1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
4 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-fork.h"
34 #include "gdbthread.h"
38 #include "inf-ptrace.h"
40 #include <sys/param.h> /* for MAXPATHLEN */
41 #include <sys/procfs.h> /* for elf_gregset etc. */
42 #include "elf-bfd.h" /* for elfcore_write_* */
43 #include "gregset.h" /* for gregset */
44 #include "gdbcore.h" /* for get_exec_file */
45 #include <ctype.h> /* for isdigit */
46 #include "gdbthread.h" /* for struct thread_info etc. */
47 #include "gdb_stat.h" /* for struct stat */
48 #include <fcntl.h> /* for O_RDONLY */
50 #include "event-loop.h"
51 #include "event-top.h"
53 #include <sys/types.h>
54 #include "gdb_dirent.h"
55 #include "xml-support.h"
58 #ifdef HAVE_PERSONALITY
59 # include <sys/personality.h>
60 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
61 # define ADDR_NO_RANDOMIZE 0x0040000
63 #endif /* HAVE_PERSONALITY */
65 /* This comment documents high-level logic of this file.
67 Waiting for events in sync mode
68 ===============================
70 When waiting for an event in a specific thread, we just use waitpid, passing
71 the specific pid, and not passing WNOHANG.
73 When waiting for an event in all threads, waitpid is not quite good. Prior to
74 version 2.4, Linux can either wait for event in main thread, or in secondary
75 threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might
76 miss an event. The solution is to use non-blocking waitpid, together with
77 sigsuspend. First, we use non-blocking waitpid to get an event in the main
78 process, if any. Second, we use non-blocking waitpid with the __WCLONED
79 flag to check for events in cloned processes. If nothing is found, we use
80 sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something
81 happened to a child process -- and SIGCHLD will be delivered both for events
82 in main debugged process and in cloned processes. As soon as we know there's
83 an event, we get back to calling nonblocking waitpid with and without __WCLONED.
85 Note that SIGCHLD should be blocked between waitpid and sigsuspend calls,
86 so that we don't miss a signal. If SIGCHLD arrives in between, when it's
87 blocked, the signal becomes pending and sigsuspend immediately
88 notices it and returns.
90 Waiting for events in async mode
91 ================================
93 In async mode, GDB should always be ready to handle both user input
94 and target events, so neither blocking waitpid nor sigsuspend are
95 viable options. Instead, we should asynchronously notify the GDB main
96 event loop whenever there's an unprocessed event from the target. We
97 detect asynchronous target events by handling SIGCHLD signals. To
98 notify the event loop about target events, the self-pipe trick is used
99 --- a pipe is registered as waitable event source in the event loop,
100 the event loop select/poll's on the read end of this pipe (as well on
101 other event sources, e.g., stdin), and the SIGCHLD handler writes a
102 byte to this pipe. This is more portable than relying on
103 pselect/ppoll, since on kernels that lack those syscalls, libc
104 emulates them with select/poll+sigprocmask, and that is racy
105 (a.k.a. plain broken).
107 Obviously, if we fail to notify the event loop if there's a target
108 event, it's bad. OTOH, if we notify the event loop when there's no
109 event from the target, linux_nat_wait will detect that there's no real
110 event to report, and return event of type TARGET_WAITKIND_IGNORE.
111 This is mostly harmless, but it will waste time and is better avoided.
113 The main design point is that every time GDB is outside linux-nat.c,
114 we have a SIGCHLD handler installed that is called when something
115 happens to the target and notifies the GDB event loop. Whenever GDB
116 core decides to handle the event, and calls into linux-nat.c, we
117 process things as in sync mode, except that the we never block in
120 While processing an event, we may end up momentarily blocked in
121 waitpid calls. Those waitpid calls, while blocking, are guarantied to
122 return quickly. E.g., in all-stop mode, before reporting to the core
123 that an LWP hit a breakpoint, all LWPs are stopped by sending them
124 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
125 Note that this is different from blocking indefinitely waiting for the
126 next event --- here, we're already handling an event.
131 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
132 signal is not entirely significant; we just need for a signal to be delivered,
133 so that we can intercept it. SIGSTOP's advantage is that it can not be
134 blocked. A disadvantage is that it is not a real-time signal, so it can only
135 be queued once; we do not keep track of other sources of SIGSTOP.
137 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
138 use them, because they have special behavior when the signal is generated -
139 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
140 kills the entire thread group.
142 A delivered SIGSTOP would stop the entire thread group, not just the thread we
143 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
144 cancel it (by PTRACE_CONT without passing SIGSTOP).
146 We could use a real-time signal instead. This would solve those problems; we
147 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
148 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
149 generates it, and there are races with trying to find a signal that is not
153 #define O_LARGEFILE 0
156 /* If the system headers did not provide the constants, hard-code the normal
158 #ifndef PTRACE_EVENT_FORK
160 #define PTRACE_SETOPTIONS 0x4200
161 #define PTRACE_GETEVENTMSG 0x4201
163 /* options set using PTRACE_SETOPTIONS */
164 #define PTRACE_O_TRACESYSGOOD 0x00000001
165 #define PTRACE_O_TRACEFORK 0x00000002
166 #define PTRACE_O_TRACEVFORK 0x00000004
167 #define PTRACE_O_TRACECLONE 0x00000008
168 #define PTRACE_O_TRACEEXEC 0x00000010
169 #define PTRACE_O_TRACEVFORKDONE 0x00000020
170 #define PTRACE_O_TRACEEXIT 0x00000040
172 /* Wait extended result codes for the above trace options. */
173 #define PTRACE_EVENT_FORK 1
174 #define PTRACE_EVENT_VFORK 2
175 #define PTRACE_EVENT_CLONE 3
176 #define PTRACE_EVENT_EXEC 4
177 #define PTRACE_EVENT_VFORK_DONE 5
178 #define PTRACE_EVENT_EXIT 6
180 #endif /* PTRACE_EVENT_FORK */
182 /* We can't always assume that this flag is available, but all systems
183 with the ptrace event handlers also have __WALL, so it's safe to use
186 #define __WALL 0x40000000 /* Wait for any child. */
189 #ifndef PTRACE_GETSIGINFO
190 # define PTRACE_GETSIGINFO 0x4202
191 # define PTRACE_SETSIGINFO 0x4203
194 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
195 the use of the multi-threaded target. */
196 static struct target_ops
*linux_ops
;
197 static struct target_ops linux_ops_saved
;
199 /* The method to call, if any, when a new thread is attached. */
200 static void (*linux_nat_new_thread
) (ptid_t
);
202 /* The method to call, if any, when the siginfo object needs to be
203 converted between the layout returned by ptrace, and the layout in
204 the architecture of the inferior. */
205 static int (*linux_nat_siginfo_fixup
) (struct siginfo
*,
209 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
210 Called by our to_xfer_partial. */
211 static LONGEST (*super_xfer_partial
) (struct target_ops
*,
213 const char *, gdb_byte
*,
217 static int debug_linux_nat
;
219 show_debug_linux_nat (struct ui_file
*file
, int from_tty
,
220 struct cmd_list_element
*c
, const char *value
)
222 fprintf_filtered (file
, _("Debugging of GNU/Linux lwp module is %s.\n"),
226 static int debug_linux_nat_async
= 0;
228 show_debug_linux_nat_async (struct ui_file
*file
, int from_tty
,
229 struct cmd_list_element
*c
, const char *value
)
231 fprintf_filtered (file
, _("Debugging of GNU/Linux async lwp module is %s.\n"),
235 static int disable_randomization
= 1;
238 show_disable_randomization (struct ui_file
*file
, int from_tty
,
239 struct cmd_list_element
*c
, const char *value
)
241 #ifdef HAVE_PERSONALITY
242 fprintf_filtered (file
, _("\
243 Disabling randomization of debuggee's virtual address space is %s.\n"),
245 #else /* !HAVE_PERSONALITY */
247 Disabling randomization of debuggee's virtual address space is unsupported on\n\
248 this platform.\n"), file
);
249 #endif /* !HAVE_PERSONALITY */
253 set_disable_randomization (char *args
, int from_tty
, struct cmd_list_element
*c
)
255 #ifndef HAVE_PERSONALITY
257 Disabling randomization of debuggee's virtual address space is unsupported on\n\
259 #endif /* !HAVE_PERSONALITY */
262 static int linux_parent_pid
;
264 struct simple_pid_list
268 struct simple_pid_list
*next
;
270 struct simple_pid_list
*stopped_pids
;
272 /* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACEFORK
273 can not be used, 1 if it can. */
275 static int linux_supports_tracefork_flag
= -1;
277 /* If we have PTRACE_O_TRACEFORK, this flag indicates whether we also have
278 PTRACE_O_TRACEVFORKDONE. */
280 static int linux_supports_tracevforkdone_flag
= -1;
282 /* Async mode support */
284 /* Zero if the async mode, although enabled, is masked, which means
285 linux_nat_wait should behave as if async mode was off. */
286 static int linux_nat_async_mask_value
= 1;
288 /* The read/write ends of the pipe registered as waitable file in the
290 static int linux_nat_event_pipe
[2] = { -1, -1 };
292 /* Flush the event pipe. */
295 async_file_flush (void)
302 ret
= read (linux_nat_event_pipe
[0], &buf
, 1);
304 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
307 /* Put something (anything, doesn't matter what, or how much) in event
308 pipe, so that the select/poll in the event-loop realizes we have
309 something to process. */
312 async_file_mark (void)
316 /* It doesn't really matter what the pipe contains, as long we end
317 up with something in it. Might as well flush the previous
323 ret
= write (linux_nat_event_pipe
[1], "+", 1);
325 while (ret
== -1 && errno
== EINTR
);
327 /* Ignore EAGAIN. If the pipe is full, the event loop will already
328 be awakened anyway. */
331 static void linux_nat_async (void (*callback
)
332 (enum inferior_event_type event_type
, void *context
),
334 static int linux_nat_async_mask (int mask
);
335 static int kill_lwp (int lwpid
, int signo
);
337 static int stop_callback (struct lwp_info
*lp
, void *data
);
339 static void block_child_signals (sigset_t
*prev_mask
);
340 static void restore_child_signals_mask (sigset_t
*prev_mask
);
342 /* Trivial list manipulation functions to keep track of a list of
343 new stopped processes. */
345 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
347 struct simple_pid_list
*new_pid
= xmalloc (sizeof (struct simple_pid_list
));
349 new_pid
->status
= status
;
350 new_pid
->next
= *listp
;
355 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *status
)
357 struct simple_pid_list
**p
;
359 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
360 if ((*p
)->pid
== pid
)
362 struct simple_pid_list
*next
= (*p
)->next
;
363 *status
= (*p
)->status
;
372 linux_record_stopped_pid (int pid
, int status
)
374 add_to_pid_list (&stopped_pids
, pid
, status
);
378 /* A helper function for linux_test_for_tracefork, called after fork (). */
381 linux_tracefork_child (void)
385 ptrace (PTRACE_TRACEME
, 0, 0, 0);
386 kill (getpid (), SIGSTOP
);
391 /* Wrapper function for waitpid which handles EINTR. */
394 my_waitpid (int pid
, int *status
, int flags
)
400 ret
= waitpid (pid
, status
, flags
);
402 while (ret
== -1 && errno
== EINTR
);
407 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events.
409 First, we try to enable fork tracing on ORIGINAL_PID. If this fails,
410 we know that the feature is not available. This may change the tracing
411 options for ORIGINAL_PID, but we'll be setting them shortly anyway.
413 However, if it succeeds, we don't know for sure that the feature is
414 available; old versions of PTRACE_SETOPTIONS ignored unknown options. We
415 create a child process, attach to it, use PTRACE_SETOPTIONS to enable
416 fork tracing, and let it fork. If the process exits, we assume that we
417 can't use TRACEFORK; if we get the fork notification, and we can extract
418 the new child's PID, then we assume that we can. */
421 linux_test_for_tracefork (int original_pid
)
423 int child_pid
, ret
, status
;
427 /* We don't want those ptrace calls to be interrupted. */
428 block_child_signals (&prev_mask
);
430 linux_supports_tracefork_flag
= 0;
431 linux_supports_tracevforkdone_flag
= 0;
433 ret
= ptrace (PTRACE_SETOPTIONS
, original_pid
, 0, PTRACE_O_TRACEFORK
);
436 restore_child_signals_mask (&prev_mask
);
442 perror_with_name (("fork"));
445 linux_tracefork_child ();
447 ret
= my_waitpid (child_pid
, &status
, 0);
449 perror_with_name (("waitpid"));
450 else if (ret
!= child_pid
)
451 error (_("linux_test_for_tracefork: waitpid: unexpected result %d."), ret
);
452 if (! WIFSTOPPED (status
))
453 error (_("linux_test_for_tracefork: waitpid: unexpected status %d."), status
);
455 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0, PTRACE_O_TRACEFORK
);
458 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
461 warning (_("linux_test_for_tracefork: failed to kill child"));
462 restore_child_signals_mask (&prev_mask
);
466 ret
= my_waitpid (child_pid
, &status
, 0);
467 if (ret
!= child_pid
)
468 warning (_("linux_test_for_tracefork: failed to wait for killed child"));
469 else if (!WIFSIGNALED (status
))
470 warning (_("linux_test_for_tracefork: unexpected wait status 0x%x from "
471 "killed child"), status
);
473 restore_child_signals_mask (&prev_mask
);
477 /* Check whether PTRACE_O_TRACEVFORKDONE is available. */
478 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0,
479 PTRACE_O_TRACEFORK
| PTRACE_O_TRACEVFORKDONE
);
480 linux_supports_tracevforkdone_flag
= (ret
== 0);
482 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
484 warning (_("linux_test_for_tracefork: failed to resume child"));
486 ret
= my_waitpid (child_pid
, &status
, 0);
488 if (ret
== child_pid
&& WIFSTOPPED (status
)
489 && status
>> 16 == PTRACE_EVENT_FORK
)
492 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
493 if (ret
== 0 && second_pid
!= 0)
497 linux_supports_tracefork_flag
= 1;
498 my_waitpid (second_pid
, &second_status
, 0);
499 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
501 warning (_("linux_test_for_tracefork: failed to kill second child"));
502 my_waitpid (second_pid
, &status
, 0);
506 warning (_("linux_test_for_tracefork: unexpected result from waitpid "
507 "(%d, status 0x%x)"), ret
, status
);
509 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
511 warning (_("linux_test_for_tracefork: failed to kill child"));
512 my_waitpid (child_pid
, &status
, 0);
514 restore_child_signals_mask (&prev_mask
);
517 /* Return non-zero iff we have tracefork functionality available.
518 This function also sets linux_supports_tracefork_flag. */
521 linux_supports_tracefork (int pid
)
523 if (linux_supports_tracefork_flag
== -1)
524 linux_test_for_tracefork (pid
);
525 return linux_supports_tracefork_flag
;
529 linux_supports_tracevforkdone (int pid
)
531 if (linux_supports_tracefork_flag
== -1)
532 linux_test_for_tracefork (pid
);
533 return linux_supports_tracevforkdone_flag
;
538 linux_enable_event_reporting (ptid_t ptid
)
540 int pid
= ptid_get_lwp (ptid
);
544 pid
= ptid_get_pid (ptid
);
546 if (! linux_supports_tracefork (pid
))
549 options
= PTRACE_O_TRACEFORK
| PTRACE_O_TRACEVFORK
| PTRACE_O_TRACEEXEC
550 | PTRACE_O_TRACECLONE
;
551 if (linux_supports_tracevforkdone (pid
))
552 options
|= PTRACE_O_TRACEVFORKDONE
;
554 /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support
555 read-only process state. */
557 ptrace (PTRACE_SETOPTIONS
, pid
, 0, options
);
561 linux_child_post_attach (int pid
)
563 linux_enable_event_reporting (pid_to_ptid (pid
));
564 check_for_thread_db ();
568 linux_child_post_startup_inferior (ptid_t ptid
)
570 linux_enable_event_reporting (ptid
);
571 check_for_thread_db ();
575 linux_child_follow_fork (struct target_ops
*ops
, int follow_child
)
579 struct target_waitstatus last_status
;
581 int parent_pid
, child_pid
;
583 block_child_signals (&prev_mask
);
585 get_last_target_status (&last_ptid
, &last_status
);
586 has_vforked
= (last_status
.kind
== TARGET_WAITKIND_VFORKED
);
587 parent_pid
= ptid_get_lwp (last_ptid
);
589 parent_pid
= ptid_get_pid (last_ptid
);
590 child_pid
= PIDGET (last_status
.value
.related_pid
);
594 /* We're already attached to the parent, by default. */
596 /* Before detaching from the child, remove all breakpoints from
597 it. If we forked, then this has already been taken care of
598 by infrun.c. If we vforked however, any breakpoint inserted
599 in the parent is visible in the child, even those added while
600 stopped in a vfork catchpoint. This won't actually modify
601 the breakpoint list, but will physically remove the
602 breakpoints from the child. This will remove the breakpoints
603 from the parent also, but they'll be reinserted below. */
605 detach_breakpoints (child_pid
);
607 /* Detach new forked process? */
610 if (info_verbose
|| debug_linux_nat
)
612 target_terminal_ours ();
613 fprintf_filtered (gdb_stdlog
,
614 "Detaching after fork from child process %d.\n",
618 ptrace (PTRACE_DETACH
, child_pid
, 0, 0);
622 struct fork_info
*fp
;
623 struct inferior
*parent_inf
, *child_inf
;
625 /* Add process to GDB's tables. */
626 child_inf
= add_inferior (child_pid
);
628 parent_inf
= find_inferior_pid (GET_PID (last_ptid
));
629 child_inf
->attach_flag
= parent_inf
->attach_flag
;
630 copy_terminal_info (child_inf
, parent_inf
);
632 /* Retain child fork in ptrace (stopped) state. */
633 fp
= find_fork_pid (child_pid
);
635 fp
= add_fork (child_pid
);
636 fork_save_infrun_state (fp
, 0);
641 gdb_assert (linux_supports_tracefork_flag
>= 0);
642 if (linux_supports_tracevforkdone (0))
646 ptrace (PTRACE_CONT
, parent_pid
, 0, 0);
647 my_waitpid (parent_pid
, &status
, __WALL
);
648 if ((status
>> 16) != PTRACE_EVENT_VFORK_DONE
)
649 warning (_("Unexpected waitpid result %06x when waiting for "
650 "vfork-done"), status
);
654 /* We can't insert breakpoints until the child has
655 finished with the shared memory region. We need to
656 wait until that happens. Ideal would be to just
658 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
659 - waitpid (parent_pid, &status, __WALL);
660 However, most architectures can't handle a syscall
661 being traced on the way out if it wasn't traced on
664 We might also think to loop, continuing the child
665 until it exits or gets a SIGTRAP. One problem is
666 that the child might call ptrace with PTRACE_TRACEME.
668 There's no simple and reliable way to figure out when
669 the vforked child will be done with its copy of the
670 shared memory. We could step it out of the syscall,
671 two instructions, let it go, and then single-step the
672 parent once. When we have hardware single-step, this
673 would work; with software single-step it could still
674 be made to work but we'd have to be able to insert
675 single-step breakpoints in the child, and we'd have
676 to insert -just- the single-step breakpoint in the
677 parent. Very awkward.
679 In the end, the best we can do is to make sure it
680 runs for a little while. Hopefully it will be out of
681 range of any breakpoints we reinsert. Usually this
682 is only the single-step breakpoint at vfork's return
688 /* Since we vforked, breakpoints were removed in the parent
689 too. Put them back. */
690 reattach_breakpoints (parent_pid
);
695 struct thread_info
*last_tp
= find_thread_pid (last_ptid
);
696 struct thread_info
*tp
;
697 char child_pid_spelling
[40];
698 struct inferior
*parent_inf
, *child_inf
;
700 /* Copy user stepping state to the new inferior thread. */
701 struct breakpoint
*step_resume_breakpoint
= last_tp
->step_resume_breakpoint
;
702 CORE_ADDR step_range_start
= last_tp
->step_range_start
;
703 CORE_ADDR step_range_end
= last_tp
->step_range_end
;
704 struct frame_id step_frame_id
= last_tp
->step_frame_id
;
706 /* Otherwise, deleting the parent would get rid of this
708 last_tp
->step_resume_breakpoint
= NULL
;
710 /* Before detaching from the parent, remove all breakpoints from it. */
711 remove_breakpoints ();
713 if (info_verbose
|| debug_linux_nat
)
715 target_terminal_ours ();
716 fprintf_filtered (gdb_stdlog
,
717 "Attaching after fork to child process %d.\n",
721 /* Add the new inferior first, so that the target_detach below
722 doesn't unpush the target. */
724 child_inf
= add_inferior (child_pid
);
726 parent_inf
= find_inferior_pid (GET_PID (last_ptid
));
727 child_inf
->attach_flag
= parent_inf
->attach_flag
;
728 copy_terminal_info (child_inf
, parent_inf
);
730 /* If we're vforking, we may want to hold on to the parent until
731 the child exits or execs. At exec time we can remove the old
732 breakpoints from the parent and detach it; at exit time we
733 could do the same (or even, sneakily, resume debugging it - the
734 child's exec has failed, or something similar).
736 This doesn't clean up "properly", because we can't call
737 target_detach, but that's OK; if the current target is "child",
738 then it doesn't need any further cleanups, and lin_lwp will
739 generally not encounter vfork (vfork is defined to fork
742 The holding part is very easy if we have VFORKDONE events;
743 but keeping track of both processes is beyond GDB at the
744 moment. So we don't expose the parent to the rest of GDB.
745 Instead we quietly hold onto it until such time as we can
750 linux_parent_pid
= parent_pid
;
751 detach_inferior (parent_pid
);
753 else if (!detach_fork
)
755 struct fork_info
*fp
;
756 /* Retain parent fork in ptrace (stopped) state. */
757 fp
= find_fork_pid (parent_pid
);
759 fp
= add_fork (parent_pid
);
760 fork_save_infrun_state (fp
, 0);
762 /* Also add an entry for the child fork. */
763 fp
= find_fork_pid (child_pid
);
765 fp
= add_fork (child_pid
);
766 fork_save_infrun_state (fp
, 0);
769 target_detach (NULL
, 0);
771 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
773 linux_nat_switch_fork (inferior_ptid
);
774 check_for_thread_db ();
776 tp
= inferior_thread ();
777 tp
->step_resume_breakpoint
= step_resume_breakpoint
;
778 tp
->step_range_start
= step_range_start
;
779 tp
->step_range_end
= step_range_end
;
780 tp
->step_frame_id
= step_frame_id
;
782 /* Reset breakpoints in the child as appropriate. */
783 follow_inferior_reset_breakpoints ();
786 restore_child_signals_mask (&prev_mask
);
792 linux_child_insert_fork_catchpoint (int pid
)
794 if (! linux_supports_tracefork (pid
))
795 error (_("Your system does not support fork catchpoints."));
799 linux_child_insert_vfork_catchpoint (int pid
)
801 if (!linux_supports_tracefork (pid
))
802 error (_("Your system does not support vfork catchpoints."));
806 linux_child_insert_exec_catchpoint (int pid
)
808 if (!linux_supports_tracefork (pid
))
809 error (_("Your system does not support exec catchpoints."));
812 /* On GNU/Linux there are no real LWP's. The closest thing to LWP's
813 are processes sharing the same VM space. A multi-threaded process
814 is basically a group of such processes. However, such a grouping
815 is almost entirely a user-space issue; the kernel doesn't enforce
816 such a grouping at all (this might change in the future). In
817 general, we'll rely on the threads library (i.e. the GNU/Linux
818 Threads library) to provide such a grouping.
820 It is perfectly well possible to write a multi-threaded application
821 without the assistance of a threads library, by using the clone
822 system call directly. This module should be able to give some
823 rudimentary support for debugging such applications if developers
824 specify the CLONE_PTRACE flag in the clone system call, and are
825 using the Linux kernel 2.4 or above.
827 Note that there are some peculiarities in GNU/Linux that affect
830 - In general one should specify the __WCLONE flag to waitpid in
831 order to make it report events for any of the cloned processes
832 (and leave it out for the initial process). However, if a cloned
833 process has exited the exit status is only reported if the
834 __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
835 we cannot use it since GDB must work on older systems too.
837 - When a traced, cloned process exits and is waited for by the
838 debugger, the kernel reassigns it to the original parent and
839 keeps it around as a "zombie". Somehow, the GNU/Linux Threads
840 library doesn't notice this, which leads to the "zombie problem":
841 When debugged a multi-threaded process that spawns a lot of
842 threads will run out of processes, even if the threads exit,
843 because the "zombies" stay around. */
845 /* List of known LWPs. */
846 struct lwp_info
*lwp_list
;
849 /* Original signal mask. */
850 static sigset_t normal_mask
;
852 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
853 _initialize_linux_nat. */
854 static sigset_t suspend_mask
;
856 /* Signals to block to make that sigsuspend work. */
857 static sigset_t blocked_mask
;
859 /* SIGCHLD action. */
860 struct sigaction sigchld_action
;
862 /* Block child signals (SIGCHLD and linux threads signals), and store
863 the previous mask in PREV_MASK. */
866 block_child_signals (sigset_t
*prev_mask
)
868 /* Make sure SIGCHLD is blocked. */
869 if (!sigismember (&blocked_mask
, SIGCHLD
))
870 sigaddset (&blocked_mask
, SIGCHLD
);
872 sigprocmask (SIG_BLOCK
, &blocked_mask
, prev_mask
);
875 /* Restore child signals mask, previously returned by
876 block_child_signals. */
879 restore_child_signals_mask (sigset_t
*prev_mask
)
881 sigprocmask (SIG_SETMASK
, prev_mask
, NULL
);
885 /* Prototypes for local functions. */
886 static int stop_wait_callback (struct lwp_info
*lp
, void *data
);
887 static int linux_thread_alive (ptid_t ptid
);
888 static char *linux_child_pid_to_exec_file (int pid
);
889 static int cancel_breakpoint (struct lwp_info
*lp
);
892 /* Convert wait status STATUS to a string. Used for printing debug
896 status_to_str (int status
)
900 if (WIFSTOPPED (status
))
901 snprintf (buf
, sizeof (buf
), "%s (stopped)",
902 strsignal (WSTOPSIG (status
)));
903 else if (WIFSIGNALED (status
))
904 snprintf (buf
, sizeof (buf
), "%s (terminated)",
905 strsignal (WSTOPSIG (status
)));
907 snprintf (buf
, sizeof (buf
), "%d (exited)", WEXITSTATUS (status
));
912 /* Initialize the list of LWPs. Note that this module, contrary to
913 what GDB's generic threads layer does for its thread list,
914 re-initializes the LWP lists whenever we mourn or detach (which
915 doesn't involve mourning) the inferior. */
920 struct lwp_info
*lp
, *lpnext
;
922 for (lp
= lwp_list
; lp
; lp
= lpnext
)
931 /* Remove all LWPs belong to PID from the lwp list. */
934 purge_lwp_list (int pid
)
936 struct lwp_info
*lp
, *lpprev
, *lpnext
;
940 for (lp
= lwp_list
; lp
; lp
= lpnext
)
944 if (ptid_get_pid (lp
->ptid
) == pid
)
949 lpprev
->next
= lp
->next
;
958 /* Return the number of known LWPs in the tgid given by PID. */
966 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
967 if (ptid_get_pid (lp
->ptid
) == pid
)
973 /* Add the LWP specified by PID to the list. Return a pointer to the
974 structure describing the new LWP. The LWP should already be stopped
975 (with an exception for the very first LWP). */
977 static struct lwp_info
*
978 add_lwp (ptid_t ptid
)
982 gdb_assert (is_lwp (ptid
));
984 lp
= (struct lwp_info
*) xmalloc (sizeof (struct lwp_info
));
986 memset (lp
, 0, sizeof (struct lwp_info
));
988 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
995 if (num_lwps (GET_PID (ptid
)) > 1 && linux_nat_new_thread
!= NULL
)
996 linux_nat_new_thread (ptid
);
1001 /* Remove the LWP specified by PID from the list. */
1004 delete_lwp (ptid_t ptid
)
1006 struct lwp_info
*lp
, *lpprev
;
1010 for (lp
= lwp_list
; lp
; lpprev
= lp
, lp
= lp
->next
)
1011 if (ptid_equal (lp
->ptid
, ptid
))
1018 lpprev
->next
= lp
->next
;
1020 lwp_list
= lp
->next
;
1025 /* Return a pointer to the structure describing the LWP corresponding
1026 to PID. If no corresponding LWP could be found, return NULL. */
1028 static struct lwp_info
*
1029 find_lwp_pid (ptid_t ptid
)
1031 struct lwp_info
*lp
;
1035 lwp
= GET_LWP (ptid
);
1037 lwp
= GET_PID (ptid
);
1039 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
1040 if (lwp
== GET_LWP (lp
->ptid
))
1046 /* Returns true if PTID matches filter FILTER. FILTER can be the wild
1047 card MINUS_ONE_PTID (all ptid match it); can be a ptid representing
1048 a process (ptid_is_pid returns true), in which case, all lwps of
1049 that give process match, lwps of other process do not; or, it can
1050 represent a specific thread, in which case, only that thread will
1051 match true. PTID must represent an LWP, it can never be a wild
1055 ptid_match (ptid_t ptid
, ptid_t filter
)
1057 /* Since both parameters have the same type, prevent easy mistakes
1059 gdb_assert (!ptid_equal (ptid
, minus_one_ptid
)
1060 && !ptid_equal (ptid
, null_ptid
));
1062 if (ptid_equal (filter
, minus_one_ptid
))
1064 if (ptid_is_pid (filter
)
1065 && ptid_get_pid (ptid
) == ptid_get_pid (filter
))
1067 else if (ptid_equal (ptid
, filter
))
1073 /* Call CALLBACK with its second argument set to DATA for every LWP in
1074 the list. If CALLBACK returns 1 for a particular LWP, return a
1075 pointer to the structure describing that LWP immediately.
1076 Otherwise return NULL. */
1079 iterate_over_lwps (ptid_t filter
,
1080 int (*callback
) (struct lwp_info
*, void *),
1083 struct lwp_info
*lp
, *lpnext
;
1085 for (lp
= lwp_list
; lp
; lp
= lpnext
)
1089 if (ptid_match (lp
->ptid
, filter
))
1091 if ((*callback
) (lp
, data
))
1099 /* Update our internal state when changing from one fork (checkpoint,
1100 et cetera) to another indicated by NEW_PTID. We can only switch
1101 single-threaded applications, so we only create one new LWP, and
1102 the previous list is discarded. */
1105 linux_nat_switch_fork (ptid_t new_ptid
)
1107 struct lwp_info
*lp
;
1110 lp
= add_lwp (new_ptid
);
1113 init_thread_list ();
1114 add_thread_silent (new_ptid
);
1117 /* Handle the exit of a single thread LP. */
1120 exit_lwp (struct lwp_info
*lp
)
1122 struct thread_info
*th
= find_thread_pid (lp
->ptid
);
1126 if (print_thread_events
)
1127 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp
->ptid
));
1129 delete_thread (lp
->ptid
);
1132 delete_lwp (lp
->ptid
);
1135 /* Return an lwp's tgid, found in `/proc/PID/status'. */
1138 linux_proc_get_tgid (int lwpid
)
1144 snprintf (buf
, sizeof (buf
), "/proc/%d/status", (int) lwpid
);
1145 status_file
= fopen (buf
, "r");
1146 if (status_file
!= NULL
)
1148 while (fgets (buf
, sizeof (buf
), status_file
))
1150 if (strncmp (buf
, "Tgid:", 5) == 0)
1152 tgid
= strtoul (buf
+ strlen ("Tgid:"), NULL
, 10);
1157 fclose (status_file
);
1163 /* Detect `T (stopped)' in `/proc/PID/status'.
1164 Other states including `T (tracing stop)' are reported as false. */
1167 pid_is_stopped (pid_t pid
)
1173 snprintf (buf
, sizeof (buf
), "/proc/%d/status", (int) pid
);
1174 status_file
= fopen (buf
, "r");
1175 if (status_file
!= NULL
)
1179 while (fgets (buf
, sizeof (buf
), status_file
))
1181 if (strncmp (buf
, "State:", 6) == 0)
1187 if (have_state
&& strstr (buf
, "T (stopped)") != NULL
)
1189 fclose (status_file
);
1194 /* Wait for the LWP specified by LP, which we have just attached to.
1195 Returns a wait status for that LWP, to cache. */
1198 linux_nat_post_attach_wait (ptid_t ptid
, int first
, int *cloned
,
1201 pid_t new_pid
, pid
= GET_LWP (ptid
);
1204 if (pid_is_stopped (pid
))
1206 if (debug_linux_nat
)
1207 fprintf_unfiltered (gdb_stdlog
,
1208 "LNPAW: Attaching to a stopped process\n");
1210 /* The process is definitely stopped. It is in a job control
1211 stop, unless the kernel predates the TASK_STOPPED /
1212 TASK_TRACED distinction, in which case it might be in a
1213 ptrace stop. Make sure it is in a ptrace stop; from there we
1214 can kill it, signal it, et cetera.
1216 First make sure there is a pending SIGSTOP. Since we are
1217 already attached, the process can not transition from stopped
1218 to running without a PTRACE_CONT; so we know this signal will
1219 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1220 probably already in the queue (unless this kernel is old
1221 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1222 is not an RT signal, it can only be queued once. */
1223 kill_lwp (pid
, SIGSTOP
);
1225 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1226 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1227 ptrace (PTRACE_CONT
, pid
, 0, 0);
1230 /* Make sure the initial process is stopped. The user-level threads
1231 layer might want to poke around in the inferior, and that won't
1232 work if things haven't stabilized yet. */
1233 new_pid
= my_waitpid (pid
, &status
, 0);
1234 if (new_pid
== -1 && errno
== ECHILD
)
1237 warning (_("%s is a cloned process"), target_pid_to_str (ptid
));
1239 /* Try again with __WCLONE to check cloned processes. */
1240 new_pid
= my_waitpid (pid
, &status
, __WCLONE
);
1244 gdb_assert (pid
== new_pid
&& WIFSTOPPED (status
));
1246 if (WSTOPSIG (status
) != SIGSTOP
)
1249 if (debug_linux_nat
)
1250 fprintf_unfiltered (gdb_stdlog
,
1251 "LNPAW: Received %s after attaching\n",
1252 status_to_str (status
));
1258 /* Attach to the LWP specified by PID. Return 0 if successful or -1
1259 if the new LWP could not be attached. */
1262 lin_lwp_attach_lwp (ptid_t ptid
)
1264 struct lwp_info
*lp
;
1267 gdb_assert (is_lwp (ptid
));
1269 block_child_signals (&prev_mask
);
1271 lp
= find_lwp_pid (ptid
);
1273 /* We assume that we're already attached to any LWP that has an id
1274 equal to the overall process id, and to any LWP that is already
1275 in our list of LWPs. If we're not seeing exit events from threads
1276 and we've had PID wraparound since we last tried to stop all threads,
1277 this assumption might be wrong; fortunately, this is very unlikely
1279 if (GET_LWP (ptid
) != GET_PID (ptid
) && lp
== NULL
)
1281 int status
, cloned
= 0, signalled
= 0;
1283 if (ptrace (PTRACE_ATTACH
, GET_LWP (ptid
), 0, 0) < 0)
1285 /* If we fail to attach to the thread, issue a warning,
1286 but continue. One way this can happen is if thread
1287 creation is interrupted; as of Linux kernel 2.6.19, a
1288 bug may place threads in the thread list and then fail
1290 warning (_("Can't attach %s: %s"), target_pid_to_str (ptid
),
1291 safe_strerror (errno
));
1292 restore_child_signals_mask (&prev_mask
);
1296 if (debug_linux_nat
)
1297 fprintf_unfiltered (gdb_stdlog
,
1298 "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
1299 target_pid_to_str (ptid
));
1301 status
= linux_nat_post_attach_wait (ptid
, 0, &cloned
, &signalled
);
1302 lp
= add_lwp (ptid
);
1304 lp
->cloned
= cloned
;
1305 lp
->signalled
= signalled
;
1306 if (WSTOPSIG (status
) != SIGSTOP
)
1309 lp
->status
= status
;
1312 target_post_attach (GET_LWP (lp
->ptid
));
1314 if (debug_linux_nat
)
1316 fprintf_unfiltered (gdb_stdlog
,
1317 "LLAL: waitpid %s received %s\n",
1318 target_pid_to_str (ptid
),
1319 status_to_str (status
));
1324 /* We assume that the LWP representing the original process is
1325 already stopped. Mark it as stopped in the data structure
1326 that the GNU/linux ptrace layer uses to keep track of
1327 threads. Note that this won't have already been done since
1328 the main thread will have, we assume, been stopped by an
1329 attach from a different layer. */
1331 lp
= add_lwp (ptid
);
1335 restore_child_signals_mask (&prev_mask
);
1340 linux_nat_create_inferior (struct target_ops
*ops
,
1341 char *exec_file
, char *allargs
, char **env
,
1344 #ifdef HAVE_PERSONALITY
1345 int personality_orig
= 0, personality_set
= 0;
1346 #endif /* HAVE_PERSONALITY */
1348 /* The fork_child mechanism is synchronous and calls target_wait, so
1349 we have to mask the async mode. */
1351 #ifdef HAVE_PERSONALITY
1352 if (disable_randomization
)
1355 personality_orig
= personality (0xffffffff);
1356 if (errno
== 0 && !(personality_orig
& ADDR_NO_RANDOMIZE
))
1358 personality_set
= 1;
1359 personality (personality_orig
| ADDR_NO_RANDOMIZE
);
1361 if (errno
!= 0 || (personality_set
1362 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE
)))
1363 warning (_("Error disabling address space randomization: %s"),
1364 safe_strerror (errno
));
1366 #endif /* HAVE_PERSONALITY */
1368 linux_ops
->to_create_inferior (ops
, exec_file
, allargs
, env
, from_tty
);
1370 #ifdef HAVE_PERSONALITY
1371 if (personality_set
)
1374 personality (personality_orig
);
1376 warning (_("Error restoring address space randomization: %s"),
1377 safe_strerror (errno
));
1379 #endif /* HAVE_PERSONALITY */
1383 linux_nat_attach (struct target_ops
*ops
, char *args
, int from_tty
)
1385 struct lwp_info
*lp
;
1389 linux_ops
->to_attach (ops
, args
, from_tty
);
1391 /* The ptrace base target adds the main thread with (pid,0,0)
1392 format. Decorate it with lwp info. */
1393 ptid
= BUILD_LWP (GET_PID (inferior_ptid
), GET_PID (inferior_ptid
));
1394 thread_change_ptid (inferior_ptid
, ptid
);
1396 /* Add the initial process as the first LWP to the list. */
1397 lp
= add_lwp (ptid
);
1399 status
= linux_nat_post_attach_wait (lp
->ptid
, 1, &lp
->cloned
,
1403 /* Save the wait status to report later. */
1405 if (debug_linux_nat
)
1406 fprintf_unfiltered (gdb_stdlog
,
1407 "LNA: waitpid %ld, saving status %s\n",
1408 (long) GET_PID (lp
->ptid
), status_to_str (status
));
1410 lp
->status
= status
;
1412 if (target_can_async_p ())
1413 target_async (inferior_event_handler
, 0);
1416 /* Get pending status of LP. */
1418 get_pending_status (struct lwp_info
*lp
, int *status
)
1420 struct target_waitstatus last
;
1423 get_last_target_status (&last_ptid
, &last
);
1425 /* If this lwp is the ptid that GDB is processing an event from, the
1426 signal will be in stop_signal. Otherwise, we may cache pending
1427 events in lp->status while trying to stop all threads (see
1428 stop_wait_callback). */
1434 enum target_signal signo
= TARGET_SIGNAL_0
;
1436 if (is_executing (lp
->ptid
))
1438 /* If the core thought this lwp was executing --- e.g., the
1439 executing property hasn't been updated yet, but the
1440 thread has been stopped with a stop_callback /
1441 stop_wait_callback sequence (see linux_nat_detach for
1442 example) --- we can only have pending events in the local
1444 signo
= target_signal_from_host (WSTOPSIG (lp
->status
));
1448 /* If the core knows the thread is not executing, then we
1449 have the last signal recorded in
1450 thread_info->stop_signal. */
1452 struct thread_info
*tp
= find_thread_pid (lp
->ptid
);
1453 signo
= tp
->stop_signal
;
1456 if (signo
!= TARGET_SIGNAL_0
1457 && !signal_pass_state (signo
))
1459 if (debug_linux_nat
)
1460 fprintf_unfiltered (gdb_stdlog
, "\
1461 GPT: lwp %s had signal %s, but it is in no pass state\n",
1462 target_pid_to_str (lp
->ptid
),
1463 target_signal_to_string (signo
));
1467 if (signo
!= TARGET_SIGNAL_0
)
1468 *status
= W_STOPCODE (target_signal_to_host (signo
));
1470 if (debug_linux_nat
)
1471 fprintf_unfiltered (gdb_stdlog
,
1472 "GPT: lwp %s as pending signal %s\n",
1473 target_pid_to_str (lp
->ptid
),
1474 target_signal_to_string (signo
));
1479 if (GET_LWP (lp
->ptid
) == GET_LWP (last_ptid
))
1481 struct thread_info
*tp
= find_thread_pid (lp
->ptid
);
1482 if (tp
->stop_signal
!= TARGET_SIGNAL_0
1483 && signal_pass_state (tp
->stop_signal
))
1484 *status
= W_STOPCODE (target_signal_to_host (tp
->stop_signal
));
1487 *status
= lp
->status
;
1494 detach_callback (struct lwp_info
*lp
, void *data
)
1496 gdb_assert (lp
->status
== 0 || WIFSTOPPED (lp
->status
));
1498 if (debug_linux_nat
&& lp
->status
)
1499 fprintf_unfiltered (gdb_stdlog
, "DC: Pending %s for %s on detach.\n",
1500 strsignal (WSTOPSIG (lp
->status
)),
1501 target_pid_to_str (lp
->ptid
));
1503 /* If there is a pending SIGSTOP, get rid of it. */
1506 if (debug_linux_nat
)
1507 fprintf_unfiltered (gdb_stdlog
,
1508 "DC: Sending SIGCONT to %s\n",
1509 target_pid_to_str (lp
->ptid
));
1511 kill_lwp (GET_LWP (lp
->ptid
), SIGCONT
);
1515 /* We don't actually detach from the LWP that has an id equal to the
1516 overall process id just yet. */
1517 if (GET_LWP (lp
->ptid
) != GET_PID (lp
->ptid
))
1521 /* Pass on any pending signal for this LWP. */
1522 get_pending_status (lp
, &status
);
1525 if (ptrace (PTRACE_DETACH
, GET_LWP (lp
->ptid
), 0,
1526 WSTOPSIG (status
)) < 0)
1527 error (_("Can't detach %s: %s"), target_pid_to_str (lp
->ptid
),
1528 safe_strerror (errno
));
1530 if (debug_linux_nat
)
1531 fprintf_unfiltered (gdb_stdlog
,
1532 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1533 target_pid_to_str (lp
->ptid
),
1534 strsignal (WSTOPSIG (status
)));
1536 delete_lwp (lp
->ptid
);
1543 linux_nat_detach (struct target_ops
*ops
, char *args
, int from_tty
)
1547 enum target_signal sig
;
1548 struct lwp_info
*main_lwp
;
1550 pid
= GET_PID (inferior_ptid
);
1552 if (target_can_async_p ())
1553 linux_nat_async (NULL
, 0);
1555 /* Stop all threads before detaching. ptrace requires that the
1556 thread is stopped to sucessfully detach. */
1557 iterate_over_lwps (pid_to_ptid (pid
), stop_callback
, NULL
);
1558 /* ... and wait until all of them have reported back that
1559 they're no longer running. */
1560 iterate_over_lwps (pid_to_ptid (pid
), stop_wait_callback
, NULL
);
1562 iterate_over_lwps (pid_to_ptid (pid
), detach_callback
, NULL
);
1564 /* Only the initial process should be left right now. */
1565 gdb_assert (num_lwps (GET_PID (inferior_ptid
)) == 1);
1567 main_lwp
= find_lwp_pid (pid_to_ptid (pid
));
1569 /* Pass on any pending signal for the last LWP. */
1570 if ((args
== NULL
|| *args
== '\0')
1571 && get_pending_status (main_lwp
, &status
) != -1
1572 && WIFSTOPPED (status
))
1574 /* Put the signal number in ARGS so that inf_ptrace_detach will
1575 pass it along with PTRACE_DETACH. */
1577 sprintf (args
, "%d", (int) WSTOPSIG (status
));
1578 fprintf_unfiltered (gdb_stdlog
,
1579 "LND: Sending signal %s to %s\n",
1581 target_pid_to_str (main_lwp
->ptid
));
1584 delete_lwp (main_lwp
->ptid
);
1586 if (forks_exist_p ())
1588 /* Multi-fork case. The current inferior_ptid is being detached
1589 from, but there are other viable forks to debug. Detach from
1590 the current fork, and context-switch to the first
1592 linux_fork_detach (args
, from_tty
);
1594 if (non_stop
&& target_can_async_p ())
1595 target_async (inferior_event_handler
, 0);
1598 linux_ops
->to_detach (ops
, args
, from_tty
);
1604 resume_callback (struct lwp_info
*lp
, void *data
)
1606 if (lp
->stopped
&& lp
->status
== 0)
1608 if (debug_linux_nat
)
1609 fprintf_unfiltered (gdb_stdlog
,
1610 "RC: PTRACE_CONT %s, 0, 0 (resuming sibling)\n",
1611 target_pid_to_str (lp
->ptid
));
1613 linux_ops
->to_resume (linux_ops
,
1614 pid_to_ptid (GET_LWP (lp
->ptid
)),
1615 0, TARGET_SIGNAL_0
);
1616 if (debug_linux_nat
)
1617 fprintf_unfiltered (gdb_stdlog
,
1618 "RC: PTRACE_CONT %s, 0, 0 (resume sibling)\n",
1619 target_pid_to_str (lp
->ptid
));
1622 memset (&lp
->siginfo
, 0, sizeof (lp
->siginfo
));
1624 else if (lp
->stopped
&& debug_linux_nat
)
1625 fprintf_unfiltered (gdb_stdlog
, "RC: Not resuming sibling %s (has pending)\n",
1626 target_pid_to_str (lp
->ptid
));
1627 else if (debug_linux_nat
)
1628 fprintf_unfiltered (gdb_stdlog
, "RC: Not resuming sibling %s (not stopped)\n",
1629 target_pid_to_str (lp
->ptid
));
1635 resume_clear_callback (struct lwp_info
*lp
, void *data
)
1642 resume_set_callback (struct lwp_info
*lp
, void *data
)
1649 linux_nat_resume (struct target_ops
*ops
,
1650 ptid_t ptid
, int step
, enum target_signal signo
)
1653 struct lwp_info
*lp
;
1656 if (debug_linux_nat
)
1657 fprintf_unfiltered (gdb_stdlog
,
1658 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1659 step
? "step" : "resume",
1660 target_pid_to_str (ptid
),
1661 signo
? strsignal (signo
) : "0",
1662 target_pid_to_str (inferior_ptid
));
1664 block_child_signals (&prev_mask
);
1666 /* A specific PTID means `step only this process id'. */
1667 resume_many
= (ptid_equal (minus_one_ptid
, ptid
)
1668 || ptid_is_pid (ptid
));
1672 /* Mark the lwps we're resuming as resumed. */
1673 iterate_over_lwps (minus_one_ptid
, resume_clear_callback
, NULL
);
1674 iterate_over_lwps (ptid
, resume_set_callback
, NULL
);
1677 iterate_over_lwps (minus_one_ptid
, resume_set_callback
, NULL
);
1679 /* See if it's the current inferior that should be handled
1682 lp
= find_lwp_pid (inferior_ptid
);
1684 lp
= find_lwp_pid (ptid
);
1685 gdb_assert (lp
!= NULL
);
1687 /* Remember if we're stepping. */
1690 /* If we have a pending wait status for this thread, there is no
1691 point in resuming the process. But first make sure that
1692 linux_nat_wait won't preemptively handle the event - we
1693 should never take this short-circuit if we are going to
1694 leave LP running, since we have skipped resuming all the
1695 other threads. This bit of code needs to be synchronized
1696 with linux_nat_wait. */
1698 if (lp
->status
&& WIFSTOPPED (lp
->status
))
1701 struct inferior
*inf
;
1703 inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
1705 saved_signo
= target_signal_from_host (WSTOPSIG (lp
->status
));
1707 /* Defer to common code if we're gaining control of the
1709 if (inf
->stop_soon
== NO_STOP_QUIETLY
1710 && signal_stop_state (saved_signo
) == 0
1711 && signal_print_state (saved_signo
) == 0
1712 && signal_pass_state (saved_signo
) == 1)
1714 if (debug_linux_nat
)
1715 fprintf_unfiltered (gdb_stdlog
,
1716 "LLR: Not short circuiting for ignored "
1717 "status 0x%x\n", lp
->status
);
1719 /* FIXME: What should we do if we are supposed to continue
1720 this thread with a signal? */
1721 gdb_assert (signo
== TARGET_SIGNAL_0
);
1722 signo
= saved_signo
;
1729 /* FIXME: What should we do if we are supposed to continue
1730 this thread with a signal? */
1731 gdb_assert (signo
== TARGET_SIGNAL_0
);
1733 if (debug_linux_nat
)
1734 fprintf_unfiltered (gdb_stdlog
,
1735 "LLR: Short circuiting for status 0x%x\n",
1738 restore_child_signals_mask (&prev_mask
);
1739 if (target_can_async_p ())
1741 target_async (inferior_event_handler
, 0);
1742 /* Tell the event loop we have something to process. */
1748 /* Mark LWP as not stopped to prevent it from being continued by
1753 iterate_over_lwps (ptid
, resume_callback
, NULL
);
1755 /* Convert to something the lower layer understands. */
1756 ptid
= pid_to_ptid (GET_LWP (lp
->ptid
));
1758 linux_ops
->to_resume (linux_ops
, ptid
, step
, signo
);
1759 memset (&lp
->siginfo
, 0, sizeof (lp
->siginfo
));
1761 if (debug_linux_nat
)
1762 fprintf_unfiltered (gdb_stdlog
,
1763 "LLR: %s %s, %s (resume event thread)\n",
1764 step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1765 target_pid_to_str (ptid
),
1766 signo
? strsignal (signo
) : "0");
1768 restore_child_signals_mask (&prev_mask
);
1769 if (target_can_async_p ())
1770 target_async (inferior_event_handler
, 0);
1773 /* Issue kill to specified lwp. */
1775 static int tkill_failed
;
1778 kill_lwp (int lwpid
, int signo
)
1782 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1783 fails, then we are not using nptl threads and we should be using kill. */
1785 #ifdef HAVE_TKILL_SYSCALL
1788 int ret
= syscall (__NR_tkill
, lwpid
, signo
);
1789 if (errno
!= ENOSYS
)
1796 return kill (lwpid
, signo
);
1799 /* Handle a GNU/Linux extended wait response. If we see a clone
1800 event, we need to add the new LWP to our list (and not report the
1801 trap to higher layers). This function returns non-zero if the
1802 event should be ignored and we should wait again. If STOPPING is
1803 true, the new LWP remains stopped, otherwise it is continued. */
1806 linux_handle_extended_wait (struct lwp_info
*lp
, int status
,
1809 int pid
= GET_LWP (lp
->ptid
);
1810 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1811 struct lwp_info
*new_lp
= NULL
;
1812 int event
= status
>> 16;
1814 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
1815 || event
== PTRACE_EVENT_CLONE
)
1817 unsigned long new_pid
;
1820 ptrace (PTRACE_GETEVENTMSG
, pid
, 0, &new_pid
);
1822 /* If we haven't already seen the new PID stop, wait for it now. */
1823 if (! pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
1825 /* The new child has a pending SIGSTOP. We can't affect it until it
1826 hits the SIGSTOP, but we're already attached. */
1827 ret
= my_waitpid (new_pid
, &status
,
1828 (event
== PTRACE_EVENT_CLONE
) ? __WCLONE
: 0);
1830 perror_with_name (_("waiting for new child"));
1831 else if (ret
!= new_pid
)
1832 internal_error (__FILE__
, __LINE__
,
1833 _("wait returned unexpected PID %d"), ret
);
1834 else if (!WIFSTOPPED (status
))
1835 internal_error (__FILE__
, __LINE__
,
1836 _("wait returned unexpected status 0x%x"), status
);
1839 ourstatus
->value
.related_pid
= ptid_build (new_pid
, new_pid
, 0);
1841 if (event
== PTRACE_EVENT_FORK
)
1842 ourstatus
->kind
= TARGET_WAITKIND_FORKED
;
1843 else if (event
== PTRACE_EVENT_VFORK
)
1844 ourstatus
->kind
= TARGET_WAITKIND_VFORKED
;
1847 struct cleanup
*old_chain
;
1849 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
1850 new_lp
= add_lwp (BUILD_LWP (new_pid
, GET_PID (lp
->ptid
)));
1852 new_lp
->stopped
= 1;
1854 if (WSTOPSIG (status
) != SIGSTOP
)
1856 /* This can happen if someone starts sending signals to
1857 the new thread before it gets a chance to run, which
1858 have a lower number than SIGSTOP (e.g. SIGUSR1).
1859 This is an unlikely case, and harder to handle for
1860 fork / vfork than for clone, so we do not try - but
1861 we handle it for clone events here. We'll send
1862 the other signal on to the thread below. */
1864 new_lp
->signalled
= 1;
1871 /* Add the new thread to GDB's lists as soon as possible
1874 1) the frontend doesn't have to wait for a stop to
1877 2) we tag it with the correct running state. */
1879 /* If the thread_db layer is active, let it know about
1880 this new thread, and add it to GDB's list. */
1881 if (!thread_db_attach_lwp (new_lp
->ptid
))
1883 /* We're not using thread_db. Add it to GDB's
1885 target_post_attach (GET_LWP (new_lp
->ptid
));
1886 add_thread (new_lp
->ptid
);
1891 set_running (new_lp
->ptid
, 1);
1892 set_executing (new_lp
->ptid
, 1);
1898 new_lp
->stopped
= 0;
1899 new_lp
->resumed
= 1;
1900 ptrace (PTRACE_CONT
, new_pid
, 0,
1901 status
? WSTOPSIG (status
) : 0);
1904 if (debug_linux_nat
)
1905 fprintf_unfiltered (gdb_stdlog
,
1906 "LHEW: Got clone event from LWP %ld, resuming\n",
1907 GET_LWP (lp
->ptid
));
1908 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
1916 if (event
== PTRACE_EVENT_EXEC
)
1918 ourstatus
->kind
= TARGET_WAITKIND_EXECD
;
1919 ourstatus
->value
.execd_pathname
1920 = xstrdup (linux_child_pid_to_exec_file (pid
));
1922 if (linux_parent_pid
)
1924 detach_breakpoints (linux_parent_pid
);
1925 ptrace (PTRACE_DETACH
, linux_parent_pid
, 0, 0);
1927 linux_parent_pid
= 0;
1930 /* At this point, all inserted breakpoints are gone. Doing this
1931 as soon as we detect an exec prevents the badness of deleting
1932 a breakpoint writing the current "shadow contents" to lift
1933 the bp. That shadow is NOT valid after an exec.
1935 Note that we have to do this after the detach_breakpoints
1936 call above, otherwise breakpoints wouldn't be lifted from the
1937 parent on a vfork, because detach_breakpoints would think
1938 that breakpoints are not inserted. */
1939 mark_breakpoints_out ();
1943 internal_error (__FILE__
, __LINE__
,
1944 _("unknown ptrace event %d"), event
);
1947 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
1951 wait_lwp (struct lwp_info
*lp
)
1955 int thread_dead
= 0;
1957 gdb_assert (!lp
->stopped
);
1958 gdb_assert (lp
->status
== 0);
1960 pid
= my_waitpid (GET_LWP (lp
->ptid
), &status
, 0);
1961 if (pid
== -1 && errno
== ECHILD
)
1963 pid
= my_waitpid (GET_LWP (lp
->ptid
), &status
, __WCLONE
);
1964 if (pid
== -1 && errno
== ECHILD
)
1966 /* The thread has previously exited. We need to delete it
1967 now because, for some vendor 2.4 kernels with NPTL
1968 support backported, there won't be an exit event unless
1969 it is the main thread. 2.6 kernels will report an exit
1970 event for each thread that exits, as expected. */
1972 if (debug_linux_nat
)
1973 fprintf_unfiltered (gdb_stdlog
, "WL: %s vanished.\n",
1974 target_pid_to_str (lp
->ptid
));
1980 gdb_assert (pid
== GET_LWP (lp
->ptid
));
1982 if (debug_linux_nat
)
1984 fprintf_unfiltered (gdb_stdlog
,
1985 "WL: waitpid %s received %s\n",
1986 target_pid_to_str (lp
->ptid
),
1987 status_to_str (status
));
1991 /* Check if the thread has exited. */
1992 if (WIFEXITED (status
) || WIFSIGNALED (status
))
1995 if (debug_linux_nat
)
1996 fprintf_unfiltered (gdb_stdlog
, "WL: %s exited.\n",
1997 target_pid_to_str (lp
->ptid
));
2006 gdb_assert (WIFSTOPPED (status
));
2008 /* Handle GNU/Linux's extended waitstatus for trace events. */
2009 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 != 0)
2011 if (debug_linux_nat
)
2012 fprintf_unfiltered (gdb_stdlog
,
2013 "WL: Handling extended status 0x%06x\n",
2015 if (linux_handle_extended_wait (lp
, status
, 1))
2016 return wait_lwp (lp
);
2022 /* Save the most recent siginfo for LP. This is currently only called
2023 for SIGTRAP; some ports use the si_addr field for
2024 target_stopped_data_address. In the future, it may also be used to
2025 restore the siginfo of requeued signals. */
2028 save_siginfo (struct lwp_info
*lp
)
2031 ptrace (PTRACE_GETSIGINFO
, GET_LWP (lp
->ptid
),
2032 (PTRACE_TYPE_ARG3
) 0, &lp
->siginfo
);
2035 memset (&lp
->siginfo
, 0, sizeof (lp
->siginfo
));
2038 /* Send a SIGSTOP to LP. */
2041 stop_callback (struct lwp_info
*lp
, void *data
)
2043 if (!lp
->stopped
&& !lp
->signalled
)
2047 if (debug_linux_nat
)
2049 fprintf_unfiltered (gdb_stdlog
,
2050 "SC: kill %s **<SIGSTOP>**\n",
2051 target_pid_to_str (lp
->ptid
));
2054 ret
= kill_lwp (GET_LWP (lp
->ptid
), SIGSTOP
);
2055 if (debug_linux_nat
)
2057 fprintf_unfiltered (gdb_stdlog
,
2058 "SC: lwp kill %d %s\n",
2060 errno
? safe_strerror (errno
) : "ERRNO-OK");
2064 gdb_assert (lp
->status
== 0);
2070 /* Return non-zero if LWP PID has a pending SIGINT. */
2073 linux_nat_has_pending_sigint (int pid
)
2075 sigset_t pending
, blocked
, ignored
;
2078 linux_proc_pending_signals (pid
, &pending
, &blocked
, &ignored
);
2080 if (sigismember (&pending
, SIGINT
)
2081 && !sigismember (&ignored
, SIGINT
))
2087 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2090 set_ignore_sigint (struct lwp_info
*lp
, void *data
)
2092 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2093 flag to consume the next one. */
2094 if (lp
->stopped
&& lp
->status
!= 0 && WIFSTOPPED (lp
->status
)
2095 && WSTOPSIG (lp
->status
) == SIGINT
)
2098 lp
->ignore_sigint
= 1;
2103 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2104 This function is called after we know the LWP has stopped; if the LWP
2105 stopped before the expected SIGINT was delivered, then it will never have
2106 arrived. Also, if the signal was delivered to a shared queue and consumed
2107 by a different thread, it will never be delivered to this LWP. */
2110 maybe_clear_ignore_sigint (struct lwp_info
*lp
)
2112 if (!lp
->ignore_sigint
)
2115 if (!linux_nat_has_pending_sigint (GET_LWP (lp
->ptid
)))
2117 if (debug_linux_nat
)
2118 fprintf_unfiltered (gdb_stdlog
,
2119 "MCIS: Clearing bogus flag for %s\n",
2120 target_pid_to_str (lp
->ptid
));
2121 lp
->ignore_sigint
= 0;
2125 /* Wait until LP is stopped. */
2128 stop_wait_callback (struct lwp_info
*lp
, void *data
)
2134 status
= wait_lwp (lp
);
2138 if (lp
->ignore_sigint
&& WIFSTOPPED (status
)
2139 && WSTOPSIG (status
) == SIGINT
)
2141 lp
->ignore_sigint
= 0;
2144 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2145 if (debug_linux_nat
)
2146 fprintf_unfiltered (gdb_stdlog
,
2147 "PTRACE_CONT %s, 0, 0 (%s) (discarding SIGINT)\n",
2148 target_pid_to_str (lp
->ptid
),
2149 errno
? safe_strerror (errno
) : "OK");
2151 return stop_wait_callback (lp
, NULL
);
2154 maybe_clear_ignore_sigint (lp
);
2156 if (WSTOPSIG (status
) != SIGSTOP
)
2158 if (WSTOPSIG (status
) == SIGTRAP
)
2160 /* If a LWP other than the LWP that we're reporting an
2161 event for has hit a GDB breakpoint (as opposed to
2162 some random trap signal), then just arrange for it to
2163 hit it again later. We don't keep the SIGTRAP status
2164 and don't forward the SIGTRAP signal to the LWP. We
2165 will handle the current event, eventually we will
2166 resume all LWPs, and this one will get its breakpoint
2169 If we do not do this, then we run the risk that the
2170 user will delete or disable the breakpoint, but the
2171 thread will have already tripped on it. */
2173 /* Save the trap's siginfo in case we need it later. */
2176 /* Now resume this LWP and get the SIGSTOP event. */
2178 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2179 if (debug_linux_nat
)
2181 fprintf_unfiltered (gdb_stdlog
,
2182 "PTRACE_CONT %s, 0, 0 (%s)\n",
2183 target_pid_to_str (lp
->ptid
),
2184 errno
? safe_strerror (errno
) : "OK");
2186 fprintf_unfiltered (gdb_stdlog
,
2187 "SWC: Candidate SIGTRAP event in %s\n",
2188 target_pid_to_str (lp
->ptid
));
2190 /* Hold this event/waitstatus while we check to see if
2191 there are any more (we still want to get that SIGSTOP). */
2192 stop_wait_callback (lp
, NULL
);
2194 /* Hold the SIGTRAP for handling by linux_nat_wait. If
2195 there's another event, throw it back into the
2199 if (debug_linux_nat
)
2200 fprintf_unfiltered (gdb_stdlog
,
2201 "SWC: kill %s, %s\n",
2202 target_pid_to_str (lp
->ptid
),
2203 status_to_str ((int) status
));
2204 kill_lwp (GET_LWP (lp
->ptid
), WSTOPSIG (lp
->status
));
2207 /* Save the sigtrap event. */
2208 lp
->status
= status
;
2213 /* The thread was stopped with a signal other than
2214 SIGSTOP, and didn't accidentally trip a breakpoint. */
2216 if (debug_linux_nat
)
2218 fprintf_unfiltered (gdb_stdlog
,
2219 "SWC: Pending event %s in %s\n",
2220 status_to_str ((int) status
),
2221 target_pid_to_str (lp
->ptid
));
2223 /* Now resume this LWP and get the SIGSTOP event. */
2225 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2226 if (debug_linux_nat
)
2227 fprintf_unfiltered (gdb_stdlog
,
2228 "SWC: PTRACE_CONT %s, 0, 0 (%s)\n",
2229 target_pid_to_str (lp
->ptid
),
2230 errno
? safe_strerror (errno
) : "OK");
2232 /* Hold this event/waitstatus while we check to see if
2233 there are any more (we still want to get that SIGSTOP). */
2234 stop_wait_callback (lp
, NULL
);
2236 /* If the lp->status field is still empty, use it to
2237 hold this event. If not, then this event must be
2238 returned to the event queue of the LWP. */
2241 if (debug_linux_nat
)
2243 fprintf_unfiltered (gdb_stdlog
,
2244 "SWC: kill %s, %s\n",
2245 target_pid_to_str (lp
->ptid
),
2246 status_to_str ((int) status
));
2248 kill_lwp (GET_LWP (lp
->ptid
), WSTOPSIG (status
));
2251 lp
->status
= status
;
2257 /* We caught the SIGSTOP that we intended to catch, so
2258 there's no SIGSTOP pending. */
2267 /* Return non-zero if LP has a wait status pending. */
2270 status_callback (struct lwp_info
*lp
, void *data
)
2272 /* Only report a pending wait status if we pretend that this has
2273 indeed been resumed. */
2274 /* We check for lp->waitstatus in addition to lp->status, because we
2275 can have pending process exits recorded in lp->waitstatus, and
2276 W_EXITCODE(0,0) == 0. */
2277 return ((lp
->status
!= 0
2278 || lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
2282 /* Return non-zero if LP isn't stopped. */
2285 running_callback (struct lwp_info
*lp
, void *data
)
2287 return (lp
->stopped
== 0 || (lp
->status
!= 0 && lp
->resumed
));
2290 /* Count the LWP's that have had events. */
2293 count_events_callback (struct lwp_info
*lp
, void *data
)
2297 gdb_assert (count
!= NULL
);
2299 /* Count only resumed LWPs that have a SIGTRAP event pending. */
2300 if (lp
->status
!= 0 && lp
->resumed
2301 && WIFSTOPPED (lp
->status
) && WSTOPSIG (lp
->status
) == SIGTRAP
)
2307 /* Select the LWP (if any) that is currently being single-stepped. */
2310 select_singlestep_lwp_callback (struct lwp_info
*lp
, void *data
)
2312 if (lp
->step
&& lp
->status
!= 0)
2318 /* Select the Nth LWP that has had a SIGTRAP event. */
2321 select_event_lwp_callback (struct lwp_info
*lp
, void *data
)
2323 int *selector
= data
;
2325 gdb_assert (selector
!= NULL
);
2327 /* Select only resumed LWPs that have a SIGTRAP event pending. */
2328 if (lp
->status
!= 0 && lp
->resumed
2329 && WIFSTOPPED (lp
->status
) && WSTOPSIG (lp
->status
) == SIGTRAP
)
2330 if ((*selector
)-- == 0)
2337 cancel_breakpoint (struct lwp_info
*lp
)
2339 /* Arrange for a breakpoint to be hit again later. We don't keep
2340 the SIGTRAP status and don't forward the SIGTRAP signal to the
2341 LWP. We will handle the current event, eventually we will resume
2342 this LWP, and this breakpoint will trap again.
2344 If we do not do this, then we run the risk that the user will
2345 delete or disable the breakpoint, but the LWP will have already
2348 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
2349 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
2352 pc
= regcache_read_pc (regcache
) - gdbarch_decr_pc_after_break (gdbarch
);
2353 if (breakpoint_inserted_here_p (pc
))
2355 if (debug_linux_nat
)
2356 fprintf_unfiltered (gdb_stdlog
,
2357 "CB: Push back breakpoint for %s\n",
2358 target_pid_to_str (lp
->ptid
));
2360 /* Back up the PC if necessary. */
2361 if (gdbarch_decr_pc_after_break (gdbarch
))
2362 regcache_write_pc (regcache
, pc
);
2370 cancel_breakpoints_callback (struct lwp_info
*lp
, void *data
)
2372 struct lwp_info
*event_lp
= data
;
2374 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
2378 /* If a LWP other than the LWP that we're reporting an event for has
2379 hit a GDB breakpoint (as opposed to some random trap signal),
2380 then just arrange for it to hit it again later. We don't keep
2381 the SIGTRAP status and don't forward the SIGTRAP signal to the
2382 LWP. We will handle the current event, eventually we will resume
2383 all LWPs, and this one will get its breakpoint trap again.
2385 If we do not do this, then we run the risk that the user will
2386 delete or disable the breakpoint, but the LWP will have already
2390 && WIFSTOPPED (lp
->status
) && WSTOPSIG (lp
->status
) == SIGTRAP
2391 && cancel_breakpoint (lp
))
2392 /* Throw away the SIGTRAP. */
2398 /* Select one LWP out of those that have events pending. */
2401 select_event_lwp (ptid_t filter
, struct lwp_info
**orig_lp
, int *status
)
2404 int random_selector
;
2405 struct lwp_info
*event_lp
;
2407 /* Record the wait status for the original LWP. */
2408 (*orig_lp
)->status
= *status
;
2410 /* Give preference to any LWP that is being single-stepped. */
2411 event_lp
= iterate_over_lwps (filter
,
2412 select_singlestep_lwp_callback
, NULL
);
2413 if (event_lp
!= NULL
)
2415 if (debug_linux_nat
)
2416 fprintf_unfiltered (gdb_stdlog
,
2417 "SEL: Select single-step %s\n",
2418 target_pid_to_str (event_lp
->ptid
));
2422 /* No single-stepping LWP. Select one at random, out of those
2423 which have had SIGTRAP events. */
2425 /* First see how many SIGTRAP events we have. */
2426 iterate_over_lwps (filter
, count_events_callback
, &num_events
);
2428 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
2429 random_selector
= (int)
2430 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
2432 if (debug_linux_nat
&& num_events
> 1)
2433 fprintf_unfiltered (gdb_stdlog
,
2434 "SEL: Found %d SIGTRAP events, selecting #%d\n",
2435 num_events
, random_selector
);
2437 event_lp
= iterate_over_lwps (filter
,
2438 select_event_lwp_callback
,
2442 if (event_lp
!= NULL
)
2444 /* Switch the event LWP. */
2445 *orig_lp
= event_lp
;
2446 *status
= event_lp
->status
;
2449 /* Flush the wait status for the event LWP. */
2450 (*orig_lp
)->status
= 0;
2453 /* Return non-zero if LP has been resumed. */
2456 resumed_callback (struct lwp_info
*lp
, void *data
)
2461 /* Stop an active thread, verify it still exists, then resume it. */
2464 stop_and_resume_callback (struct lwp_info
*lp
, void *data
)
2466 struct lwp_info
*ptr
;
2468 if (!lp
->stopped
&& !lp
->signalled
)
2470 stop_callback (lp
, NULL
);
2471 stop_wait_callback (lp
, NULL
);
2472 /* Resume if the lwp still exists. */
2473 for (ptr
= lwp_list
; ptr
; ptr
= ptr
->next
)
2476 resume_callback (lp
, NULL
);
2477 resume_set_callback (lp
, NULL
);
2483 /* Check if we should go on and pass this event to common code.
2484 Return the affected lwp if we are, or NULL otherwise. */
2485 static struct lwp_info
*
2486 linux_nat_filter_event (int lwpid
, int status
, int options
)
2488 struct lwp_info
*lp
;
2490 lp
= find_lwp_pid (pid_to_ptid (lwpid
));
2492 /* Check for stop events reported by a process we didn't already
2493 know about - anything not already in our LWP list.
2495 If we're expecting to receive stopped processes after
2496 fork, vfork, and clone events, then we'll just add the
2497 new one to our list and go back to waiting for the event
2498 to be reported - the stopped process might be returned
2499 from waitpid before or after the event is. */
2500 if (WIFSTOPPED (status
) && !lp
)
2502 linux_record_stopped_pid (lwpid
, status
);
2506 /* Make sure we don't report an event for the exit of an LWP not in
2507 our list, i.e. not part of the current process. This can happen
2508 if we detach from a program we original forked and then it
2510 if (!WIFSTOPPED (status
) && !lp
)
2513 /* NOTE drow/2003-06-17: This code seems to be meant for debugging
2514 CLONE_PTRACE processes which do not use the thread library -
2515 otherwise we wouldn't find the new LWP this way. That doesn't
2516 currently work, and the following code is currently unreachable
2517 due to the two blocks above. If it's fixed some day, this code
2518 should be broken out into a function so that we can also pick up
2519 LWPs from the new interface. */
2522 lp
= add_lwp (BUILD_LWP (lwpid
, GET_PID (inferior_ptid
)));
2523 if (options
& __WCLONE
)
2526 gdb_assert (WIFSTOPPED (status
)
2527 && WSTOPSIG (status
) == SIGSTOP
);
2530 if (!in_thread_list (inferior_ptid
))
2532 inferior_ptid
= BUILD_LWP (GET_PID (inferior_ptid
),
2533 GET_PID (inferior_ptid
));
2534 add_thread (inferior_ptid
);
2537 add_thread (lp
->ptid
);
2540 /* Save the trap's siginfo in case we need it later. */
2541 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
)
2544 /* Handle GNU/Linux's extended waitstatus for trace events. */
2545 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 != 0)
2547 if (debug_linux_nat
)
2548 fprintf_unfiltered (gdb_stdlog
,
2549 "LLW: Handling extended status 0x%06x\n",
2551 if (linux_handle_extended_wait (lp
, status
, 0))
2555 /* Check if the thread has exited. */
2556 if ((WIFEXITED (status
) || WIFSIGNALED (status
))
2557 && num_lwps (GET_PID (lp
->ptid
)) > 1)
2559 /* If this is the main thread, we must stop all threads and verify
2560 if they are still alive. This is because in the nptl thread model
2561 on Linux 2.4, there is no signal issued for exiting LWPs
2562 other than the main thread. We only get the main thread exit
2563 signal once all child threads have already exited. If we
2564 stop all the threads and use the stop_wait_callback to check
2565 if they have exited we can determine whether this signal
2566 should be ignored or whether it means the end of the debugged
2567 application, regardless of which threading model is being
2569 if (GET_PID (lp
->ptid
) == GET_LWP (lp
->ptid
))
2572 iterate_over_lwps (pid_to_ptid (GET_PID (lp
->ptid
)),
2573 stop_and_resume_callback
, NULL
);
2576 if (debug_linux_nat
)
2577 fprintf_unfiltered (gdb_stdlog
,
2578 "LLW: %s exited.\n",
2579 target_pid_to_str (lp
->ptid
));
2581 if (num_lwps (GET_PID (lp
->ptid
)) > 1)
2583 /* If there is at least one more LWP, then the exit signal
2584 was not the end of the debugged application and should be
2591 /* Check if the current LWP has previously exited. In the nptl
2592 thread model, LWPs other than the main thread do not issue
2593 signals when they exit so we must check whenever the thread has
2594 stopped. A similar check is made in stop_wait_callback(). */
2595 if (num_lwps (GET_PID (lp
->ptid
)) > 1 && !linux_thread_alive (lp
->ptid
))
2597 ptid_t ptid
= pid_to_ptid (GET_PID (lp
->ptid
));
2599 if (debug_linux_nat
)
2600 fprintf_unfiltered (gdb_stdlog
,
2601 "LLW: %s exited.\n",
2602 target_pid_to_str (lp
->ptid
));
2606 /* Make sure there is at least one thread running. */
2607 gdb_assert (iterate_over_lwps (ptid
, running_callback
, NULL
));
2609 /* Discard the event. */
2613 /* Make sure we don't report a SIGSTOP that we sent ourselves in
2614 an attempt to stop an LWP. */
2616 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGSTOP
)
2618 if (debug_linux_nat
)
2619 fprintf_unfiltered (gdb_stdlog
,
2620 "LLW: Delayed SIGSTOP caught for %s.\n",
2621 target_pid_to_str (lp
->ptid
));
2623 /* This is a delayed SIGSTOP. */
2626 registers_changed ();
2628 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
2629 lp
->step
, TARGET_SIGNAL_0
);
2630 if (debug_linux_nat
)
2631 fprintf_unfiltered (gdb_stdlog
,
2632 "LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
2634 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2635 target_pid_to_str (lp
->ptid
));
2638 gdb_assert (lp
->resumed
);
2640 /* Discard the event. */
2644 /* Make sure we don't report a SIGINT that we have already displayed
2645 for another thread. */
2646 if (lp
->ignore_sigint
2647 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGINT
)
2649 if (debug_linux_nat
)
2650 fprintf_unfiltered (gdb_stdlog
,
2651 "LLW: Delayed SIGINT caught for %s.\n",
2652 target_pid_to_str (lp
->ptid
));
2654 /* This is a delayed SIGINT. */
2655 lp
->ignore_sigint
= 0;
2657 registers_changed ();
2658 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
2659 lp
->step
, TARGET_SIGNAL_0
);
2660 if (debug_linux_nat
)
2661 fprintf_unfiltered (gdb_stdlog
,
2662 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
2664 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2665 target_pid_to_str (lp
->ptid
));
2668 gdb_assert (lp
->resumed
);
2670 /* Discard the event. */
2674 /* An interesting event. */
2680 linux_nat_wait_1 (struct target_ops
*ops
,
2681 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
2684 static sigset_t prev_mask
;
2685 struct lwp_info
*lp
= NULL
;
2690 if (debug_linux_nat_async
)
2691 fprintf_unfiltered (gdb_stdlog
, "LLW: enter\n");
2693 /* The first time we get here after starting a new inferior, we may
2694 not have added it to the LWP list yet - this is the earliest
2695 moment at which we know its PID. */
2696 if (ptid_is_pid (inferior_ptid
))
2698 /* Upgrade the main thread's ptid. */
2699 thread_change_ptid (inferior_ptid
,
2700 BUILD_LWP (GET_PID (inferior_ptid
),
2701 GET_PID (inferior_ptid
)));
2703 lp
= add_lwp (inferior_ptid
);
2707 /* Make sure SIGCHLD is blocked. */
2708 block_child_signals (&prev_mask
);
2710 if (ptid_equal (ptid
, minus_one_ptid
))
2712 else if (ptid_is_pid (ptid
))
2713 /* A request to wait for a specific tgid. This is not possible
2714 with waitpid, so instead, we wait for any child, and leave
2715 children we're not interested in right now with a pending
2716 status to report later. */
2719 pid
= GET_LWP (ptid
);
2725 /* Make sure there is at least one LWP that has been resumed. */
2726 gdb_assert (iterate_over_lwps (ptid
, resumed_callback
, NULL
));
2728 /* First check if there is a LWP with a wait status pending. */
2731 /* Any LWP that's been resumed will do. */
2732 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
2735 status
= lp
->status
;
2738 if (debug_linux_nat
&& status
)
2739 fprintf_unfiltered (gdb_stdlog
,
2740 "LLW: Using pending wait status %s for %s.\n",
2741 status_to_str (status
),
2742 target_pid_to_str (lp
->ptid
));
2745 /* But if we don't find one, we'll have to wait, and check both
2746 cloned and uncloned processes. We start with the cloned
2748 options
= __WCLONE
| WNOHANG
;
2750 else if (is_lwp (ptid
))
2752 if (debug_linux_nat
)
2753 fprintf_unfiltered (gdb_stdlog
,
2754 "LLW: Waiting for specific LWP %s.\n",
2755 target_pid_to_str (ptid
));
2757 /* We have a specific LWP to check. */
2758 lp
= find_lwp_pid (ptid
);
2760 status
= lp
->status
;
2763 if (debug_linux_nat
&& status
)
2764 fprintf_unfiltered (gdb_stdlog
,
2765 "LLW: Using pending wait status %s for %s.\n",
2766 status_to_str (status
),
2767 target_pid_to_str (lp
->ptid
));
2769 /* If we have to wait, take into account whether PID is a cloned
2770 process or not. And we have to convert it to something that
2771 the layer beneath us can understand. */
2772 options
= lp
->cloned
? __WCLONE
: 0;
2773 pid
= GET_LWP (ptid
);
2775 /* We check for lp->waitstatus in addition to lp->status,
2776 because we can have pending process exits recorded in
2777 lp->status and W_EXITCODE(0,0) == 0. We should probably have
2778 an additional lp->status_p flag. */
2779 if (status
== 0 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
2783 if (lp
&& lp
->signalled
)
2785 /* A pending SIGSTOP may interfere with the normal stream of
2786 events. In a typical case where interference is a problem,
2787 we have a SIGSTOP signal pending for LWP A while
2788 single-stepping it, encounter an event in LWP B, and take the
2789 pending SIGSTOP while trying to stop LWP A. After processing
2790 the event in LWP B, LWP A is continued, and we'll never see
2791 the SIGTRAP associated with the last time we were
2792 single-stepping LWP A. */
2794 /* Resume the thread. It should halt immediately returning the
2796 registers_changed ();
2797 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
2798 lp
->step
, TARGET_SIGNAL_0
);
2799 if (debug_linux_nat
)
2800 fprintf_unfiltered (gdb_stdlog
,
2801 "LLW: %s %s, 0, 0 (expect SIGSTOP)\n",
2802 lp
->step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2803 target_pid_to_str (lp
->ptid
));
2805 gdb_assert (lp
->resumed
);
2807 /* This should catch the pending SIGSTOP. */
2808 stop_wait_callback (lp
, NULL
);
2811 if (!target_can_async_p ())
2813 /* Causes SIGINT to be passed on to the attached process. */
2817 /* Translate generic target_wait options into waitpid options. */
2818 if (target_options
& TARGET_WNOHANG
)
2825 lwpid
= my_waitpid (pid
, &status
, options
);
2829 gdb_assert (pid
== -1 || lwpid
== pid
);
2831 if (debug_linux_nat
)
2833 fprintf_unfiltered (gdb_stdlog
,
2834 "LLW: waitpid %ld received %s\n",
2835 (long) lwpid
, status_to_str (status
));
2838 lp
= linux_nat_filter_event (lwpid
, status
, options
);
2841 && ptid_is_pid (ptid
)
2842 && ptid_get_pid (lp
->ptid
) != ptid_get_pid (ptid
))
2844 if (debug_linux_nat
)
2845 fprintf (stderr
, "LWP %ld got an event %06x, leaving pending.\n",
2846 ptid_get_lwp (lp
->ptid
), status
);
2848 if (WIFSTOPPED (status
))
2850 if (WSTOPSIG (status
) != SIGSTOP
)
2852 lp
->status
= status
;
2854 stop_callback (lp
, NULL
);
2856 /* Resume in order to collect the sigstop. */
2857 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2859 stop_wait_callback (lp
, NULL
);
2867 else if (WIFEXITED (status
) || WIFSIGNALED (status
))
2869 if (debug_linux_nat
)
2870 fprintf (stderr
, "Process %ld exited while stopping LWPs\n",
2871 ptid_get_lwp (lp
->ptid
));
2873 /* This was the last lwp in the process. Since
2874 events are serialized to GDB core, and we can't
2875 report this one right now, but GDB core and the
2876 other target layers will want to be notified
2877 about the exit code/signal, leave the status
2878 pending for the next time we're able to report
2880 lp
->status
= status
;
2882 /* Prevent trying to stop this thread again. We'll
2883 never try to resume it because it has a pending
2887 /* Dead LWP's aren't expected to reported a pending
2891 /* Store the pending event in the waitstatus as
2892 well, because W_EXITCODE(0,0) == 0. */
2893 store_waitstatus (&lp
->waitstatus
, status
);
2907 /* waitpid did return something. Restart over. */
2908 options
|= __WCLONE
;
2916 /* Alternate between checking cloned and uncloned processes. */
2917 options
^= __WCLONE
;
2919 /* And every time we have checked both:
2920 In async mode, return to event loop;
2921 In sync mode, suspend waiting for a SIGCHLD signal. */
2922 if (options
& __WCLONE
)
2924 if (target_options
& TARGET_WNOHANG
)
2926 /* No interesting event. */
2927 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2929 if (debug_linux_nat_async
)
2930 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (ignore)\n");
2932 restore_child_signals_mask (&prev_mask
);
2933 return minus_one_ptid
;
2936 sigsuspend (&suspend_mask
);
2940 /* We shouldn't end up here unless we want to try again. */
2941 gdb_assert (lp
== NULL
);
2944 if (!target_can_async_p ())
2945 clear_sigint_trap ();
2949 /* Don't report signals that GDB isn't interested in, such as
2950 signals that are neither printed nor stopped upon. Stopping all
2951 threads can be a bit time-consuming so if we want decent
2952 performance with heavily multi-threaded programs, especially when
2953 they're using a high frequency timer, we'd better avoid it if we
2956 if (WIFSTOPPED (status
))
2958 int signo
= target_signal_from_host (WSTOPSIG (status
));
2959 struct inferior
*inf
;
2961 inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
2964 /* Defer to common code if we get a signal while
2965 single-stepping, since that may need special care, e.g. to
2966 skip the signal handler, or, if we're gaining control of the
2969 && inf
->stop_soon
== NO_STOP_QUIETLY
2970 && signal_stop_state (signo
) == 0
2971 && signal_print_state (signo
) == 0
2972 && signal_pass_state (signo
) == 1)
2974 /* FIMXE: kettenis/2001-06-06: Should we resume all threads
2975 here? It is not clear we should. GDB may not expect
2976 other threads to run. On the other hand, not resuming
2977 newly attached threads may cause an unwanted delay in
2978 getting them running. */
2979 registers_changed ();
2980 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
2982 if (debug_linux_nat
)
2983 fprintf_unfiltered (gdb_stdlog
,
2984 "LLW: %s %s, %s (preempt 'handle')\n",
2986 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2987 target_pid_to_str (lp
->ptid
),
2988 signo
? strsignal (signo
) : "0");
2995 /* Only do the below in all-stop, as we currently use SIGINT
2996 to implement target_stop (see linux_nat_stop) in
2998 if (signo
== TARGET_SIGNAL_INT
&& signal_pass_state (signo
) == 0)
3000 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3001 forwarded to the entire process group, that is, all LWPs
3002 will receive it - unless they're using CLONE_THREAD to
3003 share signals. Since we only want to report it once, we
3004 mark it as ignored for all LWPs except this one. */
3005 iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid
)),
3006 set_ignore_sigint
, NULL
);
3007 lp
->ignore_sigint
= 0;
3010 maybe_clear_ignore_sigint (lp
);
3014 /* This LWP is stopped now. */
3017 if (debug_linux_nat
)
3018 fprintf_unfiltered (gdb_stdlog
, "LLW: Candidate event %s in %s.\n",
3019 status_to_str (status
), target_pid_to_str (lp
->ptid
));
3023 /* Now stop all other LWP's ... */
3024 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
3026 /* ... and wait until all of them have reported back that
3027 they're no longer running. */
3028 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
3030 /* If we're not waiting for a specific LWP, choose an event LWP
3031 from among those that have had events. Giving equal priority
3032 to all LWPs that have had events helps prevent
3035 select_event_lwp (ptid
, &lp
, &status
);
3038 /* Now that we've selected our final event LWP, cancel any
3039 breakpoints in other LWPs that have hit a GDB breakpoint. See
3040 the comment in cancel_breakpoints_callback to find out why. */
3041 iterate_over_lwps (minus_one_ptid
, cancel_breakpoints_callback
, lp
);
3043 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
)
3045 if (debug_linux_nat
)
3046 fprintf_unfiltered (gdb_stdlog
,
3047 "LLW: trap ptid is %s.\n",
3048 target_pid_to_str (lp
->ptid
));
3051 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3053 *ourstatus
= lp
->waitstatus
;
3054 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3057 store_waitstatus (ourstatus
, status
);
3059 if (debug_linux_nat_async
)
3060 fprintf_unfiltered (gdb_stdlog
, "LLW: exit\n");
3062 restore_child_signals_mask (&prev_mask
);
3067 linux_nat_wait (struct target_ops
*ops
,
3068 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3073 if (debug_linux_nat
)
3074 fprintf_unfiltered (gdb_stdlog
, "linux_nat_wait: [%s]\n", target_pid_to_str (ptid
));
3076 /* Flush the async file first. */
3077 if (target_can_async_p ())
3078 async_file_flush ();
3080 event_ptid
= linux_nat_wait_1 (ops
, ptid
, ourstatus
, target_options
);
3082 /* If we requested any event, and something came out, assume there
3083 may be more. If we requested a specific lwp or process, also
3084 assume there may be more. */
3085 if (target_can_async_p ()
3086 && (ourstatus
->kind
!= TARGET_WAITKIND_IGNORE
3087 || !ptid_equal (ptid
, minus_one_ptid
)))
3090 /* Get ready for the next event. */
3091 if (target_can_async_p ())
3092 target_async (inferior_event_handler
, 0);
3098 kill_callback (struct lwp_info
*lp
, void *data
)
3101 ptrace (PTRACE_KILL
, GET_LWP (lp
->ptid
), 0, 0);
3102 if (debug_linux_nat
)
3103 fprintf_unfiltered (gdb_stdlog
,
3104 "KC: PTRACE_KILL %s, 0, 0 (%s)\n",
3105 target_pid_to_str (lp
->ptid
),
3106 errno
? safe_strerror (errno
) : "OK");
3112 kill_wait_callback (struct lwp_info
*lp
, void *data
)
3116 /* We must make sure that there are no pending events (delayed
3117 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3118 program doesn't interfere with any following debugging session. */
3120 /* For cloned processes we must check both with __WCLONE and
3121 without, since the exit status of a cloned process isn't reported
3127 pid
= my_waitpid (GET_LWP (lp
->ptid
), NULL
, __WCLONE
);
3128 if (pid
!= (pid_t
) -1)
3130 if (debug_linux_nat
)
3131 fprintf_unfiltered (gdb_stdlog
,
3132 "KWC: wait %s received unknown.\n",
3133 target_pid_to_str (lp
->ptid
));
3134 /* The Linux kernel sometimes fails to kill a thread
3135 completely after PTRACE_KILL; that goes from the stop
3136 point in do_fork out to the one in
3137 get_signal_to_deliever and waits again. So kill it
3139 kill_callback (lp
, NULL
);
3142 while (pid
== GET_LWP (lp
->ptid
));
3144 gdb_assert (pid
== -1 && errno
== ECHILD
);
3149 pid
= my_waitpid (GET_LWP (lp
->ptid
), NULL
, 0);
3150 if (pid
!= (pid_t
) -1)
3152 if (debug_linux_nat
)
3153 fprintf_unfiltered (gdb_stdlog
,
3154 "KWC: wait %s received unk.\n",
3155 target_pid_to_str (lp
->ptid
));
3156 /* See the call to kill_callback above. */
3157 kill_callback (lp
, NULL
);
3160 while (pid
== GET_LWP (lp
->ptid
));
3162 gdb_assert (pid
== -1 && errno
== ECHILD
);
3167 linux_nat_kill (struct target_ops
*ops
)
3169 struct target_waitstatus last
;
3173 /* If we're stopped while forking and we haven't followed yet,
3174 kill the other task. We need to do this first because the
3175 parent will be sleeping if this is a vfork. */
3177 get_last_target_status (&last_ptid
, &last
);
3179 if (last
.kind
== TARGET_WAITKIND_FORKED
3180 || last
.kind
== TARGET_WAITKIND_VFORKED
)
3182 ptrace (PT_KILL
, PIDGET (last
.value
.related_pid
), 0, 0);
3186 if (forks_exist_p ())
3187 linux_fork_killall ();
3190 ptid_t ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
3191 /* Stop all threads before killing them, since ptrace requires
3192 that the thread is stopped to sucessfully PTRACE_KILL. */
3193 iterate_over_lwps (ptid
, stop_callback
, NULL
);
3194 /* ... and wait until all of them have reported back that
3195 they're no longer running. */
3196 iterate_over_lwps (ptid
, stop_wait_callback
, NULL
);
3198 /* Kill all LWP's ... */
3199 iterate_over_lwps (ptid
, kill_callback
, NULL
);
3201 /* ... and wait until we've flushed all events. */
3202 iterate_over_lwps (ptid
, kill_wait_callback
, NULL
);
3205 target_mourn_inferior ();
3209 linux_nat_mourn_inferior (struct target_ops
*ops
)
3211 purge_lwp_list (ptid_get_pid (inferior_ptid
));
3213 if (! forks_exist_p ())
3214 /* Normal case, no other forks available. */
3215 linux_ops
->to_mourn_inferior (ops
);
3217 /* Multi-fork case. The current inferior_ptid has exited, but
3218 there are other viable forks to debug. Delete the exiting
3219 one and context-switch to the first available. */
3220 linux_fork_mourn_inferior ();
3223 /* Convert a native/host siginfo object, into/from the siginfo in the
3224 layout of the inferiors' architecture. */
3227 siginfo_fixup (struct siginfo
*siginfo
, gdb_byte
*inf_siginfo
, int direction
)
3231 if (linux_nat_siginfo_fixup
!= NULL
)
3232 done
= linux_nat_siginfo_fixup (siginfo
, inf_siginfo
, direction
);
3234 /* If there was no callback, or the callback didn't do anything,
3235 then just do a straight memcpy. */
3239 memcpy (siginfo
, inf_siginfo
, sizeof (struct siginfo
));
3241 memcpy (inf_siginfo
, siginfo
, sizeof (struct siginfo
));
3246 linux_xfer_siginfo (struct target_ops
*ops
, enum target_object object
,
3247 const char *annex
, gdb_byte
*readbuf
,
3248 const gdb_byte
*writebuf
, ULONGEST offset
, LONGEST len
)
3251 struct siginfo siginfo
;
3252 gdb_byte inf_siginfo
[sizeof (struct siginfo
)];
3254 gdb_assert (object
== TARGET_OBJECT_SIGNAL_INFO
);
3255 gdb_assert (readbuf
|| writebuf
);
3257 pid
= GET_LWP (inferior_ptid
);
3259 pid
= GET_PID (inferior_ptid
);
3261 if (offset
> sizeof (siginfo
))
3265 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3269 /* When GDB is built as a 64-bit application, ptrace writes into
3270 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3271 inferior with a 64-bit GDB should look the same as debugging it
3272 with a 32-bit GDB, we need to convert it. GDB core always sees
3273 the converted layout, so any read/write will have to be done
3275 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
3277 if (offset
+ len
> sizeof (siginfo
))
3278 len
= sizeof (siginfo
) - offset
;
3280 if (readbuf
!= NULL
)
3281 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
3284 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
3286 /* Convert back to ptrace layout before flushing it out. */
3287 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
3290 ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3299 linux_nat_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3300 const char *annex
, gdb_byte
*readbuf
,
3301 const gdb_byte
*writebuf
,
3302 ULONGEST offset
, LONGEST len
)
3304 struct cleanup
*old_chain
;
3307 if (object
== TARGET_OBJECT_SIGNAL_INFO
)
3308 return linux_xfer_siginfo (ops
, object
, annex
, readbuf
, writebuf
,
3311 old_chain
= save_inferior_ptid ();
3313 if (is_lwp (inferior_ptid
))
3314 inferior_ptid
= pid_to_ptid (GET_LWP (inferior_ptid
));
3316 xfer
= linux_ops
->to_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
3319 do_cleanups (old_chain
);
3324 linux_thread_alive (ptid_t ptid
)
3328 gdb_assert (is_lwp (ptid
));
3330 /* Send signal 0 instead of anything ptrace, because ptracing a
3331 running thread errors out claiming that the thread doesn't
3333 err
= kill_lwp (GET_LWP (ptid
), 0);
3335 if (debug_linux_nat
)
3336 fprintf_unfiltered (gdb_stdlog
,
3337 "LLTA: KILL(SIG0) %s (%s)\n",
3338 target_pid_to_str (ptid
),
3339 err
? safe_strerror (err
) : "OK");
3348 linux_nat_thread_alive (struct target_ops
*ops
, ptid_t ptid
)
3350 return linux_thread_alive (ptid
);
3354 linux_nat_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
3356 static char buf
[64];
3359 && (GET_PID (ptid
) != GET_LWP (ptid
)
3360 || num_lwps (GET_PID (ptid
)) > 1))
3362 snprintf (buf
, sizeof (buf
), "LWP %ld", GET_LWP (ptid
));
3366 return normal_pid_to_str (ptid
);
3369 /* Accepts an integer PID; Returns a string representing a file that
3370 can be opened to get the symbols for the child process. */
3373 linux_child_pid_to_exec_file (int pid
)
3375 char *name1
, *name2
;
3377 name1
= xmalloc (MAXPATHLEN
);
3378 name2
= xmalloc (MAXPATHLEN
);
3379 make_cleanup (xfree
, name1
);
3380 make_cleanup (xfree
, name2
);
3381 memset (name2
, 0, MAXPATHLEN
);
3383 sprintf (name1
, "/proc/%d/exe", pid
);
3384 if (readlink (name1
, name2
, MAXPATHLEN
) > 0)
3390 /* Service function for corefiles and info proc. */
3393 read_mapping (FILE *mapfile
,
3398 char *device
, long long *inode
, char *filename
)
3400 int ret
= fscanf (mapfile
, "%llx-%llx %s %llx %s %llx",
3401 addr
, endaddr
, permissions
, offset
, device
, inode
);
3404 if (ret
> 0 && ret
!= EOF
)
3406 /* Eat everything up to EOL for the filename. This will prevent
3407 weird filenames (such as one with embedded whitespace) from
3408 confusing this code. It also makes this code more robust in
3409 respect to annotations the kernel may add after the filename.
3411 Note the filename is used for informational purposes
3413 ret
+= fscanf (mapfile
, "%[^\n]\n", filename
);
3416 return (ret
!= 0 && ret
!= EOF
);
3419 /* Fills the "to_find_memory_regions" target vector. Lists the memory
3420 regions in the inferior for a corefile. */
3423 linux_nat_find_memory_regions (int (*func
) (CORE_ADDR
,
3425 int, int, int, void *), void *obfd
)
3427 int pid
= PIDGET (inferior_ptid
);
3428 char mapsfilename
[MAXPATHLEN
];
3430 long long addr
, endaddr
, size
, offset
, inode
;
3431 char permissions
[8], device
[8], filename
[MAXPATHLEN
];
3432 int read
, write
, exec
;
3434 struct cleanup
*cleanup
;
3436 /* Compose the filename for the /proc memory map, and open it. */
3437 sprintf (mapsfilename
, "/proc/%d/maps", pid
);
3438 if ((mapsfile
= fopen (mapsfilename
, "r")) == NULL
)
3439 error (_("Could not open %s."), mapsfilename
);
3440 cleanup
= make_cleanup_fclose (mapsfile
);
3443 fprintf_filtered (gdb_stdout
,
3444 "Reading memory regions from %s\n", mapsfilename
);
3446 /* Now iterate until end-of-file. */
3447 while (read_mapping (mapsfile
, &addr
, &endaddr
, &permissions
[0],
3448 &offset
, &device
[0], &inode
, &filename
[0]))
3450 size
= endaddr
- addr
;
3452 /* Get the segment's permissions. */
3453 read
= (strchr (permissions
, 'r') != 0);
3454 write
= (strchr (permissions
, 'w') != 0);
3455 exec
= (strchr (permissions
, 'x') != 0);
3459 fprintf_filtered (gdb_stdout
,
3460 "Save segment, %lld bytes at 0x%s (%c%c%c)",
3461 size
, paddr_nz (addr
),
3463 write
? 'w' : ' ', exec
? 'x' : ' ');
3465 fprintf_filtered (gdb_stdout
, " for %s", filename
);
3466 fprintf_filtered (gdb_stdout
, "\n");
3469 /* Invoke the callback function to create the corefile
3471 func (addr
, size
, read
, write
, exec
, obfd
);
3473 do_cleanups (cleanup
);
3478 find_signalled_thread (struct thread_info
*info
, void *data
)
3480 if (info
->stop_signal
!= TARGET_SIGNAL_0
3481 && ptid_get_pid (info
->ptid
) == ptid_get_pid (inferior_ptid
))
3487 static enum target_signal
3488 find_stop_signal (void)
3490 struct thread_info
*info
=
3491 iterate_over_threads (find_signalled_thread
, NULL
);
3494 return info
->stop_signal
;
3496 return TARGET_SIGNAL_0
;
3499 /* Records the thread's register state for the corefile note
3503 linux_nat_do_thread_registers (bfd
*obfd
, ptid_t ptid
,
3504 char *note_data
, int *note_size
,
3505 enum target_signal stop_signal
)
3507 gdb_gregset_t gregs
;
3508 gdb_fpregset_t fpregs
;
3509 unsigned long lwp
= ptid_get_lwp (ptid
);
3510 struct regcache
*regcache
= get_thread_regcache (ptid
);
3511 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3512 const struct regset
*regset
;
3514 struct cleanup
*old_chain
;
3515 struct core_regset_section
*sect_list
;
3518 old_chain
= save_inferior_ptid ();
3519 inferior_ptid
= ptid
;
3520 target_fetch_registers (regcache
, -1);
3521 do_cleanups (old_chain
);
3523 core_regset_p
= gdbarch_regset_from_core_section_p (gdbarch
);
3524 sect_list
= gdbarch_core_regset_sections (gdbarch
);
3527 && (regset
= gdbarch_regset_from_core_section (gdbarch
, ".reg",
3528 sizeof (gregs
))) != NULL
3529 && regset
->collect_regset
!= NULL
)
3530 regset
->collect_regset (regset
, regcache
, -1,
3531 &gregs
, sizeof (gregs
));
3533 fill_gregset (regcache
, &gregs
, -1);
3535 note_data
= (char *) elfcore_write_prstatus (obfd
,
3539 stop_signal
, &gregs
);
3541 /* The loop below uses the new struct core_regset_section, which stores
3542 the supported section names and sizes for the core file. Note that
3543 note PRSTATUS needs to be treated specially. But the other notes are
3544 structurally the same, so they can benefit from the new struct. */
3545 if (core_regset_p
&& sect_list
!= NULL
)
3546 while (sect_list
->sect_name
!= NULL
)
3548 /* .reg was already handled above. */
3549 if (strcmp (sect_list
->sect_name
, ".reg") == 0)
3554 regset
= gdbarch_regset_from_core_section (gdbarch
,
3555 sect_list
->sect_name
,
3557 gdb_assert (regset
&& regset
->collect_regset
);
3558 gdb_regset
= xmalloc (sect_list
->size
);
3559 regset
->collect_regset (regset
, regcache
, -1,
3560 gdb_regset
, sect_list
->size
);
3561 note_data
= (char *) elfcore_write_register_note (obfd
,
3564 sect_list
->sect_name
,
3571 /* For architectures that does not have the struct core_regset_section
3572 implemented, we use the old method. When all the architectures have
3573 the new support, the code below should be deleted. */
3577 && (regset
= gdbarch_regset_from_core_section (gdbarch
, ".reg2",
3578 sizeof (fpregs
))) != NULL
3579 && regset
->collect_regset
!= NULL
)
3580 regset
->collect_regset (regset
, regcache
, -1,
3581 &fpregs
, sizeof (fpregs
));
3583 fill_fpregset (regcache
, &fpregs
, -1);
3585 note_data
= (char *) elfcore_write_prfpreg (obfd
,
3588 &fpregs
, sizeof (fpregs
));
3594 struct linux_nat_corefile_thread_data
3600 enum target_signal stop_signal
;
3603 /* Called by gdbthread.c once per thread. Records the thread's
3604 register state for the corefile note section. */
3607 linux_nat_corefile_thread_callback (struct lwp_info
*ti
, void *data
)
3609 struct linux_nat_corefile_thread_data
*args
= data
;
3611 args
->note_data
= linux_nat_do_thread_registers (args
->obfd
,
3621 /* Fills the "to_make_corefile_note" target vector. Builds the note
3622 section for a corefile, and returns it in a malloc buffer. */
3625 linux_nat_make_corefile_notes (bfd
*obfd
, int *note_size
)
3627 struct linux_nat_corefile_thread_data thread_args
;
3628 struct cleanup
*old_chain
;
3629 /* The variable size must be >= sizeof (prpsinfo_t.pr_fname). */
3630 char fname
[16] = { '\0' };
3631 /* The variable size must be >= sizeof (prpsinfo_t.pr_psargs). */
3632 char psargs
[80] = { '\0' };
3633 char *note_data
= NULL
;
3634 ptid_t current_ptid
= inferior_ptid
;
3635 ptid_t filter
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
3639 if (get_exec_file (0))
3641 strncpy (fname
, strrchr (get_exec_file (0), '/') + 1, sizeof (fname
));
3642 strncpy (psargs
, get_exec_file (0), sizeof (psargs
));
3643 if (get_inferior_args ())
3646 char *psargs_end
= psargs
+ sizeof (psargs
);
3648 /* linux_elfcore_write_prpsinfo () handles zero unterminated
3650 string_end
= memchr (psargs
, 0, sizeof (psargs
));
3651 if (string_end
!= NULL
)
3653 *string_end
++ = ' ';
3654 strncpy (string_end
, get_inferior_args (),
3655 psargs_end
- string_end
);
3658 note_data
= (char *) elfcore_write_prpsinfo (obfd
,
3660 note_size
, fname
, psargs
);
3663 /* Dump information for threads. */
3664 thread_args
.obfd
= obfd
;
3665 thread_args
.note_data
= note_data
;
3666 thread_args
.note_size
= note_size
;
3667 thread_args
.num_notes
= 0;
3668 thread_args
.stop_signal
= find_stop_signal ();
3669 iterate_over_lwps (filter
, linux_nat_corefile_thread_callback
, &thread_args
);
3670 gdb_assert (thread_args
.num_notes
!= 0);
3671 note_data
= thread_args
.note_data
;
3673 auxv_len
= target_read_alloc (¤t_target
, TARGET_OBJECT_AUXV
,
3677 note_data
= elfcore_write_note (obfd
, note_data
, note_size
,
3678 "CORE", NT_AUXV
, auxv
, auxv_len
);
3682 make_cleanup (xfree
, note_data
);
3686 /* Implement the "info proc" command. */
3689 linux_nat_info_proc_cmd (char *args
, int from_tty
)
3691 /* A long is used for pid instead of an int to avoid a loss of precision
3692 compiler warning from the output of strtoul. */
3693 long pid
= PIDGET (inferior_ptid
);
3696 char buffer
[MAXPATHLEN
];
3697 char fname1
[MAXPATHLEN
], fname2
[MAXPATHLEN
];
3710 /* Break up 'args' into an argv array. */
3711 argv
= gdb_buildargv (args
);
3712 make_cleanup_freeargv (argv
);
3714 while (argv
!= NULL
&& *argv
!= NULL
)
3716 if (isdigit (argv
[0][0]))
3718 pid
= strtoul (argv
[0], NULL
, 10);
3720 else if (strncmp (argv
[0], "mappings", strlen (argv
[0])) == 0)
3724 else if (strcmp (argv
[0], "status") == 0)
3728 else if (strcmp (argv
[0], "stat") == 0)
3732 else if (strcmp (argv
[0], "cmd") == 0)
3736 else if (strncmp (argv
[0], "exe", strlen (argv
[0])) == 0)
3740 else if (strcmp (argv
[0], "cwd") == 0)
3744 else if (strncmp (argv
[0], "all", strlen (argv
[0])) == 0)
3750 /* [...] (future options here) */
3755 error (_("No current process: you must name one."));
3757 sprintf (fname1
, "/proc/%ld", pid
);
3758 if (stat (fname1
, &dummy
) != 0)
3759 error (_("No /proc directory: '%s'"), fname1
);
3761 printf_filtered (_("process %ld\n"), pid
);
3762 if (cmdline_f
|| all
)
3764 sprintf (fname1
, "/proc/%ld/cmdline", pid
);
3765 if ((procfile
= fopen (fname1
, "r")) != NULL
)
3767 struct cleanup
*cleanup
= make_cleanup_fclose (procfile
);
3768 if (fgets (buffer
, sizeof (buffer
), procfile
))
3769 printf_filtered ("cmdline = '%s'\n", buffer
);
3771 warning (_("unable to read '%s'"), fname1
);
3772 do_cleanups (cleanup
);
3775 warning (_("unable to open /proc file '%s'"), fname1
);
3779 sprintf (fname1
, "/proc/%ld/cwd", pid
);
3780 memset (fname2
, 0, sizeof (fname2
));
3781 if (readlink (fname1
, fname2
, sizeof (fname2
)) > 0)
3782 printf_filtered ("cwd = '%s'\n", fname2
);
3784 warning (_("unable to read link '%s'"), fname1
);
3788 sprintf (fname1
, "/proc/%ld/exe", pid
);
3789 memset (fname2
, 0, sizeof (fname2
));
3790 if (readlink (fname1
, fname2
, sizeof (fname2
)) > 0)
3791 printf_filtered ("exe = '%s'\n", fname2
);
3793 warning (_("unable to read link '%s'"), fname1
);
3795 if (mappings_f
|| all
)
3797 sprintf (fname1
, "/proc/%ld/maps", pid
);
3798 if ((procfile
= fopen (fname1
, "r")) != NULL
)
3800 long long addr
, endaddr
, size
, offset
, inode
;
3801 char permissions
[8], device
[8], filename
[MAXPATHLEN
];
3802 struct cleanup
*cleanup
;
3804 cleanup
= make_cleanup_fclose (procfile
);
3805 printf_filtered (_("Mapped address spaces:\n\n"));
3806 if (gdbarch_addr_bit (current_gdbarch
) == 32)
3808 printf_filtered ("\t%10s %10s %10s %10s %7s\n",
3811 " Size", " Offset", "objfile");
3815 printf_filtered (" %18s %18s %10s %10s %7s\n",
3818 " Size", " Offset", "objfile");
3821 while (read_mapping (procfile
, &addr
, &endaddr
, &permissions
[0],
3822 &offset
, &device
[0], &inode
, &filename
[0]))
3824 size
= endaddr
- addr
;
3826 /* FIXME: carlton/2003-08-27: Maybe the printf_filtered
3827 calls here (and possibly above) should be abstracted
3828 out into their own functions? Andrew suggests using
3829 a generic local_address_string instead to print out
3830 the addresses; that makes sense to me, too. */
3832 if (gdbarch_addr_bit (current_gdbarch
) == 32)
3834 printf_filtered ("\t%#10lx %#10lx %#10x %#10x %7s\n",
3835 (unsigned long) addr
, /* FIXME: pr_addr */
3836 (unsigned long) endaddr
,
3838 (unsigned int) offset
,
3839 filename
[0] ? filename
: "");
3843 printf_filtered (" %#18lx %#18lx %#10x %#10x %7s\n",
3844 (unsigned long) addr
, /* FIXME: pr_addr */
3845 (unsigned long) endaddr
,
3847 (unsigned int) offset
,
3848 filename
[0] ? filename
: "");
3852 do_cleanups (cleanup
);
3855 warning (_("unable to open /proc file '%s'"), fname1
);
3857 if (status_f
|| all
)
3859 sprintf (fname1
, "/proc/%ld/status", pid
);
3860 if ((procfile
= fopen (fname1
, "r")) != NULL
)
3862 struct cleanup
*cleanup
= make_cleanup_fclose (procfile
);
3863 while (fgets (buffer
, sizeof (buffer
), procfile
) != NULL
)
3864 puts_filtered (buffer
);
3865 do_cleanups (cleanup
);
3868 warning (_("unable to open /proc file '%s'"), fname1
);
3872 sprintf (fname1
, "/proc/%ld/stat", pid
);
3873 if ((procfile
= fopen (fname1
, "r")) != NULL
)
3878 struct cleanup
*cleanup
= make_cleanup_fclose (procfile
);
3880 if (fscanf (procfile
, "%d ", &itmp
) > 0)
3881 printf_filtered (_("Process: %d\n"), itmp
);
3882 if (fscanf (procfile
, "(%[^)]) ", &buffer
[0]) > 0)
3883 printf_filtered (_("Exec file: %s\n"), buffer
);
3884 if (fscanf (procfile
, "%c ", &ctmp
) > 0)
3885 printf_filtered (_("State: %c\n"), ctmp
);
3886 if (fscanf (procfile
, "%d ", &itmp
) > 0)
3887 printf_filtered (_("Parent process: %d\n"), itmp
);
3888 if (fscanf (procfile
, "%d ", &itmp
) > 0)
3889 printf_filtered (_("Process group: %d\n"), itmp
);
3890 if (fscanf (procfile
, "%d ", &itmp
) > 0)
3891 printf_filtered (_("Session id: %d\n"), itmp
);
3892 if (fscanf (procfile
, "%d ", &itmp
) > 0)
3893 printf_filtered (_("TTY: %d\n"), itmp
);
3894 if (fscanf (procfile
, "%d ", &itmp
) > 0)
3895 printf_filtered (_("TTY owner process group: %d\n"), itmp
);
3896 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3897 printf_filtered (_("Flags: 0x%lx\n"), ltmp
);
3898 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3899 printf_filtered (_("Minor faults (no memory page): %lu\n"),
3900 (unsigned long) ltmp
);
3901 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3902 printf_filtered (_("Minor faults, children: %lu\n"),
3903 (unsigned long) ltmp
);
3904 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3905 printf_filtered (_("Major faults (memory page faults): %lu\n"),
3906 (unsigned long) ltmp
);
3907 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3908 printf_filtered (_("Major faults, children: %lu\n"),
3909 (unsigned long) ltmp
);
3910 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3911 printf_filtered (_("utime: %ld\n"), ltmp
);
3912 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3913 printf_filtered (_("stime: %ld\n"), ltmp
);
3914 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3915 printf_filtered (_("utime, children: %ld\n"), ltmp
);
3916 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3917 printf_filtered (_("stime, children: %ld\n"), ltmp
);
3918 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3919 printf_filtered (_("jiffies remaining in current time slice: %ld\n"),
3921 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3922 printf_filtered (_("'nice' value: %ld\n"), ltmp
);
3923 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3924 printf_filtered (_("jiffies until next timeout: %lu\n"),
3925 (unsigned long) ltmp
);
3926 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3927 printf_filtered (_("jiffies until next SIGALRM: %lu\n"),
3928 (unsigned long) ltmp
);
3929 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3930 printf_filtered (_("start time (jiffies since system boot): %ld\n"),
3932 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3933 printf_filtered (_("Virtual memory size: %lu\n"),
3934 (unsigned long) ltmp
);
3935 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3936 printf_filtered (_("Resident set size: %lu\n"), (unsigned long) ltmp
);
3937 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3938 printf_filtered (_("rlim: %lu\n"), (unsigned long) ltmp
);
3939 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3940 printf_filtered (_("Start of text: 0x%lx\n"), ltmp
);
3941 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3942 printf_filtered (_("End of text: 0x%lx\n"), ltmp
);
3943 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3944 printf_filtered (_("Start of stack: 0x%lx\n"), ltmp
);
3945 #if 0 /* Don't know how architecture-dependent the rest is...
3946 Anyway the signal bitmap info is available from "status". */
3947 if (fscanf (procfile
, "%lu ", <mp
) > 0) /* FIXME arch? */
3948 printf_filtered (_("Kernel stack pointer: 0x%lx\n"), ltmp
);
3949 if (fscanf (procfile
, "%lu ", <mp
) > 0) /* FIXME arch? */
3950 printf_filtered (_("Kernel instr pointer: 0x%lx\n"), ltmp
);
3951 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3952 printf_filtered (_("Pending signals bitmap: 0x%lx\n"), ltmp
);
3953 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3954 printf_filtered (_("Blocked signals bitmap: 0x%lx\n"), ltmp
);
3955 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3956 printf_filtered (_("Ignored signals bitmap: 0x%lx\n"), ltmp
);
3957 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3958 printf_filtered (_("Catched signals bitmap: 0x%lx\n"), ltmp
);
3959 if (fscanf (procfile
, "%lu ", <mp
) > 0) /* FIXME arch? */
3960 printf_filtered (_("wchan (system call): 0x%lx\n"), ltmp
);
3962 do_cleanups (cleanup
);
3965 warning (_("unable to open /proc file '%s'"), fname1
);
3969 /* Implement the to_xfer_partial interface for memory reads using the /proc
3970 filesystem. Because we can use a single read() call for /proc, this
3971 can be much more efficient than banging away at PTRACE_PEEKTEXT,
3972 but it doesn't support writes. */
3975 linux_proc_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3976 const char *annex
, gdb_byte
*readbuf
,
3977 const gdb_byte
*writebuf
,
3978 ULONGEST offset
, LONGEST len
)
3984 if (object
!= TARGET_OBJECT_MEMORY
|| !readbuf
)
3987 /* Don't bother for one word. */
3988 if (len
< 3 * sizeof (long))
3991 /* We could keep this file open and cache it - possibly one per
3992 thread. That requires some juggling, but is even faster. */
3993 sprintf (filename
, "/proc/%d/mem", PIDGET (inferior_ptid
));
3994 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
3998 /* If pread64 is available, use it. It's faster if the kernel
3999 supports it (only one syscall), and it's 64-bit safe even on
4000 32-bit platforms (for instance, SPARC debugging a SPARC64
4003 if (pread64 (fd
, readbuf
, len
, offset
) != len
)
4005 if (lseek (fd
, offset
, SEEK_SET
) == -1 || read (fd
, readbuf
, len
) != len
)
4015 /* Parse LINE as a signal set and add its set bits to SIGS. */
4018 add_line_to_sigset (const char *line
, sigset_t
*sigs
)
4020 int len
= strlen (line
) - 1;
4024 if (line
[len
] != '\n')
4025 error (_("Could not parse signal set: %s"), line
);
4033 if (*p
>= '0' && *p
<= '9')
4035 else if (*p
>= 'a' && *p
<= 'f')
4036 digit
= *p
- 'a' + 10;
4038 error (_("Could not parse signal set: %s"), line
);
4043 sigaddset (sigs
, signum
+ 1);
4045 sigaddset (sigs
, signum
+ 2);
4047 sigaddset (sigs
, signum
+ 3);
4049 sigaddset (sigs
, signum
+ 4);
4055 /* Find process PID's pending signals from /proc/pid/status and set
4059 linux_proc_pending_signals (int pid
, sigset_t
*pending
, sigset_t
*blocked
, sigset_t
*ignored
)
4062 char buffer
[MAXPATHLEN
], fname
[MAXPATHLEN
];
4064 struct cleanup
*cleanup
;
4066 sigemptyset (pending
);
4067 sigemptyset (blocked
);
4068 sigemptyset (ignored
);
4069 sprintf (fname
, "/proc/%d/status", pid
);
4070 procfile
= fopen (fname
, "r");
4071 if (procfile
== NULL
)
4072 error (_("Could not open %s"), fname
);
4073 cleanup
= make_cleanup_fclose (procfile
);
4075 while (fgets (buffer
, MAXPATHLEN
, procfile
) != NULL
)
4077 /* Normal queued signals are on the SigPnd line in the status
4078 file. However, 2.6 kernels also have a "shared" pending
4079 queue for delivering signals to a thread group, so check for
4082 Unfortunately some Red Hat kernels include the shared pending
4083 queue but not the ShdPnd status field. */
4085 if (strncmp (buffer
, "SigPnd:\t", 8) == 0)
4086 add_line_to_sigset (buffer
+ 8, pending
);
4087 else if (strncmp (buffer
, "ShdPnd:\t", 8) == 0)
4088 add_line_to_sigset (buffer
+ 8, pending
);
4089 else if (strncmp (buffer
, "SigBlk:\t", 8) == 0)
4090 add_line_to_sigset (buffer
+ 8, blocked
);
4091 else if (strncmp (buffer
, "SigIgn:\t", 8) == 0)
4092 add_line_to_sigset (buffer
+ 8, ignored
);
4095 do_cleanups (cleanup
);
4099 linux_nat_xfer_osdata (struct target_ops
*ops
, enum target_object object
,
4100 const char *annex
, gdb_byte
*readbuf
,
4101 const gdb_byte
*writebuf
, ULONGEST offset
, LONGEST len
)
4103 /* We make the process list snapshot when the object starts to be
4105 static const char *buf
;
4106 static LONGEST len_avail
= -1;
4107 static struct obstack obstack
;
4111 gdb_assert (object
== TARGET_OBJECT_OSDATA
);
4113 if (strcmp (annex
, "processes") != 0)
4116 gdb_assert (readbuf
&& !writebuf
);
4120 if (len_avail
!= -1 && len_avail
!= 0)
4121 obstack_free (&obstack
, NULL
);
4124 obstack_init (&obstack
);
4125 obstack_grow_str (&obstack
, "<osdata type=\"processes\">\n");
4127 dirp
= opendir ("/proc");
4131 while ((dp
= readdir (dirp
)) != NULL
)
4133 struct stat statbuf
;
4134 char procentry
[sizeof ("/proc/4294967295")];
4136 if (!isdigit (dp
->d_name
[0])
4137 || NAMELEN (dp
) > sizeof ("4294967295") - 1)
4140 sprintf (procentry
, "/proc/%s", dp
->d_name
);
4141 if (stat (procentry
, &statbuf
) == 0
4142 && S_ISDIR (statbuf
.st_mode
))
4146 char cmd
[MAXPATHLEN
+ 1];
4147 struct passwd
*entry
;
4149 pathname
= xstrprintf ("/proc/%s/cmdline", dp
->d_name
);
4150 entry
= getpwuid (statbuf
.st_uid
);
4152 if ((f
= fopen (pathname
, "r")) != NULL
)
4154 size_t len
= fread (cmd
, 1, sizeof (cmd
) - 1, f
);
4158 for (i
= 0; i
< len
; i
++)
4163 obstack_xml_printf (
4166 "<column name=\"pid\">%s</column>"
4167 "<column name=\"user\">%s</column>"
4168 "<column name=\"command\">%s</column>"
4171 entry
? entry
->pw_name
: "?",
4184 obstack_grow_str0 (&obstack
, "</osdata>\n");
4185 buf
= obstack_finish (&obstack
);
4186 len_avail
= strlen (buf
);
4189 if (offset
>= len_avail
)
4191 /* Done. Get rid of the obstack. */
4192 obstack_free (&obstack
, NULL
);
4198 if (len
> len_avail
- offset
)
4199 len
= len_avail
- offset
;
4200 memcpy (readbuf
, buf
+ offset
, len
);
4206 linux_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4207 const char *annex
, gdb_byte
*readbuf
,
4208 const gdb_byte
*writebuf
, ULONGEST offset
, LONGEST len
)
4212 if (object
== TARGET_OBJECT_AUXV
)
4213 return procfs_xfer_auxv (ops
, object
, annex
, readbuf
, writebuf
,
4216 if (object
== TARGET_OBJECT_OSDATA
)
4217 return linux_nat_xfer_osdata (ops
, object
, annex
, readbuf
, writebuf
,
4220 xfer
= linux_proc_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4225 return super_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4229 /* Create a prototype generic GNU/Linux target. The client can override
4230 it with local methods. */
4233 linux_target_install_ops (struct target_ops
*t
)
4235 t
->to_insert_fork_catchpoint
= linux_child_insert_fork_catchpoint
;
4236 t
->to_insert_vfork_catchpoint
= linux_child_insert_vfork_catchpoint
;
4237 t
->to_insert_exec_catchpoint
= linux_child_insert_exec_catchpoint
;
4238 t
->to_pid_to_exec_file
= linux_child_pid_to_exec_file
;
4239 t
->to_post_startup_inferior
= linux_child_post_startup_inferior
;
4240 t
->to_post_attach
= linux_child_post_attach
;
4241 t
->to_follow_fork
= linux_child_follow_fork
;
4242 t
->to_find_memory_regions
= linux_nat_find_memory_regions
;
4243 t
->to_make_corefile_notes
= linux_nat_make_corefile_notes
;
4245 super_xfer_partial
= t
->to_xfer_partial
;
4246 t
->to_xfer_partial
= linux_xfer_partial
;
4252 struct target_ops
*t
;
4254 t
= inf_ptrace_target ();
4255 linux_target_install_ops (t
);
4261 linux_trad_target (CORE_ADDR (*register_u_offset
)(struct gdbarch
*, int, int))
4263 struct target_ops
*t
;
4265 t
= inf_ptrace_trad_target (register_u_offset
);
4266 linux_target_install_ops (t
);
4271 /* target_is_async_p implementation. */
4274 linux_nat_is_async_p (void)
4276 /* NOTE: palves 2008-03-21: We're only async when the user requests
4277 it explicitly with the "set target-async" command.
4278 Someday, linux will always be async. */
4279 if (!target_async_permitted
)
4282 /* See target.h/target_async_mask. */
4283 return linux_nat_async_mask_value
;
4286 /* target_can_async_p implementation. */
4289 linux_nat_can_async_p (void)
4291 /* NOTE: palves 2008-03-21: We're only async when the user requests
4292 it explicitly with the "set target-async" command.
4293 Someday, linux will always be async. */
4294 if (!target_async_permitted
)
4297 /* See target.h/target_async_mask. */
4298 return linux_nat_async_mask_value
;
4302 linux_nat_supports_non_stop (void)
4307 /* True if we want to support multi-process. To be removed when GDB
4308 supports multi-exec. */
4310 int linux_multi_process
= 0;
4313 linux_nat_supports_multi_process (void)
4315 return linux_multi_process
;
4318 /* target_async_mask implementation. */
4321 linux_nat_async_mask (int new_mask
)
4323 int curr_mask
= linux_nat_async_mask_value
;
4325 if (curr_mask
!= new_mask
)
4329 linux_nat_async (NULL
, 0);
4330 linux_nat_async_mask_value
= new_mask
;
4334 linux_nat_async_mask_value
= new_mask
;
4336 /* If we're going out of async-mask in all-stop, then the
4337 inferior is stopped. The next resume will call
4338 target_async. In non-stop, the target event source
4339 should be always registered in the event loop. Do so
4342 linux_nat_async (inferior_event_handler
, 0);
4349 static int async_terminal_is_ours
= 1;
4351 /* target_terminal_inferior implementation. */
4354 linux_nat_terminal_inferior (void)
4356 if (!target_is_async_p ())
4358 /* Async mode is disabled. */
4359 terminal_inferior ();
4363 terminal_inferior ();
4365 /* Calls to target_terminal_*() are meant to be idempotent. */
4366 if (!async_terminal_is_ours
)
4369 delete_file_handler (input_fd
);
4370 async_terminal_is_ours
= 0;
4374 /* target_terminal_ours implementation. */
4377 linux_nat_terminal_ours (void)
4379 if (!target_is_async_p ())
4381 /* Async mode is disabled. */
4386 /* GDB should never give the terminal to the inferior if the
4387 inferior is running in the background (run&, continue&, etc.),
4388 but claiming it sure should. */
4391 if (async_terminal_is_ours
)
4394 clear_sigint_trap ();
4395 add_file_handler (input_fd
, stdin_event_handler
, 0);
4396 async_terminal_is_ours
= 1;
4399 static void (*async_client_callback
) (enum inferior_event_type event_type
,
4401 static void *async_client_context
;
4403 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4404 so we notice when any child changes state, and notify the
4405 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4406 above to wait for the arrival of a SIGCHLD. */
4409 sigchld_handler (int signo
)
4411 int old_errno
= errno
;
4413 if (debug_linux_nat_async
)
4414 fprintf_unfiltered (gdb_stdlog
, "sigchld\n");
4416 if (signo
== SIGCHLD
4417 && linux_nat_event_pipe
[0] != -1)
4418 async_file_mark (); /* Let the event loop know that there are
4419 events to handle. */
4424 /* Callback registered with the target events file descriptor. */
4427 handle_target_event (int error
, gdb_client_data client_data
)
4429 (*async_client_callback
) (INF_REG_EVENT
, async_client_context
);
4432 /* Create/destroy the target events pipe. Returns previous state. */
4435 linux_async_pipe (int enable
)
4437 int previous
= (linux_nat_event_pipe
[0] != -1);
4439 if (previous
!= enable
)
4443 block_child_signals (&prev_mask
);
4447 if (pipe (linux_nat_event_pipe
) == -1)
4448 internal_error (__FILE__
, __LINE__
,
4449 "creating event pipe failed.");
4451 fcntl (linux_nat_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4452 fcntl (linux_nat_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4456 close (linux_nat_event_pipe
[0]);
4457 close (linux_nat_event_pipe
[1]);
4458 linux_nat_event_pipe
[0] = -1;
4459 linux_nat_event_pipe
[1] = -1;
4462 restore_child_signals_mask (&prev_mask
);
4468 /* target_async implementation. */
4471 linux_nat_async (void (*callback
) (enum inferior_event_type event_type
,
4472 void *context
), void *context
)
4474 if (linux_nat_async_mask_value
== 0 || !target_async_permitted
)
4475 internal_error (__FILE__
, __LINE__
,
4476 "Calling target_async when async is masked");
4478 if (callback
!= NULL
)
4480 async_client_callback
= callback
;
4481 async_client_context
= context
;
4482 if (!linux_async_pipe (1))
4484 add_file_handler (linux_nat_event_pipe
[0],
4485 handle_target_event
, NULL
);
4486 /* There may be pending events to handle. Tell the event loop
4493 async_client_callback
= callback
;
4494 async_client_context
= context
;
4495 delete_file_handler (linux_nat_event_pipe
[0]);
4496 linux_async_pipe (0);
4501 /* Stop an LWP, and push a TARGET_SIGNAL_0 stop status if no other
4505 linux_nat_stop_lwp (struct lwp_info
*lwp
, void *data
)
4510 ptid_t ptid
= lwp
->ptid
;
4512 if (debug_linux_nat
)
4513 fprintf_unfiltered (gdb_stdlog
,
4514 "LNSL: running -> suspending %s\n",
4515 target_pid_to_str (lwp
->ptid
));
4518 stop_callback (lwp
, NULL
);
4519 stop_wait_callback (lwp
, NULL
);
4521 /* If the lwp exits while we try to stop it, there's nothing
4523 lwp
= find_lwp_pid (ptid
);
4527 /* If we didn't collect any signal other than SIGSTOP while
4528 stopping the LWP, push a SIGNAL_0 event. In either case, the
4529 event-loop will end up calling target_wait which will collect
4531 if (lwp
->status
== 0)
4532 lwp
->status
= W_STOPCODE (0);
4537 /* Already known to be stopped; do nothing. */
4539 if (debug_linux_nat
)
4541 if (find_thread_pid (lwp
->ptid
)->stop_requested
)
4542 fprintf_unfiltered (gdb_stdlog
, "\
4543 LNSL: already stopped/stop_requested %s\n",
4544 target_pid_to_str (lwp
->ptid
));
4546 fprintf_unfiltered (gdb_stdlog
, "\
4547 LNSL: already stopped/no stop_requested yet %s\n",
4548 target_pid_to_str (lwp
->ptid
));
4555 linux_nat_stop (ptid_t ptid
)
4558 iterate_over_lwps (ptid
, linux_nat_stop_lwp
, NULL
);
4560 linux_ops
->to_stop (ptid
);
4564 linux_nat_close (int quitting
)
4566 /* Unregister from the event loop. */
4567 if (target_is_async_p ())
4568 target_async (NULL
, 0);
4570 /* Reset the async_masking. */
4571 linux_nat_async_mask_value
= 1;
4573 if (linux_ops
->to_close
)
4574 linux_ops
->to_close (quitting
);
4578 linux_nat_add_target (struct target_ops
*t
)
4580 /* Save the provided single-threaded target. We save this in a separate
4581 variable because another target we've inherited from (e.g. inf-ptrace)
4582 may have saved a pointer to T; we want to use it for the final
4583 process stratum target. */
4584 linux_ops_saved
= *t
;
4585 linux_ops
= &linux_ops_saved
;
4587 /* Override some methods for multithreading. */
4588 t
->to_create_inferior
= linux_nat_create_inferior
;
4589 t
->to_attach
= linux_nat_attach
;
4590 t
->to_detach
= linux_nat_detach
;
4591 t
->to_resume
= linux_nat_resume
;
4592 t
->to_wait
= linux_nat_wait
;
4593 t
->to_xfer_partial
= linux_nat_xfer_partial
;
4594 t
->to_kill
= linux_nat_kill
;
4595 t
->to_mourn_inferior
= linux_nat_mourn_inferior
;
4596 t
->to_thread_alive
= linux_nat_thread_alive
;
4597 t
->to_pid_to_str
= linux_nat_pid_to_str
;
4598 t
->to_has_thread_control
= tc_schedlock
;
4600 t
->to_can_async_p
= linux_nat_can_async_p
;
4601 t
->to_is_async_p
= linux_nat_is_async_p
;
4602 t
->to_supports_non_stop
= linux_nat_supports_non_stop
;
4603 t
->to_async
= linux_nat_async
;
4604 t
->to_async_mask
= linux_nat_async_mask
;
4605 t
->to_terminal_inferior
= linux_nat_terminal_inferior
;
4606 t
->to_terminal_ours
= linux_nat_terminal_ours
;
4607 t
->to_close
= linux_nat_close
;
4609 /* Methods for non-stop support. */
4610 t
->to_stop
= linux_nat_stop
;
4612 t
->to_supports_multi_process
= linux_nat_supports_multi_process
;
4614 /* We don't change the stratum; this target will sit at
4615 process_stratum and thread_db will set at thread_stratum. This
4616 is a little strange, since this is a multi-threaded-capable
4617 target, but we want to be on the stack below thread_db, and we
4618 also want to be used for single-threaded processes. */
4623 /* Register a method to call whenever a new thread is attached. */
4625 linux_nat_set_new_thread (struct target_ops
*t
, void (*new_thread
) (ptid_t
))
4627 /* Save the pointer. We only support a single registered instance
4628 of the GNU/Linux native target, so we do not need to map this to
4630 linux_nat_new_thread
= new_thread
;
4633 /* Register a method that converts a siginfo object between the layout
4634 that ptrace returns, and the layout in the architecture of the
4637 linux_nat_set_siginfo_fixup (struct target_ops
*t
,
4638 int (*siginfo_fixup
) (struct siginfo
*,
4642 /* Save the pointer. */
4643 linux_nat_siginfo_fixup
= siginfo_fixup
;
4646 /* Return the saved siginfo associated with PTID. */
4648 linux_nat_get_siginfo (ptid_t ptid
)
4650 struct lwp_info
*lp
= find_lwp_pid (ptid
);
4652 gdb_assert (lp
!= NULL
);
4654 return &lp
->siginfo
;
4657 /* Provide a prototype to silence -Wmissing-prototypes. */
4658 extern initialize_file_ftype _initialize_linux_nat
;
4661 _initialize_linux_nat (void)
4665 add_info ("proc", linux_nat_info_proc_cmd
, _("\
4666 Show /proc process information about any running process.\n\
4667 Specify any process id, or use the program being debugged by default.\n\
4668 Specify any of the following keywords for detailed info:\n\
4669 mappings -- list of mapped memory regions.\n\
4670 stat -- list a bunch of random process info.\n\
4671 status -- list a different bunch of random process info.\n\
4672 all -- list all available /proc info."));
4674 add_setshow_zinteger_cmd ("lin-lwp", class_maintenance
,
4675 &debug_linux_nat
, _("\
4676 Set debugging of GNU/Linux lwp module."), _("\
4677 Show debugging of GNU/Linux lwp module."), _("\
4678 Enables printf debugging output."),
4680 show_debug_linux_nat
,
4681 &setdebuglist
, &showdebuglist
);
4683 add_setshow_zinteger_cmd ("lin-lwp-async", class_maintenance
,
4684 &debug_linux_nat_async
, _("\
4685 Set debugging of GNU/Linux async lwp module."), _("\
4686 Show debugging of GNU/Linux async lwp module."), _("\
4687 Enables printf debugging output."),
4689 show_debug_linux_nat_async
,
4690 &setdebuglist
, &showdebuglist
);
4692 /* Save this mask as the default. */
4693 sigprocmask (SIG_SETMASK
, NULL
, &normal_mask
);
4695 /* Install a SIGCHLD handler. */
4696 sigchld_action
.sa_handler
= sigchld_handler
;
4697 sigemptyset (&sigchld_action
.sa_mask
);
4698 sigchld_action
.sa_flags
= SA_RESTART
;
4700 /* Make it the default. */
4701 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
4703 /* Make sure we don't block SIGCHLD during a sigsuspend. */
4704 sigprocmask (SIG_SETMASK
, NULL
, &suspend_mask
);
4705 sigdelset (&suspend_mask
, SIGCHLD
);
4707 sigemptyset (&blocked_mask
);
4709 add_setshow_boolean_cmd ("disable-randomization", class_support
,
4710 &disable_randomization
, _("\
4711 Set disabling of debuggee's virtual address space randomization."), _("\
4712 Show disabling of debuggee's virtual address space randomization."), _("\
4713 When this mode is on (which is the default), randomization of the virtual\n\
4714 address space is disabled. Standalone programs run with the randomization\n\
4715 enabled by default on some platforms."),
4716 &set_disable_randomization
,
4717 &show_disable_randomization
,
4718 &setlist
, &showlist
);
4722 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
4723 the GNU/Linux Threads library and therefore doesn't really belong
4726 /* Read variable NAME in the target and return its value if found.
4727 Otherwise return zero. It is assumed that the type of the variable
4731 get_signo (const char *name
)
4733 struct minimal_symbol
*ms
;
4736 ms
= lookup_minimal_symbol (name
, NULL
, NULL
);
4740 if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms
), (gdb_byte
*) &signo
,
4741 sizeof (signo
)) != 0)
4747 /* Return the set of signals used by the threads library in *SET. */
4750 lin_thread_get_thread_signals (sigset_t
*set
)
4752 struct sigaction action
;
4753 int restart
, cancel
;
4755 sigemptyset (&blocked_mask
);
4758 restart
= get_signo ("__pthread_sig_restart");
4759 cancel
= get_signo ("__pthread_sig_cancel");
4761 /* LinuxThreads normally uses the first two RT signals, but in some legacy
4762 cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
4763 not provide any way for the debugger to query the signal numbers -
4764 fortunately they don't change! */
4767 restart
= __SIGRTMIN
;
4770 cancel
= __SIGRTMIN
+ 1;
4772 sigaddset (set
, restart
);
4773 sigaddset (set
, cancel
);
4775 /* The GNU/Linux Threads library makes terminating threads send a
4776 special "cancel" signal instead of SIGCHLD. Make sure we catch
4777 those (to prevent them from terminating GDB itself, which is
4778 likely to be their default action) and treat them the same way as
4781 action
.sa_handler
= sigchld_handler
;
4782 sigemptyset (&action
.sa_mask
);
4783 action
.sa_flags
= SA_RESTART
;
4784 sigaction (cancel
, &action
, NULL
);
4786 /* We block the "cancel" signal throughout this code ... */
4787 sigaddset (&blocked_mask
, cancel
);
4788 sigprocmask (SIG_BLOCK
, &blocked_mask
, NULL
);
4790 /* ... except during a sigsuspend. */
4791 sigdelset (&suspend_mask
, cancel
);