1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001-2012 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 #include "gdb_string.h"
25 #include "gdb_assert.h"
26 #ifdef HAVE_TKILL_SYSCALL
28 #include <sys/syscall.h>
30 #include <sys/ptrace.h>
31 #include "linux-nat.h"
32 #include "linux-ptrace.h"
33 #include "linux-procfs.h"
34 #include "linux-fork.h"
35 #include "gdbthread.h"
39 #include "inf-child.h"
40 #include "inf-ptrace.h"
42 #include <sys/param.h> /* for MAXPATHLEN */
43 #include <sys/procfs.h> /* for elf_gregset etc. */
44 #include "elf-bfd.h" /* for elfcore_write_* */
45 #include "gregset.h" /* for gregset */
46 #include "gdbcore.h" /* for get_exec_file */
47 #include <ctype.h> /* for isdigit */
48 #include "gdbthread.h" /* for struct thread_info etc. */
49 #include "gdb_stat.h" /* for struct stat */
50 #include <fcntl.h> /* for O_RDONLY */
52 #include "event-loop.h"
53 #include "event-top.h"
55 #include <sys/types.h>
56 #include "gdb_dirent.h"
57 #include "xml-support.h"
61 #include "linux-osdata.h"
62 #include "linux-tdep.h"
65 #include "tracepoint.h"
66 #include "exceptions.h"
67 #include "linux-ptrace.h"
71 #define SPUFS_MAGIC 0x23c9b64e
74 #ifdef HAVE_PERSONALITY
75 # include <sys/personality.h>
76 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
77 # define ADDR_NO_RANDOMIZE 0x0040000
79 #endif /* HAVE_PERSONALITY */
81 /* This comment documents high-level logic of this file.
83 Waiting for events in sync mode
84 ===============================
86 When waiting for an event in a specific thread, we just use waitpid, passing
87 the specific pid, and not passing WNOHANG.
89 When waiting for an event in all threads, waitpid is not quite good. Prior to
90 version 2.4, Linux can either wait for event in main thread, or in secondary
91 threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might
92 miss an event. The solution is to use non-blocking waitpid, together with
93 sigsuspend. First, we use non-blocking waitpid to get an event in the main
94 process, if any. Second, we use non-blocking waitpid with the __WCLONED
95 flag to check for events in cloned processes. If nothing is found, we use
96 sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something
97 happened to a child process -- and SIGCHLD will be delivered both for events
98 in main debugged process and in cloned processes. As soon as we know there's
99 an event, we get back to calling nonblocking waitpid with and without
102 Note that SIGCHLD should be blocked between waitpid and sigsuspend calls,
103 so that we don't miss a signal. If SIGCHLD arrives in between, when it's
104 blocked, the signal becomes pending and sigsuspend immediately
105 notices it and returns.
107 Waiting for events in async mode
108 ================================
110 In async mode, GDB should always be ready to handle both user input
111 and target events, so neither blocking waitpid nor sigsuspend are
112 viable options. Instead, we should asynchronously notify the GDB main
113 event loop whenever there's an unprocessed event from the target. We
114 detect asynchronous target events by handling SIGCHLD signals. To
115 notify the event loop about target events, the self-pipe trick is used
116 --- a pipe is registered as waitable event source in the event loop,
117 the event loop select/poll's on the read end of this pipe (as well on
118 other event sources, e.g., stdin), and the SIGCHLD handler writes a
119 byte to this pipe. This is more portable than relying on
120 pselect/ppoll, since on kernels that lack those syscalls, libc
121 emulates them with select/poll+sigprocmask, and that is racy
122 (a.k.a. plain broken).
124 Obviously, if we fail to notify the event loop if there's a target
125 event, it's bad. OTOH, if we notify the event loop when there's no
126 event from the target, linux_nat_wait will detect that there's no real
127 event to report, and return event of type TARGET_WAITKIND_IGNORE.
128 This is mostly harmless, but it will waste time and is better avoided.
130 The main design point is that every time GDB is outside linux-nat.c,
131 we have a SIGCHLD handler installed that is called when something
132 happens to the target and notifies the GDB event loop. Whenever GDB
133 core decides to handle the event, and calls into linux-nat.c, we
134 process things as in sync mode, except that the we never block in
137 While processing an event, we may end up momentarily blocked in
138 waitpid calls. Those waitpid calls, while blocking, are guarantied to
139 return quickly. E.g., in all-stop mode, before reporting to the core
140 that an LWP hit a breakpoint, all LWPs are stopped by sending them
141 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
142 Note that this is different from blocking indefinitely waiting for the
143 next event --- here, we're already handling an event.
148 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
149 signal is not entirely significant; we just need for a signal to be delivered,
150 so that we can intercept it. SIGSTOP's advantage is that it can not be
151 blocked. A disadvantage is that it is not a real-time signal, so it can only
152 be queued once; we do not keep track of other sources of SIGSTOP.
154 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
155 use them, because they have special behavior when the signal is generated -
156 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
157 kills the entire thread group.
159 A delivered SIGSTOP would stop the entire thread group, not just the thread we
160 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
161 cancel it (by PTRACE_CONT without passing SIGSTOP).
163 We could use a real-time signal instead. This would solve those problems; we
164 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
165 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
166 generates it, and there are races with trying to find a signal that is not
170 #define O_LARGEFILE 0
173 /* Unlike other extended result codes, WSTOPSIG (status) on
174 PTRACE_O_TRACESYSGOOD syscall events doesn't return SIGTRAP, but
175 instead SIGTRAP with bit 7 set. */
176 #define SYSCALL_SIGTRAP (SIGTRAP | 0x80)
178 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
179 the use of the multi-threaded target. */
180 static struct target_ops
*linux_ops
;
181 static struct target_ops linux_ops_saved
;
183 /* The method to call, if any, when a new thread is attached. */
184 static void (*linux_nat_new_thread
) (struct lwp_info
*);
186 /* Hook to call prior to resuming a thread. */
187 static void (*linux_nat_prepare_to_resume
) (struct lwp_info
*);
189 /* The method to call, if any, when the siginfo object needs to be
190 converted between the layout returned by ptrace, and the layout in
191 the architecture of the inferior. */
192 static int (*linux_nat_siginfo_fixup
) (siginfo_t
*,
196 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
197 Called by our to_xfer_partial. */
198 static LONGEST (*super_xfer_partial
) (struct target_ops
*,
200 const char *, gdb_byte
*,
204 static int debug_linux_nat
;
206 show_debug_linux_nat (struct ui_file
*file
, int from_tty
,
207 struct cmd_list_element
*c
, const char *value
)
209 fprintf_filtered (file
, _("Debugging of GNU/Linux lwp module is %s.\n"),
213 struct simple_pid_list
217 struct simple_pid_list
*next
;
219 struct simple_pid_list
*stopped_pids
;
221 /* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACEFORK
222 can not be used, 1 if it can. */
224 static int linux_supports_tracefork_flag
= -1;
226 /* This variable is a tri-state flag: -1 for unknown, 0 if
227 PTRACE_O_TRACESYSGOOD can not be used, 1 if it can. */
229 static int linux_supports_tracesysgood_flag
= -1;
231 /* If we have PTRACE_O_TRACEFORK, this flag indicates whether we also have
232 PTRACE_O_TRACEVFORKDONE. */
234 static int linux_supports_tracevforkdone_flag
= -1;
236 /* Stores the current used ptrace() options. */
237 static int current_ptrace_options
= 0;
239 /* Async mode support. */
241 /* The read/write ends of the pipe registered as waitable file in the
243 static int linux_nat_event_pipe
[2] = { -1, -1 };
245 /* Flush the event pipe. */
248 async_file_flush (void)
255 ret
= read (linux_nat_event_pipe
[0], &buf
, 1);
257 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
260 /* Put something (anything, doesn't matter what, or how much) in event
261 pipe, so that the select/poll in the event-loop realizes we have
262 something to process. */
265 async_file_mark (void)
269 /* It doesn't really matter what the pipe contains, as long we end
270 up with something in it. Might as well flush the previous
276 ret
= write (linux_nat_event_pipe
[1], "+", 1);
278 while (ret
== -1 && errno
== EINTR
);
280 /* Ignore EAGAIN. If the pipe is full, the event loop will already
281 be awakened anyway. */
284 static void linux_nat_async (void (*callback
)
285 (enum inferior_event_type event_type
,
288 static int kill_lwp (int lwpid
, int signo
);
290 static int stop_callback (struct lwp_info
*lp
, void *data
);
292 static void block_child_signals (sigset_t
*prev_mask
);
293 static void restore_child_signals_mask (sigset_t
*prev_mask
);
296 static struct lwp_info
*add_lwp (ptid_t ptid
);
297 static void purge_lwp_list (int pid
);
298 static void delete_lwp (ptid_t ptid
);
299 static struct lwp_info
*find_lwp_pid (ptid_t ptid
);
302 /* Trivial list manipulation functions to keep track of a list of
303 new stopped processes. */
305 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
307 struct simple_pid_list
*new_pid
= xmalloc (sizeof (struct simple_pid_list
));
310 new_pid
->status
= status
;
311 new_pid
->next
= *listp
;
316 in_pid_list_p (struct simple_pid_list
*list
, int pid
)
318 struct simple_pid_list
*p
;
320 for (p
= list
; p
!= NULL
; p
= p
->next
)
327 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *statusp
)
329 struct simple_pid_list
**p
;
331 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
332 if ((*p
)->pid
== pid
)
334 struct simple_pid_list
*next
= (*p
)->next
;
336 *statusp
= (*p
)->status
;
345 /* A helper function for linux_test_for_tracefork, called after fork (). */
348 linux_tracefork_child (void)
350 ptrace (PTRACE_TRACEME
, 0, 0, 0);
351 kill (getpid (), SIGSTOP
);
356 /* Wrapper function for waitpid which handles EINTR. */
359 my_waitpid (int pid
, int *statusp
, int flags
)
365 ret
= waitpid (pid
, statusp
, flags
);
367 while (ret
== -1 && errno
== EINTR
);
372 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events.
374 First, we try to enable fork tracing on ORIGINAL_PID. If this fails,
375 we know that the feature is not available. This may change the tracing
376 options for ORIGINAL_PID, but we'll be setting them shortly anyway.
378 However, if it succeeds, we don't know for sure that the feature is
379 available; old versions of PTRACE_SETOPTIONS ignored unknown options. We
380 create a child process, attach to it, use PTRACE_SETOPTIONS to enable
381 fork tracing, and let it fork. If the process exits, we assume that we
382 can't use TRACEFORK; if we get the fork notification, and we can extract
383 the new child's PID, then we assume that we can. */
386 linux_test_for_tracefork (int original_pid
)
388 int child_pid
, ret
, status
;
392 /* We don't want those ptrace calls to be interrupted. */
393 block_child_signals (&prev_mask
);
395 linux_supports_tracefork_flag
= 0;
396 linux_supports_tracevforkdone_flag
= 0;
398 ret
= ptrace (PTRACE_SETOPTIONS
, original_pid
, 0, PTRACE_O_TRACEFORK
);
401 restore_child_signals_mask (&prev_mask
);
407 perror_with_name (("fork"));
410 linux_tracefork_child ();
412 ret
= my_waitpid (child_pid
, &status
, 0);
414 perror_with_name (("waitpid"));
415 else if (ret
!= child_pid
)
416 error (_("linux_test_for_tracefork: waitpid: unexpected result %d."), ret
);
417 if (! WIFSTOPPED (status
))
418 error (_("linux_test_for_tracefork: waitpid: unexpected status %d."),
421 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0, PTRACE_O_TRACEFORK
);
424 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
427 warning (_("linux_test_for_tracefork: failed to kill child"));
428 restore_child_signals_mask (&prev_mask
);
432 ret
= my_waitpid (child_pid
, &status
, 0);
433 if (ret
!= child_pid
)
434 warning (_("linux_test_for_tracefork: failed "
435 "to wait for killed child"));
436 else if (!WIFSIGNALED (status
))
437 warning (_("linux_test_for_tracefork: unexpected "
438 "wait status 0x%x from killed child"), status
);
440 restore_child_signals_mask (&prev_mask
);
444 /* Check whether PTRACE_O_TRACEVFORKDONE is available. */
445 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0,
446 PTRACE_O_TRACEFORK
| PTRACE_O_TRACEVFORKDONE
);
447 linux_supports_tracevforkdone_flag
= (ret
== 0);
449 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
451 warning (_("linux_test_for_tracefork: failed to resume child"));
453 ret
= my_waitpid (child_pid
, &status
, 0);
455 if (ret
== child_pid
&& WIFSTOPPED (status
)
456 && status
>> 16 == PTRACE_EVENT_FORK
)
459 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
460 if (ret
== 0 && second_pid
!= 0)
464 linux_supports_tracefork_flag
= 1;
465 my_waitpid (second_pid
, &second_status
, 0);
466 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
468 warning (_("linux_test_for_tracefork: "
469 "failed to kill second child"));
470 my_waitpid (second_pid
, &status
, 0);
474 warning (_("linux_test_for_tracefork: unexpected result from waitpid "
475 "(%d, status 0x%x)"), ret
, status
);
477 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
479 warning (_("linux_test_for_tracefork: failed to kill child"));
480 my_waitpid (child_pid
, &status
, 0);
482 restore_child_signals_mask (&prev_mask
);
485 /* Determine if PTRACE_O_TRACESYSGOOD can be used to follow syscalls.
487 We try to enable syscall tracing on ORIGINAL_PID. If this fails,
488 we know that the feature is not available. This may change the tracing
489 options for ORIGINAL_PID, but we'll be setting them shortly anyway. */
492 linux_test_for_tracesysgood (int original_pid
)
497 /* We don't want those ptrace calls to be interrupted. */
498 block_child_signals (&prev_mask
);
500 linux_supports_tracesysgood_flag
= 0;
502 ret
= ptrace (PTRACE_SETOPTIONS
, original_pid
, 0, PTRACE_O_TRACESYSGOOD
);
506 linux_supports_tracesysgood_flag
= 1;
508 restore_child_signals_mask (&prev_mask
);
511 /* Determine wether we support PTRACE_O_TRACESYSGOOD option available.
512 This function also sets linux_supports_tracesysgood_flag. */
515 linux_supports_tracesysgood (int pid
)
517 if (linux_supports_tracesysgood_flag
== -1)
518 linux_test_for_tracesysgood (pid
);
519 return linux_supports_tracesysgood_flag
;
522 /* Return non-zero iff we have tracefork functionality available.
523 This function also sets linux_supports_tracefork_flag. */
526 linux_supports_tracefork (int pid
)
528 if (linux_supports_tracefork_flag
== -1)
529 linux_test_for_tracefork (pid
);
530 return linux_supports_tracefork_flag
;
534 linux_supports_tracevforkdone (int pid
)
536 if (linux_supports_tracefork_flag
== -1)
537 linux_test_for_tracefork (pid
);
538 return linux_supports_tracevforkdone_flag
;
542 linux_enable_tracesysgood (ptid_t ptid
)
544 int pid
= ptid_get_lwp (ptid
);
547 pid
= ptid_get_pid (ptid
);
549 if (linux_supports_tracesysgood (pid
) == 0)
552 current_ptrace_options
|= PTRACE_O_TRACESYSGOOD
;
554 ptrace (PTRACE_SETOPTIONS
, pid
, 0, current_ptrace_options
);
559 linux_enable_event_reporting (ptid_t ptid
)
561 int pid
= ptid_get_lwp (ptid
);
564 pid
= ptid_get_pid (ptid
);
566 if (! linux_supports_tracefork (pid
))
569 current_ptrace_options
|= PTRACE_O_TRACEFORK
| PTRACE_O_TRACEVFORK
570 | PTRACE_O_TRACEEXEC
| PTRACE_O_TRACECLONE
;
572 if (linux_supports_tracevforkdone (pid
))
573 current_ptrace_options
|= PTRACE_O_TRACEVFORKDONE
;
575 /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support
576 read-only process state. */
578 ptrace (PTRACE_SETOPTIONS
, pid
, 0, current_ptrace_options
);
582 linux_child_post_attach (int pid
)
584 linux_enable_event_reporting (pid_to_ptid (pid
));
585 linux_enable_tracesysgood (pid_to_ptid (pid
));
589 linux_child_post_startup_inferior (ptid_t ptid
)
591 linux_enable_event_reporting (ptid
);
592 linux_enable_tracesysgood (ptid
);
595 /* Return the number of known LWPs in the tgid given by PID. */
603 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
604 if (ptid_get_pid (lp
->ptid
) == pid
)
610 /* Call delete_lwp with prototype compatible for make_cleanup. */
613 delete_lwp_cleanup (void *lp_voidp
)
615 struct lwp_info
*lp
= lp_voidp
;
617 delete_lwp (lp
->ptid
);
621 linux_child_follow_fork (struct target_ops
*ops
, int follow_child
)
625 int parent_pid
, child_pid
;
627 block_child_signals (&prev_mask
);
629 has_vforked
= (inferior_thread ()->pending_follow
.kind
630 == TARGET_WAITKIND_VFORKED
);
631 parent_pid
= ptid_get_lwp (inferior_ptid
);
633 parent_pid
= ptid_get_pid (inferior_ptid
);
634 child_pid
= PIDGET (inferior_thread ()->pending_follow
.value
.related_pid
);
637 linux_enable_event_reporting (pid_to_ptid (child_pid
));
640 && !non_stop
/* Non-stop always resumes both branches. */
641 && (!target_is_async_p () || sync_execution
)
642 && !(follow_child
|| detach_fork
|| sched_multi
))
644 /* The parent stays blocked inside the vfork syscall until the
645 child execs or exits. If we don't let the child run, then
646 the parent stays blocked. If we're telling the parent to run
647 in the foreground, the user will not be able to ctrl-c to get
648 back the terminal, effectively hanging the debug session. */
649 fprintf_filtered (gdb_stderr
, _("\
650 Can not resume the parent process over vfork in the foreground while\n\
651 holding the child stopped. Try \"set detach-on-fork\" or \
652 \"set schedule-multiple\".\n"));
653 /* FIXME output string > 80 columns. */
659 struct lwp_info
*child_lp
= NULL
;
661 /* We're already attached to the parent, by default. */
663 /* Detach new forked process? */
666 struct cleanup
*old_chain
;
668 /* Before detaching from the child, remove all breakpoints
669 from it. If we forked, then this has already been taken
670 care of by infrun.c. If we vforked however, any
671 breakpoint inserted in the parent is visible in the
672 child, even those added while stopped in a vfork
673 catchpoint. This will remove the breakpoints from the
674 parent also, but they'll be reinserted below. */
677 /* keep breakpoints list in sync. */
678 remove_breakpoints_pid (GET_PID (inferior_ptid
));
681 if (info_verbose
|| debug_linux_nat
)
683 target_terminal_ours ();
684 fprintf_filtered (gdb_stdlog
,
685 "Detaching after fork from "
686 "child process %d.\n",
690 old_chain
= save_inferior_ptid ();
691 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
693 child_lp
= add_lwp (inferior_ptid
);
694 child_lp
->stopped
= 1;
695 child_lp
->last_resume_kind
= resume_stop
;
696 make_cleanup (delete_lwp_cleanup
, child_lp
);
698 /* CHILD_LP has new PID, therefore linux_nat_new_thread is not called for it.
699 See i386_inferior_data_get for the Linux kernel specifics.
700 Ensure linux_nat_prepare_to_resume will reset the hardware debug
701 registers. It is done by the linux_nat_new_thread call, which is
702 being skipped in add_lwp above for the first lwp of a pid. */
703 gdb_assert (num_lwps (GET_PID (child_lp
->ptid
)) == 1);
704 if (linux_nat_new_thread
!= NULL
)
705 linux_nat_new_thread (child_lp
);
707 if (linux_nat_prepare_to_resume
!= NULL
)
708 linux_nat_prepare_to_resume (child_lp
);
709 ptrace (PTRACE_DETACH
, child_pid
, 0, 0);
711 do_cleanups (old_chain
);
715 struct inferior
*parent_inf
, *child_inf
;
716 struct cleanup
*old_chain
;
718 /* Add process to GDB's tables. */
719 child_inf
= add_inferior (child_pid
);
721 parent_inf
= current_inferior ();
722 child_inf
->attach_flag
= parent_inf
->attach_flag
;
723 copy_terminal_info (child_inf
, parent_inf
);
725 old_chain
= save_inferior_ptid ();
726 save_current_program_space ();
728 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
729 add_thread (inferior_ptid
);
730 child_lp
= add_lwp (inferior_ptid
);
731 child_lp
->stopped
= 1;
732 child_lp
->last_resume_kind
= resume_stop
;
733 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
735 /* If this is a vfork child, then the address-space is
736 shared with the parent. */
739 child_inf
->pspace
= parent_inf
->pspace
;
740 child_inf
->aspace
= parent_inf
->aspace
;
742 /* The parent will be frozen until the child is done
743 with the shared region. Keep track of the
745 child_inf
->vfork_parent
= parent_inf
;
746 child_inf
->pending_detach
= 0;
747 parent_inf
->vfork_child
= child_inf
;
748 parent_inf
->pending_detach
= 0;
752 child_inf
->aspace
= new_address_space ();
753 child_inf
->pspace
= add_program_space (child_inf
->aspace
);
754 child_inf
->removable
= 1;
755 set_current_program_space (child_inf
->pspace
);
756 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
758 /* Let the shared library layer (solib-svr4) learn about
759 this new process, relocate the cloned exec, pull in
760 shared libraries, and install the solib event
761 breakpoint. If a "cloned-VM" event was propagated
762 better throughout the core, this wouldn't be
764 solib_create_inferior_hook (0);
767 /* Let the thread_db layer learn about this new process. */
768 check_for_thread_db ();
770 do_cleanups (old_chain
);
775 struct lwp_info
*parent_lp
;
776 struct inferior
*parent_inf
;
778 parent_inf
= current_inferior ();
780 /* If we detached from the child, then we have to be careful
781 to not insert breakpoints in the parent until the child
782 is done with the shared memory region. However, if we're
783 staying attached to the child, then we can and should
784 insert breakpoints, so that we can debug it. A
785 subsequent child exec or exit is enough to know when does
786 the child stops using the parent's address space. */
787 parent_inf
->waiting_for_vfork_done
= detach_fork
;
788 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
790 parent_lp
= find_lwp_pid (pid_to_ptid (parent_pid
));
791 gdb_assert (linux_supports_tracefork_flag
>= 0);
793 if (linux_supports_tracevforkdone (0))
796 fprintf_unfiltered (gdb_stdlog
,
797 "LCFF: waiting for VFORK_DONE on %d\n",
799 parent_lp
->stopped
= 1;
801 /* We'll handle the VFORK_DONE event like any other
802 event, in target_wait. */
806 /* We can't insert breakpoints until the child has
807 finished with the shared memory region. We need to
808 wait until that happens. Ideal would be to just
810 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
811 - waitpid (parent_pid, &status, __WALL);
812 However, most architectures can't handle a syscall
813 being traced on the way out if it wasn't traced on
816 We might also think to loop, continuing the child
817 until it exits or gets a SIGTRAP. One problem is
818 that the child might call ptrace with PTRACE_TRACEME.
820 There's no simple and reliable way to figure out when
821 the vforked child will be done with its copy of the
822 shared memory. We could step it out of the syscall,
823 two instructions, let it go, and then single-step the
824 parent once. When we have hardware single-step, this
825 would work; with software single-step it could still
826 be made to work but we'd have to be able to insert
827 single-step breakpoints in the child, and we'd have
828 to insert -just- the single-step breakpoint in the
829 parent. Very awkward.
831 In the end, the best we can do is to make sure it
832 runs for a little while. Hopefully it will be out of
833 range of any breakpoints we reinsert. Usually this
834 is only the single-step breakpoint at vfork's return
838 fprintf_unfiltered (gdb_stdlog
,
839 "LCFF: no VFORK_DONE "
840 "support, sleeping a bit\n");
844 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
845 and leave it pending. The next linux_nat_resume call
846 will notice a pending event, and bypasses actually
847 resuming the inferior. */
848 parent_lp
->status
= 0;
849 parent_lp
->waitstatus
.kind
= TARGET_WAITKIND_VFORK_DONE
;
850 parent_lp
->stopped
= 1;
852 /* If we're in async mode, need to tell the event loop
853 there's something here to process. */
854 if (target_can_async_p ())
861 struct inferior
*parent_inf
, *child_inf
;
862 struct lwp_info
*child_lp
;
863 struct program_space
*parent_pspace
;
865 if (info_verbose
|| debug_linux_nat
)
867 target_terminal_ours ();
869 fprintf_filtered (gdb_stdlog
,
870 _("Attaching after process %d "
871 "vfork to child process %d.\n"),
872 parent_pid
, child_pid
);
874 fprintf_filtered (gdb_stdlog
,
875 _("Attaching after process %d "
876 "fork to child process %d.\n"),
877 parent_pid
, child_pid
);
880 /* Add the new inferior first, so that the target_detach below
881 doesn't unpush the target. */
883 child_inf
= add_inferior (child_pid
);
885 parent_inf
= current_inferior ();
886 child_inf
->attach_flag
= parent_inf
->attach_flag
;
887 copy_terminal_info (child_inf
, parent_inf
);
889 parent_pspace
= parent_inf
->pspace
;
891 /* If we're vforking, we want to hold on to the parent until the
892 child exits or execs. At child exec or exit time we can
893 remove the old breakpoints from the parent and detach or
894 resume debugging it. Otherwise, detach the parent now; we'll
895 want to reuse it's program/address spaces, but we can't set
896 them to the child before removing breakpoints from the
897 parent, otherwise, the breakpoints module could decide to
898 remove breakpoints from the wrong process (since they'd be
899 assigned to the same address space). */
903 gdb_assert (child_inf
->vfork_parent
== NULL
);
904 gdb_assert (parent_inf
->vfork_child
== NULL
);
905 child_inf
->vfork_parent
= parent_inf
;
906 child_inf
->pending_detach
= 0;
907 parent_inf
->vfork_child
= child_inf
;
908 parent_inf
->pending_detach
= detach_fork
;
909 parent_inf
->waiting_for_vfork_done
= 0;
911 else if (detach_fork
)
912 target_detach (NULL
, 0);
914 /* Note that the detach above makes PARENT_INF dangling. */
916 /* Add the child thread to the appropriate lists, and switch to
917 this new thread, before cloning the program space, and
918 informing the solib layer about this new process. */
920 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
921 add_thread (inferior_ptid
);
922 child_lp
= add_lwp (inferior_ptid
);
923 child_lp
->stopped
= 1;
924 child_lp
->last_resume_kind
= resume_stop
;
926 /* If this is a vfork child, then the address-space is shared
927 with the parent. If we detached from the parent, then we can
928 reuse the parent's program/address spaces. */
929 if (has_vforked
|| detach_fork
)
931 child_inf
->pspace
= parent_pspace
;
932 child_inf
->aspace
= child_inf
->pspace
->aspace
;
936 child_inf
->aspace
= new_address_space ();
937 child_inf
->pspace
= add_program_space (child_inf
->aspace
);
938 child_inf
->removable
= 1;
939 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
940 set_current_program_space (child_inf
->pspace
);
941 clone_program_space (child_inf
->pspace
, parent_pspace
);
943 /* Let the shared library layer (solib-svr4) learn about
944 this new process, relocate the cloned exec, pull in
945 shared libraries, and install the solib event breakpoint.
946 If a "cloned-VM" event was propagated better throughout
947 the core, this wouldn't be required. */
948 solib_create_inferior_hook (0);
951 /* Let the thread_db layer learn about this new process. */
952 check_for_thread_db ();
955 restore_child_signals_mask (&prev_mask
);
961 linux_child_insert_fork_catchpoint (int pid
)
963 return !linux_supports_tracefork (pid
);
967 linux_child_remove_fork_catchpoint (int pid
)
973 linux_child_insert_vfork_catchpoint (int pid
)
975 return !linux_supports_tracefork (pid
);
979 linux_child_remove_vfork_catchpoint (int pid
)
985 linux_child_insert_exec_catchpoint (int pid
)
987 return !linux_supports_tracefork (pid
);
991 linux_child_remove_exec_catchpoint (int pid
)
997 linux_child_set_syscall_catchpoint (int pid
, int needed
, int any_count
,
998 int table_size
, int *table
)
1000 if (!linux_supports_tracesysgood (pid
))
1003 /* On GNU/Linux, we ignore the arguments. It means that we only
1004 enable the syscall catchpoints, but do not disable them.
1006 Also, we do not use the `table' information because we do not
1007 filter system calls here. We let GDB do the logic for us. */
1011 /* On GNU/Linux there are no real LWP's. The closest thing to LWP's
1012 are processes sharing the same VM space. A multi-threaded process
1013 is basically a group of such processes. However, such a grouping
1014 is almost entirely a user-space issue; the kernel doesn't enforce
1015 such a grouping at all (this might change in the future). In
1016 general, we'll rely on the threads library (i.e. the GNU/Linux
1017 Threads library) to provide such a grouping.
1019 It is perfectly well possible to write a multi-threaded application
1020 without the assistance of a threads library, by using the clone
1021 system call directly. This module should be able to give some
1022 rudimentary support for debugging such applications if developers
1023 specify the CLONE_PTRACE flag in the clone system call, and are
1024 using the Linux kernel 2.4 or above.
1026 Note that there are some peculiarities in GNU/Linux that affect
1029 - In general one should specify the __WCLONE flag to waitpid in
1030 order to make it report events for any of the cloned processes
1031 (and leave it out for the initial process). However, if a cloned
1032 process has exited the exit status is only reported if the
1033 __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
1034 we cannot use it since GDB must work on older systems too.
1036 - When a traced, cloned process exits and is waited for by the
1037 debugger, the kernel reassigns it to the original parent and
1038 keeps it around as a "zombie". Somehow, the GNU/Linux Threads
1039 library doesn't notice this, which leads to the "zombie problem":
1040 When debugged a multi-threaded process that spawns a lot of
1041 threads will run out of processes, even if the threads exit,
1042 because the "zombies" stay around. */
1044 /* List of known LWPs. */
1045 struct lwp_info
*lwp_list
;
1048 /* Original signal mask. */
1049 static sigset_t normal_mask
;
1051 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
1052 _initialize_linux_nat. */
1053 static sigset_t suspend_mask
;
1055 /* Signals to block to make that sigsuspend work. */
1056 static sigset_t blocked_mask
;
1058 /* SIGCHLD action. */
1059 struct sigaction sigchld_action
;
1061 /* Block child signals (SIGCHLD and linux threads signals), and store
1062 the previous mask in PREV_MASK. */
1065 block_child_signals (sigset_t
*prev_mask
)
1067 /* Make sure SIGCHLD is blocked. */
1068 if (!sigismember (&blocked_mask
, SIGCHLD
))
1069 sigaddset (&blocked_mask
, SIGCHLD
);
1071 sigprocmask (SIG_BLOCK
, &blocked_mask
, prev_mask
);
1074 /* Restore child signals mask, previously returned by
1075 block_child_signals. */
1078 restore_child_signals_mask (sigset_t
*prev_mask
)
1080 sigprocmask (SIG_SETMASK
, prev_mask
, NULL
);
1083 /* Mask of signals to pass directly to the inferior. */
1084 static sigset_t pass_mask
;
1086 /* Update signals to pass to the inferior. */
1088 linux_nat_pass_signals (int numsigs
, unsigned char *pass_signals
)
1092 sigemptyset (&pass_mask
);
1094 for (signo
= 1; signo
< NSIG
; signo
++)
1096 int target_signo
= gdb_signal_from_host (signo
);
1097 if (target_signo
< numsigs
&& pass_signals
[target_signo
])
1098 sigaddset (&pass_mask
, signo
);
1104 /* Prototypes for local functions. */
1105 static int stop_wait_callback (struct lwp_info
*lp
, void *data
);
1106 static int linux_thread_alive (ptid_t ptid
);
1107 static char *linux_child_pid_to_exec_file (int pid
);
1110 /* Convert wait status STATUS to a string. Used for printing debug
1114 status_to_str (int status
)
1116 static char buf
[64];
1118 if (WIFSTOPPED (status
))
1120 if (WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
1121 snprintf (buf
, sizeof (buf
), "%s (stopped at syscall)",
1122 strsignal (SIGTRAP
));
1124 snprintf (buf
, sizeof (buf
), "%s (stopped)",
1125 strsignal (WSTOPSIG (status
)));
1127 else if (WIFSIGNALED (status
))
1128 snprintf (buf
, sizeof (buf
), "%s (terminated)",
1129 strsignal (WTERMSIG (status
)));
1131 snprintf (buf
, sizeof (buf
), "%d (exited)", WEXITSTATUS (status
));
1136 /* Destroy and free LP. */
1139 lwp_free (struct lwp_info
*lp
)
1141 xfree (lp
->arch_private
);
1145 /* Remove all LWPs belong to PID from the lwp list. */
1148 purge_lwp_list (int pid
)
1150 struct lwp_info
*lp
, *lpprev
, *lpnext
;
1154 for (lp
= lwp_list
; lp
; lp
= lpnext
)
1158 if (ptid_get_pid (lp
->ptid
) == pid
)
1161 lwp_list
= lp
->next
;
1163 lpprev
->next
= lp
->next
;
1172 /* Add the LWP specified by PID to the list. Return a pointer to the
1173 structure describing the new LWP. The LWP should already be stopped
1174 (with an exception for the very first LWP). */
1176 static struct lwp_info
*
1177 add_lwp (ptid_t ptid
)
1179 struct lwp_info
*lp
;
1181 gdb_assert (is_lwp (ptid
));
1183 lp
= (struct lwp_info
*) xmalloc (sizeof (struct lwp_info
));
1185 memset (lp
, 0, sizeof (struct lwp_info
));
1187 lp
->last_resume_kind
= resume_continue
;
1188 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
1193 lp
->next
= lwp_list
;
1196 /* Let the arch specific bits know about this new thread. Current
1197 clients of this callback take the opportunity to install
1198 watchpoints in the new thread. Don't do this for the first
1199 thread though. If we're spawning a child ("run"), the thread
1200 executes the shell wrapper first, and we shouldn't touch it until
1201 it execs the program we want to debug. For "attach", it'd be
1202 okay to call the callback, but it's not necessary, because
1203 watchpoints can't yet have been inserted into the inferior. */
1204 if (num_lwps (GET_PID (ptid
)) > 1 && linux_nat_new_thread
!= NULL
)
1205 linux_nat_new_thread (lp
);
1210 /* Remove the LWP specified by PID from the list. */
1213 delete_lwp (ptid_t ptid
)
1215 struct lwp_info
*lp
, *lpprev
;
1219 for (lp
= lwp_list
; lp
; lpprev
= lp
, lp
= lp
->next
)
1220 if (ptid_equal (lp
->ptid
, ptid
))
1227 lpprev
->next
= lp
->next
;
1229 lwp_list
= lp
->next
;
1234 /* Return a pointer to the structure describing the LWP corresponding
1235 to PID. If no corresponding LWP could be found, return NULL. */
1237 static struct lwp_info
*
1238 find_lwp_pid (ptid_t ptid
)
1240 struct lwp_info
*lp
;
1244 lwp
= GET_LWP (ptid
);
1246 lwp
= GET_PID (ptid
);
1248 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
1249 if (lwp
== GET_LWP (lp
->ptid
))
1255 /* Call CALLBACK with its second argument set to DATA for every LWP in
1256 the list. If CALLBACK returns 1 for a particular LWP, return a
1257 pointer to the structure describing that LWP immediately.
1258 Otherwise return NULL. */
1261 iterate_over_lwps (ptid_t filter
,
1262 int (*callback
) (struct lwp_info
*, void *),
1265 struct lwp_info
*lp
, *lpnext
;
1267 for (lp
= lwp_list
; lp
; lp
= lpnext
)
1271 if (ptid_match (lp
->ptid
, filter
))
1273 if ((*callback
) (lp
, data
))
1281 /* Iterate like iterate_over_lwps does except when forking-off a child call
1282 CALLBACK with CALLBACK_DATA specifically only for that new child PID. */
1285 linux_nat_iterate_watchpoint_lwps
1286 (linux_nat_iterate_watchpoint_lwps_ftype callback
, void *callback_data
)
1288 int inferior_pid
= ptid_get_pid (inferior_ptid
);
1289 struct inferior
*inf
= current_inferior ();
1291 if (inf
->pid
== inferior_pid
)
1293 /* Iterate all the threads of the current inferior. Without specifying
1294 INFERIOR_PID it would iterate all threads of all inferiors, which is
1295 inappropriate for watchpoints. */
1297 iterate_over_lwps (pid_to_ptid (inferior_pid
), callback
, callback_data
);
1301 /* Detaching a new child PID temporarily present in INFERIOR_PID. */
1303 struct lwp_info
*child_lp
;
1304 struct cleanup
*old_chain
;
1305 pid_t child_pid
= GET_PID (inferior_ptid
);
1306 ptid_t child_ptid
= ptid_build (child_pid
, child_pid
, 0);
1308 gdb_assert (!is_lwp (inferior_ptid
));
1309 gdb_assert (find_lwp_pid (child_ptid
) == NULL
);
1310 child_lp
= add_lwp (child_ptid
);
1311 child_lp
->stopped
= 1;
1312 child_lp
->last_resume_kind
= resume_stop
;
1313 old_chain
= make_cleanup (delete_lwp_cleanup
, child_lp
);
1315 callback (child_lp
, callback_data
);
1317 do_cleanups (old_chain
);
1321 /* Update our internal state when changing from one checkpoint to
1322 another indicated by NEW_PTID. We can only switch single-threaded
1323 applications, so we only create one new LWP, and the previous list
1327 linux_nat_switch_fork (ptid_t new_ptid
)
1329 struct lwp_info
*lp
;
1331 purge_lwp_list (GET_PID (inferior_ptid
));
1333 lp
= add_lwp (new_ptid
);
1336 /* This changes the thread's ptid while preserving the gdb thread
1337 num. Also changes the inferior pid, while preserving the
1339 thread_change_ptid (inferior_ptid
, new_ptid
);
1341 /* We've just told GDB core that the thread changed target id, but,
1342 in fact, it really is a different thread, with different register
1344 registers_changed ();
1347 /* Handle the exit of a single thread LP. */
1350 exit_lwp (struct lwp_info
*lp
)
1352 struct thread_info
*th
= find_thread_ptid (lp
->ptid
);
1356 if (print_thread_events
)
1357 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp
->ptid
));
1359 delete_thread (lp
->ptid
);
1362 delete_lwp (lp
->ptid
);
1365 /* Wait for the LWP specified by LP, which we have just attached to.
1366 Returns a wait status for that LWP, to cache. */
1369 linux_nat_post_attach_wait (ptid_t ptid
, int first
, int *cloned
,
1372 pid_t new_pid
, pid
= GET_LWP (ptid
);
1375 if (linux_proc_pid_is_stopped (pid
))
1377 if (debug_linux_nat
)
1378 fprintf_unfiltered (gdb_stdlog
,
1379 "LNPAW: Attaching to a stopped process\n");
1381 /* The process is definitely stopped. It is in a job control
1382 stop, unless the kernel predates the TASK_STOPPED /
1383 TASK_TRACED distinction, in which case it might be in a
1384 ptrace stop. Make sure it is in a ptrace stop; from there we
1385 can kill it, signal it, et cetera.
1387 First make sure there is a pending SIGSTOP. Since we are
1388 already attached, the process can not transition from stopped
1389 to running without a PTRACE_CONT; so we know this signal will
1390 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1391 probably already in the queue (unless this kernel is old
1392 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1393 is not an RT signal, it can only be queued once. */
1394 kill_lwp (pid
, SIGSTOP
);
1396 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1397 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1398 ptrace (PTRACE_CONT
, pid
, 0, 0);
1401 /* Make sure the initial process is stopped. The user-level threads
1402 layer might want to poke around in the inferior, and that won't
1403 work if things haven't stabilized yet. */
1404 new_pid
= my_waitpid (pid
, &status
, 0);
1405 if (new_pid
== -1 && errno
== ECHILD
)
1408 warning (_("%s is a cloned process"), target_pid_to_str (ptid
));
1410 /* Try again with __WCLONE to check cloned processes. */
1411 new_pid
= my_waitpid (pid
, &status
, __WCLONE
);
1415 gdb_assert (pid
== new_pid
);
1417 if (!WIFSTOPPED (status
))
1419 /* The pid we tried to attach has apparently just exited. */
1420 if (debug_linux_nat
)
1421 fprintf_unfiltered (gdb_stdlog
, "LNPAW: Failed to stop %d: %s",
1422 pid
, status_to_str (status
));
1426 if (WSTOPSIG (status
) != SIGSTOP
)
1429 if (debug_linux_nat
)
1430 fprintf_unfiltered (gdb_stdlog
,
1431 "LNPAW: Received %s after attaching\n",
1432 status_to_str (status
));
1438 /* Attach to the LWP specified by PID. Return 0 if successful, -1 if
1439 the new LWP could not be attached, or 1 if we're already auto
1440 attached to this thread, but haven't processed the
1441 PTRACE_EVENT_CLONE event of its parent thread, so we just ignore
1442 its existance, without considering it an error. */
1445 lin_lwp_attach_lwp (ptid_t ptid
)
1447 struct lwp_info
*lp
;
1451 gdb_assert (is_lwp (ptid
));
1453 block_child_signals (&prev_mask
);
1455 lp
= find_lwp_pid (ptid
);
1456 lwpid
= GET_LWP (ptid
);
1458 /* We assume that we're already attached to any LWP that has an id
1459 equal to the overall process id, and to any LWP that is already
1460 in our list of LWPs. If we're not seeing exit events from threads
1461 and we've had PID wraparound since we last tried to stop all threads,
1462 this assumption might be wrong; fortunately, this is very unlikely
1464 if (lwpid
!= GET_PID (ptid
) && lp
== NULL
)
1466 int status
, cloned
= 0, signalled
= 0;
1468 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) < 0)
1470 if (linux_supports_tracefork_flag
)
1472 /* If we haven't stopped all threads when we get here,
1473 we may have seen a thread listed in thread_db's list,
1474 but not processed the PTRACE_EVENT_CLONE yet. If
1475 that's the case, ignore this new thread, and let
1476 normal event handling discover it later. */
1477 if (in_pid_list_p (stopped_pids
, lwpid
))
1479 /* We've already seen this thread stop, but we
1480 haven't seen the PTRACE_EVENT_CLONE extended
1482 restore_child_signals_mask (&prev_mask
);
1490 /* See if we've got a stop for this new child
1491 pending. If so, we're already attached. */
1492 new_pid
= my_waitpid (lwpid
, &status
, WNOHANG
);
1493 if (new_pid
== -1 && errno
== ECHILD
)
1494 new_pid
= my_waitpid (lwpid
, &status
, __WCLONE
| WNOHANG
);
1497 if (WIFSTOPPED (status
))
1498 add_to_pid_list (&stopped_pids
, lwpid
, status
);
1500 restore_child_signals_mask (&prev_mask
);
1506 /* If we fail to attach to the thread, issue a warning,
1507 but continue. One way this can happen is if thread
1508 creation is interrupted; as of Linux kernel 2.6.19, a
1509 bug may place threads in the thread list and then fail
1511 warning (_("Can't attach %s: %s"), target_pid_to_str (ptid
),
1512 safe_strerror (errno
));
1513 restore_child_signals_mask (&prev_mask
);
1517 if (debug_linux_nat
)
1518 fprintf_unfiltered (gdb_stdlog
,
1519 "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
1520 target_pid_to_str (ptid
));
1522 status
= linux_nat_post_attach_wait (ptid
, 0, &cloned
, &signalled
);
1523 if (!WIFSTOPPED (status
))
1525 restore_child_signals_mask (&prev_mask
);
1529 lp
= add_lwp (ptid
);
1531 lp
->cloned
= cloned
;
1532 lp
->signalled
= signalled
;
1533 if (WSTOPSIG (status
) != SIGSTOP
)
1536 lp
->status
= status
;
1539 target_post_attach (GET_LWP (lp
->ptid
));
1541 if (debug_linux_nat
)
1543 fprintf_unfiltered (gdb_stdlog
,
1544 "LLAL: waitpid %s received %s\n",
1545 target_pid_to_str (ptid
),
1546 status_to_str (status
));
1551 /* We assume that the LWP representing the original process is
1552 already stopped. Mark it as stopped in the data structure
1553 that the GNU/linux ptrace layer uses to keep track of
1554 threads. Note that this won't have already been done since
1555 the main thread will have, we assume, been stopped by an
1556 attach from a different layer. */
1558 lp
= add_lwp (ptid
);
1562 lp
->last_resume_kind
= resume_stop
;
1563 restore_child_signals_mask (&prev_mask
);
1568 linux_nat_create_inferior (struct target_ops
*ops
,
1569 char *exec_file
, char *allargs
, char **env
,
1572 #ifdef HAVE_PERSONALITY
1573 int personality_orig
= 0, personality_set
= 0;
1574 #endif /* HAVE_PERSONALITY */
1576 /* The fork_child mechanism is synchronous and calls target_wait, so
1577 we have to mask the async mode. */
1579 #ifdef HAVE_PERSONALITY
1580 if (disable_randomization
)
1583 personality_orig
= personality (0xffffffff);
1584 if (errno
== 0 && !(personality_orig
& ADDR_NO_RANDOMIZE
))
1586 personality_set
= 1;
1587 personality (personality_orig
| ADDR_NO_RANDOMIZE
);
1589 if (errno
!= 0 || (personality_set
1590 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE
)))
1591 warning (_("Error disabling address space randomization: %s"),
1592 safe_strerror (errno
));
1594 #endif /* HAVE_PERSONALITY */
1596 /* Make sure we report all signals during startup. */
1597 linux_nat_pass_signals (0, NULL
);
1599 linux_ops
->to_create_inferior (ops
, exec_file
, allargs
, env
, from_tty
);
1601 #ifdef HAVE_PERSONALITY
1602 if (personality_set
)
1605 personality (personality_orig
);
1607 warning (_("Error restoring address space randomization: %s"),
1608 safe_strerror (errno
));
1610 #endif /* HAVE_PERSONALITY */
1614 linux_nat_attach (struct target_ops
*ops
, char *args
, int from_tty
)
1616 struct lwp_info
*lp
;
1619 volatile struct gdb_exception ex
;
1621 /* Make sure we report all signals during attach. */
1622 linux_nat_pass_signals (0, NULL
);
1624 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
1626 linux_ops
->to_attach (ops
, args
, from_tty
);
1630 pid_t pid
= parse_pid_to_attach (args
);
1631 struct buffer buffer
;
1632 char *message
, *buffer_s
;
1634 message
= xstrdup (ex
.message
);
1635 make_cleanup (xfree
, message
);
1637 buffer_init (&buffer
);
1638 linux_ptrace_attach_warnings (pid
, &buffer
);
1640 buffer_grow_str0 (&buffer
, "");
1641 buffer_s
= buffer_finish (&buffer
);
1642 make_cleanup (xfree
, buffer_s
);
1644 throw_error (ex
.error
, "%s%s", buffer_s
, message
);
1647 /* The ptrace base target adds the main thread with (pid,0,0)
1648 format. Decorate it with lwp info. */
1649 ptid
= BUILD_LWP (GET_PID (inferior_ptid
), GET_PID (inferior_ptid
));
1650 thread_change_ptid (inferior_ptid
, ptid
);
1652 /* Add the initial process as the first LWP to the list. */
1653 lp
= add_lwp (ptid
);
1655 status
= linux_nat_post_attach_wait (lp
->ptid
, 1, &lp
->cloned
,
1657 if (!WIFSTOPPED (status
))
1659 if (WIFEXITED (status
))
1661 int exit_code
= WEXITSTATUS (status
);
1663 target_terminal_ours ();
1664 target_mourn_inferior ();
1666 error (_("Unable to attach: program exited normally."));
1668 error (_("Unable to attach: program exited with code %d."),
1671 else if (WIFSIGNALED (status
))
1673 enum gdb_signal signo
;
1675 target_terminal_ours ();
1676 target_mourn_inferior ();
1678 signo
= gdb_signal_from_host (WTERMSIG (status
));
1679 error (_("Unable to attach: program terminated with signal "
1681 gdb_signal_to_name (signo
),
1682 gdb_signal_to_string (signo
));
1685 internal_error (__FILE__
, __LINE__
,
1686 _("unexpected status %d for PID %ld"),
1687 status
, (long) GET_LWP (ptid
));
1692 /* Save the wait status to report later. */
1694 if (debug_linux_nat
)
1695 fprintf_unfiltered (gdb_stdlog
,
1696 "LNA: waitpid %ld, saving status %s\n",
1697 (long) GET_PID (lp
->ptid
), status_to_str (status
));
1699 lp
->status
= status
;
1701 if (target_can_async_p ())
1702 target_async (inferior_event_handler
, 0);
1705 /* Get pending status of LP. */
1707 get_pending_status (struct lwp_info
*lp
, int *status
)
1709 enum gdb_signal signo
= GDB_SIGNAL_0
;
1711 /* If we paused threads momentarily, we may have stored pending
1712 events in lp->status or lp->waitstatus (see stop_wait_callback),
1713 and GDB core hasn't seen any signal for those threads.
1714 Otherwise, the last signal reported to the core is found in the
1715 thread object's stop_signal.
1717 There's a corner case that isn't handled here at present. Only
1718 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1719 stop_signal make sense as a real signal to pass to the inferior.
1720 Some catchpoint related events, like
1721 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1722 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1723 those traps are debug API (ptrace in our case) related and
1724 induced; the inferior wouldn't see them if it wasn't being
1725 traced. Hence, we should never pass them to the inferior, even
1726 when set to pass state. Since this corner case isn't handled by
1727 infrun.c when proceeding with a signal, for consistency, neither
1728 do we handle it here (or elsewhere in the file we check for
1729 signal pass state). Normally SIGTRAP isn't set to pass state, so
1730 this is really a corner case. */
1732 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
1733 signo
= GDB_SIGNAL_0
; /* a pending ptrace event, not a real signal. */
1734 else if (lp
->status
)
1735 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1736 else if (non_stop
&& !is_executing (lp
->ptid
))
1738 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1740 signo
= tp
->suspend
.stop_signal
;
1744 struct target_waitstatus last
;
1747 get_last_target_status (&last_ptid
, &last
);
1749 if (GET_LWP (lp
->ptid
) == GET_LWP (last_ptid
))
1751 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1753 signo
= tp
->suspend
.stop_signal
;
1759 if (signo
== GDB_SIGNAL_0
)
1761 if (debug_linux_nat
)
1762 fprintf_unfiltered (gdb_stdlog
,
1763 "GPT: lwp %s has no pending signal\n",
1764 target_pid_to_str (lp
->ptid
));
1766 else if (!signal_pass_state (signo
))
1768 if (debug_linux_nat
)
1769 fprintf_unfiltered (gdb_stdlog
,
1770 "GPT: lwp %s had signal %s, "
1771 "but it is in no pass state\n",
1772 target_pid_to_str (lp
->ptid
),
1773 gdb_signal_to_string (signo
));
1777 *status
= W_STOPCODE (gdb_signal_to_host (signo
));
1779 if (debug_linux_nat
)
1780 fprintf_unfiltered (gdb_stdlog
,
1781 "GPT: lwp %s has pending signal %s\n",
1782 target_pid_to_str (lp
->ptid
),
1783 gdb_signal_to_string (signo
));
1790 detach_callback (struct lwp_info
*lp
, void *data
)
1792 gdb_assert (lp
->status
== 0 || WIFSTOPPED (lp
->status
));
1794 if (debug_linux_nat
&& lp
->status
)
1795 fprintf_unfiltered (gdb_stdlog
, "DC: Pending %s for %s on detach.\n",
1796 strsignal (WSTOPSIG (lp
->status
)),
1797 target_pid_to_str (lp
->ptid
));
1799 /* If there is a pending SIGSTOP, get rid of it. */
1802 if (debug_linux_nat
)
1803 fprintf_unfiltered (gdb_stdlog
,
1804 "DC: Sending SIGCONT to %s\n",
1805 target_pid_to_str (lp
->ptid
));
1807 kill_lwp (GET_LWP (lp
->ptid
), SIGCONT
);
1811 /* We don't actually detach from the LWP that has an id equal to the
1812 overall process id just yet. */
1813 if (GET_LWP (lp
->ptid
) != GET_PID (lp
->ptid
))
1817 /* Pass on any pending signal for this LWP. */
1818 get_pending_status (lp
, &status
);
1820 if (linux_nat_prepare_to_resume
!= NULL
)
1821 linux_nat_prepare_to_resume (lp
);
1823 if (ptrace (PTRACE_DETACH
, GET_LWP (lp
->ptid
), 0,
1824 WSTOPSIG (status
)) < 0)
1825 error (_("Can't detach %s: %s"), target_pid_to_str (lp
->ptid
),
1826 safe_strerror (errno
));
1828 if (debug_linux_nat
)
1829 fprintf_unfiltered (gdb_stdlog
,
1830 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1831 target_pid_to_str (lp
->ptid
),
1832 strsignal (WSTOPSIG (status
)));
1834 delete_lwp (lp
->ptid
);
1841 linux_nat_detach (struct target_ops
*ops
, char *args
, int from_tty
)
1845 struct lwp_info
*main_lwp
;
1847 pid
= GET_PID (inferior_ptid
);
1849 if (target_can_async_p ())
1850 linux_nat_async (NULL
, 0);
1852 /* Stop all threads before detaching. ptrace requires that the
1853 thread is stopped to sucessfully detach. */
1854 iterate_over_lwps (pid_to_ptid (pid
), stop_callback
, NULL
);
1855 /* ... and wait until all of them have reported back that
1856 they're no longer running. */
1857 iterate_over_lwps (pid_to_ptid (pid
), stop_wait_callback
, NULL
);
1859 iterate_over_lwps (pid_to_ptid (pid
), detach_callback
, NULL
);
1861 /* Only the initial process should be left right now. */
1862 gdb_assert (num_lwps (GET_PID (inferior_ptid
)) == 1);
1864 main_lwp
= find_lwp_pid (pid_to_ptid (pid
));
1866 /* Pass on any pending signal for the last LWP. */
1867 if ((args
== NULL
|| *args
== '\0')
1868 && get_pending_status (main_lwp
, &status
) != -1
1869 && WIFSTOPPED (status
))
1871 /* Put the signal number in ARGS so that inf_ptrace_detach will
1872 pass it along with PTRACE_DETACH. */
1874 sprintf (args
, "%d", (int) WSTOPSIG (status
));
1875 if (debug_linux_nat
)
1876 fprintf_unfiltered (gdb_stdlog
,
1877 "LND: Sending signal %s to %s\n",
1879 target_pid_to_str (main_lwp
->ptid
));
1882 if (linux_nat_prepare_to_resume
!= NULL
)
1883 linux_nat_prepare_to_resume (main_lwp
);
1884 delete_lwp (main_lwp
->ptid
);
1886 if (forks_exist_p ())
1888 /* Multi-fork case. The current inferior_ptid is being detached
1889 from, but there are other viable forks to debug. Detach from
1890 the current fork, and context-switch to the first
1892 linux_fork_detach (args
, from_tty
);
1894 if (non_stop
&& target_can_async_p ())
1895 target_async (inferior_event_handler
, 0);
1898 linux_ops
->to_detach (ops
, args
, from_tty
);
1904 resume_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1908 struct inferior
*inf
= find_inferior_pid (GET_PID (lp
->ptid
));
1910 if (inf
->vfork_child
!= NULL
)
1912 if (debug_linux_nat
)
1913 fprintf_unfiltered (gdb_stdlog
,
1914 "RC: Not resuming %s (vfork parent)\n",
1915 target_pid_to_str (lp
->ptid
));
1917 else if (lp
->status
== 0
1918 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
1920 if (debug_linux_nat
)
1921 fprintf_unfiltered (gdb_stdlog
,
1922 "RC: Resuming sibling %s, %s, %s\n",
1923 target_pid_to_str (lp
->ptid
),
1924 (signo
!= GDB_SIGNAL_0
1925 ? strsignal (gdb_signal_to_host (signo
))
1927 step
? "step" : "resume");
1929 if (linux_nat_prepare_to_resume
!= NULL
)
1930 linux_nat_prepare_to_resume (lp
);
1931 linux_ops
->to_resume (linux_ops
,
1932 pid_to_ptid (GET_LWP (lp
->ptid
)),
1936 lp
->stopped_by_watchpoint
= 0;
1940 if (debug_linux_nat
)
1941 fprintf_unfiltered (gdb_stdlog
,
1942 "RC: Not resuming sibling %s (has pending)\n",
1943 target_pid_to_str (lp
->ptid
));
1948 if (debug_linux_nat
)
1949 fprintf_unfiltered (gdb_stdlog
,
1950 "RC: Not resuming sibling %s (not stopped)\n",
1951 target_pid_to_str (lp
->ptid
));
1955 /* Resume LWP, with the last stop signal, if it is in pass state. */
1958 linux_nat_resume_callback (struct lwp_info
*lp
, void *data
)
1960 enum gdb_signal signo
= GDB_SIGNAL_0
;
1964 struct thread_info
*thread
;
1966 thread
= find_thread_ptid (lp
->ptid
);
1969 if (signal_pass_state (thread
->suspend
.stop_signal
))
1970 signo
= thread
->suspend
.stop_signal
;
1971 thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
1975 resume_lwp (lp
, 0, signo
);
1980 resume_clear_callback (struct lwp_info
*lp
, void *data
)
1983 lp
->last_resume_kind
= resume_stop
;
1988 resume_set_callback (struct lwp_info
*lp
, void *data
)
1991 lp
->last_resume_kind
= resume_continue
;
1996 linux_nat_resume (struct target_ops
*ops
,
1997 ptid_t ptid
, int step
, enum gdb_signal signo
)
2000 struct lwp_info
*lp
;
2003 if (debug_linux_nat
)
2004 fprintf_unfiltered (gdb_stdlog
,
2005 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
2006 step
? "step" : "resume",
2007 target_pid_to_str (ptid
),
2008 (signo
!= GDB_SIGNAL_0
2009 ? strsignal (gdb_signal_to_host (signo
)) : "0"),
2010 target_pid_to_str (inferior_ptid
));
2012 block_child_signals (&prev_mask
);
2014 /* A specific PTID means `step only this process id'. */
2015 resume_many
= (ptid_equal (minus_one_ptid
, ptid
)
2016 || ptid_is_pid (ptid
));
2018 /* Mark the lwps we're resuming as resumed. */
2019 iterate_over_lwps (ptid
, resume_set_callback
, NULL
);
2021 /* See if it's the current inferior that should be handled
2024 lp
= find_lwp_pid (inferior_ptid
);
2026 lp
= find_lwp_pid (ptid
);
2027 gdb_assert (lp
!= NULL
);
2029 /* Remember if we're stepping. */
2031 lp
->last_resume_kind
= step
? resume_step
: resume_continue
;
2033 /* If we have a pending wait status for this thread, there is no
2034 point in resuming the process. But first make sure that
2035 linux_nat_wait won't preemptively handle the event - we
2036 should never take this short-circuit if we are going to
2037 leave LP running, since we have skipped resuming all the
2038 other threads. This bit of code needs to be synchronized
2039 with linux_nat_wait. */
2041 if (lp
->status
&& WIFSTOPPED (lp
->status
))
2044 && WSTOPSIG (lp
->status
)
2045 && sigismember (&pass_mask
, WSTOPSIG (lp
->status
)))
2047 if (debug_linux_nat
)
2048 fprintf_unfiltered (gdb_stdlog
,
2049 "LLR: Not short circuiting for ignored "
2050 "status 0x%x\n", lp
->status
);
2052 /* FIXME: What should we do if we are supposed to continue
2053 this thread with a signal? */
2054 gdb_assert (signo
== GDB_SIGNAL_0
);
2055 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
2060 if (lp
->status
|| lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
2062 /* FIXME: What should we do if we are supposed to continue
2063 this thread with a signal? */
2064 gdb_assert (signo
== GDB_SIGNAL_0
);
2066 if (debug_linux_nat
)
2067 fprintf_unfiltered (gdb_stdlog
,
2068 "LLR: Short circuiting for status 0x%x\n",
2071 restore_child_signals_mask (&prev_mask
);
2072 if (target_can_async_p ())
2074 target_async (inferior_event_handler
, 0);
2075 /* Tell the event loop we have something to process. */
2081 /* Mark LWP as not stopped to prevent it from being continued by
2082 linux_nat_resume_callback. */
2086 iterate_over_lwps (ptid
, linux_nat_resume_callback
, NULL
);
2088 /* Convert to something the lower layer understands. */
2089 ptid
= pid_to_ptid (GET_LWP (lp
->ptid
));
2091 if (linux_nat_prepare_to_resume
!= NULL
)
2092 linux_nat_prepare_to_resume (lp
);
2093 linux_ops
->to_resume (linux_ops
, ptid
, step
, signo
);
2094 lp
->stopped_by_watchpoint
= 0;
2096 if (debug_linux_nat
)
2097 fprintf_unfiltered (gdb_stdlog
,
2098 "LLR: %s %s, %s (resume event thread)\n",
2099 step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2100 target_pid_to_str (ptid
),
2101 (signo
!= GDB_SIGNAL_0
2102 ? strsignal (gdb_signal_to_host (signo
)) : "0"));
2104 restore_child_signals_mask (&prev_mask
);
2105 if (target_can_async_p ())
2106 target_async (inferior_event_handler
, 0);
2109 /* Send a signal to an LWP. */
2112 kill_lwp (int lwpid
, int signo
)
2114 /* Use tkill, if possible, in case we are using nptl threads. If tkill
2115 fails, then we are not using nptl threads and we should be using kill. */
2117 #ifdef HAVE_TKILL_SYSCALL
2119 static int tkill_failed
;
2126 ret
= syscall (__NR_tkill
, lwpid
, signo
);
2127 if (errno
!= ENOSYS
)
2134 return kill (lwpid
, signo
);
2137 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
2138 event, check if the core is interested in it: if not, ignore the
2139 event, and keep waiting; otherwise, we need to toggle the LWP's
2140 syscall entry/exit status, since the ptrace event itself doesn't
2141 indicate it, and report the trap to higher layers. */
2144 linux_handle_syscall_trap (struct lwp_info
*lp
, int stopping
)
2146 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
2147 struct gdbarch
*gdbarch
= target_thread_architecture (lp
->ptid
);
2148 int syscall_number
= (int) gdbarch_get_syscall_number (gdbarch
, lp
->ptid
);
2152 /* If we're stopping threads, there's a SIGSTOP pending, which
2153 makes it so that the LWP reports an immediate syscall return,
2154 followed by the SIGSTOP. Skip seeing that "return" using
2155 PTRACE_CONT directly, and let stop_wait_callback collect the
2156 SIGSTOP. Later when the thread is resumed, a new syscall
2157 entry event. If we didn't do this (and returned 0), we'd
2158 leave a syscall entry pending, and our caller, by using
2159 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
2160 itself. Later, when the user re-resumes this LWP, we'd see
2161 another syscall entry event and we'd mistake it for a return.
2163 If stop_wait_callback didn't force the SIGSTOP out of the LWP
2164 (leaving immediately with LWP->signalled set, without issuing
2165 a PTRACE_CONT), it would still be problematic to leave this
2166 syscall enter pending, as later when the thread is resumed,
2167 it would then see the same syscall exit mentioned above,
2168 followed by the delayed SIGSTOP, while the syscall didn't
2169 actually get to execute. It seems it would be even more
2170 confusing to the user. */
2172 if (debug_linux_nat
)
2173 fprintf_unfiltered (gdb_stdlog
,
2174 "LHST: ignoring syscall %d "
2175 "for LWP %ld (stopping threads), "
2176 "resuming with PTRACE_CONT for SIGSTOP\n",
2178 GET_LWP (lp
->ptid
));
2180 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2181 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2185 if (catch_syscall_enabled ())
2187 /* Always update the entry/return state, even if this particular
2188 syscall isn't interesting to the core now. In async mode,
2189 the user could install a new catchpoint for this syscall
2190 between syscall enter/return, and we'll need to know to
2191 report a syscall return if that happens. */
2192 lp
->syscall_state
= (lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
2193 ? TARGET_WAITKIND_SYSCALL_RETURN
2194 : TARGET_WAITKIND_SYSCALL_ENTRY
);
2196 if (catching_syscall_number (syscall_number
))
2198 /* Alright, an event to report. */
2199 ourstatus
->kind
= lp
->syscall_state
;
2200 ourstatus
->value
.syscall_number
= syscall_number
;
2202 if (debug_linux_nat
)
2203 fprintf_unfiltered (gdb_stdlog
,
2204 "LHST: stopping for %s of syscall %d"
2207 == TARGET_WAITKIND_SYSCALL_ENTRY
2208 ? "entry" : "return",
2210 GET_LWP (lp
->ptid
));
2214 if (debug_linux_nat
)
2215 fprintf_unfiltered (gdb_stdlog
,
2216 "LHST: ignoring %s of syscall %d "
2218 lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
2219 ? "entry" : "return",
2221 GET_LWP (lp
->ptid
));
2225 /* If we had been syscall tracing, and hence used PT_SYSCALL
2226 before on this LWP, it could happen that the user removes all
2227 syscall catchpoints before we get to process this event.
2228 There are two noteworthy issues here:
2230 - When stopped at a syscall entry event, resuming with
2231 PT_STEP still resumes executing the syscall and reports a
2234 - Only PT_SYSCALL catches syscall enters. If we last
2235 single-stepped this thread, then this event can't be a
2236 syscall enter. If we last single-stepped this thread, this
2237 has to be a syscall exit.
2239 The points above mean that the next resume, be it PT_STEP or
2240 PT_CONTINUE, can not trigger a syscall trace event. */
2241 if (debug_linux_nat
)
2242 fprintf_unfiltered (gdb_stdlog
,
2243 "LHST: caught syscall event "
2244 "with no syscall catchpoints."
2245 " %d for LWP %ld, ignoring\n",
2247 GET_LWP (lp
->ptid
));
2248 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2251 /* The core isn't interested in this event. For efficiency, avoid
2252 stopping all threads only to have the core resume them all again.
2253 Since we're not stopping threads, if we're still syscall tracing
2254 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
2255 subsequent syscall. Simply resume using the inf-ptrace layer,
2256 which knows when to use PT_SYSCALL or PT_CONTINUE. */
2258 /* Note that gdbarch_get_syscall_number may access registers, hence
2260 registers_changed ();
2261 if (linux_nat_prepare_to_resume
!= NULL
)
2262 linux_nat_prepare_to_resume (lp
);
2263 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
2264 lp
->step
, GDB_SIGNAL_0
);
2268 /* Handle a GNU/Linux extended wait response. If we see a clone
2269 event, we need to add the new LWP to our list (and not report the
2270 trap to higher layers). This function returns non-zero if the
2271 event should be ignored and we should wait again. If STOPPING is
2272 true, the new LWP remains stopped, otherwise it is continued. */
2275 linux_handle_extended_wait (struct lwp_info
*lp
, int status
,
2278 int pid
= GET_LWP (lp
->ptid
);
2279 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
2280 int event
= status
>> 16;
2282 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
2283 || event
== PTRACE_EVENT_CLONE
)
2285 unsigned long new_pid
;
2288 ptrace (PTRACE_GETEVENTMSG
, pid
, 0, &new_pid
);
2290 /* If we haven't already seen the new PID stop, wait for it now. */
2291 if (! pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
2293 /* The new child has a pending SIGSTOP. We can't affect it until it
2294 hits the SIGSTOP, but we're already attached. */
2295 ret
= my_waitpid (new_pid
, &status
,
2296 (event
== PTRACE_EVENT_CLONE
) ? __WCLONE
: 0);
2298 perror_with_name (_("waiting for new child"));
2299 else if (ret
!= new_pid
)
2300 internal_error (__FILE__
, __LINE__
,
2301 _("wait returned unexpected PID %d"), ret
);
2302 else if (!WIFSTOPPED (status
))
2303 internal_error (__FILE__
, __LINE__
,
2304 _("wait returned unexpected status 0x%x"), status
);
2307 ourstatus
->value
.related_pid
= ptid_build (new_pid
, new_pid
, 0);
2309 if (event
== PTRACE_EVENT_FORK
2310 && linux_fork_checkpointing_p (GET_PID (lp
->ptid
)))
2312 /* Handle checkpointing by linux-fork.c here as a special
2313 case. We don't want the follow-fork-mode or 'catch fork'
2314 to interfere with this. */
2316 /* This won't actually modify the breakpoint list, but will
2317 physically remove the breakpoints from the child. */
2318 detach_breakpoints (new_pid
);
2320 /* Retain child fork in ptrace (stopped) state. */
2321 if (!find_fork_pid (new_pid
))
2324 /* Report as spurious, so that infrun doesn't want to follow
2325 this fork. We're actually doing an infcall in
2327 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
2328 linux_enable_event_reporting (pid_to_ptid (new_pid
));
2330 /* Report the stop to the core. */
2334 if (event
== PTRACE_EVENT_FORK
)
2335 ourstatus
->kind
= TARGET_WAITKIND_FORKED
;
2336 else if (event
== PTRACE_EVENT_VFORK
)
2337 ourstatus
->kind
= TARGET_WAITKIND_VFORKED
;
2340 struct lwp_info
*new_lp
;
2342 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2344 if (debug_linux_nat
)
2345 fprintf_unfiltered (gdb_stdlog
,
2346 "LHEW: Got clone event "
2347 "from LWP %d, new child is LWP %ld\n",
2350 new_lp
= add_lwp (BUILD_LWP (new_pid
, GET_PID (lp
->ptid
)));
2352 new_lp
->stopped
= 1;
2354 if (WSTOPSIG (status
) != SIGSTOP
)
2356 /* This can happen if someone starts sending signals to
2357 the new thread before it gets a chance to run, which
2358 have a lower number than SIGSTOP (e.g. SIGUSR1).
2359 This is an unlikely case, and harder to handle for
2360 fork / vfork than for clone, so we do not try - but
2361 we handle it for clone events here. We'll send
2362 the other signal on to the thread below. */
2364 new_lp
->signalled
= 1;
2368 struct thread_info
*tp
;
2370 /* When we stop for an event in some other thread, and
2371 pull the thread list just as this thread has cloned,
2372 we'll have seen the new thread in the thread_db list
2373 before handling the CLONE event (glibc's
2374 pthread_create adds the new thread to the thread list
2375 before clone'ing, and has the kernel fill in the
2376 thread's tid on the clone call with
2377 CLONE_PARENT_SETTID). If that happened, and the core
2378 had requested the new thread to stop, we'll have
2379 killed it with SIGSTOP. But since SIGSTOP is not an
2380 RT signal, it can only be queued once. We need to be
2381 careful to not resume the LWP if we wanted it to
2382 stop. In that case, we'll leave the SIGSTOP pending.
2383 It will later be reported as GDB_SIGNAL_0. */
2384 tp
= find_thread_ptid (new_lp
->ptid
);
2385 if (tp
!= NULL
&& tp
->stop_requested
)
2386 new_lp
->last_resume_kind
= resume_stop
;
2393 /* Add the new thread to GDB's lists as soon as possible
2396 1) the frontend doesn't have to wait for a stop to
2399 2) we tag it with the correct running state. */
2401 /* If the thread_db layer is active, let it know about
2402 this new thread, and add it to GDB's list. */
2403 if (!thread_db_attach_lwp (new_lp
->ptid
))
2405 /* We're not using thread_db. Add it to GDB's
2407 target_post_attach (GET_LWP (new_lp
->ptid
));
2408 add_thread (new_lp
->ptid
);
2413 set_running (new_lp
->ptid
, 1);
2414 set_executing (new_lp
->ptid
, 1);
2415 /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced
2417 new_lp
->last_resume_kind
= resume_continue
;
2423 /* We created NEW_LP so it cannot yet contain STATUS. */
2424 gdb_assert (new_lp
->status
== 0);
2426 /* Save the wait status to report later. */
2427 if (debug_linux_nat
)
2428 fprintf_unfiltered (gdb_stdlog
,
2429 "LHEW: waitpid of new LWP %ld, "
2430 "saving status %s\n",
2431 (long) GET_LWP (new_lp
->ptid
),
2432 status_to_str (status
));
2433 new_lp
->status
= status
;
2436 /* Note the need to use the low target ops to resume, to
2437 handle resuming with PT_SYSCALL if we have syscall
2441 new_lp
->resumed
= 1;
2445 gdb_assert (new_lp
->last_resume_kind
== resume_continue
);
2446 if (debug_linux_nat
)
2447 fprintf_unfiltered (gdb_stdlog
,
2448 "LHEW: resuming new LWP %ld\n",
2449 GET_LWP (new_lp
->ptid
));
2450 if (linux_nat_prepare_to_resume
!= NULL
)
2451 linux_nat_prepare_to_resume (new_lp
);
2452 linux_ops
->to_resume (linux_ops
, pid_to_ptid (new_pid
),
2454 new_lp
->stopped
= 0;
2458 if (debug_linux_nat
)
2459 fprintf_unfiltered (gdb_stdlog
,
2460 "LHEW: resuming parent LWP %d\n", pid
);
2461 if (linux_nat_prepare_to_resume
!= NULL
)
2462 linux_nat_prepare_to_resume (lp
);
2463 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
2472 if (event
== PTRACE_EVENT_EXEC
)
2474 if (debug_linux_nat
)
2475 fprintf_unfiltered (gdb_stdlog
,
2476 "LHEW: Got exec event from LWP %ld\n",
2477 GET_LWP (lp
->ptid
));
2479 ourstatus
->kind
= TARGET_WAITKIND_EXECD
;
2480 ourstatus
->value
.execd_pathname
2481 = xstrdup (linux_child_pid_to_exec_file (pid
));
2486 if (event
== PTRACE_EVENT_VFORK_DONE
)
2488 if (current_inferior ()->waiting_for_vfork_done
)
2490 if (debug_linux_nat
)
2491 fprintf_unfiltered (gdb_stdlog
,
2492 "LHEW: Got expected PTRACE_EVENT_"
2493 "VFORK_DONE from LWP %ld: stopping\n",
2494 GET_LWP (lp
->ptid
));
2496 ourstatus
->kind
= TARGET_WAITKIND_VFORK_DONE
;
2500 if (debug_linux_nat
)
2501 fprintf_unfiltered (gdb_stdlog
,
2502 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2503 "from LWP %ld: resuming\n",
2504 GET_LWP (lp
->ptid
));
2505 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2509 internal_error (__FILE__
, __LINE__
,
2510 _("unknown ptrace event %d"), event
);
2513 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2517 wait_lwp (struct lwp_info
*lp
)
2521 int thread_dead
= 0;
2524 gdb_assert (!lp
->stopped
);
2525 gdb_assert (lp
->status
== 0);
2527 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2528 block_child_signals (&prev_mask
);
2532 /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind
2533 was right and we should just call sigsuspend. */
2535 pid
= my_waitpid (GET_LWP (lp
->ptid
), &status
, WNOHANG
);
2536 if (pid
== -1 && errno
== ECHILD
)
2537 pid
= my_waitpid (GET_LWP (lp
->ptid
), &status
, __WCLONE
| WNOHANG
);
2538 if (pid
== -1 && errno
== ECHILD
)
2540 /* The thread has previously exited. We need to delete it
2541 now because, for some vendor 2.4 kernels with NPTL
2542 support backported, there won't be an exit event unless
2543 it is the main thread. 2.6 kernels will report an exit
2544 event for each thread that exits, as expected. */
2546 if (debug_linux_nat
)
2547 fprintf_unfiltered (gdb_stdlog
, "WL: %s vanished.\n",
2548 target_pid_to_str (lp
->ptid
));
2553 /* Bugs 10970, 12702.
2554 Thread group leader may have exited in which case we'll lock up in
2555 waitpid if there are other threads, even if they are all zombies too.
2556 Basically, we're not supposed to use waitpid this way.
2557 __WCLONE is not applicable for the leader so we can't use that.
2558 LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED
2559 process; it gets ESRCH both for the zombie and for running processes.
2561 As a workaround, check if we're waiting for the thread group leader and
2562 if it's a zombie, and avoid calling waitpid if it is.
2564 This is racy, what if the tgl becomes a zombie right after we check?
2565 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2566 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2568 if (GET_PID (lp
->ptid
) == GET_LWP (lp
->ptid
)
2569 && linux_proc_pid_is_zombie (GET_LWP (lp
->ptid
)))
2572 if (debug_linux_nat
)
2573 fprintf_unfiltered (gdb_stdlog
,
2574 "WL: Thread group leader %s vanished.\n",
2575 target_pid_to_str (lp
->ptid
));
2579 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2580 get invoked despite our caller had them intentionally blocked by
2581 block_child_signals. This is sensitive only to the loop of
2582 linux_nat_wait_1 and there if we get called my_waitpid gets called
2583 again before it gets to sigsuspend so we can safely let the handlers
2584 get executed here. */
2586 sigsuspend (&suspend_mask
);
2589 restore_child_signals_mask (&prev_mask
);
2593 gdb_assert (pid
== GET_LWP (lp
->ptid
));
2595 if (debug_linux_nat
)
2597 fprintf_unfiltered (gdb_stdlog
,
2598 "WL: waitpid %s received %s\n",
2599 target_pid_to_str (lp
->ptid
),
2600 status_to_str (status
));
2603 /* Check if the thread has exited. */
2604 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2607 if (debug_linux_nat
)
2608 fprintf_unfiltered (gdb_stdlog
, "WL: %s exited.\n",
2609 target_pid_to_str (lp
->ptid
));
2619 gdb_assert (WIFSTOPPED (status
));
2621 /* Handle GNU/Linux's syscall SIGTRAPs. */
2622 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2624 /* No longer need the sysgood bit. The ptrace event ends up
2625 recorded in lp->waitstatus if we care for it. We can carry
2626 on handling the event like a regular SIGTRAP from here
2628 status
= W_STOPCODE (SIGTRAP
);
2629 if (linux_handle_syscall_trap (lp
, 1))
2630 return wait_lwp (lp
);
2633 /* Handle GNU/Linux's extended waitstatus for trace events. */
2634 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 != 0)
2636 if (debug_linux_nat
)
2637 fprintf_unfiltered (gdb_stdlog
,
2638 "WL: Handling extended status 0x%06x\n",
2640 if (linux_handle_extended_wait (lp
, status
, 1))
2641 return wait_lwp (lp
);
2647 /* Send a SIGSTOP to LP. */
2650 stop_callback (struct lwp_info
*lp
, void *data
)
2652 if (!lp
->stopped
&& !lp
->signalled
)
2656 if (debug_linux_nat
)
2658 fprintf_unfiltered (gdb_stdlog
,
2659 "SC: kill %s **<SIGSTOP>**\n",
2660 target_pid_to_str (lp
->ptid
));
2663 ret
= kill_lwp (GET_LWP (lp
->ptid
), SIGSTOP
);
2664 if (debug_linux_nat
)
2666 fprintf_unfiltered (gdb_stdlog
,
2667 "SC: lwp kill %d %s\n",
2669 errno
? safe_strerror (errno
) : "ERRNO-OK");
2673 gdb_assert (lp
->status
== 0);
2679 /* Request a stop on LWP. */
2682 linux_stop_lwp (struct lwp_info
*lwp
)
2684 stop_callback (lwp
, NULL
);
2687 /* Return non-zero if LWP PID has a pending SIGINT. */
2690 linux_nat_has_pending_sigint (int pid
)
2692 sigset_t pending
, blocked
, ignored
;
2694 linux_proc_pending_signals (pid
, &pending
, &blocked
, &ignored
);
2696 if (sigismember (&pending
, SIGINT
)
2697 && !sigismember (&ignored
, SIGINT
))
2703 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2706 set_ignore_sigint (struct lwp_info
*lp
, void *data
)
2708 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2709 flag to consume the next one. */
2710 if (lp
->stopped
&& lp
->status
!= 0 && WIFSTOPPED (lp
->status
)
2711 && WSTOPSIG (lp
->status
) == SIGINT
)
2714 lp
->ignore_sigint
= 1;
2719 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2720 This function is called after we know the LWP has stopped; if the LWP
2721 stopped before the expected SIGINT was delivered, then it will never have
2722 arrived. Also, if the signal was delivered to a shared queue and consumed
2723 by a different thread, it will never be delivered to this LWP. */
2726 maybe_clear_ignore_sigint (struct lwp_info
*lp
)
2728 if (!lp
->ignore_sigint
)
2731 if (!linux_nat_has_pending_sigint (GET_LWP (lp
->ptid
)))
2733 if (debug_linux_nat
)
2734 fprintf_unfiltered (gdb_stdlog
,
2735 "MCIS: Clearing bogus flag for %s\n",
2736 target_pid_to_str (lp
->ptid
));
2737 lp
->ignore_sigint
= 0;
2741 /* Fetch the possible triggered data watchpoint info and store it in
2744 On some archs, like x86, that use debug registers to set
2745 watchpoints, it's possible that the way to know which watched
2746 address trapped, is to check the register that is used to select
2747 which address to watch. Problem is, between setting the watchpoint
2748 and reading back which data address trapped, the user may change
2749 the set of watchpoints, and, as a consequence, GDB changes the
2750 debug registers in the inferior. To avoid reading back a stale
2751 stopped-data-address when that happens, we cache in LP the fact
2752 that a watchpoint trapped, and the corresponding data address, as
2753 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2754 registers meanwhile, we have the cached data we can rely on. */
2757 save_sigtrap (struct lwp_info
*lp
)
2759 struct cleanup
*old_chain
;
2761 if (linux_ops
->to_stopped_by_watchpoint
== NULL
)
2763 lp
->stopped_by_watchpoint
= 0;
2767 old_chain
= save_inferior_ptid ();
2768 inferior_ptid
= lp
->ptid
;
2770 lp
->stopped_by_watchpoint
= linux_ops
->to_stopped_by_watchpoint ();
2772 if (lp
->stopped_by_watchpoint
)
2774 if (linux_ops
->to_stopped_data_address
!= NULL
)
2775 lp
->stopped_data_address_p
=
2776 linux_ops
->to_stopped_data_address (¤t_target
,
2777 &lp
->stopped_data_address
);
2779 lp
->stopped_data_address_p
= 0;
2782 do_cleanups (old_chain
);
2785 /* See save_sigtrap. */
2788 linux_nat_stopped_by_watchpoint (void)
2790 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2792 gdb_assert (lp
!= NULL
);
2794 return lp
->stopped_by_watchpoint
;
2798 linux_nat_stopped_data_address (struct target_ops
*ops
, CORE_ADDR
*addr_p
)
2800 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2802 gdb_assert (lp
!= NULL
);
2804 *addr_p
= lp
->stopped_data_address
;
2806 return lp
->stopped_data_address_p
;
2809 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2812 sigtrap_is_event (int status
)
2814 return WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
;
2817 /* SIGTRAP-like events recognizer. */
2819 static int (*linux_nat_status_is_event
) (int status
) = sigtrap_is_event
;
2821 /* Check for SIGTRAP-like events in LP. */
2824 linux_nat_lp_status_is_event (struct lwp_info
*lp
)
2826 /* We check for lp->waitstatus in addition to lp->status, because we can
2827 have pending process exits recorded in lp->status
2828 and W_EXITCODE(0,0) == 0. We should probably have an additional
2829 lp->status_p flag. */
2831 return (lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
2832 && linux_nat_status_is_event (lp
->status
));
2835 /* Set alternative SIGTRAP-like events recognizer. If
2836 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2840 linux_nat_set_status_is_event (struct target_ops
*t
,
2841 int (*status_is_event
) (int status
))
2843 linux_nat_status_is_event
= status_is_event
;
2846 /* Wait until LP is stopped. */
2849 stop_wait_callback (struct lwp_info
*lp
, void *data
)
2851 struct inferior
*inf
= find_inferior_pid (GET_PID (lp
->ptid
));
2853 /* If this is a vfork parent, bail out, it is not going to report
2854 any SIGSTOP until the vfork is done with. */
2855 if (inf
->vfork_child
!= NULL
)
2862 status
= wait_lwp (lp
);
2866 if (lp
->ignore_sigint
&& WIFSTOPPED (status
)
2867 && WSTOPSIG (status
) == SIGINT
)
2869 lp
->ignore_sigint
= 0;
2872 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2873 if (debug_linux_nat
)
2874 fprintf_unfiltered (gdb_stdlog
,
2875 "PTRACE_CONT %s, 0, 0 (%s) "
2876 "(discarding SIGINT)\n",
2877 target_pid_to_str (lp
->ptid
),
2878 errno
? safe_strerror (errno
) : "OK");
2880 return stop_wait_callback (lp
, NULL
);
2883 maybe_clear_ignore_sigint (lp
);
2885 if (WSTOPSIG (status
) != SIGSTOP
)
2887 /* The thread was stopped with a signal other than SIGSTOP. */
2891 if (debug_linux_nat
)
2892 fprintf_unfiltered (gdb_stdlog
,
2893 "SWC: Pending event %s in %s\n",
2894 status_to_str ((int) status
),
2895 target_pid_to_str (lp
->ptid
));
2897 /* Save the sigtrap event. */
2898 lp
->status
= status
;
2899 gdb_assert (!lp
->stopped
);
2900 gdb_assert (lp
->signalled
);
2905 /* We caught the SIGSTOP that we intended to catch, so
2906 there's no SIGSTOP pending. */
2908 if (debug_linux_nat
)
2909 fprintf_unfiltered (gdb_stdlog
,
2910 "SWC: Delayed SIGSTOP caught for %s.\n",
2911 target_pid_to_str (lp
->ptid
));
2915 /* Reset SIGNALLED only after the stop_wait_callback call
2916 above as it does gdb_assert on SIGNALLED. */
2924 /* Return non-zero if LP has a wait status pending. */
2927 status_callback (struct lwp_info
*lp
, void *data
)
2929 /* Only report a pending wait status if we pretend that this has
2930 indeed been resumed. */
2934 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
2936 /* A ptrace event, like PTRACE_FORK|VFORK|EXEC, syscall event,
2937 or a pending process exit. Note that `W_EXITCODE(0,0) ==
2938 0', so a clean process exit can not be stored pending in
2939 lp->status, it is indistinguishable from
2940 no-pending-status. */
2944 if (lp
->status
!= 0)
2950 /* Return non-zero if LP isn't stopped. */
2953 running_callback (struct lwp_info
*lp
, void *data
)
2955 return (!lp
->stopped
2956 || ((lp
->status
!= 0
2957 || lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
2961 /* Count the LWP's that have had events. */
2964 count_events_callback (struct lwp_info
*lp
, void *data
)
2968 gdb_assert (count
!= NULL
);
2970 /* Count only resumed LWPs that have a SIGTRAP event pending. */
2971 if (lp
->resumed
&& linux_nat_lp_status_is_event (lp
))
2977 /* Select the LWP (if any) that is currently being single-stepped. */
2980 select_singlestep_lwp_callback (struct lwp_info
*lp
, void *data
)
2982 if (lp
->last_resume_kind
== resume_step
2989 /* Select the Nth LWP that has had a SIGTRAP event. */
2992 select_event_lwp_callback (struct lwp_info
*lp
, void *data
)
2994 int *selector
= data
;
2996 gdb_assert (selector
!= NULL
);
2998 /* Select only resumed LWPs that have a SIGTRAP event pending. */
2999 if (lp
->resumed
&& linux_nat_lp_status_is_event (lp
))
3000 if ((*selector
)-- == 0)
3007 cancel_breakpoint (struct lwp_info
*lp
)
3009 /* Arrange for a breakpoint to be hit again later. We don't keep
3010 the SIGTRAP status and don't forward the SIGTRAP signal to the
3011 LWP. We will handle the current event, eventually we will resume
3012 this LWP, and this breakpoint will trap again.
3014 If we do not do this, then we run the risk that the user will
3015 delete or disable the breakpoint, but the LWP will have already
3018 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3019 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3022 pc
= regcache_read_pc (regcache
) - gdbarch_decr_pc_after_break (gdbarch
);
3023 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
3025 if (debug_linux_nat
)
3026 fprintf_unfiltered (gdb_stdlog
,
3027 "CB: Push back breakpoint for %s\n",
3028 target_pid_to_str (lp
->ptid
));
3030 /* Back up the PC if necessary. */
3031 if (gdbarch_decr_pc_after_break (gdbarch
))
3032 regcache_write_pc (regcache
, pc
);
3040 cancel_breakpoints_callback (struct lwp_info
*lp
, void *data
)
3042 struct lwp_info
*event_lp
= data
;
3044 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
3048 /* If a LWP other than the LWP that we're reporting an event for has
3049 hit a GDB breakpoint (as opposed to some random trap signal),
3050 then just arrange for it to hit it again later. We don't keep
3051 the SIGTRAP status and don't forward the SIGTRAP signal to the
3052 LWP. We will handle the current event, eventually we will resume
3053 all LWPs, and this one will get its breakpoint trap again.
3055 If we do not do this, then we run the risk that the user will
3056 delete or disable the breakpoint, but the LWP will have already
3059 if (linux_nat_lp_status_is_event (lp
)
3060 && cancel_breakpoint (lp
))
3061 /* Throw away the SIGTRAP. */
3067 /* Select one LWP out of those that have events pending. */
3070 select_event_lwp (ptid_t filter
, struct lwp_info
**orig_lp
, int *status
)
3073 int random_selector
;
3074 struct lwp_info
*event_lp
;
3076 /* Record the wait status for the original LWP. */
3077 (*orig_lp
)->status
= *status
;
3079 /* Give preference to any LWP that is being single-stepped. */
3080 event_lp
= iterate_over_lwps (filter
,
3081 select_singlestep_lwp_callback
, NULL
);
3082 if (event_lp
!= NULL
)
3084 if (debug_linux_nat
)
3085 fprintf_unfiltered (gdb_stdlog
,
3086 "SEL: Select single-step %s\n",
3087 target_pid_to_str (event_lp
->ptid
));
3091 /* No single-stepping LWP. Select one at random, out of those
3092 which have had SIGTRAP events. */
3094 /* First see how many SIGTRAP events we have. */
3095 iterate_over_lwps (filter
, count_events_callback
, &num_events
);
3097 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
3098 random_selector
= (int)
3099 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
3101 if (debug_linux_nat
&& num_events
> 1)
3102 fprintf_unfiltered (gdb_stdlog
,
3103 "SEL: Found %d SIGTRAP events, selecting #%d\n",
3104 num_events
, random_selector
);
3106 event_lp
= iterate_over_lwps (filter
,
3107 select_event_lwp_callback
,
3111 if (event_lp
!= NULL
)
3113 /* Switch the event LWP. */
3114 *orig_lp
= event_lp
;
3115 *status
= event_lp
->status
;
3118 /* Flush the wait status for the event LWP. */
3119 (*orig_lp
)->status
= 0;
3122 /* Return non-zero if LP has been resumed. */
3125 resumed_callback (struct lwp_info
*lp
, void *data
)
3130 /* Stop an active thread, verify it still exists, then resume it. If
3131 the thread ends up with a pending status, then it is not resumed,
3132 and *DATA (really a pointer to int), is set. */
3135 stop_and_resume_callback (struct lwp_info
*lp
, void *data
)
3137 int *new_pending_p
= data
;
3141 ptid_t ptid
= lp
->ptid
;
3143 stop_callback (lp
, NULL
);
3144 stop_wait_callback (lp
, NULL
);
3146 /* Resume if the lwp still exists, and the core wanted it
3148 lp
= find_lwp_pid (ptid
);
3151 if (lp
->last_resume_kind
== resume_stop
3154 /* The core wanted the LWP to stop. Even if it stopped
3155 cleanly (with SIGSTOP), leave the event pending. */
3156 if (debug_linux_nat
)
3157 fprintf_unfiltered (gdb_stdlog
,
3158 "SARC: core wanted LWP %ld stopped "
3159 "(leaving SIGSTOP pending)\n",
3160 GET_LWP (lp
->ptid
));
3161 lp
->status
= W_STOPCODE (SIGSTOP
);
3164 if (lp
->status
== 0)
3166 if (debug_linux_nat
)
3167 fprintf_unfiltered (gdb_stdlog
,
3168 "SARC: re-resuming LWP %ld\n",
3169 GET_LWP (lp
->ptid
));
3170 resume_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
3174 if (debug_linux_nat
)
3175 fprintf_unfiltered (gdb_stdlog
,
3176 "SARC: not re-resuming LWP %ld "
3178 GET_LWP (lp
->ptid
));
3187 /* Check if we should go on and pass this event to common code.
3188 Return the affected lwp if we are, or NULL otherwise. If we stop
3189 all lwps temporarily, we may end up with new pending events in some
3190 other lwp. In that case set *NEW_PENDING_P to true. */
3192 static struct lwp_info
*
3193 linux_nat_filter_event (int lwpid
, int status
, int *new_pending_p
)
3195 struct lwp_info
*lp
;
3199 lp
= find_lwp_pid (pid_to_ptid (lwpid
));
3201 /* Check for stop events reported by a process we didn't already
3202 know about - anything not already in our LWP list.
3204 If we're expecting to receive stopped processes after
3205 fork, vfork, and clone events, then we'll just add the
3206 new one to our list and go back to waiting for the event
3207 to be reported - the stopped process might be returned
3208 from waitpid before or after the event is.
3210 But note the case of a non-leader thread exec'ing after the
3211 leader having exited, and gone from our lists. The non-leader
3212 thread changes its tid to the tgid. */
3214 if (WIFSTOPPED (status
) && lp
== NULL
3215 && (WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 == PTRACE_EVENT_EXEC
))
3217 /* A multi-thread exec after we had seen the leader exiting. */
3218 if (debug_linux_nat
)
3219 fprintf_unfiltered (gdb_stdlog
,
3220 "LLW: Re-adding thread group leader LWP %d.\n",
3223 lp
= add_lwp (BUILD_LWP (lwpid
, lwpid
));
3226 add_thread (lp
->ptid
);
3229 if (WIFSTOPPED (status
) && !lp
)
3231 add_to_pid_list (&stopped_pids
, lwpid
, status
);
3235 /* Make sure we don't report an event for the exit of an LWP not in
3236 our list, i.e. not part of the current process. This can happen
3237 if we detach from a program we originally forked and then it
3239 if (!WIFSTOPPED (status
) && !lp
)
3242 /* Handle GNU/Linux's syscall SIGTRAPs. */
3243 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
3245 /* No longer need the sysgood bit. The ptrace event ends up
3246 recorded in lp->waitstatus if we care for it. We can carry
3247 on handling the event like a regular SIGTRAP from here
3249 status
= W_STOPCODE (SIGTRAP
);
3250 if (linux_handle_syscall_trap (lp
, 0))
3254 /* Handle GNU/Linux's extended waitstatus for trace events. */
3255 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 != 0)
3257 if (debug_linux_nat
)
3258 fprintf_unfiltered (gdb_stdlog
,
3259 "LLW: Handling extended status 0x%06x\n",
3261 if (linux_handle_extended_wait (lp
, status
, 0))
3265 if (linux_nat_status_is_event (status
))
3268 /* Check if the thread has exited. */
3269 if ((WIFEXITED (status
) || WIFSIGNALED (status
))
3270 && num_lwps (GET_PID (lp
->ptid
)) > 1)
3272 /* If this is the main thread, we must stop all threads and verify
3273 if they are still alive. This is because in the nptl thread model
3274 on Linux 2.4, there is no signal issued for exiting LWPs
3275 other than the main thread. We only get the main thread exit
3276 signal once all child threads have already exited. If we
3277 stop all the threads and use the stop_wait_callback to check
3278 if they have exited we can determine whether this signal
3279 should be ignored or whether it means the end of the debugged
3280 application, regardless of which threading model is being
3282 if (GET_PID (lp
->ptid
) == GET_LWP (lp
->ptid
))
3285 iterate_over_lwps (pid_to_ptid (GET_PID (lp
->ptid
)),
3286 stop_and_resume_callback
, new_pending_p
);
3289 if (debug_linux_nat
)
3290 fprintf_unfiltered (gdb_stdlog
,
3291 "LLW: %s exited.\n",
3292 target_pid_to_str (lp
->ptid
));
3294 if (num_lwps (GET_PID (lp
->ptid
)) > 1)
3296 /* If there is at least one more LWP, then the exit signal
3297 was not the end of the debugged application and should be
3304 /* Check if the current LWP has previously exited. In the nptl
3305 thread model, LWPs other than the main thread do not issue
3306 signals when they exit so we must check whenever the thread has
3307 stopped. A similar check is made in stop_wait_callback(). */
3308 if (num_lwps (GET_PID (lp
->ptid
)) > 1 && !linux_thread_alive (lp
->ptid
))
3310 ptid_t ptid
= pid_to_ptid (GET_PID (lp
->ptid
));
3312 if (debug_linux_nat
)
3313 fprintf_unfiltered (gdb_stdlog
,
3314 "LLW: %s exited.\n",
3315 target_pid_to_str (lp
->ptid
));
3319 /* Make sure there is at least one thread running. */
3320 gdb_assert (iterate_over_lwps (ptid
, running_callback
, NULL
));
3322 /* Discard the event. */
3326 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3327 an attempt to stop an LWP. */
3329 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGSTOP
)
3331 if (debug_linux_nat
)
3332 fprintf_unfiltered (gdb_stdlog
,
3333 "LLW: Delayed SIGSTOP caught for %s.\n",
3334 target_pid_to_str (lp
->ptid
));
3338 if (lp
->last_resume_kind
!= resume_stop
)
3340 /* This is a delayed SIGSTOP. */
3342 registers_changed ();
3344 if (linux_nat_prepare_to_resume
!= NULL
)
3345 linux_nat_prepare_to_resume (lp
);
3346 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
3347 lp
->step
, GDB_SIGNAL_0
);
3348 if (debug_linux_nat
)
3349 fprintf_unfiltered (gdb_stdlog
,
3350 "LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
3352 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3353 target_pid_to_str (lp
->ptid
));
3356 gdb_assert (lp
->resumed
);
3358 /* Discard the event. */
3363 /* Make sure we don't report a SIGINT that we have already displayed
3364 for another thread. */
3365 if (lp
->ignore_sigint
3366 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGINT
)
3368 if (debug_linux_nat
)
3369 fprintf_unfiltered (gdb_stdlog
,
3370 "LLW: Delayed SIGINT caught for %s.\n",
3371 target_pid_to_str (lp
->ptid
));
3373 /* This is a delayed SIGINT. */
3374 lp
->ignore_sigint
= 0;
3376 registers_changed ();
3377 if (linux_nat_prepare_to_resume
!= NULL
)
3378 linux_nat_prepare_to_resume (lp
);
3379 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
3380 lp
->step
, GDB_SIGNAL_0
);
3381 if (debug_linux_nat
)
3382 fprintf_unfiltered (gdb_stdlog
,
3383 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3385 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3386 target_pid_to_str (lp
->ptid
));
3389 gdb_assert (lp
->resumed
);
3391 /* Discard the event. */
3395 /* An interesting event. */
3397 lp
->status
= status
;
3401 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3402 their exits until all other threads in the group have exited. */
3405 check_zombie_leaders (void)
3407 struct inferior
*inf
;
3411 struct lwp_info
*leader_lp
;
3416 leader_lp
= find_lwp_pid (pid_to_ptid (inf
->pid
));
3417 if (leader_lp
!= NULL
3418 /* Check if there are other threads in the group, as we may
3419 have raced with the inferior simply exiting. */
3420 && num_lwps (inf
->pid
) > 1
3421 && linux_proc_pid_is_zombie (inf
->pid
))
3423 if (debug_linux_nat
)
3424 fprintf_unfiltered (gdb_stdlog
,
3425 "CZL: Thread group leader %d zombie "
3426 "(it exited, or another thread execd).\n",
3429 /* A leader zombie can mean one of two things:
3431 - It exited, and there's an exit status pending
3432 available, or only the leader exited (not the whole
3433 program). In the latter case, we can't waitpid the
3434 leader's exit status until all other threads are gone.
3436 - There are 3 or more threads in the group, and a thread
3437 other than the leader exec'd. On an exec, the Linux
3438 kernel destroys all other threads (except the execing
3439 one) in the thread group, and resets the execing thread's
3440 tid to the tgid. No exit notification is sent for the
3441 execing thread -- from the ptracer's perspective, it
3442 appears as though the execing thread just vanishes.
3443 Until we reap all other threads except the leader and the
3444 execing thread, the leader will be zombie, and the
3445 execing thread will be in `D (disc sleep)'. As soon as
3446 all other threads are reaped, the execing thread changes
3447 it's tid to the tgid, and the previous (zombie) leader
3448 vanishes, giving place to the "new" leader. We could try
3449 distinguishing the exit and exec cases, by waiting once
3450 more, and seeing if something comes out, but it doesn't
3451 sound useful. The previous leader _does_ go away, and
3452 we'll re-add the new one once we see the exec event
3453 (which is just the same as what would happen if the
3454 previous leader did exit voluntarily before some other
3457 if (debug_linux_nat
)
3458 fprintf_unfiltered (gdb_stdlog
,
3459 "CZL: Thread group leader %d vanished.\n",
3461 exit_lwp (leader_lp
);
3467 linux_nat_wait_1 (struct target_ops
*ops
,
3468 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3471 static sigset_t prev_mask
;
3472 enum resume_kind last_resume_kind
;
3473 struct lwp_info
*lp
;
3476 if (debug_linux_nat
)
3477 fprintf_unfiltered (gdb_stdlog
, "LLW: enter\n");
3479 /* The first time we get here after starting a new inferior, we may
3480 not have added it to the LWP list yet - this is the earliest
3481 moment at which we know its PID. */
3482 if (ptid_is_pid (inferior_ptid
))
3484 /* Upgrade the main thread's ptid. */
3485 thread_change_ptid (inferior_ptid
,
3486 BUILD_LWP (GET_PID (inferior_ptid
),
3487 GET_PID (inferior_ptid
)));
3489 lp
= add_lwp (inferior_ptid
);
3493 /* Make sure SIGCHLD is blocked. */
3494 block_child_signals (&prev_mask
);
3500 /* First check if there is a LWP with a wait status pending. */
3501 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3503 /* Any LWP in the PTID group that's been resumed will do. */
3504 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3507 if (debug_linux_nat
&& lp
->status
)
3508 fprintf_unfiltered (gdb_stdlog
,
3509 "LLW: Using pending wait status %s for %s.\n",
3510 status_to_str (lp
->status
),
3511 target_pid_to_str (lp
->ptid
));
3514 else if (is_lwp (ptid
))
3516 if (debug_linux_nat
)
3517 fprintf_unfiltered (gdb_stdlog
,
3518 "LLW: Waiting for specific LWP %s.\n",
3519 target_pid_to_str (ptid
));
3521 /* We have a specific LWP to check. */
3522 lp
= find_lwp_pid (ptid
);
3525 if (debug_linux_nat
&& lp
->status
)
3526 fprintf_unfiltered (gdb_stdlog
,
3527 "LLW: Using pending wait status %s for %s.\n",
3528 status_to_str (lp
->status
),
3529 target_pid_to_str (lp
->ptid
));
3531 /* We check for lp->waitstatus in addition to lp->status,
3532 because we can have pending process exits recorded in
3533 lp->status and W_EXITCODE(0,0) == 0. We should probably have
3534 an additional lp->status_p flag. */
3535 if (lp
->status
== 0 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
3539 if (!target_can_async_p ())
3541 /* Causes SIGINT to be passed on to the attached process. */
3545 /* But if we don't find a pending event, we'll have to wait. */
3551 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3554 - If the thread group leader exits while other threads in the
3555 thread group still exist, waitpid(TGID, ...) hangs. That
3556 waitpid won't return an exit status until the other threads
3557 in the group are reapped.
3559 - When a non-leader thread execs, that thread just vanishes
3560 without reporting an exit (so we'd hang if we waited for it
3561 explicitly in that case). The exec event is reported to
3565 lwpid
= my_waitpid (-1, &status
, __WCLONE
| WNOHANG
);
3566 if (lwpid
== 0 || (lwpid
== -1 && errno
== ECHILD
))
3567 lwpid
= my_waitpid (-1, &status
, WNOHANG
);
3569 if (debug_linux_nat
)
3570 fprintf_unfiltered (gdb_stdlog
,
3571 "LNW: waitpid(-1, ...) returned %d, %s\n",
3572 lwpid
, errno
? safe_strerror (errno
) : "ERRNO-OK");
3576 /* If this is true, then we paused LWPs momentarily, and may
3577 now have pending events to handle. */
3580 if (debug_linux_nat
)
3582 fprintf_unfiltered (gdb_stdlog
,
3583 "LLW: waitpid %ld received %s\n",
3584 (long) lwpid
, status_to_str (status
));
3587 lp
= linux_nat_filter_event (lwpid
, status
, &new_pending
);
3589 /* STATUS is now no longer valid, use LP->STATUS instead. */
3592 if (lp
&& !ptid_match (lp
->ptid
, ptid
))
3594 gdb_assert (lp
->resumed
);
3596 if (debug_linux_nat
)
3598 "LWP %ld got an event %06x, leaving pending.\n",
3599 ptid_get_lwp (lp
->ptid
), lp
->status
);
3601 if (WIFSTOPPED (lp
->status
))
3603 if (WSTOPSIG (lp
->status
) != SIGSTOP
)
3605 /* Cancel breakpoint hits. The breakpoint may
3606 be removed before we fetch events from this
3607 process to report to the core. It is best
3608 not to assume the moribund breakpoints
3609 heuristic always handles these cases --- it
3610 could be too many events go through to the
3611 core before this one is handled. All-stop
3612 always cancels breakpoint hits in all
3615 && linux_nat_lp_status_is_event (lp
)
3616 && cancel_breakpoint (lp
))
3618 /* Throw away the SIGTRAP. */
3621 if (debug_linux_nat
)
3623 "LLW: LWP %ld hit a breakpoint while"
3624 " waiting for another process;"
3626 ptid_get_lwp (lp
->ptid
));
3636 else if (WIFEXITED (lp
->status
) || WIFSIGNALED (lp
->status
))
3638 if (debug_linux_nat
)
3640 "Process %ld exited while stopping LWPs\n",
3641 ptid_get_lwp (lp
->ptid
));
3643 /* This was the last lwp in the process. Since
3644 events are serialized to GDB core, and we can't
3645 report this one right now, but GDB core and the
3646 other target layers will want to be notified
3647 about the exit code/signal, leave the status
3648 pending for the next time we're able to report
3651 /* Prevent trying to stop this thread again. We'll
3652 never try to resume it because it has a pending
3656 /* Dead LWP's aren't expected to reported a pending
3660 /* Store the pending event in the waitstatus as
3661 well, because W_EXITCODE(0,0) == 0. */
3662 store_waitstatus (&lp
->waitstatus
, lp
->status
);
3671 /* Some LWP now has a pending event. Go all the way
3672 back to check it. */
3678 /* We got an event to report to the core. */
3682 /* Retry until nothing comes out of waitpid. A single
3683 SIGCHLD can indicate more than one child stopped. */
3687 /* Check for zombie thread group leaders. Those can't be reaped
3688 until all other threads in the thread group are. */
3689 check_zombie_leaders ();
3691 /* If there are no resumed children left, bail. We'd be stuck
3692 forever in the sigsuspend call below otherwise. */
3693 if (iterate_over_lwps (ptid
, resumed_callback
, NULL
) == NULL
)
3695 if (debug_linux_nat
)
3696 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (no resumed LWP)\n");
3698 ourstatus
->kind
= TARGET_WAITKIND_NO_RESUMED
;
3700 if (!target_can_async_p ())
3701 clear_sigint_trap ();
3703 restore_child_signals_mask (&prev_mask
);
3704 return minus_one_ptid
;
3707 /* No interesting event to report to the core. */
3709 if (target_options
& TARGET_WNOHANG
)
3711 if (debug_linux_nat
)
3712 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (ignore)\n");
3714 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3715 restore_child_signals_mask (&prev_mask
);
3716 return minus_one_ptid
;
3719 /* We shouldn't end up here unless we want to try again. */
3720 gdb_assert (lp
== NULL
);
3722 /* Block until we get an event reported with SIGCHLD. */
3723 sigsuspend (&suspend_mask
);
3726 if (!target_can_async_p ())
3727 clear_sigint_trap ();
3731 status
= lp
->status
;
3734 /* Don't report signals that GDB isn't interested in, such as
3735 signals that are neither printed nor stopped upon. Stopping all
3736 threads can be a bit time-consuming so if we want decent
3737 performance with heavily multi-threaded programs, especially when
3738 they're using a high frequency timer, we'd better avoid it if we
3741 if (WIFSTOPPED (status
))
3743 enum gdb_signal signo
= gdb_signal_from_host (WSTOPSIG (status
));
3745 /* When using hardware single-step, we need to report every signal.
3746 Otherwise, signals in pass_mask may be short-circuited. */
3748 && WSTOPSIG (status
) && sigismember (&pass_mask
, WSTOPSIG (status
)))
3750 /* FIMXE: kettenis/2001-06-06: Should we resume all threads
3751 here? It is not clear we should. GDB may not expect
3752 other threads to run. On the other hand, not resuming
3753 newly attached threads may cause an unwanted delay in
3754 getting them running. */
3755 registers_changed ();
3756 if (linux_nat_prepare_to_resume
!= NULL
)
3757 linux_nat_prepare_to_resume (lp
);
3758 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
3760 if (debug_linux_nat
)
3761 fprintf_unfiltered (gdb_stdlog
,
3762 "LLW: %s %s, %s (preempt 'handle')\n",
3764 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3765 target_pid_to_str (lp
->ptid
),
3766 (signo
!= GDB_SIGNAL_0
3767 ? strsignal (gdb_signal_to_host (signo
))
3775 /* Only do the below in all-stop, as we currently use SIGINT
3776 to implement target_stop (see linux_nat_stop) in
3778 if (signo
== GDB_SIGNAL_INT
&& signal_pass_state (signo
) == 0)
3780 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3781 forwarded to the entire process group, that is, all LWPs
3782 will receive it - unless they're using CLONE_THREAD to
3783 share signals. Since we only want to report it once, we
3784 mark it as ignored for all LWPs except this one. */
3785 iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid
)),
3786 set_ignore_sigint
, NULL
);
3787 lp
->ignore_sigint
= 0;
3790 maybe_clear_ignore_sigint (lp
);
3794 /* This LWP is stopped now. */
3797 if (debug_linux_nat
)
3798 fprintf_unfiltered (gdb_stdlog
, "LLW: Candidate event %s in %s.\n",
3799 status_to_str (status
), target_pid_to_str (lp
->ptid
));
3803 /* Now stop all other LWP's ... */
3804 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
3806 /* ... and wait until all of them have reported back that
3807 they're no longer running. */
3808 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
3810 /* If we're not waiting for a specific LWP, choose an event LWP
3811 from among those that have had events. Giving equal priority
3812 to all LWPs that have had events helps prevent
3814 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3815 select_event_lwp (ptid
, &lp
, &status
);
3817 /* Now that we've selected our final event LWP, cancel any
3818 breakpoints in other LWPs that have hit a GDB breakpoint.
3819 See the comment in cancel_breakpoints_callback to find out
3821 iterate_over_lwps (minus_one_ptid
, cancel_breakpoints_callback
, lp
);
3823 /* We'll need this to determine whether to report a SIGSTOP as
3824 TARGET_WAITKIND_0. Need to take a copy because
3825 resume_clear_callback clears it. */
3826 last_resume_kind
= lp
->last_resume_kind
;
3828 /* In all-stop, from the core's perspective, all LWPs are now
3829 stopped until a new resume action is sent over. */
3830 iterate_over_lwps (minus_one_ptid
, resume_clear_callback
, NULL
);
3835 last_resume_kind
= lp
->last_resume_kind
;
3836 resume_clear_callback (lp
, NULL
);
3839 if (linux_nat_status_is_event (status
))
3841 if (debug_linux_nat
)
3842 fprintf_unfiltered (gdb_stdlog
,
3843 "LLW: trap ptid is %s.\n",
3844 target_pid_to_str (lp
->ptid
));
3847 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3849 *ourstatus
= lp
->waitstatus
;
3850 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3853 store_waitstatus (ourstatus
, status
);
3855 if (debug_linux_nat
)
3856 fprintf_unfiltered (gdb_stdlog
, "LLW: exit\n");
3858 restore_child_signals_mask (&prev_mask
);
3860 if (last_resume_kind
== resume_stop
3861 && ourstatus
->kind
== TARGET_WAITKIND_STOPPED
3862 && WSTOPSIG (status
) == SIGSTOP
)
3864 /* A thread that has been requested to stop by GDB with
3865 target_stop, and it stopped cleanly, so report as SIG0. The
3866 use of SIGSTOP is an implementation detail. */
3867 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3870 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
3871 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
3874 lp
->core
= linux_common_core_of_thread (lp
->ptid
);
3879 /* Resume LWPs that are currently stopped without any pending status
3880 to report, but are resumed from the core's perspective. */
3883 resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
)
3885 ptid_t
*wait_ptid_p
= data
;
3890 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
3892 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3893 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3894 CORE_ADDR pc
= regcache_read_pc (regcache
);
3896 gdb_assert (is_executing (lp
->ptid
));
3898 /* Don't bother if there's a breakpoint at PC that we'd hit
3899 immediately, and we're not waiting for this LWP. */
3900 if (!ptid_match (lp
->ptid
, *wait_ptid_p
))
3902 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
3906 if (debug_linux_nat
)
3907 fprintf_unfiltered (gdb_stdlog
,
3908 "RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n",
3909 target_pid_to_str (lp
->ptid
),
3910 paddress (gdbarch
, pc
),
3913 registers_changed ();
3914 if (linux_nat_prepare_to_resume
!= NULL
)
3915 linux_nat_prepare_to_resume (lp
);
3916 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
3917 lp
->step
, GDB_SIGNAL_0
);
3919 lp
->stopped_by_watchpoint
= 0;
3926 linux_nat_wait (struct target_ops
*ops
,
3927 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3932 if (debug_linux_nat
)
3933 fprintf_unfiltered (gdb_stdlog
,
3934 "linux_nat_wait: [%s]\n", target_pid_to_str (ptid
));
3936 /* Flush the async file first. */
3937 if (target_can_async_p ())
3938 async_file_flush ();
3940 /* Resume LWPs that are currently stopped without any pending status
3941 to report, but are resumed from the core's perspective. LWPs get
3942 in this state if we find them stopping at a time we're not
3943 interested in reporting the event (target_wait on a
3944 specific_process, for example, see linux_nat_wait_1), and
3945 meanwhile the event became uninteresting. Don't bother resuming
3946 LWPs we're not going to wait for if they'd stop immediately. */
3948 iterate_over_lwps (minus_one_ptid
, resume_stopped_resumed_lwps
, &ptid
);
3950 event_ptid
= linux_nat_wait_1 (ops
, ptid
, ourstatus
, target_options
);
3952 /* If we requested any event, and something came out, assume there
3953 may be more. If we requested a specific lwp or process, also
3954 assume there may be more. */
3955 if (target_can_async_p ()
3956 && ((ourstatus
->kind
!= TARGET_WAITKIND_IGNORE
3957 && ourstatus
->kind
!= TARGET_WAITKIND_NO_RESUMED
)
3958 || !ptid_equal (ptid
, minus_one_ptid
)))
3961 /* Get ready for the next event. */
3962 if (target_can_async_p ())
3963 target_async (inferior_event_handler
, 0);
3969 kill_callback (struct lwp_info
*lp
, void *data
)
3971 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3974 kill (GET_LWP (lp
->ptid
), SIGKILL
);
3975 if (debug_linux_nat
)
3976 fprintf_unfiltered (gdb_stdlog
,
3977 "KC: kill (SIGKILL) %s, 0, 0 (%s)\n",
3978 target_pid_to_str (lp
->ptid
),
3979 errno
? safe_strerror (errno
) : "OK");
3981 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3984 ptrace (PTRACE_KILL
, GET_LWP (lp
->ptid
), 0, 0);
3985 if (debug_linux_nat
)
3986 fprintf_unfiltered (gdb_stdlog
,
3987 "KC: PTRACE_KILL %s, 0, 0 (%s)\n",
3988 target_pid_to_str (lp
->ptid
),
3989 errno
? safe_strerror (errno
) : "OK");
3995 kill_wait_callback (struct lwp_info
*lp
, void *data
)
3999 /* We must make sure that there are no pending events (delayed
4000 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
4001 program doesn't interfere with any following debugging session. */
4003 /* For cloned processes we must check both with __WCLONE and
4004 without, since the exit status of a cloned process isn't reported
4010 pid
= my_waitpid (GET_LWP (lp
->ptid
), NULL
, __WCLONE
);
4011 if (pid
!= (pid_t
) -1)
4013 if (debug_linux_nat
)
4014 fprintf_unfiltered (gdb_stdlog
,
4015 "KWC: wait %s received unknown.\n",
4016 target_pid_to_str (lp
->ptid
));
4017 /* The Linux kernel sometimes fails to kill a thread
4018 completely after PTRACE_KILL; that goes from the stop
4019 point in do_fork out to the one in
4020 get_signal_to_deliever and waits again. So kill it
4022 kill_callback (lp
, NULL
);
4025 while (pid
== GET_LWP (lp
->ptid
));
4027 gdb_assert (pid
== -1 && errno
== ECHILD
);
4032 pid
= my_waitpid (GET_LWP (lp
->ptid
), NULL
, 0);
4033 if (pid
!= (pid_t
) -1)
4035 if (debug_linux_nat
)
4036 fprintf_unfiltered (gdb_stdlog
,
4037 "KWC: wait %s received unk.\n",
4038 target_pid_to_str (lp
->ptid
));
4039 /* See the call to kill_callback above. */
4040 kill_callback (lp
, NULL
);
4043 while (pid
== GET_LWP (lp
->ptid
));
4045 gdb_assert (pid
== -1 && errno
== ECHILD
);
4050 linux_nat_kill (struct target_ops
*ops
)
4052 struct target_waitstatus last
;
4056 /* If we're stopped while forking and we haven't followed yet,
4057 kill the other task. We need to do this first because the
4058 parent will be sleeping if this is a vfork. */
4060 get_last_target_status (&last_ptid
, &last
);
4062 if (last
.kind
== TARGET_WAITKIND_FORKED
4063 || last
.kind
== TARGET_WAITKIND_VFORKED
)
4065 ptrace (PT_KILL
, PIDGET (last
.value
.related_pid
), 0, 0);
4069 if (forks_exist_p ())
4070 linux_fork_killall ();
4073 ptid_t ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
4075 /* Stop all threads before killing them, since ptrace requires
4076 that the thread is stopped to sucessfully PTRACE_KILL. */
4077 iterate_over_lwps (ptid
, stop_callback
, NULL
);
4078 /* ... and wait until all of them have reported back that
4079 they're no longer running. */
4080 iterate_over_lwps (ptid
, stop_wait_callback
, NULL
);
4082 /* Kill all LWP's ... */
4083 iterate_over_lwps (ptid
, kill_callback
, NULL
);
4085 /* ... and wait until we've flushed all events. */
4086 iterate_over_lwps (ptid
, kill_wait_callback
, NULL
);
4089 target_mourn_inferior ();
4093 linux_nat_mourn_inferior (struct target_ops
*ops
)
4095 purge_lwp_list (ptid_get_pid (inferior_ptid
));
4097 if (! forks_exist_p ())
4098 /* Normal case, no other forks available. */
4099 linux_ops
->to_mourn_inferior (ops
);
4101 /* Multi-fork case. The current inferior_ptid has exited, but
4102 there are other viable forks to debug. Delete the exiting
4103 one and context-switch to the first available. */
4104 linux_fork_mourn_inferior ();
4107 /* Convert a native/host siginfo object, into/from the siginfo in the
4108 layout of the inferiors' architecture. */
4111 siginfo_fixup (siginfo_t
*siginfo
, gdb_byte
*inf_siginfo
, int direction
)
4115 if (linux_nat_siginfo_fixup
!= NULL
)
4116 done
= linux_nat_siginfo_fixup (siginfo
, inf_siginfo
, direction
);
4118 /* If there was no callback, or the callback didn't do anything,
4119 then just do a straight memcpy. */
4123 memcpy (siginfo
, inf_siginfo
, sizeof (siginfo_t
));
4125 memcpy (inf_siginfo
, siginfo
, sizeof (siginfo_t
));
4130 linux_xfer_siginfo (struct target_ops
*ops
, enum target_object object
,
4131 const char *annex
, gdb_byte
*readbuf
,
4132 const gdb_byte
*writebuf
, ULONGEST offset
, LONGEST len
)
4136 gdb_byte inf_siginfo
[sizeof (siginfo_t
)];
4138 gdb_assert (object
== TARGET_OBJECT_SIGNAL_INFO
);
4139 gdb_assert (readbuf
|| writebuf
);
4141 pid
= GET_LWP (inferior_ptid
);
4143 pid
= GET_PID (inferior_ptid
);
4145 if (offset
> sizeof (siginfo
))
4149 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
4153 /* When GDB is built as a 64-bit application, ptrace writes into
4154 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
4155 inferior with a 64-bit GDB should look the same as debugging it
4156 with a 32-bit GDB, we need to convert it. GDB core always sees
4157 the converted layout, so any read/write will have to be done
4159 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
4161 if (offset
+ len
> sizeof (siginfo
))
4162 len
= sizeof (siginfo
) - offset
;
4164 if (readbuf
!= NULL
)
4165 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
4168 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
4170 /* Convert back to ptrace layout before flushing it out. */
4171 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
4174 ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
4183 linux_nat_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4184 const char *annex
, gdb_byte
*readbuf
,
4185 const gdb_byte
*writebuf
,
4186 ULONGEST offset
, LONGEST len
)
4188 struct cleanup
*old_chain
;
4191 if (object
== TARGET_OBJECT_SIGNAL_INFO
)
4192 return linux_xfer_siginfo (ops
, object
, annex
, readbuf
, writebuf
,
4195 /* The target is connected but no live inferior is selected. Pass
4196 this request down to a lower stratum (e.g., the executable
4198 if (object
== TARGET_OBJECT_MEMORY
&& ptid_equal (inferior_ptid
, null_ptid
))
4201 old_chain
= save_inferior_ptid ();
4203 if (is_lwp (inferior_ptid
))
4204 inferior_ptid
= pid_to_ptid (GET_LWP (inferior_ptid
));
4206 xfer
= linux_ops
->to_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4209 do_cleanups (old_chain
);
4214 linux_thread_alive (ptid_t ptid
)
4218 gdb_assert (is_lwp (ptid
));
4220 /* Send signal 0 instead of anything ptrace, because ptracing a
4221 running thread errors out claiming that the thread doesn't
4223 err
= kill_lwp (GET_LWP (ptid
), 0);
4225 if (debug_linux_nat
)
4226 fprintf_unfiltered (gdb_stdlog
,
4227 "LLTA: KILL(SIG0) %s (%s)\n",
4228 target_pid_to_str (ptid
),
4229 err
? safe_strerror (tmp_errno
) : "OK");
4238 linux_nat_thread_alive (struct target_ops
*ops
, ptid_t ptid
)
4240 return linux_thread_alive (ptid
);
4244 linux_nat_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
4246 static char buf
[64];
4249 && (GET_PID (ptid
) != GET_LWP (ptid
)
4250 || num_lwps (GET_PID (ptid
)) > 1))
4252 snprintf (buf
, sizeof (buf
), "LWP %ld", GET_LWP (ptid
));
4256 return normal_pid_to_str (ptid
);
4260 linux_nat_thread_name (struct thread_info
*thr
)
4262 int pid
= ptid_get_pid (thr
->ptid
);
4263 long lwp
= ptid_get_lwp (thr
->ptid
);
4264 #define FORMAT "/proc/%d/task/%ld/comm"
4265 char buf
[sizeof (FORMAT
) + 30];
4267 char *result
= NULL
;
4269 snprintf (buf
, sizeof (buf
), FORMAT
, pid
, lwp
);
4270 comm_file
= fopen (buf
, "r");
4273 /* Not exported by the kernel, so we define it here. */
4275 static char line
[COMM_LEN
+ 1];
4277 if (fgets (line
, sizeof (line
), comm_file
))
4279 char *nl
= strchr (line
, '\n');
4296 /* Accepts an integer PID; Returns a string representing a file that
4297 can be opened to get the symbols for the child process. */
4300 linux_child_pid_to_exec_file (int pid
)
4302 char *name1
, *name2
;
4304 name1
= xmalloc (MAXPATHLEN
);
4305 name2
= xmalloc (MAXPATHLEN
);
4306 make_cleanup (xfree
, name1
);
4307 make_cleanup (xfree
, name2
);
4308 memset (name2
, 0, MAXPATHLEN
);
4310 sprintf (name1
, "/proc/%d/exe", pid
);
4311 if (readlink (name1
, name2
, MAXPATHLEN
) > 0)
4317 /* Records the thread's register state for the corefile note
4321 linux_nat_collect_thread_registers (const struct regcache
*regcache
,
4322 ptid_t ptid
, bfd
*obfd
,
4323 char *note_data
, int *note_size
,
4324 enum gdb_signal stop_signal
)
4326 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
4327 const struct regset
*regset
;
4329 gdb_gregset_t gregs
;
4330 gdb_fpregset_t fpregs
;
4332 core_regset_p
= gdbarch_regset_from_core_section_p (gdbarch
);
4335 && (regset
= gdbarch_regset_from_core_section (gdbarch
, ".reg",
4337 != NULL
&& regset
->collect_regset
!= NULL
)
4338 regset
->collect_regset (regset
, regcache
, -1, &gregs
, sizeof (gregs
));
4340 fill_gregset (regcache
, &gregs
, -1);
4342 note_data
= (char *) elfcore_write_prstatus
4343 (obfd
, note_data
, note_size
, ptid_get_lwp (ptid
),
4344 gdb_signal_to_host (stop_signal
), &gregs
);
4347 && (regset
= gdbarch_regset_from_core_section (gdbarch
, ".reg2",
4349 != NULL
&& regset
->collect_regset
!= NULL
)
4350 regset
->collect_regset (regset
, regcache
, -1, &fpregs
, sizeof (fpregs
));
4352 fill_fpregset (regcache
, &fpregs
, -1);
4354 note_data
= (char *) elfcore_write_prfpreg (obfd
, note_data
, note_size
,
4355 &fpregs
, sizeof (fpregs
));
4360 /* Fills the "to_make_corefile_note" target vector. Builds the note
4361 section for a corefile, and returns it in a malloc buffer. */
4364 linux_nat_make_corefile_notes (bfd
*obfd
, int *note_size
)
4366 /* FIXME: uweigand/2011-10-06: Once all GNU/Linux architectures have been
4367 converted to gdbarch_core_regset_sections, this function can go away. */
4368 return linux_make_corefile_notes (target_gdbarch
, obfd
, note_size
,
4369 linux_nat_collect_thread_registers
);
4372 /* Implement the to_xfer_partial interface for memory reads using the /proc
4373 filesystem. Because we can use a single read() call for /proc, this
4374 can be much more efficient than banging away at PTRACE_PEEKTEXT,
4375 but it doesn't support writes. */
4378 linux_proc_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4379 const char *annex
, gdb_byte
*readbuf
,
4380 const gdb_byte
*writebuf
,
4381 ULONGEST offset
, LONGEST len
)
4387 if (object
!= TARGET_OBJECT_MEMORY
|| !readbuf
)
4390 /* Don't bother for one word. */
4391 if (len
< 3 * sizeof (long))
4394 /* We could keep this file open and cache it - possibly one per
4395 thread. That requires some juggling, but is even faster. */
4396 sprintf (filename
, "/proc/%d/mem", PIDGET (inferior_ptid
));
4397 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
4401 /* If pread64 is available, use it. It's faster if the kernel
4402 supports it (only one syscall), and it's 64-bit safe even on
4403 32-bit platforms (for instance, SPARC debugging a SPARC64
4406 if (pread64 (fd
, readbuf
, len
, offset
) != len
)
4408 if (lseek (fd
, offset
, SEEK_SET
) == -1 || read (fd
, readbuf
, len
) != len
)
4419 /* Enumerate spufs IDs for process PID. */
4421 spu_enumerate_spu_ids (int pid
, gdb_byte
*buf
, ULONGEST offset
, LONGEST len
)
4423 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch
);
4425 LONGEST written
= 0;
4428 struct dirent
*entry
;
4430 xsnprintf (path
, sizeof path
, "/proc/%d/fd", pid
);
4431 dir
= opendir (path
);
4436 while ((entry
= readdir (dir
)) != NULL
)
4442 fd
= atoi (entry
->d_name
);
4446 xsnprintf (path
, sizeof path
, "/proc/%d/fd/%d", pid
, fd
);
4447 if (stat (path
, &st
) != 0)
4449 if (!S_ISDIR (st
.st_mode
))
4452 if (statfs (path
, &stfs
) != 0)
4454 if (stfs
.f_type
!= SPUFS_MAGIC
)
4457 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4459 store_unsigned_integer (buf
+ pos
- offset
, 4, byte_order
, fd
);
4469 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4470 object type, using the /proc file system. */
4472 linux_proc_xfer_spu (struct target_ops
*ops
, enum target_object object
,
4473 const char *annex
, gdb_byte
*readbuf
,
4474 const gdb_byte
*writebuf
,
4475 ULONGEST offset
, LONGEST len
)
4480 int pid
= PIDGET (inferior_ptid
);
4487 return spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4490 xsnprintf (buf
, sizeof buf
, "/proc/%d/fd/%s", pid
, annex
);
4491 fd
= open (buf
, writebuf
? O_WRONLY
: O_RDONLY
);
4496 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4503 ret
= write (fd
, writebuf
, (size_t) len
);
4505 ret
= read (fd
, readbuf
, (size_t) len
);
4512 /* Parse LINE as a signal set and add its set bits to SIGS. */
4515 add_line_to_sigset (const char *line
, sigset_t
*sigs
)
4517 int len
= strlen (line
) - 1;
4521 if (line
[len
] != '\n')
4522 error (_("Could not parse signal set: %s"), line
);
4530 if (*p
>= '0' && *p
<= '9')
4532 else if (*p
>= 'a' && *p
<= 'f')
4533 digit
= *p
- 'a' + 10;
4535 error (_("Could not parse signal set: %s"), line
);
4540 sigaddset (sigs
, signum
+ 1);
4542 sigaddset (sigs
, signum
+ 2);
4544 sigaddset (sigs
, signum
+ 3);
4546 sigaddset (sigs
, signum
+ 4);
4552 /* Find process PID's pending signals from /proc/pid/status and set
4556 linux_proc_pending_signals (int pid
, sigset_t
*pending
,
4557 sigset_t
*blocked
, sigset_t
*ignored
)
4560 char buffer
[MAXPATHLEN
], fname
[MAXPATHLEN
];
4561 struct cleanup
*cleanup
;
4563 sigemptyset (pending
);
4564 sigemptyset (blocked
);
4565 sigemptyset (ignored
);
4566 sprintf (fname
, "/proc/%d/status", pid
);
4567 procfile
= fopen (fname
, "r");
4568 if (procfile
== NULL
)
4569 error (_("Could not open %s"), fname
);
4570 cleanup
= make_cleanup_fclose (procfile
);
4572 while (fgets (buffer
, MAXPATHLEN
, procfile
) != NULL
)
4574 /* Normal queued signals are on the SigPnd line in the status
4575 file. However, 2.6 kernels also have a "shared" pending
4576 queue for delivering signals to a thread group, so check for
4579 Unfortunately some Red Hat kernels include the shared pending
4580 queue but not the ShdPnd status field. */
4582 if (strncmp (buffer
, "SigPnd:\t", 8) == 0)
4583 add_line_to_sigset (buffer
+ 8, pending
);
4584 else if (strncmp (buffer
, "ShdPnd:\t", 8) == 0)
4585 add_line_to_sigset (buffer
+ 8, pending
);
4586 else if (strncmp (buffer
, "SigBlk:\t", 8) == 0)
4587 add_line_to_sigset (buffer
+ 8, blocked
);
4588 else if (strncmp (buffer
, "SigIgn:\t", 8) == 0)
4589 add_line_to_sigset (buffer
+ 8, ignored
);
4592 do_cleanups (cleanup
);
4596 linux_nat_xfer_osdata (struct target_ops
*ops
, enum target_object object
,
4597 const char *annex
, gdb_byte
*readbuf
,
4598 const gdb_byte
*writebuf
, ULONGEST offset
, LONGEST len
)
4600 gdb_assert (object
== TARGET_OBJECT_OSDATA
);
4602 return linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
4606 linux_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4607 const char *annex
, gdb_byte
*readbuf
,
4608 const gdb_byte
*writebuf
, ULONGEST offset
, LONGEST len
)
4612 if (object
== TARGET_OBJECT_AUXV
)
4613 return memory_xfer_auxv (ops
, object
, annex
, readbuf
, writebuf
,
4616 if (object
== TARGET_OBJECT_OSDATA
)
4617 return linux_nat_xfer_osdata (ops
, object
, annex
, readbuf
, writebuf
,
4620 if (object
== TARGET_OBJECT_SPU
)
4621 return linux_proc_xfer_spu (ops
, object
, annex
, readbuf
, writebuf
,
4624 /* GDB calculates all the addresses in possibly larget width of the address.
4625 Address width needs to be masked before its final use - either by
4626 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4628 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4630 if (object
== TARGET_OBJECT_MEMORY
)
4632 int addr_bit
= gdbarch_addr_bit (target_gdbarch
);
4634 if (addr_bit
< (sizeof (ULONGEST
) * HOST_CHAR_BIT
))
4635 offset
&= ((ULONGEST
) 1 << addr_bit
) - 1;
4638 xfer
= linux_proc_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4643 return super_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4648 cleanup_target_stop (void *arg
)
4650 ptid_t
*ptid
= (ptid_t
*) arg
;
4652 gdb_assert (arg
!= NULL
);
4655 target_resume (*ptid
, 0, GDB_SIGNAL_0
);
4658 static VEC(static_tracepoint_marker_p
) *
4659 linux_child_static_tracepoint_markers_by_strid (const char *strid
)
4661 char s
[IPA_CMD_BUF_SIZE
];
4662 struct cleanup
*old_chain
;
4663 int pid
= ptid_get_pid (inferior_ptid
);
4664 VEC(static_tracepoint_marker_p
) *markers
= NULL
;
4665 struct static_tracepoint_marker
*marker
= NULL
;
4667 ptid_t ptid
= ptid_build (pid
, 0, 0);
4672 memcpy (s
, "qTfSTM", sizeof ("qTfSTM"));
4673 s
[sizeof ("qTfSTM")] = 0;
4675 agent_run_command (pid
, s
, strlen (s
) + 1);
4677 old_chain
= make_cleanup (free_current_marker
, &marker
);
4678 make_cleanup (cleanup_target_stop
, &ptid
);
4683 marker
= XCNEW (struct static_tracepoint_marker
);
4687 parse_static_tracepoint_marker_definition (p
, &p
, marker
);
4689 if (strid
== NULL
|| strcmp (strid
, marker
->str_id
) == 0)
4691 VEC_safe_push (static_tracepoint_marker_p
,
4697 release_static_tracepoint_marker (marker
);
4698 memset (marker
, 0, sizeof (*marker
));
4701 while (*p
++ == ','); /* comma-separated list */
4703 memcpy (s
, "qTsSTM", sizeof ("qTsSTM"));
4704 s
[sizeof ("qTsSTM")] = 0;
4705 agent_run_command (pid
, s
, strlen (s
) + 1);
4709 do_cleanups (old_chain
);
4714 /* Create a prototype generic GNU/Linux target. The client can override
4715 it with local methods. */
4718 linux_target_install_ops (struct target_ops
*t
)
4720 t
->to_insert_fork_catchpoint
= linux_child_insert_fork_catchpoint
;
4721 t
->to_remove_fork_catchpoint
= linux_child_remove_fork_catchpoint
;
4722 t
->to_insert_vfork_catchpoint
= linux_child_insert_vfork_catchpoint
;
4723 t
->to_remove_vfork_catchpoint
= linux_child_remove_vfork_catchpoint
;
4724 t
->to_insert_exec_catchpoint
= linux_child_insert_exec_catchpoint
;
4725 t
->to_remove_exec_catchpoint
= linux_child_remove_exec_catchpoint
;
4726 t
->to_set_syscall_catchpoint
= linux_child_set_syscall_catchpoint
;
4727 t
->to_pid_to_exec_file
= linux_child_pid_to_exec_file
;
4728 t
->to_post_startup_inferior
= linux_child_post_startup_inferior
;
4729 t
->to_post_attach
= linux_child_post_attach
;
4730 t
->to_follow_fork
= linux_child_follow_fork
;
4731 t
->to_make_corefile_notes
= linux_nat_make_corefile_notes
;
4733 super_xfer_partial
= t
->to_xfer_partial
;
4734 t
->to_xfer_partial
= linux_xfer_partial
;
4736 t
->to_static_tracepoint_markers_by_strid
4737 = linux_child_static_tracepoint_markers_by_strid
;
4743 struct target_ops
*t
;
4745 t
= inf_ptrace_target ();
4746 linux_target_install_ops (t
);
4752 linux_trad_target (CORE_ADDR (*register_u_offset
)(struct gdbarch
*, int, int))
4754 struct target_ops
*t
;
4756 t
= inf_ptrace_trad_target (register_u_offset
);
4757 linux_target_install_ops (t
);
4762 /* target_is_async_p implementation. */
4765 linux_nat_is_async_p (void)
4767 /* NOTE: palves 2008-03-21: We're only async when the user requests
4768 it explicitly with the "set target-async" command.
4769 Someday, linux will always be async. */
4770 return target_async_permitted
;
4773 /* target_can_async_p implementation. */
4776 linux_nat_can_async_p (void)
4778 /* NOTE: palves 2008-03-21: We're only async when the user requests
4779 it explicitly with the "set target-async" command.
4780 Someday, linux will always be async. */
4781 return target_async_permitted
;
4785 linux_nat_supports_non_stop (void)
4790 /* True if we want to support multi-process. To be removed when GDB
4791 supports multi-exec. */
4793 int linux_multi_process
= 1;
4796 linux_nat_supports_multi_process (void)
4798 return linux_multi_process
;
4802 linux_nat_supports_disable_randomization (void)
4804 #ifdef HAVE_PERSONALITY
4811 static int async_terminal_is_ours
= 1;
4813 /* target_terminal_inferior implementation. */
4816 linux_nat_terminal_inferior (void)
4818 if (!target_is_async_p ())
4820 /* Async mode is disabled. */
4821 terminal_inferior ();
4825 terminal_inferior ();
4827 /* Calls to target_terminal_*() are meant to be idempotent. */
4828 if (!async_terminal_is_ours
)
4831 delete_file_handler (input_fd
);
4832 async_terminal_is_ours
= 0;
4836 /* target_terminal_ours implementation. */
4839 linux_nat_terminal_ours (void)
4841 if (!target_is_async_p ())
4843 /* Async mode is disabled. */
4848 /* GDB should never give the terminal to the inferior if the
4849 inferior is running in the background (run&, continue&, etc.),
4850 but claiming it sure should. */
4853 if (async_terminal_is_ours
)
4856 clear_sigint_trap ();
4857 add_file_handler (input_fd
, stdin_event_handler
, 0);
4858 async_terminal_is_ours
= 1;
4861 static void (*async_client_callback
) (enum inferior_event_type event_type
,
4863 static void *async_client_context
;
4865 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4866 so we notice when any child changes state, and notify the
4867 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4868 above to wait for the arrival of a SIGCHLD. */
4871 sigchld_handler (int signo
)
4873 int old_errno
= errno
;
4875 if (debug_linux_nat
)
4876 ui_file_write_async_safe (gdb_stdlog
,
4877 "sigchld\n", sizeof ("sigchld\n") - 1);
4879 if (signo
== SIGCHLD
4880 && linux_nat_event_pipe
[0] != -1)
4881 async_file_mark (); /* Let the event loop know that there are
4882 events to handle. */
4887 /* Callback registered with the target events file descriptor. */
4890 handle_target_event (int error
, gdb_client_data client_data
)
4892 (*async_client_callback
) (INF_REG_EVENT
, async_client_context
);
4895 /* Create/destroy the target events pipe. Returns previous state. */
4898 linux_async_pipe (int enable
)
4900 int previous
= (linux_nat_event_pipe
[0] != -1);
4902 if (previous
!= enable
)
4906 block_child_signals (&prev_mask
);
4910 if (pipe (linux_nat_event_pipe
) == -1)
4911 internal_error (__FILE__
, __LINE__
,
4912 "creating event pipe failed.");
4914 fcntl (linux_nat_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4915 fcntl (linux_nat_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4919 close (linux_nat_event_pipe
[0]);
4920 close (linux_nat_event_pipe
[1]);
4921 linux_nat_event_pipe
[0] = -1;
4922 linux_nat_event_pipe
[1] = -1;
4925 restore_child_signals_mask (&prev_mask
);
4931 /* target_async implementation. */
4934 linux_nat_async (void (*callback
) (enum inferior_event_type event_type
,
4935 void *context
), void *context
)
4937 if (callback
!= NULL
)
4939 async_client_callback
= callback
;
4940 async_client_context
= context
;
4941 if (!linux_async_pipe (1))
4943 add_file_handler (linux_nat_event_pipe
[0],
4944 handle_target_event
, NULL
);
4945 /* There may be pending events to handle. Tell the event loop
4952 async_client_callback
= callback
;
4953 async_client_context
= context
;
4954 delete_file_handler (linux_nat_event_pipe
[0]);
4955 linux_async_pipe (0);
4960 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4964 linux_nat_stop_lwp (struct lwp_info
*lwp
, void *data
)
4968 ptid_t ptid
= lwp
->ptid
;
4970 if (debug_linux_nat
)
4971 fprintf_unfiltered (gdb_stdlog
,
4972 "LNSL: running -> suspending %s\n",
4973 target_pid_to_str (lwp
->ptid
));
4976 if (lwp
->last_resume_kind
== resume_stop
)
4978 if (debug_linux_nat
)
4979 fprintf_unfiltered (gdb_stdlog
,
4980 "linux-nat: already stopping LWP %ld at "
4982 ptid_get_lwp (lwp
->ptid
));
4986 stop_callback (lwp
, NULL
);
4987 lwp
->last_resume_kind
= resume_stop
;
4991 /* Already known to be stopped; do nothing. */
4993 if (debug_linux_nat
)
4995 if (find_thread_ptid (lwp
->ptid
)->stop_requested
)
4996 fprintf_unfiltered (gdb_stdlog
,
4997 "LNSL: already stopped/stop_requested %s\n",
4998 target_pid_to_str (lwp
->ptid
));
5000 fprintf_unfiltered (gdb_stdlog
,
5001 "LNSL: already stopped/no "
5002 "stop_requested yet %s\n",
5003 target_pid_to_str (lwp
->ptid
));
5010 linux_nat_stop (ptid_t ptid
)
5013 iterate_over_lwps (ptid
, linux_nat_stop_lwp
, NULL
);
5015 linux_ops
->to_stop (ptid
);
5019 linux_nat_close (int quitting
)
5021 /* Unregister from the event loop. */
5022 if (linux_nat_is_async_p ())
5023 linux_nat_async (NULL
, 0);
5025 if (linux_ops
->to_close
)
5026 linux_ops
->to_close (quitting
);
5029 /* When requests are passed down from the linux-nat layer to the
5030 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
5031 used. The address space pointer is stored in the inferior object,
5032 but the common code that is passed such ptid can't tell whether
5033 lwpid is a "main" process id or not (it assumes so). We reverse
5034 look up the "main" process id from the lwp here. */
5036 static struct address_space
*
5037 linux_nat_thread_address_space (struct target_ops
*t
, ptid_t ptid
)
5039 struct lwp_info
*lwp
;
5040 struct inferior
*inf
;
5043 pid
= GET_LWP (ptid
);
5044 if (GET_LWP (ptid
) == 0)
5046 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
5048 lwp
= find_lwp_pid (ptid
);
5049 pid
= GET_PID (lwp
->ptid
);
5053 /* A (pid,lwpid,0) ptid. */
5054 pid
= GET_PID (ptid
);
5057 inf
= find_inferior_pid (pid
);
5058 gdb_assert (inf
!= NULL
);
5062 /* Return the cached value of the processor core for thread PTID. */
5065 linux_nat_core_of_thread (struct target_ops
*ops
, ptid_t ptid
)
5067 struct lwp_info
*info
= find_lwp_pid (ptid
);
5075 linux_nat_add_target (struct target_ops
*t
)
5077 /* Save the provided single-threaded target. We save this in a separate
5078 variable because another target we've inherited from (e.g. inf-ptrace)
5079 may have saved a pointer to T; we want to use it for the final
5080 process stratum target. */
5081 linux_ops_saved
= *t
;
5082 linux_ops
= &linux_ops_saved
;
5084 /* Override some methods for multithreading. */
5085 t
->to_create_inferior
= linux_nat_create_inferior
;
5086 t
->to_attach
= linux_nat_attach
;
5087 t
->to_detach
= linux_nat_detach
;
5088 t
->to_resume
= linux_nat_resume
;
5089 t
->to_wait
= linux_nat_wait
;
5090 t
->to_pass_signals
= linux_nat_pass_signals
;
5091 t
->to_xfer_partial
= linux_nat_xfer_partial
;
5092 t
->to_kill
= linux_nat_kill
;
5093 t
->to_mourn_inferior
= linux_nat_mourn_inferior
;
5094 t
->to_thread_alive
= linux_nat_thread_alive
;
5095 t
->to_pid_to_str
= linux_nat_pid_to_str
;
5096 t
->to_thread_name
= linux_nat_thread_name
;
5097 t
->to_has_thread_control
= tc_schedlock
;
5098 t
->to_thread_address_space
= linux_nat_thread_address_space
;
5099 t
->to_stopped_by_watchpoint
= linux_nat_stopped_by_watchpoint
;
5100 t
->to_stopped_data_address
= linux_nat_stopped_data_address
;
5102 t
->to_can_async_p
= linux_nat_can_async_p
;
5103 t
->to_is_async_p
= linux_nat_is_async_p
;
5104 t
->to_supports_non_stop
= linux_nat_supports_non_stop
;
5105 t
->to_async
= linux_nat_async
;
5106 t
->to_terminal_inferior
= linux_nat_terminal_inferior
;
5107 t
->to_terminal_ours
= linux_nat_terminal_ours
;
5108 t
->to_close
= linux_nat_close
;
5110 /* Methods for non-stop support. */
5111 t
->to_stop
= linux_nat_stop
;
5113 t
->to_supports_multi_process
= linux_nat_supports_multi_process
;
5115 t
->to_supports_disable_randomization
5116 = linux_nat_supports_disable_randomization
;
5118 t
->to_core_of_thread
= linux_nat_core_of_thread
;
5120 /* We don't change the stratum; this target will sit at
5121 process_stratum and thread_db will set at thread_stratum. This
5122 is a little strange, since this is a multi-threaded-capable
5123 target, but we want to be on the stack below thread_db, and we
5124 also want to be used for single-threaded processes. */
5129 /* Register a method to call whenever a new thread is attached. */
5131 linux_nat_set_new_thread (struct target_ops
*t
,
5132 void (*new_thread
) (struct lwp_info
*))
5134 /* Save the pointer. We only support a single registered instance
5135 of the GNU/Linux native target, so we do not need to map this to
5137 linux_nat_new_thread
= new_thread
;
5140 /* Register a method that converts a siginfo object between the layout
5141 that ptrace returns, and the layout in the architecture of the
5144 linux_nat_set_siginfo_fixup (struct target_ops
*t
,
5145 int (*siginfo_fixup
) (siginfo_t
*,
5149 /* Save the pointer. */
5150 linux_nat_siginfo_fixup
= siginfo_fixup
;
5153 /* Register a method to call prior to resuming a thread. */
5156 linux_nat_set_prepare_to_resume (struct target_ops
*t
,
5157 void (*prepare_to_resume
) (struct lwp_info
*))
5159 /* Save the pointer. */
5160 linux_nat_prepare_to_resume
= prepare_to_resume
;
5163 /* See linux-nat.h. */
5166 linux_nat_get_siginfo (ptid_t ptid
, siginfo_t
*siginfo
)
5170 pid
= GET_LWP (ptid
);
5172 pid
= GET_PID (ptid
);
5175 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, siginfo
);
5178 memset (siginfo
, 0, sizeof (*siginfo
));
5184 /* Provide a prototype to silence -Wmissing-prototypes. */
5185 extern initialize_file_ftype _initialize_linux_nat
;
5188 _initialize_linux_nat (void)
5190 add_setshow_zinteger_cmd ("lin-lwp", class_maintenance
,
5191 &debug_linux_nat
, _("\
5192 Set debugging of GNU/Linux lwp module."), _("\
5193 Show debugging of GNU/Linux lwp module."), _("\
5194 Enables printf debugging output."),
5196 show_debug_linux_nat
,
5197 &setdebuglist
, &showdebuglist
);
5199 /* Save this mask as the default. */
5200 sigprocmask (SIG_SETMASK
, NULL
, &normal_mask
);
5202 /* Install a SIGCHLD handler. */
5203 sigchld_action
.sa_handler
= sigchld_handler
;
5204 sigemptyset (&sigchld_action
.sa_mask
);
5205 sigchld_action
.sa_flags
= SA_RESTART
;
5207 /* Make it the default. */
5208 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
5210 /* Make sure we don't block SIGCHLD during a sigsuspend. */
5211 sigprocmask (SIG_SETMASK
, NULL
, &suspend_mask
);
5212 sigdelset (&suspend_mask
, SIGCHLD
);
5214 sigemptyset (&blocked_mask
);
5218 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
5219 the GNU/Linux Threads library and therefore doesn't really belong
5222 /* Read variable NAME in the target and return its value if found.
5223 Otherwise return zero. It is assumed that the type of the variable
5227 get_signo (const char *name
)
5229 struct minimal_symbol
*ms
;
5232 ms
= lookup_minimal_symbol (name
, NULL
, NULL
);
5236 if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms
), (gdb_byte
*) &signo
,
5237 sizeof (signo
)) != 0)
5243 /* Return the set of signals used by the threads library in *SET. */
5246 lin_thread_get_thread_signals (sigset_t
*set
)
5248 struct sigaction action
;
5249 int restart
, cancel
;
5251 sigemptyset (&blocked_mask
);
5254 restart
= get_signo ("__pthread_sig_restart");
5255 cancel
= get_signo ("__pthread_sig_cancel");
5257 /* LinuxThreads normally uses the first two RT signals, but in some legacy
5258 cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
5259 not provide any way for the debugger to query the signal numbers -
5260 fortunately they don't change! */
5263 restart
= __SIGRTMIN
;
5266 cancel
= __SIGRTMIN
+ 1;
5268 sigaddset (set
, restart
);
5269 sigaddset (set
, cancel
);
5271 /* The GNU/Linux Threads library makes terminating threads send a
5272 special "cancel" signal instead of SIGCHLD. Make sure we catch
5273 those (to prevent them from terminating GDB itself, which is
5274 likely to be their default action) and treat them the same way as
5277 action
.sa_handler
= sigchld_handler
;
5278 sigemptyset (&action
.sa_mask
);
5279 action
.sa_flags
= SA_RESTART
;
5280 sigaction (cancel
, &action
, NULL
);
5282 /* We block the "cancel" signal throughout this code ... */
5283 sigaddset (&blocked_mask
, cancel
);
5284 sigprocmask (SIG_BLOCK
, &blocked_mask
, NULL
);
5286 /* ... except during a sigsuspend. */
5287 sigdelset (&suspend_mask
, cancel
);