Commit | Line | Data |
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3993f6b1 | 1 | /* GNU/Linux native-dependent code common to multiple platforms. |
dba24537 | 2 | |
b811d2c2 | 3 | Copyright (C) 2001-2020 Free Software Foundation, Inc. |
3993f6b1 DJ |
4 | |
5 | This file is part of GDB. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
a9762ec7 | 9 | the Free Software Foundation; either version 3 of the License, or |
3993f6b1 DJ |
10 | (at your option) any later version. |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
a9762ec7 | 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
3993f6b1 DJ |
19 | |
20 | #include "defs.h" | |
21 | #include "inferior.h" | |
45741a9c | 22 | #include "infrun.h" |
3993f6b1 | 23 | #include "target.h" |
96d7229d LM |
24 | #include "nat/linux-nat.h" |
25 | #include "nat/linux-waitpid.h" | |
268a13a5 | 26 | #include "gdbsupport/gdb_wait.h" |
d6b0e80f AC |
27 | #include <unistd.h> |
28 | #include <sys/syscall.h> | |
5826e159 | 29 | #include "nat/gdb_ptrace.h" |
0274a8ce | 30 | #include "linux-nat.h" |
125f8a3d GB |
31 | #include "nat/linux-ptrace.h" |
32 | #include "nat/linux-procfs.h" | |
8cc73a39 | 33 | #include "nat/linux-personality.h" |
ac264b3b | 34 | #include "linux-fork.h" |
d6b0e80f AC |
35 | #include "gdbthread.h" |
36 | #include "gdbcmd.h" | |
37 | #include "regcache.h" | |
4f844a66 | 38 | #include "regset.h" |
dab06dbe | 39 | #include "inf-child.h" |
10d6c8cd DJ |
40 | #include "inf-ptrace.h" |
41 | #include "auxv.h" | |
1777feb0 | 42 | #include <sys/procfs.h> /* for elf_gregset etc. */ |
dba24537 AC |
43 | #include "elf-bfd.h" /* for elfcore_write_* */ |
44 | #include "gregset.h" /* for gregset */ | |
45 | #include "gdbcore.h" /* for get_exec_file */ | |
46 | #include <ctype.h> /* for isdigit */ | |
53ce3c39 | 47 | #include <sys/stat.h> /* for struct stat */ |
dba24537 | 48 | #include <fcntl.h> /* for O_RDONLY */ |
b84876c2 | 49 | #include "inf-loop.h" |
400b5eca | 50 | #include "gdbsupport/event-loop.h" |
b84876c2 | 51 | #include "event-top.h" |
07e059b5 VP |
52 | #include <pwd.h> |
53 | #include <sys/types.h> | |
2978b111 | 54 | #include <dirent.h> |
07e059b5 | 55 | #include "xml-support.h" |
efcbbd14 | 56 | #include <sys/vfs.h> |
6c95b8df | 57 | #include "solib.h" |
125f8a3d | 58 | #include "nat/linux-osdata.h" |
6432734d | 59 | #include "linux-tdep.h" |
7dcd53a0 | 60 | #include "symfile.h" |
268a13a5 | 61 | #include "gdbsupport/agent.h" |
5808517f | 62 | #include "tracepoint.h" |
268a13a5 | 63 | #include "gdbsupport/buffer.h" |
6ecd4729 | 64 | #include "target-descriptions.h" |
268a13a5 | 65 | #include "gdbsupport/filestuff.h" |
77e371c0 | 66 | #include "objfiles.h" |
7a6a1731 | 67 | #include "nat/linux-namespaces.h" |
268a13a5 TT |
68 | #include "gdbsupport/fileio.h" |
69 | #include "gdbsupport/scope-exit.h" | |
21987b9c | 70 | #include "gdbsupport/gdb-sigmask.h" |
ba988419 | 71 | #include "gdbsupport/common-debug.h" |
efcbbd14 | 72 | |
1777feb0 | 73 | /* This comment documents high-level logic of this file. |
8a77dff3 VP |
74 | |
75 | Waiting for events in sync mode | |
76 | =============================== | |
77 | ||
4a6ed09b PA |
78 | When waiting for an event in a specific thread, we just use waitpid, |
79 | passing the specific pid, and not passing WNOHANG. | |
80 | ||
81 | When waiting for an event in all threads, waitpid is not quite good: | |
82 | ||
83 | - If the thread group leader exits while other threads in the thread | |
84 | group still exist, waitpid(TGID, ...) hangs. That waitpid won't | |
85 | return an exit status until the other threads in the group are | |
86 | reaped. | |
87 | ||
88 | - When a non-leader thread execs, that thread just vanishes without | |
89 | reporting an exit (so we'd hang if we waited for it explicitly in | |
90 | that case). The exec event is instead reported to the TGID pid. | |
91 | ||
92 | The solution is to always use -1 and WNOHANG, together with | |
93 | sigsuspend. | |
94 | ||
95 | First, we use non-blocking waitpid to check for events. If nothing is | |
96 | found, we use sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, | |
97 | it means something happened to a child process. As soon as we know | |
98 | there's an event, we get back to calling nonblocking waitpid. | |
99 | ||
100 | Note that SIGCHLD should be blocked between waitpid and sigsuspend | |
101 | calls, so that we don't miss a signal. If SIGCHLD arrives in between, | |
102 | when it's blocked, the signal becomes pending and sigsuspend | |
103 | immediately notices it and returns. | |
104 | ||
105 | Waiting for events in async mode (TARGET_WNOHANG) | |
106 | ================================================= | |
8a77dff3 | 107 | |
7feb7d06 PA |
108 | In async mode, GDB should always be ready to handle both user input |
109 | and target events, so neither blocking waitpid nor sigsuspend are | |
110 | viable options. Instead, we should asynchronously notify the GDB main | |
111 | event loop whenever there's an unprocessed event from the target. We | |
112 | detect asynchronous target events by handling SIGCHLD signals. To | |
113 | notify the event loop about target events, the self-pipe trick is used | |
114 | --- a pipe is registered as waitable event source in the event loop, | |
115 | the event loop select/poll's on the read end of this pipe (as well on | |
116 | other event sources, e.g., stdin), and the SIGCHLD handler writes a | |
117 | byte to this pipe. This is more portable than relying on | |
118 | pselect/ppoll, since on kernels that lack those syscalls, libc | |
119 | emulates them with select/poll+sigprocmask, and that is racy | |
120 | (a.k.a. plain broken). | |
121 | ||
122 | Obviously, if we fail to notify the event loop if there's a target | |
123 | event, it's bad. OTOH, if we notify the event loop when there's no | |
124 | event from the target, linux_nat_wait will detect that there's no real | |
125 | event to report, and return event of type TARGET_WAITKIND_IGNORE. | |
126 | This is mostly harmless, but it will waste time and is better avoided. | |
127 | ||
128 | The main design point is that every time GDB is outside linux-nat.c, | |
129 | we have a SIGCHLD handler installed that is called when something | |
130 | happens to the target and notifies the GDB event loop. Whenever GDB | |
131 | core decides to handle the event, and calls into linux-nat.c, we | |
132 | process things as in sync mode, except that the we never block in | |
133 | sigsuspend. | |
134 | ||
135 | While processing an event, we may end up momentarily blocked in | |
136 | waitpid calls. Those waitpid calls, while blocking, are guarantied to | |
137 | return quickly. E.g., in all-stop mode, before reporting to the core | |
138 | that an LWP hit a breakpoint, all LWPs are stopped by sending them | |
139 | SIGSTOP, and synchronously waiting for the SIGSTOP to be reported. | |
140 | Note that this is different from blocking indefinitely waiting for the | |
141 | next event --- here, we're already handling an event. | |
8a77dff3 VP |
142 | |
143 | Use of signals | |
144 | ============== | |
145 | ||
146 | We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another | |
147 | signal is not entirely significant; we just need for a signal to be delivered, | |
148 | so that we can intercept it. SIGSTOP's advantage is that it can not be | |
149 | blocked. A disadvantage is that it is not a real-time signal, so it can only | |
150 | be queued once; we do not keep track of other sources of SIGSTOP. | |
151 | ||
152 | Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't | |
153 | use them, because they have special behavior when the signal is generated - | |
154 | not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL | |
155 | kills the entire thread group. | |
156 | ||
157 | A delivered SIGSTOP would stop the entire thread group, not just the thread we | |
158 | tkill'd. But we never let the SIGSTOP be delivered; we always intercept and | |
159 | cancel it (by PTRACE_CONT without passing SIGSTOP). | |
160 | ||
161 | We could use a real-time signal instead. This would solve those problems; we | |
162 | could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB. | |
163 | But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH | |
164 | generates it, and there are races with trying to find a signal that is not | |
4a6ed09b PA |
165 | blocked. |
166 | ||
167 | Exec events | |
168 | =========== | |
169 | ||
170 | The case of a thread group (process) with 3 or more threads, and a | |
171 | thread other than the leader execs is worth detailing: | |
172 | ||
173 | On an exec, the Linux kernel destroys all threads except the execing | |
174 | one in the thread group, and resets the execing thread's tid to the | |
175 | tgid. No exit notification is sent for the execing thread -- from the | |
176 | ptracer's perspective, it appears as though the execing thread just | |
177 | vanishes. Until we reap all other threads except the leader and the | |
178 | execing thread, the leader will be zombie, and the execing thread will | |
179 | be in `D (disc sleep)' state. As soon as all other threads are | |
180 | reaped, the execing thread changes its tid to the tgid, and the | |
181 | previous (zombie) leader vanishes, giving place to the "new" | |
182 | leader. */ | |
a0ef4274 | 183 | |
dba24537 AC |
184 | #ifndef O_LARGEFILE |
185 | #define O_LARGEFILE 0 | |
186 | #endif | |
0274a8ce | 187 | |
f6ac5f3d PA |
188 | struct linux_nat_target *linux_target; |
189 | ||
433bbbf8 | 190 | /* Does the current host support PTRACE_GETREGSET? */ |
0bdb2f78 | 191 | enum tribool have_ptrace_getregset = TRIBOOL_UNKNOWN; |
433bbbf8 | 192 | |
ccce17b0 | 193 | static unsigned int debug_linux_nat; |
920d2a44 AC |
194 | static void |
195 | show_debug_linux_nat (struct ui_file *file, int from_tty, | |
196 | struct cmd_list_element *c, const char *value) | |
197 | { | |
198 | fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"), | |
199 | value); | |
200 | } | |
d6b0e80f | 201 | |
9327494e SM |
202 | /* Print a debug statement. Should be used through linux_nat_debug_printf. */ |
203 | ||
204 | static void ATTRIBUTE_PRINTF (2, 3) | |
205 | linux_nat_debug_printf_1 (const char *func_name, const char *fmt, ...) | |
206 | { | |
9327494e SM |
207 | va_list ap; |
208 | va_start (ap, fmt); | |
c426fddb | 209 | debug_prefixed_vprintf ("linux-nat", func_name, fmt, ap); |
9327494e | 210 | va_end (ap); |
9327494e SM |
211 | } |
212 | ||
213 | #define linux_nat_debug_printf(fmt, ...) \ | |
956bdb59 SM |
214 | do \ |
215 | { \ | |
216 | if (debug_linux_nat) \ | |
217 | linux_nat_debug_printf_1 (__func__, fmt, ##__VA_ARGS__); \ | |
218 | } \ | |
219 | while (0) | |
9327494e | 220 | |
ae087d01 DJ |
221 | struct simple_pid_list |
222 | { | |
223 | int pid; | |
3d799a95 | 224 | int status; |
ae087d01 DJ |
225 | struct simple_pid_list *next; |
226 | }; | |
05c309a8 | 227 | static struct simple_pid_list *stopped_pids; |
ae087d01 | 228 | |
aa01bd36 PA |
229 | /* Whether target_thread_events is in effect. */ |
230 | static int report_thread_events; | |
231 | ||
3dd5b83d PA |
232 | /* Async mode support. */ |
233 | ||
b84876c2 PA |
234 | /* The read/write ends of the pipe registered as waitable file in the |
235 | event loop. */ | |
236 | static int linux_nat_event_pipe[2] = { -1, -1 }; | |
237 | ||
198297aa PA |
238 | /* True if we're currently in async mode. */ |
239 | #define linux_is_async_p() (linux_nat_event_pipe[0] != -1) | |
240 | ||
7feb7d06 | 241 | /* Flush the event pipe. */ |
b84876c2 | 242 | |
7feb7d06 PA |
243 | static void |
244 | async_file_flush (void) | |
b84876c2 | 245 | { |
7feb7d06 PA |
246 | int ret; |
247 | char buf; | |
b84876c2 | 248 | |
7feb7d06 | 249 | do |
b84876c2 | 250 | { |
7feb7d06 | 251 | ret = read (linux_nat_event_pipe[0], &buf, 1); |
b84876c2 | 252 | } |
7feb7d06 | 253 | while (ret >= 0 || (ret == -1 && errno == EINTR)); |
b84876c2 PA |
254 | } |
255 | ||
7feb7d06 PA |
256 | /* Put something (anything, doesn't matter what, or how much) in event |
257 | pipe, so that the select/poll in the event-loop realizes we have | |
258 | something to process. */ | |
252fbfc8 | 259 | |
b84876c2 | 260 | static void |
7feb7d06 | 261 | async_file_mark (void) |
b84876c2 | 262 | { |
7feb7d06 | 263 | int ret; |
b84876c2 | 264 | |
7feb7d06 PA |
265 | /* It doesn't really matter what the pipe contains, as long we end |
266 | up with something in it. Might as well flush the previous | |
267 | left-overs. */ | |
268 | async_file_flush (); | |
b84876c2 | 269 | |
7feb7d06 | 270 | do |
b84876c2 | 271 | { |
7feb7d06 | 272 | ret = write (linux_nat_event_pipe[1], "+", 1); |
b84876c2 | 273 | } |
7feb7d06 | 274 | while (ret == -1 && errno == EINTR); |
b84876c2 | 275 | |
7feb7d06 PA |
276 | /* Ignore EAGAIN. If the pipe is full, the event loop will already |
277 | be awakened anyway. */ | |
b84876c2 PA |
278 | } |
279 | ||
7feb7d06 PA |
280 | static int kill_lwp (int lwpid, int signo); |
281 | ||
d3a70e03 | 282 | static int stop_callback (struct lwp_info *lp); |
7feb7d06 PA |
283 | |
284 | static void block_child_signals (sigset_t *prev_mask); | |
285 | static void restore_child_signals_mask (sigset_t *prev_mask); | |
2277426b PA |
286 | |
287 | struct lwp_info; | |
288 | static struct lwp_info *add_lwp (ptid_t ptid); | |
289 | static void purge_lwp_list (int pid); | |
4403d8e9 | 290 | static void delete_lwp (ptid_t ptid); |
2277426b PA |
291 | static struct lwp_info *find_lwp_pid (ptid_t ptid); |
292 | ||
8a99810d PA |
293 | static int lwp_status_pending_p (struct lwp_info *lp); |
294 | ||
e7ad2f14 PA |
295 | static void save_stop_reason (struct lwp_info *lp); |
296 | ||
cff068da GB |
297 | \f |
298 | /* LWP accessors. */ | |
299 | ||
300 | /* See nat/linux-nat.h. */ | |
301 | ||
302 | ptid_t | |
303 | ptid_of_lwp (struct lwp_info *lwp) | |
304 | { | |
305 | return lwp->ptid; | |
306 | } | |
307 | ||
308 | /* See nat/linux-nat.h. */ | |
309 | ||
4b134ca1 GB |
310 | void |
311 | lwp_set_arch_private_info (struct lwp_info *lwp, | |
312 | struct arch_lwp_info *info) | |
313 | { | |
314 | lwp->arch_private = info; | |
315 | } | |
316 | ||
317 | /* See nat/linux-nat.h. */ | |
318 | ||
319 | struct arch_lwp_info * | |
320 | lwp_arch_private_info (struct lwp_info *lwp) | |
321 | { | |
322 | return lwp->arch_private; | |
323 | } | |
324 | ||
325 | /* See nat/linux-nat.h. */ | |
326 | ||
cff068da GB |
327 | int |
328 | lwp_is_stopped (struct lwp_info *lwp) | |
329 | { | |
330 | return lwp->stopped; | |
331 | } | |
332 | ||
333 | /* See nat/linux-nat.h. */ | |
334 | ||
335 | enum target_stop_reason | |
336 | lwp_stop_reason (struct lwp_info *lwp) | |
337 | { | |
338 | return lwp->stop_reason; | |
339 | } | |
340 | ||
0e00e962 AA |
341 | /* See nat/linux-nat.h. */ |
342 | ||
343 | int | |
344 | lwp_is_stepping (struct lwp_info *lwp) | |
345 | { | |
346 | return lwp->step; | |
347 | } | |
348 | ||
ae087d01 DJ |
349 | \f |
350 | /* Trivial list manipulation functions to keep track of a list of | |
351 | new stopped processes. */ | |
352 | static void | |
3d799a95 | 353 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
ae087d01 | 354 | { |
8d749320 | 355 | struct simple_pid_list *new_pid = XNEW (struct simple_pid_list); |
e0881a8e | 356 | |
ae087d01 | 357 | new_pid->pid = pid; |
3d799a95 | 358 | new_pid->status = status; |
ae087d01 DJ |
359 | new_pid->next = *listp; |
360 | *listp = new_pid; | |
361 | } | |
362 | ||
363 | static int | |
46a96992 | 364 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
ae087d01 DJ |
365 | { |
366 | struct simple_pid_list **p; | |
367 | ||
368 | for (p = listp; *p != NULL; p = &(*p)->next) | |
369 | if ((*p)->pid == pid) | |
370 | { | |
371 | struct simple_pid_list *next = (*p)->next; | |
e0881a8e | 372 | |
46a96992 | 373 | *statusp = (*p)->status; |
ae087d01 DJ |
374 | xfree (*p); |
375 | *p = next; | |
376 | return 1; | |
377 | } | |
378 | return 0; | |
379 | } | |
380 | ||
de0d863e DB |
381 | /* Return the ptrace options that we want to try to enable. */ |
382 | ||
383 | static int | |
384 | linux_nat_ptrace_options (int attached) | |
385 | { | |
386 | int options = 0; | |
387 | ||
388 | if (!attached) | |
389 | options |= PTRACE_O_EXITKILL; | |
390 | ||
391 | options |= (PTRACE_O_TRACESYSGOOD | |
392 | | PTRACE_O_TRACEVFORKDONE | |
393 | | PTRACE_O_TRACEVFORK | |
394 | | PTRACE_O_TRACEFORK | |
395 | | PTRACE_O_TRACEEXEC); | |
396 | ||
397 | return options; | |
398 | } | |
399 | ||
1b919490 VB |
400 | /* Initialize ptrace and procfs warnings and check for supported |
401 | ptrace features given PID. | |
beed38b8 JB |
402 | |
403 | ATTACHED should be nonzero iff we attached to the inferior. */ | |
3993f6b1 DJ |
404 | |
405 | static void | |
1b919490 | 406 | linux_init_ptrace_procfs (pid_t pid, int attached) |
3993f6b1 | 407 | { |
de0d863e DB |
408 | int options = linux_nat_ptrace_options (attached); |
409 | ||
410 | linux_enable_event_reporting (pid, options); | |
96d7229d | 411 | linux_ptrace_init_warnings (); |
1b919490 | 412 | linux_proc_init_warnings (); |
4de4c07c DJ |
413 | } |
414 | ||
f6ac5f3d PA |
415 | linux_nat_target::~linux_nat_target () |
416 | {} | |
417 | ||
418 | void | |
419 | linux_nat_target::post_attach (int pid) | |
4de4c07c | 420 | { |
1b919490 | 421 | linux_init_ptrace_procfs (pid, 1); |
4de4c07c DJ |
422 | } |
423 | ||
f6ac5f3d PA |
424 | void |
425 | linux_nat_target::post_startup_inferior (ptid_t ptid) | |
4de4c07c | 426 | { |
1b919490 | 427 | linux_init_ptrace_procfs (ptid.pid (), 0); |
4de4c07c DJ |
428 | } |
429 | ||
4403d8e9 JK |
430 | /* Return the number of known LWPs in the tgid given by PID. */ |
431 | ||
432 | static int | |
433 | num_lwps (int pid) | |
434 | { | |
435 | int count = 0; | |
436 | struct lwp_info *lp; | |
437 | ||
438 | for (lp = lwp_list; lp; lp = lp->next) | |
e99b03dc | 439 | if (lp->ptid.pid () == pid) |
4403d8e9 JK |
440 | count++; |
441 | ||
442 | return count; | |
443 | } | |
444 | ||
169bb27b | 445 | /* Deleter for lwp_info unique_ptr specialisation. */ |
4403d8e9 | 446 | |
169bb27b | 447 | struct lwp_deleter |
4403d8e9 | 448 | { |
169bb27b AB |
449 | void operator() (struct lwp_info *lwp) const |
450 | { | |
451 | delete_lwp (lwp->ptid); | |
452 | } | |
453 | }; | |
4403d8e9 | 454 | |
169bb27b AB |
455 | /* A unique_ptr specialisation for lwp_info. */ |
456 | ||
457 | typedef std::unique_ptr<struct lwp_info, lwp_deleter> lwp_info_up; | |
4403d8e9 | 458 | |
d83ad864 DB |
459 | /* Target hook for follow_fork. On entry inferior_ptid must be the |
460 | ptid of the followed inferior. At return, inferior_ptid will be | |
461 | unchanged. */ | |
462 | ||
5ab2fbf1 SM |
463 | bool |
464 | linux_nat_target::follow_fork (bool follow_child, bool detach_fork) | |
3993f6b1 | 465 | { |
d83ad864 | 466 | if (!follow_child) |
4de4c07c | 467 | { |
6c95b8df | 468 | struct lwp_info *child_lp = NULL; |
d83ad864 | 469 | int has_vforked; |
79639e11 | 470 | ptid_t parent_ptid, child_ptid; |
d83ad864 DB |
471 | int parent_pid, child_pid; |
472 | ||
473 | has_vforked = (inferior_thread ()->pending_follow.kind | |
474 | == TARGET_WAITKIND_VFORKED); | |
79639e11 PA |
475 | parent_ptid = inferior_ptid; |
476 | child_ptid = inferior_thread ()->pending_follow.value.related_pid; | |
e38504b3 TT |
477 | parent_pid = parent_ptid.lwp (); |
478 | child_pid = child_ptid.lwp (); | |
4de4c07c | 479 | |
1777feb0 | 480 | /* We're already attached to the parent, by default. */ |
2989a365 | 481 | child_lp = add_lwp (child_ptid); |
d83ad864 DB |
482 | child_lp->stopped = 1; |
483 | child_lp->last_resume_kind = resume_stop; | |
4de4c07c | 484 | |
ac264b3b MS |
485 | /* Detach new forked process? */ |
486 | if (detach_fork) | |
f75c00e4 | 487 | { |
95347337 AB |
488 | int child_stop_signal = 0; |
489 | bool detach_child = true; | |
4403d8e9 | 490 | |
169bb27b AB |
491 | /* Move CHILD_LP into a unique_ptr and clear the source pointer |
492 | to prevent us doing anything stupid with it. */ | |
493 | lwp_info_up child_lp_ptr (child_lp); | |
494 | child_lp = nullptr; | |
495 | ||
496 | linux_target->low_prepare_to_resume (child_lp_ptr.get ()); | |
c077881a HZ |
497 | |
498 | /* When debugging an inferior in an architecture that supports | |
499 | hardware single stepping on a kernel without commit | |
500 | 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child | |
501 | process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits | |
502 | set if the parent process had them set. | |
503 | To work around this, single step the child process | |
504 | once before detaching to clear the flags. */ | |
505 | ||
2fd9d7ca PA |
506 | /* Note that we consult the parent's architecture instead of |
507 | the child's because there's no inferior for the child at | |
508 | this point. */ | |
c077881a | 509 | if (!gdbarch_software_single_step_p (target_thread_architecture |
2fd9d7ca | 510 | (parent_ptid))) |
c077881a | 511 | { |
95347337 AB |
512 | int status; |
513 | ||
c077881a HZ |
514 | linux_disable_event_reporting (child_pid); |
515 | if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0) | |
516 | perror_with_name (_("Couldn't do single step")); | |
517 | if (my_waitpid (child_pid, &status, 0) < 0) | |
518 | perror_with_name (_("Couldn't wait vfork process")); | |
95347337 AB |
519 | else |
520 | { | |
521 | detach_child = WIFSTOPPED (status); | |
522 | child_stop_signal = WSTOPSIG (status); | |
523 | } | |
c077881a HZ |
524 | } |
525 | ||
95347337 | 526 | if (detach_child) |
9caaaa83 | 527 | { |
95347337 | 528 | int signo = child_stop_signal; |
9caaaa83 | 529 | |
9caaaa83 PA |
530 | if (signo != 0 |
531 | && !signal_pass_state (gdb_signal_from_host (signo))) | |
532 | signo = 0; | |
533 | ptrace (PTRACE_DETACH, child_pid, 0, signo); | |
534 | } | |
ac264b3b MS |
535 | } |
536 | else | |
537 | { | |
5b6d1e4f PA |
538 | /* Switching inferior_ptid is not enough, because then |
539 | inferior_thread () would crash by not finding the thread | |
540 | in the current inferior. */ | |
541 | scoped_restore_current_thread restore_current_thread; | |
542 | thread_info *child = find_thread_ptid (this, child_ptid); | |
543 | switch_to_thread (child); | |
2989a365 | 544 | |
6c95b8df | 545 | /* Let the thread_db layer learn about this new process. */ |
2277426b | 546 | check_for_thread_db (); |
ac264b3b | 547 | } |
9016a515 DJ |
548 | |
549 | if (has_vforked) | |
550 | { | |
3ced3da4 | 551 | struct lwp_info *parent_lp; |
6c95b8df | 552 | |
79639e11 | 553 | parent_lp = find_lwp_pid (parent_ptid); |
96d7229d | 554 | gdb_assert (linux_supports_tracefork () >= 0); |
3ced3da4 | 555 | |
96d7229d | 556 | if (linux_supports_tracevforkdone ()) |
9016a515 | 557 | { |
9327494e SM |
558 | linux_nat_debug_printf ("waiting for VFORK_DONE on %d", |
559 | parent_pid); | |
3ced3da4 | 560 | parent_lp->stopped = 1; |
9016a515 | 561 | |
6c95b8df PA |
562 | /* We'll handle the VFORK_DONE event like any other |
563 | event, in target_wait. */ | |
9016a515 DJ |
564 | } |
565 | else | |
566 | { | |
567 | /* We can't insert breakpoints until the child has | |
568 | finished with the shared memory region. We need to | |
569 | wait until that happens. Ideal would be to just | |
570 | call: | |
571 | - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0); | |
572 | - waitpid (parent_pid, &status, __WALL); | |
573 | However, most architectures can't handle a syscall | |
574 | being traced on the way out if it wasn't traced on | |
575 | the way in. | |
576 | ||
577 | We might also think to loop, continuing the child | |
578 | until it exits or gets a SIGTRAP. One problem is | |
579 | that the child might call ptrace with PTRACE_TRACEME. | |
580 | ||
581 | There's no simple and reliable way to figure out when | |
582 | the vforked child will be done with its copy of the | |
583 | shared memory. We could step it out of the syscall, | |
584 | two instructions, let it go, and then single-step the | |
585 | parent once. When we have hardware single-step, this | |
586 | would work; with software single-step it could still | |
587 | be made to work but we'd have to be able to insert | |
588 | single-step breakpoints in the child, and we'd have | |
589 | to insert -just- the single-step breakpoint in the | |
590 | parent. Very awkward. | |
591 | ||
592 | In the end, the best we can do is to make sure it | |
593 | runs for a little while. Hopefully it will be out of | |
594 | range of any breakpoints we reinsert. Usually this | |
595 | is only the single-step breakpoint at vfork's return | |
596 | point. */ | |
597 | ||
9327494e | 598 | linux_nat_debug_printf ("no VFORK_DONE support, sleeping a bit"); |
6c95b8df | 599 | |
9016a515 | 600 | usleep (10000); |
9016a515 | 601 | |
6c95b8df PA |
602 | /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event, |
603 | and leave it pending. The next linux_nat_resume call | |
604 | will notice a pending event, and bypasses actually | |
605 | resuming the inferior. */ | |
3ced3da4 PA |
606 | parent_lp->status = 0; |
607 | parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE; | |
608 | parent_lp->stopped = 1; | |
6c95b8df PA |
609 | |
610 | /* If we're in async mode, need to tell the event loop | |
611 | there's something here to process. */ | |
d9d41e78 | 612 | if (target_is_async_p ()) |
6c95b8df PA |
613 | async_file_mark (); |
614 | } | |
9016a515 | 615 | } |
4de4c07c | 616 | } |
3993f6b1 | 617 | else |
4de4c07c | 618 | { |
3ced3da4 | 619 | struct lwp_info *child_lp; |
4de4c07c | 620 | |
3ced3da4 PA |
621 | child_lp = add_lwp (inferior_ptid); |
622 | child_lp->stopped = 1; | |
25289eb2 | 623 | child_lp->last_resume_kind = resume_stop; |
6c95b8df | 624 | |
6c95b8df | 625 | /* Let the thread_db layer learn about this new process. */ |
ef29ce1a | 626 | check_for_thread_db (); |
4de4c07c DJ |
627 | } |
628 | ||
5ab2fbf1 | 629 | return false; |
4de4c07c DJ |
630 | } |
631 | ||
4de4c07c | 632 | \f |
f6ac5f3d PA |
633 | int |
634 | linux_nat_target::insert_fork_catchpoint (int pid) | |
4de4c07c | 635 | { |
96d7229d | 636 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
637 | } |
638 | ||
f6ac5f3d PA |
639 | int |
640 | linux_nat_target::remove_fork_catchpoint (int pid) | |
eb73ad13 PA |
641 | { |
642 | return 0; | |
643 | } | |
644 | ||
f6ac5f3d PA |
645 | int |
646 | linux_nat_target::insert_vfork_catchpoint (int pid) | |
3993f6b1 | 647 | { |
96d7229d | 648 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
649 | } |
650 | ||
f6ac5f3d PA |
651 | int |
652 | linux_nat_target::remove_vfork_catchpoint (int pid) | |
eb73ad13 PA |
653 | { |
654 | return 0; | |
655 | } | |
656 | ||
f6ac5f3d PA |
657 | int |
658 | linux_nat_target::insert_exec_catchpoint (int pid) | |
3993f6b1 | 659 | { |
96d7229d | 660 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
661 | } |
662 | ||
f6ac5f3d PA |
663 | int |
664 | linux_nat_target::remove_exec_catchpoint (int pid) | |
eb73ad13 PA |
665 | { |
666 | return 0; | |
667 | } | |
668 | ||
f6ac5f3d PA |
669 | int |
670 | linux_nat_target::set_syscall_catchpoint (int pid, bool needed, int any_count, | |
671 | gdb::array_view<const int> syscall_counts) | |
a96d9b2e | 672 | { |
96d7229d | 673 | if (!linux_supports_tracesysgood ()) |
77b06cd7 TJB |
674 | return 1; |
675 | ||
a96d9b2e SDJ |
676 | /* On GNU/Linux, we ignore the arguments. It means that we only |
677 | enable the syscall catchpoints, but do not disable them. | |
77b06cd7 | 678 | |
649a140c | 679 | Also, we do not use the `syscall_counts' information because we do not |
a96d9b2e SDJ |
680 | filter system calls here. We let GDB do the logic for us. */ |
681 | return 0; | |
682 | } | |
683 | ||
774113b0 PA |
684 | /* List of known LWPs, keyed by LWP PID. This speeds up the common |
685 | case of mapping a PID returned from the kernel to our corresponding | |
686 | lwp_info data structure. */ | |
687 | static htab_t lwp_lwpid_htab; | |
688 | ||
689 | /* Calculate a hash from a lwp_info's LWP PID. */ | |
690 | ||
691 | static hashval_t | |
692 | lwp_info_hash (const void *ap) | |
693 | { | |
694 | const struct lwp_info *lp = (struct lwp_info *) ap; | |
e38504b3 | 695 | pid_t pid = lp->ptid.lwp (); |
774113b0 PA |
696 | |
697 | return iterative_hash_object (pid, 0); | |
698 | } | |
699 | ||
700 | /* Equality function for the lwp_info hash table. Compares the LWP's | |
701 | PID. */ | |
702 | ||
703 | static int | |
704 | lwp_lwpid_htab_eq (const void *a, const void *b) | |
705 | { | |
706 | const struct lwp_info *entry = (const struct lwp_info *) a; | |
707 | const struct lwp_info *element = (const struct lwp_info *) b; | |
708 | ||
e38504b3 | 709 | return entry->ptid.lwp () == element->ptid.lwp (); |
774113b0 PA |
710 | } |
711 | ||
712 | /* Create the lwp_lwpid_htab hash table. */ | |
713 | ||
714 | static void | |
715 | lwp_lwpid_htab_create (void) | |
716 | { | |
717 | lwp_lwpid_htab = htab_create (100, lwp_info_hash, lwp_lwpid_htab_eq, NULL); | |
718 | } | |
719 | ||
720 | /* Add LP to the hash table. */ | |
721 | ||
722 | static void | |
723 | lwp_lwpid_htab_add_lwp (struct lwp_info *lp) | |
724 | { | |
725 | void **slot; | |
726 | ||
727 | slot = htab_find_slot (lwp_lwpid_htab, lp, INSERT); | |
728 | gdb_assert (slot != NULL && *slot == NULL); | |
729 | *slot = lp; | |
730 | } | |
731 | ||
732 | /* Head of doubly-linked list of known LWPs. Sorted by reverse | |
733 | creation order. This order is assumed in some cases. E.g., | |
734 | reaping status after killing alls lwps of a process: the leader LWP | |
735 | must be reaped last. */ | |
9f0bdab8 | 736 | struct lwp_info *lwp_list; |
774113b0 PA |
737 | |
738 | /* Add LP to sorted-by-reverse-creation-order doubly-linked list. */ | |
739 | ||
740 | static void | |
741 | lwp_list_add (struct lwp_info *lp) | |
742 | { | |
743 | lp->next = lwp_list; | |
744 | if (lwp_list != NULL) | |
745 | lwp_list->prev = lp; | |
746 | lwp_list = lp; | |
747 | } | |
748 | ||
749 | /* Remove LP from sorted-by-reverse-creation-order doubly-linked | |
750 | list. */ | |
751 | ||
752 | static void | |
753 | lwp_list_remove (struct lwp_info *lp) | |
754 | { | |
755 | /* Remove from sorted-by-creation-order list. */ | |
756 | if (lp->next != NULL) | |
757 | lp->next->prev = lp->prev; | |
758 | if (lp->prev != NULL) | |
759 | lp->prev->next = lp->next; | |
760 | if (lp == lwp_list) | |
761 | lwp_list = lp->next; | |
762 | } | |
763 | ||
d6b0e80f AC |
764 | \f |
765 | ||
d6b0e80f AC |
766 | /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in |
767 | _initialize_linux_nat. */ | |
768 | static sigset_t suspend_mask; | |
769 | ||
7feb7d06 PA |
770 | /* Signals to block to make that sigsuspend work. */ |
771 | static sigset_t blocked_mask; | |
772 | ||
773 | /* SIGCHLD action. */ | |
774 | struct sigaction sigchld_action; | |
b84876c2 | 775 | |
7feb7d06 PA |
776 | /* Block child signals (SIGCHLD and linux threads signals), and store |
777 | the previous mask in PREV_MASK. */ | |
84e46146 | 778 | |
7feb7d06 PA |
779 | static void |
780 | block_child_signals (sigset_t *prev_mask) | |
781 | { | |
782 | /* Make sure SIGCHLD is blocked. */ | |
783 | if (!sigismember (&blocked_mask, SIGCHLD)) | |
784 | sigaddset (&blocked_mask, SIGCHLD); | |
785 | ||
21987b9c | 786 | gdb_sigmask (SIG_BLOCK, &blocked_mask, prev_mask); |
7feb7d06 PA |
787 | } |
788 | ||
789 | /* Restore child signals mask, previously returned by | |
790 | block_child_signals. */ | |
791 | ||
792 | static void | |
793 | restore_child_signals_mask (sigset_t *prev_mask) | |
794 | { | |
21987b9c | 795 | gdb_sigmask (SIG_SETMASK, prev_mask, NULL); |
7feb7d06 | 796 | } |
2455069d UW |
797 | |
798 | /* Mask of signals to pass directly to the inferior. */ | |
799 | static sigset_t pass_mask; | |
800 | ||
801 | /* Update signals to pass to the inferior. */ | |
f6ac5f3d | 802 | void |
adc6a863 PA |
803 | linux_nat_target::pass_signals |
804 | (gdb::array_view<const unsigned char> pass_signals) | |
2455069d UW |
805 | { |
806 | int signo; | |
807 | ||
808 | sigemptyset (&pass_mask); | |
809 | ||
810 | for (signo = 1; signo < NSIG; signo++) | |
811 | { | |
2ea28649 | 812 | int target_signo = gdb_signal_from_host (signo); |
adc6a863 | 813 | if (target_signo < pass_signals.size () && pass_signals[target_signo]) |
2455069d UW |
814 | sigaddset (&pass_mask, signo); |
815 | } | |
816 | } | |
817 | ||
d6b0e80f AC |
818 | \f |
819 | ||
820 | /* Prototypes for local functions. */ | |
d3a70e03 TT |
821 | static int stop_wait_callback (struct lwp_info *lp); |
822 | static int resume_stopped_resumed_lwps (struct lwp_info *lp, const ptid_t wait_ptid); | |
ced2dffb | 823 | static int check_ptrace_stopped_lwp_gone (struct lwp_info *lp); |
710151dd | 824 | |
d6b0e80f | 825 | \f |
d6b0e80f | 826 | |
7b50312a PA |
827 | /* Destroy and free LP. */ |
828 | ||
829 | static void | |
830 | lwp_free (struct lwp_info *lp) | |
831 | { | |
466eecee | 832 | /* Let the arch specific bits release arch_lwp_info. */ |
135340af | 833 | linux_target->low_delete_thread (lp->arch_private); |
466eecee | 834 | |
7b50312a PA |
835 | xfree (lp); |
836 | } | |
837 | ||
774113b0 | 838 | /* Traversal function for purge_lwp_list. */ |
d90e17a7 | 839 | |
774113b0 PA |
840 | static int |
841 | lwp_lwpid_htab_remove_pid (void **slot, void *info) | |
d90e17a7 | 842 | { |
774113b0 PA |
843 | struct lwp_info *lp = (struct lwp_info *) *slot; |
844 | int pid = *(int *) info; | |
d90e17a7 | 845 | |
e99b03dc | 846 | if (lp->ptid.pid () == pid) |
d90e17a7 | 847 | { |
774113b0 PA |
848 | htab_clear_slot (lwp_lwpid_htab, slot); |
849 | lwp_list_remove (lp); | |
850 | lwp_free (lp); | |
851 | } | |
d90e17a7 | 852 | |
774113b0 PA |
853 | return 1; |
854 | } | |
d90e17a7 | 855 | |
774113b0 PA |
856 | /* Remove all LWPs belong to PID from the lwp list. */ |
857 | ||
858 | static void | |
859 | purge_lwp_list (int pid) | |
860 | { | |
861 | htab_traverse_noresize (lwp_lwpid_htab, lwp_lwpid_htab_remove_pid, &pid); | |
d90e17a7 PA |
862 | } |
863 | ||
26cb8b7c PA |
864 | /* Add the LWP specified by PTID to the list. PTID is the first LWP |
865 | in the process. Return a pointer to the structure describing the | |
866 | new LWP. | |
867 | ||
868 | This differs from add_lwp in that we don't let the arch specific | |
869 | bits know about this new thread. Current clients of this callback | |
870 | take the opportunity to install watchpoints in the new thread, and | |
871 | we shouldn't do that for the first thread. If we're spawning a | |
872 | child ("run"), the thread executes the shell wrapper first, and we | |
873 | shouldn't touch it until it execs the program we want to debug. | |
874 | For "attach", it'd be okay to call the callback, but it's not | |
875 | necessary, because watchpoints can't yet have been inserted into | |
876 | the inferior. */ | |
d6b0e80f AC |
877 | |
878 | static struct lwp_info * | |
26cb8b7c | 879 | add_initial_lwp (ptid_t ptid) |
d6b0e80f AC |
880 | { |
881 | struct lwp_info *lp; | |
882 | ||
15a9e13e | 883 | gdb_assert (ptid.lwp_p ()); |
d6b0e80f | 884 | |
8d749320 | 885 | lp = XNEW (struct lwp_info); |
d6b0e80f AC |
886 | |
887 | memset (lp, 0, sizeof (struct lwp_info)); | |
888 | ||
25289eb2 | 889 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
890 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
891 | ||
892 | lp->ptid = ptid; | |
dc146f7c | 893 | lp->core = -1; |
d6b0e80f | 894 | |
774113b0 PA |
895 | /* Add to sorted-by-reverse-creation-order list. */ |
896 | lwp_list_add (lp); | |
897 | ||
898 | /* Add to keyed-by-pid htab. */ | |
899 | lwp_lwpid_htab_add_lwp (lp); | |
d6b0e80f | 900 | |
26cb8b7c PA |
901 | return lp; |
902 | } | |
903 | ||
904 | /* Add the LWP specified by PID to the list. Return a pointer to the | |
905 | structure describing the new LWP. The LWP should already be | |
906 | stopped. */ | |
907 | ||
908 | static struct lwp_info * | |
909 | add_lwp (ptid_t ptid) | |
910 | { | |
911 | struct lwp_info *lp; | |
912 | ||
913 | lp = add_initial_lwp (ptid); | |
914 | ||
6e012a6c PA |
915 | /* Let the arch specific bits know about this new thread. Current |
916 | clients of this callback take the opportunity to install | |
26cb8b7c PA |
917 | watchpoints in the new thread. We don't do this for the first |
918 | thread though. See add_initial_lwp. */ | |
135340af | 919 | linux_target->low_new_thread (lp); |
9f0bdab8 | 920 | |
d6b0e80f AC |
921 | return lp; |
922 | } | |
923 | ||
924 | /* Remove the LWP specified by PID from the list. */ | |
925 | ||
926 | static void | |
927 | delete_lwp (ptid_t ptid) | |
928 | { | |
774113b0 PA |
929 | struct lwp_info *lp; |
930 | void **slot; | |
931 | struct lwp_info dummy; | |
d6b0e80f | 932 | |
774113b0 PA |
933 | dummy.ptid = ptid; |
934 | slot = htab_find_slot (lwp_lwpid_htab, &dummy, NO_INSERT); | |
935 | if (slot == NULL) | |
936 | return; | |
d6b0e80f | 937 | |
774113b0 PA |
938 | lp = *(struct lwp_info **) slot; |
939 | gdb_assert (lp != NULL); | |
d6b0e80f | 940 | |
774113b0 | 941 | htab_clear_slot (lwp_lwpid_htab, slot); |
d6b0e80f | 942 | |
774113b0 PA |
943 | /* Remove from sorted-by-creation-order list. */ |
944 | lwp_list_remove (lp); | |
d6b0e80f | 945 | |
774113b0 | 946 | /* Release. */ |
7b50312a | 947 | lwp_free (lp); |
d6b0e80f AC |
948 | } |
949 | ||
950 | /* Return a pointer to the structure describing the LWP corresponding | |
951 | to PID. If no corresponding LWP could be found, return NULL. */ | |
952 | ||
953 | static struct lwp_info * | |
954 | find_lwp_pid (ptid_t ptid) | |
955 | { | |
956 | struct lwp_info *lp; | |
957 | int lwp; | |
774113b0 | 958 | struct lwp_info dummy; |
d6b0e80f | 959 | |
15a9e13e | 960 | if (ptid.lwp_p ()) |
e38504b3 | 961 | lwp = ptid.lwp (); |
d6b0e80f | 962 | else |
e99b03dc | 963 | lwp = ptid.pid (); |
d6b0e80f | 964 | |
fd79271b | 965 | dummy.ptid = ptid_t (0, lwp, 0); |
774113b0 PA |
966 | lp = (struct lwp_info *) htab_find (lwp_lwpid_htab, &dummy); |
967 | return lp; | |
d6b0e80f AC |
968 | } |
969 | ||
6d4ee8c6 | 970 | /* See nat/linux-nat.h. */ |
d6b0e80f AC |
971 | |
972 | struct lwp_info * | |
d90e17a7 | 973 | iterate_over_lwps (ptid_t filter, |
d3a70e03 | 974 | gdb::function_view<iterate_over_lwps_ftype> callback) |
d6b0e80f AC |
975 | { |
976 | struct lwp_info *lp, *lpnext; | |
977 | ||
978 | for (lp = lwp_list; lp; lp = lpnext) | |
979 | { | |
980 | lpnext = lp->next; | |
d90e17a7 | 981 | |
26a57c92 | 982 | if (lp->ptid.matches (filter)) |
d90e17a7 | 983 | { |
d3a70e03 | 984 | if (callback (lp) != 0) |
d90e17a7 PA |
985 | return lp; |
986 | } | |
d6b0e80f AC |
987 | } |
988 | ||
989 | return NULL; | |
990 | } | |
991 | ||
2277426b PA |
992 | /* Update our internal state when changing from one checkpoint to |
993 | another indicated by NEW_PTID. We can only switch single-threaded | |
994 | applications, so we only create one new LWP, and the previous list | |
995 | is discarded. */ | |
f973ed9c DJ |
996 | |
997 | void | |
998 | linux_nat_switch_fork (ptid_t new_ptid) | |
999 | { | |
1000 | struct lwp_info *lp; | |
1001 | ||
e99b03dc | 1002 | purge_lwp_list (inferior_ptid.pid ()); |
2277426b | 1003 | |
f973ed9c DJ |
1004 | lp = add_lwp (new_ptid); |
1005 | lp->stopped = 1; | |
e26af52f | 1006 | |
2277426b PA |
1007 | /* This changes the thread's ptid while preserving the gdb thread |
1008 | num. Also changes the inferior pid, while preserving the | |
1009 | inferior num. */ | |
5b6d1e4f | 1010 | thread_change_ptid (linux_target, inferior_ptid, new_ptid); |
2277426b PA |
1011 | |
1012 | /* We've just told GDB core that the thread changed target id, but, | |
1013 | in fact, it really is a different thread, with different register | |
1014 | contents. */ | |
1015 | registers_changed (); | |
e26af52f DJ |
1016 | } |
1017 | ||
e26af52f DJ |
1018 | /* Handle the exit of a single thread LP. */ |
1019 | ||
1020 | static void | |
1021 | exit_lwp (struct lwp_info *lp) | |
1022 | { | |
5b6d1e4f | 1023 | struct thread_info *th = find_thread_ptid (linux_target, lp->ptid); |
063bfe2e VP |
1024 | |
1025 | if (th) | |
e26af52f | 1026 | { |
17faa917 | 1027 | if (print_thread_events) |
a068643d TT |
1028 | printf_unfiltered (_("[%s exited]\n"), |
1029 | target_pid_to_str (lp->ptid).c_str ()); | |
17faa917 | 1030 | |
00431a78 | 1031 | delete_thread (th); |
e26af52f DJ |
1032 | } |
1033 | ||
1034 | delete_lwp (lp->ptid); | |
1035 | } | |
1036 | ||
a0ef4274 DJ |
1037 | /* Wait for the LWP specified by LP, which we have just attached to. |
1038 | Returns a wait status for that LWP, to cache. */ | |
1039 | ||
1040 | static int | |
22827c51 | 1041 | linux_nat_post_attach_wait (ptid_t ptid, int *signalled) |
a0ef4274 | 1042 | { |
e38504b3 | 1043 | pid_t new_pid, pid = ptid.lwp (); |
a0ef4274 DJ |
1044 | int status; |
1045 | ||
644cebc9 | 1046 | if (linux_proc_pid_is_stopped (pid)) |
a0ef4274 | 1047 | { |
9327494e | 1048 | linux_nat_debug_printf ("Attaching to a stopped process"); |
a0ef4274 DJ |
1049 | |
1050 | /* The process is definitely stopped. It is in a job control | |
1051 | stop, unless the kernel predates the TASK_STOPPED / | |
1052 | TASK_TRACED distinction, in which case it might be in a | |
1053 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
1054 | can kill it, signal it, et cetera. | |
1055 | ||
1056 | First make sure there is a pending SIGSTOP. Since we are | |
1057 | already attached, the process can not transition from stopped | |
1058 | to running without a PTRACE_CONT; so we know this signal will | |
1059 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
1060 | probably already in the queue (unless this kernel is old | |
1061 | enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP | |
1062 | is not an RT signal, it can only be queued once. */ | |
1063 | kill_lwp (pid, SIGSTOP); | |
1064 | ||
1065 | /* Finally, resume the stopped process. This will deliver the SIGSTOP | |
1066 | (or a higher priority signal, just like normal PTRACE_ATTACH). */ | |
1067 | ptrace (PTRACE_CONT, pid, 0, 0); | |
1068 | } | |
1069 | ||
1070 | /* Make sure the initial process is stopped. The user-level threads | |
1071 | layer might want to poke around in the inferior, and that won't | |
1072 | work if things haven't stabilized yet. */ | |
4a6ed09b | 1073 | new_pid = my_waitpid (pid, &status, __WALL); |
dacc9cb2 PP |
1074 | gdb_assert (pid == new_pid); |
1075 | ||
1076 | if (!WIFSTOPPED (status)) | |
1077 | { | |
1078 | /* The pid we tried to attach has apparently just exited. */ | |
9327494e SM |
1079 | linux_nat_debug_printf ("Failed to stop %d: %s", pid, |
1080 | status_to_str (status)); | |
dacc9cb2 PP |
1081 | return status; |
1082 | } | |
a0ef4274 DJ |
1083 | |
1084 | if (WSTOPSIG (status) != SIGSTOP) | |
1085 | { | |
1086 | *signalled = 1; | |
9327494e SM |
1087 | linux_nat_debug_printf ("Received %s after attaching", |
1088 | status_to_str (status)); | |
a0ef4274 DJ |
1089 | } |
1090 | ||
1091 | return status; | |
1092 | } | |
1093 | ||
f6ac5f3d PA |
1094 | void |
1095 | linux_nat_target::create_inferior (const char *exec_file, | |
1096 | const std::string &allargs, | |
1097 | char **env, int from_tty) | |
b84876c2 | 1098 | { |
41272101 TT |
1099 | maybe_disable_address_space_randomization restore_personality |
1100 | (disable_randomization); | |
b84876c2 PA |
1101 | |
1102 | /* The fork_child mechanism is synchronous and calls target_wait, so | |
1103 | we have to mask the async mode. */ | |
1104 | ||
2455069d | 1105 | /* Make sure we report all signals during startup. */ |
adc6a863 | 1106 | pass_signals ({}); |
2455069d | 1107 | |
f6ac5f3d | 1108 | inf_ptrace_target::create_inferior (exec_file, allargs, env, from_tty); |
b84876c2 PA |
1109 | } |
1110 | ||
8784d563 PA |
1111 | /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not |
1112 | already attached. Returns true if a new LWP is found, false | |
1113 | otherwise. */ | |
1114 | ||
1115 | static int | |
1116 | attach_proc_task_lwp_callback (ptid_t ptid) | |
1117 | { | |
1118 | struct lwp_info *lp; | |
1119 | ||
1120 | /* Ignore LWPs we're already attached to. */ | |
1121 | lp = find_lwp_pid (ptid); | |
1122 | if (lp == NULL) | |
1123 | { | |
e38504b3 | 1124 | int lwpid = ptid.lwp (); |
8784d563 PA |
1125 | |
1126 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) | |
1127 | { | |
1128 | int err = errno; | |
1129 | ||
1130 | /* Be quiet if we simply raced with the thread exiting. | |
1131 | EPERM is returned if the thread's task still exists, and | |
1132 | is marked as exited or zombie, as well as other | |
1133 | conditions, so in that case, confirm the status in | |
1134 | /proc/PID/status. */ | |
1135 | if (err == ESRCH | |
1136 | || (err == EPERM && linux_proc_pid_is_gone (lwpid))) | |
1137 | { | |
9327494e SM |
1138 | linux_nat_debug_printf |
1139 | ("Cannot attach to lwp %d: thread is gone (%d: %s)", | |
1140 | lwpid, err, safe_strerror (err)); | |
1141 | ||
8784d563 PA |
1142 | } |
1143 | else | |
1144 | { | |
4d9b86e1 | 1145 | std::string reason |
50fa3001 | 1146 | = linux_ptrace_attach_fail_reason_string (ptid, err); |
4d9b86e1 | 1147 | |
f71f0b0d | 1148 | warning (_("Cannot attach to lwp %d: %s"), |
4d9b86e1 | 1149 | lwpid, reason.c_str ()); |
8784d563 PA |
1150 | } |
1151 | } | |
1152 | else | |
1153 | { | |
9327494e SM |
1154 | linux_nat_debug_printf ("PTRACE_ATTACH %s, 0, 0 (OK)", |
1155 | target_pid_to_str (ptid).c_str ()); | |
8784d563 PA |
1156 | |
1157 | lp = add_lwp (ptid); | |
8784d563 PA |
1158 | |
1159 | /* The next time we wait for this LWP we'll see a SIGSTOP as | |
1160 | PTRACE_ATTACH brings it to a halt. */ | |
1161 | lp->signalled = 1; | |
1162 | ||
1163 | /* We need to wait for a stop before being able to make the | |
1164 | next ptrace call on this LWP. */ | |
1165 | lp->must_set_ptrace_flags = 1; | |
026a9174 PA |
1166 | |
1167 | /* So that wait collects the SIGSTOP. */ | |
1168 | lp->resumed = 1; | |
1169 | ||
1170 | /* Also add the LWP to gdb's thread list, in case a | |
1171 | matching libthread_db is not found (or the process uses | |
1172 | raw clone). */ | |
5b6d1e4f | 1173 | add_thread (linux_target, lp->ptid); |
719546c4 SM |
1174 | set_running (linux_target, lp->ptid, true); |
1175 | set_executing (linux_target, lp->ptid, true); | |
8784d563 PA |
1176 | } |
1177 | ||
1178 | return 1; | |
1179 | } | |
1180 | return 0; | |
1181 | } | |
1182 | ||
f6ac5f3d PA |
1183 | void |
1184 | linux_nat_target::attach (const char *args, int from_tty) | |
d6b0e80f AC |
1185 | { |
1186 | struct lwp_info *lp; | |
d6b0e80f | 1187 | int status; |
af990527 | 1188 | ptid_t ptid; |
d6b0e80f | 1189 | |
2455069d | 1190 | /* Make sure we report all signals during attach. */ |
adc6a863 | 1191 | pass_signals ({}); |
2455069d | 1192 | |
a70b8144 | 1193 | try |
87b0bb13 | 1194 | { |
f6ac5f3d | 1195 | inf_ptrace_target::attach (args, from_tty); |
87b0bb13 | 1196 | } |
230d2906 | 1197 | catch (const gdb_exception_error &ex) |
87b0bb13 JK |
1198 | { |
1199 | pid_t pid = parse_pid_to_attach (args); | |
50fa3001 | 1200 | std::string reason = linux_ptrace_attach_fail_reason (pid); |
87b0bb13 | 1201 | |
4d9b86e1 | 1202 | if (!reason.empty ()) |
3d6e9d23 TT |
1203 | throw_error (ex.error, "warning: %s\n%s", reason.c_str (), |
1204 | ex.what ()); | |
7ae1a6a6 | 1205 | else |
3d6e9d23 | 1206 | throw_error (ex.error, "%s", ex.what ()); |
87b0bb13 | 1207 | } |
d6b0e80f | 1208 | |
af990527 PA |
1209 | /* The ptrace base target adds the main thread with (pid,0,0) |
1210 | format. Decorate it with lwp info. */ | |
e99b03dc TT |
1211 | ptid = ptid_t (inferior_ptid.pid (), |
1212 | inferior_ptid.pid (), | |
fd79271b | 1213 | 0); |
5b6d1e4f | 1214 | thread_change_ptid (linux_target, inferior_ptid, ptid); |
af990527 | 1215 | |
9f0bdab8 | 1216 | /* Add the initial process as the first LWP to the list. */ |
26cb8b7c | 1217 | lp = add_initial_lwp (ptid); |
a0ef4274 | 1218 | |
22827c51 | 1219 | status = linux_nat_post_attach_wait (lp->ptid, &lp->signalled); |
dacc9cb2 PP |
1220 | if (!WIFSTOPPED (status)) |
1221 | { | |
1222 | if (WIFEXITED (status)) | |
1223 | { | |
1224 | int exit_code = WEXITSTATUS (status); | |
1225 | ||
223ffa71 | 1226 | target_terminal::ours (); |
bc1e6c81 | 1227 | target_mourn_inferior (inferior_ptid); |
dacc9cb2 PP |
1228 | if (exit_code == 0) |
1229 | error (_("Unable to attach: program exited normally.")); | |
1230 | else | |
1231 | error (_("Unable to attach: program exited with code %d."), | |
1232 | exit_code); | |
1233 | } | |
1234 | else if (WIFSIGNALED (status)) | |
1235 | { | |
2ea28649 | 1236 | enum gdb_signal signo; |
dacc9cb2 | 1237 | |
223ffa71 | 1238 | target_terminal::ours (); |
bc1e6c81 | 1239 | target_mourn_inferior (inferior_ptid); |
dacc9cb2 | 1240 | |
2ea28649 | 1241 | signo = gdb_signal_from_host (WTERMSIG (status)); |
dacc9cb2 PP |
1242 | error (_("Unable to attach: program terminated with signal " |
1243 | "%s, %s."), | |
2ea28649 PA |
1244 | gdb_signal_to_name (signo), |
1245 | gdb_signal_to_string (signo)); | |
dacc9cb2 PP |
1246 | } |
1247 | ||
1248 | internal_error (__FILE__, __LINE__, | |
1249 | _("unexpected status %d for PID %ld"), | |
e38504b3 | 1250 | status, (long) ptid.lwp ()); |
dacc9cb2 PP |
1251 | } |
1252 | ||
a0ef4274 | 1253 | lp->stopped = 1; |
9f0bdab8 | 1254 | |
a0ef4274 | 1255 | /* Save the wait status to report later. */ |
d6b0e80f | 1256 | lp->resumed = 1; |
9327494e SM |
1257 | linux_nat_debug_printf ("waitpid %ld, saving status %s", |
1258 | (long) lp->ptid.pid (), status_to_str (status)); | |
710151dd | 1259 | |
7feb7d06 PA |
1260 | lp->status = status; |
1261 | ||
8784d563 PA |
1262 | /* We must attach to every LWP. If /proc is mounted, use that to |
1263 | find them now. The inferior may be using raw clone instead of | |
1264 | using pthreads. But even if it is using pthreads, thread_db | |
1265 | walks structures in the inferior's address space to find the list | |
1266 | of threads/LWPs, and those structures may well be corrupted. | |
1267 | Note that once thread_db is loaded, we'll still use it to list | |
1268 | threads and associate pthread info with each LWP. */ | |
e99b03dc | 1269 | linux_proc_attach_tgid_threads (lp->ptid.pid (), |
8784d563 PA |
1270 | attach_proc_task_lwp_callback); |
1271 | ||
7feb7d06 | 1272 | if (target_can_async_p ()) |
6a3753b3 | 1273 | target_async (1); |
d6b0e80f AC |
1274 | } |
1275 | ||
ced2dffb PA |
1276 | /* Get pending signal of THREAD as a host signal number, for detaching |
1277 | purposes. This is the signal the thread last stopped for, which we | |
1278 | need to deliver to the thread when detaching, otherwise, it'd be | |
1279 | suppressed/lost. */ | |
1280 | ||
a0ef4274 | 1281 | static int |
ced2dffb | 1282 | get_detach_signal (struct lwp_info *lp) |
a0ef4274 | 1283 | { |
a493e3e2 | 1284 | enum gdb_signal signo = GDB_SIGNAL_0; |
ca2163eb PA |
1285 | |
1286 | /* If we paused threads momentarily, we may have stored pending | |
1287 | events in lp->status or lp->waitstatus (see stop_wait_callback), | |
1288 | and GDB core hasn't seen any signal for those threads. | |
1289 | Otherwise, the last signal reported to the core is found in the | |
1290 | thread object's stop_signal. | |
1291 | ||
1292 | There's a corner case that isn't handled here at present. Only | |
1293 | if the thread stopped with a TARGET_WAITKIND_STOPPED does | |
1294 | stop_signal make sense as a real signal to pass to the inferior. | |
1295 | Some catchpoint related events, like | |
1296 | TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set | |
a493e3e2 | 1297 | to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But, |
ca2163eb PA |
1298 | those traps are debug API (ptrace in our case) related and |
1299 | induced; the inferior wouldn't see them if it wasn't being | |
1300 | traced. Hence, we should never pass them to the inferior, even | |
1301 | when set to pass state. Since this corner case isn't handled by | |
1302 | infrun.c when proceeding with a signal, for consistency, neither | |
1303 | do we handle it here (or elsewhere in the file we check for | |
1304 | signal pass state). Normally SIGTRAP isn't set to pass state, so | |
1305 | this is really a corner case. */ | |
1306 | ||
1307 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
a493e3e2 | 1308 | signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */ |
ca2163eb | 1309 | else if (lp->status) |
2ea28649 | 1310 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
00431a78 | 1311 | else |
ca2163eb | 1312 | { |
5b6d1e4f | 1313 | struct thread_info *tp = find_thread_ptid (linux_target, lp->ptid); |
e0881a8e | 1314 | |
00431a78 | 1315 | if (target_is_non_stop_p () && !tp->executing) |
ca2163eb | 1316 | { |
00431a78 PA |
1317 | if (tp->suspend.waitstatus_pending_p) |
1318 | signo = tp->suspend.waitstatus.value.sig; | |
1319 | else | |
1320 | signo = tp->suspend.stop_signal; | |
1321 | } | |
1322 | else if (!target_is_non_stop_p ()) | |
1323 | { | |
00431a78 | 1324 | ptid_t last_ptid; |
5b6d1e4f | 1325 | process_stratum_target *last_target; |
00431a78 | 1326 | |
5b6d1e4f | 1327 | get_last_target_status (&last_target, &last_ptid, nullptr); |
e0881a8e | 1328 | |
5b6d1e4f PA |
1329 | if (last_target == linux_target |
1330 | && lp->ptid.lwp () == last_ptid.lwp ()) | |
00431a78 | 1331 | signo = tp->suspend.stop_signal; |
4c28f408 | 1332 | } |
ca2163eb | 1333 | } |
4c28f408 | 1334 | |
a493e3e2 | 1335 | if (signo == GDB_SIGNAL_0) |
ca2163eb | 1336 | { |
9327494e SM |
1337 | linux_nat_debug_printf ("lwp %s has no pending signal", |
1338 | target_pid_to_str (lp->ptid).c_str ()); | |
ca2163eb PA |
1339 | } |
1340 | else if (!signal_pass_state (signo)) | |
1341 | { | |
9327494e SM |
1342 | linux_nat_debug_printf |
1343 | ("lwp %s had signal %s but it is in no pass state", | |
1344 | target_pid_to_str (lp->ptid).c_str (), gdb_signal_to_string (signo)); | |
a0ef4274 | 1345 | } |
a0ef4274 | 1346 | else |
4c28f408 | 1347 | { |
9327494e SM |
1348 | linux_nat_debug_printf ("lwp %s has pending signal %s", |
1349 | target_pid_to_str (lp->ptid).c_str (), | |
1350 | gdb_signal_to_string (signo)); | |
ced2dffb PA |
1351 | |
1352 | return gdb_signal_to_host (signo); | |
4c28f408 | 1353 | } |
a0ef4274 DJ |
1354 | |
1355 | return 0; | |
1356 | } | |
1357 | ||
ced2dffb PA |
1358 | /* Detach from LP. If SIGNO_P is non-NULL, then it points to the |
1359 | signal number that should be passed to the LWP when detaching. | |
1360 | Otherwise pass any pending signal the LWP may have, if any. */ | |
1361 | ||
1362 | static void | |
1363 | detach_one_lwp (struct lwp_info *lp, int *signo_p) | |
d6b0e80f | 1364 | { |
e38504b3 | 1365 | int lwpid = lp->ptid.lwp (); |
ced2dffb PA |
1366 | int signo; |
1367 | ||
d6b0e80f AC |
1368 | gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status)); |
1369 | ||
9327494e SM |
1370 | if (lp->status != 0) |
1371 | linux_nat_debug_printf ("Pending %s for %s on detach.", | |
1372 | strsignal (WSTOPSIG (lp->status)), | |
1373 | target_pid_to_str (lp->ptid).c_str ()); | |
d6b0e80f | 1374 | |
a0ef4274 DJ |
1375 | /* If there is a pending SIGSTOP, get rid of it. */ |
1376 | if (lp->signalled) | |
d6b0e80f | 1377 | { |
9327494e SM |
1378 | linux_nat_debug_printf ("Sending SIGCONT to %s", |
1379 | target_pid_to_str (lp->ptid).c_str ()); | |
d6b0e80f | 1380 | |
ced2dffb | 1381 | kill_lwp (lwpid, SIGCONT); |
d6b0e80f | 1382 | lp->signalled = 0; |
d6b0e80f AC |
1383 | } |
1384 | ||
ced2dffb | 1385 | if (signo_p == NULL) |
d6b0e80f | 1386 | { |
a0ef4274 | 1387 | /* Pass on any pending signal for this LWP. */ |
ced2dffb PA |
1388 | signo = get_detach_signal (lp); |
1389 | } | |
1390 | else | |
1391 | signo = *signo_p; | |
a0ef4274 | 1392 | |
ced2dffb PA |
1393 | /* Preparing to resume may try to write registers, and fail if the |
1394 | lwp is zombie. If that happens, ignore the error. We'll handle | |
1395 | it below, when detach fails with ESRCH. */ | |
a70b8144 | 1396 | try |
ced2dffb | 1397 | { |
135340af | 1398 | linux_target->low_prepare_to_resume (lp); |
ced2dffb | 1399 | } |
230d2906 | 1400 | catch (const gdb_exception_error &ex) |
ced2dffb PA |
1401 | { |
1402 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 1403 | throw; |
ced2dffb | 1404 | } |
d6b0e80f | 1405 | |
ced2dffb PA |
1406 | if (ptrace (PTRACE_DETACH, lwpid, 0, signo) < 0) |
1407 | { | |
1408 | int save_errno = errno; | |
1409 | ||
1410 | /* We know the thread exists, so ESRCH must mean the lwp is | |
1411 | zombie. This can happen if one of the already-detached | |
1412 | threads exits the whole thread group. In that case we're | |
1413 | still attached, and must reap the lwp. */ | |
1414 | if (save_errno == ESRCH) | |
1415 | { | |
1416 | int ret, status; | |
d6b0e80f | 1417 | |
ced2dffb PA |
1418 | ret = my_waitpid (lwpid, &status, __WALL); |
1419 | if (ret == -1) | |
1420 | { | |
1421 | warning (_("Couldn't reap LWP %d while detaching: %s"), | |
6d91ce9a | 1422 | lwpid, safe_strerror (errno)); |
ced2dffb PA |
1423 | } |
1424 | else if (!WIFEXITED (status) && !WIFSIGNALED (status)) | |
1425 | { | |
1426 | warning (_("Reaping LWP %d while detaching " | |
1427 | "returned unexpected status 0x%x"), | |
1428 | lwpid, status); | |
1429 | } | |
1430 | } | |
1431 | else | |
1432 | { | |
a068643d TT |
1433 | error (_("Can't detach %s: %s"), |
1434 | target_pid_to_str (lp->ptid).c_str (), | |
ced2dffb PA |
1435 | safe_strerror (save_errno)); |
1436 | } | |
d6b0e80f | 1437 | } |
9327494e SM |
1438 | else |
1439 | linux_nat_debug_printf ("PTRACE_DETACH (%s, %s, 0) (OK)", | |
1440 | target_pid_to_str (lp->ptid).c_str (), | |
1441 | strsignal (signo)); | |
ced2dffb PA |
1442 | |
1443 | delete_lwp (lp->ptid); | |
1444 | } | |
d6b0e80f | 1445 | |
ced2dffb | 1446 | static int |
d3a70e03 | 1447 | detach_callback (struct lwp_info *lp) |
ced2dffb PA |
1448 | { |
1449 | /* We don't actually detach from the thread group leader just yet. | |
1450 | If the thread group exits, we must reap the zombie clone lwps | |
1451 | before we're able to reap the leader. */ | |
e38504b3 | 1452 | if (lp->ptid.lwp () != lp->ptid.pid ()) |
ced2dffb | 1453 | detach_one_lwp (lp, NULL); |
d6b0e80f AC |
1454 | return 0; |
1455 | } | |
1456 | ||
f6ac5f3d PA |
1457 | void |
1458 | linux_nat_target::detach (inferior *inf, int from_tty) | |
d6b0e80f | 1459 | { |
d90e17a7 | 1460 | struct lwp_info *main_lwp; |
bc09b0c1 | 1461 | int pid = inf->pid; |
a0ef4274 | 1462 | |
ae5e0686 MK |
1463 | /* Don't unregister from the event loop, as there may be other |
1464 | inferiors running. */ | |
b84876c2 | 1465 | |
4c28f408 | 1466 | /* Stop all threads before detaching. ptrace requires that the |
30baf67b | 1467 | thread is stopped to successfully detach. */ |
d3a70e03 | 1468 | iterate_over_lwps (ptid_t (pid), stop_callback); |
4c28f408 PA |
1469 | /* ... and wait until all of them have reported back that |
1470 | they're no longer running. */ | |
d3a70e03 | 1471 | iterate_over_lwps (ptid_t (pid), stop_wait_callback); |
4c28f408 | 1472 | |
d3a70e03 | 1473 | iterate_over_lwps (ptid_t (pid), detach_callback); |
d6b0e80f AC |
1474 | |
1475 | /* Only the initial process should be left right now. */ | |
bc09b0c1 | 1476 | gdb_assert (num_lwps (pid) == 1); |
d90e17a7 | 1477 | |
f2907e49 | 1478 | main_lwp = find_lwp_pid (ptid_t (pid)); |
d6b0e80f | 1479 | |
7a7d3353 PA |
1480 | if (forks_exist_p ()) |
1481 | { | |
1482 | /* Multi-fork case. The current inferior_ptid is being detached | |
1483 | from, but there are other viable forks to debug. Detach from | |
1484 | the current fork, and context-switch to the first | |
1485 | available. */ | |
6bd6f3b6 | 1486 | linux_fork_detach (from_tty); |
7a7d3353 PA |
1487 | } |
1488 | else | |
ced2dffb | 1489 | { |
ced2dffb PA |
1490 | target_announce_detach (from_tty); |
1491 | ||
6bd6f3b6 SM |
1492 | /* Pass on any pending signal for the last LWP. */ |
1493 | int signo = get_detach_signal (main_lwp); | |
ced2dffb PA |
1494 | |
1495 | detach_one_lwp (main_lwp, &signo); | |
1496 | ||
f6ac5f3d | 1497 | detach_success (inf); |
ced2dffb | 1498 | } |
d6b0e80f AC |
1499 | } |
1500 | ||
8a99810d PA |
1501 | /* Resume execution of the inferior process. If STEP is nonzero, |
1502 | single-step it. If SIGNAL is nonzero, give it that signal. */ | |
1503 | ||
1504 | static void | |
23f238d3 PA |
1505 | linux_resume_one_lwp_throw (struct lwp_info *lp, int step, |
1506 | enum gdb_signal signo) | |
8a99810d | 1507 | { |
8a99810d | 1508 | lp->step = step; |
9c02b525 PA |
1509 | |
1510 | /* stop_pc doubles as the PC the LWP had when it was last resumed. | |
1511 | We only presently need that if the LWP is stepped though (to | |
1512 | handle the case of stepping a breakpoint instruction). */ | |
1513 | if (step) | |
1514 | { | |
5b6d1e4f | 1515 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
9c02b525 PA |
1516 | |
1517 | lp->stop_pc = regcache_read_pc (regcache); | |
1518 | } | |
1519 | else | |
1520 | lp->stop_pc = 0; | |
1521 | ||
135340af | 1522 | linux_target->low_prepare_to_resume (lp); |
f6ac5f3d | 1523 | linux_target->low_resume (lp->ptid, step, signo); |
23f238d3 PA |
1524 | |
1525 | /* Successfully resumed. Clear state that no longer makes sense, | |
1526 | and mark the LWP as running. Must not do this before resuming | |
1527 | otherwise if that fails other code will be confused. E.g., we'd | |
1528 | later try to stop the LWP and hang forever waiting for a stop | |
1529 | status. Note that we must not throw after this is cleared, | |
1530 | otherwise handle_zombie_lwp_error would get confused. */ | |
8a99810d | 1531 | lp->stopped = 0; |
1ad3de98 | 1532 | lp->core = -1; |
23f238d3 | 1533 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; |
5b6d1e4f | 1534 | registers_changed_ptid (linux_target, lp->ptid); |
8a99810d PA |
1535 | } |
1536 | ||
23f238d3 PA |
1537 | /* Called when we try to resume a stopped LWP and that errors out. If |
1538 | the LWP is no longer in ptrace-stopped state (meaning it's zombie, | |
1539 | or about to become), discard the error, clear any pending status | |
1540 | the LWP may have, and return true (we'll collect the exit status | |
1541 | soon enough). Otherwise, return false. */ | |
1542 | ||
1543 | static int | |
1544 | check_ptrace_stopped_lwp_gone (struct lwp_info *lp) | |
1545 | { | |
1546 | /* If we get an error after resuming the LWP successfully, we'd | |
1547 | confuse !T state for the LWP being gone. */ | |
1548 | gdb_assert (lp->stopped); | |
1549 | ||
1550 | /* We can't just check whether the LWP is in 'Z (Zombie)' state, | |
1551 | because even if ptrace failed with ESRCH, the tracee may be "not | |
1552 | yet fully dead", but already refusing ptrace requests. In that | |
1553 | case the tracee has 'R (Running)' state for a little bit | |
1554 | (observed in Linux 3.18). See also the note on ESRCH in the | |
1555 | ptrace(2) man page. Instead, check whether the LWP has any state | |
1556 | other than ptrace-stopped. */ | |
1557 | ||
1558 | /* Don't assume anything if /proc/PID/status can't be read. */ | |
e38504b3 | 1559 | if (linux_proc_pid_is_trace_stopped_nowarn (lp->ptid.lwp ()) == 0) |
23f238d3 PA |
1560 | { |
1561 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; | |
1562 | lp->status = 0; | |
1563 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
1564 | return 1; | |
1565 | } | |
1566 | return 0; | |
1567 | } | |
1568 | ||
1569 | /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP | |
1570 | disappears while we try to resume it. */ | |
1571 | ||
1572 | static void | |
1573 | linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) | |
1574 | { | |
a70b8144 | 1575 | try |
23f238d3 PA |
1576 | { |
1577 | linux_resume_one_lwp_throw (lp, step, signo); | |
1578 | } | |
230d2906 | 1579 | catch (const gdb_exception_error &ex) |
23f238d3 PA |
1580 | { |
1581 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 1582 | throw; |
23f238d3 | 1583 | } |
23f238d3 PA |
1584 | } |
1585 | ||
d6b0e80f AC |
1586 | /* Resume LP. */ |
1587 | ||
25289eb2 | 1588 | static void |
e5ef252a | 1589 | resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) |
d6b0e80f | 1590 | { |
25289eb2 | 1591 | if (lp->stopped) |
6c95b8df | 1592 | { |
5b6d1e4f | 1593 | struct inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
25289eb2 PA |
1594 | |
1595 | if (inf->vfork_child != NULL) | |
1596 | { | |
9327494e SM |
1597 | linux_nat_debug_printf ("Not resuming %s (vfork parent)", |
1598 | target_pid_to_str (lp->ptid).c_str ()); | |
25289eb2 | 1599 | } |
8a99810d | 1600 | else if (!lwp_status_pending_p (lp)) |
25289eb2 | 1601 | { |
9327494e SM |
1602 | linux_nat_debug_printf ("Resuming sibling %s, %s, %s", |
1603 | target_pid_to_str (lp->ptid).c_str (), | |
1604 | (signo != GDB_SIGNAL_0 | |
1605 | ? strsignal (gdb_signal_to_host (signo)) | |
1606 | : "0"), | |
1607 | step ? "step" : "resume"); | |
25289eb2 | 1608 | |
8a99810d | 1609 | linux_resume_one_lwp (lp, step, signo); |
25289eb2 PA |
1610 | } |
1611 | else | |
1612 | { | |
9327494e SM |
1613 | linux_nat_debug_printf ("Not resuming sibling %s (has pending)", |
1614 | target_pid_to_str (lp->ptid).c_str ()); | |
25289eb2 | 1615 | } |
6c95b8df | 1616 | } |
25289eb2 | 1617 | else |
9327494e | 1618 | linux_nat_debug_printf ("Not resuming sibling %s (not stopped)", |
a068643d | 1619 | target_pid_to_str (lp->ptid).c_str ()); |
25289eb2 | 1620 | } |
d6b0e80f | 1621 | |
8817a6f2 PA |
1622 | /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing. |
1623 | Resume LWP with the last stop signal, if it is in pass state. */ | |
e5ef252a | 1624 | |
25289eb2 | 1625 | static int |
d3a70e03 | 1626 | linux_nat_resume_callback (struct lwp_info *lp, struct lwp_info *except) |
25289eb2 | 1627 | { |
e5ef252a PA |
1628 | enum gdb_signal signo = GDB_SIGNAL_0; |
1629 | ||
8817a6f2 PA |
1630 | if (lp == except) |
1631 | return 0; | |
1632 | ||
e5ef252a PA |
1633 | if (lp->stopped) |
1634 | { | |
1635 | struct thread_info *thread; | |
1636 | ||
5b6d1e4f | 1637 | thread = find_thread_ptid (linux_target, lp->ptid); |
e5ef252a PA |
1638 | if (thread != NULL) |
1639 | { | |
70509625 | 1640 | signo = thread->suspend.stop_signal; |
e5ef252a PA |
1641 | thread->suspend.stop_signal = GDB_SIGNAL_0; |
1642 | } | |
1643 | } | |
1644 | ||
1645 | resume_lwp (lp, 0, signo); | |
d6b0e80f AC |
1646 | return 0; |
1647 | } | |
1648 | ||
1649 | static int | |
d3a70e03 | 1650 | resume_clear_callback (struct lwp_info *lp) |
d6b0e80f AC |
1651 | { |
1652 | lp->resumed = 0; | |
25289eb2 | 1653 | lp->last_resume_kind = resume_stop; |
d6b0e80f AC |
1654 | return 0; |
1655 | } | |
1656 | ||
1657 | static int | |
d3a70e03 | 1658 | resume_set_callback (struct lwp_info *lp) |
d6b0e80f AC |
1659 | { |
1660 | lp->resumed = 1; | |
25289eb2 | 1661 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1662 | return 0; |
1663 | } | |
1664 | ||
f6ac5f3d PA |
1665 | void |
1666 | linux_nat_target::resume (ptid_t ptid, int step, enum gdb_signal signo) | |
d6b0e80f AC |
1667 | { |
1668 | struct lwp_info *lp; | |
d90e17a7 | 1669 | int resume_many; |
d6b0e80f | 1670 | |
9327494e SM |
1671 | linux_nat_debug_printf ("Preparing to %s %s, %s, inferior_ptid %s", |
1672 | step ? "step" : "resume", | |
1673 | target_pid_to_str (ptid).c_str (), | |
1674 | (signo != GDB_SIGNAL_0 | |
1675 | ? strsignal (gdb_signal_to_host (signo)) : "0"), | |
1676 | target_pid_to_str (inferior_ptid).c_str ()); | |
76f50ad1 | 1677 | |
d6b0e80f | 1678 | /* A specific PTID means `step only this process id'. */ |
d7e15655 | 1679 | resume_many = (minus_one_ptid == ptid |
0e998d96 | 1680 | || ptid.is_pid ()); |
4c28f408 | 1681 | |
7da6a5b9 LM |
1682 | /* Mark the lwps we're resuming as resumed and update their |
1683 | last_resume_kind to resume_continue. */ | |
d3a70e03 | 1684 | iterate_over_lwps (ptid, resume_set_callback); |
d6b0e80f | 1685 | |
d90e17a7 PA |
1686 | /* See if it's the current inferior that should be handled |
1687 | specially. */ | |
1688 | if (resume_many) | |
1689 | lp = find_lwp_pid (inferior_ptid); | |
1690 | else | |
1691 | lp = find_lwp_pid (ptid); | |
9f0bdab8 | 1692 | gdb_assert (lp != NULL); |
d6b0e80f | 1693 | |
9f0bdab8 | 1694 | /* Remember if we're stepping. */ |
25289eb2 | 1695 | lp->last_resume_kind = step ? resume_step : resume_continue; |
d6b0e80f | 1696 | |
9f0bdab8 DJ |
1697 | /* If we have a pending wait status for this thread, there is no |
1698 | point in resuming the process. But first make sure that | |
1699 | linux_nat_wait won't preemptively handle the event - we | |
1700 | should never take this short-circuit if we are going to | |
1701 | leave LP running, since we have skipped resuming all the | |
1702 | other threads. This bit of code needs to be synchronized | |
1703 | with linux_nat_wait. */ | |
76f50ad1 | 1704 | |
9f0bdab8 DJ |
1705 | if (lp->status && WIFSTOPPED (lp->status)) |
1706 | { | |
2455069d UW |
1707 | if (!lp->step |
1708 | && WSTOPSIG (lp->status) | |
1709 | && sigismember (&pass_mask, WSTOPSIG (lp->status))) | |
d6b0e80f | 1710 | { |
9327494e SM |
1711 | linux_nat_debug_printf |
1712 | ("Not short circuiting for ignored status 0x%x", lp->status); | |
9f0bdab8 | 1713 | |
d6b0e80f AC |
1714 | /* FIXME: What should we do if we are supposed to continue |
1715 | this thread with a signal? */ | |
a493e3e2 | 1716 | gdb_assert (signo == GDB_SIGNAL_0); |
2ea28649 | 1717 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
9f0bdab8 DJ |
1718 | lp->status = 0; |
1719 | } | |
1720 | } | |
76f50ad1 | 1721 | |
8a99810d | 1722 | if (lwp_status_pending_p (lp)) |
9f0bdab8 DJ |
1723 | { |
1724 | /* FIXME: What should we do if we are supposed to continue | |
1725 | this thread with a signal? */ | |
a493e3e2 | 1726 | gdb_assert (signo == GDB_SIGNAL_0); |
76f50ad1 | 1727 | |
9327494e SM |
1728 | linux_nat_debug_printf ("Short circuiting for status 0x%x", |
1729 | lp->status); | |
d6b0e80f | 1730 | |
7feb7d06 PA |
1731 | if (target_can_async_p ()) |
1732 | { | |
6a3753b3 | 1733 | target_async (1); |
7feb7d06 PA |
1734 | /* Tell the event loop we have something to process. */ |
1735 | async_file_mark (); | |
1736 | } | |
9f0bdab8 | 1737 | return; |
d6b0e80f AC |
1738 | } |
1739 | ||
d90e17a7 | 1740 | if (resume_many) |
d3a70e03 TT |
1741 | iterate_over_lwps (ptid, [=] (struct lwp_info *info) |
1742 | { | |
1743 | return linux_nat_resume_callback (info, lp); | |
1744 | }); | |
d90e17a7 | 1745 | |
9327494e SM |
1746 | linux_nat_debug_printf ("%s %s, %s (resume event thread)", |
1747 | step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
1748 | target_pid_to_str (lp->ptid).c_str (), | |
1749 | (signo != GDB_SIGNAL_0 | |
1750 | ? strsignal (gdb_signal_to_host (signo)) : "0")); | |
b84876c2 | 1751 | |
2bf6fb9d PA |
1752 | linux_resume_one_lwp (lp, step, signo); |
1753 | ||
b84876c2 | 1754 | if (target_can_async_p ()) |
6a3753b3 | 1755 | target_async (1); |
d6b0e80f AC |
1756 | } |
1757 | ||
c5f62d5f | 1758 | /* Send a signal to an LWP. */ |
d6b0e80f AC |
1759 | |
1760 | static int | |
1761 | kill_lwp (int lwpid, int signo) | |
1762 | { | |
4a6ed09b | 1763 | int ret; |
d6b0e80f | 1764 | |
4a6ed09b PA |
1765 | errno = 0; |
1766 | ret = syscall (__NR_tkill, lwpid, signo); | |
1767 | if (errno == ENOSYS) | |
1768 | { | |
1769 | /* If tkill fails, then we are not using nptl threads, a | |
1770 | configuration we no longer support. */ | |
1771 | perror_with_name (("tkill")); | |
1772 | } | |
1773 | return ret; | |
d6b0e80f AC |
1774 | } |
1775 | ||
ca2163eb PA |
1776 | /* Handle a GNU/Linux syscall trap wait response. If we see a syscall |
1777 | event, check if the core is interested in it: if not, ignore the | |
1778 | event, and keep waiting; otherwise, we need to toggle the LWP's | |
1779 | syscall entry/exit status, since the ptrace event itself doesn't | |
1780 | indicate it, and report the trap to higher layers. */ | |
1781 | ||
1782 | static int | |
1783 | linux_handle_syscall_trap (struct lwp_info *lp, int stopping) | |
1784 | { | |
1785 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
1786 | struct gdbarch *gdbarch = target_thread_architecture (lp->ptid); | |
5b6d1e4f | 1787 | thread_info *thread = find_thread_ptid (linux_target, lp->ptid); |
00431a78 | 1788 | int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, thread); |
ca2163eb PA |
1789 | |
1790 | if (stopping) | |
1791 | { | |
1792 | /* If we're stopping threads, there's a SIGSTOP pending, which | |
1793 | makes it so that the LWP reports an immediate syscall return, | |
1794 | followed by the SIGSTOP. Skip seeing that "return" using | |
1795 | PTRACE_CONT directly, and let stop_wait_callback collect the | |
1796 | SIGSTOP. Later when the thread is resumed, a new syscall | |
1797 | entry event. If we didn't do this (and returned 0), we'd | |
1798 | leave a syscall entry pending, and our caller, by using | |
1799 | PTRACE_CONT to collect the SIGSTOP, skips the syscall return | |
1800 | itself. Later, when the user re-resumes this LWP, we'd see | |
1801 | another syscall entry event and we'd mistake it for a return. | |
1802 | ||
1803 | If stop_wait_callback didn't force the SIGSTOP out of the LWP | |
1804 | (leaving immediately with LWP->signalled set, without issuing | |
1805 | a PTRACE_CONT), it would still be problematic to leave this | |
1806 | syscall enter pending, as later when the thread is resumed, | |
1807 | it would then see the same syscall exit mentioned above, | |
1808 | followed by the delayed SIGSTOP, while the syscall didn't | |
1809 | actually get to execute. It seems it would be even more | |
1810 | confusing to the user. */ | |
1811 | ||
9327494e SM |
1812 | linux_nat_debug_printf |
1813 | ("ignoring syscall %d for LWP %ld (stopping threads), resuming with " | |
1814 | "PTRACE_CONT for SIGSTOP", syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1815 | |
1816 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
e38504b3 | 1817 | ptrace (PTRACE_CONT, lp->ptid.lwp (), 0, 0); |
8817a6f2 | 1818 | lp->stopped = 0; |
ca2163eb PA |
1819 | return 1; |
1820 | } | |
1821 | ||
bfd09d20 JS |
1822 | /* Always update the entry/return state, even if this particular |
1823 | syscall isn't interesting to the core now. In async mode, | |
1824 | the user could install a new catchpoint for this syscall | |
1825 | between syscall enter/return, and we'll need to know to | |
1826 | report a syscall return if that happens. */ | |
1827 | lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1828 | ? TARGET_WAITKIND_SYSCALL_RETURN | |
1829 | : TARGET_WAITKIND_SYSCALL_ENTRY); | |
1830 | ||
ca2163eb PA |
1831 | if (catch_syscall_enabled ()) |
1832 | { | |
ca2163eb PA |
1833 | if (catching_syscall_number (syscall_number)) |
1834 | { | |
1835 | /* Alright, an event to report. */ | |
1836 | ourstatus->kind = lp->syscall_state; | |
1837 | ourstatus->value.syscall_number = syscall_number; | |
1838 | ||
9327494e SM |
1839 | linux_nat_debug_printf |
1840 | ("stopping for %s of syscall %d for LWP %ld", | |
1841 | (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1842 | ? "entry" : "return"), syscall_number, lp->ptid.lwp ()); | |
1843 | ||
ca2163eb PA |
1844 | return 0; |
1845 | } | |
1846 | ||
9327494e SM |
1847 | linux_nat_debug_printf |
1848 | ("ignoring %s of syscall %d for LWP %ld", | |
1849 | (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1850 | ? "entry" : "return"), syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1851 | } |
1852 | else | |
1853 | { | |
1854 | /* If we had been syscall tracing, and hence used PT_SYSCALL | |
1855 | before on this LWP, it could happen that the user removes all | |
1856 | syscall catchpoints before we get to process this event. | |
1857 | There are two noteworthy issues here: | |
1858 | ||
1859 | - When stopped at a syscall entry event, resuming with | |
1860 | PT_STEP still resumes executing the syscall and reports a | |
1861 | syscall return. | |
1862 | ||
1863 | - Only PT_SYSCALL catches syscall enters. If we last | |
1864 | single-stepped this thread, then this event can't be a | |
1865 | syscall enter. If we last single-stepped this thread, this | |
1866 | has to be a syscall exit. | |
1867 | ||
1868 | The points above mean that the next resume, be it PT_STEP or | |
1869 | PT_CONTINUE, can not trigger a syscall trace event. */ | |
9327494e SM |
1870 | linux_nat_debug_printf |
1871 | ("caught syscall event with no syscall catchpoints. %d for LWP %ld, " | |
1872 | "ignoring", syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1873 | lp->syscall_state = TARGET_WAITKIND_IGNORE; |
1874 | } | |
1875 | ||
1876 | /* The core isn't interested in this event. For efficiency, avoid | |
1877 | stopping all threads only to have the core resume them all again. | |
1878 | Since we're not stopping threads, if we're still syscall tracing | |
1879 | and not stepping, we can't use PTRACE_CONT here, as we'd miss any | |
1880 | subsequent syscall. Simply resume using the inf-ptrace layer, | |
1881 | which knows when to use PT_SYSCALL or PT_CONTINUE. */ | |
1882 | ||
8a99810d | 1883 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
ca2163eb PA |
1884 | return 1; |
1885 | } | |
1886 | ||
3d799a95 DJ |
1887 | /* Handle a GNU/Linux extended wait response. If we see a clone |
1888 | event, we need to add the new LWP to our list (and not report the | |
1889 | trap to higher layers). This function returns non-zero if the | |
1890 | event should be ignored and we should wait again. If STOPPING is | |
1891 | true, the new LWP remains stopped, otherwise it is continued. */ | |
d6b0e80f AC |
1892 | |
1893 | static int | |
4dd63d48 | 1894 | linux_handle_extended_wait (struct lwp_info *lp, int status) |
d6b0e80f | 1895 | { |
e38504b3 | 1896 | int pid = lp->ptid.lwp (); |
3d799a95 | 1897 | struct target_waitstatus *ourstatus = &lp->waitstatus; |
89a5711c | 1898 | int event = linux_ptrace_get_extended_event (status); |
d6b0e80f | 1899 | |
bfd09d20 JS |
1900 | /* All extended events we currently use are mid-syscall. Only |
1901 | PTRACE_EVENT_STOP is delivered more like a signal-stop, but | |
1902 | you have to be using PTRACE_SEIZE to get that. */ | |
1903 | lp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY; | |
1904 | ||
3d799a95 DJ |
1905 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
1906 | || event == PTRACE_EVENT_CLONE) | |
d6b0e80f | 1907 | { |
3d799a95 DJ |
1908 | unsigned long new_pid; |
1909 | int ret; | |
1910 | ||
1911 | ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); | |
6fc19103 | 1912 | |
3d799a95 DJ |
1913 | /* If we haven't already seen the new PID stop, wait for it now. */ |
1914 | if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
1915 | { | |
1916 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
1917 | hits the SIGSTOP, but we're already attached. */ | |
4a6ed09b | 1918 | ret = my_waitpid (new_pid, &status, __WALL); |
3d799a95 DJ |
1919 | if (ret == -1) |
1920 | perror_with_name (_("waiting for new child")); | |
1921 | else if (ret != new_pid) | |
1922 | internal_error (__FILE__, __LINE__, | |
1923 | _("wait returned unexpected PID %d"), ret); | |
1924 | else if (!WIFSTOPPED (status)) | |
1925 | internal_error (__FILE__, __LINE__, | |
1926 | _("wait returned unexpected status 0x%x"), status); | |
1927 | } | |
1928 | ||
fd79271b | 1929 | ourstatus->value.related_pid = ptid_t (new_pid, new_pid, 0); |
3d799a95 | 1930 | |
26cb8b7c PA |
1931 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) |
1932 | { | |
1933 | /* The arch-specific native code may need to know about new | |
1934 | forks even if those end up never mapped to an | |
1935 | inferior. */ | |
135340af | 1936 | linux_target->low_new_fork (lp, new_pid); |
26cb8b7c | 1937 | } |
1310c1b0 PFC |
1938 | else if (event == PTRACE_EVENT_CLONE) |
1939 | { | |
1940 | linux_target->low_new_clone (lp, new_pid); | |
1941 | } | |
26cb8b7c | 1942 | |
2277426b | 1943 | if (event == PTRACE_EVENT_FORK |
e99b03dc | 1944 | && linux_fork_checkpointing_p (lp->ptid.pid ())) |
2277426b | 1945 | { |
2277426b PA |
1946 | /* Handle checkpointing by linux-fork.c here as a special |
1947 | case. We don't want the follow-fork-mode or 'catch fork' | |
1948 | to interfere with this. */ | |
1949 | ||
1950 | /* This won't actually modify the breakpoint list, but will | |
1951 | physically remove the breakpoints from the child. */ | |
fd79271b | 1952 | detach_breakpoints (ptid_t (new_pid, new_pid, 0)); |
2277426b PA |
1953 | |
1954 | /* Retain child fork in ptrace (stopped) state. */ | |
14571dad MS |
1955 | if (!find_fork_pid (new_pid)) |
1956 | add_fork (new_pid); | |
2277426b PA |
1957 | |
1958 | /* Report as spurious, so that infrun doesn't want to follow | |
1959 | this fork. We're actually doing an infcall in | |
1960 | linux-fork.c. */ | |
1961 | ourstatus->kind = TARGET_WAITKIND_SPURIOUS; | |
2277426b PA |
1962 | |
1963 | /* Report the stop to the core. */ | |
1964 | return 0; | |
1965 | } | |
1966 | ||
3d799a95 DJ |
1967 | if (event == PTRACE_EVENT_FORK) |
1968 | ourstatus->kind = TARGET_WAITKIND_FORKED; | |
1969 | else if (event == PTRACE_EVENT_VFORK) | |
1970 | ourstatus->kind = TARGET_WAITKIND_VFORKED; | |
4dd63d48 | 1971 | else if (event == PTRACE_EVENT_CLONE) |
3d799a95 | 1972 | { |
78768c4a JK |
1973 | struct lwp_info *new_lp; |
1974 | ||
3d799a95 | 1975 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
78768c4a | 1976 | |
9327494e SM |
1977 | linux_nat_debug_printf |
1978 | ("Got clone event from LWP %d, new child is LWP %ld", pid, new_pid); | |
3c4d7e12 | 1979 | |
e99b03dc | 1980 | new_lp = add_lwp (ptid_t (lp->ptid.pid (), new_pid, 0)); |
4c28f408 | 1981 | new_lp->stopped = 1; |
4dd63d48 | 1982 | new_lp->resumed = 1; |
d6b0e80f | 1983 | |
2db9a427 PA |
1984 | /* If the thread_db layer is active, let it record the user |
1985 | level thread id and status, and add the thread to GDB's | |
1986 | list. */ | |
1987 | if (!thread_db_notice_clone (lp->ptid, new_lp->ptid)) | |
3d799a95 | 1988 | { |
2db9a427 PA |
1989 | /* The process is not using thread_db. Add the LWP to |
1990 | GDB's list. */ | |
e38504b3 | 1991 | target_post_attach (new_lp->ptid.lwp ()); |
5b6d1e4f | 1992 | add_thread (linux_target, new_lp->ptid); |
2db9a427 | 1993 | } |
4c28f408 | 1994 | |
2ee52aa4 | 1995 | /* Even if we're stopping the thread for some reason |
4dd63d48 PA |
1996 | internal to this module, from the perspective of infrun |
1997 | and the user/frontend, this new thread is running until | |
1998 | it next reports a stop. */ | |
719546c4 SM |
1999 | set_running (linux_target, new_lp->ptid, true); |
2000 | set_executing (linux_target, new_lp->ptid, true); | |
4c28f408 | 2001 | |
4dd63d48 | 2002 | if (WSTOPSIG (status) != SIGSTOP) |
79395f92 | 2003 | { |
4dd63d48 PA |
2004 | /* This can happen if someone starts sending signals to |
2005 | the new thread before it gets a chance to run, which | |
2006 | have a lower number than SIGSTOP (e.g. SIGUSR1). | |
2007 | This is an unlikely case, and harder to handle for | |
2008 | fork / vfork than for clone, so we do not try - but | |
2009 | we handle it for clone events here. */ | |
2010 | ||
2011 | new_lp->signalled = 1; | |
2012 | ||
79395f92 PA |
2013 | /* We created NEW_LP so it cannot yet contain STATUS. */ |
2014 | gdb_assert (new_lp->status == 0); | |
2015 | ||
2016 | /* Save the wait status to report later. */ | |
9327494e SM |
2017 | linux_nat_debug_printf |
2018 | ("waitpid of new LWP %ld, saving status %s", | |
2019 | (long) new_lp->ptid.lwp (), status_to_str (status)); | |
79395f92 PA |
2020 | new_lp->status = status; |
2021 | } | |
aa01bd36 PA |
2022 | else if (report_thread_events) |
2023 | { | |
2024 | new_lp->waitstatus.kind = TARGET_WAITKIND_THREAD_CREATED; | |
2025 | new_lp->status = status; | |
2026 | } | |
79395f92 | 2027 | |
3d799a95 DJ |
2028 | return 1; |
2029 | } | |
2030 | ||
2031 | return 0; | |
d6b0e80f AC |
2032 | } |
2033 | ||
3d799a95 DJ |
2034 | if (event == PTRACE_EVENT_EXEC) |
2035 | { | |
9327494e | 2036 | linux_nat_debug_printf ("Got exec event from LWP %ld", lp->ptid.lwp ()); |
a75724bc | 2037 | |
3d799a95 DJ |
2038 | ourstatus->kind = TARGET_WAITKIND_EXECD; |
2039 | ourstatus->value.execd_pathname | |
f6ac5f3d | 2040 | = xstrdup (linux_proc_pid_to_exec_file (pid)); |
3d799a95 | 2041 | |
8af756ef PA |
2042 | /* The thread that execed must have been resumed, but, when a |
2043 | thread execs, it changes its tid to the tgid, and the old | |
2044 | tgid thread might have not been resumed. */ | |
2045 | lp->resumed = 1; | |
6c95b8df PA |
2046 | return 0; |
2047 | } | |
2048 | ||
2049 | if (event == PTRACE_EVENT_VFORK_DONE) | |
2050 | { | |
2051 | if (current_inferior ()->waiting_for_vfork_done) | |
3d799a95 | 2052 | { |
9327494e SM |
2053 | linux_nat_debug_printf |
2054 | ("Got expected PTRACE_EVENT_VFORK_DONE from LWP %ld: stopping", | |
2055 | lp->ptid.lwp ()); | |
3d799a95 | 2056 | |
6c95b8df PA |
2057 | ourstatus->kind = TARGET_WAITKIND_VFORK_DONE; |
2058 | return 0; | |
3d799a95 DJ |
2059 | } |
2060 | ||
9327494e SM |
2061 | linux_nat_debug_printf |
2062 | ("Got PTRACE_EVENT_VFORK_DONE from LWP %ld: ignoring", lp->ptid.lwp ()); | |
2063 | ||
6c95b8df | 2064 | return 1; |
3d799a95 DJ |
2065 | } |
2066 | ||
2067 | internal_error (__FILE__, __LINE__, | |
2068 | _("unknown ptrace event %d"), event); | |
d6b0e80f AC |
2069 | } |
2070 | ||
9c3a5d93 PA |
2071 | /* Suspend waiting for a signal. We're mostly interested in |
2072 | SIGCHLD/SIGINT. */ | |
2073 | ||
2074 | static void | |
2075 | wait_for_signal () | |
2076 | { | |
9327494e | 2077 | linux_nat_debug_printf ("about to sigsuspend"); |
9c3a5d93 PA |
2078 | sigsuspend (&suspend_mask); |
2079 | ||
2080 | /* If the quit flag is set, it means that the user pressed Ctrl-C | |
2081 | and we're debugging a process that is running on a separate | |
2082 | terminal, so we must forward the Ctrl-C to the inferior. (If the | |
2083 | inferior is sharing GDB's terminal, then the Ctrl-C reaches the | |
2084 | inferior directly.) We must do this here because functions that | |
2085 | need to block waiting for a signal loop forever until there's an | |
2086 | event to report before returning back to the event loop. */ | |
2087 | if (!target_terminal::is_ours ()) | |
2088 | { | |
2089 | if (check_quit_flag ()) | |
2090 | target_pass_ctrlc (); | |
2091 | } | |
2092 | } | |
2093 | ||
d6b0e80f AC |
2094 | /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has |
2095 | exited. */ | |
2096 | ||
2097 | static int | |
2098 | wait_lwp (struct lwp_info *lp) | |
2099 | { | |
2100 | pid_t pid; | |
432b4d03 | 2101 | int status = 0; |
d6b0e80f | 2102 | int thread_dead = 0; |
432b4d03 | 2103 | sigset_t prev_mask; |
d6b0e80f AC |
2104 | |
2105 | gdb_assert (!lp->stopped); | |
2106 | gdb_assert (lp->status == 0); | |
2107 | ||
432b4d03 JK |
2108 | /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
2109 | block_child_signals (&prev_mask); | |
2110 | ||
2111 | for (;;) | |
d6b0e80f | 2112 | { |
e38504b3 | 2113 | pid = my_waitpid (lp->ptid.lwp (), &status, __WALL | WNOHANG); |
a9f4bb21 PA |
2114 | if (pid == -1 && errno == ECHILD) |
2115 | { | |
2116 | /* The thread has previously exited. We need to delete it | |
4a6ed09b PA |
2117 | now because if this was a non-leader thread execing, we |
2118 | won't get an exit event. See comments on exec events at | |
2119 | the top of the file. */ | |
a9f4bb21 | 2120 | thread_dead = 1; |
9327494e SM |
2121 | linux_nat_debug_printf ("%s vanished.", |
2122 | target_pid_to_str (lp->ptid).c_str ()); | |
a9f4bb21 | 2123 | } |
432b4d03 JK |
2124 | if (pid != 0) |
2125 | break; | |
2126 | ||
2127 | /* Bugs 10970, 12702. | |
2128 | Thread group leader may have exited in which case we'll lock up in | |
2129 | waitpid if there are other threads, even if they are all zombies too. | |
2130 | Basically, we're not supposed to use waitpid this way. | |
4a6ed09b PA |
2131 | tkill(pid,0) cannot be used here as it gets ESRCH for both |
2132 | for zombie and running processes. | |
432b4d03 JK |
2133 | |
2134 | As a workaround, check if we're waiting for the thread group leader and | |
2135 | if it's a zombie, and avoid calling waitpid if it is. | |
2136 | ||
2137 | This is racy, what if the tgl becomes a zombie right after we check? | |
2138 | Therefore always use WNOHANG with sigsuspend - it is equivalent to | |
5f572dec | 2139 | waiting waitpid but linux_proc_pid_is_zombie is safe this way. */ |
432b4d03 | 2140 | |
e38504b3 TT |
2141 | if (lp->ptid.pid () == lp->ptid.lwp () |
2142 | && linux_proc_pid_is_zombie (lp->ptid.lwp ())) | |
d6b0e80f | 2143 | { |
d6b0e80f | 2144 | thread_dead = 1; |
9327494e SM |
2145 | linux_nat_debug_printf ("Thread group leader %s vanished.", |
2146 | target_pid_to_str (lp->ptid).c_str ()); | |
432b4d03 | 2147 | break; |
d6b0e80f | 2148 | } |
432b4d03 JK |
2149 | |
2150 | /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers | |
2151 | get invoked despite our caller had them intentionally blocked by | |
2152 | block_child_signals. This is sensitive only to the loop of | |
2153 | linux_nat_wait_1 and there if we get called my_waitpid gets called | |
2154 | again before it gets to sigsuspend so we can safely let the handlers | |
2155 | get executed here. */ | |
9c3a5d93 | 2156 | wait_for_signal (); |
432b4d03 JK |
2157 | } |
2158 | ||
2159 | restore_child_signals_mask (&prev_mask); | |
2160 | ||
d6b0e80f AC |
2161 | if (!thread_dead) |
2162 | { | |
e38504b3 | 2163 | gdb_assert (pid == lp->ptid.lwp ()); |
d6b0e80f | 2164 | |
9327494e | 2165 | linux_nat_debug_printf ("waitpid %s received %s", |
a068643d | 2166 | target_pid_to_str (lp->ptid).c_str (), |
d6b0e80f | 2167 | status_to_str (status)); |
d6b0e80f | 2168 | |
a9f4bb21 PA |
2169 | /* Check if the thread has exited. */ |
2170 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
2171 | { | |
aa01bd36 | 2172 | if (report_thread_events |
e38504b3 | 2173 | || lp->ptid.pid () == lp->ptid.lwp ()) |
69dde7dc | 2174 | { |
9327494e | 2175 | linux_nat_debug_printf ("LWP %d exited.", lp->ptid.pid ()); |
69dde7dc | 2176 | |
aa01bd36 | 2177 | /* If this is the leader exiting, it means the whole |
69dde7dc PA |
2178 | process is gone. Store the status to report to the |
2179 | core. Store it in lp->waitstatus, because lp->status | |
2180 | would be ambiguous (W_EXITCODE(0,0) == 0). */ | |
2181 | store_waitstatus (&lp->waitstatus, status); | |
2182 | return 0; | |
2183 | } | |
2184 | ||
a9f4bb21 | 2185 | thread_dead = 1; |
9327494e SM |
2186 | linux_nat_debug_printf ("%s exited.", |
2187 | target_pid_to_str (lp->ptid).c_str ()); | |
a9f4bb21 | 2188 | } |
d6b0e80f AC |
2189 | } |
2190 | ||
2191 | if (thread_dead) | |
2192 | { | |
e26af52f | 2193 | exit_lwp (lp); |
d6b0e80f AC |
2194 | return 0; |
2195 | } | |
2196 | ||
2197 | gdb_assert (WIFSTOPPED (status)); | |
8817a6f2 | 2198 | lp->stopped = 1; |
d6b0e80f | 2199 | |
8784d563 PA |
2200 | if (lp->must_set_ptrace_flags) |
2201 | { | |
5b6d1e4f | 2202 | inferior *inf = find_inferior_pid (linux_target, lp->ptid.pid ()); |
de0d863e | 2203 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 2204 | |
e38504b3 | 2205 | linux_enable_event_reporting (lp->ptid.lwp (), options); |
8784d563 PA |
2206 | lp->must_set_ptrace_flags = 0; |
2207 | } | |
2208 | ||
ca2163eb PA |
2209 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2210 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2211 | { | |
2212 | /* No longer need the sysgood bit. The ptrace event ends up | |
2213 | recorded in lp->waitstatus if we care for it. We can carry | |
2214 | on handling the event like a regular SIGTRAP from here | |
2215 | on. */ | |
2216 | status = W_STOPCODE (SIGTRAP); | |
2217 | if (linux_handle_syscall_trap (lp, 1)) | |
2218 | return wait_lwp (lp); | |
2219 | } | |
bfd09d20 JS |
2220 | else |
2221 | { | |
2222 | /* Almost all other ptrace-stops are known to be outside of system | |
2223 | calls, with further exceptions in linux_handle_extended_wait. */ | |
2224 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2225 | } | |
ca2163eb | 2226 | |
d6b0e80f | 2227 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2228 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2229 | && linux_is_extended_waitstatus (status)) | |
d6b0e80f | 2230 | { |
9327494e | 2231 | linux_nat_debug_printf ("Handling extended status 0x%06x", status); |
4dd63d48 | 2232 | linux_handle_extended_wait (lp, status); |
20ba1ce6 | 2233 | return 0; |
d6b0e80f AC |
2234 | } |
2235 | ||
2236 | return status; | |
2237 | } | |
2238 | ||
2239 | /* Send a SIGSTOP to LP. */ | |
2240 | ||
2241 | static int | |
d3a70e03 | 2242 | stop_callback (struct lwp_info *lp) |
d6b0e80f AC |
2243 | { |
2244 | if (!lp->stopped && !lp->signalled) | |
2245 | { | |
2246 | int ret; | |
2247 | ||
9327494e | 2248 | linux_nat_debug_printf ("kill %s **<SIGSTOP>**", |
a068643d | 2249 | target_pid_to_str (lp->ptid).c_str ()); |
9327494e | 2250 | |
d6b0e80f | 2251 | errno = 0; |
e38504b3 | 2252 | ret = kill_lwp (lp->ptid.lwp (), SIGSTOP); |
9327494e | 2253 | linux_nat_debug_printf ("lwp kill %d %s", ret, |
d6b0e80f | 2254 | errno ? safe_strerror (errno) : "ERRNO-OK"); |
d6b0e80f AC |
2255 | |
2256 | lp->signalled = 1; | |
2257 | gdb_assert (lp->status == 0); | |
2258 | } | |
2259 | ||
2260 | return 0; | |
2261 | } | |
2262 | ||
7b50312a PA |
2263 | /* Request a stop on LWP. */ |
2264 | ||
2265 | void | |
2266 | linux_stop_lwp (struct lwp_info *lwp) | |
2267 | { | |
d3a70e03 | 2268 | stop_callback (lwp); |
7b50312a PA |
2269 | } |
2270 | ||
2db9a427 PA |
2271 | /* See linux-nat.h */ |
2272 | ||
2273 | void | |
2274 | linux_stop_and_wait_all_lwps (void) | |
2275 | { | |
2276 | /* Stop all LWP's ... */ | |
d3a70e03 | 2277 | iterate_over_lwps (minus_one_ptid, stop_callback); |
2db9a427 PA |
2278 | |
2279 | /* ... and wait until all of them have reported back that | |
2280 | they're no longer running. */ | |
d3a70e03 | 2281 | iterate_over_lwps (minus_one_ptid, stop_wait_callback); |
2db9a427 PA |
2282 | } |
2283 | ||
2284 | /* See linux-nat.h */ | |
2285 | ||
2286 | void | |
2287 | linux_unstop_all_lwps (void) | |
2288 | { | |
2289 | iterate_over_lwps (minus_one_ptid, | |
d3a70e03 TT |
2290 | [] (struct lwp_info *info) |
2291 | { | |
2292 | return resume_stopped_resumed_lwps (info, minus_one_ptid); | |
2293 | }); | |
2db9a427 PA |
2294 | } |
2295 | ||
57380f4e | 2296 | /* Return non-zero if LWP PID has a pending SIGINT. */ |
d6b0e80f AC |
2297 | |
2298 | static int | |
57380f4e DJ |
2299 | linux_nat_has_pending_sigint (int pid) |
2300 | { | |
2301 | sigset_t pending, blocked, ignored; | |
57380f4e DJ |
2302 | |
2303 | linux_proc_pending_signals (pid, &pending, &blocked, &ignored); | |
2304 | ||
2305 | if (sigismember (&pending, SIGINT) | |
2306 | && !sigismember (&ignored, SIGINT)) | |
2307 | return 1; | |
2308 | ||
2309 | return 0; | |
2310 | } | |
2311 | ||
2312 | /* Set a flag in LP indicating that we should ignore its next SIGINT. */ | |
2313 | ||
2314 | static int | |
d3a70e03 | 2315 | set_ignore_sigint (struct lwp_info *lp) |
d6b0e80f | 2316 | { |
57380f4e DJ |
2317 | /* If a thread has a pending SIGINT, consume it; otherwise, set a |
2318 | flag to consume the next one. */ | |
2319 | if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) | |
2320 | && WSTOPSIG (lp->status) == SIGINT) | |
2321 | lp->status = 0; | |
2322 | else | |
2323 | lp->ignore_sigint = 1; | |
2324 | ||
2325 | return 0; | |
2326 | } | |
2327 | ||
2328 | /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. | |
2329 | This function is called after we know the LWP has stopped; if the LWP | |
2330 | stopped before the expected SIGINT was delivered, then it will never have | |
2331 | arrived. Also, if the signal was delivered to a shared queue and consumed | |
2332 | by a different thread, it will never be delivered to this LWP. */ | |
d6b0e80f | 2333 | |
57380f4e DJ |
2334 | static void |
2335 | maybe_clear_ignore_sigint (struct lwp_info *lp) | |
2336 | { | |
2337 | if (!lp->ignore_sigint) | |
2338 | return; | |
2339 | ||
e38504b3 | 2340 | if (!linux_nat_has_pending_sigint (lp->ptid.lwp ())) |
57380f4e | 2341 | { |
9327494e SM |
2342 | linux_nat_debug_printf ("Clearing bogus flag for %s", |
2343 | target_pid_to_str (lp->ptid).c_str ()); | |
57380f4e DJ |
2344 | lp->ignore_sigint = 0; |
2345 | } | |
2346 | } | |
2347 | ||
ebec9a0f PA |
2348 | /* Fetch the possible triggered data watchpoint info and store it in |
2349 | LP. | |
2350 | ||
2351 | On some archs, like x86, that use debug registers to set | |
2352 | watchpoints, it's possible that the way to know which watched | |
2353 | address trapped, is to check the register that is used to select | |
2354 | which address to watch. Problem is, between setting the watchpoint | |
2355 | and reading back which data address trapped, the user may change | |
2356 | the set of watchpoints, and, as a consequence, GDB changes the | |
2357 | debug registers in the inferior. To avoid reading back a stale | |
2358 | stopped-data-address when that happens, we cache in LP the fact | |
2359 | that a watchpoint trapped, and the corresponding data address, as | |
2360 | soon as we see LP stop with a SIGTRAP. If GDB changes the debug | |
2361 | registers meanwhile, we have the cached data we can rely on. */ | |
2362 | ||
9c02b525 PA |
2363 | static int |
2364 | check_stopped_by_watchpoint (struct lwp_info *lp) | |
ebec9a0f | 2365 | { |
2989a365 | 2366 | scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); |
ebec9a0f PA |
2367 | inferior_ptid = lp->ptid; |
2368 | ||
f6ac5f3d | 2369 | if (linux_target->low_stopped_by_watchpoint ()) |
ebec9a0f | 2370 | { |
15c66dd6 | 2371 | lp->stop_reason = TARGET_STOPPED_BY_WATCHPOINT; |
f6ac5f3d PA |
2372 | lp->stopped_data_address_p |
2373 | = linux_target->low_stopped_data_address (&lp->stopped_data_address); | |
ebec9a0f PA |
2374 | } |
2375 | ||
15c66dd6 | 2376 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
9c02b525 PA |
2377 | } |
2378 | ||
9c02b525 | 2379 | /* Returns true if the LWP had stopped for a watchpoint. */ |
ebec9a0f | 2380 | |
57810aa7 | 2381 | bool |
f6ac5f3d | 2382 | linux_nat_target::stopped_by_watchpoint () |
ebec9a0f PA |
2383 | { |
2384 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2385 | ||
2386 | gdb_assert (lp != NULL); | |
2387 | ||
15c66dd6 | 2388 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
ebec9a0f PA |
2389 | } |
2390 | ||
57810aa7 | 2391 | bool |
f6ac5f3d | 2392 | linux_nat_target::stopped_data_address (CORE_ADDR *addr_p) |
ebec9a0f PA |
2393 | { |
2394 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2395 | ||
2396 | gdb_assert (lp != NULL); | |
2397 | ||
2398 | *addr_p = lp->stopped_data_address; | |
2399 | ||
2400 | return lp->stopped_data_address_p; | |
2401 | } | |
2402 | ||
26ab7092 JK |
2403 | /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
2404 | ||
135340af PA |
2405 | bool |
2406 | linux_nat_target::low_status_is_event (int status) | |
26ab7092 JK |
2407 | { |
2408 | return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; | |
2409 | } | |
2410 | ||
57380f4e DJ |
2411 | /* Wait until LP is stopped. */ |
2412 | ||
2413 | static int | |
d3a70e03 | 2414 | stop_wait_callback (struct lwp_info *lp) |
57380f4e | 2415 | { |
5b6d1e4f | 2416 | inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
6c95b8df PA |
2417 | |
2418 | /* If this is a vfork parent, bail out, it is not going to report | |
2419 | any SIGSTOP until the vfork is done with. */ | |
2420 | if (inf->vfork_child != NULL) | |
2421 | return 0; | |
2422 | ||
d6b0e80f AC |
2423 | if (!lp->stopped) |
2424 | { | |
2425 | int status; | |
2426 | ||
2427 | status = wait_lwp (lp); | |
2428 | if (status == 0) | |
2429 | return 0; | |
2430 | ||
57380f4e DJ |
2431 | if (lp->ignore_sigint && WIFSTOPPED (status) |
2432 | && WSTOPSIG (status) == SIGINT) | |
d6b0e80f | 2433 | { |
57380f4e | 2434 | lp->ignore_sigint = 0; |
d6b0e80f AC |
2435 | |
2436 | errno = 0; | |
e38504b3 | 2437 | ptrace (PTRACE_CONT, lp->ptid.lwp (), 0, 0); |
8817a6f2 | 2438 | lp->stopped = 0; |
9327494e SM |
2439 | linux_nat_debug_printf |
2440 | ("PTRACE_CONT %s, 0, 0 (%s) (discarding SIGINT)", | |
2441 | target_pid_to_str (lp->ptid).c_str (), | |
2442 | errno ? safe_strerror (errno) : "OK"); | |
d6b0e80f | 2443 | |
d3a70e03 | 2444 | return stop_wait_callback (lp); |
d6b0e80f AC |
2445 | } |
2446 | ||
57380f4e DJ |
2447 | maybe_clear_ignore_sigint (lp); |
2448 | ||
d6b0e80f AC |
2449 | if (WSTOPSIG (status) != SIGSTOP) |
2450 | { | |
e5ef252a | 2451 | /* The thread was stopped with a signal other than SIGSTOP. */ |
7feb7d06 | 2452 | |
9327494e SM |
2453 | linux_nat_debug_printf ("Pending event %s in %s", |
2454 | status_to_str ((int) status), | |
2455 | target_pid_to_str (lp->ptid).c_str ()); | |
e5ef252a PA |
2456 | |
2457 | /* Save the sigtrap event. */ | |
2458 | lp->status = status; | |
e5ef252a | 2459 | gdb_assert (lp->signalled); |
e7ad2f14 | 2460 | save_stop_reason (lp); |
d6b0e80f AC |
2461 | } |
2462 | else | |
2463 | { | |
7010835a | 2464 | /* We caught the SIGSTOP that we intended to catch. */ |
e5ef252a | 2465 | |
9327494e SM |
2466 | linux_nat_debug_printf ("Expected SIGSTOP caught for %s.", |
2467 | target_pid_to_str (lp->ptid).c_str ()); | |
e5ef252a | 2468 | |
d6b0e80f | 2469 | lp->signalled = 0; |
7010835a AB |
2470 | |
2471 | /* If we are waiting for this stop so we can report the thread | |
2472 | stopped then we need to record this status. Otherwise, we can | |
2473 | now discard this stop event. */ | |
2474 | if (lp->last_resume_kind == resume_stop) | |
2475 | { | |
2476 | lp->status = status; | |
2477 | save_stop_reason (lp); | |
2478 | } | |
d6b0e80f AC |
2479 | } |
2480 | } | |
2481 | ||
2482 | return 0; | |
2483 | } | |
2484 | ||
9c02b525 PA |
2485 | /* Return non-zero if LP has a wait status pending. Discard the |
2486 | pending event and resume the LWP if the event that originally | |
2487 | caused the stop became uninteresting. */ | |
d6b0e80f AC |
2488 | |
2489 | static int | |
d3a70e03 | 2490 | status_callback (struct lwp_info *lp) |
d6b0e80f AC |
2491 | { |
2492 | /* Only report a pending wait status if we pretend that this has | |
2493 | indeed been resumed. */ | |
ca2163eb PA |
2494 | if (!lp->resumed) |
2495 | return 0; | |
2496 | ||
eb54c8bf PA |
2497 | if (!lwp_status_pending_p (lp)) |
2498 | return 0; | |
2499 | ||
15c66dd6 PA |
2500 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
2501 | || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) | |
9c02b525 | 2502 | { |
5b6d1e4f | 2503 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
9c02b525 PA |
2504 | CORE_ADDR pc; |
2505 | int discard = 0; | |
2506 | ||
9c02b525 PA |
2507 | pc = regcache_read_pc (regcache); |
2508 | ||
2509 | if (pc != lp->stop_pc) | |
2510 | { | |
9327494e SM |
2511 | linux_nat_debug_printf ("PC of %s changed. was=%s, now=%s", |
2512 | target_pid_to_str (lp->ptid).c_str (), | |
2513 | paddress (target_gdbarch (), lp->stop_pc), | |
2514 | paddress (target_gdbarch (), pc)); | |
9c02b525 PA |
2515 | discard = 1; |
2516 | } | |
faf09f01 PA |
2517 | |
2518 | #if !USE_SIGTRAP_SIGINFO | |
a01bda52 | 2519 | else if (!breakpoint_inserted_here_p (regcache->aspace (), pc)) |
9c02b525 | 2520 | { |
9327494e SM |
2521 | linux_nat_debug_printf ("previous breakpoint of %s, at %s gone", |
2522 | target_pid_to_str (lp->ptid).c_str (), | |
2523 | paddress (target_gdbarch (), lp->stop_pc)); | |
9c02b525 PA |
2524 | |
2525 | discard = 1; | |
2526 | } | |
faf09f01 | 2527 | #endif |
9c02b525 PA |
2528 | |
2529 | if (discard) | |
2530 | { | |
9327494e SM |
2531 | linux_nat_debug_printf ("pending event of %s cancelled.", |
2532 | target_pid_to_str (lp->ptid).c_str ()); | |
9c02b525 PA |
2533 | |
2534 | lp->status = 0; | |
2535 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); | |
2536 | return 0; | |
2537 | } | |
9c02b525 PA |
2538 | } |
2539 | ||
eb54c8bf | 2540 | return 1; |
d6b0e80f AC |
2541 | } |
2542 | ||
d6b0e80f AC |
2543 | /* Count the LWP's that have had events. */ |
2544 | ||
2545 | static int | |
d3a70e03 | 2546 | count_events_callback (struct lwp_info *lp, int *count) |
d6b0e80f | 2547 | { |
d6b0e80f AC |
2548 | gdb_assert (count != NULL); |
2549 | ||
9c02b525 PA |
2550 | /* Select only resumed LWPs that have an event pending. */ |
2551 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2552 | (*count)++; |
2553 | ||
2554 | return 0; | |
2555 | } | |
2556 | ||
2557 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
2558 | ||
2559 | static int | |
d3a70e03 | 2560 | select_singlestep_lwp_callback (struct lwp_info *lp) |
d6b0e80f | 2561 | { |
25289eb2 PA |
2562 | if (lp->last_resume_kind == resume_step |
2563 | && lp->status != 0) | |
d6b0e80f AC |
2564 | return 1; |
2565 | else | |
2566 | return 0; | |
2567 | } | |
2568 | ||
8a99810d PA |
2569 | /* Returns true if LP has a status pending. */ |
2570 | ||
2571 | static int | |
2572 | lwp_status_pending_p (struct lwp_info *lp) | |
2573 | { | |
2574 | /* We check for lp->waitstatus in addition to lp->status, because we | |
2575 | can have pending process exits recorded in lp->status and | |
2576 | W_EXITCODE(0,0) happens to be 0. */ | |
2577 | return lp->status != 0 || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE; | |
2578 | } | |
2579 | ||
b90fc188 | 2580 | /* Select the Nth LWP that has had an event. */ |
d6b0e80f AC |
2581 | |
2582 | static int | |
d3a70e03 | 2583 | select_event_lwp_callback (struct lwp_info *lp, int *selector) |
d6b0e80f | 2584 | { |
d6b0e80f AC |
2585 | gdb_assert (selector != NULL); |
2586 | ||
9c02b525 PA |
2587 | /* Select only resumed LWPs that have an event pending. */ |
2588 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2589 | if ((*selector)-- == 0) |
2590 | return 1; | |
2591 | ||
2592 | return 0; | |
2593 | } | |
2594 | ||
e7ad2f14 PA |
2595 | /* Called when the LWP stopped for a signal/trap. If it stopped for a |
2596 | trap check what caused it (breakpoint, watchpoint, trace, etc.), | |
2597 | and save the result in the LWP's stop_reason field. If it stopped | |
2598 | for a breakpoint, decrement the PC if necessary on the lwp's | |
2599 | architecture. */ | |
9c02b525 | 2600 | |
e7ad2f14 PA |
2601 | static void |
2602 | save_stop_reason (struct lwp_info *lp) | |
710151dd | 2603 | { |
e7ad2f14 PA |
2604 | struct regcache *regcache; |
2605 | struct gdbarch *gdbarch; | |
515630c5 | 2606 | CORE_ADDR pc; |
9c02b525 | 2607 | CORE_ADDR sw_bp_pc; |
faf09f01 PA |
2608 | #if USE_SIGTRAP_SIGINFO |
2609 | siginfo_t siginfo; | |
2610 | #endif | |
9c02b525 | 2611 | |
e7ad2f14 PA |
2612 | gdb_assert (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON); |
2613 | gdb_assert (lp->status != 0); | |
2614 | ||
135340af | 2615 | if (!linux_target->low_status_is_event (lp->status)) |
e7ad2f14 PA |
2616 | return; |
2617 | ||
5b6d1e4f | 2618 | regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 2619 | gdbarch = regcache->arch (); |
e7ad2f14 | 2620 | |
9c02b525 | 2621 | pc = regcache_read_pc (regcache); |
527a273a | 2622 | sw_bp_pc = pc - gdbarch_decr_pc_after_break (gdbarch); |
515630c5 | 2623 | |
faf09f01 PA |
2624 | #if USE_SIGTRAP_SIGINFO |
2625 | if (linux_nat_get_siginfo (lp->ptid, &siginfo)) | |
2626 | { | |
2627 | if (siginfo.si_signo == SIGTRAP) | |
2628 | { | |
e7ad2f14 PA |
2629 | if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code) |
2630 | && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) | |
faf09f01 | 2631 | { |
e7ad2f14 PA |
2632 | /* The si_code is ambiguous on this arch -- check debug |
2633 | registers. */ | |
2634 | if (!check_stopped_by_watchpoint (lp)) | |
2635 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2636 | } | |
2637 | else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)) | |
2638 | { | |
2639 | /* If we determine the LWP stopped for a SW breakpoint, | |
2640 | trust it. Particularly don't check watchpoint | |
7da6a5b9 | 2641 | registers, because, at least on s390, we'd find |
e7ad2f14 PA |
2642 | stopped-by-watchpoint as long as there's a watchpoint |
2643 | set. */ | |
faf09f01 | 2644 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
faf09f01 | 2645 | } |
e7ad2f14 | 2646 | else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) |
faf09f01 | 2647 | { |
e7ad2f14 PA |
2648 | /* This can indicate either a hardware breakpoint or |
2649 | hardware watchpoint. Check debug registers. */ | |
2650 | if (!check_stopped_by_watchpoint (lp)) | |
2651 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; | |
faf09f01 | 2652 | } |
2bf6fb9d PA |
2653 | else if (siginfo.si_code == TRAP_TRACE) |
2654 | { | |
9327494e SM |
2655 | linux_nat_debug_printf ("%s stopped by trace", |
2656 | target_pid_to_str (lp->ptid).c_str ()); | |
e7ad2f14 PA |
2657 | |
2658 | /* We may have single stepped an instruction that | |
2659 | triggered a watchpoint. In that case, on some | |
2660 | architectures (such as x86), instead of TRAP_HWBKPT, | |
2661 | si_code indicates TRAP_TRACE, and we need to check | |
2662 | the debug registers separately. */ | |
2663 | check_stopped_by_watchpoint (lp); | |
2bf6fb9d | 2664 | } |
faf09f01 PA |
2665 | } |
2666 | } | |
2667 | #else | |
9c02b525 | 2668 | if ((!lp->step || lp->stop_pc == sw_bp_pc) |
a01bda52 | 2669 | && software_breakpoint_inserted_here_p (regcache->aspace (), |
9c02b525 | 2670 | sw_bp_pc)) |
710151dd | 2671 | { |
9c02b525 PA |
2672 | /* The LWP was either continued, or stepped a software |
2673 | breakpoint instruction. */ | |
e7ad2f14 PA |
2674 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
2675 | } | |
2676 | ||
a01bda52 | 2677 | if (hardware_breakpoint_inserted_here_p (regcache->aspace (), pc)) |
e7ad2f14 PA |
2678 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; |
2679 | ||
2680 | if (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON) | |
2681 | check_stopped_by_watchpoint (lp); | |
2682 | #endif | |
2683 | ||
2684 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT) | |
2685 | { | |
9327494e SM |
2686 | linux_nat_debug_printf ("%s stopped by software breakpoint", |
2687 | target_pid_to_str (lp->ptid).c_str ()); | |
710151dd PA |
2688 | |
2689 | /* Back up the PC if necessary. */ | |
9c02b525 PA |
2690 | if (pc != sw_bp_pc) |
2691 | regcache_write_pc (regcache, sw_bp_pc); | |
515630c5 | 2692 | |
e7ad2f14 PA |
2693 | /* Update this so we record the correct stop PC below. */ |
2694 | pc = sw_bp_pc; | |
710151dd | 2695 | } |
e7ad2f14 | 2696 | else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) |
9c02b525 | 2697 | { |
9327494e SM |
2698 | linux_nat_debug_printf ("%s stopped by hardware breakpoint", |
2699 | target_pid_to_str (lp->ptid).c_str ()); | |
e7ad2f14 PA |
2700 | } |
2701 | else if (lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT) | |
2702 | { | |
9327494e SM |
2703 | linux_nat_debug_printf ("%s stopped by hardware watchpoint", |
2704 | target_pid_to_str (lp->ptid).c_str ()); | |
9c02b525 | 2705 | } |
d6b0e80f | 2706 | |
e7ad2f14 | 2707 | lp->stop_pc = pc; |
d6b0e80f AC |
2708 | } |
2709 | ||
faf09f01 PA |
2710 | |
2711 | /* Returns true if the LWP had stopped for a software breakpoint. */ | |
2712 | ||
57810aa7 | 2713 | bool |
f6ac5f3d | 2714 | linux_nat_target::stopped_by_sw_breakpoint () |
faf09f01 PA |
2715 | { |
2716 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2717 | ||
2718 | gdb_assert (lp != NULL); | |
2719 | ||
2720 | return lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2721 | } | |
2722 | ||
2723 | /* Implement the supports_stopped_by_sw_breakpoint method. */ | |
2724 | ||
57810aa7 | 2725 | bool |
f6ac5f3d | 2726 | linux_nat_target::supports_stopped_by_sw_breakpoint () |
faf09f01 PA |
2727 | { |
2728 | return USE_SIGTRAP_SIGINFO; | |
2729 | } | |
2730 | ||
2731 | /* Returns true if the LWP had stopped for a hardware | |
2732 | breakpoint/watchpoint. */ | |
2733 | ||
57810aa7 | 2734 | bool |
f6ac5f3d | 2735 | linux_nat_target::stopped_by_hw_breakpoint () |
faf09f01 PA |
2736 | { |
2737 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2738 | ||
2739 | gdb_assert (lp != NULL); | |
2740 | ||
2741 | return lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT; | |
2742 | } | |
2743 | ||
2744 | /* Implement the supports_stopped_by_hw_breakpoint method. */ | |
2745 | ||
57810aa7 | 2746 | bool |
f6ac5f3d | 2747 | linux_nat_target::supports_stopped_by_hw_breakpoint () |
faf09f01 PA |
2748 | { |
2749 | return USE_SIGTRAP_SIGINFO; | |
2750 | } | |
2751 | ||
d6b0e80f AC |
2752 | /* Select one LWP out of those that have events pending. */ |
2753 | ||
2754 | static void | |
d90e17a7 | 2755 | select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
d6b0e80f AC |
2756 | { |
2757 | int num_events = 0; | |
2758 | int random_selector; | |
9c02b525 | 2759 | struct lwp_info *event_lp = NULL; |
d6b0e80f | 2760 | |
ac264b3b | 2761 | /* Record the wait status for the original LWP. */ |
d6b0e80f AC |
2762 | (*orig_lp)->status = *status; |
2763 | ||
9c02b525 PA |
2764 | /* In all-stop, give preference to the LWP that is being |
2765 | single-stepped. There will be at most one, and it will be the | |
2766 | LWP that the core is most interested in. If we didn't do this, | |
2767 | then we'd have to handle pending step SIGTRAPs somehow in case | |
2768 | the core later continues the previously-stepped thread, as | |
2769 | otherwise we'd report the pending SIGTRAP then, and the core, not | |
2770 | having stepped the thread, wouldn't understand what the trap was | |
2771 | for, and therefore would report it to the user as a random | |
2772 | signal. */ | |
fbea99ea | 2773 | if (!target_is_non_stop_p ()) |
d6b0e80f | 2774 | { |
d3a70e03 | 2775 | event_lp = iterate_over_lwps (filter, select_singlestep_lwp_callback); |
9c02b525 PA |
2776 | if (event_lp != NULL) |
2777 | { | |
9327494e SM |
2778 | linux_nat_debug_printf ("Select single-step %s", |
2779 | target_pid_to_str (event_lp->ptid).c_str ()); | |
9c02b525 | 2780 | } |
d6b0e80f | 2781 | } |
9c02b525 PA |
2782 | |
2783 | if (event_lp == NULL) | |
d6b0e80f | 2784 | { |
9c02b525 | 2785 | /* Pick one at random, out of those which have had events. */ |
d6b0e80f | 2786 | |
9c02b525 | 2787 | /* First see how many events we have. */ |
d3a70e03 TT |
2788 | iterate_over_lwps (filter, |
2789 | [&] (struct lwp_info *info) | |
2790 | { | |
2791 | return count_events_callback (info, &num_events); | |
2792 | }); | |
8bf3b159 | 2793 | gdb_assert (num_events > 0); |
d6b0e80f | 2794 | |
9c02b525 PA |
2795 | /* Now randomly pick a LWP out of those that have had |
2796 | events. */ | |
d6b0e80f AC |
2797 | random_selector = (int) |
2798 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
2799 | ||
9327494e SM |
2800 | if (num_events > 1) |
2801 | linux_nat_debug_printf ("Found %d events, selecting #%d", | |
2802 | num_events, random_selector); | |
d6b0e80f | 2803 | |
d3a70e03 TT |
2804 | event_lp |
2805 | = (iterate_over_lwps | |
2806 | (filter, | |
2807 | [&] (struct lwp_info *info) | |
2808 | { | |
2809 | return select_event_lwp_callback (info, | |
2810 | &random_selector); | |
2811 | })); | |
d6b0e80f AC |
2812 | } |
2813 | ||
2814 | if (event_lp != NULL) | |
2815 | { | |
2816 | /* Switch the event LWP. */ | |
2817 | *orig_lp = event_lp; | |
2818 | *status = event_lp->status; | |
2819 | } | |
2820 | ||
2821 | /* Flush the wait status for the event LWP. */ | |
2822 | (*orig_lp)->status = 0; | |
2823 | } | |
2824 | ||
2825 | /* Return non-zero if LP has been resumed. */ | |
2826 | ||
2827 | static int | |
d3a70e03 | 2828 | resumed_callback (struct lwp_info *lp) |
d6b0e80f AC |
2829 | { |
2830 | return lp->resumed; | |
2831 | } | |
2832 | ||
02f3fc28 | 2833 | /* Check if we should go on and pass this event to common code. |
7da6a5b9 | 2834 | Return the affected lwp if we should, or NULL otherwise. */ |
12d9289a | 2835 | |
02f3fc28 | 2836 | static struct lwp_info * |
9c02b525 | 2837 | linux_nat_filter_event (int lwpid, int status) |
02f3fc28 PA |
2838 | { |
2839 | struct lwp_info *lp; | |
89a5711c | 2840 | int event = linux_ptrace_get_extended_event (status); |
02f3fc28 | 2841 | |
f2907e49 | 2842 | lp = find_lwp_pid (ptid_t (lwpid)); |
02f3fc28 PA |
2843 | |
2844 | /* Check for stop events reported by a process we didn't already | |
2845 | know about - anything not already in our LWP list. | |
2846 | ||
2847 | If we're expecting to receive stopped processes after | |
2848 | fork, vfork, and clone events, then we'll just add the | |
2849 | new one to our list and go back to waiting for the event | |
2850 | to be reported - the stopped process might be returned | |
0e5bf2a8 PA |
2851 | from waitpid before or after the event is. |
2852 | ||
2853 | But note the case of a non-leader thread exec'ing after the | |
2854 | leader having exited, and gone from our lists. The non-leader | |
2855 | thread changes its tid to the tgid. */ | |
2856 | ||
2857 | if (WIFSTOPPED (status) && lp == NULL | |
89a5711c | 2858 | && (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC)) |
0e5bf2a8 PA |
2859 | { |
2860 | /* A multi-thread exec after we had seen the leader exiting. */ | |
9327494e | 2861 | linux_nat_debug_printf ("Re-adding thread group leader LWP %d.", lwpid); |
0e5bf2a8 | 2862 | |
fd79271b | 2863 | lp = add_lwp (ptid_t (lwpid, lwpid, 0)); |
0e5bf2a8 PA |
2864 | lp->stopped = 1; |
2865 | lp->resumed = 1; | |
5b6d1e4f | 2866 | add_thread (linux_target, lp->ptid); |
0e5bf2a8 PA |
2867 | } |
2868 | ||
02f3fc28 PA |
2869 | if (WIFSTOPPED (status) && !lp) |
2870 | { | |
9327494e SM |
2871 | linux_nat_debug_printf ("saving LWP %ld status %s in stopped_pids list", |
2872 | (long) lwpid, status_to_str (status)); | |
84636d28 | 2873 | add_to_pid_list (&stopped_pids, lwpid, status); |
02f3fc28 PA |
2874 | return NULL; |
2875 | } | |
2876 | ||
2877 | /* Make sure we don't report an event for the exit of an LWP not in | |
1777feb0 | 2878 | our list, i.e. not part of the current process. This can happen |
fd62cb89 | 2879 | if we detach from a program we originally forked and then it |
02f3fc28 PA |
2880 | exits. */ |
2881 | if (!WIFSTOPPED (status) && !lp) | |
2882 | return NULL; | |
2883 | ||
8817a6f2 PA |
2884 | /* This LWP is stopped now. (And if dead, this prevents it from |
2885 | ever being continued.) */ | |
2886 | lp->stopped = 1; | |
2887 | ||
8784d563 PA |
2888 | if (WIFSTOPPED (status) && lp->must_set_ptrace_flags) |
2889 | { | |
5b6d1e4f | 2890 | inferior *inf = find_inferior_pid (linux_target, lp->ptid.pid ()); |
de0d863e | 2891 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 2892 | |
e38504b3 | 2893 | linux_enable_event_reporting (lp->ptid.lwp (), options); |
8784d563 PA |
2894 | lp->must_set_ptrace_flags = 0; |
2895 | } | |
2896 | ||
ca2163eb PA |
2897 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2898 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2899 | { | |
2900 | /* No longer need the sysgood bit. The ptrace event ends up | |
2901 | recorded in lp->waitstatus if we care for it. We can carry | |
2902 | on handling the event like a regular SIGTRAP from here | |
2903 | on. */ | |
2904 | status = W_STOPCODE (SIGTRAP); | |
2905 | if (linux_handle_syscall_trap (lp, 0)) | |
2906 | return NULL; | |
2907 | } | |
bfd09d20 JS |
2908 | else |
2909 | { | |
2910 | /* Almost all other ptrace-stops are known to be outside of system | |
2911 | calls, with further exceptions in linux_handle_extended_wait. */ | |
2912 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2913 | } | |
02f3fc28 | 2914 | |
ca2163eb | 2915 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2916 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2917 | && linux_is_extended_waitstatus (status)) | |
02f3fc28 | 2918 | { |
9327494e SM |
2919 | linux_nat_debug_printf ("Handling extended status 0x%06x", status); |
2920 | ||
4dd63d48 | 2921 | if (linux_handle_extended_wait (lp, status)) |
02f3fc28 PA |
2922 | return NULL; |
2923 | } | |
2924 | ||
2925 | /* Check if the thread has exited. */ | |
9c02b525 PA |
2926 | if (WIFEXITED (status) || WIFSIGNALED (status)) |
2927 | { | |
aa01bd36 | 2928 | if (!report_thread_events |
e99b03dc | 2929 | && num_lwps (lp->ptid.pid ()) > 1) |
02f3fc28 | 2930 | { |
9327494e SM |
2931 | linux_nat_debug_printf ("%s exited.", |
2932 | target_pid_to_str (lp->ptid).c_str ()); | |
9c02b525 | 2933 | |
4a6ed09b PA |
2934 | /* If there is at least one more LWP, then the exit signal |
2935 | was not the end of the debugged application and should be | |
2936 | ignored. */ | |
2937 | exit_lwp (lp); | |
2938 | return NULL; | |
02f3fc28 PA |
2939 | } |
2940 | ||
77598427 PA |
2941 | /* Note that even if the leader was ptrace-stopped, it can still |
2942 | exit, if e.g., some other thread brings down the whole | |
2943 | process (calls `exit'). So don't assert that the lwp is | |
2944 | resumed. */ | |
9327494e SM |
2945 | linux_nat_debug_printf ("LWP %ld exited (resumed=%d)", |
2946 | lp->ptid.lwp (), lp->resumed); | |
02f3fc28 | 2947 | |
9c02b525 PA |
2948 | /* Dead LWP's aren't expected to reported a pending sigstop. */ |
2949 | lp->signalled = 0; | |
2950 | ||
2951 | /* Store the pending event in the waitstatus, because | |
2952 | W_EXITCODE(0,0) == 0. */ | |
2953 | store_waitstatus (&lp->waitstatus, status); | |
2954 | return lp; | |
02f3fc28 PA |
2955 | } |
2956 | ||
02f3fc28 PA |
2957 | /* Make sure we don't report a SIGSTOP that we sent ourselves in |
2958 | an attempt to stop an LWP. */ | |
2959 | if (lp->signalled | |
2960 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) | |
2961 | { | |
02f3fc28 PA |
2962 | lp->signalled = 0; |
2963 | ||
2bf6fb9d | 2964 | if (lp->last_resume_kind == resume_stop) |
25289eb2 | 2965 | { |
9327494e SM |
2966 | linux_nat_debug_printf ("resume_stop SIGSTOP caught for %s.", |
2967 | target_pid_to_str (lp->ptid).c_str ()); | |
2bf6fb9d PA |
2968 | } |
2969 | else | |
2970 | { | |
2971 | /* This is a delayed SIGSTOP. Filter out the event. */ | |
02f3fc28 | 2972 | |
9327494e SM |
2973 | linux_nat_debug_printf |
2974 | ("%s %s, 0, 0 (discard delayed SIGSTOP)", | |
2975 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
2976 | target_pid_to_str (lp->ptid).c_str ()); | |
02f3fc28 | 2977 | |
2bf6fb9d | 2978 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
25289eb2 | 2979 | gdb_assert (lp->resumed); |
25289eb2 PA |
2980 | return NULL; |
2981 | } | |
02f3fc28 PA |
2982 | } |
2983 | ||
57380f4e DJ |
2984 | /* Make sure we don't report a SIGINT that we have already displayed |
2985 | for another thread. */ | |
2986 | if (lp->ignore_sigint | |
2987 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) | |
2988 | { | |
9327494e SM |
2989 | linux_nat_debug_printf ("Delayed SIGINT caught for %s.", |
2990 | target_pid_to_str (lp->ptid).c_str ()); | |
57380f4e DJ |
2991 | |
2992 | /* This is a delayed SIGINT. */ | |
2993 | lp->ignore_sigint = 0; | |
2994 | ||
8a99810d | 2995 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
9327494e SM |
2996 | linux_nat_debug_printf ("%s %s, 0, 0 (discard SIGINT)", |
2997 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
2998 | target_pid_to_str (lp->ptid).c_str ()); | |
57380f4e DJ |
2999 | gdb_assert (lp->resumed); |
3000 | ||
3001 | /* Discard the event. */ | |
3002 | return NULL; | |
3003 | } | |
3004 | ||
9c02b525 PA |
3005 | /* Don't report signals that GDB isn't interested in, such as |
3006 | signals that are neither printed nor stopped upon. Stopping all | |
7da6a5b9 | 3007 | threads can be a bit time-consuming, so if we want decent |
9c02b525 PA |
3008 | performance with heavily multi-threaded programs, especially when |
3009 | they're using a high frequency timer, we'd better avoid it if we | |
3010 | can. */ | |
3011 | if (WIFSTOPPED (status)) | |
3012 | { | |
3013 | enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status)); | |
3014 | ||
fbea99ea | 3015 | if (!target_is_non_stop_p ()) |
9c02b525 PA |
3016 | { |
3017 | /* Only do the below in all-stop, as we currently use SIGSTOP | |
3018 | to implement target_stop (see linux_nat_stop) in | |
3019 | non-stop. */ | |
3020 | if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0) | |
3021 | { | |
3022 | /* If ^C/BREAK is typed at the tty/console, SIGINT gets | |
3023 | forwarded to the entire process group, that is, all LWPs | |
3024 | will receive it - unless they're using CLONE_THREAD to | |
3025 | share signals. Since we only want to report it once, we | |
3026 | mark it as ignored for all LWPs except this one. */ | |
d3a70e03 | 3027 | iterate_over_lwps (ptid_t (lp->ptid.pid ()), set_ignore_sigint); |
9c02b525 PA |
3028 | lp->ignore_sigint = 0; |
3029 | } | |
3030 | else | |
3031 | maybe_clear_ignore_sigint (lp); | |
3032 | } | |
3033 | ||
3034 | /* When using hardware single-step, we need to report every signal. | |
c9587f88 | 3035 | Otherwise, signals in pass_mask may be short-circuited |
d8c06f22 AB |
3036 | except signals that might be caused by a breakpoint, or SIGSTOP |
3037 | if we sent the SIGSTOP and are waiting for it to arrive. */ | |
9c02b525 | 3038 | if (!lp->step |
c9587f88 | 3039 | && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status)) |
d8c06f22 | 3040 | && (WSTOPSIG (status) != SIGSTOP |
5b6d1e4f | 3041 | || !find_thread_ptid (linux_target, lp->ptid)->stop_requested) |
c9587f88 | 3042 | && !linux_wstatus_maybe_breakpoint (status)) |
9c02b525 PA |
3043 | { |
3044 | linux_resume_one_lwp (lp, lp->step, signo); | |
9327494e SM |
3045 | linux_nat_debug_printf |
3046 | ("%s %s, %s (preempt 'handle')", | |
3047 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3048 | target_pid_to_str (lp->ptid).c_str (), | |
3049 | (signo != GDB_SIGNAL_0 | |
3050 | ? strsignal (gdb_signal_to_host (signo)) : "0")); | |
9c02b525 PA |
3051 | return NULL; |
3052 | } | |
3053 | } | |
3054 | ||
02f3fc28 PA |
3055 | /* An interesting event. */ |
3056 | gdb_assert (lp); | |
ca2163eb | 3057 | lp->status = status; |
e7ad2f14 | 3058 | save_stop_reason (lp); |
02f3fc28 PA |
3059 | return lp; |
3060 | } | |
3061 | ||
0e5bf2a8 PA |
3062 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
3063 | their exits until all other threads in the group have exited. */ | |
3064 | ||
3065 | static void | |
3066 | check_zombie_leaders (void) | |
3067 | { | |
08036331 | 3068 | for (inferior *inf : all_inferiors ()) |
0e5bf2a8 PA |
3069 | { |
3070 | struct lwp_info *leader_lp; | |
3071 | ||
3072 | if (inf->pid == 0) | |
3073 | continue; | |
3074 | ||
f2907e49 | 3075 | leader_lp = find_lwp_pid (ptid_t (inf->pid)); |
0e5bf2a8 PA |
3076 | if (leader_lp != NULL |
3077 | /* Check if there are other threads in the group, as we may | |
3078 | have raced with the inferior simply exiting. */ | |
3079 | && num_lwps (inf->pid) > 1 | |
5f572dec | 3080 | && linux_proc_pid_is_zombie (inf->pid)) |
0e5bf2a8 | 3081 | { |
9327494e SM |
3082 | linux_nat_debug_printf ("Thread group leader %d zombie " |
3083 | "(it exited, or another thread execd).", | |
3084 | inf->pid); | |
0e5bf2a8 PA |
3085 | |
3086 | /* A leader zombie can mean one of two things: | |
3087 | ||
3088 | - It exited, and there's an exit status pending | |
3089 | available, or only the leader exited (not the whole | |
3090 | program). In the latter case, we can't waitpid the | |
3091 | leader's exit status until all other threads are gone. | |
3092 | ||
3093 | - There are 3 or more threads in the group, and a thread | |
4a6ed09b PA |
3094 | other than the leader exec'd. See comments on exec |
3095 | events at the top of the file. We could try | |
0e5bf2a8 PA |
3096 | distinguishing the exit and exec cases, by waiting once |
3097 | more, and seeing if something comes out, but it doesn't | |
3098 | sound useful. The previous leader _does_ go away, and | |
3099 | we'll re-add the new one once we see the exec event | |
3100 | (which is just the same as what would happen if the | |
3101 | previous leader did exit voluntarily before some other | |
3102 | thread execs). */ | |
3103 | ||
9327494e | 3104 | linux_nat_debug_printf ("Thread group leader %d vanished.", inf->pid); |
0e5bf2a8 PA |
3105 | exit_lwp (leader_lp); |
3106 | } | |
3107 | } | |
3108 | } | |
3109 | ||
aa01bd36 PA |
3110 | /* Convenience function that is called when the kernel reports an exit |
3111 | event. This decides whether to report the event to GDB as a | |
3112 | process exit event, a thread exit event, or to suppress the | |
3113 | event. */ | |
3114 | ||
3115 | static ptid_t | |
3116 | filter_exit_event (struct lwp_info *event_child, | |
3117 | struct target_waitstatus *ourstatus) | |
3118 | { | |
3119 | ptid_t ptid = event_child->ptid; | |
3120 | ||
e99b03dc | 3121 | if (num_lwps (ptid.pid ()) > 1) |
aa01bd36 PA |
3122 | { |
3123 | if (report_thread_events) | |
3124 | ourstatus->kind = TARGET_WAITKIND_THREAD_EXITED; | |
3125 | else | |
3126 | ourstatus->kind = TARGET_WAITKIND_IGNORE; | |
3127 | ||
3128 | exit_lwp (event_child); | |
3129 | } | |
3130 | ||
3131 | return ptid; | |
3132 | } | |
3133 | ||
d6b0e80f | 3134 | static ptid_t |
f6ac5f3d | 3135 | linux_nat_wait_1 (ptid_t ptid, struct target_waitstatus *ourstatus, |
b60cea74 | 3136 | target_wait_flags target_options) |
d6b0e80f | 3137 | { |
fc9b8e47 | 3138 | sigset_t prev_mask; |
4b60df3d | 3139 | enum resume_kind last_resume_kind; |
12d9289a | 3140 | struct lwp_info *lp; |
12d9289a | 3141 | int status; |
d6b0e80f | 3142 | |
9327494e | 3143 | linux_nat_debug_printf ("enter"); |
b84876c2 | 3144 | |
f973ed9c DJ |
3145 | /* The first time we get here after starting a new inferior, we may |
3146 | not have added it to the LWP list yet - this is the earliest | |
3147 | moment at which we know its PID. */ | |
677c92fe | 3148 | if (ptid.is_pid () && find_lwp_pid (ptid) == nullptr) |
f973ed9c | 3149 | { |
677c92fe | 3150 | ptid_t lwp_ptid (ptid.pid (), ptid.pid ()); |
27c9d204 | 3151 | |
677c92fe SM |
3152 | /* Upgrade the main thread's ptid. */ |
3153 | thread_change_ptid (linux_target, ptid, lwp_ptid); | |
3154 | lp = add_initial_lwp (lwp_ptid); | |
f973ed9c DJ |
3155 | lp->resumed = 1; |
3156 | } | |
3157 | ||
12696c10 | 3158 | /* Make sure SIGCHLD is blocked until the sigsuspend below. */ |
7feb7d06 | 3159 | block_child_signals (&prev_mask); |
d6b0e80f | 3160 | |
d6b0e80f | 3161 | /* First check if there is a LWP with a wait status pending. */ |
d3a70e03 | 3162 | lp = iterate_over_lwps (ptid, status_callback); |
8a99810d | 3163 | if (lp != NULL) |
d6b0e80f | 3164 | { |
9327494e SM |
3165 | linux_nat_debug_printf ("Using pending wait status %s for %s.", |
3166 | status_to_str (lp->status), | |
3167 | target_pid_to_str (lp->ptid).c_str ()); | |
d6b0e80f AC |
3168 | } |
3169 | ||
9c02b525 PA |
3170 | /* But if we don't find a pending event, we'll have to wait. Always |
3171 | pull all events out of the kernel. We'll randomly select an | |
3172 | event LWP out of all that have events, to prevent starvation. */ | |
7feb7d06 | 3173 | |
d90e17a7 | 3174 | while (lp == NULL) |
d6b0e80f AC |
3175 | { |
3176 | pid_t lwpid; | |
3177 | ||
0e5bf2a8 PA |
3178 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
3179 | quirks: | |
3180 | ||
3181 | - If the thread group leader exits while other threads in the | |
3182 | thread group still exist, waitpid(TGID, ...) hangs. That | |
3183 | waitpid won't return an exit status until the other threads | |
85102364 | 3184 | in the group are reaped. |
0e5bf2a8 PA |
3185 | |
3186 | - When a non-leader thread execs, that thread just vanishes | |
3187 | without reporting an exit (so we'd hang if we waited for it | |
3188 | explicitly in that case). The exec event is reported to | |
3189 | the TGID pid. */ | |
3190 | ||
3191 | errno = 0; | |
4a6ed09b | 3192 | lwpid = my_waitpid (-1, &status, __WALL | WNOHANG); |
0e5bf2a8 | 3193 | |
9327494e SM |
3194 | linux_nat_debug_printf ("waitpid(-1, ...) returned %d, %s", |
3195 | lwpid, | |
3196 | errno ? safe_strerror (errno) : "ERRNO-OK"); | |
b84876c2 | 3197 | |
d6b0e80f AC |
3198 | if (lwpid > 0) |
3199 | { | |
9327494e | 3200 | linux_nat_debug_printf ("waitpid %ld received %s", |
d6b0e80f | 3201 | (long) lwpid, status_to_str (status)); |
d6b0e80f | 3202 | |
9c02b525 | 3203 | linux_nat_filter_event (lwpid, status); |
0e5bf2a8 PA |
3204 | /* Retry until nothing comes out of waitpid. A single |
3205 | SIGCHLD can indicate more than one child stopped. */ | |
3206 | continue; | |
d6b0e80f AC |
3207 | } |
3208 | ||
20ba1ce6 PA |
3209 | /* Now that we've pulled all events out of the kernel, resume |
3210 | LWPs that don't have an interesting event to report. */ | |
3211 | iterate_over_lwps (minus_one_ptid, | |
d3a70e03 TT |
3212 | [] (struct lwp_info *info) |
3213 | { | |
3214 | return resume_stopped_resumed_lwps (info, minus_one_ptid); | |
3215 | }); | |
20ba1ce6 PA |
3216 | |
3217 | /* ... and find an LWP with a status to report to the core, if | |
3218 | any. */ | |
d3a70e03 | 3219 | lp = iterate_over_lwps (ptid, status_callback); |
9c02b525 PA |
3220 | if (lp != NULL) |
3221 | break; | |
3222 | ||
0e5bf2a8 PA |
3223 | /* Check for zombie thread group leaders. Those can't be reaped |
3224 | until all other threads in the thread group are. */ | |
3225 | check_zombie_leaders (); | |
d6b0e80f | 3226 | |
0e5bf2a8 PA |
3227 | /* If there are no resumed children left, bail. We'd be stuck |
3228 | forever in the sigsuspend call below otherwise. */ | |
d3a70e03 | 3229 | if (iterate_over_lwps (ptid, resumed_callback) == NULL) |
0e5bf2a8 | 3230 | { |
9327494e | 3231 | linux_nat_debug_printf ("exit (no resumed LWP)"); |
b84876c2 | 3232 | |
0e5bf2a8 | 3233 | ourstatus->kind = TARGET_WAITKIND_NO_RESUMED; |
b84876c2 | 3234 | |
0e5bf2a8 PA |
3235 | restore_child_signals_mask (&prev_mask); |
3236 | return minus_one_ptid; | |
d6b0e80f | 3237 | } |
28736962 | 3238 | |
0e5bf2a8 PA |
3239 | /* No interesting event to report to the core. */ |
3240 | ||
3241 | if (target_options & TARGET_WNOHANG) | |
3242 | { | |
9327494e | 3243 | linux_nat_debug_printf ("exit (ignore)"); |
28736962 | 3244 | |
0e5bf2a8 | 3245 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
28736962 PA |
3246 | restore_child_signals_mask (&prev_mask); |
3247 | return minus_one_ptid; | |
3248 | } | |
d6b0e80f AC |
3249 | |
3250 | /* We shouldn't end up here unless we want to try again. */ | |
d90e17a7 | 3251 | gdb_assert (lp == NULL); |
0e5bf2a8 PA |
3252 | |
3253 | /* Block until we get an event reported with SIGCHLD. */ | |
9c3a5d93 | 3254 | wait_for_signal (); |
d6b0e80f AC |
3255 | } |
3256 | ||
d6b0e80f AC |
3257 | gdb_assert (lp); |
3258 | ||
ca2163eb PA |
3259 | status = lp->status; |
3260 | lp->status = 0; | |
3261 | ||
fbea99ea | 3262 | if (!target_is_non_stop_p ()) |
4c28f408 PA |
3263 | { |
3264 | /* Now stop all other LWP's ... */ | |
d3a70e03 | 3265 | iterate_over_lwps (minus_one_ptid, stop_callback); |
4c28f408 PA |
3266 | |
3267 | /* ... and wait until all of them have reported back that | |
3268 | they're no longer running. */ | |
d3a70e03 | 3269 | iterate_over_lwps (minus_one_ptid, stop_wait_callback); |
9c02b525 PA |
3270 | } |
3271 | ||
3272 | /* If we're not waiting for a specific LWP, choose an event LWP from | |
3273 | among those that have had events. Giving equal priority to all | |
3274 | LWPs that have had events helps prevent starvation. */ | |
d7e15655 | 3275 | if (ptid == minus_one_ptid || ptid.is_pid ()) |
9c02b525 PA |
3276 | select_event_lwp (ptid, &lp, &status); |
3277 | ||
3278 | gdb_assert (lp != NULL); | |
3279 | ||
3280 | /* Now that we've selected our final event LWP, un-adjust its PC if | |
faf09f01 PA |
3281 | it was a software breakpoint, and we can't reliably support the |
3282 | "stopped by software breakpoint" stop reason. */ | |
3283 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT | |
3284 | && !USE_SIGTRAP_SIGINFO) | |
9c02b525 | 3285 | { |
5b6d1e4f | 3286 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 3287 | struct gdbarch *gdbarch = regcache->arch (); |
527a273a | 3288 | int decr_pc = gdbarch_decr_pc_after_break (gdbarch); |
4c28f408 | 3289 | |
9c02b525 PA |
3290 | if (decr_pc != 0) |
3291 | { | |
3292 | CORE_ADDR pc; | |
d6b0e80f | 3293 | |
9c02b525 PA |
3294 | pc = regcache_read_pc (regcache); |
3295 | regcache_write_pc (regcache, pc + decr_pc); | |
3296 | } | |
3297 | } | |
e3e9f5a2 | 3298 | |
9c02b525 PA |
3299 | /* We'll need this to determine whether to report a SIGSTOP as |
3300 | GDB_SIGNAL_0. Need to take a copy because resume_clear_callback | |
3301 | clears it. */ | |
3302 | last_resume_kind = lp->last_resume_kind; | |
4b60df3d | 3303 | |
fbea99ea | 3304 | if (!target_is_non_stop_p ()) |
9c02b525 | 3305 | { |
e3e9f5a2 PA |
3306 | /* In all-stop, from the core's perspective, all LWPs are now |
3307 | stopped until a new resume action is sent over. */ | |
d3a70e03 | 3308 | iterate_over_lwps (minus_one_ptid, resume_clear_callback); |
e3e9f5a2 PA |
3309 | } |
3310 | else | |
25289eb2 | 3311 | { |
d3a70e03 | 3312 | resume_clear_callback (lp); |
25289eb2 | 3313 | } |
d6b0e80f | 3314 | |
135340af | 3315 | if (linux_target->low_status_is_event (status)) |
d6b0e80f | 3316 | { |
9327494e SM |
3317 | linux_nat_debug_printf ("trap ptid is %s.", |
3318 | target_pid_to_str (lp->ptid).c_str ()); | |
d6b0e80f | 3319 | } |
d6b0e80f AC |
3320 | |
3321 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
3322 | { | |
3323 | *ourstatus = lp->waitstatus; | |
3324 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
3325 | } | |
3326 | else | |
3327 | store_waitstatus (ourstatus, status); | |
3328 | ||
9327494e | 3329 | linux_nat_debug_printf ("exit"); |
b84876c2 | 3330 | |
7feb7d06 | 3331 | restore_child_signals_mask (&prev_mask); |
1e225492 | 3332 | |
4b60df3d | 3333 | if (last_resume_kind == resume_stop |
25289eb2 PA |
3334 | && ourstatus->kind == TARGET_WAITKIND_STOPPED |
3335 | && WSTOPSIG (status) == SIGSTOP) | |
3336 | { | |
3337 | /* A thread that has been requested to stop by GDB with | |
3338 | target_stop, and it stopped cleanly, so report as SIG0. The | |
3339 | use of SIGSTOP is an implementation detail. */ | |
a493e3e2 | 3340 | ourstatus->value.sig = GDB_SIGNAL_0; |
25289eb2 PA |
3341 | } |
3342 | ||
1e225492 JK |
3343 | if (ourstatus->kind == TARGET_WAITKIND_EXITED |
3344 | || ourstatus->kind == TARGET_WAITKIND_SIGNALLED) | |
3345 | lp->core = -1; | |
3346 | else | |
2e794194 | 3347 | lp->core = linux_common_core_of_thread (lp->ptid); |
1e225492 | 3348 | |
aa01bd36 PA |
3349 | if (ourstatus->kind == TARGET_WAITKIND_EXITED) |
3350 | return filter_exit_event (lp, ourstatus); | |
3351 | ||
f973ed9c | 3352 | return lp->ptid; |
d6b0e80f AC |
3353 | } |
3354 | ||
e3e9f5a2 PA |
3355 | /* Resume LWPs that are currently stopped without any pending status |
3356 | to report, but are resumed from the core's perspective. */ | |
3357 | ||
3358 | static int | |
d3a70e03 | 3359 | resume_stopped_resumed_lwps (struct lwp_info *lp, const ptid_t wait_ptid) |
e3e9f5a2 | 3360 | { |
4dd63d48 PA |
3361 | if (!lp->stopped) |
3362 | { | |
9327494e SM |
3363 | linux_nat_debug_printf ("NOT resuming LWP %s, not stopped", |
3364 | target_pid_to_str (lp->ptid).c_str ()); | |
4dd63d48 PA |
3365 | } |
3366 | else if (!lp->resumed) | |
3367 | { | |
9327494e SM |
3368 | linux_nat_debug_printf ("NOT resuming LWP %s, not resumed", |
3369 | target_pid_to_str (lp->ptid).c_str ()); | |
4dd63d48 PA |
3370 | } |
3371 | else if (lwp_status_pending_p (lp)) | |
3372 | { | |
9327494e SM |
3373 | linux_nat_debug_printf ("NOT resuming LWP %s, has pending status", |
3374 | target_pid_to_str (lp->ptid).c_str ()); | |
4dd63d48 PA |
3375 | } |
3376 | else | |
e3e9f5a2 | 3377 | { |
5b6d1e4f | 3378 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 3379 | struct gdbarch *gdbarch = regcache->arch (); |
336060f3 | 3380 | |
a70b8144 | 3381 | try |
e3e9f5a2 | 3382 | { |
23f238d3 PA |
3383 | CORE_ADDR pc = regcache_read_pc (regcache); |
3384 | int leave_stopped = 0; | |
e3e9f5a2 | 3385 | |
23f238d3 PA |
3386 | /* Don't bother if there's a breakpoint at PC that we'd hit |
3387 | immediately, and we're not waiting for this LWP. */ | |
d3a70e03 | 3388 | if (!lp->ptid.matches (wait_ptid)) |
23f238d3 | 3389 | { |
a01bda52 | 3390 | if (breakpoint_inserted_here_p (regcache->aspace (), pc)) |
23f238d3 PA |
3391 | leave_stopped = 1; |
3392 | } | |
e3e9f5a2 | 3393 | |
23f238d3 PA |
3394 | if (!leave_stopped) |
3395 | { | |
9327494e SM |
3396 | linux_nat_debug_printf |
3397 | ("resuming stopped-resumed LWP %s at %s: step=%d", | |
3398 | target_pid_to_str (lp->ptid).c_str (), paddress (gdbarch, pc), | |
3399 | lp->step); | |
23f238d3 PA |
3400 | |
3401 | linux_resume_one_lwp_throw (lp, lp->step, GDB_SIGNAL_0); | |
3402 | } | |
3403 | } | |
230d2906 | 3404 | catch (const gdb_exception_error &ex) |
23f238d3 PA |
3405 | { |
3406 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 3407 | throw; |
23f238d3 | 3408 | } |
e3e9f5a2 PA |
3409 | } |
3410 | ||
3411 | return 0; | |
3412 | } | |
3413 | ||
f6ac5f3d PA |
3414 | ptid_t |
3415 | linux_nat_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus, | |
b60cea74 | 3416 | target_wait_flags target_options) |
7feb7d06 PA |
3417 | { |
3418 | ptid_t event_ptid; | |
3419 | ||
9327494e SM |
3420 | linux_nat_debug_printf ("[%s], [%s]", target_pid_to_str (ptid).c_str (), |
3421 | target_options_to_string (target_options).c_str ()); | |
7feb7d06 PA |
3422 | |
3423 | /* Flush the async file first. */ | |
d9d41e78 | 3424 | if (target_is_async_p ()) |
7feb7d06 PA |
3425 | async_file_flush (); |
3426 | ||
e3e9f5a2 PA |
3427 | /* Resume LWPs that are currently stopped without any pending status |
3428 | to report, but are resumed from the core's perspective. LWPs get | |
3429 | in this state if we find them stopping at a time we're not | |
3430 | interested in reporting the event (target_wait on a | |
3431 | specific_process, for example, see linux_nat_wait_1), and | |
3432 | meanwhile the event became uninteresting. Don't bother resuming | |
3433 | LWPs we're not going to wait for if they'd stop immediately. */ | |
fbea99ea | 3434 | if (target_is_non_stop_p ()) |
d3a70e03 TT |
3435 | iterate_over_lwps (minus_one_ptid, |
3436 | [=] (struct lwp_info *info) | |
3437 | { | |
3438 | return resume_stopped_resumed_lwps (info, ptid); | |
3439 | }); | |
e3e9f5a2 | 3440 | |
f6ac5f3d | 3441 | event_ptid = linux_nat_wait_1 (ptid, ourstatus, target_options); |
7feb7d06 PA |
3442 | |
3443 | /* If we requested any event, and something came out, assume there | |
3444 | may be more. If we requested a specific lwp or process, also | |
3445 | assume there may be more. */ | |
d9d41e78 | 3446 | if (target_is_async_p () |
6953d224 PA |
3447 | && ((ourstatus->kind != TARGET_WAITKIND_IGNORE |
3448 | && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED) | |
d7e15655 | 3449 | || ptid != minus_one_ptid)) |
7feb7d06 PA |
3450 | async_file_mark (); |
3451 | ||
7feb7d06 PA |
3452 | return event_ptid; |
3453 | } | |
3454 | ||
1d2736d4 PA |
3455 | /* Kill one LWP. */ |
3456 | ||
3457 | static void | |
3458 | kill_one_lwp (pid_t pid) | |
d6b0e80f | 3459 | { |
ed731959 JK |
3460 | /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
3461 | ||
3462 | errno = 0; | |
1d2736d4 | 3463 | kill_lwp (pid, SIGKILL); |
9327494e | 3464 | |
ed731959 | 3465 | if (debug_linux_nat) |
57745c90 PA |
3466 | { |
3467 | int save_errno = errno; | |
3468 | ||
9327494e SM |
3469 | linux_nat_debug_printf |
3470 | ("kill (SIGKILL) %ld, 0, 0 (%s)", (long) pid, | |
3471 | save_errno != 0 ? safe_strerror (save_errno) : "OK"); | |
57745c90 | 3472 | } |
ed731959 JK |
3473 | |
3474 | /* Some kernels ignore even SIGKILL for processes under ptrace. */ | |
3475 | ||
d6b0e80f | 3476 | errno = 0; |
1d2736d4 | 3477 | ptrace (PTRACE_KILL, pid, 0, 0); |
d6b0e80f | 3478 | if (debug_linux_nat) |
57745c90 PA |
3479 | { |
3480 | int save_errno = errno; | |
3481 | ||
9327494e SM |
3482 | linux_nat_debug_printf |
3483 | ("PTRACE_KILL %ld, 0, 0 (%s)", (long) pid, | |
3484 | save_errno ? safe_strerror (save_errno) : "OK"); | |
57745c90 | 3485 | } |
d6b0e80f AC |
3486 | } |
3487 | ||
1d2736d4 PA |
3488 | /* Wait for an LWP to die. */ |
3489 | ||
3490 | static void | |
3491 | kill_wait_one_lwp (pid_t pid) | |
d6b0e80f | 3492 | { |
1d2736d4 | 3493 | pid_t res; |
d6b0e80f AC |
3494 | |
3495 | /* We must make sure that there are no pending events (delayed | |
3496 | SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current | |
3497 | program doesn't interfere with any following debugging session. */ | |
3498 | ||
d6b0e80f AC |
3499 | do |
3500 | { | |
1d2736d4 PA |
3501 | res = my_waitpid (pid, NULL, __WALL); |
3502 | if (res != (pid_t) -1) | |
d6b0e80f | 3503 | { |
9327494e SM |
3504 | linux_nat_debug_printf ("wait %ld received unknown.", (long) pid); |
3505 | ||
4a6ed09b PA |
3506 | /* The Linux kernel sometimes fails to kill a thread |
3507 | completely after PTRACE_KILL; that goes from the stop | |
3508 | point in do_fork out to the one in get_signal_to_deliver | |
3509 | and waits again. So kill it again. */ | |
1d2736d4 | 3510 | kill_one_lwp (pid); |
d6b0e80f AC |
3511 | } |
3512 | } | |
1d2736d4 PA |
3513 | while (res == pid); |
3514 | ||
3515 | gdb_assert (res == -1 && errno == ECHILD); | |
3516 | } | |
3517 | ||
3518 | /* Callback for iterate_over_lwps. */ | |
d6b0e80f | 3519 | |
1d2736d4 | 3520 | static int |
d3a70e03 | 3521 | kill_callback (struct lwp_info *lp) |
1d2736d4 | 3522 | { |
e38504b3 | 3523 | kill_one_lwp (lp->ptid.lwp ()); |
d6b0e80f AC |
3524 | return 0; |
3525 | } | |
3526 | ||
1d2736d4 PA |
3527 | /* Callback for iterate_over_lwps. */ |
3528 | ||
3529 | static int | |
d3a70e03 | 3530 | kill_wait_callback (struct lwp_info *lp) |
1d2736d4 | 3531 | { |
e38504b3 | 3532 | kill_wait_one_lwp (lp->ptid.lwp ()); |
1d2736d4 PA |
3533 | return 0; |
3534 | } | |
3535 | ||
3536 | /* Kill the fork children of any threads of inferior INF that are | |
3537 | stopped at a fork event. */ | |
3538 | ||
3539 | static void | |
3540 | kill_unfollowed_fork_children (struct inferior *inf) | |
3541 | { | |
08036331 PA |
3542 | for (thread_info *thread : inf->non_exited_threads ()) |
3543 | { | |
3544 | struct target_waitstatus *ws = &thread->pending_follow; | |
1d2736d4 | 3545 | |
08036331 PA |
3546 | if (ws->kind == TARGET_WAITKIND_FORKED |
3547 | || ws->kind == TARGET_WAITKIND_VFORKED) | |
3548 | { | |
3549 | ptid_t child_ptid = ws->value.related_pid; | |
3550 | int child_pid = child_ptid.pid (); | |
3551 | int child_lwp = child_ptid.lwp (); | |
3552 | ||
3553 | kill_one_lwp (child_lwp); | |
3554 | kill_wait_one_lwp (child_lwp); | |
3555 | ||
3556 | /* Let the arch-specific native code know this process is | |
3557 | gone. */ | |
3558 | linux_target->low_forget_process (child_pid); | |
3559 | } | |
3560 | } | |
1d2736d4 PA |
3561 | } |
3562 | ||
f6ac5f3d PA |
3563 | void |
3564 | linux_nat_target::kill () | |
d6b0e80f | 3565 | { |
f973ed9c DJ |
3566 | /* If we're stopped while forking and we haven't followed yet, |
3567 | kill the other task. We need to do this first because the | |
3568 | parent will be sleeping if this is a vfork. */ | |
1d2736d4 | 3569 | kill_unfollowed_fork_children (current_inferior ()); |
f973ed9c DJ |
3570 | |
3571 | if (forks_exist_p ()) | |
7feb7d06 | 3572 | linux_fork_killall (); |
f973ed9c DJ |
3573 | else |
3574 | { | |
e99b03dc | 3575 | ptid_t ptid = ptid_t (inferior_ptid.pid ()); |
e0881a8e | 3576 | |
4c28f408 | 3577 | /* Stop all threads before killing them, since ptrace requires |
30baf67b | 3578 | that the thread is stopped to successfully PTRACE_KILL. */ |
d3a70e03 | 3579 | iterate_over_lwps (ptid, stop_callback); |
4c28f408 PA |
3580 | /* ... and wait until all of them have reported back that |
3581 | they're no longer running. */ | |
d3a70e03 | 3582 | iterate_over_lwps (ptid, stop_wait_callback); |
4c28f408 | 3583 | |
f973ed9c | 3584 | /* Kill all LWP's ... */ |
d3a70e03 | 3585 | iterate_over_lwps (ptid, kill_callback); |
f973ed9c DJ |
3586 | |
3587 | /* ... and wait until we've flushed all events. */ | |
d3a70e03 | 3588 | iterate_over_lwps (ptid, kill_wait_callback); |
f973ed9c DJ |
3589 | } |
3590 | ||
bc1e6c81 | 3591 | target_mourn_inferior (inferior_ptid); |
d6b0e80f AC |
3592 | } |
3593 | ||
f6ac5f3d PA |
3594 | void |
3595 | linux_nat_target::mourn_inferior () | |
d6b0e80f | 3596 | { |
e99b03dc | 3597 | int pid = inferior_ptid.pid (); |
26cb8b7c PA |
3598 | |
3599 | purge_lwp_list (pid); | |
d6b0e80f | 3600 | |
f973ed9c | 3601 | if (! forks_exist_p ()) |
d90e17a7 | 3602 | /* Normal case, no other forks available. */ |
f6ac5f3d | 3603 | inf_ptrace_target::mourn_inferior (); |
f973ed9c DJ |
3604 | else |
3605 | /* Multi-fork case. The current inferior_ptid has exited, but | |
3606 | there are other viable forks to debug. Delete the exiting | |
3607 | one and context-switch to the first available. */ | |
3608 | linux_fork_mourn_inferior (); | |
26cb8b7c PA |
3609 | |
3610 | /* Let the arch-specific native code know this process is gone. */ | |
135340af | 3611 | linux_target->low_forget_process (pid); |
d6b0e80f AC |
3612 | } |
3613 | ||
5b009018 PA |
3614 | /* Convert a native/host siginfo object, into/from the siginfo in the |
3615 | layout of the inferiors' architecture. */ | |
3616 | ||
3617 | static void | |
a5362b9a | 3618 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
5b009018 | 3619 | { |
135340af PA |
3620 | /* If the low target didn't do anything, then just do a straight |
3621 | memcpy. */ | |
3622 | if (!linux_target->low_siginfo_fixup (siginfo, inf_siginfo, direction)) | |
5b009018 PA |
3623 | { |
3624 | if (direction == 1) | |
a5362b9a | 3625 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
5b009018 | 3626 | else |
a5362b9a | 3627 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
5b009018 PA |
3628 | } |
3629 | } | |
3630 | ||
9b409511 | 3631 | static enum target_xfer_status |
f6ac5f3d | 3632 | linux_xfer_siginfo (enum target_object object, |
4aa995e1 | 3633 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
3634 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
3635 | ULONGEST *xfered_len) | |
4aa995e1 | 3636 | { |
4aa995e1 | 3637 | int pid; |
a5362b9a TS |
3638 | siginfo_t siginfo; |
3639 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; | |
4aa995e1 PA |
3640 | |
3641 | gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO); | |
3642 | gdb_assert (readbuf || writebuf); | |
3643 | ||
e38504b3 | 3644 | pid = inferior_ptid.lwp (); |
4aa995e1 | 3645 | if (pid == 0) |
e99b03dc | 3646 | pid = inferior_ptid.pid (); |
4aa995e1 PA |
3647 | |
3648 | if (offset > sizeof (siginfo)) | |
2ed4b548 | 3649 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3650 | |
3651 | errno = 0; | |
3652 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3653 | if (errno != 0) | |
2ed4b548 | 3654 | return TARGET_XFER_E_IO; |
4aa995e1 | 3655 | |
5b009018 PA |
3656 | /* When GDB is built as a 64-bit application, ptrace writes into |
3657 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
3658 | inferior with a 64-bit GDB should look the same as debugging it | |
3659 | with a 32-bit GDB, we need to convert it. GDB core always sees | |
3660 | the converted layout, so any read/write will have to be done | |
3661 | post-conversion. */ | |
3662 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
3663 | ||
4aa995e1 PA |
3664 | if (offset + len > sizeof (siginfo)) |
3665 | len = sizeof (siginfo) - offset; | |
3666 | ||
3667 | if (readbuf != NULL) | |
5b009018 | 3668 | memcpy (readbuf, inf_siginfo + offset, len); |
4aa995e1 PA |
3669 | else |
3670 | { | |
5b009018 PA |
3671 | memcpy (inf_siginfo + offset, writebuf, len); |
3672 | ||
3673 | /* Convert back to ptrace layout before flushing it out. */ | |
3674 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
3675 | ||
4aa995e1 PA |
3676 | errno = 0; |
3677 | ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3678 | if (errno != 0) | |
2ed4b548 | 3679 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3680 | } |
3681 | ||
9b409511 YQ |
3682 | *xfered_len = len; |
3683 | return TARGET_XFER_OK; | |
4aa995e1 PA |
3684 | } |
3685 | ||
9b409511 | 3686 | static enum target_xfer_status |
f6ac5f3d PA |
3687 | linux_nat_xfer_osdata (enum target_object object, |
3688 | const char *annex, gdb_byte *readbuf, | |
3689 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, | |
3690 | ULONGEST *xfered_len); | |
3691 | ||
f6ac5f3d PA |
3692 | static enum target_xfer_status |
3693 | linux_proc_xfer_partial (enum target_object object, | |
3694 | const char *annex, gdb_byte *readbuf, | |
3695 | const gdb_byte *writebuf, | |
3696 | ULONGEST offset, LONGEST len, ULONGEST *xfered_len); | |
3697 | ||
3698 | enum target_xfer_status | |
3699 | linux_nat_target::xfer_partial (enum target_object object, | |
3700 | const char *annex, gdb_byte *readbuf, | |
3701 | const gdb_byte *writebuf, | |
3702 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) | |
d6b0e80f | 3703 | { |
9b409511 | 3704 | enum target_xfer_status xfer; |
d6b0e80f | 3705 | |
4aa995e1 | 3706 | if (object == TARGET_OBJECT_SIGNAL_INFO) |
f6ac5f3d | 3707 | return linux_xfer_siginfo (object, annex, readbuf, writebuf, |
9b409511 | 3708 | offset, len, xfered_len); |
4aa995e1 | 3709 | |
c35b1492 PA |
3710 | /* The target is connected but no live inferior is selected. Pass |
3711 | this request down to a lower stratum (e.g., the executable | |
3712 | file). */ | |
d7e15655 | 3713 | if (object == TARGET_OBJECT_MEMORY && inferior_ptid == null_ptid) |
9b409511 | 3714 | return TARGET_XFER_EOF; |
c35b1492 | 3715 | |
f6ac5f3d PA |
3716 | if (object == TARGET_OBJECT_AUXV) |
3717 | return memory_xfer_auxv (this, object, annex, readbuf, writebuf, | |
3718 | offset, len, xfered_len); | |
3719 | ||
3720 | if (object == TARGET_OBJECT_OSDATA) | |
3721 | return linux_nat_xfer_osdata (object, annex, readbuf, writebuf, | |
3722 | offset, len, xfered_len); | |
d6b0e80f | 3723 | |
f6ac5f3d PA |
3724 | /* GDB calculates all addresses in the largest possible address |
3725 | width. | |
3726 | The address width must be masked before its final use - either by | |
3727 | linux_proc_xfer_partial or inf_ptrace_target::xfer_partial. | |
3728 | ||
3729 | Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ | |
3730 | ||
3731 | if (object == TARGET_OBJECT_MEMORY) | |
3732 | { | |
3733 | int addr_bit = gdbarch_addr_bit (target_gdbarch ()); | |
3734 | ||
3735 | if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) | |
3736 | offset &= ((ULONGEST) 1 << addr_bit) - 1; | |
3737 | } | |
3738 | ||
3739 | xfer = linux_proc_xfer_partial (object, annex, readbuf, writebuf, | |
3740 | offset, len, xfered_len); | |
3741 | if (xfer != TARGET_XFER_EOF) | |
3742 | return xfer; | |
3743 | ||
3744 | return inf_ptrace_target::xfer_partial (object, annex, readbuf, writebuf, | |
3745 | offset, len, xfered_len); | |
d6b0e80f AC |
3746 | } |
3747 | ||
57810aa7 | 3748 | bool |
f6ac5f3d | 3749 | linux_nat_target::thread_alive (ptid_t ptid) |
28439f5e | 3750 | { |
4a6ed09b PA |
3751 | /* As long as a PTID is in lwp list, consider it alive. */ |
3752 | return find_lwp_pid (ptid) != NULL; | |
28439f5e PA |
3753 | } |
3754 | ||
8a06aea7 PA |
3755 | /* Implement the to_update_thread_list target method for this |
3756 | target. */ | |
3757 | ||
f6ac5f3d PA |
3758 | void |
3759 | linux_nat_target::update_thread_list () | |
8a06aea7 | 3760 | { |
a6904d5a PA |
3761 | struct lwp_info *lwp; |
3762 | ||
4a6ed09b PA |
3763 | /* We add/delete threads from the list as clone/exit events are |
3764 | processed, so just try deleting exited threads still in the | |
3765 | thread list. */ | |
3766 | delete_exited_threads (); | |
a6904d5a PA |
3767 | |
3768 | /* Update the processor core that each lwp/thread was last seen | |
3769 | running on. */ | |
3770 | ALL_LWPS (lwp) | |
1ad3de98 PA |
3771 | { |
3772 | /* Avoid accessing /proc if the thread hasn't run since we last | |
3773 | time we fetched the thread's core. Accessing /proc becomes | |
3774 | noticeably expensive when we have thousands of LWPs. */ | |
3775 | if (lwp->core == -1) | |
3776 | lwp->core = linux_common_core_of_thread (lwp->ptid); | |
3777 | } | |
8a06aea7 PA |
3778 | } |
3779 | ||
a068643d | 3780 | std::string |
f6ac5f3d | 3781 | linux_nat_target::pid_to_str (ptid_t ptid) |
d6b0e80f | 3782 | { |
15a9e13e | 3783 | if (ptid.lwp_p () |
e38504b3 | 3784 | && (ptid.pid () != ptid.lwp () |
e99b03dc | 3785 | || num_lwps (ptid.pid ()) > 1)) |
a068643d | 3786 | return string_printf ("LWP %ld", ptid.lwp ()); |
d6b0e80f AC |
3787 | |
3788 | return normal_pid_to_str (ptid); | |
3789 | } | |
3790 | ||
f6ac5f3d PA |
3791 | const char * |
3792 | linux_nat_target::thread_name (struct thread_info *thr) | |
4694da01 | 3793 | { |
79efa585 | 3794 | return linux_proc_tid_get_name (thr->ptid); |
4694da01 TT |
3795 | } |
3796 | ||
dba24537 AC |
3797 | /* Accepts an integer PID; Returns a string representing a file that |
3798 | can be opened to get the symbols for the child process. */ | |
3799 | ||
f6ac5f3d PA |
3800 | char * |
3801 | linux_nat_target::pid_to_exec_file (int pid) | |
dba24537 | 3802 | { |
e0d86d2c | 3803 | return linux_proc_pid_to_exec_file (pid); |
dba24537 AC |
3804 | } |
3805 | ||
a379284a AA |
3806 | /* Implement the to_xfer_partial target method using /proc/<pid>/mem. |
3807 | Because we can use a single read/write call, this can be much more | |
3808 | efficient than banging away at PTRACE_PEEKTEXT. */ | |
10d6c8cd | 3809 | |
9b409511 | 3810 | static enum target_xfer_status |
f6ac5f3d | 3811 | linux_proc_xfer_partial (enum target_object object, |
10d6c8cd DJ |
3812 | const char *annex, gdb_byte *readbuf, |
3813 | const gdb_byte *writebuf, | |
9b409511 | 3814 | ULONGEST offset, LONGEST len, ULONGEST *xfered_len) |
dba24537 | 3815 | { |
10d6c8cd DJ |
3816 | LONGEST ret; |
3817 | int fd; | |
dba24537 AC |
3818 | char filename[64]; |
3819 | ||
a379284a | 3820 | if (object != TARGET_OBJECT_MEMORY) |
f486487f | 3821 | return TARGET_XFER_EOF; |
dba24537 AC |
3822 | |
3823 | /* Don't bother for one word. */ | |
3824 | if (len < 3 * sizeof (long)) | |
9b409511 | 3825 | return TARGET_XFER_EOF; |
dba24537 AC |
3826 | |
3827 | /* We could keep this file open and cache it - possibly one per | |
3828 | thread. That requires some juggling, but is even faster. */ | |
b67aeab0 | 3829 | xsnprintf (filename, sizeof filename, "/proc/%ld/mem", |
e38504b3 | 3830 | inferior_ptid.lwp ()); |
a379284a AA |
3831 | fd = gdb_open_cloexec (filename, ((readbuf ? O_RDONLY : O_WRONLY) |
3832 | | O_LARGEFILE), 0); | |
dba24537 | 3833 | if (fd == -1) |
9b409511 | 3834 | return TARGET_XFER_EOF; |
dba24537 | 3835 | |
a379284a AA |
3836 | /* Use pread64/pwrite64 if available, since they save a syscall and can |
3837 | handle 64-bit offsets even on 32-bit platforms (for instance, SPARC | |
3838 | debugging a SPARC64 application). */ | |
dba24537 | 3839 | #ifdef HAVE_PREAD64 |
a379284a AA |
3840 | ret = (readbuf ? pread64 (fd, readbuf, len, offset) |
3841 | : pwrite64 (fd, writebuf, len, offset)); | |
dba24537 | 3842 | #else |
a379284a AA |
3843 | ret = lseek (fd, offset, SEEK_SET); |
3844 | if (ret != -1) | |
3845 | ret = (readbuf ? read (fd, readbuf, len) | |
3846 | : write (fd, writebuf, len)); | |
dba24537 | 3847 | #endif |
dba24537 AC |
3848 | |
3849 | close (fd); | |
9b409511 | 3850 | |
a379284a | 3851 | if (ret == -1 || ret == 0) |
9b409511 YQ |
3852 | return TARGET_XFER_EOF; |
3853 | else | |
3854 | { | |
3855 | *xfered_len = ret; | |
3856 | return TARGET_XFER_OK; | |
3857 | } | |
dba24537 AC |
3858 | } |
3859 | ||
efcbbd14 | 3860 | |
dba24537 AC |
3861 | /* Parse LINE as a signal set and add its set bits to SIGS. */ |
3862 | ||
3863 | static void | |
3864 | add_line_to_sigset (const char *line, sigset_t *sigs) | |
3865 | { | |
3866 | int len = strlen (line) - 1; | |
3867 | const char *p; | |
3868 | int signum; | |
3869 | ||
3870 | if (line[len] != '\n') | |
8a3fe4f8 | 3871 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
3872 | |
3873 | p = line; | |
3874 | signum = len * 4; | |
3875 | while (len-- > 0) | |
3876 | { | |
3877 | int digit; | |
3878 | ||
3879 | if (*p >= '0' && *p <= '9') | |
3880 | digit = *p - '0'; | |
3881 | else if (*p >= 'a' && *p <= 'f') | |
3882 | digit = *p - 'a' + 10; | |
3883 | else | |
8a3fe4f8 | 3884 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
3885 | |
3886 | signum -= 4; | |
3887 | ||
3888 | if (digit & 1) | |
3889 | sigaddset (sigs, signum + 1); | |
3890 | if (digit & 2) | |
3891 | sigaddset (sigs, signum + 2); | |
3892 | if (digit & 4) | |
3893 | sigaddset (sigs, signum + 3); | |
3894 | if (digit & 8) | |
3895 | sigaddset (sigs, signum + 4); | |
3896 | ||
3897 | p++; | |
3898 | } | |
3899 | } | |
3900 | ||
3901 | /* Find process PID's pending signals from /proc/pid/status and set | |
3902 | SIGS to match. */ | |
3903 | ||
3904 | void | |
3e43a32a MS |
3905 | linux_proc_pending_signals (int pid, sigset_t *pending, |
3906 | sigset_t *blocked, sigset_t *ignored) | |
dba24537 | 3907 | { |
d8d2a3ee | 3908 | char buffer[PATH_MAX], fname[PATH_MAX]; |
dba24537 AC |
3909 | |
3910 | sigemptyset (pending); | |
3911 | sigemptyset (blocked); | |
3912 | sigemptyset (ignored); | |
cde33bf1 | 3913 | xsnprintf (fname, sizeof fname, "/proc/%d/status", pid); |
d419f42d | 3914 | gdb_file_up procfile = gdb_fopen_cloexec (fname, "r"); |
dba24537 | 3915 | if (procfile == NULL) |
8a3fe4f8 | 3916 | error (_("Could not open %s"), fname); |
dba24537 | 3917 | |
d419f42d | 3918 | while (fgets (buffer, PATH_MAX, procfile.get ()) != NULL) |
dba24537 AC |
3919 | { |
3920 | /* Normal queued signals are on the SigPnd line in the status | |
3921 | file. However, 2.6 kernels also have a "shared" pending | |
3922 | queue for delivering signals to a thread group, so check for | |
3923 | a ShdPnd line also. | |
3924 | ||
3925 | Unfortunately some Red Hat kernels include the shared pending | |
3926 | queue but not the ShdPnd status field. */ | |
3927 | ||
61012eef | 3928 | if (startswith (buffer, "SigPnd:\t")) |
dba24537 | 3929 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 3930 | else if (startswith (buffer, "ShdPnd:\t")) |
dba24537 | 3931 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 3932 | else if (startswith (buffer, "SigBlk:\t")) |
dba24537 | 3933 | add_line_to_sigset (buffer + 8, blocked); |
61012eef | 3934 | else if (startswith (buffer, "SigIgn:\t")) |
dba24537 AC |
3935 | add_line_to_sigset (buffer + 8, ignored); |
3936 | } | |
dba24537 AC |
3937 | } |
3938 | ||
9b409511 | 3939 | static enum target_xfer_status |
f6ac5f3d | 3940 | linux_nat_xfer_osdata (enum target_object object, |
e0881a8e | 3941 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
3942 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
3943 | ULONGEST *xfered_len) | |
07e059b5 | 3944 | { |
07e059b5 VP |
3945 | gdb_assert (object == TARGET_OBJECT_OSDATA); |
3946 | ||
9b409511 YQ |
3947 | *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len); |
3948 | if (*xfered_len == 0) | |
3949 | return TARGET_XFER_EOF; | |
3950 | else | |
3951 | return TARGET_XFER_OK; | |
07e059b5 VP |
3952 | } |
3953 | ||
f6ac5f3d PA |
3954 | std::vector<static_tracepoint_marker> |
3955 | linux_nat_target::static_tracepoint_markers_by_strid (const char *strid) | |
5808517f YQ |
3956 | { |
3957 | char s[IPA_CMD_BUF_SIZE]; | |
e99b03dc | 3958 | int pid = inferior_ptid.pid (); |
5d9310c4 | 3959 | std::vector<static_tracepoint_marker> markers; |
256642e8 | 3960 | const char *p = s; |
fd79271b | 3961 | ptid_t ptid = ptid_t (pid, 0, 0); |
5d9310c4 | 3962 | static_tracepoint_marker marker; |
5808517f YQ |
3963 | |
3964 | /* Pause all */ | |
3965 | target_stop (ptid); | |
3966 | ||
3967 | memcpy (s, "qTfSTM", sizeof ("qTfSTM")); | |
3968 | s[sizeof ("qTfSTM")] = 0; | |
3969 | ||
42476b70 | 3970 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f | 3971 | |
1db93f14 TT |
3972 | /* Unpause all. */ |
3973 | SCOPE_EXIT { target_continue_no_signal (ptid); }; | |
5808517f YQ |
3974 | |
3975 | while (*p++ == 'm') | |
3976 | { | |
5808517f YQ |
3977 | do |
3978 | { | |
5d9310c4 | 3979 | parse_static_tracepoint_marker_definition (p, &p, &marker); |
5808517f | 3980 | |
5d9310c4 SM |
3981 | if (strid == NULL || marker.str_id == strid) |
3982 | markers.push_back (std::move (marker)); | |
5808517f YQ |
3983 | } |
3984 | while (*p++ == ','); /* comma-separated list */ | |
3985 | ||
3986 | memcpy (s, "qTsSTM", sizeof ("qTsSTM")); | |
3987 | s[sizeof ("qTsSTM")] = 0; | |
42476b70 | 3988 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
3989 | p = s; |
3990 | } | |
3991 | ||
5808517f YQ |
3992 | return markers; |
3993 | } | |
3994 | ||
b84876c2 PA |
3995 | /* target_is_async_p implementation. */ |
3996 | ||
57810aa7 | 3997 | bool |
f6ac5f3d | 3998 | linux_nat_target::is_async_p () |
b84876c2 | 3999 | { |
198297aa | 4000 | return linux_is_async_p (); |
b84876c2 PA |
4001 | } |
4002 | ||
4003 | /* target_can_async_p implementation. */ | |
4004 | ||
57810aa7 | 4005 | bool |
f6ac5f3d | 4006 | linux_nat_target::can_async_p () |
b84876c2 | 4007 | { |
fde1b17d SM |
4008 | /* We're always async, unless the user explicitly prevented it with the |
4009 | "maint set target-async" command. */ | |
3dd5b83d | 4010 | return target_async_permitted; |
b84876c2 PA |
4011 | } |
4012 | ||
57810aa7 | 4013 | bool |
f6ac5f3d | 4014 | linux_nat_target::supports_non_stop () |
9908b566 | 4015 | { |
f80c8ec4 | 4016 | return true; |
9908b566 VP |
4017 | } |
4018 | ||
fbea99ea PA |
4019 | /* to_always_non_stop_p implementation. */ |
4020 | ||
57810aa7 | 4021 | bool |
f6ac5f3d | 4022 | linux_nat_target::always_non_stop_p () |
fbea99ea | 4023 | { |
f80c8ec4 | 4024 | return true; |
fbea99ea PA |
4025 | } |
4026 | ||
57810aa7 | 4027 | bool |
f6ac5f3d | 4028 | linux_nat_target::supports_multi_process () |
d90e17a7 | 4029 | { |
aee91db3 | 4030 | return true; |
d90e17a7 PA |
4031 | } |
4032 | ||
57810aa7 | 4033 | bool |
f6ac5f3d | 4034 | linux_nat_target::supports_disable_randomization () |
03583c20 UW |
4035 | { |
4036 | #ifdef HAVE_PERSONALITY | |
f80c8ec4 | 4037 | return true; |
03583c20 | 4038 | #else |
f80c8ec4 | 4039 | return false; |
03583c20 UW |
4040 | #endif |
4041 | } | |
4042 | ||
7feb7d06 PA |
4043 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
4044 | so we notice when any child changes state, and notify the | |
4045 | event-loop; it allows us to use sigsuspend in linux_nat_wait_1 | |
4046 | above to wait for the arrival of a SIGCHLD. */ | |
4047 | ||
b84876c2 | 4048 | static void |
7feb7d06 | 4049 | sigchld_handler (int signo) |
b84876c2 | 4050 | { |
7feb7d06 PA |
4051 | int old_errno = errno; |
4052 | ||
01124a23 | 4053 | if (debug_linux_nat) |
da5bd37e | 4054 | gdb_stdlog->write_async_safe ("sigchld\n", sizeof ("sigchld\n") - 1); |
7feb7d06 PA |
4055 | |
4056 | if (signo == SIGCHLD | |
4057 | && linux_nat_event_pipe[0] != -1) | |
4058 | async_file_mark (); /* Let the event loop know that there are | |
4059 | events to handle. */ | |
4060 | ||
4061 | errno = old_errno; | |
4062 | } | |
4063 | ||
4064 | /* Callback registered with the target events file descriptor. */ | |
4065 | ||
4066 | static void | |
4067 | handle_target_event (int error, gdb_client_data client_data) | |
4068 | { | |
b1a35af2 | 4069 | inferior_event_handler (INF_REG_EVENT); |
7feb7d06 PA |
4070 | } |
4071 | ||
4072 | /* Create/destroy the target events pipe. Returns previous state. */ | |
4073 | ||
4074 | static int | |
4075 | linux_async_pipe (int enable) | |
4076 | { | |
198297aa | 4077 | int previous = linux_is_async_p (); |
7feb7d06 PA |
4078 | |
4079 | if (previous != enable) | |
4080 | { | |
4081 | sigset_t prev_mask; | |
4082 | ||
12696c10 PA |
4083 | /* Block child signals while we create/destroy the pipe, as |
4084 | their handler writes to it. */ | |
7feb7d06 PA |
4085 | block_child_signals (&prev_mask); |
4086 | ||
4087 | if (enable) | |
4088 | { | |
614c279d | 4089 | if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1) |
7feb7d06 PA |
4090 | internal_error (__FILE__, __LINE__, |
4091 | "creating event pipe failed."); | |
4092 | ||
4093 | fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK); | |
4094 | fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK); | |
4095 | } | |
4096 | else | |
4097 | { | |
4098 | close (linux_nat_event_pipe[0]); | |
4099 | close (linux_nat_event_pipe[1]); | |
4100 | linux_nat_event_pipe[0] = -1; | |
4101 | linux_nat_event_pipe[1] = -1; | |
4102 | } | |
4103 | ||
4104 | restore_child_signals_mask (&prev_mask); | |
4105 | } | |
4106 | ||
4107 | return previous; | |
b84876c2 PA |
4108 | } |
4109 | ||
5b6d1e4f PA |
4110 | int |
4111 | linux_nat_target::async_wait_fd () | |
4112 | { | |
4113 | return linux_nat_event_pipe[0]; | |
4114 | } | |
4115 | ||
b84876c2 PA |
4116 | /* target_async implementation. */ |
4117 | ||
f6ac5f3d PA |
4118 | void |
4119 | linux_nat_target::async (int enable) | |
b84876c2 | 4120 | { |
6a3753b3 | 4121 | if (enable) |
b84876c2 | 4122 | { |
7feb7d06 PA |
4123 | if (!linux_async_pipe (1)) |
4124 | { | |
4125 | add_file_handler (linux_nat_event_pipe[0], | |
2554f6f5 SM |
4126 | handle_target_event, NULL, |
4127 | "linux-nat"); | |
7feb7d06 PA |
4128 | /* There may be pending events to handle. Tell the event loop |
4129 | to poll them. */ | |
4130 | async_file_mark (); | |
4131 | } | |
b84876c2 PA |
4132 | } |
4133 | else | |
4134 | { | |
b84876c2 | 4135 | delete_file_handler (linux_nat_event_pipe[0]); |
7feb7d06 | 4136 | linux_async_pipe (0); |
b84876c2 PA |
4137 | } |
4138 | return; | |
4139 | } | |
4140 | ||
a493e3e2 | 4141 | /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other |
252fbfc8 PA |
4142 | event came out. */ |
4143 | ||
4c28f408 | 4144 | static int |
d3a70e03 | 4145 | linux_nat_stop_lwp (struct lwp_info *lwp) |
4c28f408 | 4146 | { |
d90e17a7 | 4147 | if (!lwp->stopped) |
252fbfc8 | 4148 | { |
9327494e SM |
4149 | linux_nat_debug_printf ("running -> suspending %s", |
4150 | target_pid_to_str (lwp->ptid).c_str ()); | |
252fbfc8 | 4151 | |
252fbfc8 | 4152 | |
25289eb2 PA |
4153 | if (lwp->last_resume_kind == resume_stop) |
4154 | { | |
9327494e SM |
4155 | linux_nat_debug_printf ("already stopping LWP %ld at GDB's request", |
4156 | lwp->ptid.lwp ()); | |
25289eb2 PA |
4157 | return 0; |
4158 | } | |
252fbfc8 | 4159 | |
d3a70e03 | 4160 | stop_callback (lwp); |
25289eb2 | 4161 | lwp->last_resume_kind = resume_stop; |
d90e17a7 PA |
4162 | } |
4163 | else | |
4164 | { | |
4165 | /* Already known to be stopped; do nothing. */ | |
252fbfc8 | 4166 | |
d90e17a7 PA |
4167 | if (debug_linux_nat) |
4168 | { | |
5b6d1e4f | 4169 | if (find_thread_ptid (linux_target, lwp->ptid)->stop_requested) |
9327494e SM |
4170 | linux_nat_debug_printf ("already stopped/stop_requested %s", |
4171 | target_pid_to_str (lwp->ptid).c_str ()); | |
d90e17a7 | 4172 | else |
9327494e SM |
4173 | linux_nat_debug_printf ("already stopped/no stop_requested yet %s", |
4174 | target_pid_to_str (lwp->ptid).c_str ()); | |
252fbfc8 PA |
4175 | } |
4176 | } | |
4c28f408 PA |
4177 | return 0; |
4178 | } | |
4179 | ||
f6ac5f3d PA |
4180 | void |
4181 | linux_nat_target::stop (ptid_t ptid) | |
4c28f408 | 4182 | { |
d3a70e03 | 4183 | iterate_over_lwps (ptid, linux_nat_stop_lwp); |
bfedc46a PA |
4184 | } |
4185 | ||
f6ac5f3d PA |
4186 | void |
4187 | linux_nat_target::close () | |
d90e17a7 PA |
4188 | { |
4189 | /* Unregister from the event loop. */ | |
f6ac5f3d PA |
4190 | if (is_async_p ()) |
4191 | async (0); | |
d90e17a7 | 4192 | |
f6ac5f3d | 4193 | inf_ptrace_target::close (); |
d90e17a7 PA |
4194 | } |
4195 | ||
c0694254 PA |
4196 | /* When requests are passed down from the linux-nat layer to the |
4197 | single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are | |
4198 | used. The address space pointer is stored in the inferior object, | |
4199 | but the common code that is passed such ptid can't tell whether | |
4200 | lwpid is a "main" process id or not (it assumes so). We reverse | |
4201 | look up the "main" process id from the lwp here. */ | |
4202 | ||
f6ac5f3d PA |
4203 | struct address_space * |
4204 | linux_nat_target::thread_address_space (ptid_t ptid) | |
c0694254 PA |
4205 | { |
4206 | struct lwp_info *lwp; | |
4207 | struct inferior *inf; | |
4208 | int pid; | |
4209 | ||
e38504b3 | 4210 | if (ptid.lwp () == 0) |
c0694254 PA |
4211 | { |
4212 | /* An (lwpid,0,0) ptid. Look up the lwp object to get at the | |
4213 | tgid. */ | |
4214 | lwp = find_lwp_pid (ptid); | |
e99b03dc | 4215 | pid = lwp->ptid.pid (); |
c0694254 PA |
4216 | } |
4217 | else | |
4218 | { | |
4219 | /* A (pid,lwpid,0) ptid. */ | |
e99b03dc | 4220 | pid = ptid.pid (); |
c0694254 PA |
4221 | } |
4222 | ||
5b6d1e4f | 4223 | inf = find_inferior_pid (this, pid); |
c0694254 PA |
4224 | gdb_assert (inf != NULL); |
4225 | return inf->aspace; | |
4226 | } | |
4227 | ||
dc146f7c VP |
4228 | /* Return the cached value of the processor core for thread PTID. */ |
4229 | ||
f6ac5f3d PA |
4230 | int |
4231 | linux_nat_target::core_of_thread (ptid_t ptid) | |
dc146f7c VP |
4232 | { |
4233 | struct lwp_info *info = find_lwp_pid (ptid); | |
e0881a8e | 4234 | |
dc146f7c VP |
4235 | if (info) |
4236 | return info->core; | |
4237 | return -1; | |
4238 | } | |
4239 | ||
7a6a1731 GB |
4240 | /* Implementation of to_filesystem_is_local. */ |
4241 | ||
57810aa7 | 4242 | bool |
f6ac5f3d | 4243 | linux_nat_target::filesystem_is_local () |
7a6a1731 GB |
4244 | { |
4245 | struct inferior *inf = current_inferior (); | |
4246 | ||
4247 | if (inf->fake_pid_p || inf->pid == 0) | |
57810aa7 | 4248 | return true; |
7a6a1731 GB |
4249 | |
4250 | return linux_ns_same (inf->pid, LINUX_NS_MNT); | |
4251 | } | |
4252 | ||
4253 | /* Convert the INF argument passed to a to_fileio_* method | |
4254 | to a process ID suitable for passing to its corresponding | |
4255 | linux_mntns_* function. If INF is non-NULL then the | |
4256 | caller is requesting the filesystem seen by INF. If INF | |
4257 | is NULL then the caller is requesting the filesystem seen | |
4258 | by the GDB. We fall back to GDB's filesystem in the case | |
4259 | that INF is non-NULL but its PID is unknown. */ | |
4260 | ||
4261 | static pid_t | |
4262 | linux_nat_fileio_pid_of (struct inferior *inf) | |
4263 | { | |
4264 | if (inf == NULL || inf->fake_pid_p || inf->pid == 0) | |
4265 | return getpid (); | |
4266 | else | |
4267 | return inf->pid; | |
4268 | } | |
4269 | ||
4270 | /* Implementation of to_fileio_open. */ | |
4271 | ||
f6ac5f3d PA |
4272 | int |
4273 | linux_nat_target::fileio_open (struct inferior *inf, const char *filename, | |
4274 | int flags, int mode, int warn_if_slow, | |
4275 | int *target_errno) | |
7a6a1731 GB |
4276 | { |
4277 | int nat_flags; | |
4278 | mode_t nat_mode; | |
4279 | int fd; | |
4280 | ||
4281 | if (fileio_to_host_openflags (flags, &nat_flags) == -1 | |
4282 | || fileio_to_host_mode (mode, &nat_mode) == -1) | |
4283 | { | |
4284 | *target_errno = FILEIO_EINVAL; | |
4285 | return -1; | |
4286 | } | |
4287 | ||
4288 | fd = linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf), | |
4289 | filename, nat_flags, nat_mode); | |
4290 | if (fd == -1) | |
4291 | *target_errno = host_to_fileio_error (errno); | |
4292 | ||
4293 | return fd; | |
4294 | } | |
4295 | ||
4296 | /* Implementation of to_fileio_readlink. */ | |
4297 | ||
f6ac5f3d PA |
4298 | gdb::optional<std::string> |
4299 | linux_nat_target::fileio_readlink (struct inferior *inf, const char *filename, | |
4300 | int *target_errno) | |
7a6a1731 GB |
4301 | { |
4302 | char buf[PATH_MAX]; | |
4303 | int len; | |
7a6a1731 GB |
4304 | |
4305 | len = linux_mntns_readlink (linux_nat_fileio_pid_of (inf), | |
4306 | filename, buf, sizeof (buf)); | |
4307 | if (len < 0) | |
4308 | { | |
4309 | *target_errno = host_to_fileio_error (errno); | |
e0d3522b | 4310 | return {}; |
7a6a1731 GB |
4311 | } |
4312 | ||
e0d3522b | 4313 | return std::string (buf, len); |
7a6a1731 GB |
4314 | } |
4315 | ||
4316 | /* Implementation of to_fileio_unlink. */ | |
4317 | ||
f6ac5f3d PA |
4318 | int |
4319 | linux_nat_target::fileio_unlink (struct inferior *inf, const char *filename, | |
4320 | int *target_errno) | |
7a6a1731 GB |
4321 | { |
4322 | int ret; | |
4323 | ||
4324 | ret = linux_mntns_unlink (linux_nat_fileio_pid_of (inf), | |
4325 | filename); | |
4326 | if (ret == -1) | |
4327 | *target_errno = host_to_fileio_error (errno); | |
4328 | ||
4329 | return ret; | |
4330 | } | |
4331 | ||
aa01bd36 PA |
4332 | /* Implementation of the to_thread_events method. */ |
4333 | ||
f6ac5f3d PA |
4334 | void |
4335 | linux_nat_target::thread_events (int enable) | |
aa01bd36 PA |
4336 | { |
4337 | report_thread_events = enable; | |
4338 | } | |
4339 | ||
f6ac5f3d PA |
4340 | linux_nat_target::linux_nat_target () |
4341 | { | |
f973ed9c DJ |
4342 | /* We don't change the stratum; this target will sit at |
4343 | process_stratum and thread_db will set at thread_stratum. This | |
4344 | is a little strange, since this is a multi-threaded-capable | |
4345 | target, but we want to be on the stack below thread_db, and we | |
4346 | also want to be used for single-threaded processes. */ | |
f973ed9c DJ |
4347 | } |
4348 | ||
f865ee35 JK |
4349 | /* See linux-nat.h. */ |
4350 | ||
4351 | int | |
4352 | linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo) | |
9f0bdab8 | 4353 | { |
da559b09 | 4354 | int pid; |
9f0bdab8 | 4355 | |
e38504b3 | 4356 | pid = ptid.lwp (); |
da559b09 | 4357 | if (pid == 0) |
e99b03dc | 4358 | pid = ptid.pid (); |
f865ee35 | 4359 | |
da559b09 JK |
4360 | errno = 0; |
4361 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo); | |
4362 | if (errno != 0) | |
4363 | { | |
4364 | memset (siginfo, 0, sizeof (*siginfo)); | |
4365 | return 0; | |
4366 | } | |
f865ee35 | 4367 | return 1; |
9f0bdab8 DJ |
4368 | } |
4369 | ||
7b669087 GB |
4370 | /* See nat/linux-nat.h. */ |
4371 | ||
4372 | ptid_t | |
4373 | current_lwp_ptid (void) | |
4374 | { | |
15a9e13e | 4375 | gdb_assert (inferior_ptid.lwp_p ()); |
7b669087 GB |
4376 | return inferior_ptid; |
4377 | } | |
4378 | ||
6c265988 | 4379 | void _initialize_linux_nat (); |
d6b0e80f | 4380 | void |
6c265988 | 4381 | _initialize_linux_nat () |
d6b0e80f | 4382 | { |
ccce17b0 YQ |
4383 | add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance, |
4384 | &debug_linux_nat, _("\ | |
b84876c2 PA |
4385 | Set debugging of GNU/Linux lwp module."), _("\ |
4386 | Show debugging of GNU/Linux lwp module."), _("\ | |
4387 | Enables printf debugging output."), | |
ccce17b0 YQ |
4388 | NULL, |
4389 | show_debug_linux_nat, | |
4390 | &setdebuglist, &showdebuglist); | |
b84876c2 | 4391 | |
7a6a1731 GB |
4392 | add_setshow_boolean_cmd ("linux-namespaces", class_maintenance, |
4393 | &debug_linux_namespaces, _("\ | |
4394 | Set debugging of GNU/Linux namespaces module."), _("\ | |
4395 | Show debugging of GNU/Linux namespaces module."), _("\ | |
4396 | Enables printf debugging output."), | |
4397 | NULL, | |
4398 | NULL, | |
4399 | &setdebuglist, &showdebuglist); | |
4400 | ||
7feb7d06 PA |
4401 | /* Install a SIGCHLD handler. */ |
4402 | sigchld_action.sa_handler = sigchld_handler; | |
4403 | sigemptyset (&sigchld_action.sa_mask); | |
4404 | sigchld_action.sa_flags = SA_RESTART; | |
b84876c2 PA |
4405 | |
4406 | /* Make it the default. */ | |
7feb7d06 | 4407 | sigaction (SIGCHLD, &sigchld_action, NULL); |
d6b0e80f AC |
4408 | |
4409 | /* Make sure we don't block SIGCHLD during a sigsuspend. */ | |
21987b9c | 4410 | gdb_sigmask (SIG_SETMASK, NULL, &suspend_mask); |
d6b0e80f AC |
4411 | sigdelset (&suspend_mask, SIGCHLD); |
4412 | ||
7feb7d06 | 4413 | sigemptyset (&blocked_mask); |
774113b0 PA |
4414 | |
4415 | lwp_lwpid_htab_create (); | |
d6b0e80f AC |
4416 | } |
4417 | \f | |
4418 | ||
4419 | /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to | |
4420 | the GNU/Linux Threads library and therefore doesn't really belong | |
4421 | here. */ | |
4422 | ||
d6b0e80f AC |
4423 | /* Return the set of signals used by the threads library in *SET. */ |
4424 | ||
4425 | void | |
4426 | lin_thread_get_thread_signals (sigset_t *set) | |
4427 | { | |
d6b0e80f AC |
4428 | sigemptyset (set); |
4429 | ||
4a6ed09b PA |
4430 | /* NPTL reserves the first two RT signals, but does not provide any |
4431 | way for the debugger to query the signal numbers - fortunately | |
4432 | they don't change. */ | |
4433 | sigaddset (set, __SIGRTMIN); | |
4434 | sigaddset (set, __SIGRTMIN + 1); | |
d6b0e80f | 4435 | } |