1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
4 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "gdb_string.h"
26 #include "gdb_assert.h"
27 #ifdef HAVE_TKILL_SYSCALL
29 #include <sys/syscall.h>
31 #include <sys/ptrace.h>
32 #include "linux-nat.h"
33 #include "linux-fork.h"
34 #include "gdbthread.h"
38 #include "inf-ptrace.h"
40 #include <sys/param.h> /* for MAXPATHLEN */
41 #include <sys/procfs.h> /* for elf_gregset etc. */
42 #include "elf-bfd.h" /* for elfcore_write_* */
43 #include "gregset.h" /* for gregset */
44 #include "gdbcore.h" /* for get_exec_file */
45 #include <ctype.h> /* for isdigit */
46 #include "gdbthread.h" /* for struct thread_info etc. */
47 #include "gdb_stat.h" /* for struct stat */
48 #include <fcntl.h> /* for O_RDONLY */
50 #include "event-loop.h"
51 #include "event-top.h"
53 #ifdef HAVE_PERSONALITY
54 # include <sys/personality.h>
55 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
56 # define ADDR_NO_RANDOMIZE 0x0040000
58 #endif /* HAVE_PERSONALITY */
60 /* This comment documents high-level logic of this file.
62 Waiting for events in sync mode
63 ===============================
65 When waiting for an event in a specific thread, we just use waitpid, passing
66 the specific pid, and not passing WNOHANG.
68 When waiting for an event in all threads, waitpid is not quite good. Prior to
69 version 2.4, Linux can either wait for event in main thread, or in secondary
70 threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might
71 miss an event. The solution is to use non-blocking waitpid, together with
72 sigsuspend. First, we use non-blocking waitpid to get an event in the main
73 process, if any. Second, we use non-blocking waitpid with the __WCLONED
74 flag to check for events in cloned processes. If nothing is found, we use
75 sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something
76 happened to a child process -- and SIGCHLD will be delivered both for events
77 in main debugged process and in cloned processes. As soon as we know there's
78 an event, we get back to calling nonblocking waitpid with and without __WCLONED.
80 Note that SIGCHLD should be blocked between waitpid and sigsuspend calls,
81 so that we don't miss a signal. If SIGCHLD arrives in between, when it's
82 blocked, the signal becomes pending and sigsuspend immediately
83 notices it and returns.
85 Waiting for events in async mode
86 ================================
88 In async mode, GDB should always be ready to handle both user input and target
89 events, so neither blocking waitpid nor sigsuspend are viable
90 options. Instead, we should notify the GDB main event loop whenever there's
91 unprocessed event from the target. The only way to notify this event loop is
92 to make it wait on input from a pipe, and write something to the pipe whenever
93 there's event. Obviously, if we fail to notify the event loop if there's
94 target event, it's bad. If we notify the event loop when there's no event
95 from target, linux-nat.c will detect that there's no event, actually, and
96 report event of type TARGET_WAITKIND_IGNORE, but it will waste time and
99 The main design point is that every time GDB is outside linux-nat.c, we have a
100 SIGCHLD handler installed that is called when something happens to the target
101 and notifies the GDB event loop. Also, the event is extracted from the target
102 using waitpid and stored for future use. Whenever GDB core decides to handle
103 the event, and calls into linux-nat.c, we disable SIGCHLD and process things
104 as in sync mode, except that before waitpid call we check if there are any
105 previously read events.
107 It could happen that during event processing, we'll try to get more events
108 than there are events in the local queue, which will result to waitpid call.
109 Those waitpid calls, while blocking, are guarantied to always have
110 something for waitpid to return. E.g., stopping a thread with SIGSTOP, and
111 waiting for the lwp to stop.
113 The event loop is notified about new events using a pipe. SIGCHLD handler does
114 waitpid and writes the results in to a pipe. GDB event loop has the other end
115 of the pipe among the sources. When event loop starts to process the event
116 and calls a function in linux-nat.c, all events from the pipe are transferred
117 into a local queue and SIGCHLD is blocked. Further processing goes as in sync
118 mode. Before we return from linux_nat_wait, we transfer all unprocessed events
119 from local queue back to the pipe, so that when we get back to event loop,
120 event loop will notice there's something more to do.
122 SIGCHLD is blocked when we're inside target_wait, so that should we actually
123 want to wait for some more events, SIGCHLD handler does not steal them from
124 us. Technically, it would be possible to add new events to the local queue but
125 it's about the same amount of work as blocking SIGCHLD.
127 This moving of events from pipe into local queue and back into pipe when we
128 enter/leave linux-nat.c is somewhat ugly. Unfortunately, GDB event loop is
129 home-grown and incapable to wait on any queue.
134 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
135 signal is not entirely significant; we just need for a signal to be delivered,
136 so that we can intercept it. SIGSTOP's advantage is that it can not be
137 blocked. A disadvantage is that it is not a real-time signal, so it can only
138 be queued once; we do not keep track of other sources of SIGSTOP.
140 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
141 use them, because they have special behavior when the signal is generated -
142 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
143 kills the entire thread group.
145 A delivered SIGSTOP would stop the entire thread group, not just the thread we
146 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
147 cancel it (by PTRACE_CONT without passing SIGSTOP).
149 We could use a real-time signal instead. This would solve those problems; we
150 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
151 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
152 generates it, and there are races with trying to find a signal that is not
156 #define O_LARGEFILE 0
159 /* If the system headers did not provide the constants, hard-code the normal
161 #ifndef PTRACE_EVENT_FORK
163 #define PTRACE_SETOPTIONS 0x4200
164 #define PTRACE_GETEVENTMSG 0x4201
166 /* options set using PTRACE_SETOPTIONS */
167 #define PTRACE_O_TRACESYSGOOD 0x00000001
168 #define PTRACE_O_TRACEFORK 0x00000002
169 #define PTRACE_O_TRACEVFORK 0x00000004
170 #define PTRACE_O_TRACECLONE 0x00000008
171 #define PTRACE_O_TRACEEXEC 0x00000010
172 #define PTRACE_O_TRACEVFORKDONE 0x00000020
173 #define PTRACE_O_TRACEEXIT 0x00000040
175 /* Wait extended result codes for the above trace options. */
176 #define PTRACE_EVENT_FORK 1
177 #define PTRACE_EVENT_VFORK 2
178 #define PTRACE_EVENT_CLONE 3
179 #define PTRACE_EVENT_EXEC 4
180 #define PTRACE_EVENT_VFORK_DONE 5
181 #define PTRACE_EVENT_EXIT 6
183 #endif /* PTRACE_EVENT_FORK */
185 /* We can't always assume that this flag is available, but all systems
186 with the ptrace event handlers also have __WALL, so it's safe to use
189 #define __WALL 0x40000000 /* Wait for any child. */
192 #ifndef PTRACE_GETSIGINFO
193 #define PTRACE_GETSIGINFO 0x4202
196 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
197 the use of the multi-threaded target. */
198 static struct target_ops
*linux_ops
;
199 static struct target_ops linux_ops_saved
;
201 /* The method to call, if any, when a new thread is attached. */
202 static void (*linux_nat_new_thread
) (ptid_t
);
204 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
205 Called by our to_xfer_partial. */
206 static LONGEST (*super_xfer_partial
) (struct target_ops
*,
208 const char *, gdb_byte
*,
212 static int debug_linux_nat
;
214 show_debug_linux_nat (struct ui_file
*file
, int from_tty
,
215 struct cmd_list_element
*c
, const char *value
)
217 fprintf_filtered (file
, _("Debugging of GNU/Linux lwp module is %s.\n"),
221 static int debug_linux_nat_async
= 0;
223 show_debug_linux_nat_async (struct ui_file
*file
, int from_tty
,
224 struct cmd_list_element
*c
, const char *value
)
226 fprintf_filtered (file
, _("Debugging of GNU/Linux async lwp module is %s.\n"),
230 static int disable_randomization
= 1;
233 show_disable_randomization (struct ui_file
*file
, int from_tty
,
234 struct cmd_list_element
*c
, const char *value
)
236 #ifdef HAVE_PERSONALITY
237 fprintf_filtered (file
, _("\
238 Disabling randomization of debuggee's virtual address space is %s.\n"),
240 #else /* !HAVE_PERSONALITY */
242 Disabling randomization of debuggee's virtual address space is unsupported on\n\
243 this platform.\n"), file
);
244 #endif /* !HAVE_PERSONALITY */
248 set_disable_randomization (char *args
, int from_tty
, struct cmd_list_element
*c
)
250 #ifndef HAVE_PERSONALITY
252 Disabling randomization of debuggee's virtual address space is unsupported on\n\
254 #endif /* !HAVE_PERSONALITY */
257 static int linux_parent_pid
;
259 struct simple_pid_list
263 struct simple_pid_list
*next
;
265 struct simple_pid_list
*stopped_pids
;
267 /* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACEFORK
268 can not be used, 1 if it can. */
270 static int linux_supports_tracefork_flag
= -1;
272 /* If we have PTRACE_O_TRACEFORK, this flag indicates whether we also have
273 PTRACE_O_TRACEVFORKDONE. */
275 static int linux_supports_tracevforkdone_flag
= -1;
277 /* Async mode support */
279 /* Zero if the async mode, although enabled, is masked, which means
280 linux_nat_wait should behave as if async mode was off. */
281 static int linux_nat_async_mask_value
= 1;
283 /* The read/write ends of the pipe registered as waitable file in the
285 static int linux_nat_event_pipe
[2] = { -1, -1 };
287 /* Number of queued events in the pipe. */
288 static volatile int linux_nat_num_queued_events
;
290 /* The possible SIGCHLD handling states. */
294 /* SIGCHLD disabled, with action set to sigchld_handler, for the
295 sigsuspend in linux_nat_wait. */
297 /* SIGCHLD enabled, with action set to async_sigchld_handler. */
299 /* Set SIGCHLD to default action. Used while creating an
304 /* The current SIGCHLD handling state. */
305 static enum sigchld_state linux_nat_async_events_state
;
307 static enum sigchld_state
linux_nat_async_events (enum sigchld_state enable
);
308 static void pipe_to_local_event_queue (void);
309 static void local_event_queue_to_pipe (void);
310 static void linux_nat_event_pipe_push (int pid
, int status
, int options
);
311 static int linux_nat_event_pipe_pop (int* ptr_status
, int* ptr_options
);
312 static void linux_nat_set_async_mode (int on
);
313 static void linux_nat_async (void (*callback
)
314 (enum inferior_event_type event_type
, void *context
),
316 static int linux_nat_async_mask (int mask
);
317 static int kill_lwp (int lwpid
, int signo
);
319 static int stop_callback (struct lwp_info
*lp
, void *data
);
321 /* Captures the result of a successful waitpid call, along with the
322 options used in that call. */
323 struct waitpid_result
328 struct waitpid_result
*next
;
331 /* A singly-linked list of the results of the waitpid calls performed
332 in the async SIGCHLD handler. */
333 static struct waitpid_result
*waitpid_queue
= NULL
;
335 /* Similarly to `waitpid', but check the local event queue instead of
336 querying the kernel queue. If PEEK, don't remove the event found
340 queued_waitpid_1 (int pid
, int *status
, int flags
, int peek
)
342 struct waitpid_result
*msg
= waitpid_queue
, *prev
= NULL
;
344 if (debug_linux_nat_async
)
345 fprintf_unfiltered (gdb_stdlog
,
347 QWPID: linux_nat_async_events_state(%d), linux_nat_num_queued_events(%d)\n",
348 linux_nat_async_events_state
,
349 linux_nat_num_queued_events
);
353 for (; msg
; prev
= msg
, msg
= msg
->next
)
354 if (pid
== -1 || pid
== msg
->pid
)
357 else if (flags
& __WCLONE
)
359 for (; msg
; prev
= msg
, msg
= msg
->next
)
360 if (msg
->options
& __WCLONE
361 && (pid
== -1 || pid
== msg
->pid
))
366 for (; msg
; prev
= msg
, msg
= msg
->next
)
367 if ((msg
->options
& __WCLONE
) == 0
368 && (pid
== -1 || pid
== msg
->pid
))
377 *status
= msg
->status
;
380 if (debug_linux_nat_async
)
381 fprintf_unfiltered (gdb_stdlog
, "QWPID: pid(%d), status(%x)\n",
387 prev
->next
= msg
->next
;
389 waitpid_queue
= msg
->next
;
398 if (debug_linux_nat_async
)
399 fprintf_unfiltered (gdb_stdlog
, "QWPID: miss\n");
406 /* Similarly to `waitpid', but check the local event queue. */
409 queued_waitpid (int pid
, int *status
, int flags
)
411 return queued_waitpid_1 (pid
, status
, flags
, 0);
415 push_waitpid (int pid
, int status
, int options
)
417 struct waitpid_result
*event
, *new_event
;
419 new_event
= xmalloc (sizeof (*new_event
));
420 new_event
->pid
= pid
;
421 new_event
->status
= status
;
422 new_event
->options
= options
;
423 new_event
->next
= NULL
;
427 for (event
= waitpid_queue
;
428 event
&& event
->next
;
432 event
->next
= new_event
;
435 waitpid_queue
= new_event
;
438 /* Drain all queued events of PID. If PID is -1, the effect is of
439 draining all events. */
441 drain_queued_events (int pid
)
443 while (queued_waitpid (pid
, NULL
, __WALL
) != -1)
448 /* Trivial list manipulation functions to keep track of a list of
449 new stopped processes. */
451 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
453 struct simple_pid_list
*new_pid
= xmalloc (sizeof (struct simple_pid_list
));
455 new_pid
->status
= status
;
456 new_pid
->next
= *listp
;
461 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *status
)
463 struct simple_pid_list
**p
;
465 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
466 if ((*p
)->pid
== pid
)
468 struct simple_pid_list
*next
= (*p
)->next
;
469 *status
= (*p
)->status
;
478 linux_record_stopped_pid (int pid
, int status
)
480 add_to_pid_list (&stopped_pids
, pid
, status
);
484 /* A helper function for linux_test_for_tracefork, called after fork (). */
487 linux_tracefork_child (void)
491 ptrace (PTRACE_TRACEME
, 0, 0, 0);
492 kill (getpid (), SIGSTOP
);
497 /* Wrapper function for waitpid which handles EINTR, and checks for
498 locally queued events. */
501 my_waitpid (int pid
, int *status
, int flags
)
505 /* There should be no concurrent calls to waitpid. */
506 gdb_assert (linux_nat_async_events_state
== sigchld_sync
);
508 ret
= queued_waitpid (pid
, status
, flags
);
514 ret
= waitpid (pid
, status
, flags
);
516 while (ret
== -1 && errno
== EINTR
);
521 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events.
523 First, we try to enable fork tracing on ORIGINAL_PID. If this fails,
524 we know that the feature is not available. This may change the tracing
525 options for ORIGINAL_PID, but we'll be setting them shortly anyway.
527 However, if it succeeds, we don't know for sure that the feature is
528 available; old versions of PTRACE_SETOPTIONS ignored unknown options. We
529 create a child process, attach to it, use PTRACE_SETOPTIONS to enable
530 fork tracing, and let it fork. If the process exits, we assume that we
531 can't use TRACEFORK; if we get the fork notification, and we can extract
532 the new child's PID, then we assume that we can. */
535 linux_test_for_tracefork (int original_pid
)
537 int child_pid
, ret
, status
;
539 enum sigchld_state async_events_original_state
;
541 async_events_original_state
= linux_nat_async_events (sigchld_sync
);
543 linux_supports_tracefork_flag
= 0;
544 linux_supports_tracevforkdone_flag
= 0;
546 ret
= ptrace (PTRACE_SETOPTIONS
, original_pid
, 0, PTRACE_O_TRACEFORK
);
552 perror_with_name (("fork"));
555 linux_tracefork_child ();
557 ret
= my_waitpid (child_pid
, &status
, 0);
559 perror_with_name (("waitpid"));
560 else if (ret
!= child_pid
)
561 error (_("linux_test_for_tracefork: waitpid: unexpected result %d."), ret
);
562 if (! WIFSTOPPED (status
))
563 error (_("linux_test_for_tracefork: waitpid: unexpected status %d."), status
);
565 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0, PTRACE_O_TRACEFORK
);
568 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
571 warning (_("linux_test_for_tracefork: failed to kill child"));
572 linux_nat_async_events (async_events_original_state
);
576 ret
= my_waitpid (child_pid
, &status
, 0);
577 if (ret
!= child_pid
)
578 warning (_("linux_test_for_tracefork: failed to wait for killed child"));
579 else if (!WIFSIGNALED (status
))
580 warning (_("linux_test_for_tracefork: unexpected wait status 0x%x from "
581 "killed child"), status
);
583 linux_nat_async_events (async_events_original_state
);
587 /* Check whether PTRACE_O_TRACEVFORKDONE is available. */
588 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0,
589 PTRACE_O_TRACEFORK
| PTRACE_O_TRACEVFORKDONE
);
590 linux_supports_tracevforkdone_flag
= (ret
== 0);
592 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
594 warning (_("linux_test_for_tracefork: failed to resume child"));
596 ret
= my_waitpid (child_pid
, &status
, 0);
598 if (ret
== child_pid
&& WIFSTOPPED (status
)
599 && status
>> 16 == PTRACE_EVENT_FORK
)
602 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
603 if (ret
== 0 && second_pid
!= 0)
607 linux_supports_tracefork_flag
= 1;
608 my_waitpid (second_pid
, &second_status
, 0);
609 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
611 warning (_("linux_test_for_tracefork: failed to kill second child"));
612 my_waitpid (second_pid
, &status
, 0);
616 warning (_("linux_test_for_tracefork: unexpected result from waitpid "
617 "(%d, status 0x%x)"), ret
, status
);
619 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
621 warning (_("linux_test_for_tracefork: failed to kill child"));
622 my_waitpid (child_pid
, &status
, 0);
624 linux_nat_async_events (async_events_original_state
);
627 /* Return non-zero iff we have tracefork functionality available.
628 This function also sets linux_supports_tracefork_flag. */
631 linux_supports_tracefork (int pid
)
633 if (linux_supports_tracefork_flag
== -1)
634 linux_test_for_tracefork (pid
);
635 return linux_supports_tracefork_flag
;
639 linux_supports_tracevforkdone (int pid
)
641 if (linux_supports_tracefork_flag
== -1)
642 linux_test_for_tracefork (pid
);
643 return linux_supports_tracevforkdone_flag
;
648 linux_enable_event_reporting (ptid_t ptid
)
650 int pid
= ptid_get_lwp (ptid
);
654 pid
= ptid_get_pid (ptid
);
656 if (! linux_supports_tracefork (pid
))
659 options
= PTRACE_O_TRACEFORK
| PTRACE_O_TRACEVFORK
| PTRACE_O_TRACEEXEC
660 | PTRACE_O_TRACECLONE
;
661 if (linux_supports_tracevforkdone (pid
))
662 options
|= PTRACE_O_TRACEVFORKDONE
;
664 /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support
665 read-only process state. */
667 ptrace (PTRACE_SETOPTIONS
, pid
, 0, options
);
671 linux_child_post_attach (int pid
)
673 linux_enable_event_reporting (pid_to_ptid (pid
));
674 check_for_thread_db ();
678 linux_child_post_startup_inferior (ptid_t ptid
)
680 linux_enable_event_reporting (ptid
);
681 check_for_thread_db ();
685 linux_child_follow_fork (struct target_ops
*ops
, int follow_child
)
688 struct target_waitstatus last_status
;
690 int parent_pid
, child_pid
;
692 if (target_can_async_p ())
693 target_async (NULL
, 0);
695 get_last_target_status (&last_ptid
, &last_status
);
696 has_vforked
= (last_status
.kind
== TARGET_WAITKIND_VFORKED
);
697 parent_pid
= ptid_get_lwp (last_ptid
);
699 parent_pid
= ptid_get_pid (last_ptid
);
700 child_pid
= PIDGET (last_status
.value
.related_pid
);
704 /* We're already attached to the parent, by default. */
706 /* Before detaching from the child, remove all breakpoints from
707 it. (This won't actually modify the breakpoint list, but will
708 physically remove the breakpoints from the child.) */
709 /* If we vforked this will remove the breakpoints from the parent
710 also, but they'll be reinserted below. */
711 detach_breakpoints (child_pid
);
713 /* Detach new forked process? */
716 if (info_verbose
|| debug_linux_nat
)
718 target_terminal_ours ();
719 fprintf_filtered (gdb_stdlog
,
720 "Detaching after fork from child process %d.\n",
724 ptrace (PTRACE_DETACH
, child_pid
, 0, 0);
728 struct fork_info
*fp
;
730 /* Add process to GDB's tables. */
731 add_inferior (child_pid
);
733 /* Retain child fork in ptrace (stopped) state. */
734 fp
= find_fork_pid (child_pid
);
736 fp
= add_fork (child_pid
);
737 fork_save_infrun_state (fp
, 0);
742 gdb_assert (linux_supports_tracefork_flag
>= 0);
743 if (linux_supports_tracevforkdone (0))
747 ptrace (PTRACE_CONT
, parent_pid
, 0, 0);
748 my_waitpid (parent_pid
, &status
, __WALL
);
749 if ((status
>> 16) != PTRACE_EVENT_VFORK_DONE
)
750 warning (_("Unexpected waitpid result %06x when waiting for "
751 "vfork-done"), status
);
755 /* We can't insert breakpoints until the child has
756 finished with the shared memory region. We need to
757 wait until that happens. Ideal would be to just
759 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
760 - waitpid (parent_pid, &status, __WALL);
761 However, most architectures can't handle a syscall
762 being traced on the way out if it wasn't traced on
765 We might also think to loop, continuing the child
766 until it exits or gets a SIGTRAP. One problem is
767 that the child might call ptrace with PTRACE_TRACEME.
769 There's no simple and reliable way to figure out when
770 the vforked child will be done with its copy of the
771 shared memory. We could step it out of the syscall,
772 two instructions, let it go, and then single-step the
773 parent once. When we have hardware single-step, this
774 would work; with software single-step it could still
775 be made to work but we'd have to be able to insert
776 single-step breakpoints in the child, and we'd have
777 to insert -just- the single-step breakpoint in the
778 parent. Very awkward.
780 In the end, the best we can do is to make sure it
781 runs for a little while. Hopefully it will be out of
782 range of any breakpoints we reinsert. Usually this
783 is only the single-step breakpoint at vfork's return
789 /* Since we vforked, breakpoints were removed in the parent
790 too. Put them back. */
791 reattach_breakpoints (parent_pid
);
796 struct thread_info
*last_tp
= find_thread_pid (last_ptid
);
797 struct thread_info
*tp
;
798 char child_pid_spelling
[40];
800 /* Copy user stepping state to the new inferior thread. */
801 struct breakpoint
*step_resume_breakpoint
= last_tp
->step_resume_breakpoint
;
802 CORE_ADDR step_range_start
= last_tp
->step_range_start
;
803 CORE_ADDR step_range_end
= last_tp
->step_range_end
;
804 struct frame_id step_frame_id
= last_tp
->step_frame_id
;
806 /* Otherwise, deleting the parent would get rid of this
808 last_tp
->step_resume_breakpoint
= NULL
;
810 /* Needed to keep the breakpoint lists in sync. */
812 detach_breakpoints (child_pid
);
814 /* Before detaching from the parent, remove all breakpoints from it. */
815 remove_breakpoints ();
817 if (info_verbose
|| debug_linux_nat
)
819 target_terminal_ours ();
820 fprintf_filtered (gdb_stdlog
,
821 "Attaching after fork to child process %d.\n",
825 /* If we're vforking, we may want to hold on to the parent until
826 the child exits or execs. At exec time we can remove the old
827 breakpoints from the parent and detach it; at exit time we
828 could do the same (or even, sneakily, resume debugging it - the
829 child's exec has failed, or something similar).
831 This doesn't clean up "properly", because we can't call
832 target_detach, but that's OK; if the current target is "child",
833 then it doesn't need any further cleanups, and lin_lwp will
834 generally not encounter vfork (vfork is defined to fork
837 The holding part is very easy if we have VFORKDONE events;
838 but keeping track of both processes is beyond GDB at the
839 moment. So we don't expose the parent to the rest of GDB.
840 Instead we quietly hold onto it until such time as we can
845 linux_parent_pid
= parent_pid
;
846 detach_inferior (parent_pid
);
848 else if (!detach_fork
)
850 struct fork_info
*fp
;
851 /* Retain parent fork in ptrace (stopped) state. */
852 fp
= find_fork_pid (parent_pid
);
854 fp
= add_fork (parent_pid
);
855 fork_save_infrun_state (fp
, 0);
858 target_detach (NULL
, 0);
860 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
861 add_inferior (child_pid
);
863 /* Reinstall ourselves, since we might have been removed in
864 target_detach (which does other necessary cleanup). */
867 linux_nat_switch_fork (inferior_ptid
);
868 check_for_thread_db ();
870 tp
= inferior_thread ();
871 tp
->step_resume_breakpoint
= step_resume_breakpoint
;
872 tp
->step_range_start
= step_range_start
;
873 tp
->step_range_end
= step_range_end
;
874 tp
->step_frame_id
= step_frame_id
;
876 /* Reset breakpoints in the child as appropriate. */
877 follow_inferior_reset_breakpoints ();
880 if (target_can_async_p ())
881 target_async (inferior_event_handler
, 0);
888 linux_child_insert_fork_catchpoint (int pid
)
890 if (! linux_supports_tracefork (pid
))
891 error (_("Your system does not support fork catchpoints."));
895 linux_child_insert_vfork_catchpoint (int pid
)
897 if (!linux_supports_tracefork (pid
))
898 error (_("Your system does not support vfork catchpoints."));
902 linux_child_insert_exec_catchpoint (int pid
)
904 if (!linux_supports_tracefork (pid
))
905 error (_("Your system does not support exec catchpoints."));
908 /* On GNU/Linux there are no real LWP's. The closest thing to LWP's
909 are processes sharing the same VM space. A multi-threaded process
910 is basically a group of such processes. However, such a grouping
911 is almost entirely a user-space issue; the kernel doesn't enforce
912 such a grouping at all (this might change in the future). In
913 general, we'll rely on the threads library (i.e. the GNU/Linux
914 Threads library) to provide such a grouping.
916 It is perfectly well possible to write a multi-threaded application
917 without the assistance of a threads library, by using the clone
918 system call directly. This module should be able to give some
919 rudimentary support for debugging such applications if developers
920 specify the CLONE_PTRACE flag in the clone system call, and are
921 using the Linux kernel 2.4 or above.
923 Note that there are some peculiarities in GNU/Linux that affect
926 - In general one should specify the __WCLONE flag to waitpid in
927 order to make it report events for any of the cloned processes
928 (and leave it out for the initial process). However, if a cloned
929 process has exited the exit status is only reported if the
930 __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
931 we cannot use it since GDB must work on older systems too.
933 - When a traced, cloned process exits and is waited for by the
934 debugger, the kernel reassigns it to the original parent and
935 keeps it around as a "zombie". Somehow, the GNU/Linux Threads
936 library doesn't notice this, which leads to the "zombie problem":
937 When debugged a multi-threaded process that spawns a lot of
938 threads will run out of processes, even if the threads exit,
939 because the "zombies" stay around. */
941 /* List of known LWPs. */
942 struct lwp_info
*lwp_list
;
944 /* Number of LWPs in the list. */
948 /* Original signal mask. */
949 static sigset_t normal_mask
;
951 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
952 _initialize_linux_nat. */
953 static sigset_t suspend_mask
;
955 /* SIGCHLD action for synchronous mode. */
956 struct sigaction sync_sigchld_action
;
958 /* SIGCHLD action for asynchronous mode. */
959 static struct sigaction async_sigchld_action
;
961 /* SIGCHLD default action, to pass to new inferiors. */
962 static struct sigaction sigchld_default_action
;
965 /* Prototypes for local functions. */
966 static int stop_wait_callback (struct lwp_info
*lp
, void *data
);
967 static int linux_nat_thread_alive (ptid_t ptid
);
968 static char *linux_child_pid_to_exec_file (int pid
);
969 static int cancel_breakpoint (struct lwp_info
*lp
);
972 /* Convert wait status STATUS to a string. Used for printing debug
976 status_to_str (int status
)
980 if (WIFSTOPPED (status
))
981 snprintf (buf
, sizeof (buf
), "%s (stopped)",
982 strsignal (WSTOPSIG (status
)));
983 else if (WIFSIGNALED (status
))
984 snprintf (buf
, sizeof (buf
), "%s (terminated)",
985 strsignal (WSTOPSIG (status
)));
987 snprintf (buf
, sizeof (buf
), "%d (exited)", WEXITSTATUS (status
));
992 /* Initialize the list of LWPs. Note that this module, contrary to
993 what GDB's generic threads layer does for its thread list,
994 re-initializes the LWP lists whenever we mourn or detach (which
995 doesn't involve mourning) the inferior. */
1000 struct lwp_info
*lp
, *lpnext
;
1002 for (lp
= lwp_list
; lp
; lp
= lpnext
)
1012 /* Add the LWP specified by PID to the list. Return a pointer to the
1013 structure describing the new LWP. The LWP should already be stopped
1014 (with an exception for the very first LWP). */
1016 static struct lwp_info
*
1017 add_lwp (ptid_t ptid
)
1019 struct lwp_info
*lp
;
1021 gdb_assert (is_lwp (ptid
));
1023 lp
= (struct lwp_info
*) xmalloc (sizeof (struct lwp_info
));
1025 memset (lp
, 0, sizeof (struct lwp_info
));
1027 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
1031 lp
->next
= lwp_list
;
1035 if (num_lwps
> 1 && linux_nat_new_thread
!= NULL
)
1036 linux_nat_new_thread (ptid
);
1041 /* Remove the LWP specified by PID from the list. */
1044 delete_lwp (ptid_t ptid
)
1046 struct lwp_info
*lp
, *lpprev
;
1050 for (lp
= lwp_list
; lp
; lpprev
= lp
, lp
= lp
->next
)
1051 if (ptid_equal (lp
->ptid
, ptid
))
1060 lpprev
->next
= lp
->next
;
1062 lwp_list
= lp
->next
;
1067 /* Return a pointer to the structure describing the LWP corresponding
1068 to PID. If no corresponding LWP could be found, return NULL. */
1070 static struct lwp_info
*
1071 find_lwp_pid (ptid_t ptid
)
1073 struct lwp_info
*lp
;
1077 lwp
= GET_LWP (ptid
);
1079 lwp
= GET_PID (ptid
);
1081 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
1082 if (lwp
== GET_LWP (lp
->ptid
))
1088 /* Call CALLBACK with its second argument set to DATA for every LWP in
1089 the list. If CALLBACK returns 1 for a particular LWP, return a
1090 pointer to the structure describing that LWP immediately.
1091 Otherwise return NULL. */
1094 iterate_over_lwps (int (*callback
) (struct lwp_info
*, void *), void *data
)
1096 struct lwp_info
*lp
, *lpnext
;
1098 for (lp
= lwp_list
; lp
; lp
= lpnext
)
1101 if ((*callback
) (lp
, data
))
1108 /* Update our internal state when changing from one fork (checkpoint,
1109 et cetera) to another indicated by NEW_PTID. We can only switch
1110 single-threaded applications, so we only create one new LWP, and
1111 the previous list is discarded. */
1114 linux_nat_switch_fork (ptid_t new_ptid
)
1116 struct lwp_info
*lp
;
1119 lp
= add_lwp (new_ptid
);
1122 init_thread_list ();
1123 add_thread_silent (new_ptid
);
1126 /* Handle the exit of a single thread LP. */
1129 exit_lwp (struct lwp_info
*lp
)
1131 struct thread_info
*th
= find_thread_pid (lp
->ptid
);
1135 if (print_thread_events
)
1136 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp
->ptid
));
1138 delete_thread (lp
->ptid
);
1141 delete_lwp (lp
->ptid
);
1144 /* Detect `T (stopped)' in `/proc/PID/status'.
1145 Other states including `T (tracing stop)' are reported as false. */
1148 pid_is_stopped (pid_t pid
)
1154 snprintf (buf
, sizeof (buf
), "/proc/%d/status", (int) pid
);
1155 status_file
= fopen (buf
, "r");
1156 if (status_file
!= NULL
)
1160 while (fgets (buf
, sizeof (buf
), status_file
))
1162 if (strncmp (buf
, "State:", 6) == 0)
1168 if (have_state
&& strstr (buf
, "T (stopped)") != NULL
)
1170 fclose (status_file
);
1175 /* Wait for the LWP specified by LP, which we have just attached to.
1176 Returns a wait status for that LWP, to cache. */
1179 linux_nat_post_attach_wait (ptid_t ptid
, int first
, int *cloned
,
1182 pid_t new_pid
, pid
= GET_LWP (ptid
);
1185 if (pid_is_stopped (pid
))
1187 if (debug_linux_nat
)
1188 fprintf_unfiltered (gdb_stdlog
,
1189 "LNPAW: Attaching to a stopped process\n");
1191 /* The process is definitely stopped. It is in a job control
1192 stop, unless the kernel predates the TASK_STOPPED /
1193 TASK_TRACED distinction, in which case it might be in a
1194 ptrace stop. Make sure it is in a ptrace stop; from there we
1195 can kill it, signal it, et cetera.
1197 First make sure there is a pending SIGSTOP. Since we are
1198 already attached, the process can not transition from stopped
1199 to running without a PTRACE_CONT; so we know this signal will
1200 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1201 probably already in the queue (unless this kernel is old
1202 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1203 is not an RT signal, it can only be queued once. */
1204 kill_lwp (pid
, SIGSTOP
);
1206 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1207 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1208 ptrace (PTRACE_CONT
, pid
, 0, 0);
1211 /* Make sure the initial process is stopped. The user-level threads
1212 layer might want to poke around in the inferior, and that won't
1213 work if things haven't stabilized yet. */
1214 new_pid
= my_waitpid (pid
, &status
, 0);
1215 if (new_pid
== -1 && errno
== ECHILD
)
1218 warning (_("%s is a cloned process"), target_pid_to_str (ptid
));
1220 /* Try again with __WCLONE to check cloned processes. */
1221 new_pid
= my_waitpid (pid
, &status
, __WCLONE
);
1225 gdb_assert (pid
== new_pid
&& WIFSTOPPED (status
));
1227 if (WSTOPSIG (status
) != SIGSTOP
)
1230 if (debug_linux_nat
)
1231 fprintf_unfiltered (gdb_stdlog
,
1232 "LNPAW: Received %s after attaching\n",
1233 status_to_str (status
));
1239 /* Attach to the LWP specified by PID. Return 0 if successful or -1
1240 if the new LWP could not be attached. */
1243 lin_lwp_attach_lwp (ptid_t ptid
)
1245 struct lwp_info
*lp
;
1246 enum sigchld_state async_events_original_state
;
1248 gdb_assert (is_lwp (ptid
));
1250 async_events_original_state
= linux_nat_async_events (sigchld_sync
);
1252 lp
= find_lwp_pid (ptid
);
1254 /* We assume that we're already attached to any LWP that has an id
1255 equal to the overall process id, and to any LWP that is already
1256 in our list of LWPs. If we're not seeing exit events from threads
1257 and we've had PID wraparound since we last tried to stop all threads,
1258 this assumption might be wrong; fortunately, this is very unlikely
1260 if (GET_LWP (ptid
) != GET_PID (ptid
) && lp
== NULL
)
1262 int status
, cloned
= 0, signalled
= 0;
1264 if (ptrace (PTRACE_ATTACH
, GET_LWP (ptid
), 0, 0) < 0)
1266 /* If we fail to attach to the thread, issue a warning,
1267 but continue. One way this can happen is if thread
1268 creation is interrupted; as of Linux kernel 2.6.19, a
1269 bug may place threads in the thread list and then fail
1271 warning (_("Can't attach %s: %s"), target_pid_to_str (ptid
),
1272 safe_strerror (errno
));
1276 if (debug_linux_nat
)
1277 fprintf_unfiltered (gdb_stdlog
,
1278 "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
1279 target_pid_to_str (ptid
));
1281 status
= linux_nat_post_attach_wait (ptid
, 0, &cloned
, &signalled
);
1282 lp
= add_lwp (ptid
);
1284 lp
->cloned
= cloned
;
1285 lp
->signalled
= signalled
;
1286 if (WSTOPSIG (status
) != SIGSTOP
)
1289 lp
->status
= status
;
1292 target_post_attach (GET_LWP (lp
->ptid
));
1294 if (debug_linux_nat
)
1296 fprintf_unfiltered (gdb_stdlog
,
1297 "LLAL: waitpid %s received %s\n",
1298 target_pid_to_str (ptid
),
1299 status_to_str (status
));
1304 /* We assume that the LWP representing the original process is
1305 already stopped. Mark it as stopped in the data structure
1306 that the GNU/linux ptrace layer uses to keep track of
1307 threads. Note that this won't have already been done since
1308 the main thread will have, we assume, been stopped by an
1309 attach from a different layer. */
1311 lp
= add_lwp (ptid
);
1315 linux_nat_async_events (async_events_original_state
);
1320 linux_nat_create_inferior (char *exec_file
, char *allargs
, char **env
,
1323 int saved_async
= 0;
1324 #ifdef HAVE_PERSONALITY
1325 int personality_orig
= 0, personality_set
= 0;
1326 #endif /* HAVE_PERSONALITY */
1328 /* The fork_child mechanism is synchronous and calls target_wait, so
1329 we have to mask the async mode. */
1331 if (target_can_async_p ())
1332 /* Mask async mode. Creating a child requires a loop calling
1333 wait_for_inferior currently. */
1334 saved_async
= linux_nat_async_mask (0);
1337 /* Restore the original signal mask. */
1338 sigprocmask (SIG_SETMASK
, &normal_mask
, NULL
);
1339 /* Make sure we don't block SIGCHLD during a sigsuspend. */
1340 suspend_mask
= normal_mask
;
1341 sigdelset (&suspend_mask
, SIGCHLD
);
1344 /* Set SIGCHLD to the default action, until after execing the child,
1345 since the inferior inherits the superior's signal mask. It will
1346 be blocked again in linux_nat_wait, which is only reached after
1347 the inferior execing. */
1348 linux_nat_async_events (sigchld_default
);
1350 #ifdef HAVE_PERSONALITY
1351 if (disable_randomization
)
1354 personality_orig
= personality (0xffffffff);
1355 if (errno
== 0 && !(personality_orig
& ADDR_NO_RANDOMIZE
))
1357 personality_set
= 1;
1358 personality (personality_orig
| ADDR_NO_RANDOMIZE
);
1360 if (errno
!= 0 || (personality_set
1361 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE
)))
1362 warning (_("Error disabling address space randomization: %s"),
1363 safe_strerror (errno
));
1365 #endif /* HAVE_PERSONALITY */
1367 linux_ops
->to_create_inferior (exec_file
, allargs
, env
, from_tty
);
1369 #ifdef HAVE_PERSONALITY
1370 if (personality_set
)
1373 personality (personality_orig
);
1375 warning (_("Error restoring address space randomization: %s"),
1376 safe_strerror (errno
));
1378 #endif /* HAVE_PERSONALITY */
1381 linux_nat_async_mask (saved_async
);
1385 linux_nat_attach (char *args
, int from_tty
)
1387 struct lwp_info
*lp
;
1391 /* FIXME: We should probably accept a list of process id's, and
1392 attach all of them. */
1393 linux_ops
->to_attach (args
, from_tty
);
1395 if (!target_can_async_p ())
1397 /* Restore the original signal mask. */
1398 sigprocmask (SIG_SETMASK
, &normal_mask
, NULL
);
1399 /* Make sure we don't block SIGCHLD during a sigsuspend. */
1400 suspend_mask
= normal_mask
;
1401 sigdelset (&suspend_mask
, SIGCHLD
);
1404 /* The ptrace base target adds the main thread with (pid,0,0)
1405 format. Decorate it with lwp info. */
1406 ptid
= BUILD_LWP (GET_PID (inferior_ptid
), GET_PID (inferior_ptid
));
1407 thread_change_ptid (inferior_ptid
, ptid
);
1409 /* Add the initial process as the first LWP to the list. */
1410 lp
= add_lwp (ptid
);
1412 status
= linux_nat_post_attach_wait (lp
->ptid
, 1, &lp
->cloned
,
1416 /* Save the wait status to report later. */
1418 if (debug_linux_nat
)
1419 fprintf_unfiltered (gdb_stdlog
,
1420 "LNA: waitpid %ld, saving status %s\n",
1421 (long) GET_PID (lp
->ptid
), status_to_str (status
));
1423 if (!target_can_async_p ())
1424 lp
->status
= status
;
1427 /* We already waited for this LWP, so put the wait result on the
1428 pipe. The event loop will wake up and gets us to handling
1430 linux_nat_event_pipe_push (GET_PID (lp
->ptid
), status
,
1431 lp
->cloned
? __WCLONE
: 0);
1432 /* Register in the event loop. */
1433 target_async (inferior_event_handler
, 0);
1437 /* Get pending status of LP. */
1439 get_pending_status (struct lwp_info
*lp
, int *status
)
1441 struct target_waitstatus last
;
1444 get_last_target_status (&last_ptid
, &last
);
1446 /* If this lwp is the ptid that GDB is processing an event from, the
1447 signal will be in stop_signal. Otherwise, in all-stop + sync
1448 mode, we may cache pending events in lp->status while trying to
1449 stop all threads (see stop_wait_callback). In async mode, the
1450 events are always cached in waitpid_queue. */
1456 enum target_signal signo
= TARGET_SIGNAL_0
;
1458 if (is_executing (lp
->ptid
))
1460 /* If the core thought this lwp was executing --- e.g., the
1461 executing property hasn't been updated yet, but the
1462 thread has been stopped with a stop_callback /
1463 stop_wait_callback sequence (see linux_nat_detach for
1464 example) --- we can only have pending events in the local
1466 if (queued_waitpid (GET_LWP (lp
->ptid
), status
, __WALL
) != -1)
1468 if (WIFSTOPPED (*status
))
1469 signo
= target_signal_from_host (WSTOPSIG (*status
));
1471 /* If not stopped, then the lwp is gone, no use in
1472 resending a signal. */
1477 /* If the core knows the thread is not executing, then we
1478 have the last signal recorded in
1479 thread_info->stop_signal. */
1481 struct thread_info
*tp
= find_thread_pid (lp
->ptid
);
1482 signo
= tp
->stop_signal
;
1485 if (signo
!= TARGET_SIGNAL_0
1486 && !signal_pass_state (signo
))
1488 if (debug_linux_nat
)
1489 fprintf_unfiltered (gdb_stdlog
, "\
1490 GPT: lwp %s had signal %s, but it is in no pass state\n",
1491 target_pid_to_str (lp
->ptid
),
1492 target_signal_to_string (signo
));
1496 if (signo
!= TARGET_SIGNAL_0
)
1497 *status
= W_STOPCODE (target_signal_to_host (signo
));
1499 if (debug_linux_nat
)
1500 fprintf_unfiltered (gdb_stdlog
,
1501 "GPT: lwp %s as pending signal %s\n",
1502 target_pid_to_str (lp
->ptid
),
1503 target_signal_to_string (signo
));
1508 if (GET_LWP (lp
->ptid
) == GET_LWP (last_ptid
))
1510 struct thread_info
*tp
= find_thread_pid (lp
->ptid
);
1511 if (tp
->stop_signal
!= TARGET_SIGNAL_0
1512 && signal_pass_state (tp
->stop_signal
))
1513 *status
= W_STOPCODE (target_signal_to_host (tp
->stop_signal
));
1515 else if (target_can_async_p ())
1516 queued_waitpid (GET_LWP (lp
->ptid
), status
, __WALL
);
1518 *status
= lp
->status
;
1525 detach_callback (struct lwp_info
*lp
, void *data
)
1527 gdb_assert (lp
->status
== 0 || WIFSTOPPED (lp
->status
));
1529 if (debug_linux_nat
&& lp
->status
)
1530 fprintf_unfiltered (gdb_stdlog
, "DC: Pending %s for %s on detach.\n",
1531 strsignal (WSTOPSIG (lp
->status
)),
1532 target_pid_to_str (lp
->ptid
));
1534 /* If there is a pending SIGSTOP, get rid of it. */
1537 if (debug_linux_nat
)
1538 fprintf_unfiltered (gdb_stdlog
,
1539 "DC: Sending SIGCONT to %s\n",
1540 target_pid_to_str (lp
->ptid
));
1542 kill_lwp (GET_LWP (lp
->ptid
), SIGCONT
);
1546 /* We don't actually detach from the LWP that has an id equal to the
1547 overall process id just yet. */
1548 if (GET_LWP (lp
->ptid
) != GET_PID (lp
->ptid
))
1552 /* Pass on any pending signal for this LWP. */
1553 get_pending_status (lp
, &status
);
1556 if (ptrace (PTRACE_DETACH
, GET_LWP (lp
->ptid
), 0,
1557 WSTOPSIG (status
)) < 0)
1558 error (_("Can't detach %s: %s"), target_pid_to_str (lp
->ptid
),
1559 safe_strerror (errno
));
1561 if (debug_linux_nat
)
1562 fprintf_unfiltered (gdb_stdlog
,
1563 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1564 target_pid_to_str (lp
->ptid
),
1565 strsignal (WSTOPSIG (lp
->status
)));
1567 delete_lwp (lp
->ptid
);
1574 linux_nat_detach (char *args
, int from_tty
)
1578 enum target_signal sig
;
1580 if (target_can_async_p ())
1581 linux_nat_async (NULL
, 0);
1583 /* Stop all threads before detaching. ptrace requires that the
1584 thread is stopped to sucessfully detach. */
1585 iterate_over_lwps (stop_callback
, NULL
);
1586 /* ... and wait until all of them have reported back that
1587 they're no longer running. */
1588 iterate_over_lwps (stop_wait_callback
, NULL
);
1590 iterate_over_lwps (detach_callback
, NULL
);
1592 /* Only the initial process should be left right now. */
1593 gdb_assert (num_lwps
== 1);
1595 /* Pass on any pending signal for the last LWP. */
1596 if ((args
== NULL
|| *args
== '\0')
1597 && get_pending_status (lwp_list
, &status
) != -1
1598 && WIFSTOPPED (status
))
1600 /* Put the signal number in ARGS so that inf_ptrace_detach will
1601 pass it along with PTRACE_DETACH. */
1603 sprintf (args
, "%d", (int) WSTOPSIG (status
));
1604 fprintf_unfiltered (gdb_stdlog
,
1605 "LND: Sending signal %s to %s\n",
1607 target_pid_to_str (lwp_list
->ptid
));
1610 /* Destroy LWP info; it's no longer valid. */
1613 pid
= GET_PID (inferior_ptid
);
1614 inferior_ptid
= pid_to_ptid (pid
);
1615 linux_ops
->to_detach (args
, from_tty
);
1617 if (target_can_async_p ())
1618 drain_queued_events (pid
);
1624 resume_callback (struct lwp_info
*lp
, void *data
)
1626 if (lp
->stopped
&& lp
->status
== 0)
1628 linux_ops
->to_resume (pid_to_ptid (GET_LWP (lp
->ptid
)),
1629 0, TARGET_SIGNAL_0
);
1630 if (debug_linux_nat
)
1631 fprintf_unfiltered (gdb_stdlog
,
1632 "RC: PTRACE_CONT %s, 0, 0 (resume sibling)\n",
1633 target_pid_to_str (lp
->ptid
));
1636 memset (&lp
->siginfo
, 0, sizeof (lp
->siginfo
));
1638 else if (lp
->stopped
&& debug_linux_nat
)
1639 fprintf_unfiltered (gdb_stdlog
, "RC: Not resuming sibling %s (has pending)\n",
1640 target_pid_to_str (lp
->ptid
));
1641 else if (debug_linux_nat
)
1642 fprintf_unfiltered (gdb_stdlog
, "RC: Not resuming sibling %s (not stopped)\n",
1643 target_pid_to_str (lp
->ptid
));
1649 resume_clear_callback (struct lwp_info
*lp
, void *data
)
1656 resume_set_callback (struct lwp_info
*lp
, void *data
)
1663 linux_nat_resume (ptid_t ptid
, int step
, enum target_signal signo
)
1665 struct lwp_info
*lp
;
1668 if (debug_linux_nat
)
1669 fprintf_unfiltered (gdb_stdlog
,
1670 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1671 step
? "step" : "resume",
1672 target_pid_to_str (ptid
),
1673 signo
? strsignal (signo
) : "0",
1674 target_pid_to_str (inferior_ptid
));
1676 if (target_can_async_p ())
1677 /* Block events while we're here. */
1678 linux_nat_async_events (sigchld_sync
);
1680 /* A specific PTID means `step only this process id'. */
1681 resume_all
= (PIDGET (ptid
) == -1);
1683 if (non_stop
&& resume_all
)
1684 internal_error (__FILE__
, __LINE__
,
1685 "can't resume all in non-stop mode");
1690 iterate_over_lwps (resume_set_callback
, NULL
);
1692 iterate_over_lwps (resume_clear_callback
, NULL
);
1695 /* If PID is -1, it's the current inferior that should be
1696 handled specially. */
1697 if (PIDGET (ptid
) == -1)
1698 ptid
= inferior_ptid
;
1700 lp
= find_lwp_pid (ptid
);
1701 gdb_assert (lp
!= NULL
);
1703 /* Convert to something the lower layer understands. */
1704 ptid
= pid_to_ptid (GET_LWP (lp
->ptid
));
1706 /* Remember if we're stepping. */
1709 /* Mark this LWP as resumed. */
1712 /* If we have a pending wait status for this thread, there is no
1713 point in resuming the process. But first make sure that
1714 linux_nat_wait won't preemptively handle the event - we
1715 should never take this short-circuit if we are going to
1716 leave LP running, since we have skipped resuming all the
1717 other threads. This bit of code needs to be synchronized
1718 with linux_nat_wait. */
1720 /* In async mode, we never have pending wait status. */
1721 if (target_can_async_p () && lp
->status
)
1722 internal_error (__FILE__
, __LINE__
, "Pending status in async mode");
1724 if (lp
->status
&& WIFSTOPPED (lp
->status
))
1727 struct inferior
*inf
;
1729 inf
= find_inferior_pid (ptid_get_pid (ptid
));
1731 saved_signo
= target_signal_from_host (WSTOPSIG (lp
->status
));
1733 /* Defer to common code if we're gaining control of the
1735 if (inf
->stop_soon
== NO_STOP_QUIETLY
1736 && signal_stop_state (saved_signo
) == 0
1737 && signal_print_state (saved_signo
) == 0
1738 && signal_pass_state (saved_signo
) == 1)
1740 if (debug_linux_nat
)
1741 fprintf_unfiltered (gdb_stdlog
,
1742 "LLR: Not short circuiting for ignored "
1743 "status 0x%x\n", lp
->status
);
1745 /* FIXME: What should we do if we are supposed to continue
1746 this thread with a signal? */
1747 gdb_assert (signo
== TARGET_SIGNAL_0
);
1748 signo
= saved_signo
;
1755 /* FIXME: What should we do if we are supposed to continue
1756 this thread with a signal? */
1757 gdb_assert (signo
== TARGET_SIGNAL_0
);
1759 if (debug_linux_nat
)
1760 fprintf_unfiltered (gdb_stdlog
,
1761 "LLR: Short circuiting for status 0x%x\n",
1767 /* Mark LWP as not stopped to prevent it from being continued by
1772 iterate_over_lwps (resume_callback
, NULL
);
1774 linux_ops
->to_resume (ptid
, step
, signo
);
1775 memset (&lp
->siginfo
, 0, sizeof (lp
->siginfo
));
1777 if (debug_linux_nat
)
1778 fprintf_unfiltered (gdb_stdlog
,
1779 "LLR: %s %s, %s (resume event thread)\n",
1780 step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1781 target_pid_to_str (ptid
),
1782 signo
? strsignal (signo
) : "0");
1784 if (target_can_async_p ())
1785 target_async (inferior_event_handler
, 0);
1788 /* Issue kill to specified lwp. */
1790 static int tkill_failed
;
1793 kill_lwp (int lwpid
, int signo
)
1797 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1798 fails, then we are not using nptl threads and we should be using kill. */
1800 #ifdef HAVE_TKILL_SYSCALL
1803 int ret
= syscall (__NR_tkill
, lwpid
, signo
);
1804 if (errno
!= ENOSYS
)
1811 return kill (lwpid
, signo
);
1814 /* Handle a GNU/Linux extended wait response. If we see a clone
1815 event, we need to add the new LWP to our list (and not report the
1816 trap to higher layers). This function returns non-zero if the
1817 event should be ignored and we should wait again. If STOPPING is
1818 true, the new LWP remains stopped, otherwise it is continued. */
1821 linux_handle_extended_wait (struct lwp_info
*lp
, int status
,
1824 int pid
= GET_LWP (lp
->ptid
);
1825 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1826 struct lwp_info
*new_lp
= NULL
;
1827 int event
= status
>> 16;
1829 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
1830 || event
== PTRACE_EVENT_CLONE
)
1832 unsigned long new_pid
;
1835 ptrace (PTRACE_GETEVENTMSG
, pid
, 0, &new_pid
);
1837 /* If we haven't already seen the new PID stop, wait for it now. */
1838 if (! pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
1840 /* The new child has a pending SIGSTOP. We can't affect it until it
1841 hits the SIGSTOP, but we're already attached. */
1842 ret
= my_waitpid (new_pid
, &status
,
1843 (event
== PTRACE_EVENT_CLONE
) ? __WCLONE
: 0);
1845 perror_with_name (_("waiting for new child"));
1846 else if (ret
!= new_pid
)
1847 internal_error (__FILE__
, __LINE__
,
1848 _("wait returned unexpected PID %d"), ret
);
1849 else if (!WIFSTOPPED (status
))
1850 internal_error (__FILE__
, __LINE__
,
1851 _("wait returned unexpected status 0x%x"), status
);
1854 ourstatus
->value
.related_pid
= ptid_build (new_pid
, new_pid
, 0);
1856 if (event
== PTRACE_EVENT_FORK
)
1857 ourstatus
->kind
= TARGET_WAITKIND_FORKED
;
1858 else if (event
== PTRACE_EVENT_VFORK
)
1859 ourstatus
->kind
= TARGET_WAITKIND_VFORKED
;
1862 struct cleanup
*old_chain
;
1864 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
1865 new_lp
= add_lwp (BUILD_LWP (new_pid
, GET_PID (inferior_ptid
)));
1867 new_lp
->stopped
= 1;
1869 if (WSTOPSIG (status
) != SIGSTOP
)
1871 /* This can happen if someone starts sending signals to
1872 the new thread before it gets a chance to run, which
1873 have a lower number than SIGSTOP (e.g. SIGUSR1).
1874 This is an unlikely case, and harder to handle for
1875 fork / vfork than for clone, so we do not try - but
1876 we handle it for clone events here. We'll send
1877 the other signal on to the thread below. */
1879 new_lp
->signalled
= 1;
1886 /* Add the new thread to GDB's lists as soon as possible
1889 1) the frontend doesn't have to wait for a stop to
1892 2) we tag it with the correct running state. */
1894 /* If the thread_db layer is active, let it know about
1895 this new thread, and add it to GDB's list. */
1896 if (!thread_db_attach_lwp (new_lp
->ptid
))
1898 /* We're not using thread_db. Add it to GDB's
1900 target_post_attach (GET_LWP (new_lp
->ptid
));
1901 add_thread (new_lp
->ptid
);
1906 set_running (new_lp
->ptid
, 1);
1907 set_executing (new_lp
->ptid
, 1);
1913 new_lp
->stopped
= 0;
1914 new_lp
->resumed
= 1;
1915 ptrace (PTRACE_CONT
, new_pid
, 0,
1916 status
? WSTOPSIG (status
) : 0);
1919 if (debug_linux_nat
)
1920 fprintf_unfiltered (gdb_stdlog
,
1921 "LHEW: Got clone event from LWP %ld, resuming\n",
1922 GET_LWP (lp
->ptid
));
1923 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
1931 if (event
== PTRACE_EVENT_EXEC
)
1933 ourstatus
->kind
= TARGET_WAITKIND_EXECD
;
1934 ourstatus
->value
.execd_pathname
1935 = xstrdup (linux_child_pid_to_exec_file (pid
));
1937 if (linux_parent_pid
)
1939 detach_breakpoints (linux_parent_pid
);
1940 ptrace (PTRACE_DETACH
, linux_parent_pid
, 0, 0);
1942 linux_parent_pid
= 0;
1945 /* At this point, all inserted breakpoints are gone. Doing this
1946 as soon as we detect an exec prevents the badness of deleting
1947 a breakpoint writing the current "shadow contents" to lift
1948 the bp. That shadow is NOT valid after an exec.
1950 Note that we have to do this after the detach_breakpoints
1951 call above, otherwise breakpoints wouldn't be lifted from the
1952 parent on a vfork, because detach_breakpoints would think
1953 that breakpoints are not inserted. */
1954 mark_breakpoints_out ();
1958 internal_error (__FILE__
, __LINE__
,
1959 _("unknown ptrace event %d"), event
);
1962 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
1966 wait_lwp (struct lwp_info
*lp
)
1970 int thread_dead
= 0;
1972 gdb_assert (!lp
->stopped
);
1973 gdb_assert (lp
->status
== 0);
1975 pid
= my_waitpid (GET_LWP (lp
->ptid
), &status
, 0);
1976 if (pid
== -1 && errno
== ECHILD
)
1978 pid
= my_waitpid (GET_LWP (lp
->ptid
), &status
, __WCLONE
);
1979 if (pid
== -1 && errno
== ECHILD
)
1981 /* The thread has previously exited. We need to delete it
1982 now because, for some vendor 2.4 kernels with NPTL
1983 support backported, there won't be an exit event unless
1984 it is the main thread. 2.6 kernels will report an exit
1985 event for each thread that exits, as expected. */
1987 if (debug_linux_nat
)
1988 fprintf_unfiltered (gdb_stdlog
, "WL: %s vanished.\n",
1989 target_pid_to_str (lp
->ptid
));
1995 gdb_assert (pid
== GET_LWP (lp
->ptid
));
1997 if (debug_linux_nat
)
1999 fprintf_unfiltered (gdb_stdlog
,
2000 "WL: waitpid %s received %s\n",
2001 target_pid_to_str (lp
->ptid
),
2002 status_to_str (status
));
2006 /* Check if the thread has exited. */
2007 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2010 if (debug_linux_nat
)
2011 fprintf_unfiltered (gdb_stdlog
, "WL: %s exited.\n",
2012 target_pid_to_str (lp
->ptid
));
2021 gdb_assert (WIFSTOPPED (status
));
2023 /* Handle GNU/Linux's extended waitstatus for trace events. */
2024 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 != 0)
2026 if (debug_linux_nat
)
2027 fprintf_unfiltered (gdb_stdlog
,
2028 "WL: Handling extended status 0x%06x\n",
2030 if (linux_handle_extended_wait (lp
, status
, 1))
2031 return wait_lwp (lp
);
2037 /* Save the most recent siginfo for LP. This is currently only called
2038 for SIGTRAP; some ports use the si_addr field for
2039 target_stopped_data_address. In the future, it may also be used to
2040 restore the siginfo of requeued signals. */
2043 save_siginfo (struct lwp_info
*lp
)
2046 ptrace (PTRACE_GETSIGINFO
, GET_LWP (lp
->ptid
),
2047 (PTRACE_TYPE_ARG3
) 0, &lp
->siginfo
);
2050 memset (&lp
->siginfo
, 0, sizeof (lp
->siginfo
));
2053 /* Send a SIGSTOP to LP. */
2056 stop_callback (struct lwp_info
*lp
, void *data
)
2058 if (!lp
->stopped
&& !lp
->signalled
)
2062 if (debug_linux_nat
)
2064 fprintf_unfiltered (gdb_stdlog
,
2065 "SC: kill %s **<SIGSTOP>**\n",
2066 target_pid_to_str (lp
->ptid
));
2069 ret
= kill_lwp (GET_LWP (lp
->ptid
), SIGSTOP
);
2070 if (debug_linux_nat
)
2072 fprintf_unfiltered (gdb_stdlog
,
2073 "SC: lwp kill %d %s\n",
2075 errno
? safe_strerror (errno
) : "ERRNO-OK");
2079 gdb_assert (lp
->status
== 0);
2085 /* Return non-zero if LWP PID has a pending SIGINT. */
2088 linux_nat_has_pending_sigint (int pid
)
2090 sigset_t pending
, blocked
, ignored
;
2093 linux_proc_pending_signals (pid
, &pending
, &blocked
, &ignored
);
2095 if (sigismember (&pending
, SIGINT
)
2096 && !sigismember (&ignored
, SIGINT
))
2102 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2105 set_ignore_sigint (struct lwp_info
*lp
, void *data
)
2107 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2108 flag to consume the next one. */
2109 if (lp
->stopped
&& lp
->status
!= 0 && WIFSTOPPED (lp
->status
)
2110 && WSTOPSIG (lp
->status
) == SIGINT
)
2113 lp
->ignore_sigint
= 1;
2118 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2119 This function is called after we know the LWP has stopped; if the LWP
2120 stopped before the expected SIGINT was delivered, then it will never have
2121 arrived. Also, if the signal was delivered to a shared queue and consumed
2122 by a different thread, it will never be delivered to this LWP. */
2125 maybe_clear_ignore_sigint (struct lwp_info
*lp
)
2127 if (!lp
->ignore_sigint
)
2130 if (!linux_nat_has_pending_sigint (GET_LWP (lp
->ptid
)))
2132 if (debug_linux_nat
)
2133 fprintf_unfiltered (gdb_stdlog
,
2134 "MCIS: Clearing bogus flag for %s\n",
2135 target_pid_to_str (lp
->ptid
));
2136 lp
->ignore_sigint
= 0;
2140 /* Wait until LP is stopped. */
2143 stop_wait_callback (struct lwp_info
*lp
, void *data
)
2149 status
= wait_lwp (lp
);
2153 if (lp
->ignore_sigint
&& WIFSTOPPED (status
)
2154 && WSTOPSIG (status
) == SIGINT
)
2156 lp
->ignore_sigint
= 0;
2159 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2160 if (debug_linux_nat
)
2161 fprintf_unfiltered (gdb_stdlog
,
2162 "PTRACE_CONT %s, 0, 0 (%s) (discarding SIGINT)\n",
2163 target_pid_to_str (lp
->ptid
),
2164 errno
? safe_strerror (errno
) : "OK");
2166 return stop_wait_callback (lp
, NULL
);
2169 maybe_clear_ignore_sigint (lp
);
2171 if (WSTOPSIG (status
) != SIGSTOP
)
2173 if (WSTOPSIG (status
) == SIGTRAP
)
2175 /* If a LWP other than the LWP that we're reporting an
2176 event for has hit a GDB breakpoint (as opposed to
2177 some random trap signal), then just arrange for it to
2178 hit it again later. We don't keep the SIGTRAP status
2179 and don't forward the SIGTRAP signal to the LWP. We
2180 will handle the current event, eventually we will
2181 resume all LWPs, and this one will get its breakpoint
2184 If we do not do this, then we run the risk that the
2185 user will delete or disable the breakpoint, but the
2186 thread will have already tripped on it. */
2188 /* Save the trap's siginfo in case we need it later. */
2191 /* Now resume this LWP and get the SIGSTOP event. */
2193 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2194 if (debug_linux_nat
)
2196 fprintf_unfiltered (gdb_stdlog
,
2197 "PTRACE_CONT %s, 0, 0 (%s)\n",
2198 target_pid_to_str (lp
->ptid
),
2199 errno
? safe_strerror (errno
) : "OK");
2201 fprintf_unfiltered (gdb_stdlog
,
2202 "SWC: Candidate SIGTRAP event in %s\n",
2203 target_pid_to_str (lp
->ptid
));
2205 /* Hold this event/waitstatus while we check to see if
2206 there are any more (we still want to get that SIGSTOP). */
2207 stop_wait_callback (lp
, NULL
);
2209 if (target_can_async_p ())
2211 /* Don't leave a pending wait status in async mode.
2212 Retrigger the breakpoint. */
2213 if (!cancel_breakpoint (lp
))
2215 /* There was no gdb breakpoint set at pc. Put
2216 the event back in the queue. */
2217 if (debug_linux_nat
)
2218 fprintf_unfiltered (gdb_stdlog
, "\
2219 SWC: leaving SIGTRAP in local queue of %s\n", target_pid_to_str (lp
->ptid
));
2220 push_waitpid (GET_LWP (lp
->ptid
),
2221 W_STOPCODE (SIGTRAP
),
2222 lp
->cloned
? __WCLONE
: 0);
2227 /* Hold the SIGTRAP for handling by
2229 /* If there's another event, throw it back into the
2233 if (debug_linux_nat
)
2234 fprintf_unfiltered (gdb_stdlog
,
2235 "SWC: kill %s, %s\n",
2236 target_pid_to_str (lp
->ptid
),
2237 status_to_str ((int) status
));
2238 kill_lwp (GET_LWP (lp
->ptid
), WSTOPSIG (lp
->status
));
2240 /* Save the sigtrap event. */
2241 lp
->status
= status
;
2247 /* The thread was stopped with a signal other than
2248 SIGSTOP, and didn't accidentally trip a breakpoint. */
2250 if (debug_linux_nat
)
2252 fprintf_unfiltered (gdb_stdlog
,
2253 "SWC: Pending event %s in %s\n",
2254 status_to_str ((int) status
),
2255 target_pid_to_str (lp
->ptid
));
2257 /* Now resume this LWP and get the SIGSTOP event. */
2259 ptrace (PTRACE_CONT
, GET_LWP (lp
->ptid
), 0, 0);
2260 if (debug_linux_nat
)
2261 fprintf_unfiltered (gdb_stdlog
,
2262 "SWC: PTRACE_CONT %s, 0, 0 (%s)\n",
2263 target_pid_to_str (lp
->ptid
),
2264 errno
? safe_strerror (errno
) : "OK");
2266 /* Hold this event/waitstatus while we check to see if
2267 there are any more (we still want to get that SIGSTOP). */
2268 stop_wait_callback (lp
, NULL
);
2270 /* If the lp->status field is still empty, use it to
2271 hold this event. If not, then this event must be
2272 returned to the event queue of the LWP. */
2273 if (lp
->status
|| target_can_async_p ())
2275 if (debug_linux_nat
)
2277 fprintf_unfiltered (gdb_stdlog
,
2278 "SWC: kill %s, %s\n",
2279 target_pid_to_str (lp
->ptid
),
2280 status_to_str ((int) status
));
2282 kill_lwp (GET_LWP (lp
->ptid
), WSTOPSIG (status
));
2285 lp
->status
= status
;
2291 /* We caught the SIGSTOP that we intended to catch, so
2292 there's no SIGSTOP pending. */
2301 /* Return non-zero if LP has a wait status pending. */
2304 status_callback (struct lwp_info
*lp
, void *data
)
2306 /* Only report a pending wait status if we pretend that this has
2307 indeed been resumed. */
2308 return (lp
->status
!= 0 && lp
->resumed
);
2311 /* Return non-zero if LP isn't stopped. */
2314 running_callback (struct lwp_info
*lp
, void *data
)
2316 return (lp
->stopped
== 0 || (lp
->status
!= 0 && lp
->resumed
));
2319 /* Count the LWP's that have had events. */
2322 count_events_callback (struct lwp_info
*lp
, void *data
)
2326 gdb_assert (count
!= NULL
);
2328 /* Count only resumed LWPs that have a SIGTRAP event pending. */
2329 if (lp
->status
!= 0 && lp
->resumed
2330 && WIFSTOPPED (lp
->status
) && WSTOPSIG (lp
->status
) == SIGTRAP
)
2336 /* Select the LWP (if any) that is currently being single-stepped. */
2339 select_singlestep_lwp_callback (struct lwp_info
*lp
, void *data
)
2341 if (lp
->step
&& lp
->status
!= 0)
2347 /* Select the Nth LWP that has had a SIGTRAP event. */
2350 select_event_lwp_callback (struct lwp_info
*lp
, void *data
)
2352 int *selector
= data
;
2354 gdb_assert (selector
!= NULL
);
2356 /* Select only resumed LWPs that have a SIGTRAP event pending. */
2357 if (lp
->status
!= 0 && lp
->resumed
2358 && WIFSTOPPED (lp
->status
) && WSTOPSIG (lp
->status
) == SIGTRAP
)
2359 if ((*selector
)-- == 0)
2366 cancel_breakpoint (struct lwp_info
*lp
)
2368 /* Arrange for a breakpoint to be hit again later. We don't keep
2369 the SIGTRAP status and don't forward the SIGTRAP signal to the
2370 LWP. We will handle the current event, eventually we will resume
2371 this LWP, and this breakpoint will trap again.
2373 If we do not do this, then we run the risk that the user will
2374 delete or disable the breakpoint, but the LWP will have already
2377 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
2378 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
2381 pc
= regcache_read_pc (regcache
) - gdbarch_decr_pc_after_break (gdbarch
);
2382 if (breakpoint_inserted_here_p (pc
))
2384 if (debug_linux_nat
)
2385 fprintf_unfiltered (gdb_stdlog
,
2386 "CB: Push back breakpoint for %s\n",
2387 target_pid_to_str (lp
->ptid
));
2389 /* Back up the PC if necessary. */
2390 if (gdbarch_decr_pc_after_break (gdbarch
))
2391 regcache_write_pc (regcache
, pc
);
2399 cancel_breakpoints_callback (struct lwp_info
*lp
, void *data
)
2401 struct lwp_info
*event_lp
= data
;
2403 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
2407 /* If a LWP other than the LWP that we're reporting an event for has
2408 hit a GDB breakpoint (as opposed to some random trap signal),
2409 then just arrange for it to hit it again later. We don't keep
2410 the SIGTRAP status and don't forward the SIGTRAP signal to the
2411 LWP. We will handle the current event, eventually we will resume
2412 all LWPs, and this one will get its breakpoint trap again.
2414 If we do not do this, then we run the risk that the user will
2415 delete or disable the breakpoint, but the LWP will have already
2419 && WIFSTOPPED (lp
->status
) && WSTOPSIG (lp
->status
) == SIGTRAP
2420 && cancel_breakpoint (lp
))
2421 /* Throw away the SIGTRAP. */
2427 /* Select one LWP out of those that have events pending. */
2430 select_event_lwp (struct lwp_info
**orig_lp
, int *status
)
2433 int random_selector
;
2434 struct lwp_info
*event_lp
;
2436 /* Record the wait status for the original LWP. */
2437 (*orig_lp
)->status
= *status
;
2439 /* Give preference to any LWP that is being single-stepped. */
2440 event_lp
= iterate_over_lwps (select_singlestep_lwp_callback
, NULL
);
2441 if (event_lp
!= NULL
)
2443 if (debug_linux_nat
)
2444 fprintf_unfiltered (gdb_stdlog
,
2445 "SEL: Select single-step %s\n",
2446 target_pid_to_str (event_lp
->ptid
));
2450 /* No single-stepping LWP. Select one at random, out of those
2451 which have had SIGTRAP events. */
2453 /* First see how many SIGTRAP events we have. */
2454 iterate_over_lwps (count_events_callback
, &num_events
);
2456 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
2457 random_selector
= (int)
2458 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
2460 if (debug_linux_nat
&& num_events
> 1)
2461 fprintf_unfiltered (gdb_stdlog
,
2462 "SEL: Found %d SIGTRAP events, selecting #%d\n",
2463 num_events
, random_selector
);
2465 event_lp
= iterate_over_lwps (select_event_lwp_callback
,
2469 if (event_lp
!= NULL
)
2471 /* Switch the event LWP. */
2472 *orig_lp
= event_lp
;
2473 *status
= event_lp
->status
;
2476 /* Flush the wait status for the event LWP. */
2477 (*orig_lp
)->status
= 0;
2480 /* Return non-zero if LP has been resumed. */
2483 resumed_callback (struct lwp_info
*lp
, void *data
)
2488 /* Stop an active thread, verify it still exists, then resume it. */
2491 stop_and_resume_callback (struct lwp_info
*lp
, void *data
)
2493 struct lwp_info
*ptr
;
2495 if (!lp
->stopped
&& !lp
->signalled
)
2497 stop_callback (lp
, NULL
);
2498 stop_wait_callback (lp
, NULL
);
2499 /* Resume if the lwp still exists. */
2500 for (ptr
= lwp_list
; ptr
; ptr
= ptr
->next
)
2503 resume_callback (lp
, NULL
);
2504 resume_set_callback (lp
, NULL
);
2510 /* Check if we should go on and pass this event to common code.
2511 Return the affected lwp if we are, or NULL otherwise. */
2512 static struct lwp_info
*
2513 linux_nat_filter_event (int lwpid
, int status
, int options
)
2515 struct lwp_info
*lp
;
2517 lp
= find_lwp_pid (pid_to_ptid (lwpid
));
2519 /* Check for stop events reported by a process we didn't already
2520 know about - anything not already in our LWP list.
2522 If we're expecting to receive stopped processes after
2523 fork, vfork, and clone events, then we'll just add the
2524 new one to our list and go back to waiting for the event
2525 to be reported - the stopped process might be returned
2526 from waitpid before or after the event is. */
2527 if (WIFSTOPPED (status
) && !lp
)
2529 linux_record_stopped_pid (lwpid
, status
);
2533 /* Make sure we don't report an event for the exit of an LWP not in
2534 our list, i.e. not part of the current process. This can happen
2535 if we detach from a program we original forked and then it
2537 if (!WIFSTOPPED (status
) && !lp
)
2540 /* NOTE drow/2003-06-17: This code seems to be meant for debugging
2541 CLONE_PTRACE processes which do not use the thread library -
2542 otherwise we wouldn't find the new LWP this way. That doesn't
2543 currently work, and the following code is currently unreachable
2544 due to the two blocks above. If it's fixed some day, this code
2545 should be broken out into a function so that we can also pick up
2546 LWPs from the new interface. */
2549 lp
= add_lwp (BUILD_LWP (lwpid
, GET_PID (inferior_ptid
)));
2550 if (options
& __WCLONE
)
2553 gdb_assert (WIFSTOPPED (status
)
2554 && WSTOPSIG (status
) == SIGSTOP
);
2557 if (!in_thread_list (inferior_ptid
))
2559 inferior_ptid
= BUILD_LWP (GET_PID (inferior_ptid
),
2560 GET_PID (inferior_ptid
));
2561 add_thread (inferior_ptid
);
2564 add_thread (lp
->ptid
);
2567 /* Save the trap's siginfo in case we need it later. */
2568 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
)
2571 /* Handle GNU/Linux's extended waitstatus for trace events. */
2572 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 != 0)
2574 if (debug_linux_nat
)
2575 fprintf_unfiltered (gdb_stdlog
,
2576 "LLW: Handling extended status 0x%06x\n",
2578 if (linux_handle_extended_wait (lp
, status
, 0))
2582 /* Check if the thread has exited. */
2583 if ((WIFEXITED (status
) || WIFSIGNALED (status
)) && num_lwps
> 1)
2585 /* If this is the main thread, we must stop all threads and
2586 verify if they are still alive. This is because in the nptl
2587 thread model, there is no signal issued for exiting LWPs
2588 other than the main thread. We only get the main thread exit
2589 signal once all child threads have already exited. If we
2590 stop all the threads and use the stop_wait_callback to check
2591 if they have exited we can determine whether this signal
2592 should be ignored or whether it means the end of the debugged
2593 application, regardless of which threading model is being
2595 if (GET_PID (lp
->ptid
) == GET_LWP (lp
->ptid
))
2598 iterate_over_lwps (stop_and_resume_callback
, NULL
);
2601 if (debug_linux_nat
)
2602 fprintf_unfiltered (gdb_stdlog
,
2603 "LLW: %s exited.\n",
2604 target_pid_to_str (lp
->ptid
));
2608 /* If there is at least one more LWP, then the exit signal was
2609 not the end of the debugged application and should be
2615 /* Check if the current LWP has previously exited. In the nptl
2616 thread model, LWPs other than the main thread do not issue
2617 signals when they exit so we must check whenever the thread has
2618 stopped. A similar check is made in stop_wait_callback(). */
2619 if (num_lwps
> 1 && !linux_nat_thread_alive (lp
->ptid
))
2621 if (debug_linux_nat
)
2622 fprintf_unfiltered (gdb_stdlog
,
2623 "LLW: %s exited.\n",
2624 target_pid_to_str (lp
->ptid
));
2628 /* Make sure there is at least one thread running. */
2629 gdb_assert (iterate_over_lwps (running_callback
, NULL
));
2631 /* Discard the event. */
2635 /* Make sure we don't report a SIGSTOP that we sent ourselves in
2636 an attempt to stop an LWP. */
2638 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGSTOP
)
2640 if (debug_linux_nat
)
2641 fprintf_unfiltered (gdb_stdlog
,
2642 "LLW: Delayed SIGSTOP caught for %s.\n",
2643 target_pid_to_str (lp
->ptid
));
2645 /* This is a delayed SIGSTOP. */
2648 registers_changed ();
2650 linux_ops
->to_resume (pid_to_ptid (GET_LWP (lp
->ptid
)),
2651 lp
->step
, TARGET_SIGNAL_0
);
2652 if (debug_linux_nat
)
2653 fprintf_unfiltered (gdb_stdlog
,
2654 "LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
2656 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2657 target_pid_to_str (lp
->ptid
));
2660 gdb_assert (lp
->resumed
);
2662 /* Discard the event. */
2666 /* Make sure we don't report a SIGINT that we have already displayed
2667 for another thread. */
2668 if (lp
->ignore_sigint
2669 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGINT
)
2671 if (debug_linux_nat
)
2672 fprintf_unfiltered (gdb_stdlog
,
2673 "LLW: Delayed SIGINT caught for %s.\n",
2674 target_pid_to_str (lp
->ptid
));
2676 /* This is a delayed SIGINT. */
2677 lp
->ignore_sigint
= 0;
2679 registers_changed ();
2680 linux_ops
->to_resume (pid_to_ptid (GET_LWP (lp
->ptid
)),
2681 lp
->step
, TARGET_SIGNAL_0
);
2682 if (debug_linux_nat
)
2683 fprintf_unfiltered (gdb_stdlog
,
2684 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
2686 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2687 target_pid_to_str (lp
->ptid
));
2690 gdb_assert (lp
->resumed
);
2692 /* Discard the event. */
2696 /* An interesting event. */
2701 /* Get the events stored in the pipe into the local queue, so they are
2702 accessible to queued_waitpid. We need to do this, since it is not
2703 always the case that the event at the head of the pipe is the event
2707 pipe_to_local_event_queue (void)
2709 if (debug_linux_nat_async
)
2710 fprintf_unfiltered (gdb_stdlog
,
2711 "PTLEQ: linux_nat_num_queued_events(%d)\n",
2712 linux_nat_num_queued_events
);
2713 while (linux_nat_num_queued_events
)
2715 int lwpid
, status
, options
;
2716 lwpid
= linux_nat_event_pipe_pop (&status
, &options
);
2717 gdb_assert (lwpid
> 0);
2718 push_waitpid (lwpid
, status
, options
);
2722 /* Get the unprocessed events stored in the local queue back into the
2723 pipe, so the event loop realizes there's something else to
2727 local_event_queue_to_pipe (void)
2729 struct waitpid_result
*w
= waitpid_queue
;
2732 struct waitpid_result
*next
= w
->next
;
2733 linux_nat_event_pipe_push (w
->pid
,
2739 waitpid_queue
= NULL
;
2741 if (debug_linux_nat_async
)
2742 fprintf_unfiltered (gdb_stdlog
,
2743 "LEQTP: linux_nat_num_queued_events(%d)\n",
2744 linux_nat_num_queued_events
);
2748 linux_nat_wait (ptid_t ptid
, struct target_waitstatus
*ourstatus
)
2750 struct lwp_info
*lp
= NULL
;
2753 pid_t pid
= PIDGET (ptid
);
2755 if (debug_linux_nat_async
)
2756 fprintf_unfiltered (gdb_stdlog
, "LLW: enter\n");
2758 /* The first time we get here after starting a new inferior, we may
2759 not have added it to the LWP list yet - this is the earliest
2760 moment at which we know its PID. */
2763 gdb_assert (!is_lwp (inferior_ptid
));
2765 /* Upgrade the main thread's ptid. */
2766 thread_change_ptid (inferior_ptid
,
2767 BUILD_LWP (GET_PID (inferior_ptid
),
2768 GET_PID (inferior_ptid
)));
2770 lp
= add_lwp (inferior_ptid
);
2774 /* Block events while we're here. */
2775 linux_nat_async_events (sigchld_sync
);
2779 /* Make sure there is at least one LWP that has been resumed. */
2780 gdb_assert (iterate_over_lwps (resumed_callback
, NULL
));
2782 /* First check if there is a LWP with a wait status pending. */
2785 /* Any LWP that's been resumed will do. */
2786 lp
= iterate_over_lwps (status_callback
, NULL
);
2789 if (target_can_async_p ())
2790 internal_error (__FILE__
, __LINE__
,
2791 "Found an LWP with a pending status in async mode.");
2793 status
= lp
->status
;
2796 if (debug_linux_nat
&& status
)
2797 fprintf_unfiltered (gdb_stdlog
,
2798 "LLW: Using pending wait status %s for %s.\n",
2799 status_to_str (status
),
2800 target_pid_to_str (lp
->ptid
));
2803 /* But if we don't find one, we'll have to wait, and check both
2804 cloned and uncloned processes. We start with the cloned
2806 options
= __WCLONE
| WNOHANG
;
2808 else if (is_lwp (ptid
))
2810 if (debug_linux_nat
)
2811 fprintf_unfiltered (gdb_stdlog
,
2812 "LLW: Waiting for specific LWP %s.\n",
2813 target_pid_to_str (ptid
));
2815 /* We have a specific LWP to check. */
2816 lp
= find_lwp_pid (ptid
);
2818 status
= lp
->status
;
2821 if (debug_linux_nat
&& status
)
2822 fprintf_unfiltered (gdb_stdlog
,
2823 "LLW: Using pending wait status %s for %s.\n",
2824 status_to_str (status
),
2825 target_pid_to_str (lp
->ptid
));
2827 /* If we have to wait, take into account whether PID is a cloned
2828 process or not. And we have to convert it to something that
2829 the layer beneath us can understand. */
2830 options
= lp
->cloned
? __WCLONE
: 0;
2831 pid
= GET_LWP (ptid
);
2834 if (status
&& lp
->signalled
)
2836 /* A pending SIGSTOP may interfere with the normal stream of
2837 events. In a typical case where interference is a problem,
2838 we have a SIGSTOP signal pending for LWP A while
2839 single-stepping it, encounter an event in LWP B, and take the
2840 pending SIGSTOP while trying to stop LWP A. After processing
2841 the event in LWP B, LWP A is continued, and we'll never see
2842 the SIGTRAP associated with the last time we were
2843 single-stepping LWP A. */
2845 /* Resume the thread. It should halt immediately returning the
2847 registers_changed ();
2848 linux_ops
->to_resume (pid_to_ptid (GET_LWP (lp
->ptid
)),
2849 lp
->step
, TARGET_SIGNAL_0
);
2850 if (debug_linux_nat
)
2851 fprintf_unfiltered (gdb_stdlog
,
2852 "LLW: %s %s, 0, 0 (expect SIGSTOP)\n",
2853 lp
->step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2854 target_pid_to_str (lp
->ptid
));
2856 gdb_assert (lp
->resumed
);
2858 /* This should catch the pending SIGSTOP. */
2859 stop_wait_callback (lp
, NULL
);
2862 if (!target_can_async_p ())
2864 /* Causes SIGINT to be passed on to the attached process. */
2873 if (target_can_async_p ())
2874 /* In async mode, don't ever block. Only look at the locally
2876 lwpid
= queued_waitpid (pid
, &status
, options
);
2878 lwpid
= my_waitpid (pid
, &status
, options
);
2882 gdb_assert (pid
== -1 || lwpid
== pid
);
2884 if (debug_linux_nat
)
2886 fprintf_unfiltered (gdb_stdlog
,
2887 "LLW: waitpid %ld received %s\n",
2888 (long) lwpid
, status_to_str (status
));
2891 lp
= linux_nat_filter_event (lwpid
, status
, options
);
2894 /* A discarded event. */
2904 /* Alternate between checking cloned and uncloned processes. */
2905 options
^= __WCLONE
;
2907 /* And every time we have checked both:
2908 In async mode, return to event loop;
2909 In sync mode, suspend waiting for a SIGCHLD signal. */
2910 if (options
& __WCLONE
)
2912 if (target_can_async_p ())
2914 /* No interesting event. */
2915 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2917 /* Get ready for the next event. */
2918 target_async (inferior_event_handler
, 0);
2920 if (debug_linux_nat_async
)
2921 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (ignore)\n");
2923 return minus_one_ptid
;
2926 sigsuspend (&suspend_mask
);
2930 /* We shouldn't end up here unless we want to try again. */
2931 gdb_assert (status
== 0);
2934 if (!target_can_async_p ())
2936 clear_sigio_trap ();
2937 clear_sigint_trap ();
2942 /* Don't report signals that GDB isn't interested in, such as
2943 signals that are neither printed nor stopped upon. Stopping all
2944 threads can be a bit time-consuming so if we want decent
2945 performance with heavily multi-threaded programs, especially when
2946 they're using a high frequency timer, we'd better avoid it if we
2949 if (WIFSTOPPED (status
))
2951 int signo
= target_signal_from_host (WSTOPSIG (status
));
2952 struct inferior
*inf
;
2954 inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
2957 /* Defer to common code if we get a signal while
2958 single-stepping, since that may need special care, e.g. to
2959 skip the signal handler, or, if we're gaining control of the
2962 && inf
->stop_soon
== NO_STOP_QUIETLY
2963 && signal_stop_state (signo
) == 0
2964 && signal_print_state (signo
) == 0
2965 && signal_pass_state (signo
) == 1)
2967 /* FIMXE: kettenis/2001-06-06: Should we resume all threads
2968 here? It is not clear we should. GDB may not expect
2969 other threads to run. On the other hand, not resuming
2970 newly attached threads may cause an unwanted delay in
2971 getting them running. */
2972 registers_changed ();
2973 linux_ops
->to_resume (pid_to_ptid (GET_LWP (lp
->ptid
)),
2975 if (debug_linux_nat
)
2976 fprintf_unfiltered (gdb_stdlog
,
2977 "LLW: %s %s, %s (preempt 'handle')\n",
2979 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2980 target_pid_to_str (lp
->ptid
),
2981 signo
? strsignal (signo
) : "0");
2989 /* Only do the below in all-stop, as we currently use SIGINT
2990 to implement target_stop (see linux_nat_stop) in
2992 if (signo
== TARGET_SIGNAL_INT
&& signal_pass_state (signo
) == 0)
2994 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
2995 forwarded to the entire process group, that is, all LWPs
2996 will receive it - unless they're using CLONE_THREAD to
2997 share signals. Since we only want to report it once, we
2998 mark it as ignored for all LWPs except this one. */
2999 iterate_over_lwps (set_ignore_sigint
, NULL
);
3000 lp
->ignore_sigint
= 0;
3003 maybe_clear_ignore_sigint (lp
);
3007 /* This LWP is stopped now. */
3010 if (debug_linux_nat
)
3011 fprintf_unfiltered (gdb_stdlog
, "LLW: Candidate event %s in %s.\n",
3012 status_to_str (status
), target_pid_to_str (lp
->ptid
));
3016 /* Now stop all other LWP's ... */
3017 iterate_over_lwps (stop_callback
, NULL
);
3019 /* ... and wait until all of them have reported back that
3020 they're no longer running. */
3021 iterate_over_lwps (stop_wait_callback
, NULL
);
3023 /* If we're not waiting for a specific LWP, choose an event LWP
3024 from among those that have had events. Giving equal priority
3025 to all LWPs that have had events helps prevent
3028 select_event_lwp (&lp
, &status
);
3031 /* Now that we've selected our final event LWP, cancel any
3032 breakpoints in other LWPs that have hit a GDB breakpoint. See
3033 the comment in cancel_breakpoints_callback to find out why. */
3034 iterate_over_lwps (cancel_breakpoints_callback
, lp
);
3036 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
)
3038 if (debug_linux_nat
)
3039 fprintf_unfiltered (gdb_stdlog
,
3040 "LLW: trap ptid is %s.\n",
3041 target_pid_to_str (lp
->ptid
));
3044 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3046 *ourstatus
= lp
->waitstatus
;
3047 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3050 store_waitstatus (ourstatus
, status
);
3052 /* Get ready for the next event. */
3053 if (target_can_async_p ())
3054 target_async (inferior_event_handler
, 0);
3056 if (debug_linux_nat_async
)
3057 fprintf_unfiltered (gdb_stdlog
, "LLW: exit\n");
3063 kill_callback (struct lwp_info
*lp
, void *data
)
3066 ptrace (PTRACE_KILL
, GET_LWP (lp
->ptid
), 0, 0);
3067 if (debug_linux_nat
)
3068 fprintf_unfiltered (gdb_stdlog
,
3069 "KC: PTRACE_KILL %s, 0, 0 (%s)\n",
3070 target_pid_to_str (lp
->ptid
),
3071 errno
? safe_strerror (errno
) : "OK");
3077 kill_wait_callback (struct lwp_info
*lp
, void *data
)
3081 /* We must make sure that there are no pending events (delayed
3082 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3083 program doesn't interfere with any following debugging session. */
3085 /* For cloned processes we must check both with __WCLONE and
3086 without, since the exit status of a cloned process isn't reported
3092 pid
= my_waitpid (GET_LWP (lp
->ptid
), NULL
, __WCLONE
);
3093 if (pid
!= (pid_t
) -1)
3095 if (debug_linux_nat
)
3096 fprintf_unfiltered (gdb_stdlog
,
3097 "KWC: wait %s received unknown.\n",
3098 target_pid_to_str (lp
->ptid
));
3099 /* The Linux kernel sometimes fails to kill a thread
3100 completely after PTRACE_KILL; that goes from the stop
3101 point in do_fork out to the one in
3102 get_signal_to_deliever and waits again. So kill it
3104 kill_callback (lp
, NULL
);
3107 while (pid
== GET_LWP (lp
->ptid
));
3109 gdb_assert (pid
== -1 && errno
== ECHILD
);
3114 pid
= my_waitpid (GET_LWP (lp
->ptid
), NULL
, 0);
3115 if (pid
!= (pid_t
) -1)
3117 if (debug_linux_nat
)
3118 fprintf_unfiltered (gdb_stdlog
,
3119 "KWC: wait %s received unk.\n",
3120 target_pid_to_str (lp
->ptid
));
3121 /* See the call to kill_callback above. */
3122 kill_callback (lp
, NULL
);
3125 while (pid
== GET_LWP (lp
->ptid
));
3127 gdb_assert (pid
== -1 && errno
== ECHILD
);
3132 linux_nat_kill (void)
3134 struct target_waitstatus last
;
3138 if (target_can_async_p ())
3139 target_async (NULL
, 0);
3141 /* If we're stopped while forking and we haven't followed yet,
3142 kill the other task. We need to do this first because the
3143 parent will be sleeping if this is a vfork. */
3145 get_last_target_status (&last_ptid
, &last
);
3147 if (last
.kind
== TARGET_WAITKIND_FORKED
3148 || last
.kind
== TARGET_WAITKIND_VFORKED
)
3150 ptrace (PT_KILL
, PIDGET (last
.value
.related_pid
), 0, 0);
3154 if (forks_exist_p ())
3156 linux_fork_killall ();
3157 drain_queued_events (-1);
3161 /* Stop all threads before killing them, since ptrace requires
3162 that the thread is stopped to sucessfully PTRACE_KILL. */
3163 iterate_over_lwps (stop_callback
, NULL
);
3164 /* ... and wait until all of them have reported back that
3165 they're no longer running. */
3166 iterate_over_lwps (stop_wait_callback
, NULL
);
3168 /* Kill all LWP's ... */
3169 iterate_over_lwps (kill_callback
, NULL
);
3171 /* ... and wait until we've flushed all events. */
3172 iterate_over_lwps (kill_wait_callback
, NULL
);
3175 target_mourn_inferior ();
3179 linux_nat_mourn_inferior (void)
3181 /* Destroy LWP info; it's no longer valid. */
3184 if (! forks_exist_p ())
3186 /* Normal case, no other forks available. */
3187 if (target_can_async_p ())
3188 linux_nat_async (NULL
, 0);
3189 linux_ops
->to_mourn_inferior ();
3192 /* Multi-fork case. The current inferior_ptid has exited, but
3193 there are other viable forks to debug. Delete the exiting
3194 one and context-switch to the first available. */
3195 linux_fork_mourn_inferior ();
3199 linux_nat_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3200 const char *annex
, gdb_byte
*readbuf
,
3201 const gdb_byte
*writebuf
,
3202 ULONGEST offset
, LONGEST len
)
3204 struct cleanup
*old_chain
= save_inferior_ptid ();
3207 if (is_lwp (inferior_ptid
))
3208 inferior_ptid
= pid_to_ptid (GET_LWP (inferior_ptid
));
3210 xfer
= linux_ops
->to_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
3213 do_cleanups (old_chain
);
3218 linux_nat_thread_alive (ptid_t ptid
)
3222 gdb_assert (is_lwp (ptid
));
3224 /* Send signal 0 instead of anything ptrace, because ptracing a
3225 running thread errors out claiming that the thread doesn't
3227 err
= kill_lwp (GET_LWP (ptid
), 0);
3229 if (debug_linux_nat
)
3230 fprintf_unfiltered (gdb_stdlog
,
3231 "LLTA: KILL(SIG0) %s (%s)\n",
3232 target_pid_to_str (ptid
),
3233 err
? safe_strerror (err
) : "OK");
3242 linux_nat_pid_to_str (ptid_t ptid
)
3244 static char buf
[64];
3247 && ((lwp_list
&& lwp_list
->next
)
3248 || GET_PID (ptid
) != GET_LWP (ptid
)))
3250 snprintf (buf
, sizeof (buf
), "LWP %ld", GET_LWP (ptid
));
3254 return normal_pid_to_str (ptid
);
3258 sigchld_handler (int signo
)
3260 if (target_async_permitted
3261 && linux_nat_async_events_state
!= sigchld_sync
3262 && signo
== SIGCHLD
)
3263 /* It is *always* a bug to hit this. */
3264 internal_error (__FILE__
, __LINE__
,
3265 "sigchld_handler called when async events are enabled");
3267 /* Do nothing. The only reason for this handler is that it allows
3268 us to use sigsuspend in linux_nat_wait above to wait for the
3269 arrival of a SIGCHLD. */
3272 /* Accepts an integer PID; Returns a string representing a file that
3273 can be opened to get the symbols for the child process. */
3276 linux_child_pid_to_exec_file (int pid
)
3278 char *name1
, *name2
;
3280 name1
= xmalloc (MAXPATHLEN
);
3281 name2
= xmalloc (MAXPATHLEN
);
3282 make_cleanup (xfree
, name1
);
3283 make_cleanup (xfree
, name2
);
3284 memset (name2
, 0, MAXPATHLEN
);
3286 sprintf (name1
, "/proc/%d/exe", pid
);
3287 if (readlink (name1
, name2
, MAXPATHLEN
) > 0)
3293 /* Service function for corefiles and info proc. */
3296 read_mapping (FILE *mapfile
,
3301 char *device
, long long *inode
, char *filename
)
3303 int ret
= fscanf (mapfile
, "%llx-%llx %s %llx %s %llx",
3304 addr
, endaddr
, permissions
, offset
, device
, inode
);
3307 if (ret
> 0 && ret
!= EOF
)
3309 /* Eat everything up to EOL for the filename. This will prevent
3310 weird filenames (such as one with embedded whitespace) from
3311 confusing this code. It also makes this code more robust in
3312 respect to annotations the kernel may add after the filename.
3314 Note the filename is used for informational purposes
3316 ret
+= fscanf (mapfile
, "%[^\n]\n", filename
);
3319 return (ret
!= 0 && ret
!= EOF
);
3322 /* Fills the "to_find_memory_regions" target vector. Lists the memory
3323 regions in the inferior for a corefile. */
3326 linux_nat_find_memory_regions (int (*func
) (CORE_ADDR
,
3328 int, int, int, void *), void *obfd
)
3330 long long pid
= PIDGET (inferior_ptid
);
3331 char mapsfilename
[MAXPATHLEN
];
3333 long long addr
, endaddr
, size
, offset
, inode
;
3334 char permissions
[8], device
[8], filename
[MAXPATHLEN
];
3335 int read
, write
, exec
;
3338 /* Compose the filename for the /proc memory map, and open it. */
3339 sprintf (mapsfilename
, "/proc/%lld/maps", pid
);
3340 if ((mapsfile
= fopen (mapsfilename
, "r")) == NULL
)
3341 error (_("Could not open %s."), mapsfilename
);
3344 fprintf_filtered (gdb_stdout
,
3345 "Reading memory regions from %s\n", mapsfilename
);
3347 /* Now iterate until end-of-file. */
3348 while (read_mapping (mapsfile
, &addr
, &endaddr
, &permissions
[0],
3349 &offset
, &device
[0], &inode
, &filename
[0]))
3351 size
= endaddr
- addr
;
3353 /* Get the segment's permissions. */
3354 read
= (strchr (permissions
, 'r') != 0);
3355 write
= (strchr (permissions
, 'w') != 0);
3356 exec
= (strchr (permissions
, 'x') != 0);
3360 fprintf_filtered (gdb_stdout
,
3361 "Save segment, %lld bytes at 0x%s (%c%c%c)",
3362 size
, paddr_nz (addr
),
3364 write
? 'w' : ' ', exec
? 'x' : ' ');
3366 fprintf_filtered (gdb_stdout
, " for %s", filename
);
3367 fprintf_filtered (gdb_stdout
, "\n");
3370 /* Invoke the callback function to create the corefile
3372 func (addr
, size
, read
, write
, exec
, obfd
);
3379 find_signalled_thread (struct thread_info
*info
, void *data
)
3381 if (info
->stop_signal
!= TARGET_SIGNAL_0
3382 && ptid_get_pid (info
->ptid
) == ptid_get_pid (inferior_ptid
))
3388 static enum target_signal
3389 find_stop_signal (void)
3391 struct thread_info
*info
=
3392 iterate_over_threads (find_signalled_thread
, NULL
);
3395 return info
->stop_signal
;
3397 return TARGET_SIGNAL_0
;
3400 /* Records the thread's register state for the corefile note
3404 linux_nat_do_thread_registers (bfd
*obfd
, ptid_t ptid
,
3405 char *note_data
, int *note_size
,
3406 enum target_signal stop_signal
)
3408 gdb_gregset_t gregs
;
3409 gdb_fpregset_t fpregs
;
3410 unsigned long lwp
= ptid_get_lwp (ptid
);
3411 struct regcache
*regcache
= get_thread_regcache (ptid
);
3412 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3413 const struct regset
*regset
;
3415 struct cleanup
*old_chain
;
3416 struct core_regset_section
*sect_list
;
3419 old_chain
= save_inferior_ptid ();
3420 inferior_ptid
= ptid
;
3421 target_fetch_registers (regcache
, -1);
3422 do_cleanups (old_chain
);
3424 core_regset_p
= gdbarch_regset_from_core_section_p (gdbarch
);
3425 sect_list
= gdbarch_core_regset_sections (gdbarch
);
3428 && (regset
= gdbarch_regset_from_core_section (gdbarch
, ".reg",
3429 sizeof (gregs
))) != NULL
3430 && regset
->collect_regset
!= NULL
)
3431 regset
->collect_regset (regset
, regcache
, -1,
3432 &gregs
, sizeof (gregs
));
3434 fill_gregset (regcache
, &gregs
, -1);
3436 note_data
= (char *) elfcore_write_prstatus (obfd
,
3440 stop_signal
, &gregs
);
3442 /* The loop below uses the new struct core_regset_section, which stores
3443 the supported section names and sizes for the core file. Note that
3444 note PRSTATUS needs to be treated specially. But the other notes are
3445 structurally the same, so they can benefit from the new struct. */
3446 if (core_regset_p
&& sect_list
!= NULL
)
3447 while (sect_list
->sect_name
!= NULL
)
3449 /* .reg was already handled above. */
3450 if (strcmp (sect_list
->sect_name
, ".reg") == 0)
3455 regset
= gdbarch_regset_from_core_section (gdbarch
,
3456 sect_list
->sect_name
,
3458 gdb_assert (regset
&& regset
->collect_regset
);
3459 gdb_regset
= xmalloc (sect_list
->size
);
3460 regset
->collect_regset (regset
, regcache
, -1,
3461 gdb_regset
, sect_list
->size
);
3462 note_data
= (char *) elfcore_write_register_note (obfd
,
3465 sect_list
->sect_name
,
3472 /* For architectures that does not have the struct core_regset_section
3473 implemented, we use the old method. When all the architectures have
3474 the new support, the code below should be deleted. */
3478 && (regset
= gdbarch_regset_from_core_section (gdbarch
, ".reg2",
3479 sizeof (fpregs
))) != NULL
3480 && regset
->collect_regset
!= NULL
)
3481 regset
->collect_regset (regset
, regcache
, -1,
3482 &fpregs
, sizeof (fpregs
));
3484 fill_fpregset (regcache
, &fpregs
, -1);
3486 note_data
= (char *) elfcore_write_prfpreg (obfd
,
3489 &fpregs
, sizeof (fpregs
));
3495 struct linux_nat_corefile_thread_data
3501 enum target_signal stop_signal
;
3504 /* Called by gdbthread.c once per thread. Records the thread's
3505 register state for the corefile note section. */
3508 linux_nat_corefile_thread_callback (struct lwp_info
*ti
, void *data
)
3510 struct linux_nat_corefile_thread_data
*args
= data
;
3512 args
->note_data
= linux_nat_do_thread_registers (args
->obfd
,
3522 /* Fills the "to_make_corefile_note" target vector. Builds the note
3523 section for a corefile, and returns it in a malloc buffer. */
3526 linux_nat_make_corefile_notes (bfd
*obfd
, int *note_size
)
3528 struct linux_nat_corefile_thread_data thread_args
;
3529 struct cleanup
*old_chain
;
3530 /* The variable size must be >= sizeof (prpsinfo_t.pr_fname). */
3531 char fname
[16] = { '\0' };
3532 /* The variable size must be >= sizeof (prpsinfo_t.pr_psargs). */
3533 char psargs
[80] = { '\0' };
3534 char *note_data
= NULL
;
3535 ptid_t current_ptid
= inferior_ptid
;
3539 if (get_exec_file (0))
3541 strncpy (fname
, strrchr (get_exec_file (0), '/') + 1, sizeof (fname
));
3542 strncpy (psargs
, get_exec_file (0), sizeof (psargs
));
3543 if (get_inferior_args ())
3546 char *psargs_end
= psargs
+ sizeof (psargs
);
3548 /* linux_elfcore_write_prpsinfo () handles zero unterminated
3550 string_end
= memchr (psargs
, 0, sizeof (psargs
));
3551 if (string_end
!= NULL
)
3553 *string_end
++ = ' ';
3554 strncpy (string_end
, get_inferior_args (),
3555 psargs_end
- string_end
);
3558 note_data
= (char *) elfcore_write_prpsinfo (obfd
,
3560 note_size
, fname
, psargs
);
3563 /* Dump information for threads. */
3564 thread_args
.obfd
= obfd
;
3565 thread_args
.note_data
= note_data
;
3566 thread_args
.note_size
= note_size
;
3567 thread_args
.num_notes
= 0;
3568 thread_args
.stop_signal
= find_stop_signal ();
3569 iterate_over_lwps (linux_nat_corefile_thread_callback
, &thread_args
);
3570 gdb_assert (thread_args
.num_notes
!= 0);
3571 note_data
= thread_args
.note_data
;
3573 auxv_len
= target_read_alloc (¤t_target
, TARGET_OBJECT_AUXV
,
3577 note_data
= elfcore_write_note (obfd
, note_data
, note_size
,
3578 "CORE", NT_AUXV
, auxv
, auxv_len
);
3582 make_cleanup (xfree
, note_data
);
3586 /* Implement the "info proc" command. */
3589 linux_nat_info_proc_cmd (char *args
, int from_tty
)
3591 long long pid
= PIDGET (inferior_ptid
);
3594 char buffer
[MAXPATHLEN
];
3595 char fname1
[MAXPATHLEN
], fname2
[MAXPATHLEN
];
3608 /* Break up 'args' into an argv array. */
3609 argv
= gdb_buildargv (args
);
3610 make_cleanup_freeargv (argv
);
3612 while (argv
!= NULL
&& *argv
!= NULL
)
3614 if (isdigit (argv
[0][0]))
3616 pid
= strtoul (argv
[0], NULL
, 10);
3618 else if (strncmp (argv
[0], "mappings", strlen (argv
[0])) == 0)
3622 else if (strcmp (argv
[0], "status") == 0)
3626 else if (strcmp (argv
[0], "stat") == 0)
3630 else if (strcmp (argv
[0], "cmd") == 0)
3634 else if (strncmp (argv
[0], "exe", strlen (argv
[0])) == 0)
3638 else if (strcmp (argv
[0], "cwd") == 0)
3642 else if (strncmp (argv
[0], "all", strlen (argv
[0])) == 0)
3648 /* [...] (future options here) */
3653 error (_("No current process: you must name one."));
3655 sprintf (fname1
, "/proc/%lld", pid
);
3656 if (stat (fname1
, &dummy
) != 0)
3657 error (_("No /proc directory: '%s'"), fname1
);
3659 printf_filtered (_("process %lld\n"), pid
);
3660 if (cmdline_f
|| all
)
3662 sprintf (fname1
, "/proc/%lld/cmdline", pid
);
3663 if ((procfile
= fopen (fname1
, "r")) != NULL
)
3665 fgets (buffer
, sizeof (buffer
), procfile
);
3666 printf_filtered ("cmdline = '%s'\n", buffer
);
3670 warning (_("unable to open /proc file '%s'"), fname1
);
3674 sprintf (fname1
, "/proc/%lld/cwd", pid
);
3675 memset (fname2
, 0, sizeof (fname2
));
3676 if (readlink (fname1
, fname2
, sizeof (fname2
)) > 0)
3677 printf_filtered ("cwd = '%s'\n", fname2
);
3679 warning (_("unable to read link '%s'"), fname1
);
3683 sprintf (fname1
, "/proc/%lld/exe", pid
);
3684 memset (fname2
, 0, sizeof (fname2
));
3685 if (readlink (fname1
, fname2
, sizeof (fname2
)) > 0)
3686 printf_filtered ("exe = '%s'\n", fname2
);
3688 warning (_("unable to read link '%s'"), fname1
);
3690 if (mappings_f
|| all
)
3692 sprintf (fname1
, "/proc/%lld/maps", pid
);
3693 if ((procfile
= fopen (fname1
, "r")) != NULL
)
3695 long long addr
, endaddr
, size
, offset
, inode
;
3696 char permissions
[8], device
[8], filename
[MAXPATHLEN
];
3698 printf_filtered (_("Mapped address spaces:\n\n"));
3699 if (gdbarch_addr_bit (current_gdbarch
) == 32)
3701 printf_filtered ("\t%10s %10s %10s %10s %7s\n",
3704 " Size", " Offset", "objfile");
3708 printf_filtered (" %18s %18s %10s %10s %7s\n",
3711 " Size", " Offset", "objfile");
3714 while (read_mapping (procfile
, &addr
, &endaddr
, &permissions
[0],
3715 &offset
, &device
[0], &inode
, &filename
[0]))
3717 size
= endaddr
- addr
;
3719 /* FIXME: carlton/2003-08-27: Maybe the printf_filtered
3720 calls here (and possibly above) should be abstracted
3721 out into their own functions? Andrew suggests using
3722 a generic local_address_string instead to print out
3723 the addresses; that makes sense to me, too. */
3725 if (gdbarch_addr_bit (current_gdbarch
) == 32)
3727 printf_filtered ("\t%#10lx %#10lx %#10x %#10x %7s\n",
3728 (unsigned long) addr
, /* FIXME: pr_addr */
3729 (unsigned long) endaddr
,
3731 (unsigned int) offset
,
3732 filename
[0] ? filename
: "");
3736 printf_filtered (" %#18lx %#18lx %#10x %#10x %7s\n",
3737 (unsigned long) addr
, /* FIXME: pr_addr */
3738 (unsigned long) endaddr
,
3740 (unsigned int) offset
,
3741 filename
[0] ? filename
: "");
3748 warning (_("unable to open /proc file '%s'"), fname1
);
3750 if (status_f
|| all
)
3752 sprintf (fname1
, "/proc/%lld/status", pid
);
3753 if ((procfile
= fopen (fname1
, "r")) != NULL
)
3755 while (fgets (buffer
, sizeof (buffer
), procfile
) != NULL
)
3756 puts_filtered (buffer
);
3760 warning (_("unable to open /proc file '%s'"), fname1
);
3764 sprintf (fname1
, "/proc/%lld/stat", pid
);
3765 if ((procfile
= fopen (fname1
, "r")) != NULL
)
3771 if (fscanf (procfile
, "%d ", &itmp
) > 0)
3772 printf_filtered (_("Process: %d\n"), itmp
);
3773 if (fscanf (procfile
, "(%[^)]) ", &buffer
[0]) > 0)
3774 printf_filtered (_("Exec file: %s\n"), buffer
);
3775 if (fscanf (procfile
, "%c ", &ctmp
) > 0)
3776 printf_filtered (_("State: %c\n"), ctmp
);
3777 if (fscanf (procfile
, "%d ", &itmp
) > 0)
3778 printf_filtered (_("Parent process: %d\n"), itmp
);
3779 if (fscanf (procfile
, "%d ", &itmp
) > 0)
3780 printf_filtered (_("Process group: %d\n"), itmp
);
3781 if (fscanf (procfile
, "%d ", &itmp
) > 0)
3782 printf_filtered (_("Session id: %d\n"), itmp
);
3783 if (fscanf (procfile
, "%d ", &itmp
) > 0)
3784 printf_filtered (_("TTY: %d\n"), itmp
);
3785 if (fscanf (procfile
, "%d ", &itmp
) > 0)
3786 printf_filtered (_("TTY owner process group: %d\n"), itmp
);
3787 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3788 printf_filtered (_("Flags: 0x%lx\n"), ltmp
);
3789 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3790 printf_filtered (_("Minor faults (no memory page): %lu\n"),
3791 (unsigned long) ltmp
);
3792 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3793 printf_filtered (_("Minor faults, children: %lu\n"),
3794 (unsigned long) ltmp
);
3795 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3796 printf_filtered (_("Major faults (memory page faults): %lu\n"),
3797 (unsigned long) ltmp
);
3798 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3799 printf_filtered (_("Major faults, children: %lu\n"),
3800 (unsigned long) ltmp
);
3801 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3802 printf_filtered (_("utime: %ld\n"), ltmp
);
3803 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3804 printf_filtered (_("stime: %ld\n"), ltmp
);
3805 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3806 printf_filtered (_("utime, children: %ld\n"), ltmp
);
3807 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3808 printf_filtered (_("stime, children: %ld\n"), ltmp
);
3809 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3810 printf_filtered (_("jiffies remaining in current time slice: %ld\n"),
3812 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3813 printf_filtered (_("'nice' value: %ld\n"), ltmp
);
3814 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3815 printf_filtered (_("jiffies until next timeout: %lu\n"),
3816 (unsigned long) ltmp
);
3817 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3818 printf_filtered (_("jiffies until next SIGALRM: %lu\n"),
3819 (unsigned long) ltmp
);
3820 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3821 printf_filtered (_("start time (jiffies since system boot): %ld\n"),
3823 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3824 printf_filtered (_("Virtual memory size: %lu\n"),
3825 (unsigned long) ltmp
);
3826 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3827 printf_filtered (_("Resident set size: %lu\n"), (unsigned long) ltmp
);
3828 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3829 printf_filtered (_("rlim: %lu\n"), (unsigned long) ltmp
);
3830 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3831 printf_filtered (_("Start of text: 0x%lx\n"), ltmp
);
3832 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3833 printf_filtered (_("End of text: 0x%lx\n"), ltmp
);
3834 if (fscanf (procfile
, "%lu ", <mp
) > 0)
3835 printf_filtered (_("Start of stack: 0x%lx\n"), ltmp
);
3836 #if 0 /* Don't know how architecture-dependent the rest is...
3837 Anyway the signal bitmap info is available from "status". */
3838 if (fscanf (procfile
, "%lu ", <mp
) > 0) /* FIXME arch? */
3839 printf_filtered (_("Kernel stack pointer: 0x%lx\n"), ltmp
);
3840 if (fscanf (procfile
, "%lu ", <mp
) > 0) /* FIXME arch? */
3841 printf_filtered (_("Kernel instr pointer: 0x%lx\n"), ltmp
);
3842 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3843 printf_filtered (_("Pending signals bitmap: 0x%lx\n"), ltmp
);
3844 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3845 printf_filtered (_("Blocked signals bitmap: 0x%lx\n"), ltmp
);
3846 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3847 printf_filtered (_("Ignored signals bitmap: 0x%lx\n"), ltmp
);
3848 if (fscanf (procfile
, "%ld ", <mp
) > 0)
3849 printf_filtered (_("Catched signals bitmap: 0x%lx\n"), ltmp
);
3850 if (fscanf (procfile
, "%lu ", <mp
) > 0) /* FIXME arch? */
3851 printf_filtered (_("wchan (system call): 0x%lx\n"), ltmp
);
3856 warning (_("unable to open /proc file '%s'"), fname1
);
3860 /* Implement the to_xfer_partial interface for memory reads using the /proc
3861 filesystem. Because we can use a single read() call for /proc, this
3862 can be much more efficient than banging away at PTRACE_PEEKTEXT,
3863 but it doesn't support writes. */
3866 linux_proc_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3867 const char *annex
, gdb_byte
*readbuf
,
3868 const gdb_byte
*writebuf
,
3869 ULONGEST offset
, LONGEST len
)
3875 if (object
!= TARGET_OBJECT_MEMORY
|| !readbuf
)
3878 /* Don't bother for one word. */
3879 if (len
< 3 * sizeof (long))
3882 /* We could keep this file open and cache it - possibly one per
3883 thread. That requires some juggling, but is even faster. */
3884 sprintf (filename
, "/proc/%d/mem", PIDGET (inferior_ptid
));
3885 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
3889 /* If pread64 is available, use it. It's faster if the kernel
3890 supports it (only one syscall), and it's 64-bit safe even on
3891 32-bit platforms (for instance, SPARC debugging a SPARC64
3894 if (pread64 (fd
, readbuf
, len
, offset
) != len
)
3896 if (lseek (fd
, offset
, SEEK_SET
) == -1 || read (fd
, readbuf
, len
) != len
)
3906 /* Parse LINE as a signal set and add its set bits to SIGS. */
3909 add_line_to_sigset (const char *line
, sigset_t
*sigs
)
3911 int len
= strlen (line
) - 1;
3915 if (line
[len
] != '\n')
3916 error (_("Could not parse signal set: %s"), line
);
3924 if (*p
>= '0' && *p
<= '9')
3926 else if (*p
>= 'a' && *p
<= 'f')
3927 digit
= *p
- 'a' + 10;
3929 error (_("Could not parse signal set: %s"), line
);
3934 sigaddset (sigs
, signum
+ 1);
3936 sigaddset (sigs
, signum
+ 2);
3938 sigaddset (sigs
, signum
+ 3);
3940 sigaddset (sigs
, signum
+ 4);
3946 /* Find process PID's pending signals from /proc/pid/status and set
3950 linux_proc_pending_signals (int pid
, sigset_t
*pending
, sigset_t
*blocked
, sigset_t
*ignored
)
3953 char buffer
[MAXPATHLEN
], fname
[MAXPATHLEN
];
3956 sigemptyset (pending
);
3957 sigemptyset (blocked
);
3958 sigemptyset (ignored
);
3959 sprintf (fname
, "/proc/%d/status", pid
);
3960 procfile
= fopen (fname
, "r");
3961 if (procfile
== NULL
)
3962 error (_("Could not open %s"), fname
);
3964 while (fgets (buffer
, MAXPATHLEN
, procfile
) != NULL
)
3966 /* Normal queued signals are on the SigPnd line in the status
3967 file. However, 2.6 kernels also have a "shared" pending
3968 queue for delivering signals to a thread group, so check for
3971 Unfortunately some Red Hat kernels include the shared pending
3972 queue but not the ShdPnd status field. */
3974 if (strncmp (buffer
, "SigPnd:\t", 8) == 0)
3975 add_line_to_sigset (buffer
+ 8, pending
);
3976 else if (strncmp (buffer
, "ShdPnd:\t", 8) == 0)
3977 add_line_to_sigset (buffer
+ 8, pending
);
3978 else if (strncmp (buffer
, "SigBlk:\t", 8) == 0)
3979 add_line_to_sigset (buffer
+ 8, blocked
);
3980 else if (strncmp (buffer
, "SigIgn:\t", 8) == 0)
3981 add_line_to_sigset (buffer
+ 8, ignored
);
3988 linux_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3989 const char *annex
, gdb_byte
*readbuf
,
3990 const gdb_byte
*writebuf
, ULONGEST offset
, LONGEST len
)
3994 if (object
== TARGET_OBJECT_AUXV
)
3995 return procfs_xfer_auxv (ops
, object
, annex
, readbuf
, writebuf
,
3998 xfer
= linux_proc_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4003 return super_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4007 /* Create a prototype generic GNU/Linux target. The client can override
4008 it with local methods. */
4011 linux_target_install_ops (struct target_ops
*t
)
4013 t
->to_insert_fork_catchpoint
= linux_child_insert_fork_catchpoint
;
4014 t
->to_insert_vfork_catchpoint
= linux_child_insert_vfork_catchpoint
;
4015 t
->to_insert_exec_catchpoint
= linux_child_insert_exec_catchpoint
;
4016 t
->to_pid_to_exec_file
= linux_child_pid_to_exec_file
;
4017 t
->to_post_startup_inferior
= linux_child_post_startup_inferior
;
4018 t
->to_post_attach
= linux_child_post_attach
;
4019 t
->to_follow_fork
= linux_child_follow_fork
;
4020 t
->to_find_memory_regions
= linux_nat_find_memory_regions
;
4021 t
->to_make_corefile_notes
= linux_nat_make_corefile_notes
;
4023 super_xfer_partial
= t
->to_xfer_partial
;
4024 t
->to_xfer_partial
= linux_xfer_partial
;
4030 struct target_ops
*t
;
4032 t
= inf_ptrace_target ();
4033 linux_target_install_ops (t
);
4039 linux_trad_target (CORE_ADDR (*register_u_offset
)(struct gdbarch
*, int, int))
4041 struct target_ops
*t
;
4043 t
= inf_ptrace_trad_target (register_u_offset
);
4044 linux_target_install_ops (t
);
4049 /* target_is_async_p implementation. */
4052 linux_nat_is_async_p (void)
4054 /* NOTE: palves 2008-03-21: We're only async when the user requests
4055 it explicitly with the "maintenance set target-async" command.
4056 Someday, linux will always be async. */
4057 if (!target_async_permitted
)
4063 /* target_can_async_p implementation. */
4066 linux_nat_can_async_p (void)
4068 /* NOTE: palves 2008-03-21: We're only async when the user requests
4069 it explicitly with the "maintenance set target-async" command.
4070 Someday, linux will always be async. */
4071 if (!target_async_permitted
)
4074 /* See target.h/target_async_mask. */
4075 return linux_nat_async_mask_value
;
4079 linux_nat_supports_non_stop (void)
4084 /* target_async_mask implementation. */
4087 linux_nat_async_mask (int mask
)
4090 current_state
= linux_nat_async_mask_value
;
4092 if (current_state
!= mask
)
4096 linux_nat_async (NULL
, 0);
4097 linux_nat_async_mask_value
= mask
;
4101 linux_nat_async_mask_value
= mask
;
4102 linux_nat_async (inferior_event_handler
, 0);
4106 return current_state
;
4109 /* Pop an event from the event pipe. */
4112 linux_nat_event_pipe_pop (int* ptr_status
, int* ptr_options
)
4114 struct waitpid_result event
= {0};
4119 ret
= read (linux_nat_event_pipe
[0], &event
, sizeof (event
));
4121 while (ret
== -1 && errno
== EINTR
);
4123 gdb_assert (ret
== sizeof (event
));
4125 *ptr_status
= event
.status
;
4126 *ptr_options
= event
.options
;
4128 linux_nat_num_queued_events
--;
4133 /* Push an event into the event pipe. */
4136 linux_nat_event_pipe_push (int pid
, int status
, int options
)
4139 struct waitpid_result event
= {0};
4141 event
.status
= status
;
4142 event
.options
= options
;
4146 ret
= write (linux_nat_event_pipe
[1], &event
, sizeof (event
));
4147 gdb_assert ((ret
== -1 && errno
== EINTR
) || ret
== sizeof (event
));
4148 } while (ret
== -1 && errno
== EINTR
);
4150 linux_nat_num_queued_events
++;
4154 get_pending_events (void)
4156 int status
, options
, pid
;
4158 if (!target_async_permitted
4159 || linux_nat_async_events_state
!= sigchld_async
)
4160 internal_error (__FILE__
, __LINE__
,
4161 "get_pending_events called with async masked");
4166 options
= __WCLONE
| WNOHANG
;
4170 pid
= waitpid (-1, &status
, options
);
4172 while (pid
== -1 && errno
== EINTR
);
4179 pid
= waitpid (-1, &status
, options
);
4181 while (pid
== -1 && errno
== EINTR
);
4185 /* No more children reporting events. */
4188 if (debug_linux_nat_async
)
4189 fprintf_unfiltered (gdb_stdlog
, "\
4190 get_pending_events: pid(%d), status(%x), options (%x)\n",
4191 pid
, status
, options
);
4193 linux_nat_event_pipe_push (pid
, status
, options
);
4196 if (debug_linux_nat_async
)
4197 fprintf_unfiltered (gdb_stdlog
, "\
4198 get_pending_events: linux_nat_num_queued_events(%d)\n",
4199 linux_nat_num_queued_events
);
4202 /* SIGCHLD handler for async mode. */
4205 async_sigchld_handler (int signo
)
4207 if (debug_linux_nat_async
)
4208 fprintf_unfiltered (gdb_stdlog
, "async_sigchld_handler\n");
4210 get_pending_events ();
4213 /* Set SIGCHLD handling state to STATE. Returns previous state. */
4215 static enum sigchld_state
4216 linux_nat_async_events (enum sigchld_state state
)
4218 enum sigchld_state current_state
= linux_nat_async_events_state
;
4220 if (debug_linux_nat_async
)
4221 fprintf_unfiltered (gdb_stdlog
,
4222 "LNAE: state(%d): linux_nat_async_events_state(%d), "
4223 "linux_nat_num_queued_events(%d)\n",
4224 state
, linux_nat_async_events_state
,
4225 linux_nat_num_queued_events
);
4227 if (current_state
!= state
)
4230 sigemptyset (&mask
);
4231 sigaddset (&mask
, SIGCHLD
);
4233 /* Always block before changing state. */
4234 sigprocmask (SIG_BLOCK
, &mask
, NULL
);
4236 /* Set new state. */
4237 linux_nat_async_events_state
= state
;
4243 /* Block target events. */
4244 sigprocmask (SIG_BLOCK
, &mask
, NULL
);
4245 sigaction (SIGCHLD
, &sync_sigchld_action
, NULL
);
4246 /* Get events out of queue, and make them available to
4247 queued_waitpid / my_waitpid. */
4248 pipe_to_local_event_queue ();
4253 /* Unblock target events for async mode. */
4255 sigprocmask (SIG_BLOCK
, &mask
, NULL
);
4257 /* Put events we already waited on, in the pipe first, so
4259 local_event_queue_to_pipe ();
4260 /* While in masked async, we may have not collected all
4261 the pending events. Get them out now. */
4262 get_pending_events ();
4265 sigaction (SIGCHLD
, &async_sigchld_action
, NULL
);
4266 sigprocmask (SIG_UNBLOCK
, &mask
, NULL
);
4269 case sigchld_default
:
4271 /* SIGCHLD default mode. */
4272 sigaction (SIGCHLD
, &sigchld_default_action
, NULL
);
4274 /* Get events out of queue, and make them available to
4275 queued_waitpid / my_waitpid. */
4276 pipe_to_local_event_queue ();
4278 /* Unblock SIGCHLD. */
4279 sigprocmask (SIG_UNBLOCK
, &mask
, NULL
);
4285 return current_state
;
4288 static int async_terminal_is_ours
= 1;
4290 /* target_terminal_inferior implementation. */
4293 linux_nat_terminal_inferior (void)
4295 if (!target_is_async_p ())
4297 /* Async mode is disabled. */
4298 terminal_inferior ();
4302 /* GDB should never give the terminal to the inferior, if the
4303 inferior is running in the background (run&, continue&, etc.).
4304 This check can be removed when the common code is fixed. */
4305 if (!sync_execution
)
4308 terminal_inferior ();
4310 if (!async_terminal_is_ours
)
4313 delete_file_handler (input_fd
);
4314 async_terminal_is_ours
= 0;
4318 /* target_terminal_ours implementation. */
4321 linux_nat_terminal_ours (void)
4323 if (!target_is_async_p ())
4325 /* Async mode is disabled. */
4330 /* GDB should never give the terminal to the inferior if the
4331 inferior is running in the background (run&, continue&, etc.),
4332 but claiming it sure should. */
4335 if (!sync_execution
)
4338 if (async_terminal_is_ours
)
4341 clear_sigint_trap ();
4342 add_file_handler (input_fd
, stdin_event_handler
, 0);
4343 async_terminal_is_ours
= 1;
4346 static void (*async_client_callback
) (enum inferior_event_type event_type
,
4348 static void *async_client_context
;
4351 linux_nat_async_file_handler (int error
, gdb_client_data client_data
)
4353 async_client_callback (INF_REG_EVENT
, async_client_context
);
4356 /* target_async implementation. */
4359 linux_nat_async (void (*callback
) (enum inferior_event_type event_type
,
4360 void *context
), void *context
)
4362 if (linux_nat_async_mask_value
== 0 || !target_async_permitted
)
4363 internal_error (__FILE__
, __LINE__
,
4364 "Calling target_async when async is masked");
4366 if (callback
!= NULL
)
4368 async_client_callback
= callback
;
4369 async_client_context
= context
;
4370 add_file_handler (linux_nat_event_pipe
[0],
4371 linux_nat_async_file_handler
, NULL
);
4373 linux_nat_async_events (sigchld_async
);
4377 async_client_callback
= callback
;
4378 async_client_context
= context
;
4380 linux_nat_async_events (sigchld_sync
);
4381 delete_file_handler (linux_nat_event_pipe
[0]);
4386 /* Stop an LWP, and push a TARGET_SIGNAL_0 stop status if no other
4390 linux_nat_stop_lwp (struct lwp_info
*lwp
, void *data
)
4392 ptid_t ptid
= * (ptid_t
*) data
;
4394 if (ptid_equal (lwp
->ptid
, ptid
)
4395 || ptid_equal (minus_one_ptid
, ptid
)
4396 || (ptid_is_pid (ptid
)
4397 && ptid_get_pid (ptid
) == ptid_get_pid (lwp
->ptid
)))
4403 if (debug_linux_nat
)
4404 fprintf_unfiltered (gdb_stdlog
,
4405 "LNSL: running -> suspending %s\n",
4406 target_pid_to_str (lwp
->ptid
));
4408 /* Peek once, to check if we've already waited for this
4410 pid
= queued_waitpid_1 (ptid_get_lwp (lwp
->ptid
), &status
,
4411 lwp
->cloned
? __WCLONE
: 0, 1 /* peek */);
4415 ptid_t ptid
= lwp
->ptid
;
4417 stop_callback (lwp
, NULL
);
4418 stop_wait_callback (lwp
, NULL
);
4420 /* If the lwp exits while we try to stop it, there's
4421 nothing else to do. */
4422 lwp
= find_lwp_pid (ptid
);
4426 pid
= queued_waitpid_1 (ptid_get_lwp (lwp
->ptid
), &status
,
4427 lwp
->cloned
? __WCLONE
: 0,
4431 /* If we didn't collect any signal other than SIGSTOP while
4432 stopping the LWP, push a SIGNAL_0 event. In either case,
4433 the event-loop will end up calling target_wait which will
4436 push_waitpid (ptid_get_lwp (lwp
->ptid
), W_STOPCODE (0),
4437 lwp
->cloned
? __WCLONE
: 0);
4441 /* Already known to be stopped; do nothing. */
4443 if (debug_linux_nat
)
4445 if (find_thread_pid (lwp
->ptid
)->stop_requested
)
4446 fprintf_unfiltered (gdb_stdlog
, "\
4447 LNSL: already stopped/stop_requested %s\n",
4448 target_pid_to_str (lwp
->ptid
));
4450 fprintf_unfiltered (gdb_stdlog
, "\
4451 LNSL: already stopped/no stop_requested yet %s\n",
4452 target_pid_to_str (lwp
->ptid
));
4460 linux_nat_stop (ptid_t ptid
)
4464 linux_nat_async_events (sigchld_sync
);
4465 iterate_over_lwps (linux_nat_stop_lwp
, &ptid
);
4466 target_async (inferior_event_handler
, 0);
4469 linux_ops
->to_stop (ptid
);
4473 linux_nat_add_target (struct target_ops
*t
)
4475 /* Save the provided single-threaded target. We save this in a separate
4476 variable because another target we've inherited from (e.g. inf-ptrace)
4477 may have saved a pointer to T; we want to use it for the final
4478 process stratum target. */
4479 linux_ops_saved
= *t
;
4480 linux_ops
= &linux_ops_saved
;
4482 /* Override some methods for multithreading. */
4483 t
->to_create_inferior
= linux_nat_create_inferior
;
4484 t
->to_attach
= linux_nat_attach
;
4485 t
->to_detach
= linux_nat_detach
;
4486 t
->to_resume
= linux_nat_resume
;
4487 t
->to_wait
= linux_nat_wait
;
4488 t
->to_xfer_partial
= linux_nat_xfer_partial
;
4489 t
->to_kill
= linux_nat_kill
;
4490 t
->to_mourn_inferior
= linux_nat_mourn_inferior
;
4491 t
->to_thread_alive
= linux_nat_thread_alive
;
4492 t
->to_pid_to_str
= linux_nat_pid_to_str
;
4493 t
->to_has_thread_control
= tc_schedlock
;
4495 t
->to_can_async_p
= linux_nat_can_async_p
;
4496 t
->to_is_async_p
= linux_nat_is_async_p
;
4497 t
->to_supports_non_stop
= linux_nat_supports_non_stop
;
4498 t
->to_async
= linux_nat_async
;
4499 t
->to_async_mask
= linux_nat_async_mask
;
4500 t
->to_terminal_inferior
= linux_nat_terminal_inferior
;
4501 t
->to_terminal_ours
= linux_nat_terminal_ours
;
4503 /* Methods for non-stop support. */
4504 t
->to_stop
= linux_nat_stop
;
4506 /* We don't change the stratum; this target will sit at
4507 process_stratum and thread_db will set at thread_stratum. This
4508 is a little strange, since this is a multi-threaded-capable
4509 target, but we want to be on the stack below thread_db, and we
4510 also want to be used for single-threaded processes. */
4514 /* TODO: Eliminate this and have libthread_db use
4515 find_target_beneath. */
4519 /* Register a method to call whenever a new thread is attached. */
4521 linux_nat_set_new_thread (struct target_ops
*t
, void (*new_thread
) (ptid_t
))
4523 /* Save the pointer. We only support a single registered instance
4524 of the GNU/Linux native target, so we do not need to map this to
4526 linux_nat_new_thread
= new_thread
;
4529 /* Return the saved siginfo associated with PTID. */
4531 linux_nat_get_siginfo (ptid_t ptid
)
4533 struct lwp_info
*lp
= find_lwp_pid (ptid
);
4535 gdb_assert (lp
!= NULL
);
4537 return &lp
->siginfo
;
4540 /* Enable/Disable async mode. */
4543 linux_nat_setup_async (void)
4545 if (pipe (linux_nat_event_pipe
) == -1)
4546 internal_error (__FILE__
, __LINE__
,
4547 "creating event pipe failed.");
4548 fcntl (linux_nat_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4549 fcntl (linux_nat_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4553 _initialize_linux_nat (void)
4557 add_info ("proc", linux_nat_info_proc_cmd
, _("\
4558 Show /proc process information about any running process.\n\
4559 Specify any process id, or use the program being debugged by default.\n\
4560 Specify any of the following keywords for detailed info:\n\
4561 mappings -- list of mapped memory regions.\n\
4562 stat -- list a bunch of random process info.\n\
4563 status -- list a different bunch of random process info.\n\
4564 all -- list all available /proc info."));
4566 add_setshow_zinteger_cmd ("lin-lwp", class_maintenance
,
4567 &debug_linux_nat
, _("\
4568 Set debugging of GNU/Linux lwp module."), _("\
4569 Show debugging of GNU/Linux lwp module."), _("\
4570 Enables printf debugging output."),
4572 show_debug_linux_nat
,
4573 &setdebuglist
, &showdebuglist
);
4575 add_setshow_zinteger_cmd ("lin-lwp-async", class_maintenance
,
4576 &debug_linux_nat_async
, _("\
4577 Set debugging of GNU/Linux async lwp module."), _("\
4578 Show debugging of GNU/Linux async lwp module."), _("\
4579 Enables printf debugging output."),
4581 show_debug_linux_nat_async
,
4582 &setdebuglist
, &showdebuglist
);
4584 /* Get the default SIGCHLD action. Used while forking an inferior
4585 (see linux_nat_create_inferior/linux_nat_async_events). */
4586 sigaction (SIGCHLD
, NULL
, &sigchld_default_action
);
4588 /* Block SIGCHLD by default. Doing this early prevents it getting
4589 unblocked if an exception is thrown due to an error while the
4590 inferior is starting (sigsetjmp/siglongjmp). */
4591 sigemptyset (&mask
);
4592 sigaddset (&mask
, SIGCHLD
);
4593 sigprocmask (SIG_BLOCK
, &mask
, NULL
);
4595 /* Save this mask as the default. */
4596 sigprocmask (SIG_SETMASK
, NULL
, &normal_mask
);
4598 /* The synchronous SIGCHLD handler. */
4599 sync_sigchld_action
.sa_handler
= sigchld_handler
;
4600 sigemptyset (&sync_sigchld_action
.sa_mask
);
4601 sync_sigchld_action
.sa_flags
= SA_RESTART
;
4603 /* Make it the default. */
4604 sigaction (SIGCHLD
, &sync_sigchld_action
, NULL
);
4606 /* Make sure we don't block SIGCHLD during a sigsuspend. */
4607 sigprocmask (SIG_SETMASK
, NULL
, &suspend_mask
);
4608 sigdelset (&suspend_mask
, SIGCHLD
);
4610 /* SIGCHLD handler for async mode. */
4611 async_sigchld_action
.sa_handler
= async_sigchld_handler
;
4612 sigemptyset (&async_sigchld_action
.sa_mask
);
4613 async_sigchld_action
.sa_flags
= SA_RESTART
;
4615 linux_nat_setup_async ();
4617 add_setshow_boolean_cmd ("disable-randomization", class_support
,
4618 &disable_randomization
, _("\
4619 Set disabling of debuggee's virtual address space randomization."), _("\
4620 Show disabling of debuggee's virtual address space randomization."), _("\
4621 When this mode is on (which is the default), randomization of the virtual\n\
4622 address space is disabled. Standalone programs run with the randomization\n\
4623 enabled by default on some platforms."),
4624 &set_disable_randomization
,
4625 &show_disable_randomization
,
4626 &setlist
, &showlist
);
4630 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
4631 the GNU/Linux Threads library and therefore doesn't really belong
4634 /* Read variable NAME in the target and return its value if found.
4635 Otherwise return zero. It is assumed that the type of the variable
4639 get_signo (const char *name
)
4641 struct minimal_symbol
*ms
;
4644 ms
= lookup_minimal_symbol (name
, NULL
, NULL
);
4648 if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms
), (gdb_byte
*) &signo
,
4649 sizeof (signo
)) != 0)
4655 /* Return the set of signals used by the threads library in *SET. */
4658 lin_thread_get_thread_signals (sigset_t
*set
)
4660 struct sigaction action
;
4661 int restart
, cancel
;
4662 sigset_t blocked_mask
;
4664 sigemptyset (&blocked_mask
);
4667 restart
= get_signo ("__pthread_sig_restart");
4668 cancel
= get_signo ("__pthread_sig_cancel");
4670 /* LinuxThreads normally uses the first two RT signals, but in some legacy
4671 cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
4672 not provide any way for the debugger to query the signal numbers -
4673 fortunately they don't change! */
4676 restart
= __SIGRTMIN
;
4679 cancel
= __SIGRTMIN
+ 1;
4681 sigaddset (set
, restart
);
4682 sigaddset (set
, cancel
);
4684 /* The GNU/Linux Threads library makes terminating threads send a
4685 special "cancel" signal instead of SIGCHLD. Make sure we catch
4686 those (to prevent them from terminating GDB itself, which is
4687 likely to be their default action) and treat them the same way as
4690 action
.sa_handler
= sigchld_handler
;
4691 sigemptyset (&action
.sa_mask
);
4692 action
.sa_flags
= SA_RESTART
;
4693 sigaction (cancel
, &action
, NULL
);
4695 /* We block the "cancel" signal throughout this code ... */
4696 sigaddset (&blocked_mask
, cancel
);
4697 sigprocmask (SIG_BLOCK
, &blocked_mask
, NULL
);
4699 /* ... except during a sigsuspend. */
4700 sigdelset (&suspend_mask
, cancel
);