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-ptrace.h"
41 #include <sys/param.h> /* for MAXPATHLEN */
42 #include <sys/procfs.h> /* for elf_gregset etc. */
43 #include "elf-bfd.h" /* for elfcore_write_* */
44 #include "gregset.h" /* for gregset */
45 #include "gdbcore.h" /* for get_exec_file */
46 #include <ctype.h> /* for isdigit */
47 #include "gdbthread.h" /* for struct thread_info etc. */
48 #include "gdb_stat.h" /* for struct stat */
49 #include <fcntl.h> /* for O_RDONLY */
51 #include "event-loop.h"
52 #include "event-top.h"
54 #include <sys/types.h>
55 #include "gdb_dirent.h"
56 #include "xml-support.h"
60 #include "linux-osdata.h"
61 #include "linux-tdep.h"
65 #define SPUFS_MAGIC 0x23c9b64e
68 #ifdef HAVE_PERSONALITY
69 # include <sys/personality.h>
70 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
71 # define ADDR_NO_RANDOMIZE 0x0040000
73 #endif /* HAVE_PERSONALITY */
75 /* This comment documents high-level logic of this file.
77 Waiting for events in sync mode
78 ===============================
80 When waiting for an event in a specific thread, we just use waitpid, passing
81 the specific pid, and not passing WNOHANG.
83 When waiting for an event in all threads, waitpid is not quite good. Prior to
84 version 2.4, Linux can either wait for event in main thread, or in secondary
85 threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might
86 miss an event. The solution is to use non-blocking waitpid, together with
87 sigsuspend. First, we use non-blocking waitpid to get an event in the main
88 process, if any. Second, we use non-blocking waitpid with the __WCLONED
89 flag to check for events in cloned processes. If nothing is found, we use
90 sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something
91 happened to a child process -- and SIGCHLD will be delivered both for events
92 in main debugged process and in cloned processes. As soon as we know there's
93 an event, we get back to calling nonblocking waitpid with and without
96 Note that SIGCHLD should be blocked between waitpid and sigsuspend calls,
97 so that we don't miss a signal. If SIGCHLD arrives in between, when it's
98 blocked, the signal becomes pending and sigsuspend immediately
99 notices it and returns.
101 Waiting for events in async mode
102 ================================
104 In async mode, GDB should always be ready to handle both user input
105 and target events, so neither blocking waitpid nor sigsuspend are
106 viable options. Instead, we should asynchronously notify the GDB main
107 event loop whenever there's an unprocessed event from the target. We
108 detect asynchronous target events by handling SIGCHLD signals. To
109 notify the event loop about target events, the self-pipe trick is used
110 --- a pipe is registered as waitable event source in the event loop,
111 the event loop select/poll's on the read end of this pipe (as well on
112 other event sources, e.g., stdin), and the SIGCHLD handler writes a
113 byte to this pipe. This is more portable than relying on
114 pselect/ppoll, since on kernels that lack those syscalls, libc
115 emulates them with select/poll+sigprocmask, and that is racy
116 (a.k.a. plain broken).
118 Obviously, if we fail to notify the event loop if there's a target
119 event, it's bad. OTOH, if we notify the event loop when there's no
120 event from the target, linux_nat_wait will detect that there's no real
121 event to report, and return event of type TARGET_WAITKIND_IGNORE.
122 This is mostly harmless, but it will waste time and is better avoided.
124 The main design point is that every time GDB is outside linux-nat.c,
125 we have a SIGCHLD handler installed that is called when something
126 happens to the target and notifies the GDB event loop. Whenever GDB
127 core decides to handle the event, and calls into linux-nat.c, we
128 process things as in sync mode, except that the we never block in
131 While processing an event, we may end up momentarily blocked in
132 waitpid calls. Those waitpid calls, while blocking, are guarantied to
133 return quickly. E.g., in all-stop mode, before reporting to the core
134 that an LWP hit a breakpoint, all LWPs are stopped by sending them
135 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
136 Note that this is different from blocking indefinitely waiting for the
137 next event --- here, we're already handling an event.
142 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
143 signal is not entirely significant; we just need for a signal to be delivered,
144 so that we can intercept it. SIGSTOP's advantage is that it can not be
145 blocked. A disadvantage is that it is not a real-time signal, so it can only
146 be queued once; we do not keep track of other sources of SIGSTOP.
148 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
149 use them, because they have special behavior when the signal is generated -
150 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
151 kills the entire thread group.
153 A delivered SIGSTOP would stop the entire thread group, not just the thread we
154 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
155 cancel it (by PTRACE_CONT without passing SIGSTOP).
157 We could use a real-time signal instead. This would solve those problems; we
158 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
159 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
160 generates it, and there are races with trying to find a signal that is not
164 #define O_LARGEFILE 0
167 /* Unlike other extended result codes, WSTOPSIG (status) on
168 PTRACE_O_TRACESYSGOOD syscall events doesn't return SIGTRAP, but
169 instead SIGTRAP with bit 7 set. */
170 #define SYSCALL_SIGTRAP (SIGTRAP | 0x80)
172 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
173 the use of the multi-threaded target. */
174 static struct target_ops
*linux_ops
;
175 static struct target_ops linux_ops_saved
;
177 /* The method to call, if any, when a new thread is attached. */
178 static void (*linux_nat_new_thread
) (struct lwp_info
*);
180 /* Hook to call prior to resuming a thread. */
181 static void (*linux_nat_prepare_to_resume
) (struct lwp_info
*);
183 /* The method to call, if any, when the siginfo object needs to be
184 converted between the layout returned by ptrace, and the layout in
185 the architecture of the inferior. */
186 static int (*linux_nat_siginfo_fixup
) (struct siginfo
*,
190 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
191 Called by our to_xfer_partial. */
192 static LONGEST (*super_xfer_partial
) (struct target_ops
*,
194 const char *, gdb_byte
*,
198 static int debug_linux_nat
;
200 show_debug_linux_nat (struct ui_file
*file
, int from_tty
,
201 struct cmd_list_element
*c
, const char *value
)
203 fprintf_filtered (file
, _("Debugging of GNU/Linux lwp module is %s.\n"),
207 struct simple_pid_list
211 struct simple_pid_list
*next
;
213 struct simple_pid_list
*stopped_pids
;
215 /* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACEFORK
216 can not be used, 1 if it can. */
218 static int linux_supports_tracefork_flag
= -1;
220 /* This variable is a tri-state flag: -1 for unknown, 0 if
221 PTRACE_O_TRACESYSGOOD can not be used, 1 if it can. */
223 static int linux_supports_tracesysgood_flag
= -1;
225 /* If we have PTRACE_O_TRACEFORK, this flag indicates whether we also have
226 PTRACE_O_TRACEVFORKDONE. */
228 static int linux_supports_tracevforkdone_flag
= -1;
230 /* Stores the current used ptrace() options. */
231 static int current_ptrace_options
= 0;
233 /* Async mode support. */
235 /* The read/write ends of the pipe registered as waitable file in the
237 static int linux_nat_event_pipe
[2] = { -1, -1 };
239 /* Flush the event pipe. */
242 async_file_flush (void)
249 ret
= read (linux_nat_event_pipe
[0], &buf
, 1);
251 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
254 /* Put something (anything, doesn't matter what, or how much) in event
255 pipe, so that the select/poll in the event-loop realizes we have
256 something to process. */
259 async_file_mark (void)
263 /* It doesn't really matter what the pipe contains, as long we end
264 up with something in it. Might as well flush the previous
270 ret
= write (linux_nat_event_pipe
[1], "+", 1);
272 while (ret
== -1 && errno
== EINTR
);
274 /* Ignore EAGAIN. If the pipe is full, the event loop will already
275 be awakened anyway. */
278 static void linux_nat_async (void (*callback
)
279 (enum inferior_event_type event_type
,
282 static int kill_lwp (int lwpid
, int signo
);
284 static int stop_callback (struct lwp_info
*lp
, void *data
);
286 static void block_child_signals (sigset_t
*prev_mask
);
287 static void restore_child_signals_mask (sigset_t
*prev_mask
);
290 static struct lwp_info
*add_lwp (ptid_t ptid
);
291 static void purge_lwp_list (int pid
);
292 static void delete_lwp (ptid_t ptid
);
293 static struct lwp_info
*find_lwp_pid (ptid_t ptid
);
296 /* Trivial list manipulation functions to keep track of a list of
297 new stopped processes. */
299 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
301 struct simple_pid_list
*new_pid
= xmalloc (sizeof (struct simple_pid_list
));
304 new_pid
->status
= status
;
305 new_pid
->next
= *listp
;
310 in_pid_list_p (struct simple_pid_list
*list
, int pid
)
312 struct simple_pid_list
*p
;
314 for (p
= list
; p
!= NULL
; p
= p
->next
)
321 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *statusp
)
323 struct simple_pid_list
**p
;
325 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
326 if ((*p
)->pid
== pid
)
328 struct simple_pid_list
*next
= (*p
)->next
;
330 *statusp
= (*p
)->status
;
339 /* A helper function for linux_test_for_tracefork, called after fork (). */
342 linux_tracefork_child (void)
344 ptrace (PTRACE_TRACEME
, 0, 0, 0);
345 kill (getpid (), SIGSTOP
);
350 /* Wrapper function for waitpid which handles EINTR. */
353 my_waitpid (int pid
, int *statusp
, int flags
)
359 ret
= waitpid (pid
, statusp
, flags
);
361 while (ret
== -1 && errno
== EINTR
);
366 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events.
368 First, we try to enable fork tracing on ORIGINAL_PID. If this fails,
369 we know that the feature is not available. This may change the tracing
370 options for ORIGINAL_PID, but we'll be setting them shortly anyway.
372 However, if it succeeds, we don't know for sure that the feature is
373 available; old versions of PTRACE_SETOPTIONS ignored unknown options. We
374 create a child process, attach to it, use PTRACE_SETOPTIONS to enable
375 fork tracing, and let it fork. If the process exits, we assume that we
376 can't use TRACEFORK; if we get the fork notification, and we can extract
377 the new child's PID, then we assume that we can. */
380 linux_test_for_tracefork (int original_pid
)
382 int child_pid
, ret
, status
;
386 /* We don't want those ptrace calls to be interrupted. */
387 block_child_signals (&prev_mask
);
389 linux_supports_tracefork_flag
= 0;
390 linux_supports_tracevforkdone_flag
= 0;
392 ret
= ptrace (PTRACE_SETOPTIONS
, original_pid
, 0, PTRACE_O_TRACEFORK
);
395 restore_child_signals_mask (&prev_mask
);
401 perror_with_name (("fork"));
404 linux_tracefork_child ();
406 ret
= my_waitpid (child_pid
, &status
, 0);
408 perror_with_name (("waitpid"));
409 else if (ret
!= child_pid
)
410 error (_("linux_test_for_tracefork: waitpid: unexpected result %d."), ret
);
411 if (! WIFSTOPPED (status
))
412 error (_("linux_test_for_tracefork: waitpid: unexpected status %d."),
415 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0, PTRACE_O_TRACEFORK
);
418 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
421 warning (_("linux_test_for_tracefork: failed to kill child"));
422 restore_child_signals_mask (&prev_mask
);
426 ret
= my_waitpid (child_pid
, &status
, 0);
427 if (ret
!= child_pid
)
428 warning (_("linux_test_for_tracefork: failed "
429 "to wait for killed child"));
430 else if (!WIFSIGNALED (status
))
431 warning (_("linux_test_for_tracefork: unexpected "
432 "wait status 0x%x from killed child"), status
);
434 restore_child_signals_mask (&prev_mask
);
438 /* Check whether PTRACE_O_TRACEVFORKDONE is available. */
439 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0,
440 PTRACE_O_TRACEFORK
| PTRACE_O_TRACEVFORKDONE
);
441 linux_supports_tracevforkdone_flag
= (ret
== 0);
443 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
445 warning (_("linux_test_for_tracefork: failed to resume child"));
447 ret
= my_waitpid (child_pid
, &status
, 0);
449 if (ret
== child_pid
&& WIFSTOPPED (status
)
450 && status
>> 16 == PTRACE_EVENT_FORK
)
453 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
454 if (ret
== 0 && second_pid
!= 0)
458 linux_supports_tracefork_flag
= 1;
459 my_waitpid (second_pid
, &second_status
, 0);
460 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
462 warning (_("linux_test_for_tracefork: "
463 "failed to kill second child"));
464 my_waitpid (second_pid
, &status
, 0);
468 warning (_("linux_test_for_tracefork: unexpected result from waitpid "
469 "(%d, status 0x%x)"), ret
, status
);
471 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
473 warning (_("linux_test_for_tracefork: failed to kill child"));
474 my_waitpid (child_pid
, &status
, 0);
476 restore_child_signals_mask (&prev_mask
);
479 /* Determine if PTRACE_O_TRACESYSGOOD can be used to follow syscalls.
481 We try to enable syscall tracing on ORIGINAL_PID. If this fails,
482 we know that the feature is not available. This may change the tracing
483 options for ORIGINAL_PID, but we'll be setting them shortly anyway. */
486 linux_test_for_tracesysgood (int original_pid
)
491 /* We don't want those ptrace calls to be interrupted. */
492 block_child_signals (&prev_mask
);
494 linux_supports_tracesysgood_flag
= 0;
496 ret
= ptrace (PTRACE_SETOPTIONS
, original_pid
, 0, PTRACE_O_TRACESYSGOOD
);
500 linux_supports_tracesysgood_flag
= 1;
502 restore_child_signals_mask (&prev_mask
);
505 /* Determine wether we support PTRACE_O_TRACESYSGOOD option available.
506 This function also sets linux_supports_tracesysgood_flag. */
509 linux_supports_tracesysgood (int pid
)
511 if (linux_supports_tracesysgood_flag
== -1)
512 linux_test_for_tracesysgood (pid
);
513 return linux_supports_tracesysgood_flag
;
516 /* Return non-zero iff we have tracefork functionality available.
517 This function also sets linux_supports_tracefork_flag. */
520 linux_supports_tracefork (int pid
)
522 if (linux_supports_tracefork_flag
== -1)
523 linux_test_for_tracefork (pid
);
524 return linux_supports_tracefork_flag
;
528 linux_supports_tracevforkdone (int pid
)
530 if (linux_supports_tracefork_flag
== -1)
531 linux_test_for_tracefork (pid
);
532 return linux_supports_tracevforkdone_flag
;
536 linux_enable_tracesysgood (ptid_t ptid
)
538 int pid
= ptid_get_lwp (ptid
);
541 pid
= ptid_get_pid (ptid
);
543 if (linux_supports_tracesysgood (pid
) == 0)
546 current_ptrace_options
|= PTRACE_O_TRACESYSGOOD
;
548 ptrace (PTRACE_SETOPTIONS
, pid
, 0, current_ptrace_options
);
553 linux_enable_event_reporting (ptid_t ptid
)
555 int pid
= ptid_get_lwp (ptid
);
558 pid
= ptid_get_pid (ptid
);
560 if (! linux_supports_tracefork (pid
))
563 current_ptrace_options
|= PTRACE_O_TRACEFORK
| PTRACE_O_TRACEVFORK
564 | PTRACE_O_TRACEEXEC
| PTRACE_O_TRACECLONE
;
566 if (linux_supports_tracevforkdone (pid
))
567 current_ptrace_options
|= PTRACE_O_TRACEVFORKDONE
;
569 /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support
570 read-only process state. */
572 ptrace (PTRACE_SETOPTIONS
, pid
, 0, current_ptrace_options
);
576 linux_child_post_attach (int pid
)
578 linux_enable_event_reporting (pid_to_ptid (pid
));
579 linux_enable_tracesysgood (pid_to_ptid (pid
));
583 linux_child_post_startup_inferior (ptid_t ptid
)
585 linux_enable_event_reporting (ptid
);
586 linux_enable_tracesysgood (ptid
);
589 /* Return the number of known LWPs in the tgid given by PID. */
597 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
598 if (ptid_get_pid (lp
->ptid
) == pid
)
604 /* Call delete_lwp with prototype compatible for make_cleanup. */
607 delete_lwp_cleanup (void *lp_voidp
)
609 struct lwp_info
*lp
= lp_voidp
;
611 delete_lwp (lp
->ptid
);
615 linux_child_follow_fork (struct target_ops
*ops
, int follow_child
)
619 int parent_pid
, child_pid
;
621 block_child_signals (&prev_mask
);
623 has_vforked
= (inferior_thread ()->pending_follow
.kind
624 == TARGET_WAITKIND_VFORKED
);
625 parent_pid
= ptid_get_lwp (inferior_ptid
);
627 parent_pid
= ptid_get_pid (inferior_ptid
);
628 child_pid
= PIDGET (inferior_thread ()->pending_follow
.value
.related_pid
);
631 linux_enable_event_reporting (pid_to_ptid (child_pid
));
634 && !non_stop
/* Non-stop always resumes both branches. */
635 && (!target_is_async_p () || sync_execution
)
636 && !(follow_child
|| detach_fork
|| sched_multi
))
638 /* The parent stays blocked inside the vfork syscall until the
639 child execs or exits. If we don't let the child run, then
640 the parent stays blocked. If we're telling the parent to run
641 in the foreground, the user will not be able to ctrl-c to get
642 back the terminal, effectively hanging the debug session. */
643 fprintf_filtered (gdb_stderr
, _("\
644 Can not resume the parent process over vfork in the foreground while\n\
645 holding the child stopped. Try \"set detach-on-fork\" or \
646 \"set schedule-multiple\".\n"));
647 /* FIXME output string > 80 columns. */
653 struct lwp_info
*child_lp
= NULL
;
655 /* We're already attached to the parent, by default. */
657 /* Detach new forked process? */
660 struct cleanup
*old_chain
;
662 /* Before detaching from the child, remove all breakpoints
663 from it. If we forked, then this has already been taken
664 care of by infrun.c. If we vforked however, any
665 breakpoint inserted in the parent is visible in the
666 child, even those added while stopped in a vfork
667 catchpoint. This will remove the breakpoints from the
668 parent also, but they'll be reinserted below. */
671 /* keep breakpoints list in sync. */
672 remove_breakpoints_pid (GET_PID (inferior_ptid
));
675 if (info_verbose
|| debug_linux_nat
)
677 target_terminal_ours ();
678 fprintf_filtered (gdb_stdlog
,
679 "Detaching after fork from "
680 "child process %d.\n",
684 old_chain
= save_inferior_ptid ();
685 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
687 child_lp
= add_lwp (inferior_ptid
);
688 child_lp
->stopped
= 1;
689 child_lp
->last_resume_kind
= resume_stop
;
690 make_cleanup (delete_lwp_cleanup
, child_lp
);
692 /* CHILD_LP has new PID, therefore linux_nat_new_thread is not called for it.
693 See i386_inferior_data_get for the Linux kernel specifics.
694 Ensure linux_nat_prepare_to_resume will reset the hardware debug
695 registers. It is done by the linux_nat_new_thread call, which is
696 being skipped in add_lwp above for the first lwp of a pid. */
697 gdb_assert (num_lwps (GET_PID (child_lp
->ptid
)) == 1);
698 if (linux_nat_new_thread
!= NULL
)
699 linux_nat_new_thread (child_lp
);
701 if (linux_nat_prepare_to_resume
!= NULL
)
702 linux_nat_prepare_to_resume (child_lp
);
703 ptrace (PTRACE_DETACH
, child_pid
, 0, 0);
705 do_cleanups (old_chain
);
709 struct inferior
*parent_inf
, *child_inf
;
710 struct cleanup
*old_chain
;
712 /* Add process to GDB's tables. */
713 child_inf
= add_inferior (child_pid
);
715 parent_inf
= current_inferior ();
716 child_inf
->attach_flag
= parent_inf
->attach_flag
;
717 copy_terminal_info (child_inf
, parent_inf
);
719 old_chain
= save_inferior_ptid ();
720 save_current_program_space ();
722 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
723 add_thread (inferior_ptid
);
724 child_lp
= add_lwp (inferior_ptid
);
725 child_lp
->stopped
= 1;
726 child_lp
->last_resume_kind
= resume_stop
;
727 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
729 /* If this is a vfork child, then the address-space is
730 shared with the parent. */
733 child_inf
->pspace
= parent_inf
->pspace
;
734 child_inf
->aspace
= parent_inf
->aspace
;
736 /* The parent will be frozen until the child is done
737 with the shared region. Keep track of the
739 child_inf
->vfork_parent
= parent_inf
;
740 child_inf
->pending_detach
= 0;
741 parent_inf
->vfork_child
= child_inf
;
742 parent_inf
->pending_detach
= 0;
746 child_inf
->aspace
= new_address_space ();
747 child_inf
->pspace
= add_program_space (child_inf
->aspace
);
748 child_inf
->removable
= 1;
749 set_current_program_space (child_inf
->pspace
);
750 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
752 /* Let the shared library layer (solib-svr4) learn about
753 this new process, relocate the cloned exec, pull in
754 shared libraries, and install the solib event
755 breakpoint. If a "cloned-VM" event was propagated
756 better throughout the core, this wouldn't be
758 solib_create_inferior_hook (0);
761 /* Let the thread_db layer learn about this new process. */
762 check_for_thread_db ();
764 do_cleanups (old_chain
);
769 struct lwp_info
*parent_lp
;
770 struct inferior
*parent_inf
;
772 parent_inf
= current_inferior ();
774 /* If we detached from the child, then we have to be careful
775 to not insert breakpoints in the parent until the child
776 is done with the shared memory region. However, if we're
777 staying attached to the child, then we can and should
778 insert breakpoints, so that we can debug it. A
779 subsequent child exec or exit is enough to know when does
780 the child stops using the parent's address space. */
781 parent_inf
->waiting_for_vfork_done
= detach_fork
;
782 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
784 parent_lp
= find_lwp_pid (pid_to_ptid (parent_pid
));
785 gdb_assert (linux_supports_tracefork_flag
>= 0);
787 if (linux_supports_tracevforkdone (0))
790 fprintf_unfiltered (gdb_stdlog
,
791 "LCFF: waiting for VFORK_DONE on %d\n",
793 parent_lp
->stopped
= 1;
795 /* We'll handle the VFORK_DONE event like any other
796 event, in target_wait. */
800 /* We can't insert breakpoints until the child has
801 finished with the shared memory region. We need to
802 wait until that happens. Ideal would be to just
804 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
805 - waitpid (parent_pid, &status, __WALL);
806 However, most architectures can't handle a syscall
807 being traced on the way out if it wasn't traced on
810 We might also think to loop, continuing the child
811 until it exits or gets a SIGTRAP. One problem is
812 that the child might call ptrace with PTRACE_TRACEME.
814 There's no simple and reliable way to figure out when
815 the vforked child will be done with its copy of the
816 shared memory. We could step it out of the syscall,
817 two instructions, let it go, and then single-step the
818 parent once. When we have hardware single-step, this
819 would work; with software single-step it could still
820 be made to work but we'd have to be able to insert
821 single-step breakpoints in the child, and we'd have
822 to insert -just- the single-step breakpoint in the
823 parent. Very awkward.
825 In the end, the best we can do is to make sure it
826 runs for a little while. Hopefully it will be out of
827 range of any breakpoints we reinsert. Usually this
828 is only the single-step breakpoint at vfork's return
832 fprintf_unfiltered (gdb_stdlog
,
833 "LCFF: no VFORK_DONE "
834 "support, sleeping a bit\n");
838 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
839 and leave it pending. The next linux_nat_resume call
840 will notice a pending event, and bypasses actually
841 resuming the inferior. */
842 parent_lp
->status
= 0;
843 parent_lp
->waitstatus
.kind
= TARGET_WAITKIND_VFORK_DONE
;
844 parent_lp
->stopped
= 1;
846 /* If we're in async mode, need to tell the event loop
847 there's something here to process. */
848 if (target_can_async_p ())
855 struct inferior
*parent_inf
, *child_inf
;
856 struct lwp_info
*child_lp
;
857 struct program_space
*parent_pspace
;
859 if (info_verbose
|| debug_linux_nat
)
861 target_terminal_ours ();
863 fprintf_filtered (gdb_stdlog
,
864 _("Attaching after process %d "
865 "vfork to child process %d.\n"),
866 parent_pid
, child_pid
);
868 fprintf_filtered (gdb_stdlog
,
869 _("Attaching after process %d "
870 "fork to child process %d.\n"),
871 parent_pid
, child_pid
);
874 /* Add the new inferior first, so that the target_detach below
875 doesn't unpush the target. */
877 child_inf
= add_inferior (child_pid
);
879 parent_inf
= current_inferior ();
880 child_inf
->attach_flag
= parent_inf
->attach_flag
;
881 copy_terminal_info (child_inf
, parent_inf
);
883 parent_pspace
= parent_inf
->pspace
;
885 /* If we're vforking, we want to hold on to the parent until the
886 child exits or execs. At child exec or exit time we can
887 remove the old breakpoints from the parent and detach or
888 resume debugging it. Otherwise, detach the parent now; we'll
889 want to reuse it's program/address spaces, but we can't set
890 them to the child before removing breakpoints from the
891 parent, otherwise, the breakpoints module could decide to
892 remove breakpoints from the wrong process (since they'd be
893 assigned to the same address space). */
897 gdb_assert (child_inf
->vfork_parent
== NULL
);
898 gdb_assert (parent_inf
->vfork_child
== NULL
);
899 child_inf
->vfork_parent
= parent_inf
;
900 child_inf
->pending_detach
= 0;
901 parent_inf
->vfork_child
= child_inf
;
902 parent_inf
->pending_detach
= detach_fork
;
903 parent_inf
->waiting_for_vfork_done
= 0;
905 else if (detach_fork
)
906 target_detach (NULL
, 0);
908 /* Note that the detach above makes PARENT_INF dangling. */
910 /* Add the child thread to the appropriate lists, and switch to
911 this new thread, before cloning the program space, and
912 informing the solib layer about this new process. */
914 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
915 add_thread (inferior_ptid
);
916 child_lp
= add_lwp (inferior_ptid
);
917 child_lp
->stopped
= 1;
918 child_lp
->last_resume_kind
= resume_stop
;
920 /* If this is a vfork child, then the address-space is shared
921 with the parent. If we detached from the parent, then we can
922 reuse the parent's program/address spaces. */
923 if (has_vforked
|| detach_fork
)
925 child_inf
->pspace
= parent_pspace
;
926 child_inf
->aspace
= child_inf
->pspace
->aspace
;
930 child_inf
->aspace
= new_address_space ();
931 child_inf
->pspace
= add_program_space (child_inf
->aspace
);
932 child_inf
->removable
= 1;
933 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
934 set_current_program_space (child_inf
->pspace
);
935 clone_program_space (child_inf
->pspace
, parent_pspace
);
937 /* Let the shared library layer (solib-svr4) learn about
938 this new process, relocate the cloned exec, pull in
939 shared libraries, and install the solib event breakpoint.
940 If a "cloned-VM" event was propagated better throughout
941 the core, this wouldn't be required. */
942 solib_create_inferior_hook (0);
945 /* Let the thread_db layer learn about this new process. */
946 check_for_thread_db ();
949 restore_child_signals_mask (&prev_mask
);
955 linux_child_insert_fork_catchpoint (int pid
)
957 return !linux_supports_tracefork (pid
);
961 linux_child_remove_fork_catchpoint (int pid
)
967 linux_child_insert_vfork_catchpoint (int pid
)
969 return !linux_supports_tracefork (pid
);
973 linux_child_remove_vfork_catchpoint (int pid
)
979 linux_child_insert_exec_catchpoint (int pid
)
981 return !linux_supports_tracefork (pid
);
985 linux_child_remove_exec_catchpoint (int pid
)
991 linux_child_set_syscall_catchpoint (int pid
, int needed
, int any_count
,
992 int table_size
, int *table
)
994 if (!linux_supports_tracesysgood (pid
))
997 /* On GNU/Linux, we ignore the arguments. It means that we only
998 enable the syscall catchpoints, but do not disable them.
1000 Also, we do not use the `table' information because we do not
1001 filter system calls here. We let GDB do the logic for us. */
1005 /* On GNU/Linux there are no real LWP's. The closest thing to LWP's
1006 are processes sharing the same VM space. A multi-threaded process
1007 is basically a group of such processes. However, such a grouping
1008 is almost entirely a user-space issue; the kernel doesn't enforce
1009 such a grouping at all (this might change in the future). In
1010 general, we'll rely on the threads library (i.e. the GNU/Linux
1011 Threads library) to provide such a grouping.
1013 It is perfectly well possible to write a multi-threaded application
1014 without the assistance of a threads library, by using the clone
1015 system call directly. This module should be able to give some
1016 rudimentary support for debugging such applications if developers
1017 specify the CLONE_PTRACE flag in the clone system call, and are
1018 using the Linux kernel 2.4 or above.
1020 Note that there are some peculiarities in GNU/Linux that affect
1023 - In general one should specify the __WCLONE flag to waitpid in
1024 order to make it report events for any of the cloned processes
1025 (and leave it out for the initial process). However, if a cloned
1026 process has exited the exit status is only reported if the
1027 __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
1028 we cannot use it since GDB must work on older systems too.
1030 - When a traced, cloned process exits and is waited for by the
1031 debugger, the kernel reassigns it to the original parent and
1032 keeps it around as a "zombie". Somehow, the GNU/Linux Threads
1033 library doesn't notice this, which leads to the "zombie problem":
1034 When debugged a multi-threaded process that spawns a lot of
1035 threads will run out of processes, even if the threads exit,
1036 because the "zombies" stay around. */
1038 /* List of known LWPs. */
1039 struct lwp_info
*lwp_list
;
1042 /* Original signal mask. */
1043 static sigset_t normal_mask
;
1045 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
1046 _initialize_linux_nat. */
1047 static sigset_t suspend_mask
;
1049 /* Signals to block to make that sigsuspend work. */
1050 static sigset_t blocked_mask
;
1052 /* SIGCHLD action. */
1053 struct sigaction sigchld_action
;
1055 /* Block child signals (SIGCHLD and linux threads signals), and store
1056 the previous mask in PREV_MASK. */
1059 block_child_signals (sigset_t
*prev_mask
)
1061 /* Make sure SIGCHLD is blocked. */
1062 if (!sigismember (&blocked_mask
, SIGCHLD
))
1063 sigaddset (&blocked_mask
, SIGCHLD
);
1065 sigprocmask (SIG_BLOCK
, &blocked_mask
, prev_mask
);
1068 /* Restore child signals mask, previously returned by
1069 block_child_signals. */
1072 restore_child_signals_mask (sigset_t
*prev_mask
)
1074 sigprocmask (SIG_SETMASK
, prev_mask
, NULL
);
1077 /* Mask of signals to pass directly to the inferior. */
1078 static sigset_t pass_mask
;
1080 /* Update signals to pass to the inferior. */
1082 linux_nat_pass_signals (int numsigs
, unsigned char *pass_signals
)
1086 sigemptyset (&pass_mask
);
1088 for (signo
= 1; signo
< NSIG
; signo
++)
1090 int target_signo
= target_signal_from_host (signo
);
1091 if (target_signo
< numsigs
&& pass_signals
[target_signo
])
1092 sigaddset (&pass_mask
, signo
);
1098 /* Prototypes for local functions. */
1099 static int stop_wait_callback (struct lwp_info
*lp
, void *data
);
1100 static int linux_thread_alive (ptid_t ptid
);
1101 static char *linux_child_pid_to_exec_file (int pid
);
1104 /* Convert wait status STATUS to a string. Used for printing debug
1108 status_to_str (int status
)
1110 static char buf
[64];
1112 if (WIFSTOPPED (status
))
1114 if (WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
1115 snprintf (buf
, sizeof (buf
), "%s (stopped at syscall)",
1116 strsignal (SIGTRAP
));
1118 snprintf (buf
, sizeof (buf
), "%s (stopped)",
1119 strsignal (WSTOPSIG (status
)));
1121 else if (WIFSIGNALED (status
))
1122 snprintf (buf
, sizeof (buf
), "%s (terminated)",
1123 strsignal (WTERMSIG (status
)));
1125 snprintf (buf
, sizeof (buf
), "%d (exited)", WEXITSTATUS (status
));
1130 /* Destroy and free LP. */
1133 lwp_free (struct lwp_info
*lp
)
1135 xfree (lp
->arch_private
);
1139 /* Remove all LWPs belong to PID from the lwp list. */
1142 purge_lwp_list (int pid
)
1144 struct lwp_info
*lp
, *lpprev
, *lpnext
;
1148 for (lp
= lwp_list
; lp
; lp
= lpnext
)
1152 if (ptid_get_pid (lp
->ptid
) == pid
)
1155 lwp_list
= lp
->next
;
1157 lpprev
->next
= lp
->next
;
1166 /* Add the LWP specified by PID to the list. Return a pointer to the
1167 structure describing the new LWP. The LWP should already be stopped
1168 (with an exception for the very first LWP). */
1170 static struct lwp_info
*
1171 add_lwp (ptid_t ptid
)
1173 struct lwp_info
*lp
;
1175 gdb_assert (is_lwp (ptid
));
1177 lp
= (struct lwp_info
*) xmalloc (sizeof (struct lwp_info
));
1179 memset (lp
, 0, sizeof (struct lwp_info
));
1181 lp
->last_resume_kind
= resume_continue
;
1182 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
1187 lp
->next
= lwp_list
;
1190 /* Let the arch specific bits know about this new thread. Current
1191 clients of this callback take the opportunity to install
1192 watchpoints in the new thread. Don't do this for the first
1193 thread though. If we're spawning a child ("run"), the thread
1194 executes the shell wrapper first, and we shouldn't touch it until
1195 it execs the program we want to debug. For "attach", it'd be
1196 okay to call the callback, but it's not necessary, because
1197 watchpoints can't yet have been inserted into the inferior. */
1198 if (num_lwps (GET_PID (ptid
)) > 1 && linux_nat_new_thread
!= NULL
)
1199 linux_nat_new_thread (lp
);
1204 /* Remove the LWP specified by PID from the list. */
1207 delete_lwp (ptid_t ptid
)
1209 struct lwp_info
*lp
, *lpprev
;
1213 for (lp
= lwp_list
; lp
; lpprev
= lp
, lp
= lp
->next
)
1214 if (ptid_equal (lp
->ptid
, ptid
))
1221 lpprev
->next
= lp
->next
;
1223 lwp_list
= lp
->next
;
1228 /* Return a pointer to the structure describing the LWP corresponding
1229 to PID. If no corresponding LWP could be found, return NULL. */
1231 static struct lwp_info
*
1232 find_lwp_pid (ptid_t ptid
)
1234 struct lwp_info
*lp
;
1238 lwp
= GET_LWP (ptid
);
1240 lwp
= GET_PID (ptid
);
1242 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
1243 if (lwp
== GET_LWP (lp
->ptid
))
1249 /* Call CALLBACK with its second argument set to DATA for every LWP in
1250 the list. If CALLBACK returns 1 for a particular LWP, return a
1251 pointer to the structure describing that LWP immediately.
1252 Otherwise return NULL. */
1255 iterate_over_lwps (ptid_t filter
,
1256 int (*callback
) (struct lwp_info
*, void *),
1259 struct lwp_info
*lp
, *lpnext
;
1261 for (lp
= lwp_list
; lp
; lp
= lpnext
)
1265 if (ptid_match (lp
->ptid
, filter
))
1267 if ((*callback
) (lp
, data
))
1275 /* Iterate like iterate_over_lwps does except when forking-off a child call
1276 CALLBACK with CALLBACK_DATA specifically only for that new child PID. */
1279 linux_nat_iterate_watchpoint_lwps
1280 (linux_nat_iterate_watchpoint_lwps_ftype callback
, void *callback_data
)
1282 int inferior_pid
= ptid_get_pid (inferior_ptid
);
1283 struct inferior
*inf
= current_inferior ();
1285 if (inf
->pid
== inferior_pid
)
1287 /* Iterate all the threads of the current inferior. Without specifying
1288 INFERIOR_PID it would iterate all threads of all inferiors, which is
1289 inappropriate for watchpoints. */
1291 iterate_over_lwps (pid_to_ptid (inferior_pid
), callback
, callback_data
);
1295 /* Detaching a new child PID temporarily present in INFERIOR_PID. */
1297 struct lwp_info
*child_lp
;
1298 struct cleanup
*old_chain
;
1299 pid_t child_pid
= GET_PID (inferior_ptid
);
1300 ptid_t child_ptid
= ptid_build (child_pid
, child_pid
, 0);
1302 gdb_assert (!is_lwp (inferior_ptid
));
1303 gdb_assert (find_lwp_pid (child_ptid
) == NULL
);
1304 child_lp
= add_lwp (child_ptid
);
1305 child_lp
->stopped
= 1;
1306 child_lp
->last_resume_kind
= resume_stop
;
1307 old_chain
= make_cleanup (delete_lwp_cleanup
, child_lp
);
1309 callback (child_lp
, callback_data
);
1311 do_cleanups (old_chain
);
1315 /* Update our internal state when changing from one checkpoint to
1316 another indicated by NEW_PTID. We can only switch single-threaded
1317 applications, so we only create one new LWP, and the previous list
1321 linux_nat_switch_fork (ptid_t new_ptid
)
1323 struct lwp_info
*lp
;
1325 purge_lwp_list (GET_PID (inferior_ptid
));
1327 lp
= add_lwp (new_ptid
);
1330 /* This changes the thread's ptid while preserving the gdb thread
1331 num. Also changes the inferior pid, while preserving the
1333 thread_change_ptid (inferior_ptid
, new_ptid
);
1335 /* We've just told GDB core that the thread changed target id, but,
1336 in fact, it really is a different thread, with different register
1338 registers_changed ();
1341 /* Handle the exit of a single thread LP. */
1344 exit_lwp (struct lwp_info
*lp
)
1346 struct thread_info
*th
= find_thread_ptid (lp
->ptid
);
1350 if (print_thread_events
)
1351 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp
->ptid
));
1353 delete_thread (lp
->ptid
);
1356 delete_lwp (lp
->ptid
);
1359 /* Detect `T (stopped)' in `/proc/PID/status'.
1360 Other states including `T (tracing stop)' are reported as false. */
1363 pid_is_stopped (pid_t pid
)
1369 snprintf (buf
, sizeof (buf
), "/proc/%d/status", (int) pid
);
1370 status_file
= fopen (buf
, "r");
1371 if (status_file
!= NULL
)
1375 while (fgets (buf
, sizeof (buf
), status_file
))
1377 if (strncmp (buf
, "State:", 6) == 0)
1383 if (have_state
&& strstr (buf
, "T (stopped)") != NULL
)
1385 fclose (status_file
);
1390 /* Wait for the LWP specified by LP, which we have just attached to.
1391 Returns a wait status for that LWP, to cache. */
1394 linux_nat_post_attach_wait (ptid_t ptid
, int first
, int *cloned
,
1397 pid_t new_pid
, pid
= GET_LWP (ptid
);
1400 if (pid_is_stopped (pid
))
1402 if (debug_linux_nat
)
1403 fprintf_unfiltered (gdb_stdlog
,
1404 "LNPAW: Attaching to a stopped process\n");
1406 /* The process is definitely stopped. It is in a job control
1407 stop, unless the kernel predates the TASK_STOPPED /
1408 TASK_TRACED distinction, in which case it might be in a
1409 ptrace stop. Make sure it is in a ptrace stop; from there we
1410 can kill it, signal it, et cetera.
1412 First make sure there is a pending SIGSTOP. Since we are
1413 already attached, the process can not transition from stopped
1414 to running without a PTRACE_CONT; so we know this signal will
1415 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1416 probably already in the queue (unless this kernel is old
1417 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1418 is not an RT signal, it can only be queued once. */
1419 kill_lwp (pid
, SIGSTOP
);
1421 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1422 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1423 ptrace (PTRACE_CONT
, pid
, 0, 0);
1426 /* Make sure the initial process is stopped. The user-level threads
1427 layer might want to poke around in the inferior, and that won't
1428 work if things haven't stabilized yet. */
1429 new_pid
= my_waitpid (pid
, &status
, 0);
1430 if (new_pid
== -1 && errno
== ECHILD
)
1433 warning (_("%s is a cloned process"), target_pid_to_str (ptid
));
1435 /* Try again with __WCLONE to check cloned processes. */
1436 new_pid
= my_waitpid (pid
, &status
, __WCLONE
);
1440 gdb_assert (pid
== new_pid
);
1442 if (!WIFSTOPPED (status
))
1444 /* The pid we tried to attach has apparently just exited. */
1445 if (debug_linux_nat
)
1446 fprintf_unfiltered (gdb_stdlog
, "LNPAW: Failed to stop %d: %s",
1447 pid
, status_to_str (status
));
1451 if (WSTOPSIG (status
) != SIGSTOP
)
1454 if (debug_linux_nat
)
1455 fprintf_unfiltered (gdb_stdlog
,
1456 "LNPAW: Received %s after attaching\n",
1457 status_to_str (status
));
1463 /* Attach to the LWP specified by PID. Return 0 if successful, -1 if
1464 the new LWP could not be attached, or 1 if we're already auto
1465 attached to this thread, but haven't processed the
1466 PTRACE_EVENT_CLONE event of its parent thread, so we just ignore
1467 its existance, without considering it an error. */
1470 lin_lwp_attach_lwp (ptid_t ptid
)
1472 struct lwp_info
*lp
;
1476 gdb_assert (is_lwp (ptid
));
1478 block_child_signals (&prev_mask
);
1480 lp
= find_lwp_pid (ptid
);
1481 lwpid
= GET_LWP (ptid
);
1483 /* We assume that we're already attached to any LWP that has an id
1484 equal to the overall process id, and to any LWP that is already
1485 in our list of LWPs. If we're not seeing exit events from threads
1486 and we've had PID wraparound since we last tried to stop all threads,
1487 this assumption might be wrong; fortunately, this is very unlikely
1489 if (lwpid
!= GET_PID (ptid
) && lp
== NULL
)
1491 int status
, cloned
= 0, signalled
= 0;
1493 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) < 0)
1495 if (linux_supports_tracefork_flag
)
1497 /* If we haven't stopped all threads when we get here,
1498 we may have seen a thread listed in thread_db's list,
1499 but not processed the PTRACE_EVENT_CLONE yet. If
1500 that's the case, ignore this new thread, and let
1501 normal event handling discover it later. */
1502 if (in_pid_list_p (stopped_pids
, lwpid
))
1504 /* We've already seen this thread stop, but we
1505 haven't seen the PTRACE_EVENT_CLONE extended
1507 restore_child_signals_mask (&prev_mask
);
1515 /* See if we've got a stop for this new child
1516 pending. If so, we're already attached. */
1517 new_pid
= my_waitpid (lwpid
, &status
, WNOHANG
);
1518 if (new_pid
== -1 && errno
== ECHILD
)
1519 new_pid
= my_waitpid (lwpid
, &status
, __WCLONE
| WNOHANG
);
1522 if (WIFSTOPPED (status
))
1523 add_to_pid_list (&stopped_pids
, lwpid
, status
);
1525 restore_child_signals_mask (&prev_mask
);
1531 /* If we fail to attach to the thread, issue a warning,
1532 but continue. One way this can happen is if thread
1533 creation is interrupted; as of Linux kernel 2.6.19, a
1534 bug may place threads in the thread list and then fail
1536 warning (_("Can't attach %s: %s"), target_pid_to_str (ptid
),
1537 safe_strerror (errno
));
1538 restore_child_signals_mask (&prev_mask
);
1542 if (debug_linux_nat
)
1543 fprintf_unfiltered (gdb_stdlog
,
1544 "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
1545 target_pid_to_str (ptid
));
1547 status
= linux_nat_post_attach_wait (ptid
, 0, &cloned
, &signalled
);
1548 if (!WIFSTOPPED (status
))
1550 restore_child_signals_mask (&prev_mask
);
1554 lp
= add_lwp (ptid
);
1556 lp
->cloned
= cloned
;
1557 lp
->signalled
= signalled
;
1558 if (WSTOPSIG (status
) != SIGSTOP
)
1561 lp
->status
= status
;
1564 target_post_attach (GET_LWP (lp
->ptid
));
1566 if (debug_linux_nat
)
1568 fprintf_unfiltered (gdb_stdlog
,
1569 "LLAL: waitpid %s received %s\n",
1570 target_pid_to_str (ptid
),
1571 status_to_str (status
));
1576 /* We assume that the LWP representing the original process is
1577 already stopped. Mark it as stopped in the data structure
1578 that the GNU/linux ptrace layer uses to keep track of
1579 threads. Note that this won't have already been done since
1580 the main thread will have, we assume, been stopped by an
1581 attach from a different layer. */
1583 lp
= add_lwp (ptid
);
1587 lp
->last_resume_kind
= resume_stop
;
1588 restore_child_signals_mask (&prev_mask
);
1593 linux_nat_create_inferior (struct target_ops
*ops
,
1594 char *exec_file
, char *allargs
, char **env
,
1597 #ifdef HAVE_PERSONALITY
1598 int personality_orig
= 0, personality_set
= 0;
1599 #endif /* HAVE_PERSONALITY */
1601 /* The fork_child mechanism is synchronous and calls target_wait, so
1602 we have to mask the async mode. */
1604 #ifdef HAVE_PERSONALITY
1605 if (disable_randomization
)
1608 personality_orig
= personality (0xffffffff);
1609 if (errno
== 0 && !(personality_orig
& ADDR_NO_RANDOMIZE
))
1611 personality_set
= 1;
1612 personality (personality_orig
| ADDR_NO_RANDOMIZE
);
1614 if (errno
!= 0 || (personality_set
1615 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE
)))
1616 warning (_("Error disabling address space randomization: %s"),
1617 safe_strerror (errno
));
1619 #endif /* HAVE_PERSONALITY */
1621 /* Make sure we report all signals during startup. */
1622 linux_nat_pass_signals (0, NULL
);
1624 linux_ops
->to_create_inferior (ops
, exec_file
, allargs
, env
, from_tty
);
1626 #ifdef HAVE_PERSONALITY
1627 if (personality_set
)
1630 personality (personality_orig
);
1632 warning (_("Error restoring address space randomization: %s"),
1633 safe_strerror (errno
));
1635 #endif /* HAVE_PERSONALITY */
1639 linux_nat_attach (struct target_ops
*ops
, char *args
, int from_tty
)
1641 struct lwp_info
*lp
;
1645 /* Make sure we report all signals during attach. */
1646 linux_nat_pass_signals (0, NULL
);
1648 linux_ops
->to_attach (ops
, args
, from_tty
);
1650 /* The ptrace base target adds the main thread with (pid,0,0)
1651 format. Decorate it with lwp info. */
1652 ptid
= BUILD_LWP (GET_PID (inferior_ptid
), GET_PID (inferior_ptid
));
1653 thread_change_ptid (inferior_ptid
, ptid
);
1655 /* Add the initial process as the first LWP to the list. */
1656 lp
= add_lwp (ptid
);
1658 status
= linux_nat_post_attach_wait (lp
->ptid
, 1, &lp
->cloned
,
1660 if (!WIFSTOPPED (status
))
1662 if (WIFEXITED (status
))
1664 int exit_code
= WEXITSTATUS (status
);
1666 target_terminal_ours ();
1667 target_mourn_inferior ();
1669 error (_("Unable to attach: program exited normally."));
1671 error (_("Unable to attach: program exited with code %d."),
1674 else if (WIFSIGNALED (status
))
1676 enum target_signal signo
;
1678 target_terminal_ours ();
1679 target_mourn_inferior ();
1681 signo
= target_signal_from_host (WTERMSIG (status
));
1682 error (_("Unable to attach: program terminated with signal "
1684 target_signal_to_name (signo
),
1685 target_signal_to_string (signo
));
1688 internal_error (__FILE__
, __LINE__
,
1689 _("unexpected status %d for PID %ld"),
1690 status
, (long) GET_LWP (ptid
));
1695 /* Save the wait status to report later. */
1697 if (debug_linux_nat
)
1698 fprintf_unfiltered (gdb_stdlog
,
1699 "LNA: waitpid %ld, saving status %s\n",
1700 (long) GET_PID (lp
->ptid
), status_to_str (status
));
1702 lp
->status
= status
;
1704 if (target_can_async_p ())
1705 target_async (inferior_event_handler
, 0);
1708 /* Get pending status of LP. */
1710 get_pending_status (struct lwp_info
*lp
, int *status
)
1712 enum target_signal signo
= TARGET_SIGNAL_0
;
1714 /* If we paused threads momentarily, we may have stored pending
1715 events in lp->status or lp->waitstatus (see stop_wait_callback),
1716 and GDB core hasn't seen any signal for those threads.
1717 Otherwise, the last signal reported to the core is found in the
1718 thread object's stop_signal.
1720 There's a corner case that isn't handled here at present. Only
1721 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1722 stop_signal make sense as a real signal to pass to the inferior.
1723 Some catchpoint related events, like
1724 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1725 to TARGET_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1726 those traps are debug API (ptrace in our case) related and
1727 induced; the inferior wouldn't see them if it wasn't being
1728 traced. Hence, we should never pass them to the inferior, even
1729 when set to pass state. Since this corner case isn't handled by
1730 infrun.c when proceeding with a signal, for consistency, neither
1731 do we handle it here (or elsewhere in the file we check for
1732 signal pass state). Normally SIGTRAP isn't set to pass state, so
1733 this is really a corner case. */
1735 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
1736 signo
= TARGET_SIGNAL_0
; /* a pending ptrace event, not a real signal. */
1737 else if (lp
->status
)
1738 signo
= target_signal_from_host (WSTOPSIG (lp
->status
));
1739 else if (non_stop
&& !is_executing (lp
->ptid
))
1741 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1743 signo
= tp
->suspend
.stop_signal
;
1747 struct target_waitstatus last
;
1750 get_last_target_status (&last_ptid
, &last
);
1752 if (GET_LWP (lp
->ptid
) == GET_LWP (last_ptid
))
1754 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1756 signo
= tp
->suspend
.stop_signal
;
1762 if (signo
== TARGET_SIGNAL_0
)
1764 if (debug_linux_nat
)
1765 fprintf_unfiltered (gdb_stdlog
,
1766 "GPT: lwp %s has no pending signal\n",
1767 target_pid_to_str (lp
->ptid
));
1769 else if (!signal_pass_state (signo
))
1771 if (debug_linux_nat
)
1772 fprintf_unfiltered (gdb_stdlog
,
1773 "GPT: lwp %s had signal %s, "
1774 "but it is in no pass state\n",
1775 target_pid_to_str (lp
->ptid
),
1776 target_signal_to_string (signo
));
1780 *status
= W_STOPCODE (target_signal_to_host (signo
));
1782 if (debug_linux_nat
)
1783 fprintf_unfiltered (gdb_stdlog
,
1784 "GPT: lwp %s has pending signal %s\n",
1785 target_pid_to_str (lp
->ptid
),
1786 target_signal_to_string (signo
));
1793 detach_callback (struct lwp_info
*lp
, void *data
)
1795 gdb_assert (lp
->status
== 0 || WIFSTOPPED (lp
->status
));
1797 if (debug_linux_nat
&& lp
->status
)
1798 fprintf_unfiltered (gdb_stdlog
, "DC: Pending %s for %s on detach.\n",
1799 strsignal (WSTOPSIG (lp
->status
)),
1800 target_pid_to_str (lp
->ptid
));
1802 /* If there is a pending SIGSTOP, get rid of it. */
1805 if (debug_linux_nat
)
1806 fprintf_unfiltered (gdb_stdlog
,
1807 "DC: Sending SIGCONT to %s\n",
1808 target_pid_to_str (lp
->ptid
));
1810 kill_lwp (GET_LWP (lp
->ptid
), SIGCONT
);
1814 /* We don't actually detach from the LWP that has an id equal to the
1815 overall process id just yet. */
1816 if (GET_LWP (lp
->ptid
) != GET_PID (lp
->ptid
))
1820 /* Pass on any pending signal for this LWP. */
1821 get_pending_status (lp
, &status
);
1823 if (linux_nat_prepare_to_resume
!= NULL
)
1824 linux_nat_prepare_to_resume (lp
);
1826 if (ptrace (PTRACE_DETACH
, GET_LWP (lp
->ptid
), 0,
1827 WSTOPSIG (status
)) < 0)
1828 error (_("Can't detach %s: %s"), target_pid_to_str (lp
->ptid
),
1829 safe_strerror (errno
));
1831 if (debug_linux_nat
)
1832 fprintf_unfiltered (gdb_stdlog
,
1833 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1834 target_pid_to_str (lp
->ptid
),
1835 strsignal (WSTOPSIG (status
)));
1837 delete_lwp (lp
->ptid
);
1844 linux_nat_detach (struct target_ops
*ops
, char *args
, int from_tty
)
1848 struct lwp_info
*main_lwp
;
1850 pid
= GET_PID (inferior_ptid
);
1852 if (target_can_async_p ())
1853 linux_nat_async (NULL
, 0);
1855 /* Stop all threads before detaching. ptrace requires that the
1856 thread is stopped to sucessfully detach. */
1857 iterate_over_lwps (pid_to_ptid (pid
), stop_callback
, NULL
);
1858 /* ... and wait until all of them have reported back that
1859 they're no longer running. */
1860 iterate_over_lwps (pid_to_ptid (pid
), stop_wait_callback
, NULL
);
1862 iterate_over_lwps (pid_to_ptid (pid
), detach_callback
, NULL
);
1864 /* Only the initial process should be left right now. */
1865 gdb_assert (num_lwps (GET_PID (inferior_ptid
)) == 1);
1867 main_lwp
= find_lwp_pid (pid_to_ptid (pid
));
1869 /* Pass on any pending signal for the last LWP. */
1870 if ((args
== NULL
|| *args
== '\0')
1871 && get_pending_status (main_lwp
, &status
) != -1
1872 && WIFSTOPPED (status
))
1874 /* Put the signal number in ARGS so that inf_ptrace_detach will
1875 pass it along with PTRACE_DETACH. */
1877 sprintf (args
, "%d", (int) WSTOPSIG (status
));
1878 if (debug_linux_nat
)
1879 fprintf_unfiltered (gdb_stdlog
,
1880 "LND: Sending signal %s to %s\n",
1882 target_pid_to_str (main_lwp
->ptid
));
1885 if (linux_nat_prepare_to_resume
!= NULL
)
1886 linux_nat_prepare_to_resume (main_lwp
);
1887 delete_lwp (main_lwp
->ptid
);
1889 if (forks_exist_p ())
1891 /* Multi-fork case. The current inferior_ptid is being detached
1892 from, but there are other viable forks to debug. Detach from
1893 the current fork, and context-switch to the first
1895 linux_fork_detach (args
, from_tty
);
1897 if (non_stop
&& target_can_async_p ())
1898 target_async (inferior_event_handler
, 0);
1901 linux_ops
->to_detach (ops
, args
, from_tty
);
1907 resume_lwp (struct lwp_info
*lp
, int step
)
1911 struct inferior
*inf
= find_inferior_pid (GET_PID (lp
->ptid
));
1913 if (inf
->vfork_child
!= NULL
)
1915 if (debug_linux_nat
)
1916 fprintf_unfiltered (gdb_stdlog
,
1917 "RC: Not resuming %s (vfork parent)\n",
1918 target_pid_to_str (lp
->ptid
));
1920 else if (lp
->status
== 0
1921 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
1923 if (debug_linux_nat
)
1924 fprintf_unfiltered (gdb_stdlog
,
1925 "RC: PTRACE_CONT %s, 0, 0 (resuming sibling)\n",
1926 target_pid_to_str (lp
->ptid
));
1928 if (linux_nat_prepare_to_resume
!= NULL
)
1929 linux_nat_prepare_to_resume (lp
);
1930 linux_ops
->to_resume (linux_ops
,
1931 pid_to_ptid (GET_LWP (lp
->ptid
)),
1932 step
, TARGET_SIGNAL_0
);
1935 memset (&lp
->siginfo
, 0, sizeof (lp
->siginfo
));
1936 lp
->stopped_by_watchpoint
= 0;
1940 if (debug_linux_nat
)
1941 fprintf_unfiltered (gdb_stdlog
,
1942 "RC: Not resuming sibling %s (has pending)\n",
1943 target_pid_to_str (lp
->ptid
));
1948 if (debug_linux_nat
)
1949 fprintf_unfiltered (gdb_stdlog
,
1950 "RC: Not resuming sibling %s (not stopped)\n",
1951 target_pid_to_str (lp
->ptid
));
1956 resume_callback (struct lwp_info
*lp
, void *data
)
1963 resume_clear_callback (struct lwp_info
*lp
, void *data
)
1966 lp
->last_resume_kind
= resume_stop
;
1971 resume_set_callback (struct lwp_info
*lp
, void *data
)
1974 lp
->last_resume_kind
= resume_continue
;
1979 linux_nat_resume (struct target_ops
*ops
,
1980 ptid_t ptid
, int step
, enum target_signal signo
)
1983 struct lwp_info
*lp
;
1986 if (debug_linux_nat
)
1987 fprintf_unfiltered (gdb_stdlog
,
1988 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1989 step
? "step" : "resume",
1990 target_pid_to_str (ptid
),
1991 (signo
!= TARGET_SIGNAL_0
1992 ? strsignal (target_signal_to_host (signo
)) : "0"),
1993 target_pid_to_str (inferior_ptid
));
1995 block_child_signals (&prev_mask
);
1997 /* A specific PTID means `step only this process id'. */
1998 resume_many
= (ptid_equal (minus_one_ptid
, ptid
)
1999 || ptid_is_pid (ptid
));
2001 /* Mark the lwps we're resuming as resumed. */
2002 iterate_over_lwps (ptid
, resume_set_callback
, NULL
);
2004 /* See if it's the current inferior that should be handled
2007 lp
= find_lwp_pid (inferior_ptid
);
2009 lp
= find_lwp_pid (ptid
);
2010 gdb_assert (lp
!= NULL
);
2012 /* Remember if we're stepping. */
2014 lp
->last_resume_kind
= step
? resume_step
: resume_continue
;
2016 /* If we have a pending wait status for this thread, there is no
2017 point in resuming the process. But first make sure that
2018 linux_nat_wait won't preemptively handle the event - we
2019 should never take this short-circuit if we are going to
2020 leave LP running, since we have skipped resuming all the
2021 other threads. This bit of code needs to be synchronized
2022 with linux_nat_wait. */
2024 if (lp
->status
&& WIFSTOPPED (lp
->status
))
2027 && WSTOPSIG (lp
->status
)
2028 && sigismember (&pass_mask
, WSTOPSIG (lp
->status
)))
2030 if (debug_linux_nat
)
2031 fprintf_unfiltered (gdb_stdlog
,
2032 "LLR: Not short circuiting for ignored "
2033 "status 0x%x\n", lp
->status
);
2035 /* FIXME: What should we do if we are supposed to continue
2036 this thread with a signal? */
2037 gdb_assert (signo
== TARGET_SIGNAL_0
);
2038 signo
= target_signal_from_host (WSTOPSIG (lp
->status
));
2043 if (lp
->status
|| lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
2045 /* FIXME: What should we do if we are supposed to continue
2046 this thread with a signal? */
2047 gdb_assert (signo
== TARGET_SIGNAL_0
);
2049 if (debug_linux_nat
)
2050 fprintf_unfiltered (gdb_stdlog
,
2051 "LLR: Short circuiting for status 0x%x\n",
2054 restore_child_signals_mask (&prev_mask
);
2055 if (target_can_async_p ())
2057 target_async (inferior_event_handler
, 0);
2058 /* Tell the event loop we have something to process. */
2064 /* Mark LWP as not stopped to prevent it from being continued by
2069 iterate_over_lwps (ptid
, resume_callback
, NULL
);
2071 /* Convert to something the lower layer understands. */
2072 ptid
= pid_to_ptid (GET_LWP (lp
->ptid
));
2074 if (linux_nat_prepare_to_resume
!= NULL
)
2075 linux_nat_prepare_to_resume (lp
);
2076 linux_ops
->to_resume (linux_ops
, ptid
, step
, signo
);
2077 memset (&lp
->siginfo
, 0, sizeof (lp
->siginfo
));
2078 lp
->stopped_by_watchpoint
= 0;
2080 if (debug_linux_nat
)
2081 fprintf_unfiltered (gdb_stdlog
,
2082 "LLR: %s %s, %s (resume event thread)\n",
2083 step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2084 target_pid_to_str (ptid
),
2085 (signo
!= TARGET_SIGNAL_0
2086 ? strsignal (target_signal_to_host (signo
)) : "0"));
2088 restore_child_signals_mask (&prev_mask
);
2089 if (target_can_async_p ())
2090 target_async (inferior_event_handler
, 0);
2093 /* Send a signal to an LWP. */
2096 kill_lwp (int lwpid
, int signo
)
2098 /* Use tkill, if possible, in case we are using nptl threads. If tkill
2099 fails, then we are not using nptl threads and we should be using kill. */
2101 #ifdef HAVE_TKILL_SYSCALL
2103 static int tkill_failed
;
2110 ret
= syscall (__NR_tkill
, lwpid
, signo
);
2111 if (errno
!= ENOSYS
)
2118 return kill (lwpid
, signo
);
2121 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
2122 event, check if the core is interested in it: if not, ignore the
2123 event, and keep waiting; otherwise, we need to toggle the LWP's
2124 syscall entry/exit status, since the ptrace event itself doesn't
2125 indicate it, and report the trap to higher layers. */
2128 linux_handle_syscall_trap (struct lwp_info
*lp
, int stopping
)
2130 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
2131 struct gdbarch
*gdbarch
= target_thread_architecture (lp
->ptid
);
2132 int syscall_number
= (int) gdbarch_get_syscall_number (gdbarch
, lp
->ptid
);
2136 /* If we're stopping threads, there's a SIGSTOP pending, which
2137 makes it so that the LWP reports an immediate syscall return,
2138 followed by the SIGSTOP. Skip seeing that "return" using
2139 PTRACE_CONT directly, and let stop_wait_callback collect the
2140 SIGSTOP. Later when the thread is resumed, a new syscall
2141 entry event. If we didn't do this (and returned 0), we'd
2142 leave a syscall entry pending, and our caller, by using
2143 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
2144 itself. Later, when the user re-resumes this LWP, we'd see
2145 another syscall entry event and we'd mistake it for a return.
2147 If stop_wait_callback didn't force the SIGSTOP out of the LWP
2148 (leaving immediately with LWP->signalled set, without issuing
2149 a PTRACE_CONT), it would still be problematic to leave this
2150 syscall enter pending, as later when the thread is resumed,
2151 it would then see the same syscall exit mentioned above,
2152 followed by the delayed SIGSTOP, while the syscall didn't
2153 actually get to execute. It seems it would be even more
2154 confusing to the user. */
2156 if (debug_linux_nat
)
2157 fprintf_unfiltered (gdb_stdlog
,
2158 "LHST: ignoring syscall %d "
2159 "for LWP %ld (stopping threads), "
2160 "resuming with PTRACE_CONT for SIGSTOP\n",
2162 GET_LWP (lp
->ptid
));
2164 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2165 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2169 if (catch_syscall_enabled ())
2171 /* Always update the entry/return state, even if this particular
2172 syscall isn't interesting to the core now. In async mode,
2173 the user could install a new catchpoint for this syscall
2174 between syscall enter/return, and we'll need to know to
2175 report a syscall return if that happens. */
2176 lp
->syscall_state
= (lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
2177 ? TARGET_WAITKIND_SYSCALL_RETURN
2178 : TARGET_WAITKIND_SYSCALL_ENTRY
);
2180 if (catching_syscall_number (syscall_number
))
2182 /* Alright, an event to report. */
2183 ourstatus
->kind
= lp
->syscall_state
;
2184 ourstatus
->value
.syscall_number
= syscall_number
;
2186 if (debug_linux_nat
)
2187 fprintf_unfiltered (gdb_stdlog
,
2188 "LHST: stopping for %s of syscall %d"
2191 == TARGET_WAITKIND_SYSCALL_ENTRY
2192 ? "entry" : "return",
2194 GET_LWP (lp
->ptid
));
2198 if (debug_linux_nat
)
2199 fprintf_unfiltered (gdb_stdlog
,
2200 "LHST: ignoring %s of syscall %d "
2202 lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
2203 ? "entry" : "return",
2205 GET_LWP (lp
->ptid
));
2209 /* If we had been syscall tracing, and hence used PT_SYSCALL
2210 before on this LWP, it could happen that the user removes all
2211 syscall catchpoints before we get to process this event.
2212 There are two noteworthy issues here:
2214 - When stopped at a syscall entry event, resuming with
2215 PT_STEP still resumes executing the syscall and reports a
2218 - Only PT_SYSCALL catches syscall enters. If we last
2219 single-stepped this thread, then this event can't be a
2220 syscall enter. If we last single-stepped this thread, this
2221 has to be a syscall exit.
2223 The points above mean that the next resume, be it PT_STEP or
2224 PT_CONTINUE, can not trigger a syscall trace event. */
2225 if (debug_linux_nat
)
2226 fprintf_unfiltered (gdb_stdlog
,
2227 "LHST: caught syscall event "
2228 "with no syscall catchpoints."
2229 " %d for LWP %ld, ignoring\n",
2231 GET_LWP (lp
->ptid
));
2232 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2235 /* The core isn't interested in this event. For efficiency, avoid
2236 stopping all threads only to have the core resume them all again.
2237 Since we're not stopping threads, if we're still syscall tracing
2238 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
2239 subsequent syscall. Simply resume using the inf-ptrace layer,
2240 which knows when to use PT_SYSCALL or PT_CONTINUE. */
2242 /* Note that gdbarch_get_syscall_number may access registers, hence
2244 registers_changed ();
2245 if (linux_nat_prepare_to_resume
!= NULL
)
2246 linux_nat_prepare_to_resume (lp
);
2247 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
2248 lp
->step
, TARGET_SIGNAL_0
);
2252 /* Handle a GNU/Linux extended wait response. If we see a clone
2253 event, we need to add the new LWP to our list (and not report the
2254 trap to higher layers). This function returns non-zero if the
2255 event should be ignored and we should wait again. If STOPPING is
2256 true, the new LWP remains stopped, otherwise it is continued. */
2259 linux_handle_extended_wait (struct lwp_info
*lp
, int status
,
2262 int pid
= GET_LWP (lp
->ptid
);
2263 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
2264 int event
= status
>> 16;
2266 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
2267 || event
== PTRACE_EVENT_CLONE
)
2269 unsigned long new_pid
;
2272 ptrace (PTRACE_GETEVENTMSG
, pid
, 0, &new_pid
);
2274 /* If we haven't already seen the new PID stop, wait for it now. */
2275 if (! pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
2277 /* The new child has a pending SIGSTOP. We can't affect it until it
2278 hits the SIGSTOP, but we're already attached. */
2279 ret
= my_waitpid (new_pid
, &status
,
2280 (event
== PTRACE_EVENT_CLONE
) ? __WCLONE
: 0);
2282 perror_with_name (_("waiting for new child"));
2283 else if (ret
!= new_pid
)
2284 internal_error (__FILE__
, __LINE__
,
2285 _("wait returned unexpected PID %d"), ret
);
2286 else if (!WIFSTOPPED (status
))
2287 internal_error (__FILE__
, __LINE__
,
2288 _("wait returned unexpected status 0x%x"), status
);
2291 ourstatus
->value
.related_pid
= ptid_build (new_pid
, new_pid
, 0);
2293 if (event
== PTRACE_EVENT_FORK
2294 && linux_fork_checkpointing_p (GET_PID (lp
->ptid
)))
2296 /* Handle checkpointing by linux-fork.c here as a special
2297 case. We don't want the follow-fork-mode or 'catch fork'
2298 to interfere with this. */
2300 /* This won't actually modify the breakpoint list, but will
2301 physically remove the breakpoints from the child. */
2302 detach_breakpoints (new_pid
);
2304 /* Retain child fork in ptrace (stopped) state. */
2305 if (!find_fork_pid (new_pid
))
2308 /* Report as spurious, so that infrun doesn't want to follow
2309 this fork. We're actually doing an infcall in
2311 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
2312 linux_enable_event_reporting (pid_to_ptid (new_pid
));
2314 /* Report the stop to the core. */
2318 if (event
== PTRACE_EVENT_FORK
)
2319 ourstatus
->kind
= TARGET_WAITKIND_FORKED
;
2320 else if (event
== PTRACE_EVENT_VFORK
)
2321 ourstatus
->kind
= TARGET_WAITKIND_VFORKED
;
2324 struct lwp_info
*new_lp
;
2326 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2328 if (debug_linux_nat
)
2329 fprintf_unfiltered (gdb_stdlog
,
2330 "LHEW: Got clone event "
2331 "from LWP %d, new child is LWP %ld\n",
2334 new_lp
= add_lwp (BUILD_LWP (new_pid
, GET_PID (lp
->ptid
)));
2336 new_lp
->stopped
= 1;
2338 if (WSTOPSIG (status
) != SIGSTOP
)
2340 /* This can happen if someone starts sending signals to
2341 the new thread before it gets a chance to run, which
2342 have a lower number than SIGSTOP (e.g. SIGUSR1).
2343 This is an unlikely case, and harder to handle for
2344 fork / vfork than for clone, so we do not try - but
2345 we handle it for clone events here. We'll send
2346 the other signal on to the thread below. */
2348 new_lp
->signalled
= 1;
2352 struct thread_info
*tp
;
2354 /* When we stop for an event in some other thread, and
2355 pull the thread list just as this thread has cloned,
2356 we'll have seen the new thread in the thread_db list
2357 before handling the CLONE event (glibc's
2358 pthread_create adds the new thread to the thread list
2359 before clone'ing, and has the kernel fill in the
2360 thread's tid on the clone call with
2361 CLONE_PARENT_SETTID). If that happened, and the core
2362 had requested the new thread to stop, we'll have
2363 killed it with SIGSTOP. But since SIGSTOP is not an
2364 RT signal, it can only be queued once. We need to be
2365 careful to not resume the LWP if we wanted it to
2366 stop. In that case, we'll leave the SIGSTOP pending.
2367 It will later be reported as TARGET_SIGNAL_0. */
2368 tp
= find_thread_ptid (new_lp
->ptid
);
2369 if (tp
!= NULL
&& tp
->stop_requested
)
2370 new_lp
->last_resume_kind
= resume_stop
;
2377 /* Add the new thread to GDB's lists as soon as possible
2380 1) the frontend doesn't have to wait for a stop to
2383 2) we tag it with the correct running state. */
2385 /* If the thread_db layer is active, let it know about
2386 this new thread, and add it to GDB's list. */
2387 if (!thread_db_attach_lwp (new_lp
->ptid
))
2389 /* We're not using thread_db. Add it to GDB's
2391 target_post_attach (GET_LWP (new_lp
->ptid
));
2392 add_thread (new_lp
->ptid
);
2397 set_running (new_lp
->ptid
, 1);
2398 set_executing (new_lp
->ptid
, 1);
2399 /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced
2401 new_lp
->last_resume_kind
= resume_continue
;
2407 /* We created NEW_LP so it cannot yet contain STATUS. */
2408 gdb_assert (new_lp
->status
== 0);
2410 /* Save the wait status to report later. */
2411 if (debug_linux_nat
)
2412 fprintf_unfiltered (gdb_stdlog
,
2413 "LHEW: waitpid of new LWP %ld, "
2414 "saving status %s\n",
2415 (long) GET_LWP (new_lp
->ptid
),
2416 status_to_str (status
));
2417 new_lp
->status
= status
;
2420 /* Note the need to use the low target ops to resume, to
2421 handle resuming with PT_SYSCALL if we have syscall
2425 new_lp
->resumed
= 1;
2429 gdb_assert (new_lp
->last_resume_kind
== resume_continue
);
2430 if (debug_linux_nat
)
2431 fprintf_unfiltered (gdb_stdlog
,
2432 "LHEW: resuming new LWP %ld\n",
2433 GET_LWP (new_lp
->ptid
));
2434 if (linux_nat_prepare_to_resume
!= NULL
)
2435 linux_nat_prepare_to_resume (new_lp
);
2436 linux_ops
->to_resume (linux_ops
, pid_to_ptid (new_pid
),
2437 0, TARGET_SIGNAL_0
);
2438 new_lp
->stopped
= 0;
2442 if (debug_linux_nat
)
2443 fprintf_unfiltered (gdb_stdlog
,
2444 "LHEW: resuming parent LWP %d\n", pid
);
2445 if (linux_nat_prepare_to_resume
!= NULL
)
2446 linux_nat_prepare_to_resume (lp
);
2447 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
2448 0, TARGET_SIGNAL_0
);
2456 if (event
== PTRACE_EVENT_EXEC
)
2458 if (debug_linux_nat
)
2459 fprintf_unfiltered (gdb_stdlog
,
2460 "LHEW: Got exec event from LWP %ld\n",
2461 GET_LWP (lp
->ptid
));
2463 ourstatus
->kind
= TARGET_WAITKIND_EXECD
;
2464 ourstatus
->value
.execd_pathname
2465 = xstrdup (linux_child_pid_to_exec_file (pid
));
2470 if (event
== PTRACE_EVENT_VFORK_DONE
)
2472 if (current_inferior ()->waiting_for_vfork_done
)
2474 if (debug_linux_nat
)
2475 fprintf_unfiltered (gdb_stdlog
,
2476 "LHEW: Got expected PTRACE_EVENT_"
2477 "VFORK_DONE from LWP %ld: stopping\n",
2478 GET_LWP (lp
->ptid
));
2480 ourstatus
->kind
= TARGET_WAITKIND_VFORK_DONE
;
2484 if (debug_linux_nat
)
2485 fprintf_unfiltered (gdb_stdlog
,
2486 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2487 "from LWP %ld: resuming\n",
2488 GET_LWP (lp
->ptid
));
2489 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2493 internal_error (__FILE__
, __LINE__
,
2494 _("unknown ptrace event %d"), event
);
2497 /* Return non-zero if LWP is a zombie. */
2500 linux_lwp_is_zombie (long lwp
)
2502 char buffer
[MAXPATHLEN
];
2507 xsnprintf (buffer
, sizeof (buffer
), "/proc/%ld/status", lwp
);
2508 procfile
= fopen (buffer
, "r");
2509 if (procfile
== NULL
)
2511 warning (_("unable to open /proc file '%s'"), buffer
);
2516 while (fgets (buffer
, sizeof (buffer
), procfile
) != NULL
)
2517 if (strncmp (buffer
, "State:", 6) == 0)
2522 retval
= (have_state
2523 && strcmp (buffer
, "State:\tZ (zombie)\n") == 0);
2528 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2532 wait_lwp (struct lwp_info
*lp
)
2536 int thread_dead
= 0;
2539 gdb_assert (!lp
->stopped
);
2540 gdb_assert (lp
->status
== 0);
2542 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2543 block_child_signals (&prev_mask
);
2547 /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind
2548 was right and we should just call sigsuspend. */
2550 pid
= my_waitpid (GET_LWP (lp
->ptid
), &status
, WNOHANG
);
2551 if (pid
== -1 && errno
== ECHILD
)
2552 pid
= my_waitpid (GET_LWP (lp
->ptid
), &status
, __WCLONE
| WNOHANG
);
2553 if (pid
== -1 && errno
== ECHILD
)
2555 /* The thread has previously exited. We need to delete it
2556 now because, for some vendor 2.4 kernels with NPTL
2557 support backported, there won't be an exit event unless
2558 it is the main thread. 2.6 kernels will report an exit
2559 event for each thread that exits, as expected. */
2561 if (debug_linux_nat
)
2562 fprintf_unfiltered (gdb_stdlog
, "WL: %s vanished.\n",
2563 target_pid_to_str (lp
->ptid
));
2568 /* Bugs 10970, 12702.
2569 Thread group leader may have exited in which case we'll lock up in
2570 waitpid if there are other threads, even if they are all zombies too.
2571 Basically, we're not supposed to use waitpid this way.
2572 __WCLONE is not applicable for the leader so we can't use that.
2573 LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED
2574 process; it gets ESRCH both for the zombie and for running processes.
2576 As a workaround, check if we're waiting for the thread group leader and
2577 if it's a zombie, and avoid calling waitpid if it is.
2579 This is racy, what if the tgl becomes a zombie right after we check?
2580 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2581 waiting waitpid but the linux_lwp_is_zombie is safe this way. */
2583 if (GET_PID (lp
->ptid
) == GET_LWP (lp
->ptid
)
2584 && linux_lwp_is_zombie (GET_LWP (lp
->ptid
)))
2587 if (debug_linux_nat
)
2588 fprintf_unfiltered (gdb_stdlog
,
2589 "WL: Thread group leader %s vanished.\n",
2590 target_pid_to_str (lp
->ptid
));
2594 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2595 get invoked despite our caller had them intentionally blocked by
2596 block_child_signals. This is sensitive only to the loop of
2597 linux_nat_wait_1 and there if we get called my_waitpid gets called
2598 again before it gets to sigsuspend so we can safely let the handlers
2599 get executed here. */
2601 sigsuspend (&suspend_mask
);
2604 restore_child_signals_mask (&prev_mask
);
2608 gdb_assert (pid
== GET_LWP (lp
->ptid
));
2610 if (debug_linux_nat
)
2612 fprintf_unfiltered (gdb_stdlog
,
2613 "WL: waitpid %s received %s\n",
2614 target_pid_to_str (lp
->ptid
),
2615 status_to_str (status
));
2618 /* Check if the thread has exited. */
2619 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2622 if (debug_linux_nat
)
2623 fprintf_unfiltered (gdb_stdlog
, "WL: %s exited.\n",
2624 target_pid_to_str (lp
->ptid
));
2634 gdb_assert (WIFSTOPPED (status
));
2636 /* Handle GNU/Linux's syscall SIGTRAPs. */
2637 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2639 /* No longer need the sysgood bit. The ptrace event ends up
2640 recorded in lp->waitstatus if we care for it. We can carry
2641 on handling the event like a regular SIGTRAP from here
2643 status
= W_STOPCODE (SIGTRAP
);
2644 if (linux_handle_syscall_trap (lp
, 1))
2645 return wait_lwp (lp
);
2648 /* Handle GNU/Linux's extended waitstatus for trace events. */
2649 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 != 0)
2651 if (debug_linux_nat
)
2652 fprintf_unfiltered (gdb_stdlog
,
2653 "WL: Handling extended status 0x%06x\n",
2655 if (linux_handle_extended_wait (lp
, status
, 1))
2656 return wait_lwp (lp
);
2662 /* Save the most recent siginfo for LP. This is currently only called
2663 for SIGTRAP; some ports use the si_addr field for
2664 target_stopped_data_address. In the future, it may also be used to
2665 restore the siginfo of requeued signals. */
2668 save_siginfo (struct lwp_info
*lp
)
2671 ptrace (PTRACE_GETSIGINFO
, GET_LWP (lp
->ptid
),
2672 (PTRACE_TYPE_ARG3
) 0, &lp
->siginfo
);
2675 memset (&lp
->siginfo
, 0, sizeof (lp
->siginfo
));
2678 /* Send a SIGSTOP to LP. */
2681 stop_callback (struct lwp_info
*lp
, void *data
)
2683 if (!lp
->stopped
&& !lp
->signalled
)
2687 if (debug_linux_nat
)
2689 fprintf_unfiltered (gdb_stdlog
,
2690 "SC: kill %s **<SIGSTOP>**\n",
2691 target_pid_to_str (lp
->ptid
));
2694 ret
= kill_lwp (GET_LWP (lp
->ptid
), SIGSTOP
);
2695 if (debug_linux_nat
)
2697 fprintf_unfiltered (gdb_stdlog
,
2698 "SC: lwp kill %d %s\n",
2700 errno
? safe_strerror (errno
) : "ERRNO-OK");
2704 gdb_assert (lp
->status
== 0);
2710 /* Request a stop on LWP. */
2713 linux_stop_lwp (struct lwp_info
*lwp
)
2715 stop_callback (lwp
, NULL
);
2718 /* Return non-zero if LWP PID has a pending SIGINT. */
2721 linux_nat_has_pending_sigint (int pid
)
2723 sigset_t pending
, blocked
, ignored
;
2725 linux_proc_pending_signals (pid
, &pending
, &blocked
, &ignored
);
2727 if (sigismember (&pending
, SIGINT
)
2728 && !sigismember (&ignored
, SIGINT
))
2734 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2737 set_ignore_sigint (struct lwp_info
*lp
, void *data
)
2739 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2740 flag to consume the next one. */
2741 if (lp
->stopped
&& lp
->status
!= 0 && WIFSTOPPED (lp
->status
)
2742 && WSTOPSIG (lp
->status
) == SIGINT
)
2745 lp
->ignore_sigint
= 1;
2750 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2751 This function is called after we know the LWP has stopped; if the LWP
2752 stopped before the expected SIGINT was delivered, then it will never have
2753 arrived. Also, if the signal was delivered to a shared queue and consumed
2754 by a different thread, it will never be delivered to this LWP. */
2757 maybe_clear_ignore_sigint (struct lwp_info
*lp
)
2759 if (!lp
->ignore_sigint
)
2762 if (!linux_nat_has_pending_sigint (GET_LWP (lp
->ptid
)))
2764 if (debug_linux_nat
)
2765 fprintf_unfiltered (gdb_stdlog
,
2766 "MCIS: Clearing bogus flag for %s\n",
2767 target_pid_to_str (lp
->ptid
));
2768 lp
->ignore_sigint
= 0;
2772 /* Fetch the possible triggered data watchpoint info and store it in
2775 On some archs, like x86, that use debug registers to set
2776 watchpoints, it's possible that the way to know which watched
2777 address trapped, is to check the register that is used to select
2778 which address to watch. Problem is, between setting the watchpoint
2779 and reading back which data address trapped, the user may change
2780 the set of watchpoints, and, as a consequence, GDB changes the
2781 debug registers in the inferior. To avoid reading back a stale
2782 stopped-data-address when that happens, we cache in LP the fact
2783 that a watchpoint trapped, and the corresponding data address, as
2784 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2785 registers meanwhile, we have the cached data we can rely on. */
2788 save_sigtrap (struct lwp_info
*lp
)
2790 struct cleanup
*old_chain
;
2792 if (linux_ops
->to_stopped_by_watchpoint
== NULL
)
2794 lp
->stopped_by_watchpoint
= 0;
2798 old_chain
= save_inferior_ptid ();
2799 inferior_ptid
= lp
->ptid
;
2801 lp
->stopped_by_watchpoint
= linux_ops
->to_stopped_by_watchpoint ();
2803 if (lp
->stopped_by_watchpoint
)
2805 if (linux_ops
->to_stopped_data_address
!= NULL
)
2806 lp
->stopped_data_address_p
=
2807 linux_ops
->to_stopped_data_address (¤t_target
,
2808 &lp
->stopped_data_address
);
2810 lp
->stopped_data_address_p
= 0;
2813 do_cleanups (old_chain
);
2816 /* See save_sigtrap. */
2819 linux_nat_stopped_by_watchpoint (void)
2821 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2823 gdb_assert (lp
!= NULL
);
2825 return lp
->stopped_by_watchpoint
;
2829 linux_nat_stopped_data_address (struct target_ops
*ops
, CORE_ADDR
*addr_p
)
2831 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2833 gdb_assert (lp
!= NULL
);
2835 *addr_p
= lp
->stopped_data_address
;
2837 return lp
->stopped_data_address_p
;
2840 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2843 sigtrap_is_event (int status
)
2845 return WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
;
2848 /* SIGTRAP-like events recognizer. */
2850 static int (*linux_nat_status_is_event
) (int status
) = sigtrap_is_event
;
2852 /* Check for SIGTRAP-like events in LP. */
2855 linux_nat_lp_status_is_event (struct lwp_info
*lp
)
2857 /* We check for lp->waitstatus in addition to lp->status, because we can
2858 have pending process exits recorded in lp->status
2859 and W_EXITCODE(0,0) == 0. We should probably have an additional
2860 lp->status_p flag. */
2862 return (lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
2863 && linux_nat_status_is_event (lp
->status
));
2866 /* Set alternative SIGTRAP-like events recognizer. If
2867 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2871 linux_nat_set_status_is_event (struct target_ops
*t
,
2872 int (*status_is_event
) (int status
))
2874 linux_nat_status_is_event
= status_is_event
;
2877 /* Wait until LP is stopped. */
2880 stop_wait_callback (struct lwp_info
*lp
, void *data
)
2882 struct inferior
*inf
= find_inferior_pid (GET_PID (lp
->ptid
));
2884 /* If this is a vfork parent, bail out, it is not going to report
2885 any SIGSTOP until the vfork is done with. */
2886 if (inf
->vfork_child
!= NULL
)
2893 status
= wait_lwp (lp
);
2897 if (lp
->ignore_sigint
&& WIFSTOPPED (status
)
2898 && WSTOPSIG (status
) == SIGINT
)
2900 lp
->ignore_sigint
= 0;
2903 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2904 if (debug_linux_nat
)
2905 fprintf_unfiltered (gdb_stdlog
,
2906 "PTRACE_CONT %s, 0, 0 (%s) "
2907 "(discarding SIGINT)\n",
2908 target_pid_to_str (lp
->ptid
),
2909 errno
? safe_strerror (errno
) : "OK");
2911 return stop_wait_callback (lp
, NULL
);
2914 maybe_clear_ignore_sigint (lp
);
2916 if (WSTOPSIG (status
) != SIGSTOP
)
2918 if (linux_nat_status_is_event (status
))
2920 /* If a LWP other than the LWP that we're reporting an
2921 event for has hit a GDB breakpoint (as opposed to
2922 some random trap signal), then just arrange for it to
2923 hit it again later. We don't keep the SIGTRAP status
2924 and don't forward the SIGTRAP signal to the LWP. We
2925 will handle the current event, eventually we will
2926 resume all LWPs, and this one will get its breakpoint
2929 If we do not do this, then we run the risk that the
2930 user will delete or disable the breakpoint, but the
2931 thread will have already tripped on it. */
2933 /* Save the trap's siginfo in case we need it later. */
2938 /* Now resume this LWP and get the SIGSTOP event. */
2940 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2941 if (debug_linux_nat
)
2943 fprintf_unfiltered (gdb_stdlog
,
2944 "PTRACE_CONT %s, 0, 0 (%s)\n",
2945 target_pid_to_str (lp
->ptid
),
2946 errno
? safe_strerror (errno
) : "OK");
2948 fprintf_unfiltered (gdb_stdlog
,
2949 "SWC: Candidate SIGTRAP event in %s\n",
2950 target_pid_to_str (lp
->ptid
));
2952 /* Hold this event/waitstatus while we check to see if
2953 there are any more (we still want to get that SIGSTOP). */
2954 stop_wait_callback (lp
, NULL
);
2956 /* Hold the SIGTRAP for handling by linux_nat_wait. If
2957 there's another event, throw it back into the
2961 if (debug_linux_nat
)
2962 fprintf_unfiltered (gdb_stdlog
,
2963 "SWC: kill %s, %s\n",
2964 target_pid_to_str (lp
->ptid
),
2965 status_to_str ((int) status
));
2966 kill_lwp (GET_LWP (lp
->ptid
), WSTOPSIG (lp
->status
));
2969 /* Save the sigtrap event. */
2970 lp
->status
= status
;
2975 /* The thread was stopped with a signal other than
2976 SIGSTOP, and didn't accidentally trip a breakpoint. */
2978 if (debug_linux_nat
)
2980 fprintf_unfiltered (gdb_stdlog
,
2981 "SWC: Pending event %s in %s\n",
2982 status_to_str ((int) status
),
2983 target_pid_to_str (lp
->ptid
));
2985 /* Now resume this LWP and get the SIGSTOP event. */
2987 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2988 if (debug_linux_nat
)
2989 fprintf_unfiltered (gdb_stdlog
,
2990 "SWC: PTRACE_CONT %s, 0, 0 (%s)\n",
2991 target_pid_to_str (lp
->ptid
),
2992 errno
? safe_strerror (errno
) : "OK");
2994 /* Hold this event/waitstatus while we check to see if
2995 there are any more (we still want to get that SIGSTOP). */
2996 stop_wait_callback (lp
, NULL
);
2998 /* If the lp->status field is still empty, use it to
2999 hold this event. If not, then this event must be
3000 returned to the event queue of the LWP. */
3003 if (debug_linux_nat
)
3005 fprintf_unfiltered (gdb_stdlog
,
3006 "SWC: kill %s, %s\n",
3007 target_pid_to_str (lp
->ptid
),
3008 status_to_str ((int) status
));
3010 kill_lwp (GET_LWP (lp
->ptid
), WSTOPSIG (status
));
3013 lp
->status
= status
;
3019 /* We caught the SIGSTOP that we intended to catch, so
3020 there's no SIGSTOP pending. */
3029 /* Return non-zero if LP has a wait status pending. */
3032 status_callback (struct lwp_info
*lp
, void *data
)
3034 /* Only report a pending wait status if we pretend that this has
3035 indeed been resumed. */
3039 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3041 /* A ptrace event, like PTRACE_FORK|VFORK|EXEC, syscall event,
3042 or a pending process exit. Note that `W_EXITCODE(0,0) ==
3043 0', so a clean process exit can not be stored pending in
3044 lp->status, it is indistinguishable from
3045 no-pending-status. */
3049 if (lp
->status
!= 0)
3055 /* Return non-zero if LP isn't stopped. */
3058 running_callback (struct lwp_info
*lp
, void *data
)
3060 return (!lp
->stopped
3061 || ((lp
->status
!= 0
3062 || lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3066 /* Count the LWP's that have had events. */
3069 count_events_callback (struct lwp_info
*lp
, void *data
)
3073 gdb_assert (count
!= NULL
);
3075 /* Count only resumed LWPs that have a SIGTRAP event pending. */
3076 if (lp
->resumed
&& linux_nat_lp_status_is_event (lp
))
3082 /* Select the LWP (if any) that is currently being single-stepped. */
3085 select_singlestep_lwp_callback (struct lwp_info
*lp
, void *data
)
3087 if (lp
->last_resume_kind
== resume_step
3094 /* Select the Nth LWP that has had a SIGTRAP event. */
3097 select_event_lwp_callback (struct lwp_info
*lp
, void *data
)
3099 int *selector
= data
;
3101 gdb_assert (selector
!= NULL
);
3103 /* Select only resumed LWPs that have a SIGTRAP event pending. */
3104 if (lp
->resumed
&& linux_nat_lp_status_is_event (lp
))
3105 if ((*selector
)-- == 0)
3112 cancel_breakpoint (struct lwp_info
*lp
)
3114 /* Arrange for a breakpoint to be hit again later. We don't keep
3115 the SIGTRAP status and don't forward the SIGTRAP signal to the
3116 LWP. We will handle the current event, eventually we will resume
3117 this LWP, and this breakpoint will trap again.
3119 If we do not do this, then we run the risk that the user will
3120 delete or disable the breakpoint, but the LWP will have already
3123 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3124 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3127 pc
= regcache_read_pc (regcache
) - gdbarch_decr_pc_after_break (gdbarch
);
3128 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
3130 if (debug_linux_nat
)
3131 fprintf_unfiltered (gdb_stdlog
,
3132 "CB: Push back breakpoint for %s\n",
3133 target_pid_to_str (lp
->ptid
));
3135 /* Back up the PC if necessary. */
3136 if (gdbarch_decr_pc_after_break (gdbarch
))
3137 regcache_write_pc (regcache
, pc
);
3145 cancel_breakpoints_callback (struct lwp_info
*lp
, void *data
)
3147 struct lwp_info
*event_lp
= data
;
3149 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
3153 /* If a LWP other than the LWP that we're reporting an event for has
3154 hit a GDB breakpoint (as opposed to some random trap signal),
3155 then just arrange for it to hit it again later. We don't keep
3156 the SIGTRAP status and don't forward the SIGTRAP signal to the
3157 LWP. We will handle the current event, eventually we will resume
3158 all LWPs, and this one will get its breakpoint trap again.
3160 If we do not do this, then we run the risk that the user will
3161 delete or disable the breakpoint, but the LWP will have already
3164 if (linux_nat_lp_status_is_event (lp
)
3165 && cancel_breakpoint (lp
))
3166 /* Throw away the SIGTRAP. */
3172 /* Select one LWP out of those that have events pending. */
3175 select_event_lwp (ptid_t filter
, struct lwp_info
**orig_lp
, int *status
)
3178 int random_selector
;
3179 struct lwp_info
*event_lp
;
3181 /* Record the wait status for the original LWP. */
3182 (*orig_lp
)->status
= *status
;
3184 /* Give preference to any LWP that is being single-stepped. */
3185 event_lp
= iterate_over_lwps (filter
,
3186 select_singlestep_lwp_callback
, NULL
);
3187 if (event_lp
!= NULL
)
3189 if (debug_linux_nat
)
3190 fprintf_unfiltered (gdb_stdlog
,
3191 "SEL: Select single-step %s\n",
3192 target_pid_to_str (event_lp
->ptid
));
3196 /* No single-stepping LWP. Select one at random, out of those
3197 which have had SIGTRAP events. */
3199 /* First see how many SIGTRAP events we have. */
3200 iterate_over_lwps (filter
, count_events_callback
, &num_events
);
3202 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
3203 random_selector
= (int)
3204 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
3206 if (debug_linux_nat
&& num_events
> 1)
3207 fprintf_unfiltered (gdb_stdlog
,
3208 "SEL: Found %d SIGTRAP events, selecting #%d\n",
3209 num_events
, random_selector
);
3211 event_lp
= iterate_over_lwps (filter
,
3212 select_event_lwp_callback
,
3216 if (event_lp
!= NULL
)
3218 /* Switch the event LWP. */
3219 *orig_lp
= event_lp
;
3220 *status
= event_lp
->status
;
3223 /* Flush the wait status for the event LWP. */
3224 (*orig_lp
)->status
= 0;
3227 /* Return non-zero if LP has been resumed. */
3230 resumed_callback (struct lwp_info
*lp
, void *data
)
3235 /* Stop an active thread, verify it still exists, then resume it. If
3236 the thread ends up with a pending status, then it is not resumed,
3237 and *DATA (really a pointer to int), is set. */
3240 stop_and_resume_callback (struct lwp_info
*lp
, void *data
)
3242 int *new_pending_p
= data
;
3246 ptid_t ptid
= lp
->ptid
;
3248 stop_callback (lp
, NULL
);
3249 stop_wait_callback (lp
, NULL
);
3251 /* Resume if the lwp still exists, and the core wanted it
3253 lp
= find_lwp_pid (ptid
);
3256 if (lp
->last_resume_kind
== resume_stop
3259 /* The core wanted the LWP to stop. Even if it stopped
3260 cleanly (with SIGSTOP), leave the event pending. */
3261 if (debug_linux_nat
)
3262 fprintf_unfiltered (gdb_stdlog
,
3263 "SARC: core wanted LWP %ld stopped "
3264 "(leaving SIGSTOP pending)\n",
3265 GET_LWP (lp
->ptid
));
3266 lp
->status
= W_STOPCODE (SIGSTOP
);
3269 if (lp
->status
== 0)
3271 if (debug_linux_nat
)
3272 fprintf_unfiltered (gdb_stdlog
,
3273 "SARC: re-resuming LWP %ld\n",
3274 GET_LWP (lp
->ptid
));
3275 resume_lwp (lp
, lp
->step
);
3279 if (debug_linux_nat
)
3280 fprintf_unfiltered (gdb_stdlog
,
3281 "SARC: not re-resuming LWP %ld "
3283 GET_LWP (lp
->ptid
));
3292 /* Check if we should go on and pass this event to common code.
3293 Return the affected lwp if we are, or NULL otherwise. If we stop
3294 all lwps temporarily, we may end up with new pending events in some
3295 other lwp. In that case set *NEW_PENDING_P to true. */
3297 static struct lwp_info
*
3298 linux_nat_filter_event (int lwpid
, int status
, int *new_pending_p
)
3300 struct lwp_info
*lp
;
3304 lp
= find_lwp_pid (pid_to_ptid (lwpid
));
3306 /* Check for stop events reported by a process we didn't already
3307 know about - anything not already in our LWP list.
3309 If we're expecting to receive stopped processes after
3310 fork, vfork, and clone events, then we'll just add the
3311 new one to our list and go back to waiting for the event
3312 to be reported - the stopped process might be returned
3313 from waitpid before or after the event is.
3315 But note the case of a non-leader thread exec'ing after the
3316 leader having exited, and gone from our lists. The non-leader
3317 thread changes its tid to the tgid. */
3319 if (WIFSTOPPED (status
) && lp
== NULL
3320 && (WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 == PTRACE_EVENT_EXEC
))
3322 /* A multi-thread exec after we had seen the leader exiting. */
3323 if (debug_linux_nat
)
3324 fprintf_unfiltered (gdb_stdlog
,
3325 "LLW: Re-adding thread group leader LWP %d.\n",
3328 lp
= add_lwp (BUILD_LWP (lwpid
, lwpid
));
3331 add_thread (lp
->ptid
);
3334 if (WIFSTOPPED (status
) && !lp
)
3336 add_to_pid_list (&stopped_pids
, lwpid
, status
);
3340 /* Make sure we don't report an event for the exit of an LWP not in
3341 our list, i.e. not part of the current process. This can happen
3342 if we detach from a program we originally forked and then it
3344 if (!WIFSTOPPED (status
) && !lp
)
3347 /* Handle GNU/Linux's syscall SIGTRAPs. */
3348 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
3350 /* No longer need the sysgood bit. The ptrace event ends up
3351 recorded in lp->waitstatus if we care for it. We can carry
3352 on handling the event like a regular SIGTRAP from here
3354 status
= W_STOPCODE (SIGTRAP
);
3355 if (linux_handle_syscall_trap (lp
, 0))
3359 /* Handle GNU/Linux's extended waitstatus for trace events. */
3360 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 != 0)
3362 if (debug_linux_nat
)
3363 fprintf_unfiltered (gdb_stdlog
,
3364 "LLW: Handling extended status 0x%06x\n",
3366 if (linux_handle_extended_wait (lp
, status
, 0))
3370 if (linux_nat_status_is_event (status
))
3372 /* Save the trap's siginfo in case we need it later. */
3378 /* Check if the thread has exited. */
3379 if ((WIFEXITED (status
) || WIFSIGNALED (status
))
3380 && num_lwps (GET_PID (lp
->ptid
)) > 1)
3382 /* If this is the main thread, we must stop all threads and verify
3383 if they are still alive. This is because in the nptl thread model
3384 on Linux 2.4, there is no signal issued for exiting LWPs
3385 other than the main thread. We only get the main thread exit
3386 signal once all child threads have already exited. If we
3387 stop all the threads and use the stop_wait_callback to check
3388 if they have exited we can determine whether this signal
3389 should be ignored or whether it means the end of the debugged
3390 application, regardless of which threading model is being
3392 if (GET_PID (lp
->ptid
) == GET_LWP (lp
->ptid
))
3395 iterate_over_lwps (pid_to_ptid (GET_PID (lp
->ptid
)),
3396 stop_and_resume_callback
, new_pending_p
);
3399 if (debug_linux_nat
)
3400 fprintf_unfiltered (gdb_stdlog
,
3401 "LLW: %s exited.\n",
3402 target_pid_to_str (lp
->ptid
));
3404 if (num_lwps (GET_PID (lp
->ptid
)) > 1)
3406 /* If there is at least one more LWP, then the exit signal
3407 was not the end of the debugged application and should be
3414 /* Check if the current LWP has previously exited. In the nptl
3415 thread model, LWPs other than the main thread do not issue
3416 signals when they exit so we must check whenever the thread has
3417 stopped. A similar check is made in stop_wait_callback(). */
3418 if (num_lwps (GET_PID (lp
->ptid
)) > 1 && !linux_thread_alive (lp
->ptid
))
3420 ptid_t ptid
= pid_to_ptid (GET_PID (lp
->ptid
));
3422 if (debug_linux_nat
)
3423 fprintf_unfiltered (gdb_stdlog
,
3424 "LLW: %s exited.\n",
3425 target_pid_to_str (lp
->ptid
));
3429 /* Make sure there is at least one thread running. */
3430 gdb_assert (iterate_over_lwps (ptid
, running_callback
, NULL
));
3432 /* Discard the event. */
3436 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3437 an attempt to stop an LWP. */
3439 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGSTOP
)
3441 if (debug_linux_nat
)
3442 fprintf_unfiltered (gdb_stdlog
,
3443 "LLW: Delayed SIGSTOP caught for %s.\n",
3444 target_pid_to_str (lp
->ptid
));
3448 if (lp
->last_resume_kind
!= resume_stop
)
3450 /* This is a delayed SIGSTOP. */
3452 registers_changed ();
3454 if (linux_nat_prepare_to_resume
!= NULL
)
3455 linux_nat_prepare_to_resume (lp
);
3456 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
3457 lp
->step
, TARGET_SIGNAL_0
);
3458 if (debug_linux_nat
)
3459 fprintf_unfiltered (gdb_stdlog
,
3460 "LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
3462 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3463 target_pid_to_str (lp
->ptid
));
3466 gdb_assert (lp
->resumed
);
3468 /* Discard the event. */
3473 /* Make sure we don't report a SIGINT that we have already displayed
3474 for another thread. */
3475 if (lp
->ignore_sigint
3476 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGINT
)
3478 if (debug_linux_nat
)
3479 fprintf_unfiltered (gdb_stdlog
,
3480 "LLW: Delayed SIGINT caught for %s.\n",
3481 target_pid_to_str (lp
->ptid
));
3483 /* This is a delayed SIGINT. */
3484 lp
->ignore_sigint
= 0;
3486 registers_changed ();
3487 if (linux_nat_prepare_to_resume
!= NULL
)
3488 linux_nat_prepare_to_resume (lp
);
3489 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
3490 lp
->step
, TARGET_SIGNAL_0
);
3491 if (debug_linux_nat
)
3492 fprintf_unfiltered (gdb_stdlog
,
3493 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3495 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3496 target_pid_to_str (lp
->ptid
));
3499 gdb_assert (lp
->resumed
);
3501 /* Discard the event. */
3505 /* An interesting event. */
3507 lp
->status
= status
;
3511 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3512 their exits until all other threads in the group have exited. */
3515 check_zombie_leaders (void)
3517 struct inferior
*inf
;
3521 struct lwp_info
*leader_lp
;
3526 leader_lp
= find_lwp_pid (pid_to_ptid (inf
->pid
));
3527 if (leader_lp
!= NULL
3528 /* Check if there are other threads in the group, as we may
3529 have raced with the inferior simply exiting. */
3530 && num_lwps (inf
->pid
) > 1
3531 && linux_lwp_is_zombie (inf
->pid
))
3533 if (debug_linux_nat
)
3534 fprintf_unfiltered (gdb_stdlog
,
3535 "CZL: Thread group leader %d zombie "
3536 "(it exited, or another thread execd).\n",
3539 /* A leader zombie can mean one of two things:
3541 - It exited, and there's an exit status pending
3542 available, or only the leader exited (not the whole
3543 program). In the latter case, we can't waitpid the
3544 leader's exit status until all other threads are gone.
3546 - There are 3 or more threads in the group, and a thread
3547 other than the leader exec'd. On an exec, the Linux
3548 kernel destroys all other threads (except the execing
3549 one) in the thread group, and resets the execing thread's
3550 tid to the tgid. No exit notification is sent for the
3551 execing thread -- from the ptracer's perspective, it
3552 appears as though the execing thread just vanishes.
3553 Until we reap all other threads except the leader and the
3554 execing thread, the leader will be zombie, and the
3555 execing thread will be in `D (disc sleep)'. As soon as
3556 all other threads are reaped, the execing thread changes
3557 it's tid to the tgid, and the previous (zombie) leader
3558 vanishes, giving place to the "new" leader. We could try
3559 distinguishing the exit and exec cases, by waiting once
3560 more, and seeing if something comes out, but it doesn't
3561 sound useful. The previous leader _does_ go away, and
3562 we'll re-add the new one once we see the exec event
3563 (which is just the same as what would happen if the
3564 previous leader did exit voluntarily before some other
3567 if (debug_linux_nat
)
3568 fprintf_unfiltered (gdb_stdlog
,
3569 "CZL: Thread group leader %d vanished.\n",
3571 exit_lwp (leader_lp
);
3577 linux_nat_wait_1 (struct target_ops
*ops
,
3578 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3581 static sigset_t prev_mask
;
3582 enum resume_kind last_resume_kind
;
3583 struct lwp_info
*lp
;
3586 if (debug_linux_nat
)
3587 fprintf_unfiltered (gdb_stdlog
, "LLW: enter\n");
3589 /* The first time we get here after starting a new inferior, we may
3590 not have added it to the LWP list yet - this is the earliest
3591 moment at which we know its PID. */
3592 if (ptid_is_pid (inferior_ptid
))
3594 /* Upgrade the main thread's ptid. */
3595 thread_change_ptid (inferior_ptid
,
3596 BUILD_LWP (GET_PID (inferior_ptid
),
3597 GET_PID (inferior_ptid
)));
3599 lp
= add_lwp (inferior_ptid
);
3603 /* Make sure SIGCHLD is blocked. */
3604 block_child_signals (&prev_mask
);
3610 /* First check if there is a LWP with a wait status pending. */
3611 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3613 /* Any LWP in the PTID group that's been resumed will do. */
3614 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3617 if (debug_linux_nat
&& lp
->status
)
3618 fprintf_unfiltered (gdb_stdlog
,
3619 "LLW: Using pending wait status %s for %s.\n",
3620 status_to_str (lp
->status
),
3621 target_pid_to_str (lp
->ptid
));
3624 else if (is_lwp (ptid
))
3626 if (debug_linux_nat
)
3627 fprintf_unfiltered (gdb_stdlog
,
3628 "LLW: Waiting for specific LWP %s.\n",
3629 target_pid_to_str (ptid
));
3631 /* We have a specific LWP to check. */
3632 lp
= find_lwp_pid (ptid
);
3635 if (debug_linux_nat
&& lp
->status
)
3636 fprintf_unfiltered (gdb_stdlog
,
3637 "LLW: Using pending wait status %s for %s.\n",
3638 status_to_str (lp
->status
),
3639 target_pid_to_str (lp
->ptid
));
3641 /* We check for lp->waitstatus in addition to lp->status,
3642 because we can have pending process exits recorded in
3643 lp->status and W_EXITCODE(0,0) == 0. We should probably have
3644 an additional lp->status_p flag. */
3645 if (lp
->status
== 0 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
3649 if (lp
&& lp
->signalled
&& lp
->last_resume_kind
!= resume_stop
)
3651 /* A pending SIGSTOP may interfere with the normal stream of
3652 events. In a typical case where interference is a problem,
3653 we have a SIGSTOP signal pending for LWP A while
3654 single-stepping it, encounter an event in LWP B, and take the
3655 pending SIGSTOP while trying to stop LWP A. After processing
3656 the event in LWP B, LWP A is continued, and we'll never see
3657 the SIGTRAP associated with the last time we were
3658 single-stepping LWP A. */
3660 /* Resume the thread. It should halt immediately returning the
3662 registers_changed ();
3663 if (linux_nat_prepare_to_resume
!= NULL
)
3664 linux_nat_prepare_to_resume (lp
);
3665 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
3666 lp
->step
, TARGET_SIGNAL_0
);
3667 if (debug_linux_nat
)
3668 fprintf_unfiltered (gdb_stdlog
,
3669 "LLW: %s %s, 0, 0 (expect SIGSTOP)\n",
3670 lp
->step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3671 target_pid_to_str (lp
->ptid
));
3673 gdb_assert (lp
->resumed
);
3675 /* Catch the pending SIGSTOP. */
3676 status
= lp
->status
;
3679 stop_wait_callback (lp
, NULL
);
3681 /* If the lp->status field isn't empty, we caught another signal
3682 while flushing the SIGSTOP. Return it back to the event
3683 queue of the LWP, as we already have an event to handle. */
3686 if (debug_linux_nat
)
3687 fprintf_unfiltered (gdb_stdlog
,
3688 "LLW: kill %s, %s\n",
3689 target_pid_to_str (lp
->ptid
),
3690 status_to_str (lp
->status
));
3691 kill_lwp (GET_LWP (lp
->ptid
), WSTOPSIG (lp
->status
));
3694 lp
->status
= status
;
3697 if (!target_can_async_p ())
3699 /* Causes SIGINT to be passed on to the attached process. */
3703 /* But if we don't find a pending event, we'll have to wait. */
3709 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3712 - If the thread group leader exits while other threads in the
3713 thread group still exist, waitpid(TGID, ...) hangs. That
3714 waitpid won't return an exit status until the other threads
3715 in the group are reapped.
3717 - When a non-leader thread execs, that thread just vanishes
3718 without reporting an exit (so we'd hang if we waited for it
3719 explicitly in that case). The exec event is reported to
3723 lwpid
= my_waitpid (-1, &status
, __WCLONE
| WNOHANG
);
3724 if (lwpid
== 0 || (lwpid
== -1 && errno
== ECHILD
))
3725 lwpid
= my_waitpid (-1, &status
, WNOHANG
);
3727 if (debug_linux_nat
)
3728 fprintf_unfiltered (gdb_stdlog
,
3729 "LNW: waitpid(-1, ...) returned %d, %s\n",
3730 lwpid
, errno
? safe_strerror (errno
) : "ERRNO-OK");
3734 /* If this is true, then we paused LWPs momentarily, and may
3735 now have pending events to handle. */
3738 if (debug_linux_nat
)
3740 fprintf_unfiltered (gdb_stdlog
,
3741 "LLW: waitpid %ld received %s\n",
3742 (long) lwpid
, status_to_str (status
));
3745 lp
= linux_nat_filter_event (lwpid
, status
, &new_pending
);
3747 /* STATUS is now no longer valid, use LP->STATUS instead. */
3750 if (lp
&& !ptid_match (lp
->ptid
, ptid
))
3752 gdb_assert (lp
->resumed
);
3754 if (debug_linux_nat
)
3756 "LWP %ld got an event %06x, leaving pending.\n",
3757 ptid_get_lwp (lp
->ptid
), lp
->status
);
3759 if (WIFSTOPPED (lp
->status
))
3761 if (WSTOPSIG (lp
->status
) != SIGSTOP
)
3763 /* Cancel breakpoint hits. The breakpoint may
3764 be removed before we fetch events from this
3765 process to report to the core. It is best
3766 not to assume the moribund breakpoints
3767 heuristic always handles these cases --- it
3768 could be too many events go through to the
3769 core before this one is handled. All-stop
3770 always cancels breakpoint hits in all
3773 && linux_nat_lp_status_is_event (lp
)
3774 && cancel_breakpoint (lp
))
3776 /* Throw away the SIGTRAP. */
3779 if (debug_linux_nat
)
3781 "LLW: LWP %ld hit a breakpoint while"
3782 " waiting for another process;"
3784 ptid_get_lwp (lp
->ptid
));
3794 else if (WIFEXITED (lp
->status
) || WIFSIGNALED (lp
->status
))
3796 if (debug_linux_nat
)
3798 "Process %ld exited while stopping LWPs\n",
3799 ptid_get_lwp (lp
->ptid
));
3801 /* This was the last lwp in the process. Since
3802 events are serialized to GDB core, and we can't
3803 report this one right now, but GDB core and the
3804 other target layers will want to be notified
3805 about the exit code/signal, leave the status
3806 pending for the next time we're able to report
3809 /* Prevent trying to stop this thread again. We'll
3810 never try to resume it because it has a pending
3814 /* Dead LWP's aren't expected to reported a pending
3818 /* Store the pending event in the waitstatus as
3819 well, because W_EXITCODE(0,0) == 0. */
3820 store_waitstatus (&lp
->waitstatus
, lp
->status
);
3829 /* Some LWP now has a pending event. Go all the way
3830 back to check it. */
3836 /* We got an event to report to the core. */
3840 /* Retry until nothing comes out of waitpid. A single
3841 SIGCHLD can indicate more than one child stopped. */
3845 /* Check for zombie thread group leaders. Those can't be reaped
3846 until all other threads in the thread group are. */
3847 check_zombie_leaders ();
3849 /* If there are no resumed children left, bail. We'd be stuck
3850 forever in the sigsuspend call below otherwise. */
3851 if (iterate_over_lwps (ptid
, resumed_callback
, NULL
) == NULL
)
3853 if (debug_linux_nat
)
3854 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (no resumed LWP)\n");
3856 ourstatus
->kind
= TARGET_WAITKIND_NO_RESUMED
;
3858 if (!target_can_async_p ())
3859 clear_sigint_trap ();
3861 restore_child_signals_mask (&prev_mask
);
3862 return minus_one_ptid
;
3865 /* No interesting event to report to the core. */
3867 if (target_options
& TARGET_WNOHANG
)
3869 if (debug_linux_nat
)
3870 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (ignore)\n");
3872 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3873 restore_child_signals_mask (&prev_mask
);
3874 return minus_one_ptid
;
3877 /* We shouldn't end up here unless we want to try again. */
3878 gdb_assert (lp
== NULL
);
3880 /* Block until we get an event reported with SIGCHLD. */
3881 sigsuspend (&suspend_mask
);
3884 if (!target_can_async_p ())
3885 clear_sigint_trap ();
3889 status
= lp
->status
;
3892 /* Don't report signals that GDB isn't interested in, such as
3893 signals that are neither printed nor stopped upon. Stopping all
3894 threads can be a bit time-consuming so if we want decent
3895 performance with heavily multi-threaded programs, especially when
3896 they're using a high frequency timer, we'd better avoid it if we
3899 if (WIFSTOPPED (status
))
3901 enum target_signal signo
= target_signal_from_host (WSTOPSIG (status
));
3903 /* When using hardware single-step, we need to report every signal.
3904 Otherwise, signals in pass_mask may be short-circuited. */
3906 && WSTOPSIG (status
) && sigismember (&pass_mask
, WSTOPSIG (status
)))
3908 /* FIMXE: kettenis/2001-06-06: Should we resume all threads
3909 here? It is not clear we should. GDB may not expect
3910 other threads to run. On the other hand, not resuming
3911 newly attached threads may cause an unwanted delay in
3912 getting them running. */
3913 registers_changed ();
3914 if (linux_nat_prepare_to_resume
!= NULL
)
3915 linux_nat_prepare_to_resume (lp
);
3916 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
3918 if (debug_linux_nat
)
3919 fprintf_unfiltered (gdb_stdlog
,
3920 "LLW: %s %s, %s (preempt 'handle')\n",
3922 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3923 target_pid_to_str (lp
->ptid
),
3924 (signo
!= TARGET_SIGNAL_0
3925 ? strsignal (target_signal_to_host (signo
))
3933 /* Only do the below in all-stop, as we currently use SIGINT
3934 to implement target_stop (see linux_nat_stop) in
3936 if (signo
== TARGET_SIGNAL_INT
&& signal_pass_state (signo
) == 0)
3938 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3939 forwarded to the entire process group, that is, all LWPs
3940 will receive it - unless they're using CLONE_THREAD to
3941 share signals. Since we only want to report it once, we
3942 mark it as ignored for all LWPs except this one. */
3943 iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid
)),
3944 set_ignore_sigint
, NULL
);
3945 lp
->ignore_sigint
= 0;
3948 maybe_clear_ignore_sigint (lp
);
3952 /* This LWP is stopped now. */
3955 if (debug_linux_nat
)
3956 fprintf_unfiltered (gdb_stdlog
, "LLW: Candidate event %s in %s.\n",
3957 status_to_str (status
), target_pid_to_str (lp
->ptid
));
3961 /* Now stop all other LWP's ... */
3962 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
3964 /* ... and wait until all of them have reported back that
3965 they're no longer running. */
3966 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
3968 /* If we're not waiting for a specific LWP, choose an event LWP
3969 from among those that have had events. Giving equal priority
3970 to all LWPs that have had events helps prevent
3972 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3973 select_event_lwp (ptid
, &lp
, &status
);
3975 /* Now that we've selected our final event LWP, cancel any
3976 breakpoints in other LWPs that have hit a GDB breakpoint.
3977 See the comment in cancel_breakpoints_callback to find out
3979 iterate_over_lwps (minus_one_ptid
, cancel_breakpoints_callback
, lp
);
3981 /* We'll need this to determine whether to report a SIGSTOP as
3982 TARGET_WAITKIND_0. Need to take a copy because
3983 resume_clear_callback clears it. */
3984 last_resume_kind
= lp
->last_resume_kind
;
3986 /* In all-stop, from the core's perspective, all LWPs are now
3987 stopped until a new resume action is sent over. */
3988 iterate_over_lwps (minus_one_ptid
, resume_clear_callback
, NULL
);
3993 last_resume_kind
= lp
->last_resume_kind
;
3994 resume_clear_callback (lp
, NULL
);
3997 if (linux_nat_status_is_event (status
))
3999 if (debug_linux_nat
)
4000 fprintf_unfiltered (gdb_stdlog
,
4001 "LLW: trap ptid is %s.\n",
4002 target_pid_to_str (lp
->ptid
));
4005 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
4007 *ourstatus
= lp
->waitstatus
;
4008 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4011 store_waitstatus (ourstatus
, status
);
4013 if (debug_linux_nat
)
4014 fprintf_unfiltered (gdb_stdlog
, "LLW: exit\n");
4016 restore_child_signals_mask (&prev_mask
);
4018 if (last_resume_kind
== resume_stop
4019 && ourstatus
->kind
== TARGET_WAITKIND_STOPPED
4020 && WSTOPSIG (status
) == SIGSTOP
)
4022 /* A thread that has been requested to stop by GDB with
4023 target_stop, and it stopped cleanly, so report as SIG0. The
4024 use of SIGSTOP is an implementation detail. */
4025 ourstatus
->value
.sig
= TARGET_SIGNAL_0
;
4028 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
4029 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
4032 lp
->core
= linux_nat_core_of_thread_1 (lp
->ptid
);
4037 /* Resume LWPs that are currently stopped without any pending status
4038 to report, but are resumed from the core's perspective. */
4041 resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
)
4043 ptid_t
*wait_ptid_p
= data
;
4048 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
4050 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
4051 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
4052 CORE_ADDR pc
= regcache_read_pc (regcache
);
4054 gdb_assert (is_executing (lp
->ptid
));
4056 /* Don't bother if there's a breakpoint at PC that we'd hit
4057 immediately, and we're not waiting for this LWP. */
4058 if (!ptid_match (lp
->ptid
, *wait_ptid_p
))
4060 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
4064 if (debug_linux_nat
)
4065 fprintf_unfiltered (gdb_stdlog
,
4066 "RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n",
4067 target_pid_to_str (lp
->ptid
),
4068 paddress (gdbarch
, pc
),
4071 registers_changed ();
4072 if (linux_nat_prepare_to_resume
!= NULL
)
4073 linux_nat_prepare_to_resume (lp
);
4074 linux_ops
->to_resume (linux_ops
, pid_to_ptid (GET_LWP (lp
->ptid
)),
4075 lp
->step
, TARGET_SIGNAL_0
);
4077 memset (&lp
->siginfo
, 0, sizeof (lp
->siginfo
));
4078 lp
->stopped_by_watchpoint
= 0;
4085 linux_nat_wait (struct target_ops
*ops
,
4086 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
4091 if (debug_linux_nat
)
4092 fprintf_unfiltered (gdb_stdlog
,
4093 "linux_nat_wait: [%s]\n", target_pid_to_str (ptid
));
4095 /* Flush the async file first. */
4096 if (target_can_async_p ())
4097 async_file_flush ();
4099 /* Resume LWPs that are currently stopped without any pending status
4100 to report, but are resumed from the core's perspective. LWPs get
4101 in this state if we find them stopping at a time we're not
4102 interested in reporting the event (target_wait on a
4103 specific_process, for example, see linux_nat_wait_1), and
4104 meanwhile the event became uninteresting. Don't bother resuming
4105 LWPs we're not going to wait for if they'd stop immediately. */
4107 iterate_over_lwps (minus_one_ptid
, resume_stopped_resumed_lwps
, &ptid
);
4109 event_ptid
= linux_nat_wait_1 (ops
, ptid
, ourstatus
, target_options
);
4111 /* If we requested any event, and something came out, assume there
4112 may be more. If we requested a specific lwp or process, also
4113 assume there may be more. */
4114 if (target_can_async_p ()
4115 && ((ourstatus
->kind
!= TARGET_WAITKIND_IGNORE
4116 && ourstatus
->kind
!= TARGET_WAITKIND_NO_RESUMED
)
4117 || !ptid_equal (ptid
, minus_one_ptid
)))
4120 /* Get ready for the next event. */
4121 if (target_can_async_p ())
4122 target_async (inferior_event_handler
, 0);
4128 kill_callback (struct lwp_info
*lp
, void *data
)
4130 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
4133 kill (GET_LWP (lp
->ptid
), SIGKILL
);
4134 if (debug_linux_nat
)
4135 fprintf_unfiltered (gdb_stdlog
,
4136 "KC: kill (SIGKILL) %s, 0, 0 (%s)\n",
4137 target_pid_to_str (lp
->ptid
),
4138 errno
? safe_strerror (errno
) : "OK");
4140 /* Some kernels ignore even SIGKILL for processes under ptrace. */
4143 ptrace (PTRACE_KILL
, GET_LWP (lp
->ptid
), 0, 0);
4144 if (debug_linux_nat
)
4145 fprintf_unfiltered (gdb_stdlog
,
4146 "KC: PTRACE_KILL %s, 0, 0 (%s)\n",
4147 target_pid_to_str (lp
->ptid
),
4148 errno
? safe_strerror (errno
) : "OK");
4154 kill_wait_callback (struct lwp_info
*lp
, void *data
)
4158 /* We must make sure that there are no pending events (delayed
4159 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
4160 program doesn't interfere with any following debugging session. */
4162 /* For cloned processes we must check both with __WCLONE and
4163 without, since the exit status of a cloned process isn't reported
4169 pid
= my_waitpid (GET_LWP (lp
->ptid
), NULL
, __WCLONE
);
4170 if (pid
!= (pid_t
) -1)
4172 if (debug_linux_nat
)
4173 fprintf_unfiltered (gdb_stdlog
,
4174 "KWC: wait %s received unknown.\n",
4175 target_pid_to_str (lp
->ptid
));
4176 /* The Linux kernel sometimes fails to kill a thread
4177 completely after PTRACE_KILL; that goes from the stop
4178 point in do_fork out to the one in
4179 get_signal_to_deliever and waits again. So kill it
4181 kill_callback (lp
, NULL
);
4184 while (pid
== GET_LWP (lp
->ptid
));
4186 gdb_assert (pid
== -1 && errno
== ECHILD
);
4191 pid
= my_waitpid (GET_LWP (lp
->ptid
), NULL
, 0);
4192 if (pid
!= (pid_t
) -1)
4194 if (debug_linux_nat
)
4195 fprintf_unfiltered (gdb_stdlog
,
4196 "KWC: wait %s received unk.\n",
4197 target_pid_to_str (lp
->ptid
));
4198 /* See the call to kill_callback above. */
4199 kill_callback (lp
, NULL
);
4202 while (pid
== GET_LWP (lp
->ptid
));
4204 gdb_assert (pid
== -1 && errno
== ECHILD
);
4209 linux_nat_kill (struct target_ops
*ops
)
4211 struct target_waitstatus last
;
4215 /* If we're stopped while forking and we haven't followed yet,
4216 kill the other task. We need to do this first because the
4217 parent will be sleeping if this is a vfork. */
4219 get_last_target_status (&last_ptid
, &last
);
4221 if (last
.kind
== TARGET_WAITKIND_FORKED
4222 || last
.kind
== TARGET_WAITKIND_VFORKED
)
4224 ptrace (PT_KILL
, PIDGET (last
.value
.related_pid
), 0, 0);
4228 if (forks_exist_p ())
4229 linux_fork_killall ();
4232 ptid_t ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
4234 /* Stop all threads before killing them, since ptrace requires
4235 that the thread is stopped to sucessfully PTRACE_KILL. */
4236 iterate_over_lwps (ptid
, stop_callback
, NULL
);
4237 /* ... and wait until all of them have reported back that
4238 they're no longer running. */
4239 iterate_over_lwps (ptid
, stop_wait_callback
, NULL
);
4241 /* Kill all LWP's ... */
4242 iterate_over_lwps (ptid
, kill_callback
, NULL
);
4244 /* ... and wait until we've flushed all events. */
4245 iterate_over_lwps (ptid
, kill_wait_callback
, NULL
);
4248 target_mourn_inferior ();
4252 linux_nat_mourn_inferior (struct target_ops
*ops
)
4254 purge_lwp_list (ptid_get_pid (inferior_ptid
));
4256 if (! forks_exist_p ())
4257 /* Normal case, no other forks available. */
4258 linux_ops
->to_mourn_inferior (ops
);
4260 /* Multi-fork case. The current inferior_ptid has exited, but
4261 there are other viable forks to debug. Delete the exiting
4262 one and context-switch to the first available. */
4263 linux_fork_mourn_inferior ();
4266 /* Convert a native/host siginfo object, into/from the siginfo in the
4267 layout of the inferiors' architecture. */
4270 siginfo_fixup (struct siginfo
*siginfo
, gdb_byte
*inf_siginfo
, int direction
)
4274 if (linux_nat_siginfo_fixup
!= NULL
)
4275 done
= linux_nat_siginfo_fixup (siginfo
, inf_siginfo
, direction
);
4277 /* If there was no callback, or the callback didn't do anything,
4278 then just do a straight memcpy. */
4282 memcpy (siginfo
, inf_siginfo
, sizeof (struct siginfo
));
4284 memcpy (inf_siginfo
, siginfo
, sizeof (struct siginfo
));
4289 linux_xfer_siginfo (struct target_ops
*ops
, enum target_object object
,
4290 const char *annex
, gdb_byte
*readbuf
,
4291 const gdb_byte
*writebuf
, ULONGEST offset
, LONGEST len
)
4294 struct siginfo siginfo
;
4295 gdb_byte inf_siginfo
[sizeof (struct siginfo
)];
4297 gdb_assert (object
== TARGET_OBJECT_SIGNAL_INFO
);
4298 gdb_assert (readbuf
|| writebuf
);
4300 pid
= GET_LWP (inferior_ptid
);
4302 pid
= GET_PID (inferior_ptid
);
4304 if (offset
> sizeof (siginfo
))
4308 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
4312 /* When GDB is built as a 64-bit application, ptrace writes into
4313 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
4314 inferior with a 64-bit GDB should look the same as debugging it
4315 with a 32-bit GDB, we need to convert it. GDB core always sees
4316 the converted layout, so any read/write will have to be done
4318 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
4320 if (offset
+ len
> sizeof (siginfo
))
4321 len
= sizeof (siginfo
) - offset
;
4323 if (readbuf
!= NULL
)
4324 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
4327 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
4329 /* Convert back to ptrace layout before flushing it out. */
4330 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
4333 ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
4342 linux_nat_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4343 const char *annex
, gdb_byte
*readbuf
,
4344 const gdb_byte
*writebuf
,
4345 ULONGEST offset
, LONGEST len
)
4347 struct cleanup
*old_chain
;
4350 if (object
== TARGET_OBJECT_SIGNAL_INFO
)
4351 return linux_xfer_siginfo (ops
, object
, annex
, readbuf
, writebuf
,
4354 /* The target is connected but no live inferior is selected. Pass
4355 this request down to a lower stratum (e.g., the executable
4357 if (object
== TARGET_OBJECT_MEMORY
&& ptid_equal (inferior_ptid
, null_ptid
))
4360 old_chain
= save_inferior_ptid ();
4362 if (is_lwp (inferior_ptid
))
4363 inferior_ptid
= pid_to_ptid (GET_LWP (inferior_ptid
));
4365 xfer
= linux_ops
->to_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4368 do_cleanups (old_chain
);
4373 linux_thread_alive (ptid_t ptid
)
4377 gdb_assert (is_lwp (ptid
));
4379 /* Send signal 0 instead of anything ptrace, because ptracing a
4380 running thread errors out claiming that the thread doesn't
4382 err
= kill_lwp (GET_LWP (ptid
), 0);
4384 if (debug_linux_nat
)
4385 fprintf_unfiltered (gdb_stdlog
,
4386 "LLTA: KILL(SIG0) %s (%s)\n",
4387 target_pid_to_str (ptid
),
4388 err
? safe_strerror (tmp_errno
) : "OK");
4397 linux_nat_thread_alive (struct target_ops
*ops
, ptid_t ptid
)
4399 return linux_thread_alive (ptid
);
4403 linux_nat_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
4405 static char buf
[64];
4408 && (GET_PID (ptid
) != GET_LWP (ptid
)
4409 || num_lwps (GET_PID (ptid
)) > 1))
4411 snprintf (buf
, sizeof (buf
), "LWP %ld", GET_LWP (ptid
));
4415 return normal_pid_to_str (ptid
);
4419 linux_nat_thread_name (struct thread_info
*thr
)
4421 int pid
= ptid_get_pid (thr
->ptid
);
4422 long lwp
= ptid_get_lwp (thr
->ptid
);
4423 #define FORMAT "/proc/%d/task/%ld/comm"
4424 char buf
[sizeof (FORMAT
) + 30];
4426 char *result
= NULL
;
4428 snprintf (buf
, sizeof (buf
), FORMAT
, pid
, lwp
);
4429 comm_file
= fopen (buf
, "r");
4432 /* Not exported by the kernel, so we define it here. */
4434 static char line
[COMM_LEN
+ 1];
4436 if (fgets (line
, sizeof (line
), comm_file
))
4438 char *nl
= strchr (line
, '\n');
4455 /* Accepts an integer PID; Returns a string representing a file that
4456 can be opened to get the symbols for the child process. */
4459 linux_child_pid_to_exec_file (int pid
)
4461 char *name1
, *name2
;
4463 name1
= xmalloc (MAXPATHLEN
);
4464 name2
= xmalloc (MAXPATHLEN
);
4465 make_cleanup (xfree
, name1
);
4466 make_cleanup (xfree
, name2
);
4467 memset (name2
, 0, MAXPATHLEN
);
4469 sprintf (name1
, "/proc/%d/exe", pid
);
4470 if (readlink (name1
, name2
, MAXPATHLEN
) > 0)
4476 /* Records the thread's register state for the corefile note
4480 linux_nat_collect_thread_registers (const struct regcache
*regcache
,
4481 ptid_t ptid
, bfd
*obfd
,
4482 char *note_data
, int *note_size
,
4483 enum target_signal stop_signal
)
4485 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
4486 const struct regset
*regset
;
4488 gdb_gregset_t gregs
;
4489 gdb_fpregset_t fpregs
;
4491 core_regset_p
= gdbarch_regset_from_core_section_p (gdbarch
);
4494 && (regset
= gdbarch_regset_from_core_section (gdbarch
, ".reg",
4496 != NULL
&& regset
->collect_regset
!= NULL
)
4497 regset
->collect_regset (regset
, regcache
, -1, &gregs
, sizeof (gregs
));
4499 fill_gregset (regcache
, &gregs
, -1);
4501 note_data
= (char *) elfcore_write_prstatus
4502 (obfd
, note_data
, note_size
, ptid_get_lwp (ptid
),
4503 target_signal_to_host (stop_signal
), &gregs
);
4506 && (regset
= gdbarch_regset_from_core_section (gdbarch
, ".reg2",
4508 != NULL
&& regset
->collect_regset
!= NULL
)
4509 regset
->collect_regset (regset
, regcache
, -1, &fpregs
, sizeof (fpregs
));
4511 fill_fpregset (regcache
, &fpregs
, -1);
4513 note_data
= (char *) elfcore_write_prfpreg (obfd
, note_data
, note_size
,
4514 &fpregs
, sizeof (fpregs
));
4519 /* Fills the "to_make_corefile_note" target vector. Builds the note
4520 section for a corefile, and returns it in a malloc buffer. */
4523 linux_nat_make_corefile_notes (bfd
*obfd
, int *note_size
)
4525 /* FIXME: uweigand/2011-10-06: Once all GNU/Linux architectures have been
4526 converted to gdbarch_core_regset_sections, this function can go away. */
4527 return linux_make_corefile_notes (target_gdbarch
, obfd
, note_size
,
4528 linux_nat_collect_thread_registers
);
4531 /* Implement the to_xfer_partial interface for memory reads using the /proc
4532 filesystem. Because we can use a single read() call for /proc, this
4533 can be much more efficient than banging away at PTRACE_PEEKTEXT,
4534 but it doesn't support writes. */
4537 linux_proc_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4538 const char *annex
, gdb_byte
*readbuf
,
4539 const gdb_byte
*writebuf
,
4540 ULONGEST offset
, LONGEST len
)
4546 if (object
!= TARGET_OBJECT_MEMORY
|| !readbuf
)
4549 /* Don't bother for one word. */
4550 if (len
< 3 * sizeof (long))
4553 /* We could keep this file open and cache it - possibly one per
4554 thread. That requires some juggling, but is even faster. */
4555 sprintf (filename
, "/proc/%d/mem", PIDGET (inferior_ptid
));
4556 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
4560 /* If pread64 is available, use it. It's faster if the kernel
4561 supports it (only one syscall), and it's 64-bit safe even on
4562 32-bit platforms (for instance, SPARC debugging a SPARC64
4565 if (pread64 (fd
, readbuf
, len
, offset
) != len
)
4567 if (lseek (fd
, offset
, SEEK_SET
) == -1 || read (fd
, readbuf
, len
) != len
)
4578 /* Enumerate spufs IDs for process PID. */
4580 spu_enumerate_spu_ids (int pid
, gdb_byte
*buf
, ULONGEST offset
, LONGEST len
)
4582 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch
);
4584 LONGEST written
= 0;
4587 struct dirent
*entry
;
4589 xsnprintf (path
, sizeof path
, "/proc/%d/fd", pid
);
4590 dir
= opendir (path
);
4595 while ((entry
= readdir (dir
)) != NULL
)
4601 fd
= atoi (entry
->d_name
);
4605 xsnprintf (path
, sizeof path
, "/proc/%d/fd/%d", pid
, fd
);
4606 if (stat (path
, &st
) != 0)
4608 if (!S_ISDIR (st
.st_mode
))
4611 if (statfs (path
, &stfs
) != 0)
4613 if (stfs
.f_type
!= SPUFS_MAGIC
)
4616 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4618 store_unsigned_integer (buf
+ pos
- offset
, 4, byte_order
, fd
);
4628 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4629 object type, using the /proc file system. */
4631 linux_proc_xfer_spu (struct target_ops
*ops
, enum target_object object
,
4632 const char *annex
, gdb_byte
*readbuf
,
4633 const gdb_byte
*writebuf
,
4634 ULONGEST offset
, LONGEST len
)
4639 int pid
= PIDGET (inferior_ptid
);
4646 return spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4649 xsnprintf (buf
, sizeof buf
, "/proc/%d/fd/%s", pid
, annex
);
4650 fd
= open (buf
, writebuf
? O_WRONLY
: O_RDONLY
);
4655 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4662 ret
= write (fd
, writebuf
, (size_t) len
);
4664 ret
= read (fd
, readbuf
, (size_t) len
);
4671 /* Parse LINE as a signal set and add its set bits to SIGS. */
4674 add_line_to_sigset (const char *line
, sigset_t
*sigs
)
4676 int len
= strlen (line
) - 1;
4680 if (line
[len
] != '\n')
4681 error (_("Could not parse signal set: %s"), line
);
4689 if (*p
>= '0' && *p
<= '9')
4691 else if (*p
>= 'a' && *p
<= 'f')
4692 digit
= *p
- 'a' + 10;
4694 error (_("Could not parse signal set: %s"), line
);
4699 sigaddset (sigs
, signum
+ 1);
4701 sigaddset (sigs
, signum
+ 2);
4703 sigaddset (sigs
, signum
+ 3);
4705 sigaddset (sigs
, signum
+ 4);
4711 /* Find process PID's pending signals from /proc/pid/status and set
4715 linux_proc_pending_signals (int pid
, sigset_t
*pending
,
4716 sigset_t
*blocked
, sigset_t
*ignored
)
4719 char buffer
[MAXPATHLEN
], fname
[MAXPATHLEN
];
4720 struct cleanup
*cleanup
;
4722 sigemptyset (pending
);
4723 sigemptyset (blocked
);
4724 sigemptyset (ignored
);
4725 sprintf (fname
, "/proc/%d/status", pid
);
4726 procfile
= fopen (fname
, "r");
4727 if (procfile
== NULL
)
4728 error (_("Could not open %s"), fname
);
4729 cleanup
= make_cleanup_fclose (procfile
);
4731 while (fgets (buffer
, MAXPATHLEN
, procfile
) != NULL
)
4733 /* Normal queued signals are on the SigPnd line in the status
4734 file. However, 2.6 kernels also have a "shared" pending
4735 queue for delivering signals to a thread group, so check for
4738 Unfortunately some Red Hat kernels include the shared pending
4739 queue but not the ShdPnd status field. */
4741 if (strncmp (buffer
, "SigPnd:\t", 8) == 0)
4742 add_line_to_sigset (buffer
+ 8, pending
);
4743 else if (strncmp (buffer
, "ShdPnd:\t", 8) == 0)
4744 add_line_to_sigset (buffer
+ 8, pending
);
4745 else if (strncmp (buffer
, "SigBlk:\t", 8) == 0)
4746 add_line_to_sigset (buffer
+ 8, blocked
);
4747 else if (strncmp (buffer
, "SigIgn:\t", 8) == 0)
4748 add_line_to_sigset (buffer
+ 8, ignored
);
4751 do_cleanups (cleanup
);
4755 linux_nat_xfer_osdata (struct target_ops
*ops
, enum target_object object
,
4756 const char *annex
, gdb_byte
*readbuf
,
4757 const gdb_byte
*writebuf
, ULONGEST offset
, LONGEST len
)
4759 gdb_assert (object
== TARGET_OBJECT_OSDATA
);
4761 return linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
4765 linux_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4766 const char *annex
, gdb_byte
*readbuf
,
4767 const gdb_byte
*writebuf
, ULONGEST offset
, LONGEST len
)
4771 if (object
== TARGET_OBJECT_AUXV
)
4772 return memory_xfer_auxv (ops
, object
, annex
, readbuf
, writebuf
,
4775 if (object
== TARGET_OBJECT_OSDATA
)
4776 return linux_nat_xfer_osdata (ops
, object
, annex
, readbuf
, writebuf
,
4779 if (object
== TARGET_OBJECT_SPU
)
4780 return linux_proc_xfer_spu (ops
, object
, annex
, readbuf
, writebuf
,
4783 /* GDB calculates all the addresses in possibly larget width of the address.
4784 Address width needs to be masked before its final use - either by
4785 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4787 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4789 if (object
== TARGET_OBJECT_MEMORY
)
4791 int addr_bit
= gdbarch_addr_bit (target_gdbarch
);
4793 if (addr_bit
< (sizeof (ULONGEST
) * HOST_CHAR_BIT
))
4794 offset
&= ((ULONGEST
) 1 << addr_bit
) - 1;
4797 xfer
= linux_proc_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4802 return super_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4806 /* Create a prototype generic GNU/Linux target. The client can override
4807 it with local methods. */
4810 linux_target_install_ops (struct target_ops
*t
)
4812 t
->to_insert_fork_catchpoint
= linux_child_insert_fork_catchpoint
;
4813 t
->to_remove_fork_catchpoint
= linux_child_remove_fork_catchpoint
;
4814 t
->to_insert_vfork_catchpoint
= linux_child_insert_vfork_catchpoint
;
4815 t
->to_remove_vfork_catchpoint
= linux_child_remove_vfork_catchpoint
;
4816 t
->to_insert_exec_catchpoint
= linux_child_insert_exec_catchpoint
;
4817 t
->to_remove_exec_catchpoint
= linux_child_remove_exec_catchpoint
;
4818 t
->to_set_syscall_catchpoint
= linux_child_set_syscall_catchpoint
;
4819 t
->to_pid_to_exec_file
= linux_child_pid_to_exec_file
;
4820 t
->to_post_startup_inferior
= linux_child_post_startup_inferior
;
4821 t
->to_post_attach
= linux_child_post_attach
;
4822 t
->to_follow_fork
= linux_child_follow_fork
;
4823 t
->to_make_corefile_notes
= linux_nat_make_corefile_notes
;
4825 super_xfer_partial
= t
->to_xfer_partial
;
4826 t
->to_xfer_partial
= linux_xfer_partial
;
4832 struct target_ops
*t
;
4834 t
= inf_ptrace_target ();
4835 linux_target_install_ops (t
);
4841 linux_trad_target (CORE_ADDR (*register_u_offset
)(struct gdbarch
*, int, int))
4843 struct target_ops
*t
;
4845 t
= inf_ptrace_trad_target (register_u_offset
);
4846 linux_target_install_ops (t
);
4851 /* target_is_async_p implementation. */
4854 linux_nat_is_async_p (void)
4856 /* NOTE: palves 2008-03-21: We're only async when the user requests
4857 it explicitly with the "set target-async" command.
4858 Someday, linux will always be async. */
4859 return target_async_permitted
;
4862 /* target_can_async_p implementation. */
4865 linux_nat_can_async_p (void)
4867 /* NOTE: palves 2008-03-21: We're only async when the user requests
4868 it explicitly with the "set target-async" command.
4869 Someday, linux will always be async. */
4870 return target_async_permitted
;
4874 linux_nat_supports_non_stop (void)
4879 /* True if we want to support multi-process. To be removed when GDB
4880 supports multi-exec. */
4882 int linux_multi_process
= 1;
4885 linux_nat_supports_multi_process (void)
4887 return linux_multi_process
;
4891 linux_nat_supports_disable_randomization (void)
4893 #ifdef HAVE_PERSONALITY
4900 static int async_terminal_is_ours
= 1;
4902 /* target_terminal_inferior implementation. */
4905 linux_nat_terminal_inferior (void)
4907 if (!target_is_async_p ())
4909 /* Async mode is disabled. */
4910 terminal_inferior ();
4914 terminal_inferior ();
4916 /* Calls to target_terminal_*() are meant to be idempotent. */
4917 if (!async_terminal_is_ours
)
4920 delete_file_handler (input_fd
);
4921 async_terminal_is_ours
= 0;
4925 /* target_terminal_ours implementation. */
4928 linux_nat_terminal_ours (void)
4930 if (!target_is_async_p ())
4932 /* Async mode is disabled. */
4937 /* GDB should never give the terminal to the inferior if the
4938 inferior is running in the background (run&, continue&, etc.),
4939 but claiming it sure should. */
4942 if (async_terminal_is_ours
)
4945 clear_sigint_trap ();
4946 add_file_handler (input_fd
, stdin_event_handler
, 0);
4947 async_terminal_is_ours
= 1;
4950 static void (*async_client_callback
) (enum inferior_event_type event_type
,
4952 static void *async_client_context
;
4954 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4955 so we notice when any child changes state, and notify the
4956 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4957 above to wait for the arrival of a SIGCHLD. */
4960 sigchld_handler (int signo
)
4962 int old_errno
= errno
;
4964 if (debug_linux_nat
)
4965 ui_file_write_async_safe (gdb_stdlog
,
4966 "sigchld\n", sizeof ("sigchld\n") - 1);
4968 if (signo
== SIGCHLD
4969 && linux_nat_event_pipe
[0] != -1)
4970 async_file_mark (); /* Let the event loop know that there are
4971 events to handle. */
4976 /* Callback registered with the target events file descriptor. */
4979 handle_target_event (int error
, gdb_client_data client_data
)
4981 (*async_client_callback
) (INF_REG_EVENT
, async_client_context
);
4984 /* Create/destroy the target events pipe. Returns previous state. */
4987 linux_async_pipe (int enable
)
4989 int previous
= (linux_nat_event_pipe
[0] != -1);
4991 if (previous
!= enable
)
4995 block_child_signals (&prev_mask
);
4999 if (pipe (linux_nat_event_pipe
) == -1)
5000 internal_error (__FILE__
, __LINE__
,
5001 "creating event pipe failed.");
5003 fcntl (linux_nat_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
5004 fcntl (linux_nat_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
5008 close (linux_nat_event_pipe
[0]);
5009 close (linux_nat_event_pipe
[1]);
5010 linux_nat_event_pipe
[0] = -1;
5011 linux_nat_event_pipe
[1] = -1;
5014 restore_child_signals_mask (&prev_mask
);
5020 /* target_async implementation. */
5023 linux_nat_async (void (*callback
) (enum inferior_event_type event_type
,
5024 void *context
), void *context
)
5026 if (callback
!= NULL
)
5028 async_client_callback
= callback
;
5029 async_client_context
= context
;
5030 if (!linux_async_pipe (1))
5032 add_file_handler (linux_nat_event_pipe
[0],
5033 handle_target_event
, NULL
);
5034 /* There may be pending events to handle. Tell the event loop
5041 async_client_callback
= callback
;
5042 async_client_context
= context
;
5043 delete_file_handler (linux_nat_event_pipe
[0]);
5044 linux_async_pipe (0);
5049 /* Stop an LWP, and push a TARGET_SIGNAL_0 stop status if no other
5053 linux_nat_stop_lwp (struct lwp_info
*lwp
, void *data
)
5057 ptid_t ptid
= lwp
->ptid
;
5059 if (debug_linux_nat
)
5060 fprintf_unfiltered (gdb_stdlog
,
5061 "LNSL: running -> suspending %s\n",
5062 target_pid_to_str (lwp
->ptid
));
5065 if (lwp
->last_resume_kind
== resume_stop
)
5067 if (debug_linux_nat
)
5068 fprintf_unfiltered (gdb_stdlog
,
5069 "linux-nat: already stopping LWP %ld at "
5071 ptid_get_lwp (lwp
->ptid
));
5075 stop_callback (lwp
, NULL
);
5076 lwp
->last_resume_kind
= resume_stop
;
5080 /* Already known to be stopped; do nothing. */
5082 if (debug_linux_nat
)
5084 if (find_thread_ptid (lwp
->ptid
)->stop_requested
)
5085 fprintf_unfiltered (gdb_stdlog
,
5086 "LNSL: already stopped/stop_requested %s\n",
5087 target_pid_to_str (lwp
->ptid
));
5089 fprintf_unfiltered (gdb_stdlog
,
5090 "LNSL: already stopped/no "
5091 "stop_requested yet %s\n",
5092 target_pid_to_str (lwp
->ptid
));
5099 linux_nat_stop (ptid_t ptid
)
5102 iterate_over_lwps (ptid
, linux_nat_stop_lwp
, NULL
);
5104 linux_ops
->to_stop (ptid
);
5108 linux_nat_close (int quitting
)
5110 /* Unregister from the event loop. */
5111 if (linux_nat_is_async_p ())
5112 linux_nat_async (NULL
, 0);
5114 if (linux_ops
->to_close
)
5115 linux_ops
->to_close (quitting
);
5118 /* When requests are passed down from the linux-nat layer to the
5119 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
5120 used. The address space pointer is stored in the inferior object,
5121 but the common code that is passed such ptid can't tell whether
5122 lwpid is a "main" process id or not (it assumes so). We reverse
5123 look up the "main" process id from the lwp here. */
5125 struct address_space
*
5126 linux_nat_thread_address_space (struct target_ops
*t
, ptid_t ptid
)
5128 struct lwp_info
*lwp
;
5129 struct inferior
*inf
;
5132 pid
= GET_LWP (ptid
);
5133 if (GET_LWP (ptid
) == 0)
5135 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
5137 lwp
= find_lwp_pid (ptid
);
5138 pid
= GET_PID (lwp
->ptid
);
5142 /* A (pid,lwpid,0) ptid. */
5143 pid
= GET_PID (ptid
);
5146 inf
= find_inferior_pid (pid
);
5147 gdb_assert (inf
!= NULL
);
5152 linux_nat_core_of_thread_1 (ptid_t ptid
)
5154 struct cleanup
*back_to
;
5157 char *content
= NULL
;
5160 int content_read
= 0;
5164 filename
= xstrprintf ("/proc/%d/task/%ld/stat",
5165 GET_PID (ptid
), GET_LWP (ptid
));
5166 back_to
= make_cleanup (xfree
, filename
);
5168 f
= fopen (filename
, "r");
5171 do_cleanups (back_to
);
5175 make_cleanup_fclose (f
);
5181 content
= xrealloc (content
, content_read
+ 1024);
5182 n
= fread (content
+ content_read
, 1, 1024, f
);
5186 content
[content_read
] = '\0';
5191 make_cleanup (xfree
, content
);
5193 p
= strchr (content
, '(');
5197 p
= strchr (p
, ')');
5201 /* If the first field after program name has index 0, then core number is
5202 the field with index 36. There's no constant for that anywhere. */
5204 p
= strtok_r (p
, " ", &ts
);
5205 for (i
= 0; p
!= NULL
&& i
!= 36; ++i
)
5206 p
= strtok_r (NULL
, " ", &ts
);
5208 if (p
== NULL
|| sscanf (p
, "%d", &core
) == 0)
5211 do_cleanups (back_to
);
5216 /* Return the cached value of the processor core for thread PTID. */
5219 linux_nat_core_of_thread (struct target_ops
*ops
, ptid_t ptid
)
5221 struct lwp_info
*info
= find_lwp_pid (ptid
);
5229 linux_nat_add_target (struct target_ops
*t
)
5231 /* Save the provided single-threaded target. We save this in a separate
5232 variable because another target we've inherited from (e.g. inf-ptrace)
5233 may have saved a pointer to T; we want to use it for the final
5234 process stratum target. */
5235 linux_ops_saved
= *t
;
5236 linux_ops
= &linux_ops_saved
;
5238 /* Override some methods for multithreading. */
5239 t
->to_create_inferior
= linux_nat_create_inferior
;
5240 t
->to_attach
= linux_nat_attach
;
5241 t
->to_detach
= linux_nat_detach
;
5242 t
->to_resume
= linux_nat_resume
;
5243 t
->to_wait
= linux_nat_wait
;
5244 t
->to_pass_signals
= linux_nat_pass_signals
;
5245 t
->to_xfer_partial
= linux_nat_xfer_partial
;
5246 t
->to_kill
= linux_nat_kill
;
5247 t
->to_mourn_inferior
= linux_nat_mourn_inferior
;
5248 t
->to_thread_alive
= linux_nat_thread_alive
;
5249 t
->to_pid_to_str
= linux_nat_pid_to_str
;
5250 t
->to_thread_name
= linux_nat_thread_name
;
5251 t
->to_has_thread_control
= tc_schedlock
;
5252 t
->to_thread_address_space
= linux_nat_thread_address_space
;
5253 t
->to_stopped_by_watchpoint
= linux_nat_stopped_by_watchpoint
;
5254 t
->to_stopped_data_address
= linux_nat_stopped_data_address
;
5256 t
->to_can_async_p
= linux_nat_can_async_p
;
5257 t
->to_is_async_p
= linux_nat_is_async_p
;
5258 t
->to_supports_non_stop
= linux_nat_supports_non_stop
;
5259 t
->to_async
= linux_nat_async
;
5260 t
->to_terminal_inferior
= linux_nat_terminal_inferior
;
5261 t
->to_terminal_ours
= linux_nat_terminal_ours
;
5262 t
->to_close
= linux_nat_close
;
5264 /* Methods for non-stop support. */
5265 t
->to_stop
= linux_nat_stop
;
5267 t
->to_supports_multi_process
= linux_nat_supports_multi_process
;
5269 t
->to_supports_disable_randomization
5270 = linux_nat_supports_disable_randomization
;
5272 t
->to_core_of_thread
= linux_nat_core_of_thread
;
5274 /* We don't change the stratum; this target will sit at
5275 process_stratum and thread_db will set at thread_stratum. This
5276 is a little strange, since this is a multi-threaded-capable
5277 target, but we want to be on the stack below thread_db, and we
5278 also want to be used for single-threaded processes. */
5283 /* Register a method to call whenever a new thread is attached. */
5285 linux_nat_set_new_thread (struct target_ops
*t
,
5286 void (*new_thread
) (struct lwp_info
*))
5288 /* Save the pointer. We only support a single registered instance
5289 of the GNU/Linux native target, so we do not need to map this to
5291 linux_nat_new_thread
= new_thread
;
5294 /* Register a method that converts a siginfo object between the layout
5295 that ptrace returns, and the layout in the architecture of the
5298 linux_nat_set_siginfo_fixup (struct target_ops
*t
,
5299 int (*siginfo_fixup
) (struct siginfo
*,
5303 /* Save the pointer. */
5304 linux_nat_siginfo_fixup
= siginfo_fixup
;
5307 /* Register a method to call prior to resuming a thread. */
5310 linux_nat_set_prepare_to_resume (struct target_ops
*t
,
5311 void (*prepare_to_resume
) (struct lwp_info
*))
5313 /* Save the pointer. */
5314 linux_nat_prepare_to_resume
= prepare_to_resume
;
5317 /* Return the saved siginfo associated with PTID. */
5319 linux_nat_get_siginfo (ptid_t ptid
)
5321 struct lwp_info
*lp
= find_lwp_pid (ptid
);
5323 gdb_assert (lp
!= NULL
);
5325 return &lp
->siginfo
;
5328 /* Provide a prototype to silence -Wmissing-prototypes. */
5329 extern initialize_file_ftype _initialize_linux_nat
;
5332 _initialize_linux_nat (void)
5334 add_setshow_zinteger_cmd ("lin-lwp", class_maintenance
,
5335 &debug_linux_nat
, _("\
5336 Set debugging of GNU/Linux lwp module."), _("\
5337 Show debugging of GNU/Linux lwp module."), _("\
5338 Enables printf debugging output."),
5340 show_debug_linux_nat
,
5341 &setdebuglist
, &showdebuglist
);
5343 /* Save this mask as the default. */
5344 sigprocmask (SIG_SETMASK
, NULL
, &normal_mask
);
5346 /* Install a SIGCHLD handler. */
5347 sigchld_action
.sa_handler
= sigchld_handler
;
5348 sigemptyset (&sigchld_action
.sa_mask
);
5349 sigchld_action
.sa_flags
= SA_RESTART
;
5351 /* Make it the default. */
5352 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
5354 /* Make sure we don't block SIGCHLD during a sigsuspend. */
5355 sigprocmask (SIG_SETMASK
, NULL
, &suspend_mask
);
5356 sigdelset (&suspend_mask
, SIGCHLD
);
5358 sigemptyset (&blocked_mask
);
5362 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
5363 the GNU/Linux Threads library and therefore doesn't really belong
5366 /* Read variable NAME in the target and return its value if found.
5367 Otherwise return zero. It is assumed that the type of the variable
5371 get_signo (const char *name
)
5373 struct minimal_symbol
*ms
;
5376 ms
= lookup_minimal_symbol (name
, NULL
, NULL
);
5380 if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms
), (gdb_byte
*) &signo
,
5381 sizeof (signo
)) != 0)
5387 /* Return the set of signals used by the threads library in *SET. */
5390 lin_thread_get_thread_signals (sigset_t
*set
)
5392 struct sigaction action
;
5393 int restart
, cancel
;
5395 sigemptyset (&blocked_mask
);
5398 restart
= get_signo ("__pthread_sig_restart");
5399 cancel
= get_signo ("__pthread_sig_cancel");
5401 /* LinuxThreads normally uses the first two RT signals, but in some legacy
5402 cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
5403 not provide any way for the debugger to query the signal numbers -
5404 fortunately they don't change! */
5407 restart
= __SIGRTMIN
;
5410 cancel
= __SIGRTMIN
+ 1;
5412 sigaddset (set
, restart
);
5413 sigaddset (set
, cancel
);
5415 /* The GNU/Linux Threads library makes terminating threads send a
5416 special "cancel" signal instead of SIGCHLD. Make sure we catch
5417 those (to prevent them from terminating GDB itself, which is
5418 likely to be their default action) and treat them the same way as
5421 action
.sa_handler
= sigchld_handler
;
5422 sigemptyset (&action
.sa_mask
);
5423 action
.sa_flags
= SA_RESTART
;
5424 sigaction (cancel
, &action
, NULL
);
5426 /* We block the "cancel" signal throughout this code ... */
5427 sigaddset (&blocked_mask
, cancel
);
5428 sigprocmask (SIG_BLOCK
, &blocked_mask
, NULL
);
5430 /* ... except during a sigsuspend. */
5431 sigdelset (&suspend_mask
, cancel
);