1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001-2015 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"
27 #ifdef HAVE_TKILL_SYSCALL
29 #include <sys/syscall.h>
31 #include <sys/ptrace.h>
32 #include "linux-nat.h"
33 #include "nat/linux-ptrace.h"
34 #include "nat/linux-procfs.h"
35 #include "linux-fork.h"
36 #include "gdbthread.h"
40 #include "inf-child.h"
41 #include "inf-ptrace.h"
43 #include <sys/procfs.h> /* for elf_gregset etc. */
44 #include "elf-bfd.h" /* for elfcore_write_* */
45 #include "gregset.h" /* for gregset */
46 #include "gdbcore.h" /* for get_exec_file */
47 #include <ctype.h> /* for isdigit */
48 #include <sys/stat.h> /* for struct stat */
49 #include <fcntl.h> /* for O_RDONLY */
51 #include "event-loop.h"
52 #include "event-top.h"
54 #include <sys/types.h>
56 #include "xml-support.h"
59 #include "nat/linux-osdata.h"
60 #include "linux-tdep.h"
63 #include "tracepoint.h"
65 #include "target-descriptions.h"
66 #include "filestuff.h"
70 #define SPUFS_MAGIC 0x23c9b64e
73 #ifdef HAVE_PERSONALITY
74 # include <sys/personality.h>
75 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
76 # define ADDR_NO_RANDOMIZE 0x0040000
78 #endif /* HAVE_PERSONALITY */
80 /* This comment documents high-level logic of this file.
82 Waiting for events in sync mode
83 ===============================
85 When waiting for an event in a specific thread, we just use waitpid, passing
86 the specific pid, and not passing WNOHANG.
88 When waiting for an event in all threads, waitpid is not quite good. Prior to
89 version 2.4, Linux can either wait for event in main thread, or in secondary
90 threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might
91 miss an event. The solution is to use non-blocking waitpid, together with
92 sigsuspend. First, we use non-blocking waitpid to get an event in the main
93 process, if any. Second, we use non-blocking waitpid with the __WCLONED
94 flag to check for events in cloned processes. If nothing is found, we use
95 sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something
96 happened to a child process -- and SIGCHLD will be delivered both for events
97 in main debugged process and in cloned processes. As soon as we know there's
98 an event, we get back to calling nonblocking waitpid with and without
101 Note that SIGCHLD should be blocked between waitpid and sigsuspend calls,
102 so that we don't miss a signal. If SIGCHLD arrives in between, when it's
103 blocked, the signal becomes pending and sigsuspend immediately
104 notices it and returns.
106 Waiting for events in async mode
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
169 #define O_LARGEFILE 0
172 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
173 the use of the multi-threaded target. */
174 static struct target_ops
*linux_ops
;
175 static struct target_ops linux_ops_saved
;
177 /* The method to call, if any, when a new thread is attached. */
178 static void (*linux_nat_new_thread
) (struct lwp_info
*);
180 /* The method to call, if any, when a new fork is attached. */
181 static linux_nat_new_fork_ftype
*linux_nat_new_fork
;
183 /* The method to call, if any, when a process is no longer
185 static linux_nat_forget_process_ftype
*linux_nat_forget_process_hook
;
187 /* Hook to call prior to resuming a thread. */
188 static void (*linux_nat_prepare_to_resume
) (struct lwp_info
*);
190 /* The method to call, if any, when the siginfo object needs to be
191 converted between the layout returned by ptrace, and the layout in
192 the architecture of the inferior. */
193 static int (*linux_nat_siginfo_fixup
) (siginfo_t
*,
197 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
198 Called by our to_xfer_partial. */
199 static target_xfer_partial_ftype
*super_xfer_partial
;
201 /* The saved to_close method, inherited from inf-ptrace.c.
202 Called by our to_close. */
203 static void (*super_close
) (struct target_ops
*);
205 static unsigned int debug_linux_nat
;
207 show_debug_linux_nat (struct ui_file
*file
, int from_tty
,
208 struct cmd_list_element
*c
, const char *value
)
210 fprintf_filtered (file
, _("Debugging of GNU/Linux lwp module is %s.\n"),
214 struct simple_pid_list
218 struct simple_pid_list
*next
;
220 struct simple_pid_list
*stopped_pids
;
222 /* Async mode support. */
224 /* The read/write ends of the pipe registered as waitable file in the
226 static int linux_nat_event_pipe
[2] = { -1, -1 };
228 /* Flush the event pipe. */
231 async_file_flush (void)
238 ret
= read (linux_nat_event_pipe
[0], &buf
, 1);
240 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
243 /* Put something (anything, doesn't matter what, or how much) in event
244 pipe, so that the select/poll in the event-loop realizes we have
245 something to process. */
248 async_file_mark (void)
252 /* It doesn't really matter what the pipe contains, as long we end
253 up with something in it. Might as well flush the previous
259 ret
= write (linux_nat_event_pipe
[1], "+", 1);
261 while (ret
== -1 && errno
== EINTR
);
263 /* Ignore EAGAIN. If the pipe is full, the event loop will already
264 be awakened anyway. */
267 static int kill_lwp (int lwpid
, int signo
);
269 static int stop_callback (struct lwp_info
*lp
, void *data
);
271 static void block_child_signals (sigset_t
*prev_mask
);
272 static void restore_child_signals_mask (sigset_t
*prev_mask
);
275 static struct lwp_info
*add_lwp (ptid_t ptid
);
276 static void purge_lwp_list (int pid
);
277 static void delete_lwp (ptid_t ptid
);
278 static struct lwp_info
*find_lwp_pid (ptid_t ptid
);
280 static int lwp_status_pending_p (struct lwp_info
*lp
);
282 static int check_stopped_by_breakpoint (struct lwp_info
*lp
);
283 static int sigtrap_is_event (int status
);
284 static int (*linux_nat_status_is_event
) (int status
) = sigtrap_is_event
;
287 /* Trivial list manipulation functions to keep track of a list of
288 new stopped processes. */
290 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
292 struct simple_pid_list
*new_pid
= xmalloc (sizeof (struct simple_pid_list
));
295 new_pid
->status
= status
;
296 new_pid
->next
= *listp
;
301 in_pid_list_p (struct simple_pid_list
*list
, int pid
)
303 struct simple_pid_list
*p
;
305 for (p
= list
; p
!= NULL
; p
= p
->next
)
312 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *statusp
)
314 struct simple_pid_list
**p
;
316 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
317 if ((*p
)->pid
== pid
)
319 struct simple_pid_list
*next
= (*p
)->next
;
321 *statusp
= (*p
)->status
;
329 /* Initialize ptrace warnings and check for supported ptrace
332 ATTACHED should be nonzero iff we attached to the inferior. */
335 linux_init_ptrace (pid_t pid
, int attached
)
337 linux_enable_event_reporting (pid
, attached
);
338 linux_ptrace_init_warnings ();
342 linux_child_post_attach (struct target_ops
*self
, int pid
)
344 linux_init_ptrace (pid
, 1);
348 linux_child_post_startup_inferior (struct target_ops
*self
, ptid_t ptid
)
350 linux_init_ptrace (ptid_get_pid (ptid
), 0);
353 /* Return the number of known LWPs in the tgid given by PID. */
361 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
362 if (ptid_get_pid (lp
->ptid
) == pid
)
368 /* Call delete_lwp with prototype compatible for make_cleanup. */
371 delete_lwp_cleanup (void *lp_voidp
)
373 struct lwp_info
*lp
= lp_voidp
;
375 delete_lwp (lp
->ptid
);
378 /* Target hook for follow_fork. On entry inferior_ptid must be the
379 ptid of the followed inferior. At return, inferior_ptid will be
383 linux_child_follow_fork (struct target_ops
*ops
, int follow_child
,
388 struct lwp_info
*child_lp
= NULL
;
389 int status
= W_STOPCODE (0);
390 struct cleanup
*old_chain
;
392 int parent_pid
, child_pid
;
394 has_vforked
= (inferior_thread ()->pending_follow
.kind
395 == TARGET_WAITKIND_VFORKED
);
396 parent_pid
= ptid_get_lwp (inferior_ptid
);
398 parent_pid
= ptid_get_pid (inferior_ptid
);
400 = ptid_get_pid (inferior_thread ()->pending_follow
.value
.related_pid
);
403 /* We're already attached to the parent, by default. */
404 old_chain
= save_inferior_ptid ();
405 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
406 child_lp
= add_lwp (inferior_ptid
);
407 child_lp
->stopped
= 1;
408 child_lp
->last_resume_kind
= resume_stop
;
410 /* Detach new forked process? */
413 make_cleanup (delete_lwp_cleanup
, child_lp
);
415 if (linux_nat_prepare_to_resume
!= NULL
)
416 linux_nat_prepare_to_resume (child_lp
);
418 /* When debugging an inferior in an architecture that supports
419 hardware single stepping on a kernel without commit
420 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child
421 process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits
422 set if the parent process had them set.
423 To work around this, single step the child process
424 once before detaching to clear the flags. */
426 if (!gdbarch_software_single_step_p (target_thread_architecture
429 linux_disable_event_reporting (child_pid
);
430 if (ptrace (PTRACE_SINGLESTEP
, child_pid
, 0, 0) < 0)
431 perror_with_name (_("Couldn't do single step"));
432 if (my_waitpid (child_pid
, &status
, 0) < 0)
433 perror_with_name (_("Couldn't wait vfork process"));
436 if (WIFSTOPPED (status
))
440 signo
= WSTOPSIG (status
);
442 && !signal_pass_state (gdb_signal_from_host (signo
)))
444 ptrace (PTRACE_DETACH
, child_pid
, 0, signo
);
447 /* Resets value of inferior_ptid to parent ptid. */
448 do_cleanups (old_chain
);
452 /* Let the thread_db layer learn about this new process. */
453 check_for_thread_db ();
456 do_cleanups (old_chain
);
460 struct lwp_info
*parent_lp
;
462 parent_lp
= find_lwp_pid (pid_to_ptid (parent_pid
));
463 gdb_assert (linux_supports_tracefork () >= 0);
465 if (linux_supports_tracevforkdone ())
468 fprintf_unfiltered (gdb_stdlog
,
469 "LCFF: waiting for VFORK_DONE on %d\n",
471 parent_lp
->stopped
= 1;
473 /* We'll handle the VFORK_DONE event like any other
474 event, in target_wait. */
478 /* We can't insert breakpoints until the child has
479 finished with the shared memory region. We need to
480 wait until that happens. Ideal would be to just
482 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
483 - waitpid (parent_pid, &status, __WALL);
484 However, most architectures can't handle a syscall
485 being traced on the way out if it wasn't traced on
488 We might also think to loop, continuing the child
489 until it exits or gets a SIGTRAP. One problem is
490 that the child might call ptrace with PTRACE_TRACEME.
492 There's no simple and reliable way to figure out when
493 the vforked child will be done with its copy of the
494 shared memory. We could step it out of the syscall,
495 two instructions, let it go, and then single-step the
496 parent once. When we have hardware single-step, this
497 would work; with software single-step it could still
498 be made to work but we'd have to be able to insert
499 single-step breakpoints in the child, and we'd have
500 to insert -just- the single-step breakpoint in the
501 parent. Very awkward.
503 In the end, the best we can do is to make sure it
504 runs for a little while. Hopefully it will be out of
505 range of any breakpoints we reinsert. Usually this
506 is only the single-step breakpoint at vfork's return
510 fprintf_unfiltered (gdb_stdlog
,
511 "LCFF: no VFORK_DONE "
512 "support, sleeping a bit\n");
516 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
517 and leave it pending. The next linux_nat_resume call
518 will notice a pending event, and bypasses actually
519 resuming the inferior. */
520 parent_lp
->status
= 0;
521 parent_lp
->waitstatus
.kind
= TARGET_WAITKIND_VFORK_DONE
;
522 parent_lp
->stopped
= 1;
524 /* If we're in async mode, need to tell the event loop
525 there's something here to process. */
526 if (target_can_async_p ())
533 struct lwp_info
*child_lp
;
535 child_lp
= add_lwp (inferior_ptid
);
536 child_lp
->stopped
= 1;
537 child_lp
->last_resume_kind
= resume_stop
;
539 /* Let the thread_db layer learn about this new process. */
540 check_for_thread_db ();
548 linux_child_insert_fork_catchpoint (struct target_ops
*self
, int pid
)
550 return !linux_supports_tracefork ();
554 linux_child_remove_fork_catchpoint (struct target_ops
*self
, int pid
)
560 linux_child_insert_vfork_catchpoint (struct target_ops
*self
, int pid
)
562 return !linux_supports_tracefork ();
566 linux_child_remove_vfork_catchpoint (struct target_ops
*self
, int pid
)
572 linux_child_insert_exec_catchpoint (struct target_ops
*self
, int pid
)
574 return !linux_supports_tracefork ();
578 linux_child_remove_exec_catchpoint (struct target_ops
*self
, int pid
)
584 linux_child_set_syscall_catchpoint (struct target_ops
*self
,
585 int pid
, int needed
, int any_count
,
586 int table_size
, int *table
)
588 if (!linux_supports_tracesysgood ())
591 /* On GNU/Linux, we ignore the arguments. It means that we only
592 enable the syscall catchpoints, but do not disable them.
594 Also, we do not use the `table' information because we do not
595 filter system calls here. We let GDB do the logic for us. */
599 /* On GNU/Linux there are no real LWP's. The closest thing to LWP's
600 are processes sharing the same VM space. A multi-threaded process
601 is basically a group of such processes. However, such a grouping
602 is almost entirely a user-space issue; the kernel doesn't enforce
603 such a grouping at all (this might change in the future). In
604 general, we'll rely on the threads library (i.e. the GNU/Linux
605 Threads library) to provide such a grouping.
607 It is perfectly well possible to write a multi-threaded application
608 without the assistance of a threads library, by using the clone
609 system call directly. This module should be able to give some
610 rudimentary support for debugging such applications if developers
611 specify the CLONE_PTRACE flag in the clone system call, and are
612 using the Linux kernel 2.4 or above.
614 Note that there are some peculiarities in GNU/Linux that affect
617 - In general one should specify the __WCLONE flag to waitpid in
618 order to make it report events for any of the cloned processes
619 (and leave it out for the initial process). However, if a cloned
620 process has exited the exit status is only reported if the
621 __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
622 we cannot use it since GDB must work on older systems too.
624 - When a traced, cloned process exits and is waited for by the
625 debugger, the kernel reassigns it to the original parent and
626 keeps it around as a "zombie". Somehow, the GNU/Linux Threads
627 library doesn't notice this, which leads to the "zombie problem":
628 When debugged a multi-threaded process that spawns a lot of
629 threads will run out of processes, even if the threads exit,
630 because the "zombies" stay around. */
632 /* List of known LWPs. */
633 struct lwp_info
*lwp_list
;
636 /* Original signal mask. */
637 static sigset_t normal_mask
;
639 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
640 _initialize_linux_nat. */
641 static sigset_t suspend_mask
;
643 /* Signals to block to make that sigsuspend work. */
644 static sigset_t blocked_mask
;
646 /* SIGCHLD action. */
647 struct sigaction sigchld_action
;
649 /* Block child signals (SIGCHLD and linux threads signals), and store
650 the previous mask in PREV_MASK. */
653 block_child_signals (sigset_t
*prev_mask
)
655 /* Make sure SIGCHLD is blocked. */
656 if (!sigismember (&blocked_mask
, SIGCHLD
))
657 sigaddset (&blocked_mask
, SIGCHLD
);
659 sigprocmask (SIG_BLOCK
, &blocked_mask
, prev_mask
);
662 /* Restore child signals mask, previously returned by
663 block_child_signals. */
666 restore_child_signals_mask (sigset_t
*prev_mask
)
668 sigprocmask (SIG_SETMASK
, prev_mask
, NULL
);
671 /* Mask of signals to pass directly to the inferior. */
672 static sigset_t pass_mask
;
674 /* Update signals to pass to the inferior. */
676 linux_nat_pass_signals (struct target_ops
*self
,
677 int numsigs
, unsigned char *pass_signals
)
681 sigemptyset (&pass_mask
);
683 for (signo
= 1; signo
< NSIG
; signo
++)
685 int target_signo
= gdb_signal_from_host (signo
);
686 if (target_signo
< numsigs
&& pass_signals
[target_signo
])
687 sigaddset (&pass_mask
, signo
);
693 /* Prototypes for local functions. */
694 static int stop_wait_callback (struct lwp_info
*lp
, void *data
);
695 static int linux_thread_alive (ptid_t ptid
);
696 static char *linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
);
700 /* Destroy and free LP. */
703 lwp_free (struct lwp_info
*lp
)
705 xfree (lp
->arch_private
);
709 /* Remove all LWPs belong to PID from the lwp list. */
712 purge_lwp_list (int pid
)
714 struct lwp_info
*lp
, *lpprev
, *lpnext
;
718 for (lp
= lwp_list
; lp
; lp
= lpnext
)
722 if (ptid_get_pid (lp
->ptid
) == pid
)
727 lpprev
->next
= lp
->next
;
736 /* Add the LWP specified by PTID to the list. PTID is the first LWP
737 in the process. Return a pointer to the structure describing the
740 This differs from add_lwp in that we don't let the arch specific
741 bits know about this new thread. Current clients of this callback
742 take the opportunity to install watchpoints in the new thread, and
743 we shouldn't do that for the first thread. If we're spawning a
744 child ("run"), the thread executes the shell wrapper first, and we
745 shouldn't touch it until it execs the program we want to debug.
746 For "attach", it'd be okay to call the callback, but it's not
747 necessary, because watchpoints can't yet have been inserted into
750 static struct lwp_info
*
751 add_initial_lwp (ptid_t ptid
)
755 gdb_assert (ptid_lwp_p (ptid
));
757 lp
= (struct lwp_info
*) xmalloc (sizeof (struct lwp_info
));
759 memset (lp
, 0, sizeof (struct lwp_info
));
761 lp
->last_resume_kind
= resume_continue
;
762 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
773 /* Add the LWP specified by PID to the list. Return a pointer to the
774 structure describing the new LWP. The LWP should already be
777 static struct lwp_info
*
778 add_lwp (ptid_t ptid
)
782 lp
= add_initial_lwp (ptid
);
784 /* Let the arch specific bits know about this new thread. Current
785 clients of this callback take the opportunity to install
786 watchpoints in the new thread. We don't do this for the first
787 thread though. See add_initial_lwp. */
788 if (linux_nat_new_thread
!= NULL
)
789 linux_nat_new_thread (lp
);
794 /* Remove the LWP specified by PID from the list. */
797 delete_lwp (ptid_t ptid
)
799 struct lwp_info
*lp
, *lpprev
;
803 for (lp
= lwp_list
; lp
; lpprev
= lp
, lp
= lp
->next
)
804 if (ptid_equal (lp
->ptid
, ptid
))
811 lpprev
->next
= lp
->next
;
818 /* Return a pointer to the structure describing the LWP corresponding
819 to PID. If no corresponding LWP could be found, return NULL. */
821 static struct lwp_info
*
822 find_lwp_pid (ptid_t ptid
)
827 if (ptid_lwp_p (ptid
))
828 lwp
= ptid_get_lwp (ptid
);
830 lwp
= ptid_get_pid (ptid
);
832 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
833 if (lwp
== ptid_get_lwp (lp
->ptid
))
839 /* Call CALLBACK with its second argument set to DATA for every LWP in
840 the list. If CALLBACK returns 1 for a particular LWP, return a
841 pointer to the structure describing that LWP immediately.
842 Otherwise return NULL. */
845 iterate_over_lwps (ptid_t filter
,
846 int (*callback
) (struct lwp_info
*, void *),
849 struct lwp_info
*lp
, *lpnext
;
851 for (lp
= lwp_list
; lp
; lp
= lpnext
)
855 if (ptid_match (lp
->ptid
, filter
))
857 if ((*callback
) (lp
, data
))
865 /* Update our internal state when changing from one checkpoint to
866 another indicated by NEW_PTID. We can only switch single-threaded
867 applications, so we only create one new LWP, and the previous list
871 linux_nat_switch_fork (ptid_t new_ptid
)
875 purge_lwp_list (ptid_get_pid (inferior_ptid
));
877 lp
= add_lwp (new_ptid
);
880 /* This changes the thread's ptid while preserving the gdb thread
881 num. Also changes the inferior pid, while preserving the
883 thread_change_ptid (inferior_ptid
, new_ptid
);
885 /* We've just told GDB core that the thread changed target id, but,
886 in fact, it really is a different thread, with different register
888 registers_changed ();
891 /* Handle the exit of a single thread LP. */
894 exit_lwp (struct lwp_info
*lp
)
896 struct thread_info
*th
= find_thread_ptid (lp
->ptid
);
900 if (print_thread_events
)
901 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp
->ptid
));
903 delete_thread (lp
->ptid
);
906 delete_lwp (lp
->ptid
);
909 /* Wait for the LWP specified by LP, which we have just attached to.
910 Returns a wait status for that LWP, to cache. */
913 linux_nat_post_attach_wait (ptid_t ptid
, int first
, int *cloned
,
916 pid_t new_pid
, pid
= ptid_get_lwp (ptid
);
919 if (linux_proc_pid_is_stopped (pid
))
922 fprintf_unfiltered (gdb_stdlog
,
923 "LNPAW: Attaching to a stopped process\n");
925 /* The process is definitely stopped. It is in a job control
926 stop, unless the kernel predates the TASK_STOPPED /
927 TASK_TRACED distinction, in which case it might be in a
928 ptrace stop. Make sure it is in a ptrace stop; from there we
929 can kill it, signal it, et cetera.
931 First make sure there is a pending SIGSTOP. Since we are
932 already attached, the process can not transition from stopped
933 to running without a PTRACE_CONT; so we know this signal will
934 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
935 probably already in the queue (unless this kernel is old
936 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
937 is not an RT signal, it can only be queued once. */
938 kill_lwp (pid
, SIGSTOP
);
940 /* Finally, resume the stopped process. This will deliver the SIGSTOP
941 (or a higher priority signal, just like normal PTRACE_ATTACH). */
942 ptrace (PTRACE_CONT
, pid
, 0, 0);
945 /* Make sure the initial process is stopped. The user-level threads
946 layer might want to poke around in the inferior, and that won't
947 work if things haven't stabilized yet. */
948 new_pid
= my_waitpid (pid
, &status
, 0);
949 if (new_pid
== -1 && errno
== ECHILD
)
952 warning (_("%s is a cloned process"), target_pid_to_str (ptid
));
954 /* Try again with __WCLONE to check cloned processes. */
955 new_pid
= my_waitpid (pid
, &status
, __WCLONE
);
959 gdb_assert (pid
== new_pid
);
961 if (!WIFSTOPPED (status
))
963 /* The pid we tried to attach has apparently just exited. */
965 fprintf_unfiltered (gdb_stdlog
, "LNPAW: Failed to stop %d: %s",
966 pid
, status_to_str (status
));
970 if (WSTOPSIG (status
) != SIGSTOP
)
974 fprintf_unfiltered (gdb_stdlog
,
975 "LNPAW: Received %s after attaching\n",
976 status_to_str (status
));
982 /* Attach to the LWP specified by PID. Return 0 if successful, -1 if
983 the new LWP could not be attached, or 1 if we're already auto
984 attached to this thread, but haven't processed the
985 PTRACE_EVENT_CLONE event of its parent thread, so we just ignore
986 its existance, without considering it an error. */
989 lin_lwp_attach_lwp (ptid_t ptid
)
994 gdb_assert (ptid_lwp_p (ptid
));
996 lp
= find_lwp_pid (ptid
);
997 lwpid
= ptid_get_lwp (ptid
);
999 /* We assume that we're already attached to any LWP that has an id
1000 equal to the overall process id, and to any LWP that is already
1001 in our list of LWPs. If we're not seeing exit events from threads
1002 and we've had PID wraparound since we last tried to stop all threads,
1003 this assumption might be wrong; fortunately, this is very unlikely
1005 if (lwpid
!= ptid_get_pid (ptid
) && lp
== NULL
)
1007 int status
, cloned
= 0, signalled
= 0;
1009 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) < 0)
1011 if (linux_supports_tracefork ())
1013 /* If we haven't stopped all threads when we get here,
1014 we may have seen a thread listed in thread_db's list,
1015 but not processed the PTRACE_EVENT_CLONE yet. If
1016 that's the case, ignore this new thread, and let
1017 normal event handling discover it later. */
1018 if (in_pid_list_p (stopped_pids
, lwpid
))
1020 /* We've already seen this thread stop, but we
1021 haven't seen the PTRACE_EVENT_CLONE extended
1030 /* See if we've got a stop for this new child
1031 pending. If so, we're already attached. */
1032 gdb_assert (lwpid
> 0);
1033 new_pid
= my_waitpid (lwpid
, &status
, WNOHANG
);
1034 if (new_pid
== -1 && errno
== ECHILD
)
1035 new_pid
= my_waitpid (lwpid
, &status
, __WCLONE
| WNOHANG
);
1038 if (WIFSTOPPED (status
))
1039 add_to_pid_list (&stopped_pids
, lwpid
, status
);
1045 /* If we fail to attach to the thread, issue a warning,
1046 but continue. One way this can happen is if thread
1047 creation is interrupted; as of Linux kernel 2.6.19, a
1048 bug may place threads in the thread list and then fail
1050 warning (_("Can't attach %s: %s"), target_pid_to_str (ptid
),
1051 safe_strerror (errno
));
1055 if (debug_linux_nat
)
1056 fprintf_unfiltered (gdb_stdlog
,
1057 "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
1058 target_pid_to_str (ptid
));
1060 status
= linux_nat_post_attach_wait (ptid
, 0, &cloned
, &signalled
);
1061 if (!WIFSTOPPED (status
))
1064 lp
= add_lwp (ptid
);
1066 lp
->cloned
= cloned
;
1067 lp
->signalled
= signalled
;
1068 if (WSTOPSIG (status
) != SIGSTOP
)
1071 lp
->status
= status
;
1074 target_post_attach (ptid_get_lwp (lp
->ptid
));
1076 if (debug_linux_nat
)
1078 fprintf_unfiltered (gdb_stdlog
,
1079 "LLAL: waitpid %s received %s\n",
1080 target_pid_to_str (ptid
),
1081 status_to_str (status
));
1086 /* We assume that the LWP representing the original process is
1087 already stopped. Mark it as stopped in the data structure
1088 that the GNU/linux ptrace layer uses to keep track of
1089 threads. Note that this won't have already been done since
1090 the main thread will have, we assume, been stopped by an
1091 attach from a different layer. */
1093 lp
= add_lwp (ptid
);
1097 lp
->last_resume_kind
= resume_stop
;
1102 linux_nat_create_inferior (struct target_ops
*ops
,
1103 char *exec_file
, char *allargs
, char **env
,
1106 #ifdef HAVE_PERSONALITY
1107 int personality_orig
= 0, personality_set
= 0;
1108 #endif /* HAVE_PERSONALITY */
1110 /* The fork_child mechanism is synchronous and calls target_wait, so
1111 we have to mask the async mode. */
1113 #ifdef HAVE_PERSONALITY
1114 if (disable_randomization
)
1117 personality_orig
= personality (0xffffffff);
1118 if (errno
== 0 && !(personality_orig
& ADDR_NO_RANDOMIZE
))
1120 personality_set
= 1;
1121 personality (personality_orig
| ADDR_NO_RANDOMIZE
);
1123 if (errno
!= 0 || (personality_set
1124 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE
)))
1125 warning (_("Error disabling address space randomization: %s"),
1126 safe_strerror (errno
));
1128 #endif /* HAVE_PERSONALITY */
1130 /* Make sure we report all signals during startup. */
1131 linux_nat_pass_signals (ops
, 0, NULL
);
1133 linux_ops
->to_create_inferior (ops
, exec_file
, allargs
, env
, from_tty
);
1135 #ifdef HAVE_PERSONALITY
1136 if (personality_set
)
1139 personality (personality_orig
);
1141 warning (_("Error restoring address space randomization: %s"),
1142 safe_strerror (errno
));
1144 #endif /* HAVE_PERSONALITY */
1147 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
1148 already attached. Returns true if a new LWP is found, false
1152 attach_proc_task_lwp_callback (ptid_t ptid
)
1154 struct lwp_info
*lp
;
1156 /* Ignore LWPs we're already attached to. */
1157 lp
= find_lwp_pid (ptid
);
1160 int lwpid
= ptid_get_lwp (ptid
);
1162 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) < 0)
1166 /* Be quiet if we simply raced with the thread exiting.
1167 EPERM is returned if the thread's task still exists, and
1168 is marked as exited or zombie, as well as other
1169 conditions, so in that case, confirm the status in
1170 /proc/PID/status. */
1172 || (err
== EPERM
&& linux_proc_pid_is_gone (lwpid
)))
1174 if (debug_linux_nat
)
1176 fprintf_unfiltered (gdb_stdlog
,
1177 "Cannot attach to lwp %d: "
1178 "thread is gone (%d: %s)\n",
1179 lwpid
, err
, safe_strerror (err
));
1184 warning (_("Cannot attach to lwp %d: %s"),
1186 linux_ptrace_attach_fail_reason_string (ptid
,
1192 if (debug_linux_nat
)
1193 fprintf_unfiltered (gdb_stdlog
,
1194 "PTRACE_ATTACH %s, 0, 0 (OK)\n",
1195 target_pid_to_str (ptid
));
1197 lp
= add_lwp (ptid
);
1200 /* The next time we wait for this LWP we'll see a SIGSTOP as
1201 PTRACE_ATTACH brings it to a halt. */
1204 /* We need to wait for a stop before being able to make the
1205 next ptrace call on this LWP. */
1206 lp
->must_set_ptrace_flags
= 1;
1215 linux_nat_attach (struct target_ops
*ops
, const char *args
, int from_tty
)
1217 struct lwp_info
*lp
;
1220 volatile struct gdb_exception ex
;
1222 /* Make sure we report all signals during attach. */
1223 linux_nat_pass_signals (ops
, 0, NULL
);
1225 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
1227 linux_ops
->to_attach (ops
, args
, from_tty
);
1231 pid_t pid
= parse_pid_to_attach (args
);
1232 struct buffer buffer
;
1233 char *message
, *buffer_s
;
1235 message
= xstrdup (ex
.message
);
1236 make_cleanup (xfree
, message
);
1238 buffer_init (&buffer
);
1239 linux_ptrace_attach_fail_reason (pid
, &buffer
);
1241 buffer_grow_str0 (&buffer
, "");
1242 buffer_s
= buffer_finish (&buffer
);
1243 make_cleanup (xfree
, buffer_s
);
1245 if (*buffer_s
!= '\0')
1246 throw_error (ex
.error
, "warning: %s\n%s", buffer_s
, message
);
1248 throw_error (ex
.error
, "%s", message
);
1251 /* The ptrace base target adds the main thread with (pid,0,0)
1252 format. Decorate it with lwp info. */
1253 ptid
= ptid_build (ptid_get_pid (inferior_ptid
),
1254 ptid_get_pid (inferior_ptid
),
1256 thread_change_ptid (inferior_ptid
, ptid
);
1258 /* Add the initial process as the first LWP to the list. */
1259 lp
= add_initial_lwp (ptid
);
1261 status
= linux_nat_post_attach_wait (lp
->ptid
, 1, &lp
->cloned
,
1263 if (!WIFSTOPPED (status
))
1265 if (WIFEXITED (status
))
1267 int exit_code
= WEXITSTATUS (status
);
1269 target_terminal_ours ();
1270 target_mourn_inferior ();
1272 error (_("Unable to attach: program exited normally."));
1274 error (_("Unable to attach: program exited with code %d."),
1277 else if (WIFSIGNALED (status
))
1279 enum gdb_signal signo
;
1281 target_terminal_ours ();
1282 target_mourn_inferior ();
1284 signo
= gdb_signal_from_host (WTERMSIG (status
));
1285 error (_("Unable to attach: program terminated with signal "
1287 gdb_signal_to_name (signo
),
1288 gdb_signal_to_string (signo
));
1291 internal_error (__FILE__
, __LINE__
,
1292 _("unexpected status %d for PID %ld"),
1293 status
, (long) ptid_get_lwp (ptid
));
1298 /* Save the wait status to report later. */
1300 if (debug_linux_nat
)
1301 fprintf_unfiltered (gdb_stdlog
,
1302 "LNA: waitpid %ld, saving status %s\n",
1303 (long) ptid_get_pid (lp
->ptid
), status_to_str (status
));
1305 lp
->status
= status
;
1307 /* We must attach to every LWP. If /proc is mounted, use that to
1308 find them now. The inferior may be using raw clone instead of
1309 using pthreads. But even if it is using pthreads, thread_db
1310 walks structures in the inferior's address space to find the list
1311 of threads/LWPs, and those structures may well be corrupted.
1312 Note that once thread_db is loaded, we'll still use it to list
1313 threads and associate pthread info with each LWP. */
1314 linux_proc_attach_tgid_threads (ptid_get_pid (lp
->ptid
),
1315 attach_proc_task_lwp_callback
);
1317 if (target_can_async_p ())
1318 target_async (inferior_event_handler
, 0);
1321 /* Get pending status of LP. */
1323 get_pending_status (struct lwp_info
*lp
, int *status
)
1325 enum gdb_signal signo
= GDB_SIGNAL_0
;
1327 /* If we paused threads momentarily, we may have stored pending
1328 events in lp->status or lp->waitstatus (see stop_wait_callback),
1329 and GDB core hasn't seen any signal for those threads.
1330 Otherwise, the last signal reported to the core is found in the
1331 thread object's stop_signal.
1333 There's a corner case that isn't handled here at present. Only
1334 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1335 stop_signal make sense as a real signal to pass to the inferior.
1336 Some catchpoint related events, like
1337 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1338 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1339 those traps are debug API (ptrace in our case) related and
1340 induced; the inferior wouldn't see them if it wasn't being
1341 traced. Hence, we should never pass them to the inferior, even
1342 when set to pass state. Since this corner case isn't handled by
1343 infrun.c when proceeding with a signal, for consistency, neither
1344 do we handle it here (or elsewhere in the file we check for
1345 signal pass state). Normally SIGTRAP isn't set to pass state, so
1346 this is really a corner case. */
1348 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
1349 signo
= GDB_SIGNAL_0
; /* a pending ptrace event, not a real signal. */
1350 else if (lp
->status
)
1351 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1352 else if (non_stop
&& !is_executing (lp
->ptid
))
1354 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1356 signo
= tp
->suspend
.stop_signal
;
1360 struct target_waitstatus last
;
1363 get_last_target_status (&last_ptid
, &last
);
1365 if (ptid_get_lwp (lp
->ptid
) == ptid_get_lwp (last_ptid
))
1367 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1369 signo
= tp
->suspend
.stop_signal
;
1375 if (signo
== GDB_SIGNAL_0
)
1377 if (debug_linux_nat
)
1378 fprintf_unfiltered (gdb_stdlog
,
1379 "GPT: lwp %s has no pending signal\n",
1380 target_pid_to_str (lp
->ptid
));
1382 else if (!signal_pass_state (signo
))
1384 if (debug_linux_nat
)
1385 fprintf_unfiltered (gdb_stdlog
,
1386 "GPT: lwp %s had signal %s, "
1387 "but it is in no pass state\n",
1388 target_pid_to_str (lp
->ptid
),
1389 gdb_signal_to_string (signo
));
1393 *status
= W_STOPCODE (gdb_signal_to_host (signo
));
1395 if (debug_linux_nat
)
1396 fprintf_unfiltered (gdb_stdlog
,
1397 "GPT: lwp %s has pending signal %s\n",
1398 target_pid_to_str (lp
->ptid
),
1399 gdb_signal_to_string (signo
));
1406 detach_callback (struct lwp_info
*lp
, void *data
)
1408 gdb_assert (lp
->status
== 0 || WIFSTOPPED (lp
->status
));
1410 if (debug_linux_nat
&& lp
->status
)
1411 fprintf_unfiltered (gdb_stdlog
, "DC: Pending %s for %s on detach.\n",
1412 strsignal (WSTOPSIG (lp
->status
)),
1413 target_pid_to_str (lp
->ptid
));
1415 /* If there is a pending SIGSTOP, get rid of it. */
1418 if (debug_linux_nat
)
1419 fprintf_unfiltered (gdb_stdlog
,
1420 "DC: Sending SIGCONT to %s\n",
1421 target_pid_to_str (lp
->ptid
));
1423 kill_lwp (ptid_get_lwp (lp
->ptid
), SIGCONT
);
1427 /* We don't actually detach from the LWP that has an id equal to the
1428 overall process id just yet. */
1429 if (ptid_get_lwp (lp
->ptid
) != ptid_get_pid (lp
->ptid
))
1433 /* Pass on any pending signal for this LWP. */
1434 get_pending_status (lp
, &status
);
1436 if (linux_nat_prepare_to_resume
!= NULL
)
1437 linux_nat_prepare_to_resume (lp
);
1439 if (ptrace (PTRACE_DETACH
, ptid_get_lwp (lp
->ptid
), 0,
1440 WSTOPSIG (status
)) < 0)
1441 error (_("Can't detach %s: %s"), target_pid_to_str (lp
->ptid
),
1442 safe_strerror (errno
));
1444 if (debug_linux_nat
)
1445 fprintf_unfiltered (gdb_stdlog
,
1446 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1447 target_pid_to_str (lp
->ptid
),
1448 strsignal (WSTOPSIG (status
)));
1450 delete_lwp (lp
->ptid
);
1457 linux_nat_detach (struct target_ops
*ops
, const char *args
, int from_tty
)
1461 struct lwp_info
*main_lwp
;
1463 pid
= ptid_get_pid (inferior_ptid
);
1465 /* Don't unregister from the event loop, as there may be other
1466 inferiors running. */
1468 /* Stop all threads before detaching. ptrace requires that the
1469 thread is stopped to sucessfully detach. */
1470 iterate_over_lwps (pid_to_ptid (pid
), stop_callback
, NULL
);
1471 /* ... and wait until all of them have reported back that
1472 they're no longer running. */
1473 iterate_over_lwps (pid_to_ptid (pid
), stop_wait_callback
, NULL
);
1475 iterate_over_lwps (pid_to_ptid (pid
), detach_callback
, NULL
);
1477 /* Only the initial process should be left right now. */
1478 gdb_assert (num_lwps (ptid_get_pid (inferior_ptid
)) == 1);
1480 main_lwp
= find_lwp_pid (pid_to_ptid (pid
));
1482 /* Pass on any pending signal for the last LWP. */
1483 if ((args
== NULL
|| *args
== '\0')
1484 && get_pending_status (main_lwp
, &status
) != -1
1485 && WIFSTOPPED (status
))
1489 /* Put the signal number in ARGS so that inf_ptrace_detach will
1490 pass it along with PTRACE_DETACH. */
1492 xsnprintf (tem
, 8, "%d", (int) WSTOPSIG (status
));
1494 if (debug_linux_nat
)
1495 fprintf_unfiltered (gdb_stdlog
,
1496 "LND: Sending signal %s to %s\n",
1498 target_pid_to_str (main_lwp
->ptid
));
1501 if (linux_nat_prepare_to_resume
!= NULL
)
1502 linux_nat_prepare_to_resume (main_lwp
);
1503 delete_lwp (main_lwp
->ptid
);
1505 if (forks_exist_p ())
1507 /* Multi-fork case. The current inferior_ptid is being detached
1508 from, but there are other viable forks to debug. Detach from
1509 the current fork, and context-switch to the first
1511 linux_fork_detach (args
, from_tty
);
1514 linux_ops
->to_detach (ops
, args
, from_tty
);
1517 /* Resume execution of the inferior process. If STEP is nonzero,
1518 single-step it. If SIGNAL is nonzero, give it that signal. */
1521 linux_resume_one_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1527 /* stop_pc doubles as the PC the LWP had when it was last resumed.
1528 We only presently need that if the LWP is stepped though (to
1529 handle the case of stepping a breakpoint instruction). */
1532 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
1534 lp
->stop_pc
= regcache_read_pc (regcache
);
1539 if (linux_nat_prepare_to_resume
!= NULL
)
1540 linux_nat_prepare_to_resume (lp
);
1541 /* Convert to something the lower layer understands. */
1542 ptid
= pid_to_ptid (ptid_get_lwp (lp
->ptid
));
1543 linux_ops
->to_resume (linux_ops
, ptid
, step
, signo
);
1544 lp
->stop_reason
= LWP_STOPPED_BY_NO_REASON
;
1546 registers_changed_ptid (lp
->ptid
);
1552 resume_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1556 struct inferior
*inf
= find_inferior_ptid (lp
->ptid
);
1558 if (inf
->vfork_child
!= NULL
)
1560 if (debug_linux_nat
)
1561 fprintf_unfiltered (gdb_stdlog
,
1562 "RC: Not resuming %s (vfork parent)\n",
1563 target_pid_to_str (lp
->ptid
));
1565 else if (!lwp_status_pending_p (lp
))
1567 if (debug_linux_nat
)
1568 fprintf_unfiltered (gdb_stdlog
,
1569 "RC: Resuming sibling %s, %s, %s\n",
1570 target_pid_to_str (lp
->ptid
),
1571 (signo
!= GDB_SIGNAL_0
1572 ? strsignal (gdb_signal_to_host (signo
))
1574 step
? "step" : "resume");
1576 linux_resume_one_lwp (lp
, step
, signo
);
1580 if (debug_linux_nat
)
1581 fprintf_unfiltered (gdb_stdlog
,
1582 "RC: Not resuming sibling %s (has pending)\n",
1583 target_pid_to_str (lp
->ptid
));
1588 if (debug_linux_nat
)
1589 fprintf_unfiltered (gdb_stdlog
,
1590 "RC: Not resuming sibling %s (not stopped)\n",
1591 target_pid_to_str (lp
->ptid
));
1595 /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing.
1596 Resume LWP with the last stop signal, if it is in pass state. */
1599 linux_nat_resume_callback (struct lwp_info
*lp
, void *except
)
1601 enum gdb_signal signo
= GDB_SIGNAL_0
;
1608 struct thread_info
*thread
;
1610 thread
= find_thread_ptid (lp
->ptid
);
1613 signo
= thread
->suspend
.stop_signal
;
1614 thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
1618 resume_lwp (lp
, 0, signo
);
1623 resume_clear_callback (struct lwp_info
*lp
, void *data
)
1626 lp
->last_resume_kind
= resume_stop
;
1631 resume_set_callback (struct lwp_info
*lp
, void *data
)
1634 lp
->last_resume_kind
= resume_continue
;
1639 linux_nat_resume (struct target_ops
*ops
,
1640 ptid_t ptid
, int step
, enum gdb_signal signo
)
1642 struct lwp_info
*lp
;
1645 if (debug_linux_nat
)
1646 fprintf_unfiltered (gdb_stdlog
,
1647 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1648 step
? "step" : "resume",
1649 target_pid_to_str (ptid
),
1650 (signo
!= GDB_SIGNAL_0
1651 ? strsignal (gdb_signal_to_host (signo
)) : "0"),
1652 target_pid_to_str (inferior_ptid
));
1654 /* A specific PTID means `step only this process id'. */
1655 resume_many
= (ptid_equal (minus_one_ptid
, ptid
)
1656 || ptid_is_pid (ptid
));
1658 /* Mark the lwps we're resuming as resumed. */
1659 iterate_over_lwps (ptid
, resume_set_callback
, NULL
);
1661 /* See if it's the current inferior that should be handled
1664 lp
= find_lwp_pid (inferior_ptid
);
1666 lp
= find_lwp_pid (ptid
);
1667 gdb_assert (lp
!= NULL
);
1669 /* Remember if we're stepping. */
1670 lp
->last_resume_kind
= step
? resume_step
: resume_continue
;
1672 /* If we have a pending wait status for this thread, there is no
1673 point in resuming the process. But first make sure that
1674 linux_nat_wait won't preemptively handle the event - we
1675 should never take this short-circuit if we are going to
1676 leave LP running, since we have skipped resuming all the
1677 other threads. This bit of code needs to be synchronized
1678 with linux_nat_wait. */
1680 if (lp
->status
&& WIFSTOPPED (lp
->status
))
1683 && WSTOPSIG (lp
->status
)
1684 && sigismember (&pass_mask
, WSTOPSIG (lp
->status
)))
1686 if (debug_linux_nat
)
1687 fprintf_unfiltered (gdb_stdlog
,
1688 "LLR: Not short circuiting for ignored "
1689 "status 0x%x\n", lp
->status
);
1691 /* FIXME: What should we do if we are supposed to continue
1692 this thread with a signal? */
1693 gdb_assert (signo
== GDB_SIGNAL_0
);
1694 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1699 if (lwp_status_pending_p (lp
))
1701 /* FIXME: What should we do if we are supposed to continue
1702 this thread with a signal? */
1703 gdb_assert (signo
== GDB_SIGNAL_0
);
1705 if (debug_linux_nat
)
1706 fprintf_unfiltered (gdb_stdlog
,
1707 "LLR: Short circuiting for status 0x%x\n",
1710 if (target_can_async_p ())
1712 target_async (inferior_event_handler
, 0);
1713 /* Tell the event loop we have something to process. */
1720 iterate_over_lwps (ptid
, linux_nat_resume_callback
, lp
);
1722 linux_resume_one_lwp (lp
, step
, signo
);
1724 if (debug_linux_nat
)
1725 fprintf_unfiltered (gdb_stdlog
,
1726 "LLR: %s %s, %s (resume event thread)\n",
1727 step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1728 target_pid_to_str (ptid
),
1729 (signo
!= GDB_SIGNAL_0
1730 ? strsignal (gdb_signal_to_host (signo
)) : "0"));
1732 if (target_can_async_p ())
1733 target_async (inferior_event_handler
, 0);
1736 /* Send a signal to an LWP. */
1739 kill_lwp (int lwpid
, int signo
)
1741 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1742 fails, then we are not using nptl threads and we should be using kill. */
1744 #ifdef HAVE_TKILL_SYSCALL
1746 static int tkill_failed
;
1753 ret
= syscall (__NR_tkill
, lwpid
, signo
);
1754 if (errno
!= ENOSYS
)
1761 return kill (lwpid
, signo
);
1764 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1765 event, check if the core is interested in it: if not, ignore the
1766 event, and keep waiting; otherwise, we need to toggle the LWP's
1767 syscall entry/exit status, since the ptrace event itself doesn't
1768 indicate it, and report the trap to higher layers. */
1771 linux_handle_syscall_trap (struct lwp_info
*lp
, int stopping
)
1773 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1774 struct gdbarch
*gdbarch
= target_thread_architecture (lp
->ptid
);
1775 int syscall_number
= (int) gdbarch_get_syscall_number (gdbarch
, lp
->ptid
);
1779 /* If we're stopping threads, there's a SIGSTOP pending, which
1780 makes it so that the LWP reports an immediate syscall return,
1781 followed by the SIGSTOP. Skip seeing that "return" using
1782 PTRACE_CONT directly, and let stop_wait_callback collect the
1783 SIGSTOP. Later when the thread is resumed, a new syscall
1784 entry event. If we didn't do this (and returned 0), we'd
1785 leave a syscall entry pending, and our caller, by using
1786 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1787 itself. Later, when the user re-resumes this LWP, we'd see
1788 another syscall entry event and we'd mistake it for a return.
1790 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1791 (leaving immediately with LWP->signalled set, without issuing
1792 a PTRACE_CONT), it would still be problematic to leave this
1793 syscall enter pending, as later when the thread is resumed,
1794 it would then see the same syscall exit mentioned above,
1795 followed by the delayed SIGSTOP, while the syscall didn't
1796 actually get to execute. It seems it would be even more
1797 confusing to the user. */
1799 if (debug_linux_nat
)
1800 fprintf_unfiltered (gdb_stdlog
,
1801 "LHST: ignoring syscall %d "
1802 "for LWP %ld (stopping threads), "
1803 "resuming with PTRACE_CONT for SIGSTOP\n",
1805 ptid_get_lwp (lp
->ptid
));
1807 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1808 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
1813 if (catch_syscall_enabled ())
1815 /* Always update the entry/return state, even if this particular
1816 syscall isn't interesting to the core now. In async mode,
1817 the user could install a new catchpoint for this syscall
1818 between syscall enter/return, and we'll need to know to
1819 report a syscall return if that happens. */
1820 lp
->syscall_state
= (lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1821 ? TARGET_WAITKIND_SYSCALL_RETURN
1822 : TARGET_WAITKIND_SYSCALL_ENTRY
);
1824 if (catching_syscall_number (syscall_number
))
1826 /* Alright, an event to report. */
1827 ourstatus
->kind
= lp
->syscall_state
;
1828 ourstatus
->value
.syscall_number
= syscall_number
;
1830 if (debug_linux_nat
)
1831 fprintf_unfiltered (gdb_stdlog
,
1832 "LHST: stopping for %s of syscall %d"
1835 == TARGET_WAITKIND_SYSCALL_ENTRY
1836 ? "entry" : "return",
1838 ptid_get_lwp (lp
->ptid
));
1842 if (debug_linux_nat
)
1843 fprintf_unfiltered (gdb_stdlog
,
1844 "LHST: ignoring %s of syscall %d "
1846 lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1847 ? "entry" : "return",
1849 ptid_get_lwp (lp
->ptid
));
1853 /* If we had been syscall tracing, and hence used PT_SYSCALL
1854 before on this LWP, it could happen that the user removes all
1855 syscall catchpoints before we get to process this event.
1856 There are two noteworthy issues here:
1858 - When stopped at a syscall entry event, resuming with
1859 PT_STEP still resumes executing the syscall and reports a
1862 - Only PT_SYSCALL catches syscall enters. If we last
1863 single-stepped this thread, then this event can't be a
1864 syscall enter. If we last single-stepped this thread, this
1865 has to be a syscall exit.
1867 The points above mean that the next resume, be it PT_STEP or
1868 PT_CONTINUE, can not trigger a syscall trace event. */
1869 if (debug_linux_nat
)
1870 fprintf_unfiltered (gdb_stdlog
,
1871 "LHST: caught syscall event "
1872 "with no syscall catchpoints."
1873 " %d for LWP %ld, ignoring\n",
1875 ptid_get_lwp (lp
->ptid
));
1876 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1879 /* The core isn't interested in this event. For efficiency, avoid
1880 stopping all threads only to have the core resume them all again.
1881 Since we're not stopping threads, if we're still syscall tracing
1882 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1883 subsequent syscall. Simply resume using the inf-ptrace layer,
1884 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1886 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
1890 /* Handle a GNU/Linux extended wait response. If we see a clone
1891 event, we need to add the new LWP to our list (and not report the
1892 trap to higher layers). This function returns non-zero if the
1893 event should be ignored and we should wait again. If STOPPING is
1894 true, the new LWP remains stopped, otherwise it is continued. */
1897 linux_handle_extended_wait (struct lwp_info
*lp
, int status
,
1900 int pid
= ptid_get_lwp (lp
->ptid
);
1901 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1902 int event
= linux_ptrace_get_extended_event (status
);
1904 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
1905 || event
== PTRACE_EVENT_CLONE
)
1907 unsigned long new_pid
;
1910 ptrace (PTRACE_GETEVENTMSG
, pid
, 0, &new_pid
);
1912 /* If we haven't already seen the new PID stop, wait for it now. */
1913 if (! pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
1915 /* The new child has a pending SIGSTOP. We can't affect it until it
1916 hits the SIGSTOP, but we're already attached. */
1917 ret
= my_waitpid (new_pid
, &status
,
1918 (event
== PTRACE_EVENT_CLONE
) ? __WCLONE
: 0);
1920 perror_with_name (_("waiting for new child"));
1921 else if (ret
!= new_pid
)
1922 internal_error (__FILE__
, __LINE__
,
1923 _("wait returned unexpected PID %d"), ret
);
1924 else if (!WIFSTOPPED (status
))
1925 internal_error (__FILE__
, __LINE__
,
1926 _("wait returned unexpected status 0x%x"), status
);
1929 ourstatus
->value
.related_pid
= ptid_build (new_pid
, new_pid
, 0);
1931 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
)
1933 /* The arch-specific native code may need to know about new
1934 forks even if those end up never mapped to an
1936 if (linux_nat_new_fork
!= NULL
)
1937 linux_nat_new_fork (lp
, new_pid
);
1940 if (event
== PTRACE_EVENT_FORK
1941 && linux_fork_checkpointing_p (ptid_get_pid (lp
->ptid
)))
1943 /* Handle checkpointing by linux-fork.c here as a special
1944 case. We don't want the follow-fork-mode or 'catch fork'
1945 to interfere with this. */
1947 /* This won't actually modify the breakpoint list, but will
1948 physically remove the breakpoints from the child. */
1949 detach_breakpoints (ptid_build (new_pid
, new_pid
, 0));
1951 /* Retain child fork in ptrace (stopped) state. */
1952 if (!find_fork_pid (new_pid
))
1955 /* Report as spurious, so that infrun doesn't want to follow
1956 this fork. We're actually doing an infcall in
1958 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
1960 /* Report the stop to the core. */
1964 if (event
== PTRACE_EVENT_FORK
)
1965 ourstatus
->kind
= TARGET_WAITKIND_FORKED
;
1966 else if (event
== PTRACE_EVENT_VFORK
)
1967 ourstatus
->kind
= TARGET_WAITKIND_VFORKED
;
1970 struct lwp_info
*new_lp
;
1972 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
1974 if (debug_linux_nat
)
1975 fprintf_unfiltered (gdb_stdlog
,
1976 "LHEW: Got clone event "
1977 "from LWP %d, new child is LWP %ld\n",
1980 new_lp
= add_lwp (ptid_build (ptid_get_pid (lp
->ptid
), new_pid
, 0));
1982 new_lp
->stopped
= 1;
1984 if (WSTOPSIG (status
) != SIGSTOP
)
1986 /* This can happen if someone starts sending signals to
1987 the new thread before it gets a chance to run, which
1988 have a lower number than SIGSTOP (e.g. SIGUSR1).
1989 This is an unlikely case, and harder to handle for
1990 fork / vfork than for clone, so we do not try - but
1991 we handle it for clone events here. We'll send
1992 the other signal on to the thread below. */
1994 new_lp
->signalled
= 1;
1998 struct thread_info
*tp
;
2000 /* When we stop for an event in some other thread, and
2001 pull the thread list just as this thread has cloned,
2002 we'll have seen the new thread in the thread_db list
2003 before handling the CLONE event (glibc's
2004 pthread_create adds the new thread to the thread list
2005 before clone'ing, and has the kernel fill in the
2006 thread's tid on the clone call with
2007 CLONE_PARENT_SETTID). If that happened, and the core
2008 had requested the new thread to stop, we'll have
2009 killed it with SIGSTOP. But since SIGSTOP is not an
2010 RT signal, it can only be queued once. We need to be
2011 careful to not resume the LWP if we wanted it to
2012 stop. In that case, we'll leave the SIGSTOP pending.
2013 It will later be reported as GDB_SIGNAL_0. */
2014 tp
= find_thread_ptid (new_lp
->ptid
);
2015 if (tp
!= NULL
&& tp
->stop_requested
)
2016 new_lp
->last_resume_kind
= resume_stop
;
2023 /* Add the new thread to GDB's lists as soon as possible
2026 1) the frontend doesn't have to wait for a stop to
2029 2) we tag it with the correct running state. */
2031 /* If the thread_db layer is active, let it know about
2032 this new thread, and add it to GDB's list. */
2033 if (!thread_db_attach_lwp (new_lp
->ptid
))
2035 /* We're not using thread_db. Add it to GDB's
2037 target_post_attach (ptid_get_lwp (new_lp
->ptid
));
2038 add_thread (new_lp
->ptid
);
2043 set_running (new_lp
->ptid
, 1);
2044 set_executing (new_lp
->ptid
, 1);
2045 /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced
2047 new_lp
->last_resume_kind
= resume_continue
;
2053 /* We created NEW_LP so it cannot yet contain STATUS. */
2054 gdb_assert (new_lp
->status
== 0);
2056 /* Save the wait status to report later. */
2057 if (debug_linux_nat
)
2058 fprintf_unfiltered (gdb_stdlog
,
2059 "LHEW: waitpid of new LWP %ld, "
2060 "saving status %s\n",
2061 (long) ptid_get_lwp (new_lp
->ptid
),
2062 status_to_str (status
));
2063 new_lp
->status
= status
;
2066 /* Note the need to use the low target ops to resume, to
2067 handle resuming with PT_SYSCALL if we have syscall
2071 new_lp
->resumed
= 1;
2075 gdb_assert (new_lp
->last_resume_kind
== resume_continue
);
2076 if (debug_linux_nat
)
2077 fprintf_unfiltered (gdb_stdlog
,
2078 "LHEW: resuming new LWP %ld\n",
2079 ptid_get_lwp (new_lp
->ptid
));
2080 linux_resume_one_lwp (new_lp
, 0, GDB_SIGNAL_0
);
2084 if (debug_linux_nat
)
2085 fprintf_unfiltered (gdb_stdlog
,
2086 "LHEW: resuming parent LWP %d\n", pid
);
2087 linux_resume_one_lwp (lp
, 0, GDB_SIGNAL_0
);
2094 if (event
== PTRACE_EVENT_EXEC
)
2096 if (debug_linux_nat
)
2097 fprintf_unfiltered (gdb_stdlog
,
2098 "LHEW: Got exec event from LWP %ld\n",
2099 ptid_get_lwp (lp
->ptid
));
2101 ourstatus
->kind
= TARGET_WAITKIND_EXECD
;
2102 ourstatus
->value
.execd_pathname
2103 = xstrdup (linux_child_pid_to_exec_file (NULL
, pid
));
2105 /* The thread that execed must have been resumed, but, when a
2106 thread execs, it changes its tid to the tgid, and the old
2107 tgid thread might have not been resumed. */
2112 if (event
== PTRACE_EVENT_VFORK_DONE
)
2114 if (current_inferior ()->waiting_for_vfork_done
)
2116 if (debug_linux_nat
)
2117 fprintf_unfiltered (gdb_stdlog
,
2118 "LHEW: Got expected PTRACE_EVENT_"
2119 "VFORK_DONE from LWP %ld: stopping\n",
2120 ptid_get_lwp (lp
->ptid
));
2122 ourstatus
->kind
= TARGET_WAITKIND_VFORK_DONE
;
2126 if (debug_linux_nat
)
2127 fprintf_unfiltered (gdb_stdlog
,
2128 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2129 "from LWP %ld: resuming\n",
2130 ptid_get_lwp (lp
->ptid
));
2131 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
2135 internal_error (__FILE__
, __LINE__
,
2136 _("unknown ptrace event %d"), event
);
2139 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2143 wait_lwp (struct lwp_info
*lp
)
2147 int thread_dead
= 0;
2150 gdb_assert (!lp
->stopped
);
2151 gdb_assert (lp
->status
== 0);
2153 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2154 block_child_signals (&prev_mask
);
2158 /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind
2159 was right and we should just call sigsuspend. */
2161 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), &status
, WNOHANG
);
2162 if (pid
== -1 && errno
== ECHILD
)
2163 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), &status
, __WCLONE
| WNOHANG
);
2164 if (pid
== -1 && errno
== ECHILD
)
2166 /* The thread has previously exited. We need to delete it
2167 now because, for some vendor 2.4 kernels with NPTL
2168 support backported, there won't be an exit event unless
2169 it is the main thread. 2.6 kernels will report an exit
2170 event for each thread that exits, as expected. */
2172 if (debug_linux_nat
)
2173 fprintf_unfiltered (gdb_stdlog
, "WL: %s vanished.\n",
2174 target_pid_to_str (lp
->ptid
));
2179 /* Bugs 10970, 12702.
2180 Thread group leader may have exited in which case we'll lock up in
2181 waitpid if there are other threads, even if they are all zombies too.
2182 Basically, we're not supposed to use waitpid this way.
2183 __WCLONE is not applicable for the leader so we can't use that.
2184 LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED
2185 process; it gets ESRCH both for the zombie and for running processes.
2187 As a workaround, check if we're waiting for the thread group leader and
2188 if it's a zombie, and avoid calling waitpid if it is.
2190 This is racy, what if the tgl becomes a zombie right after we check?
2191 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2192 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2194 if (ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
)
2195 && linux_proc_pid_is_zombie (ptid_get_lwp (lp
->ptid
)))
2198 if (debug_linux_nat
)
2199 fprintf_unfiltered (gdb_stdlog
,
2200 "WL: Thread group leader %s vanished.\n",
2201 target_pid_to_str (lp
->ptid
));
2205 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2206 get invoked despite our caller had them intentionally blocked by
2207 block_child_signals. This is sensitive only to the loop of
2208 linux_nat_wait_1 and there if we get called my_waitpid gets called
2209 again before it gets to sigsuspend so we can safely let the handlers
2210 get executed here. */
2212 if (debug_linux_nat
)
2213 fprintf_unfiltered (gdb_stdlog
, "WL: about to sigsuspend\n");
2214 sigsuspend (&suspend_mask
);
2217 restore_child_signals_mask (&prev_mask
);
2221 gdb_assert (pid
== ptid_get_lwp (lp
->ptid
));
2223 if (debug_linux_nat
)
2225 fprintf_unfiltered (gdb_stdlog
,
2226 "WL: waitpid %s received %s\n",
2227 target_pid_to_str (lp
->ptid
),
2228 status_to_str (status
));
2231 /* Check if the thread has exited. */
2232 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2235 if (debug_linux_nat
)
2236 fprintf_unfiltered (gdb_stdlog
, "WL: %s exited.\n",
2237 target_pid_to_str (lp
->ptid
));
2247 gdb_assert (WIFSTOPPED (status
));
2250 if (lp
->must_set_ptrace_flags
)
2252 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
2254 linux_enable_event_reporting (ptid_get_lwp (lp
->ptid
), inf
->attach_flag
);
2255 lp
->must_set_ptrace_flags
= 0;
2258 /* Handle GNU/Linux's syscall SIGTRAPs. */
2259 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2261 /* No longer need the sysgood bit. The ptrace event ends up
2262 recorded in lp->waitstatus if we care for it. We can carry
2263 on handling the event like a regular SIGTRAP from here
2265 status
= W_STOPCODE (SIGTRAP
);
2266 if (linux_handle_syscall_trap (lp
, 1))
2267 return wait_lwp (lp
);
2270 /* Handle GNU/Linux's extended waitstatus for trace events. */
2271 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
2272 && linux_is_extended_waitstatus (status
))
2274 if (debug_linux_nat
)
2275 fprintf_unfiltered (gdb_stdlog
,
2276 "WL: Handling extended status 0x%06x\n",
2278 if (linux_handle_extended_wait (lp
, status
, 1))
2279 return wait_lwp (lp
);
2285 /* Send a SIGSTOP to LP. */
2288 stop_callback (struct lwp_info
*lp
, void *data
)
2290 if (!lp
->stopped
&& !lp
->signalled
)
2294 if (debug_linux_nat
)
2296 fprintf_unfiltered (gdb_stdlog
,
2297 "SC: kill %s **<SIGSTOP>**\n",
2298 target_pid_to_str (lp
->ptid
));
2301 ret
= kill_lwp (ptid_get_lwp (lp
->ptid
), SIGSTOP
);
2302 if (debug_linux_nat
)
2304 fprintf_unfiltered (gdb_stdlog
,
2305 "SC: lwp kill %d %s\n",
2307 errno
? safe_strerror (errno
) : "ERRNO-OK");
2311 gdb_assert (lp
->status
== 0);
2317 /* Request a stop on LWP. */
2320 linux_stop_lwp (struct lwp_info
*lwp
)
2322 stop_callback (lwp
, NULL
);
2325 /* Return non-zero if LWP PID has a pending SIGINT. */
2328 linux_nat_has_pending_sigint (int pid
)
2330 sigset_t pending
, blocked
, ignored
;
2332 linux_proc_pending_signals (pid
, &pending
, &blocked
, &ignored
);
2334 if (sigismember (&pending
, SIGINT
)
2335 && !sigismember (&ignored
, SIGINT
))
2341 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2344 set_ignore_sigint (struct lwp_info
*lp
, void *data
)
2346 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2347 flag to consume the next one. */
2348 if (lp
->stopped
&& lp
->status
!= 0 && WIFSTOPPED (lp
->status
)
2349 && WSTOPSIG (lp
->status
) == SIGINT
)
2352 lp
->ignore_sigint
= 1;
2357 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2358 This function is called after we know the LWP has stopped; if the LWP
2359 stopped before the expected SIGINT was delivered, then it will never have
2360 arrived. Also, if the signal was delivered to a shared queue and consumed
2361 by a different thread, it will never be delivered to this LWP. */
2364 maybe_clear_ignore_sigint (struct lwp_info
*lp
)
2366 if (!lp
->ignore_sigint
)
2369 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp
->ptid
)))
2371 if (debug_linux_nat
)
2372 fprintf_unfiltered (gdb_stdlog
,
2373 "MCIS: Clearing bogus flag for %s\n",
2374 target_pid_to_str (lp
->ptid
));
2375 lp
->ignore_sigint
= 0;
2379 /* Fetch the possible triggered data watchpoint info and store it in
2382 On some archs, like x86, that use debug registers to set
2383 watchpoints, it's possible that the way to know which watched
2384 address trapped, is to check the register that is used to select
2385 which address to watch. Problem is, between setting the watchpoint
2386 and reading back which data address trapped, the user may change
2387 the set of watchpoints, and, as a consequence, GDB changes the
2388 debug registers in the inferior. To avoid reading back a stale
2389 stopped-data-address when that happens, we cache in LP the fact
2390 that a watchpoint trapped, and the corresponding data address, as
2391 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2392 registers meanwhile, we have the cached data we can rely on. */
2395 check_stopped_by_watchpoint (struct lwp_info
*lp
)
2397 struct cleanup
*old_chain
;
2399 if (linux_ops
->to_stopped_by_watchpoint
== NULL
)
2402 old_chain
= save_inferior_ptid ();
2403 inferior_ptid
= lp
->ptid
;
2405 if (linux_ops
->to_stopped_by_watchpoint (linux_ops
))
2407 lp
->stop_reason
= LWP_STOPPED_BY_WATCHPOINT
;
2409 if (linux_ops
->to_stopped_data_address
!= NULL
)
2410 lp
->stopped_data_address_p
=
2411 linux_ops
->to_stopped_data_address (¤t_target
,
2412 &lp
->stopped_data_address
);
2414 lp
->stopped_data_address_p
= 0;
2417 do_cleanups (old_chain
);
2419 return lp
->stop_reason
== LWP_STOPPED_BY_WATCHPOINT
;
2422 /* Called when the LWP stopped for a trap that could be explained by a
2423 watchpoint or a breakpoint. */
2426 save_sigtrap (struct lwp_info
*lp
)
2428 gdb_assert (lp
->stop_reason
== LWP_STOPPED_BY_NO_REASON
);
2429 gdb_assert (lp
->status
!= 0);
2431 if (check_stopped_by_watchpoint (lp
))
2434 if (linux_nat_status_is_event (lp
->status
))
2435 check_stopped_by_breakpoint (lp
);
2438 /* Returns true if the LWP had stopped for a watchpoint. */
2441 linux_nat_stopped_by_watchpoint (struct target_ops
*ops
)
2443 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2445 gdb_assert (lp
!= NULL
);
2447 return lp
->stop_reason
== LWP_STOPPED_BY_WATCHPOINT
;
2451 linux_nat_stopped_data_address (struct target_ops
*ops
, CORE_ADDR
*addr_p
)
2453 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2455 gdb_assert (lp
!= NULL
);
2457 *addr_p
= lp
->stopped_data_address
;
2459 return lp
->stopped_data_address_p
;
2462 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2465 sigtrap_is_event (int status
)
2467 return WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
;
2470 /* Set alternative SIGTRAP-like events recognizer. If
2471 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2475 linux_nat_set_status_is_event (struct target_ops
*t
,
2476 int (*status_is_event
) (int status
))
2478 linux_nat_status_is_event
= status_is_event
;
2481 /* Wait until LP is stopped. */
2484 stop_wait_callback (struct lwp_info
*lp
, void *data
)
2486 struct inferior
*inf
= find_inferior_ptid (lp
->ptid
);
2488 /* If this is a vfork parent, bail out, it is not going to report
2489 any SIGSTOP until the vfork is done with. */
2490 if (inf
->vfork_child
!= NULL
)
2497 status
= wait_lwp (lp
);
2501 if (lp
->ignore_sigint
&& WIFSTOPPED (status
)
2502 && WSTOPSIG (status
) == SIGINT
)
2504 lp
->ignore_sigint
= 0;
2507 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
2509 if (debug_linux_nat
)
2510 fprintf_unfiltered (gdb_stdlog
,
2511 "PTRACE_CONT %s, 0, 0 (%s) "
2512 "(discarding SIGINT)\n",
2513 target_pid_to_str (lp
->ptid
),
2514 errno
? safe_strerror (errno
) : "OK");
2516 return stop_wait_callback (lp
, NULL
);
2519 maybe_clear_ignore_sigint (lp
);
2521 if (WSTOPSIG (status
) != SIGSTOP
)
2523 /* The thread was stopped with a signal other than SIGSTOP. */
2525 if (debug_linux_nat
)
2526 fprintf_unfiltered (gdb_stdlog
,
2527 "SWC: Pending event %s in %s\n",
2528 status_to_str ((int) status
),
2529 target_pid_to_str (lp
->ptid
));
2531 /* Save the sigtrap event. */
2532 lp
->status
= status
;
2533 gdb_assert (lp
->signalled
);
2538 /* We caught the SIGSTOP that we intended to catch, so
2539 there's no SIGSTOP pending. */
2541 if (debug_linux_nat
)
2542 fprintf_unfiltered (gdb_stdlog
,
2543 "SWC: Delayed SIGSTOP caught for %s.\n",
2544 target_pid_to_str (lp
->ptid
));
2546 /* Reset SIGNALLED only after the stop_wait_callback call
2547 above as it does gdb_assert on SIGNALLED. */
2555 /* Return non-zero if LP has a wait status pending. Discard the
2556 pending event and resume the LWP if the event that originally
2557 caused the stop became uninteresting. */
2560 status_callback (struct lwp_info
*lp
, void *data
)
2562 /* Only report a pending wait status if we pretend that this has
2563 indeed been resumed. */
2567 if (lp
->stop_reason
== LWP_STOPPED_BY_SW_BREAKPOINT
2568 || lp
->stop_reason
== LWP_STOPPED_BY_HW_BREAKPOINT
)
2570 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
2571 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
2575 gdb_assert (lp
->status
!= 0);
2577 pc
= regcache_read_pc (regcache
);
2579 if (pc
!= lp
->stop_pc
)
2581 if (debug_linux_nat
)
2582 fprintf_unfiltered (gdb_stdlog
,
2583 "SC: PC of %s changed. was=%s, now=%s\n",
2584 target_pid_to_str (lp
->ptid
),
2585 paddress (target_gdbarch (), lp
->stop_pc
),
2586 paddress (target_gdbarch (), pc
));
2589 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
2591 if (debug_linux_nat
)
2592 fprintf_unfiltered (gdb_stdlog
,
2593 "SC: previous breakpoint of %s, at %s gone\n",
2594 target_pid_to_str (lp
->ptid
),
2595 paddress (target_gdbarch (), lp
->stop_pc
));
2602 if (debug_linux_nat
)
2603 fprintf_unfiltered (gdb_stdlog
,
2604 "SC: pending event of %s cancelled.\n",
2605 target_pid_to_str (lp
->ptid
));
2608 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
2614 return lwp_status_pending_p (lp
);
2617 /* Return non-zero if LP isn't stopped. */
2620 running_callback (struct lwp_info
*lp
, void *data
)
2622 return (!lp
->stopped
2623 || (lwp_status_pending_p (lp
) && lp
->resumed
));
2626 /* Count the LWP's that have had events. */
2629 count_events_callback (struct lwp_info
*lp
, void *data
)
2633 gdb_assert (count
!= NULL
);
2635 /* Select only resumed LWPs that have an event pending. */
2636 if (lp
->resumed
&& lwp_status_pending_p (lp
))
2642 /* Select the LWP (if any) that is currently being single-stepped. */
2645 select_singlestep_lwp_callback (struct lwp_info
*lp
, void *data
)
2647 if (lp
->last_resume_kind
== resume_step
2654 /* Returns true if LP has a status pending. */
2657 lwp_status_pending_p (struct lwp_info
*lp
)
2659 /* We check for lp->waitstatus in addition to lp->status, because we
2660 can have pending process exits recorded in lp->status and
2661 W_EXITCODE(0,0) happens to be 0. */
2662 return lp
->status
!= 0 || lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
;
2665 /* Select the Nth LWP that has had a SIGTRAP event. */
2668 select_event_lwp_callback (struct lwp_info
*lp
, void *data
)
2670 int *selector
= data
;
2672 gdb_assert (selector
!= NULL
);
2674 /* Select only resumed LWPs that have an event pending. */
2675 if (lp
->resumed
&& lwp_status_pending_p (lp
))
2676 if ((*selector
)-- == 0)
2682 /* Called when the LWP got a signal/trap that could be explained by a
2683 software or hardware breakpoint. */
2686 check_stopped_by_breakpoint (struct lwp_info
*lp
)
2688 /* Arrange for a breakpoint to be hit again later. We don't keep
2689 the SIGTRAP status and don't forward the SIGTRAP signal to the
2690 LWP. We will handle the current event, eventually we will resume
2691 this LWP, and this breakpoint will trap again.
2693 If we do not do this, then we run the risk that the user will
2694 delete or disable the breakpoint, but the LWP will have already
2697 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
2698 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
2702 pc
= regcache_read_pc (regcache
);
2703 sw_bp_pc
= pc
- target_decr_pc_after_break (gdbarch
);
2705 if ((!lp
->step
|| lp
->stop_pc
== sw_bp_pc
)
2706 && software_breakpoint_inserted_here_p (get_regcache_aspace (regcache
),
2709 /* The LWP was either continued, or stepped a software
2710 breakpoint instruction. */
2711 if (debug_linux_nat
)
2712 fprintf_unfiltered (gdb_stdlog
,
2713 "CB: Push back software breakpoint for %s\n",
2714 target_pid_to_str (lp
->ptid
));
2716 /* Back up the PC if necessary. */
2718 regcache_write_pc (regcache
, sw_bp_pc
);
2720 lp
->stop_pc
= sw_bp_pc
;
2721 lp
->stop_reason
= LWP_STOPPED_BY_SW_BREAKPOINT
;
2725 if (hardware_breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
2727 if (debug_linux_nat
)
2728 fprintf_unfiltered (gdb_stdlog
,
2729 "CB: Push back hardware breakpoint for %s\n",
2730 target_pid_to_str (lp
->ptid
));
2733 lp
->stop_reason
= LWP_STOPPED_BY_HW_BREAKPOINT
;
2740 /* Select one LWP out of those that have events pending. */
2743 select_event_lwp (ptid_t filter
, struct lwp_info
**orig_lp
, int *status
)
2746 int random_selector
;
2747 struct lwp_info
*event_lp
= NULL
;
2749 /* Record the wait status for the original LWP. */
2750 (*orig_lp
)->status
= *status
;
2752 /* In all-stop, give preference to the LWP that is being
2753 single-stepped. There will be at most one, and it will be the
2754 LWP that the core is most interested in. If we didn't do this,
2755 then we'd have to handle pending step SIGTRAPs somehow in case
2756 the core later continues the previously-stepped thread, as
2757 otherwise we'd report the pending SIGTRAP then, and the core, not
2758 having stepped the thread, wouldn't understand what the trap was
2759 for, and therefore would report it to the user as a random
2763 event_lp
= iterate_over_lwps (filter
,
2764 select_singlestep_lwp_callback
, NULL
);
2765 if (event_lp
!= NULL
)
2767 if (debug_linux_nat
)
2768 fprintf_unfiltered (gdb_stdlog
,
2769 "SEL: Select single-step %s\n",
2770 target_pid_to_str (event_lp
->ptid
));
2774 if (event_lp
== NULL
)
2776 /* Pick one at random, out of those which have had events. */
2778 /* First see how many events we have. */
2779 iterate_over_lwps (filter
, count_events_callback
, &num_events
);
2781 /* Now randomly pick a LWP out of those that have had
2783 random_selector
= (int)
2784 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
2786 if (debug_linux_nat
&& num_events
> 1)
2787 fprintf_unfiltered (gdb_stdlog
,
2788 "SEL: Found %d events, selecting #%d\n",
2789 num_events
, random_selector
);
2791 event_lp
= iterate_over_lwps (filter
,
2792 select_event_lwp_callback
,
2796 if (event_lp
!= NULL
)
2798 /* Switch the event LWP. */
2799 *orig_lp
= event_lp
;
2800 *status
= event_lp
->status
;
2803 /* Flush the wait status for the event LWP. */
2804 (*orig_lp
)->status
= 0;
2807 /* Return non-zero if LP has been resumed. */
2810 resumed_callback (struct lwp_info
*lp
, void *data
)
2815 /* Stop an active thread, verify it still exists, then resume it. If
2816 the thread ends up with a pending status, then it is not resumed,
2817 and *DATA (really a pointer to int), is set. */
2820 stop_and_resume_callback (struct lwp_info
*lp
, void *data
)
2824 ptid_t ptid
= lp
->ptid
;
2826 stop_callback (lp
, NULL
);
2827 stop_wait_callback (lp
, NULL
);
2829 /* Resume if the lwp still exists, and the core wanted it
2831 lp
= find_lwp_pid (ptid
);
2834 if (lp
->last_resume_kind
== resume_stop
2835 && !lwp_status_pending_p (lp
))
2837 /* The core wanted the LWP to stop. Even if it stopped
2838 cleanly (with SIGSTOP), leave the event pending. */
2839 if (debug_linux_nat
)
2840 fprintf_unfiltered (gdb_stdlog
,
2841 "SARC: core wanted LWP %ld stopped "
2842 "(leaving SIGSTOP pending)\n",
2843 ptid_get_lwp (lp
->ptid
));
2844 lp
->status
= W_STOPCODE (SIGSTOP
);
2847 if (!lwp_status_pending_p (lp
))
2849 if (debug_linux_nat
)
2850 fprintf_unfiltered (gdb_stdlog
,
2851 "SARC: re-resuming LWP %ld\n",
2852 ptid_get_lwp (lp
->ptid
));
2853 resume_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
2857 if (debug_linux_nat
)
2858 fprintf_unfiltered (gdb_stdlog
,
2859 "SARC: not re-resuming LWP %ld "
2861 ptid_get_lwp (lp
->ptid
));
2868 /* Check if we should go on and pass this event to common code.
2869 Return the affected lwp if we are, or NULL otherwise. */
2871 static struct lwp_info
*
2872 linux_nat_filter_event (int lwpid
, int status
)
2874 struct lwp_info
*lp
;
2875 int event
= linux_ptrace_get_extended_event (status
);
2877 lp
= find_lwp_pid (pid_to_ptid (lwpid
));
2879 /* Check for stop events reported by a process we didn't already
2880 know about - anything not already in our LWP list.
2882 If we're expecting to receive stopped processes after
2883 fork, vfork, and clone events, then we'll just add the
2884 new one to our list and go back to waiting for the event
2885 to be reported - the stopped process might be returned
2886 from waitpid before or after the event is.
2888 But note the case of a non-leader thread exec'ing after the
2889 leader having exited, and gone from our lists. The non-leader
2890 thread changes its tid to the tgid. */
2892 if (WIFSTOPPED (status
) && lp
== NULL
2893 && (WSTOPSIG (status
) == SIGTRAP
&& event
== PTRACE_EVENT_EXEC
))
2895 /* A multi-thread exec after we had seen the leader exiting. */
2896 if (debug_linux_nat
)
2897 fprintf_unfiltered (gdb_stdlog
,
2898 "LLW: Re-adding thread group leader LWP %d.\n",
2901 lp
= add_lwp (ptid_build (lwpid
, lwpid
, 0));
2904 add_thread (lp
->ptid
);
2907 if (WIFSTOPPED (status
) && !lp
)
2909 add_to_pid_list (&stopped_pids
, lwpid
, status
);
2913 /* Make sure we don't report an event for the exit of an LWP not in
2914 our list, i.e. not part of the current process. This can happen
2915 if we detach from a program we originally forked and then it
2917 if (!WIFSTOPPED (status
) && !lp
)
2920 /* This LWP is stopped now. (And if dead, this prevents it from
2921 ever being continued.) */
2924 if (WIFSTOPPED (status
) && lp
->must_set_ptrace_flags
)
2926 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
2928 linux_enable_event_reporting (ptid_get_lwp (lp
->ptid
), inf
->attach_flag
);
2929 lp
->must_set_ptrace_flags
= 0;
2932 /* Handle GNU/Linux's syscall SIGTRAPs. */
2933 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2935 /* No longer need the sysgood bit. The ptrace event ends up
2936 recorded in lp->waitstatus if we care for it. We can carry
2937 on handling the event like a regular SIGTRAP from here
2939 status
= W_STOPCODE (SIGTRAP
);
2940 if (linux_handle_syscall_trap (lp
, 0))
2944 /* Handle GNU/Linux's extended waitstatus for trace events. */
2945 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
2946 && linux_is_extended_waitstatus (status
))
2948 if (debug_linux_nat
)
2949 fprintf_unfiltered (gdb_stdlog
,
2950 "LLW: Handling extended status 0x%06x\n",
2952 if (linux_handle_extended_wait (lp
, status
, 0))
2956 /* Check if the thread has exited. */
2957 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2959 if (num_lwps (ptid_get_pid (lp
->ptid
)) > 1)
2961 /* If this is the main thread, we must stop all threads and
2962 verify if they are still alive. This is because in the
2963 nptl thread model on Linux 2.4, there is no signal issued
2964 for exiting LWPs other than the main thread. We only get
2965 the main thread exit signal once all child threads have
2966 already exited. If we stop all the threads and use the
2967 stop_wait_callback to check if they have exited we can
2968 determine whether this signal should be ignored or
2969 whether it means the end of the debugged application,
2970 regardless of which threading model is being used. */
2971 if (ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
))
2973 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp
->ptid
)),
2974 stop_and_resume_callback
, NULL
);
2977 if (debug_linux_nat
)
2978 fprintf_unfiltered (gdb_stdlog
,
2979 "LLW: %s exited.\n",
2980 target_pid_to_str (lp
->ptid
));
2982 if (num_lwps (ptid_get_pid (lp
->ptid
)) > 1)
2984 /* If there is at least one more LWP, then the exit signal
2985 was not the end of the debugged application and should be
2992 gdb_assert (lp
->resumed
);
2994 if (debug_linux_nat
)
2995 fprintf_unfiltered (gdb_stdlog
,
2996 "Process %ld exited\n",
2997 ptid_get_lwp (lp
->ptid
));
2999 /* This was the last lwp in the process. Since events are
3000 serialized to GDB core, we may not be able report this one
3001 right now, but GDB core and the other target layers will want
3002 to be notified about the exit code/signal, leave the status
3003 pending for the next time we're able to report it. */
3005 /* Dead LWP's aren't expected to reported a pending sigstop. */
3008 /* Store the pending event in the waitstatus, because
3009 W_EXITCODE(0,0) == 0. */
3010 store_waitstatus (&lp
->waitstatus
, status
);
3014 /* Check if the current LWP has previously exited. In the nptl
3015 thread model, LWPs other than the main thread do not issue
3016 signals when they exit so we must check whenever the thread has
3017 stopped. A similar check is made in stop_wait_callback(). */
3018 if (num_lwps (ptid_get_pid (lp
->ptid
)) > 1 && !linux_thread_alive (lp
->ptid
))
3020 ptid_t ptid
= pid_to_ptid (ptid_get_pid (lp
->ptid
));
3022 if (debug_linux_nat
)
3023 fprintf_unfiltered (gdb_stdlog
,
3024 "LLW: %s exited.\n",
3025 target_pid_to_str (lp
->ptid
));
3029 /* Make sure there is at least one thread running. */
3030 gdb_assert (iterate_over_lwps (ptid
, running_callback
, NULL
));
3032 /* Discard the event. */
3036 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3037 an attempt to stop an LWP. */
3039 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGSTOP
)
3041 if (debug_linux_nat
)
3042 fprintf_unfiltered (gdb_stdlog
,
3043 "LLW: Delayed SIGSTOP caught for %s.\n",
3044 target_pid_to_str (lp
->ptid
));
3048 if (lp
->last_resume_kind
!= resume_stop
)
3050 /* This is a delayed SIGSTOP. */
3052 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
3053 if (debug_linux_nat
)
3054 fprintf_unfiltered (gdb_stdlog
,
3055 "LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
3057 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3058 target_pid_to_str (lp
->ptid
));
3060 gdb_assert (lp
->resumed
);
3062 /* Discard the event. */
3067 /* Make sure we don't report a SIGINT that we have already displayed
3068 for another thread. */
3069 if (lp
->ignore_sigint
3070 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGINT
)
3072 if (debug_linux_nat
)
3073 fprintf_unfiltered (gdb_stdlog
,
3074 "LLW: Delayed SIGINT caught for %s.\n",
3075 target_pid_to_str (lp
->ptid
));
3077 /* This is a delayed SIGINT. */
3078 lp
->ignore_sigint
= 0;
3080 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
3081 if (debug_linux_nat
)
3082 fprintf_unfiltered (gdb_stdlog
,
3083 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3085 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3086 target_pid_to_str (lp
->ptid
));
3087 gdb_assert (lp
->resumed
);
3089 /* Discard the event. */
3093 /* Don't report signals that GDB isn't interested in, such as
3094 signals that are neither printed nor stopped upon. Stopping all
3095 threads can be a bit time-consuming so if we want decent
3096 performance with heavily multi-threaded programs, especially when
3097 they're using a high frequency timer, we'd better avoid it if we
3099 if (WIFSTOPPED (status
))
3101 enum gdb_signal signo
= gdb_signal_from_host (WSTOPSIG (status
));
3105 /* Only do the below in all-stop, as we currently use SIGSTOP
3106 to implement target_stop (see linux_nat_stop) in
3108 if (signo
== GDB_SIGNAL_INT
&& signal_pass_state (signo
) == 0)
3110 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3111 forwarded to the entire process group, that is, all LWPs
3112 will receive it - unless they're using CLONE_THREAD to
3113 share signals. Since we only want to report it once, we
3114 mark it as ignored for all LWPs except this one. */
3115 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp
->ptid
)),
3116 set_ignore_sigint
, NULL
);
3117 lp
->ignore_sigint
= 0;
3120 maybe_clear_ignore_sigint (lp
);
3123 /* When using hardware single-step, we need to report every signal.
3124 Otherwise, signals in pass_mask may be short-circuited. */
3126 && WSTOPSIG (status
) && sigismember (&pass_mask
, WSTOPSIG (status
)))
3128 linux_resume_one_lwp (lp
, lp
->step
, signo
);
3129 if (debug_linux_nat
)
3130 fprintf_unfiltered (gdb_stdlog
,
3131 "LLW: %s %s, %s (preempt 'handle')\n",
3133 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3134 target_pid_to_str (lp
->ptid
),
3135 (signo
!= GDB_SIGNAL_0
3136 ? strsignal (gdb_signal_to_host (signo
))
3142 /* An interesting event. */
3144 lp
->status
= status
;
3149 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3150 their exits until all other threads in the group have exited. */
3153 check_zombie_leaders (void)
3155 struct inferior
*inf
;
3159 struct lwp_info
*leader_lp
;
3164 leader_lp
= find_lwp_pid (pid_to_ptid (inf
->pid
));
3165 if (leader_lp
!= NULL
3166 /* Check if there are other threads in the group, as we may
3167 have raced with the inferior simply exiting. */
3168 && num_lwps (inf
->pid
) > 1
3169 && linux_proc_pid_is_zombie (inf
->pid
))
3171 if (debug_linux_nat
)
3172 fprintf_unfiltered (gdb_stdlog
,
3173 "CZL: Thread group leader %d zombie "
3174 "(it exited, or another thread execd).\n",
3177 /* A leader zombie can mean one of two things:
3179 - It exited, and there's an exit status pending
3180 available, or only the leader exited (not the whole
3181 program). In the latter case, we can't waitpid the
3182 leader's exit status until all other threads are gone.
3184 - There are 3 or more threads in the group, and a thread
3185 other than the leader exec'd. On an exec, the Linux
3186 kernel destroys all other threads (except the execing
3187 one) in the thread group, and resets the execing thread's
3188 tid to the tgid. No exit notification is sent for the
3189 execing thread -- from the ptracer's perspective, it
3190 appears as though the execing thread just vanishes.
3191 Until we reap all other threads except the leader and the
3192 execing thread, the leader will be zombie, and the
3193 execing thread will be in `D (disc sleep)'. As soon as
3194 all other threads are reaped, the execing thread changes
3195 it's tid to the tgid, and the previous (zombie) leader
3196 vanishes, giving place to the "new" leader. We could try
3197 distinguishing the exit and exec cases, by waiting once
3198 more, and seeing if something comes out, but it doesn't
3199 sound useful. The previous leader _does_ go away, and
3200 we'll re-add the new one once we see the exec event
3201 (which is just the same as what would happen if the
3202 previous leader did exit voluntarily before some other
3205 if (debug_linux_nat
)
3206 fprintf_unfiltered (gdb_stdlog
,
3207 "CZL: Thread group leader %d vanished.\n",
3209 exit_lwp (leader_lp
);
3215 linux_nat_wait_1 (struct target_ops
*ops
,
3216 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3220 enum resume_kind last_resume_kind
;
3221 struct lwp_info
*lp
;
3224 if (debug_linux_nat
)
3225 fprintf_unfiltered (gdb_stdlog
, "LLW: enter\n");
3227 /* The first time we get here after starting a new inferior, we may
3228 not have added it to the LWP list yet - this is the earliest
3229 moment at which we know its PID. */
3230 if (ptid_is_pid (inferior_ptid
))
3232 /* Upgrade the main thread's ptid. */
3233 thread_change_ptid (inferior_ptid
,
3234 ptid_build (ptid_get_pid (inferior_ptid
),
3235 ptid_get_pid (inferior_ptid
), 0));
3237 lp
= add_initial_lwp (inferior_ptid
);
3241 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3242 block_child_signals (&prev_mask
);
3244 /* First check if there is a LWP with a wait status pending. */
3245 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3248 if (debug_linux_nat
)
3249 fprintf_unfiltered (gdb_stdlog
,
3250 "LLW: Using pending wait status %s for %s.\n",
3251 status_to_str (lp
->status
),
3252 target_pid_to_str (lp
->ptid
));
3255 if (!target_can_async_p ())
3257 /* Causes SIGINT to be passed on to the attached process. */
3261 /* But if we don't find a pending event, we'll have to wait. Always
3262 pull all events out of the kernel. We'll randomly select an
3263 event LWP out of all that have events, to prevent starvation. */
3269 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3272 - If the thread group leader exits while other threads in the
3273 thread group still exist, waitpid(TGID, ...) hangs. That
3274 waitpid won't return an exit status until the other threads
3275 in the group are reapped.
3277 - When a non-leader thread execs, that thread just vanishes
3278 without reporting an exit (so we'd hang if we waited for it
3279 explicitly in that case). The exec event is reported to
3283 lwpid
= my_waitpid (-1, &status
, __WCLONE
| WNOHANG
);
3284 if (lwpid
== 0 || (lwpid
== -1 && errno
== ECHILD
))
3285 lwpid
= my_waitpid (-1, &status
, WNOHANG
);
3287 if (debug_linux_nat
)
3288 fprintf_unfiltered (gdb_stdlog
,
3289 "LNW: waitpid(-1, ...) returned %d, %s\n",
3290 lwpid
, errno
? safe_strerror (errno
) : "ERRNO-OK");
3294 if (debug_linux_nat
)
3296 fprintf_unfiltered (gdb_stdlog
,
3297 "LLW: waitpid %ld received %s\n",
3298 (long) lwpid
, status_to_str (status
));
3301 linux_nat_filter_event (lwpid
, status
);
3302 /* Retry until nothing comes out of waitpid. A single
3303 SIGCHLD can indicate more than one child stopped. */
3307 /* Now that we've pulled all events out of the kernel, check if
3308 there's any LWP with a status to report to the core. */
3309 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3313 /* Check for zombie thread group leaders. Those can't be reaped
3314 until all other threads in the thread group are. */
3315 check_zombie_leaders ();
3317 /* If there are no resumed children left, bail. We'd be stuck
3318 forever in the sigsuspend call below otherwise. */
3319 if (iterate_over_lwps (ptid
, resumed_callback
, NULL
) == NULL
)
3321 if (debug_linux_nat
)
3322 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (no resumed LWP)\n");
3324 ourstatus
->kind
= TARGET_WAITKIND_NO_RESUMED
;
3326 if (!target_can_async_p ())
3327 clear_sigint_trap ();
3329 restore_child_signals_mask (&prev_mask
);
3330 return minus_one_ptid
;
3333 /* No interesting event to report to the core. */
3335 if (target_options
& TARGET_WNOHANG
)
3337 if (debug_linux_nat
)
3338 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (ignore)\n");
3340 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3341 restore_child_signals_mask (&prev_mask
);
3342 return minus_one_ptid
;
3345 /* We shouldn't end up here unless we want to try again. */
3346 gdb_assert (lp
== NULL
);
3348 /* Block until we get an event reported with SIGCHLD. */
3349 if (debug_linux_nat
)
3350 fprintf_unfiltered (gdb_stdlog
, "LNW: about to sigsuspend\n");
3351 sigsuspend (&suspend_mask
);
3354 if (!target_can_async_p ())
3355 clear_sigint_trap ();
3359 status
= lp
->status
;
3364 /* Now stop all other LWP's ... */
3365 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
3367 /* ... and wait until all of them have reported back that
3368 they're no longer running. */
3369 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
3372 /* If we're not waiting for a specific LWP, choose an event LWP from
3373 among those that have had events. Giving equal priority to all
3374 LWPs that have had events helps prevent starvation. */
3375 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3376 select_event_lwp (ptid
, &lp
, &status
);
3378 gdb_assert (lp
!= NULL
);
3380 /* Now that we've selected our final event LWP, un-adjust its PC if
3381 it was a software breakpoint. */
3382 if (lp
->stop_reason
== LWP_STOPPED_BY_SW_BREAKPOINT
)
3384 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3385 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3386 int decr_pc
= target_decr_pc_after_break (gdbarch
);
3392 pc
= regcache_read_pc (regcache
);
3393 regcache_write_pc (regcache
, pc
+ decr_pc
);
3397 /* We'll need this to determine whether to report a SIGSTOP as
3398 GDB_SIGNAL_0. Need to take a copy because resume_clear_callback
3400 last_resume_kind
= lp
->last_resume_kind
;
3404 /* In all-stop, from the core's perspective, all LWPs are now
3405 stopped until a new resume action is sent over. */
3406 iterate_over_lwps (minus_one_ptid
, resume_clear_callback
, NULL
);
3410 resume_clear_callback (lp
, NULL
);
3413 if (linux_nat_status_is_event (status
))
3415 if (debug_linux_nat
)
3416 fprintf_unfiltered (gdb_stdlog
,
3417 "LLW: trap ptid is %s.\n",
3418 target_pid_to_str (lp
->ptid
));
3421 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3423 *ourstatus
= lp
->waitstatus
;
3424 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3427 store_waitstatus (ourstatus
, status
);
3429 if (debug_linux_nat
)
3430 fprintf_unfiltered (gdb_stdlog
, "LLW: exit\n");
3432 restore_child_signals_mask (&prev_mask
);
3434 if (last_resume_kind
== resume_stop
3435 && ourstatus
->kind
== TARGET_WAITKIND_STOPPED
3436 && WSTOPSIG (status
) == SIGSTOP
)
3438 /* A thread that has been requested to stop by GDB with
3439 target_stop, and it stopped cleanly, so report as SIG0. The
3440 use of SIGSTOP is an implementation detail. */
3441 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3444 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
3445 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
3448 lp
->core
= linux_common_core_of_thread (lp
->ptid
);
3453 /* Resume LWPs that are currently stopped without any pending status
3454 to report, but are resumed from the core's perspective. */
3457 resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
)
3459 ptid_t
*wait_ptid_p
= data
;
3463 && !lwp_status_pending_p (lp
))
3465 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3466 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3467 CORE_ADDR pc
= regcache_read_pc (regcache
);
3469 gdb_assert (is_executing (lp
->ptid
));
3471 /* Don't bother if there's a breakpoint at PC that we'd hit
3472 immediately, and we're not waiting for this LWP. */
3473 if (!ptid_match (lp
->ptid
, *wait_ptid_p
))
3475 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
3479 if (debug_linux_nat
)
3480 fprintf_unfiltered (gdb_stdlog
,
3481 "RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n",
3482 target_pid_to_str (lp
->ptid
),
3483 paddress (gdbarch
, pc
),
3486 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
3493 linux_nat_wait (struct target_ops
*ops
,
3494 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3499 if (debug_linux_nat
)
3501 char *options_string
;
3503 options_string
= target_options_to_string (target_options
);
3504 fprintf_unfiltered (gdb_stdlog
,
3505 "linux_nat_wait: [%s], [%s]\n",
3506 target_pid_to_str (ptid
),
3508 xfree (options_string
);
3511 /* Flush the async file first. */
3512 if (target_can_async_p ())
3513 async_file_flush ();
3515 /* Resume LWPs that are currently stopped without any pending status
3516 to report, but are resumed from the core's perspective. LWPs get
3517 in this state if we find them stopping at a time we're not
3518 interested in reporting the event (target_wait on a
3519 specific_process, for example, see linux_nat_wait_1), and
3520 meanwhile the event became uninteresting. Don't bother resuming
3521 LWPs we're not going to wait for if they'd stop immediately. */
3523 iterate_over_lwps (minus_one_ptid
, resume_stopped_resumed_lwps
, &ptid
);
3525 event_ptid
= linux_nat_wait_1 (ops
, ptid
, ourstatus
, target_options
);
3527 /* If we requested any event, and something came out, assume there
3528 may be more. If we requested a specific lwp or process, also
3529 assume there may be more. */
3530 if (target_can_async_p ()
3531 && ((ourstatus
->kind
!= TARGET_WAITKIND_IGNORE
3532 && ourstatus
->kind
!= TARGET_WAITKIND_NO_RESUMED
)
3533 || !ptid_equal (ptid
, minus_one_ptid
)))
3536 /* Get ready for the next event. */
3537 if (target_can_async_p ())
3538 target_async (inferior_event_handler
, 0);
3544 kill_callback (struct lwp_info
*lp
, void *data
)
3546 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3549 kill_lwp (ptid_get_lwp (lp
->ptid
), SIGKILL
);
3550 if (debug_linux_nat
)
3552 int save_errno
= errno
;
3554 fprintf_unfiltered (gdb_stdlog
,
3555 "KC: kill (SIGKILL) %s, 0, 0 (%s)\n",
3556 target_pid_to_str (lp
->ptid
),
3557 save_errno
? safe_strerror (save_errno
) : "OK");
3560 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3563 ptrace (PTRACE_KILL
, ptid_get_lwp (lp
->ptid
), 0, 0);
3564 if (debug_linux_nat
)
3566 int save_errno
= errno
;
3568 fprintf_unfiltered (gdb_stdlog
,
3569 "KC: PTRACE_KILL %s, 0, 0 (%s)\n",
3570 target_pid_to_str (lp
->ptid
),
3571 save_errno
? safe_strerror (save_errno
) : "OK");
3578 kill_wait_callback (struct lwp_info
*lp
, void *data
)
3582 /* We must make sure that there are no pending events (delayed
3583 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3584 program doesn't interfere with any following debugging session. */
3586 /* For cloned processes we must check both with __WCLONE and
3587 without, since the exit status of a cloned process isn't reported
3593 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), NULL
, __WCLONE
);
3594 if (pid
!= (pid_t
) -1)
3596 if (debug_linux_nat
)
3597 fprintf_unfiltered (gdb_stdlog
,
3598 "KWC: wait %s received unknown.\n",
3599 target_pid_to_str (lp
->ptid
));
3600 /* The Linux kernel sometimes fails to kill a thread
3601 completely after PTRACE_KILL; that goes from the stop
3602 point in do_fork out to the one in
3603 get_signal_to_deliever and waits again. So kill it
3605 kill_callback (lp
, NULL
);
3608 while (pid
== ptid_get_lwp (lp
->ptid
));
3610 gdb_assert (pid
== -1 && errno
== ECHILD
);
3615 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), NULL
, 0);
3616 if (pid
!= (pid_t
) -1)
3618 if (debug_linux_nat
)
3619 fprintf_unfiltered (gdb_stdlog
,
3620 "KWC: wait %s received unk.\n",
3621 target_pid_to_str (lp
->ptid
));
3622 /* See the call to kill_callback above. */
3623 kill_callback (lp
, NULL
);
3626 while (pid
== ptid_get_lwp (lp
->ptid
));
3628 gdb_assert (pid
== -1 && errno
== ECHILD
);
3633 linux_nat_kill (struct target_ops
*ops
)
3635 struct target_waitstatus last
;
3639 /* If we're stopped while forking and we haven't followed yet,
3640 kill the other task. We need to do this first because the
3641 parent will be sleeping if this is a vfork. */
3643 get_last_target_status (&last_ptid
, &last
);
3645 if (last
.kind
== TARGET_WAITKIND_FORKED
3646 || last
.kind
== TARGET_WAITKIND_VFORKED
)
3648 ptrace (PT_KILL
, ptid_get_pid (last
.value
.related_pid
), 0, 0);
3651 /* Let the arch-specific native code know this process is
3653 linux_nat_forget_process (ptid_get_pid (last
.value
.related_pid
));
3656 if (forks_exist_p ())
3657 linux_fork_killall ();
3660 ptid_t ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
3662 /* Stop all threads before killing them, since ptrace requires
3663 that the thread is stopped to sucessfully PTRACE_KILL. */
3664 iterate_over_lwps (ptid
, stop_callback
, NULL
);
3665 /* ... and wait until all of them have reported back that
3666 they're no longer running. */
3667 iterate_over_lwps (ptid
, stop_wait_callback
, NULL
);
3669 /* Kill all LWP's ... */
3670 iterate_over_lwps (ptid
, kill_callback
, NULL
);
3672 /* ... and wait until we've flushed all events. */
3673 iterate_over_lwps (ptid
, kill_wait_callback
, NULL
);
3676 target_mourn_inferior ();
3680 linux_nat_mourn_inferior (struct target_ops
*ops
)
3682 int pid
= ptid_get_pid (inferior_ptid
);
3684 purge_lwp_list (pid
);
3686 if (! forks_exist_p ())
3687 /* Normal case, no other forks available. */
3688 linux_ops
->to_mourn_inferior (ops
);
3690 /* Multi-fork case. The current inferior_ptid has exited, but
3691 there are other viable forks to debug. Delete the exiting
3692 one and context-switch to the first available. */
3693 linux_fork_mourn_inferior ();
3695 /* Let the arch-specific native code know this process is gone. */
3696 linux_nat_forget_process (pid
);
3699 /* Convert a native/host siginfo object, into/from the siginfo in the
3700 layout of the inferiors' architecture. */
3703 siginfo_fixup (siginfo_t
*siginfo
, gdb_byte
*inf_siginfo
, int direction
)
3707 if (linux_nat_siginfo_fixup
!= NULL
)
3708 done
= linux_nat_siginfo_fixup (siginfo
, inf_siginfo
, direction
);
3710 /* If there was no callback, or the callback didn't do anything,
3711 then just do a straight memcpy. */
3715 memcpy (siginfo
, inf_siginfo
, sizeof (siginfo_t
));
3717 memcpy (inf_siginfo
, siginfo
, sizeof (siginfo_t
));
3721 static enum target_xfer_status
3722 linux_xfer_siginfo (struct target_ops
*ops
, enum target_object object
,
3723 const char *annex
, gdb_byte
*readbuf
,
3724 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
3725 ULONGEST
*xfered_len
)
3729 gdb_byte inf_siginfo
[sizeof (siginfo_t
)];
3731 gdb_assert (object
== TARGET_OBJECT_SIGNAL_INFO
);
3732 gdb_assert (readbuf
|| writebuf
);
3734 pid
= ptid_get_lwp (inferior_ptid
);
3736 pid
= ptid_get_pid (inferior_ptid
);
3738 if (offset
> sizeof (siginfo
))
3739 return TARGET_XFER_E_IO
;
3742 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3744 return TARGET_XFER_E_IO
;
3746 /* When GDB is built as a 64-bit application, ptrace writes into
3747 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3748 inferior with a 64-bit GDB should look the same as debugging it
3749 with a 32-bit GDB, we need to convert it. GDB core always sees
3750 the converted layout, so any read/write will have to be done
3752 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
3754 if (offset
+ len
> sizeof (siginfo
))
3755 len
= sizeof (siginfo
) - offset
;
3757 if (readbuf
!= NULL
)
3758 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
3761 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
3763 /* Convert back to ptrace layout before flushing it out. */
3764 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
3767 ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3769 return TARGET_XFER_E_IO
;
3773 return TARGET_XFER_OK
;
3776 static enum target_xfer_status
3777 linux_nat_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3778 const char *annex
, gdb_byte
*readbuf
,
3779 const gdb_byte
*writebuf
,
3780 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
3782 struct cleanup
*old_chain
;
3783 enum target_xfer_status xfer
;
3785 if (object
== TARGET_OBJECT_SIGNAL_INFO
)
3786 return linux_xfer_siginfo (ops
, object
, annex
, readbuf
, writebuf
,
3787 offset
, len
, xfered_len
);
3789 /* The target is connected but no live inferior is selected. Pass
3790 this request down to a lower stratum (e.g., the executable
3792 if (object
== TARGET_OBJECT_MEMORY
&& ptid_equal (inferior_ptid
, null_ptid
))
3793 return TARGET_XFER_EOF
;
3795 old_chain
= save_inferior_ptid ();
3797 if (ptid_lwp_p (inferior_ptid
))
3798 inferior_ptid
= pid_to_ptid (ptid_get_lwp (inferior_ptid
));
3800 xfer
= linux_ops
->to_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
3801 offset
, len
, xfered_len
);
3803 do_cleanups (old_chain
);
3808 linux_thread_alive (ptid_t ptid
)
3812 gdb_assert (ptid_lwp_p (ptid
));
3814 /* Send signal 0 instead of anything ptrace, because ptracing a
3815 running thread errors out claiming that the thread doesn't
3817 err
= kill_lwp (ptid_get_lwp (ptid
), 0);
3819 if (debug_linux_nat
)
3820 fprintf_unfiltered (gdb_stdlog
,
3821 "LLTA: KILL(SIG0) %s (%s)\n",
3822 target_pid_to_str (ptid
),
3823 err
? safe_strerror (tmp_errno
) : "OK");
3832 linux_nat_thread_alive (struct target_ops
*ops
, ptid_t ptid
)
3834 return linux_thread_alive (ptid
);
3838 linux_nat_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
3840 static char buf
[64];
3842 if (ptid_lwp_p (ptid
)
3843 && (ptid_get_pid (ptid
) != ptid_get_lwp (ptid
)
3844 || num_lwps (ptid_get_pid (ptid
)) > 1))
3846 snprintf (buf
, sizeof (buf
), "LWP %ld", ptid_get_lwp (ptid
));
3850 return normal_pid_to_str (ptid
);
3854 linux_nat_thread_name (struct target_ops
*self
, struct thread_info
*thr
)
3856 int pid
= ptid_get_pid (thr
->ptid
);
3857 long lwp
= ptid_get_lwp (thr
->ptid
);
3858 #define FORMAT "/proc/%d/task/%ld/comm"
3859 char buf
[sizeof (FORMAT
) + 30];
3861 char *result
= NULL
;
3863 snprintf (buf
, sizeof (buf
), FORMAT
, pid
, lwp
);
3864 comm_file
= gdb_fopen_cloexec (buf
, "r");
3867 /* Not exported by the kernel, so we define it here. */
3869 static char line
[COMM_LEN
+ 1];
3871 if (fgets (line
, sizeof (line
), comm_file
))
3873 char *nl
= strchr (line
, '\n');
3890 /* Accepts an integer PID; Returns a string representing a file that
3891 can be opened to get the symbols for the child process. */
3894 linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
)
3896 static char buf
[PATH_MAX
];
3897 char name
[PATH_MAX
];
3899 xsnprintf (name
, PATH_MAX
, "/proc/%d/exe", pid
);
3900 memset (buf
, 0, PATH_MAX
);
3901 if (readlink (name
, buf
, PATH_MAX
- 1) <= 0)
3907 /* Implement the to_xfer_partial interface for memory reads using the /proc
3908 filesystem. Because we can use a single read() call for /proc, this
3909 can be much more efficient than banging away at PTRACE_PEEKTEXT,
3910 but it doesn't support writes. */
3912 static enum target_xfer_status
3913 linux_proc_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3914 const char *annex
, gdb_byte
*readbuf
,
3915 const gdb_byte
*writebuf
,
3916 ULONGEST offset
, LONGEST len
, ULONGEST
*xfered_len
)
3922 if (object
!= TARGET_OBJECT_MEMORY
|| !readbuf
)
3925 /* Don't bother for one word. */
3926 if (len
< 3 * sizeof (long))
3927 return TARGET_XFER_EOF
;
3929 /* We could keep this file open and cache it - possibly one per
3930 thread. That requires some juggling, but is even faster. */
3931 xsnprintf (filename
, sizeof filename
, "/proc/%d/mem",
3932 ptid_get_pid (inferior_ptid
));
3933 fd
= gdb_open_cloexec (filename
, O_RDONLY
| O_LARGEFILE
, 0);
3935 return TARGET_XFER_EOF
;
3937 /* If pread64 is available, use it. It's faster if the kernel
3938 supports it (only one syscall), and it's 64-bit safe even on
3939 32-bit platforms (for instance, SPARC debugging a SPARC64
3942 if (pread64 (fd
, readbuf
, len
, offset
) != len
)
3944 if (lseek (fd
, offset
, SEEK_SET
) == -1 || read (fd
, readbuf
, len
) != len
)
3953 return TARGET_XFER_EOF
;
3957 return TARGET_XFER_OK
;
3962 /* Enumerate spufs IDs for process PID. */
3964 spu_enumerate_spu_ids (int pid
, gdb_byte
*buf
, ULONGEST offset
, ULONGEST len
)
3966 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
3968 LONGEST written
= 0;
3971 struct dirent
*entry
;
3973 xsnprintf (path
, sizeof path
, "/proc/%d/fd", pid
);
3974 dir
= opendir (path
);
3979 while ((entry
= readdir (dir
)) != NULL
)
3985 fd
= atoi (entry
->d_name
);
3989 xsnprintf (path
, sizeof path
, "/proc/%d/fd/%d", pid
, fd
);
3990 if (stat (path
, &st
) != 0)
3992 if (!S_ISDIR (st
.st_mode
))
3995 if (statfs (path
, &stfs
) != 0)
3997 if (stfs
.f_type
!= SPUFS_MAGIC
)
4000 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4002 store_unsigned_integer (buf
+ pos
- offset
, 4, byte_order
, fd
);
4012 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4013 object type, using the /proc file system. */
4015 static enum target_xfer_status
4016 linux_proc_xfer_spu (struct target_ops
*ops
, enum target_object object
,
4017 const char *annex
, gdb_byte
*readbuf
,
4018 const gdb_byte
*writebuf
,
4019 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
4024 int pid
= ptid_get_pid (inferior_ptid
);
4029 return TARGET_XFER_E_IO
;
4032 LONGEST l
= spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4035 return TARGET_XFER_E_IO
;
4037 return TARGET_XFER_EOF
;
4040 *xfered_len
= (ULONGEST
) l
;
4041 return TARGET_XFER_OK
;
4046 xsnprintf (buf
, sizeof buf
, "/proc/%d/fd/%s", pid
, annex
);
4047 fd
= gdb_open_cloexec (buf
, writebuf
? O_WRONLY
: O_RDONLY
, 0);
4049 return TARGET_XFER_E_IO
;
4052 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4055 return TARGET_XFER_EOF
;
4059 ret
= write (fd
, writebuf
, (size_t) len
);
4061 ret
= read (fd
, readbuf
, (size_t) len
);
4066 return TARGET_XFER_E_IO
;
4068 return TARGET_XFER_EOF
;
4071 *xfered_len
= (ULONGEST
) ret
;
4072 return TARGET_XFER_OK
;
4077 /* Parse LINE as a signal set and add its set bits to SIGS. */
4080 add_line_to_sigset (const char *line
, sigset_t
*sigs
)
4082 int len
= strlen (line
) - 1;
4086 if (line
[len
] != '\n')
4087 error (_("Could not parse signal set: %s"), line
);
4095 if (*p
>= '0' && *p
<= '9')
4097 else if (*p
>= 'a' && *p
<= 'f')
4098 digit
= *p
- 'a' + 10;
4100 error (_("Could not parse signal set: %s"), line
);
4105 sigaddset (sigs
, signum
+ 1);
4107 sigaddset (sigs
, signum
+ 2);
4109 sigaddset (sigs
, signum
+ 3);
4111 sigaddset (sigs
, signum
+ 4);
4117 /* Find process PID's pending signals from /proc/pid/status and set
4121 linux_proc_pending_signals (int pid
, sigset_t
*pending
,
4122 sigset_t
*blocked
, sigset_t
*ignored
)
4125 char buffer
[PATH_MAX
], fname
[PATH_MAX
];
4126 struct cleanup
*cleanup
;
4128 sigemptyset (pending
);
4129 sigemptyset (blocked
);
4130 sigemptyset (ignored
);
4131 xsnprintf (fname
, sizeof fname
, "/proc/%d/status", pid
);
4132 procfile
= gdb_fopen_cloexec (fname
, "r");
4133 if (procfile
== NULL
)
4134 error (_("Could not open %s"), fname
);
4135 cleanup
= make_cleanup_fclose (procfile
);
4137 while (fgets (buffer
, PATH_MAX
, procfile
) != NULL
)
4139 /* Normal queued signals are on the SigPnd line in the status
4140 file. However, 2.6 kernels also have a "shared" pending
4141 queue for delivering signals to a thread group, so check for
4144 Unfortunately some Red Hat kernels include the shared pending
4145 queue but not the ShdPnd status field. */
4147 if (strncmp (buffer
, "SigPnd:\t", 8) == 0)
4148 add_line_to_sigset (buffer
+ 8, pending
);
4149 else if (strncmp (buffer
, "ShdPnd:\t", 8) == 0)
4150 add_line_to_sigset (buffer
+ 8, pending
);
4151 else if (strncmp (buffer
, "SigBlk:\t", 8) == 0)
4152 add_line_to_sigset (buffer
+ 8, blocked
);
4153 else if (strncmp (buffer
, "SigIgn:\t", 8) == 0)
4154 add_line_to_sigset (buffer
+ 8, ignored
);
4157 do_cleanups (cleanup
);
4160 static enum target_xfer_status
4161 linux_nat_xfer_osdata (struct target_ops
*ops
, enum target_object object
,
4162 const char *annex
, gdb_byte
*readbuf
,
4163 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4164 ULONGEST
*xfered_len
)
4166 gdb_assert (object
== TARGET_OBJECT_OSDATA
);
4168 *xfered_len
= linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
4169 if (*xfered_len
== 0)
4170 return TARGET_XFER_EOF
;
4172 return TARGET_XFER_OK
;
4175 static enum target_xfer_status
4176 linux_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4177 const char *annex
, gdb_byte
*readbuf
,
4178 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4179 ULONGEST
*xfered_len
)
4181 enum target_xfer_status xfer
;
4183 if (object
== TARGET_OBJECT_AUXV
)
4184 return memory_xfer_auxv (ops
, object
, annex
, readbuf
, writebuf
,
4185 offset
, len
, xfered_len
);
4187 if (object
== TARGET_OBJECT_OSDATA
)
4188 return linux_nat_xfer_osdata (ops
, object
, annex
, readbuf
, writebuf
,
4189 offset
, len
, xfered_len
);
4191 if (object
== TARGET_OBJECT_SPU
)
4192 return linux_proc_xfer_spu (ops
, object
, annex
, readbuf
, writebuf
,
4193 offset
, len
, xfered_len
);
4195 /* GDB calculates all the addresses in possibly larget width of the address.
4196 Address width needs to be masked before its final use - either by
4197 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4199 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4201 if (object
== TARGET_OBJECT_MEMORY
)
4203 int addr_bit
= gdbarch_addr_bit (target_gdbarch ());
4205 if (addr_bit
< (sizeof (ULONGEST
) * HOST_CHAR_BIT
))
4206 offset
&= ((ULONGEST
) 1 << addr_bit
) - 1;
4209 xfer
= linux_proc_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4210 offset
, len
, xfered_len
);
4211 if (xfer
!= TARGET_XFER_EOF
)
4214 return super_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4215 offset
, len
, xfered_len
);
4219 cleanup_target_stop (void *arg
)
4221 ptid_t
*ptid
= (ptid_t
*) arg
;
4223 gdb_assert (arg
!= NULL
);
4226 target_resume (*ptid
, 0, GDB_SIGNAL_0
);
4229 static VEC(static_tracepoint_marker_p
) *
4230 linux_child_static_tracepoint_markers_by_strid (struct target_ops
*self
,
4233 char s
[IPA_CMD_BUF_SIZE
];
4234 struct cleanup
*old_chain
;
4235 int pid
= ptid_get_pid (inferior_ptid
);
4236 VEC(static_tracepoint_marker_p
) *markers
= NULL
;
4237 struct static_tracepoint_marker
*marker
= NULL
;
4239 ptid_t ptid
= ptid_build (pid
, 0, 0);
4244 memcpy (s
, "qTfSTM", sizeof ("qTfSTM"));
4245 s
[sizeof ("qTfSTM")] = 0;
4247 agent_run_command (pid
, s
, strlen (s
) + 1);
4249 old_chain
= make_cleanup (free_current_marker
, &marker
);
4250 make_cleanup (cleanup_target_stop
, &ptid
);
4255 marker
= XCNEW (struct static_tracepoint_marker
);
4259 parse_static_tracepoint_marker_definition (p
, &p
, marker
);
4261 if (strid
== NULL
|| strcmp (strid
, marker
->str_id
) == 0)
4263 VEC_safe_push (static_tracepoint_marker_p
,
4269 release_static_tracepoint_marker (marker
);
4270 memset (marker
, 0, sizeof (*marker
));
4273 while (*p
++ == ','); /* comma-separated list */
4275 memcpy (s
, "qTsSTM", sizeof ("qTsSTM"));
4276 s
[sizeof ("qTsSTM")] = 0;
4277 agent_run_command (pid
, s
, strlen (s
) + 1);
4281 do_cleanups (old_chain
);
4286 /* Create a prototype generic GNU/Linux target. The client can override
4287 it with local methods. */
4290 linux_target_install_ops (struct target_ops
*t
)
4292 t
->to_insert_fork_catchpoint
= linux_child_insert_fork_catchpoint
;
4293 t
->to_remove_fork_catchpoint
= linux_child_remove_fork_catchpoint
;
4294 t
->to_insert_vfork_catchpoint
= linux_child_insert_vfork_catchpoint
;
4295 t
->to_remove_vfork_catchpoint
= linux_child_remove_vfork_catchpoint
;
4296 t
->to_insert_exec_catchpoint
= linux_child_insert_exec_catchpoint
;
4297 t
->to_remove_exec_catchpoint
= linux_child_remove_exec_catchpoint
;
4298 t
->to_set_syscall_catchpoint
= linux_child_set_syscall_catchpoint
;
4299 t
->to_pid_to_exec_file
= linux_child_pid_to_exec_file
;
4300 t
->to_post_startup_inferior
= linux_child_post_startup_inferior
;
4301 t
->to_post_attach
= linux_child_post_attach
;
4302 t
->to_follow_fork
= linux_child_follow_fork
;
4304 super_xfer_partial
= t
->to_xfer_partial
;
4305 t
->to_xfer_partial
= linux_xfer_partial
;
4307 t
->to_static_tracepoint_markers_by_strid
4308 = linux_child_static_tracepoint_markers_by_strid
;
4314 struct target_ops
*t
;
4316 t
= inf_ptrace_target ();
4317 linux_target_install_ops (t
);
4323 linux_trad_target (CORE_ADDR (*register_u_offset
)(struct gdbarch
*, int, int))
4325 struct target_ops
*t
;
4327 t
= inf_ptrace_trad_target (register_u_offset
);
4328 linux_target_install_ops (t
);
4333 /* target_is_async_p implementation. */
4336 linux_nat_is_async_p (struct target_ops
*ops
)
4338 /* NOTE: palves 2008-03-21: We're only async when the user requests
4339 it explicitly with the "set target-async" command.
4340 Someday, linux will always be async. */
4341 return target_async_permitted
;
4344 /* target_can_async_p implementation. */
4347 linux_nat_can_async_p (struct target_ops
*ops
)
4349 /* NOTE: palves 2008-03-21: We're only async when the user requests
4350 it explicitly with the "set target-async" command.
4351 Someday, linux will always be async. */
4352 return target_async_permitted
;
4356 linux_nat_supports_non_stop (struct target_ops
*self
)
4361 /* True if we want to support multi-process. To be removed when GDB
4362 supports multi-exec. */
4364 int linux_multi_process
= 1;
4367 linux_nat_supports_multi_process (struct target_ops
*self
)
4369 return linux_multi_process
;
4373 linux_nat_supports_disable_randomization (struct target_ops
*self
)
4375 #ifdef HAVE_PERSONALITY
4382 static int async_terminal_is_ours
= 1;
4384 /* target_terminal_inferior implementation.
4386 This is a wrapper around child_terminal_inferior to add async support. */
4389 linux_nat_terminal_inferior (struct target_ops
*self
)
4391 if (!target_is_async_p ())
4393 /* Async mode is disabled. */
4394 child_terminal_inferior (self
);
4398 child_terminal_inferior (self
);
4400 /* Calls to target_terminal_*() are meant to be idempotent. */
4401 if (!async_terminal_is_ours
)
4404 delete_file_handler (input_fd
);
4405 async_terminal_is_ours
= 0;
4409 /* target_terminal_ours implementation.
4411 This is a wrapper around child_terminal_ours to add async support (and
4412 implement the target_terminal_ours vs target_terminal_ours_for_output
4413 distinction). child_terminal_ours is currently no different than
4414 child_terminal_ours_for_output.
4415 We leave target_terminal_ours_for_output alone, leaving it to
4416 child_terminal_ours_for_output. */
4419 linux_nat_terminal_ours (struct target_ops
*self
)
4421 if (!target_is_async_p ())
4423 /* Async mode is disabled. */
4424 child_terminal_ours (self
);
4428 /* GDB should never give the terminal to the inferior if the
4429 inferior is running in the background (run&, continue&, etc.),
4430 but claiming it sure should. */
4431 child_terminal_ours (self
);
4433 if (async_terminal_is_ours
)
4436 clear_sigint_trap ();
4437 add_file_handler (input_fd
, stdin_event_handler
, 0);
4438 async_terminal_is_ours
= 1;
4441 static void (*async_client_callback
) (enum inferior_event_type event_type
,
4443 static void *async_client_context
;
4445 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4446 so we notice when any child changes state, and notify the
4447 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4448 above to wait for the arrival of a SIGCHLD. */
4451 sigchld_handler (int signo
)
4453 int old_errno
= errno
;
4455 if (debug_linux_nat
)
4456 ui_file_write_async_safe (gdb_stdlog
,
4457 "sigchld\n", sizeof ("sigchld\n") - 1);
4459 if (signo
== SIGCHLD
4460 && linux_nat_event_pipe
[0] != -1)
4461 async_file_mark (); /* Let the event loop know that there are
4462 events to handle. */
4467 /* Callback registered with the target events file descriptor. */
4470 handle_target_event (int error
, gdb_client_data client_data
)
4472 (*async_client_callback
) (INF_REG_EVENT
, async_client_context
);
4475 /* Create/destroy the target events pipe. Returns previous state. */
4478 linux_async_pipe (int enable
)
4480 int previous
= (linux_nat_event_pipe
[0] != -1);
4482 if (previous
!= enable
)
4486 /* Block child signals while we create/destroy the pipe, as
4487 their handler writes to it. */
4488 block_child_signals (&prev_mask
);
4492 if (gdb_pipe_cloexec (linux_nat_event_pipe
) == -1)
4493 internal_error (__FILE__
, __LINE__
,
4494 "creating event pipe failed.");
4496 fcntl (linux_nat_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4497 fcntl (linux_nat_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4501 close (linux_nat_event_pipe
[0]);
4502 close (linux_nat_event_pipe
[1]);
4503 linux_nat_event_pipe
[0] = -1;
4504 linux_nat_event_pipe
[1] = -1;
4507 restore_child_signals_mask (&prev_mask
);
4513 /* target_async implementation. */
4516 linux_nat_async (struct target_ops
*ops
,
4517 void (*callback
) (enum inferior_event_type event_type
,
4521 if (callback
!= NULL
)
4523 async_client_callback
= callback
;
4524 async_client_context
= context
;
4525 if (!linux_async_pipe (1))
4527 add_file_handler (linux_nat_event_pipe
[0],
4528 handle_target_event
, NULL
);
4529 /* There may be pending events to handle. Tell the event loop
4536 async_client_callback
= callback
;
4537 async_client_context
= context
;
4538 delete_file_handler (linux_nat_event_pipe
[0]);
4539 linux_async_pipe (0);
4544 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4548 linux_nat_stop_lwp (struct lwp_info
*lwp
, void *data
)
4552 if (debug_linux_nat
)
4553 fprintf_unfiltered (gdb_stdlog
,
4554 "LNSL: running -> suspending %s\n",
4555 target_pid_to_str (lwp
->ptid
));
4558 if (lwp
->last_resume_kind
== resume_stop
)
4560 if (debug_linux_nat
)
4561 fprintf_unfiltered (gdb_stdlog
,
4562 "linux-nat: already stopping LWP %ld at "
4564 ptid_get_lwp (lwp
->ptid
));
4568 stop_callback (lwp
, NULL
);
4569 lwp
->last_resume_kind
= resume_stop
;
4573 /* Already known to be stopped; do nothing. */
4575 if (debug_linux_nat
)
4577 if (find_thread_ptid (lwp
->ptid
)->stop_requested
)
4578 fprintf_unfiltered (gdb_stdlog
,
4579 "LNSL: already stopped/stop_requested %s\n",
4580 target_pid_to_str (lwp
->ptid
));
4582 fprintf_unfiltered (gdb_stdlog
,
4583 "LNSL: already stopped/no "
4584 "stop_requested yet %s\n",
4585 target_pid_to_str (lwp
->ptid
));
4592 linux_nat_stop (struct target_ops
*self
, ptid_t ptid
)
4595 iterate_over_lwps (ptid
, linux_nat_stop_lwp
, NULL
);
4597 linux_ops
->to_stop (linux_ops
, ptid
);
4601 linux_nat_close (struct target_ops
*self
)
4603 /* Unregister from the event loop. */
4604 if (linux_nat_is_async_p (self
))
4605 linux_nat_async (self
, NULL
, NULL
);
4607 if (linux_ops
->to_close
)
4608 linux_ops
->to_close (linux_ops
);
4613 /* When requests are passed down from the linux-nat layer to the
4614 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4615 used. The address space pointer is stored in the inferior object,
4616 but the common code that is passed such ptid can't tell whether
4617 lwpid is a "main" process id or not (it assumes so). We reverse
4618 look up the "main" process id from the lwp here. */
4620 static struct address_space
*
4621 linux_nat_thread_address_space (struct target_ops
*t
, ptid_t ptid
)
4623 struct lwp_info
*lwp
;
4624 struct inferior
*inf
;
4627 if (ptid_get_lwp (ptid
) == 0)
4629 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4631 lwp
= find_lwp_pid (ptid
);
4632 pid
= ptid_get_pid (lwp
->ptid
);
4636 /* A (pid,lwpid,0) ptid. */
4637 pid
= ptid_get_pid (ptid
);
4640 inf
= find_inferior_pid (pid
);
4641 gdb_assert (inf
!= NULL
);
4645 /* Return the cached value of the processor core for thread PTID. */
4648 linux_nat_core_of_thread (struct target_ops
*ops
, ptid_t ptid
)
4650 struct lwp_info
*info
= find_lwp_pid (ptid
);
4658 linux_nat_add_target (struct target_ops
*t
)
4660 /* Save the provided single-threaded target. We save this in a separate
4661 variable because another target we've inherited from (e.g. inf-ptrace)
4662 may have saved a pointer to T; we want to use it for the final
4663 process stratum target. */
4664 linux_ops_saved
= *t
;
4665 linux_ops
= &linux_ops_saved
;
4667 /* Override some methods for multithreading. */
4668 t
->to_create_inferior
= linux_nat_create_inferior
;
4669 t
->to_attach
= linux_nat_attach
;
4670 t
->to_detach
= linux_nat_detach
;
4671 t
->to_resume
= linux_nat_resume
;
4672 t
->to_wait
= linux_nat_wait
;
4673 t
->to_pass_signals
= linux_nat_pass_signals
;
4674 t
->to_xfer_partial
= linux_nat_xfer_partial
;
4675 t
->to_kill
= linux_nat_kill
;
4676 t
->to_mourn_inferior
= linux_nat_mourn_inferior
;
4677 t
->to_thread_alive
= linux_nat_thread_alive
;
4678 t
->to_pid_to_str
= linux_nat_pid_to_str
;
4679 t
->to_thread_name
= linux_nat_thread_name
;
4680 t
->to_has_thread_control
= tc_schedlock
;
4681 t
->to_thread_address_space
= linux_nat_thread_address_space
;
4682 t
->to_stopped_by_watchpoint
= linux_nat_stopped_by_watchpoint
;
4683 t
->to_stopped_data_address
= linux_nat_stopped_data_address
;
4685 t
->to_can_async_p
= linux_nat_can_async_p
;
4686 t
->to_is_async_p
= linux_nat_is_async_p
;
4687 t
->to_supports_non_stop
= linux_nat_supports_non_stop
;
4688 t
->to_async
= linux_nat_async
;
4689 t
->to_terminal_inferior
= linux_nat_terminal_inferior
;
4690 t
->to_terminal_ours
= linux_nat_terminal_ours
;
4692 super_close
= t
->to_close
;
4693 t
->to_close
= linux_nat_close
;
4695 /* Methods for non-stop support. */
4696 t
->to_stop
= linux_nat_stop
;
4698 t
->to_supports_multi_process
= linux_nat_supports_multi_process
;
4700 t
->to_supports_disable_randomization
4701 = linux_nat_supports_disable_randomization
;
4703 t
->to_core_of_thread
= linux_nat_core_of_thread
;
4705 /* We don't change the stratum; this target will sit at
4706 process_stratum and thread_db will set at thread_stratum. This
4707 is a little strange, since this is a multi-threaded-capable
4708 target, but we want to be on the stack below thread_db, and we
4709 also want to be used for single-threaded processes. */
4714 /* Register a method to call whenever a new thread is attached. */
4716 linux_nat_set_new_thread (struct target_ops
*t
,
4717 void (*new_thread
) (struct lwp_info
*))
4719 /* Save the pointer. We only support a single registered instance
4720 of the GNU/Linux native target, so we do not need to map this to
4722 linux_nat_new_thread
= new_thread
;
4725 /* See declaration in linux-nat.h. */
4728 linux_nat_set_new_fork (struct target_ops
*t
,
4729 linux_nat_new_fork_ftype
*new_fork
)
4731 /* Save the pointer. */
4732 linux_nat_new_fork
= new_fork
;
4735 /* See declaration in linux-nat.h. */
4738 linux_nat_set_forget_process (struct target_ops
*t
,
4739 linux_nat_forget_process_ftype
*fn
)
4741 /* Save the pointer. */
4742 linux_nat_forget_process_hook
= fn
;
4745 /* See declaration in linux-nat.h. */
4748 linux_nat_forget_process (pid_t pid
)
4750 if (linux_nat_forget_process_hook
!= NULL
)
4751 linux_nat_forget_process_hook (pid
);
4754 /* Register a method that converts a siginfo object between the layout
4755 that ptrace returns, and the layout in the architecture of the
4758 linux_nat_set_siginfo_fixup (struct target_ops
*t
,
4759 int (*siginfo_fixup
) (siginfo_t
*,
4763 /* Save the pointer. */
4764 linux_nat_siginfo_fixup
= siginfo_fixup
;
4767 /* Register a method to call prior to resuming a thread. */
4770 linux_nat_set_prepare_to_resume (struct target_ops
*t
,
4771 void (*prepare_to_resume
) (struct lwp_info
*))
4773 /* Save the pointer. */
4774 linux_nat_prepare_to_resume
= prepare_to_resume
;
4777 /* See linux-nat.h. */
4780 linux_nat_get_siginfo (ptid_t ptid
, siginfo_t
*siginfo
)
4784 pid
= ptid_get_lwp (ptid
);
4786 pid
= ptid_get_pid (ptid
);
4789 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, siginfo
);
4792 memset (siginfo
, 0, sizeof (*siginfo
));
4798 /* Provide a prototype to silence -Wmissing-prototypes. */
4799 extern initialize_file_ftype _initialize_linux_nat
;
4802 _initialize_linux_nat (void)
4804 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance
,
4805 &debug_linux_nat
, _("\
4806 Set debugging of GNU/Linux lwp module."), _("\
4807 Show debugging of GNU/Linux lwp module."), _("\
4808 Enables printf debugging output."),
4810 show_debug_linux_nat
,
4811 &setdebuglist
, &showdebuglist
);
4813 /* Save this mask as the default. */
4814 sigprocmask (SIG_SETMASK
, NULL
, &normal_mask
);
4816 /* Install a SIGCHLD handler. */
4817 sigchld_action
.sa_handler
= sigchld_handler
;
4818 sigemptyset (&sigchld_action
.sa_mask
);
4819 sigchld_action
.sa_flags
= SA_RESTART
;
4821 /* Make it the default. */
4822 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
4824 /* Make sure we don't block SIGCHLD during a sigsuspend. */
4825 sigprocmask (SIG_SETMASK
, NULL
, &suspend_mask
);
4826 sigdelset (&suspend_mask
, SIGCHLD
);
4828 sigemptyset (&blocked_mask
);
4830 /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to
4831 support read-only process state. */
4832 linux_ptrace_set_additional_flags (PTRACE_O_TRACESYSGOOD
4833 | PTRACE_O_TRACEVFORKDONE
4834 | PTRACE_O_TRACEVFORK
4835 | PTRACE_O_TRACEFORK
4836 | PTRACE_O_TRACEEXEC
);
4840 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
4841 the GNU/Linux Threads library and therefore doesn't really belong
4844 /* Read variable NAME in the target and return its value if found.
4845 Otherwise return zero. It is assumed that the type of the variable
4849 get_signo (const char *name
)
4851 struct bound_minimal_symbol ms
;
4854 ms
= lookup_minimal_symbol (name
, NULL
, NULL
);
4855 if (ms
.minsym
== NULL
)
4858 if (target_read_memory (BMSYMBOL_VALUE_ADDRESS (ms
), (gdb_byte
*) &signo
,
4859 sizeof (signo
)) != 0)
4865 /* Return the set of signals used by the threads library in *SET. */
4868 lin_thread_get_thread_signals (sigset_t
*set
)
4870 struct sigaction action
;
4871 int restart
, cancel
;
4873 sigemptyset (&blocked_mask
);
4876 restart
= get_signo ("__pthread_sig_restart");
4877 cancel
= get_signo ("__pthread_sig_cancel");
4879 /* LinuxThreads normally uses the first two RT signals, but in some legacy
4880 cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
4881 not provide any way for the debugger to query the signal numbers -
4882 fortunately they don't change! */
4885 restart
= __SIGRTMIN
;
4888 cancel
= __SIGRTMIN
+ 1;
4890 sigaddset (set
, restart
);
4891 sigaddset (set
, cancel
);
4893 /* The GNU/Linux Threads library makes terminating threads send a
4894 special "cancel" signal instead of SIGCHLD. Make sure we catch
4895 those (to prevent them from terminating GDB itself, which is
4896 likely to be their default action) and treat them the same way as
4899 action
.sa_handler
= sigchld_handler
;
4900 sigemptyset (&action
.sa_mask
);
4901 action
.sa_flags
= SA_RESTART
;
4902 sigaction (cancel
, &action
, NULL
);
4904 /* We block the "cancel" signal throughout this code ... */
4905 sigaddset (&blocked_mask
, cancel
);
4906 sigprocmask (SIG_BLOCK
, &blocked_mask
, NULL
);
4908 /* ... except during a sigsuspend. */
4909 sigdelset (&suspend_mask
, cancel
);