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3993f6b1 | 1 | /* GNU/Linux native-dependent code common to multiple platforms. |
dba24537 | 2 | |
4a94e368 | 3 | Copyright (C) 2001-2022 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" |
b146ba14 | 68 | #include "gdbsupport/block-signals.h" |
268a13a5 TT |
69 | #include "gdbsupport/fileio.h" |
70 | #include "gdbsupport/scope-exit.h" | |
21987b9c | 71 | #include "gdbsupport/gdb-sigmask.h" |
ba988419 | 72 | #include "gdbsupport/common-debug.h" |
8a89ddbd | 73 | #include <unordered_map> |
efcbbd14 | 74 | |
1777feb0 | 75 | /* This comment documents high-level logic of this file. |
8a77dff3 VP |
76 | |
77 | Waiting for events in sync mode | |
78 | =============================== | |
79 | ||
4a6ed09b PA |
80 | When waiting for an event in a specific thread, we just use waitpid, |
81 | passing the specific pid, and not passing WNOHANG. | |
82 | ||
83 | When waiting for an event in all threads, waitpid is not quite good: | |
84 | ||
85 | - If the thread group leader exits while other threads in the thread | |
86 | group still exist, waitpid(TGID, ...) hangs. That waitpid won't | |
87 | return an exit status until the other threads in the group are | |
88 | reaped. | |
89 | ||
90 | - When a non-leader thread execs, that thread just vanishes without | |
91 | reporting an exit (so we'd hang if we waited for it explicitly in | |
92 | that case). The exec event is instead reported to the TGID pid. | |
93 | ||
94 | The solution is to always use -1 and WNOHANG, together with | |
95 | sigsuspend. | |
96 | ||
97 | First, we use non-blocking waitpid to check for events. If nothing is | |
98 | found, we use sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, | |
99 | it means something happened to a child process. As soon as we know | |
100 | there's an event, we get back to calling nonblocking waitpid. | |
101 | ||
102 | Note that SIGCHLD should be blocked between waitpid and sigsuspend | |
103 | calls, so that we don't miss a signal. If SIGCHLD arrives in between, | |
104 | when it's blocked, the signal becomes pending and sigsuspend | |
105 | immediately notices it and returns. | |
106 | ||
107 | Waiting for events in async mode (TARGET_WNOHANG) | |
108 | ================================================= | |
8a77dff3 | 109 | |
7feb7d06 PA |
110 | In async mode, GDB should always be ready to handle both user input |
111 | and target events, so neither blocking waitpid nor sigsuspend are | |
112 | viable options. Instead, we should asynchronously notify the GDB main | |
113 | event loop whenever there's an unprocessed event from the target. We | |
114 | detect asynchronous target events by handling SIGCHLD signals. To | |
c150bdf0 JB |
115 | notify the event loop about target events, an event pipe is used |
116 | --- the pipe is registered as waitable event source in the event loop, | |
7feb7d06 | 117 | the event loop select/poll's on the read end of this pipe (as well on |
c150bdf0 JB |
118 | other event sources, e.g., stdin), and the SIGCHLD handler marks the |
119 | event pipe to raise an event. This is more portable than relying on | |
7feb7d06 PA |
120 | pselect/ppoll, since on kernels that lack those syscalls, libc |
121 | emulates them with select/poll+sigprocmask, and that is racy | |
122 | (a.k.a. plain broken). | |
123 | ||
124 | Obviously, if we fail to notify the event loop if there's a target | |
125 | event, it's bad. OTOH, if we notify the event loop when there's no | |
126 | event from the target, linux_nat_wait will detect that there's no real | |
127 | event to report, and return event of type TARGET_WAITKIND_IGNORE. | |
128 | This is mostly harmless, but it will waste time and is better avoided. | |
129 | ||
130 | The main design point is that every time GDB is outside linux-nat.c, | |
131 | we have a SIGCHLD handler installed that is called when something | |
132 | happens to the target and notifies the GDB event loop. Whenever GDB | |
133 | core decides to handle the event, and calls into linux-nat.c, we | |
134 | process things as in sync mode, except that the we never block in | |
135 | sigsuspend. | |
136 | ||
137 | While processing an event, we may end up momentarily blocked in | |
138 | waitpid calls. Those waitpid calls, while blocking, are guarantied to | |
139 | return quickly. E.g., in all-stop mode, before reporting to the core | |
140 | that an LWP hit a breakpoint, all LWPs are stopped by sending them | |
141 | SIGSTOP, and synchronously waiting for the SIGSTOP to be reported. | |
142 | Note that this is different from blocking indefinitely waiting for the | |
143 | next event --- here, we're already handling an event. | |
8a77dff3 VP |
144 | |
145 | Use of signals | |
146 | ============== | |
147 | ||
148 | We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another | |
149 | signal is not entirely significant; we just need for a signal to be delivered, | |
150 | so that we can intercept it. SIGSTOP's advantage is that it can not be | |
151 | blocked. A disadvantage is that it is not a real-time signal, so it can only | |
152 | be queued once; we do not keep track of other sources of SIGSTOP. | |
153 | ||
154 | Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't | |
155 | use them, because they have special behavior when the signal is generated - | |
156 | not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL | |
157 | kills the entire thread group. | |
158 | ||
159 | A delivered SIGSTOP would stop the entire thread group, not just the thread we | |
160 | tkill'd. But we never let the SIGSTOP be delivered; we always intercept and | |
161 | cancel it (by PTRACE_CONT without passing SIGSTOP). | |
162 | ||
163 | We could use a real-time signal instead. This would solve those problems; we | |
164 | could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB. | |
165 | But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH | |
166 | generates it, and there are races with trying to find a signal that is not | |
4a6ed09b PA |
167 | blocked. |
168 | ||
169 | Exec events | |
170 | =========== | |
171 | ||
172 | The case of a thread group (process) with 3 or more threads, and a | |
173 | thread other than the leader execs is worth detailing: | |
174 | ||
175 | On an exec, the Linux kernel destroys all threads except the execing | |
176 | one in the thread group, and resets the execing thread's tid to the | |
177 | tgid. No exit notification is sent for the execing thread -- from the | |
178 | ptracer's perspective, it appears as though the execing thread just | |
179 | vanishes. Until we reap all other threads except the leader and the | |
180 | execing thread, the leader will be zombie, and the execing thread will | |
181 | be in `D (disc sleep)' state. As soon as all other threads are | |
182 | reaped, the execing thread changes its tid to the tgid, and the | |
183 | previous (zombie) leader vanishes, giving place to the "new" | |
184 | leader. */ | |
a0ef4274 | 185 | |
dba24537 AC |
186 | #ifndef O_LARGEFILE |
187 | #define O_LARGEFILE 0 | |
188 | #endif | |
0274a8ce | 189 | |
f6ac5f3d PA |
190 | struct linux_nat_target *linux_target; |
191 | ||
433bbbf8 | 192 | /* Does the current host support PTRACE_GETREGSET? */ |
0bdb2f78 | 193 | enum tribool have_ptrace_getregset = TRIBOOL_UNKNOWN; |
433bbbf8 | 194 | |
b6e52a0b AB |
195 | /* When true, print debug messages relating to the linux native target. */ |
196 | ||
197 | static bool debug_linux_nat; | |
198 | ||
8864ef42 | 199 | /* Implement 'show debug linux-nat'. */ |
b6e52a0b | 200 | |
920d2a44 AC |
201 | static void |
202 | show_debug_linux_nat (struct ui_file *file, int from_tty, | |
203 | struct cmd_list_element *c, const char *value) | |
204 | { | |
6cb06a8c TT |
205 | gdb_printf (file, _("Debugging of GNU/Linux native targets is %s.\n"), |
206 | value); | |
920d2a44 | 207 | } |
d6b0e80f | 208 | |
17417fb0 | 209 | /* Print a linux-nat debug statement. */ |
9327494e SM |
210 | |
211 | #define linux_nat_debug_printf(fmt, ...) \ | |
74b773fc | 212 | debug_prefixed_printf_cond (debug_linux_nat, "linux-nat", fmt, ##__VA_ARGS__) |
9327494e | 213 | |
b6e52a0b AB |
214 | /* Print "linux-nat" enter/exit debug statements. */ |
215 | ||
216 | #define LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT \ | |
217 | scoped_debug_enter_exit (debug_linux_nat, "linux-nat") | |
218 | ||
ae087d01 DJ |
219 | struct simple_pid_list |
220 | { | |
221 | int pid; | |
3d799a95 | 222 | int status; |
ae087d01 DJ |
223 | struct simple_pid_list *next; |
224 | }; | |
05c309a8 | 225 | static struct simple_pid_list *stopped_pids; |
ae087d01 | 226 | |
aa01bd36 PA |
227 | /* Whether target_thread_events is in effect. */ |
228 | static int report_thread_events; | |
229 | ||
7feb7d06 PA |
230 | static int kill_lwp (int lwpid, int signo); |
231 | ||
d3a70e03 | 232 | static int stop_callback (struct lwp_info *lp); |
7feb7d06 PA |
233 | |
234 | static void block_child_signals (sigset_t *prev_mask); | |
235 | static void restore_child_signals_mask (sigset_t *prev_mask); | |
2277426b PA |
236 | |
237 | struct lwp_info; | |
238 | static struct lwp_info *add_lwp (ptid_t ptid); | |
239 | static void purge_lwp_list (int pid); | |
4403d8e9 | 240 | static void delete_lwp (ptid_t ptid); |
2277426b PA |
241 | static struct lwp_info *find_lwp_pid (ptid_t ptid); |
242 | ||
8a99810d PA |
243 | static int lwp_status_pending_p (struct lwp_info *lp); |
244 | ||
e7ad2f14 PA |
245 | static void save_stop_reason (struct lwp_info *lp); |
246 | ||
1bcb0708 | 247 | static bool proc_mem_file_is_writable (); |
8a89ddbd PA |
248 | static void close_proc_mem_file (pid_t pid); |
249 | static void open_proc_mem_file (ptid_t ptid); | |
05c06f31 | 250 | |
6cf20c46 PA |
251 | /* Return TRUE if LWP is the leader thread of the process. */ |
252 | ||
253 | static bool | |
254 | is_leader (lwp_info *lp) | |
255 | { | |
256 | return lp->ptid.pid () == lp->ptid.lwp (); | |
257 | } | |
258 | ||
cff068da GB |
259 | \f |
260 | /* LWP accessors. */ | |
261 | ||
262 | /* See nat/linux-nat.h. */ | |
263 | ||
264 | ptid_t | |
265 | ptid_of_lwp (struct lwp_info *lwp) | |
266 | { | |
267 | return lwp->ptid; | |
268 | } | |
269 | ||
270 | /* See nat/linux-nat.h. */ | |
271 | ||
4b134ca1 GB |
272 | void |
273 | lwp_set_arch_private_info (struct lwp_info *lwp, | |
274 | struct arch_lwp_info *info) | |
275 | { | |
276 | lwp->arch_private = info; | |
277 | } | |
278 | ||
279 | /* See nat/linux-nat.h. */ | |
280 | ||
281 | struct arch_lwp_info * | |
282 | lwp_arch_private_info (struct lwp_info *lwp) | |
283 | { | |
284 | return lwp->arch_private; | |
285 | } | |
286 | ||
287 | /* See nat/linux-nat.h. */ | |
288 | ||
cff068da GB |
289 | int |
290 | lwp_is_stopped (struct lwp_info *lwp) | |
291 | { | |
292 | return lwp->stopped; | |
293 | } | |
294 | ||
295 | /* See nat/linux-nat.h. */ | |
296 | ||
297 | enum target_stop_reason | |
298 | lwp_stop_reason (struct lwp_info *lwp) | |
299 | { | |
300 | return lwp->stop_reason; | |
301 | } | |
302 | ||
0e00e962 AA |
303 | /* See nat/linux-nat.h. */ |
304 | ||
305 | int | |
306 | lwp_is_stepping (struct lwp_info *lwp) | |
307 | { | |
308 | return lwp->step; | |
309 | } | |
310 | ||
ae087d01 DJ |
311 | \f |
312 | /* Trivial list manipulation functions to keep track of a list of | |
313 | new stopped processes. */ | |
314 | static void | |
3d799a95 | 315 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
ae087d01 | 316 | { |
8d749320 | 317 | struct simple_pid_list *new_pid = XNEW (struct simple_pid_list); |
e0881a8e | 318 | |
ae087d01 | 319 | new_pid->pid = pid; |
3d799a95 | 320 | new_pid->status = status; |
ae087d01 DJ |
321 | new_pid->next = *listp; |
322 | *listp = new_pid; | |
323 | } | |
324 | ||
325 | static int | |
46a96992 | 326 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
ae087d01 DJ |
327 | { |
328 | struct simple_pid_list **p; | |
329 | ||
330 | for (p = listp; *p != NULL; p = &(*p)->next) | |
331 | if ((*p)->pid == pid) | |
332 | { | |
333 | struct simple_pid_list *next = (*p)->next; | |
e0881a8e | 334 | |
46a96992 | 335 | *statusp = (*p)->status; |
ae087d01 DJ |
336 | xfree (*p); |
337 | *p = next; | |
338 | return 1; | |
339 | } | |
340 | return 0; | |
341 | } | |
342 | ||
de0d863e DB |
343 | /* Return the ptrace options that we want to try to enable. */ |
344 | ||
345 | static int | |
346 | linux_nat_ptrace_options (int attached) | |
347 | { | |
348 | int options = 0; | |
349 | ||
350 | if (!attached) | |
351 | options |= PTRACE_O_EXITKILL; | |
352 | ||
353 | options |= (PTRACE_O_TRACESYSGOOD | |
354 | | PTRACE_O_TRACEVFORKDONE | |
355 | | PTRACE_O_TRACEVFORK | |
356 | | PTRACE_O_TRACEFORK | |
357 | | PTRACE_O_TRACEEXEC); | |
358 | ||
359 | return options; | |
360 | } | |
361 | ||
1b919490 VB |
362 | /* Initialize ptrace and procfs warnings and check for supported |
363 | ptrace features given PID. | |
beed38b8 JB |
364 | |
365 | ATTACHED should be nonzero iff we attached to the inferior. */ | |
3993f6b1 DJ |
366 | |
367 | static void | |
1b919490 | 368 | linux_init_ptrace_procfs (pid_t pid, int attached) |
3993f6b1 | 369 | { |
de0d863e DB |
370 | int options = linux_nat_ptrace_options (attached); |
371 | ||
372 | linux_enable_event_reporting (pid, options); | |
96d7229d | 373 | linux_ptrace_init_warnings (); |
1b919490 | 374 | linux_proc_init_warnings (); |
4de4c07c DJ |
375 | } |
376 | ||
f6ac5f3d PA |
377 | linux_nat_target::~linux_nat_target () |
378 | {} | |
379 | ||
380 | void | |
381 | linux_nat_target::post_attach (int pid) | |
4de4c07c | 382 | { |
1b919490 | 383 | linux_init_ptrace_procfs (pid, 1); |
4de4c07c DJ |
384 | } |
385 | ||
200fd287 AB |
386 | /* Implement the virtual inf_ptrace_target::post_startup_inferior method. */ |
387 | ||
f6ac5f3d PA |
388 | void |
389 | linux_nat_target::post_startup_inferior (ptid_t ptid) | |
4de4c07c | 390 | { |
1b919490 | 391 | linux_init_ptrace_procfs (ptid.pid (), 0); |
4de4c07c DJ |
392 | } |
393 | ||
4403d8e9 JK |
394 | /* Return the number of known LWPs in the tgid given by PID. */ |
395 | ||
396 | static int | |
397 | num_lwps (int pid) | |
398 | { | |
399 | int count = 0; | |
4403d8e9 | 400 | |
901b9821 | 401 | for (const lwp_info *lp ATTRIBUTE_UNUSED : all_lwps ()) |
e99b03dc | 402 | if (lp->ptid.pid () == pid) |
4403d8e9 JK |
403 | count++; |
404 | ||
405 | return count; | |
406 | } | |
407 | ||
169bb27b | 408 | /* Deleter for lwp_info unique_ptr specialisation. */ |
4403d8e9 | 409 | |
169bb27b | 410 | struct lwp_deleter |
4403d8e9 | 411 | { |
169bb27b AB |
412 | void operator() (struct lwp_info *lwp) const |
413 | { | |
414 | delete_lwp (lwp->ptid); | |
415 | } | |
416 | }; | |
4403d8e9 | 417 | |
169bb27b AB |
418 | /* A unique_ptr specialisation for lwp_info. */ |
419 | ||
420 | typedef std::unique_ptr<struct lwp_info, lwp_deleter> lwp_info_up; | |
4403d8e9 | 421 | |
82d1f134 | 422 | /* Target hook for follow_fork. */ |
d83ad864 | 423 | |
e97007b6 | 424 | void |
82d1f134 SM |
425 | linux_nat_target::follow_fork (inferior *child_inf, ptid_t child_ptid, |
426 | target_waitkind fork_kind, bool follow_child, | |
427 | bool detach_fork) | |
3993f6b1 | 428 | { |
82d1f134 SM |
429 | inf_ptrace_target::follow_fork (child_inf, child_ptid, fork_kind, |
430 | follow_child, detach_fork); | |
431 | ||
d83ad864 | 432 | if (!follow_child) |
4de4c07c | 433 | { |
3a849a34 SM |
434 | bool has_vforked = fork_kind == TARGET_WAITKIND_VFORKED; |
435 | ptid_t parent_ptid = inferior_ptid; | |
3a849a34 SM |
436 | int parent_pid = parent_ptid.lwp (); |
437 | int child_pid = child_ptid.lwp (); | |
4de4c07c | 438 | |
1777feb0 | 439 | /* We're already attached to the parent, by default. */ |
3a849a34 | 440 | lwp_info *child_lp = add_lwp (child_ptid); |
d83ad864 DB |
441 | child_lp->stopped = 1; |
442 | child_lp->last_resume_kind = resume_stop; | |
4de4c07c | 443 | |
ac264b3b MS |
444 | /* Detach new forked process? */ |
445 | if (detach_fork) | |
f75c00e4 | 446 | { |
95347337 AB |
447 | int child_stop_signal = 0; |
448 | bool detach_child = true; | |
4403d8e9 | 449 | |
169bb27b AB |
450 | /* Move CHILD_LP into a unique_ptr and clear the source pointer |
451 | to prevent us doing anything stupid with it. */ | |
452 | lwp_info_up child_lp_ptr (child_lp); | |
453 | child_lp = nullptr; | |
454 | ||
455 | linux_target->low_prepare_to_resume (child_lp_ptr.get ()); | |
c077881a HZ |
456 | |
457 | /* When debugging an inferior in an architecture that supports | |
458 | hardware single stepping on a kernel without commit | |
459 | 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child | |
460 | process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits | |
461 | set if the parent process had them set. | |
462 | To work around this, single step the child process | |
463 | once before detaching to clear the flags. */ | |
464 | ||
2fd9d7ca PA |
465 | /* Note that we consult the parent's architecture instead of |
466 | the child's because there's no inferior for the child at | |
467 | this point. */ | |
c077881a | 468 | if (!gdbarch_software_single_step_p (target_thread_architecture |
2fd9d7ca | 469 | (parent_ptid))) |
c077881a | 470 | { |
95347337 AB |
471 | int status; |
472 | ||
c077881a HZ |
473 | linux_disable_event_reporting (child_pid); |
474 | if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0) | |
475 | perror_with_name (_("Couldn't do single step")); | |
476 | if (my_waitpid (child_pid, &status, 0) < 0) | |
477 | perror_with_name (_("Couldn't wait vfork process")); | |
95347337 AB |
478 | else |
479 | { | |
480 | detach_child = WIFSTOPPED (status); | |
481 | child_stop_signal = WSTOPSIG (status); | |
482 | } | |
c077881a HZ |
483 | } |
484 | ||
95347337 | 485 | if (detach_child) |
9caaaa83 | 486 | { |
95347337 | 487 | int signo = child_stop_signal; |
9caaaa83 | 488 | |
9caaaa83 PA |
489 | if (signo != 0 |
490 | && !signal_pass_state (gdb_signal_from_host (signo))) | |
491 | signo = 0; | |
492 | ptrace (PTRACE_DETACH, child_pid, 0, signo); | |
8a89ddbd PA |
493 | |
494 | close_proc_mem_file (child_pid); | |
9caaaa83 | 495 | } |
ac264b3b | 496 | } |
9016a515 DJ |
497 | |
498 | if (has_vforked) | |
499 | { | |
a2885186 SM |
500 | lwp_info *parent_lp = find_lwp_pid (parent_ptid); |
501 | linux_nat_debug_printf ("waiting for VFORK_DONE on %d", parent_pid); | |
502 | parent_lp->stopped = 1; | |
6c95b8df | 503 | |
a2885186 SM |
504 | /* We'll handle the VFORK_DONE event like any other |
505 | event, in target_wait. */ | |
9016a515 | 506 | } |
4de4c07c | 507 | } |
3993f6b1 | 508 | else |
4de4c07c | 509 | { |
3ced3da4 | 510 | struct lwp_info *child_lp; |
4de4c07c | 511 | |
82d1f134 | 512 | child_lp = add_lwp (child_ptid); |
3ced3da4 | 513 | child_lp->stopped = 1; |
25289eb2 | 514 | child_lp->last_resume_kind = resume_stop; |
4de4c07c | 515 | } |
4de4c07c DJ |
516 | } |
517 | ||
4de4c07c | 518 | \f |
f6ac5f3d PA |
519 | int |
520 | linux_nat_target::insert_fork_catchpoint (int pid) | |
4de4c07c | 521 | { |
a2885186 | 522 | return 0; |
3993f6b1 DJ |
523 | } |
524 | ||
f6ac5f3d PA |
525 | int |
526 | linux_nat_target::remove_fork_catchpoint (int pid) | |
eb73ad13 PA |
527 | { |
528 | return 0; | |
529 | } | |
530 | ||
f6ac5f3d PA |
531 | int |
532 | linux_nat_target::insert_vfork_catchpoint (int pid) | |
3993f6b1 | 533 | { |
a2885186 | 534 | return 0; |
3993f6b1 DJ |
535 | } |
536 | ||
f6ac5f3d PA |
537 | int |
538 | linux_nat_target::remove_vfork_catchpoint (int pid) | |
eb73ad13 PA |
539 | { |
540 | return 0; | |
541 | } | |
542 | ||
f6ac5f3d PA |
543 | int |
544 | linux_nat_target::insert_exec_catchpoint (int pid) | |
3993f6b1 | 545 | { |
a2885186 | 546 | return 0; |
3993f6b1 DJ |
547 | } |
548 | ||
f6ac5f3d PA |
549 | int |
550 | linux_nat_target::remove_exec_catchpoint (int pid) | |
eb73ad13 PA |
551 | { |
552 | return 0; | |
553 | } | |
554 | ||
f6ac5f3d PA |
555 | int |
556 | linux_nat_target::set_syscall_catchpoint (int pid, bool needed, int any_count, | |
557 | gdb::array_view<const int> syscall_counts) | |
a96d9b2e | 558 | { |
a96d9b2e SDJ |
559 | /* On GNU/Linux, we ignore the arguments. It means that we only |
560 | enable the syscall catchpoints, but do not disable them. | |
77b06cd7 | 561 | |
649a140c | 562 | Also, we do not use the `syscall_counts' information because we do not |
a96d9b2e SDJ |
563 | filter system calls here. We let GDB do the logic for us. */ |
564 | return 0; | |
565 | } | |
566 | ||
774113b0 PA |
567 | /* List of known LWPs, keyed by LWP PID. This speeds up the common |
568 | case of mapping a PID returned from the kernel to our corresponding | |
569 | lwp_info data structure. */ | |
570 | static htab_t lwp_lwpid_htab; | |
571 | ||
572 | /* Calculate a hash from a lwp_info's LWP PID. */ | |
573 | ||
574 | static hashval_t | |
575 | lwp_info_hash (const void *ap) | |
576 | { | |
577 | const struct lwp_info *lp = (struct lwp_info *) ap; | |
e38504b3 | 578 | pid_t pid = lp->ptid.lwp (); |
774113b0 PA |
579 | |
580 | return iterative_hash_object (pid, 0); | |
581 | } | |
582 | ||
583 | /* Equality function for the lwp_info hash table. Compares the LWP's | |
584 | PID. */ | |
585 | ||
586 | static int | |
587 | lwp_lwpid_htab_eq (const void *a, const void *b) | |
588 | { | |
589 | const struct lwp_info *entry = (const struct lwp_info *) a; | |
590 | const struct lwp_info *element = (const struct lwp_info *) b; | |
591 | ||
e38504b3 | 592 | return entry->ptid.lwp () == element->ptid.lwp (); |
774113b0 PA |
593 | } |
594 | ||
595 | /* Create the lwp_lwpid_htab hash table. */ | |
596 | ||
597 | static void | |
598 | lwp_lwpid_htab_create (void) | |
599 | { | |
600 | lwp_lwpid_htab = htab_create (100, lwp_info_hash, lwp_lwpid_htab_eq, NULL); | |
601 | } | |
602 | ||
603 | /* Add LP to the hash table. */ | |
604 | ||
605 | static void | |
606 | lwp_lwpid_htab_add_lwp (struct lwp_info *lp) | |
607 | { | |
608 | void **slot; | |
609 | ||
610 | slot = htab_find_slot (lwp_lwpid_htab, lp, INSERT); | |
611 | gdb_assert (slot != NULL && *slot == NULL); | |
612 | *slot = lp; | |
613 | } | |
614 | ||
615 | /* Head of doubly-linked list of known LWPs. Sorted by reverse | |
616 | creation order. This order is assumed in some cases. E.g., | |
617 | reaping status after killing alls lwps of a process: the leader LWP | |
618 | must be reaped last. */ | |
901b9821 SM |
619 | |
620 | static intrusive_list<lwp_info> lwp_list; | |
621 | ||
622 | /* See linux-nat.h. */ | |
623 | ||
624 | lwp_info_range | |
625 | all_lwps () | |
626 | { | |
627 | return lwp_info_range (lwp_list.begin ()); | |
628 | } | |
629 | ||
630 | /* See linux-nat.h. */ | |
631 | ||
632 | lwp_info_safe_range | |
633 | all_lwps_safe () | |
634 | { | |
635 | return lwp_info_safe_range (lwp_list.begin ()); | |
636 | } | |
774113b0 PA |
637 | |
638 | /* Add LP to sorted-by-reverse-creation-order doubly-linked list. */ | |
639 | ||
640 | static void | |
641 | lwp_list_add (struct lwp_info *lp) | |
642 | { | |
901b9821 | 643 | lwp_list.push_front (*lp); |
774113b0 PA |
644 | } |
645 | ||
646 | /* Remove LP from sorted-by-reverse-creation-order doubly-linked | |
647 | list. */ | |
648 | ||
649 | static void | |
650 | lwp_list_remove (struct lwp_info *lp) | |
651 | { | |
652 | /* Remove from sorted-by-creation-order list. */ | |
901b9821 | 653 | lwp_list.erase (lwp_list.iterator_to (*lp)); |
774113b0 PA |
654 | } |
655 | ||
d6b0e80f AC |
656 | \f |
657 | ||
d6b0e80f AC |
658 | /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in |
659 | _initialize_linux_nat. */ | |
660 | static sigset_t suspend_mask; | |
661 | ||
7feb7d06 PA |
662 | /* Signals to block to make that sigsuspend work. */ |
663 | static sigset_t blocked_mask; | |
664 | ||
665 | /* SIGCHLD action. */ | |
6bd434d6 | 666 | static struct sigaction sigchld_action; |
b84876c2 | 667 | |
7feb7d06 PA |
668 | /* Block child signals (SIGCHLD and linux threads signals), and store |
669 | the previous mask in PREV_MASK. */ | |
84e46146 | 670 | |
7feb7d06 PA |
671 | static void |
672 | block_child_signals (sigset_t *prev_mask) | |
673 | { | |
674 | /* Make sure SIGCHLD is blocked. */ | |
675 | if (!sigismember (&blocked_mask, SIGCHLD)) | |
676 | sigaddset (&blocked_mask, SIGCHLD); | |
677 | ||
21987b9c | 678 | gdb_sigmask (SIG_BLOCK, &blocked_mask, prev_mask); |
7feb7d06 PA |
679 | } |
680 | ||
681 | /* Restore child signals mask, previously returned by | |
682 | block_child_signals. */ | |
683 | ||
684 | static void | |
685 | restore_child_signals_mask (sigset_t *prev_mask) | |
686 | { | |
21987b9c | 687 | gdb_sigmask (SIG_SETMASK, prev_mask, NULL); |
7feb7d06 | 688 | } |
2455069d UW |
689 | |
690 | /* Mask of signals to pass directly to the inferior. */ | |
691 | static sigset_t pass_mask; | |
692 | ||
693 | /* Update signals to pass to the inferior. */ | |
f6ac5f3d | 694 | void |
adc6a863 PA |
695 | linux_nat_target::pass_signals |
696 | (gdb::array_view<const unsigned char> pass_signals) | |
2455069d UW |
697 | { |
698 | int signo; | |
699 | ||
700 | sigemptyset (&pass_mask); | |
701 | ||
702 | for (signo = 1; signo < NSIG; signo++) | |
703 | { | |
2ea28649 | 704 | int target_signo = gdb_signal_from_host (signo); |
adc6a863 | 705 | if (target_signo < pass_signals.size () && pass_signals[target_signo]) |
dda83cd7 | 706 | sigaddset (&pass_mask, signo); |
2455069d UW |
707 | } |
708 | } | |
709 | ||
d6b0e80f AC |
710 | \f |
711 | ||
712 | /* Prototypes for local functions. */ | |
d3a70e03 TT |
713 | static int stop_wait_callback (struct lwp_info *lp); |
714 | static int resume_stopped_resumed_lwps (struct lwp_info *lp, const ptid_t wait_ptid); | |
ced2dffb | 715 | static int check_ptrace_stopped_lwp_gone (struct lwp_info *lp); |
710151dd | 716 | |
d6b0e80f | 717 | \f |
d6b0e80f | 718 | |
7b50312a PA |
719 | /* Destroy and free LP. */ |
720 | ||
676362df | 721 | lwp_info::~lwp_info () |
7b50312a | 722 | { |
466eecee | 723 | /* Let the arch specific bits release arch_lwp_info. */ |
676362df | 724 | linux_target->low_delete_thread (this->arch_private); |
7b50312a PA |
725 | } |
726 | ||
774113b0 | 727 | /* Traversal function for purge_lwp_list. */ |
d90e17a7 | 728 | |
774113b0 PA |
729 | static int |
730 | lwp_lwpid_htab_remove_pid (void **slot, void *info) | |
d90e17a7 | 731 | { |
774113b0 PA |
732 | struct lwp_info *lp = (struct lwp_info *) *slot; |
733 | int pid = *(int *) info; | |
d90e17a7 | 734 | |
e99b03dc | 735 | if (lp->ptid.pid () == pid) |
d90e17a7 | 736 | { |
774113b0 PA |
737 | htab_clear_slot (lwp_lwpid_htab, slot); |
738 | lwp_list_remove (lp); | |
676362df | 739 | delete lp; |
774113b0 | 740 | } |
d90e17a7 | 741 | |
774113b0 PA |
742 | return 1; |
743 | } | |
d90e17a7 | 744 | |
774113b0 PA |
745 | /* Remove all LWPs belong to PID from the lwp list. */ |
746 | ||
747 | static void | |
748 | purge_lwp_list (int pid) | |
749 | { | |
750 | htab_traverse_noresize (lwp_lwpid_htab, lwp_lwpid_htab_remove_pid, &pid); | |
d90e17a7 PA |
751 | } |
752 | ||
26cb8b7c PA |
753 | /* Add the LWP specified by PTID to the list. PTID is the first LWP |
754 | in the process. Return a pointer to the structure describing the | |
755 | new LWP. | |
756 | ||
757 | This differs from add_lwp in that we don't let the arch specific | |
758 | bits know about this new thread. Current clients of this callback | |
759 | take the opportunity to install watchpoints in the new thread, and | |
760 | we shouldn't do that for the first thread. If we're spawning a | |
761 | child ("run"), the thread executes the shell wrapper first, and we | |
762 | shouldn't touch it until it execs the program we want to debug. | |
763 | For "attach", it'd be okay to call the callback, but it's not | |
764 | necessary, because watchpoints can't yet have been inserted into | |
765 | the inferior. */ | |
d6b0e80f AC |
766 | |
767 | static struct lwp_info * | |
26cb8b7c | 768 | add_initial_lwp (ptid_t ptid) |
d6b0e80f | 769 | { |
15a9e13e | 770 | gdb_assert (ptid.lwp_p ()); |
d6b0e80f | 771 | |
b0f6c8d2 | 772 | lwp_info *lp = new lwp_info (ptid); |
d6b0e80f | 773 | |
d6b0e80f | 774 | |
774113b0 PA |
775 | /* Add to sorted-by-reverse-creation-order list. */ |
776 | lwp_list_add (lp); | |
777 | ||
778 | /* Add to keyed-by-pid htab. */ | |
779 | lwp_lwpid_htab_add_lwp (lp); | |
d6b0e80f | 780 | |
26cb8b7c PA |
781 | return lp; |
782 | } | |
783 | ||
784 | /* Add the LWP specified by PID to the list. Return a pointer to the | |
785 | structure describing the new LWP. The LWP should already be | |
786 | stopped. */ | |
787 | ||
788 | static struct lwp_info * | |
789 | add_lwp (ptid_t ptid) | |
790 | { | |
791 | struct lwp_info *lp; | |
792 | ||
793 | lp = add_initial_lwp (ptid); | |
794 | ||
6e012a6c PA |
795 | /* Let the arch specific bits know about this new thread. Current |
796 | clients of this callback take the opportunity to install | |
26cb8b7c PA |
797 | watchpoints in the new thread. We don't do this for the first |
798 | thread though. See add_initial_lwp. */ | |
135340af | 799 | linux_target->low_new_thread (lp); |
9f0bdab8 | 800 | |
d6b0e80f AC |
801 | return lp; |
802 | } | |
803 | ||
804 | /* Remove the LWP specified by PID from the list. */ | |
805 | ||
806 | static void | |
807 | delete_lwp (ptid_t ptid) | |
808 | { | |
b0f6c8d2 | 809 | lwp_info dummy (ptid); |
d6b0e80f | 810 | |
b0f6c8d2 | 811 | void **slot = htab_find_slot (lwp_lwpid_htab, &dummy, NO_INSERT); |
774113b0 PA |
812 | if (slot == NULL) |
813 | return; | |
d6b0e80f | 814 | |
b0f6c8d2 | 815 | lwp_info *lp = *(struct lwp_info **) slot; |
774113b0 | 816 | gdb_assert (lp != NULL); |
d6b0e80f | 817 | |
774113b0 | 818 | htab_clear_slot (lwp_lwpid_htab, slot); |
d6b0e80f | 819 | |
774113b0 PA |
820 | /* Remove from sorted-by-creation-order list. */ |
821 | lwp_list_remove (lp); | |
d6b0e80f | 822 | |
774113b0 | 823 | /* Release. */ |
676362df | 824 | delete lp; |
d6b0e80f AC |
825 | } |
826 | ||
827 | /* Return a pointer to the structure describing the LWP corresponding | |
828 | to PID. If no corresponding LWP could be found, return NULL. */ | |
829 | ||
830 | static struct lwp_info * | |
831 | find_lwp_pid (ptid_t ptid) | |
832 | { | |
d6b0e80f AC |
833 | int lwp; |
834 | ||
15a9e13e | 835 | if (ptid.lwp_p ()) |
e38504b3 | 836 | lwp = ptid.lwp (); |
d6b0e80f | 837 | else |
e99b03dc | 838 | lwp = ptid.pid (); |
d6b0e80f | 839 | |
b0f6c8d2 SM |
840 | lwp_info dummy (ptid_t (0, lwp)); |
841 | return (struct lwp_info *) htab_find (lwp_lwpid_htab, &dummy); | |
d6b0e80f AC |
842 | } |
843 | ||
6d4ee8c6 | 844 | /* See nat/linux-nat.h. */ |
d6b0e80f AC |
845 | |
846 | struct lwp_info * | |
d90e17a7 | 847 | iterate_over_lwps (ptid_t filter, |
d3a70e03 | 848 | gdb::function_view<iterate_over_lwps_ftype> callback) |
d6b0e80f | 849 | { |
901b9821 | 850 | for (lwp_info *lp : all_lwps_safe ()) |
d6b0e80f | 851 | { |
26a57c92 | 852 | if (lp->ptid.matches (filter)) |
d90e17a7 | 853 | { |
d3a70e03 | 854 | if (callback (lp) != 0) |
d90e17a7 PA |
855 | return lp; |
856 | } | |
d6b0e80f AC |
857 | } |
858 | ||
859 | return NULL; | |
860 | } | |
861 | ||
2277426b PA |
862 | /* Update our internal state when changing from one checkpoint to |
863 | another indicated by NEW_PTID. We can only switch single-threaded | |
864 | applications, so we only create one new LWP, and the previous list | |
865 | is discarded. */ | |
f973ed9c DJ |
866 | |
867 | void | |
868 | linux_nat_switch_fork (ptid_t new_ptid) | |
869 | { | |
870 | struct lwp_info *lp; | |
871 | ||
e99b03dc | 872 | purge_lwp_list (inferior_ptid.pid ()); |
2277426b | 873 | |
f973ed9c DJ |
874 | lp = add_lwp (new_ptid); |
875 | lp->stopped = 1; | |
e26af52f | 876 | |
2277426b PA |
877 | /* This changes the thread's ptid while preserving the gdb thread |
878 | num. Also changes the inferior pid, while preserving the | |
879 | inferior num. */ | |
5b6d1e4f | 880 | thread_change_ptid (linux_target, inferior_ptid, new_ptid); |
2277426b PA |
881 | |
882 | /* We've just told GDB core that the thread changed target id, but, | |
883 | in fact, it really is a different thread, with different register | |
884 | contents. */ | |
885 | registers_changed (); | |
e26af52f DJ |
886 | } |
887 | ||
e26af52f DJ |
888 | /* Handle the exit of a single thread LP. */ |
889 | ||
890 | static void | |
891 | exit_lwp (struct lwp_info *lp) | |
892 | { | |
5b6d1e4f | 893 | struct thread_info *th = find_thread_ptid (linux_target, lp->ptid); |
063bfe2e VP |
894 | |
895 | if (th) | |
e26af52f | 896 | { |
17faa917 | 897 | if (print_thread_events) |
6cb06a8c TT |
898 | gdb_printf (_("[%s exited]\n"), |
899 | target_pid_to_str (lp->ptid).c_str ()); | |
17faa917 | 900 | |
00431a78 | 901 | delete_thread (th); |
e26af52f DJ |
902 | } |
903 | ||
904 | delete_lwp (lp->ptid); | |
905 | } | |
906 | ||
a0ef4274 DJ |
907 | /* Wait for the LWP specified by LP, which we have just attached to. |
908 | Returns a wait status for that LWP, to cache. */ | |
909 | ||
910 | static int | |
22827c51 | 911 | linux_nat_post_attach_wait (ptid_t ptid, int *signalled) |
a0ef4274 | 912 | { |
e38504b3 | 913 | pid_t new_pid, pid = ptid.lwp (); |
a0ef4274 DJ |
914 | int status; |
915 | ||
644cebc9 | 916 | if (linux_proc_pid_is_stopped (pid)) |
a0ef4274 | 917 | { |
9327494e | 918 | linux_nat_debug_printf ("Attaching to a stopped process"); |
a0ef4274 DJ |
919 | |
920 | /* The process is definitely stopped. It is in a job control | |
921 | stop, unless the kernel predates the TASK_STOPPED / | |
922 | TASK_TRACED distinction, in which case it might be in a | |
923 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
924 | can kill it, signal it, et cetera. | |
925 | ||
dda83cd7 | 926 | First make sure there is a pending SIGSTOP. Since we are |
a0ef4274 DJ |
927 | already attached, the process can not transition from stopped |
928 | to running without a PTRACE_CONT; so we know this signal will | |
929 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
930 | probably already in the queue (unless this kernel is old | |
931 | enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP | |
932 | is not an RT signal, it can only be queued once. */ | |
933 | kill_lwp (pid, SIGSTOP); | |
934 | ||
935 | /* Finally, resume the stopped process. This will deliver the SIGSTOP | |
936 | (or a higher priority signal, just like normal PTRACE_ATTACH). */ | |
937 | ptrace (PTRACE_CONT, pid, 0, 0); | |
938 | } | |
939 | ||
940 | /* Make sure the initial process is stopped. The user-level threads | |
941 | layer might want to poke around in the inferior, and that won't | |
942 | work if things haven't stabilized yet. */ | |
4a6ed09b | 943 | new_pid = my_waitpid (pid, &status, __WALL); |
dacc9cb2 PP |
944 | gdb_assert (pid == new_pid); |
945 | ||
946 | if (!WIFSTOPPED (status)) | |
947 | { | |
948 | /* The pid we tried to attach has apparently just exited. */ | |
9327494e | 949 | linux_nat_debug_printf ("Failed to stop %d: %s", pid, |
8d06918f | 950 | status_to_str (status).c_str ()); |
dacc9cb2 PP |
951 | return status; |
952 | } | |
a0ef4274 DJ |
953 | |
954 | if (WSTOPSIG (status) != SIGSTOP) | |
955 | { | |
956 | *signalled = 1; | |
9327494e | 957 | linux_nat_debug_printf ("Received %s after attaching", |
8d06918f | 958 | status_to_str (status).c_str ()); |
a0ef4274 DJ |
959 | } |
960 | ||
961 | return status; | |
962 | } | |
963 | ||
f6ac5f3d PA |
964 | void |
965 | linux_nat_target::create_inferior (const char *exec_file, | |
966 | const std::string &allargs, | |
967 | char **env, int from_tty) | |
b84876c2 | 968 | { |
41272101 TT |
969 | maybe_disable_address_space_randomization restore_personality |
970 | (disable_randomization); | |
b84876c2 PA |
971 | |
972 | /* The fork_child mechanism is synchronous and calls target_wait, so | |
973 | we have to mask the async mode. */ | |
974 | ||
2455069d | 975 | /* Make sure we report all signals during startup. */ |
adc6a863 | 976 | pass_signals ({}); |
2455069d | 977 | |
f6ac5f3d | 978 | inf_ptrace_target::create_inferior (exec_file, allargs, env, from_tty); |
8a89ddbd PA |
979 | |
980 | open_proc_mem_file (inferior_ptid); | |
b84876c2 PA |
981 | } |
982 | ||
8784d563 PA |
983 | /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not |
984 | already attached. Returns true if a new LWP is found, false | |
985 | otherwise. */ | |
986 | ||
987 | static int | |
988 | attach_proc_task_lwp_callback (ptid_t ptid) | |
989 | { | |
990 | struct lwp_info *lp; | |
991 | ||
992 | /* Ignore LWPs we're already attached to. */ | |
993 | lp = find_lwp_pid (ptid); | |
994 | if (lp == NULL) | |
995 | { | |
e38504b3 | 996 | int lwpid = ptid.lwp (); |
8784d563 PA |
997 | |
998 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) | |
999 | { | |
1000 | int err = errno; | |
1001 | ||
1002 | /* Be quiet if we simply raced with the thread exiting. | |
1003 | EPERM is returned if the thread's task still exists, and | |
1004 | is marked as exited or zombie, as well as other | |
1005 | conditions, so in that case, confirm the status in | |
1006 | /proc/PID/status. */ | |
1007 | if (err == ESRCH | |
1008 | || (err == EPERM && linux_proc_pid_is_gone (lwpid))) | |
1009 | { | |
9327494e SM |
1010 | linux_nat_debug_printf |
1011 | ("Cannot attach to lwp %d: thread is gone (%d: %s)", | |
1012 | lwpid, err, safe_strerror (err)); | |
1013 | ||
8784d563 PA |
1014 | } |
1015 | else | |
1016 | { | |
4d9b86e1 | 1017 | std::string reason |
50fa3001 | 1018 | = linux_ptrace_attach_fail_reason_string (ptid, err); |
4d9b86e1 | 1019 | |
f71f0b0d | 1020 | warning (_("Cannot attach to lwp %d: %s"), |
4d9b86e1 | 1021 | lwpid, reason.c_str ()); |
8784d563 PA |
1022 | } |
1023 | } | |
1024 | else | |
1025 | { | |
9327494e | 1026 | linux_nat_debug_printf ("PTRACE_ATTACH %s, 0, 0 (OK)", |
e53c95d4 | 1027 | ptid.to_string ().c_str ()); |
8784d563 PA |
1028 | |
1029 | lp = add_lwp (ptid); | |
8784d563 PA |
1030 | |
1031 | /* The next time we wait for this LWP we'll see a SIGSTOP as | |
1032 | PTRACE_ATTACH brings it to a halt. */ | |
1033 | lp->signalled = 1; | |
1034 | ||
1035 | /* We need to wait for a stop before being able to make the | |
1036 | next ptrace call on this LWP. */ | |
1037 | lp->must_set_ptrace_flags = 1; | |
026a9174 PA |
1038 | |
1039 | /* So that wait collects the SIGSTOP. */ | |
1040 | lp->resumed = 1; | |
1041 | ||
1042 | /* Also add the LWP to gdb's thread list, in case a | |
1043 | matching libthread_db is not found (or the process uses | |
1044 | raw clone). */ | |
5b6d1e4f | 1045 | add_thread (linux_target, lp->ptid); |
719546c4 SM |
1046 | set_running (linux_target, lp->ptid, true); |
1047 | set_executing (linux_target, lp->ptid, true); | |
8784d563 PA |
1048 | } |
1049 | ||
1050 | return 1; | |
1051 | } | |
1052 | return 0; | |
1053 | } | |
1054 | ||
f6ac5f3d PA |
1055 | void |
1056 | linux_nat_target::attach (const char *args, int from_tty) | |
d6b0e80f AC |
1057 | { |
1058 | struct lwp_info *lp; | |
d6b0e80f | 1059 | int status; |
af990527 | 1060 | ptid_t ptid; |
d6b0e80f | 1061 | |
2455069d | 1062 | /* Make sure we report all signals during attach. */ |
adc6a863 | 1063 | pass_signals ({}); |
2455069d | 1064 | |
a70b8144 | 1065 | try |
87b0bb13 | 1066 | { |
f6ac5f3d | 1067 | inf_ptrace_target::attach (args, from_tty); |
87b0bb13 | 1068 | } |
230d2906 | 1069 | catch (const gdb_exception_error &ex) |
87b0bb13 JK |
1070 | { |
1071 | pid_t pid = parse_pid_to_attach (args); | |
50fa3001 | 1072 | std::string reason = linux_ptrace_attach_fail_reason (pid); |
87b0bb13 | 1073 | |
4d9b86e1 | 1074 | if (!reason.empty ()) |
3d6e9d23 TT |
1075 | throw_error (ex.error, "warning: %s\n%s", reason.c_str (), |
1076 | ex.what ()); | |
7ae1a6a6 | 1077 | else |
3d6e9d23 | 1078 | throw_error (ex.error, "%s", ex.what ()); |
87b0bb13 | 1079 | } |
d6b0e80f | 1080 | |
af990527 PA |
1081 | /* The ptrace base target adds the main thread with (pid,0,0) |
1082 | format. Decorate it with lwp info. */ | |
e99b03dc | 1083 | ptid = ptid_t (inferior_ptid.pid (), |
184ea2f7 | 1084 | inferior_ptid.pid ()); |
5b6d1e4f | 1085 | thread_change_ptid (linux_target, inferior_ptid, ptid); |
af990527 | 1086 | |
9f0bdab8 | 1087 | /* Add the initial process as the first LWP to the list. */ |
26cb8b7c | 1088 | lp = add_initial_lwp (ptid); |
a0ef4274 | 1089 | |
22827c51 | 1090 | status = linux_nat_post_attach_wait (lp->ptid, &lp->signalled); |
dacc9cb2 PP |
1091 | if (!WIFSTOPPED (status)) |
1092 | { | |
1093 | if (WIFEXITED (status)) | |
1094 | { | |
1095 | int exit_code = WEXITSTATUS (status); | |
1096 | ||
223ffa71 | 1097 | target_terminal::ours (); |
bc1e6c81 | 1098 | target_mourn_inferior (inferior_ptid); |
dacc9cb2 PP |
1099 | if (exit_code == 0) |
1100 | error (_("Unable to attach: program exited normally.")); | |
1101 | else | |
1102 | error (_("Unable to attach: program exited with code %d."), | |
1103 | exit_code); | |
1104 | } | |
1105 | else if (WIFSIGNALED (status)) | |
1106 | { | |
2ea28649 | 1107 | enum gdb_signal signo; |
dacc9cb2 | 1108 | |
223ffa71 | 1109 | target_terminal::ours (); |
bc1e6c81 | 1110 | target_mourn_inferior (inferior_ptid); |
dacc9cb2 | 1111 | |
2ea28649 | 1112 | signo = gdb_signal_from_host (WTERMSIG (status)); |
dacc9cb2 PP |
1113 | error (_("Unable to attach: program terminated with signal " |
1114 | "%s, %s."), | |
2ea28649 PA |
1115 | gdb_signal_to_name (signo), |
1116 | gdb_signal_to_string (signo)); | |
dacc9cb2 PP |
1117 | } |
1118 | ||
f34652de | 1119 | internal_error (_("unexpected status %d for PID %ld"), |
e38504b3 | 1120 | status, (long) ptid.lwp ()); |
dacc9cb2 PP |
1121 | } |
1122 | ||
a0ef4274 | 1123 | lp->stopped = 1; |
9f0bdab8 | 1124 | |
8a89ddbd PA |
1125 | open_proc_mem_file (lp->ptid); |
1126 | ||
a0ef4274 | 1127 | /* Save the wait status to report later. */ |
d6b0e80f | 1128 | lp->resumed = 1; |
9327494e | 1129 | linux_nat_debug_printf ("waitpid %ld, saving status %s", |
8d06918f SM |
1130 | (long) lp->ptid.pid (), |
1131 | status_to_str (status).c_str ()); | |
710151dd | 1132 | |
7feb7d06 PA |
1133 | lp->status = status; |
1134 | ||
8784d563 PA |
1135 | /* We must attach to every LWP. If /proc is mounted, use that to |
1136 | find them now. The inferior may be using raw clone instead of | |
1137 | using pthreads. But even if it is using pthreads, thread_db | |
1138 | walks structures in the inferior's address space to find the list | |
1139 | of threads/LWPs, and those structures may well be corrupted. | |
1140 | Note that once thread_db is loaded, we'll still use it to list | |
1141 | threads and associate pthread info with each LWP. */ | |
e99b03dc | 1142 | linux_proc_attach_tgid_threads (lp->ptid.pid (), |
8784d563 | 1143 | attach_proc_task_lwp_callback); |
d6b0e80f AC |
1144 | } |
1145 | ||
4a3ee32a SM |
1146 | /* Ptrace-detach the thread with pid PID. */ |
1147 | ||
1148 | static void | |
1149 | detach_one_pid (int pid, int signo) | |
1150 | { | |
1151 | if (ptrace (PTRACE_DETACH, pid, 0, signo) < 0) | |
1152 | { | |
1153 | int save_errno = errno; | |
1154 | ||
1155 | /* We know the thread exists, so ESRCH must mean the lwp is | |
1156 | zombie. This can happen if one of the already-detached | |
1157 | threads exits the whole thread group. In that case we're | |
1158 | still attached, and must reap the lwp. */ | |
1159 | if (save_errno == ESRCH) | |
1160 | { | |
1161 | int ret, status; | |
1162 | ||
1163 | ret = my_waitpid (pid, &status, __WALL); | |
1164 | if (ret == -1) | |
1165 | { | |
1166 | warning (_("Couldn't reap LWP %d while detaching: %s"), | |
1167 | pid, safe_strerror (errno)); | |
1168 | } | |
1169 | else if (!WIFEXITED (status) && !WIFSIGNALED (status)) | |
1170 | { | |
1171 | warning (_("Reaping LWP %d while detaching " | |
1172 | "returned unexpected status 0x%x"), | |
1173 | pid, status); | |
1174 | } | |
1175 | } | |
1176 | else | |
1177 | error (_("Can't detach %d: %s"), | |
1178 | pid, safe_strerror (save_errno)); | |
1179 | } | |
1180 | else | |
1181 | linux_nat_debug_printf ("PTRACE_DETACH (%d, %s, 0) (OK)", | |
1182 | pid, strsignal (signo)); | |
1183 | } | |
1184 | ||
ced2dffb PA |
1185 | /* Get pending signal of THREAD as a host signal number, for detaching |
1186 | purposes. This is the signal the thread last stopped for, which we | |
1187 | need to deliver to the thread when detaching, otherwise, it'd be | |
1188 | suppressed/lost. */ | |
1189 | ||
a0ef4274 | 1190 | static int |
ced2dffb | 1191 | get_detach_signal (struct lwp_info *lp) |
a0ef4274 | 1192 | { |
a493e3e2 | 1193 | enum gdb_signal signo = GDB_SIGNAL_0; |
ca2163eb PA |
1194 | |
1195 | /* If we paused threads momentarily, we may have stored pending | |
1196 | events in lp->status or lp->waitstatus (see stop_wait_callback), | |
1197 | and GDB core hasn't seen any signal for those threads. | |
1198 | Otherwise, the last signal reported to the core is found in the | |
1199 | thread object's stop_signal. | |
1200 | ||
1201 | There's a corner case that isn't handled here at present. Only | |
1202 | if the thread stopped with a TARGET_WAITKIND_STOPPED does | |
1203 | stop_signal make sense as a real signal to pass to the inferior. | |
1204 | Some catchpoint related events, like | |
1205 | TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set | |
a493e3e2 | 1206 | to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But, |
ca2163eb PA |
1207 | those traps are debug API (ptrace in our case) related and |
1208 | induced; the inferior wouldn't see them if it wasn't being | |
1209 | traced. Hence, we should never pass them to the inferior, even | |
1210 | when set to pass state. Since this corner case isn't handled by | |
1211 | infrun.c when proceeding with a signal, for consistency, neither | |
1212 | do we handle it here (or elsewhere in the file we check for | |
1213 | signal pass state). Normally SIGTRAP isn't set to pass state, so | |
1214 | this is really a corner case. */ | |
1215 | ||
183be222 | 1216 | if (lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE) |
a493e3e2 | 1217 | signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */ |
ca2163eb | 1218 | else if (lp->status) |
2ea28649 | 1219 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
00431a78 | 1220 | else |
ca2163eb | 1221 | { |
5b6d1e4f | 1222 | struct thread_info *tp = find_thread_ptid (linux_target, lp->ptid); |
e0881a8e | 1223 | |
611841bb | 1224 | if (target_is_non_stop_p () && !tp->executing ()) |
ca2163eb | 1225 | { |
1edb66d8 | 1226 | if (tp->has_pending_waitstatus ()) |
df5ad102 SM |
1227 | { |
1228 | /* If the thread has a pending event, and it was stopped with a | |
1229 | signal, use that signal to resume it. If it has a pending | |
1230 | event of another kind, it was not stopped with a signal, so | |
1231 | resume it without a signal. */ | |
1232 | if (tp->pending_waitstatus ().kind () == TARGET_WAITKIND_STOPPED) | |
1233 | signo = tp->pending_waitstatus ().sig (); | |
1234 | else | |
1235 | signo = GDB_SIGNAL_0; | |
1236 | } | |
00431a78 | 1237 | else |
1edb66d8 | 1238 | signo = tp->stop_signal (); |
00431a78 PA |
1239 | } |
1240 | else if (!target_is_non_stop_p ()) | |
1241 | { | |
00431a78 | 1242 | ptid_t last_ptid; |
5b6d1e4f | 1243 | process_stratum_target *last_target; |
00431a78 | 1244 | |
5b6d1e4f | 1245 | get_last_target_status (&last_target, &last_ptid, nullptr); |
e0881a8e | 1246 | |
5b6d1e4f PA |
1247 | if (last_target == linux_target |
1248 | && lp->ptid.lwp () == last_ptid.lwp ()) | |
1edb66d8 | 1249 | signo = tp->stop_signal (); |
4c28f408 | 1250 | } |
ca2163eb | 1251 | } |
4c28f408 | 1252 | |
a493e3e2 | 1253 | if (signo == GDB_SIGNAL_0) |
ca2163eb | 1254 | { |
9327494e | 1255 | linux_nat_debug_printf ("lwp %s has no pending signal", |
e53c95d4 | 1256 | lp->ptid.to_string ().c_str ()); |
ca2163eb PA |
1257 | } |
1258 | else if (!signal_pass_state (signo)) | |
1259 | { | |
9327494e SM |
1260 | linux_nat_debug_printf |
1261 | ("lwp %s had signal %s but it is in no pass state", | |
e53c95d4 | 1262 | lp->ptid.to_string ().c_str (), gdb_signal_to_string (signo)); |
a0ef4274 | 1263 | } |
a0ef4274 | 1264 | else |
4c28f408 | 1265 | { |
9327494e | 1266 | linux_nat_debug_printf ("lwp %s has pending signal %s", |
e53c95d4 | 1267 | lp->ptid.to_string ().c_str (), |
9327494e | 1268 | gdb_signal_to_string (signo)); |
ced2dffb PA |
1269 | |
1270 | return gdb_signal_to_host (signo); | |
4c28f408 | 1271 | } |
a0ef4274 DJ |
1272 | |
1273 | return 0; | |
1274 | } | |
1275 | ||
ced2dffb PA |
1276 | /* Detach from LP. If SIGNO_P is non-NULL, then it points to the |
1277 | signal number that should be passed to the LWP when detaching. | |
1278 | Otherwise pass any pending signal the LWP may have, if any. */ | |
1279 | ||
1280 | static void | |
1281 | detach_one_lwp (struct lwp_info *lp, int *signo_p) | |
d6b0e80f | 1282 | { |
e38504b3 | 1283 | int lwpid = lp->ptid.lwp (); |
ced2dffb PA |
1284 | int signo; |
1285 | ||
d6b0e80f AC |
1286 | gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status)); |
1287 | ||
df5ad102 SM |
1288 | /* If the lwp/thread we are about to detach has a pending fork event, |
1289 | there is a process GDB is attached to that the core of GDB doesn't know | |
1290 | about. Detach from it. */ | |
1291 | ||
1292 | /* Check in lwp_info::status. */ | |
1293 | if (WIFSTOPPED (lp->status) && linux_is_extended_waitstatus (lp->status)) | |
1294 | { | |
1295 | int event = linux_ptrace_get_extended_event (lp->status); | |
1296 | ||
1297 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) | |
1298 | { | |
1299 | unsigned long child_pid; | |
1300 | int ret = ptrace (PTRACE_GETEVENTMSG, lp->ptid.lwp (), 0, &child_pid); | |
1301 | if (ret == 0) | |
1302 | detach_one_pid (child_pid, 0); | |
1303 | else | |
1304 | perror_warning_with_name (_("Failed to detach fork child")); | |
1305 | } | |
1306 | } | |
1307 | ||
1308 | /* Check in lwp_info::waitstatus. */ | |
1309 | if (lp->waitstatus.kind () == TARGET_WAITKIND_VFORKED | |
1310 | || lp->waitstatus.kind () == TARGET_WAITKIND_FORKED) | |
1311 | detach_one_pid (lp->waitstatus.child_ptid ().pid (), 0); | |
1312 | ||
1313 | ||
1314 | /* Check in thread_info::pending_waitstatus. */ | |
1315 | thread_info *tp = find_thread_ptid (linux_target, lp->ptid); | |
1316 | if (tp->has_pending_waitstatus ()) | |
1317 | { | |
1318 | const target_waitstatus &ws = tp->pending_waitstatus (); | |
1319 | ||
1320 | if (ws.kind () == TARGET_WAITKIND_VFORKED | |
1321 | || ws.kind () == TARGET_WAITKIND_FORKED) | |
1322 | detach_one_pid (ws.child_ptid ().pid (), 0); | |
1323 | } | |
1324 | ||
1325 | /* Check in thread_info::pending_follow. */ | |
1326 | if (tp->pending_follow.kind () == TARGET_WAITKIND_VFORKED | |
1327 | || tp->pending_follow.kind () == TARGET_WAITKIND_FORKED) | |
1328 | detach_one_pid (tp->pending_follow.child_ptid ().pid (), 0); | |
1329 | ||
9327494e SM |
1330 | if (lp->status != 0) |
1331 | linux_nat_debug_printf ("Pending %s for %s on detach.", | |
1332 | strsignal (WSTOPSIG (lp->status)), | |
e53c95d4 | 1333 | lp->ptid.to_string ().c_str ()); |
d6b0e80f | 1334 | |
a0ef4274 DJ |
1335 | /* If there is a pending SIGSTOP, get rid of it. */ |
1336 | if (lp->signalled) | |
d6b0e80f | 1337 | { |
9327494e | 1338 | linux_nat_debug_printf ("Sending SIGCONT to %s", |
e53c95d4 | 1339 | lp->ptid.to_string ().c_str ()); |
d6b0e80f | 1340 | |
ced2dffb | 1341 | kill_lwp (lwpid, SIGCONT); |
d6b0e80f | 1342 | lp->signalled = 0; |
d6b0e80f AC |
1343 | } |
1344 | ||
ced2dffb | 1345 | if (signo_p == NULL) |
d6b0e80f | 1346 | { |
a0ef4274 | 1347 | /* Pass on any pending signal for this LWP. */ |
ced2dffb PA |
1348 | signo = get_detach_signal (lp); |
1349 | } | |
1350 | else | |
1351 | signo = *signo_p; | |
a0ef4274 | 1352 | |
ced2dffb PA |
1353 | /* Preparing to resume may try to write registers, and fail if the |
1354 | lwp is zombie. If that happens, ignore the error. We'll handle | |
1355 | it below, when detach fails with ESRCH. */ | |
a70b8144 | 1356 | try |
ced2dffb | 1357 | { |
135340af | 1358 | linux_target->low_prepare_to_resume (lp); |
ced2dffb | 1359 | } |
230d2906 | 1360 | catch (const gdb_exception_error &ex) |
ced2dffb PA |
1361 | { |
1362 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 1363 | throw; |
ced2dffb | 1364 | } |
d6b0e80f | 1365 | |
4a3ee32a | 1366 | detach_one_pid (lwpid, signo); |
ced2dffb PA |
1367 | |
1368 | delete_lwp (lp->ptid); | |
1369 | } | |
d6b0e80f | 1370 | |
ced2dffb | 1371 | static int |
d3a70e03 | 1372 | detach_callback (struct lwp_info *lp) |
ced2dffb PA |
1373 | { |
1374 | /* We don't actually detach from the thread group leader just yet. | |
1375 | If the thread group exits, we must reap the zombie clone lwps | |
1376 | before we're able to reap the leader. */ | |
e38504b3 | 1377 | if (lp->ptid.lwp () != lp->ptid.pid ()) |
ced2dffb | 1378 | detach_one_lwp (lp, NULL); |
d6b0e80f AC |
1379 | return 0; |
1380 | } | |
1381 | ||
f6ac5f3d PA |
1382 | void |
1383 | linux_nat_target::detach (inferior *inf, int from_tty) | |
d6b0e80f | 1384 | { |
d90e17a7 | 1385 | struct lwp_info *main_lwp; |
bc09b0c1 | 1386 | int pid = inf->pid; |
a0ef4274 | 1387 | |
ae5e0686 MK |
1388 | /* Don't unregister from the event loop, as there may be other |
1389 | inferiors running. */ | |
b84876c2 | 1390 | |
4c28f408 | 1391 | /* Stop all threads before detaching. ptrace requires that the |
30baf67b | 1392 | thread is stopped to successfully detach. */ |
d3a70e03 | 1393 | iterate_over_lwps (ptid_t (pid), stop_callback); |
4c28f408 PA |
1394 | /* ... and wait until all of them have reported back that |
1395 | they're no longer running. */ | |
d3a70e03 | 1396 | iterate_over_lwps (ptid_t (pid), stop_wait_callback); |
4c28f408 | 1397 | |
e87f0fe8 PA |
1398 | /* We can now safely remove breakpoints. We don't this in earlier |
1399 | in common code because this target doesn't currently support | |
1400 | writing memory while the inferior is running. */ | |
1401 | remove_breakpoints_inf (current_inferior ()); | |
1402 | ||
d3a70e03 | 1403 | iterate_over_lwps (ptid_t (pid), detach_callback); |
d6b0e80f AC |
1404 | |
1405 | /* Only the initial process should be left right now. */ | |
bc09b0c1 | 1406 | gdb_assert (num_lwps (pid) == 1); |
d90e17a7 | 1407 | |
f2907e49 | 1408 | main_lwp = find_lwp_pid (ptid_t (pid)); |
d6b0e80f | 1409 | |
7a7d3353 PA |
1410 | if (forks_exist_p ()) |
1411 | { | |
1412 | /* Multi-fork case. The current inferior_ptid is being detached | |
1413 | from, but there are other viable forks to debug. Detach from | |
1414 | the current fork, and context-switch to the first | |
1415 | available. */ | |
6bd6f3b6 | 1416 | linux_fork_detach (from_tty); |
7a7d3353 PA |
1417 | } |
1418 | else | |
ced2dffb | 1419 | { |
ced2dffb PA |
1420 | target_announce_detach (from_tty); |
1421 | ||
6bd6f3b6 SM |
1422 | /* Pass on any pending signal for the last LWP. */ |
1423 | int signo = get_detach_signal (main_lwp); | |
ced2dffb PA |
1424 | |
1425 | detach_one_lwp (main_lwp, &signo); | |
1426 | ||
f6ac5f3d | 1427 | detach_success (inf); |
ced2dffb | 1428 | } |
05c06f31 | 1429 | |
8a89ddbd | 1430 | close_proc_mem_file (pid); |
d6b0e80f AC |
1431 | } |
1432 | ||
8a99810d PA |
1433 | /* Resume execution of the inferior process. If STEP is nonzero, |
1434 | single-step it. If SIGNAL is nonzero, give it that signal. */ | |
1435 | ||
1436 | static void | |
23f238d3 PA |
1437 | linux_resume_one_lwp_throw (struct lwp_info *lp, int step, |
1438 | enum gdb_signal signo) | |
8a99810d | 1439 | { |
8a99810d | 1440 | lp->step = step; |
9c02b525 PA |
1441 | |
1442 | /* stop_pc doubles as the PC the LWP had when it was last resumed. | |
1443 | We only presently need that if the LWP is stepped though (to | |
1444 | handle the case of stepping a breakpoint instruction). */ | |
1445 | if (step) | |
1446 | { | |
5b6d1e4f | 1447 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
9c02b525 PA |
1448 | |
1449 | lp->stop_pc = regcache_read_pc (regcache); | |
1450 | } | |
1451 | else | |
1452 | lp->stop_pc = 0; | |
1453 | ||
135340af | 1454 | linux_target->low_prepare_to_resume (lp); |
f6ac5f3d | 1455 | linux_target->low_resume (lp->ptid, step, signo); |
23f238d3 PA |
1456 | |
1457 | /* Successfully resumed. Clear state that no longer makes sense, | |
1458 | and mark the LWP as running. Must not do this before resuming | |
1459 | otherwise if that fails other code will be confused. E.g., we'd | |
1460 | later try to stop the LWP and hang forever waiting for a stop | |
1461 | status. Note that we must not throw after this is cleared, | |
1462 | otherwise handle_zombie_lwp_error would get confused. */ | |
8a99810d | 1463 | lp->stopped = 0; |
1ad3de98 | 1464 | lp->core = -1; |
23f238d3 | 1465 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; |
5b6d1e4f | 1466 | registers_changed_ptid (linux_target, lp->ptid); |
8a99810d PA |
1467 | } |
1468 | ||
23f238d3 PA |
1469 | /* Called when we try to resume a stopped LWP and that errors out. If |
1470 | the LWP is no longer in ptrace-stopped state (meaning it's zombie, | |
1471 | or about to become), discard the error, clear any pending status | |
1472 | the LWP may have, and return true (we'll collect the exit status | |
1473 | soon enough). Otherwise, return false. */ | |
1474 | ||
1475 | static int | |
1476 | check_ptrace_stopped_lwp_gone (struct lwp_info *lp) | |
1477 | { | |
1478 | /* If we get an error after resuming the LWP successfully, we'd | |
1479 | confuse !T state for the LWP being gone. */ | |
1480 | gdb_assert (lp->stopped); | |
1481 | ||
1482 | /* We can't just check whether the LWP is in 'Z (Zombie)' state, | |
1483 | because even if ptrace failed with ESRCH, the tracee may be "not | |
1484 | yet fully dead", but already refusing ptrace requests. In that | |
1485 | case the tracee has 'R (Running)' state for a little bit | |
1486 | (observed in Linux 3.18). See also the note on ESRCH in the | |
1487 | ptrace(2) man page. Instead, check whether the LWP has any state | |
1488 | other than ptrace-stopped. */ | |
1489 | ||
1490 | /* Don't assume anything if /proc/PID/status can't be read. */ | |
e38504b3 | 1491 | if (linux_proc_pid_is_trace_stopped_nowarn (lp->ptid.lwp ()) == 0) |
23f238d3 PA |
1492 | { |
1493 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; | |
1494 | lp->status = 0; | |
183be222 | 1495 | lp->waitstatus.set_ignore (); |
23f238d3 PA |
1496 | return 1; |
1497 | } | |
1498 | return 0; | |
1499 | } | |
1500 | ||
1501 | /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP | |
1502 | disappears while we try to resume it. */ | |
1503 | ||
1504 | static void | |
1505 | linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) | |
1506 | { | |
a70b8144 | 1507 | try |
23f238d3 PA |
1508 | { |
1509 | linux_resume_one_lwp_throw (lp, step, signo); | |
1510 | } | |
230d2906 | 1511 | catch (const gdb_exception_error &ex) |
23f238d3 PA |
1512 | { |
1513 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 1514 | throw; |
23f238d3 | 1515 | } |
23f238d3 PA |
1516 | } |
1517 | ||
d6b0e80f AC |
1518 | /* Resume LP. */ |
1519 | ||
25289eb2 | 1520 | static void |
e5ef252a | 1521 | resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) |
d6b0e80f | 1522 | { |
25289eb2 | 1523 | if (lp->stopped) |
6c95b8df | 1524 | { |
5b6d1e4f | 1525 | struct inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
25289eb2 PA |
1526 | |
1527 | if (inf->vfork_child != NULL) | |
1528 | { | |
9327494e | 1529 | linux_nat_debug_printf ("Not resuming %s (vfork parent)", |
e53c95d4 | 1530 | lp->ptid.to_string ().c_str ()); |
25289eb2 | 1531 | } |
8a99810d | 1532 | else if (!lwp_status_pending_p (lp)) |
25289eb2 | 1533 | { |
9327494e | 1534 | linux_nat_debug_printf ("Resuming sibling %s, %s, %s", |
e53c95d4 | 1535 | lp->ptid.to_string ().c_str (), |
9327494e SM |
1536 | (signo != GDB_SIGNAL_0 |
1537 | ? strsignal (gdb_signal_to_host (signo)) | |
1538 | : "0"), | |
1539 | step ? "step" : "resume"); | |
25289eb2 | 1540 | |
8a99810d | 1541 | linux_resume_one_lwp (lp, step, signo); |
25289eb2 PA |
1542 | } |
1543 | else | |
1544 | { | |
9327494e | 1545 | linux_nat_debug_printf ("Not resuming sibling %s (has pending)", |
e53c95d4 | 1546 | lp->ptid.to_string ().c_str ()); |
25289eb2 | 1547 | } |
6c95b8df | 1548 | } |
25289eb2 | 1549 | else |
9327494e | 1550 | linux_nat_debug_printf ("Not resuming sibling %s (not stopped)", |
e53c95d4 | 1551 | lp->ptid.to_string ().c_str ()); |
25289eb2 | 1552 | } |
d6b0e80f | 1553 | |
8817a6f2 PA |
1554 | /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing. |
1555 | Resume LWP with the last stop signal, if it is in pass state. */ | |
e5ef252a | 1556 | |
25289eb2 | 1557 | static int |
d3a70e03 | 1558 | linux_nat_resume_callback (struct lwp_info *lp, struct lwp_info *except) |
25289eb2 | 1559 | { |
e5ef252a PA |
1560 | enum gdb_signal signo = GDB_SIGNAL_0; |
1561 | ||
8817a6f2 PA |
1562 | if (lp == except) |
1563 | return 0; | |
1564 | ||
e5ef252a PA |
1565 | if (lp->stopped) |
1566 | { | |
1567 | struct thread_info *thread; | |
1568 | ||
5b6d1e4f | 1569 | thread = find_thread_ptid (linux_target, lp->ptid); |
e5ef252a PA |
1570 | if (thread != NULL) |
1571 | { | |
1edb66d8 SM |
1572 | signo = thread->stop_signal (); |
1573 | thread->set_stop_signal (GDB_SIGNAL_0); | |
e5ef252a PA |
1574 | } |
1575 | } | |
1576 | ||
1577 | resume_lwp (lp, 0, signo); | |
d6b0e80f AC |
1578 | return 0; |
1579 | } | |
1580 | ||
1581 | static int | |
d3a70e03 | 1582 | resume_clear_callback (struct lwp_info *lp) |
d6b0e80f AC |
1583 | { |
1584 | lp->resumed = 0; | |
25289eb2 | 1585 | lp->last_resume_kind = resume_stop; |
d6b0e80f AC |
1586 | return 0; |
1587 | } | |
1588 | ||
1589 | static int | |
d3a70e03 | 1590 | resume_set_callback (struct lwp_info *lp) |
d6b0e80f AC |
1591 | { |
1592 | lp->resumed = 1; | |
25289eb2 | 1593 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1594 | return 0; |
1595 | } | |
1596 | ||
f6ac5f3d | 1597 | void |
d51926f0 | 1598 | linux_nat_target::resume (ptid_t scope_ptid, int step, enum gdb_signal signo) |
d6b0e80f AC |
1599 | { |
1600 | struct lwp_info *lp; | |
d6b0e80f | 1601 | |
9327494e SM |
1602 | linux_nat_debug_printf ("Preparing to %s %s, %s, inferior_ptid %s", |
1603 | step ? "step" : "resume", | |
d51926f0 | 1604 | scope_ptid.to_string ().c_str (), |
9327494e SM |
1605 | (signo != GDB_SIGNAL_0 |
1606 | ? strsignal (gdb_signal_to_host (signo)) : "0"), | |
e53c95d4 | 1607 | inferior_ptid.to_string ().c_str ()); |
76f50ad1 | 1608 | |
7da6a5b9 LM |
1609 | /* Mark the lwps we're resuming as resumed and update their |
1610 | last_resume_kind to resume_continue. */ | |
d51926f0 | 1611 | iterate_over_lwps (scope_ptid, resume_set_callback); |
d6b0e80f | 1612 | |
d51926f0 | 1613 | lp = find_lwp_pid (inferior_ptid); |
9f0bdab8 | 1614 | gdb_assert (lp != NULL); |
d6b0e80f | 1615 | |
9f0bdab8 | 1616 | /* Remember if we're stepping. */ |
25289eb2 | 1617 | lp->last_resume_kind = step ? resume_step : resume_continue; |
d6b0e80f | 1618 | |
9f0bdab8 DJ |
1619 | /* If we have a pending wait status for this thread, there is no |
1620 | point in resuming the process. But first make sure that | |
1621 | linux_nat_wait won't preemptively handle the event - we | |
1622 | should never take this short-circuit if we are going to | |
1623 | leave LP running, since we have skipped resuming all the | |
1624 | other threads. This bit of code needs to be synchronized | |
1625 | with linux_nat_wait. */ | |
76f50ad1 | 1626 | |
9f0bdab8 DJ |
1627 | if (lp->status && WIFSTOPPED (lp->status)) |
1628 | { | |
2455069d UW |
1629 | if (!lp->step |
1630 | && WSTOPSIG (lp->status) | |
1631 | && sigismember (&pass_mask, WSTOPSIG (lp->status))) | |
d6b0e80f | 1632 | { |
9327494e SM |
1633 | linux_nat_debug_printf |
1634 | ("Not short circuiting for ignored status 0x%x", lp->status); | |
9f0bdab8 | 1635 | |
d6b0e80f AC |
1636 | /* FIXME: What should we do if we are supposed to continue |
1637 | this thread with a signal? */ | |
a493e3e2 | 1638 | gdb_assert (signo == GDB_SIGNAL_0); |
2ea28649 | 1639 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
9f0bdab8 DJ |
1640 | lp->status = 0; |
1641 | } | |
1642 | } | |
76f50ad1 | 1643 | |
8a99810d | 1644 | if (lwp_status_pending_p (lp)) |
9f0bdab8 DJ |
1645 | { |
1646 | /* FIXME: What should we do if we are supposed to continue | |
1647 | this thread with a signal? */ | |
a493e3e2 | 1648 | gdb_assert (signo == GDB_SIGNAL_0); |
76f50ad1 | 1649 | |
9327494e SM |
1650 | linux_nat_debug_printf ("Short circuiting for status 0x%x", |
1651 | lp->status); | |
d6b0e80f | 1652 | |
7feb7d06 PA |
1653 | if (target_can_async_p ()) |
1654 | { | |
4a570176 | 1655 | target_async (true); |
7feb7d06 PA |
1656 | /* Tell the event loop we have something to process. */ |
1657 | async_file_mark (); | |
1658 | } | |
9f0bdab8 | 1659 | return; |
d6b0e80f AC |
1660 | } |
1661 | ||
d51926f0 PA |
1662 | /* No use iterating unless we're resuming other threads. */ |
1663 | if (scope_ptid != lp->ptid) | |
1664 | iterate_over_lwps (scope_ptid, [=] (struct lwp_info *info) | |
1665 | { | |
1666 | return linux_nat_resume_callback (info, lp); | |
1667 | }); | |
d90e17a7 | 1668 | |
9327494e SM |
1669 | linux_nat_debug_printf ("%s %s, %s (resume event thread)", |
1670 | step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 1671 | lp->ptid.to_string ().c_str (), |
9327494e SM |
1672 | (signo != GDB_SIGNAL_0 |
1673 | ? strsignal (gdb_signal_to_host (signo)) : "0")); | |
b84876c2 | 1674 | |
2bf6fb9d | 1675 | linux_resume_one_lwp (lp, step, signo); |
d6b0e80f AC |
1676 | } |
1677 | ||
c5f62d5f | 1678 | /* Send a signal to an LWP. */ |
d6b0e80f AC |
1679 | |
1680 | static int | |
1681 | kill_lwp (int lwpid, int signo) | |
1682 | { | |
4a6ed09b | 1683 | int ret; |
d6b0e80f | 1684 | |
4a6ed09b PA |
1685 | errno = 0; |
1686 | ret = syscall (__NR_tkill, lwpid, signo); | |
1687 | if (errno == ENOSYS) | |
1688 | { | |
1689 | /* If tkill fails, then we are not using nptl threads, a | |
1690 | configuration we no longer support. */ | |
1691 | perror_with_name (("tkill")); | |
1692 | } | |
1693 | return ret; | |
d6b0e80f AC |
1694 | } |
1695 | ||
ca2163eb PA |
1696 | /* Handle a GNU/Linux syscall trap wait response. If we see a syscall |
1697 | event, check if the core is interested in it: if not, ignore the | |
1698 | event, and keep waiting; otherwise, we need to toggle the LWP's | |
1699 | syscall entry/exit status, since the ptrace event itself doesn't | |
1700 | indicate it, and report the trap to higher layers. */ | |
1701 | ||
1702 | static int | |
1703 | linux_handle_syscall_trap (struct lwp_info *lp, int stopping) | |
1704 | { | |
1705 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
1706 | struct gdbarch *gdbarch = target_thread_architecture (lp->ptid); | |
5b6d1e4f | 1707 | thread_info *thread = find_thread_ptid (linux_target, lp->ptid); |
00431a78 | 1708 | int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, thread); |
ca2163eb PA |
1709 | |
1710 | if (stopping) | |
1711 | { | |
1712 | /* If we're stopping threads, there's a SIGSTOP pending, which | |
1713 | makes it so that the LWP reports an immediate syscall return, | |
1714 | followed by the SIGSTOP. Skip seeing that "return" using | |
1715 | PTRACE_CONT directly, and let stop_wait_callback collect the | |
1716 | SIGSTOP. Later when the thread is resumed, a new syscall | |
1717 | entry event. If we didn't do this (and returned 0), we'd | |
1718 | leave a syscall entry pending, and our caller, by using | |
1719 | PTRACE_CONT to collect the SIGSTOP, skips the syscall return | |
1720 | itself. Later, when the user re-resumes this LWP, we'd see | |
1721 | another syscall entry event and we'd mistake it for a return. | |
1722 | ||
1723 | If stop_wait_callback didn't force the SIGSTOP out of the LWP | |
1724 | (leaving immediately with LWP->signalled set, without issuing | |
1725 | a PTRACE_CONT), it would still be problematic to leave this | |
1726 | syscall enter pending, as later when the thread is resumed, | |
1727 | it would then see the same syscall exit mentioned above, | |
1728 | followed by the delayed SIGSTOP, while the syscall didn't | |
1729 | actually get to execute. It seems it would be even more | |
1730 | confusing to the user. */ | |
1731 | ||
9327494e SM |
1732 | linux_nat_debug_printf |
1733 | ("ignoring syscall %d for LWP %ld (stopping threads), resuming with " | |
1734 | "PTRACE_CONT for SIGSTOP", syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1735 | |
1736 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
e38504b3 | 1737 | ptrace (PTRACE_CONT, lp->ptid.lwp (), 0, 0); |
8817a6f2 | 1738 | lp->stopped = 0; |
ca2163eb PA |
1739 | return 1; |
1740 | } | |
1741 | ||
bfd09d20 JS |
1742 | /* Always update the entry/return state, even if this particular |
1743 | syscall isn't interesting to the core now. In async mode, | |
1744 | the user could install a new catchpoint for this syscall | |
1745 | between syscall enter/return, and we'll need to know to | |
1746 | report a syscall return if that happens. */ | |
1747 | lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1748 | ? TARGET_WAITKIND_SYSCALL_RETURN | |
1749 | : TARGET_WAITKIND_SYSCALL_ENTRY); | |
1750 | ||
ca2163eb PA |
1751 | if (catch_syscall_enabled ()) |
1752 | { | |
ca2163eb PA |
1753 | if (catching_syscall_number (syscall_number)) |
1754 | { | |
1755 | /* Alright, an event to report. */ | |
183be222 SM |
1756 | if (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY) |
1757 | ourstatus->set_syscall_entry (syscall_number); | |
1758 | else if (lp->syscall_state == TARGET_WAITKIND_SYSCALL_RETURN) | |
1759 | ourstatus->set_syscall_return (syscall_number); | |
1760 | else | |
1761 | gdb_assert_not_reached ("unexpected syscall state"); | |
ca2163eb | 1762 | |
9327494e SM |
1763 | linux_nat_debug_printf |
1764 | ("stopping for %s of syscall %d for LWP %ld", | |
1765 | (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1766 | ? "entry" : "return"), syscall_number, lp->ptid.lwp ()); | |
1767 | ||
ca2163eb PA |
1768 | return 0; |
1769 | } | |
1770 | ||
9327494e SM |
1771 | linux_nat_debug_printf |
1772 | ("ignoring %s of syscall %d for LWP %ld", | |
1773 | (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1774 | ? "entry" : "return"), syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1775 | } |
1776 | else | |
1777 | { | |
1778 | /* If we had been syscall tracing, and hence used PT_SYSCALL | |
1779 | before on this LWP, it could happen that the user removes all | |
1780 | syscall catchpoints before we get to process this event. | |
1781 | There are two noteworthy issues here: | |
1782 | ||
1783 | - When stopped at a syscall entry event, resuming with | |
1784 | PT_STEP still resumes executing the syscall and reports a | |
1785 | syscall return. | |
1786 | ||
1787 | - Only PT_SYSCALL catches syscall enters. If we last | |
1788 | single-stepped this thread, then this event can't be a | |
1789 | syscall enter. If we last single-stepped this thread, this | |
1790 | has to be a syscall exit. | |
1791 | ||
1792 | The points above mean that the next resume, be it PT_STEP or | |
1793 | PT_CONTINUE, can not trigger a syscall trace event. */ | |
9327494e SM |
1794 | linux_nat_debug_printf |
1795 | ("caught syscall event with no syscall catchpoints. %d for LWP %ld, " | |
1796 | "ignoring", syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1797 | lp->syscall_state = TARGET_WAITKIND_IGNORE; |
1798 | } | |
1799 | ||
1800 | /* The core isn't interested in this event. For efficiency, avoid | |
1801 | stopping all threads only to have the core resume them all again. | |
1802 | Since we're not stopping threads, if we're still syscall tracing | |
1803 | and not stepping, we can't use PTRACE_CONT here, as we'd miss any | |
1804 | subsequent syscall. Simply resume using the inf-ptrace layer, | |
1805 | which knows when to use PT_SYSCALL or PT_CONTINUE. */ | |
1806 | ||
8a99810d | 1807 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
ca2163eb PA |
1808 | return 1; |
1809 | } | |
1810 | ||
3d799a95 DJ |
1811 | /* Handle a GNU/Linux extended wait response. If we see a clone |
1812 | event, we need to add the new LWP to our list (and not report the | |
1813 | trap to higher layers). This function returns non-zero if the | |
1814 | event should be ignored and we should wait again. If STOPPING is | |
1815 | true, the new LWP remains stopped, otherwise it is continued. */ | |
d6b0e80f AC |
1816 | |
1817 | static int | |
4dd63d48 | 1818 | linux_handle_extended_wait (struct lwp_info *lp, int status) |
d6b0e80f | 1819 | { |
e38504b3 | 1820 | int pid = lp->ptid.lwp (); |
3d799a95 | 1821 | struct target_waitstatus *ourstatus = &lp->waitstatus; |
89a5711c | 1822 | int event = linux_ptrace_get_extended_event (status); |
d6b0e80f | 1823 | |
bfd09d20 JS |
1824 | /* All extended events we currently use are mid-syscall. Only |
1825 | PTRACE_EVENT_STOP is delivered more like a signal-stop, but | |
1826 | you have to be using PTRACE_SEIZE to get that. */ | |
1827 | lp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY; | |
1828 | ||
3d799a95 DJ |
1829 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
1830 | || event == PTRACE_EVENT_CLONE) | |
d6b0e80f | 1831 | { |
3d799a95 DJ |
1832 | unsigned long new_pid; |
1833 | int ret; | |
1834 | ||
1835 | ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); | |
6fc19103 | 1836 | |
3d799a95 DJ |
1837 | /* If we haven't already seen the new PID stop, wait for it now. */ |
1838 | if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
1839 | { | |
1840 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
1841 | hits the SIGSTOP, but we're already attached. */ | |
4a6ed09b | 1842 | ret = my_waitpid (new_pid, &status, __WALL); |
3d799a95 DJ |
1843 | if (ret == -1) |
1844 | perror_with_name (_("waiting for new child")); | |
1845 | else if (ret != new_pid) | |
f34652de | 1846 | internal_error (_("wait returned unexpected PID %d"), ret); |
3d799a95 | 1847 | else if (!WIFSTOPPED (status)) |
f34652de | 1848 | internal_error (_("wait returned unexpected status 0x%x"), status); |
3d799a95 DJ |
1849 | } |
1850 | ||
183be222 | 1851 | ptid_t child_ptid (new_pid, new_pid); |
3d799a95 | 1852 | |
26cb8b7c PA |
1853 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) |
1854 | { | |
8a89ddbd PA |
1855 | open_proc_mem_file (child_ptid); |
1856 | ||
26cb8b7c PA |
1857 | /* The arch-specific native code may need to know about new |
1858 | forks even if those end up never mapped to an | |
1859 | inferior. */ | |
135340af | 1860 | linux_target->low_new_fork (lp, new_pid); |
26cb8b7c | 1861 | } |
1310c1b0 PFC |
1862 | else if (event == PTRACE_EVENT_CLONE) |
1863 | { | |
1864 | linux_target->low_new_clone (lp, new_pid); | |
1865 | } | |
26cb8b7c | 1866 | |
2277426b | 1867 | if (event == PTRACE_EVENT_FORK |
e99b03dc | 1868 | && linux_fork_checkpointing_p (lp->ptid.pid ())) |
2277426b | 1869 | { |
2277426b PA |
1870 | /* Handle checkpointing by linux-fork.c here as a special |
1871 | case. We don't want the follow-fork-mode or 'catch fork' | |
1872 | to interfere with this. */ | |
1873 | ||
1874 | /* This won't actually modify the breakpoint list, but will | |
1875 | physically remove the breakpoints from the child. */ | |
184ea2f7 | 1876 | detach_breakpoints (ptid_t (new_pid, new_pid)); |
2277426b PA |
1877 | |
1878 | /* Retain child fork in ptrace (stopped) state. */ | |
14571dad MS |
1879 | if (!find_fork_pid (new_pid)) |
1880 | add_fork (new_pid); | |
2277426b PA |
1881 | |
1882 | /* Report as spurious, so that infrun doesn't want to follow | |
1883 | this fork. We're actually doing an infcall in | |
1884 | linux-fork.c. */ | |
183be222 | 1885 | ourstatus->set_spurious (); |
2277426b PA |
1886 | |
1887 | /* Report the stop to the core. */ | |
1888 | return 0; | |
1889 | } | |
1890 | ||
3d799a95 | 1891 | if (event == PTRACE_EVENT_FORK) |
183be222 | 1892 | ourstatus->set_forked (child_ptid); |
3d799a95 | 1893 | else if (event == PTRACE_EVENT_VFORK) |
183be222 | 1894 | ourstatus->set_vforked (child_ptid); |
4dd63d48 | 1895 | else if (event == PTRACE_EVENT_CLONE) |
3d799a95 | 1896 | { |
78768c4a JK |
1897 | struct lwp_info *new_lp; |
1898 | ||
183be222 | 1899 | ourstatus->set_ignore (); |
78768c4a | 1900 | |
9327494e SM |
1901 | linux_nat_debug_printf |
1902 | ("Got clone event from LWP %d, new child is LWP %ld", pid, new_pid); | |
3c4d7e12 | 1903 | |
184ea2f7 | 1904 | new_lp = add_lwp (ptid_t (lp->ptid.pid (), new_pid)); |
4c28f408 | 1905 | new_lp->stopped = 1; |
4dd63d48 | 1906 | new_lp->resumed = 1; |
d6b0e80f | 1907 | |
2db9a427 PA |
1908 | /* If the thread_db layer is active, let it record the user |
1909 | level thread id and status, and add the thread to GDB's | |
1910 | list. */ | |
1911 | if (!thread_db_notice_clone (lp->ptid, new_lp->ptid)) | |
3d799a95 | 1912 | { |
2db9a427 PA |
1913 | /* The process is not using thread_db. Add the LWP to |
1914 | GDB's list. */ | |
5b6d1e4f | 1915 | add_thread (linux_target, new_lp->ptid); |
2db9a427 | 1916 | } |
4c28f408 | 1917 | |
2ee52aa4 | 1918 | /* Even if we're stopping the thread for some reason |
4dd63d48 PA |
1919 | internal to this module, from the perspective of infrun |
1920 | and the user/frontend, this new thread is running until | |
1921 | it next reports a stop. */ | |
719546c4 SM |
1922 | set_running (linux_target, new_lp->ptid, true); |
1923 | set_executing (linux_target, new_lp->ptid, true); | |
4c28f408 | 1924 | |
4dd63d48 | 1925 | if (WSTOPSIG (status) != SIGSTOP) |
79395f92 | 1926 | { |
4dd63d48 PA |
1927 | /* This can happen if someone starts sending signals to |
1928 | the new thread before it gets a chance to run, which | |
1929 | have a lower number than SIGSTOP (e.g. SIGUSR1). | |
1930 | This is an unlikely case, and harder to handle for | |
1931 | fork / vfork than for clone, so we do not try - but | |
1932 | we handle it for clone events here. */ | |
1933 | ||
1934 | new_lp->signalled = 1; | |
1935 | ||
79395f92 PA |
1936 | /* We created NEW_LP so it cannot yet contain STATUS. */ |
1937 | gdb_assert (new_lp->status == 0); | |
1938 | ||
1939 | /* Save the wait status to report later. */ | |
9327494e SM |
1940 | linux_nat_debug_printf |
1941 | ("waitpid of new LWP %ld, saving status %s", | |
8d06918f | 1942 | (long) new_lp->ptid.lwp (), status_to_str (status).c_str ()); |
79395f92 PA |
1943 | new_lp->status = status; |
1944 | } | |
aa01bd36 PA |
1945 | else if (report_thread_events) |
1946 | { | |
183be222 | 1947 | new_lp->waitstatus.set_thread_created (); |
aa01bd36 PA |
1948 | new_lp->status = status; |
1949 | } | |
79395f92 | 1950 | |
3d799a95 DJ |
1951 | return 1; |
1952 | } | |
1953 | ||
1954 | return 0; | |
d6b0e80f AC |
1955 | } |
1956 | ||
3d799a95 DJ |
1957 | if (event == PTRACE_EVENT_EXEC) |
1958 | { | |
9327494e | 1959 | linux_nat_debug_printf ("Got exec event from LWP %ld", lp->ptid.lwp ()); |
a75724bc | 1960 | |
8a89ddbd PA |
1961 | /* Close the previous /proc/PID/mem file for this inferior, |
1962 | which was using the address space which is now gone. | |
1963 | Reading/writing from this file would return 0/EOF. */ | |
1964 | close_proc_mem_file (lp->ptid.pid ()); | |
1965 | ||
1966 | /* Open a new file for the new address space. */ | |
1967 | open_proc_mem_file (lp->ptid); | |
05c06f31 | 1968 | |
183be222 SM |
1969 | ourstatus->set_execd |
1970 | (make_unique_xstrdup (linux_proc_pid_to_exec_file (pid))); | |
3d799a95 | 1971 | |
8af756ef PA |
1972 | /* The thread that execed must have been resumed, but, when a |
1973 | thread execs, it changes its tid to the tgid, and the old | |
1974 | tgid thread might have not been resumed. */ | |
1975 | lp->resumed = 1; | |
6c95b8df PA |
1976 | return 0; |
1977 | } | |
1978 | ||
1979 | if (event == PTRACE_EVENT_VFORK_DONE) | |
1980 | { | |
9327494e | 1981 | linux_nat_debug_printf |
5a0c4a06 SM |
1982 | ("Got PTRACE_EVENT_VFORK_DONE from LWP %ld", |
1983 | lp->ptid.lwp ()); | |
1984 | ourstatus->set_vfork_done (); | |
1985 | return 0; | |
3d799a95 DJ |
1986 | } |
1987 | ||
f34652de | 1988 | internal_error (_("unknown ptrace event %d"), event); |
d6b0e80f AC |
1989 | } |
1990 | ||
9c3a5d93 PA |
1991 | /* Suspend waiting for a signal. We're mostly interested in |
1992 | SIGCHLD/SIGINT. */ | |
1993 | ||
1994 | static void | |
1995 | wait_for_signal () | |
1996 | { | |
9327494e | 1997 | linux_nat_debug_printf ("about to sigsuspend"); |
9c3a5d93 PA |
1998 | sigsuspend (&suspend_mask); |
1999 | ||
2000 | /* If the quit flag is set, it means that the user pressed Ctrl-C | |
2001 | and we're debugging a process that is running on a separate | |
2002 | terminal, so we must forward the Ctrl-C to the inferior. (If the | |
2003 | inferior is sharing GDB's terminal, then the Ctrl-C reaches the | |
2004 | inferior directly.) We must do this here because functions that | |
2005 | need to block waiting for a signal loop forever until there's an | |
2006 | event to report before returning back to the event loop. */ | |
2007 | if (!target_terminal::is_ours ()) | |
2008 | { | |
2009 | if (check_quit_flag ()) | |
2010 | target_pass_ctrlc (); | |
2011 | } | |
2012 | } | |
2013 | ||
d6b0e80f AC |
2014 | /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has |
2015 | exited. */ | |
2016 | ||
2017 | static int | |
2018 | wait_lwp (struct lwp_info *lp) | |
2019 | { | |
2020 | pid_t pid; | |
432b4d03 | 2021 | int status = 0; |
d6b0e80f | 2022 | int thread_dead = 0; |
432b4d03 | 2023 | sigset_t prev_mask; |
d6b0e80f AC |
2024 | |
2025 | gdb_assert (!lp->stopped); | |
2026 | gdb_assert (lp->status == 0); | |
2027 | ||
432b4d03 JK |
2028 | /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
2029 | block_child_signals (&prev_mask); | |
2030 | ||
2031 | for (;;) | |
d6b0e80f | 2032 | { |
e38504b3 | 2033 | pid = my_waitpid (lp->ptid.lwp (), &status, __WALL | WNOHANG); |
a9f4bb21 PA |
2034 | if (pid == -1 && errno == ECHILD) |
2035 | { | |
2036 | /* The thread has previously exited. We need to delete it | |
4a6ed09b PA |
2037 | now because if this was a non-leader thread execing, we |
2038 | won't get an exit event. See comments on exec events at | |
2039 | the top of the file. */ | |
a9f4bb21 | 2040 | thread_dead = 1; |
9327494e | 2041 | linux_nat_debug_printf ("%s vanished.", |
e53c95d4 | 2042 | lp->ptid.to_string ().c_str ()); |
a9f4bb21 | 2043 | } |
432b4d03 JK |
2044 | if (pid != 0) |
2045 | break; | |
2046 | ||
2047 | /* Bugs 10970, 12702. | |
2048 | Thread group leader may have exited in which case we'll lock up in | |
2049 | waitpid if there are other threads, even if they are all zombies too. | |
2050 | Basically, we're not supposed to use waitpid this way. | |
4a6ed09b PA |
2051 | tkill(pid,0) cannot be used here as it gets ESRCH for both |
2052 | for zombie and running processes. | |
432b4d03 JK |
2053 | |
2054 | As a workaround, check if we're waiting for the thread group leader and | |
2055 | if it's a zombie, and avoid calling waitpid if it is. | |
2056 | ||
2057 | This is racy, what if the tgl becomes a zombie right after we check? | |
2058 | Therefore always use WNOHANG with sigsuspend - it is equivalent to | |
5f572dec | 2059 | waiting waitpid but linux_proc_pid_is_zombie is safe this way. */ |
432b4d03 | 2060 | |
e38504b3 TT |
2061 | if (lp->ptid.pid () == lp->ptid.lwp () |
2062 | && linux_proc_pid_is_zombie (lp->ptid.lwp ())) | |
d6b0e80f | 2063 | { |
d6b0e80f | 2064 | thread_dead = 1; |
9327494e | 2065 | linux_nat_debug_printf ("Thread group leader %s vanished.", |
e53c95d4 | 2066 | lp->ptid.to_string ().c_str ()); |
432b4d03 | 2067 | break; |
d6b0e80f | 2068 | } |
432b4d03 JK |
2069 | |
2070 | /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers | |
2071 | get invoked despite our caller had them intentionally blocked by | |
2072 | block_child_signals. This is sensitive only to the loop of | |
2073 | linux_nat_wait_1 and there if we get called my_waitpid gets called | |
2074 | again before it gets to sigsuspend so we can safely let the handlers | |
2075 | get executed here. */ | |
9c3a5d93 | 2076 | wait_for_signal (); |
432b4d03 JK |
2077 | } |
2078 | ||
2079 | restore_child_signals_mask (&prev_mask); | |
2080 | ||
d6b0e80f AC |
2081 | if (!thread_dead) |
2082 | { | |
e38504b3 | 2083 | gdb_assert (pid == lp->ptid.lwp ()); |
d6b0e80f | 2084 | |
9327494e | 2085 | linux_nat_debug_printf ("waitpid %s received %s", |
e53c95d4 | 2086 | lp->ptid.to_string ().c_str (), |
8d06918f | 2087 | status_to_str (status).c_str ()); |
d6b0e80f | 2088 | |
a9f4bb21 PA |
2089 | /* Check if the thread has exited. */ |
2090 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
2091 | { | |
aa01bd36 | 2092 | if (report_thread_events |
e38504b3 | 2093 | || lp->ptid.pid () == lp->ptid.lwp ()) |
69dde7dc | 2094 | { |
9327494e | 2095 | linux_nat_debug_printf ("LWP %d exited.", lp->ptid.pid ()); |
69dde7dc | 2096 | |
aa01bd36 | 2097 | /* If this is the leader exiting, it means the whole |
69dde7dc PA |
2098 | process is gone. Store the status to report to the |
2099 | core. Store it in lp->waitstatus, because lp->status | |
2100 | would be ambiguous (W_EXITCODE(0,0) == 0). */ | |
7509b829 | 2101 | lp->waitstatus = host_status_to_waitstatus (status); |
69dde7dc PA |
2102 | return 0; |
2103 | } | |
2104 | ||
a9f4bb21 | 2105 | thread_dead = 1; |
9327494e | 2106 | linux_nat_debug_printf ("%s exited.", |
e53c95d4 | 2107 | lp->ptid.to_string ().c_str ()); |
a9f4bb21 | 2108 | } |
d6b0e80f AC |
2109 | } |
2110 | ||
2111 | if (thread_dead) | |
2112 | { | |
e26af52f | 2113 | exit_lwp (lp); |
d6b0e80f AC |
2114 | return 0; |
2115 | } | |
2116 | ||
2117 | gdb_assert (WIFSTOPPED (status)); | |
8817a6f2 | 2118 | lp->stopped = 1; |
d6b0e80f | 2119 | |
8784d563 PA |
2120 | if (lp->must_set_ptrace_flags) |
2121 | { | |
5b6d1e4f | 2122 | inferior *inf = find_inferior_pid (linux_target, lp->ptid.pid ()); |
de0d863e | 2123 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 2124 | |
e38504b3 | 2125 | linux_enable_event_reporting (lp->ptid.lwp (), options); |
8784d563 PA |
2126 | lp->must_set_ptrace_flags = 0; |
2127 | } | |
2128 | ||
ca2163eb PA |
2129 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2130 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2131 | { | |
2132 | /* No longer need the sysgood bit. The ptrace event ends up | |
2133 | recorded in lp->waitstatus if we care for it. We can carry | |
2134 | on handling the event like a regular SIGTRAP from here | |
2135 | on. */ | |
2136 | status = W_STOPCODE (SIGTRAP); | |
2137 | if (linux_handle_syscall_trap (lp, 1)) | |
2138 | return wait_lwp (lp); | |
2139 | } | |
bfd09d20 JS |
2140 | else |
2141 | { | |
2142 | /* Almost all other ptrace-stops are known to be outside of system | |
2143 | calls, with further exceptions in linux_handle_extended_wait. */ | |
2144 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2145 | } | |
ca2163eb | 2146 | |
d6b0e80f | 2147 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2148 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2149 | && linux_is_extended_waitstatus (status)) | |
d6b0e80f | 2150 | { |
9327494e | 2151 | linux_nat_debug_printf ("Handling extended status 0x%06x", status); |
4dd63d48 | 2152 | linux_handle_extended_wait (lp, status); |
20ba1ce6 | 2153 | return 0; |
d6b0e80f AC |
2154 | } |
2155 | ||
2156 | return status; | |
2157 | } | |
2158 | ||
2159 | /* Send a SIGSTOP to LP. */ | |
2160 | ||
2161 | static int | |
d3a70e03 | 2162 | stop_callback (struct lwp_info *lp) |
d6b0e80f AC |
2163 | { |
2164 | if (!lp->stopped && !lp->signalled) | |
2165 | { | |
2166 | int ret; | |
2167 | ||
9327494e | 2168 | linux_nat_debug_printf ("kill %s **<SIGSTOP>**", |
e53c95d4 | 2169 | lp->ptid.to_string ().c_str ()); |
9327494e | 2170 | |
d6b0e80f | 2171 | errno = 0; |
e38504b3 | 2172 | ret = kill_lwp (lp->ptid.lwp (), SIGSTOP); |
9327494e | 2173 | linux_nat_debug_printf ("lwp kill %d %s", ret, |
d6b0e80f | 2174 | errno ? safe_strerror (errno) : "ERRNO-OK"); |
d6b0e80f AC |
2175 | |
2176 | lp->signalled = 1; | |
2177 | gdb_assert (lp->status == 0); | |
2178 | } | |
2179 | ||
2180 | return 0; | |
2181 | } | |
2182 | ||
7b50312a PA |
2183 | /* Request a stop on LWP. */ |
2184 | ||
2185 | void | |
2186 | linux_stop_lwp (struct lwp_info *lwp) | |
2187 | { | |
d3a70e03 | 2188 | stop_callback (lwp); |
7b50312a PA |
2189 | } |
2190 | ||
2db9a427 PA |
2191 | /* See linux-nat.h */ |
2192 | ||
2193 | void | |
2194 | linux_stop_and_wait_all_lwps (void) | |
2195 | { | |
2196 | /* Stop all LWP's ... */ | |
d3a70e03 | 2197 | iterate_over_lwps (minus_one_ptid, stop_callback); |
2db9a427 PA |
2198 | |
2199 | /* ... and wait until all of them have reported back that | |
2200 | they're no longer running. */ | |
d3a70e03 | 2201 | iterate_over_lwps (minus_one_ptid, stop_wait_callback); |
2db9a427 PA |
2202 | } |
2203 | ||
2204 | /* See linux-nat.h */ | |
2205 | ||
2206 | void | |
2207 | linux_unstop_all_lwps (void) | |
2208 | { | |
2209 | iterate_over_lwps (minus_one_ptid, | |
d3a70e03 TT |
2210 | [] (struct lwp_info *info) |
2211 | { | |
2212 | return resume_stopped_resumed_lwps (info, minus_one_ptid); | |
2213 | }); | |
2db9a427 PA |
2214 | } |
2215 | ||
57380f4e | 2216 | /* Return non-zero if LWP PID has a pending SIGINT. */ |
d6b0e80f AC |
2217 | |
2218 | static int | |
57380f4e DJ |
2219 | linux_nat_has_pending_sigint (int pid) |
2220 | { | |
2221 | sigset_t pending, blocked, ignored; | |
57380f4e DJ |
2222 | |
2223 | linux_proc_pending_signals (pid, &pending, &blocked, &ignored); | |
2224 | ||
2225 | if (sigismember (&pending, SIGINT) | |
2226 | && !sigismember (&ignored, SIGINT)) | |
2227 | return 1; | |
2228 | ||
2229 | return 0; | |
2230 | } | |
2231 | ||
2232 | /* Set a flag in LP indicating that we should ignore its next SIGINT. */ | |
2233 | ||
2234 | static int | |
d3a70e03 | 2235 | set_ignore_sigint (struct lwp_info *lp) |
d6b0e80f | 2236 | { |
57380f4e DJ |
2237 | /* If a thread has a pending SIGINT, consume it; otherwise, set a |
2238 | flag to consume the next one. */ | |
2239 | if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) | |
2240 | && WSTOPSIG (lp->status) == SIGINT) | |
2241 | lp->status = 0; | |
2242 | else | |
2243 | lp->ignore_sigint = 1; | |
2244 | ||
2245 | return 0; | |
2246 | } | |
2247 | ||
2248 | /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. | |
2249 | This function is called after we know the LWP has stopped; if the LWP | |
2250 | stopped before the expected SIGINT was delivered, then it will never have | |
2251 | arrived. Also, if the signal was delivered to a shared queue and consumed | |
2252 | by a different thread, it will never be delivered to this LWP. */ | |
d6b0e80f | 2253 | |
57380f4e DJ |
2254 | static void |
2255 | maybe_clear_ignore_sigint (struct lwp_info *lp) | |
2256 | { | |
2257 | if (!lp->ignore_sigint) | |
2258 | return; | |
2259 | ||
e38504b3 | 2260 | if (!linux_nat_has_pending_sigint (lp->ptid.lwp ())) |
57380f4e | 2261 | { |
9327494e | 2262 | linux_nat_debug_printf ("Clearing bogus flag for %s", |
e53c95d4 | 2263 | lp->ptid.to_string ().c_str ()); |
57380f4e DJ |
2264 | lp->ignore_sigint = 0; |
2265 | } | |
2266 | } | |
2267 | ||
ebec9a0f PA |
2268 | /* Fetch the possible triggered data watchpoint info and store it in |
2269 | LP. | |
2270 | ||
2271 | On some archs, like x86, that use debug registers to set | |
2272 | watchpoints, it's possible that the way to know which watched | |
2273 | address trapped, is to check the register that is used to select | |
2274 | which address to watch. Problem is, between setting the watchpoint | |
2275 | and reading back which data address trapped, the user may change | |
2276 | the set of watchpoints, and, as a consequence, GDB changes the | |
2277 | debug registers in the inferior. To avoid reading back a stale | |
2278 | stopped-data-address when that happens, we cache in LP the fact | |
2279 | that a watchpoint trapped, and the corresponding data address, as | |
2280 | soon as we see LP stop with a SIGTRAP. If GDB changes the debug | |
2281 | registers meanwhile, we have the cached data we can rely on. */ | |
2282 | ||
9c02b525 PA |
2283 | static int |
2284 | check_stopped_by_watchpoint (struct lwp_info *lp) | |
ebec9a0f | 2285 | { |
2989a365 | 2286 | scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); |
ebec9a0f PA |
2287 | inferior_ptid = lp->ptid; |
2288 | ||
f6ac5f3d | 2289 | if (linux_target->low_stopped_by_watchpoint ()) |
ebec9a0f | 2290 | { |
15c66dd6 | 2291 | lp->stop_reason = TARGET_STOPPED_BY_WATCHPOINT; |
f6ac5f3d PA |
2292 | lp->stopped_data_address_p |
2293 | = linux_target->low_stopped_data_address (&lp->stopped_data_address); | |
ebec9a0f PA |
2294 | } |
2295 | ||
15c66dd6 | 2296 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
9c02b525 PA |
2297 | } |
2298 | ||
9c02b525 | 2299 | /* Returns true if the LWP had stopped for a watchpoint. */ |
ebec9a0f | 2300 | |
57810aa7 | 2301 | bool |
f6ac5f3d | 2302 | linux_nat_target::stopped_by_watchpoint () |
ebec9a0f PA |
2303 | { |
2304 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2305 | ||
2306 | gdb_assert (lp != NULL); | |
2307 | ||
15c66dd6 | 2308 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
ebec9a0f PA |
2309 | } |
2310 | ||
57810aa7 | 2311 | bool |
f6ac5f3d | 2312 | linux_nat_target::stopped_data_address (CORE_ADDR *addr_p) |
ebec9a0f PA |
2313 | { |
2314 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2315 | ||
2316 | gdb_assert (lp != NULL); | |
2317 | ||
2318 | *addr_p = lp->stopped_data_address; | |
2319 | ||
2320 | return lp->stopped_data_address_p; | |
2321 | } | |
2322 | ||
26ab7092 JK |
2323 | /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
2324 | ||
135340af PA |
2325 | bool |
2326 | linux_nat_target::low_status_is_event (int status) | |
26ab7092 JK |
2327 | { |
2328 | return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; | |
2329 | } | |
2330 | ||
57380f4e DJ |
2331 | /* Wait until LP is stopped. */ |
2332 | ||
2333 | static int | |
d3a70e03 | 2334 | stop_wait_callback (struct lwp_info *lp) |
57380f4e | 2335 | { |
5b6d1e4f | 2336 | inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
6c95b8df PA |
2337 | |
2338 | /* If this is a vfork parent, bail out, it is not going to report | |
2339 | any SIGSTOP until the vfork is done with. */ | |
2340 | if (inf->vfork_child != NULL) | |
2341 | return 0; | |
2342 | ||
d6b0e80f AC |
2343 | if (!lp->stopped) |
2344 | { | |
2345 | int status; | |
2346 | ||
2347 | status = wait_lwp (lp); | |
2348 | if (status == 0) | |
2349 | return 0; | |
2350 | ||
57380f4e DJ |
2351 | if (lp->ignore_sigint && WIFSTOPPED (status) |
2352 | && WSTOPSIG (status) == SIGINT) | |
d6b0e80f | 2353 | { |
57380f4e | 2354 | lp->ignore_sigint = 0; |
d6b0e80f AC |
2355 | |
2356 | errno = 0; | |
e38504b3 | 2357 | ptrace (PTRACE_CONT, lp->ptid.lwp (), 0, 0); |
8817a6f2 | 2358 | lp->stopped = 0; |
9327494e SM |
2359 | linux_nat_debug_printf |
2360 | ("PTRACE_CONT %s, 0, 0 (%s) (discarding SIGINT)", | |
e53c95d4 | 2361 | lp->ptid.to_string ().c_str (), |
9327494e | 2362 | errno ? safe_strerror (errno) : "OK"); |
d6b0e80f | 2363 | |
d3a70e03 | 2364 | return stop_wait_callback (lp); |
d6b0e80f AC |
2365 | } |
2366 | ||
57380f4e DJ |
2367 | maybe_clear_ignore_sigint (lp); |
2368 | ||
d6b0e80f AC |
2369 | if (WSTOPSIG (status) != SIGSTOP) |
2370 | { | |
e5ef252a | 2371 | /* The thread was stopped with a signal other than SIGSTOP. */ |
7feb7d06 | 2372 | |
9327494e | 2373 | linux_nat_debug_printf ("Pending event %s in %s", |
8d06918f | 2374 | status_to_str ((int) status).c_str (), |
e53c95d4 | 2375 | lp->ptid.to_string ().c_str ()); |
e5ef252a PA |
2376 | |
2377 | /* Save the sigtrap event. */ | |
2378 | lp->status = status; | |
e5ef252a | 2379 | gdb_assert (lp->signalled); |
e7ad2f14 | 2380 | save_stop_reason (lp); |
d6b0e80f AC |
2381 | } |
2382 | else | |
2383 | { | |
7010835a | 2384 | /* We caught the SIGSTOP that we intended to catch. */ |
e5ef252a | 2385 | |
9327494e | 2386 | linux_nat_debug_printf ("Expected SIGSTOP caught for %s.", |
e53c95d4 | 2387 | lp->ptid.to_string ().c_str ()); |
e5ef252a | 2388 | |
d6b0e80f | 2389 | lp->signalled = 0; |
7010835a AB |
2390 | |
2391 | /* If we are waiting for this stop so we can report the thread | |
2392 | stopped then we need to record this status. Otherwise, we can | |
2393 | now discard this stop event. */ | |
2394 | if (lp->last_resume_kind == resume_stop) | |
2395 | { | |
2396 | lp->status = status; | |
2397 | save_stop_reason (lp); | |
2398 | } | |
d6b0e80f AC |
2399 | } |
2400 | } | |
2401 | ||
2402 | return 0; | |
2403 | } | |
2404 | ||
9c02b525 PA |
2405 | /* Return non-zero if LP has a wait status pending. Discard the |
2406 | pending event and resume the LWP if the event that originally | |
2407 | caused the stop became uninteresting. */ | |
d6b0e80f AC |
2408 | |
2409 | static int | |
d3a70e03 | 2410 | status_callback (struct lwp_info *lp) |
d6b0e80f AC |
2411 | { |
2412 | /* Only report a pending wait status if we pretend that this has | |
2413 | indeed been resumed. */ | |
ca2163eb PA |
2414 | if (!lp->resumed) |
2415 | return 0; | |
2416 | ||
eb54c8bf PA |
2417 | if (!lwp_status_pending_p (lp)) |
2418 | return 0; | |
2419 | ||
15c66dd6 PA |
2420 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
2421 | || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) | |
9c02b525 | 2422 | { |
5b6d1e4f | 2423 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
9c02b525 PA |
2424 | CORE_ADDR pc; |
2425 | int discard = 0; | |
2426 | ||
9c02b525 PA |
2427 | pc = regcache_read_pc (regcache); |
2428 | ||
2429 | if (pc != lp->stop_pc) | |
2430 | { | |
9327494e | 2431 | linux_nat_debug_printf ("PC of %s changed. was=%s, now=%s", |
e53c95d4 | 2432 | lp->ptid.to_string ().c_str (), |
9327494e SM |
2433 | paddress (target_gdbarch (), lp->stop_pc), |
2434 | paddress (target_gdbarch (), pc)); | |
9c02b525 PA |
2435 | discard = 1; |
2436 | } | |
faf09f01 PA |
2437 | |
2438 | #if !USE_SIGTRAP_SIGINFO | |
a01bda52 | 2439 | else if (!breakpoint_inserted_here_p (regcache->aspace (), pc)) |
9c02b525 | 2440 | { |
9327494e | 2441 | linux_nat_debug_printf ("previous breakpoint of %s, at %s gone", |
e53c95d4 | 2442 | lp->ptid.to_string ().c_str (), |
9327494e | 2443 | paddress (target_gdbarch (), lp->stop_pc)); |
9c02b525 PA |
2444 | |
2445 | discard = 1; | |
2446 | } | |
faf09f01 | 2447 | #endif |
9c02b525 PA |
2448 | |
2449 | if (discard) | |
2450 | { | |
9327494e | 2451 | linux_nat_debug_printf ("pending event of %s cancelled.", |
e53c95d4 | 2452 | lp->ptid.to_string ().c_str ()); |
9c02b525 PA |
2453 | |
2454 | lp->status = 0; | |
2455 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); | |
2456 | return 0; | |
2457 | } | |
9c02b525 PA |
2458 | } |
2459 | ||
eb54c8bf | 2460 | return 1; |
d6b0e80f AC |
2461 | } |
2462 | ||
d6b0e80f AC |
2463 | /* Count the LWP's that have had events. */ |
2464 | ||
2465 | static int | |
d3a70e03 | 2466 | count_events_callback (struct lwp_info *lp, int *count) |
d6b0e80f | 2467 | { |
d6b0e80f AC |
2468 | gdb_assert (count != NULL); |
2469 | ||
9c02b525 PA |
2470 | /* Select only resumed LWPs that have an event pending. */ |
2471 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2472 | (*count)++; |
2473 | ||
2474 | return 0; | |
2475 | } | |
2476 | ||
2477 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
2478 | ||
2479 | static int | |
d3a70e03 | 2480 | select_singlestep_lwp_callback (struct lwp_info *lp) |
d6b0e80f | 2481 | { |
25289eb2 PA |
2482 | if (lp->last_resume_kind == resume_step |
2483 | && lp->status != 0) | |
d6b0e80f AC |
2484 | return 1; |
2485 | else | |
2486 | return 0; | |
2487 | } | |
2488 | ||
8a99810d PA |
2489 | /* Returns true if LP has a status pending. */ |
2490 | ||
2491 | static int | |
2492 | lwp_status_pending_p (struct lwp_info *lp) | |
2493 | { | |
2494 | /* We check for lp->waitstatus in addition to lp->status, because we | |
2495 | can have pending process exits recorded in lp->status and | |
2496 | W_EXITCODE(0,0) happens to be 0. */ | |
183be222 | 2497 | return lp->status != 0 || lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE; |
8a99810d PA |
2498 | } |
2499 | ||
b90fc188 | 2500 | /* Select the Nth LWP that has had an event. */ |
d6b0e80f AC |
2501 | |
2502 | static int | |
d3a70e03 | 2503 | select_event_lwp_callback (struct lwp_info *lp, int *selector) |
d6b0e80f | 2504 | { |
d6b0e80f AC |
2505 | gdb_assert (selector != NULL); |
2506 | ||
9c02b525 PA |
2507 | /* Select only resumed LWPs that have an event pending. */ |
2508 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2509 | if ((*selector)-- == 0) |
2510 | return 1; | |
2511 | ||
2512 | return 0; | |
2513 | } | |
2514 | ||
e7ad2f14 PA |
2515 | /* Called when the LWP stopped for a signal/trap. If it stopped for a |
2516 | trap check what caused it (breakpoint, watchpoint, trace, etc.), | |
2517 | and save the result in the LWP's stop_reason field. If it stopped | |
2518 | for a breakpoint, decrement the PC if necessary on the lwp's | |
2519 | architecture. */ | |
9c02b525 | 2520 | |
e7ad2f14 PA |
2521 | static void |
2522 | save_stop_reason (struct lwp_info *lp) | |
710151dd | 2523 | { |
e7ad2f14 PA |
2524 | struct regcache *regcache; |
2525 | struct gdbarch *gdbarch; | |
515630c5 | 2526 | CORE_ADDR pc; |
9c02b525 | 2527 | CORE_ADDR sw_bp_pc; |
faf09f01 PA |
2528 | #if USE_SIGTRAP_SIGINFO |
2529 | siginfo_t siginfo; | |
2530 | #endif | |
9c02b525 | 2531 | |
e7ad2f14 PA |
2532 | gdb_assert (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON); |
2533 | gdb_assert (lp->status != 0); | |
2534 | ||
135340af | 2535 | if (!linux_target->low_status_is_event (lp->status)) |
e7ad2f14 PA |
2536 | return; |
2537 | ||
a9deee17 PA |
2538 | inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
2539 | if (inf->starting_up) | |
2540 | return; | |
2541 | ||
5b6d1e4f | 2542 | regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 2543 | gdbarch = regcache->arch (); |
e7ad2f14 | 2544 | |
9c02b525 | 2545 | pc = regcache_read_pc (regcache); |
527a273a | 2546 | sw_bp_pc = pc - gdbarch_decr_pc_after_break (gdbarch); |
515630c5 | 2547 | |
faf09f01 PA |
2548 | #if USE_SIGTRAP_SIGINFO |
2549 | if (linux_nat_get_siginfo (lp->ptid, &siginfo)) | |
2550 | { | |
2551 | if (siginfo.si_signo == SIGTRAP) | |
2552 | { | |
e7ad2f14 PA |
2553 | if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code) |
2554 | && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) | |
faf09f01 | 2555 | { |
e7ad2f14 PA |
2556 | /* The si_code is ambiguous on this arch -- check debug |
2557 | registers. */ | |
2558 | if (!check_stopped_by_watchpoint (lp)) | |
2559 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2560 | } | |
2561 | else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)) | |
2562 | { | |
2563 | /* If we determine the LWP stopped for a SW breakpoint, | |
2564 | trust it. Particularly don't check watchpoint | |
7da6a5b9 | 2565 | registers, because, at least on s390, we'd find |
e7ad2f14 PA |
2566 | stopped-by-watchpoint as long as there's a watchpoint |
2567 | set. */ | |
faf09f01 | 2568 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
faf09f01 | 2569 | } |
e7ad2f14 | 2570 | else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) |
faf09f01 | 2571 | { |
e7ad2f14 PA |
2572 | /* This can indicate either a hardware breakpoint or |
2573 | hardware watchpoint. Check debug registers. */ | |
2574 | if (!check_stopped_by_watchpoint (lp)) | |
2575 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; | |
faf09f01 | 2576 | } |
2bf6fb9d PA |
2577 | else if (siginfo.si_code == TRAP_TRACE) |
2578 | { | |
9327494e | 2579 | linux_nat_debug_printf ("%s stopped by trace", |
e53c95d4 | 2580 | lp->ptid.to_string ().c_str ()); |
e7ad2f14 PA |
2581 | |
2582 | /* We may have single stepped an instruction that | |
2583 | triggered a watchpoint. In that case, on some | |
2584 | architectures (such as x86), instead of TRAP_HWBKPT, | |
2585 | si_code indicates TRAP_TRACE, and we need to check | |
2586 | the debug registers separately. */ | |
2587 | check_stopped_by_watchpoint (lp); | |
2bf6fb9d | 2588 | } |
faf09f01 PA |
2589 | } |
2590 | } | |
2591 | #else | |
9c02b525 | 2592 | if ((!lp->step || lp->stop_pc == sw_bp_pc) |
a01bda52 | 2593 | && software_breakpoint_inserted_here_p (regcache->aspace (), |
9c02b525 | 2594 | sw_bp_pc)) |
710151dd | 2595 | { |
9c02b525 PA |
2596 | /* The LWP was either continued, or stepped a software |
2597 | breakpoint instruction. */ | |
e7ad2f14 PA |
2598 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
2599 | } | |
2600 | ||
a01bda52 | 2601 | if (hardware_breakpoint_inserted_here_p (regcache->aspace (), pc)) |
e7ad2f14 PA |
2602 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; |
2603 | ||
2604 | if (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON) | |
2605 | check_stopped_by_watchpoint (lp); | |
2606 | #endif | |
2607 | ||
2608 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT) | |
2609 | { | |
9327494e | 2610 | linux_nat_debug_printf ("%s stopped by software breakpoint", |
e53c95d4 | 2611 | lp->ptid.to_string ().c_str ()); |
710151dd PA |
2612 | |
2613 | /* Back up the PC if necessary. */ | |
9c02b525 PA |
2614 | if (pc != sw_bp_pc) |
2615 | regcache_write_pc (regcache, sw_bp_pc); | |
515630c5 | 2616 | |
e7ad2f14 PA |
2617 | /* Update this so we record the correct stop PC below. */ |
2618 | pc = sw_bp_pc; | |
710151dd | 2619 | } |
e7ad2f14 | 2620 | else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) |
9c02b525 | 2621 | { |
9327494e | 2622 | linux_nat_debug_printf ("%s stopped by hardware breakpoint", |
e53c95d4 | 2623 | lp->ptid.to_string ().c_str ()); |
e7ad2f14 PA |
2624 | } |
2625 | else if (lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT) | |
2626 | { | |
9327494e | 2627 | linux_nat_debug_printf ("%s stopped by hardware watchpoint", |
e53c95d4 | 2628 | lp->ptid.to_string ().c_str ()); |
9c02b525 | 2629 | } |
d6b0e80f | 2630 | |
e7ad2f14 | 2631 | lp->stop_pc = pc; |
d6b0e80f AC |
2632 | } |
2633 | ||
faf09f01 PA |
2634 | |
2635 | /* Returns true if the LWP had stopped for a software breakpoint. */ | |
2636 | ||
57810aa7 | 2637 | bool |
f6ac5f3d | 2638 | linux_nat_target::stopped_by_sw_breakpoint () |
faf09f01 PA |
2639 | { |
2640 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2641 | ||
2642 | gdb_assert (lp != NULL); | |
2643 | ||
2644 | return lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2645 | } | |
2646 | ||
2647 | /* Implement the supports_stopped_by_sw_breakpoint method. */ | |
2648 | ||
57810aa7 | 2649 | bool |
f6ac5f3d | 2650 | linux_nat_target::supports_stopped_by_sw_breakpoint () |
faf09f01 PA |
2651 | { |
2652 | return USE_SIGTRAP_SIGINFO; | |
2653 | } | |
2654 | ||
2655 | /* Returns true if the LWP had stopped for a hardware | |
2656 | breakpoint/watchpoint. */ | |
2657 | ||
57810aa7 | 2658 | bool |
f6ac5f3d | 2659 | linux_nat_target::stopped_by_hw_breakpoint () |
faf09f01 PA |
2660 | { |
2661 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2662 | ||
2663 | gdb_assert (lp != NULL); | |
2664 | ||
2665 | return lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT; | |
2666 | } | |
2667 | ||
2668 | /* Implement the supports_stopped_by_hw_breakpoint method. */ | |
2669 | ||
57810aa7 | 2670 | bool |
f6ac5f3d | 2671 | linux_nat_target::supports_stopped_by_hw_breakpoint () |
faf09f01 PA |
2672 | { |
2673 | return USE_SIGTRAP_SIGINFO; | |
2674 | } | |
2675 | ||
d6b0e80f AC |
2676 | /* Select one LWP out of those that have events pending. */ |
2677 | ||
2678 | static void | |
d90e17a7 | 2679 | select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
d6b0e80f AC |
2680 | { |
2681 | int num_events = 0; | |
2682 | int random_selector; | |
9c02b525 | 2683 | struct lwp_info *event_lp = NULL; |
d6b0e80f | 2684 | |
ac264b3b | 2685 | /* Record the wait status for the original LWP. */ |
d6b0e80f AC |
2686 | (*orig_lp)->status = *status; |
2687 | ||
9c02b525 PA |
2688 | /* In all-stop, give preference to the LWP that is being |
2689 | single-stepped. There will be at most one, and it will be the | |
2690 | LWP that the core is most interested in. If we didn't do this, | |
2691 | then we'd have to handle pending step SIGTRAPs somehow in case | |
2692 | the core later continues the previously-stepped thread, as | |
2693 | otherwise we'd report the pending SIGTRAP then, and the core, not | |
2694 | having stepped the thread, wouldn't understand what the trap was | |
2695 | for, and therefore would report it to the user as a random | |
2696 | signal. */ | |
fbea99ea | 2697 | if (!target_is_non_stop_p ()) |
d6b0e80f | 2698 | { |
d3a70e03 | 2699 | event_lp = iterate_over_lwps (filter, select_singlestep_lwp_callback); |
9c02b525 PA |
2700 | if (event_lp != NULL) |
2701 | { | |
9327494e | 2702 | linux_nat_debug_printf ("Select single-step %s", |
e53c95d4 | 2703 | event_lp->ptid.to_string ().c_str ()); |
9c02b525 | 2704 | } |
d6b0e80f | 2705 | } |
9c02b525 PA |
2706 | |
2707 | if (event_lp == NULL) | |
d6b0e80f | 2708 | { |
9c02b525 | 2709 | /* Pick one at random, out of those which have had events. */ |
d6b0e80f | 2710 | |
9c02b525 | 2711 | /* First see how many events we have. */ |
d3a70e03 TT |
2712 | iterate_over_lwps (filter, |
2713 | [&] (struct lwp_info *info) | |
2714 | { | |
2715 | return count_events_callback (info, &num_events); | |
2716 | }); | |
8bf3b159 | 2717 | gdb_assert (num_events > 0); |
d6b0e80f | 2718 | |
9c02b525 PA |
2719 | /* Now randomly pick a LWP out of those that have had |
2720 | events. */ | |
d6b0e80f AC |
2721 | random_selector = (int) |
2722 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
2723 | ||
9327494e SM |
2724 | if (num_events > 1) |
2725 | linux_nat_debug_printf ("Found %d events, selecting #%d", | |
2726 | num_events, random_selector); | |
d6b0e80f | 2727 | |
d3a70e03 TT |
2728 | event_lp |
2729 | = (iterate_over_lwps | |
2730 | (filter, | |
2731 | [&] (struct lwp_info *info) | |
2732 | { | |
2733 | return select_event_lwp_callback (info, | |
2734 | &random_selector); | |
2735 | })); | |
d6b0e80f AC |
2736 | } |
2737 | ||
2738 | if (event_lp != NULL) | |
2739 | { | |
2740 | /* Switch the event LWP. */ | |
2741 | *orig_lp = event_lp; | |
2742 | *status = event_lp->status; | |
2743 | } | |
2744 | ||
2745 | /* Flush the wait status for the event LWP. */ | |
2746 | (*orig_lp)->status = 0; | |
2747 | } | |
2748 | ||
2749 | /* Return non-zero if LP has been resumed. */ | |
2750 | ||
2751 | static int | |
d3a70e03 | 2752 | resumed_callback (struct lwp_info *lp) |
d6b0e80f AC |
2753 | { |
2754 | return lp->resumed; | |
2755 | } | |
2756 | ||
02f3fc28 | 2757 | /* Check if we should go on and pass this event to common code. |
12d9289a | 2758 | |
897608ed SM |
2759 | If so, save the status to the lwp_info structure associated to LWPID. */ |
2760 | ||
2761 | static void | |
9c02b525 | 2762 | linux_nat_filter_event (int lwpid, int status) |
02f3fc28 PA |
2763 | { |
2764 | struct lwp_info *lp; | |
89a5711c | 2765 | int event = linux_ptrace_get_extended_event (status); |
02f3fc28 | 2766 | |
f2907e49 | 2767 | lp = find_lwp_pid (ptid_t (lwpid)); |
02f3fc28 | 2768 | |
1abeb1e9 PA |
2769 | /* Check for events reported by anything not in our LWP list. */ |
2770 | if (lp == nullptr) | |
0e5bf2a8 | 2771 | { |
1abeb1e9 PA |
2772 | if (WIFSTOPPED (status)) |
2773 | { | |
2774 | if (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC) | |
2775 | { | |
2776 | /* A non-leader thread exec'ed after we've seen the | |
2777 | leader zombie, and removed it from our lists (in | |
2778 | check_zombie_leaders). The non-leader thread changes | |
2779 | its tid to the tgid. */ | |
2780 | linux_nat_debug_printf | |
2781 | ("Re-adding thread group leader LWP %d after exec.", | |
2782 | lwpid); | |
0e5bf2a8 | 2783 | |
1abeb1e9 PA |
2784 | lp = add_lwp (ptid_t (lwpid, lwpid)); |
2785 | lp->stopped = 1; | |
2786 | lp->resumed = 1; | |
2787 | add_thread (linux_target, lp->ptid); | |
2788 | } | |
2789 | else | |
2790 | { | |
2791 | /* A process we are controlling has forked and the new | |
2792 | child's stop was reported to us by the kernel. Save | |
2793 | its PID and go back to waiting for the fork event to | |
2794 | be reported - the stopped process might be returned | |
2795 | from waitpid before or after the fork event is. */ | |
2796 | linux_nat_debug_printf | |
2797 | ("Saving LWP %d status %s in stopped_pids list", | |
2798 | lwpid, status_to_str (status).c_str ()); | |
2799 | add_to_pid_list (&stopped_pids, lwpid, status); | |
2800 | } | |
2801 | } | |
2802 | else | |
2803 | { | |
2804 | /* Don't report an event for the exit of an LWP not in our | |
2805 | list, i.e. not part of any inferior we're debugging. | |
2806 | This can happen if we detach from a program we originally | |
6cf20c46 PA |
2807 | forked and then it exits. However, note that we may have |
2808 | earlier deleted a leader of an inferior we're debugging, | |
2809 | in check_zombie_leaders. Re-add it back here if so. */ | |
2810 | for (inferior *inf : all_inferiors (linux_target)) | |
2811 | { | |
2812 | if (inf->pid == lwpid) | |
2813 | { | |
2814 | linux_nat_debug_printf | |
2815 | ("Re-adding thread group leader LWP %d after exit.", | |
2816 | lwpid); | |
2817 | ||
2818 | lp = add_lwp (ptid_t (lwpid, lwpid)); | |
2819 | lp->resumed = 1; | |
2820 | add_thread (linux_target, lp->ptid); | |
2821 | break; | |
2822 | } | |
2823 | } | |
1abeb1e9 | 2824 | } |
0e5bf2a8 | 2825 | |
1abeb1e9 PA |
2826 | if (lp == nullptr) |
2827 | return; | |
02f3fc28 PA |
2828 | } |
2829 | ||
8817a6f2 PA |
2830 | /* This LWP is stopped now. (And if dead, this prevents it from |
2831 | ever being continued.) */ | |
2832 | lp->stopped = 1; | |
2833 | ||
8784d563 PA |
2834 | if (WIFSTOPPED (status) && lp->must_set_ptrace_flags) |
2835 | { | |
5b6d1e4f | 2836 | inferior *inf = find_inferior_pid (linux_target, lp->ptid.pid ()); |
de0d863e | 2837 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 2838 | |
e38504b3 | 2839 | linux_enable_event_reporting (lp->ptid.lwp (), options); |
8784d563 PA |
2840 | lp->must_set_ptrace_flags = 0; |
2841 | } | |
2842 | ||
ca2163eb PA |
2843 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2844 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2845 | { | |
2846 | /* No longer need the sysgood bit. The ptrace event ends up | |
2847 | recorded in lp->waitstatus if we care for it. We can carry | |
2848 | on handling the event like a regular SIGTRAP from here | |
2849 | on. */ | |
2850 | status = W_STOPCODE (SIGTRAP); | |
2851 | if (linux_handle_syscall_trap (lp, 0)) | |
897608ed | 2852 | return; |
ca2163eb | 2853 | } |
bfd09d20 JS |
2854 | else |
2855 | { | |
2856 | /* Almost all other ptrace-stops are known to be outside of system | |
2857 | calls, with further exceptions in linux_handle_extended_wait. */ | |
2858 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2859 | } | |
02f3fc28 | 2860 | |
ca2163eb | 2861 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2862 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2863 | && linux_is_extended_waitstatus (status)) | |
02f3fc28 | 2864 | { |
9327494e SM |
2865 | linux_nat_debug_printf ("Handling extended status 0x%06x", status); |
2866 | ||
4dd63d48 | 2867 | if (linux_handle_extended_wait (lp, status)) |
897608ed | 2868 | return; |
02f3fc28 PA |
2869 | } |
2870 | ||
2871 | /* Check if the thread has exited. */ | |
9c02b525 PA |
2872 | if (WIFEXITED (status) || WIFSIGNALED (status)) |
2873 | { | |
6cf20c46 | 2874 | if (!report_thread_events && !is_leader (lp)) |
02f3fc28 | 2875 | { |
9327494e | 2876 | linux_nat_debug_printf ("%s exited.", |
e53c95d4 | 2877 | lp->ptid.to_string ().c_str ()); |
9c02b525 | 2878 | |
6cf20c46 | 2879 | /* If this was not the leader exiting, then the exit signal |
4a6ed09b PA |
2880 | was not the end of the debugged application and should be |
2881 | ignored. */ | |
2882 | exit_lwp (lp); | |
897608ed | 2883 | return; |
02f3fc28 PA |
2884 | } |
2885 | ||
77598427 PA |
2886 | /* Note that even if the leader was ptrace-stopped, it can still |
2887 | exit, if e.g., some other thread brings down the whole | |
2888 | process (calls `exit'). So don't assert that the lwp is | |
2889 | resumed. */ | |
9327494e SM |
2890 | linux_nat_debug_printf ("LWP %ld exited (resumed=%d)", |
2891 | lp->ptid.lwp (), lp->resumed); | |
02f3fc28 | 2892 | |
9c02b525 PA |
2893 | /* Dead LWP's aren't expected to reported a pending sigstop. */ |
2894 | lp->signalled = 0; | |
2895 | ||
2896 | /* Store the pending event in the waitstatus, because | |
2897 | W_EXITCODE(0,0) == 0. */ | |
7509b829 | 2898 | lp->waitstatus = host_status_to_waitstatus (status); |
897608ed | 2899 | return; |
02f3fc28 PA |
2900 | } |
2901 | ||
02f3fc28 PA |
2902 | /* Make sure we don't report a SIGSTOP that we sent ourselves in |
2903 | an attempt to stop an LWP. */ | |
2904 | if (lp->signalled | |
2905 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) | |
2906 | { | |
02f3fc28 PA |
2907 | lp->signalled = 0; |
2908 | ||
2bf6fb9d | 2909 | if (lp->last_resume_kind == resume_stop) |
25289eb2 | 2910 | { |
9327494e | 2911 | linux_nat_debug_printf ("resume_stop SIGSTOP caught for %s.", |
e53c95d4 | 2912 | lp->ptid.to_string ().c_str ()); |
2bf6fb9d PA |
2913 | } |
2914 | else | |
2915 | { | |
2916 | /* This is a delayed SIGSTOP. Filter out the event. */ | |
02f3fc28 | 2917 | |
9327494e SM |
2918 | linux_nat_debug_printf |
2919 | ("%s %s, 0, 0 (discard delayed SIGSTOP)", | |
2920 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 2921 | lp->ptid.to_string ().c_str ()); |
02f3fc28 | 2922 | |
2bf6fb9d | 2923 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
25289eb2 | 2924 | gdb_assert (lp->resumed); |
897608ed | 2925 | return; |
25289eb2 | 2926 | } |
02f3fc28 PA |
2927 | } |
2928 | ||
57380f4e DJ |
2929 | /* Make sure we don't report a SIGINT that we have already displayed |
2930 | for another thread. */ | |
2931 | if (lp->ignore_sigint | |
2932 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) | |
2933 | { | |
9327494e | 2934 | linux_nat_debug_printf ("Delayed SIGINT caught for %s.", |
e53c95d4 | 2935 | lp->ptid.to_string ().c_str ()); |
57380f4e DJ |
2936 | |
2937 | /* This is a delayed SIGINT. */ | |
2938 | lp->ignore_sigint = 0; | |
2939 | ||
8a99810d | 2940 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
9327494e SM |
2941 | linux_nat_debug_printf ("%s %s, 0, 0 (discard SIGINT)", |
2942 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 2943 | lp->ptid.to_string ().c_str ()); |
57380f4e DJ |
2944 | gdb_assert (lp->resumed); |
2945 | ||
2946 | /* Discard the event. */ | |
897608ed | 2947 | return; |
57380f4e DJ |
2948 | } |
2949 | ||
9c02b525 PA |
2950 | /* Don't report signals that GDB isn't interested in, such as |
2951 | signals that are neither printed nor stopped upon. Stopping all | |
7da6a5b9 | 2952 | threads can be a bit time-consuming, so if we want decent |
9c02b525 PA |
2953 | performance with heavily multi-threaded programs, especially when |
2954 | they're using a high frequency timer, we'd better avoid it if we | |
2955 | can. */ | |
2956 | if (WIFSTOPPED (status)) | |
2957 | { | |
2958 | enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status)); | |
2959 | ||
fbea99ea | 2960 | if (!target_is_non_stop_p ()) |
9c02b525 PA |
2961 | { |
2962 | /* Only do the below in all-stop, as we currently use SIGSTOP | |
2963 | to implement target_stop (see linux_nat_stop) in | |
2964 | non-stop. */ | |
2965 | if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0) | |
2966 | { | |
2967 | /* If ^C/BREAK is typed at the tty/console, SIGINT gets | |
2968 | forwarded to the entire process group, that is, all LWPs | |
2969 | will receive it - unless they're using CLONE_THREAD to | |
2970 | share signals. Since we only want to report it once, we | |
2971 | mark it as ignored for all LWPs except this one. */ | |
d3a70e03 | 2972 | iterate_over_lwps (ptid_t (lp->ptid.pid ()), set_ignore_sigint); |
9c02b525 PA |
2973 | lp->ignore_sigint = 0; |
2974 | } | |
2975 | else | |
2976 | maybe_clear_ignore_sigint (lp); | |
2977 | } | |
2978 | ||
2979 | /* When using hardware single-step, we need to report every signal. | |
c9587f88 | 2980 | Otherwise, signals in pass_mask may be short-circuited |
d8c06f22 AB |
2981 | except signals that might be caused by a breakpoint, or SIGSTOP |
2982 | if we sent the SIGSTOP and are waiting for it to arrive. */ | |
9c02b525 | 2983 | if (!lp->step |
c9587f88 | 2984 | && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status)) |
d8c06f22 | 2985 | && (WSTOPSIG (status) != SIGSTOP |
5b6d1e4f | 2986 | || !find_thread_ptid (linux_target, lp->ptid)->stop_requested) |
c9587f88 | 2987 | && !linux_wstatus_maybe_breakpoint (status)) |
9c02b525 PA |
2988 | { |
2989 | linux_resume_one_lwp (lp, lp->step, signo); | |
9327494e SM |
2990 | linux_nat_debug_printf |
2991 | ("%s %s, %s (preempt 'handle')", | |
2992 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 2993 | lp->ptid.to_string ().c_str (), |
9327494e SM |
2994 | (signo != GDB_SIGNAL_0 |
2995 | ? strsignal (gdb_signal_to_host (signo)) : "0")); | |
897608ed | 2996 | return; |
9c02b525 PA |
2997 | } |
2998 | } | |
2999 | ||
02f3fc28 PA |
3000 | /* An interesting event. */ |
3001 | gdb_assert (lp); | |
ca2163eb | 3002 | lp->status = status; |
e7ad2f14 | 3003 | save_stop_reason (lp); |
02f3fc28 PA |
3004 | } |
3005 | ||
0e5bf2a8 PA |
3006 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
3007 | their exits until all other threads in the group have exited. */ | |
3008 | ||
3009 | static void | |
3010 | check_zombie_leaders (void) | |
3011 | { | |
08036331 | 3012 | for (inferior *inf : all_inferiors ()) |
0e5bf2a8 PA |
3013 | { |
3014 | struct lwp_info *leader_lp; | |
3015 | ||
3016 | if (inf->pid == 0) | |
3017 | continue; | |
3018 | ||
f2907e49 | 3019 | leader_lp = find_lwp_pid (ptid_t (inf->pid)); |
0e5bf2a8 PA |
3020 | if (leader_lp != NULL |
3021 | /* Check if there are other threads in the group, as we may | |
6cf20c46 PA |
3022 | have raced with the inferior simply exiting. Note this |
3023 | isn't a watertight check. If the inferior is | |
3024 | multi-threaded and is exiting, it may be we see the | |
3025 | leader as zombie before we reap all the non-leader | |
3026 | threads. See comments below. */ | |
0e5bf2a8 | 3027 | && num_lwps (inf->pid) > 1 |
5f572dec | 3028 | && linux_proc_pid_is_zombie (inf->pid)) |
0e5bf2a8 | 3029 | { |
6cf20c46 PA |
3030 | /* A zombie leader in a multi-threaded program can mean one |
3031 | of three things: | |
3032 | ||
3033 | #1 - Only the leader exited, not the whole program, e.g., | |
3034 | with pthread_exit. Since we can't reap the leader's exit | |
3035 | status until all other threads are gone and reaped too, | |
3036 | we want to delete the zombie leader right away, as it | |
3037 | can't be debugged, we can't read its registers, etc. | |
3038 | This is the main reason we check for zombie leaders | |
3039 | disappearing. | |
3040 | ||
3041 | #2 - The whole thread-group/process exited (a group exit, | |
3042 | via e.g. exit(3), and there is (or will be shortly) an | |
3043 | exit reported for each thread in the process, and then | |
3044 | finally an exit for the leader once the non-leaders are | |
3045 | reaped. | |
3046 | ||
3047 | #3 - There are 3 or more threads in the group, and a | |
3048 | thread other than the leader exec'd. See comments on | |
3049 | exec events at the top of the file. | |
3050 | ||
3051 | Ideally we would never delete the leader for case #2. | |
3052 | Instead, we want to collect the exit status of each | |
3053 | non-leader thread, and then finally collect the exit | |
3054 | status of the leader as normal and use its exit code as | |
3055 | whole-process exit code. Unfortunately, there's no | |
3056 | race-free way to distinguish cases #1 and #2. We can't | |
3057 | assume the exit events for the non-leaders threads are | |
3058 | already pending in the kernel, nor can we assume the | |
3059 | non-leader threads are in zombie state already. Between | |
3060 | the leader becoming zombie and the non-leaders exiting | |
3061 | and becoming zombie themselves, there's a small time | |
3062 | window, so such a check would be racy. Temporarily | |
3063 | pausing all threads and checking to see if all threads | |
3064 | exit or not before re-resuming them would work in the | |
3065 | case that all threads are running right now, but it | |
3066 | wouldn't work if some thread is currently already | |
3067 | ptrace-stopped, e.g., due to scheduler-locking. | |
3068 | ||
3069 | So what we do is we delete the leader anyhow, and then | |
3070 | later on when we see its exit status, we re-add it back. | |
3071 | We also make sure that we only report a whole-process | |
3072 | exit when we see the leader exiting, as opposed to when | |
3073 | the last LWP in the LWP list exits, which can be a | |
3074 | non-leader if we deleted the leader here. */ | |
9327494e | 3075 | linux_nat_debug_printf ("Thread group leader %d zombie " |
6cf20c46 PA |
3076 | "(it exited, or another thread execd), " |
3077 | "deleting it.", | |
9327494e | 3078 | inf->pid); |
0e5bf2a8 PA |
3079 | exit_lwp (leader_lp); |
3080 | } | |
3081 | } | |
3082 | } | |
3083 | ||
aa01bd36 PA |
3084 | /* Convenience function that is called when the kernel reports an exit |
3085 | event. This decides whether to report the event to GDB as a | |
3086 | process exit event, a thread exit event, or to suppress the | |
3087 | event. */ | |
3088 | ||
3089 | static ptid_t | |
3090 | filter_exit_event (struct lwp_info *event_child, | |
3091 | struct target_waitstatus *ourstatus) | |
3092 | { | |
3093 | ptid_t ptid = event_child->ptid; | |
3094 | ||
6cf20c46 | 3095 | if (!is_leader (event_child)) |
aa01bd36 PA |
3096 | { |
3097 | if (report_thread_events) | |
183be222 | 3098 | ourstatus->set_thread_exited (0); |
aa01bd36 | 3099 | else |
183be222 | 3100 | ourstatus->set_ignore (); |
aa01bd36 PA |
3101 | |
3102 | exit_lwp (event_child); | |
3103 | } | |
3104 | ||
3105 | return ptid; | |
3106 | } | |
3107 | ||
d6b0e80f | 3108 | static ptid_t |
f6ac5f3d | 3109 | linux_nat_wait_1 (ptid_t ptid, struct target_waitstatus *ourstatus, |
b60cea74 | 3110 | target_wait_flags target_options) |
d6b0e80f | 3111 | { |
fc9b8e47 | 3112 | sigset_t prev_mask; |
4b60df3d | 3113 | enum resume_kind last_resume_kind; |
12d9289a | 3114 | struct lwp_info *lp; |
12d9289a | 3115 | int status; |
d6b0e80f | 3116 | |
9327494e | 3117 | linux_nat_debug_printf ("enter"); |
b84876c2 | 3118 | |
f973ed9c DJ |
3119 | /* The first time we get here after starting a new inferior, we may |
3120 | not have added it to the LWP list yet - this is the earliest | |
3121 | moment at which we know its PID. */ | |
677c92fe | 3122 | if (ptid.is_pid () && find_lwp_pid (ptid) == nullptr) |
f973ed9c | 3123 | { |
677c92fe | 3124 | ptid_t lwp_ptid (ptid.pid (), ptid.pid ()); |
27c9d204 | 3125 | |
677c92fe SM |
3126 | /* Upgrade the main thread's ptid. */ |
3127 | thread_change_ptid (linux_target, ptid, lwp_ptid); | |
3128 | lp = add_initial_lwp (lwp_ptid); | |
f973ed9c DJ |
3129 | lp->resumed = 1; |
3130 | } | |
3131 | ||
12696c10 | 3132 | /* Make sure SIGCHLD is blocked until the sigsuspend below. */ |
7feb7d06 | 3133 | block_child_signals (&prev_mask); |
d6b0e80f | 3134 | |
d6b0e80f | 3135 | /* First check if there is a LWP with a wait status pending. */ |
d3a70e03 | 3136 | lp = iterate_over_lwps (ptid, status_callback); |
8a99810d | 3137 | if (lp != NULL) |
d6b0e80f | 3138 | { |
9327494e | 3139 | linux_nat_debug_printf ("Using pending wait status %s for %s.", |
8d06918f | 3140 | status_to_str (lp->status).c_str (), |
e53c95d4 | 3141 | lp->ptid.to_string ().c_str ()); |
d6b0e80f AC |
3142 | } |
3143 | ||
9c02b525 PA |
3144 | /* But if we don't find a pending event, we'll have to wait. Always |
3145 | pull all events out of the kernel. We'll randomly select an | |
3146 | event LWP out of all that have events, to prevent starvation. */ | |
7feb7d06 | 3147 | |
d90e17a7 | 3148 | while (lp == NULL) |
d6b0e80f AC |
3149 | { |
3150 | pid_t lwpid; | |
3151 | ||
0e5bf2a8 PA |
3152 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
3153 | quirks: | |
3154 | ||
3155 | - If the thread group leader exits while other threads in the | |
3156 | thread group still exist, waitpid(TGID, ...) hangs. That | |
3157 | waitpid won't return an exit status until the other threads | |
85102364 | 3158 | in the group are reaped. |
0e5bf2a8 PA |
3159 | |
3160 | - When a non-leader thread execs, that thread just vanishes | |
3161 | without reporting an exit (so we'd hang if we waited for it | |
3162 | explicitly in that case). The exec event is reported to | |
3163 | the TGID pid. */ | |
3164 | ||
3165 | errno = 0; | |
4a6ed09b | 3166 | lwpid = my_waitpid (-1, &status, __WALL | WNOHANG); |
0e5bf2a8 | 3167 | |
9327494e SM |
3168 | linux_nat_debug_printf ("waitpid(-1, ...) returned %d, %s", |
3169 | lwpid, | |
3170 | errno ? safe_strerror (errno) : "ERRNO-OK"); | |
b84876c2 | 3171 | |
d6b0e80f AC |
3172 | if (lwpid > 0) |
3173 | { | |
9327494e | 3174 | linux_nat_debug_printf ("waitpid %ld received %s", |
8d06918f SM |
3175 | (long) lwpid, |
3176 | status_to_str (status).c_str ()); | |
d6b0e80f | 3177 | |
9c02b525 | 3178 | linux_nat_filter_event (lwpid, status); |
0e5bf2a8 PA |
3179 | /* Retry until nothing comes out of waitpid. A single |
3180 | SIGCHLD can indicate more than one child stopped. */ | |
3181 | continue; | |
d6b0e80f AC |
3182 | } |
3183 | ||
20ba1ce6 PA |
3184 | /* Now that we've pulled all events out of the kernel, resume |
3185 | LWPs that don't have an interesting event to report. */ | |
3186 | iterate_over_lwps (minus_one_ptid, | |
d3a70e03 TT |
3187 | [] (struct lwp_info *info) |
3188 | { | |
3189 | return resume_stopped_resumed_lwps (info, minus_one_ptid); | |
3190 | }); | |
20ba1ce6 PA |
3191 | |
3192 | /* ... and find an LWP with a status to report to the core, if | |
3193 | any. */ | |
d3a70e03 | 3194 | lp = iterate_over_lwps (ptid, status_callback); |
9c02b525 PA |
3195 | if (lp != NULL) |
3196 | break; | |
3197 | ||
0e5bf2a8 PA |
3198 | /* Check for zombie thread group leaders. Those can't be reaped |
3199 | until all other threads in the thread group are. */ | |
3200 | check_zombie_leaders (); | |
d6b0e80f | 3201 | |
0e5bf2a8 PA |
3202 | /* If there are no resumed children left, bail. We'd be stuck |
3203 | forever in the sigsuspend call below otherwise. */ | |
d3a70e03 | 3204 | if (iterate_over_lwps (ptid, resumed_callback) == NULL) |
0e5bf2a8 | 3205 | { |
9327494e | 3206 | linux_nat_debug_printf ("exit (no resumed LWP)"); |
b84876c2 | 3207 | |
183be222 | 3208 | ourstatus->set_no_resumed (); |
b84876c2 | 3209 | |
0e5bf2a8 PA |
3210 | restore_child_signals_mask (&prev_mask); |
3211 | return minus_one_ptid; | |
d6b0e80f | 3212 | } |
28736962 | 3213 | |
0e5bf2a8 PA |
3214 | /* No interesting event to report to the core. */ |
3215 | ||
3216 | if (target_options & TARGET_WNOHANG) | |
3217 | { | |
9327494e | 3218 | linux_nat_debug_printf ("exit (ignore)"); |
28736962 | 3219 | |
183be222 | 3220 | ourstatus->set_ignore (); |
28736962 PA |
3221 | restore_child_signals_mask (&prev_mask); |
3222 | return minus_one_ptid; | |
3223 | } | |
d6b0e80f AC |
3224 | |
3225 | /* We shouldn't end up here unless we want to try again. */ | |
d90e17a7 | 3226 | gdb_assert (lp == NULL); |
0e5bf2a8 PA |
3227 | |
3228 | /* Block until we get an event reported with SIGCHLD. */ | |
9c3a5d93 | 3229 | wait_for_signal (); |
d6b0e80f AC |
3230 | } |
3231 | ||
d6b0e80f AC |
3232 | gdb_assert (lp); |
3233 | ||
ca2163eb PA |
3234 | status = lp->status; |
3235 | lp->status = 0; | |
3236 | ||
fbea99ea | 3237 | if (!target_is_non_stop_p ()) |
4c28f408 PA |
3238 | { |
3239 | /* Now stop all other LWP's ... */ | |
d3a70e03 | 3240 | iterate_over_lwps (minus_one_ptid, stop_callback); |
4c28f408 PA |
3241 | |
3242 | /* ... and wait until all of them have reported back that | |
3243 | they're no longer running. */ | |
d3a70e03 | 3244 | iterate_over_lwps (minus_one_ptid, stop_wait_callback); |
9c02b525 PA |
3245 | } |
3246 | ||
3247 | /* If we're not waiting for a specific LWP, choose an event LWP from | |
3248 | among those that have had events. Giving equal priority to all | |
3249 | LWPs that have had events helps prevent starvation. */ | |
d7e15655 | 3250 | if (ptid == minus_one_ptid || ptid.is_pid ()) |
9c02b525 PA |
3251 | select_event_lwp (ptid, &lp, &status); |
3252 | ||
3253 | gdb_assert (lp != NULL); | |
3254 | ||
3255 | /* Now that we've selected our final event LWP, un-adjust its PC if | |
faf09f01 PA |
3256 | it was a software breakpoint, and we can't reliably support the |
3257 | "stopped by software breakpoint" stop reason. */ | |
3258 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT | |
3259 | && !USE_SIGTRAP_SIGINFO) | |
9c02b525 | 3260 | { |
5b6d1e4f | 3261 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 3262 | struct gdbarch *gdbarch = regcache->arch (); |
527a273a | 3263 | int decr_pc = gdbarch_decr_pc_after_break (gdbarch); |
4c28f408 | 3264 | |
9c02b525 PA |
3265 | if (decr_pc != 0) |
3266 | { | |
3267 | CORE_ADDR pc; | |
d6b0e80f | 3268 | |
9c02b525 PA |
3269 | pc = regcache_read_pc (regcache); |
3270 | regcache_write_pc (regcache, pc + decr_pc); | |
3271 | } | |
3272 | } | |
e3e9f5a2 | 3273 | |
9c02b525 PA |
3274 | /* We'll need this to determine whether to report a SIGSTOP as |
3275 | GDB_SIGNAL_0. Need to take a copy because resume_clear_callback | |
3276 | clears it. */ | |
3277 | last_resume_kind = lp->last_resume_kind; | |
4b60df3d | 3278 | |
fbea99ea | 3279 | if (!target_is_non_stop_p ()) |
9c02b525 | 3280 | { |
e3e9f5a2 PA |
3281 | /* In all-stop, from the core's perspective, all LWPs are now |
3282 | stopped until a new resume action is sent over. */ | |
d3a70e03 | 3283 | iterate_over_lwps (minus_one_ptid, resume_clear_callback); |
e3e9f5a2 PA |
3284 | } |
3285 | else | |
25289eb2 | 3286 | { |
d3a70e03 | 3287 | resume_clear_callback (lp); |
25289eb2 | 3288 | } |
d6b0e80f | 3289 | |
135340af | 3290 | if (linux_target->low_status_is_event (status)) |
d6b0e80f | 3291 | { |
9327494e | 3292 | linux_nat_debug_printf ("trap ptid is %s.", |
e53c95d4 | 3293 | lp->ptid.to_string ().c_str ()); |
d6b0e80f | 3294 | } |
d6b0e80f | 3295 | |
183be222 | 3296 | if (lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE) |
d6b0e80f AC |
3297 | { |
3298 | *ourstatus = lp->waitstatus; | |
183be222 | 3299 | lp->waitstatus.set_ignore (); |
d6b0e80f AC |
3300 | } |
3301 | else | |
7509b829 | 3302 | *ourstatus = host_status_to_waitstatus (status); |
d6b0e80f | 3303 | |
9327494e | 3304 | linux_nat_debug_printf ("exit"); |
b84876c2 | 3305 | |
7feb7d06 | 3306 | restore_child_signals_mask (&prev_mask); |
1e225492 | 3307 | |
4b60df3d | 3308 | if (last_resume_kind == resume_stop |
183be222 | 3309 | && ourstatus->kind () == TARGET_WAITKIND_STOPPED |
25289eb2 PA |
3310 | && WSTOPSIG (status) == SIGSTOP) |
3311 | { | |
3312 | /* A thread that has been requested to stop by GDB with | |
3313 | target_stop, and it stopped cleanly, so report as SIG0. The | |
3314 | use of SIGSTOP is an implementation detail. */ | |
183be222 | 3315 | ourstatus->set_stopped (GDB_SIGNAL_0); |
25289eb2 PA |
3316 | } |
3317 | ||
183be222 SM |
3318 | if (ourstatus->kind () == TARGET_WAITKIND_EXITED |
3319 | || ourstatus->kind () == TARGET_WAITKIND_SIGNALLED) | |
1e225492 JK |
3320 | lp->core = -1; |
3321 | else | |
2e794194 | 3322 | lp->core = linux_common_core_of_thread (lp->ptid); |
1e225492 | 3323 | |
183be222 | 3324 | if (ourstatus->kind () == TARGET_WAITKIND_EXITED) |
aa01bd36 PA |
3325 | return filter_exit_event (lp, ourstatus); |
3326 | ||
f973ed9c | 3327 | return lp->ptid; |
d6b0e80f AC |
3328 | } |
3329 | ||
e3e9f5a2 PA |
3330 | /* Resume LWPs that are currently stopped without any pending status |
3331 | to report, but are resumed from the core's perspective. */ | |
3332 | ||
3333 | static int | |
d3a70e03 | 3334 | resume_stopped_resumed_lwps (struct lwp_info *lp, const ptid_t wait_ptid) |
e3e9f5a2 | 3335 | { |
4dd63d48 PA |
3336 | if (!lp->stopped) |
3337 | { | |
9327494e | 3338 | linux_nat_debug_printf ("NOT resuming LWP %s, not stopped", |
e53c95d4 | 3339 | lp->ptid.to_string ().c_str ()); |
4dd63d48 PA |
3340 | } |
3341 | else if (!lp->resumed) | |
3342 | { | |
9327494e | 3343 | linux_nat_debug_printf ("NOT resuming LWP %s, not resumed", |
e53c95d4 | 3344 | lp->ptid.to_string ().c_str ()); |
4dd63d48 PA |
3345 | } |
3346 | else if (lwp_status_pending_p (lp)) | |
3347 | { | |
9327494e | 3348 | linux_nat_debug_printf ("NOT resuming LWP %s, has pending status", |
e53c95d4 | 3349 | lp->ptid.to_string ().c_str ()); |
4dd63d48 PA |
3350 | } |
3351 | else | |
e3e9f5a2 | 3352 | { |
5b6d1e4f | 3353 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 3354 | struct gdbarch *gdbarch = regcache->arch (); |
336060f3 | 3355 | |
a70b8144 | 3356 | try |
e3e9f5a2 | 3357 | { |
23f238d3 PA |
3358 | CORE_ADDR pc = regcache_read_pc (regcache); |
3359 | int leave_stopped = 0; | |
e3e9f5a2 | 3360 | |
23f238d3 PA |
3361 | /* Don't bother if there's a breakpoint at PC that we'd hit |
3362 | immediately, and we're not waiting for this LWP. */ | |
d3a70e03 | 3363 | if (!lp->ptid.matches (wait_ptid)) |
23f238d3 | 3364 | { |
a01bda52 | 3365 | if (breakpoint_inserted_here_p (regcache->aspace (), pc)) |
23f238d3 PA |
3366 | leave_stopped = 1; |
3367 | } | |
e3e9f5a2 | 3368 | |
23f238d3 PA |
3369 | if (!leave_stopped) |
3370 | { | |
9327494e SM |
3371 | linux_nat_debug_printf |
3372 | ("resuming stopped-resumed LWP %s at %s: step=%d", | |
e53c95d4 | 3373 | lp->ptid.to_string ().c_str (), paddress (gdbarch, pc), |
9327494e | 3374 | lp->step); |
23f238d3 PA |
3375 | |
3376 | linux_resume_one_lwp_throw (lp, lp->step, GDB_SIGNAL_0); | |
3377 | } | |
3378 | } | |
230d2906 | 3379 | catch (const gdb_exception_error &ex) |
23f238d3 PA |
3380 | { |
3381 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 3382 | throw; |
23f238d3 | 3383 | } |
e3e9f5a2 PA |
3384 | } |
3385 | ||
3386 | return 0; | |
3387 | } | |
3388 | ||
f6ac5f3d PA |
3389 | ptid_t |
3390 | linux_nat_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus, | |
b60cea74 | 3391 | target_wait_flags target_options) |
7feb7d06 PA |
3392 | { |
3393 | ptid_t event_ptid; | |
3394 | ||
e53c95d4 | 3395 | linux_nat_debug_printf ("[%s], [%s]", ptid.to_string ().c_str (), |
9327494e | 3396 | target_options_to_string (target_options).c_str ()); |
7feb7d06 PA |
3397 | |
3398 | /* Flush the async file first. */ | |
d9d41e78 | 3399 | if (target_is_async_p ()) |
7feb7d06 PA |
3400 | async_file_flush (); |
3401 | ||
e3e9f5a2 PA |
3402 | /* Resume LWPs that are currently stopped without any pending status |
3403 | to report, but are resumed from the core's perspective. LWPs get | |
3404 | in this state if we find them stopping at a time we're not | |
3405 | interested in reporting the event (target_wait on a | |
3406 | specific_process, for example, see linux_nat_wait_1), and | |
3407 | meanwhile the event became uninteresting. Don't bother resuming | |
3408 | LWPs we're not going to wait for if they'd stop immediately. */ | |
fbea99ea | 3409 | if (target_is_non_stop_p ()) |
d3a70e03 TT |
3410 | iterate_over_lwps (minus_one_ptid, |
3411 | [=] (struct lwp_info *info) | |
3412 | { | |
3413 | return resume_stopped_resumed_lwps (info, ptid); | |
3414 | }); | |
e3e9f5a2 | 3415 | |
f6ac5f3d | 3416 | event_ptid = linux_nat_wait_1 (ptid, ourstatus, target_options); |
7feb7d06 PA |
3417 | |
3418 | /* If we requested any event, and something came out, assume there | |
3419 | may be more. If we requested a specific lwp or process, also | |
3420 | assume there may be more. */ | |
d9d41e78 | 3421 | if (target_is_async_p () |
183be222 SM |
3422 | && ((ourstatus->kind () != TARGET_WAITKIND_IGNORE |
3423 | && ourstatus->kind () != TARGET_WAITKIND_NO_RESUMED) | |
d7e15655 | 3424 | || ptid != minus_one_ptid)) |
7feb7d06 PA |
3425 | async_file_mark (); |
3426 | ||
7feb7d06 PA |
3427 | return event_ptid; |
3428 | } | |
3429 | ||
1d2736d4 PA |
3430 | /* Kill one LWP. */ |
3431 | ||
3432 | static void | |
3433 | kill_one_lwp (pid_t pid) | |
d6b0e80f | 3434 | { |
ed731959 JK |
3435 | /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
3436 | ||
3437 | errno = 0; | |
1d2736d4 | 3438 | kill_lwp (pid, SIGKILL); |
9327494e | 3439 | |
ed731959 | 3440 | if (debug_linux_nat) |
57745c90 PA |
3441 | { |
3442 | int save_errno = errno; | |
3443 | ||
9327494e SM |
3444 | linux_nat_debug_printf |
3445 | ("kill (SIGKILL) %ld, 0, 0 (%s)", (long) pid, | |
3446 | save_errno != 0 ? safe_strerror (save_errno) : "OK"); | |
57745c90 | 3447 | } |
ed731959 JK |
3448 | |
3449 | /* Some kernels ignore even SIGKILL for processes under ptrace. */ | |
3450 | ||
d6b0e80f | 3451 | errno = 0; |
1d2736d4 | 3452 | ptrace (PTRACE_KILL, pid, 0, 0); |
d6b0e80f | 3453 | if (debug_linux_nat) |
57745c90 PA |
3454 | { |
3455 | int save_errno = errno; | |
3456 | ||
9327494e SM |
3457 | linux_nat_debug_printf |
3458 | ("PTRACE_KILL %ld, 0, 0 (%s)", (long) pid, | |
3459 | save_errno ? safe_strerror (save_errno) : "OK"); | |
57745c90 | 3460 | } |
d6b0e80f AC |
3461 | } |
3462 | ||
1d2736d4 PA |
3463 | /* Wait for an LWP to die. */ |
3464 | ||
3465 | static void | |
3466 | kill_wait_one_lwp (pid_t pid) | |
d6b0e80f | 3467 | { |
1d2736d4 | 3468 | pid_t res; |
d6b0e80f AC |
3469 | |
3470 | /* We must make sure that there are no pending events (delayed | |
3471 | SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current | |
3472 | program doesn't interfere with any following debugging session. */ | |
3473 | ||
d6b0e80f AC |
3474 | do |
3475 | { | |
1d2736d4 PA |
3476 | res = my_waitpid (pid, NULL, __WALL); |
3477 | if (res != (pid_t) -1) | |
d6b0e80f | 3478 | { |
9327494e SM |
3479 | linux_nat_debug_printf ("wait %ld received unknown.", (long) pid); |
3480 | ||
4a6ed09b PA |
3481 | /* The Linux kernel sometimes fails to kill a thread |
3482 | completely after PTRACE_KILL; that goes from the stop | |
3483 | point in do_fork out to the one in get_signal_to_deliver | |
3484 | and waits again. So kill it again. */ | |
1d2736d4 | 3485 | kill_one_lwp (pid); |
d6b0e80f AC |
3486 | } |
3487 | } | |
1d2736d4 PA |
3488 | while (res == pid); |
3489 | ||
3490 | gdb_assert (res == -1 && errno == ECHILD); | |
3491 | } | |
3492 | ||
3493 | /* Callback for iterate_over_lwps. */ | |
d6b0e80f | 3494 | |
1d2736d4 | 3495 | static int |
d3a70e03 | 3496 | kill_callback (struct lwp_info *lp) |
1d2736d4 | 3497 | { |
e38504b3 | 3498 | kill_one_lwp (lp->ptid.lwp ()); |
d6b0e80f AC |
3499 | return 0; |
3500 | } | |
3501 | ||
1d2736d4 PA |
3502 | /* Callback for iterate_over_lwps. */ |
3503 | ||
3504 | static int | |
d3a70e03 | 3505 | kill_wait_callback (struct lwp_info *lp) |
1d2736d4 | 3506 | { |
e38504b3 | 3507 | kill_wait_one_lwp (lp->ptid.lwp ()); |
1d2736d4 PA |
3508 | return 0; |
3509 | } | |
3510 | ||
3511 | /* Kill the fork children of any threads of inferior INF that are | |
3512 | stopped at a fork event. */ | |
3513 | ||
3514 | static void | |
3515 | kill_unfollowed_fork_children (struct inferior *inf) | |
3516 | { | |
08036331 PA |
3517 | for (thread_info *thread : inf->non_exited_threads ()) |
3518 | { | |
3519 | struct target_waitstatus *ws = &thread->pending_follow; | |
1d2736d4 | 3520 | |
183be222 SM |
3521 | if (ws->kind () == TARGET_WAITKIND_FORKED |
3522 | || ws->kind () == TARGET_WAITKIND_VFORKED) | |
08036331 | 3523 | { |
183be222 | 3524 | ptid_t child_ptid = ws->child_ptid (); |
08036331 PA |
3525 | int child_pid = child_ptid.pid (); |
3526 | int child_lwp = child_ptid.lwp (); | |
3527 | ||
3528 | kill_one_lwp (child_lwp); | |
3529 | kill_wait_one_lwp (child_lwp); | |
3530 | ||
3531 | /* Let the arch-specific native code know this process is | |
3532 | gone. */ | |
3533 | linux_target->low_forget_process (child_pid); | |
3534 | } | |
3535 | } | |
1d2736d4 PA |
3536 | } |
3537 | ||
f6ac5f3d PA |
3538 | void |
3539 | linux_nat_target::kill () | |
d6b0e80f | 3540 | { |
f973ed9c DJ |
3541 | /* If we're stopped while forking and we haven't followed yet, |
3542 | kill the other task. We need to do this first because the | |
3543 | parent will be sleeping if this is a vfork. */ | |
1d2736d4 | 3544 | kill_unfollowed_fork_children (current_inferior ()); |
f973ed9c DJ |
3545 | |
3546 | if (forks_exist_p ()) | |
7feb7d06 | 3547 | linux_fork_killall (); |
f973ed9c DJ |
3548 | else |
3549 | { | |
e99b03dc | 3550 | ptid_t ptid = ptid_t (inferior_ptid.pid ()); |
e0881a8e | 3551 | |
4c28f408 | 3552 | /* Stop all threads before killing them, since ptrace requires |
30baf67b | 3553 | that the thread is stopped to successfully PTRACE_KILL. */ |
d3a70e03 | 3554 | iterate_over_lwps (ptid, stop_callback); |
4c28f408 PA |
3555 | /* ... and wait until all of them have reported back that |
3556 | they're no longer running. */ | |
d3a70e03 | 3557 | iterate_over_lwps (ptid, stop_wait_callback); |
4c28f408 | 3558 | |
f973ed9c | 3559 | /* Kill all LWP's ... */ |
d3a70e03 | 3560 | iterate_over_lwps (ptid, kill_callback); |
f973ed9c DJ |
3561 | |
3562 | /* ... and wait until we've flushed all events. */ | |
d3a70e03 | 3563 | iterate_over_lwps (ptid, kill_wait_callback); |
f973ed9c DJ |
3564 | } |
3565 | ||
bc1e6c81 | 3566 | target_mourn_inferior (inferior_ptid); |
d6b0e80f AC |
3567 | } |
3568 | ||
f6ac5f3d PA |
3569 | void |
3570 | linux_nat_target::mourn_inferior () | |
d6b0e80f | 3571 | { |
e99b03dc | 3572 | int pid = inferior_ptid.pid (); |
26cb8b7c PA |
3573 | |
3574 | purge_lwp_list (pid); | |
d6b0e80f | 3575 | |
8a89ddbd | 3576 | close_proc_mem_file (pid); |
05c06f31 | 3577 | |
f973ed9c | 3578 | if (! forks_exist_p ()) |
d90e17a7 | 3579 | /* Normal case, no other forks available. */ |
f6ac5f3d | 3580 | inf_ptrace_target::mourn_inferior (); |
f973ed9c DJ |
3581 | else |
3582 | /* Multi-fork case. The current inferior_ptid has exited, but | |
3583 | there are other viable forks to debug. Delete the exiting | |
3584 | one and context-switch to the first available. */ | |
3585 | linux_fork_mourn_inferior (); | |
26cb8b7c PA |
3586 | |
3587 | /* Let the arch-specific native code know this process is gone. */ | |
135340af | 3588 | linux_target->low_forget_process (pid); |
d6b0e80f AC |
3589 | } |
3590 | ||
5b009018 PA |
3591 | /* Convert a native/host siginfo object, into/from the siginfo in the |
3592 | layout of the inferiors' architecture. */ | |
3593 | ||
3594 | static void | |
a5362b9a | 3595 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
5b009018 | 3596 | { |
135340af PA |
3597 | /* If the low target didn't do anything, then just do a straight |
3598 | memcpy. */ | |
3599 | if (!linux_target->low_siginfo_fixup (siginfo, inf_siginfo, direction)) | |
5b009018 PA |
3600 | { |
3601 | if (direction == 1) | |
a5362b9a | 3602 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
5b009018 | 3603 | else |
a5362b9a | 3604 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
5b009018 PA |
3605 | } |
3606 | } | |
3607 | ||
9b409511 | 3608 | static enum target_xfer_status |
f6ac5f3d | 3609 | linux_xfer_siginfo (enum target_object object, |
dda83cd7 | 3610 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
3611 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
3612 | ULONGEST *xfered_len) | |
4aa995e1 | 3613 | { |
4aa995e1 | 3614 | int pid; |
a5362b9a TS |
3615 | siginfo_t siginfo; |
3616 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; | |
4aa995e1 PA |
3617 | |
3618 | gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO); | |
3619 | gdb_assert (readbuf || writebuf); | |
3620 | ||
e38504b3 | 3621 | pid = inferior_ptid.lwp (); |
4aa995e1 | 3622 | if (pid == 0) |
e99b03dc | 3623 | pid = inferior_ptid.pid (); |
4aa995e1 PA |
3624 | |
3625 | if (offset > sizeof (siginfo)) | |
2ed4b548 | 3626 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3627 | |
3628 | errno = 0; | |
3629 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3630 | if (errno != 0) | |
2ed4b548 | 3631 | return TARGET_XFER_E_IO; |
4aa995e1 | 3632 | |
5b009018 PA |
3633 | /* When GDB is built as a 64-bit application, ptrace writes into |
3634 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
3635 | inferior with a 64-bit GDB should look the same as debugging it | |
3636 | with a 32-bit GDB, we need to convert it. GDB core always sees | |
3637 | the converted layout, so any read/write will have to be done | |
3638 | post-conversion. */ | |
3639 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
3640 | ||
4aa995e1 PA |
3641 | if (offset + len > sizeof (siginfo)) |
3642 | len = sizeof (siginfo) - offset; | |
3643 | ||
3644 | if (readbuf != NULL) | |
5b009018 | 3645 | memcpy (readbuf, inf_siginfo + offset, len); |
4aa995e1 PA |
3646 | else |
3647 | { | |
5b009018 PA |
3648 | memcpy (inf_siginfo + offset, writebuf, len); |
3649 | ||
3650 | /* Convert back to ptrace layout before flushing it out. */ | |
3651 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
3652 | ||
4aa995e1 PA |
3653 | errno = 0; |
3654 | ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3655 | if (errno != 0) | |
2ed4b548 | 3656 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3657 | } |
3658 | ||
9b409511 YQ |
3659 | *xfered_len = len; |
3660 | return TARGET_XFER_OK; | |
4aa995e1 PA |
3661 | } |
3662 | ||
9b409511 | 3663 | static enum target_xfer_status |
f6ac5f3d PA |
3664 | linux_nat_xfer_osdata (enum target_object object, |
3665 | const char *annex, gdb_byte *readbuf, | |
3666 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, | |
3667 | ULONGEST *xfered_len); | |
3668 | ||
f6ac5f3d | 3669 | static enum target_xfer_status |
05c06f31 PA |
3670 | linux_proc_xfer_memory_partial (gdb_byte *readbuf, const gdb_byte *writebuf, |
3671 | ULONGEST offset, LONGEST len, ULONGEST *xfered_len); | |
f6ac5f3d PA |
3672 | |
3673 | enum target_xfer_status | |
3674 | linux_nat_target::xfer_partial (enum target_object object, | |
3675 | const char *annex, gdb_byte *readbuf, | |
3676 | const gdb_byte *writebuf, | |
3677 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) | |
d6b0e80f | 3678 | { |
4aa995e1 | 3679 | if (object == TARGET_OBJECT_SIGNAL_INFO) |
f6ac5f3d | 3680 | return linux_xfer_siginfo (object, annex, readbuf, writebuf, |
9b409511 | 3681 | offset, len, xfered_len); |
4aa995e1 | 3682 | |
c35b1492 PA |
3683 | /* The target is connected but no live inferior is selected. Pass |
3684 | this request down to a lower stratum (e.g., the executable | |
3685 | file). */ | |
d7e15655 | 3686 | if (object == TARGET_OBJECT_MEMORY && inferior_ptid == null_ptid) |
9b409511 | 3687 | return TARGET_XFER_EOF; |
c35b1492 | 3688 | |
f6ac5f3d PA |
3689 | if (object == TARGET_OBJECT_AUXV) |
3690 | return memory_xfer_auxv (this, object, annex, readbuf, writebuf, | |
3691 | offset, len, xfered_len); | |
3692 | ||
3693 | if (object == TARGET_OBJECT_OSDATA) | |
3694 | return linux_nat_xfer_osdata (object, annex, readbuf, writebuf, | |
3695 | offset, len, xfered_len); | |
d6b0e80f | 3696 | |
f6ac5f3d PA |
3697 | if (object == TARGET_OBJECT_MEMORY) |
3698 | { | |
05c06f31 PA |
3699 | /* GDB calculates all addresses in the largest possible address |
3700 | width. The address width must be masked before its final use | |
3701 | by linux_proc_xfer_partial. | |
3702 | ||
3703 | Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ | |
f6ac5f3d PA |
3704 | int addr_bit = gdbarch_addr_bit (target_gdbarch ()); |
3705 | ||
3706 | if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) | |
3707 | offset &= ((ULONGEST) 1 << addr_bit) - 1; | |
f6ac5f3d | 3708 | |
dd09fe0d KS |
3709 | /* If /proc/pid/mem is writable, don't fallback to ptrace. If |
3710 | the write via /proc/pid/mem fails because the inferior execed | |
3711 | (and we haven't seen the exec event yet), a subsequent ptrace | |
3712 | poke would incorrectly write memory to the post-exec address | |
3713 | space, while the core was trying to write to the pre-exec | |
3714 | address space. */ | |
3715 | if (proc_mem_file_is_writable ()) | |
3716 | return linux_proc_xfer_memory_partial (readbuf, writebuf, | |
3717 | offset, len, xfered_len); | |
05c06f31 | 3718 | } |
f6ac5f3d PA |
3719 | |
3720 | return inf_ptrace_target::xfer_partial (object, annex, readbuf, writebuf, | |
3721 | offset, len, xfered_len); | |
d6b0e80f AC |
3722 | } |
3723 | ||
57810aa7 | 3724 | bool |
f6ac5f3d | 3725 | linux_nat_target::thread_alive (ptid_t ptid) |
28439f5e | 3726 | { |
4a6ed09b PA |
3727 | /* As long as a PTID is in lwp list, consider it alive. */ |
3728 | return find_lwp_pid (ptid) != NULL; | |
28439f5e PA |
3729 | } |
3730 | ||
8a06aea7 PA |
3731 | /* Implement the to_update_thread_list target method for this |
3732 | target. */ | |
3733 | ||
f6ac5f3d PA |
3734 | void |
3735 | linux_nat_target::update_thread_list () | |
8a06aea7 | 3736 | { |
4a6ed09b PA |
3737 | /* We add/delete threads from the list as clone/exit events are |
3738 | processed, so just try deleting exited threads still in the | |
3739 | thread list. */ | |
3740 | delete_exited_threads (); | |
a6904d5a PA |
3741 | |
3742 | /* Update the processor core that each lwp/thread was last seen | |
3743 | running on. */ | |
901b9821 | 3744 | for (lwp_info *lwp : all_lwps ()) |
1ad3de98 PA |
3745 | { |
3746 | /* Avoid accessing /proc if the thread hasn't run since we last | |
3747 | time we fetched the thread's core. Accessing /proc becomes | |
3748 | noticeably expensive when we have thousands of LWPs. */ | |
3749 | if (lwp->core == -1) | |
3750 | lwp->core = linux_common_core_of_thread (lwp->ptid); | |
3751 | } | |
8a06aea7 PA |
3752 | } |
3753 | ||
a068643d | 3754 | std::string |
f6ac5f3d | 3755 | linux_nat_target::pid_to_str (ptid_t ptid) |
d6b0e80f | 3756 | { |
15a9e13e | 3757 | if (ptid.lwp_p () |
e38504b3 | 3758 | && (ptid.pid () != ptid.lwp () |
e99b03dc | 3759 | || num_lwps (ptid.pid ()) > 1)) |
a068643d | 3760 | return string_printf ("LWP %ld", ptid.lwp ()); |
d6b0e80f AC |
3761 | |
3762 | return normal_pid_to_str (ptid); | |
3763 | } | |
3764 | ||
f6ac5f3d PA |
3765 | const char * |
3766 | linux_nat_target::thread_name (struct thread_info *thr) | |
4694da01 | 3767 | { |
79efa585 | 3768 | return linux_proc_tid_get_name (thr->ptid); |
4694da01 TT |
3769 | } |
3770 | ||
dba24537 AC |
3771 | /* Accepts an integer PID; Returns a string representing a file that |
3772 | can be opened to get the symbols for the child process. */ | |
3773 | ||
0e90c441 | 3774 | const char * |
f6ac5f3d | 3775 | linux_nat_target::pid_to_exec_file (int pid) |
dba24537 | 3776 | { |
e0d86d2c | 3777 | return linux_proc_pid_to_exec_file (pid); |
dba24537 AC |
3778 | } |
3779 | ||
8a89ddbd PA |
3780 | /* Object representing an /proc/PID/mem open file. We keep one such |
3781 | file open per inferior. | |
3782 | ||
3783 | It might be tempting to think about only ever opening one file at | |
3784 | most for all inferiors, closing/reopening the file as we access | |
3785 | memory of different inferiors, to minimize number of file | |
3786 | descriptors open, which can otherwise run into resource limits. | |
3787 | However, that does not work correctly -- if the inferior execs and | |
3788 | we haven't processed the exec event yet, and, we opened a | |
3789 | /proc/PID/mem file, we will get a mem file accessing the post-exec | |
3790 | address space, thinking we're opening it for the pre-exec address | |
3791 | space. That is dangerous as we can poke memory (e.g. clearing | |
3792 | breakpoints) in the post-exec memory by mistake, corrupting the | |
3793 | inferior. For that reason, we open the mem file as early as | |
3794 | possible, right after spawning, forking or attaching to the | |
3795 | inferior, when the inferior is stopped and thus before it has a | |
3796 | chance of execing. | |
3797 | ||
3798 | Note that after opening the file, even if the thread we opened it | |
3799 | for subsequently exits, the open file is still usable for accessing | |
3800 | memory. It's only when the whole process exits or execs that the | |
3801 | file becomes invalid, at which point reads/writes return EOF. */ | |
3802 | ||
3803 | class proc_mem_file | |
3804 | { | |
3805 | public: | |
3806 | proc_mem_file (ptid_t ptid, int fd) | |
3807 | : m_ptid (ptid), m_fd (fd) | |
3808 | { | |
3809 | gdb_assert (m_fd != -1); | |
3810 | } | |
05c06f31 | 3811 | |
8a89ddbd | 3812 | ~proc_mem_file () |
05c06f31 | 3813 | { |
89662f69 | 3814 | linux_nat_debug_printf ("closing fd %d for /proc/%d/task/%ld/mem", |
8a89ddbd PA |
3815 | m_fd, m_ptid.pid (), m_ptid.lwp ()); |
3816 | close (m_fd); | |
05c06f31 | 3817 | } |
05c06f31 | 3818 | |
8a89ddbd PA |
3819 | DISABLE_COPY_AND_ASSIGN (proc_mem_file); |
3820 | ||
3821 | int fd () | |
3822 | { | |
3823 | return m_fd; | |
3824 | } | |
3825 | ||
3826 | private: | |
3827 | /* The LWP this file was opened for. Just for debugging | |
3828 | purposes. */ | |
3829 | ptid_t m_ptid; | |
3830 | ||
3831 | /* The file descriptor. */ | |
3832 | int m_fd = -1; | |
3833 | }; | |
3834 | ||
3835 | /* The map between an inferior process id, and the open /proc/PID/mem | |
3836 | file. This is stored in a map instead of in a per-inferior | |
3837 | structure because we need to be able to access memory of processes | |
3838 | which don't have a corresponding struct inferior object. E.g., | |
3839 | with "detach-on-fork on" (the default), and "follow-fork parent" | |
3840 | (also default), we don't create an inferior for the fork child, but | |
3841 | we still need to remove breakpoints from the fork child's | |
3842 | memory. */ | |
3843 | static std::unordered_map<int, proc_mem_file> proc_mem_file_map; | |
3844 | ||
3845 | /* Close the /proc/PID/mem file for PID. */ | |
05c06f31 PA |
3846 | |
3847 | static void | |
8a89ddbd | 3848 | close_proc_mem_file (pid_t pid) |
dba24537 | 3849 | { |
8a89ddbd | 3850 | proc_mem_file_map.erase (pid); |
05c06f31 | 3851 | } |
dba24537 | 3852 | |
8a89ddbd PA |
3853 | /* Open the /proc/PID/mem file for the process (thread group) of PTID. |
3854 | We actually open /proc/PID/task/LWP/mem, as that's the LWP we know | |
3855 | exists and is stopped right now. We prefer the | |
3856 | /proc/PID/task/LWP/mem form over /proc/LWP/mem to avoid tid-reuse | |
3857 | races, just in case this is ever called on an already-waited | |
3858 | LWP. */ | |
dba24537 | 3859 | |
8a89ddbd PA |
3860 | static void |
3861 | open_proc_mem_file (ptid_t ptid) | |
05c06f31 | 3862 | { |
8a89ddbd PA |
3863 | auto iter = proc_mem_file_map.find (ptid.pid ()); |
3864 | gdb_assert (iter == proc_mem_file_map.end ()); | |
dba24537 | 3865 | |
8a89ddbd PA |
3866 | char filename[64]; |
3867 | xsnprintf (filename, sizeof filename, | |
3868 | "/proc/%d/task/%ld/mem", ptid.pid (), ptid.lwp ()); | |
3869 | ||
3870 | int fd = gdb_open_cloexec (filename, O_RDWR | O_LARGEFILE, 0).release (); | |
05c06f31 | 3871 | |
8a89ddbd PA |
3872 | if (fd == -1) |
3873 | { | |
3874 | warning (_("opening /proc/PID/mem file for lwp %d.%ld failed: %s (%d)"), | |
3875 | ptid.pid (), ptid.lwp (), | |
3876 | safe_strerror (errno), errno); | |
3877 | return; | |
05c06f31 PA |
3878 | } |
3879 | ||
8a89ddbd PA |
3880 | proc_mem_file_map.emplace (std::piecewise_construct, |
3881 | std::forward_as_tuple (ptid.pid ()), | |
3882 | std::forward_as_tuple (ptid, fd)); | |
3883 | ||
9221923c | 3884 | linux_nat_debug_printf ("opened fd %d for lwp %d.%ld", |
8a89ddbd PA |
3885 | fd, ptid.pid (), ptid.lwp ()); |
3886 | } | |
3887 | ||
1bcb0708 PA |
3888 | /* Helper for linux_proc_xfer_memory_partial and |
3889 | proc_mem_file_is_writable. FD is the already opened /proc/pid/mem | |
3890 | file, and PID is the pid of the corresponding process. The rest of | |
3891 | the arguments are like linux_proc_xfer_memory_partial's. */ | |
8a89ddbd PA |
3892 | |
3893 | static enum target_xfer_status | |
1bcb0708 PA |
3894 | linux_proc_xfer_memory_partial_fd (int fd, int pid, |
3895 | gdb_byte *readbuf, const gdb_byte *writebuf, | |
3896 | ULONGEST offset, LONGEST len, | |
3897 | ULONGEST *xfered_len) | |
8a89ddbd PA |
3898 | { |
3899 | ssize_t ret; | |
3900 | ||
8a89ddbd | 3901 | gdb_assert (fd != -1); |
dba24537 | 3902 | |
a379284a AA |
3903 | /* Use pread64/pwrite64 if available, since they save a syscall and can |
3904 | handle 64-bit offsets even on 32-bit platforms (for instance, SPARC | |
3905 | debugging a SPARC64 application). */ | |
dba24537 | 3906 | #ifdef HAVE_PREAD64 |
a379284a AA |
3907 | ret = (readbuf ? pread64 (fd, readbuf, len, offset) |
3908 | : pwrite64 (fd, writebuf, len, offset)); | |
dba24537 | 3909 | #else |
a379284a AA |
3910 | ret = lseek (fd, offset, SEEK_SET); |
3911 | if (ret != -1) | |
3912 | ret = (readbuf ? read (fd, readbuf, len) | |
3913 | : write (fd, writebuf, len)); | |
dba24537 | 3914 | #endif |
dba24537 | 3915 | |
05c06f31 PA |
3916 | if (ret == -1) |
3917 | { | |
9221923c | 3918 | linux_nat_debug_printf ("accessing fd %d for pid %d failed: %s (%d)", |
1bcb0708 | 3919 | fd, pid, safe_strerror (errno), errno); |
284b6bb5 | 3920 | return TARGET_XFER_E_IO; |
05c06f31 PA |
3921 | } |
3922 | else if (ret == 0) | |
3923 | { | |
8a89ddbd PA |
3924 | /* EOF means the address space is gone, the whole process exited |
3925 | or execed. */ | |
9221923c | 3926 | linux_nat_debug_printf ("accessing fd %d for pid %d got EOF", |
1bcb0708 | 3927 | fd, pid); |
05c06f31 PA |
3928 | return TARGET_XFER_EOF; |
3929 | } | |
9b409511 YQ |
3930 | else |
3931 | { | |
8a89ddbd | 3932 | *xfered_len = ret; |
9b409511 YQ |
3933 | return TARGET_XFER_OK; |
3934 | } | |
05c06f31 | 3935 | } |
efcbbd14 | 3936 | |
1bcb0708 PA |
3937 | /* Implement the to_xfer_partial target method using /proc/PID/mem. |
3938 | Because we can use a single read/write call, this can be much more | |
3939 | efficient than banging away at PTRACE_PEEKTEXT. Also, unlike | |
3940 | PTRACE_PEEKTEXT/PTRACE_POKETEXT, this works with running | |
3941 | threads. */ | |
3942 | ||
3943 | static enum target_xfer_status | |
3944 | linux_proc_xfer_memory_partial (gdb_byte *readbuf, const gdb_byte *writebuf, | |
3945 | ULONGEST offset, LONGEST len, | |
3946 | ULONGEST *xfered_len) | |
3947 | { | |
3948 | int pid = inferior_ptid.pid (); | |
3949 | ||
3950 | auto iter = proc_mem_file_map.find (pid); | |
3951 | if (iter == proc_mem_file_map.end ()) | |
3952 | return TARGET_XFER_EOF; | |
3953 | ||
3954 | int fd = iter->second.fd (); | |
3955 | ||
3956 | return linux_proc_xfer_memory_partial_fd (fd, pid, readbuf, writebuf, offset, | |
3957 | len, xfered_len); | |
3958 | } | |
3959 | ||
3960 | /* Check whether /proc/pid/mem is writable in the current kernel, and | |
3961 | return true if so. It wasn't writable before Linux 2.6.39, but | |
3962 | there's no way to know whether the feature was backported to older | |
3963 | kernels. So we check to see if it works. The result is cached, | |
3964 | and this is garanteed to be called once early at startup. */ | |
3965 | ||
3966 | static bool | |
3967 | proc_mem_file_is_writable () | |
3968 | { | |
3969 | static gdb::optional<bool> writable; | |
3970 | ||
3971 | if (writable.has_value ()) | |
3972 | return *writable; | |
3973 | ||
3974 | writable.emplace (false); | |
3975 | ||
3976 | /* We check whether /proc/pid/mem is writable by trying to write to | |
3977 | one of our variables via /proc/self/mem. */ | |
3978 | ||
3979 | int fd = gdb_open_cloexec ("/proc/self/mem", O_RDWR | O_LARGEFILE, 0).release (); | |
3980 | ||
3981 | if (fd == -1) | |
3982 | { | |
3983 | warning (_("opening /proc/self/mem file failed: %s (%d)"), | |
3984 | safe_strerror (errno), errno); | |
3985 | return *writable; | |
3986 | } | |
3987 | ||
3988 | SCOPE_EXIT { close (fd); }; | |
3989 | ||
3990 | /* This is the variable we try to write to. Note OFFSET below. */ | |
3991 | volatile gdb_byte test_var = 0; | |
3992 | ||
3993 | gdb_byte writebuf[] = {0x55}; | |
3994 | ULONGEST offset = (uintptr_t) &test_var; | |
3995 | ULONGEST xfered_len; | |
3996 | ||
3997 | enum target_xfer_status res | |
3998 | = linux_proc_xfer_memory_partial_fd (fd, getpid (), nullptr, writebuf, | |
3999 | offset, 1, &xfered_len); | |
4000 | ||
4001 | if (res == TARGET_XFER_OK) | |
4002 | { | |
4003 | gdb_assert (xfered_len == 1); | |
4004 | gdb_assert (test_var == 0x55); | |
4005 | /* Success. */ | |
4006 | *writable = true; | |
4007 | } | |
4008 | ||
4009 | return *writable; | |
4010 | } | |
4011 | ||
dba24537 AC |
4012 | /* Parse LINE as a signal set and add its set bits to SIGS. */ |
4013 | ||
4014 | static void | |
4015 | add_line_to_sigset (const char *line, sigset_t *sigs) | |
4016 | { | |
4017 | int len = strlen (line) - 1; | |
4018 | const char *p; | |
4019 | int signum; | |
4020 | ||
4021 | if (line[len] != '\n') | |
8a3fe4f8 | 4022 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4023 | |
4024 | p = line; | |
4025 | signum = len * 4; | |
4026 | while (len-- > 0) | |
4027 | { | |
4028 | int digit; | |
4029 | ||
4030 | if (*p >= '0' && *p <= '9') | |
4031 | digit = *p - '0'; | |
4032 | else if (*p >= 'a' && *p <= 'f') | |
4033 | digit = *p - 'a' + 10; | |
4034 | else | |
8a3fe4f8 | 4035 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4036 | |
4037 | signum -= 4; | |
4038 | ||
4039 | if (digit & 1) | |
4040 | sigaddset (sigs, signum + 1); | |
4041 | if (digit & 2) | |
4042 | sigaddset (sigs, signum + 2); | |
4043 | if (digit & 4) | |
4044 | sigaddset (sigs, signum + 3); | |
4045 | if (digit & 8) | |
4046 | sigaddset (sigs, signum + 4); | |
4047 | ||
4048 | p++; | |
4049 | } | |
4050 | } | |
4051 | ||
4052 | /* Find process PID's pending signals from /proc/pid/status and set | |
4053 | SIGS to match. */ | |
4054 | ||
4055 | void | |
3e43a32a MS |
4056 | linux_proc_pending_signals (int pid, sigset_t *pending, |
4057 | sigset_t *blocked, sigset_t *ignored) | |
dba24537 | 4058 | { |
d8d2a3ee | 4059 | char buffer[PATH_MAX], fname[PATH_MAX]; |
dba24537 AC |
4060 | |
4061 | sigemptyset (pending); | |
4062 | sigemptyset (blocked); | |
4063 | sigemptyset (ignored); | |
cde33bf1 | 4064 | xsnprintf (fname, sizeof fname, "/proc/%d/status", pid); |
d419f42d | 4065 | gdb_file_up procfile = gdb_fopen_cloexec (fname, "r"); |
dba24537 | 4066 | if (procfile == NULL) |
8a3fe4f8 | 4067 | error (_("Could not open %s"), fname); |
dba24537 | 4068 | |
d419f42d | 4069 | while (fgets (buffer, PATH_MAX, procfile.get ()) != NULL) |
dba24537 AC |
4070 | { |
4071 | /* Normal queued signals are on the SigPnd line in the status | |
4072 | file. However, 2.6 kernels also have a "shared" pending | |
4073 | queue for delivering signals to a thread group, so check for | |
4074 | a ShdPnd line also. | |
4075 | ||
4076 | Unfortunately some Red Hat kernels include the shared pending | |
4077 | queue but not the ShdPnd status field. */ | |
4078 | ||
61012eef | 4079 | if (startswith (buffer, "SigPnd:\t")) |
dba24537 | 4080 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4081 | else if (startswith (buffer, "ShdPnd:\t")) |
dba24537 | 4082 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4083 | else if (startswith (buffer, "SigBlk:\t")) |
dba24537 | 4084 | add_line_to_sigset (buffer + 8, blocked); |
61012eef | 4085 | else if (startswith (buffer, "SigIgn:\t")) |
dba24537 AC |
4086 | add_line_to_sigset (buffer + 8, ignored); |
4087 | } | |
dba24537 AC |
4088 | } |
4089 | ||
9b409511 | 4090 | static enum target_xfer_status |
f6ac5f3d | 4091 | linux_nat_xfer_osdata (enum target_object object, |
e0881a8e | 4092 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
4093 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
4094 | ULONGEST *xfered_len) | |
07e059b5 | 4095 | { |
07e059b5 VP |
4096 | gdb_assert (object == TARGET_OBJECT_OSDATA); |
4097 | ||
9b409511 YQ |
4098 | *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len); |
4099 | if (*xfered_len == 0) | |
4100 | return TARGET_XFER_EOF; | |
4101 | else | |
4102 | return TARGET_XFER_OK; | |
07e059b5 VP |
4103 | } |
4104 | ||
f6ac5f3d PA |
4105 | std::vector<static_tracepoint_marker> |
4106 | linux_nat_target::static_tracepoint_markers_by_strid (const char *strid) | |
5808517f YQ |
4107 | { |
4108 | char s[IPA_CMD_BUF_SIZE]; | |
e99b03dc | 4109 | int pid = inferior_ptid.pid (); |
5d9310c4 | 4110 | std::vector<static_tracepoint_marker> markers; |
256642e8 | 4111 | const char *p = s; |
184ea2f7 | 4112 | ptid_t ptid = ptid_t (pid, 0); |
5d9310c4 | 4113 | static_tracepoint_marker marker; |
5808517f YQ |
4114 | |
4115 | /* Pause all */ | |
4116 | target_stop (ptid); | |
4117 | ||
4118 | memcpy (s, "qTfSTM", sizeof ("qTfSTM")); | |
4119 | s[sizeof ("qTfSTM")] = 0; | |
4120 | ||
42476b70 | 4121 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f | 4122 | |
1db93f14 TT |
4123 | /* Unpause all. */ |
4124 | SCOPE_EXIT { target_continue_no_signal (ptid); }; | |
5808517f YQ |
4125 | |
4126 | while (*p++ == 'm') | |
4127 | { | |
5808517f YQ |
4128 | do |
4129 | { | |
5d9310c4 | 4130 | parse_static_tracepoint_marker_definition (p, &p, &marker); |
5808517f | 4131 | |
5d9310c4 SM |
4132 | if (strid == NULL || marker.str_id == strid) |
4133 | markers.push_back (std::move (marker)); | |
5808517f YQ |
4134 | } |
4135 | while (*p++ == ','); /* comma-separated list */ | |
4136 | ||
4137 | memcpy (s, "qTsSTM", sizeof ("qTsSTM")); | |
4138 | s[sizeof ("qTsSTM")] = 0; | |
42476b70 | 4139 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4140 | p = s; |
4141 | } | |
4142 | ||
5808517f YQ |
4143 | return markers; |
4144 | } | |
4145 | ||
b84876c2 PA |
4146 | /* target_can_async_p implementation. */ |
4147 | ||
57810aa7 | 4148 | bool |
f6ac5f3d | 4149 | linux_nat_target::can_async_p () |
b84876c2 | 4150 | { |
fce6cd34 AB |
4151 | /* This flag should be checked in the common target.c code. */ |
4152 | gdb_assert (target_async_permitted); | |
4153 | ||
4154 | /* Otherwise, this targets is always able to support async mode. */ | |
4155 | return true; | |
b84876c2 PA |
4156 | } |
4157 | ||
57810aa7 | 4158 | bool |
f6ac5f3d | 4159 | linux_nat_target::supports_non_stop () |
9908b566 | 4160 | { |
f80c8ec4 | 4161 | return true; |
9908b566 VP |
4162 | } |
4163 | ||
fbea99ea PA |
4164 | /* to_always_non_stop_p implementation. */ |
4165 | ||
57810aa7 | 4166 | bool |
f6ac5f3d | 4167 | linux_nat_target::always_non_stop_p () |
fbea99ea | 4168 | { |
f80c8ec4 | 4169 | return true; |
fbea99ea PA |
4170 | } |
4171 | ||
57810aa7 | 4172 | bool |
f6ac5f3d | 4173 | linux_nat_target::supports_multi_process () |
d90e17a7 | 4174 | { |
aee91db3 | 4175 | return true; |
d90e17a7 PA |
4176 | } |
4177 | ||
57810aa7 | 4178 | bool |
f6ac5f3d | 4179 | linux_nat_target::supports_disable_randomization () |
03583c20 | 4180 | { |
f80c8ec4 | 4181 | return true; |
03583c20 UW |
4182 | } |
4183 | ||
7feb7d06 PA |
4184 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
4185 | so we notice when any child changes state, and notify the | |
4186 | event-loop; it allows us to use sigsuspend in linux_nat_wait_1 | |
4187 | above to wait for the arrival of a SIGCHLD. */ | |
4188 | ||
b84876c2 | 4189 | static void |
7feb7d06 | 4190 | sigchld_handler (int signo) |
b84876c2 | 4191 | { |
7feb7d06 PA |
4192 | int old_errno = errno; |
4193 | ||
01124a23 | 4194 | if (debug_linux_nat) |
da5bd37e | 4195 | gdb_stdlog->write_async_safe ("sigchld\n", sizeof ("sigchld\n") - 1); |
7feb7d06 | 4196 | |
b146ba14 JB |
4197 | if (signo == SIGCHLD) |
4198 | { | |
4199 | /* Let the event loop know that there are events to handle. */ | |
4200 | linux_nat_target::async_file_mark_if_open (); | |
4201 | } | |
7feb7d06 PA |
4202 | |
4203 | errno = old_errno; | |
4204 | } | |
4205 | ||
4206 | /* Callback registered with the target events file descriptor. */ | |
4207 | ||
4208 | static void | |
4209 | handle_target_event (int error, gdb_client_data client_data) | |
4210 | { | |
b1a35af2 | 4211 | inferior_event_handler (INF_REG_EVENT); |
7feb7d06 PA |
4212 | } |
4213 | ||
b84876c2 PA |
4214 | /* target_async implementation. */ |
4215 | ||
f6ac5f3d | 4216 | void |
4a570176 | 4217 | linux_nat_target::async (bool enable) |
b84876c2 | 4218 | { |
4a570176 | 4219 | if (enable == is_async_p ()) |
b146ba14 JB |
4220 | return; |
4221 | ||
4222 | /* Block child signals while we create/destroy the pipe, as their | |
4223 | handler writes to it. */ | |
4224 | gdb::block_signals blocker; | |
4225 | ||
6a3753b3 | 4226 | if (enable) |
b84876c2 | 4227 | { |
b146ba14 | 4228 | if (!async_file_open ()) |
f34652de | 4229 | internal_error ("creating event pipe failed."); |
b146ba14 JB |
4230 | |
4231 | add_file_handler (async_wait_fd (), handle_target_event, NULL, | |
4232 | "linux-nat"); | |
4233 | ||
4234 | /* There may be pending events to handle. Tell the event loop | |
4235 | to poll them. */ | |
4236 | async_file_mark (); | |
b84876c2 PA |
4237 | } |
4238 | else | |
4239 | { | |
b146ba14 JB |
4240 | delete_file_handler (async_wait_fd ()); |
4241 | async_file_close (); | |
b84876c2 | 4242 | } |
b84876c2 PA |
4243 | } |
4244 | ||
a493e3e2 | 4245 | /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other |
252fbfc8 PA |
4246 | event came out. */ |
4247 | ||
4c28f408 | 4248 | static int |
d3a70e03 | 4249 | linux_nat_stop_lwp (struct lwp_info *lwp) |
4c28f408 | 4250 | { |
d90e17a7 | 4251 | if (!lwp->stopped) |
252fbfc8 | 4252 | { |
9327494e | 4253 | linux_nat_debug_printf ("running -> suspending %s", |
e53c95d4 | 4254 | lwp->ptid.to_string ().c_str ()); |
252fbfc8 | 4255 | |
252fbfc8 | 4256 | |
25289eb2 PA |
4257 | if (lwp->last_resume_kind == resume_stop) |
4258 | { | |
9327494e SM |
4259 | linux_nat_debug_printf ("already stopping LWP %ld at GDB's request", |
4260 | lwp->ptid.lwp ()); | |
25289eb2 PA |
4261 | return 0; |
4262 | } | |
252fbfc8 | 4263 | |
d3a70e03 | 4264 | stop_callback (lwp); |
25289eb2 | 4265 | lwp->last_resume_kind = resume_stop; |
d90e17a7 PA |
4266 | } |
4267 | else | |
4268 | { | |
4269 | /* Already known to be stopped; do nothing. */ | |
252fbfc8 | 4270 | |
d90e17a7 PA |
4271 | if (debug_linux_nat) |
4272 | { | |
5b6d1e4f | 4273 | if (find_thread_ptid (linux_target, lwp->ptid)->stop_requested) |
9327494e | 4274 | linux_nat_debug_printf ("already stopped/stop_requested %s", |
e53c95d4 | 4275 | lwp->ptid.to_string ().c_str ()); |
d90e17a7 | 4276 | else |
9327494e | 4277 | linux_nat_debug_printf ("already stopped/no stop_requested yet %s", |
e53c95d4 | 4278 | lwp->ptid.to_string ().c_str ()); |
252fbfc8 PA |
4279 | } |
4280 | } | |
4c28f408 PA |
4281 | return 0; |
4282 | } | |
4283 | ||
f6ac5f3d PA |
4284 | void |
4285 | linux_nat_target::stop (ptid_t ptid) | |
4c28f408 | 4286 | { |
b6e52a0b | 4287 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
d3a70e03 | 4288 | iterate_over_lwps (ptid, linux_nat_stop_lwp); |
bfedc46a PA |
4289 | } |
4290 | ||
c0694254 PA |
4291 | /* When requests are passed down from the linux-nat layer to the |
4292 | single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are | |
4293 | used. The address space pointer is stored in the inferior object, | |
4294 | but the common code that is passed such ptid can't tell whether | |
4295 | lwpid is a "main" process id or not (it assumes so). We reverse | |
4296 | look up the "main" process id from the lwp here. */ | |
4297 | ||
f6ac5f3d PA |
4298 | struct address_space * |
4299 | linux_nat_target::thread_address_space (ptid_t ptid) | |
c0694254 PA |
4300 | { |
4301 | struct lwp_info *lwp; | |
4302 | struct inferior *inf; | |
4303 | int pid; | |
4304 | ||
e38504b3 | 4305 | if (ptid.lwp () == 0) |
c0694254 PA |
4306 | { |
4307 | /* An (lwpid,0,0) ptid. Look up the lwp object to get at the | |
4308 | tgid. */ | |
4309 | lwp = find_lwp_pid (ptid); | |
e99b03dc | 4310 | pid = lwp->ptid.pid (); |
c0694254 PA |
4311 | } |
4312 | else | |
4313 | { | |
4314 | /* A (pid,lwpid,0) ptid. */ | |
e99b03dc | 4315 | pid = ptid.pid (); |
c0694254 PA |
4316 | } |
4317 | ||
5b6d1e4f | 4318 | inf = find_inferior_pid (this, pid); |
c0694254 PA |
4319 | gdb_assert (inf != NULL); |
4320 | return inf->aspace; | |
4321 | } | |
4322 | ||
dc146f7c VP |
4323 | /* Return the cached value of the processor core for thread PTID. */ |
4324 | ||
f6ac5f3d PA |
4325 | int |
4326 | linux_nat_target::core_of_thread (ptid_t ptid) | |
dc146f7c VP |
4327 | { |
4328 | struct lwp_info *info = find_lwp_pid (ptid); | |
e0881a8e | 4329 | |
dc146f7c VP |
4330 | if (info) |
4331 | return info->core; | |
4332 | return -1; | |
4333 | } | |
4334 | ||
7a6a1731 GB |
4335 | /* Implementation of to_filesystem_is_local. */ |
4336 | ||
57810aa7 | 4337 | bool |
f6ac5f3d | 4338 | linux_nat_target::filesystem_is_local () |
7a6a1731 GB |
4339 | { |
4340 | struct inferior *inf = current_inferior (); | |
4341 | ||
4342 | if (inf->fake_pid_p || inf->pid == 0) | |
57810aa7 | 4343 | return true; |
7a6a1731 GB |
4344 | |
4345 | return linux_ns_same (inf->pid, LINUX_NS_MNT); | |
4346 | } | |
4347 | ||
4348 | /* Convert the INF argument passed to a to_fileio_* method | |
4349 | to a process ID suitable for passing to its corresponding | |
4350 | linux_mntns_* function. If INF is non-NULL then the | |
4351 | caller is requesting the filesystem seen by INF. If INF | |
4352 | is NULL then the caller is requesting the filesystem seen | |
4353 | by the GDB. We fall back to GDB's filesystem in the case | |
4354 | that INF is non-NULL but its PID is unknown. */ | |
4355 | ||
4356 | static pid_t | |
4357 | linux_nat_fileio_pid_of (struct inferior *inf) | |
4358 | { | |
4359 | if (inf == NULL || inf->fake_pid_p || inf->pid == 0) | |
4360 | return getpid (); | |
4361 | else | |
4362 | return inf->pid; | |
4363 | } | |
4364 | ||
4365 | /* Implementation of to_fileio_open. */ | |
4366 | ||
f6ac5f3d PA |
4367 | int |
4368 | linux_nat_target::fileio_open (struct inferior *inf, const char *filename, | |
4369 | int flags, int mode, int warn_if_slow, | |
b872057a | 4370 | fileio_error *target_errno) |
7a6a1731 GB |
4371 | { |
4372 | int nat_flags; | |
4373 | mode_t nat_mode; | |
4374 | int fd; | |
4375 | ||
4376 | if (fileio_to_host_openflags (flags, &nat_flags) == -1 | |
4377 | || fileio_to_host_mode (mode, &nat_mode) == -1) | |
4378 | { | |
4379 | *target_errno = FILEIO_EINVAL; | |
4380 | return -1; | |
4381 | } | |
4382 | ||
4383 | fd = linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf), | |
4384 | filename, nat_flags, nat_mode); | |
4385 | if (fd == -1) | |
4386 | *target_errno = host_to_fileio_error (errno); | |
4387 | ||
4388 | return fd; | |
4389 | } | |
4390 | ||
4391 | /* Implementation of to_fileio_readlink. */ | |
4392 | ||
f6ac5f3d PA |
4393 | gdb::optional<std::string> |
4394 | linux_nat_target::fileio_readlink (struct inferior *inf, const char *filename, | |
b872057a | 4395 | fileio_error *target_errno) |
7a6a1731 GB |
4396 | { |
4397 | char buf[PATH_MAX]; | |
4398 | int len; | |
7a6a1731 GB |
4399 | |
4400 | len = linux_mntns_readlink (linux_nat_fileio_pid_of (inf), | |
4401 | filename, buf, sizeof (buf)); | |
4402 | if (len < 0) | |
4403 | { | |
4404 | *target_errno = host_to_fileio_error (errno); | |
e0d3522b | 4405 | return {}; |
7a6a1731 GB |
4406 | } |
4407 | ||
e0d3522b | 4408 | return std::string (buf, len); |
7a6a1731 GB |
4409 | } |
4410 | ||
4411 | /* Implementation of to_fileio_unlink. */ | |
4412 | ||
f6ac5f3d PA |
4413 | int |
4414 | linux_nat_target::fileio_unlink (struct inferior *inf, const char *filename, | |
b872057a | 4415 | fileio_error *target_errno) |
7a6a1731 GB |
4416 | { |
4417 | int ret; | |
4418 | ||
4419 | ret = linux_mntns_unlink (linux_nat_fileio_pid_of (inf), | |
4420 | filename); | |
4421 | if (ret == -1) | |
4422 | *target_errno = host_to_fileio_error (errno); | |
4423 | ||
4424 | return ret; | |
4425 | } | |
4426 | ||
aa01bd36 PA |
4427 | /* Implementation of the to_thread_events method. */ |
4428 | ||
f6ac5f3d PA |
4429 | void |
4430 | linux_nat_target::thread_events (int enable) | |
aa01bd36 PA |
4431 | { |
4432 | report_thread_events = enable; | |
4433 | } | |
4434 | ||
f6ac5f3d PA |
4435 | linux_nat_target::linux_nat_target () |
4436 | { | |
f973ed9c DJ |
4437 | /* We don't change the stratum; this target will sit at |
4438 | process_stratum and thread_db will set at thread_stratum. This | |
4439 | is a little strange, since this is a multi-threaded-capable | |
4440 | target, but we want to be on the stack below thread_db, and we | |
4441 | also want to be used for single-threaded processes. */ | |
f973ed9c DJ |
4442 | } |
4443 | ||
f865ee35 JK |
4444 | /* See linux-nat.h. */ |
4445 | ||
4446 | int | |
4447 | linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo) | |
9f0bdab8 | 4448 | { |
da559b09 | 4449 | int pid; |
9f0bdab8 | 4450 | |
e38504b3 | 4451 | pid = ptid.lwp (); |
da559b09 | 4452 | if (pid == 0) |
e99b03dc | 4453 | pid = ptid.pid (); |
f865ee35 | 4454 | |
da559b09 JK |
4455 | errno = 0; |
4456 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo); | |
4457 | if (errno != 0) | |
4458 | { | |
4459 | memset (siginfo, 0, sizeof (*siginfo)); | |
4460 | return 0; | |
4461 | } | |
f865ee35 | 4462 | return 1; |
9f0bdab8 DJ |
4463 | } |
4464 | ||
7b669087 GB |
4465 | /* See nat/linux-nat.h. */ |
4466 | ||
4467 | ptid_t | |
4468 | current_lwp_ptid (void) | |
4469 | { | |
15a9e13e | 4470 | gdb_assert (inferior_ptid.lwp_p ()); |
7b669087 GB |
4471 | return inferior_ptid; |
4472 | } | |
4473 | ||
6c265988 | 4474 | void _initialize_linux_nat (); |
d6b0e80f | 4475 | void |
6c265988 | 4476 | _initialize_linux_nat () |
d6b0e80f | 4477 | { |
8864ef42 | 4478 | add_setshow_boolean_cmd ("linux-nat", class_maintenance, |
b6e52a0b AB |
4479 | &debug_linux_nat, _("\ |
4480 | Set debugging of GNU/Linux native target."), _(" \ | |
4481 | Show debugging of GNU/Linux native target."), _(" \ | |
4482 | When on, print debug messages relating to the GNU/Linux native target."), | |
4483 | nullptr, | |
4484 | show_debug_linux_nat, | |
4485 | &setdebuglist, &showdebuglist); | |
b84876c2 | 4486 | |
7a6a1731 GB |
4487 | add_setshow_boolean_cmd ("linux-namespaces", class_maintenance, |
4488 | &debug_linux_namespaces, _("\ | |
4489 | Set debugging of GNU/Linux namespaces module."), _("\ | |
4490 | Show debugging of GNU/Linux namespaces module."), _("\ | |
4491 | Enables printf debugging output."), | |
4492 | NULL, | |
4493 | NULL, | |
4494 | &setdebuglist, &showdebuglist); | |
4495 | ||
7feb7d06 PA |
4496 | /* Install a SIGCHLD handler. */ |
4497 | sigchld_action.sa_handler = sigchld_handler; | |
4498 | sigemptyset (&sigchld_action.sa_mask); | |
4499 | sigchld_action.sa_flags = SA_RESTART; | |
b84876c2 PA |
4500 | |
4501 | /* Make it the default. */ | |
7feb7d06 | 4502 | sigaction (SIGCHLD, &sigchld_action, NULL); |
d6b0e80f AC |
4503 | |
4504 | /* Make sure we don't block SIGCHLD during a sigsuspend. */ | |
21987b9c | 4505 | gdb_sigmask (SIG_SETMASK, NULL, &suspend_mask); |
d6b0e80f AC |
4506 | sigdelset (&suspend_mask, SIGCHLD); |
4507 | ||
7feb7d06 | 4508 | sigemptyset (&blocked_mask); |
774113b0 PA |
4509 | |
4510 | lwp_lwpid_htab_create (); | |
1bcb0708 PA |
4511 | |
4512 | proc_mem_file_is_writable (); | |
d6b0e80f AC |
4513 | } |
4514 | \f | |
4515 | ||
4516 | /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to | |
4517 | the GNU/Linux Threads library and therefore doesn't really belong | |
4518 | here. */ | |
4519 | ||
089436f7 TV |
4520 | /* NPTL reserves the first two RT signals, but does not provide any |
4521 | way for the debugger to query the signal numbers - fortunately | |
4522 | they don't change. */ | |
4523 | static int lin_thread_signals[] = { __SIGRTMIN, __SIGRTMIN + 1 }; | |
d6b0e80f | 4524 | |
089436f7 TV |
4525 | /* See linux-nat.h. */ |
4526 | ||
4527 | unsigned int | |
4528 | lin_thread_get_thread_signal_num (void) | |
d6b0e80f | 4529 | { |
089436f7 TV |
4530 | return sizeof (lin_thread_signals) / sizeof (lin_thread_signals[0]); |
4531 | } | |
d6b0e80f | 4532 | |
089436f7 TV |
4533 | /* See linux-nat.h. */ |
4534 | ||
4535 | int | |
4536 | lin_thread_get_thread_signal (unsigned int i) | |
4537 | { | |
4538 | gdb_assert (i < lin_thread_get_thread_signal_num ()); | |
4539 | return lin_thread_signals[i]; | |
d6b0e80f | 4540 | } |