group (process) with 3 or more threads, and a | |
171 | thread other than the leader execs is worth detailing: | |
172 | ||
173 | On an exec, the Linux kernel destroys all threads except the execing | |
174 | one in the thread group, and resets the execing thread's tid to the | |
175 | tgid. No exit notification is sent for the execing thread -- from the | |
176 | ptracer's perspective, it appears as though the execing thread just | |
177 | vanishes. Until we reap all other threads except the leader and the | |
178 | execing thread, the leader will be zombie, and the execing thread will | |
179 | be in `D (disc sleep)' state. As soon as all other threads are | |
180 | reaped, the execing thread changes its tid to the tgid, and the | |
181 | previous (zombie) leader vanishes, giving place to the "new" | |
bd659b80 PA |
182 | leader. |
183 | ||
184 | Accessing inferior memory | |
185 | ========================= | |
186 | ||
187 | To access inferior memory, we strongly prefer /proc/PID/mem. We | |
188 | fallback to ptrace if and only if /proc/PID/mem is not writable, as a | |
189 | concession for obsolescent kernels (such as found in RHEL6). For | |
190 | modern kernels, the fallback shouldn't trigger. GDBserver does not | |
191 | have the ptrace fallback already, and at some point, we'll consider | |
192 | removing it from native GDB too. | |
193 | ||
194 | /proc/PID/mem has a few advantages over alternatives like | |
195 | PTRACE_PEEKTEXT/PTRACE_POKETEXT or process_vm_readv/process_vm_writev: | |
196 | ||
197 | - Because we can use a single read/write call, /proc/PID/mem can be | |
198 | much more efficient than banging away at | |
199 | PTRACE_PEEKTEXT/PTRACE_POKETEXT, one word at a time. | |
200 | ||
201 | - /proc/PID/mem allows writing to read-only pages, which we need to | |
202 | e.g., plant breakpoint instructions. process_vm_writev does not | |
203 | allow this. | |
204 | ||
205 | - /proc/PID/mem allows memory access even if all threads are running. | |
206 | OTOH, PTRACE_PEEKTEXT/PTRACE_POKETEXT require passing down the tid | |
207 | of a stopped task. This lets us e.g., install breakpoints while the | |
208 | inferior is running, clear a displaced stepping scratch pad when the | |
209 | thread that was displaced stepping exits, print inferior globals, | |
210 | etc., all without having to worry about temporarily pausing some | |
211 | thread. | |
212 | ||
213 | - /proc/PID/mem does not suffer from a race that could cause us to | |
214 | access memory of the wrong address space when the inferior execs. | |
215 | ||
216 | process_vm_readv/process_vm_writev have this problem. | |
217 | ||
218 | E.g., say GDB decides to write to memory just while the inferior | |
219 | execs. In this scenario, GDB could write memory to the post-exec | |
220 | address space thinking it was writing to the pre-exec address space, | |
221 | with high probability of corrupting the inferior. Or if GDB decides | |
222 | instead to read memory just while the inferior execs, it could read | |
223 | bogus contents out of the wrong address space. | |
224 | ||
225 | ptrace used to have this problem too, but no longer has since Linux | |
226 | commit dbb5afad100a ("ptrace: make ptrace() fail if the tracee | |
227 | changed its pid unexpectedly"), in Linux 5.13. (And if ptrace were | |
228 | ever changed to allow access memory via zombie or running threads, | |
229 | it would better not forget to consider this scenario.) | |
230 | ||
231 | We avoid this race with /proc/PID/mem, by opening the file as soon | |
232 | as we start debugging the inferior, when it is known the inferior is | |
233 | stopped, and holding on to the open file descriptor, to be used | |
234 | whenever we need to access inferior memory. If the inferior execs | |
235 | or exits, reading/writing from/to the file returns 0 (EOF), | |
236 | indicating the address space is gone, and so we return | |
237 | TARGET_XFER_EOF to the core. We close the old file and open a new | |
238 | one when we finally see the PTRACE_EVENT_EXEC event. */ | |
a0ef4274 | 239 | |
dba24537 AC |
240 | #ifndef O_LARGEFILE |
241 | #define O_LARGEFILE 0 | |
242 | #endif | |
0274a8ce | 243 | |
f6ac5f3d PA |
244 | struct linux_nat_target *linux_target; |
245 | ||
433bbbf8 | 246 | /* Does the current host support PTRACE_GETREGSET? */ |
0bdb2f78 | 247 | enum tribool have_ptrace_getregset = TRIBOOL_UNKNOWN; |
433bbbf8 | 248 | |
b6e52a0b AB |
249 | /* When true, print debug messages relating to the linux native target. */ |
250 | ||
251 | static bool debug_linux_nat; | |
252 | ||
8864ef42 | 253 | /* Implement 'show debug linux-nat'. */ |
b6e52a0b | 254 | |
920d2a44 AC |
255 | static void |
256 | show_debug_linux_nat (struct ui_file *file, int from_tty, | |
257 | struct cmd_list_element *c, const char *value) | |
258 | { | |
6cb06a8c TT |
259 | gdb_printf (file, _("Debugging of GNU/Linux native targets is %s.\n"), |
260 | value); | |
920d2a44 | 261 | } |
d6b0e80f | 262 | |
17417fb0 | 263 | /* Print a linux-nat debug statement. */ |
9327494e SM |
264 | |
265 | #define linux_nat_debug_printf(fmt, ...) \ | |
74b773fc | 266 | debug_prefixed_printf_cond (debug_linux_nat, "linux-nat", fmt, ##__VA_ARGS__) |
9327494e | 267 | |
b6e52a0b AB |
268 | /* Print "linux-nat" enter/exit debug statements. */ |
269 | ||
270 | #define LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT \ | |
271 | scoped_debug_enter_exit (debug_linux_nat, "linux-nat") | |
272 | ||
ae087d01 DJ |
273 | struct simple_pid_list |
274 | { | |
275 | int pid; | |
3d799a95 | 276 | int status; |
ae087d01 DJ |
277 | struct simple_pid_list *next; |
278 | }; | |
05c309a8 | 279 | static struct simple_pid_list *stopped_pids; |
ae087d01 | 280 | |
aa01bd36 PA |
281 | /* Whether target_thread_events is in effect. */ |
282 | static int report_thread_events; | |
283 | ||
7feb7d06 PA |
284 | static int kill_lwp (int lwpid, int signo); |
285 | ||
d3a70e03 | 286 | static int stop_callback (struct lwp_info *lp); |
7feb7d06 PA |
287 | |
288 | static void block_child_signals (sigset_t *prev_mask); | |
289 | static void restore_child_signals_mask (sigset_t *prev_mask); | |
2277426b PA |
290 | |
291 | struct lwp_info; | |
292 | static struct lwp_info *add_lwp (ptid_t ptid); | |
293 | static void purge_lwp_list (int pid); | |
4403d8e9 | 294 | static void delete_lwp (ptid_t ptid); |
2277426b PA |
295 | static struct lwp_info *find_lwp_pid (ptid_t ptid); |
296 | ||
8a99810d PA |
297 | static int lwp_status_pending_p (struct lwp_info *lp); |
298 | ||
5e86aab8 PA |
299 | static bool is_lwp_marked_dead (lwp_info *lp); |
300 | ||
e7ad2f14 PA |
301 | static void save_stop_reason (struct lwp_info *lp); |
302 | ||
1bcb0708 | 303 | static bool proc_mem_file_is_writable (); |
8a89ddbd PA |
304 | static void close_proc_mem_file (pid_t pid); |
305 | static void open_proc_mem_file (ptid_t ptid); | |
05c06f31 | 306 | |
6cf20c46 PA |
307 | /* Return TRUE if LWP is the leader thread of the process. */ |
308 | ||
309 | static bool | |
310 | is_leader (lwp_info *lp) | |
311 | { | |
312 | return lp->ptid.pid () == lp->ptid.lwp (); | |
313 | } | |
314 | ||
57573e54 PA |
315 | /* Convert an LWP's pending status to a std::string. */ |
316 | ||
317 | static std::string | |
318 | pending_status_str (lwp_info *lp) | |
319 | { | |
320 | gdb_assert (lwp_status_pending_p (lp)); | |
321 | ||
322 | if (lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE) | |
323 | return lp->waitstatus.to_string (); | |
324 | else | |
325 | return status_to_str (lp->status); | |
326 | } | |
327 | ||
a51e14ef PA |
328 | /* Return true if we should report exit events for LP. */ |
329 | ||
330 | static bool | |
331 | report_exit_events_for (lwp_info *lp) | |
332 | { | |
333 | thread_info *thr = linux_target->find_thread (lp->ptid); | |
334 | gdb_assert (thr != nullptr); | |
335 | ||
336 | return (report_thread_events | |
337 | || (thr->thread_options () & GDB_THREAD_OPTION_EXIT) != 0); | |
338 | } | |
339 | ||
cff068da GB |
340 | \f |
341 | /* LWP accessors. */ | |
342 | ||
343 | /* See nat/linux-nat.h. */ | |
344 | ||
345 | ptid_t | |
346 | ptid_of_lwp (struct lwp_info *lwp) | |
347 | { | |
348 | return lwp->ptid; | |
349 | } | |
350 | ||
351 | /* See nat/linux-nat.h. */ | |
352 | ||
4b134ca1 GB |
353 | void |
354 | lwp_set_arch_private_info (struct lwp_info *lwp, | |
355 | struct arch_lwp_info *info) | |
356 | { | |
357 | lwp->arch_private = info; | |
358 | } | |
359 | ||
360 | /* See nat/linux-nat.h. */ | |
361 | ||
362 | struct arch_lwp_info * | |
363 | lwp_arch_private_info (struct lwp_info *lwp) | |
364 | { | |
365 | return lwp->arch_private; | |
366 | } | |
367 | ||
368 | /* See nat/linux-nat.h. */ | |
369 | ||
cff068da GB |
370 | int |
371 | lwp_is_stopped (struct lwp_info *lwp) | |
372 | { | |
373 | return lwp->stopped; | |
374 | } | |
375 | ||
376 | /* See nat/linux-nat.h. */ | |
377 | ||
378 | enum target_stop_reason | |
379 | lwp_stop_reason (struct lwp_info *lwp) | |
380 | { | |
381 | return lwp->stop_reason; | |
382 | } | |
383 | ||
0e00e962 AA |
384 | /* See nat/linux-nat.h. */ |
385 | ||
386 | int | |
387 | lwp_is_stepping (struct lwp_info *lwp) | |
388 | { | |
389 | return lwp->step; | |
390 | } | |
391 | ||
ae087d01 DJ |
392 | \f |
393 | /* Trivial list manipulation functions to keep track of a list of | |
394 | new stopped processes. */ | |
395 | static void | |
3d799a95 | 396 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
ae087d01 | 397 | { |
8d749320 | 398 | struct simple_pid_list *new_pid = XNEW (struct simple_pid_list); |
e0881a8e | 399 | |
ae087d01 | 400 | new_pid->pid = pid; |
3d799a95 | 401 | new_pid->status = status; |
ae087d01 DJ |
402 | new_pid->next = *listp; |
403 | *listp = new_pid; | |
404 | } | |
405 | ||
406 | static int | |
46a96992 | 407 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
ae087d01 DJ |
408 | { |
409 | struct simple_pid_list **p; | |
410 | ||
411 | for (p = listp; *p != NULL; p = &(*p)->next) | |
412 | if ((*p)->pid == pid) | |
413 | { | |
414 | struct simple_pid_list *next = (*p)->next; | |
e0881a8e | 415 | |
46a96992 | 416 | *statusp = (*p)->status; |
ae087d01 DJ |
417 | xfree (*p); |
418 | *p = next; | |
419 | return 1; | |
420 | } | |
421 | return 0; | |
422 | } | |
423 | ||
de0d863e DB |
424 | /* Return the ptrace options that we want to try to enable. */ |
425 | ||
426 | static int | |
427 | linux_nat_ptrace_options (int attached) | |
428 | { | |
429 | int options = 0; | |
430 | ||
431 | if (!attached) | |
432 | options |= PTRACE_O_EXITKILL; | |
433 | ||
434 | options |= (PTRACE_O_TRACESYSGOOD | |
435 | | PTRACE_O_TRACEVFORKDONE | |
436 | | PTRACE_O_TRACEVFORK | |
437 | | PTRACE_O_TRACEFORK | |
438 | | PTRACE_O_TRACEEXEC); | |
439 | ||
440 | return options; | |
441 | } | |
442 | ||
1b919490 VB |
443 | /* Initialize ptrace and procfs warnings and check for supported |
444 | ptrace features given PID. | |
beed38b8 JB |
445 | |
446 | ATTACHED should be nonzero iff we attached to the inferior. */ | |
3993f6b1 DJ |
447 | |
448 | static void | |
1b919490 | 449 | linux_init_ptrace_procfs (pid_t pid, int attached) |
3993f6b1 | 450 | { |
de0d863e DB |
451 | int options = linux_nat_ptrace_options (attached); |
452 | ||
453 | linux_enable_event_reporting (pid, options); | |
96d7229d | 454 | linux_ptrace_init_warnings (); |
1b919490 | 455 | linux_proc_init_warnings (); |
9dff6a5d | 456 | proc_mem_file_is_writable (); |
4de4c07c DJ |
457 | } |
458 | ||
f6ac5f3d PA |
459 | linux_nat_target::~linux_nat_target () |
460 | {} | |
461 | ||
462 | void | |
463 | linux_nat_target::post_attach (int pid) | |
4de4c07c | 464 | { |
1b919490 | 465 | linux_init_ptrace_procfs (pid, 1); |
4de4c07c DJ |
466 | } |
467 | ||
200fd287 AB |
468 | /* Implement the virtual inf_ptrace_target::post_startup_inferior method. */ |
469 | ||
f6ac5f3d PA |
470 | void |
471 | linux_nat_target::post_startup_inferior (ptid_t ptid) | |
4de4c07c | 472 | { |
1b919490 | 473 | linux_init_ptrace_procfs (ptid.pid (), 0); |
4de4c07c DJ |
474 | } |
475 | ||
4403d8e9 JK |
476 | /* Return the number of known LWPs in the tgid given by PID. */ |
477 | ||
478 | static int | |
479 | num_lwps (int pid) | |
480 | { | |
481 | int count = 0; | |
4403d8e9 | 482 | |
901b9821 | 483 | for (const lwp_info *lp ATTRIBUTE_UNUSED : all_lwps ()) |
e99b03dc | 484 | if (lp->ptid.pid () == pid) |
4403d8e9 JK |
485 | count++; |
486 | ||
487 | return count; | |
488 | } | |
489 | ||
169bb27b | 490 | /* Deleter for lwp_info unique_ptr specialisation. */ |
4403d8e9 | 491 | |
169bb27b | 492 | struct lwp_deleter |
4403d8e9 | 493 | { |
169bb27b AB |
494 | void operator() (struct lwp_info *lwp) const |
495 | { | |
496 | delete_lwp (lwp->ptid); | |
497 | } | |
498 | }; | |
4403d8e9 | 499 | |
169bb27b AB |
500 | /* A unique_ptr specialisation for lwp_info. */ |
501 | ||
502 | typedef std::unique_ptr<struct lwp_info, lwp_deleter> lwp_info_up; | |
4403d8e9 | 503 | |
82d1f134 | 504 | /* Target hook for follow_fork. */ |
d83ad864 | 505 | |
e97007b6 | 506 | void |
82d1f134 SM |
507 | linux_nat_target::follow_fork (inferior *child_inf, ptid_t child_ptid, |
508 | target_waitkind fork_kind, bool follow_child, | |
509 | bool detach_fork) | |
3993f6b1 | 510 | { |
82d1f134 SM |
511 | inf_ptrace_target::follow_fork (child_inf, child_ptid, fork_kind, |
512 | follow_child, detach_fork); | |
513 | ||
d83ad864 | 514 | if (!follow_child) |
4de4c07c | 515 | { |
3a849a34 SM |
516 | bool has_vforked = fork_kind == TARGET_WAITKIND_VFORKED; |
517 | ptid_t parent_ptid = inferior_ptid; | |
3a849a34 SM |
518 | int parent_pid = parent_ptid.lwp (); |
519 | int child_pid = child_ptid.lwp (); | |
4de4c07c | 520 | |
1777feb0 | 521 | /* We're already attached to the parent, by default. */ |
3a849a34 | 522 | lwp_info *child_lp = add_lwp (child_ptid); |
d83ad864 DB |
523 | child_lp->stopped = 1; |
524 | child_lp->last_resume_kind = resume_stop; | |
4de4c07c | 525 | |
ac264b3b MS |
526 | /* Detach new forked process? */ |
527 | if (detach_fork) | |
f75c00e4 | 528 | { |
95347337 AB |
529 | int child_stop_signal = 0; |
530 | bool detach_child = true; | |
4403d8e9 | 531 | |
169bb27b AB |
532 | /* Move CHILD_LP into a unique_ptr and clear the source pointer |
533 | to prevent us doing anything stupid with it. */ | |
534 | lwp_info_up child_lp_ptr (child_lp); | |
535 | child_lp = nullptr; | |
536 | ||
537 | linux_target->low_prepare_to_resume (child_lp_ptr.get ()); | |
c077881a HZ |
538 | |
539 | /* When debugging an inferior in an architecture that supports | |
540 | hardware single stepping on a kernel without commit | |
541 | 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child | |
542 | process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits | |
543 | set if the parent process had them set. | |
544 | To work around this, single step the child process | |
545 | once before detaching to clear the flags. */ | |
546 | ||
2fd9d7ca PA |
547 | /* Note that we consult the parent's architecture instead of |
548 | the child's because there's no inferior for the child at | |
549 | this point. */ | |
c077881a | 550 | if (!gdbarch_software_single_step_p (target_thread_architecture |
2fd9d7ca | 551 | (parent_ptid))) |
c077881a | 552 | { |
95347337 AB |
553 | int status; |
554 | ||
c077881a HZ |
555 | linux_disable_event_reporting (child_pid); |
556 | if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0) | |
557 | perror_with_name (_("Couldn't do single step")); | |
558 | if (my_waitpid (child_pid, &status, 0) < 0) | |
559 | perror_with_name (_("Couldn't wait vfork process")); | |
95347337 AB |
560 | else |
561 | { | |
562 | detach_child = WIFSTOPPED (status); | |
563 | child_stop_signal = WSTOPSIG (status); | |
564 | } | |
c077881a HZ |
565 | } |
566 | ||
95347337 | 567 | if (detach_child) |
9caaaa83 | 568 | { |
95347337 | 569 | int signo = child_stop_signal; |
9caaaa83 | 570 | |
9caaaa83 PA |
571 | if (signo != 0 |
572 | && !signal_pass_state (gdb_signal_from_host (signo))) | |
573 | signo = 0; | |
574 | ptrace (PTRACE_DETACH, child_pid, 0, signo); | |
8a89ddbd PA |
575 | |
576 | close_proc_mem_file (child_pid); | |
9caaaa83 | 577 | } |
ac264b3b | 578 | } |
9016a515 DJ |
579 | |
580 | if (has_vforked) | |
581 | { | |
a2885186 SM |
582 | lwp_info *parent_lp = find_lwp_pid (parent_ptid); |
583 | linux_nat_debug_printf ("waiting for VFORK_DONE on %d", parent_pid); | |
584 | parent_lp->stopped = 1; | |
6c95b8df | 585 | |
a2885186 SM |
586 | /* We'll handle the VFORK_DONE event like any other |
587 | event, in target_wait. */ | |
9016a515 | 588 | } |
4de4c07c | 589 | } |
3993f6b1 | 590 | else |
4de4c07c | 591 | { |
3ced3da4 | 592 | struct lwp_info *child_lp; |
4de4c07c | 593 | |
82d1f134 | 594 | child_lp = add_lwp (child_ptid); |
3ced3da4 | 595 | child_lp->stopped = 1; |
25289eb2 | 596 | child_lp->last_resume_kind = resume_stop; |
4de4c07c | 597 | } |
4de4c07c DJ |
598 | } |
599 | ||
4de4c07c | 600 | \f |
f6ac5f3d PA |
601 | int |
602 | linux_nat_target::insert_fork_catchpoint (int pid) | |
4de4c07c | 603 | { |
a2885186 | 604 | return 0; |
3993f6b1 DJ |
605 | } |
606 | ||
f6ac5f3d PA |
607 | int |
608 | linux_nat_target::remove_fork_catchpoint (int pid) | |
eb73ad13 PA |
609 | { |
610 | return 0; | |
611 | } | |
612 | ||
f6ac5f3d PA |
613 | int |
614 | linux_nat_target::insert_vfork_catchpoint (int pid) | |
3993f6b1 | 615 | { |
a2885186 | 616 | return 0; |
3993f6b1 DJ |
617 | } |
618 | ||
f6ac5f3d PA |
619 | int |
620 | linux_nat_target::remove_vfork_catchpoint (int pid) | |
eb73ad13 PA |
621 | { |
622 | return 0; | |
623 | } | |
624 | ||
f6ac5f3d PA |
625 | int |
626 | linux_nat_target::insert_exec_catchpoint (int pid) | |
3993f6b1 | 627 | { |
a2885186 | 628 | return 0; |
3993f6b1 DJ |
629 | } |
630 | ||
f6ac5f3d PA |
631 | int |
632 | linux_nat_target::remove_exec_catchpoint (int pid) | |
eb73ad13 PA |
633 | { |
634 | return 0; | |
635 | } | |
636 | ||
f6ac5f3d PA |
637 | int |
638 | linux_nat_target::set_syscall_catchpoint (int pid, bool needed, int any_count, | |
639 | gdb::array_view<const int> syscall_counts) | |
a96d9b2e | 640 | { |
a96d9b2e SDJ |
641 | /* On GNU/Linux, we ignore the arguments. It means that we only |
642 | enable the syscall catchpoints, but do not disable them. | |
77b06cd7 | 643 | |
649a140c | 644 | Also, we do not use the `syscall_counts' information because we do not |
a96d9b2e SDJ |
645 | filter system calls here. We let GDB do the logic for us. */ |
646 | return 0; | |
647 | } | |
648 | ||
774113b0 PA |
649 | /* List of known LWPs, keyed by LWP PID. This speeds up the common |
650 | case of mapping a PID returned from the kernel to our corresponding | |
651 | lwp_info data structure. */ | |
652 | static htab_t lwp_lwpid_htab; | |
653 | ||
654 | /* Calculate a hash from a lwp_info's LWP PID. */ | |
655 | ||
656 | static hashval_t | |
657 | lwp_info_hash (const void *ap) | |
658 | { | |
659 | const struct lwp_info *lp = (struct lwp_info *) ap; | |
e38504b3 | 660 | pid_t pid = lp->ptid.lwp (); |
774113b0 PA |
661 | |
662 | return iterative_hash_object (pid, 0); | |
663 | } | |
664 | ||
665 | /* Equality function for the lwp_info hash table. Compares the LWP's | |
666 | PID. */ | |
667 | ||
668 | static int | |
669 | lwp_lwpid_htab_eq (const void *a, const void *b) | |
670 | { | |
671 | const struct lwp_info *entry = (const struct lwp_info *) a; | |
672 | const struct lwp_info *element = (const struct lwp_info *) b; | |
673 | ||
e38504b3 | 674 | return entry->ptid.lwp () == element->ptid.lwp (); |
774113b0 PA |
675 | } |
676 | ||
677 | /* Create the lwp_lwpid_htab hash table. */ | |
678 | ||
679 | static void | |
680 | lwp_lwpid_htab_create (void) | |
681 | { | |
682 | lwp_lwpid_htab = htab_create (100, lwp_info_hash, lwp_lwpid_htab_eq, NULL); | |
683 | } | |
684 | ||
685 | /* Add LP to the hash table. */ | |
686 | ||
687 | static void | |
688 | lwp_lwpid_htab_add_lwp (struct lwp_info *lp) | |
689 | { | |
690 | void **slot; | |
691 | ||
692 | slot = htab_find_slot (lwp_lwpid_htab, lp, INSERT); | |
693 | gdb_assert (slot != NULL && *slot == NULL); | |
694 | *slot = lp; | |
695 | } | |
696 | ||
697 | /* Head of doubly-linked list of known LWPs. Sorted by reverse | |
698 | creation order. This order is assumed in some cases. E.g., | |
699 | reaping status after killing alls lwps of a process: the leader LWP | |
700 | must be reaped last. */ | |
901b9821 SM |
701 | |
702 | static intrusive_list<lwp_info> lwp_list; | |
703 | ||
704 | /* See linux-nat.h. */ | |
705 | ||
706 | lwp_info_range | |
707 | all_lwps () | |
708 | { | |
709 | return lwp_info_range (lwp_list.begin ()); | |
710 | } | |
711 | ||
712 | /* See linux-nat.h. */ | |
713 | ||
714 | lwp_info_safe_range | |
715 | all_lwps_safe () | |
716 | { | |
717 | return lwp_info_safe_range (lwp_list.begin ()); | |
718 | } | |
774113b0 PA |
719 | |
720 | /* Add LP to sorted-by-reverse-creation-order doubly-linked list. */ | |
721 | ||
722 | static void | |
723 | lwp_list_add (struct lwp_info *lp) | |
724 | { | |
901b9821 | 725 | lwp_list.push_front (*lp); |
774113b0 PA |
726 | } |
727 | ||
728 | /* Remove LP from sorted-by-reverse-creation-order doubly-linked | |
729 | list. */ | |
730 | ||
731 | static void | |
732 | lwp_list_remove (struct lwp_info *lp) | |
733 | { | |
734 | /* Remove from sorted-by-creation-order list. */ | |
901b9821 | 735 | lwp_list.erase (lwp_list.iterator_to (*lp)); |
774113b0 PA |
736 | } |
737 | ||
d6b0e80f AC |
738 | \f |
739 | ||
d6b0e80f AC |
740 | /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in |
741 | _initialize_linux_nat. */ | |
742 | static sigset_t suspend_mask; | |
743 | ||
7feb7d06 PA |
744 | /* Signals to block to make that sigsuspend work. */ |
745 | static sigset_t blocked_mask; | |
746 | ||
747 | /* SIGCHLD action. */ | |
6bd434d6 | 748 | static struct sigaction sigchld_action; |
b84876c2 | 749 | |
7feb7d06 PA |
750 | /* Block child signals (SIGCHLD and linux threads signals), and store |
751 | the previous mask in PREV_MASK. */ | |
84e46146 | 752 | |
7feb7d06 PA |
753 | static void |
754 | block_child_signals (sigset_t *prev_mask) | |
755 | { | |
756 | /* Make sure SIGCHLD is blocked. */ | |
757 | if (!sigismember (&blocked_mask, SIGCHLD)) | |
758 | sigaddset (&blocked_mask, SIGCHLD); | |
759 | ||
21987b9c | 760 | gdb_sigmask (SIG_BLOCK, &blocked_mask, prev_mask); |
7feb7d06 PA |
761 | } |
762 | ||
763 | /* Restore child signals mask, previously returned by | |
764 | block_child_signals. */ | |
765 | ||
766 | static void | |
767 | restore_child_signals_mask (sigset_t *prev_mask) | |
768 | { | |
21987b9c | 769 | gdb_sigmask (SIG_SETMASK, prev_mask, NULL); |
7feb7d06 | 770 | } |
2455069d UW |
771 | |
772 | /* Mask of signals to pass directly to the inferior. */ | |
773 | static sigset_t pass_mask; | |
774 | ||
775 | /* Update signals to pass to the inferior. */ | |
f6ac5f3d | 776 | void |
adc6a863 PA |
777 | linux_nat_target::pass_signals |
778 | (gdb::array_view<const unsigned char> pass_signals) | |
2455069d UW |
779 | { |
780 | int signo; | |
781 | ||
782 | sigemptyset (&pass_mask); | |
783 | ||
784 | for (signo = 1; signo < NSIG; signo++) | |
785 | { | |
2ea28649 | 786 | int target_signo = gdb_signal_from_host (signo); |
adc6a863 | 787 | if (target_signo < pass_signals.size () && pass_signals[target_signo]) |
dda83cd7 | 788 | sigaddset (&pass_mask, signo); |
2455069d UW |
789 | } |
790 | } | |
791 | ||
d6b0e80f AC |
792 | \f |
793 | ||
794 | /* Prototypes for local functions. */ | |
d3a70e03 TT |
795 | static int stop_wait_callback (struct lwp_info *lp); |
796 | static int resume_stopped_resumed_lwps (struct lwp_info *lp, const ptid_t wait_ptid); | |
ced2dffb | 797 | static int check_ptrace_stopped_lwp_gone (struct lwp_info *lp); |
710151dd | 798 | |
d6b0e80f | 799 | \f |
d6b0e80f | 800 | |
7b50312a PA |
801 | /* Destroy and free LP. */ |
802 | ||
676362df | 803 | lwp_info::~lwp_info () |
7b50312a | 804 | { |
466eecee | 805 | /* Let the arch specific bits release arch_lwp_info. */ |
676362df | 806 | linux_target->low_delete_thread (this->arch_private); |
7b50312a PA |
807 | } |
808 | ||
774113b0 | 809 | /* Traversal function for purge_lwp_list. */ |
d90e17a7 | 810 | |
774113b0 PA |
811 | static int |
812 | lwp_lwpid_htab_remove_pid (void **slot, void *info) | |
d90e17a7 | 813 | { |
774113b0 PA |
814 | struct lwp_info *lp = (struct lwp_info *) *slot; |
815 | int pid = *(int *) info; | |
d90e17a7 | 816 | |
e99b03dc | 817 | if (lp->ptid.pid () == pid) |
d90e17a7 | 818 | { |
774113b0 PA |
819 | htab_clear_slot (lwp_lwpid_htab, slot); |
820 | lwp_list_remove (lp); | |
676362df | 821 | delete lp; |
774113b0 | 822 | } |
d90e17a7 | 823 | |
774113b0 PA |
824 | return 1; |
825 | } | |
d90e17a7 | 826 | |
774113b0 PA |
827 | /* Remove all LWPs belong to PID from the lwp list. */ |
828 | ||
829 | static void | |
830 | purge_lwp_list (int pid) | |
831 | { | |
832 | htab_traverse_noresize (lwp_lwpid_htab, lwp_lwpid_htab_remove_pid, &pid); | |
d90e17a7 PA |
833 | } |
834 | ||
26cb8b7c PA |
835 | /* Add the LWP specified by PTID to the list. PTID is the first LWP |
836 | in the process. Return a pointer to the structure describing the | |
837 | new LWP. | |
838 | ||
839 | This differs from add_lwp in that we don't let the arch specific | |
840 | bits know about this new thread. Current clients of this callback | |
841 | take the opportunity to install watchpoints in the new thread, and | |
842 | we shouldn't do that for the first thread. If we're spawning a | |
843 | child ("run"), the thread executes the shell wrapper first, and we | |
844 | shouldn't touch it until it execs the program we want to debug. | |
845 | For "attach", it'd be okay to call the callback, but it's not | |
846 | necessary, because watchpoints can't yet have been inserted into | |
847 | the inferior. */ | |
d6b0e80f AC |
848 | |
849 | static struct lwp_info * | |
26cb8b7c | 850 | add_initial_lwp (ptid_t ptid) |
d6b0e80f | 851 | { |
15a9e13e | 852 | gdb_assert (ptid.lwp_p ()); |
d6b0e80f | 853 | |
b0f6c8d2 | 854 | lwp_info *lp = new lwp_info (ptid); |
d6b0e80f | 855 | |
d6b0e80f | 856 | |
774113b0 PA |
857 | /* Add to sorted-by-reverse-creation-order list. */ |
858 | lwp_list_add (lp); | |
859 | ||
860 | /* Add to keyed-by-pid htab. */ | |
861 | lwp_lwpid_htab_add_lwp (lp); | |
d6b0e80f | 862 | |
26cb8b7c PA |
863 | return lp; |
864 | } | |
865 | ||
866 | /* Add the LWP specified by PID to the list. Return a pointer to the | |
867 | structure describing the new LWP. The LWP should already be | |
868 | stopped. */ | |
869 | ||
870 | static struct lwp_info * | |
871 | add_lwp (ptid_t ptid) | |
872 | { | |
873 | struct lwp_info *lp; | |
874 | ||
875 | lp = add_initial_lwp (ptid); | |
876 | ||
6e012a6c PA |
877 | /* Let the arch specific bits know about this new thread. Current |
878 | clients of this callback take the opportunity to install | |
26cb8b7c PA |
879 | watchpoints in the new thread. We don't do this for the first |
880 | thread though. See add_initial_lwp. */ | |
135340af | 881 | linux_target->low_new_thread (lp); |
9f0bdab8 | 882 | |
d6b0e80f AC |
883 | return lp; |
884 | } | |
885 | ||
886 | /* Remove the LWP specified by PID from the list. */ | |
887 | ||
888 | static void | |
889 | delete_lwp (ptid_t ptid) | |
890 | { | |
b0f6c8d2 | 891 | lwp_info dummy (ptid); |
d6b0e80f | 892 | |
b0f6c8d2 | 893 | void **slot = htab_find_slot (lwp_lwpid_htab, &dummy, NO_INSERT); |
774113b0 PA |
894 | if (slot == NULL) |
895 | return; | |
d6b0e80f | 896 | |
b0f6c8d2 | 897 | lwp_info *lp = *(struct lwp_info **) slot; |
774113b0 | 898 | gdb_assert (lp != NULL); |
d6b0e80f | 899 | |
774113b0 | 900 | htab_clear_slot (lwp_lwpid_htab, slot); |
d6b0e80f | 901 | |
774113b0 PA |
902 | /* Remove from sorted-by-creation-order list. */ |
903 | lwp_list_remove (lp); | |
d6b0e80f | 904 | |
774113b0 | 905 | /* Release. */ |
676362df | 906 | delete lp; |
d6b0e80f AC |
907 | } |
908 | ||
909 | /* Return a pointer to the structure describing the LWP corresponding | |
910 | to PID. If no corresponding LWP could be found, return NULL. */ | |
911 | ||
912 | static struct lwp_info * | |
913 | find_lwp_pid (ptid_t ptid) | |
914 | { | |
d6b0e80f AC |
915 | int lwp; |
916 | ||
15a9e13e | 917 | if (ptid.lwp_p ()) |
e38504b3 | 918 | lwp = ptid.lwp (); |
d6b0e80f | 919 | else |
e99b03dc | 920 | lwp = ptid.pid (); |
d6b0e80f | 921 | |
b0f6c8d2 SM |
922 | lwp_info dummy (ptid_t (0, lwp)); |
923 | return (struct lwp_info *) htab_find (lwp_lwpid_htab, &dummy); | |
d6b0e80f AC |
924 | } |
925 | ||
6d4ee8c6 | 926 | /* See nat/linux-nat.h. */ |
d6b0e80f AC |
927 | |
928 | struct lwp_info * | |
d90e17a7 | 929 | iterate_over_lwps (ptid_t filter, |
d3a70e03 | 930 | gdb::function_view<iterate_over_lwps_ftype> callback) |
d6b0e80f | 931 | { |
901b9821 | 932 | for (lwp_info *lp : all_lwps_safe ()) |
d6b0e80f | 933 | { |
26a57c92 | 934 | if (lp->ptid.matches (filter)) |
d90e17a7 | 935 | { |
d3a70e03 | 936 | if (callback (lp) != 0) |
d90e17a7 PA |
937 | return lp; |
938 | } | |
d6b0e80f AC |
939 | } |
940 | ||
941 | return NULL; | |
942 | } | |
943 | ||
2277426b PA |
944 | /* Update our internal state when changing from one checkpoint to |
945 | another indicated by NEW_PTID. We can only switch single-threaded | |
946 | applications, so we only create one new LWP, and the previous list | |
947 | is discarded. */ | |
f973ed9c DJ |
948 | |
949 | void | |
950 | linux_nat_switch_fork (ptid_t new_ptid) | |
951 | { | |
952 | struct lwp_info *lp; | |
953 | ||
e99b03dc | 954 | purge_lwp_list (inferior_ptid.pid ()); |
2277426b | 955 | |
f973ed9c DJ |
956 | lp = add_lwp (new_ptid); |
957 | lp->stopped = 1; | |
e26af52f | 958 | |
2277426b PA |
959 | /* This changes the thread's ptid while preserving the gdb thread |
960 | num. Also changes the inferior pid, while preserving the | |
961 | inferior num. */ | |
5b6d1e4f | 962 | thread_change_ptid (linux_target, inferior_ptid, new_ptid); |
2277426b PA |
963 | |
964 | /* We've just told GDB core that the thread changed target id, but, | |
965 | in fact, it really is a different thread, with different register | |
966 | contents. */ | |
967 | registers_changed (); | |
e26af52f DJ |
968 | } |
969 | ||
7730e5c6 PA |
970 | /* Handle the exit of a single thread LP. If DEL_THREAD is true, |
971 | delete the thread_info associated to LP, if it exists. */ | |
e26af52f DJ |
972 | |
973 | static void | |
7730e5c6 | 974 | exit_lwp (struct lwp_info *lp, bool del_thread = true) |
e26af52f | 975 | { |
9213a6d7 | 976 | struct thread_info *th = linux_target->find_thread (lp->ptid); |
063bfe2e | 977 | |
7730e5c6 | 978 | if (th != nullptr && del_thread) |
9d7d58e7 | 979 | delete_thread (th); |
e26af52f DJ |
980 | |
981 | delete_lwp (lp->ptid); | |
982 | } | |
983 | ||
a0ef4274 DJ |
984 | /* Wait for the LWP specified by LP, which we have just attached to. |
985 | Returns a wait status for that LWP, to cache. */ | |
986 | ||
987 | static int | |
22827c51 | 988 | linux_nat_post_attach_wait (ptid_t ptid, int *signalled) |
a0ef4274 | 989 | { |
e38504b3 | 990 | pid_t new_pid, pid = ptid.lwp (); |
a0ef4274 DJ |
991 | int status; |
992 | ||
644cebc9 | 993 | if (linux_proc_pid_is_stopped (pid)) |
a0ef4274 | 994 | { |
9327494e | 995 | linux_nat_debug_printf ("Attaching to a stopped process"); |
a0ef4274 DJ |
996 | |
997 | /* The process is definitely stopped. It is in a job control | |
998 | stop, unless the kernel predates the TASK_STOPPED / | |
999 | TASK_TRACED distinction, in which case it might be in a | |
1000 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
1001 | can kill it, signal it, et cetera. | |
1002 | ||
dda83cd7 | 1003 | First make sure there is a pending SIGSTOP. Since we are |
a0ef4274 DJ |
1004 | already attached, the process can not transition from stopped |
1005 | to running without a PTRACE_CONT; so we know this signal will | |
1006 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
1007 | probably already in the queue (unless this kernel is old | |
1008 | enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP | |
1009 | is not an RT signal, it can only be queued once. */ | |
1010 | kill_lwp (pid, SIGSTOP); | |
1011 | ||
1012 | /* Finally, resume the stopped process. This will deliver the SIGSTOP | |
1013 | (or a higher priority signal, just like normal PTRACE_ATTACH). */ | |
1014 | ptrace (PTRACE_CONT, pid, 0, 0); | |
1015 | } | |
1016 | ||
1017 | /* Make sure the initial process is stopped. The user-level threads | |
1018 | layer might want to poke around in the inferior, and that won't | |
1019 | work if things haven't stabilized yet. */ | |
4a6ed09b | 1020 | new_pid = my_waitpid (pid, &status, __WALL); |
dacc9cb2 PP |
1021 | gdb_assert (pid == new_pid); |
1022 | ||
1023 | if (!WIFSTOPPED (status)) | |
1024 | { | |
1025 | /* The pid we tried to attach has apparently just exited. */ | |
9327494e | 1026 | linux_nat_debug_printf ("Failed to stop %d: %s", pid, |
8d06918f | 1027 | status_to_str (status).c_str ()); |
dacc9cb2 PP |
1028 | return status; |
1029 | } | |
a0ef4274 DJ |
1030 | |
1031 | if (WSTOPSIG (status) != SIGSTOP) | |
1032 | { | |
1033 | *signalled = 1; | |
9327494e | 1034 | linux_nat_debug_printf ("Received %s after attaching", |
8d06918f | 1035 | status_to_str (status).c_str ()); |
a0ef4274 DJ |
1036 | } |
1037 | ||
1038 | return status; | |
1039 | } | |
1040 | ||
f6ac5f3d PA |
1041 | void |
1042 | linux_nat_target::create_inferior (const char *exec_file, | |
1043 | const std::string &allargs, | |
1044 | char **env, int from_tty) | |
b84876c2 | 1045 | { |
41272101 TT |
1046 | maybe_disable_address_space_randomization restore_personality |
1047 | (disable_randomization); | |
b84876c2 PA |
1048 | |
1049 | /* The fork_child mechanism is synchronous and calls target_wait, so | |
1050 | we have to mask the async mode. */ | |
1051 | ||
2455069d | 1052 | /* Make sure we report all signals during startup. */ |
adc6a863 | 1053 | pass_signals ({}); |
2455069d | 1054 | |
f6ac5f3d | 1055 | inf_ptrace_target::create_inferior (exec_file, allargs, env, from_tty); |
8a89ddbd PA |
1056 | |
1057 | open_proc_mem_file (inferior_ptid); | |
b84876c2 PA |
1058 | } |
1059 | ||
8784d563 PA |
1060 | /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not |
1061 | already attached. Returns true if a new LWP is found, false | |
1062 | otherwise. */ | |
1063 | ||
1064 | static int | |
1065 | attach_proc_task_lwp_callback (ptid_t ptid) | |
1066 | { | |
1067 | struct lwp_info *lp; | |
1068 | ||
1069 | /* Ignore LWPs we're already attached to. */ | |
1070 | lp = find_lwp_pid (ptid); | |
1071 | if (lp == NULL) | |
1072 | { | |
e38504b3 | 1073 | int lwpid = ptid.lwp (); |
8784d563 PA |
1074 | |
1075 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) | |
1076 | { | |
1077 | int err = errno; | |
1078 | ||
1079 | /* Be quiet if we simply raced with the thread exiting. | |
1080 | EPERM is returned if the thread's task still exists, and | |
1081 | is marked as exited or zombie, as well as other | |
1082 | conditions, so in that case, confirm the status in | |
1083 | /proc/PID/status. */ | |
1084 | if (err == ESRCH | |
1085 | || (err == EPERM && linux_proc_pid_is_gone (lwpid))) | |
1086 | { | |
9327494e SM |
1087 | linux_nat_debug_printf |
1088 | ("Cannot attach to lwp %d: thread is gone (%d: %s)", | |
1089 | lwpid, err, safe_strerror (err)); | |
1090 | ||
8784d563 PA |
1091 | } |
1092 | else | |
1093 | { | |
4d9b86e1 | 1094 | std::string reason |
50fa3001 | 1095 | = linux_ptrace_attach_fail_reason_string (ptid, err); |
4d9b86e1 | 1096 | |
c6f7f9c8 TT |
1097 | error (_("Cannot attach to lwp %d: %s"), |
1098 | lwpid, reason.c_str ()); | |
8784d563 PA |
1099 | } |
1100 | } | |
1101 | else | |
1102 | { | |
9327494e | 1103 | linux_nat_debug_printf ("PTRACE_ATTACH %s, 0, 0 (OK)", |
e53c95d4 | 1104 | ptid.to_string ().c_str ()); |
8784d563 PA |
1105 | |
1106 | lp = add_lwp (ptid); | |
8784d563 PA |
1107 | |
1108 | /* The next time we wait for this LWP we'll see a SIGSTOP as | |
1109 | PTRACE_ATTACH brings it to a halt. */ | |
1110 | lp->signalled = 1; | |
1111 | ||
1112 | /* We need to wait for a stop before being able to make the | |
1113 | next ptrace call on this LWP. */ | |
1114 | lp->must_set_ptrace_flags = 1; | |
026a9174 PA |
1115 | |
1116 | /* So that wait collects the SIGSTOP. */ | |
1117 | lp->resumed = 1; | |
8784d563 PA |
1118 | } |
1119 | ||
1120 | return 1; | |
1121 | } | |
1122 | return 0; | |
1123 | } | |
1124 | ||
f6ac5f3d PA |
1125 | void |
1126 | linux_nat_target::attach (const char *args, int from_tty) | |
d6b0e80f AC |
1127 | { |
1128 | struct lwp_info *lp; | |
d6b0e80f | 1129 | int status; |
af990527 | 1130 | ptid_t ptid; |
d6b0e80f | 1131 | |
2455069d | 1132 | /* Make sure we report all signals during attach. */ |
adc6a863 | 1133 | pass_signals ({}); |
2455069d | 1134 | |
a70b8144 | 1135 | try |
87b0bb13 | 1136 | { |
f6ac5f3d | 1137 | inf_ptrace_target::attach (args, from_tty); |
87b0bb13 | 1138 | } |
230d2906 | 1139 | catch (const gdb_exception_error &ex) |
87b0bb13 JK |
1140 | { |
1141 | pid_t pid = parse_pid_to_attach (args); | |
50fa3001 | 1142 | std::string reason = linux_ptrace_attach_fail_reason (pid); |
87b0bb13 | 1143 | |
4d9b86e1 | 1144 | if (!reason.empty ()) |
3d6e9d23 TT |
1145 | throw_error (ex.error, "warning: %s\n%s", reason.c_str (), |
1146 | ex.what ()); | |
7ae1a6a6 | 1147 | else |
3d6e9d23 | 1148 | throw_error (ex.error, "%s", ex.what ()); |
87b0bb13 | 1149 | } |
d6b0e80f | 1150 | |
af990527 PA |
1151 | /* The ptrace base target adds the main thread with (pid,0,0) |
1152 | format. Decorate it with lwp info. */ | |
e99b03dc | 1153 | ptid = ptid_t (inferior_ptid.pid (), |
184ea2f7 | 1154 | inferior_ptid.pid ()); |
5b6d1e4f | 1155 | thread_change_ptid (linux_target, inferior_ptid, ptid); |
af990527 | 1156 | |
9f0bdab8 | 1157 | /* Add the initial process as the first LWP to the list. */ |
26cb8b7c | 1158 | lp = add_initial_lwp (ptid); |
a0ef4274 | 1159 | |
22827c51 | 1160 | status = linux_nat_post_attach_wait (lp->ptid, &lp->signalled); |
dacc9cb2 PP |
1161 | if (!WIFSTOPPED (status)) |
1162 | { | |
1163 | if (WIFEXITED (status)) | |
1164 | { | |
1165 | int exit_code = WEXITSTATUS (status); | |
1166 | ||
223ffa71 | 1167 | target_terminal::ours (); |
bc1e6c81 | 1168 | target_mourn_inferior (inferior_ptid); |
dacc9cb2 PP |
1169 | if (exit_code == 0) |
1170 | error (_("Unable to attach: program exited normally.")); | |
1171 | else | |
1172 | error (_("Unable to attach: program exited with code %d."), | |
1173 | exit_code); | |
1174 | } | |
1175 | else if (WIFSIGNALED (status)) | |
1176 | { | |
2ea28649 | 1177 | enum gdb_signal signo; |
dacc9cb2 | 1178 | |
223ffa71 | 1179 | target_terminal::ours (); |
bc1e6c81 | 1180 | target_mourn_inferior (inferior_ptid); |
dacc9cb2 | 1181 | |
2ea28649 | 1182 | signo = gdb_signal_from_host (WTERMSIG (status)); |
dacc9cb2 PP |
1183 | error (_("Unable to attach: program terminated with signal " |
1184 | "%s, %s."), | |
2ea28649 PA |
1185 | gdb_signal_to_name (signo), |
1186 | gdb_signal_to_string (signo)); | |
dacc9cb2 PP |
1187 | } |
1188 | ||
f34652de | 1189 | internal_error (_("unexpected status %d for PID %ld"), |
e38504b3 | 1190 | status, (long) ptid.lwp ()); |
dacc9cb2 PP |
1191 | } |
1192 | ||
a0ef4274 | 1193 | lp->stopped = 1; |
9f0bdab8 | 1194 | |
8a89ddbd PA |
1195 | open_proc_mem_file (lp->ptid); |
1196 | ||
a0ef4274 | 1197 | /* Save the wait status to report later. */ |
d6b0e80f | 1198 | lp->resumed = 1; |
9327494e | 1199 | linux_nat_debug_printf ("waitpid %ld, saving status %s", |
8d06918f SM |
1200 | (long) lp->ptid.pid (), |
1201 | status_to_str (status).c_str ()); | |
710151dd | 1202 | |
7feb7d06 PA |
1203 | lp->status = status; |
1204 | ||
8784d563 PA |
1205 | /* We must attach to every LWP. If /proc is mounted, use that to |
1206 | find them now. The inferior may be using raw clone instead of | |
1207 | using pthreads. But even if it is using pthreads, thread_db | |
1208 | walks structures in the inferior's address space to find the list | |
1209 | of threads/LWPs, and those structures may well be corrupted. | |
1210 | Note that once thread_db is loaded, we'll still use it to list | |
1211 | threads and associate pthread info with each LWP. */ | |
c6f7f9c8 TT |
1212 | try |
1213 | { | |
1214 | linux_proc_attach_tgid_threads (lp->ptid.pid (), | |
1215 | attach_proc_task_lwp_callback); | |
1216 | } | |
1217 | catch (const gdb_exception_error &) | |
1218 | { | |
1219 | /* Failed to attach to some LWP. Detach any we've already | |
1220 | attached to. */ | |
1221 | iterate_over_lwps (ptid_t (ptid.pid ()), | |
1222 | [] (struct lwp_info *lwp) -> int | |
1223 | { | |
1224 | /* Ignore errors when detaching. */ | |
1225 | ptrace (PTRACE_DETACH, lwp->ptid.lwp (), 0, 0); | |
1226 | delete_lwp (lwp->ptid); | |
1227 | return 0; | |
1228 | }); | |
1229 | ||
1230 | target_terminal::ours (); | |
1231 | target_mourn_inferior (inferior_ptid); | |
1232 | ||
1233 | throw; | |
1234 | } | |
1235 | ||
1236 | /* Add all the LWPs to gdb's thread list. */ | |
1237 | iterate_over_lwps (ptid_t (ptid.pid ()), | |
1238 | [] (struct lwp_info *lwp) -> int | |
1239 | { | |
1240 | if (lwp->ptid.pid () != lwp->ptid.lwp ()) | |
1241 | { | |
1242 | add_thread (linux_target, lwp->ptid); | |
1243 | set_running (linux_target, lwp->ptid, true); | |
1244 | set_executing (linux_target, lwp->ptid, true); | |
1245 | } | |
1246 | return 0; | |
1247 | }); | |
d6b0e80f AC |
1248 | } |
1249 | ||
4a3ee32a SM |
1250 | /* Ptrace-detach the thread with pid PID. */ |
1251 | ||
1252 | static void | |
1253 | detach_one_pid (int pid, int signo) | |
1254 | { | |
1255 | if (ptrace (PTRACE_DETACH, pid, 0, signo) < 0) | |
1256 | { | |
1257 | int save_errno = errno; | |
1258 | ||
1259 | /* We know the thread exists, so ESRCH must mean the lwp is | |
1260 | zombie. This can happen if one of the already-detached | |
1261 | threads exits the whole thread group. In that case we're | |
1262 | still attached, and must reap the lwp. */ | |
1263 | if (save_errno == ESRCH) | |
1264 | { | |
1265 | int ret, status; | |
1266 | ||
1267 | ret = my_waitpid (pid, &status, __WALL); | |
1268 | if (ret == -1) | |
1269 | { | |
1270 | warning (_("Couldn't reap LWP %d while detaching: %s"), | |
1271 | pid, safe_strerror (errno)); | |
1272 | } | |
1273 | else if (!WIFEXITED (status) && !WIFSIGNALED (status)) | |
1274 | { | |
1275 | warning (_("Reaping LWP %d while detaching " | |
1276 | "returned unexpected status 0x%x"), | |
1277 | pid, status); | |
1278 | } | |
1279 | } | |
1280 | else | |
1281 | error (_("Can't detach %d: %s"), | |
1282 | pid, safe_strerror (save_errno)); | |
1283 | } | |
1284 | else | |
1285 | linux_nat_debug_printf ("PTRACE_DETACH (%d, %s, 0) (OK)", | |
1286 | pid, strsignal (signo)); | |
1287 | } | |
1288 | ||
ced2dffb PA |
1289 | /* Get pending signal of THREAD as a host signal number, for detaching |
1290 | purposes. This is the signal the thread last stopped for, which we | |
1291 | need to deliver to the thread when detaching, otherwise, it'd be | |
1292 | suppressed/lost. */ | |
1293 | ||
a0ef4274 | 1294 | static int |
ced2dffb | 1295 | get_detach_signal (struct lwp_info *lp) |
a0ef4274 | 1296 | { |
a493e3e2 | 1297 | enum gdb_signal signo = GDB_SIGNAL_0; |
ca2163eb PA |
1298 | |
1299 | /* If we paused threads momentarily, we may have stored pending | |
1300 | events in lp->status or lp->waitstatus (see stop_wait_callback), | |
1301 | and GDB core hasn't seen any signal for those threads. | |
1302 | Otherwise, the last signal reported to the core is found in the | |
1303 | thread object's stop_signal. | |
1304 | ||
1305 | There's a corner case that isn't handled here at present. Only | |
1306 | if the thread stopped with a TARGET_WAITKIND_STOPPED does | |
1307 | stop_signal make sense as a real signal to pass to the inferior. | |
1308 | Some catchpoint related events, like | |
1309 | TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set | |
a493e3e2 | 1310 | to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But, |
ca2163eb PA |
1311 | those traps are debug API (ptrace in our case) related and |
1312 | induced; the inferior wouldn't see them if it wasn't being | |
1313 | traced. Hence, we should never pass them to the inferior, even | |
1314 | when set to pass state. Since this corner case isn't handled by | |
1315 | infrun.c when proceeding with a signal, for consistency, neither | |
1316 | do we handle it here (or elsewhere in the file we check for | |
1317 | signal pass state). Normally SIGTRAP isn't set to pass state, so | |
1318 | this is really a corner case. */ | |
1319 | ||
183be222 | 1320 | if (lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE) |
a493e3e2 | 1321 | signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */ |
ca2163eb | 1322 | else if (lp->status) |
2ea28649 | 1323 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
00431a78 | 1324 | else |
ca2163eb | 1325 | { |
9213a6d7 | 1326 | thread_info *tp = linux_target->find_thread (lp->ptid); |
e0881a8e | 1327 | |
611841bb | 1328 | if (target_is_non_stop_p () && !tp->executing ()) |
ca2163eb | 1329 | { |
1edb66d8 | 1330 | if (tp->has_pending_waitstatus ()) |
df5ad102 SM |
1331 | { |
1332 | /* If the thread has a pending event, and it was stopped with a | |
287de656 | 1333 | signal, use that signal to resume it. If it has a pending |
df5ad102 SM |
1334 | event of another kind, it was not stopped with a signal, so |
1335 | resume it without a signal. */ | |
1336 | if (tp->pending_waitstatus ().kind () == TARGET_WAITKIND_STOPPED) | |
1337 | signo = tp->pending_waitstatus ().sig (); | |
1338 | else | |
1339 | signo = GDB_SIGNAL_0; | |
1340 | } | |
00431a78 | 1341 | else |
1edb66d8 | 1342 | signo = tp->stop_signal (); |
00431a78 PA |
1343 | } |
1344 | else if (!target_is_non_stop_p ()) | |
1345 | { | |
00431a78 | 1346 | ptid_t last_ptid; |
5b6d1e4f | 1347 | process_stratum_target *last_target; |
00431a78 | 1348 | |
5b6d1e4f | 1349 | get_last_target_status (&last_target, &last_ptid, nullptr); |
e0881a8e | 1350 | |
5b6d1e4f PA |
1351 | if (last_target == linux_target |
1352 | && lp->ptid.lwp () == last_ptid.lwp ()) | |
1edb66d8 | 1353 | signo = tp->stop_signal (); |
4c28f408 | 1354 | } |
ca2163eb | 1355 | } |
4c28f408 | 1356 | |
a493e3e2 | 1357 | if (signo == GDB_SIGNAL_0) |
ca2163eb | 1358 | { |
9327494e | 1359 | linux_nat_debug_printf ("lwp %s has no pending signal", |
e53c95d4 | 1360 | lp->ptid.to_string ().c_str ()); |
ca2163eb PA |
1361 | } |
1362 | else if (!signal_pass_state (signo)) | |
1363 | { | |
9327494e SM |
1364 | linux_nat_debug_printf |
1365 | ("lwp %s had signal %s but it is in no pass state", | |
e53c95d4 | 1366 | lp->ptid.to_string ().c_str (), gdb_signal_to_string (signo)); |
a0ef4274 | 1367 | } |
a0ef4274 | 1368 | else |
4c28f408 | 1369 | { |
9327494e | 1370 | linux_nat_debug_printf ("lwp %s has pending signal %s", |
e53c95d4 | 1371 | lp->ptid.to_string ().c_str (), |
9327494e | 1372 | gdb_signal_to_string (signo)); |
ced2dffb PA |
1373 | |
1374 | return gdb_signal_to_host (signo); | |
4c28f408 | 1375 | } |
a0ef4274 DJ |
1376 | |
1377 | return 0; | |
1378 | } | |
1379 | ||
0d36baa9 | 1380 | /* If LP has a pending fork/vfork/clone status, return it. */ |
ced2dffb | 1381 | |
6b09f134 | 1382 | static std::optional<target_waitstatus> |
0d36baa9 | 1383 | get_pending_child_status (lwp_info *lp) |
d6b0e80f | 1384 | { |
b26b06dd AB |
1385 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
1386 | ||
1387 | linux_nat_debug_printf ("lwp %s (stopped = %d)", | |
1388 | lp->ptid.to_string ().c_str (), lp->stopped); | |
1389 | ||
df5ad102 SM |
1390 | /* Check in lwp_info::status. */ |
1391 | if (WIFSTOPPED (lp->status) && linux_is_extended_waitstatus (lp->status)) | |
1392 | { | |
1393 | int event = linux_ptrace_get_extended_event (lp->status); | |
1394 | ||
0d36baa9 PA |
1395 | if (event == PTRACE_EVENT_FORK |
1396 | || event == PTRACE_EVENT_VFORK | |
1397 | || event == PTRACE_EVENT_CLONE) | |
df5ad102 SM |
1398 | { |
1399 | unsigned long child_pid; | |
1400 | int ret = ptrace (PTRACE_GETEVENTMSG, lp->ptid.lwp (), 0, &child_pid); | |
1401 | if (ret == 0) | |
0d36baa9 PA |
1402 | { |
1403 | target_waitstatus ws; | |
1404 | ||
1405 | if (event == PTRACE_EVENT_FORK) | |
1406 | ws.set_forked (ptid_t (child_pid, child_pid)); | |
1407 | else if (event == PTRACE_EVENT_VFORK) | |
1408 | ws.set_vforked (ptid_t (child_pid, child_pid)); | |
1409 | else if (event == PTRACE_EVENT_CLONE) | |
1410 | ws.set_thread_cloned (ptid_t (lp->ptid.pid (), child_pid)); | |
1411 | else | |
1412 | gdb_assert_not_reached ("unhandled"); | |
1413 | ||
1414 | return ws; | |
1415 | } | |
df5ad102 | 1416 | else |
0d36baa9 PA |
1417 | { |
1418 | perror_warning_with_name (_("Failed to retrieve event msg")); | |
1419 | return {}; | |
1420 | } | |
df5ad102 SM |
1421 | } |
1422 | } | |
1423 | ||
1424 | /* Check in lwp_info::waitstatus. */ | |
0d36baa9 PA |
1425 | if (is_new_child_status (lp->waitstatus.kind ())) |
1426 | return lp->waitstatus; | |
df5ad102 | 1427 | |
9213a6d7 | 1428 | thread_info *tp = linux_target->find_thread (lp->ptid); |
df5ad102 | 1429 | |
0d36baa9 PA |
1430 | /* Check in thread_info::pending_waitstatus. */ |
1431 | if (tp->has_pending_waitstatus () | |
1432 | && is_new_child_status (tp->pending_waitstatus ().kind ())) | |
1433 | return tp->pending_waitstatus (); | |
df5ad102 SM |
1434 | |
1435 | /* Check in thread_info::pending_follow. */ | |
0d36baa9 PA |
1436 | if (is_new_child_status (tp->pending_follow.kind ())) |
1437 | return tp->pending_follow; | |
df5ad102 | 1438 | |
0d36baa9 PA |
1439 | return {}; |
1440 | } | |
1441 | ||
1442 | /* Detach from LP. If SIGNO_P is non-NULL, then it points to the | |
1443 | signal number that should be passed to the LWP when detaching. | |
1444 | Otherwise pass any pending signal the LWP may have, if any. */ | |
1445 | ||
1446 | static void | |
1447 | detach_one_lwp (struct lwp_info *lp, int *signo_p) | |
1448 | { | |
1449 | int lwpid = lp->ptid.lwp (); | |
1450 | int signo; | |
1451 | ||
1452 | /* If the lwp/thread we are about to detach has a pending fork/clone | |
1453 | event, there is a process/thread GDB is attached to that the core | |
1454 | of GDB doesn't know about. Detach from it. */ | |
1455 | ||
6b09f134 | 1456 | std::optional<target_waitstatus> ws = get_pending_child_status (lp); |
0d36baa9 PA |
1457 | if (ws.has_value ()) |
1458 | detach_one_pid (ws->child_ptid ().lwp (), 0); | |
d6b0e80f | 1459 | |
a0ef4274 DJ |
1460 | /* If there is a pending SIGSTOP, get rid of it. */ |
1461 | if (lp->signalled) | |
d6b0e80f | 1462 | { |
9327494e | 1463 | linux_nat_debug_printf ("Sending SIGCONT to %s", |
e53c95d4 | 1464 | lp->ptid.to_string ().c_str ()); |
d6b0e80f | 1465 | |
ced2dffb | 1466 | kill_lwp (lwpid, SIGCONT); |
d6b0e80f | 1467 | lp->signalled = 0; |
d6b0e80f AC |
1468 | } |
1469 | ||
57e6a098 KB |
1470 | /* If the lwp has exited or was terminated due to a signal, there's |
1471 | nothing left to do. */ | |
5e86aab8 | 1472 | if (is_lwp_marked_dead (lp)) |
57e6a098 KB |
1473 | { |
1474 | linux_nat_debug_printf | |
1475 | ("Can't detach %s - it has exited or was terminated: %s.", | |
1476 | lp->ptid.to_string ().c_str (), | |
1477 | lp->waitstatus.to_string ().c_str ()); | |
1478 | delete_lwp (lp->ptid); | |
1479 | return; | |
1480 | } | |
1481 | ||
ced2dffb | 1482 | if (signo_p == NULL) |
d6b0e80f | 1483 | { |
a0ef4274 | 1484 | /* Pass on any pending signal for this LWP. */ |
ced2dffb PA |
1485 | signo = get_detach_signal (lp); |
1486 | } | |
1487 | else | |
1488 | signo = *signo_p; | |
a0ef4274 | 1489 | |
b26b06dd AB |
1490 | linux_nat_debug_printf ("preparing to resume lwp %s (stopped = %d)", |
1491 | lp->ptid.to_string ().c_str (), | |
1492 | lp->stopped); | |
1493 | ||
ced2dffb PA |
1494 | /* Preparing to resume may try to write registers, and fail if the |
1495 | lwp is zombie. If that happens, ignore the error. We'll handle | |
1496 | it below, when detach fails with ESRCH. */ | |
a70b8144 | 1497 | try |
ced2dffb | 1498 | { |
135340af | 1499 | linux_target->low_prepare_to_resume (lp); |
ced2dffb | 1500 | } |
230d2906 | 1501 | catch (const gdb_exception_error &ex) |
ced2dffb PA |
1502 | { |
1503 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 1504 | throw; |
ced2dffb | 1505 | } |
d6b0e80f | 1506 | |
4a3ee32a | 1507 | detach_one_pid (lwpid, signo); |
ced2dffb PA |
1508 | |
1509 | delete_lwp (lp->ptid); | |
1510 | } | |
d6b0e80f | 1511 | |
ced2dffb | 1512 | static int |
d3a70e03 | 1513 | detach_callback (struct lwp_info *lp) |
ced2dffb PA |
1514 | { |
1515 | /* We don't actually detach from the thread group leader just yet. | |
1516 | If the thread group exits, we must reap the zombie clone lwps | |
1517 | before we're able to reap the leader. */ | |
e38504b3 | 1518 | if (lp->ptid.lwp () != lp->ptid.pid ()) |
ced2dffb | 1519 | detach_one_lwp (lp, NULL); |
d6b0e80f AC |
1520 | return 0; |
1521 | } | |
1522 | ||
f6ac5f3d PA |
1523 | void |
1524 | linux_nat_target::detach (inferior *inf, int from_tty) | |
d6b0e80f | 1525 | { |
b26b06dd AB |
1526 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
1527 | ||
d90e17a7 | 1528 | struct lwp_info *main_lwp; |
bc09b0c1 | 1529 | int pid = inf->pid; |
a0ef4274 | 1530 | |
ae5e0686 MK |
1531 | /* Don't unregister from the event loop, as there may be other |
1532 | inferiors running. */ | |
b84876c2 | 1533 | |
4c28f408 | 1534 | /* Stop all threads before detaching. ptrace requires that the |
30baf67b | 1535 | thread is stopped to successfully detach. */ |
d3a70e03 | 1536 | iterate_over_lwps (ptid_t (pid), stop_callback); |
4c28f408 PA |
1537 | /* ... and wait until all of them have reported back that |
1538 | they're no longer running. */ | |
d3a70e03 | 1539 | iterate_over_lwps (ptid_t (pid), stop_wait_callback); |
4c28f408 | 1540 | |
e87f0fe8 PA |
1541 | /* We can now safely remove breakpoints. We don't this in earlier |
1542 | in common code because this target doesn't currently support | |
1543 | writing memory while the inferior is running. */ | |
1544 | remove_breakpoints_inf (current_inferior ()); | |
1545 | ||
d3a70e03 | 1546 | iterate_over_lwps (ptid_t (pid), detach_callback); |
d6b0e80f | 1547 | |
fd492bf1 AB |
1548 | /* We have detached from everything except the main thread now, so |
1549 | should only have one thread left. However, in non-stop mode the | |
1550 | main thread might have exited, in which case we'll have no threads | |
1551 | left. */ | |
1552 | gdb_assert (num_lwps (pid) == 1 | |
1553 | || (target_is_non_stop_p () && num_lwps (pid) == 0)); | |
d6b0e80f | 1554 | |
57e6a098 | 1555 | if (pid == inferior_ptid.pid () && forks_exist_p ()) |
7a7d3353 PA |
1556 | { |
1557 | /* Multi-fork case. The current inferior_ptid is being detached | |
1558 | from, but there are other viable forks to debug. Detach from | |
1559 | the current fork, and context-switch to the first | |
1560 | available. */ | |
57e6a098 | 1561 | linux_fork_detach (from_tty, find_lwp_pid (ptid_t (pid))); |
7a7d3353 PA |
1562 | } |
1563 | else | |
ced2dffb | 1564 | { |
ced2dffb PA |
1565 | target_announce_detach (from_tty); |
1566 | ||
fd492bf1 AB |
1567 | /* In non-stop mode it is possible that the main thread has exited, |
1568 | in which case we don't try to detach. */ | |
1569 | main_lwp = find_lwp_pid (ptid_t (pid)); | |
1570 | if (main_lwp != nullptr) | |
1571 | { | |
1572 | /* Pass on any pending signal for the last LWP. */ | |
1573 | int signo = get_detach_signal (main_lwp); | |
ced2dffb | 1574 | |
fd492bf1 AB |
1575 | detach_one_lwp (main_lwp, &signo); |
1576 | } | |
1577 | else | |
1578 | gdb_assert (target_is_non_stop_p ()); | |
ced2dffb | 1579 | |
f6ac5f3d | 1580 | detach_success (inf); |
ced2dffb | 1581 | } |
05c06f31 | 1582 | |
8a89ddbd | 1583 | close_proc_mem_file (pid); |
d6b0e80f AC |
1584 | } |
1585 | ||
8a99810d PA |
1586 | /* Resume execution of the inferior process. If STEP is nonzero, |
1587 | single-step it. If SIGNAL is nonzero, give it that signal. */ | |
1588 | ||
1589 | static void | |
23f238d3 PA |
1590 | linux_resume_one_lwp_throw (struct lwp_info *lp, int step, |
1591 | enum gdb_signal signo) | |
8a99810d | 1592 | { |
8a99810d | 1593 | lp->step = step; |
9c02b525 PA |
1594 | |
1595 | /* stop_pc doubles as the PC the LWP had when it was last resumed. | |
1596 | We only presently need that if the LWP is stepped though (to | |
1597 | handle the case of stepping a breakpoint instruction). */ | |
1598 | if (step) | |
1599 | { | |
5b6d1e4f | 1600 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
9c02b525 PA |
1601 | |
1602 | lp->stop_pc = regcache_read_pc (regcache); | |
1603 | } | |
1604 | else | |
1605 | lp->stop_pc = 0; | |
1606 | ||
135340af | 1607 | linux_target->low_prepare_to_resume (lp); |
f6ac5f3d | 1608 | linux_target->low_resume (lp->ptid, step, signo); |
23f238d3 PA |
1609 | |
1610 | /* Successfully resumed. Clear state that no longer makes sense, | |
1611 | and mark the LWP as running. Must not do this before resuming | |
1612 | otherwise if that fails other code will be confused. E.g., we'd | |
1613 | later try to stop the LWP and hang forever waiting for a stop | |
1614 | status. Note that we must not throw after this is cleared, | |
1615 | otherwise handle_zombie_lwp_error would get confused. */ | |
8a99810d | 1616 | lp->stopped = 0; |
1ad3de98 | 1617 | lp->core = -1; |
23f238d3 | 1618 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; |
5b6d1e4f | 1619 | registers_changed_ptid (linux_target, lp->ptid); |
8a99810d PA |
1620 | } |
1621 | ||
23f238d3 PA |
1622 | /* Called when we try to resume a stopped LWP and that errors out. If |
1623 | the LWP is no longer in ptrace-stopped state (meaning it's zombie, | |
1624 | or about to become), discard the error, clear any pending status | |
1625 | the LWP may have, and return true (we'll collect the exit status | |
1626 | soon enough). Otherwise, return false. */ | |
1627 | ||
1628 | static int | |
1629 | check_ptrace_stopped_lwp_gone (struct lwp_info *lp) | |
1630 | { | |
1631 | /* If we get an error after resuming the LWP successfully, we'd | |
1632 | confuse !T state for the LWP being gone. */ | |
1633 | gdb_assert (lp->stopped); | |
1634 | ||
1635 | /* We can't just check whether the LWP is in 'Z (Zombie)' state, | |
1636 | because even if ptrace failed with ESRCH, the tracee may be "not | |
1637 | yet fully dead", but already refusing ptrace requests. In that | |
1638 | case the tracee has 'R (Running)' state for a little bit | |
1639 | (observed in Linux 3.18). See also the note on ESRCH in the | |
1640 | ptrace(2) man page. Instead, check whether the LWP has any state | |
1641 | other than ptrace-stopped. */ | |
1642 | ||
1643 | /* Don't assume anything if /proc/PID/status can't be read. */ | |
e38504b3 | 1644 | if (linux_proc_pid_is_trace_stopped_nowarn (lp->ptid.lwp ()) == 0) |
23f238d3 PA |
1645 | { |
1646 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; | |
1647 | lp->status = 0; | |
183be222 | 1648 | lp->waitstatus.set_ignore (); |
23f238d3 PA |
1649 | return 1; |
1650 | } | |
1651 | return 0; | |
1652 | } | |
1653 | ||
1654 | /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP | |
1655 | disappears while we try to resume it. */ | |
1656 | ||
1657 | static void | |
1658 | linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) | |
1659 | { | |
a70b8144 | 1660 | try |
23f238d3 PA |
1661 | { |
1662 | linux_resume_one_lwp_throw (lp, step, signo); | |
1663 | } | |
230d2906 | 1664 | catch (const gdb_exception_error &ex) |
23f238d3 PA |
1665 | { |
1666 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 1667 | throw; |
23f238d3 | 1668 | } |
23f238d3 PA |
1669 | } |
1670 | ||
d6b0e80f AC |
1671 | /* Resume LP. */ |
1672 | ||
25289eb2 | 1673 | static void |
e5ef252a | 1674 | resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) |
d6b0e80f | 1675 | { |
25289eb2 | 1676 | if (lp->stopped) |
6c95b8df | 1677 | { |
5b6d1e4f | 1678 | struct inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
25289eb2 PA |
1679 | |
1680 | if (inf->vfork_child != NULL) | |
1681 | { | |
8a9da63e | 1682 | linux_nat_debug_printf ("Not resuming sibling %s (vfork parent)", |
e53c95d4 | 1683 | lp->ptid.to_string ().c_str ()); |
25289eb2 | 1684 | } |
8a99810d | 1685 | else if (!lwp_status_pending_p (lp)) |
25289eb2 | 1686 | { |
9327494e | 1687 | linux_nat_debug_printf ("Resuming sibling %s, %s, %s", |
e53c95d4 | 1688 | lp->ptid.to_string ().c_str (), |
9327494e SM |
1689 | (signo != GDB_SIGNAL_0 |
1690 | ? strsignal (gdb_signal_to_host (signo)) | |
1691 | : "0"), | |
1692 | step ? "step" : "resume"); | |
25289eb2 | 1693 | |
8a99810d | 1694 | linux_resume_one_lwp (lp, step, signo); |
25289eb2 PA |
1695 | } |
1696 | else | |
1697 | { | |
9327494e | 1698 | linux_nat_debug_printf ("Not resuming sibling %s (has pending)", |
e53c95d4 | 1699 | lp->ptid.to_string ().c_str ()); |
25289eb2 | 1700 | } |
6c95b8df | 1701 | } |
25289eb2 | 1702 | else |
9327494e | 1703 | linux_nat_debug_printf ("Not resuming sibling %s (not stopped)", |
e53c95d4 | 1704 | lp->ptid.to_string ().c_str ()); |
25289eb2 | 1705 | } |
d6b0e80f | 1706 | |
8817a6f2 PA |
1707 | /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing. |
1708 | Resume LWP with the last stop signal, if it is in pass state. */ | |
e5ef252a | 1709 | |
25289eb2 | 1710 | static int |
d3a70e03 | 1711 | linux_nat_resume_callback (struct lwp_info *lp, struct lwp_info *except) |
25289eb2 | 1712 | { |
e5ef252a PA |
1713 | enum gdb_signal signo = GDB_SIGNAL_0; |
1714 | ||
8817a6f2 PA |
1715 | if (lp == except) |
1716 | return 0; | |
1717 | ||
e5ef252a PA |
1718 | if (lp->stopped) |
1719 | { | |
1720 | struct thread_info *thread; | |
1721 | ||
9213a6d7 | 1722 | thread = linux_target->find_thread (lp->ptid); |
e5ef252a PA |
1723 | if (thread != NULL) |
1724 | { | |
1edb66d8 SM |
1725 | signo = thread->stop_signal (); |
1726 | thread->set_stop_signal (GDB_SIGNAL_0); | |
e5ef252a PA |
1727 | } |
1728 | } | |
1729 | ||
1730 | resume_lwp (lp, 0, signo); | |
d6b0e80f AC |
1731 | return 0; |
1732 | } | |
1733 | ||
1734 | static int | |
d3a70e03 | 1735 | resume_clear_callback (struct lwp_info *lp) |
d6b0e80f AC |
1736 | { |
1737 | lp->resumed = 0; | |
25289eb2 | 1738 | lp->last_resume_kind = resume_stop; |
d6b0e80f AC |
1739 | return 0; |
1740 | } | |
1741 | ||
1742 | static int | |
d3a70e03 | 1743 | resume_set_callback (struct lwp_info *lp) |
d6b0e80f AC |
1744 | { |
1745 | lp->resumed = 1; | |
25289eb2 | 1746 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1747 | return 0; |
1748 | } | |
1749 | ||
f6ac5f3d | 1750 | void |
d51926f0 | 1751 | linux_nat_target::resume (ptid_t scope_ptid, int step, enum gdb_signal signo) |
d6b0e80f AC |
1752 | { |
1753 | struct lwp_info *lp; | |
d6b0e80f | 1754 | |
9327494e SM |
1755 | linux_nat_debug_printf ("Preparing to %s %s, %s, inferior_ptid %s", |
1756 | step ? "step" : "resume", | |
d51926f0 | 1757 | scope_ptid.to_string ().c_str (), |
9327494e SM |
1758 | (signo != GDB_SIGNAL_0 |
1759 | ? strsignal (gdb_signal_to_host (signo)) : "0"), | |
e53c95d4 | 1760 | inferior_ptid.to_string ().c_str ()); |
76f50ad1 | 1761 | |
7da6a5b9 LM |
1762 | /* Mark the lwps we're resuming as resumed and update their |
1763 | last_resume_kind to resume_continue. */ | |
d51926f0 | 1764 | iterate_over_lwps (scope_ptid, resume_set_callback); |
d6b0e80f | 1765 | |
d51926f0 | 1766 | lp = find_lwp_pid (inferior_ptid); |
9f0bdab8 | 1767 | gdb_assert (lp != NULL); |
d6b0e80f | 1768 | |
9f0bdab8 | 1769 | /* Remember if we're stepping. */ |
25289eb2 | 1770 | lp->last_resume_kind = step ? resume_step : resume_continue; |
d6b0e80f | 1771 | |
9f0bdab8 DJ |
1772 | /* If we have a pending wait status for this thread, there is no |
1773 | point in resuming the process. But first make sure that | |
1774 | linux_nat_wait won't preemptively handle the event - we | |
1775 | should never take this short-circuit if we are going to | |
1776 | leave LP running, since we have skipped resuming all the | |
1777 | other threads. This bit of code needs to be synchronized | |
1778 | with linux_nat_wait. */ | |
76f50ad1 | 1779 | |
9f0bdab8 DJ |
1780 | if (lp->status && WIFSTOPPED (lp->status)) |
1781 | { | |
2455069d UW |
1782 | if (!lp->step |
1783 | && WSTOPSIG (lp->status) | |
1784 | && sigismember (&pass_mask, WSTOPSIG (lp->status))) | |
d6b0e80f | 1785 | { |
9327494e SM |
1786 | linux_nat_debug_printf |
1787 | ("Not short circuiting for ignored status 0x%x", lp->status); | |
9f0bdab8 | 1788 | |
d6b0e80f AC |
1789 | /* FIXME: What should we do if we are supposed to continue |
1790 | this thread with a signal? */ | |
a493e3e2 | 1791 | gdb_assert (signo == GDB_SIGNAL_0); |
2ea28649 | 1792 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
9f0bdab8 DJ |
1793 | lp->status = 0; |
1794 | } | |
1795 | } | |
76f50ad1 | 1796 | |
8a99810d | 1797 | if (lwp_status_pending_p (lp)) |
9f0bdab8 DJ |
1798 | { |
1799 | /* FIXME: What should we do if we are supposed to continue | |
1800 | this thread with a signal? */ | |
a493e3e2 | 1801 | gdb_assert (signo == GDB_SIGNAL_0); |
76f50ad1 | 1802 | |
57573e54 PA |
1803 | linux_nat_debug_printf ("Short circuiting for status %s", |
1804 | pending_status_str (lp).c_str ()); | |
d6b0e80f | 1805 | |
7feb7d06 PA |
1806 | if (target_can_async_p ()) |
1807 | { | |
4a570176 | 1808 | target_async (true); |
7feb7d06 PA |
1809 | /* Tell the event loop we have something to process. */ |
1810 | async_file_mark (); | |
1811 | } | |
9f0bdab8 | 1812 | return; |
d6b0e80f AC |
1813 | } |
1814 | ||
d51926f0 PA |
1815 | /* No use iterating unless we're resuming other threads. */ |
1816 | if (scope_ptid != lp->ptid) | |
1817 | iterate_over_lwps (scope_ptid, [=] (struct lwp_info *info) | |
1818 | { | |
1819 | return linux_nat_resume_callback (info, lp); | |
1820 | }); | |
d90e17a7 | 1821 | |
9327494e SM |
1822 | linux_nat_debug_printf ("%s %s, %s (resume event thread)", |
1823 | step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 1824 | lp->ptid.to_string ().c_str (), |
9327494e SM |
1825 | (signo != GDB_SIGNAL_0 |
1826 | ? strsignal (gdb_signal_to_host (signo)) : "0")); | |
b84876c2 | 1827 | |
2bf6fb9d | 1828 | linux_resume_one_lwp (lp, step, signo); |
d6b0e80f AC |
1829 | } |
1830 | ||
c5f62d5f | 1831 | /* Send a signal to an LWP. */ |
d6b0e80f AC |
1832 | |
1833 | static int | |
1834 | kill_lwp (int lwpid, int signo) | |
1835 | { | |
4a6ed09b | 1836 | int ret; |
d6b0e80f | 1837 | |
4a6ed09b PA |
1838 | errno = 0; |
1839 | ret = syscall (__NR_tkill, lwpid, signo); | |
1840 | if (errno == ENOSYS) | |
1841 | { | |
1842 | /* If tkill fails, then we are not using nptl threads, a | |
1843 | configuration we no longer support. */ | |
1844 | perror_with_name (("tkill")); | |
1845 | } | |
1846 | return ret; | |
d6b0e80f AC |
1847 | } |
1848 | ||
ca2163eb PA |
1849 | /* Handle a GNU/Linux syscall trap wait response. If we see a syscall |
1850 | event, check if the core is interested in it: if not, ignore the | |
1851 | event, and keep waiting; otherwise, we need to toggle the LWP's | |
1852 | syscall entry/exit status, since the ptrace event itself doesn't | |
1853 | indicate it, and report the trap to higher layers. */ | |
1854 | ||
1855 | static int | |
1856 | linux_handle_syscall_trap (struct lwp_info *lp, int stopping) | |
1857 | { | |
1858 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
1859 | struct gdbarch *gdbarch = target_thread_architecture (lp->ptid); | |
9213a6d7 | 1860 | thread_info *thread = linux_target->find_thread (lp->ptid); |
00431a78 | 1861 | int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, thread); |
ca2163eb PA |
1862 | |
1863 | if (stopping) | |
1864 | { | |
1865 | /* If we're stopping threads, there's a SIGSTOP pending, which | |
1866 | makes it so that the LWP reports an immediate syscall return, | |
1867 | followed by the SIGSTOP. Skip seeing that "return" using | |
1868 | PTRACE_CONT directly, and let stop_wait_callback collect the | |
1869 | SIGSTOP. Later when the thread is resumed, a new syscall | |
1870 | entry event. If we didn't do this (and returned 0), we'd | |
1871 | leave a syscall entry pending, and our caller, by using | |
1872 | PTRACE_CONT to collect the SIGSTOP, skips the syscall return | |
1873 | itself. Later, when the user re-resumes this LWP, we'd see | |
1874 | another syscall entry event and we'd mistake it for a return. | |
1875 | ||
1876 | If stop_wait_callback didn't force the SIGSTOP out of the LWP | |
1877 | (leaving immediately with LWP->signalled set, without issuing | |
1878 | a PTRACE_CONT), it would still be problematic to leave this | |
1879 | syscall enter pending, as later when the thread is resumed, | |
1880 | it would then see the same syscall exit mentioned above, | |
1881 | followed by the delayed SIGSTOP, while the syscall didn't | |
1882 | actually get to execute. It seems it would be even more | |
1883 | confusing to the user. */ | |
1884 | ||
9327494e SM |
1885 | linux_nat_debug_printf |
1886 | ("ignoring syscall %d for LWP %ld (stopping threads), resuming with " | |
1887 | "PTRACE_CONT for SIGSTOP", syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1888 | |
1889 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
e38504b3 | 1890 | ptrace (PTRACE_CONT, lp->ptid.lwp (), 0, 0); |
8817a6f2 | 1891 | lp->stopped = 0; |
ca2163eb PA |
1892 | return 1; |
1893 | } | |
1894 | ||
bfd09d20 JS |
1895 | /* Always update the entry/return state, even if this particular |
1896 | syscall isn't interesting to the core now. In async mode, | |
1897 | the user could install a new catchpoint for this syscall | |
1898 | between syscall enter/return, and we'll need to know to | |
1899 | report a syscall return if that happens. */ | |
1900 | lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1901 | ? TARGET_WAITKIND_SYSCALL_RETURN | |
1902 | : TARGET_WAITKIND_SYSCALL_ENTRY); | |
1903 | ||
ca2163eb PA |
1904 | if (catch_syscall_enabled ()) |
1905 | { | |
ca2163eb PA |
1906 | if (catching_syscall_number (syscall_number)) |
1907 | { | |
1908 | /* Alright, an event to report. */ | |
183be222 SM |
1909 | if (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY) |
1910 | ourstatus->set_syscall_entry (syscall_number); | |
1911 | else if (lp->syscall_state == TARGET_WAITKIND_SYSCALL_RETURN) | |
1912 | ourstatus->set_syscall_return (syscall_number); | |
1913 | else | |
1914 | gdb_assert_not_reached ("unexpected syscall state"); | |
ca2163eb | 1915 | |
9327494e SM |
1916 | linux_nat_debug_printf |
1917 | ("stopping for %s of syscall %d for LWP %ld", | |
1918 | (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1919 | ? "entry" : "return"), syscall_number, lp->ptid.lwp ()); | |
1920 | ||
ca2163eb PA |
1921 | return 0; |
1922 | } | |
1923 | ||
9327494e SM |
1924 | linux_nat_debug_printf |
1925 | ("ignoring %s of syscall %d for LWP %ld", | |
1926 | (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1927 | ? "entry" : "return"), syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1928 | } |
1929 | else | |
1930 | { | |
1931 | /* If we had been syscall tracing, and hence used PT_SYSCALL | |
1932 | before on this LWP, it could happen that the user removes all | |
1933 | syscall catchpoints before we get to process this event. | |
1934 | There are two noteworthy issues here: | |
1935 | ||
1936 | - When stopped at a syscall entry event, resuming with | |
1937 | PT_STEP still resumes executing the syscall and reports a | |
1938 | syscall return. | |
1939 | ||
1940 | - Only PT_SYSCALL catches syscall enters. If we last | |
1941 | single-stepped this thread, then this event can't be a | |
1942 | syscall enter. If we last single-stepped this thread, this | |
1943 | has to be a syscall exit. | |
1944 | ||
1945 | The points above mean that the next resume, be it PT_STEP or | |
1946 | PT_CONTINUE, can not trigger a syscall trace event. */ | |
9327494e SM |
1947 | linux_nat_debug_printf |
1948 | ("caught syscall event with no syscall catchpoints. %d for LWP %ld, " | |
1949 | "ignoring", syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1950 | lp->syscall_state = TARGET_WAITKIND_IGNORE; |
1951 | } | |
1952 | ||
1953 | /* The core isn't interested in this event. For efficiency, avoid | |
1954 | stopping all threads only to have the core resume them all again. | |
1955 | Since we're not stopping threads, if we're still syscall tracing | |
1956 | and not stepping, we can't use PTRACE_CONT here, as we'd miss any | |
1957 | subsequent syscall. Simply resume using the inf-ptrace layer, | |
1958 | which knows when to use PT_SYSCALL or PT_CONTINUE. */ | |
1959 | ||
8a99810d | 1960 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
ca2163eb PA |
1961 | return 1; |
1962 | } | |
1963 | ||
0d36baa9 PA |
1964 | /* See target.h. */ |
1965 | ||
1966 | void | |
1967 | linux_nat_target::follow_clone (ptid_t child_ptid) | |
1968 | { | |
1969 | lwp_info *new_lp = add_lwp (child_ptid); | |
1970 | new_lp->stopped = 1; | |
1971 | ||
1972 | /* If the thread_db layer is active, let it record the user | |
1973 | level thread id and status, and add the thread to GDB's | |
1974 | list. */ | |
1975 | if (!thread_db_notice_clone (inferior_ptid, new_lp->ptid)) | |
1976 | { | |
1977 | /* The process is not using thread_db. Add the LWP to | |
1978 | GDB's list. */ | |
1979 | add_thread (linux_target, new_lp->ptid); | |
1980 | } | |
1981 | ||
1982 | /* We just created NEW_LP so it cannot yet contain STATUS. */ | |
1983 | gdb_assert (new_lp->status == 0); | |
1984 | ||
1985 | if (!pull_pid_from_list (&stopped_pids, child_ptid.lwp (), &new_lp->status)) | |
1986 | internal_error (_("no saved status for clone lwp")); | |
1987 | ||
1988 | if (WSTOPSIG (new_lp->status) != SIGSTOP) | |
1989 | { | |
1990 | /* This can happen if someone starts sending signals to | |
1991 | the new thread before it gets a chance to run, which | |
1992 | have a lower number than SIGSTOP (e.g. SIGUSR1). | |
1993 | This is an unlikely case, and harder to handle for | |
1994 | fork / vfork than for clone, so we do not try - but | |
1995 | we handle it for clone events here. */ | |
1996 | ||
1997 | new_lp->signalled = 1; | |
1998 | ||
1999 | /* Save the wait status to report later. */ | |
2000 | linux_nat_debug_printf | |
2001 | ("waitpid of new LWP %ld, saving status %s", | |
2002 | (long) new_lp->ptid.lwp (), status_to_str (new_lp->status).c_str ()); | |
2003 | } | |
2004 | else | |
2005 | { | |
2006 | new_lp->status = 0; | |
2007 | ||
2008 | if (report_thread_events) | |
2009 | new_lp->waitstatus.set_thread_created (); | |
2010 | } | |
2011 | } | |
2012 | ||
3d799a95 DJ |
2013 | /* Handle a GNU/Linux extended wait response. If we see a clone |
2014 | event, we need to add the new LWP to our list (and not report the | |
2015 | trap to higher layers). This function returns non-zero if the | |
2016 | event should be ignored and we should wait again. If STOPPING is | |
2017 | true, the new LWP remains stopped, otherwise it is continued. */ | |
d6b0e80f AC |
2018 | |
2019 | static int | |
4dd63d48 | 2020 | linux_handle_extended_wait (struct lwp_info *lp, int status) |
d6b0e80f | 2021 | { |
e38504b3 | 2022 | int pid = lp->ptid.lwp (); |
3d799a95 | 2023 | struct target_waitstatus *ourstatus = &lp->waitstatus; |
89a5711c | 2024 | int event = linux_ptrace_get_extended_event (status); |
d6b0e80f | 2025 | |
bfd09d20 JS |
2026 | /* All extended events we currently use are mid-syscall. Only |
2027 | PTRACE_EVENT_STOP is delivered more like a signal-stop, but | |
2028 | you have to be using PTRACE_SEIZE to get that. */ | |
2029 | lp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY; | |
2030 | ||
3d799a95 DJ |
2031 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
2032 | || event == PTRACE_EVENT_CLONE) | |
d6b0e80f | 2033 | { |
3d799a95 DJ |
2034 | unsigned long new_pid; |
2035 | int ret; | |
2036 | ||
2037 | ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); | |
6fc19103 | 2038 | |
3d799a95 DJ |
2039 | /* If we haven't already seen the new PID stop, wait for it now. */ |
2040 | if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
2041 | { | |
2042 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
2043 | hits the SIGSTOP, but we're already attached. */ | |
4a6ed09b | 2044 | ret = my_waitpid (new_pid, &status, __WALL); |
3d799a95 DJ |
2045 | if (ret == -1) |
2046 | perror_with_name (_("waiting for new child")); | |
2047 | else if (ret != new_pid) | |
f34652de | 2048 | internal_error (_("wait returned unexpected PID %d"), ret); |
3d799a95 | 2049 | else if (!WIFSTOPPED (status)) |
f34652de | 2050 | internal_error (_("wait returned unexpected status 0x%x"), status); |
3d799a95 DJ |
2051 | } |
2052 | ||
26cb8b7c PA |
2053 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) |
2054 | { | |
0d36baa9 | 2055 | open_proc_mem_file (ptid_t (new_pid, new_pid)); |
8a89ddbd | 2056 | |
26cb8b7c PA |
2057 | /* The arch-specific native code may need to know about new |
2058 | forks even if those end up never mapped to an | |
2059 | inferior. */ | |
135340af | 2060 | linux_target->low_new_fork (lp, new_pid); |
26cb8b7c | 2061 | } |
1310c1b0 PFC |
2062 | else if (event == PTRACE_EVENT_CLONE) |
2063 | { | |
2064 | linux_target->low_new_clone (lp, new_pid); | |
2065 | } | |
26cb8b7c | 2066 | |
2277426b | 2067 | if (event == PTRACE_EVENT_FORK |
e99b03dc | 2068 | && linux_fork_checkpointing_p (lp->ptid.pid ())) |
2277426b | 2069 | { |
2277426b PA |
2070 | /* Handle checkpointing by linux-fork.c here as a special |
2071 | case. We don't want the follow-fork-mode or 'catch fork' | |
2072 | to interfere with this. */ | |
2073 | ||
2074 | /* This won't actually modify the breakpoint list, but will | |
2075 | physically remove the breakpoints from the child. */ | |
184ea2f7 | 2076 | detach_breakpoints (ptid_t (new_pid, new_pid)); |
2277426b PA |
2077 | |
2078 | /* Retain child fork in ptrace (stopped) state. */ | |
14571dad MS |
2079 | if (!find_fork_pid (new_pid)) |
2080 | add_fork (new_pid); | |
2277426b PA |
2081 | |
2082 | /* Report as spurious, so that infrun doesn't want to follow | |
2083 | this fork. We're actually doing an infcall in | |
2084 | linux-fork.c. */ | |
183be222 | 2085 | ourstatus->set_spurious (); |
2277426b PA |
2086 | |
2087 | /* Report the stop to the core. */ | |
2088 | return 0; | |
2089 | } | |
2090 | ||
3d799a95 | 2091 | if (event == PTRACE_EVENT_FORK) |
0d36baa9 | 2092 | ourstatus->set_forked (ptid_t (new_pid, new_pid)); |
3d799a95 | 2093 | else if (event == PTRACE_EVENT_VFORK) |
0d36baa9 | 2094 | ourstatus->set_vforked (ptid_t (new_pid, new_pid)); |
4dd63d48 | 2095 | else if (event == PTRACE_EVENT_CLONE) |
3d799a95 | 2096 | { |
9327494e SM |
2097 | linux_nat_debug_printf |
2098 | ("Got clone event from LWP %d, new child is LWP %ld", pid, new_pid); | |
3c4d7e12 | 2099 | |
0d36baa9 PA |
2100 | /* Save the status again, we'll use it in follow_clone. */ |
2101 | add_to_pid_list (&stopped_pids, new_pid, status); | |
4dd63d48 | 2102 | |
0d36baa9 | 2103 | ourstatus->set_thread_cloned (ptid_t (lp->ptid.pid (), new_pid)); |
3d799a95 DJ |
2104 | } |
2105 | ||
2106 | return 0; | |
d6b0e80f AC |
2107 | } |
2108 | ||
3d799a95 DJ |
2109 | if (event == PTRACE_EVENT_EXEC) |
2110 | { | |
9327494e | 2111 | linux_nat_debug_printf ("Got exec event from LWP %ld", lp->ptid.lwp ()); |
a75724bc | 2112 | |
8a89ddbd PA |
2113 | /* Close the previous /proc/PID/mem file for this inferior, |
2114 | which was using the address space which is now gone. | |
2115 | Reading/writing from this file would return 0/EOF. */ | |
2116 | close_proc_mem_file (lp->ptid.pid ()); | |
2117 | ||
2118 | /* Open a new file for the new address space. */ | |
2119 | open_proc_mem_file (lp->ptid); | |
05c06f31 | 2120 | |
183be222 SM |
2121 | ourstatus->set_execd |
2122 | (make_unique_xstrdup (linux_proc_pid_to_exec_file (pid))); | |
3d799a95 | 2123 | |
8af756ef PA |
2124 | /* The thread that execed must have been resumed, but, when a |
2125 | thread execs, it changes its tid to the tgid, and the old | |
2126 | tgid thread might have not been resumed. */ | |
2127 | lp->resumed = 1; | |
6a534f85 PA |
2128 | |
2129 | /* All other LWPs are gone now. We'll have received a thread | |
2130 | exit notification for all threads other the execing one. | |
2131 | That one, if it wasn't the leader, just silently changes its | |
2132 | tid to the tgid, and the previous leader vanishes. Since | |
2133 | Linux 3.0, the former thread ID can be retrieved with | |
2134 | PTRACE_GETEVENTMSG, but since we support older kernels, don't | |
2135 | bother with it, and just walk the LWP list. Even with | |
2136 | PTRACE_GETEVENTMSG, we'd still need to lookup the | |
2137 | corresponding LWP object, and it would be an extra ptrace | |
2138 | syscall, so this way may even be more efficient. */ | |
2139 | for (lwp_info *other_lp : all_lwps_safe ()) | |
2140 | if (other_lp != lp && other_lp->ptid.pid () == lp->ptid.pid ()) | |
2141 | exit_lwp (other_lp); | |
2142 | ||
6c95b8df PA |
2143 | return 0; |
2144 | } | |
2145 | ||
2146 | if (event == PTRACE_EVENT_VFORK_DONE) | |
2147 | { | |
9327494e | 2148 | linux_nat_debug_printf |
5a0c4a06 SM |
2149 | ("Got PTRACE_EVENT_VFORK_DONE from LWP %ld", |
2150 | lp->ptid.lwp ()); | |
2151 | ourstatus->set_vfork_done (); | |
2152 | return 0; | |
3d799a95 DJ |
2153 | } |
2154 | ||
f34652de | 2155 | internal_error (_("unknown ptrace event %d"), event); |
d6b0e80f AC |
2156 | } |
2157 | ||
9c3a5d93 PA |
2158 | /* Suspend waiting for a signal. We're mostly interested in |
2159 | SIGCHLD/SIGINT. */ | |
2160 | ||
2161 | static void | |
2162 | wait_for_signal () | |
2163 | { | |
9327494e | 2164 | linux_nat_debug_printf ("about to sigsuspend"); |
9c3a5d93 PA |
2165 | sigsuspend (&suspend_mask); |
2166 | ||
2167 | /* If the quit flag is set, it means that the user pressed Ctrl-C | |
2168 | and we're debugging a process that is running on a separate | |
2169 | terminal, so we must forward the Ctrl-C to the inferior. (If the | |
2170 | inferior is sharing GDB's terminal, then the Ctrl-C reaches the | |
2171 | inferior directly.) We must do this here because functions that | |
2172 | need to block waiting for a signal loop forever until there's an | |
2173 | event to report before returning back to the event loop. */ | |
2174 | if (!target_terminal::is_ours ()) | |
2175 | { | |
2176 | if (check_quit_flag ()) | |
2177 | target_pass_ctrlc (); | |
2178 | } | |
2179 | } | |
2180 | ||
3d2d2172 PA |
2181 | /* Mark LWP dead, with STATUS as exit status pending to report |
2182 | later. */ | |
2183 | ||
2184 | static void | |
2185 | mark_lwp_dead (lwp_info *lp, int status) | |
2186 | { | |
2187 | /* Store the exit status lp->waitstatus, because lp->status would be | |
2188 | ambiguous (W_EXITCODE(0,0) == 0). */ | |
2189 | lp->waitstatus = host_status_to_waitstatus (status); | |
2190 | ||
2191 | /* If we're processing LP's status, there should be no other event | |
2192 | already recorded as pending. */ | |
2193 | gdb_assert (lp->status == 0); | |
2194 | ||
2195 | /* Dead LWPs aren't expected to report a pending sigstop. */ | |
2196 | lp->signalled = 0; | |
2197 | ||
2198 | /* Prevent trying to stop it. */ | |
2199 | lp->stopped = 1; | |
2200 | } | |
2201 | ||
5e86aab8 PA |
2202 | /* Return true if LP is dead, with a pending exit/signalled event. */ |
2203 | ||
2204 | static bool | |
2205 | is_lwp_marked_dead (lwp_info *lp) | |
2206 | { | |
2207 | switch (lp->waitstatus.kind ()) | |
2208 | { | |
2209 | case TARGET_WAITKIND_EXITED: | |
2210 | case TARGET_WAITKIND_THREAD_EXITED: | |
2211 | case TARGET_WAITKIND_SIGNALLED: | |
2212 | return true; | |
2213 | } | |
2214 | return false; | |
2215 | } | |
2216 | ||
d6b0e80f AC |
2217 | /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has |
2218 | exited. */ | |
2219 | ||
2220 | static int | |
2221 | wait_lwp (struct lwp_info *lp) | |
2222 | { | |
2223 | pid_t pid; | |
432b4d03 | 2224 | int status = 0; |
d6b0e80f | 2225 | int thread_dead = 0; |
432b4d03 | 2226 | sigset_t prev_mask; |
d6b0e80f AC |
2227 | |
2228 | gdb_assert (!lp->stopped); | |
2229 | gdb_assert (lp->status == 0); | |
2230 | ||
432b4d03 JK |
2231 | /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
2232 | block_child_signals (&prev_mask); | |
2233 | ||
2234 | for (;;) | |
d6b0e80f | 2235 | { |
e38504b3 | 2236 | pid = my_waitpid (lp->ptid.lwp (), &status, __WALL | WNOHANG); |
a9f4bb21 PA |
2237 | if (pid == -1 && errno == ECHILD) |
2238 | { | |
2239 | /* The thread has previously exited. We need to delete it | |
4a6ed09b PA |
2240 | now because if this was a non-leader thread execing, we |
2241 | won't get an exit event. See comments on exec events at | |
2242 | the top of the file. */ | |
a9f4bb21 | 2243 | thread_dead = 1; |
9327494e | 2244 | linux_nat_debug_printf ("%s vanished.", |
e53c95d4 | 2245 | lp->ptid.to_string ().c_str ()); |
a9f4bb21 | 2246 | } |
432b4d03 JK |
2247 | if (pid != 0) |
2248 | break; | |
2249 | ||
2250 | /* Bugs 10970, 12702. | |
2251 | Thread group leader may have exited in which case we'll lock up in | |
2252 | waitpid if there are other threads, even if they are all zombies too. | |
2253 | Basically, we're not supposed to use waitpid this way. | |
4a6ed09b PA |
2254 | tkill(pid,0) cannot be used here as it gets ESRCH for both |
2255 | for zombie and running processes. | |
432b4d03 JK |
2256 | |
2257 | As a workaround, check if we're waiting for the thread group leader and | |
2258 | if it's a zombie, and avoid calling waitpid if it is. | |
2259 | ||
2260 | This is racy, what if the tgl becomes a zombie right after we check? | |
2261 | Therefore always use WNOHANG with sigsuspend - it is equivalent to | |
5f572dec | 2262 | waiting waitpid but linux_proc_pid_is_zombie is safe this way. */ |
432b4d03 | 2263 | |
e38504b3 TT |
2264 | if (lp->ptid.pid () == lp->ptid.lwp () |
2265 | && linux_proc_pid_is_zombie (lp->ptid.lwp ())) | |
d6b0e80f | 2266 | { |
d6b0e80f | 2267 | thread_dead = 1; |
9327494e | 2268 | linux_nat_debug_printf ("Thread group leader %s vanished.", |
e53c95d4 | 2269 | lp->ptid.to_string ().c_str ()); |
432b4d03 | 2270 | break; |
d6b0e80f | 2271 | } |
432b4d03 JK |
2272 | |
2273 | /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers | |
2274 | get invoked despite our caller had them intentionally blocked by | |
2275 | block_child_signals. This is sensitive only to the loop of | |
2276 | linux_nat_wait_1 and there if we get called my_waitpid gets called | |
2277 | again before it gets to sigsuspend so we can safely let the handlers | |
2278 | get executed here. */ | |
9c3a5d93 | 2279 | wait_for_signal (); |
432b4d03 JK |
2280 | } |
2281 | ||
2282 | restore_child_signals_mask (&prev_mask); | |
2283 | ||
d6b0e80f AC |
2284 | if (!thread_dead) |
2285 | { | |
e38504b3 | 2286 | gdb_assert (pid == lp->ptid.lwp ()); |
d6b0e80f | 2287 | |
9327494e | 2288 | linux_nat_debug_printf ("waitpid %s received %s", |
e53c95d4 | 2289 | lp->ptid.to_string ().c_str (), |
8d06918f | 2290 | status_to_str (status).c_str ()); |
d6b0e80f | 2291 | |
a9f4bb21 PA |
2292 | /* Check if the thread has exited. */ |
2293 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
2294 | { | |
a51e14ef | 2295 | if (report_exit_events_for (lp) || is_leader (lp)) |
69dde7dc | 2296 | { |
9327494e | 2297 | linux_nat_debug_printf ("LWP %d exited.", lp->ptid.pid ()); |
69dde7dc | 2298 | |
aa01bd36 | 2299 | /* If this is the leader exiting, it means the whole |
69dde7dc | 2300 | process is gone. Store the status to report to the |
3d2d2172 PA |
2301 | core. */ |
2302 | mark_lwp_dead (lp, status); | |
69dde7dc PA |
2303 | return 0; |
2304 | } | |
2305 | ||
a9f4bb21 | 2306 | thread_dead = 1; |
9327494e | 2307 | linux_nat_debug_printf ("%s exited.", |
e53c95d4 | 2308 | lp->ptid.to_string ().c_str ()); |
a9f4bb21 | 2309 | } |
d6b0e80f AC |
2310 | } |
2311 | ||
2312 | if (thread_dead) | |
2313 | { | |
e26af52f | 2314 | exit_lwp (lp); |
d6b0e80f AC |
2315 | return 0; |
2316 | } | |
2317 | ||
2318 | gdb_assert (WIFSTOPPED (status)); | |
8817a6f2 | 2319 | lp->stopped = 1; |
d6b0e80f | 2320 | |
8784d563 PA |
2321 | if (lp->must_set_ptrace_flags) |
2322 | { | |
5b6d1e4f | 2323 | inferior *inf = find_inferior_pid (linux_target, lp->ptid.pid ()); |
de0d863e | 2324 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 2325 | |
e38504b3 | 2326 | linux_enable_event_reporting (lp->ptid.lwp (), options); |
8784d563 PA |
2327 | lp->must_set_ptrace_flags = 0; |
2328 | } | |
2329 | ||
ca2163eb PA |
2330 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2331 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2332 | { | |
2333 | /* No longer need the sysgood bit. The ptrace event ends up | |
2334 | recorded in lp->waitstatus if we care for it. We can carry | |
2335 | on handling the event like a regular SIGTRAP from here | |
2336 | on. */ | |
2337 | status = W_STOPCODE (SIGTRAP); | |
2338 | if (linux_handle_syscall_trap (lp, 1)) | |
2339 | return wait_lwp (lp); | |
2340 | } | |
bfd09d20 JS |
2341 | else |
2342 | { | |
2343 | /* Almost all other ptrace-stops are known to be outside of system | |
2344 | calls, with further exceptions in linux_handle_extended_wait. */ | |
2345 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2346 | } | |
ca2163eb | 2347 | |
d6b0e80f | 2348 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2349 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2350 | && linux_is_extended_waitstatus (status)) | |
d6b0e80f | 2351 | { |
9327494e | 2352 | linux_nat_debug_printf ("Handling extended status 0x%06x", status); |
4dd63d48 | 2353 | linux_handle_extended_wait (lp, status); |
20ba1ce6 | 2354 | return 0; |
d6b0e80f AC |
2355 | } |
2356 | ||
2357 | return status; | |
2358 | } | |
2359 | ||
2360 | /* Send a SIGSTOP to LP. */ | |
2361 | ||
2362 | static int | |
d3a70e03 | 2363 | stop_callback (struct lwp_info *lp) |
d6b0e80f AC |
2364 | { |
2365 | if (!lp->stopped && !lp->signalled) | |
2366 | { | |
2367 | int ret; | |
2368 | ||
9327494e | 2369 | linux_nat_debug_printf ("kill %s **<SIGSTOP>**", |
e53c95d4 | 2370 | lp->ptid.to_string ().c_str ()); |
9327494e | 2371 | |
d6b0e80f | 2372 | errno = 0; |
e38504b3 | 2373 | ret = kill_lwp (lp->ptid.lwp (), SIGSTOP); |
9327494e | 2374 | linux_nat_debug_printf ("lwp kill %d %s", ret, |
d6b0e80f | 2375 | errno ? safe_strerror (errno) : "ERRNO-OK"); |
d6b0e80f AC |
2376 | |
2377 | lp->signalled = 1; | |
2378 | gdb_assert (lp->status == 0); | |
2379 | } | |
2380 | ||
2381 | return 0; | |
2382 | } | |
2383 | ||
7b50312a PA |
2384 | /* Request a stop on LWP. */ |
2385 | ||
2386 | void | |
2387 | linux_stop_lwp (struct lwp_info *lwp) | |
2388 | { | |
d3a70e03 | 2389 | stop_callback (lwp); |
7b50312a PA |
2390 | } |
2391 | ||
2db9a427 PA |
2392 | /* See linux-nat.h */ |
2393 | ||
2394 | void | |
2395 | linux_stop_and_wait_all_lwps (void) | |
2396 | { | |
2397 | /* Stop all LWP's ... */ | |
d3a70e03 | 2398 | iterate_over_lwps (minus_one_ptid, stop_callback); |
2db9a427 PA |
2399 | |
2400 | /* ... and wait until all of them have reported back that | |
2401 | they're no longer running. */ | |
d3a70e03 | 2402 | iterate_over_lwps (minus_one_ptid, stop_wait_callback); |
2db9a427 PA |
2403 | } |
2404 | ||
2405 | /* See linux-nat.h */ | |
2406 | ||
2407 | void | |
2408 | linux_unstop_all_lwps (void) | |
2409 | { | |
2410 | iterate_over_lwps (minus_one_ptid, | |
d3a70e03 TT |
2411 | [] (struct lwp_info *info) |
2412 | { | |
2413 | return resume_stopped_resumed_lwps (info, minus_one_ptid); | |
2414 | }); | |
2db9a427 PA |
2415 | } |
2416 | ||
57380f4e | 2417 | /* Return non-zero if LWP PID has a pending SIGINT. */ |
d6b0e80f AC |
2418 | |
2419 | static int | |
57380f4e DJ |
2420 | linux_nat_has_pending_sigint (int pid) |
2421 | { | |
2422 | sigset_t pending, blocked, ignored; | |
57380f4e DJ |
2423 | |
2424 | linux_proc_pending_signals (pid, &pending, &blocked, &ignored); | |
2425 | ||
2426 | if (sigismember (&pending, SIGINT) | |
2427 | && !sigismember (&ignored, SIGINT)) | |
2428 | return 1; | |
2429 | ||
2430 | return 0; | |
2431 | } | |
2432 | ||
2433 | /* Set a flag in LP indicating that we should ignore its next SIGINT. */ | |
2434 | ||
2435 | static int | |
d3a70e03 | 2436 | set_ignore_sigint (struct lwp_info *lp) |
d6b0e80f | 2437 | { |
57380f4e DJ |
2438 | /* If a thread has a pending SIGINT, consume it; otherwise, set a |
2439 | flag to consume the next one. */ | |
2440 | if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) | |
2441 | && WSTOPSIG (lp->status) == SIGINT) | |
2442 | lp->status = 0; | |
2443 | else | |
2444 | lp->ignore_sigint = 1; | |
2445 | ||
2446 | return 0; | |
2447 | } | |
2448 | ||
2449 | /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. | |
2450 | This function is called after we know the LWP has stopped; if the LWP | |
2451 | stopped before the expected SIGINT was delivered, then it will never have | |
2452 | arrived. Also, if the signal was delivered to a shared queue and consumed | |
2453 | by a different thread, it will never be delivered to this LWP. */ | |
d6b0e80f | 2454 | |
57380f4e DJ |
2455 | static void |
2456 | maybe_clear_ignore_sigint (struct lwp_info *lp) | |
2457 | { | |
2458 | if (!lp->ignore_sigint) | |
2459 | return; | |
2460 | ||
e38504b3 | 2461 | if (!linux_nat_has_pending_sigint (lp->ptid.lwp ())) |
57380f4e | 2462 | { |
9327494e | 2463 | linux_nat_debug_printf ("Clearing bogus flag for %s", |
e53c95d4 | 2464 | lp->ptid.to_string ().c_str ()); |
57380f4e DJ |
2465 | lp->ignore_sigint = 0; |
2466 | } | |
2467 | } | |
2468 | ||
ebec9a0f PA |
2469 | /* Fetch the possible triggered data watchpoint info and store it in |
2470 | LP. | |
2471 | ||
2472 | On some archs, like x86, that use debug registers to set | |
2473 | watchpoints, it's possible that the way to know which watched | |
2474 | address trapped, is to check the register that is used to select | |
2475 | which address to watch. Problem is, between setting the watchpoint | |
2476 | and reading back which data address trapped, the user may change | |
2477 | the set of watchpoints, and, as a consequence, GDB changes the | |
2478 | debug registers in the inferior. To avoid reading back a stale | |
2479 | stopped-data-address when that happens, we cache in LP the fact | |
2480 | that a watchpoint trapped, and the corresponding data address, as | |
2481 | soon as we see LP stop with a SIGTRAP. If GDB changes the debug | |
2482 | registers meanwhile, we have the cached data we can rely on. */ | |
2483 | ||
9c02b525 PA |
2484 | static int |
2485 | check_stopped_by_watchpoint (struct lwp_info *lp) | |
ebec9a0f | 2486 | { |
2989a365 | 2487 | scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); |
ebec9a0f PA |
2488 | inferior_ptid = lp->ptid; |
2489 | ||
f6ac5f3d | 2490 | if (linux_target->low_stopped_by_watchpoint ()) |
ebec9a0f | 2491 | { |
15c66dd6 | 2492 | lp->stop_reason = TARGET_STOPPED_BY_WATCHPOINT; |
f6ac5f3d PA |
2493 | lp->stopped_data_address_p |
2494 | = linux_target->low_stopped_data_address (&lp->stopped_data_address); | |
ebec9a0f PA |
2495 | } |
2496 | ||
15c66dd6 | 2497 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
9c02b525 PA |
2498 | } |
2499 | ||
9c02b525 | 2500 | /* Returns true if the LWP had stopped for a watchpoint. */ |
ebec9a0f | 2501 | |
57810aa7 | 2502 | bool |
f6ac5f3d | 2503 | linux_nat_target::stopped_by_watchpoint () |
ebec9a0f PA |
2504 | { |
2505 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2506 | ||
2507 | gdb_assert (lp != NULL); | |
2508 | ||
15c66dd6 | 2509 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
ebec9a0f PA |
2510 | } |
2511 | ||
57810aa7 | 2512 | bool |
f6ac5f3d | 2513 | linux_nat_target::stopped_data_address (CORE_ADDR *addr_p) |
ebec9a0f PA |
2514 | { |
2515 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2516 | ||
2517 | gdb_assert (lp != NULL); | |
2518 | ||
2519 | *addr_p = lp->stopped_data_address; | |
2520 | ||
2521 | return lp->stopped_data_address_p; | |
2522 | } | |
2523 | ||
26ab7092 JK |
2524 | /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
2525 | ||
135340af PA |
2526 | bool |
2527 | linux_nat_target::low_status_is_event (int status) | |
26ab7092 JK |
2528 | { |
2529 | return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; | |
2530 | } | |
2531 | ||
57380f4e DJ |
2532 | /* Wait until LP is stopped. */ |
2533 | ||
2534 | static int | |
d3a70e03 | 2535 | stop_wait_callback (struct lwp_info *lp) |
57380f4e | 2536 | { |
5b6d1e4f | 2537 | inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
6c95b8df PA |
2538 | |
2539 | /* If this is a vfork parent, bail out, it is not going to report | |
2540 | any SIGSTOP until the vfork is done with. */ | |
2541 | if (inf->vfork_child != NULL) | |
2542 | return 0; | |
2543 | ||
d6b0e80f AC |
2544 | if (!lp->stopped) |
2545 | { | |
2546 | int status; | |
2547 | ||
2548 | status = wait_lwp (lp); | |
2549 | if (status == 0) | |
2550 | return 0; | |
2551 | ||
57380f4e DJ |
2552 | if (lp->ignore_sigint && WIFSTOPPED (status) |
2553 | && WSTOPSIG (status) == SIGINT) | |
d6b0e80f | 2554 | { |
57380f4e | 2555 | lp->ignore_sigint = 0; |
d6b0e80f AC |
2556 | |
2557 | errno = 0; | |
e38504b3 | 2558 | ptrace (PTRACE_CONT, lp->ptid.lwp (), 0, 0); |
8817a6f2 | 2559 | lp->stopped = 0; |
9327494e SM |
2560 | linux_nat_debug_printf |
2561 | ("PTRACE_CONT %s, 0, 0 (%s) (discarding SIGINT)", | |
e53c95d4 | 2562 | lp->ptid.to_string ().c_str (), |
9327494e | 2563 | errno ? safe_strerror (errno) : "OK"); |
d6b0e80f | 2564 | |
d3a70e03 | 2565 | return stop_wait_callback (lp); |
d6b0e80f AC |
2566 | } |
2567 | ||
57380f4e DJ |
2568 | maybe_clear_ignore_sigint (lp); |
2569 | ||
d6b0e80f AC |
2570 | if (WSTOPSIG (status) != SIGSTOP) |
2571 | { | |
e5ef252a | 2572 | /* The thread was stopped with a signal other than SIGSTOP. */ |
7feb7d06 | 2573 | |
9327494e | 2574 | linux_nat_debug_printf ("Pending event %s in %s", |
8d06918f | 2575 | status_to_str ((int) status).c_str (), |
e53c95d4 | 2576 | lp->ptid.to_string ().c_str ()); |
e5ef252a PA |
2577 | |
2578 | /* Save the sigtrap event. */ | |
2579 | lp->status = status; | |
e5ef252a | 2580 | gdb_assert (lp->signalled); |
e7ad2f14 | 2581 | save_stop_reason (lp); |
d6b0e80f AC |
2582 | } |
2583 | else | |
2584 | { | |
7010835a | 2585 | /* We caught the SIGSTOP that we intended to catch. */ |
e5ef252a | 2586 | |
9327494e | 2587 | linux_nat_debug_printf ("Expected SIGSTOP caught for %s.", |
e53c95d4 | 2588 | lp->ptid.to_string ().c_str ()); |
e5ef252a | 2589 | |
d6b0e80f | 2590 | lp->signalled = 0; |
7010835a AB |
2591 | |
2592 | /* If we are waiting for this stop so we can report the thread | |
2593 | stopped then we need to record this status. Otherwise, we can | |
2594 | now discard this stop event. */ | |
2595 | if (lp->last_resume_kind == resume_stop) | |
2596 | { | |
2597 | lp->status = status; | |
2598 | save_stop_reason (lp); | |
2599 | } | |
d6b0e80f AC |
2600 | } |
2601 | } | |
2602 | ||
2603 | return 0; | |
2604 | } | |
2605 | ||
74387712 SM |
2606 | /* Get the inferior associated to LWP. Must be called with an LWP that has |
2607 | an associated inferior. Always return non-nullptr. */ | |
2608 | ||
2609 | static inferior * | |
2610 | lwp_inferior (const lwp_info *lwp) | |
2611 | { | |
2612 | inferior *inf = find_inferior_ptid (linux_target, lwp->ptid); | |
2613 | gdb_assert (inf != nullptr); | |
2614 | return inf; | |
2615 | } | |
2616 | ||
9c02b525 PA |
2617 | /* Return non-zero if LP has a wait status pending. Discard the |
2618 | pending event and resume the LWP if the event that originally | |
2619 | caused the stop became uninteresting. */ | |
d6b0e80f AC |
2620 | |
2621 | static int | |
d3a70e03 | 2622 | status_callback (struct lwp_info *lp) |
d6b0e80f AC |
2623 | { |
2624 | /* Only report a pending wait status if we pretend that this has | |
2625 | indeed been resumed. */ | |
ca2163eb PA |
2626 | if (!lp->resumed) |
2627 | return 0; | |
2628 | ||
eb54c8bf PA |
2629 | if (!lwp_status_pending_p (lp)) |
2630 | return 0; | |
2631 | ||
15c66dd6 PA |
2632 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
2633 | || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) | |
9c02b525 | 2634 | { |
5b6d1e4f | 2635 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
9c02b525 PA |
2636 | CORE_ADDR pc; |
2637 | int discard = 0; | |
2638 | ||
9c02b525 PA |
2639 | pc = regcache_read_pc (regcache); |
2640 | ||
2641 | if (pc != lp->stop_pc) | |
2642 | { | |
9327494e | 2643 | linux_nat_debug_printf ("PC of %s changed. was=%s, now=%s", |
e53c95d4 | 2644 | lp->ptid.to_string ().c_str (), |
99d9c3b9 SM |
2645 | paddress (current_inferior ()->arch (), |
2646 | lp->stop_pc), | |
2647 | paddress (current_inferior ()->arch (), pc)); | |
9c02b525 PA |
2648 | discard = 1; |
2649 | } | |
faf09f01 | 2650 | |
9c02b525 PA |
2651 | if (discard) |
2652 | { | |
9327494e | 2653 | linux_nat_debug_printf ("pending event of %s cancelled.", |
e53c95d4 | 2654 | lp->ptid.to_string ().c_str ()); |
9c02b525 PA |
2655 | |
2656 | lp->status = 0; | |
2657 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); | |
2658 | return 0; | |
2659 | } | |
9c02b525 PA |
2660 | } |
2661 | ||
eb54c8bf | 2662 | return 1; |
d6b0e80f AC |
2663 | } |
2664 | ||
d6b0e80f AC |
2665 | /* Count the LWP's that have had events. */ |
2666 | ||
2667 | static int | |
d3a70e03 | 2668 | count_events_callback (struct lwp_info *lp, int *count) |
d6b0e80f | 2669 | { |
d6b0e80f AC |
2670 | gdb_assert (count != NULL); |
2671 | ||
9c02b525 PA |
2672 | /* Select only resumed LWPs that have an event pending. */ |
2673 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2674 | (*count)++; |
2675 | ||
2676 | return 0; | |
2677 | } | |
2678 | ||
2679 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
2680 | ||
2681 | static int | |
d3a70e03 | 2682 | select_singlestep_lwp_callback (struct lwp_info *lp) |
d6b0e80f | 2683 | { |
25289eb2 PA |
2684 | if (lp->last_resume_kind == resume_step |
2685 | && lp->status != 0) | |
d6b0e80f AC |
2686 | return 1; |
2687 | else | |
2688 | return 0; | |
2689 | } | |
2690 | ||
8a99810d PA |
2691 | /* Returns true if LP has a status pending. */ |
2692 | ||
2693 | static int | |
2694 | lwp_status_pending_p (struct lwp_info *lp) | |
2695 | { | |
2696 | /* We check for lp->waitstatus in addition to lp->status, because we | |
2697 | can have pending process exits recorded in lp->status and | |
2698 | W_EXITCODE(0,0) happens to be 0. */ | |
183be222 | 2699 | return lp->status != 0 || lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE; |
8a99810d PA |
2700 | } |
2701 | ||
b90fc188 | 2702 | /* Select the Nth LWP that has had an event. */ |
d6b0e80f AC |
2703 | |
2704 | static int | |
d3a70e03 | 2705 | select_event_lwp_callback (struct lwp_info *lp, int *selector) |
d6b0e80f | 2706 | { |
d6b0e80f AC |
2707 | gdb_assert (selector != NULL); |
2708 | ||
9c02b525 PA |
2709 | /* Select only resumed LWPs that have an event pending. */ |
2710 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2711 | if ((*selector)-- == 0) |
2712 | return 1; | |
2713 | ||
2714 | return 0; | |
2715 | } | |
2716 | ||
e7ad2f14 PA |
2717 | /* Called when the LWP stopped for a signal/trap. If it stopped for a |
2718 | trap check what caused it (breakpoint, watchpoint, trace, etc.), | |
2719 | and save the result in the LWP's stop_reason field. If it stopped | |
2720 | for a breakpoint, decrement the PC if necessary on the lwp's | |
2721 | architecture. */ | |
9c02b525 | 2722 | |
e7ad2f14 PA |
2723 | static void |
2724 | save_stop_reason (struct lwp_info *lp) | |
710151dd | 2725 | { |
e7ad2f14 PA |
2726 | struct regcache *regcache; |
2727 | struct gdbarch *gdbarch; | |
515630c5 | 2728 | CORE_ADDR pc; |
9c02b525 | 2729 | CORE_ADDR sw_bp_pc; |
faf09f01 | 2730 | siginfo_t siginfo; |
9c02b525 | 2731 | |
e7ad2f14 PA |
2732 | gdb_assert (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON); |
2733 | gdb_assert (lp->status != 0); | |
2734 | ||
135340af | 2735 | if (!linux_target->low_status_is_event (lp->status)) |
e7ad2f14 PA |
2736 | return; |
2737 | ||
74387712 | 2738 | inferior *inf = lwp_inferior (lp); |
a9deee17 PA |
2739 | if (inf->starting_up) |
2740 | return; | |
2741 | ||
5b6d1e4f | 2742 | regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 2743 | gdbarch = regcache->arch (); |
e7ad2f14 | 2744 | |
9c02b525 | 2745 | pc = regcache_read_pc (regcache); |
527a273a | 2746 | sw_bp_pc = pc - gdbarch_decr_pc_after_break (gdbarch); |
515630c5 | 2747 | |
faf09f01 PA |
2748 | if (linux_nat_get_siginfo (lp->ptid, &siginfo)) |
2749 | { | |
2750 | if (siginfo.si_signo == SIGTRAP) | |
2751 | { | |
e7ad2f14 PA |
2752 | if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code) |
2753 | && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) | |
faf09f01 | 2754 | { |
e7ad2f14 PA |
2755 | /* The si_code is ambiguous on this arch -- check debug |
2756 | registers. */ | |
2757 | if (!check_stopped_by_watchpoint (lp)) | |
2758 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2759 | } | |
2760 | else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)) | |
2761 | { | |
2762 | /* If we determine the LWP stopped for a SW breakpoint, | |
2763 | trust it. Particularly don't check watchpoint | |
7da6a5b9 | 2764 | registers, because, at least on s390, we'd find |
e7ad2f14 PA |
2765 | stopped-by-watchpoint as long as there's a watchpoint |
2766 | set. */ | |
faf09f01 | 2767 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
faf09f01 | 2768 | } |
e7ad2f14 | 2769 | else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) |
faf09f01 | 2770 | { |
e7ad2f14 PA |
2771 | /* This can indicate either a hardware breakpoint or |
2772 | hardware watchpoint. Check debug registers. */ | |
2773 | if (!check_stopped_by_watchpoint (lp)) | |
2774 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; | |
faf09f01 | 2775 | } |
2bf6fb9d PA |
2776 | else if (siginfo.si_code == TRAP_TRACE) |
2777 | { | |
9327494e | 2778 | linux_nat_debug_printf ("%s stopped by trace", |
e53c95d4 | 2779 | lp->ptid.to_string ().c_str ()); |
e7ad2f14 PA |
2780 | |
2781 | /* We may have single stepped an instruction that | |
2782 | triggered a watchpoint. In that case, on some | |
2783 | architectures (such as x86), instead of TRAP_HWBKPT, | |
2784 | si_code indicates TRAP_TRACE, and we need to check | |
2785 | the debug registers separately. */ | |
2786 | check_stopped_by_watchpoint (lp); | |
2bf6fb9d | 2787 | } |
faf09f01 PA |
2788 | } |
2789 | } | |
e7ad2f14 PA |
2790 | |
2791 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT) | |
2792 | { | |
9327494e | 2793 | linux_nat_debug_printf ("%s stopped by software breakpoint", |
e53c95d4 | 2794 | lp->ptid.to_string ().c_str ()); |
710151dd PA |
2795 | |
2796 | /* Back up the PC if necessary. */ | |
9c02b525 PA |
2797 | if (pc != sw_bp_pc) |
2798 | regcache_write_pc (regcache, sw_bp_pc); | |
515630c5 | 2799 | |
e7ad2f14 PA |
2800 | /* Update this so we record the correct stop PC below. */ |
2801 | pc = sw_bp_pc; | |
710151dd | 2802 | } |
e7ad2f14 | 2803 | else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) |
9c02b525 | 2804 | { |
9327494e | 2805 | linux_nat_debug_printf ("%s stopped by hardware breakpoint", |
e53c95d4 | 2806 | lp->ptid.to_string ().c_str ()); |
e7ad2f14 PA |
2807 | } |
2808 | else if (lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT) | |
2809 | { | |
9327494e | 2810 | linux_nat_debug_printf ("%s stopped by hardware watchpoint", |
e53c95d4 | 2811 | lp->ptid.to_string ().c_str ()); |
9c02b525 | 2812 | } |
d6b0e80f | 2813 | |
e7ad2f14 | 2814 | lp->stop_pc = pc; |
d6b0e80f AC |
2815 | } |
2816 | ||
faf09f01 PA |
2817 | |
2818 | /* Returns true if the LWP had stopped for a software breakpoint. */ | |
2819 | ||
57810aa7 | 2820 | bool |
f6ac5f3d | 2821 | linux_nat_target::stopped_by_sw_breakpoint () |
faf09f01 PA |
2822 | { |
2823 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2824 | ||
2825 | gdb_assert (lp != NULL); | |
2826 | ||
2827 | return lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2828 | } | |
2829 | ||
2830 | /* Implement the supports_stopped_by_sw_breakpoint method. */ | |
2831 | ||
57810aa7 | 2832 | bool |
f6ac5f3d | 2833 | linux_nat_target::supports_stopped_by_sw_breakpoint () |
faf09f01 | 2834 | { |
5739a1b9 | 2835 | return true; |
faf09f01 PA |
2836 | } |
2837 | ||
2838 | /* Returns true if the LWP had stopped for a hardware | |
2839 | breakpoint/watchpoint. */ | |
2840 | ||
57810aa7 | 2841 | bool |
f6ac5f3d | 2842 | linux_nat_target::stopped_by_hw_breakpoint () |
faf09f01 PA |
2843 | { |
2844 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2845 | ||
2846 | gdb_assert (lp != NULL); | |
2847 | ||
2848 | return lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT; | |
2849 | } | |
2850 | ||
2851 | /* Implement the supports_stopped_by_hw_breakpoint method. */ | |
2852 | ||
57810aa7 | 2853 | bool |
f6ac5f3d | 2854 | linux_nat_target::supports_stopped_by_hw_breakpoint () |
faf09f01 | 2855 | { |
5739a1b9 | 2856 | return true; |
faf09f01 PA |
2857 | } |
2858 | ||
d6b0e80f AC |
2859 | /* Select one LWP out of those that have events pending. */ |
2860 | ||
2861 | static void | |
d90e17a7 | 2862 | select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
d6b0e80f AC |
2863 | { |
2864 | int num_events = 0; | |
2865 | int random_selector; | |
9c02b525 | 2866 | struct lwp_info *event_lp = NULL; |
d6b0e80f | 2867 | |
ac264b3b | 2868 | /* Record the wait status for the original LWP. */ |
d6b0e80f AC |
2869 | (*orig_lp)->status = *status; |
2870 | ||
9c02b525 PA |
2871 | /* In all-stop, give preference to the LWP that is being |
2872 | single-stepped. There will be at most one, and it will be the | |
2873 | LWP that the core is most interested in. If we didn't do this, | |
2874 | then we'd have to handle pending step SIGTRAPs somehow in case | |
2875 | the core later continues the previously-stepped thread, as | |
2876 | otherwise we'd report the pending SIGTRAP then, and the core, not | |
2877 | having stepped the thread, wouldn't understand what the trap was | |
2878 | for, and therefore would report it to the user as a random | |
2879 | signal. */ | |
fbea99ea | 2880 | if (!target_is_non_stop_p ()) |
d6b0e80f | 2881 | { |
d3a70e03 | 2882 | event_lp = iterate_over_lwps (filter, select_singlestep_lwp_callback); |
9c02b525 PA |
2883 | if (event_lp != NULL) |
2884 | { | |
9327494e | 2885 | linux_nat_debug_printf ("Select single-step %s", |
e53c95d4 | 2886 | event_lp->ptid.to_string ().c_str ()); |
9c02b525 | 2887 | } |
d6b0e80f | 2888 | } |
9c02b525 PA |
2889 | |
2890 | if (event_lp == NULL) | |
d6b0e80f | 2891 | { |
9c02b525 | 2892 | /* Pick one at random, out of those which have had events. */ |
d6b0e80f | 2893 | |
9c02b525 | 2894 | /* First see how many events we have. */ |
d3a70e03 TT |
2895 | iterate_over_lwps (filter, |
2896 | [&] (struct lwp_info *info) | |
2897 | { | |
2898 | return count_events_callback (info, &num_events); | |
2899 | }); | |
8bf3b159 | 2900 | gdb_assert (num_events > 0); |
d6b0e80f | 2901 | |
9c02b525 PA |
2902 | /* Now randomly pick a LWP out of those that have had |
2903 | events. */ | |
d6b0e80f AC |
2904 | random_selector = (int) |
2905 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
2906 | ||
9327494e SM |
2907 | if (num_events > 1) |
2908 | linux_nat_debug_printf ("Found %d events, selecting #%d", | |
2909 | num_events, random_selector); | |
d6b0e80f | 2910 | |
d3a70e03 TT |
2911 | event_lp |
2912 | = (iterate_over_lwps | |
2913 | (filter, | |
2914 | [&] (struct lwp_info *info) | |
2915 | { | |
2916 | return select_event_lwp_callback (info, | |
2917 | &random_selector); | |
2918 | })); | |
d6b0e80f AC |
2919 | } |
2920 | ||
2921 | if (event_lp != NULL) | |
2922 | { | |
2923 | /* Switch the event LWP. */ | |
2924 | *orig_lp = event_lp; | |
2925 | *status = event_lp->status; | |
2926 | } | |
2927 | ||
2928 | /* Flush the wait status for the event LWP. */ | |
2929 | (*orig_lp)->status = 0; | |
2930 | } | |
2931 | ||
2932 | /* Return non-zero if LP has been resumed. */ | |
2933 | ||
2934 | static int | |
d3a70e03 | 2935 | resumed_callback (struct lwp_info *lp) |
d6b0e80f AC |
2936 | { |
2937 | return lp->resumed; | |
2938 | } | |
2939 | ||
02f3fc28 | 2940 | /* Check if we should go on and pass this event to common code. |
12d9289a | 2941 | |
897608ed SM |
2942 | If so, save the status to the lwp_info structure associated to LWPID. */ |
2943 | ||
2944 | static void | |
9c02b525 | 2945 | linux_nat_filter_event (int lwpid, int status) |
02f3fc28 PA |
2946 | { |
2947 | struct lwp_info *lp; | |
89a5711c | 2948 | int event = linux_ptrace_get_extended_event (status); |
02f3fc28 | 2949 | |
f2907e49 | 2950 | lp = find_lwp_pid (ptid_t (lwpid)); |
02f3fc28 | 2951 | |
1abeb1e9 PA |
2952 | /* Check for events reported by anything not in our LWP list. */ |
2953 | if (lp == nullptr) | |
0e5bf2a8 | 2954 | { |
1abeb1e9 PA |
2955 | if (WIFSTOPPED (status)) |
2956 | { | |
2957 | if (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC) | |
2958 | { | |
2959 | /* A non-leader thread exec'ed after we've seen the | |
2960 | leader zombie, and removed it from our lists (in | |
2961 | check_zombie_leaders). The non-leader thread changes | |
2962 | its tid to the tgid. */ | |
2963 | linux_nat_debug_printf | |
2964 | ("Re-adding thread group leader LWP %d after exec.", | |
2965 | lwpid); | |
0e5bf2a8 | 2966 | |
1abeb1e9 PA |
2967 | lp = add_lwp (ptid_t (lwpid, lwpid)); |
2968 | lp->stopped = 1; | |
2969 | lp->resumed = 1; | |
2970 | add_thread (linux_target, lp->ptid); | |
2971 | } | |
2972 | else | |
2973 | { | |
2974 | /* A process we are controlling has forked and the new | |
2975 | child's stop was reported to us by the kernel. Save | |
2976 | its PID and go back to waiting for the fork event to | |
2977 | be reported - the stopped process might be returned | |
2978 | from waitpid before or after the fork event is. */ | |
2979 | linux_nat_debug_printf | |
2980 | ("Saving LWP %d status %s in stopped_pids list", | |
2981 | lwpid, status_to_str (status).c_str ()); | |
2982 | add_to_pid_list (&stopped_pids, lwpid, status); | |
2983 | } | |
2984 | } | |
2985 | else | |
2986 | { | |
2987 | /* Don't report an event for the exit of an LWP not in our | |
2988 | list, i.e. not part of any inferior we're debugging. | |
2989 | This can happen if we detach from a program we originally | |
6cf20c46 PA |
2990 | forked and then it exits. However, note that we may have |
2991 | earlier deleted a leader of an inferior we're debugging, | |
2992 | in check_zombie_leaders. Re-add it back here if so. */ | |
2993 | for (inferior *inf : all_inferiors (linux_target)) | |
2994 | { | |
2995 | if (inf->pid == lwpid) | |
2996 | { | |
2997 | linux_nat_debug_printf | |
2998 | ("Re-adding thread group leader LWP %d after exit.", | |
2999 | lwpid); | |
3000 | ||
3001 | lp = add_lwp (ptid_t (lwpid, lwpid)); | |
3002 | lp->resumed = 1; | |
3003 | add_thread (linux_target, lp->ptid); | |
3004 | break; | |
3005 | } | |
3006 | } | |
1abeb1e9 | 3007 | } |
0e5bf2a8 | 3008 | |
1abeb1e9 PA |
3009 | if (lp == nullptr) |
3010 | return; | |
02f3fc28 PA |
3011 | } |
3012 | ||
8817a6f2 PA |
3013 | /* This LWP is stopped now. (And if dead, this prevents it from |
3014 | ever being continued.) */ | |
3015 | lp->stopped = 1; | |
3016 | ||
8784d563 PA |
3017 | if (WIFSTOPPED (status) && lp->must_set_ptrace_flags) |
3018 | { | |
5b6d1e4f | 3019 | inferior *inf = find_inferior_pid (linux_target, lp->ptid.pid ()); |
de0d863e | 3020 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 3021 | |
e38504b3 | 3022 | linux_enable_event_reporting (lp->ptid.lwp (), options); |
8784d563 PA |
3023 | lp->must_set_ptrace_flags = 0; |
3024 | } | |
3025 | ||
ca2163eb PA |
3026 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
3027 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
3028 | { | |
3029 | /* No longer need the sysgood bit. The ptrace event ends up | |
3030 | recorded in lp->waitstatus if we care for it. We can carry | |
3031 | on handling the event like a regular SIGTRAP from here | |
3032 | on. */ | |
3033 | status = W_STOPCODE (SIGTRAP); | |
3034 | if (linux_handle_syscall_trap (lp, 0)) | |
897608ed | 3035 | return; |
ca2163eb | 3036 | } |
bfd09d20 JS |
3037 | else |
3038 | { | |
3039 | /* Almost all other ptrace-stops are known to be outside of system | |
3040 | calls, with further exceptions in linux_handle_extended_wait. */ | |
3041 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
3042 | } | |
02f3fc28 | 3043 | |
ca2163eb | 3044 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
3045 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
3046 | && linux_is_extended_waitstatus (status)) | |
02f3fc28 | 3047 | { |
9327494e SM |
3048 | linux_nat_debug_printf ("Handling extended status 0x%06x", status); |
3049 | ||
4dd63d48 | 3050 | if (linux_handle_extended_wait (lp, status)) |
897608ed | 3051 | return; |
02f3fc28 PA |
3052 | } |
3053 | ||
3054 | /* Check if the thread has exited. */ | |
9c02b525 PA |
3055 | if (WIFEXITED (status) || WIFSIGNALED (status)) |
3056 | { | |
a51e14ef | 3057 | if (!report_exit_events_for (lp) && !is_leader (lp)) |
02f3fc28 | 3058 | { |
9327494e | 3059 | linux_nat_debug_printf ("%s exited.", |
e53c95d4 | 3060 | lp->ptid.to_string ().c_str ()); |
9c02b525 | 3061 | |
6cf20c46 | 3062 | /* If this was not the leader exiting, then the exit signal |
4a6ed09b PA |
3063 | was not the end of the debugged application and should be |
3064 | ignored. */ | |
3065 | exit_lwp (lp); | |
897608ed | 3066 | return; |
02f3fc28 PA |
3067 | } |
3068 | ||
77598427 PA |
3069 | /* Note that even if the leader was ptrace-stopped, it can still |
3070 | exit, if e.g., some other thread brings down the whole | |
3071 | process (calls `exit'). So don't assert that the lwp is | |
3072 | resumed. */ | |
9327494e SM |
3073 | linux_nat_debug_printf ("LWP %ld exited (resumed=%d)", |
3074 | lp->ptid.lwp (), lp->resumed); | |
02f3fc28 | 3075 | |
3d2d2172 | 3076 | mark_lwp_dead (lp, status); |
897608ed | 3077 | return; |
02f3fc28 PA |
3078 | } |
3079 | ||
02f3fc28 PA |
3080 | /* Make sure we don't report a SIGSTOP that we sent ourselves in |
3081 | an attempt to stop an LWP. */ | |
3082 | if (lp->signalled | |
3083 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) | |
3084 | { | |
02f3fc28 PA |
3085 | lp->signalled = 0; |
3086 | ||
2bf6fb9d | 3087 | if (lp->last_resume_kind == resume_stop) |
25289eb2 | 3088 | { |
9327494e | 3089 | linux_nat_debug_printf ("resume_stop SIGSTOP caught for %s.", |
e53c95d4 | 3090 | lp->ptid.to_string ().c_str ()); |
2bf6fb9d PA |
3091 | } |
3092 | else | |
3093 | { | |
3094 | /* This is a delayed SIGSTOP. Filter out the event. */ | |
02f3fc28 | 3095 | |
9327494e SM |
3096 | linux_nat_debug_printf |
3097 | ("%s %s, 0, 0 (discard delayed SIGSTOP)", | |
3098 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 3099 | lp->ptid.to_string ().c_str ()); |
02f3fc28 | 3100 | |
2bf6fb9d | 3101 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
25289eb2 | 3102 | gdb_assert (lp->resumed); |
897608ed | 3103 | return; |
25289eb2 | 3104 | } |
02f3fc28 PA |
3105 | } |
3106 | ||
57380f4e DJ |
3107 | /* Make sure we don't report a SIGINT that we have already displayed |
3108 | for another thread. */ | |
3109 | if (lp->ignore_sigint | |
3110 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) | |
3111 | { | |
9327494e | 3112 | linux_nat_debug_printf ("Delayed SIGINT caught for %s.", |
e53c95d4 | 3113 | lp->ptid.to_string ().c_str ()); |
57380f4e DJ |
3114 | |
3115 | /* This is a delayed SIGINT. */ | |
3116 | lp->ignore_sigint = 0; | |
3117 | ||
8a99810d | 3118 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
9327494e SM |
3119 | linux_nat_debug_printf ("%s %s, 0, 0 (discard SIGINT)", |
3120 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 3121 | lp->ptid.to_string ().c_str ()); |
57380f4e DJ |
3122 | gdb_assert (lp->resumed); |
3123 | ||
3124 | /* Discard the event. */ | |
897608ed | 3125 | return; |
57380f4e DJ |
3126 | } |
3127 | ||
9c02b525 PA |
3128 | /* Don't report signals that GDB isn't interested in, such as |
3129 | signals that are neither printed nor stopped upon. Stopping all | |
7da6a5b9 | 3130 | threads can be a bit time-consuming, so if we want decent |
9c02b525 PA |
3131 | performance with heavily multi-threaded programs, especially when |
3132 | they're using a high frequency timer, we'd better avoid it if we | |
3133 | can. */ | |
3134 | if (WIFSTOPPED (status)) | |
3135 | { | |
3136 | enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status)); | |
3137 | ||
fbea99ea | 3138 | if (!target_is_non_stop_p ()) |
9c02b525 PA |
3139 | { |
3140 | /* Only do the below in all-stop, as we currently use SIGSTOP | |
3141 | to implement target_stop (see linux_nat_stop) in | |
3142 | non-stop. */ | |
3143 | if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0) | |
3144 | { | |
3145 | /* If ^C/BREAK is typed at the tty/console, SIGINT gets | |
3146 | forwarded to the entire process group, that is, all LWPs | |
3147 | will receive it - unless they're using CLONE_THREAD to | |
3148 | share signals. Since we only want to report it once, we | |
3149 | mark it as ignored for all LWPs except this one. */ | |
d3a70e03 | 3150 | iterate_over_lwps (ptid_t (lp->ptid.pid ()), set_ignore_sigint); |
9c02b525 PA |
3151 | lp->ignore_sigint = 0; |
3152 | } | |
3153 | else | |
3154 | maybe_clear_ignore_sigint (lp); | |
3155 | } | |
3156 | ||
3157 | /* When using hardware single-step, we need to report every signal. | |
c9587f88 | 3158 | Otherwise, signals in pass_mask may be short-circuited |
d8c06f22 AB |
3159 | except signals that might be caused by a breakpoint, or SIGSTOP |
3160 | if we sent the SIGSTOP and are waiting for it to arrive. */ | |
9c02b525 | 3161 | if (!lp->step |
c9587f88 | 3162 | && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status)) |
d8c06f22 | 3163 | && (WSTOPSIG (status) != SIGSTOP |
9213a6d7 | 3164 | || !linux_target->find_thread (lp->ptid)->stop_requested) |
c9587f88 | 3165 | && !linux_wstatus_maybe_breakpoint (status)) |
9c02b525 PA |
3166 | { |
3167 | linux_resume_one_lwp (lp, lp->step, signo); | |
9327494e SM |
3168 | linux_nat_debug_printf |
3169 | ("%s %s, %s (preempt 'handle')", | |
3170 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 3171 | lp->ptid.to_string ().c_str (), |
9327494e SM |
3172 | (signo != GDB_SIGNAL_0 |
3173 | ? strsignal (gdb_signal_to_host (signo)) : "0")); | |
897608ed | 3174 | return; |
9c02b525 PA |
3175 | } |
3176 | } | |
3177 | ||
02f3fc28 PA |
3178 | /* An interesting event. */ |
3179 | gdb_assert (lp); | |
ca2163eb | 3180 | lp->status = status; |
e7ad2f14 | 3181 | save_stop_reason (lp); |
02f3fc28 PA |
3182 | } |
3183 | ||
0e5bf2a8 PA |
3184 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
3185 | their exits until all other threads in the group have exited. */ | |
3186 | ||
3187 | static void | |
3188 | check_zombie_leaders (void) | |
3189 | { | |
08036331 | 3190 | for (inferior *inf : all_inferiors ()) |
0e5bf2a8 PA |
3191 | { |
3192 | struct lwp_info *leader_lp; | |
3193 | ||
3194 | if (inf->pid == 0) | |
3195 | continue; | |
3196 | ||
f2907e49 | 3197 | leader_lp = find_lwp_pid (ptid_t (inf->pid)); |
0e5bf2a8 PA |
3198 | if (leader_lp != NULL |
3199 | /* Check if there are other threads in the group, as we may | |
6cf20c46 PA |
3200 | have raced with the inferior simply exiting. Note this |
3201 | isn't a watertight check. If the inferior is | |
3202 | multi-threaded and is exiting, it may be we see the | |
3203 | leader as zombie before we reap all the non-leader | |
3204 | threads. See comments below. */ | |
0e5bf2a8 | 3205 | && num_lwps (inf->pid) > 1 |
5f572dec | 3206 | && linux_proc_pid_is_zombie (inf->pid)) |
0e5bf2a8 | 3207 | { |
6cf20c46 PA |
3208 | /* A zombie leader in a multi-threaded program can mean one |
3209 | of three things: | |
3210 | ||
3211 | #1 - Only the leader exited, not the whole program, e.g., | |
3212 | with pthread_exit. Since we can't reap the leader's exit | |
3213 | status until all other threads are gone and reaped too, | |
3214 | we want to delete the zombie leader right away, as it | |
3215 | can't be debugged, we can't read its registers, etc. | |
3216 | This is the main reason we check for zombie leaders | |
3217 | disappearing. | |
3218 | ||
3219 | #2 - The whole thread-group/process exited (a group exit, | |
3220 | via e.g. exit(3), and there is (or will be shortly) an | |
3221 | exit reported for each thread in the process, and then | |
3222 | finally an exit for the leader once the non-leaders are | |
3223 | reaped. | |
3224 | ||
3225 | #3 - There are 3 or more threads in the group, and a | |
3226 | thread other than the leader exec'd. See comments on | |
3227 | exec events at the top of the file. | |
3228 | ||
3229 | Ideally we would never delete the leader for case #2. | |
3230 | Instead, we want to collect the exit status of each | |
3231 | non-leader thread, and then finally collect the exit | |
3232 | status of the leader as normal and use its exit code as | |
3233 | whole-process exit code. Unfortunately, there's no | |
3234 | race-free way to distinguish cases #1 and #2. We can't | |
3235 | assume the exit events for the non-leaders threads are | |
3236 | already pending in the kernel, nor can we assume the | |
3237 | non-leader threads are in zombie state already. Between | |
3238 | the leader becoming zombie and the non-leaders exiting | |
3239 | and becoming zombie themselves, there's a small time | |
3240 | window, so such a check would be racy. Temporarily | |
3241 | pausing all threads and checking to see if all threads | |
3242 | exit or not before re-resuming them would work in the | |
3243 | case that all threads are running right now, but it | |
3244 | wouldn't work if some thread is currently already | |
3245 | ptrace-stopped, e.g., due to scheduler-locking. | |
3246 | ||
3247 | So what we do is we delete the leader anyhow, and then | |
3248 | later on when we see its exit status, we re-add it back. | |
3249 | We also make sure that we only report a whole-process | |
3250 | exit when we see the leader exiting, as opposed to when | |
3251 | the last LWP in the LWP list exits, which can be a | |
3252 | non-leader if we deleted the leader here. */ | |
9327494e | 3253 | linux_nat_debug_printf ("Thread group leader %d zombie " |
6cf20c46 PA |
3254 | "(it exited, or another thread execd), " |
3255 | "deleting it.", | |
9327494e | 3256 | inf->pid); |
0e5bf2a8 PA |
3257 | exit_lwp (leader_lp); |
3258 | } | |
3259 | } | |
3260 | } | |
3261 | ||
a51e14ef PA |
3262 | /* Convenience function that is called when we're about to return an |
3263 | event to the core. If the event is an exit or signalled event, | |
3264 | then this decides whether to report it as process-wide event, as a | |
3265 | thread exit event, or to suppress it. All other event kinds are | |
3266 | passed through unmodified. */ | |
aa01bd36 PA |
3267 | |
3268 | static ptid_t | |
3269 | filter_exit_event (struct lwp_info *event_child, | |
3270 | struct target_waitstatus *ourstatus) | |
3271 | { | |
3272 | ptid_t ptid = event_child->ptid; | |
3273 | ||
a51e14ef PA |
3274 | /* Note we must filter TARGET_WAITKIND_SIGNALLED as well, otherwise |
3275 | if a non-leader thread exits with a signal, we'd report it to the | |
3276 | core which would interpret it as the whole-process exiting. | |
3277 | There is no TARGET_WAITKIND_THREAD_SIGNALLED event kind. */ | |
3278 | if (ourstatus->kind () != TARGET_WAITKIND_EXITED | |
3279 | && ourstatus->kind () != TARGET_WAITKIND_SIGNALLED) | |
3280 | return ptid; | |
3281 | ||
6cf20c46 | 3282 | if (!is_leader (event_child)) |
aa01bd36 | 3283 | { |
a51e14ef | 3284 | if (report_exit_events_for (event_child)) |
7730e5c6 PA |
3285 | { |
3286 | ourstatus->set_thread_exited (0); | |
3287 | /* Delete lwp, but not thread_info, infrun will need it to | |
3288 | process the event. */ | |
3289 | exit_lwp (event_child, false); | |
3290 | } | |
aa01bd36 | 3291 | else |
7730e5c6 PA |
3292 | { |
3293 | ourstatus->set_ignore (); | |
3294 | exit_lwp (event_child); | |
3295 | } | |
aa01bd36 PA |
3296 | } |
3297 | ||
3298 | return ptid; | |
3299 | } | |
3300 | ||
d6b0e80f | 3301 | static ptid_t |
f6ac5f3d | 3302 | linux_nat_wait_1 (ptid_t ptid, struct target_waitstatus *ourstatus, |
b60cea74 | 3303 | target_wait_flags target_options) |
d6b0e80f | 3304 | { |
b26b06dd AB |
3305 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
3306 | ||
fc9b8e47 | 3307 | sigset_t prev_mask; |
4b60df3d | 3308 | enum resume_kind last_resume_kind; |
12d9289a | 3309 | struct lwp_info *lp; |
12d9289a | 3310 | int status; |
d6b0e80f | 3311 | |
f973ed9c DJ |
3312 | /* The first time we get here after starting a new inferior, we may |
3313 | not have added it to the LWP list yet - this is the earliest | |
3314 | moment at which we know its PID. */ | |
677c92fe | 3315 | if (ptid.is_pid () && find_lwp_pid (ptid) == nullptr) |
f973ed9c | 3316 | { |
677c92fe | 3317 | ptid_t lwp_ptid (ptid.pid (), ptid.pid ()); |
27c9d204 | 3318 | |
677c92fe SM |
3319 | /* Upgrade the main thread's ptid. */ |
3320 | thread_change_ptid (linux_target, ptid, lwp_ptid); | |
3321 | lp = add_initial_lwp (lwp_ptid); | |
f973ed9c DJ |
3322 | lp->resumed = 1; |
3323 | } | |
3324 | ||
12696c10 | 3325 | /* Make sure SIGCHLD is blocked until the sigsuspend below. */ |
7feb7d06 | 3326 | block_child_signals (&prev_mask); |
d6b0e80f | 3327 | |
d6b0e80f | 3328 | /* First check if there is a LWP with a wait status pending. */ |
d3a70e03 | 3329 | lp = iterate_over_lwps (ptid, status_callback); |
8a99810d | 3330 | if (lp != NULL) |
d6b0e80f | 3331 | { |
9327494e | 3332 | linux_nat_debug_printf ("Using pending wait status %s for %s.", |
57573e54 | 3333 | pending_status_str (lp).c_str (), |
e53c95d4 | 3334 | lp->ptid.to_string ().c_str ()); |
d6b0e80f AC |
3335 | } |
3336 | ||
9c02b525 PA |
3337 | /* But if we don't find a pending event, we'll have to wait. Always |
3338 | pull all events out of the kernel. We'll randomly select an | |
3339 | event LWP out of all that have events, to prevent starvation. */ | |
7feb7d06 | 3340 | |
d90e17a7 | 3341 | while (lp == NULL) |
d6b0e80f AC |
3342 | { |
3343 | pid_t lwpid; | |
3344 | ||
0e5bf2a8 PA |
3345 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
3346 | quirks: | |
3347 | ||
3348 | - If the thread group leader exits while other threads in the | |
3349 | thread group still exist, waitpid(TGID, ...) hangs. That | |
3350 | waitpid won't return an exit status until the other threads | |
85102364 | 3351 | in the group are reaped. |
0e5bf2a8 PA |
3352 | |
3353 | - When a non-leader thread execs, that thread just vanishes | |
3354 | without reporting an exit (so we'd hang if we waited for it | |
3355 | explicitly in that case). The exec event is reported to | |
3356 | the TGID pid. */ | |
3357 | ||
3358 | errno = 0; | |
4a6ed09b | 3359 | lwpid = my_waitpid (-1, &status, __WALL | WNOHANG); |
0e5bf2a8 | 3360 | |
9327494e SM |
3361 | linux_nat_debug_printf ("waitpid(-1, ...) returned %d, %s", |
3362 | lwpid, | |
3363 | errno ? safe_strerror (errno) : "ERRNO-OK"); | |
b84876c2 | 3364 | |
d6b0e80f AC |
3365 | if (lwpid > 0) |
3366 | { | |
9327494e | 3367 | linux_nat_debug_printf ("waitpid %ld received %s", |
8d06918f SM |
3368 | (long) lwpid, |
3369 | status_to_str (status).c_str ()); | |
d6b0e80f | 3370 | |
9c02b525 | 3371 | linux_nat_filter_event (lwpid, status); |
0e5bf2a8 PA |
3372 | /* Retry until nothing comes out of waitpid. A single |
3373 | SIGCHLD can indicate more than one child stopped. */ | |
3374 | continue; | |
d6b0e80f AC |
3375 | } |
3376 | ||
20ba1ce6 PA |
3377 | /* Now that we've pulled all events out of the kernel, resume |
3378 | LWPs that don't have an interesting event to report. */ | |
3379 | iterate_over_lwps (minus_one_ptid, | |
d3a70e03 TT |
3380 | [] (struct lwp_info *info) |
3381 | { | |
3382 | return resume_stopped_resumed_lwps (info, minus_one_ptid); | |
3383 | }); | |
20ba1ce6 PA |
3384 | |
3385 | /* ... and find an LWP with a status to report to the core, if | |
3386 | any. */ | |
d3a70e03 | 3387 | lp = iterate_over_lwps (ptid, status_callback); |
9c02b525 PA |
3388 | if (lp != NULL) |
3389 | break; | |
3390 | ||
0e5bf2a8 PA |
3391 | /* Check for zombie thread group leaders. Those can't be reaped |
3392 | until all other threads in the thread group are. */ | |
3393 | check_zombie_leaders (); | |
d6b0e80f | 3394 | |
0e5bf2a8 PA |
3395 | /* If there are no resumed children left, bail. We'd be stuck |
3396 | forever in the sigsuspend call below otherwise. */ | |
d3a70e03 | 3397 | if (iterate_over_lwps (ptid, resumed_callback) == NULL) |
0e5bf2a8 | 3398 | { |
9327494e | 3399 | linux_nat_debug_printf ("exit (no resumed LWP)"); |
b84876c2 | 3400 | |
183be222 | 3401 | ourstatus->set_no_resumed (); |
b84876c2 | 3402 | |
0e5bf2a8 PA |
3403 | restore_child_signals_mask (&prev_mask); |
3404 | return minus_one_ptid; | |
d6b0e80f | 3405 | } |
28736962 | 3406 | |
0e5bf2a8 PA |
3407 | /* No interesting event to report to the core. */ |
3408 | ||
3409 | if (target_options & TARGET_WNOHANG) | |
3410 | { | |
b26b06dd | 3411 | linux_nat_debug_printf ("no interesting events found"); |
28736962 | 3412 | |
183be222 | 3413 | ourstatus->set_ignore (); |
28736962 PA |
3414 | restore_child_signals_mask (&prev_mask); |
3415 | return minus_one_ptid; | |
3416 | } | |
d6b0e80f AC |
3417 | |
3418 | /* We shouldn't end up here unless we want to try again. */ | |
d90e17a7 | 3419 | gdb_assert (lp == NULL); |
0e5bf2a8 PA |
3420 | |
3421 | /* Block until we get an event reported with SIGCHLD. */ | |
9c3a5d93 | 3422 | wait_for_signal (); |
d6b0e80f AC |
3423 | } |
3424 | ||
d6b0e80f | 3425 | gdb_assert (lp); |
3d2d2172 | 3426 | gdb_assert (lp->stopped); |
d6b0e80f | 3427 | |
ca2163eb PA |
3428 | status = lp->status; |
3429 | lp->status = 0; | |
3430 | ||
fbea99ea | 3431 | if (!target_is_non_stop_p ()) |
4c28f408 PA |
3432 | { |
3433 | /* Now stop all other LWP's ... */ | |
d3a70e03 | 3434 | iterate_over_lwps (minus_one_ptid, stop_callback); |
4c28f408 PA |
3435 | |
3436 | /* ... and wait until all of them have reported back that | |
3437 | they're no longer running. */ | |
d3a70e03 | 3438 | iterate_over_lwps (minus_one_ptid, stop_wait_callback); |
9c02b525 PA |
3439 | } |
3440 | ||
3441 | /* If we're not waiting for a specific LWP, choose an event LWP from | |
3442 | among those that have had events. Giving equal priority to all | |
3443 | LWPs that have had events helps prevent starvation. */ | |
d7e15655 | 3444 | if (ptid == minus_one_ptid || ptid.is_pid ()) |
9c02b525 PA |
3445 | select_event_lwp (ptid, &lp, &status); |
3446 | ||
3447 | gdb_assert (lp != NULL); | |
3448 | ||
9c02b525 PA |
3449 | /* We'll need this to determine whether to report a SIGSTOP as |
3450 | GDB_SIGNAL_0. Need to take a copy because resume_clear_callback | |
3451 | clears it. */ | |
3452 | last_resume_kind = lp->last_resume_kind; | |
4b60df3d | 3453 | |
fbea99ea | 3454 | if (!target_is_non_stop_p ()) |
9c02b525 | 3455 | { |
e3e9f5a2 PA |
3456 | /* In all-stop, from the core's perspective, all LWPs are now |
3457 | stopped until a new resume action is sent over. */ | |
d3a70e03 | 3458 | iterate_over_lwps (minus_one_ptid, resume_clear_callback); |
e3e9f5a2 PA |
3459 | } |
3460 | else | |
25289eb2 | 3461 | { |
d3a70e03 | 3462 | resume_clear_callback (lp); |
25289eb2 | 3463 | } |
d6b0e80f | 3464 | |
135340af | 3465 | if (linux_target->low_status_is_event (status)) |
d6b0e80f | 3466 | { |
9327494e | 3467 | linux_nat_debug_printf ("trap ptid is %s.", |
e53c95d4 | 3468 | lp->ptid.to_string ().c_str ()); |
d6b0e80f | 3469 | } |
d6b0e80f | 3470 | |
183be222 | 3471 | if (lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE) |
d6b0e80f AC |
3472 | { |
3473 | *ourstatus = lp->waitstatus; | |
183be222 | 3474 | lp->waitstatus.set_ignore (); |
d6b0e80f AC |
3475 | } |
3476 | else | |
7509b829 | 3477 | *ourstatus = host_status_to_waitstatus (status); |
d6b0e80f | 3478 | |
b26b06dd | 3479 | linux_nat_debug_printf ("event found"); |
b84876c2 | 3480 | |
7feb7d06 | 3481 | restore_child_signals_mask (&prev_mask); |
1e225492 | 3482 | |
4b60df3d | 3483 | if (last_resume_kind == resume_stop |
183be222 | 3484 | && ourstatus->kind () == TARGET_WAITKIND_STOPPED |
25289eb2 PA |
3485 | && WSTOPSIG (status) == SIGSTOP) |
3486 | { | |
3487 | /* A thread that has been requested to stop by GDB with | |
3488 | target_stop, and it stopped cleanly, so report as SIG0. The | |
3489 | use of SIGSTOP is an implementation detail. */ | |
183be222 | 3490 | ourstatus->set_stopped (GDB_SIGNAL_0); |
25289eb2 PA |
3491 | } |
3492 | ||
183be222 SM |
3493 | if (ourstatus->kind () == TARGET_WAITKIND_EXITED |
3494 | || ourstatus->kind () == TARGET_WAITKIND_SIGNALLED) | |
1e225492 JK |
3495 | lp->core = -1; |
3496 | else | |
2e794194 | 3497 | lp->core = linux_common_core_of_thread (lp->ptid); |
1e225492 | 3498 | |
a51e14ef | 3499 | return filter_exit_event (lp, ourstatus); |
d6b0e80f AC |
3500 | } |
3501 | ||
e3e9f5a2 PA |
3502 | /* Resume LWPs that are currently stopped without any pending status |
3503 | to report, but are resumed from the core's perspective. */ | |
3504 | ||
3505 | static int | |
d3a70e03 | 3506 | resume_stopped_resumed_lwps (struct lwp_info *lp, const ptid_t wait_ptid) |
e3e9f5a2 | 3507 | { |
74387712 | 3508 | inferior *inf = lwp_inferior (lp); |
14ec4172 | 3509 | |
8a9da63e | 3510 | if (!lp->stopped) |
4dd63d48 | 3511 | { |
9327494e | 3512 | linux_nat_debug_printf ("NOT resuming LWP %s, not stopped", |
e53c95d4 | 3513 | lp->ptid.to_string ().c_str ()); |
4dd63d48 PA |
3514 | } |
3515 | else if (!lp->resumed) | |
3516 | { | |
9327494e | 3517 | linux_nat_debug_printf ("NOT resuming LWP %s, not resumed", |
e53c95d4 | 3518 | lp->ptid.to_string ().c_str ()); |
4dd63d48 PA |
3519 | } |
3520 | else if (lwp_status_pending_p (lp)) | |
3521 | { | |
9327494e | 3522 | linux_nat_debug_printf ("NOT resuming LWP %s, has pending status", |
e53c95d4 | 3523 | lp->ptid.to_string ().c_str ()); |
4dd63d48 | 3524 | } |
8a9da63e AB |
3525 | else if (inf->vfork_child != nullptr) |
3526 | { | |
3527 | linux_nat_debug_printf ("NOT resuming LWP %s (vfork parent)", | |
3528 | lp->ptid.to_string ().c_str ()); | |
3529 | } | |
4dd63d48 | 3530 | else |
e3e9f5a2 | 3531 | { |
5b6d1e4f | 3532 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 3533 | struct gdbarch *gdbarch = regcache->arch (); |
336060f3 | 3534 | |
a70b8144 | 3535 | try |
e3e9f5a2 | 3536 | { |
23f238d3 PA |
3537 | CORE_ADDR pc = regcache_read_pc (regcache); |
3538 | int leave_stopped = 0; | |
e3e9f5a2 | 3539 | |
23f238d3 PA |
3540 | /* Don't bother if there's a breakpoint at PC that we'd hit |
3541 | immediately, and we're not waiting for this LWP. */ | |
d3a70e03 | 3542 | if (!lp->ptid.matches (wait_ptid)) |
23f238d3 | 3543 | { |
f9582a22 | 3544 | if (breakpoint_inserted_here_p (inf->aspace.get (), pc)) |
23f238d3 PA |
3545 | leave_stopped = 1; |
3546 | } | |
e3e9f5a2 | 3547 | |
23f238d3 PA |
3548 | if (!leave_stopped) |
3549 | { | |
9327494e SM |
3550 | linux_nat_debug_printf |
3551 | ("resuming stopped-resumed LWP %s at %s: step=%d", | |
e53c95d4 | 3552 | lp->ptid.to_string ().c_str (), paddress (gdbarch, pc), |
9327494e | 3553 | lp->step); |
23f238d3 PA |
3554 | |
3555 | linux_resume_one_lwp_throw (lp, lp->step, GDB_SIGNAL_0); | |
3556 | } | |
3557 | } | |
230d2906 | 3558 | catch (const gdb_exception_error &ex) |
23f238d3 PA |
3559 | { |
3560 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 3561 | throw; |
23f238d3 | 3562 | } |
e3e9f5a2 PA |
3563 | } |
3564 | ||
3565 | return 0; | |
3566 | } | |
3567 | ||
f6ac5f3d PA |
3568 | ptid_t |
3569 | linux_nat_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus, | |
b60cea74 | 3570 | target_wait_flags target_options) |
7feb7d06 | 3571 | { |
b26b06dd AB |
3572 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
3573 | ||
7feb7d06 PA |
3574 | ptid_t event_ptid; |
3575 | ||
e53c95d4 | 3576 | linux_nat_debug_printf ("[%s], [%s]", ptid.to_string ().c_str (), |
9327494e | 3577 | target_options_to_string (target_options).c_str ()); |
7feb7d06 PA |
3578 | |
3579 | /* Flush the async file first. */ | |
d9d41e78 | 3580 | if (target_is_async_p ()) |
7feb7d06 PA |
3581 | async_file_flush (); |
3582 | ||
e3e9f5a2 PA |
3583 | /* Resume LWPs that are currently stopped without any pending status |
3584 | to report, but are resumed from the core's perspective. LWPs get | |
3585 | in this state if we find them stopping at a time we're not | |
3586 | interested in reporting the event (target_wait on a | |
3587 | specific_process, for example, see linux_nat_wait_1), and | |
3588 | meanwhile the event became uninteresting. Don't bother resuming | |
3589 | LWPs we're not going to wait for if they'd stop immediately. */ | |
fbea99ea | 3590 | if (target_is_non_stop_p ()) |
d3a70e03 TT |
3591 | iterate_over_lwps (minus_one_ptid, |
3592 | [=] (struct lwp_info *info) | |
3593 | { | |
3594 | return resume_stopped_resumed_lwps (info, ptid); | |
3595 | }); | |
e3e9f5a2 | 3596 | |
f6ac5f3d | 3597 | event_ptid = linux_nat_wait_1 (ptid, ourstatus, target_options); |
7feb7d06 PA |
3598 | |
3599 | /* If we requested any event, and something came out, assume there | |
3600 | may be more. If we requested a specific lwp or process, also | |
3601 | assume there may be more. */ | |
d9d41e78 | 3602 | if (target_is_async_p () |
183be222 SM |
3603 | && ((ourstatus->kind () != TARGET_WAITKIND_IGNORE |
3604 | && ourstatus->kind () != TARGET_WAITKIND_NO_RESUMED) | |
d7e15655 | 3605 | || ptid != minus_one_ptid)) |
7feb7d06 PA |
3606 | async_file_mark (); |
3607 | ||
7feb7d06 PA |
3608 | return event_ptid; |
3609 | } | |
3610 | ||
1d2736d4 PA |
3611 | /* Kill one LWP. */ |
3612 | ||
3613 | static void | |
3614 | kill_one_lwp (pid_t pid) | |
d6b0e80f | 3615 | { |
ed731959 JK |
3616 | /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
3617 | ||
3618 | errno = 0; | |
1d2736d4 | 3619 | kill_lwp (pid, SIGKILL); |
9327494e | 3620 | |
ed731959 | 3621 | if (debug_linux_nat) |
57745c90 PA |
3622 | { |
3623 | int save_errno = errno; | |
3624 | ||
9327494e SM |
3625 | linux_nat_debug_printf |
3626 | ("kill (SIGKILL) %ld, 0, 0 (%s)", (long) pid, | |
3627 | save_errno != 0 ? safe_strerror (save_errno) : "OK"); | |
57745c90 | 3628 | } |
ed731959 JK |
3629 | |
3630 | /* Some kernels ignore even SIGKILL for processes under ptrace. */ | |
3631 | ||
d6b0e80f | 3632 | errno = 0; |
1d2736d4 | 3633 | ptrace (PTRACE_KILL, pid, 0, 0); |
d6b0e80f | 3634 | if (debug_linux_nat) |
57745c90 PA |
3635 | { |
3636 | int save_errno = errno; | |
3637 | ||
9327494e SM |
3638 | linux_nat_debug_printf |
3639 | ("PTRACE_KILL %ld, 0, 0 (%s)", (long) pid, | |
3640 | save_errno ? safe_strerror (save_errno) : "OK"); | |
57745c90 | 3641 | } |
d6b0e80f AC |
3642 | } |
3643 | ||
1d2736d4 PA |
3644 | /* Wait for an LWP to die. */ |
3645 | ||
3646 | static void | |
3647 | kill_wait_one_lwp (pid_t pid) | |
d6b0e80f | 3648 | { |
1d2736d4 | 3649 | pid_t res; |
d6b0e80f AC |
3650 | |
3651 | /* We must make sure that there are no pending events (delayed | |
3652 | SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current | |
3653 | program doesn't interfere with any following debugging session. */ | |
3654 | ||
d6b0e80f AC |
3655 | do |
3656 | { | |
1d2736d4 PA |
3657 | res = my_waitpid (pid, NULL, __WALL); |
3658 | if (res != (pid_t) -1) | |
d6b0e80f | 3659 | { |
9327494e SM |
3660 | linux_nat_debug_printf ("wait %ld received unknown.", (long) pid); |
3661 | ||
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 | ||
0d36baa9 | 3692 | /* Kill the fork/clone child of LP if it has an unfollowed child. */ |
1d2736d4 | 3693 | |
0d36baa9 PA |
3694 | static int |
3695 | kill_unfollowed_child_callback (lwp_info *lp) | |
1d2736d4 | 3696 | { |
6b09f134 | 3697 | std::optional<target_waitstatus> ws = get_pending_child_status (lp); |
0d36baa9 | 3698 | if (ws.has_value ()) |
08036331 | 3699 | { |
0d36baa9 PA |
3700 | ptid_t child_ptid = ws->child_ptid (); |
3701 | int child_pid = child_ptid.pid (); | |
3702 | int child_lwp = child_ptid.lwp (); | |
08036331 | 3703 | |
0d36baa9 PA |
3704 | kill_one_lwp (child_lwp); |
3705 | kill_wait_one_lwp (child_lwp); | |
08036331 | 3706 | |
0d36baa9 PA |
3707 | /* Let the arch-specific native code know this process is |
3708 | gone. */ | |
3709 | if (ws->kind () != TARGET_WAITKIND_THREAD_CLONED) | |
3710 | linux_target->low_forget_process (child_pid); | |
08036331 | 3711 | } |
0d36baa9 PA |
3712 | |
3713 | return 0; | |
1d2736d4 PA |
3714 | } |
3715 | ||
f6ac5f3d PA |
3716 | void |
3717 | linux_nat_target::kill () | |
d6b0e80f | 3718 | { |
0d36baa9 PA |
3719 | ptid_t pid_ptid (inferior_ptid.pid ()); |
3720 | ||
3721 | /* If we're stopped while forking/cloning and we haven't followed | |
3722 | yet, kill the child task. We need to do this first because the | |
f973ed9c | 3723 | parent will be sleeping if this is a vfork. */ |
0d36baa9 | 3724 | iterate_over_lwps (pid_ptid, kill_unfollowed_child_callback); |
f973ed9c DJ |
3725 | |
3726 | if (forks_exist_p ()) | |
7feb7d06 | 3727 | linux_fork_killall (); |
f973ed9c DJ |
3728 | else |
3729 | { | |
4c28f408 | 3730 | /* Stop all threads before killing them, since ptrace requires |
30baf67b | 3731 | that the thread is stopped to successfully PTRACE_KILL. */ |
0d36baa9 | 3732 | iterate_over_lwps (pid_ptid, stop_callback); |
4c28f408 PA |
3733 | /* ... and wait until all of them have reported back that |
3734 | they're no longer running. */ | |
0d36baa9 | 3735 | iterate_over_lwps (pid_ptid, stop_wait_callback); |
4c28f408 | 3736 | |
f973ed9c | 3737 | /* Kill all LWP's ... */ |
0d36baa9 | 3738 | iterate_over_lwps (pid_ptid, kill_callback); |
f973ed9c DJ |
3739 | |
3740 | /* ... and wait until we've flushed all events. */ | |
0d36baa9 | 3741 | iterate_over_lwps (pid_ptid, kill_wait_callback); |
f973ed9c DJ |
3742 | } |
3743 | ||
bc1e6c81 | 3744 | target_mourn_inferior (inferior_ptid); |
d6b0e80f AC |
3745 | } |
3746 | ||
f6ac5f3d PA |
3747 | void |
3748 | linux_nat_target::mourn_inferior () | |
d6b0e80f | 3749 | { |
b26b06dd AB |
3750 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
3751 | ||
e99b03dc | 3752 | int pid = inferior_ptid.pid (); |
26cb8b7c PA |
3753 | |
3754 | purge_lwp_list (pid); | |
d6b0e80f | 3755 | |
8a89ddbd | 3756 | close_proc_mem_file (pid); |
05c06f31 | 3757 | |
f973ed9c | 3758 | if (! forks_exist_p ()) |
d90e17a7 | 3759 | /* Normal case, no other forks available. */ |
f6ac5f3d | 3760 | inf_ptrace_target::mourn_inferior (); |
f973ed9c DJ |
3761 | else |
3762 | /* Multi-fork case. The current inferior_ptid has exited, but | |
3763 | there are other viable forks to debug. Delete the exiting | |
3764 | one and context-switch to the first available. */ | |
3765 | linux_fork_mourn_inferior (); | |
26cb8b7c PA |
3766 | |
3767 | /* Let the arch-specific native code know this process is gone. */ | |
135340af | 3768 | linux_target->low_forget_process (pid); |
d6b0e80f AC |
3769 | } |
3770 | ||
5b009018 PA |
3771 | /* Convert a native/host siginfo object, into/from the siginfo in the |
3772 | layout of the inferiors' architecture. */ | |
3773 | ||
3774 | static void | |
a5362b9a | 3775 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
5b009018 | 3776 | { |
135340af PA |
3777 | /* If the low target didn't do anything, then just do a straight |
3778 | memcpy. */ | |
3779 | if (!linux_target->low_siginfo_fixup (siginfo, inf_siginfo, direction)) | |
5b009018 PA |
3780 | { |
3781 | if (direction == 1) | |
a5362b9a | 3782 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
5b009018 | 3783 | else |
a5362b9a | 3784 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
5b009018 PA |
3785 | } |
3786 | } | |
3787 | ||
9b409511 | 3788 | static enum target_xfer_status |
7154e786 | 3789 | linux_xfer_siginfo (ptid_t ptid, enum target_object object, |
dda83cd7 | 3790 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
3791 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
3792 | ULONGEST *xfered_len) | |
4aa995e1 | 3793 | { |
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 | ||
4aa995e1 | 3800 | if (offset > sizeof (siginfo)) |
2ed4b548 | 3801 | return TARGET_XFER_E_IO; |
4aa995e1 | 3802 | |
7154e786 | 3803 | if (!linux_nat_get_siginfo (ptid, &siginfo)) |
2ed4b548 | 3804 | return TARGET_XFER_E_IO; |
4aa995e1 | 3805 | |
5b009018 PA |
3806 | /* When GDB is built as a 64-bit application, ptrace writes into |
3807 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
3808 | inferior with a 64-bit GDB should look the same as debugging it | |
3809 | with a 32-bit GDB, we need to convert it. GDB core always sees | |
3810 | the converted layout, so any read/write will have to be done | |
3811 | post-conversion. */ | |
3812 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
3813 | ||
4aa995e1 PA |
3814 | if (offset + len > sizeof (siginfo)) |
3815 | len = sizeof (siginfo) - offset; | |
3816 | ||
3817 | if (readbuf != NULL) | |
5b009018 | 3818 | memcpy (readbuf, inf_siginfo + offset, len); |
4aa995e1 PA |
3819 | else |
3820 | { | |
5b009018 PA |
3821 | memcpy (inf_siginfo + offset, writebuf, len); |
3822 | ||
3823 | /* Convert back to ptrace layout before flushing it out. */ | |
3824 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
3825 | ||
7154e786 | 3826 | int pid = get_ptrace_pid (ptid); |
4aa995e1 PA |
3827 | errno = 0; |
3828 | ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3829 | if (errno != 0) | |
2ed4b548 | 3830 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3831 | } |
3832 | ||
9b409511 YQ |
3833 | *xfered_len = len; |
3834 | return TARGET_XFER_OK; | |
4aa995e1 PA |
3835 | } |
3836 | ||
9b409511 | 3837 | static enum target_xfer_status |
f6ac5f3d PA |
3838 | linux_nat_xfer_osdata (enum target_object object, |
3839 | const char *annex, gdb_byte *readbuf, | |
3840 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, | |
3841 | ULONGEST *xfered_len); | |
3842 | ||
f6ac5f3d | 3843 | static enum target_xfer_status |
f9f593dd SM |
3844 | linux_proc_xfer_memory_partial (int pid, gdb_byte *readbuf, |
3845 | const gdb_byte *writebuf, ULONGEST offset, | |
3846 | LONGEST len, ULONGEST *xfered_len); | |
f6ac5f3d | 3847 | |
5e86aab8 PA |
3848 | /* Look for an LWP of PID that we know is ptrace-stopped. Returns |
3849 | NULL if none is found. */ | |
3850 | ||
3851 | static lwp_info * | |
3852 | find_stopped_lwp (int pid) | |
3853 | { | |
3854 | for (lwp_info *lp : all_lwps ()) | |
3855 | if (lp->ptid.pid () == pid | |
3856 | && lp->stopped | |
3857 | && !is_lwp_marked_dead (lp)) | |
3858 | return lp; | |
3859 | return nullptr; | |
3860 | } | |
3861 | ||
f6ac5f3d PA |
3862 | enum target_xfer_status |
3863 | linux_nat_target::xfer_partial (enum target_object object, | |
3864 | const char *annex, gdb_byte *readbuf, | |
3865 | const gdb_byte *writebuf, | |
3866 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) | |
d6b0e80f | 3867 | { |
4aa995e1 | 3868 | if (object == TARGET_OBJECT_SIGNAL_INFO) |
7154e786 | 3869 | return linux_xfer_siginfo (inferior_ptid, object, annex, readbuf, writebuf, |
9b409511 | 3870 | offset, len, xfered_len); |
4aa995e1 | 3871 | |
c35b1492 PA |
3872 | /* The target is connected but no live inferior is selected. Pass |
3873 | this request down to a lower stratum (e.g., the executable | |
3874 | file). */ | |
d7e15655 | 3875 | if (object == TARGET_OBJECT_MEMORY && inferior_ptid == null_ptid) |
9b409511 | 3876 | return TARGET_XFER_EOF; |
c35b1492 | 3877 | |
f6ac5f3d PA |
3878 | if (object == TARGET_OBJECT_AUXV) |
3879 | return memory_xfer_auxv (this, object, annex, readbuf, writebuf, | |
3880 | offset, len, xfered_len); | |
3881 | ||
3882 | if (object == TARGET_OBJECT_OSDATA) | |
3883 | return linux_nat_xfer_osdata (object, annex, readbuf, writebuf, | |
3884 | offset, len, xfered_len); | |
d6b0e80f | 3885 | |
f6ac5f3d PA |
3886 | if (object == TARGET_OBJECT_MEMORY) |
3887 | { | |
05c06f31 PA |
3888 | /* GDB calculates all addresses in the largest possible address |
3889 | width. The address width must be masked before its final use | |
3890 | by linux_proc_xfer_partial. | |
3891 | ||
3892 | Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ | |
99d9c3b9 | 3893 | int addr_bit = gdbarch_addr_bit (current_inferior ()->arch ()); |
f6ac5f3d PA |
3894 | |
3895 | if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) | |
3896 | offset &= ((ULONGEST) 1 << addr_bit) - 1; | |
f6ac5f3d | 3897 | |
dd09fe0d KS |
3898 | /* If /proc/pid/mem is writable, don't fallback to ptrace. If |
3899 | the write via /proc/pid/mem fails because the inferior execed | |
3900 | (and we haven't seen the exec event yet), a subsequent ptrace | |
3901 | poke would incorrectly write memory to the post-exec address | |
3902 | space, while the core was trying to write to the pre-exec | |
3903 | address space. */ | |
3904 | if (proc_mem_file_is_writable ()) | |
f9f593dd SM |
3905 | return linux_proc_xfer_memory_partial (inferior_ptid.pid (), readbuf, |
3906 | writebuf, offset, len, | |
3907 | xfered_len); | |
5e86aab8 PA |
3908 | |
3909 | /* Fallback to ptrace. This should only really trigger on old | |
3910 | systems. See "Accessing inferior memory" at the top. | |
3911 | ||
3912 | The target_xfer interface for memory access uses | |
3913 | inferior_ptid as sideband argument to indicate which process | |
3914 | to access. Memory access is process-wide, it is not | |
3915 | thread-specific, so inferior_ptid sometimes points at a | |
3916 | process ptid_t. If we fallback to inf_ptrace_target with | |
3917 | that inferior_ptid, then the ptrace code will do the ptrace | |
3918 | call targeting inferior_ptid.pid(), the leader LWP. That | |
3919 | may fail with ESRCH if the leader is currently running, or | |
3920 | zombie. So if we get a pid-ptid, we try to find a stopped | |
3921 | LWP to use with ptrace. | |
3922 | ||
3923 | Note that inferior_ptid may not exist in the lwp / thread / | |
3924 | inferior lists. This can happen when we're removing | |
3925 | breakpoints from a fork child that we're not going to stay | |
3926 | attached to. So if we don't find a stopped LWP, still do the | |
3927 | ptrace call, targeting the inferior_ptid we had on entry. */ | |
3928 | scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); | |
3929 | lwp_info *stopped = find_stopped_lwp (inferior_ptid.pid ()); | |
3930 | if (stopped != nullptr) | |
3931 | inferior_ptid = stopped->ptid; | |
3932 | return inf_ptrace_target::xfer_partial (object, annex, readbuf, writebuf, | |
3933 | offset, len, xfered_len); | |
05c06f31 | 3934 | } |
f6ac5f3d PA |
3935 | |
3936 | return inf_ptrace_target::xfer_partial (object, annex, readbuf, writebuf, | |
3937 | offset, len, xfered_len); | |
d6b0e80f AC |
3938 | } |
3939 | ||
57810aa7 | 3940 | bool |
f6ac5f3d | 3941 | linux_nat_target::thread_alive (ptid_t ptid) |
28439f5e | 3942 | { |
4a6ed09b PA |
3943 | /* As long as a PTID is in lwp list, consider it alive. */ |
3944 | return find_lwp_pid (ptid) != NULL; | |
28439f5e PA |
3945 | } |
3946 | ||
8a06aea7 PA |
3947 | /* Implement the to_update_thread_list target method for this |
3948 | target. */ | |
3949 | ||
f6ac5f3d PA |
3950 | void |
3951 | linux_nat_target::update_thread_list () | |
8a06aea7 | 3952 | { |
4a6ed09b PA |
3953 | /* We add/delete threads from the list as clone/exit events are |
3954 | processed, so just try deleting exited threads still in the | |
3955 | thread list. */ | |
3956 | delete_exited_threads (); | |
a6904d5a PA |
3957 | |
3958 | /* Update the processor core that each lwp/thread was last seen | |
3959 | running on. */ | |
901b9821 | 3960 | for (lwp_info *lwp : all_lwps ()) |
1ad3de98 PA |
3961 | { |
3962 | /* Avoid accessing /proc if the thread hasn't run since we last | |
3963 | time we fetched the thread's core. Accessing /proc becomes | |
3964 | noticeably expensive when we have thousands of LWPs. */ | |
3965 | if (lwp->core == -1) | |
3966 | lwp->core = linux_common_core_of_thread (lwp->ptid); | |
3967 | } | |
8a06aea7 PA |
3968 | } |
3969 | ||
a068643d | 3970 | std::string |
f6ac5f3d | 3971 | linux_nat_target::pid_to_str (ptid_t ptid) |
d6b0e80f | 3972 | { |
15a9e13e | 3973 | if (ptid.lwp_p () |
e38504b3 | 3974 | && (ptid.pid () != ptid.lwp () |
e99b03dc | 3975 | || num_lwps (ptid.pid ()) > 1)) |
a068643d | 3976 | return string_printf ("LWP %ld", ptid.lwp ()); |
d6b0e80f AC |
3977 | |
3978 | return normal_pid_to_str (ptid); | |
3979 | } | |
3980 | ||
f6ac5f3d PA |
3981 | const char * |
3982 | linux_nat_target::thread_name (struct thread_info *thr) | |
4694da01 | 3983 | { |
79efa585 | 3984 | return linux_proc_tid_get_name (thr->ptid); |
4694da01 TT |
3985 | } |
3986 | ||
dba24537 AC |
3987 | /* Accepts an integer PID; Returns a string representing a file that |
3988 | can be opened to get the symbols for the child process. */ | |
3989 | ||
0e90c441 | 3990 | const char * |
f6ac5f3d | 3991 | linux_nat_target::pid_to_exec_file (int pid) |
dba24537 | 3992 | { |
e0d86d2c | 3993 | return linux_proc_pid_to_exec_file (pid); |
dba24537 AC |
3994 | } |
3995 | ||
8a89ddbd PA |
3996 | /* Object representing an /proc/PID/mem open file. We keep one such |
3997 | file open per inferior. | |
3998 | ||
3999 | It might be tempting to think about only ever opening one file at | |
4000 | most for all inferiors, closing/reopening the file as we access | |
4001 | memory of different inferiors, to minimize number of file | |
4002 | descriptors open, which can otherwise run into resource limits. | |
4003 | However, that does not work correctly -- if the inferior execs and | |
4004 | we haven't processed the exec event yet, and, we opened a | |
4005 | /proc/PID/mem file, we will get a mem file accessing the post-exec | |
4006 | address space, thinking we're opening it for the pre-exec address | |
4007 | space. That is dangerous as we can poke memory (e.g. clearing | |
4008 | breakpoints) in the post-exec memory by mistake, corrupting the | |
4009 | inferior. For that reason, we open the mem file as early as | |
4010 | possible, right after spawning, forking or attaching to the | |
4011 | inferior, when the inferior is stopped and thus before it has a | |
4012 | chance of execing. | |
4013 | ||
4014 | Note that after opening the file, even if the thread we opened it | |
4015 | for subsequently exits, the open file is still usable for accessing | |
4016 | memory. It's only when the whole process exits or execs that the | |
4017 | file becomes invalid, at which point reads/writes return EOF. */ | |
4018 | ||
4019 | class proc_mem_file | |
4020 | { | |
4021 | public: | |
4022 | proc_mem_file (ptid_t ptid, int fd) | |
4023 | : m_ptid (ptid), m_fd (fd) | |
4024 | { | |
4025 | gdb_assert (m_fd != -1); | |
4026 | } | |
05c06f31 | 4027 | |
8a89ddbd | 4028 | ~proc_mem_file () |
05c06f31 | 4029 | { |
89662f69 | 4030 | linux_nat_debug_printf ("closing fd %d for /proc/%d/task/%ld/mem", |
8a89ddbd PA |
4031 | m_fd, m_ptid.pid (), m_ptid.lwp ()); |
4032 | close (m_fd); | |
05c06f31 | 4033 | } |
05c06f31 | 4034 | |
8a89ddbd PA |
4035 | DISABLE_COPY_AND_ASSIGN (proc_mem_file); |
4036 | ||
4037 | int fd () | |
4038 | { | |
4039 | return m_fd; | |
4040 | } | |
4041 | ||
4042 | private: | |
4043 | /* The LWP this file was opened for. Just for debugging | |
4044 | purposes. */ | |
4045 | ptid_t m_ptid; | |
4046 | ||
4047 | /* The file descriptor. */ | |
4048 | int m_fd = -1; | |
4049 | }; | |
4050 | ||
4051 | /* The map between an inferior process id, and the open /proc/PID/mem | |
4052 | file. This is stored in a map instead of in a per-inferior | |
4053 | structure because we need to be able to access memory of processes | |
4054 | which don't have a corresponding struct inferior object. E.g., | |
4055 | with "detach-on-fork on" (the default), and "follow-fork parent" | |
4056 | (also default), we don't create an inferior for the fork child, but | |
4057 | we still need to remove breakpoints from the fork child's | |
4058 | memory. */ | |
4059 | static std::unordered_map<int, proc_mem_file> proc_mem_file_map; | |
4060 | ||
4061 | /* Close the /proc/PID/mem file for PID. */ | |
05c06f31 PA |
4062 | |
4063 | static void | |
8a89ddbd | 4064 | close_proc_mem_file (pid_t pid) |
dba24537 | 4065 | { |
8a89ddbd | 4066 | proc_mem_file_map.erase (pid); |
05c06f31 | 4067 | } |
dba24537 | 4068 | |
8a89ddbd PA |
4069 | /* Open the /proc/PID/mem file for the process (thread group) of PTID. |
4070 | We actually open /proc/PID/task/LWP/mem, as that's the LWP we know | |
4071 | exists and is stopped right now. We prefer the | |
4072 | /proc/PID/task/LWP/mem form over /proc/LWP/mem to avoid tid-reuse | |
4073 | races, just in case this is ever called on an already-waited | |
4074 | LWP. */ | |
dba24537 | 4075 | |
8a89ddbd PA |
4076 | static void |
4077 | open_proc_mem_file (ptid_t ptid) | |
05c06f31 | 4078 | { |
8a89ddbd PA |
4079 | auto iter = proc_mem_file_map.find (ptid.pid ()); |
4080 | gdb_assert (iter == proc_mem_file_map.end ()); | |
dba24537 | 4081 | |
8a89ddbd PA |
4082 | char filename[64]; |
4083 | xsnprintf (filename, sizeof filename, | |
4084 | "/proc/%d/task/%ld/mem", ptid.pid (), ptid.lwp ()); | |
4085 | ||
4086 | int fd = gdb_open_cloexec (filename, O_RDWR | O_LARGEFILE, 0).release (); | |
05c06f31 | 4087 | |
8a89ddbd PA |
4088 | if (fd == -1) |
4089 | { | |
4090 | warning (_("opening /proc/PID/mem file for lwp %d.%ld failed: %s (%d)"), | |
4091 | ptid.pid (), ptid.lwp (), | |
4092 | safe_strerror (errno), errno); | |
4093 | return; | |
05c06f31 PA |
4094 | } |
4095 | ||
8a89ddbd PA |
4096 | proc_mem_file_map.emplace (std::piecewise_construct, |
4097 | std::forward_as_tuple (ptid.pid ()), | |
4098 | std::forward_as_tuple (ptid, fd)); | |
4099 | ||
9221923c | 4100 | linux_nat_debug_printf ("opened fd %d for lwp %d.%ld", |
8a89ddbd PA |
4101 | fd, ptid.pid (), ptid.lwp ()); |
4102 | } | |
4103 | ||
1bcb0708 PA |
4104 | /* Helper for linux_proc_xfer_memory_partial and |
4105 | proc_mem_file_is_writable. FD is the already opened /proc/pid/mem | |
4106 | file, and PID is the pid of the corresponding process. The rest of | |
4107 | the arguments are like linux_proc_xfer_memory_partial's. */ | |
8a89ddbd PA |
4108 | |
4109 | static enum target_xfer_status | |
1bcb0708 PA |
4110 | linux_proc_xfer_memory_partial_fd (int fd, int pid, |
4111 | gdb_byte *readbuf, const gdb_byte *writebuf, | |
4112 | ULONGEST offset, LONGEST len, | |
4113 | ULONGEST *xfered_len) | |
8a89ddbd PA |
4114 | { |
4115 | ssize_t ret; | |
4116 | ||
8a89ddbd | 4117 | gdb_assert (fd != -1); |
dba24537 | 4118 | |
31a56a22 PA |
4119 | /* Use pread64/pwrite64 if available, since they save a syscall and |
4120 | can handle 64-bit offsets even on 32-bit platforms (for instance, | |
4121 | SPARC debugging a SPARC64 application). But only use them if the | |
4122 | offset isn't so high that when cast to off_t it'd be negative, as | |
4123 | seen on SPARC64. pread64/pwrite64 outright reject such offsets. | |
4124 | lseek does not. */ | |
dba24537 | 4125 | #ifdef HAVE_PREAD64 |
31a56a22 PA |
4126 | if ((off_t) offset >= 0) |
4127 | ret = (readbuf != nullptr | |
4128 | ? pread64 (fd, readbuf, len, offset) | |
4129 | : pwrite64 (fd, writebuf, len, offset)); | |
4130 | else | |
dba24537 | 4131 | #endif |
31a56a22 PA |
4132 | { |
4133 | ret = lseek (fd, offset, SEEK_SET); | |
4134 | if (ret != -1) | |
4135 | ret = (readbuf != nullptr | |
4136 | ? read (fd, readbuf, len) | |
4137 | : write (fd, writebuf, len)); | |
4138 | } | |
dba24537 | 4139 | |
05c06f31 PA |
4140 | if (ret == -1) |
4141 | { | |
9221923c | 4142 | linux_nat_debug_printf ("accessing fd %d for pid %d failed: %s (%d)", |
1bcb0708 | 4143 | fd, pid, safe_strerror (errno), errno); |
284b6bb5 | 4144 | return TARGET_XFER_E_IO; |
05c06f31 PA |
4145 | } |
4146 | else if (ret == 0) | |
4147 | { | |
8a89ddbd PA |
4148 | /* EOF means the address space is gone, the whole process exited |
4149 | or execed. */ | |
9221923c | 4150 | linux_nat_debug_printf ("accessing fd %d for pid %d got EOF", |
1bcb0708 | 4151 | fd, pid); |
05c06f31 PA |
4152 | return TARGET_XFER_EOF; |
4153 | } | |
9b409511 YQ |
4154 | else |
4155 | { | |
8a89ddbd | 4156 | *xfered_len = ret; |
9b409511 YQ |
4157 | return TARGET_XFER_OK; |
4158 | } | |
05c06f31 | 4159 | } |
efcbbd14 | 4160 | |
1bcb0708 PA |
4161 | /* Implement the to_xfer_partial target method using /proc/PID/mem. |
4162 | Because we can use a single read/write call, this can be much more | |
4163 | efficient than banging away at PTRACE_PEEKTEXT. Also, unlike | |
4164 | PTRACE_PEEKTEXT/PTRACE_POKETEXT, this works with running | |
4165 | threads. */ | |
4166 | ||
4167 | static enum target_xfer_status | |
f9f593dd SM |
4168 | linux_proc_xfer_memory_partial (int pid, gdb_byte *readbuf, |
4169 | const gdb_byte *writebuf, ULONGEST offset, | |
4170 | LONGEST len, ULONGEST *xfered_len) | |
1bcb0708 | 4171 | { |
1bcb0708 PA |
4172 | auto iter = proc_mem_file_map.find (pid); |
4173 | if (iter == proc_mem_file_map.end ()) | |
4174 | return TARGET_XFER_EOF; | |
4175 | ||
4176 | int fd = iter->second.fd (); | |
4177 | ||
4178 | return linux_proc_xfer_memory_partial_fd (fd, pid, readbuf, writebuf, offset, | |
4179 | len, xfered_len); | |
4180 | } | |
4181 | ||
4182 | /* Check whether /proc/pid/mem is writable in the current kernel, and | |
4183 | return true if so. It wasn't writable before Linux 2.6.39, but | |
4184 | there's no way to know whether the feature was backported to older | |
4185 | kernels. So we check to see if it works. The result is cached, | |
3bfdcabb | 4186 | and this is guaranteed to be called once early during inferior |
9dff6a5d PA |
4187 | startup, so that any warning is printed out consistently between |
4188 | GDB invocations. Note we don't call it during GDB startup instead | |
4189 | though, because then we might warn with e.g. just "gdb --version" | |
4190 | on sandboxed systems. See PR gdb/29907. */ | |
1bcb0708 PA |
4191 | |
4192 | static bool | |
4193 | proc_mem_file_is_writable () | |
4194 | { | |
6b09f134 | 4195 | static std::optional<bool> writable; |
1bcb0708 PA |
4196 | |
4197 | if (writable.has_value ()) | |
4198 | return *writable; | |
4199 | ||
4200 | writable.emplace (false); | |
4201 | ||
4202 | /* We check whether /proc/pid/mem is writable by trying to write to | |
4203 | one of our variables via /proc/self/mem. */ | |
4204 | ||
4205 | int fd = gdb_open_cloexec ("/proc/self/mem", O_RDWR | O_LARGEFILE, 0).release (); | |
4206 | ||
4207 | if (fd == -1) | |
4208 | { | |
4209 | warning (_("opening /proc/self/mem file failed: %s (%d)"), | |
4210 | safe_strerror (errno), errno); | |
4211 | return *writable; | |
4212 | } | |
4213 | ||
4214 | SCOPE_EXIT { close (fd); }; | |
4215 | ||
4216 | /* This is the variable we try to write to. Note OFFSET below. */ | |
4217 | volatile gdb_byte test_var = 0; | |
4218 | ||
4219 | gdb_byte writebuf[] = {0x55}; | |
4220 | ULONGEST offset = (uintptr_t) &test_var; | |
4221 | ULONGEST xfered_len; | |
4222 | ||
4223 | enum target_xfer_status res | |
4224 | = linux_proc_xfer_memory_partial_fd (fd, getpid (), nullptr, writebuf, | |
4225 | offset, 1, &xfered_len); | |
4226 | ||
4227 | if (res == TARGET_XFER_OK) | |
4228 | { | |
4229 | gdb_assert (xfered_len == 1); | |
4230 | gdb_assert (test_var == 0x55); | |
4231 | /* Success. */ | |
4232 | *writable = true; | |
4233 | } | |
4234 | ||
4235 | return *writable; | |
4236 | } | |
4237 | ||
dba24537 AC |
4238 | /* Parse LINE as a signal set and add its set bits to SIGS. */ |
4239 | ||
4240 | static void | |
4241 | add_line_to_sigset (const char *line, sigset_t *sigs) | |
4242 | { | |
4243 | int len = strlen (line) - 1; | |
4244 | const char *p; | |
4245 | int signum; | |
4246 | ||
4247 | if (line[len] != '\n') | |
8a3fe4f8 | 4248 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4249 | |
4250 | p = line; | |
4251 | signum = len * 4; | |
4252 | while (len-- > 0) | |
4253 | { | |
4254 | int digit; | |
4255 | ||
4256 | if (*p >= '0' && *p <= '9') | |
4257 | digit = *p - '0'; | |
4258 | else if (*p >= 'a' && *p <= 'f') | |
4259 | digit = *p - 'a' + 10; | |
4260 | else | |
8a3fe4f8 | 4261 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4262 | |
4263 | signum -= 4; | |
4264 | ||
4265 | if (digit & 1) | |
4266 | sigaddset (sigs, signum + 1); | |
4267 | if (digit & 2) | |
4268 | sigaddset (sigs, signum + 2); | |
4269 | if (digit & 4) | |
4270 | sigaddset (sigs, signum + 3); | |
4271 | if (digit & 8) | |
4272 | sigaddset (sigs, signum + 4); | |
4273 | ||
4274 | p++; | |
4275 | } | |
4276 | } | |
4277 | ||
4278 | /* Find process PID's pending signals from /proc/pid/status and set | |
4279 | SIGS to match. */ | |
4280 | ||
4281 | void | |
3e43a32a MS |
4282 | linux_proc_pending_signals (int pid, sigset_t *pending, |
4283 | sigset_t *blocked, sigset_t *ignored) | |
dba24537 | 4284 | { |
d8d2a3ee | 4285 | char buffer[PATH_MAX], fname[PATH_MAX]; |
dba24537 AC |
4286 | |
4287 | sigemptyset (pending); | |
4288 | sigemptyset (blocked); | |
4289 | sigemptyset (ignored); | |
cde33bf1 | 4290 | xsnprintf (fname, sizeof fname, "/proc/%d/status", pid); |
d419f42d | 4291 | gdb_file_up procfile = gdb_fopen_cloexec (fname, "r"); |
dba24537 | 4292 | if (procfile == NULL) |
8a3fe4f8 | 4293 | error (_("Could not open %s"), fname); |
dba24537 | 4294 | |
d419f42d | 4295 | while (fgets (buffer, PATH_MAX, procfile.get ()) != NULL) |
dba24537 AC |
4296 | { |
4297 | /* Normal queued signals are on the SigPnd line in the status | |
4298 | file. However, 2.6 kernels also have a "shared" pending | |
4299 | queue for delivering signals to a thread group, so check for | |
4300 | a ShdPnd line also. | |
4301 | ||
4302 | Unfortunately some Red Hat kernels include the shared pending | |
4303 | queue but not the ShdPnd status field. */ | |
4304 | ||
61012eef | 4305 | if (startswith (buffer, "SigPnd:\t")) |
dba24537 | 4306 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4307 | else if (startswith (buffer, "ShdPnd:\t")) |
dba24537 | 4308 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4309 | else if (startswith (buffer, "SigBlk:\t")) |
dba24537 | 4310 | add_line_to_sigset (buffer + 8, blocked); |
61012eef | 4311 | else if (startswith (buffer, "SigIgn:\t")) |
dba24537 AC |
4312 | add_line_to_sigset (buffer + 8, ignored); |
4313 | } | |
dba24537 AC |
4314 | } |
4315 | ||
9b409511 | 4316 | static enum target_xfer_status |
f6ac5f3d | 4317 | linux_nat_xfer_osdata (enum target_object object, |
e0881a8e | 4318 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
4319 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
4320 | ULONGEST *xfered_len) | |
07e059b5 | 4321 | { |
07e059b5 VP |
4322 | gdb_assert (object == TARGET_OBJECT_OSDATA); |
4323 | ||
9b409511 YQ |
4324 | *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len); |
4325 | if (*xfered_len == 0) | |
4326 | return TARGET_XFER_EOF; | |
4327 | else | |
4328 | return TARGET_XFER_OK; | |
07e059b5 VP |
4329 | } |
4330 | ||
f6ac5f3d PA |
4331 | std::vector<static_tracepoint_marker> |
4332 | linux_nat_target::static_tracepoint_markers_by_strid (const char *strid) | |
5808517f YQ |
4333 | { |
4334 | char s[IPA_CMD_BUF_SIZE]; | |
e99b03dc | 4335 | int pid = inferior_ptid.pid (); |
5d9310c4 | 4336 | std::vector<static_tracepoint_marker> markers; |
256642e8 | 4337 | const char *p = s; |
184ea2f7 | 4338 | ptid_t ptid = ptid_t (pid, 0); |
5d9310c4 | 4339 | static_tracepoint_marker marker; |
5808517f YQ |
4340 | |
4341 | /* Pause all */ | |
4342 | target_stop (ptid); | |
4343 | ||
81aa19c3 | 4344 | strcpy (s, "qTfSTM"); |
42476b70 | 4345 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f | 4346 | |
1db93f14 TT |
4347 | /* Unpause all. */ |
4348 | SCOPE_EXIT { target_continue_no_signal (ptid); }; | |
5808517f YQ |
4349 | |
4350 | while (*p++ == 'm') | |
4351 | { | |
5808517f YQ |
4352 | do |
4353 | { | |
5d9310c4 | 4354 | parse_static_tracepoint_marker_definition (p, &p, &marker); |
5808517f | 4355 | |
5d9310c4 SM |
4356 | if (strid == NULL || marker.str_id == strid) |
4357 | markers.push_back (std::move (marker)); | |
5808517f YQ |
4358 | } |
4359 | while (*p++ == ','); /* comma-separated list */ | |
4360 | ||
81aa19c3 | 4361 | strcpy (s, "qTsSTM"); |
42476b70 | 4362 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4363 | p = s; |
4364 | } | |
4365 | ||
5808517f YQ |
4366 | return markers; |
4367 | } | |
4368 | ||
b84876c2 PA |
4369 | /* target_can_async_p implementation. */ |
4370 | ||
57810aa7 | 4371 | bool |
f6ac5f3d | 4372 | linux_nat_target::can_async_p () |
b84876c2 | 4373 | { |
fce6cd34 AB |
4374 | /* This flag should be checked in the common target.c code. */ |
4375 | gdb_assert (target_async_permitted); | |
4376 | ||
4377 | /* Otherwise, this targets is always able to support async mode. */ | |
4378 | return true; | |
b84876c2 PA |
4379 | } |
4380 | ||
57810aa7 | 4381 | bool |
f6ac5f3d | 4382 | linux_nat_target::supports_non_stop () |
9908b566 | 4383 | { |
f80c8ec4 | 4384 | return true; |
9908b566 VP |
4385 | } |
4386 | ||
fbea99ea PA |
4387 | /* to_always_non_stop_p implementation. */ |
4388 | ||
57810aa7 | 4389 | bool |
f6ac5f3d | 4390 | linux_nat_target::always_non_stop_p () |
fbea99ea | 4391 | { |
f80c8ec4 | 4392 | return true; |
fbea99ea PA |
4393 | } |
4394 | ||
57810aa7 | 4395 | bool |
f6ac5f3d | 4396 | linux_nat_target::supports_multi_process () |
d90e17a7 | 4397 | { |
aee91db3 | 4398 | return true; |
d90e17a7 PA |
4399 | } |
4400 | ||
57810aa7 | 4401 | bool |
f6ac5f3d | 4402 | linux_nat_target::supports_disable_randomization () |
03583c20 | 4403 | { |
f80c8ec4 | 4404 | return true; |
03583c20 UW |
4405 | } |
4406 | ||
7feb7d06 PA |
4407 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
4408 | so we notice when any child changes state, and notify the | |
4409 | event-loop; it allows us to use sigsuspend in linux_nat_wait_1 | |
4410 | above to wait for the arrival of a SIGCHLD. */ | |
4411 | ||
b84876c2 | 4412 | static void |
7feb7d06 | 4413 | sigchld_handler (int signo) |
b84876c2 | 4414 | { |
7feb7d06 PA |
4415 | int old_errno = errno; |
4416 | ||
01124a23 | 4417 | if (debug_linux_nat) |
da5bd37e | 4418 | gdb_stdlog->write_async_safe ("sigchld\n", sizeof ("sigchld\n") - 1); |
7feb7d06 | 4419 | |
b146ba14 JB |
4420 | if (signo == SIGCHLD) |
4421 | { | |
4422 | /* Let the event loop know that there are events to handle. */ | |
4423 | linux_nat_target::async_file_mark_if_open (); | |
4424 | } | |
7feb7d06 PA |
4425 | |
4426 | errno = old_errno; | |
4427 | } | |
4428 | ||
4429 | /* Callback registered with the target events file descriptor. */ | |
4430 | ||
4431 | static void | |
4432 | handle_target_event (int error, gdb_client_data client_data) | |
4433 | { | |
b1a35af2 | 4434 | inferior_event_handler (INF_REG_EVENT); |
7feb7d06 PA |
4435 | } |
4436 | ||
b84876c2 PA |
4437 | /* target_async implementation. */ |
4438 | ||
f6ac5f3d | 4439 | void |
4a570176 | 4440 | linux_nat_target::async (bool enable) |
b84876c2 | 4441 | { |
4a570176 | 4442 | if (enable == is_async_p ()) |
b146ba14 JB |
4443 | return; |
4444 | ||
4445 | /* Block child signals while we create/destroy the pipe, as their | |
4446 | handler writes to it. */ | |
4447 | gdb::block_signals blocker; | |
4448 | ||
6a3753b3 | 4449 | if (enable) |
b84876c2 | 4450 | { |
b146ba14 | 4451 | if (!async_file_open ()) |
f34652de | 4452 | internal_error ("creating event pipe failed."); |
b146ba14 JB |
4453 | |
4454 | add_file_handler (async_wait_fd (), handle_target_event, NULL, | |
4455 | "linux-nat"); | |
4456 | ||
4457 | /* There may be pending events to handle. Tell the event loop | |
4458 | to poll them. */ | |
4459 | async_file_mark (); | |
b84876c2 PA |
4460 | } |
4461 | else | |
4462 | { | |
b146ba14 JB |
4463 | delete_file_handler (async_wait_fd ()); |
4464 | async_file_close (); | |
b84876c2 | 4465 | } |
b84876c2 PA |
4466 | } |
4467 | ||
a493e3e2 | 4468 | /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other |
252fbfc8 PA |
4469 | event came out. */ |
4470 | ||
4c28f408 | 4471 | static int |
d3a70e03 | 4472 | linux_nat_stop_lwp (struct lwp_info *lwp) |
4c28f408 | 4473 | { |
d90e17a7 | 4474 | if (!lwp->stopped) |
252fbfc8 | 4475 | { |
9327494e | 4476 | linux_nat_debug_printf ("running -> suspending %s", |
e53c95d4 | 4477 | lwp->ptid.to_string ().c_str ()); |
252fbfc8 | 4478 | |
252fbfc8 | 4479 | |
25289eb2 PA |
4480 | if (lwp->last_resume_kind == resume_stop) |
4481 | { | |
9327494e SM |
4482 | linux_nat_debug_printf ("already stopping LWP %ld at GDB's request", |
4483 | lwp->ptid.lwp ()); | |
25289eb2 PA |
4484 | return 0; |
4485 | } | |
252fbfc8 | 4486 | |
d3a70e03 | 4487 | stop_callback (lwp); |
25289eb2 | 4488 | lwp->last_resume_kind = resume_stop; |
d90e17a7 PA |
4489 | } |
4490 | else | |
4491 | { | |
4492 | /* Already known to be stopped; do nothing. */ | |
252fbfc8 | 4493 | |
d90e17a7 PA |
4494 | if (debug_linux_nat) |
4495 | { | |
9213a6d7 | 4496 | if (linux_target->find_thread (lwp->ptid)->stop_requested) |
9327494e | 4497 | linux_nat_debug_printf ("already stopped/stop_requested %s", |
e53c95d4 | 4498 | lwp->ptid.to_string ().c_str ()); |
d90e17a7 | 4499 | else |
9327494e | 4500 | linux_nat_debug_printf ("already stopped/no stop_requested yet %s", |
e53c95d4 | 4501 | lwp->ptid.to_string ().c_str ()); |
252fbfc8 PA |
4502 | } |
4503 | } | |
4c28f408 PA |
4504 | return 0; |
4505 | } | |
4506 | ||
f6ac5f3d PA |
4507 | void |
4508 | linux_nat_target::stop (ptid_t ptid) | |
4c28f408 | 4509 | { |
b6e52a0b | 4510 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
d3a70e03 | 4511 | iterate_over_lwps (ptid, linux_nat_stop_lwp); |
bfedc46a PA |
4512 | } |
4513 | ||
dc146f7c VP |
4514 | /* Return the cached value of the processor core for thread PTID. */ |
4515 | ||
f6ac5f3d PA |
4516 | int |
4517 | linux_nat_target::core_of_thread (ptid_t ptid) | |
dc146f7c VP |
4518 | { |
4519 | struct lwp_info *info = find_lwp_pid (ptid); | |
e0881a8e | 4520 | |
dc146f7c VP |
4521 | if (info) |
4522 | return info->core; | |
4523 | return -1; | |
4524 | } | |
4525 | ||
7a6a1731 GB |
4526 | /* Implementation of to_filesystem_is_local. */ |
4527 | ||
57810aa7 | 4528 | bool |
f6ac5f3d | 4529 | linux_nat_target::filesystem_is_local () |
7a6a1731 GB |
4530 | { |
4531 | struct inferior *inf = current_inferior (); | |
4532 | ||
4533 | if (inf->fake_pid_p || inf->pid == 0) | |
57810aa7 | 4534 | return true; |
7a6a1731 GB |
4535 | |
4536 | return linux_ns_same (inf->pid, LINUX_NS_MNT); | |
4537 | } | |
4538 | ||
4539 | /* Convert the INF argument passed to a to_fileio_* method | |
4540 | to a process ID suitable for passing to its corresponding | |
4541 | linux_mntns_* function. If INF is non-NULL then the | |
4542 | caller is requesting the filesystem seen by INF. If INF | |
4543 | is NULL then the caller is requesting the filesystem seen | |
4544 | by the GDB. We fall back to GDB's filesystem in the case | |
4545 | that INF is non-NULL but its PID is unknown. */ | |
4546 | ||
4547 | static pid_t | |
4548 | linux_nat_fileio_pid_of (struct inferior *inf) | |
4549 | { | |
4550 | if (inf == NULL || inf->fake_pid_p || inf->pid == 0) | |
4551 | return getpid (); | |
4552 | else | |
4553 | return inf->pid; | |
4554 | } | |
4555 | ||
4556 | /* Implementation of to_fileio_open. */ | |
4557 | ||
f6ac5f3d PA |
4558 | int |
4559 | linux_nat_target::fileio_open (struct inferior *inf, const char *filename, | |
4560 | int flags, int mode, int warn_if_slow, | |
b872057a | 4561 | fileio_error *target_errno) |
7a6a1731 GB |
4562 | { |
4563 | int nat_flags; | |
4564 | mode_t nat_mode; | |
4565 | int fd; | |
4566 | ||
4567 | if (fileio_to_host_openflags (flags, &nat_flags) == -1 | |
4568 | || fileio_to_host_mode (mode, &nat_mode) == -1) | |
4569 | { | |
4570 | *target_errno = FILEIO_EINVAL; | |
4571 | return -1; | |
4572 | } | |
4573 | ||
4574 | fd = linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf), | |
4575 | filename, nat_flags, nat_mode); | |
4576 | if (fd == -1) | |
4577 | *target_errno = host_to_fileio_error (errno); | |
4578 | ||
4579 | return fd; | |
4580 | } | |
4581 | ||
4582 | /* Implementation of to_fileio_readlink. */ | |
4583 | ||
6b09f134 | 4584 | std::optional<std::string> |
f6ac5f3d | 4585 | linux_nat_target::fileio_readlink (struct inferior *inf, const char *filename, |
b872057a | 4586 | fileio_error *target_errno) |
7a6a1731 GB |
4587 | { |
4588 | char buf[PATH_MAX]; | |
4589 | int len; | |
7a6a1731 GB |
4590 | |
4591 | len = linux_mntns_readlink (linux_nat_fileio_pid_of (inf), | |
4592 | filename, buf, sizeof (buf)); | |
4593 | if (len < 0) | |
4594 | { | |
4595 | *target_errno = host_to_fileio_error (errno); | |
e0d3522b | 4596 | return {}; |
7a6a1731 GB |
4597 | } |
4598 | ||
e0d3522b | 4599 | return std::string (buf, len); |
7a6a1731 GB |
4600 | } |
4601 | ||
4602 | /* Implementation of to_fileio_unlink. */ | |
4603 | ||
f6ac5f3d PA |
4604 | int |
4605 | linux_nat_target::fileio_unlink (struct inferior *inf, const char *filename, | |
b872057a | 4606 | fileio_error *target_errno) |
7a6a1731 GB |
4607 | { |
4608 | int ret; | |
4609 | ||
4610 | ret = linux_mntns_unlink (linux_nat_fileio_pid_of (inf), | |
4611 | filename); | |
4612 | if (ret == -1) | |
4613 | *target_errno = host_to_fileio_error (errno); | |
4614 | ||
4615 | return ret; | |
4616 | } | |
4617 | ||
aa01bd36 PA |
4618 | /* Implementation of the to_thread_events method. */ |
4619 | ||
f6ac5f3d PA |
4620 | void |
4621 | linux_nat_target::thread_events (int enable) | |
aa01bd36 PA |
4622 | { |
4623 | report_thread_events = enable; | |
4624 | } | |
4625 | ||
25b16bc9 PA |
4626 | bool |
4627 | linux_nat_target::supports_set_thread_options (gdb_thread_options options) | |
4628 | { | |
a51e14ef PA |
4629 | constexpr gdb_thread_options supported_options |
4630 | = GDB_THREAD_OPTION_CLONE | GDB_THREAD_OPTION_EXIT; | |
25b16bc9 PA |
4631 | return ((options & supported_options) == options); |
4632 | } | |
4633 | ||
f6ac5f3d PA |
4634 | linux_nat_target::linux_nat_target () |
4635 | { | |
f973ed9c DJ |
4636 | /* We don't change the stratum; this target will sit at |
4637 | process_stratum and thread_db will set at thread_stratum. This | |
4638 | is a little strange, since this is a multi-threaded-capable | |
4639 | target, but we want to be on the stack below thread_db, and we | |
4640 | also want to be used for single-threaded processes. */ | |
f973ed9c DJ |
4641 | } |
4642 | ||
f865ee35 JK |
4643 | /* See linux-nat.h. */ |
4644 | ||
ef632b4b | 4645 | bool |
f865ee35 | 4646 | linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo) |
9f0bdab8 | 4647 | { |
0acd1110 | 4648 | int pid = get_ptrace_pid (ptid); |
7cc662bc | 4649 | return ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo) == 0; |
9f0bdab8 DJ |
4650 | } |
4651 | ||
7b669087 GB |
4652 | /* See nat/linux-nat.h. */ |
4653 | ||
4654 | ptid_t | |
4655 | current_lwp_ptid (void) | |
4656 | { | |
15a9e13e | 4657 | gdb_assert (inferior_ptid.lwp_p ()); |
7b669087 GB |
4658 | return inferior_ptid; |
4659 | } | |
4660 | ||
0ae5b8fa AB |
4661 | /* Implement 'maintenance info linux-lwps'. Displays some basic |
4662 | information about all the current lwp_info objects. */ | |
4663 | ||
4664 | static void | |
4665 | maintenance_info_lwps (const char *arg, int from_tty) | |
4666 | { | |
4667 | if (all_lwps ().size () == 0) | |
4668 | { | |
4669 | gdb_printf ("No Linux LWPs\n"); | |
4670 | return; | |
4671 | } | |
4672 | ||
4673 | /* Start the width at 8 to match the column heading below, then | |
4674 | figure out the widest ptid string. We'll use this to build our | |
4675 | output table below. */ | |
4676 | size_t ptid_width = 8; | |
4677 | for (lwp_info *lp : all_lwps ()) | |
4678 | ptid_width = std::max (ptid_width, lp->ptid.to_string ().size ()); | |
4679 | ||
4680 | /* Setup the table headers. */ | |
4681 | struct ui_out *uiout = current_uiout; | |
4682 | ui_out_emit_table table_emitter (uiout, 2, -1, "linux-lwps"); | |
4683 | uiout->table_header (ptid_width, ui_left, "lwp-ptid", _("LWP Ptid")); | |
4684 | uiout->table_header (9, ui_left, "thread-info", _("Thread ID")); | |
4685 | uiout->table_body (); | |
4686 | ||
4687 | /* Display one table row for each lwp_info. */ | |
4688 | for (lwp_info *lp : all_lwps ()) | |
4689 | { | |
4690 | ui_out_emit_tuple tuple_emitter (uiout, "lwp-entry"); | |
4691 | ||
4692 | thread_info *th = linux_target->find_thread (lp->ptid); | |
4693 | ||
4694 | uiout->field_string ("lwp-ptid", lp->ptid.to_string ().c_str ()); | |
4695 | if (th == nullptr) | |
4696 | uiout->field_string ("thread-info", "None"); | |
4697 | else | |
4698 | uiout->field_string ("thread-info", print_full_thread_id (th)); | |
4699 | ||
4700 | uiout->message ("\n"); | |
4701 | } | |
4702 | } | |
4703 | ||
6c265988 | 4704 | void _initialize_linux_nat (); |
d6b0e80f | 4705 | void |
6c265988 | 4706 | _initialize_linux_nat () |
d6b0e80f | 4707 | { |
8864ef42 | 4708 | add_setshow_boolean_cmd ("linux-nat", class_maintenance, |
b6e52a0b | 4709 | &debug_linux_nat, _("\ |
6a2dbb74 EZ |
4710 | Set debugging of GNU/Linux native target."), _("\ |
4711 | Show debugging of GNU/Linux native target."), _("\ | |
b6e52a0b AB |
4712 | When on, print debug messages relating to the GNU/Linux native target."), |
4713 | nullptr, | |
4714 | show_debug_linux_nat, | |
4715 | &setdebuglist, &showdebuglist); | |
b84876c2 | 4716 | |
7a6a1731 GB |
4717 | add_setshow_boolean_cmd ("linux-namespaces", class_maintenance, |
4718 | &debug_linux_namespaces, _("\ | |
4719 | Set debugging of GNU/Linux namespaces module."), _("\ | |
4720 | Show debugging of GNU/Linux namespaces module."), _("\ | |
4721 | Enables printf debugging output."), | |
4722 | NULL, | |
4723 | NULL, | |
4724 | &setdebuglist, &showdebuglist); | |
4725 | ||
7feb7d06 PA |
4726 | /* Install a SIGCHLD handler. */ |
4727 | sigchld_action.sa_handler = sigchld_handler; | |
4728 | sigemptyset (&sigchld_action.sa_mask); | |
4729 | sigchld_action.sa_flags = SA_RESTART; | |
b84876c2 PA |
4730 | |
4731 | /* Make it the default. */ | |
7feb7d06 | 4732 | sigaction (SIGCHLD, &sigchld_action, NULL); |
d6b0e80f AC |
4733 | |
4734 | /* Make sure we don't block SIGCHLD during a sigsuspend. */ | |
21987b9c | 4735 | gdb_sigmask (SIG_SETMASK, NULL, &suspend_mask); |
d6b0e80f AC |
4736 | sigdelset (&suspend_mask, SIGCHLD); |
4737 | ||
7feb7d06 | 4738 | sigemptyset (&blocked_mask); |
774113b0 PA |
4739 | |
4740 | lwp_lwpid_htab_create (); | |
0ae5b8fa AB |
4741 | |
4742 | add_cmd ("linux-lwps", class_maintenance, maintenance_info_lwps, | |
4743 | _("List the Linux LWPS."), &maintenanceinfolist); | |
d6b0e80f AC |
4744 | } |
4745 | \f | |
4746 | ||
4747 | /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to | |
4748 | the GNU/Linux Threads library and therefore doesn't really belong | |
4749 | here. */ | |
4750 | ||
089436f7 TV |
4751 | /* NPTL reserves the first two RT signals, but does not provide any |
4752 | way for the debugger to query the signal numbers - fortunately | |
4753 | they don't change. */ | |
4754 | static int lin_thread_signals[] = { __SIGRTMIN, __SIGRTMIN + 1 }; | |
d6b0e80f | 4755 | |
089436f7 TV |
4756 | /* See linux-nat.h. */ |
4757 | ||
4758 | unsigned int | |
4759 | lin_thread_get_thread_signal_num (void) | |
d6b0e80f | 4760 | { |
089436f7 TV |
4761 | return sizeof (lin_thread_signals) / sizeof (lin_thread_signals[0]); |
4762 | } | |
d6b0e80f | 4763 | |
089436f7 TV |
4764 | /* See linux-nat.h. */ |
4765 | ||
4766 | int | |
4767 | lin_thread_get_thread_signal (unsigned int i) | |
4768 | { | |
4769 | gdb_assert (i < lin_thread_get_thread_signal_num ()); | |
4770 | return lin_thread_signals[i]; | |
d6b0e80f | 4771 | } |