1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001-2014 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/>. */
23 #include "nat/linux-nat.h"
24 #include "nat/linux-waitpid.h"
27 #include "gdb_assert.h"
28 #ifdef HAVE_TKILL_SYSCALL
30 #include <sys/syscall.h>
32 #include <sys/ptrace.h>
33 #include "linux-nat.h"
34 #include "linux-ptrace.h"
35 #include "linux-procfs.h"
36 #include "linux-fork.h"
37 #include "gdbthread.h"
41 #include "inf-child.h"
42 #include "inf-ptrace.h"
44 #include <sys/procfs.h> /* for elf_gregset etc. */
45 #include "elf-bfd.h" /* for elfcore_write_* */
46 #include "gregset.h" /* for gregset */
47 #include "gdbcore.h" /* for get_exec_file */
48 #include <ctype.h> /* for isdigit */
49 #include <sys/stat.h> /* for struct stat */
50 #include <fcntl.h> /* for O_RDONLY */
52 #include "event-loop.h"
53 #include "event-top.h"
55 #include <sys/types.h>
57 #include "xml-support.h"
61 #include "linux-osdata.h"
62 #include "linux-tdep.h"
65 #include "tracepoint.h"
66 #include "exceptions.h"
68 #include "target-descriptions.h"
69 #include "filestuff.h"
73 #define SPUFS_MAGIC 0x23c9b64e
76 #ifdef HAVE_PERSONALITY
77 # include <sys/personality.h>
78 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
79 # define ADDR_NO_RANDOMIZE 0x0040000
81 #endif /* HAVE_PERSONALITY */
83 /* This comment documents high-level logic of this file.
85 Waiting for events in sync mode
86 ===============================
88 When waiting for an event in a specific thread, we just use waitpid, passing
89 the specific pid, and not passing WNOHANG.
91 When waiting for an event in all threads, waitpid is not quite good. Prior to
92 version 2.4, Linux can either wait for event in main thread, or in secondary
93 threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might
94 miss an event. The solution is to use non-blocking waitpid, together with
95 sigsuspend. First, we use non-blocking waitpid to get an event in the main
96 process, if any. Second, we use non-blocking waitpid with the __WCLONED
97 flag to check for events in cloned processes. If nothing is found, we use
98 sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something
99 happened to a child process -- and SIGCHLD will be delivered both for events
100 in main debugged process and in cloned processes. As soon as we know there's
101 an event, we get back to calling nonblocking waitpid with and without
104 Note that SIGCHLD should be blocked between waitpid and sigsuspend calls,
105 so that we don't miss a signal. If SIGCHLD arrives in between, when it's
106 blocked, the signal becomes pending and sigsuspend immediately
107 notices it and returns.
109 Waiting for events in async mode
110 ================================
112 In async mode, GDB should always be ready to handle both user input
113 and target events, so neither blocking waitpid nor sigsuspend are
114 viable options. Instead, we should asynchronously notify the GDB main
115 event loop whenever there's an unprocessed event from the target. We
116 detect asynchronous target events by handling SIGCHLD signals. To
117 notify the event loop about target events, the self-pipe trick is used
118 --- a pipe is registered as waitable event source in the event loop,
119 the event loop select/poll's on the read end of this pipe (as well on
120 other event sources, e.g., stdin), and the SIGCHLD handler writes a
121 byte to this pipe. This is more portable than relying on
122 pselect/ppoll, since on kernels that lack those syscalls, libc
123 emulates them with select/poll+sigprocmask, and that is racy
124 (a.k.a. plain broken).
126 Obviously, if we fail to notify the event loop if there's a target
127 event, it's bad. OTOH, if we notify the event loop when there's no
128 event from the target, linux_nat_wait will detect that there's no real
129 event to report, and return event of type TARGET_WAITKIND_IGNORE.
130 This is mostly harmless, but it will waste time and is better avoided.
132 The main design point is that every time GDB is outside linux-nat.c,
133 we have a SIGCHLD handler installed that is called when something
134 happens to the target and notifies the GDB event loop. Whenever GDB
135 core decides to handle the event, and calls into linux-nat.c, we
136 process things as in sync mode, except that the we never block in
139 While processing an event, we may end up momentarily blocked in
140 waitpid calls. Those waitpid calls, while blocking, are guarantied to
141 return quickly. E.g., in all-stop mode, before reporting to the core
142 that an LWP hit a breakpoint, all LWPs are stopped by sending them
143 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
144 Note that this is different from blocking indefinitely waiting for the
145 next event --- here, we're already handling an event.
150 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
151 signal is not entirely significant; we just need for a signal to be delivered,
152 so that we can intercept it. SIGSTOP's advantage is that it can not be
153 blocked. A disadvantage is that it is not a real-time signal, so it can only
154 be queued once; we do not keep track of other sources of SIGSTOP.
156 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
157 use them, because they have special behavior when the signal is generated -
158 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
159 kills the entire thread group.
161 A delivered SIGSTOP would stop the entire thread group, not just the thread we
162 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
163 cancel it (by PTRACE_CONT without passing SIGSTOP).
165 We could use a real-time signal instead. This would solve those problems; we
166 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
167 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
168 generates it, and there are races with trying to find a signal that is not
172 #define O_LARGEFILE 0
175 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
176 the use of the multi-threaded target. */
177 static struct target_ops
*linux_ops
;
178 static struct target_ops linux_ops_saved
;
180 /* The method to call, if any, when a new thread is attached. */
181 static void (*linux_nat_new_thread
) (struct lwp_info
*);
183 /* The method to call, if any, when a new fork is attached. */
184 static linux_nat_new_fork_ftype
*linux_nat_new_fork
;
186 /* The method to call, if any, when a process is no longer
188 static linux_nat_forget_process_ftype
*linux_nat_forget_process_hook
;
190 /* Hook to call prior to resuming a thread. */
191 static void (*linux_nat_prepare_to_resume
) (struct lwp_info
*);
193 /* The method to call, if any, when the siginfo object needs to be
194 converted between the layout returned by ptrace, and the layout in
195 the architecture of the inferior. */
196 static int (*linux_nat_siginfo_fixup
) (siginfo_t
*,
200 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
201 Called by our to_xfer_partial. */
202 static target_xfer_partial_ftype
*super_xfer_partial
;
204 static unsigned int debug_linux_nat
;
206 show_debug_linux_nat (struct ui_file
*file
, int from_tty
,
207 struct cmd_list_element
*c
, const char *value
)
209 fprintf_filtered (file
, _("Debugging of GNU/Linux lwp module is %s.\n"),
213 struct simple_pid_list
217 struct simple_pid_list
*next
;
219 struct simple_pid_list
*stopped_pids
;
221 /* Async mode support. */
223 /* The read/write ends of the pipe registered as waitable file in the
225 static int linux_nat_event_pipe
[2] = { -1, -1 };
227 /* Flush the event pipe. */
230 async_file_flush (void)
237 ret
= read (linux_nat_event_pipe
[0], &buf
, 1);
239 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
242 /* Put something (anything, doesn't matter what, or how much) in event
243 pipe, so that the select/poll in the event-loop realizes we have
244 something to process. */
247 async_file_mark (void)
251 /* It doesn't really matter what the pipe contains, as long we end
252 up with something in it. Might as well flush the previous
258 ret
= write (linux_nat_event_pipe
[1], "+", 1);
260 while (ret
== -1 && errno
== EINTR
);
262 /* Ignore EAGAIN. If the pipe is full, the event loop will already
263 be awakened anyway. */
266 static int kill_lwp (int lwpid
, int signo
);
268 static int stop_callback (struct lwp_info
*lp
, void *data
);
270 static void block_child_signals (sigset_t
*prev_mask
);
271 static void restore_child_signals_mask (sigset_t
*prev_mask
);
274 static struct lwp_info
*add_lwp (ptid_t ptid
);
275 static void purge_lwp_list (int pid
);
276 static void delete_lwp (ptid_t ptid
);
277 static struct lwp_info
*find_lwp_pid (ptid_t ptid
);
280 /* Trivial list manipulation functions to keep track of a list of
281 new stopped processes. */
283 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
285 struct simple_pid_list
*new_pid
= xmalloc (sizeof (struct simple_pid_list
));
288 new_pid
->status
= status
;
289 new_pid
->next
= *listp
;
294 in_pid_list_p (struct simple_pid_list
*list
, int pid
)
296 struct simple_pid_list
*p
;
298 for (p
= list
; p
!= NULL
; p
= p
->next
)
305 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *statusp
)
307 struct simple_pid_list
**p
;
309 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
310 if ((*p
)->pid
== pid
)
312 struct simple_pid_list
*next
= (*p
)->next
;
314 *statusp
= (*p
)->status
;
322 /* Initialize ptrace warnings and check for supported ptrace
323 features given PID. */
326 linux_init_ptrace (pid_t pid
)
328 linux_enable_event_reporting (pid
);
329 linux_ptrace_init_warnings ();
333 linux_child_post_attach (struct target_ops
*self
, int pid
)
335 linux_init_ptrace (pid
);
339 linux_child_post_startup_inferior (struct target_ops
*self
, ptid_t ptid
)
341 linux_init_ptrace (ptid_get_pid (ptid
));
344 /* Return the number of known LWPs in the tgid given by PID. */
352 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
353 if (ptid_get_pid (lp
->ptid
) == pid
)
359 /* Call delete_lwp with prototype compatible for make_cleanup. */
362 delete_lwp_cleanup (void *lp_voidp
)
364 struct lwp_info
*lp
= lp_voidp
;
366 delete_lwp (lp
->ptid
);
370 linux_child_follow_fork (struct target_ops
*ops
, int follow_child
,
374 int parent_pid
, child_pid
;
376 has_vforked
= (inferior_thread ()->pending_follow
.kind
377 == TARGET_WAITKIND_VFORKED
);
378 parent_pid
= ptid_get_lwp (inferior_ptid
);
380 parent_pid
= ptid_get_pid (inferior_ptid
);
382 = ptid_get_pid (inferior_thread ()->pending_follow
.value
.related_pid
);
385 && !non_stop
/* Non-stop always resumes both branches. */
386 && (!target_is_async_p () || sync_execution
)
387 && !(follow_child
|| detach_fork
|| sched_multi
))
389 /* The parent stays blocked inside the vfork syscall until the
390 child execs or exits. If we don't let the child run, then
391 the parent stays blocked. If we're telling the parent to run
392 in the foreground, the user will not be able to ctrl-c to get
393 back the terminal, effectively hanging the debug session. */
394 fprintf_filtered (gdb_stderr
, _("\
395 Can not resume the parent process over vfork in the foreground while\n\
396 holding the child stopped. Try \"set detach-on-fork\" or \
397 \"set schedule-multiple\".\n"));
398 /* FIXME output string > 80 columns. */
404 struct lwp_info
*child_lp
= NULL
;
406 /* We're already attached to the parent, by default. */
408 /* Detach new forked process? */
411 struct cleanup
*old_chain
;
413 /* Before detaching from the child, remove all breakpoints
414 from it. If we forked, then this has already been taken
415 care of by infrun.c. If we vforked however, any
416 breakpoint inserted in the parent is visible in the
417 child, even those added while stopped in a vfork
418 catchpoint. This will remove the breakpoints from the
419 parent also, but they'll be reinserted below. */
422 /* keep breakpoints list in sync. */
423 remove_breakpoints_pid (ptid_get_pid (inferior_ptid
));
426 if (info_verbose
|| debug_linux_nat
)
428 target_terminal_ours ();
429 fprintf_filtered (gdb_stdlog
,
430 "Detaching after fork from "
431 "child process %d.\n",
435 old_chain
= save_inferior_ptid ();
436 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
438 child_lp
= add_lwp (inferior_ptid
);
439 child_lp
->stopped
= 1;
440 child_lp
->last_resume_kind
= resume_stop
;
441 make_cleanup (delete_lwp_cleanup
, child_lp
);
443 if (linux_nat_prepare_to_resume
!= NULL
)
444 linux_nat_prepare_to_resume (child_lp
);
445 ptrace (PTRACE_DETACH
, child_pid
, 0, 0);
447 do_cleanups (old_chain
);
451 struct inferior
*parent_inf
, *child_inf
;
452 struct cleanup
*old_chain
;
454 /* Add process to GDB's tables. */
455 child_inf
= add_inferior (child_pid
);
457 parent_inf
= current_inferior ();
458 child_inf
->attach_flag
= parent_inf
->attach_flag
;
459 copy_terminal_info (child_inf
, parent_inf
);
460 child_inf
->gdbarch
= parent_inf
->gdbarch
;
461 copy_inferior_target_desc_info (child_inf
, parent_inf
);
463 old_chain
= save_inferior_ptid ();
464 save_current_program_space ();
466 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
467 add_thread (inferior_ptid
);
468 child_lp
= add_lwp (inferior_ptid
);
469 child_lp
->stopped
= 1;
470 child_lp
->last_resume_kind
= resume_stop
;
471 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
473 /* If this is a vfork child, then the address-space is
474 shared with the parent. */
477 child_inf
->pspace
= parent_inf
->pspace
;
478 child_inf
->aspace
= parent_inf
->aspace
;
480 /* The parent will be frozen until the child is done
481 with the shared region. Keep track of the
483 child_inf
->vfork_parent
= parent_inf
;
484 child_inf
->pending_detach
= 0;
485 parent_inf
->vfork_child
= child_inf
;
486 parent_inf
->pending_detach
= 0;
490 child_inf
->aspace
= new_address_space ();
491 child_inf
->pspace
= add_program_space (child_inf
->aspace
);
492 child_inf
->removable
= 1;
493 set_current_program_space (child_inf
->pspace
);
494 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
496 /* Let the shared library layer (solib-svr4) learn about
497 this new process, relocate the cloned exec, pull in
498 shared libraries, and install the solib event
499 breakpoint. If a "cloned-VM" event was propagated
500 better throughout the core, this wouldn't be
502 solib_create_inferior_hook (0);
505 /* Let the thread_db layer learn about this new process. */
506 check_for_thread_db ();
508 do_cleanups (old_chain
);
513 struct lwp_info
*parent_lp
;
514 struct inferior
*parent_inf
;
516 parent_inf
= current_inferior ();
518 /* If we detached from the child, then we have to be careful
519 to not insert breakpoints in the parent until the child
520 is done with the shared memory region. However, if we're
521 staying attached to the child, then we can and should
522 insert breakpoints, so that we can debug it. A
523 subsequent child exec or exit is enough to know when does
524 the child stops using the parent's address space. */
525 parent_inf
->waiting_for_vfork_done
= detach_fork
;
526 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
528 parent_lp
= find_lwp_pid (pid_to_ptid (parent_pid
));
529 gdb_assert (linux_supports_tracefork () >= 0);
531 if (linux_supports_tracevforkdone ())
534 fprintf_unfiltered (gdb_stdlog
,
535 "LCFF: waiting for VFORK_DONE on %d\n",
537 parent_lp
->stopped
= 1;
539 /* We'll handle the VFORK_DONE event like any other
540 event, in target_wait. */
544 /* We can't insert breakpoints until the child has
545 finished with the shared memory region. We need to
546 wait until that happens. Ideal would be to just
548 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
549 - waitpid (parent_pid, &status, __WALL);
550 However, most architectures can't handle a syscall
551 being traced on the way out if it wasn't traced on
554 We might also think to loop, continuing the child
555 until it exits or gets a SIGTRAP. One problem is
556 that the child might call ptrace with PTRACE_TRACEME.
558 There's no simple and reliable way to figure out when
559 the vforked child will be done with its copy of the
560 shared memory. We could step it out of the syscall,
561 two instructions, let it go, and then single-step the
562 parent once. When we have hardware single-step, this
563 would work; with software single-step it could still
564 be made to work but we'd have to be able to insert
565 single-step breakpoints in the child, and we'd have
566 to insert -just- the single-step breakpoint in the
567 parent. Very awkward.
569 In the end, the best we can do is to make sure it
570 runs for a little while. Hopefully it will be out of
571 range of any breakpoints we reinsert. Usually this
572 is only the single-step breakpoint at vfork's return
576 fprintf_unfiltered (gdb_stdlog
,
577 "LCFF: no VFORK_DONE "
578 "support, sleeping a bit\n");
582 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
583 and leave it pending. The next linux_nat_resume call
584 will notice a pending event, and bypasses actually
585 resuming the inferior. */
586 parent_lp
->status
= 0;
587 parent_lp
->waitstatus
.kind
= TARGET_WAITKIND_VFORK_DONE
;
588 parent_lp
->stopped
= 1;
590 /* If we're in async mode, need to tell the event loop
591 there's something here to process. */
592 if (target_can_async_p ())
599 struct inferior
*parent_inf
, *child_inf
;
600 struct lwp_info
*child_lp
;
601 struct program_space
*parent_pspace
;
603 if (info_verbose
|| debug_linux_nat
)
605 target_terminal_ours ();
607 fprintf_filtered (gdb_stdlog
,
608 _("Attaching after process %d "
609 "vfork to child process %d.\n"),
610 parent_pid
, child_pid
);
612 fprintf_filtered (gdb_stdlog
,
613 _("Attaching after process %d "
614 "fork to child process %d.\n"),
615 parent_pid
, child_pid
);
618 /* Add the new inferior first, so that the target_detach below
619 doesn't unpush the target. */
621 child_inf
= add_inferior (child_pid
);
623 parent_inf
= current_inferior ();
624 child_inf
->attach_flag
= parent_inf
->attach_flag
;
625 copy_terminal_info (child_inf
, parent_inf
);
626 child_inf
->gdbarch
= parent_inf
->gdbarch
;
627 copy_inferior_target_desc_info (child_inf
, parent_inf
);
629 parent_pspace
= parent_inf
->pspace
;
631 /* If we're vforking, we want to hold on to the parent until the
632 child exits or execs. At child exec or exit time we can
633 remove the old breakpoints from the parent and detach or
634 resume debugging it. Otherwise, detach the parent now; we'll
635 want to reuse it's program/address spaces, but we can't set
636 them to the child before removing breakpoints from the
637 parent, otherwise, the breakpoints module could decide to
638 remove breakpoints from the wrong process (since they'd be
639 assigned to the same address space). */
643 gdb_assert (child_inf
->vfork_parent
== NULL
);
644 gdb_assert (parent_inf
->vfork_child
== NULL
);
645 child_inf
->vfork_parent
= parent_inf
;
646 child_inf
->pending_detach
= 0;
647 parent_inf
->vfork_child
= child_inf
;
648 parent_inf
->pending_detach
= detach_fork
;
649 parent_inf
->waiting_for_vfork_done
= 0;
651 else if (detach_fork
)
652 target_detach (NULL
, 0);
654 /* Note that the detach above makes PARENT_INF dangling. */
656 /* Add the child thread to the appropriate lists, and switch to
657 this new thread, before cloning the program space, and
658 informing the solib layer about this new process. */
660 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
661 add_thread (inferior_ptid
);
662 child_lp
= add_lwp (inferior_ptid
);
663 child_lp
->stopped
= 1;
664 child_lp
->last_resume_kind
= resume_stop
;
666 /* If this is a vfork child, then the address-space is shared
667 with the parent. If we detached from the parent, then we can
668 reuse the parent's program/address spaces. */
669 if (has_vforked
|| detach_fork
)
671 child_inf
->pspace
= parent_pspace
;
672 child_inf
->aspace
= child_inf
->pspace
->aspace
;
676 child_inf
->aspace
= new_address_space ();
677 child_inf
->pspace
= add_program_space (child_inf
->aspace
);
678 child_inf
->removable
= 1;
679 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
680 set_current_program_space (child_inf
->pspace
);
681 clone_program_space (child_inf
->pspace
, parent_pspace
);
683 /* Let the shared library layer (solib-svr4) learn about
684 this new process, relocate the cloned exec, pull in
685 shared libraries, and install the solib event breakpoint.
686 If a "cloned-VM" event was propagated better throughout
687 the core, this wouldn't be required. */
688 solib_create_inferior_hook (0);
691 /* Let the thread_db layer learn about this new process. */
692 check_for_thread_db ();
700 linux_child_insert_fork_catchpoint (struct target_ops
*self
, int pid
)
702 return !linux_supports_tracefork ();
706 linux_child_remove_fork_catchpoint (struct target_ops
*self
, int pid
)
712 linux_child_insert_vfork_catchpoint (struct target_ops
*self
, int pid
)
714 return !linux_supports_tracefork ();
718 linux_child_remove_vfork_catchpoint (struct target_ops
*self
, int pid
)
724 linux_child_insert_exec_catchpoint (struct target_ops
*self
, int pid
)
726 return !linux_supports_tracefork ();
730 linux_child_remove_exec_catchpoint (struct target_ops
*self
, int pid
)
736 linux_child_set_syscall_catchpoint (struct target_ops
*self
,
737 int pid
, int needed
, int any_count
,
738 int table_size
, int *table
)
740 if (!linux_supports_tracesysgood ())
743 /* On GNU/Linux, we ignore the arguments. It means that we only
744 enable the syscall catchpoints, but do not disable them.
746 Also, we do not use the `table' information because we do not
747 filter system calls here. We let GDB do the logic for us. */
751 /* On GNU/Linux there are no real LWP's. The closest thing to LWP's
752 are processes sharing the same VM space. A multi-threaded process
753 is basically a group of such processes. However, such a grouping
754 is almost entirely a user-space issue; the kernel doesn't enforce
755 such a grouping at all (this might change in the future). In
756 general, we'll rely on the threads library (i.e. the GNU/Linux
757 Threads library) to provide such a grouping.
759 It is perfectly well possible to write a multi-threaded application
760 without the assistance of a threads library, by using the clone
761 system call directly. This module should be able to give some
762 rudimentary support for debugging such applications if developers
763 specify the CLONE_PTRACE flag in the clone system call, and are
764 using the Linux kernel 2.4 or above.
766 Note that there are some peculiarities in GNU/Linux that affect
769 - In general one should specify the __WCLONE flag to waitpid in
770 order to make it report events for any of the cloned processes
771 (and leave it out for the initial process). However, if a cloned
772 process has exited the exit status is only reported if the
773 __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
774 we cannot use it since GDB must work on older systems too.
776 - When a traced, cloned process exits and is waited for by the
777 debugger, the kernel reassigns it to the original parent and
778 keeps it around as a "zombie". Somehow, the GNU/Linux Threads
779 library doesn't notice this, which leads to the "zombie problem":
780 When debugged a multi-threaded process that spawns a lot of
781 threads will run out of processes, even if the threads exit,
782 because the "zombies" stay around. */
784 /* List of known LWPs. */
785 struct lwp_info
*lwp_list
;
788 /* Original signal mask. */
789 static sigset_t normal_mask
;
791 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
792 _initialize_linux_nat. */
793 static sigset_t suspend_mask
;
795 /* Signals to block to make that sigsuspend work. */
796 static sigset_t blocked_mask
;
798 /* SIGCHLD action. */
799 struct sigaction sigchld_action
;
801 /* Block child signals (SIGCHLD and linux threads signals), and store
802 the previous mask in PREV_MASK. */
805 block_child_signals (sigset_t
*prev_mask
)
807 /* Make sure SIGCHLD is blocked. */
808 if (!sigismember (&blocked_mask
, SIGCHLD
))
809 sigaddset (&blocked_mask
, SIGCHLD
);
811 sigprocmask (SIG_BLOCK
, &blocked_mask
, prev_mask
);
814 /* Restore child signals mask, previously returned by
815 block_child_signals. */
818 restore_child_signals_mask (sigset_t
*prev_mask
)
820 sigprocmask (SIG_SETMASK
, prev_mask
, NULL
);
823 /* Mask of signals to pass directly to the inferior. */
824 static sigset_t pass_mask
;
826 /* Update signals to pass to the inferior. */
828 linux_nat_pass_signals (struct target_ops
*self
,
829 int numsigs
, unsigned char *pass_signals
)
833 sigemptyset (&pass_mask
);
835 for (signo
= 1; signo
< NSIG
; signo
++)
837 int target_signo
= gdb_signal_from_host (signo
);
838 if (target_signo
< numsigs
&& pass_signals
[target_signo
])
839 sigaddset (&pass_mask
, signo
);
845 /* Prototypes for local functions. */
846 static int stop_wait_callback (struct lwp_info
*lp
, void *data
);
847 static int linux_thread_alive (ptid_t ptid
);
848 static char *linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
);
852 /* Destroy and free LP. */
855 lwp_free (struct lwp_info
*lp
)
857 xfree (lp
->arch_private
);
861 /* Remove all LWPs belong to PID from the lwp list. */
864 purge_lwp_list (int pid
)
866 struct lwp_info
*lp
, *lpprev
, *lpnext
;
870 for (lp
= lwp_list
; lp
; lp
= lpnext
)
874 if (ptid_get_pid (lp
->ptid
) == pid
)
879 lpprev
->next
= lp
->next
;
888 /* Add the LWP specified by PTID to the list. PTID is the first LWP
889 in the process. Return a pointer to the structure describing the
892 This differs from add_lwp in that we don't let the arch specific
893 bits know about this new thread. Current clients of this callback
894 take the opportunity to install watchpoints in the new thread, and
895 we shouldn't do that for the first thread. If we're spawning a
896 child ("run"), the thread executes the shell wrapper first, and we
897 shouldn't touch it until it execs the program we want to debug.
898 For "attach", it'd be okay to call the callback, but it's not
899 necessary, because watchpoints can't yet have been inserted into
902 static struct lwp_info
*
903 add_initial_lwp (ptid_t ptid
)
907 gdb_assert (ptid_lwp_p (ptid
));
909 lp
= (struct lwp_info
*) xmalloc (sizeof (struct lwp_info
));
911 memset (lp
, 0, sizeof (struct lwp_info
));
913 lp
->last_resume_kind
= resume_continue
;
914 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
925 /* Add the LWP specified by PID to the list. Return a pointer to the
926 structure describing the new LWP. The LWP should already be
929 static struct lwp_info
*
930 add_lwp (ptid_t ptid
)
934 lp
= add_initial_lwp (ptid
);
936 /* Let the arch specific bits know about this new thread. Current
937 clients of this callback take the opportunity to install
938 watchpoints in the new thread. We don't do this for the first
939 thread though. See add_initial_lwp. */
940 if (linux_nat_new_thread
!= NULL
)
941 linux_nat_new_thread (lp
);
946 /* Remove the LWP specified by PID from the list. */
949 delete_lwp (ptid_t ptid
)
951 struct lwp_info
*lp
, *lpprev
;
955 for (lp
= lwp_list
; lp
; lpprev
= lp
, lp
= lp
->next
)
956 if (ptid_equal (lp
->ptid
, ptid
))
963 lpprev
->next
= lp
->next
;
970 /* Return a pointer to the structure describing the LWP corresponding
971 to PID. If no corresponding LWP could be found, return NULL. */
973 static struct lwp_info
*
974 find_lwp_pid (ptid_t ptid
)
979 if (ptid_lwp_p (ptid
))
980 lwp
= ptid_get_lwp (ptid
);
982 lwp
= ptid_get_pid (ptid
);
984 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
985 if (lwp
== ptid_get_lwp (lp
->ptid
))
991 /* Call CALLBACK with its second argument set to DATA for every LWP in
992 the list. If CALLBACK returns 1 for a particular LWP, return a
993 pointer to the structure describing that LWP immediately.
994 Otherwise return NULL. */
997 iterate_over_lwps (ptid_t filter
,
998 int (*callback
) (struct lwp_info
*, void *),
1001 struct lwp_info
*lp
, *lpnext
;
1003 for (lp
= lwp_list
; lp
; lp
= lpnext
)
1007 if (ptid_match (lp
->ptid
, filter
))
1009 if ((*callback
) (lp
, data
))
1017 /* Update our internal state when changing from one checkpoint to
1018 another indicated by NEW_PTID. We can only switch single-threaded
1019 applications, so we only create one new LWP, and the previous list
1023 linux_nat_switch_fork (ptid_t new_ptid
)
1025 struct lwp_info
*lp
;
1027 purge_lwp_list (ptid_get_pid (inferior_ptid
));
1029 lp
= add_lwp (new_ptid
);
1032 /* This changes the thread's ptid while preserving the gdb thread
1033 num. Also changes the inferior pid, while preserving the
1035 thread_change_ptid (inferior_ptid
, new_ptid
);
1037 /* We've just told GDB core that the thread changed target id, but,
1038 in fact, it really is a different thread, with different register
1040 registers_changed ();
1043 /* Handle the exit of a single thread LP. */
1046 exit_lwp (struct lwp_info
*lp
)
1048 struct thread_info
*th
= find_thread_ptid (lp
->ptid
);
1052 if (print_thread_events
)
1053 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp
->ptid
));
1055 delete_thread (lp
->ptid
);
1058 delete_lwp (lp
->ptid
);
1061 /* Wait for the LWP specified by LP, which we have just attached to.
1062 Returns a wait status for that LWP, to cache. */
1065 linux_nat_post_attach_wait (ptid_t ptid
, int first
, int *cloned
,
1068 pid_t new_pid
, pid
= ptid_get_lwp (ptid
);
1071 if (linux_proc_pid_is_stopped (pid
))
1073 if (debug_linux_nat
)
1074 fprintf_unfiltered (gdb_stdlog
,
1075 "LNPAW: Attaching to a stopped process\n");
1077 /* The process is definitely stopped. It is in a job control
1078 stop, unless the kernel predates the TASK_STOPPED /
1079 TASK_TRACED distinction, in which case it might be in a
1080 ptrace stop. Make sure it is in a ptrace stop; from there we
1081 can kill it, signal it, et cetera.
1083 First make sure there is a pending SIGSTOP. Since we are
1084 already attached, the process can not transition from stopped
1085 to running without a PTRACE_CONT; so we know this signal will
1086 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1087 probably already in the queue (unless this kernel is old
1088 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1089 is not an RT signal, it can only be queued once. */
1090 kill_lwp (pid
, SIGSTOP
);
1092 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1093 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1094 ptrace (PTRACE_CONT
, pid
, 0, 0);
1097 /* Make sure the initial process is stopped. The user-level threads
1098 layer might want to poke around in the inferior, and that won't
1099 work if things haven't stabilized yet. */
1100 new_pid
= my_waitpid (pid
, &status
, 0);
1101 if (new_pid
== -1 && errno
== ECHILD
)
1104 warning (_("%s is a cloned process"), target_pid_to_str (ptid
));
1106 /* Try again with __WCLONE to check cloned processes. */
1107 new_pid
= my_waitpid (pid
, &status
, __WCLONE
);
1111 gdb_assert (pid
== new_pid
);
1113 if (!WIFSTOPPED (status
))
1115 /* The pid we tried to attach has apparently just exited. */
1116 if (debug_linux_nat
)
1117 fprintf_unfiltered (gdb_stdlog
, "LNPAW: Failed to stop %d: %s",
1118 pid
, status_to_str (status
));
1122 if (WSTOPSIG (status
) != SIGSTOP
)
1125 if (debug_linux_nat
)
1126 fprintf_unfiltered (gdb_stdlog
,
1127 "LNPAW: Received %s after attaching\n",
1128 status_to_str (status
));
1134 /* Attach to the LWP specified by PID. Return 0 if successful, -1 if
1135 the new LWP could not be attached, or 1 if we're already auto
1136 attached to this thread, but haven't processed the
1137 PTRACE_EVENT_CLONE event of its parent thread, so we just ignore
1138 its existance, without considering it an error. */
1141 lin_lwp_attach_lwp (ptid_t ptid
)
1143 struct lwp_info
*lp
;
1146 gdb_assert (ptid_lwp_p (ptid
));
1148 lp
= find_lwp_pid (ptid
);
1149 lwpid
= ptid_get_lwp (ptid
);
1151 /* We assume that we're already attached to any LWP that has an id
1152 equal to the overall process id, and to any LWP that is already
1153 in our list of LWPs. If we're not seeing exit events from threads
1154 and we've had PID wraparound since we last tried to stop all threads,
1155 this assumption might be wrong; fortunately, this is very unlikely
1157 if (lwpid
!= ptid_get_pid (ptid
) && lp
== NULL
)
1159 int status
, cloned
= 0, signalled
= 0;
1161 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) < 0)
1163 if (linux_supports_tracefork ())
1165 /* If we haven't stopped all threads when we get here,
1166 we may have seen a thread listed in thread_db's list,
1167 but not processed the PTRACE_EVENT_CLONE yet. If
1168 that's the case, ignore this new thread, and let
1169 normal event handling discover it later. */
1170 if (in_pid_list_p (stopped_pids
, lwpid
))
1172 /* We've already seen this thread stop, but we
1173 haven't seen the PTRACE_EVENT_CLONE extended
1182 /* See if we've got a stop for this new child
1183 pending. If so, we're already attached. */
1184 new_pid
= my_waitpid (lwpid
, &status
, WNOHANG
);
1185 if (new_pid
== -1 && errno
== ECHILD
)
1186 new_pid
= my_waitpid (lwpid
, &status
, __WCLONE
| WNOHANG
);
1189 if (WIFSTOPPED (status
))
1190 add_to_pid_list (&stopped_pids
, lwpid
, status
);
1196 /* If we fail to attach to the thread, issue a warning,
1197 but continue. One way this can happen is if thread
1198 creation is interrupted; as of Linux kernel 2.6.19, a
1199 bug may place threads in the thread list and then fail
1201 warning (_("Can't attach %s: %s"), target_pid_to_str (ptid
),
1202 safe_strerror (errno
));
1206 if (debug_linux_nat
)
1207 fprintf_unfiltered (gdb_stdlog
,
1208 "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
1209 target_pid_to_str (ptid
));
1211 status
= linux_nat_post_attach_wait (ptid
, 0, &cloned
, &signalled
);
1212 if (!WIFSTOPPED (status
))
1215 lp
= add_lwp (ptid
);
1217 lp
->cloned
= cloned
;
1218 lp
->signalled
= signalled
;
1219 if (WSTOPSIG (status
) != SIGSTOP
)
1222 lp
->status
= status
;
1225 target_post_attach (ptid_get_lwp (lp
->ptid
));
1227 if (debug_linux_nat
)
1229 fprintf_unfiltered (gdb_stdlog
,
1230 "LLAL: waitpid %s received %s\n",
1231 target_pid_to_str (ptid
),
1232 status_to_str (status
));
1237 /* We assume that the LWP representing the original process is
1238 already stopped. Mark it as stopped in the data structure
1239 that the GNU/linux ptrace layer uses to keep track of
1240 threads. Note that this won't have already been done since
1241 the main thread will have, we assume, been stopped by an
1242 attach from a different layer. */
1244 lp
= add_lwp (ptid
);
1248 lp
->last_resume_kind
= resume_stop
;
1253 linux_nat_create_inferior (struct target_ops
*ops
,
1254 char *exec_file
, char *allargs
, char **env
,
1257 #ifdef HAVE_PERSONALITY
1258 int personality_orig
= 0, personality_set
= 0;
1259 #endif /* HAVE_PERSONALITY */
1261 /* The fork_child mechanism is synchronous and calls target_wait, so
1262 we have to mask the async mode. */
1264 #ifdef HAVE_PERSONALITY
1265 if (disable_randomization
)
1268 personality_orig
= personality (0xffffffff);
1269 if (errno
== 0 && !(personality_orig
& ADDR_NO_RANDOMIZE
))
1271 personality_set
= 1;
1272 personality (personality_orig
| ADDR_NO_RANDOMIZE
);
1274 if (errno
!= 0 || (personality_set
1275 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE
)))
1276 warning (_("Error disabling address space randomization: %s"),
1277 safe_strerror (errno
));
1279 #endif /* HAVE_PERSONALITY */
1281 /* Make sure we report all signals during startup. */
1282 linux_nat_pass_signals (ops
, 0, NULL
);
1284 linux_ops
->to_create_inferior (ops
, exec_file
, allargs
, env
, from_tty
);
1286 #ifdef HAVE_PERSONALITY
1287 if (personality_set
)
1290 personality (personality_orig
);
1292 warning (_("Error restoring address space randomization: %s"),
1293 safe_strerror (errno
));
1295 #endif /* HAVE_PERSONALITY */
1299 linux_nat_attach (struct target_ops
*ops
, char *args
, int from_tty
)
1301 struct lwp_info
*lp
;
1304 volatile struct gdb_exception ex
;
1306 /* Make sure we report all signals during attach. */
1307 linux_nat_pass_signals (ops
, 0, NULL
);
1309 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
1311 linux_ops
->to_attach (ops
, args
, from_tty
);
1315 pid_t pid
= parse_pid_to_attach (args
);
1316 struct buffer buffer
;
1317 char *message
, *buffer_s
;
1319 message
= xstrdup (ex
.message
);
1320 make_cleanup (xfree
, message
);
1322 buffer_init (&buffer
);
1323 linux_ptrace_attach_fail_reason (pid
, &buffer
);
1325 buffer_grow_str0 (&buffer
, "");
1326 buffer_s
= buffer_finish (&buffer
);
1327 make_cleanup (xfree
, buffer_s
);
1329 if (*buffer_s
!= '\0')
1330 throw_error (ex
.error
, "warning: %s\n%s", buffer_s
, message
);
1332 throw_error (ex
.error
, "%s", message
);
1335 /* The ptrace base target adds the main thread with (pid,0,0)
1336 format. Decorate it with lwp info. */
1337 ptid
= ptid_build (ptid_get_pid (inferior_ptid
),
1338 ptid_get_pid (inferior_ptid
),
1340 thread_change_ptid (inferior_ptid
, ptid
);
1342 /* Add the initial process as the first LWP to the list. */
1343 lp
= add_initial_lwp (ptid
);
1345 status
= linux_nat_post_attach_wait (lp
->ptid
, 1, &lp
->cloned
,
1347 if (!WIFSTOPPED (status
))
1349 if (WIFEXITED (status
))
1351 int exit_code
= WEXITSTATUS (status
);
1353 target_terminal_ours ();
1354 target_mourn_inferior ();
1356 error (_("Unable to attach: program exited normally."));
1358 error (_("Unable to attach: program exited with code %d."),
1361 else if (WIFSIGNALED (status
))
1363 enum gdb_signal signo
;
1365 target_terminal_ours ();
1366 target_mourn_inferior ();
1368 signo
= gdb_signal_from_host (WTERMSIG (status
));
1369 error (_("Unable to attach: program terminated with signal "
1371 gdb_signal_to_name (signo
),
1372 gdb_signal_to_string (signo
));
1375 internal_error (__FILE__
, __LINE__
,
1376 _("unexpected status %d for PID %ld"),
1377 status
, (long) ptid_get_lwp (ptid
));
1382 /* Save the wait status to report later. */
1384 if (debug_linux_nat
)
1385 fprintf_unfiltered (gdb_stdlog
,
1386 "LNA: waitpid %ld, saving status %s\n",
1387 (long) ptid_get_pid (lp
->ptid
), status_to_str (status
));
1389 lp
->status
= status
;
1391 if (target_can_async_p ())
1392 target_async (inferior_event_handler
, 0);
1395 /* Get pending status of LP. */
1397 get_pending_status (struct lwp_info
*lp
, int *status
)
1399 enum gdb_signal signo
= GDB_SIGNAL_0
;
1401 /* If we paused threads momentarily, we may have stored pending
1402 events in lp->status or lp->waitstatus (see stop_wait_callback),
1403 and GDB core hasn't seen any signal for those threads.
1404 Otherwise, the last signal reported to the core is found in the
1405 thread object's stop_signal.
1407 There's a corner case that isn't handled here at present. Only
1408 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1409 stop_signal make sense as a real signal to pass to the inferior.
1410 Some catchpoint related events, like
1411 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1412 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1413 those traps are debug API (ptrace in our case) related and
1414 induced; the inferior wouldn't see them if it wasn't being
1415 traced. Hence, we should never pass them to the inferior, even
1416 when set to pass state. Since this corner case isn't handled by
1417 infrun.c when proceeding with a signal, for consistency, neither
1418 do we handle it here (or elsewhere in the file we check for
1419 signal pass state). Normally SIGTRAP isn't set to pass state, so
1420 this is really a corner case. */
1422 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
1423 signo
= GDB_SIGNAL_0
; /* a pending ptrace event, not a real signal. */
1424 else if (lp
->status
)
1425 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1426 else if (non_stop
&& !is_executing (lp
->ptid
))
1428 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1430 signo
= tp
->suspend
.stop_signal
;
1434 struct target_waitstatus last
;
1437 get_last_target_status (&last_ptid
, &last
);
1439 if (ptid_get_lwp (lp
->ptid
) == ptid_get_lwp (last_ptid
))
1441 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1443 signo
= tp
->suspend
.stop_signal
;
1449 if (signo
== GDB_SIGNAL_0
)
1451 if (debug_linux_nat
)
1452 fprintf_unfiltered (gdb_stdlog
,
1453 "GPT: lwp %s has no pending signal\n",
1454 target_pid_to_str (lp
->ptid
));
1456 else if (!signal_pass_state (signo
))
1458 if (debug_linux_nat
)
1459 fprintf_unfiltered (gdb_stdlog
,
1460 "GPT: lwp %s had signal %s, "
1461 "but it is in no pass state\n",
1462 target_pid_to_str (lp
->ptid
),
1463 gdb_signal_to_string (signo
));
1467 *status
= W_STOPCODE (gdb_signal_to_host (signo
));
1469 if (debug_linux_nat
)
1470 fprintf_unfiltered (gdb_stdlog
,
1471 "GPT: lwp %s has pending signal %s\n",
1472 target_pid_to_str (lp
->ptid
),
1473 gdb_signal_to_string (signo
));
1480 detach_callback (struct lwp_info
*lp
, void *data
)
1482 gdb_assert (lp
->status
== 0 || WIFSTOPPED (lp
->status
));
1484 if (debug_linux_nat
&& lp
->status
)
1485 fprintf_unfiltered (gdb_stdlog
, "DC: Pending %s for %s on detach.\n",
1486 strsignal (WSTOPSIG (lp
->status
)),
1487 target_pid_to_str (lp
->ptid
));
1489 /* If there is a pending SIGSTOP, get rid of it. */
1492 if (debug_linux_nat
)
1493 fprintf_unfiltered (gdb_stdlog
,
1494 "DC: Sending SIGCONT to %s\n",
1495 target_pid_to_str (lp
->ptid
));
1497 kill_lwp (ptid_get_lwp (lp
->ptid
), SIGCONT
);
1501 /* We don't actually detach from the LWP that has an id equal to the
1502 overall process id just yet. */
1503 if (ptid_get_lwp (lp
->ptid
) != ptid_get_pid (lp
->ptid
))
1507 /* Pass on any pending signal for this LWP. */
1508 get_pending_status (lp
, &status
);
1510 if (linux_nat_prepare_to_resume
!= NULL
)
1511 linux_nat_prepare_to_resume (lp
);
1513 if (ptrace (PTRACE_DETACH
, ptid_get_lwp (lp
->ptid
), 0,
1514 WSTOPSIG (status
)) < 0)
1515 error (_("Can't detach %s: %s"), target_pid_to_str (lp
->ptid
),
1516 safe_strerror (errno
));
1518 if (debug_linux_nat
)
1519 fprintf_unfiltered (gdb_stdlog
,
1520 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1521 target_pid_to_str (lp
->ptid
),
1522 strsignal (WSTOPSIG (status
)));
1524 delete_lwp (lp
->ptid
);
1531 linux_nat_detach (struct target_ops
*ops
, const char *args
, int from_tty
)
1535 struct lwp_info
*main_lwp
;
1537 pid
= ptid_get_pid (inferior_ptid
);
1539 /* Don't unregister from the event loop, as there may be other
1540 inferiors running. */
1542 /* Stop all threads before detaching. ptrace requires that the
1543 thread is stopped to sucessfully detach. */
1544 iterate_over_lwps (pid_to_ptid (pid
), stop_callback
, NULL
);
1545 /* ... and wait until all of them have reported back that
1546 they're no longer running. */
1547 iterate_over_lwps (pid_to_ptid (pid
), stop_wait_callback
, NULL
);
1549 iterate_over_lwps (pid_to_ptid (pid
), detach_callback
, NULL
);
1551 /* Only the initial process should be left right now. */
1552 gdb_assert (num_lwps (ptid_get_pid (inferior_ptid
)) == 1);
1554 main_lwp
= find_lwp_pid (pid_to_ptid (pid
));
1556 /* Pass on any pending signal for the last LWP. */
1557 if ((args
== NULL
|| *args
== '\0')
1558 && get_pending_status (main_lwp
, &status
) != -1
1559 && WIFSTOPPED (status
))
1563 /* Put the signal number in ARGS so that inf_ptrace_detach will
1564 pass it along with PTRACE_DETACH. */
1566 xsnprintf (tem
, 8, "%d", (int) WSTOPSIG (status
));
1568 if (debug_linux_nat
)
1569 fprintf_unfiltered (gdb_stdlog
,
1570 "LND: Sending signal %s to %s\n",
1572 target_pid_to_str (main_lwp
->ptid
));
1575 if (linux_nat_prepare_to_resume
!= NULL
)
1576 linux_nat_prepare_to_resume (main_lwp
);
1577 delete_lwp (main_lwp
->ptid
);
1579 if (forks_exist_p ())
1581 /* Multi-fork case. The current inferior_ptid is being detached
1582 from, but there are other viable forks to debug. Detach from
1583 the current fork, and context-switch to the first
1585 linux_fork_detach (args
, from_tty
);
1588 linux_ops
->to_detach (ops
, args
, from_tty
);
1594 resume_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1598 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
1600 if (inf
->vfork_child
!= NULL
)
1602 if (debug_linux_nat
)
1603 fprintf_unfiltered (gdb_stdlog
,
1604 "RC: Not resuming %s (vfork parent)\n",
1605 target_pid_to_str (lp
->ptid
));
1607 else if (lp
->status
== 0
1608 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
1610 if (debug_linux_nat
)
1611 fprintf_unfiltered (gdb_stdlog
,
1612 "RC: Resuming sibling %s, %s, %s\n",
1613 target_pid_to_str (lp
->ptid
),
1614 (signo
!= GDB_SIGNAL_0
1615 ? strsignal (gdb_signal_to_host (signo
))
1617 step
? "step" : "resume");
1619 if (linux_nat_prepare_to_resume
!= NULL
)
1620 linux_nat_prepare_to_resume (lp
);
1621 linux_ops
->to_resume (linux_ops
,
1622 pid_to_ptid (ptid_get_lwp (lp
->ptid
)),
1626 lp
->stopped_by_watchpoint
= 0;
1630 if (debug_linux_nat
)
1631 fprintf_unfiltered (gdb_stdlog
,
1632 "RC: Not resuming sibling %s (has pending)\n",
1633 target_pid_to_str (lp
->ptid
));
1638 if (debug_linux_nat
)
1639 fprintf_unfiltered (gdb_stdlog
,
1640 "RC: Not resuming sibling %s (not stopped)\n",
1641 target_pid_to_str (lp
->ptid
));
1645 /* Resume LWP, with the last stop signal, if it is in pass state. */
1648 linux_nat_resume_callback (struct lwp_info
*lp
, void *data
)
1650 enum gdb_signal signo
= GDB_SIGNAL_0
;
1654 struct thread_info
*thread
;
1656 thread
= find_thread_ptid (lp
->ptid
);
1659 if (signal_pass_state (thread
->suspend
.stop_signal
))
1660 signo
= thread
->suspend
.stop_signal
;
1661 thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
1665 resume_lwp (lp
, 0, signo
);
1670 resume_clear_callback (struct lwp_info
*lp
, void *data
)
1673 lp
->last_resume_kind
= resume_stop
;
1678 resume_set_callback (struct lwp_info
*lp
, void *data
)
1681 lp
->last_resume_kind
= resume_continue
;
1686 linux_nat_resume (struct target_ops
*ops
,
1687 ptid_t ptid
, int step
, enum gdb_signal signo
)
1689 struct lwp_info
*lp
;
1692 if (debug_linux_nat
)
1693 fprintf_unfiltered (gdb_stdlog
,
1694 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1695 step
? "step" : "resume",
1696 target_pid_to_str (ptid
),
1697 (signo
!= GDB_SIGNAL_0
1698 ? strsignal (gdb_signal_to_host (signo
)) : "0"),
1699 target_pid_to_str (inferior_ptid
));
1701 /* A specific PTID means `step only this process id'. */
1702 resume_many
= (ptid_equal (minus_one_ptid
, ptid
)
1703 || ptid_is_pid (ptid
));
1705 /* Mark the lwps we're resuming as resumed. */
1706 iterate_over_lwps (ptid
, resume_set_callback
, NULL
);
1708 /* See if it's the current inferior that should be handled
1711 lp
= find_lwp_pid (inferior_ptid
);
1713 lp
= find_lwp_pid (ptid
);
1714 gdb_assert (lp
!= NULL
);
1716 /* Remember if we're stepping. */
1718 lp
->last_resume_kind
= step
? resume_step
: resume_continue
;
1720 /* If we have a pending wait status for this thread, there is no
1721 point in resuming the process. But first make sure that
1722 linux_nat_wait won't preemptively handle the event - we
1723 should never take this short-circuit if we are going to
1724 leave LP running, since we have skipped resuming all the
1725 other threads. This bit of code needs to be synchronized
1726 with linux_nat_wait. */
1728 if (lp
->status
&& WIFSTOPPED (lp
->status
))
1731 && WSTOPSIG (lp
->status
)
1732 && sigismember (&pass_mask
, WSTOPSIG (lp
->status
)))
1734 if (debug_linux_nat
)
1735 fprintf_unfiltered (gdb_stdlog
,
1736 "LLR: Not short circuiting for ignored "
1737 "status 0x%x\n", lp
->status
);
1739 /* FIXME: What should we do if we are supposed to continue
1740 this thread with a signal? */
1741 gdb_assert (signo
== GDB_SIGNAL_0
);
1742 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1747 if (lp
->status
|| lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
1749 /* FIXME: What should we do if we are supposed to continue
1750 this thread with a signal? */
1751 gdb_assert (signo
== GDB_SIGNAL_0
);
1753 if (debug_linux_nat
)
1754 fprintf_unfiltered (gdb_stdlog
,
1755 "LLR: Short circuiting for status 0x%x\n",
1758 if (target_can_async_p ())
1760 target_async (inferior_event_handler
, 0);
1761 /* Tell the event loop we have something to process. */
1767 /* Mark LWP as not stopped to prevent it from being continued by
1768 linux_nat_resume_callback. */
1772 iterate_over_lwps (ptid
, linux_nat_resume_callback
, NULL
);
1774 /* Convert to something the lower layer understands. */
1775 ptid
= pid_to_ptid (ptid_get_lwp (lp
->ptid
));
1777 if (linux_nat_prepare_to_resume
!= NULL
)
1778 linux_nat_prepare_to_resume (lp
);
1779 linux_ops
->to_resume (linux_ops
, ptid
, step
, signo
);
1780 lp
->stopped_by_watchpoint
= 0;
1782 if (debug_linux_nat
)
1783 fprintf_unfiltered (gdb_stdlog
,
1784 "LLR: %s %s, %s (resume event thread)\n",
1785 step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1786 target_pid_to_str (ptid
),
1787 (signo
!= GDB_SIGNAL_0
1788 ? strsignal (gdb_signal_to_host (signo
)) : "0"));
1790 if (target_can_async_p ())
1791 target_async (inferior_event_handler
, 0);
1794 /* Send a signal to an LWP. */
1797 kill_lwp (int lwpid
, int signo
)
1799 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1800 fails, then we are not using nptl threads and we should be using kill. */
1802 #ifdef HAVE_TKILL_SYSCALL
1804 static int tkill_failed
;
1811 ret
= syscall (__NR_tkill
, lwpid
, signo
);
1812 if (errno
!= ENOSYS
)
1819 return kill (lwpid
, signo
);
1822 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1823 event, check if the core is interested in it: if not, ignore the
1824 event, and keep waiting; otherwise, we need to toggle the LWP's
1825 syscall entry/exit status, since the ptrace event itself doesn't
1826 indicate it, and report the trap to higher layers. */
1829 linux_handle_syscall_trap (struct lwp_info
*lp
, int stopping
)
1831 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1832 struct gdbarch
*gdbarch
= target_thread_architecture (lp
->ptid
);
1833 int syscall_number
= (int) gdbarch_get_syscall_number (gdbarch
, lp
->ptid
);
1837 /* If we're stopping threads, there's a SIGSTOP pending, which
1838 makes it so that the LWP reports an immediate syscall return,
1839 followed by the SIGSTOP. Skip seeing that "return" using
1840 PTRACE_CONT directly, and let stop_wait_callback collect the
1841 SIGSTOP. Later when the thread is resumed, a new syscall
1842 entry event. If we didn't do this (and returned 0), we'd
1843 leave a syscall entry pending, and our caller, by using
1844 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1845 itself. Later, when the user re-resumes this LWP, we'd see
1846 another syscall entry event and we'd mistake it for a return.
1848 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1849 (leaving immediately with LWP->signalled set, without issuing
1850 a PTRACE_CONT), it would still be problematic to leave this
1851 syscall enter pending, as later when the thread is resumed,
1852 it would then see the same syscall exit mentioned above,
1853 followed by the delayed SIGSTOP, while the syscall didn't
1854 actually get to execute. It seems it would be even more
1855 confusing to the user. */
1857 if (debug_linux_nat
)
1858 fprintf_unfiltered (gdb_stdlog
,
1859 "LHST: ignoring syscall %d "
1860 "for LWP %ld (stopping threads), "
1861 "resuming with PTRACE_CONT for SIGSTOP\n",
1863 ptid_get_lwp (lp
->ptid
));
1865 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1866 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
1870 if (catch_syscall_enabled ())
1872 /* Always update the entry/return state, even if this particular
1873 syscall isn't interesting to the core now. In async mode,
1874 the user could install a new catchpoint for this syscall
1875 between syscall enter/return, and we'll need to know to
1876 report a syscall return if that happens. */
1877 lp
->syscall_state
= (lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1878 ? TARGET_WAITKIND_SYSCALL_RETURN
1879 : TARGET_WAITKIND_SYSCALL_ENTRY
);
1881 if (catching_syscall_number (syscall_number
))
1883 /* Alright, an event to report. */
1884 ourstatus
->kind
= lp
->syscall_state
;
1885 ourstatus
->value
.syscall_number
= syscall_number
;
1887 if (debug_linux_nat
)
1888 fprintf_unfiltered (gdb_stdlog
,
1889 "LHST: stopping for %s of syscall %d"
1892 == TARGET_WAITKIND_SYSCALL_ENTRY
1893 ? "entry" : "return",
1895 ptid_get_lwp (lp
->ptid
));
1899 if (debug_linux_nat
)
1900 fprintf_unfiltered (gdb_stdlog
,
1901 "LHST: ignoring %s of syscall %d "
1903 lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1904 ? "entry" : "return",
1906 ptid_get_lwp (lp
->ptid
));
1910 /* If we had been syscall tracing, and hence used PT_SYSCALL
1911 before on this LWP, it could happen that the user removes all
1912 syscall catchpoints before we get to process this event.
1913 There are two noteworthy issues here:
1915 - When stopped at a syscall entry event, resuming with
1916 PT_STEP still resumes executing the syscall and reports a
1919 - Only PT_SYSCALL catches syscall enters. If we last
1920 single-stepped this thread, then this event can't be a
1921 syscall enter. If we last single-stepped this thread, this
1922 has to be a syscall exit.
1924 The points above mean that the next resume, be it PT_STEP or
1925 PT_CONTINUE, can not trigger a syscall trace event. */
1926 if (debug_linux_nat
)
1927 fprintf_unfiltered (gdb_stdlog
,
1928 "LHST: caught syscall event "
1929 "with no syscall catchpoints."
1930 " %d for LWP %ld, ignoring\n",
1932 ptid_get_lwp (lp
->ptid
));
1933 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1936 /* The core isn't interested in this event. For efficiency, avoid
1937 stopping all threads only to have the core resume them all again.
1938 Since we're not stopping threads, if we're still syscall tracing
1939 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1940 subsequent syscall. Simply resume using the inf-ptrace layer,
1941 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1943 /* Note that gdbarch_get_syscall_number may access registers, hence
1945 registers_changed ();
1946 if (linux_nat_prepare_to_resume
!= NULL
)
1947 linux_nat_prepare_to_resume (lp
);
1948 linux_ops
->to_resume (linux_ops
, pid_to_ptid (ptid_get_lwp (lp
->ptid
)),
1949 lp
->step
, GDB_SIGNAL_0
);
1953 /* Handle a GNU/Linux extended wait response. If we see a clone
1954 event, we need to add the new LWP to our list (and not report the
1955 trap to higher layers). This function returns non-zero if the
1956 event should be ignored and we should wait again. If STOPPING is
1957 true, the new LWP remains stopped, otherwise it is continued. */
1960 linux_handle_extended_wait (struct lwp_info
*lp
, int status
,
1963 int pid
= ptid_get_lwp (lp
->ptid
);
1964 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1965 int event
= status
>> 16;
1967 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
1968 || event
== PTRACE_EVENT_CLONE
)
1970 unsigned long new_pid
;
1973 ptrace (PTRACE_GETEVENTMSG
, pid
, 0, &new_pid
);
1975 /* If we haven't already seen the new PID stop, wait for it now. */
1976 if (! pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
1978 /* The new child has a pending SIGSTOP. We can't affect it until it
1979 hits the SIGSTOP, but we're already attached. */
1980 ret
= my_waitpid (new_pid
, &status
,
1981 (event
== PTRACE_EVENT_CLONE
) ? __WCLONE
: 0);
1983 perror_with_name (_("waiting for new child"));
1984 else if (ret
!= new_pid
)
1985 internal_error (__FILE__
, __LINE__
,
1986 _("wait returned unexpected PID %d"), ret
);
1987 else if (!WIFSTOPPED (status
))
1988 internal_error (__FILE__
, __LINE__
,
1989 _("wait returned unexpected status 0x%x"), status
);
1992 ourstatus
->value
.related_pid
= ptid_build (new_pid
, new_pid
, 0);
1994 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
)
1996 /* The arch-specific native code may need to know about new
1997 forks even if those end up never mapped to an
1999 if (linux_nat_new_fork
!= NULL
)
2000 linux_nat_new_fork (lp
, new_pid
);
2003 if (event
== PTRACE_EVENT_FORK
2004 && linux_fork_checkpointing_p (ptid_get_pid (lp
->ptid
)))
2006 /* Handle checkpointing by linux-fork.c here as a special
2007 case. We don't want the follow-fork-mode or 'catch fork'
2008 to interfere with this. */
2010 /* This won't actually modify the breakpoint list, but will
2011 physically remove the breakpoints from the child. */
2012 detach_breakpoints (ptid_build (new_pid
, new_pid
, 0));
2014 /* Retain child fork in ptrace (stopped) state. */
2015 if (!find_fork_pid (new_pid
))
2018 /* Report as spurious, so that infrun doesn't want to follow
2019 this fork. We're actually doing an infcall in
2021 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
2023 /* Report the stop to the core. */
2027 if (event
== PTRACE_EVENT_FORK
)
2028 ourstatus
->kind
= TARGET_WAITKIND_FORKED
;
2029 else if (event
== PTRACE_EVENT_VFORK
)
2030 ourstatus
->kind
= TARGET_WAITKIND_VFORKED
;
2033 struct lwp_info
*new_lp
;
2035 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2037 if (debug_linux_nat
)
2038 fprintf_unfiltered (gdb_stdlog
,
2039 "LHEW: Got clone event "
2040 "from LWP %d, new child is LWP %ld\n",
2043 new_lp
= add_lwp (ptid_build (ptid_get_pid (lp
->ptid
), new_pid
, 0));
2045 new_lp
->stopped
= 1;
2047 if (WSTOPSIG (status
) != SIGSTOP
)
2049 /* This can happen if someone starts sending signals to
2050 the new thread before it gets a chance to run, which
2051 have a lower number than SIGSTOP (e.g. SIGUSR1).
2052 This is an unlikely case, and harder to handle for
2053 fork / vfork than for clone, so we do not try - but
2054 we handle it for clone events here. We'll send
2055 the other signal on to the thread below. */
2057 new_lp
->signalled
= 1;
2061 struct thread_info
*tp
;
2063 /* When we stop for an event in some other thread, and
2064 pull the thread list just as this thread has cloned,
2065 we'll have seen the new thread in the thread_db list
2066 before handling the CLONE event (glibc's
2067 pthread_create adds the new thread to the thread list
2068 before clone'ing, and has the kernel fill in the
2069 thread's tid on the clone call with
2070 CLONE_PARENT_SETTID). If that happened, and the core
2071 had requested the new thread to stop, we'll have
2072 killed it with SIGSTOP. But since SIGSTOP is not an
2073 RT signal, it can only be queued once. We need to be
2074 careful to not resume the LWP if we wanted it to
2075 stop. In that case, we'll leave the SIGSTOP pending.
2076 It will later be reported as GDB_SIGNAL_0. */
2077 tp
= find_thread_ptid (new_lp
->ptid
);
2078 if (tp
!= NULL
&& tp
->stop_requested
)
2079 new_lp
->last_resume_kind
= resume_stop
;
2086 /* Add the new thread to GDB's lists as soon as possible
2089 1) the frontend doesn't have to wait for a stop to
2092 2) we tag it with the correct running state. */
2094 /* If the thread_db layer is active, let it know about
2095 this new thread, and add it to GDB's list. */
2096 if (!thread_db_attach_lwp (new_lp
->ptid
))
2098 /* We're not using thread_db. Add it to GDB's
2100 target_post_attach (ptid_get_lwp (new_lp
->ptid
));
2101 add_thread (new_lp
->ptid
);
2106 set_running (new_lp
->ptid
, 1);
2107 set_executing (new_lp
->ptid
, 1);
2108 /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced
2110 new_lp
->last_resume_kind
= resume_continue
;
2116 /* We created NEW_LP so it cannot yet contain STATUS. */
2117 gdb_assert (new_lp
->status
== 0);
2119 /* Save the wait status to report later. */
2120 if (debug_linux_nat
)
2121 fprintf_unfiltered (gdb_stdlog
,
2122 "LHEW: waitpid of new LWP %ld, "
2123 "saving status %s\n",
2124 (long) ptid_get_lwp (new_lp
->ptid
),
2125 status_to_str (status
));
2126 new_lp
->status
= status
;
2129 /* Note the need to use the low target ops to resume, to
2130 handle resuming with PT_SYSCALL if we have syscall
2134 new_lp
->resumed
= 1;
2138 gdb_assert (new_lp
->last_resume_kind
== resume_continue
);
2139 if (debug_linux_nat
)
2140 fprintf_unfiltered (gdb_stdlog
,
2141 "LHEW: resuming new LWP %ld\n",
2142 ptid_get_lwp (new_lp
->ptid
));
2143 if (linux_nat_prepare_to_resume
!= NULL
)
2144 linux_nat_prepare_to_resume (new_lp
);
2145 linux_ops
->to_resume (linux_ops
, pid_to_ptid (new_pid
),
2147 new_lp
->stopped
= 0;
2151 if (debug_linux_nat
)
2152 fprintf_unfiltered (gdb_stdlog
,
2153 "LHEW: resuming parent LWP %d\n", pid
);
2154 if (linux_nat_prepare_to_resume
!= NULL
)
2155 linux_nat_prepare_to_resume (lp
);
2156 linux_ops
->to_resume (linux_ops
,
2157 pid_to_ptid (ptid_get_lwp (lp
->ptid
)),
2166 if (event
== PTRACE_EVENT_EXEC
)
2168 if (debug_linux_nat
)
2169 fprintf_unfiltered (gdb_stdlog
,
2170 "LHEW: Got exec event from LWP %ld\n",
2171 ptid_get_lwp (lp
->ptid
));
2173 ourstatus
->kind
= TARGET_WAITKIND_EXECD
;
2174 ourstatus
->value
.execd_pathname
2175 = xstrdup (linux_child_pid_to_exec_file (NULL
, pid
));
2180 if (event
== PTRACE_EVENT_VFORK_DONE
)
2182 if (current_inferior ()->waiting_for_vfork_done
)
2184 if (debug_linux_nat
)
2185 fprintf_unfiltered (gdb_stdlog
,
2186 "LHEW: Got expected PTRACE_EVENT_"
2187 "VFORK_DONE from LWP %ld: stopping\n",
2188 ptid_get_lwp (lp
->ptid
));
2190 ourstatus
->kind
= TARGET_WAITKIND_VFORK_DONE
;
2194 if (debug_linux_nat
)
2195 fprintf_unfiltered (gdb_stdlog
,
2196 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2197 "from LWP %ld: resuming\n",
2198 ptid_get_lwp (lp
->ptid
));
2199 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
2203 internal_error (__FILE__
, __LINE__
,
2204 _("unknown ptrace event %d"), event
);
2207 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2211 wait_lwp (struct lwp_info
*lp
)
2215 int thread_dead
= 0;
2218 gdb_assert (!lp
->stopped
);
2219 gdb_assert (lp
->status
== 0);
2221 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2222 block_child_signals (&prev_mask
);
2226 /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind
2227 was right and we should just call sigsuspend. */
2229 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), &status
, WNOHANG
);
2230 if (pid
== -1 && errno
== ECHILD
)
2231 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), &status
, __WCLONE
| WNOHANG
);
2232 if (pid
== -1 && errno
== ECHILD
)
2234 /* The thread has previously exited. We need to delete it
2235 now because, for some vendor 2.4 kernels with NPTL
2236 support backported, there won't be an exit event unless
2237 it is the main thread. 2.6 kernels will report an exit
2238 event for each thread that exits, as expected. */
2240 if (debug_linux_nat
)
2241 fprintf_unfiltered (gdb_stdlog
, "WL: %s vanished.\n",
2242 target_pid_to_str (lp
->ptid
));
2247 /* Bugs 10970, 12702.
2248 Thread group leader may have exited in which case we'll lock up in
2249 waitpid if there are other threads, even if they are all zombies too.
2250 Basically, we're not supposed to use waitpid this way.
2251 __WCLONE is not applicable for the leader so we can't use that.
2252 LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED
2253 process; it gets ESRCH both for the zombie and for running processes.
2255 As a workaround, check if we're waiting for the thread group leader and
2256 if it's a zombie, and avoid calling waitpid if it is.
2258 This is racy, what if the tgl becomes a zombie right after we check?
2259 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2260 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2262 if (ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
)
2263 && linux_proc_pid_is_zombie (ptid_get_lwp (lp
->ptid
)))
2266 if (debug_linux_nat
)
2267 fprintf_unfiltered (gdb_stdlog
,
2268 "WL: Thread group leader %s vanished.\n",
2269 target_pid_to_str (lp
->ptid
));
2273 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2274 get invoked despite our caller had them intentionally blocked by
2275 block_child_signals. This is sensitive only to the loop of
2276 linux_nat_wait_1 and there if we get called my_waitpid gets called
2277 again before it gets to sigsuspend so we can safely let the handlers
2278 get executed here. */
2280 sigsuspend (&suspend_mask
);
2283 restore_child_signals_mask (&prev_mask
);
2287 gdb_assert (pid
== ptid_get_lwp (lp
->ptid
));
2289 if (debug_linux_nat
)
2291 fprintf_unfiltered (gdb_stdlog
,
2292 "WL: waitpid %s received %s\n",
2293 target_pid_to_str (lp
->ptid
),
2294 status_to_str (status
));
2297 /* Check if the thread has exited. */
2298 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2301 if (debug_linux_nat
)
2302 fprintf_unfiltered (gdb_stdlog
, "WL: %s exited.\n",
2303 target_pid_to_str (lp
->ptid
));
2313 gdb_assert (WIFSTOPPED (status
));
2315 /* Handle GNU/Linux's syscall SIGTRAPs. */
2316 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2318 /* No longer need the sysgood bit. The ptrace event ends up
2319 recorded in lp->waitstatus if we care for it. We can carry
2320 on handling the event like a regular SIGTRAP from here
2322 status
= W_STOPCODE (SIGTRAP
);
2323 if (linux_handle_syscall_trap (lp
, 1))
2324 return wait_lwp (lp
);
2327 /* Handle GNU/Linux's extended waitstatus for trace events. */
2328 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 != 0)
2330 if (debug_linux_nat
)
2331 fprintf_unfiltered (gdb_stdlog
,
2332 "WL: Handling extended status 0x%06x\n",
2334 if (linux_handle_extended_wait (lp
, status
, 1))
2335 return wait_lwp (lp
);
2341 /* Send a SIGSTOP to LP. */
2344 stop_callback (struct lwp_info
*lp
, void *data
)
2346 if (!lp
->stopped
&& !lp
->signalled
)
2350 if (debug_linux_nat
)
2352 fprintf_unfiltered (gdb_stdlog
,
2353 "SC: kill %s **<SIGSTOP>**\n",
2354 target_pid_to_str (lp
->ptid
));
2357 ret
= kill_lwp (ptid_get_lwp (lp
->ptid
), SIGSTOP
);
2358 if (debug_linux_nat
)
2360 fprintf_unfiltered (gdb_stdlog
,
2361 "SC: lwp kill %d %s\n",
2363 errno
? safe_strerror (errno
) : "ERRNO-OK");
2367 gdb_assert (lp
->status
== 0);
2373 /* Request a stop on LWP. */
2376 linux_stop_lwp (struct lwp_info
*lwp
)
2378 stop_callback (lwp
, NULL
);
2381 /* Return non-zero if LWP PID has a pending SIGINT. */
2384 linux_nat_has_pending_sigint (int pid
)
2386 sigset_t pending
, blocked
, ignored
;
2388 linux_proc_pending_signals (pid
, &pending
, &blocked
, &ignored
);
2390 if (sigismember (&pending
, SIGINT
)
2391 && !sigismember (&ignored
, SIGINT
))
2397 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2400 set_ignore_sigint (struct lwp_info
*lp
, void *data
)
2402 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2403 flag to consume the next one. */
2404 if (lp
->stopped
&& lp
->status
!= 0 && WIFSTOPPED (lp
->status
)
2405 && WSTOPSIG (lp
->status
) == SIGINT
)
2408 lp
->ignore_sigint
= 1;
2413 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2414 This function is called after we know the LWP has stopped; if the LWP
2415 stopped before the expected SIGINT was delivered, then it will never have
2416 arrived. Also, if the signal was delivered to a shared queue and consumed
2417 by a different thread, it will never be delivered to this LWP. */
2420 maybe_clear_ignore_sigint (struct lwp_info
*lp
)
2422 if (!lp
->ignore_sigint
)
2425 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp
->ptid
)))
2427 if (debug_linux_nat
)
2428 fprintf_unfiltered (gdb_stdlog
,
2429 "MCIS: Clearing bogus flag for %s\n",
2430 target_pid_to_str (lp
->ptid
));
2431 lp
->ignore_sigint
= 0;
2435 /* Fetch the possible triggered data watchpoint info and store it in
2438 On some archs, like x86, that use debug registers to set
2439 watchpoints, it's possible that the way to know which watched
2440 address trapped, is to check the register that is used to select
2441 which address to watch. Problem is, between setting the watchpoint
2442 and reading back which data address trapped, the user may change
2443 the set of watchpoints, and, as a consequence, GDB changes the
2444 debug registers in the inferior. To avoid reading back a stale
2445 stopped-data-address when that happens, we cache in LP the fact
2446 that a watchpoint trapped, and the corresponding data address, as
2447 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2448 registers meanwhile, we have the cached data we can rely on. */
2451 save_sigtrap (struct lwp_info
*lp
)
2453 struct cleanup
*old_chain
;
2455 if (linux_ops
->to_stopped_by_watchpoint
== NULL
)
2457 lp
->stopped_by_watchpoint
= 0;
2461 old_chain
= save_inferior_ptid ();
2462 inferior_ptid
= lp
->ptid
;
2464 lp
->stopped_by_watchpoint
= linux_ops
->to_stopped_by_watchpoint (linux_ops
);
2466 if (lp
->stopped_by_watchpoint
)
2468 if (linux_ops
->to_stopped_data_address
!= NULL
)
2469 lp
->stopped_data_address_p
=
2470 linux_ops
->to_stopped_data_address (¤t_target
,
2471 &lp
->stopped_data_address
);
2473 lp
->stopped_data_address_p
= 0;
2476 do_cleanups (old_chain
);
2479 /* See save_sigtrap. */
2482 linux_nat_stopped_by_watchpoint (struct target_ops
*ops
)
2484 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2486 gdb_assert (lp
!= NULL
);
2488 return lp
->stopped_by_watchpoint
;
2492 linux_nat_stopped_data_address (struct target_ops
*ops
, CORE_ADDR
*addr_p
)
2494 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2496 gdb_assert (lp
!= NULL
);
2498 *addr_p
= lp
->stopped_data_address
;
2500 return lp
->stopped_data_address_p
;
2503 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2506 sigtrap_is_event (int status
)
2508 return WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
;
2511 /* SIGTRAP-like events recognizer. */
2513 static int (*linux_nat_status_is_event
) (int status
) = sigtrap_is_event
;
2515 /* Check for SIGTRAP-like events in LP. */
2518 linux_nat_lp_status_is_event (struct lwp_info
*lp
)
2520 /* We check for lp->waitstatus in addition to lp->status, because we can
2521 have pending process exits recorded in lp->status
2522 and W_EXITCODE(0,0) == 0. We should probably have an additional
2523 lp->status_p flag. */
2525 return (lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
2526 && linux_nat_status_is_event (lp
->status
));
2529 /* Set alternative SIGTRAP-like events recognizer. If
2530 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2534 linux_nat_set_status_is_event (struct target_ops
*t
,
2535 int (*status_is_event
) (int status
))
2537 linux_nat_status_is_event
= status_is_event
;
2540 /* Wait until LP is stopped. */
2543 stop_wait_callback (struct lwp_info
*lp
, void *data
)
2545 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
2547 /* If this is a vfork parent, bail out, it is not going to report
2548 any SIGSTOP until the vfork is done with. */
2549 if (inf
->vfork_child
!= NULL
)
2556 status
= wait_lwp (lp
);
2560 if (lp
->ignore_sigint
&& WIFSTOPPED (status
)
2561 && WSTOPSIG (status
) == SIGINT
)
2563 lp
->ignore_sigint
= 0;
2566 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
2567 if (debug_linux_nat
)
2568 fprintf_unfiltered (gdb_stdlog
,
2569 "PTRACE_CONT %s, 0, 0 (%s) "
2570 "(discarding SIGINT)\n",
2571 target_pid_to_str (lp
->ptid
),
2572 errno
? safe_strerror (errno
) : "OK");
2574 return stop_wait_callback (lp
, NULL
);
2577 maybe_clear_ignore_sigint (lp
);
2579 if (WSTOPSIG (status
) != SIGSTOP
)
2581 /* The thread was stopped with a signal other than SIGSTOP. */
2585 if (debug_linux_nat
)
2586 fprintf_unfiltered (gdb_stdlog
,
2587 "SWC: Pending event %s in %s\n",
2588 status_to_str ((int) status
),
2589 target_pid_to_str (lp
->ptid
));
2591 /* Save the sigtrap event. */
2592 lp
->status
= status
;
2593 gdb_assert (!lp
->stopped
);
2594 gdb_assert (lp
->signalled
);
2599 /* We caught the SIGSTOP that we intended to catch, so
2600 there's no SIGSTOP pending. */
2602 if (debug_linux_nat
)
2603 fprintf_unfiltered (gdb_stdlog
,
2604 "SWC: Delayed SIGSTOP caught for %s.\n",
2605 target_pid_to_str (lp
->ptid
));
2609 /* Reset SIGNALLED only after the stop_wait_callback call
2610 above as it does gdb_assert on SIGNALLED. */
2618 /* Return non-zero if LP has a wait status pending. */
2621 status_callback (struct lwp_info
*lp
, void *data
)
2623 /* Only report a pending wait status if we pretend that this has
2624 indeed been resumed. */
2628 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
2630 /* A ptrace event, like PTRACE_FORK|VFORK|EXEC, syscall event,
2631 or a pending process exit. Note that `W_EXITCODE(0,0) ==
2632 0', so a clean process exit can not be stored pending in
2633 lp->status, it is indistinguishable from
2634 no-pending-status. */
2638 if (lp
->status
!= 0)
2644 /* Return non-zero if LP isn't stopped. */
2647 running_callback (struct lwp_info
*lp
, void *data
)
2649 return (!lp
->stopped
2650 || ((lp
->status
!= 0
2651 || lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
2655 /* Count the LWP's that have had events. */
2658 count_events_callback (struct lwp_info
*lp
, void *data
)
2662 gdb_assert (count
!= NULL
);
2664 /* Count only resumed LWPs that have a SIGTRAP event pending. */
2665 if (lp
->resumed
&& linux_nat_lp_status_is_event (lp
))
2671 /* Select the LWP (if any) that is currently being single-stepped. */
2674 select_singlestep_lwp_callback (struct lwp_info
*lp
, void *data
)
2676 if (lp
->last_resume_kind
== resume_step
2683 /* Select the Nth LWP that has had a SIGTRAP event. */
2686 select_event_lwp_callback (struct lwp_info
*lp
, void *data
)
2688 int *selector
= data
;
2690 gdb_assert (selector
!= NULL
);
2692 /* Select only resumed LWPs that have a SIGTRAP event pending. */
2693 if (lp
->resumed
&& linux_nat_lp_status_is_event (lp
))
2694 if ((*selector
)-- == 0)
2701 cancel_breakpoint (struct lwp_info
*lp
)
2703 /* Arrange for a breakpoint to be hit again later. We don't keep
2704 the SIGTRAP status and don't forward the SIGTRAP signal to the
2705 LWP. We will handle the current event, eventually we will resume
2706 this LWP, and this breakpoint will trap again.
2708 If we do not do this, then we run the risk that the user will
2709 delete or disable the breakpoint, but the LWP will have already
2712 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
2713 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
2716 pc
= regcache_read_pc (regcache
) - target_decr_pc_after_break (gdbarch
);
2717 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
2719 if (debug_linux_nat
)
2720 fprintf_unfiltered (gdb_stdlog
,
2721 "CB: Push back breakpoint for %s\n",
2722 target_pid_to_str (lp
->ptid
));
2724 /* Back up the PC if necessary. */
2725 if (target_decr_pc_after_break (gdbarch
))
2726 regcache_write_pc (regcache
, pc
);
2734 cancel_breakpoints_callback (struct lwp_info
*lp
, void *data
)
2736 struct lwp_info
*event_lp
= data
;
2738 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
2742 /* If a LWP other than the LWP that we're reporting an event for has
2743 hit a GDB breakpoint (as opposed to some random trap signal),
2744 then just arrange for it to hit it again later. We don't keep
2745 the SIGTRAP status and don't forward the SIGTRAP signal to the
2746 LWP. We will handle the current event, eventually we will resume
2747 all LWPs, and this one will get its breakpoint trap again.
2749 If we do not do this, then we run the risk that the user will
2750 delete or disable the breakpoint, but the LWP will have already
2753 if (linux_nat_lp_status_is_event (lp
)
2754 && cancel_breakpoint (lp
))
2755 /* Throw away the SIGTRAP. */
2761 /* Select one LWP out of those that have events pending. */
2764 select_event_lwp (ptid_t filter
, struct lwp_info
**orig_lp
, int *status
)
2767 int random_selector
;
2768 struct lwp_info
*event_lp
;
2770 /* Record the wait status for the original LWP. */
2771 (*orig_lp
)->status
= *status
;
2773 /* Give preference to any LWP that is being single-stepped. */
2774 event_lp
= iterate_over_lwps (filter
,
2775 select_singlestep_lwp_callback
, NULL
);
2776 if (event_lp
!= NULL
)
2778 if (debug_linux_nat
)
2779 fprintf_unfiltered (gdb_stdlog
,
2780 "SEL: Select single-step %s\n",
2781 target_pid_to_str (event_lp
->ptid
));
2785 /* No single-stepping LWP. Select one at random, out of those
2786 which have had SIGTRAP events. */
2788 /* First see how many SIGTRAP events we have. */
2789 iterate_over_lwps (filter
, count_events_callback
, &num_events
);
2791 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
2792 random_selector
= (int)
2793 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
2795 if (debug_linux_nat
&& num_events
> 1)
2796 fprintf_unfiltered (gdb_stdlog
,
2797 "SEL: Found %d SIGTRAP events, selecting #%d\n",
2798 num_events
, random_selector
);
2800 event_lp
= iterate_over_lwps (filter
,
2801 select_event_lwp_callback
,
2805 if (event_lp
!= NULL
)
2807 /* Switch the event LWP. */
2808 *orig_lp
= event_lp
;
2809 *status
= event_lp
->status
;
2812 /* Flush the wait status for the event LWP. */
2813 (*orig_lp
)->status
= 0;
2816 /* Return non-zero if LP has been resumed. */
2819 resumed_callback (struct lwp_info
*lp
, void *data
)
2824 /* Stop an active thread, verify it still exists, then resume it. If
2825 the thread ends up with a pending status, then it is not resumed,
2826 and *DATA (really a pointer to int), is set. */
2829 stop_and_resume_callback (struct lwp_info
*lp
, void *data
)
2831 int *new_pending_p
= data
;
2835 ptid_t ptid
= lp
->ptid
;
2837 stop_callback (lp
, NULL
);
2838 stop_wait_callback (lp
, NULL
);
2840 /* Resume if the lwp still exists, and the core wanted it
2842 lp
= find_lwp_pid (ptid
);
2845 if (lp
->last_resume_kind
== resume_stop
2848 /* The core wanted the LWP to stop. Even if it stopped
2849 cleanly (with SIGSTOP), leave the event pending. */
2850 if (debug_linux_nat
)
2851 fprintf_unfiltered (gdb_stdlog
,
2852 "SARC: core wanted LWP %ld stopped "
2853 "(leaving SIGSTOP pending)\n",
2854 ptid_get_lwp (lp
->ptid
));
2855 lp
->status
= W_STOPCODE (SIGSTOP
);
2858 if (lp
->status
== 0)
2860 if (debug_linux_nat
)
2861 fprintf_unfiltered (gdb_stdlog
,
2862 "SARC: re-resuming LWP %ld\n",
2863 ptid_get_lwp (lp
->ptid
));
2864 resume_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
2868 if (debug_linux_nat
)
2869 fprintf_unfiltered (gdb_stdlog
,
2870 "SARC: not re-resuming LWP %ld "
2872 ptid_get_lwp (lp
->ptid
));
2881 /* Check if we should go on and pass this event to common code.
2882 Return the affected lwp if we are, or NULL otherwise. If we stop
2883 all lwps temporarily, we may end up with new pending events in some
2884 other lwp. In that case set *NEW_PENDING_P to true. */
2886 static struct lwp_info
*
2887 linux_nat_filter_event (int lwpid
, int status
, int *new_pending_p
)
2889 struct lwp_info
*lp
;
2893 lp
= find_lwp_pid (pid_to_ptid (lwpid
));
2895 /* Check for stop events reported by a process we didn't already
2896 know about - anything not already in our LWP list.
2898 If we're expecting to receive stopped processes after
2899 fork, vfork, and clone events, then we'll just add the
2900 new one to our list and go back to waiting for the event
2901 to be reported - the stopped process might be returned
2902 from waitpid before or after the event is.
2904 But note the case of a non-leader thread exec'ing after the
2905 leader having exited, and gone from our lists. The non-leader
2906 thread changes its tid to the tgid. */
2908 if (WIFSTOPPED (status
) && lp
== NULL
2909 && (WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 == PTRACE_EVENT_EXEC
))
2911 /* A multi-thread exec after we had seen the leader exiting. */
2912 if (debug_linux_nat
)
2913 fprintf_unfiltered (gdb_stdlog
,
2914 "LLW: Re-adding thread group leader LWP %d.\n",
2917 lp
= add_lwp (ptid_build (lwpid
, lwpid
, 0));
2920 add_thread (lp
->ptid
);
2923 if (WIFSTOPPED (status
) && !lp
)
2925 add_to_pid_list (&stopped_pids
, lwpid
, status
);
2929 /* Make sure we don't report an event for the exit of an LWP not in
2930 our list, i.e. not part of the current process. This can happen
2931 if we detach from a program we originally forked and then it
2933 if (!WIFSTOPPED (status
) && !lp
)
2936 /* Handle GNU/Linux's syscall SIGTRAPs. */
2937 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2939 /* No longer need the sysgood bit. The ptrace event ends up
2940 recorded in lp->waitstatus if we care for it. We can carry
2941 on handling the event like a regular SIGTRAP from here
2943 status
= W_STOPCODE (SIGTRAP
);
2944 if (linux_handle_syscall_trap (lp
, 0))
2948 /* Handle GNU/Linux's extended waitstatus for trace events. */
2949 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 != 0)
2951 if (debug_linux_nat
)
2952 fprintf_unfiltered (gdb_stdlog
,
2953 "LLW: Handling extended status 0x%06x\n",
2955 if (linux_handle_extended_wait (lp
, status
, 0))
2959 if (linux_nat_status_is_event (status
))
2962 /* Check if the thread has exited. */
2963 if ((WIFEXITED (status
) || WIFSIGNALED (status
))
2964 && num_lwps (ptid_get_pid (lp
->ptid
)) > 1)
2966 /* If this is the main thread, we must stop all threads and verify
2967 if they are still alive. This is because in the nptl thread model
2968 on Linux 2.4, there is no signal issued for exiting LWPs
2969 other than the main thread. We only get the main thread exit
2970 signal once all child threads have already exited. If we
2971 stop all the threads and use the stop_wait_callback to check
2972 if they have exited we can determine whether this signal
2973 should be ignored or whether it means the end of the debugged
2974 application, regardless of which threading model is being
2976 if (ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
))
2979 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp
->ptid
)),
2980 stop_and_resume_callback
, new_pending_p
);
2983 if (debug_linux_nat
)
2984 fprintf_unfiltered (gdb_stdlog
,
2985 "LLW: %s exited.\n",
2986 target_pid_to_str (lp
->ptid
));
2988 if (num_lwps (ptid_get_pid (lp
->ptid
)) > 1)
2990 /* If there is at least one more LWP, then the exit signal
2991 was not the end of the debugged application and should be
2998 /* Check if the current LWP has previously exited. In the nptl
2999 thread model, LWPs other than the main thread do not issue
3000 signals when they exit so we must check whenever the thread has
3001 stopped. A similar check is made in stop_wait_callback(). */
3002 if (num_lwps (ptid_get_pid (lp
->ptid
)) > 1 && !linux_thread_alive (lp
->ptid
))
3004 ptid_t ptid
= pid_to_ptid (ptid_get_pid (lp
->ptid
));
3006 if (debug_linux_nat
)
3007 fprintf_unfiltered (gdb_stdlog
,
3008 "LLW: %s exited.\n",
3009 target_pid_to_str (lp
->ptid
));
3013 /* Make sure there is at least one thread running. */
3014 gdb_assert (iterate_over_lwps (ptid
, running_callback
, NULL
));
3016 /* Discard the event. */
3020 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3021 an attempt to stop an LWP. */
3023 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGSTOP
)
3025 if (debug_linux_nat
)
3026 fprintf_unfiltered (gdb_stdlog
,
3027 "LLW: Delayed SIGSTOP caught for %s.\n",
3028 target_pid_to_str (lp
->ptid
));
3032 if (lp
->last_resume_kind
!= resume_stop
)
3034 /* This is a delayed SIGSTOP. */
3036 registers_changed ();
3038 if (linux_nat_prepare_to_resume
!= NULL
)
3039 linux_nat_prepare_to_resume (lp
);
3040 linux_ops
->to_resume (linux_ops
,
3041 pid_to_ptid (ptid_get_lwp (lp
->ptid
)),
3042 lp
->step
, GDB_SIGNAL_0
);
3043 if (debug_linux_nat
)
3044 fprintf_unfiltered (gdb_stdlog
,
3045 "LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
3047 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3048 target_pid_to_str (lp
->ptid
));
3051 gdb_assert (lp
->resumed
);
3053 /* Discard the event. */
3058 /* Make sure we don't report a SIGINT that we have already displayed
3059 for another thread. */
3060 if (lp
->ignore_sigint
3061 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGINT
)
3063 if (debug_linux_nat
)
3064 fprintf_unfiltered (gdb_stdlog
,
3065 "LLW: Delayed SIGINT caught for %s.\n",
3066 target_pid_to_str (lp
->ptid
));
3068 /* This is a delayed SIGINT. */
3069 lp
->ignore_sigint
= 0;
3071 registers_changed ();
3072 if (linux_nat_prepare_to_resume
!= NULL
)
3073 linux_nat_prepare_to_resume (lp
);
3074 linux_ops
->to_resume (linux_ops
, pid_to_ptid (ptid_get_lwp (lp
->ptid
)),
3075 lp
->step
, GDB_SIGNAL_0
);
3076 if (debug_linux_nat
)
3077 fprintf_unfiltered (gdb_stdlog
,
3078 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3080 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3081 target_pid_to_str (lp
->ptid
));
3084 gdb_assert (lp
->resumed
);
3086 /* Discard the event. */
3090 /* An interesting event. */
3092 lp
->status
= status
;
3096 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3097 their exits until all other threads in the group have exited. */
3100 check_zombie_leaders (void)
3102 struct inferior
*inf
;
3106 struct lwp_info
*leader_lp
;
3111 leader_lp
= find_lwp_pid (pid_to_ptid (inf
->pid
));
3112 if (leader_lp
!= NULL
3113 /* Check if there are other threads in the group, as we may
3114 have raced with the inferior simply exiting. */
3115 && num_lwps (inf
->pid
) > 1
3116 && linux_proc_pid_is_zombie (inf
->pid
))
3118 if (debug_linux_nat
)
3119 fprintf_unfiltered (gdb_stdlog
,
3120 "CZL: Thread group leader %d zombie "
3121 "(it exited, or another thread execd).\n",
3124 /* A leader zombie can mean one of two things:
3126 - It exited, and there's an exit status pending
3127 available, or only the leader exited (not the whole
3128 program). In the latter case, we can't waitpid the
3129 leader's exit status until all other threads are gone.
3131 - There are 3 or more threads in the group, and a thread
3132 other than the leader exec'd. On an exec, the Linux
3133 kernel destroys all other threads (except the execing
3134 one) in the thread group, and resets the execing thread's
3135 tid to the tgid. No exit notification is sent for the
3136 execing thread -- from the ptracer's perspective, it
3137 appears as though the execing thread just vanishes.
3138 Until we reap all other threads except the leader and the
3139 execing thread, the leader will be zombie, and the
3140 execing thread will be in `D (disc sleep)'. As soon as
3141 all other threads are reaped, the execing thread changes
3142 it's tid to the tgid, and the previous (zombie) leader
3143 vanishes, giving place to the "new" leader. We could try
3144 distinguishing the exit and exec cases, by waiting once
3145 more, and seeing if something comes out, but it doesn't
3146 sound useful. The previous leader _does_ go away, and
3147 we'll re-add the new one once we see the exec event
3148 (which is just the same as what would happen if the
3149 previous leader did exit voluntarily before some other
3152 if (debug_linux_nat
)
3153 fprintf_unfiltered (gdb_stdlog
,
3154 "CZL: Thread group leader %d vanished.\n",
3156 exit_lwp (leader_lp
);
3162 linux_nat_wait_1 (struct target_ops
*ops
,
3163 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3166 static sigset_t prev_mask
;
3167 enum resume_kind last_resume_kind
;
3168 struct lwp_info
*lp
;
3171 if (debug_linux_nat
)
3172 fprintf_unfiltered (gdb_stdlog
, "LLW: enter\n");
3174 /* The first time we get here after starting a new inferior, we may
3175 not have added it to the LWP list yet - this is the earliest
3176 moment at which we know its PID. */
3177 if (ptid_is_pid (inferior_ptid
))
3179 /* Upgrade the main thread's ptid. */
3180 thread_change_ptid (inferior_ptid
,
3181 ptid_build (ptid_get_pid (inferior_ptid
),
3182 ptid_get_pid (inferior_ptid
), 0));
3184 lp
= add_initial_lwp (inferior_ptid
);
3188 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3189 block_child_signals (&prev_mask
);
3195 /* First check if there is a LWP with a wait status pending. */
3196 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3198 /* Any LWP in the PTID group that's been resumed will do. */
3199 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3202 if (debug_linux_nat
&& lp
->status
)
3203 fprintf_unfiltered (gdb_stdlog
,
3204 "LLW: Using pending wait status %s for %s.\n",
3205 status_to_str (lp
->status
),
3206 target_pid_to_str (lp
->ptid
));
3209 else if (ptid_lwp_p (ptid
))
3211 if (debug_linux_nat
)
3212 fprintf_unfiltered (gdb_stdlog
,
3213 "LLW: Waiting for specific LWP %s.\n",
3214 target_pid_to_str (ptid
));
3216 /* We have a specific LWP to check. */
3217 lp
= find_lwp_pid (ptid
);
3220 if (debug_linux_nat
&& lp
->status
)
3221 fprintf_unfiltered (gdb_stdlog
,
3222 "LLW: Using pending wait status %s for %s.\n",
3223 status_to_str (lp
->status
),
3224 target_pid_to_str (lp
->ptid
));
3226 /* We check for lp->waitstatus in addition to lp->status,
3227 because we can have pending process exits recorded in
3228 lp->status and W_EXITCODE(0,0) == 0. We should probably have
3229 an additional lp->status_p flag. */
3230 if (lp
->status
== 0 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
3234 if (!target_can_async_p ())
3236 /* Causes SIGINT to be passed on to the attached process. */
3240 /* But if we don't find a pending event, we'll have to wait. */
3246 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3249 - If the thread group leader exits while other threads in the
3250 thread group still exist, waitpid(TGID, ...) hangs. That
3251 waitpid won't return an exit status until the other threads
3252 in the group are reapped.
3254 - When a non-leader thread execs, that thread just vanishes
3255 without reporting an exit (so we'd hang if we waited for it
3256 explicitly in that case). The exec event is reported to
3260 lwpid
= my_waitpid (-1, &status
, __WCLONE
| WNOHANG
);
3261 if (lwpid
== 0 || (lwpid
== -1 && errno
== ECHILD
))
3262 lwpid
= my_waitpid (-1, &status
, WNOHANG
);
3264 if (debug_linux_nat
)
3265 fprintf_unfiltered (gdb_stdlog
,
3266 "LNW: waitpid(-1, ...) returned %d, %s\n",
3267 lwpid
, errno
? safe_strerror (errno
) : "ERRNO-OK");
3271 /* If this is true, then we paused LWPs momentarily, and may
3272 now have pending events to handle. */
3275 if (debug_linux_nat
)
3277 fprintf_unfiltered (gdb_stdlog
,
3278 "LLW: waitpid %ld received %s\n",
3279 (long) lwpid
, status_to_str (status
));
3282 lp
= linux_nat_filter_event (lwpid
, status
, &new_pending
);
3284 /* STATUS is now no longer valid, use LP->STATUS instead. */
3287 if (lp
&& !ptid_match (lp
->ptid
, ptid
))
3289 gdb_assert (lp
->resumed
);
3291 if (debug_linux_nat
)
3293 "LWP %ld got an event %06x, leaving pending.\n",
3294 ptid_get_lwp (lp
->ptid
), lp
->status
);
3296 if (WIFSTOPPED (lp
->status
))
3298 if (WSTOPSIG (lp
->status
) != SIGSTOP
)
3300 /* Cancel breakpoint hits. The breakpoint may
3301 be removed before we fetch events from this
3302 process to report to the core. It is best
3303 not to assume the moribund breakpoints
3304 heuristic always handles these cases --- it
3305 could be too many events go through to the
3306 core before this one is handled. All-stop
3307 always cancels breakpoint hits in all
3310 && linux_nat_lp_status_is_event (lp
)
3311 && cancel_breakpoint (lp
))
3313 /* Throw away the SIGTRAP. */
3316 if (debug_linux_nat
)
3318 "LLW: LWP %ld hit a breakpoint while"
3319 " waiting for another process;"
3321 ptid_get_lwp (lp
->ptid
));
3331 else if (WIFEXITED (lp
->status
) || WIFSIGNALED (lp
->status
))
3333 if (debug_linux_nat
)
3335 "Process %ld exited while stopping LWPs\n",
3336 ptid_get_lwp (lp
->ptid
));
3338 /* This was the last lwp in the process. Since
3339 events are serialized to GDB core, and we can't
3340 report this one right now, but GDB core and the
3341 other target layers will want to be notified
3342 about the exit code/signal, leave the status
3343 pending for the next time we're able to report
3346 /* Prevent trying to stop this thread again. We'll
3347 never try to resume it because it has a pending
3351 /* Dead LWP's aren't expected to reported a pending
3355 /* Store the pending event in the waitstatus as
3356 well, because W_EXITCODE(0,0) == 0. */
3357 store_waitstatus (&lp
->waitstatus
, lp
->status
);
3366 /* Some LWP now has a pending event. Go all the way
3367 back to check it. */
3373 /* We got an event to report to the core. */
3377 /* Retry until nothing comes out of waitpid. A single
3378 SIGCHLD can indicate more than one child stopped. */
3382 /* Check for zombie thread group leaders. Those can't be reaped
3383 until all other threads in the thread group are. */
3384 check_zombie_leaders ();
3386 /* If there are no resumed children left, bail. We'd be stuck
3387 forever in the sigsuspend call below otherwise. */
3388 if (iterate_over_lwps (ptid
, resumed_callback
, NULL
) == NULL
)
3390 if (debug_linux_nat
)
3391 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (no resumed LWP)\n");
3393 ourstatus
->kind
= TARGET_WAITKIND_NO_RESUMED
;
3395 if (!target_can_async_p ())
3396 clear_sigint_trap ();
3398 restore_child_signals_mask (&prev_mask
);
3399 return minus_one_ptid
;
3402 /* No interesting event to report to the core. */
3404 if (target_options
& TARGET_WNOHANG
)
3406 if (debug_linux_nat
)
3407 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (ignore)\n");
3409 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3410 restore_child_signals_mask (&prev_mask
);
3411 return minus_one_ptid
;
3414 /* We shouldn't end up here unless we want to try again. */
3415 gdb_assert (lp
== NULL
);
3417 /* Block until we get an event reported with SIGCHLD. */
3418 sigsuspend (&suspend_mask
);
3421 if (!target_can_async_p ())
3422 clear_sigint_trap ();
3426 status
= lp
->status
;
3429 /* Don't report signals that GDB isn't interested in, such as
3430 signals that are neither printed nor stopped upon. Stopping all
3431 threads can be a bit time-consuming so if we want decent
3432 performance with heavily multi-threaded programs, especially when
3433 they're using a high frequency timer, we'd better avoid it if we
3436 if (WIFSTOPPED (status
))
3438 enum gdb_signal signo
= gdb_signal_from_host (WSTOPSIG (status
));
3440 /* When using hardware single-step, we need to report every signal.
3441 Otherwise, signals in pass_mask may be short-circuited. */
3443 && WSTOPSIG (status
) && sigismember (&pass_mask
, WSTOPSIG (status
)))
3445 /* FIMXE: kettenis/2001-06-06: Should we resume all threads
3446 here? It is not clear we should. GDB may not expect
3447 other threads to run. On the other hand, not resuming
3448 newly attached threads may cause an unwanted delay in
3449 getting them running. */
3450 registers_changed ();
3451 if (linux_nat_prepare_to_resume
!= NULL
)
3452 linux_nat_prepare_to_resume (lp
);
3453 linux_ops
->to_resume (linux_ops
,
3454 pid_to_ptid (ptid_get_lwp (lp
->ptid
)),
3456 if (debug_linux_nat
)
3457 fprintf_unfiltered (gdb_stdlog
,
3458 "LLW: %s %s, %s (preempt 'handle')\n",
3460 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3461 target_pid_to_str (lp
->ptid
),
3462 (signo
!= GDB_SIGNAL_0
3463 ? strsignal (gdb_signal_to_host (signo
))
3471 /* Only do the below in all-stop, as we currently use SIGINT
3472 to implement target_stop (see linux_nat_stop) in
3474 if (signo
== GDB_SIGNAL_INT
&& signal_pass_state (signo
) == 0)
3476 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3477 forwarded to the entire process group, that is, all LWPs
3478 will receive it - unless they're using CLONE_THREAD to
3479 share signals. Since we only want to report it once, we
3480 mark it as ignored for all LWPs except this one. */
3481 iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid
)),
3482 set_ignore_sigint
, NULL
);
3483 lp
->ignore_sigint
= 0;
3486 maybe_clear_ignore_sigint (lp
);
3490 /* This LWP is stopped now. */
3493 if (debug_linux_nat
)
3494 fprintf_unfiltered (gdb_stdlog
, "LLW: Candidate event %s in %s.\n",
3495 status_to_str (status
), target_pid_to_str (lp
->ptid
));
3499 /* Now stop all other LWP's ... */
3500 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
3502 /* ... and wait until all of them have reported back that
3503 they're no longer running. */
3504 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
3506 /* If we're not waiting for a specific LWP, choose an event LWP
3507 from among those that have had events. Giving equal priority
3508 to all LWPs that have had events helps prevent
3510 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3511 select_event_lwp (ptid
, &lp
, &status
);
3513 /* Now that we've selected our final event LWP, cancel any
3514 breakpoints in other LWPs that have hit a GDB breakpoint.
3515 See the comment in cancel_breakpoints_callback to find out
3517 iterate_over_lwps (minus_one_ptid
, cancel_breakpoints_callback
, lp
);
3519 /* We'll need this to determine whether to report a SIGSTOP as
3520 TARGET_WAITKIND_0. Need to take a copy because
3521 resume_clear_callback clears it. */
3522 last_resume_kind
= lp
->last_resume_kind
;
3524 /* In all-stop, from the core's perspective, all LWPs are now
3525 stopped until a new resume action is sent over. */
3526 iterate_over_lwps (minus_one_ptid
, resume_clear_callback
, NULL
);
3531 last_resume_kind
= lp
->last_resume_kind
;
3532 resume_clear_callback (lp
, NULL
);
3535 if (linux_nat_status_is_event (status
))
3537 if (debug_linux_nat
)
3538 fprintf_unfiltered (gdb_stdlog
,
3539 "LLW: trap ptid is %s.\n",
3540 target_pid_to_str (lp
->ptid
));
3543 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3545 *ourstatus
= lp
->waitstatus
;
3546 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3549 store_waitstatus (ourstatus
, status
);
3551 if (debug_linux_nat
)
3552 fprintf_unfiltered (gdb_stdlog
, "LLW: exit\n");
3554 restore_child_signals_mask (&prev_mask
);
3556 if (last_resume_kind
== resume_stop
3557 && ourstatus
->kind
== TARGET_WAITKIND_STOPPED
3558 && WSTOPSIG (status
) == SIGSTOP
)
3560 /* A thread that has been requested to stop by GDB with
3561 target_stop, and it stopped cleanly, so report as SIG0. The
3562 use of SIGSTOP is an implementation detail. */
3563 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3566 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
3567 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
3570 lp
->core
= linux_common_core_of_thread (lp
->ptid
);
3575 /* Resume LWPs that are currently stopped without any pending status
3576 to report, but are resumed from the core's perspective. */
3579 resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
)
3581 ptid_t
*wait_ptid_p
= data
;
3586 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
3588 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3589 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3590 CORE_ADDR pc
= regcache_read_pc (regcache
);
3592 gdb_assert (is_executing (lp
->ptid
));
3594 /* Don't bother if there's a breakpoint at PC that we'd hit
3595 immediately, and we're not waiting for this LWP. */
3596 if (!ptid_match (lp
->ptid
, *wait_ptid_p
))
3598 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
3602 if (debug_linux_nat
)
3603 fprintf_unfiltered (gdb_stdlog
,
3604 "RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n",
3605 target_pid_to_str (lp
->ptid
),
3606 paddress (gdbarch
, pc
),
3609 registers_changed ();
3610 if (linux_nat_prepare_to_resume
!= NULL
)
3611 linux_nat_prepare_to_resume (lp
);
3612 linux_ops
->to_resume (linux_ops
, pid_to_ptid (ptid_get_lwp (lp
->ptid
)),
3613 lp
->step
, GDB_SIGNAL_0
);
3615 lp
->stopped_by_watchpoint
= 0;
3622 linux_nat_wait (struct target_ops
*ops
,
3623 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3628 if (debug_linux_nat
)
3630 char *options_string
;
3632 options_string
= target_options_to_string (target_options
);
3633 fprintf_unfiltered (gdb_stdlog
,
3634 "linux_nat_wait: [%s], [%s]\n",
3635 target_pid_to_str (ptid
),
3637 xfree (options_string
);
3640 /* Flush the async file first. */
3641 if (target_can_async_p ())
3642 async_file_flush ();
3644 /* Resume LWPs that are currently stopped without any pending status
3645 to report, but are resumed from the core's perspective. LWPs get
3646 in this state if we find them stopping at a time we're not
3647 interested in reporting the event (target_wait on a
3648 specific_process, for example, see linux_nat_wait_1), and
3649 meanwhile the event became uninteresting. Don't bother resuming
3650 LWPs we're not going to wait for if they'd stop immediately. */
3652 iterate_over_lwps (minus_one_ptid
, resume_stopped_resumed_lwps
, &ptid
);
3654 event_ptid
= linux_nat_wait_1 (ops
, ptid
, ourstatus
, target_options
);
3656 /* If we requested any event, and something came out, assume there
3657 may be more. If we requested a specific lwp or process, also
3658 assume there may be more. */
3659 if (target_can_async_p ()
3660 && ((ourstatus
->kind
!= TARGET_WAITKIND_IGNORE
3661 && ourstatus
->kind
!= TARGET_WAITKIND_NO_RESUMED
)
3662 || !ptid_equal (ptid
, minus_one_ptid
)))
3665 /* Get ready for the next event. */
3666 if (target_can_async_p ())
3667 target_async (inferior_event_handler
, 0);
3673 kill_callback (struct lwp_info
*lp
, void *data
)
3675 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3678 kill (ptid_get_lwp (lp
->ptid
), SIGKILL
);
3679 if (debug_linux_nat
)
3680 fprintf_unfiltered (gdb_stdlog
,
3681 "KC: kill (SIGKILL) %s, 0, 0 (%s)\n",
3682 target_pid_to_str (lp
->ptid
),
3683 errno
? safe_strerror (errno
) : "OK");
3685 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3688 ptrace (PTRACE_KILL
, ptid_get_lwp (lp
->ptid
), 0, 0);
3689 if (debug_linux_nat
)
3690 fprintf_unfiltered (gdb_stdlog
,
3691 "KC: PTRACE_KILL %s, 0, 0 (%s)\n",
3692 target_pid_to_str (lp
->ptid
),
3693 errno
? safe_strerror (errno
) : "OK");
3699 kill_wait_callback (struct lwp_info
*lp
, void *data
)
3703 /* We must make sure that there are no pending events (delayed
3704 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3705 program doesn't interfere with any following debugging session. */
3707 /* For cloned processes we must check both with __WCLONE and
3708 without, since the exit status of a cloned process isn't reported
3714 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), NULL
, __WCLONE
);
3715 if (pid
!= (pid_t
) -1)
3717 if (debug_linux_nat
)
3718 fprintf_unfiltered (gdb_stdlog
,
3719 "KWC: wait %s received unknown.\n",
3720 target_pid_to_str (lp
->ptid
));
3721 /* The Linux kernel sometimes fails to kill a thread
3722 completely after PTRACE_KILL; that goes from the stop
3723 point in do_fork out to the one in
3724 get_signal_to_deliever and waits again. So kill it
3726 kill_callback (lp
, NULL
);
3729 while (pid
== ptid_get_lwp (lp
->ptid
));
3731 gdb_assert (pid
== -1 && errno
== ECHILD
);
3736 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), NULL
, 0);
3737 if (pid
!= (pid_t
) -1)
3739 if (debug_linux_nat
)
3740 fprintf_unfiltered (gdb_stdlog
,
3741 "KWC: wait %s received unk.\n",
3742 target_pid_to_str (lp
->ptid
));
3743 /* See the call to kill_callback above. */
3744 kill_callback (lp
, NULL
);
3747 while (pid
== ptid_get_lwp (lp
->ptid
));
3749 gdb_assert (pid
== -1 && errno
== ECHILD
);
3754 linux_nat_kill (struct target_ops
*ops
)
3756 struct target_waitstatus last
;
3760 /* If we're stopped while forking and we haven't followed yet,
3761 kill the other task. We need to do this first because the
3762 parent will be sleeping if this is a vfork. */
3764 get_last_target_status (&last_ptid
, &last
);
3766 if (last
.kind
== TARGET_WAITKIND_FORKED
3767 || last
.kind
== TARGET_WAITKIND_VFORKED
)
3769 ptrace (PT_KILL
, ptid_get_pid (last
.value
.related_pid
), 0, 0);
3772 /* Let the arch-specific native code know this process is
3774 linux_nat_forget_process (ptid_get_pid (last
.value
.related_pid
));
3777 if (forks_exist_p ())
3778 linux_fork_killall ();
3781 ptid_t ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
3783 /* Stop all threads before killing them, since ptrace requires
3784 that the thread is stopped to sucessfully PTRACE_KILL. */
3785 iterate_over_lwps (ptid
, stop_callback
, NULL
);
3786 /* ... and wait until all of them have reported back that
3787 they're no longer running. */
3788 iterate_over_lwps (ptid
, stop_wait_callback
, NULL
);
3790 /* Kill all LWP's ... */
3791 iterate_over_lwps (ptid
, kill_callback
, NULL
);
3793 /* ... and wait until we've flushed all events. */
3794 iterate_over_lwps (ptid
, kill_wait_callback
, NULL
);
3797 target_mourn_inferior ();
3801 linux_nat_mourn_inferior (struct target_ops
*ops
)
3803 int pid
= ptid_get_pid (inferior_ptid
);
3805 purge_lwp_list (pid
);
3807 if (! forks_exist_p ())
3808 /* Normal case, no other forks available. */
3809 linux_ops
->to_mourn_inferior (ops
);
3811 /* Multi-fork case. The current inferior_ptid has exited, but
3812 there are other viable forks to debug. Delete the exiting
3813 one and context-switch to the first available. */
3814 linux_fork_mourn_inferior ();
3816 /* Let the arch-specific native code know this process is gone. */
3817 linux_nat_forget_process (pid
);
3820 /* Convert a native/host siginfo object, into/from the siginfo in the
3821 layout of the inferiors' architecture. */
3824 siginfo_fixup (siginfo_t
*siginfo
, gdb_byte
*inf_siginfo
, int direction
)
3828 if (linux_nat_siginfo_fixup
!= NULL
)
3829 done
= linux_nat_siginfo_fixup (siginfo
, inf_siginfo
, direction
);
3831 /* If there was no callback, or the callback didn't do anything,
3832 then just do a straight memcpy. */
3836 memcpy (siginfo
, inf_siginfo
, sizeof (siginfo_t
));
3838 memcpy (inf_siginfo
, siginfo
, sizeof (siginfo_t
));
3842 static enum target_xfer_status
3843 linux_xfer_siginfo (struct target_ops
*ops
, enum target_object object
,
3844 const char *annex
, gdb_byte
*readbuf
,
3845 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
3846 ULONGEST
*xfered_len
)
3850 gdb_byte inf_siginfo
[sizeof (siginfo_t
)];
3852 gdb_assert (object
== TARGET_OBJECT_SIGNAL_INFO
);
3853 gdb_assert (readbuf
|| writebuf
);
3855 pid
= ptid_get_lwp (inferior_ptid
);
3857 pid
= ptid_get_pid (inferior_ptid
);
3859 if (offset
> sizeof (siginfo
))
3860 return TARGET_XFER_E_IO
;
3863 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3865 return TARGET_XFER_E_IO
;
3867 /* When GDB is built as a 64-bit application, ptrace writes into
3868 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3869 inferior with a 64-bit GDB should look the same as debugging it
3870 with a 32-bit GDB, we need to convert it. GDB core always sees
3871 the converted layout, so any read/write will have to be done
3873 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
3875 if (offset
+ len
> sizeof (siginfo
))
3876 len
= sizeof (siginfo
) - offset
;
3878 if (readbuf
!= NULL
)
3879 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
3882 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
3884 /* Convert back to ptrace layout before flushing it out. */
3885 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
3888 ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3890 return TARGET_XFER_E_IO
;
3894 return TARGET_XFER_OK
;
3897 static enum target_xfer_status
3898 linux_nat_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3899 const char *annex
, gdb_byte
*readbuf
,
3900 const gdb_byte
*writebuf
,
3901 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
3903 struct cleanup
*old_chain
;
3904 enum target_xfer_status xfer
;
3906 if (object
== TARGET_OBJECT_SIGNAL_INFO
)
3907 return linux_xfer_siginfo (ops
, object
, annex
, readbuf
, writebuf
,
3908 offset
, len
, xfered_len
);
3910 /* The target is connected but no live inferior is selected. Pass
3911 this request down to a lower stratum (e.g., the executable
3913 if (object
== TARGET_OBJECT_MEMORY
&& ptid_equal (inferior_ptid
, null_ptid
))
3914 return TARGET_XFER_EOF
;
3916 old_chain
= save_inferior_ptid ();
3918 if (ptid_lwp_p (inferior_ptid
))
3919 inferior_ptid
= pid_to_ptid (ptid_get_lwp (inferior_ptid
));
3921 xfer
= linux_ops
->to_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
3922 offset
, len
, xfered_len
);
3924 do_cleanups (old_chain
);
3929 linux_thread_alive (ptid_t ptid
)
3933 gdb_assert (ptid_lwp_p (ptid
));
3935 /* Send signal 0 instead of anything ptrace, because ptracing a
3936 running thread errors out claiming that the thread doesn't
3938 err
= kill_lwp (ptid_get_lwp (ptid
), 0);
3940 if (debug_linux_nat
)
3941 fprintf_unfiltered (gdb_stdlog
,
3942 "LLTA: KILL(SIG0) %s (%s)\n",
3943 target_pid_to_str (ptid
),
3944 err
? safe_strerror (tmp_errno
) : "OK");
3953 linux_nat_thread_alive (struct target_ops
*ops
, ptid_t ptid
)
3955 return linux_thread_alive (ptid
);
3959 linux_nat_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
3961 static char buf
[64];
3963 if (ptid_lwp_p (ptid
)
3964 && (ptid_get_pid (ptid
) != ptid_get_lwp (ptid
)
3965 || num_lwps (ptid_get_pid (ptid
)) > 1))
3967 snprintf (buf
, sizeof (buf
), "LWP %ld", ptid_get_lwp (ptid
));
3971 return normal_pid_to_str (ptid
);
3975 linux_nat_thread_name (struct target_ops
*self
, struct thread_info
*thr
)
3977 int pid
= ptid_get_pid (thr
->ptid
);
3978 long lwp
= ptid_get_lwp (thr
->ptid
);
3979 #define FORMAT "/proc/%d/task/%ld/comm"
3980 char buf
[sizeof (FORMAT
) + 30];
3982 char *result
= NULL
;
3984 snprintf (buf
, sizeof (buf
), FORMAT
, pid
, lwp
);
3985 comm_file
= gdb_fopen_cloexec (buf
, "r");
3988 /* Not exported by the kernel, so we define it here. */
3990 static char line
[COMM_LEN
+ 1];
3992 if (fgets (line
, sizeof (line
), comm_file
))
3994 char *nl
= strchr (line
, '\n');
4011 /* Accepts an integer PID; Returns a string representing a file that
4012 can be opened to get the symbols for the child process. */
4015 linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
)
4017 static char buf
[PATH_MAX
];
4018 char name
[PATH_MAX
];
4020 xsnprintf (name
, PATH_MAX
, "/proc/%d/exe", pid
);
4021 memset (buf
, 0, PATH_MAX
);
4022 if (readlink (name
, buf
, PATH_MAX
- 1) <= 0)
4028 /* Records the thread's register state for the corefile note
4032 linux_nat_collect_thread_registers (const struct regcache
*regcache
,
4033 ptid_t ptid
, bfd
*obfd
,
4034 char *note_data
, int *note_size
,
4035 enum gdb_signal stop_signal
)
4037 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
4038 const struct regset
*regset
;
4040 gdb_gregset_t gregs
;
4041 gdb_fpregset_t fpregs
;
4043 core_regset_p
= gdbarch_regset_from_core_section_p (gdbarch
);
4046 && (regset
= gdbarch_regset_from_core_section (gdbarch
, ".reg",
4048 != NULL
&& regset
->collect_regset
!= NULL
)
4049 regset
->collect_regset (regset
, regcache
, -1, &gregs
, sizeof (gregs
));
4051 fill_gregset (regcache
, &gregs
, -1);
4053 note_data
= (char *) elfcore_write_prstatus
4054 (obfd
, note_data
, note_size
, ptid_get_lwp (ptid
),
4055 gdb_signal_to_host (stop_signal
), &gregs
);
4058 && (regset
= gdbarch_regset_from_core_section (gdbarch
, ".reg2",
4060 != NULL
&& regset
->collect_regset
!= NULL
)
4061 regset
->collect_regset (regset
, regcache
, -1, &fpregs
, sizeof (fpregs
));
4063 fill_fpregset (regcache
, &fpregs
, -1);
4065 note_data
= (char *) elfcore_write_prfpreg (obfd
, note_data
, note_size
,
4066 &fpregs
, sizeof (fpregs
));
4071 /* Fills the "to_make_corefile_note" target vector. Builds the note
4072 section for a corefile, and returns it in a malloc buffer. */
4075 linux_nat_make_corefile_notes (struct target_ops
*self
,
4076 bfd
*obfd
, int *note_size
)
4078 /* FIXME: uweigand/2011-10-06: Once all GNU/Linux architectures have been
4079 converted to gdbarch_core_regset_sections, this function can go away. */
4080 return linux_make_corefile_notes (target_gdbarch (), obfd
, note_size
,
4081 linux_nat_collect_thread_registers
);
4084 /* Implement the to_xfer_partial interface for memory reads using the /proc
4085 filesystem. Because we can use a single read() call for /proc, this
4086 can be much more efficient than banging away at PTRACE_PEEKTEXT,
4087 but it doesn't support writes. */
4089 static enum target_xfer_status
4090 linux_proc_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4091 const char *annex
, gdb_byte
*readbuf
,
4092 const gdb_byte
*writebuf
,
4093 ULONGEST offset
, LONGEST len
, ULONGEST
*xfered_len
)
4099 if (object
!= TARGET_OBJECT_MEMORY
|| !readbuf
)
4102 /* Don't bother for one word. */
4103 if (len
< 3 * sizeof (long))
4104 return TARGET_XFER_EOF
;
4106 /* We could keep this file open and cache it - possibly one per
4107 thread. That requires some juggling, but is even faster. */
4108 xsnprintf (filename
, sizeof filename
, "/proc/%d/mem",
4109 ptid_get_pid (inferior_ptid
));
4110 fd
= gdb_open_cloexec (filename
, O_RDONLY
| O_LARGEFILE
, 0);
4112 return TARGET_XFER_EOF
;
4114 /* If pread64 is available, use it. It's faster if the kernel
4115 supports it (only one syscall), and it's 64-bit safe even on
4116 32-bit platforms (for instance, SPARC debugging a SPARC64
4119 if (pread64 (fd
, readbuf
, len
, offset
) != len
)
4121 if (lseek (fd
, offset
, SEEK_SET
) == -1 || read (fd
, readbuf
, len
) != len
)
4130 return TARGET_XFER_EOF
;
4134 return TARGET_XFER_OK
;
4139 /* Enumerate spufs IDs for process PID. */
4141 spu_enumerate_spu_ids (int pid
, gdb_byte
*buf
, ULONGEST offset
, ULONGEST len
)
4143 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
4145 LONGEST written
= 0;
4148 struct dirent
*entry
;
4150 xsnprintf (path
, sizeof path
, "/proc/%d/fd", pid
);
4151 dir
= opendir (path
);
4156 while ((entry
= readdir (dir
)) != NULL
)
4162 fd
= atoi (entry
->d_name
);
4166 xsnprintf (path
, sizeof path
, "/proc/%d/fd/%d", pid
, fd
);
4167 if (stat (path
, &st
) != 0)
4169 if (!S_ISDIR (st
.st_mode
))
4172 if (statfs (path
, &stfs
) != 0)
4174 if (stfs
.f_type
!= SPUFS_MAGIC
)
4177 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4179 store_unsigned_integer (buf
+ pos
- offset
, 4, byte_order
, fd
);
4189 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4190 object type, using the /proc file system. */
4192 static enum target_xfer_status
4193 linux_proc_xfer_spu (struct target_ops
*ops
, enum target_object object
,
4194 const char *annex
, gdb_byte
*readbuf
,
4195 const gdb_byte
*writebuf
,
4196 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
4201 int pid
= ptid_get_pid (inferior_ptid
);
4206 return TARGET_XFER_E_IO
;
4209 LONGEST l
= spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4212 return TARGET_XFER_E_IO
;
4214 return TARGET_XFER_EOF
;
4217 *xfered_len
= (ULONGEST
) l
;
4218 return TARGET_XFER_OK
;
4223 xsnprintf (buf
, sizeof buf
, "/proc/%d/fd/%s", pid
, annex
);
4224 fd
= gdb_open_cloexec (buf
, writebuf
? O_WRONLY
: O_RDONLY
, 0);
4226 return TARGET_XFER_E_IO
;
4229 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4232 return TARGET_XFER_EOF
;
4236 ret
= write (fd
, writebuf
, (size_t) len
);
4238 ret
= read (fd
, readbuf
, (size_t) len
);
4243 return TARGET_XFER_E_IO
;
4245 return TARGET_XFER_EOF
;
4248 *xfered_len
= (ULONGEST
) ret
;
4249 return TARGET_XFER_OK
;
4254 /* Parse LINE as a signal set and add its set bits to SIGS. */
4257 add_line_to_sigset (const char *line
, sigset_t
*sigs
)
4259 int len
= strlen (line
) - 1;
4263 if (line
[len
] != '\n')
4264 error (_("Could not parse signal set: %s"), line
);
4272 if (*p
>= '0' && *p
<= '9')
4274 else if (*p
>= 'a' && *p
<= 'f')
4275 digit
= *p
- 'a' + 10;
4277 error (_("Could not parse signal set: %s"), line
);
4282 sigaddset (sigs
, signum
+ 1);
4284 sigaddset (sigs
, signum
+ 2);
4286 sigaddset (sigs
, signum
+ 3);
4288 sigaddset (sigs
, signum
+ 4);
4294 /* Find process PID's pending signals from /proc/pid/status and set
4298 linux_proc_pending_signals (int pid
, sigset_t
*pending
,
4299 sigset_t
*blocked
, sigset_t
*ignored
)
4302 char buffer
[PATH_MAX
], fname
[PATH_MAX
];
4303 struct cleanup
*cleanup
;
4305 sigemptyset (pending
);
4306 sigemptyset (blocked
);
4307 sigemptyset (ignored
);
4308 xsnprintf (fname
, sizeof fname
, "/proc/%d/status", pid
);
4309 procfile
= gdb_fopen_cloexec (fname
, "r");
4310 if (procfile
== NULL
)
4311 error (_("Could not open %s"), fname
);
4312 cleanup
= make_cleanup_fclose (procfile
);
4314 while (fgets (buffer
, PATH_MAX
, procfile
) != NULL
)
4316 /* Normal queued signals are on the SigPnd line in the status
4317 file. However, 2.6 kernels also have a "shared" pending
4318 queue for delivering signals to a thread group, so check for
4321 Unfortunately some Red Hat kernels include the shared pending
4322 queue but not the ShdPnd status field. */
4324 if (strncmp (buffer
, "SigPnd:\t", 8) == 0)
4325 add_line_to_sigset (buffer
+ 8, pending
);
4326 else if (strncmp (buffer
, "ShdPnd:\t", 8) == 0)
4327 add_line_to_sigset (buffer
+ 8, pending
);
4328 else if (strncmp (buffer
, "SigBlk:\t", 8) == 0)
4329 add_line_to_sigset (buffer
+ 8, blocked
);
4330 else if (strncmp (buffer
, "SigIgn:\t", 8) == 0)
4331 add_line_to_sigset (buffer
+ 8, ignored
);
4334 do_cleanups (cleanup
);
4337 static enum target_xfer_status
4338 linux_nat_xfer_osdata (struct target_ops
*ops
, enum target_object object
,
4339 const char *annex
, gdb_byte
*readbuf
,
4340 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4341 ULONGEST
*xfered_len
)
4343 gdb_assert (object
== TARGET_OBJECT_OSDATA
);
4345 *xfered_len
= linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
4346 if (*xfered_len
== 0)
4347 return TARGET_XFER_EOF
;
4349 return TARGET_XFER_OK
;
4352 static enum target_xfer_status
4353 linux_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4354 const char *annex
, gdb_byte
*readbuf
,
4355 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4356 ULONGEST
*xfered_len
)
4358 enum target_xfer_status xfer
;
4360 if (object
== TARGET_OBJECT_AUXV
)
4361 return memory_xfer_auxv (ops
, object
, annex
, readbuf
, writebuf
,
4362 offset
, len
, xfered_len
);
4364 if (object
== TARGET_OBJECT_OSDATA
)
4365 return linux_nat_xfer_osdata (ops
, object
, annex
, readbuf
, writebuf
,
4366 offset
, len
, xfered_len
);
4368 if (object
== TARGET_OBJECT_SPU
)
4369 return linux_proc_xfer_spu (ops
, object
, annex
, readbuf
, writebuf
,
4370 offset
, len
, xfered_len
);
4372 /* GDB calculates all the addresses in possibly larget width of the address.
4373 Address width needs to be masked before its final use - either by
4374 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4376 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4378 if (object
== TARGET_OBJECT_MEMORY
)
4380 int addr_bit
= gdbarch_addr_bit (target_gdbarch ());
4382 if (addr_bit
< (sizeof (ULONGEST
) * HOST_CHAR_BIT
))
4383 offset
&= ((ULONGEST
) 1 << addr_bit
) - 1;
4386 xfer
= linux_proc_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4387 offset
, len
, xfered_len
);
4388 if (xfer
!= TARGET_XFER_EOF
)
4391 return super_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4392 offset
, len
, xfered_len
);
4396 cleanup_target_stop (void *arg
)
4398 ptid_t
*ptid
= (ptid_t
*) arg
;
4400 gdb_assert (arg
!= NULL
);
4403 target_resume (*ptid
, 0, GDB_SIGNAL_0
);
4406 static VEC(static_tracepoint_marker_p
) *
4407 linux_child_static_tracepoint_markers_by_strid (struct target_ops
*self
,
4410 char s
[IPA_CMD_BUF_SIZE
];
4411 struct cleanup
*old_chain
;
4412 int pid
= ptid_get_pid (inferior_ptid
);
4413 VEC(static_tracepoint_marker_p
) *markers
= NULL
;
4414 struct static_tracepoint_marker
*marker
= NULL
;
4416 ptid_t ptid
= ptid_build (pid
, 0, 0);
4421 memcpy (s
, "qTfSTM", sizeof ("qTfSTM"));
4422 s
[sizeof ("qTfSTM")] = 0;
4424 agent_run_command (pid
, s
, strlen (s
) + 1);
4426 old_chain
= make_cleanup (free_current_marker
, &marker
);
4427 make_cleanup (cleanup_target_stop
, &ptid
);
4432 marker
= XCNEW (struct static_tracepoint_marker
);
4436 parse_static_tracepoint_marker_definition (p
, &p
, marker
);
4438 if (strid
== NULL
|| strcmp (strid
, marker
->str_id
) == 0)
4440 VEC_safe_push (static_tracepoint_marker_p
,
4446 release_static_tracepoint_marker (marker
);
4447 memset (marker
, 0, sizeof (*marker
));
4450 while (*p
++ == ','); /* comma-separated list */
4452 memcpy (s
, "qTsSTM", sizeof ("qTsSTM"));
4453 s
[sizeof ("qTsSTM")] = 0;
4454 agent_run_command (pid
, s
, strlen (s
) + 1);
4458 do_cleanups (old_chain
);
4463 /* Create a prototype generic GNU/Linux target. The client can override
4464 it with local methods. */
4467 linux_target_install_ops (struct target_ops
*t
)
4469 t
->to_insert_fork_catchpoint
= linux_child_insert_fork_catchpoint
;
4470 t
->to_remove_fork_catchpoint
= linux_child_remove_fork_catchpoint
;
4471 t
->to_insert_vfork_catchpoint
= linux_child_insert_vfork_catchpoint
;
4472 t
->to_remove_vfork_catchpoint
= linux_child_remove_vfork_catchpoint
;
4473 t
->to_insert_exec_catchpoint
= linux_child_insert_exec_catchpoint
;
4474 t
->to_remove_exec_catchpoint
= linux_child_remove_exec_catchpoint
;
4475 t
->to_set_syscall_catchpoint
= linux_child_set_syscall_catchpoint
;
4476 t
->to_pid_to_exec_file
= linux_child_pid_to_exec_file
;
4477 t
->to_post_startup_inferior
= linux_child_post_startup_inferior
;
4478 t
->to_post_attach
= linux_child_post_attach
;
4479 t
->to_follow_fork
= linux_child_follow_fork
;
4480 t
->to_make_corefile_notes
= linux_nat_make_corefile_notes
;
4482 super_xfer_partial
= t
->to_xfer_partial
;
4483 t
->to_xfer_partial
= linux_xfer_partial
;
4485 t
->to_static_tracepoint_markers_by_strid
4486 = linux_child_static_tracepoint_markers_by_strid
;
4492 struct target_ops
*t
;
4494 t
= inf_ptrace_target ();
4495 linux_target_install_ops (t
);
4501 linux_trad_target (CORE_ADDR (*register_u_offset
)(struct gdbarch
*, int, int))
4503 struct target_ops
*t
;
4505 t
= inf_ptrace_trad_target (register_u_offset
);
4506 linux_target_install_ops (t
);
4511 /* target_is_async_p implementation. */
4514 linux_nat_is_async_p (struct target_ops
*ops
)
4516 /* NOTE: palves 2008-03-21: We're only async when the user requests
4517 it explicitly with the "set target-async" command.
4518 Someday, linux will always be async. */
4519 return target_async_permitted
;
4522 /* target_can_async_p implementation. */
4525 linux_nat_can_async_p (struct target_ops
*ops
)
4527 /* NOTE: palves 2008-03-21: We're only async when the user requests
4528 it explicitly with the "set target-async" command.
4529 Someday, linux will always be async. */
4530 return target_async_permitted
;
4534 linux_nat_supports_non_stop (struct target_ops
*self
)
4539 /* True if we want to support multi-process. To be removed when GDB
4540 supports multi-exec. */
4542 int linux_multi_process
= 1;
4545 linux_nat_supports_multi_process (struct target_ops
*self
)
4547 return linux_multi_process
;
4551 linux_nat_supports_disable_randomization (struct target_ops
*self
)
4553 #ifdef HAVE_PERSONALITY
4560 static int async_terminal_is_ours
= 1;
4562 /* target_terminal_inferior implementation. */
4565 linux_nat_terminal_inferior (struct target_ops
*self
)
4567 if (!target_is_async_p ())
4569 /* Async mode is disabled. */
4570 child_terminal_inferior (self
);
4574 child_terminal_inferior (self
);
4576 /* Calls to target_terminal_*() are meant to be idempotent. */
4577 if (!async_terminal_is_ours
)
4580 delete_file_handler (input_fd
);
4581 async_terminal_is_ours
= 0;
4585 /* target_terminal_ours implementation. */
4588 linux_nat_terminal_ours (struct target_ops
*self
)
4590 if (!target_is_async_p ())
4592 /* Async mode is disabled. */
4593 child_terminal_ours (self
);
4597 /* GDB should never give the terminal to the inferior if the
4598 inferior is running in the background (run&, continue&, etc.),
4599 but claiming it sure should. */
4600 child_terminal_ours (self
);
4602 if (async_terminal_is_ours
)
4605 clear_sigint_trap ();
4606 add_file_handler (input_fd
, stdin_event_handler
, 0);
4607 async_terminal_is_ours
= 1;
4610 static void (*async_client_callback
) (enum inferior_event_type event_type
,
4612 static void *async_client_context
;
4614 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4615 so we notice when any child changes state, and notify the
4616 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4617 above to wait for the arrival of a SIGCHLD. */
4620 sigchld_handler (int signo
)
4622 int old_errno
= errno
;
4624 if (debug_linux_nat
)
4625 ui_file_write_async_safe (gdb_stdlog
,
4626 "sigchld\n", sizeof ("sigchld\n") - 1);
4628 if (signo
== SIGCHLD
4629 && linux_nat_event_pipe
[0] != -1)
4630 async_file_mark (); /* Let the event loop know that there are
4631 events to handle. */
4636 /* Callback registered with the target events file descriptor. */
4639 handle_target_event (int error
, gdb_client_data client_data
)
4641 (*async_client_callback
) (INF_REG_EVENT
, async_client_context
);
4644 /* Create/destroy the target events pipe. Returns previous state. */
4647 linux_async_pipe (int enable
)
4649 int previous
= (linux_nat_event_pipe
[0] != -1);
4651 if (previous
!= enable
)
4655 /* Block child signals while we create/destroy the pipe, as
4656 their handler writes to it. */
4657 block_child_signals (&prev_mask
);
4661 if (gdb_pipe_cloexec (linux_nat_event_pipe
) == -1)
4662 internal_error (__FILE__
, __LINE__
,
4663 "creating event pipe failed.");
4665 fcntl (linux_nat_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4666 fcntl (linux_nat_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4670 close (linux_nat_event_pipe
[0]);
4671 close (linux_nat_event_pipe
[1]);
4672 linux_nat_event_pipe
[0] = -1;
4673 linux_nat_event_pipe
[1] = -1;
4676 restore_child_signals_mask (&prev_mask
);
4682 /* target_async implementation. */
4685 linux_nat_async (struct target_ops
*ops
,
4686 void (*callback
) (enum inferior_event_type event_type
,
4690 if (callback
!= NULL
)
4692 async_client_callback
= callback
;
4693 async_client_context
= context
;
4694 if (!linux_async_pipe (1))
4696 add_file_handler (linux_nat_event_pipe
[0],
4697 handle_target_event
, NULL
);
4698 /* There may be pending events to handle. Tell the event loop
4705 async_client_callback
= callback
;
4706 async_client_context
= context
;
4707 delete_file_handler (linux_nat_event_pipe
[0]);
4708 linux_async_pipe (0);
4713 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4717 linux_nat_stop_lwp (struct lwp_info
*lwp
, void *data
)
4721 if (debug_linux_nat
)
4722 fprintf_unfiltered (gdb_stdlog
,
4723 "LNSL: running -> suspending %s\n",
4724 target_pid_to_str (lwp
->ptid
));
4727 if (lwp
->last_resume_kind
== resume_stop
)
4729 if (debug_linux_nat
)
4730 fprintf_unfiltered (gdb_stdlog
,
4731 "linux-nat: already stopping LWP %ld at "
4733 ptid_get_lwp (lwp
->ptid
));
4737 stop_callback (lwp
, NULL
);
4738 lwp
->last_resume_kind
= resume_stop
;
4742 /* Already known to be stopped; do nothing. */
4744 if (debug_linux_nat
)
4746 if (find_thread_ptid (lwp
->ptid
)->stop_requested
)
4747 fprintf_unfiltered (gdb_stdlog
,
4748 "LNSL: already stopped/stop_requested %s\n",
4749 target_pid_to_str (lwp
->ptid
));
4751 fprintf_unfiltered (gdb_stdlog
,
4752 "LNSL: already stopped/no "
4753 "stop_requested yet %s\n",
4754 target_pid_to_str (lwp
->ptid
));
4761 linux_nat_stop (struct target_ops
*self
, ptid_t ptid
)
4764 iterate_over_lwps (ptid
, linux_nat_stop_lwp
, NULL
);
4766 linux_ops
->to_stop (linux_ops
, ptid
);
4770 linux_nat_close (struct target_ops
*self
)
4772 /* Unregister from the event loop. */
4773 if (linux_nat_is_async_p (NULL
))
4774 linux_nat_async (NULL
, NULL
, 0);
4776 if (linux_ops
->to_close
)
4777 linux_ops
->to_close (linux_ops
);
4780 /* When requests are passed down from the linux-nat layer to the
4781 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4782 used. The address space pointer is stored in the inferior object,
4783 but the common code that is passed such ptid can't tell whether
4784 lwpid is a "main" process id or not (it assumes so). We reverse
4785 look up the "main" process id from the lwp here. */
4787 static struct address_space
*
4788 linux_nat_thread_address_space (struct target_ops
*t
, ptid_t ptid
)
4790 struct lwp_info
*lwp
;
4791 struct inferior
*inf
;
4794 pid
= ptid_get_lwp (ptid
);
4795 if (ptid_get_lwp (ptid
) == 0)
4797 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4799 lwp
= find_lwp_pid (ptid
);
4800 pid
= ptid_get_pid (lwp
->ptid
);
4804 /* A (pid,lwpid,0) ptid. */
4805 pid
= ptid_get_pid (ptid
);
4808 inf
= find_inferior_pid (pid
);
4809 gdb_assert (inf
!= NULL
);
4813 /* Return the cached value of the processor core for thread PTID. */
4816 linux_nat_core_of_thread (struct target_ops
*ops
, ptid_t ptid
)
4818 struct lwp_info
*info
= find_lwp_pid (ptid
);
4826 linux_nat_add_target (struct target_ops
*t
)
4828 /* Save the provided single-threaded target. We save this in a separate
4829 variable because another target we've inherited from (e.g. inf-ptrace)
4830 may have saved a pointer to T; we want to use it for the final
4831 process stratum target. */
4832 linux_ops_saved
= *t
;
4833 linux_ops
= &linux_ops_saved
;
4835 /* Override some methods for multithreading. */
4836 t
->to_create_inferior
= linux_nat_create_inferior
;
4837 t
->to_attach
= linux_nat_attach
;
4838 t
->to_detach
= linux_nat_detach
;
4839 t
->to_resume
= linux_nat_resume
;
4840 t
->to_wait
= linux_nat_wait
;
4841 t
->to_pass_signals
= linux_nat_pass_signals
;
4842 t
->to_xfer_partial
= linux_nat_xfer_partial
;
4843 t
->to_kill
= linux_nat_kill
;
4844 t
->to_mourn_inferior
= linux_nat_mourn_inferior
;
4845 t
->to_thread_alive
= linux_nat_thread_alive
;
4846 t
->to_pid_to_str
= linux_nat_pid_to_str
;
4847 t
->to_thread_name
= linux_nat_thread_name
;
4848 t
->to_has_thread_control
= tc_schedlock
;
4849 t
->to_thread_address_space
= linux_nat_thread_address_space
;
4850 t
->to_stopped_by_watchpoint
= linux_nat_stopped_by_watchpoint
;
4851 t
->to_stopped_data_address
= linux_nat_stopped_data_address
;
4853 t
->to_can_async_p
= linux_nat_can_async_p
;
4854 t
->to_is_async_p
= linux_nat_is_async_p
;
4855 t
->to_supports_non_stop
= linux_nat_supports_non_stop
;
4856 t
->to_async
= linux_nat_async
;
4857 t
->to_terminal_inferior
= linux_nat_terminal_inferior
;
4858 t
->to_terminal_ours
= linux_nat_terminal_ours
;
4859 t
->to_close
= linux_nat_close
;
4861 /* Methods for non-stop support. */
4862 t
->to_stop
= linux_nat_stop
;
4864 t
->to_supports_multi_process
= linux_nat_supports_multi_process
;
4866 t
->to_supports_disable_randomization
4867 = linux_nat_supports_disable_randomization
;
4869 t
->to_core_of_thread
= linux_nat_core_of_thread
;
4871 /* We don't change the stratum; this target will sit at
4872 process_stratum and thread_db will set at thread_stratum. This
4873 is a little strange, since this is a multi-threaded-capable
4874 target, but we want to be on the stack below thread_db, and we
4875 also want to be used for single-threaded processes. */
4880 /* Register a method to call whenever a new thread is attached. */
4882 linux_nat_set_new_thread (struct target_ops
*t
,
4883 void (*new_thread
) (struct lwp_info
*))
4885 /* Save the pointer. We only support a single registered instance
4886 of the GNU/Linux native target, so we do not need to map this to
4888 linux_nat_new_thread
= new_thread
;
4891 /* See declaration in linux-nat.h. */
4894 linux_nat_set_new_fork (struct target_ops
*t
,
4895 linux_nat_new_fork_ftype
*new_fork
)
4897 /* Save the pointer. */
4898 linux_nat_new_fork
= new_fork
;
4901 /* See declaration in linux-nat.h. */
4904 linux_nat_set_forget_process (struct target_ops
*t
,
4905 linux_nat_forget_process_ftype
*fn
)
4907 /* Save the pointer. */
4908 linux_nat_forget_process_hook
= fn
;
4911 /* See declaration in linux-nat.h. */
4914 linux_nat_forget_process (pid_t pid
)
4916 if (linux_nat_forget_process_hook
!= NULL
)
4917 linux_nat_forget_process_hook (pid
);
4920 /* Register a method that converts a siginfo object between the layout
4921 that ptrace returns, and the layout in the architecture of the
4924 linux_nat_set_siginfo_fixup (struct target_ops
*t
,
4925 int (*siginfo_fixup
) (siginfo_t
*,
4929 /* Save the pointer. */
4930 linux_nat_siginfo_fixup
= siginfo_fixup
;
4933 /* Register a method to call prior to resuming a thread. */
4936 linux_nat_set_prepare_to_resume (struct target_ops
*t
,
4937 void (*prepare_to_resume
) (struct lwp_info
*))
4939 /* Save the pointer. */
4940 linux_nat_prepare_to_resume
= prepare_to_resume
;
4943 /* See linux-nat.h. */
4946 linux_nat_get_siginfo (ptid_t ptid
, siginfo_t
*siginfo
)
4950 pid
= ptid_get_lwp (ptid
);
4952 pid
= ptid_get_pid (ptid
);
4955 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, siginfo
);
4958 memset (siginfo
, 0, sizeof (*siginfo
));
4964 /* Provide a prototype to silence -Wmissing-prototypes. */
4965 extern initialize_file_ftype _initialize_linux_nat
;
4968 _initialize_linux_nat (void)
4970 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance
,
4971 &debug_linux_nat
, _("\
4972 Set debugging of GNU/Linux lwp module."), _("\
4973 Show debugging of GNU/Linux lwp module."), _("\
4974 Enables printf debugging output."),
4976 show_debug_linux_nat
,
4977 &setdebuglist
, &showdebuglist
);
4979 /* Save this mask as the default. */
4980 sigprocmask (SIG_SETMASK
, NULL
, &normal_mask
);
4982 /* Install a SIGCHLD handler. */
4983 sigchld_action
.sa_handler
= sigchld_handler
;
4984 sigemptyset (&sigchld_action
.sa_mask
);
4985 sigchld_action
.sa_flags
= SA_RESTART
;
4987 /* Make it the default. */
4988 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
4990 /* Make sure we don't block SIGCHLD during a sigsuspend. */
4991 sigprocmask (SIG_SETMASK
, NULL
, &suspend_mask
);
4992 sigdelset (&suspend_mask
, SIGCHLD
);
4994 sigemptyset (&blocked_mask
);
4998 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
4999 the GNU/Linux Threads library and therefore doesn't really belong
5002 /* Read variable NAME in the target and return its value if found.
5003 Otherwise return zero. It is assumed that the type of the variable
5007 get_signo (const char *name
)
5009 struct bound_minimal_symbol ms
;
5012 ms
= lookup_minimal_symbol (name
, NULL
, NULL
);
5013 if (ms
.minsym
== NULL
)
5016 if (target_read_memory (BMSYMBOL_VALUE_ADDRESS (ms
), (gdb_byte
*) &signo
,
5017 sizeof (signo
)) != 0)
5023 /* Return the set of signals used by the threads library in *SET. */
5026 lin_thread_get_thread_signals (sigset_t
*set
)
5028 struct sigaction action
;
5029 int restart
, cancel
;
5031 sigemptyset (&blocked_mask
);
5034 restart
= get_signo ("__pthread_sig_restart");
5035 cancel
= get_signo ("__pthread_sig_cancel");
5037 /* LinuxThreads normally uses the first two RT signals, but in some legacy
5038 cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
5039 not provide any way for the debugger to query the signal numbers -
5040 fortunately they don't change! */
5043 restart
= __SIGRTMIN
;
5046 cancel
= __SIGRTMIN
+ 1;
5048 sigaddset (set
, restart
);
5049 sigaddset (set
, cancel
);
5051 /* The GNU/Linux Threads library makes terminating threads send a
5052 special "cancel" signal instead of SIGCHLD. Make sure we catch
5053 those (to prevent them from terminating GDB itself, which is
5054 likely to be their default action) and treat them the same way as
5057 action
.sa_handler
= sigchld_handler
;
5058 sigemptyset (&action
.sa_mask
);
5059 action
.sa_flags
= SA_RESTART
;
5060 sigaction (cancel
, &action
, NULL
);
5062 /* We block the "cancel" signal throughout this code ... */
5063 sigaddset (&blocked_mask
, cancel
);
5064 sigprocmask (SIG_BLOCK
, &blocked_mask
, NULL
);
5066 /* ... except during a sigsuspend. */
5067 sigdelset (&suspend_mask
, cancel
);