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
));
586 linux_ptrace_init_warnings ();
590 linux_child_post_startup_inferior (ptid_t ptid
)
592 linux_enable_event_reporting (ptid
);
593 linux_enable_tracesysgood (ptid
);
594 linux_ptrace_init_warnings ();
597 /* Return the number of known LWPs in the tgid given by PID. */
605 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
606 if (ptid_get_pid (lp
->ptid
) == pid
)
612 /* Call delete_lwp with prototype compatible for make_cleanup. */
615 delete_lwp_cleanup (void *lp_voidp
)
617 struct lwp_info
*lp
= lp_voidp
;
619 delete_lwp (lp
->ptid
);
623 linux_child_follow_fork (struct target_ops
*ops
, int follow_child
)
627 int parent_pid
, child_pid
;
629 block_child_signals (&prev_mask
);
631 has_vforked
= (inferior_thread ()->pending_follow
.kind
632 == TARGET_WAITKIND_VFORKED
);
633 parent_pid
= ptid_get_lwp (inferior_ptid
);
635 parent_pid
= ptid_get_pid (inferior_ptid
);
636 child_pid
= PIDGET (inferior_thread ()->pending_follow
.value
.related_pid
);
639 linux_enable_event_reporting (pid_to_ptid (child_pid
));
642 && !non_stop
/* Non-stop always resumes both branches. */
643 && (!target_is_async_p () || sync_execution
)
644 && !(follow_child
|| detach_fork
|| sched_multi
))
646 /* The parent stays blocked inside the vfork syscall until the
647 child execs or exits. If we don't let the child run, then
648 the parent stays blocked. If we're telling the parent to run
649 in the foreground, the user will not be able to ctrl-c to get
650 back the terminal, effectively hanging the debug session. */
651 fprintf_filtered (gdb_stderr
, _("\
652 Can not resume the parent process over vfork in the foreground while\n\
653 holding the child stopped. Try \"set detach-on-fork\" or \
654 \"set schedule-multiple\".\n"));
655 /* FIXME output string > 80 columns. */
661 struct lwp_info
*child_lp
= NULL
;
663 /* We're already attached to the parent, by default. */
665 /* Detach new forked process? */
668 struct cleanup
*old_chain
;
670 /* Before detaching from the child, remove all breakpoints
671 from it. If we forked, then this has already been taken
672 care of by infrun.c. If we vforked however, any
673 breakpoint inserted in the parent is visible in the
674 child, even those added while stopped in a vfork
675 catchpoint. This will remove the breakpoints from the
676 parent also, but they'll be reinserted below. */
679 /* keep breakpoints list in sync. */
680 remove_breakpoints_pid (GET_PID (inferior_ptid
));
683 if (info_verbose
|| debug_linux_nat
)
685 target_terminal_ours ();
686 fprintf_filtered (gdb_stdlog
,
687 "Detaching after fork from "
688 "child process %d.\n",
692 old_chain
= save_inferior_ptid ();
693 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
695 child_lp
= add_lwp (inferior_ptid
);
696 child_lp
->stopped
= 1;
697 child_lp
->last_resume_kind
= resume_stop
;
698 make_cleanup (delete_lwp_cleanup
, child_lp
);
700 /* CHILD_LP has new PID, therefore linux_nat_new_thread is not called for it.
701 See i386_inferior_data_get for the Linux kernel specifics.
702 Ensure linux_nat_prepare_to_resume will reset the hardware debug
703 registers. It is done by the linux_nat_new_thread call, which is
704 being skipped in add_lwp above for the first lwp of a pid. */
705 gdb_assert (num_lwps (GET_PID (child_lp
->ptid
)) == 1);
706 if (linux_nat_new_thread
!= NULL
)
707 linux_nat_new_thread (child_lp
);
709 if (linux_nat_prepare_to_resume
!= NULL
)
710 linux_nat_prepare_to_resume (child_lp
);
711 ptrace (PTRACE_DETACH
, child_pid
, 0, 0);
713 do_cleanups (old_chain
);
717 struct inferior
*parent_inf
, *child_inf
;
718 struct cleanup
*old_chain
;
720 /* Add process to GDB's tables. */
721 child_inf
= add_inferior (child_pid
);
723 parent_inf
= current_inferior ();
724 child_inf
->attach_flag
= parent_inf
->attach_flag
;
725 copy_terminal_info (child_inf
, parent_inf
);
727 old_chain
= save_inferior_ptid ();
728 save_current_program_space ();
730 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
731 add_thread (inferior_ptid
);
732 child_lp
= add_lwp (inferior_ptid
);
733 child_lp
->stopped
= 1;
734 child_lp
->last_resume_kind
= resume_stop
;
735 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
737 /* If this is a vfork child, then the address-space is
738 shared with the parent. */
741 child_inf
->pspace
= parent_inf
->pspace
;
742 child_inf
->aspace
= parent_inf
->aspace
;
744 /* The parent will be frozen until the child is done
745 with the shared region. Keep track of the
747 child_inf
->vfork_parent
= parent_inf
;
748 child_inf
->pending_detach
= 0;
749 parent_inf
->vfork_child
= child_inf
;
750 parent_inf
->pending_detach
= 0;
754 child_inf
->aspace
= new_address_space ();
755 child_inf
->pspace
= add_program_space (child_inf
->aspace
);
756 child_inf
->removable
= 1;
757 set_current_program_space (child_inf
->pspace
);
758 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
760 /* Let the shared library layer (solib-svr4) learn about
761 this new process, relocate the cloned exec, pull in
762 shared libraries, and install the solib event
763 breakpoint. If a "cloned-VM" event was propagated
764 better throughout the core, this wouldn't be
766 solib_create_inferior_hook (0);
769 /* Let the thread_db layer learn about this new process. */
770 check_for_thread_db ();
772 do_cleanups (old_chain
);
777 struct lwp_info
*parent_lp
;
778 struct inferior
*parent_inf
;
780 parent_inf
= current_inferior ();
782 /* If we detached from the child, then we have to be careful
783 to not insert breakpoints in the parent until the child
784 is done with the shared memory region. However, if we're
785 staying attached to the child, then we can and should
786 insert breakpoints, so that we can debug it. A
787 subsequent child exec or exit is enough to know when does
788 the child stops using the parent's address space. */
789 parent_inf
->waiting_for_vfork_done
= detach_fork
;
790 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
792 parent_lp
= find_lwp_pid (pid_to_ptid (parent_pid
));
793 gdb_assert (linux_supports_tracefork_flag
>= 0);
795 if (linux_supports_tracevforkdone (0))
798 fprintf_unfiltered (gdb_stdlog
,
799 "LCFF: waiting for VFORK_DONE on %d\n",
801 parent_lp
->stopped
= 1;
803 /* We'll handle the VFORK_DONE event like any other
804 event, in target_wait. */
808 /* We can't insert breakpoints until the child has
809 finished with the shared memory region. We need to
810 wait until that happens. Ideal would be to just
812 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
813 - waitpid (parent_pid, &status, __WALL);
814 However, most architectures can't handle a syscall
815 being traced on the way out if it wasn't traced on
818 We might also think to loop, continuing the child
819 until it exits or gets a SIGTRAP. One problem is
820 that the child might call ptrace with PTRACE_TRACEME.
822 There's no simple and reliable way to figure out when
823 the vforked child will be done with its copy of the
824 shared memory. We could step it out of the syscall,
825 two instructions, let it go, and then single-step the
826 parent once. When we have hardware single-step, this
827 would work; with software single-step it could still
828 be made to work but we'd have to be able to insert
829 single-step breakpoints in the child, and we'd have
830 to insert -just- the single-step breakpoint in the
831 parent. Very awkward.
833 In the end, the best we can do is to make sure it
834 runs for a little while. Hopefully it will be out of
835 range of any breakpoints we reinsert. Usually this
836 is only the single-step breakpoint at vfork's return
840 fprintf_unfiltered (gdb_stdlog
,
841 "LCFF: no VFORK_DONE "
842 "support, sleeping a bit\n");
846 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
847 and leave it pending. The next linux_nat_resume call
848 will notice a pending event, and bypasses actually
849 resuming the inferior. */
850 parent_lp
->status
= 0;
851 parent_lp
->waitstatus
.kind
= TARGET_WAITKIND_VFORK_DONE
;
852 parent_lp
->stopped
= 1;
854 /* If we're in async mode, need to tell the event loop
855 there's something here to process. */
856 if (target_can_async_p ())
863 struct inferior
*parent_inf
, *child_inf
;
864 struct lwp_info
*child_lp
;
865 struct program_space
*parent_pspace
;
867 if (info_verbose
|| debug_linux_nat
)
869 target_terminal_ours ();
871 fprintf_filtered (gdb_stdlog
,
872 _("Attaching after process %d "
873 "vfork to child process %d.\n"),
874 parent_pid
, child_pid
);
876 fprintf_filtered (gdb_stdlog
,
877 _("Attaching after process %d "
878 "fork to child process %d.\n"),
879 parent_pid
, child_pid
);
882 /* Add the new inferior first, so that the target_detach below
883 doesn't unpush the target. */
885 child_inf
= add_inferior (child_pid
);
887 parent_inf
= current_inferior ();
888 child_inf
->attach_flag
= parent_inf
->attach_flag
;
889 copy_terminal_info (child_inf
, parent_inf
);
891 parent_pspace
= parent_inf
->pspace
;
893 /* If we're vforking, we want to hold on to the parent until the
894 child exits or execs. At child exec or exit time we can
895 remove the old breakpoints from the parent and detach or
896 resume debugging it. Otherwise, detach the parent now; we'll
897 want to reuse it's program/address spaces, but we can't set
898 them to the child before removing breakpoints from the
899 parent, otherwise, the breakpoints module could decide to
900 remove breakpoints from the wrong process (since they'd be
901 assigned to the same address space). */
905 gdb_assert (child_inf
->vfork_parent
== NULL
);
906 gdb_assert (parent_inf
->vfork_child
== NULL
);
907 child_inf
->vfork_parent
= parent_inf
;
908 child_inf
->pending_detach
= 0;
909 parent_inf
->vfork_child
= child_inf
;
910 parent_inf
->pending_detach
= detach_fork
;
911 parent_inf
->waiting_for_vfork_done
= 0;
913 else if (detach_fork
)
914 target_detach (NULL
, 0);
916 /* Note that the detach above makes PARENT_INF dangling. */
918 /* Add the child thread to the appropriate lists, and switch to
919 this new thread, before cloning the program space, and
920 informing the solib layer about this new process. */
922 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
923 add_thread (inferior_ptid
);
924 child_lp
= add_lwp (inferior_ptid
);
925 child_lp
->stopped
= 1;
926 child_lp
->last_resume_kind
= resume_stop
;
928 /* If this is a vfork child, then the address-space is shared
929 with the parent. If we detached from the parent, then we can
930 reuse the parent's program/address spaces. */
931 if (has_vforked
|| detach_fork
)
933 child_inf
->pspace
= parent_pspace
;
934 child_inf
->aspace
= child_inf
->pspace
->aspace
;
938 child_inf
->aspace
= new_address_space ();
939 child_inf
->pspace
= add_program_space (child_inf
->aspace
);
940 child_inf
->removable
= 1;
941 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
942 set_current_program_space (child_inf
->pspace
);
943 clone_program_space (child_inf
->pspace
, parent_pspace
);
945 /* Let the shared library layer (solib-svr4) learn about
946 this new process, relocate the cloned exec, pull in
947 shared libraries, and install the solib event breakpoint.
948 If a "cloned-VM" event was propagated better throughout
949 the core, this wouldn't be required. */
950 solib_create_inferior_hook (0);
953 /* Let the thread_db layer learn about this new process. */
954 check_for_thread_db ();
957 restore_child_signals_mask (&prev_mask
);
963 linux_child_insert_fork_catchpoint (int pid
)
965 return !linux_supports_tracefork (pid
);
969 linux_child_remove_fork_catchpoint (int pid
)
975 linux_child_insert_vfork_catchpoint (int pid
)
977 return !linux_supports_tracefork (pid
);
981 linux_child_remove_vfork_catchpoint (int pid
)
987 linux_child_insert_exec_catchpoint (int pid
)
989 return !linux_supports_tracefork (pid
);
993 linux_child_remove_exec_catchpoint (int pid
)
999 linux_child_set_syscall_catchpoint (int pid
, int needed
, int any_count
,
1000 int table_size
, int *table
)
1002 if (!linux_supports_tracesysgood (pid
))
1005 /* On GNU/Linux, we ignore the arguments. It means that we only
1006 enable the syscall catchpoints, but do not disable them.
1008 Also, we do not use the `table' information because we do not
1009 filter system calls here. We let GDB do the logic for us. */
1013 /* On GNU/Linux there are no real LWP's. The closest thing to LWP's
1014 are processes sharing the same VM space. A multi-threaded process
1015 is basically a group of such processes. However, such a grouping
1016 is almost entirely a user-space issue; the kernel doesn't enforce
1017 such a grouping at all (this might change in the future). In
1018 general, we'll rely on the threads library (i.e. the GNU/Linux
1019 Threads library) to provide such a grouping.
1021 It is perfectly well possible to write a multi-threaded application
1022 without the assistance of a threads library, by using the clone
1023 system call directly. This module should be able to give some
1024 rudimentary support for debugging such applications if developers
1025 specify the CLONE_PTRACE flag in the clone system call, and are
1026 using the Linux kernel 2.4 or above.
1028 Note that there are some peculiarities in GNU/Linux that affect
1031 - In general one should specify the __WCLONE flag to waitpid in
1032 order to make it report events for any of the cloned processes
1033 (and leave it out for the initial process). However, if a cloned
1034 process has exited the exit status is only reported if the
1035 __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
1036 we cannot use it since GDB must work on older systems too.
1038 - When a traced, cloned process exits and is waited for by the
1039 debugger, the kernel reassigns it to the original parent and
1040 keeps it around as a "zombie". Somehow, the GNU/Linux Threads
1041 library doesn't notice this, which leads to the "zombie problem":
1042 When debugged a multi-threaded process that spawns a lot of
1043 threads will run out of processes, even if the threads exit,
1044 because the "zombies" stay around. */
1046 /* List of known LWPs. */
1047 struct lwp_info
*lwp_list
;
1050 /* Original signal mask. */
1051 static sigset_t normal_mask
;
1053 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
1054 _initialize_linux_nat. */
1055 static sigset_t suspend_mask
;
1057 /* Signals to block to make that sigsuspend work. */
1058 static sigset_t blocked_mask
;
1060 /* SIGCHLD action. */
1061 struct sigaction sigchld_action
;
1063 /* Block child signals (SIGCHLD and linux threads signals), and store
1064 the previous mask in PREV_MASK. */
1067 block_child_signals (sigset_t
*prev_mask
)
1069 /* Make sure SIGCHLD is blocked. */
1070 if (!sigismember (&blocked_mask
, SIGCHLD
))
1071 sigaddset (&blocked_mask
, SIGCHLD
);
1073 sigprocmask (SIG_BLOCK
, &blocked_mask
, prev_mask
);
1076 /* Restore child signals mask, previously returned by
1077 block_child_signals. */
1080 restore_child_signals_mask (sigset_t
*prev_mask
)
1082 sigprocmask (SIG_SETMASK
, prev_mask
, NULL
);
1085 /* Mask of signals to pass directly to the inferior. */
1086 static sigset_t pass_mask
;
1088 /* Update signals to pass to the inferior. */
1090 linux_nat_pass_signals (int numsigs
, unsigned char *pass_signals
)
1094 sigemptyset (&pass_mask
);
1096 for (signo
= 1; signo
< NSIG
; signo
++)
1098 int target_signo
= gdb_signal_from_host (signo
);
1099 if (target_signo
< numsigs
&& pass_signals
[target_signo
])
1100 sigaddset (&pass_mask
, signo
);
1106 /* Prototypes for local functions. */
1107 static int stop_wait_callback (struct lwp_info
*lp
, void *data
);
1108 static int linux_thread_alive (ptid_t ptid
);
1109 static char *linux_child_pid_to_exec_file (int pid
);
1112 /* Convert wait status STATUS to a string. Used for printing debug
1116 status_to_str (int status
)
1118 static char buf
[64];
1120 if (WIFSTOPPED (status
))
1122 if (WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
1123 snprintf (buf
, sizeof (buf
), "%s (stopped at syscall)",
1124 strsignal (SIGTRAP
));
1126 snprintf (buf
, sizeof (buf
), "%s (stopped)",
1127 strsignal (WSTOPSIG (status
)));
1129 else if (WIFSIGNALED (status
))
1130 snprintf (buf
, sizeof (buf
), "%s (terminated)",
1131 strsignal (WTERMSIG (status
)));
1133 snprintf (buf
, sizeof (buf
), "%d (exited)", WEXITSTATUS (status
));
1138 /* Destroy and free LP. */
1141 lwp_free (struct lwp_info
*lp
)
1143 xfree (lp
->arch_private
);
1147 /* Remove all LWPs belong to PID from the lwp list. */
1150 purge_lwp_list (int pid
)
1152 struct lwp_info
*lp
, *lpprev
, *lpnext
;
1156 for (lp
= lwp_list
; lp
; lp
= lpnext
)
1160 if (ptid_get_pid (lp
->ptid
) == pid
)
1163 lwp_list
= lp
->next
;
1165 lpprev
->next
= lp
->next
;
1174 /* Add the LWP specified by PID to the list. Return a pointer to the
1175 structure describing the new LWP. The LWP should already be stopped
1176 (with an exception for the very first LWP). */
1178 static struct lwp_info
*
1179 add_lwp (ptid_t ptid
)
1181 struct lwp_info
*lp
;
1183 gdb_assert (is_lwp (ptid
));
1185 lp
= (struct lwp_info
*) xmalloc (sizeof (struct lwp_info
));
1187 memset (lp
, 0, sizeof (struct lwp_info
));
1189 lp
->last_resume_kind
= resume_continue
;
1190 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
1195 lp
->next
= lwp_list
;
1198 /* Let the arch specific bits know about this new thread. Current
1199 clients of this callback take the opportunity to install
1200 watchpoints in the new thread. Don't do this for the first
1201 thread though. If we're spawning a child ("run"), the thread
1202 executes the shell wrapper first, and we shouldn't touch it until
1203 it execs the program we want to debug. For "attach", it'd be
1204 okay to call the callback, but it's not necessary, because
1205 watchpoints can't yet have been inserted into the inferior. */
1206 if (num_lwps (GET_PID (ptid
)) > 1 && linux_nat_new_thread
!= NULL
)
1207 linux_nat_new_thread (lp
);
1212 /* Remove the LWP specified by PID from the list. */
1215 delete_lwp (ptid_t ptid
)
1217 struct lwp_info
*lp
, *lpprev
;
1221 for (lp
= lwp_list
; lp
; lpprev
= lp
, lp
= lp
->next
)
1222 if (ptid_equal (lp
->ptid
, ptid
))
1229 lpprev
->next
= lp
->next
;
1231 lwp_list
= lp
->next
;
1236 /* Return a pointer to the structure describing the LWP corresponding
1237 to PID. If no corresponding LWP could be found, return NULL. */
1239 static struct lwp_info
*
1240 find_lwp_pid (ptid_t ptid
)
1242 struct lwp_info
*lp
;
1246 lwp
= GET_LWP (ptid
);
1248 lwp
= GET_PID (ptid
);
1250 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
1251 if (lwp
== GET_LWP (lp
->ptid
))
1257 /* Call CALLBACK with its second argument set to DATA for every LWP in
1258 the list. If CALLBACK returns 1 for a particular LWP, return a
1259 pointer to the structure describing that LWP immediately.
1260 Otherwise return NULL. */
1263 iterate_over_lwps (ptid_t filter
,
1264 int (*callback
) (struct lwp_info
*, void *),
1267 struct lwp_info
*lp
, *lpnext
;
1269 for (lp
= lwp_list
; lp
; lp
= lpnext
)
1273 if (ptid_match (lp
->ptid
, filter
))
1275 if ((*callback
) (lp
, data
))
1283 /* Iterate like iterate_over_lwps does except when forking-off a child call
1284 CALLBACK with CALLBACK_DATA specifically only for that new child PID. */
1287 linux_nat_iterate_watchpoint_lwps
1288 (linux_nat_iterate_watchpoint_lwps_ftype callback
, void *callback_data
)
1290 int inferior_pid
= ptid_get_pid (inferior_ptid
);
1291 struct inferior
*inf
= current_inferior ();
1293 if (inf
->pid
== inferior_pid
)
1295 /* Iterate all the threads of the current inferior. Without specifying
1296 INFERIOR_PID it would iterate all threads of all inferiors, which is
1297 inappropriate for watchpoints. */
1299 iterate_over_lwps (pid_to_ptid (inferior_pid
), callback
, callback_data
);
1303 /* Detaching a new child PID temporarily present in INFERIOR_PID. */
1305 struct lwp_info
*child_lp
;
1306 struct cleanup
*old_chain
;
1307 pid_t child_pid
= GET_PID (inferior_ptid
);
1308 ptid_t child_ptid
= ptid_build (child_pid
, child_pid
, 0);
1310 gdb_assert (!is_lwp (inferior_ptid
));
1311 gdb_assert (find_lwp_pid (child_ptid
) == NULL
);
1312 child_lp
= add_lwp (child_ptid
);
1313 child_lp
->stopped
= 1;
1314 child_lp
->last_resume_kind
= resume_stop
;
1315 old_chain
= make_cleanup (delete_lwp_cleanup
, child_lp
);
1317 callback (child_lp
, callback_data
);
1319 do_cleanups (old_chain
);
1323 /* Update our internal state when changing from one checkpoint to
1324 another indicated by NEW_PTID. We can only switch single-threaded
1325 applications, so we only create one new LWP, and the previous list
1329 linux_nat_switch_fork (ptid_t new_ptid
)
1331 struct lwp_info
*lp
;
1333 purge_lwp_list (GET_PID (inferior_ptid
));
1335 lp
= add_lwp (new_ptid
);
1338 /* This changes the thread's ptid while preserving the gdb thread
1339 num. Also changes the inferior pid, while preserving the
1341 thread_change_ptid (inferior_ptid
, new_ptid
);
1343 /* We've just told GDB core that the thread changed target id, but,
1344 in fact, it really is a different thread, with different register
1346 registers_changed ();
1349 /* Handle the exit of a single thread LP. */
1352 exit_lwp (struct lwp_info
*lp
)
1354 struct thread_info
*th
= find_thread_ptid (lp
->ptid
);
1358 if (print_thread_events
)
1359 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp
->ptid
));
1361 delete_thread (lp
->ptid
);
1364 delete_lwp (lp
->ptid
);
1367 /* Wait for the LWP specified by LP, which we have just attached to.
1368 Returns a wait status for that LWP, to cache. */
1371 linux_nat_post_attach_wait (ptid_t ptid
, int first
, int *cloned
,
1374 pid_t new_pid
, pid
= GET_LWP (ptid
);
1377 if (linux_proc_pid_is_stopped (pid
))
1379 if (debug_linux_nat
)
1380 fprintf_unfiltered (gdb_stdlog
,
1381 "LNPAW: Attaching to a stopped process\n");
1383 /* The process is definitely stopped. It is in a job control
1384 stop, unless the kernel predates the TASK_STOPPED /
1385 TASK_TRACED distinction, in which case it might be in a
1386 ptrace stop. Make sure it is in a ptrace stop; from there we
1387 can kill it, signal it, et cetera.
1389 First make sure there is a pending SIGSTOP. Since we are
1390 already attached, the process can not transition from stopped
1391 to running without a PTRACE_CONT; so we know this signal will
1392 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1393 probably already in the queue (unless this kernel is old
1394 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1395 is not an RT signal, it can only be queued once. */
1396 kill_lwp (pid
, SIGSTOP
);
1398 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1399 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1400 ptrace (PTRACE_CONT
, pid
, 0, 0);
1403 /* Make sure the initial process is stopped. The user-level threads
1404 layer might want to poke around in the inferior, and that won't
1405 work if things haven't stabilized yet. */
1406 new_pid
= my_waitpid (pid
, &status
, 0);
1407 if (new_pid
== -1 && errno
== ECHILD
)
1410 warning (_("%s is a cloned process"), target_pid_to_str (ptid
));
1412 /* Try again with __WCLONE to check cloned processes. */
1413 new_pid
= my_waitpid (pid
, &status
, __WCLONE
);
1417 gdb_assert (pid
== new_pid
);
1419 if (!WIFSTOPPED (status
))
1421 /* The pid we tried to attach has apparently just exited. */
1422 if (debug_linux_nat
)
1423 fprintf_unfiltered (gdb_stdlog
, "LNPAW: Failed to stop %d: %s",
1424 pid
, status_to_str (status
));
1428 if (WSTOPSIG (status
) != SIGSTOP
)
1431 if (debug_linux_nat
)
1432 fprintf_unfiltered (gdb_stdlog
,
1433 "LNPAW: Received %s after attaching\n",
1434 status_to_str (status
));
1440 /* Attach to the LWP specified by PID. Return 0 if successful, -1 if
1441 the new LWP could not be attached, or 1 if we're already auto
1442 attached to this thread, but haven't processed the
1443 PTRACE_EVENT_CLONE event of its parent thread, so we just ignore
1444 its existance, without considering it an error. */
1447 lin_lwp_attach_lwp (ptid_t ptid
)
1449 struct lwp_info
*lp
;
1453 gdb_assert (is_lwp (ptid
));
1455 block_child_signals (&prev_mask
);
1457 lp
= find_lwp_pid (ptid
);
1458 lwpid
= GET_LWP (ptid
);
1460 /* We assume that we're already attached to any LWP that has an id
1461 equal to the overall process id, and to any LWP that is already
1462 in our list of LWPs. If we're not seeing exit events from threads
1463 and we've had PID wraparound since we last tried to stop all threads,
1464 this assumption might be wrong; fortunately, this is very unlikely
1466 if (lwpid
!= GET_PID (ptid
) && lp
== NULL
)
1468 int status
, cloned
= 0, signalled
= 0;
1470 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) < 0)
1472 if (linux_supports_tracefork_flag
)
1474 /* If we haven't stopped all threads when we get here,
1475 we may have seen a thread listed in thread_db's list,
1476 but not processed the PTRACE_EVENT_CLONE yet. If
1477 that's the case, ignore this new thread, and let
1478 normal event handling discover it later. */
1479 if (in_pid_list_p (stopped_pids
, lwpid
))
1481 /* We've already seen this thread stop, but we
1482 haven't seen the PTRACE_EVENT_CLONE extended
1484 restore_child_signals_mask (&prev_mask
);
1492 /* See if we've got a stop for this new child
1493 pending. If so, we're already attached. */
1494 new_pid
= my_waitpid (lwpid
, &status
, WNOHANG
);
1495 if (new_pid
== -1 && errno
== ECHILD
)
1496 new_pid
= my_waitpid (lwpid
, &status
, __WCLONE
| WNOHANG
);
1499 if (WIFSTOPPED (status
))
1500 add_to_pid_list (&stopped_pids
, lwpid
, status
);
1502 restore_child_signals_mask (&prev_mask
);
1508 /* If we fail to attach to the thread, issue a warning,
1509 but continue. One way this can happen is if thread
1510 creation is interrupted; as of Linux kernel 2.6.19, a
1511 bug may place threads in the thread list and then fail
1513 warning (_("Can't attach %s: %s"), target_pid_to_str (ptid
),
1514 safe_strerror (errno
));
1515 restore_child_signals_mask (&prev_mask
);
1519 if (debug_linux_nat
)
1520 fprintf_unfiltered (gdb_stdlog
,
1521 "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
1522 target_pid_to_str (ptid
));
1524 status
= linux_nat_post_attach_wait (ptid
, 0, &cloned
, &signalled
);
1525 if (!WIFSTOPPED (status
))
1527 restore_child_signals_mask (&prev_mask
);
1531 lp
= add_lwp (ptid
);
1533 lp
->cloned
= cloned
;
1534 lp
->signalled
= signalled
;
1535 if (WSTOPSIG (status
) != SIGSTOP
)
1538 lp
->status
= status
;
1541 target_post_attach (GET_LWP (lp
->ptid
));
1543 if (debug_linux_nat
)
1545 fprintf_unfiltered (gdb_stdlog
,
1546 "LLAL: waitpid %s received %s\n",
1547 target_pid_to_str (ptid
),
1548 status_to_str (status
));
1553 /* We assume that the LWP representing the original process is
1554 already stopped. Mark it as stopped in the data structure
1555 that the GNU/linux ptrace layer uses to keep track of
1556 threads. Note that this won't have already been done since
1557 the main thread will have, we assume, been stopped by an
1558 attach from a different layer. */
1560 lp
= add_lwp (ptid
);
1564 lp
->last_resume_kind
= resume_stop
;
1565 restore_child_signals_mask (&prev_mask
);
1570 linux_nat_create_inferior (struct target_ops
*ops
,
1571 char *exec_file
, char *allargs
, char **env
,
1574 #ifdef HAVE_PERSONALITY
1575 int personality_orig
= 0, personality_set
= 0;
1576 #endif /* HAVE_PERSONALITY */
1578 /* The fork_child mechanism is synchronous and calls target_wait, so
1579 we have to mask the async mode. */
1581 #ifdef HAVE_PERSONALITY
1582 if (disable_randomization
)
1585 personality_orig
= personality (0xffffffff);
1586 if (errno
== 0 && !(personality_orig
& ADDR_NO_RANDOMIZE
))
1588 personality_set
= 1;
1589 personality (personality_orig
| ADDR_NO_RANDOMIZE
);
1591 if (errno
!= 0 || (personality_set
1592 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE
)))
1593 warning (_("Error disabling address space randomization: %s"),
1594 safe_strerror (errno
));
1596 #endif /* HAVE_PERSONALITY */
1598 /* Make sure we report all signals during startup. */
1599 linux_nat_pass_signals (0, NULL
);
1601 linux_ops
->to_create_inferior (ops
, exec_file
, allargs
, env
, from_tty
);
1603 #ifdef HAVE_PERSONALITY
1604 if (personality_set
)
1607 personality (personality_orig
);
1609 warning (_("Error restoring address space randomization: %s"),
1610 safe_strerror (errno
));
1612 #endif /* HAVE_PERSONALITY */
1616 linux_nat_attach (struct target_ops
*ops
, char *args
, int from_tty
)
1618 struct lwp_info
*lp
;
1621 volatile struct gdb_exception ex
;
1623 /* Make sure we report all signals during attach. */
1624 linux_nat_pass_signals (0, NULL
);
1626 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
1628 linux_ops
->to_attach (ops
, args
, from_tty
);
1632 pid_t pid
= parse_pid_to_attach (args
);
1633 struct buffer buffer
;
1634 char *message
, *buffer_s
;
1636 message
= xstrdup (ex
.message
);
1637 make_cleanup (xfree
, message
);
1639 buffer_init (&buffer
);
1640 linux_ptrace_attach_warnings (pid
, &buffer
);
1642 buffer_grow_str0 (&buffer
, "");
1643 buffer_s
= buffer_finish (&buffer
);
1644 make_cleanup (xfree
, buffer_s
);
1646 throw_error (ex
.error
, "%s%s", buffer_s
, message
);
1649 /* The ptrace base target adds the main thread with (pid,0,0)
1650 format. Decorate it with lwp info. */
1651 ptid
= BUILD_LWP (GET_PID (inferior_ptid
), GET_PID (inferior_ptid
));
1652 thread_change_ptid (inferior_ptid
, ptid
);
1654 /* Add the initial process as the first LWP to the list. */
1655 lp
= add_lwp (ptid
);
1657 status
= linux_nat_post_attach_wait (lp
->ptid
, 1, &lp
->cloned
,
1659 if (!WIFSTOPPED (status
))
1661 if (WIFEXITED (status
))
1663 int exit_code
= WEXITSTATUS (status
);
1665 target_terminal_ours ();
1666 target_mourn_inferior ();
1668 error (_("Unable to attach: program exited normally."));
1670 error (_("Unable to attach: program exited with code %d."),
1673 else if (WIFSIGNALED (status
))
1675 enum gdb_signal signo
;
1677 target_terminal_ours ();
1678 target_mourn_inferior ();
1680 signo
= gdb_signal_from_host (WTERMSIG (status
));
1681 error (_("Unable to attach: program terminated with signal "
1683 gdb_signal_to_name (signo
),
1684 gdb_signal_to_string (signo
));
1687 internal_error (__FILE__
, __LINE__
,
1688 _("unexpected status %d for PID %ld"),
1689 status
, (long) GET_LWP (ptid
));
1694 /* Save the wait status to report later. */
1696 if (debug_linux_nat
)
1697 fprintf_unfiltered (gdb_stdlog
,
1698 "LNA: waitpid %ld, saving status %s\n",
1699 (long) GET_PID (lp
->ptid
), status_to_str (status
));
1701 lp
->status
= status
;
1703 if (target_can_async_p ())
1704 target_async (inferior_event_handler
, 0);
1707 /* Get pending status of LP. */
1709 get_pending_status (struct lwp_info
*lp
, int *status
)
1711 enum gdb_signal signo
= GDB_SIGNAL_0
;
1713 /* If we paused threads momentarily, we may have stored pending
1714 events in lp->status or lp->waitstatus (see stop_wait_callback),
1715 and GDB core hasn't seen any signal for those threads.
1716 Otherwise, the last signal reported to the core is found in the
1717 thread object's stop_signal.
1719 There's a corner case that isn't handled here at present. Only
1720 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1721 stop_signal make sense as a real signal to pass to the inferior.
1722 Some catchpoint related events, like
1723 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1724 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1725 those traps are debug API (ptrace in our case) related and
1726 induced; the inferior wouldn't see them if it wasn't being
1727 traced. Hence, we should never pass them to the inferior, even
1728 when set to pass state. Since this corner case isn't handled by
1729 infrun.c when proceeding with a signal, for consistency, neither
1730 do we handle it here (or elsewhere in the file we check for
1731 signal pass state). Normally SIGTRAP isn't set to pass state, so
1732 this is really a corner case. */
1734 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
1735 signo
= GDB_SIGNAL_0
; /* a pending ptrace event, not a real signal. */
1736 else if (lp
->status
)
1737 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1738 else if (non_stop
&& !is_executing (lp
->ptid
))
1740 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1742 signo
= tp
->suspend
.stop_signal
;
1746 struct target_waitstatus last
;
1749 get_last_target_status (&last_ptid
, &last
);
1751 if (GET_LWP (lp
->ptid
) == GET_LWP (last_ptid
))
1753 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1755 signo
= tp
->suspend
.stop_signal
;
1761 if (signo
== GDB_SIGNAL_0
)
1763 if (debug_linux_nat
)
1764 fprintf_unfiltered (gdb_stdlog
,
1765 "GPT: lwp %s has no pending signal\n",
1766 target_pid_to_str (lp
->ptid
));
1768 else if (!signal_pass_state (signo
))
1770 if (debug_linux_nat
)
1771 fprintf_unfiltered (gdb_stdlog
,
1772 "GPT: lwp %s had signal %s, "
1773 "but it is in no pass state\n",
1774 target_pid_to_str (lp
->ptid
),
1775 gdb_signal_to_string (signo
));
1779 *status
= W_STOPCODE (gdb_signal_to_host (signo
));
1781 if (debug_linux_nat
)
1782 fprintf_unfiltered (gdb_stdlog
,
1783 "GPT: lwp %s has pending signal %s\n",
1784 target_pid_to_str (lp
->ptid
),
1785 gdb_signal_to_string (signo
));
1792 detach_callback (struct lwp_info
*lp
, void *data
)
1794 gdb_assert (lp
->status
== 0 || WIFSTOPPED (lp
->status
));
1796 if (debug_linux_nat
&& lp
->status
)
1797 fprintf_unfiltered (gdb_stdlog
, "DC: Pending %s for %s on detach.\n",
1798 strsignal (WSTOPSIG (lp
->status
)),
1799 target_pid_to_str (lp
->ptid
));
1801 /* If there is a pending SIGSTOP, get rid of it. */
1804 if (debug_linux_nat
)
1805 fprintf_unfiltered (gdb_stdlog
,
1806 "DC: Sending SIGCONT to %s\n",
1807 target_pid_to_str (lp
->ptid
));
1809 kill_lwp (GET_LWP (lp
->ptid
), SIGCONT
);
1813 /* We don't actually detach from the LWP that has an id equal to the
1814 overall process id just yet. */
1815 if (GET_LWP (lp
->ptid
) != GET_PID (lp
->ptid
))
1819 /* Pass on any pending signal for this LWP. */
1820 get_pending_status (lp
, &status
);
1822 if (linux_nat_prepare_to_resume
!= NULL
)
1823 linux_nat_prepare_to_resume (lp
);
1825 if (ptrace (PTRACE_DETACH
, GET_LWP (lp
->ptid
), 0,
1826 WSTOPSIG (status
)) < 0)
1827 error (_("Can't detach %s: %s"), target_pid_to_str (lp
->ptid
),
1828 safe_strerror (errno
));
1830 if (debug_linux_nat
)
1831 fprintf_unfiltered (gdb_stdlog
,
1832 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1833 target_pid_to_str (lp
->ptid
),
1834 strsignal (WSTOPSIG (status
)));
1836 delete_lwp (lp
->ptid
);
1843 linux_nat_detach (struct target_ops
*ops
, char *args
, int from_tty
)
1847 struct lwp_info
*main_lwp
;
1849 pid
= GET_PID (inferior_ptid
);
1851 if (target_can_async_p ())
1852 linux_nat_async (NULL
, 0);
1854 /* Stop all threads before detaching. ptrace requires that the
1855 thread is stopped to sucessfully detach. */
1856 iterate_over_lwps (pid_to_ptid (pid
), stop_callback
, NULL
);
1857 /* ... and wait until all of them have reported back that
1858 they're no longer running. */
1859 iterate_over_lwps (pid_to_ptid (pid
), stop_wait_callback
, NULL
);
1861 iterate_over_lwps (pid_to_ptid (pid
), detach_callback
, NULL
);
1863 /* Only the initial process should be left right now. */
1864 gdb_assert (num_lwps (GET_PID (inferior_ptid
)) == 1);
1866 main_lwp
= find_lwp_pid (pid_to_ptid (pid
));
1868 /* Pass on any pending signal for the last LWP. */
1869 if ((args
== NULL
|| *args
== '\0')
1870 && get_pending_status (main_lwp
, &status
) != -1
1871 && WIFSTOPPED (status
))
1873 /* Put the signal number in ARGS so that inf_ptrace_detach will
1874 pass it along with PTRACE_DETACH. */
1876 sprintf (args
, "%d", (int) WSTOPSIG (status
));
1877 if (debug_linux_nat
)
1878 fprintf_unfiltered (gdb_stdlog
,
1879 "LND: Sending signal %s to %s\n",
1881 target_pid_to_str (main_lwp
->ptid
));
1884 if (linux_nat_prepare_to_resume
!= NULL
)
1885 linux_nat_prepare_to_resume (main_lwp
);
1886 delete_lwp (main_lwp
->ptid
);
1888 if (forks_exist_p ())
1890 /* Multi-fork case. The current inferior_ptid is being detached
1891 from, but there are other viable forks to debug. Detach from
1892 the current fork, and context-switch to the first
1894 linux_fork_detach (args
, from_tty
);
1896 if (non_stop
&& target_can_async_p ())
1897 target_async (inferior_event_handler
, 0);
1900 linux_ops
->to_detach (ops
, args
, from_tty
);
1906 resume_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1910 struct inferior
*inf
= find_inferior_pid (GET_PID (lp
->ptid
));
1912 if (inf
->vfork_child
!= NULL
)
1914 if (debug_linux_nat
)
1915 fprintf_unfiltered (gdb_stdlog
,
1916 "RC: Not resuming %s (vfork parent)\n",
1917 target_pid_to_str (lp
->ptid
));
1919 else if (lp
->status
== 0
1920 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
1922 if (debug_linux_nat
)
1923 fprintf_unfiltered (gdb_stdlog
,
1924 "RC: Resuming sibling %s, %s, %s\n",
1925 target_pid_to_str (lp
->ptid
),
1926 (signo
!= GDB_SIGNAL_0
1927 ? strsignal (gdb_signal_to_host (signo
))
1929 step
? "step" : "resume");
1931 if (linux_nat_prepare_to_resume
!= NULL
)
1932 linux_nat_prepare_to_resume (lp
);
1933 linux_ops
->to_resume (linux_ops
,
1934 pid_to_ptid (GET_LWP (lp
->ptid
)),
1938 lp
->stopped_by_watchpoint
= 0;
1942 if (debug_linux_nat
)
1943 fprintf_unfiltered (gdb_stdlog
,
1944 "RC: Not resuming sibling %s (has pending)\n",
1945 target_pid_to_str (lp
->ptid
));
1950 if (debug_linux_nat
)
1951 fprintf_unfiltered (gdb_stdlog
,
1952 "RC: Not resuming sibling %s (not stopped)\n",
1953 target_pid_to_str (lp
->ptid
));
1957 /* Resume LWP, with the last stop signal, if it is in pass state. */
1960 linux_nat_resume_callback (struct lwp_info
*lp
, void *data
)
1962 enum gdb_signal signo
= GDB_SIGNAL_0
;
1966 struct thread_info
*thread
;
1968 thread
= find_thread_ptid (lp
->ptid
);
1971 if (signal_pass_state (thread
->suspend
.stop_signal
))
1972 signo
= thread
->suspend
.stop_signal
;
1973 thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
1977 resume_lwp (lp
, 0, signo
);
1982 resume_clear_callback (struct lwp_info
*lp
, void *data
)
1985 lp
->last_resume_kind
= resume_stop
;
1990 resume_set_callback (struct lwp_info
*lp
, void *data
)
1993 lp
->last_resume_kind
= resume_continue
;
1998 linux_nat_resume (struct target_ops
*ops
,
1999 ptid_t ptid
, int step
, enum gdb_signal signo
)
2002 struct lwp_info
*lp
;
2005 if (debug_linux_nat
)
2006 fprintf_unfiltered (gdb_stdlog
,
2007 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
2008 step
? "step" : "resume",
2009 target_pid_to_str (ptid
),
2010 (signo
!= GDB_SIGNAL_0
2011 ? strsignal (gdb_signal_to_host (signo
)) : "0"),
2012 target_pid_to_str (inferior_ptid
));
2014 block_child_signals (&prev_mask
);
2016 /* A specific PTID means `step only this process id'. */
2017 resume_many
= (ptid_equal (minus_one_ptid
, ptid
)
2018 || ptid_is_pid (ptid
));
2020 /* Mark the lwps we're resuming as resumed. */
2021 iterate_over_lwps (ptid
, resume_set_callback
, NULL
);
2023 /* See if it's the current inferior that should be handled
2026 lp
= find_lwp_pid (inferior_ptid
);
2028 lp
= find_lwp_pid (ptid
);
2029 gdb_assert (lp
!= NULL
);
2031 /* Remember if we're stepping. */
2033 lp
->last_resume_kind
= step
? resume_step
: resume_continue
;
2035 /* If we have a pending wait status for this thread, there is no
2036 point in resuming the process. But first make sure that
2037 linux_nat_wait won't preemptively handle the event - we
2038 should never take this short-circuit if we are going to
2039 leave LP running, since we have skipped resuming all the
2040 other threads. This bit of code needs to be synchronized
2041 with linux_nat_wait. */
2043 if (lp
->status
&& WIFSTOPPED (lp
->status
))
2046 && WSTOPSIG (lp
->status
)
2047 && sigismember (&pass_mask
, WSTOPSIG (lp
->status
)))
2049 if (debug_linux_nat
)
2050 fprintf_unfiltered (gdb_stdlog
,
2051 "LLR: Not short circuiting for ignored "
2052 "status 0x%x\n", lp
->status
);
2054 /* FIXME: What should we do if we are supposed to continue
2055 this thread with a signal? */
2056 gdb_assert (signo
== GDB_SIGNAL_0
);
2057 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
2062 if (lp
->status
|| lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
2064 /* FIXME: What should we do if we are supposed to continue
2065 this thread with a signal? */
2066 gdb_assert (signo
== GDB_SIGNAL_0
);
2068 if (debug_linux_nat
)
2069 fprintf_unfiltered (gdb_stdlog
,
2070 "LLR: Short circuiting for status 0x%x\n",
2073 restore_child_signals_mask (&prev_mask
);
2074 if (target_can_async_p ())
2076 target_async (inferior_event_handler
, 0);
2077 /* Tell the event loop we have something to process. */
2083 /* Mark LWP as not stopped to prevent it from being continued by
2084 linux_nat_resume_callback. */
2088 iterate_over_lwps (ptid
, linux_nat_resume_callback
, NULL
);
2090 /* Convert to something the lower layer understands. */
2091 ptid
= pid_to_ptid (GET_LWP (lp
->ptid
));
2093 if (linux_nat_prepare_to_resume
!= NULL
)
2094 linux_nat_prepare_to_resume (lp
);
2095 linux_ops
->to_resume (linux_ops
, ptid
, step
, signo
);
2096 lp
->stopped_by_watchpoint
= 0;
2098 if (debug_linux_nat
)
2099 fprintf_unfiltered (gdb_stdlog
,
2100 "LLR: %s %s, %s (resume event thread)\n",
2101 step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2102 target_pid_to_str (ptid
),
2103 (signo
!= GDB_SIGNAL_0
2104 ? strsignal (gdb_signal_to_host (signo
)) : "0"));
2106 restore_child_signals_mask (&prev_mask
);
2107 if (target_can_async_p ())
2108 target_async (inferior_event_handler
, 0);
2111 /* Send a signal to an LWP. */
2114 kill_lwp (int lwpid
, int signo
)
2116 /* Use tkill, if possible, in case we are using nptl threads. If tkill
2117 fails, then we are not using nptl threads and we should be using kill. */
2119 #ifdef HAVE_TKILL_SYSCALL
2121 static int tkill_failed
;
2128 ret
= syscall (__NR_tkill
, lwpid
, signo
);
2129 if (errno
!= ENOSYS
)
2136 return kill (lwpid
, signo
);
2139 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
2140 event, check if the core is interested in it: if not, ignore the
2141 event, and keep waiting; otherwise, we need to toggle the LWP's
2142 syscall entry/exit status, since the ptrace event itself doesn't
2143 indicate it, and report the trap to higher layers. */
2146 linux_handle_syscall_trap (struct lwp_info
*lp
, int stopping
)
2148 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
2149 struct gdbarch
*gdbarch
= target_thread_architecture (lp
->ptid
);
2150 int syscall_number
= (int) gdbarch_get_syscall_number (gdbarch
, lp
->ptid
);
2154 /* If we're stopping threads, there's a SIGSTOP pending, which
2155 makes it so that the LWP reports an immediate syscall return,
2156 followed by the SIGSTOP. Skip seeing that "return" using
2157 PTRACE_CONT directly, and let stop_wait_callback collect the
2158 SIGSTOP. Later when the thread is resumed, a new syscall
2159 entry event. If we didn't do this (and returned 0), we'd
2160 leave a syscall entry pending, and our caller, by using
2161 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
2162 itself. Later, when the user re-resumes this LWP, we'd see
2163 another syscall entry event and we'd mistake it for a return.
2165 If stop_wait_callback didn't force the SIGSTOP out of the LWP
2166 (leaving immediately with LWP->signalled set, without issuing
2167 a PTRACE_CONT), it would still be problematic to leave this
2168 syscall enter pending, as later when the thread is resumed,
2169 it would then see the same syscall exit mentioned above,
2170 followed by the delayed SIGSTOP, while the syscall didn't
2171 actually get to execute. It seems it would be even more
2172 confusing to the user. */
2174 if (debug_linux_nat
)
2175 fprintf_unfiltered (gdb_stdlog
,
2176 "LHST: ignoring syscall %d "
2177 "for LWP %ld (stopping threads), "
2178 "resuming with PTRACE_CONT for SIGSTOP\n",
2180 GET_LWP (lp
->ptid
));
2182 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2183 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2187 if (catch_syscall_enabled ())
2189 /* Always update the entry/return state, even if this particular
2190 syscall isn't interesting to the core now. In async mode,
2191 the user could install a new catchpoint for this syscall
2192 between syscall enter/return, and we'll need to know to
2193 report a syscall return if that happens. */
2194 lp
->syscall_state
= (lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
2195 ? TARGET_WAITKIND_SYSCALL_RETURN
2196 : TARGET_WAITKIND_SYSCALL_ENTRY
);
2198 if (catching_syscall_number (syscall_number
))
2200 /* Alright, an event to report. */
2201 ourstatus
->kind
= lp
->syscall_state
;
2202 ourstatus
->value
.syscall_number
= syscall_number
;
2204 if (debug_linux_nat
)
2205 fprintf_unfiltered (gdb_stdlog
,
2206 "LHST: stopping for %s of syscall %d"
2209 == TARGET_WAITKIND_SYSCALL_ENTRY
2210 ? "entry" : "return",
2212 GET_LWP (lp
->ptid
));
2216 if (debug_linux_nat
)
2217 fprintf_unfiltered (gdb_stdlog
,
2218 "LHST: ignoring %s of syscall %d "
2220 lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
2221 ? "entry" : "return",
2223 GET_LWP (lp
->ptid
));
2227 /* If we had been syscall tracing, and hence used PT_SYSCALL
2228 before on this LWP, it could happen that the user removes all
2229 syscall catchpoints before we get to process this event.
2230 There are two noteworthy issues here:
2232 - When stopped at a syscall entry event, resuming with
2233 PT_STEP still resumes executing the syscall and reports a
2236 - Only PT_SYSCALL catches syscall enters. If we last
2237 single-stepped this thread, then this event can't be a
2238 syscall enter. If we last single-stepped this thread, this
2239 has to be a syscall exit.
2241 The points above mean that the next resume, be it PT_STEP or
2242 PT_CONTINUE, can not trigger a syscall trace event. */
2243 if (debug_linux_nat
)
2244 fprintf_unfiltered (gdb_stdlog
,
2245 "LHST: caught syscall event "
2246 "with no syscall catchpoints."
2247 " %d for LWP %ld, ignoring\n",
2249 GET_LWP (lp
->ptid
));
2250 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2253 /* The core isn't interested in this event. For efficiency, avoid
2254 stopping all threads only to have the core resume them all again.
2255 Since we're not stopping threads, if we're still syscall tracing
2256 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
2257 subsequent syscall. Simply resume using the inf-ptrace layer,
2258 which knows when to use PT_SYSCALL or PT_CONTINUE. */
2260 /* Note that gdbarch_get_syscall_number may access registers, hence
2262 registers_changed ();
2263 if (linux_nat_prepare_to_resume
!= NULL
)
2264 linux_nat_prepare_to_resume (lp
);
2265 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
2266 lp
->step
, GDB_SIGNAL_0
);
2270 /* Handle a GNU/Linux extended wait response. If we see a clone
2271 event, we need to add the new LWP to our list (and not report the
2272 trap to higher layers). This function returns non-zero if the
2273 event should be ignored and we should wait again. If STOPPING is
2274 true, the new LWP remains stopped, otherwise it is continued. */
2277 linux_handle_extended_wait (struct lwp_info
*lp
, int status
,
2280 int pid
= GET_LWP (lp
->ptid
);
2281 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
2282 int event
= status
>> 16;
2284 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
2285 || event
== PTRACE_EVENT_CLONE
)
2287 unsigned long new_pid
;
2290 ptrace (PTRACE_GETEVENTMSG
, pid
, 0, &new_pid
);
2292 /* If we haven't already seen the new PID stop, wait for it now. */
2293 if (! pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
2295 /* The new child has a pending SIGSTOP. We can't affect it until it
2296 hits the SIGSTOP, but we're already attached. */
2297 ret
= my_waitpid (new_pid
, &status
,
2298 (event
== PTRACE_EVENT_CLONE
) ? __WCLONE
: 0);
2300 perror_with_name (_("waiting for new child"));
2301 else if (ret
!= new_pid
)
2302 internal_error (__FILE__
, __LINE__
,
2303 _("wait returned unexpected PID %d"), ret
);
2304 else if (!WIFSTOPPED (status
))
2305 internal_error (__FILE__
, __LINE__
,
2306 _("wait returned unexpected status 0x%x"), status
);
2309 ourstatus
->value
.related_pid
= ptid_build (new_pid
, new_pid
, 0);
2311 if (event
== PTRACE_EVENT_FORK
2312 && linux_fork_checkpointing_p (GET_PID (lp
->ptid
)))
2314 /* Handle checkpointing by linux-fork.c here as a special
2315 case. We don't want the follow-fork-mode or 'catch fork'
2316 to interfere with this. */
2318 /* This won't actually modify the breakpoint list, but will
2319 physically remove the breakpoints from the child. */
2320 detach_breakpoints (new_pid
);
2322 /* Retain child fork in ptrace (stopped) state. */
2323 if (!find_fork_pid (new_pid
))
2326 /* Report as spurious, so that infrun doesn't want to follow
2327 this fork. We're actually doing an infcall in
2329 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
2330 linux_enable_event_reporting (pid_to_ptid (new_pid
));
2332 /* Report the stop to the core. */
2336 if (event
== PTRACE_EVENT_FORK
)
2337 ourstatus
->kind
= TARGET_WAITKIND_FORKED
;
2338 else if (event
== PTRACE_EVENT_VFORK
)
2339 ourstatus
->kind
= TARGET_WAITKIND_VFORKED
;
2342 struct lwp_info
*new_lp
;
2344 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2346 if (debug_linux_nat
)
2347 fprintf_unfiltered (gdb_stdlog
,
2348 "LHEW: Got clone event "
2349 "from LWP %d, new child is LWP %ld\n",
2352 new_lp
= add_lwp (BUILD_LWP (new_pid
, GET_PID (lp
->ptid
)));
2354 new_lp
->stopped
= 1;
2356 if (WSTOPSIG (status
) != SIGSTOP
)
2358 /* This can happen if someone starts sending signals to
2359 the new thread before it gets a chance to run, which
2360 have a lower number than SIGSTOP (e.g. SIGUSR1).
2361 This is an unlikely case, and harder to handle for
2362 fork / vfork than for clone, so we do not try - but
2363 we handle it for clone events here. We'll send
2364 the other signal on to the thread below. */
2366 new_lp
->signalled
= 1;
2370 struct thread_info
*tp
;
2372 /* When we stop for an event in some other thread, and
2373 pull the thread list just as this thread has cloned,
2374 we'll have seen the new thread in the thread_db list
2375 before handling the CLONE event (glibc's
2376 pthread_create adds the new thread to the thread list
2377 before clone'ing, and has the kernel fill in the
2378 thread's tid on the clone call with
2379 CLONE_PARENT_SETTID). If that happened, and the core
2380 had requested the new thread to stop, we'll have
2381 killed it with SIGSTOP. But since SIGSTOP is not an
2382 RT signal, it can only be queued once. We need to be
2383 careful to not resume the LWP if we wanted it to
2384 stop. In that case, we'll leave the SIGSTOP pending.
2385 It will later be reported as GDB_SIGNAL_0. */
2386 tp
= find_thread_ptid (new_lp
->ptid
);
2387 if (tp
!= NULL
&& tp
->stop_requested
)
2388 new_lp
->last_resume_kind
= resume_stop
;
2395 /* Add the new thread to GDB's lists as soon as possible
2398 1) the frontend doesn't have to wait for a stop to
2401 2) we tag it with the correct running state. */
2403 /* If the thread_db layer is active, let it know about
2404 this new thread, and add it to GDB's list. */
2405 if (!thread_db_attach_lwp (new_lp
->ptid
))
2407 /* We're not using thread_db. Add it to GDB's
2409 target_post_attach (GET_LWP (new_lp
->ptid
));
2410 add_thread (new_lp
->ptid
);
2415 set_running (new_lp
->ptid
, 1);
2416 set_executing (new_lp
->ptid
, 1);
2417 /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced
2419 new_lp
->last_resume_kind
= resume_continue
;
2425 /* We created NEW_LP so it cannot yet contain STATUS. */
2426 gdb_assert (new_lp
->status
== 0);
2428 /* Save the wait status to report later. */
2429 if (debug_linux_nat
)
2430 fprintf_unfiltered (gdb_stdlog
,
2431 "LHEW: waitpid of new LWP %ld, "
2432 "saving status %s\n",
2433 (long) GET_LWP (new_lp
->ptid
),
2434 status_to_str (status
));
2435 new_lp
->status
= status
;
2438 /* Note the need to use the low target ops to resume, to
2439 handle resuming with PT_SYSCALL if we have syscall
2443 new_lp
->resumed
= 1;
2447 gdb_assert (new_lp
->last_resume_kind
== resume_continue
);
2448 if (debug_linux_nat
)
2449 fprintf_unfiltered (gdb_stdlog
,
2450 "LHEW: resuming new LWP %ld\n",
2451 GET_LWP (new_lp
->ptid
));
2452 if (linux_nat_prepare_to_resume
!= NULL
)
2453 linux_nat_prepare_to_resume (new_lp
);
2454 linux_ops
->to_resume (linux_ops
, pid_to_ptid (new_pid
),
2456 new_lp
->stopped
= 0;
2460 if (debug_linux_nat
)
2461 fprintf_unfiltered (gdb_stdlog
,
2462 "LHEW: resuming parent LWP %d\n", pid
);
2463 if (linux_nat_prepare_to_resume
!= NULL
)
2464 linux_nat_prepare_to_resume (lp
);
2465 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
2474 if (event
== PTRACE_EVENT_EXEC
)
2476 if (debug_linux_nat
)
2477 fprintf_unfiltered (gdb_stdlog
,
2478 "LHEW: Got exec event from LWP %ld\n",
2479 GET_LWP (lp
->ptid
));
2481 ourstatus
->kind
= TARGET_WAITKIND_EXECD
;
2482 ourstatus
->value
.execd_pathname
2483 = xstrdup (linux_child_pid_to_exec_file (pid
));
2488 if (event
== PTRACE_EVENT_VFORK_DONE
)
2490 if (current_inferior ()->waiting_for_vfork_done
)
2492 if (debug_linux_nat
)
2493 fprintf_unfiltered (gdb_stdlog
,
2494 "LHEW: Got expected PTRACE_EVENT_"
2495 "VFORK_DONE from LWP %ld: stopping\n",
2496 GET_LWP (lp
->ptid
));
2498 ourstatus
->kind
= TARGET_WAITKIND_VFORK_DONE
;
2502 if (debug_linux_nat
)
2503 fprintf_unfiltered (gdb_stdlog
,
2504 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2505 "from LWP %ld: resuming\n",
2506 GET_LWP (lp
->ptid
));
2507 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2511 internal_error (__FILE__
, __LINE__
,
2512 _("unknown ptrace event %d"), event
);
2515 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2519 wait_lwp (struct lwp_info
*lp
)
2523 int thread_dead
= 0;
2526 gdb_assert (!lp
->stopped
);
2527 gdb_assert (lp
->status
== 0);
2529 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2530 block_child_signals (&prev_mask
);
2534 /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind
2535 was right and we should just call sigsuspend. */
2537 pid
= my_waitpid (GET_LWP (lp
->ptid
), &status
, WNOHANG
);
2538 if (pid
== -1 && errno
== ECHILD
)
2539 pid
= my_waitpid (GET_LWP (lp
->ptid
), &status
, __WCLONE
| WNOHANG
);
2540 if (pid
== -1 && errno
== ECHILD
)
2542 /* The thread has previously exited. We need to delete it
2543 now because, for some vendor 2.4 kernels with NPTL
2544 support backported, there won't be an exit event unless
2545 it is the main thread. 2.6 kernels will report an exit
2546 event for each thread that exits, as expected. */
2548 if (debug_linux_nat
)
2549 fprintf_unfiltered (gdb_stdlog
, "WL: %s vanished.\n",
2550 target_pid_to_str (lp
->ptid
));
2555 /* Bugs 10970, 12702.
2556 Thread group leader may have exited in which case we'll lock up in
2557 waitpid if there are other threads, even if they are all zombies too.
2558 Basically, we're not supposed to use waitpid this way.
2559 __WCLONE is not applicable for the leader so we can't use that.
2560 LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED
2561 process; it gets ESRCH both for the zombie and for running processes.
2563 As a workaround, check if we're waiting for the thread group leader and
2564 if it's a zombie, and avoid calling waitpid if it is.
2566 This is racy, what if the tgl becomes a zombie right after we check?
2567 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2568 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2570 if (GET_PID (lp
->ptid
) == GET_LWP (lp
->ptid
)
2571 && linux_proc_pid_is_zombie (GET_LWP (lp
->ptid
)))
2574 if (debug_linux_nat
)
2575 fprintf_unfiltered (gdb_stdlog
,
2576 "WL: Thread group leader %s vanished.\n",
2577 target_pid_to_str (lp
->ptid
));
2581 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2582 get invoked despite our caller had them intentionally blocked by
2583 block_child_signals. This is sensitive only to the loop of
2584 linux_nat_wait_1 and there if we get called my_waitpid gets called
2585 again before it gets to sigsuspend so we can safely let the handlers
2586 get executed here. */
2588 sigsuspend (&suspend_mask
);
2591 restore_child_signals_mask (&prev_mask
);
2595 gdb_assert (pid
== GET_LWP (lp
->ptid
));
2597 if (debug_linux_nat
)
2599 fprintf_unfiltered (gdb_stdlog
,
2600 "WL: waitpid %s received %s\n",
2601 target_pid_to_str (lp
->ptid
),
2602 status_to_str (status
));
2605 /* Check if the thread has exited. */
2606 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2609 if (debug_linux_nat
)
2610 fprintf_unfiltered (gdb_stdlog
, "WL: %s exited.\n",
2611 target_pid_to_str (lp
->ptid
));
2621 gdb_assert (WIFSTOPPED (status
));
2623 /* Handle GNU/Linux's syscall SIGTRAPs. */
2624 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2626 /* No longer need the sysgood bit. The ptrace event ends up
2627 recorded in lp->waitstatus if we care for it. We can carry
2628 on handling the event like a regular SIGTRAP from here
2630 status
= W_STOPCODE (SIGTRAP
);
2631 if (linux_handle_syscall_trap (lp
, 1))
2632 return wait_lwp (lp
);
2635 /* Handle GNU/Linux's extended waitstatus for trace events. */
2636 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 != 0)
2638 if (debug_linux_nat
)
2639 fprintf_unfiltered (gdb_stdlog
,
2640 "WL: Handling extended status 0x%06x\n",
2642 if (linux_handle_extended_wait (lp
, status
, 1))
2643 return wait_lwp (lp
);
2649 /* Send a SIGSTOP to LP. */
2652 stop_callback (struct lwp_info
*lp
, void *data
)
2654 if (!lp
->stopped
&& !lp
->signalled
)
2658 if (debug_linux_nat
)
2660 fprintf_unfiltered (gdb_stdlog
,
2661 "SC: kill %s **<SIGSTOP>**\n",
2662 target_pid_to_str (lp
->ptid
));
2665 ret
= kill_lwp (GET_LWP (lp
->ptid
), SIGSTOP
);
2666 if (debug_linux_nat
)
2668 fprintf_unfiltered (gdb_stdlog
,
2669 "SC: lwp kill %d %s\n",
2671 errno
? safe_strerror (errno
) : "ERRNO-OK");
2675 gdb_assert (lp
->status
== 0);
2681 /* Request a stop on LWP. */
2684 linux_stop_lwp (struct lwp_info
*lwp
)
2686 stop_callback (lwp
, NULL
);
2689 /* Return non-zero if LWP PID has a pending SIGINT. */
2692 linux_nat_has_pending_sigint (int pid
)
2694 sigset_t pending
, blocked
, ignored
;
2696 linux_proc_pending_signals (pid
, &pending
, &blocked
, &ignored
);
2698 if (sigismember (&pending
, SIGINT
)
2699 && !sigismember (&ignored
, SIGINT
))
2705 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2708 set_ignore_sigint (struct lwp_info
*lp
, void *data
)
2710 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2711 flag to consume the next one. */
2712 if (lp
->stopped
&& lp
->status
!= 0 && WIFSTOPPED (lp
->status
)
2713 && WSTOPSIG (lp
->status
) == SIGINT
)
2716 lp
->ignore_sigint
= 1;
2721 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2722 This function is called after we know the LWP has stopped; if the LWP
2723 stopped before the expected SIGINT was delivered, then it will never have
2724 arrived. Also, if the signal was delivered to a shared queue and consumed
2725 by a different thread, it will never be delivered to this LWP. */
2728 maybe_clear_ignore_sigint (struct lwp_info
*lp
)
2730 if (!lp
->ignore_sigint
)
2733 if (!linux_nat_has_pending_sigint (GET_LWP (lp
->ptid
)))
2735 if (debug_linux_nat
)
2736 fprintf_unfiltered (gdb_stdlog
,
2737 "MCIS: Clearing bogus flag for %s\n",
2738 target_pid_to_str (lp
->ptid
));
2739 lp
->ignore_sigint
= 0;
2743 /* Fetch the possible triggered data watchpoint info and store it in
2746 On some archs, like x86, that use debug registers to set
2747 watchpoints, it's possible that the way to know which watched
2748 address trapped, is to check the register that is used to select
2749 which address to watch. Problem is, between setting the watchpoint
2750 and reading back which data address trapped, the user may change
2751 the set of watchpoints, and, as a consequence, GDB changes the
2752 debug registers in the inferior. To avoid reading back a stale
2753 stopped-data-address when that happens, we cache in LP the fact
2754 that a watchpoint trapped, and the corresponding data address, as
2755 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2756 registers meanwhile, we have the cached data we can rely on. */
2759 save_sigtrap (struct lwp_info
*lp
)
2761 struct cleanup
*old_chain
;
2763 if (linux_ops
->to_stopped_by_watchpoint
== NULL
)
2765 lp
->stopped_by_watchpoint
= 0;
2769 old_chain
= save_inferior_ptid ();
2770 inferior_ptid
= lp
->ptid
;
2772 lp
->stopped_by_watchpoint
= linux_ops
->to_stopped_by_watchpoint ();
2774 if (lp
->stopped_by_watchpoint
)
2776 if (linux_ops
->to_stopped_data_address
!= NULL
)
2777 lp
->stopped_data_address_p
=
2778 linux_ops
->to_stopped_data_address (¤t_target
,
2779 &lp
->stopped_data_address
);
2781 lp
->stopped_data_address_p
= 0;
2784 do_cleanups (old_chain
);
2787 /* See save_sigtrap. */
2790 linux_nat_stopped_by_watchpoint (void)
2792 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2794 gdb_assert (lp
!= NULL
);
2796 return lp
->stopped_by_watchpoint
;
2800 linux_nat_stopped_data_address (struct target_ops
*ops
, CORE_ADDR
*addr_p
)
2802 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2804 gdb_assert (lp
!= NULL
);
2806 *addr_p
= lp
->stopped_data_address
;
2808 return lp
->stopped_data_address_p
;
2811 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2814 sigtrap_is_event (int status
)
2816 return WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
;
2819 /* SIGTRAP-like events recognizer. */
2821 static int (*linux_nat_status_is_event
) (int status
) = sigtrap_is_event
;
2823 /* Check for SIGTRAP-like events in LP. */
2826 linux_nat_lp_status_is_event (struct lwp_info
*lp
)
2828 /* We check for lp->waitstatus in addition to lp->status, because we can
2829 have pending process exits recorded in lp->status
2830 and W_EXITCODE(0,0) == 0. We should probably have an additional
2831 lp->status_p flag. */
2833 return (lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
2834 && linux_nat_status_is_event (lp
->status
));
2837 /* Set alternative SIGTRAP-like events recognizer. If
2838 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2842 linux_nat_set_status_is_event (struct target_ops
*t
,
2843 int (*status_is_event
) (int status
))
2845 linux_nat_status_is_event
= status_is_event
;
2848 /* Wait until LP is stopped. */
2851 stop_wait_callback (struct lwp_info
*lp
, void *data
)
2853 struct inferior
*inf
= find_inferior_pid (GET_PID (lp
->ptid
));
2855 /* If this is a vfork parent, bail out, it is not going to report
2856 any SIGSTOP until the vfork is done with. */
2857 if (inf
->vfork_child
!= NULL
)
2864 status
= wait_lwp (lp
);
2868 if (lp
->ignore_sigint
&& WIFSTOPPED (status
)
2869 && WSTOPSIG (status
) == SIGINT
)
2871 lp
->ignore_sigint
= 0;
2874 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2875 if (debug_linux_nat
)
2876 fprintf_unfiltered (gdb_stdlog
,
2877 "PTRACE_CONT %s, 0, 0 (%s) "
2878 "(discarding SIGINT)\n",
2879 target_pid_to_str (lp
->ptid
),
2880 errno
? safe_strerror (errno
) : "OK");
2882 return stop_wait_callback (lp
, NULL
);
2885 maybe_clear_ignore_sigint (lp
);
2887 if (WSTOPSIG (status
) != SIGSTOP
)
2889 /* The thread was stopped with a signal other than SIGSTOP. */
2893 if (debug_linux_nat
)
2894 fprintf_unfiltered (gdb_stdlog
,
2895 "SWC: Pending event %s in %s\n",
2896 status_to_str ((int) status
),
2897 target_pid_to_str (lp
->ptid
));
2899 /* Save the sigtrap event. */
2900 lp
->status
= status
;
2901 gdb_assert (!lp
->stopped
);
2902 gdb_assert (lp
->signalled
);
2907 /* We caught the SIGSTOP that we intended to catch, so
2908 there's no SIGSTOP pending. */
2910 if (debug_linux_nat
)
2911 fprintf_unfiltered (gdb_stdlog
,
2912 "SWC: Delayed SIGSTOP caught for %s.\n",
2913 target_pid_to_str (lp
->ptid
));
2917 /* Reset SIGNALLED only after the stop_wait_callback call
2918 above as it does gdb_assert on SIGNALLED. */
2926 /* Return non-zero if LP has a wait status pending. */
2929 status_callback (struct lwp_info
*lp
, void *data
)
2931 /* Only report a pending wait status if we pretend that this has
2932 indeed been resumed. */
2936 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
2938 /* A ptrace event, like PTRACE_FORK|VFORK|EXEC, syscall event,
2939 or a pending process exit. Note that `W_EXITCODE(0,0) ==
2940 0', so a clean process exit can not be stored pending in
2941 lp->status, it is indistinguishable from
2942 no-pending-status. */
2946 if (lp
->status
!= 0)
2952 /* Return non-zero if LP isn't stopped. */
2955 running_callback (struct lwp_info
*lp
, void *data
)
2957 return (!lp
->stopped
2958 || ((lp
->status
!= 0
2959 || lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
2963 /* Count the LWP's that have had events. */
2966 count_events_callback (struct lwp_info
*lp
, void *data
)
2970 gdb_assert (count
!= NULL
);
2972 /* Count only resumed LWPs that have a SIGTRAP event pending. */
2973 if (lp
->resumed
&& linux_nat_lp_status_is_event (lp
))
2979 /* Select the LWP (if any) that is currently being single-stepped. */
2982 select_singlestep_lwp_callback (struct lwp_info
*lp
, void *data
)
2984 if (lp
->last_resume_kind
== resume_step
2991 /* Select the Nth LWP that has had a SIGTRAP event. */
2994 select_event_lwp_callback (struct lwp_info
*lp
, void *data
)
2996 int *selector
= data
;
2998 gdb_assert (selector
!= NULL
);
3000 /* Select only resumed LWPs that have a SIGTRAP event pending. */
3001 if (lp
->resumed
&& linux_nat_lp_status_is_event (lp
))
3002 if ((*selector
)-- == 0)
3009 cancel_breakpoint (struct lwp_info
*lp
)
3011 /* Arrange for a breakpoint to be hit again later. We don't keep
3012 the SIGTRAP status and don't forward the SIGTRAP signal to the
3013 LWP. We will handle the current event, eventually we will resume
3014 this LWP, and this breakpoint will trap again.
3016 If we do not do this, then we run the risk that the user will
3017 delete or disable the breakpoint, but the LWP will have already
3020 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3021 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3024 pc
= regcache_read_pc (regcache
) - gdbarch_decr_pc_after_break (gdbarch
);
3025 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
3027 if (debug_linux_nat
)
3028 fprintf_unfiltered (gdb_stdlog
,
3029 "CB: Push back breakpoint for %s\n",
3030 target_pid_to_str (lp
->ptid
));
3032 /* Back up the PC if necessary. */
3033 if (gdbarch_decr_pc_after_break (gdbarch
))
3034 regcache_write_pc (regcache
, pc
);
3042 cancel_breakpoints_callback (struct lwp_info
*lp
, void *data
)
3044 struct lwp_info
*event_lp
= data
;
3046 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
3050 /* If a LWP other than the LWP that we're reporting an event for has
3051 hit a GDB breakpoint (as opposed to some random trap signal),
3052 then just arrange for it to hit it again later. We don't keep
3053 the SIGTRAP status and don't forward the SIGTRAP signal to the
3054 LWP. We will handle the current event, eventually we will resume
3055 all LWPs, and this one will get its breakpoint trap again.
3057 If we do not do this, then we run the risk that the user will
3058 delete or disable the breakpoint, but the LWP will have already
3061 if (linux_nat_lp_status_is_event (lp
)
3062 && cancel_breakpoint (lp
))
3063 /* Throw away the SIGTRAP. */
3069 /* Select one LWP out of those that have events pending. */
3072 select_event_lwp (ptid_t filter
, struct lwp_info
**orig_lp
, int *status
)
3075 int random_selector
;
3076 struct lwp_info
*event_lp
;
3078 /* Record the wait status for the original LWP. */
3079 (*orig_lp
)->status
= *status
;
3081 /* Give preference to any LWP that is being single-stepped. */
3082 event_lp
= iterate_over_lwps (filter
,
3083 select_singlestep_lwp_callback
, NULL
);
3084 if (event_lp
!= NULL
)
3086 if (debug_linux_nat
)
3087 fprintf_unfiltered (gdb_stdlog
,
3088 "SEL: Select single-step %s\n",
3089 target_pid_to_str (event_lp
->ptid
));
3093 /* No single-stepping LWP. Select one at random, out of those
3094 which have had SIGTRAP events. */
3096 /* First see how many SIGTRAP events we have. */
3097 iterate_over_lwps (filter
, count_events_callback
, &num_events
);
3099 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
3100 random_selector
= (int)
3101 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
3103 if (debug_linux_nat
&& num_events
> 1)
3104 fprintf_unfiltered (gdb_stdlog
,
3105 "SEL: Found %d SIGTRAP events, selecting #%d\n",
3106 num_events
, random_selector
);
3108 event_lp
= iterate_over_lwps (filter
,
3109 select_event_lwp_callback
,
3113 if (event_lp
!= NULL
)
3115 /* Switch the event LWP. */
3116 *orig_lp
= event_lp
;
3117 *status
= event_lp
->status
;
3120 /* Flush the wait status for the event LWP. */
3121 (*orig_lp
)->status
= 0;
3124 /* Return non-zero if LP has been resumed. */
3127 resumed_callback (struct lwp_info
*lp
, void *data
)
3132 /* Stop an active thread, verify it still exists, then resume it. If
3133 the thread ends up with a pending status, then it is not resumed,
3134 and *DATA (really a pointer to int), is set. */
3137 stop_and_resume_callback (struct lwp_info
*lp
, void *data
)
3139 int *new_pending_p
= data
;
3143 ptid_t ptid
= lp
->ptid
;
3145 stop_callback (lp
, NULL
);
3146 stop_wait_callback (lp
, NULL
);
3148 /* Resume if the lwp still exists, and the core wanted it
3150 lp
= find_lwp_pid (ptid
);
3153 if (lp
->last_resume_kind
== resume_stop
3156 /* The core wanted the LWP to stop. Even if it stopped
3157 cleanly (with SIGSTOP), leave the event pending. */
3158 if (debug_linux_nat
)
3159 fprintf_unfiltered (gdb_stdlog
,
3160 "SARC: core wanted LWP %ld stopped "
3161 "(leaving SIGSTOP pending)\n",
3162 GET_LWP (lp
->ptid
));
3163 lp
->status
= W_STOPCODE (SIGSTOP
);
3166 if (lp
->status
== 0)
3168 if (debug_linux_nat
)
3169 fprintf_unfiltered (gdb_stdlog
,
3170 "SARC: re-resuming LWP %ld\n",
3171 GET_LWP (lp
->ptid
));
3172 resume_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
3176 if (debug_linux_nat
)
3177 fprintf_unfiltered (gdb_stdlog
,
3178 "SARC: not re-resuming LWP %ld "
3180 GET_LWP (lp
->ptid
));
3189 /* Check if we should go on and pass this event to common code.
3190 Return the affected lwp if we are, or NULL otherwise. If we stop
3191 all lwps temporarily, we may end up with new pending events in some
3192 other lwp. In that case set *NEW_PENDING_P to true. */
3194 static struct lwp_info
*
3195 linux_nat_filter_event (int lwpid
, int status
, int *new_pending_p
)
3197 struct lwp_info
*lp
;
3201 lp
= find_lwp_pid (pid_to_ptid (lwpid
));
3203 /* Check for stop events reported by a process we didn't already
3204 know about - anything not already in our LWP list.
3206 If we're expecting to receive stopped processes after
3207 fork, vfork, and clone events, then we'll just add the
3208 new one to our list and go back to waiting for the event
3209 to be reported - the stopped process might be returned
3210 from waitpid before or after the event is.
3212 But note the case of a non-leader thread exec'ing after the
3213 leader having exited, and gone from our lists. The non-leader
3214 thread changes its tid to the tgid. */
3216 if (WIFSTOPPED (status
) && lp
== NULL
3217 && (WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 == PTRACE_EVENT_EXEC
))
3219 /* A multi-thread exec after we had seen the leader exiting. */
3220 if (debug_linux_nat
)
3221 fprintf_unfiltered (gdb_stdlog
,
3222 "LLW: Re-adding thread group leader LWP %d.\n",
3225 lp
= add_lwp (BUILD_LWP (lwpid
, lwpid
));
3228 add_thread (lp
->ptid
);
3231 if (WIFSTOPPED (status
) && !lp
)
3233 add_to_pid_list (&stopped_pids
, lwpid
, status
);
3237 /* Make sure we don't report an event for the exit of an LWP not in
3238 our list, i.e. not part of the current process. This can happen
3239 if we detach from a program we originally forked and then it
3241 if (!WIFSTOPPED (status
) && !lp
)
3244 /* Handle GNU/Linux's syscall SIGTRAPs. */
3245 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
3247 /* No longer need the sysgood bit. The ptrace event ends up
3248 recorded in lp->waitstatus if we care for it. We can carry
3249 on handling the event like a regular SIGTRAP from here
3251 status
= W_STOPCODE (SIGTRAP
);
3252 if (linux_handle_syscall_trap (lp
, 0))
3256 /* Handle GNU/Linux's extended waitstatus for trace events. */
3257 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 != 0)
3259 if (debug_linux_nat
)
3260 fprintf_unfiltered (gdb_stdlog
,
3261 "LLW: Handling extended status 0x%06x\n",
3263 if (linux_handle_extended_wait (lp
, status
, 0))
3267 if (linux_nat_status_is_event (status
))
3270 /* Check if the thread has exited. */
3271 if ((WIFEXITED (status
) || WIFSIGNALED (status
))
3272 && num_lwps (GET_PID (lp
->ptid
)) > 1)
3274 /* If this is the main thread, we must stop all threads and verify
3275 if they are still alive. This is because in the nptl thread model
3276 on Linux 2.4, there is no signal issued for exiting LWPs
3277 other than the main thread. We only get the main thread exit
3278 signal once all child threads have already exited. If we
3279 stop all the threads and use the stop_wait_callback to check
3280 if they have exited we can determine whether this signal
3281 should be ignored or whether it means the end of the debugged
3282 application, regardless of which threading model is being
3284 if (GET_PID (lp
->ptid
) == GET_LWP (lp
->ptid
))
3287 iterate_over_lwps (pid_to_ptid (GET_PID (lp
->ptid
)),
3288 stop_and_resume_callback
, new_pending_p
);
3291 if (debug_linux_nat
)
3292 fprintf_unfiltered (gdb_stdlog
,
3293 "LLW: %s exited.\n",
3294 target_pid_to_str (lp
->ptid
));
3296 if (num_lwps (GET_PID (lp
->ptid
)) > 1)
3298 /* If there is at least one more LWP, then the exit signal
3299 was not the end of the debugged application and should be
3306 /* Check if the current LWP has previously exited. In the nptl
3307 thread model, LWPs other than the main thread do not issue
3308 signals when they exit so we must check whenever the thread has
3309 stopped. A similar check is made in stop_wait_callback(). */
3310 if (num_lwps (GET_PID (lp
->ptid
)) > 1 && !linux_thread_alive (lp
->ptid
))
3312 ptid_t ptid
= pid_to_ptid (GET_PID (lp
->ptid
));
3314 if (debug_linux_nat
)
3315 fprintf_unfiltered (gdb_stdlog
,
3316 "LLW: %s exited.\n",
3317 target_pid_to_str (lp
->ptid
));
3321 /* Make sure there is at least one thread running. */
3322 gdb_assert (iterate_over_lwps (ptid
, running_callback
, NULL
));
3324 /* Discard the event. */
3328 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3329 an attempt to stop an LWP. */
3331 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGSTOP
)
3333 if (debug_linux_nat
)
3334 fprintf_unfiltered (gdb_stdlog
,
3335 "LLW: Delayed SIGSTOP caught for %s.\n",
3336 target_pid_to_str (lp
->ptid
));
3340 if (lp
->last_resume_kind
!= resume_stop
)
3342 /* This is a delayed SIGSTOP. */
3344 registers_changed ();
3346 if (linux_nat_prepare_to_resume
!= NULL
)
3347 linux_nat_prepare_to_resume (lp
);
3348 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
3349 lp
->step
, GDB_SIGNAL_0
);
3350 if (debug_linux_nat
)
3351 fprintf_unfiltered (gdb_stdlog
,
3352 "LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
3354 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3355 target_pid_to_str (lp
->ptid
));
3358 gdb_assert (lp
->resumed
);
3360 /* Discard the event. */
3365 /* Make sure we don't report a SIGINT that we have already displayed
3366 for another thread. */
3367 if (lp
->ignore_sigint
3368 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGINT
)
3370 if (debug_linux_nat
)
3371 fprintf_unfiltered (gdb_stdlog
,
3372 "LLW: Delayed SIGINT caught for %s.\n",
3373 target_pid_to_str (lp
->ptid
));
3375 /* This is a delayed SIGINT. */
3376 lp
->ignore_sigint
= 0;
3378 registers_changed ();
3379 if (linux_nat_prepare_to_resume
!= NULL
)
3380 linux_nat_prepare_to_resume (lp
);
3381 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
3382 lp
->step
, GDB_SIGNAL_0
);
3383 if (debug_linux_nat
)
3384 fprintf_unfiltered (gdb_stdlog
,
3385 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3387 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3388 target_pid_to_str (lp
->ptid
));
3391 gdb_assert (lp
->resumed
);
3393 /* Discard the event. */
3397 /* An interesting event. */
3399 lp
->status
= status
;
3403 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3404 their exits until all other threads in the group have exited. */
3407 check_zombie_leaders (void)
3409 struct inferior
*inf
;
3413 struct lwp_info
*leader_lp
;
3418 leader_lp
= find_lwp_pid (pid_to_ptid (inf
->pid
));
3419 if (leader_lp
!= NULL
3420 /* Check if there are other threads in the group, as we may
3421 have raced with the inferior simply exiting. */
3422 && num_lwps (inf
->pid
) > 1
3423 && linux_proc_pid_is_zombie (inf
->pid
))
3425 if (debug_linux_nat
)
3426 fprintf_unfiltered (gdb_stdlog
,
3427 "CZL: Thread group leader %d zombie "
3428 "(it exited, or another thread execd).\n",
3431 /* A leader zombie can mean one of two things:
3433 - It exited, and there's an exit status pending
3434 available, or only the leader exited (not the whole
3435 program). In the latter case, we can't waitpid the
3436 leader's exit status until all other threads are gone.
3438 - There are 3 or more threads in the group, and a thread
3439 other than the leader exec'd. On an exec, the Linux
3440 kernel destroys all other threads (except the execing
3441 one) in the thread group, and resets the execing thread's
3442 tid to the tgid. No exit notification is sent for the
3443 execing thread -- from the ptracer's perspective, it
3444 appears as though the execing thread just vanishes.
3445 Until we reap all other threads except the leader and the
3446 execing thread, the leader will be zombie, and the
3447 execing thread will be in `D (disc sleep)'. As soon as
3448 all other threads are reaped, the execing thread changes
3449 it's tid to the tgid, and the previous (zombie) leader
3450 vanishes, giving place to the "new" leader. We could try
3451 distinguishing the exit and exec cases, by waiting once
3452 more, and seeing if something comes out, but it doesn't
3453 sound useful. The previous leader _does_ go away, and
3454 we'll re-add the new one once we see the exec event
3455 (which is just the same as what would happen if the
3456 previous leader did exit voluntarily before some other
3459 if (debug_linux_nat
)
3460 fprintf_unfiltered (gdb_stdlog
,
3461 "CZL: Thread group leader %d vanished.\n",
3463 exit_lwp (leader_lp
);
3469 linux_nat_wait_1 (struct target_ops
*ops
,
3470 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3473 static sigset_t prev_mask
;
3474 enum resume_kind last_resume_kind
;
3475 struct lwp_info
*lp
;
3478 if (debug_linux_nat
)
3479 fprintf_unfiltered (gdb_stdlog
, "LLW: enter\n");
3481 /* The first time we get here after starting a new inferior, we may
3482 not have added it to the LWP list yet - this is the earliest
3483 moment at which we know its PID. */
3484 if (ptid_is_pid (inferior_ptid
))
3486 /* Upgrade the main thread's ptid. */
3487 thread_change_ptid (inferior_ptid
,
3488 BUILD_LWP (GET_PID (inferior_ptid
),
3489 GET_PID (inferior_ptid
)));
3491 lp
= add_lwp (inferior_ptid
);
3495 /* Make sure SIGCHLD is blocked. */
3496 block_child_signals (&prev_mask
);
3502 /* First check if there is a LWP with a wait status pending. */
3503 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3505 /* Any LWP in the PTID group that's been resumed will do. */
3506 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3509 if (debug_linux_nat
&& lp
->status
)
3510 fprintf_unfiltered (gdb_stdlog
,
3511 "LLW: Using pending wait status %s for %s.\n",
3512 status_to_str (lp
->status
),
3513 target_pid_to_str (lp
->ptid
));
3516 else if (is_lwp (ptid
))
3518 if (debug_linux_nat
)
3519 fprintf_unfiltered (gdb_stdlog
,
3520 "LLW: Waiting for specific LWP %s.\n",
3521 target_pid_to_str (ptid
));
3523 /* We have a specific LWP to check. */
3524 lp
= find_lwp_pid (ptid
);
3527 if (debug_linux_nat
&& lp
->status
)
3528 fprintf_unfiltered (gdb_stdlog
,
3529 "LLW: Using pending wait status %s for %s.\n",
3530 status_to_str (lp
->status
),
3531 target_pid_to_str (lp
->ptid
));
3533 /* We check for lp->waitstatus in addition to lp->status,
3534 because we can have pending process exits recorded in
3535 lp->status and W_EXITCODE(0,0) == 0. We should probably have
3536 an additional lp->status_p flag. */
3537 if (lp
->status
== 0 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
3541 if (!target_can_async_p ())
3543 /* Causes SIGINT to be passed on to the attached process. */
3547 /* But if we don't find a pending event, we'll have to wait. */
3553 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3556 - If the thread group leader exits while other threads in the
3557 thread group still exist, waitpid(TGID, ...) hangs. That
3558 waitpid won't return an exit status until the other threads
3559 in the group are reapped.
3561 - When a non-leader thread execs, that thread just vanishes
3562 without reporting an exit (so we'd hang if we waited for it
3563 explicitly in that case). The exec event is reported to
3567 lwpid
= my_waitpid (-1, &status
, __WCLONE
| WNOHANG
);
3568 if (lwpid
== 0 || (lwpid
== -1 && errno
== ECHILD
))
3569 lwpid
= my_waitpid (-1, &status
, WNOHANG
);
3571 if (debug_linux_nat
)
3572 fprintf_unfiltered (gdb_stdlog
,
3573 "LNW: waitpid(-1, ...) returned %d, %s\n",
3574 lwpid
, errno
? safe_strerror (errno
) : "ERRNO-OK");
3578 /* If this is true, then we paused LWPs momentarily, and may
3579 now have pending events to handle. */
3582 if (debug_linux_nat
)
3584 fprintf_unfiltered (gdb_stdlog
,
3585 "LLW: waitpid %ld received %s\n",
3586 (long) lwpid
, status_to_str (status
));
3589 lp
= linux_nat_filter_event (lwpid
, status
, &new_pending
);
3591 /* STATUS is now no longer valid, use LP->STATUS instead. */
3594 if (lp
&& !ptid_match (lp
->ptid
, ptid
))
3596 gdb_assert (lp
->resumed
);
3598 if (debug_linux_nat
)
3600 "LWP %ld got an event %06x, leaving pending.\n",
3601 ptid_get_lwp (lp
->ptid
), lp
->status
);
3603 if (WIFSTOPPED (lp
->status
))
3605 if (WSTOPSIG (lp
->status
) != SIGSTOP
)
3607 /* Cancel breakpoint hits. The breakpoint may
3608 be removed before we fetch events from this
3609 process to report to the core. It is best
3610 not to assume the moribund breakpoints
3611 heuristic always handles these cases --- it
3612 could be too many events go through to the
3613 core before this one is handled. All-stop
3614 always cancels breakpoint hits in all
3617 && linux_nat_lp_status_is_event (lp
)
3618 && cancel_breakpoint (lp
))
3620 /* Throw away the SIGTRAP. */
3623 if (debug_linux_nat
)
3625 "LLW: LWP %ld hit a breakpoint while"
3626 " waiting for another process;"
3628 ptid_get_lwp (lp
->ptid
));
3638 else if (WIFEXITED (lp
->status
) || WIFSIGNALED (lp
->status
))
3640 if (debug_linux_nat
)
3642 "Process %ld exited while stopping LWPs\n",
3643 ptid_get_lwp (lp
->ptid
));
3645 /* This was the last lwp in the process. Since
3646 events are serialized to GDB core, and we can't
3647 report this one right now, but GDB core and the
3648 other target layers will want to be notified
3649 about the exit code/signal, leave the status
3650 pending for the next time we're able to report
3653 /* Prevent trying to stop this thread again. We'll
3654 never try to resume it because it has a pending
3658 /* Dead LWP's aren't expected to reported a pending
3662 /* Store the pending event in the waitstatus as
3663 well, because W_EXITCODE(0,0) == 0. */
3664 store_waitstatus (&lp
->waitstatus
, lp
->status
);
3673 /* Some LWP now has a pending event. Go all the way
3674 back to check it. */
3680 /* We got an event to report to the core. */
3684 /* Retry until nothing comes out of waitpid. A single
3685 SIGCHLD can indicate more than one child stopped. */
3689 /* Check for zombie thread group leaders. Those can't be reaped
3690 until all other threads in the thread group are. */
3691 check_zombie_leaders ();
3693 /* If there are no resumed children left, bail. We'd be stuck
3694 forever in the sigsuspend call below otherwise. */
3695 if (iterate_over_lwps (ptid
, resumed_callback
, NULL
) == NULL
)
3697 if (debug_linux_nat
)
3698 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (no resumed LWP)\n");
3700 ourstatus
->kind
= TARGET_WAITKIND_NO_RESUMED
;
3702 if (!target_can_async_p ())
3703 clear_sigint_trap ();
3705 restore_child_signals_mask (&prev_mask
);
3706 return minus_one_ptid
;
3709 /* No interesting event to report to the core. */
3711 if (target_options
& TARGET_WNOHANG
)
3713 if (debug_linux_nat
)
3714 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (ignore)\n");
3716 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3717 restore_child_signals_mask (&prev_mask
);
3718 return minus_one_ptid
;
3721 /* We shouldn't end up here unless we want to try again. */
3722 gdb_assert (lp
== NULL
);
3724 /* Block until we get an event reported with SIGCHLD. */
3725 sigsuspend (&suspend_mask
);
3728 if (!target_can_async_p ())
3729 clear_sigint_trap ();
3733 status
= lp
->status
;
3736 /* Don't report signals that GDB isn't interested in, such as
3737 signals that are neither printed nor stopped upon. Stopping all
3738 threads can be a bit time-consuming so if we want decent
3739 performance with heavily multi-threaded programs, especially when
3740 they're using a high frequency timer, we'd better avoid it if we
3743 if (WIFSTOPPED (status
))
3745 enum gdb_signal signo
= gdb_signal_from_host (WSTOPSIG (status
));
3747 /* When using hardware single-step, we need to report every signal.
3748 Otherwise, signals in pass_mask may be short-circuited. */
3750 && WSTOPSIG (status
) && sigismember (&pass_mask
, WSTOPSIG (status
)))
3752 /* FIMXE: kettenis/2001-06-06: Should we resume all threads
3753 here? It is not clear we should. GDB may not expect
3754 other threads to run. On the other hand, not resuming
3755 newly attached threads may cause an unwanted delay in
3756 getting them running. */
3757 registers_changed ();
3758 if (linux_nat_prepare_to_resume
!= NULL
)
3759 linux_nat_prepare_to_resume (lp
);
3760 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
3762 if (debug_linux_nat
)
3763 fprintf_unfiltered (gdb_stdlog
,
3764 "LLW: %s %s, %s (preempt 'handle')\n",
3766 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3767 target_pid_to_str (lp
->ptid
),
3768 (signo
!= GDB_SIGNAL_0
3769 ? strsignal (gdb_signal_to_host (signo
))
3777 /* Only do the below in all-stop, as we currently use SIGINT
3778 to implement target_stop (see linux_nat_stop) in
3780 if (signo
== GDB_SIGNAL_INT
&& signal_pass_state (signo
) == 0)
3782 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3783 forwarded to the entire process group, that is, all LWPs
3784 will receive it - unless they're using CLONE_THREAD to
3785 share signals. Since we only want to report it once, we
3786 mark it as ignored for all LWPs except this one. */
3787 iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid
)),
3788 set_ignore_sigint
, NULL
);
3789 lp
->ignore_sigint
= 0;
3792 maybe_clear_ignore_sigint (lp
);
3796 /* This LWP is stopped now. */
3799 if (debug_linux_nat
)
3800 fprintf_unfiltered (gdb_stdlog
, "LLW: Candidate event %s in %s.\n",
3801 status_to_str (status
), target_pid_to_str (lp
->ptid
));
3805 /* Now stop all other LWP's ... */
3806 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
3808 /* ... and wait until all of them have reported back that
3809 they're no longer running. */
3810 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
3812 /* If we're not waiting for a specific LWP, choose an event LWP
3813 from among those that have had events. Giving equal priority
3814 to all LWPs that have had events helps prevent
3816 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3817 select_event_lwp (ptid
, &lp
, &status
);
3819 /* Now that we've selected our final event LWP, cancel any
3820 breakpoints in other LWPs that have hit a GDB breakpoint.
3821 See the comment in cancel_breakpoints_callback to find out
3823 iterate_over_lwps (minus_one_ptid
, cancel_breakpoints_callback
, lp
);
3825 /* We'll need this to determine whether to report a SIGSTOP as
3826 TARGET_WAITKIND_0. Need to take a copy because
3827 resume_clear_callback clears it. */
3828 last_resume_kind
= lp
->last_resume_kind
;
3830 /* In all-stop, from the core's perspective, all LWPs are now
3831 stopped until a new resume action is sent over. */
3832 iterate_over_lwps (minus_one_ptid
, resume_clear_callback
, NULL
);
3837 last_resume_kind
= lp
->last_resume_kind
;
3838 resume_clear_callback (lp
, NULL
);
3841 if (linux_nat_status_is_event (status
))
3843 if (debug_linux_nat
)
3844 fprintf_unfiltered (gdb_stdlog
,
3845 "LLW: trap ptid is %s.\n",
3846 target_pid_to_str (lp
->ptid
));
3849 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3851 *ourstatus
= lp
->waitstatus
;
3852 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3855 store_waitstatus (ourstatus
, status
);
3857 if (debug_linux_nat
)
3858 fprintf_unfiltered (gdb_stdlog
, "LLW: exit\n");
3860 restore_child_signals_mask (&prev_mask
);
3862 if (last_resume_kind
== resume_stop
3863 && ourstatus
->kind
== TARGET_WAITKIND_STOPPED
3864 && WSTOPSIG (status
) == SIGSTOP
)
3866 /* A thread that has been requested to stop by GDB with
3867 target_stop, and it stopped cleanly, so report as SIG0. The
3868 use of SIGSTOP is an implementation detail. */
3869 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3872 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
3873 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
3876 lp
->core
= linux_common_core_of_thread (lp
->ptid
);
3881 /* Resume LWPs that are currently stopped without any pending status
3882 to report, but are resumed from the core's perspective. */
3885 resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
)
3887 ptid_t
*wait_ptid_p
= data
;
3892 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
3894 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3895 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3896 CORE_ADDR pc
= regcache_read_pc (regcache
);
3898 gdb_assert (is_executing (lp
->ptid
));
3900 /* Don't bother if there's a breakpoint at PC that we'd hit
3901 immediately, and we're not waiting for this LWP. */
3902 if (!ptid_match (lp
->ptid
, *wait_ptid_p
))
3904 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
3908 if (debug_linux_nat
)
3909 fprintf_unfiltered (gdb_stdlog
,
3910 "RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n",
3911 target_pid_to_str (lp
->ptid
),
3912 paddress (gdbarch
, pc
),
3915 registers_changed ();
3916 if (linux_nat_prepare_to_resume
!= NULL
)
3917 linux_nat_prepare_to_resume (lp
);
3918 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
3919 lp
->step
, GDB_SIGNAL_0
);
3921 lp
->stopped_by_watchpoint
= 0;
3928 linux_nat_wait (struct target_ops
*ops
,
3929 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3934 if (debug_linux_nat
)
3935 fprintf_unfiltered (gdb_stdlog
,
3936 "linux_nat_wait: [%s]\n", target_pid_to_str (ptid
));
3938 /* Flush the async file first. */
3939 if (target_can_async_p ())
3940 async_file_flush ();
3942 /* Resume LWPs that are currently stopped without any pending status
3943 to report, but are resumed from the core's perspective. LWPs get
3944 in this state if we find them stopping at a time we're not
3945 interested in reporting the event (target_wait on a
3946 specific_process, for example, see linux_nat_wait_1), and
3947 meanwhile the event became uninteresting. Don't bother resuming
3948 LWPs we're not going to wait for if they'd stop immediately. */
3950 iterate_over_lwps (minus_one_ptid
, resume_stopped_resumed_lwps
, &ptid
);
3952 event_ptid
= linux_nat_wait_1 (ops
, ptid
, ourstatus
, target_options
);
3954 /* If we requested any event, and something came out, assume there
3955 may be more. If we requested a specific lwp or process, also
3956 assume there may be more. */
3957 if (target_can_async_p ()
3958 && ((ourstatus
->kind
!= TARGET_WAITKIND_IGNORE
3959 && ourstatus
->kind
!= TARGET_WAITKIND_NO_RESUMED
)
3960 || !ptid_equal (ptid
, minus_one_ptid
)))
3963 /* Get ready for the next event. */
3964 if (target_can_async_p ())
3965 target_async (inferior_event_handler
, 0);
3971 kill_callback (struct lwp_info
*lp
, void *data
)
3973 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3976 kill (GET_LWP (lp
->ptid
), SIGKILL
);
3977 if (debug_linux_nat
)
3978 fprintf_unfiltered (gdb_stdlog
,
3979 "KC: kill (SIGKILL) %s, 0, 0 (%s)\n",
3980 target_pid_to_str (lp
->ptid
),
3981 errno
? safe_strerror (errno
) : "OK");
3983 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3986 ptrace (PTRACE_KILL
, GET_LWP (lp
->ptid
), 0, 0);
3987 if (debug_linux_nat
)
3988 fprintf_unfiltered (gdb_stdlog
,
3989 "KC: PTRACE_KILL %s, 0, 0 (%s)\n",
3990 target_pid_to_str (lp
->ptid
),
3991 errno
? safe_strerror (errno
) : "OK");
3997 kill_wait_callback (struct lwp_info
*lp
, void *data
)
4001 /* We must make sure that there are no pending events (delayed
4002 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
4003 program doesn't interfere with any following debugging session. */
4005 /* For cloned processes we must check both with __WCLONE and
4006 without, since the exit status of a cloned process isn't reported
4012 pid
= my_waitpid (GET_LWP (lp
->ptid
), NULL
, __WCLONE
);
4013 if (pid
!= (pid_t
) -1)
4015 if (debug_linux_nat
)
4016 fprintf_unfiltered (gdb_stdlog
,
4017 "KWC: wait %s received unknown.\n",
4018 target_pid_to_str (lp
->ptid
));
4019 /* The Linux kernel sometimes fails to kill a thread
4020 completely after PTRACE_KILL; that goes from the stop
4021 point in do_fork out to the one in
4022 get_signal_to_deliever and waits again. So kill it
4024 kill_callback (lp
, NULL
);
4027 while (pid
== GET_LWP (lp
->ptid
));
4029 gdb_assert (pid
== -1 && errno
== ECHILD
);
4034 pid
= my_waitpid (GET_LWP (lp
->ptid
), NULL
, 0);
4035 if (pid
!= (pid_t
) -1)
4037 if (debug_linux_nat
)
4038 fprintf_unfiltered (gdb_stdlog
,
4039 "KWC: wait %s received unk.\n",
4040 target_pid_to_str (lp
->ptid
));
4041 /* See the call to kill_callback above. */
4042 kill_callback (lp
, NULL
);
4045 while (pid
== GET_LWP (lp
->ptid
));
4047 gdb_assert (pid
== -1 && errno
== ECHILD
);
4052 linux_nat_kill (struct target_ops
*ops
)
4054 struct target_waitstatus last
;
4058 /* If we're stopped while forking and we haven't followed yet,
4059 kill the other task. We need to do this first because the
4060 parent will be sleeping if this is a vfork. */
4062 get_last_target_status (&last_ptid
, &last
);
4064 if (last
.kind
== TARGET_WAITKIND_FORKED
4065 || last
.kind
== TARGET_WAITKIND_VFORKED
)
4067 ptrace (PT_KILL
, PIDGET (last
.value
.related_pid
), 0, 0);
4071 if (forks_exist_p ())
4072 linux_fork_killall ();
4075 ptid_t ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
4077 /* Stop all threads before killing them, since ptrace requires
4078 that the thread is stopped to sucessfully PTRACE_KILL. */
4079 iterate_over_lwps (ptid
, stop_callback
, NULL
);
4080 /* ... and wait until all of them have reported back that
4081 they're no longer running. */
4082 iterate_over_lwps (ptid
, stop_wait_callback
, NULL
);
4084 /* Kill all LWP's ... */
4085 iterate_over_lwps (ptid
, kill_callback
, NULL
);
4087 /* ... and wait until we've flushed all events. */
4088 iterate_over_lwps (ptid
, kill_wait_callback
, NULL
);
4091 target_mourn_inferior ();
4095 linux_nat_mourn_inferior (struct target_ops
*ops
)
4097 purge_lwp_list (ptid_get_pid (inferior_ptid
));
4099 if (! forks_exist_p ())
4100 /* Normal case, no other forks available. */
4101 linux_ops
->to_mourn_inferior (ops
);
4103 /* Multi-fork case. The current inferior_ptid has exited, but
4104 there are other viable forks to debug. Delete the exiting
4105 one and context-switch to the first available. */
4106 linux_fork_mourn_inferior ();
4109 /* Convert a native/host siginfo object, into/from the siginfo in the
4110 layout of the inferiors' architecture. */
4113 siginfo_fixup (siginfo_t
*siginfo
, gdb_byte
*inf_siginfo
, int direction
)
4117 if (linux_nat_siginfo_fixup
!= NULL
)
4118 done
= linux_nat_siginfo_fixup (siginfo
, inf_siginfo
, direction
);
4120 /* If there was no callback, or the callback didn't do anything,
4121 then just do a straight memcpy. */
4125 memcpy (siginfo
, inf_siginfo
, sizeof (siginfo_t
));
4127 memcpy (inf_siginfo
, siginfo
, sizeof (siginfo_t
));
4132 linux_xfer_siginfo (struct target_ops
*ops
, enum target_object object
,
4133 const char *annex
, gdb_byte
*readbuf
,
4134 const gdb_byte
*writebuf
, ULONGEST offset
, LONGEST len
)
4138 gdb_byte inf_siginfo
[sizeof (siginfo_t
)];
4140 gdb_assert (object
== TARGET_OBJECT_SIGNAL_INFO
);
4141 gdb_assert (readbuf
|| writebuf
);
4143 pid
= GET_LWP (inferior_ptid
);
4145 pid
= GET_PID (inferior_ptid
);
4147 if (offset
> sizeof (siginfo
))
4151 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
4155 /* When GDB is built as a 64-bit application, ptrace writes into
4156 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
4157 inferior with a 64-bit GDB should look the same as debugging it
4158 with a 32-bit GDB, we need to convert it. GDB core always sees
4159 the converted layout, so any read/write will have to be done
4161 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
4163 if (offset
+ len
> sizeof (siginfo
))
4164 len
= sizeof (siginfo
) - offset
;
4166 if (readbuf
!= NULL
)
4167 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
4170 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
4172 /* Convert back to ptrace layout before flushing it out. */
4173 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
4176 ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
4185 linux_nat_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4186 const char *annex
, gdb_byte
*readbuf
,
4187 const gdb_byte
*writebuf
,
4188 ULONGEST offset
, LONGEST len
)
4190 struct cleanup
*old_chain
;
4193 if (object
== TARGET_OBJECT_SIGNAL_INFO
)
4194 return linux_xfer_siginfo (ops
, object
, annex
, readbuf
, writebuf
,
4197 /* The target is connected but no live inferior is selected. Pass
4198 this request down to a lower stratum (e.g., the executable
4200 if (object
== TARGET_OBJECT_MEMORY
&& ptid_equal (inferior_ptid
, null_ptid
))
4203 old_chain
= save_inferior_ptid ();
4205 if (is_lwp (inferior_ptid
))
4206 inferior_ptid
= pid_to_ptid (GET_LWP (inferior_ptid
));
4208 xfer
= linux_ops
->to_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4211 do_cleanups (old_chain
);
4216 linux_thread_alive (ptid_t ptid
)
4220 gdb_assert (is_lwp (ptid
));
4222 /* Send signal 0 instead of anything ptrace, because ptracing a
4223 running thread errors out claiming that the thread doesn't
4225 err
= kill_lwp (GET_LWP (ptid
), 0);
4227 if (debug_linux_nat
)
4228 fprintf_unfiltered (gdb_stdlog
,
4229 "LLTA: KILL(SIG0) %s (%s)\n",
4230 target_pid_to_str (ptid
),
4231 err
? safe_strerror (tmp_errno
) : "OK");
4240 linux_nat_thread_alive (struct target_ops
*ops
, ptid_t ptid
)
4242 return linux_thread_alive (ptid
);
4246 linux_nat_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
4248 static char buf
[64];
4251 && (GET_PID (ptid
) != GET_LWP (ptid
)
4252 || num_lwps (GET_PID (ptid
)) > 1))
4254 snprintf (buf
, sizeof (buf
), "LWP %ld", GET_LWP (ptid
));
4258 return normal_pid_to_str (ptid
);
4262 linux_nat_thread_name (struct thread_info
*thr
)
4264 int pid
= ptid_get_pid (thr
->ptid
);
4265 long lwp
= ptid_get_lwp (thr
->ptid
);
4266 #define FORMAT "/proc/%d/task/%ld/comm"
4267 char buf
[sizeof (FORMAT
) + 30];
4269 char *result
= NULL
;
4271 snprintf (buf
, sizeof (buf
), FORMAT
, pid
, lwp
);
4272 comm_file
= fopen (buf
, "r");
4275 /* Not exported by the kernel, so we define it here. */
4277 static char line
[COMM_LEN
+ 1];
4279 if (fgets (line
, sizeof (line
), comm_file
))
4281 char *nl
= strchr (line
, '\n');
4298 /* Accepts an integer PID; Returns a string representing a file that
4299 can be opened to get the symbols for the child process. */
4302 linux_child_pid_to_exec_file (int pid
)
4304 char *name1
, *name2
;
4306 name1
= xmalloc (MAXPATHLEN
);
4307 name2
= xmalloc (MAXPATHLEN
);
4308 make_cleanup (xfree
, name1
);
4309 make_cleanup (xfree
, name2
);
4310 memset (name2
, 0, MAXPATHLEN
);
4312 sprintf (name1
, "/proc/%d/exe", pid
);
4313 if (readlink (name1
, name2
, MAXPATHLEN
) > 0)
4319 /* Records the thread's register state for the corefile note
4323 linux_nat_collect_thread_registers (const struct regcache
*regcache
,
4324 ptid_t ptid
, bfd
*obfd
,
4325 char *note_data
, int *note_size
,
4326 enum gdb_signal stop_signal
)
4328 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
4329 const struct regset
*regset
;
4331 gdb_gregset_t gregs
;
4332 gdb_fpregset_t fpregs
;
4334 core_regset_p
= gdbarch_regset_from_core_section_p (gdbarch
);
4337 && (regset
= gdbarch_regset_from_core_section (gdbarch
, ".reg",
4339 != NULL
&& regset
->collect_regset
!= NULL
)
4340 regset
->collect_regset (regset
, regcache
, -1, &gregs
, sizeof (gregs
));
4342 fill_gregset (regcache
, &gregs
, -1);
4344 note_data
= (char *) elfcore_write_prstatus
4345 (obfd
, note_data
, note_size
, ptid_get_lwp (ptid
),
4346 gdb_signal_to_host (stop_signal
), &gregs
);
4349 && (regset
= gdbarch_regset_from_core_section (gdbarch
, ".reg2",
4351 != NULL
&& regset
->collect_regset
!= NULL
)
4352 regset
->collect_regset (regset
, regcache
, -1, &fpregs
, sizeof (fpregs
));
4354 fill_fpregset (regcache
, &fpregs
, -1);
4356 note_data
= (char *) elfcore_write_prfpreg (obfd
, note_data
, note_size
,
4357 &fpregs
, sizeof (fpregs
));
4362 /* Fills the "to_make_corefile_note" target vector. Builds the note
4363 section for a corefile, and returns it in a malloc buffer. */
4366 linux_nat_make_corefile_notes (bfd
*obfd
, int *note_size
)
4368 /* FIXME: uweigand/2011-10-06: Once all GNU/Linux architectures have been
4369 converted to gdbarch_core_regset_sections, this function can go away. */
4370 return linux_make_corefile_notes (target_gdbarch
, obfd
, note_size
,
4371 linux_nat_collect_thread_registers
);
4374 /* Implement the to_xfer_partial interface for memory reads using the /proc
4375 filesystem. Because we can use a single read() call for /proc, this
4376 can be much more efficient than banging away at PTRACE_PEEKTEXT,
4377 but it doesn't support writes. */
4380 linux_proc_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4381 const char *annex
, gdb_byte
*readbuf
,
4382 const gdb_byte
*writebuf
,
4383 ULONGEST offset
, LONGEST len
)
4389 if (object
!= TARGET_OBJECT_MEMORY
|| !readbuf
)
4392 /* Don't bother for one word. */
4393 if (len
< 3 * sizeof (long))
4396 /* We could keep this file open and cache it - possibly one per
4397 thread. That requires some juggling, but is even faster. */
4398 sprintf (filename
, "/proc/%d/mem", PIDGET (inferior_ptid
));
4399 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
4403 /* If pread64 is available, use it. It's faster if the kernel
4404 supports it (only one syscall), and it's 64-bit safe even on
4405 32-bit platforms (for instance, SPARC debugging a SPARC64
4408 if (pread64 (fd
, readbuf
, len
, offset
) != len
)
4410 if (lseek (fd
, offset
, SEEK_SET
) == -1 || read (fd
, readbuf
, len
) != len
)
4421 /* Enumerate spufs IDs for process PID. */
4423 spu_enumerate_spu_ids (int pid
, gdb_byte
*buf
, ULONGEST offset
, LONGEST len
)
4425 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch
);
4427 LONGEST written
= 0;
4430 struct dirent
*entry
;
4432 xsnprintf (path
, sizeof path
, "/proc/%d/fd", pid
);
4433 dir
= opendir (path
);
4438 while ((entry
= readdir (dir
)) != NULL
)
4444 fd
= atoi (entry
->d_name
);
4448 xsnprintf (path
, sizeof path
, "/proc/%d/fd/%d", pid
, fd
);
4449 if (stat (path
, &st
) != 0)
4451 if (!S_ISDIR (st
.st_mode
))
4454 if (statfs (path
, &stfs
) != 0)
4456 if (stfs
.f_type
!= SPUFS_MAGIC
)
4459 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4461 store_unsigned_integer (buf
+ pos
- offset
, 4, byte_order
, fd
);
4471 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4472 object type, using the /proc file system. */
4474 linux_proc_xfer_spu (struct target_ops
*ops
, enum target_object object
,
4475 const char *annex
, gdb_byte
*readbuf
,
4476 const gdb_byte
*writebuf
,
4477 ULONGEST offset
, LONGEST len
)
4482 int pid
= PIDGET (inferior_ptid
);
4489 return spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4492 xsnprintf (buf
, sizeof buf
, "/proc/%d/fd/%s", pid
, annex
);
4493 fd
= open (buf
, writebuf
? O_WRONLY
: O_RDONLY
);
4498 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4505 ret
= write (fd
, writebuf
, (size_t) len
);
4507 ret
= read (fd
, readbuf
, (size_t) len
);
4514 /* Parse LINE as a signal set and add its set bits to SIGS. */
4517 add_line_to_sigset (const char *line
, sigset_t
*sigs
)
4519 int len
= strlen (line
) - 1;
4523 if (line
[len
] != '\n')
4524 error (_("Could not parse signal set: %s"), line
);
4532 if (*p
>= '0' && *p
<= '9')
4534 else if (*p
>= 'a' && *p
<= 'f')
4535 digit
= *p
- 'a' + 10;
4537 error (_("Could not parse signal set: %s"), line
);
4542 sigaddset (sigs
, signum
+ 1);
4544 sigaddset (sigs
, signum
+ 2);
4546 sigaddset (sigs
, signum
+ 3);
4548 sigaddset (sigs
, signum
+ 4);
4554 /* Find process PID's pending signals from /proc/pid/status and set
4558 linux_proc_pending_signals (int pid
, sigset_t
*pending
,
4559 sigset_t
*blocked
, sigset_t
*ignored
)
4562 char buffer
[MAXPATHLEN
], fname
[MAXPATHLEN
];
4563 struct cleanup
*cleanup
;
4565 sigemptyset (pending
);
4566 sigemptyset (blocked
);
4567 sigemptyset (ignored
);
4568 sprintf (fname
, "/proc/%d/status", pid
);
4569 procfile
= fopen (fname
, "r");
4570 if (procfile
== NULL
)
4571 error (_("Could not open %s"), fname
);
4572 cleanup
= make_cleanup_fclose (procfile
);
4574 while (fgets (buffer
, MAXPATHLEN
, procfile
) != NULL
)
4576 /* Normal queued signals are on the SigPnd line in the status
4577 file. However, 2.6 kernels also have a "shared" pending
4578 queue for delivering signals to a thread group, so check for
4581 Unfortunately some Red Hat kernels include the shared pending
4582 queue but not the ShdPnd status field. */
4584 if (strncmp (buffer
, "SigPnd:\t", 8) == 0)
4585 add_line_to_sigset (buffer
+ 8, pending
);
4586 else if (strncmp (buffer
, "ShdPnd:\t", 8) == 0)
4587 add_line_to_sigset (buffer
+ 8, pending
);
4588 else if (strncmp (buffer
, "SigBlk:\t", 8) == 0)
4589 add_line_to_sigset (buffer
+ 8, blocked
);
4590 else if (strncmp (buffer
, "SigIgn:\t", 8) == 0)
4591 add_line_to_sigset (buffer
+ 8, ignored
);
4594 do_cleanups (cleanup
);
4598 linux_nat_xfer_osdata (struct target_ops
*ops
, enum target_object object
,
4599 const char *annex
, gdb_byte
*readbuf
,
4600 const gdb_byte
*writebuf
, ULONGEST offset
, LONGEST len
)
4602 gdb_assert (object
== TARGET_OBJECT_OSDATA
);
4604 return linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
4608 linux_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4609 const char *annex
, gdb_byte
*readbuf
,
4610 const gdb_byte
*writebuf
, ULONGEST offset
, LONGEST len
)
4614 if (object
== TARGET_OBJECT_AUXV
)
4615 return memory_xfer_auxv (ops
, object
, annex
, readbuf
, writebuf
,
4618 if (object
== TARGET_OBJECT_OSDATA
)
4619 return linux_nat_xfer_osdata (ops
, object
, annex
, readbuf
, writebuf
,
4622 if (object
== TARGET_OBJECT_SPU
)
4623 return linux_proc_xfer_spu (ops
, object
, annex
, readbuf
, writebuf
,
4626 /* GDB calculates all the addresses in possibly larget width of the address.
4627 Address width needs to be masked before its final use - either by
4628 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4630 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4632 if (object
== TARGET_OBJECT_MEMORY
)
4634 int addr_bit
= gdbarch_addr_bit (target_gdbarch
);
4636 if (addr_bit
< (sizeof (ULONGEST
) * HOST_CHAR_BIT
))
4637 offset
&= ((ULONGEST
) 1 << addr_bit
) - 1;
4640 xfer
= linux_proc_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4645 return super_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4650 cleanup_target_stop (void *arg
)
4652 ptid_t
*ptid
= (ptid_t
*) arg
;
4654 gdb_assert (arg
!= NULL
);
4657 target_resume (*ptid
, 0, GDB_SIGNAL_0
);
4660 static VEC(static_tracepoint_marker_p
) *
4661 linux_child_static_tracepoint_markers_by_strid (const char *strid
)
4663 char s
[IPA_CMD_BUF_SIZE
];
4664 struct cleanup
*old_chain
;
4665 int pid
= ptid_get_pid (inferior_ptid
);
4666 VEC(static_tracepoint_marker_p
) *markers
= NULL
;
4667 struct static_tracepoint_marker
*marker
= NULL
;
4669 ptid_t ptid
= ptid_build (pid
, 0, 0);
4674 memcpy (s
, "qTfSTM", sizeof ("qTfSTM"));
4675 s
[sizeof ("qTfSTM")] = 0;
4677 agent_run_command (pid
, s
, strlen (s
) + 1);
4679 old_chain
= make_cleanup (free_current_marker
, &marker
);
4680 make_cleanup (cleanup_target_stop
, &ptid
);
4685 marker
= XCNEW (struct static_tracepoint_marker
);
4689 parse_static_tracepoint_marker_definition (p
, &p
, marker
);
4691 if (strid
== NULL
|| strcmp (strid
, marker
->str_id
) == 0)
4693 VEC_safe_push (static_tracepoint_marker_p
,
4699 release_static_tracepoint_marker (marker
);
4700 memset (marker
, 0, sizeof (*marker
));
4703 while (*p
++ == ','); /* comma-separated list */
4705 memcpy (s
, "qTsSTM", sizeof ("qTsSTM"));
4706 s
[sizeof ("qTsSTM")] = 0;
4707 agent_run_command (pid
, s
, strlen (s
) + 1);
4711 do_cleanups (old_chain
);
4716 /* Create a prototype generic GNU/Linux target. The client can override
4717 it with local methods. */
4720 linux_target_install_ops (struct target_ops
*t
)
4722 t
->to_insert_fork_catchpoint
= linux_child_insert_fork_catchpoint
;
4723 t
->to_remove_fork_catchpoint
= linux_child_remove_fork_catchpoint
;
4724 t
->to_insert_vfork_catchpoint
= linux_child_insert_vfork_catchpoint
;
4725 t
->to_remove_vfork_catchpoint
= linux_child_remove_vfork_catchpoint
;
4726 t
->to_insert_exec_catchpoint
= linux_child_insert_exec_catchpoint
;
4727 t
->to_remove_exec_catchpoint
= linux_child_remove_exec_catchpoint
;
4728 t
->to_set_syscall_catchpoint
= linux_child_set_syscall_catchpoint
;
4729 t
->to_pid_to_exec_file
= linux_child_pid_to_exec_file
;
4730 t
->to_post_startup_inferior
= linux_child_post_startup_inferior
;
4731 t
->to_post_attach
= linux_child_post_attach
;
4732 t
->to_follow_fork
= linux_child_follow_fork
;
4733 t
->to_make_corefile_notes
= linux_nat_make_corefile_notes
;
4735 super_xfer_partial
= t
->to_xfer_partial
;
4736 t
->to_xfer_partial
= linux_xfer_partial
;
4738 t
->to_static_tracepoint_markers_by_strid
4739 = linux_child_static_tracepoint_markers_by_strid
;
4745 struct target_ops
*t
;
4747 t
= inf_ptrace_target ();
4748 linux_target_install_ops (t
);
4754 linux_trad_target (CORE_ADDR (*register_u_offset
)(struct gdbarch
*, int, int))
4756 struct target_ops
*t
;
4758 t
= inf_ptrace_trad_target (register_u_offset
);
4759 linux_target_install_ops (t
);
4764 /* target_is_async_p implementation. */
4767 linux_nat_is_async_p (void)
4769 /* NOTE: palves 2008-03-21: We're only async when the user requests
4770 it explicitly with the "set target-async" command.
4771 Someday, linux will always be async. */
4772 return target_async_permitted
;
4775 /* target_can_async_p implementation. */
4778 linux_nat_can_async_p (void)
4780 /* NOTE: palves 2008-03-21: We're only async when the user requests
4781 it explicitly with the "set target-async" command.
4782 Someday, linux will always be async. */
4783 return target_async_permitted
;
4787 linux_nat_supports_non_stop (void)
4792 /* True if we want to support multi-process. To be removed when GDB
4793 supports multi-exec. */
4795 int linux_multi_process
= 1;
4798 linux_nat_supports_multi_process (void)
4800 return linux_multi_process
;
4804 linux_nat_supports_disable_randomization (void)
4806 #ifdef HAVE_PERSONALITY
4813 static int async_terminal_is_ours
= 1;
4815 /* target_terminal_inferior implementation. */
4818 linux_nat_terminal_inferior (void)
4820 if (!target_is_async_p ())
4822 /* Async mode is disabled. */
4823 terminal_inferior ();
4827 terminal_inferior ();
4829 /* Calls to target_terminal_*() are meant to be idempotent. */
4830 if (!async_terminal_is_ours
)
4833 delete_file_handler (input_fd
);
4834 async_terminal_is_ours
= 0;
4838 /* target_terminal_ours implementation. */
4841 linux_nat_terminal_ours (void)
4843 if (!target_is_async_p ())
4845 /* Async mode is disabled. */
4850 /* GDB should never give the terminal to the inferior if the
4851 inferior is running in the background (run&, continue&, etc.),
4852 but claiming it sure should. */
4855 if (async_terminal_is_ours
)
4858 clear_sigint_trap ();
4859 add_file_handler (input_fd
, stdin_event_handler
, 0);
4860 async_terminal_is_ours
= 1;
4863 static void (*async_client_callback
) (enum inferior_event_type event_type
,
4865 static void *async_client_context
;
4867 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4868 so we notice when any child changes state, and notify the
4869 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4870 above to wait for the arrival of a SIGCHLD. */
4873 sigchld_handler (int signo
)
4875 int old_errno
= errno
;
4877 if (debug_linux_nat
)
4878 ui_file_write_async_safe (gdb_stdlog
,
4879 "sigchld\n", sizeof ("sigchld\n") - 1);
4881 if (signo
== SIGCHLD
4882 && linux_nat_event_pipe
[0] != -1)
4883 async_file_mark (); /* Let the event loop know that there are
4884 events to handle. */
4889 /* Callback registered with the target events file descriptor. */
4892 handle_target_event (int error
, gdb_client_data client_data
)
4894 (*async_client_callback
) (INF_REG_EVENT
, async_client_context
);
4897 /* Create/destroy the target events pipe. Returns previous state. */
4900 linux_async_pipe (int enable
)
4902 int previous
= (linux_nat_event_pipe
[0] != -1);
4904 if (previous
!= enable
)
4908 block_child_signals (&prev_mask
);
4912 if (pipe (linux_nat_event_pipe
) == -1)
4913 internal_error (__FILE__
, __LINE__
,
4914 "creating event pipe failed.");
4916 fcntl (linux_nat_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4917 fcntl (linux_nat_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4921 close (linux_nat_event_pipe
[0]);
4922 close (linux_nat_event_pipe
[1]);
4923 linux_nat_event_pipe
[0] = -1;
4924 linux_nat_event_pipe
[1] = -1;
4927 restore_child_signals_mask (&prev_mask
);
4933 /* target_async implementation. */
4936 linux_nat_async (void (*callback
) (enum inferior_event_type event_type
,
4937 void *context
), void *context
)
4939 if (callback
!= NULL
)
4941 async_client_callback
= callback
;
4942 async_client_context
= context
;
4943 if (!linux_async_pipe (1))
4945 add_file_handler (linux_nat_event_pipe
[0],
4946 handle_target_event
, NULL
);
4947 /* There may be pending events to handle. Tell the event loop
4954 async_client_callback
= callback
;
4955 async_client_context
= context
;
4956 delete_file_handler (linux_nat_event_pipe
[0]);
4957 linux_async_pipe (0);
4962 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4966 linux_nat_stop_lwp (struct lwp_info
*lwp
, void *data
)
4970 ptid_t ptid
= lwp
->ptid
;
4972 if (debug_linux_nat
)
4973 fprintf_unfiltered (gdb_stdlog
,
4974 "LNSL: running -> suspending %s\n",
4975 target_pid_to_str (lwp
->ptid
));
4978 if (lwp
->last_resume_kind
== resume_stop
)
4980 if (debug_linux_nat
)
4981 fprintf_unfiltered (gdb_stdlog
,
4982 "linux-nat: already stopping LWP %ld at "
4984 ptid_get_lwp (lwp
->ptid
));
4988 stop_callback (lwp
, NULL
);
4989 lwp
->last_resume_kind
= resume_stop
;
4993 /* Already known to be stopped; do nothing. */
4995 if (debug_linux_nat
)
4997 if (find_thread_ptid (lwp
->ptid
)->stop_requested
)
4998 fprintf_unfiltered (gdb_stdlog
,
4999 "LNSL: already stopped/stop_requested %s\n",
5000 target_pid_to_str (lwp
->ptid
));
5002 fprintf_unfiltered (gdb_stdlog
,
5003 "LNSL: already stopped/no "
5004 "stop_requested yet %s\n",
5005 target_pid_to_str (lwp
->ptid
));
5012 linux_nat_stop (ptid_t ptid
)
5015 iterate_over_lwps (ptid
, linux_nat_stop_lwp
, NULL
);
5017 linux_ops
->to_stop (ptid
);
5021 linux_nat_close (int quitting
)
5023 /* Unregister from the event loop. */
5024 if (linux_nat_is_async_p ())
5025 linux_nat_async (NULL
, 0);
5027 if (linux_ops
->to_close
)
5028 linux_ops
->to_close (quitting
);
5031 /* When requests are passed down from the linux-nat layer to the
5032 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
5033 used. The address space pointer is stored in the inferior object,
5034 but the common code that is passed such ptid can't tell whether
5035 lwpid is a "main" process id or not (it assumes so). We reverse
5036 look up the "main" process id from the lwp here. */
5038 static struct address_space
*
5039 linux_nat_thread_address_space (struct target_ops
*t
, ptid_t ptid
)
5041 struct lwp_info
*lwp
;
5042 struct inferior
*inf
;
5045 pid
= GET_LWP (ptid
);
5046 if (GET_LWP (ptid
) == 0)
5048 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
5050 lwp
= find_lwp_pid (ptid
);
5051 pid
= GET_PID (lwp
->ptid
);
5055 /* A (pid,lwpid,0) ptid. */
5056 pid
= GET_PID (ptid
);
5059 inf
= find_inferior_pid (pid
);
5060 gdb_assert (inf
!= NULL
);
5064 /* Return the cached value of the processor core for thread PTID. */
5067 linux_nat_core_of_thread (struct target_ops
*ops
, ptid_t ptid
)
5069 struct lwp_info
*info
= find_lwp_pid (ptid
);
5077 linux_nat_add_target (struct target_ops
*t
)
5079 /* Save the provided single-threaded target. We save this in a separate
5080 variable because another target we've inherited from (e.g. inf-ptrace)
5081 may have saved a pointer to T; we want to use it for the final
5082 process stratum target. */
5083 linux_ops_saved
= *t
;
5084 linux_ops
= &linux_ops_saved
;
5086 /* Override some methods for multithreading. */
5087 t
->to_create_inferior
= linux_nat_create_inferior
;
5088 t
->to_attach
= linux_nat_attach
;
5089 t
->to_detach
= linux_nat_detach
;
5090 t
->to_resume
= linux_nat_resume
;
5091 t
->to_wait
= linux_nat_wait
;
5092 t
->to_pass_signals
= linux_nat_pass_signals
;
5093 t
->to_xfer_partial
= linux_nat_xfer_partial
;
5094 t
->to_kill
= linux_nat_kill
;
5095 t
->to_mourn_inferior
= linux_nat_mourn_inferior
;
5096 t
->to_thread_alive
= linux_nat_thread_alive
;
5097 t
->to_pid_to_str
= linux_nat_pid_to_str
;
5098 t
->to_thread_name
= linux_nat_thread_name
;
5099 t
->to_has_thread_control
= tc_schedlock
;
5100 t
->to_thread_address_space
= linux_nat_thread_address_space
;
5101 t
->to_stopped_by_watchpoint
= linux_nat_stopped_by_watchpoint
;
5102 t
->to_stopped_data_address
= linux_nat_stopped_data_address
;
5104 t
->to_can_async_p
= linux_nat_can_async_p
;
5105 t
->to_is_async_p
= linux_nat_is_async_p
;
5106 t
->to_supports_non_stop
= linux_nat_supports_non_stop
;
5107 t
->to_async
= linux_nat_async
;
5108 t
->to_terminal_inferior
= linux_nat_terminal_inferior
;
5109 t
->to_terminal_ours
= linux_nat_terminal_ours
;
5110 t
->to_close
= linux_nat_close
;
5112 /* Methods for non-stop support. */
5113 t
->to_stop
= linux_nat_stop
;
5115 t
->to_supports_multi_process
= linux_nat_supports_multi_process
;
5117 t
->to_supports_disable_randomization
5118 = linux_nat_supports_disable_randomization
;
5120 t
->to_core_of_thread
= linux_nat_core_of_thread
;
5122 /* We don't change the stratum; this target will sit at
5123 process_stratum and thread_db will set at thread_stratum. This
5124 is a little strange, since this is a multi-threaded-capable
5125 target, but we want to be on the stack below thread_db, and we
5126 also want to be used for single-threaded processes. */
5131 /* Register a method to call whenever a new thread is attached. */
5133 linux_nat_set_new_thread (struct target_ops
*t
,
5134 void (*new_thread
) (struct lwp_info
*))
5136 /* Save the pointer. We only support a single registered instance
5137 of the GNU/Linux native target, so we do not need to map this to
5139 linux_nat_new_thread
= new_thread
;
5142 /* Register a method that converts a siginfo object between the layout
5143 that ptrace returns, and the layout in the architecture of the
5146 linux_nat_set_siginfo_fixup (struct target_ops
*t
,
5147 int (*siginfo_fixup
) (siginfo_t
*,
5151 /* Save the pointer. */
5152 linux_nat_siginfo_fixup
= siginfo_fixup
;
5155 /* Register a method to call prior to resuming a thread. */
5158 linux_nat_set_prepare_to_resume (struct target_ops
*t
,
5159 void (*prepare_to_resume
) (struct lwp_info
*))
5161 /* Save the pointer. */
5162 linux_nat_prepare_to_resume
= prepare_to_resume
;
5165 /* See linux-nat.h. */
5168 linux_nat_get_siginfo (ptid_t ptid
, siginfo_t
*siginfo
)
5172 pid
= GET_LWP (ptid
);
5174 pid
= GET_PID (ptid
);
5177 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, siginfo
);
5180 memset (siginfo
, 0, sizeof (*siginfo
));
5186 /* Provide a prototype to silence -Wmissing-prototypes. */
5187 extern initialize_file_ftype _initialize_linux_nat
;
5190 _initialize_linux_nat (void)
5192 add_setshow_zinteger_cmd ("lin-lwp", class_maintenance
,
5193 &debug_linux_nat
, _("\
5194 Set debugging of GNU/Linux lwp module."), _("\
5195 Show debugging of GNU/Linux lwp module."), _("\
5196 Enables printf debugging output."),
5198 show_debug_linux_nat
,
5199 &setdebuglist
, &showdebuglist
);
5201 /* Save this mask as the default. */
5202 sigprocmask (SIG_SETMASK
, NULL
, &normal_mask
);
5204 /* Install a SIGCHLD handler. */
5205 sigchld_action
.sa_handler
= sigchld_handler
;
5206 sigemptyset (&sigchld_action
.sa_mask
);
5207 sigchld_action
.sa_flags
= SA_RESTART
;
5209 /* Make it the default. */
5210 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
5212 /* Make sure we don't block SIGCHLD during a sigsuspend. */
5213 sigprocmask (SIG_SETMASK
, NULL
, &suspend_mask
);
5214 sigdelset (&suspend_mask
, SIGCHLD
);
5216 sigemptyset (&blocked_mask
);
5220 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
5221 the GNU/Linux Threads library and therefore doesn't really belong
5224 /* Read variable NAME in the target and return its value if found.
5225 Otherwise return zero. It is assumed that the type of the variable
5229 get_signo (const char *name
)
5231 struct minimal_symbol
*ms
;
5234 ms
= lookup_minimal_symbol (name
, NULL
, NULL
);
5238 if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms
), (gdb_byte
*) &signo
,
5239 sizeof (signo
)) != 0)
5245 /* Return the set of signals used by the threads library in *SET. */
5248 lin_thread_get_thread_signals (sigset_t
*set
)
5250 struct sigaction action
;
5251 int restart
, cancel
;
5253 sigemptyset (&blocked_mask
);
5256 restart
= get_signo ("__pthread_sig_restart");
5257 cancel
= get_signo ("__pthread_sig_cancel");
5259 /* LinuxThreads normally uses the first two RT signals, but in some legacy
5260 cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
5261 not provide any way for the debugger to query the signal numbers -
5262 fortunately they don't change! */
5265 restart
= __SIGRTMIN
;
5268 cancel
= __SIGRTMIN
+ 1;
5270 sigaddset (set
, restart
);
5271 sigaddset (set
, cancel
);
5273 /* The GNU/Linux Threads library makes terminating threads send a
5274 special "cancel" signal instead of SIGCHLD. Make sure we catch
5275 those (to prevent them from terminating GDB itself, which is
5276 likely to be their default action) and treat them the same way as
5279 action
.sa_handler
= sigchld_handler
;
5280 sigemptyset (&action
.sa_mask
);
5281 action
.sa_flags
= SA_RESTART
;
5282 sigaction (cancel
, &action
, NULL
);
5284 /* We block the "cancel" signal throughout this code ... */
5285 sigaddset (&blocked_mask
, cancel
);
5286 sigprocmask (SIG_BLOCK
, &blocked_mask
, NULL
);
5288 /* ... except during a sigsuspend. */
5289 sigdelset (&suspend_mask
, cancel
);