1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
4 2011 Free Software Foundation, Inc.
6 This file is part of GDB.
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.
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.
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/>. */
24 #include "gdb_string.h"
26 #include "gdb_assert.h"
27 #ifdef HAVE_TKILL_SYSCALL
29 #include <sys/syscall.h>
31 #include <sys/ptrace.h>
32 #include "linux-nat.h"
33 #include "linux-ptrace.h"
34 #include "linux-procfs.h"
35 #include "linux-fork.h"
36 #include "gdbthread.h"
40 #include "inf-ptrace.h"
42 #include <sys/param.h> /* for MAXPATHLEN */
43 #include <sys/procfs.h> /* for elf_gregset etc. */
44 #include "elf-bfd.h" /* for elfcore_write_* */
45 #include "gregset.h" /* for gregset */
46 #include "gdbcore.h" /* for get_exec_file */
47 #include <ctype.h> /* for isdigit */
48 #include "gdbthread.h" /* for struct thread_info etc. */
49 #include "gdb_stat.h" /* for struct stat */
50 #include <fcntl.h> /* for O_RDONLY */
52 #include "event-loop.h"
53 #include "event-top.h"
55 #include <sys/types.h>
56 #include "gdb_dirent.h"
57 #include "xml-support.h"
61 #include "linux-osdata.h"
64 #define SPUFS_MAGIC 0x23c9b64e
67 #ifdef HAVE_PERSONALITY
68 # include <sys/personality.h>
69 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
70 # define ADDR_NO_RANDOMIZE 0x0040000
72 #endif /* HAVE_PERSONALITY */
74 /* This comment documents high-level logic of this file.
76 Waiting for events in sync mode
77 ===============================
79 When waiting for an event in a specific thread, we just use waitpid, passing
80 the specific pid, and not passing WNOHANG.
82 When waiting for an event in all threads, waitpid is not quite good. Prior to
83 version 2.4, Linux can either wait for event in main thread, or in secondary
84 threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might
85 miss an event. The solution is to use non-blocking waitpid, together with
86 sigsuspend. First, we use non-blocking waitpid to get an event in the main
87 process, if any. Second, we use non-blocking waitpid with the __WCLONED
88 flag to check for events in cloned processes. If nothing is found, we use
89 sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something
90 happened to a child process -- and SIGCHLD will be delivered both for events
91 in main debugged process and in cloned processes. As soon as we know there's
92 an event, we get back to calling nonblocking waitpid with and without
95 Note that SIGCHLD should be blocked between waitpid and sigsuspend calls,
96 so that we don't miss a signal. If SIGCHLD arrives in between, when it's
97 blocked, the signal becomes pending and sigsuspend immediately
98 notices it and returns.
100 Waiting for events in async mode
101 ================================
103 In async mode, GDB should always be ready to handle both user input
104 and target events, so neither blocking waitpid nor sigsuspend are
105 viable options. Instead, we should asynchronously notify the GDB main
106 event loop whenever there's an unprocessed event from the target. We
107 detect asynchronous target events by handling SIGCHLD signals. To
108 notify the event loop about target events, the self-pipe trick is used
109 --- a pipe is registered as waitable event source in the event loop,
110 the event loop select/poll's on the read end of this pipe (as well on
111 other event sources, e.g., stdin), and the SIGCHLD handler writes a
112 byte to this pipe. This is more portable than relying on
113 pselect/ppoll, since on kernels that lack those syscalls, libc
114 emulates them with select/poll+sigprocmask, and that is racy
115 (a.k.a. plain broken).
117 Obviously, if we fail to notify the event loop if there's a target
118 event, it's bad. OTOH, if we notify the event loop when there's no
119 event from the target, linux_nat_wait will detect that there's no real
120 event to report, and return event of type TARGET_WAITKIND_IGNORE.
121 This is mostly harmless, but it will waste time and is better avoided.
123 The main design point is that every time GDB is outside linux-nat.c,
124 we have a SIGCHLD handler installed that is called when something
125 happens to the target and notifies the GDB event loop. Whenever GDB
126 core decides to handle the event, and calls into linux-nat.c, we
127 process things as in sync mode, except that the we never block in
130 While processing an event, we may end up momentarily blocked in
131 waitpid calls. Those waitpid calls, while blocking, are guarantied to
132 return quickly. E.g., in all-stop mode, before reporting to the core
133 that an LWP hit a breakpoint, all LWPs are stopped by sending them
134 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
135 Note that this is different from blocking indefinitely waiting for the
136 next event --- here, we're already handling an event.
141 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
142 signal is not entirely significant; we just need for a signal to be delivered,
143 so that we can intercept it. SIGSTOP's advantage is that it can not be
144 blocked. A disadvantage is that it is not a real-time signal, so it can only
145 be queued once; we do not keep track of other sources of SIGSTOP.
147 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
148 use them, because they have special behavior when the signal is generated -
149 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
150 kills the entire thread group.
152 A delivered SIGSTOP would stop the entire thread group, not just the thread we
153 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
154 cancel it (by PTRACE_CONT without passing SIGSTOP).
156 We could use a real-time signal instead. This would solve those problems; we
157 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
158 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
159 generates it, and there are races with trying to find a signal that is not
163 #define O_LARGEFILE 0
166 /* Unlike other extended result codes, WSTOPSIG (status) on
167 PTRACE_O_TRACESYSGOOD syscall events doesn't return SIGTRAP, but
168 instead SIGTRAP with bit 7 set. */
169 #define SYSCALL_SIGTRAP (SIGTRAP | 0x80)
171 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
172 the use of the multi-threaded target. */
173 static struct target_ops
*linux_ops
;
174 static struct target_ops linux_ops_saved
;
176 /* The method to call, if any, when a new thread is attached. */
177 static void (*linux_nat_new_thread
) (ptid_t
);
179 /* The method to call, if any, when the siginfo object needs to be
180 converted between the layout returned by ptrace, and the layout in
181 the architecture of the inferior. */
182 static int (*linux_nat_siginfo_fixup
) (struct siginfo
*,
186 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
187 Called by our to_xfer_partial. */
188 static LONGEST (*super_xfer_partial
) (struct target_ops
*,
190 const char *, gdb_byte
*,
194 static int debug_linux_nat
;
196 show_debug_linux_nat (struct ui_file
*file
, int from_tty
,
197 struct cmd_list_element
*c
, const char *value
)
199 fprintf_filtered (file
, _("Debugging of GNU/Linux lwp module is %s.\n"),
203 struct simple_pid_list
207 struct simple_pid_list
*next
;
209 struct simple_pid_list
*stopped_pids
;
211 /* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACEFORK
212 can not be used, 1 if it can. */
214 static int linux_supports_tracefork_flag
= -1;
216 /* This variable is a tri-state flag: -1 for unknown, 0 if
217 PTRACE_O_TRACESYSGOOD can not be used, 1 if it can. */
219 static int linux_supports_tracesysgood_flag
= -1;
221 /* If we have PTRACE_O_TRACEFORK, this flag indicates whether we also have
222 PTRACE_O_TRACEVFORKDONE. */
224 static int linux_supports_tracevforkdone_flag
= -1;
226 /* Stores the current used ptrace() options. */
227 static int current_ptrace_options
= 0;
229 /* Async mode support. */
231 /* The read/write ends of the pipe registered as waitable file in the
233 static int linux_nat_event_pipe
[2] = { -1, -1 };
235 /* Flush the event pipe. */
238 async_file_flush (void)
245 ret
= read (linux_nat_event_pipe
[0], &buf
, 1);
247 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
250 /* Put something (anything, doesn't matter what, or how much) in event
251 pipe, so that the select/poll in the event-loop realizes we have
252 something to process. */
255 async_file_mark (void)
259 /* It doesn't really matter what the pipe contains, as long we end
260 up with something in it. Might as well flush the previous
266 ret
= write (linux_nat_event_pipe
[1], "+", 1);
268 while (ret
== -1 && errno
== EINTR
);
270 /* Ignore EAGAIN. If the pipe is full, the event loop will already
271 be awakened anyway. */
274 static void linux_nat_async (void (*callback
)
275 (enum inferior_event_type event_type
,
278 static int kill_lwp (int lwpid
, int signo
);
280 static int stop_callback (struct lwp_info
*lp
, void *data
);
282 static void block_child_signals (sigset_t
*prev_mask
);
283 static void restore_child_signals_mask (sigset_t
*prev_mask
);
286 static struct lwp_info
*add_lwp (ptid_t ptid
);
287 static void purge_lwp_list (int pid
);
288 static struct lwp_info
*find_lwp_pid (ptid_t ptid
);
291 /* Trivial list manipulation functions to keep track of a list of
292 new stopped processes. */
294 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
296 struct simple_pid_list
*new_pid
= xmalloc (sizeof (struct simple_pid_list
));
299 new_pid
->status
= status
;
300 new_pid
->next
= *listp
;
305 in_pid_list_p (struct simple_pid_list
*list
, int pid
)
307 struct simple_pid_list
*p
;
309 for (p
= list
; p
!= NULL
; p
= p
->next
)
316 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *statusp
)
318 struct simple_pid_list
**p
;
320 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
321 if ((*p
)->pid
== pid
)
323 struct simple_pid_list
*next
= (*p
)->next
;
325 *statusp
= (*p
)->status
;
334 /* A helper function for linux_test_for_tracefork, called after fork (). */
337 linux_tracefork_child (void)
339 ptrace (PTRACE_TRACEME
, 0, 0, 0);
340 kill (getpid (), SIGSTOP
);
345 /* Wrapper function for waitpid which handles EINTR. */
348 my_waitpid (int pid
, int *statusp
, int flags
)
354 ret
= waitpid (pid
, statusp
, flags
);
356 while (ret
== -1 && errno
== EINTR
);
361 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events.
363 First, we try to enable fork tracing on ORIGINAL_PID. If this fails,
364 we know that the feature is not available. This may change the tracing
365 options for ORIGINAL_PID, but we'll be setting them shortly anyway.
367 However, if it succeeds, we don't know for sure that the feature is
368 available; old versions of PTRACE_SETOPTIONS ignored unknown options. We
369 create a child process, attach to it, use PTRACE_SETOPTIONS to enable
370 fork tracing, and let it fork. If the process exits, we assume that we
371 can't use TRACEFORK; if we get the fork notification, and we can extract
372 the new child's PID, then we assume that we can. */
375 linux_test_for_tracefork (int original_pid
)
377 int child_pid
, ret
, status
;
381 /* We don't want those ptrace calls to be interrupted. */
382 block_child_signals (&prev_mask
);
384 linux_supports_tracefork_flag
= 0;
385 linux_supports_tracevforkdone_flag
= 0;
387 ret
= ptrace (PTRACE_SETOPTIONS
, original_pid
, 0, PTRACE_O_TRACEFORK
);
390 restore_child_signals_mask (&prev_mask
);
396 perror_with_name (("fork"));
399 linux_tracefork_child ();
401 ret
= my_waitpid (child_pid
, &status
, 0);
403 perror_with_name (("waitpid"));
404 else if (ret
!= child_pid
)
405 error (_("linux_test_for_tracefork: waitpid: unexpected result %d."), ret
);
406 if (! WIFSTOPPED (status
))
407 error (_("linux_test_for_tracefork: waitpid: unexpected status %d."),
410 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0, PTRACE_O_TRACEFORK
);
413 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
416 warning (_("linux_test_for_tracefork: failed to kill child"));
417 restore_child_signals_mask (&prev_mask
);
421 ret
= my_waitpid (child_pid
, &status
, 0);
422 if (ret
!= child_pid
)
423 warning (_("linux_test_for_tracefork: failed "
424 "to wait for killed child"));
425 else if (!WIFSIGNALED (status
))
426 warning (_("linux_test_for_tracefork: unexpected "
427 "wait status 0x%x from killed child"), status
);
429 restore_child_signals_mask (&prev_mask
);
433 /* Check whether PTRACE_O_TRACEVFORKDONE is available. */
434 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0,
435 PTRACE_O_TRACEFORK
| PTRACE_O_TRACEVFORKDONE
);
436 linux_supports_tracevforkdone_flag
= (ret
== 0);
438 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
440 warning (_("linux_test_for_tracefork: failed to resume child"));
442 ret
= my_waitpid (child_pid
, &status
, 0);
444 if (ret
== child_pid
&& WIFSTOPPED (status
)
445 && status
>> 16 == PTRACE_EVENT_FORK
)
448 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
449 if (ret
== 0 && second_pid
!= 0)
453 linux_supports_tracefork_flag
= 1;
454 my_waitpid (second_pid
, &second_status
, 0);
455 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
457 warning (_("linux_test_for_tracefork: "
458 "failed to kill second child"));
459 my_waitpid (second_pid
, &status
, 0);
463 warning (_("linux_test_for_tracefork: unexpected result from waitpid "
464 "(%d, status 0x%x)"), ret
, status
);
466 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
468 warning (_("linux_test_for_tracefork: failed to kill child"));
469 my_waitpid (child_pid
, &status
, 0);
471 restore_child_signals_mask (&prev_mask
);
474 /* Determine if PTRACE_O_TRACESYSGOOD can be used to follow syscalls.
476 We try to enable syscall tracing on ORIGINAL_PID. If this fails,
477 we know that the feature is not available. This may change the tracing
478 options for ORIGINAL_PID, but we'll be setting them shortly anyway. */
481 linux_test_for_tracesysgood (int original_pid
)
486 /* We don't want those ptrace calls to be interrupted. */
487 block_child_signals (&prev_mask
);
489 linux_supports_tracesysgood_flag
= 0;
491 ret
= ptrace (PTRACE_SETOPTIONS
, original_pid
, 0, PTRACE_O_TRACESYSGOOD
);
495 linux_supports_tracesysgood_flag
= 1;
497 restore_child_signals_mask (&prev_mask
);
500 /* Determine wether we support PTRACE_O_TRACESYSGOOD option available.
501 This function also sets linux_supports_tracesysgood_flag. */
504 linux_supports_tracesysgood (int pid
)
506 if (linux_supports_tracesysgood_flag
== -1)
507 linux_test_for_tracesysgood (pid
);
508 return linux_supports_tracesysgood_flag
;
511 /* Return non-zero iff we have tracefork functionality available.
512 This function also sets linux_supports_tracefork_flag. */
515 linux_supports_tracefork (int pid
)
517 if (linux_supports_tracefork_flag
== -1)
518 linux_test_for_tracefork (pid
);
519 return linux_supports_tracefork_flag
;
523 linux_supports_tracevforkdone (int pid
)
525 if (linux_supports_tracefork_flag
== -1)
526 linux_test_for_tracefork (pid
);
527 return linux_supports_tracevforkdone_flag
;
531 linux_enable_tracesysgood (ptid_t ptid
)
533 int pid
= ptid_get_lwp (ptid
);
536 pid
= ptid_get_pid (ptid
);
538 if (linux_supports_tracesysgood (pid
) == 0)
541 current_ptrace_options
|= PTRACE_O_TRACESYSGOOD
;
543 ptrace (PTRACE_SETOPTIONS
, pid
, 0, current_ptrace_options
);
548 linux_enable_event_reporting (ptid_t ptid
)
550 int pid
= ptid_get_lwp (ptid
);
553 pid
= ptid_get_pid (ptid
);
555 if (! linux_supports_tracefork (pid
))
558 current_ptrace_options
|= PTRACE_O_TRACEFORK
| PTRACE_O_TRACEVFORK
559 | PTRACE_O_TRACEEXEC
| PTRACE_O_TRACECLONE
;
561 if (linux_supports_tracevforkdone (pid
))
562 current_ptrace_options
|= PTRACE_O_TRACEVFORKDONE
;
564 /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support
565 read-only process state. */
567 ptrace (PTRACE_SETOPTIONS
, pid
, 0, current_ptrace_options
);
571 linux_child_post_attach (int pid
)
573 linux_enable_event_reporting (pid_to_ptid (pid
));
574 linux_enable_tracesysgood (pid_to_ptid (pid
));
578 linux_child_post_startup_inferior (ptid_t ptid
)
580 linux_enable_event_reporting (ptid
);
581 linux_enable_tracesysgood (ptid
);
585 linux_child_follow_fork (struct target_ops
*ops
, int follow_child
)
589 int parent_pid
, child_pid
;
591 block_child_signals (&prev_mask
);
593 has_vforked
= (inferior_thread ()->pending_follow
.kind
594 == TARGET_WAITKIND_VFORKED
);
595 parent_pid
= ptid_get_lwp (inferior_ptid
);
597 parent_pid
= ptid_get_pid (inferior_ptid
);
598 child_pid
= PIDGET (inferior_thread ()->pending_follow
.value
.related_pid
);
601 linux_enable_event_reporting (pid_to_ptid (child_pid
));
604 && !non_stop
/* Non-stop always resumes both branches. */
605 && (!target_is_async_p () || sync_execution
)
606 && !(follow_child
|| detach_fork
|| sched_multi
))
608 /* The parent stays blocked inside the vfork syscall until the
609 child execs or exits. If we don't let the child run, then
610 the parent stays blocked. If we're telling the parent to run
611 in the foreground, the user will not be able to ctrl-c to get
612 back the terminal, effectively hanging the debug session. */
613 fprintf_filtered (gdb_stderr
, _("\
614 Can not resume the parent process over vfork in the foreground while\n\
615 holding the child stopped. Try \"set detach-on-fork\" or \
616 \"set schedule-multiple\".\n"));
617 /* FIXME output string > 80 columns. */
623 struct lwp_info
*child_lp
= NULL
;
625 /* We're already attached to the parent, by default. */
627 /* Detach new forked process? */
630 /* Before detaching from the child, remove all breakpoints
631 from it. If we forked, then this has already been taken
632 care of by infrun.c. If we vforked however, any
633 breakpoint inserted in the parent is visible in the
634 child, even those added while stopped in a vfork
635 catchpoint. This will remove the breakpoints from the
636 parent also, but they'll be reinserted below. */
639 /* keep breakpoints list in sync. */
640 remove_breakpoints_pid (GET_PID (inferior_ptid
));
643 if (info_verbose
|| debug_linux_nat
)
645 target_terminal_ours ();
646 fprintf_filtered (gdb_stdlog
,
647 "Detaching after fork from "
648 "child process %d.\n",
652 ptrace (PTRACE_DETACH
, child_pid
, 0, 0);
656 struct inferior
*parent_inf
, *child_inf
;
657 struct cleanup
*old_chain
;
659 /* Add process to GDB's tables. */
660 child_inf
= add_inferior (child_pid
);
662 parent_inf
= current_inferior ();
663 child_inf
->attach_flag
= parent_inf
->attach_flag
;
664 copy_terminal_info (child_inf
, parent_inf
);
666 old_chain
= save_inferior_ptid ();
667 save_current_program_space ();
669 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
670 add_thread (inferior_ptid
);
671 child_lp
= add_lwp (inferior_ptid
);
672 child_lp
->stopped
= 1;
673 child_lp
->last_resume_kind
= resume_stop
;
675 /* If this is a vfork child, then the address-space is
676 shared with the parent. */
679 child_inf
->pspace
= parent_inf
->pspace
;
680 child_inf
->aspace
= parent_inf
->aspace
;
682 /* The parent will be frozen until the child is done
683 with the shared region. Keep track of the
685 child_inf
->vfork_parent
= parent_inf
;
686 child_inf
->pending_detach
= 0;
687 parent_inf
->vfork_child
= child_inf
;
688 parent_inf
->pending_detach
= 0;
692 child_inf
->aspace
= new_address_space ();
693 child_inf
->pspace
= add_program_space (child_inf
->aspace
);
694 child_inf
->removable
= 1;
695 set_current_program_space (child_inf
->pspace
);
696 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
698 /* Let the shared library layer (solib-svr4) learn about
699 this new process, relocate the cloned exec, pull in
700 shared libraries, and install the solib event
701 breakpoint. If a "cloned-VM" event was propagated
702 better throughout the core, this wouldn't be
704 solib_create_inferior_hook (0);
707 /* Let the thread_db layer learn about this new process. */
708 check_for_thread_db ();
710 do_cleanups (old_chain
);
715 struct lwp_info
*parent_lp
;
716 struct inferior
*parent_inf
;
718 parent_inf
= current_inferior ();
720 /* If we detached from the child, then we have to be careful
721 to not insert breakpoints in the parent until the child
722 is done with the shared memory region. However, if we're
723 staying attached to the child, then we can and should
724 insert breakpoints, so that we can debug it. A
725 subsequent child exec or exit is enough to know when does
726 the child stops using the parent's address space. */
727 parent_inf
->waiting_for_vfork_done
= detach_fork
;
728 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
730 parent_lp
= find_lwp_pid (pid_to_ptid (parent_pid
));
731 gdb_assert (linux_supports_tracefork_flag
>= 0);
733 if (linux_supports_tracevforkdone (0))
736 fprintf_unfiltered (gdb_stdlog
,
737 "LCFF: waiting for VFORK_DONE on %d\n",
739 parent_lp
->stopped
= 1;
741 /* We'll handle the VFORK_DONE event like any other
742 event, in target_wait. */
746 /* We can't insert breakpoints until the child has
747 finished with the shared memory region. We need to
748 wait until that happens. Ideal would be to just
750 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
751 - waitpid (parent_pid, &status, __WALL);
752 However, most architectures can't handle a syscall
753 being traced on the way out if it wasn't traced on
756 We might also think to loop, continuing the child
757 until it exits or gets a SIGTRAP. One problem is
758 that the child might call ptrace with PTRACE_TRACEME.
760 There's no simple and reliable way to figure out when
761 the vforked child will be done with its copy of the
762 shared memory. We could step it out of the syscall,
763 two instructions, let it go, and then single-step the
764 parent once. When we have hardware single-step, this
765 would work; with software single-step it could still
766 be made to work but we'd have to be able to insert
767 single-step breakpoints in the child, and we'd have
768 to insert -just- the single-step breakpoint in the
769 parent. Very awkward.
771 In the end, the best we can do is to make sure it
772 runs for a little while. Hopefully it will be out of
773 range of any breakpoints we reinsert. Usually this
774 is only the single-step breakpoint at vfork's return
778 fprintf_unfiltered (gdb_stdlog
,
779 "LCFF: no VFORK_DONE "
780 "support, sleeping a bit\n");
784 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
785 and leave it pending. The next linux_nat_resume call
786 will notice a pending event, and bypasses actually
787 resuming the inferior. */
788 parent_lp
->status
= 0;
789 parent_lp
->waitstatus
.kind
= TARGET_WAITKIND_VFORK_DONE
;
790 parent_lp
->stopped
= 1;
792 /* If we're in async mode, need to tell the event loop
793 there's something here to process. */
794 if (target_can_async_p ())
801 struct inferior
*parent_inf
, *child_inf
;
802 struct lwp_info
*child_lp
;
803 struct program_space
*parent_pspace
;
805 if (info_verbose
|| debug_linux_nat
)
807 target_terminal_ours ();
809 fprintf_filtered (gdb_stdlog
,
810 _("Attaching after process %d "
811 "vfork to child process %d.\n"),
812 parent_pid
, child_pid
);
814 fprintf_filtered (gdb_stdlog
,
815 _("Attaching after process %d "
816 "fork to child process %d.\n"),
817 parent_pid
, child_pid
);
820 /* Add the new inferior first, so that the target_detach below
821 doesn't unpush the target. */
823 child_inf
= add_inferior (child_pid
);
825 parent_inf
= current_inferior ();
826 child_inf
->attach_flag
= parent_inf
->attach_flag
;
827 copy_terminal_info (child_inf
, parent_inf
);
829 parent_pspace
= parent_inf
->pspace
;
831 /* If we're vforking, we want to hold on to the parent until the
832 child exits or execs. At child exec or exit time we can
833 remove the old breakpoints from the parent and detach or
834 resume debugging it. Otherwise, detach the parent now; we'll
835 want to reuse it's program/address spaces, but we can't set
836 them to the child before removing breakpoints from the
837 parent, otherwise, the breakpoints module could decide to
838 remove breakpoints from the wrong process (since they'd be
839 assigned to the same address space). */
843 gdb_assert (child_inf
->vfork_parent
== NULL
);
844 gdb_assert (parent_inf
->vfork_child
== NULL
);
845 child_inf
->vfork_parent
= parent_inf
;
846 child_inf
->pending_detach
= 0;
847 parent_inf
->vfork_child
= child_inf
;
848 parent_inf
->pending_detach
= detach_fork
;
849 parent_inf
->waiting_for_vfork_done
= 0;
851 else if (detach_fork
)
852 target_detach (NULL
, 0);
854 /* Note that the detach above makes PARENT_INF dangling. */
856 /* Add the child thread to the appropriate lists, and switch to
857 this new thread, before cloning the program space, and
858 informing the solib layer about this new process. */
860 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
861 add_thread (inferior_ptid
);
862 child_lp
= add_lwp (inferior_ptid
);
863 child_lp
->stopped
= 1;
864 child_lp
->last_resume_kind
= resume_stop
;
866 /* If this is a vfork child, then the address-space is shared
867 with the parent. If we detached from the parent, then we can
868 reuse the parent's program/address spaces. */
869 if (has_vforked
|| detach_fork
)
871 child_inf
->pspace
= parent_pspace
;
872 child_inf
->aspace
= child_inf
->pspace
->aspace
;
876 child_inf
->aspace
= new_address_space ();
877 child_inf
->pspace
= add_program_space (child_inf
->aspace
);
878 child_inf
->removable
= 1;
879 set_current_program_space (child_inf
->pspace
);
880 clone_program_space (child_inf
->pspace
, parent_pspace
);
882 /* Let the shared library layer (solib-svr4) learn about
883 this new process, relocate the cloned exec, pull in
884 shared libraries, and install the solib event breakpoint.
885 If a "cloned-VM" event was propagated better throughout
886 the core, this wouldn't be required. */
887 solib_create_inferior_hook (0);
890 /* Let the thread_db layer learn about this new process. */
891 check_for_thread_db ();
894 restore_child_signals_mask (&prev_mask
);
900 linux_child_insert_fork_catchpoint (int pid
)
902 return !linux_supports_tracefork (pid
);
906 linux_child_remove_fork_catchpoint (int pid
)
912 linux_child_insert_vfork_catchpoint (int pid
)
914 return !linux_supports_tracefork (pid
);
918 linux_child_remove_vfork_catchpoint (int pid
)
924 linux_child_insert_exec_catchpoint (int pid
)
926 return !linux_supports_tracefork (pid
);
930 linux_child_remove_exec_catchpoint (int pid
)
936 linux_child_set_syscall_catchpoint (int pid
, int needed
, int any_count
,
937 int table_size
, int *table
)
939 if (!linux_supports_tracesysgood (pid
))
942 /* On GNU/Linux, we ignore the arguments. It means that we only
943 enable the syscall catchpoints, but do not disable them.
945 Also, we do not use the `table' information because we do not
946 filter system calls here. We let GDB do the logic for us. */
950 /* On GNU/Linux there are no real LWP's. The closest thing to LWP's
951 are processes sharing the same VM space. A multi-threaded process
952 is basically a group of such processes. However, such a grouping
953 is almost entirely a user-space issue; the kernel doesn't enforce
954 such a grouping at all (this might change in the future). In
955 general, we'll rely on the threads library (i.e. the GNU/Linux
956 Threads library) to provide such a grouping.
958 It is perfectly well possible to write a multi-threaded application
959 without the assistance of a threads library, by using the clone
960 system call directly. This module should be able to give some
961 rudimentary support for debugging such applications if developers
962 specify the CLONE_PTRACE flag in the clone system call, and are
963 using the Linux kernel 2.4 or above.
965 Note that there are some peculiarities in GNU/Linux that affect
968 - In general one should specify the __WCLONE flag to waitpid in
969 order to make it report events for any of the cloned processes
970 (and leave it out for the initial process). However, if a cloned
971 process has exited the exit status is only reported if the
972 __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
973 we cannot use it since GDB must work on older systems too.
975 - When a traced, cloned process exits and is waited for by the
976 debugger, the kernel reassigns it to the original parent and
977 keeps it around as a "zombie". Somehow, the GNU/Linux Threads
978 library doesn't notice this, which leads to the "zombie problem":
979 When debugged a multi-threaded process that spawns a lot of
980 threads will run out of processes, even if the threads exit,
981 because the "zombies" stay around. */
983 /* List of known LWPs. */
984 struct lwp_info
*lwp_list
;
987 /* Original signal mask. */
988 static sigset_t normal_mask
;
990 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
991 _initialize_linux_nat. */
992 static sigset_t suspend_mask
;
994 /* Signals to block to make that sigsuspend work. */
995 static sigset_t blocked_mask
;
997 /* SIGCHLD action. */
998 struct sigaction sigchld_action
;
1000 /* Block child signals (SIGCHLD and linux threads signals), and store
1001 the previous mask in PREV_MASK. */
1004 block_child_signals (sigset_t
*prev_mask
)
1006 /* Make sure SIGCHLD is blocked. */
1007 if (!sigismember (&blocked_mask
, SIGCHLD
))
1008 sigaddset (&blocked_mask
, SIGCHLD
);
1010 sigprocmask (SIG_BLOCK
, &blocked_mask
, prev_mask
);
1013 /* Restore child signals mask, previously returned by
1014 block_child_signals. */
1017 restore_child_signals_mask (sigset_t
*prev_mask
)
1019 sigprocmask (SIG_SETMASK
, prev_mask
, NULL
);
1022 /* Mask of signals to pass directly to the inferior. */
1023 static sigset_t pass_mask
;
1025 /* Update signals to pass to the inferior. */
1027 linux_nat_pass_signals (int numsigs
, unsigned char *pass_signals
)
1031 sigemptyset (&pass_mask
);
1033 for (signo
= 1; signo
< NSIG
; signo
++)
1035 int target_signo
= target_signal_from_host (signo
);
1036 if (target_signo
< numsigs
&& pass_signals
[target_signo
])
1037 sigaddset (&pass_mask
, signo
);
1043 /* Prototypes for local functions. */
1044 static int stop_wait_callback (struct lwp_info
*lp
, void *data
);
1045 static int linux_thread_alive (ptid_t ptid
);
1046 static char *linux_child_pid_to_exec_file (int pid
);
1049 /* Convert wait status STATUS to a string. Used for printing debug
1053 status_to_str (int status
)
1055 static char buf
[64];
1057 if (WIFSTOPPED (status
))
1059 if (WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
1060 snprintf (buf
, sizeof (buf
), "%s (stopped at syscall)",
1061 strsignal (SIGTRAP
));
1063 snprintf (buf
, sizeof (buf
), "%s (stopped)",
1064 strsignal (WSTOPSIG (status
)));
1066 else if (WIFSIGNALED (status
))
1067 snprintf (buf
, sizeof (buf
), "%s (terminated)",
1068 strsignal (WTERMSIG (status
)));
1070 snprintf (buf
, sizeof (buf
), "%d (exited)", WEXITSTATUS (status
));
1075 /* Remove all LWPs belong to PID from the lwp list. */
1078 purge_lwp_list (int pid
)
1080 struct lwp_info
*lp
, *lpprev
, *lpnext
;
1084 for (lp
= lwp_list
; lp
; lp
= lpnext
)
1088 if (ptid_get_pid (lp
->ptid
) == pid
)
1091 lwp_list
= lp
->next
;
1093 lpprev
->next
= lp
->next
;
1102 /* Return the number of known LWPs in the tgid given by PID. */
1108 struct lwp_info
*lp
;
1110 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
1111 if (ptid_get_pid (lp
->ptid
) == pid
)
1117 /* Add the LWP specified by PID to the list. Return a pointer to the
1118 structure describing the new LWP. The LWP should already be stopped
1119 (with an exception for the very first LWP). */
1121 static struct lwp_info
*
1122 add_lwp (ptid_t ptid
)
1124 struct lwp_info
*lp
;
1126 gdb_assert (is_lwp (ptid
));
1128 lp
= (struct lwp_info
*) xmalloc (sizeof (struct lwp_info
));
1130 memset (lp
, 0, sizeof (struct lwp_info
));
1132 lp
->last_resume_kind
= resume_continue
;
1133 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
1138 lp
->next
= lwp_list
;
1141 if (num_lwps (GET_PID (ptid
)) > 1 && linux_nat_new_thread
!= NULL
)
1142 linux_nat_new_thread (ptid
);
1147 /* Remove the LWP specified by PID from the list. */
1150 delete_lwp (ptid_t ptid
)
1152 struct lwp_info
*lp
, *lpprev
;
1156 for (lp
= lwp_list
; lp
; lpprev
= lp
, lp
= lp
->next
)
1157 if (ptid_equal (lp
->ptid
, ptid
))
1164 lpprev
->next
= lp
->next
;
1166 lwp_list
= lp
->next
;
1171 /* Return a pointer to the structure describing the LWP corresponding
1172 to PID. If no corresponding LWP could be found, return NULL. */
1174 static struct lwp_info
*
1175 find_lwp_pid (ptid_t ptid
)
1177 struct lwp_info
*lp
;
1181 lwp
= GET_LWP (ptid
);
1183 lwp
= GET_PID (ptid
);
1185 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
1186 if (lwp
== GET_LWP (lp
->ptid
))
1192 /* Call CALLBACK with its second argument set to DATA for every LWP in
1193 the list. If CALLBACK returns 1 for a particular LWP, return a
1194 pointer to the structure describing that LWP immediately.
1195 Otherwise return NULL. */
1198 iterate_over_lwps (ptid_t filter
,
1199 int (*callback
) (struct lwp_info
*, void *),
1202 struct lwp_info
*lp
, *lpnext
;
1204 for (lp
= lwp_list
; lp
; lp
= lpnext
)
1208 if (ptid_match (lp
->ptid
, filter
))
1210 if ((*callback
) (lp
, data
))
1218 /* Update our internal state when changing from one checkpoint to
1219 another indicated by NEW_PTID. We can only switch single-threaded
1220 applications, so we only create one new LWP, and the previous list
1224 linux_nat_switch_fork (ptid_t new_ptid
)
1226 struct lwp_info
*lp
;
1228 purge_lwp_list (GET_PID (inferior_ptid
));
1230 lp
= add_lwp (new_ptid
);
1233 /* This changes the thread's ptid while preserving the gdb thread
1234 num. Also changes the inferior pid, while preserving the
1236 thread_change_ptid (inferior_ptid
, new_ptid
);
1238 /* We've just told GDB core that the thread changed target id, but,
1239 in fact, it really is a different thread, with different register
1241 registers_changed ();
1244 /* Handle the exit of a single thread LP. */
1247 exit_lwp (struct lwp_info
*lp
)
1249 struct thread_info
*th
= find_thread_ptid (lp
->ptid
);
1253 if (print_thread_events
)
1254 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp
->ptid
));
1256 delete_thread (lp
->ptid
);
1259 delete_lwp (lp
->ptid
);
1262 /* Detect `T (stopped)' in `/proc/PID/status'.
1263 Other states including `T (tracing stop)' are reported as false. */
1266 pid_is_stopped (pid_t pid
)
1272 snprintf (buf
, sizeof (buf
), "/proc/%d/status", (int) pid
);
1273 status_file
= fopen (buf
, "r");
1274 if (status_file
!= NULL
)
1278 while (fgets (buf
, sizeof (buf
), status_file
))
1280 if (strncmp (buf
, "State:", 6) == 0)
1286 if (have_state
&& strstr (buf
, "T (stopped)") != NULL
)
1288 fclose (status_file
);
1293 /* Wait for the LWP specified by LP, which we have just attached to.
1294 Returns a wait status for that LWP, to cache. */
1297 linux_nat_post_attach_wait (ptid_t ptid
, int first
, int *cloned
,
1300 pid_t new_pid
, pid
= GET_LWP (ptid
);
1303 if (pid_is_stopped (pid
))
1305 if (debug_linux_nat
)
1306 fprintf_unfiltered (gdb_stdlog
,
1307 "LNPAW: Attaching to a stopped process\n");
1309 /* The process is definitely stopped. It is in a job control
1310 stop, unless the kernel predates the TASK_STOPPED /
1311 TASK_TRACED distinction, in which case it might be in a
1312 ptrace stop. Make sure it is in a ptrace stop; from there we
1313 can kill it, signal it, et cetera.
1315 First make sure there is a pending SIGSTOP. Since we are
1316 already attached, the process can not transition from stopped
1317 to running without a PTRACE_CONT; so we know this signal will
1318 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1319 probably already in the queue (unless this kernel is old
1320 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1321 is not an RT signal, it can only be queued once. */
1322 kill_lwp (pid
, SIGSTOP
);
1324 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1325 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1326 ptrace (PTRACE_CONT
, pid
, 0, 0);
1329 /* Make sure the initial process is stopped. The user-level threads
1330 layer might want to poke around in the inferior, and that won't
1331 work if things haven't stabilized yet. */
1332 new_pid
= my_waitpid (pid
, &status
, 0);
1333 if (new_pid
== -1 && errno
== ECHILD
)
1336 warning (_("%s is a cloned process"), target_pid_to_str (ptid
));
1338 /* Try again with __WCLONE to check cloned processes. */
1339 new_pid
= my_waitpid (pid
, &status
, __WCLONE
);
1343 gdb_assert (pid
== new_pid
);
1345 if (!WIFSTOPPED (status
))
1347 /* The pid we tried to attach has apparently just exited. */
1348 if (debug_linux_nat
)
1349 fprintf_unfiltered (gdb_stdlog
, "LNPAW: Failed to stop %d: %s",
1350 pid
, status_to_str (status
));
1354 if (WSTOPSIG (status
) != SIGSTOP
)
1357 if (debug_linux_nat
)
1358 fprintf_unfiltered (gdb_stdlog
,
1359 "LNPAW: Received %s after attaching\n",
1360 status_to_str (status
));
1366 /* Attach to the LWP specified by PID. Return 0 if successful, -1 if
1367 the new LWP could not be attached, or 1 if we're already auto
1368 attached to this thread, but haven't processed the
1369 PTRACE_EVENT_CLONE event of its parent thread, so we just ignore
1370 its existance, without considering it an error. */
1373 lin_lwp_attach_lwp (ptid_t ptid
)
1375 struct lwp_info
*lp
;
1379 gdb_assert (is_lwp (ptid
));
1381 block_child_signals (&prev_mask
);
1383 lp
= find_lwp_pid (ptid
);
1384 lwpid
= GET_LWP (ptid
);
1386 /* We assume that we're already attached to any LWP that has an id
1387 equal to the overall process id, and to any LWP that is already
1388 in our list of LWPs. If we're not seeing exit events from threads
1389 and we've had PID wraparound since we last tried to stop all threads,
1390 this assumption might be wrong; fortunately, this is very unlikely
1392 if (lwpid
!= GET_PID (ptid
) && lp
== NULL
)
1394 int status
, cloned
= 0, signalled
= 0;
1396 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) < 0)
1398 if (linux_supports_tracefork_flag
)
1400 /* If we haven't stopped all threads when we get here,
1401 we may have seen a thread listed in thread_db's list,
1402 but not processed the PTRACE_EVENT_CLONE yet. If
1403 that's the case, ignore this new thread, and let
1404 normal event handling discover it later. */
1405 if (in_pid_list_p (stopped_pids
, lwpid
))
1407 /* We've already seen this thread stop, but we
1408 haven't seen the PTRACE_EVENT_CLONE extended
1410 restore_child_signals_mask (&prev_mask
);
1418 /* See if we've got a stop for this new child
1419 pending. If so, we're already attached. */
1420 new_pid
= my_waitpid (lwpid
, &status
, WNOHANG
);
1421 if (new_pid
== -1 && errno
== ECHILD
)
1422 new_pid
= my_waitpid (lwpid
, &status
, __WCLONE
| WNOHANG
);
1425 if (WIFSTOPPED (status
))
1426 add_to_pid_list (&stopped_pids
, lwpid
, status
);
1428 restore_child_signals_mask (&prev_mask
);
1434 /* If we fail to attach to the thread, issue a warning,
1435 but continue. One way this can happen is if thread
1436 creation is interrupted; as of Linux kernel 2.6.19, a
1437 bug may place threads in the thread list and then fail
1439 warning (_("Can't attach %s: %s"), target_pid_to_str (ptid
),
1440 safe_strerror (errno
));
1441 restore_child_signals_mask (&prev_mask
);
1445 if (debug_linux_nat
)
1446 fprintf_unfiltered (gdb_stdlog
,
1447 "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
1448 target_pid_to_str (ptid
));
1450 status
= linux_nat_post_attach_wait (ptid
, 0, &cloned
, &signalled
);
1451 if (!WIFSTOPPED (status
))
1453 restore_child_signals_mask (&prev_mask
);
1457 lp
= add_lwp (ptid
);
1459 lp
->cloned
= cloned
;
1460 lp
->signalled
= signalled
;
1461 if (WSTOPSIG (status
) != SIGSTOP
)
1464 lp
->status
= status
;
1467 target_post_attach (GET_LWP (lp
->ptid
));
1469 if (debug_linux_nat
)
1471 fprintf_unfiltered (gdb_stdlog
,
1472 "LLAL: waitpid %s received %s\n",
1473 target_pid_to_str (ptid
),
1474 status_to_str (status
));
1479 /* We assume that the LWP representing the original process is
1480 already stopped. Mark it as stopped in the data structure
1481 that the GNU/linux ptrace layer uses to keep track of
1482 threads. Note that this won't have already been done since
1483 the main thread will have, we assume, been stopped by an
1484 attach from a different layer. */
1486 lp
= add_lwp (ptid
);
1490 lp
->last_resume_kind
= resume_stop
;
1491 restore_child_signals_mask (&prev_mask
);
1496 linux_nat_create_inferior (struct target_ops
*ops
,
1497 char *exec_file
, char *allargs
, char **env
,
1500 #ifdef HAVE_PERSONALITY
1501 int personality_orig
= 0, personality_set
= 0;
1502 #endif /* HAVE_PERSONALITY */
1504 /* The fork_child mechanism is synchronous and calls target_wait, so
1505 we have to mask the async mode. */
1507 #ifdef HAVE_PERSONALITY
1508 if (disable_randomization
)
1511 personality_orig
= personality (0xffffffff);
1512 if (errno
== 0 && !(personality_orig
& ADDR_NO_RANDOMIZE
))
1514 personality_set
= 1;
1515 personality (personality_orig
| ADDR_NO_RANDOMIZE
);
1517 if (errno
!= 0 || (personality_set
1518 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE
)))
1519 warning (_("Error disabling address space randomization: %s"),
1520 safe_strerror (errno
));
1522 #endif /* HAVE_PERSONALITY */
1524 /* Make sure we report all signals during startup. */
1525 linux_nat_pass_signals (0, NULL
);
1527 linux_ops
->to_create_inferior (ops
, exec_file
, allargs
, env
, from_tty
);
1529 #ifdef HAVE_PERSONALITY
1530 if (personality_set
)
1533 personality (personality_orig
);
1535 warning (_("Error restoring address space randomization: %s"),
1536 safe_strerror (errno
));
1538 #endif /* HAVE_PERSONALITY */
1542 linux_nat_attach (struct target_ops
*ops
, char *args
, int from_tty
)
1544 struct lwp_info
*lp
;
1548 /* Make sure we report all signals during attach. */
1549 linux_nat_pass_signals (0, NULL
);
1551 linux_ops
->to_attach (ops
, args
, from_tty
);
1553 /* The ptrace base target adds the main thread with (pid,0,0)
1554 format. Decorate it with lwp info. */
1555 ptid
= BUILD_LWP (GET_PID (inferior_ptid
), GET_PID (inferior_ptid
));
1556 thread_change_ptid (inferior_ptid
, ptid
);
1558 /* Add the initial process as the first LWP to the list. */
1559 lp
= add_lwp (ptid
);
1561 status
= linux_nat_post_attach_wait (lp
->ptid
, 1, &lp
->cloned
,
1563 if (!WIFSTOPPED (status
))
1565 if (WIFEXITED (status
))
1567 int exit_code
= WEXITSTATUS (status
);
1569 target_terminal_ours ();
1570 target_mourn_inferior ();
1572 error (_("Unable to attach: program exited normally."));
1574 error (_("Unable to attach: program exited with code %d."),
1577 else if (WIFSIGNALED (status
))
1579 enum target_signal signo
;
1581 target_terminal_ours ();
1582 target_mourn_inferior ();
1584 signo
= target_signal_from_host (WTERMSIG (status
));
1585 error (_("Unable to attach: program terminated with signal "
1587 target_signal_to_name (signo
),
1588 target_signal_to_string (signo
));
1591 internal_error (__FILE__
, __LINE__
,
1592 _("unexpected status %d for PID %ld"),
1593 status
, (long) GET_LWP (ptid
));
1598 /* Save the wait status to report later. */
1600 if (debug_linux_nat
)
1601 fprintf_unfiltered (gdb_stdlog
,
1602 "LNA: waitpid %ld, saving status %s\n",
1603 (long) GET_PID (lp
->ptid
), status_to_str (status
));
1605 lp
->status
= status
;
1607 if (target_can_async_p ())
1608 target_async (inferior_event_handler
, 0);
1611 /* Get pending status of LP. */
1613 get_pending_status (struct lwp_info
*lp
, int *status
)
1615 enum target_signal signo
= TARGET_SIGNAL_0
;
1617 /* If we paused threads momentarily, we may have stored pending
1618 events in lp->status or lp->waitstatus (see stop_wait_callback),
1619 and GDB core hasn't seen any signal for those threads.
1620 Otherwise, the last signal reported to the core is found in the
1621 thread object's stop_signal.
1623 There's a corner case that isn't handled here at present. Only
1624 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1625 stop_signal make sense as a real signal to pass to the inferior.
1626 Some catchpoint related events, like
1627 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1628 to TARGET_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1629 those traps are debug API (ptrace in our case) related and
1630 induced; the inferior wouldn't see them if it wasn't being
1631 traced. Hence, we should never pass them to the inferior, even
1632 when set to pass state. Since this corner case isn't handled by
1633 infrun.c when proceeding with a signal, for consistency, neither
1634 do we handle it here (or elsewhere in the file we check for
1635 signal pass state). Normally SIGTRAP isn't set to pass state, so
1636 this is really a corner case. */
1638 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
1639 signo
= TARGET_SIGNAL_0
; /* a pending ptrace event, not a real signal. */
1640 else if (lp
->status
)
1641 signo
= target_signal_from_host (WSTOPSIG (lp
->status
));
1642 else if (non_stop
&& !is_executing (lp
->ptid
))
1644 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1646 signo
= tp
->suspend
.stop_signal
;
1650 struct target_waitstatus last
;
1653 get_last_target_status (&last_ptid
, &last
);
1655 if (GET_LWP (lp
->ptid
) == GET_LWP (last_ptid
))
1657 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1659 signo
= tp
->suspend
.stop_signal
;
1665 if (signo
== TARGET_SIGNAL_0
)
1667 if (debug_linux_nat
)
1668 fprintf_unfiltered (gdb_stdlog
,
1669 "GPT: lwp %s has no pending signal\n",
1670 target_pid_to_str (lp
->ptid
));
1672 else if (!signal_pass_state (signo
))
1674 if (debug_linux_nat
)
1675 fprintf_unfiltered (gdb_stdlog
,
1676 "GPT: lwp %s had signal %s, "
1677 "but it is in no pass state\n",
1678 target_pid_to_str (lp
->ptid
),
1679 target_signal_to_string (signo
));
1683 *status
= W_STOPCODE (target_signal_to_host (signo
));
1685 if (debug_linux_nat
)
1686 fprintf_unfiltered (gdb_stdlog
,
1687 "GPT: lwp %s has pending signal %s\n",
1688 target_pid_to_str (lp
->ptid
),
1689 target_signal_to_string (signo
));
1696 detach_callback (struct lwp_info
*lp
, void *data
)
1698 gdb_assert (lp
->status
== 0 || WIFSTOPPED (lp
->status
));
1700 if (debug_linux_nat
&& lp
->status
)
1701 fprintf_unfiltered (gdb_stdlog
, "DC: Pending %s for %s on detach.\n",
1702 strsignal (WSTOPSIG (lp
->status
)),
1703 target_pid_to_str (lp
->ptid
));
1705 /* If there is a pending SIGSTOP, get rid of it. */
1708 if (debug_linux_nat
)
1709 fprintf_unfiltered (gdb_stdlog
,
1710 "DC: Sending SIGCONT to %s\n",
1711 target_pid_to_str (lp
->ptid
));
1713 kill_lwp (GET_LWP (lp
->ptid
), SIGCONT
);
1717 /* We don't actually detach from the LWP that has an id equal to the
1718 overall process id just yet. */
1719 if (GET_LWP (lp
->ptid
) != GET_PID (lp
->ptid
))
1723 /* Pass on any pending signal for this LWP. */
1724 get_pending_status (lp
, &status
);
1727 if (ptrace (PTRACE_DETACH
, GET_LWP (lp
->ptid
), 0,
1728 WSTOPSIG (status
)) < 0)
1729 error (_("Can't detach %s: %s"), target_pid_to_str (lp
->ptid
),
1730 safe_strerror (errno
));
1732 if (debug_linux_nat
)
1733 fprintf_unfiltered (gdb_stdlog
,
1734 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1735 target_pid_to_str (lp
->ptid
),
1736 strsignal (WSTOPSIG (status
)));
1738 delete_lwp (lp
->ptid
);
1745 linux_nat_detach (struct target_ops
*ops
, char *args
, int from_tty
)
1749 struct lwp_info
*main_lwp
;
1751 pid
= GET_PID (inferior_ptid
);
1753 if (target_can_async_p ())
1754 linux_nat_async (NULL
, 0);
1756 /* Stop all threads before detaching. ptrace requires that the
1757 thread is stopped to sucessfully detach. */
1758 iterate_over_lwps (pid_to_ptid (pid
), stop_callback
, NULL
);
1759 /* ... and wait until all of them have reported back that
1760 they're no longer running. */
1761 iterate_over_lwps (pid_to_ptid (pid
), stop_wait_callback
, NULL
);
1763 iterate_over_lwps (pid_to_ptid (pid
), detach_callback
, NULL
);
1765 /* Only the initial process should be left right now. */
1766 gdb_assert (num_lwps (GET_PID (inferior_ptid
)) == 1);
1768 main_lwp
= find_lwp_pid (pid_to_ptid (pid
));
1770 /* Pass on any pending signal for the last LWP. */
1771 if ((args
== NULL
|| *args
== '\0')
1772 && get_pending_status (main_lwp
, &status
) != -1
1773 && WIFSTOPPED (status
))
1775 /* Put the signal number in ARGS so that inf_ptrace_detach will
1776 pass it along with PTRACE_DETACH. */
1778 sprintf (args
, "%d", (int) WSTOPSIG (status
));
1779 if (debug_linux_nat
)
1780 fprintf_unfiltered (gdb_stdlog
,
1781 "LND: Sending signal %s to %s\n",
1783 target_pid_to_str (main_lwp
->ptid
));
1786 delete_lwp (main_lwp
->ptid
);
1788 if (forks_exist_p ())
1790 /* Multi-fork case. The current inferior_ptid is being detached
1791 from, but there are other viable forks to debug. Detach from
1792 the current fork, and context-switch to the first
1794 linux_fork_detach (args
, from_tty
);
1796 if (non_stop
&& target_can_async_p ())
1797 target_async (inferior_event_handler
, 0);
1800 linux_ops
->to_detach (ops
, args
, from_tty
);
1806 resume_lwp (struct lwp_info
*lp
, int step
)
1810 struct inferior
*inf
= find_inferior_pid (GET_PID (lp
->ptid
));
1812 if (inf
->vfork_child
!= NULL
)
1814 if (debug_linux_nat
)
1815 fprintf_unfiltered (gdb_stdlog
,
1816 "RC: Not resuming %s (vfork parent)\n",
1817 target_pid_to_str (lp
->ptid
));
1819 else if (lp
->status
== 0
1820 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
1822 if (debug_linux_nat
)
1823 fprintf_unfiltered (gdb_stdlog
,
1824 "RC: PTRACE_CONT %s, 0, 0 (resuming sibling)\n",
1825 target_pid_to_str (lp
->ptid
));
1827 linux_ops
->to_resume (linux_ops
,
1828 pid_to_ptid (GET_LWP (lp
->ptid
)),
1829 step
, TARGET_SIGNAL_0
);
1832 memset (&lp
->siginfo
, 0, sizeof (lp
->siginfo
));
1833 lp
->stopped_by_watchpoint
= 0;
1837 if (debug_linux_nat
)
1838 fprintf_unfiltered (gdb_stdlog
,
1839 "RC: Not resuming sibling %s (has pending)\n",
1840 target_pid_to_str (lp
->ptid
));
1845 if (debug_linux_nat
)
1846 fprintf_unfiltered (gdb_stdlog
,
1847 "RC: Not resuming sibling %s (not stopped)\n",
1848 target_pid_to_str (lp
->ptid
));
1853 resume_callback (struct lwp_info
*lp
, void *data
)
1860 resume_clear_callback (struct lwp_info
*lp
, void *data
)
1863 lp
->last_resume_kind
= resume_stop
;
1868 resume_set_callback (struct lwp_info
*lp
, void *data
)
1871 lp
->last_resume_kind
= resume_continue
;
1876 linux_nat_resume (struct target_ops
*ops
,
1877 ptid_t ptid
, int step
, enum target_signal signo
)
1880 struct lwp_info
*lp
;
1883 if (debug_linux_nat
)
1884 fprintf_unfiltered (gdb_stdlog
,
1885 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1886 step
? "step" : "resume",
1887 target_pid_to_str (ptid
),
1888 (signo
!= TARGET_SIGNAL_0
1889 ? strsignal (target_signal_to_host (signo
)) : "0"),
1890 target_pid_to_str (inferior_ptid
));
1892 block_child_signals (&prev_mask
);
1894 /* A specific PTID means `step only this process id'. */
1895 resume_many
= (ptid_equal (minus_one_ptid
, ptid
)
1896 || ptid_is_pid (ptid
));
1898 /* Mark the lwps we're resuming as resumed. */
1899 iterate_over_lwps (ptid
, resume_set_callback
, NULL
);
1901 /* See if it's the current inferior that should be handled
1904 lp
= find_lwp_pid (inferior_ptid
);
1906 lp
= find_lwp_pid (ptid
);
1907 gdb_assert (lp
!= NULL
);
1909 /* Remember if we're stepping. */
1911 lp
->last_resume_kind
= step
? resume_step
: resume_continue
;
1913 /* If we have a pending wait status for this thread, there is no
1914 point in resuming the process. But first make sure that
1915 linux_nat_wait won't preemptively handle the event - we
1916 should never take this short-circuit if we are going to
1917 leave LP running, since we have skipped resuming all the
1918 other threads. This bit of code needs to be synchronized
1919 with linux_nat_wait. */
1921 if (lp
->status
&& WIFSTOPPED (lp
->status
))
1924 && WSTOPSIG (lp
->status
)
1925 && sigismember (&pass_mask
, WSTOPSIG (lp
->status
)))
1927 if (debug_linux_nat
)
1928 fprintf_unfiltered (gdb_stdlog
,
1929 "LLR: Not short circuiting for ignored "
1930 "status 0x%x\n", lp
->status
);
1932 /* FIXME: What should we do if we are supposed to continue
1933 this thread with a signal? */
1934 gdb_assert (signo
== TARGET_SIGNAL_0
);
1935 signo
= target_signal_from_host (WSTOPSIG (lp
->status
));
1940 if (lp
->status
|| lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
1942 /* FIXME: What should we do if we are supposed to continue
1943 this thread with a signal? */
1944 gdb_assert (signo
== TARGET_SIGNAL_0
);
1946 if (debug_linux_nat
)
1947 fprintf_unfiltered (gdb_stdlog
,
1948 "LLR: Short circuiting for status 0x%x\n",
1951 restore_child_signals_mask (&prev_mask
);
1952 if (target_can_async_p ())
1954 target_async (inferior_event_handler
, 0);
1955 /* Tell the event loop we have something to process. */
1961 /* Mark LWP as not stopped to prevent it from being continued by
1966 iterate_over_lwps (ptid
, resume_callback
, NULL
);
1968 /* Convert to something the lower layer understands. */
1969 ptid
= pid_to_ptid (GET_LWP (lp
->ptid
));
1971 linux_ops
->to_resume (linux_ops
, ptid
, step
, signo
);
1972 memset (&lp
->siginfo
, 0, sizeof (lp
->siginfo
));
1973 lp
->stopped_by_watchpoint
= 0;
1975 if (debug_linux_nat
)
1976 fprintf_unfiltered (gdb_stdlog
,
1977 "LLR: %s %s, %s (resume event thread)\n",
1978 step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1979 target_pid_to_str (ptid
),
1980 (signo
!= TARGET_SIGNAL_0
1981 ? strsignal (target_signal_to_host (signo
)) : "0"));
1983 restore_child_signals_mask (&prev_mask
);
1984 if (target_can_async_p ())
1985 target_async (inferior_event_handler
, 0);
1988 /* Send a signal to an LWP. */
1991 kill_lwp (int lwpid
, int signo
)
1993 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1994 fails, then we are not using nptl threads and we should be using kill. */
1996 #ifdef HAVE_TKILL_SYSCALL
1998 static int tkill_failed
;
2005 ret
= syscall (__NR_tkill
, lwpid
, signo
);
2006 if (errno
!= ENOSYS
)
2013 return kill (lwpid
, signo
);
2016 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
2017 event, check if the core is interested in it: if not, ignore the
2018 event, and keep waiting; otherwise, we need to toggle the LWP's
2019 syscall entry/exit status, since the ptrace event itself doesn't
2020 indicate it, and report the trap to higher layers. */
2023 linux_handle_syscall_trap (struct lwp_info
*lp
, int stopping
)
2025 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
2026 struct gdbarch
*gdbarch
= target_thread_architecture (lp
->ptid
);
2027 int syscall_number
= (int) gdbarch_get_syscall_number (gdbarch
, lp
->ptid
);
2031 /* If we're stopping threads, there's a SIGSTOP pending, which
2032 makes it so that the LWP reports an immediate syscall return,
2033 followed by the SIGSTOP. Skip seeing that "return" using
2034 PTRACE_CONT directly, and let stop_wait_callback collect the
2035 SIGSTOP. Later when the thread is resumed, a new syscall
2036 entry event. If we didn't do this (and returned 0), we'd
2037 leave a syscall entry pending, and our caller, by using
2038 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
2039 itself. Later, when the user re-resumes this LWP, we'd see
2040 another syscall entry event and we'd mistake it for a return.
2042 If stop_wait_callback didn't force the SIGSTOP out of the LWP
2043 (leaving immediately with LWP->signalled set, without issuing
2044 a PTRACE_CONT), it would still be problematic to leave this
2045 syscall enter pending, as later when the thread is resumed,
2046 it would then see the same syscall exit mentioned above,
2047 followed by the delayed SIGSTOP, while the syscall didn't
2048 actually get to execute. It seems it would be even more
2049 confusing to the user. */
2051 if (debug_linux_nat
)
2052 fprintf_unfiltered (gdb_stdlog
,
2053 "LHST: ignoring syscall %d "
2054 "for LWP %ld (stopping threads), "
2055 "resuming with PTRACE_CONT for SIGSTOP\n",
2057 GET_LWP (lp
->ptid
));
2059 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2060 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2064 if (catch_syscall_enabled ())
2066 /* Always update the entry/return state, even if this particular
2067 syscall isn't interesting to the core now. In async mode,
2068 the user could install a new catchpoint for this syscall
2069 between syscall enter/return, and we'll need to know to
2070 report a syscall return if that happens. */
2071 lp
->syscall_state
= (lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
2072 ? TARGET_WAITKIND_SYSCALL_RETURN
2073 : TARGET_WAITKIND_SYSCALL_ENTRY
);
2075 if (catching_syscall_number (syscall_number
))
2077 /* Alright, an event to report. */
2078 ourstatus
->kind
= lp
->syscall_state
;
2079 ourstatus
->value
.syscall_number
= syscall_number
;
2081 if (debug_linux_nat
)
2082 fprintf_unfiltered (gdb_stdlog
,
2083 "LHST: stopping for %s of syscall %d"
2086 == TARGET_WAITKIND_SYSCALL_ENTRY
2087 ? "entry" : "return",
2089 GET_LWP (lp
->ptid
));
2093 if (debug_linux_nat
)
2094 fprintf_unfiltered (gdb_stdlog
,
2095 "LHST: ignoring %s of syscall %d "
2097 lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
2098 ? "entry" : "return",
2100 GET_LWP (lp
->ptid
));
2104 /* If we had been syscall tracing, and hence used PT_SYSCALL
2105 before on this LWP, it could happen that the user removes all
2106 syscall catchpoints before we get to process this event.
2107 There are two noteworthy issues here:
2109 - When stopped at a syscall entry event, resuming with
2110 PT_STEP still resumes executing the syscall and reports a
2113 - Only PT_SYSCALL catches syscall enters. If we last
2114 single-stepped this thread, then this event can't be a
2115 syscall enter. If we last single-stepped this thread, this
2116 has to be a syscall exit.
2118 The points above mean that the next resume, be it PT_STEP or
2119 PT_CONTINUE, can not trigger a syscall trace event. */
2120 if (debug_linux_nat
)
2121 fprintf_unfiltered (gdb_stdlog
,
2122 "LHST: caught syscall event "
2123 "with no syscall catchpoints."
2124 " %d for LWP %ld, ignoring\n",
2126 GET_LWP (lp
->ptid
));
2127 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2130 /* The core isn't interested in this event. For efficiency, avoid
2131 stopping all threads only to have the core resume them all again.
2132 Since we're not stopping threads, if we're still syscall tracing
2133 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
2134 subsequent syscall. Simply resume using the inf-ptrace layer,
2135 which knows when to use PT_SYSCALL or PT_CONTINUE. */
2137 /* Note that gdbarch_get_syscall_number may access registers, hence
2139 registers_changed ();
2140 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
2141 lp
->step
, TARGET_SIGNAL_0
);
2145 /* Handle a GNU/Linux extended wait response. If we see a clone
2146 event, we need to add the new LWP to our list (and not report the
2147 trap to higher layers). This function returns non-zero if the
2148 event should be ignored and we should wait again. If STOPPING is
2149 true, the new LWP remains stopped, otherwise it is continued. */
2152 linux_handle_extended_wait (struct lwp_info
*lp
, int status
,
2155 int pid
= GET_LWP (lp
->ptid
);
2156 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
2157 int event
= status
>> 16;
2159 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
2160 || event
== PTRACE_EVENT_CLONE
)
2162 unsigned long new_pid
;
2165 ptrace (PTRACE_GETEVENTMSG
, pid
, 0, &new_pid
);
2167 /* If we haven't already seen the new PID stop, wait for it now. */
2168 if (! pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
2170 /* The new child has a pending SIGSTOP. We can't affect it until it
2171 hits the SIGSTOP, but we're already attached. */
2172 ret
= my_waitpid (new_pid
, &status
,
2173 (event
== PTRACE_EVENT_CLONE
) ? __WCLONE
: 0);
2175 perror_with_name (_("waiting for new child"));
2176 else if (ret
!= new_pid
)
2177 internal_error (__FILE__
, __LINE__
,
2178 _("wait returned unexpected PID %d"), ret
);
2179 else if (!WIFSTOPPED (status
))
2180 internal_error (__FILE__
, __LINE__
,
2181 _("wait returned unexpected status 0x%x"), status
);
2184 ourstatus
->value
.related_pid
= ptid_build (new_pid
, new_pid
, 0);
2186 if (event
== PTRACE_EVENT_FORK
2187 && linux_fork_checkpointing_p (GET_PID (lp
->ptid
)))
2189 /* Handle checkpointing by linux-fork.c here as a special
2190 case. We don't want the follow-fork-mode or 'catch fork'
2191 to interfere with this. */
2193 /* This won't actually modify the breakpoint list, but will
2194 physically remove the breakpoints from the child. */
2195 detach_breakpoints (new_pid
);
2197 /* Retain child fork in ptrace (stopped) state. */
2198 if (!find_fork_pid (new_pid
))
2201 /* Report as spurious, so that infrun doesn't want to follow
2202 this fork. We're actually doing an infcall in
2204 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
2205 linux_enable_event_reporting (pid_to_ptid (new_pid
));
2207 /* Report the stop to the core. */
2211 if (event
== PTRACE_EVENT_FORK
)
2212 ourstatus
->kind
= TARGET_WAITKIND_FORKED
;
2213 else if (event
== PTRACE_EVENT_VFORK
)
2214 ourstatus
->kind
= TARGET_WAITKIND_VFORKED
;
2217 struct lwp_info
*new_lp
;
2219 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2221 if (debug_linux_nat
)
2222 fprintf_unfiltered (gdb_stdlog
,
2223 "LHEW: Got clone event "
2224 "from LWP %d, new child is LWP %ld\n",
2227 new_lp
= add_lwp (BUILD_LWP (new_pid
, GET_PID (lp
->ptid
)));
2229 new_lp
->stopped
= 1;
2231 if (WSTOPSIG (status
) != SIGSTOP
)
2233 /* This can happen if someone starts sending signals to
2234 the new thread before it gets a chance to run, which
2235 have a lower number than SIGSTOP (e.g. SIGUSR1).
2236 This is an unlikely case, and harder to handle for
2237 fork / vfork than for clone, so we do not try - but
2238 we handle it for clone events here. We'll send
2239 the other signal on to the thread below. */
2241 new_lp
->signalled
= 1;
2245 struct thread_info
*tp
;
2247 /* When we stop for an event in some other thread, and
2248 pull the thread list just as this thread has cloned,
2249 we'll have seen the new thread in the thread_db list
2250 before handling the CLONE event (glibc's
2251 pthread_create adds the new thread to the thread list
2252 before clone'ing, and has the kernel fill in the
2253 thread's tid on the clone call with
2254 CLONE_PARENT_SETTID). If that happened, and the core
2255 had requested the new thread to stop, we'll have
2256 killed it with SIGSTOP. But since SIGSTOP is not an
2257 RT signal, it can only be queued once. We need to be
2258 careful to not resume the LWP if we wanted it to
2259 stop. In that case, we'll leave the SIGSTOP pending.
2260 It will later be reported as TARGET_SIGNAL_0. */
2261 tp
= find_thread_ptid (new_lp
->ptid
);
2262 if (tp
!= NULL
&& tp
->stop_requested
)
2263 new_lp
->last_resume_kind
= resume_stop
;
2270 /* Add the new thread to GDB's lists as soon as possible
2273 1) the frontend doesn't have to wait for a stop to
2276 2) we tag it with the correct running state. */
2278 /* If the thread_db layer is active, let it know about
2279 this new thread, and add it to GDB's list. */
2280 if (!thread_db_attach_lwp (new_lp
->ptid
))
2282 /* We're not using thread_db. Add it to GDB's
2284 target_post_attach (GET_LWP (new_lp
->ptid
));
2285 add_thread (new_lp
->ptid
);
2290 set_running (new_lp
->ptid
, 1);
2291 set_executing (new_lp
->ptid
, 1);
2292 /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced
2294 new_lp
->last_resume_kind
= resume_continue
;
2300 /* We created NEW_LP so it cannot yet contain STATUS. */
2301 gdb_assert (new_lp
->status
== 0);
2303 /* Save the wait status to report later. */
2304 if (debug_linux_nat
)
2305 fprintf_unfiltered (gdb_stdlog
,
2306 "LHEW: waitpid of new LWP %ld, "
2307 "saving status %s\n",
2308 (long) GET_LWP (new_lp
->ptid
),
2309 status_to_str (status
));
2310 new_lp
->status
= status
;
2313 /* Note the need to use the low target ops to resume, to
2314 handle resuming with PT_SYSCALL if we have syscall
2318 new_lp
->resumed
= 1;
2322 gdb_assert (new_lp
->last_resume_kind
== resume_continue
);
2323 if (debug_linux_nat
)
2324 fprintf_unfiltered (gdb_stdlog
,
2325 "LHEW: resuming new LWP %ld\n",
2326 GET_LWP (new_lp
->ptid
));
2327 linux_ops
->to_resume (linux_ops
, pid_to_ptid (new_pid
),
2328 0, TARGET_SIGNAL_0
);
2329 new_lp
->stopped
= 0;
2333 if (debug_linux_nat
)
2334 fprintf_unfiltered (gdb_stdlog
,
2335 "LHEW: resuming parent LWP %d\n", pid
);
2336 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
2337 0, TARGET_SIGNAL_0
);
2345 if (event
== PTRACE_EVENT_EXEC
)
2347 if (debug_linux_nat
)
2348 fprintf_unfiltered (gdb_stdlog
,
2349 "LHEW: Got exec event from LWP %ld\n",
2350 GET_LWP (lp
->ptid
));
2352 ourstatus
->kind
= TARGET_WAITKIND_EXECD
;
2353 ourstatus
->value
.execd_pathname
2354 = xstrdup (linux_child_pid_to_exec_file (pid
));
2359 if (event
== PTRACE_EVENT_VFORK_DONE
)
2361 if (current_inferior ()->waiting_for_vfork_done
)
2363 if (debug_linux_nat
)
2364 fprintf_unfiltered (gdb_stdlog
,
2365 "LHEW: Got expected PTRACE_EVENT_"
2366 "VFORK_DONE from LWP %ld: stopping\n",
2367 GET_LWP (lp
->ptid
));
2369 ourstatus
->kind
= TARGET_WAITKIND_VFORK_DONE
;
2373 if (debug_linux_nat
)
2374 fprintf_unfiltered (gdb_stdlog
,
2375 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2376 "from LWP %ld: resuming\n",
2377 GET_LWP (lp
->ptid
));
2378 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2382 internal_error (__FILE__
, __LINE__
,
2383 _("unknown ptrace event %d"), event
);
2386 /* Return non-zero if LWP is a zombie. */
2389 linux_lwp_is_zombie (long lwp
)
2391 char buffer
[MAXPATHLEN
];
2396 xsnprintf (buffer
, sizeof (buffer
), "/proc/%ld/status", lwp
);
2397 procfile
= fopen (buffer
, "r");
2398 if (procfile
== NULL
)
2400 warning (_("unable to open /proc file '%s'"), buffer
);
2405 while (fgets (buffer
, sizeof (buffer
), procfile
) != NULL
)
2406 if (strncmp (buffer
, "State:", 6) == 0)
2411 retval
= (have_state
2412 && strcmp (buffer
, "State:\tZ (zombie)\n") == 0);
2417 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2421 wait_lwp (struct lwp_info
*lp
)
2425 int thread_dead
= 0;
2428 gdb_assert (!lp
->stopped
);
2429 gdb_assert (lp
->status
== 0);
2431 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2432 block_child_signals (&prev_mask
);
2436 /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind
2437 was right and we should just call sigsuspend. */
2439 pid
= my_waitpid (GET_LWP (lp
->ptid
), &status
, WNOHANG
);
2440 if (pid
== -1 && errno
== ECHILD
)
2441 pid
= my_waitpid (GET_LWP (lp
->ptid
), &status
, __WCLONE
| WNOHANG
);
2442 if (pid
== -1 && errno
== ECHILD
)
2444 /* The thread has previously exited. We need to delete it
2445 now because, for some vendor 2.4 kernels with NPTL
2446 support backported, there won't be an exit event unless
2447 it is the main thread. 2.6 kernels will report an exit
2448 event for each thread that exits, as expected. */
2450 if (debug_linux_nat
)
2451 fprintf_unfiltered (gdb_stdlog
, "WL: %s vanished.\n",
2452 target_pid_to_str (lp
->ptid
));
2457 /* Bugs 10970, 12702.
2458 Thread group leader may have exited in which case we'll lock up in
2459 waitpid if there are other threads, even if they are all zombies too.
2460 Basically, we're not supposed to use waitpid this way.
2461 __WCLONE is not applicable for the leader so we can't use that.
2462 LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED
2463 process; it gets ESRCH both for the zombie and for running processes.
2465 As a workaround, check if we're waiting for the thread group leader and
2466 if it's a zombie, and avoid calling waitpid if it is.
2468 This is racy, what if the tgl becomes a zombie right after we check?
2469 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2470 waiting waitpid but the linux_lwp_is_zombie is safe this way. */
2472 if (GET_PID (lp
->ptid
) == GET_LWP (lp
->ptid
)
2473 && linux_lwp_is_zombie (GET_LWP (lp
->ptid
)))
2476 if (debug_linux_nat
)
2477 fprintf_unfiltered (gdb_stdlog
,
2478 "WL: Thread group leader %s vanished.\n",
2479 target_pid_to_str (lp
->ptid
));
2483 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2484 get invoked despite our caller had them intentionally blocked by
2485 block_child_signals. This is sensitive only to the loop of
2486 linux_nat_wait_1 and there if we get called my_waitpid gets called
2487 again before it gets to sigsuspend so we can safely let the handlers
2488 get executed here. */
2490 sigsuspend (&suspend_mask
);
2493 restore_child_signals_mask (&prev_mask
);
2497 gdb_assert (pid
== GET_LWP (lp
->ptid
));
2499 if (debug_linux_nat
)
2501 fprintf_unfiltered (gdb_stdlog
,
2502 "WL: waitpid %s received %s\n",
2503 target_pid_to_str (lp
->ptid
),
2504 status_to_str (status
));
2507 /* Check if the thread has exited. */
2508 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2511 if (debug_linux_nat
)
2512 fprintf_unfiltered (gdb_stdlog
, "WL: %s exited.\n",
2513 target_pid_to_str (lp
->ptid
));
2523 gdb_assert (WIFSTOPPED (status
));
2525 /* Handle GNU/Linux's syscall SIGTRAPs. */
2526 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2528 /* No longer need the sysgood bit. The ptrace event ends up
2529 recorded in lp->waitstatus if we care for it. We can carry
2530 on handling the event like a regular SIGTRAP from here
2532 status
= W_STOPCODE (SIGTRAP
);
2533 if (linux_handle_syscall_trap (lp
, 1))
2534 return wait_lwp (lp
);
2537 /* Handle GNU/Linux's extended waitstatus for trace events. */
2538 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 != 0)
2540 if (debug_linux_nat
)
2541 fprintf_unfiltered (gdb_stdlog
,
2542 "WL: Handling extended status 0x%06x\n",
2544 if (linux_handle_extended_wait (lp
, status
, 1))
2545 return wait_lwp (lp
);
2551 /* Save the most recent siginfo for LP. This is currently only called
2552 for SIGTRAP; some ports use the si_addr field for
2553 target_stopped_data_address. In the future, it may also be used to
2554 restore the siginfo of requeued signals. */
2557 save_siginfo (struct lwp_info
*lp
)
2560 ptrace (PTRACE_GETSIGINFO
, GET_LWP (lp
->ptid
),
2561 (PTRACE_TYPE_ARG3
) 0, &lp
->siginfo
);
2564 memset (&lp
->siginfo
, 0, sizeof (lp
->siginfo
));
2567 /* Send a SIGSTOP to LP. */
2570 stop_callback (struct lwp_info
*lp
, void *data
)
2572 if (!lp
->stopped
&& !lp
->signalled
)
2576 if (debug_linux_nat
)
2578 fprintf_unfiltered (gdb_stdlog
,
2579 "SC: kill %s **<SIGSTOP>**\n",
2580 target_pid_to_str (lp
->ptid
));
2583 ret
= kill_lwp (GET_LWP (lp
->ptid
), SIGSTOP
);
2584 if (debug_linux_nat
)
2586 fprintf_unfiltered (gdb_stdlog
,
2587 "SC: lwp kill %d %s\n",
2589 errno
? safe_strerror (errno
) : "ERRNO-OK");
2593 gdb_assert (lp
->status
== 0);
2599 /* Return non-zero if LWP PID has a pending SIGINT. */
2602 linux_nat_has_pending_sigint (int pid
)
2604 sigset_t pending
, blocked
, ignored
;
2606 linux_proc_pending_signals (pid
, &pending
, &blocked
, &ignored
);
2608 if (sigismember (&pending
, SIGINT
)
2609 && !sigismember (&ignored
, SIGINT
))
2615 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2618 set_ignore_sigint (struct lwp_info
*lp
, void *data
)
2620 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2621 flag to consume the next one. */
2622 if (lp
->stopped
&& lp
->status
!= 0 && WIFSTOPPED (lp
->status
)
2623 && WSTOPSIG (lp
->status
) == SIGINT
)
2626 lp
->ignore_sigint
= 1;
2631 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2632 This function is called after we know the LWP has stopped; if the LWP
2633 stopped before the expected SIGINT was delivered, then it will never have
2634 arrived. Also, if the signal was delivered to a shared queue and consumed
2635 by a different thread, it will never be delivered to this LWP. */
2638 maybe_clear_ignore_sigint (struct lwp_info
*lp
)
2640 if (!lp
->ignore_sigint
)
2643 if (!linux_nat_has_pending_sigint (GET_LWP (lp
->ptid
)))
2645 if (debug_linux_nat
)
2646 fprintf_unfiltered (gdb_stdlog
,
2647 "MCIS: Clearing bogus flag for %s\n",
2648 target_pid_to_str (lp
->ptid
));
2649 lp
->ignore_sigint
= 0;
2653 /* Fetch the possible triggered data watchpoint info and store it in
2656 On some archs, like x86, that use debug registers to set
2657 watchpoints, it's possible that the way to know which watched
2658 address trapped, is to check the register that is used to select
2659 which address to watch. Problem is, between setting the watchpoint
2660 and reading back which data address trapped, the user may change
2661 the set of watchpoints, and, as a consequence, GDB changes the
2662 debug registers in the inferior. To avoid reading back a stale
2663 stopped-data-address when that happens, we cache in LP the fact
2664 that a watchpoint trapped, and the corresponding data address, as
2665 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2666 registers meanwhile, we have the cached data we can rely on. */
2669 save_sigtrap (struct lwp_info
*lp
)
2671 struct cleanup
*old_chain
;
2673 if (linux_ops
->to_stopped_by_watchpoint
== NULL
)
2675 lp
->stopped_by_watchpoint
= 0;
2679 old_chain
= save_inferior_ptid ();
2680 inferior_ptid
= lp
->ptid
;
2682 lp
->stopped_by_watchpoint
= linux_ops
->to_stopped_by_watchpoint ();
2684 if (lp
->stopped_by_watchpoint
)
2686 if (linux_ops
->to_stopped_data_address
!= NULL
)
2687 lp
->stopped_data_address_p
=
2688 linux_ops
->to_stopped_data_address (¤t_target
,
2689 &lp
->stopped_data_address
);
2691 lp
->stopped_data_address_p
= 0;
2694 do_cleanups (old_chain
);
2697 /* See save_sigtrap. */
2700 linux_nat_stopped_by_watchpoint (void)
2702 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2704 gdb_assert (lp
!= NULL
);
2706 return lp
->stopped_by_watchpoint
;
2710 linux_nat_stopped_data_address (struct target_ops
*ops
, CORE_ADDR
*addr_p
)
2712 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2714 gdb_assert (lp
!= NULL
);
2716 *addr_p
= lp
->stopped_data_address
;
2718 return lp
->stopped_data_address_p
;
2721 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2724 sigtrap_is_event (int status
)
2726 return WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
;
2729 /* SIGTRAP-like events recognizer. */
2731 static int (*linux_nat_status_is_event
) (int status
) = sigtrap_is_event
;
2733 /* Check for SIGTRAP-like events in LP. */
2736 linux_nat_lp_status_is_event (struct lwp_info
*lp
)
2738 /* We check for lp->waitstatus in addition to lp->status, because we can
2739 have pending process exits recorded in lp->status
2740 and W_EXITCODE(0,0) == 0. We should probably have an additional
2741 lp->status_p flag. */
2743 return (lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
2744 && linux_nat_status_is_event (lp
->status
));
2747 /* Set alternative SIGTRAP-like events recognizer. If
2748 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2752 linux_nat_set_status_is_event (struct target_ops
*t
,
2753 int (*status_is_event
) (int status
))
2755 linux_nat_status_is_event
= status_is_event
;
2758 /* Wait until LP is stopped. */
2761 stop_wait_callback (struct lwp_info
*lp
, void *data
)
2763 struct inferior
*inf
= find_inferior_pid (GET_PID (lp
->ptid
));
2765 /* If this is a vfork parent, bail out, it is not going to report
2766 any SIGSTOP until the vfork is done with. */
2767 if (inf
->vfork_child
!= NULL
)
2774 status
= wait_lwp (lp
);
2778 if (lp
->ignore_sigint
&& WIFSTOPPED (status
)
2779 && WSTOPSIG (status
) == SIGINT
)
2781 lp
->ignore_sigint
= 0;
2784 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2785 if (debug_linux_nat
)
2786 fprintf_unfiltered (gdb_stdlog
,
2787 "PTRACE_CONT %s, 0, 0 (%s) "
2788 "(discarding SIGINT)\n",
2789 target_pid_to_str (lp
->ptid
),
2790 errno
? safe_strerror (errno
) : "OK");
2792 return stop_wait_callback (lp
, NULL
);
2795 maybe_clear_ignore_sigint (lp
);
2797 if (WSTOPSIG (status
) != SIGSTOP
)
2799 if (linux_nat_status_is_event (status
))
2801 /* If a LWP other than the LWP that we're reporting an
2802 event for has hit a GDB breakpoint (as opposed to
2803 some random trap signal), then just arrange for it to
2804 hit it again later. We don't keep the SIGTRAP status
2805 and don't forward the SIGTRAP signal to the LWP. We
2806 will handle the current event, eventually we will
2807 resume all LWPs, and this one will get its breakpoint
2810 If we do not do this, then we run the risk that the
2811 user will delete or disable the breakpoint, but the
2812 thread will have already tripped on it. */
2814 /* Save the trap's siginfo in case we need it later. */
2819 /* Now resume this LWP and get the SIGSTOP event. */
2821 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2822 if (debug_linux_nat
)
2824 fprintf_unfiltered (gdb_stdlog
,
2825 "PTRACE_CONT %s, 0, 0 (%s)\n",
2826 target_pid_to_str (lp
->ptid
),
2827 errno
? safe_strerror (errno
) : "OK");
2829 fprintf_unfiltered (gdb_stdlog
,
2830 "SWC: Candidate SIGTRAP event in %s\n",
2831 target_pid_to_str (lp
->ptid
));
2833 /* Hold this event/waitstatus while we check to see if
2834 there are any more (we still want to get that SIGSTOP). */
2835 stop_wait_callback (lp
, NULL
);
2837 /* Hold the SIGTRAP for handling by linux_nat_wait. If
2838 there's another event, throw it back into the
2842 if (debug_linux_nat
)
2843 fprintf_unfiltered (gdb_stdlog
,
2844 "SWC: kill %s, %s\n",
2845 target_pid_to_str (lp
->ptid
),
2846 status_to_str ((int) status
));
2847 kill_lwp (GET_LWP (lp
->ptid
), WSTOPSIG (lp
->status
));
2850 /* Save the sigtrap event. */
2851 lp
->status
= status
;
2856 /* The thread was stopped with a signal other than
2857 SIGSTOP, and didn't accidentally trip a breakpoint. */
2859 if (debug_linux_nat
)
2861 fprintf_unfiltered (gdb_stdlog
,
2862 "SWC: Pending event %s in %s\n",
2863 status_to_str ((int) status
),
2864 target_pid_to_str (lp
->ptid
));
2866 /* Now resume this LWP and get the SIGSTOP event. */
2868 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2869 if (debug_linux_nat
)
2870 fprintf_unfiltered (gdb_stdlog
,
2871 "SWC: PTRACE_CONT %s, 0, 0 (%s)\n",
2872 target_pid_to_str (lp
->ptid
),
2873 errno
? safe_strerror (errno
) : "OK");
2875 /* Hold this event/waitstatus while we check to see if
2876 there are any more (we still want to get that SIGSTOP). */
2877 stop_wait_callback (lp
, NULL
);
2879 /* If the lp->status field is still empty, use it to
2880 hold this event. If not, then this event must be
2881 returned to the event queue of the LWP. */
2884 if (debug_linux_nat
)
2886 fprintf_unfiltered (gdb_stdlog
,
2887 "SWC: kill %s, %s\n",
2888 target_pid_to_str (lp
->ptid
),
2889 status_to_str ((int) status
));
2891 kill_lwp (GET_LWP (lp
->ptid
), WSTOPSIG (status
));
2894 lp
->status
= status
;
2900 /* We caught the SIGSTOP that we intended to catch, so
2901 there's no SIGSTOP pending. */
2910 /* Return non-zero if LP has a wait status pending. */
2913 status_callback (struct lwp_info
*lp
, void *data
)
2915 /* Only report a pending wait status if we pretend that this has
2916 indeed been resumed. */
2920 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
2922 /* A ptrace event, like PTRACE_FORK|VFORK|EXEC, syscall event,
2923 or a pending process exit. Note that `W_EXITCODE(0,0) ==
2924 0', so a clean process exit can not be stored pending in
2925 lp->status, it is indistinguishable from
2926 no-pending-status. */
2930 if (lp
->status
!= 0)
2936 /* Return non-zero if LP isn't stopped. */
2939 running_callback (struct lwp_info
*lp
, void *data
)
2941 return (!lp
->stopped
2942 || ((lp
->status
!= 0
2943 || lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
2947 /* Count the LWP's that have had events. */
2950 count_events_callback (struct lwp_info
*lp
, void *data
)
2954 gdb_assert (count
!= NULL
);
2956 /* Count only resumed LWPs that have a SIGTRAP event pending. */
2957 if (lp
->resumed
&& linux_nat_lp_status_is_event (lp
))
2963 /* Select the LWP (if any) that is currently being single-stepped. */
2966 select_singlestep_lwp_callback (struct lwp_info
*lp
, void *data
)
2968 if (lp
->last_resume_kind
== resume_step
2975 /* Select the Nth LWP that has had a SIGTRAP event. */
2978 select_event_lwp_callback (struct lwp_info
*lp
, void *data
)
2980 int *selector
= data
;
2982 gdb_assert (selector
!= NULL
);
2984 /* Select only resumed LWPs that have a SIGTRAP event pending. */
2985 if (lp
->resumed
&& linux_nat_lp_status_is_event (lp
))
2986 if ((*selector
)-- == 0)
2993 cancel_breakpoint (struct lwp_info
*lp
)
2995 /* Arrange for a breakpoint to be hit again later. We don't keep
2996 the SIGTRAP status and don't forward the SIGTRAP signal to the
2997 LWP. We will handle the current event, eventually we will resume
2998 this LWP, and this breakpoint will trap again.
3000 If we do not do this, then we run the risk that the user will
3001 delete or disable the breakpoint, but the LWP will have already
3004 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3005 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3008 pc
= regcache_read_pc (regcache
) - gdbarch_decr_pc_after_break (gdbarch
);
3009 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
3011 if (debug_linux_nat
)
3012 fprintf_unfiltered (gdb_stdlog
,
3013 "CB: Push back breakpoint for %s\n",
3014 target_pid_to_str (lp
->ptid
));
3016 /* Back up the PC if necessary. */
3017 if (gdbarch_decr_pc_after_break (gdbarch
))
3018 regcache_write_pc (regcache
, pc
);
3026 cancel_breakpoints_callback (struct lwp_info
*lp
, void *data
)
3028 struct lwp_info
*event_lp
= data
;
3030 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
3034 /* If a LWP other than the LWP that we're reporting an event for has
3035 hit a GDB breakpoint (as opposed to some random trap signal),
3036 then just arrange for it to hit it again later. We don't keep
3037 the SIGTRAP status and don't forward the SIGTRAP signal to the
3038 LWP. We will handle the current event, eventually we will resume
3039 all LWPs, and this one will get its breakpoint trap again.
3041 If we do not do this, then we run the risk that the user will
3042 delete or disable the breakpoint, but the LWP will have already
3045 if (linux_nat_lp_status_is_event (lp
)
3046 && cancel_breakpoint (lp
))
3047 /* Throw away the SIGTRAP. */
3053 /* Select one LWP out of those that have events pending. */
3056 select_event_lwp (ptid_t filter
, struct lwp_info
**orig_lp
, int *status
)
3059 int random_selector
;
3060 struct lwp_info
*event_lp
;
3062 /* Record the wait status for the original LWP. */
3063 (*orig_lp
)->status
= *status
;
3065 /* Give preference to any LWP that is being single-stepped. */
3066 event_lp
= iterate_over_lwps (filter
,
3067 select_singlestep_lwp_callback
, NULL
);
3068 if (event_lp
!= NULL
)
3070 if (debug_linux_nat
)
3071 fprintf_unfiltered (gdb_stdlog
,
3072 "SEL: Select single-step %s\n",
3073 target_pid_to_str (event_lp
->ptid
));
3077 /* No single-stepping LWP. Select one at random, out of those
3078 which have had SIGTRAP events. */
3080 /* First see how many SIGTRAP events we have. */
3081 iterate_over_lwps (filter
, count_events_callback
, &num_events
);
3083 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
3084 random_selector
= (int)
3085 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
3087 if (debug_linux_nat
&& num_events
> 1)
3088 fprintf_unfiltered (gdb_stdlog
,
3089 "SEL: Found %d SIGTRAP events, selecting #%d\n",
3090 num_events
, random_selector
);
3092 event_lp
= iterate_over_lwps (filter
,
3093 select_event_lwp_callback
,
3097 if (event_lp
!= NULL
)
3099 /* Switch the event LWP. */
3100 *orig_lp
= event_lp
;
3101 *status
= event_lp
->status
;
3104 /* Flush the wait status for the event LWP. */
3105 (*orig_lp
)->status
= 0;
3108 /* Return non-zero if LP has been resumed. */
3111 resumed_callback (struct lwp_info
*lp
, void *data
)
3116 /* Stop an active thread, verify it still exists, then resume it. If
3117 the thread ends up with a pending status, then it is not resumed,
3118 and *DATA (really a pointer to int), is set. */
3121 stop_and_resume_callback (struct lwp_info
*lp
, void *data
)
3123 int *new_pending_p
= data
;
3127 ptid_t ptid
= lp
->ptid
;
3129 stop_callback (lp
, NULL
);
3130 stop_wait_callback (lp
, NULL
);
3132 /* Resume if the lwp still exists, and the core wanted it
3134 lp
= find_lwp_pid (ptid
);
3137 if (lp
->last_resume_kind
== resume_stop
3140 /* The core wanted the LWP to stop. Even if it stopped
3141 cleanly (with SIGSTOP), leave the event pending. */
3142 if (debug_linux_nat
)
3143 fprintf_unfiltered (gdb_stdlog
,
3144 "SARC: core wanted LWP %ld stopped "
3145 "(leaving SIGSTOP pending)\n",
3146 GET_LWP (lp
->ptid
));
3147 lp
->status
= W_STOPCODE (SIGSTOP
);
3150 if (lp
->status
== 0)
3152 if (debug_linux_nat
)
3153 fprintf_unfiltered (gdb_stdlog
,
3154 "SARC: re-resuming LWP %ld\n",
3155 GET_LWP (lp
->ptid
));
3156 resume_lwp (lp
, lp
->step
);
3160 if (debug_linux_nat
)
3161 fprintf_unfiltered (gdb_stdlog
,
3162 "SARC: not re-resuming LWP %ld "
3164 GET_LWP (lp
->ptid
));
3173 /* Check if we should go on and pass this event to common code.
3174 Return the affected lwp if we are, or NULL otherwise. If we stop
3175 all lwps temporarily, we may end up with new pending events in some
3176 other lwp. In that case set *NEW_PENDING_P to true. */
3178 static struct lwp_info
*
3179 linux_nat_filter_event (int lwpid
, int status
, int *new_pending_p
)
3181 struct lwp_info
*lp
;
3185 lp
= find_lwp_pid (pid_to_ptid (lwpid
));
3187 /* Check for stop events reported by a process we didn't already
3188 know about - anything not already in our LWP list.
3190 If we're expecting to receive stopped processes after
3191 fork, vfork, and clone events, then we'll just add the
3192 new one to our list and go back to waiting for the event
3193 to be reported - the stopped process might be returned
3194 from waitpid before or after the event is.
3196 But note the case of a non-leader thread exec'ing after the
3197 leader having exited, and gone from our lists. The non-leader
3198 thread changes its tid to the tgid. */
3200 if (WIFSTOPPED (status
) && lp
== NULL
3201 && (WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 == PTRACE_EVENT_EXEC
))
3203 /* A multi-thread exec after we had seen the leader exiting. */
3204 if (debug_linux_nat
)
3205 fprintf_unfiltered (gdb_stdlog
,
3206 "LLW: Re-adding thread group leader LWP %d.\n",
3209 lp
= add_lwp (BUILD_LWP (lwpid
, lwpid
));
3212 add_thread (lp
->ptid
);
3215 if (WIFSTOPPED (status
) && !lp
)
3217 add_to_pid_list (&stopped_pids
, lwpid
, status
);
3221 /* Make sure we don't report an event for the exit of an LWP not in
3222 our list, i.e. not part of the current process. This can happen
3223 if we detach from a program we originally forked and then it
3225 if (!WIFSTOPPED (status
) && !lp
)
3228 /* Handle GNU/Linux's syscall SIGTRAPs. */
3229 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
3231 /* No longer need the sysgood bit. The ptrace event ends up
3232 recorded in lp->waitstatus if we care for it. We can carry
3233 on handling the event like a regular SIGTRAP from here
3235 status
= W_STOPCODE (SIGTRAP
);
3236 if (linux_handle_syscall_trap (lp
, 0))
3240 /* Handle GNU/Linux's extended waitstatus for trace events. */
3241 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 != 0)
3243 if (debug_linux_nat
)
3244 fprintf_unfiltered (gdb_stdlog
,
3245 "LLW: Handling extended status 0x%06x\n",
3247 if (linux_handle_extended_wait (lp
, status
, 0))
3251 if (linux_nat_status_is_event (status
))
3253 /* Save the trap's siginfo in case we need it later. */
3259 /* Check if the thread has exited. */
3260 if ((WIFEXITED (status
) || WIFSIGNALED (status
))
3261 && num_lwps (GET_PID (lp
->ptid
)) > 1)
3263 /* If this is the main thread, we must stop all threads and verify
3264 if they are still alive. This is because in the nptl thread model
3265 on Linux 2.4, there is no signal issued for exiting LWPs
3266 other than the main thread. We only get the main thread exit
3267 signal once all child threads have already exited. If we
3268 stop all the threads and use the stop_wait_callback to check
3269 if they have exited we can determine whether this signal
3270 should be ignored or whether it means the end of the debugged
3271 application, regardless of which threading model is being
3273 if (GET_PID (lp
->ptid
) == GET_LWP (lp
->ptid
))
3276 iterate_over_lwps (pid_to_ptid (GET_PID (lp
->ptid
)),
3277 stop_and_resume_callback
, new_pending_p
);
3280 if (debug_linux_nat
)
3281 fprintf_unfiltered (gdb_stdlog
,
3282 "LLW: %s exited.\n",
3283 target_pid_to_str (lp
->ptid
));
3285 if (num_lwps (GET_PID (lp
->ptid
)) > 1)
3287 /* If there is at least one more LWP, then the exit signal
3288 was not the end of the debugged application and should be
3295 /* Check if the current LWP has previously exited. In the nptl
3296 thread model, LWPs other than the main thread do not issue
3297 signals when they exit so we must check whenever the thread has
3298 stopped. A similar check is made in stop_wait_callback(). */
3299 if (num_lwps (GET_PID (lp
->ptid
)) > 1 && !linux_thread_alive (lp
->ptid
))
3301 ptid_t ptid
= pid_to_ptid (GET_PID (lp
->ptid
));
3303 if (debug_linux_nat
)
3304 fprintf_unfiltered (gdb_stdlog
,
3305 "LLW: %s exited.\n",
3306 target_pid_to_str (lp
->ptid
));
3310 /* Make sure there is at least one thread running. */
3311 gdb_assert (iterate_over_lwps (ptid
, running_callback
, NULL
));
3313 /* Discard the event. */
3317 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3318 an attempt to stop an LWP. */
3320 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGSTOP
)
3322 if (debug_linux_nat
)
3323 fprintf_unfiltered (gdb_stdlog
,
3324 "LLW: Delayed SIGSTOP caught for %s.\n",
3325 target_pid_to_str (lp
->ptid
));
3329 if (lp
->last_resume_kind
!= resume_stop
)
3331 /* This is a delayed SIGSTOP. */
3333 registers_changed ();
3335 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
3336 lp
->step
, TARGET_SIGNAL_0
);
3337 if (debug_linux_nat
)
3338 fprintf_unfiltered (gdb_stdlog
,
3339 "LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
3341 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3342 target_pid_to_str (lp
->ptid
));
3345 gdb_assert (lp
->resumed
);
3347 /* Discard the event. */
3352 /* Make sure we don't report a SIGINT that we have already displayed
3353 for another thread. */
3354 if (lp
->ignore_sigint
3355 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGINT
)
3357 if (debug_linux_nat
)
3358 fprintf_unfiltered (gdb_stdlog
,
3359 "LLW: Delayed SIGINT caught for %s.\n",
3360 target_pid_to_str (lp
->ptid
));
3362 /* This is a delayed SIGINT. */
3363 lp
->ignore_sigint
= 0;
3365 registers_changed ();
3366 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
3367 lp
->step
, TARGET_SIGNAL_0
);
3368 if (debug_linux_nat
)
3369 fprintf_unfiltered (gdb_stdlog
,
3370 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3372 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3373 target_pid_to_str (lp
->ptid
));
3376 gdb_assert (lp
->resumed
);
3378 /* Discard the event. */
3382 /* An interesting event. */
3384 lp
->status
= status
;
3388 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3389 their exits until all other threads in the group have exited. */
3392 check_zombie_leaders (void)
3394 struct inferior
*inf
;
3398 struct lwp_info
*leader_lp
;
3403 leader_lp
= find_lwp_pid (pid_to_ptid (inf
->pid
));
3404 if (leader_lp
!= NULL
3405 /* Check if there are other threads in the group, as we may
3406 have raced with the inferior simply exiting. */
3407 && num_lwps (inf
->pid
) > 1
3408 && linux_lwp_is_zombie (inf
->pid
))
3410 if (debug_linux_nat
)
3411 fprintf_unfiltered (gdb_stdlog
,
3412 "CZL: Thread group leader %d zombie "
3413 "(it exited, or another thread execd).\n",
3416 /* A leader zombie can mean one of two things:
3418 - It exited, and there's an exit status pending
3419 available, or only the leader exited (not the whole
3420 program). In the latter case, we can't waitpid the
3421 leader's exit status until all other threads are gone.
3423 - There are 3 or more threads in the group, and a thread
3424 other than the leader exec'd. On an exec, the Linux
3425 kernel destroys all other threads (except the execing
3426 one) in the thread group, and resets the execing thread's
3427 tid to the tgid. No exit notification is sent for the
3428 execing thread -- from the ptracer's perspective, it
3429 appears as though the execing thread just vanishes.
3430 Until we reap all other threads except the leader and the
3431 execing thread, the leader will be zombie, and the
3432 execing thread will be in `D (disc sleep)'. As soon as
3433 all other threads are reaped, the execing thread changes
3434 it's tid to the tgid, and the previous (zombie) leader
3435 vanishes, giving place to the "new" leader. We could try
3436 distinguishing the exit and exec cases, by waiting once
3437 more, and seeing if something comes out, but it doesn't
3438 sound useful. The previous leader _does_ go away, and
3439 we'll re-add the new one once we see the exec event
3440 (which is just the same as what would happen if the
3441 previous leader did exit voluntarily before some other
3444 if (debug_linux_nat
)
3445 fprintf_unfiltered (gdb_stdlog
,
3446 "CZL: Thread group leader %d vanished.\n",
3448 exit_lwp (leader_lp
);
3454 linux_nat_wait_1 (struct target_ops
*ops
,
3455 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3458 static sigset_t prev_mask
;
3459 enum resume_kind last_resume_kind
;
3460 struct lwp_info
*lp
;
3463 if (debug_linux_nat
)
3464 fprintf_unfiltered (gdb_stdlog
, "LLW: enter\n");
3466 /* The first time we get here after starting a new inferior, we may
3467 not have added it to the LWP list yet - this is the earliest
3468 moment at which we know its PID. */
3469 if (ptid_is_pid (inferior_ptid
))
3471 /* Upgrade the main thread's ptid. */
3472 thread_change_ptid (inferior_ptid
,
3473 BUILD_LWP (GET_PID (inferior_ptid
),
3474 GET_PID (inferior_ptid
)));
3476 lp
= add_lwp (inferior_ptid
);
3480 /* Make sure SIGCHLD is blocked. */
3481 block_child_signals (&prev_mask
);
3487 /* First check if there is a LWP with a wait status pending. */
3488 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3490 /* Any LWP in the PTID group that's been resumed will do. */
3491 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3494 if (debug_linux_nat
&& lp
->status
)
3495 fprintf_unfiltered (gdb_stdlog
,
3496 "LLW: Using pending wait status %s for %s.\n",
3497 status_to_str (lp
->status
),
3498 target_pid_to_str (lp
->ptid
));
3501 else if (is_lwp (ptid
))
3503 if (debug_linux_nat
)
3504 fprintf_unfiltered (gdb_stdlog
,
3505 "LLW: Waiting for specific LWP %s.\n",
3506 target_pid_to_str (ptid
));
3508 /* We have a specific LWP to check. */
3509 lp
= find_lwp_pid (ptid
);
3512 if (debug_linux_nat
&& lp
->status
)
3513 fprintf_unfiltered (gdb_stdlog
,
3514 "LLW: Using pending wait status %s for %s.\n",
3515 status_to_str (lp
->status
),
3516 target_pid_to_str (lp
->ptid
));
3518 /* We check for lp->waitstatus in addition to lp->status,
3519 because we can have pending process exits recorded in
3520 lp->status and W_EXITCODE(0,0) == 0. We should probably have
3521 an additional lp->status_p flag. */
3522 if (lp
->status
== 0 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
3526 if (lp
&& lp
->signalled
&& lp
->last_resume_kind
!= resume_stop
)
3528 /* A pending SIGSTOP may interfere with the normal stream of
3529 events. In a typical case where interference is a problem,
3530 we have a SIGSTOP signal pending for LWP A while
3531 single-stepping it, encounter an event in LWP B, and take the
3532 pending SIGSTOP while trying to stop LWP A. After processing
3533 the event in LWP B, LWP A is continued, and we'll never see
3534 the SIGTRAP associated with the last time we were
3535 single-stepping LWP A. */
3537 /* Resume the thread. It should halt immediately returning the
3539 registers_changed ();
3540 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
3541 lp
->step
, TARGET_SIGNAL_0
);
3542 if (debug_linux_nat
)
3543 fprintf_unfiltered (gdb_stdlog
,
3544 "LLW: %s %s, 0, 0 (expect SIGSTOP)\n",
3545 lp
->step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3546 target_pid_to_str (lp
->ptid
));
3548 gdb_assert (lp
->resumed
);
3550 /* Catch the pending SIGSTOP. */
3551 status
= lp
->status
;
3554 stop_wait_callback (lp
, NULL
);
3556 /* If the lp->status field isn't empty, we caught another signal
3557 while flushing the SIGSTOP. Return it back to the event
3558 queue of the LWP, as we already have an event to handle. */
3561 if (debug_linux_nat
)
3562 fprintf_unfiltered (gdb_stdlog
,
3563 "LLW: kill %s, %s\n",
3564 target_pid_to_str (lp
->ptid
),
3565 status_to_str (lp
->status
));
3566 kill_lwp (GET_LWP (lp
->ptid
), WSTOPSIG (lp
->status
));
3569 lp
->status
= status
;
3572 if (!target_can_async_p ())
3574 /* Causes SIGINT to be passed on to the attached process. */
3578 /* But if we don't find a pending event, we'll have to wait. */
3584 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3587 - If the thread group leader exits while other threads in the
3588 thread group still exist, waitpid(TGID, ...) hangs. That
3589 waitpid won't return an exit status until the other threads
3590 in the group are reapped.
3592 - When a non-leader thread execs, that thread just vanishes
3593 without reporting an exit (so we'd hang if we waited for it
3594 explicitly in that case). The exec event is reported to
3598 lwpid
= my_waitpid (-1, &status
, __WCLONE
| WNOHANG
);
3599 if (lwpid
== 0 || (lwpid
== -1 && errno
== ECHILD
))
3600 lwpid
= my_waitpid (-1, &status
, WNOHANG
);
3602 if (debug_linux_nat
)
3603 fprintf_unfiltered (gdb_stdlog
,
3604 "LNW: waitpid(-1, ...) returned %d, %s\n",
3605 lwpid
, errno
? safe_strerror (errno
) : "ERRNO-OK");
3609 /* If this is true, then we paused LWPs momentarily, and may
3610 now have pending events to handle. */
3613 if (debug_linux_nat
)
3615 fprintf_unfiltered (gdb_stdlog
,
3616 "LLW: waitpid %ld received %s\n",
3617 (long) lwpid
, status_to_str (status
));
3620 lp
= linux_nat_filter_event (lwpid
, status
, &new_pending
);
3622 /* STATUS is now no longer valid, use LP->STATUS instead. */
3625 if (lp
&& !ptid_match (lp
->ptid
, ptid
))
3627 gdb_assert (lp
->resumed
);
3629 if (debug_linux_nat
)
3631 "LWP %ld got an event %06x, leaving pending.\n",
3632 ptid_get_lwp (lp
->ptid
), lp
->status
);
3634 if (WIFSTOPPED (lp
->status
))
3636 if (WSTOPSIG (lp
->status
) != SIGSTOP
)
3638 /* Cancel breakpoint hits. The breakpoint may
3639 be removed before we fetch events from this
3640 process to report to the core. It is best
3641 not to assume the moribund breakpoints
3642 heuristic always handles these cases --- it
3643 could be too many events go through to the
3644 core before this one is handled. All-stop
3645 always cancels breakpoint hits in all
3648 && linux_nat_lp_status_is_event (lp
)
3649 && cancel_breakpoint (lp
))
3651 /* Throw away the SIGTRAP. */
3654 if (debug_linux_nat
)
3656 "LLW: LWP %ld hit a breakpoint while"
3657 " waiting for another process;"
3659 ptid_get_lwp (lp
->ptid
));
3669 else if (WIFEXITED (lp
->status
) || WIFSIGNALED (lp
->status
))
3671 if (debug_linux_nat
)
3673 "Process %ld exited while stopping LWPs\n",
3674 ptid_get_lwp (lp
->ptid
));
3676 /* This was the last lwp in the process. Since
3677 events are serialized to GDB core, and we can't
3678 report this one right now, but GDB core and the
3679 other target layers will want to be notified
3680 about the exit code/signal, leave the status
3681 pending for the next time we're able to report
3684 /* Prevent trying to stop this thread again. We'll
3685 never try to resume it because it has a pending
3689 /* Dead LWP's aren't expected to reported a pending
3693 /* Store the pending event in the waitstatus as
3694 well, because W_EXITCODE(0,0) == 0. */
3695 store_waitstatus (&lp
->waitstatus
, lp
->status
);
3704 /* Some LWP now has a pending event. Go all the way
3705 back to check it. */
3711 /* We got an event to report to the core. */
3715 /* Retry until nothing comes out of waitpid. A single
3716 SIGCHLD can indicate more than one child stopped. */
3720 /* Check for zombie thread group leaders. Those can't be reaped
3721 until all other threads in the thread group are. */
3722 check_zombie_leaders ();
3724 /* If there are no resumed children left, bail. We'd be stuck
3725 forever in the sigsuspend call below otherwise. */
3726 if (iterate_over_lwps (ptid
, resumed_callback
, NULL
) == NULL
)
3728 if (debug_linux_nat
)
3729 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (no resumed LWP)\n");
3731 ourstatus
->kind
= TARGET_WAITKIND_NO_RESUMED
;
3733 if (!target_can_async_p ())
3734 clear_sigint_trap ();
3736 restore_child_signals_mask (&prev_mask
);
3737 return minus_one_ptid
;
3740 /* No interesting event to report to the core. */
3742 if (target_options
& TARGET_WNOHANG
)
3744 if (debug_linux_nat
)
3745 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (ignore)\n");
3747 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3748 restore_child_signals_mask (&prev_mask
);
3749 return minus_one_ptid
;
3752 /* We shouldn't end up here unless we want to try again. */
3753 gdb_assert (lp
== NULL
);
3755 /* Block until we get an event reported with SIGCHLD. */
3756 sigsuspend (&suspend_mask
);
3759 if (!target_can_async_p ())
3760 clear_sigint_trap ();
3764 status
= lp
->status
;
3767 /* Don't report signals that GDB isn't interested in, such as
3768 signals that are neither printed nor stopped upon. Stopping all
3769 threads can be a bit time-consuming so if we want decent
3770 performance with heavily multi-threaded programs, especially when
3771 they're using a high frequency timer, we'd better avoid it if we
3774 if (WIFSTOPPED (status
))
3776 enum target_signal signo
= target_signal_from_host (WSTOPSIG (status
));
3778 /* When using hardware single-step, we need to report every signal.
3779 Otherwise, signals in pass_mask may be short-circuited. */
3781 && WSTOPSIG (status
) && sigismember (&pass_mask
, WSTOPSIG (status
)))
3783 /* FIMXE: kettenis/2001-06-06: Should we resume all threads
3784 here? It is not clear we should. GDB may not expect
3785 other threads to run. On the other hand, not resuming
3786 newly attached threads may cause an unwanted delay in
3787 getting them running. */
3788 registers_changed ();
3789 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
3791 if (debug_linux_nat
)
3792 fprintf_unfiltered (gdb_stdlog
,
3793 "LLW: %s %s, %s (preempt 'handle')\n",
3795 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3796 target_pid_to_str (lp
->ptid
),
3797 (signo
!= TARGET_SIGNAL_0
3798 ? strsignal (target_signal_to_host (signo
))
3806 /* Only do the below in all-stop, as we currently use SIGINT
3807 to implement target_stop (see linux_nat_stop) in
3809 if (signo
== TARGET_SIGNAL_INT
&& signal_pass_state (signo
) == 0)
3811 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3812 forwarded to the entire process group, that is, all LWPs
3813 will receive it - unless they're using CLONE_THREAD to
3814 share signals. Since we only want to report it once, we
3815 mark it as ignored for all LWPs except this one. */
3816 iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid
)),
3817 set_ignore_sigint
, NULL
);
3818 lp
->ignore_sigint
= 0;
3821 maybe_clear_ignore_sigint (lp
);
3825 /* This LWP is stopped now. */
3828 if (debug_linux_nat
)
3829 fprintf_unfiltered (gdb_stdlog
, "LLW: Candidate event %s in %s.\n",
3830 status_to_str (status
), target_pid_to_str (lp
->ptid
));
3834 /* Now stop all other LWP's ... */
3835 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
3837 /* ... and wait until all of them have reported back that
3838 they're no longer running. */
3839 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
3841 /* If we're not waiting for a specific LWP, choose an event LWP
3842 from among those that have had events. Giving equal priority
3843 to all LWPs that have had events helps prevent
3845 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3846 select_event_lwp (ptid
, &lp
, &status
);
3848 /* Now that we've selected our final event LWP, cancel any
3849 breakpoints in other LWPs that have hit a GDB breakpoint.
3850 See the comment in cancel_breakpoints_callback to find out
3852 iterate_over_lwps (minus_one_ptid
, cancel_breakpoints_callback
, lp
);
3854 /* We'll need this to determine whether to report a SIGSTOP as
3855 TARGET_WAITKIND_0. Need to take a copy because
3856 resume_clear_callback clears it. */
3857 last_resume_kind
= lp
->last_resume_kind
;
3859 /* In all-stop, from the core's perspective, all LWPs are now
3860 stopped until a new resume action is sent over. */
3861 iterate_over_lwps (minus_one_ptid
, resume_clear_callback
, NULL
);
3866 last_resume_kind
= lp
->last_resume_kind
;
3867 resume_clear_callback (lp
, NULL
);
3870 if (linux_nat_status_is_event (status
))
3872 if (debug_linux_nat
)
3873 fprintf_unfiltered (gdb_stdlog
,
3874 "LLW: trap ptid is %s.\n",
3875 target_pid_to_str (lp
->ptid
));
3878 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3880 *ourstatus
= lp
->waitstatus
;
3881 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3884 store_waitstatus (ourstatus
, status
);
3886 if (debug_linux_nat
)
3887 fprintf_unfiltered (gdb_stdlog
, "LLW: exit\n");
3889 restore_child_signals_mask (&prev_mask
);
3891 if (last_resume_kind
== resume_stop
3892 && ourstatus
->kind
== TARGET_WAITKIND_STOPPED
3893 && WSTOPSIG (status
) == SIGSTOP
)
3895 /* A thread that has been requested to stop by GDB with
3896 target_stop, and it stopped cleanly, so report as SIG0. The
3897 use of SIGSTOP is an implementation detail. */
3898 ourstatus
->value
.sig
= TARGET_SIGNAL_0
;
3901 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
3902 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
3905 lp
->core
= linux_nat_core_of_thread_1 (lp
->ptid
);
3910 /* Resume LWPs that are currently stopped without any pending status
3911 to report, but are resumed from the core's perspective. */
3914 resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
)
3916 ptid_t
*wait_ptid_p
= data
;
3921 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
3923 gdb_assert (is_executing (lp
->ptid
));
3925 /* Don't bother if there's a breakpoint at PC that we'd hit
3926 immediately, and we're not waiting for this LWP. */
3927 if (!ptid_match (lp
->ptid
, *wait_ptid_p
))
3929 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3930 CORE_ADDR pc
= regcache_read_pc (regcache
);
3932 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
3936 if (debug_linux_nat
)
3937 fprintf_unfiltered (gdb_stdlog
,
3938 "RSRL: resuming stopped-resumed LWP %s\n",
3939 target_pid_to_str (lp
->ptid
));
3941 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
3942 lp
->step
, TARGET_SIGNAL_0
);
3944 memset (&lp
->siginfo
, 0, sizeof (lp
->siginfo
));
3945 lp
->stopped_by_watchpoint
= 0;
3952 linux_nat_wait (struct target_ops
*ops
,
3953 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3958 if (debug_linux_nat
)
3959 fprintf_unfiltered (gdb_stdlog
,
3960 "linux_nat_wait: [%s]\n", target_pid_to_str (ptid
));
3962 /* Flush the async file first. */
3963 if (target_can_async_p ())
3964 async_file_flush ();
3966 /* Resume LWPs that are currently stopped without any pending status
3967 to report, but are resumed from the core's perspective. LWPs get
3968 in this state if we find them stopping at a time we're not
3969 interested in reporting the event (target_wait on a
3970 specific_process, for example, see linux_nat_wait_1), and
3971 meanwhile the event became uninteresting. Don't bother resuming
3972 LWPs we're not going to wait for if they'd stop immediately. */
3974 iterate_over_lwps (minus_one_ptid
, resume_stopped_resumed_lwps
, &ptid
);
3976 event_ptid
= linux_nat_wait_1 (ops
, ptid
, ourstatus
, target_options
);
3978 /* If we requested any event, and something came out, assume there
3979 may be more. If we requested a specific lwp or process, also
3980 assume there may be more. */
3981 if (target_can_async_p ()
3982 && (ourstatus
->kind
!= TARGET_WAITKIND_IGNORE
3983 || !ptid_equal (ptid
, minus_one_ptid
)))
3986 /* Get ready for the next event. */
3987 if (target_can_async_p ())
3988 target_async (inferior_event_handler
, 0);
3994 kill_callback (struct lwp_info
*lp
, void *data
)
3996 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3999 kill (GET_LWP (lp
->ptid
), SIGKILL
);
4000 if (debug_linux_nat
)
4001 fprintf_unfiltered (gdb_stdlog
,
4002 "KC: kill (SIGKILL) %s, 0, 0 (%s)\n",
4003 target_pid_to_str (lp
->ptid
),
4004 errno
? safe_strerror (errno
) : "OK");
4006 /* Some kernels ignore even SIGKILL for processes under ptrace. */
4009 ptrace (PTRACE_KILL
, GET_LWP (lp
->ptid
), 0, 0);
4010 if (debug_linux_nat
)
4011 fprintf_unfiltered (gdb_stdlog
,
4012 "KC: PTRACE_KILL %s, 0, 0 (%s)\n",
4013 target_pid_to_str (lp
->ptid
),
4014 errno
? safe_strerror (errno
) : "OK");
4020 kill_wait_callback (struct lwp_info
*lp
, void *data
)
4024 /* We must make sure that there are no pending events (delayed
4025 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
4026 program doesn't interfere with any following debugging session. */
4028 /* For cloned processes we must check both with __WCLONE and
4029 without, since the exit status of a cloned process isn't reported
4035 pid
= my_waitpid (GET_LWP (lp
->ptid
), NULL
, __WCLONE
);
4036 if (pid
!= (pid_t
) -1)
4038 if (debug_linux_nat
)
4039 fprintf_unfiltered (gdb_stdlog
,
4040 "KWC: wait %s received unknown.\n",
4041 target_pid_to_str (lp
->ptid
));
4042 /* The Linux kernel sometimes fails to kill a thread
4043 completely after PTRACE_KILL; that goes from the stop
4044 point in do_fork out to the one in
4045 get_signal_to_deliever and waits again. So kill it
4047 kill_callback (lp
, NULL
);
4050 while (pid
== GET_LWP (lp
->ptid
));
4052 gdb_assert (pid
== -1 && errno
== ECHILD
);
4057 pid
= my_waitpid (GET_LWP (lp
->ptid
), NULL
, 0);
4058 if (pid
!= (pid_t
) -1)
4060 if (debug_linux_nat
)
4061 fprintf_unfiltered (gdb_stdlog
,
4062 "KWC: wait %s received unk.\n",
4063 target_pid_to_str (lp
->ptid
));
4064 /* See the call to kill_callback above. */
4065 kill_callback (lp
, NULL
);
4068 while (pid
== GET_LWP (lp
->ptid
));
4070 gdb_assert (pid
== -1 && errno
== ECHILD
);
4075 linux_nat_kill (struct target_ops
*ops
)
4077 struct target_waitstatus last
;
4081 /* If we're stopped while forking and we haven't followed yet,
4082 kill the other task. We need to do this first because the
4083 parent will be sleeping if this is a vfork. */
4085 get_last_target_status (&last_ptid
, &last
);
4087 if (last
.kind
== TARGET_WAITKIND_FORKED
4088 || last
.kind
== TARGET_WAITKIND_VFORKED
)
4090 ptrace (PT_KILL
, PIDGET (last
.value
.related_pid
), 0, 0);
4094 if (forks_exist_p ())
4095 linux_fork_killall ();
4098 ptid_t ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
4100 /* Stop all threads before killing them, since ptrace requires
4101 that the thread is stopped to sucessfully PTRACE_KILL. */
4102 iterate_over_lwps (ptid
, stop_callback
, NULL
);
4103 /* ... and wait until all of them have reported back that
4104 they're no longer running. */
4105 iterate_over_lwps (ptid
, stop_wait_callback
, NULL
);
4107 /* Kill all LWP's ... */
4108 iterate_over_lwps (ptid
, kill_callback
, NULL
);
4110 /* ... and wait until we've flushed all events. */
4111 iterate_over_lwps (ptid
, kill_wait_callback
, NULL
);
4114 target_mourn_inferior ();
4118 linux_nat_mourn_inferior (struct target_ops
*ops
)
4120 purge_lwp_list (ptid_get_pid (inferior_ptid
));
4122 if (! forks_exist_p ())
4123 /* Normal case, no other forks available. */
4124 linux_ops
->to_mourn_inferior (ops
);
4126 /* Multi-fork case. The current inferior_ptid has exited, but
4127 there are other viable forks to debug. Delete the exiting
4128 one and context-switch to the first available. */
4129 linux_fork_mourn_inferior ();
4132 /* Convert a native/host siginfo object, into/from the siginfo in the
4133 layout of the inferiors' architecture. */
4136 siginfo_fixup (struct siginfo
*siginfo
, gdb_byte
*inf_siginfo
, int direction
)
4140 if (linux_nat_siginfo_fixup
!= NULL
)
4141 done
= linux_nat_siginfo_fixup (siginfo
, inf_siginfo
, direction
);
4143 /* If there was no callback, or the callback didn't do anything,
4144 then just do a straight memcpy. */
4148 memcpy (siginfo
, inf_siginfo
, sizeof (struct siginfo
));
4150 memcpy (inf_siginfo
, siginfo
, sizeof (struct siginfo
));
4155 linux_xfer_siginfo (struct target_ops
*ops
, enum target_object object
,
4156 const char *annex
, gdb_byte
*readbuf
,
4157 const gdb_byte
*writebuf
, ULONGEST offset
, LONGEST len
)
4160 struct siginfo siginfo
;
4161 gdb_byte inf_siginfo
[sizeof (struct siginfo
)];
4163 gdb_assert (object
== TARGET_OBJECT_SIGNAL_INFO
);
4164 gdb_assert (readbuf
|| writebuf
);
4166 pid
= GET_LWP (inferior_ptid
);
4168 pid
= GET_PID (inferior_ptid
);
4170 if (offset
> sizeof (siginfo
))
4174 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
4178 /* When GDB is built as a 64-bit application, ptrace writes into
4179 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
4180 inferior with a 64-bit GDB should look the same as debugging it
4181 with a 32-bit GDB, we need to convert it. GDB core always sees
4182 the converted layout, so any read/write will have to be done
4184 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
4186 if (offset
+ len
> sizeof (siginfo
))
4187 len
= sizeof (siginfo
) - offset
;
4189 if (readbuf
!= NULL
)
4190 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
4193 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
4195 /* Convert back to ptrace layout before flushing it out. */
4196 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
4199 ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
4208 linux_nat_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4209 const char *annex
, gdb_byte
*readbuf
,
4210 const gdb_byte
*writebuf
,
4211 ULONGEST offset
, LONGEST len
)
4213 struct cleanup
*old_chain
;
4216 if (object
== TARGET_OBJECT_SIGNAL_INFO
)
4217 return linux_xfer_siginfo (ops
, object
, annex
, readbuf
, writebuf
,
4220 /* The target is connected but no live inferior is selected. Pass
4221 this request down to a lower stratum (e.g., the executable
4223 if (object
== TARGET_OBJECT_MEMORY
&& ptid_equal (inferior_ptid
, null_ptid
))
4226 old_chain
= save_inferior_ptid ();
4228 if (is_lwp (inferior_ptid
))
4229 inferior_ptid
= pid_to_ptid (GET_LWP (inferior_ptid
));
4231 xfer
= linux_ops
->to_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4234 do_cleanups (old_chain
);
4239 linux_thread_alive (ptid_t ptid
)
4243 gdb_assert (is_lwp (ptid
));
4245 /* Send signal 0 instead of anything ptrace, because ptracing a
4246 running thread errors out claiming that the thread doesn't
4248 err
= kill_lwp (GET_LWP (ptid
), 0);
4250 if (debug_linux_nat
)
4251 fprintf_unfiltered (gdb_stdlog
,
4252 "LLTA: KILL(SIG0) %s (%s)\n",
4253 target_pid_to_str (ptid
),
4254 err
? safe_strerror (tmp_errno
) : "OK");
4263 linux_nat_thread_alive (struct target_ops
*ops
, ptid_t ptid
)
4265 return linux_thread_alive (ptid
);
4269 linux_nat_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
4271 static char buf
[64];
4274 && (GET_PID (ptid
) != GET_LWP (ptid
)
4275 || num_lwps (GET_PID (ptid
)) > 1))
4277 snprintf (buf
, sizeof (buf
), "LWP %ld", GET_LWP (ptid
));
4281 return normal_pid_to_str (ptid
);
4285 linux_nat_thread_name (struct thread_info
*thr
)
4287 int pid
= ptid_get_pid (thr
->ptid
);
4288 long lwp
= ptid_get_lwp (thr
->ptid
);
4289 #define FORMAT "/proc/%d/task/%ld/comm"
4290 char buf
[sizeof (FORMAT
) + 30];
4292 char *result
= NULL
;
4294 snprintf (buf
, sizeof (buf
), FORMAT
, pid
, lwp
);
4295 comm_file
= fopen (buf
, "r");
4298 /* Not exported by the kernel, so we define it here. */
4300 static char line
[COMM_LEN
+ 1];
4302 if (fgets (line
, sizeof (line
), comm_file
))
4304 char *nl
= strchr (line
, '\n');
4321 /* Accepts an integer PID; Returns a string representing a file that
4322 can be opened to get the symbols for the child process. */
4325 linux_child_pid_to_exec_file (int pid
)
4327 char *name1
, *name2
;
4329 name1
= xmalloc (MAXPATHLEN
);
4330 name2
= xmalloc (MAXPATHLEN
);
4331 make_cleanup (xfree
, name1
);
4332 make_cleanup (xfree
, name2
);
4333 memset (name2
, 0, MAXPATHLEN
);
4335 sprintf (name1
, "/proc/%d/exe", pid
);
4336 if (readlink (name1
, name2
, MAXPATHLEN
) > 0)
4342 /* Service function for corefiles and info proc. */
4345 read_mapping (FILE *mapfile
,
4350 char *device
, long long *inode
, char *filename
)
4352 int ret
= fscanf (mapfile
, "%llx-%llx %s %llx %s %llx",
4353 addr
, endaddr
, permissions
, offset
, device
, inode
);
4356 if (ret
> 0 && ret
!= EOF
)
4358 /* Eat everything up to EOL for the filename. This will prevent
4359 weird filenames (such as one with embedded whitespace) from
4360 confusing this code. It also makes this code more robust in
4361 respect to annotations the kernel may add after the filename.
4363 Note the filename is used for informational purposes
4365 ret
+= fscanf (mapfile
, "%[^\n]\n", filename
);
4368 return (ret
!= 0 && ret
!= EOF
);
4371 /* Fills the "to_find_memory_regions" target vector. Lists the memory
4372 regions in the inferior for a corefile. */
4375 linux_nat_find_memory_regions (find_memory_region_ftype func
, void *obfd
)
4377 int pid
= PIDGET (inferior_ptid
);
4378 char mapsfilename
[MAXPATHLEN
];
4380 long long addr
, endaddr
, size
, offset
, inode
;
4381 char permissions
[8], device
[8], filename
[MAXPATHLEN
];
4382 int read
, write
, exec
;
4383 struct cleanup
*cleanup
;
4385 /* Compose the filename for the /proc memory map, and open it. */
4386 sprintf (mapsfilename
, "/proc/%d/maps", pid
);
4387 if ((mapsfile
= fopen (mapsfilename
, "r")) == NULL
)
4388 error (_("Could not open %s."), mapsfilename
);
4389 cleanup
= make_cleanup_fclose (mapsfile
);
4392 fprintf_filtered (gdb_stdout
,
4393 "Reading memory regions from %s\n", mapsfilename
);
4395 /* Now iterate until end-of-file. */
4396 while (read_mapping (mapsfile
, &addr
, &endaddr
, &permissions
[0],
4397 &offset
, &device
[0], &inode
, &filename
[0]))
4399 size
= endaddr
- addr
;
4401 /* Get the segment's permissions. */
4402 read
= (strchr (permissions
, 'r') != 0);
4403 write
= (strchr (permissions
, 'w') != 0);
4404 exec
= (strchr (permissions
, 'x') != 0);
4408 fprintf_filtered (gdb_stdout
,
4409 "Save segment, %s bytes at %s (%c%c%c)",
4410 plongest (size
), paddress (target_gdbarch
, addr
),
4412 write
? 'w' : ' ', exec
? 'x' : ' ');
4414 fprintf_filtered (gdb_stdout
, " for %s", filename
);
4415 fprintf_filtered (gdb_stdout
, "\n");
4418 /* Invoke the callback function to create the corefile
4420 func (addr
, size
, read
, write
, exec
, obfd
);
4422 do_cleanups (cleanup
);
4427 find_signalled_thread (struct thread_info
*info
, void *data
)
4429 if (info
->suspend
.stop_signal
!= TARGET_SIGNAL_0
4430 && ptid_get_pid (info
->ptid
) == ptid_get_pid (inferior_ptid
))
4436 static enum target_signal
4437 find_stop_signal (void)
4439 struct thread_info
*info
=
4440 iterate_over_threads (find_signalled_thread
, NULL
);
4443 return info
->suspend
.stop_signal
;
4445 return TARGET_SIGNAL_0
;
4448 /* Records the thread's register state for the corefile note
4452 linux_nat_do_thread_registers (bfd
*obfd
, ptid_t ptid
,
4453 char *note_data
, int *note_size
,
4454 enum target_signal stop_signal
)
4456 unsigned long lwp
= ptid_get_lwp (ptid
);
4457 struct gdbarch
*gdbarch
= target_gdbarch
;
4458 struct regcache
*regcache
= get_thread_arch_regcache (ptid
, gdbarch
);
4459 const struct regset
*regset
;
4461 struct cleanup
*old_chain
;
4462 struct core_regset_section
*sect_list
;
4465 old_chain
= save_inferior_ptid ();
4466 inferior_ptid
= ptid
;
4467 target_fetch_registers (regcache
, -1);
4468 do_cleanups (old_chain
);
4470 core_regset_p
= gdbarch_regset_from_core_section_p (gdbarch
);
4471 sect_list
= gdbarch_core_regset_sections (gdbarch
);
4473 /* The loop below uses the new struct core_regset_section, which stores
4474 the supported section names and sizes for the core file. Note that
4475 note PRSTATUS needs to be treated specially. But the other notes are
4476 structurally the same, so they can benefit from the new struct. */
4477 if (core_regset_p
&& sect_list
!= NULL
)
4478 while (sect_list
->sect_name
!= NULL
)
4480 regset
= gdbarch_regset_from_core_section (gdbarch
,
4481 sect_list
->sect_name
,
4483 gdb_assert (regset
&& regset
->collect_regset
);
4484 gdb_regset
= xmalloc (sect_list
->size
);
4485 regset
->collect_regset (regset
, regcache
, -1,
4486 gdb_regset
, sect_list
->size
);
4488 if (strcmp (sect_list
->sect_name
, ".reg") == 0)
4489 note_data
= (char *) elfcore_write_prstatus
4490 (obfd
, note_data
, note_size
,
4491 lwp
, target_signal_to_host (stop_signal
),
4494 note_data
= (char *) elfcore_write_register_note
4495 (obfd
, note_data
, note_size
,
4496 sect_list
->sect_name
, gdb_regset
,
4502 /* For architectures that does not have the struct core_regset_section
4503 implemented, we use the old method. When all the architectures have
4504 the new support, the code below should be deleted. */
4507 gdb_gregset_t gregs
;
4508 gdb_fpregset_t fpregs
;
4511 && (regset
= gdbarch_regset_from_core_section (gdbarch
, ".reg",
4513 != NULL
&& regset
->collect_regset
!= NULL
)
4514 regset
->collect_regset (regset
, regcache
, -1,
4515 &gregs
, sizeof (gregs
));
4517 fill_gregset (regcache
, &gregs
, -1);
4519 note_data
= (char *) elfcore_write_prstatus
4520 (obfd
, note_data
, note_size
, lwp
, target_signal_to_host (stop_signal
),
4524 && (regset
= gdbarch_regset_from_core_section (gdbarch
, ".reg2",
4526 != NULL
&& regset
->collect_regset
!= NULL
)
4527 regset
->collect_regset (regset
, regcache
, -1,
4528 &fpregs
, sizeof (fpregs
));
4530 fill_fpregset (regcache
, &fpregs
, -1);
4532 note_data
= (char *) elfcore_write_prfpreg (obfd
,
4535 &fpregs
, sizeof (fpregs
));
4541 struct linux_nat_corefile_thread_data
4547 enum target_signal stop_signal
;
4550 /* Called by gdbthread.c once per thread. Records the thread's
4551 register state for the corefile note section. */
4554 linux_nat_corefile_thread_callback (struct lwp_info
*ti
, void *data
)
4556 struct linux_nat_corefile_thread_data
*args
= data
;
4558 args
->note_data
= linux_nat_do_thread_registers (args
->obfd
,
4568 /* Enumerate spufs IDs for process PID. */
4571 iterate_over_spus (int pid
, void (*callback
) (void *, int), void *data
)
4575 struct dirent
*entry
;
4577 xsnprintf (path
, sizeof path
, "/proc/%d/fd", pid
);
4578 dir
= opendir (path
);
4583 while ((entry
= readdir (dir
)) != NULL
)
4589 fd
= atoi (entry
->d_name
);
4593 xsnprintf (path
, sizeof path
, "/proc/%d/fd/%d", pid
, fd
);
4594 if (stat (path
, &st
) != 0)
4596 if (!S_ISDIR (st
.st_mode
))
4599 if (statfs (path
, &stfs
) != 0)
4601 if (stfs
.f_type
!= SPUFS_MAGIC
)
4604 callback (data
, fd
);
4610 /* Generate corefile notes for SPU contexts. */
4612 struct linux_spu_corefile_data
4620 linux_spu_corefile_callback (void *data
, int fd
)
4622 struct linux_spu_corefile_data
*args
= data
;
4625 static const char *spu_files
[] =
4647 for (i
= 0; i
< sizeof (spu_files
) / sizeof (spu_files
[0]); i
++)
4649 char annex
[32], note_name
[32];
4653 xsnprintf (annex
, sizeof annex
, "%d/%s", fd
, spu_files
[i
]);
4654 spu_len
= target_read_alloc (¤t_target
, TARGET_OBJECT_SPU
,
4658 xsnprintf (note_name
, sizeof note_name
, "SPU/%s", annex
);
4659 args
->note_data
= elfcore_write_note (args
->obfd
, args
->note_data
,
4660 args
->note_size
, note_name
,
4661 NT_SPU
, spu_data
, spu_len
);
4668 linux_spu_make_corefile_notes (bfd
*obfd
, char *note_data
, int *note_size
)
4670 struct linux_spu_corefile_data args
;
4673 args
.note_data
= note_data
;
4674 args
.note_size
= note_size
;
4676 iterate_over_spus (PIDGET (inferior_ptid
),
4677 linux_spu_corefile_callback
, &args
);
4679 return args
.note_data
;
4682 /* Fills the "to_make_corefile_note" target vector. Builds the note
4683 section for a corefile, and returns it in a malloc buffer. */
4686 linux_nat_make_corefile_notes (bfd
*obfd
, int *note_size
)
4688 struct linux_nat_corefile_thread_data thread_args
;
4689 /* The variable size must be >= sizeof (prpsinfo_t.pr_fname). */
4690 char fname
[16] = { '\0' };
4691 /* The variable size must be >= sizeof (prpsinfo_t.pr_psargs). */
4692 char psargs
[80] = { '\0' };
4693 char *note_data
= NULL
;
4694 ptid_t filter
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
4698 if (get_exec_file (0))
4700 strncpy (fname
, lbasename (get_exec_file (0)), sizeof (fname
));
4701 strncpy (psargs
, get_exec_file (0), sizeof (psargs
));
4702 if (get_inferior_args ())
4705 char *psargs_end
= psargs
+ sizeof (psargs
);
4707 /* linux_elfcore_write_prpsinfo () handles zero unterminated
4709 string_end
= memchr (psargs
, 0, sizeof (psargs
));
4710 if (string_end
!= NULL
)
4712 *string_end
++ = ' ';
4713 strncpy (string_end
, get_inferior_args (),
4714 psargs_end
- string_end
);
4717 note_data
= (char *) elfcore_write_prpsinfo (obfd
,
4719 note_size
, fname
, psargs
);
4722 /* Dump information for threads. */
4723 thread_args
.obfd
= obfd
;
4724 thread_args
.note_data
= note_data
;
4725 thread_args
.note_size
= note_size
;
4726 thread_args
.num_notes
= 0;
4727 thread_args
.stop_signal
= find_stop_signal ();
4728 iterate_over_lwps (filter
, linux_nat_corefile_thread_callback
, &thread_args
);
4729 gdb_assert (thread_args
.num_notes
!= 0);
4730 note_data
= thread_args
.note_data
;
4732 auxv_len
= target_read_alloc (¤t_target
, TARGET_OBJECT_AUXV
,
4736 note_data
= elfcore_write_note (obfd
, note_data
, note_size
,
4737 "CORE", NT_AUXV
, auxv
, auxv_len
);
4741 note_data
= linux_spu_make_corefile_notes (obfd
, note_data
, note_size
);
4743 make_cleanup (xfree
, note_data
);
4747 /* Implement the "info proc" command. */
4750 linux_nat_info_proc_cmd (char *args
, int from_tty
)
4752 /* A long is used for pid instead of an int to avoid a loss of precision
4753 compiler warning from the output of strtoul. */
4754 long pid
= PIDGET (inferior_ptid
);
4757 char buffer
[MAXPATHLEN
];
4758 char fname1
[MAXPATHLEN
], fname2
[MAXPATHLEN
];
4770 /* Break up 'args' into an argv array. */
4771 argv
= gdb_buildargv (args
);
4772 make_cleanup_freeargv (argv
);
4774 while (argv
!= NULL
&& *argv
!= NULL
)
4776 if (isdigit (argv
[0][0]))
4778 pid
= strtoul (argv
[0], NULL
, 10);
4780 else if (strncmp (argv
[0], "mappings", strlen (argv
[0])) == 0)
4784 else if (strcmp (argv
[0], "status") == 0)
4788 else if (strcmp (argv
[0], "stat") == 0)
4792 else if (strcmp (argv
[0], "cmd") == 0)
4796 else if (strncmp (argv
[0], "exe", strlen (argv
[0])) == 0)
4800 else if (strcmp (argv
[0], "cwd") == 0)
4804 else if (strncmp (argv
[0], "all", strlen (argv
[0])) == 0)
4810 /* [...] (future options here). */
4815 error (_("No current process: you must name one."));
4817 sprintf (fname1
, "/proc/%ld", pid
);
4818 if (stat (fname1
, &dummy
) != 0)
4819 error (_("No /proc directory: '%s'"), fname1
);
4821 printf_filtered (_("process %ld\n"), pid
);
4822 if (cmdline_f
|| all
)
4824 sprintf (fname1
, "/proc/%ld/cmdline", pid
);
4825 if ((procfile
= fopen (fname1
, "r")) != NULL
)
4827 struct cleanup
*cleanup
= make_cleanup_fclose (procfile
);
4829 if (fgets (buffer
, sizeof (buffer
), procfile
))
4830 printf_filtered ("cmdline = '%s'\n", buffer
);
4832 warning (_("unable to read '%s'"), fname1
);
4833 do_cleanups (cleanup
);
4836 warning (_("unable to open /proc file '%s'"), fname1
);
4840 sprintf (fname1
, "/proc/%ld/cwd", pid
);
4841 memset (fname2
, 0, sizeof (fname2
));
4842 if (readlink (fname1
, fname2
, sizeof (fname2
)) > 0)
4843 printf_filtered ("cwd = '%s'\n", fname2
);
4845 warning (_("unable to read link '%s'"), fname1
);
4849 sprintf (fname1
, "/proc/%ld/exe", pid
);
4850 memset (fname2
, 0, sizeof (fname2
));
4851 if (readlink (fname1
, fname2
, sizeof (fname2
)) > 0)
4852 printf_filtered ("exe = '%s'\n", fname2
);
4854 warning (_("unable to read link '%s'"), fname1
);
4856 if (mappings_f
|| all
)
4858 sprintf (fname1
, "/proc/%ld/maps", pid
);
4859 if ((procfile
= fopen (fname1
, "r")) != NULL
)
4861 long long addr
, endaddr
, size
, offset
, inode
;
4862 char permissions
[8], device
[8], filename
[MAXPATHLEN
];
4863 struct cleanup
*cleanup
;
4865 cleanup
= make_cleanup_fclose (procfile
);
4866 printf_filtered (_("Mapped address spaces:\n\n"));
4867 if (gdbarch_addr_bit (target_gdbarch
) == 32)
4869 printf_filtered ("\t%10s %10s %10s %10s %7s\n",
4872 " Size", " Offset", "objfile");
4876 printf_filtered (" %18s %18s %10s %10s %7s\n",
4879 " Size", " Offset", "objfile");
4882 while (read_mapping (procfile
, &addr
, &endaddr
, &permissions
[0],
4883 &offset
, &device
[0], &inode
, &filename
[0]))
4885 size
= endaddr
- addr
;
4887 /* FIXME: carlton/2003-08-27: Maybe the printf_filtered
4888 calls here (and possibly above) should be abstracted
4889 out into their own functions? Andrew suggests using
4890 a generic local_address_string instead to print out
4891 the addresses; that makes sense to me, too. */
4893 if (gdbarch_addr_bit (target_gdbarch
) == 32)
4895 printf_filtered ("\t%#10lx %#10lx %#10x %#10x %7s\n",
4896 (unsigned long) addr
, /* FIXME: pr_addr */
4897 (unsigned long) endaddr
,
4899 (unsigned int) offset
,
4900 filename
[0] ? filename
: "");
4904 printf_filtered (" %#18lx %#18lx %#10x %#10x %7s\n",
4905 (unsigned long) addr
, /* FIXME: pr_addr */
4906 (unsigned long) endaddr
,
4908 (unsigned int) offset
,
4909 filename
[0] ? filename
: "");
4913 do_cleanups (cleanup
);
4916 warning (_("unable to open /proc file '%s'"), fname1
);
4918 if (status_f
|| all
)
4920 sprintf (fname1
, "/proc/%ld/status", pid
);
4921 if ((procfile
= fopen (fname1
, "r")) != NULL
)
4923 struct cleanup
*cleanup
= make_cleanup_fclose (procfile
);
4925 while (fgets (buffer
, sizeof (buffer
), procfile
) != NULL
)
4926 puts_filtered (buffer
);
4927 do_cleanups (cleanup
);
4930 warning (_("unable to open /proc file '%s'"), fname1
);
4934 sprintf (fname1
, "/proc/%ld/stat", pid
);
4935 if ((procfile
= fopen (fname1
, "r")) != NULL
)
4940 struct cleanup
*cleanup
= make_cleanup_fclose (procfile
);
4942 if (fscanf (procfile
, "%d ", &itmp
) > 0)
4943 printf_filtered (_("Process: %d\n"), itmp
);
4944 if (fscanf (procfile
, "(%[^)]) ", &buffer
[0]) > 0)
4945 printf_filtered (_("Exec file: %s\n"), buffer
);
4946 if (fscanf (procfile
, "%c ", &ctmp
) > 0)
4947 printf_filtered (_("State: %c\n"), ctmp
);
4948 if (fscanf (procfile
, "%d ", &itmp
) > 0)
4949 printf_filtered (_("Parent process: %d\n"), itmp
);
4950 if (fscanf (procfile
, "%d ", &itmp
) > 0)
4951 printf_filtered (_("Process group: %d\n"), itmp
);
4952 if (fscanf (procfile
, "%d ", &itmp
) > 0)
4953 printf_filtered (_("Session id: %d\n"), itmp
);
4954 if (fscanf (procfile
, "%d ", &itmp
) > 0)
4955 printf_filtered (_("TTY: %d\n"), itmp
);
4956 if (fscanf (procfile
, "%d ", &itmp
) > 0)
4957 printf_filtered (_("TTY owner process group: %d\n"), itmp
);
4958 if (fscanf (procfile
, "%lu ", <mp
) > 0)
4959 printf_filtered (_("Flags: 0x%lx\n"), ltmp
);
4960 if (fscanf (procfile
, "%lu ", <mp
) > 0)
4961 printf_filtered (_("Minor faults (no memory page): %lu\n"),
4962 (unsigned long) ltmp
);
4963 if (fscanf (procfile
, "%lu ", <mp
) > 0)
4964 printf_filtered (_("Minor faults, children: %lu\n"),
4965 (unsigned long) ltmp
);
4966 if (fscanf (procfile
, "%lu ", <mp
) > 0)
4967 printf_filtered (_("Major faults (memory page faults): %lu\n"),
4968 (unsigned long) ltmp
);
4969 if (fscanf (procfile
, "%lu ", <mp
) > 0)
4970 printf_filtered (_("Major faults, children: %lu\n"),
4971 (unsigned long) ltmp
);
4972 if (fscanf (procfile
, "%ld ", <mp
) > 0)
4973 printf_filtered (_("utime: %ld\n"), ltmp
);
4974 if (fscanf (procfile
, "%ld ", <mp
) > 0)
4975 printf_filtered (_("stime: %ld\n"), ltmp
);
4976 if (fscanf (procfile
, "%ld ", <mp
) > 0)
4977 printf_filtered (_("utime, children: %ld\n"), ltmp
);
4978 if (fscanf (procfile
, "%ld ", <mp
) > 0)
4979 printf_filtered (_("stime, children: %ld\n"), ltmp
);
4980 if (fscanf (procfile
, "%ld ", <mp
) > 0)
4981 printf_filtered (_("jiffies remaining in current "
4982 "time slice: %ld\n"), ltmp
);
4983 if (fscanf (procfile
, "%ld ", <mp
) > 0)
4984 printf_filtered (_("'nice' value: %ld\n"), ltmp
);
4985 if (fscanf (procfile
, "%lu ", <mp
) > 0)
4986 printf_filtered (_("jiffies until next timeout: %lu\n"),
4987 (unsigned long) ltmp
);
4988 if (fscanf (procfile
, "%lu ", <mp
) > 0)
4989 printf_filtered (_("jiffies until next SIGALRM: %lu\n"),
4990 (unsigned long) ltmp
);
4991 if (fscanf (procfile
, "%ld ", <mp
) > 0)
4992 printf_filtered (_("start time (jiffies since "
4993 "system boot): %ld\n"), ltmp
);
4994 if (fscanf (procfile
, "%lu ", <mp
) > 0)
4995 printf_filtered (_("Virtual memory size: %lu\n"),
4996 (unsigned long) ltmp
);
4997 if (fscanf (procfile
, "%lu ", <mp
) > 0)
4998 printf_filtered (_("Resident set size: %lu\n"),
4999 (unsigned long) ltmp
);
5000 if (fscanf (procfile
, "%lu ", <mp
) > 0)
5001 printf_filtered (_("rlim: %lu\n"), (unsigned long) ltmp
);
5002 if (fscanf (procfile
, "%lu ", <mp
) > 0)
5003 printf_filtered (_("Start of text: 0x%lx\n"), ltmp
);
5004 if (fscanf (procfile
, "%lu ", <mp
) > 0)
5005 printf_filtered (_("End of text: 0x%lx\n"), ltmp
);
5006 if (fscanf (procfile
, "%lu ", <mp
) > 0)
5007 printf_filtered (_("Start of stack: 0x%lx\n"), ltmp
);
5008 #if 0 /* Don't know how architecture-dependent the rest is...
5009 Anyway the signal bitmap info is available from "status". */
5010 if (fscanf (procfile
, "%lu ", <mp
) > 0) /* FIXME arch? */
5011 printf_filtered (_("Kernel stack pointer: 0x%lx\n"), ltmp
);
5012 if (fscanf (procfile
, "%lu ", <mp
) > 0) /* FIXME arch? */
5013 printf_filtered (_("Kernel instr pointer: 0x%lx\n"), ltmp
);
5014 if (fscanf (procfile
, "%ld ", <mp
) > 0)
5015 printf_filtered (_("Pending signals bitmap: 0x%lx\n"), ltmp
);
5016 if (fscanf (procfile
, "%ld ", <mp
) > 0)
5017 printf_filtered (_("Blocked signals bitmap: 0x%lx\n"), ltmp
);
5018 if (fscanf (procfile
, "%ld ", <mp
) > 0)
5019 printf_filtered (_("Ignored signals bitmap: 0x%lx\n"), ltmp
);
5020 if (fscanf (procfile
, "%ld ", <mp
) > 0)
5021 printf_filtered (_("Catched signals bitmap: 0x%lx\n"), ltmp
);
5022 if (fscanf (procfile
, "%lu ", <mp
) > 0) /* FIXME arch? */
5023 printf_filtered (_("wchan (system call): 0x%lx\n"), ltmp
);
5025 do_cleanups (cleanup
);
5028 warning (_("unable to open /proc file '%s'"), fname1
);
5032 /* Implement the to_xfer_partial interface for memory reads using the /proc
5033 filesystem. Because we can use a single read() call for /proc, this
5034 can be much more efficient than banging away at PTRACE_PEEKTEXT,
5035 but it doesn't support writes. */
5038 linux_proc_xfer_partial (struct target_ops
*ops
, enum target_object object
,
5039 const char *annex
, gdb_byte
*readbuf
,
5040 const gdb_byte
*writebuf
,
5041 ULONGEST offset
, LONGEST len
)
5047 if (object
!= TARGET_OBJECT_MEMORY
|| !readbuf
)
5050 /* Don't bother for one word. */
5051 if (len
< 3 * sizeof (long))
5054 /* We could keep this file open and cache it - possibly one per
5055 thread. That requires some juggling, but is even faster. */
5056 sprintf (filename
, "/proc/%d/mem", PIDGET (inferior_ptid
));
5057 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
5061 /* If pread64 is available, use it. It's faster if the kernel
5062 supports it (only one syscall), and it's 64-bit safe even on
5063 32-bit platforms (for instance, SPARC debugging a SPARC64
5066 if (pread64 (fd
, readbuf
, len
, offset
) != len
)
5068 if (lseek (fd
, offset
, SEEK_SET
) == -1 || read (fd
, readbuf
, len
) != len
)
5079 /* Enumerate spufs IDs for process PID. */
5081 spu_enumerate_spu_ids (int pid
, gdb_byte
*buf
, ULONGEST offset
, LONGEST len
)
5083 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch
);
5085 LONGEST written
= 0;
5088 struct dirent
*entry
;
5090 xsnprintf (path
, sizeof path
, "/proc/%d/fd", pid
);
5091 dir
= opendir (path
);
5096 while ((entry
= readdir (dir
)) != NULL
)
5102 fd
= atoi (entry
->d_name
);
5106 xsnprintf (path
, sizeof path
, "/proc/%d/fd/%d", pid
, fd
);
5107 if (stat (path
, &st
) != 0)
5109 if (!S_ISDIR (st
.st_mode
))
5112 if (statfs (path
, &stfs
) != 0)
5114 if (stfs
.f_type
!= SPUFS_MAGIC
)
5117 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
5119 store_unsigned_integer (buf
+ pos
- offset
, 4, byte_order
, fd
);
5129 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
5130 object type, using the /proc file system. */
5132 linux_proc_xfer_spu (struct target_ops
*ops
, enum target_object object
,
5133 const char *annex
, gdb_byte
*readbuf
,
5134 const gdb_byte
*writebuf
,
5135 ULONGEST offset
, LONGEST len
)
5140 int pid
= PIDGET (inferior_ptid
);
5147 return spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
5150 xsnprintf (buf
, sizeof buf
, "/proc/%d/fd/%s", pid
, annex
);
5151 fd
= open (buf
, writebuf
? O_WRONLY
: O_RDONLY
);
5156 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
5163 ret
= write (fd
, writebuf
, (size_t) len
);
5165 ret
= read (fd
, readbuf
, (size_t) len
);
5172 /* Parse LINE as a signal set and add its set bits to SIGS. */
5175 add_line_to_sigset (const char *line
, sigset_t
*sigs
)
5177 int len
= strlen (line
) - 1;
5181 if (line
[len
] != '\n')
5182 error (_("Could not parse signal set: %s"), line
);
5190 if (*p
>= '0' && *p
<= '9')
5192 else if (*p
>= 'a' && *p
<= 'f')
5193 digit
= *p
- 'a' + 10;
5195 error (_("Could not parse signal set: %s"), line
);
5200 sigaddset (sigs
, signum
+ 1);
5202 sigaddset (sigs
, signum
+ 2);
5204 sigaddset (sigs
, signum
+ 3);
5206 sigaddset (sigs
, signum
+ 4);
5212 /* Find process PID's pending signals from /proc/pid/status and set
5216 linux_proc_pending_signals (int pid
, sigset_t
*pending
,
5217 sigset_t
*blocked
, sigset_t
*ignored
)
5220 char buffer
[MAXPATHLEN
], fname
[MAXPATHLEN
];
5221 struct cleanup
*cleanup
;
5223 sigemptyset (pending
);
5224 sigemptyset (blocked
);
5225 sigemptyset (ignored
);
5226 sprintf (fname
, "/proc/%d/status", pid
);
5227 procfile
= fopen (fname
, "r");
5228 if (procfile
== NULL
)
5229 error (_("Could not open %s"), fname
);
5230 cleanup
= make_cleanup_fclose (procfile
);
5232 while (fgets (buffer
, MAXPATHLEN
, procfile
) != NULL
)
5234 /* Normal queued signals are on the SigPnd line in the status
5235 file. However, 2.6 kernels also have a "shared" pending
5236 queue for delivering signals to a thread group, so check for
5239 Unfortunately some Red Hat kernels include the shared pending
5240 queue but not the ShdPnd status field. */
5242 if (strncmp (buffer
, "SigPnd:\t", 8) == 0)
5243 add_line_to_sigset (buffer
+ 8, pending
);
5244 else if (strncmp (buffer
, "ShdPnd:\t", 8) == 0)
5245 add_line_to_sigset (buffer
+ 8, pending
);
5246 else if (strncmp (buffer
, "SigBlk:\t", 8) == 0)
5247 add_line_to_sigset (buffer
+ 8, blocked
);
5248 else if (strncmp (buffer
, "SigIgn:\t", 8) == 0)
5249 add_line_to_sigset (buffer
+ 8, ignored
);
5252 do_cleanups (cleanup
);
5256 linux_nat_xfer_osdata (struct target_ops
*ops
, enum target_object object
,
5257 const char *annex
, gdb_byte
*readbuf
,
5258 const gdb_byte
*writebuf
, ULONGEST offset
, LONGEST len
)
5260 gdb_assert (object
== TARGET_OBJECT_OSDATA
);
5262 return linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
5266 linux_xfer_partial (struct target_ops
*ops
, enum target_object object
,
5267 const char *annex
, gdb_byte
*readbuf
,
5268 const gdb_byte
*writebuf
, ULONGEST offset
, LONGEST len
)
5272 if (object
== TARGET_OBJECT_AUXV
)
5273 return memory_xfer_auxv (ops
, object
, annex
, readbuf
, writebuf
,
5276 if (object
== TARGET_OBJECT_OSDATA
)
5277 return linux_nat_xfer_osdata (ops
, object
, annex
, readbuf
, writebuf
,
5280 if (object
== TARGET_OBJECT_SPU
)
5281 return linux_proc_xfer_spu (ops
, object
, annex
, readbuf
, writebuf
,
5284 /* GDB calculates all the addresses in possibly larget width of the address.
5285 Address width needs to be masked before its final use - either by
5286 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
5288 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
5290 if (object
== TARGET_OBJECT_MEMORY
)
5292 int addr_bit
= gdbarch_addr_bit (target_gdbarch
);
5294 if (addr_bit
< (sizeof (ULONGEST
) * HOST_CHAR_BIT
))
5295 offset
&= ((ULONGEST
) 1 << addr_bit
) - 1;
5298 xfer
= linux_proc_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
5303 return super_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
5307 /* Create a prototype generic GNU/Linux target. The client can override
5308 it with local methods. */
5311 linux_target_install_ops (struct target_ops
*t
)
5313 t
->to_insert_fork_catchpoint
= linux_child_insert_fork_catchpoint
;
5314 t
->to_remove_fork_catchpoint
= linux_child_remove_fork_catchpoint
;
5315 t
->to_insert_vfork_catchpoint
= linux_child_insert_vfork_catchpoint
;
5316 t
->to_remove_vfork_catchpoint
= linux_child_remove_vfork_catchpoint
;
5317 t
->to_insert_exec_catchpoint
= linux_child_insert_exec_catchpoint
;
5318 t
->to_remove_exec_catchpoint
= linux_child_remove_exec_catchpoint
;
5319 t
->to_set_syscall_catchpoint
= linux_child_set_syscall_catchpoint
;
5320 t
->to_pid_to_exec_file
= linux_child_pid_to_exec_file
;
5321 t
->to_post_startup_inferior
= linux_child_post_startup_inferior
;
5322 t
->to_post_attach
= linux_child_post_attach
;
5323 t
->to_follow_fork
= linux_child_follow_fork
;
5324 t
->to_find_memory_regions
= linux_nat_find_memory_regions
;
5325 t
->to_make_corefile_notes
= linux_nat_make_corefile_notes
;
5327 super_xfer_partial
= t
->to_xfer_partial
;
5328 t
->to_xfer_partial
= linux_xfer_partial
;
5334 struct target_ops
*t
;
5336 t
= inf_ptrace_target ();
5337 linux_target_install_ops (t
);
5343 linux_trad_target (CORE_ADDR (*register_u_offset
)(struct gdbarch
*, int, int))
5345 struct target_ops
*t
;
5347 t
= inf_ptrace_trad_target (register_u_offset
);
5348 linux_target_install_ops (t
);
5353 /* target_is_async_p implementation. */
5356 linux_nat_is_async_p (void)
5358 /* NOTE: palves 2008-03-21: We're only async when the user requests
5359 it explicitly with the "set target-async" command.
5360 Someday, linux will always be async. */
5361 return target_async_permitted
;
5364 /* target_can_async_p implementation. */
5367 linux_nat_can_async_p (void)
5369 /* NOTE: palves 2008-03-21: We're only async when the user requests
5370 it explicitly with the "set target-async" command.
5371 Someday, linux will always be async. */
5372 return target_async_permitted
;
5376 linux_nat_supports_non_stop (void)
5381 /* True if we want to support multi-process. To be removed when GDB
5382 supports multi-exec. */
5384 int linux_multi_process
= 1;
5387 linux_nat_supports_multi_process (void)
5389 return linux_multi_process
;
5393 linux_nat_supports_disable_randomization (void)
5395 #ifdef HAVE_PERSONALITY
5402 static int async_terminal_is_ours
= 1;
5404 /* target_terminal_inferior implementation. */
5407 linux_nat_terminal_inferior (void)
5409 if (!target_is_async_p ())
5411 /* Async mode is disabled. */
5412 terminal_inferior ();
5416 terminal_inferior ();
5418 /* Calls to target_terminal_*() are meant to be idempotent. */
5419 if (!async_terminal_is_ours
)
5422 delete_file_handler (input_fd
);
5423 async_terminal_is_ours
= 0;
5427 /* target_terminal_ours implementation. */
5430 linux_nat_terminal_ours (void)
5432 if (!target_is_async_p ())
5434 /* Async mode is disabled. */
5439 /* GDB should never give the terminal to the inferior if the
5440 inferior is running in the background (run&, continue&, etc.),
5441 but claiming it sure should. */
5444 if (async_terminal_is_ours
)
5447 clear_sigint_trap ();
5448 add_file_handler (input_fd
, stdin_event_handler
, 0);
5449 async_terminal_is_ours
= 1;
5452 static void (*async_client_callback
) (enum inferior_event_type event_type
,
5454 static void *async_client_context
;
5456 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
5457 so we notice when any child changes state, and notify the
5458 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
5459 above to wait for the arrival of a SIGCHLD. */
5462 sigchld_handler (int signo
)
5464 int old_errno
= errno
;
5466 if (debug_linux_nat
)
5467 ui_file_write_async_safe (gdb_stdlog
,
5468 "sigchld\n", sizeof ("sigchld\n") - 1);
5470 if (signo
== SIGCHLD
5471 && linux_nat_event_pipe
[0] != -1)
5472 async_file_mark (); /* Let the event loop know that there are
5473 events to handle. */
5478 /* Callback registered with the target events file descriptor. */
5481 handle_target_event (int error
, gdb_client_data client_data
)
5483 (*async_client_callback
) (INF_REG_EVENT
, async_client_context
);
5486 /* Create/destroy the target events pipe. Returns previous state. */
5489 linux_async_pipe (int enable
)
5491 int previous
= (linux_nat_event_pipe
[0] != -1);
5493 if (previous
!= enable
)
5497 block_child_signals (&prev_mask
);
5501 if (pipe (linux_nat_event_pipe
) == -1)
5502 internal_error (__FILE__
, __LINE__
,
5503 "creating event pipe failed.");
5505 fcntl (linux_nat_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
5506 fcntl (linux_nat_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
5510 close (linux_nat_event_pipe
[0]);
5511 close (linux_nat_event_pipe
[1]);
5512 linux_nat_event_pipe
[0] = -1;
5513 linux_nat_event_pipe
[1] = -1;
5516 restore_child_signals_mask (&prev_mask
);
5522 /* target_async implementation. */
5525 linux_nat_async (void (*callback
) (enum inferior_event_type event_type
,
5526 void *context
), void *context
)
5528 if (callback
!= NULL
)
5530 async_client_callback
= callback
;
5531 async_client_context
= context
;
5532 if (!linux_async_pipe (1))
5534 add_file_handler (linux_nat_event_pipe
[0],
5535 handle_target_event
, NULL
);
5536 /* There may be pending events to handle. Tell the event loop
5543 async_client_callback
= callback
;
5544 async_client_context
= context
;
5545 delete_file_handler (linux_nat_event_pipe
[0]);
5546 linux_async_pipe (0);
5551 /* Stop an LWP, and push a TARGET_SIGNAL_0 stop status if no other
5555 linux_nat_stop_lwp (struct lwp_info
*lwp
, void *data
)
5559 ptid_t ptid
= lwp
->ptid
;
5561 if (debug_linux_nat
)
5562 fprintf_unfiltered (gdb_stdlog
,
5563 "LNSL: running -> suspending %s\n",
5564 target_pid_to_str (lwp
->ptid
));
5567 if (lwp
->last_resume_kind
== resume_stop
)
5569 if (debug_linux_nat
)
5570 fprintf_unfiltered (gdb_stdlog
,
5571 "linux-nat: already stopping LWP %ld at "
5573 ptid_get_lwp (lwp
->ptid
));
5577 stop_callback (lwp
, NULL
);
5578 lwp
->last_resume_kind
= resume_stop
;
5582 /* Already known to be stopped; do nothing. */
5584 if (debug_linux_nat
)
5586 if (find_thread_ptid (lwp
->ptid
)->stop_requested
)
5587 fprintf_unfiltered (gdb_stdlog
,
5588 "LNSL: already stopped/stop_requested %s\n",
5589 target_pid_to_str (lwp
->ptid
));
5591 fprintf_unfiltered (gdb_stdlog
,
5592 "LNSL: already stopped/no "
5593 "stop_requested yet %s\n",
5594 target_pid_to_str (lwp
->ptid
));
5601 linux_nat_stop (ptid_t ptid
)
5604 iterate_over_lwps (ptid
, linux_nat_stop_lwp
, NULL
);
5606 linux_ops
->to_stop (ptid
);
5610 linux_nat_close (int quitting
)
5612 /* Unregister from the event loop. */
5613 if (target_is_async_p ())
5614 target_async (NULL
, 0);
5616 if (linux_ops
->to_close
)
5617 linux_ops
->to_close (quitting
);
5620 /* When requests are passed down from the linux-nat layer to the
5621 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
5622 used. The address space pointer is stored in the inferior object,
5623 but the common code that is passed such ptid can't tell whether
5624 lwpid is a "main" process id or not (it assumes so). We reverse
5625 look up the "main" process id from the lwp here. */
5627 struct address_space
*
5628 linux_nat_thread_address_space (struct target_ops
*t
, ptid_t ptid
)
5630 struct lwp_info
*lwp
;
5631 struct inferior
*inf
;
5634 pid
= GET_LWP (ptid
);
5635 if (GET_LWP (ptid
) == 0)
5637 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
5639 lwp
= find_lwp_pid (ptid
);
5640 pid
= GET_PID (lwp
->ptid
);
5644 /* A (pid,lwpid,0) ptid. */
5645 pid
= GET_PID (ptid
);
5648 inf
= find_inferior_pid (pid
);
5649 gdb_assert (inf
!= NULL
);
5654 linux_nat_core_of_thread_1 (ptid_t ptid
)
5656 struct cleanup
*back_to
;
5659 char *content
= NULL
;
5662 int content_read
= 0;
5666 filename
= xstrprintf ("/proc/%d/task/%ld/stat",
5667 GET_PID (ptid
), GET_LWP (ptid
));
5668 back_to
= make_cleanup (xfree
, filename
);
5670 f
= fopen (filename
, "r");
5673 do_cleanups (back_to
);
5677 make_cleanup_fclose (f
);
5683 content
= xrealloc (content
, content_read
+ 1024);
5684 n
= fread (content
+ content_read
, 1, 1024, f
);
5688 content
[content_read
] = '\0';
5693 make_cleanup (xfree
, content
);
5695 p
= strchr (content
, '(');
5699 p
= strchr (p
, ')');
5703 /* If the first field after program name has index 0, then core number is
5704 the field with index 36. There's no constant for that anywhere. */
5706 p
= strtok_r (p
, " ", &ts
);
5707 for (i
= 0; p
!= NULL
&& i
!= 36; ++i
)
5708 p
= strtok_r (NULL
, " ", &ts
);
5710 if (p
== NULL
|| sscanf (p
, "%d", &core
) == 0)
5713 do_cleanups (back_to
);
5718 /* Return the cached value of the processor core for thread PTID. */
5721 linux_nat_core_of_thread (struct target_ops
*ops
, ptid_t ptid
)
5723 struct lwp_info
*info
= find_lwp_pid (ptid
);
5731 linux_nat_add_target (struct target_ops
*t
)
5733 /* Save the provided single-threaded target. We save this in a separate
5734 variable because another target we've inherited from (e.g. inf-ptrace)
5735 may have saved a pointer to T; we want to use it for the final
5736 process stratum target. */
5737 linux_ops_saved
= *t
;
5738 linux_ops
= &linux_ops_saved
;
5740 /* Override some methods for multithreading. */
5741 t
->to_create_inferior
= linux_nat_create_inferior
;
5742 t
->to_attach
= linux_nat_attach
;
5743 t
->to_detach
= linux_nat_detach
;
5744 t
->to_resume
= linux_nat_resume
;
5745 t
->to_wait
= linux_nat_wait
;
5746 t
->to_pass_signals
= linux_nat_pass_signals
;
5747 t
->to_xfer_partial
= linux_nat_xfer_partial
;
5748 t
->to_kill
= linux_nat_kill
;
5749 t
->to_mourn_inferior
= linux_nat_mourn_inferior
;
5750 t
->to_thread_alive
= linux_nat_thread_alive
;
5751 t
->to_pid_to_str
= linux_nat_pid_to_str
;
5752 t
->to_thread_name
= linux_nat_thread_name
;
5753 t
->to_has_thread_control
= tc_schedlock
;
5754 t
->to_thread_address_space
= linux_nat_thread_address_space
;
5755 t
->to_stopped_by_watchpoint
= linux_nat_stopped_by_watchpoint
;
5756 t
->to_stopped_data_address
= linux_nat_stopped_data_address
;
5758 t
->to_can_async_p
= linux_nat_can_async_p
;
5759 t
->to_is_async_p
= linux_nat_is_async_p
;
5760 t
->to_supports_non_stop
= linux_nat_supports_non_stop
;
5761 t
->to_async
= linux_nat_async
;
5762 t
->to_terminal_inferior
= linux_nat_terminal_inferior
;
5763 t
->to_terminal_ours
= linux_nat_terminal_ours
;
5764 t
->to_close
= linux_nat_close
;
5766 /* Methods for non-stop support. */
5767 t
->to_stop
= linux_nat_stop
;
5769 t
->to_supports_multi_process
= linux_nat_supports_multi_process
;
5771 t
->to_supports_disable_randomization
5772 = linux_nat_supports_disable_randomization
;
5774 t
->to_core_of_thread
= linux_nat_core_of_thread
;
5776 /* We don't change the stratum; this target will sit at
5777 process_stratum and thread_db will set at thread_stratum. This
5778 is a little strange, since this is a multi-threaded-capable
5779 target, but we want to be on the stack below thread_db, and we
5780 also want to be used for single-threaded processes. */
5785 /* Register a method to call whenever a new thread is attached. */
5787 linux_nat_set_new_thread (struct target_ops
*t
, void (*new_thread
) (ptid_t
))
5789 /* Save the pointer. We only support a single registered instance
5790 of the GNU/Linux native target, so we do not need to map this to
5792 linux_nat_new_thread
= new_thread
;
5795 /* Register a method that converts a siginfo object between the layout
5796 that ptrace returns, and the layout in the architecture of the
5799 linux_nat_set_siginfo_fixup (struct target_ops
*t
,
5800 int (*siginfo_fixup
) (struct siginfo
*,
5804 /* Save the pointer. */
5805 linux_nat_siginfo_fixup
= siginfo_fixup
;
5808 /* Return the saved siginfo associated with PTID. */
5810 linux_nat_get_siginfo (ptid_t ptid
)
5812 struct lwp_info
*lp
= find_lwp_pid (ptid
);
5814 gdb_assert (lp
!= NULL
);
5816 return &lp
->siginfo
;
5819 /* Provide a prototype to silence -Wmissing-prototypes. */
5820 extern initialize_file_ftype _initialize_linux_nat
;
5823 _initialize_linux_nat (void)
5825 add_info ("proc", linux_nat_info_proc_cmd
, _("\
5826 Show /proc process information about any running process.\n\
5827 Specify any process id, or use the program being debugged by default.\n\
5828 Specify any of the following keywords for detailed info:\n\
5829 mappings -- list of mapped memory regions.\n\
5830 stat -- list a bunch of random process info.\n\
5831 status -- list a different bunch of random process info.\n\
5832 all -- list all available /proc info."));
5834 add_setshow_zinteger_cmd ("lin-lwp", class_maintenance
,
5835 &debug_linux_nat
, _("\
5836 Set debugging of GNU/Linux lwp module."), _("\
5837 Show debugging of GNU/Linux lwp module."), _("\
5838 Enables printf debugging output."),
5840 show_debug_linux_nat
,
5841 &setdebuglist
, &showdebuglist
);
5843 /* Save this mask as the default. */
5844 sigprocmask (SIG_SETMASK
, NULL
, &normal_mask
);
5846 /* Install a SIGCHLD handler. */
5847 sigchld_action
.sa_handler
= sigchld_handler
;
5848 sigemptyset (&sigchld_action
.sa_mask
);
5849 sigchld_action
.sa_flags
= SA_RESTART
;
5851 /* Make it the default. */
5852 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
5854 /* Make sure we don't block SIGCHLD during a sigsuspend. */
5855 sigprocmask (SIG_SETMASK
, NULL
, &suspend_mask
);
5856 sigdelset (&suspend_mask
, SIGCHLD
);
5858 sigemptyset (&blocked_mask
);
5862 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
5863 the GNU/Linux Threads library and therefore doesn't really belong
5866 /* Read variable NAME in the target and return its value if found.
5867 Otherwise return zero. It is assumed that the type of the variable
5871 get_signo (const char *name
)
5873 struct minimal_symbol
*ms
;
5876 ms
= lookup_minimal_symbol (name
, NULL
, NULL
);
5880 if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms
), (gdb_byte
*) &signo
,
5881 sizeof (signo
)) != 0)
5887 /* Return the set of signals used by the threads library in *SET. */
5890 lin_thread_get_thread_signals (sigset_t
*set
)
5892 struct sigaction action
;
5893 int restart
, cancel
;
5895 sigemptyset (&blocked_mask
);
5898 restart
= get_signo ("__pthread_sig_restart");
5899 cancel
= get_signo ("__pthread_sig_cancel");
5901 /* LinuxThreads normally uses the first two RT signals, but in some legacy
5902 cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
5903 not provide any way for the debugger to query the signal numbers -
5904 fortunately they don't change! */
5907 restart
= __SIGRTMIN
;
5910 cancel
= __SIGRTMIN
+ 1;
5912 sigaddset (set
, restart
);
5913 sigaddset (set
, cancel
);
5915 /* The GNU/Linux Threads library makes terminating threads send a
5916 special "cancel" signal instead of SIGCHLD. Make sure we catch
5917 those (to prevent them from terminating GDB itself, which is
5918 likely to be their default action) and treat them the same way as
5921 action
.sa_handler
= sigchld_handler
;
5922 sigemptyset (&action
.sa_mask
);
5923 action
.sa_flags
= SA_RESTART
;
5924 sigaction (cancel
, &action
, NULL
);
5926 /* We block the "cancel" signal throughout this code ... */
5927 sigaddset (&blocked_mask
, cancel
);
5928 sigprocmask (SIG_BLOCK
, &blocked_mask
, NULL
);
5930 /* ... except during a sigsuspend. */
5931 sigdelset (&suspend_mask
, cancel
);