1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001-2017 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
;
358 /* See nat/linux-nat.h. */
361 lwp_is_stepping (struct lwp_info
*lwp
)
367 /* Trivial list manipulation functions to keep track of a list of
368 new stopped processes. */
370 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
372 struct simple_pid_list
*new_pid
= XNEW (struct simple_pid_list
);
375 new_pid
->status
= status
;
376 new_pid
->next
= *listp
;
381 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *statusp
)
383 struct simple_pid_list
**p
;
385 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
386 if ((*p
)->pid
== pid
)
388 struct simple_pid_list
*next
= (*p
)->next
;
390 *statusp
= (*p
)->status
;
398 /* Return the ptrace options that we want to try to enable. */
401 linux_nat_ptrace_options (int attached
)
406 options
|= PTRACE_O_EXITKILL
;
408 options
|= (PTRACE_O_TRACESYSGOOD
409 | PTRACE_O_TRACEVFORKDONE
410 | PTRACE_O_TRACEVFORK
412 | PTRACE_O_TRACEEXEC
);
417 /* Initialize ptrace warnings and check for supported ptrace
420 ATTACHED should be nonzero iff we attached to the inferior. */
423 linux_init_ptrace (pid_t pid
, int attached
)
425 int options
= linux_nat_ptrace_options (attached
);
427 linux_enable_event_reporting (pid
, options
);
428 linux_ptrace_init_warnings ();
432 linux_child_post_attach (struct target_ops
*self
, int pid
)
434 linux_init_ptrace (pid
, 1);
438 linux_child_post_startup_inferior (struct target_ops
*self
, ptid_t ptid
)
440 linux_init_ptrace (ptid_get_pid (ptid
), 0);
443 /* Return the number of known LWPs in the tgid given by PID. */
451 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
452 if (ptid_get_pid (lp
->ptid
) == pid
)
458 /* Call delete_lwp with prototype compatible for make_cleanup. */
461 delete_lwp_cleanup (void *lp_voidp
)
463 struct lwp_info
*lp
= (struct lwp_info
*) lp_voidp
;
465 delete_lwp (lp
->ptid
);
468 /* Target hook for follow_fork. On entry inferior_ptid must be the
469 ptid of the followed inferior. At return, inferior_ptid will be
473 linux_child_follow_fork (struct target_ops
*ops
, int follow_child
,
478 struct lwp_info
*child_lp
= NULL
;
479 int status
= W_STOPCODE (0);
480 struct cleanup
*old_chain
;
482 ptid_t parent_ptid
, child_ptid
;
483 int parent_pid
, child_pid
;
485 has_vforked
= (inferior_thread ()->pending_follow
.kind
486 == TARGET_WAITKIND_VFORKED
);
487 parent_ptid
= inferior_ptid
;
488 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
489 parent_pid
= ptid_get_lwp (parent_ptid
);
490 child_pid
= ptid_get_lwp (child_ptid
);
492 /* We're already attached to the parent, by default. */
493 old_chain
= save_inferior_ptid ();
494 inferior_ptid
= child_ptid
;
495 child_lp
= add_lwp (inferior_ptid
);
496 child_lp
->stopped
= 1;
497 child_lp
->last_resume_kind
= resume_stop
;
499 /* Detach new forked process? */
502 make_cleanup (delete_lwp_cleanup
, child_lp
);
504 if (linux_nat_prepare_to_resume
!= NULL
)
505 linux_nat_prepare_to_resume (child_lp
);
507 /* When debugging an inferior in an architecture that supports
508 hardware single stepping on a kernel without commit
509 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child
510 process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits
511 set if the parent process had them set.
512 To work around this, single step the child process
513 once before detaching to clear the flags. */
515 if (!gdbarch_software_single_step_p (target_thread_architecture
518 linux_disable_event_reporting (child_pid
);
519 if (ptrace (PTRACE_SINGLESTEP
, child_pid
, 0, 0) < 0)
520 perror_with_name (_("Couldn't do single step"));
521 if (my_waitpid (child_pid
, &status
, 0) < 0)
522 perror_with_name (_("Couldn't wait vfork process"));
525 if (WIFSTOPPED (status
))
529 signo
= WSTOPSIG (status
);
531 && !signal_pass_state (gdb_signal_from_host (signo
)))
533 ptrace (PTRACE_DETACH
, child_pid
, 0, signo
);
536 /* Resets value of inferior_ptid to parent ptid. */
537 do_cleanups (old_chain
);
541 /* Let the thread_db layer learn about this new process. */
542 check_for_thread_db ();
545 do_cleanups (old_chain
);
549 struct lwp_info
*parent_lp
;
551 parent_lp
= find_lwp_pid (parent_ptid
);
552 gdb_assert (linux_supports_tracefork () >= 0);
554 if (linux_supports_tracevforkdone ())
557 fprintf_unfiltered (gdb_stdlog
,
558 "LCFF: waiting for VFORK_DONE on %d\n",
560 parent_lp
->stopped
= 1;
562 /* We'll handle the VFORK_DONE event like any other
563 event, in target_wait. */
567 /* We can't insert breakpoints until the child has
568 finished with the shared memory region. We need to
569 wait until that happens. Ideal would be to just
571 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
572 - waitpid (parent_pid, &status, __WALL);
573 However, most architectures can't handle a syscall
574 being traced on the way out if it wasn't traced on
577 We might also think to loop, continuing the child
578 until it exits or gets a SIGTRAP. One problem is
579 that the child might call ptrace with PTRACE_TRACEME.
581 There's no simple and reliable way to figure out when
582 the vforked child will be done with its copy of the
583 shared memory. We could step it out of the syscall,
584 two instructions, let it go, and then single-step the
585 parent once. When we have hardware single-step, this
586 would work; with software single-step it could still
587 be made to work but we'd have to be able to insert
588 single-step breakpoints in the child, and we'd have
589 to insert -just- the single-step breakpoint in the
590 parent. Very awkward.
592 In the end, the best we can do is to make sure it
593 runs for a little while. Hopefully it will be out of
594 range of any breakpoints we reinsert. Usually this
595 is only the single-step breakpoint at vfork's return
599 fprintf_unfiltered (gdb_stdlog
,
600 "LCFF: no VFORK_DONE "
601 "support, sleeping a bit\n");
605 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
606 and leave it pending. The next linux_nat_resume call
607 will notice a pending event, and bypasses actually
608 resuming the inferior. */
609 parent_lp
->status
= 0;
610 parent_lp
->waitstatus
.kind
= TARGET_WAITKIND_VFORK_DONE
;
611 parent_lp
->stopped
= 1;
613 /* If we're in async mode, need to tell the event loop
614 there's something here to process. */
615 if (target_is_async_p ())
622 struct lwp_info
*child_lp
;
624 child_lp
= add_lwp (inferior_ptid
);
625 child_lp
->stopped
= 1;
626 child_lp
->last_resume_kind
= resume_stop
;
628 /* Let the thread_db layer learn about this new process. */
629 check_for_thread_db ();
637 linux_child_insert_fork_catchpoint (struct target_ops
*self
, int pid
)
639 return !linux_supports_tracefork ();
643 linux_child_remove_fork_catchpoint (struct target_ops
*self
, int pid
)
649 linux_child_insert_vfork_catchpoint (struct target_ops
*self
, int pid
)
651 return !linux_supports_tracefork ();
655 linux_child_remove_vfork_catchpoint (struct target_ops
*self
, int pid
)
661 linux_child_insert_exec_catchpoint (struct target_ops
*self
, int pid
)
663 return !linux_supports_tracefork ();
667 linux_child_remove_exec_catchpoint (struct target_ops
*self
, int pid
)
673 linux_child_set_syscall_catchpoint (struct target_ops
*self
,
674 int pid
, int needed
, int any_count
,
675 int table_size
, int *table
)
677 if (!linux_supports_tracesysgood ())
680 /* On GNU/Linux, we ignore the arguments. It means that we only
681 enable the syscall catchpoints, but do not disable them.
683 Also, we do not use the `table' information because we do not
684 filter system calls here. We let GDB do the logic for us. */
688 /* List of known LWPs, keyed by LWP PID. This speeds up the common
689 case of mapping a PID returned from the kernel to our corresponding
690 lwp_info data structure. */
691 static htab_t lwp_lwpid_htab
;
693 /* Calculate a hash from a lwp_info's LWP PID. */
696 lwp_info_hash (const void *ap
)
698 const struct lwp_info
*lp
= (struct lwp_info
*) ap
;
699 pid_t pid
= ptid_get_lwp (lp
->ptid
);
701 return iterative_hash_object (pid
, 0);
704 /* Equality function for the lwp_info hash table. Compares the LWP's
708 lwp_lwpid_htab_eq (const void *a
, const void *b
)
710 const struct lwp_info
*entry
= (const struct lwp_info
*) a
;
711 const struct lwp_info
*element
= (const struct lwp_info
*) b
;
713 return ptid_get_lwp (entry
->ptid
) == ptid_get_lwp (element
->ptid
);
716 /* Create the lwp_lwpid_htab hash table. */
719 lwp_lwpid_htab_create (void)
721 lwp_lwpid_htab
= htab_create (100, lwp_info_hash
, lwp_lwpid_htab_eq
, NULL
);
724 /* Add LP to the hash table. */
727 lwp_lwpid_htab_add_lwp (struct lwp_info
*lp
)
731 slot
= htab_find_slot (lwp_lwpid_htab
, lp
, INSERT
);
732 gdb_assert (slot
!= NULL
&& *slot
== NULL
);
736 /* Head of doubly-linked list of known LWPs. Sorted by reverse
737 creation order. This order is assumed in some cases. E.g.,
738 reaping status after killing alls lwps of a process: the leader LWP
739 must be reaped last. */
740 struct lwp_info
*lwp_list
;
742 /* Add LP to sorted-by-reverse-creation-order doubly-linked list. */
745 lwp_list_add (struct lwp_info
*lp
)
748 if (lwp_list
!= NULL
)
753 /* Remove LP from sorted-by-reverse-creation-order doubly-linked
757 lwp_list_remove (struct lwp_info
*lp
)
759 /* Remove from sorted-by-creation-order list. */
760 if (lp
->next
!= NULL
)
761 lp
->next
->prev
= lp
->prev
;
762 if (lp
->prev
!= NULL
)
763 lp
->prev
->next
= lp
->next
;
770 /* Original signal mask. */
771 static sigset_t normal_mask
;
773 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
774 _initialize_linux_nat. */
775 static sigset_t suspend_mask
;
777 /* Signals to block to make that sigsuspend work. */
778 static sigset_t blocked_mask
;
780 /* SIGCHLD action. */
781 struct sigaction sigchld_action
;
783 /* Block child signals (SIGCHLD and linux threads signals), and store
784 the previous mask in PREV_MASK. */
787 block_child_signals (sigset_t
*prev_mask
)
789 /* Make sure SIGCHLD is blocked. */
790 if (!sigismember (&blocked_mask
, SIGCHLD
))
791 sigaddset (&blocked_mask
, SIGCHLD
);
793 sigprocmask (SIG_BLOCK
, &blocked_mask
, prev_mask
);
796 /* Restore child signals mask, previously returned by
797 block_child_signals. */
800 restore_child_signals_mask (sigset_t
*prev_mask
)
802 sigprocmask (SIG_SETMASK
, prev_mask
, NULL
);
805 /* Mask of signals to pass directly to the inferior. */
806 static sigset_t pass_mask
;
808 /* Update signals to pass to the inferior. */
810 linux_nat_pass_signals (struct target_ops
*self
,
811 int numsigs
, unsigned char *pass_signals
)
815 sigemptyset (&pass_mask
);
817 for (signo
= 1; signo
< NSIG
; signo
++)
819 int target_signo
= gdb_signal_from_host (signo
);
820 if (target_signo
< numsigs
&& pass_signals
[target_signo
])
821 sigaddset (&pass_mask
, signo
);
827 /* Prototypes for local functions. */
828 static int stop_wait_callback (struct lwp_info
*lp
, void *data
);
829 static char *linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
);
830 static int resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
);
831 static int check_ptrace_stopped_lwp_gone (struct lwp_info
*lp
);
835 /* Destroy and free LP. */
838 lwp_free (struct lwp_info
*lp
)
840 xfree (lp
->arch_private
);
844 /* Traversal function for purge_lwp_list. */
847 lwp_lwpid_htab_remove_pid (void **slot
, void *info
)
849 struct lwp_info
*lp
= (struct lwp_info
*) *slot
;
850 int pid
= *(int *) info
;
852 if (ptid_get_pid (lp
->ptid
) == pid
)
854 htab_clear_slot (lwp_lwpid_htab
, slot
);
855 lwp_list_remove (lp
);
862 /* Remove all LWPs belong to PID from the lwp list. */
865 purge_lwp_list (int pid
)
867 htab_traverse_noresize (lwp_lwpid_htab
, lwp_lwpid_htab_remove_pid
, &pid
);
870 /* Add the LWP specified by PTID to the list. PTID is the first LWP
871 in the process. Return a pointer to the structure describing the
874 This differs from add_lwp in that we don't let the arch specific
875 bits know about this new thread. Current clients of this callback
876 take the opportunity to install watchpoints in the new thread, and
877 we shouldn't do that for the first thread. If we're spawning a
878 child ("run"), the thread executes the shell wrapper first, and we
879 shouldn't touch it until it execs the program we want to debug.
880 For "attach", it'd be okay to call the callback, but it's not
881 necessary, because watchpoints can't yet have been inserted into
884 static struct lwp_info
*
885 add_initial_lwp (ptid_t ptid
)
889 gdb_assert (ptid_lwp_p (ptid
));
891 lp
= XNEW (struct lwp_info
);
893 memset (lp
, 0, sizeof (struct lwp_info
));
895 lp
->last_resume_kind
= resume_continue
;
896 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
901 /* Add to sorted-by-reverse-creation-order list. */
904 /* Add to keyed-by-pid htab. */
905 lwp_lwpid_htab_add_lwp (lp
);
910 /* Add the LWP specified by PID to the list. Return a pointer to the
911 structure describing the new LWP. The LWP should already be
914 static struct lwp_info
*
915 add_lwp (ptid_t ptid
)
919 lp
= add_initial_lwp (ptid
);
921 /* Let the arch specific bits know about this new thread. Current
922 clients of this callback take the opportunity to install
923 watchpoints in the new thread. We don't do this for the first
924 thread though. See add_initial_lwp. */
925 if (linux_nat_new_thread
!= NULL
)
926 linux_nat_new_thread (lp
);
931 /* Remove the LWP specified by PID from the list. */
934 delete_lwp (ptid_t ptid
)
938 struct lwp_info dummy
;
941 slot
= htab_find_slot (lwp_lwpid_htab
, &dummy
, NO_INSERT
);
945 lp
= *(struct lwp_info
**) slot
;
946 gdb_assert (lp
!= NULL
);
948 htab_clear_slot (lwp_lwpid_htab
, slot
);
950 /* Remove from sorted-by-creation-order list. */
951 lwp_list_remove (lp
);
957 /* Return a pointer to the structure describing the LWP corresponding
958 to PID. If no corresponding LWP could be found, return NULL. */
960 static struct lwp_info
*
961 find_lwp_pid (ptid_t ptid
)
965 struct lwp_info dummy
;
967 if (ptid_lwp_p (ptid
))
968 lwp
= ptid_get_lwp (ptid
);
970 lwp
= ptid_get_pid (ptid
);
972 dummy
.ptid
= ptid_build (0, lwp
, 0);
973 lp
= (struct lwp_info
*) htab_find (lwp_lwpid_htab
, &dummy
);
977 /* See nat/linux-nat.h. */
980 iterate_over_lwps (ptid_t filter
,
981 iterate_over_lwps_ftype callback
,
984 struct lwp_info
*lp
, *lpnext
;
986 for (lp
= lwp_list
; lp
; lp
= lpnext
)
990 if (ptid_match (lp
->ptid
, filter
))
992 if ((*callback
) (lp
, data
) != 0)
1000 /* Update our internal state when changing from one checkpoint to
1001 another indicated by NEW_PTID. We can only switch single-threaded
1002 applications, so we only create one new LWP, and the previous list
1006 linux_nat_switch_fork (ptid_t new_ptid
)
1008 struct lwp_info
*lp
;
1010 purge_lwp_list (ptid_get_pid (inferior_ptid
));
1012 lp
= add_lwp (new_ptid
);
1015 /* This changes the thread's ptid while preserving the gdb thread
1016 num. Also changes the inferior pid, while preserving the
1018 thread_change_ptid (inferior_ptid
, new_ptid
);
1020 /* We've just told GDB core that the thread changed target id, but,
1021 in fact, it really is a different thread, with different register
1023 registers_changed ();
1026 /* Handle the exit of a single thread LP. */
1029 exit_lwp (struct lwp_info
*lp
)
1031 struct thread_info
*th
= find_thread_ptid (lp
->ptid
);
1035 if (print_thread_events
)
1036 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp
->ptid
));
1038 delete_thread (lp
->ptid
);
1041 delete_lwp (lp
->ptid
);
1044 /* Wait for the LWP specified by LP, which we have just attached to.
1045 Returns a wait status for that LWP, to cache. */
1048 linux_nat_post_attach_wait (ptid_t ptid
, int first
, int *signalled
)
1050 pid_t new_pid
, pid
= ptid_get_lwp (ptid
);
1053 if (linux_proc_pid_is_stopped (pid
))
1055 if (debug_linux_nat
)
1056 fprintf_unfiltered (gdb_stdlog
,
1057 "LNPAW: Attaching to a stopped process\n");
1059 /* The process is definitely stopped. It is in a job control
1060 stop, unless the kernel predates the TASK_STOPPED /
1061 TASK_TRACED distinction, in which case it might be in a
1062 ptrace stop. Make sure it is in a ptrace stop; from there we
1063 can kill it, signal it, et cetera.
1065 First make sure there is a pending SIGSTOP. Since we are
1066 already attached, the process can not transition from stopped
1067 to running without a PTRACE_CONT; so we know this signal will
1068 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1069 probably already in the queue (unless this kernel is old
1070 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1071 is not an RT signal, it can only be queued once. */
1072 kill_lwp (pid
, SIGSTOP
);
1074 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1075 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1076 ptrace (PTRACE_CONT
, pid
, 0, 0);
1079 /* Make sure the initial process is stopped. The user-level threads
1080 layer might want to poke around in the inferior, and that won't
1081 work if things haven't stabilized yet. */
1082 new_pid
= my_waitpid (pid
, &status
, __WALL
);
1083 gdb_assert (pid
== new_pid
);
1085 if (!WIFSTOPPED (status
))
1087 /* The pid we tried to attach has apparently just exited. */
1088 if (debug_linux_nat
)
1089 fprintf_unfiltered (gdb_stdlog
, "LNPAW: Failed to stop %d: %s",
1090 pid
, status_to_str (status
));
1094 if (WSTOPSIG (status
) != SIGSTOP
)
1097 if (debug_linux_nat
)
1098 fprintf_unfiltered (gdb_stdlog
,
1099 "LNPAW: Received %s after attaching\n",
1100 status_to_str (status
));
1107 linux_nat_create_inferior (struct target_ops
*ops
,
1108 char *exec_file
, char *allargs
, char **env
,
1111 struct cleanup
*restore_personality
1112 = maybe_disable_address_space_randomization (disable_randomization
);
1114 /* The fork_child mechanism is synchronous and calls target_wait, so
1115 we have to mask the async mode. */
1117 /* Make sure we report all signals during startup. */
1118 linux_nat_pass_signals (ops
, 0, NULL
);
1120 linux_ops
->to_create_inferior (ops
, exec_file
, allargs
, env
, from_tty
);
1122 do_cleanups (restore_personality
);
1125 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
1126 already attached. Returns true if a new LWP is found, false
1130 attach_proc_task_lwp_callback (ptid_t ptid
)
1132 struct lwp_info
*lp
;
1134 /* Ignore LWPs we're already attached to. */
1135 lp
= find_lwp_pid (ptid
);
1138 int lwpid
= ptid_get_lwp (ptid
);
1140 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) < 0)
1144 /* Be quiet if we simply raced with the thread exiting.
1145 EPERM is returned if the thread's task still exists, and
1146 is marked as exited or zombie, as well as other
1147 conditions, so in that case, confirm the status in
1148 /proc/PID/status. */
1150 || (err
== EPERM
&& linux_proc_pid_is_gone (lwpid
)))
1152 if (debug_linux_nat
)
1154 fprintf_unfiltered (gdb_stdlog
,
1155 "Cannot attach to lwp %d: "
1156 "thread is gone (%d: %s)\n",
1157 lwpid
, err
, safe_strerror (err
));
1162 warning (_("Cannot attach to lwp %d: %s"),
1164 linux_ptrace_attach_fail_reason_string (ptid
,
1170 if (debug_linux_nat
)
1171 fprintf_unfiltered (gdb_stdlog
,
1172 "PTRACE_ATTACH %s, 0, 0 (OK)\n",
1173 target_pid_to_str (ptid
));
1175 lp
= add_lwp (ptid
);
1177 /* The next time we wait for this LWP we'll see a SIGSTOP as
1178 PTRACE_ATTACH brings it to a halt. */
1181 /* We need to wait for a stop before being able to make the
1182 next ptrace call on this LWP. */
1183 lp
->must_set_ptrace_flags
= 1;
1185 /* So that wait collects the SIGSTOP. */
1188 /* Also add the LWP to gdb's thread list, in case a
1189 matching libthread_db is not found (or the process uses
1191 add_thread (lp
->ptid
);
1192 set_running (lp
->ptid
, 1);
1193 set_executing (lp
->ptid
, 1);
1202 linux_nat_attach (struct target_ops
*ops
, const char *args
, int from_tty
)
1204 struct lwp_info
*lp
;
1208 /* Make sure we report all signals during attach. */
1209 linux_nat_pass_signals (ops
, 0, NULL
);
1213 linux_ops
->to_attach (ops
, args
, from_tty
);
1215 CATCH (ex
, RETURN_MASK_ERROR
)
1217 pid_t pid
= parse_pid_to_attach (args
);
1218 struct buffer buffer
;
1219 char *message
, *buffer_s
;
1221 message
= xstrdup (ex
.message
);
1222 make_cleanup (xfree
, message
);
1224 buffer_init (&buffer
);
1225 linux_ptrace_attach_fail_reason (pid
, &buffer
);
1227 buffer_grow_str0 (&buffer
, "");
1228 buffer_s
= buffer_finish (&buffer
);
1229 make_cleanup (xfree
, buffer_s
);
1231 if (*buffer_s
!= '\0')
1232 throw_error (ex
.error
, "warning: %s\n%s", buffer_s
, message
);
1234 throw_error (ex
.error
, "%s", message
);
1238 /* The ptrace base target adds the main thread with (pid,0,0)
1239 format. Decorate it with lwp info. */
1240 ptid
= ptid_build (ptid_get_pid (inferior_ptid
),
1241 ptid_get_pid (inferior_ptid
),
1243 thread_change_ptid (inferior_ptid
, ptid
);
1245 /* Add the initial process as the first LWP to the list. */
1246 lp
= add_initial_lwp (ptid
);
1248 status
= linux_nat_post_attach_wait (lp
->ptid
, 1, &lp
->signalled
);
1249 if (!WIFSTOPPED (status
))
1251 if (WIFEXITED (status
))
1253 int exit_code
= WEXITSTATUS (status
);
1255 target_terminal_ours ();
1256 target_mourn_inferior (inferior_ptid
);
1258 error (_("Unable to attach: program exited normally."));
1260 error (_("Unable to attach: program exited with code %d."),
1263 else if (WIFSIGNALED (status
))
1265 enum gdb_signal signo
;
1267 target_terminal_ours ();
1268 target_mourn_inferior (inferior_ptid
);
1270 signo
= gdb_signal_from_host (WTERMSIG (status
));
1271 error (_("Unable to attach: program terminated with signal "
1273 gdb_signal_to_name (signo
),
1274 gdb_signal_to_string (signo
));
1277 internal_error (__FILE__
, __LINE__
,
1278 _("unexpected status %d for PID %ld"),
1279 status
, (long) ptid_get_lwp (ptid
));
1284 /* Save the wait status to report later. */
1286 if (debug_linux_nat
)
1287 fprintf_unfiltered (gdb_stdlog
,
1288 "LNA: waitpid %ld, saving status %s\n",
1289 (long) ptid_get_pid (lp
->ptid
), status_to_str (status
));
1291 lp
->status
= status
;
1293 /* We must attach to every LWP. If /proc is mounted, use that to
1294 find them now. The inferior may be using raw clone instead of
1295 using pthreads. But even if it is using pthreads, thread_db
1296 walks structures in the inferior's address space to find the list
1297 of threads/LWPs, and those structures may well be corrupted.
1298 Note that once thread_db is loaded, we'll still use it to list
1299 threads and associate pthread info with each LWP. */
1300 linux_proc_attach_tgid_threads (ptid_get_pid (lp
->ptid
),
1301 attach_proc_task_lwp_callback
);
1303 if (target_can_async_p ())
1307 /* Get pending signal of THREAD as a host signal number, for detaching
1308 purposes. This is the signal the thread last stopped for, which we
1309 need to deliver to the thread when detaching, otherwise, it'd be
1313 get_detach_signal (struct lwp_info
*lp
)
1315 enum gdb_signal signo
= GDB_SIGNAL_0
;
1317 /* If we paused threads momentarily, we may have stored pending
1318 events in lp->status or lp->waitstatus (see stop_wait_callback),
1319 and GDB core hasn't seen any signal for those threads.
1320 Otherwise, the last signal reported to the core is found in the
1321 thread object's stop_signal.
1323 There's a corner case that isn't handled here at present. Only
1324 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1325 stop_signal make sense as a real signal to pass to the inferior.
1326 Some catchpoint related events, like
1327 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1328 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1329 those traps are debug API (ptrace in our case) related and
1330 induced; the inferior wouldn't see them if it wasn't being
1331 traced. Hence, we should never pass them to the inferior, even
1332 when set to pass state. Since this corner case isn't handled by
1333 infrun.c when proceeding with a signal, for consistency, neither
1334 do we handle it here (or elsewhere in the file we check for
1335 signal pass state). Normally SIGTRAP isn't set to pass state, so
1336 this is really a corner case. */
1338 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
1339 signo
= GDB_SIGNAL_0
; /* a pending ptrace event, not a real signal. */
1340 else if (lp
->status
)
1341 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1342 else if (target_is_non_stop_p () && !is_executing (lp
->ptid
))
1344 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1346 if (tp
->suspend
.waitstatus_pending_p
)
1347 signo
= tp
->suspend
.waitstatus
.value
.sig
;
1349 signo
= tp
->suspend
.stop_signal
;
1351 else if (!target_is_non_stop_p ())
1353 struct target_waitstatus last
;
1356 get_last_target_status (&last_ptid
, &last
);
1358 if (ptid_get_lwp (lp
->ptid
) == ptid_get_lwp (last_ptid
))
1360 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1362 signo
= tp
->suspend
.stop_signal
;
1366 if (signo
== GDB_SIGNAL_0
)
1368 if (debug_linux_nat
)
1369 fprintf_unfiltered (gdb_stdlog
,
1370 "GPT: lwp %s has no pending signal\n",
1371 target_pid_to_str (lp
->ptid
));
1373 else if (!signal_pass_state (signo
))
1375 if (debug_linux_nat
)
1376 fprintf_unfiltered (gdb_stdlog
,
1377 "GPT: lwp %s had signal %s, "
1378 "but it is in no pass state\n",
1379 target_pid_to_str (lp
->ptid
),
1380 gdb_signal_to_string (signo
));
1384 if (debug_linux_nat
)
1385 fprintf_unfiltered (gdb_stdlog
,
1386 "GPT: lwp %s has pending signal %s\n",
1387 target_pid_to_str (lp
->ptid
),
1388 gdb_signal_to_string (signo
));
1390 return gdb_signal_to_host (signo
);
1396 /* Detach from LP. If SIGNO_P is non-NULL, then it points to the
1397 signal number that should be passed to the LWP when detaching.
1398 Otherwise pass any pending signal the LWP may have, if any. */
1401 detach_one_lwp (struct lwp_info
*lp
, int *signo_p
)
1403 int lwpid
= ptid_get_lwp (lp
->ptid
);
1406 gdb_assert (lp
->status
== 0 || WIFSTOPPED (lp
->status
));
1408 if (debug_linux_nat
&& lp
->status
)
1409 fprintf_unfiltered (gdb_stdlog
, "DC: Pending %s for %s on detach.\n",
1410 strsignal (WSTOPSIG (lp
->status
)),
1411 target_pid_to_str (lp
->ptid
));
1413 /* If there is a pending SIGSTOP, get rid of it. */
1416 if (debug_linux_nat
)
1417 fprintf_unfiltered (gdb_stdlog
,
1418 "DC: Sending SIGCONT to %s\n",
1419 target_pid_to_str (lp
->ptid
));
1421 kill_lwp (lwpid
, SIGCONT
);
1425 if (signo_p
== NULL
)
1427 /* Pass on any pending signal for this LWP. */
1428 signo
= get_detach_signal (lp
);
1433 /* Preparing to resume may try to write registers, and fail if the
1434 lwp is zombie. If that happens, ignore the error. We'll handle
1435 it below, when detach fails with ESRCH. */
1438 if (linux_nat_prepare_to_resume
!= NULL
)
1439 linux_nat_prepare_to_resume (lp
);
1441 CATCH (ex
, RETURN_MASK_ERROR
)
1443 if (!check_ptrace_stopped_lwp_gone (lp
))
1444 throw_exception (ex
);
1448 if (ptrace (PTRACE_DETACH
, lwpid
, 0, signo
) < 0)
1450 int save_errno
= errno
;
1452 /* We know the thread exists, so ESRCH must mean the lwp is
1453 zombie. This can happen if one of the already-detached
1454 threads exits the whole thread group. In that case we're
1455 still attached, and must reap the lwp. */
1456 if (save_errno
== ESRCH
)
1460 ret
= my_waitpid (lwpid
, &status
, __WALL
);
1463 warning (_("Couldn't reap LWP %d while detaching: %s"),
1464 lwpid
, strerror (errno
));
1466 else if (!WIFEXITED (status
) && !WIFSIGNALED (status
))
1468 warning (_("Reaping LWP %d while detaching "
1469 "returned unexpected status 0x%x"),
1475 error (_("Can't detach %s: %s"), target_pid_to_str (lp
->ptid
),
1476 safe_strerror (save_errno
));
1479 else if (debug_linux_nat
)
1481 fprintf_unfiltered (gdb_stdlog
,
1482 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1483 target_pid_to_str (lp
->ptid
),
1487 delete_lwp (lp
->ptid
);
1491 detach_callback (struct lwp_info
*lp
, void *data
)
1493 /* We don't actually detach from the thread group leader just yet.
1494 If the thread group exits, we must reap the zombie clone lwps
1495 before we're able to reap the leader. */
1496 if (ptid_get_lwp (lp
->ptid
) != ptid_get_pid (lp
->ptid
))
1497 detach_one_lwp (lp
, NULL
);
1502 linux_nat_detach (struct target_ops
*ops
, const char *args
, int from_tty
)
1505 struct lwp_info
*main_lwp
;
1507 pid
= ptid_get_pid (inferior_ptid
);
1509 /* Don't unregister from the event loop, as there may be other
1510 inferiors running. */
1512 /* Stop all threads before detaching. ptrace requires that the
1513 thread is stopped to sucessfully detach. */
1514 iterate_over_lwps (pid_to_ptid (pid
), stop_callback
, NULL
);
1515 /* ... and wait until all of them have reported back that
1516 they're no longer running. */
1517 iterate_over_lwps (pid_to_ptid (pid
), stop_wait_callback
, NULL
);
1519 iterate_over_lwps (pid_to_ptid (pid
), detach_callback
, NULL
);
1521 /* Only the initial process should be left right now. */
1522 gdb_assert (num_lwps (ptid_get_pid (inferior_ptid
)) == 1);
1524 main_lwp
= find_lwp_pid (pid_to_ptid (pid
));
1526 if (forks_exist_p ())
1528 /* Multi-fork case. The current inferior_ptid is being detached
1529 from, but there are other viable forks to debug. Detach from
1530 the current fork, and context-switch to the first
1532 linux_fork_detach (args
, from_tty
);
1538 target_announce_detach (from_tty
);
1540 /* Pass on any pending signal for the last LWP, unless the user
1541 requested detaching with a different signal (most likely 0,
1542 meaning, discard the signal). */
1544 signo
= atoi (args
);
1546 signo
= get_detach_signal (main_lwp
);
1548 detach_one_lwp (main_lwp
, &signo
);
1550 inf_ptrace_detach_success (ops
);
1552 delete_lwp (main_lwp
->ptid
);
1555 /* Resume execution of the inferior process. If STEP is nonzero,
1556 single-step it. If SIGNAL is nonzero, give it that signal. */
1559 linux_resume_one_lwp_throw (struct lwp_info
*lp
, int step
,
1560 enum gdb_signal signo
)
1564 /* stop_pc doubles as the PC the LWP had when it was last resumed.
1565 We only presently need that if the LWP is stepped though (to
1566 handle the case of stepping a breakpoint instruction). */
1569 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
1571 lp
->stop_pc
= regcache_read_pc (regcache
);
1576 if (linux_nat_prepare_to_resume
!= NULL
)
1577 linux_nat_prepare_to_resume (lp
);
1578 linux_ops
->to_resume (linux_ops
, lp
->ptid
, step
, signo
);
1580 /* Successfully resumed. Clear state that no longer makes sense,
1581 and mark the LWP as running. Must not do this before resuming
1582 otherwise if that fails other code will be confused. E.g., we'd
1583 later try to stop the LWP and hang forever waiting for a stop
1584 status. Note that we must not throw after this is cleared,
1585 otherwise handle_zombie_lwp_error would get confused. */
1588 lp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
1589 registers_changed_ptid (lp
->ptid
);
1592 /* Called when we try to resume a stopped LWP and that errors out. If
1593 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
1594 or about to become), discard the error, clear any pending status
1595 the LWP may have, and return true (we'll collect the exit status
1596 soon enough). Otherwise, return false. */
1599 check_ptrace_stopped_lwp_gone (struct lwp_info
*lp
)
1601 /* If we get an error after resuming the LWP successfully, we'd
1602 confuse !T state for the LWP being gone. */
1603 gdb_assert (lp
->stopped
);
1605 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
1606 because even if ptrace failed with ESRCH, the tracee may be "not
1607 yet fully dead", but already refusing ptrace requests. In that
1608 case the tracee has 'R (Running)' state for a little bit
1609 (observed in Linux 3.18). See also the note on ESRCH in the
1610 ptrace(2) man page. Instead, check whether the LWP has any state
1611 other than ptrace-stopped. */
1613 /* Don't assume anything if /proc/PID/status can't be read. */
1614 if (linux_proc_pid_is_trace_stopped_nowarn (ptid_get_lwp (lp
->ptid
)) == 0)
1616 lp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
1618 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
1624 /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
1625 disappears while we try to resume it. */
1628 linux_resume_one_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1632 linux_resume_one_lwp_throw (lp
, step
, signo
);
1634 CATCH (ex
, RETURN_MASK_ERROR
)
1636 if (!check_ptrace_stopped_lwp_gone (lp
))
1637 throw_exception (ex
);
1645 resume_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1649 struct inferior
*inf
= find_inferior_ptid (lp
->ptid
);
1651 if (inf
->vfork_child
!= NULL
)
1653 if (debug_linux_nat
)
1654 fprintf_unfiltered (gdb_stdlog
,
1655 "RC: Not resuming %s (vfork parent)\n",
1656 target_pid_to_str (lp
->ptid
));
1658 else if (!lwp_status_pending_p (lp
))
1660 if (debug_linux_nat
)
1661 fprintf_unfiltered (gdb_stdlog
,
1662 "RC: Resuming sibling %s, %s, %s\n",
1663 target_pid_to_str (lp
->ptid
),
1664 (signo
!= GDB_SIGNAL_0
1665 ? strsignal (gdb_signal_to_host (signo
))
1667 step
? "step" : "resume");
1669 linux_resume_one_lwp (lp
, step
, signo
);
1673 if (debug_linux_nat
)
1674 fprintf_unfiltered (gdb_stdlog
,
1675 "RC: Not resuming sibling %s (has pending)\n",
1676 target_pid_to_str (lp
->ptid
));
1681 if (debug_linux_nat
)
1682 fprintf_unfiltered (gdb_stdlog
,
1683 "RC: Not resuming sibling %s (not stopped)\n",
1684 target_pid_to_str (lp
->ptid
));
1688 /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing.
1689 Resume LWP with the last stop signal, if it is in pass state. */
1692 linux_nat_resume_callback (struct lwp_info
*lp
, void *except
)
1694 enum gdb_signal signo
= GDB_SIGNAL_0
;
1701 struct thread_info
*thread
;
1703 thread
= find_thread_ptid (lp
->ptid
);
1706 signo
= thread
->suspend
.stop_signal
;
1707 thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
1711 resume_lwp (lp
, 0, signo
);
1716 resume_clear_callback (struct lwp_info
*lp
, void *data
)
1719 lp
->last_resume_kind
= resume_stop
;
1724 resume_set_callback (struct lwp_info
*lp
, void *data
)
1727 lp
->last_resume_kind
= resume_continue
;
1732 linux_nat_resume (struct target_ops
*ops
,
1733 ptid_t ptid
, int step
, enum gdb_signal signo
)
1735 struct lwp_info
*lp
;
1738 if (debug_linux_nat
)
1739 fprintf_unfiltered (gdb_stdlog
,
1740 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1741 step
? "step" : "resume",
1742 target_pid_to_str (ptid
),
1743 (signo
!= GDB_SIGNAL_0
1744 ? strsignal (gdb_signal_to_host (signo
)) : "0"),
1745 target_pid_to_str (inferior_ptid
));
1747 /* A specific PTID means `step only this process id'. */
1748 resume_many
= (ptid_equal (minus_one_ptid
, ptid
)
1749 || ptid_is_pid (ptid
));
1751 /* Mark the lwps we're resuming as resumed. */
1752 iterate_over_lwps (ptid
, resume_set_callback
, NULL
);
1754 /* See if it's the current inferior that should be handled
1757 lp
= find_lwp_pid (inferior_ptid
);
1759 lp
= find_lwp_pid (ptid
);
1760 gdb_assert (lp
!= NULL
);
1762 /* Remember if we're stepping. */
1763 lp
->last_resume_kind
= step
? resume_step
: resume_continue
;
1765 /* If we have a pending wait status for this thread, there is no
1766 point in resuming the process. But first make sure that
1767 linux_nat_wait won't preemptively handle the event - we
1768 should never take this short-circuit if we are going to
1769 leave LP running, since we have skipped resuming all the
1770 other threads. This bit of code needs to be synchronized
1771 with linux_nat_wait. */
1773 if (lp
->status
&& WIFSTOPPED (lp
->status
))
1776 && WSTOPSIG (lp
->status
)
1777 && sigismember (&pass_mask
, WSTOPSIG (lp
->status
)))
1779 if (debug_linux_nat
)
1780 fprintf_unfiltered (gdb_stdlog
,
1781 "LLR: Not short circuiting for ignored "
1782 "status 0x%x\n", lp
->status
);
1784 /* FIXME: What should we do if we are supposed to continue
1785 this thread with a signal? */
1786 gdb_assert (signo
== GDB_SIGNAL_0
);
1787 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1792 if (lwp_status_pending_p (lp
))
1794 /* FIXME: What should we do if we are supposed to continue
1795 this thread with a signal? */
1796 gdb_assert (signo
== GDB_SIGNAL_0
);
1798 if (debug_linux_nat
)
1799 fprintf_unfiltered (gdb_stdlog
,
1800 "LLR: Short circuiting for status 0x%x\n",
1803 if (target_can_async_p ())
1806 /* Tell the event loop we have something to process. */
1813 iterate_over_lwps (ptid
, linux_nat_resume_callback
, lp
);
1815 if (debug_linux_nat
)
1816 fprintf_unfiltered (gdb_stdlog
,
1817 "LLR: %s %s, %s (resume event thread)\n",
1818 step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1819 target_pid_to_str (lp
->ptid
),
1820 (signo
!= GDB_SIGNAL_0
1821 ? strsignal (gdb_signal_to_host (signo
)) : "0"));
1823 linux_resume_one_lwp (lp
, step
, signo
);
1825 if (target_can_async_p ())
1829 /* Send a signal to an LWP. */
1832 kill_lwp (int lwpid
, int signo
)
1837 ret
= syscall (__NR_tkill
, lwpid
, signo
);
1838 if (errno
== ENOSYS
)
1840 /* If tkill fails, then we are not using nptl threads, a
1841 configuration we no longer support. */
1842 perror_with_name (("tkill"));
1847 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1848 event, check if the core is interested in it: if not, ignore the
1849 event, and keep waiting; otherwise, we need to toggle the LWP's
1850 syscall entry/exit status, since the ptrace event itself doesn't
1851 indicate it, and report the trap to higher layers. */
1854 linux_handle_syscall_trap (struct lwp_info
*lp
, int stopping
)
1856 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1857 struct gdbarch
*gdbarch
= target_thread_architecture (lp
->ptid
);
1858 int syscall_number
= (int) gdbarch_get_syscall_number (gdbarch
, lp
->ptid
);
1862 /* If we're stopping threads, there's a SIGSTOP pending, which
1863 makes it so that the LWP reports an immediate syscall return,
1864 followed by the SIGSTOP. Skip seeing that "return" using
1865 PTRACE_CONT directly, and let stop_wait_callback collect the
1866 SIGSTOP. Later when the thread is resumed, a new syscall
1867 entry event. If we didn't do this (and returned 0), we'd
1868 leave a syscall entry pending, and our caller, by using
1869 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1870 itself. Later, when the user re-resumes this LWP, we'd see
1871 another syscall entry event and we'd mistake it for a return.
1873 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1874 (leaving immediately with LWP->signalled set, without issuing
1875 a PTRACE_CONT), it would still be problematic to leave this
1876 syscall enter pending, as later when the thread is resumed,
1877 it would then see the same syscall exit mentioned above,
1878 followed by the delayed SIGSTOP, while the syscall didn't
1879 actually get to execute. It seems it would be even more
1880 confusing to the user. */
1882 if (debug_linux_nat
)
1883 fprintf_unfiltered (gdb_stdlog
,
1884 "LHST: ignoring syscall %d "
1885 "for LWP %ld (stopping threads), "
1886 "resuming with PTRACE_CONT for SIGSTOP\n",
1888 ptid_get_lwp (lp
->ptid
));
1890 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1891 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
1896 /* Always update the entry/return state, even if this particular
1897 syscall isn't interesting to the core now. In async mode,
1898 the user could install a new catchpoint for this syscall
1899 between syscall enter/return, and we'll need to know to
1900 report a syscall return if that happens. */
1901 lp
->syscall_state
= (lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1902 ? TARGET_WAITKIND_SYSCALL_RETURN
1903 : TARGET_WAITKIND_SYSCALL_ENTRY
);
1905 if (catch_syscall_enabled ())
1907 if (catching_syscall_number (syscall_number
))
1909 /* Alright, an event to report. */
1910 ourstatus
->kind
= lp
->syscall_state
;
1911 ourstatus
->value
.syscall_number
= syscall_number
;
1913 if (debug_linux_nat
)
1914 fprintf_unfiltered (gdb_stdlog
,
1915 "LHST: stopping for %s of syscall %d"
1918 == TARGET_WAITKIND_SYSCALL_ENTRY
1919 ? "entry" : "return",
1921 ptid_get_lwp (lp
->ptid
));
1925 if (debug_linux_nat
)
1926 fprintf_unfiltered (gdb_stdlog
,
1927 "LHST: ignoring %s of syscall %d "
1929 lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1930 ? "entry" : "return",
1932 ptid_get_lwp (lp
->ptid
));
1936 /* If we had been syscall tracing, and hence used PT_SYSCALL
1937 before on this LWP, it could happen that the user removes all
1938 syscall catchpoints before we get to process this event.
1939 There are two noteworthy issues here:
1941 - When stopped at a syscall entry event, resuming with
1942 PT_STEP still resumes executing the syscall and reports a
1945 - Only PT_SYSCALL catches syscall enters. If we last
1946 single-stepped this thread, then this event can't be a
1947 syscall enter. If we last single-stepped this thread, this
1948 has to be a syscall exit.
1950 The points above mean that the next resume, be it PT_STEP or
1951 PT_CONTINUE, can not trigger a syscall trace event. */
1952 if (debug_linux_nat
)
1953 fprintf_unfiltered (gdb_stdlog
,
1954 "LHST: caught syscall event "
1955 "with no syscall catchpoints."
1956 " %d for LWP %ld, ignoring\n",
1958 ptid_get_lwp (lp
->ptid
));
1959 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1962 /* The core isn't interested in this event. For efficiency, avoid
1963 stopping all threads only to have the core resume them all again.
1964 Since we're not stopping threads, if we're still syscall tracing
1965 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1966 subsequent syscall. Simply resume using the inf-ptrace layer,
1967 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1969 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
1973 /* Handle a GNU/Linux extended wait response. If we see a clone
1974 event, we need to add the new LWP to our list (and not report the
1975 trap to higher layers). This function returns non-zero if the
1976 event should be ignored and we should wait again. If STOPPING is
1977 true, the new LWP remains stopped, otherwise it is continued. */
1980 linux_handle_extended_wait (struct lwp_info
*lp
, int status
)
1982 int pid
= ptid_get_lwp (lp
->ptid
);
1983 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1984 int event
= linux_ptrace_get_extended_event (status
);
1986 /* All extended events we currently use are mid-syscall. Only
1987 PTRACE_EVENT_STOP is delivered more like a signal-stop, but
1988 you have to be using PTRACE_SEIZE to get that. */
1989 lp
->syscall_state
= TARGET_WAITKIND_SYSCALL_ENTRY
;
1991 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
1992 || event
== PTRACE_EVENT_CLONE
)
1994 unsigned long new_pid
;
1997 ptrace (PTRACE_GETEVENTMSG
, pid
, 0, &new_pid
);
1999 /* If we haven't already seen the new PID stop, wait for it now. */
2000 if (! pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
2002 /* The new child has a pending SIGSTOP. We can't affect it until it
2003 hits the SIGSTOP, but we're already attached. */
2004 ret
= my_waitpid (new_pid
, &status
, __WALL
);
2006 perror_with_name (_("waiting for new child"));
2007 else if (ret
!= new_pid
)
2008 internal_error (__FILE__
, __LINE__
,
2009 _("wait returned unexpected PID %d"), ret
);
2010 else if (!WIFSTOPPED (status
))
2011 internal_error (__FILE__
, __LINE__
,
2012 _("wait returned unexpected status 0x%x"), status
);
2015 ourstatus
->value
.related_pid
= ptid_build (new_pid
, new_pid
, 0);
2017 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
)
2019 /* The arch-specific native code may need to know about new
2020 forks even if those end up never mapped to an
2022 if (linux_nat_new_fork
!= NULL
)
2023 linux_nat_new_fork (lp
, new_pid
);
2026 if (event
== PTRACE_EVENT_FORK
2027 && linux_fork_checkpointing_p (ptid_get_pid (lp
->ptid
)))
2029 /* Handle checkpointing by linux-fork.c here as a special
2030 case. We don't want the follow-fork-mode or 'catch fork'
2031 to interfere with this. */
2033 /* This won't actually modify the breakpoint list, but will
2034 physically remove the breakpoints from the child. */
2035 detach_breakpoints (ptid_build (new_pid
, new_pid
, 0));
2037 /* Retain child fork in ptrace (stopped) state. */
2038 if (!find_fork_pid (new_pid
))
2041 /* Report as spurious, so that infrun doesn't want to follow
2042 this fork. We're actually doing an infcall in
2044 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
2046 /* Report the stop to the core. */
2050 if (event
== PTRACE_EVENT_FORK
)
2051 ourstatus
->kind
= TARGET_WAITKIND_FORKED
;
2052 else if (event
== PTRACE_EVENT_VFORK
)
2053 ourstatus
->kind
= TARGET_WAITKIND_VFORKED
;
2054 else if (event
== PTRACE_EVENT_CLONE
)
2056 struct lwp_info
*new_lp
;
2058 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2060 if (debug_linux_nat
)
2061 fprintf_unfiltered (gdb_stdlog
,
2062 "LHEW: Got clone event "
2063 "from LWP %d, new child is LWP %ld\n",
2066 new_lp
= add_lwp (ptid_build (ptid_get_pid (lp
->ptid
), new_pid
, 0));
2067 new_lp
->stopped
= 1;
2068 new_lp
->resumed
= 1;
2070 /* If the thread_db layer is active, let it record the user
2071 level thread id and status, and add the thread to GDB's
2073 if (!thread_db_notice_clone (lp
->ptid
, new_lp
->ptid
))
2075 /* The process is not using thread_db. Add the LWP to
2077 target_post_attach (ptid_get_lwp (new_lp
->ptid
));
2078 add_thread (new_lp
->ptid
);
2081 /* Even if we're stopping the thread for some reason
2082 internal to this module, from the perspective of infrun
2083 and the user/frontend, this new thread is running until
2084 it next reports a stop. */
2085 set_running (new_lp
->ptid
, 1);
2086 set_executing (new_lp
->ptid
, 1);
2088 if (WSTOPSIG (status
) != SIGSTOP
)
2090 /* This can happen if someone starts sending signals to
2091 the new thread before it gets a chance to run, which
2092 have a lower number than SIGSTOP (e.g. SIGUSR1).
2093 This is an unlikely case, and harder to handle for
2094 fork / vfork than for clone, so we do not try - but
2095 we handle it for clone events here. */
2097 new_lp
->signalled
= 1;
2099 /* We created NEW_LP so it cannot yet contain STATUS. */
2100 gdb_assert (new_lp
->status
== 0);
2102 /* Save the wait status to report later. */
2103 if (debug_linux_nat
)
2104 fprintf_unfiltered (gdb_stdlog
,
2105 "LHEW: waitpid of new LWP %ld, "
2106 "saving status %s\n",
2107 (long) ptid_get_lwp (new_lp
->ptid
),
2108 status_to_str (status
));
2109 new_lp
->status
= status
;
2111 else if (report_thread_events
)
2113 new_lp
->waitstatus
.kind
= TARGET_WAITKIND_THREAD_CREATED
;
2114 new_lp
->status
= status
;
2123 if (event
== PTRACE_EVENT_EXEC
)
2125 if (debug_linux_nat
)
2126 fprintf_unfiltered (gdb_stdlog
,
2127 "LHEW: Got exec event from LWP %ld\n",
2128 ptid_get_lwp (lp
->ptid
));
2130 ourstatus
->kind
= TARGET_WAITKIND_EXECD
;
2131 ourstatus
->value
.execd_pathname
2132 = xstrdup (linux_child_pid_to_exec_file (NULL
, pid
));
2134 /* The thread that execed must have been resumed, but, when a
2135 thread execs, it changes its tid to the tgid, and the old
2136 tgid thread might have not been resumed. */
2141 if (event
== PTRACE_EVENT_VFORK_DONE
)
2143 if (current_inferior ()->waiting_for_vfork_done
)
2145 if (debug_linux_nat
)
2146 fprintf_unfiltered (gdb_stdlog
,
2147 "LHEW: Got expected PTRACE_EVENT_"
2148 "VFORK_DONE from LWP %ld: stopping\n",
2149 ptid_get_lwp (lp
->ptid
));
2151 ourstatus
->kind
= TARGET_WAITKIND_VFORK_DONE
;
2155 if (debug_linux_nat
)
2156 fprintf_unfiltered (gdb_stdlog
,
2157 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2158 "from LWP %ld: ignoring\n",
2159 ptid_get_lwp (lp
->ptid
));
2163 internal_error (__FILE__
, __LINE__
,
2164 _("unknown ptrace event %d"), event
);
2167 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2171 wait_lwp (struct lwp_info
*lp
)
2175 int thread_dead
= 0;
2178 gdb_assert (!lp
->stopped
);
2179 gdb_assert (lp
->status
== 0);
2181 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2182 block_child_signals (&prev_mask
);
2186 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), &status
, __WALL
| WNOHANG
);
2187 if (pid
== -1 && errno
== ECHILD
)
2189 /* The thread has previously exited. We need to delete it
2190 now because if this was a non-leader thread execing, we
2191 won't get an exit event. See comments on exec events at
2192 the top of the file. */
2194 if (debug_linux_nat
)
2195 fprintf_unfiltered (gdb_stdlog
, "WL: %s vanished.\n",
2196 target_pid_to_str (lp
->ptid
));
2201 /* Bugs 10970, 12702.
2202 Thread group leader may have exited in which case we'll lock up in
2203 waitpid if there are other threads, even if they are all zombies too.
2204 Basically, we're not supposed to use waitpid this way.
2205 tkill(pid,0) cannot be used here as it gets ESRCH for both
2206 for zombie and running processes.
2208 As a workaround, check if we're waiting for the thread group leader and
2209 if it's a zombie, and avoid calling waitpid if it is.
2211 This is racy, what if the tgl becomes a zombie right after we check?
2212 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2213 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2215 if (ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
)
2216 && linux_proc_pid_is_zombie (ptid_get_lwp (lp
->ptid
)))
2219 if (debug_linux_nat
)
2220 fprintf_unfiltered (gdb_stdlog
,
2221 "WL: Thread group leader %s vanished.\n",
2222 target_pid_to_str (lp
->ptid
));
2226 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2227 get invoked despite our caller had them intentionally blocked by
2228 block_child_signals. This is sensitive only to the loop of
2229 linux_nat_wait_1 and there if we get called my_waitpid gets called
2230 again before it gets to sigsuspend so we can safely let the handlers
2231 get executed here. */
2233 if (debug_linux_nat
)
2234 fprintf_unfiltered (gdb_stdlog
, "WL: about to sigsuspend\n");
2235 sigsuspend (&suspend_mask
);
2238 restore_child_signals_mask (&prev_mask
);
2242 gdb_assert (pid
== ptid_get_lwp (lp
->ptid
));
2244 if (debug_linux_nat
)
2246 fprintf_unfiltered (gdb_stdlog
,
2247 "WL: waitpid %s received %s\n",
2248 target_pid_to_str (lp
->ptid
),
2249 status_to_str (status
));
2252 /* Check if the thread has exited. */
2253 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2255 if (report_thread_events
2256 || ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
))
2258 if (debug_linux_nat
)
2259 fprintf_unfiltered (gdb_stdlog
, "WL: LWP %d exited.\n",
2260 ptid_get_pid (lp
->ptid
));
2262 /* If this is the leader exiting, it means the whole
2263 process is gone. Store the status to report to the
2264 core. Store it in lp->waitstatus, because lp->status
2265 would be ambiguous (W_EXITCODE(0,0) == 0). */
2266 store_waitstatus (&lp
->waitstatus
, status
);
2271 if (debug_linux_nat
)
2272 fprintf_unfiltered (gdb_stdlog
, "WL: %s exited.\n",
2273 target_pid_to_str (lp
->ptid
));
2283 gdb_assert (WIFSTOPPED (status
));
2286 if (lp
->must_set_ptrace_flags
)
2288 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
2289 int options
= linux_nat_ptrace_options (inf
->attach_flag
);
2291 linux_enable_event_reporting (ptid_get_lwp (lp
->ptid
), options
);
2292 lp
->must_set_ptrace_flags
= 0;
2295 /* Handle GNU/Linux's syscall SIGTRAPs. */
2296 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2298 /* No longer need the sysgood bit. The ptrace event ends up
2299 recorded in lp->waitstatus if we care for it. We can carry
2300 on handling the event like a regular SIGTRAP from here
2302 status
= W_STOPCODE (SIGTRAP
);
2303 if (linux_handle_syscall_trap (lp
, 1))
2304 return wait_lwp (lp
);
2308 /* Almost all other ptrace-stops are known to be outside of system
2309 calls, with further exceptions in linux_handle_extended_wait. */
2310 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2313 /* Handle GNU/Linux's extended waitstatus for trace events. */
2314 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
2315 && linux_is_extended_waitstatus (status
))
2317 if (debug_linux_nat
)
2318 fprintf_unfiltered (gdb_stdlog
,
2319 "WL: Handling extended status 0x%06x\n",
2321 linux_handle_extended_wait (lp
, status
);
2328 /* Send a SIGSTOP to LP. */
2331 stop_callback (struct lwp_info
*lp
, void *data
)
2333 if (!lp
->stopped
&& !lp
->signalled
)
2337 if (debug_linux_nat
)
2339 fprintf_unfiltered (gdb_stdlog
,
2340 "SC: kill %s **<SIGSTOP>**\n",
2341 target_pid_to_str (lp
->ptid
));
2344 ret
= kill_lwp (ptid_get_lwp (lp
->ptid
), SIGSTOP
);
2345 if (debug_linux_nat
)
2347 fprintf_unfiltered (gdb_stdlog
,
2348 "SC: lwp kill %d %s\n",
2350 errno
? safe_strerror (errno
) : "ERRNO-OK");
2354 gdb_assert (lp
->status
== 0);
2360 /* Request a stop on LWP. */
2363 linux_stop_lwp (struct lwp_info
*lwp
)
2365 stop_callback (lwp
, NULL
);
2368 /* See linux-nat.h */
2371 linux_stop_and_wait_all_lwps (void)
2373 /* Stop all LWP's ... */
2374 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
2376 /* ... and wait until all of them have reported back that
2377 they're no longer running. */
2378 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
2381 /* See linux-nat.h */
2384 linux_unstop_all_lwps (void)
2386 iterate_over_lwps (minus_one_ptid
,
2387 resume_stopped_resumed_lwps
, &minus_one_ptid
);
2390 /* Return non-zero if LWP PID has a pending SIGINT. */
2393 linux_nat_has_pending_sigint (int pid
)
2395 sigset_t pending
, blocked
, ignored
;
2397 linux_proc_pending_signals (pid
, &pending
, &blocked
, &ignored
);
2399 if (sigismember (&pending
, SIGINT
)
2400 && !sigismember (&ignored
, SIGINT
))
2406 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2409 set_ignore_sigint (struct lwp_info
*lp
, void *data
)
2411 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2412 flag to consume the next one. */
2413 if (lp
->stopped
&& lp
->status
!= 0 && WIFSTOPPED (lp
->status
)
2414 && WSTOPSIG (lp
->status
) == SIGINT
)
2417 lp
->ignore_sigint
= 1;
2422 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2423 This function is called after we know the LWP has stopped; if the LWP
2424 stopped before the expected SIGINT was delivered, then it will never have
2425 arrived. Also, if the signal was delivered to a shared queue and consumed
2426 by a different thread, it will never be delivered to this LWP. */
2429 maybe_clear_ignore_sigint (struct lwp_info
*lp
)
2431 if (!lp
->ignore_sigint
)
2434 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp
->ptid
)))
2436 if (debug_linux_nat
)
2437 fprintf_unfiltered (gdb_stdlog
,
2438 "MCIS: Clearing bogus flag for %s\n",
2439 target_pid_to_str (lp
->ptid
));
2440 lp
->ignore_sigint
= 0;
2444 /* Fetch the possible triggered data watchpoint info and store it in
2447 On some archs, like x86, that use debug registers to set
2448 watchpoints, it's possible that the way to know which watched
2449 address trapped, is to check the register that is used to select
2450 which address to watch. Problem is, between setting the watchpoint
2451 and reading back which data address trapped, the user may change
2452 the set of watchpoints, and, as a consequence, GDB changes the
2453 debug registers in the inferior. To avoid reading back a stale
2454 stopped-data-address when that happens, we cache in LP the fact
2455 that a watchpoint trapped, and the corresponding data address, as
2456 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2457 registers meanwhile, we have the cached data we can rely on. */
2460 check_stopped_by_watchpoint (struct lwp_info
*lp
)
2462 struct cleanup
*old_chain
;
2464 if (linux_ops
->to_stopped_by_watchpoint
== NULL
)
2467 old_chain
= save_inferior_ptid ();
2468 inferior_ptid
= lp
->ptid
;
2470 if (linux_ops
->to_stopped_by_watchpoint (linux_ops
))
2472 lp
->stop_reason
= TARGET_STOPPED_BY_WATCHPOINT
;
2474 if (linux_ops
->to_stopped_data_address
!= NULL
)
2475 lp
->stopped_data_address_p
=
2476 linux_ops
->to_stopped_data_address (¤t_target
,
2477 &lp
->stopped_data_address
);
2479 lp
->stopped_data_address_p
= 0;
2482 do_cleanups (old_chain
);
2484 return lp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
2487 /* Returns true if the LWP had stopped for a watchpoint. */
2490 linux_nat_stopped_by_watchpoint (struct target_ops
*ops
)
2492 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2494 gdb_assert (lp
!= NULL
);
2496 return lp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
2500 linux_nat_stopped_data_address (struct target_ops
*ops
, CORE_ADDR
*addr_p
)
2502 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2504 gdb_assert (lp
!= NULL
);
2506 *addr_p
= lp
->stopped_data_address
;
2508 return lp
->stopped_data_address_p
;
2511 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2514 sigtrap_is_event (int status
)
2516 return WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
;
2519 /* Set alternative SIGTRAP-like events recognizer. If
2520 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2524 linux_nat_set_status_is_event (struct target_ops
*t
,
2525 int (*status_is_event
) (int status
))
2527 linux_nat_status_is_event
= status_is_event
;
2530 /* Wait until LP is stopped. */
2533 stop_wait_callback (struct lwp_info
*lp
, void *data
)
2535 struct inferior
*inf
= find_inferior_ptid (lp
->ptid
);
2537 /* If this is a vfork parent, bail out, it is not going to report
2538 any SIGSTOP until the vfork is done with. */
2539 if (inf
->vfork_child
!= NULL
)
2546 status
= wait_lwp (lp
);
2550 if (lp
->ignore_sigint
&& WIFSTOPPED (status
)
2551 && WSTOPSIG (status
) == SIGINT
)
2553 lp
->ignore_sigint
= 0;
2556 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
2558 if (debug_linux_nat
)
2559 fprintf_unfiltered (gdb_stdlog
,
2560 "PTRACE_CONT %s, 0, 0 (%s) "
2561 "(discarding SIGINT)\n",
2562 target_pid_to_str (lp
->ptid
),
2563 errno
? safe_strerror (errno
) : "OK");
2565 return stop_wait_callback (lp
, NULL
);
2568 maybe_clear_ignore_sigint (lp
);
2570 if (WSTOPSIG (status
) != SIGSTOP
)
2572 /* The thread was stopped with a signal other than SIGSTOP. */
2574 if (debug_linux_nat
)
2575 fprintf_unfiltered (gdb_stdlog
,
2576 "SWC: Pending event %s in %s\n",
2577 status_to_str ((int) status
),
2578 target_pid_to_str (lp
->ptid
));
2580 /* Save the sigtrap event. */
2581 lp
->status
= status
;
2582 gdb_assert (lp
->signalled
);
2583 save_stop_reason (lp
);
2587 /* We caught the SIGSTOP that we intended to catch, so
2588 there's no SIGSTOP pending. */
2590 if (debug_linux_nat
)
2591 fprintf_unfiltered (gdb_stdlog
,
2592 "SWC: Expected SIGSTOP caught for %s.\n",
2593 target_pid_to_str (lp
->ptid
));
2595 /* Reset SIGNALLED only after the stop_wait_callback call
2596 above as it does gdb_assert on SIGNALLED. */
2604 /* Return non-zero if LP has a wait status pending. Discard the
2605 pending event and resume the LWP if the event that originally
2606 caused the stop became uninteresting. */
2609 status_callback (struct lwp_info
*lp
, void *data
)
2611 /* Only report a pending wait status if we pretend that this has
2612 indeed been resumed. */
2616 if (!lwp_status_pending_p (lp
))
2619 if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
2620 || lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
)
2622 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
2626 pc
= regcache_read_pc (regcache
);
2628 if (pc
!= lp
->stop_pc
)
2630 if (debug_linux_nat
)
2631 fprintf_unfiltered (gdb_stdlog
,
2632 "SC: PC of %s changed. was=%s, now=%s\n",
2633 target_pid_to_str (lp
->ptid
),
2634 paddress (target_gdbarch (), lp
->stop_pc
),
2635 paddress (target_gdbarch (), pc
));
2639 #if !USE_SIGTRAP_SIGINFO
2640 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
2642 if (debug_linux_nat
)
2643 fprintf_unfiltered (gdb_stdlog
,
2644 "SC: previous breakpoint of %s, at %s gone\n",
2645 target_pid_to_str (lp
->ptid
),
2646 paddress (target_gdbarch (), lp
->stop_pc
));
2654 if (debug_linux_nat
)
2655 fprintf_unfiltered (gdb_stdlog
,
2656 "SC: pending event of %s cancelled.\n",
2657 target_pid_to_str (lp
->ptid
));
2660 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
2668 /* Count the LWP's that have had events. */
2671 count_events_callback (struct lwp_info
*lp
, void *data
)
2673 int *count
= (int *) data
;
2675 gdb_assert (count
!= NULL
);
2677 /* Select only resumed LWPs that have an event pending. */
2678 if (lp
->resumed
&& lwp_status_pending_p (lp
))
2684 /* Select the LWP (if any) that is currently being single-stepped. */
2687 select_singlestep_lwp_callback (struct lwp_info
*lp
, void *data
)
2689 if (lp
->last_resume_kind
== resume_step
2696 /* Returns true if LP has a status pending. */
2699 lwp_status_pending_p (struct lwp_info
*lp
)
2701 /* We check for lp->waitstatus in addition to lp->status, because we
2702 can have pending process exits recorded in lp->status and
2703 W_EXITCODE(0,0) happens to be 0. */
2704 return lp
->status
!= 0 || lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
;
2707 /* Select the Nth LWP that has had an event. */
2710 select_event_lwp_callback (struct lwp_info
*lp
, void *data
)
2712 int *selector
= (int *) data
;
2714 gdb_assert (selector
!= NULL
);
2716 /* Select only resumed LWPs that have an event pending. */
2717 if (lp
->resumed
&& lwp_status_pending_p (lp
))
2718 if ((*selector
)-- == 0)
2724 /* Called when the LWP stopped for a signal/trap. If it stopped for a
2725 trap check what caused it (breakpoint, watchpoint, trace, etc.),
2726 and save the result in the LWP's stop_reason field. If it stopped
2727 for a breakpoint, decrement the PC if necessary on the lwp's
2731 save_stop_reason (struct lwp_info
*lp
)
2733 struct regcache
*regcache
;
2734 struct gdbarch
*gdbarch
;
2737 #if USE_SIGTRAP_SIGINFO
2741 gdb_assert (lp
->stop_reason
== TARGET_STOPPED_BY_NO_REASON
);
2742 gdb_assert (lp
->status
!= 0);
2744 if (!linux_nat_status_is_event (lp
->status
))
2747 regcache
= get_thread_regcache (lp
->ptid
);
2748 gdbarch
= get_regcache_arch (regcache
);
2750 pc
= regcache_read_pc (regcache
);
2751 sw_bp_pc
= pc
- gdbarch_decr_pc_after_break (gdbarch
);
2753 #if USE_SIGTRAP_SIGINFO
2754 if (linux_nat_get_siginfo (lp
->ptid
, &siginfo
))
2756 if (siginfo
.si_signo
== SIGTRAP
)
2758 if (GDB_ARCH_IS_TRAP_BRKPT (siginfo
.si_code
)
2759 && GDB_ARCH_IS_TRAP_HWBKPT (siginfo
.si_code
))
2761 /* The si_code is ambiguous on this arch -- check debug
2763 if (!check_stopped_by_watchpoint (lp
))
2764 lp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
2766 else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo
.si_code
))
2768 /* If we determine the LWP stopped for a SW breakpoint,
2769 trust it. Particularly don't check watchpoint
2770 registers, because at least on s390, we'd find
2771 stopped-by-watchpoint as long as there's a watchpoint
2773 lp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
2775 else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo
.si_code
))
2777 /* This can indicate either a hardware breakpoint or
2778 hardware watchpoint. Check debug registers. */
2779 if (!check_stopped_by_watchpoint (lp
))
2780 lp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
2782 else if (siginfo
.si_code
== TRAP_TRACE
)
2784 if (debug_linux_nat
)
2785 fprintf_unfiltered (gdb_stdlog
,
2786 "CSBB: %s stopped by trace\n",
2787 target_pid_to_str (lp
->ptid
));
2789 /* We may have single stepped an instruction that
2790 triggered a watchpoint. In that case, on some
2791 architectures (such as x86), instead of TRAP_HWBKPT,
2792 si_code indicates TRAP_TRACE, and we need to check
2793 the debug registers separately. */
2794 check_stopped_by_watchpoint (lp
);
2799 if ((!lp
->step
|| lp
->stop_pc
== sw_bp_pc
)
2800 && software_breakpoint_inserted_here_p (get_regcache_aspace (regcache
),
2803 /* The LWP was either continued, or stepped a software
2804 breakpoint instruction. */
2805 lp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
2808 if (hardware_breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
2809 lp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
2811 if (lp
->stop_reason
== TARGET_STOPPED_BY_NO_REASON
)
2812 check_stopped_by_watchpoint (lp
);
2815 if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
)
2817 if (debug_linux_nat
)
2818 fprintf_unfiltered (gdb_stdlog
,
2819 "CSBB: %s stopped by software breakpoint\n",
2820 target_pid_to_str (lp
->ptid
));
2822 /* Back up the PC if necessary. */
2824 regcache_write_pc (regcache
, sw_bp_pc
);
2826 /* Update this so we record the correct stop PC below. */
2829 else if (lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
)
2831 if (debug_linux_nat
)
2832 fprintf_unfiltered (gdb_stdlog
,
2833 "CSBB: %s stopped by hardware breakpoint\n",
2834 target_pid_to_str (lp
->ptid
));
2836 else if (lp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
)
2838 if (debug_linux_nat
)
2839 fprintf_unfiltered (gdb_stdlog
,
2840 "CSBB: %s stopped by hardware watchpoint\n",
2841 target_pid_to_str (lp
->ptid
));
2848 /* Returns true if the LWP had stopped for a software breakpoint. */
2851 linux_nat_stopped_by_sw_breakpoint (struct target_ops
*ops
)
2853 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2855 gdb_assert (lp
!= NULL
);
2857 return lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
;
2860 /* Implement the supports_stopped_by_sw_breakpoint method. */
2863 linux_nat_supports_stopped_by_sw_breakpoint (struct target_ops
*ops
)
2865 return USE_SIGTRAP_SIGINFO
;
2868 /* Returns true if the LWP had stopped for a hardware
2869 breakpoint/watchpoint. */
2872 linux_nat_stopped_by_hw_breakpoint (struct target_ops
*ops
)
2874 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2876 gdb_assert (lp
!= NULL
);
2878 return lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
;
2881 /* Implement the supports_stopped_by_hw_breakpoint method. */
2884 linux_nat_supports_stopped_by_hw_breakpoint (struct target_ops
*ops
)
2886 return USE_SIGTRAP_SIGINFO
;
2889 /* Select one LWP out of those that have events pending. */
2892 select_event_lwp (ptid_t filter
, struct lwp_info
**orig_lp
, int *status
)
2895 int random_selector
;
2896 struct lwp_info
*event_lp
= NULL
;
2898 /* Record the wait status for the original LWP. */
2899 (*orig_lp
)->status
= *status
;
2901 /* In all-stop, give preference to the LWP that is being
2902 single-stepped. There will be at most one, and it will be the
2903 LWP that the core is most interested in. If we didn't do this,
2904 then we'd have to handle pending step SIGTRAPs somehow in case
2905 the core later continues the previously-stepped thread, as
2906 otherwise we'd report the pending SIGTRAP then, and the core, not
2907 having stepped the thread, wouldn't understand what the trap was
2908 for, and therefore would report it to the user as a random
2910 if (!target_is_non_stop_p ())
2912 event_lp
= iterate_over_lwps (filter
,
2913 select_singlestep_lwp_callback
, NULL
);
2914 if (event_lp
!= NULL
)
2916 if (debug_linux_nat
)
2917 fprintf_unfiltered (gdb_stdlog
,
2918 "SEL: Select single-step %s\n",
2919 target_pid_to_str (event_lp
->ptid
));
2923 if (event_lp
== NULL
)
2925 /* Pick one at random, out of those which have had events. */
2927 /* First see how many events we have. */
2928 iterate_over_lwps (filter
, count_events_callback
, &num_events
);
2929 gdb_assert (num_events
> 0);
2931 /* Now randomly pick a LWP out of those that have had
2933 random_selector
= (int)
2934 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
2936 if (debug_linux_nat
&& num_events
> 1)
2937 fprintf_unfiltered (gdb_stdlog
,
2938 "SEL: Found %d events, selecting #%d\n",
2939 num_events
, random_selector
);
2941 event_lp
= iterate_over_lwps (filter
,
2942 select_event_lwp_callback
,
2946 if (event_lp
!= NULL
)
2948 /* Switch the event LWP. */
2949 *orig_lp
= event_lp
;
2950 *status
= event_lp
->status
;
2953 /* Flush the wait status for the event LWP. */
2954 (*orig_lp
)->status
= 0;
2957 /* Return non-zero if LP has been resumed. */
2960 resumed_callback (struct lwp_info
*lp
, void *data
)
2965 /* Check if we should go on and pass this event to common code.
2966 Return the affected lwp if we are, or NULL otherwise. */
2968 static struct lwp_info
*
2969 linux_nat_filter_event (int lwpid
, int status
)
2971 struct lwp_info
*lp
;
2972 int event
= linux_ptrace_get_extended_event (status
);
2974 lp
= find_lwp_pid (pid_to_ptid (lwpid
));
2976 /* Check for stop events reported by a process we didn't already
2977 know about - anything not already in our LWP list.
2979 If we're expecting to receive stopped processes after
2980 fork, vfork, and clone events, then we'll just add the
2981 new one to our list and go back to waiting for the event
2982 to be reported - the stopped process might be returned
2983 from waitpid before or after the event is.
2985 But note the case of a non-leader thread exec'ing after the
2986 leader having exited, and gone from our lists. The non-leader
2987 thread changes its tid to the tgid. */
2989 if (WIFSTOPPED (status
) && lp
== NULL
2990 && (WSTOPSIG (status
) == SIGTRAP
&& event
== PTRACE_EVENT_EXEC
))
2992 /* A multi-thread exec after we had seen the leader exiting. */
2993 if (debug_linux_nat
)
2994 fprintf_unfiltered (gdb_stdlog
,
2995 "LLW: Re-adding thread group leader LWP %d.\n",
2998 lp
= add_lwp (ptid_build (lwpid
, lwpid
, 0));
3001 add_thread (lp
->ptid
);
3004 if (WIFSTOPPED (status
) && !lp
)
3006 if (debug_linux_nat
)
3007 fprintf_unfiltered (gdb_stdlog
,
3008 "LHEW: saving LWP %ld status %s in stopped_pids list\n",
3009 (long) lwpid
, status_to_str (status
));
3010 add_to_pid_list (&stopped_pids
, lwpid
, status
);
3014 /* Make sure we don't report an event for the exit of an LWP not in
3015 our list, i.e. not part of the current process. This can happen
3016 if we detach from a program we originally forked and then it
3018 if (!WIFSTOPPED (status
) && !lp
)
3021 /* This LWP is stopped now. (And if dead, this prevents it from
3022 ever being continued.) */
3025 if (WIFSTOPPED (status
) && lp
->must_set_ptrace_flags
)
3027 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
3028 int options
= linux_nat_ptrace_options (inf
->attach_flag
);
3030 linux_enable_event_reporting (ptid_get_lwp (lp
->ptid
), options
);
3031 lp
->must_set_ptrace_flags
= 0;
3034 /* Handle GNU/Linux's syscall SIGTRAPs. */
3035 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
3037 /* No longer need the sysgood bit. The ptrace event ends up
3038 recorded in lp->waitstatus if we care for it. We can carry
3039 on handling the event like a regular SIGTRAP from here
3041 status
= W_STOPCODE (SIGTRAP
);
3042 if (linux_handle_syscall_trap (lp
, 0))
3047 /* Almost all other ptrace-stops are known to be outside of system
3048 calls, with further exceptions in linux_handle_extended_wait. */
3049 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
3052 /* Handle GNU/Linux's extended waitstatus for trace events. */
3053 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
3054 && linux_is_extended_waitstatus (status
))
3056 if (debug_linux_nat
)
3057 fprintf_unfiltered (gdb_stdlog
,
3058 "LLW: Handling extended status 0x%06x\n",
3060 if (linux_handle_extended_wait (lp
, status
))
3064 /* Check if the thread has exited. */
3065 if (WIFEXITED (status
) || WIFSIGNALED (status
))
3067 if (!report_thread_events
3068 && num_lwps (ptid_get_pid (lp
->ptid
)) > 1)
3070 if (debug_linux_nat
)
3071 fprintf_unfiltered (gdb_stdlog
,
3072 "LLW: %s exited.\n",
3073 target_pid_to_str (lp
->ptid
));
3075 /* If there is at least one more LWP, then the exit signal
3076 was not the end of the debugged application and should be
3082 /* Note that even if the leader was ptrace-stopped, it can still
3083 exit, if e.g., some other thread brings down the whole
3084 process (calls `exit'). So don't assert that the lwp is
3086 if (debug_linux_nat
)
3087 fprintf_unfiltered (gdb_stdlog
,
3088 "LWP %ld exited (resumed=%d)\n",
3089 ptid_get_lwp (lp
->ptid
), lp
->resumed
);
3091 /* Dead LWP's aren't expected to reported a pending sigstop. */
3094 /* Store the pending event in the waitstatus, because
3095 W_EXITCODE(0,0) == 0. */
3096 store_waitstatus (&lp
->waitstatus
, status
);
3100 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3101 an attempt to stop an LWP. */
3103 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGSTOP
)
3107 if (lp
->last_resume_kind
== resume_stop
)
3109 if (debug_linux_nat
)
3110 fprintf_unfiltered (gdb_stdlog
,
3111 "LLW: resume_stop SIGSTOP caught for %s.\n",
3112 target_pid_to_str (lp
->ptid
));
3116 /* This is a delayed SIGSTOP. Filter out the event. */
3118 if (debug_linux_nat
)
3119 fprintf_unfiltered (gdb_stdlog
,
3120 "LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
3122 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3123 target_pid_to_str (lp
->ptid
));
3125 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
3126 gdb_assert (lp
->resumed
);
3131 /* Make sure we don't report a SIGINT that we have already displayed
3132 for another thread. */
3133 if (lp
->ignore_sigint
3134 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGINT
)
3136 if (debug_linux_nat
)
3137 fprintf_unfiltered (gdb_stdlog
,
3138 "LLW: Delayed SIGINT caught for %s.\n",
3139 target_pid_to_str (lp
->ptid
));
3141 /* This is a delayed SIGINT. */
3142 lp
->ignore_sigint
= 0;
3144 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
3145 if (debug_linux_nat
)
3146 fprintf_unfiltered (gdb_stdlog
,
3147 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3149 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3150 target_pid_to_str (lp
->ptid
));
3151 gdb_assert (lp
->resumed
);
3153 /* Discard the event. */
3157 /* Don't report signals that GDB isn't interested in, such as
3158 signals that are neither printed nor stopped upon. Stopping all
3159 threads can be a bit time-consuming so if we want decent
3160 performance with heavily multi-threaded programs, especially when
3161 they're using a high frequency timer, we'd better avoid it if we
3163 if (WIFSTOPPED (status
))
3165 enum gdb_signal signo
= gdb_signal_from_host (WSTOPSIG (status
));
3167 if (!target_is_non_stop_p ())
3169 /* Only do the below in all-stop, as we currently use SIGSTOP
3170 to implement target_stop (see linux_nat_stop) in
3172 if (signo
== GDB_SIGNAL_INT
&& signal_pass_state (signo
) == 0)
3174 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3175 forwarded to the entire process group, that is, all LWPs
3176 will receive it - unless they're using CLONE_THREAD to
3177 share signals. Since we only want to report it once, we
3178 mark it as ignored for all LWPs except this one. */
3179 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp
->ptid
)),
3180 set_ignore_sigint
, NULL
);
3181 lp
->ignore_sigint
= 0;
3184 maybe_clear_ignore_sigint (lp
);
3187 /* When using hardware single-step, we need to report every signal.
3188 Otherwise, signals in pass_mask may be short-circuited
3189 except signals that might be caused by a breakpoint. */
3191 && WSTOPSIG (status
) && sigismember (&pass_mask
, WSTOPSIG (status
))
3192 && !linux_wstatus_maybe_breakpoint (status
))
3194 linux_resume_one_lwp (lp
, lp
->step
, signo
);
3195 if (debug_linux_nat
)
3196 fprintf_unfiltered (gdb_stdlog
,
3197 "LLW: %s %s, %s (preempt 'handle')\n",
3199 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3200 target_pid_to_str (lp
->ptid
),
3201 (signo
!= GDB_SIGNAL_0
3202 ? strsignal (gdb_signal_to_host (signo
))
3208 /* An interesting event. */
3210 lp
->status
= status
;
3211 save_stop_reason (lp
);
3215 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3216 their exits until all other threads in the group have exited. */
3219 check_zombie_leaders (void)
3221 struct inferior
*inf
;
3225 struct lwp_info
*leader_lp
;
3230 leader_lp
= find_lwp_pid (pid_to_ptid (inf
->pid
));
3231 if (leader_lp
!= NULL
3232 /* Check if there are other threads in the group, as we may
3233 have raced with the inferior simply exiting. */
3234 && num_lwps (inf
->pid
) > 1
3235 && linux_proc_pid_is_zombie (inf
->pid
))
3237 if (debug_linux_nat
)
3238 fprintf_unfiltered (gdb_stdlog
,
3239 "CZL: Thread group leader %d zombie "
3240 "(it exited, or another thread execd).\n",
3243 /* A leader zombie can mean one of two things:
3245 - It exited, and there's an exit status pending
3246 available, or only the leader exited (not the whole
3247 program). In the latter case, we can't waitpid the
3248 leader's exit status until all other threads are gone.
3250 - There are 3 or more threads in the group, and a thread
3251 other than the leader exec'd. See comments on exec
3252 events at the top of the file. We could try
3253 distinguishing the exit and exec cases, by waiting once
3254 more, and seeing if something comes out, but it doesn't
3255 sound useful. The previous leader _does_ go away, and
3256 we'll re-add the new one once we see the exec event
3257 (which is just the same as what would happen if the
3258 previous leader did exit voluntarily before some other
3261 if (debug_linux_nat
)
3262 fprintf_unfiltered (gdb_stdlog
,
3263 "CZL: Thread group leader %d vanished.\n",
3265 exit_lwp (leader_lp
);
3270 /* Convenience function that is called when the kernel reports an exit
3271 event. This decides whether to report the event to GDB as a
3272 process exit event, a thread exit event, or to suppress the
3276 filter_exit_event (struct lwp_info
*event_child
,
3277 struct target_waitstatus
*ourstatus
)
3279 ptid_t ptid
= event_child
->ptid
;
3281 if (num_lwps (ptid_get_pid (ptid
)) > 1)
3283 if (report_thread_events
)
3284 ourstatus
->kind
= TARGET_WAITKIND_THREAD_EXITED
;
3286 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3288 exit_lwp (event_child
);
3295 linux_nat_wait_1 (struct target_ops
*ops
,
3296 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3300 enum resume_kind last_resume_kind
;
3301 struct lwp_info
*lp
;
3304 if (debug_linux_nat
)
3305 fprintf_unfiltered (gdb_stdlog
, "LLW: enter\n");
3307 /* The first time we get here after starting a new inferior, we may
3308 not have added it to the LWP list yet - this is the earliest
3309 moment at which we know its PID. */
3310 if (ptid_is_pid (inferior_ptid
))
3312 /* Upgrade the main thread's ptid. */
3313 thread_change_ptid (inferior_ptid
,
3314 ptid_build (ptid_get_pid (inferior_ptid
),
3315 ptid_get_pid (inferior_ptid
), 0));
3317 lp
= add_initial_lwp (inferior_ptid
);
3321 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3322 block_child_signals (&prev_mask
);
3324 /* First check if there is a LWP with a wait status pending. */
3325 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3328 if (debug_linux_nat
)
3329 fprintf_unfiltered (gdb_stdlog
,
3330 "LLW: Using pending wait status %s for %s.\n",
3331 status_to_str (lp
->status
),
3332 target_pid_to_str (lp
->ptid
));
3335 /* But if we don't find a pending event, we'll have to wait. Always
3336 pull all events out of the kernel. We'll randomly select an
3337 event LWP out of all that have events, to prevent starvation. */
3343 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3346 - If the thread group leader exits while other threads in the
3347 thread group still exist, waitpid(TGID, ...) hangs. That
3348 waitpid won't return an exit status until the other threads
3349 in the group are reapped.
3351 - When a non-leader thread execs, that thread just vanishes
3352 without reporting an exit (so we'd hang if we waited for it
3353 explicitly in that case). The exec event is reported to
3357 lwpid
= my_waitpid (-1, &status
, __WALL
| WNOHANG
);
3359 if (debug_linux_nat
)
3360 fprintf_unfiltered (gdb_stdlog
,
3361 "LNW: waitpid(-1, ...) returned %d, %s\n",
3362 lwpid
, errno
? safe_strerror (errno
) : "ERRNO-OK");
3366 if (debug_linux_nat
)
3368 fprintf_unfiltered (gdb_stdlog
,
3369 "LLW: waitpid %ld received %s\n",
3370 (long) lwpid
, status_to_str (status
));
3373 linux_nat_filter_event (lwpid
, status
);
3374 /* Retry until nothing comes out of waitpid. A single
3375 SIGCHLD can indicate more than one child stopped. */
3379 /* Now that we've pulled all events out of the kernel, resume
3380 LWPs that don't have an interesting event to report. */
3381 iterate_over_lwps (minus_one_ptid
,
3382 resume_stopped_resumed_lwps
, &minus_one_ptid
);
3384 /* ... and find an LWP with a status to report to the core, if
3386 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3390 /* Check for zombie thread group leaders. Those can't be reaped
3391 until all other threads in the thread group are. */
3392 check_zombie_leaders ();
3394 /* If there are no resumed children left, bail. We'd be stuck
3395 forever in the sigsuspend call below otherwise. */
3396 if (iterate_over_lwps (ptid
, resumed_callback
, NULL
) == NULL
)
3398 if (debug_linux_nat
)
3399 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (no resumed LWP)\n");
3401 ourstatus
->kind
= TARGET_WAITKIND_NO_RESUMED
;
3403 restore_child_signals_mask (&prev_mask
);
3404 return minus_one_ptid
;
3407 /* No interesting event to report to the core. */
3409 if (target_options
& TARGET_WNOHANG
)
3411 if (debug_linux_nat
)
3412 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (ignore)\n");
3414 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3415 restore_child_signals_mask (&prev_mask
);
3416 return minus_one_ptid
;
3419 /* We shouldn't end up here unless we want to try again. */
3420 gdb_assert (lp
== NULL
);
3422 /* Block until we get an event reported with SIGCHLD. */
3423 if (debug_linux_nat
)
3424 fprintf_unfiltered (gdb_stdlog
, "LNW: about to sigsuspend\n");
3425 sigsuspend (&suspend_mask
);
3430 status
= lp
->status
;
3433 if (!target_is_non_stop_p ())
3435 /* Now stop all other LWP's ... */
3436 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
3438 /* ... and wait until all of them have reported back that
3439 they're no longer running. */
3440 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
3443 /* If we're not waiting for a specific LWP, choose an event LWP from
3444 among those that have had events. Giving equal priority to all
3445 LWPs that have had events helps prevent starvation. */
3446 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3447 select_event_lwp (ptid
, &lp
, &status
);
3449 gdb_assert (lp
!= NULL
);
3451 /* Now that we've selected our final event LWP, un-adjust its PC if
3452 it was a software breakpoint, and we can't reliably support the
3453 "stopped by software breakpoint" stop reason. */
3454 if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3455 && !USE_SIGTRAP_SIGINFO
)
3457 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3458 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3459 int decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3465 pc
= regcache_read_pc (regcache
);
3466 regcache_write_pc (regcache
, pc
+ decr_pc
);
3470 /* We'll need this to determine whether to report a SIGSTOP as
3471 GDB_SIGNAL_0. Need to take a copy because resume_clear_callback
3473 last_resume_kind
= lp
->last_resume_kind
;
3475 if (!target_is_non_stop_p ())
3477 /* In all-stop, from the core's perspective, all LWPs are now
3478 stopped until a new resume action is sent over. */
3479 iterate_over_lwps (minus_one_ptid
, resume_clear_callback
, NULL
);
3483 resume_clear_callback (lp
, NULL
);
3486 if (linux_nat_status_is_event (status
))
3488 if (debug_linux_nat
)
3489 fprintf_unfiltered (gdb_stdlog
,
3490 "LLW: trap ptid is %s.\n",
3491 target_pid_to_str (lp
->ptid
));
3494 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3496 *ourstatus
= lp
->waitstatus
;
3497 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3500 store_waitstatus (ourstatus
, status
);
3502 if (debug_linux_nat
)
3503 fprintf_unfiltered (gdb_stdlog
, "LLW: exit\n");
3505 restore_child_signals_mask (&prev_mask
);
3507 if (last_resume_kind
== resume_stop
3508 && ourstatus
->kind
== TARGET_WAITKIND_STOPPED
3509 && WSTOPSIG (status
) == SIGSTOP
)
3511 /* A thread that has been requested to stop by GDB with
3512 target_stop, and it stopped cleanly, so report as SIG0. The
3513 use of SIGSTOP is an implementation detail. */
3514 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3517 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
3518 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
3521 lp
->core
= linux_common_core_of_thread (lp
->ptid
);
3523 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
)
3524 return filter_exit_event (lp
, ourstatus
);
3529 /* Resume LWPs that are currently stopped without any pending status
3530 to report, but are resumed from the core's perspective. */
3533 resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
)
3535 ptid_t
*wait_ptid_p
= (ptid_t
*) data
;
3539 if (debug_linux_nat
)
3540 fprintf_unfiltered (gdb_stdlog
,
3541 "RSRL: NOT resuming LWP %s, not stopped\n",
3542 target_pid_to_str (lp
->ptid
));
3544 else if (!lp
->resumed
)
3546 if (debug_linux_nat
)
3547 fprintf_unfiltered (gdb_stdlog
,
3548 "RSRL: NOT resuming LWP %s, not resumed\n",
3549 target_pid_to_str (lp
->ptid
));
3551 else if (lwp_status_pending_p (lp
))
3553 if (debug_linux_nat
)
3554 fprintf_unfiltered (gdb_stdlog
,
3555 "RSRL: NOT resuming LWP %s, has pending status\n",
3556 target_pid_to_str (lp
->ptid
));
3560 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3561 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3565 CORE_ADDR pc
= regcache_read_pc (regcache
);
3566 int leave_stopped
= 0;
3568 /* Don't bother if there's a breakpoint at PC that we'd hit
3569 immediately, and we're not waiting for this LWP. */
3570 if (!ptid_match (lp
->ptid
, *wait_ptid_p
))
3572 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
3578 if (debug_linux_nat
)
3579 fprintf_unfiltered (gdb_stdlog
,
3580 "RSRL: resuming stopped-resumed LWP %s at "
3582 target_pid_to_str (lp
->ptid
),
3583 paddress (gdbarch
, pc
),
3586 linux_resume_one_lwp_throw (lp
, lp
->step
, GDB_SIGNAL_0
);
3589 CATCH (ex
, RETURN_MASK_ERROR
)
3591 if (!check_ptrace_stopped_lwp_gone (lp
))
3592 throw_exception (ex
);
3601 linux_nat_wait (struct target_ops
*ops
,
3602 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3607 if (debug_linux_nat
)
3609 char *options_string
;
3611 options_string
= target_options_to_string (target_options
);
3612 fprintf_unfiltered (gdb_stdlog
,
3613 "linux_nat_wait: [%s], [%s]\n",
3614 target_pid_to_str (ptid
),
3616 xfree (options_string
);
3619 /* Flush the async file first. */
3620 if (target_is_async_p ())
3621 async_file_flush ();
3623 /* Resume LWPs that are currently stopped without any pending status
3624 to report, but are resumed from the core's perspective. LWPs get
3625 in this state if we find them stopping at a time we're not
3626 interested in reporting the event (target_wait on a
3627 specific_process, for example, see linux_nat_wait_1), and
3628 meanwhile the event became uninteresting. Don't bother resuming
3629 LWPs we're not going to wait for if they'd stop immediately. */
3630 if (target_is_non_stop_p ())
3631 iterate_over_lwps (minus_one_ptid
, resume_stopped_resumed_lwps
, &ptid
);
3633 event_ptid
= linux_nat_wait_1 (ops
, ptid
, ourstatus
, target_options
);
3635 /* If we requested any event, and something came out, assume there
3636 may be more. If we requested a specific lwp or process, also
3637 assume there may be more. */
3638 if (target_is_async_p ()
3639 && ((ourstatus
->kind
!= TARGET_WAITKIND_IGNORE
3640 && ourstatus
->kind
!= TARGET_WAITKIND_NO_RESUMED
)
3641 || !ptid_equal (ptid
, minus_one_ptid
)))
3650 kill_one_lwp (pid_t pid
)
3652 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3655 kill_lwp (pid
, SIGKILL
);
3656 if (debug_linux_nat
)
3658 int save_errno
= errno
;
3660 fprintf_unfiltered (gdb_stdlog
,
3661 "KC: kill (SIGKILL) %ld, 0, 0 (%s)\n", (long) pid
,
3662 save_errno
? safe_strerror (save_errno
) : "OK");
3665 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3668 ptrace (PTRACE_KILL
, pid
, 0, 0);
3669 if (debug_linux_nat
)
3671 int save_errno
= errno
;
3673 fprintf_unfiltered (gdb_stdlog
,
3674 "KC: PTRACE_KILL %ld, 0, 0 (%s)\n", (long) pid
,
3675 save_errno
? safe_strerror (save_errno
) : "OK");
3679 /* Wait for an LWP to die. */
3682 kill_wait_one_lwp (pid_t pid
)
3686 /* We must make sure that there are no pending events (delayed
3687 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3688 program doesn't interfere with any following debugging session. */
3692 res
= my_waitpid (pid
, NULL
, __WALL
);
3693 if (res
!= (pid_t
) -1)
3695 if (debug_linux_nat
)
3696 fprintf_unfiltered (gdb_stdlog
,
3697 "KWC: wait %ld received unknown.\n",
3699 /* The Linux kernel sometimes fails to kill a thread
3700 completely after PTRACE_KILL; that goes from the stop
3701 point in do_fork out to the one in get_signal_to_deliver
3702 and waits again. So kill it again. */
3708 gdb_assert (res
== -1 && errno
== ECHILD
);
3711 /* Callback for iterate_over_lwps. */
3714 kill_callback (struct lwp_info
*lp
, void *data
)
3716 kill_one_lwp (ptid_get_lwp (lp
->ptid
));
3720 /* Callback for iterate_over_lwps. */
3723 kill_wait_callback (struct lwp_info
*lp
, void *data
)
3725 kill_wait_one_lwp (ptid_get_lwp (lp
->ptid
));
3729 /* Kill the fork children of any threads of inferior INF that are
3730 stopped at a fork event. */
3733 kill_unfollowed_fork_children (struct inferior
*inf
)
3735 struct thread_info
*thread
;
3737 ALL_NON_EXITED_THREADS (thread
)
3738 if (thread
->inf
== inf
)
3740 struct target_waitstatus
*ws
= &thread
->pending_follow
;
3742 if (ws
->kind
== TARGET_WAITKIND_FORKED
3743 || ws
->kind
== TARGET_WAITKIND_VFORKED
)
3745 ptid_t child_ptid
= ws
->value
.related_pid
;
3746 int child_pid
= ptid_get_pid (child_ptid
);
3747 int child_lwp
= ptid_get_lwp (child_ptid
);
3749 kill_one_lwp (child_lwp
);
3750 kill_wait_one_lwp (child_lwp
);
3752 /* Let the arch-specific native code know this process is
3754 linux_nat_forget_process (child_pid
);
3760 linux_nat_kill (struct target_ops
*ops
)
3762 /* If we're stopped while forking and we haven't followed yet,
3763 kill the other task. We need to do this first because the
3764 parent will be sleeping if this is a vfork. */
3765 kill_unfollowed_fork_children (current_inferior ());
3767 if (forks_exist_p ())
3768 linux_fork_killall ();
3771 ptid_t ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
3773 /* Stop all threads before killing them, since ptrace requires
3774 that the thread is stopped to sucessfully PTRACE_KILL. */
3775 iterate_over_lwps (ptid
, stop_callback
, NULL
);
3776 /* ... and wait until all of them have reported back that
3777 they're no longer running. */
3778 iterate_over_lwps (ptid
, stop_wait_callback
, NULL
);
3780 /* Kill all LWP's ... */
3781 iterate_over_lwps (ptid
, kill_callback
, NULL
);
3783 /* ... and wait until we've flushed all events. */
3784 iterate_over_lwps (ptid
, kill_wait_callback
, NULL
);
3787 target_mourn_inferior (inferior_ptid
);
3791 linux_nat_mourn_inferior (struct target_ops
*ops
)
3793 int pid
= ptid_get_pid (inferior_ptid
);
3795 purge_lwp_list (pid
);
3797 if (! forks_exist_p ())
3798 /* Normal case, no other forks available. */
3799 linux_ops
->to_mourn_inferior (ops
);
3801 /* Multi-fork case. The current inferior_ptid has exited, but
3802 there are other viable forks to debug. Delete the exiting
3803 one and context-switch to the first available. */
3804 linux_fork_mourn_inferior ();
3806 /* Let the arch-specific native code know this process is gone. */
3807 linux_nat_forget_process (pid
);
3810 /* Convert a native/host siginfo object, into/from the siginfo in the
3811 layout of the inferiors' architecture. */
3814 siginfo_fixup (siginfo_t
*siginfo
, gdb_byte
*inf_siginfo
, int direction
)
3818 if (linux_nat_siginfo_fixup
!= NULL
)
3819 done
= linux_nat_siginfo_fixup (siginfo
, inf_siginfo
, direction
);
3821 /* If there was no callback, or the callback didn't do anything,
3822 then just do a straight memcpy. */
3826 memcpy (siginfo
, inf_siginfo
, sizeof (siginfo_t
));
3828 memcpy (inf_siginfo
, siginfo
, sizeof (siginfo_t
));
3832 static enum target_xfer_status
3833 linux_xfer_siginfo (struct target_ops
*ops
, enum target_object object
,
3834 const char *annex
, gdb_byte
*readbuf
,
3835 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
3836 ULONGEST
*xfered_len
)
3840 gdb_byte inf_siginfo
[sizeof (siginfo_t
)];
3842 gdb_assert (object
== TARGET_OBJECT_SIGNAL_INFO
);
3843 gdb_assert (readbuf
|| writebuf
);
3845 pid
= ptid_get_lwp (inferior_ptid
);
3847 pid
= ptid_get_pid (inferior_ptid
);
3849 if (offset
> sizeof (siginfo
))
3850 return TARGET_XFER_E_IO
;
3853 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3855 return TARGET_XFER_E_IO
;
3857 /* When GDB is built as a 64-bit application, ptrace writes into
3858 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3859 inferior with a 64-bit GDB should look the same as debugging it
3860 with a 32-bit GDB, we need to convert it. GDB core always sees
3861 the converted layout, so any read/write will have to be done
3863 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
3865 if (offset
+ len
> sizeof (siginfo
))
3866 len
= sizeof (siginfo
) - offset
;
3868 if (readbuf
!= NULL
)
3869 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
3872 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
3874 /* Convert back to ptrace layout before flushing it out. */
3875 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
3878 ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3880 return TARGET_XFER_E_IO
;
3884 return TARGET_XFER_OK
;
3887 static enum target_xfer_status
3888 linux_nat_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3889 const char *annex
, gdb_byte
*readbuf
,
3890 const gdb_byte
*writebuf
,
3891 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
3893 struct cleanup
*old_chain
;
3894 enum target_xfer_status xfer
;
3896 if (object
== TARGET_OBJECT_SIGNAL_INFO
)
3897 return linux_xfer_siginfo (ops
, object
, annex
, readbuf
, writebuf
,
3898 offset
, len
, xfered_len
);
3900 /* The target is connected but no live inferior is selected. Pass
3901 this request down to a lower stratum (e.g., the executable
3903 if (object
== TARGET_OBJECT_MEMORY
&& ptid_equal (inferior_ptid
, null_ptid
))
3904 return TARGET_XFER_EOF
;
3906 old_chain
= save_inferior_ptid ();
3908 if (ptid_lwp_p (inferior_ptid
))
3909 inferior_ptid
= pid_to_ptid (ptid_get_lwp (inferior_ptid
));
3911 xfer
= linux_ops
->to_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
3912 offset
, len
, xfered_len
);
3914 do_cleanups (old_chain
);
3919 linux_nat_thread_alive (struct target_ops
*ops
, ptid_t ptid
)
3921 /* As long as a PTID is in lwp list, consider it alive. */
3922 return find_lwp_pid (ptid
) != NULL
;
3925 /* Implement the to_update_thread_list target method for this
3929 linux_nat_update_thread_list (struct target_ops
*ops
)
3931 struct lwp_info
*lwp
;
3933 /* We add/delete threads from the list as clone/exit events are
3934 processed, so just try deleting exited threads still in the
3936 delete_exited_threads ();
3938 /* Update the processor core that each lwp/thread was last seen
3942 /* Avoid accessing /proc if the thread hasn't run since we last
3943 time we fetched the thread's core. Accessing /proc becomes
3944 noticeably expensive when we have thousands of LWPs. */
3945 if (lwp
->core
== -1)
3946 lwp
->core
= linux_common_core_of_thread (lwp
->ptid
);
3951 linux_nat_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
3953 static char buf
[64];
3955 if (ptid_lwp_p (ptid
)
3956 && (ptid_get_pid (ptid
) != ptid_get_lwp (ptid
)
3957 || num_lwps (ptid_get_pid (ptid
)) > 1))
3959 snprintf (buf
, sizeof (buf
), "LWP %ld", ptid_get_lwp (ptid
));
3963 return normal_pid_to_str (ptid
);
3967 linux_nat_thread_name (struct target_ops
*self
, struct thread_info
*thr
)
3969 return linux_proc_tid_get_name (thr
->ptid
);
3972 /* Accepts an integer PID; Returns a string representing a file that
3973 can be opened to get the symbols for the child process. */
3976 linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
)
3978 return linux_proc_pid_to_exec_file (pid
);
3981 /* Implement the to_xfer_partial interface for memory reads using the /proc
3982 filesystem. Because we can use a single read() call for /proc, this
3983 can be much more efficient than banging away at PTRACE_PEEKTEXT,
3984 but it doesn't support writes. */
3986 static enum target_xfer_status
3987 linux_proc_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3988 const char *annex
, gdb_byte
*readbuf
,
3989 const gdb_byte
*writebuf
,
3990 ULONGEST offset
, LONGEST len
, ULONGEST
*xfered_len
)
3996 if (object
!= TARGET_OBJECT_MEMORY
|| !readbuf
)
3997 return TARGET_XFER_EOF
;
3999 /* Don't bother for one word. */
4000 if (len
< 3 * sizeof (long))
4001 return TARGET_XFER_EOF
;
4003 /* We could keep this file open and cache it - possibly one per
4004 thread. That requires some juggling, but is even faster. */
4005 xsnprintf (filename
, sizeof filename
, "/proc/%d/mem",
4006 ptid_get_pid (inferior_ptid
));
4007 fd
= gdb_open_cloexec (filename
, O_RDONLY
| O_LARGEFILE
, 0);
4009 return TARGET_XFER_EOF
;
4011 /* If pread64 is available, use it. It's faster if the kernel
4012 supports it (only one syscall), and it's 64-bit safe even on
4013 32-bit platforms (for instance, SPARC debugging a SPARC64
4016 if (pread64 (fd
, readbuf
, len
, offset
) != len
)
4018 if (lseek (fd
, offset
, SEEK_SET
) == -1 || read (fd
, readbuf
, len
) != len
)
4027 return TARGET_XFER_EOF
;
4031 return TARGET_XFER_OK
;
4036 /* Enumerate spufs IDs for process PID. */
4038 spu_enumerate_spu_ids (int pid
, gdb_byte
*buf
, ULONGEST offset
, ULONGEST len
)
4040 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
4042 LONGEST written
= 0;
4045 struct dirent
*entry
;
4047 xsnprintf (path
, sizeof path
, "/proc/%d/fd", pid
);
4048 dir
= opendir (path
);
4053 while ((entry
= readdir (dir
)) != NULL
)
4059 fd
= atoi (entry
->d_name
);
4063 xsnprintf (path
, sizeof path
, "/proc/%d/fd/%d", pid
, fd
);
4064 if (stat (path
, &st
) != 0)
4066 if (!S_ISDIR (st
.st_mode
))
4069 if (statfs (path
, &stfs
) != 0)
4071 if (stfs
.f_type
!= SPUFS_MAGIC
)
4074 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4076 store_unsigned_integer (buf
+ pos
- offset
, 4, byte_order
, fd
);
4086 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4087 object type, using the /proc file system. */
4089 static enum target_xfer_status
4090 linux_proc_xfer_spu (struct target_ops
*ops
, enum target_object object
,
4091 const char *annex
, gdb_byte
*readbuf
,
4092 const gdb_byte
*writebuf
,
4093 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
4098 int pid
= ptid_get_pid (inferior_ptid
);
4103 return TARGET_XFER_E_IO
;
4106 LONGEST l
= spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4109 return TARGET_XFER_E_IO
;
4111 return TARGET_XFER_EOF
;
4114 *xfered_len
= (ULONGEST
) l
;
4115 return TARGET_XFER_OK
;
4120 xsnprintf (buf
, sizeof buf
, "/proc/%d/fd/%s", pid
, annex
);
4121 fd
= gdb_open_cloexec (buf
, writebuf
? O_WRONLY
: O_RDONLY
, 0);
4123 return TARGET_XFER_E_IO
;
4126 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4129 return TARGET_XFER_EOF
;
4133 ret
= write (fd
, writebuf
, (size_t) len
);
4135 ret
= read (fd
, readbuf
, (size_t) len
);
4140 return TARGET_XFER_E_IO
;
4142 return TARGET_XFER_EOF
;
4145 *xfered_len
= (ULONGEST
) ret
;
4146 return TARGET_XFER_OK
;
4151 /* Parse LINE as a signal set and add its set bits to SIGS. */
4154 add_line_to_sigset (const char *line
, sigset_t
*sigs
)
4156 int len
= strlen (line
) - 1;
4160 if (line
[len
] != '\n')
4161 error (_("Could not parse signal set: %s"), line
);
4169 if (*p
>= '0' && *p
<= '9')
4171 else if (*p
>= 'a' && *p
<= 'f')
4172 digit
= *p
- 'a' + 10;
4174 error (_("Could not parse signal set: %s"), line
);
4179 sigaddset (sigs
, signum
+ 1);
4181 sigaddset (sigs
, signum
+ 2);
4183 sigaddset (sigs
, signum
+ 3);
4185 sigaddset (sigs
, signum
+ 4);
4191 /* Find process PID's pending signals from /proc/pid/status and set
4195 linux_proc_pending_signals (int pid
, sigset_t
*pending
,
4196 sigset_t
*blocked
, sigset_t
*ignored
)
4199 char buffer
[PATH_MAX
], fname
[PATH_MAX
];
4200 struct cleanup
*cleanup
;
4202 sigemptyset (pending
);
4203 sigemptyset (blocked
);
4204 sigemptyset (ignored
);
4205 xsnprintf (fname
, sizeof fname
, "/proc/%d/status", pid
);
4206 procfile
= gdb_fopen_cloexec (fname
, "r");
4207 if (procfile
== NULL
)
4208 error (_("Could not open %s"), fname
);
4209 cleanup
= make_cleanup_fclose (procfile
);
4211 while (fgets (buffer
, PATH_MAX
, procfile
) != NULL
)
4213 /* Normal queued signals are on the SigPnd line in the status
4214 file. However, 2.6 kernels also have a "shared" pending
4215 queue for delivering signals to a thread group, so check for
4218 Unfortunately some Red Hat kernels include the shared pending
4219 queue but not the ShdPnd status field. */
4221 if (startswith (buffer
, "SigPnd:\t"))
4222 add_line_to_sigset (buffer
+ 8, pending
);
4223 else if (startswith (buffer
, "ShdPnd:\t"))
4224 add_line_to_sigset (buffer
+ 8, pending
);
4225 else if (startswith (buffer
, "SigBlk:\t"))
4226 add_line_to_sigset (buffer
+ 8, blocked
);
4227 else if (startswith (buffer
, "SigIgn:\t"))
4228 add_line_to_sigset (buffer
+ 8, ignored
);
4231 do_cleanups (cleanup
);
4234 static enum target_xfer_status
4235 linux_nat_xfer_osdata (struct target_ops
*ops
, enum target_object object
,
4236 const char *annex
, gdb_byte
*readbuf
,
4237 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4238 ULONGEST
*xfered_len
)
4240 gdb_assert (object
== TARGET_OBJECT_OSDATA
);
4242 *xfered_len
= linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
4243 if (*xfered_len
== 0)
4244 return TARGET_XFER_EOF
;
4246 return TARGET_XFER_OK
;
4249 static enum target_xfer_status
4250 linux_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4251 const char *annex
, gdb_byte
*readbuf
,
4252 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4253 ULONGEST
*xfered_len
)
4255 enum target_xfer_status xfer
;
4257 if (object
== TARGET_OBJECT_AUXV
)
4258 return memory_xfer_auxv (ops
, object
, annex
, readbuf
, writebuf
,
4259 offset
, len
, xfered_len
);
4261 if (object
== TARGET_OBJECT_OSDATA
)
4262 return linux_nat_xfer_osdata (ops
, object
, annex
, readbuf
, writebuf
,
4263 offset
, len
, xfered_len
);
4265 if (object
== TARGET_OBJECT_SPU
)
4266 return linux_proc_xfer_spu (ops
, object
, annex
, readbuf
, writebuf
,
4267 offset
, len
, xfered_len
);
4269 /* GDB calculates all the addresses in possibly larget width of the address.
4270 Address width needs to be masked before its final use - either by
4271 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4273 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4275 if (object
== TARGET_OBJECT_MEMORY
)
4277 int addr_bit
= gdbarch_addr_bit (target_gdbarch ());
4279 if (addr_bit
< (sizeof (ULONGEST
) * HOST_CHAR_BIT
))
4280 offset
&= ((ULONGEST
) 1 << addr_bit
) - 1;
4283 xfer
= linux_proc_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4284 offset
, len
, xfered_len
);
4285 if (xfer
!= TARGET_XFER_EOF
)
4288 return super_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4289 offset
, len
, xfered_len
);
4293 cleanup_target_stop (void *arg
)
4295 ptid_t
*ptid
= (ptid_t
*) arg
;
4297 gdb_assert (arg
!= NULL
);
4300 target_continue_no_signal (*ptid
);
4303 static VEC(static_tracepoint_marker_p
) *
4304 linux_child_static_tracepoint_markers_by_strid (struct target_ops
*self
,
4307 char s
[IPA_CMD_BUF_SIZE
];
4308 struct cleanup
*old_chain
;
4309 int pid
= ptid_get_pid (inferior_ptid
);
4310 VEC(static_tracepoint_marker_p
) *markers
= NULL
;
4311 struct static_tracepoint_marker
*marker
= NULL
;
4313 ptid_t ptid
= ptid_build (pid
, 0, 0);
4318 memcpy (s
, "qTfSTM", sizeof ("qTfSTM"));
4319 s
[sizeof ("qTfSTM")] = 0;
4321 agent_run_command (pid
, s
, strlen (s
) + 1);
4323 old_chain
= make_cleanup (free_current_marker
, &marker
);
4324 make_cleanup (cleanup_target_stop
, &ptid
);
4329 marker
= XCNEW (struct static_tracepoint_marker
);
4333 parse_static_tracepoint_marker_definition (p
, &p
, marker
);
4335 if (strid
== NULL
|| strcmp (strid
, marker
->str_id
) == 0)
4337 VEC_safe_push (static_tracepoint_marker_p
,
4343 release_static_tracepoint_marker (marker
);
4344 memset (marker
, 0, sizeof (*marker
));
4347 while (*p
++ == ','); /* comma-separated list */
4349 memcpy (s
, "qTsSTM", sizeof ("qTsSTM"));
4350 s
[sizeof ("qTsSTM")] = 0;
4351 agent_run_command (pid
, s
, strlen (s
) + 1);
4355 do_cleanups (old_chain
);
4360 /* Create a prototype generic GNU/Linux target. The client can override
4361 it with local methods. */
4364 linux_target_install_ops (struct target_ops
*t
)
4366 t
->to_insert_fork_catchpoint
= linux_child_insert_fork_catchpoint
;
4367 t
->to_remove_fork_catchpoint
= linux_child_remove_fork_catchpoint
;
4368 t
->to_insert_vfork_catchpoint
= linux_child_insert_vfork_catchpoint
;
4369 t
->to_remove_vfork_catchpoint
= linux_child_remove_vfork_catchpoint
;
4370 t
->to_insert_exec_catchpoint
= linux_child_insert_exec_catchpoint
;
4371 t
->to_remove_exec_catchpoint
= linux_child_remove_exec_catchpoint
;
4372 t
->to_set_syscall_catchpoint
= linux_child_set_syscall_catchpoint
;
4373 t
->to_pid_to_exec_file
= linux_child_pid_to_exec_file
;
4374 t
->to_post_startup_inferior
= linux_child_post_startup_inferior
;
4375 t
->to_post_attach
= linux_child_post_attach
;
4376 t
->to_follow_fork
= linux_child_follow_fork
;
4378 super_xfer_partial
= t
->to_xfer_partial
;
4379 t
->to_xfer_partial
= linux_xfer_partial
;
4381 t
->to_static_tracepoint_markers_by_strid
4382 = linux_child_static_tracepoint_markers_by_strid
;
4388 struct target_ops
*t
;
4390 t
= inf_ptrace_target ();
4391 linux_target_install_ops (t
);
4397 linux_trad_target (CORE_ADDR (*register_u_offset
)(struct gdbarch
*, int, int))
4399 struct target_ops
*t
;
4401 t
= inf_ptrace_trad_target (register_u_offset
);
4402 linux_target_install_ops (t
);
4407 /* target_is_async_p implementation. */
4410 linux_nat_is_async_p (struct target_ops
*ops
)
4412 return linux_is_async_p ();
4415 /* target_can_async_p implementation. */
4418 linux_nat_can_async_p (struct target_ops
*ops
)
4420 /* We're always async, unless the user explicitly prevented it with the
4421 "maint set target-async" command. */
4422 return target_async_permitted
;
4426 linux_nat_supports_non_stop (struct target_ops
*self
)
4431 /* to_always_non_stop_p implementation. */
4434 linux_nat_always_non_stop_p (struct target_ops
*self
)
4439 /* True if we want to support multi-process. To be removed when GDB
4440 supports multi-exec. */
4442 int linux_multi_process
= 1;
4445 linux_nat_supports_multi_process (struct target_ops
*self
)
4447 return linux_multi_process
;
4451 linux_nat_supports_disable_randomization (struct target_ops
*self
)
4453 #ifdef HAVE_PERSONALITY
4460 static int async_terminal_is_ours
= 1;
4462 /* target_terminal_inferior implementation.
4464 This is a wrapper around child_terminal_inferior to add async support. */
4467 linux_nat_terminal_inferior (struct target_ops
*self
)
4469 child_terminal_inferior (self
);
4471 /* Calls to target_terminal_*() are meant to be idempotent. */
4472 if (!async_terminal_is_ours
)
4475 async_terminal_is_ours
= 0;
4479 /* target_terminal_ours implementation.
4481 This is a wrapper around child_terminal_ours to add async support (and
4482 implement the target_terminal_ours vs target_terminal_ours_for_output
4483 distinction). child_terminal_ours is currently no different than
4484 child_terminal_ours_for_output.
4485 We leave target_terminal_ours_for_output alone, leaving it to
4486 child_terminal_ours_for_output. */
4489 linux_nat_terminal_ours (struct target_ops
*self
)
4491 /* GDB should never give the terminal to the inferior if the
4492 inferior is running in the background (run&, continue&, etc.),
4493 but claiming it sure should. */
4494 child_terminal_ours (self
);
4496 if (async_terminal_is_ours
)
4499 clear_sigint_trap ();
4500 async_terminal_is_ours
= 1;
4503 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4504 so we notice when any child changes state, and notify the
4505 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4506 above to wait for the arrival of a SIGCHLD. */
4509 sigchld_handler (int signo
)
4511 int old_errno
= errno
;
4513 if (debug_linux_nat
)
4514 ui_file_write_async_safe (gdb_stdlog
,
4515 "sigchld\n", sizeof ("sigchld\n") - 1);
4517 if (signo
== SIGCHLD
4518 && linux_nat_event_pipe
[0] != -1)
4519 async_file_mark (); /* Let the event loop know that there are
4520 events to handle. */
4525 /* Callback registered with the target events file descriptor. */
4528 handle_target_event (int error
, gdb_client_data client_data
)
4530 inferior_event_handler (INF_REG_EVENT
, NULL
);
4533 /* Create/destroy the target events pipe. Returns previous state. */
4536 linux_async_pipe (int enable
)
4538 int previous
= linux_is_async_p ();
4540 if (previous
!= enable
)
4544 /* Block child signals while we create/destroy the pipe, as
4545 their handler writes to it. */
4546 block_child_signals (&prev_mask
);
4550 if (gdb_pipe_cloexec (linux_nat_event_pipe
) == -1)
4551 internal_error (__FILE__
, __LINE__
,
4552 "creating event pipe failed.");
4554 fcntl (linux_nat_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4555 fcntl (linux_nat_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4559 close (linux_nat_event_pipe
[0]);
4560 close (linux_nat_event_pipe
[1]);
4561 linux_nat_event_pipe
[0] = -1;
4562 linux_nat_event_pipe
[1] = -1;
4565 restore_child_signals_mask (&prev_mask
);
4571 /* target_async implementation. */
4574 linux_nat_async (struct target_ops
*ops
, int enable
)
4578 if (!linux_async_pipe (1))
4580 add_file_handler (linux_nat_event_pipe
[0],
4581 handle_target_event
, NULL
);
4582 /* There may be pending events to handle. Tell the event loop
4589 delete_file_handler (linux_nat_event_pipe
[0]);
4590 linux_async_pipe (0);
4595 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4599 linux_nat_stop_lwp (struct lwp_info
*lwp
, void *data
)
4603 if (debug_linux_nat
)
4604 fprintf_unfiltered (gdb_stdlog
,
4605 "LNSL: running -> suspending %s\n",
4606 target_pid_to_str (lwp
->ptid
));
4609 if (lwp
->last_resume_kind
== resume_stop
)
4611 if (debug_linux_nat
)
4612 fprintf_unfiltered (gdb_stdlog
,
4613 "linux-nat: already stopping LWP %ld at "
4615 ptid_get_lwp (lwp
->ptid
));
4619 stop_callback (lwp
, NULL
);
4620 lwp
->last_resume_kind
= resume_stop
;
4624 /* Already known to be stopped; do nothing. */
4626 if (debug_linux_nat
)
4628 if (find_thread_ptid (lwp
->ptid
)->stop_requested
)
4629 fprintf_unfiltered (gdb_stdlog
,
4630 "LNSL: already stopped/stop_requested %s\n",
4631 target_pid_to_str (lwp
->ptid
));
4633 fprintf_unfiltered (gdb_stdlog
,
4634 "LNSL: already stopped/no "
4635 "stop_requested yet %s\n",
4636 target_pid_to_str (lwp
->ptid
));
4643 linux_nat_stop (struct target_ops
*self
, ptid_t ptid
)
4645 iterate_over_lwps (ptid
, linux_nat_stop_lwp
, NULL
);
4649 linux_nat_close (struct target_ops
*self
)
4651 /* Unregister from the event loop. */
4652 if (linux_nat_is_async_p (self
))
4653 linux_nat_async (self
, 0);
4655 if (linux_ops
->to_close
)
4656 linux_ops
->to_close (linux_ops
);
4661 /* When requests are passed down from the linux-nat layer to the
4662 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4663 used. The address space pointer is stored in the inferior object,
4664 but the common code that is passed such ptid can't tell whether
4665 lwpid is a "main" process id or not (it assumes so). We reverse
4666 look up the "main" process id from the lwp here. */
4668 static struct address_space
*
4669 linux_nat_thread_address_space (struct target_ops
*t
, ptid_t ptid
)
4671 struct lwp_info
*lwp
;
4672 struct inferior
*inf
;
4675 if (ptid_get_lwp (ptid
) == 0)
4677 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4679 lwp
= find_lwp_pid (ptid
);
4680 pid
= ptid_get_pid (lwp
->ptid
);
4684 /* A (pid,lwpid,0) ptid. */
4685 pid
= ptid_get_pid (ptid
);
4688 inf
= find_inferior_pid (pid
);
4689 gdb_assert (inf
!= NULL
);
4693 /* Return the cached value of the processor core for thread PTID. */
4696 linux_nat_core_of_thread (struct target_ops
*ops
, ptid_t ptid
)
4698 struct lwp_info
*info
= find_lwp_pid (ptid
);
4705 /* Implementation of to_filesystem_is_local. */
4708 linux_nat_filesystem_is_local (struct target_ops
*ops
)
4710 struct inferior
*inf
= current_inferior ();
4712 if (inf
->fake_pid_p
|| inf
->pid
== 0)
4715 return linux_ns_same (inf
->pid
, LINUX_NS_MNT
);
4718 /* Convert the INF argument passed to a to_fileio_* method
4719 to a process ID suitable for passing to its corresponding
4720 linux_mntns_* function. If INF is non-NULL then the
4721 caller is requesting the filesystem seen by INF. If INF
4722 is NULL then the caller is requesting the filesystem seen
4723 by the GDB. We fall back to GDB's filesystem in the case
4724 that INF is non-NULL but its PID is unknown. */
4727 linux_nat_fileio_pid_of (struct inferior
*inf
)
4729 if (inf
== NULL
|| inf
->fake_pid_p
|| inf
->pid
== 0)
4735 /* Implementation of to_fileio_open. */
4738 linux_nat_fileio_open (struct target_ops
*self
,
4739 struct inferior
*inf
, const char *filename
,
4740 int flags
, int mode
, int warn_if_slow
,
4747 if (fileio_to_host_openflags (flags
, &nat_flags
) == -1
4748 || fileio_to_host_mode (mode
, &nat_mode
) == -1)
4750 *target_errno
= FILEIO_EINVAL
;
4754 fd
= linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf
),
4755 filename
, nat_flags
, nat_mode
);
4757 *target_errno
= host_to_fileio_error (errno
);
4762 /* Implementation of to_fileio_readlink. */
4765 linux_nat_fileio_readlink (struct target_ops
*self
,
4766 struct inferior
*inf
, const char *filename
,
4773 len
= linux_mntns_readlink (linux_nat_fileio_pid_of (inf
),
4774 filename
, buf
, sizeof (buf
));
4777 *target_errno
= host_to_fileio_error (errno
);
4781 ret
= (char *) xmalloc (len
+ 1);
4782 memcpy (ret
, buf
, len
);
4787 /* Implementation of to_fileio_unlink. */
4790 linux_nat_fileio_unlink (struct target_ops
*self
,
4791 struct inferior
*inf
, const char *filename
,
4796 ret
= linux_mntns_unlink (linux_nat_fileio_pid_of (inf
),
4799 *target_errno
= host_to_fileio_error (errno
);
4804 /* Implementation of the to_thread_events method. */
4807 linux_nat_thread_events (struct target_ops
*ops
, int enable
)
4809 report_thread_events
= enable
;
4813 linux_nat_add_target (struct target_ops
*t
)
4815 /* Save the provided single-threaded target. We save this in a separate
4816 variable because another target we've inherited from (e.g. inf-ptrace)
4817 may have saved a pointer to T; we want to use it for the final
4818 process stratum target. */
4819 linux_ops_saved
= *t
;
4820 linux_ops
= &linux_ops_saved
;
4822 /* Override some methods for multithreading. */
4823 t
->to_create_inferior
= linux_nat_create_inferior
;
4824 t
->to_attach
= linux_nat_attach
;
4825 t
->to_detach
= linux_nat_detach
;
4826 t
->to_resume
= linux_nat_resume
;
4827 t
->to_wait
= linux_nat_wait
;
4828 t
->to_pass_signals
= linux_nat_pass_signals
;
4829 t
->to_xfer_partial
= linux_nat_xfer_partial
;
4830 t
->to_kill
= linux_nat_kill
;
4831 t
->to_mourn_inferior
= linux_nat_mourn_inferior
;
4832 t
->to_thread_alive
= linux_nat_thread_alive
;
4833 t
->to_update_thread_list
= linux_nat_update_thread_list
;
4834 t
->to_pid_to_str
= linux_nat_pid_to_str
;
4835 t
->to_thread_name
= linux_nat_thread_name
;
4836 t
->to_has_thread_control
= tc_schedlock
;
4837 t
->to_thread_address_space
= linux_nat_thread_address_space
;
4838 t
->to_stopped_by_watchpoint
= linux_nat_stopped_by_watchpoint
;
4839 t
->to_stopped_data_address
= linux_nat_stopped_data_address
;
4840 t
->to_stopped_by_sw_breakpoint
= linux_nat_stopped_by_sw_breakpoint
;
4841 t
->to_supports_stopped_by_sw_breakpoint
= linux_nat_supports_stopped_by_sw_breakpoint
;
4842 t
->to_stopped_by_hw_breakpoint
= linux_nat_stopped_by_hw_breakpoint
;
4843 t
->to_supports_stopped_by_hw_breakpoint
= linux_nat_supports_stopped_by_hw_breakpoint
;
4844 t
->to_thread_events
= linux_nat_thread_events
;
4846 t
->to_can_async_p
= linux_nat_can_async_p
;
4847 t
->to_is_async_p
= linux_nat_is_async_p
;
4848 t
->to_supports_non_stop
= linux_nat_supports_non_stop
;
4849 t
->to_always_non_stop_p
= linux_nat_always_non_stop_p
;
4850 t
->to_async
= linux_nat_async
;
4851 t
->to_terminal_inferior
= linux_nat_terminal_inferior
;
4852 t
->to_terminal_ours
= linux_nat_terminal_ours
;
4854 super_close
= t
->to_close
;
4855 t
->to_close
= linux_nat_close
;
4857 t
->to_stop
= linux_nat_stop
;
4859 t
->to_supports_multi_process
= linux_nat_supports_multi_process
;
4861 t
->to_supports_disable_randomization
4862 = linux_nat_supports_disable_randomization
;
4864 t
->to_core_of_thread
= linux_nat_core_of_thread
;
4866 t
->to_filesystem_is_local
= linux_nat_filesystem_is_local
;
4867 t
->to_fileio_open
= linux_nat_fileio_open
;
4868 t
->to_fileio_readlink
= linux_nat_fileio_readlink
;
4869 t
->to_fileio_unlink
= linux_nat_fileio_unlink
;
4871 /* We don't change the stratum; this target will sit at
4872 process_stratum and thread_db will set at thread_stratum. This
4873 is a little strange, since this is a multi-threaded-capable
4874 target, but we want to be on the stack below thread_db, and we
4875 also want to be used for single-threaded processes. */
4880 /* Register a method to call whenever a new thread is attached. */
4882 linux_nat_set_new_thread (struct target_ops
*t
,
4883 void (*new_thread
) (struct lwp_info
*))
4885 /* Save the pointer. We only support a single registered instance
4886 of the GNU/Linux native target, so we do not need to map this to
4888 linux_nat_new_thread
= new_thread
;
4891 /* See declaration in linux-nat.h. */
4894 linux_nat_set_new_fork (struct target_ops
*t
,
4895 linux_nat_new_fork_ftype
*new_fork
)
4897 /* Save the pointer. */
4898 linux_nat_new_fork
= new_fork
;
4901 /* See declaration in linux-nat.h. */
4904 linux_nat_set_forget_process (struct target_ops
*t
,
4905 linux_nat_forget_process_ftype
*fn
)
4907 /* Save the pointer. */
4908 linux_nat_forget_process_hook
= fn
;
4911 /* See declaration in linux-nat.h. */
4914 linux_nat_forget_process (pid_t pid
)
4916 if (linux_nat_forget_process_hook
!= NULL
)
4917 linux_nat_forget_process_hook (pid
);
4920 /* Register a method that converts a siginfo object between the layout
4921 that ptrace returns, and the layout in the architecture of the
4924 linux_nat_set_siginfo_fixup (struct target_ops
*t
,
4925 int (*siginfo_fixup
) (siginfo_t
*,
4929 /* Save the pointer. */
4930 linux_nat_siginfo_fixup
= siginfo_fixup
;
4933 /* Register a method to call prior to resuming a thread. */
4936 linux_nat_set_prepare_to_resume (struct target_ops
*t
,
4937 void (*prepare_to_resume
) (struct lwp_info
*))
4939 /* Save the pointer. */
4940 linux_nat_prepare_to_resume
= prepare_to_resume
;
4943 /* See linux-nat.h. */
4946 linux_nat_get_siginfo (ptid_t ptid
, siginfo_t
*siginfo
)
4950 pid
= ptid_get_lwp (ptid
);
4952 pid
= ptid_get_pid (ptid
);
4955 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, siginfo
);
4958 memset (siginfo
, 0, sizeof (*siginfo
));
4964 /* See nat/linux-nat.h. */
4967 current_lwp_ptid (void)
4969 gdb_assert (ptid_lwp_p (inferior_ptid
));
4970 return inferior_ptid
;
4973 /* Provide a prototype to silence -Wmissing-prototypes. */
4974 extern initialize_file_ftype _initialize_linux_nat
;
4977 _initialize_linux_nat (void)
4979 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance
,
4980 &debug_linux_nat
, _("\
4981 Set debugging of GNU/Linux lwp module."), _("\
4982 Show debugging of GNU/Linux lwp module."), _("\
4983 Enables printf debugging output."),
4985 show_debug_linux_nat
,
4986 &setdebuglist
, &showdebuglist
);
4988 add_setshow_boolean_cmd ("linux-namespaces", class_maintenance
,
4989 &debug_linux_namespaces
, _("\
4990 Set debugging of GNU/Linux namespaces module."), _("\
4991 Show debugging of GNU/Linux namespaces module."), _("\
4992 Enables printf debugging output."),
4995 &setdebuglist
, &showdebuglist
);
4997 /* Save this mask as the default. */
4998 sigprocmask (SIG_SETMASK
, NULL
, &normal_mask
);
5000 /* Install a SIGCHLD handler. */
5001 sigchld_action
.sa_handler
= sigchld_handler
;
5002 sigemptyset (&sigchld_action
.sa_mask
);
5003 sigchld_action
.sa_flags
= SA_RESTART
;
5005 /* Make it the default. */
5006 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
5008 /* Make sure we don't block SIGCHLD during a sigsuspend. */
5009 sigprocmask (SIG_SETMASK
, NULL
, &suspend_mask
);
5010 sigdelset (&suspend_mask
, SIGCHLD
);
5012 sigemptyset (&blocked_mask
);
5014 lwp_lwpid_htab_create ();
5018 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
5019 the GNU/Linux Threads library and therefore doesn't really belong
5022 /* Return the set of signals used by the threads library in *SET. */
5025 lin_thread_get_thread_signals (sigset_t
*set
)
5029 /* NPTL reserves the first two RT signals, but does not provide any
5030 way for the debugger to query the signal numbers - fortunately
5031 they don't change. */
5032 sigaddset (set
, __SIGRTMIN
);
5033 sigaddset (set
, __SIGRTMIN
+ 1);