Clean up trailing white space
[deliverable/binutils-gdb.git] / gdb / linux-nat.c
1 /* GNU/Linux native-dependent code common to multiple platforms.
2
3 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
4 2011 Free Software Foundation, Inc.
5
6 This file is part of GDB.
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
20
21 #include "defs.h"
22 #include "inferior.h"
23 #include "target.h"
24 #include "gdb_string.h"
25 #include "gdb_wait.h"
26 #include "gdb_assert.h"
27 #ifdef HAVE_TKILL_SYSCALL
28 #include <unistd.h>
29 #include <sys/syscall.h>
30 #endif
31 #include <sys/ptrace.h>
32 #include "linux-nat.h"
33 #include "linux-ptrace.h"
34 #include "linux-fork.h"
35 #include "gdbthread.h"
36 #include "gdbcmd.h"
37 #include "regcache.h"
38 #include "regset.h"
39 #include "inf-ptrace.h"
40 #include "auxv.h"
41 #include <sys/param.h> /* for MAXPATHLEN */
42 #include <sys/procfs.h> /* for elf_gregset etc. */
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 */
47 #include "gdbthread.h" /* for struct thread_info etc. */
48 #include "gdb_stat.h" /* for struct stat */
49 #include <fcntl.h> /* for O_RDONLY */
50 #include "inf-loop.h"
51 #include "event-loop.h"
52 #include "event-top.h"
53 #include <pwd.h>
54 #include <sys/types.h>
55 #include "gdb_dirent.h"
56 #include "xml-support.h"
57 #include "terminal.h"
58 #include <sys/vfs.h>
59 #include "solib.h"
60 #include "linux-osdata.h"
61
62 #ifndef SPUFS_MAGIC
63 #define SPUFS_MAGIC 0x23c9b64e
64 #endif
65
66 #ifdef HAVE_PERSONALITY
67 # include <sys/personality.h>
68 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
69 # define ADDR_NO_RANDOMIZE 0x0040000
70 # endif
71 #endif /* HAVE_PERSONALITY */
72
73 /* This comment documents high-level logic of this file.
74
75 Waiting for events in sync mode
76 ===============================
77
78 When waiting for an event in a specific thread, we just use waitpid, passing
79 the specific pid, and not passing WNOHANG.
80
81 When waiting for an event in all threads, waitpid is not quite good. Prior to
82 version 2.4, Linux can either wait for event in main thread, or in secondary
83 threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might
84 miss an event. The solution is to use non-blocking waitpid, together with
85 sigsuspend. First, we use non-blocking waitpid to get an event in the main
86 process, if any. Second, we use non-blocking waitpid with the __WCLONED
87 flag to check for events in cloned processes. If nothing is found, we use
88 sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something
89 happened to a child process -- and SIGCHLD will be delivered both for events
90 in main debugged process and in cloned processes. As soon as we know there's
91 an event, we get back to calling nonblocking waitpid with and without
92 __WCLONED.
93
94 Note that SIGCHLD should be blocked between waitpid and sigsuspend calls,
95 so that we don't miss a signal. If SIGCHLD arrives in between, when it's
96 blocked, the signal becomes pending and sigsuspend immediately
97 notices it and returns.
98
99 Waiting for events in async mode
100 ================================
101
102 In async mode, GDB should always be ready to handle both user input
103 and target events, so neither blocking waitpid nor sigsuspend are
104 viable options. Instead, we should asynchronously notify the GDB main
105 event loop whenever there's an unprocessed event from the target. We
106 detect asynchronous target events by handling SIGCHLD signals. To
107 notify the event loop about target events, the self-pipe trick is used
108 --- a pipe is registered as waitable event source in the event loop,
109 the event loop select/poll's on the read end of this pipe (as well on
110 other event sources, e.g., stdin), and the SIGCHLD handler writes a
111 byte to this pipe. This is more portable than relying on
112 pselect/ppoll, since on kernels that lack those syscalls, libc
113 emulates them with select/poll+sigprocmask, and that is racy
114 (a.k.a. plain broken).
115
116 Obviously, if we fail to notify the event loop if there's a target
117 event, it's bad. OTOH, if we notify the event loop when there's no
118 event from the target, linux_nat_wait will detect that there's no real
119 event to report, and return event of type TARGET_WAITKIND_IGNORE.
120 This is mostly harmless, but it will waste time and is better avoided.
121
122 The main design point is that every time GDB is outside linux-nat.c,
123 we have a SIGCHLD handler installed that is called when something
124 happens to the target and notifies the GDB event loop. Whenever GDB
125 core decides to handle the event, and calls into linux-nat.c, we
126 process things as in sync mode, except that the we never block in
127 sigsuspend.
128
129 While processing an event, we may end up momentarily blocked in
130 waitpid calls. Those waitpid calls, while blocking, are guarantied to
131 return quickly. E.g., in all-stop mode, before reporting to the core
132 that an LWP hit a breakpoint, all LWPs are stopped by sending them
133 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
134 Note that this is different from blocking indefinitely waiting for the
135 next event --- here, we're already handling an event.
136
137 Use of signals
138 ==============
139
140 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
141 signal is not entirely significant; we just need for a signal to be delivered,
142 so that we can intercept it. SIGSTOP's advantage is that it can not be
143 blocked. A disadvantage is that it is not a real-time signal, so it can only
144 be queued once; we do not keep track of other sources of SIGSTOP.
145
146 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
147 use them, because they have special behavior when the signal is generated -
148 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
149 kills the entire thread group.
150
151 A delivered SIGSTOP would stop the entire thread group, not just the thread we
152 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
153 cancel it (by PTRACE_CONT without passing SIGSTOP).
154
155 We could use a real-time signal instead. This would solve those problems; we
156 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
157 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
158 generates it, and there are races with trying to find a signal that is not
159 blocked. */
160
161 #ifndef O_LARGEFILE
162 #define O_LARGEFILE 0
163 #endif
164
165 /* Unlike other extended result codes, WSTOPSIG (status) on
166 PTRACE_O_TRACESYSGOOD syscall events doesn't return SIGTRAP, but
167 instead SIGTRAP with bit 7 set. */
168 #define SYSCALL_SIGTRAP (SIGTRAP | 0x80)
169
170 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
171 the use of the multi-threaded target. */
172 static struct target_ops *linux_ops;
173 static struct target_ops linux_ops_saved;
174
175 /* The method to call, if any, when a new thread is attached. */
176 static void (*linux_nat_new_thread) (ptid_t);
177
178 /* The method to call, if any, when the siginfo object needs to be
179 converted between the layout returned by ptrace, and the layout in
180 the architecture of the inferior. */
181 static int (*linux_nat_siginfo_fixup) (struct siginfo *,
182 gdb_byte *,
183 int);
184
185 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
186 Called by our to_xfer_partial. */
187 static LONGEST (*super_xfer_partial) (struct target_ops *,
188 enum target_object,
189 const char *, gdb_byte *,
190 const gdb_byte *,
191 ULONGEST, LONGEST);
192
193 static int debug_linux_nat;
194 static void
195 show_debug_linux_nat (struct ui_file *file, int from_tty,
196 struct cmd_list_element *c, const char *value)
197 {
198 fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"),
199 value);
200 }
201
202 static int disable_randomization = 1;
203
204 static void
205 show_disable_randomization (struct ui_file *file, int from_tty,
206 struct cmd_list_element *c, const char *value)
207 {
208 #ifdef HAVE_PERSONALITY
209 fprintf_filtered (file,
210 _("Disabling randomization of debuggee's "
211 "virtual address space is %s.\n"),
212 value);
213 #else /* !HAVE_PERSONALITY */
214 fputs_filtered (_("Disabling randomization of debuggee's "
215 "virtual address space is unsupported on\n"
216 "this platform.\n"), file);
217 #endif /* !HAVE_PERSONALITY */
218 }
219
220 static void
221 set_disable_randomization (char *args, int from_tty,
222 struct cmd_list_element *c)
223 {
224 #ifndef HAVE_PERSONALITY
225 error (_("Disabling randomization of debuggee's "
226 "virtual address space is unsupported on\n"
227 "this platform."));
228 #endif /* !HAVE_PERSONALITY */
229 }
230
231 struct simple_pid_list
232 {
233 int pid;
234 int status;
235 struct simple_pid_list *next;
236 };
237 struct simple_pid_list *stopped_pids;
238
239 /* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACEFORK
240 can not be used, 1 if it can. */
241
242 static int linux_supports_tracefork_flag = -1;
243
244 /* This variable is a tri-state flag: -1 for unknown, 0 if
245 PTRACE_O_TRACESYSGOOD can not be used, 1 if it can. */
246
247 static int linux_supports_tracesysgood_flag = -1;
248
249 /* If we have PTRACE_O_TRACEFORK, this flag indicates whether we also have
250 PTRACE_O_TRACEVFORKDONE. */
251
252 static int linux_supports_tracevforkdone_flag = -1;
253
254 /* Stores the current used ptrace() options. */
255 static int current_ptrace_options = 0;
256
257 /* Async mode support. */
258
259 /* The read/write ends of the pipe registered as waitable file in the
260 event loop. */
261 static int linux_nat_event_pipe[2] = { -1, -1 };
262
263 /* Flush the event pipe. */
264
265 static void
266 async_file_flush (void)
267 {
268 int ret;
269 char buf;
270
271 do
272 {
273 ret = read (linux_nat_event_pipe[0], &buf, 1);
274 }
275 while (ret >= 0 || (ret == -1 && errno == EINTR));
276 }
277
278 /* Put something (anything, doesn't matter what, or how much) in event
279 pipe, so that the select/poll in the event-loop realizes we have
280 something to process. */
281
282 static void
283 async_file_mark (void)
284 {
285 int ret;
286
287 /* It doesn't really matter what the pipe contains, as long we end
288 up with something in it. Might as well flush the previous
289 left-overs. */
290 async_file_flush ();
291
292 do
293 {
294 ret = write (linux_nat_event_pipe[1], "+", 1);
295 }
296 while (ret == -1 && errno == EINTR);
297
298 /* Ignore EAGAIN. If the pipe is full, the event loop will already
299 be awakened anyway. */
300 }
301
302 static void linux_nat_async (void (*callback)
303 (enum inferior_event_type event_type,
304 void *context),
305 void *context);
306 static int kill_lwp (int lwpid, int signo);
307
308 static int stop_callback (struct lwp_info *lp, void *data);
309
310 static void block_child_signals (sigset_t *prev_mask);
311 static void restore_child_signals_mask (sigset_t *prev_mask);
312
313 struct lwp_info;
314 static struct lwp_info *add_lwp (ptid_t ptid);
315 static void purge_lwp_list (int pid);
316 static struct lwp_info *find_lwp_pid (ptid_t ptid);
317
318 \f
319 /* Trivial list manipulation functions to keep track of a list of
320 new stopped processes. */
321 static void
322 add_to_pid_list (struct simple_pid_list **listp, int pid, int status)
323 {
324 struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list));
325
326 new_pid->pid = pid;
327 new_pid->status = status;
328 new_pid->next = *listp;
329 *listp = new_pid;
330 }
331
332 static int
333 pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp)
334 {
335 struct simple_pid_list **p;
336
337 for (p = listp; *p != NULL; p = &(*p)->next)
338 if ((*p)->pid == pid)
339 {
340 struct simple_pid_list *next = (*p)->next;
341
342 *statusp = (*p)->status;
343 xfree (*p);
344 *p = next;
345 return 1;
346 }
347 return 0;
348 }
349
350 static void
351 linux_record_stopped_pid (int pid, int status)
352 {
353 add_to_pid_list (&stopped_pids, pid, status);
354 }
355
356 \f
357 /* A helper function for linux_test_for_tracefork, called after fork (). */
358
359 static void
360 linux_tracefork_child (void)
361 {
362 ptrace (PTRACE_TRACEME, 0, 0, 0);
363 kill (getpid (), SIGSTOP);
364 fork ();
365 _exit (0);
366 }
367
368 /* Wrapper function for waitpid which handles EINTR. */
369
370 static int
371 my_waitpid (int pid, int *statusp, int flags)
372 {
373 int ret;
374
375 do
376 {
377 ret = waitpid (pid, statusp, flags);
378 }
379 while (ret == -1 && errno == EINTR);
380
381 return ret;
382 }
383
384 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events.
385
386 First, we try to enable fork tracing on ORIGINAL_PID. If this fails,
387 we know that the feature is not available. This may change the tracing
388 options for ORIGINAL_PID, but we'll be setting them shortly anyway.
389
390 However, if it succeeds, we don't know for sure that the feature is
391 available; old versions of PTRACE_SETOPTIONS ignored unknown options. We
392 create a child process, attach to it, use PTRACE_SETOPTIONS to enable
393 fork tracing, and let it fork. If the process exits, we assume that we
394 can't use TRACEFORK; if we get the fork notification, and we can extract
395 the new child's PID, then we assume that we can. */
396
397 static void
398 linux_test_for_tracefork (int original_pid)
399 {
400 int child_pid, ret, status;
401 long second_pid;
402 sigset_t prev_mask;
403
404 /* We don't want those ptrace calls to be interrupted. */
405 block_child_signals (&prev_mask);
406
407 linux_supports_tracefork_flag = 0;
408 linux_supports_tracevforkdone_flag = 0;
409
410 ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACEFORK);
411 if (ret != 0)
412 {
413 restore_child_signals_mask (&prev_mask);
414 return;
415 }
416
417 child_pid = fork ();
418 if (child_pid == -1)
419 perror_with_name (("fork"));
420
421 if (child_pid == 0)
422 linux_tracefork_child ();
423
424 ret = my_waitpid (child_pid, &status, 0);
425 if (ret == -1)
426 perror_with_name (("waitpid"));
427 else if (ret != child_pid)
428 error (_("linux_test_for_tracefork: waitpid: unexpected result %d."), ret);
429 if (! WIFSTOPPED (status))
430 error (_("linux_test_for_tracefork: waitpid: unexpected status %d."),
431 status);
432
433 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK);
434 if (ret != 0)
435 {
436 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
437 if (ret != 0)
438 {
439 warning (_("linux_test_for_tracefork: failed to kill child"));
440 restore_child_signals_mask (&prev_mask);
441 return;
442 }
443
444 ret = my_waitpid (child_pid, &status, 0);
445 if (ret != child_pid)
446 warning (_("linux_test_for_tracefork: failed "
447 "to wait for killed child"));
448 else if (!WIFSIGNALED (status))
449 warning (_("linux_test_for_tracefork: unexpected "
450 "wait status 0x%x from killed child"), status);
451
452 restore_child_signals_mask (&prev_mask);
453 return;
454 }
455
456 /* Check whether PTRACE_O_TRACEVFORKDONE is available. */
457 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0,
458 PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORKDONE);
459 linux_supports_tracevforkdone_flag = (ret == 0);
460
461 ret = ptrace (PTRACE_CONT, child_pid, 0, 0);
462 if (ret != 0)
463 warning (_("linux_test_for_tracefork: failed to resume child"));
464
465 ret = my_waitpid (child_pid, &status, 0);
466
467 if (ret == child_pid && WIFSTOPPED (status)
468 && status >> 16 == PTRACE_EVENT_FORK)
469 {
470 second_pid = 0;
471 ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
472 if (ret == 0 && second_pid != 0)
473 {
474 int second_status;
475
476 linux_supports_tracefork_flag = 1;
477 my_waitpid (second_pid, &second_status, 0);
478 ret = ptrace (PTRACE_KILL, second_pid, 0, 0);
479 if (ret != 0)
480 warning (_("linux_test_for_tracefork: "
481 "failed to kill second child"));
482 my_waitpid (second_pid, &status, 0);
483 }
484 }
485 else
486 warning (_("linux_test_for_tracefork: unexpected result from waitpid "
487 "(%d, status 0x%x)"), ret, status);
488
489 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
490 if (ret != 0)
491 warning (_("linux_test_for_tracefork: failed to kill child"));
492 my_waitpid (child_pid, &status, 0);
493
494 restore_child_signals_mask (&prev_mask);
495 }
496
497 /* Determine if PTRACE_O_TRACESYSGOOD can be used to follow syscalls.
498
499 We try to enable syscall tracing on ORIGINAL_PID. If this fails,
500 we know that the feature is not available. This may change the tracing
501 options for ORIGINAL_PID, but we'll be setting them shortly anyway. */
502
503 static void
504 linux_test_for_tracesysgood (int original_pid)
505 {
506 int ret;
507 sigset_t prev_mask;
508
509 /* We don't want those ptrace calls to be interrupted. */
510 block_child_signals (&prev_mask);
511
512 linux_supports_tracesysgood_flag = 0;
513
514 ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACESYSGOOD);
515 if (ret != 0)
516 goto out;
517
518 linux_supports_tracesysgood_flag = 1;
519 out:
520 restore_child_signals_mask (&prev_mask);
521 }
522
523 /* Determine wether we support PTRACE_O_TRACESYSGOOD option available.
524 This function also sets linux_supports_tracesysgood_flag. */
525
526 static int
527 linux_supports_tracesysgood (int pid)
528 {
529 if (linux_supports_tracesysgood_flag == -1)
530 linux_test_for_tracesysgood (pid);
531 return linux_supports_tracesysgood_flag;
532 }
533
534 /* Return non-zero iff we have tracefork functionality available.
535 This function also sets linux_supports_tracefork_flag. */
536
537 static int
538 linux_supports_tracefork (int pid)
539 {
540 if (linux_supports_tracefork_flag == -1)
541 linux_test_for_tracefork (pid);
542 return linux_supports_tracefork_flag;
543 }
544
545 static int
546 linux_supports_tracevforkdone (int pid)
547 {
548 if (linux_supports_tracefork_flag == -1)
549 linux_test_for_tracefork (pid);
550 return linux_supports_tracevforkdone_flag;
551 }
552
553 static void
554 linux_enable_tracesysgood (ptid_t ptid)
555 {
556 int pid = ptid_get_lwp (ptid);
557
558 if (pid == 0)
559 pid = ptid_get_pid (ptid);
560
561 if (linux_supports_tracesysgood (pid) == 0)
562 return;
563
564 current_ptrace_options |= PTRACE_O_TRACESYSGOOD;
565
566 ptrace (PTRACE_SETOPTIONS, pid, 0, current_ptrace_options);
567 }
568
569 \f
570 void
571 linux_enable_event_reporting (ptid_t ptid)
572 {
573 int pid = ptid_get_lwp (ptid);
574
575 if (pid == 0)
576 pid = ptid_get_pid (ptid);
577
578 if (! linux_supports_tracefork (pid))
579 return;
580
581 current_ptrace_options |= PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK
582 | PTRACE_O_TRACEEXEC | PTRACE_O_TRACECLONE;
583
584 if (linux_supports_tracevforkdone (pid))
585 current_ptrace_options |= PTRACE_O_TRACEVFORKDONE;
586
587 /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support
588 read-only process state. */
589
590 ptrace (PTRACE_SETOPTIONS, pid, 0, current_ptrace_options);
591 }
592
593 static void
594 linux_child_post_attach (int pid)
595 {
596 linux_enable_event_reporting (pid_to_ptid (pid));
597 check_for_thread_db ();
598 linux_enable_tracesysgood (pid_to_ptid (pid));
599 }
600
601 static void
602 linux_child_post_startup_inferior (ptid_t ptid)
603 {
604 linux_enable_event_reporting (ptid);
605 check_for_thread_db ();
606 linux_enable_tracesysgood (ptid);
607 }
608
609 static int
610 linux_child_follow_fork (struct target_ops *ops, int follow_child)
611 {
612 sigset_t prev_mask;
613 int has_vforked;
614 int parent_pid, child_pid;
615
616 block_child_signals (&prev_mask);
617
618 has_vforked = (inferior_thread ()->pending_follow.kind
619 == TARGET_WAITKIND_VFORKED);
620 parent_pid = ptid_get_lwp (inferior_ptid);
621 if (parent_pid == 0)
622 parent_pid = ptid_get_pid (inferior_ptid);
623 child_pid = PIDGET (inferior_thread ()->pending_follow.value.related_pid);
624
625 if (!detach_fork)
626 linux_enable_event_reporting (pid_to_ptid (child_pid));
627
628 if (has_vforked
629 && !non_stop /* Non-stop always resumes both branches. */
630 && (!target_is_async_p () || sync_execution)
631 && !(follow_child || detach_fork || sched_multi))
632 {
633 /* The parent stays blocked inside the vfork syscall until the
634 child execs or exits. If we don't let the child run, then
635 the parent stays blocked. If we're telling the parent to run
636 in the foreground, the user will not be able to ctrl-c to get
637 back the terminal, effectively hanging the debug session. */
638 fprintf_filtered (gdb_stderr, _("\
639 Can not resume the parent process over vfork in the foreground while\n\
640 holding the child stopped. Try \"set detach-on-fork\" or \
641 \"set schedule-multiple\".\n"));
642 /* FIXME output string > 80 columns. */
643 return 1;
644 }
645
646 if (! follow_child)
647 {
648 struct lwp_info *child_lp = NULL;
649
650 /* We're already attached to the parent, by default. */
651
652 /* Detach new forked process? */
653 if (detach_fork)
654 {
655 /* Before detaching from the child, remove all breakpoints
656 from it. If we forked, then this has already been taken
657 care of by infrun.c. If we vforked however, any
658 breakpoint inserted in the parent is visible in the
659 child, even those added while stopped in a vfork
660 catchpoint. This will remove the breakpoints from the
661 parent also, but they'll be reinserted below. */
662 if (has_vforked)
663 {
664 /* keep breakpoints list in sync. */
665 remove_breakpoints_pid (GET_PID (inferior_ptid));
666 }
667
668 if (info_verbose || debug_linux_nat)
669 {
670 target_terminal_ours ();
671 fprintf_filtered (gdb_stdlog,
672 "Detaching after fork from "
673 "child process %d.\n",
674 child_pid);
675 }
676
677 ptrace (PTRACE_DETACH, child_pid, 0, 0);
678 }
679 else
680 {
681 struct inferior *parent_inf, *child_inf;
682 struct cleanup *old_chain;
683
684 /* Add process to GDB's tables. */
685 child_inf = add_inferior (child_pid);
686
687 parent_inf = current_inferior ();
688 child_inf->attach_flag = parent_inf->attach_flag;
689 copy_terminal_info (child_inf, parent_inf);
690
691 old_chain = save_inferior_ptid ();
692 save_current_program_space ();
693
694 inferior_ptid = ptid_build (child_pid, child_pid, 0);
695 add_thread (inferior_ptid);
696 child_lp = add_lwp (inferior_ptid);
697 child_lp->stopped = 1;
698 child_lp->resumed = 1;
699
700 /* If this is a vfork child, then the address-space is
701 shared with the parent. */
702 if (has_vforked)
703 {
704 child_inf->pspace = parent_inf->pspace;
705 child_inf->aspace = parent_inf->aspace;
706
707 /* The parent will be frozen until the child is done
708 with the shared region. Keep track of the
709 parent. */
710 child_inf->vfork_parent = parent_inf;
711 child_inf->pending_detach = 0;
712 parent_inf->vfork_child = child_inf;
713 parent_inf->pending_detach = 0;
714 }
715 else
716 {
717 child_inf->aspace = new_address_space ();
718 child_inf->pspace = add_program_space (child_inf->aspace);
719 child_inf->removable = 1;
720 set_current_program_space (child_inf->pspace);
721 clone_program_space (child_inf->pspace, parent_inf->pspace);
722
723 /* Let the shared library layer (solib-svr4) learn about
724 this new process, relocate the cloned exec, pull in
725 shared libraries, and install the solib event
726 breakpoint. If a "cloned-VM" event was propagated
727 better throughout the core, this wouldn't be
728 required. */
729 solib_create_inferior_hook (0);
730 }
731
732 /* Let the thread_db layer learn about this new process. */
733 check_for_thread_db ();
734
735 do_cleanups (old_chain);
736 }
737
738 if (has_vforked)
739 {
740 struct lwp_info *lp;
741 struct inferior *parent_inf;
742
743 parent_inf = current_inferior ();
744
745 /* If we detached from the child, then we have to be careful
746 to not insert breakpoints in the parent until the child
747 is done with the shared memory region. However, if we're
748 staying attached to the child, then we can and should
749 insert breakpoints, so that we can debug it. A
750 subsequent child exec or exit is enough to know when does
751 the child stops using the parent's address space. */
752 parent_inf->waiting_for_vfork_done = detach_fork;
753 parent_inf->pspace->breakpoints_not_allowed = detach_fork;
754
755 lp = find_lwp_pid (pid_to_ptid (parent_pid));
756 gdb_assert (linux_supports_tracefork_flag >= 0);
757 if (linux_supports_tracevforkdone (0))
758 {
759 if (debug_linux_nat)
760 fprintf_unfiltered (gdb_stdlog,
761 "LCFF: waiting for VFORK_DONE on %d\n",
762 parent_pid);
763
764 lp->stopped = 1;
765 lp->resumed = 1;
766
767 /* We'll handle the VFORK_DONE event like any other
768 event, in target_wait. */
769 }
770 else
771 {
772 /* We can't insert breakpoints until the child has
773 finished with the shared memory region. We need to
774 wait until that happens. Ideal would be to just
775 call:
776 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
777 - waitpid (parent_pid, &status, __WALL);
778 However, most architectures can't handle a syscall
779 being traced on the way out if it wasn't traced on
780 the way in.
781
782 We might also think to loop, continuing the child
783 until it exits or gets a SIGTRAP. One problem is
784 that the child might call ptrace with PTRACE_TRACEME.
785
786 There's no simple and reliable way to figure out when
787 the vforked child will be done with its copy of the
788 shared memory. We could step it out of the syscall,
789 two instructions, let it go, and then single-step the
790 parent once. When we have hardware single-step, this
791 would work; with software single-step it could still
792 be made to work but we'd have to be able to insert
793 single-step breakpoints in the child, and we'd have
794 to insert -just- the single-step breakpoint in the
795 parent. Very awkward.
796
797 In the end, the best we can do is to make sure it
798 runs for a little while. Hopefully it will be out of
799 range of any breakpoints we reinsert. Usually this
800 is only the single-step breakpoint at vfork's return
801 point. */
802
803 if (debug_linux_nat)
804 fprintf_unfiltered (gdb_stdlog,
805 "LCFF: no VFORK_DONE "
806 "support, sleeping a bit\n");
807
808 usleep (10000);
809
810 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
811 and leave it pending. The next linux_nat_resume call
812 will notice a pending event, and bypasses actually
813 resuming the inferior. */
814 lp->status = 0;
815 lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE;
816 lp->stopped = 0;
817 lp->resumed = 1;
818
819 /* If we're in async mode, need to tell the event loop
820 there's something here to process. */
821 if (target_can_async_p ())
822 async_file_mark ();
823 }
824 }
825 }
826 else
827 {
828 struct inferior *parent_inf, *child_inf;
829 struct lwp_info *lp;
830 struct program_space *parent_pspace;
831
832 if (info_verbose || debug_linux_nat)
833 {
834 target_terminal_ours ();
835 if (has_vforked)
836 fprintf_filtered (gdb_stdlog,
837 _("Attaching after process %d "
838 "vfork to child process %d.\n"),
839 parent_pid, child_pid);
840 else
841 fprintf_filtered (gdb_stdlog,
842 _("Attaching after process %d "
843 "fork to child process %d.\n"),
844 parent_pid, child_pid);
845 }
846
847 /* Add the new inferior first, so that the target_detach below
848 doesn't unpush the target. */
849
850 child_inf = add_inferior (child_pid);
851
852 parent_inf = current_inferior ();
853 child_inf->attach_flag = parent_inf->attach_flag;
854 copy_terminal_info (child_inf, parent_inf);
855
856 parent_pspace = parent_inf->pspace;
857
858 /* If we're vforking, we want to hold on to the parent until the
859 child exits or execs. At child exec or exit time we can
860 remove the old breakpoints from the parent and detach or
861 resume debugging it. Otherwise, detach the parent now; we'll
862 want to reuse it's program/address spaces, but we can't set
863 them to the child before removing breakpoints from the
864 parent, otherwise, the breakpoints module could decide to
865 remove breakpoints from the wrong process (since they'd be
866 assigned to the same address space). */
867
868 if (has_vforked)
869 {
870 gdb_assert (child_inf->vfork_parent == NULL);
871 gdb_assert (parent_inf->vfork_child == NULL);
872 child_inf->vfork_parent = parent_inf;
873 child_inf->pending_detach = 0;
874 parent_inf->vfork_child = child_inf;
875 parent_inf->pending_detach = detach_fork;
876 parent_inf->waiting_for_vfork_done = 0;
877 }
878 else if (detach_fork)
879 target_detach (NULL, 0);
880
881 /* Note that the detach above makes PARENT_INF dangling. */
882
883 /* Add the child thread to the appropriate lists, and switch to
884 this new thread, before cloning the program space, and
885 informing the solib layer about this new process. */
886
887 inferior_ptid = ptid_build (child_pid, child_pid, 0);
888 add_thread (inferior_ptid);
889 lp = add_lwp (inferior_ptid);
890 lp->stopped = 1;
891 lp->resumed = 1;
892
893 /* If this is a vfork child, then the address-space is shared
894 with the parent. If we detached from the parent, then we can
895 reuse the parent's program/address spaces. */
896 if (has_vforked || detach_fork)
897 {
898 child_inf->pspace = parent_pspace;
899 child_inf->aspace = child_inf->pspace->aspace;
900 }
901 else
902 {
903 child_inf->aspace = new_address_space ();
904 child_inf->pspace = add_program_space (child_inf->aspace);
905 child_inf->removable = 1;
906 set_current_program_space (child_inf->pspace);
907 clone_program_space (child_inf->pspace, parent_pspace);
908
909 /* Let the shared library layer (solib-svr4) learn about
910 this new process, relocate the cloned exec, pull in
911 shared libraries, and install the solib event breakpoint.
912 If a "cloned-VM" event was propagated better throughout
913 the core, this wouldn't be required. */
914 solib_create_inferior_hook (0);
915 }
916
917 /* Let the thread_db layer learn about this new process. */
918 check_for_thread_db ();
919 }
920
921 restore_child_signals_mask (&prev_mask);
922 return 0;
923 }
924
925 \f
926 static int
927 linux_child_insert_fork_catchpoint (int pid)
928 {
929 return !linux_supports_tracefork (pid);
930 }
931
932 static int
933 linux_child_remove_fork_catchpoint (int pid)
934 {
935 return 0;
936 }
937
938 static int
939 linux_child_insert_vfork_catchpoint (int pid)
940 {
941 return !linux_supports_tracefork (pid);
942 }
943
944 static int
945 linux_child_remove_vfork_catchpoint (int pid)
946 {
947 return 0;
948 }
949
950 static int
951 linux_child_insert_exec_catchpoint (int pid)
952 {
953 return !linux_supports_tracefork (pid);
954 }
955
956 static int
957 linux_child_remove_exec_catchpoint (int pid)
958 {
959 return 0;
960 }
961
962 static int
963 linux_child_set_syscall_catchpoint (int pid, int needed, int any_count,
964 int table_size, int *table)
965 {
966 if (!linux_supports_tracesysgood (pid))
967 return 1;
968
969 /* On GNU/Linux, we ignore the arguments. It means that we only
970 enable the syscall catchpoints, but do not disable them.
971
972 Also, we do not use the `table' information because we do not
973 filter system calls here. We let GDB do the logic for us. */
974 return 0;
975 }
976
977 /* On GNU/Linux there are no real LWP's. The closest thing to LWP's
978 are processes sharing the same VM space. A multi-threaded process
979 is basically a group of such processes. However, such a grouping
980 is almost entirely a user-space issue; the kernel doesn't enforce
981 such a grouping at all (this might change in the future). In
982 general, we'll rely on the threads library (i.e. the GNU/Linux
983 Threads library) to provide such a grouping.
984
985 It is perfectly well possible to write a multi-threaded application
986 without the assistance of a threads library, by using the clone
987 system call directly. This module should be able to give some
988 rudimentary support for debugging such applications if developers
989 specify the CLONE_PTRACE flag in the clone system call, and are
990 using the Linux kernel 2.4 or above.
991
992 Note that there are some peculiarities in GNU/Linux that affect
993 this code:
994
995 - In general one should specify the __WCLONE flag to waitpid in
996 order to make it report events for any of the cloned processes
997 (and leave it out for the initial process). However, if a cloned
998 process has exited the exit status is only reported if the
999 __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
1000 we cannot use it since GDB must work on older systems too.
1001
1002 - When a traced, cloned process exits and is waited for by the
1003 debugger, the kernel reassigns it to the original parent and
1004 keeps it around as a "zombie". Somehow, the GNU/Linux Threads
1005 library doesn't notice this, which leads to the "zombie problem":
1006 When debugged a multi-threaded process that spawns a lot of
1007 threads will run out of processes, even if the threads exit,
1008 because the "zombies" stay around. */
1009
1010 /* List of known LWPs. */
1011 struct lwp_info *lwp_list;
1012 \f
1013
1014 /* Original signal mask. */
1015 static sigset_t normal_mask;
1016
1017 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
1018 _initialize_linux_nat. */
1019 static sigset_t suspend_mask;
1020
1021 /* Signals to block to make that sigsuspend work. */
1022 static sigset_t blocked_mask;
1023
1024 /* SIGCHLD action. */
1025 struct sigaction sigchld_action;
1026
1027 /* Block child signals (SIGCHLD and linux threads signals), and store
1028 the previous mask in PREV_MASK. */
1029
1030 static void
1031 block_child_signals (sigset_t *prev_mask)
1032 {
1033 /* Make sure SIGCHLD is blocked. */
1034 if (!sigismember (&blocked_mask, SIGCHLD))
1035 sigaddset (&blocked_mask, SIGCHLD);
1036
1037 sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask);
1038 }
1039
1040 /* Restore child signals mask, previously returned by
1041 block_child_signals. */
1042
1043 static void
1044 restore_child_signals_mask (sigset_t *prev_mask)
1045 {
1046 sigprocmask (SIG_SETMASK, prev_mask, NULL);
1047 }
1048
1049 /* Mask of signals to pass directly to the inferior. */
1050 static sigset_t pass_mask;
1051
1052 /* Update signals to pass to the inferior. */
1053 static void
1054 linux_nat_pass_signals (int numsigs, unsigned char *pass_signals)
1055 {
1056 int signo;
1057
1058 sigemptyset (&pass_mask);
1059
1060 for (signo = 1; signo < NSIG; signo++)
1061 {
1062 int target_signo = target_signal_from_host (signo);
1063 if (target_signo < numsigs && pass_signals[target_signo])
1064 sigaddset (&pass_mask, signo);
1065 }
1066 }
1067
1068 \f
1069
1070 /* Prototypes for local functions. */
1071 static int stop_wait_callback (struct lwp_info *lp, void *data);
1072 static int linux_thread_alive (ptid_t ptid);
1073 static char *linux_child_pid_to_exec_file (int pid);
1074
1075 \f
1076 /* Convert wait status STATUS to a string. Used for printing debug
1077 messages only. */
1078
1079 static char *
1080 status_to_str (int status)
1081 {
1082 static char buf[64];
1083
1084 if (WIFSTOPPED (status))
1085 {
1086 if (WSTOPSIG (status) == SYSCALL_SIGTRAP)
1087 snprintf (buf, sizeof (buf), "%s (stopped at syscall)",
1088 strsignal (SIGTRAP));
1089 else
1090 snprintf (buf, sizeof (buf), "%s (stopped)",
1091 strsignal (WSTOPSIG (status)));
1092 }
1093 else if (WIFSIGNALED (status))
1094 snprintf (buf, sizeof (buf), "%s (terminated)",
1095 strsignal (WTERMSIG (status)));
1096 else
1097 snprintf (buf, sizeof (buf), "%d (exited)", WEXITSTATUS (status));
1098
1099 return buf;
1100 }
1101
1102 /* Remove all LWPs belong to PID from the lwp list. */
1103
1104 static void
1105 purge_lwp_list (int pid)
1106 {
1107 struct lwp_info *lp, *lpprev, *lpnext;
1108
1109 lpprev = NULL;
1110
1111 for (lp = lwp_list; lp; lp = lpnext)
1112 {
1113 lpnext = lp->next;
1114
1115 if (ptid_get_pid (lp->ptid) == pid)
1116 {
1117 if (lp == lwp_list)
1118 lwp_list = lp->next;
1119 else
1120 lpprev->next = lp->next;
1121
1122 xfree (lp);
1123 }
1124 else
1125 lpprev = lp;
1126 }
1127 }
1128
1129 /* Return the number of known LWPs in the tgid given by PID. */
1130
1131 static int
1132 num_lwps (int pid)
1133 {
1134 int count = 0;
1135 struct lwp_info *lp;
1136
1137 for (lp = lwp_list; lp; lp = lp->next)
1138 if (ptid_get_pid (lp->ptid) == pid)
1139 count++;
1140
1141 return count;
1142 }
1143
1144 /* Add the LWP specified by PID to the list. Return a pointer to the
1145 structure describing the new LWP. The LWP should already be stopped
1146 (with an exception for the very first LWP). */
1147
1148 static struct lwp_info *
1149 add_lwp (ptid_t ptid)
1150 {
1151 struct lwp_info *lp;
1152
1153 gdb_assert (is_lwp (ptid));
1154
1155 lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info));
1156
1157 memset (lp, 0, sizeof (struct lwp_info));
1158
1159 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
1160
1161 lp->ptid = ptid;
1162 lp->core = -1;
1163
1164 lp->next = lwp_list;
1165 lwp_list = lp;
1166
1167 if (num_lwps (GET_PID (ptid)) > 1 && linux_nat_new_thread != NULL)
1168 linux_nat_new_thread (ptid);
1169
1170 return lp;
1171 }
1172
1173 /* Remove the LWP specified by PID from the list. */
1174
1175 static void
1176 delete_lwp (ptid_t ptid)
1177 {
1178 struct lwp_info *lp, *lpprev;
1179
1180 lpprev = NULL;
1181
1182 for (lp = lwp_list; lp; lpprev = lp, lp = lp->next)
1183 if (ptid_equal (lp->ptid, ptid))
1184 break;
1185
1186 if (!lp)
1187 return;
1188
1189 if (lpprev)
1190 lpprev->next = lp->next;
1191 else
1192 lwp_list = lp->next;
1193
1194 xfree (lp);
1195 }
1196
1197 /* Return a pointer to the structure describing the LWP corresponding
1198 to PID. If no corresponding LWP could be found, return NULL. */
1199
1200 static struct lwp_info *
1201 find_lwp_pid (ptid_t ptid)
1202 {
1203 struct lwp_info *lp;
1204 int lwp;
1205
1206 if (is_lwp (ptid))
1207 lwp = GET_LWP (ptid);
1208 else
1209 lwp = GET_PID (ptid);
1210
1211 for (lp = lwp_list; lp; lp = lp->next)
1212 if (lwp == GET_LWP (lp->ptid))
1213 return lp;
1214
1215 return NULL;
1216 }
1217
1218 /* Call CALLBACK with its second argument set to DATA for every LWP in
1219 the list. If CALLBACK returns 1 for a particular LWP, return a
1220 pointer to the structure describing that LWP immediately.
1221 Otherwise return NULL. */
1222
1223 struct lwp_info *
1224 iterate_over_lwps (ptid_t filter,
1225 int (*callback) (struct lwp_info *, void *),
1226 void *data)
1227 {
1228 struct lwp_info *lp, *lpnext;
1229
1230 for (lp = lwp_list; lp; lp = lpnext)
1231 {
1232 lpnext = lp->next;
1233
1234 if (ptid_match (lp->ptid, filter))
1235 {
1236 if ((*callback) (lp, data))
1237 return lp;
1238 }
1239 }
1240
1241 return NULL;
1242 }
1243
1244 /* Update our internal state when changing from one checkpoint to
1245 another indicated by NEW_PTID. We can only switch single-threaded
1246 applications, so we only create one new LWP, and the previous list
1247 is discarded. */
1248
1249 void
1250 linux_nat_switch_fork (ptid_t new_ptid)
1251 {
1252 struct lwp_info *lp;
1253
1254 purge_lwp_list (GET_PID (inferior_ptid));
1255
1256 lp = add_lwp (new_ptid);
1257 lp->stopped = 1;
1258
1259 /* This changes the thread's ptid while preserving the gdb thread
1260 num. Also changes the inferior pid, while preserving the
1261 inferior num. */
1262 thread_change_ptid (inferior_ptid, new_ptid);
1263
1264 /* We've just told GDB core that the thread changed target id, but,
1265 in fact, it really is a different thread, with different register
1266 contents. */
1267 registers_changed ();
1268 }
1269
1270 /* Handle the exit of a single thread LP. */
1271
1272 static void
1273 exit_lwp (struct lwp_info *lp)
1274 {
1275 struct thread_info *th = find_thread_ptid (lp->ptid);
1276
1277 if (th)
1278 {
1279 if (print_thread_events)
1280 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid));
1281
1282 delete_thread (lp->ptid);
1283 }
1284
1285 delete_lwp (lp->ptid);
1286 }
1287
1288 /* Return an lwp's tgid, found in `/proc/PID/status'. */
1289
1290 int
1291 linux_proc_get_tgid (int lwpid)
1292 {
1293 FILE *status_file;
1294 char buf[100];
1295 int tgid = -1;
1296
1297 snprintf (buf, sizeof (buf), "/proc/%d/status", (int) lwpid);
1298 status_file = fopen (buf, "r");
1299 if (status_file != NULL)
1300 {
1301 while (fgets (buf, sizeof (buf), status_file))
1302 {
1303 if (strncmp (buf, "Tgid:", 5) == 0)
1304 {
1305 tgid = strtoul (buf + strlen ("Tgid:"), NULL, 10);
1306 break;
1307 }
1308 }
1309
1310 fclose (status_file);
1311 }
1312
1313 return tgid;
1314 }
1315
1316 /* Detect `T (stopped)' in `/proc/PID/status'.
1317 Other states including `T (tracing stop)' are reported as false. */
1318
1319 static int
1320 pid_is_stopped (pid_t pid)
1321 {
1322 FILE *status_file;
1323 char buf[100];
1324 int retval = 0;
1325
1326 snprintf (buf, sizeof (buf), "/proc/%d/status", (int) pid);
1327 status_file = fopen (buf, "r");
1328 if (status_file != NULL)
1329 {
1330 int have_state = 0;
1331
1332 while (fgets (buf, sizeof (buf), status_file))
1333 {
1334 if (strncmp (buf, "State:", 6) == 0)
1335 {
1336 have_state = 1;
1337 break;
1338 }
1339 }
1340 if (have_state && strstr (buf, "T (stopped)") != NULL)
1341 retval = 1;
1342 fclose (status_file);
1343 }
1344 return retval;
1345 }
1346
1347 /* Wait for the LWP specified by LP, which we have just attached to.
1348 Returns a wait status for that LWP, to cache. */
1349
1350 static int
1351 linux_nat_post_attach_wait (ptid_t ptid, int first, int *cloned,
1352 int *signalled)
1353 {
1354 pid_t new_pid, pid = GET_LWP (ptid);
1355 int status;
1356
1357 if (pid_is_stopped (pid))
1358 {
1359 if (debug_linux_nat)
1360 fprintf_unfiltered (gdb_stdlog,
1361 "LNPAW: Attaching to a stopped process\n");
1362
1363 /* The process is definitely stopped. It is in a job control
1364 stop, unless the kernel predates the TASK_STOPPED /
1365 TASK_TRACED distinction, in which case it might be in a
1366 ptrace stop. Make sure it is in a ptrace stop; from there we
1367 can kill it, signal it, et cetera.
1368
1369 First make sure there is a pending SIGSTOP. Since we are
1370 already attached, the process can not transition from stopped
1371 to running without a PTRACE_CONT; so we know this signal will
1372 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1373 probably already in the queue (unless this kernel is old
1374 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1375 is not an RT signal, it can only be queued once. */
1376 kill_lwp (pid, SIGSTOP);
1377
1378 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1379 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1380 ptrace (PTRACE_CONT, pid, 0, 0);
1381 }
1382
1383 /* Make sure the initial process is stopped. The user-level threads
1384 layer might want to poke around in the inferior, and that won't
1385 work if things haven't stabilized yet. */
1386 new_pid = my_waitpid (pid, &status, 0);
1387 if (new_pid == -1 && errno == ECHILD)
1388 {
1389 if (first)
1390 warning (_("%s is a cloned process"), target_pid_to_str (ptid));
1391
1392 /* Try again with __WCLONE to check cloned processes. */
1393 new_pid = my_waitpid (pid, &status, __WCLONE);
1394 *cloned = 1;
1395 }
1396
1397 gdb_assert (pid == new_pid);
1398
1399 if (!WIFSTOPPED (status))
1400 {
1401 /* The pid we tried to attach has apparently just exited. */
1402 if (debug_linux_nat)
1403 fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s",
1404 pid, status_to_str (status));
1405 return status;
1406 }
1407
1408 if (WSTOPSIG (status) != SIGSTOP)
1409 {
1410 *signalled = 1;
1411 if (debug_linux_nat)
1412 fprintf_unfiltered (gdb_stdlog,
1413 "LNPAW: Received %s after attaching\n",
1414 status_to_str (status));
1415 }
1416
1417 return status;
1418 }
1419
1420 /* Attach to the LWP specified by PID. Return 0 if successful or -1
1421 if the new LWP could not be attached. */
1422
1423 int
1424 lin_lwp_attach_lwp (ptid_t ptid)
1425 {
1426 struct lwp_info *lp;
1427 sigset_t prev_mask;
1428
1429 gdb_assert (is_lwp (ptid));
1430
1431 block_child_signals (&prev_mask);
1432
1433 lp = find_lwp_pid (ptid);
1434
1435 /* We assume that we're already attached to any LWP that has an id
1436 equal to the overall process id, and to any LWP that is already
1437 in our list of LWPs. If we're not seeing exit events from threads
1438 and we've had PID wraparound since we last tried to stop all threads,
1439 this assumption might be wrong; fortunately, this is very unlikely
1440 to happen. */
1441 if (GET_LWP (ptid) != GET_PID (ptid) && lp == NULL)
1442 {
1443 int status, cloned = 0, signalled = 0;
1444
1445 if (ptrace (PTRACE_ATTACH, GET_LWP (ptid), 0, 0) < 0)
1446 {
1447 /* If we fail to attach to the thread, issue a warning,
1448 but continue. One way this can happen is if thread
1449 creation is interrupted; as of Linux kernel 2.6.19, a
1450 bug may place threads in the thread list and then fail
1451 to create them. */
1452 warning (_("Can't attach %s: %s"), target_pid_to_str (ptid),
1453 safe_strerror (errno));
1454 restore_child_signals_mask (&prev_mask);
1455 return -1;
1456 }
1457
1458 if (debug_linux_nat)
1459 fprintf_unfiltered (gdb_stdlog,
1460 "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
1461 target_pid_to_str (ptid));
1462
1463 status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled);
1464 if (!WIFSTOPPED (status))
1465 {
1466 restore_child_signals_mask (&prev_mask);
1467 return -1;
1468 }
1469
1470 lp = add_lwp (ptid);
1471 lp->stopped = 1;
1472 lp->cloned = cloned;
1473 lp->signalled = signalled;
1474 if (WSTOPSIG (status) != SIGSTOP)
1475 {
1476 lp->resumed = 1;
1477 lp->status = status;
1478 }
1479
1480 target_post_attach (GET_LWP (lp->ptid));
1481
1482 if (debug_linux_nat)
1483 {
1484 fprintf_unfiltered (gdb_stdlog,
1485 "LLAL: waitpid %s received %s\n",
1486 target_pid_to_str (ptid),
1487 status_to_str (status));
1488 }
1489 }
1490 else
1491 {
1492 /* We assume that the LWP representing the original process is
1493 already stopped. Mark it as stopped in the data structure
1494 that the GNU/linux ptrace layer uses to keep track of
1495 threads. Note that this won't have already been done since
1496 the main thread will have, we assume, been stopped by an
1497 attach from a different layer. */
1498 if (lp == NULL)
1499 lp = add_lwp (ptid);
1500 lp->stopped = 1;
1501 }
1502
1503 restore_child_signals_mask (&prev_mask);
1504 return 0;
1505 }
1506
1507 static void
1508 linux_nat_create_inferior (struct target_ops *ops,
1509 char *exec_file, char *allargs, char **env,
1510 int from_tty)
1511 {
1512 #ifdef HAVE_PERSONALITY
1513 int personality_orig = 0, personality_set = 0;
1514 #endif /* HAVE_PERSONALITY */
1515
1516 /* The fork_child mechanism is synchronous and calls target_wait, so
1517 we have to mask the async mode. */
1518
1519 #ifdef HAVE_PERSONALITY
1520 if (disable_randomization)
1521 {
1522 errno = 0;
1523 personality_orig = personality (0xffffffff);
1524 if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE))
1525 {
1526 personality_set = 1;
1527 personality (personality_orig | ADDR_NO_RANDOMIZE);
1528 }
1529 if (errno != 0 || (personality_set
1530 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE)))
1531 warning (_("Error disabling address space randomization: %s"),
1532 safe_strerror (errno));
1533 }
1534 #endif /* HAVE_PERSONALITY */
1535
1536 /* Make sure we report all signals during startup. */
1537 linux_nat_pass_signals (0, NULL);
1538
1539 linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty);
1540
1541 #ifdef HAVE_PERSONALITY
1542 if (personality_set)
1543 {
1544 errno = 0;
1545 personality (personality_orig);
1546 if (errno != 0)
1547 warning (_("Error restoring address space randomization: %s"),
1548 safe_strerror (errno));
1549 }
1550 #endif /* HAVE_PERSONALITY */
1551 }
1552
1553 static void
1554 linux_nat_attach (struct target_ops *ops, char *args, int from_tty)
1555 {
1556 struct lwp_info *lp;
1557 int status;
1558 ptid_t ptid;
1559
1560 /* Make sure we report all signals during attach. */
1561 linux_nat_pass_signals (0, NULL);
1562
1563 linux_ops->to_attach (ops, args, from_tty);
1564
1565 /* The ptrace base target adds the main thread with (pid,0,0)
1566 format. Decorate it with lwp info. */
1567 ptid = BUILD_LWP (GET_PID (inferior_ptid), GET_PID (inferior_ptid));
1568 thread_change_ptid (inferior_ptid, ptid);
1569
1570 /* Add the initial process as the first LWP to the list. */
1571 lp = add_lwp (ptid);
1572
1573 status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->cloned,
1574 &lp->signalled);
1575 if (!WIFSTOPPED (status))
1576 {
1577 if (WIFEXITED (status))
1578 {
1579 int exit_code = WEXITSTATUS (status);
1580
1581 target_terminal_ours ();
1582 target_mourn_inferior ();
1583 if (exit_code == 0)
1584 error (_("Unable to attach: program exited normally."));
1585 else
1586 error (_("Unable to attach: program exited with code %d."),
1587 exit_code);
1588 }
1589 else if (WIFSIGNALED (status))
1590 {
1591 enum target_signal signo;
1592
1593 target_terminal_ours ();
1594 target_mourn_inferior ();
1595
1596 signo = target_signal_from_host (WTERMSIG (status));
1597 error (_("Unable to attach: program terminated with signal "
1598 "%s, %s."),
1599 target_signal_to_name (signo),
1600 target_signal_to_string (signo));
1601 }
1602
1603 internal_error (__FILE__, __LINE__,
1604 _("unexpected status %d for PID %ld"),
1605 status, (long) GET_LWP (ptid));
1606 }
1607
1608 lp->stopped = 1;
1609
1610 /* Save the wait status to report later. */
1611 lp->resumed = 1;
1612 if (debug_linux_nat)
1613 fprintf_unfiltered (gdb_stdlog,
1614 "LNA: waitpid %ld, saving status %s\n",
1615 (long) GET_PID (lp->ptid), status_to_str (status));
1616
1617 lp->status = status;
1618
1619 if (target_can_async_p ())
1620 target_async (inferior_event_handler, 0);
1621 }
1622
1623 /* Get pending status of LP. */
1624 static int
1625 get_pending_status (struct lwp_info *lp, int *status)
1626 {
1627 enum target_signal signo = TARGET_SIGNAL_0;
1628
1629 /* If we paused threads momentarily, we may have stored pending
1630 events in lp->status or lp->waitstatus (see stop_wait_callback),
1631 and GDB core hasn't seen any signal for those threads.
1632 Otherwise, the last signal reported to the core is found in the
1633 thread object's stop_signal.
1634
1635 There's a corner case that isn't handled here at present. Only
1636 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1637 stop_signal make sense as a real signal to pass to the inferior.
1638 Some catchpoint related events, like
1639 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1640 to TARGET_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1641 those traps are debug API (ptrace in our case) related and
1642 induced; the inferior wouldn't see them if it wasn't being
1643 traced. Hence, we should never pass them to the inferior, even
1644 when set to pass state. Since this corner case isn't handled by
1645 infrun.c when proceeding with a signal, for consistency, neither
1646 do we handle it here (or elsewhere in the file we check for
1647 signal pass state). Normally SIGTRAP isn't set to pass state, so
1648 this is really a corner case. */
1649
1650 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
1651 signo = TARGET_SIGNAL_0; /* a pending ptrace event, not a real signal. */
1652 else if (lp->status)
1653 signo = target_signal_from_host (WSTOPSIG (lp->status));
1654 else if (non_stop && !is_executing (lp->ptid))
1655 {
1656 struct thread_info *tp = find_thread_ptid (lp->ptid);
1657
1658 signo = tp->suspend.stop_signal;
1659 }
1660 else if (!non_stop)
1661 {
1662 struct target_waitstatus last;
1663 ptid_t last_ptid;
1664
1665 get_last_target_status (&last_ptid, &last);
1666
1667 if (GET_LWP (lp->ptid) == GET_LWP (last_ptid))
1668 {
1669 struct thread_info *tp = find_thread_ptid (lp->ptid);
1670
1671 signo = tp->suspend.stop_signal;
1672 }
1673 }
1674
1675 *status = 0;
1676
1677 if (signo == TARGET_SIGNAL_0)
1678 {
1679 if (debug_linux_nat)
1680 fprintf_unfiltered (gdb_stdlog,
1681 "GPT: lwp %s has no pending signal\n",
1682 target_pid_to_str (lp->ptid));
1683 }
1684 else if (!signal_pass_state (signo))
1685 {
1686 if (debug_linux_nat)
1687 fprintf_unfiltered (gdb_stdlog,
1688 "GPT: lwp %s had signal %s, "
1689 "but it is in no pass state\n",
1690 target_pid_to_str (lp->ptid),
1691 target_signal_to_string (signo));
1692 }
1693 else
1694 {
1695 *status = W_STOPCODE (target_signal_to_host (signo));
1696
1697 if (debug_linux_nat)
1698 fprintf_unfiltered (gdb_stdlog,
1699 "GPT: lwp %s has pending signal %s\n",
1700 target_pid_to_str (lp->ptid),
1701 target_signal_to_string (signo));
1702 }
1703
1704 return 0;
1705 }
1706
1707 static int
1708 detach_callback (struct lwp_info *lp, void *data)
1709 {
1710 gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status));
1711
1712 if (debug_linux_nat && lp->status)
1713 fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n",
1714 strsignal (WSTOPSIG (lp->status)),
1715 target_pid_to_str (lp->ptid));
1716
1717 /* If there is a pending SIGSTOP, get rid of it. */
1718 if (lp->signalled)
1719 {
1720 if (debug_linux_nat)
1721 fprintf_unfiltered (gdb_stdlog,
1722 "DC: Sending SIGCONT to %s\n",
1723 target_pid_to_str (lp->ptid));
1724
1725 kill_lwp (GET_LWP (lp->ptid), SIGCONT);
1726 lp->signalled = 0;
1727 }
1728
1729 /* We don't actually detach from the LWP that has an id equal to the
1730 overall process id just yet. */
1731 if (GET_LWP (lp->ptid) != GET_PID (lp->ptid))
1732 {
1733 int status = 0;
1734
1735 /* Pass on any pending signal for this LWP. */
1736 get_pending_status (lp, &status);
1737
1738 errno = 0;
1739 if (ptrace (PTRACE_DETACH, GET_LWP (lp->ptid), 0,
1740 WSTOPSIG (status)) < 0)
1741 error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid),
1742 safe_strerror (errno));
1743
1744 if (debug_linux_nat)
1745 fprintf_unfiltered (gdb_stdlog,
1746 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1747 target_pid_to_str (lp->ptid),
1748 strsignal (WSTOPSIG (status)));
1749
1750 delete_lwp (lp->ptid);
1751 }
1752
1753 return 0;
1754 }
1755
1756 static void
1757 linux_nat_detach (struct target_ops *ops, char *args, int from_tty)
1758 {
1759 int pid;
1760 int status;
1761 struct lwp_info *main_lwp;
1762
1763 pid = GET_PID (inferior_ptid);
1764
1765 if (target_can_async_p ())
1766 linux_nat_async (NULL, 0);
1767
1768 /* Stop all threads before detaching. ptrace requires that the
1769 thread is stopped to sucessfully detach. */
1770 iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL);
1771 /* ... and wait until all of them have reported back that
1772 they're no longer running. */
1773 iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL);
1774
1775 iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL);
1776
1777 /* Only the initial process should be left right now. */
1778 gdb_assert (num_lwps (GET_PID (inferior_ptid)) == 1);
1779
1780 main_lwp = find_lwp_pid (pid_to_ptid (pid));
1781
1782 /* Pass on any pending signal for the last LWP. */
1783 if ((args == NULL || *args == '\0')
1784 && get_pending_status (main_lwp, &status) != -1
1785 && WIFSTOPPED (status))
1786 {
1787 /* Put the signal number in ARGS so that inf_ptrace_detach will
1788 pass it along with PTRACE_DETACH. */
1789 args = alloca (8);
1790 sprintf (args, "%d", (int) WSTOPSIG (status));
1791 if (debug_linux_nat)
1792 fprintf_unfiltered (gdb_stdlog,
1793 "LND: Sending signal %s to %s\n",
1794 args,
1795 target_pid_to_str (main_lwp->ptid));
1796 }
1797
1798 delete_lwp (main_lwp->ptid);
1799
1800 if (forks_exist_p ())
1801 {
1802 /* Multi-fork case. The current inferior_ptid is being detached
1803 from, but there are other viable forks to debug. Detach from
1804 the current fork, and context-switch to the first
1805 available. */
1806 linux_fork_detach (args, from_tty);
1807
1808 if (non_stop && target_can_async_p ())
1809 target_async (inferior_event_handler, 0);
1810 }
1811 else
1812 linux_ops->to_detach (ops, args, from_tty);
1813 }
1814
1815 /* Resume LP. */
1816
1817 static int
1818 resume_callback (struct lwp_info *lp, void *data)
1819 {
1820 struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid));
1821
1822 if (lp->stopped && inf->vfork_child != NULL)
1823 {
1824 if (debug_linux_nat)
1825 fprintf_unfiltered (gdb_stdlog,
1826 "RC: Not resuming %s (vfork parent)\n",
1827 target_pid_to_str (lp->ptid));
1828 }
1829 else if (lp->stopped && lp->status == 0)
1830 {
1831 if (debug_linux_nat)
1832 fprintf_unfiltered (gdb_stdlog,
1833 "RC: PTRACE_CONT %s, 0, 0 (resuming sibling)\n",
1834 target_pid_to_str (lp->ptid));
1835
1836 linux_ops->to_resume (linux_ops,
1837 pid_to_ptid (GET_LWP (lp->ptid)),
1838 0, TARGET_SIGNAL_0);
1839 if (debug_linux_nat)
1840 fprintf_unfiltered (gdb_stdlog,
1841 "RC: PTRACE_CONT %s, 0, 0 (resume sibling)\n",
1842 target_pid_to_str (lp->ptid));
1843 lp->stopped = 0;
1844 lp->step = 0;
1845 memset (&lp->siginfo, 0, sizeof (lp->siginfo));
1846 lp->stopped_by_watchpoint = 0;
1847 }
1848 else if (lp->stopped && debug_linux_nat)
1849 fprintf_unfiltered (gdb_stdlog,
1850 "RC: Not resuming sibling %s (has pending)\n",
1851 target_pid_to_str (lp->ptid));
1852 else if (debug_linux_nat)
1853 fprintf_unfiltered (gdb_stdlog,
1854 "RC: Not resuming sibling %s (not stopped)\n",
1855 target_pid_to_str (lp->ptid));
1856
1857 return 0;
1858 }
1859
1860 static int
1861 resume_clear_callback (struct lwp_info *lp, void *data)
1862 {
1863 lp->resumed = 0;
1864 return 0;
1865 }
1866
1867 static int
1868 resume_set_callback (struct lwp_info *lp, void *data)
1869 {
1870 lp->resumed = 1;
1871 return 0;
1872 }
1873
1874 static void
1875 linux_nat_resume (struct target_ops *ops,
1876 ptid_t ptid, int step, enum target_signal signo)
1877 {
1878 sigset_t prev_mask;
1879 struct lwp_info *lp;
1880 int resume_many;
1881
1882 if (debug_linux_nat)
1883 fprintf_unfiltered (gdb_stdlog,
1884 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1885 step ? "step" : "resume",
1886 target_pid_to_str (ptid),
1887 (signo != TARGET_SIGNAL_0
1888 ? strsignal (target_signal_to_host (signo)) : "0"),
1889 target_pid_to_str (inferior_ptid));
1890
1891 block_child_signals (&prev_mask);
1892
1893 /* A specific PTID means `step only this process id'. */
1894 resume_many = (ptid_equal (minus_one_ptid, ptid)
1895 || ptid_is_pid (ptid));
1896
1897 /* Mark the lwps we're resuming as resumed. */
1898 iterate_over_lwps (ptid, resume_set_callback, NULL);
1899
1900 /* See if it's the current inferior that should be handled
1901 specially. */
1902 if (resume_many)
1903 lp = find_lwp_pid (inferior_ptid);
1904 else
1905 lp = find_lwp_pid (ptid);
1906 gdb_assert (lp != NULL);
1907
1908 /* Remember if we're stepping. */
1909 lp->step = step;
1910
1911 /* If we have a pending wait status for this thread, there is no
1912 point in resuming the process. But first make sure that
1913 linux_nat_wait won't preemptively handle the event - we
1914 should never take this short-circuit if we are going to
1915 leave LP running, since we have skipped resuming all the
1916 other threads. This bit of code needs to be synchronized
1917 with linux_nat_wait. */
1918
1919 if (lp->status && WIFSTOPPED (lp->status))
1920 {
1921 if (!lp->step
1922 && WSTOPSIG (lp->status)
1923 && sigismember (&pass_mask, WSTOPSIG (lp->status)))
1924 {
1925 if (debug_linux_nat)
1926 fprintf_unfiltered (gdb_stdlog,
1927 "LLR: Not short circuiting for ignored "
1928 "status 0x%x\n", lp->status);
1929
1930 /* FIXME: What should we do if we are supposed to continue
1931 this thread with a signal? */
1932 gdb_assert (signo == TARGET_SIGNAL_0);
1933 signo = target_signal_from_host (WSTOPSIG (lp->status));
1934 lp->status = 0;
1935 }
1936 }
1937
1938 if (lp->status || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
1939 {
1940 /* FIXME: What should we do if we are supposed to continue
1941 this thread with a signal? */
1942 gdb_assert (signo == TARGET_SIGNAL_0);
1943
1944 if (debug_linux_nat)
1945 fprintf_unfiltered (gdb_stdlog,
1946 "LLR: Short circuiting for status 0x%x\n",
1947 lp->status);
1948
1949 restore_child_signals_mask (&prev_mask);
1950 if (target_can_async_p ())
1951 {
1952 target_async (inferior_event_handler, 0);
1953 /* Tell the event loop we have something to process. */
1954 async_file_mark ();
1955 }
1956 return;
1957 }
1958
1959 /* Mark LWP as not stopped to prevent it from being continued by
1960 resume_callback. */
1961 lp->stopped = 0;
1962
1963 if (resume_many)
1964 iterate_over_lwps (ptid, resume_callback, NULL);
1965
1966 /* Convert to something the lower layer understands. */
1967 ptid = pid_to_ptid (GET_LWP (lp->ptid));
1968
1969 linux_ops->to_resume (linux_ops, ptid, step, signo);
1970 memset (&lp->siginfo, 0, sizeof (lp->siginfo));
1971 lp->stopped_by_watchpoint = 0;
1972
1973 if (debug_linux_nat)
1974 fprintf_unfiltered (gdb_stdlog,
1975 "LLR: %s %s, %s (resume event thread)\n",
1976 step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1977 target_pid_to_str (ptid),
1978 (signo != TARGET_SIGNAL_0
1979 ? strsignal (target_signal_to_host (signo)) : "0"));
1980
1981 restore_child_signals_mask (&prev_mask);
1982 if (target_can_async_p ())
1983 target_async (inferior_event_handler, 0);
1984 }
1985
1986 /* Send a signal to an LWP. */
1987
1988 static int
1989 kill_lwp (int lwpid, int signo)
1990 {
1991 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1992 fails, then we are not using nptl threads and we should be using kill. */
1993
1994 #ifdef HAVE_TKILL_SYSCALL
1995 {
1996 static int tkill_failed;
1997
1998 if (!tkill_failed)
1999 {
2000 int ret;
2001
2002 errno = 0;
2003 ret = syscall (__NR_tkill, lwpid, signo);
2004 if (errno != ENOSYS)
2005 return ret;
2006 tkill_failed = 1;
2007 }
2008 }
2009 #endif
2010
2011 return kill (lwpid, signo);
2012 }
2013
2014 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
2015 event, check if the core is interested in it: if not, ignore the
2016 event, and keep waiting; otherwise, we need to toggle the LWP's
2017 syscall entry/exit status, since the ptrace event itself doesn't
2018 indicate it, and report the trap to higher layers. */
2019
2020 static int
2021 linux_handle_syscall_trap (struct lwp_info *lp, int stopping)
2022 {
2023 struct target_waitstatus *ourstatus = &lp->waitstatus;
2024 struct gdbarch *gdbarch = target_thread_architecture (lp->ptid);
2025 int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid);
2026
2027 if (stopping)
2028 {
2029 /* If we're stopping threads, there's a SIGSTOP pending, which
2030 makes it so that the LWP reports an immediate syscall return,
2031 followed by the SIGSTOP. Skip seeing that "return" using
2032 PTRACE_CONT directly, and let stop_wait_callback collect the
2033 SIGSTOP. Later when the thread is resumed, a new syscall
2034 entry event. If we didn't do this (and returned 0), we'd
2035 leave a syscall entry pending, and our caller, by using
2036 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
2037 itself. Later, when the user re-resumes this LWP, we'd see
2038 another syscall entry event and we'd mistake it for a return.
2039
2040 If stop_wait_callback didn't force the SIGSTOP out of the LWP
2041 (leaving immediately with LWP->signalled set, without issuing
2042 a PTRACE_CONT), it would still be problematic to leave this
2043 syscall enter pending, as later when the thread is resumed,
2044 it would then see the same syscall exit mentioned above,
2045 followed by the delayed SIGSTOP, while the syscall didn't
2046 actually get to execute. It seems it would be even more
2047 confusing to the user. */
2048
2049 if (debug_linux_nat)
2050 fprintf_unfiltered (gdb_stdlog,
2051 "LHST: ignoring syscall %d "
2052 "for LWP %ld (stopping threads), "
2053 "resuming with PTRACE_CONT for SIGSTOP\n",
2054 syscall_number,
2055 GET_LWP (lp->ptid));
2056
2057 lp->syscall_state = TARGET_WAITKIND_IGNORE;
2058 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2059 return 1;
2060 }
2061
2062 if (catch_syscall_enabled ())
2063 {
2064 /* Always update the entry/return state, even if this particular
2065 syscall isn't interesting to the core now. In async mode,
2066 the user could install a new catchpoint for this syscall
2067 between syscall enter/return, and we'll need to know to
2068 report a syscall return if that happens. */
2069 lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
2070 ? TARGET_WAITKIND_SYSCALL_RETURN
2071 : TARGET_WAITKIND_SYSCALL_ENTRY);
2072
2073 if (catching_syscall_number (syscall_number))
2074 {
2075 /* Alright, an event to report. */
2076 ourstatus->kind = lp->syscall_state;
2077 ourstatus->value.syscall_number = syscall_number;
2078
2079 if (debug_linux_nat)
2080 fprintf_unfiltered (gdb_stdlog,
2081 "LHST: stopping for %s of syscall %d"
2082 " for LWP %ld\n",
2083 lp->syscall_state
2084 == TARGET_WAITKIND_SYSCALL_ENTRY
2085 ? "entry" : "return",
2086 syscall_number,
2087 GET_LWP (lp->ptid));
2088 return 0;
2089 }
2090
2091 if (debug_linux_nat)
2092 fprintf_unfiltered (gdb_stdlog,
2093 "LHST: ignoring %s of syscall %d "
2094 "for LWP %ld\n",
2095 lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
2096 ? "entry" : "return",
2097 syscall_number,
2098 GET_LWP (lp->ptid));
2099 }
2100 else
2101 {
2102 /* If we had been syscall tracing, and hence used PT_SYSCALL
2103 before on this LWP, it could happen that the user removes all
2104 syscall catchpoints before we get to process this event.
2105 There are two noteworthy issues here:
2106
2107 - When stopped at a syscall entry event, resuming with
2108 PT_STEP still resumes executing the syscall and reports a
2109 syscall return.
2110
2111 - Only PT_SYSCALL catches syscall enters. If we last
2112 single-stepped this thread, then this event can't be a
2113 syscall enter. If we last single-stepped this thread, this
2114 has to be a syscall exit.
2115
2116 The points above mean that the next resume, be it PT_STEP or
2117 PT_CONTINUE, can not trigger a syscall trace event. */
2118 if (debug_linux_nat)
2119 fprintf_unfiltered (gdb_stdlog,
2120 "LHST: caught syscall event "
2121 "with no syscall catchpoints."
2122 " %d for LWP %ld, ignoring\n",
2123 syscall_number,
2124 GET_LWP (lp->ptid));
2125 lp->syscall_state = TARGET_WAITKIND_IGNORE;
2126 }
2127
2128 /* The core isn't interested in this event. For efficiency, avoid
2129 stopping all threads only to have the core resume them all again.
2130 Since we're not stopping threads, if we're still syscall tracing
2131 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
2132 subsequent syscall. Simply resume using the inf-ptrace layer,
2133 which knows when to use PT_SYSCALL or PT_CONTINUE. */
2134
2135 /* Note that gdbarch_get_syscall_number may access registers, hence
2136 fill a regcache. */
2137 registers_changed ();
2138 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
2139 lp->step, TARGET_SIGNAL_0);
2140 return 1;
2141 }
2142
2143 /* Handle a GNU/Linux extended wait response. If we see a clone
2144 event, we need to add the new LWP to our list (and not report the
2145 trap to higher layers). This function returns non-zero if the
2146 event should be ignored and we should wait again. If STOPPING is
2147 true, the new LWP remains stopped, otherwise it is continued. */
2148
2149 static int
2150 linux_handle_extended_wait (struct lwp_info *lp, int status,
2151 int stopping)
2152 {
2153 int pid = GET_LWP (lp->ptid);
2154 struct target_waitstatus *ourstatus = &lp->waitstatus;
2155 int event = status >> 16;
2156
2157 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK
2158 || event == PTRACE_EVENT_CLONE)
2159 {
2160 unsigned long new_pid;
2161 int ret;
2162
2163 ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid);
2164
2165 /* If we haven't already seen the new PID stop, wait for it now. */
2166 if (! pull_pid_from_list (&stopped_pids, new_pid, &status))
2167 {
2168 /* The new child has a pending SIGSTOP. We can't affect it until it
2169 hits the SIGSTOP, but we're already attached. */
2170 ret = my_waitpid (new_pid, &status,
2171 (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0);
2172 if (ret == -1)
2173 perror_with_name (_("waiting for new child"));
2174 else if (ret != new_pid)
2175 internal_error (__FILE__, __LINE__,
2176 _("wait returned unexpected PID %d"), ret);
2177 else if (!WIFSTOPPED (status))
2178 internal_error (__FILE__, __LINE__,
2179 _("wait returned unexpected status 0x%x"), status);
2180 }
2181
2182 ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0);
2183
2184 if (event == PTRACE_EVENT_FORK
2185 && linux_fork_checkpointing_p (GET_PID (lp->ptid)))
2186 {
2187 /* Handle checkpointing by linux-fork.c here as a special
2188 case. We don't want the follow-fork-mode or 'catch fork'
2189 to interfere with this. */
2190
2191 /* This won't actually modify the breakpoint list, but will
2192 physically remove the breakpoints from the child. */
2193 detach_breakpoints (new_pid);
2194
2195 /* Retain child fork in ptrace (stopped) state. */
2196 if (!find_fork_pid (new_pid))
2197 add_fork (new_pid);
2198
2199 /* Report as spurious, so that infrun doesn't want to follow
2200 this fork. We're actually doing an infcall in
2201 linux-fork.c. */
2202 ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
2203 linux_enable_event_reporting (pid_to_ptid (new_pid));
2204
2205 /* Report the stop to the core. */
2206 return 0;
2207 }
2208
2209 if (event == PTRACE_EVENT_FORK)
2210 ourstatus->kind = TARGET_WAITKIND_FORKED;
2211 else if (event == PTRACE_EVENT_VFORK)
2212 ourstatus->kind = TARGET_WAITKIND_VFORKED;
2213 else
2214 {
2215 struct lwp_info *new_lp;
2216
2217 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2218
2219 new_lp = add_lwp (BUILD_LWP (new_pid, GET_PID (lp->ptid)));
2220 new_lp->cloned = 1;
2221 new_lp->stopped = 1;
2222
2223 if (WSTOPSIG (status) != SIGSTOP)
2224 {
2225 /* This can happen if someone starts sending signals to
2226 the new thread before it gets a chance to run, which
2227 have a lower number than SIGSTOP (e.g. SIGUSR1).
2228 This is an unlikely case, and harder to handle for
2229 fork / vfork than for clone, so we do not try - but
2230 we handle it for clone events here. We'll send
2231 the other signal on to the thread below. */
2232
2233 new_lp->signalled = 1;
2234 }
2235 else
2236 status = 0;
2237
2238 if (non_stop)
2239 {
2240 /* Add the new thread to GDB's lists as soon as possible
2241 so that:
2242
2243 1) the frontend doesn't have to wait for a stop to
2244 display them, and,
2245
2246 2) we tag it with the correct running state. */
2247
2248 /* If the thread_db layer is active, let it know about
2249 this new thread, and add it to GDB's list. */
2250 if (!thread_db_attach_lwp (new_lp->ptid))
2251 {
2252 /* We're not using thread_db. Add it to GDB's
2253 list. */
2254 target_post_attach (GET_LWP (new_lp->ptid));
2255 add_thread (new_lp->ptid);
2256 }
2257
2258 if (!stopping)
2259 {
2260 set_running (new_lp->ptid, 1);
2261 set_executing (new_lp->ptid, 1);
2262 }
2263 }
2264
2265 /* Note the need to use the low target ops to resume, to
2266 handle resuming with PT_SYSCALL if we have syscall
2267 catchpoints. */
2268 if (!stopping)
2269 {
2270 enum target_signal signo;
2271
2272 new_lp->stopped = 0;
2273 new_lp->resumed = 1;
2274
2275 signo = (status
2276 ? target_signal_from_host (WSTOPSIG (status))
2277 : TARGET_SIGNAL_0);
2278
2279 linux_ops->to_resume (linux_ops, pid_to_ptid (new_pid),
2280 0, signo);
2281 }
2282 else
2283 {
2284 if (status != 0)
2285 {
2286 /* We created NEW_LP so it cannot yet contain STATUS. */
2287 gdb_assert (new_lp->status == 0);
2288
2289 /* Save the wait status to report later. */
2290 if (debug_linux_nat)
2291 fprintf_unfiltered (gdb_stdlog,
2292 "LHEW: waitpid of new LWP %ld, "
2293 "saving status %s\n",
2294 (long) GET_LWP (new_lp->ptid),
2295 status_to_str (status));
2296 new_lp->status = status;
2297 }
2298 }
2299
2300 if (debug_linux_nat)
2301 fprintf_unfiltered (gdb_stdlog,
2302 "LHEW: Got clone event "
2303 "from LWP %ld, resuming\n",
2304 GET_LWP (lp->ptid));
2305 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
2306 0, TARGET_SIGNAL_0);
2307
2308 return 1;
2309 }
2310
2311 return 0;
2312 }
2313
2314 if (event == PTRACE_EVENT_EXEC)
2315 {
2316 if (debug_linux_nat)
2317 fprintf_unfiltered (gdb_stdlog,
2318 "LHEW: Got exec event from LWP %ld\n",
2319 GET_LWP (lp->ptid));
2320
2321 ourstatus->kind = TARGET_WAITKIND_EXECD;
2322 ourstatus->value.execd_pathname
2323 = xstrdup (linux_child_pid_to_exec_file (pid));
2324
2325 return 0;
2326 }
2327
2328 if (event == PTRACE_EVENT_VFORK_DONE)
2329 {
2330 if (current_inferior ()->waiting_for_vfork_done)
2331 {
2332 if (debug_linux_nat)
2333 fprintf_unfiltered (gdb_stdlog,
2334 "LHEW: Got expected PTRACE_EVENT_"
2335 "VFORK_DONE from LWP %ld: stopping\n",
2336 GET_LWP (lp->ptid));
2337
2338 ourstatus->kind = TARGET_WAITKIND_VFORK_DONE;
2339 return 0;
2340 }
2341
2342 if (debug_linux_nat)
2343 fprintf_unfiltered (gdb_stdlog,
2344 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2345 "from LWP %ld: resuming\n",
2346 GET_LWP (lp->ptid));
2347 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2348 return 1;
2349 }
2350
2351 internal_error (__FILE__, __LINE__,
2352 _("unknown ptrace event %d"), event);
2353 }
2354
2355 /* Return non-zero if LWP is a zombie. */
2356
2357 static int
2358 linux_lwp_is_zombie (long lwp)
2359 {
2360 char buffer[MAXPATHLEN];
2361 FILE *procfile;
2362 int retval = 0;
2363
2364 xsnprintf (buffer, sizeof (buffer), "/proc/%ld/status", lwp);
2365 procfile = fopen (buffer, "r");
2366 if (procfile == NULL)
2367 {
2368 warning (_("unable to open /proc file '%s'"), buffer);
2369 return 0;
2370 }
2371 while (fgets (buffer, sizeof (buffer), procfile) != NULL)
2372 if (strcmp (buffer, "State:\tZ (zombie)\n") == 0)
2373 {
2374 retval = 1;
2375 break;
2376 }
2377 fclose (procfile);
2378
2379 return retval;
2380 }
2381
2382 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2383 exited. */
2384
2385 static int
2386 wait_lwp (struct lwp_info *lp)
2387 {
2388 pid_t pid;
2389 int status = 0;
2390 int thread_dead = 0;
2391 sigset_t prev_mask;
2392
2393 gdb_assert (!lp->stopped);
2394 gdb_assert (lp->status == 0);
2395
2396 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2397 block_child_signals (&prev_mask);
2398
2399 for (;;)
2400 {
2401 /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind
2402 was right and we should just call sigsuspend. */
2403
2404 pid = my_waitpid (GET_LWP (lp->ptid), &status, WNOHANG);
2405 if (pid == -1 && errno == ECHILD)
2406 pid = my_waitpid (GET_LWP (lp->ptid), &status, __WCLONE | WNOHANG);
2407 if (pid != 0)
2408 break;
2409
2410 /* Bugs 10970, 12702.
2411 Thread group leader may have exited in which case we'll lock up in
2412 waitpid if there are other threads, even if they are all zombies too.
2413 Basically, we're not supposed to use waitpid this way.
2414 __WCLONE is not applicable for the leader so we can't use that.
2415 LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED
2416 process; it gets ESRCH both for the zombie and for running processes.
2417
2418 As a workaround, check if we're waiting for the thread group leader and
2419 if it's a zombie, and avoid calling waitpid if it is.
2420
2421 This is racy, what if the tgl becomes a zombie right after we check?
2422 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2423 waiting waitpid but the linux_lwp_is_zombie is safe this way. */
2424
2425 if (GET_PID (lp->ptid) == GET_LWP (lp->ptid)
2426 && linux_lwp_is_zombie (GET_LWP (lp->ptid)))
2427 {
2428 thread_dead = 1;
2429 if (debug_linux_nat)
2430 fprintf_unfiltered (gdb_stdlog,
2431 "WL: Thread group leader %s vanished.\n",
2432 target_pid_to_str (lp->ptid));
2433 break;
2434 }
2435
2436 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2437 get invoked despite our caller had them intentionally blocked by
2438 block_child_signals. This is sensitive only to the loop of
2439 linux_nat_wait_1 and there if we get called my_waitpid gets called
2440 again before it gets to sigsuspend so we can safely let the handlers
2441 get executed here. */
2442
2443 sigsuspend (&suspend_mask);
2444 }
2445
2446 restore_child_signals_mask (&prev_mask);
2447
2448 if (pid == -1 && errno == ECHILD)
2449 {
2450 /* The thread has previously exited. We need to delete it
2451 now because, for some vendor 2.4 kernels with NPTL
2452 support backported, there won't be an exit event unless
2453 it is the main thread. 2.6 kernels will report an exit
2454 event for each thread that exits, as expected. */
2455 thread_dead = 1;
2456 if (debug_linux_nat)
2457 fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
2458 target_pid_to_str (lp->ptid));
2459 }
2460
2461 if (!thread_dead)
2462 {
2463 gdb_assert (pid == GET_LWP (lp->ptid));
2464
2465 if (debug_linux_nat)
2466 {
2467 fprintf_unfiltered (gdb_stdlog,
2468 "WL: waitpid %s received %s\n",
2469 target_pid_to_str (lp->ptid),
2470 status_to_str (status));
2471 }
2472 }
2473
2474 /* Check if the thread has exited. */
2475 if (WIFEXITED (status) || WIFSIGNALED (status))
2476 {
2477 thread_dead = 1;
2478 if (debug_linux_nat)
2479 fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n",
2480 target_pid_to_str (lp->ptid));
2481 }
2482
2483 if (thread_dead)
2484 {
2485 exit_lwp (lp);
2486 return 0;
2487 }
2488
2489 gdb_assert (WIFSTOPPED (status));
2490
2491 /* Handle GNU/Linux's syscall SIGTRAPs. */
2492 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
2493 {
2494 /* No longer need the sysgood bit. The ptrace event ends up
2495 recorded in lp->waitstatus if we care for it. We can carry
2496 on handling the event like a regular SIGTRAP from here
2497 on. */
2498 status = W_STOPCODE (SIGTRAP);
2499 if (linux_handle_syscall_trap (lp, 1))
2500 return wait_lwp (lp);
2501 }
2502
2503 /* Handle GNU/Linux's extended waitstatus for trace events. */
2504 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
2505 {
2506 if (debug_linux_nat)
2507 fprintf_unfiltered (gdb_stdlog,
2508 "WL: Handling extended status 0x%06x\n",
2509 status);
2510 if (linux_handle_extended_wait (lp, status, 1))
2511 return wait_lwp (lp);
2512 }
2513
2514 return status;
2515 }
2516
2517 /* Save the most recent siginfo for LP. This is currently only called
2518 for SIGTRAP; some ports use the si_addr field for
2519 target_stopped_data_address. In the future, it may also be used to
2520 restore the siginfo of requeued signals. */
2521
2522 static void
2523 save_siginfo (struct lwp_info *lp)
2524 {
2525 errno = 0;
2526 ptrace (PTRACE_GETSIGINFO, GET_LWP (lp->ptid),
2527 (PTRACE_TYPE_ARG3) 0, &lp->siginfo);
2528
2529 if (errno != 0)
2530 memset (&lp->siginfo, 0, sizeof (lp->siginfo));
2531 }
2532
2533 /* Send a SIGSTOP to LP. */
2534
2535 static int
2536 stop_callback (struct lwp_info *lp, void *data)
2537 {
2538 if (!lp->stopped && !lp->signalled)
2539 {
2540 int ret;
2541
2542 if (debug_linux_nat)
2543 {
2544 fprintf_unfiltered (gdb_stdlog,
2545 "SC: kill %s **<SIGSTOP>**\n",
2546 target_pid_to_str (lp->ptid));
2547 }
2548 errno = 0;
2549 ret = kill_lwp (GET_LWP (lp->ptid), SIGSTOP);
2550 if (debug_linux_nat)
2551 {
2552 fprintf_unfiltered (gdb_stdlog,
2553 "SC: lwp kill %d %s\n",
2554 ret,
2555 errno ? safe_strerror (errno) : "ERRNO-OK");
2556 }
2557
2558 lp->signalled = 1;
2559 gdb_assert (lp->status == 0);
2560 }
2561
2562 return 0;
2563 }
2564
2565 /* Return non-zero if LWP PID has a pending SIGINT. */
2566
2567 static int
2568 linux_nat_has_pending_sigint (int pid)
2569 {
2570 sigset_t pending, blocked, ignored;
2571
2572 linux_proc_pending_signals (pid, &pending, &blocked, &ignored);
2573
2574 if (sigismember (&pending, SIGINT)
2575 && !sigismember (&ignored, SIGINT))
2576 return 1;
2577
2578 return 0;
2579 }
2580
2581 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2582
2583 static int
2584 set_ignore_sigint (struct lwp_info *lp, void *data)
2585 {
2586 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2587 flag to consume the next one. */
2588 if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status)
2589 && WSTOPSIG (lp->status) == SIGINT)
2590 lp->status = 0;
2591 else
2592 lp->ignore_sigint = 1;
2593
2594 return 0;
2595 }
2596
2597 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2598 This function is called after we know the LWP has stopped; if the LWP
2599 stopped before the expected SIGINT was delivered, then it will never have
2600 arrived. Also, if the signal was delivered to a shared queue and consumed
2601 by a different thread, it will never be delivered to this LWP. */
2602
2603 static void
2604 maybe_clear_ignore_sigint (struct lwp_info *lp)
2605 {
2606 if (!lp->ignore_sigint)
2607 return;
2608
2609 if (!linux_nat_has_pending_sigint (GET_LWP (lp->ptid)))
2610 {
2611 if (debug_linux_nat)
2612 fprintf_unfiltered (gdb_stdlog,
2613 "MCIS: Clearing bogus flag for %s\n",
2614 target_pid_to_str (lp->ptid));
2615 lp->ignore_sigint = 0;
2616 }
2617 }
2618
2619 /* Fetch the possible triggered data watchpoint info and store it in
2620 LP.
2621
2622 On some archs, like x86, that use debug registers to set
2623 watchpoints, it's possible that the way to know which watched
2624 address trapped, is to check the register that is used to select
2625 which address to watch. Problem is, between setting the watchpoint
2626 and reading back which data address trapped, the user may change
2627 the set of watchpoints, and, as a consequence, GDB changes the
2628 debug registers in the inferior. To avoid reading back a stale
2629 stopped-data-address when that happens, we cache in LP the fact
2630 that a watchpoint trapped, and the corresponding data address, as
2631 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2632 registers meanwhile, we have the cached data we can rely on. */
2633
2634 static void
2635 save_sigtrap (struct lwp_info *lp)
2636 {
2637 struct cleanup *old_chain;
2638
2639 if (linux_ops->to_stopped_by_watchpoint == NULL)
2640 {
2641 lp->stopped_by_watchpoint = 0;
2642 return;
2643 }
2644
2645 old_chain = save_inferior_ptid ();
2646 inferior_ptid = lp->ptid;
2647
2648 lp->stopped_by_watchpoint = linux_ops->to_stopped_by_watchpoint ();
2649
2650 if (lp->stopped_by_watchpoint)
2651 {
2652 if (linux_ops->to_stopped_data_address != NULL)
2653 lp->stopped_data_address_p =
2654 linux_ops->to_stopped_data_address (&current_target,
2655 &lp->stopped_data_address);
2656 else
2657 lp->stopped_data_address_p = 0;
2658 }
2659
2660 do_cleanups (old_chain);
2661 }
2662
2663 /* See save_sigtrap. */
2664
2665 static int
2666 linux_nat_stopped_by_watchpoint (void)
2667 {
2668 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2669
2670 gdb_assert (lp != NULL);
2671
2672 return lp->stopped_by_watchpoint;
2673 }
2674
2675 static int
2676 linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
2677 {
2678 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2679
2680 gdb_assert (lp != NULL);
2681
2682 *addr_p = lp->stopped_data_address;
2683
2684 return lp->stopped_data_address_p;
2685 }
2686
2687 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2688
2689 static int
2690 sigtrap_is_event (int status)
2691 {
2692 return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP;
2693 }
2694
2695 /* SIGTRAP-like events recognizer. */
2696
2697 static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event;
2698
2699 /* Check for SIGTRAP-like events in LP. */
2700
2701 static int
2702 linux_nat_lp_status_is_event (struct lwp_info *lp)
2703 {
2704 /* We check for lp->waitstatus in addition to lp->status, because we can
2705 have pending process exits recorded in lp->status
2706 and W_EXITCODE(0,0) == 0. We should probably have an additional
2707 lp->status_p flag. */
2708
2709 return (lp->waitstatus.kind == TARGET_WAITKIND_IGNORE
2710 && linux_nat_status_is_event (lp->status));
2711 }
2712
2713 /* Set alternative SIGTRAP-like events recognizer. If
2714 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2715 applied. */
2716
2717 void
2718 linux_nat_set_status_is_event (struct target_ops *t,
2719 int (*status_is_event) (int status))
2720 {
2721 linux_nat_status_is_event = status_is_event;
2722 }
2723
2724 /* Wait until LP is stopped. */
2725
2726 static int
2727 stop_wait_callback (struct lwp_info *lp, void *data)
2728 {
2729 struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid));
2730
2731 /* If this is a vfork parent, bail out, it is not going to report
2732 any SIGSTOP until the vfork is done with. */
2733 if (inf->vfork_child != NULL)
2734 return 0;
2735
2736 if (!lp->stopped)
2737 {
2738 int status;
2739
2740 status = wait_lwp (lp);
2741 if (status == 0)
2742 return 0;
2743
2744 if (lp->ignore_sigint && WIFSTOPPED (status)
2745 && WSTOPSIG (status) == SIGINT)
2746 {
2747 lp->ignore_sigint = 0;
2748
2749 errno = 0;
2750 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2751 if (debug_linux_nat)
2752 fprintf_unfiltered (gdb_stdlog,
2753 "PTRACE_CONT %s, 0, 0 (%s) "
2754 "(discarding SIGINT)\n",
2755 target_pid_to_str (lp->ptid),
2756 errno ? safe_strerror (errno) : "OK");
2757
2758 return stop_wait_callback (lp, NULL);
2759 }
2760
2761 maybe_clear_ignore_sigint (lp);
2762
2763 if (WSTOPSIG (status) != SIGSTOP)
2764 {
2765 if (linux_nat_status_is_event (status))
2766 {
2767 /* If a LWP other than the LWP that we're reporting an
2768 event for has hit a GDB breakpoint (as opposed to
2769 some random trap signal), then just arrange for it to
2770 hit it again later. We don't keep the SIGTRAP status
2771 and don't forward the SIGTRAP signal to the LWP. We
2772 will handle the current event, eventually we will
2773 resume all LWPs, and this one will get its breakpoint
2774 trap again.
2775
2776 If we do not do this, then we run the risk that the
2777 user will delete or disable the breakpoint, but the
2778 thread will have already tripped on it. */
2779
2780 /* Save the trap's siginfo in case we need it later. */
2781 save_siginfo (lp);
2782
2783 save_sigtrap (lp);
2784
2785 /* Now resume this LWP and get the SIGSTOP event. */
2786 errno = 0;
2787 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2788 if (debug_linux_nat)
2789 {
2790 fprintf_unfiltered (gdb_stdlog,
2791 "PTRACE_CONT %s, 0, 0 (%s)\n",
2792 target_pid_to_str (lp->ptid),
2793 errno ? safe_strerror (errno) : "OK");
2794
2795 fprintf_unfiltered (gdb_stdlog,
2796 "SWC: Candidate SIGTRAP event in %s\n",
2797 target_pid_to_str (lp->ptid));
2798 }
2799 /* Hold this event/waitstatus while we check to see if
2800 there are any more (we still want to get that SIGSTOP). */
2801 stop_wait_callback (lp, NULL);
2802
2803 /* Hold the SIGTRAP for handling by linux_nat_wait. If
2804 there's another event, throw it back into the
2805 queue. */
2806 if (lp->status)
2807 {
2808 if (debug_linux_nat)
2809 fprintf_unfiltered (gdb_stdlog,
2810 "SWC: kill %s, %s\n",
2811 target_pid_to_str (lp->ptid),
2812 status_to_str ((int) status));
2813 kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (lp->status));
2814 }
2815
2816 /* Save the sigtrap event. */
2817 lp->status = status;
2818 return 0;
2819 }
2820 else
2821 {
2822 /* The thread was stopped with a signal other than
2823 SIGSTOP, and didn't accidentally trip a breakpoint. */
2824
2825 if (debug_linux_nat)
2826 {
2827 fprintf_unfiltered (gdb_stdlog,
2828 "SWC: Pending event %s in %s\n",
2829 status_to_str ((int) status),
2830 target_pid_to_str (lp->ptid));
2831 }
2832 /* Now resume this LWP and get the SIGSTOP event. */
2833 errno = 0;
2834 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2835 if (debug_linux_nat)
2836 fprintf_unfiltered (gdb_stdlog,
2837 "SWC: PTRACE_CONT %s, 0, 0 (%s)\n",
2838 target_pid_to_str (lp->ptid),
2839 errno ? safe_strerror (errno) : "OK");
2840
2841 /* Hold this event/waitstatus while we check to see if
2842 there are any more (we still want to get that SIGSTOP). */
2843 stop_wait_callback (lp, NULL);
2844
2845 /* If the lp->status field is still empty, use it to
2846 hold this event. If not, then this event must be
2847 returned to the event queue of the LWP. */
2848 if (lp->status)
2849 {
2850 if (debug_linux_nat)
2851 {
2852 fprintf_unfiltered (gdb_stdlog,
2853 "SWC: kill %s, %s\n",
2854 target_pid_to_str (lp->ptid),
2855 status_to_str ((int) status));
2856 }
2857 kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (status));
2858 }
2859 else
2860 lp->status = status;
2861 return 0;
2862 }
2863 }
2864 else
2865 {
2866 /* We caught the SIGSTOP that we intended to catch, so
2867 there's no SIGSTOP pending. */
2868 lp->stopped = 1;
2869 lp->signalled = 0;
2870 }
2871 }
2872
2873 return 0;
2874 }
2875
2876 /* Return non-zero if LP has a wait status pending. */
2877
2878 static int
2879 status_callback (struct lwp_info *lp, void *data)
2880 {
2881 /* Only report a pending wait status if we pretend that this has
2882 indeed been resumed. */
2883 if (!lp->resumed)
2884 return 0;
2885
2886 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
2887 {
2888 /* A ptrace event, like PTRACE_FORK|VFORK|EXEC, syscall event,
2889 or a pending process exit. Note that `W_EXITCODE(0,0) ==
2890 0', so a clean process exit can not be stored pending in
2891 lp->status, it is indistinguishable from
2892 no-pending-status. */
2893 return 1;
2894 }
2895
2896 if (lp->status != 0)
2897 return 1;
2898
2899 return 0;
2900 }
2901
2902 /* Return non-zero if LP isn't stopped. */
2903
2904 static int
2905 running_callback (struct lwp_info *lp, void *data)
2906 {
2907 return (lp->stopped == 0 || (lp->status != 0 && lp->resumed));
2908 }
2909
2910 /* Count the LWP's that have had events. */
2911
2912 static int
2913 count_events_callback (struct lwp_info *lp, void *data)
2914 {
2915 int *count = data;
2916
2917 gdb_assert (count != NULL);
2918
2919 /* Count only resumed LWPs that have a SIGTRAP event pending. */
2920 if (lp->resumed && linux_nat_lp_status_is_event (lp))
2921 (*count)++;
2922
2923 return 0;
2924 }
2925
2926 /* Select the LWP (if any) that is currently being single-stepped. */
2927
2928 static int
2929 select_singlestep_lwp_callback (struct lwp_info *lp, void *data)
2930 {
2931 if (lp->step && lp->status != 0)
2932 return 1;
2933 else
2934 return 0;
2935 }
2936
2937 /* Select the Nth LWP that has had a SIGTRAP event. */
2938
2939 static int
2940 select_event_lwp_callback (struct lwp_info *lp, void *data)
2941 {
2942 int *selector = data;
2943
2944 gdb_assert (selector != NULL);
2945
2946 /* Select only resumed LWPs that have a SIGTRAP event pending. */
2947 if (lp->resumed && linux_nat_lp_status_is_event (lp))
2948 if ((*selector)-- == 0)
2949 return 1;
2950
2951 return 0;
2952 }
2953
2954 static int
2955 cancel_breakpoint (struct lwp_info *lp)
2956 {
2957 /* Arrange for a breakpoint to be hit again later. We don't keep
2958 the SIGTRAP status and don't forward the SIGTRAP signal to the
2959 LWP. We will handle the current event, eventually we will resume
2960 this LWP, and this breakpoint will trap again.
2961
2962 If we do not do this, then we run the risk that the user will
2963 delete or disable the breakpoint, but the LWP will have already
2964 tripped on it. */
2965
2966 struct regcache *regcache = get_thread_regcache (lp->ptid);
2967 struct gdbarch *gdbarch = get_regcache_arch (regcache);
2968 CORE_ADDR pc;
2969
2970 pc = regcache_read_pc (regcache) - gdbarch_decr_pc_after_break (gdbarch);
2971 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
2972 {
2973 if (debug_linux_nat)
2974 fprintf_unfiltered (gdb_stdlog,
2975 "CB: Push back breakpoint for %s\n",
2976 target_pid_to_str (lp->ptid));
2977
2978 /* Back up the PC if necessary. */
2979 if (gdbarch_decr_pc_after_break (gdbarch))
2980 regcache_write_pc (regcache, pc);
2981
2982 return 1;
2983 }
2984 return 0;
2985 }
2986
2987 static int
2988 cancel_breakpoints_callback (struct lwp_info *lp, void *data)
2989 {
2990 struct lwp_info *event_lp = data;
2991
2992 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
2993 if (lp == event_lp)
2994 return 0;
2995
2996 /* If a LWP other than the LWP that we're reporting an event for has
2997 hit a GDB breakpoint (as opposed to some random trap signal),
2998 then just arrange for it to hit it again later. We don't keep
2999 the SIGTRAP status and don't forward the SIGTRAP signal to the
3000 LWP. We will handle the current event, eventually we will resume
3001 all LWPs, and this one will get its breakpoint trap again.
3002
3003 If we do not do this, then we run the risk that the user will
3004 delete or disable the breakpoint, but the LWP will have already
3005 tripped on it. */
3006
3007 if (linux_nat_lp_status_is_event (lp)
3008 && cancel_breakpoint (lp))
3009 /* Throw away the SIGTRAP. */
3010 lp->status = 0;
3011
3012 return 0;
3013 }
3014
3015 /* Select one LWP out of those that have events pending. */
3016
3017 static void
3018 select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status)
3019 {
3020 int num_events = 0;
3021 int random_selector;
3022 struct lwp_info *event_lp;
3023
3024 /* Record the wait status for the original LWP. */
3025 (*orig_lp)->status = *status;
3026
3027 /* Give preference to any LWP that is being single-stepped. */
3028 event_lp = iterate_over_lwps (filter,
3029 select_singlestep_lwp_callback, NULL);
3030 if (event_lp != NULL)
3031 {
3032 if (debug_linux_nat)
3033 fprintf_unfiltered (gdb_stdlog,
3034 "SEL: Select single-step %s\n",
3035 target_pid_to_str (event_lp->ptid));
3036 }
3037 else
3038 {
3039 /* No single-stepping LWP. Select one at random, out of those
3040 which have had SIGTRAP events. */
3041
3042 /* First see how many SIGTRAP events we have. */
3043 iterate_over_lwps (filter, count_events_callback, &num_events);
3044
3045 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
3046 random_selector = (int)
3047 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
3048
3049 if (debug_linux_nat && num_events > 1)
3050 fprintf_unfiltered (gdb_stdlog,
3051 "SEL: Found %d SIGTRAP events, selecting #%d\n",
3052 num_events, random_selector);
3053
3054 event_lp = iterate_over_lwps (filter,
3055 select_event_lwp_callback,
3056 &random_selector);
3057 }
3058
3059 if (event_lp != NULL)
3060 {
3061 /* Switch the event LWP. */
3062 *orig_lp = event_lp;
3063 *status = event_lp->status;
3064 }
3065
3066 /* Flush the wait status for the event LWP. */
3067 (*orig_lp)->status = 0;
3068 }
3069
3070 /* Return non-zero if LP has been resumed. */
3071
3072 static int
3073 resumed_callback (struct lwp_info *lp, void *data)
3074 {
3075 return lp->resumed;
3076 }
3077
3078 /* Stop an active thread, verify it still exists, then resume it. */
3079
3080 static int
3081 stop_and_resume_callback (struct lwp_info *lp, void *data)
3082 {
3083 struct lwp_info *ptr;
3084
3085 if (!lp->stopped && !lp->signalled)
3086 {
3087 stop_callback (lp, NULL);
3088 stop_wait_callback (lp, NULL);
3089 /* Resume if the lwp still exists. */
3090 for (ptr = lwp_list; ptr; ptr = ptr->next)
3091 if (lp == ptr)
3092 {
3093 resume_callback (lp, NULL);
3094 resume_set_callback (lp, NULL);
3095 }
3096 }
3097 return 0;
3098 }
3099
3100 /* Check if we should go on and pass this event to common code.
3101 Return the affected lwp if we are, or NULL otherwise. */
3102 static struct lwp_info *
3103 linux_nat_filter_event (int lwpid, int status, int options)
3104 {
3105 struct lwp_info *lp;
3106
3107 lp = find_lwp_pid (pid_to_ptid (lwpid));
3108
3109 /* Check for stop events reported by a process we didn't already
3110 know about - anything not already in our LWP list.
3111
3112 If we're expecting to receive stopped processes after
3113 fork, vfork, and clone events, then we'll just add the
3114 new one to our list and go back to waiting for the event
3115 to be reported - the stopped process might be returned
3116 from waitpid before or after the event is. */
3117 if (WIFSTOPPED (status) && !lp)
3118 {
3119 linux_record_stopped_pid (lwpid, status);
3120 return NULL;
3121 }
3122
3123 /* Make sure we don't report an event for the exit of an LWP not in
3124 our list, i.e. not part of the current process. This can happen
3125 if we detach from a program we originally forked and then it
3126 exits. */
3127 if (!WIFSTOPPED (status) && !lp)
3128 return NULL;
3129
3130 /* NOTE drow/2003-06-17: This code seems to be meant for debugging
3131 CLONE_PTRACE processes which do not use the thread library -
3132 otherwise we wouldn't find the new LWP this way. That doesn't
3133 currently work, and the following code is currently unreachable
3134 due to the two blocks above. If it's fixed some day, this code
3135 should be broken out into a function so that we can also pick up
3136 LWPs from the new interface. */
3137 if (!lp)
3138 {
3139 lp = add_lwp (BUILD_LWP (lwpid, GET_PID (inferior_ptid)));
3140 if (options & __WCLONE)
3141 lp->cloned = 1;
3142
3143 gdb_assert (WIFSTOPPED (status)
3144 && WSTOPSIG (status) == SIGSTOP);
3145 lp->signalled = 1;
3146
3147 if (!in_thread_list (inferior_ptid))
3148 {
3149 inferior_ptid = BUILD_LWP (GET_PID (inferior_ptid),
3150 GET_PID (inferior_ptid));
3151 add_thread (inferior_ptid);
3152 }
3153
3154 add_thread (lp->ptid);
3155 }
3156
3157 /* Handle GNU/Linux's syscall SIGTRAPs. */
3158 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
3159 {
3160 /* No longer need the sysgood bit. The ptrace event ends up
3161 recorded in lp->waitstatus if we care for it. We can carry
3162 on handling the event like a regular SIGTRAP from here
3163 on. */
3164 status = W_STOPCODE (SIGTRAP);
3165 if (linux_handle_syscall_trap (lp, 0))
3166 return NULL;
3167 }
3168
3169 /* Handle GNU/Linux's extended waitstatus for trace events. */
3170 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
3171 {
3172 if (debug_linux_nat)
3173 fprintf_unfiltered (gdb_stdlog,
3174 "LLW: Handling extended status 0x%06x\n",
3175 status);
3176 if (linux_handle_extended_wait (lp, status, 0))
3177 return NULL;
3178 }
3179
3180 if (linux_nat_status_is_event (status))
3181 {
3182 /* Save the trap's siginfo in case we need it later. */
3183 save_siginfo (lp);
3184
3185 save_sigtrap (lp);
3186 }
3187
3188 /* Check if the thread has exited. */
3189 if ((WIFEXITED (status) || WIFSIGNALED (status))
3190 && num_lwps (GET_PID (lp->ptid)) > 1)
3191 {
3192 /* If this is the main thread, we must stop all threads and verify
3193 if they are still alive. This is because in the nptl thread model
3194 on Linux 2.4, there is no signal issued for exiting LWPs
3195 other than the main thread. We only get the main thread exit
3196 signal once all child threads have already exited. If we
3197 stop all the threads and use the stop_wait_callback to check
3198 if they have exited we can determine whether this signal
3199 should be ignored or whether it means the end of the debugged
3200 application, regardless of which threading model is being
3201 used. */
3202 if (GET_PID (lp->ptid) == GET_LWP (lp->ptid))
3203 {
3204 lp->stopped = 1;
3205 iterate_over_lwps (pid_to_ptid (GET_PID (lp->ptid)),
3206 stop_and_resume_callback, NULL);
3207 }
3208
3209 if (debug_linux_nat)
3210 fprintf_unfiltered (gdb_stdlog,
3211 "LLW: %s exited.\n",
3212 target_pid_to_str (lp->ptid));
3213
3214 if (num_lwps (GET_PID (lp->ptid)) > 1)
3215 {
3216 /* If there is at least one more LWP, then the exit signal
3217 was not the end of the debugged application and should be
3218 ignored. */
3219 exit_lwp (lp);
3220 return NULL;
3221 }
3222 }
3223
3224 /* Check if the current LWP has previously exited. In the nptl
3225 thread model, LWPs other than the main thread do not issue
3226 signals when they exit so we must check whenever the thread has
3227 stopped. A similar check is made in stop_wait_callback(). */
3228 if (num_lwps (GET_PID (lp->ptid)) > 1 && !linux_thread_alive (lp->ptid))
3229 {
3230 ptid_t ptid = pid_to_ptid (GET_PID (lp->ptid));
3231
3232 if (debug_linux_nat)
3233 fprintf_unfiltered (gdb_stdlog,
3234 "LLW: %s exited.\n",
3235 target_pid_to_str (lp->ptid));
3236
3237 exit_lwp (lp);
3238
3239 /* Make sure there is at least one thread running. */
3240 gdb_assert (iterate_over_lwps (ptid, running_callback, NULL));
3241
3242 /* Discard the event. */
3243 return NULL;
3244 }
3245
3246 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3247 an attempt to stop an LWP. */
3248 if (lp->signalled
3249 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP)
3250 {
3251 if (debug_linux_nat)
3252 fprintf_unfiltered (gdb_stdlog,
3253 "LLW: Delayed SIGSTOP caught for %s.\n",
3254 target_pid_to_str (lp->ptid));
3255
3256 /* This is a delayed SIGSTOP. */
3257 lp->signalled = 0;
3258
3259 registers_changed ();
3260
3261 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
3262 lp->step, TARGET_SIGNAL_0);
3263 if (debug_linux_nat)
3264 fprintf_unfiltered (gdb_stdlog,
3265 "LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
3266 lp->step ?
3267 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3268 target_pid_to_str (lp->ptid));
3269
3270 lp->stopped = 0;
3271 gdb_assert (lp->resumed);
3272
3273 /* Discard the event. */
3274 return NULL;
3275 }
3276
3277 /* Make sure we don't report a SIGINT that we have already displayed
3278 for another thread. */
3279 if (lp->ignore_sigint
3280 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT)
3281 {
3282 if (debug_linux_nat)
3283 fprintf_unfiltered (gdb_stdlog,
3284 "LLW: Delayed SIGINT caught for %s.\n",
3285 target_pid_to_str (lp->ptid));
3286
3287 /* This is a delayed SIGINT. */
3288 lp->ignore_sigint = 0;
3289
3290 registers_changed ();
3291 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
3292 lp->step, TARGET_SIGNAL_0);
3293 if (debug_linux_nat)
3294 fprintf_unfiltered (gdb_stdlog,
3295 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3296 lp->step ?
3297 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3298 target_pid_to_str (lp->ptid));
3299
3300 lp->stopped = 0;
3301 gdb_assert (lp->resumed);
3302
3303 /* Discard the event. */
3304 return NULL;
3305 }
3306
3307 /* An interesting event. */
3308 gdb_assert (lp);
3309 lp->status = status;
3310 return lp;
3311 }
3312
3313 static ptid_t
3314 linux_nat_wait_1 (struct target_ops *ops,
3315 ptid_t ptid, struct target_waitstatus *ourstatus,
3316 int target_options)
3317 {
3318 static sigset_t prev_mask;
3319 struct lwp_info *lp = NULL;
3320 int options = 0;
3321 int status = 0;
3322 pid_t pid;
3323
3324 if (debug_linux_nat)
3325 fprintf_unfiltered (gdb_stdlog, "LLW: enter\n");
3326
3327 /* The first time we get here after starting a new inferior, we may
3328 not have added it to the LWP list yet - this is the earliest
3329 moment at which we know its PID. */
3330 if (ptid_is_pid (inferior_ptid))
3331 {
3332 /* Upgrade the main thread's ptid. */
3333 thread_change_ptid (inferior_ptid,
3334 BUILD_LWP (GET_PID (inferior_ptid),
3335 GET_PID (inferior_ptid)));
3336
3337 lp = add_lwp (inferior_ptid);
3338 lp->resumed = 1;
3339 }
3340
3341 /* Make sure SIGCHLD is blocked. */
3342 block_child_signals (&prev_mask);
3343
3344 if (ptid_equal (ptid, minus_one_ptid))
3345 pid = -1;
3346 else if (ptid_is_pid (ptid))
3347 /* A request to wait for a specific tgid. This is not possible
3348 with waitpid, so instead, we wait for any child, and leave
3349 children we're not interested in right now with a pending
3350 status to report later. */
3351 pid = -1;
3352 else
3353 pid = GET_LWP (ptid);
3354
3355 retry:
3356 lp = NULL;
3357 status = 0;
3358
3359 /* Make sure that of those LWPs we want to get an event from, there
3360 is at least one LWP that has been resumed. If there's none, just
3361 bail out. The core may just be flushing asynchronously all
3362 events. */
3363 if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL)
3364 {
3365 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3366
3367 if (debug_linux_nat)
3368 fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n");
3369
3370 restore_child_signals_mask (&prev_mask);
3371 return minus_one_ptid;
3372 }
3373
3374 /* First check if there is a LWP with a wait status pending. */
3375 if (pid == -1)
3376 {
3377 /* Any LWP that's been resumed will do. */
3378 lp = iterate_over_lwps (ptid, status_callback, NULL);
3379 if (lp)
3380 {
3381 if (debug_linux_nat && lp->status)
3382 fprintf_unfiltered (gdb_stdlog,
3383 "LLW: Using pending wait status %s for %s.\n",
3384 status_to_str (lp->status),
3385 target_pid_to_str (lp->ptid));
3386 }
3387
3388 /* But if we don't find one, we'll have to wait, and check both
3389 cloned and uncloned processes. We start with the cloned
3390 processes. */
3391 options = __WCLONE | WNOHANG;
3392 }
3393 else if (is_lwp (ptid))
3394 {
3395 if (debug_linux_nat)
3396 fprintf_unfiltered (gdb_stdlog,
3397 "LLW: Waiting for specific LWP %s.\n",
3398 target_pid_to_str (ptid));
3399
3400 /* We have a specific LWP to check. */
3401 lp = find_lwp_pid (ptid);
3402 gdb_assert (lp);
3403
3404 if (debug_linux_nat && lp->status)
3405 fprintf_unfiltered (gdb_stdlog,
3406 "LLW: Using pending wait status %s for %s.\n",
3407 status_to_str (lp->status),
3408 target_pid_to_str (lp->ptid));
3409
3410 /* If we have to wait, take into account whether PID is a cloned
3411 process or not. And we have to convert it to something that
3412 the layer beneath us can understand. */
3413 options = lp->cloned ? __WCLONE : 0;
3414 pid = GET_LWP (ptid);
3415
3416 /* We check for lp->waitstatus in addition to lp->status,
3417 because we can have pending process exits recorded in
3418 lp->status and W_EXITCODE(0,0) == 0. We should probably have
3419 an additional lp->status_p flag. */
3420 if (lp->status == 0 && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE)
3421 lp = NULL;
3422 }
3423
3424 if (lp && lp->signalled)
3425 {
3426 /* A pending SIGSTOP may interfere with the normal stream of
3427 events. In a typical case where interference is a problem,
3428 we have a SIGSTOP signal pending for LWP A while
3429 single-stepping it, encounter an event in LWP B, and take the
3430 pending SIGSTOP while trying to stop LWP A. After processing
3431 the event in LWP B, LWP A is continued, and we'll never see
3432 the SIGTRAP associated with the last time we were
3433 single-stepping LWP A. */
3434
3435 /* Resume the thread. It should halt immediately returning the
3436 pending SIGSTOP. */
3437 registers_changed ();
3438 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
3439 lp->step, TARGET_SIGNAL_0);
3440 if (debug_linux_nat)
3441 fprintf_unfiltered (gdb_stdlog,
3442 "LLW: %s %s, 0, 0 (expect SIGSTOP)\n",
3443 lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3444 target_pid_to_str (lp->ptid));
3445 lp->stopped = 0;
3446 gdb_assert (lp->resumed);
3447
3448 /* Catch the pending SIGSTOP. */
3449 status = lp->status;
3450 lp->status = 0;
3451
3452 stop_wait_callback (lp, NULL);
3453
3454 /* If the lp->status field isn't empty, we caught another signal
3455 while flushing the SIGSTOP. Return it back to the event
3456 queue of the LWP, as we already have an event to handle. */
3457 if (lp->status)
3458 {
3459 if (debug_linux_nat)
3460 fprintf_unfiltered (gdb_stdlog,
3461 "LLW: kill %s, %s\n",
3462 target_pid_to_str (lp->ptid),
3463 status_to_str (lp->status));
3464 kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (lp->status));
3465 }
3466
3467 lp->status = status;
3468 }
3469
3470 if (!target_can_async_p ())
3471 {
3472 /* Causes SIGINT to be passed on to the attached process. */
3473 set_sigint_trap ();
3474 }
3475
3476 /* Translate generic target_wait options into waitpid options. */
3477 if (target_options & TARGET_WNOHANG)
3478 options |= WNOHANG;
3479
3480 while (lp == NULL)
3481 {
3482 pid_t lwpid;
3483
3484 lwpid = my_waitpid (pid, &status, options);
3485
3486 if (lwpid > 0)
3487 {
3488 gdb_assert (pid == -1 || lwpid == pid);
3489
3490 if (debug_linux_nat)
3491 {
3492 fprintf_unfiltered (gdb_stdlog,
3493 "LLW: waitpid %ld received %s\n",
3494 (long) lwpid, status_to_str (status));
3495 }
3496
3497 lp = linux_nat_filter_event (lwpid, status, options);
3498
3499 /* STATUS is now no longer valid, use LP->STATUS instead. */
3500 status = 0;
3501
3502 if (lp
3503 && ptid_is_pid (ptid)
3504 && ptid_get_pid (lp->ptid) != ptid_get_pid (ptid))
3505 {
3506 gdb_assert (lp->resumed);
3507
3508 if (debug_linux_nat)
3509 fprintf (stderr,
3510 "LWP %ld got an event %06x, leaving pending.\n",
3511 ptid_get_lwp (lp->ptid), lp->status);
3512
3513 if (WIFSTOPPED (lp->status))
3514 {
3515 if (WSTOPSIG (lp->status) != SIGSTOP)
3516 {
3517 /* Cancel breakpoint hits. The breakpoint may
3518 be removed before we fetch events from this
3519 process to report to the core. It is best
3520 not to assume the moribund breakpoints
3521 heuristic always handles these cases --- it
3522 could be too many events go through to the
3523 core before this one is handled. All-stop
3524 always cancels breakpoint hits in all
3525 threads. */
3526 if (non_stop
3527 && linux_nat_lp_status_is_event (lp)
3528 && cancel_breakpoint (lp))
3529 {
3530 /* Throw away the SIGTRAP. */
3531 lp->status = 0;
3532
3533 if (debug_linux_nat)
3534 fprintf (stderr,
3535 "LLW: LWP %ld hit a breakpoint while"
3536 " waiting for another process;"
3537 " cancelled it\n",
3538 ptid_get_lwp (lp->ptid));
3539 }
3540 lp->stopped = 1;
3541 }
3542 else
3543 {
3544 lp->stopped = 1;
3545 lp->signalled = 0;
3546 }
3547 }
3548 else if (WIFEXITED (lp->status) || WIFSIGNALED (lp->status))
3549 {
3550 if (debug_linux_nat)
3551 fprintf (stderr,
3552 "Process %ld exited while stopping LWPs\n",
3553 ptid_get_lwp (lp->ptid));
3554
3555 /* This was the last lwp in the process. Since
3556 events are serialized to GDB core, and we can't
3557 report this one right now, but GDB core and the
3558 other target layers will want to be notified
3559 about the exit code/signal, leave the status
3560 pending for the next time we're able to report
3561 it. */
3562
3563 /* Prevent trying to stop this thread again. We'll
3564 never try to resume it because it has a pending
3565 status. */
3566 lp->stopped = 1;
3567
3568 /* Dead LWP's aren't expected to reported a pending
3569 sigstop. */
3570 lp->signalled = 0;
3571
3572 /* Store the pending event in the waitstatus as
3573 well, because W_EXITCODE(0,0) == 0. */
3574 store_waitstatus (&lp->waitstatus, lp->status);
3575 }
3576
3577 /* Keep looking. */
3578 lp = NULL;
3579 continue;
3580 }
3581
3582 if (lp)
3583 break;
3584 else
3585 {
3586 if (pid == -1)
3587 {
3588 /* waitpid did return something. Restart over. */
3589 options |= __WCLONE;
3590 }
3591 continue;
3592 }
3593 }
3594
3595 if (pid == -1)
3596 {
3597 /* Alternate between checking cloned and uncloned processes. */
3598 options ^= __WCLONE;
3599
3600 /* And every time we have checked both:
3601 In async mode, return to event loop;
3602 In sync mode, suspend waiting for a SIGCHLD signal. */
3603 if (options & __WCLONE)
3604 {
3605 if (target_options & TARGET_WNOHANG)
3606 {
3607 /* No interesting event. */
3608 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3609
3610 if (debug_linux_nat)
3611 fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
3612
3613 restore_child_signals_mask (&prev_mask);
3614 return minus_one_ptid;
3615 }
3616
3617 sigsuspend (&suspend_mask);
3618 }
3619 }
3620 else if (target_options & TARGET_WNOHANG)
3621 {
3622 /* No interesting event for PID yet. */
3623 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3624
3625 if (debug_linux_nat)
3626 fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
3627
3628 restore_child_signals_mask (&prev_mask);
3629 return minus_one_ptid;
3630 }
3631
3632 /* We shouldn't end up here unless we want to try again. */
3633 gdb_assert (lp == NULL);
3634 }
3635
3636 if (!target_can_async_p ())
3637 clear_sigint_trap ();
3638
3639 gdb_assert (lp);
3640
3641 status = lp->status;
3642 lp->status = 0;
3643
3644 /* Don't report signals that GDB isn't interested in, such as
3645 signals that are neither printed nor stopped upon. Stopping all
3646 threads can be a bit time-consuming so if we want decent
3647 performance with heavily multi-threaded programs, especially when
3648 they're using a high frequency timer, we'd better avoid it if we
3649 can. */
3650
3651 if (WIFSTOPPED (status))
3652 {
3653 enum target_signal signo = target_signal_from_host (WSTOPSIG (status));
3654
3655 /* When using hardware single-step, we need to report every signal.
3656 Otherwise, signals in pass_mask may be short-circuited. */
3657 if (!lp->step
3658 && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status)))
3659 {
3660 /* FIMXE: kettenis/2001-06-06: Should we resume all threads
3661 here? It is not clear we should. GDB may not expect
3662 other threads to run. On the other hand, not resuming
3663 newly attached threads may cause an unwanted delay in
3664 getting them running. */
3665 registers_changed ();
3666 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
3667 lp->step, signo);
3668 if (debug_linux_nat)
3669 fprintf_unfiltered (gdb_stdlog,
3670 "LLW: %s %s, %s (preempt 'handle')\n",
3671 lp->step ?
3672 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3673 target_pid_to_str (lp->ptid),
3674 (signo != TARGET_SIGNAL_0
3675 ? strsignal (target_signal_to_host (signo))
3676 : "0"));
3677 lp->stopped = 0;
3678 goto retry;
3679 }
3680
3681 if (!non_stop)
3682 {
3683 /* Only do the below in all-stop, as we currently use SIGINT
3684 to implement target_stop (see linux_nat_stop) in
3685 non-stop. */
3686 if (signo == TARGET_SIGNAL_INT && signal_pass_state (signo) == 0)
3687 {
3688 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3689 forwarded to the entire process group, that is, all LWPs
3690 will receive it - unless they're using CLONE_THREAD to
3691 share signals. Since we only want to report it once, we
3692 mark it as ignored for all LWPs except this one. */
3693 iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid)),
3694 set_ignore_sigint, NULL);
3695 lp->ignore_sigint = 0;
3696 }
3697 else
3698 maybe_clear_ignore_sigint (lp);
3699 }
3700 }
3701
3702 /* This LWP is stopped now. */
3703 lp->stopped = 1;
3704
3705 if (debug_linux_nat)
3706 fprintf_unfiltered (gdb_stdlog, "LLW: Candidate event %s in %s.\n",
3707 status_to_str (status), target_pid_to_str (lp->ptid));
3708
3709 if (!non_stop)
3710 {
3711 /* Now stop all other LWP's ... */
3712 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
3713
3714 /* ... and wait until all of them have reported back that
3715 they're no longer running. */
3716 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
3717
3718 /* If we're not waiting for a specific LWP, choose an event LWP
3719 from among those that have had events. Giving equal priority
3720 to all LWPs that have had events helps prevent
3721 starvation. */
3722 if (pid == -1)
3723 select_event_lwp (ptid, &lp, &status);
3724
3725 /* Now that we've selected our final event LWP, cancel any
3726 breakpoints in other LWPs that have hit a GDB breakpoint.
3727 See the comment in cancel_breakpoints_callback to find out
3728 why. */
3729 iterate_over_lwps (minus_one_ptid, cancel_breakpoints_callback, lp);
3730
3731 /* In all-stop, from the core's perspective, all LWPs are now
3732 stopped until a new resume action is sent over. */
3733 iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL);
3734 }
3735 else
3736 lp->resumed = 0;
3737
3738 if (linux_nat_status_is_event (status))
3739 {
3740 if (debug_linux_nat)
3741 fprintf_unfiltered (gdb_stdlog,
3742 "LLW: trap ptid is %s.\n",
3743 target_pid_to_str (lp->ptid));
3744 }
3745
3746 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
3747 {
3748 *ourstatus = lp->waitstatus;
3749 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
3750 }
3751 else
3752 store_waitstatus (ourstatus, status);
3753
3754 if (debug_linux_nat)
3755 fprintf_unfiltered (gdb_stdlog, "LLW: exit\n");
3756
3757 restore_child_signals_mask (&prev_mask);
3758
3759 if (ourstatus->kind == TARGET_WAITKIND_EXITED
3760 || ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
3761 lp->core = -1;
3762 else
3763 lp->core = linux_nat_core_of_thread_1 (lp->ptid);
3764
3765 return lp->ptid;
3766 }
3767
3768 /* Resume LWPs that are currently stopped without any pending status
3769 to report, but are resumed from the core's perspective. */
3770
3771 static int
3772 resume_stopped_resumed_lwps (struct lwp_info *lp, void *data)
3773 {
3774 ptid_t *wait_ptid_p = data;
3775
3776 if (lp->stopped
3777 && lp->resumed
3778 && lp->status == 0
3779 && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE)
3780 {
3781 gdb_assert (is_executing (lp->ptid));
3782
3783 /* Don't bother if there's a breakpoint at PC that we'd hit
3784 immediately, and we're not waiting for this LWP. */
3785 if (!ptid_match (lp->ptid, *wait_ptid_p))
3786 {
3787 struct regcache *regcache = get_thread_regcache (lp->ptid);
3788 CORE_ADDR pc = regcache_read_pc (regcache);
3789
3790 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
3791 return 0;
3792 }
3793
3794 if (debug_linux_nat)
3795 fprintf_unfiltered (gdb_stdlog,
3796 "RSRL: resuming stopped-resumed LWP %s\n",
3797 target_pid_to_str (lp->ptid));
3798
3799 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
3800 lp->step, TARGET_SIGNAL_0);
3801 lp->stopped = 0;
3802 memset (&lp->siginfo, 0, sizeof (lp->siginfo));
3803 lp->stopped_by_watchpoint = 0;
3804 }
3805
3806 return 0;
3807 }
3808
3809 static ptid_t
3810 linux_nat_wait (struct target_ops *ops,
3811 ptid_t ptid, struct target_waitstatus *ourstatus,
3812 int target_options)
3813 {
3814 ptid_t event_ptid;
3815
3816 if (debug_linux_nat)
3817 fprintf_unfiltered (gdb_stdlog,
3818 "linux_nat_wait: [%s]\n", target_pid_to_str (ptid));
3819
3820 /* Flush the async file first. */
3821 if (target_can_async_p ())
3822 async_file_flush ();
3823
3824 /* Resume LWPs that are currently stopped without any pending status
3825 to report, but are resumed from the core's perspective. LWPs get
3826 in this state if we find them stopping at a time we're not
3827 interested in reporting the event (target_wait on a
3828 specific_process, for example, see linux_nat_wait_1), and
3829 meanwhile the event became uninteresting. Don't bother resuming
3830 LWPs we're not going to wait for if they'd stop immediately. */
3831 if (non_stop)
3832 iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid);
3833
3834 event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options);
3835
3836 /* If we requested any event, and something came out, assume there
3837 may be more. If we requested a specific lwp or process, also
3838 assume there may be more. */
3839 if (target_can_async_p ()
3840 && (ourstatus->kind != TARGET_WAITKIND_IGNORE
3841 || !ptid_equal (ptid, minus_one_ptid)))
3842 async_file_mark ();
3843
3844 /* Get ready for the next event. */
3845 if (target_can_async_p ())
3846 target_async (inferior_event_handler, 0);
3847
3848 return event_ptid;
3849 }
3850
3851 static int
3852 kill_callback (struct lwp_info *lp, void *data)
3853 {
3854 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3855
3856 errno = 0;
3857 kill (GET_LWP (lp->ptid), SIGKILL);
3858 if (debug_linux_nat)
3859 fprintf_unfiltered (gdb_stdlog,
3860 "KC: kill (SIGKILL) %s, 0, 0 (%s)\n",
3861 target_pid_to_str (lp->ptid),
3862 errno ? safe_strerror (errno) : "OK");
3863
3864 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3865
3866 errno = 0;
3867 ptrace (PTRACE_KILL, GET_LWP (lp->ptid), 0, 0);
3868 if (debug_linux_nat)
3869 fprintf_unfiltered (gdb_stdlog,
3870 "KC: PTRACE_KILL %s, 0, 0 (%s)\n",
3871 target_pid_to_str (lp->ptid),
3872 errno ? safe_strerror (errno) : "OK");
3873
3874 return 0;
3875 }
3876
3877 static int
3878 kill_wait_callback (struct lwp_info *lp, void *data)
3879 {
3880 pid_t pid;
3881
3882 /* We must make sure that there are no pending events (delayed
3883 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3884 program doesn't interfere with any following debugging session. */
3885
3886 /* For cloned processes we must check both with __WCLONE and
3887 without, since the exit status of a cloned process isn't reported
3888 with __WCLONE. */
3889 if (lp->cloned)
3890 {
3891 do
3892 {
3893 pid = my_waitpid (GET_LWP (lp->ptid), NULL, __WCLONE);
3894 if (pid != (pid_t) -1)
3895 {
3896 if (debug_linux_nat)
3897 fprintf_unfiltered (gdb_stdlog,
3898 "KWC: wait %s received unknown.\n",
3899 target_pid_to_str (lp->ptid));
3900 /* The Linux kernel sometimes fails to kill a thread
3901 completely after PTRACE_KILL; that goes from the stop
3902 point in do_fork out to the one in
3903 get_signal_to_deliever and waits again. So kill it
3904 again. */
3905 kill_callback (lp, NULL);
3906 }
3907 }
3908 while (pid == GET_LWP (lp->ptid));
3909
3910 gdb_assert (pid == -1 && errno == ECHILD);
3911 }
3912
3913 do
3914 {
3915 pid = my_waitpid (GET_LWP (lp->ptid), NULL, 0);
3916 if (pid != (pid_t) -1)
3917 {
3918 if (debug_linux_nat)
3919 fprintf_unfiltered (gdb_stdlog,
3920 "KWC: wait %s received unk.\n",
3921 target_pid_to_str (lp->ptid));
3922 /* See the call to kill_callback above. */
3923 kill_callback (lp, NULL);
3924 }
3925 }
3926 while (pid == GET_LWP (lp->ptid));
3927
3928 gdb_assert (pid == -1 && errno == ECHILD);
3929 return 0;
3930 }
3931
3932 static void
3933 linux_nat_kill (struct target_ops *ops)
3934 {
3935 struct target_waitstatus last;
3936 ptid_t last_ptid;
3937 int status;
3938
3939 /* If we're stopped while forking and we haven't followed yet,
3940 kill the other task. We need to do this first because the
3941 parent will be sleeping if this is a vfork. */
3942
3943 get_last_target_status (&last_ptid, &last);
3944
3945 if (last.kind == TARGET_WAITKIND_FORKED
3946 || last.kind == TARGET_WAITKIND_VFORKED)
3947 {
3948 ptrace (PT_KILL, PIDGET (last.value.related_pid), 0, 0);
3949 wait (&status);
3950 }
3951
3952 if (forks_exist_p ())
3953 linux_fork_killall ();
3954 else
3955 {
3956 ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
3957
3958 /* Stop all threads before killing them, since ptrace requires
3959 that the thread is stopped to sucessfully PTRACE_KILL. */
3960 iterate_over_lwps (ptid, stop_callback, NULL);
3961 /* ... and wait until all of them have reported back that
3962 they're no longer running. */
3963 iterate_over_lwps (ptid, stop_wait_callback, NULL);
3964
3965 /* Kill all LWP's ... */
3966 iterate_over_lwps (ptid, kill_callback, NULL);
3967
3968 /* ... and wait until we've flushed all events. */
3969 iterate_over_lwps (ptid, kill_wait_callback, NULL);
3970 }
3971
3972 target_mourn_inferior ();
3973 }
3974
3975 static void
3976 linux_nat_mourn_inferior (struct target_ops *ops)
3977 {
3978 purge_lwp_list (ptid_get_pid (inferior_ptid));
3979
3980 if (! forks_exist_p ())
3981 /* Normal case, no other forks available. */
3982 linux_ops->to_mourn_inferior (ops);
3983 else
3984 /* Multi-fork case. The current inferior_ptid has exited, but
3985 there are other viable forks to debug. Delete the exiting
3986 one and context-switch to the first available. */
3987 linux_fork_mourn_inferior ();
3988 }
3989
3990 /* Convert a native/host siginfo object, into/from the siginfo in the
3991 layout of the inferiors' architecture. */
3992
3993 static void
3994 siginfo_fixup (struct siginfo *siginfo, gdb_byte *inf_siginfo, int direction)
3995 {
3996 int done = 0;
3997
3998 if (linux_nat_siginfo_fixup != NULL)
3999 done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction);
4000
4001 /* If there was no callback, or the callback didn't do anything,
4002 then just do a straight memcpy. */
4003 if (!done)
4004 {
4005 if (direction == 1)
4006 memcpy (siginfo, inf_siginfo, sizeof (struct siginfo));
4007 else
4008 memcpy (inf_siginfo, siginfo, sizeof (struct siginfo));
4009 }
4010 }
4011
4012 static LONGEST
4013 linux_xfer_siginfo (struct target_ops *ops, enum target_object object,
4014 const char *annex, gdb_byte *readbuf,
4015 const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
4016 {
4017 int pid;
4018 struct siginfo siginfo;
4019 gdb_byte inf_siginfo[sizeof (struct siginfo)];
4020
4021 gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO);
4022 gdb_assert (readbuf || writebuf);
4023
4024 pid = GET_LWP (inferior_ptid);
4025 if (pid == 0)
4026 pid = GET_PID (inferior_ptid);
4027
4028 if (offset > sizeof (siginfo))
4029 return -1;
4030
4031 errno = 0;
4032 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
4033 if (errno != 0)
4034 return -1;
4035
4036 /* When GDB is built as a 64-bit application, ptrace writes into
4037 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
4038 inferior with a 64-bit GDB should look the same as debugging it
4039 with a 32-bit GDB, we need to convert it. GDB core always sees
4040 the converted layout, so any read/write will have to be done
4041 post-conversion. */
4042 siginfo_fixup (&siginfo, inf_siginfo, 0);
4043
4044 if (offset + len > sizeof (siginfo))
4045 len = sizeof (siginfo) - offset;
4046
4047 if (readbuf != NULL)
4048 memcpy (readbuf, inf_siginfo + offset, len);
4049 else
4050 {
4051 memcpy (inf_siginfo + offset, writebuf, len);
4052
4053 /* Convert back to ptrace layout before flushing it out. */
4054 siginfo_fixup (&siginfo, inf_siginfo, 1);
4055
4056 errno = 0;
4057 ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
4058 if (errno != 0)
4059 return -1;
4060 }
4061
4062 return len;
4063 }
4064
4065 static LONGEST
4066 linux_nat_xfer_partial (struct target_ops *ops, enum target_object object,
4067 const char *annex, gdb_byte *readbuf,
4068 const gdb_byte *writebuf,
4069 ULONGEST offset, LONGEST len)
4070 {
4071 struct cleanup *old_chain;
4072 LONGEST xfer;
4073
4074 if (object == TARGET_OBJECT_SIGNAL_INFO)
4075 return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf,
4076 offset, len);
4077
4078 /* The target is connected but no live inferior is selected. Pass
4079 this request down to a lower stratum (e.g., the executable
4080 file). */
4081 if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid))
4082 return 0;
4083
4084 old_chain = save_inferior_ptid ();
4085
4086 if (is_lwp (inferior_ptid))
4087 inferior_ptid = pid_to_ptid (GET_LWP (inferior_ptid));
4088
4089 xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf,
4090 offset, len);
4091
4092 do_cleanups (old_chain);
4093 return xfer;
4094 }
4095
4096 static int
4097 linux_thread_alive (ptid_t ptid)
4098 {
4099 int err, tmp_errno;
4100
4101 gdb_assert (is_lwp (ptid));
4102
4103 /* Send signal 0 instead of anything ptrace, because ptracing a
4104 running thread errors out claiming that the thread doesn't
4105 exist. */
4106 err = kill_lwp (GET_LWP (ptid), 0);
4107 tmp_errno = errno;
4108 if (debug_linux_nat)
4109 fprintf_unfiltered (gdb_stdlog,
4110 "LLTA: KILL(SIG0) %s (%s)\n",
4111 target_pid_to_str (ptid),
4112 err ? safe_strerror (tmp_errno) : "OK");
4113
4114 if (err != 0)
4115 return 0;
4116
4117 return 1;
4118 }
4119
4120 static int
4121 linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid)
4122 {
4123 return linux_thread_alive (ptid);
4124 }
4125
4126 static char *
4127 linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid)
4128 {
4129 static char buf[64];
4130
4131 if (is_lwp (ptid)
4132 && (GET_PID (ptid) != GET_LWP (ptid)
4133 || num_lwps (GET_PID (ptid)) > 1))
4134 {
4135 snprintf (buf, sizeof (buf), "LWP %ld", GET_LWP (ptid));
4136 return buf;
4137 }
4138
4139 return normal_pid_to_str (ptid);
4140 }
4141
4142 static char *
4143 linux_nat_thread_name (struct thread_info *thr)
4144 {
4145 int pid = ptid_get_pid (thr->ptid);
4146 long lwp = ptid_get_lwp (thr->ptid);
4147 #define FORMAT "/proc/%d/task/%ld/comm"
4148 char buf[sizeof (FORMAT) + 30];
4149 FILE *comm_file;
4150 char *result = NULL;
4151
4152 snprintf (buf, sizeof (buf), FORMAT, pid, lwp);
4153 comm_file = fopen (buf, "r");
4154 if (comm_file)
4155 {
4156 /* Not exported by the kernel, so we define it here. */
4157 #define COMM_LEN 16
4158 static char line[COMM_LEN + 1];
4159
4160 if (fgets (line, sizeof (line), comm_file))
4161 {
4162 char *nl = strchr (line, '\n');
4163
4164 if (nl)
4165 *nl = '\0';
4166 if (*line != '\0')
4167 result = line;
4168 }
4169
4170 fclose (comm_file);
4171 }
4172
4173 #undef COMM_LEN
4174 #undef FORMAT
4175
4176 return result;
4177 }
4178
4179 /* Accepts an integer PID; Returns a string representing a file that
4180 can be opened to get the symbols for the child process. */
4181
4182 static char *
4183 linux_child_pid_to_exec_file (int pid)
4184 {
4185 char *name1, *name2;
4186
4187 name1 = xmalloc (MAXPATHLEN);
4188 name2 = xmalloc (MAXPATHLEN);
4189 make_cleanup (xfree, name1);
4190 make_cleanup (xfree, name2);
4191 memset (name2, 0, MAXPATHLEN);
4192
4193 sprintf (name1, "/proc/%d/exe", pid);
4194 if (readlink (name1, name2, MAXPATHLEN) > 0)
4195 return name2;
4196 else
4197 return name1;
4198 }
4199
4200 /* Service function for corefiles and info proc. */
4201
4202 static int
4203 read_mapping (FILE *mapfile,
4204 long long *addr,
4205 long long *endaddr,
4206 char *permissions,
4207 long long *offset,
4208 char *device, long long *inode, char *filename)
4209 {
4210 int ret = fscanf (mapfile, "%llx-%llx %s %llx %s %llx",
4211 addr, endaddr, permissions, offset, device, inode);
4212
4213 filename[0] = '\0';
4214 if (ret > 0 && ret != EOF)
4215 {
4216 /* Eat everything up to EOL for the filename. This will prevent
4217 weird filenames (such as one with embedded whitespace) from
4218 confusing this code. It also makes this code more robust in
4219 respect to annotations the kernel may add after the filename.
4220
4221 Note the filename is used for informational purposes
4222 only. */
4223 ret += fscanf (mapfile, "%[^\n]\n", filename);
4224 }
4225
4226 return (ret != 0 && ret != EOF);
4227 }
4228
4229 /* Fills the "to_find_memory_regions" target vector. Lists the memory
4230 regions in the inferior for a corefile. */
4231
4232 static int
4233 linux_nat_find_memory_regions (find_memory_region_ftype func, void *obfd)
4234 {
4235 int pid = PIDGET (inferior_ptid);
4236 char mapsfilename[MAXPATHLEN];
4237 FILE *mapsfile;
4238 long long addr, endaddr, size, offset, inode;
4239 char permissions[8], device[8], filename[MAXPATHLEN];
4240 int read, write, exec;
4241 struct cleanup *cleanup;
4242
4243 /* Compose the filename for the /proc memory map, and open it. */
4244 sprintf (mapsfilename, "/proc/%d/maps", pid);
4245 if ((mapsfile = fopen (mapsfilename, "r")) == NULL)
4246 error (_("Could not open %s."), mapsfilename);
4247 cleanup = make_cleanup_fclose (mapsfile);
4248
4249 if (info_verbose)
4250 fprintf_filtered (gdb_stdout,
4251 "Reading memory regions from %s\n", mapsfilename);
4252
4253 /* Now iterate until end-of-file. */
4254 while (read_mapping (mapsfile, &addr, &endaddr, &permissions[0],
4255 &offset, &device[0], &inode, &filename[0]))
4256 {
4257 size = endaddr - addr;
4258
4259 /* Get the segment's permissions. */
4260 read = (strchr (permissions, 'r') != 0);
4261 write = (strchr (permissions, 'w') != 0);
4262 exec = (strchr (permissions, 'x') != 0);
4263
4264 if (info_verbose)
4265 {
4266 fprintf_filtered (gdb_stdout,
4267 "Save segment, %s bytes at %s (%c%c%c)",
4268 plongest (size), paddress (target_gdbarch, addr),
4269 read ? 'r' : ' ',
4270 write ? 'w' : ' ', exec ? 'x' : ' ');
4271 if (filename[0])
4272 fprintf_filtered (gdb_stdout, " for %s", filename);
4273 fprintf_filtered (gdb_stdout, "\n");
4274 }
4275
4276 /* Invoke the callback function to create the corefile
4277 segment. */
4278 func (addr, size, read, write, exec, obfd);
4279 }
4280 do_cleanups (cleanup);
4281 return 0;
4282 }
4283
4284 static int
4285 find_signalled_thread (struct thread_info *info, void *data)
4286 {
4287 if (info->suspend.stop_signal != TARGET_SIGNAL_0
4288 && ptid_get_pid (info->ptid) == ptid_get_pid (inferior_ptid))
4289 return 1;
4290
4291 return 0;
4292 }
4293
4294 static enum target_signal
4295 find_stop_signal (void)
4296 {
4297 struct thread_info *info =
4298 iterate_over_threads (find_signalled_thread, NULL);
4299
4300 if (info)
4301 return info->suspend.stop_signal;
4302 else
4303 return TARGET_SIGNAL_0;
4304 }
4305
4306 /* Records the thread's register state for the corefile note
4307 section. */
4308
4309 static char *
4310 linux_nat_do_thread_registers (bfd *obfd, ptid_t ptid,
4311 char *note_data, int *note_size,
4312 enum target_signal stop_signal)
4313 {
4314 unsigned long lwp = ptid_get_lwp (ptid);
4315 struct gdbarch *gdbarch = target_gdbarch;
4316 struct regcache *regcache = get_thread_arch_regcache (ptid, gdbarch);
4317 const struct regset *regset;
4318 int core_regset_p;
4319 struct cleanup *old_chain;
4320 struct core_regset_section *sect_list;
4321 char *gdb_regset;
4322
4323 old_chain = save_inferior_ptid ();
4324 inferior_ptid = ptid;
4325 target_fetch_registers (regcache, -1);
4326 do_cleanups (old_chain);
4327
4328 core_regset_p = gdbarch_regset_from_core_section_p (gdbarch);
4329 sect_list = gdbarch_core_regset_sections (gdbarch);
4330
4331 /* The loop below uses the new struct core_regset_section, which stores
4332 the supported section names and sizes for the core file. Note that
4333 note PRSTATUS needs to be treated specially. But the other notes are
4334 structurally the same, so they can benefit from the new struct. */
4335 if (core_regset_p && sect_list != NULL)
4336 while (sect_list->sect_name != NULL)
4337 {
4338 regset = gdbarch_regset_from_core_section (gdbarch,
4339 sect_list->sect_name,
4340 sect_list->size);
4341 gdb_assert (regset && regset->collect_regset);
4342 gdb_regset = xmalloc (sect_list->size);
4343 regset->collect_regset (regset, regcache, -1,
4344 gdb_regset, sect_list->size);
4345
4346 if (strcmp (sect_list->sect_name, ".reg") == 0)
4347 note_data = (char *) elfcore_write_prstatus
4348 (obfd, note_data, note_size,
4349 lwp, target_signal_to_host (stop_signal),
4350 gdb_regset);
4351 else
4352 note_data = (char *) elfcore_write_register_note
4353 (obfd, note_data, note_size,
4354 sect_list->sect_name, gdb_regset,
4355 sect_list->size);
4356 xfree (gdb_regset);
4357 sect_list++;
4358 }
4359
4360 /* For architectures that does not have the struct core_regset_section
4361 implemented, we use the old method. When all the architectures have
4362 the new support, the code below should be deleted. */
4363 else
4364 {
4365 gdb_gregset_t gregs;
4366 gdb_fpregset_t fpregs;
4367
4368 if (core_regset_p
4369 && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg",
4370 sizeof (gregs)))
4371 != NULL && regset->collect_regset != NULL)
4372 regset->collect_regset (regset, regcache, -1,
4373 &gregs, sizeof (gregs));
4374 else
4375 fill_gregset (regcache, &gregs, -1);
4376
4377 note_data = (char *) elfcore_write_prstatus
4378 (obfd, note_data, note_size, lwp, target_signal_to_host (stop_signal),
4379 &gregs);
4380
4381 if (core_regset_p
4382 && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg2",
4383 sizeof (fpregs)))
4384 != NULL && regset->collect_regset != NULL)
4385 regset->collect_regset (regset, regcache, -1,
4386 &fpregs, sizeof (fpregs));
4387 else
4388 fill_fpregset (regcache, &fpregs, -1);
4389
4390 note_data = (char *) elfcore_write_prfpreg (obfd,
4391 note_data,
4392 note_size,
4393 &fpregs, sizeof (fpregs));
4394 }
4395
4396 return note_data;
4397 }
4398
4399 struct linux_nat_corefile_thread_data
4400 {
4401 bfd *obfd;
4402 char *note_data;
4403 int *note_size;
4404 int num_notes;
4405 enum target_signal stop_signal;
4406 };
4407
4408 /* Called by gdbthread.c once per thread. Records the thread's
4409 register state for the corefile note section. */
4410
4411 static int
4412 linux_nat_corefile_thread_callback (struct lwp_info *ti, void *data)
4413 {
4414 struct linux_nat_corefile_thread_data *args = data;
4415
4416 args->note_data = linux_nat_do_thread_registers (args->obfd,
4417 ti->ptid,
4418 args->note_data,
4419 args->note_size,
4420 args->stop_signal);
4421 args->num_notes++;
4422
4423 return 0;
4424 }
4425
4426 /* Enumerate spufs IDs for process PID. */
4427
4428 static void
4429 iterate_over_spus (int pid, void (*callback) (void *, int), void *data)
4430 {
4431 char path[128];
4432 DIR *dir;
4433 struct dirent *entry;
4434
4435 xsnprintf (path, sizeof path, "/proc/%d/fd", pid);
4436 dir = opendir (path);
4437 if (!dir)
4438 return;
4439
4440 rewinddir (dir);
4441 while ((entry = readdir (dir)) != NULL)
4442 {
4443 struct stat st;
4444 struct statfs stfs;
4445 int fd;
4446
4447 fd = atoi (entry->d_name);
4448 if (!fd)
4449 continue;
4450
4451 xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd);
4452 if (stat (path, &st) != 0)
4453 continue;
4454 if (!S_ISDIR (st.st_mode))
4455 continue;
4456
4457 if (statfs (path, &stfs) != 0)
4458 continue;
4459 if (stfs.f_type != SPUFS_MAGIC)
4460 continue;
4461
4462 callback (data, fd);
4463 }
4464
4465 closedir (dir);
4466 }
4467
4468 /* Generate corefile notes for SPU contexts. */
4469
4470 struct linux_spu_corefile_data
4471 {
4472 bfd *obfd;
4473 char *note_data;
4474 int *note_size;
4475 };
4476
4477 static void
4478 linux_spu_corefile_callback (void *data, int fd)
4479 {
4480 struct linux_spu_corefile_data *args = data;
4481 int i;
4482
4483 static const char *spu_files[] =
4484 {
4485 "object-id",
4486 "mem",
4487 "regs",
4488 "fpcr",
4489 "lslr",
4490 "decr",
4491 "decr_status",
4492 "signal1",
4493 "signal1_type",
4494 "signal2",
4495 "signal2_type",
4496 "event_mask",
4497 "event_status",
4498 "mbox_info",
4499 "ibox_info",
4500 "wbox_info",
4501 "dma_info",
4502 "proxydma_info",
4503 };
4504
4505 for (i = 0; i < sizeof (spu_files) / sizeof (spu_files[0]); i++)
4506 {
4507 char annex[32], note_name[32];
4508 gdb_byte *spu_data;
4509 LONGEST spu_len;
4510
4511 xsnprintf (annex, sizeof annex, "%d/%s", fd, spu_files[i]);
4512 spu_len = target_read_alloc (&current_target, TARGET_OBJECT_SPU,
4513 annex, &spu_data);
4514 if (spu_len > 0)
4515 {
4516 xsnprintf (note_name, sizeof note_name, "SPU/%s", annex);
4517 args->note_data = elfcore_write_note (args->obfd, args->note_data,
4518 args->note_size, note_name,
4519 NT_SPU, spu_data, spu_len);
4520 xfree (spu_data);
4521 }
4522 }
4523 }
4524
4525 static char *
4526 linux_spu_make_corefile_notes (bfd *obfd, char *note_data, int *note_size)
4527 {
4528 struct linux_spu_corefile_data args;
4529
4530 args.obfd = obfd;
4531 args.note_data = note_data;
4532 args.note_size = note_size;
4533
4534 iterate_over_spus (PIDGET (inferior_ptid),
4535 linux_spu_corefile_callback, &args);
4536
4537 return args.note_data;
4538 }
4539
4540 /* Fills the "to_make_corefile_note" target vector. Builds the note
4541 section for a corefile, and returns it in a malloc buffer. */
4542
4543 static char *
4544 linux_nat_make_corefile_notes (bfd *obfd, int *note_size)
4545 {
4546 struct linux_nat_corefile_thread_data thread_args;
4547 /* The variable size must be >= sizeof (prpsinfo_t.pr_fname). */
4548 char fname[16] = { '\0' };
4549 /* The variable size must be >= sizeof (prpsinfo_t.pr_psargs). */
4550 char psargs[80] = { '\0' };
4551 char *note_data = NULL;
4552 ptid_t filter = pid_to_ptid (ptid_get_pid (inferior_ptid));
4553 gdb_byte *auxv;
4554 int auxv_len;
4555
4556 if (get_exec_file (0))
4557 {
4558 strncpy (fname, lbasename (get_exec_file (0)), sizeof (fname));
4559 strncpy (psargs, get_exec_file (0), sizeof (psargs));
4560 if (get_inferior_args ())
4561 {
4562 char *string_end;
4563 char *psargs_end = psargs + sizeof (psargs);
4564
4565 /* linux_elfcore_write_prpsinfo () handles zero unterminated
4566 strings fine. */
4567 string_end = memchr (psargs, 0, sizeof (psargs));
4568 if (string_end != NULL)
4569 {
4570 *string_end++ = ' ';
4571 strncpy (string_end, get_inferior_args (),
4572 psargs_end - string_end);
4573 }
4574 }
4575 note_data = (char *) elfcore_write_prpsinfo (obfd,
4576 note_data,
4577 note_size, fname, psargs);
4578 }
4579
4580 /* Dump information for threads. */
4581 thread_args.obfd = obfd;
4582 thread_args.note_data = note_data;
4583 thread_args.note_size = note_size;
4584 thread_args.num_notes = 0;
4585 thread_args.stop_signal = find_stop_signal ();
4586 iterate_over_lwps (filter, linux_nat_corefile_thread_callback, &thread_args);
4587 gdb_assert (thread_args.num_notes != 0);
4588 note_data = thread_args.note_data;
4589
4590 auxv_len = target_read_alloc (&current_target, TARGET_OBJECT_AUXV,
4591 NULL, &auxv);
4592 if (auxv_len > 0)
4593 {
4594 note_data = elfcore_write_note (obfd, note_data, note_size,
4595 "CORE", NT_AUXV, auxv, auxv_len);
4596 xfree (auxv);
4597 }
4598
4599 note_data = linux_spu_make_corefile_notes (obfd, note_data, note_size);
4600
4601 make_cleanup (xfree, note_data);
4602 return note_data;
4603 }
4604
4605 /* Implement the "info proc" command. */
4606
4607 static void
4608 linux_nat_info_proc_cmd (char *args, int from_tty)
4609 {
4610 /* A long is used for pid instead of an int to avoid a loss of precision
4611 compiler warning from the output of strtoul. */
4612 long pid = PIDGET (inferior_ptid);
4613 FILE *procfile;
4614 char **argv = NULL;
4615 char buffer[MAXPATHLEN];
4616 char fname1[MAXPATHLEN], fname2[MAXPATHLEN];
4617 int cmdline_f = 1;
4618 int cwd_f = 1;
4619 int exe_f = 1;
4620 int mappings_f = 0;
4621 int status_f = 0;
4622 int stat_f = 0;
4623 int all = 0;
4624 struct stat dummy;
4625
4626 if (args)
4627 {
4628 /* Break up 'args' into an argv array. */
4629 argv = gdb_buildargv (args);
4630 make_cleanup_freeargv (argv);
4631 }
4632 while (argv != NULL && *argv != NULL)
4633 {
4634 if (isdigit (argv[0][0]))
4635 {
4636 pid = strtoul (argv[0], NULL, 10);
4637 }
4638 else if (strncmp (argv[0], "mappings", strlen (argv[0])) == 0)
4639 {
4640 mappings_f = 1;
4641 }
4642 else if (strcmp (argv[0], "status") == 0)
4643 {
4644 status_f = 1;
4645 }
4646 else if (strcmp (argv[0], "stat") == 0)
4647 {
4648 stat_f = 1;
4649 }
4650 else if (strcmp (argv[0], "cmd") == 0)
4651 {
4652 cmdline_f = 1;
4653 }
4654 else if (strncmp (argv[0], "exe", strlen (argv[0])) == 0)
4655 {
4656 exe_f = 1;
4657 }
4658 else if (strcmp (argv[0], "cwd") == 0)
4659 {
4660 cwd_f = 1;
4661 }
4662 else if (strncmp (argv[0], "all", strlen (argv[0])) == 0)
4663 {
4664 all = 1;
4665 }
4666 else
4667 {
4668 /* [...] (future options here). */
4669 }
4670 argv++;
4671 }
4672 if (pid == 0)
4673 error (_("No current process: you must name one."));
4674
4675 sprintf (fname1, "/proc/%ld", pid);
4676 if (stat (fname1, &dummy) != 0)
4677 error (_("No /proc directory: '%s'"), fname1);
4678
4679 printf_filtered (_("process %ld\n"), pid);
4680 if (cmdline_f || all)
4681 {
4682 sprintf (fname1, "/proc/%ld/cmdline", pid);
4683 if ((procfile = fopen (fname1, "r")) != NULL)
4684 {
4685 struct cleanup *cleanup = make_cleanup_fclose (procfile);
4686
4687 if (fgets (buffer, sizeof (buffer), procfile))
4688 printf_filtered ("cmdline = '%s'\n", buffer);
4689 else
4690 warning (_("unable to read '%s'"), fname1);
4691 do_cleanups (cleanup);
4692 }
4693 else
4694 warning (_("unable to open /proc file '%s'"), fname1);
4695 }
4696 if (cwd_f || all)
4697 {
4698 sprintf (fname1, "/proc/%ld/cwd", pid);
4699 memset (fname2, 0, sizeof (fname2));
4700 if (readlink (fname1, fname2, sizeof (fname2)) > 0)
4701 printf_filtered ("cwd = '%s'\n", fname2);
4702 else
4703 warning (_("unable to read link '%s'"), fname1);
4704 }
4705 if (exe_f || all)
4706 {
4707 sprintf (fname1, "/proc/%ld/exe", pid);
4708 memset (fname2, 0, sizeof (fname2));
4709 if (readlink (fname1, fname2, sizeof (fname2)) > 0)
4710 printf_filtered ("exe = '%s'\n", fname2);
4711 else
4712 warning (_("unable to read link '%s'"), fname1);
4713 }
4714 if (mappings_f || all)
4715 {
4716 sprintf (fname1, "/proc/%ld/maps", pid);
4717 if ((procfile = fopen (fname1, "r")) != NULL)
4718 {
4719 long long addr, endaddr, size, offset, inode;
4720 char permissions[8], device[8], filename[MAXPATHLEN];
4721 struct cleanup *cleanup;
4722
4723 cleanup = make_cleanup_fclose (procfile);
4724 printf_filtered (_("Mapped address spaces:\n\n"));
4725 if (gdbarch_addr_bit (target_gdbarch) == 32)
4726 {
4727 printf_filtered ("\t%10s %10s %10s %10s %7s\n",
4728 "Start Addr",
4729 " End Addr",
4730 " Size", " Offset", "objfile");
4731 }
4732 else
4733 {
4734 printf_filtered (" %18s %18s %10s %10s %7s\n",
4735 "Start Addr",
4736 " End Addr",
4737 " Size", " Offset", "objfile");
4738 }
4739
4740 while (read_mapping (procfile, &addr, &endaddr, &permissions[0],
4741 &offset, &device[0], &inode, &filename[0]))
4742 {
4743 size = endaddr - addr;
4744
4745 /* FIXME: carlton/2003-08-27: Maybe the printf_filtered
4746 calls here (and possibly above) should be abstracted
4747 out into their own functions? Andrew suggests using
4748 a generic local_address_string instead to print out
4749 the addresses; that makes sense to me, too. */
4750
4751 if (gdbarch_addr_bit (target_gdbarch) == 32)
4752 {
4753 printf_filtered ("\t%#10lx %#10lx %#10x %#10x %7s\n",
4754 (unsigned long) addr, /* FIXME: pr_addr */
4755 (unsigned long) endaddr,
4756 (int) size,
4757 (unsigned int) offset,
4758 filename[0] ? filename : "");
4759 }
4760 else
4761 {
4762 printf_filtered (" %#18lx %#18lx %#10x %#10x %7s\n",
4763 (unsigned long) addr, /* FIXME: pr_addr */
4764 (unsigned long) endaddr,
4765 (int) size,
4766 (unsigned int) offset,
4767 filename[0] ? filename : "");
4768 }
4769 }
4770
4771 do_cleanups (cleanup);
4772 }
4773 else
4774 warning (_("unable to open /proc file '%s'"), fname1);
4775 }
4776 if (status_f || all)
4777 {
4778 sprintf (fname1, "/proc/%ld/status", pid);
4779 if ((procfile = fopen (fname1, "r")) != NULL)
4780 {
4781 struct cleanup *cleanup = make_cleanup_fclose (procfile);
4782
4783 while (fgets (buffer, sizeof (buffer), procfile) != NULL)
4784 puts_filtered (buffer);
4785 do_cleanups (cleanup);
4786 }
4787 else
4788 warning (_("unable to open /proc file '%s'"), fname1);
4789 }
4790 if (stat_f || all)
4791 {
4792 sprintf (fname1, "/proc/%ld/stat", pid);
4793 if ((procfile = fopen (fname1, "r")) != NULL)
4794 {
4795 int itmp;
4796 char ctmp;
4797 long ltmp;
4798 struct cleanup *cleanup = make_cleanup_fclose (procfile);
4799
4800 if (fscanf (procfile, "%d ", &itmp) > 0)
4801 printf_filtered (_("Process: %d\n"), itmp);
4802 if (fscanf (procfile, "(%[^)]) ", &buffer[0]) > 0)
4803 printf_filtered (_("Exec file: %s\n"), buffer);
4804 if (fscanf (procfile, "%c ", &ctmp) > 0)
4805 printf_filtered (_("State: %c\n"), ctmp);
4806 if (fscanf (procfile, "%d ", &itmp) > 0)
4807 printf_filtered (_("Parent process: %d\n"), itmp);
4808 if (fscanf (procfile, "%d ", &itmp) > 0)
4809 printf_filtered (_("Process group: %d\n"), itmp);
4810 if (fscanf (procfile, "%d ", &itmp) > 0)
4811 printf_filtered (_("Session id: %d\n"), itmp);
4812 if (fscanf (procfile, "%d ", &itmp) > 0)
4813 printf_filtered (_("TTY: %d\n"), itmp);
4814 if (fscanf (procfile, "%d ", &itmp) > 0)
4815 printf_filtered (_("TTY owner process group: %d\n"), itmp);
4816 if (fscanf (procfile, "%lu ", &ltmp) > 0)
4817 printf_filtered (_("Flags: 0x%lx\n"), ltmp);
4818 if (fscanf (procfile, "%lu ", &ltmp) > 0)
4819 printf_filtered (_("Minor faults (no memory page): %lu\n"),
4820 (unsigned long) ltmp);
4821 if (fscanf (procfile, "%lu ", &ltmp) > 0)
4822 printf_filtered (_("Minor faults, children: %lu\n"),
4823 (unsigned long) ltmp);
4824 if (fscanf (procfile, "%lu ", &ltmp) > 0)
4825 printf_filtered (_("Major faults (memory page faults): %lu\n"),
4826 (unsigned long) ltmp);
4827 if (fscanf (procfile, "%lu ", &ltmp) > 0)
4828 printf_filtered (_("Major faults, children: %lu\n"),
4829 (unsigned long) ltmp);
4830 if (fscanf (procfile, "%ld ", &ltmp) > 0)
4831 printf_filtered (_("utime: %ld\n"), ltmp);
4832 if (fscanf (procfile, "%ld ", &ltmp) > 0)
4833 printf_filtered (_("stime: %ld\n"), ltmp);
4834 if (fscanf (procfile, "%ld ", &ltmp) > 0)
4835 printf_filtered (_("utime, children: %ld\n"), ltmp);
4836 if (fscanf (procfile, "%ld ", &ltmp) > 0)
4837 printf_filtered (_("stime, children: %ld\n"), ltmp);
4838 if (fscanf (procfile, "%ld ", &ltmp) > 0)
4839 printf_filtered (_("jiffies remaining in current "
4840 "time slice: %ld\n"), ltmp);
4841 if (fscanf (procfile, "%ld ", &ltmp) > 0)
4842 printf_filtered (_("'nice' value: %ld\n"), ltmp);
4843 if (fscanf (procfile, "%lu ", &ltmp) > 0)
4844 printf_filtered (_("jiffies until next timeout: %lu\n"),
4845 (unsigned long) ltmp);
4846 if (fscanf (procfile, "%lu ", &ltmp) > 0)
4847 printf_filtered (_("jiffies until next SIGALRM: %lu\n"),
4848 (unsigned long) ltmp);
4849 if (fscanf (procfile, "%ld ", &ltmp) > 0)
4850 printf_filtered (_("start time (jiffies since "
4851 "system boot): %ld\n"), ltmp);
4852 if (fscanf (procfile, "%lu ", &ltmp) > 0)
4853 printf_filtered (_("Virtual memory size: %lu\n"),
4854 (unsigned long) ltmp);
4855 if (fscanf (procfile, "%lu ", &ltmp) > 0)
4856 printf_filtered (_("Resident set size: %lu\n"),
4857 (unsigned long) ltmp);
4858 if (fscanf (procfile, "%lu ", &ltmp) > 0)
4859 printf_filtered (_("rlim: %lu\n"), (unsigned long) ltmp);
4860 if (fscanf (procfile, "%lu ", &ltmp) > 0)
4861 printf_filtered (_("Start of text: 0x%lx\n"), ltmp);
4862 if (fscanf (procfile, "%lu ", &ltmp) > 0)
4863 printf_filtered (_("End of text: 0x%lx\n"), ltmp);
4864 if (fscanf (procfile, "%lu ", &ltmp) > 0)
4865 printf_filtered (_("Start of stack: 0x%lx\n"), ltmp);
4866 #if 0 /* Don't know how architecture-dependent the rest is...
4867 Anyway the signal bitmap info is available from "status". */
4868 if (fscanf (procfile, "%lu ", &ltmp) > 0) /* FIXME arch? */
4869 printf_filtered (_("Kernel stack pointer: 0x%lx\n"), ltmp);
4870 if (fscanf (procfile, "%lu ", &ltmp) > 0) /* FIXME arch? */
4871 printf_filtered (_("Kernel instr pointer: 0x%lx\n"), ltmp);
4872 if (fscanf (procfile, "%ld ", &ltmp) > 0)
4873 printf_filtered (_("Pending signals bitmap: 0x%lx\n"), ltmp);
4874 if (fscanf (procfile, "%ld ", &ltmp) > 0)
4875 printf_filtered (_("Blocked signals bitmap: 0x%lx\n"), ltmp);
4876 if (fscanf (procfile, "%ld ", &ltmp) > 0)
4877 printf_filtered (_("Ignored signals bitmap: 0x%lx\n"), ltmp);
4878 if (fscanf (procfile, "%ld ", &ltmp) > 0)
4879 printf_filtered (_("Catched signals bitmap: 0x%lx\n"), ltmp);
4880 if (fscanf (procfile, "%lu ", &ltmp) > 0) /* FIXME arch? */
4881 printf_filtered (_("wchan (system call): 0x%lx\n"), ltmp);
4882 #endif
4883 do_cleanups (cleanup);
4884 }
4885 else
4886 warning (_("unable to open /proc file '%s'"), fname1);
4887 }
4888 }
4889
4890 /* Implement the to_xfer_partial interface for memory reads using the /proc
4891 filesystem. Because we can use a single read() call for /proc, this
4892 can be much more efficient than banging away at PTRACE_PEEKTEXT,
4893 but it doesn't support writes. */
4894
4895 static LONGEST
4896 linux_proc_xfer_partial (struct target_ops *ops, enum target_object object,
4897 const char *annex, gdb_byte *readbuf,
4898 const gdb_byte *writebuf,
4899 ULONGEST offset, LONGEST len)
4900 {
4901 LONGEST ret;
4902 int fd;
4903 char filename[64];
4904
4905 if (object != TARGET_OBJECT_MEMORY || !readbuf)
4906 return 0;
4907
4908 /* Don't bother for one word. */
4909 if (len < 3 * sizeof (long))
4910 return 0;
4911
4912 /* We could keep this file open and cache it - possibly one per
4913 thread. That requires some juggling, but is even faster. */
4914 sprintf (filename, "/proc/%d/mem", PIDGET (inferior_ptid));
4915 fd = open (filename, O_RDONLY | O_LARGEFILE);
4916 if (fd == -1)
4917 return 0;
4918
4919 /* If pread64 is available, use it. It's faster if the kernel
4920 supports it (only one syscall), and it's 64-bit safe even on
4921 32-bit platforms (for instance, SPARC debugging a SPARC64
4922 application). */
4923 #ifdef HAVE_PREAD64
4924 if (pread64 (fd, readbuf, len, offset) != len)
4925 #else
4926 if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len)
4927 #endif
4928 ret = 0;
4929 else
4930 ret = len;
4931
4932 close (fd);
4933 return ret;
4934 }
4935
4936
4937 /* Enumerate spufs IDs for process PID. */
4938 static LONGEST
4939 spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, LONGEST len)
4940 {
4941 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
4942 LONGEST pos = 0;
4943 LONGEST written = 0;
4944 char path[128];
4945 DIR *dir;
4946 struct dirent *entry;
4947
4948 xsnprintf (path, sizeof path, "/proc/%d/fd", pid);
4949 dir = opendir (path);
4950 if (!dir)
4951 return -1;
4952
4953 rewinddir (dir);
4954 while ((entry = readdir (dir)) != NULL)
4955 {
4956 struct stat st;
4957 struct statfs stfs;
4958 int fd;
4959
4960 fd = atoi (entry->d_name);
4961 if (!fd)
4962 continue;
4963
4964 xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd);
4965 if (stat (path, &st) != 0)
4966 continue;
4967 if (!S_ISDIR (st.st_mode))
4968 continue;
4969
4970 if (statfs (path, &stfs) != 0)
4971 continue;
4972 if (stfs.f_type != SPUFS_MAGIC)
4973 continue;
4974
4975 if (pos >= offset && pos + 4 <= offset + len)
4976 {
4977 store_unsigned_integer (buf + pos - offset, 4, byte_order, fd);
4978 written += 4;
4979 }
4980 pos += 4;
4981 }
4982
4983 closedir (dir);
4984 return written;
4985 }
4986
4987 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4988 object type, using the /proc file system. */
4989 static LONGEST
4990 linux_proc_xfer_spu (struct target_ops *ops, enum target_object object,
4991 const char *annex, gdb_byte *readbuf,
4992 const gdb_byte *writebuf,
4993 ULONGEST offset, LONGEST len)
4994 {
4995 char buf[128];
4996 int fd = 0;
4997 int ret = -1;
4998 int pid = PIDGET (inferior_ptid);
4999
5000 if (!annex)
5001 {
5002 if (!readbuf)
5003 return -1;
5004 else
5005 return spu_enumerate_spu_ids (pid, readbuf, offset, len);
5006 }
5007
5008 xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex);
5009 fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
5010 if (fd <= 0)
5011 return -1;
5012
5013 if (offset != 0
5014 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
5015 {
5016 close (fd);
5017 return 0;
5018 }
5019
5020 if (writebuf)
5021 ret = write (fd, writebuf, (size_t) len);
5022 else if (readbuf)
5023 ret = read (fd, readbuf, (size_t) len);
5024
5025 close (fd);
5026 return ret;
5027 }
5028
5029
5030 /* Parse LINE as a signal set and add its set bits to SIGS. */
5031
5032 static void
5033 add_line_to_sigset (const char *line, sigset_t *sigs)
5034 {
5035 int len = strlen (line) - 1;
5036 const char *p;
5037 int signum;
5038
5039 if (line[len] != '\n')
5040 error (_("Could not parse signal set: %s"), line);
5041
5042 p = line;
5043 signum = len * 4;
5044 while (len-- > 0)
5045 {
5046 int digit;
5047
5048 if (*p >= '0' && *p <= '9')
5049 digit = *p - '0';
5050 else if (*p >= 'a' && *p <= 'f')
5051 digit = *p - 'a' + 10;
5052 else
5053 error (_("Could not parse signal set: %s"), line);
5054
5055 signum -= 4;
5056
5057 if (digit & 1)
5058 sigaddset (sigs, signum + 1);
5059 if (digit & 2)
5060 sigaddset (sigs, signum + 2);
5061 if (digit & 4)
5062 sigaddset (sigs, signum + 3);
5063 if (digit & 8)
5064 sigaddset (sigs, signum + 4);
5065
5066 p++;
5067 }
5068 }
5069
5070 /* Find process PID's pending signals from /proc/pid/status and set
5071 SIGS to match. */
5072
5073 void
5074 linux_proc_pending_signals (int pid, sigset_t *pending,
5075 sigset_t *blocked, sigset_t *ignored)
5076 {
5077 FILE *procfile;
5078 char buffer[MAXPATHLEN], fname[MAXPATHLEN];
5079 struct cleanup *cleanup;
5080
5081 sigemptyset (pending);
5082 sigemptyset (blocked);
5083 sigemptyset (ignored);
5084 sprintf (fname, "/proc/%d/status", pid);
5085 procfile = fopen (fname, "r");
5086 if (procfile == NULL)
5087 error (_("Could not open %s"), fname);
5088 cleanup = make_cleanup_fclose (procfile);
5089
5090 while (fgets (buffer, MAXPATHLEN, procfile) != NULL)
5091 {
5092 /* Normal queued signals are on the SigPnd line in the status
5093 file. However, 2.6 kernels also have a "shared" pending
5094 queue for delivering signals to a thread group, so check for
5095 a ShdPnd line also.
5096
5097 Unfortunately some Red Hat kernels include the shared pending
5098 queue but not the ShdPnd status field. */
5099
5100 if (strncmp (buffer, "SigPnd:\t", 8) == 0)
5101 add_line_to_sigset (buffer + 8, pending);
5102 else if (strncmp (buffer, "ShdPnd:\t", 8) == 0)
5103 add_line_to_sigset (buffer + 8, pending);
5104 else if (strncmp (buffer, "SigBlk:\t", 8) == 0)
5105 add_line_to_sigset (buffer + 8, blocked);
5106 else if (strncmp (buffer, "SigIgn:\t", 8) == 0)
5107 add_line_to_sigset (buffer + 8, ignored);
5108 }
5109
5110 do_cleanups (cleanup);
5111 }
5112
5113 static LONGEST
5114 linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object,
5115 const char *annex, gdb_byte *readbuf,
5116 const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
5117 {
5118 gdb_assert (object == TARGET_OBJECT_OSDATA);
5119
5120 return linux_common_xfer_osdata (annex, readbuf, offset, len);
5121 }
5122
5123 static LONGEST
5124 linux_xfer_partial (struct target_ops *ops, enum target_object object,
5125 const char *annex, gdb_byte *readbuf,
5126 const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
5127 {
5128 LONGEST xfer;
5129
5130 if (object == TARGET_OBJECT_AUXV)
5131 return memory_xfer_auxv (ops, object, annex, readbuf, writebuf,
5132 offset, len);
5133
5134 if (object == TARGET_OBJECT_OSDATA)
5135 return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf,
5136 offset, len);
5137
5138 if (object == TARGET_OBJECT_SPU)
5139 return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf,
5140 offset, len);
5141
5142 /* GDB calculates all the addresses in possibly larget width of the address.
5143 Address width needs to be masked before its final use - either by
5144 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
5145
5146 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
5147
5148 if (object == TARGET_OBJECT_MEMORY)
5149 {
5150 int addr_bit = gdbarch_addr_bit (target_gdbarch);
5151
5152 if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT))
5153 offset &= ((ULONGEST) 1 << addr_bit) - 1;
5154 }
5155
5156 xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf,
5157 offset, len);
5158 if (xfer != 0)
5159 return xfer;
5160
5161 return super_xfer_partial (ops, object, annex, readbuf, writebuf,
5162 offset, len);
5163 }
5164
5165 /* Create a prototype generic GNU/Linux target. The client can override
5166 it with local methods. */
5167
5168 static void
5169 linux_target_install_ops (struct target_ops *t)
5170 {
5171 t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint;
5172 t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint;
5173 t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint;
5174 t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint;
5175 t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint;
5176 t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint;
5177 t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint;
5178 t->to_pid_to_exec_file = linux_child_pid_to_exec_file;
5179 t->to_post_startup_inferior = linux_child_post_startup_inferior;
5180 t->to_post_attach = linux_child_post_attach;
5181 t->to_follow_fork = linux_child_follow_fork;
5182 t->to_find_memory_regions = linux_nat_find_memory_regions;
5183 t->to_make_corefile_notes = linux_nat_make_corefile_notes;
5184
5185 super_xfer_partial = t->to_xfer_partial;
5186 t->to_xfer_partial = linux_xfer_partial;
5187 }
5188
5189 struct target_ops *
5190 linux_target (void)
5191 {
5192 struct target_ops *t;
5193
5194 t = inf_ptrace_target ();
5195 linux_target_install_ops (t);
5196
5197 return t;
5198 }
5199
5200 struct target_ops *
5201 linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int))
5202 {
5203 struct target_ops *t;
5204
5205 t = inf_ptrace_trad_target (register_u_offset);
5206 linux_target_install_ops (t);
5207
5208 return t;
5209 }
5210
5211 /* target_is_async_p implementation. */
5212
5213 static int
5214 linux_nat_is_async_p (void)
5215 {
5216 /* NOTE: palves 2008-03-21: We're only async when the user requests
5217 it explicitly with the "set target-async" command.
5218 Someday, linux will always be async. */
5219 return target_async_permitted;
5220 }
5221
5222 /* target_can_async_p implementation. */
5223
5224 static int
5225 linux_nat_can_async_p (void)
5226 {
5227 /* NOTE: palves 2008-03-21: We're only async when the user requests
5228 it explicitly with the "set target-async" command.
5229 Someday, linux will always be async. */
5230 return target_async_permitted;
5231 }
5232
5233 static int
5234 linux_nat_supports_non_stop (void)
5235 {
5236 return 1;
5237 }
5238
5239 /* True if we want to support multi-process. To be removed when GDB
5240 supports multi-exec. */
5241
5242 int linux_multi_process = 1;
5243
5244 static int
5245 linux_nat_supports_multi_process (void)
5246 {
5247 return linux_multi_process;
5248 }
5249
5250 static int async_terminal_is_ours = 1;
5251
5252 /* target_terminal_inferior implementation. */
5253
5254 static void
5255 linux_nat_terminal_inferior (void)
5256 {
5257 if (!target_is_async_p ())
5258 {
5259 /* Async mode is disabled. */
5260 terminal_inferior ();
5261 return;
5262 }
5263
5264 terminal_inferior ();
5265
5266 /* Calls to target_terminal_*() are meant to be idempotent. */
5267 if (!async_terminal_is_ours)
5268 return;
5269
5270 delete_file_handler (input_fd);
5271 async_terminal_is_ours = 0;
5272 set_sigint_trap ();
5273 }
5274
5275 /* target_terminal_ours implementation. */
5276
5277 static void
5278 linux_nat_terminal_ours (void)
5279 {
5280 if (!target_is_async_p ())
5281 {
5282 /* Async mode is disabled. */
5283 terminal_ours ();
5284 return;
5285 }
5286
5287 /* GDB should never give the terminal to the inferior if the
5288 inferior is running in the background (run&, continue&, etc.),
5289 but claiming it sure should. */
5290 terminal_ours ();
5291
5292 if (async_terminal_is_ours)
5293 return;
5294
5295 clear_sigint_trap ();
5296 add_file_handler (input_fd, stdin_event_handler, 0);
5297 async_terminal_is_ours = 1;
5298 }
5299
5300 static void (*async_client_callback) (enum inferior_event_type event_type,
5301 void *context);
5302 static void *async_client_context;
5303
5304 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
5305 so we notice when any child changes state, and notify the
5306 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
5307 above to wait for the arrival of a SIGCHLD. */
5308
5309 static void
5310 sigchld_handler (int signo)
5311 {
5312 int old_errno = errno;
5313
5314 if (debug_linux_nat)
5315 ui_file_write_async_safe (gdb_stdlog,
5316 "sigchld\n", sizeof ("sigchld\n") - 1);
5317
5318 if (signo == SIGCHLD
5319 && linux_nat_event_pipe[0] != -1)
5320 async_file_mark (); /* Let the event loop know that there are
5321 events to handle. */
5322
5323 errno = old_errno;
5324 }
5325
5326 /* Callback registered with the target events file descriptor. */
5327
5328 static void
5329 handle_target_event (int error, gdb_client_data client_data)
5330 {
5331 (*async_client_callback) (INF_REG_EVENT, async_client_context);
5332 }
5333
5334 /* Create/destroy the target events pipe. Returns previous state. */
5335
5336 static int
5337 linux_async_pipe (int enable)
5338 {
5339 int previous = (linux_nat_event_pipe[0] != -1);
5340
5341 if (previous != enable)
5342 {
5343 sigset_t prev_mask;
5344
5345 block_child_signals (&prev_mask);
5346
5347 if (enable)
5348 {
5349 if (pipe (linux_nat_event_pipe) == -1)
5350 internal_error (__FILE__, __LINE__,
5351 "creating event pipe failed.");
5352
5353 fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK);
5354 fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK);
5355 }
5356 else
5357 {
5358 close (linux_nat_event_pipe[0]);
5359 close (linux_nat_event_pipe[1]);
5360 linux_nat_event_pipe[0] = -1;
5361 linux_nat_event_pipe[1] = -1;
5362 }
5363
5364 restore_child_signals_mask (&prev_mask);
5365 }
5366
5367 return previous;
5368 }
5369
5370 /* target_async implementation. */
5371
5372 static void
5373 linux_nat_async (void (*callback) (enum inferior_event_type event_type,
5374 void *context), void *context)
5375 {
5376 if (callback != NULL)
5377 {
5378 async_client_callback = callback;
5379 async_client_context = context;
5380 if (!linux_async_pipe (1))
5381 {
5382 add_file_handler (linux_nat_event_pipe[0],
5383 handle_target_event, NULL);
5384 /* There may be pending events to handle. Tell the event loop
5385 to poll them. */
5386 async_file_mark ();
5387 }
5388 }
5389 else
5390 {
5391 async_client_callback = callback;
5392 async_client_context = context;
5393 delete_file_handler (linux_nat_event_pipe[0]);
5394 linux_async_pipe (0);
5395 }
5396 return;
5397 }
5398
5399 /* Stop an LWP, and push a TARGET_SIGNAL_0 stop status if no other
5400 event came out. */
5401
5402 static int
5403 linux_nat_stop_lwp (struct lwp_info *lwp, void *data)
5404 {
5405 if (!lwp->stopped)
5406 {
5407 ptid_t ptid = lwp->ptid;
5408
5409 if (debug_linux_nat)
5410 fprintf_unfiltered (gdb_stdlog,
5411 "LNSL: running -> suspending %s\n",
5412 target_pid_to_str (lwp->ptid));
5413
5414
5415 stop_callback (lwp, NULL);
5416 stop_wait_callback (lwp, NULL);
5417
5418 /* If the lwp exits while we try to stop it, there's nothing
5419 else to do. */
5420 lwp = find_lwp_pid (ptid);
5421 if (lwp == NULL)
5422 return 0;
5423
5424 /* If we didn't collect any signal other than SIGSTOP while
5425 stopping the LWP, push a SIGNAL_0 event. In either case, the
5426 event-loop will end up calling target_wait which will collect
5427 these. */
5428 if (lwp->status == 0)
5429 lwp->status = W_STOPCODE (0);
5430 async_file_mark ();
5431 }
5432 else
5433 {
5434 /* Already known to be stopped; do nothing. */
5435
5436 if (debug_linux_nat)
5437 {
5438 if (find_thread_ptid (lwp->ptid)->stop_requested)
5439 fprintf_unfiltered (gdb_stdlog,
5440 "LNSL: already stopped/stop_requested %s\n",
5441 target_pid_to_str (lwp->ptid));
5442 else
5443 fprintf_unfiltered (gdb_stdlog,
5444 "LNSL: already stopped/no "
5445 "stop_requested yet %s\n",
5446 target_pid_to_str (lwp->ptid));
5447 }
5448 }
5449 return 0;
5450 }
5451
5452 static void
5453 linux_nat_stop (ptid_t ptid)
5454 {
5455 if (non_stop)
5456 iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL);
5457 else
5458 linux_ops->to_stop (ptid);
5459 }
5460
5461 static void
5462 linux_nat_close (int quitting)
5463 {
5464 /* Unregister from the event loop. */
5465 if (target_is_async_p ())
5466 target_async (NULL, 0);
5467
5468 if (linux_ops->to_close)
5469 linux_ops->to_close (quitting);
5470 }
5471
5472 /* When requests are passed down from the linux-nat layer to the
5473 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
5474 used. The address space pointer is stored in the inferior object,
5475 but the common code that is passed such ptid can't tell whether
5476 lwpid is a "main" process id or not (it assumes so). We reverse
5477 look up the "main" process id from the lwp here. */
5478
5479 struct address_space *
5480 linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid)
5481 {
5482 struct lwp_info *lwp;
5483 struct inferior *inf;
5484 int pid;
5485
5486 pid = GET_LWP (ptid);
5487 if (GET_LWP (ptid) == 0)
5488 {
5489 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
5490 tgid. */
5491 lwp = find_lwp_pid (ptid);
5492 pid = GET_PID (lwp->ptid);
5493 }
5494 else
5495 {
5496 /* A (pid,lwpid,0) ptid. */
5497 pid = GET_PID (ptid);
5498 }
5499
5500 inf = find_inferior_pid (pid);
5501 gdb_assert (inf != NULL);
5502 return inf->aspace;
5503 }
5504
5505 int
5506 linux_nat_core_of_thread_1 (ptid_t ptid)
5507 {
5508 struct cleanup *back_to;
5509 char *filename;
5510 FILE *f;
5511 char *content = NULL;
5512 char *p;
5513 char *ts = 0;
5514 int content_read = 0;
5515 int i;
5516 int core;
5517
5518 filename = xstrprintf ("/proc/%d/task/%ld/stat",
5519 GET_PID (ptid), GET_LWP (ptid));
5520 back_to = make_cleanup (xfree, filename);
5521
5522 f = fopen (filename, "r");
5523 if (!f)
5524 {
5525 do_cleanups (back_to);
5526 return -1;
5527 }
5528
5529 make_cleanup_fclose (f);
5530
5531 for (;;)
5532 {
5533 int n;
5534
5535 content = xrealloc (content, content_read + 1024);
5536 n = fread (content + content_read, 1, 1024, f);
5537 content_read += n;
5538 if (n < 1024)
5539 {
5540 content[content_read] = '\0';
5541 break;
5542 }
5543 }
5544
5545 make_cleanup (xfree, content);
5546
5547 p = strchr (content, '(');
5548
5549 /* Skip ")". */
5550 if (p != NULL)
5551 p = strchr (p, ')');
5552 if (p != NULL)
5553 p++;
5554
5555 /* If the first field after program name has index 0, then core number is
5556 the field with index 36. There's no constant for that anywhere. */
5557 if (p != NULL)
5558 p = strtok_r (p, " ", &ts);
5559 for (i = 0; p != NULL && i != 36; ++i)
5560 p = strtok_r (NULL, " ", &ts);
5561
5562 if (p == NULL || sscanf (p, "%d", &core) == 0)
5563 core = -1;
5564
5565 do_cleanups (back_to);
5566
5567 return core;
5568 }
5569
5570 /* Return the cached value of the processor core for thread PTID. */
5571
5572 int
5573 linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid)
5574 {
5575 struct lwp_info *info = find_lwp_pid (ptid);
5576
5577 if (info)
5578 return info->core;
5579 return -1;
5580 }
5581
5582 void
5583 linux_nat_add_target (struct target_ops *t)
5584 {
5585 /* Save the provided single-threaded target. We save this in a separate
5586 variable because another target we've inherited from (e.g. inf-ptrace)
5587 may have saved a pointer to T; we want to use it for the final
5588 process stratum target. */
5589 linux_ops_saved = *t;
5590 linux_ops = &linux_ops_saved;
5591
5592 /* Override some methods for multithreading. */
5593 t->to_create_inferior = linux_nat_create_inferior;
5594 t->to_attach = linux_nat_attach;
5595 t->to_detach = linux_nat_detach;
5596 t->to_resume = linux_nat_resume;
5597 t->to_wait = linux_nat_wait;
5598 t->to_pass_signals = linux_nat_pass_signals;
5599 t->to_xfer_partial = linux_nat_xfer_partial;
5600 t->to_kill = linux_nat_kill;
5601 t->to_mourn_inferior = linux_nat_mourn_inferior;
5602 t->to_thread_alive = linux_nat_thread_alive;
5603 t->to_pid_to_str = linux_nat_pid_to_str;
5604 t->to_thread_name = linux_nat_thread_name;
5605 t->to_has_thread_control = tc_schedlock;
5606 t->to_thread_address_space = linux_nat_thread_address_space;
5607 t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint;
5608 t->to_stopped_data_address = linux_nat_stopped_data_address;
5609
5610 t->to_can_async_p = linux_nat_can_async_p;
5611 t->to_is_async_p = linux_nat_is_async_p;
5612 t->to_supports_non_stop = linux_nat_supports_non_stop;
5613 t->to_async = linux_nat_async;
5614 t->to_terminal_inferior = linux_nat_terminal_inferior;
5615 t->to_terminal_ours = linux_nat_terminal_ours;
5616 t->to_close = linux_nat_close;
5617
5618 /* Methods for non-stop support. */
5619 t->to_stop = linux_nat_stop;
5620
5621 t->to_supports_multi_process = linux_nat_supports_multi_process;
5622
5623 t->to_core_of_thread = linux_nat_core_of_thread;
5624
5625 /* We don't change the stratum; this target will sit at
5626 process_stratum and thread_db will set at thread_stratum. This
5627 is a little strange, since this is a multi-threaded-capable
5628 target, but we want to be on the stack below thread_db, and we
5629 also want to be used for single-threaded processes. */
5630
5631 add_target (t);
5632 }
5633
5634 /* Register a method to call whenever a new thread is attached. */
5635 void
5636 linux_nat_set_new_thread (struct target_ops *t, void (*new_thread) (ptid_t))
5637 {
5638 /* Save the pointer. We only support a single registered instance
5639 of the GNU/Linux native target, so we do not need to map this to
5640 T. */
5641 linux_nat_new_thread = new_thread;
5642 }
5643
5644 /* Register a method that converts a siginfo object between the layout
5645 that ptrace returns, and the layout in the architecture of the
5646 inferior. */
5647 void
5648 linux_nat_set_siginfo_fixup (struct target_ops *t,
5649 int (*siginfo_fixup) (struct siginfo *,
5650 gdb_byte *,
5651 int))
5652 {
5653 /* Save the pointer. */
5654 linux_nat_siginfo_fixup = siginfo_fixup;
5655 }
5656
5657 /* Return the saved siginfo associated with PTID. */
5658 struct siginfo *
5659 linux_nat_get_siginfo (ptid_t ptid)
5660 {
5661 struct lwp_info *lp = find_lwp_pid (ptid);
5662
5663 gdb_assert (lp != NULL);
5664
5665 return &lp->siginfo;
5666 }
5667
5668 /* Provide a prototype to silence -Wmissing-prototypes. */
5669 extern initialize_file_ftype _initialize_linux_nat;
5670
5671 void
5672 _initialize_linux_nat (void)
5673 {
5674 add_info ("proc", linux_nat_info_proc_cmd, _("\
5675 Show /proc process information about any running process.\n\
5676 Specify any process id, or use the program being debugged by default.\n\
5677 Specify any of the following keywords for detailed info:\n\
5678 mappings -- list of mapped memory regions.\n\
5679 stat -- list a bunch of random process info.\n\
5680 status -- list a different bunch of random process info.\n\
5681 all -- list all available /proc info."));
5682
5683 add_setshow_zinteger_cmd ("lin-lwp", class_maintenance,
5684 &debug_linux_nat, _("\
5685 Set debugging of GNU/Linux lwp module."), _("\
5686 Show debugging of GNU/Linux lwp module."), _("\
5687 Enables printf debugging output."),
5688 NULL,
5689 show_debug_linux_nat,
5690 &setdebuglist, &showdebuglist);
5691
5692 /* Save this mask as the default. */
5693 sigprocmask (SIG_SETMASK, NULL, &normal_mask);
5694
5695 /* Install a SIGCHLD handler. */
5696 sigchld_action.sa_handler = sigchld_handler;
5697 sigemptyset (&sigchld_action.sa_mask);
5698 sigchld_action.sa_flags = SA_RESTART;
5699
5700 /* Make it the default. */
5701 sigaction (SIGCHLD, &sigchld_action, NULL);
5702
5703 /* Make sure we don't block SIGCHLD during a sigsuspend. */
5704 sigprocmask (SIG_SETMASK, NULL, &suspend_mask);
5705 sigdelset (&suspend_mask, SIGCHLD);
5706
5707 sigemptyset (&blocked_mask);
5708
5709 add_setshow_boolean_cmd ("disable-randomization", class_support,
5710 &disable_randomization, _("\
5711 Set disabling of debuggee's virtual address space randomization."), _("\
5712 Show disabling of debuggee's virtual address space randomization."), _("\
5713 When this mode is on (which is the default), randomization of the virtual\n\
5714 address space is disabled. Standalone programs run with the randomization\n\
5715 enabled by default on some platforms."),
5716 &set_disable_randomization,
5717 &show_disable_randomization,
5718 &setlist, &showlist);
5719 }
5720 \f
5721
5722 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
5723 the GNU/Linux Threads library and therefore doesn't really belong
5724 here. */
5725
5726 /* Read variable NAME in the target and return its value if found.
5727 Otherwise return zero. It is assumed that the type of the variable
5728 is `int'. */
5729
5730 static int
5731 get_signo (const char *name)
5732 {
5733 struct minimal_symbol *ms;
5734 int signo;
5735
5736 ms = lookup_minimal_symbol (name, NULL, NULL);
5737 if (ms == NULL)
5738 return 0;
5739
5740 if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo,
5741 sizeof (signo)) != 0)
5742 return 0;
5743
5744 return signo;
5745 }
5746
5747 /* Return the set of signals used by the threads library in *SET. */
5748
5749 void
5750 lin_thread_get_thread_signals (sigset_t *set)
5751 {
5752 struct sigaction action;
5753 int restart, cancel;
5754
5755 sigemptyset (&blocked_mask);
5756 sigemptyset (set);
5757
5758 restart = get_signo ("__pthread_sig_restart");
5759 cancel = get_signo ("__pthread_sig_cancel");
5760
5761 /* LinuxThreads normally uses the first two RT signals, but in some legacy
5762 cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
5763 not provide any way for the debugger to query the signal numbers -
5764 fortunately they don't change! */
5765
5766 if (restart == 0)
5767 restart = __SIGRTMIN;
5768
5769 if (cancel == 0)
5770 cancel = __SIGRTMIN + 1;
5771
5772 sigaddset (set, restart);
5773 sigaddset (set, cancel);
5774
5775 /* The GNU/Linux Threads library makes terminating threads send a
5776 special "cancel" signal instead of SIGCHLD. Make sure we catch
5777 those (to prevent them from terminating GDB itself, which is
5778 likely to be their default action) and treat them the same way as
5779 SIGCHLD. */
5780
5781 action.sa_handler = sigchld_handler;
5782 sigemptyset (&action.sa_mask);
5783 action.sa_flags = SA_RESTART;
5784 sigaction (cancel, &action, NULL);
5785
5786 /* We block the "cancel" signal throughout this code ... */
5787 sigaddset (&blocked_mask, cancel);
5788 sigprocmask (SIG_BLOCK, &blocked_mask, NULL);
5789
5790 /* ... except during a sigsuspend. */
5791 sigdelset (&suspend_mask, cancel);
5792 }
This page took 0.185749 seconds and 4 git commands to generate.