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/>. */
24 #include "nat/linux-nat.h"
25 #include "nat/linux-waitpid.h"
27 #ifdef HAVE_TKILL_SYSCALL
29 #include <sys/syscall.h>
31 #include <sys/ptrace.h>
32 #include "linux-nat.h"
33 #include "nat/linux-ptrace.h"
34 #include "nat/linux-procfs.h"
35 #include "linux-fork.h"
36 #include "gdbthread.h"
40 #include "inf-child.h"
41 #include "inf-ptrace.h"
43 #include <sys/procfs.h> /* for elf_gregset etc. */
44 #include "elf-bfd.h" /* for elfcore_write_* */
45 #include "gregset.h" /* for gregset */
46 #include "gdbcore.h" /* for get_exec_file */
47 #include <ctype.h> /* for isdigit */
48 #include <sys/stat.h> /* for struct stat */
49 #include <fcntl.h> /* for O_RDONLY */
51 #include "event-loop.h"
52 #include "event-top.h"
54 #include <sys/types.h>
56 #include "xml-support.h"
59 #include "nat/linux-osdata.h"
60 #include "linux-tdep.h"
63 #include "tracepoint.h"
65 #include "target-descriptions.h"
66 #include "filestuff.h"
70 #define SPUFS_MAGIC 0x23c9b64e
73 #ifdef HAVE_PERSONALITY
74 # include <sys/personality.h>
75 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
76 # define ADDR_NO_RANDOMIZE 0x0040000
78 #endif /* HAVE_PERSONALITY */
80 /* This comment documents high-level logic of this file.
82 Waiting for events in sync mode
83 ===============================
85 When waiting for an event in a specific thread, we just use waitpid, passing
86 the specific pid, and not passing WNOHANG.
88 When waiting for an event in all threads, waitpid is not quite good. Prior to
89 version 2.4, Linux can either wait for event in main thread, or in secondary
90 threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might
91 miss an event. The solution is to use non-blocking waitpid, together with
92 sigsuspend. First, we use non-blocking waitpid to get an event in the main
93 process, if any. Second, we use non-blocking waitpid with the __WCLONED
94 flag to check for events in cloned processes. If nothing is found, we use
95 sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something
96 happened to a child process -- and SIGCHLD will be delivered both for events
97 in main debugged process and in cloned processes. As soon as we know there's
98 an event, we get back to calling nonblocking waitpid with and without
101 Note that SIGCHLD should be blocked between waitpid and sigsuspend calls,
102 so that we don't miss a signal. If SIGCHLD arrives in between, when it's
103 blocked, the signal becomes pending and sigsuspend immediately
104 notices it and returns.
106 Waiting for events in async mode
107 ================================
109 In async mode, GDB should always be ready to handle both user input
110 and target events, so neither blocking waitpid nor sigsuspend are
111 viable options. Instead, we should asynchronously notify the GDB main
112 event loop whenever there's an unprocessed event from the target. We
113 detect asynchronous target events by handling SIGCHLD signals. To
114 notify the event loop about target events, the self-pipe trick is used
115 --- a pipe is registered as waitable event source in the event loop,
116 the event loop select/poll's on the read end of this pipe (as well on
117 other event sources, e.g., stdin), and the SIGCHLD handler writes a
118 byte to this pipe. This is more portable than relying on
119 pselect/ppoll, since on kernels that lack those syscalls, libc
120 emulates them with select/poll+sigprocmask, and that is racy
121 (a.k.a. plain broken).
123 Obviously, if we fail to notify the event loop if there's a target
124 event, it's bad. OTOH, if we notify the event loop when there's no
125 event from the target, linux_nat_wait will detect that there's no real
126 event to report, and return event of type TARGET_WAITKIND_IGNORE.
127 This is mostly harmless, but it will waste time and is better avoided.
129 The main design point is that every time GDB is outside linux-nat.c,
130 we have a SIGCHLD handler installed that is called when something
131 happens to the target and notifies the GDB event loop. Whenever GDB
132 core decides to handle the event, and calls into linux-nat.c, we
133 process things as in sync mode, except that the we never block in
136 While processing an event, we may end up momentarily blocked in
137 waitpid calls. Those waitpid calls, while blocking, are guarantied to
138 return quickly. E.g., in all-stop mode, before reporting to the core
139 that an LWP hit a breakpoint, all LWPs are stopped by sending them
140 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
141 Note that this is different from blocking indefinitely waiting for the
142 next event --- here, we're already handling an event.
147 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
148 signal is not entirely significant; we just need for a signal to be delivered,
149 so that we can intercept it. SIGSTOP's advantage is that it can not be
150 blocked. A disadvantage is that it is not a real-time signal, so it can only
151 be queued once; we do not keep track of other sources of SIGSTOP.
153 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
154 use them, because they have special behavior when the signal is generated -
155 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
156 kills the entire thread group.
158 A delivered SIGSTOP would stop the entire thread group, not just the thread we
159 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
160 cancel it (by PTRACE_CONT without passing SIGSTOP).
162 We could use a real-time signal instead. This would solve those problems; we
163 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
164 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
165 generates it, and there are races with trying to find a signal that is not
169 #define O_LARGEFILE 0
172 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
173 the use of the multi-threaded target. */
174 static struct target_ops
*linux_ops
;
175 static struct target_ops linux_ops_saved
;
177 /* The method to call, if any, when a new thread is attached. */
178 static void (*linux_nat_new_thread
) (struct lwp_info
*);
180 /* The method to call, if any, when a new fork is attached. */
181 static linux_nat_new_fork_ftype
*linux_nat_new_fork
;
183 /* The method to call, if any, when a process is no longer
185 static linux_nat_forget_process_ftype
*linux_nat_forget_process_hook
;
187 /* Hook to call prior to resuming a thread. */
188 static void (*linux_nat_prepare_to_resume
) (struct lwp_info
*);
190 /* The method to call, if any, when the siginfo object needs to be
191 converted between the layout returned by ptrace, and the layout in
192 the architecture of the inferior. */
193 static int (*linux_nat_siginfo_fixup
) (siginfo_t
*,
197 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
198 Called by our to_xfer_partial. */
199 static target_xfer_partial_ftype
*super_xfer_partial
;
201 /* The saved to_close method, inherited from inf-ptrace.c.
202 Called by our to_close. */
203 static void (*super_close
) (struct target_ops
*);
205 static unsigned int debug_linux_nat
;
207 show_debug_linux_nat (struct ui_file
*file
, int from_tty
,
208 struct cmd_list_element
*c
, const char *value
)
210 fprintf_filtered (file
, _("Debugging of GNU/Linux lwp module is %s.\n"),
214 struct simple_pid_list
218 struct simple_pid_list
*next
;
220 struct simple_pid_list
*stopped_pids
;
222 /* Async mode support. */
224 /* The read/write ends of the pipe registered as waitable file in the
226 static int linux_nat_event_pipe
[2] = { -1, -1 };
228 /* Flush the event pipe. */
231 async_file_flush (void)
238 ret
= read (linux_nat_event_pipe
[0], &buf
, 1);
240 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
243 /* Put something (anything, doesn't matter what, or how much) in event
244 pipe, so that the select/poll in the event-loop realizes we have
245 something to process. */
248 async_file_mark (void)
252 /* It doesn't really matter what the pipe contains, as long we end
253 up with something in it. Might as well flush the previous
259 ret
= write (linux_nat_event_pipe
[1], "+", 1);
261 while (ret
== -1 && errno
== EINTR
);
263 /* Ignore EAGAIN. If the pipe is full, the event loop will already
264 be awakened anyway. */
267 static int kill_lwp (int lwpid
, int signo
);
269 static int stop_callback (struct lwp_info
*lp
, void *data
);
271 static void block_child_signals (sigset_t
*prev_mask
);
272 static void restore_child_signals_mask (sigset_t
*prev_mask
);
275 static struct lwp_info
*add_lwp (ptid_t ptid
);
276 static void purge_lwp_list (int pid
);
277 static void delete_lwp (ptid_t ptid
);
278 static struct lwp_info
*find_lwp_pid (ptid_t ptid
);
281 /* Trivial list manipulation functions to keep track of a list of
282 new stopped processes. */
284 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
286 struct simple_pid_list
*new_pid
= xmalloc (sizeof (struct simple_pid_list
));
289 new_pid
->status
= status
;
290 new_pid
->next
= *listp
;
295 in_pid_list_p (struct simple_pid_list
*list
, int pid
)
297 struct simple_pid_list
*p
;
299 for (p
= list
; p
!= NULL
; p
= p
->next
)
306 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *statusp
)
308 struct simple_pid_list
**p
;
310 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
311 if ((*p
)->pid
== pid
)
313 struct simple_pid_list
*next
= (*p
)->next
;
315 *statusp
= (*p
)->status
;
323 /* Initialize ptrace warnings and check for supported ptrace
324 features given PID. */
327 linux_init_ptrace (pid_t pid
)
329 linux_enable_event_reporting (pid
);
330 linux_ptrace_init_warnings ();
334 linux_child_post_attach (struct target_ops
*self
, int pid
)
336 linux_init_ptrace (pid
);
340 linux_child_post_startup_inferior (struct target_ops
*self
, ptid_t ptid
)
342 linux_init_ptrace (ptid_get_pid (ptid
));
345 /* Return the number of known LWPs in the tgid given by PID. */
353 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
354 if (ptid_get_pid (lp
->ptid
) == pid
)
360 /* Call delete_lwp with prototype compatible for make_cleanup. */
363 delete_lwp_cleanup (void *lp_voidp
)
365 struct lwp_info
*lp
= lp_voidp
;
367 delete_lwp (lp
->ptid
);
370 /* Target hook for follow_fork. On entry inferior_ptid must be the
371 ptid of the followed inferior. At return, inferior_ptid will be
375 linux_child_follow_fork (struct target_ops
*ops
, int follow_child
,
380 struct lwp_info
*child_lp
= NULL
;
381 int status
= W_STOPCODE (0);
382 struct cleanup
*old_chain
;
384 int parent_pid
, child_pid
;
386 has_vforked
= (inferior_thread ()->pending_follow
.kind
387 == TARGET_WAITKIND_VFORKED
);
388 parent_pid
= ptid_get_lwp (inferior_ptid
);
390 parent_pid
= ptid_get_pid (inferior_ptid
);
392 = ptid_get_pid (inferior_thread ()->pending_follow
.value
.related_pid
);
395 /* We're already attached to the parent, by default. */
396 old_chain
= save_inferior_ptid ();
397 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
398 child_lp
= add_lwp (inferior_ptid
);
399 child_lp
->stopped
= 1;
400 child_lp
->last_resume_kind
= resume_stop
;
402 /* Detach new forked process? */
405 make_cleanup (delete_lwp_cleanup
, child_lp
);
407 if (linux_nat_prepare_to_resume
!= NULL
)
408 linux_nat_prepare_to_resume (child_lp
);
410 /* When debugging an inferior in an architecture that supports
411 hardware single stepping on a kernel without commit
412 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child
413 process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits
414 set if the parent process had them set.
415 To work around this, single step the child process
416 once before detaching to clear the flags. */
418 if (!gdbarch_software_single_step_p (target_thread_architecture
421 linux_disable_event_reporting (child_pid
);
422 if (ptrace (PTRACE_SINGLESTEP
, child_pid
, 0, 0) < 0)
423 perror_with_name (_("Couldn't do single step"));
424 if (my_waitpid (child_pid
, &status
, 0) < 0)
425 perror_with_name (_("Couldn't wait vfork process"));
428 if (WIFSTOPPED (status
))
432 signo
= WSTOPSIG (status
);
434 && !signal_pass_state (gdb_signal_from_host (signo
)))
436 ptrace (PTRACE_DETACH
, child_pid
, 0, signo
);
439 /* Resets value of inferior_ptid to parent ptid. */
440 do_cleanups (old_chain
);
444 /* Let the thread_db layer learn about this new process. */
445 check_for_thread_db ();
448 do_cleanups (old_chain
);
452 struct lwp_info
*parent_lp
;
454 parent_lp
= find_lwp_pid (pid_to_ptid (parent_pid
));
455 gdb_assert (linux_supports_tracefork () >= 0);
457 if (linux_supports_tracevforkdone ())
460 fprintf_unfiltered (gdb_stdlog
,
461 "LCFF: waiting for VFORK_DONE on %d\n",
463 parent_lp
->stopped
= 1;
465 /* We'll handle the VFORK_DONE event like any other
466 event, in target_wait. */
470 /* We can't insert breakpoints until the child has
471 finished with the shared memory region. We need to
472 wait until that happens. Ideal would be to just
474 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
475 - waitpid (parent_pid, &status, __WALL);
476 However, most architectures can't handle a syscall
477 being traced on the way out if it wasn't traced on
480 We might also think to loop, continuing the child
481 until it exits or gets a SIGTRAP. One problem is
482 that the child might call ptrace with PTRACE_TRACEME.
484 There's no simple and reliable way to figure out when
485 the vforked child will be done with its copy of the
486 shared memory. We could step it out of the syscall,
487 two instructions, let it go, and then single-step the
488 parent once. When we have hardware single-step, this
489 would work; with software single-step it could still
490 be made to work but we'd have to be able to insert
491 single-step breakpoints in the child, and we'd have
492 to insert -just- the single-step breakpoint in the
493 parent. Very awkward.
495 In the end, the best we can do is to make sure it
496 runs for a little while. Hopefully it will be out of
497 range of any breakpoints we reinsert. Usually this
498 is only the single-step breakpoint at vfork's return
502 fprintf_unfiltered (gdb_stdlog
,
503 "LCFF: no VFORK_DONE "
504 "support, sleeping a bit\n");
508 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
509 and leave it pending. The next linux_nat_resume call
510 will notice a pending event, and bypasses actually
511 resuming the inferior. */
512 parent_lp
->status
= 0;
513 parent_lp
->waitstatus
.kind
= TARGET_WAITKIND_VFORK_DONE
;
514 parent_lp
->stopped
= 1;
516 /* If we're in async mode, need to tell the event loop
517 there's something here to process. */
518 if (target_can_async_p ())
525 struct lwp_info
*child_lp
;
527 child_lp
= add_lwp (inferior_ptid
);
528 child_lp
->stopped
= 1;
529 child_lp
->last_resume_kind
= resume_stop
;
531 /* Let the thread_db layer learn about this new process. */
532 check_for_thread_db ();
540 linux_child_insert_fork_catchpoint (struct target_ops
*self
, int pid
)
542 return !linux_supports_tracefork ();
546 linux_child_remove_fork_catchpoint (struct target_ops
*self
, int pid
)
552 linux_child_insert_vfork_catchpoint (struct target_ops
*self
, int pid
)
554 return !linux_supports_tracefork ();
558 linux_child_remove_vfork_catchpoint (struct target_ops
*self
, int pid
)
564 linux_child_insert_exec_catchpoint (struct target_ops
*self
, int pid
)
566 return !linux_supports_tracefork ();
570 linux_child_remove_exec_catchpoint (struct target_ops
*self
, int pid
)
576 linux_child_set_syscall_catchpoint (struct target_ops
*self
,
577 int pid
, int needed
, int any_count
,
578 int table_size
, int *table
)
580 if (!linux_supports_tracesysgood ())
583 /* On GNU/Linux, we ignore the arguments. It means that we only
584 enable the syscall catchpoints, but do not disable them.
586 Also, we do not use the `table' information because we do not
587 filter system calls here. We let GDB do the logic for us. */
591 /* On GNU/Linux there are no real LWP's. The closest thing to LWP's
592 are processes sharing the same VM space. A multi-threaded process
593 is basically a group of such processes. However, such a grouping
594 is almost entirely a user-space issue; the kernel doesn't enforce
595 such a grouping at all (this might change in the future). In
596 general, we'll rely on the threads library (i.e. the GNU/Linux
597 Threads library) to provide such a grouping.
599 It is perfectly well possible to write a multi-threaded application
600 without the assistance of a threads library, by using the clone
601 system call directly. This module should be able to give some
602 rudimentary support for debugging such applications if developers
603 specify the CLONE_PTRACE flag in the clone system call, and are
604 using the Linux kernel 2.4 or above.
606 Note that there are some peculiarities in GNU/Linux that affect
609 - In general one should specify the __WCLONE flag to waitpid in
610 order to make it report events for any of the cloned processes
611 (and leave it out for the initial process). However, if a cloned
612 process has exited the exit status is only reported if the
613 __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
614 we cannot use it since GDB must work on older systems too.
616 - When a traced, cloned process exits and is waited for by the
617 debugger, the kernel reassigns it to the original parent and
618 keeps it around as a "zombie". Somehow, the GNU/Linux Threads
619 library doesn't notice this, which leads to the "zombie problem":
620 When debugged a multi-threaded process that spawns a lot of
621 threads will run out of processes, even if the threads exit,
622 because the "zombies" stay around. */
624 /* List of known LWPs. */
625 struct lwp_info
*lwp_list
;
628 /* Original signal mask. */
629 static sigset_t normal_mask
;
631 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
632 _initialize_linux_nat. */
633 static sigset_t suspend_mask
;
635 /* Signals to block to make that sigsuspend work. */
636 static sigset_t blocked_mask
;
638 /* SIGCHLD action. */
639 struct sigaction sigchld_action
;
641 /* Block child signals (SIGCHLD and linux threads signals), and store
642 the previous mask in PREV_MASK. */
645 block_child_signals (sigset_t
*prev_mask
)
647 /* Make sure SIGCHLD is blocked. */
648 if (!sigismember (&blocked_mask
, SIGCHLD
))
649 sigaddset (&blocked_mask
, SIGCHLD
);
651 sigprocmask (SIG_BLOCK
, &blocked_mask
, prev_mask
);
654 /* Restore child signals mask, previously returned by
655 block_child_signals. */
658 restore_child_signals_mask (sigset_t
*prev_mask
)
660 sigprocmask (SIG_SETMASK
, prev_mask
, NULL
);
663 /* Mask of signals to pass directly to the inferior. */
664 static sigset_t pass_mask
;
666 /* Update signals to pass to the inferior. */
668 linux_nat_pass_signals (struct target_ops
*self
,
669 int numsigs
, unsigned char *pass_signals
)
673 sigemptyset (&pass_mask
);
675 for (signo
= 1; signo
< NSIG
; signo
++)
677 int target_signo
= gdb_signal_from_host (signo
);
678 if (target_signo
< numsigs
&& pass_signals
[target_signo
])
679 sigaddset (&pass_mask
, signo
);
685 /* Prototypes for local functions. */
686 static int stop_wait_callback (struct lwp_info
*lp
, void *data
);
687 static int linux_thread_alive (ptid_t ptid
);
688 static char *linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
);
692 /* Destroy and free LP. */
695 lwp_free (struct lwp_info
*lp
)
697 xfree (lp
->arch_private
);
701 /* Remove all LWPs belong to PID from the lwp list. */
704 purge_lwp_list (int pid
)
706 struct lwp_info
*lp
, *lpprev
, *lpnext
;
710 for (lp
= lwp_list
; lp
; lp
= lpnext
)
714 if (ptid_get_pid (lp
->ptid
) == pid
)
719 lpprev
->next
= lp
->next
;
728 /* Add the LWP specified by PTID to the list. PTID is the first LWP
729 in the process. Return a pointer to the structure describing the
732 This differs from add_lwp in that we don't let the arch specific
733 bits know about this new thread. Current clients of this callback
734 take the opportunity to install watchpoints in the new thread, and
735 we shouldn't do that for the first thread. If we're spawning a
736 child ("run"), the thread executes the shell wrapper first, and we
737 shouldn't touch it until it execs the program we want to debug.
738 For "attach", it'd be okay to call the callback, but it's not
739 necessary, because watchpoints can't yet have been inserted into
742 static struct lwp_info
*
743 add_initial_lwp (ptid_t ptid
)
747 gdb_assert (ptid_lwp_p (ptid
));
749 lp
= (struct lwp_info
*) xmalloc (sizeof (struct lwp_info
));
751 memset (lp
, 0, sizeof (struct lwp_info
));
753 lp
->last_resume_kind
= resume_continue
;
754 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
765 /* Add the LWP specified by PID to the list. Return a pointer to the
766 structure describing the new LWP. The LWP should already be
769 static struct lwp_info
*
770 add_lwp (ptid_t ptid
)
774 lp
= add_initial_lwp (ptid
);
776 /* Let the arch specific bits know about this new thread. Current
777 clients of this callback take the opportunity to install
778 watchpoints in the new thread. We don't do this for the first
779 thread though. See add_initial_lwp. */
780 if (linux_nat_new_thread
!= NULL
)
781 linux_nat_new_thread (lp
);
786 /* Remove the LWP specified by PID from the list. */
789 delete_lwp (ptid_t ptid
)
791 struct lwp_info
*lp
, *lpprev
;
795 for (lp
= lwp_list
; lp
; lpprev
= lp
, lp
= lp
->next
)
796 if (ptid_equal (lp
->ptid
, ptid
))
803 lpprev
->next
= lp
->next
;
810 /* Return a pointer to the structure describing the LWP corresponding
811 to PID. If no corresponding LWP could be found, return NULL. */
813 static struct lwp_info
*
814 find_lwp_pid (ptid_t ptid
)
819 if (ptid_lwp_p (ptid
))
820 lwp
= ptid_get_lwp (ptid
);
822 lwp
= ptid_get_pid (ptid
);
824 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
825 if (lwp
== ptid_get_lwp (lp
->ptid
))
831 /* Call CALLBACK with its second argument set to DATA for every LWP in
832 the list. If CALLBACK returns 1 for a particular LWP, return a
833 pointer to the structure describing that LWP immediately.
834 Otherwise return NULL. */
837 iterate_over_lwps (ptid_t filter
,
838 int (*callback
) (struct lwp_info
*, void *),
841 struct lwp_info
*lp
, *lpnext
;
843 for (lp
= lwp_list
; lp
; lp
= lpnext
)
847 if (ptid_match (lp
->ptid
, filter
))
849 if ((*callback
) (lp
, data
))
857 /* Update our internal state when changing from one checkpoint to
858 another indicated by NEW_PTID. We can only switch single-threaded
859 applications, so we only create one new LWP, and the previous list
863 linux_nat_switch_fork (ptid_t new_ptid
)
867 purge_lwp_list (ptid_get_pid (inferior_ptid
));
869 lp
= add_lwp (new_ptid
);
872 /* This changes the thread's ptid while preserving the gdb thread
873 num. Also changes the inferior pid, while preserving the
875 thread_change_ptid (inferior_ptid
, new_ptid
);
877 /* We've just told GDB core that the thread changed target id, but,
878 in fact, it really is a different thread, with different register
880 registers_changed ();
883 /* Handle the exit of a single thread LP. */
886 exit_lwp (struct lwp_info
*lp
)
888 struct thread_info
*th
= find_thread_ptid (lp
->ptid
);
892 if (print_thread_events
)
893 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp
->ptid
));
895 delete_thread (lp
->ptid
);
898 delete_lwp (lp
->ptid
);
901 /* Wait for the LWP specified by LP, which we have just attached to.
902 Returns a wait status for that LWP, to cache. */
905 linux_nat_post_attach_wait (ptid_t ptid
, int first
, int *cloned
,
908 pid_t new_pid
, pid
= ptid_get_lwp (ptid
);
911 if (linux_proc_pid_is_stopped (pid
))
914 fprintf_unfiltered (gdb_stdlog
,
915 "LNPAW: Attaching to a stopped process\n");
917 /* The process is definitely stopped. It is in a job control
918 stop, unless the kernel predates the TASK_STOPPED /
919 TASK_TRACED distinction, in which case it might be in a
920 ptrace stop. Make sure it is in a ptrace stop; from there we
921 can kill it, signal it, et cetera.
923 First make sure there is a pending SIGSTOP. Since we are
924 already attached, the process can not transition from stopped
925 to running without a PTRACE_CONT; so we know this signal will
926 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
927 probably already in the queue (unless this kernel is old
928 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
929 is not an RT signal, it can only be queued once. */
930 kill_lwp (pid
, SIGSTOP
);
932 /* Finally, resume the stopped process. This will deliver the SIGSTOP
933 (or a higher priority signal, just like normal PTRACE_ATTACH). */
934 ptrace (PTRACE_CONT
, pid
, 0, 0);
937 /* Make sure the initial process is stopped. The user-level threads
938 layer might want to poke around in the inferior, and that won't
939 work if things haven't stabilized yet. */
940 new_pid
= my_waitpid (pid
, &status
, 0);
941 if (new_pid
== -1 && errno
== ECHILD
)
944 warning (_("%s is a cloned process"), target_pid_to_str (ptid
));
946 /* Try again with __WCLONE to check cloned processes. */
947 new_pid
= my_waitpid (pid
, &status
, __WCLONE
);
951 gdb_assert (pid
== new_pid
);
953 if (!WIFSTOPPED (status
))
955 /* The pid we tried to attach has apparently just exited. */
957 fprintf_unfiltered (gdb_stdlog
, "LNPAW: Failed to stop %d: %s",
958 pid
, status_to_str (status
));
962 if (WSTOPSIG (status
) != SIGSTOP
)
966 fprintf_unfiltered (gdb_stdlog
,
967 "LNPAW: Received %s after attaching\n",
968 status_to_str (status
));
974 /* Attach to the LWP specified by PID. Return 0 if successful, -1 if
975 the new LWP could not be attached, or 1 if we're already auto
976 attached to this thread, but haven't processed the
977 PTRACE_EVENT_CLONE event of its parent thread, so we just ignore
978 its existance, without considering it an error. */
981 lin_lwp_attach_lwp (ptid_t ptid
)
986 gdb_assert (ptid_lwp_p (ptid
));
988 lp
= find_lwp_pid (ptid
);
989 lwpid
= ptid_get_lwp (ptid
);
991 /* We assume that we're already attached to any LWP that has an id
992 equal to the overall process id, and to any LWP that is already
993 in our list of LWPs. If we're not seeing exit events from threads
994 and we've had PID wraparound since we last tried to stop all threads,
995 this assumption might be wrong; fortunately, this is very unlikely
997 if (lwpid
!= ptid_get_pid (ptid
) && lp
== NULL
)
999 int status
, cloned
= 0, signalled
= 0;
1001 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) < 0)
1003 if (linux_supports_tracefork ())
1005 /* If we haven't stopped all threads when we get here,
1006 we may have seen a thread listed in thread_db's list,
1007 but not processed the PTRACE_EVENT_CLONE yet. If
1008 that's the case, ignore this new thread, and let
1009 normal event handling discover it later. */
1010 if (in_pid_list_p (stopped_pids
, lwpid
))
1012 /* We've already seen this thread stop, but we
1013 haven't seen the PTRACE_EVENT_CLONE extended
1022 /* See if we've got a stop for this new child
1023 pending. If so, we're already attached. */
1024 new_pid
= my_waitpid (lwpid
, &status
, WNOHANG
);
1025 if (new_pid
== -1 && errno
== ECHILD
)
1026 new_pid
= my_waitpid (lwpid
, &status
, __WCLONE
| WNOHANG
);
1029 if (WIFSTOPPED (status
))
1030 add_to_pid_list (&stopped_pids
, lwpid
, status
);
1036 /* If we fail to attach to the thread, issue a warning,
1037 but continue. One way this can happen is if thread
1038 creation is interrupted; as of Linux kernel 2.6.19, a
1039 bug may place threads in the thread list and then fail
1041 warning (_("Can't attach %s: %s"), target_pid_to_str (ptid
),
1042 safe_strerror (errno
));
1046 if (debug_linux_nat
)
1047 fprintf_unfiltered (gdb_stdlog
,
1048 "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
1049 target_pid_to_str (ptid
));
1051 status
= linux_nat_post_attach_wait (ptid
, 0, &cloned
, &signalled
);
1052 if (!WIFSTOPPED (status
))
1055 lp
= add_lwp (ptid
);
1057 lp
->cloned
= cloned
;
1058 lp
->signalled
= signalled
;
1059 if (WSTOPSIG (status
) != SIGSTOP
)
1062 lp
->status
= status
;
1065 target_post_attach (ptid_get_lwp (lp
->ptid
));
1067 if (debug_linux_nat
)
1069 fprintf_unfiltered (gdb_stdlog
,
1070 "LLAL: waitpid %s received %s\n",
1071 target_pid_to_str (ptid
),
1072 status_to_str (status
));
1077 /* We assume that the LWP representing the original process is
1078 already stopped. Mark it as stopped in the data structure
1079 that the GNU/linux ptrace layer uses to keep track of
1080 threads. Note that this won't have already been done since
1081 the main thread will have, we assume, been stopped by an
1082 attach from a different layer. */
1084 lp
= add_lwp (ptid
);
1088 lp
->last_resume_kind
= resume_stop
;
1093 linux_nat_create_inferior (struct target_ops
*ops
,
1094 char *exec_file
, char *allargs
, char **env
,
1097 #ifdef HAVE_PERSONALITY
1098 int personality_orig
= 0, personality_set
= 0;
1099 #endif /* HAVE_PERSONALITY */
1101 /* The fork_child mechanism is synchronous and calls target_wait, so
1102 we have to mask the async mode. */
1104 #ifdef HAVE_PERSONALITY
1105 if (disable_randomization
)
1108 personality_orig
= personality (0xffffffff);
1109 if (errno
== 0 && !(personality_orig
& ADDR_NO_RANDOMIZE
))
1111 personality_set
= 1;
1112 personality (personality_orig
| ADDR_NO_RANDOMIZE
);
1114 if (errno
!= 0 || (personality_set
1115 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE
)))
1116 warning (_("Error disabling address space randomization: %s"),
1117 safe_strerror (errno
));
1119 #endif /* HAVE_PERSONALITY */
1121 /* Make sure we report all signals during startup. */
1122 linux_nat_pass_signals (ops
, 0, NULL
);
1124 linux_ops
->to_create_inferior (ops
, exec_file
, allargs
, env
, from_tty
);
1126 #ifdef HAVE_PERSONALITY
1127 if (personality_set
)
1130 personality (personality_orig
);
1132 warning (_("Error restoring address space randomization: %s"),
1133 safe_strerror (errno
));
1135 #endif /* HAVE_PERSONALITY */
1139 linux_nat_attach (struct target_ops
*ops
, const char *args
, int from_tty
)
1141 struct lwp_info
*lp
;
1144 volatile struct gdb_exception ex
;
1146 /* Make sure we report all signals during attach. */
1147 linux_nat_pass_signals (ops
, 0, NULL
);
1149 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
1151 linux_ops
->to_attach (ops
, args
, from_tty
);
1155 pid_t pid
= parse_pid_to_attach (args
);
1156 struct buffer buffer
;
1157 char *message
, *buffer_s
;
1159 message
= xstrdup (ex
.message
);
1160 make_cleanup (xfree
, message
);
1162 buffer_init (&buffer
);
1163 linux_ptrace_attach_fail_reason (pid
, &buffer
);
1165 buffer_grow_str0 (&buffer
, "");
1166 buffer_s
= buffer_finish (&buffer
);
1167 make_cleanup (xfree
, buffer_s
);
1169 if (*buffer_s
!= '\0')
1170 throw_error (ex
.error
, "warning: %s\n%s", buffer_s
, message
);
1172 throw_error (ex
.error
, "%s", message
);
1175 /* The ptrace base target adds the main thread with (pid,0,0)
1176 format. Decorate it with lwp info. */
1177 ptid
= ptid_build (ptid_get_pid (inferior_ptid
),
1178 ptid_get_pid (inferior_ptid
),
1180 thread_change_ptid (inferior_ptid
, ptid
);
1182 /* Add the initial process as the first LWP to the list. */
1183 lp
= add_initial_lwp (ptid
);
1185 status
= linux_nat_post_attach_wait (lp
->ptid
, 1, &lp
->cloned
,
1187 if (!WIFSTOPPED (status
))
1189 if (WIFEXITED (status
))
1191 int exit_code
= WEXITSTATUS (status
);
1193 target_terminal_ours ();
1194 target_mourn_inferior ();
1196 error (_("Unable to attach: program exited normally."));
1198 error (_("Unable to attach: program exited with code %d."),
1201 else if (WIFSIGNALED (status
))
1203 enum gdb_signal signo
;
1205 target_terminal_ours ();
1206 target_mourn_inferior ();
1208 signo
= gdb_signal_from_host (WTERMSIG (status
));
1209 error (_("Unable to attach: program terminated with signal "
1211 gdb_signal_to_name (signo
),
1212 gdb_signal_to_string (signo
));
1215 internal_error (__FILE__
, __LINE__
,
1216 _("unexpected status %d for PID %ld"),
1217 status
, (long) ptid_get_lwp (ptid
));
1222 /* Save the wait status to report later. */
1224 if (debug_linux_nat
)
1225 fprintf_unfiltered (gdb_stdlog
,
1226 "LNA: waitpid %ld, saving status %s\n",
1227 (long) ptid_get_pid (lp
->ptid
), status_to_str (status
));
1229 lp
->status
= status
;
1231 if (target_can_async_p ())
1232 target_async (inferior_event_handler
, 0);
1235 /* Get pending status of LP. */
1237 get_pending_status (struct lwp_info
*lp
, int *status
)
1239 enum gdb_signal signo
= GDB_SIGNAL_0
;
1241 /* If we paused threads momentarily, we may have stored pending
1242 events in lp->status or lp->waitstatus (see stop_wait_callback),
1243 and GDB core hasn't seen any signal for those threads.
1244 Otherwise, the last signal reported to the core is found in the
1245 thread object's stop_signal.
1247 There's a corner case that isn't handled here at present. Only
1248 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1249 stop_signal make sense as a real signal to pass to the inferior.
1250 Some catchpoint related events, like
1251 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1252 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1253 those traps are debug API (ptrace in our case) related and
1254 induced; the inferior wouldn't see them if it wasn't being
1255 traced. Hence, we should never pass them to the inferior, even
1256 when set to pass state. Since this corner case isn't handled by
1257 infrun.c when proceeding with a signal, for consistency, neither
1258 do we handle it here (or elsewhere in the file we check for
1259 signal pass state). Normally SIGTRAP isn't set to pass state, so
1260 this is really a corner case. */
1262 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
1263 signo
= GDB_SIGNAL_0
; /* a pending ptrace event, not a real signal. */
1264 else if (lp
->status
)
1265 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1266 else if (non_stop
&& !is_executing (lp
->ptid
))
1268 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1270 signo
= tp
->suspend
.stop_signal
;
1274 struct target_waitstatus last
;
1277 get_last_target_status (&last_ptid
, &last
);
1279 if (ptid_get_lwp (lp
->ptid
) == ptid_get_lwp (last_ptid
))
1281 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1283 signo
= tp
->suspend
.stop_signal
;
1289 if (signo
== GDB_SIGNAL_0
)
1291 if (debug_linux_nat
)
1292 fprintf_unfiltered (gdb_stdlog
,
1293 "GPT: lwp %s has no pending signal\n",
1294 target_pid_to_str (lp
->ptid
));
1296 else if (!signal_pass_state (signo
))
1298 if (debug_linux_nat
)
1299 fprintf_unfiltered (gdb_stdlog
,
1300 "GPT: lwp %s had signal %s, "
1301 "but it is in no pass state\n",
1302 target_pid_to_str (lp
->ptid
),
1303 gdb_signal_to_string (signo
));
1307 *status
= W_STOPCODE (gdb_signal_to_host (signo
));
1309 if (debug_linux_nat
)
1310 fprintf_unfiltered (gdb_stdlog
,
1311 "GPT: lwp %s has pending signal %s\n",
1312 target_pid_to_str (lp
->ptid
),
1313 gdb_signal_to_string (signo
));
1320 detach_callback (struct lwp_info
*lp
, void *data
)
1322 gdb_assert (lp
->status
== 0 || WIFSTOPPED (lp
->status
));
1324 if (debug_linux_nat
&& lp
->status
)
1325 fprintf_unfiltered (gdb_stdlog
, "DC: Pending %s for %s on detach.\n",
1326 strsignal (WSTOPSIG (lp
->status
)),
1327 target_pid_to_str (lp
->ptid
));
1329 /* If there is a pending SIGSTOP, get rid of it. */
1332 if (debug_linux_nat
)
1333 fprintf_unfiltered (gdb_stdlog
,
1334 "DC: Sending SIGCONT to %s\n",
1335 target_pid_to_str (lp
->ptid
));
1337 kill_lwp (ptid_get_lwp (lp
->ptid
), SIGCONT
);
1341 /* We don't actually detach from the LWP that has an id equal to the
1342 overall process id just yet. */
1343 if (ptid_get_lwp (lp
->ptid
) != ptid_get_pid (lp
->ptid
))
1347 /* Pass on any pending signal for this LWP. */
1348 get_pending_status (lp
, &status
);
1350 if (linux_nat_prepare_to_resume
!= NULL
)
1351 linux_nat_prepare_to_resume (lp
);
1353 if (ptrace (PTRACE_DETACH
, ptid_get_lwp (lp
->ptid
), 0,
1354 WSTOPSIG (status
)) < 0)
1355 error (_("Can't detach %s: %s"), target_pid_to_str (lp
->ptid
),
1356 safe_strerror (errno
));
1358 if (debug_linux_nat
)
1359 fprintf_unfiltered (gdb_stdlog
,
1360 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1361 target_pid_to_str (lp
->ptid
),
1362 strsignal (WSTOPSIG (status
)));
1364 delete_lwp (lp
->ptid
);
1371 linux_nat_detach (struct target_ops
*ops
, const char *args
, int from_tty
)
1375 struct lwp_info
*main_lwp
;
1377 pid
= ptid_get_pid (inferior_ptid
);
1379 /* Don't unregister from the event loop, as there may be other
1380 inferiors running. */
1382 /* Stop all threads before detaching. ptrace requires that the
1383 thread is stopped to sucessfully detach. */
1384 iterate_over_lwps (pid_to_ptid (pid
), stop_callback
, NULL
);
1385 /* ... and wait until all of them have reported back that
1386 they're no longer running. */
1387 iterate_over_lwps (pid_to_ptid (pid
), stop_wait_callback
, NULL
);
1389 iterate_over_lwps (pid_to_ptid (pid
), detach_callback
, NULL
);
1391 /* Only the initial process should be left right now. */
1392 gdb_assert (num_lwps (ptid_get_pid (inferior_ptid
)) == 1);
1394 main_lwp
= find_lwp_pid (pid_to_ptid (pid
));
1396 /* Pass on any pending signal for the last LWP. */
1397 if ((args
== NULL
|| *args
== '\0')
1398 && get_pending_status (main_lwp
, &status
) != -1
1399 && WIFSTOPPED (status
))
1403 /* Put the signal number in ARGS so that inf_ptrace_detach will
1404 pass it along with PTRACE_DETACH. */
1406 xsnprintf (tem
, 8, "%d", (int) WSTOPSIG (status
));
1408 if (debug_linux_nat
)
1409 fprintf_unfiltered (gdb_stdlog
,
1410 "LND: Sending signal %s to %s\n",
1412 target_pid_to_str (main_lwp
->ptid
));
1415 if (linux_nat_prepare_to_resume
!= NULL
)
1416 linux_nat_prepare_to_resume (main_lwp
);
1417 delete_lwp (main_lwp
->ptid
);
1419 if (forks_exist_p ())
1421 /* Multi-fork case. The current inferior_ptid is being detached
1422 from, but there are other viable forks to debug. Detach from
1423 the current fork, and context-switch to the first
1425 linux_fork_detach (args
, from_tty
);
1428 linux_ops
->to_detach (ops
, args
, from_tty
);
1434 resume_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1438 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
1440 if (inf
->vfork_child
!= NULL
)
1442 if (debug_linux_nat
)
1443 fprintf_unfiltered (gdb_stdlog
,
1444 "RC: Not resuming %s (vfork parent)\n",
1445 target_pid_to_str (lp
->ptid
));
1447 else if (lp
->status
== 0
1448 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
1450 if (debug_linux_nat
)
1451 fprintf_unfiltered (gdb_stdlog
,
1452 "RC: Resuming sibling %s, %s, %s\n",
1453 target_pid_to_str (lp
->ptid
),
1454 (signo
!= GDB_SIGNAL_0
1455 ? strsignal (gdb_signal_to_host (signo
))
1457 step
? "step" : "resume");
1459 if (linux_nat_prepare_to_resume
!= NULL
)
1460 linux_nat_prepare_to_resume (lp
);
1461 linux_ops
->to_resume (linux_ops
,
1462 pid_to_ptid (ptid_get_lwp (lp
->ptid
)),
1466 lp
->stopped_by_watchpoint
= 0;
1470 if (debug_linux_nat
)
1471 fprintf_unfiltered (gdb_stdlog
,
1472 "RC: Not resuming sibling %s (has pending)\n",
1473 target_pid_to_str (lp
->ptid
));
1478 if (debug_linux_nat
)
1479 fprintf_unfiltered (gdb_stdlog
,
1480 "RC: Not resuming sibling %s (not stopped)\n",
1481 target_pid_to_str (lp
->ptid
));
1485 /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing.
1486 Resume LWP with the last stop signal, if it is in pass state. */
1489 linux_nat_resume_callback (struct lwp_info
*lp
, void *except
)
1491 enum gdb_signal signo
= GDB_SIGNAL_0
;
1498 struct thread_info
*thread
;
1500 thread
= find_thread_ptid (lp
->ptid
);
1503 signo
= thread
->suspend
.stop_signal
;
1504 thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
1508 resume_lwp (lp
, 0, signo
);
1513 resume_clear_callback (struct lwp_info
*lp
, void *data
)
1516 lp
->last_resume_kind
= resume_stop
;
1521 resume_set_callback (struct lwp_info
*lp
, void *data
)
1524 lp
->last_resume_kind
= resume_continue
;
1529 linux_nat_resume (struct target_ops
*ops
,
1530 ptid_t ptid
, int step
, enum gdb_signal signo
)
1532 struct lwp_info
*lp
;
1535 if (debug_linux_nat
)
1536 fprintf_unfiltered (gdb_stdlog
,
1537 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1538 step
? "step" : "resume",
1539 target_pid_to_str (ptid
),
1540 (signo
!= GDB_SIGNAL_0
1541 ? strsignal (gdb_signal_to_host (signo
)) : "0"),
1542 target_pid_to_str (inferior_ptid
));
1544 /* A specific PTID means `step only this process id'. */
1545 resume_many
= (ptid_equal (minus_one_ptid
, ptid
)
1546 || ptid_is_pid (ptid
));
1548 /* Mark the lwps we're resuming as resumed. */
1549 iterate_over_lwps (ptid
, resume_set_callback
, NULL
);
1551 /* See if it's the current inferior that should be handled
1554 lp
= find_lwp_pid (inferior_ptid
);
1556 lp
= find_lwp_pid (ptid
);
1557 gdb_assert (lp
!= NULL
);
1559 /* Remember if we're stepping. */
1561 lp
->last_resume_kind
= step
? resume_step
: resume_continue
;
1563 /* If we have a pending wait status for this thread, there is no
1564 point in resuming the process. But first make sure that
1565 linux_nat_wait won't preemptively handle the event - we
1566 should never take this short-circuit if we are going to
1567 leave LP running, since we have skipped resuming all the
1568 other threads. This bit of code needs to be synchronized
1569 with linux_nat_wait. */
1571 if (lp
->status
&& WIFSTOPPED (lp
->status
))
1574 && WSTOPSIG (lp
->status
)
1575 && sigismember (&pass_mask
, WSTOPSIG (lp
->status
)))
1577 if (debug_linux_nat
)
1578 fprintf_unfiltered (gdb_stdlog
,
1579 "LLR: Not short circuiting for ignored "
1580 "status 0x%x\n", lp
->status
);
1582 /* FIXME: What should we do if we are supposed to continue
1583 this thread with a signal? */
1584 gdb_assert (signo
== GDB_SIGNAL_0
);
1585 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1590 if (lp
->status
|| lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
1592 /* FIXME: What should we do if we are supposed to continue
1593 this thread with a signal? */
1594 gdb_assert (signo
== GDB_SIGNAL_0
);
1596 if (debug_linux_nat
)
1597 fprintf_unfiltered (gdb_stdlog
,
1598 "LLR: Short circuiting for status 0x%x\n",
1601 if (target_can_async_p ())
1603 target_async (inferior_event_handler
, 0);
1604 /* Tell the event loop we have something to process. */
1611 iterate_over_lwps (ptid
, linux_nat_resume_callback
, lp
);
1613 /* Convert to something the lower layer understands. */
1614 ptid
= pid_to_ptid (ptid_get_lwp (lp
->ptid
));
1616 if (linux_nat_prepare_to_resume
!= NULL
)
1617 linux_nat_prepare_to_resume (lp
);
1618 linux_ops
->to_resume (linux_ops
, ptid
, step
, signo
);
1619 lp
->stopped_by_watchpoint
= 0;
1622 if (debug_linux_nat
)
1623 fprintf_unfiltered (gdb_stdlog
,
1624 "LLR: %s %s, %s (resume event thread)\n",
1625 step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1626 target_pid_to_str (ptid
),
1627 (signo
!= GDB_SIGNAL_0
1628 ? strsignal (gdb_signal_to_host (signo
)) : "0"));
1630 if (target_can_async_p ())
1631 target_async (inferior_event_handler
, 0);
1634 /* Send a signal to an LWP. */
1637 kill_lwp (int lwpid
, int signo
)
1639 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1640 fails, then we are not using nptl threads and we should be using kill. */
1642 #ifdef HAVE_TKILL_SYSCALL
1644 static int tkill_failed
;
1651 ret
= syscall (__NR_tkill
, lwpid
, signo
);
1652 if (errno
!= ENOSYS
)
1659 return kill (lwpid
, signo
);
1662 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1663 event, check if the core is interested in it: if not, ignore the
1664 event, and keep waiting; otherwise, we need to toggle the LWP's
1665 syscall entry/exit status, since the ptrace event itself doesn't
1666 indicate it, and report the trap to higher layers. */
1669 linux_handle_syscall_trap (struct lwp_info
*lp
, int stopping
)
1671 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1672 struct gdbarch
*gdbarch
= target_thread_architecture (lp
->ptid
);
1673 int syscall_number
= (int) gdbarch_get_syscall_number (gdbarch
, lp
->ptid
);
1677 /* If we're stopping threads, there's a SIGSTOP pending, which
1678 makes it so that the LWP reports an immediate syscall return,
1679 followed by the SIGSTOP. Skip seeing that "return" using
1680 PTRACE_CONT directly, and let stop_wait_callback collect the
1681 SIGSTOP. Later when the thread is resumed, a new syscall
1682 entry event. If we didn't do this (and returned 0), we'd
1683 leave a syscall entry pending, and our caller, by using
1684 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1685 itself. Later, when the user re-resumes this LWP, we'd see
1686 another syscall entry event and we'd mistake it for a return.
1688 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1689 (leaving immediately with LWP->signalled set, without issuing
1690 a PTRACE_CONT), it would still be problematic to leave this
1691 syscall enter pending, as later when the thread is resumed,
1692 it would then see the same syscall exit mentioned above,
1693 followed by the delayed SIGSTOP, while the syscall didn't
1694 actually get to execute. It seems it would be even more
1695 confusing to the user. */
1697 if (debug_linux_nat
)
1698 fprintf_unfiltered (gdb_stdlog
,
1699 "LHST: ignoring syscall %d "
1700 "for LWP %ld (stopping threads), "
1701 "resuming with PTRACE_CONT for SIGSTOP\n",
1703 ptid_get_lwp (lp
->ptid
));
1705 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1706 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
1711 if (catch_syscall_enabled ())
1713 /* Always update the entry/return state, even if this particular
1714 syscall isn't interesting to the core now. In async mode,
1715 the user could install a new catchpoint for this syscall
1716 between syscall enter/return, and we'll need to know to
1717 report a syscall return if that happens. */
1718 lp
->syscall_state
= (lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1719 ? TARGET_WAITKIND_SYSCALL_RETURN
1720 : TARGET_WAITKIND_SYSCALL_ENTRY
);
1722 if (catching_syscall_number (syscall_number
))
1724 /* Alright, an event to report. */
1725 ourstatus
->kind
= lp
->syscall_state
;
1726 ourstatus
->value
.syscall_number
= syscall_number
;
1728 if (debug_linux_nat
)
1729 fprintf_unfiltered (gdb_stdlog
,
1730 "LHST: stopping for %s of syscall %d"
1733 == TARGET_WAITKIND_SYSCALL_ENTRY
1734 ? "entry" : "return",
1736 ptid_get_lwp (lp
->ptid
));
1740 if (debug_linux_nat
)
1741 fprintf_unfiltered (gdb_stdlog
,
1742 "LHST: ignoring %s of syscall %d "
1744 lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1745 ? "entry" : "return",
1747 ptid_get_lwp (lp
->ptid
));
1751 /* If we had been syscall tracing, and hence used PT_SYSCALL
1752 before on this LWP, it could happen that the user removes all
1753 syscall catchpoints before we get to process this event.
1754 There are two noteworthy issues here:
1756 - When stopped at a syscall entry event, resuming with
1757 PT_STEP still resumes executing the syscall and reports a
1760 - Only PT_SYSCALL catches syscall enters. If we last
1761 single-stepped this thread, then this event can't be a
1762 syscall enter. If we last single-stepped this thread, this
1763 has to be a syscall exit.
1765 The points above mean that the next resume, be it PT_STEP or
1766 PT_CONTINUE, can not trigger a syscall trace event. */
1767 if (debug_linux_nat
)
1768 fprintf_unfiltered (gdb_stdlog
,
1769 "LHST: caught syscall event "
1770 "with no syscall catchpoints."
1771 " %d for LWP %ld, ignoring\n",
1773 ptid_get_lwp (lp
->ptid
));
1774 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1777 /* The core isn't interested in this event. For efficiency, avoid
1778 stopping all threads only to have the core resume them all again.
1779 Since we're not stopping threads, if we're still syscall tracing
1780 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1781 subsequent syscall. Simply resume using the inf-ptrace layer,
1782 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1784 /* Note that gdbarch_get_syscall_number may access registers, hence
1786 registers_changed ();
1787 if (linux_nat_prepare_to_resume
!= NULL
)
1788 linux_nat_prepare_to_resume (lp
);
1789 linux_ops
->to_resume (linux_ops
, pid_to_ptid (ptid_get_lwp (lp
->ptid
)),
1790 lp
->step
, GDB_SIGNAL_0
);
1795 /* Handle a GNU/Linux extended wait response. If we see a clone
1796 event, we need to add the new LWP to our list (and not report the
1797 trap to higher layers). This function returns non-zero if the
1798 event should be ignored and we should wait again. If STOPPING is
1799 true, the new LWP remains stopped, otherwise it is continued. */
1802 linux_handle_extended_wait (struct lwp_info
*lp
, int status
,
1805 int pid
= ptid_get_lwp (lp
->ptid
);
1806 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1807 int event
= linux_ptrace_get_extended_event (status
);
1809 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
1810 || event
== PTRACE_EVENT_CLONE
)
1812 unsigned long new_pid
;
1815 ptrace (PTRACE_GETEVENTMSG
, pid
, 0, &new_pid
);
1817 /* If we haven't already seen the new PID stop, wait for it now. */
1818 if (! pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
1820 /* The new child has a pending SIGSTOP. We can't affect it until it
1821 hits the SIGSTOP, but we're already attached. */
1822 ret
= my_waitpid (new_pid
, &status
,
1823 (event
== PTRACE_EVENT_CLONE
) ? __WCLONE
: 0);
1825 perror_with_name (_("waiting for new child"));
1826 else if (ret
!= new_pid
)
1827 internal_error (__FILE__
, __LINE__
,
1828 _("wait returned unexpected PID %d"), ret
);
1829 else if (!WIFSTOPPED (status
))
1830 internal_error (__FILE__
, __LINE__
,
1831 _("wait returned unexpected status 0x%x"), status
);
1834 ourstatus
->value
.related_pid
= ptid_build (new_pid
, new_pid
, 0);
1836 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
)
1838 /* The arch-specific native code may need to know about new
1839 forks even if those end up never mapped to an
1841 if (linux_nat_new_fork
!= NULL
)
1842 linux_nat_new_fork (lp
, new_pid
);
1845 if (event
== PTRACE_EVENT_FORK
1846 && linux_fork_checkpointing_p (ptid_get_pid (lp
->ptid
)))
1848 /* Handle checkpointing by linux-fork.c here as a special
1849 case. We don't want the follow-fork-mode or 'catch fork'
1850 to interfere with this. */
1852 /* This won't actually modify the breakpoint list, but will
1853 physically remove the breakpoints from the child. */
1854 detach_breakpoints (ptid_build (new_pid
, new_pid
, 0));
1856 /* Retain child fork in ptrace (stopped) state. */
1857 if (!find_fork_pid (new_pid
))
1860 /* Report as spurious, so that infrun doesn't want to follow
1861 this fork. We're actually doing an infcall in
1863 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
1865 /* Report the stop to the core. */
1869 if (event
== PTRACE_EVENT_FORK
)
1870 ourstatus
->kind
= TARGET_WAITKIND_FORKED
;
1871 else if (event
== PTRACE_EVENT_VFORK
)
1872 ourstatus
->kind
= TARGET_WAITKIND_VFORKED
;
1875 struct lwp_info
*new_lp
;
1877 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
1879 if (debug_linux_nat
)
1880 fprintf_unfiltered (gdb_stdlog
,
1881 "LHEW: Got clone event "
1882 "from LWP %d, new child is LWP %ld\n",
1885 new_lp
= add_lwp (ptid_build (ptid_get_pid (lp
->ptid
), new_pid
, 0));
1887 new_lp
->stopped
= 1;
1889 if (WSTOPSIG (status
) != SIGSTOP
)
1891 /* This can happen if someone starts sending signals to
1892 the new thread before it gets a chance to run, which
1893 have a lower number than SIGSTOP (e.g. SIGUSR1).
1894 This is an unlikely case, and harder to handle for
1895 fork / vfork than for clone, so we do not try - but
1896 we handle it for clone events here. We'll send
1897 the other signal on to the thread below. */
1899 new_lp
->signalled
= 1;
1903 struct thread_info
*tp
;
1905 /* When we stop for an event in some other thread, and
1906 pull the thread list just as this thread has cloned,
1907 we'll have seen the new thread in the thread_db list
1908 before handling the CLONE event (glibc's
1909 pthread_create adds the new thread to the thread list
1910 before clone'ing, and has the kernel fill in the
1911 thread's tid on the clone call with
1912 CLONE_PARENT_SETTID). If that happened, and the core
1913 had requested the new thread to stop, we'll have
1914 killed it with SIGSTOP. But since SIGSTOP is not an
1915 RT signal, it can only be queued once. We need to be
1916 careful to not resume the LWP if we wanted it to
1917 stop. In that case, we'll leave the SIGSTOP pending.
1918 It will later be reported as GDB_SIGNAL_0. */
1919 tp
= find_thread_ptid (new_lp
->ptid
);
1920 if (tp
!= NULL
&& tp
->stop_requested
)
1921 new_lp
->last_resume_kind
= resume_stop
;
1928 /* Add the new thread to GDB's lists as soon as possible
1931 1) the frontend doesn't have to wait for a stop to
1934 2) we tag it with the correct running state. */
1936 /* If the thread_db layer is active, let it know about
1937 this new thread, and add it to GDB's list. */
1938 if (!thread_db_attach_lwp (new_lp
->ptid
))
1940 /* We're not using thread_db. Add it to GDB's
1942 target_post_attach (ptid_get_lwp (new_lp
->ptid
));
1943 add_thread (new_lp
->ptid
);
1948 set_running (new_lp
->ptid
, 1);
1949 set_executing (new_lp
->ptid
, 1);
1950 /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced
1952 new_lp
->last_resume_kind
= resume_continue
;
1958 /* We created NEW_LP so it cannot yet contain STATUS. */
1959 gdb_assert (new_lp
->status
== 0);
1961 /* Save the wait status to report later. */
1962 if (debug_linux_nat
)
1963 fprintf_unfiltered (gdb_stdlog
,
1964 "LHEW: waitpid of new LWP %ld, "
1965 "saving status %s\n",
1966 (long) ptid_get_lwp (new_lp
->ptid
),
1967 status_to_str (status
));
1968 new_lp
->status
= status
;
1971 /* Note the need to use the low target ops to resume, to
1972 handle resuming with PT_SYSCALL if we have syscall
1976 new_lp
->resumed
= 1;
1980 gdb_assert (new_lp
->last_resume_kind
== resume_continue
);
1981 if (debug_linux_nat
)
1982 fprintf_unfiltered (gdb_stdlog
,
1983 "LHEW: resuming new LWP %ld\n",
1984 ptid_get_lwp (new_lp
->ptid
));
1985 if (linux_nat_prepare_to_resume
!= NULL
)
1986 linux_nat_prepare_to_resume (new_lp
);
1987 linux_ops
->to_resume (linux_ops
, pid_to_ptid (new_pid
),
1989 new_lp
->stopped
= 0;
1993 if (debug_linux_nat
)
1994 fprintf_unfiltered (gdb_stdlog
,
1995 "LHEW: resuming parent LWP %d\n", pid
);
1996 if (linux_nat_prepare_to_resume
!= NULL
)
1997 linux_nat_prepare_to_resume (lp
);
1998 linux_ops
->to_resume (linux_ops
,
1999 pid_to_ptid (ptid_get_lwp (lp
->ptid
)),
2008 if (event
== PTRACE_EVENT_EXEC
)
2010 if (debug_linux_nat
)
2011 fprintf_unfiltered (gdb_stdlog
,
2012 "LHEW: Got exec event from LWP %ld\n",
2013 ptid_get_lwp (lp
->ptid
));
2015 ourstatus
->kind
= TARGET_WAITKIND_EXECD
;
2016 ourstatus
->value
.execd_pathname
2017 = xstrdup (linux_child_pid_to_exec_file (NULL
, pid
));
2022 if (event
== PTRACE_EVENT_VFORK_DONE
)
2024 if (current_inferior ()->waiting_for_vfork_done
)
2026 if (debug_linux_nat
)
2027 fprintf_unfiltered (gdb_stdlog
,
2028 "LHEW: Got expected PTRACE_EVENT_"
2029 "VFORK_DONE from LWP %ld: stopping\n",
2030 ptid_get_lwp (lp
->ptid
));
2032 ourstatus
->kind
= TARGET_WAITKIND_VFORK_DONE
;
2036 if (debug_linux_nat
)
2037 fprintf_unfiltered (gdb_stdlog
,
2038 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2039 "from LWP %ld: resuming\n",
2040 ptid_get_lwp (lp
->ptid
));
2041 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
2045 internal_error (__FILE__
, __LINE__
,
2046 _("unknown ptrace event %d"), event
);
2049 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2053 wait_lwp (struct lwp_info
*lp
)
2057 int thread_dead
= 0;
2060 gdb_assert (!lp
->stopped
);
2061 gdb_assert (lp
->status
== 0);
2063 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2064 block_child_signals (&prev_mask
);
2068 /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind
2069 was right and we should just call sigsuspend. */
2071 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), &status
, WNOHANG
);
2072 if (pid
== -1 && errno
== ECHILD
)
2073 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), &status
, __WCLONE
| WNOHANG
);
2074 if (pid
== -1 && errno
== ECHILD
)
2076 /* The thread has previously exited. We need to delete it
2077 now because, for some vendor 2.4 kernels with NPTL
2078 support backported, there won't be an exit event unless
2079 it is the main thread. 2.6 kernels will report an exit
2080 event for each thread that exits, as expected. */
2082 if (debug_linux_nat
)
2083 fprintf_unfiltered (gdb_stdlog
, "WL: %s vanished.\n",
2084 target_pid_to_str (lp
->ptid
));
2089 /* Bugs 10970, 12702.
2090 Thread group leader may have exited in which case we'll lock up in
2091 waitpid if there are other threads, even if they are all zombies too.
2092 Basically, we're not supposed to use waitpid this way.
2093 __WCLONE is not applicable for the leader so we can't use that.
2094 LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED
2095 process; it gets ESRCH both for the zombie and for running processes.
2097 As a workaround, check if we're waiting for the thread group leader and
2098 if it's a zombie, and avoid calling waitpid if it is.
2100 This is racy, what if the tgl becomes a zombie right after we check?
2101 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2102 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2104 if (ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
)
2105 && linux_proc_pid_is_zombie (ptid_get_lwp (lp
->ptid
)))
2108 if (debug_linux_nat
)
2109 fprintf_unfiltered (gdb_stdlog
,
2110 "WL: Thread group leader %s vanished.\n",
2111 target_pid_to_str (lp
->ptid
));
2115 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2116 get invoked despite our caller had them intentionally blocked by
2117 block_child_signals. This is sensitive only to the loop of
2118 linux_nat_wait_1 and there if we get called my_waitpid gets called
2119 again before it gets to sigsuspend so we can safely let the handlers
2120 get executed here. */
2122 if (debug_linux_nat
)
2123 fprintf_unfiltered (gdb_stdlog
, "WL: about to sigsuspend\n");
2124 sigsuspend (&suspend_mask
);
2127 restore_child_signals_mask (&prev_mask
);
2131 gdb_assert (pid
== ptid_get_lwp (lp
->ptid
));
2133 if (debug_linux_nat
)
2135 fprintf_unfiltered (gdb_stdlog
,
2136 "WL: waitpid %s received %s\n",
2137 target_pid_to_str (lp
->ptid
),
2138 status_to_str (status
));
2141 /* Check if the thread has exited. */
2142 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2145 if (debug_linux_nat
)
2146 fprintf_unfiltered (gdb_stdlog
, "WL: %s exited.\n",
2147 target_pid_to_str (lp
->ptid
));
2157 gdb_assert (WIFSTOPPED (status
));
2160 /* Handle GNU/Linux's syscall SIGTRAPs. */
2161 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2163 /* No longer need the sysgood bit. The ptrace event ends up
2164 recorded in lp->waitstatus if we care for it. We can carry
2165 on handling the event like a regular SIGTRAP from here
2167 status
= W_STOPCODE (SIGTRAP
);
2168 if (linux_handle_syscall_trap (lp
, 1))
2169 return wait_lwp (lp
);
2172 /* Handle GNU/Linux's extended waitstatus for trace events. */
2173 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
2174 && linux_is_extended_waitstatus (status
))
2176 if (debug_linux_nat
)
2177 fprintf_unfiltered (gdb_stdlog
,
2178 "WL: Handling extended status 0x%06x\n",
2180 if (linux_handle_extended_wait (lp
, status
, 1))
2181 return wait_lwp (lp
);
2187 /* Send a SIGSTOP to LP. */
2190 stop_callback (struct lwp_info
*lp
, void *data
)
2192 if (!lp
->stopped
&& !lp
->signalled
)
2196 if (debug_linux_nat
)
2198 fprintf_unfiltered (gdb_stdlog
,
2199 "SC: kill %s **<SIGSTOP>**\n",
2200 target_pid_to_str (lp
->ptid
));
2203 ret
= kill_lwp (ptid_get_lwp (lp
->ptid
), SIGSTOP
);
2204 if (debug_linux_nat
)
2206 fprintf_unfiltered (gdb_stdlog
,
2207 "SC: lwp kill %d %s\n",
2209 errno
? safe_strerror (errno
) : "ERRNO-OK");
2213 gdb_assert (lp
->status
== 0);
2219 /* Request a stop on LWP. */
2222 linux_stop_lwp (struct lwp_info
*lwp
)
2224 stop_callback (lwp
, NULL
);
2227 /* Return non-zero if LWP PID has a pending SIGINT. */
2230 linux_nat_has_pending_sigint (int pid
)
2232 sigset_t pending
, blocked
, ignored
;
2234 linux_proc_pending_signals (pid
, &pending
, &blocked
, &ignored
);
2236 if (sigismember (&pending
, SIGINT
)
2237 && !sigismember (&ignored
, SIGINT
))
2243 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2246 set_ignore_sigint (struct lwp_info
*lp
, void *data
)
2248 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2249 flag to consume the next one. */
2250 if (lp
->stopped
&& lp
->status
!= 0 && WIFSTOPPED (lp
->status
)
2251 && WSTOPSIG (lp
->status
) == SIGINT
)
2254 lp
->ignore_sigint
= 1;
2259 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2260 This function is called after we know the LWP has stopped; if the LWP
2261 stopped before the expected SIGINT was delivered, then it will never have
2262 arrived. Also, if the signal was delivered to a shared queue and consumed
2263 by a different thread, it will never be delivered to this LWP. */
2266 maybe_clear_ignore_sigint (struct lwp_info
*lp
)
2268 if (!lp
->ignore_sigint
)
2271 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp
->ptid
)))
2273 if (debug_linux_nat
)
2274 fprintf_unfiltered (gdb_stdlog
,
2275 "MCIS: Clearing bogus flag for %s\n",
2276 target_pid_to_str (lp
->ptid
));
2277 lp
->ignore_sigint
= 0;
2281 /* Fetch the possible triggered data watchpoint info and store it in
2284 On some archs, like x86, that use debug registers to set
2285 watchpoints, it's possible that the way to know which watched
2286 address trapped, is to check the register that is used to select
2287 which address to watch. Problem is, between setting the watchpoint
2288 and reading back which data address trapped, the user may change
2289 the set of watchpoints, and, as a consequence, GDB changes the
2290 debug registers in the inferior. To avoid reading back a stale
2291 stopped-data-address when that happens, we cache in LP the fact
2292 that a watchpoint trapped, and the corresponding data address, as
2293 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2294 registers meanwhile, we have the cached data we can rely on. */
2297 save_sigtrap (struct lwp_info
*lp
)
2299 struct cleanup
*old_chain
;
2301 if (linux_ops
->to_stopped_by_watchpoint
== NULL
)
2303 lp
->stopped_by_watchpoint
= 0;
2307 old_chain
= save_inferior_ptid ();
2308 inferior_ptid
= lp
->ptid
;
2310 lp
->stopped_by_watchpoint
= linux_ops
->to_stopped_by_watchpoint (linux_ops
);
2312 if (lp
->stopped_by_watchpoint
)
2314 if (linux_ops
->to_stopped_data_address
!= NULL
)
2315 lp
->stopped_data_address_p
=
2316 linux_ops
->to_stopped_data_address (¤t_target
,
2317 &lp
->stopped_data_address
);
2319 lp
->stopped_data_address_p
= 0;
2322 do_cleanups (old_chain
);
2325 /* See save_sigtrap. */
2328 linux_nat_stopped_by_watchpoint (struct target_ops
*ops
)
2330 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2332 gdb_assert (lp
!= NULL
);
2334 return lp
->stopped_by_watchpoint
;
2338 linux_nat_stopped_data_address (struct target_ops
*ops
, CORE_ADDR
*addr_p
)
2340 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2342 gdb_assert (lp
!= NULL
);
2344 *addr_p
= lp
->stopped_data_address
;
2346 return lp
->stopped_data_address_p
;
2349 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2352 sigtrap_is_event (int status
)
2354 return WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
;
2357 /* SIGTRAP-like events recognizer. */
2359 static int (*linux_nat_status_is_event
) (int status
) = sigtrap_is_event
;
2361 /* Check for SIGTRAP-like events in LP. */
2364 linux_nat_lp_status_is_event (struct lwp_info
*lp
)
2366 /* We check for lp->waitstatus in addition to lp->status, because we can
2367 have pending process exits recorded in lp->status
2368 and W_EXITCODE(0,0) == 0. We should probably have an additional
2369 lp->status_p flag. */
2371 return (lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
2372 && linux_nat_status_is_event (lp
->status
));
2375 /* Set alternative SIGTRAP-like events recognizer. If
2376 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2380 linux_nat_set_status_is_event (struct target_ops
*t
,
2381 int (*status_is_event
) (int status
))
2383 linux_nat_status_is_event
= status_is_event
;
2386 /* Wait until LP is stopped. */
2389 stop_wait_callback (struct lwp_info
*lp
, void *data
)
2391 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
2393 /* If this is a vfork parent, bail out, it is not going to report
2394 any SIGSTOP until the vfork is done with. */
2395 if (inf
->vfork_child
!= NULL
)
2402 status
= wait_lwp (lp
);
2406 if (lp
->ignore_sigint
&& WIFSTOPPED (status
)
2407 && WSTOPSIG (status
) == SIGINT
)
2409 lp
->ignore_sigint
= 0;
2412 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
2414 if (debug_linux_nat
)
2415 fprintf_unfiltered (gdb_stdlog
,
2416 "PTRACE_CONT %s, 0, 0 (%s) "
2417 "(discarding SIGINT)\n",
2418 target_pid_to_str (lp
->ptid
),
2419 errno
? safe_strerror (errno
) : "OK");
2421 return stop_wait_callback (lp
, NULL
);
2424 maybe_clear_ignore_sigint (lp
);
2426 if (WSTOPSIG (status
) != SIGSTOP
)
2428 /* The thread was stopped with a signal other than SIGSTOP. */
2432 if (debug_linux_nat
)
2433 fprintf_unfiltered (gdb_stdlog
,
2434 "SWC: Pending event %s in %s\n",
2435 status_to_str ((int) status
),
2436 target_pid_to_str (lp
->ptid
));
2438 /* Save the sigtrap event. */
2439 lp
->status
= status
;
2440 gdb_assert (lp
->signalled
);
2444 /* We caught the SIGSTOP that we intended to catch, so
2445 there's no SIGSTOP pending. */
2447 if (debug_linux_nat
)
2448 fprintf_unfiltered (gdb_stdlog
,
2449 "SWC: Delayed SIGSTOP caught for %s.\n",
2450 target_pid_to_str (lp
->ptid
));
2452 /* Reset SIGNALLED only after the stop_wait_callback call
2453 above as it does gdb_assert on SIGNALLED. */
2461 /* Return non-zero if LP has a wait status pending. */
2464 status_callback (struct lwp_info
*lp
, void *data
)
2466 /* Only report a pending wait status if we pretend that this has
2467 indeed been resumed. */
2471 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
2473 /* A ptrace event, like PTRACE_FORK|VFORK|EXEC, syscall event,
2474 or a pending process exit. Note that `W_EXITCODE(0,0) ==
2475 0', so a clean process exit can not be stored pending in
2476 lp->status, it is indistinguishable from
2477 no-pending-status. */
2481 if (lp
->status
!= 0)
2487 /* Return non-zero if LP isn't stopped. */
2490 running_callback (struct lwp_info
*lp
, void *data
)
2492 return (!lp
->stopped
2493 || ((lp
->status
!= 0
2494 || lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
2498 /* Count the LWP's that have had events. */
2501 count_events_callback (struct lwp_info
*lp
, void *data
)
2505 gdb_assert (count
!= NULL
);
2507 /* Count only resumed LWPs that have a SIGTRAP event pending. */
2508 if (lp
->resumed
&& linux_nat_lp_status_is_event (lp
))
2514 /* Select the LWP (if any) that is currently being single-stepped. */
2517 select_singlestep_lwp_callback (struct lwp_info
*lp
, void *data
)
2519 if (lp
->last_resume_kind
== resume_step
2526 /* Select the Nth LWP that has had a SIGTRAP event. */
2529 select_event_lwp_callback (struct lwp_info
*lp
, void *data
)
2531 int *selector
= data
;
2533 gdb_assert (selector
!= NULL
);
2535 /* Select only resumed LWPs that have a SIGTRAP event pending. */
2536 if (lp
->resumed
&& linux_nat_lp_status_is_event (lp
))
2537 if ((*selector
)-- == 0)
2544 cancel_breakpoint (struct lwp_info
*lp
)
2546 /* Arrange for a breakpoint to be hit again later. We don't keep
2547 the SIGTRAP status and don't forward the SIGTRAP signal to the
2548 LWP. We will handle the current event, eventually we will resume
2549 this LWP, and this breakpoint will trap again.
2551 If we do not do this, then we run the risk that the user will
2552 delete or disable the breakpoint, but the LWP will have already
2555 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
2556 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
2559 pc
= regcache_read_pc (regcache
) - target_decr_pc_after_break (gdbarch
);
2560 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
2562 if (debug_linux_nat
)
2563 fprintf_unfiltered (gdb_stdlog
,
2564 "CB: Push back breakpoint for %s\n",
2565 target_pid_to_str (lp
->ptid
));
2567 /* Back up the PC if necessary. */
2568 if (target_decr_pc_after_break (gdbarch
))
2569 regcache_write_pc (regcache
, pc
);
2577 cancel_breakpoints_callback (struct lwp_info
*lp
, void *data
)
2579 struct lwp_info
*event_lp
= data
;
2581 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
2585 /* If a LWP other than the LWP that we're reporting an event for has
2586 hit a GDB breakpoint (as opposed to some random trap signal),
2587 then just arrange for it to hit it again later. We don't keep
2588 the SIGTRAP status and don't forward the SIGTRAP signal to the
2589 LWP. We will handle the current event, eventually we will resume
2590 all LWPs, and this one will get its breakpoint trap again.
2592 If we do not do this, then we run the risk that the user will
2593 delete or disable the breakpoint, but the LWP will have already
2596 if (linux_nat_lp_status_is_event (lp
)
2597 && cancel_breakpoint (lp
))
2598 /* Throw away the SIGTRAP. */
2604 /* Select one LWP out of those that have events pending. */
2607 select_event_lwp (ptid_t filter
, struct lwp_info
**orig_lp
, int *status
)
2610 int random_selector
;
2611 struct lwp_info
*event_lp
;
2613 /* Record the wait status for the original LWP. */
2614 (*orig_lp
)->status
= *status
;
2616 /* Give preference to any LWP that is being single-stepped. */
2617 event_lp
= iterate_over_lwps (filter
,
2618 select_singlestep_lwp_callback
, NULL
);
2619 if (event_lp
!= NULL
)
2621 if (debug_linux_nat
)
2622 fprintf_unfiltered (gdb_stdlog
,
2623 "SEL: Select single-step %s\n",
2624 target_pid_to_str (event_lp
->ptid
));
2628 /* No single-stepping LWP. Select one at random, out of those
2629 which have had SIGTRAP events. */
2631 /* First see how many SIGTRAP events we have. */
2632 iterate_over_lwps (filter
, count_events_callback
, &num_events
);
2634 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
2635 random_selector
= (int)
2636 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
2638 if (debug_linux_nat
&& num_events
> 1)
2639 fprintf_unfiltered (gdb_stdlog
,
2640 "SEL: Found %d SIGTRAP events, selecting #%d\n",
2641 num_events
, random_selector
);
2643 event_lp
= iterate_over_lwps (filter
,
2644 select_event_lwp_callback
,
2648 if (event_lp
!= NULL
)
2650 /* Switch the event LWP. */
2651 *orig_lp
= event_lp
;
2652 *status
= event_lp
->status
;
2655 /* Flush the wait status for the event LWP. */
2656 (*orig_lp
)->status
= 0;
2659 /* Return non-zero if LP has been resumed. */
2662 resumed_callback (struct lwp_info
*lp
, void *data
)
2667 /* Stop an active thread, verify it still exists, then resume it. If
2668 the thread ends up with a pending status, then it is not resumed,
2669 and *DATA (really a pointer to int), is set. */
2672 stop_and_resume_callback (struct lwp_info
*lp
, void *data
)
2674 int *new_pending_p
= data
;
2678 ptid_t ptid
= lp
->ptid
;
2680 stop_callback (lp
, NULL
);
2681 stop_wait_callback (lp
, NULL
);
2683 /* Resume if the lwp still exists, and the core wanted it
2685 lp
= find_lwp_pid (ptid
);
2688 if (lp
->last_resume_kind
== resume_stop
2691 /* The core wanted the LWP to stop. Even if it stopped
2692 cleanly (with SIGSTOP), leave the event pending. */
2693 if (debug_linux_nat
)
2694 fprintf_unfiltered (gdb_stdlog
,
2695 "SARC: core wanted LWP %ld stopped "
2696 "(leaving SIGSTOP pending)\n",
2697 ptid_get_lwp (lp
->ptid
));
2698 lp
->status
= W_STOPCODE (SIGSTOP
);
2701 if (lp
->status
== 0)
2703 if (debug_linux_nat
)
2704 fprintf_unfiltered (gdb_stdlog
,
2705 "SARC: re-resuming LWP %ld\n",
2706 ptid_get_lwp (lp
->ptid
));
2707 resume_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
2711 if (debug_linux_nat
)
2712 fprintf_unfiltered (gdb_stdlog
,
2713 "SARC: not re-resuming LWP %ld "
2715 ptid_get_lwp (lp
->ptid
));
2724 /* Check if we should go on and pass this event to common code.
2725 Return the affected lwp if we are, or NULL otherwise. If we stop
2726 all lwps temporarily, we may end up with new pending events in some
2727 other lwp. In that case set *NEW_PENDING_P to true. */
2729 static struct lwp_info
*
2730 linux_nat_filter_event (int lwpid
, int status
, int *new_pending_p
)
2732 struct lwp_info
*lp
;
2733 int event
= linux_ptrace_get_extended_event (status
);
2737 lp
= find_lwp_pid (pid_to_ptid (lwpid
));
2739 /* Check for stop events reported by a process we didn't already
2740 know about - anything not already in our LWP list.
2742 If we're expecting to receive stopped processes after
2743 fork, vfork, and clone events, then we'll just add the
2744 new one to our list and go back to waiting for the event
2745 to be reported - the stopped process might be returned
2746 from waitpid before or after the event is.
2748 But note the case of a non-leader thread exec'ing after the
2749 leader having exited, and gone from our lists. The non-leader
2750 thread changes its tid to the tgid. */
2752 if (WIFSTOPPED (status
) && lp
== NULL
2753 && (WSTOPSIG (status
) == SIGTRAP
&& event
== PTRACE_EVENT_EXEC
))
2755 /* A multi-thread exec after we had seen the leader exiting. */
2756 if (debug_linux_nat
)
2757 fprintf_unfiltered (gdb_stdlog
,
2758 "LLW: Re-adding thread group leader LWP %d.\n",
2761 lp
= add_lwp (ptid_build (lwpid
, lwpid
, 0));
2764 add_thread (lp
->ptid
);
2767 if (WIFSTOPPED (status
) && !lp
)
2769 add_to_pid_list (&stopped_pids
, lwpid
, status
);
2773 /* Make sure we don't report an event for the exit of an LWP not in
2774 our list, i.e. not part of the current process. This can happen
2775 if we detach from a program we originally forked and then it
2777 if (!WIFSTOPPED (status
) && !lp
)
2780 /* This LWP is stopped now. (And if dead, this prevents it from
2781 ever being continued.) */
2784 /* Handle GNU/Linux's syscall SIGTRAPs. */
2785 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2787 /* No longer need the sysgood bit. The ptrace event ends up
2788 recorded in lp->waitstatus if we care for it. We can carry
2789 on handling the event like a regular SIGTRAP from here
2791 status
= W_STOPCODE (SIGTRAP
);
2792 if (linux_handle_syscall_trap (lp
, 0))
2796 /* Handle GNU/Linux's extended waitstatus for trace events. */
2797 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
2798 && linux_is_extended_waitstatus (status
))
2800 if (debug_linux_nat
)
2801 fprintf_unfiltered (gdb_stdlog
,
2802 "LLW: Handling extended status 0x%06x\n",
2804 if (linux_handle_extended_wait (lp
, status
, 0))
2808 if (linux_nat_status_is_event (status
))
2811 /* Check if the thread has exited. */
2812 if ((WIFEXITED (status
) || WIFSIGNALED (status
))
2813 && num_lwps (ptid_get_pid (lp
->ptid
)) > 1)
2815 /* If this is the main thread, we must stop all threads and verify
2816 if they are still alive. This is because in the nptl thread model
2817 on Linux 2.4, there is no signal issued for exiting LWPs
2818 other than the main thread. We only get the main thread exit
2819 signal once all child threads have already exited. If we
2820 stop all the threads and use the stop_wait_callback to check
2821 if they have exited we can determine whether this signal
2822 should be ignored or whether it means the end of the debugged
2823 application, regardless of which threading model is being
2825 if (ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
))
2827 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp
->ptid
)),
2828 stop_and_resume_callback
, new_pending_p
);
2831 if (debug_linux_nat
)
2832 fprintf_unfiltered (gdb_stdlog
,
2833 "LLW: %s exited.\n",
2834 target_pid_to_str (lp
->ptid
));
2836 if (num_lwps (ptid_get_pid (lp
->ptid
)) > 1)
2838 /* If there is at least one more LWP, then the exit signal
2839 was not the end of the debugged application and should be
2846 /* Check if the current LWP has previously exited. In the nptl
2847 thread model, LWPs other than the main thread do not issue
2848 signals when they exit so we must check whenever the thread has
2849 stopped. A similar check is made in stop_wait_callback(). */
2850 if (num_lwps (ptid_get_pid (lp
->ptid
)) > 1 && !linux_thread_alive (lp
->ptid
))
2852 ptid_t ptid
= pid_to_ptid (ptid_get_pid (lp
->ptid
));
2854 if (debug_linux_nat
)
2855 fprintf_unfiltered (gdb_stdlog
,
2856 "LLW: %s exited.\n",
2857 target_pid_to_str (lp
->ptid
));
2861 /* Make sure there is at least one thread running. */
2862 gdb_assert (iterate_over_lwps (ptid
, running_callback
, NULL
));
2864 /* Discard the event. */
2868 /* Make sure we don't report a SIGSTOP that we sent ourselves in
2869 an attempt to stop an LWP. */
2871 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGSTOP
)
2873 if (debug_linux_nat
)
2874 fprintf_unfiltered (gdb_stdlog
,
2875 "LLW: Delayed SIGSTOP caught for %s.\n",
2876 target_pid_to_str (lp
->ptid
));
2880 if (lp
->last_resume_kind
!= resume_stop
)
2882 /* This is a delayed SIGSTOP. */
2884 registers_changed ();
2886 if (linux_nat_prepare_to_resume
!= NULL
)
2887 linux_nat_prepare_to_resume (lp
);
2888 linux_ops
->to_resume (linux_ops
,
2889 pid_to_ptid (ptid_get_lwp (lp
->ptid
)),
2890 lp
->step
, GDB_SIGNAL_0
);
2891 if (debug_linux_nat
)
2892 fprintf_unfiltered (gdb_stdlog
,
2893 "LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
2895 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2896 target_pid_to_str (lp
->ptid
));
2899 gdb_assert (lp
->resumed
);
2901 /* Discard the event. */
2906 /* Make sure we don't report a SIGINT that we have already displayed
2907 for another thread. */
2908 if (lp
->ignore_sigint
2909 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGINT
)
2911 if (debug_linux_nat
)
2912 fprintf_unfiltered (gdb_stdlog
,
2913 "LLW: Delayed SIGINT caught for %s.\n",
2914 target_pid_to_str (lp
->ptid
));
2916 /* This is a delayed SIGINT. */
2917 lp
->ignore_sigint
= 0;
2919 registers_changed ();
2920 if (linux_nat_prepare_to_resume
!= NULL
)
2921 linux_nat_prepare_to_resume (lp
);
2922 linux_ops
->to_resume (linux_ops
, pid_to_ptid (ptid_get_lwp (lp
->ptid
)),
2923 lp
->step
, GDB_SIGNAL_0
);
2924 if (debug_linux_nat
)
2925 fprintf_unfiltered (gdb_stdlog
,
2926 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
2928 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2929 target_pid_to_str (lp
->ptid
));
2932 gdb_assert (lp
->resumed
);
2934 /* Discard the event. */
2938 /* An interesting event. */
2940 lp
->status
= status
;
2944 /* Detect zombie thread group leaders, and "exit" them. We can't reap
2945 their exits until all other threads in the group have exited. */
2948 check_zombie_leaders (void)
2950 struct inferior
*inf
;
2954 struct lwp_info
*leader_lp
;
2959 leader_lp
= find_lwp_pid (pid_to_ptid (inf
->pid
));
2960 if (leader_lp
!= NULL
2961 /* Check if there are other threads in the group, as we may
2962 have raced with the inferior simply exiting. */
2963 && num_lwps (inf
->pid
) > 1
2964 && linux_proc_pid_is_zombie (inf
->pid
))
2966 if (debug_linux_nat
)
2967 fprintf_unfiltered (gdb_stdlog
,
2968 "CZL: Thread group leader %d zombie "
2969 "(it exited, or another thread execd).\n",
2972 /* A leader zombie can mean one of two things:
2974 - It exited, and there's an exit status pending
2975 available, or only the leader exited (not the whole
2976 program). In the latter case, we can't waitpid the
2977 leader's exit status until all other threads are gone.
2979 - There are 3 or more threads in the group, and a thread
2980 other than the leader exec'd. On an exec, the Linux
2981 kernel destroys all other threads (except the execing
2982 one) in the thread group, and resets the execing thread's
2983 tid to the tgid. No exit notification is sent for the
2984 execing thread -- from the ptracer's perspective, it
2985 appears as though the execing thread just vanishes.
2986 Until we reap all other threads except the leader and the
2987 execing thread, the leader will be zombie, and the
2988 execing thread will be in `D (disc sleep)'. As soon as
2989 all other threads are reaped, the execing thread changes
2990 it's tid to the tgid, and the previous (zombie) leader
2991 vanishes, giving place to the "new" leader. We could try
2992 distinguishing the exit and exec cases, by waiting once
2993 more, and seeing if something comes out, but it doesn't
2994 sound useful. The previous leader _does_ go away, and
2995 we'll re-add the new one once we see the exec event
2996 (which is just the same as what would happen if the
2997 previous leader did exit voluntarily before some other
3000 if (debug_linux_nat
)
3001 fprintf_unfiltered (gdb_stdlog
,
3002 "CZL: Thread group leader %d vanished.\n",
3004 exit_lwp (leader_lp
);
3010 linux_nat_wait_1 (struct target_ops
*ops
,
3011 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3014 static sigset_t prev_mask
;
3015 enum resume_kind last_resume_kind
;
3016 struct lwp_info
*lp
;
3019 if (debug_linux_nat
)
3020 fprintf_unfiltered (gdb_stdlog
, "LLW: enter\n");
3022 /* The first time we get here after starting a new inferior, we may
3023 not have added it to the LWP list yet - this is the earliest
3024 moment at which we know its PID. */
3025 if (ptid_is_pid (inferior_ptid
))
3027 /* Upgrade the main thread's ptid. */
3028 thread_change_ptid (inferior_ptid
,
3029 ptid_build (ptid_get_pid (inferior_ptid
),
3030 ptid_get_pid (inferior_ptid
), 0));
3032 lp
= add_initial_lwp (inferior_ptid
);
3036 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3037 block_child_signals (&prev_mask
);
3043 /* First check if there is a LWP with a wait status pending. */
3044 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3046 /* Any LWP in the PTID group that's been resumed will do. */
3047 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3050 if (debug_linux_nat
&& lp
->status
)
3051 fprintf_unfiltered (gdb_stdlog
,
3052 "LLW: Using pending wait status %s for %s.\n",
3053 status_to_str (lp
->status
),
3054 target_pid_to_str (lp
->ptid
));
3057 else if (ptid_lwp_p (ptid
))
3059 if (debug_linux_nat
)
3060 fprintf_unfiltered (gdb_stdlog
,
3061 "LLW: Waiting for specific LWP %s.\n",
3062 target_pid_to_str (ptid
));
3064 /* We have a specific LWP to check. */
3065 lp
= find_lwp_pid (ptid
);
3068 if (debug_linux_nat
&& lp
->status
)
3069 fprintf_unfiltered (gdb_stdlog
,
3070 "LLW: Using pending wait status %s for %s.\n",
3071 status_to_str (lp
->status
),
3072 target_pid_to_str (lp
->ptid
));
3074 /* We check for lp->waitstatus in addition to lp->status,
3075 because we can have pending process exits recorded in
3076 lp->status and W_EXITCODE(0,0) == 0. We should probably have
3077 an additional lp->status_p flag. */
3078 if (lp
->status
== 0 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
3082 if (!target_can_async_p ())
3084 /* Causes SIGINT to be passed on to the attached process. */
3088 /* But if we don't find a pending event, we'll have to wait. */
3094 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3097 - If the thread group leader exits while other threads in the
3098 thread group still exist, waitpid(TGID, ...) hangs. That
3099 waitpid won't return an exit status until the other threads
3100 in the group are reapped.
3102 - When a non-leader thread execs, that thread just vanishes
3103 without reporting an exit (so we'd hang if we waited for it
3104 explicitly in that case). The exec event is reported to
3108 lwpid
= my_waitpid (-1, &status
, __WCLONE
| WNOHANG
);
3109 if (lwpid
== 0 || (lwpid
== -1 && errno
== ECHILD
))
3110 lwpid
= my_waitpid (-1, &status
, WNOHANG
);
3112 if (debug_linux_nat
)
3113 fprintf_unfiltered (gdb_stdlog
,
3114 "LNW: waitpid(-1, ...) returned %d, %s\n",
3115 lwpid
, errno
? safe_strerror (errno
) : "ERRNO-OK");
3119 /* If this is true, then we paused LWPs momentarily, and may
3120 now have pending events to handle. */
3123 if (debug_linux_nat
)
3125 fprintf_unfiltered (gdb_stdlog
,
3126 "LLW: waitpid %ld received %s\n",
3127 (long) lwpid
, status_to_str (status
));
3130 lp
= linux_nat_filter_event (lwpid
, status
, &new_pending
);
3132 /* STATUS is now no longer valid, use LP->STATUS instead. */
3135 if (lp
&& !ptid_match (lp
->ptid
, ptid
))
3137 gdb_assert (lp
->resumed
);
3139 if (debug_linux_nat
)
3140 fprintf_unfiltered (gdb_stdlog
,
3141 "LWP %ld got an event %06x, "
3142 "leaving pending.\n",
3143 ptid_get_lwp (lp
->ptid
), lp
->status
);
3145 if (WIFSTOPPED (lp
->status
))
3147 if (WSTOPSIG (lp
->status
) != SIGSTOP
)
3149 /* Cancel breakpoint hits. The breakpoint may
3150 be removed before we fetch events from this
3151 process to report to the core. It is best
3152 not to assume the moribund breakpoints
3153 heuristic always handles these cases --- it
3154 could be too many events go through to the
3155 core before this one is handled. All-stop
3156 always cancels breakpoint hits in all
3159 && linux_nat_lp_status_is_event (lp
)
3160 && cancel_breakpoint (lp
))
3162 /* Throw away the SIGTRAP. */
3165 if (debug_linux_nat
)
3166 fprintf_unfiltered (gdb_stdlog
,
3167 "LLW: LWP %ld hit a "
3169 "waiting for another "
3172 ptid_get_lwp (lp
->ptid
));
3178 else if (WIFEXITED (lp
->status
) || WIFSIGNALED (lp
->status
))
3180 if (debug_linux_nat
)
3181 fprintf_unfiltered (gdb_stdlog
,
3182 "Process %ld exited while stopping "
3184 ptid_get_lwp (lp
->ptid
));
3186 /* This was the last lwp in the process. Since
3187 events are serialized to GDB core, and we can't
3188 report this one right now, but GDB core and the
3189 other target layers will want to be notified
3190 about the exit code/signal, leave the status
3191 pending for the next time we're able to report
3194 /* Dead LWP's aren't expected to reported a pending
3198 /* Store the pending event in the waitstatus as
3199 well, because W_EXITCODE(0,0) == 0. */
3200 store_waitstatus (&lp
->waitstatus
, lp
->status
);
3209 /* Some LWP now has a pending event. Go all the way
3210 back to check it. */
3216 /* We got an event to report to the core. */
3220 /* Retry until nothing comes out of waitpid. A single
3221 SIGCHLD can indicate more than one child stopped. */
3225 /* Check for zombie thread group leaders. Those can't be reaped
3226 until all other threads in the thread group are. */
3227 check_zombie_leaders ();
3229 /* If there are no resumed children left, bail. We'd be stuck
3230 forever in the sigsuspend call below otherwise. */
3231 if (iterate_over_lwps (ptid
, resumed_callback
, NULL
) == NULL
)
3233 if (debug_linux_nat
)
3234 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (no resumed LWP)\n");
3236 ourstatus
->kind
= TARGET_WAITKIND_NO_RESUMED
;
3238 if (!target_can_async_p ())
3239 clear_sigint_trap ();
3241 restore_child_signals_mask (&prev_mask
);
3242 return minus_one_ptid
;
3245 /* No interesting event to report to the core. */
3247 if (target_options
& TARGET_WNOHANG
)
3249 if (debug_linux_nat
)
3250 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (ignore)\n");
3252 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3253 restore_child_signals_mask (&prev_mask
);
3254 return minus_one_ptid
;
3257 /* We shouldn't end up here unless we want to try again. */
3258 gdb_assert (lp
== NULL
);
3260 /* Block until we get an event reported with SIGCHLD. */
3261 if (debug_linux_nat
)
3262 fprintf_unfiltered (gdb_stdlog
, "LNW: about to sigsuspend\n");
3263 sigsuspend (&suspend_mask
);
3266 if (!target_can_async_p ())
3267 clear_sigint_trap ();
3271 status
= lp
->status
;
3274 /* Don't report signals that GDB isn't interested in, such as
3275 signals that are neither printed nor stopped upon. Stopping all
3276 threads can be a bit time-consuming so if we want decent
3277 performance with heavily multi-threaded programs, especially when
3278 they're using a high frequency timer, we'd better avoid it if we
3281 if (WIFSTOPPED (status
))
3283 enum gdb_signal signo
= gdb_signal_from_host (WSTOPSIG (status
));
3285 /* When using hardware single-step, we need to report every signal.
3286 Otherwise, signals in pass_mask may be short-circuited. */
3288 && WSTOPSIG (status
) && sigismember (&pass_mask
, WSTOPSIG (status
)))
3290 /* FIMXE: kettenis/2001-06-06: Should we resume all threads
3291 here? It is not clear we should. GDB may not expect
3292 other threads to run. On the other hand, not resuming
3293 newly attached threads may cause an unwanted delay in
3294 getting them running. */
3295 registers_changed ();
3296 if (linux_nat_prepare_to_resume
!= NULL
)
3297 linux_nat_prepare_to_resume (lp
);
3298 linux_ops
->to_resume (linux_ops
,
3299 pid_to_ptid (ptid_get_lwp (lp
->ptid
)),
3301 if (debug_linux_nat
)
3302 fprintf_unfiltered (gdb_stdlog
,
3303 "LLW: %s %s, %s (preempt 'handle')\n",
3305 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3306 target_pid_to_str (lp
->ptid
),
3307 (signo
!= GDB_SIGNAL_0
3308 ? strsignal (gdb_signal_to_host (signo
))
3316 /* Only do the below in all-stop, as we currently use SIGINT
3317 to implement target_stop (see linux_nat_stop) in
3319 if (signo
== GDB_SIGNAL_INT
&& signal_pass_state (signo
) == 0)
3321 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3322 forwarded to the entire process group, that is, all LWPs
3323 will receive it - unless they're using CLONE_THREAD to
3324 share signals. Since we only want to report it once, we
3325 mark it as ignored for all LWPs except this one. */
3326 iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid
)),
3327 set_ignore_sigint
, NULL
);
3328 lp
->ignore_sigint
= 0;
3331 maybe_clear_ignore_sigint (lp
);
3335 /* This LWP is stopped now. */
3338 if (debug_linux_nat
)
3339 fprintf_unfiltered (gdb_stdlog
, "LLW: Candidate event %s in %s.\n",
3340 status_to_str (status
), target_pid_to_str (lp
->ptid
));
3344 /* Now stop all other LWP's ... */
3345 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
3347 /* ... and wait until all of them have reported back that
3348 they're no longer running. */
3349 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
3351 /* If we're not waiting for a specific LWP, choose an event LWP
3352 from among those that have had events. Giving equal priority
3353 to all LWPs that have had events helps prevent
3355 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3356 select_event_lwp (ptid
, &lp
, &status
);
3358 /* Now that we've selected our final event LWP, cancel any
3359 breakpoints in other LWPs that have hit a GDB breakpoint.
3360 See the comment in cancel_breakpoints_callback to find out
3362 iterate_over_lwps (minus_one_ptid
, cancel_breakpoints_callback
, lp
);
3364 /* We'll need this to determine whether to report a SIGSTOP as
3365 TARGET_WAITKIND_0. Need to take a copy because
3366 resume_clear_callback clears it. */
3367 last_resume_kind
= lp
->last_resume_kind
;
3369 /* In all-stop, from the core's perspective, all LWPs are now
3370 stopped until a new resume action is sent over. */
3371 iterate_over_lwps (minus_one_ptid
, resume_clear_callback
, NULL
);
3376 last_resume_kind
= lp
->last_resume_kind
;
3377 resume_clear_callback (lp
, NULL
);
3380 if (linux_nat_status_is_event (status
))
3382 if (debug_linux_nat
)
3383 fprintf_unfiltered (gdb_stdlog
,
3384 "LLW: trap ptid is %s.\n",
3385 target_pid_to_str (lp
->ptid
));
3388 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3390 *ourstatus
= lp
->waitstatus
;
3391 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3394 store_waitstatus (ourstatus
, status
);
3396 if (debug_linux_nat
)
3397 fprintf_unfiltered (gdb_stdlog
, "LLW: exit\n");
3399 restore_child_signals_mask (&prev_mask
);
3401 if (last_resume_kind
== resume_stop
3402 && ourstatus
->kind
== TARGET_WAITKIND_STOPPED
3403 && WSTOPSIG (status
) == SIGSTOP
)
3405 /* A thread that has been requested to stop by GDB with
3406 target_stop, and it stopped cleanly, so report as SIG0. The
3407 use of SIGSTOP is an implementation detail. */
3408 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3411 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
3412 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
3415 lp
->core
= linux_common_core_of_thread (lp
->ptid
);
3420 /* Resume LWPs that are currently stopped without any pending status
3421 to report, but are resumed from the core's perspective. */
3424 resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
)
3426 ptid_t
*wait_ptid_p
= data
;
3431 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
3433 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3434 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3435 CORE_ADDR pc
= regcache_read_pc (regcache
);
3437 gdb_assert (is_executing (lp
->ptid
));
3439 /* Don't bother if there's a breakpoint at PC that we'd hit
3440 immediately, and we're not waiting for this LWP. */
3441 if (!ptid_match (lp
->ptid
, *wait_ptid_p
))
3443 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
3447 if (debug_linux_nat
)
3448 fprintf_unfiltered (gdb_stdlog
,
3449 "RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n",
3450 target_pid_to_str (lp
->ptid
),
3451 paddress (gdbarch
, pc
),
3454 registers_changed ();
3455 if (linux_nat_prepare_to_resume
!= NULL
)
3456 linux_nat_prepare_to_resume (lp
);
3457 linux_ops
->to_resume (linux_ops
, pid_to_ptid (ptid_get_lwp (lp
->ptid
)),
3458 lp
->step
, GDB_SIGNAL_0
);
3460 lp
->stopped_by_watchpoint
= 0;
3467 linux_nat_wait (struct target_ops
*ops
,
3468 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3473 if (debug_linux_nat
)
3475 char *options_string
;
3477 options_string
= target_options_to_string (target_options
);
3478 fprintf_unfiltered (gdb_stdlog
,
3479 "linux_nat_wait: [%s], [%s]\n",
3480 target_pid_to_str (ptid
),
3482 xfree (options_string
);
3485 /* Flush the async file first. */
3486 if (target_can_async_p ())
3487 async_file_flush ();
3489 /* Resume LWPs that are currently stopped without any pending status
3490 to report, but are resumed from the core's perspective. LWPs get
3491 in this state if we find them stopping at a time we're not
3492 interested in reporting the event (target_wait on a
3493 specific_process, for example, see linux_nat_wait_1), and
3494 meanwhile the event became uninteresting. Don't bother resuming
3495 LWPs we're not going to wait for if they'd stop immediately. */
3497 iterate_over_lwps (minus_one_ptid
, resume_stopped_resumed_lwps
, &ptid
);
3499 event_ptid
= linux_nat_wait_1 (ops
, ptid
, ourstatus
, target_options
);
3501 /* If we requested any event, and something came out, assume there
3502 may be more. If we requested a specific lwp or process, also
3503 assume there may be more. */
3504 if (target_can_async_p ()
3505 && ((ourstatus
->kind
!= TARGET_WAITKIND_IGNORE
3506 && ourstatus
->kind
!= TARGET_WAITKIND_NO_RESUMED
)
3507 || !ptid_equal (ptid
, minus_one_ptid
)))
3510 /* Get ready for the next event. */
3511 if (target_can_async_p ())
3512 target_async (inferior_event_handler
, 0);
3518 kill_callback (struct lwp_info
*lp
, void *data
)
3520 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3523 kill_lwp (ptid_get_lwp (lp
->ptid
), SIGKILL
);
3524 if (debug_linux_nat
)
3526 int save_errno
= errno
;
3528 fprintf_unfiltered (gdb_stdlog
,
3529 "KC: kill (SIGKILL) %s, 0, 0 (%s)\n",
3530 target_pid_to_str (lp
->ptid
),
3531 save_errno
? safe_strerror (save_errno
) : "OK");
3534 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3537 ptrace (PTRACE_KILL
, ptid_get_lwp (lp
->ptid
), 0, 0);
3538 if (debug_linux_nat
)
3540 int save_errno
= errno
;
3542 fprintf_unfiltered (gdb_stdlog
,
3543 "KC: PTRACE_KILL %s, 0, 0 (%s)\n",
3544 target_pid_to_str (lp
->ptid
),
3545 save_errno
? safe_strerror (save_errno
) : "OK");
3552 kill_wait_callback (struct lwp_info
*lp
, void *data
)
3556 /* We must make sure that there are no pending events (delayed
3557 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3558 program doesn't interfere with any following debugging session. */
3560 /* For cloned processes we must check both with __WCLONE and
3561 without, since the exit status of a cloned process isn't reported
3567 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), NULL
, __WCLONE
);
3568 if (pid
!= (pid_t
) -1)
3570 if (debug_linux_nat
)
3571 fprintf_unfiltered (gdb_stdlog
,
3572 "KWC: wait %s received unknown.\n",
3573 target_pid_to_str (lp
->ptid
));
3574 /* The Linux kernel sometimes fails to kill a thread
3575 completely after PTRACE_KILL; that goes from the stop
3576 point in do_fork out to the one in
3577 get_signal_to_deliever and waits again. So kill it
3579 kill_callback (lp
, NULL
);
3582 while (pid
== ptid_get_lwp (lp
->ptid
));
3584 gdb_assert (pid
== -1 && errno
== ECHILD
);
3589 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), NULL
, 0);
3590 if (pid
!= (pid_t
) -1)
3592 if (debug_linux_nat
)
3593 fprintf_unfiltered (gdb_stdlog
,
3594 "KWC: wait %s received unk.\n",
3595 target_pid_to_str (lp
->ptid
));
3596 /* See the call to kill_callback above. */
3597 kill_callback (lp
, NULL
);
3600 while (pid
== ptid_get_lwp (lp
->ptid
));
3602 gdb_assert (pid
== -1 && errno
== ECHILD
);
3607 linux_nat_kill (struct target_ops
*ops
)
3609 struct target_waitstatus last
;
3613 /* If we're stopped while forking and we haven't followed yet,
3614 kill the other task. We need to do this first because the
3615 parent will be sleeping if this is a vfork. */
3617 get_last_target_status (&last_ptid
, &last
);
3619 if (last
.kind
== TARGET_WAITKIND_FORKED
3620 || last
.kind
== TARGET_WAITKIND_VFORKED
)
3622 ptrace (PT_KILL
, ptid_get_pid (last
.value
.related_pid
), 0, 0);
3625 /* Let the arch-specific native code know this process is
3627 linux_nat_forget_process (ptid_get_pid (last
.value
.related_pid
));
3630 if (forks_exist_p ())
3631 linux_fork_killall ();
3634 ptid_t ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
3636 /* Stop all threads before killing them, since ptrace requires
3637 that the thread is stopped to sucessfully PTRACE_KILL. */
3638 iterate_over_lwps (ptid
, stop_callback
, NULL
);
3639 /* ... and wait until all of them have reported back that
3640 they're no longer running. */
3641 iterate_over_lwps (ptid
, stop_wait_callback
, NULL
);
3643 /* Kill all LWP's ... */
3644 iterate_over_lwps (ptid
, kill_callback
, NULL
);
3646 /* ... and wait until we've flushed all events. */
3647 iterate_over_lwps (ptid
, kill_wait_callback
, NULL
);
3650 target_mourn_inferior ();
3654 linux_nat_mourn_inferior (struct target_ops
*ops
)
3656 int pid
= ptid_get_pid (inferior_ptid
);
3658 purge_lwp_list (pid
);
3660 if (! forks_exist_p ())
3661 /* Normal case, no other forks available. */
3662 linux_ops
->to_mourn_inferior (ops
);
3664 /* Multi-fork case. The current inferior_ptid has exited, but
3665 there are other viable forks to debug. Delete the exiting
3666 one and context-switch to the first available. */
3667 linux_fork_mourn_inferior ();
3669 /* Let the arch-specific native code know this process is gone. */
3670 linux_nat_forget_process (pid
);
3673 /* Convert a native/host siginfo object, into/from the siginfo in the
3674 layout of the inferiors' architecture. */
3677 siginfo_fixup (siginfo_t
*siginfo
, gdb_byte
*inf_siginfo
, int direction
)
3681 if (linux_nat_siginfo_fixup
!= NULL
)
3682 done
= linux_nat_siginfo_fixup (siginfo
, inf_siginfo
, direction
);
3684 /* If there was no callback, or the callback didn't do anything,
3685 then just do a straight memcpy. */
3689 memcpy (siginfo
, inf_siginfo
, sizeof (siginfo_t
));
3691 memcpy (inf_siginfo
, siginfo
, sizeof (siginfo_t
));
3695 static enum target_xfer_status
3696 linux_xfer_siginfo (struct target_ops
*ops
, enum target_object object
,
3697 const char *annex
, gdb_byte
*readbuf
,
3698 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
3699 ULONGEST
*xfered_len
)
3703 gdb_byte inf_siginfo
[sizeof (siginfo_t
)];
3705 gdb_assert (object
== TARGET_OBJECT_SIGNAL_INFO
);
3706 gdb_assert (readbuf
|| writebuf
);
3708 pid
= ptid_get_lwp (inferior_ptid
);
3710 pid
= ptid_get_pid (inferior_ptid
);
3712 if (offset
> sizeof (siginfo
))
3713 return TARGET_XFER_E_IO
;
3716 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3718 return TARGET_XFER_E_IO
;
3720 /* When GDB is built as a 64-bit application, ptrace writes into
3721 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3722 inferior with a 64-bit GDB should look the same as debugging it
3723 with a 32-bit GDB, we need to convert it. GDB core always sees
3724 the converted layout, so any read/write will have to be done
3726 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
3728 if (offset
+ len
> sizeof (siginfo
))
3729 len
= sizeof (siginfo
) - offset
;
3731 if (readbuf
!= NULL
)
3732 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
3735 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
3737 /* Convert back to ptrace layout before flushing it out. */
3738 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
3741 ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3743 return TARGET_XFER_E_IO
;
3747 return TARGET_XFER_OK
;
3750 static enum target_xfer_status
3751 linux_nat_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3752 const char *annex
, gdb_byte
*readbuf
,
3753 const gdb_byte
*writebuf
,
3754 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
3756 struct cleanup
*old_chain
;
3757 enum target_xfer_status xfer
;
3759 if (object
== TARGET_OBJECT_SIGNAL_INFO
)
3760 return linux_xfer_siginfo (ops
, object
, annex
, readbuf
, writebuf
,
3761 offset
, len
, xfered_len
);
3763 /* The target is connected but no live inferior is selected. Pass
3764 this request down to a lower stratum (e.g., the executable
3766 if (object
== TARGET_OBJECT_MEMORY
&& ptid_equal (inferior_ptid
, null_ptid
))
3767 return TARGET_XFER_EOF
;
3769 old_chain
= save_inferior_ptid ();
3771 if (ptid_lwp_p (inferior_ptid
))
3772 inferior_ptid
= pid_to_ptid (ptid_get_lwp (inferior_ptid
));
3774 xfer
= linux_ops
->to_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
3775 offset
, len
, xfered_len
);
3777 do_cleanups (old_chain
);
3782 linux_thread_alive (ptid_t ptid
)
3786 gdb_assert (ptid_lwp_p (ptid
));
3788 /* Send signal 0 instead of anything ptrace, because ptracing a
3789 running thread errors out claiming that the thread doesn't
3791 err
= kill_lwp (ptid_get_lwp (ptid
), 0);
3793 if (debug_linux_nat
)
3794 fprintf_unfiltered (gdb_stdlog
,
3795 "LLTA: KILL(SIG0) %s (%s)\n",
3796 target_pid_to_str (ptid
),
3797 err
? safe_strerror (tmp_errno
) : "OK");
3806 linux_nat_thread_alive (struct target_ops
*ops
, ptid_t ptid
)
3808 return linux_thread_alive (ptid
);
3812 linux_nat_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
3814 static char buf
[64];
3816 if (ptid_lwp_p (ptid
)
3817 && (ptid_get_pid (ptid
) != ptid_get_lwp (ptid
)
3818 || num_lwps (ptid_get_pid (ptid
)) > 1))
3820 snprintf (buf
, sizeof (buf
), "LWP %ld", ptid_get_lwp (ptid
));
3824 return normal_pid_to_str (ptid
);
3828 linux_nat_thread_name (struct target_ops
*self
, struct thread_info
*thr
)
3830 int pid
= ptid_get_pid (thr
->ptid
);
3831 long lwp
= ptid_get_lwp (thr
->ptid
);
3832 #define FORMAT "/proc/%d/task/%ld/comm"
3833 char buf
[sizeof (FORMAT
) + 30];
3835 char *result
= NULL
;
3837 snprintf (buf
, sizeof (buf
), FORMAT
, pid
, lwp
);
3838 comm_file
= gdb_fopen_cloexec (buf
, "r");
3841 /* Not exported by the kernel, so we define it here. */
3843 static char line
[COMM_LEN
+ 1];
3845 if (fgets (line
, sizeof (line
), comm_file
))
3847 char *nl
= strchr (line
, '\n');
3864 /* Accepts an integer PID; Returns a string representing a file that
3865 can be opened to get the symbols for the child process. */
3868 linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
)
3870 static char buf
[PATH_MAX
];
3871 char name
[PATH_MAX
];
3873 xsnprintf (name
, PATH_MAX
, "/proc/%d/exe", pid
);
3874 memset (buf
, 0, PATH_MAX
);
3875 if (readlink (name
, buf
, PATH_MAX
- 1) <= 0)
3881 /* Implement the to_xfer_partial interface for memory reads using the /proc
3882 filesystem. Because we can use a single read() call for /proc, this
3883 can be much more efficient than banging away at PTRACE_PEEKTEXT,
3884 but it doesn't support writes. */
3886 static enum target_xfer_status
3887 linux_proc_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3888 const char *annex
, gdb_byte
*readbuf
,
3889 const gdb_byte
*writebuf
,
3890 ULONGEST offset
, LONGEST len
, ULONGEST
*xfered_len
)
3896 if (object
!= TARGET_OBJECT_MEMORY
|| !readbuf
)
3899 /* Don't bother for one word. */
3900 if (len
< 3 * sizeof (long))
3901 return TARGET_XFER_EOF
;
3903 /* We could keep this file open and cache it - possibly one per
3904 thread. That requires some juggling, but is even faster. */
3905 xsnprintf (filename
, sizeof filename
, "/proc/%d/mem",
3906 ptid_get_pid (inferior_ptid
));
3907 fd
= gdb_open_cloexec (filename
, O_RDONLY
| O_LARGEFILE
, 0);
3909 return TARGET_XFER_EOF
;
3911 /* If pread64 is available, use it. It's faster if the kernel
3912 supports it (only one syscall), and it's 64-bit safe even on
3913 32-bit platforms (for instance, SPARC debugging a SPARC64
3916 if (pread64 (fd
, readbuf
, len
, offset
) != len
)
3918 if (lseek (fd
, offset
, SEEK_SET
) == -1 || read (fd
, readbuf
, len
) != len
)
3927 return TARGET_XFER_EOF
;
3931 return TARGET_XFER_OK
;
3936 /* Enumerate spufs IDs for process PID. */
3938 spu_enumerate_spu_ids (int pid
, gdb_byte
*buf
, ULONGEST offset
, ULONGEST len
)
3940 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
3942 LONGEST written
= 0;
3945 struct dirent
*entry
;
3947 xsnprintf (path
, sizeof path
, "/proc/%d/fd", pid
);
3948 dir
= opendir (path
);
3953 while ((entry
= readdir (dir
)) != NULL
)
3959 fd
= atoi (entry
->d_name
);
3963 xsnprintf (path
, sizeof path
, "/proc/%d/fd/%d", pid
, fd
);
3964 if (stat (path
, &st
) != 0)
3966 if (!S_ISDIR (st
.st_mode
))
3969 if (statfs (path
, &stfs
) != 0)
3971 if (stfs
.f_type
!= SPUFS_MAGIC
)
3974 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
3976 store_unsigned_integer (buf
+ pos
- offset
, 4, byte_order
, fd
);
3986 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
3987 object type, using the /proc file system. */
3989 static enum target_xfer_status
3990 linux_proc_xfer_spu (struct target_ops
*ops
, enum target_object object
,
3991 const char *annex
, gdb_byte
*readbuf
,
3992 const gdb_byte
*writebuf
,
3993 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
3998 int pid
= ptid_get_pid (inferior_ptid
);
4003 return TARGET_XFER_E_IO
;
4006 LONGEST l
= spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4009 return TARGET_XFER_E_IO
;
4011 return TARGET_XFER_EOF
;
4014 *xfered_len
= (ULONGEST
) l
;
4015 return TARGET_XFER_OK
;
4020 xsnprintf (buf
, sizeof buf
, "/proc/%d/fd/%s", pid
, annex
);
4021 fd
= gdb_open_cloexec (buf
, writebuf
? O_WRONLY
: O_RDONLY
, 0);
4023 return TARGET_XFER_E_IO
;
4026 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4029 return TARGET_XFER_EOF
;
4033 ret
= write (fd
, writebuf
, (size_t) len
);
4035 ret
= read (fd
, readbuf
, (size_t) len
);
4040 return TARGET_XFER_E_IO
;
4042 return TARGET_XFER_EOF
;
4045 *xfered_len
= (ULONGEST
) ret
;
4046 return TARGET_XFER_OK
;
4051 /* Parse LINE as a signal set and add its set bits to SIGS. */
4054 add_line_to_sigset (const char *line
, sigset_t
*sigs
)
4056 int len
= strlen (line
) - 1;
4060 if (line
[len
] != '\n')
4061 error (_("Could not parse signal set: %s"), line
);
4069 if (*p
>= '0' && *p
<= '9')
4071 else if (*p
>= 'a' && *p
<= 'f')
4072 digit
= *p
- 'a' + 10;
4074 error (_("Could not parse signal set: %s"), line
);
4079 sigaddset (sigs
, signum
+ 1);
4081 sigaddset (sigs
, signum
+ 2);
4083 sigaddset (sigs
, signum
+ 3);
4085 sigaddset (sigs
, signum
+ 4);
4091 /* Find process PID's pending signals from /proc/pid/status and set
4095 linux_proc_pending_signals (int pid
, sigset_t
*pending
,
4096 sigset_t
*blocked
, sigset_t
*ignored
)
4099 char buffer
[PATH_MAX
], fname
[PATH_MAX
];
4100 struct cleanup
*cleanup
;
4102 sigemptyset (pending
);
4103 sigemptyset (blocked
);
4104 sigemptyset (ignored
);
4105 xsnprintf (fname
, sizeof fname
, "/proc/%d/status", pid
);
4106 procfile
= gdb_fopen_cloexec (fname
, "r");
4107 if (procfile
== NULL
)
4108 error (_("Could not open %s"), fname
);
4109 cleanup
= make_cleanup_fclose (procfile
);
4111 while (fgets (buffer
, PATH_MAX
, procfile
) != NULL
)
4113 /* Normal queued signals are on the SigPnd line in the status
4114 file. However, 2.6 kernels also have a "shared" pending
4115 queue for delivering signals to a thread group, so check for
4118 Unfortunately some Red Hat kernels include the shared pending
4119 queue but not the ShdPnd status field. */
4121 if (strncmp (buffer
, "SigPnd:\t", 8) == 0)
4122 add_line_to_sigset (buffer
+ 8, pending
);
4123 else if (strncmp (buffer
, "ShdPnd:\t", 8) == 0)
4124 add_line_to_sigset (buffer
+ 8, pending
);
4125 else if (strncmp (buffer
, "SigBlk:\t", 8) == 0)
4126 add_line_to_sigset (buffer
+ 8, blocked
);
4127 else if (strncmp (buffer
, "SigIgn:\t", 8) == 0)
4128 add_line_to_sigset (buffer
+ 8, ignored
);
4131 do_cleanups (cleanup
);
4134 static enum target_xfer_status
4135 linux_nat_xfer_osdata (struct target_ops
*ops
, enum target_object object
,
4136 const char *annex
, gdb_byte
*readbuf
,
4137 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4138 ULONGEST
*xfered_len
)
4140 gdb_assert (object
== TARGET_OBJECT_OSDATA
);
4142 *xfered_len
= linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
4143 if (*xfered_len
== 0)
4144 return TARGET_XFER_EOF
;
4146 return TARGET_XFER_OK
;
4149 static enum target_xfer_status
4150 linux_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4151 const char *annex
, gdb_byte
*readbuf
,
4152 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4153 ULONGEST
*xfered_len
)
4155 enum target_xfer_status xfer
;
4157 if (object
== TARGET_OBJECT_AUXV
)
4158 return memory_xfer_auxv (ops
, object
, annex
, readbuf
, writebuf
,
4159 offset
, len
, xfered_len
);
4161 if (object
== TARGET_OBJECT_OSDATA
)
4162 return linux_nat_xfer_osdata (ops
, object
, annex
, readbuf
, writebuf
,
4163 offset
, len
, xfered_len
);
4165 if (object
== TARGET_OBJECT_SPU
)
4166 return linux_proc_xfer_spu (ops
, object
, annex
, readbuf
, writebuf
,
4167 offset
, len
, xfered_len
);
4169 /* GDB calculates all the addresses in possibly larget width of the address.
4170 Address width needs to be masked before its final use - either by
4171 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4173 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4175 if (object
== TARGET_OBJECT_MEMORY
)
4177 int addr_bit
= gdbarch_addr_bit (target_gdbarch ());
4179 if (addr_bit
< (sizeof (ULONGEST
) * HOST_CHAR_BIT
))
4180 offset
&= ((ULONGEST
) 1 << addr_bit
) - 1;
4183 xfer
= linux_proc_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4184 offset
, len
, xfered_len
);
4185 if (xfer
!= TARGET_XFER_EOF
)
4188 return super_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4189 offset
, len
, xfered_len
);
4193 cleanup_target_stop (void *arg
)
4195 ptid_t
*ptid
= (ptid_t
*) arg
;
4197 gdb_assert (arg
!= NULL
);
4200 target_resume (*ptid
, 0, GDB_SIGNAL_0
);
4203 static VEC(static_tracepoint_marker_p
) *
4204 linux_child_static_tracepoint_markers_by_strid (struct target_ops
*self
,
4207 char s
[IPA_CMD_BUF_SIZE
];
4208 struct cleanup
*old_chain
;
4209 int pid
= ptid_get_pid (inferior_ptid
);
4210 VEC(static_tracepoint_marker_p
) *markers
= NULL
;
4211 struct static_tracepoint_marker
*marker
= NULL
;
4213 ptid_t ptid
= ptid_build (pid
, 0, 0);
4218 memcpy (s
, "qTfSTM", sizeof ("qTfSTM"));
4219 s
[sizeof ("qTfSTM")] = 0;
4221 agent_run_command (pid
, s
, strlen (s
) + 1);
4223 old_chain
= make_cleanup (free_current_marker
, &marker
);
4224 make_cleanup (cleanup_target_stop
, &ptid
);
4229 marker
= XCNEW (struct static_tracepoint_marker
);
4233 parse_static_tracepoint_marker_definition (p
, &p
, marker
);
4235 if (strid
== NULL
|| strcmp (strid
, marker
->str_id
) == 0)
4237 VEC_safe_push (static_tracepoint_marker_p
,
4243 release_static_tracepoint_marker (marker
);
4244 memset (marker
, 0, sizeof (*marker
));
4247 while (*p
++ == ','); /* comma-separated list */
4249 memcpy (s
, "qTsSTM", sizeof ("qTsSTM"));
4250 s
[sizeof ("qTsSTM")] = 0;
4251 agent_run_command (pid
, s
, strlen (s
) + 1);
4255 do_cleanups (old_chain
);
4260 /* Create a prototype generic GNU/Linux target. The client can override
4261 it with local methods. */
4264 linux_target_install_ops (struct target_ops
*t
)
4266 t
->to_insert_fork_catchpoint
= linux_child_insert_fork_catchpoint
;
4267 t
->to_remove_fork_catchpoint
= linux_child_remove_fork_catchpoint
;
4268 t
->to_insert_vfork_catchpoint
= linux_child_insert_vfork_catchpoint
;
4269 t
->to_remove_vfork_catchpoint
= linux_child_remove_vfork_catchpoint
;
4270 t
->to_insert_exec_catchpoint
= linux_child_insert_exec_catchpoint
;
4271 t
->to_remove_exec_catchpoint
= linux_child_remove_exec_catchpoint
;
4272 t
->to_set_syscall_catchpoint
= linux_child_set_syscall_catchpoint
;
4273 t
->to_pid_to_exec_file
= linux_child_pid_to_exec_file
;
4274 t
->to_post_startup_inferior
= linux_child_post_startup_inferior
;
4275 t
->to_post_attach
= linux_child_post_attach
;
4276 t
->to_follow_fork
= linux_child_follow_fork
;
4278 super_xfer_partial
= t
->to_xfer_partial
;
4279 t
->to_xfer_partial
= linux_xfer_partial
;
4281 t
->to_static_tracepoint_markers_by_strid
4282 = linux_child_static_tracepoint_markers_by_strid
;
4288 struct target_ops
*t
;
4290 t
= inf_ptrace_target ();
4291 linux_target_install_ops (t
);
4297 linux_trad_target (CORE_ADDR (*register_u_offset
)(struct gdbarch
*, int, int))
4299 struct target_ops
*t
;
4301 t
= inf_ptrace_trad_target (register_u_offset
);
4302 linux_target_install_ops (t
);
4307 /* target_is_async_p implementation. */
4310 linux_nat_is_async_p (struct target_ops
*ops
)
4312 /* NOTE: palves 2008-03-21: We're only async when the user requests
4313 it explicitly with the "set target-async" command.
4314 Someday, linux will always be async. */
4315 return target_async_permitted
;
4318 /* target_can_async_p implementation. */
4321 linux_nat_can_async_p (struct target_ops
*ops
)
4323 /* NOTE: palves 2008-03-21: We're only async when the user requests
4324 it explicitly with the "set target-async" command.
4325 Someday, linux will always be async. */
4326 return target_async_permitted
;
4330 linux_nat_supports_non_stop (struct target_ops
*self
)
4335 /* True if we want to support multi-process. To be removed when GDB
4336 supports multi-exec. */
4338 int linux_multi_process
= 1;
4341 linux_nat_supports_multi_process (struct target_ops
*self
)
4343 return linux_multi_process
;
4347 linux_nat_supports_disable_randomization (struct target_ops
*self
)
4349 #ifdef HAVE_PERSONALITY
4356 static int async_terminal_is_ours
= 1;
4358 /* target_terminal_inferior implementation.
4360 This is a wrapper around child_terminal_inferior to add async support. */
4363 linux_nat_terminal_inferior (struct target_ops
*self
)
4365 if (!target_is_async_p ())
4367 /* Async mode is disabled. */
4368 child_terminal_inferior (self
);
4372 child_terminal_inferior (self
);
4374 /* Calls to target_terminal_*() are meant to be idempotent. */
4375 if (!async_terminal_is_ours
)
4378 delete_file_handler (input_fd
);
4379 async_terminal_is_ours
= 0;
4383 /* target_terminal_ours implementation.
4385 This is a wrapper around child_terminal_ours to add async support (and
4386 implement the target_terminal_ours vs target_terminal_ours_for_output
4387 distinction). child_terminal_ours is currently no different than
4388 child_terminal_ours_for_output.
4389 We leave target_terminal_ours_for_output alone, leaving it to
4390 child_terminal_ours_for_output. */
4393 linux_nat_terminal_ours (struct target_ops
*self
)
4395 if (!target_is_async_p ())
4397 /* Async mode is disabled. */
4398 child_terminal_ours (self
);
4402 /* GDB should never give the terminal to the inferior if the
4403 inferior is running in the background (run&, continue&, etc.),
4404 but claiming it sure should. */
4405 child_terminal_ours (self
);
4407 if (async_terminal_is_ours
)
4410 clear_sigint_trap ();
4411 add_file_handler (input_fd
, stdin_event_handler
, 0);
4412 async_terminal_is_ours
= 1;
4415 static void (*async_client_callback
) (enum inferior_event_type event_type
,
4417 static void *async_client_context
;
4419 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4420 so we notice when any child changes state, and notify the
4421 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4422 above to wait for the arrival of a SIGCHLD. */
4425 sigchld_handler (int signo
)
4427 int old_errno
= errno
;
4429 if (debug_linux_nat
)
4430 ui_file_write_async_safe (gdb_stdlog
,
4431 "sigchld\n", sizeof ("sigchld\n") - 1);
4433 if (signo
== SIGCHLD
4434 && linux_nat_event_pipe
[0] != -1)
4435 async_file_mark (); /* Let the event loop know that there are
4436 events to handle. */
4441 /* Callback registered with the target events file descriptor. */
4444 handle_target_event (int error
, gdb_client_data client_data
)
4446 (*async_client_callback
) (INF_REG_EVENT
, async_client_context
);
4449 /* Create/destroy the target events pipe. Returns previous state. */
4452 linux_async_pipe (int enable
)
4454 int previous
= (linux_nat_event_pipe
[0] != -1);
4456 if (previous
!= enable
)
4460 /* Block child signals while we create/destroy the pipe, as
4461 their handler writes to it. */
4462 block_child_signals (&prev_mask
);
4466 if (gdb_pipe_cloexec (linux_nat_event_pipe
) == -1)
4467 internal_error (__FILE__
, __LINE__
,
4468 "creating event pipe failed.");
4470 fcntl (linux_nat_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4471 fcntl (linux_nat_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4475 close (linux_nat_event_pipe
[0]);
4476 close (linux_nat_event_pipe
[1]);
4477 linux_nat_event_pipe
[0] = -1;
4478 linux_nat_event_pipe
[1] = -1;
4481 restore_child_signals_mask (&prev_mask
);
4487 /* target_async implementation. */
4490 linux_nat_async (struct target_ops
*ops
,
4491 void (*callback
) (enum inferior_event_type event_type
,
4495 if (callback
!= NULL
)
4497 async_client_callback
= callback
;
4498 async_client_context
= context
;
4499 if (!linux_async_pipe (1))
4501 add_file_handler (linux_nat_event_pipe
[0],
4502 handle_target_event
, NULL
);
4503 /* There may be pending events to handle. Tell the event loop
4510 async_client_callback
= callback
;
4511 async_client_context
= context
;
4512 delete_file_handler (linux_nat_event_pipe
[0]);
4513 linux_async_pipe (0);
4518 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4522 linux_nat_stop_lwp (struct lwp_info
*lwp
, void *data
)
4526 if (debug_linux_nat
)
4527 fprintf_unfiltered (gdb_stdlog
,
4528 "LNSL: running -> suspending %s\n",
4529 target_pid_to_str (lwp
->ptid
));
4532 if (lwp
->last_resume_kind
== resume_stop
)
4534 if (debug_linux_nat
)
4535 fprintf_unfiltered (gdb_stdlog
,
4536 "linux-nat: already stopping LWP %ld at "
4538 ptid_get_lwp (lwp
->ptid
));
4542 stop_callback (lwp
, NULL
);
4543 lwp
->last_resume_kind
= resume_stop
;
4547 /* Already known to be stopped; do nothing. */
4549 if (debug_linux_nat
)
4551 if (find_thread_ptid (lwp
->ptid
)->stop_requested
)
4552 fprintf_unfiltered (gdb_stdlog
,
4553 "LNSL: already stopped/stop_requested %s\n",
4554 target_pid_to_str (lwp
->ptid
));
4556 fprintf_unfiltered (gdb_stdlog
,
4557 "LNSL: already stopped/no "
4558 "stop_requested yet %s\n",
4559 target_pid_to_str (lwp
->ptid
));
4566 linux_nat_stop (struct target_ops
*self
, ptid_t ptid
)
4569 iterate_over_lwps (ptid
, linux_nat_stop_lwp
, NULL
);
4571 linux_ops
->to_stop (linux_ops
, ptid
);
4575 linux_nat_close (struct target_ops
*self
)
4577 /* Unregister from the event loop. */
4578 if (linux_nat_is_async_p (self
))
4579 linux_nat_async (self
, NULL
, NULL
);
4581 if (linux_ops
->to_close
)
4582 linux_ops
->to_close (linux_ops
);
4587 /* When requests are passed down from the linux-nat layer to the
4588 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4589 used. The address space pointer is stored in the inferior object,
4590 but the common code that is passed such ptid can't tell whether
4591 lwpid is a "main" process id or not (it assumes so). We reverse
4592 look up the "main" process id from the lwp here. */
4594 static struct address_space
*
4595 linux_nat_thread_address_space (struct target_ops
*t
, ptid_t ptid
)
4597 struct lwp_info
*lwp
;
4598 struct inferior
*inf
;
4601 if (ptid_get_lwp (ptid
) == 0)
4603 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4605 lwp
= find_lwp_pid (ptid
);
4606 pid
= ptid_get_pid (lwp
->ptid
);
4610 /* A (pid,lwpid,0) ptid. */
4611 pid
= ptid_get_pid (ptid
);
4614 inf
= find_inferior_pid (pid
);
4615 gdb_assert (inf
!= NULL
);
4619 /* Return the cached value of the processor core for thread PTID. */
4622 linux_nat_core_of_thread (struct target_ops
*ops
, ptid_t ptid
)
4624 struct lwp_info
*info
= find_lwp_pid (ptid
);
4632 linux_nat_add_target (struct target_ops
*t
)
4634 /* Save the provided single-threaded target. We save this in a separate
4635 variable because another target we've inherited from (e.g. inf-ptrace)
4636 may have saved a pointer to T; we want to use it for the final
4637 process stratum target. */
4638 linux_ops_saved
= *t
;
4639 linux_ops
= &linux_ops_saved
;
4641 /* Override some methods for multithreading. */
4642 t
->to_create_inferior
= linux_nat_create_inferior
;
4643 t
->to_attach
= linux_nat_attach
;
4644 t
->to_detach
= linux_nat_detach
;
4645 t
->to_resume
= linux_nat_resume
;
4646 t
->to_wait
= linux_nat_wait
;
4647 t
->to_pass_signals
= linux_nat_pass_signals
;
4648 t
->to_xfer_partial
= linux_nat_xfer_partial
;
4649 t
->to_kill
= linux_nat_kill
;
4650 t
->to_mourn_inferior
= linux_nat_mourn_inferior
;
4651 t
->to_thread_alive
= linux_nat_thread_alive
;
4652 t
->to_pid_to_str
= linux_nat_pid_to_str
;
4653 t
->to_thread_name
= linux_nat_thread_name
;
4654 t
->to_has_thread_control
= tc_schedlock
;
4655 t
->to_thread_address_space
= linux_nat_thread_address_space
;
4656 t
->to_stopped_by_watchpoint
= linux_nat_stopped_by_watchpoint
;
4657 t
->to_stopped_data_address
= linux_nat_stopped_data_address
;
4659 t
->to_can_async_p
= linux_nat_can_async_p
;
4660 t
->to_is_async_p
= linux_nat_is_async_p
;
4661 t
->to_supports_non_stop
= linux_nat_supports_non_stop
;
4662 t
->to_async
= linux_nat_async
;
4663 t
->to_terminal_inferior
= linux_nat_terminal_inferior
;
4664 t
->to_terminal_ours
= linux_nat_terminal_ours
;
4666 super_close
= t
->to_close
;
4667 t
->to_close
= linux_nat_close
;
4669 /* Methods for non-stop support. */
4670 t
->to_stop
= linux_nat_stop
;
4672 t
->to_supports_multi_process
= linux_nat_supports_multi_process
;
4674 t
->to_supports_disable_randomization
4675 = linux_nat_supports_disable_randomization
;
4677 t
->to_core_of_thread
= linux_nat_core_of_thread
;
4679 /* We don't change the stratum; this target will sit at
4680 process_stratum and thread_db will set at thread_stratum. This
4681 is a little strange, since this is a multi-threaded-capable
4682 target, but we want to be on the stack below thread_db, and we
4683 also want to be used for single-threaded processes. */
4688 /* Register a method to call whenever a new thread is attached. */
4690 linux_nat_set_new_thread (struct target_ops
*t
,
4691 void (*new_thread
) (struct lwp_info
*))
4693 /* Save the pointer. We only support a single registered instance
4694 of the GNU/Linux native target, so we do not need to map this to
4696 linux_nat_new_thread
= new_thread
;
4699 /* See declaration in linux-nat.h. */
4702 linux_nat_set_new_fork (struct target_ops
*t
,
4703 linux_nat_new_fork_ftype
*new_fork
)
4705 /* Save the pointer. */
4706 linux_nat_new_fork
= new_fork
;
4709 /* See declaration in linux-nat.h. */
4712 linux_nat_set_forget_process (struct target_ops
*t
,
4713 linux_nat_forget_process_ftype
*fn
)
4715 /* Save the pointer. */
4716 linux_nat_forget_process_hook
= fn
;
4719 /* See declaration in linux-nat.h. */
4722 linux_nat_forget_process (pid_t pid
)
4724 if (linux_nat_forget_process_hook
!= NULL
)
4725 linux_nat_forget_process_hook (pid
);
4728 /* Register a method that converts a siginfo object between the layout
4729 that ptrace returns, and the layout in the architecture of the
4732 linux_nat_set_siginfo_fixup (struct target_ops
*t
,
4733 int (*siginfo_fixup
) (siginfo_t
*,
4737 /* Save the pointer. */
4738 linux_nat_siginfo_fixup
= siginfo_fixup
;
4741 /* Register a method to call prior to resuming a thread. */
4744 linux_nat_set_prepare_to_resume (struct target_ops
*t
,
4745 void (*prepare_to_resume
) (struct lwp_info
*))
4747 /* Save the pointer. */
4748 linux_nat_prepare_to_resume
= prepare_to_resume
;
4751 /* See linux-nat.h. */
4754 linux_nat_get_siginfo (ptid_t ptid
, siginfo_t
*siginfo
)
4758 pid
= ptid_get_lwp (ptid
);
4760 pid
= ptid_get_pid (ptid
);
4763 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, siginfo
);
4766 memset (siginfo
, 0, sizeof (*siginfo
));
4772 /* Provide a prototype to silence -Wmissing-prototypes. */
4773 extern initialize_file_ftype _initialize_linux_nat
;
4776 _initialize_linux_nat (void)
4778 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance
,
4779 &debug_linux_nat
, _("\
4780 Set debugging of GNU/Linux lwp module."), _("\
4781 Show debugging of GNU/Linux lwp module."), _("\
4782 Enables printf debugging output."),
4784 show_debug_linux_nat
,
4785 &setdebuglist
, &showdebuglist
);
4787 /* Save this mask as the default. */
4788 sigprocmask (SIG_SETMASK
, NULL
, &normal_mask
);
4790 /* Install a SIGCHLD handler. */
4791 sigchld_action
.sa_handler
= sigchld_handler
;
4792 sigemptyset (&sigchld_action
.sa_mask
);
4793 sigchld_action
.sa_flags
= SA_RESTART
;
4795 /* Make it the default. */
4796 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
4798 /* Make sure we don't block SIGCHLD during a sigsuspend. */
4799 sigprocmask (SIG_SETMASK
, NULL
, &suspend_mask
);
4800 sigdelset (&suspend_mask
, SIGCHLD
);
4802 sigemptyset (&blocked_mask
);
4804 /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to
4805 support read-only process state. */
4806 linux_ptrace_set_additional_flags (PTRACE_O_TRACESYSGOOD
4807 | PTRACE_O_TRACEVFORKDONE
4808 | PTRACE_O_TRACEVFORK
4809 | PTRACE_O_TRACEFORK
4810 | PTRACE_O_TRACEEXEC
);
4814 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
4815 the GNU/Linux Threads library and therefore doesn't really belong
4818 /* Read variable NAME in the target and return its value if found.
4819 Otherwise return zero. It is assumed that the type of the variable
4823 get_signo (const char *name
)
4825 struct bound_minimal_symbol ms
;
4828 ms
= lookup_minimal_symbol (name
, NULL
, NULL
);
4829 if (ms
.minsym
== NULL
)
4832 if (target_read_memory (BMSYMBOL_VALUE_ADDRESS (ms
), (gdb_byte
*) &signo
,
4833 sizeof (signo
)) != 0)
4839 /* Return the set of signals used by the threads library in *SET. */
4842 lin_thread_get_thread_signals (sigset_t
*set
)
4844 struct sigaction action
;
4845 int restart
, cancel
;
4847 sigemptyset (&blocked_mask
);
4850 restart
= get_signo ("__pthread_sig_restart");
4851 cancel
= get_signo ("__pthread_sig_cancel");
4853 /* LinuxThreads normally uses the first two RT signals, but in some legacy
4854 cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
4855 not provide any way for the debugger to query the signal numbers -
4856 fortunately they don't change! */
4859 restart
= __SIGRTMIN
;
4862 cancel
= __SIGRTMIN
+ 1;
4864 sigaddset (set
, restart
);
4865 sigaddset (set
, cancel
);
4867 /* The GNU/Linux Threads library makes terminating threads send a
4868 special "cancel" signal instead of SIGCHLD. Make sure we catch
4869 those (to prevent them from terminating GDB itself, which is
4870 likely to be their default action) and treat them the same way as
4873 action
.sa_handler
= sigchld_handler
;
4874 sigemptyset (&action
.sa_mask
);
4875 action
.sa_flags
= SA_RESTART
;
4876 sigaction (cancel
, &action
, NULL
);
4878 /* We block the "cancel" signal throughout this code ... */
4879 sigaddset (&blocked_mask
, cancel
);
4880 sigprocmask (SIG_BLOCK
, &blocked_mask
, NULL
);
4882 /* ... except during a sigsuspend. */
4883 sigdelset (&suspend_mask
, cancel
);