1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001-2016 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "nat/linux-nat.h"
25 #include "nat/linux-waitpid.h"
28 #include <sys/syscall.h>
29 #include "nat/gdb_ptrace.h"
30 #include "linux-nat.h"
31 #include "nat/linux-ptrace.h"
32 #include "nat/linux-procfs.h"
33 #include "nat/linux-personality.h"
34 #include "linux-fork.h"
35 #include "gdbthread.h"
39 #include "inf-child.h"
40 #include "inf-ptrace.h"
42 #include <sys/procfs.h> /* for elf_gregset etc. */
43 #include "elf-bfd.h" /* for elfcore_write_* */
44 #include "gregset.h" /* for gregset */
45 #include "gdbcore.h" /* for get_exec_file */
46 #include <ctype.h> /* for isdigit */
47 #include <sys/stat.h> /* for struct stat */
48 #include <fcntl.h> /* for O_RDONLY */
50 #include "event-loop.h"
51 #include "event-top.h"
53 #include <sys/types.h>
55 #include "xml-support.h"
58 #include "nat/linux-osdata.h"
59 #include "linux-tdep.h"
62 #include "tracepoint.h"
64 #include "target-descriptions.h"
65 #include "filestuff.h"
67 #include "nat/linux-namespaces.h"
71 #define SPUFS_MAGIC 0x23c9b64e
74 /* This comment documents high-level logic of this file.
76 Waiting for events in sync mode
77 ===============================
79 When waiting for an event in a specific thread, we just use waitpid,
80 passing the specific pid, and not passing WNOHANG.
82 When waiting for an event in all threads, waitpid is not quite good:
84 - If the thread group leader exits while other threads in the thread
85 group still exist, waitpid(TGID, ...) hangs. That waitpid won't
86 return an exit status until the other threads in the group are
89 - When a non-leader thread execs, that thread just vanishes without
90 reporting an exit (so we'd hang if we waited for it explicitly in
91 that case). The exec event is instead reported to the TGID pid.
93 The solution is to always use -1 and WNOHANG, together with
96 First, we use non-blocking waitpid to check for events. If nothing is
97 found, we use sigsuspend to wait for SIGCHLD. When SIGCHLD arrives,
98 it means something happened to a child process. As soon as we know
99 there's an event, we get back to calling nonblocking waitpid.
101 Note that SIGCHLD should be blocked between waitpid and sigsuspend
102 calls, so that we don't miss a signal. If SIGCHLD arrives in between,
103 when it's blocked, the signal becomes pending and sigsuspend
104 immediately notices it and returns.
106 Waiting for events in async mode (TARGET_WNOHANG)
107 =================================================
109 In async mode, GDB should always be ready to handle both user input
110 and target events, so neither blocking waitpid nor sigsuspend are
111 viable options. Instead, we should asynchronously notify the GDB main
112 event loop whenever there's an unprocessed event from the target. We
113 detect asynchronous target events by handling SIGCHLD signals. To
114 notify the event loop about target events, the self-pipe trick is used
115 --- a pipe is registered as waitable event source in the event loop,
116 the event loop select/poll's on the read end of this pipe (as well on
117 other event sources, e.g., stdin), and the SIGCHLD handler writes a
118 byte to this pipe. This is more portable than relying on
119 pselect/ppoll, since on kernels that lack those syscalls, libc
120 emulates them with select/poll+sigprocmask, and that is racy
121 (a.k.a. plain broken).
123 Obviously, if we fail to notify the event loop if there's a target
124 event, it's bad. OTOH, if we notify the event loop when there's no
125 event from the target, linux_nat_wait will detect that there's no real
126 event to report, and return event of type TARGET_WAITKIND_IGNORE.
127 This is mostly harmless, but it will waste time and is better avoided.
129 The main design point is that every time GDB is outside linux-nat.c,
130 we have a SIGCHLD handler installed that is called when something
131 happens to the target and notifies the GDB event loop. Whenever GDB
132 core decides to handle the event, and calls into linux-nat.c, we
133 process things as in sync mode, except that the we never block in
136 While processing an event, we may end up momentarily blocked in
137 waitpid calls. Those waitpid calls, while blocking, are guarantied to
138 return quickly. E.g., in all-stop mode, before reporting to the core
139 that an LWP hit a breakpoint, all LWPs are stopped by sending them
140 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
141 Note that this is different from blocking indefinitely waiting for the
142 next event --- here, we're already handling an event.
147 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
148 signal is not entirely significant; we just need for a signal to be delivered,
149 so that we can intercept it. SIGSTOP's advantage is that it can not be
150 blocked. A disadvantage is that it is not a real-time signal, so it can only
151 be queued once; we do not keep track of other sources of SIGSTOP.
153 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
154 use them, because they have special behavior when the signal is generated -
155 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
156 kills the entire thread group.
158 A delivered SIGSTOP would stop the entire thread group, not just the thread we
159 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
160 cancel it (by PTRACE_CONT without passing SIGSTOP).
162 We could use a real-time signal instead. This would solve those problems; we
163 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
164 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
165 generates it, and there are races with trying to find a signal that is not
171 The case of a thread group (process) with 3 or more threads, and a
172 thread other than the leader execs is worth detailing:
174 On an exec, the Linux kernel destroys all threads except the execing
175 one in the thread group, and resets the execing thread's tid to the
176 tgid. No exit notification is sent for the execing thread -- from the
177 ptracer's perspective, it appears as though the execing thread just
178 vanishes. Until we reap all other threads except the leader and the
179 execing thread, the leader will be zombie, and the execing thread will
180 be in `D (disc sleep)' state. As soon as all other threads are
181 reaped, the execing thread changes its tid to the tgid, and the
182 previous (zombie) leader vanishes, giving place to the "new"
186 #define O_LARGEFILE 0
189 /* Does the current host support PTRACE_GETREGSET? */
190 enum tribool have_ptrace_getregset
= TRIBOOL_UNKNOWN
;
192 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
193 the use of the multi-threaded target. */
194 static struct target_ops
*linux_ops
;
195 static struct target_ops linux_ops_saved
;
197 /* The method to call, if any, when a new thread is attached. */
198 static void (*linux_nat_new_thread
) (struct lwp_info
*);
200 /* The method to call, if any, when a new fork is attached. */
201 static linux_nat_new_fork_ftype
*linux_nat_new_fork
;
203 /* The method to call, if any, when a process is no longer
205 static linux_nat_forget_process_ftype
*linux_nat_forget_process_hook
;
207 /* Hook to call prior to resuming a thread. */
208 static void (*linux_nat_prepare_to_resume
) (struct lwp_info
*);
210 /* The method to call, if any, when the siginfo object needs to be
211 converted between the layout returned by ptrace, and the layout in
212 the architecture of the inferior. */
213 static int (*linux_nat_siginfo_fixup
) (siginfo_t
*,
217 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
218 Called by our to_xfer_partial. */
219 static target_xfer_partial_ftype
*super_xfer_partial
;
221 /* The saved to_close method, inherited from inf-ptrace.c.
222 Called by our to_close. */
223 static void (*super_close
) (struct target_ops
*);
225 static unsigned int debug_linux_nat
;
227 show_debug_linux_nat (struct ui_file
*file
, int from_tty
,
228 struct cmd_list_element
*c
, const char *value
)
230 fprintf_filtered (file
, _("Debugging of GNU/Linux lwp module is %s.\n"),
234 struct simple_pid_list
238 struct simple_pid_list
*next
;
240 struct simple_pid_list
*stopped_pids
;
242 /* Whether target_thread_events is in effect. */
243 static int report_thread_events
;
245 /* Async mode support. */
247 /* The read/write ends of the pipe registered as waitable file in the
249 static int linux_nat_event_pipe
[2] = { -1, -1 };
251 /* True if we're currently in async mode. */
252 #define linux_is_async_p() (linux_nat_event_pipe[0] != -1)
254 /* Flush the event pipe. */
257 async_file_flush (void)
264 ret
= read (linux_nat_event_pipe
[0], &buf
, 1);
266 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
269 /* Put something (anything, doesn't matter what, or how much) in event
270 pipe, so that the select/poll in the event-loop realizes we have
271 something to process. */
274 async_file_mark (void)
278 /* It doesn't really matter what the pipe contains, as long we end
279 up with something in it. Might as well flush the previous
285 ret
= write (linux_nat_event_pipe
[1], "+", 1);
287 while (ret
== -1 && errno
== EINTR
);
289 /* Ignore EAGAIN. If the pipe is full, the event loop will already
290 be awakened anyway. */
293 static int kill_lwp (int lwpid
, int signo
);
295 static int stop_callback (struct lwp_info
*lp
, void *data
);
296 static int resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
);
298 static void block_child_signals (sigset_t
*prev_mask
);
299 static void restore_child_signals_mask (sigset_t
*prev_mask
);
302 static struct lwp_info
*add_lwp (ptid_t ptid
);
303 static void purge_lwp_list (int pid
);
304 static void delete_lwp (ptid_t ptid
);
305 static struct lwp_info
*find_lwp_pid (ptid_t ptid
);
307 static int lwp_status_pending_p (struct lwp_info
*lp
);
309 static int sigtrap_is_event (int status
);
310 static int (*linux_nat_status_is_event
) (int status
) = sigtrap_is_event
;
312 static void save_stop_reason (struct lwp_info
*lp
);
317 /* See nat/linux-nat.h. */
320 ptid_of_lwp (struct lwp_info
*lwp
)
325 /* See nat/linux-nat.h. */
328 lwp_set_arch_private_info (struct lwp_info
*lwp
,
329 struct arch_lwp_info
*info
)
331 lwp
->arch_private
= info
;
334 /* See nat/linux-nat.h. */
336 struct arch_lwp_info
*
337 lwp_arch_private_info (struct lwp_info
*lwp
)
339 return lwp
->arch_private
;
342 /* See nat/linux-nat.h. */
345 lwp_is_stopped (struct lwp_info
*lwp
)
350 /* See nat/linux-nat.h. */
352 enum target_stop_reason
353 lwp_stop_reason (struct lwp_info
*lwp
)
355 return lwp
->stop_reason
;
359 /* Trivial list manipulation functions to keep track of a list of
360 new stopped processes. */
362 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
364 struct simple_pid_list
*new_pid
= XNEW (struct simple_pid_list
);
367 new_pid
->status
= status
;
368 new_pid
->next
= *listp
;
373 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *statusp
)
375 struct simple_pid_list
**p
;
377 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
378 if ((*p
)->pid
== pid
)
380 struct simple_pid_list
*next
= (*p
)->next
;
382 *statusp
= (*p
)->status
;
390 /* Return the ptrace options that we want to try to enable. */
393 linux_nat_ptrace_options (int attached
)
398 options
|= PTRACE_O_EXITKILL
;
400 options
|= (PTRACE_O_TRACESYSGOOD
401 | PTRACE_O_TRACEVFORKDONE
402 | PTRACE_O_TRACEVFORK
404 | PTRACE_O_TRACEEXEC
);
409 /* Initialize ptrace warnings and check for supported ptrace
412 ATTACHED should be nonzero iff we attached to the inferior. */
415 linux_init_ptrace (pid_t pid
, int attached
)
417 int options
= linux_nat_ptrace_options (attached
);
419 linux_enable_event_reporting (pid
, options
);
420 linux_ptrace_init_warnings ();
424 linux_child_post_attach (struct target_ops
*self
, int pid
)
426 linux_init_ptrace (pid
, 1);
430 linux_child_post_startup_inferior (struct target_ops
*self
, ptid_t ptid
)
432 linux_init_ptrace (ptid_get_pid (ptid
), 0);
435 /* Return the number of known LWPs in the tgid given by PID. */
443 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
444 if (ptid_get_pid (lp
->ptid
) == pid
)
450 /* Call delete_lwp with prototype compatible for make_cleanup. */
453 delete_lwp_cleanup (void *lp_voidp
)
455 struct lwp_info
*lp
= (struct lwp_info
*) lp_voidp
;
457 delete_lwp (lp
->ptid
);
460 /* Target hook for follow_fork. On entry inferior_ptid must be the
461 ptid of the followed inferior. At return, inferior_ptid will be
465 linux_child_follow_fork (struct target_ops
*ops
, int follow_child
,
470 struct lwp_info
*child_lp
= NULL
;
471 int status
= W_STOPCODE (0);
472 struct cleanup
*old_chain
;
474 ptid_t parent_ptid
, child_ptid
;
475 int parent_pid
, child_pid
;
477 has_vforked
= (inferior_thread ()->pending_follow
.kind
478 == TARGET_WAITKIND_VFORKED
);
479 parent_ptid
= inferior_ptid
;
480 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
481 parent_pid
= ptid_get_lwp (parent_ptid
);
482 child_pid
= ptid_get_lwp (child_ptid
);
484 /* We're already attached to the parent, by default. */
485 old_chain
= save_inferior_ptid ();
486 inferior_ptid
= child_ptid
;
487 child_lp
= add_lwp (inferior_ptid
);
488 child_lp
->stopped
= 1;
489 child_lp
->last_resume_kind
= resume_stop
;
491 /* Detach new forked process? */
494 make_cleanup (delete_lwp_cleanup
, child_lp
);
496 if (linux_nat_prepare_to_resume
!= NULL
)
497 linux_nat_prepare_to_resume (child_lp
);
499 /* When debugging an inferior in an architecture that supports
500 hardware single stepping on a kernel without commit
501 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child
502 process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits
503 set if the parent process had them set.
504 To work around this, single step the child process
505 once before detaching to clear the flags. */
507 if (!gdbarch_software_single_step_p (target_thread_architecture
510 linux_disable_event_reporting (child_pid
);
511 if (ptrace (PTRACE_SINGLESTEP
, child_pid
, 0, 0) < 0)
512 perror_with_name (_("Couldn't do single step"));
513 if (my_waitpid (child_pid
, &status
, 0) < 0)
514 perror_with_name (_("Couldn't wait vfork process"));
517 if (WIFSTOPPED (status
))
521 signo
= WSTOPSIG (status
);
523 && !signal_pass_state (gdb_signal_from_host (signo
)))
525 ptrace (PTRACE_DETACH
, child_pid
, 0, signo
);
528 /* Resets value of inferior_ptid to parent ptid. */
529 do_cleanups (old_chain
);
533 /* Let the thread_db layer learn about this new process. */
534 check_for_thread_db ();
537 do_cleanups (old_chain
);
541 struct lwp_info
*parent_lp
;
543 parent_lp
= find_lwp_pid (parent_ptid
);
544 gdb_assert (linux_supports_tracefork () >= 0);
546 if (linux_supports_tracevforkdone ())
549 fprintf_unfiltered (gdb_stdlog
,
550 "LCFF: waiting for VFORK_DONE on %d\n",
552 parent_lp
->stopped
= 1;
554 /* We'll handle the VFORK_DONE event like any other
555 event, in target_wait. */
559 /* We can't insert breakpoints until the child has
560 finished with the shared memory region. We need to
561 wait until that happens. Ideal would be to just
563 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
564 - waitpid (parent_pid, &status, __WALL);
565 However, most architectures can't handle a syscall
566 being traced on the way out if it wasn't traced on
569 We might also think to loop, continuing the child
570 until it exits or gets a SIGTRAP. One problem is
571 that the child might call ptrace with PTRACE_TRACEME.
573 There's no simple and reliable way to figure out when
574 the vforked child will be done with its copy of the
575 shared memory. We could step it out of the syscall,
576 two instructions, let it go, and then single-step the
577 parent once. When we have hardware single-step, this
578 would work; with software single-step it could still
579 be made to work but we'd have to be able to insert
580 single-step breakpoints in the child, and we'd have
581 to insert -just- the single-step breakpoint in the
582 parent. Very awkward.
584 In the end, the best we can do is to make sure it
585 runs for a little while. Hopefully it will be out of
586 range of any breakpoints we reinsert. Usually this
587 is only the single-step breakpoint at vfork's return
591 fprintf_unfiltered (gdb_stdlog
,
592 "LCFF: no VFORK_DONE "
593 "support, sleeping a bit\n");
597 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
598 and leave it pending. The next linux_nat_resume call
599 will notice a pending event, and bypasses actually
600 resuming the inferior. */
601 parent_lp
->status
= 0;
602 parent_lp
->waitstatus
.kind
= TARGET_WAITKIND_VFORK_DONE
;
603 parent_lp
->stopped
= 1;
605 /* If we're in async mode, need to tell the event loop
606 there's something here to process. */
607 if (target_is_async_p ())
614 struct lwp_info
*child_lp
;
616 child_lp
= add_lwp (inferior_ptid
);
617 child_lp
->stopped
= 1;
618 child_lp
->last_resume_kind
= resume_stop
;
620 /* Let the thread_db layer learn about this new process. */
621 check_for_thread_db ();
629 linux_child_insert_fork_catchpoint (struct target_ops
*self
, int pid
)
631 return !linux_supports_tracefork ();
635 linux_child_remove_fork_catchpoint (struct target_ops
*self
, int pid
)
641 linux_child_insert_vfork_catchpoint (struct target_ops
*self
, int pid
)
643 return !linux_supports_tracefork ();
647 linux_child_remove_vfork_catchpoint (struct target_ops
*self
, int pid
)
653 linux_child_insert_exec_catchpoint (struct target_ops
*self
, int pid
)
655 return !linux_supports_tracefork ();
659 linux_child_remove_exec_catchpoint (struct target_ops
*self
, int pid
)
665 linux_child_set_syscall_catchpoint (struct target_ops
*self
,
666 int pid
, int needed
, int any_count
,
667 int table_size
, int *table
)
669 if (!linux_supports_tracesysgood ())
672 /* On GNU/Linux, we ignore the arguments. It means that we only
673 enable the syscall catchpoints, but do not disable them.
675 Also, we do not use the `table' information because we do not
676 filter system calls here. We let GDB do the logic for us. */
680 /* List of known LWPs, keyed by LWP PID. This speeds up the common
681 case of mapping a PID returned from the kernel to our corresponding
682 lwp_info data structure. */
683 static htab_t lwp_lwpid_htab
;
685 /* Calculate a hash from a lwp_info's LWP PID. */
688 lwp_info_hash (const void *ap
)
690 const struct lwp_info
*lp
= (struct lwp_info
*) ap
;
691 pid_t pid
= ptid_get_lwp (lp
->ptid
);
693 return iterative_hash_object (pid
, 0);
696 /* Equality function for the lwp_info hash table. Compares the LWP's
700 lwp_lwpid_htab_eq (const void *a
, const void *b
)
702 const struct lwp_info
*entry
= (const struct lwp_info
*) a
;
703 const struct lwp_info
*element
= (const struct lwp_info
*) b
;
705 return ptid_get_lwp (entry
->ptid
) == ptid_get_lwp (element
->ptid
);
708 /* Create the lwp_lwpid_htab hash table. */
711 lwp_lwpid_htab_create (void)
713 lwp_lwpid_htab
= htab_create (100, lwp_info_hash
, lwp_lwpid_htab_eq
, NULL
);
716 /* Add LP to the hash table. */
719 lwp_lwpid_htab_add_lwp (struct lwp_info
*lp
)
723 slot
= htab_find_slot (lwp_lwpid_htab
, lp
, INSERT
);
724 gdb_assert (slot
!= NULL
&& *slot
== NULL
);
728 /* Head of doubly-linked list of known LWPs. Sorted by reverse
729 creation order. This order is assumed in some cases. E.g.,
730 reaping status after killing alls lwps of a process: the leader LWP
731 must be reaped last. */
732 struct lwp_info
*lwp_list
;
734 /* Add LP to sorted-by-reverse-creation-order doubly-linked list. */
737 lwp_list_add (struct lwp_info
*lp
)
740 if (lwp_list
!= NULL
)
745 /* Remove LP from sorted-by-reverse-creation-order doubly-linked
749 lwp_list_remove (struct lwp_info
*lp
)
751 /* Remove from sorted-by-creation-order list. */
752 if (lp
->next
!= NULL
)
753 lp
->next
->prev
= lp
->prev
;
754 if (lp
->prev
!= NULL
)
755 lp
->prev
->next
= lp
->next
;
762 /* Original signal mask. */
763 static sigset_t normal_mask
;
765 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
766 _initialize_linux_nat. */
767 static sigset_t suspend_mask
;
769 /* Signals to block to make that sigsuspend work. */
770 static sigset_t blocked_mask
;
772 /* SIGCHLD action. */
773 struct sigaction sigchld_action
;
775 /* Block child signals (SIGCHLD and linux threads signals), and store
776 the previous mask in PREV_MASK. */
779 block_child_signals (sigset_t
*prev_mask
)
781 /* Make sure SIGCHLD is blocked. */
782 if (!sigismember (&blocked_mask
, SIGCHLD
))
783 sigaddset (&blocked_mask
, SIGCHLD
);
785 sigprocmask (SIG_BLOCK
, &blocked_mask
, prev_mask
);
788 /* Restore child signals mask, previously returned by
789 block_child_signals. */
792 restore_child_signals_mask (sigset_t
*prev_mask
)
794 sigprocmask (SIG_SETMASK
, prev_mask
, NULL
);
797 /* Mask of signals to pass directly to the inferior. */
798 static sigset_t pass_mask
;
800 /* Update signals to pass to the inferior. */
802 linux_nat_pass_signals (struct target_ops
*self
,
803 int numsigs
, unsigned char *pass_signals
)
807 sigemptyset (&pass_mask
);
809 for (signo
= 1; signo
< NSIG
; signo
++)
811 int target_signo
= gdb_signal_from_host (signo
);
812 if (target_signo
< numsigs
&& pass_signals
[target_signo
])
813 sigaddset (&pass_mask
, signo
);
819 /* Prototypes for local functions. */
820 static int stop_wait_callback (struct lwp_info
*lp
, void *data
);
821 static char *linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
);
822 static int resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
);
826 /* Destroy and free LP. */
829 lwp_free (struct lwp_info
*lp
)
831 xfree (lp
->arch_private
);
835 /* Traversal function for purge_lwp_list. */
838 lwp_lwpid_htab_remove_pid (void **slot
, void *info
)
840 struct lwp_info
*lp
= (struct lwp_info
*) *slot
;
841 int pid
= *(int *) info
;
843 if (ptid_get_pid (lp
->ptid
) == pid
)
845 htab_clear_slot (lwp_lwpid_htab
, slot
);
846 lwp_list_remove (lp
);
853 /* Remove all LWPs belong to PID from the lwp list. */
856 purge_lwp_list (int pid
)
858 htab_traverse_noresize (lwp_lwpid_htab
, lwp_lwpid_htab_remove_pid
, &pid
);
861 /* Add the LWP specified by PTID to the list. PTID is the first LWP
862 in the process. Return a pointer to the structure describing the
865 This differs from add_lwp in that we don't let the arch specific
866 bits know about this new thread. Current clients of this callback
867 take the opportunity to install watchpoints in the new thread, and
868 we shouldn't do that for the first thread. If we're spawning a
869 child ("run"), the thread executes the shell wrapper first, and we
870 shouldn't touch it until it execs the program we want to debug.
871 For "attach", it'd be okay to call the callback, but it's not
872 necessary, because watchpoints can't yet have been inserted into
875 static struct lwp_info
*
876 add_initial_lwp (ptid_t ptid
)
880 gdb_assert (ptid_lwp_p (ptid
));
882 lp
= XNEW (struct lwp_info
);
884 memset (lp
, 0, sizeof (struct lwp_info
));
886 lp
->last_resume_kind
= resume_continue
;
887 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
892 /* Add to sorted-by-reverse-creation-order list. */
895 /* Add to keyed-by-pid htab. */
896 lwp_lwpid_htab_add_lwp (lp
);
901 /* Add the LWP specified by PID to the list. Return a pointer to the
902 structure describing the new LWP. The LWP should already be
905 static struct lwp_info
*
906 add_lwp (ptid_t ptid
)
910 lp
= add_initial_lwp (ptid
);
912 /* Let the arch specific bits know about this new thread. Current
913 clients of this callback take the opportunity to install
914 watchpoints in the new thread. We don't do this for the first
915 thread though. See add_initial_lwp. */
916 if (linux_nat_new_thread
!= NULL
)
917 linux_nat_new_thread (lp
);
922 /* Remove the LWP specified by PID from the list. */
925 delete_lwp (ptid_t ptid
)
929 struct lwp_info dummy
;
932 slot
= htab_find_slot (lwp_lwpid_htab
, &dummy
, NO_INSERT
);
936 lp
= *(struct lwp_info
**) slot
;
937 gdb_assert (lp
!= NULL
);
939 htab_clear_slot (lwp_lwpid_htab
, slot
);
941 /* Remove from sorted-by-creation-order list. */
942 lwp_list_remove (lp
);
948 /* Return a pointer to the structure describing the LWP corresponding
949 to PID. If no corresponding LWP could be found, return NULL. */
951 static struct lwp_info
*
952 find_lwp_pid (ptid_t ptid
)
956 struct lwp_info dummy
;
958 if (ptid_lwp_p (ptid
))
959 lwp
= ptid_get_lwp (ptid
);
961 lwp
= ptid_get_pid (ptid
);
963 dummy
.ptid
= ptid_build (0, lwp
, 0);
964 lp
= (struct lwp_info
*) htab_find (lwp_lwpid_htab
, &dummy
);
968 /* See nat/linux-nat.h. */
971 iterate_over_lwps (ptid_t filter
,
972 iterate_over_lwps_ftype callback
,
975 struct lwp_info
*lp
, *lpnext
;
977 for (lp
= lwp_list
; lp
; lp
= lpnext
)
981 if (ptid_match (lp
->ptid
, filter
))
983 if ((*callback
) (lp
, data
) != 0)
991 /* Update our internal state when changing from one checkpoint to
992 another indicated by NEW_PTID. We can only switch single-threaded
993 applications, so we only create one new LWP, and the previous list
997 linux_nat_switch_fork (ptid_t new_ptid
)
1001 purge_lwp_list (ptid_get_pid (inferior_ptid
));
1003 lp
= add_lwp (new_ptid
);
1006 /* This changes the thread's ptid while preserving the gdb thread
1007 num. Also changes the inferior pid, while preserving the
1009 thread_change_ptid (inferior_ptid
, new_ptid
);
1011 /* We've just told GDB core that the thread changed target id, but,
1012 in fact, it really is a different thread, with different register
1014 registers_changed ();
1017 /* Handle the exit of a single thread LP. */
1020 exit_lwp (struct lwp_info
*lp
)
1022 struct thread_info
*th
= find_thread_ptid (lp
->ptid
);
1026 if (print_thread_events
)
1027 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp
->ptid
));
1029 delete_thread (lp
->ptid
);
1032 delete_lwp (lp
->ptid
);
1035 /* Wait for the LWP specified by LP, which we have just attached to.
1036 Returns a wait status for that LWP, to cache. */
1039 linux_nat_post_attach_wait (ptid_t ptid
, int first
, int *signalled
)
1041 pid_t new_pid
, pid
= ptid_get_lwp (ptid
);
1044 if (linux_proc_pid_is_stopped (pid
))
1046 if (debug_linux_nat
)
1047 fprintf_unfiltered (gdb_stdlog
,
1048 "LNPAW: Attaching to a stopped process\n");
1050 /* The process is definitely stopped. It is in a job control
1051 stop, unless the kernel predates the TASK_STOPPED /
1052 TASK_TRACED distinction, in which case it might be in a
1053 ptrace stop. Make sure it is in a ptrace stop; from there we
1054 can kill it, signal it, et cetera.
1056 First make sure there is a pending SIGSTOP. Since we are
1057 already attached, the process can not transition from stopped
1058 to running without a PTRACE_CONT; so we know this signal will
1059 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1060 probably already in the queue (unless this kernel is old
1061 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1062 is not an RT signal, it can only be queued once. */
1063 kill_lwp (pid
, SIGSTOP
);
1065 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1066 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1067 ptrace (PTRACE_CONT
, pid
, 0, 0);
1070 /* Make sure the initial process is stopped. The user-level threads
1071 layer might want to poke around in the inferior, and that won't
1072 work if things haven't stabilized yet. */
1073 new_pid
= my_waitpid (pid
, &status
, __WALL
);
1074 gdb_assert (pid
== new_pid
);
1076 if (!WIFSTOPPED (status
))
1078 /* The pid we tried to attach has apparently just exited. */
1079 if (debug_linux_nat
)
1080 fprintf_unfiltered (gdb_stdlog
, "LNPAW: Failed to stop %d: %s",
1081 pid
, status_to_str (status
));
1085 if (WSTOPSIG (status
) != SIGSTOP
)
1088 if (debug_linux_nat
)
1089 fprintf_unfiltered (gdb_stdlog
,
1090 "LNPAW: Received %s after attaching\n",
1091 status_to_str (status
));
1098 linux_nat_create_inferior (struct target_ops
*ops
,
1099 char *exec_file
, char *allargs
, char **env
,
1102 struct cleanup
*restore_personality
1103 = maybe_disable_address_space_randomization (disable_randomization
);
1105 /* The fork_child mechanism is synchronous and calls target_wait, so
1106 we have to mask the async mode. */
1108 /* Make sure we report all signals during startup. */
1109 linux_nat_pass_signals (ops
, 0, NULL
);
1111 linux_ops
->to_create_inferior (ops
, exec_file
, allargs
, env
, from_tty
);
1113 do_cleanups (restore_personality
);
1116 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
1117 already attached. Returns true if a new LWP is found, false
1121 attach_proc_task_lwp_callback (ptid_t ptid
)
1123 struct lwp_info
*lp
;
1125 /* Ignore LWPs we're already attached to. */
1126 lp
= find_lwp_pid (ptid
);
1129 int lwpid
= ptid_get_lwp (ptid
);
1131 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) < 0)
1135 /* Be quiet if we simply raced with the thread exiting.
1136 EPERM is returned if the thread's task still exists, and
1137 is marked as exited or zombie, as well as other
1138 conditions, so in that case, confirm the status in
1139 /proc/PID/status. */
1141 || (err
== EPERM
&& linux_proc_pid_is_gone (lwpid
)))
1143 if (debug_linux_nat
)
1145 fprintf_unfiltered (gdb_stdlog
,
1146 "Cannot attach to lwp %d: "
1147 "thread is gone (%d: %s)\n",
1148 lwpid
, err
, safe_strerror (err
));
1153 warning (_("Cannot attach to lwp %d: %s"),
1155 linux_ptrace_attach_fail_reason_string (ptid
,
1161 if (debug_linux_nat
)
1162 fprintf_unfiltered (gdb_stdlog
,
1163 "PTRACE_ATTACH %s, 0, 0 (OK)\n",
1164 target_pid_to_str (ptid
));
1166 lp
= add_lwp (ptid
);
1168 /* The next time we wait for this LWP we'll see a SIGSTOP as
1169 PTRACE_ATTACH brings it to a halt. */
1172 /* We need to wait for a stop before being able to make the
1173 next ptrace call on this LWP. */
1174 lp
->must_set_ptrace_flags
= 1;
1176 /* So that wait collects the SIGSTOP. */
1179 /* Also add the LWP to gdb's thread list, in case a
1180 matching libthread_db is not found (or the process uses
1182 add_thread (lp
->ptid
);
1183 set_running (lp
->ptid
, 1);
1184 set_executing (lp
->ptid
, 1);
1193 linux_nat_attach (struct target_ops
*ops
, const char *args
, int from_tty
)
1195 struct lwp_info
*lp
;
1199 /* Make sure we report all signals during attach. */
1200 linux_nat_pass_signals (ops
, 0, NULL
);
1204 linux_ops
->to_attach (ops
, args
, from_tty
);
1206 CATCH (ex
, RETURN_MASK_ERROR
)
1208 pid_t pid
= parse_pid_to_attach (args
);
1209 struct buffer buffer
;
1210 char *message
, *buffer_s
;
1212 message
= xstrdup (ex
.message
);
1213 make_cleanup (xfree
, message
);
1215 buffer_init (&buffer
);
1216 linux_ptrace_attach_fail_reason (pid
, &buffer
);
1218 buffer_grow_str0 (&buffer
, "");
1219 buffer_s
= buffer_finish (&buffer
);
1220 make_cleanup (xfree
, buffer_s
);
1222 if (*buffer_s
!= '\0')
1223 throw_error (ex
.error
, "warning: %s\n%s", buffer_s
, message
);
1225 throw_error (ex
.error
, "%s", message
);
1229 /* The ptrace base target adds the main thread with (pid,0,0)
1230 format. Decorate it with lwp info. */
1231 ptid
= ptid_build (ptid_get_pid (inferior_ptid
),
1232 ptid_get_pid (inferior_ptid
),
1234 thread_change_ptid (inferior_ptid
, ptid
);
1236 /* Add the initial process as the first LWP to the list. */
1237 lp
= add_initial_lwp (ptid
);
1239 status
= linux_nat_post_attach_wait (lp
->ptid
, 1, &lp
->signalled
);
1240 if (!WIFSTOPPED (status
))
1242 if (WIFEXITED (status
))
1244 int exit_code
= WEXITSTATUS (status
);
1246 target_terminal_ours ();
1247 target_mourn_inferior ();
1249 error (_("Unable to attach: program exited normally."));
1251 error (_("Unable to attach: program exited with code %d."),
1254 else if (WIFSIGNALED (status
))
1256 enum gdb_signal signo
;
1258 target_terminal_ours ();
1259 target_mourn_inferior ();
1261 signo
= gdb_signal_from_host (WTERMSIG (status
));
1262 error (_("Unable to attach: program terminated with signal "
1264 gdb_signal_to_name (signo
),
1265 gdb_signal_to_string (signo
));
1268 internal_error (__FILE__
, __LINE__
,
1269 _("unexpected status %d for PID %ld"),
1270 status
, (long) ptid_get_lwp (ptid
));
1275 /* Save the wait status to report later. */
1277 if (debug_linux_nat
)
1278 fprintf_unfiltered (gdb_stdlog
,
1279 "LNA: waitpid %ld, saving status %s\n",
1280 (long) ptid_get_pid (lp
->ptid
), status_to_str (status
));
1282 lp
->status
= status
;
1284 /* We must attach to every LWP. If /proc is mounted, use that to
1285 find them now. The inferior may be using raw clone instead of
1286 using pthreads. But even if it is using pthreads, thread_db
1287 walks structures in the inferior's address space to find the list
1288 of threads/LWPs, and those structures may well be corrupted.
1289 Note that once thread_db is loaded, we'll still use it to list
1290 threads and associate pthread info with each LWP. */
1291 linux_proc_attach_tgid_threads (ptid_get_pid (lp
->ptid
),
1292 attach_proc_task_lwp_callback
);
1294 if (target_can_async_p ())
1298 /* Get pending status of LP. */
1300 get_pending_status (struct lwp_info
*lp
, int *status
)
1302 enum gdb_signal signo
= GDB_SIGNAL_0
;
1304 /* If we paused threads momentarily, we may have stored pending
1305 events in lp->status or lp->waitstatus (see stop_wait_callback),
1306 and GDB core hasn't seen any signal for those threads.
1307 Otherwise, the last signal reported to the core is found in the
1308 thread object's stop_signal.
1310 There's a corner case that isn't handled here at present. Only
1311 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1312 stop_signal make sense as a real signal to pass to the inferior.
1313 Some catchpoint related events, like
1314 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1315 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1316 those traps are debug API (ptrace in our case) related and
1317 induced; the inferior wouldn't see them if it wasn't being
1318 traced. Hence, we should never pass them to the inferior, even
1319 when set to pass state. Since this corner case isn't handled by
1320 infrun.c when proceeding with a signal, for consistency, neither
1321 do we handle it here (or elsewhere in the file we check for
1322 signal pass state). Normally SIGTRAP isn't set to pass state, so
1323 this is really a corner case. */
1325 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
1326 signo
= GDB_SIGNAL_0
; /* a pending ptrace event, not a real signal. */
1327 else if (lp
->status
)
1328 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1329 else if (target_is_non_stop_p () && !is_executing (lp
->ptid
))
1331 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1333 if (tp
->suspend
.waitstatus_pending_p
)
1334 signo
= tp
->suspend
.waitstatus
.value
.sig
;
1336 signo
= tp
->suspend
.stop_signal
;
1338 else if (!target_is_non_stop_p ())
1340 struct target_waitstatus last
;
1343 get_last_target_status (&last_ptid
, &last
);
1345 if (ptid_get_lwp (lp
->ptid
) == ptid_get_lwp (last_ptid
))
1347 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1349 signo
= tp
->suspend
.stop_signal
;
1355 if (signo
== GDB_SIGNAL_0
)
1357 if (debug_linux_nat
)
1358 fprintf_unfiltered (gdb_stdlog
,
1359 "GPT: lwp %s has no pending signal\n",
1360 target_pid_to_str (lp
->ptid
));
1362 else if (!signal_pass_state (signo
))
1364 if (debug_linux_nat
)
1365 fprintf_unfiltered (gdb_stdlog
,
1366 "GPT: lwp %s had signal %s, "
1367 "but it is in no pass state\n",
1368 target_pid_to_str (lp
->ptid
),
1369 gdb_signal_to_string (signo
));
1373 *status
= W_STOPCODE (gdb_signal_to_host (signo
));
1375 if (debug_linux_nat
)
1376 fprintf_unfiltered (gdb_stdlog
,
1377 "GPT: lwp %s has pending signal %s\n",
1378 target_pid_to_str (lp
->ptid
),
1379 gdb_signal_to_string (signo
));
1386 detach_callback (struct lwp_info
*lp
, void *data
)
1388 gdb_assert (lp
->status
== 0 || WIFSTOPPED (lp
->status
));
1390 if (debug_linux_nat
&& lp
->status
)
1391 fprintf_unfiltered (gdb_stdlog
, "DC: Pending %s for %s on detach.\n",
1392 strsignal (WSTOPSIG (lp
->status
)),
1393 target_pid_to_str (lp
->ptid
));
1395 /* If there is a pending SIGSTOP, get rid of it. */
1398 if (debug_linux_nat
)
1399 fprintf_unfiltered (gdb_stdlog
,
1400 "DC: Sending SIGCONT to %s\n",
1401 target_pid_to_str (lp
->ptid
));
1403 kill_lwp (ptid_get_lwp (lp
->ptid
), SIGCONT
);
1407 /* We don't actually detach from the LWP that has an id equal to the
1408 overall process id just yet. */
1409 if (ptid_get_lwp (lp
->ptid
) != ptid_get_pid (lp
->ptid
))
1413 /* Pass on any pending signal for this LWP. */
1414 get_pending_status (lp
, &status
);
1416 if (linux_nat_prepare_to_resume
!= NULL
)
1417 linux_nat_prepare_to_resume (lp
);
1419 if (ptrace (PTRACE_DETACH
, ptid_get_lwp (lp
->ptid
), 0,
1420 WSTOPSIG (status
)) < 0)
1421 error (_("Can't detach %s: %s"), target_pid_to_str (lp
->ptid
),
1422 safe_strerror (errno
));
1424 if (debug_linux_nat
)
1425 fprintf_unfiltered (gdb_stdlog
,
1426 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1427 target_pid_to_str (lp
->ptid
),
1428 strsignal (WSTOPSIG (status
)));
1430 delete_lwp (lp
->ptid
);
1437 linux_nat_detach (struct target_ops
*ops
, const char *args
, int from_tty
)
1441 struct lwp_info
*main_lwp
;
1443 pid
= ptid_get_pid (inferior_ptid
);
1445 /* Don't unregister from the event loop, as there may be other
1446 inferiors running. */
1448 /* Stop all threads before detaching. ptrace requires that the
1449 thread is stopped to sucessfully detach. */
1450 iterate_over_lwps (pid_to_ptid (pid
), stop_callback
, NULL
);
1451 /* ... and wait until all of them have reported back that
1452 they're no longer running. */
1453 iterate_over_lwps (pid_to_ptid (pid
), stop_wait_callback
, NULL
);
1455 iterate_over_lwps (pid_to_ptid (pid
), detach_callback
, NULL
);
1457 /* Only the initial process should be left right now. */
1458 gdb_assert (num_lwps (ptid_get_pid (inferior_ptid
)) == 1);
1460 main_lwp
= find_lwp_pid (pid_to_ptid (pid
));
1462 /* Pass on any pending signal for the last LWP. */
1463 if ((args
== NULL
|| *args
== '\0')
1464 && get_pending_status (main_lwp
, &status
) != -1
1465 && WIFSTOPPED (status
))
1469 /* Put the signal number in ARGS so that inf_ptrace_detach will
1470 pass it along with PTRACE_DETACH. */
1471 tem
= (char *) alloca (8);
1472 xsnprintf (tem
, 8, "%d", (int) WSTOPSIG (status
));
1474 if (debug_linux_nat
)
1475 fprintf_unfiltered (gdb_stdlog
,
1476 "LND: Sending signal %s to %s\n",
1478 target_pid_to_str (main_lwp
->ptid
));
1481 if (linux_nat_prepare_to_resume
!= NULL
)
1482 linux_nat_prepare_to_resume (main_lwp
);
1483 delete_lwp (main_lwp
->ptid
);
1485 if (forks_exist_p ())
1487 /* Multi-fork case. The current inferior_ptid is being detached
1488 from, but there are other viable forks to debug. Detach from
1489 the current fork, and context-switch to the first
1491 linux_fork_detach (args
, from_tty
);
1494 linux_ops
->to_detach (ops
, args
, from_tty
);
1497 /* Resume execution of the inferior process. If STEP is nonzero,
1498 single-step it. If SIGNAL is nonzero, give it that signal. */
1501 linux_resume_one_lwp_throw (struct lwp_info
*lp
, int step
,
1502 enum gdb_signal signo
)
1506 /* stop_pc doubles as the PC the LWP had when it was last resumed.
1507 We only presently need that if the LWP is stepped though (to
1508 handle the case of stepping a breakpoint instruction). */
1511 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
1513 lp
->stop_pc
= regcache_read_pc (regcache
);
1518 if (linux_nat_prepare_to_resume
!= NULL
)
1519 linux_nat_prepare_to_resume (lp
);
1520 linux_ops
->to_resume (linux_ops
, lp
->ptid
, step
, signo
);
1522 /* Successfully resumed. Clear state that no longer makes sense,
1523 and mark the LWP as running. Must not do this before resuming
1524 otherwise if that fails other code will be confused. E.g., we'd
1525 later try to stop the LWP and hang forever waiting for a stop
1526 status. Note that we must not throw after this is cleared,
1527 otherwise handle_zombie_lwp_error would get confused. */
1530 lp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
1531 registers_changed_ptid (lp
->ptid
);
1534 /* Called when we try to resume a stopped LWP and that errors out. If
1535 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
1536 or about to become), discard the error, clear any pending status
1537 the LWP may have, and return true (we'll collect the exit status
1538 soon enough). Otherwise, return false. */
1541 check_ptrace_stopped_lwp_gone (struct lwp_info
*lp
)
1543 /* If we get an error after resuming the LWP successfully, we'd
1544 confuse !T state for the LWP being gone. */
1545 gdb_assert (lp
->stopped
);
1547 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
1548 because even if ptrace failed with ESRCH, the tracee may be "not
1549 yet fully dead", but already refusing ptrace requests. In that
1550 case the tracee has 'R (Running)' state for a little bit
1551 (observed in Linux 3.18). See also the note on ESRCH in the
1552 ptrace(2) man page. Instead, check whether the LWP has any state
1553 other than ptrace-stopped. */
1555 /* Don't assume anything if /proc/PID/status can't be read. */
1556 if (linux_proc_pid_is_trace_stopped_nowarn (ptid_get_lwp (lp
->ptid
)) == 0)
1558 lp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
1560 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
1566 /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
1567 disappears while we try to resume it. */
1570 linux_resume_one_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1574 linux_resume_one_lwp_throw (lp
, step
, signo
);
1576 CATCH (ex
, RETURN_MASK_ERROR
)
1578 if (!check_ptrace_stopped_lwp_gone (lp
))
1579 throw_exception (ex
);
1587 resume_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1591 struct inferior
*inf
= find_inferior_ptid (lp
->ptid
);
1593 if (inf
->vfork_child
!= NULL
)
1595 if (debug_linux_nat
)
1596 fprintf_unfiltered (gdb_stdlog
,
1597 "RC: Not resuming %s (vfork parent)\n",
1598 target_pid_to_str (lp
->ptid
));
1600 else if (!lwp_status_pending_p (lp
))
1602 if (debug_linux_nat
)
1603 fprintf_unfiltered (gdb_stdlog
,
1604 "RC: Resuming sibling %s, %s, %s\n",
1605 target_pid_to_str (lp
->ptid
),
1606 (signo
!= GDB_SIGNAL_0
1607 ? strsignal (gdb_signal_to_host (signo
))
1609 step
? "step" : "resume");
1611 linux_resume_one_lwp (lp
, step
, signo
);
1615 if (debug_linux_nat
)
1616 fprintf_unfiltered (gdb_stdlog
,
1617 "RC: Not resuming sibling %s (has pending)\n",
1618 target_pid_to_str (lp
->ptid
));
1623 if (debug_linux_nat
)
1624 fprintf_unfiltered (gdb_stdlog
,
1625 "RC: Not resuming sibling %s (not stopped)\n",
1626 target_pid_to_str (lp
->ptid
));
1630 /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing.
1631 Resume LWP with the last stop signal, if it is in pass state. */
1634 linux_nat_resume_callback (struct lwp_info
*lp
, void *except
)
1636 enum gdb_signal signo
= GDB_SIGNAL_0
;
1643 struct thread_info
*thread
;
1645 thread
= find_thread_ptid (lp
->ptid
);
1648 signo
= thread
->suspend
.stop_signal
;
1649 thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
1653 resume_lwp (lp
, 0, signo
);
1658 resume_clear_callback (struct lwp_info
*lp
, void *data
)
1661 lp
->last_resume_kind
= resume_stop
;
1666 resume_set_callback (struct lwp_info
*lp
, void *data
)
1669 lp
->last_resume_kind
= resume_continue
;
1674 linux_nat_resume (struct target_ops
*ops
,
1675 ptid_t ptid
, int step
, enum gdb_signal signo
)
1677 struct lwp_info
*lp
;
1680 if (debug_linux_nat
)
1681 fprintf_unfiltered (gdb_stdlog
,
1682 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1683 step
? "step" : "resume",
1684 target_pid_to_str (ptid
),
1685 (signo
!= GDB_SIGNAL_0
1686 ? strsignal (gdb_signal_to_host (signo
)) : "0"),
1687 target_pid_to_str (inferior_ptid
));
1689 /* A specific PTID means `step only this process id'. */
1690 resume_many
= (ptid_equal (minus_one_ptid
, ptid
)
1691 || ptid_is_pid (ptid
));
1693 /* Mark the lwps we're resuming as resumed. */
1694 iterate_over_lwps (ptid
, resume_set_callback
, NULL
);
1696 /* See if it's the current inferior that should be handled
1699 lp
= find_lwp_pid (inferior_ptid
);
1701 lp
= find_lwp_pid (ptid
);
1702 gdb_assert (lp
!= NULL
);
1704 /* Remember if we're stepping. */
1705 lp
->last_resume_kind
= step
? resume_step
: resume_continue
;
1707 /* If we have a pending wait status for this thread, there is no
1708 point in resuming the process. But first make sure that
1709 linux_nat_wait won't preemptively handle the event - we
1710 should never take this short-circuit if we are going to
1711 leave LP running, since we have skipped resuming all the
1712 other threads. This bit of code needs to be synchronized
1713 with linux_nat_wait. */
1715 if (lp
->status
&& WIFSTOPPED (lp
->status
))
1718 && WSTOPSIG (lp
->status
)
1719 && sigismember (&pass_mask
, WSTOPSIG (lp
->status
)))
1721 if (debug_linux_nat
)
1722 fprintf_unfiltered (gdb_stdlog
,
1723 "LLR: Not short circuiting for ignored "
1724 "status 0x%x\n", lp
->status
);
1726 /* FIXME: What should we do if we are supposed to continue
1727 this thread with a signal? */
1728 gdb_assert (signo
== GDB_SIGNAL_0
);
1729 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1734 if (lwp_status_pending_p (lp
))
1736 /* FIXME: What should we do if we are supposed to continue
1737 this thread with a signal? */
1738 gdb_assert (signo
== GDB_SIGNAL_0
);
1740 if (debug_linux_nat
)
1741 fprintf_unfiltered (gdb_stdlog
,
1742 "LLR: Short circuiting for status 0x%x\n",
1745 if (target_can_async_p ())
1748 /* Tell the event loop we have something to process. */
1755 iterate_over_lwps (ptid
, linux_nat_resume_callback
, lp
);
1757 if (debug_linux_nat
)
1758 fprintf_unfiltered (gdb_stdlog
,
1759 "LLR: %s %s, %s (resume event thread)\n",
1760 step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1761 target_pid_to_str (lp
->ptid
),
1762 (signo
!= GDB_SIGNAL_0
1763 ? strsignal (gdb_signal_to_host (signo
)) : "0"));
1765 linux_resume_one_lwp (lp
, step
, signo
);
1767 if (target_can_async_p ())
1771 /* Send a signal to an LWP. */
1774 kill_lwp (int lwpid
, int signo
)
1779 ret
= syscall (__NR_tkill
, lwpid
, signo
);
1780 if (errno
== ENOSYS
)
1782 /* If tkill fails, then we are not using nptl threads, a
1783 configuration we no longer support. */
1784 perror_with_name (("tkill"));
1789 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1790 event, check if the core is interested in it: if not, ignore the
1791 event, and keep waiting; otherwise, we need to toggle the LWP's
1792 syscall entry/exit status, since the ptrace event itself doesn't
1793 indicate it, and report the trap to higher layers. */
1796 linux_handle_syscall_trap (struct lwp_info
*lp
, int stopping
)
1798 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1799 struct gdbarch
*gdbarch
= target_thread_architecture (lp
->ptid
);
1800 int syscall_number
= (int) gdbarch_get_syscall_number (gdbarch
, lp
->ptid
);
1804 /* If we're stopping threads, there's a SIGSTOP pending, which
1805 makes it so that the LWP reports an immediate syscall return,
1806 followed by the SIGSTOP. Skip seeing that "return" using
1807 PTRACE_CONT directly, and let stop_wait_callback collect the
1808 SIGSTOP. Later when the thread is resumed, a new syscall
1809 entry event. If we didn't do this (and returned 0), we'd
1810 leave a syscall entry pending, and our caller, by using
1811 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1812 itself. Later, when the user re-resumes this LWP, we'd see
1813 another syscall entry event and we'd mistake it for a return.
1815 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1816 (leaving immediately with LWP->signalled set, without issuing
1817 a PTRACE_CONT), it would still be problematic to leave this
1818 syscall enter pending, as later when the thread is resumed,
1819 it would then see the same syscall exit mentioned above,
1820 followed by the delayed SIGSTOP, while the syscall didn't
1821 actually get to execute. It seems it would be even more
1822 confusing to the user. */
1824 if (debug_linux_nat
)
1825 fprintf_unfiltered (gdb_stdlog
,
1826 "LHST: ignoring syscall %d "
1827 "for LWP %ld (stopping threads), "
1828 "resuming with PTRACE_CONT for SIGSTOP\n",
1830 ptid_get_lwp (lp
->ptid
));
1832 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1833 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
1838 /* Always update the entry/return state, even if this particular
1839 syscall isn't interesting to the core now. In async mode,
1840 the user could install a new catchpoint for this syscall
1841 between syscall enter/return, and we'll need to know to
1842 report a syscall return if that happens. */
1843 lp
->syscall_state
= (lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1844 ? TARGET_WAITKIND_SYSCALL_RETURN
1845 : TARGET_WAITKIND_SYSCALL_ENTRY
);
1847 if (catch_syscall_enabled ())
1849 if (catching_syscall_number (syscall_number
))
1851 /* Alright, an event to report. */
1852 ourstatus
->kind
= lp
->syscall_state
;
1853 ourstatus
->value
.syscall_number
= syscall_number
;
1855 if (debug_linux_nat
)
1856 fprintf_unfiltered (gdb_stdlog
,
1857 "LHST: stopping for %s of syscall %d"
1860 == TARGET_WAITKIND_SYSCALL_ENTRY
1861 ? "entry" : "return",
1863 ptid_get_lwp (lp
->ptid
));
1867 if (debug_linux_nat
)
1868 fprintf_unfiltered (gdb_stdlog
,
1869 "LHST: ignoring %s of syscall %d "
1871 lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1872 ? "entry" : "return",
1874 ptid_get_lwp (lp
->ptid
));
1878 /* If we had been syscall tracing, and hence used PT_SYSCALL
1879 before on this LWP, it could happen that the user removes all
1880 syscall catchpoints before we get to process this event.
1881 There are two noteworthy issues here:
1883 - When stopped at a syscall entry event, resuming with
1884 PT_STEP still resumes executing the syscall and reports a
1887 - Only PT_SYSCALL catches syscall enters. If we last
1888 single-stepped this thread, then this event can't be a
1889 syscall enter. If we last single-stepped this thread, this
1890 has to be a syscall exit.
1892 The points above mean that the next resume, be it PT_STEP or
1893 PT_CONTINUE, can not trigger a syscall trace event. */
1894 if (debug_linux_nat
)
1895 fprintf_unfiltered (gdb_stdlog
,
1896 "LHST: caught syscall event "
1897 "with no syscall catchpoints."
1898 " %d for LWP %ld, ignoring\n",
1900 ptid_get_lwp (lp
->ptid
));
1901 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1904 /* The core isn't interested in this event. For efficiency, avoid
1905 stopping all threads only to have the core resume them all again.
1906 Since we're not stopping threads, if we're still syscall tracing
1907 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1908 subsequent syscall. Simply resume using the inf-ptrace layer,
1909 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1911 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
1915 /* Handle a GNU/Linux extended wait response. If we see a clone
1916 event, we need to add the new LWP to our list (and not report the
1917 trap to higher layers). This function returns non-zero if the
1918 event should be ignored and we should wait again. If STOPPING is
1919 true, the new LWP remains stopped, otherwise it is continued. */
1922 linux_handle_extended_wait (struct lwp_info
*lp
, int status
)
1924 int pid
= ptid_get_lwp (lp
->ptid
);
1925 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1926 int event
= linux_ptrace_get_extended_event (status
);
1928 /* All extended events we currently use are mid-syscall. Only
1929 PTRACE_EVENT_STOP is delivered more like a signal-stop, but
1930 you have to be using PTRACE_SEIZE to get that. */
1931 lp
->syscall_state
= TARGET_WAITKIND_SYSCALL_ENTRY
;
1933 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
1934 || event
== PTRACE_EVENT_CLONE
)
1936 unsigned long new_pid
;
1939 ptrace (PTRACE_GETEVENTMSG
, pid
, 0, &new_pid
);
1941 /* If we haven't already seen the new PID stop, wait for it now. */
1942 if (! pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
1944 /* The new child has a pending SIGSTOP. We can't affect it until it
1945 hits the SIGSTOP, but we're already attached. */
1946 ret
= my_waitpid (new_pid
, &status
, __WALL
);
1948 perror_with_name (_("waiting for new child"));
1949 else if (ret
!= new_pid
)
1950 internal_error (__FILE__
, __LINE__
,
1951 _("wait returned unexpected PID %d"), ret
);
1952 else if (!WIFSTOPPED (status
))
1953 internal_error (__FILE__
, __LINE__
,
1954 _("wait returned unexpected status 0x%x"), status
);
1957 ourstatus
->value
.related_pid
= ptid_build (new_pid
, new_pid
, 0);
1959 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
)
1961 /* The arch-specific native code may need to know about new
1962 forks even if those end up never mapped to an
1964 if (linux_nat_new_fork
!= NULL
)
1965 linux_nat_new_fork (lp
, new_pid
);
1968 if (event
== PTRACE_EVENT_FORK
1969 && linux_fork_checkpointing_p (ptid_get_pid (lp
->ptid
)))
1971 /* Handle checkpointing by linux-fork.c here as a special
1972 case. We don't want the follow-fork-mode or 'catch fork'
1973 to interfere with this. */
1975 /* This won't actually modify the breakpoint list, but will
1976 physically remove the breakpoints from the child. */
1977 detach_breakpoints (ptid_build (new_pid
, new_pid
, 0));
1979 /* Retain child fork in ptrace (stopped) state. */
1980 if (!find_fork_pid (new_pid
))
1983 /* Report as spurious, so that infrun doesn't want to follow
1984 this fork. We're actually doing an infcall in
1986 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
1988 /* Report the stop to the core. */
1992 if (event
== PTRACE_EVENT_FORK
)
1993 ourstatus
->kind
= TARGET_WAITKIND_FORKED
;
1994 else if (event
== PTRACE_EVENT_VFORK
)
1995 ourstatus
->kind
= TARGET_WAITKIND_VFORKED
;
1996 else if (event
== PTRACE_EVENT_CLONE
)
1998 struct lwp_info
*new_lp
;
2000 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2002 if (debug_linux_nat
)
2003 fprintf_unfiltered (gdb_stdlog
,
2004 "LHEW: Got clone event "
2005 "from LWP %d, new child is LWP %ld\n",
2008 new_lp
= add_lwp (ptid_build (ptid_get_pid (lp
->ptid
), new_pid
, 0));
2009 new_lp
->stopped
= 1;
2010 new_lp
->resumed
= 1;
2012 /* If the thread_db layer is active, let it record the user
2013 level thread id and status, and add the thread to GDB's
2015 if (!thread_db_notice_clone (lp
->ptid
, new_lp
->ptid
))
2017 /* The process is not using thread_db. Add the LWP to
2019 target_post_attach (ptid_get_lwp (new_lp
->ptid
));
2020 add_thread (new_lp
->ptid
);
2023 /* Even if we're stopping the thread for some reason
2024 internal to this module, from the perspective of infrun
2025 and the user/frontend, this new thread is running until
2026 it next reports a stop. */
2027 set_running (new_lp
->ptid
, 1);
2028 set_executing (new_lp
->ptid
, 1);
2030 if (WSTOPSIG (status
) != SIGSTOP
)
2032 /* This can happen if someone starts sending signals to
2033 the new thread before it gets a chance to run, which
2034 have a lower number than SIGSTOP (e.g. SIGUSR1).
2035 This is an unlikely case, and harder to handle for
2036 fork / vfork than for clone, so we do not try - but
2037 we handle it for clone events here. */
2039 new_lp
->signalled
= 1;
2041 /* We created NEW_LP so it cannot yet contain STATUS. */
2042 gdb_assert (new_lp
->status
== 0);
2044 /* Save the wait status to report later. */
2045 if (debug_linux_nat
)
2046 fprintf_unfiltered (gdb_stdlog
,
2047 "LHEW: waitpid of new LWP %ld, "
2048 "saving status %s\n",
2049 (long) ptid_get_lwp (new_lp
->ptid
),
2050 status_to_str (status
));
2051 new_lp
->status
= status
;
2053 else if (report_thread_events
)
2055 new_lp
->waitstatus
.kind
= TARGET_WAITKIND_THREAD_CREATED
;
2056 new_lp
->status
= status
;
2065 if (event
== PTRACE_EVENT_EXEC
)
2067 if (debug_linux_nat
)
2068 fprintf_unfiltered (gdb_stdlog
,
2069 "LHEW: Got exec event from LWP %ld\n",
2070 ptid_get_lwp (lp
->ptid
));
2072 ourstatus
->kind
= TARGET_WAITKIND_EXECD
;
2073 ourstatus
->value
.execd_pathname
2074 = xstrdup (linux_child_pid_to_exec_file (NULL
, pid
));
2076 /* The thread that execed must have been resumed, but, when a
2077 thread execs, it changes its tid to the tgid, and the old
2078 tgid thread might have not been resumed. */
2083 if (event
== PTRACE_EVENT_VFORK_DONE
)
2085 if (current_inferior ()->waiting_for_vfork_done
)
2087 if (debug_linux_nat
)
2088 fprintf_unfiltered (gdb_stdlog
,
2089 "LHEW: Got expected PTRACE_EVENT_"
2090 "VFORK_DONE from LWP %ld: stopping\n",
2091 ptid_get_lwp (lp
->ptid
));
2093 ourstatus
->kind
= TARGET_WAITKIND_VFORK_DONE
;
2097 if (debug_linux_nat
)
2098 fprintf_unfiltered (gdb_stdlog
,
2099 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2100 "from LWP %ld: ignoring\n",
2101 ptid_get_lwp (lp
->ptid
));
2105 internal_error (__FILE__
, __LINE__
,
2106 _("unknown ptrace event %d"), event
);
2109 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2113 wait_lwp (struct lwp_info
*lp
)
2117 int thread_dead
= 0;
2120 gdb_assert (!lp
->stopped
);
2121 gdb_assert (lp
->status
== 0);
2123 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2124 block_child_signals (&prev_mask
);
2128 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), &status
, __WALL
| WNOHANG
);
2129 if (pid
== -1 && errno
== ECHILD
)
2131 /* The thread has previously exited. We need to delete it
2132 now because if this was a non-leader thread execing, we
2133 won't get an exit event. See comments on exec events at
2134 the top of the file. */
2136 if (debug_linux_nat
)
2137 fprintf_unfiltered (gdb_stdlog
, "WL: %s vanished.\n",
2138 target_pid_to_str (lp
->ptid
));
2143 /* Bugs 10970, 12702.
2144 Thread group leader may have exited in which case we'll lock up in
2145 waitpid if there are other threads, even if they are all zombies too.
2146 Basically, we're not supposed to use waitpid this way.
2147 tkill(pid,0) cannot be used here as it gets ESRCH for both
2148 for zombie and running processes.
2150 As a workaround, check if we're waiting for the thread group leader and
2151 if it's a zombie, and avoid calling waitpid if it is.
2153 This is racy, what if the tgl becomes a zombie right after we check?
2154 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2155 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2157 if (ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
)
2158 && linux_proc_pid_is_zombie (ptid_get_lwp (lp
->ptid
)))
2161 if (debug_linux_nat
)
2162 fprintf_unfiltered (gdb_stdlog
,
2163 "WL: Thread group leader %s vanished.\n",
2164 target_pid_to_str (lp
->ptid
));
2168 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2169 get invoked despite our caller had them intentionally blocked by
2170 block_child_signals. This is sensitive only to the loop of
2171 linux_nat_wait_1 and there if we get called my_waitpid gets called
2172 again before it gets to sigsuspend so we can safely let the handlers
2173 get executed here. */
2175 if (debug_linux_nat
)
2176 fprintf_unfiltered (gdb_stdlog
, "WL: about to sigsuspend\n");
2177 sigsuspend (&suspend_mask
);
2180 restore_child_signals_mask (&prev_mask
);
2184 gdb_assert (pid
== ptid_get_lwp (lp
->ptid
));
2186 if (debug_linux_nat
)
2188 fprintf_unfiltered (gdb_stdlog
,
2189 "WL: waitpid %s received %s\n",
2190 target_pid_to_str (lp
->ptid
),
2191 status_to_str (status
));
2194 /* Check if the thread has exited. */
2195 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2197 if (report_thread_events
2198 || ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
))
2200 if (debug_linux_nat
)
2201 fprintf_unfiltered (gdb_stdlog
, "WL: LWP %d exited.\n",
2202 ptid_get_pid (lp
->ptid
));
2204 /* If this is the leader exiting, it means the whole
2205 process is gone. Store the status to report to the
2206 core. Store it in lp->waitstatus, because lp->status
2207 would be ambiguous (W_EXITCODE(0,0) == 0). */
2208 store_waitstatus (&lp
->waitstatus
, status
);
2213 if (debug_linux_nat
)
2214 fprintf_unfiltered (gdb_stdlog
, "WL: %s exited.\n",
2215 target_pid_to_str (lp
->ptid
));
2225 gdb_assert (WIFSTOPPED (status
));
2228 if (lp
->must_set_ptrace_flags
)
2230 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
2231 int options
= linux_nat_ptrace_options (inf
->attach_flag
);
2233 linux_enable_event_reporting (ptid_get_lwp (lp
->ptid
), options
);
2234 lp
->must_set_ptrace_flags
= 0;
2237 /* Handle GNU/Linux's syscall SIGTRAPs. */
2238 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2240 /* No longer need the sysgood bit. The ptrace event ends up
2241 recorded in lp->waitstatus if we care for it. We can carry
2242 on handling the event like a regular SIGTRAP from here
2244 status
= W_STOPCODE (SIGTRAP
);
2245 if (linux_handle_syscall_trap (lp
, 1))
2246 return wait_lwp (lp
);
2250 /* Almost all other ptrace-stops are known to be outside of system
2251 calls, with further exceptions in linux_handle_extended_wait. */
2252 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2255 /* Handle GNU/Linux's extended waitstatus for trace events. */
2256 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
2257 && linux_is_extended_waitstatus (status
))
2259 if (debug_linux_nat
)
2260 fprintf_unfiltered (gdb_stdlog
,
2261 "WL: Handling extended status 0x%06x\n",
2263 linux_handle_extended_wait (lp
, status
);
2270 /* Send a SIGSTOP to LP. */
2273 stop_callback (struct lwp_info
*lp
, void *data
)
2275 if (!lp
->stopped
&& !lp
->signalled
)
2279 if (debug_linux_nat
)
2281 fprintf_unfiltered (gdb_stdlog
,
2282 "SC: kill %s **<SIGSTOP>**\n",
2283 target_pid_to_str (lp
->ptid
));
2286 ret
= kill_lwp (ptid_get_lwp (lp
->ptid
), SIGSTOP
);
2287 if (debug_linux_nat
)
2289 fprintf_unfiltered (gdb_stdlog
,
2290 "SC: lwp kill %d %s\n",
2292 errno
? safe_strerror (errno
) : "ERRNO-OK");
2296 gdb_assert (lp
->status
== 0);
2302 /* Request a stop on LWP. */
2305 linux_stop_lwp (struct lwp_info
*lwp
)
2307 stop_callback (lwp
, NULL
);
2310 /* See linux-nat.h */
2313 linux_stop_and_wait_all_lwps (void)
2315 /* Stop all LWP's ... */
2316 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
2318 /* ... and wait until all of them have reported back that
2319 they're no longer running. */
2320 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
2323 /* See linux-nat.h */
2326 linux_unstop_all_lwps (void)
2328 iterate_over_lwps (minus_one_ptid
,
2329 resume_stopped_resumed_lwps
, &minus_one_ptid
);
2332 /* Return non-zero if LWP PID has a pending SIGINT. */
2335 linux_nat_has_pending_sigint (int pid
)
2337 sigset_t pending
, blocked
, ignored
;
2339 linux_proc_pending_signals (pid
, &pending
, &blocked
, &ignored
);
2341 if (sigismember (&pending
, SIGINT
)
2342 && !sigismember (&ignored
, SIGINT
))
2348 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2351 set_ignore_sigint (struct lwp_info
*lp
, void *data
)
2353 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2354 flag to consume the next one. */
2355 if (lp
->stopped
&& lp
->status
!= 0 && WIFSTOPPED (lp
->status
)
2356 && WSTOPSIG (lp
->status
) == SIGINT
)
2359 lp
->ignore_sigint
= 1;
2364 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2365 This function is called after we know the LWP has stopped; if the LWP
2366 stopped before the expected SIGINT was delivered, then it will never have
2367 arrived. Also, if the signal was delivered to a shared queue and consumed
2368 by a different thread, it will never be delivered to this LWP. */
2371 maybe_clear_ignore_sigint (struct lwp_info
*lp
)
2373 if (!lp
->ignore_sigint
)
2376 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp
->ptid
)))
2378 if (debug_linux_nat
)
2379 fprintf_unfiltered (gdb_stdlog
,
2380 "MCIS: Clearing bogus flag for %s\n",
2381 target_pid_to_str (lp
->ptid
));
2382 lp
->ignore_sigint
= 0;
2386 /* Fetch the possible triggered data watchpoint info and store it in
2389 On some archs, like x86, that use debug registers to set
2390 watchpoints, it's possible that the way to know which watched
2391 address trapped, is to check the register that is used to select
2392 which address to watch. Problem is, between setting the watchpoint
2393 and reading back which data address trapped, the user may change
2394 the set of watchpoints, and, as a consequence, GDB changes the
2395 debug registers in the inferior. To avoid reading back a stale
2396 stopped-data-address when that happens, we cache in LP the fact
2397 that a watchpoint trapped, and the corresponding data address, as
2398 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2399 registers meanwhile, we have the cached data we can rely on. */
2402 check_stopped_by_watchpoint (struct lwp_info
*lp
)
2404 struct cleanup
*old_chain
;
2406 if (linux_ops
->to_stopped_by_watchpoint
== NULL
)
2409 old_chain
= save_inferior_ptid ();
2410 inferior_ptid
= lp
->ptid
;
2412 if (linux_ops
->to_stopped_by_watchpoint (linux_ops
))
2414 lp
->stop_reason
= TARGET_STOPPED_BY_WATCHPOINT
;
2416 if (linux_ops
->to_stopped_data_address
!= NULL
)
2417 lp
->stopped_data_address_p
=
2418 linux_ops
->to_stopped_data_address (¤t_target
,
2419 &lp
->stopped_data_address
);
2421 lp
->stopped_data_address_p
= 0;
2424 do_cleanups (old_chain
);
2426 return lp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
2429 /* Returns true if the LWP had stopped for a watchpoint. */
2432 linux_nat_stopped_by_watchpoint (struct target_ops
*ops
)
2434 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2436 gdb_assert (lp
!= NULL
);
2438 return lp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
2442 linux_nat_stopped_data_address (struct target_ops
*ops
, CORE_ADDR
*addr_p
)
2444 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2446 gdb_assert (lp
!= NULL
);
2448 *addr_p
= lp
->stopped_data_address
;
2450 return lp
->stopped_data_address_p
;
2453 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2456 sigtrap_is_event (int status
)
2458 return WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
;
2461 /* Set alternative SIGTRAP-like events recognizer. If
2462 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2466 linux_nat_set_status_is_event (struct target_ops
*t
,
2467 int (*status_is_event
) (int status
))
2469 linux_nat_status_is_event
= status_is_event
;
2472 /* Wait until LP is stopped. */
2475 stop_wait_callback (struct lwp_info
*lp
, void *data
)
2477 struct inferior
*inf
= find_inferior_ptid (lp
->ptid
);
2479 /* If this is a vfork parent, bail out, it is not going to report
2480 any SIGSTOP until the vfork is done with. */
2481 if (inf
->vfork_child
!= NULL
)
2488 status
= wait_lwp (lp
);
2492 if (lp
->ignore_sigint
&& WIFSTOPPED (status
)
2493 && WSTOPSIG (status
) == SIGINT
)
2495 lp
->ignore_sigint
= 0;
2498 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
2500 if (debug_linux_nat
)
2501 fprintf_unfiltered (gdb_stdlog
,
2502 "PTRACE_CONT %s, 0, 0 (%s) "
2503 "(discarding SIGINT)\n",
2504 target_pid_to_str (lp
->ptid
),
2505 errno
? safe_strerror (errno
) : "OK");
2507 return stop_wait_callback (lp
, NULL
);
2510 maybe_clear_ignore_sigint (lp
);
2512 if (WSTOPSIG (status
) != SIGSTOP
)
2514 /* The thread was stopped with a signal other than SIGSTOP. */
2516 if (debug_linux_nat
)
2517 fprintf_unfiltered (gdb_stdlog
,
2518 "SWC: Pending event %s in %s\n",
2519 status_to_str ((int) status
),
2520 target_pid_to_str (lp
->ptid
));
2522 /* Save the sigtrap event. */
2523 lp
->status
= status
;
2524 gdb_assert (lp
->signalled
);
2525 save_stop_reason (lp
);
2529 /* We caught the SIGSTOP that we intended to catch, so
2530 there's no SIGSTOP pending. */
2532 if (debug_linux_nat
)
2533 fprintf_unfiltered (gdb_stdlog
,
2534 "SWC: Expected SIGSTOP caught for %s.\n",
2535 target_pid_to_str (lp
->ptid
));
2537 /* Reset SIGNALLED only after the stop_wait_callback call
2538 above as it does gdb_assert on SIGNALLED. */
2546 /* Return non-zero if LP has a wait status pending. Discard the
2547 pending event and resume the LWP if the event that originally
2548 caused the stop became uninteresting. */
2551 status_callback (struct lwp_info
*lp
, void *data
)
2553 /* Only report a pending wait status if we pretend that this has
2554 indeed been resumed. */
2558 if (!lwp_status_pending_p (lp
))
2561 if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
2562 || lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
)
2564 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
2568 pc
= regcache_read_pc (regcache
);
2570 if (pc
!= lp
->stop_pc
)
2572 if (debug_linux_nat
)
2573 fprintf_unfiltered (gdb_stdlog
,
2574 "SC: PC of %s changed. was=%s, now=%s\n",
2575 target_pid_to_str (lp
->ptid
),
2576 paddress (target_gdbarch (), lp
->stop_pc
),
2577 paddress (target_gdbarch (), pc
));
2581 #if !USE_SIGTRAP_SIGINFO
2582 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
2584 if (debug_linux_nat
)
2585 fprintf_unfiltered (gdb_stdlog
,
2586 "SC: previous breakpoint of %s, at %s gone\n",
2587 target_pid_to_str (lp
->ptid
),
2588 paddress (target_gdbarch (), lp
->stop_pc
));
2596 if (debug_linux_nat
)
2597 fprintf_unfiltered (gdb_stdlog
,
2598 "SC: pending event of %s cancelled.\n",
2599 target_pid_to_str (lp
->ptid
));
2602 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
2610 /* Count the LWP's that have had events. */
2613 count_events_callback (struct lwp_info
*lp
, void *data
)
2615 int *count
= (int *) data
;
2617 gdb_assert (count
!= NULL
);
2619 /* Select only resumed LWPs that have an event pending. */
2620 if (lp
->resumed
&& lwp_status_pending_p (lp
))
2626 /* Select the LWP (if any) that is currently being single-stepped. */
2629 select_singlestep_lwp_callback (struct lwp_info
*lp
, void *data
)
2631 if (lp
->last_resume_kind
== resume_step
2638 /* Returns true if LP has a status pending. */
2641 lwp_status_pending_p (struct lwp_info
*lp
)
2643 /* We check for lp->waitstatus in addition to lp->status, because we
2644 can have pending process exits recorded in lp->status and
2645 W_EXITCODE(0,0) happens to be 0. */
2646 return lp
->status
!= 0 || lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
;
2649 /* Select the Nth LWP that has had an event. */
2652 select_event_lwp_callback (struct lwp_info
*lp
, void *data
)
2654 int *selector
= (int *) data
;
2656 gdb_assert (selector
!= NULL
);
2658 /* Select only resumed LWPs that have an event pending. */
2659 if (lp
->resumed
&& lwp_status_pending_p (lp
))
2660 if ((*selector
)-- == 0)
2666 /* Called when the LWP stopped for a signal/trap. If it stopped for a
2667 trap check what caused it (breakpoint, watchpoint, trace, etc.),
2668 and save the result in the LWP's stop_reason field. If it stopped
2669 for a breakpoint, decrement the PC if necessary on the lwp's
2673 save_stop_reason (struct lwp_info
*lp
)
2675 struct regcache
*regcache
;
2676 struct gdbarch
*gdbarch
;
2679 #if USE_SIGTRAP_SIGINFO
2683 gdb_assert (lp
->stop_reason
== TARGET_STOPPED_BY_NO_REASON
);
2684 gdb_assert (lp
->status
!= 0);
2686 if (!linux_nat_status_is_event (lp
->status
))
2689 regcache
= get_thread_regcache (lp
->ptid
);
2690 gdbarch
= get_regcache_arch (regcache
);
2692 pc
= regcache_read_pc (regcache
);
2693 sw_bp_pc
= pc
- gdbarch_decr_pc_after_break (gdbarch
);
2695 #if USE_SIGTRAP_SIGINFO
2696 if (linux_nat_get_siginfo (lp
->ptid
, &siginfo
))
2698 if (siginfo
.si_signo
== SIGTRAP
)
2700 if (GDB_ARCH_IS_TRAP_BRKPT (siginfo
.si_code
)
2701 && GDB_ARCH_IS_TRAP_HWBKPT (siginfo
.si_code
))
2703 /* The si_code is ambiguous on this arch -- check debug
2705 if (!check_stopped_by_watchpoint (lp
))
2706 lp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
2708 else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo
.si_code
))
2710 /* If we determine the LWP stopped for a SW breakpoint,
2711 trust it. Particularly don't check watchpoint
2712 registers, because at least on s390, we'd find
2713 stopped-by-watchpoint as long as there's a watchpoint
2715 lp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
2717 else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo
.si_code
))
2719 /* This can indicate either a hardware breakpoint or
2720 hardware watchpoint. Check debug registers. */
2721 if (!check_stopped_by_watchpoint (lp
))
2722 lp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
2724 else if (siginfo
.si_code
== TRAP_TRACE
)
2726 if (debug_linux_nat
)
2727 fprintf_unfiltered (gdb_stdlog
,
2728 "CSBB: %s stopped by trace\n",
2729 target_pid_to_str (lp
->ptid
));
2731 /* We may have single stepped an instruction that
2732 triggered a watchpoint. In that case, on some
2733 architectures (such as x86), instead of TRAP_HWBKPT,
2734 si_code indicates TRAP_TRACE, and we need to check
2735 the debug registers separately. */
2736 check_stopped_by_watchpoint (lp
);
2741 if ((!lp
->step
|| lp
->stop_pc
== sw_bp_pc
)
2742 && software_breakpoint_inserted_here_p (get_regcache_aspace (regcache
),
2745 /* The LWP was either continued, or stepped a software
2746 breakpoint instruction. */
2747 lp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
2750 if (hardware_breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
2751 lp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
2753 if (lp
->stop_reason
== TARGET_STOPPED_BY_NO_REASON
)
2754 check_stopped_by_watchpoint (lp
);
2757 if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
)
2759 if (debug_linux_nat
)
2760 fprintf_unfiltered (gdb_stdlog
,
2761 "CSBB: %s stopped by software breakpoint\n",
2762 target_pid_to_str (lp
->ptid
));
2764 /* Back up the PC if necessary. */
2766 regcache_write_pc (regcache
, sw_bp_pc
);
2768 /* Update this so we record the correct stop PC below. */
2771 else if (lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
)
2773 if (debug_linux_nat
)
2774 fprintf_unfiltered (gdb_stdlog
,
2775 "CSBB: %s stopped by hardware breakpoint\n",
2776 target_pid_to_str (lp
->ptid
));
2778 else if (lp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
)
2780 if (debug_linux_nat
)
2781 fprintf_unfiltered (gdb_stdlog
,
2782 "CSBB: %s stopped by hardware watchpoint\n",
2783 target_pid_to_str (lp
->ptid
));
2790 /* Returns true if the LWP had stopped for a software breakpoint. */
2793 linux_nat_stopped_by_sw_breakpoint (struct target_ops
*ops
)
2795 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2797 gdb_assert (lp
!= NULL
);
2799 return lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
;
2802 /* Implement the supports_stopped_by_sw_breakpoint method. */
2805 linux_nat_supports_stopped_by_sw_breakpoint (struct target_ops
*ops
)
2807 return USE_SIGTRAP_SIGINFO
;
2810 /* Returns true if the LWP had stopped for a hardware
2811 breakpoint/watchpoint. */
2814 linux_nat_stopped_by_hw_breakpoint (struct target_ops
*ops
)
2816 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2818 gdb_assert (lp
!= NULL
);
2820 return lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
;
2823 /* Implement the supports_stopped_by_hw_breakpoint method. */
2826 linux_nat_supports_stopped_by_hw_breakpoint (struct target_ops
*ops
)
2828 return USE_SIGTRAP_SIGINFO
;
2831 /* Select one LWP out of those that have events pending. */
2834 select_event_lwp (ptid_t filter
, struct lwp_info
**orig_lp
, int *status
)
2837 int random_selector
;
2838 struct lwp_info
*event_lp
= NULL
;
2840 /* Record the wait status for the original LWP. */
2841 (*orig_lp
)->status
= *status
;
2843 /* In all-stop, give preference to the LWP that is being
2844 single-stepped. There will be at most one, and it will be the
2845 LWP that the core is most interested in. If we didn't do this,
2846 then we'd have to handle pending step SIGTRAPs somehow in case
2847 the core later continues the previously-stepped thread, as
2848 otherwise we'd report the pending SIGTRAP then, and the core, not
2849 having stepped the thread, wouldn't understand what the trap was
2850 for, and therefore would report it to the user as a random
2852 if (!target_is_non_stop_p ())
2854 event_lp
= iterate_over_lwps (filter
,
2855 select_singlestep_lwp_callback
, NULL
);
2856 if (event_lp
!= NULL
)
2858 if (debug_linux_nat
)
2859 fprintf_unfiltered (gdb_stdlog
,
2860 "SEL: Select single-step %s\n",
2861 target_pid_to_str (event_lp
->ptid
));
2865 if (event_lp
== NULL
)
2867 /* Pick one at random, out of those which have had events. */
2869 /* First see how many events we have. */
2870 iterate_over_lwps (filter
, count_events_callback
, &num_events
);
2871 gdb_assert (num_events
> 0);
2873 /* Now randomly pick a LWP out of those that have had
2875 random_selector
= (int)
2876 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
2878 if (debug_linux_nat
&& num_events
> 1)
2879 fprintf_unfiltered (gdb_stdlog
,
2880 "SEL: Found %d events, selecting #%d\n",
2881 num_events
, random_selector
);
2883 event_lp
= iterate_over_lwps (filter
,
2884 select_event_lwp_callback
,
2888 if (event_lp
!= NULL
)
2890 /* Switch the event LWP. */
2891 *orig_lp
= event_lp
;
2892 *status
= event_lp
->status
;
2895 /* Flush the wait status for the event LWP. */
2896 (*orig_lp
)->status
= 0;
2899 /* Return non-zero if LP has been resumed. */
2902 resumed_callback (struct lwp_info
*lp
, void *data
)
2907 /* Check if we should go on and pass this event to common code.
2908 Return the affected lwp if we are, or NULL otherwise. */
2910 static struct lwp_info
*
2911 linux_nat_filter_event (int lwpid
, int status
)
2913 struct lwp_info
*lp
;
2914 int event
= linux_ptrace_get_extended_event (status
);
2916 lp
= find_lwp_pid (pid_to_ptid (lwpid
));
2918 /* Check for stop events reported by a process we didn't already
2919 know about - anything not already in our LWP list.
2921 If we're expecting to receive stopped processes after
2922 fork, vfork, and clone events, then we'll just add the
2923 new one to our list and go back to waiting for the event
2924 to be reported - the stopped process might be returned
2925 from waitpid before or after the event is.
2927 But note the case of a non-leader thread exec'ing after the
2928 leader having exited, and gone from our lists. The non-leader
2929 thread changes its tid to the tgid. */
2931 if (WIFSTOPPED (status
) && lp
== NULL
2932 && (WSTOPSIG (status
) == SIGTRAP
&& event
== PTRACE_EVENT_EXEC
))
2934 /* A multi-thread exec after we had seen the leader exiting. */
2935 if (debug_linux_nat
)
2936 fprintf_unfiltered (gdb_stdlog
,
2937 "LLW: Re-adding thread group leader LWP %d.\n",
2940 lp
= add_lwp (ptid_build (lwpid
, lwpid
, 0));
2943 add_thread (lp
->ptid
);
2946 if (WIFSTOPPED (status
) && !lp
)
2948 if (debug_linux_nat
)
2949 fprintf_unfiltered (gdb_stdlog
,
2950 "LHEW: saving LWP %ld status %s in stopped_pids list\n",
2951 (long) lwpid
, status_to_str (status
));
2952 add_to_pid_list (&stopped_pids
, lwpid
, status
);
2956 /* Make sure we don't report an event for the exit of an LWP not in
2957 our list, i.e. not part of the current process. This can happen
2958 if we detach from a program we originally forked and then it
2960 if (!WIFSTOPPED (status
) && !lp
)
2963 /* This LWP is stopped now. (And if dead, this prevents it from
2964 ever being continued.) */
2967 if (WIFSTOPPED (status
) && lp
->must_set_ptrace_flags
)
2969 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
2970 int options
= linux_nat_ptrace_options (inf
->attach_flag
);
2972 linux_enable_event_reporting (ptid_get_lwp (lp
->ptid
), options
);
2973 lp
->must_set_ptrace_flags
= 0;
2976 /* Handle GNU/Linux's syscall SIGTRAPs. */
2977 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2979 /* No longer need the sysgood bit. The ptrace event ends up
2980 recorded in lp->waitstatus if we care for it. We can carry
2981 on handling the event like a regular SIGTRAP from here
2983 status
= W_STOPCODE (SIGTRAP
);
2984 if (linux_handle_syscall_trap (lp
, 0))
2989 /* Almost all other ptrace-stops are known to be outside of system
2990 calls, with further exceptions in linux_handle_extended_wait. */
2991 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2994 /* Handle GNU/Linux's extended waitstatus for trace events. */
2995 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
2996 && linux_is_extended_waitstatus (status
))
2998 if (debug_linux_nat
)
2999 fprintf_unfiltered (gdb_stdlog
,
3000 "LLW: Handling extended status 0x%06x\n",
3002 if (linux_handle_extended_wait (lp
, status
))
3006 /* Check if the thread has exited. */
3007 if (WIFEXITED (status
) || WIFSIGNALED (status
))
3009 if (!report_thread_events
3010 && num_lwps (ptid_get_pid (lp
->ptid
)) > 1)
3012 if (debug_linux_nat
)
3013 fprintf_unfiltered (gdb_stdlog
,
3014 "LLW: %s exited.\n",
3015 target_pid_to_str (lp
->ptid
));
3017 /* If there is at least one more LWP, then the exit signal
3018 was not the end of the debugged application and should be
3024 /* Note that even if the leader was ptrace-stopped, it can still
3025 exit, if e.g., some other thread brings down the whole
3026 process (calls `exit'). So don't assert that the lwp is
3028 if (debug_linux_nat
)
3029 fprintf_unfiltered (gdb_stdlog
,
3030 "LWP %ld exited (resumed=%d)\n",
3031 ptid_get_lwp (lp
->ptid
), lp
->resumed
);
3033 /* Dead LWP's aren't expected to reported a pending sigstop. */
3036 /* Store the pending event in the waitstatus, because
3037 W_EXITCODE(0,0) == 0. */
3038 store_waitstatus (&lp
->waitstatus
, status
);
3042 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3043 an attempt to stop an LWP. */
3045 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGSTOP
)
3049 if (lp
->last_resume_kind
== resume_stop
)
3051 if (debug_linux_nat
)
3052 fprintf_unfiltered (gdb_stdlog
,
3053 "LLW: resume_stop SIGSTOP caught for %s.\n",
3054 target_pid_to_str (lp
->ptid
));
3058 /* This is a delayed SIGSTOP. Filter out the event. */
3060 if (debug_linux_nat
)
3061 fprintf_unfiltered (gdb_stdlog
,
3062 "LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
3064 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3065 target_pid_to_str (lp
->ptid
));
3067 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
3068 gdb_assert (lp
->resumed
);
3073 /* Make sure we don't report a SIGINT that we have already displayed
3074 for another thread. */
3075 if (lp
->ignore_sigint
3076 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGINT
)
3078 if (debug_linux_nat
)
3079 fprintf_unfiltered (gdb_stdlog
,
3080 "LLW: Delayed SIGINT caught for %s.\n",
3081 target_pid_to_str (lp
->ptid
));
3083 /* This is a delayed SIGINT. */
3084 lp
->ignore_sigint
= 0;
3086 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
3087 if (debug_linux_nat
)
3088 fprintf_unfiltered (gdb_stdlog
,
3089 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3091 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3092 target_pid_to_str (lp
->ptid
));
3093 gdb_assert (lp
->resumed
);
3095 /* Discard the event. */
3099 /* Don't report signals that GDB isn't interested in, such as
3100 signals that are neither printed nor stopped upon. Stopping all
3101 threads can be a bit time-consuming so if we want decent
3102 performance with heavily multi-threaded programs, especially when
3103 they're using a high frequency timer, we'd better avoid it if we
3105 if (WIFSTOPPED (status
))
3107 enum gdb_signal signo
= gdb_signal_from_host (WSTOPSIG (status
));
3109 if (!target_is_non_stop_p ())
3111 /* Only do the below in all-stop, as we currently use SIGSTOP
3112 to implement target_stop (see linux_nat_stop) in
3114 if (signo
== GDB_SIGNAL_INT
&& signal_pass_state (signo
) == 0)
3116 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3117 forwarded to the entire process group, that is, all LWPs
3118 will receive it - unless they're using CLONE_THREAD to
3119 share signals. Since we only want to report it once, we
3120 mark it as ignored for all LWPs except this one. */
3121 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp
->ptid
)),
3122 set_ignore_sigint
, NULL
);
3123 lp
->ignore_sigint
= 0;
3126 maybe_clear_ignore_sigint (lp
);
3129 /* When using hardware single-step, we need to report every signal.
3130 Otherwise, signals in pass_mask may be short-circuited
3131 except signals that might be caused by a breakpoint. */
3133 && WSTOPSIG (status
) && sigismember (&pass_mask
, WSTOPSIG (status
))
3134 && !linux_wstatus_maybe_breakpoint (status
))
3136 linux_resume_one_lwp (lp
, lp
->step
, signo
);
3137 if (debug_linux_nat
)
3138 fprintf_unfiltered (gdb_stdlog
,
3139 "LLW: %s %s, %s (preempt 'handle')\n",
3141 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3142 target_pid_to_str (lp
->ptid
),
3143 (signo
!= GDB_SIGNAL_0
3144 ? strsignal (gdb_signal_to_host (signo
))
3150 /* An interesting event. */
3152 lp
->status
= status
;
3153 save_stop_reason (lp
);
3157 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3158 their exits until all other threads in the group have exited. */
3161 check_zombie_leaders (void)
3163 struct inferior
*inf
;
3167 struct lwp_info
*leader_lp
;
3172 leader_lp
= find_lwp_pid (pid_to_ptid (inf
->pid
));
3173 if (leader_lp
!= NULL
3174 /* Check if there are other threads in the group, as we may
3175 have raced with the inferior simply exiting. */
3176 && num_lwps (inf
->pid
) > 1
3177 && linux_proc_pid_is_zombie (inf
->pid
))
3179 if (debug_linux_nat
)
3180 fprintf_unfiltered (gdb_stdlog
,
3181 "CZL: Thread group leader %d zombie "
3182 "(it exited, or another thread execd).\n",
3185 /* A leader zombie can mean one of two things:
3187 - It exited, and there's an exit status pending
3188 available, or only the leader exited (not the whole
3189 program). In the latter case, we can't waitpid the
3190 leader's exit status until all other threads are gone.
3192 - There are 3 or more threads in the group, and a thread
3193 other than the leader exec'd. See comments on exec
3194 events at the top of the file. We could try
3195 distinguishing the exit and exec cases, by waiting once
3196 more, and seeing if something comes out, but it doesn't
3197 sound useful. The previous leader _does_ go away, and
3198 we'll re-add the new one once we see the exec event
3199 (which is just the same as what would happen if the
3200 previous leader did exit voluntarily before some other
3203 if (debug_linux_nat
)
3204 fprintf_unfiltered (gdb_stdlog
,
3205 "CZL: Thread group leader %d vanished.\n",
3207 exit_lwp (leader_lp
);
3212 /* Convenience function that is called when the kernel reports an exit
3213 event. This decides whether to report the event to GDB as a
3214 process exit event, a thread exit event, or to suppress the
3218 filter_exit_event (struct lwp_info
*event_child
,
3219 struct target_waitstatus
*ourstatus
)
3221 ptid_t ptid
= event_child
->ptid
;
3223 if (num_lwps (ptid_get_pid (ptid
)) > 1)
3225 if (report_thread_events
)
3226 ourstatus
->kind
= TARGET_WAITKIND_THREAD_EXITED
;
3228 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3230 exit_lwp (event_child
);
3237 linux_nat_wait_1 (struct target_ops
*ops
,
3238 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3242 enum resume_kind last_resume_kind
;
3243 struct lwp_info
*lp
;
3246 if (debug_linux_nat
)
3247 fprintf_unfiltered (gdb_stdlog
, "LLW: enter\n");
3249 /* The first time we get here after starting a new inferior, we may
3250 not have added it to the LWP list yet - this is the earliest
3251 moment at which we know its PID. */
3252 if (ptid_is_pid (inferior_ptid
))
3254 /* Upgrade the main thread's ptid. */
3255 thread_change_ptid (inferior_ptid
,
3256 ptid_build (ptid_get_pid (inferior_ptid
),
3257 ptid_get_pid (inferior_ptid
), 0));
3259 lp
= add_initial_lwp (inferior_ptid
);
3263 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3264 block_child_signals (&prev_mask
);
3266 /* First check if there is a LWP with a wait status pending. */
3267 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3270 if (debug_linux_nat
)
3271 fprintf_unfiltered (gdb_stdlog
,
3272 "LLW: Using pending wait status %s for %s.\n",
3273 status_to_str (lp
->status
),
3274 target_pid_to_str (lp
->ptid
));
3277 /* But if we don't find a pending event, we'll have to wait. Always
3278 pull all events out of the kernel. We'll randomly select an
3279 event LWP out of all that have events, to prevent starvation. */
3285 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3288 - If the thread group leader exits while other threads in the
3289 thread group still exist, waitpid(TGID, ...) hangs. That
3290 waitpid won't return an exit status until the other threads
3291 in the group are reapped.
3293 - When a non-leader thread execs, that thread just vanishes
3294 without reporting an exit (so we'd hang if we waited for it
3295 explicitly in that case). The exec event is reported to
3299 lwpid
= my_waitpid (-1, &status
, __WALL
| WNOHANG
);
3301 if (debug_linux_nat
)
3302 fprintf_unfiltered (gdb_stdlog
,
3303 "LNW: waitpid(-1, ...) returned %d, %s\n",
3304 lwpid
, errno
? safe_strerror (errno
) : "ERRNO-OK");
3308 if (debug_linux_nat
)
3310 fprintf_unfiltered (gdb_stdlog
,
3311 "LLW: waitpid %ld received %s\n",
3312 (long) lwpid
, status_to_str (status
));
3315 linux_nat_filter_event (lwpid
, status
);
3316 /* Retry until nothing comes out of waitpid. A single
3317 SIGCHLD can indicate more than one child stopped. */
3321 /* Now that we've pulled all events out of the kernel, resume
3322 LWPs that don't have an interesting event to report. */
3323 iterate_over_lwps (minus_one_ptid
,
3324 resume_stopped_resumed_lwps
, &minus_one_ptid
);
3326 /* ... and find an LWP with a status to report to the core, if
3328 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3332 /* Check for zombie thread group leaders. Those can't be reaped
3333 until all other threads in the thread group are. */
3334 check_zombie_leaders ();
3336 /* If there are no resumed children left, bail. We'd be stuck
3337 forever in the sigsuspend call below otherwise. */
3338 if (iterate_over_lwps (ptid
, resumed_callback
, NULL
) == NULL
)
3340 if (debug_linux_nat
)
3341 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (no resumed LWP)\n");
3343 ourstatus
->kind
= TARGET_WAITKIND_NO_RESUMED
;
3345 restore_child_signals_mask (&prev_mask
);
3346 return minus_one_ptid
;
3349 /* No interesting event to report to the core. */
3351 if (target_options
& TARGET_WNOHANG
)
3353 if (debug_linux_nat
)
3354 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (ignore)\n");
3356 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3357 restore_child_signals_mask (&prev_mask
);
3358 return minus_one_ptid
;
3361 /* We shouldn't end up here unless we want to try again. */
3362 gdb_assert (lp
== NULL
);
3364 /* Block until we get an event reported with SIGCHLD. */
3365 if (debug_linux_nat
)
3366 fprintf_unfiltered (gdb_stdlog
, "LNW: about to sigsuspend\n");
3367 sigsuspend (&suspend_mask
);
3372 status
= lp
->status
;
3375 if (!target_is_non_stop_p ())
3377 /* Now stop all other LWP's ... */
3378 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
3380 /* ... and wait until all of them have reported back that
3381 they're no longer running. */
3382 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
3385 /* If we're not waiting for a specific LWP, choose an event LWP from
3386 among those that have had events. Giving equal priority to all
3387 LWPs that have had events helps prevent starvation. */
3388 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3389 select_event_lwp (ptid
, &lp
, &status
);
3391 gdb_assert (lp
!= NULL
);
3393 /* Now that we've selected our final event LWP, un-adjust its PC if
3394 it was a software breakpoint, and we can't reliably support the
3395 "stopped by software breakpoint" stop reason. */
3396 if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3397 && !USE_SIGTRAP_SIGINFO
)
3399 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3400 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3401 int decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3407 pc
= regcache_read_pc (regcache
);
3408 regcache_write_pc (regcache
, pc
+ decr_pc
);
3412 /* We'll need this to determine whether to report a SIGSTOP as
3413 GDB_SIGNAL_0. Need to take a copy because resume_clear_callback
3415 last_resume_kind
= lp
->last_resume_kind
;
3417 if (!target_is_non_stop_p ())
3419 /* In all-stop, from the core's perspective, all LWPs are now
3420 stopped until a new resume action is sent over. */
3421 iterate_over_lwps (minus_one_ptid
, resume_clear_callback
, NULL
);
3425 resume_clear_callback (lp
, NULL
);
3428 if (linux_nat_status_is_event (status
))
3430 if (debug_linux_nat
)
3431 fprintf_unfiltered (gdb_stdlog
,
3432 "LLW: trap ptid is %s.\n",
3433 target_pid_to_str (lp
->ptid
));
3436 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3438 *ourstatus
= lp
->waitstatus
;
3439 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3442 store_waitstatus (ourstatus
, status
);
3444 if (debug_linux_nat
)
3445 fprintf_unfiltered (gdb_stdlog
, "LLW: exit\n");
3447 restore_child_signals_mask (&prev_mask
);
3449 if (last_resume_kind
== resume_stop
3450 && ourstatus
->kind
== TARGET_WAITKIND_STOPPED
3451 && WSTOPSIG (status
) == SIGSTOP
)
3453 /* A thread that has been requested to stop by GDB with
3454 target_stop, and it stopped cleanly, so report as SIG0. The
3455 use of SIGSTOP is an implementation detail. */
3456 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3459 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
3460 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
3463 lp
->core
= linux_common_core_of_thread (lp
->ptid
);
3465 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
)
3466 return filter_exit_event (lp
, ourstatus
);
3471 /* Resume LWPs that are currently stopped without any pending status
3472 to report, but are resumed from the core's perspective. */
3475 resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
)
3477 ptid_t
*wait_ptid_p
= (ptid_t
*) data
;
3481 if (debug_linux_nat
)
3482 fprintf_unfiltered (gdb_stdlog
,
3483 "RSRL: NOT resuming LWP %s, not stopped\n",
3484 target_pid_to_str (lp
->ptid
));
3486 else if (!lp
->resumed
)
3488 if (debug_linux_nat
)
3489 fprintf_unfiltered (gdb_stdlog
,
3490 "RSRL: NOT resuming LWP %s, not resumed\n",
3491 target_pid_to_str (lp
->ptid
));
3493 else if (lwp_status_pending_p (lp
))
3495 if (debug_linux_nat
)
3496 fprintf_unfiltered (gdb_stdlog
,
3497 "RSRL: NOT resuming LWP %s, has pending status\n",
3498 target_pid_to_str (lp
->ptid
));
3502 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3503 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3507 CORE_ADDR pc
= regcache_read_pc (regcache
);
3508 int leave_stopped
= 0;
3510 /* Don't bother if there's a breakpoint at PC that we'd hit
3511 immediately, and we're not waiting for this LWP. */
3512 if (!ptid_match (lp
->ptid
, *wait_ptid_p
))
3514 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
3520 if (debug_linux_nat
)
3521 fprintf_unfiltered (gdb_stdlog
,
3522 "RSRL: resuming stopped-resumed LWP %s at "
3524 target_pid_to_str (lp
->ptid
),
3525 paddress (gdbarch
, pc
),
3528 linux_resume_one_lwp_throw (lp
, lp
->step
, GDB_SIGNAL_0
);
3531 CATCH (ex
, RETURN_MASK_ERROR
)
3533 if (!check_ptrace_stopped_lwp_gone (lp
))
3534 throw_exception (ex
);
3543 linux_nat_wait (struct target_ops
*ops
,
3544 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3549 if (debug_linux_nat
)
3551 char *options_string
;
3553 options_string
= target_options_to_string (target_options
);
3554 fprintf_unfiltered (gdb_stdlog
,
3555 "linux_nat_wait: [%s], [%s]\n",
3556 target_pid_to_str (ptid
),
3558 xfree (options_string
);
3561 /* Flush the async file first. */
3562 if (target_is_async_p ())
3563 async_file_flush ();
3565 /* Resume LWPs that are currently stopped without any pending status
3566 to report, but are resumed from the core's perspective. LWPs get
3567 in this state if we find them stopping at a time we're not
3568 interested in reporting the event (target_wait on a
3569 specific_process, for example, see linux_nat_wait_1), and
3570 meanwhile the event became uninteresting. Don't bother resuming
3571 LWPs we're not going to wait for if they'd stop immediately. */
3572 if (target_is_non_stop_p ())
3573 iterate_over_lwps (minus_one_ptid
, resume_stopped_resumed_lwps
, &ptid
);
3575 event_ptid
= linux_nat_wait_1 (ops
, ptid
, ourstatus
, target_options
);
3577 /* If we requested any event, and something came out, assume there
3578 may be more. If we requested a specific lwp or process, also
3579 assume there may be more. */
3580 if (target_is_async_p ()
3581 && ((ourstatus
->kind
!= TARGET_WAITKIND_IGNORE
3582 && ourstatus
->kind
!= TARGET_WAITKIND_NO_RESUMED
)
3583 || !ptid_equal (ptid
, minus_one_ptid
)))
3592 kill_one_lwp (pid_t pid
)
3594 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3597 kill_lwp (pid
, SIGKILL
);
3598 if (debug_linux_nat
)
3600 int save_errno
= errno
;
3602 fprintf_unfiltered (gdb_stdlog
,
3603 "KC: kill (SIGKILL) %ld, 0, 0 (%s)\n", (long) pid
,
3604 save_errno
? safe_strerror (save_errno
) : "OK");
3607 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3610 ptrace (PTRACE_KILL
, pid
, 0, 0);
3611 if (debug_linux_nat
)
3613 int save_errno
= errno
;
3615 fprintf_unfiltered (gdb_stdlog
,
3616 "KC: PTRACE_KILL %ld, 0, 0 (%s)\n", (long) pid
,
3617 save_errno
? safe_strerror (save_errno
) : "OK");
3621 /* Wait for an LWP to die. */
3624 kill_wait_one_lwp (pid_t pid
)
3628 /* We must make sure that there are no pending events (delayed
3629 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3630 program doesn't interfere with any following debugging session. */
3634 res
= my_waitpid (pid
, NULL
, __WALL
);
3635 if (res
!= (pid_t
) -1)
3637 if (debug_linux_nat
)
3638 fprintf_unfiltered (gdb_stdlog
,
3639 "KWC: wait %ld received unknown.\n",
3641 /* The Linux kernel sometimes fails to kill a thread
3642 completely after PTRACE_KILL; that goes from the stop
3643 point in do_fork out to the one in get_signal_to_deliver
3644 and waits again. So kill it again. */
3650 gdb_assert (res
== -1 && errno
== ECHILD
);
3653 /* Callback for iterate_over_lwps. */
3656 kill_callback (struct lwp_info
*lp
, void *data
)
3658 kill_one_lwp (ptid_get_lwp (lp
->ptid
));
3662 /* Callback for iterate_over_lwps. */
3665 kill_wait_callback (struct lwp_info
*lp
, void *data
)
3667 kill_wait_one_lwp (ptid_get_lwp (lp
->ptid
));
3671 /* Kill the fork children of any threads of inferior INF that are
3672 stopped at a fork event. */
3675 kill_unfollowed_fork_children (struct inferior
*inf
)
3677 struct thread_info
*thread
;
3679 ALL_NON_EXITED_THREADS (thread
)
3680 if (thread
->inf
== inf
)
3682 struct target_waitstatus
*ws
= &thread
->pending_follow
;
3684 if (ws
->kind
== TARGET_WAITKIND_FORKED
3685 || ws
->kind
== TARGET_WAITKIND_VFORKED
)
3687 ptid_t child_ptid
= ws
->value
.related_pid
;
3688 int child_pid
= ptid_get_pid (child_ptid
);
3689 int child_lwp
= ptid_get_lwp (child_ptid
);
3691 kill_one_lwp (child_lwp
);
3692 kill_wait_one_lwp (child_lwp
);
3694 /* Let the arch-specific native code know this process is
3696 linux_nat_forget_process (child_pid
);
3702 linux_nat_kill (struct target_ops
*ops
)
3704 /* If we're stopped while forking and we haven't followed yet,
3705 kill the other task. We need to do this first because the
3706 parent will be sleeping if this is a vfork. */
3707 kill_unfollowed_fork_children (current_inferior ());
3709 if (forks_exist_p ())
3710 linux_fork_killall ();
3713 ptid_t ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
3715 /* Stop all threads before killing them, since ptrace requires
3716 that the thread is stopped to sucessfully PTRACE_KILL. */
3717 iterate_over_lwps (ptid
, stop_callback
, NULL
);
3718 /* ... and wait until all of them have reported back that
3719 they're no longer running. */
3720 iterate_over_lwps (ptid
, stop_wait_callback
, NULL
);
3722 /* Kill all LWP's ... */
3723 iterate_over_lwps (ptid
, kill_callback
, NULL
);
3725 /* ... and wait until we've flushed all events. */
3726 iterate_over_lwps (ptid
, kill_wait_callback
, NULL
);
3729 target_mourn_inferior ();
3733 linux_nat_mourn_inferior (struct target_ops
*ops
)
3735 int pid
= ptid_get_pid (inferior_ptid
);
3737 purge_lwp_list (pid
);
3739 if (! forks_exist_p ())
3740 /* Normal case, no other forks available. */
3741 linux_ops
->to_mourn_inferior (ops
);
3743 /* Multi-fork case. The current inferior_ptid has exited, but
3744 there are other viable forks to debug. Delete the exiting
3745 one and context-switch to the first available. */
3746 linux_fork_mourn_inferior ();
3748 /* Let the arch-specific native code know this process is gone. */
3749 linux_nat_forget_process (pid
);
3752 /* Convert a native/host siginfo object, into/from the siginfo in the
3753 layout of the inferiors' architecture. */
3756 siginfo_fixup (siginfo_t
*siginfo
, gdb_byte
*inf_siginfo
, int direction
)
3760 if (linux_nat_siginfo_fixup
!= NULL
)
3761 done
= linux_nat_siginfo_fixup (siginfo
, inf_siginfo
, direction
);
3763 /* If there was no callback, or the callback didn't do anything,
3764 then just do a straight memcpy. */
3768 memcpy (siginfo
, inf_siginfo
, sizeof (siginfo_t
));
3770 memcpy (inf_siginfo
, siginfo
, sizeof (siginfo_t
));
3774 static enum target_xfer_status
3775 linux_xfer_siginfo (struct target_ops
*ops
, enum target_object object
,
3776 const char *annex
, gdb_byte
*readbuf
,
3777 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
3778 ULONGEST
*xfered_len
)
3782 gdb_byte inf_siginfo
[sizeof (siginfo_t
)];
3784 gdb_assert (object
== TARGET_OBJECT_SIGNAL_INFO
);
3785 gdb_assert (readbuf
|| writebuf
);
3787 pid
= ptid_get_lwp (inferior_ptid
);
3789 pid
= ptid_get_pid (inferior_ptid
);
3791 if (offset
> sizeof (siginfo
))
3792 return TARGET_XFER_E_IO
;
3795 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3797 return TARGET_XFER_E_IO
;
3799 /* When GDB is built as a 64-bit application, ptrace writes into
3800 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3801 inferior with a 64-bit GDB should look the same as debugging it
3802 with a 32-bit GDB, we need to convert it. GDB core always sees
3803 the converted layout, so any read/write will have to be done
3805 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
3807 if (offset
+ len
> sizeof (siginfo
))
3808 len
= sizeof (siginfo
) - offset
;
3810 if (readbuf
!= NULL
)
3811 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
3814 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
3816 /* Convert back to ptrace layout before flushing it out. */
3817 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
3820 ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3822 return TARGET_XFER_E_IO
;
3826 return TARGET_XFER_OK
;
3829 static enum target_xfer_status
3830 linux_nat_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3831 const char *annex
, gdb_byte
*readbuf
,
3832 const gdb_byte
*writebuf
,
3833 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
3835 struct cleanup
*old_chain
;
3836 enum target_xfer_status xfer
;
3838 if (object
== TARGET_OBJECT_SIGNAL_INFO
)
3839 return linux_xfer_siginfo (ops
, object
, annex
, readbuf
, writebuf
,
3840 offset
, len
, xfered_len
);
3842 /* The target is connected but no live inferior is selected. Pass
3843 this request down to a lower stratum (e.g., the executable
3845 if (object
== TARGET_OBJECT_MEMORY
&& ptid_equal (inferior_ptid
, null_ptid
))
3846 return TARGET_XFER_EOF
;
3848 old_chain
= save_inferior_ptid ();
3850 if (ptid_lwp_p (inferior_ptid
))
3851 inferior_ptid
= pid_to_ptid (ptid_get_lwp (inferior_ptid
));
3853 xfer
= linux_ops
->to_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
3854 offset
, len
, xfered_len
);
3856 do_cleanups (old_chain
);
3861 linux_nat_thread_alive (struct target_ops
*ops
, ptid_t ptid
)
3863 /* As long as a PTID is in lwp list, consider it alive. */
3864 return find_lwp_pid (ptid
) != NULL
;
3867 /* Implement the to_update_thread_list target method for this
3871 linux_nat_update_thread_list (struct target_ops
*ops
)
3873 struct lwp_info
*lwp
;
3875 /* We add/delete threads from the list as clone/exit events are
3876 processed, so just try deleting exited threads still in the
3878 delete_exited_threads ();
3880 /* Update the processor core that each lwp/thread was last seen
3884 /* Avoid accessing /proc if the thread hasn't run since we last
3885 time we fetched the thread's core. Accessing /proc becomes
3886 noticeably expensive when we have thousands of LWPs. */
3887 if (lwp
->core
== -1)
3888 lwp
->core
= linux_common_core_of_thread (lwp
->ptid
);
3893 linux_nat_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
3895 static char buf
[64];
3897 if (ptid_lwp_p (ptid
)
3898 && (ptid_get_pid (ptid
) != ptid_get_lwp (ptid
)
3899 || num_lwps (ptid_get_pid (ptid
)) > 1))
3901 snprintf (buf
, sizeof (buf
), "LWP %ld", ptid_get_lwp (ptid
));
3905 return normal_pid_to_str (ptid
);
3909 linux_nat_thread_name (struct target_ops
*self
, struct thread_info
*thr
)
3911 return linux_proc_tid_get_name (thr
->ptid
);
3914 /* Accepts an integer PID; Returns a string representing a file that
3915 can be opened to get the symbols for the child process. */
3918 linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
)
3920 return linux_proc_pid_to_exec_file (pid
);
3923 /* Implement the to_xfer_partial interface for memory reads using the /proc
3924 filesystem. Because we can use a single read() call for /proc, this
3925 can be much more efficient than banging away at PTRACE_PEEKTEXT,
3926 but it doesn't support writes. */
3928 static enum target_xfer_status
3929 linux_proc_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3930 const char *annex
, gdb_byte
*readbuf
,
3931 const gdb_byte
*writebuf
,
3932 ULONGEST offset
, LONGEST len
, ULONGEST
*xfered_len
)
3938 if (object
!= TARGET_OBJECT_MEMORY
|| !readbuf
)
3939 return TARGET_XFER_EOF
;
3941 /* Don't bother for one word. */
3942 if (len
< 3 * sizeof (long))
3943 return TARGET_XFER_EOF
;
3945 /* We could keep this file open and cache it - possibly one per
3946 thread. That requires some juggling, but is even faster. */
3947 xsnprintf (filename
, sizeof filename
, "/proc/%d/mem",
3948 ptid_get_pid (inferior_ptid
));
3949 fd
= gdb_open_cloexec (filename
, O_RDONLY
| O_LARGEFILE
, 0);
3951 return TARGET_XFER_EOF
;
3953 /* If pread64 is available, use it. It's faster if the kernel
3954 supports it (only one syscall), and it's 64-bit safe even on
3955 32-bit platforms (for instance, SPARC debugging a SPARC64
3958 if (pread64 (fd
, readbuf
, len
, offset
) != len
)
3960 if (lseek (fd
, offset
, SEEK_SET
) == -1 || read (fd
, readbuf
, len
) != len
)
3969 return TARGET_XFER_EOF
;
3973 return TARGET_XFER_OK
;
3978 /* Enumerate spufs IDs for process PID. */
3980 spu_enumerate_spu_ids (int pid
, gdb_byte
*buf
, ULONGEST offset
, ULONGEST len
)
3982 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
3984 LONGEST written
= 0;
3987 struct dirent
*entry
;
3989 xsnprintf (path
, sizeof path
, "/proc/%d/fd", pid
);
3990 dir
= opendir (path
);
3995 while ((entry
= readdir (dir
)) != NULL
)
4001 fd
= atoi (entry
->d_name
);
4005 xsnprintf (path
, sizeof path
, "/proc/%d/fd/%d", pid
, fd
);
4006 if (stat (path
, &st
) != 0)
4008 if (!S_ISDIR (st
.st_mode
))
4011 if (statfs (path
, &stfs
) != 0)
4013 if (stfs
.f_type
!= SPUFS_MAGIC
)
4016 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4018 store_unsigned_integer (buf
+ pos
- offset
, 4, byte_order
, fd
);
4028 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4029 object type, using the /proc file system. */
4031 static enum target_xfer_status
4032 linux_proc_xfer_spu (struct target_ops
*ops
, enum target_object object
,
4033 const char *annex
, gdb_byte
*readbuf
,
4034 const gdb_byte
*writebuf
,
4035 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
4040 int pid
= ptid_get_pid (inferior_ptid
);
4045 return TARGET_XFER_E_IO
;
4048 LONGEST l
= spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4051 return TARGET_XFER_E_IO
;
4053 return TARGET_XFER_EOF
;
4056 *xfered_len
= (ULONGEST
) l
;
4057 return TARGET_XFER_OK
;
4062 xsnprintf (buf
, sizeof buf
, "/proc/%d/fd/%s", pid
, annex
);
4063 fd
= gdb_open_cloexec (buf
, writebuf
? O_WRONLY
: O_RDONLY
, 0);
4065 return TARGET_XFER_E_IO
;
4068 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4071 return TARGET_XFER_EOF
;
4075 ret
= write (fd
, writebuf
, (size_t) len
);
4077 ret
= read (fd
, readbuf
, (size_t) len
);
4082 return TARGET_XFER_E_IO
;
4084 return TARGET_XFER_EOF
;
4087 *xfered_len
= (ULONGEST
) ret
;
4088 return TARGET_XFER_OK
;
4093 /* Parse LINE as a signal set and add its set bits to SIGS. */
4096 add_line_to_sigset (const char *line
, sigset_t
*sigs
)
4098 int len
= strlen (line
) - 1;
4102 if (line
[len
] != '\n')
4103 error (_("Could not parse signal set: %s"), line
);
4111 if (*p
>= '0' && *p
<= '9')
4113 else if (*p
>= 'a' && *p
<= 'f')
4114 digit
= *p
- 'a' + 10;
4116 error (_("Could not parse signal set: %s"), line
);
4121 sigaddset (sigs
, signum
+ 1);
4123 sigaddset (sigs
, signum
+ 2);
4125 sigaddset (sigs
, signum
+ 3);
4127 sigaddset (sigs
, signum
+ 4);
4133 /* Find process PID's pending signals from /proc/pid/status and set
4137 linux_proc_pending_signals (int pid
, sigset_t
*pending
,
4138 sigset_t
*blocked
, sigset_t
*ignored
)
4141 char buffer
[PATH_MAX
], fname
[PATH_MAX
];
4142 struct cleanup
*cleanup
;
4144 sigemptyset (pending
);
4145 sigemptyset (blocked
);
4146 sigemptyset (ignored
);
4147 xsnprintf (fname
, sizeof fname
, "/proc/%d/status", pid
);
4148 procfile
= gdb_fopen_cloexec (fname
, "r");
4149 if (procfile
== NULL
)
4150 error (_("Could not open %s"), fname
);
4151 cleanup
= make_cleanup_fclose (procfile
);
4153 while (fgets (buffer
, PATH_MAX
, procfile
) != NULL
)
4155 /* Normal queued signals are on the SigPnd line in the status
4156 file. However, 2.6 kernels also have a "shared" pending
4157 queue for delivering signals to a thread group, so check for
4160 Unfortunately some Red Hat kernels include the shared pending
4161 queue but not the ShdPnd status field. */
4163 if (startswith (buffer
, "SigPnd:\t"))
4164 add_line_to_sigset (buffer
+ 8, pending
);
4165 else if (startswith (buffer
, "ShdPnd:\t"))
4166 add_line_to_sigset (buffer
+ 8, pending
);
4167 else if (startswith (buffer
, "SigBlk:\t"))
4168 add_line_to_sigset (buffer
+ 8, blocked
);
4169 else if (startswith (buffer
, "SigIgn:\t"))
4170 add_line_to_sigset (buffer
+ 8, ignored
);
4173 do_cleanups (cleanup
);
4176 static enum target_xfer_status
4177 linux_nat_xfer_osdata (struct target_ops
*ops
, enum target_object object
,
4178 const char *annex
, gdb_byte
*readbuf
,
4179 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4180 ULONGEST
*xfered_len
)
4182 gdb_assert (object
== TARGET_OBJECT_OSDATA
);
4184 *xfered_len
= linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
4185 if (*xfered_len
== 0)
4186 return TARGET_XFER_EOF
;
4188 return TARGET_XFER_OK
;
4191 static enum target_xfer_status
4192 linux_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4193 const char *annex
, gdb_byte
*readbuf
,
4194 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4195 ULONGEST
*xfered_len
)
4197 enum target_xfer_status xfer
;
4199 if (object
== TARGET_OBJECT_AUXV
)
4200 return memory_xfer_auxv (ops
, object
, annex
, readbuf
, writebuf
,
4201 offset
, len
, xfered_len
);
4203 if (object
== TARGET_OBJECT_OSDATA
)
4204 return linux_nat_xfer_osdata (ops
, object
, annex
, readbuf
, writebuf
,
4205 offset
, len
, xfered_len
);
4207 if (object
== TARGET_OBJECT_SPU
)
4208 return linux_proc_xfer_spu (ops
, object
, annex
, readbuf
, writebuf
,
4209 offset
, len
, xfered_len
);
4211 /* GDB calculates all the addresses in possibly larget width of the address.
4212 Address width needs to be masked before its final use - either by
4213 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4215 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4217 if (object
== TARGET_OBJECT_MEMORY
)
4219 int addr_bit
= gdbarch_addr_bit (target_gdbarch ());
4221 if (addr_bit
< (sizeof (ULONGEST
) * HOST_CHAR_BIT
))
4222 offset
&= ((ULONGEST
) 1 << addr_bit
) - 1;
4225 xfer
= linux_proc_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4226 offset
, len
, xfered_len
);
4227 if (xfer
!= TARGET_XFER_EOF
)
4230 return super_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4231 offset
, len
, xfered_len
);
4235 cleanup_target_stop (void *arg
)
4237 ptid_t
*ptid
= (ptid_t
*) arg
;
4239 gdb_assert (arg
!= NULL
);
4242 target_resume (*ptid
, 0, GDB_SIGNAL_0
);
4245 static VEC(static_tracepoint_marker_p
) *
4246 linux_child_static_tracepoint_markers_by_strid (struct target_ops
*self
,
4249 char s
[IPA_CMD_BUF_SIZE
];
4250 struct cleanup
*old_chain
;
4251 int pid
= ptid_get_pid (inferior_ptid
);
4252 VEC(static_tracepoint_marker_p
) *markers
= NULL
;
4253 struct static_tracepoint_marker
*marker
= NULL
;
4255 ptid_t ptid
= ptid_build (pid
, 0, 0);
4260 memcpy (s
, "qTfSTM", sizeof ("qTfSTM"));
4261 s
[sizeof ("qTfSTM")] = 0;
4263 agent_run_command (pid
, s
, strlen (s
) + 1);
4265 old_chain
= make_cleanup (free_current_marker
, &marker
);
4266 make_cleanup (cleanup_target_stop
, &ptid
);
4271 marker
= XCNEW (struct static_tracepoint_marker
);
4275 parse_static_tracepoint_marker_definition (p
, &p
, marker
);
4277 if (strid
== NULL
|| strcmp (strid
, marker
->str_id
) == 0)
4279 VEC_safe_push (static_tracepoint_marker_p
,
4285 release_static_tracepoint_marker (marker
);
4286 memset (marker
, 0, sizeof (*marker
));
4289 while (*p
++ == ','); /* comma-separated list */
4291 memcpy (s
, "qTsSTM", sizeof ("qTsSTM"));
4292 s
[sizeof ("qTsSTM")] = 0;
4293 agent_run_command (pid
, s
, strlen (s
) + 1);
4297 do_cleanups (old_chain
);
4302 /* Create a prototype generic GNU/Linux target. The client can override
4303 it with local methods. */
4306 linux_target_install_ops (struct target_ops
*t
)
4308 t
->to_insert_fork_catchpoint
= linux_child_insert_fork_catchpoint
;
4309 t
->to_remove_fork_catchpoint
= linux_child_remove_fork_catchpoint
;
4310 t
->to_insert_vfork_catchpoint
= linux_child_insert_vfork_catchpoint
;
4311 t
->to_remove_vfork_catchpoint
= linux_child_remove_vfork_catchpoint
;
4312 t
->to_insert_exec_catchpoint
= linux_child_insert_exec_catchpoint
;
4313 t
->to_remove_exec_catchpoint
= linux_child_remove_exec_catchpoint
;
4314 t
->to_set_syscall_catchpoint
= linux_child_set_syscall_catchpoint
;
4315 t
->to_pid_to_exec_file
= linux_child_pid_to_exec_file
;
4316 t
->to_post_startup_inferior
= linux_child_post_startup_inferior
;
4317 t
->to_post_attach
= linux_child_post_attach
;
4318 t
->to_follow_fork
= linux_child_follow_fork
;
4320 super_xfer_partial
= t
->to_xfer_partial
;
4321 t
->to_xfer_partial
= linux_xfer_partial
;
4323 t
->to_static_tracepoint_markers_by_strid
4324 = linux_child_static_tracepoint_markers_by_strid
;
4330 struct target_ops
*t
;
4332 t
= inf_ptrace_target ();
4333 linux_target_install_ops (t
);
4339 linux_trad_target (CORE_ADDR (*register_u_offset
)(struct gdbarch
*, int, int))
4341 struct target_ops
*t
;
4343 t
= inf_ptrace_trad_target (register_u_offset
);
4344 linux_target_install_ops (t
);
4349 /* target_is_async_p implementation. */
4352 linux_nat_is_async_p (struct target_ops
*ops
)
4354 return linux_is_async_p ();
4357 /* target_can_async_p implementation. */
4360 linux_nat_can_async_p (struct target_ops
*ops
)
4362 /* NOTE: palves 2008-03-21: We're only async when the user requests
4363 it explicitly with the "set target-async" command.
4364 Someday, linux will always be async. */
4365 return target_async_permitted
;
4369 linux_nat_supports_non_stop (struct target_ops
*self
)
4374 /* to_always_non_stop_p implementation. */
4377 linux_nat_always_non_stop_p (struct target_ops
*self
)
4382 /* True if we want to support multi-process. To be removed when GDB
4383 supports multi-exec. */
4385 int linux_multi_process
= 1;
4388 linux_nat_supports_multi_process (struct target_ops
*self
)
4390 return linux_multi_process
;
4394 linux_nat_supports_disable_randomization (struct target_ops
*self
)
4396 #ifdef HAVE_PERSONALITY
4403 static int async_terminal_is_ours
= 1;
4405 /* target_terminal_inferior implementation.
4407 This is a wrapper around child_terminal_inferior to add async support. */
4410 linux_nat_terminal_inferior (struct target_ops
*self
)
4412 child_terminal_inferior (self
);
4414 /* Calls to target_terminal_*() are meant to be idempotent. */
4415 if (!async_terminal_is_ours
)
4418 delete_file_handler (input_fd
);
4419 async_terminal_is_ours
= 0;
4423 /* target_terminal_ours implementation.
4425 This is a wrapper around child_terminal_ours to add async support (and
4426 implement the target_terminal_ours vs target_terminal_ours_for_output
4427 distinction). child_terminal_ours is currently no different than
4428 child_terminal_ours_for_output.
4429 We leave target_terminal_ours_for_output alone, leaving it to
4430 child_terminal_ours_for_output. */
4433 linux_nat_terminal_ours (struct target_ops
*self
)
4435 /* GDB should never give the terminal to the inferior if the
4436 inferior is running in the background (run&, continue&, etc.),
4437 but claiming it sure should. */
4438 child_terminal_ours (self
);
4440 if (async_terminal_is_ours
)
4443 clear_sigint_trap ();
4444 add_file_handler (input_fd
, stdin_event_handler
, 0);
4445 async_terminal_is_ours
= 1;
4448 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4449 so we notice when any child changes state, and notify the
4450 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4451 above to wait for the arrival of a SIGCHLD. */
4454 sigchld_handler (int signo
)
4456 int old_errno
= errno
;
4458 if (debug_linux_nat
)
4459 ui_file_write_async_safe (gdb_stdlog
,
4460 "sigchld\n", sizeof ("sigchld\n") - 1);
4462 if (signo
== SIGCHLD
4463 && linux_nat_event_pipe
[0] != -1)
4464 async_file_mark (); /* Let the event loop know that there are
4465 events to handle. */
4470 /* Callback registered with the target events file descriptor. */
4473 handle_target_event (int error
, gdb_client_data client_data
)
4475 inferior_event_handler (INF_REG_EVENT
, NULL
);
4478 /* Create/destroy the target events pipe. Returns previous state. */
4481 linux_async_pipe (int enable
)
4483 int previous
= linux_is_async_p ();
4485 if (previous
!= enable
)
4489 /* Block child signals while we create/destroy the pipe, as
4490 their handler writes to it. */
4491 block_child_signals (&prev_mask
);
4495 if (gdb_pipe_cloexec (linux_nat_event_pipe
) == -1)
4496 internal_error (__FILE__
, __LINE__
,
4497 "creating event pipe failed.");
4499 fcntl (linux_nat_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4500 fcntl (linux_nat_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4504 close (linux_nat_event_pipe
[0]);
4505 close (linux_nat_event_pipe
[1]);
4506 linux_nat_event_pipe
[0] = -1;
4507 linux_nat_event_pipe
[1] = -1;
4510 restore_child_signals_mask (&prev_mask
);
4516 /* target_async implementation. */
4519 linux_nat_async (struct target_ops
*ops
, int enable
)
4523 if (!linux_async_pipe (1))
4525 add_file_handler (linux_nat_event_pipe
[0],
4526 handle_target_event
, NULL
);
4527 /* There may be pending events to handle. Tell the event loop
4534 delete_file_handler (linux_nat_event_pipe
[0]);
4535 linux_async_pipe (0);
4540 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4544 linux_nat_stop_lwp (struct lwp_info
*lwp
, void *data
)
4548 if (debug_linux_nat
)
4549 fprintf_unfiltered (gdb_stdlog
,
4550 "LNSL: running -> suspending %s\n",
4551 target_pid_to_str (lwp
->ptid
));
4554 if (lwp
->last_resume_kind
== resume_stop
)
4556 if (debug_linux_nat
)
4557 fprintf_unfiltered (gdb_stdlog
,
4558 "linux-nat: already stopping LWP %ld at "
4560 ptid_get_lwp (lwp
->ptid
));
4564 stop_callback (lwp
, NULL
);
4565 lwp
->last_resume_kind
= resume_stop
;
4569 /* Already known to be stopped; do nothing. */
4571 if (debug_linux_nat
)
4573 if (find_thread_ptid (lwp
->ptid
)->stop_requested
)
4574 fprintf_unfiltered (gdb_stdlog
,
4575 "LNSL: already stopped/stop_requested %s\n",
4576 target_pid_to_str (lwp
->ptid
));
4578 fprintf_unfiltered (gdb_stdlog
,
4579 "LNSL: already stopped/no "
4580 "stop_requested yet %s\n",
4581 target_pid_to_str (lwp
->ptid
));
4588 linux_nat_stop (struct target_ops
*self
, ptid_t ptid
)
4590 iterate_over_lwps (ptid
, linux_nat_stop_lwp
, NULL
);
4594 linux_nat_close (struct target_ops
*self
)
4596 /* Unregister from the event loop. */
4597 if (linux_nat_is_async_p (self
))
4598 linux_nat_async (self
, 0);
4600 if (linux_ops
->to_close
)
4601 linux_ops
->to_close (linux_ops
);
4606 /* When requests are passed down from the linux-nat layer to the
4607 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4608 used. The address space pointer is stored in the inferior object,
4609 but the common code that is passed such ptid can't tell whether
4610 lwpid is a "main" process id or not (it assumes so). We reverse
4611 look up the "main" process id from the lwp here. */
4613 static struct address_space
*
4614 linux_nat_thread_address_space (struct target_ops
*t
, ptid_t ptid
)
4616 struct lwp_info
*lwp
;
4617 struct inferior
*inf
;
4620 if (ptid_get_lwp (ptid
) == 0)
4622 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4624 lwp
= find_lwp_pid (ptid
);
4625 pid
= ptid_get_pid (lwp
->ptid
);
4629 /* A (pid,lwpid,0) ptid. */
4630 pid
= ptid_get_pid (ptid
);
4633 inf
= find_inferior_pid (pid
);
4634 gdb_assert (inf
!= NULL
);
4638 /* Return the cached value of the processor core for thread PTID. */
4641 linux_nat_core_of_thread (struct target_ops
*ops
, ptid_t ptid
)
4643 struct lwp_info
*info
= find_lwp_pid (ptid
);
4650 /* Implementation of to_filesystem_is_local. */
4653 linux_nat_filesystem_is_local (struct target_ops
*ops
)
4655 struct inferior
*inf
= current_inferior ();
4657 if (inf
->fake_pid_p
|| inf
->pid
== 0)
4660 return linux_ns_same (inf
->pid
, LINUX_NS_MNT
);
4663 /* Convert the INF argument passed to a to_fileio_* method
4664 to a process ID suitable for passing to its corresponding
4665 linux_mntns_* function. If INF is non-NULL then the
4666 caller is requesting the filesystem seen by INF. If INF
4667 is NULL then the caller is requesting the filesystem seen
4668 by the GDB. We fall back to GDB's filesystem in the case
4669 that INF is non-NULL but its PID is unknown. */
4672 linux_nat_fileio_pid_of (struct inferior
*inf
)
4674 if (inf
== NULL
|| inf
->fake_pid_p
|| inf
->pid
== 0)
4680 /* Implementation of to_fileio_open. */
4683 linux_nat_fileio_open (struct target_ops
*self
,
4684 struct inferior
*inf
, const char *filename
,
4685 int flags
, int mode
, int warn_if_slow
,
4692 if (fileio_to_host_openflags (flags
, &nat_flags
) == -1
4693 || fileio_to_host_mode (mode
, &nat_mode
) == -1)
4695 *target_errno
= FILEIO_EINVAL
;
4699 fd
= linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf
),
4700 filename
, nat_flags
, nat_mode
);
4702 *target_errno
= host_to_fileio_error (errno
);
4707 /* Implementation of to_fileio_readlink. */
4710 linux_nat_fileio_readlink (struct target_ops
*self
,
4711 struct inferior
*inf
, const char *filename
,
4718 len
= linux_mntns_readlink (linux_nat_fileio_pid_of (inf
),
4719 filename
, buf
, sizeof (buf
));
4722 *target_errno
= host_to_fileio_error (errno
);
4726 ret
= (char *) xmalloc (len
+ 1);
4727 memcpy (ret
, buf
, len
);
4732 /* Implementation of to_fileio_unlink. */
4735 linux_nat_fileio_unlink (struct target_ops
*self
,
4736 struct inferior
*inf
, const char *filename
,
4741 ret
= linux_mntns_unlink (linux_nat_fileio_pid_of (inf
),
4744 *target_errno
= host_to_fileio_error (errno
);
4749 /* Implementation of the to_thread_events method. */
4752 linux_nat_thread_events (struct target_ops
*ops
, int enable
)
4754 report_thread_events
= enable
;
4758 linux_nat_add_target (struct target_ops
*t
)
4760 /* Save the provided single-threaded target. We save this in a separate
4761 variable because another target we've inherited from (e.g. inf-ptrace)
4762 may have saved a pointer to T; we want to use it for the final
4763 process stratum target. */
4764 linux_ops_saved
= *t
;
4765 linux_ops
= &linux_ops_saved
;
4767 /* Override some methods for multithreading. */
4768 t
->to_create_inferior
= linux_nat_create_inferior
;
4769 t
->to_attach
= linux_nat_attach
;
4770 t
->to_detach
= linux_nat_detach
;
4771 t
->to_resume
= linux_nat_resume
;
4772 t
->to_wait
= linux_nat_wait
;
4773 t
->to_pass_signals
= linux_nat_pass_signals
;
4774 t
->to_xfer_partial
= linux_nat_xfer_partial
;
4775 t
->to_kill
= linux_nat_kill
;
4776 t
->to_mourn_inferior
= linux_nat_mourn_inferior
;
4777 t
->to_thread_alive
= linux_nat_thread_alive
;
4778 t
->to_update_thread_list
= linux_nat_update_thread_list
;
4779 t
->to_pid_to_str
= linux_nat_pid_to_str
;
4780 t
->to_thread_name
= linux_nat_thread_name
;
4781 t
->to_has_thread_control
= tc_schedlock
;
4782 t
->to_thread_address_space
= linux_nat_thread_address_space
;
4783 t
->to_stopped_by_watchpoint
= linux_nat_stopped_by_watchpoint
;
4784 t
->to_stopped_data_address
= linux_nat_stopped_data_address
;
4785 t
->to_stopped_by_sw_breakpoint
= linux_nat_stopped_by_sw_breakpoint
;
4786 t
->to_supports_stopped_by_sw_breakpoint
= linux_nat_supports_stopped_by_sw_breakpoint
;
4787 t
->to_stopped_by_hw_breakpoint
= linux_nat_stopped_by_hw_breakpoint
;
4788 t
->to_supports_stopped_by_hw_breakpoint
= linux_nat_supports_stopped_by_hw_breakpoint
;
4789 t
->to_thread_events
= linux_nat_thread_events
;
4791 t
->to_can_async_p
= linux_nat_can_async_p
;
4792 t
->to_is_async_p
= linux_nat_is_async_p
;
4793 t
->to_supports_non_stop
= linux_nat_supports_non_stop
;
4794 t
->to_always_non_stop_p
= linux_nat_always_non_stop_p
;
4795 t
->to_async
= linux_nat_async
;
4796 t
->to_terminal_inferior
= linux_nat_terminal_inferior
;
4797 t
->to_terminal_ours
= linux_nat_terminal_ours
;
4799 super_close
= t
->to_close
;
4800 t
->to_close
= linux_nat_close
;
4802 t
->to_stop
= linux_nat_stop
;
4804 t
->to_supports_multi_process
= linux_nat_supports_multi_process
;
4806 t
->to_supports_disable_randomization
4807 = linux_nat_supports_disable_randomization
;
4809 t
->to_core_of_thread
= linux_nat_core_of_thread
;
4811 t
->to_filesystem_is_local
= linux_nat_filesystem_is_local
;
4812 t
->to_fileio_open
= linux_nat_fileio_open
;
4813 t
->to_fileio_readlink
= linux_nat_fileio_readlink
;
4814 t
->to_fileio_unlink
= linux_nat_fileio_unlink
;
4816 /* We don't change the stratum; this target will sit at
4817 process_stratum and thread_db will set at thread_stratum. This
4818 is a little strange, since this is a multi-threaded-capable
4819 target, but we want to be on the stack below thread_db, and we
4820 also want to be used for single-threaded processes. */
4825 /* Register a method to call whenever a new thread is attached. */
4827 linux_nat_set_new_thread (struct target_ops
*t
,
4828 void (*new_thread
) (struct lwp_info
*))
4830 /* Save the pointer. We only support a single registered instance
4831 of the GNU/Linux native target, so we do not need to map this to
4833 linux_nat_new_thread
= new_thread
;
4836 /* See declaration in linux-nat.h. */
4839 linux_nat_set_new_fork (struct target_ops
*t
,
4840 linux_nat_new_fork_ftype
*new_fork
)
4842 /* Save the pointer. */
4843 linux_nat_new_fork
= new_fork
;
4846 /* See declaration in linux-nat.h. */
4849 linux_nat_set_forget_process (struct target_ops
*t
,
4850 linux_nat_forget_process_ftype
*fn
)
4852 /* Save the pointer. */
4853 linux_nat_forget_process_hook
= fn
;
4856 /* See declaration in linux-nat.h. */
4859 linux_nat_forget_process (pid_t pid
)
4861 if (linux_nat_forget_process_hook
!= NULL
)
4862 linux_nat_forget_process_hook (pid
);
4865 /* Register a method that converts a siginfo object between the layout
4866 that ptrace returns, and the layout in the architecture of the
4869 linux_nat_set_siginfo_fixup (struct target_ops
*t
,
4870 int (*siginfo_fixup
) (siginfo_t
*,
4874 /* Save the pointer. */
4875 linux_nat_siginfo_fixup
= siginfo_fixup
;
4878 /* Register a method to call prior to resuming a thread. */
4881 linux_nat_set_prepare_to_resume (struct target_ops
*t
,
4882 void (*prepare_to_resume
) (struct lwp_info
*))
4884 /* Save the pointer. */
4885 linux_nat_prepare_to_resume
= prepare_to_resume
;
4888 /* See linux-nat.h. */
4891 linux_nat_get_siginfo (ptid_t ptid
, siginfo_t
*siginfo
)
4895 pid
= ptid_get_lwp (ptid
);
4897 pid
= ptid_get_pid (ptid
);
4900 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, siginfo
);
4903 memset (siginfo
, 0, sizeof (*siginfo
));
4909 /* See nat/linux-nat.h. */
4912 current_lwp_ptid (void)
4914 gdb_assert (ptid_lwp_p (inferior_ptid
));
4915 return inferior_ptid
;
4918 /* Provide a prototype to silence -Wmissing-prototypes. */
4919 extern initialize_file_ftype _initialize_linux_nat
;
4922 _initialize_linux_nat (void)
4924 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance
,
4925 &debug_linux_nat
, _("\
4926 Set debugging of GNU/Linux lwp module."), _("\
4927 Show debugging of GNU/Linux lwp module."), _("\
4928 Enables printf debugging output."),
4930 show_debug_linux_nat
,
4931 &setdebuglist
, &showdebuglist
);
4933 add_setshow_boolean_cmd ("linux-namespaces", class_maintenance
,
4934 &debug_linux_namespaces
, _("\
4935 Set debugging of GNU/Linux namespaces module."), _("\
4936 Show debugging of GNU/Linux namespaces module."), _("\
4937 Enables printf debugging output."),
4940 &setdebuglist
, &showdebuglist
);
4942 /* Save this mask as the default. */
4943 sigprocmask (SIG_SETMASK
, NULL
, &normal_mask
);
4945 /* Install a SIGCHLD handler. */
4946 sigchld_action
.sa_handler
= sigchld_handler
;
4947 sigemptyset (&sigchld_action
.sa_mask
);
4948 sigchld_action
.sa_flags
= SA_RESTART
;
4950 /* Make it the default. */
4951 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
4953 /* Make sure we don't block SIGCHLD during a sigsuspend. */
4954 sigprocmask (SIG_SETMASK
, NULL
, &suspend_mask
);
4955 sigdelset (&suspend_mask
, SIGCHLD
);
4957 sigemptyset (&blocked_mask
);
4959 lwp_lwpid_htab_create ();
4963 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
4964 the GNU/Linux Threads library and therefore doesn't really belong
4967 /* Return the set of signals used by the threads library in *SET. */
4970 lin_thread_get_thread_signals (sigset_t
*set
)
4974 /* NPTL reserves the first two RT signals, but does not provide any
4975 way for the debugger to query the signal numbers - fortunately
4976 they don't change. */
4977 sigaddset (set
, __SIGRTMIN
);
4978 sigaddset (set
, __SIGRTMIN
+ 1);