1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001-2016 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "nat/linux-nat.h"
25 #include "nat/linux-waitpid.h"
28 #include <sys/syscall.h>
29 #include "nat/gdb_ptrace.h"
30 #include "linux-nat.h"
31 #include "nat/linux-ptrace.h"
32 #include "nat/linux-procfs.h"
33 #include "nat/linux-personality.h"
34 #include "linux-fork.h"
35 #include "gdbthread.h"
39 #include "inf-child.h"
40 #include "inf-ptrace.h"
42 #include <sys/procfs.h> /* for elf_gregset etc. */
43 #include "elf-bfd.h" /* for elfcore_write_* */
44 #include "gregset.h" /* for gregset */
45 #include "gdbcore.h" /* for get_exec_file */
46 #include <ctype.h> /* for isdigit */
47 #include <sys/stat.h> /* for struct stat */
48 #include <fcntl.h> /* for O_RDONLY */
50 #include "event-loop.h"
51 #include "event-top.h"
53 #include <sys/types.h>
55 #include "xml-support.h"
58 #include "nat/linux-osdata.h"
59 #include "linux-tdep.h"
62 #include "tracepoint.h"
64 #include "target-descriptions.h"
65 #include "filestuff.h"
67 #include "nat/linux-namespaces.h"
71 #define SPUFS_MAGIC 0x23c9b64e
74 /* This comment documents high-level logic of this file.
76 Waiting for events in sync mode
77 ===============================
79 When waiting for an event in a specific thread, we just use waitpid,
80 passing the specific pid, and not passing WNOHANG.
82 When waiting for an event in all threads, waitpid is not quite good:
84 - If the thread group leader exits while other threads in the thread
85 group still exist, waitpid(TGID, ...) hangs. That waitpid won't
86 return an exit status until the other threads in the group are
89 - When a non-leader thread execs, that thread just vanishes without
90 reporting an exit (so we'd hang if we waited for it explicitly in
91 that case). The exec event is instead reported to the TGID pid.
93 The solution is to always use -1 and WNOHANG, together with
96 First, we use non-blocking waitpid to check for events. If nothing is
97 found, we use sigsuspend to wait for SIGCHLD. When SIGCHLD arrives,
98 it means something happened to a child process. As soon as we know
99 there's an event, we get back to calling nonblocking waitpid.
101 Note that SIGCHLD should be blocked between waitpid and sigsuspend
102 calls, so that we don't miss a signal. If SIGCHLD arrives in between,
103 when it's blocked, the signal becomes pending and sigsuspend
104 immediately notices it and returns.
106 Waiting for events in async mode (TARGET_WNOHANG)
107 =================================================
109 In async mode, GDB should always be ready to handle both user input
110 and target events, so neither blocking waitpid nor sigsuspend are
111 viable options. Instead, we should asynchronously notify the GDB main
112 event loop whenever there's an unprocessed event from the target. We
113 detect asynchronous target events by handling SIGCHLD signals. To
114 notify the event loop about target events, the self-pipe trick is used
115 --- a pipe is registered as waitable event source in the event loop,
116 the event loop select/poll's on the read end of this pipe (as well on
117 other event sources, e.g., stdin), and the SIGCHLD handler writes a
118 byte to this pipe. This is more portable than relying on
119 pselect/ppoll, since on kernels that lack those syscalls, libc
120 emulates them with select/poll+sigprocmask, and that is racy
121 (a.k.a. plain broken).
123 Obviously, if we fail to notify the event loop if there's a target
124 event, it's bad. OTOH, if we notify the event loop when there's no
125 event from the target, linux_nat_wait will detect that there's no real
126 event to report, and return event of type TARGET_WAITKIND_IGNORE.
127 This is mostly harmless, but it will waste time and is better avoided.
129 The main design point is that every time GDB is outside linux-nat.c,
130 we have a SIGCHLD handler installed that is called when something
131 happens to the target and notifies the GDB event loop. Whenever GDB
132 core decides to handle the event, and calls into linux-nat.c, we
133 process things as in sync mode, except that the we never block in
136 While processing an event, we may end up momentarily blocked in
137 waitpid calls. Those waitpid calls, while blocking, are guarantied to
138 return quickly. E.g., in all-stop mode, before reporting to the core
139 that an LWP hit a breakpoint, all LWPs are stopped by sending them
140 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
141 Note that this is different from blocking indefinitely waiting for the
142 next event --- here, we're already handling an event.
147 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
148 signal is not entirely significant; we just need for a signal to be delivered,
149 so that we can intercept it. SIGSTOP's advantage is that it can not be
150 blocked. A disadvantage is that it is not a real-time signal, so it can only
151 be queued once; we do not keep track of other sources of SIGSTOP.
153 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
154 use them, because they have special behavior when the signal is generated -
155 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
156 kills the entire thread group.
158 A delivered SIGSTOP would stop the entire thread group, not just the thread we
159 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
160 cancel it (by PTRACE_CONT without passing SIGSTOP).
162 We could use a real-time signal instead. This would solve those problems; we
163 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
164 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
165 generates it, and there are races with trying to find a signal that is not
171 The case of a thread group (process) with 3 or more threads, and a
172 thread other than the leader execs is worth detailing:
174 On an exec, the Linux kernel destroys all threads except the execing
175 one in the thread group, and resets the execing thread's tid to the
176 tgid. No exit notification is sent for the execing thread -- from the
177 ptracer's perspective, it appears as though the execing thread just
178 vanishes. Until we reap all other threads except the leader and the
179 execing thread, the leader will be zombie, and the execing thread will
180 be in `D (disc sleep)' state. As soon as all other threads are
181 reaped, the execing thread changes its tid to the tgid, and the
182 previous (zombie) leader vanishes, giving place to the "new"
186 #define O_LARGEFILE 0
189 /* Does the current host support PTRACE_GETREGSET? */
190 enum tribool have_ptrace_getregset
= TRIBOOL_UNKNOWN
;
192 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
193 the use of the multi-threaded target. */
194 static struct target_ops
*linux_ops
;
195 static struct target_ops linux_ops_saved
;
197 /* The method to call, if any, when a new thread is attached. */
198 static void (*linux_nat_new_thread
) (struct lwp_info
*);
200 /* The method to call, if any, when a new fork is attached. */
201 static linux_nat_new_fork_ftype
*linux_nat_new_fork
;
203 /* The method to call, if any, when a process is no longer
205 static linux_nat_forget_process_ftype
*linux_nat_forget_process_hook
;
207 /* Hook to call prior to resuming a thread. */
208 static void (*linux_nat_prepare_to_resume
) (struct lwp_info
*);
210 /* The method to call, if any, when the siginfo object needs to be
211 converted between the layout returned by ptrace, and the layout in
212 the architecture of the inferior. */
213 static int (*linux_nat_siginfo_fixup
) (siginfo_t
*,
217 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
218 Called by our to_xfer_partial. */
219 static target_xfer_partial_ftype
*super_xfer_partial
;
221 /* The saved to_close method, inherited from inf-ptrace.c.
222 Called by our to_close. */
223 static void (*super_close
) (struct target_ops
*);
225 static unsigned int debug_linux_nat
;
227 show_debug_linux_nat (struct ui_file
*file
, int from_tty
,
228 struct cmd_list_element
*c
, const char *value
)
230 fprintf_filtered (file
, _("Debugging of GNU/Linux lwp module is %s.\n"),
234 struct simple_pid_list
238 struct simple_pid_list
*next
;
240 struct simple_pid_list
*stopped_pids
;
242 /* Whether target_thread_events is in effect. */
243 static int report_thread_events
;
245 /* Async mode support. */
247 /* The read/write ends of the pipe registered as waitable file in the
249 static int linux_nat_event_pipe
[2] = { -1, -1 };
251 /* True if we're currently in async mode. */
252 #define linux_is_async_p() (linux_nat_event_pipe[0] != -1)
254 /* Flush the event pipe. */
257 async_file_flush (void)
264 ret
= read (linux_nat_event_pipe
[0], &buf
, 1);
266 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
269 /* Put something (anything, doesn't matter what, or how much) in event
270 pipe, so that the select/poll in the event-loop realizes we have
271 something to process. */
274 async_file_mark (void)
278 /* It doesn't really matter what the pipe contains, as long we end
279 up with something in it. Might as well flush the previous
285 ret
= write (linux_nat_event_pipe
[1], "+", 1);
287 while (ret
== -1 && errno
== EINTR
);
289 /* Ignore EAGAIN. If the pipe is full, the event loop will already
290 be awakened anyway. */
293 static int kill_lwp (int lwpid
, int signo
);
295 static int stop_callback (struct lwp_info
*lp
, void *data
);
296 static int resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
);
298 static void block_child_signals (sigset_t
*prev_mask
);
299 static void restore_child_signals_mask (sigset_t
*prev_mask
);
302 static struct lwp_info
*add_lwp (ptid_t ptid
);
303 static void purge_lwp_list (int pid
);
304 static void delete_lwp (ptid_t ptid
);
305 static struct lwp_info
*find_lwp_pid (ptid_t ptid
);
307 static int lwp_status_pending_p (struct lwp_info
*lp
);
309 static int sigtrap_is_event (int status
);
310 static int (*linux_nat_status_is_event
) (int status
) = sigtrap_is_event
;
312 static void save_stop_reason (struct lwp_info
*lp
);
317 /* See nat/linux-nat.h. */
320 ptid_of_lwp (struct lwp_info
*lwp
)
325 /* See nat/linux-nat.h. */
328 lwp_set_arch_private_info (struct lwp_info
*lwp
,
329 struct arch_lwp_info
*info
)
331 lwp
->arch_private
= info
;
334 /* See nat/linux-nat.h. */
336 struct arch_lwp_info
*
337 lwp_arch_private_info (struct lwp_info
*lwp
)
339 return lwp
->arch_private
;
342 /* See nat/linux-nat.h. */
345 lwp_is_stopped (struct lwp_info
*lwp
)
350 /* See nat/linux-nat.h. */
352 enum target_stop_reason
353 lwp_stop_reason (struct lwp_info
*lwp
)
355 return lwp
->stop_reason
;
359 /* Trivial list manipulation functions to keep track of a list of
360 new stopped processes. */
362 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
364 struct simple_pid_list
*new_pid
= XNEW (struct simple_pid_list
);
367 new_pid
->status
= status
;
368 new_pid
->next
= *listp
;
373 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *statusp
)
375 struct simple_pid_list
**p
;
377 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
378 if ((*p
)->pid
== pid
)
380 struct simple_pid_list
*next
= (*p
)->next
;
382 *statusp
= (*p
)->status
;
390 /* Return the ptrace options that we want to try to enable. */
393 linux_nat_ptrace_options (int attached
)
398 options
|= PTRACE_O_EXITKILL
;
400 options
|= (PTRACE_O_TRACESYSGOOD
401 | PTRACE_O_TRACEVFORKDONE
402 | PTRACE_O_TRACEVFORK
404 | PTRACE_O_TRACEEXEC
);
409 /* Initialize ptrace warnings and check for supported ptrace
412 ATTACHED should be nonzero iff we attached to the inferior. */
415 linux_init_ptrace (pid_t pid
, int attached
)
417 int options
= linux_nat_ptrace_options (attached
);
419 linux_enable_event_reporting (pid
, options
);
420 linux_ptrace_init_warnings ();
424 linux_child_post_attach (struct target_ops
*self
, int pid
)
426 linux_init_ptrace (pid
, 1);
430 linux_child_post_startup_inferior (struct target_ops
*self
, ptid_t ptid
)
432 linux_init_ptrace (ptid_get_pid (ptid
), 0);
435 /* Return the number of known LWPs in the tgid given by PID. */
443 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
444 if (ptid_get_pid (lp
->ptid
) == pid
)
450 /* Call delete_lwp with prototype compatible for make_cleanup. */
453 delete_lwp_cleanup (void *lp_voidp
)
455 struct lwp_info
*lp
= (struct lwp_info
*) lp_voidp
;
457 delete_lwp (lp
->ptid
);
460 /* Target hook for follow_fork. On entry inferior_ptid must be the
461 ptid of the followed inferior. At return, inferior_ptid will be
465 linux_child_follow_fork (struct target_ops
*ops
, int follow_child
,
470 struct lwp_info
*child_lp
= NULL
;
471 int status
= W_STOPCODE (0);
472 struct cleanup
*old_chain
;
474 ptid_t parent_ptid
, child_ptid
;
475 int parent_pid
, child_pid
;
477 has_vforked
= (inferior_thread ()->pending_follow
.kind
478 == TARGET_WAITKIND_VFORKED
);
479 parent_ptid
= inferior_ptid
;
480 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
481 parent_pid
= ptid_get_lwp (parent_ptid
);
482 child_pid
= ptid_get_lwp (child_ptid
);
484 /* We're already attached to the parent, by default. */
485 old_chain
= save_inferior_ptid ();
486 inferior_ptid
= child_ptid
;
487 child_lp
= add_lwp (inferior_ptid
);
488 child_lp
->stopped
= 1;
489 child_lp
->last_resume_kind
= resume_stop
;
491 /* Detach new forked process? */
494 make_cleanup (delete_lwp_cleanup
, child_lp
);
496 if (linux_nat_prepare_to_resume
!= NULL
)
497 linux_nat_prepare_to_resume (child_lp
);
499 /* When debugging an inferior in an architecture that supports
500 hardware single stepping on a kernel without commit
501 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child
502 process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits
503 set if the parent process had them set.
504 To work around this, single step the child process
505 once before detaching to clear the flags. */
507 if (!gdbarch_software_single_step_p (target_thread_architecture
510 linux_disable_event_reporting (child_pid
);
511 if (ptrace (PTRACE_SINGLESTEP
, child_pid
, 0, 0) < 0)
512 perror_with_name (_("Couldn't do single step"));
513 if (my_waitpid (child_pid
, &status
, 0) < 0)
514 perror_with_name (_("Couldn't wait vfork process"));
517 if (WIFSTOPPED (status
))
521 signo
= WSTOPSIG (status
);
523 && !signal_pass_state (gdb_signal_from_host (signo
)))
525 ptrace (PTRACE_DETACH
, child_pid
, 0, signo
);
528 /* Resets value of inferior_ptid to parent ptid. */
529 do_cleanups (old_chain
);
533 /* Let the thread_db layer learn about this new process. */
534 check_for_thread_db ();
537 do_cleanups (old_chain
);
541 struct lwp_info
*parent_lp
;
543 parent_lp
= find_lwp_pid (parent_ptid
);
544 gdb_assert (linux_supports_tracefork () >= 0);
546 if (linux_supports_tracevforkdone ())
549 fprintf_unfiltered (gdb_stdlog
,
550 "LCFF: waiting for VFORK_DONE on %d\n",
552 parent_lp
->stopped
= 1;
554 /* We'll handle the VFORK_DONE event like any other
555 event, in target_wait. */
559 /* We can't insert breakpoints until the child has
560 finished with the shared memory region. We need to
561 wait until that happens. Ideal would be to just
563 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
564 - waitpid (parent_pid, &status, __WALL);
565 However, most architectures can't handle a syscall
566 being traced on the way out if it wasn't traced on
569 We might also think to loop, continuing the child
570 until it exits or gets a SIGTRAP. One problem is
571 that the child might call ptrace with PTRACE_TRACEME.
573 There's no simple and reliable way to figure out when
574 the vforked child will be done with its copy of the
575 shared memory. We could step it out of the syscall,
576 two instructions, let it go, and then single-step the
577 parent once. When we have hardware single-step, this
578 would work; with software single-step it could still
579 be made to work but we'd have to be able to insert
580 single-step breakpoints in the child, and we'd have
581 to insert -just- the single-step breakpoint in the
582 parent. Very awkward.
584 In the end, the best we can do is to make sure it
585 runs for a little while. Hopefully it will be out of
586 range of any breakpoints we reinsert. Usually this
587 is only the single-step breakpoint at vfork's return
591 fprintf_unfiltered (gdb_stdlog
,
592 "LCFF: no VFORK_DONE "
593 "support, sleeping a bit\n");
597 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
598 and leave it pending. The next linux_nat_resume call
599 will notice a pending event, and bypasses actually
600 resuming the inferior. */
601 parent_lp
->status
= 0;
602 parent_lp
->waitstatus
.kind
= TARGET_WAITKIND_VFORK_DONE
;
603 parent_lp
->stopped
= 1;
605 /* If we're in async mode, need to tell the event loop
606 there's something here to process. */
607 if (target_is_async_p ())
614 struct lwp_info
*child_lp
;
616 child_lp
= add_lwp (inferior_ptid
);
617 child_lp
->stopped
= 1;
618 child_lp
->last_resume_kind
= resume_stop
;
620 /* Let the thread_db layer learn about this new process. */
621 check_for_thread_db ();
629 linux_child_insert_fork_catchpoint (struct target_ops
*self
, int pid
)
631 return !linux_supports_tracefork ();
635 linux_child_remove_fork_catchpoint (struct target_ops
*self
, int pid
)
641 linux_child_insert_vfork_catchpoint (struct target_ops
*self
, int pid
)
643 return !linux_supports_tracefork ();
647 linux_child_remove_vfork_catchpoint (struct target_ops
*self
, int pid
)
653 linux_child_insert_exec_catchpoint (struct target_ops
*self
, int pid
)
655 return !linux_supports_tracefork ();
659 linux_child_remove_exec_catchpoint (struct target_ops
*self
, int pid
)
665 linux_child_set_syscall_catchpoint (struct target_ops
*self
,
666 int pid
, int needed
, int any_count
,
667 int table_size
, int *table
)
669 if (!linux_supports_tracesysgood ())
672 /* On GNU/Linux, we ignore the arguments. It means that we only
673 enable the syscall catchpoints, but do not disable them.
675 Also, we do not use the `table' information because we do not
676 filter system calls here. We let GDB do the logic for us. */
680 /* List of known LWPs. */
681 struct lwp_info
*lwp_list
;
684 /* Original signal mask. */
685 static sigset_t normal_mask
;
687 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
688 _initialize_linux_nat. */
689 static sigset_t suspend_mask
;
691 /* Signals to block to make that sigsuspend work. */
692 static sigset_t blocked_mask
;
694 /* SIGCHLD action. */
695 struct sigaction sigchld_action
;
697 /* Block child signals (SIGCHLD and linux threads signals), and store
698 the previous mask in PREV_MASK. */
701 block_child_signals (sigset_t
*prev_mask
)
703 /* Make sure SIGCHLD is blocked. */
704 if (!sigismember (&blocked_mask
, SIGCHLD
))
705 sigaddset (&blocked_mask
, SIGCHLD
);
707 sigprocmask (SIG_BLOCK
, &blocked_mask
, prev_mask
);
710 /* Restore child signals mask, previously returned by
711 block_child_signals. */
714 restore_child_signals_mask (sigset_t
*prev_mask
)
716 sigprocmask (SIG_SETMASK
, prev_mask
, NULL
);
719 /* Mask of signals to pass directly to the inferior. */
720 static sigset_t pass_mask
;
722 /* Update signals to pass to the inferior. */
724 linux_nat_pass_signals (struct target_ops
*self
,
725 int numsigs
, unsigned char *pass_signals
)
729 sigemptyset (&pass_mask
);
731 for (signo
= 1; signo
< NSIG
; signo
++)
733 int target_signo
= gdb_signal_from_host (signo
);
734 if (target_signo
< numsigs
&& pass_signals
[target_signo
])
735 sigaddset (&pass_mask
, signo
);
741 /* Prototypes for local functions. */
742 static int stop_wait_callback (struct lwp_info
*lp
, void *data
);
743 static char *linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
);
744 static int resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
);
748 /* Destroy and free LP. */
751 lwp_free (struct lwp_info
*lp
)
753 xfree (lp
->arch_private
);
757 /* Remove all LWPs belong to PID from the lwp list. */
760 purge_lwp_list (int pid
)
762 struct lwp_info
*lp
, *lpprev
, *lpnext
;
766 for (lp
= lwp_list
; lp
; lp
= lpnext
)
770 if (ptid_get_pid (lp
->ptid
) == pid
)
775 lpprev
->next
= lp
->next
;
784 /* Add the LWP specified by PTID to the list. PTID is the first LWP
785 in the process. Return a pointer to the structure describing the
788 This differs from add_lwp in that we don't let the arch specific
789 bits know about this new thread. Current clients of this callback
790 take the opportunity to install watchpoints in the new thread, and
791 we shouldn't do that for the first thread. If we're spawning a
792 child ("run"), the thread executes the shell wrapper first, and we
793 shouldn't touch it until it execs the program we want to debug.
794 For "attach", it'd be okay to call the callback, but it's not
795 necessary, because watchpoints can't yet have been inserted into
798 static struct lwp_info
*
799 add_initial_lwp (ptid_t ptid
)
803 gdb_assert (ptid_lwp_p (ptid
));
805 lp
= XNEW (struct lwp_info
);
807 memset (lp
, 0, sizeof (struct lwp_info
));
809 lp
->last_resume_kind
= resume_continue
;
810 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
821 /* Add the LWP specified by PID to the list. Return a pointer to the
822 structure describing the new LWP. The LWP should already be
825 static struct lwp_info
*
826 add_lwp (ptid_t ptid
)
830 lp
= add_initial_lwp (ptid
);
832 /* Let the arch specific bits know about this new thread. Current
833 clients of this callback take the opportunity to install
834 watchpoints in the new thread. We don't do this for the first
835 thread though. See add_initial_lwp. */
836 if (linux_nat_new_thread
!= NULL
)
837 linux_nat_new_thread (lp
);
842 /* Remove the LWP specified by PID from the list. */
845 delete_lwp (ptid_t ptid
)
847 struct lwp_info
*lp
, *lpprev
;
851 for (lp
= lwp_list
; lp
; lpprev
= lp
, lp
= lp
->next
)
852 if (ptid_equal (lp
->ptid
, ptid
))
859 lpprev
->next
= lp
->next
;
866 /* Return a pointer to the structure describing the LWP corresponding
867 to PID. If no corresponding LWP could be found, return NULL. */
869 static struct lwp_info
*
870 find_lwp_pid (ptid_t ptid
)
875 if (ptid_lwp_p (ptid
))
876 lwp
= ptid_get_lwp (ptid
);
878 lwp
= ptid_get_pid (ptid
);
880 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
881 if (lwp
== ptid_get_lwp (lp
->ptid
))
887 /* See nat/linux-nat.h. */
890 iterate_over_lwps (ptid_t filter
,
891 iterate_over_lwps_ftype callback
,
894 struct lwp_info
*lp
, *lpnext
;
896 for (lp
= lwp_list
; lp
; lp
= lpnext
)
900 if (ptid_match (lp
->ptid
, filter
))
902 if ((*callback
) (lp
, data
) != 0)
910 /* Update our internal state when changing from one checkpoint to
911 another indicated by NEW_PTID. We can only switch single-threaded
912 applications, so we only create one new LWP, and the previous list
916 linux_nat_switch_fork (ptid_t new_ptid
)
920 purge_lwp_list (ptid_get_pid (inferior_ptid
));
922 lp
= add_lwp (new_ptid
);
925 /* This changes the thread's ptid while preserving the gdb thread
926 num. Also changes the inferior pid, while preserving the
928 thread_change_ptid (inferior_ptid
, new_ptid
);
930 /* We've just told GDB core that the thread changed target id, but,
931 in fact, it really is a different thread, with different register
933 registers_changed ();
936 /* Handle the exit of a single thread LP. */
939 exit_lwp (struct lwp_info
*lp
)
941 struct thread_info
*th
= find_thread_ptid (lp
->ptid
);
945 if (print_thread_events
)
946 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp
->ptid
));
948 delete_thread (lp
->ptid
);
951 delete_lwp (lp
->ptid
);
954 /* Wait for the LWP specified by LP, which we have just attached to.
955 Returns a wait status for that LWP, to cache. */
958 linux_nat_post_attach_wait (ptid_t ptid
, int first
, int *signalled
)
960 pid_t new_pid
, pid
= ptid_get_lwp (ptid
);
963 if (linux_proc_pid_is_stopped (pid
))
966 fprintf_unfiltered (gdb_stdlog
,
967 "LNPAW: Attaching to a stopped process\n");
969 /* The process is definitely stopped. It is in a job control
970 stop, unless the kernel predates the TASK_STOPPED /
971 TASK_TRACED distinction, in which case it might be in a
972 ptrace stop. Make sure it is in a ptrace stop; from there we
973 can kill it, signal it, et cetera.
975 First make sure there is a pending SIGSTOP. Since we are
976 already attached, the process can not transition from stopped
977 to running without a PTRACE_CONT; so we know this signal will
978 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
979 probably already in the queue (unless this kernel is old
980 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
981 is not an RT signal, it can only be queued once. */
982 kill_lwp (pid
, SIGSTOP
);
984 /* Finally, resume the stopped process. This will deliver the SIGSTOP
985 (or a higher priority signal, just like normal PTRACE_ATTACH). */
986 ptrace (PTRACE_CONT
, pid
, 0, 0);
989 /* Make sure the initial process is stopped. The user-level threads
990 layer might want to poke around in the inferior, and that won't
991 work if things haven't stabilized yet. */
992 new_pid
= my_waitpid (pid
, &status
, __WALL
);
993 gdb_assert (pid
== new_pid
);
995 if (!WIFSTOPPED (status
))
997 /* The pid we tried to attach has apparently just exited. */
999 fprintf_unfiltered (gdb_stdlog
, "LNPAW: Failed to stop %d: %s",
1000 pid
, status_to_str (status
));
1004 if (WSTOPSIG (status
) != SIGSTOP
)
1007 if (debug_linux_nat
)
1008 fprintf_unfiltered (gdb_stdlog
,
1009 "LNPAW: Received %s after attaching\n",
1010 status_to_str (status
));
1017 linux_nat_create_inferior (struct target_ops
*ops
,
1018 char *exec_file
, char *allargs
, char **env
,
1021 struct cleanup
*restore_personality
1022 = maybe_disable_address_space_randomization (disable_randomization
);
1024 /* The fork_child mechanism is synchronous and calls target_wait, so
1025 we have to mask the async mode. */
1027 /* Make sure we report all signals during startup. */
1028 linux_nat_pass_signals (ops
, 0, NULL
);
1030 linux_ops
->to_create_inferior (ops
, exec_file
, allargs
, env
, from_tty
);
1032 do_cleanups (restore_personality
);
1035 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
1036 already attached. Returns true if a new LWP is found, false
1040 attach_proc_task_lwp_callback (ptid_t ptid
)
1042 struct lwp_info
*lp
;
1044 /* Ignore LWPs we're already attached to. */
1045 lp
= find_lwp_pid (ptid
);
1048 int lwpid
= ptid_get_lwp (ptid
);
1050 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) < 0)
1054 /* Be quiet if we simply raced with the thread exiting.
1055 EPERM is returned if the thread's task still exists, and
1056 is marked as exited or zombie, as well as other
1057 conditions, so in that case, confirm the status in
1058 /proc/PID/status. */
1060 || (err
== EPERM
&& linux_proc_pid_is_gone (lwpid
)))
1062 if (debug_linux_nat
)
1064 fprintf_unfiltered (gdb_stdlog
,
1065 "Cannot attach to lwp %d: "
1066 "thread is gone (%d: %s)\n",
1067 lwpid
, err
, safe_strerror (err
));
1072 warning (_("Cannot attach to lwp %d: %s"),
1074 linux_ptrace_attach_fail_reason_string (ptid
,
1080 if (debug_linux_nat
)
1081 fprintf_unfiltered (gdb_stdlog
,
1082 "PTRACE_ATTACH %s, 0, 0 (OK)\n",
1083 target_pid_to_str (ptid
));
1085 lp
= add_lwp (ptid
);
1087 /* The next time we wait for this LWP we'll see a SIGSTOP as
1088 PTRACE_ATTACH brings it to a halt. */
1091 /* We need to wait for a stop before being able to make the
1092 next ptrace call on this LWP. */
1093 lp
->must_set_ptrace_flags
= 1;
1102 linux_nat_attach (struct target_ops
*ops
, const char *args
, int from_tty
)
1104 struct lwp_info
*lp
;
1108 /* Make sure we report all signals during attach. */
1109 linux_nat_pass_signals (ops
, 0, NULL
);
1113 linux_ops
->to_attach (ops
, args
, from_tty
);
1115 CATCH (ex
, RETURN_MASK_ERROR
)
1117 pid_t pid
= parse_pid_to_attach (args
);
1118 struct buffer buffer
;
1119 char *message
, *buffer_s
;
1121 message
= xstrdup (ex
.message
);
1122 make_cleanup (xfree
, message
);
1124 buffer_init (&buffer
);
1125 linux_ptrace_attach_fail_reason (pid
, &buffer
);
1127 buffer_grow_str0 (&buffer
, "");
1128 buffer_s
= buffer_finish (&buffer
);
1129 make_cleanup (xfree
, buffer_s
);
1131 if (*buffer_s
!= '\0')
1132 throw_error (ex
.error
, "warning: %s\n%s", buffer_s
, message
);
1134 throw_error (ex
.error
, "%s", message
);
1138 /* The ptrace base target adds the main thread with (pid,0,0)
1139 format. Decorate it with lwp info. */
1140 ptid
= ptid_build (ptid_get_pid (inferior_ptid
),
1141 ptid_get_pid (inferior_ptid
),
1143 thread_change_ptid (inferior_ptid
, ptid
);
1145 /* Add the initial process as the first LWP to the list. */
1146 lp
= add_initial_lwp (ptid
);
1148 status
= linux_nat_post_attach_wait (lp
->ptid
, 1, &lp
->signalled
);
1149 if (!WIFSTOPPED (status
))
1151 if (WIFEXITED (status
))
1153 int exit_code
= WEXITSTATUS (status
);
1155 target_terminal_ours ();
1156 target_mourn_inferior ();
1158 error (_("Unable to attach: program exited normally."));
1160 error (_("Unable to attach: program exited with code %d."),
1163 else if (WIFSIGNALED (status
))
1165 enum gdb_signal signo
;
1167 target_terminal_ours ();
1168 target_mourn_inferior ();
1170 signo
= gdb_signal_from_host (WTERMSIG (status
));
1171 error (_("Unable to attach: program terminated with signal "
1173 gdb_signal_to_name (signo
),
1174 gdb_signal_to_string (signo
));
1177 internal_error (__FILE__
, __LINE__
,
1178 _("unexpected status %d for PID %ld"),
1179 status
, (long) ptid_get_lwp (ptid
));
1184 /* Save the wait status to report later. */
1186 if (debug_linux_nat
)
1187 fprintf_unfiltered (gdb_stdlog
,
1188 "LNA: waitpid %ld, saving status %s\n",
1189 (long) ptid_get_pid (lp
->ptid
), status_to_str (status
));
1191 lp
->status
= status
;
1193 /* We must attach to every LWP. If /proc is mounted, use that to
1194 find them now. The inferior may be using raw clone instead of
1195 using pthreads. But even if it is using pthreads, thread_db
1196 walks structures in the inferior's address space to find the list
1197 of threads/LWPs, and those structures may well be corrupted.
1198 Note that once thread_db is loaded, we'll still use it to list
1199 threads and associate pthread info with each LWP. */
1200 linux_proc_attach_tgid_threads (ptid_get_pid (lp
->ptid
),
1201 attach_proc_task_lwp_callback
);
1203 if (target_can_async_p ())
1207 /* Get pending status of LP. */
1209 get_pending_status (struct lwp_info
*lp
, int *status
)
1211 enum gdb_signal signo
= GDB_SIGNAL_0
;
1213 /* If we paused threads momentarily, we may have stored pending
1214 events in lp->status or lp->waitstatus (see stop_wait_callback),
1215 and GDB core hasn't seen any signal for those threads.
1216 Otherwise, the last signal reported to the core is found in the
1217 thread object's stop_signal.
1219 There's a corner case that isn't handled here at present. Only
1220 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1221 stop_signal make sense as a real signal to pass to the inferior.
1222 Some catchpoint related events, like
1223 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1224 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1225 those traps are debug API (ptrace in our case) related and
1226 induced; the inferior wouldn't see them if it wasn't being
1227 traced. Hence, we should never pass them to the inferior, even
1228 when set to pass state. Since this corner case isn't handled by
1229 infrun.c when proceeding with a signal, for consistency, neither
1230 do we handle it here (or elsewhere in the file we check for
1231 signal pass state). Normally SIGTRAP isn't set to pass state, so
1232 this is really a corner case. */
1234 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
1235 signo
= GDB_SIGNAL_0
; /* a pending ptrace event, not a real signal. */
1236 else if (lp
->status
)
1237 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1238 else if (target_is_non_stop_p () && !is_executing (lp
->ptid
))
1240 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1242 signo
= tp
->suspend
.stop_signal
;
1244 else if (!target_is_non_stop_p ())
1246 struct target_waitstatus last
;
1249 get_last_target_status (&last_ptid
, &last
);
1251 if (ptid_get_lwp (lp
->ptid
) == ptid_get_lwp (last_ptid
))
1253 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1255 signo
= tp
->suspend
.stop_signal
;
1261 if (signo
== GDB_SIGNAL_0
)
1263 if (debug_linux_nat
)
1264 fprintf_unfiltered (gdb_stdlog
,
1265 "GPT: lwp %s has no pending signal\n",
1266 target_pid_to_str (lp
->ptid
));
1268 else if (!signal_pass_state (signo
))
1270 if (debug_linux_nat
)
1271 fprintf_unfiltered (gdb_stdlog
,
1272 "GPT: lwp %s had signal %s, "
1273 "but it is in no pass state\n",
1274 target_pid_to_str (lp
->ptid
),
1275 gdb_signal_to_string (signo
));
1279 *status
= W_STOPCODE (gdb_signal_to_host (signo
));
1281 if (debug_linux_nat
)
1282 fprintf_unfiltered (gdb_stdlog
,
1283 "GPT: lwp %s has pending signal %s\n",
1284 target_pid_to_str (lp
->ptid
),
1285 gdb_signal_to_string (signo
));
1292 detach_callback (struct lwp_info
*lp
, void *data
)
1294 gdb_assert (lp
->status
== 0 || WIFSTOPPED (lp
->status
));
1296 if (debug_linux_nat
&& lp
->status
)
1297 fprintf_unfiltered (gdb_stdlog
, "DC: Pending %s for %s on detach.\n",
1298 strsignal (WSTOPSIG (lp
->status
)),
1299 target_pid_to_str (lp
->ptid
));
1301 /* If there is a pending SIGSTOP, get rid of it. */
1304 if (debug_linux_nat
)
1305 fprintf_unfiltered (gdb_stdlog
,
1306 "DC: Sending SIGCONT to %s\n",
1307 target_pid_to_str (lp
->ptid
));
1309 kill_lwp (ptid_get_lwp (lp
->ptid
), SIGCONT
);
1313 /* We don't actually detach from the LWP that has an id equal to the
1314 overall process id just yet. */
1315 if (ptid_get_lwp (lp
->ptid
) != ptid_get_pid (lp
->ptid
))
1319 /* Pass on any pending signal for this LWP. */
1320 get_pending_status (lp
, &status
);
1322 if (linux_nat_prepare_to_resume
!= NULL
)
1323 linux_nat_prepare_to_resume (lp
);
1325 if (ptrace (PTRACE_DETACH
, ptid_get_lwp (lp
->ptid
), 0,
1326 WSTOPSIG (status
)) < 0)
1327 error (_("Can't detach %s: %s"), target_pid_to_str (lp
->ptid
),
1328 safe_strerror (errno
));
1330 if (debug_linux_nat
)
1331 fprintf_unfiltered (gdb_stdlog
,
1332 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1333 target_pid_to_str (lp
->ptid
),
1334 strsignal (WSTOPSIG (status
)));
1336 delete_lwp (lp
->ptid
);
1343 linux_nat_detach (struct target_ops
*ops
, const char *args
, int from_tty
)
1347 struct lwp_info
*main_lwp
;
1349 pid
= ptid_get_pid (inferior_ptid
);
1351 /* Don't unregister from the event loop, as there may be other
1352 inferiors running. */
1354 /* Stop all threads before detaching. ptrace requires that the
1355 thread is stopped to sucessfully detach. */
1356 iterate_over_lwps (pid_to_ptid (pid
), stop_callback
, NULL
);
1357 /* ... and wait until all of them have reported back that
1358 they're no longer running. */
1359 iterate_over_lwps (pid_to_ptid (pid
), stop_wait_callback
, NULL
);
1361 iterate_over_lwps (pid_to_ptid (pid
), detach_callback
, NULL
);
1363 /* Only the initial process should be left right now. */
1364 gdb_assert (num_lwps (ptid_get_pid (inferior_ptid
)) == 1);
1366 main_lwp
= find_lwp_pid (pid_to_ptid (pid
));
1368 /* Pass on any pending signal for the last LWP. */
1369 if ((args
== NULL
|| *args
== '\0')
1370 && get_pending_status (main_lwp
, &status
) != -1
1371 && WIFSTOPPED (status
))
1375 /* Put the signal number in ARGS so that inf_ptrace_detach will
1376 pass it along with PTRACE_DETACH. */
1377 tem
= (char *) alloca (8);
1378 xsnprintf (tem
, 8, "%d", (int) WSTOPSIG (status
));
1380 if (debug_linux_nat
)
1381 fprintf_unfiltered (gdb_stdlog
,
1382 "LND: Sending signal %s to %s\n",
1384 target_pid_to_str (main_lwp
->ptid
));
1387 if (linux_nat_prepare_to_resume
!= NULL
)
1388 linux_nat_prepare_to_resume (main_lwp
);
1389 delete_lwp (main_lwp
->ptid
);
1391 if (forks_exist_p ())
1393 /* Multi-fork case. The current inferior_ptid is being detached
1394 from, but there are other viable forks to debug. Detach from
1395 the current fork, and context-switch to the first
1397 linux_fork_detach (args
, from_tty
);
1400 linux_ops
->to_detach (ops
, args
, from_tty
);
1403 /* Resume execution of the inferior process. If STEP is nonzero,
1404 single-step it. If SIGNAL is nonzero, give it that signal. */
1407 linux_resume_one_lwp_throw (struct lwp_info
*lp
, int step
,
1408 enum gdb_signal signo
)
1412 /* stop_pc doubles as the PC the LWP had when it was last resumed.
1413 We only presently need that if the LWP is stepped though (to
1414 handle the case of stepping a breakpoint instruction). */
1417 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
1419 lp
->stop_pc
= regcache_read_pc (regcache
);
1424 if (linux_nat_prepare_to_resume
!= NULL
)
1425 linux_nat_prepare_to_resume (lp
);
1426 linux_ops
->to_resume (linux_ops
, lp
->ptid
, step
, signo
);
1428 /* Successfully resumed. Clear state that no longer makes sense,
1429 and mark the LWP as running. Must not do this before resuming
1430 otherwise if that fails other code will be confused. E.g., we'd
1431 later try to stop the LWP and hang forever waiting for a stop
1432 status. Note that we must not throw after this is cleared,
1433 otherwise handle_zombie_lwp_error would get confused. */
1435 lp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
1436 registers_changed_ptid (lp
->ptid
);
1439 /* Called when we try to resume a stopped LWP and that errors out. If
1440 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
1441 or about to become), discard the error, clear any pending status
1442 the LWP may have, and return true (we'll collect the exit status
1443 soon enough). Otherwise, return false. */
1446 check_ptrace_stopped_lwp_gone (struct lwp_info
*lp
)
1448 /* If we get an error after resuming the LWP successfully, we'd
1449 confuse !T state for the LWP being gone. */
1450 gdb_assert (lp
->stopped
);
1452 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
1453 because even if ptrace failed with ESRCH, the tracee may be "not
1454 yet fully dead", but already refusing ptrace requests. In that
1455 case the tracee has 'R (Running)' state for a little bit
1456 (observed in Linux 3.18). See also the note on ESRCH in the
1457 ptrace(2) man page. Instead, check whether the LWP has any state
1458 other than ptrace-stopped. */
1460 /* Don't assume anything if /proc/PID/status can't be read. */
1461 if (linux_proc_pid_is_trace_stopped_nowarn (ptid_get_lwp (lp
->ptid
)) == 0)
1463 lp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
1465 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
1471 /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
1472 disappears while we try to resume it. */
1475 linux_resume_one_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1479 linux_resume_one_lwp_throw (lp
, step
, signo
);
1481 CATCH (ex
, RETURN_MASK_ERROR
)
1483 if (!check_ptrace_stopped_lwp_gone (lp
))
1484 throw_exception (ex
);
1492 resume_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1496 struct inferior
*inf
= find_inferior_ptid (lp
->ptid
);
1498 if (inf
->vfork_child
!= NULL
)
1500 if (debug_linux_nat
)
1501 fprintf_unfiltered (gdb_stdlog
,
1502 "RC: Not resuming %s (vfork parent)\n",
1503 target_pid_to_str (lp
->ptid
));
1505 else if (!lwp_status_pending_p (lp
))
1507 if (debug_linux_nat
)
1508 fprintf_unfiltered (gdb_stdlog
,
1509 "RC: Resuming sibling %s, %s, %s\n",
1510 target_pid_to_str (lp
->ptid
),
1511 (signo
!= GDB_SIGNAL_0
1512 ? strsignal (gdb_signal_to_host (signo
))
1514 step
? "step" : "resume");
1516 linux_resume_one_lwp (lp
, step
, signo
);
1520 if (debug_linux_nat
)
1521 fprintf_unfiltered (gdb_stdlog
,
1522 "RC: Not resuming sibling %s (has pending)\n",
1523 target_pid_to_str (lp
->ptid
));
1528 if (debug_linux_nat
)
1529 fprintf_unfiltered (gdb_stdlog
,
1530 "RC: Not resuming sibling %s (not stopped)\n",
1531 target_pid_to_str (lp
->ptid
));
1535 /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing.
1536 Resume LWP with the last stop signal, if it is in pass state. */
1539 linux_nat_resume_callback (struct lwp_info
*lp
, void *except
)
1541 enum gdb_signal signo
= GDB_SIGNAL_0
;
1548 struct thread_info
*thread
;
1550 thread
= find_thread_ptid (lp
->ptid
);
1553 signo
= thread
->suspend
.stop_signal
;
1554 thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
1558 resume_lwp (lp
, 0, signo
);
1563 resume_clear_callback (struct lwp_info
*lp
, void *data
)
1566 lp
->last_resume_kind
= resume_stop
;
1571 resume_set_callback (struct lwp_info
*lp
, void *data
)
1574 lp
->last_resume_kind
= resume_continue
;
1579 linux_nat_resume (struct target_ops
*ops
,
1580 ptid_t ptid
, int step
, enum gdb_signal signo
)
1582 struct lwp_info
*lp
;
1585 if (debug_linux_nat
)
1586 fprintf_unfiltered (gdb_stdlog
,
1587 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1588 step
? "step" : "resume",
1589 target_pid_to_str (ptid
),
1590 (signo
!= GDB_SIGNAL_0
1591 ? strsignal (gdb_signal_to_host (signo
)) : "0"),
1592 target_pid_to_str (inferior_ptid
));
1594 /* A specific PTID means `step only this process id'. */
1595 resume_many
= (ptid_equal (minus_one_ptid
, ptid
)
1596 || ptid_is_pid (ptid
));
1598 /* Mark the lwps we're resuming as resumed. */
1599 iterate_over_lwps (ptid
, resume_set_callback
, NULL
);
1601 /* See if it's the current inferior that should be handled
1604 lp
= find_lwp_pid (inferior_ptid
);
1606 lp
= find_lwp_pid (ptid
);
1607 gdb_assert (lp
!= NULL
);
1609 /* Remember if we're stepping. */
1610 lp
->last_resume_kind
= step
? resume_step
: resume_continue
;
1612 /* If we have a pending wait status for this thread, there is no
1613 point in resuming the process. But first make sure that
1614 linux_nat_wait won't preemptively handle the event - we
1615 should never take this short-circuit if we are going to
1616 leave LP running, since we have skipped resuming all the
1617 other threads. This bit of code needs to be synchronized
1618 with linux_nat_wait. */
1620 if (lp
->status
&& WIFSTOPPED (lp
->status
))
1623 && WSTOPSIG (lp
->status
)
1624 && sigismember (&pass_mask
, WSTOPSIG (lp
->status
)))
1626 if (debug_linux_nat
)
1627 fprintf_unfiltered (gdb_stdlog
,
1628 "LLR: Not short circuiting for ignored "
1629 "status 0x%x\n", lp
->status
);
1631 /* FIXME: What should we do if we are supposed to continue
1632 this thread with a signal? */
1633 gdb_assert (signo
== GDB_SIGNAL_0
);
1634 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1639 if (lwp_status_pending_p (lp
))
1641 /* FIXME: What should we do if we are supposed to continue
1642 this thread with a signal? */
1643 gdb_assert (signo
== GDB_SIGNAL_0
);
1645 if (debug_linux_nat
)
1646 fprintf_unfiltered (gdb_stdlog
,
1647 "LLR: Short circuiting for status 0x%x\n",
1650 if (target_can_async_p ())
1653 /* Tell the event loop we have something to process. */
1660 iterate_over_lwps (ptid
, linux_nat_resume_callback
, lp
);
1662 if (debug_linux_nat
)
1663 fprintf_unfiltered (gdb_stdlog
,
1664 "LLR: %s %s, %s (resume event thread)\n",
1665 step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1666 target_pid_to_str (lp
->ptid
),
1667 (signo
!= GDB_SIGNAL_0
1668 ? strsignal (gdb_signal_to_host (signo
)) : "0"));
1670 linux_resume_one_lwp (lp
, step
, signo
);
1672 if (target_can_async_p ())
1676 /* Send a signal to an LWP. */
1679 kill_lwp (int lwpid
, int signo
)
1684 ret
= syscall (__NR_tkill
, lwpid
, signo
);
1685 if (errno
== ENOSYS
)
1687 /* If tkill fails, then we are not using nptl threads, a
1688 configuration we no longer support. */
1689 perror_with_name (("tkill"));
1694 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1695 event, check if the core is interested in it: if not, ignore the
1696 event, and keep waiting; otherwise, we need to toggle the LWP's
1697 syscall entry/exit status, since the ptrace event itself doesn't
1698 indicate it, and report the trap to higher layers. */
1701 linux_handle_syscall_trap (struct lwp_info
*lp
, int stopping
)
1703 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1704 struct gdbarch
*gdbarch
= target_thread_architecture (lp
->ptid
);
1705 int syscall_number
= (int) gdbarch_get_syscall_number (gdbarch
, lp
->ptid
);
1709 /* If we're stopping threads, there's a SIGSTOP pending, which
1710 makes it so that the LWP reports an immediate syscall return,
1711 followed by the SIGSTOP. Skip seeing that "return" using
1712 PTRACE_CONT directly, and let stop_wait_callback collect the
1713 SIGSTOP. Later when the thread is resumed, a new syscall
1714 entry event. If we didn't do this (and returned 0), we'd
1715 leave a syscall entry pending, and our caller, by using
1716 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1717 itself. Later, when the user re-resumes this LWP, we'd see
1718 another syscall entry event and we'd mistake it for a return.
1720 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1721 (leaving immediately with LWP->signalled set, without issuing
1722 a PTRACE_CONT), it would still be problematic to leave this
1723 syscall enter pending, as later when the thread is resumed,
1724 it would then see the same syscall exit mentioned above,
1725 followed by the delayed SIGSTOP, while the syscall didn't
1726 actually get to execute. It seems it would be even more
1727 confusing to the user. */
1729 if (debug_linux_nat
)
1730 fprintf_unfiltered (gdb_stdlog
,
1731 "LHST: ignoring syscall %d "
1732 "for LWP %ld (stopping threads), "
1733 "resuming with PTRACE_CONT for SIGSTOP\n",
1735 ptid_get_lwp (lp
->ptid
));
1737 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1738 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
1743 /* Always update the entry/return state, even if this particular
1744 syscall isn't interesting to the core now. In async mode,
1745 the user could install a new catchpoint for this syscall
1746 between syscall enter/return, and we'll need to know to
1747 report a syscall return if that happens. */
1748 lp
->syscall_state
= (lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1749 ? TARGET_WAITKIND_SYSCALL_RETURN
1750 : TARGET_WAITKIND_SYSCALL_ENTRY
);
1752 if (catch_syscall_enabled ())
1754 if (catching_syscall_number (syscall_number
))
1756 /* Alright, an event to report. */
1757 ourstatus
->kind
= lp
->syscall_state
;
1758 ourstatus
->value
.syscall_number
= syscall_number
;
1760 if (debug_linux_nat
)
1761 fprintf_unfiltered (gdb_stdlog
,
1762 "LHST: stopping for %s of syscall %d"
1765 == TARGET_WAITKIND_SYSCALL_ENTRY
1766 ? "entry" : "return",
1768 ptid_get_lwp (lp
->ptid
));
1772 if (debug_linux_nat
)
1773 fprintf_unfiltered (gdb_stdlog
,
1774 "LHST: ignoring %s of syscall %d "
1776 lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1777 ? "entry" : "return",
1779 ptid_get_lwp (lp
->ptid
));
1783 /* If we had been syscall tracing, and hence used PT_SYSCALL
1784 before on this LWP, it could happen that the user removes all
1785 syscall catchpoints before we get to process this event.
1786 There are two noteworthy issues here:
1788 - When stopped at a syscall entry event, resuming with
1789 PT_STEP still resumes executing the syscall and reports a
1792 - Only PT_SYSCALL catches syscall enters. If we last
1793 single-stepped this thread, then this event can't be a
1794 syscall enter. If we last single-stepped this thread, this
1795 has to be a syscall exit.
1797 The points above mean that the next resume, be it PT_STEP or
1798 PT_CONTINUE, can not trigger a syscall trace event. */
1799 if (debug_linux_nat
)
1800 fprintf_unfiltered (gdb_stdlog
,
1801 "LHST: caught syscall event "
1802 "with no syscall catchpoints."
1803 " %d for LWP %ld, ignoring\n",
1805 ptid_get_lwp (lp
->ptid
));
1806 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1809 /* The core isn't interested in this event. For efficiency, avoid
1810 stopping all threads only to have the core resume them all again.
1811 Since we're not stopping threads, if we're still syscall tracing
1812 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1813 subsequent syscall. Simply resume using the inf-ptrace layer,
1814 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1816 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
1820 /* Handle a GNU/Linux extended wait response. If we see a clone
1821 event, we need to add the new LWP to our list (and not report the
1822 trap to higher layers). This function returns non-zero if the
1823 event should be ignored and we should wait again. If STOPPING is
1824 true, the new LWP remains stopped, otherwise it is continued. */
1827 linux_handle_extended_wait (struct lwp_info
*lp
, int status
)
1829 int pid
= ptid_get_lwp (lp
->ptid
);
1830 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1831 int event
= linux_ptrace_get_extended_event (status
);
1833 /* All extended events we currently use are mid-syscall. Only
1834 PTRACE_EVENT_STOP is delivered more like a signal-stop, but
1835 you have to be using PTRACE_SEIZE to get that. */
1836 lp
->syscall_state
= TARGET_WAITKIND_SYSCALL_ENTRY
;
1838 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
1839 || event
== PTRACE_EVENT_CLONE
)
1841 unsigned long new_pid
;
1844 ptrace (PTRACE_GETEVENTMSG
, pid
, 0, &new_pid
);
1846 /* If we haven't already seen the new PID stop, wait for it now. */
1847 if (! pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
1849 /* The new child has a pending SIGSTOP. We can't affect it until it
1850 hits the SIGSTOP, but we're already attached. */
1851 ret
= my_waitpid (new_pid
, &status
, __WALL
);
1853 perror_with_name (_("waiting for new child"));
1854 else if (ret
!= new_pid
)
1855 internal_error (__FILE__
, __LINE__
,
1856 _("wait returned unexpected PID %d"), ret
);
1857 else if (!WIFSTOPPED (status
))
1858 internal_error (__FILE__
, __LINE__
,
1859 _("wait returned unexpected status 0x%x"), status
);
1862 ourstatus
->value
.related_pid
= ptid_build (new_pid
, new_pid
, 0);
1864 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
)
1866 /* The arch-specific native code may need to know about new
1867 forks even if those end up never mapped to an
1869 if (linux_nat_new_fork
!= NULL
)
1870 linux_nat_new_fork (lp
, new_pid
);
1873 if (event
== PTRACE_EVENT_FORK
1874 && linux_fork_checkpointing_p (ptid_get_pid (lp
->ptid
)))
1876 /* Handle checkpointing by linux-fork.c here as a special
1877 case. We don't want the follow-fork-mode or 'catch fork'
1878 to interfere with this. */
1880 /* This won't actually modify the breakpoint list, but will
1881 physically remove the breakpoints from the child. */
1882 detach_breakpoints (ptid_build (new_pid
, new_pid
, 0));
1884 /* Retain child fork in ptrace (stopped) state. */
1885 if (!find_fork_pid (new_pid
))
1888 /* Report as spurious, so that infrun doesn't want to follow
1889 this fork. We're actually doing an infcall in
1891 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
1893 /* Report the stop to the core. */
1897 if (event
== PTRACE_EVENT_FORK
)
1898 ourstatus
->kind
= TARGET_WAITKIND_FORKED
;
1899 else if (event
== PTRACE_EVENT_VFORK
)
1900 ourstatus
->kind
= TARGET_WAITKIND_VFORKED
;
1901 else if (event
== PTRACE_EVENT_CLONE
)
1903 struct lwp_info
*new_lp
;
1905 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
1907 if (debug_linux_nat
)
1908 fprintf_unfiltered (gdb_stdlog
,
1909 "LHEW: Got clone event "
1910 "from LWP %d, new child is LWP %ld\n",
1913 new_lp
= add_lwp (ptid_build (ptid_get_pid (lp
->ptid
), new_pid
, 0));
1914 new_lp
->stopped
= 1;
1915 new_lp
->resumed
= 1;
1917 /* If the thread_db layer is active, let it record the user
1918 level thread id and status, and add the thread to GDB's
1920 if (!thread_db_notice_clone (lp
->ptid
, new_lp
->ptid
))
1922 /* The process is not using thread_db. Add the LWP to
1924 target_post_attach (ptid_get_lwp (new_lp
->ptid
));
1925 add_thread (new_lp
->ptid
);
1928 /* Even if we're stopping the thread for some reason
1929 internal to this module, from the perspective of infrun
1930 and the user/frontend, this new thread is running until
1931 it next reports a stop. */
1932 set_running (new_lp
->ptid
, 1);
1933 set_executing (new_lp
->ptid
, 1);
1935 if (WSTOPSIG (status
) != SIGSTOP
)
1937 /* This can happen if someone starts sending signals to
1938 the new thread before it gets a chance to run, which
1939 have a lower number than SIGSTOP (e.g. SIGUSR1).
1940 This is an unlikely case, and harder to handle for
1941 fork / vfork than for clone, so we do not try - but
1942 we handle it for clone events here. */
1944 new_lp
->signalled
= 1;
1946 /* We created NEW_LP so it cannot yet contain STATUS. */
1947 gdb_assert (new_lp
->status
== 0);
1949 /* Save the wait status to report later. */
1950 if (debug_linux_nat
)
1951 fprintf_unfiltered (gdb_stdlog
,
1952 "LHEW: waitpid of new LWP %ld, "
1953 "saving status %s\n",
1954 (long) ptid_get_lwp (new_lp
->ptid
),
1955 status_to_str (status
));
1956 new_lp
->status
= status
;
1958 else if (report_thread_events
)
1960 new_lp
->waitstatus
.kind
= TARGET_WAITKIND_THREAD_CREATED
;
1961 new_lp
->status
= status
;
1970 if (event
== PTRACE_EVENT_EXEC
)
1972 if (debug_linux_nat
)
1973 fprintf_unfiltered (gdb_stdlog
,
1974 "LHEW: Got exec event from LWP %ld\n",
1975 ptid_get_lwp (lp
->ptid
));
1977 ourstatus
->kind
= TARGET_WAITKIND_EXECD
;
1978 ourstatus
->value
.execd_pathname
1979 = xstrdup (linux_child_pid_to_exec_file (NULL
, pid
));
1981 /* The thread that execed must have been resumed, but, when a
1982 thread execs, it changes its tid to the tgid, and the old
1983 tgid thread might have not been resumed. */
1988 if (event
== PTRACE_EVENT_VFORK_DONE
)
1990 if (current_inferior ()->waiting_for_vfork_done
)
1992 if (debug_linux_nat
)
1993 fprintf_unfiltered (gdb_stdlog
,
1994 "LHEW: Got expected PTRACE_EVENT_"
1995 "VFORK_DONE from LWP %ld: stopping\n",
1996 ptid_get_lwp (lp
->ptid
));
1998 ourstatus
->kind
= TARGET_WAITKIND_VFORK_DONE
;
2002 if (debug_linux_nat
)
2003 fprintf_unfiltered (gdb_stdlog
,
2004 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2005 "from LWP %ld: ignoring\n",
2006 ptid_get_lwp (lp
->ptid
));
2010 internal_error (__FILE__
, __LINE__
,
2011 _("unknown ptrace event %d"), event
);
2014 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2018 wait_lwp (struct lwp_info
*lp
)
2022 int thread_dead
= 0;
2025 gdb_assert (!lp
->stopped
);
2026 gdb_assert (lp
->status
== 0);
2028 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2029 block_child_signals (&prev_mask
);
2033 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), &status
, __WALL
| WNOHANG
);
2034 if (pid
== -1 && errno
== ECHILD
)
2036 /* The thread has previously exited. We need to delete it
2037 now because if this was a non-leader thread execing, we
2038 won't get an exit event. See comments on exec events at
2039 the top of the file. */
2041 if (debug_linux_nat
)
2042 fprintf_unfiltered (gdb_stdlog
, "WL: %s vanished.\n",
2043 target_pid_to_str (lp
->ptid
));
2048 /* Bugs 10970, 12702.
2049 Thread group leader may have exited in which case we'll lock up in
2050 waitpid if there are other threads, even if they are all zombies too.
2051 Basically, we're not supposed to use waitpid this way.
2052 tkill(pid,0) cannot be used here as it gets ESRCH for both
2053 for zombie and running processes.
2055 As a workaround, check if we're waiting for the thread group leader and
2056 if it's a zombie, and avoid calling waitpid if it is.
2058 This is racy, what if the tgl becomes a zombie right after we check?
2059 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2060 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2062 if (ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
)
2063 && linux_proc_pid_is_zombie (ptid_get_lwp (lp
->ptid
)))
2066 if (debug_linux_nat
)
2067 fprintf_unfiltered (gdb_stdlog
,
2068 "WL: Thread group leader %s vanished.\n",
2069 target_pid_to_str (lp
->ptid
));
2073 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2074 get invoked despite our caller had them intentionally blocked by
2075 block_child_signals. This is sensitive only to the loop of
2076 linux_nat_wait_1 and there if we get called my_waitpid gets called
2077 again before it gets to sigsuspend so we can safely let the handlers
2078 get executed here. */
2080 if (debug_linux_nat
)
2081 fprintf_unfiltered (gdb_stdlog
, "WL: about to sigsuspend\n");
2082 sigsuspend (&suspend_mask
);
2085 restore_child_signals_mask (&prev_mask
);
2089 gdb_assert (pid
== ptid_get_lwp (lp
->ptid
));
2091 if (debug_linux_nat
)
2093 fprintf_unfiltered (gdb_stdlog
,
2094 "WL: waitpid %s received %s\n",
2095 target_pid_to_str (lp
->ptid
),
2096 status_to_str (status
));
2099 /* Check if the thread has exited. */
2100 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2102 if (report_thread_events
2103 || ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
))
2105 if (debug_linux_nat
)
2106 fprintf_unfiltered (gdb_stdlog
, "WL: LWP %d exited.\n",
2107 ptid_get_pid (lp
->ptid
));
2109 /* If this is the leader exiting, it means the whole
2110 process is gone. Store the status to report to the
2111 core. Store it in lp->waitstatus, because lp->status
2112 would be ambiguous (W_EXITCODE(0,0) == 0). */
2113 store_waitstatus (&lp
->waitstatus
, status
);
2118 if (debug_linux_nat
)
2119 fprintf_unfiltered (gdb_stdlog
, "WL: %s exited.\n",
2120 target_pid_to_str (lp
->ptid
));
2130 gdb_assert (WIFSTOPPED (status
));
2133 if (lp
->must_set_ptrace_flags
)
2135 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
2136 int options
= linux_nat_ptrace_options (inf
->attach_flag
);
2138 linux_enable_event_reporting (ptid_get_lwp (lp
->ptid
), options
);
2139 lp
->must_set_ptrace_flags
= 0;
2142 /* Handle GNU/Linux's syscall SIGTRAPs. */
2143 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2145 /* No longer need the sysgood bit. The ptrace event ends up
2146 recorded in lp->waitstatus if we care for it. We can carry
2147 on handling the event like a regular SIGTRAP from here
2149 status
= W_STOPCODE (SIGTRAP
);
2150 if (linux_handle_syscall_trap (lp
, 1))
2151 return wait_lwp (lp
);
2155 /* Almost all other ptrace-stops are known to be outside of system
2156 calls, with further exceptions in linux_handle_extended_wait. */
2157 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2160 /* Handle GNU/Linux's extended waitstatus for trace events. */
2161 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
2162 && linux_is_extended_waitstatus (status
))
2164 if (debug_linux_nat
)
2165 fprintf_unfiltered (gdb_stdlog
,
2166 "WL: Handling extended status 0x%06x\n",
2168 linux_handle_extended_wait (lp
, status
);
2175 /* Send a SIGSTOP to LP. */
2178 stop_callback (struct lwp_info
*lp
, void *data
)
2180 if (!lp
->stopped
&& !lp
->signalled
)
2184 if (debug_linux_nat
)
2186 fprintf_unfiltered (gdb_stdlog
,
2187 "SC: kill %s **<SIGSTOP>**\n",
2188 target_pid_to_str (lp
->ptid
));
2191 ret
= kill_lwp (ptid_get_lwp (lp
->ptid
), SIGSTOP
);
2192 if (debug_linux_nat
)
2194 fprintf_unfiltered (gdb_stdlog
,
2195 "SC: lwp kill %d %s\n",
2197 errno
? safe_strerror (errno
) : "ERRNO-OK");
2201 gdb_assert (lp
->status
== 0);
2207 /* Request a stop on LWP. */
2210 linux_stop_lwp (struct lwp_info
*lwp
)
2212 stop_callback (lwp
, NULL
);
2215 /* See linux-nat.h */
2218 linux_stop_and_wait_all_lwps (void)
2220 /* Stop all LWP's ... */
2221 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
2223 /* ... and wait until all of them have reported back that
2224 they're no longer running. */
2225 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
2228 /* See linux-nat.h */
2231 linux_unstop_all_lwps (void)
2233 iterate_over_lwps (minus_one_ptid
,
2234 resume_stopped_resumed_lwps
, &minus_one_ptid
);
2237 /* Return non-zero if LWP PID has a pending SIGINT. */
2240 linux_nat_has_pending_sigint (int pid
)
2242 sigset_t pending
, blocked
, ignored
;
2244 linux_proc_pending_signals (pid
, &pending
, &blocked
, &ignored
);
2246 if (sigismember (&pending
, SIGINT
)
2247 && !sigismember (&ignored
, SIGINT
))
2253 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2256 set_ignore_sigint (struct lwp_info
*lp
, void *data
)
2258 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2259 flag to consume the next one. */
2260 if (lp
->stopped
&& lp
->status
!= 0 && WIFSTOPPED (lp
->status
)
2261 && WSTOPSIG (lp
->status
) == SIGINT
)
2264 lp
->ignore_sigint
= 1;
2269 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2270 This function is called after we know the LWP has stopped; if the LWP
2271 stopped before the expected SIGINT was delivered, then it will never have
2272 arrived. Also, if the signal was delivered to a shared queue and consumed
2273 by a different thread, it will never be delivered to this LWP. */
2276 maybe_clear_ignore_sigint (struct lwp_info
*lp
)
2278 if (!lp
->ignore_sigint
)
2281 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp
->ptid
)))
2283 if (debug_linux_nat
)
2284 fprintf_unfiltered (gdb_stdlog
,
2285 "MCIS: Clearing bogus flag for %s\n",
2286 target_pid_to_str (lp
->ptid
));
2287 lp
->ignore_sigint
= 0;
2291 /* Fetch the possible triggered data watchpoint info and store it in
2294 On some archs, like x86, that use debug registers to set
2295 watchpoints, it's possible that the way to know which watched
2296 address trapped, is to check the register that is used to select
2297 which address to watch. Problem is, between setting the watchpoint
2298 and reading back which data address trapped, the user may change
2299 the set of watchpoints, and, as a consequence, GDB changes the
2300 debug registers in the inferior. To avoid reading back a stale
2301 stopped-data-address when that happens, we cache in LP the fact
2302 that a watchpoint trapped, and the corresponding data address, as
2303 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2304 registers meanwhile, we have the cached data we can rely on. */
2307 check_stopped_by_watchpoint (struct lwp_info
*lp
)
2309 struct cleanup
*old_chain
;
2311 if (linux_ops
->to_stopped_by_watchpoint
== NULL
)
2314 old_chain
= save_inferior_ptid ();
2315 inferior_ptid
= lp
->ptid
;
2317 if (linux_ops
->to_stopped_by_watchpoint (linux_ops
))
2319 lp
->stop_reason
= TARGET_STOPPED_BY_WATCHPOINT
;
2321 if (linux_ops
->to_stopped_data_address
!= NULL
)
2322 lp
->stopped_data_address_p
=
2323 linux_ops
->to_stopped_data_address (¤t_target
,
2324 &lp
->stopped_data_address
);
2326 lp
->stopped_data_address_p
= 0;
2329 do_cleanups (old_chain
);
2331 return lp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
2334 /* Returns true if the LWP had stopped for a watchpoint. */
2337 linux_nat_stopped_by_watchpoint (struct target_ops
*ops
)
2339 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2341 gdb_assert (lp
!= NULL
);
2343 return lp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
2347 linux_nat_stopped_data_address (struct target_ops
*ops
, CORE_ADDR
*addr_p
)
2349 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2351 gdb_assert (lp
!= NULL
);
2353 *addr_p
= lp
->stopped_data_address
;
2355 return lp
->stopped_data_address_p
;
2358 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2361 sigtrap_is_event (int status
)
2363 return WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
;
2366 /* Set alternative SIGTRAP-like events recognizer. If
2367 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2371 linux_nat_set_status_is_event (struct target_ops
*t
,
2372 int (*status_is_event
) (int status
))
2374 linux_nat_status_is_event
= status_is_event
;
2377 /* Wait until LP is stopped. */
2380 stop_wait_callback (struct lwp_info
*lp
, void *data
)
2382 struct inferior
*inf
= find_inferior_ptid (lp
->ptid
);
2384 /* If this is a vfork parent, bail out, it is not going to report
2385 any SIGSTOP until the vfork is done with. */
2386 if (inf
->vfork_child
!= NULL
)
2393 status
= wait_lwp (lp
);
2397 if (lp
->ignore_sigint
&& WIFSTOPPED (status
)
2398 && WSTOPSIG (status
) == SIGINT
)
2400 lp
->ignore_sigint
= 0;
2403 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
2405 if (debug_linux_nat
)
2406 fprintf_unfiltered (gdb_stdlog
,
2407 "PTRACE_CONT %s, 0, 0 (%s) "
2408 "(discarding SIGINT)\n",
2409 target_pid_to_str (lp
->ptid
),
2410 errno
? safe_strerror (errno
) : "OK");
2412 return stop_wait_callback (lp
, NULL
);
2415 maybe_clear_ignore_sigint (lp
);
2417 if (WSTOPSIG (status
) != SIGSTOP
)
2419 /* The thread was stopped with a signal other than SIGSTOP. */
2421 if (debug_linux_nat
)
2422 fprintf_unfiltered (gdb_stdlog
,
2423 "SWC: Pending event %s in %s\n",
2424 status_to_str ((int) status
),
2425 target_pid_to_str (lp
->ptid
));
2427 /* Save the sigtrap event. */
2428 lp
->status
= status
;
2429 gdb_assert (lp
->signalled
);
2430 save_stop_reason (lp
);
2434 /* We caught the SIGSTOP that we intended to catch, so
2435 there's no SIGSTOP pending. */
2437 if (debug_linux_nat
)
2438 fprintf_unfiltered (gdb_stdlog
,
2439 "SWC: Expected SIGSTOP caught for %s.\n",
2440 target_pid_to_str (lp
->ptid
));
2442 /* Reset SIGNALLED only after the stop_wait_callback call
2443 above as it does gdb_assert on SIGNALLED. */
2451 /* Return non-zero if LP has a wait status pending. Discard the
2452 pending event and resume the LWP if the event that originally
2453 caused the stop became uninteresting. */
2456 status_callback (struct lwp_info
*lp
, void *data
)
2458 /* Only report a pending wait status if we pretend that this has
2459 indeed been resumed. */
2463 if (!lwp_status_pending_p (lp
))
2466 if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
2467 || lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
)
2469 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
2473 pc
= regcache_read_pc (regcache
);
2475 if (pc
!= lp
->stop_pc
)
2477 if (debug_linux_nat
)
2478 fprintf_unfiltered (gdb_stdlog
,
2479 "SC: PC of %s changed. was=%s, now=%s\n",
2480 target_pid_to_str (lp
->ptid
),
2481 paddress (target_gdbarch (), lp
->stop_pc
),
2482 paddress (target_gdbarch (), pc
));
2486 #if !USE_SIGTRAP_SIGINFO
2487 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
2489 if (debug_linux_nat
)
2490 fprintf_unfiltered (gdb_stdlog
,
2491 "SC: previous breakpoint of %s, at %s gone\n",
2492 target_pid_to_str (lp
->ptid
),
2493 paddress (target_gdbarch (), lp
->stop_pc
));
2501 if (debug_linux_nat
)
2502 fprintf_unfiltered (gdb_stdlog
,
2503 "SC: pending event of %s cancelled.\n",
2504 target_pid_to_str (lp
->ptid
));
2507 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
2515 /* Count the LWP's that have had events. */
2518 count_events_callback (struct lwp_info
*lp
, void *data
)
2520 int *count
= (int *) data
;
2522 gdb_assert (count
!= NULL
);
2524 /* Select only resumed LWPs that have an event pending. */
2525 if (lp
->resumed
&& lwp_status_pending_p (lp
))
2531 /* Select the LWP (if any) that is currently being single-stepped. */
2534 select_singlestep_lwp_callback (struct lwp_info
*lp
, void *data
)
2536 if (lp
->last_resume_kind
== resume_step
2543 /* Returns true if LP has a status pending. */
2546 lwp_status_pending_p (struct lwp_info
*lp
)
2548 /* We check for lp->waitstatus in addition to lp->status, because we
2549 can have pending process exits recorded in lp->status and
2550 W_EXITCODE(0,0) happens to be 0. */
2551 return lp
->status
!= 0 || lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
;
2554 /* Select the Nth LWP that has had an event. */
2557 select_event_lwp_callback (struct lwp_info
*lp
, void *data
)
2559 int *selector
= (int *) data
;
2561 gdb_assert (selector
!= NULL
);
2563 /* Select only resumed LWPs that have an event pending. */
2564 if (lp
->resumed
&& lwp_status_pending_p (lp
))
2565 if ((*selector
)-- == 0)
2571 /* Called when the LWP stopped for a signal/trap. If it stopped for a
2572 trap check what caused it (breakpoint, watchpoint, trace, etc.),
2573 and save the result in the LWP's stop_reason field. If it stopped
2574 for a breakpoint, decrement the PC if necessary on the lwp's
2578 save_stop_reason (struct lwp_info
*lp
)
2580 struct regcache
*regcache
;
2581 struct gdbarch
*gdbarch
;
2584 #if USE_SIGTRAP_SIGINFO
2588 gdb_assert (lp
->stop_reason
== TARGET_STOPPED_BY_NO_REASON
);
2589 gdb_assert (lp
->status
!= 0);
2591 if (!linux_nat_status_is_event (lp
->status
))
2594 regcache
= get_thread_regcache (lp
->ptid
);
2595 gdbarch
= get_regcache_arch (regcache
);
2597 pc
= regcache_read_pc (regcache
);
2598 sw_bp_pc
= pc
- gdbarch_decr_pc_after_break (gdbarch
);
2600 #if USE_SIGTRAP_SIGINFO
2601 if (linux_nat_get_siginfo (lp
->ptid
, &siginfo
))
2603 if (siginfo
.si_signo
== SIGTRAP
)
2605 if (GDB_ARCH_IS_TRAP_BRKPT (siginfo
.si_code
)
2606 && GDB_ARCH_IS_TRAP_HWBKPT (siginfo
.si_code
))
2608 /* The si_code is ambiguous on this arch -- check debug
2610 if (!check_stopped_by_watchpoint (lp
))
2611 lp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
2613 else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo
.si_code
))
2615 /* If we determine the LWP stopped for a SW breakpoint,
2616 trust it. Particularly don't check watchpoint
2617 registers, because at least on s390, we'd find
2618 stopped-by-watchpoint as long as there's a watchpoint
2620 lp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
2622 else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo
.si_code
))
2624 /* This can indicate either a hardware breakpoint or
2625 hardware watchpoint. Check debug registers. */
2626 if (!check_stopped_by_watchpoint (lp
))
2627 lp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
2629 else if (siginfo
.si_code
== TRAP_TRACE
)
2631 if (debug_linux_nat
)
2632 fprintf_unfiltered (gdb_stdlog
,
2633 "CSBB: %s stopped by trace\n",
2634 target_pid_to_str (lp
->ptid
));
2636 /* We may have single stepped an instruction that
2637 triggered a watchpoint. In that case, on some
2638 architectures (such as x86), instead of TRAP_HWBKPT,
2639 si_code indicates TRAP_TRACE, and we need to check
2640 the debug registers separately. */
2641 check_stopped_by_watchpoint (lp
);
2646 if ((!lp
->step
|| lp
->stop_pc
== sw_bp_pc
)
2647 && software_breakpoint_inserted_here_p (get_regcache_aspace (regcache
),
2650 /* The LWP was either continued, or stepped a software
2651 breakpoint instruction. */
2652 lp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
2655 if (hardware_breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
2656 lp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
2658 if (lp
->stop_reason
== TARGET_STOPPED_BY_NO_REASON
)
2659 check_stopped_by_watchpoint (lp
);
2662 if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
)
2664 if (debug_linux_nat
)
2665 fprintf_unfiltered (gdb_stdlog
,
2666 "CSBB: %s stopped by software breakpoint\n",
2667 target_pid_to_str (lp
->ptid
));
2669 /* Back up the PC if necessary. */
2671 regcache_write_pc (regcache
, sw_bp_pc
);
2673 /* Update this so we record the correct stop PC below. */
2676 else if (lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
)
2678 if (debug_linux_nat
)
2679 fprintf_unfiltered (gdb_stdlog
,
2680 "CSBB: %s stopped by hardware breakpoint\n",
2681 target_pid_to_str (lp
->ptid
));
2683 else if (lp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
)
2685 if (debug_linux_nat
)
2686 fprintf_unfiltered (gdb_stdlog
,
2687 "CSBB: %s stopped by hardware watchpoint\n",
2688 target_pid_to_str (lp
->ptid
));
2695 /* Returns true if the LWP had stopped for a software breakpoint. */
2698 linux_nat_stopped_by_sw_breakpoint (struct target_ops
*ops
)
2700 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2702 gdb_assert (lp
!= NULL
);
2704 return lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
;
2707 /* Implement the supports_stopped_by_sw_breakpoint method. */
2710 linux_nat_supports_stopped_by_sw_breakpoint (struct target_ops
*ops
)
2712 return USE_SIGTRAP_SIGINFO
;
2715 /* Returns true if the LWP had stopped for a hardware
2716 breakpoint/watchpoint. */
2719 linux_nat_stopped_by_hw_breakpoint (struct target_ops
*ops
)
2721 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2723 gdb_assert (lp
!= NULL
);
2725 return lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
;
2728 /* Implement the supports_stopped_by_hw_breakpoint method. */
2731 linux_nat_supports_stopped_by_hw_breakpoint (struct target_ops
*ops
)
2733 return USE_SIGTRAP_SIGINFO
;
2736 /* Select one LWP out of those that have events pending. */
2739 select_event_lwp (ptid_t filter
, struct lwp_info
**orig_lp
, int *status
)
2742 int random_selector
;
2743 struct lwp_info
*event_lp
= NULL
;
2745 /* Record the wait status for the original LWP. */
2746 (*orig_lp
)->status
= *status
;
2748 /* In all-stop, give preference to the LWP that is being
2749 single-stepped. There will be at most one, and it will be the
2750 LWP that the core is most interested in. If we didn't do this,
2751 then we'd have to handle pending step SIGTRAPs somehow in case
2752 the core later continues the previously-stepped thread, as
2753 otherwise we'd report the pending SIGTRAP then, and the core, not
2754 having stepped the thread, wouldn't understand what the trap was
2755 for, and therefore would report it to the user as a random
2757 if (!target_is_non_stop_p ())
2759 event_lp
= iterate_over_lwps (filter
,
2760 select_singlestep_lwp_callback
, NULL
);
2761 if (event_lp
!= NULL
)
2763 if (debug_linux_nat
)
2764 fprintf_unfiltered (gdb_stdlog
,
2765 "SEL: Select single-step %s\n",
2766 target_pid_to_str (event_lp
->ptid
));
2770 if (event_lp
== NULL
)
2772 /* Pick one at random, out of those which have had events. */
2774 /* First see how many events we have. */
2775 iterate_over_lwps (filter
, count_events_callback
, &num_events
);
2776 gdb_assert (num_events
> 0);
2778 /* Now randomly pick a LWP out of those that have had
2780 random_selector
= (int)
2781 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
2783 if (debug_linux_nat
&& num_events
> 1)
2784 fprintf_unfiltered (gdb_stdlog
,
2785 "SEL: Found %d events, selecting #%d\n",
2786 num_events
, random_selector
);
2788 event_lp
= iterate_over_lwps (filter
,
2789 select_event_lwp_callback
,
2793 if (event_lp
!= NULL
)
2795 /* Switch the event LWP. */
2796 *orig_lp
= event_lp
;
2797 *status
= event_lp
->status
;
2800 /* Flush the wait status for the event LWP. */
2801 (*orig_lp
)->status
= 0;
2804 /* Return non-zero if LP has been resumed. */
2807 resumed_callback (struct lwp_info
*lp
, void *data
)
2812 /* Check if we should go on and pass this event to common code.
2813 Return the affected lwp if we are, or NULL otherwise. */
2815 static struct lwp_info
*
2816 linux_nat_filter_event (int lwpid
, int status
)
2818 struct lwp_info
*lp
;
2819 int event
= linux_ptrace_get_extended_event (status
);
2821 lp
= find_lwp_pid (pid_to_ptid (lwpid
));
2823 /* Check for stop events reported by a process we didn't already
2824 know about - anything not already in our LWP list.
2826 If we're expecting to receive stopped processes after
2827 fork, vfork, and clone events, then we'll just add the
2828 new one to our list and go back to waiting for the event
2829 to be reported - the stopped process might be returned
2830 from waitpid before or after the event is.
2832 But note the case of a non-leader thread exec'ing after the
2833 leader having exited, and gone from our lists. The non-leader
2834 thread changes its tid to the tgid. */
2836 if (WIFSTOPPED (status
) && lp
== NULL
2837 && (WSTOPSIG (status
) == SIGTRAP
&& event
== PTRACE_EVENT_EXEC
))
2839 /* A multi-thread exec after we had seen the leader exiting. */
2840 if (debug_linux_nat
)
2841 fprintf_unfiltered (gdb_stdlog
,
2842 "LLW: Re-adding thread group leader LWP %d.\n",
2845 lp
= add_lwp (ptid_build (lwpid
, lwpid
, 0));
2848 add_thread (lp
->ptid
);
2851 if (WIFSTOPPED (status
) && !lp
)
2853 if (debug_linux_nat
)
2854 fprintf_unfiltered (gdb_stdlog
,
2855 "LHEW: saving LWP %ld status %s in stopped_pids list\n",
2856 (long) lwpid
, status_to_str (status
));
2857 add_to_pid_list (&stopped_pids
, lwpid
, status
);
2861 /* Make sure we don't report an event for the exit of an LWP not in
2862 our list, i.e. not part of the current process. This can happen
2863 if we detach from a program we originally forked and then it
2865 if (!WIFSTOPPED (status
) && !lp
)
2868 /* This LWP is stopped now. (And if dead, this prevents it from
2869 ever being continued.) */
2872 if (WIFSTOPPED (status
) && lp
->must_set_ptrace_flags
)
2874 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
2875 int options
= linux_nat_ptrace_options (inf
->attach_flag
);
2877 linux_enable_event_reporting (ptid_get_lwp (lp
->ptid
), options
);
2878 lp
->must_set_ptrace_flags
= 0;
2881 /* Handle GNU/Linux's syscall SIGTRAPs. */
2882 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2884 /* No longer need the sysgood bit. The ptrace event ends up
2885 recorded in lp->waitstatus if we care for it. We can carry
2886 on handling the event like a regular SIGTRAP from here
2888 status
= W_STOPCODE (SIGTRAP
);
2889 if (linux_handle_syscall_trap (lp
, 0))
2894 /* Almost all other ptrace-stops are known to be outside of system
2895 calls, with further exceptions in linux_handle_extended_wait. */
2896 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2899 /* Handle GNU/Linux's extended waitstatus for trace events. */
2900 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
2901 && linux_is_extended_waitstatus (status
))
2903 if (debug_linux_nat
)
2904 fprintf_unfiltered (gdb_stdlog
,
2905 "LLW: Handling extended status 0x%06x\n",
2907 if (linux_handle_extended_wait (lp
, status
))
2911 /* Check if the thread has exited. */
2912 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2914 if (!report_thread_events
2915 && num_lwps (ptid_get_pid (lp
->ptid
)) > 1)
2917 if (debug_linux_nat
)
2918 fprintf_unfiltered (gdb_stdlog
,
2919 "LLW: %s exited.\n",
2920 target_pid_to_str (lp
->ptid
));
2922 /* If there is at least one more LWP, then the exit signal
2923 was not the end of the debugged application and should be
2929 /* Note that even if the leader was ptrace-stopped, it can still
2930 exit, if e.g., some other thread brings down the whole
2931 process (calls `exit'). So don't assert that the lwp is
2933 if (debug_linux_nat
)
2934 fprintf_unfiltered (gdb_stdlog
,
2935 "LWP %ld exited (resumed=%d)\n",
2936 ptid_get_lwp (lp
->ptid
), lp
->resumed
);
2938 /* Dead LWP's aren't expected to reported a pending sigstop. */
2941 /* Store the pending event in the waitstatus, because
2942 W_EXITCODE(0,0) == 0. */
2943 store_waitstatus (&lp
->waitstatus
, status
);
2947 /* Make sure we don't report a SIGSTOP that we sent ourselves in
2948 an attempt to stop an LWP. */
2950 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGSTOP
)
2954 if (lp
->last_resume_kind
== resume_stop
)
2956 if (debug_linux_nat
)
2957 fprintf_unfiltered (gdb_stdlog
,
2958 "LLW: resume_stop SIGSTOP caught for %s.\n",
2959 target_pid_to_str (lp
->ptid
));
2963 /* This is a delayed SIGSTOP. Filter out the event. */
2965 if (debug_linux_nat
)
2966 fprintf_unfiltered (gdb_stdlog
,
2967 "LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
2969 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2970 target_pid_to_str (lp
->ptid
));
2972 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
2973 gdb_assert (lp
->resumed
);
2978 /* Make sure we don't report a SIGINT that we have already displayed
2979 for another thread. */
2980 if (lp
->ignore_sigint
2981 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGINT
)
2983 if (debug_linux_nat
)
2984 fprintf_unfiltered (gdb_stdlog
,
2985 "LLW: Delayed SIGINT caught for %s.\n",
2986 target_pid_to_str (lp
->ptid
));
2988 /* This is a delayed SIGINT. */
2989 lp
->ignore_sigint
= 0;
2991 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
2992 if (debug_linux_nat
)
2993 fprintf_unfiltered (gdb_stdlog
,
2994 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
2996 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2997 target_pid_to_str (lp
->ptid
));
2998 gdb_assert (lp
->resumed
);
3000 /* Discard the event. */
3004 /* Don't report signals that GDB isn't interested in, such as
3005 signals that are neither printed nor stopped upon. Stopping all
3006 threads can be a bit time-consuming so if we want decent
3007 performance with heavily multi-threaded programs, especially when
3008 they're using a high frequency timer, we'd better avoid it if we
3010 if (WIFSTOPPED (status
))
3012 enum gdb_signal signo
= gdb_signal_from_host (WSTOPSIG (status
));
3014 if (!target_is_non_stop_p ())
3016 /* Only do the below in all-stop, as we currently use SIGSTOP
3017 to implement target_stop (see linux_nat_stop) in
3019 if (signo
== GDB_SIGNAL_INT
&& signal_pass_state (signo
) == 0)
3021 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3022 forwarded to the entire process group, that is, all LWPs
3023 will receive it - unless they're using CLONE_THREAD to
3024 share signals. Since we only want to report it once, we
3025 mark it as ignored for all LWPs except this one. */
3026 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp
->ptid
)),
3027 set_ignore_sigint
, NULL
);
3028 lp
->ignore_sigint
= 0;
3031 maybe_clear_ignore_sigint (lp
);
3034 /* When using hardware single-step, we need to report every signal.
3035 Otherwise, signals in pass_mask may be short-circuited
3036 except signals that might be caused by a breakpoint. */
3038 && WSTOPSIG (status
) && sigismember (&pass_mask
, WSTOPSIG (status
))
3039 && !linux_wstatus_maybe_breakpoint (status
))
3041 linux_resume_one_lwp (lp
, lp
->step
, signo
);
3042 if (debug_linux_nat
)
3043 fprintf_unfiltered (gdb_stdlog
,
3044 "LLW: %s %s, %s (preempt 'handle')\n",
3046 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3047 target_pid_to_str (lp
->ptid
),
3048 (signo
!= GDB_SIGNAL_0
3049 ? strsignal (gdb_signal_to_host (signo
))
3055 /* An interesting event. */
3057 lp
->status
= status
;
3058 save_stop_reason (lp
);
3062 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3063 their exits until all other threads in the group have exited. */
3066 check_zombie_leaders (void)
3068 struct inferior
*inf
;
3072 struct lwp_info
*leader_lp
;
3077 leader_lp
= find_lwp_pid (pid_to_ptid (inf
->pid
));
3078 if (leader_lp
!= NULL
3079 /* Check if there are other threads in the group, as we may
3080 have raced with the inferior simply exiting. */
3081 && num_lwps (inf
->pid
) > 1
3082 && linux_proc_pid_is_zombie (inf
->pid
))
3084 if (debug_linux_nat
)
3085 fprintf_unfiltered (gdb_stdlog
,
3086 "CZL: Thread group leader %d zombie "
3087 "(it exited, or another thread execd).\n",
3090 /* A leader zombie can mean one of two things:
3092 - It exited, and there's an exit status pending
3093 available, or only the leader exited (not the whole
3094 program). In the latter case, we can't waitpid the
3095 leader's exit status until all other threads are gone.
3097 - There are 3 or more threads in the group, and a thread
3098 other than the leader exec'd. See comments on exec
3099 events at the top of the file. We could try
3100 distinguishing the exit and exec cases, by waiting once
3101 more, and seeing if something comes out, but it doesn't
3102 sound useful. The previous leader _does_ go away, and
3103 we'll re-add the new one once we see the exec event
3104 (which is just the same as what would happen if the
3105 previous leader did exit voluntarily before some other
3108 if (debug_linux_nat
)
3109 fprintf_unfiltered (gdb_stdlog
,
3110 "CZL: Thread group leader %d vanished.\n",
3112 exit_lwp (leader_lp
);
3117 /* Convenience function that is called when the kernel reports an exit
3118 event. This decides whether to report the event to GDB as a
3119 process exit event, a thread exit event, or to suppress the
3123 filter_exit_event (struct lwp_info
*event_child
,
3124 struct target_waitstatus
*ourstatus
)
3126 ptid_t ptid
= event_child
->ptid
;
3128 if (num_lwps (ptid_get_pid (ptid
)) > 1)
3130 if (report_thread_events
)
3131 ourstatus
->kind
= TARGET_WAITKIND_THREAD_EXITED
;
3133 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3135 exit_lwp (event_child
);
3142 linux_nat_wait_1 (struct target_ops
*ops
,
3143 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3147 enum resume_kind last_resume_kind
;
3148 struct lwp_info
*lp
;
3151 if (debug_linux_nat
)
3152 fprintf_unfiltered (gdb_stdlog
, "LLW: enter\n");
3154 /* The first time we get here after starting a new inferior, we may
3155 not have added it to the LWP list yet - this is the earliest
3156 moment at which we know its PID. */
3157 if (ptid_is_pid (inferior_ptid
))
3159 /* Upgrade the main thread's ptid. */
3160 thread_change_ptid (inferior_ptid
,
3161 ptid_build (ptid_get_pid (inferior_ptid
),
3162 ptid_get_pid (inferior_ptid
), 0));
3164 lp
= add_initial_lwp (inferior_ptid
);
3168 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3169 block_child_signals (&prev_mask
);
3171 /* First check if there is a LWP with a wait status pending. */
3172 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3175 if (debug_linux_nat
)
3176 fprintf_unfiltered (gdb_stdlog
,
3177 "LLW: Using pending wait status %s for %s.\n",
3178 status_to_str (lp
->status
),
3179 target_pid_to_str (lp
->ptid
));
3182 /* But if we don't find a pending event, we'll have to wait. Always
3183 pull all events out of the kernel. We'll randomly select an
3184 event LWP out of all that have events, to prevent starvation. */
3190 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3193 - If the thread group leader exits while other threads in the
3194 thread group still exist, waitpid(TGID, ...) hangs. That
3195 waitpid won't return an exit status until the other threads
3196 in the group are reapped.
3198 - When a non-leader thread execs, that thread just vanishes
3199 without reporting an exit (so we'd hang if we waited for it
3200 explicitly in that case). The exec event is reported to
3204 lwpid
= my_waitpid (-1, &status
, __WALL
| WNOHANG
);
3206 if (debug_linux_nat
)
3207 fprintf_unfiltered (gdb_stdlog
,
3208 "LNW: waitpid(-1, ...) returned %d, %s\n",
3209 lwpid
, errno
? safe_strerror (errno
) : "ERRNO-OK");
3213 if (debug_linux_nat
)
3215 fprintf_unfiltered (gdb_stdlog
,
3216 "LLW: waitpid %ld received %s\n",
3217 (long) lwpid
, status_to_str (status
));
3220 linux_nat_filter_event (lwpid
, status
);
3221 /* Retry until nothing comes out of waitpid. A single
3222 SIGCHLD can indicate more than one child stopped. */
3226 /* Now that we've pulled all events out of the kernel, resume
3227 LWPs that don't have an interesting event to report. */
3228 iterate_over_lwps (minus_one_ptid
,
3229 resume_stopped_resumed_lwps
, &minus_one_ptid
);
3231 /* ... and find an LWP with a status to report to the core, if
3233 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3237 /* Check for zombie thread group leaders. Those can't be reaped
3238 until all other threads in the thread group are. */
3239 check_zombie_leaders ();
3241 /* If there are no resumed children left, bail. We'd be stuck
3242 forever in the sigsuspend call below otherwise. */
3243 if (iterate_over_lwps (ptid
, resumed_callback
, NULL
) == NULL
)
3245 if (debug_linux_nat
)
3246 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (no resumed LWP)\n");
3248 ourstatus
->kind
= TARGET_WAITKIND_NO_RESUMED
;
3250 restore_child_signals_mask (&prev_mask
);
3251 return minus_one_ptid
;
3254 /* No interesting event to report to the core. */
3256 if (target_options
& TARGET_WNOHANG
)
3258 if (debug_linux_nat
)
3259 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (ignore)\n");
3261 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3262 restore_child_signals_mask (&prev_mask
);
3263 return minus_one_ptid
;
3266 /* We shouldn't end up here unless we want to try again. */
3267 gdb_assert (lp
== NULL
);
3269 /* Block until we get an event reported with SIGCHLD. */
3270 if (debug_linux_nat
)
3271 fprintf_unfiltered (gdb_stdlog
, "LNW: about to sigsuspend\n");
3272 sigsuspend (&suspend_mask
);
3277 status
= lp
->status
;
3280 if (!target_is_non_stop_p ())
3282 /* Now stop all other LWP's ... */
3283 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
3285 /* ... and wait until all of them have reported back that
3286 they're no longer running. */
3287 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
3290 /* If we're not waiting for a specific LWP, choose an event LWP from
3291 among those that have had events. Giving equal priority to all
3292 LWPs that have had events helps prevent starvation. */
3293 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3294 select_event_lwp (ptid
, &lp
, &status
);
3296 gdb_assert (lp
!= NULL
);
3298 /* Now that we've selected our final event LWP, un-adjust its PC if
3299 it was a software breakpoint, and we can't reliably support the
3300 "stopped by software breakpoint" stop reason. */
3301 if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3302 && !USE_SIGTRAP_SIGINFO
)
3304 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3305 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3306 int decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3312 pc
= regcache_read_pc (regcache
);
3313 regcache_write_pc (regcache
, pc
+ decr_pc
);
3317 /* We'll need this to determine whether to report a SIGSTOP as
3318 GDB_SIGNAL_0. Need to take a copy because resume_clear_callback
3320 last_resume_kind
= lp
->last_resume_kind
;
3322 if (!target_is_non_stop_p ())
3324 /* In all-stop, from the core's perspective, all LWPs are now
3325 stopped until a new resume action is sent over. */
3326 iterate_over_lwps (minus_one_ptid
, resume_clear_callback
, NULL
);
3330 resume_clear_callback (lp
, NULL
);
3333 if (linux_nat_status_is_event (status
))
3335 if (debug_linux_nat
)
3336 fprintf_unfiltered (gdb_stdlog
,
3337 "LLW: trap ptid is %s.\n",
3338 target_pid_to_str (lp
->ptid
));
3341 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3343 *ourstatus
= lp
->waitstatus
;
3344 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3347 store_waitstatus (ourstatus
, status
);
3349 if (debug_linux_nat
)
3350 fprintf_unfiltered (gdb_stdlog
, "LLW: exit\n");
3352 restore_child_signals_mask (&prev_mask
);
3354 if (last_resume_kind
== resume_stop
3355 && ourstatus
->kind
== TARGET_WAITKIND_STOPPED
3356 && WSTOPSIG (status
) == SIGSTOP
)
3358 /* A thread that has been requested to stop by GDB with
3359 target_stop, and it stopped cleanly, so report as SIG0. The
3360 use of SIGSTOP is an implementation detail. */
3361 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3364 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
3365 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
3368 lp
->core
= linux_common_core_of_thread (lp
->ptid
);
3370 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
)
3371 return filter_exit_event (lp
, ourstatus
);
3376 /* Resume LWPs that are currently stopped without any pending status
3377 to report, but are resumed from the core's perspective. */
3380 resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
)
3382 ptid_t
*wait_ptid_p
= (ptid_t
*) data
;
3386 if (debug_linux_nat
)
3387 fprintf_unfiltered (gdb_stdlog
,
3388 "RSRL: NOT resuming LWP %s, not stopped\n",
3389 target_pid_to_str (lp
->ptid
));
3391 else if (!lp
->resumed
)
3393 if (debug_linux_nat
)
3394 fprintf_unfiltered (gdb_stdlog
,
3395 "RSRL: NOT resuming LWP %s, not resumed\n",
3396 target_pid_to_str (lp
->ptid
));
3398 else if (lwp_status_pending_p (lp
))
3400 if (debug_linux_nat
)
3401 fprintf_unfiltered (gdb_stdlog
,
3402 "RSRL: NOT resuming LWP %s, has pending status\n",
3403 target_pid_to_str (lp
->ptid
));
3407 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3408 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3412 CORE_ADDR pc
= regcache_read_pc (regcache
);
3413 int leave_stopped
= 0;
3415 /* Don't bother if there's a breakpoint at PC that we'd hit
3416 immediately, and we're not waiting for this LWP. */
3417 if (!ptid_match (lp
->ptid
, *wait_ptid_p
))
3419 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
3425 if (debug_linux_nat
)
3426 fprintf_unfiltered (gdb_stdlog
,
3427 "RSRL: resuming stopped-resumed LWP %s at "
3429 target_pid_to_str (lp
->ptid
),
3430 paddress (gdbarch
, pc
),
3433 linux_resume_one_lwp_throw (lp
, lp
->step
, GDB_SIGNAL_0
);
3436 CATCH (ex
, RETURN_MASK_ERROR
)
3438 if (!check_ptrace_stopped_lwp_gone (lp
))
3439 throw_exception (ex
);
3448 linux_nat_wait (struct target_ops
*ops
,
3449 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3454 if (debug_linux_nat
)
3456 char *options_string
;
3458 options_string
= target_options_to_string (target_options
);
3459 fprintf_unfiltered (gdb_stdlog
,
3460 "linux_nat_wait: [%s], [%s]\n",
3461 target_pid_to_str (ptid
),
3463 xfree (options_string
);
3466 /* Flush the async file first. */
3467 if (target_is_async_p ())
3468 async_file_flush ();
3470 /* Resume LWPs that are currently stopped without any pending status
3471 to report, but are resumed from the core's perspective. LWPs get
3472 in this state if we find them stopping at a time we're not
3473 interested in reporting the event (target_wait on a
3474 specific_process, for example, see linux_nat_wait_1), and
3475 meanwhile the event became uninteresting. Don't bother resuming
3476 LWPs we're not going to wait for if they'd stop immediately. */
3477 if (target_is_non_stop_p ())
3478 iterate_over_lwps (minus_one_ptid
, resume_stopped_resumed_lwps
, &ptid
);
3480 event_ptid
= linux_nat_wait_1 (ops
, ptid
, ourstatus
, target_options
);
3482 /* If we requested any event, and something came out, assume there
3483 may be more. If we requested a specific lwp or process, also
3484 assume there may be more. */
3485 if (target_is_async_p ()
3486 && ((ourstatus
->kind
!= TARGET_WAITKIND_IGNORE
3487 && ourstatus
->kind
!= TARGET_WAITKIND_NO_RESUMED
)
3488 || !ptid_equal (ptid
, minus_one_ptid
)))
3497 kill_one_lwp (pid_t pid
)
3499 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3502 kill_lwp (pid
, SIGKILL
);
3503 if (debug_linux_nat
)
3505 int save_errno
= errno
;
3507 fprintf_unfiltered (gdb_stdlog
,
3508 "KC: kill (SIGKILL) %ld, 0, 0 (%s)\n", (long) pid
,
3509 save_errno
? safe_strerror (save_errno
) : "OK");
3512 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3515 ptrace (PTRACE_KILL
, pid
, 0, 0);
3516 if (debug_linux_nat
)
3518 int save_errno
= errno
;
3520 fprintf_unfiltered (gdb_stdlog
,
3521 "KC: PTRACE_KILL %ld, 0, 0 (%s)\n", (long) pid
,
3522 save_errno
? safe_strerror (save_errno
) : "OK");
3526 /* Wait for an LWP to die. */
3529 kill_wait_one_lwp (pid_t pid
)
3533 /* We must make sure that there are no pending events (delayed
3534 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3535 program doesn't interfere with any following debugging session. */
3539 res
= my_waitpid (pid
, NULL
, __WALL
);
3540 if (res
!= (pid_t
) -1)
3542 if (debug_linux_nat
)
3543 fprintf_unfiltered (gdb_stdlog
,
3544 "KWC: wait %ld received unknown.\n",
3546 /* The Linux kernel sometimes fails to kill a thread
3547 completely after PTRACE_KILL; that goes from the stop
3548 point in do_fork out to the one in get_signal_to_deliver
3549 and waits again. So kill it again. */
3555 gdb_assert (res
== -1 && errno
== ECHILD
);
3558 /* Callback for iterate_over_lwps. */
3561 kill_callback (struct lwp_info
*lp
, void *data
)
3563 kill_one_lwp (ptid_get_lwp (lp
->ptid
));
3567 /* Callback for iterate_over_lwps. */
3570 kill_wait_callback (struct lwp_info
*lp
, void *data
)
3572 kill_wait_one_lwp (ptid_get_lwp (lp
->ptid
));
3576 /* Kill the fork children of any threads of inferior INF that are
3577 stopped at a fork event. */
3580 kill_unfollowed_fork_children (struct inferior
*inf
)
3582 struct thread_info
*thread
;
3584 ALL_NON_EXITED_THREADS (thread
)
3585 if (thread
->inf
== inf
)
3587 struct target_waitstatus
*ws
= &thread
->pending_follow
;
3589 if (ws
->kind
== TARGET_WAITKIND_FORKED
3590 || ws
->kind
== TARGET_WAITKIND_VFORKED
)
3592 ptid_t child_ptid
= ws
->value
.related_pid
;
3593 int child_pid
= ptid_get_pid (child_ptid
);
3594 int child_lwp
= ptid_get_lwp (child_ptid
);
3596 kill_one_lwp (child_lwp
);
3597 kill_wait_one_lwp (child_lwp
);
3599 /* Let the arch-specific native code know this process is
3601 linux_nat_forget_process (child_pid
);
3607 linux_nat_kill (struct target_ops
*ops
)
3609 /* If we're stopped while forking and we haven't followed yet,
3610 kill the other task. We need to do this first because the
3611 parent will be sleeping if this is a vfork. */
3612 kill_unfollowed_fork_children (current_inferior ());
3614 if (forks_exist_p ())
3615 linux_fork_killall ();
3618 ptid_t ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
3620 /* Stop all threads before killing them, since ptrace requires
3621 that the thread is stopped to sucessfully PTRACE_KILL. */
3622 iterate_over_lwps (ptid
, stop_callback
, NULL
);
3623 /* ... and wait until all of them have reported back that
3624 they're no longer running. */
3625 iterate_over_lwps (ptid
, stop_wait_callback
, NULL
);
3627 /* Kill all LWP's ... */
3628 iterate_over_lwps (ptid
, kill_callback
, NULL
);
3630 /* ... and wait until we've flushed all events. */
3631 iterate_over_lwps (ptid
, kill_wait_callback
, NULL
);
3634 target_mourn_inferior ();
3638 linux_nat_mourn_inferior (struct target_ops
*ops
)
3640 int pid
= ptid_get_pid (inferior_ptid
);
3642 purge_lwp_list (pid
);
3644 if (! forks_exist_p ())
3645 /* Normal case, no other forks available. */
3646 linux_ops
->to_mourn_inferior (ops
);
3648 /* Multi-fork case. The current inferior_ptid has exited, but
3649 there are other viable forks to debug. Delete the exiting
3650 one and context-switch to the first available. */
3651 linux_fork_mourn_inferior ();
3653 /* Let the arch-specific native code know this process is gone. */
3654 linux_nat_forget_process (pid
);
3657 /* Convert a native/host siginfo object, into/from the siginfo in the
3658 layout of the inferiors' architecture. */
3661 siginfo_fixup (siginfo_t
*siginfo
, gdb_byte
*inf_siginfo
, int direction
)
3665 if (linux_nat_siginfo_fixup
!= NULL
)
3666 done
= linux_nat_siginfo_fixup (siginfo
, inf_siginfo
, direction
);
3668 /* If there was no callback, or the callback didn't do anything,
3669 then just do a straight memcpy. */
3673 memcpy (siginfo
, inf_siginfo
, sizeof (siginfo_t
));
3675 memcpy (inf_siginfo
, siginfo
, sizeof (siginfo_t
));
3679 static enum target_xfer_status
3680 linux_xfer_siginfo (struct target_ops
*ops
, enum target_object object
,
3681 const char *annex
, gdb_byte
*readbuf
,
3682 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
3683 ULONGEST
*xfered_len
)
3687 gdb_byte inf_siginfo
[sizeof (siginfo_t
)];
3689 gdb_assert (object
== TARGET_OBJECT_SIGNAL_INFO
);
3690 gdb_assert (readbuf
|| writebuf
);
3692 pid
= ptid_get_lwp (inferior_ptid
);
3694 pid
= ptid_get_pid (inferior_ptid
);
3696 if (offset
> sizeof (siginfo
))
3697 return TARGET_XFER_E_IO
;
3700 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3702 return TARGET_XFER_E_IO
;
3704 /* When GDB is built as a 64-bit application, ptrace writes into
3705 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3706 inferior with a 64-bit GDB should look the same as debugging it
3707 with a 32-bit GDB, we need to convert it. GDB core always sees
3708 the converted layout, so any read/write will have to be done
3710 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
3712 if (offset
+ len
> sizeof (siginfo
))
3713 len
= sizeof (siginfo
) - offset
;
3715 if (readbuf
!= NULL
)
3716 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
3719 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
3721 /* Convert back to ptrace layout before flushing it out. */
3722 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
3725 ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3727 return TARGET_XFER_E_IO
;
3731 return TARGET_XFER_OK
;
3734 static enum target_xfer_status
3735 linux_nat_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3736 const char *annex
, gdb_byte
*readbuf
,
3737 const gdb_byte
*writebuf
,
3738 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
3740 struct cleanup
*old_chain
;
3741 enum target_xfer_status xfer
;
3743 if (object
== TARGET_OBJECT_SIGNAL_INFO
)
3744 return linux_xfer_siginfo (ops
, object
, annex
, readbuf
, writebuf
,
3745 offset
, len
, xfered_len
);
3747 /* The target is connected but no live inferior is selected. Pass
3748 this request down to a lower stratum (e.g., the executable
3750 if (object
== TARGET_OBJECT_MEMORY
&& ptid_equal (inferior_ptid
, null_ptid
))
3751 return TARGET_XFER_EOF
;
3753 old_chain
= save_inferior_ptid ();
3755 if (ptid_lwp_p (inferior_ptid
))
3756 inferior_ptid
= pid_to_ptid (ptid_get_lwp (inferior_ptid
));
3758 xfer
= linux_ops
->to_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
3759 offset
, len
, xfered_len
);
3761 do_cleanups (old_chain
);
3766 linux_nat_thread_alive (struct target_ops
*ops
, ptid_t ptid
)
3768 /* As long as a PTID is in lwp list, consider it alive. */
3769 return find_lwp_pid (ptid
) != NULL
;
3772 /* Implement the to_update_thread_list target method for this
3776 linux_nat_update_thread_list (struct target_ops
*ops
)
3778 struct lwp_info
*lwp
;
3780 /* We add/delete threads from the list as clone/exit events are
3781 processed, so just try deleting exited threads still in the
3783 delete_exited_threads ();
3785 /* Update the processor core that each lwp/thread was last seen
3788 lwp
->core
= linux_common_core_of_thread (lwp
->ptid
);
3792 linux_nat_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
3794 static char buf
[64];
3796 if (ptid_lwp_p (ptid
)
3797 && (ptid_get_pid (ptid
) != ptid_get_lwp (ptid
)
3798 || num_lwps (ptid_get_pid (ptid
)) > 1))
3800 snprintf (buf
, sizeof (buf
), "LWP %ld", ptid_get_lwp (ptid
));
3804 return normal_pid_to_str (ptid
);
3808 linux_nat_thread_name (struct target_ops
*self
, struct thread_info
*thr
)
3810 return linux_proc_tid_get_name (thr
->ptid
);
3813 /* Accepts an integer PID; Returns a string representing a file that
3814 can be opened to get the symbols for the child process. */
3817 linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
)
3819 return linux_proc_pid_to_exec_file (pid
);
3822 /* Implement the to_xfer_partial interface for memory reads using the /proc
3823 filesystem. Because we can use a single read() call for /proc, this
3824 can be much more efficient than banging away at PTRACE_PEEKTEXT,
3825 but it doesn't support writes. */
3827 static enum target_xfer_status
3828 linux_proc_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3829 const char *annex
, gdb_byte
*readbuf
,
3830 const gdb_byte
*writebuf
,
3831 ULONGEST offset
, LONGEST len
, ULONGEST
*xfered_len
)
3837 if (object
!= TARGET_OBJECT_MEMORY
|| !readbuf
)
3838 return TARGET_XFER_EOF
;
3840 /* Don't bother for one word. */
3841 if (len
< 3 * sizeof (long))
3842 return TARGET_XFER_EOF
;
3844 /* We could keep this file open and cache it - possibly one per
3845 thread. That requires some juggling, but is even faster. */
3846 xsnprintf (filename
, sizeof filename
, "/proc/%d/mem",
3847 ptid_get_pid (inferior_ptid
));
3848 fd
= gdb_open_cloexec (filename
, O_RDONLY
| O_LARGEFILE
, 0);
3850 return TARGET_XFER_EOF
;
3852 /* If pread64 is available, use it. It's faster if the kernel
3853 supports it (only one syscall), and it's 64-bit safe even on
3854 32-bit platforms (for instance, SPARC debugging a SPARC64
3857 if (pread64 (fd
, readbuf
, len
, offset
) != len
)
3859 if (lseek (fd
, offset
, SEEK_SET
) == -1 || read (fd
, readbuf
, len
) != len
)
3868 return TARGET_XFER_EOF
;
3872 return TARGET_XFER_OK
;
3877 /* Enumerate spufs IDs for process PID. */
3879 spu_enumerate_spu_ids (int pid
, gdb_byte
*buf
, ULONGEST offset
, ULONGEST len
)
3881 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
3883 LONGEST written
= 0;
3886 struct dirent
*entry
;
3888 xsnprintf (path
, sizeof path
, "/proc/%d/fd", pid
);
3889 dir
= opendir (path
);
3894 while ((entry
= readdir (dir
)) != NULL
)
3900 fd
= atoi (entry
->d_name
);
3904 xsnprintf (path
, sizeof path
, "/proc/%d/fd/%d", pid
, fd
);
3905 if (stat (path
, &st
) != 0)
3907 if (!S_ISDIR (st
.st_mode
))
3910 if (statfs (path
, &stfs
) != 0)
3912 if (stfs
.f_type
!= SPUFS_MAGIC
)
3915 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
3917 store_unsigned_integer (buf
+ pos
- offset
, 4, byte_order
, fd
);
3927 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
3928 object type, using the /proc file system. */
3930 static enum target_xfer_status
3931 linux_proc_xfer_spu (struct target_ops
*ops
, enum target_object object
,
3932 const char *annex
, gdb_byte
*readbuf
,
3933 const gdb_byte
*writebuf
,
3934 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
3939 int pid
= ptid_get_pid (inferior_ptid
);
3944 return TARGET_XFER_E_IO
;
3947 LONGEST l
= spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
3950 return TARGET_XFER_E_IO
;
3952 return TARGET_XFER_EOF
;
3955 *xfered_len
= (ULONGEST
) l
;
3956 return TARGET_XFER_OK
;
3961 xsnprintf (buf
, sizeof buf
, "/proc/%d/fd/%s", pid
, annex
);
3962 fd
= gdb_open_cloexec (buf
, writebuf
? O_WRONLY
: O_RDONLY
, 0);
3964 return TARGET_XFER_E_IO
;
3967 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
3970 return TARGET_XFER_EOF
;
3974 ret
= write (fd
, writebuf
, (size_t) len
);
3976 ret
= read (fd
, readbuf
, (size_t) len
);
3981 return TARGET_XFER_E_IO
;
3983 return TARGET_XFER_EOF
;
3986 *xfered_len
= (ULONGEST
) ret
;
3987 return TARGET_XFER_OK
;
3992 /* Parse LINE as a signal set and add its set bits to SIGS. */
3995 add_line_to_sigset (const char *line
, sigset_t
*sigs
)
3997 int len
= strlen (line
) - 1;
4001 if (line
[len
] != '\n')
4002 error (_("Could not parse signal set: %s"), line
);
4010 if (*p
>= '0' && *p
<= '9')
4012 else if (*p
>= 'a' && *p
<= 'f')
4013 digit
= *p
- 'a' + 10;
4015 error (_("Could not parse signal set: %s"), line
);
4020 sigaddset (sigs
, signum
+ 1);
4022 sigaddset (sigs
, signum
+ 2);
4024 sigaddset (sigs
, signum
+ 3);
4026 sigaddset (sigs
, signum
+ 4);
4032 /* Find process PID's pending signals from /proc/pid/status and set
4036 linux_proc_pending_signals (int pid
, sigset_t
*pending
,
4037 sigset_t
*blocked
, sigset_t
*ignored
)
4040 char buffer
[PATH_MAX
], fname
[PATH_MAX
];
4041 struct cleanup
*cleanup
;
4043 sigemptyset (pending
);
4044 sigemptyset (blocked
);
4045 sigemptyset (ignored
);
4046 xsnprintf (fname
, sizeof fname
, "/proc/%d/status", pid
);
4047 procfile
= gdb_fopen_cloexec (fname
, "r");
4048 if (procfile
== NULL
)
4049 error (_("Could not open %s"), fname
);
4050 cleanup
= make_cleanup_fclose (procfile
);
4052 while (fgets (buffer
, PATH_MAX
, procfile
) != NULL
)
4054 /* Normal queued signals are on the SigPnd line in the status
4055 file. However, 2.6 kernels also have a "shared" pending
4056 queue for delivering signals to a thread group, so check for
4059 Unfortunately some Red Hat kernels include the shared pending
4060 queue but not the ShdPnd status field. */
4062 if (startswith (buffer
, "SigPnd:\t"))
4063 add_line_to_sigset (buffer
+ 8, pending
);
4064 else if (startswith (buffer
, "ShdPnd:\t"))
4065 add_line_to_sigset (buffer
+ 8, pending
);
4066 else if (startswith (buffer
, "SigBlk:\t"))
4067 add_line_to_sigset (buffer
+ 8, blocked
);
4068 else if (startswith (buffer
, "SigIgn:\t"))
4069 add_line_to_sigset (buffer
+ 8, ignored
);
4072 do_cleanups (cleanup
);
4075 static enum target_xfer_status
4076 linux_nat_xfer_osdata (struct target_ops
*ops
, enum target_object object
,
4077 const char *annex
, gdb_byte
*readbuf
,
4078 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4079 ULONGEST
*xfered_len
)
4081 gdb_assert (object
== TARGET_OBJECT_OSDATA
);
4083 *xfered_len
= linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
4084 if (*xfered_len
== 0)
4085 return TARGET_XFER_EOF
;
4087 return TARGET_XFER_OK
;
4090 static enum target_xfer_status
4091 linux_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4092 const char *annex
, gdb_byte
*readbuf
,
4093 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4094 ULONGEST
*xfered_len
)
4096 enum target_xfer_status xfer
;
4098 if (object
== TARGET_OBJECT_AUXV
)
4099 return memory_xfer_auxv (ops
, object
, annex
, readbuf
, writebuf
,
4100 offset
, len
, xfered_len
);
4102 if (object
== TARGET_OBJECT_OSDATA
)
4103 return linux_nat_xfer_osdata (ops
, object
, annex
, readbuf
, writebuf
,
4104 offset
, len
, xfered_len
);
4106 if (object
== TARGET_OBJECT_SPU
)
4107 return linux_proc_xfer_spu (ops
, object
, annex
, readbuf
, writebuf
,
4108 offset
, len
, xfered_len
);
4110 /* GDB calculates all the addresses in possibly larget width of the address.
4111 Address width needs to be masked before its final use - either by
4112 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4114 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4116 if (object
== TARGET_OBJECT_MEMORY
)
4118 int addr_bit
= gdbarch_addr_bit (target_gdbarch ());
4120 if (addr_bit
< (sizeof (ULONGEST
) * HOST_CHAR_BIT
))
4121 offset
&= ((ULONGEST
) 1 << addr_bit
) - 1;
4124 xfer
= linux_proc_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4125 offset
, len
, xfered_len
);
4126 if (xfer
!= TARGET_XFER_EOF
)
4129 return super_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4130 offset
, len
, xfered_len
);
4134 cleanup_target_stop (void *arg
)
4136 ptid_t
*ptid
= (ptid_t
*) arg
;
4138 gdb_assert (arg
!= NULL
);
4141 target_resume (*ptid
, 0, GDB_SIGNAL_0
);
4144 static VEC(static_tracepoint_marker_p
) *
4145 linux_child_static_tracepoint_markers_by_strid (struct target_ops
*self
,
4148 char s
[IPA_CMD_BUF_SIZE
];
4149 struct cleanup
*old_chain
;
4150 int pid
= ptid_get_pid (inferior_ptid
);
4151 VEC(static_tracepoint_marker_p
) *markers
= NULL
;
4152 struct static_tracepoint_marker
*marker
= NULL
;
4154 ptid_t ptid
= ptid_build (pid
, 0, 0);
4159 memcpy (s
, "qTfSTM", sizeof ("qTfSTM"));
4160 s
[sizeof ("qTfSTM")] = 0;
4162 agent_run_command (pid
, s
, strlen (s
) + 1);
4164 old_chain
= make_cleanup (free_current_marker
, &marker
);
4165 make_cleanup (cleanup_target_stop
, &ptid
);
4170 marker
= XCNEW (struct static_tracepoint_marker
);
4174 parse_static_tracepoint_marker_definition (p
, &p
, marker
);
4176 if (strid
== NULL
|| strcmp (strid
, marker
->str_id
) == 0)
4178 VEC_safe_push (static_tracepoint_marker_p
,
4184 release_static_tracepoint_marker (marker
);
4185 memset (marker
, 0, sizeof (*marker
));
4188 while (*p
++ == ','); /* comma-separated list */
4190 memcpy (s
, "qTsSTM", sizeof ("qTsSTM"));
4191 s
[sizeof ("qTsSTM")] = 0;
4192 agent_run_command (pid
, s
, strlen (s
) + 1);
4196 do_cleanups (old_chain
);
4201 /* Create a prototype generic GNU/Linux target. The client can override
4202 it with local methods. */
4205 linux_target_install_ops (struct target_ops
*t
)
4207 t
->to_insert_fork_catchpoint
= linux_child_insert_fork_catchpoint
;
4208 t
->to_remove_fork_catchpoint
= linux_child_remove_fork_catchpoint
;
4209 t
->to_insert_vfork_catchpoint
= linux_child_insert_vfork_catchpoint
;
4210 t
->to_remove_vfork_catchpoint
= linux_child_remove_vfork_catchpoint
;
4211 t
->to_insert_exec_catchpoint
= linux_child_insert_exec_catchpoint
;
4212 t
->to_remove_exec_catchpoint
= linux_child_remove_exec_catchpoint
;
4213 t
->to_set_syscall_catchpoint
= linux_child_set_syscall_catchpoint
;
4214 t
->to_pid_to_exec_file
= linux_child_pid_to_exec_file
;
4215 t
->to_post_startup_inferior
= linux_child_post_startup_inferior
;
4216 t
->to_post_attach
= linux_child_post_attach
;
4217 t
->to_follow_fork
= linux_child_follow_fork
;
4219 super_xfer_partial
= t
->to_xfer_partial
;
4220 t
->to_xfer_partial
= linux_xfer_partial
;
4222 t
->to_static_tracepoint_markers_by_strid
4223 = linux_child_static_tracepoint_markers_by_strid
;
4229 struct target_ops
*t
;
4231 t
= inf_ptrace_target ();
4232 linux_target_install_ops (t
);
4238 linux_trad_target (CORE_ADDR (*register_u_offset
)(struct gdbarch
*, int, int))
4240 struct target_ops
*t
;
4242 t
= inf_ptrace_trad_target (register_u_offset
);
4243 linux_target_install_ops (t
);
4248 /* target_is_async_p implementation. */
4251 linux_nat_is_async_p (struct target_ops
*ops
)
4253 return linux_is_async_p ();
4256 /* target_can_async_p implementation. */
4259 linux_nat_can_async_p (struct target_ops
*ops
)
4261 /* NOTE: palves 2008-03-21: We're only async when the user requests
4262 it explicitly with the "set target-async" command.
4263 Someday, linux will always be async. */
4264 return target_async_permitted
;
4268 linux_nat_supports_non_stop (struct target_ops
*self
)
4273 /* to_always_non_stop_p implementation. */
4276 linux_nat_always_non_stop_p (struct target_ops
*self
)
4281 /* True if we want to support multi-process. To be removed when GDB
4282 supports multi-exec. */
4284 int linux_multi_process
= 1;
4287 linux_nat_supports_multi_process (struct target_ops
*self
)
4289 return linux_multi_process
;
4293 linux_nat_supports_disable_randomization (struct target_ops
*self
)
4295 #ifdef HAVE_PERSONALITY
4302 static int async_terminal_is_ours
= 1;
4304 /* target_terminal_inferior implementation.
4306 This is a wrapper around child_terminal_inferior to add async support. */
4309 linux_nat_terminal_inferior (struct target_ops
*self
)
4311 child_terminal_inferior (self
);
4313 /* Calls to target_terminal_*() are meant to be idempotent. */
4314 if (!async_terminal_is_ours
)
4317 delete_file_handler (input_fd
);
4318 async_terminal_is_ours
= 0;
4322 /* target_terminal_ours implementation.
4324 This is a wrapper around child_terminal_ours to add async support (and
4325 implement the target_terminal_ours vs target_terminal_ours_for_output
4326 distinction). child_terminal_ours is currently no different than
4327 child_terminal_ours_for_output.
4328 We leave target_terminal_ours_for_output alone, leaving it to
4329 child_terminal_ours_for_output. */
4332 linux_nat_terminal_ours (struct target_ops
*self
)
4334 /* GDB should never give the terminal to the inferior if the
4335 inferior is running in the background (run&, continue&, etc.),
4336 but claiming it sure should. */
4337 child_terminal_ours (self
);
4339 if (async_terminal_is_ours
)
4342 clear_sigint_trap ();
4343 add_file_handler (input_fd
, stdin_event_handler
, 0);
4344 async_terminal_is_ours
= 1;
4347 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4348 so we notice when any child changes state, and notify the
4349 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4350 above to wait for the arrival of a SIGCHLD. */
4353 sigchld_handler (int signo
)
4355 int old_errno
= errno
;
4357 if (debug_linux_nat
)
4358 ui_file_write_async_safe (gdb_stdlog
,
4359 "sigchld\n", sizeof ("sigchld\n") - 1);
4361 if (signo
== SIGCHLD
4362 && linux_nat_event_pipe
[0] != -1)
4363 async_file_mark (); /* Let the event loop know that there are
4364 events to handle. */
4369 /* Callback registered with the target events file descriptor. */
4372 handle_target_event (int error
, gdb_client_data client_data
)
4374 inferior_event_handler (INF_REG_EVENT
, NULL
);
4377 /* Create/destroy the target events pipe. Returns previous state. */
4380 linux_async_pipe (int enable
)
4382 int previous
= linux_is_async_p ();
4384 if (previous
!= enable
)
4388 /* Block child signals while we create/destroy the pipe, as
4389 their handler writes to it. */
4390 block_child_signals (&prev_mask
);
4394 if (gdb_pipe_cloexec (linux_nat_event_pipe
) == -1)
4395 internal_error (__FILE__
, __LINE__
,
4396 "creating event pipe failed.");
4398 fcntl (linux_nat_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4399 fcntl (linux_nat_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4403 close (linux_nat_event_pipe
[0]);
4404 close (linux_nat_event_pipe
[1]);
4405 linux_nat_event_pipe
[0] = -1;
4406 linux_nat_event_pipe
[1] = -1;
4409 restore_child_signals_mask (&prev_mask
);
4415 /* target_async implementation. */
4418 linux_nat_async (struct target_ops
*ops
, int enable
)
4422 if (!linux_async_pipe (1))
4424 add_file_handler (linux_nat_event_pipe
[0],
4425 handle_target_event
, NULL
);
4426 /* There may be pending events to handle. Tell the event loop
4433 delete_file_handler (linux_nat_event_pipe
[0]);
4434 linux_async_pipe (0);
4439 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4443 linux_nat_stop_lwp (struct lwp_info
*lwp
, void *data
)
4447 if (debug_linux_nat
)
4448 fprintf_unfiltered (gdb_stdlog
,
4449 "LNSL: running -> suspending %s\n",
4450 target_pid_to_str (lwp
->ptid
));
4453 if (lwp
->last_resume_kind
== resume_stop
)
4455 if (debug_linux_nat
)
4456 fprintf_unfiltered (gdb_stdlog
,
4457 "linux-nat: already stopping LWP %ld at "
4459 ptid_get_lwp (lwp
->ptid
));
4463 stop_callback (lwp
, NULL
);
4464 lwp
->last_resume_kind
= resume_stop
;
4468 /* Already known to be stopped; do nothing. */
4470 if (debug_linux_nat
)
4472 if (find_thread_ptid (lwp
->ptid
)->stop_requested
)
4473 fprintf_unfiltered (gdb_stdlog
,
4474 "LNSL: already stopped/stop_requested %s\n",
4475 target_pid_to_str (lwp
->ptid
));
4477 fprintf_unfiltered (gdb_stdlog
,
4478 "LNSL: already stopped/no "
4479 "stop_requested yet %s\n",
4480 target_pid_to_str (lwp
->ptid
));
4487 linux_nat_stop (struct target_ops
*self
, ptid_t ptid
)
4489 iterate_over_lwps (ptid
, linux_nat_stop_lwp
, NULL
);
4493 linux_nat_close (struct target_ops
*self
)
4495 /* Unregister from the event loop. */
4496 if (linux_nat_is_async_p (self
))
4497 linux_nat_async (self
, 0);
4499 if (linux_ops
->to_close
)
4500 linux_ops
->to_close (linux_ops
);
4505 /* When requests are passed down from the linux-nat layer to the
4506 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4507 used. The address space pointer is stored in the inferior object,
4508 but the common code that is passed such ptid can't tell whether
4509 lwpid is a "main" process id or not (it assumes so). We reverse
4510 look up the "main" process id from the lwp here. */
4512 static struct address_space
*
4513 linux_nat_thread_address_space (struct target_ops
*t
, ptid_t ptid
)
4515 struct lwp_info
*lwp
;
4516 struct inferior
*inf
;
4519 if (ptid_get_lwp (ptid
) == 0)
4521 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4523 lwp
= find_lwp_pid (ptid
);
4524 pid
= ptid_get_pid (lwp
->ptid
);
4528 /* A (pid,lwpid,0) ptid. */
4529 pid
= ptid_get_pid (ptid
);
4532 inf
= find_inferior_pid (pid
);
4533 gdb_assert (inf
!= NULL
);
4537 /* Return the cached value of the processor core for thread PTID. */
4540 linux_nat_core_of_thread (struct target_ops
*ops
, ptid_t ptid
)
4542 struct lwp_info
*info
= find_lwp_pid (ptid
);
4549 /* Implementation of to_filesystem_is_local. */
4552 linux_nat_filesystem_is_local (struct target_ops
*ops
)
4554 struct inferior
*inf
= current_inferior ();
4556 if (inf
->fake_pid_p
|| inf
->pid
== 0)
4559 return linux_ns_same (inf
->pid
, LINUX_NS_MNT
);
4562 /* Convert the INF argument passed to a to_fileio_* method
4563 to a process ID suitable for passing to its corresponding
4564 linux_mntns_* function. If INF is non-NULL then the
4565 caller is requesting the filesystem seen by INF. If INF
4566 is NULL then the caller is requesting the filesystem seen
4567 by the GDB. We fall back to GDB's filesystem in the case
4568 that INF is non-NULL but its PID is unknown. */
4571 linux_nat_fileio_pid_of (struct inferior
*inf
)
4573 if (inf
== NULL
|| inf
->fake_pid_p
|| inf
->pid
== 0)
4579 /* Implementation of to_fileio_open. */
4582 linux_nat_fileio_open (struct target_ops
*self
,
4583 struct inferior
*inf
, const char *filename
,
4584 int flags
, int mode
, int warn_if_slow
,
4591 if (fileio_to_host_openflags (flags
, &nat_flags
) == -1
4592 || fileio_to_host_mode (mode
, &nat_mode
) == -1)
4594 *target_errno
= FILEIO_EINVAL
;
4598 fd
= linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf
),
4599 filename
, nat_flags
, nat_mode
);
4601 *target_errno
= host_to_fileio_error (errno
);
4606 /* Implementation of to_fileio_readlink. */
4609 linux_nat_fileio_readlink (struct target_ops
*self
,
4610 struct inferior
*inf
, const char *filename
,
4617 len
= linux_mntns_readlink (linux_nat_fileio_pid_of (inf
),
4618 filename
, buf
, sizeof (buf
));
4621 *target_errno
= host_to_fileio_error (errno
);
4625 ret
= (char *) xmalloc (len
+ 1);
4626 memcpy (ret
, buf
, len
);
4631 /* Implementation of to_fileio_unlink. */
4634 linux_nat_fileio_unlink (struct target_ops
*self
,
4635 struct inferior
*inf
, const char *filename
,
4640 ret
= linux_mntns_unlink (linux_nat_fileio_pid_of (inf
),
4643 *target_errno
= host_to_fileio_error (errno
);
4648 /* Implementation of the to_thread_events method. */
4651 linux_nat_thread_events (struct target_ops
*ops
, int enable
)
4653 report_thread_events
= enable
;
4657 linux_nat_add_target (struct target_ops
*t
)
4659 /* Save the provided single-threaded target. We save this in a separate
4660 variable because another target we've inherited from (e.g. inf-ptrace)
4661 may have saved a pointer to T; we want to use it for the final
4662 process stratum target. */
4663 linux_ops_saved
= *t
;
4664 linux_ops
= &linux_ops_saved
;
4666 /* Override some methods for multithreading. */
4667 t
->to_create_inferior
= linux_nat_create_inferior
;
4668 t
->to_attach
= linux_nat_attach
;
4669 t
->to_detach
= linux_nat_detach
;
4670 t
->to_resume
= linux_nat_resume
;
4671 t
->to_wait
= linux_nat_wait
;
4672 t
->to_pass_signals
= linux_nat_pass_signals
;
4673 t
->to_xfer_partial
= linux_nat_xfer_partial
;
4674 t
->to_kill
= linux_nat_kill
;
4675 t
->to_mourn_inferior
= linux_nat_mourn_inferior
;
4676 t
->to_thread_alive
= linux_nat_thread_alive
;
4677 t
->to_update_thread_list
= linux_nat_update_thread_list
;
4678 t
->to_pid_to_str
= linux_nat_pid_to_str
;
4679 t
->to_thread_name
= linux_nat_thread_name
;
4680 t
->to_has_thread_control
= tc_schedlock
;
4681 t
->to_thread_address_space
= linux_nat_thread_address_space
;
4682 t
->to_stopped_by_watchpoint
= linux_nat_stopped_by_watchpoint
;
4683 t
->to_stopped_data_address
= linux_nat_stopped_data_address
;
4684 t
->to_stopped_by_sw_breakpoint
= linux_nat_stopped_by_sw_breakpoint
;
4685 t
->to_supports_stopped_by_sw_breakpoint
= linux_nat_supports_stopped_by_sw_breakpoint
;
4686 t
->to_stopped_by_hw_breakpoint
= linux_nat_stopped_by_hw_breakpoint
;
4687 t
->to_supports_stopped_by_hw_breakpoint
= linux_nat_supports_stopped_by_hw_breakpoint
;
4688 t
->to_thread_events
= linux_nat_thread_events
;
4690 t
->to_can_async_p
= linux_nat_can_async_p
;
4691 t
->to_is_async_p
= linux_nat_is_async_p
;
4692 t
->to_supports_non_stop
= linux_nat_supports_non_stop
;
4693 t
->to_always_non_stop_p
= linux_nat_always_non_stop_p
;
4694 t
->to_async
= linux_nat_async
;
4695 t
->to_terminal_inferior
= linux_nat_terminal_inferior
;
4696 t
->to_terminal_ours
= linux_nat_terminal_ours
;
4698 super_close
= t
->to_close
;
4699 t
->to_close
= linux_nat_close
;
4701 t
->to_stop
= linux_nat_stop
;
4703 t
->to_supports_multi_process
= linux_nat_supports_multi_process
;
4705 t
->to_supports_disable_randomization
4706 = linux_nat_supports_disable_randomization
;
4708 t
->to_core_of_thread
= linux_nat_core_of_thread
;
4710 t
->to_filesystem_is_local
= linux_nat_filesystem_is_local
;
4711 t
->to_fileio_open
= linux_nat_fileio_open
;
4712 t
->to_fileio_readlink
= linux_nat_fileio_readlink
;
4713 t
->to_fileio_unlink
= linux_nat_fileio_unlink
;
4715 /* We don't change the stratum; this target will sit at
4716 process_stratum and thread_db will set at thread_stratum. This
4717 is a little strange, since this is a multi-threaded-capable
4718 target, but we want to be on the stack below thread_db, and we
4719 also want to be used for single-threaded processes. */
4724 /* Register a method to call whenever a new thread is attached. */
4726 linux_nat_set_new_thread (struct target_ops
*t
,
4727 void (*new_thread
) (struct lwp_info
*))
4729 /* Save the pointer. We only support a single registered instance
4730 of the GNU/Linux native target, so we do not need to map this to
4732 linux_nat_new_thread
= new_thread
;
4735 /* See declaration in linux-nat.h. */
4738 linux_nat_set_new_fork (struct target_ops
*t
,
4739 linux_nat_new_fork_ftype
*new_fork
)
4741 /* Save the pointer. */
4742 linux_nat_new_fork
= new_fork
;
4745 /* See declaration in linux-nat.h. */
4748 linux_nat_set_forget_process (struct target_ops
*t
,
4749 linux_nat_forget_process_ftype
*fn
)
4751 /* Save the pointer. */
4752 linux_nat_forget_process_hook
= fn
;
4755 /* See declaration in linux-nat.h. */
4758 linux_nat_forget_process (pid_t pid
)
4760 if (linux_nat_forget_process_hook
!= NULL
)
4761 linux_nat_forget_process_hook (pid
);
4764 /* Register a method that converts a siginfo object between the layout
4765 that ptrace returns, and the layout in the architecture of the
4768 linux_nat_set_siginfo_fixup (struct target_ops
*t
,
4769 int (*siginfo_fixup
) (siginfo_t
*,
4773 /* Save the pointer. */
4774 linux_nat_siginfo_fixup
= siginfo_fixup
;
4777 /* Register a method to call prior to resuming a thread. */
4780 linux_nat_set_prepare_to_resume (struct target_ops
*t
,
4781 void (*prepare_to_resume
) (struct lwp_info
*))
4783 /* Save the pointer. */
4784 linux_nat_prepare_to_resume
= prepare_to_resume
;
4787 /* See linux-nat.h. */
4790 linux_nat_get_siginfo (ptid_t ptid
, siginfo_t
*siginfo
)
4794 pid
= ptid_get_lwp (ptid
);
4796 pid
= ptid_get_pid (ptid
);
4799 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, siginfo
);
4802 memset (siginfo
, 0, sizeof (*siginfo
));
4808 /* See nat/linux-nat.h. */
4811 current_lwp_ptid (void)
4813 gdb_assert (ptid_lwp_p (inferior_ptid
));
4814 return inferior_ptid
;
4817 /* Provide a prototype to silence -Wmissing-prototypes. */
4818 extern initialize_file_ftype _initialize_linux_nat
;
4821 _initialize_linux_nat (void)
4823 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance
,
4824 &debug_linux_nat
, _("\
4825 Set debugging of GNU/Linux lwp module."), _("\
4826 Show debugging of GNU/Linux lwp module."), _("\
4827 Enables printf debugging output."),
4829 show_debug_linux_nat
,
4830 &setdebuglist
, &showdebuglist
);
4832 add_setshow_boolean_cmd ("linux-namespaces", class_maintenance
,
4833 &debug_linux_namespaces
, _("\
4834 Set debugging of GNU/Linux namespaces module."), _("\
4835 Show debugging of GNU/Linux namespaces module."), _("\
4836 Enables printf debugging output."),
4839 &setdebuglist
, &showdebuglist
);
4841 /* Save this mask as the default. */
4842 sigprocmask (SIG_SETMASK
, NULL
, &normal_mask
);
4844 /* Install a SIGCHLD handler. */
4845 sigchld_action
.sa_handler
= sigchld_handler
;
4846 sigemptyset (&sigchld_action
.sa_mask
);
4847 sigchld_action
.sa_flags
= SA_RESTART
;
4849 /* Make it the default. */
4850 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
4852 /* Make sure we don't block SIGCHLD during a sigsuspend. */
4853 sigprocmask (SIG_SETMASK
, NULL
, &suspend_mask
);
4854 sigdelset (&suspend_mask
, SIGCHLD
);
4856 sigemptyset (&blocked_mask
);
4860 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
4861 the GNU/Linux Threads library and therefore doesn't really belong
4864 /* Return the set of signals used by the threads library in *SET. */
4867 lin_thread_get_thread_signals (sigset_t
*set
)
4871 /* NPTL reserves the first two RT signals, but does not provide any
4872 way for the debugger to query the signal numbers - fortunately
4873 they don't change. */
4874 sigaddset (set
, __SIGRTMIN
);
4875 sigaddset (set
, __SIGRTMIN
+ 1);