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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 AC |
34 | #include "gdbthread.h" |
35 | #include "gdbcmd.h" | |
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 | ||
e7ad2f14 PA |
299 | static void save_stop_reason (struct lwp_info *lp); |
300 | ||
1bcb0708 | 301 | static bool proc_mem_file_is_writable (); |
8a89ddbd PA |
302 | static void close_proc_mem_file (pid_t pid); |
303 | static void open_proc_mem_file (ptid_t ptid); | |
05c06f31 | 304 | |
6cf20c46 PA |
305 | /* Return TRUE if LWP is the leader thread of the process. */ |
306 | ||
307 | static bool | |
308 | is_leader (lwp_info *lp) | |
309 | { | |
310 | return lp->ptid.pid () == lp->ptid.lwp (); | |
311 | } | |
312 | ||
57573e54 PA |
313 | /* Convert an LWP's pending status to a std::string. */ |
314 | ||
315 | static std::string | |
316 | pending_status_str (lwp_info *lp) | |
317 | { | |
318 | gdb_assert (lwp_status_pending_p (lp)); | |
319 | ||
320 | if (lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE) | |
321 | return lp->waitstatus.to_string (); | |
322 | else | |
323 | return status_to_str (lp->status); | |
324 | } | |
325 | ||
a51e14ef PA |
326 | /* Return true if we should report exit events for LP. */ |
327 | ||
328 | static bool | |
329 | report_exit_events_for (lwp_info *lp) | |
330 | { | |
331 | thread_info *thr = linux_target->find_thread (lp->ptid); | |
332 | gdb_assert (thr != nullptr); | |
333 | ||
334 | return (report_thread_events | |
335 | || (thr->thread_options () & GDB_THREAD_OPTION_EXIT) != 0); | |
336 | } | |
337 | ||
cff068da GB |
338 | \f |
339 | /* LWP accessors. */ | |
340 | ||
341 | /* See nat/linux-nat.h. */ | |
342 | ||
343 | ptid_t | |
344 | ptid_of_lwp (struct lwp_info *lwp) | |
345 | { | |
346 | return lwp->ptid; | |
347 | } | |
348 | ||
349 | /* See nat/linux-nat.h. */ | |
350 | ||
4b134ca1 GB |
351 | void |
352 | lwp_set_arch_private_info (struct lwp_info *lwp, | |
353 | struct arch_lwp_info *info) | |
354 | { | |
355 | lwp->arch_private = info; | |
356 | } | |
357 | ||
358 | /* See nat/linux-nat.h. */ | |
359 | ||
360 | struct arch_lwp_info * | |
361 | lwp_arch_private_info (struct lwp_info *lwp) | |
362 | { | |
363 | return lwp->arch_private; | |
364 | } | |
365 | ||
366 | /* See nat/linux-nat.h. */ | |
367 | ||
cff068da GB |
368 | int |
369 | lwp_is_stopped (struct lwp_info *lwp) | |
370 | { | |
371 | return lwp->stopped; | |
372 | } | |
373 | ||
374 | /* See nat/linux-nat.h. */ | |
375 | ||
376 | enum target_stop_reason | |
377 | lwp_stop_reason (struct lwp_info *lwp) | |
378 | { | |
379 | return lwp->stop_reason; | |
380 | } | |
381 | ||
0e00e962 AA |
382 | /* See nat/linux-nat.h. */ |
383 | ||
384 | int | |
385 | lwp_is_stepping (struct lwp_info *lwp) | |
386 | { | |
387 | return lwp->step; | |
388 | } | |
389 | ||
ae087d01 DJ |
390 | \f |
391 | /* Trivial list manipulation functions to keep track of a list of | |
392 | new stopped processes. */ | |
393 | static void | |
3d799a95 | 394 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
ae087d01 | 395 | { |
8d749320 | 396 | struct simple_pid_list *new_pid = XNEW (struct simple_pid_list); |
e0881a8e | 397 | |
ae087d01 | 398 | new_pid->pid = pid; |
3d799a95 | 399 | new_pid->status = status; |
ae087d01 DJ |
400 | new_pid->next = *listp; |
401 | *listp = new_pid; | |
402 | } | |
403 | ||
404 | static int | |
46a96992 | 405 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
ae087d01 DJ |
406 | { |
407 | struct simple_pid_list **p; | |
408 | ||
409 | for (p = listp; *p != NULL; p = &(*p)->next) | |
410 | if ((*p)->pid == pid) | |
411 | { | |
412 | struct simple_pid_list *next = (*p)->next; | |
e0881a8e | 413 | |
46a96992 | 414 | *statusp = (*p)->status; |
ae087d01 DJ |
415 | xfree (*p); |
416 | *p = next; | |
417 | return 1; | |
418 | } | |
419 | return 0; | |
420 | } | |
421 | ||
de0d863e DB |
422 | /* Return the ptrace options that we want to try to enable. */ |
423 | ||
424 | static int | |
425 | linux_nat_ptrace_options (int attached) | |
426 | { | |
427 | int options = 0; | |
428 | ||
429 | if (!attached) | |
430 | options |= PTRACE_O_EXITKILL; | |
431 | ||
432 | options |= (PTRACE_O_TRACESYSGOOD | |
433 | | PTRACE_O_TRACEVFORKDONE | |
434 | | PTRACE_O_TRACEVFORK | |
435 | | PTRACE_O_TRACEFORK | |
436 | | PTRACE_O_TRACEEXEC); | |
437 | ||
438 | return options; | |
439 | } | |
440 | ||
1b919490 VB |
441 | /* Initialize ptrace and procfs warnings and check for supported |
442 | ptrace features given PID. | |
beed38b8 JB |
443 | |
444 | ATTACHED should be nonzero iff we attached to the inferior. */ | |
3993f6b1 DJ |
445 | |
446 | static void | |
1b919490 | 447 | linux_init_ptrace_procfs (pid_t pid, int attached) |
3993f6b1 | 448 | { |
de0d863e DB |
449 | int options = linux_nat_ptrace_options (attached); |
450 | ||
451 | linux_enable_event_reporting (pid, options); | |
96d7229d | 452 | linux_ptrace_init_warnings (); |
1b919490 | 453 | linux_proc_init_warnings (); |
9dff6a5d | 454 | proc_mem_file_is_writable (); |
4de4c07c DJ |
455 | } |
456 | ||
f6ac5f3d PA |
457 | linux_nat_target::~linux_nat_target () |
458 | {} | |
459 | ||
460 | void | |
461 | linux_nat_target::post_attach (int pid) | |
4de4c07c | 462 | { |
1b919490 | 463 | linux_init_ptrace_procfs (pid, 1); |
4de4c07c DJ |
464 | } |
465 | ||
200fd287 AB |
466 | /* Implement the virtual inf_ptrace_target::post_startup_inferior method. */ |
467 | ||
f6ac5f3d PA |
468 | void |
469 | linux_nat_target::post_startup_inferior (ptid_t ptid) | |
4de4c07c | 470 | { |
1b919490 | 471 | linux_init_ptrace_procfs (ptid.pid (), 0); |
4de4c07c DJ |
472 | } |
473 | ||
4403d8e9 JK |
474 | /* Return the number of known LWPs in the tgid given by PID. */ |
475 | ||
476 | static int | |
477 | num_lwps (int pid) | |
478 | { | |
479 | int count = 0; | |
4403d8e9 | 480 | |
901b9821 | 481 | for (const lwp_info *lp ATTRIBUTE_UNUSED : all_lwps ()) |
e99b03dc | 482 | if (lp->ptid.pid () == pid) |
4403d8e9 JK |
483 | count++; |
484 | ||
485 | return count; | |
486 | } | |
487 | ||
169bb27b | 488 | /* Deleter for lwp_info unique_ptr specialisation. */ |
4403d8e9 | 489 | |
169bb27b | 490 | struct lwp_deleter |
4403d8e9 | 491 | { |
169bb27b AB |
492 | void operator() (struct lwp_info *lwp) const |
493 | { | |
494 | delete_lwp (lwp->ptid); | |
495 | } | |
496 | }; | |
4403d8e9 | 497 | |
169bb27b AB |
498 | /* A unique_ptr specialisation for lwp_info. */ |
499 | ||
500 | typedef std::unique_ptr<struct lwp_info, lwp_deleter> lwp_info_up; | |
4403d8e9 | 501 | |
82d1f134 | 502 | /* Target hook for follow_fork. */ |
d83ad864 | 503 | |
e97007b6 | 504 | void |
82d1f134 SM |
505 | linux_nat_target::follow_fork (inferior *child_inf, ptid_t child_ptid, |
506 | target_waitkind fork_kind, bool follow_child, | |
507 | bool detach_fork) | |
3993f6b1 | 508 | { |
82d1f134 SM |
509 | inf_ptrace_target::follow_fork (child_inf, child_ptid, fork_kind, |
510 | follow_child, detach_fork); | |
511 | ||
d83ad864 | 512 | if (!follow_child) |
4de4c07c | 513 | { |
3a849a34 SM |
514 | bool has_vforked = fork_kind == TARGET_WAITKIND_VFORKED; |
515 | ptid_t parent_ptid = inferior_ptid; | |
3a849a34 SM |
516 | int parent_pid = parent_ptid.lwp (); |
517 | int child_pid = child_ptid.lwp (); | |
4de4c07c | 518 | |
1777feb0 | 519 | /* We're already attached to the parent, by default. */ |
3a849a34 | 520 | lwp_info *child_lp = add_lwp (child_ptid); |
d83ad864 DB |
521 | child_lp->stopped = 1; |
522 | child_lp->last_resume_kind = resume_stop; | |
4de4c07c | 523 | |
ac264b3b MS |
524 | /* Detach new forked process? */ |
525 | if (detach_fork) | |
f75c00e4 | 526 | { |
95347337 AB |
527 | int child_stop_signal = 0; |
528 | bool detach_child = true; | |
4403d8e9 | 529 | |
169bb27b AB |
530 | /* Move CHILD_LP into a unique_ptr and clear the source pointer |
531 | to prevent us doing anything stupid with it. */ | |
532 | lwp_info_up child_lp_ptr (child_lp); | |
533 | child_lp = nullptr; | |
534 | ||
535 | linux_target->low_prepare_to_resume (child_lp_ptr.get ()); | |
c077881a HZ |
536 | |
537 | /* When debugging an inferior in an architecture that supports | |
538 | hardware single stepping on a kernel without commit | |
539 | 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child | |
540 | process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits | |
541 | set if the parent process had them set. | |
542 | To work around this, single step the child process | |
543 | once before detaching to clear the flags. */ | |
544 | ||
2fd9d7ca PA |
545 | /* Note that we consult the parent's architecture instead of |
546 | the child's because there's no inferior for the child at | |
547 | this point. */ | |
c077881a | 548 | if (!gdbarch_software_single_step_p (target_thread_architecture |
2fd9d7ca | 549 | (parent_ptid))) |
c077881a | 550 | { |
95347337 AB |
551 | int status; |
552 | ||
c077881a HZ |
553 | linux_disable_event_reporting (child_pid); |
554 | if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0) | |
555 | perror_with_name (_("Couldn't do single step")); | |
556 | if (my_waitpid (child_pid, &status, 0) < 0) | |
557 | perror_with_name (_("Couldn't wait vfork process")); | |
95347337 AB |
558 | else |
559 | { | |
560 | detach_child = WIFSTOPPED (status); | |
561 | child_stop_signal = WSTOPSIG (status); | |
562 | } | |
c077881a HZ |
563 | } |
564 | ||
95347337 | 565 | if (detach_child) |
9caaaa83 | 566 | { |
95347337 | 567 | int signo = child_stop_signal; |
9caaaa83 | 568 | |
9caaaa83 PA |
569 | if (signo != 0 |
570 | && !signal_pass_state (gdb_signal_from_host (signo))) | |
571 | signo = 0; | |
572 | ptrace (PTRACE_DETACH, child_pid, 0, signo); | |
8a89ddbd PA |
573 | |
574 | close_proc_mem_file (child_pid); | |
9caaaa83 | 575 | } |
ac264b3b | 576 | } |
9016a515 DJ |
577 | |
578 | if (has_vforked) | |
579 | { | |
a2885186 SM |
580 | lwp_info *parent_lp = find_lwp_pid (parent_ptid); |
581 | linux_nat_debug_printf ("waiting for VFORK_DONE on %d", parent_pid); | |
582 | parent_lp->stopped = 1; | |
6c95b8df | 583 | |
a2885186 SM |
584 | /* We'll handle the VFORK_DONE event like any other |
585 | event, in target_wait. */ | |
9016a515 | 586 | } |
4de4c07c | 587 | } |
3993f6b1 | 588 | else |
4de4c07c | 589 | { |
3ced3da4 | 590 | struct lwp_info *child_lp; |
4de4c07c | 591 | |
82d1f134 | 592 | child_lp = add_lwp (child_ptid); |
3ced3da4 | 593 | child_lp->stopped = 1; |
25289eb2 | 594 | child_lp->last_resume_kind = resume_stop; |
4de4c07c | 595 | } |
4de4c07c DJ |
596 | } |
597 | ||
4de4c07c | 598 | \f |
f6ac5f3d PA |
599 | int |
600 | linux_nat_target::insert_fork_catchpoint (int pid) | |
4de4c07c | 601 | { |
a2885186 | 602 | return 0; |
3993f6b1 DJ |
603 | } |
604 | ||
f6ac5f3d PA |
605 | int |
606 | linux_nat_target::remove_fork_catchpoint (int pid) | |
eb73ad13 PA |
607 | { |
608 | return 0; | |
609 | } | |
610 | ||
f6ac5f3d PA |
611 | int |
612 | linux_nat_target::insert_vfork_catchpoint (int pid) | |
3993f6b1 | 613 | { |
a2885186 | 614 | return 0; |
3993f6b1 DJ |
615 | } |
616 | ||
f6ac5f3d PA |
617 | int |
618 | linux_nat_target::remove_vfork_catchpoint (int pid) | |
eb73ad13 PA |
619 | { |
620 | return 0; | |
621 | } | |
622 | ||
f6ac5f3d PA |
623 | int |
624 | linux_nat_target::insert_exec_catchpoint (int pid) | |
3993f6b1 | 625 | { |
a2885186 | 626 | return 0; |
3993f6b1 DJ |
627 | } |
628 | ||
f6ac5f3d PA |
629 | int |
630 | linux_nat_target::remove_exec_catchpoint (int pid) | |
eb73ad13 PA |
631 | { |
632 | return 0; | |
633 | } | |
634 | ||
f6ac5f3d PA |
635 | int |
636 | linux_nat_target::set_syscall_catchpoint (int pid, bool needed, int any_count, | |
637 | gdb::array_view<const int> syscall_counts) | |
a96d9b2e | 638 | { |
a96d9b2e SDJ |
639 | /* On GNU/Linux, we ignore the arguments. It means that we only |
640 | enable the syscall catchpoints, but do not disable them. | |
77b06cd7 | 641 | |
649a140c | 642 | Also, we do not use the `syscall_counts' information because we do not |
a96d9b2e SDJ |
643 | filter system calls here. We let GDB do the logic for us. */ |
644 | return 0; | |
645 | } | |
646 | ||
774113b0 PA |
647 | /* List of known LWPs, keyed by LWP PID. This speeds up the common |
648 | case of mapping a PID returned from the kernel to our corresponding | |
649 | lwp_info data structure. */ | |
650 | static htab_t lwp_lwpid_htab; | |
651 | ||
652 | /* Calculate a hash from a lwp_info's LWP PID. */ | |
653 | ||
654 | static hashval_t | |
655 | lwp_info_hash (const void *ap) | |
656 | { | |
657 | const struct lwp_info *lp = (struct lwp_info *) ap; | |
e38504b3 | 658 | pid_t pid = lp->ptid.lwp (); |
774113b0 PA |
659 | |
660 | return iterative_hash_object (pid, 0); | |
661 | } | |
662 | ||
663 | /* Equality function for the lwp_info hash table. Compares the LWP's | |
664 | PID. */ | |
665 | ||
666 | static int | |
667 | lwp_lwpid_htab_eq (const void *a, const void *b) | |
668 | { | |
669 | const struct lwp_info *entry = (const struct lwp_info *) a; | |
670 | const struct lwp_info *element = (const struct lwp_info *) b; | |
671 | ||
e38504b3 | 672 | return entry->ptid.lwp () == element->ptid.lwp (); |
774113b0 PA |
673 | } |
674 | ||
675 | /* Create the lwp_lwpid_htab hash table. */ | |
676 | ||
677 | static void | |
678 | lwp_lwpid_htab_create (void) | |
679 | { | |
680 | lwp_lwpid_htab = htab_create (100, lwp_info_hash, lwp_lwpid_htab_eq, NULL); | |
681 | } | |
682 | ||
683 | /* Add LP to the hash table. */ | |
684 | ||
685 | static void | |
686 | lwp_lwpid_htab_add_lwp (struct lwp_info *lp) | |
687 | { | |
688 | void **slot; | |
689 | ||
690 | slot = htab_find_slot (lwp_lwpid_htab, lp, INSERT); | |
691 | gdb_assert (slot != NULL && *slot == NULL); | |
692 | *slot = lp; | |
693 | } | |
694 | ||
695 | /* Head of doubly-linked list of known LWPs. Sorted by reverse | |
696 | creation order. This order is assumed in some cases. E.g., | |
697 | reaping status after killing alls lwps of a process: the leader LWP | |
698 | must be reaped last. */ | |
901b9821 SM |
699 | |
700 | static intrusive_list<lwp_info> lwp_list; | |
701 | ||
702 | /* See linux-nat.h. */ | |
703 | ||
704 | lwp_info_range | |
705 | all_lwps () | |
706 | { | |
707 | return lwp_info_range (lwp_list.begin ()); | |
708 | } | |
709 | ||
710 | /* See linux-nat.h. */ | |
711 | ||
712 | lwp_info_safe_range | |
713 | all_lwps_safe () | |
714 | { | |
715 | return lwp_info_safe_range (lwp_list.begin ()); | |
716 | } | |
774113b0 PA |
717 | |
718 | /* Add LP to sorted-by-reverse-creation-order doubly-linked list. */ | |
719 | ||
720 | static void | |
721 | lwp_list_add (struct lwp_info *lp) | |
722 | { | |
901b9821 | 723 | lwp_list.push_front (*lp); |
774113b0 PA |
724 | } |
725 | ||
726 | /* Remove LP from sorted-by-reverse-creation-order doubly-linked | |
727 | list. */ | |
728 | ||
729 | static void | |
730 | lwp_list_remove (struct lwp_info *lp) | |
731 | { | |
732 | /* Remove from sorted-by-creation-order list. */ | |
901b9821 | 733 | lwp_list.erase (lwp_list.iterator_to (*lp)); |
774113b0 PA |
734 | } |
735 | ||
d6b0e80f AC |
736 | \f |
737 | ||
d6b0e80f AC |
738 | /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in |
739 | _initialize_linux_nat. */ | |
740 | static sigset_t suspend_mask; | |
741 | ||
7feb7d06 PA |
742 | /* Signals to block to make that sigsuspend work. */ |
743 | static sigset_t blocked_mask; | |
744 | ||
745 | /* SIGCHLD action. */ | |
6bd434d6 | 746 | static struct sigaction sigchld_action; |
b84876c2 | 747 | |
7feb7d06 PA |
748 | /* Block child signals (SIGCHLD and linux threads signals), and store |
749 | the previous mask in PREV_MASK. */ | |
84e46146 | 750 | |
7feb7d06 PA |
751 | static void |
752 | block_child_signals (sigset_t *prev_mask) | |
753 | { | |
754 | /* Make sure SIGCHLD is blocked. */ | |
755 | if (!sigismember (&blocked_mask, SIGCHLD)) | |
756 | sigaddset (&blocked_mask, SIGCHLD); | |
757 | ||
21987b9c | 758 | gdb_sigmask (SIG_BLOCK, &blocked_mask, prev_mask); |
7feb7d06 PA |
759 | } |
760 | ||
761 | /* Restore child signals mask, previously returned by | |
762 | block_child_signals. */ | |
763 | ||
764 | static void | |
765 | restore_child_signals_mask (sigset_t *prev_mask) | |
766 | { | |
21987b9c | 767 | gdb_sigmask (SIG_SETMASK, prev_mask, NULL); |
7feb7d06 | 768 | } |
2455069d UW |
769 | |
770 | /* Mask of signals to pass directly to the inferior. */ | |
771 | static sigset_t pass_mask; | |
772 | ||
773 | /* Update signals to pass to the inferior. */ | |
f6ac5f3d | 774 | void |
adc6a863 PA |
775 | linux_nat_target::pass_signals |
776 | (gdb::array_view<const unsigned char> pass_signals) | |
2455069d UW |
777 | { |
778 | int signo; | |
779 | ||
780 | sigemptyset (&pass_mask); | |
781 | ||
782 | for (signo = 1; signo < NSIG; signo++) | |
783 | { | |
2ea28649 | 784 | int target_signo = gdb_signal_from_host (signo); |
adc6a863 | 785 | if (target_signo < pass_signals.size () && pass_signals[target_signo]) |
dda83cd7 | 786 | sigaddset (&pass_mask, signo); |
2455069d UW |
787 | } |
788 | } | |
789 | ||
d6b0e80f AC |
790 | \f |
791 | ||
792 | /* Prototypes for local functions. */ | |
d3a70e03 TT |
793 | static int stop_wait_callback (struct lwp_info *lp); |
794 | static int resume_stopped_resumed_lwps (struct lwp_info *lp, const ptid_t wait_ptid); | |
ced2dffb | 795 | static int check_ptrace_stopped_lwp_gone (struct lwp_info *lp); |
710151dd | 796 | |
d6b0e80f | 797 | \f |
d6b0e80f | 798 | |
7b50312a PA |
799 | /* Destroy and free LP. */ |
800 | ||
676362df | 801 | lwp_info::~lwp_info () |
7b50312a | 802 | { |
466eecee | 803 | /* Let the arch specific bits release arch_lwp_info. */ |
676362df | 804 | linux_target->low_delete_thread (this->arch_private); |
7b50312a PA |
805 | } |
806 | ||
774113b0 | 807 | /* Traversal function for purge_lwp_list. */ |
d90e17a7 | 808 | |
774113b0 PA |
809 | static int |
810 | lwp_lwpid_htab_remove_pid (void **slot, void *info) | |
d90e17a7 | 811 | { |
774113b0 PA |
812 | struct lwp_info *lp = (struct lwp_info *) *slot; |
813 | int pid = *(int *) info; | |
d90e17a7 | 814 | |
e99b03dc | 815 | if (lp->ptid.pid () == pid) |
d90e17a7 | 816 | { |
774113b0 PA |
817 | htab_clear_slot (lwp_lwpid_htab, slot); |
818 | lwp_list_remove (lp); | |
676362df | 819 | delete lp; |
774113b0 | 820 | } |
d90e17a7 | 821 | |
774113b0 PA |
822 | return 1; |
823 | } | |
d90e17a7 | 824 | |
774113b0 PA |
825 | /* Remove all LWPs belong to PID from the lwp list. */ |
826 | ||
827 | static void | |
828 | purge_lwp_list (int pid) | |
829 | { | |
830 | htab_traverse_noresize (lwp_lwpid_htab, lwp_lwpid_htab_remove_pid, &pid); | |
d90e17a7 PA |
831 | } |
832 | ||
26cb8b7c PA |
833 | /* Add the LWP specified by PTID to the list. PTID is the first LWP |
834 | in the process. Return a pointer to the structure describing the | |
835 | new LWP. | |
836 | ||
837 | This differs from add_lwp in that we don't let the arch specific | |
838 | bits know about this new thread. Current clients of this callback | |
839 | take the opportunity to install watchpoints in the new thread, and | |
840 | we shouldn't do that for the first thread. If we're spawning a | |
841 | child ("run"), the thread executes the shell wrapper first, and we | |
842 | shouldn't touch it until it execs the program we want to debug. | |
843 | For "attach", it'd be okay to call the callback, but it's not | |
844 | necessary, because watchpoints can't yet have been inserted into | |
845 | the inferior. */ | |
d6b0e80f AC |
846 | |
847 | static struct lwp_info * | |
26cb8b7c | 848 | add_initial_lwp (ptid_t ptid) |
d6b0e80f | 849 | { |
15a9e13e | 850 | gdb_assert (ptid.lwp_p ()); |
d6b0e80f | 851 | |
b0f6c8d2 | 852 | lwp_info *lp = new lwp_info (ptid); |
d6b0e80f | 853 | |
d6b0e80f | 854 | |
774113b0 PA |
855 | /* Add to sorted-by-reverse-creation-order list. */ |
856 | lwp_list_add (lp); | |
857 | ||
858 | /* Add to keyed-by-pid htab. */ | |
859 | lwp_lwpid_htab_add_lwp (lp); | |
d6b0e80f | 860 | |
26cb8b7c PA |
861 | return lp; |
862 | } | |
863 | ||
864 | /* Add the LWP specified by PID to the list. Return a pointer to the | |
865 | structure describing the new LWP. The LWP should already be | |
866 | stopped. */ | |
867 | ||
868 | static struct lwp_info * | |
869 | add_lwp (ptid_t ptid) | |
870 | { | |
871 | struct lwp_info *lp; | |
872 | ||
873 | lp = add_initial_lwp (ptid); | |
874 | ||
6e012a6c PA |
875 | /* Let the arch specific bits know about this new thread. Current |
876 | clients of this callback take the opportunity to install | |
26cb8b7c PA |
877 | watchpoints in the new thread. We don't do this for the first |
878 | thread though. See add_initial_lwp. */ | |
135340af | 879 | linux_target->low_new_thread (lp); |
9f0bdab8 | 880 | |
d6b0e80f AC |
881 | return lp; |
882 | } | |
883 | ||
884 | /* Remove the LWP specified by PID from the list. */ | |
885 | ||
886 | static void | |
887 | delete_lwp (ptid_t ptid) | |
888 | { | |
b0f6c8d2 | 889 | lwp_info dummy (ptid); |
d6b0e80f | 890 | |
b0f6c8d2 | 891 | void **slot = htab_find_slot (lwp_lwpid_htab, &dummy, NO_INSERT); |
774113b0 PA |
892 | if (slot == NULL) |
893 | return; | |
d6b0e80f | 894 | |
b0f6c8d2 | 895 | lwp_info *lp = *(struct lwp_info **) slot; |
774113b0 | 896 | gdb_assert (lp != NULL); |
d6b0e80f | 897 | |
774113b0 | 898 | htab_clear_slot (lwp_lwpid_htab, slot); |
d6b0e80f | 899 | |
774113b0 PA |
900 | /* Remove from sorted-by-creation-order list. */ |
901 | lwp_list_remove (lp); | |
d6b0e80f | 902 | |
774113b0 | 903 | /* Release. */ |
676362df | 904 | delete lp; |
d6b0e80f AC |
905 | } |
906 | ||
907 | /* Return a pointer to the structure describing the LWP corresponding | |
908 | to PID. If no corresponding LWP could be found, return NULL. */ | |
909 | ||
910 | static struct lwp_info * | |
911 | find_lwp_pid (ptid_t ptid) | |
912 | { | |
d6b0e80f AC |
913 | int lwp; |
914 | ||
15a9e13e | 915 | if (ptid.lwp_p ()) |
e38504b3 | 916 | lwp = ptid.lwp (); |
d6b0e80f | 917 | else |
e99b03dc | 918 | lwp = ptid.pid (); |
d6b0e80f | 919 | |
b0f6c8d2 SM |
920 | lwp_info dummy (ptid_t (0, lwp)); |
921 | return (struct lwp_info *) htab_find (lwp_lwpid_htab, &dummy); | |
d6b0e80f AC |
922 | } |
923 | ||
6d4ee8c6 | 924 | /* See nat/linux-nat.h. */ |
d6b0e80f AC |
925 | |
926 | struct lwp_info * | |
d90e17a7 | 927 | iterate_over_lwps (ptid_t filter, |
d3a70e03 | 928 | gdb::function_view<iterate_over_lwps_ftype> callback) |
d6b0e80f | 929 | { |
901b9821 | 930 | for (lwp_info *lp : all_lwps_safe ()) |
d6b0e80f | 931 | { |
26a57c92 | 932 | if (lp->ptid.matches (filter)) |
d90e17a7 | 933 | { |
d3a70e03 | 934 | if (callback (lp) != 0) |
d90e17a7 PA |
935 | return lp; |
936 | } | |
d6b0e80f AC |
937 | } |
938 | ||
939 | return NULL; | |
940 | } | |
941 | ||
2277426b PA |
942 | /* Update our internal state when changing from one checkpoint to |
943 | another indicated by NEW_PTID. We can only switch single-threaded | |
944 | applications, so we only create one new LWP, and the previous list | |
945 | is discarded. */ | |
f973ed9c DJ |
946 | |
947 | void | |
948 | linux_nat_switch_fork (ptid_t new_ptid) | |
949 | { | |
950 | struct lwp_info *lp; | |
951 | ||
e99b03dc | 952 | purge_lwp_list (inferior_ptid.pid ()); |
2277426b | 953 | |
f973ed9c DJ |
954 | lp = add_lwp (new_ptid); |
955 | lp->stopped = 1; | |
e26af52f | 956 | |
2277426b PA |
957 | /* This changes the thread's ptid while preserving the gdb thread |
958 | num. Also changes the inferior pid, while preserving the | |
959 | inferior num. */ | |
5b6d1e4f | 960 | thread_change_ptid (linux_target, inferior_ptid, new_ptid); |
2277426b PA |
961 | |
962 | /* We've just told GDB core that the thread changed target id, but, | |
963 | in fact, it really is a different thread, with different register | |
964 | contents. */ | |
965 | registers_changed (); | |
e26af52f DJ |
966 | } |
967 | ||
7730e5c6 PA |
968 | /* Handle the exit of a single thread LP. If DEL_THREAD is true, |
969 | delete the thread_info associated to LP, if it exists. */ | |
e26af52f DJ |
970 | |
971 | static void | |
7730e5c6 | 972 | exit_lwp (struct lwp_info *lp, bool del_thread = true) |
e26af52f | 973 | { |
9213a6d7 | 974 | struct thread_info *th = linux_target->find_thread (lp->ptid); |
063bfe2e | 975 | |
7730e5c6 | 976 | if (th != nullptr && del_thread) |
9d7d58e7 | 977 | delete_thread (th); |
e26af52f DJ |
978 | |
979 | delete_lwp (lp->ptid); | |
980 | } | |
981 | ||
a0ef4274 DJ |
982 | /* Wait for the LWP specified by LP, which we have just attached to. |
983 | Returns a wait status for that LWP, to cache. */ | |
984 | ||
985 | static int | |
22827c51 | 986 | linux_nat_post_attach_wait (ptid_t ptid, int *signalled) |
a0ef4274 | 987 | { |
e38504b3 | 988 | pid_t new_pid, pid = ptid.lwp (); |
a0ef4274 DJ |
989 | int status; |
990 | ||
644cebc9 | 991 | if (linux_proc_pid_is_stopped (pid)) |
a0ef4274 | 992 | { |
9327494e | 993 | linux_nat_debug_printf ("Attaching to a stopped process"); |
a0ef4274 DJ |
994 | |
995 | /* The process is definitely stopped. It is in a job control | |
996 | stop, unless the kernel predates the TASK_STOPPED / | |
997 | TASK_TRACED distinction, in which case it might be in a | |
998 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
999 | can kill it, signal it, et cetera. | |
1000 | ||
dda83cd7 | 1001 | First make sure there is a pending SIGSTOP. Since we are |
a0ef4274 DJ |
1002 | already attached, the process can not transition from stopped |
1003 | to running without a PTRACE_CONT; so we know this signal will | |
1004 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
1005 | probably already in the queue (unless this kernel is old | |
1006 | enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP | |
1007 | is not an RT signal, it can only be queued once. */ | |
1008 | kill_lwp (pid, SIGSTOP); | |
1009 | ||
1010 | /* Finally, resume the stopped process. This will deliver the SIGSTOP | |
1011 | (or a higher priority signal, just like normal PTRACE_ATTACH). */ | |
1012 | ptrace (PTRACE_CONT, pid, 0, 0); | |
1013 | } | |
1014 | ||
1015 | /* Make sure the initial process is stopped. The user-level threads | |
1016 | layer might want to poke around in the inferior, and that won't | |
1017 | work if things haven't stabilized yet. */ | |
4a6ed09b | 1018 | new_pid = my_waitpid (pid, &status, __WALL); |
dacc9cb2 PP |
1019 | gdb_assert (pid == new_pid); |
1020 | ||
1021 | if (!WIFSTOPPED (status)) | |
1022 | { | |
1023 | /* The pid we tried to attach has apparently just exited. */ | |
9327494e | 1024 | linux_nat_debug_printf ("Failed to stop %d: %s", pid, |
8d06918f | 1025 | status_to_str (status).c_str ()); |
dacc9cb2 PP |
1026 | return status; |
1027 | } | |
a0ef4274 DJ |
1028 | |
1029 | if (WSTOPSIG (status) != SIGSTOP) | |
1030 | { | |
1031 | *signalled = 1; | |
9327494e | 1032 | linux_nat_debug_printf ("Received %s after attaching", |
8d06918f | 1033 | status_to_str (status).c_str ()); |
a0ef4274 DJ |
1034 | } |
1035 | ||
1036 | return status; | |
1037 | } | |
1038 | ||
f6ac5f3d PA |
1039 | void |
1040 | linux_nat_target::create_inferior (const char *exec_file, | |
1041 | const std::string &allargs, | |
1042 | char **env, int from_tty) | |
b84876c2 | 1043 | { |
41272101 TT |
1044 | maybe_disable_address_space_randomization restore_personality |
1045 | (disable_randomization); | |
b84876c2 PA |
1046 | |
1047 | /* The fork_child mechanism is synchronous and calls target_wait, so | |
1048 | we have to mask the async mode. */ | |
1049 | ||
2455069d | 1050 | /* Make sure we report all signals during startup. */ |
adc6a863 | 1051 | pass_signals ({}); |
2455069d | 1052 | |
f6ac5f3d | 1053 | inf_ptrace_target::create_inferior (exec_file, allargs, env, from_tty); |
8a89ddbd PA |
1054 | |
1055 | open_proc_mem_file (inferior_ptid); | |
b84876c2 PA |
1056 | } |
1057 | ||
8784d563 PA |
1058 | /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not |
1059 | already attached. Returns true if a new LWP is found, false | |
1060 | otherwise. */ | |
1061 | ||
1062 | static int | |
1063 | attach_proc_task_lwp_callback (ptid_t ptid) | |
1064 | { | |
1065 | struct lwp_info *lp; | |
1066 | ||
1067 | /* Ignore LWPs we're already attached to. */ | |
1068 | lp = find_lwp_pid (ptid); | |
1069 | if (lp == NULL) | |
1070 | { | |
e38504b3 | 1071 | int lwpid = ptid.lwp (); |
8784d563 PA |
1072 | |
1073 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) | |
1074 | { | |
1075 | int err = errno; | |
1076 | ||
1077 | /* Be quiet if we simply raced with the thread exiting. | |
1078 | EPERM is returned if the thread's task still exists, and | |
1079 | is marked as exited or zombie, as well as other | |
1080 | conditions, so in that case, confirm the status in | |
1081 | /proc/PID/status. */ | |
1082 | if (err == ESRCH | |
1083 | || (err == EPERM && linux_proc_pid_is_gone (lwpid))) | |
1084 | { | |
9327494e SM |
1085 | linux_nat_debug_printf |
1086 | ("Cannot attach to lwp %d: thread is gone (%d: %s)", | |
1087 | lwpid, err, safe_strerror (err)); | |
1088 | ||
8784d563 PA |
1089 | } |
1090 | else | |
1091 | { | |
4d9b86e1 | 1092 | std::string reason |
50fa3001 | 1093 | = linux_ptrace_attach_fail_reason_string (ptid, err); |
4d9b86e1 | 1094 | |
c6f7f9c8 TT |
1095 | error (_("Cannot attach to lwp %d: %s"), |
1096 | lwpid, reason.c_str ()); | |
8784d563 PA |
1097 | } |
1098 | } | |
1099 | else | |
1100 | { | |
9327494e | 1101 | linux_nat_debug_printf ("PTRACE_ATTACH %s, 0, 0 (OK)", |
e53c95d4 | 1102 | ptid.to_string ().c_str ()); |
8784d563 PA |
1103 | |
1104 | lp = add_lwp (ptid); | |
8784d563 PA |
1105 | |
1106 | /* The next time we wait for this LWP we'll see a SIGSTOP as | |
1107 | PTRACE_ATTACH brings it to a halt. */ | |
1108 | lp->signalled = 1; | |
1109 | ||
1110 | /* We need to wait for a stop before being able to make the | |
1111 | next ptrace call on this LWP. */ | |
1112 | lp->must_set_ptrace_flags = 1; | |
026a9174 PA |
1113 | |
1114 | /* So that wait collects the SIGSTOP. */ | |
1115 | lp->resumed = 1; | |
8784d563 PA |
1116 | } |
1117 | ||
1118 | return 1; | |
1119 | } | |
1120 | return 0; | |
1121 | } | |
1122 | ||
f6ac5f3d PA |
1123 | void |
1124 | linux_nat_target::attach (const char *args, int from_tty) | |
d6b0e80f AC |
1125 | { |
1126 | struct lwp_info *lp; | |
d6b0e80f | 1127 | int status; |
af990527 | 1128 | ptid_t ptid; |
d6b0e80f | 1129 | |
2455069d | 1130 | /* Make sure we report all signals during attach. */ |
adc6a863 | 1131 | pass_signals ({}); |
2455069d | 1132 | |
a70b8144 | 1133 | try |
87b0bb13 | 1134 | { |
f6ac5f3d | 1135 | inf_ptrace_target::attach (args, from_tty); |
87b0bb13 | 1136 | } |
230d2906 | 1137 | catch (const gdb_exception_error &ex) |
87b0bb13 JK |
1138 | { |
1139 | pid_t pid = parse_pid_to_attach (args); | |
50fa3001 | 1140 | std::string reason = linux_ptrace_attach_fail_reason (pid); |
87b0bb13 | 1141 | |
4d9b86e1 | 1142 | if (!reason.empty ()) |
3d6e9d23 TT |
1143 | throw_error (ex.error, "warning: %s\n%s", reason.c_str (), |
1144 | ex.what ()); | |
7ae1a6a6 | 1145 | else |
3d6e9d23 | 1146 | throw_error (ex.error, "%s", ex.what ()); |
87b0bb13 | 1147 | } |
d6b0e80f | 1148 | |
af990527 PA |
1149 | /* The ptrace base target adds the main thread with (pid,0,0) |
1150 | format. Decorate it with lwp info. */ | |
e99b03dc | 1151 | ptid = ptid_t (inferior_ptid.pid (), |
184ea2f7 | 1152 | inferior_ptid.pid ()); |
5b6d1e4f | 1153 | thread_change_ptid (linux_target, inferior_ptid, ptid); |
af990527 | 1154 | |
9f0bdab8 | 1155 | /* Add the initial process as the first LWP to the list. */ |
26cb8b7c | 1156 | lp = add_initial_lwp (ptid); |
a0ef4274 | 1157 | |
22827c51 | 1158 | status = linux_nat_post_attach_wait (lp->ptid, &lp->signalled); |
dacc9cb2 PP |
1159 | if (!WIFSTOPPED (status)) |
1160 | { | |
1161 | if (WIFEXITED (status)) | |
1162 | { | |
1163 | int exit_code = WEXITSTATUS (status); | |
1164 | ||
223ffa71 | 1165 | target_terminal::ours (); |
bc1e6c81 | 1166 | target_mourn_inferior (inferior_ptid); |
dacc9cb2 PP |
1167 | if (exit_code == 0) |
1168 | error (_("Unable to attach: program exited normally.")); | |
1169 | else | |
1170 | error (_("Unable to attach: program exited with code %d."), | |
1171 | exit_code); | |
1172 | } | |
1173 | else if (WIFSIGNALED (status)) | |
1174 | { | |
2ea28649 | 1175 | enum gdb_signal signo; |
dacc9cb2 | 1176 | |
223ffa71 | 1177 | target_terminal::ours (); |
bc1e6c81 | 1178 | target_mourn_inferior (inferior_ptid); |
dacc9cb2 | 1179 | |
2ea28649 | 1180 | signo = gdb_signal_from_host (WTERMSIG (status)); |
dacc9cb2 PP |
1181 | error (_("Unable to attach: program terminated with signal " |
1182 | "%s, %s."), | |
2ea28649 PA |
1183 | gdb_signal_to_name (signo), |
1184 | gdb_signal_to_string (signo)); | |
dacc9cb2 PP |
1185 | } |
1186 | ||
f34652de | 1187 | internal_error (_("unexpected status %d for PID %ld"), |
e38504b3 | 1188 | status, (long) ptid.lwp ()); |
dacc9cb2 PP |
1189 | } |
1190 | ||
a0ef4274 | 1191 | lp->stopped = 1; |
9f0bdab8 | 1192 | |
8a89ddbd PA |
1193 | open_proc_mem_file (lp->ptid); |
1194 | ||
a0ef4274 | 1195 | /* Save the wait status to report later. */ |
d6b0e80f | 1196 | lp->resumed = 1; |
9327494e | 1197 | linux_nat_debug_printf ("waitpid %ld, saving status %s", |
8d06918f SM |
1198 | (long) lp->ptid.pid (), |
1199 | status_to_str (status).c_str ()); | |
710151dd | 1200 | |
7feb7d06 PA |
1201 | lp->status = status; |
1202 | ||
8784d563 PA |
1203 | /* We must attach to every LWP. If /proc is mounted, use that to |
1204 | find them now. The inferior may be using raw clone instead of | |
1205 | using pthreads. But even if it is using pthreads, thread_db | |
1206 | walks structures in the inferior's address space to find the list | |
1207 | of threads/LWPs, and those structures may well be corrupted. | |
1208 | Note that once thread_db is loaded, we'll still use it to list | |
1209 | threads and associate pthread info with each LWP. */ | |
c6f7f9c8 TT |
1210 | try |
1211 | { | |
1212 | linux_proc_attach_tgid_threads (lp->ptid.pid (), | |
1213 | attach_proc_task_lwp_callback); | |
1214 | } | |
1215 | catch (const gdb_exception_error &) | |
1216 | { | |
1217 | /* Failed to attach to some LWP. Detach any we've already | |
1218 | attached to. */ | |
1219 | iterate_over_lwps (ptid_t (ptid.pid ()), | |
1220 | [] (struct lwp_info *lwp) -> int | |
1221 | { | |
1222 | /* Ignore errors when detaching. */ | |
1223 | ptrace (PTRACE_DETACH, lwp->ptid.lwp (), 0, 0); | |
1224 | delete_lwp (lwp->ptid); | |
1225 | return 0; | |
1226 | }); | |
1227 | ||
1228 | target_terminal::ours (); | |
1229 | target_mourn_inferior (inferior_ptid); | |
1230 | ||
1231 | throw; | |
1232 | } | |
1233 | ||
1234 | /* Add all the LWPs to gdb's thread list. */ | |
1235 | iterate_over_lwps (ptid_t (ptid.pid ()), | |
1236 | [] (struct lwp_info *lwp) -> int | |
1237 | { | |
1238 | if (lwp->ptid.pid () != lwp->ptid.lwp ()) | |
1239 | { | |
1240 | add_thread (linux_target, lwp->ptid); | |
1241 | set_running (linux_target, lwp->ptid, true); | |
1242 | set_executing (linux_target, lwp->ptid, true); | |
1243 | } | |
1244 | return 0; | |
1245 | }); | |
d6b0e80f AC |
1246 | } |
1247 | ||
4a3ee32a SM |
1248 | /* Ptrace-detach the thread with pid PID. */ |
1249 | ||
1250 | static void | |
1251 | detach_one_pid (int pid, int signo) | |
1252 | { | |
1253 | if (ptrace (PTRACE_DETACH, pid, 0, signo) < 0) | |
1254 | { | |
1255 | int save_errno = errno; | |
1256 | ||
1257 | /* We know the thread exists, so ESRCH must mean the lwp is | |
1258 | zombie. This can happen if one of the already-detached | |
1259 | threads exits the whole thread group. In that case we're | |
1260 | still attached, and must reap the lwp. */ | |
1261 | if (save_errno == ESRCH) | |
1262 | { | |
1263 | int ret, status; | |
1264 | ||
1265 | ret = my_waitpid (pid, &status, __WALL); | |
1266 | if (ret == -1) | |
1267 | { | |
1268 | warning (_("Couldn't reap LWP %d while detaching: %s"), | |
1269 | pid, safe_strerror (errno)); | |
1270 | } | |
1271 | else if (!WIFEXITED (status) && !WIFSIGNALED (status)) | |
1272 | { | |
1273 | warning (_("Reaping LWP %d while detaching " | |
1274 | "returned unexpected status 0x%x"), | |
1275 | pid, status); | |
1276 | } | |
1277 | } | |
1278 | else | |
1279 | error (_("Can't detach %d: %s"), | |
1280 | pid, safe_strerror (save_errno)); | |
1281 | } | |
1282 | else | |
1283 | linux_nat_debug_printf ("PTRACE_DETACH (%d, %s, 0) (OK)", | |
1284 | pid, strsignal (signo)); | |
1285 | } | |
1286 | ||
ced2dffb PA |
1287 | /* Get pending signal of THREAD as a host signal number, for detaching |
1288 | purposes. This is the signal the thread last stopped for, which we | |
1289 | need to deliver to the thread when detaching, otherwise, it'd be | |
1290 | suppressed/lost. */ | |
1291 | ||
a0ef4274 | 1292 | static int |
ced2dffb | 1293 | get_detach_signal (struct lwp_info *lp) |
a0ef4274 | 1294 | { |
a493e3e2 | 1295 | enum gdb_signal signo = GDB_SIGNAL_0; |
ca2163eb PA |
1296 | |
1297 | /* If we paused threads momentarily, we may have stored pending | |
1298 | events in lp->status or lp->waitstatus (see stop_wait_callback), | |
1299 | and GDB core hasn't seen any signal for those threads. | |
1300 | Otherwise, the last signal reported to the core is found in the | |
1301 | thread object's stop_signal. | |
1302 | ||
1303 | There's a corner case that isn't handled here at present. Only | |
1304 | if the thread stopped with a TARGET_WAITKIND_STOPPED does | |
1305 | stop_signal make sense as a real signal to pass to the inferior. | |
1306 | Some catchpoint related events, like | |
1307 | TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set | |
a493e3e2 | 1308 | to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But, |
ca2163eb PA |
1309 | those traps are debug API (ptrace in our case) related and |
1310 | induced; the inferior wouldn't see them if it wasn't being | |
1311 | traced. Hence, we should never pass them to the inferior, even | |
1312 | when set to pass state. Since this corner case isn't handled by | |
1313 | infrun.c when proceeding with a signal, for consistency, neither | |
1314 | do we handle it here (or elsewhere in the file we check for | |
1315 | signal pass state). Normally SIGTRAP isn't set to pass state, so | |
1316 | this is really a corner case. */ | |
1317 | ||
183be222 | 1318 | if (lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE) |
a493e3e2 | 1319 | signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */ |
ca2163eb | 1320 | else if (lp->status) |
2ea28649 | 1321 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
00431a78 | 1322 | else |
ca2163eb | 1323 | { |
9213a6d7 | 1324 | thread_info *tp = linux_target->find_thread (lp->ptid); |
e0881a8e | 1325 | |
611841bb | 1326 | if (target_is_non_stop_p () && !tp->executing ()) |
ca2163eb | 1327 | { |
1edb66d8 | 1328 | if (tp->has_pending_waitstatus ()) |
df5ad102 SM |
1329 | { |
1330 | /* If the thread has a pending event, and it was stopped with a | |
287de656 | 1331 | signal, use that signal to resume it. If it has a pending |
df5ad102 SM |
1332 | event of another kind, it was not stopped with a signal, so |
1333 | resume it without a signal. */ | |
1334 | if (tp->pending_waitstatus ().kind () == TARGET_WAITKIND_STOPPED) | |
1335 | signo = tp->pending_waitstatus ().sig (); | |
1336 | else | |
1337 | signo = GDB_SIGNAL_0; | |
1338 | } | |
00431a78 | 1339 | else |
1edb66d8 | 1340 | signo = tp->stop_signal (); |
00431a78 PA |
1341 | } |
1342 | else if (!target_is_non_stop_p ()) | |
1343 | { | |
00431a78 | 1344 | ptid_t last_ptid; |
5b6d1e4f | 1345 | process_stratum_target *last_target; |
00431a78 | 1346 | |
5b6d1e4f | 1347 | get_last_target_status (&last_target, &last_ptid, nullptr); |
e0881a8e | 1348 | |
5b6d1e4f PA |
1349 | if (last_target == linux_target |
1350 | && lp->ptid.lwp () == last_ptid.lwp ()) | |
1edb66d8 | 1351 | signo = tp->stop_signal (); |
4c28f408 | 1352 | } |
ca2163eb | 1353 | } |
4c28f408 | 1354 | |
a493e3e2 | 1355 | if (signo == GDB_SIGNAL_0) |
ca2163eb | 1356 | { |
9327494e | 1357 | linux_nat_debug_printf ("lwp %s has no pending signal", |
e53c95d4 | 1358 | lp->ptid.to_string ().c_str ()); |
ca2163eb PA |
1359 | } |
1360 | else if (!signal_pass_state (signo)) | |
1361 | { | |
9327494e SM |
1362 | linux_nat_debug_printf |
1363 | ("lwp %s had signal %s but it is in no pass state", | |
e53c95d4 | 1364 | lp->ptid.to_string ().c_str (), gdb_signal_to_string (signo)); |
a0ef4274 | 1365 | } |
a0ef4274 | 1366 | else |
4c28f408 | 1367 | { |
9327494e | 1368 | linux_nat_debug_printf ("lwp %s has pending signal %s", |
e53c95d4 | 1369 | lp->ptid.to_string ().c_str (), |
9327494e | 1370 | gdb_signal_to_string (signo)); |
ced2dffb PA |
1371 | |
1372 | return gdb_signal_to_host (signo); | |
4c28f408 | 1373 | } |
a0ef4274 DJ |
1374 | |
1375 | return 0; | |
1376 | } | |
1377 | ||
0d36baa9 | 1378 | /* If LP has a pending fork/vfork/clone status, return it. */ |
ced2dffb | 1379 | |
6b09f134 | 1380 | static std::optional<target_waitstatus> |
0d36baa9 | 1381 | get_pending_child_status (lwp_info *lp) |
d6b0e80f | 1382 | { |
b26b06dd AB |
1383 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
1384 | ||
1385 | linux_nat_debug_printf ("lwp %s (stopped = %d)", | |
1386 | lp->ptid.to_string ().c_str (), lp->stopped); | |
1387 | ||
df5ad102 SM |
1388 | /* Check in lwp_info::status. */ |
1389 | if (WIFSTOPPED (lp->status) && linux_is_extended_waitstatus (lp->status)) | |
1390 | { | |
1391 | int event = linux_ptrace_get_extended_event (lp->status); | |
1392 | ||
0d36baa9 PA |
1393 | if (event == PTRACE_EVENT_FORK |
1394 | || event == PTRACE_EVENT_VFORK | |
1395 | || event == PTRACE_EVENT_CLONE) | |
df5ad102 SM |
1396 | { |
1397 | unsigned long child_pid; | |
1398 | int ret = ptrace (PTRACE_GETEVENTMSG, lp->ptid.lwp (), 0, &child_pid); | |
1399 | if (ret == 0) | |
0d36baa9 PA |
1400 | { |
1401 | target_waitstatus ws; | |
1402 | ||
1403 | if (event == PTRACE_EVENT_FORK) | |
1404 | ws.set_forked (ptid_t (child_pid, child_pid)); | |
1405 | else if (event == PTRACE_EVENT_VFORK) | |
1406 | ws.set_vforked (ptid_t (child_pid, child_pid)); | |
1407 | else if (event == PTRACE_EVENT_CLONE) | |
1408 | ws.set_thread_cloned (ptid_t (lp->ptid.pid (), child_pid)); | |
1409 | else | |
1410 | gdb_assert_not_reached ("unhandled"); | |
1411 | ||
1412 | return ws; | |
1413 | } | |
df5ad102 | 1414 | else |
0d36baa9 PA |
1415 | { |
1416 | perror_warning_with_name (_("Failed to retrieve event msg")); | |
1417 | return {}; | |
1418 | } | |
df5ad102 SM |
1419 | } |
1420 | } | |
1421 | ||
1422 | /* Check in lwp_info::waitstatus. */ | |
0d36baa9 PA |
1423 | if (is_new_child_status (lp->waitstatus.kind ())) |
1424 | return lp->waitstatus; | |
df5ad102 | 1425 | |
9213a6d7 | 1426 | thread_info *tp = linux_target->find_thread (lp->ptid); |
df5ad102 | 1427 | |
0d36baa9 PA |
1428 | /* Check in thread_info::pending_waitstatus. */ |
1429 | if (tp->has_pending_waitstatus () | |
1430 | && is_new_child_status (tp->pending_waitstatus ().kind ())) | |
1431 | return tp->pending_waitstatus (); | |
df5ad102 SM |
1432 | |
1433 | /* Check in thread_info::pending_follow. */ | |
0d36baa9 PA |
1434 | if (is_new_child_status (tp->pending_follow.kind ())) |
1435 | return tp->pending_follow; | |
df5ad102 | 1436 | |
0d36baa9 PA |
1437 | return {}; |
1438 | } | |
1439 | ||
1440 | /* Detach from LP. If SIGNO_P is non-NULL, then it points to the | |
1441 | signal number that should be passed to the LWP when detaching. | |
1442 | Otherwise pass any pending signal the LWP may have, if any. */ | |
1443 | ||
1444 | static void | |
1445 | detach_one_lwp (struct lwp_info *lp, int *signo_p) | |
1446 | { | |
1447 | int lwpid = lp->ptid.lwp (); | |
1448 | int signo; | |
1449 | ||
1450 | /* If the lwp/thread we are about to detach has a pending fork/clone | |
1451 | event, there is a process/thread GDB is attached to that the core | |
1452 | of GDB doesn't know about. Detach from it. */ | |
1453 | ||
6b09f134 | 1454 | std::optional<target_waitstatus> ws = get_pending_child_status (lp); |
0d36baa9 PA |
1455 | if (ws.has_value ()) |
1456 | detach_one_pid (ws->child_ptid ().lwp (), 0); | |
d6b0e80f | 1457 | |
a0ef4274 DJ |
1458 | /* If there is a pending SIGSTOP, get rid of it. */ |
1459 | if (lp->signalled) | |
d6b0e80f | 1460 | { |
9327494e | 1461 | linux_nat_debug_printf ("Sending SIGCONT to %s", |
e53c95d4 | 1462 | lp->ptid.to_string ().c_str ()); |
d6b0e80f | 1463 | |
ced2dffb | 1464 | kill_lwp (lwpid, SIGCONT); |
d6b0e80f | 1465 | lp->signalled = 0; |
d6b0e80f AC |
1466 | } |
1467 | ||
57e6a098 KB |
1468 | /* If the lwp has exited or was terminated due to a signal, there's |
1469 | nothing left to do. */ | |
1470 | if (lp->waitstatus.kind () == TARGET_WAITKIND_EXITED | |
1471 | || lp->waitstatus.kind () == TARGET_WAITKIND_THREAD_EXITED | |
1472 | || lp->waitstatus.kind () == TARGET_WAITKIND_SIGNALLED) | |
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 | ||
d6b0e80f AC |
2202 | /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has |
2203 | exited. */ | |
2204 | ||
2205 | static int | |
2206 | wait_lwp (struct lwp_info *lp) | |
2207 | { | |
2208 | pid_t pid; | |
432b4d03 | 2209 | int status = 0; |
d6b0e80f | 2210 | int thread_dead = 0; |
432b4d03 | 2211 | sigset_t prev_mask; |
d6b0e80f AC |
2212 | |
2213 | gdb_assert (!lp->stopped); | |
2214 | gdb_assert (lp->status == 0); | |
2215 | ||
432b4d03 JK |
2216 | /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
2217 | block_child_signals (&prev_mask); | |
2218 | ||
2219 | for (;;) | |
d6b0e80f | 2220 | { |
e38504b3 | 2221 | pid = my_waitpid (lp->ptid.lwp (), &status, __WALL | WNOHANG); |
a9f4bb21 PA |
2222 | if (pid == -1 && errno == ECHILD) |
2223 | { | |
2224 | /* The thread has previously exited. We need to delete it | |
4a6ed09b PA |
2225 | now because if this was a non-leader thread execing, we |
2226 | won't get an exit event. See comments on exec events at | |
2227 | the top of the file. */ | |
a9f4bb21 | 2228 | thread_dead = 1; |
9327494e | 2229 | linux_nat_debug_printf ("%s vanished.", |
e53c95d4 | 2230 | lp->ptid.to_string ().c_str ()); |
a9f4bb21 | 2231 | } |
432b4d03 JK |
2232 | if (pid != 0) |
2233 | break; | |
2234 | ||
2235 | /* Bugs 10970, 12702. | |
2236 | Thread group leader may have exited in which case we'll lock up in | |
2237 | waitpid if there are other threads, even if they are all zombies too. | |
2238 | Basically, we're not supposed to use waitpid this way. | |
4a6ed09b PA |
2239 | tkill(pid,0) cannot be used here as it gets ESRCH for both |
2240 | for zombie and running processes. | |
432b4d03 JK |
2241 | |
2242 | As a workaround, check if we're waiting for the thread group leader and | |
2243 | if it's a zombie, and avoid calling waitpid if it is. | |
2244 | ||
2245 | This is racy, what if the tgl becomes a zombie right after we check? | |
2246 | Therefore always use WNOHANG with sigsuspend - it is equivalent to | |
5f572dec | 2247 | waiting waitpid but linux_proc_pid_is_zombie is safe this way. */ |
432b4d03 | 2248 | |
e38504b3 TT |
2249 | if (lp->ptid.pid () == lp->ptid.lwp () |
2250 | && linux_proc_pid_is_zombie (lp->ptid.lwp ())) | |
d6b0e80f | 2251 | { |
d6b0e80f | 2252 | thread_dead = 1; |
9327494e | 2253 | linux_nat_debug_printf ("Thread group leader %s vanished.", |
e53c95d4 | 2254 | lp->ptid.to_string ().c_str ()); |
432b4d03 | 2255 | break; |
d6b0e80f | 2256 | } |
432b4d03 JK |
2257 | |
2258 | /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers | |
2259 | get invoked despite our caller had them intentionally blocked by | |
2260 | block_child_signals. This is sensitive only to the loop of | |
2261 | linux_nat_wait_1 and there if we get called my_waitpid gets called | |
2262 | again before it gets to sigsuspend so we can safely let the handlers | |
2263 | get executed here. */ | |
9c3a5d93 | 2264 | wait_for_signal (); |
432b4d03 JK |
2265 | } |
2266 | ||
2267 | restore_child_signals_mask (&prev_mask); | |
2268 | ||
d6b0e80f AC |
2269 | if (!thread_dead) |
2270 | { | |
e38504b3 | 2271 | gdb_assert (pid == lp->ptid.lwp ()); |
d6b0e80f | 2272 | |
9327494e | 2273 | linux_nat_debug_printf ("waitpid %s received %s", |
e53c95d4 | 2274 | lp->ptid.to_string ().c_str (), |
8d06918f | 2275 | status_to_str (status).c_str ()); |
d6b0e80f | 2276 | |
a9f4bb21 PA |
2277 | /* Check if the thread has exited. */ |
2278 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
2279 | { | |
a51e14ef | 2280 | if (report_exit_events_for (lp) || is_leader (lp)) |
69dde7dc | 2281 | { |
9327494e | 2282 | linux_nat_debug_printf ("LWP %d exited.", lp->ptid.pid ()); |
69dde7dc | 2283 | |
aa01bd36 | 2284 | /* If this is the leader exiting, it means the whole |
69dde7dc | 2285 | process is gone. Store the status to report to the |
3d2d2172 PA |
2286 | core. */ |
2287 | mark_lwp_dead (lp, status); | |
69dde7dc PA |
2288 | return 0; |
2289 | } | |
2290 | ||
a9f4bb21 | 2291 | thread_dead = 1; |
9327494e | 2292 | linux_nat_debug_printf ("%s exited.", |
e53c95d4 | 2293 | lp->ptid.to_string ().c_str ()); |
a9f4bb21 | 2294 | } |
d6b0e80f AC |
2295 | } |
2296 | ||
2297 | if (thread_dead) | |
2298 | { | |
e26af52f | 2299 | exit_lwp (lp); |
d6b0e80f AC |
2300 | return 0; |
2301 | } | |
2302 | ||
2303 | gdb_assert (WIFSTOPPED (status)); | |
8817a6f2 | 2304 | lp->stopped = 1; |
d6b0e80f | 2305 | |
8784d563 PA |
2306 | if (lp->must_set_ptrace_flags) |
2307 | { | |
5b6d1e4f | 2308 | inferior *inf = find_inferior_pid (linux_target, lp->ptid.pid ()); |
de0d863e | 2309 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 2310 | |
e38504b3 | 2311 | linux_enable_event_reporting (lp->ptid.lwp (), options); |
8784d563 PA |
2312 | lp->must_set_ptrace_flags = 0; |
2313 | } | |
2314 | ||
ca2163eb PA |
2315 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2316 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2317 | { | |
2318 | /* No longer need the sysgood bit. The ptrace event ends up | |
2319 | recorded in lp->waitstatus if we care for it. We can carry | |
2320 | on handling the event like a regular SIGTRAP from here | |
2321 | on. */ | |
2322 | status = W_STOPCODE (SIGTRAP); | |
2323 | if (linux_handle_syscall_trap (lp, 1)) | |
2324 | return wait_lwp (lp); | |
2325 | } | |
bfd09d20 JS |
2326 | else |
2327 | { | |
2328 | /* Almost all other ptrace-stops are known to be outside of system | |
2329 | calls, with further exceptions in linux_handle_extended_wait. */ | |
2330 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2331 | } | |
ca2163eb | 2332 | |
d6b0e80f | 2333 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2334 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2335 | && linux_is_extended_waitstatus (status)) | |
d6b0e80f | 2336 | { |
9327494e | 2337 | linux_nat_debug_printf ("Handling extended status 0x%06x", status); |
4dd63d48 | 2338 | linux_handle_extended_wait (lp, status); |
20ba1ce6 | 2339 | return 0; |
d6b0e80f AC |
2340 | } |
2341 | ||
2342 | return status; | |
2343 | } | |
2344 | ||
2345 | /* Send a SIGSTOP to LP. */ | |
2346 | ||
2347 | static int | |
d3a70e03 | 2348 | stop_callback (struct lwp_info *lp) |
d6b0e80f AC |
2349 | { |
2350 | if (!lp->stopped && !lp->signalled) | |
2351 | { | |
2352 | int ret; | |
2353 | ||
9327494e | 2354 | linux_nat_debug_printf ("kill %s **<SIGSTOP>**", |
e53c95d4 | 2355 | lp->ptid.to_string ().c_str ()); |
9327494e | 2356 | |
d6b0e80f | 2357 | errno = 0; |
e38504b3 | 2358 | ret = kill_lwp (lp->ptid.lwp (), SIGSTOP); |
9327494e | 2359 | linux_nat_debug_printf ("lwp kill %d %s", ret, |
d6b0e80f | 2360 | errno ? safe_strerror (errno) : "ERRNO-OK"); |
d6b0e80f AC |
2361 | |
2362 | lp->signalled = 1; | |
2363 | gdb_assert (lp->status == 0); | |
2364 | } | |
2365 | ||
2366 | return 0; | |
2367 | } | |
2368 | ||
7b50312a PA |
2369 | /* Request a stop on LWP. */ |
2370 | ||
2371 | void | |
2372 | linux_stop_lwp (struct lwp_info *lwp) | |
2373 | { | |
d3a70e03 | 2374 | stop_callback (lwp); |
7b50312a PA |
2375 | } |
2376 | ||
2db9a427 PA |
2377 | /* See linux-nat.h */ |
2378 | ||
2379 | void | |
2380 | linux_stop_and_wait_all_lwps (void) | |
2381 | { | |
2382 | /* Stop all LWP's ... */ | |
d3a70e03 | 2383 | iterate_over_lwps (minus_one_ptid, stop_callback); |
2db9a427 PA |
2384 | |
2385 | /* ... and wait until all of them have reported back that | |
2386 | they're no longer running. */ | |
d3a70e03 | 2387 | iterate_over_lwps (minus_one_ptid, stop_wait_callback); |
2db9a427 PA |
2388 | } |
2389 | ||
2390 | /* See linux-nat.h */ | |
2391 | ||
2392 | void | |
2393 | linux_unstop_all_lwps (void) | |
2394 | { | |
2395 | iterate_over_lwps (minus_one_ptid, | |
d3a70e03 TT |
2396 | [] (struct lwp_info *info) |
2397 | { | |
2398 | return resume_stopped_resumed_lwps (info, minus_one_ptid); | |
2399 | }); | |
2db9a427 PA |
2400 | } |
2401 | ||
57380f4e | 2402 | /* Return non-zero if LWP PID has a pending SIGINT. */ |
d6b0e80f AC |
2403 | |
2404 | static int | |
57380f4e DJ |
2405 | linux_nat_has_pending_sigint (int pid) |
2406 | { | |
2407 | sigset_t pending, blocked, ignored; | |
57380f4e DJ |
2408 | |
2409 | linux_proc_pending_signals (pid, &pending, &blocked, &ignored); | |
2410 | ||
2411 | if (sigismember (&pending, SIGINT) | |
2412 | && !sigismember (&ignored, SIGINT)) | |
2413 | return 1; | |
2414 | ||
2415 | return 0; | |
2416 | } | |
2417 | ||
2418 | /* Set a flag in LP indicating that we should ignore its next SIGINT. */ | |
2419 | ||
2420 | static int | |
d3a70e03 | 2421 | set_ignore_sigint (struct lwp_info *lp) |
d6b0e80f | 2422 | { |
57380f4e DJ |
2423 | /* If a thread has a pending SIGINT, consume it; otherwise, set a |
2424 | flag to consume the next one. */ | |
2425 | if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) | |
2426 | && WSTOPSIG (lp->status) == SIGINT) | |
2427 | lp->status = 0; | |
2428 | else | |
2429 | lp->ignore_sigint = 1; | |
2430 | ||
2431 | return 0; | |
2432 | } | |
2433 | ||
2434 | /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. | |
2435 | This function is called after we know the LWP has stopped; if the LWP | |
2436 | stopped before the expected SIGINT was delivered, then it will never have | |
2437 | arrived. Also, if the signal was delivered to a shared queue and consumed | |
2438 | by a different thread, it will never be delivered to this LWP. */ | |
d6b0e80f | 2439 | |
57380f4e DJ |
2440 | static void |
2441 | maybe_clear_ignore_sigint (struct lwp_info *lp) | |
2442 | { | |
2443 | if (!lp->ignore_sigint) | |
2444 | return; | |
2445 | ||
e38504b3 | 2446 | if (!linux_nat_has_pending_sigint (lp->ptid.lwp ())) |
57380f4e | 2447 | { |
9327494e | 2448 | linux_nat_debug_printf ("Clearing bogus flag for %s", |
e53c95d4 | 2449 | lp->ptid.to_string ().c_str ()); |
57380f4e DJ |
2450 | lp->ignore_sigint = 0; |
2451 | } | |
2452 | } | |
2453 | ||
ebec9a0f PA |
2454 | /* Fetch the possible triggered data watchpoint info and store it in |
2455 | LP. | |
2456 | ||
2457 | On some archs, like x86, that use debug registers to set | |
2458 | watchpoints, it's possible that the way to know which watched | |
2459 | address trapped, is to check the register that is used to select | |
2460 | which address to watch. Problem is, between setting the watchpoint | |
2461 | and reading back which data address trapped, the user may change | |
2462 | the set of watchpoints, and, as a consequence, GDB changes the | |
2463 | debug registers in the inferior. To avoid reading back a stale | |
2464 | stopped-data-address when that happens, we cache in LP the fact | |
2465 | that a watchpoint trapped, and the corresponding data address, as | |
2466 | soon as we see LP stop with a SIGTRAP. If GDB changes the debug | |
2467 | registers meanwhile, we have the cached data we can rely on. */ | |
2468 | ||
9c02b525 PA |
2469 | static int |
2470 | check_stopped_by_watchpoint (struct lwp_info *lp) | |
ebec9a0f | 2471 | { |
2989a365 | 2472 | scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); |
ebec9a0f PA |
2473 | inferior_ptid = lp->ptid; |
2474 | ||
f6ac5f3d | 2475 | if (linux_target->low_stopped_by_watchpoint ()) |
ebec9a0f | 2476 | { |
15c66dd6 | 2477 | lp->stop_reason = TARGET_STOPPED_BY_WATCHPOINT; |
f6ac5f3d PA |
2478 | lp->stopped_data_address_p |
2479 | = linux_target->low_stopped_data_address (&lp->stopped_data_address); | |
ebec9a0f PA |
2480 | } |
2481 | ||
15c66dd6 | 2482 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
9c02b525 PA |
2483 | } |
2484 | ||
9c02b525 | 2485 | /* Returns true if the LWP had stopped for a watchpoint. */ |
ebec9a0f | 2486 | |
57810aa7 | 2487 | bool |
f6ac5f3d | 2488 | linux_nat_target::stopped_by_watchpoint () |
ebec9a0f PA |
2489 | { |
2490 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2491 | ||
2492 | gdb_assert (lp != NULL); | |
2493 | ||
15c66dd6 | 2494 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
ebec9a0f PA |
2495 | } |
2496 | ||
57810aa7 | 2497 | bool |
f6ac5f3d | 2498 | linux_nat_target::stopped_data_address (CORE_ADDR *addr_p) |
ebec9a0f PA |
2499 | { |
2500 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2501 | ||
2502 | gdb_assert (lp != NULL); | |
2503 | ||
2504 | *addr_p = lp->stopped_data_address; | |
2505 | ||
2506 | return lp->stopped_data_address_p; | |
2507 | } | |
2508 | ||
26ab7092 JK |
2509 | /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
2510 | ||
135340af PA |
2511 | bool |
2512 | linux_nat_target::low_status_is_event (int status) | |
26ab7092 JK |
2513 | { |
2514 | return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; | |
2515 | } | |
2516 | ||
57380f4e DJ |
2517 | /* Wait until LP is stopped. */ |
2518 | ||
2519 | static int | |
d3a70e03 | 2520 | stop_wait_callback (struct lwp_info *lp) |
57380f4e | 2521 | { |
5b6d1e4f | 2522 | inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
6c95b8df PA |
2523 | |
2524 | /* If this is a vfork parent, bail out, it is not going to report | |
2525 | any SIGSTOP until the vfork is done with. */ | |
2526 | if (inf->vfork_child != NULL) | |
2527 | return 0; | |
2528 | ||
d6b0e80f AC |
2529 | if (!lp->stopped) |
2530 | { | |
2531 | int status; | |
2532 | ||
2533 | status = wait_lwp (lp); | |
2534 | if (status == 0) | |
2535 | return 0; | |
2536 | ||
57380f4e DJ |
2537 | if (lp->ignore_sigint && WIFSTOPPED (status) |
2538 | && WSTOPSIG (status) == SIGINT) | |
d6b0e80f | 2539 | { |
57380f4e | 2540 | lp->ignore_sigint = 0; |
d6b0e80f AC |
2541 | |
2542 | errno = 0; | |
e38504b3 | 2543 | ptrace (PTRACE_CONT, lp->ptid.lwp (), 0, 0); |
8817a6f2 | 2544 | lp->stopped = 0; |
9327494e SM |
2545 | linux_nat_debug_printf |
2546 | ("PTRACE_CONT %s, 0, 0 (%s) (discarding SIGINT)", | |
e53c95d4 | 2547 | lp->ptid.to_string ().c_str (), |
9327494e | 2548 | errno ? safe_strerror (errno) : "OK"); |
d6b0e80f | 2549 | |
d3a70e03 | 2550 | return stop_wait_callback (lp); |
d6b0e80f AC |
2551 | } |
2552 | ||
57380f4e DJ |
2553 | maybe_clear_ignore_sigint (lp); |
2554 | ||
d6b0e80f AC |
2555 | if (WSTOPSIG (status) != SIGSTOP) |
2556 | { | |
e5ef252a | 2557 | /* The thread was stopped with a signal other than SIGSTOP. */ |
7feb7d06 | 2558 | |
9327494e | 2559 | linux_nat_debug_printf ("Pending event %s in %s", |
8d06918f | 2560 | status_to_str ((int) status).c_str (), |
e53c95d4 | 2561 | lp->ptid.to_string ().c_str ()); |
e5ef252a PA |
2562 | |
2563 | /* Save the sigtrap event. */ | |
2564 | lp->status = status; | |
e5ef252a | 2565 | gdb_assert (lp->signalled); |
e7ad2f14 | 2566 | save_stop_reason (lp); |
d6b0e80f AC |
2567 | } |
2568 | else | |
2569 | { | |
7010835a | 2570 | /* We caught the SIGSTOP that we intended to catch. */ |
e5ef252a | 2571 | |
9327494e | 2572 | linux_nat_debug_printf ("Expected SIGSTOP caught for %s.", |
e53c95d4 | 2573 | lp->ptid.to_string ().c_str ()); |
e5ef252a | 2574 | |
d6b0e80f | 2575 | lp->signalled = 0; |
7010835a AB |
2576 | |
2577 | /* If we are waiting for this stop so we can report the thread | |
2578 | stopped then we need to record this status. Otherwise, we can | |
2579 | now discard this stop event. */ | |
2580 | if (lp->last_resume_kind == resume_stop) | |
2581 | { | |
2582 | lp->status = status; | |
2583 | save_stop_reason (lp); | |
2584 | } | |
d6b0e80f AC |
2585 | } |
2586 | } | |
2587 | ||
2588 | return 0; | |
2589 | } | |
2590 | ||
74387712 SM |
2591 | /* Get the inferior associated to LWP. Must be called with an LWP that has |
2592 | an associated inferior. Always return non-nullptr. */ | |
2593 | ||
2594 | static inferior * | |
2595 | lwp_inferior (const lwp_info *lwp) | |
2596 | { | |
2597 | inferior *inf = find_inferior_ptid (linux_target, lwp->ptid); | |
2598 | gdb_assert (inf != nullptr); | |
2599 | return inf; | |
2600 | } | |
2601 | ||
9c02b525 PA |
2602 | /* Return non-zero if LP has a wait status pending. Discard the |
2603 | pending event and resume the LWP if the event that originally | |
2604 | caused the stop became uninteresting. */ | |
d6b0e80f AC |
2605 | |
2606 | static int | |
d3a70e03 | 2607 | status_callback (struct lwp_info *lp) |
d6b0e80f AC |
2608 | { |
2609 | /* Only report a pending wait status if we pretend that this has | |
2610 | indeed been resumed. */ | |
ca2163eb PA |
2611 | if (!lp->resumed) |
2612 | return 0; | |
2613 | ||
eb54c8bf PA |
2614 | if (!lwp_status_pending_p (lp)) |
2615 | return 0; | |
2616 | ||
15c66dd6 PA |
2617 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
2618 | || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) | |
9c02b525 | 2619 | { |
5b6d1e4f | 2620 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
9c02b525 PA |
2621 | CORE_ADDR pc; |
2622 | int discard = 0; | |
2623 | ||
9c02b525 PA |
2624 | pc = regcache_read_pc (regcache); |
2625 | ||
2626 | if (pc != lp->stop_pc) | |
2627 | { | |
9327494e | 2628 | linux_nat_debug_printf ("PC of %s changed. was=%s, now=%s", |
e53c95d4 | 2629 | lp->ptid.to_string ().c_str (), |
99d9c3b9 SM |
2630 | paddress (current_inferior ()->arch (), |
2631 | lp->stop_pc), | |
2632 | paddress (current_inferior ()->arch (), pc)); | |
9c02b525 PA |
2633 | discard = 1; |
2634 | } | |
faf09f01 PA |
2635 | |
2636 | #if !USE_SIGTRAP_SIGINFO | |
74387712 | 2637 | else if (!breakpoint_inserted_here_p (lwp_inferior (lp)->aspace, pc)) |
9c02b525 | 2638 | { |
9327494e | 2639 | linux_nat_debug_printf ("previous breakpoint of %s, at %s gone", |
e53c95d4 | 2640 | lp->ptid.to_string ().c_str (), |
99d9c3b9 SM |
2641 | paddress (current_inferior ()->arch (), |
2642 | lp->stop_pc)); | |
9c02b525 PA |
2643 | |
2644 | discard = 1; | |
2645 | } | |
faf09f01 | 2646 | #endif |
9c02b525 PA |
2647 | |
2648 | if (discard) | |
2649 | { | |
9327494e | 2650 | linux_nat_debug_printf ("pending event of %s cancelled.", |
e53c95d4 | 2651 | lp->ptid.to_string ().c_str ()); |
9c02b525 PA |
2652 | |
2653 | lp->status = 0; | |
2654 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); | |
2655 | return 0; | |
2656 | } | |
9c02b525 PA |
2657 | } |
2658 | ||
eb54c8bf | 2659 | return 1; |
d6b0e80f AC |
2660 | } |
2661 | ||
d6b0e80f AC |
2662 | /* Count the LWP's that have had events. */ |
2663 | ||
2664 | static int | |
d3a70e03 | 2665 | count_events_callback (struct lwp_info *lp, int *count) |
d6b0e80f | 2666 | { |
d6b0e80f AC |
2667 | gdb_assert (count != NULL); |
2668 | ||
9c02b525 PA |
2669 | /* Select only resumed LWPs that have an event pending. */ |
2670 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2671 | (*count)++; |
2672 | ||
2673 | return 0; | |
2674 | } | |
2675 | ||
2676 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
2677 | ||
2678 | static int | |
d3a70e03 | 2679 | select_singlestep_lwp_callback (struct lwp_info *lp) |
d6b0e80f | 2680 | { |
25289eb2 PA |
2681 | if (lp->last_resume_kind == resume_step |
2682 | && lp->status != 0) | |
d6b0e80f AC |
2683 | return 1; |
2684 | else | |
2685 | return 0; | |
2686 | } | |
2687 | ||
8a99810d PA |
2688 | /* Returns true if LP has a status pending. */ |
2689 | ||
2690 | static int | |
2691 | lwp_status_pending_p (struct lwp_info *lp) | |
2692 | { | |
2693 | /* We check for lp->waitstatus in addition to lp->status, because we | |
2694 | can have pending process exits recorded in lp->status and | |
2695 | W_EXITCODE(0,0) happens to be 0. */ | |
183be222 | 2696 | return lp->status != 0 || lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE; |
8a99810d PA |
2697 | } |
2698 | ||
b90fc188 | 2699 | /* Select the Nth LWP that has had an event. */ |
d6b0e80f AC |
2700 | |
2701 | static int | |
d3a70e03 | 2702 | select_event_lwp_callback (struct lwp_info *lp, int *selector) |
d6b0e80f | 2703 | { |
d6b0e80f AC |
2704 | gdb_assert (selector != NULL); |
2705 | ||
9c02b525 PA |
2706 | /* Select only resumed LWPs that have an event pending. */ |
2707 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2708 | if ((*selector)-- == 0) |
2709 | return 1; | |
2710 | ||
2711 | return 0; | |
2712 | } | |
2713 | ||
e7ad2f14 PA |
2714 | /* Called when the LWP stopped for a signal/trap. If it stopped for a |
2715 | trap check what caused it (breakpoint, watchpoint, trace, etc.), | |
2716 | and save the result in the LWP's stop_reason field. If it stopped | |
2717 | for a breakpoint, decrement the PC if necessary on the lwp's | |
2718 | architecture. */ | |
9c02b525 | 2719 | |
e7ad2f14 PA |
2720 | static void |
2721 | save_stop_reason (struct lwp_info *lp) | |
710151dd | 2722 | { |
e7ad2f14 PA |
2723 | struct regcache *regcache; |
2724 | struct gdbarch *gdbarch; | |
515630c5 | 2725 | CORE_ADDR pc; |
9c02b525 | 2726 | CORE_ADDR sw_bp_pc; |
faf09f01 PA |
2727 | #if USE_SIGTRAP_SIGINFO |
2728 | siginfo_t siginfo; | |
2729 | #endif | |
9c02b525 | 2730 | |
e7ad2f14 PA |
2731 | gdb_assert (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON); |
2732 | gdb_assert (lp->status != 0); | |
2733 | ||
135340af | 2734 | if (!linux_target->low_status_is_event (lp->status)) |
e7ad2f14 PA |
2735 | return; |
2736 | ||
74387712 | 2737 | inferior *inf = lwp_inferior (lp); |
a9deee17 PA |
2738 | if (inf->starting_up) |
2739 | return; | |
2740 | ||
5b6d1e4f | 2741 | regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 2742 | gdbarch = regcache->arch (); |
e7ad2f14 | 2743 | |
9c02b525 | 2744 | pc = regcache_read_pc (regcache); |
527a273a | 2745 | sw_bp_pc = pc - gdbarch_decr_pc_after_break (gdbarch); |
515630c5 | 2746 | |
faf09f01 PA |
2747 | #if USE_SIGTRAP_SIGINFO |
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 | } | |
2790 | #else | |
9c02b525 | 2791 | if ((!lp->step || lp->stop_pc == sw_bp_pc) |
74387712 | 2792 | && software_breakpoint_inserted_here_p (inf->aspace, sw_bp_pc)) |
710151dd | 2793 | { |
9c02b525 PA |
2794 | /* The LWP was either continued, or stepped a software |
2795 | breakpoint instruction. */ | |
e7ad2f14 PA |
2796 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
2797 | } | |
2798 | ||
74387712 | 2799 | if (hardware_breakpoint_inserted_here_p (inf->aspace, pc)) |
e7ad2f14 PA |
2800 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; |
2801 | ||
2802 | if (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON) | |
2803 | check_stopped_by_watchpoint (lp); | |
2804 | #endif | |
2805 | ||
2806 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT) | |
2807 | { | |
9327494e | 2808 | linux_nat_debug_printf ("%s stopped by software breakpoint", |
e53c95d4 | 2809 | lp->ptid.to_string ().c_str ()); |
710151dd PA |
2810 | |
2811 | /* Back up the PC if necessary. */ | |
9c02b525 PA |
2812 | if (pc != sw_bp_pc) |
2813 | regcache_write_pc (regcache, sw_bp_pc); | |
515630c5 | 2814 | |
e7ad2f14 PA |
2815 | /* Update this so we record the correct stop PC below. */ |
2816 | pc = sw_bp_pc; | |
710151dd | 2817 | } |
e7ad2f14 | 2818 | else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) |
9c02b525 | 2819 | { |
9327494e | 2820 | linux_nat_debug_printf ("%s stopped by hardware breakpoint", |
e53c95d4 | 2821 | lp->ptid.to_string ().c_str ()); |
e7ad2f14 PA |
2822 | } |
2823 | else if (lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT) | |
2824 | { | |
9327494e | 2825 | linux_nat_debug_printf ("%s stopped by hardware watchpoint", |
e53c95d4 | 2826 | lp->ptid.to_string ().c_str ()); |
9c02b525 | 2827 | } |
d6b0e80f | 2828 | |
e7ad2f14 | 2829 | lp->stop_pc = pc; |
d6b0e80f AC |
2830 | } |
2831 | ||
faf09f01 PA |
2832 | |
2833 | /* Returns true if the LWP had stopped for a software breakpoint. */ | |
2834 | ||
57810aa7 | 2835 | bool |
f6ac5f3d | 2836 | linux_nat_target::stopped_by_sw_breakpoint () |
faf09f01 PA |
2837 | { |
2838 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2839 | ||
2840 | gdb_assert (lp != NULL); | |
2841 | ||
2842 | return lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2843 | } | |
2844 | ||
2845 | /* Implement the supports_stopped_by_sw_breakpoint method. */ | |
2846 | ||
57810aa7 | 2847 | bool |
f6ac5f3d | 2848 | linux_nat_target::supports_stopped_by_sw_breakpoint () |
faf09f01 PA |
2849 | { |
2850 | return USE_SIGTRAP_SIGINFO; | |
2851 | } | |
2852 | ||
2853 | /* Returns true if the LWP had stopped for a hardware | |
2854 | breakpoint/watchpoint. */ | |
2855 | ||
57810aa7 | 2856 | bool |
f6ac5f3d | 2857 | linux_nat_target::stopped_by_hw_breakpoint () |
faf09f01 PA |
2858 | { |
2859 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2860 | ||
2861 | gdb_assert (lp != NULL); | |
2862 | ||
2863 | return lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT; | |
2864 | } | |
2865 | ||
2866 | /* Implement the supports_stopped_by_hw_breakpoint method. */ | |
2867 | ||
57810aa7 | 2868 | bool |
f6ac5f3d | 2869 | linux_nat_target::supports_stopped_by_hw_breakpoint () |
faf09f01 PA |
2870 | { |
2871 | return USE_SIGTRAP_SIGINFO; | |
2872 | } | |
2873 | ||
d6b0e80f AC |
2874 | /* Select one LWP out of those that have events pending. */ |
2875 | ||
2876 | static void | |
d90e17a7 | 2877 | select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
d6b0e80f AC |
2878 | { |
2879 | int num_events = 0; | |
2880 | int random_selector; | |
9c02b525 | 2881 | struct lwp_info *event_lp = NULL; |
d6b0e80f | 2882 | |
ac264b3b | 2883 | /* Record the wait status for the original LWP. */ |
d6b0e80f AC |
2884 | (*orig_lp)->status = *status; |
2885 | ||
9c02b525 PA |
2886 | /* In all-stop, give preference to the LWP that is being |
2887 | single-stepped. There will be at most one, and it will be the | |
2888 | LWP that the core is most interested in. If we didn't do this, | |
2889 | then we'd have to handle pending step SIGTRAPs somehow in case | |
2890 | the core later continues the previously-stepped thread, as | |
2891 | otherwise we'd report the pending SIGTRAP then, and the core, not | |
2892 | having stepped the thread, wouldn't understand what the trap was | |
2893 | for, and therefore would report it to the user as a random | |
2894 | signal. */ | |
fbea99ea | 2895 | if (!target_is_non_stop_p ()) |
d6b0e80f | 2896 | { |
d3a70e03 | 2897 | event_lp = iterate_over_lwps (filter, select_singlestep_lwp_callback); |
9c02b525 PA |
2898 | if (event_lp != NULL) |
2899 | { | |
9327494e | 2900 | linux_nat_debug_printf ("Select single-step %s", |
e53c95d4 | 2901 | event_lp->ptid.to_string ().c_str ()); |
9c02b525 | 2902 | } |
d6b0e80f | 2903 | } |
9c02b525 PA |
2904 | |
2905 | if (event_lp == NULL) | |
d6b0e80f | 2906 | { |
9c02b525 | 2907 | /* Pick one at random, out of those which have had events. */ |
d6b0e80f | 2908 | |
9c02b525 | 2909 | /* First see how many events we have. */ |
d3a70e03 TT |
2910 | iterate_over_lwps (filter, |
2911 | [&] (struct lwp_info *info) | |
2912 | { | |
2913 | return count_events_callback (info, &num_events); | |
2914 | }); | |
8bf3b159 | 2915 | gdb_assert (num_events > 0); |
d6b0e80f | 2916 | |
9c02b525 PA |
2917 | /* Now randomly pick a LWP out of those that have had |
2918 | events. */ | |
d6b0e80f AC |
2919 | random_selector = (int) |
2920 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
2921 | ||
9327494e SM |
2922 | if (num_events > 1) |
2923 | linux_nat_debug_printf ("Found %d events, selecting #%d", | |
2924 | num_events, random_selector); | |
d6b0e80f | 2925 | |
d3a70e03 TT |
2926 | event_lp |
2927 | = (iterate_over_lwps | |
2928 | (filter, | |
2929 | [&] (struct lwp_info *info) | |
2930 | { | |
2931 | return select_event_lwp_callback (info, | |
2932 | &random_selector); | |
2933 | })); | |
d6b0e80f AC |
2934 | } |
2935 | ||
2936 | if (event_lp != NULL) | |
2937 | { | |
2938 | /* Switch the event LWP. */ | |
2939 | *orig_lp = event_lp; | |
2940 | *status = event_lp->status; | |
2941 | } | |
2942 | ||
2943 | /* Flush the wait status for the event LWP. */ | |
2944 | (*orig_lp)->status = 0; | |
2945 | } | |
2946 | ||
2947 | /* Return non-zero if LP has been resumed. */ | |
2948 | ||
2949 | static int | |
d3a70e03 | 2950 | resumed_callback (struct lwp_info *lp) |
d6b0e80f AC |
2951 | { |
2952 | return lp->resumed; | |
2953 | } | |
2954 | ||
02f3fc28 | 2955 | /* Check if we should go on and pass this event to common code. |
12d9289a | 2956 | |
897608ed SM |
2957 | If so, save the status to the lwp_info structure associated to LWPID. */ |
2958 | ||
2959 | static void | |
9c02b525 | 2960 | linux_nat_filter_event (int lwpid, int status) |
02f3fc28 PA |
2961 | { |
2962 | struct lwp_info *lp; | |
89a5711c | 2963 | int event = linux_ptrace_get_extended_event (status); |
02f3fc28 | 2964 | |
f2907e49 | 2965 | lp = find_lwp_pid (ptid_t (lwpid)); |
02f3fc28 | 2966 | |
1abeb1e9 PA |
2967 | /* Check for events reported by anything not in our LWP list. */ |
2968 | if (lp == nullptr) | |
0e5bf2a8 | 2969 | { |
1abeb1e9 PA |
2970 | if (WIFSTOPPED (status)) |
2971 | { | |
2972 | if (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC) | |
2973 | { | |
2974 | /* A non-leader thread exec'ed after we've seen the | |
2975 | leader zombie, and removed it from our lists (in | |
2976 | check_zombie_leaders). The non-leader thread changes | |
2977 | its tid to the tgid. */ | |
2978 | linux_nat_debug_printf | |
2979 | ("Re-adding thread group leader LWP %d after exec.", | |
2980 | lwpid); | |
0e5bf2a8 | 2981 | |
1abeb1e9 PA |
2982 | lp = add_lwp (ptid_t (lwpid, lwpid)); |
2983 | lp->stopped = 1; | |
2984 | lp->resumed = 1; | |
2985 | add_thread (linux_target, lp->ptid); | |
2986 | } | |
2987 | else | |
2988 | { | |
2989 | /* A process we are controlling has forked and the new | |
2990 | child's stop was reported to us by the kernel. Save | |
2991 | its PID and go back to waiting for the fork event to | |
2992 | be reported - the stopped process might be returned | |
2993 | from waitpid before or after the fork event is. */ | |
2994 | linux_nat_debug_printf | |
2995 | ("Saving LWP %d status %s in stopped_pids list", | |
2996 | lwpid, status_to_str (status).c_str ()); | |
2997 | add_to_pid_list (&stopped_pids, lwpid, status); | |
2998 | } | |
2999 | } | |
3000 | else | |
3001 | { | |
3002 | /* Don't report an event for the exit of an LWP not in our | |
3003 | list, i.e. not part of any inferior we're debugging. | |
3004 | This can happen if we detach from a program we originally | |
6cf20c46 PA |
3005 | forked and then it exits. However, note that we may have |
3006 | earlier deleted a leader of an inferior we're debugging, | |
3007 | in check_zombie_leaders. Re-add it back here if so. */ | |
3008 | for (inferior *inf : all_inferiors (linux_target)) | |
3009 | { | |
3010 | if (inf->pid == lwpid) | |
3011 | { | |
3012 | linux_nat_debug_printf | |
3013 | ("Re-adding thread group leader LWP %d after exit.", | |
3014 | lwpid); | |
3015 | ||
3016 | lp = add_lwp (ptid_t (lwpid, lwpid)); | |
3017 | lp->resumed = 1; | |
3018 | add_thread (linux_target, lp->ptid); | |
3019 | break; | |
3020 | } | |
3021 | } | |
1abeb1e9 | 3022 | } |
0e5bf2a8 | 3023 | |
1abeb1e9 PA |
3024 | if (lp == nullptr) |
3025 | return; | |
02f3fc28 PA |
3026 | } |
3027 | ||
8817a6f2 PA |
3028 | /* This LWP is stopped now. (And if dead, this prevents it from |
3029 | ever being continued.) */ | |
3030 | lp->stopped = 1; | |
3031 | ||
8784d563 PA |
3032 | if (WIFSTOPPED (status) && lp->must_set_ptrace_flags) |
3033 | { | |
5b6d1e4f | 3034 | inferior *inf = find_inferior_pid (linux_target, lp->ptid.pid ()); |
de0d863e | 3035 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 3036 | |
e38504b3 | 3037 | linux_enable_event_reporting (lp->ptid.lwp (), options); |
8784d563 PA |
3038 | lp->must_set_ptrace_flags = 0; |
3039 | } | |
3040 | ||
ca2163eb PA |
3041 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
3042 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
3043 | { | |
3044 | /* No longer need the sysgood bit. The ptrace event ends up | |
3045 | recorded in lp->waitstatus if we care for it. We can carry | |
3046 | on handling the event like a regular SIGTRAP from here | |
3047 | on. */ | |
3048 | status = W_STOPCODE (SIGTRAP); | |
3049 | if (linux_handle_syscall_trap (lp, 0)) | |
897608ed | 3050 | return; |
ca2163eb | 3051 | } |
bfd09d20 JS |
3052 | else |
3053 | { | |
3054 | /* Almost all other ptrace-stops are known to be outside of system | |
3055 | calls, with further exceptions in linux_handle_extended_wait. */ | |
3056 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
3057 | } | |
02f3fc28 | 3058 | |
ca2163eb | 3059 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
3060 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
3061 | && linux_is_extended_waitstatus (status)) | |
02f3fc28 | 3062 | { |
9327494e SM |
3063 | linux_nat_debug_printf ("Handling extended status 0x%06x", status); |
3064 | ||
4dd63d48 | 3065 | if (linux_handle_extended_wait (lp, status)) |
897608ed | 3066 | return; |
02f3fc28 PA |
3067 | } |
3068 | ||
3069 | /* Check if the thread has exited. */ | |
9c02b525 PA |
3070 | if (WIFEXITED (status) || WIFSIGNALED (status)) |
3071 | { | |
a51e14ef | 3072 | if (!report_exit_events_for (lp) && !is_leader (lp)) |
02f3fc28 | 3073 | { |
9327494e | 3074 | linux_nat_debug_printf ("%s exited.", |
e53c95d4 | 3075 | lp->ptid.to_string ().c_str ()); |
9c02b525 | 3076 | |
6cf20c46 | 3077 | /* If this was not the leader exiting, then the exit signal |
4a6ed09b PA |
3078 | was not the end of the debugged application and should be |
3079 | ignored. */ | |
3080 | exit_lwp (lp); | |
897608ed | 3081 | return; |
02f3fc28 PA |
3082 | } |
3083 | ||
77598427 PA |
3084 | /* Note that even if the leader was ptrace-stopped, it can still |
3085 | exit, if e.g., some other thread brings down the whole | |
3086 | process (calls `exit'). So don't assert that the lwp is | |
3087 | resumed. */ | |
9327494e SM |
3088 | linux_nat_debug_printf ("LWP %ld exited (resumed=%d)", |
3089 | lp->ptid.lwp (), lp->resumed); | |
02f3fc28 | 3090 | |
3d2d2172 | 3091 | mark_lwp_dead (lp, status); |
897608ed | 3092 | return; |
02f3fc28 PA |
3093 | } |
3094 | ||
02f3fc28 PA |
3095 | /* Make sure we don't report a SIGSTOP that we sent ourselves in |
3096 | an attempt to stop an LWP. */ | |
3097 | if (lp->signalled | |
3098 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) | |
3099 | { | |
02f3fc28 PA |
3100 | lp->signalled = 0; |
3101 | ||
2bf6fb9d | 3102 | if (lp->last_resume_kind == resume_stop) |
25289eb2 | 3103 | { |
9327494e | 3104 | linux_nat_debug_printf ("resume_stop SIGSTOP caught for %s.", |
e53c95d4 | 3105 | lp->ptid.to_string ().c_str ()); |
2bf6fb9d PA |
3106 | } |
3107 | else | |
3108 | { | |
3109 | /* This is a delayed SIGSTOP. Filter out the event. */ | |
02f3fc28 | 3110 | |
9327494e SM |
3111 | linux_nat_debug_printf |
3112 | ("%s %s, 0, 0 (discard delayed SIGSTOP)", | |
3113 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 3114 | lp->ptid.to_string ().c_str ()); |
02f3fc28 | 3115 | |
2bf6fb9d | 3116 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
25289eb2 | 3117 | gdb_assert (lp->resumed); |
897608ed | 3118 | return; |
25289eb2 | 3119 | } |
02f3fc28 PA |
3120 | } |
3121 | ||
57380f4e DJ |
3122 | /* Make sure we don't report a SIGINT that we have already displayed |
3123 | for another thread. */ | |
3124 | if (lp->ignore_sigint | |
3125 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) | |
3126 | { | |
9327494e | 3127 | linux_nat_debug_printf ("Delayed SIGINT caught for %s.", |
e53c95d4 | 3128 | lp->ptid.to_string ().c_str ()); |
57380f4e DJ |
3129 | |
3130 | /* This is a delayed SIGINT. */ | |
3131 | lp->ignore_sigint = 0; | |
3132 | ||
8a99810d | 3133 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
9327494e SM |
3134 | linux_nat_debug_printf ("%s %s, 0, 0 (discard SIGINT)", |
3135 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 3136 | lp->ptid.to_string ().c_str ()); |
57380f4e DJ |
3137 | gdb_assert (lp->resumed); |
3138 | ||
3139 | /* Discard the event. */ | |
897608ed | 3140 | return; |
57380f4e DJ |
3141 | } |
3142 | ||
9c02b525 PA |
3143 | /* Don't report signals that GDB isn't interested in, such as |
3144 | signals that are neither printed nor stopped upon. Stopping all | |
7da6a5b9 | 3145 | threads can be a bit time-consuming, so if we want decent |
9c02b525 PA |
3146 | performance with heavily multi-threaded programs, especially when |
3147 | they're using a high frequency timer, we'd better avoid it if we | |
3148 | can. */ | |
3149 | if (WIFSTOPPED (status)) | |
3150 | { | |
3151 | enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status)); | |
3152 | ||
fbea99ea | 3153 | if (!target_is_non_stop_p ()) |
9c02b525 PA |
3154 | { |
3155 | /* Only do the below in all-stop, as we currently use SIGSTOP | |
3156 | to implement target_stop (see linux_nat_stop) in | |
3157 | non-stop. */ | |
3158 | if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0) | |
3159 | { | |
3160 | /* If ^C/BREAK is typed at the tty/console, SIGINT gets | |
3161 | forwarded to the entire process group, that is, all LWPs | |
3162 | will receive it - unless they're using CLONE_THREAD to | |
3163 | share signals. Since we only want to report it once, we | |
3164 | mark it as ignored for all LWPs except this one. */ | |
d3a70e03 | 3165 | iterate_over_lwps (ptid_t (lp->ptid.pid ()), set_ignore_sigint); |
9c02b525 PA |
3166 | lp->ignore_sigint = 0; |
3167 | } | |
3168 | else | |
3169 | maybe_clear_ignore_sigint (lp); | |
3170 | } | |
3171 | ||
3172 | /* When using hardware single-step, we need to report every signal. | |
c9587f88 | 3173 | Otherwise, signals in pass_mask may be short-circuited |
d8c06f22 AB |
3174 | except signals that might be caused by a breakpoint, or SIGSTOP |
3175 | if we sent the SIGSTOP and are waiting for it to arrive. */ | |
9c02b525 | 3176 | if (!lp->step |
c9587f88 | 3177 | && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status)) |
d8c06f22 | 3178 | && (WSTOPSIG (status) != SIGSTOP |
9213a6d7 | 3179 | || !linux_target->find_thread (lp->ptid)->stop_requested) |
c9587f88 | 3180 | && !linux_wstatus_maybe_breakpoint (status)) |
9c02b525 PA |
3181 | { |
3182 | linux_resume_one_lwp (lp, lp->step, signo); | |
9327494e SM |
3183 | linux_nat_debug_printf |
3184 | ("%s %s, %s (preempt 'handle')", | |
3185 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 3186 | lp->ptid.to_string ().c_str (), |
9327494e SM |
3187 | (signo != GDB_SIGNAL_0 |
3188 | ? strsignal (gdb_signal_to_host (signo)) : "0")); | |
897608ed | 3189 | return; |
9c02b525 PA |
3190 | } |
3191 | } | |
3192 | ||
02f3fc28 PA |
3193 | /* An interesting event. */ |
3194 | gdb_assert (lp); | |
ca2163eb | 3195 | lp->status = status; |
e7ad2f14 | 3196 | save_stop_reason (lp); |
02f3fc28 PA |
3197 | } |
3198 | ||
0e5bf2a8 PA |
3199 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
3200 | their exits until all other threads in the group have exited. */ | |
3201 | ||
3202 | static void | |
3203 | check_zombie_leaders (void) | |
3204 | { | |
08036331 | 3205 | for (inferior *inf : all_inferiors ()) |
0e5bf2a8 PA |
3206 | { |
3207 | struct lwp_info *leader_lp; | |
3208 | ||
3209 | if (inf->pid == 0) | |
3210 | continue; | |
3211 | ||
f2907e49 | 3212 | leader_lp = find_lwp_pid (ptid_t (inf->pid)); |
0e5bf2a8 PA |
3213 | if (leader_lp != NULL |
3214 | /* Check if there are other threads in the group, as we may | |
6cf20c46 PA |
3215 | have raced with the inferior simply exiting. Note this |
3216 | isn't a watertight check. If the inferior is | |
3217 | multi-threaded and is exiting, it may be we see the | |
3218 | leader as zombie before we reap all the non-leader | |
3219 | threads. See comments below. */ | |
0e5bf2a8 | 3220 | && num_lwps (inf->pid) > 1 |
5f572dec | 3221 | && linux_proc_pid_is_zombie (inf->pid)) |
0e5bf2a8 | 3222 | { |
6cf20c46 PA |
3223 | /* A zombie leader in a multi-threaded program can mean one |
3224 | of three things: | |
3225 | ||
3226 | #1 - Only the leader exited, not the whole program, e.g., | |
3227 | with pthread_exit. Since we can't reap the leader's exit | |
3228 | status until all other threads are gone and reaped too, | |
3229 | we want to delete the zombie leader right away, as it | |
3230 | can't be debugged, we can't read its registers, etc. | |
3231 | This is the main reason we check for zombie leaders | |
3232 | disappearing. | |
3233 | ||
3234 | #2 - The whole thread-group/process exited (a group exit, | |
3235 | via e.g. exit(3), and there is (or will be shortly) an | |
3236 | exit reported for each thread in the process, and then | |
3237 | finally an exit for the leader once the non-leaders are | |
3238 | reaped. | |
3239 | ||
3240 | #3 - There are 3 or more threads in the group, and a | |
3241 | thread other than the leader exec'd. See comments on | |
3242 | exec events at the top of the file. | |
3243 | ||
3244 | Ideally we would never delete the leader for case #2. | |
3245 | Instead, we want to collect the exit status of each | |
3246 | non-leader thread, and then finally collect the exit | |
3247 | status of the leader as normal and use its exit code as | |
3248 | whole-process exit code. Unfortunately, there's no | |
3249 | race-free way to distinguish cases #1 and #2. We can't | |
3250 | assume the exit events for the non-leaders threads are | |
3251 | already pending in the kernel, nor can we assume the | |
3252 | non-leader threads are in zombie state already. Between | |
3253 | the leader becoming zombie and the non-leaders exiting | |
3254 | and becoming zombie themselves, there's a small time | |
3255 | window, so such a check would be racy. Temporarily | |
3256 | pausing all threads and checking to see if all threads | |
3257 | exit or not before re-resuming them would work in the | |
3258 | case that all threads are running right now, but it | |
3259 | wouldn't work if some thread is currently already | |
3260 | ptrace-stopped, e.g., due to scheduler-locking. | |
3261 | ||
3262 | So what we do is we delete the leader anyhow, and then | |
3263 | later on when we see its exit status, we re-add it back. | |
3264 | We also make sure that we only report a whole-process | |
3265 | exit when we see the leader exiting, as opposed to when | |
3266 | the last LWP in the LWP list exits, which can be a | |
3267 | non-leader if we deleted the leader here. */ | |
9327494e | 3268 | linux_nat_debug_printf ("Thread group leader %d zombie " |
6cf20c46 PA |
3269 | "(it exited, or another thread execd), " |
3270 | "deleting it.", | |
9327494e | 3271 | inf->pid); |
0e5bf2a8 PA |
3272 | exit_lwp (leader_lp); |
3273 | } | |
3274 | } | |
3275 | } | |
3276 | ||
a51e14ef PA |
3277 | /* Convenience function that is called when we're about to return an |
3278 | event to the core. If the event is an exit or signalled event, | |
3279 | then this decides whether to report it as process-wide event, as a | |
3280 | thread exit event, or to suppress it. All other event kinds are | |
3281 | passed through unmodified. */ | |
aa01bd36 PA |
3282 | |
3283 | static ptid_t | |
3284 | filter_exit_event (struct lwp_info *event_child, | |
3285 | struct target_waitstatus *ourstatus) | |
3286 | { | |
3287 | ptid_t ptid = event_child->ptid; | |
3288 | ||
a51e14ef PA |
3289 | /* Note we must filter TARGET_WAITKIND_SIGNALLED as well, otherwise |
3290 | if a non-leader thread exits with a signal, we'd report it to the | |
3291 | core which would interpret it as the whole-process exiting. | |
3292 | There is no TARGET_WAITKIND_THREAD_SIGNALLED event kind. */ | |
3293 | if (ourstatus->kind () != TARGET_WAITKIND_EXITED | |
3294 | && ourstatus->kind () != TARGET_WAITKIND_SIGNALLED) | |
3295 | return ptid; | |
3296 | ||
6cf20c46 | 3297 | if (!is_leader (event_child)) |
aa01bd36 | 3298 | { |
a51e14ef | 3299 | if (report_exit_events_for (event_child)) |
7730e5c6 PA |
3300 | { |
3301 | ourstatus->set_thread_exited (0); | |
3302 | /* Delete lwp, but not thread_info, infrun will need it to | |
3303 | process the event. */ | |
3304 | exit_lwp (event_child, false); | |
3305 | } | |
aa01bd36 | 3306 | else |
7730e5c6 PA |
3307 | { |
3308 | ourstatus->set_ignore (); | |
3309 | exit_lwp (event_child); | |
3310 | } | |
aa01bd36 PA |
3311 | } |
3312 | ||
3313 | return ptid; | |
3314 | } | |
3315 | ||
d6b0e80f | 3316 | static ptid_t |
f6ac5f3d | 3317 | linux_nat_wait_1 (ptid_t ptid, struct target_waitstatus *ourstatus, |
b60cea74 | 3318 | target_wait_flags target_options) |
d6b0e80f | 3319 | { |
b26b06dd AB |
3320 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
3321 | ||
fc9b8e47 | 3322 | sigset_t prev_mask; |
4b60df3d | 3323 | enum resume_kind last_resume_kind; |
12d9289a | 3324 | struct lwp_info *lp; |
12d9289a | 3325 | int status; |
d6b0e80f | 3326 | |
f973ed9c DJ |
3327 | /* The first time we get here after starting a new inferior, we may |
3328 | not have added it to the LWP list yet - this is the earliest | |
3329 | moment at which we know its PID. */ | |
677c92fe | 3330 | if (ptid.is_pid () && find_lwp_pid (ptid) == nullptr) |
f973ed9c | 3331 | { |
677c92fe | 3332 | ptid_t lwp_ptid (ptid.pid (), ptid.pid ()); |
27c9d204 | 3333 | |
677c92fe SM |
3334 | /* Upgrade the main thread's ptid. */ |
3335 | thread_change_ptid (linux_target, ptid, lwp_ptid); | |
3336 | lp = add_initial_lwp (lwp_ptid); | |
f973ed9c DJ |
3337 | lp->resumed = 1; |
3338 | } | |
3339 | ||
12696c10 | 3340 | /* Make sure SIGCHLD is blocked until the sigsuspend below. */ |
7feb7d06 | 3341 | block_child_signals (&prev_mask); |
d6b0e80f | 3342 | |
d6b0e80f | 3343 | /* First check if there is a LWP with a wait status pending. */ |
d3a70e03 | 3344 | lp = iterate_over_lwps (ptid, status_callback); |
8a99810d | 3345 | if (lp != NULL) |
d6b0e80f | 3346 | { |
9327494e | 3347 | linux_nat_debug_printf ("Using pending wait status %s for %s.", |
57573e54 | 3348 | pending_status_str (lp).c_str (), |
e53c95d4 | 3349 | lp->ptid.to_string ().c_str ()); |
d6b0e80f AC |
3350 | } |
3351 | ||
9c02b525 PA |
3352 | /* But if we don't find a pending event, we'll have to wait. Always |
3353 | pull all events out of the kernel. We'll randomly select an | |
3354 | event LWP out of all that have events, to prevent starvation. */ | |
7feb7d06 | 3355 | |
d90e17a7 | 3356 | while (lp == NULL) |
d6b0e80f AC |
3357 | { |
3358 | pid_t lwpid; | |
3359 | ||
0e5bf2a8 PA |
3360 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
3361 | quirks: | |
3362 | ||
3363 | - If the thread group leader exits while other threads in the | |
3364 | thread group still exist, waitpid(TGID, ...) hangs. That | |
3365 | waitpid won't return an exit status until the other threads | |
85102364 | 3366 | in the group are reaped. |
0e5bf2a8 PA |
3367 | |
3368 | - When a non-leader thread execs, that thread just vanishes | |
3369 | without reporting an exit (so we'd hang if we waited for it | |
3370 | explicitly in that case). The exec event is reported to | |
3371 | the TGID pid. */ | |
3372 | ||
3373 | errno = 0; | |
4a6ed09b | 3374 | lwpid = my_waitpid (-1, &status, __WALL | WNOHANG); |
0e5bf2a8 | 3375 | |
9327494e SM |
3376 | linux_nat_debug_printf ("waitpid(-1, ...) returned %d, %s", |
3377 | lwpid, | |
3378 | errno ? safe_strerror (errno) : "ERRNO-OK"); | |
b84876c2 | 3379 | |
d6b0e80f AC |
3380 | if (lwpid > 0) |
3381 | { | |
9327494e | 3382 | linux_nat_debug_printf ("waitpid %ld received %s", |
8d06918f SM |
3383 | (long) lwpid, |
3384 | status_to_str (status).c_str ()); | |
d6b0e80f | 3385 | |
9c02b525 | 3386 | linux_nat_filter_event (lwpid, status); |
0e5bf2a8 PA |
3387 | /* Retry until nothing comes out of waitpid. A single |
3388 | SIGCHLD can indicate more than one child stopped. */ | |
3389 | continue; | |
d6b0e80f AC |
3390 | } |
3391 | ||
20ba1ce6 PA |
3392 | /* Now that we've pulled all events out of the kernel, resume |
3393 | LWPs that don't have an interesting event to report. */ | |
3394 | iterate_over_lwps (minus_one_ptid, | |
d3a70e03 TT |
3395 | [] (struct lwp_info *info) |
3396 | { | |
3397 | return resume_stopped_resumed_lwps (info, minus_one_ptid); | |
3398 | }); | |
20ba1ce6 PA |
3399 | |
3400 | /* ... and find an LWP with a status to report to the core, if | |
3401 | any. */ | |
d3a70e03 | 3402 | lp = iterate_over_lwps (ptid, status_callback); |
9c02b525 PA |
3403 | if (lp != NULL) |
3404 | break; | |
3405 | ||
0e5bf2a8 PA |
3406 | /* Check for zombie thread group leaders. Those can't be reaped |
3407 | until all other threads in the thread group are. */ | |
3408 | check_zombie_leaders (); | |
d6b0e80f | 3409 | |
0e5bf2a8 PA |
3410 | /* If there are no resumed children left, bail. We'd be stuck |
3411 | forever in the sigsuspend call below otherwise. */ | |
d3a70e03 | 3412 | if (iterate_over_lwps (ptid, resumed_callback) == NULL) |
0e5bf2a8 | 3413 | { |
9327494e | 3414 | linux_nat_debug_printf ("exit (no resumed LWP)"); |
b84876c2 | 3415 | |
183be222 | 3416 | ourstatus->set_no_resumed (); |
b84876c2 | 3417 | |
0e5bf2a8 PA |
3418 | restore_child_signals_mask (&prev_mask); |
3419 | return minus_one_ptid; | |
d6b0e80f | 3420 | } |
28736962 | 3421 | |
0e5bf2a8 PA |
3422 | /* No interesting event to report to the core. */ |
3423 | ||
3424 | if (target_options & TARGET_WNOHANG) | |
3425 | { | |
b26b06dd | 3426 | linux_nat_debug_printf ("no interesting events found"); |
28736962 | 3427 | |
183be222 | 3428 | ourstatus->set_ignore (); |
28736962 PA |
3429 | restore_child_signals_mask (&prev_mask); |
3430 | return minus_one_ptid; | |
3431 | } | |
d6b0e80f AC |
3432 | |
3433 | /* We shouldn't end up here unless we want to try again. */ | |
d90e17a7 | 3434 | gdb_assert (lp == NULL); |
0e5bf2a8 PA |
3435 | |
3436 | /* Block until we get an event reported with SIGCHLD. */ | |
9c3a5d93 | 3437 | wait_for_signal (); |
d6b0e80f AC |
3438 | } |
3439 | ||
d6b0e80f | 3440 | gdb_assert (lp); |
3d2d2172 | 3441 | gdb_assert (lp->stopped); |
d6b0e80f | 3442 | |
ca2163eb PA |
3443 | status = lp->status; |
3444 | lp->status = 0; | |
3445 | ||
fbea99ea | 3446 | if (!target_is_non_stop_p ()) |
4c28f408 PA |
3447 | { |
3448 | /* Now stop all other LWP's ... */ | |
d3a70e03 | 3449 | iterate_over_lwps (minus_one_ptid, stop_callback); |
4c28f408 PA |
3450 | |
3451 | /* ... and wait until all of them have reported back that | |
3452 | they're no longer running. */ | |
d3a70e03 | 3453 | iterate_over_lwps (minus_one_ptid, stop_wait_callback); |
9c02b525 PA |
3454 | } |
3455 | ||
3456 | /* If we're not waiting for a specific LWP, choose an event LWP from | |
3457 | among those that have had events. Giving equal priority to all | |
3458 | LWPs that have had events helps prevent starvation. */ | |
d7e15655 | 3459 | if (ptid == minus_one_ptid || ptid.is_pid ()) |
9c02b525 PA |
3460 | select_event_lwp (ptid, &lp, &status); |
3461 | ||
3462 | gdb_assert (lp != NULL); | |
3463 | ||
3464 | /* Now that we've selected our final event LWP, un-adjust its PC if | |
faf09f01 PA |
3465 | it was a software breakpoint, and we can't reliably support the |
3466 | "stopped by software breakpoint" stop reason. */ | |
3467 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT | |
3468 | && !USE_SIGTRAP_SIGINFO) | |
9c02b525 | 3469 | { |
5b6d1e4f | 3470 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 3471 | struct gdbarch *gdbarch = regcache->arch (); |
527a273a | 3472 | int decr_pc = gdbarch_decr_pc_after_break (gdbarch); |
4c28f408 | 3473 | |
9c02b525 PA |
3474 | if (decr_pc != 0) |
3475 | { | |
3476 | CORE_ADDR pc; | |
d6b0e80f | 3477 | |
9c02b525 PA |
3478 | pc = regcache_read_pc (regcache); |
3479 | regcache_write_pc (regcache, pc + decr_pc); | |
3480 | } | |
3481 | } | |
e3e9f5a2 | 3482 | |
9c02b525 PA |
3483 | /* We'll need this to determine whether to report a SIGSTOP as |
3484 | GDB_SIGNAL_0. Need to take a copy because resume_clear_callback | |
3485 | clears it. */ | |
3486 | last_resume_kind = lp->last_resume_kind; | |
4b60df3d | 3487 | |
fbea99ea | 3488 | if (!target_is_non_stop_p ()) |
9c02b525 | 3489 | { |
e3e9f5a2 PA |
3490 | /* In all-stop, from the core's perspective, all LWPs are now |
3491 | stopped until a new resume action is sent over. */ | |
d3a70e03 | 3492 | iterate_over_lwps (minus_one_ptid, resume_clear_callback); |
e3e9f5a2 PA |
3493 | } |
3494 | else | |
25289eb2 | 3495 | { |
d3a70e03 | 3496 | resume_clear_callback (lp); |
25289eb2 | 3497 | } |
d6b0e80f | 3498 | |
135340af | 3499 | if (linux_target->low_status_is_event (status)) |
d6b0e80f | 3500 | { |
9327494e | 3501 | linux_nat_debug_printf ("trap ptid is %s.", |
e53c95d4 | 3502 | lp->ptid.to_string ().c_str ()); |
d6b0e80f | 3503 | } |
d6b0e80f | 3504 | |
183be222 | 3505 | if (lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE) |
d6b0e80f AC |
3506 | { |
3507 | *ourstatus = lp->waitstatus; | |
183be222 | 3508 | lp->waitstatus.set_ignore (); |
d6b0e80f AC |
3509 | } |
3510 | else | |
7509b829 | 3511 | *ourstatus = host_status_to_waitstatus (status); |
d6b0e80f | 3512 | |
b26b06dd | 3513 | linux_nat_debug_printf ("event found"); |
b84876c2 | 3514 | |
7feb7d06 | 3515 | restore_child_signals_mask (&prev_mask); |
1e225492 | 3516 | |
4b60df3d | 3517 | if (last_resume_kind == resume_stop |
183be222 | 3518 | && ourstatus->kind () == TARGET_WAITKIND_STOPPED |
25289eb2 PA |
3519 | && WSTOPSIG (status) == SIGSTOP) |
3520 | { | |
3521 | /* A thread that has been requested to stop by GDB with | |
3522 | target_stop, and it stopped cleanly, so report as SIG0. The | |
3523 | use of SIGSTOP is an implementation detail. */ | |
183be222 | 3524 | ourstatus->set_stopped (GDB_SIGNAL_0); |
25289eb2 PA |
3525 | } |
3526 | ||
183be222 SM |
3527 | if (ourstatus->kind () == TARGET_WAITKIND_EXITED |
3528 | || ourstatus->kind () == TARGET_WAITKIND_SIGNALLED) | |
1e225492 JK |
3529 | lp->core = -1; |
3530 | else | |
2e794194 | 3531 | lp->core = linux_common_core_of_thread (lp->ptid); |
1e225492 | 3532 | |
a51e14ef | 3533 | return filter_exit_event (lp, ourstatus); |
d6b0e80f AC |
3534 | } |
3535 | ||
e3e9f5a2 PA |
3536 | /* Resume LWPs that are currently stopped without any pending status |
3537 | to report, but are resumed from the core's perspective. */ | |
3538 | ||
3539 | static int | |
d3a70e03 | 3540 | resume_stopped_resumed_lwps (struct lwp_info *lp, const ptid_t wait_ptid) |
e3e9f5a2 | 3541 | { |
74387712 | 3542 | inferior *inf = lwp_inferior (lp); |
14ec4172 | 3543 | |
8a9da63e | 3544 | if (!lp->stopped) |
4dd63d48 | 3545 | { |
9327494e | 3546 | linux_nat_debug_printf ("NOT resuming LWP %s, not stopped", |
e53c95d4 | 3547 | lp->ptid.to_string ().c_str ()); |
4dd63d48 PA |
3548 | } |
3549 | else if (!lp->resumed) | |
3550 | { | |
9327494e | 3551 | linux_nat_debug_printf ("NOT resuming LWP %s, not resumed", |
e53c95d4 | 3552 | lp->ptid.to_string ().c_str ()); |
4dd63d48 PA |
3553 | } |
3554 | else if (lwp_status_pending_p (lp)) | |
3555 | { | |
9327494e | 3556 | linux_nat_debug_printf ("NOT resuming LWP %s, has pending status", |
e53c95d4 | 3557 | lp->ptid.to_string ().c_str ()); |
4dd63d48 | 3558 | } |
8a9da63e AB |
3559 | else if (inf->vfork_child != nullptr) |
3560 | { | |
3561 | linux_nat_debug_printf ("NOT resuming LWP %s (vfork parent)", | |
3562 | lp->ptid.to_string ().c_str ()); | |
3563 | } | |
4dd63d48 | 3564 | else |
e3e9f5a2 | 3565 | { |
5b6d1e4f | 3566 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 3567 | struct gdbarch *gdbarch = regcache->arch (); |
336060f3 | 3568 | |
a70b8144 | 3569 | try |
e3e9f5a2 | 3570 | { |
23f238d3 PA |
3571 | CORE_ADDR pc = regcache_read_pc (regcache); |
3572 | int leave_stopped = 0; | |
e3e9f5a2 | 3573 | |
23f238d3 PA |
3574 | /* Don't bother if there's a breakpoint at PC that we'd hit |
3575 | immediately, and we're not waiting for this LWP. */ | |
d3a70e03 | 3576 | if (!lp->ptid.matches (wait_ptid)) |
23f238d3 | 3577 | { |
f9582a22 | 3578 | if (breakpoint_inserted_here_p (inf->aspace.get (), pc)) |
23f238d3 PA |
3579 | leave_stopped = 1; |
3580 | } | |
e3e9f5a2 | 3581 | |
23f238d3 PA |
3582 | if (!leave_stopped) |
3583 | { | |
9327494e SM |
3584 | linux_nat_debug_printf |
3585 | ("resuming stopped-resumed LWP %s at %s: step=%d", | |
e53c95d4 | 3586 | lp->ptid.to_string ().c_str (), paddress (gdbarch, pc), |
9327494e | 3587 | lp->step); |
23f238d3 PA |
3588 | |
3589 | linux_resume_one_lwp_throw (lp, lp->step, GDB_SIGNAL_0); | |
3590 | } | |
3591 | } | |
230d2906 | 3592 | catch (const gdb_exception_error &ex) |
23f238d3 PA |
3593 | { |
3594 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 3595 | throw; |
23f238d3 | 3596 | } |
e3e9f5a2 PA |
3597 | } |
3598 | ||
3599 | return 0; | |
3600 | } | |
3601 | ||
f6ac5f3d PA |
3602 | ptid_t |
3603 | linux_nat_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus, | |
b60cea74 | 3604 | target_wait_flags target_options) |
7feb7d06 | 3605 | { |
b26b06dd AB |
3606 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
3607 | ||
7feb7d06 PA |
3608 | ptid_t event_ptid; |
3609 | ||
e53c95d4 | 3610 | linux_nat_debug_printf ("[%s], [%s]", ptid.to_string ().c_str (), |
9327494e | 3611 | target_options_to_string (target_options).c_str ()); |
7feb7d06 PA |
3612 | |
3613 | /* Flush the async file first. */ | |
d9d41e78 | 3614 | if (target_is_async_p ()) |
7feb7d06 PA |
3615 | async_file_flush (); |
3616 | ||
e3e9f5a2 PA |
3617 | /* Resume LWPs that are currently stopped without any pending status |
3618 | to report, but are resumed from the core's perspective. LWPs get | |
3619 | in this state if we find them stopping at a time we're not | |
3620 | interested in reporting the event (target_wait on a | |
3621 | specific_process, for example, see linux_nat_wait_1), and | |
3622 | meanwhile the event became uninteresting. Don't bother resuming | |
3623 | LWPs we're not going to wait for if they'd stop immediately. */ | |
fbea99ea | 3624 | if (target_is_non_stop_p ()) |
d3a70e03 TT |
3625 | iterate_over_lwps (minus_one_ptid, |
3626 | [=] (struct lwp_info *info) | |
3627 | { | |
3628 | return resume_stopped_resumed_lwps (info, ptid); | |
3629 | }); | |
e3e9f5a2 | 3630 | |
f6ac5f3d | 3631 | event_ptid = linux_nat_wait_1 (ptid, ourstatus, target_options); |
7feb7d06 PA |
3632 | |
3633 | /* If we requested any event, and something came out, assume there | |
3634 | may be more. If we requested a specific lwp or process, also | |
3635 | assume there may be more. */ | |
d9d41e78 | 3636 | if (target_is_async_p () |
183be222 SM |
3637 | && ((ourstatus->kind () != TARGET_WAITKIND_IGNORE |
3638 | && ourstatus->kind () != TARGET_WAITKIND_NO_RESUMED) | |
d7e15655 | 3639 | || ptid != minus_one_ptid)) |
7feb7d06 PA |
3640 | async_file_mark (); |
3641 | ||
7feb7d06 PA |
3642 | return event_ptid; |
3643 | } | |
3644 | ||
1d2736d4 PA |
3645 | /* Kill one LWP. */ |
3646 | ||
3647 | static void | |
3648 | kill_one_lwp (pid_t pid) | |
d6b0e80f | 3649 | { |
ed731959 JK |
3650 | /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
3651 | ||
3652 | errno = 0; | |
1d2736d4 | 3653 | kill_lwp (pid, SIGKILL); |
9327494e | 3654 | |
ed731959 | 3655 | if (debug_linux_nat) |
57745c90 PA |
3656 | { |
3657 | int save_errno = errno; | |
3658 | ||
9327494e SM |
3659 | linux_nat_debug_printf |
3660 | ("kill (SIGKILL) %ld, 0, 0 (%s)", (long) pid, | |
3661 | save_errno != 0 ? safe_strerror (save_errno) : "OK"); | |
57745c90 | 3662 | } |
ed731959 JK |
3663 | |
3664 | /* Some kernels ignore even SIGKILL for processes under ptrace. */ | |
3665 | ||
d6b0e80f | 3666 | errno = 0; |
1d2736d4 | 3667 | ptrace (PTRACE_KILL, pid, 0, 0); |
d6b0e80f | 3668 | if (debug_linux_nat) |
57745c90 PA |
3669 | { |
3670 | int save_errno = errno; | |
3671 | ||
9327494e SM |
3672 | linux_nat_debug_printf |
3673 | ("PTRACE_KILL %ld, 0, 0 (%s)", (long) pid, | |
3674 | save_errno ? safe_strerror (save_errno) : "OK"); | |
57745c90 | 3675 | } |
d6b0e80f AC |
3676 | } |
3677 | ||
1d2736d4 PA |
3678 | /* Wait for an LWP to die. */ |
3679 | ||
3680 | static void | |
3681 | kill_wait_one_lwp (pid_t pid) | |
d6b0e80f | 3682 | { |
1d2736d4 | 3683 | pid_t res; |
d6b0e80f AC |
3684 | |
3685 | /* We must make sure that there are no pending events (delayed | |
3686 | SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current | |
3687 | program doesn't interfere with any following debugging session. */ | |
3688 | ||
d6b0e80f AC |
3689 | do |
3690 | { | |
1d2736d4 PA |
3691 | res = my_waitpid (pid, NULL, __WALL); |
3692 | if (res != (pid_t) -1) | |
d6b0e80f | 3693 | { |
9327494e SM |
3694 | linux_nat_debug_printf ("wait %ld received unknown.", (long) pid); |
3695 | ||
4a6ed09b PA |
3696 | /* The Linux kernel sometimes fails to kill a thread |
3697 | completely after PTRACE_KILL; that goes from the stop | |
3698 | point in do_fork out to the one in get_signal_to_deliver | |
3699 | and waits again. So kill it again. */ | |
1d2736d4 | 3700 | kill_one_lwp (pid); |
d6b0e80f AC |
3701 | } |
3702 | } | |
1d2736d4 PA |
3703 | while (res == pid); |
3704 | ||
3705 | gdb_assert (res == -1 && errno == ECHILD); | |
3706 | } | |
3707 | ||
3708 | /* Callback for iterate_over_lwps. */ | |
d6b0e80f | 3709 | |
1d2736d4 | 3710 | static int |
d3a70e03 | 3711 | kill_callback (struct lwp_info *lp) |
1d2736d4 | 3712 | { |
e38504b3 | 3713 | kill_one_lwp (lp->ptid.lwp ()); |
d6b0e80f AC |
3714 | return 0; |
3715 | } | |
3716 | ||
1d2736d4 PA |
3717 | /* Callback for iterate_over_lwps. */ |
3718 | ||
3719 | static int | |
d3a70e03 | 3720 | kill_wait_callback (struct lwp_info *lp) |
1d2736d4 | 3721 | { |
e38504b3 | 3722 | kill_wait_one_lwp (lp->ptid.lwp ()); |
1d2736d4 PA |
3723 | return 0; |
3724 | } | |
3725 | ||
0d36baa9 | 3726 | /* Kill the fork/clone child of LP if it has an unfollowed child. */ |
1d2736d4 | 3727 | |
0d36baa9 PA |
3728 | static int |
3729 | kill_unfollowed_child_callback (lwp_info *lp) | |
1d2736d4 | 3730 | { |
6b09f134 | 3731 | std::optional<target_waitstatus> ws = get_pending_child_status (lp); |
0d36baa9 | 3732 | if (ws.has_value ()) |
08036331 | 3733 | { |
0d36baa9 PA |
3734 | ptid_t child_ptid = ws->child_ptid (); |
3735 | int child_pid = child_ptid.pid (); | |
3736 | int child_lwp = child_ptid.lwp (); | |
08036331 | 3737 | |
0d36baa9 PA |
3738 | kill_one_lwp (child_lwp); |
3739 | kill_wait_one_lwp (child_lwp); | |
08036331 | 3740 | |
0d36baa9 PA |
3741 | /* Let the arch-specific native code know this process is |
3742 | gone. */ | |
3743 | if (ws->kind () != TARGET_WAITKIND_THREAD_CLONED) | |
3744 | linux_target->low_forget_process (child_pid); | |
08036331 | 3745 | } |
0d36baa9 PA |
3746 | |
3747 | return 0; | |
1d2736d4 PA |
3748 | } |
3749 | ||
f6ac5f3d PA |
3750 | void |
3751 | linux_nat_target::kill () | |
d6b0e80f | 3752 | { |
0d36baa9 PA |
3753 | ptid_t pid_ptid (inferior_ptid.pid ()); |
3754 | ||
3755 | /* If we're stopped while forking/cloning and we haven't followed | |
3756 | yet, kill the child task. We need to do this first because the | |
f973ed9c | 3757 | parent will be sleeping if this is a vfork. */ |
0d36baa9 | 3758 | iterate_over_lwps (pid_ptid, kill_unfollowed_child_callback); |
f973ed9c DJ |
3759 | |
3760 | if (forks_exist_p ()) | |
7feb7d06 | 3761 | linux_fork_killall (); |
f973ed9c DJ |
3762 | else |
3763 | { | |
4c28f408 | 3764 | /* Stop all threads before killing them, since ptrace requires |
30baf67b | 3765 | that the thread is stopped to successfully PTRACE_KILL. */ |
0d36baa9 | 3766 | iterate_over_lwps (pid_ptid, stop_callback); |
4c28f408 PA |
3767 | /* ... and wait until all of them have reported back that |
3768 | they're no longer running. */ | |
0d36baa9 | 3769 | iterate_over_lwps (pid_ptid, stop_wait_callback); |
4c28f408 | 3770 | |
f973ed9c | 3771 | /* Kill all LWP's ... */ |
0d36baa9 | 3772 | iterate_over_lwps (pid_ptid, kill_callback); |
f973ed9c DJ |
3773 | |
3774 | /* ... and wait until we've flushed all events. */ | |
0d36baa9 | 3775 | iterate_over_lwps (pid_ptid, kill_wait_callback); |
f973ed9c DJ |
3776 | } |
3777 | ||
bc1e6c81 | 3778 | target_mourn_inferior (inferior_ptid); |
d6b0e80f AC |
3779 | } |
3780 | ||
f6ac5f3d PA |
3781 | void |
3782 | linux_nat_target::mourn_inferior () | |
d6b0e80f | 3783 | { |
b26b06dd AB |
3784 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
3785 | ||
e99b03dc | 3786 | int pid = inferior_ptid.pid (); |
26cb8b7c PA |
3787 | |
3788 | purge_lwp_list (pid); | |
d6b0e80f | 3789 | |
8a89ddbd | 3790 | close_proc_mem_file (pid); |
05c06f31 | 3791 | |
f973ed9c | 3792 | if (! forks_exist_p ()) |
d90e17a7 | 3793 | /* Normal case, no other forks available. */ |
f6ac5f3d | 3794 | inf_ptrace_target::mourn_inferior (); |
f973ed9c DJ |
3795 | else |
3796 | /* Multi-fork case. The current inferior_ptid has exited, but | |
3797 | there are other viable forks to debug. Delete the exiting | |
3798 | one and context-switch to the first available. */ | |
3799 | linux_fork_mourn_inferior (); | |
26cb8b7c PA |
3800 | |
3801 | /* Let the arch-specific native code know this process is gone. */ | |
135340af | 3802 | linux_target->low_forget_process (pid); |
d6b0e80f AC |
3803 | } |
3804 | ||
5b009018 PA |
3805 | /* Convert a native/host siginfo object, into/from the siginfo in the |
3806 | layout of the inferiors' architecture. */ | |
3807 | ||
3808 | static void | |
a5362b9a | 3809 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
5b009018 | 3810 | { |
135340af PA |
3811 | /* If the low target didn't do anything, then just do a straight |
3812 | memcpy. */ | |
3813 | if (!linux_target->low_siginfo_fixup (siginfo, inf_siginfo, direction)) | |
5b009018 PA |
3814 | { |
3815 | if (direction == 1) | |
a5362b9a | 3816 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
5b009018 | 3817 | else |
a5362b9a | 3818 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
5b009018 PA |
3819 | } |
3820 | } | |
3821 | ||
9b409511 | 3822 | static enum target_xfer_status |
7154e786 | 3823 | linux_xfer_siginfo (ptid_t ptid, enum target_object object, |
dda83cd7 | 3824 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
3825 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
3826 | ULONGEST *xfered_len) | |
4aa995e1 | 3827 | { |
a5362b9a TS |
3828 | siginfo_t siginfo; |
3829 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; | |
4aa995e1 PA |
3830 | |
3831 | gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO); | |
3832 | gdb_assert (readbuf || writebuf); | |
3833 | ||
4aa995e1 | 3834 | if (offset > sizeof (siginfo)) |
2ed4b548 | 3835 | return TARGET_XFER_E_IO; |
4aa995e1 | 3836 | |
7154e786 | 3837 | if (!linux_nat_get_siginfo (ptid, &siginfo)) |
2ed4b548 | 3838 | return TARGET_XFER_E_IO; |
4aa995e1 | 3839 | |
5b009018 PA |
3840 | /* When GDB is built as a 64-bit application, ptrace writes into |
3841 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
3842 | inferior with a 64-bit GDB should look the same as debugging it | |
3843 | with a 32-bit GDB, we need to convert it. GDB core always sees | |
3844 | the converted layout, so any read/write will have to be done | |
3845 | post-conversion. */ | |
3846 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
3847 | ||
4aa995e1 PA |
3848 | if (offset + len > sizeof (siginfo)) |
3849 | len = sizeof (siginfo) - offset; | |
3850 | ||
3851 | if (readbuf != NULL) | |
5b009018 | 3852 | memcpy (readbuf, inf_siginfo + offset, len); |
4aa995e1 PA |
3853 | else |
3854 | { | |
5b009018 PA |
3855 | memcpy (inf_siginfo + offset, writebuf, len); |
3856 | ||
3857 | /* Convert back to ptrace layout before flushing it out. */ | |
3858 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
3859 | ||
7154e786 | 3860 | int pid = get_ptrace_pid (ptid); |
4aa995e1 PA |
3861 | errno = 0; |
3862 | ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3863 | if (errno != 0) | |
2ed4b548 | 3864 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3865 | } |
3866 | ||
9b409511 YQ |
3867 | *xfered_len = len; |
3868 | return TARGET_XFER_OK; | |
4aa995e1 PA |
3869 | } |
3870 | ||
9b409511 | 3871 | static enum target_xfer_status |
f6ac5f3d PA |
3872 | linux_nat_xfer_osdata (enum target_object object, |
3873 | const char *annex, gdb_byte *readbuf, | |
3874 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, | |
3875 | ULONGEST *xfered_len); | |
3876 | ||
f6ac5f3d | 3877 | static enum target_xfer_status |
f9f593dd SM |
3878 | linux_proc_xfer_memory_partial (int pid, gdb_byte *readbuf, |
3879 | const gdb_byte *writebuf, ULONGEST offset, | |
3880 | LONGEST len, ULONGEST *xfered_len); | |
f6ac5f3d PA |
3881 | |
3882 | enum target_xfer_status | |
3883 | linux_nat_target::xfer_partial (enum target_object object, | |
3884 | const char *annex, gdb_byte *readbuf, | |
3885 | const gdb_byte *writebuf, | |
3886 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) | |
d6b0e80f | 3887 | { |
4aa995e1 | 3888 | if (object == TARGET_OBJECT_SIGNAL_INFO) |
7154e786 | 3889 | return linux_xfer_siginfo (inferior_ptid, object, annex, readbuf, writebuf, |
9b409511 | 3890 | offset, len, xfered_len); |
4aa995e1 | 3891 | |
c35b1492 PA |
3892 | /* The target is connected but no live inferior is selected. Pass |
3893 | this request down to a lower stratum (e.g., the executable | |
3894 | file). */ | |
d7e15655 | 3895 | if (object == TARGET_OBJECT_MEMORY && inferior_ptid == null_ptid) |
9b409511 | 3896 | return TARGET_XFER_EOF; |
c35b1492 | 3897 | |
f6ac5f3d PA |
3898 | if (object == TARGET_OBJECT_AUXV) |
3899 | return memory_xfer_auxv (this, object, annex, readbuf, writebuf, | |
3900 | offset, len, xfered_len); | |
3901 | ||
3902 | if (object == TARGET_OBJECT_OSDATA) | |
3903 | return linux_nat_xfer_osdata (object, annex, readbuf, writebuf, | |
3904 | offset, len, xfered_len); | |
d6b0e80f | 3905 | |
f6ac5f3d PA |
3906 | if (object == TARGET_OBJECT_MEMORY) |
3907 | { | |
05c06f31 PA |
3908 | /* GDB calculates all addresses in the largest possible address |
3909 | width. The address width must be masked before its final use | |
3910 | by linux_proc_xfer_partial. | |
3911 | ||
3912 | Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ | |
99d9c3b9 | 3913 | int addr_bit = gdbarch_addr_bit (current_inferior ()->arch ()); |
f6ac5f3d PA |
3914 | |
3915 | if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) | |
3916 | offset &= ((ULONGEST) 1 << addr_bit) - 1; | |
f6ac5f3d | 3917 | |
dd09fe0d KS |
3918 | /* If /proc/pid/mem is writable, don't fallback to ptrace. If |
3919 | the write via /proc/pid/mem fails because the inferior execed | |
3920 | (and we haven't seen the exec event yet), a subsequent ptrace | |
3921 | poke would incorrectly write memory to the post-exec address | |
3922 | space, while the core was trying to write to the pre-exec | |
3923 | address space. */ | |
3924 | if (proc_mem_file_is_writable ()) | |
f9f593dd SM |
3925 | return linux_proc_xfer_memory_partial (inferior_ptid.pid (), readbuf, |
3926 | writebuf, offset, len, | |
3927 | xfered_len); | |
05c06f31 | 3928 | } |
f6ac5f3d PA |
3929 | |
3930 | return inf_ptrace_target::xfer_partial (object, annex, readbuf, writebuf, | |
3931 | offset, len, xfered_len); | |
d6b0e80f AC |
3932 | } |
3933 | ||
57810aa7 | 3934 | bool |
f6ac5f3d | 3935 | linux_nat_target::thread_alive (ptid_t ptid) |
28439f5e | 3936 | { |
4a6ed09b PA |
3937 | /* As long as a PTID is in lwp list, consider it alive. */ |
3938 | return find_lwp_pid (ptid) != NULL; | |
28439f5e PA |
3939 | } |
3940 | ||
8a06aea7 PA |
3941 | /* Implement the to_update_thread_list target method for this |
3942 | target. */ | |
3943 | ||
f6ac5f3d PA |
3944 | void |
3945 | linux_nat_target::update_thread_list () | |
8a06aea7 | 3946 | { |
4a6ed09b PA |
3947 | /* We add/delete threads from the list as clone/exit events are |
3948 | processed, so just try deleting exited threads still in the | |
3949 | thread list. */ | |
3950 | delete_exited_threads (); | |
a6904d5a PA |
3951 | |
3952 | /* Update the processor core that each lwp/thread was last seen | |
3953 | running on. */ | |
901b9821 | 3954 | for (lwp_info *lwp : all_lwps ()) |
1ad3de98 PA |
3955 | { |
3956 | /* Avoid accessing /proc if the thread hasn't run since we last | |
3957 | time we fetched the thread's core. Accessing /proc becomes | |
3958 | noticeably expensive when we have thousands of LWPs. */ | |
3959 | if (lwp->core == -1) | |
3960 | lwp->core = linux_common_core_of_thread (lwp->ptid); | |
3961 | } | |
8a06aea7 PA |
3962 | } |
3963 | ||
a068643d | 3964 | std::string |
f6ac5f3d | 3965 | linux_nat_target::pid_to_str (ptid_t ptid) |
d6b0e80f | 3966 | { |
15a9e13e | 3967 | if (ptid.lwp_p () |
e38504b3 | 3968 | && (ptid.pid () != ptid.lwp () |
e99b03dc | 3969 | || num_lwps (ptid.pid ()) > 1)) |
a068643d | 3970 | return string_printf ("LWP %ld", ptid.lwp ()); |
d6b0e80f AC |
3971 | |
3972 | return normal_pid_to_str (ptid); | |
3973 | } | |
3974 | ||
f6ac5f3d PA |
3975 | const char * |
3976 | linux_nat_target::thread_name (struct thread_info *thr) | |
4694da01 | 3977 | { |
79efa585 | 3978 | return linux_proc_tid_get_name (thr->ptid); |
4694da01 TT |
3979 | } |
3980 | ||
dba24537 AC |
3981 | /* Accepts an integer PID; Returns a string representing a file that |
3982 | can be opened to get the symbols for the child process. */ | |
3983 | ||
0e90c441 | 3984 | const char * |
f6ac5f3d | 3985 | linux_nat_target::pid_to_exec_file (int pid) |
dba24537 | 3986 | { |
e0d86d2c | 3987 | return linux_proc_pid_to_exec_file (pid); |
dba24537 AC |
3988 | } |
3989 | ||
8a89ddbd PA |
3990 | /* Object representing an /proc/PID/mem open file. We keep one such |
3991 | file open per inferior. | |
3992 | ||
3993 | It might be tempting to think about only ever opening one file at | |
3994 | most for all inferiors, closing/reopening the file as we access | |
3995 | memory of different inferiors, to minimize number of file | |
3996 | descriptors open, which can otherwise run into resource limits. | |
3997 | However, that does not work correctly -- if the inferior execs and | |
3998 | we haven't processed the exec event yet, and, we opened a | |
3999 | /proc/PID/mem file, we will get a mem file accessing the post-exec | |
4000 | address space, thinking we're opening it for the pre-exec address | |
4001 | space. That is dangerous as we can poke memory (e.g. clearing | |
4002 | breakpoints) in the post-exec memory by mistake, corrupting the | |
4003 | inferior. For that reason, we open the mem file as early as | |
4004 | possible, right after spawning, forking or attaching to the | |
4005 | inferior, when the inferior is stopped and thus before it has a | |
4006 | chance of execing. | |
4007 | ||
4008 | Note that after opening the file, even if the thread we opened it | |
4009 | for subsequently exits, the open file is still usable for accessing | |
4010 | memory. It's only when the whole process exits or execs that the | |
4011 | file becomes invalid, at which point reads/writes return EOF. */ | |
4012 | ||
4013 | class proc_mem_file | |
4014 | { | |
4015 | public: | |
4016 | proc_mem_file (ptid_t ptid, int fd) | |
4017 | : m_ptid (ptid), m_fd (fd) | |
4018 | { | |
4019 | gdb_assert (m_fd != -1); | |
4020 | } | |
05c06f31 | 4021 | |
8a89ddbd | 4022 | ~proc_mem_file () |
05c06f31 | 4023 | { |
89662f69 | 4024 | linux_nat_debug_printf ("closing fd %d for /proc/%d/task/%ld/mem", |
8a89ddbd PA |
4025 | m_fd, m_ptid.pid (), m_ptid.lwp ()); |
4026 | close (m_fd); | |
05c06f31 | 4027 | } |
05c06f31 | 4028 | |
8a89ddbd PA |
4029 | DISABLE_COPY_AND_ASSIGN (proc_mem_file); |
4030 | ||
4031 | int fd () | |
4032 | { | |
4033 | return m_fd; | |
4034 | } | |
4035 | ||
4036 | private: | |
4037 | /* The LWP this file was opened for. Just for debugging | |
4038 | purposes. */ | |
4039 | ptid_t m_ptid; | |
4040 | ||
4041 | /* The file descriptor. */ | |
4042 | int m_fd = -1; | |
4043 | }; | |
4044 | ||
4045 | /* The map between an inferior process id, and the open /proc/PID/mem | |
4046 | file. This is stored in a map instead of in a per-inferior | |
4047 | structure because we need to be able to access memory of processes | |
4048 | which don't have a corresponding struct inferior object. E.g., | |
4049 | with "detach-on-fork on" (the default), and "follow-fork parent" | |
4050 | (also default), we don't create an inferior for the fork child, but | |
4051 | we still need to remove breakpoints from the fork child's | |
4052 | memory. */ | |
4053 | static std::unordered_map<int, proc_mem_file> proc_mem_file_map; | |
4054 | ||
4055 | /* Close the /proc/PID/mem file for PID. */ | |
05c06f31 PA |
4056 | |
4057 | static void | |
8a89ddbd | 4058 | close_proc_mem_file (pid_t pid) |
dba24537 | 4059 | { |
8a89ddbd | 4060 | proc_mem_file_map.erase (pid); |
05c06f31 | 4061 | } |
dba24537 | 4062 | |
8a89ddbd PA |
4063 | /* Open the /proc/PID/mem file for the process (thread group) of PTID. |
4064 | We actually open /proc/PID/task/LWP/mem, as that's the LWP we know | |
4065 | exists and is stopped right now. We prefer the | |
4066 | /proc/PID/task/LWP/mem form over /proc/LWP/mem to avoid tid-reuse | |
4067 | races, just in case this is ever called on an already-waited | |
4068 | LWP. */ | |
dba24537 | 4069 | |
8a89ddbd PA |
4070 | static void |
4071 | open_proc_mem_file (ptid_t ptid) | |
05c06f31 | 4072 | { |
8a89ddbd PA |
4073 | auto iter = proc_mem_file_map.find (ptid.pid ()); |
4074 | gdb_assert (iter == proc_mem_file_map.end ()); | |
dba24537 | 4075 | |
8a89ddbd PA |
4076 | char filename[64]; |
4077 | xsnprintf (filename, sizeof filename, | |
4078 | "/proc/%d/task/%ld/mem", ptid.pid (), ptid.lwp ()); | |
4079 | ||
4080 | int fd = gdb_open_cloexec (filename, O_RDWR | O_LARGEFILE, 0).release (); | |
05c06f31 | 4081 | |
8a89ddbd PA |
4082 | if (fd == -1) |
4083 | { | |
4084 | warning (_("opening /proc/PID/mem file for lwp %d.%ld failed: %s (%d)"), | |
4085 | ptid.pid (), ptid.lwp (), | |
4086 | safe_strerror (errno), errno); | |
4087 | return; | |
05c06f31 PA |
4088 | } |
4089 | ||
8a89ddbd PA |
4090 | proc_mem_file_map.emplace (std::piecewise_construct, |
4091 | std::forward_as_tuple (ptid.pid ()), | |
4092 | std::forward_as_tuple (ptid, fd)); | |
4093 | ||
9221923c | 4094 | linux_nat_debug_printf ("opened fd %d for lwp %d.%ld", |
8a89ddbd PA |
4095 | fd, ptid.pid (), ptid.lwp ()); |
4096 | } | |
4097 | ||
1bcb0708 PA |
4098 | /* Helper for linux_proc_xfer_memory_partial and |
4099 | proc_mem_file_is_writable. FD is the already opened /proc/pid/mem | |
4100 | file, and PID is the pid of the corresponding process. The rest of | |
4101 | the arguments are like linux_proc_xfer_memory_partial's. */ | |
8a89ddbd PA |
4102 | |
4103 | static enum target_xfer_status | |
1bcb0708 PA |
4104 | linux_proc_xfer_memory_partial_fd (int fd, int pid, |
4105 | gdb_byte *readbuf, const gdb_byte *writebuf, | |
4106 | ULONGEST offset, LONGEST len, | |
4107 | ULONGEST *xfered_len) | |
8a89ddbd PA |
4108 | { |
4109 | ssize_t ret; | |
4110 | ||
8a89ddbd | 4111 | gdb_assert (fd != -1); |
dba24537 | 4112 | |
31a56a22 PA |
4113 | /* Use pread64/pwrite64 if available, since they save a syscall and |
4114 | can handle 64-bit offsets even on 32-bit platforms (for instance, | |
4115 | SPARC debugging a SPARC64 application). But only use them if the | |
4116 | offset isn't so high that when cast to off_t it'd be negative, as | |
4117 | seen on SPARC64. pread64/pwrite64 outright reject such offsets. | |
4118 | lseek does not. */ | |
dba24537 | 4119 | #ifdef HAVE_PREAD64 |
31a56a22 PA |
4120 | if ((off_t) offset >= 0) |
4121 | ret = (readbuf != nullptr | |
4122 | ? pread64 (fd, readbuf, len, offset) | |
4123 | : pwrite64 (fd, writebuf, len, offset)); | |
4124 | else | |
dba24537 | 4125 | #endif |
31a56a22 PA |
4126 | { |
4127 | ret = lseek (fd, offset, SEEK_SET); | |
4128 | if (ret != -1) | |
4129 | ret = (readbuf != nullptr | |
4130 | ? read (fd, readbuf, len) | |
4131 | : write (fd, writebuf, len)); | |
4132 | } | |
dba24537 | 4133 | |
05c06f31 PA |
4134 | if (ret == -1) |
4135 | { | |
9221923c | 4136 | linux_nat_debug_printf ("accessing fd %d for pid %d failed: %s (%d)", |
1bcb0708 | 4137 | fd, pid, safe_strerror (errno), errno); |
284b6bb5 | 4138 | return TARGET_XFER_E_IO; |
05c06f31 PA |
4139 | } |
4140 | else if (ret == 0) | |
4141 | { | |
8a89ddbd PA |
4142 | /* EOF means the address space is gone, the whole process exited |
4143 | or execed. */ | |
9221923c | 4144 | linux_nat_debug_printf ("accessing fd %d for pid %d got EOF", |
1bcb0708 | 4145 | fd, pid); |
05c06f31 PA |
4146 | return TARGET_XFER_EOF; |
4147 | } | |
9b409511 YQ |
4148 | else |
4149 | { | |
8a89ddbd | 4150 | *xfered_len = ret; |
9b409511 YQ |
4151 | return TARGET_XFER_OK; |
4152 | } | |
05c06f31 | 4153 | } |
efcbbd14 | 4154 | |
1bcb0708 PA |
4155 | /* Implement the to_xfer_partial target method using /proc/PID/mem. |
4156 | Because we can use a single read/write call, this can be much more | |
4157 | efficient than banging away at PTRACE_PEEKTEXT. Also, unlike | |
4158 | PTRACE_PEEKTEXT/PTRACE_POKETEXT, this works with running | |
4159 | threads. */ | |
4160 | ||
4161 | static enum target_xfer_status | |
f9f593dd SM |
4162 | linux_proc_xfer_memory_partial (int pid, gdb_byte *readbuf, |
4163 | const gdb_byte *writebuf, ULONGEST offset, | |
4164 | LONGEST len, ULONGEST *xfered_len) | |
1bcb0708 | 4165 | { |
1bcb0708 PA |
4166 | auto iter = proc_mem_file_map.find (pid); |
4167 | if (iter == proc_mem_file_map.end ()) | |
4168 | return TARGET_XFER_EOF; | |
4169 | ||
4170 | int fd = iter->second.fd (); | |
4171 | ||
4172 | return linux_proc_xfer_memory_partial_fd (fd, pid, readbuf, writebuf, offset, | |
4173 | len, xfered_len); | |
4174 | } | |
4175 | ||
4176 | /* Check whether /proc/pid/mem is writable in the current kernel, and | |
4177 | return true if so. It wasn't writable before Linux 2.6.39, but | |
4178 | there's no way to know whether the feature was backported to older | |
4179 | kernels. So we check to see if it works. The result is cached, | |
3bfdcabb | 4180 | and this is guaranteed to be called once early during inferior |
9dff6a5d PA |
4181 | startup, so that any warning is printed out consistently between |
4182 | GDB invocations. Note we don't call it during GDB startup instead | |
4183 | though, because then we might warn with e.g. just "gdb --version" | |
4184 | on sandboxed systems. See PR gdb/29907. */ | |
1bcb0708 PA |
4185 | |
4186 | static bool | |
4187 | proc_mem_file_is_writable () | |
4188 | { | |
6b09f134 | 4189 | static std::optional<bool> writable; |
1bcb0708 PA |
4190 | |
4191 | if (writable.has_value ()) | |
4192 | return *writable; | |
4193 | ||
4194 | writable.emplace (false); | |
4195 | ||
4196 | /* We check whether /proc/pid/mem is writable by trying to write to | |
4197 | one of our variables via /proc/self/mem. */ | |
4198 | ||
4199 | int fd = gdb_open_cloexec ("/proc/self/mem", O_RDWR | O_LARGEFILE, 0).release (); | |
4200 | ||
4201 | if (fd == -1) | |
4202 | { | |
4203 | warning (_("opening /proc/self/mem file failed: %s (%d)"), | |
4204 | safe_strerror (errno), errno); | |
4205 | return *writable; | |
4206 | } | |
4207 | ||
4208 | SCOPE_EXIT { close (fd); }; | |
4209 | ||
4210 | /* This is the variable we try to write to. Note OFFSET below. */ | |
4211 | volatile gdb_byte test_var = 0; | |
4212 | ||
4213 | gdb_byte writebuf[] = {0x55}; | |
4214 | ULONGEST offset = (uintptr_t) &test_var; | |
4215 | ULONGEST xfered_len; | |
4216 | ||
4217 | enum target_xfer_status res | |
4218 | = linux_proc_xfer_memory_partial_fd (fd, getpid (), nullptr, writebuf, | |
4219 | offset, 1, &xfered_len); | |
4220 | ||
4221 | if (res == TARGET_XFER_OK) | |
4222 | { | |
4223 | gdb_assert (xfered_len == 1); | |
4224 | gdb_assert (test_var == 0x55); | |
4225 | /* Success. */ | |
4226 | *writable = true; | |
4227 | } | |
4228 | ||
4229 | return *writable; | |
4230 | } | |
4231 | ||
dba24537 AC |
4232 | /* Parse LINE as a signal set and add its set bits to SIGS. */ |
4233 | ||
4234 | static void | |
4235 | add_line_to_sigset (const char *line, sigset_t *sigs) | |
4236 | { | |
4237 | int len = strlen (line) - 1; | |
4238 | const char *p; | |
4239 | int signum; | |
4240 | ||
4241 | if (line[len] != '\n') | |
8a3fe4f8 | 4242 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4243 | |
4244 | p = line; | |
4245 | signum = len * 4; | |
4246 | while (len-- > 0) | |
4247 | { | |
4248 | int digit; | |
4249 | ||
4250 | if (*p >= '0' && *p <= '9') | |
4251 | digit = *p - '0'; | |
4252 | else if (*p >= 'a' && *p <= 'f') | |
4253 | digit = *p - 'a' + 10; | |
4254 | else | |
8a3fe4f8 | 4255 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4256 | |
4257 | signum -= 4; | |
4258 | ||
4259 | if (digit & 1) | |
4260 | sigaddset (sigs, signum + 1); | |
4261 | if (digit & 2) | |
4262 | sigaddset (sigs, signum + 2); | |
4263 | if (digit & 4) | |
4264 | sigaddset (sigs, signum + 3); | |
4265 | if (digit & 8) | |
4266 | sigaddset (sigs, signum + 4); | |
4267 | ||
4268 | p++; | |
4269 | } | |
4270 | } | |
4271 | ||
4272 | /* Find process PID's pending signals from /proc/pid/status and set | |
4273 | SIGS to match. */ | |
4274 | ||
4275 | void | |
3e43a32a MS |
4276 | linux_proc_pending_signals (int pid, sigset_t *pending, |
4277 | sigset_t *blocked, sigset_t *ignored) | |
dba24537 | 4278 | { |
d8d2a3ee | 4279 | char buffer[PATH_MAX], fname[PATH_MAX]; |
dba24537 AC |
4280 | |
4281 | sigemptyset (pending); | |
4282 | sigemptyset (blocked); | |
4283 | sigemptyset (ignored); | |
cde33bf1 | 4284 | xsnprintf (fname, sizeof fname, "/proc/%d/status", pid); |
d419f42d | 4285 | gdb_file_up procfile = gdb_fopen_cloexec (fname, "r"); |
dba24537 | 4286 | if (procfile == NULL) |
8a3fe4f8 | 4287 | error (_("Could not open %s"), fname); |
dba24537 | 4288 | |
d419f42d | 4289 | while (fgets (buffer, PATH_MAX, procfile.get ()) != NULL) |
dba24537 AC |
4290 | { |
4291 | /* Normal queued signals are on the SigPnd line in the status | |
4292 | file. However, 2.6 kernels also have a "shared" pending | |
4293 | queue for delivering signals to a thread group, so check for | |
4294 | a ShdPnd line also. | |
4295 | ||
4296 | Unfortunately some Red Hat kernels include the shared pending | |
4297 | queue but not the ShdPnd status field. */ | |
4298 | ||
61012eef | 4299 | if (startswith (buffer, "SigPnd:\t")) |
dba24537 | 4300 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4301 | else if (startswith (buffer, "ShdPnd:\t")) |
dba24537 | 4302 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4303 | else if (startswith (buffer, "SigBlk:\t")) |
dba24537 | 4304 | add_line_to_sigset (buffer + 8, blocked); |
61012eef | 4305 | else if (startswith (buffer, "SigIgn:\t")) |
dba24537 AC |
4306 | add_line_to_sigset (buffer + 8, ignored); |
4307 | } | |
dba24537 AC |
4308 | } |
4309 | ||
9b409511 | 4310 | static enum target_xfer_status |
f6ac5f3d | 4311 | linux_nat_xfer_osdata (enum target_object object, |
e0881a8e | 4312 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
4313 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
4314 | ULONGEST *xfered_len) | |
07e059b5 | 4315 | { |
07e059b5 VP |
4316 | gdb_assert (object == TARGET_OBJECT_OSDATA); |
4317 | ||
9b409511 YQ |
4318 | *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len); |
4319 | if (*xfered_len == 0) | |
4320 | return TARGET_XFER_EOF; | |
4321 | else | |
4322 | return TARGET_XFER_OK; | |
07e059b5 VP |
4323 | } |
4324 | ||
f6ac5f3d PA |
4325 | std::vector<static_tracepoint_marker> |
4326 | linux_nat_target::static_tracepoint_markers_by_strid (const char *strid) | |
5808517f YQ |
4327 | { |
4328 | char s[IPA_CMD_BUF_SIZE]; | |
e99b03dc | 4329 | int pid = inferior_ptid.pid (); |
5d9310c4 | 4330 | std::vector<static_tracepoint_marker> markers; |
256642e8 | 4331 | const char *p = s; |
184ea2f7 | 4332 | ptid_t ptid = ptid_t (pid, 0); |
5d9310c4 | 4333 | static_tracepoint_marker marker; |
5808517f YQ |
4334 | |
4335 | /* Pause all */ | |
4336 | target_stop (ptid); | |
4337 | ||
81aa19c3 | 4338 | strcpy (s, "qTfSTM"); |
42476b70 | 4339 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f | 4340 | |
1db93f14 TT |
4341 | /* Unpause all. */ |
4342 | SCOPE_EXIT { target_continue_no_signal (ptid); }; | |
5808517f YQ |
4343 | |
4344 | while (*p++ == 'm') | |
4345 | { | |
5808517f YQ |
4346 | do |
4347 | { | |
5d9310c4 | 4348 | parse_static_tracepoint_marker_definition (p, &p, &marker); |
5808517f | 4349 | |
5d9310c4 SM |
4350 | if (strid == NULL || marker.str_id == strid) |
4351 | markers.push_back (std::move (marker)); | |
5808517f YQ |
4352 | } |
4353 | while (*p++ == ','); /* comma-separated list */ | |
4354 | ||
81aa19c3 | 4355 | strcpy (s, "qTsSTM"); |
42476b70 | 4356 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4357 | p = s; |
4358 | } | |
4359 | ||
5808517f YQ |
4360 | return markers; |
4361 | } | |
4362 | ||
b84876c2 PA |
4363 | /* target_can_async_p implementation. */ |
4364 | ||
57810aa7 | 4365 | bool |
f6ac5f3d | 4366 | linux_nat_target::can_async_p () |
b84876c2 | 4367 | { |
fce6cd34 AB |
4368 | /* This flag should be checked in the common target.c code. */ |
4369 | gdb_assert (target_async_permitted); | |
4370 | ||
4371 | /* Otherwise, this targets is always able to support async mode. */ | |
4372 | return true; | |
b84876c2 PA |
4373 | } |
4374 | ||
57810aa7 | 4375 | bool |
f6ac5f3d | 4376 | linux_nat_target::supports_non_stop () |
9908b566 | 4377 | { |
f80c8ec4 | 4378 | return true; |
9908b566 VP |
4379 | } |
4380 | ||
fbea99ea PA |
4381 | /* to_always_non_stop_p implementation. */ |
4382 | ||
57810aa7 | 4383 | bool |
f6ac5f3d | 4384 | linux_nat_target::always_non_stop_p () |
fbea99ea | 4385 | { |
f80c8ec4 | 4386 | return true; |
fbea99ea PA |
4387 | } |
4388 | ||
57810aa7 | 4389 | bool |
f6ac5f3d | 4390 | linux_nat_target::supports_multi_process () |
d90e17a7 | 4391 | { |
aee91db3 | 4392 | return true; |
d90e17a7 PA |
4393 | } |
4394 | ||
57810aa7 | 4395 | bool |
f6ac5f3d | 4396 | linux_nat_target::supports_disable_randomization () |
03583c20 | 4397 | { |
f80c8ec4 | 4398 | return true; |
03583c20 UW |
4399 | } |
4400 | ||
7feb7d06 PA |
4401 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
4402 | so we notice when any child changes state, and notify the | |
4403 | event-loop; it allows us to use sigsuspend in linux_nat_wait_1 | |
4404 | above to wait for the arrival of a SIGCHLD. */ | |
4405 | ||
b84876c2 | 4406 | static void |
7feb7d06 | 4407 | sigchld_handler (int signo) |
b84876c2 | 4408 | { |
7feb7d06 PA |
4409 | int old_errno = errno; |
4410 | ||
01124a23 | 4411 | if (debug_linux_nat) |
da5bd37e | 4412 | gdb_stdlog->write_async_safe ("sigchld\n", sizeof ("sigchld\n") - 1); |
7feb7d06 | 4413 | |
b146ba14 JB |
4414 | if (signo == SIGCHLD) |
4415 | { | |
4416 | /* Let the event loop know that there are events to handle. */ | |
4417 | linux_nat_target::async_file_mark_if_open (); | |
4418 | } | |
7feb7d06 PA |
4419 | |
4420 | errno = old_errno; | |
4421 | } | |
4422 | ||
4423 | /* Callback registered with the target events file descriptor. */ | |
4424 | ||
4425 | static void | |
4426 | handle_target_event (int error, gdb_client_data client_data) | |
4427 | { | |
b1a35af2 | 4428 | inferior_event_handler (INF_REG_EVENT); |
7feb7d06 PA |
4429 | } |
4430 | ||
b84876c2 PA |
4431 | /* target_async implementation. */ |
4432 | ||
f6ac5f3d | 4433 | void |
4a570176 | 4434 | linux_nat_target::async (bool enable) |
b84876c2 | 4435 | { |
4a570176 | 4436 | if (enable == is_async_p ()) |
b146ba14 JB |
4437 | return; |
4438 | ||
4439 | /* Block child signals while we create/destroy the pipe, as their | |
4440 | handler writes to it. */ | |
4441 | gdb::block_signals blocker; | |
4442 | ||
6a3753b3 | 4443 | if (enable) |
b84876c2 | 4444 | { |
b146ba14 | 4445 | if (!async_file_open ()) |
f34652de | 4446 | internal_error ("creating event pipe failed."); |
b146ba14 JB |
4447 | |
4448 | add_file_handler (async_wait_fd (), handle_target_event, NULL, | |
4449 | "linux-nat"); | |
4450 | ||
4451 | /* There may be pending events to handle. Tell the event loop | |
4452 | to poll them. */ | |
4453 | async_file_mark (); | |
b84876c2 PA |
4454 | } |
4455 | else | |
4456 | { | |
b146ba14 JB |
4457 | delete_file_handler (async_wait_fd ()); |
4458 | async_file_close (); | |
b84876c2 | 4459 | } |
b84876c2 PA |
4460 | } |
4461 | ||
a493e3e2 | 4462 | /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other |
252fbfc8 PA |
4463 | event came out. */ |
4464 | ||
4c28f408 | 4465 | static int |
d3a70e03 | 4466 | linux_nat_stop_lwp (struct lwp_info *lwp) |
4c28f408 | 4467 | { |
d90e17a7 | 4468 | if (!lwp->stopped) |
252fbfc8 | 4469 | { |
9327494e | 4470 | linux_nat_debug_printf ("running -> suspending %s", |
e53c95d4 | 4471 | lwp->ptid.to_string ().c_str ()); |
252fbfc8 | 4472 | |
252fbfc8 | 4473 | |
25289eb2 PA |
4474 | if (lwp->last_resume_kind == resume_stop) |
4475 | { | |
9327494e SM |
4476 | linux_nat_debug_printf ("already stopping LWP %ld at GDB's request", |
4477 | lwp->ptid.lwp ()); | |
25289eb2 PA |
4478 | return 0; |
4479 | } | |
252fbfc8 | 4480 | |
d3a70e03 | 4481 | stop_callback (lwp); |
25289eb2 | 4482 | lwp->last_resume_kind = resume_stop; |
d90e17a7 PA |
4483 | } |
4484 | else | |
4485 | { | |
4486 | /* Already known to be stopped; do nothing. */ | |
252fbfc8 | 4487 | |
d90e17a7 PA |
4488 | if (debug_linux_nat) |
4489 | { | |
9213a6d7 | 4490 | if (linux_target->find_thread (lwp->ptid)->stop_requested) |
9327494e | 4491 | linux_nat_debug_printf ("already stopped/stop_requested %s", |
e53c95d4 | 4492 | lwp->ptid.to_string ().c_str ()); |
d90e17a7 | 4493 | else |
9327494e | 4494 | linux_nat_debug_printf ("already stopped/no stop_requested yet %s", |
e53c95d4 | 4495 | lwp->ptid.to_string ().c_str ()); |
252fbfc8 PA |
4496 | } |
4497 | } | |
4c28f408 PA |
4498 | return 0; |
4499 | } | |
4500 | ||
f6ac5f3d PA |
4501 | void |
4502 | linux_nat_target::stop (ptid_t ptid) | |
4c28f408 | 4503 | { |
b6e52a0b | 4504 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
d3a70e03 | 4505 | iterate_over_lwps (ptid, linux_nat_stop_lwp); |
bfedc46a PA |
4506 | } |
4507 | ||
dc146f7c VP |
4508 | /* Return the cached value of the processor core for thread PTID. */ |
4509 | ||
f6ac5f3d PA |
4510 | int |
4511 | linux_nat_target::core_of_thread (ptid_t ptid) | |
dc146f7c VP |
4512 | { |
4513 | struct lwp_info *info = find_lwp_pid (ptid); | |
e0881a8e | 4514 | |
dc146f7c VP |
4515 | if (info) |
4516 | return info->core; | |
4517 | return -1; | |
4518 | } | |
4519 | ||
7a6a1731 GB |
4520 | /* Implementation of to_filesystem_is_local. */ |
4521 | ||
57810aa7 | 4522 | bool |
f6ac5f3d | 4523 | linux_nat_target::filesystem_is_local () |
7a6a1731 GB |
4524 | { |
4525 | struct inferior *inf = current_inferior (); | |
4526 | ||
4527 | if (inf->fake_pid_p || inf->pid == 0) | |
57810aa7 | 4528 | return true; |
7a6a1731 GB |
4529 | |
4530 | return linux_ns_same (inf->pid, LINUX_NS_MNT); | |
4531 | } | |
4532 | ||
4533 | /* Convert the INF argument passed to a to_fileio_* method | |
4534 | to a process ID suitable for passing to its corresponding | |
4535 | linux_mntns_* function. If INF is non-NULL then the | |
4536 | caller is requesting the filesystem seen by INF. If INF | |
4537 | is NULL then the caller is requesting the filesystem seen | |
4538 | by the GDB. We fall back to GDB's filesystem in the case | |
4539 | that INF is non-NULL but its PID is unknown. */ | |
4540 | ||
4541 | static pid_t | |
4542 | linux_nat_fileio_pid_of (struct inferior *inf) | |
4543 | { | |
4544 | if (inf == NULL || inf->fake_pid_p || inf->pid == 0) | |
4545 | return getpid (); | |
4546 | else | |
4547 | return inf->pid; | |
4548 | } | |
4549 | ||
4550 | /* Implementation of to_fileio_open. */ | |
4551 | ||
f6ac5f3d PA |
4552 | int |
4553 | linux_nat_target::fileio_open (struct inferior *inf, const char *filename, | |
4554 | int flags, int mode, int warn_if_slow, | |
b872057a | 4555 | fileio_error *target_errno) |
7a6a1731 GB |
4556 | { |
4557 | int nat_flags; | |
4558 | mode_t nat_mode; | |
4559 | int fd; | |
4560 | ||
4561 | if (fileio_to_host_openflags (flags, &nat_flags) == -1 | |
4562 | || fileio_to_host_mode (mode, &nat_mode) == -1) | |
4563 | { | |
4564 | *target_errno = FILEIO_EINVAL; | |
4565 | return -1; | |
4566 | } | |
4567 | ||
4568 | fd = linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf), | |
4569 | filename, nat_flags, nat_mode); | |
4570 | if (fd == -1) | |
4571 | *target_errno = host_to_fileio_error (errno); | |
4572 | ||
4573 | return fd; | |
4574 | } | |
4575 | ||
4576 | /* Implementation of to_fileio_readlink. */ | |
4577 | ||
6b09f134 | 4578 | std::optional<std::string> |
f6ac5f3d | 4579 | linux_nat_target::fileio_readlink (struct inferior *inf, const char *filename, |
b872057a | 4580 | fileio_error *target_errno) |
7a6a1731 GB |
4581 | { |
4582 | char buf[PATH_MAX]; | |
4583 | int len; | |
7a6a1731 GB |
4584 | |
4585 | len = linux_mntns_readlink (linux_nat_fileio_pid_of (inf), | |
4586 | filename, buf, sizeof (buf)); | |
4587 | if (len < 0) | |
4588 | { | |
4589 | *target_errno = host_to_fileio_error (errno); | |
e0d3522b | 4590 | return {}; |
7a6a1731 GB |
4591 | } |
4592 | ||
e0d3522b | 4593 | return std::string (buf, len); |
7a6a1731 GB |
4594 | } |
4595 | ||
4596 | /* Implementation of to_fileio_unlink. */ | |
4597 | ||
f6ac5f3d PA |
4598 | int |
4599 | linux_nat_target::fileio_unlink (struct inferior *inf, const char *filename, | |
b872057a | 4600 | fileio_error *target_errno) |
7a6a1731 GB |
4601 | { |
4602 | int ret; | |
4603 | ||
4604 | ret = linux_mntns_unlink (linux_nat_fileio_pid_of (inf), | |
4605 | filename); | |
4606 | if (ret == -1) | |
4607 | *target_errno = host_to_fileio_error (errno); | |
4608 | ||
4609 | return ret; | |
4610 | } | |
4611 | ||
aa01bd36 PA |
4612 | /* Implementation of the to_thread_events method. */ |
4613 | ||
f6ac5f3d PA |
4614 | void |
4615 | linux_nat_target::thread_events (int enable) | |
aa01bd36 PA |
4616 | { |
4617 | report_thread_events = enable; | |
4618 | } | |
4619 | ||
25b16bc9 PA |
4620 | bool |
4621 | linux_nat_target::supports_set_thread_options (gdb_thread_options options) | |
4622 | { | |
a51e14ef PA |
4623 | constexpr gdb_thread_options supported_options |
4624 | = GDB_THREAD_OPTION_CLONE | GDB_THREAD_OPTION_EXIT; | |
25b16bc9 PA |
4625 | return ((options & supported_options) == options); |
4626 | } | |
4627 | ||
f6ac5f3d PA |
4628 | linux_nat_target::linux_nat_target () |
4629 | { | |
f973ed9c DJ |
4630 | /* We don't change the stratum; this target will sit at |
4631 | process_stratum and thread_db will set at thread_stratum. This | |
4632 | is a little strange, since this is a multi-threaded-capable | |
4633 | target, but we want to be on the stack below thread_db, and we | |
4634 | also want to be used for single-threaded processes. */ | |
f973ed9c DJ |
4635 | } |
4636 | ||
f865ee35 JK |
4637 | /* See linux-nat.h. */ |
4638 | ||
ef632b4b | 4639 | bool |
f865ee35 | 4640 | linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo) |
9f0bdab8 | 4641 | { |
0acd1110 | 4642 | int pid = get_ptrace_pid (ptid); |
7cc662bc | 4643 | return ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo) == 0; |
9f0bdab8 DJ |
4644 | } |
4645 | ||
7b669087 GB |
4646 | /* See nat/linux-nat.h. */ |
4647 | ||
4648 | ptid_t | |
4649 | current_lwp_ptid (void) | |
4650 | { | |
15a9e13e | 4651 | gdb_assert (inferior_ptid.lwp_p ()); |
7b669087 GB |
4652 | return inferior_ptid; |
4653 | } | |
4654 | ||
0ae5b8fa AB |
4655 | /* Implement 'maintenance info linux-lwps'. Displays some basic |
4656 | information about all the current lwp_info objects. */ | |
4657 | ||
4658 | static void | |
4659 | maintenance_info_lwps (const char *arg, int from_tty) | |
4660 | { | |
4661 | if (all_lwps ().size () == 0) | |
4662 | { | |
4663 | gdb_printf ("No Linux LWPs\n"); | |
4664 | return; | |
4665 | } | |
4666 | ||
4667 | /* Start the width at 8 to match the column heading below, then | |
4668 | figure out the widest ptid string. We'll use this to build our | |
4669 | output table below. */ | |
4670 | size_t ptid_width = 8; | |
4671 | for (lwp_info *lp : all_lwps ()) | |
4672 | ptid_width = std::max (ptid_width, lp->ptid.to_string ().size ()); | |
4673 | ||
4674 | /* Setup the table headers. */ | |
4675 | struct ui_out *uiout = current_uiout; | |
4676 | ui_out_emit_table table_emitter (uiout, 2, -1, "linux-lwps"); | |
4677 | uiout->table_header (ptid_width, ui_left, "lwp-ptid", _("LWP Ptid")); | |
4678 | uiout->table_header (9, ui_left, "thread-info", _("Thread ID")); | |
4679 | uiout->table_body (); | |
4680 | ||
4681 | /* Display one table row for each lwp_info. */ | |
4682 | for (lwp_info *lp : all_lwps ()) | |
4683 | { | |
4684 | ui_out_emit_tuple tuple_emitter (uiout, "lwp-entry"); | |
4685 | ||
4686 | thread_info *th = linux_target->find_thread (lp->ptid); | |
4687 | ||
4688 | uiout->field_string ("lwp-ptid", lp->ptid.to_string ().c_str ()); | |
4689 | if (th == nullptr) | |
4690 | uiout->field_string ("thread-info", "None"); | |
4691 | else | |
4692 | uiout->field_string ("thread-info", print_full_thread_id (th)); | |
4693 | ||
4694 | uiout->message ("\n"); | |
4695 | } | |
4696 | } | |
4697 | ||
6c265988 | 4698 | void _initialize_linux_nat (); |
d6b0e80f | 4699 | void |
6c265988 | 4700 | _initialize_linux_nat () |
d6b0e80f | 4701 | { |
8864ef42 | 4702 | add_setshow_boolean_cmd ("linux-nat", class_maintenance, |
b6e52a0b | 4703 | &debug_linux_nat, _("\ |
6a2dbb74 EZ |
4704 | Set debugging of GNU/Linux native target."), _("\ |
4705 | Show debugging of GNU/Linux native target."), _("\ | |
b6e52a0b AB |
4706 | When on, print debug messages relating to the GNU/Linux native target."), |
4707 | nullptr, | |
4708 | show_debug_linux_nat, | |
4709 | &setdebuglist, &showdebuglist); | |
b84876c2 | 4710 | |
7a6a1731 GB |
4711 | add_setshow_boolean_cmd ("linux-namespaces", class_maintenance, |
4712 | &debug_linux_namespaces, _("\ | |
4713 | Set debugging of GNU/Linux namespaces module."), _("\ | |
4714 | Show debugging of GNU/Linux namespaces module."), _("\ | |
4715 | Enables printf debugging output."), | |
4716 | NULL, | |
4717 | NULL, | |
4718 | &setdebuglist, &showdebuglist); | |
4719 | ||
7feb7d06 PA |
4720 | /* Install a SIGCHLD handler. */ |
4721 | sigchld_action.sa_handler = sigchld_handler; | |
4722 | sigemptyset (&sigchld_action.sa_mask); | |
4723 | sigchld_action.sa_flags = SA_RESTART; | |
b84876c2 PA |
4724 | |
4725 | /* Make it the default. */ | |
7feb7d06 | 4726 | sigaction (SIGCHLD, &sigchld_action, NULL); |
d6b0e80f AC |
4727 | |
4728 | /* Make sure we don't block SIGCHLD during a sigsuspend. */ | |
21987b9c | 4729 | gdb_sigmask (SIG_SETMASK, NULL, &suspend_mask); |
d6b0e80f AC |
4730 | sigdelset (&suspend_mask, SIGCHLD); |
4731 | ||
7feb7d06 | 4732 | sigemptyset (&blocked_mask); |
774113b0 PA |
4733 | |
4734 | lwp_lwpid_htab_create (); | |
0ae5b8fa AB |
4735 | |
4736 | add_cmd ("linux-lwps", class_maintenance, maintenance_info_lwps, | |
4737 | _("List the Linux LWPS."), &maintenanceinfolist); | |
d6b0e80f AC |
4738 | } |
4739 | \f | |
4740 | ||
4741 | /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to | |
4742 | the GNU/Linux Threads library and therefore doesn't really belong | |
4743 | here. */ | |
4744 | ||
089436f7 TV |
4745 | /* NPTL reserves the first two RT signals, but does not provide any |
4746 | way for the debugger to query the signal numbers - fortunately | |
4747 | they don't change. */ | |
4748 | static int lin_thread_signals[] = { __SIGRTMIN, __SIGRTMIN + 1 }; | |
d6b0e80f | 4749 | |
089436f7 TV |
4750 | /* See linux-nat.h. */ |
4751 | ||
4752 | unsigned int | |
4753 | lin_thread_get_thread_signal_num (void) | |
d6b0e80f | 4754 | { |
089436f7 TV |
4755 | return sizeof (lin_thread_signals) / sizeof (lin_thread_signals[0]); |
4756 | } | |
d6b0e80f | 4757 | |
089436f7 TV |
4758 | /* See linux-nat.h. */ |
4759 | ||
4760 | int | |
4761 | lin_thread_get_thread_signal (unsigned int i) | |
4762 | { | |
4763 | gdb_assert (i < lin_thread_get_thread_signal_num ()); | |
4764 | return lin_thread_signals[i]; | |
d6b0e80f | 4765 | } |