1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001-2015 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "nat/linux-nat.h"
25 #include "nat/linux-waitpid.h"
27 #ifdef HAVE_TKILL_SYSCALL
29 #include <sys/syscall.h>
31 #include <sys/ptrace.h>
32 #include "linux-nat.h"
33 #include "nat/linux-ptrace.h"
34 #include "nat/linux-procfs.h"
35 #include "nat/linux-personality.h"
36 #include "linux-fork.h"
37 #include "gdbthread.h"
41 #include "inf-child.h"
42 #include "inf-ptrace.h"
44 #include <sys/procfs.h> /* for elf_gregset etc. */
45 #include "elf-bfd.h" /* for elfcore_write_* */
46 #include "gregset.h" /* for gregset */
47 #include "gdbcore.h" /* for get_exec_file */
48 #include <ctype.h> /* for isdigit */
49 #include <sys/stat.h> /* for struct stat */
50 #include <fcntl.h> /* for O_RDONLY */
52 #include "event-loop.h"
53 #include "event-top.h"
55 #include <sys/types.h>
57 #include "xml-support.h"
60 #include "nat/linux-osdata.h"
61 #include "linux-tdep.h"
64 #include "tracepoint.h"
66 #include "target-descriptions.h"
67 #include "filestuff.h"
69 #include "nat/linux-namespaces.h"
73 #define SPUFS_MAGIC 0x23c9b64e
76 /* This comment documents high-level logic of this file.
78 Waiting for events in sync mode
79 ===============================
81 When waiting for an event in a specific thread, we just use waitpid, passing
82 the specific pid, and not passing WNOHANG.
84 When waiting for an event in all threads, waitpid is not quite good. Prior to
85 version 2.4, Linux can either wait for event in main thread, or in secondary
86 threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might
87 miss an event. The solution is to use non-blocking waitpid, together with
88 sigsuspend. First, we use non-blocking waitpid to get an event in the main
89 process, if any. Second, we use non-blocking waitpid with the __WCLONED
90 flag to check for events in cloned processes. If nothing is found, we use
91 sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something
92 happened to a child process -- and SIGCHLD will be delivered both for events
93 in main debugged process and in cloned processes. As soon as we know there's
94 an event, we get back to calling nonblocking waitpid with and without
97 Note that SIGCHLD should be blocked between waitpid and sigsuspend calls,
98 so that we don't miss a signal. If SIGCHLD arrives in between, when it's
99 blocked, the signal becomes pending and sigsuspend immediately
100 notices it and returns.
102 Waiting for events in async mode
103 ================================
105 In async mode, GDB should always be ready to handle both user input
106 and target events, so neither blocking waitpid nor sigsuspend are
107 viable options. Instead, we should asynchronously notify the GDB main
108 event loop whenever there's an unprocessed event from the target. We
109 detect asynchronous target events by handling SIGCHLD signals. To
110 notify the event loop about target events, the self-pipe trick is used
111 --- a pipe is registered as waitable event source in the event loop,
112 the event loop select/poll's on the read end of this pipe (as well on
113 other event sources, e.g., stdin), and the SIGCHLD handler writes a
114 byte to this pipe. This is more portable than relying on
115 pselect/ppoll, since on kernels that lack those syscalls, libc
116 emulates them with select/poll+sigprocmask, and that is racy
117 (a.k.a. plain broken).
119 Obviously, if we fail to notify the event loop if there's a target
120 event, it's bad. OTOH, if we notify the event loop when there's no
121 event from the target, linux_nat_wait will detect that there's no real
122 event to report, and return event of type TARGET_WAITKIND_IGNORE.
123 This is mostly harmless, but it will waste time and is better avoided.
125 The main design point is that every time GDB is outside linux-nat.c,
126 we have a SIGCHLD handler installed that is called when something
127 happens to the target and notifies the GDB event loop. Whenever GDB
128 core decides to handle the event, and calls into linux-nat.c, we
129 process things as in sync mode, except that the we never block in
132 While processing an event, we may end up momentarily blocked in
133 waitpid calls. Those waitpid calls, while blocking, are guarantied to
134 return quickly. E.g., in all-stop mode, before reporting to the core
135 that an LWP hit a breakpoint, all LWPs are stopped by sending them
136 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
137 Note that this is different from blocking indefinitely waiting for the
138 next event --- here, we're already handling an event.
143 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
144 signal is not entirely significant; we just need for a signal to be delivered,
145 so that we can intercept it. SIGSTOP's advantage is that it can not be
146 blocked. A disadvantage is that it is not a real-time signal, so it can only
147 be queued once; we do not keep track of other sources of SIGSTOP.
149 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
150 use them, because they have special behavior when the signal is generated -
151 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
152 kills the entire thread group.
154 A delivered SIGSTOP would stop the entire thread group, not just the thread we
155 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
156 cancel it (by PTRACE_CONT without passing SIGSTOP).
158 We could use a real-time signal instead. This would solve those problems; we
159 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
160 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
161 generates it, and there are races with trying to find a signal that is not
165 #define O_LARGEFILE 0
168 /* Does the current host support PTRACE_GETREGSET? */
169 int have_ptrace_getregset = -1;
171 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
172 the use of the multi-threaded target. */
173 static struct target_ops *linux_ops;
174 static struct target_ops linux_ops_saved;
176 /* The method to call, if any, when a new thread is attached. */
177 static void (*linux_nat_new_thread) (struct lwp_info *);
179 /* The method to call, if any, when a new fork is attached. */
180 static linux_nat_new_fork_ftype *linux_nat_new_fork;
182 /* The method to call, if any, when a process is no longer
184 static linux_nat_forget_process_ftype *linux_nat_forget_process_hook;
186 /* Hook to call prior to resuming a thread. */
187 static void (*linux_nat_prepare_to_resume) (struct lwp_info *);
189 /* The method to call, if any, when the siginfo object needs to be
190 converted between the layout returned by ptrace, and the layout in
191 the architecture of the inferior. */
192 static int (*linux_nat_siginfo_fixup) (siginfo_t *,
196 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
197 Called by our to_xfer_partial. */
198 static target_xfer_partial_ftype *super_xfer_partial;
200 /* The saved to_close method, inherited from inf-ptrace.c.
201 Called by our to_close. */
202 static void (*super_close) (struct target_ops *);
204 static unsigned int debug_linux_nat;
206 show_debug_linux_nat (struct ui_file *file, int from_tty,
207 struct cmd_list_element *c, const char *value)
209 fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"),
213 struct simple_pid_list
217 struct simple_pid_list *next;
219 struct simple_pid_list *stopped_pids;
221 /* Async mode support. */
223 /* The read/write ends of the pipe registered as waitable file in the
225 static int linux_nat_event_pipe[2] = { -1, -1 };
227 /* True if we're currently in async mode. */
228 #define linux_is_async_p() (linux_nat_event_pipe[0] != -1)
230 /* Flush the event pipe. */
233 async_file_flush (void)
240 ret = read (linux_nat_event_pipe[0], &buf, 1);
242 while (ret >= 0 || (ret == -1 && errno == EINTR));
245 /* Put something (anything, doesn't matter what, or how much) in event
246 pipe, so that the select/poll in the event-loop realizes we have
247 something to process. */
250 async_file_mark (void)
254 /* It doesn't really matter what the pipe contains, as long we end
255 up with something in it. Might as well flush the previous
261 ret = write (linux_nat_event_pipe[1], "+", 1);
263 while (ret == -1 && errno == EINTR);
265 /* Ignore EAGAIN. If the pipe is full, the event loop will already
266 be awakened anyway. */
269 static int kill_lwp (int lwpid, int signo);
271 static int stop_callback (struct lwp_info *lp, void *data);
272 static int resume_stopped_resumed_lwps (struct lwp_info *lp, void *data);
274 static void block_child_signals (sigset_t *prev_mask);
275 static void restore_child_signals_mask (sigset_t *prev_mask);
278 static struct lwp_info *add_lwp (ptid_t ptid);
279 static void purge_lwp_list (int pid);
280 static void delete_lwp (ptid_t ptid);
281 static struct lwp_info *find_lwp_pid (ptid_t ptid);
283 static int lwp_status_pending_p (struct lwp_info *lp);
285 static int check_stopped_by_breakpoint (struct lwp_info *lp);
286 static int sigtrap_is_event (int status);
287 static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event;
292 /* See nat/linux-nat.h. */
295 ptid_of_lwp (struct lwp_info *lwp)
300 /* See nat/linux-nat.h. */
303 lwp_set_arch_private_info (struct lwp_info *lwp,
304 struct arch_lwp_info *info)
306 lwp->arch_private = info;
309 /* See nat/linux-nat.h. */
311 struct arch_lwp_info *
312 lwp_arch_private_info (struct lwp_info *lwp)
314 return lwp->arch_private;
317 /* See nat/linux-nat.h. */
320 lwp_is_stopped (struct lwp_info *lwp)
325 /* See nat/linux-nat.h. */
327 enum target_stop_reason
328 lwp_stop_reason (struct lwp_info *lwp)
330 return lwp->stop_reason;
334 /* Trivial list manipulation functions to keep track of a list of
335 new stopped processes. */
337 add_to_pid_list (struct simple_pid_list **listp, int pid, int status)
339 struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list));
342 new_pid->status = status;
343 new_pid->next = *listp;
348 in_pid_list_p (struct simple_pid_list *list, int pid)
350 struct simple_pid_list *p;
352 for (p = list; p != NULL; p = p->next)
359 pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp)
361 struct simple_pid_list **p;
363 for (p = listp; *p != NULL; p = &(*p)->next)
364 if ((*p)->pid == pid)
366 struct simple_pid_list *next = (*p)->next;
368 *statusp = (*p)->status;
376 /* Return the ptrace options that we want to try to enable. */
379 linux_nat_ptrace_options (int attached)
384 options |= PTRACE_O_EXITKILL;
386 options |= (PTRACE_O_TRACESYSGOOD
387 | PTRACE_O_TRACEVFORKDONE
388 | PTRACE_O_TRACEVFORK
390 | PTRACE_O_TRACEEXEC);
395 /* Initialize ptrace warnings and check for supported ptrace
398 ATTACHED should be nonzero iff we attached to the inferior. */
401 linux_init_ptrace (pid_t pid, int attached)
403 int options = linux_nat_ptrace_options (attached);
405 linux_enable_event_reporting (pid, options);
406 linux_ptrace_init_warnings ();
410 linux_child_post_attach (struct target_ops *self, int pid)
412 linux_init_ptrace (pid, 1);
416 linux_child_post_startup_inferior (struct target_ops *self, ptid_t ptid)
418 linux_init_ptrace (ptid_get_pid (ptid), 0);
421 /* Return the number of known LWPs in the tgid given by PID. */
429 for (lp = lwp_list; lp; lp = lp->next)
430 if (ptid_get_pid (lp->ptid) == pid)
436 /* Call delete_lwp with prototype compatible for make_cleanup. */
439 delete_lwp_cleanup (void *lp_voidp)
441 struct lwp_info *lp = lp_voidp;
443 delete_lwp (lp->ptid);
446 /* Target hook for follow_fork. On entry inferior_ptid must be the
447 ptid of the followed inferior. At return, inferior_ptid will be
451 linux_child_follow_fork (struct target_ops *ops, int follow_child,
456 struct lwp_info *child_lp = NULL;
457 int status = W_STOPCODE (0);
458 struct cleanup *old_chain;
460 ptid_t parent_ptid, child_ptid;
461 int parent_pid, child_pid;
463 has_vforked = (inferior_thread ()->pending_follow.kind
464 == TARGET_WAITKIND_VFORKED);
465 parent_ptid = inferior_ptid;
466 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
467 parent_pid = ptid_get_lwp (parent_ptid);
468 child_pid = ptid_get_lwp (child_ptid);
470 /* We're already attached to the parent, by default. */
471 old_chain = save_inferior_ptid ();
472 inferior_ptid = child_ptid;
473 child_lp = add_lwp (inferior_ptid);
474 child_lp->stopped = 1;
475 child_lp->last_resume_kind = resume_stop;
477 /* Detach new forked process? */
480 make_cleanup (delete_lwp_cleanup, child_lp);
482 if (linux_nat_prepare_to_resume != NULL)
483 linux_nat_prepare_to_resume (child_lp);
485 /* When debugging an inferior in an architecture that supports
486 hardware single stepping on a kernel without commit
487 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child
488 process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits
489 set if the parent process had them set.
490 To work around this, single step the child process
491 once before detaching to clear the flags. */
493 if (!gdbarch_software_single_step_p (target_thread_architecture
496 linux_disable_event_reporting (child_pid);
497 if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0)
498 perror_with_name (_("Couldn't do single step"));
499 if (my_waitpid (child_pid, &status, 0) < 0)
500 perror_with_name (_("Couldn't wait vfork process"));
503 if (WIFSTOPPED (status))
507 signo = WSTOPSIG (status);
509 && !signal_pass_state (gdb_signal_from_host (signo)))
511 ptrace (PTRACE_DETACH, child_pid, 0, signo);
514 /* Resets value of inferior_ptid to parent ptid. */
515 do_cleanups (old_chain);
519 /* Let the thread_db layer learn about this new process. */
520 check_for_thread_db ();
523 do_cleanups (old_chain);
527 struct lwp_info *parent_lp;
529 parent_lp = find_lwp_pid (parent_ptid);
530 gdb_assert (linux_supports_tracefork () >= 0);
532 if (linux_supports_tracevforkdone ())
535 fprintf_unfiltered (gdb_stdlog,
536 "LCFF: waiting for VFORK_DONE on %d\n",
538 parent_lp->stopped = 1;
540 /* We'll handle the VFORK_DONE event like any other
541 event, in target_wait. */
545 /* We can't insert breakpoints until the child has
546 finished with the shared memory region. We need to
547 wait until that happens. Ideal would be to just
549 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
550 - waitpid (parent_pid, &status, __WALL);
551 However, most architectures can't handle a syscall
552 being traced on the way out if it wasn't traced on
555 We might also think to loop, continuing the child
556 until it exits or gets a SIGTRAP. One problem is
557 that the child might call ptrace with PTRACE_TRACEME.
559 There's no simple and reliable way to figure out when
560 the vforked child will be done with its copy of the
561 shared memory. We could step it out of the syscall,
562 two instructions, let it go, and then single-step the
563 parent once. When we have hardware single-step, this
564 would work; with software single-step it could still
565 be made to work but we'd have to be able to insert
566 single-step breakpoints in the child, and we'd have
567 to insert -just- the single-step breakpoint in the
568 parent. Very awkward.
570 In the end, the best we can do is to make sure it
571 runs for a little while. Hopefully it will be out of
572 range of any breakpoints we reinsert. Usually this
573 is only the single-step breakpoint at vfork's return
577 fprintf_unfiltered (gdb_stdlog,
578 "LCFF: no VFORK_DONE "
579 "support, sleeping a bit\n");
583 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
584 and leave it pending. The next linux_nat_resume call
585 will notice a pending event, and bypasses actually
586 resuming the inferior. */
587 parent_lp->status = 0;
588 parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE;
589 parent_lp->stopped = 1;
591 /* If we're in async mode, need to tell the event loop
592 there's something here to process. */
593 if (target_is_async_p ())
600 struct lwp_info *child_lp;
602 child_lp = add_lwp (inferior_ptid);
603 child_lp->stopped = 1;
604 child_lp->last_resume_kind = resume_stop;
606 /* Let the thread_db layer learn about this new process. */
607 check_for_thread_db ();
615 linux_child_insert_fork_catchpoint (struct target_ops *self, int pid)
617 return !linux_supports_tracefork ();
621 linux_child_remove_fork_catchpoint (struct target_ops *self, int pid)
627 linux_child_insert_vfork_catchpoint (struct target_ops *self, int pid)
629 return !linux_supports_tracefork ();
633 linux_child_remove_vfork_catchpoint (struct target_ops *self, int pid)
639 linux_child_insert_exec_catchpoint (struct target_ops *self, int pid)
641 return !linux_supports_tracefork ();
645 linux_child_remove_exec_catchpoint (struct target_ops *self, int pid)
651 linux_child_set_syscall_catchpoint (struct target_ops *self,
652 int pid, int needed, int any_count,
653 int table_size, int *table)
655 if (!linux_supports_tracesysgood ())
658 /* On GNU/Linux, we ignore the arguments. It means that we only
659 enable the syscall catchpoints, but do not disable them.
661 Also, we do not use the `table' information because we do not
662 filter system calls here. We let GDB do the logic for us. */
666 /* On GNU/Linux there are no real LWP's. The closest thing to LWP's
667 are processes sharing the same VM space. A multi-threaded process
668 is basically a group of such processes. However, such a grouping
669 is almost entirely a user-space issue; the kernel doesn't enforce
670 such a grouping at all (this might change in the future). In
671 general, we'll rely on the threads library (i.e. the GNU/Linux
672 Threads library) to provide such a grouping.
674 It is perfectly well possible to write a multi-threaded application
675 without the assistance of a threads library, by using the clone
676 system call directly. This module should be able to give some
677 rudimentary support for debugging such applications if developers
678 specify the CLONE_PTRACE flag in the clone system call, and are
679 using the Linux kernel 2.4 or above.
681 Note that there are some peculiarities in GNU/Linux that affect
684 - In general one should specify the __WCLONE flag to waitpid in
685 order to make it report events for any of the cloned processes
686 (and leave it out for the initial process). However, if a cloned
687 process has exited the exit status is only reported if the
688 __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
689 we cannot use it since GDB must work on older systems too.
691 - When a traced, cloned process exits and is waited for by the
692 debugger, the kernel reassigns it to the original parent and
693 keeps it around as a "zombie". Somehow, the GNU/Linux Threads
694 library doesn't notice this, which leads to the "zombie problem":
695 When debugged a multi-threaded process that spawns a lot of
696 threads will run out of processes, even if the threads exit,
697 because the "zombies" stay around. */
699 /* List of known LWPs. */
700 struct lwp_info *lwp_list;
703 /* Original signal mask. */
704 static sigset_t normal_mask;
706 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
707 _initialize_linux_nat. */
708 static sigset_t suspend_mask;
710 /* Signals to block to make that sigsuspend work. */
711 static sigset_t blocked_mask;
713 /* SIGCHLD action. */
714 struct sigaction sigchld_action;
716 /* Block child signals (SIGCHLD and linux threads signals), and store
717 the previous mask in PREV_MASK. */
720 block_child_signals (sigset_t *prev_mask)
722 /* Make sure SIGCHLD is blocked. */
723 if (!sigismember (&blocked_mask, SIGCHLD))
724 sigaddset (&blocked_mask, SIGCHLD);
726 sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask);
729 /* Restore child signals mask, previously returned by
730 block_child_signals. */
733 restore_child_signals_mask (sigset_t *prev_mask)
735 sigprocmask (SIG_SETMASK, prev_mask, NULL);
738 /* Mask of signals to pass directly to the inferior. */
739 static sigset_t pass_mask;
741 /* Update signals to pass to the inferior. */
743 linux_nat_pass_signals (struct target_ops *self,
744 int numsigs, unsigned char *pass_signals)
748 sigemptyset (&pass_mask);
750 for (signo = 1; signo < NSIG; signo++)
752 int target_signo = gdb_signal_from_host (signo);
753 if (target_signo < numsigs && pass_signals[target_signo])
754 sigaddset (&pass_mask, signo);
760 /* Prototypes for local functions. */
761 static int stop_wait_callback (struct lwp_info *lp, void *data);
762 static int linux_thread_alive (ptid_t ptid);
763 static char *linux_child_pid_to_exec_file (struct target_ops *self, int pid);
764 static int resume_stopped_resumed_lwps (struct lwp_info *lp, void *data);
768 /* Destroy and free LP. */
771 lwp_free (struct lwp_info *lp)
773 xfree (lp->arch_private);
777 /* Remove all LWPs belong to PID from the lwp list. */
780 purge_lwp_list (int pid)
782 struct lwp_info *lp, *lpprev, *lpnext;
786 for (lp = lwp_list; lp; lp = lpnext)
790 if (ptid_get_pid (lp->ptid) == pid)
795 lpprev->next = lp->next;
804 /* Add the LWP specified by PTID to the list. PTID is the first LWP
805 in the process. Return a pointer to the structure describing the
808 This differs from add_lwp in that we don't let the arch specific
809 bits know about this new thread. Current clients of this callback
810 take the opportunity to install watchpoints in the new thread, and
811 we shouldn't do that for the first thread. If we're spawning a
812 child ("run"), the thread executes the shell wrapper first, and we
813 shouldn't touch it until it execs the program we want to debug.
814 For "attach", it'd be okay to call the callback, but it's not
815 necessary, because watchpoints can't yet have been inserted into
818 static struct lwp_info *
819 add_initial_lwp (ptid_t ptid)
823 gdb_assert (ptid_lwp_p (ptid));
825 lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info));
827 memset (lp, 0, sizeof (struct lwp_info));
829 lp->last_resume_kind = resume_continue;
830 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
841 /* Add the LWP specified by PID to the list. Return a pointer to the
842 structure describing the new LWP. The LWP should already be
845 static struct lwp_info *
846 add_lwp (ptid_t ptid)
850 lp = add_initial_lwp (ptid);
852 /* Let the arch specific bits know about this new thread. Current
853 clients of this callback take the opportunity to install
854 watchpoints in the new thread. We don't do this for the first
855 thread though. See add_initial_lwp. */
856 if (linux_nat_new_thread != NULL)
857 linux_nat_new_thread (lp);
862 /* Remove the LWP specified by PID from the list. */
865 delete_lwp (ptid_t ptid)
867 struct lwp_info *lp, *lpprev;
871 for (lp = lwp_list; lp; lpprev = lp, lp = lp->next)
872 if (ptid_equal (lp->ptid, ptid))
879 lpprev->next = lp->next;
886 /* Return a pointer to the structure describing the LWP corresponding
887 to PID. If no corresponding LWP could be found, return NULL. */
889 static struct lwp_info *
890 find_lwp_pid (ptid_t ptid)
895 if (ptid_lwp_p (ptid))
896 lwp = ptid_get_lwp (ptid);
898 lwp = ptid_get_pid (ptid);
900 for (lp = lwp_list; lp; lp = lp->next)
901 if (lwp == ptid_get_lwp (lp->ptid))
907 /* See nat/linux-nat.h. */
910 iterate_over_lwps (ptid_t filter,
911 iterate_over_lwps_ftype callback,
914 struct lwp_info *lp, *lpnext;
916 for (lp = lwp_list; lp; lp = lpnext)
920 if (ptid_match (lp->ptid, filter))
922 if ((*callback) (lp, data) != 0)
930 /* Update our internal state when changing from one checkpoint to
931 another indicated by NEW_PTID. We can only switch single-threaded
932 applications, so we only create one new LWP, and the previous list
936 linux_nat_switch_fork (ptid_t new_ptid)
940 purge_lwp_list (ptid_get_pid (inferior_ptid));
942 lp = add_lwp (new_ptid);
945 /* This changes the thread's ptid while preserving the gdb thread
946 num. Also changes the inferior pid, while preserving the
948 thread_change_ptid (inferior_ptid, new_ptid);
950 /* We've just told GDB core that the thread changed target id, but,
951 in fact, it really is a different thread, with different register
953 registers_changed ();
956 /* Handle the exit of a single thread LP. */
959 exit_lwp (struct lwp_info *lp)
961 struct thread_info *th = find_thread_ptid (lp->ptid);
965 if (print_thread_events)
966 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid));
968 delete_thread (lp->ptid);
971 delete_lwp (lp->ptid);
974 /* Wait for the LWP specified by LP, which we have just attached to.
975 Returns a wait status for that LWP, to cache. */
978 linux_nat_post_attach_wait (ptid_t ptid, int first, int *cloned,
981 pid_t new_pid, pid = ptid_get_lwp (ptid);
984 if (linux_proc_pid_is_stopped (pid))
987 fprintf_unfiltered (gdb_stdlog,
988 "LNPAW: Attaching to a stopped process\n");
990 /* The process is definitely stopped. It is in a job control
991 stop, unless the kernel predates the TASK_STOPPED /
992 TASK_TRACED distinction, in which case it might be in a
993 ptrace stop. Make sure it is in a ptrace stop; from there we
994 can kill it, signal it, et cetera.
996 First make sure there is a pending SIGSTOP. Since we are
997 already attached, the process can not transition from stopped
998 to running without a PTRACE_CONT; so we know this signal will
999 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1000 probably already in the queue (unless this kernel is old
1001 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1002 is not an RT signal, it can only be queued once. */
1003 kill_lwp (pid, SIGSTOP);
1005 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1006 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1007 ptrace (PTRACE_CONT, pid, 0, 0);
1010 /* Make sure the initial process is stopped. The user-level threads
1011 layer might want to poke around in the inferior, and that won't
1012 work if things haven't stabilized yet. */
1013 new_pid = my_waitpid (pid, &status, 0);
1014 if (new_pid == -1 && errno == ECHILD)
1017 warning (_("%s is a cloned process"), target_pid_to_str (ptid));
1019 /* Try again with __WCLONE to check cloned processes. */
1020 new_pid = my_waitpid (pid, &status, __WCLONE);
1024 gdb_assert (pid == new_pid);
1026 if (!WIFSTOPPED (status))
1028 /* The pid we tried to attach has apparently just exited. */
1029 if (debug_linux_nat)
1030 fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s",
1031 pid, status_to_str (status));
1035 if (WSTOPSIG (status) != SIGSTOP)
1038 if (debug_linux_nat)
1039 fprintf_unfiltered (gdb_stdlog,
1040 "LNPAW: Received %s after attaching\n",
1041 status_to_str (status));
1047 /* Attach to the LWP specified by PID. Return 0 if successful, -1 if
1048 the new LWP could not be attached, or 1 if we're already auto
1049 attached to this thread, but haven't processed the
1050 PTRACE_EVENT_CLONE event of its parent thread, so we just ignore
1051 its existance, without considering it an error. */
1054 lin_lwp_attach_lwp (ptid_t ptid)
1056 struct lwp_info *lp;
1059 gdb_assert (ptid_lwp_p (ptid));
1061 lp = find_lwp_pid (ptid);
1062 lwpid = ptid_get_lwp (ptid);
1064 /* We assume that we're already attached to any LWP that is already
1065 in our list of LWPs. If we're not seeing exit events from threads
1066 and we've had PID wraparound since we last tried to stop all threads,
1067 this assumption might be wrong; fortunately, this is very unlikely
1071 int status, cloned = 0, signalled = 0;
1073 if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0)
1075 if (linux_supports_tracefork ())
1077 /* If we haven't stopped all threads when we get here,
1078 we may have seen a thread listed in thread_db's list,
1079 but not processed the PTRACE_EVENT_CLONE yet. If
1080 that's the case, ignore this new thread, and let
1081 normal event handling discover it later. */
1082 if (in_pid_list_p (stopped_pids, lwpid))
1084 /* We've already seen this thread stop, but we
1085 haven't seen the PTRACE_EVENT_CLONE extended
1087 if (debug_linux_nat)
1088 fprintf_unfiltered (gdb_stdlog,
1089 "LLAL: attach failed, but already seen "
1090 "this thread %s stop\n",
1091 target_pid_to_str (ptid));
1099 if (debug_linux_nat)
1100 fprintf_unfiltered (gdb_stdlog,
1101 "LLAL: attach failed, and haven't seen "
1102 "this thread %s stop yet\n",
1103 target_pid_to_str (ptid));
1105 /* We may or may not be attached to the LWP already.
1106 Try waitpid on it. If that errors, we're not
1107 attached to the LWP yet. Otherwise, we're
1108 already attached. */
1109 gdb_assert (lwpid > 0);
1110 new_pid = my_waitpid (lwpid, &status, WNOHANG);
1111 if (new_pid == -1 && errno == ECHILD)
1112 new_pid = my_waitpid (lwpid, &status, __WCLONE | WNOHANG);
1117 /* The child hasn't stopped for its initial
1118 SIGSTOP stop yet. */
1119 if (debug_linux_nat)
1120 fprintf_unfiltered (gdb_stdlog,
1121 "LLAL: child hasn't "
1124 else if (WIFSTOPPED (status))
1126 if (debug_linux_nat)
1127 fprintf_unfiltered (gdb_stdlog,
1128 "LLAL: adding to stopped_pids\n");
1129 add_to_pid_list (&stopped_pids, lwpid, status);
1136 /* If we fail to attach to the thread, issue a warning,
1137 but continue. One way this can happen is if thread
1138 creation is interrupted; as of Linux kernel 2.6.19, a
1139 bug may place threads in the thread list and then fail
1141 warning (_("Can't attach %s: %s"), target_pid_to_str (ptid),
1142 safe_strerror (errno));
1146 if (debug_linux_nat)
1147 fprintf_unfiltered (gdb_stdlog,
1148 "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
1149 target_pid_to_str (ptid));
1151 status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled);
1152 if (!WIFSTOPPED (status))
1155 lp = add_lwp (ptid);
1157 lp->last_resume_kind = resume_stop;
1158 lp->cloned = cloned;
1159 lp->signalled = signalled;
1160 if (WSTOPSIG (status) != SIGSTOP)
1163 lp->status = status;
1166 target_post_attach (ptid_get_lwp (lp->ptid));
1168 if (debug_linux_nat)
1170 fprintf_unfiltered (gdb_stdlog,
1171 "LLAL: waitpid %s received %s\n",
1172 target_pid_to_str (ptid),
1173 status_to_str (status));
1181 linux_nat_create_inferior (struct target_ops *ops,
1182 char *exec_file, char *allargs, char **env,
1185 struct cleanup *restore_personality
1186 = maybe_disable_address_space_randomization (disable_randomization);
1188 /* The fork_child mechanism is synchronous and calls target_wait, so
1189 we have to mask the async mode. */
1191 /* Make sure we report all signals during startup. */
1192 linux_nat_pass_signals (ops, 0, NULL);
1194 linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty);
1196 do_cleanups (restore_personality);
1199 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
1200 already attached. Returns true if a new LWP is found, false
1204 attach_proc_task_lwp_callback (ptid_t ptid)
1206 struct lwp_info *lp;
1208 /* Ignore LWPs we're already attached to. */
1209 lp = find_lwp_pid (ptid);
1212 int lwpid = ptid_get_lwp (ptid);
1214 if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0)
1218 /* Be quiet if we simply raced with the thread exiting.
1219 EPERM is returned if the thread's task still exists, and
1220 is marked as exited or zombie, as well as other
1221 conditions, so in that case, confirm the status in
1222 /proc/PID/status. */
1224 || (err == EPERM && linux_proc_pid_is_gone (lwpid)))
1226 if (debug_linux_nat)
1228 fprintf_unfiltered (gdb_stdlog,
1229 "Cannot attach to lwp %d: "
1230 "thread is gone (%d: %s)\n",
1231 lwpid, err, safe_strerror (err));
1236 warning (_("Cannot attach to lwp %d: %s"),
1238 linux_ptrace_attach_fail_reason_string (ptid,
1244 if (debug_linux_nat)
1245 fprintf_unfiltered (gdb_stdlog,
1246 "PTRACE_ATTACH %s, 0, 0 (OK)\n",
1247 target_pid_to_str (ptid));
1249 lp = add_lwp (ptid);
1252 /* The next time we wait for this LWP we'll see a SIGSTOP as
1253 PTRACE_ATTACH brings it to a halt. */
1256 /* We need to wait for a stop before being able to make the
1257 next ptrace call on this LWP. */
1258 lp->must_set_ptrace_flags = 1;
1267 linux_nat_attach (struct target_ops *ops, const char *args, int from_tty)
1269 struct lwp_info *lp;
1273 /* Make sure we report all signals during attach. */
1274 linux_nat_pass_signals (ops, 0, NULL);
1278 linux_ops->to_attach (ops, args, from_tty);
1280 CATCH (ex, RETURN_MASK_ERROR)
1282 pid_t pid = parse_pid_to_attach (args);
1283 struct buffer buffer;
1284 char *message, *buffer_s;
1286 message = xstrdup (ex.message);
1287 make_cleanup (xfree, message);
1289 buffer_init (&buffer);
1290 linux_ptrace_attach_fail_reason (pid, &buffer);
1292 buffer_grow_str0 (&buffer, "");
1293 buffer_s = buffer_finish (&buffer);
1294 make_cleanup (xfree, buffer_s);
1296 if (*buffer_s != '\0')
1297 throw_error (ex.error, "warning: %s\n%s", buffer_s, message);
1299 throw_error (ex.error, "%s", message);
1303 /* The ptrace base target adds the main thread with (pid,0,0)
1304 format. Decorate it with lwp info. */
1305 ptid = ptid_build (ptid_get_pid (inferior_ptid),
1306 ptid_get_pid (inferior_ptid),
1308 thread_change_ptid (inferior_ptid, ptid);
1310 /* Add the initial process as the first LWP to the list. */
1311 lp = add_initial_lwp (ptid);
1313 status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->cloned,
1315 if (!WIFSTOPPED (status))
1317 if (WIFEXITED (status))
1319 int exit_code = WEXITSTATUS (status);
1321 target_terminal_ours ();
1322 target_mourn_inferior ();
1324 error (_("Unable to attach: program exited normally."));
1326 error (_("Unable to attach: program exited with code %d."),
1329 else if (WIFSIGNALED (status))
1331 enum gdb_signal signo;
1333 target_terminal_ours ();
1334 target_mourn_inferior ();
1336 signo = gdb_signal_from_host (WTERMSIG (status));
1337 error (_("Unable to attach: program terminated with signal "
1339 gdb_signal_to_name (signo),
1340 gdb_signal_to_string (signo));
1343 internal_error (__FILE__, __LINE__,
1344 _("unexpected status %d for PID %ld"),
1345 status, (long) ptid_get_lwp (ptid));
1350 /* Save the wait status to report later. */
1352 if (debug_linux_nat)
1353 fprintf_unfiltered (gdb_stdlog,
1354 "LNA: waitpid %ld, saving status %s\n",
1355 (long) ptid_get_pid (lp->ptid), status_to_str (status));
1357 lp->status = status;
1359 /* We must attach to every LWP. If /proc is mounted, use that to
1360 find them now. The inferior may be using raw clone instead of
1361 using pthreads. But even if it is using pthreads, thread_db
1362 walks structures in the inferior's address space to find the list
1363 of threads/LWPs, and those structures may well be corrupted.
1364 Note that once thread_db is loaded, we'll still use it to list
1365 threads and associate pthread info with each LWP. */
1366 linux_proc_attach_tgid_threads (ptid_get_pid (lp->ptid),
1367 attach_proc_task_lwp_callback);
1369 if (target_can_async_p ())
1373 /* Get pending status of LP. */
1375 get_pending_status (struct lwp_info *lp, int *status)
1377 enum gdb_signal signo = GDB_SIGNAL_0;
1379 /* If we paused threads momentarily, we may have stored pending
1380 events in lp->status or lp->waitstatus (see stop_wait_callback),
1381 and GDB core hasn't seen any signal for those threads.
1382 Otherwise, the last signal reported to the core is found in the
1383 thread object's stop_signal.
1385 There's a corner case that isn't handled here at present. Only
1386 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1387 stop_signal make sense as a real signal to pass to the inferior.
1388 Some catchpoint related events, like
1389 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1390 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1391 those traps are debug API (ptrace in our case) related and
1392 induced; the inferior wouldn't see them if it wasn't being
1393 traced. Hence, we should never pass them to the inferior, even
1394 when set to pass state. Since this corner case isn't handled by
1395 infrun.c when proceeding with a signal, for consistency, neither
1396 do we handle it here (or elsewhere in the file we check for
1397 signal pass state). Normally SIGTRAP isn't set to pass state, so
1398 this is really a corner case. */
1400 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
1401 signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */
1402 else if (lp->status)
1403 signo = gdb_signal_from_host (WSTOPSIG (lp->status));
1404 else if (non_stop && !is_executing (lp->ptid))
1406 struct thread_info *tp = find_thread_ptid (lp->ptid);
1408 signo = tp->suspend.stop_signal;
1412 struct target_waitstatus last;
1415 get_last_target_status (&last_ptid, &last);
1417 if (ptid_get_lwp (lp->ptid) == ptid_get_lwp (last_ptid))
1419 struct thread_info *tp = find_thread_ptid (lp->ptid);
1421 signo = tp->suspend.stop_signal;
1427 if (signo == GDB_SIGNAL_0)
1429 if (debug_linux_nat)
1430 fprintf_unfiltered (gdb_stdlog,
1431 "GPT: lwp %s has no pending signal\n",
1432 target_pid_to_str (lp->ptid));
1434 else if (!signal_pass_state (signo))
1436 if (debug_linux_nat)
1437 fprintf_unfiltered (gdb_stdlog,
1438 "GPT: lwp %s had signal %s, "
1439 "but it is in no pass state\n",
1440 target_pid_to_str (lp->ptid),
1441 gdb_signal_to_string (signo));
1445 *status = W_STOPCODE (gdb_signal_to_host (signo));
1447 if (debug_linux_nat)
1448 fprintf_unfiltered (gdb_stdlog,
1449 "GPT: lwp %s has pending signal %s\n",
1450 target_pid_to_str (lp->ptid),
1451 gdb_signal_to_string (signo));
1458 detach_callback (struct lwp_info *lp, void *data)
1460 gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status));
1462 if (debug_linux_nat && lp->status)
1463 fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n",
1464 strsignal (WSTOPSIG (lp->status)),
1465 target_pid_to_str (lp->ptid));
1467 /* If there is a pending SIGSTOP, get rid of it. */
1470 if (debug_linux_nat)
1471 fprintf_unfiltered (gdb_stdlog,
1472 "DC: Sending SIGCONT to %s\n",
1473 target_pid_to_str (lp->ptid));
1475 kill_lwp (ptid_get_lwp (lp->ptid), SIGCONT);
1479 /* We don't actually detach from the LWP that has an id equal to the
1480 overall process id just yet. */
1481 if (ptid_get_lwp (lp->ptid) != ptid_get_pid (lp->ptid))
1485 /* Pass on any pending signal for this LWP. */
1486 get_pending_status (lp, &status);
1488 if (linux_nat_prepare_to_resume != NULL)
1489 linux_nat_prepare_to_resume (lp);
1491 if (ptrace (PTRACE_DETACH, ptid_get_lwp (lp->ptid), 0,
1492 WSTOPSIG (status)) < 0)
1493 error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid),
1494 safe_strerror (errno));
1496 if (debug_linux_nat)
1497 fprintf_unfiltered (gdb_stdlog,
1498 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1499 target_pid_to_str (lp->ptid),
1500 strsignal (WSTOPSIG (status)));
1502 delete_lwp (lp->ptid);
1509 linux_nat_detach (struct target_ops *ops, const char *args, int from_tty)
1513 struct lwp_info *main_lwp;
1515 pid = ptid_get_pid (inferior_ptid);
1517 /* Don't unregister from the event loop, as there may be other
1518 inferiors running. */
1520 /* Stop all threads before detaching. ptrace requires that the
1521 thread is stopped to sucessfully detach. */
1522 iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL);
1523 /* ... and wait until all of them have reported back that
1524 they're no longer running. */
1525 iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL);
1527 iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL);
1529 /* Only the initial process should be left right now. */
1530 gdb_assert (num_lwps (ptid_get_pid (inferior_ptid)) == 1);
1532 main_lwp = find_lwp_pid (pid_to_ptid (pid));
1534 /* Pass on any pending signal for the last LWP. */
1535 if ((args == NULL || *args == '\0')
1536 && get_pending_status (main_lwp, &status) != -1
1537 && WIFSTOPPED (status))
1541 /* Put the signal number in ARGS so that inf_ptrace_detach will
1542 pass it along with PTRACE_DETACH. */
1544 xsnprintf (tem, 8, "%d", (int) WSTOPSIG (status));
1546 if (debug_linux_nat)
1547 fprintf_unfiltered (gdb_stdlog,
1548 "LND: Sending signal %s to %s\n",
1550 target_pid_to_str (main_lwp->ptid));
1553 if (linux_nat_prepare_to_resume != NULL)
1554 linux_nat_prepare_to_resume (main_lwp);
1555 delete_lwp (main_lwp->ptid);
1557 if (forks_exist_p ())
1559 /* Multi-fork case. The current inferior_ptid is being detached
1560 from, but there are other viable forks to debug. Detach from
1561 the current fork, and context-switch to the first
1563 linux_fork_detach (args, from_tty);
1566 linux_ops->to_detach (ops, args, from_tty);
1569 /* Resume execution of the inferior process. If STEP is nonzero,
1570 single-step it. If SIGNAL is nonzero, give it that signal. */
1573 linux_resume_one_lwp_throw (struct lwp_info *lp, int step,
1574 enum gdb_signal signo)
1578 /* stop_pc doubles as the PC the LWP had when it was last resumed.
1579 We only presently need that if the LWP is stepped though (to
1580 handle the case of stepping a breakpoint instruction). */
1583 struct regcache *regcache = get_thread_regcache (lp->ptid);
1585 lp->stop_pc = regcache_read_pc (regcache);
1590 if (linux_nat_prepare_to_resume != NULL)
1591 linux_nat_prepare_to_resume (lp);
1592 linux_ops->to_resume (linux_ops, lp->ptid, step, signo);
1594 /* Successfully resumed. Clear state that no longer makes sense,
1595 and mark the LWP as running. Must not do this before resuming
1596 otherwise if that fails other code will be confused. E.g., we'd
1597 later try to stop the LWP and hang forever waiting for a stop
1598 status. Note that we must not throw after this is cleared,
1599 otherwise handle_zombie_lwp_error would get confused. */
1601 lp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
1602 registers_changed_ptid (lp->ptid);
1605 /* Called when we try to resume a stopped LWP and that errors out. If
1606 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
1607 or about to become), discard the error, clear any pending status
1608 the LWP may have, and return true (we'll collect the exit status
1609 soon enough). Otherwise, return false. */
1612 check_ptrace_stopped_lwp_gone (struct lwp_info *lp)
1614 /* If we get an error after resuming the LWP successfully, we'd
1615 confuse !T state for the LWP being gone. */
1616 gdb_assert (lp->stopped);
1618 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
1619 because even if ptrace failed with ESRCH, the tracee may be "not
1620 yet fully dead", but already refusing ptrace requests. In that
1621 case the tracee has 'R (Running)' state for a little bit
1622 (observed in Linux 3.18). See also the note on ESRCH in the
1623 ptrace(2) man page. Instead, check whether the LWP has any state
1624 other than ptrace-stopped. */
1626 /* Don't assume anything if /proc/PID/status can't be read. */
1627 if (linux_proc_pid_is_trace_stopped_nowarn (ptid_get_lwp (lp->ptid)) == 0)
1629 lp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
1631 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
1637 /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
1638 disappears while we try to resume it. */
1641 linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo)
1645 linux_resume_one_lwp_throw (lp, step, signo);
1647 CATCH (ex, RETURN_MASK_ERROR)
1649 if (!check_ptrace_stopped_lwp_gone (lp))
1650 throw_exception (ex);
1658 resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo)
1662 struct inferior *inf = find_inferior_ptid (lp->ptid);
1664 if (inf->vfork_child != NULL)
1666 if (debug_linux_nat)
1667 fprintf_unfiltered (gdb_stdlog,
1668 "RC: Not resuming %s (vfork parent)\n",
1669 target_pid_to_str (lp->ptid));
1671 else if (!lwp_status_pending_p (lp))
1673 if (debug_linux_nat)
1674 fprintf_unfiltered (gdb_stdlog,
1675 "RC: Resuming sibling %s, %s, %s\n",
1676 target_pid_to_str (lp->ptid),
1677 (signo != GDB_SIGNAL_0
1678 ? strsignal (gdb_signal_to_host (signo))
1680 step ? "step" : "resume");
1682 linux_resume_one_lwp (lp, step, signo);
1686 if (debug_linux_nat)
1687 fprintf_unfiltered (gdb_stdlog,
1688 "RC: Not resuming sibling %s (has pending)\n",
1689 target_pid_to_str (lp->ptid));
1694 if (debug_linux_nat)
1695 fprintf_unfiltered (gdb_stdlog,
1696 "RC: Not resuming sibling %s (not stopped)\n",
1697 target_pid_to_str (lp->ptid));
1701 /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing.
1702 Resume LWP with the last stop signal, if it is in pass state. */
1705 linux_nat_resume_callback (struct lwp_info *lp, void *except)
1707 enum gdb_signal signo = GDB_SIGNAL_0;
1714 struct thread_info *thread;
1716 thread = find_thread_ptid (lp->ptid);
1719 signo = thread->suspend.stop_signal;
1720 thread->suspend.stop_signal = GDB_SIGNAL_0;
1724 resume_lwp (lp, 0, signo);
1729 resume_clear_callback (struct lwp_info *lp, void *data)
1732 lp->last_resume_kind = resume_stop;
1737 resume_set_callback (struct lwp_info *lp, void *data)
1740 lp->last_resume_kind = resume_continue;
1745 linux_nat_resume (struct target_ops *ops,
1746 ptid_t ptid, int step, enum gdb_signal signo)
1748 struct lwp_info *lp;
1751 if (debug_linux_nat)
1752 fprintf_unfiltered (gdb_stdlog,
1753 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1754 step ? "step" : "resume",
1755 target_pid_to_str (ptid),
1756 (signo != GDB_SIGNAL_0
1757 ? strsignal (gdb_signal_to_host (signo)) : "0"),
1758 target_pid_to_str (inferior_ptid));
1760 /* A specific PTID means `step only this process id'. */
1761 resume_many = (ptid_equal (minus_one_ptid, ptid)
1762 || ptid_is_pid (ptid));
1764 /* Mark the lwps we're resuming as resumed. */
1765 iterate_over_lwps (ptid, resume_set_callback, NULL);
1767 /* See if it's the current inferior that should be handled
1770 lp = find_lwp_pid (inferior_ptid);
1772 lp = find_lwp_pid (ptid);
1773 gdb_assert (lp != NULL);
1775 /* Remember if we're stepping. */
1776 lp->last_resume_kind = step ? resume_step : resume_continue;
1778 /* If we have a pending wait status for this thread, there is no
1779 point in resuming the process. But first make sure that
1780 linux_nat_wait won't preemptively handle the event - we
1781 should never take this short-circuit if we are going to
1782 leave LP running, since we have skipped resuming all the
1783 other threads. This bit of code needs to be synchronized
1784 with linux_nat_wait. */
1786 if (lp->status && WIFSTOPPED (lp->status))
1789 && WSTOPSIG (lp->status)
1790 && sigismember (&pass_mask, WSTOPSIG (lp->status)))
1792 if (debug_linux_nat)
1793 fprintf_unfiltered (gdb_stdlog,
1794 "LLR: Not short circuiting for ignored "
1795 "status 0x%x\n", lp->status);
1797 /* FIXME: What should we do if we are supposed to continue
1798 this thread with a signal? */
1799 gdb_assert (signo == GDB_SIGNAL_0);
1800 signo = gdb_signal_from_host (WSTOPSIG (lp->status));
1805 if (lwp_status_pending_p (lp))
1807 /* FIXME: What should we do if we are supposed to continue
1808 this thread with a signal? */
1809 gdb_assert (signo == GDB_SIGNAL_0);
1811 if (debug_linux_nat)
1812 fprintf_unfiltered (gdb_stdlog,
1813 "LLR: Short circuiting for status 0x%x\n",
1816 if (target_can_async_p ())
1819 /* Tell the event loop we have something to process. */
1826 iterate_over_lwps (ptid, linux_nat_resume_callback, lp);
1828 if (debug_linux_nat)
1829 fprintf_unfiltered (gdb_stdlog,
1830 "LLR: %s %s, %s (resume event thread)\n",
1831 step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1832 target_pid_to_str (lp->ptid),
1833 (signo != GDB_SIGNAL_0
1834 ? strsignal (gdb_signal_to_host (signo)) : "0"));
1836 linux_resume_one_lwp (lp, step, signo);
1838 if (target_can_async_p ())
1842 /* Send a signal to an LWP. */
1845 kill_lwp (int lwpid, int signo)
1847 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1848 fails, then we are not using nptl threads and we should be using kill. */
1850 #ifdef HAVE_TKILL_SYSCALL
1852 static int tkill_failed;
1859 ret = syscall (__NR_tkill, lwpid, signo);
1860 if (errno != ENOSYS)
1867 return kill (lwpid, signo);
1870 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1871 event, check if the core is interested in it: if not, ignore the
1872 event, and keep waiting; otherwise, we need to toggle the LWP's
1873 syscall entry/exit status, since the ptrace event itself doesn't
1874 indicate it, and report the trap to higher layers. */
1877 linux_handle_syscall_trap (struct lwp_info *lp, int stopping)
1879 struct target_waitstatus *ourstatus = &lp->waitstatus;
1880 struct gdbarch *gdbarch = target_thread_architecture (lp->ptid);
1881 int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid);
1885 /* If we're stopping threads, there's a SIGSTOP pending, which
1886 makes it so that the LWP reports an immediate syscall return,
1887 followed by the SIGSTOP. Skip seeing that "return" using
1888 PTRACE_CONT directly, and let stop_wait_callback collect the
1889 SIGSTOP. Later when the thread is resumed, a new syscall
1890 entry event. If we didn't do this (and returned 0), we'd
1891 leave a syscall entry pending, and our caller, by using
1892 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1893 itself. Later, when the user re-resumes this LWP, we'd see
1894 another syscall entry event and we'd mistake it for a return.
1896 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1897 (leaving immediately with LWP->signalled set, without issuing
1898 a PTRACE_CONT), it would still be problematic to leave this
1899 syscall enter pending, as later when the thread is resumed,
1900 it would then see the same syscall exit mentioned above,
1901 followed by the delayed SIGSTOP, while the syscall didn't
1902 actually get to execute. It seems it would be even more
1903 confusing to the user. */
1905 if (debug_linux_nat)
1906 fprintf_unfiltered (gdb_stdlog,
1907 "LHST: ignoring syscall %d "
1908 "for LWP %ld (stopping threads), "
1909 "resuming with PTRACE_CONT for SIGSTOP\n",
1911 ptid_get_lwp (lp->ptid));
1913 lp->syscall_state = TARGET_WAITKIND_IGNORE;
1914 ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0);
1919 if (catch_syscall_enabled ())
1921 /* Always update the entry/return state, even if this particular
1922 syscall isn't interesting to the core now. In async mode,
1923 the user could install a new catchpoint for this syscall
1924 between syscall enter/return, and we'll need to know to
1925 report a syscall return if that happens. */
1926 lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
1927 ? TARGET_WAITKIND_SYSCALL_RETURN
1928 : TARGET_WAITKIND_SYSCALL_ENTRY);
1930 if (catching_syscall_number (syscall_number))
1932 /* Alright, an event to report. */
1933 ourstatus->kind = lp->syscall_state;
1934 ourstatus->value.syscall_number = syscall_number;
1936 if (debug_linux_nat)
1937 fprintf_unfiltered (gdb_stdlog,
1938 "LHST: stopping for %s of syscall %d"
1941 == TARGET_WAITKIND_SYSCALL_ENTRY
1942 ? "entry" : "return",
1944 ptid_get_lwp (lp->ptid));
1948 if (debug_linux_nat)
1949 fprintf_unfiltered (gdb_stdlog,
1950 "LHST: ignoring %s of syscall %d "
1952 lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
1953 ? "entry" : "return",
1955 ptid_get_lwp (lp->ptid));
1959 /* If we had been syscall tracing, and hence used PT_SYSCALL
1960 before on this LWP, it could happen that the user removes all
1961 syscall catchpoints before we get to process this event.
1962 There are two noteworthy issues here:
1964 - When stopped at a syscall entry event, resuming with
1965 PT_STEP still resumes executing the syscall and reports a
1968 - Only PT_SYSCALL catches syscall enters. If we last
1969 single-stepped this thread, then this event can't be a
1970 syscall enter. If we last single-stepped this thread, this
1971 has to be a syscall exit.
1973 The points above mean that the next resume, be it PT_STEP or
1974 PT_CONTINUE, can not trigger a syscall trace event. */
1975 if (debug_linux_nat)
1976 fprintf_unfiltered (gdb_stdlog,
1977 "LHST: caught syscall event "
1978 "with no syscall catchpoints."
1979 " %d for LWP %ld, ignoring\n",
1981 ptid_get_lwp (lp->ptid));
1982 lp->syscall_state = TARGET_WAITKIND_IGNORE;
1985 /* The core isn't interested in this event. For efficiency, avoid
1986 stopping all threads only to have the core resume them all again.
1987 Since we're not stopping threads, if we're still syscall tracing
1988 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1989 subsequent syscall. Simply resume using the inf-ptrace layer,
1990 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1992 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
1996 /* Handle a GNU/Linux extended wait response. If we see a clone
1997 event, we need to add the new LWP to our list (and not report the
1998 trap to higher layers). This function returns non-zero if the
1999 event should be ignored and we should wait again. If STOPPING is
2000 true, the new LWP remains stopped, otherwise it is continued. */
2003 linux_handle_extended_wait (struct lwp_info *lp, int status,
2006 int pid = ptid_get_lwp (lp->ptid);
2007 struct target_waitstatus *ourstatus = &lp->waitstatus;
2008 int event = linux_ptrace_get_extended_event (status);
2010 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK
2011 || event == PTRACE_EVENT_CLONE)
2013 unsigned long new_pid;
2016 ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid);
2018 /* If we haven't already seen the new PID stop, wait for it now. */
2019 if (! pull_pid_from_list (&stopped_pids, new_pid, &status))
2021 /* The new child has a pending SIGSTOP. We can't affect it until it
2022 hits the SIGSTOP, but we're already attached. */
2023 ret = my_waitpid (new_pid, &status,
2024 (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0);
2026 perror_with_name (_("waiting for new child"));
2027 else if (ret != new_pid)
2028 internal_error (__FILE__, __LINE__,
2029 _("wait returned unexpected PID %d"), ret);
2030 else if (!WIFSTOPPED (status))
2031 internal_error (__FILE__, __LINE__,
2032 _("wait returned unexpected status 0x%x"), status);
2035 ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0);
2037 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK)
2039 /* The arch-specific native code may need to know about new
2040 forks even if those end up never mapped to an
2042 if (linux_nat_new_fork != NULL)
2043 linux_nat_new_fork (lp, new_pid);
2046 if (event == PTRACE_EVENT_FORK
2047 && linux_fork_checkpointing_p (ptid_get_pid (lp->ptid)))
2049 /* Handle checkpointing by linux-fork.c here as a special
2050 case. We don't want the follow-fork-mode or 'catch fork'
2051 to interfere with this. */
2053 /* This won't actually modify the breakpoint list, but will
2054 physically remove the breakpoints from the child. */
2055 detach_breakpoints (ptid_build (new_pid, new_pid, 0));
2057 /* Retain child fork in ptrace (stopped) state. */
2058 if (!find_fork_pid (new_pid))
2061 /* Report as spurious, so that infrun doesn't want to follow
2062 this fork. We're actually doing an infcall in
2064 ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
2066 /* Report the stop to the core. */
2070 if (event == PTRACE_EVENT_FORK)
2071 ourstatus->kind = TARGET_WAITKIND_FORKED;
2072 else if (event == PTRACE_EVENT_VFORK)
2073 ourstatus->kind = TARGET_WAITKIND_VFORKED;
2076 struct lwp_info *new_lp;
2078 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2080 if (debug_linux_nat)
2081 fprintf_unfiltered (gdb_stdlog,
2082 "LHEW: Got clone event "
2083 "from LWP %d, new child is LWP %ld\n",
2086 new_lp = add_lwp (ptid_build (ptid_get_pid (lp->ptid), new_pid, 0));
2088 new_lp->stopped = 1;
2090 if (WSTOPSIG (status) != SIGSTOP)
2092 /* This can happen if someone starts sending signals to
2093 the new thread before it gets a chance to run, which
2094 have a lower number than SIGSTOP (e.g. SIGUSR1).
2095 This is an unlikely case, and harder to handle for
2096 fork / vfork than for clone, so we do not try - but
2097 we handle it for clone events here. We'll send
2098 the other signal on to the thread below. */
2100 new_lp->signalled = 1;
2104 struct thread_info *tp;
2106 /* When we stop for an event in some other thread, and
2107 pull the thread list just as this thread has cloned,
2108 we'll have seen the new thread in the thread_db list
2109 before handling the CLONE event (glibc's
2110 pthread_create adds the new thread to the thread list
2111 before clone'ing, and has the kernel fill in the
2112 thread's tid on the clone call with
2113 CLONE_PARENT_SETTID). If that happened, and the core
2114 had requested the new thread to stop, we'll have
2115 killed it with SIGSTOP. But since SIGSTOP is not an
2116 RT signal, it can only be queued once. We need to be
2117 careful to not resume the LWP if we wanted it to
2118 stop. In that case, we'll leave the SIGSTOP pending.
2119 It will later be reported as GDB_SIGNAL_0. */
2120 tp = find_thread_ptid (new_lp->ptid);
2121 if (tp != NULL && tp->stop_requested)
2122 new_lp->last_resume_kind = resume_stop;
2127 /* If the thread_db layer is active, let it record the user
2128 level thread id and status, and add the thread to GDB's
2130 if (!thread_db_notice_clone (lp->ptid, new_lp->ptid))
2132 /* The process is not using thread_db. Add the LWP to
2134 target_post_attach (ptid_get_lwp (new_lp->ptid));
2135 add_thread (new_lp->ptid);
2138 /* Even if we're stopping the thread for some reason
2139 internal to this module, from the user/frontend's
2140 perspective, this new thread is running. */
2141 set_running (new_lp->ptid, 1);
2144 set_executing (new_lp->ptid, 1);
2145 /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced
2147 new_lp->last_resume_kind = resume_continue;
2152 /* We created NEW_LP so it cannot yet contain STATUS. */
2153 gdb_assert (new_lp->status == 0);
2155 /* Save the wait status to report later. */
2156 if (debug_linux_nat)
2157 fprintf_unfiltered (gdb_stdlog,
2158 "LHEW: waitpid of new LWP %ld, "
2159 "saving status %s\n",
2160 (long) ptid_get_lwp (new_lp->ptid),
2161 status_to_str (status));
2162 new_lp->status = status;
2165 new_lp->resumed = !stopping;
2172 if (event == PTRACE_EVENT_EXEC)
2174 if (debug_linux_nat)
2175 fprintf_unfiltered (gdb_stdlog,
2176 "LHEW: Got exec event from LWP %ld\n",
2177 ptid_get_lwp (lp->ptid));
2179 ourstatus->kind = TARGET_WAITKIND_EXECD;
2180 ourstatus->value.execd_pathname
2181 = xstrdup (linux_child_pid_to_exec_file (NULL, pid));
2183 /* The thread that execed must have been resumed, but, when a
2184 thread execs, it changes its tid to the tgid, and the old
2185 tgid thread might have not been resumed. */
2190 if (event == PTRACE_EVENT_VFORK_DONE)
2192 if (current_inferior ()->waiting_for_vfork_done)
2194 if (debug_linux_nat)
2195 fprintf_unfiltered (gdb_stdlog,
2196 "LHEW: Got expected PTRACE_EVENT_"
2197 "VFORK_DONE from LWP %ld: stopping\n",
2198 ptid_get_lwp (lp->ptid));
2200 ourstatus->kind = TARGET_WAITKIND_VFORK_DONE;
2204 if (debug_linux_nat)
2205 fprintf_unfiltered (gdb_stdlog,
2206 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2207 "from LWP %ld: ignoring\n",
2208 ptid_get_lwp (lp->ptid));
2212 internal_error (__FILE__, __LINE__,
2213 _("unknown ptrace event %d"), event);
2216 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2220 wait_lwp (struct lwp_info *lp)
2224 int thread_dead = 0;
2227 gdb_assert (!lp->stopped);
2228 gdb_assert (lp->status == 0);
2230 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2231 block_child_signals (&prev_mask);
2235 /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind
2236 was right and we should just call sigsuspend. */
2238 pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, WNOHANG);
2239 if (pid == -1 && errno == ECHILD)
2240 pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, __WCLONE | WNOHANG);
2241 if (pid == -1 && errno == ECHILD)
2243 /* The thread has previously exited. We need to delete it
2244 now because, for some vendor 2.4 kernels with NPTL
2245 support backported, there won't be an exit event unless
2246 it is the main thread. 2.6 kernels will report an exit
2247 event for each thread that exits, as expected. */
2249 if (debug_linux_nat)
2250 fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
2251 target_pid_to_str (lp->ptid));
2256 /* Bugs 10970, 12702.
2257 Thread group leader may have exited in which case we'll lock up in
2258 waitpid if there are other threads, even if they are all zombies too.
2259 Basically, we're not supposed to use waitpid this way.
2260 __WCLONE is not applicable for the leader so we can't use that.
2261 LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED
2262 process; it gets ESRCH both for the zombie and for running processes.
2264 As a workaround, check if we're waiting for the thread group leader and
2265 if it's a zombie, and avoid calling waitpid if it is.
2267 This is racy, what if the tgl becomes a zombie right after we check?
2268 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2269 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2271 if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid)
2272 && linux_proc_pid_is_zombie (ptid_get_lwp (lp->ptid)))
2275 if (debug_linux_nat)
2276 fprintf_unfiltered (gdb_stdlog,
2277 "WL: Thread group leader %s vanished.\n",
2278 target_pid_to_str (lp->ptid));
2282 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2283 get invoked despite our caller had them intentionally blocked by
2284 block_child_signals. This is sensitive only to the loop of
2285 linux_nat_wait_1 and there if we get called my_waitpid gets called
2286 again before it gets to sigsuspend so we can safely let the handlers
2287 get executed here. */
2289 if (debug_linux_nat)
2290 fprintf_unfiltered (gdb_stdlog, "WL: about to sigsuspend\n");
2291 sigsuspend (&suspend_mask);
2294 restore_child_signals_mask (&prev_mask);
2298 gdb_assert (pid == ptid_get_lwp (lp->ptid));
2300 if (debug_linux_nat)
2302 fprintf_unfiltered (gdb_stdlog,
2303 "WL: waitpid %s received %s\n",
2304 target_pid_to_str (lp->ptid),
2305 status_to_str (status));
2308 /* Check if the thread has exited. */
2309 if (WIFEXITED (status) || WIFSIGNALED (status))
2312 if (debug_linux_nat)
2313 fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n",
2314 target_pid_to_str (lp->ptid));
2324 gdb_assert (WIFSTOPPED (status));
2327 if (lp->must_set_ptrace_flags)
2329 struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid));
2330 int options = linux_nat_ptrace_options (inf->attach_flag);
2332 linux_enable_event_reporting (ptid_get_lwp (lp->ptid), options);
2333 lp->must_set_ptrace_flags = 0;
2336 /* Handle GNU/Linux's syscall SIGTRAPs. */
2337 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
2339 /* No longer need the sysgood bit. The ptrace event ends up
2340 recorded in lp->waitstatus if we care for it. We can carry
2341 on handling the event like a regular SIGTRAP from here
2343 status = W_STOPCODE (SIGTRAP);
2344 if (linux_handle_syscall_trap (lp, 1))
2345 return wait_lwp (lp);
2348 /* Handle GNU/Linux's extended waitstatus for trace events. */
2349 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP
2350 && linux_is_extended_waitstatus (status))
2352 if (debug_linux_nat)
2353 fprintf_unfiltered (gdb_stdlog,
2354 "WL: Handling extended status 0x%06x\n",
2356 linux_handle_extended_wait (lp, status, 1);
2363 /* Send a SIGSTOP to LP. */
2366 stop_callback (struct lwp_info *lp, void *data)
2368 if (!lp->stopped && !lp->signalled)
2372 if (debug_linux_nat)
2374 fprintf_unfiltered (gdb_stdlog,
2375 "SC: kill %s **<SIGSTOP>**\n",
2376 target_pid_to_str (lp->ptid));
2379 ret = kill_lwp (ptid_get_lwp (lp->ptid), SIGSTOP);
2380 if (debug_linux_nat)
2382 fprintf_unfiltered (gdb_stdlog,
2383 "SC: lwp kill %d %s\n",
2385 errno ? safe_strerror (errno) : "ERRNO-OK");
2389 gdb_assert (lp->status == 0);
2395 /* Request a stop on LWP. */
2398 linux_stop_lwp (struct lwp_info *lwp)
2400 stop_callback (lwp, NULL);
2403 /* See linux-nat.h */
2406 linux_stop_and_wait_all_lwps (void)
2408 /* Stop all LWP's ... */
2409 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
2411 /* ... and wait until all of them have reported back that
2412 they're no longer running. */
2413 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
2416 /* See linux-nat.h */
2419 linux_unstop_all_lwps (void)
2421 iterate_over_lwps (minus_one_ptid,
2422 resume_stopped_resumed_lwps, &minus_one_ptid);
2425 /* Return non-zero if LWP PID has a pending SIGINT. */
2428 linux_nat_has_pending_sigint (int pid)
2430 sigset_t pending, blocked, ignored;
2432 linux_proc_pending_signals (pid, &pending, &blocked, &ignored);
2434 if (sigismember (&pending, SIGINT)
2435 && !sigismember (&ignored, SIGINT))
2441 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2444 set_ignore_sigint (struct lwp_info *lp, void *data)
2446 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2447 flag to consume the next one. */
2448 if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status)
2449 && WSTOPSIG (lp->status) == SIGINT)
2452 lp->ignore_sigint = 1;
2457 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2458 This function is called after we know the LWP has stopped; if the LWP
2459 stopped before the expected SIGINT was delivered, then it will never have
2460 arrived. Also, if the signal was delivered to a shared queue and consumed
2461 by a different thread, it will never be delivered to this LWP. */
2464 maybe_clear_ignore_sigint (struct lwp_info *lp)
2466 if (!lp->ignore_sigint)
2469 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp->ptid)))
2471 if (debug_linux_nat)
2472 fprintf_unfiltered (gdb_stdlog,
2473 "MCIS: Clearing bogus flag for %s\n",
2474 target_pid_to_str (lp->ptid));
2475 lp->ignore_sigint = 0;
2479 /* Fetch the possible triggered data watchpoint info and store it in
2482 On some archs, like x86, that use debug registers to set
2483 watchpoints, it's possible that the way to know which watched
2484 address trapped, is to check the register that is used to select
2485 which address to watch. Problem is, between setting the watchpoint
2486 and reading back which data address trapped, the user may change
2487 the set of watchpoints, and, as a consequence, GDB changes the
2488 debug registers in the inferior. To avoid reading back a stale
2489 stopped-data-address when that happens, we cache in LP the fact
2490 that a watchpoint trapped, and the corresponding data address, as
2491 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2492 registers meanwhile, we have the cached data we can rely on. */
2495 check_stopped_by_watchpoint (struct lwp_info *lp)
2497 struct cleanup *old_chain;
2499 if (linux_ops->to_stopped_by_watchpoint == NULL)
2502 old_chain = save_inferior_ptid ();
2503 inferior_ptid = lp->ptid;
2505 if (linux_ops->to_stopped_by_watchpoint (linux_ops))
2507 lp->stop_reason = TARGET_STOPPED_BY_WATCHPOINT;
2509 if (linux_ops->to_stopped_data_address != NULL)
2510 lp->stopped_data_address_p =
2511 linux_ops->to_stopped_data_address (¤t_target,
2512 &lp->stopped_data_address);
2514 lp->stopped_data_address_p = 0;
2517 do_cleanups (old_chain);
2519 return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
2522 /* Called when the LWP stopped for a trap that could be explained by a
2523 watchpoint or a breakpoint. */
2526 save_sigtrap (struct lwp_info *lp)
2528 gdb_assert (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON);
2529 gdb_assert (lp->status != 0);
2531 /* Check first if this was a SW/HW breakpoint before checking
2532 watchpoints, because at least s390 can't tell the data address of
2533 hardware watchpoint hits, and the kernel returns
2534 stopped-by-watchpoint as long as there's a watchpoint set. */
2535 if (linux_nat_status_is_event (lp->status))
2536 check_stopped_by_breakpoint (lp);
2538 /* Note that TRAP_HWBKPT can indicate either a hardware breakpoint
2539 or hardware watchpoint. Check which is which if we got
2540 TARGET_STOPPED_BY_HW_BREAKPOINT. */
2541 if (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON
2542 || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)
2543 check_stopped_by_watchpoint (lp);
2546 /* Returns true if the LWP had stopped for a watchpoint. */
2549 linux_nat_stopped_by_watchpoint (struct target_ops *ops)
2551 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2553 gdb_assert (lp != NULL);
2555 return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
2559 linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
2561 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2563 gdb_assert (lp != NULL);
2565 *addr_p = lp->stopped_data_address;
2567 return lp->stopped_data_address_p;
2570 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2573 sigtrap_is_event (int status)
2575 return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP;
2578 /* Set alternative SIGTRAP-like events recognizer. If
2579 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2583 linux_nat_set_status_is_event (struct target_ops *t,
2584 int (*status_is_event) (int status))
2586 linux_nat_status_is_event = status_is_event;
2589 /* Wait until LP is stopped. */
2592 stop_wait_callback (struct lwp_info *lp, void *data)
2594 struct inferior *inf = find_inferior_ptid (lp->ptid);
2596 /* If this is a vfork parent, bail out, it is not going to report
2597 any SIGSTOP until the vfork is done with. */
2598 if (inf->vfork_child != NULL)
2605 status = wait_lwp (lp);
2609 if (lp->ignore_sigint && WIFSTOPPED (status)
2610 && WSTOPSIG (status) == SIGINT)
2612 lp->ignore_sigint = 0;
2615 ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0);
2617 if (debug_linux_nat)
2618 fprintf_unfiltered (gdb_stdlog,
2619 "PTRACE_CONT %s, 0, 0 (%s) "
2620 "(discarding SIGINT)\n",
2621 target_pid_to_str (lp->ptid),
2622 errno ? safe_strerror (errno) : "OK");
2624 return stop_wait_callback (lp, NULL);
2627 maybe_clear_ignore_sigint (lp);
2629 if (WSTOPSIG (status) != SIGSTOP)
2631 /* The thread was stopped with a signal other than SIGSTOP. */
2633 if (debug_linux_nat)
2634 fprintf_unfiltered (gdb_stdlog,
2635 "SWC: Pending event %s in %s\n",
2636 status_to_str ((int) status),
2637 target_pid_to_str (lp->ptid));
2639 /* Save the sigtrap event. */
2640 lp->status = status;
2641 gdb_assert (lp->signalled);
2646 /* We caught the SIGSTOP that we intended to catch, so
2647 there's no SIGSTOP pending. */
2649 if (debug_linux_nat)
2650 fprintf_unfiltered (gdb_stdlog,
2651 "SWC: Expected SIGSTOP caught for %s.\n",
2652 target_pid_to_str (lp->ptid));
2654 /* Reset SIGNALLED only after the stop_wait_callback call
2655 above as it does gdb_assert on SIGNALLED. */
2663 /* Return non-zero if LP has a wait status pending. Discard the
2664 pending event and resume the LWP if the event that originally
2665 caused the stop became uninteresting. */
2668 status_callback (struct lwp_info *lp, void *data)
2670 /* Only report a pending wait status if we pretend that this has
2671 indeed been resumed. */
2675 if (!lwp_status_pending_p (lp))
2678 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
2679 || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)
2681 struct regcache *regcache = get_thread_regcache (lp->ptid);
2682 struct gdbarch *gdbarch = get_regcache_arch (regcache);
2686 pc = regcache_read_pc (regcache);
2688 if (pc != lp->stop_pc)
2690 if (debug_linux_nat)
2691 fprintf_unfiltered (gdb_stdlog,
2692 "SC: PC of %s changed. was=%s, now=%s\n",
2693 target_pid_to_str (lp->ptid),
2694 paddress (target_gdbarch (), lp->stop_pc),
2695 paddress (target_gdbarch (), pc));
2699 #if !USE_SIGTRAP_SIGINFO
2700 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
2702 if (debug_linux_nat)
2703 fprintf_unfiltered (gdb_stdlog,
2704 "SC: previous breakpoint of %s, at %s gone\n",
2705 target_pid_to_str (lp->ptid),
2706 paddress (target_gdbarch (), lp->stop_pc));
2714 if (debug_linux_nat)
2715 fprintf_unfiltered (gdb_stdlog,
2716 "SC: pending event of %s cancelled.\n",
2717 target_pid_to_str (lp->ptid));
2720 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
2728 /* Return non-zero if LP isn't stopped. */
2731 running_callback (struct lwp_info *lp, void *data)
2733 return (!lp->stopped
2734 || (lwp_status_pending_p (lp) && lp->resumed));
2737 /* Count the LWP's that have had events. */
2740 count_events_callback (struct lwp_info *lp, void *data)
2744 gdb_assert (count != NULL);
2746 /* Select only resumed LWPs that have an event pending. */
2747 if (lp->resumed && lwp_status_pending_p (lp))
2753 /* Select the LWP (if any) that is currently being single-stepped. */
2756 select_singlestep_lwp_callback (struct lwp_info *lp, void *data)
2758 if (lp->last_resume_kind == resume_step
2765 /* Returns true if LP has a status pending. */
2768 lwp_status_pending_p (struct lwp_info *lp)
2770 /* We check for lp->waitstatus in addition to lp->status, because we
2771 can have pending process exits recorded in lp->status and
2772 W_EXITCODE(0,0) happens to be 0. */
2773 return lp->status != 0 || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE;
2776 /* Select the Nth LWP that has had an event. */
2779 select_event_lwp_callback (struct lwp_info *lp, void *data)
2781 int *selector = data;
2783 gdb_assert (selector != NULL);
2785 /* Select only resumed LWPs that have an event pending. */
2786 if (lp->resumed && lwp_status_pending_p (lp))
2787 if ((*selector)-- == 0)
2793 /* Called when the LWP got a signal/trap that could be explained by a
2794 software or hardware breakpoint. */
2797 check_stopped_by_breakpoint (struct lwp_info *lp)
2799 /* Arrange for a breakpoint to be hit again later. We don't keep
2800 the SIGTRAP status and don't forward the SIGTRAP signal to the
2801 LWP. We will handle the current event, eventually we will resume
2802 this LWP, and this breakpoint will trap again.
2804 If we do not do this, then we run the risk that the user will
2805 delete or disable the breakpoint, but the LWP will have already
2808 struct regcache *regcache = get_thread_regcache (lp->ptid);
2809 struct gdbarch *gdbarch = get_regcache_arch (regcache);
2812 #if USE_SIGTRAP_SIGINFO
2816 pc = regcache_read_pc (regcache);
2817 sw_bp_pc = pc - gdbarch_decr_pc_after_break (gdbarch);
2819 #if USE_SIGTRAP_SIGINFO
2820 if (linux_nat_get_siginfo (lp->ptid, &siginfo))
2822 if (siginfo.si_signo == SIGTRAP)
2824 if (siginfo.si_code == GDB_ARCH_TRAP_BRKPT)
2826 if (debug_linux_nat)
2827 fprintf_unfiltered (gdb_stdlog,
2828 "CSBB: %s stopped by software "
2830 target_pid_to_str (lp->ptid));
2832 /* Back up the PC if necessary. */
2834 regcache_write_pc (regcache, sw_bp_pc);
2836 lp->stop_pc = sw_bp_pc;
2837 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2840 else if (siginfo.si_code == TRAP_HWBKPT)
2842 if (debug_linux_nat)
2843 fprintf_unfiltered (gdb_stdlog,
2844 "CSBB: %s stopped by hardware "
2845 "breakpoint/watchpoint\n",
2846 target_pid_to_str (lp->ptid));
2849 lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
2852 else if (siginfo.si_code == TRAP_TRACE)
2854 if (debug_linux_nat)
2855 fprintf_unfiltered (gdb_stdlog,
2856 "CSBB: %s stopped by trace\n",
2857 target_pid_to_str (lp->ptid));
2862 if ((!lp->step || lp->stop_pc == sw_bp_pc)
2863 && software_breakpoint_inserted_here_p (get_regcache_aspace (regcache),
2866 /* The LWP was either continued, or stepped a software
2867 breakpoint instruction. */
2868 if (debug_linux_nat)
2869 fprintf_unfiltered (gdb_stdlog,
2870 "CSBB: %s stopped by software breakpoint\n",
2871 target_pid_to_str (lp->ptid));
2873 /* Back up the PC if necessary. */
2875 regcache_write_pc (regcache, sw_bp_pc);
2877 lp->stop_pc = sw_bp_pc;
2878 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2882 if (hardware_breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
2884 if (debug_linux_nat)
2885 fprintf_unfiltered (gdb_stdlog,
2886 "CSBB: stopped by hardware breakpoint %s\n",
2887 target_pid_to_str (lp->ptid));
2890 lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
2899 /* Returns true if the LWP had stopped for a software breakpoint. */
2902 linux_nat_stopped_by_sw_breakpoint (struct target_ops *ops)
2904 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2906 gdb_assert (lp != NULL);
2908 return lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT;
2911 /* Implement the supports_stopped_by_sw_breakpoint method. */
2914 linux_nat_supports_stopped_by_sw_breakpoint (struct target_ops *ops)
2916 return USE_SIGTRAP_SIGINFO;
2919 /* Returns true if the LWP had stopped for a hardware
2920 breakpoint/watchpoint. */
2923 linux_nat_stopped_by_hw_breakpoint (struct target_ops *ops)
2925 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2927 gdb_assert (lp != NULL);
2929 return lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT;
2932 /* Implement the supports_stopped_by_hw_breakpoint method. */
2935 linux_nat_supports_stopped_by_hw_breakpoint (struct target_ops *ops)
2937 return USE_SIGTRAP_SIGINFO;
2940 /* Select one LWP out of those that have events pending. */
2943 select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status)
2946 int random_selector;
2947 struct lwp_info *event_lp = NULL;
2949 /* Record the wait status for the original LWP. */
2950 (*orig_lp)->status = *status;
2952 /* In all-stop, give preference to the LWP that is being
2953 single-stepped. There will be at most one, and it will be the
2954 LWP that the core is most interested in. If we didn't do this,
2955 then we'd have to handle pending step SIGTRAPs somehow in case
2956 the core later continues the previously-stepped thread, as
2957 otherwise we'd report the pending SIGTRAP then, and the core, not
2958 having stepped the thread, wouldn't understand what the trap was
2959 for, and therefore would report it to the user as a random
2963 event_lp = iterate_over_lwps (filter,
2964 select_singlestep_lwp_callback, NULL);
2965 if (event_lp != NULL)
2967 if (debug_linux_nat)
2968 fprintf_unfiltered (gdb_stdlog,
2969 "SEL: Select single-step %s\n",
2970 target_pid_to_str (event_lp->ptid));
2974 if (event_lp == NULL)
2976 /* Pick one at random, out of those which have had events. */
2978 /* First see how many events we have. */
2979 iterate_over_lwps (filter, count_events_callback, &num_events);
2980 gdb_assert (num_events > 0);
2982 /* Now randomly pick a LWP out of those that have had
2984 random_selector = (int)
2985 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
2987 if (debug_linux_nat && num_events > 1)
2988 fprintf_unfiltered (gdb_stdlog,
2989 "SEL: Found %d events, selecting #%d\n",
2990 num_events, random_selector);
2992 event_lp = iterate_over_lwps (filter,
2993 select_event_lwp_callback,
2997 if (event_lp != NULL)
2999 /* Switch the event LWP. */
3000 *orig_lp = event_lp;
3001 *status = event_lp->status;
3004 /* Flush the wait status for the event LWP. */
3005 (*orig_lp)->status = 0;
3008 /* Return non-zero if LP has been resumed. */
3011 resumed_callback (struct lwp_info *lp, void *data)
3016 /* Stop an active thread, verify it still exists, then resume it. If
3017 the thread ends up with a pending status, then it is not resumed,
3018 and *DATA (really a pointer to int), is set. */
3021 stop_and_resume_callback (struct lwp_info *lp, void *data)
3025 ptid_t ptid = lp->ptid;
3027 stop_callback (lp, NULL);
3028 stop_wait_callback (lp, NULL);
3030 /* Resume if the lwp still exists, and the core wanted it
3032 lp = find_lwp_pid (ptid);
3035 if (lp->last_resume_kind == resume_stop
3036 && !lwp_status_pending_p (lp))
3038 /* The core wanted the LWP to stop. Even if it stopped
3039 cleanly (with SIGSTOP), leave the event pending. */
3040 if (debug_linux_nat)
3041 fprintf_unfiltered (gdb_stdlog,
3042 "SARC: core wanted LWP %ld stopped "
3043 "(leaving SIGSTOP pending)\n",
3044 ptid_get_lwp (lp->ptid));
3045 lp->status = W_STOPCODE (SIGSTOP);
3048 if (!lwp_status_pending_p (lp))
3050 if (debug_linux_nat)
3051 fprintf_unfiltered (gdb_stdlog,
3052 "SARC: re-resuming LWP %ld\n",
3053 ptid_get_lwp (lp->ptid));
3054 resume_lwp (lp, lp->step, GDB_SIGNAL_0);
3058 if (debug_linux_nat)
3059 fprintf_unfiltered (gdb_stdlog,
3060 "SARC: not re-resuming LWP %ld "
3062 ptid_get_lwp (lp->ptid));
3069 /* Check if we should go on and pass this event to common code.
3070 Return the affected lwp if we are, or NULL otherwise. */
3072 static struct lwp_info *
3073 linux_nat_filter_event (int lwpid, int status)
3075 struct lwp_info *lp;
3076 int event = linux_ptrace_get_extended_event (status);
3078 lp = find_lwp_pid (pid_to_ptid (lwpid));
3080 /* Check for stop events reported by a process we didn't already
3081 know about - anything not already in our LWP list.
3083 If we're expecting to receive stopped processes after
3084 fork, vfork, and clone events, then we'll just add the
3085 new one to our list and go back to waiting for the event
3086 to be reported - the stopped process might be returned
3087 from waitpid before or after the event is.
3089 But note the case of a non-leader thread exec'ing after the
3090 leader having exited, and gone from our lists. The non-leader
3091 thread changes its tid to the tgid. */
3093 if (WIFSTOPPED (status) && lp == NULL
3094 && (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC))
3096 /* A multi-thread exec after we had seen the leader exiting. */
3097 if (debug_linux_nat)
3098 fprintf_unfiltered (gdb_stdlog,
3099 "LLW: Re-adding thread group leader LWP %d.\n",
3102 lp = add_lwp (ptid_build (lwpid, lwpid, 0));
3105 add_thread (lp->ptid);
3108 if (WIFSTOPPED (status) && !lp)
3110 if (debug_linux_nat)
3111 fprintf_unfiltered (gdb_stdlog,
3112 "LHEW: saving LWP %ld status %s in stopped_pids list\n",
3113 (long) lwpid, status_to_str (status));
3114 add_to_pid_list (&stopped_pids, lwpid, status);
3118 /* Make sure we don't report an event for the exit of an LWP not in
3119 our list, i.e. not part of the current process. This can happen
3120 if we detach from a program we originally forked and then it
3122 if (!WIFSTOPPED (status) && !lp)
3125 /* This LWP is stopped now. (And if dead, this prevents it from
3126 ever being continued.) */
3129 if (WIFSTOPPED (status) && lp->must_set_ptrace_flags)
3131 struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid));
3132 int options = linux_nat_ptrace_options (inf->attach_flag);
3134 linux_enable_event_reporting (ptid_get_lwp (lp->ptid), options);
3135 lp->must_set_ptrace_flags = 0;
3138 /* Handle GNU/Linux's syscall SIGTRAPs. */
3139 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
3141 /* No longer need the sysgood bit. The ptrace event ends up
3142 recorded in lp->waitstatus if we care for it. We can carry
3143 on handling the event like a regular SIGTRAP from here
3145 status = W_STOPCODE (SIGTRAP);
3146 if (linux_handle_syscall_trap (lp, 0))
3150 /* Handle GNU/Linux's extended waitstatus for trace events. */
3151 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP
3152 && linux_is_extended_waitstatus (status))
3154 if (debug_linux_nat)
3155 fprintf_unfiltered (gdb_stdlog,
3156 "LLW: Handling extended status 0x%06x\n",
3158 if (linux_handle_extended_wait (lp, status, 0))
3162 /* Check if the thread has exited. */
3163 if (WIFEXITED (status) || WIFSIGNALED (status))
3165 if (num_lwps (ptid_get_pid (lp->ptid)) > 1)
3167 /* If this is the main thread, we must stop all threads and
3168 verify if they are still alive. This is because in the
3169 nptl thread model on Linux 2.4, there is no signal issued
3170 for exiting LWPs other than the main thread. We only get
3171 the main thread exit signal once all child threads have
3172 already exited. If we stop all the threads and use the
3173 stop_wait_callback to check if they have exited we can
3174 determine whether this signal should be ignored or
3175 whether it means the end of the debugged application,
3176 regardless of which threading model is being used. */
3177 if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid))
3179 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp->ptid)),
3180 stop_and_resume_callback, NULL);
3183 if (debug_linux_nat)
3184 fprintf_unfiltered (gdb_stdlog,
3185 "LLW: %s exited.\n",
3186 target_pid_to_str (lp->ptid));
3188 if (num_lwps (ptid_get_pid (lp->ptid)) > 1)
3190 /* If there is at least one more LWP, then the exit signal
3191 was not the end of the debugged application and should be
3198 gdb_assert (lp->resumed);
3200 if (debug_linux_nat)
3201 fprintf_unfiltered (gdb_stdlog,
3202 "Process %ld exited\n",
3203 ptid_get_lwp (lp->ptid));
3205 /* This was the last lwp in the process. Since events are
3206 serialized to GDB core, we may not be able report this one
3207 right now, but GDB core and the other target layers will want
3208 to be notified about the exit code/signal, leave the status
3209 pending for the next time we're able to report it. */
3211 /* Dead LWP's aren't expected to reported a pending sigstop. */
3214 /* Store the pending event in the waitstatus, because
3215 W_EXITCODE(0,0) == 0. */
3216 store_waitstatus (&lp->waitstatus, status);
3220 /* Check if the current LWP has previously exited. In the nptl
3221 thread model, LWPs other than the main thread do not issue
3222 signals when they exit so we must check whenever the thread has
3223 stopped. A similar check is made in stop_wait_callback(). */
3224 if (num_lwps (ptid_get_pid (lp->ptid)) > 1 && !linux_thread_alive (lp->ptid))
3226 ptid_t ptid = pid_to_ptid (ptid_get_pid (lp->ptid));
3228 if (debug_linux_nat)
3229 fprintf_unfiltered (gdb_stdlog,
3230 "LLW: %s exited.\n",
3231 target_pid_to_str (lp->ptid));
3235 /* Make sure there is at least one thread running. */
3236 gdb_assert (iterate_over_lwps (ptid, running_callback, NULL));
3238 /* Discard the event. */
3242 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3243 an attempt to stop an LWP. */
3245 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP)
3249 if (lp->last_resume_kind == resume_stop)
3251 if (debug_linux_nat)
3252 fprintf_unfiltered (gdb_stdlog,
3253 "LLW: resume_stop SIGSTOP caught for %s.\n",
3254 target_pid_to_str (lp->ptid));
3258 /* This is a delayed SIGSTOP. Filter out the event. */
3260 if (debug_linux_nat)
3261 fprintf_unfiltered (gdb_stdlog,
3262 "LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
3264 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3265 target_pid_to_str (lp->ptid));
3267 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
3268 gdb_assert (lp->resumed);
3273 /* Make sure we don't report a SIGINT that we have already displayed
3274 for another thread. */
3275 if (lp->ignore_sigint
3276 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT)
3278 if (debug_linux_nat)
3279 fprintf_unfiltered (gdb_stdlog,
3280 "LLW: Delayed SIGINT caught for %s.\n",
3281 target_pid_to_str (lp->ptid));
3283 /* This is a delayed SIGINT. */
3284 lp->ignore_sigint = 0;
3286 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
3287 if (debug_linux_nat)
3288 fprintf_unfiltered (gdb_stdlog,
3289 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3291 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3292 target_pid_to_str (lp->ptid));
3293 gdb_assert (lp->resumed);
3295 /* Discard the event. */
3299 /* Don't report signals that GDB isn't interested in, such as
3300 signals that are neither printed nor stopped upon. Stopping all
3301 threads can be a bit time-consuming so if we want decent
3302 performance with heavily multi-threaded programs, especially when
3303 they're using a high frequency timer, we'd better avoid it if we
3305 if (WIFSTOPPED (status))
3307 enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status));
3311 /* Only do the below in all-stop, as we currently use SIGSTOP
3312 to implement target_stop (see linux_nat_stop) in
3314 if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0)
3316 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3317 forwarded to the entire process group, that is, all LWPs
3318 will receive it - unless they're using CLONE_THREAD to
3319 share signals. Since we only want to report it once, we
3320 mark it as ignored for all LWPs except this one. */
3321 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp->ptid)),
3322 set_ignore_sigint, NULL);
3323 lp->ignore_sigint = 0;
3326 maybe_clear_ignore_sigint (lp);
3329 /* When using hardware single-step, we need to report every signal.
3330 Otherwise, signals in pass_mask may be short-circuited
3331 except signals that might be caused by a breakpoint. */
3333 && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status))
3334 && !linux_wstatus_maybe_breakpoint (status))
3336 linux_resume_one_lwp (lp, lp->step, signo);
3337 if (debug_linux_nat)
3338 fprintf_unfiltered (gdb_stdlog,
3339 "LLW: %s %s, %s (preempt 'handle')\n",
3341 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3342 target_pid_to_str (lp->ptid),
3343 (signo != GDB_SIGNAL_0
3344 ? strsignal (gdb_signal_to_host (signo))
3350 /* An interesting event. */
3352 lp->status = status;
3357 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3358 their exits until all other threads in the group have exited. */
3361 check_zombie_leaders (void)
3363 struct inferior *inf;
3367 struct lwp_info *leader_lp;
3372 leader_lp = find_lwp_pid (pid_to_ptid (inf->pid));
3373 if (leader_lp != NULL
3374 /* Check if there are other threads in the group, as we may
3375 have raced with the inferior simply exiting. */
3376 && num_lwps (inf->pid) > 1
3377 && linux_proc_pid_is_zombie (inf->pid))
3379 if (debug_linux_nat)
3380 fprintf_unfiltered (gdb_stdlog,
3381 "CZL: Thread group leader %d zombie "
3382 "(it exited, or another thread execd).\n",
3385 /* A leader zombie can mean one of two things:
3387 - It exited, and there's an exit status pending
3388 available, or only the leader exited (not the whole
3389 program). In the latter case, we can't waitpid the
3390 leader's exit status until all other threads are gone.
3392 - There are 3 or more threads in the group, and a thread
3393 other than the leader exec'd. On an exec, the Linux
3394 kernel destroys all other threads (except the execing
3395 one) in the thread group, and resets the execing thread's
3396 tid to the tgid. No exit notification is sent for the
3397 execing thread -- from the ptracer's perspective, it
3398 appears as though the execing thread just vanishes.
3399 Until we reap all other threads except the leader and the
3400 execing thread, the leader will be zombie, and the
3401 execing thread will be in `D (disc sleep)'. As soon as
3402 all other threads are reaped, the execing thread changes
3403 it's tid to the tgid, and the previous (zombie) leader
3404 vanishes, giving place to the "new" leader. We could try
3405 distinguishing the exit and exec cases, by waiting once
3406 more, and seeing if something comes out, but it doesn't
3407 sound useful. The previous leader _does_ go away, and
3408 we'll re-add the new one once we see the exec event
3409 (which is just the same as what would happen if the
3410 previous leader did exit voluntarily before some other
3413 if (debug_linux_nat)
3414 fprintf_unfiltered (gdb_stdlog,
3415 "CZL: Thread group leader %d vanished.\n",
3417 exit_lwp (leader_lp);
3423 linux_nat_wait_1 (struct target_ops *ops,
3424 ptid_t ptid, struct target_waitstatus *ourstatus,
3428 enum resume_kind last_resume_kind;
3429 struct lwp_info *lp;
3432 if (debug_linux_nat)
3433 fprintf_unfiltered (gdb_stdlog, "LLW: enter\n");
3435 /* The first time we get here after starting a new inferior, we may
3436 not have added it to the LWP list yet - this is the earliest
3437 moment at which we know its PID. */
3438 if (ptid_is_pid (inferior_ptid))
3440 /* Upgrade the main thread's ptid. */
3441 thread_change_ptid (inferior_ptid,
3442 ptid_build (ptid_get_pid (inferior_ptid),
3443 ptid_get_pid (inferior_ptid), 0));
3445 lp = add_initial_lwp (inferior_ptid);
3449 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3450 block_child_signals (&prev_mask);
3452 /* First check if there is a LWP with a wait status pending. */
3453 lp = iterate_over_lwps (ptid, status_callback, NULL);
3456 if (debug_linux_nat)
3457 fprintf_unfiltered (gdb_stdlog,
3458 "LLW: Using pending wait status %s for %s.\n",
3459 status_to_str (lp->status),
3460 target_pid_to_str (lp->ptid));
3463 if (!target_is_async_p ())
3465 /* Causes SIGINT to be passed on to the attached process. */
3469 /* But if we don't find a pending event, we'll have to wait. Always
3470 pull all events out of the kernel. We'll randomly select an
3471 event LWP out of all that have events, to prevent starvation. */
3477 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3480 - If the thread group leader exits while other threads in the
3481 thread group still exist, waitpid(TGID, ...) hangs. That
3482 waitpid won't return an exit status until the other threads
3483 in the group are reapped.
3485 - When a non-leader thread execs, that thread just vanishes
3486 without reporting an exit (so we'd hang if we waited for it
3487 explicitly in that case). The exec event is reported to
3491 lwpid = my_waitpid (-1, &status, __WCLONE | WNOHANG);
3492 if (lwpid == 0 || (lwpid == -1 && errno == ECHILD))
3493 lwpid = my_waitpid (-1, &status, WNOHANG);
3495 if (debug_linux_nat)
3496 fprintf_unfiltered (gdb_stdlog,
3497 "LNW: waitpid(-1, ...) returned %d, %s\n",
3498 lwpid, errno ? safe_strerror (errno) : "ERRNO-OK");
3502 if (debug_linux_nat)
3504 fprintf_unfiltered (gdb_stdlog,
3505 "LLW: waitpid %ld received %s\n",
3506 (long) lwpid, status_to_str (status));
3509 linux_nat_filter_event (lwpid, status);
3510 /* Retry until nothing comes out of waitpid. A single
3511 SIGCHLD can indicate more than one child stopped. */
3515 /* Now that we've pulled all events out of the kernel, resume
3516 LWPs that don't have an interesting event to report. */
3517 iterate_over_lwps (minus_one_ptid,
3518 resume_stopped_resumed_lwps, &minus_one_ptid);
3520 /* ... and find an LWP with a status to report to the core, if
3522 lp = iterate_over_lwps (ptid, status_callback, NULL);
3526 /* Check for zombie thread group leaders. Those can't be reaped
3527 until all other threads in the thread group are. */
3528 check_zombie_leaders ();
3530 /* If there are no resumed children left, bail. We'd be stuck
3531 forever in the sigsuspend call below otherwise. */
3532 if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL)
3534 if (debug_linux_nat)
3535 fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n");
3537 ourstatus->kind = TARGET_WAITKIND_NO_RESUMED;
3539 if (!target_is_async_p ())
3540 clear_sigint_trap ();
3542 restore_child_signals_mask (&prev_mask);
3543 return minus_one_ptid;
3546 /* No interesting event to report to the core. */
3548 if (target_options & TARGET_WNOHANG)
3550 if (debug_linux_nat)
3551 fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
3553 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3554 restore_child_signals_mask (&prev_mask);
3555 return minus_one_ptid;
3558 /* We shouldn't end up here unless we want to try again. */
3559 gdb_assert (lp == NULL);
3561 /* Block until we get an event reported with SIGCHLD. */
3562 if (debug_linux_nat)
3563 fprintf_unfiltered (gdb_stdlog, "LNW: about to sigsuspend\n");
3564 sigsuspend (&suspend_mask);
3567 if (!target_is_async_p ())
3568 clear_sigint_trap ();
3572 status = lp->status;
3577 /* Now stop all other LWP's ... */
3578 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
3580 /* ... and wait until all of them have reported back that
3581 they're no longer running. */
3582 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
3585 /* If we're not waiting for a specific LWP, choose an event LWP from
3586 among those that have had events. Giving equal priority to all
3587 LWPs that have had events helps prevent starvation. */
3588 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3589 select_event_lwp (ptid, &lp, &status);
3591 gdb_assert (lp != NULL);
3593 /* Now that we've selected our final event LWP, un-adjust its PC if
3594 it was a software breakpoint, and we can't reliably support the
3595 "stopped by software breakpoint" stop reason. */
3596 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3597 && !USE_SIGTRAP_SIGINFO)
3599 struct regcache *regcache = get_thread_regcache (lp->ptid);
3600 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3601 int decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3607 pc = regcache_read_pc (regcache);
3608 regcache_write_pc (regcache, pc + decr_pc);
3612 /* We'll need this to determine whether to report a SIGSTOP as
3613 GDB_SIGNAL_0. Need to take a copy because resume_clear_callback
3615 last_resume_kind = lp->last_resume_kind;
3619 /* In all-stop, from the core's perspective, all LWPs are now
3620 stopped until a new resume action is sent over. */
3621 iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL);
3625 resume_clear_callback (lp, NULL);
3628 if (linux_nat_status_is_event (status))
3630 if (debug_linux_nat)
3631 fprintf_unfiltered (gdb_stdlog,
3632 "LLW: trap ptid is %s.\n",
3633 target_pid_to_str (lp->ptid));
3636 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
3638 *ourstatus = lp->waitstatus;
3639 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
3642 store_waitstatus (ourstatus, status);
3644 if (debug_linux_nat)
3645 fprintf_unfiltered (gdb_stdlog, "LLW: exit\n");
3647 restore_child_signals_mask (&prev_mask);
3649 if (last_resume_kind == resume_stop
3650 && ourstatus->kind == TARGET_WAITKIND_STOPPED
3651 && WSTOPSIG (status) == SIGSTOP)
3653 /* A thread that has been requested to stop by GDB with
3654 target_stop, and it stopped cleanly, so report as SIG0. The
3655 use of SIGSTOP is an implementation detail. */
3656 ourstatus->value.sig = GDB_SIGNAL_0;
3659 if (ourstatus->kind == TARGET_WAITKIND_EXITED
3660 || ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
3663 lp->core = linux_common_core_of_thread (lp->ptid);
3668 /* Resume LWPs that are currently stopped without any pending status
3669 to report, but are resumed from the core's perspective. */
3672 resume_stopped_resumed_lwps (struct lwp_info *lp, void *data)
3674 ptid_t *wait_ptid_p = data;
3678 && !lwp_status_pending_p (lp))
3680 struct regcache *regcache = get_thread_regcache (lp->ptid);
3681 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3685 CORE_ADDR pc = regcache_read_pc (regcache);
3686 int leave_stopped = 0;
3688 /* Don't bother if there's a breakpoint at PC that we'd hit
3689 immediately, and we're not waiting for this LWP. */
3690 if (!ptid_match (lp->ptid, *wait_ptid_p))
3692 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
3698 if (debug_linux_nat)
3699 fprintf_unfiltered (gdb_stdlog,
3700 "RSRL: resuming stopped-resumed LWP %s at "
3702 target_pid_to_str (lp->ptid),
3703 paddress (gdbarch, pc),
3706 linux_resume_one_lwp_throw (lp, lp->step, GDB_SIGNAL_0);
3709 CATCH (ex, RETURN_MASK_ERROR)
3711 if (!check_ptrace_stopped_lwp_gone (lp))
3712 throw_exception (ex);
3721 linux_nat_wait (struct target_ops *ops,
3722 ptid_t ptid, struct target_waitstatus *ourstatus,
3727 if (debug_linux_nat)
3729 char *options_string;
3731 options_string = target_options_to_string (target_options);
3732 fprintf_unfiltered (gdb_stdlog,
3733 "linux_nat_wait: [%s], [%s]\n",
3734 target_pid_to_str (ptid),
3736 xfree (options_string);
3739 /* Flush the async file first. */
3740 if (target_is_async_p ())
3741 async_file_flush ();
3743 /* Resume LWPs that are currently stopped without any pending status
3744 to report, but are resumed from the core's perspective. LWPs get
3745 in this state if we find them stopping at a time we're not
3746 interested in reporting the event (target_wait on a
3747 specific_process, for example, see linux_nat_wait_1), and
3748 meanwhile the event became uninteresting. Don't bother resuming
3749 LWPs we're not going to wait for if they'd stop immediately. */
3751 iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid);
3753 event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options);
3755 /* If we requested any event, and something came out, assume there
3756 may be more. If we requested a specific lwp or process, also
3757 assume there may be more. */
3758 if (target_is_async_p ()
3759 && ((ourstatus->kind != TARGET_WAITKIND_IGNORE
3760 && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED)
3761 || !ptid_equal (ptid, minus_one_ptid)))
3768 kill_callback (struct lwp_info *lp, void *data)
3770 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3773 kill_lwp (ptid_get_lwp (lp->ptid), SIGKILL);
3774 if (debug_linux_nat)
3776 int save_errno = errno;
3778 fprintf_unfiltered (gdb_stdlog,
3779 "KC: kill (SIGKILL) %s, 0, 0 (%s)\n",
3780 target_pid_to_str (lp->ptid),
3781 save_errno ? safe_strerror (save_errno) : "OK");
3784 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3787 ptrace (PTRACE_KILL, ptid_get_lwp (lp->ptid), 0, 0);
3788 if (debug_linux_nat)
3790 int save_errno = errno;
3792 fprintf_unfiltered (gdb_stdlog,
3793 "KC: PTRACE_KILL %s, 0, 0 (%s)\n",
3794 target_pid_to_str (lp->ptid),
3795 save_errno ? safe_strerror (save_errno) : "OK");
3802 kill_wait_callback (struct lwp_info *lp, void *data)
3806 /* We must make sure that there are no pending events (delayed
3807 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3808 program doesn't interfere with any following debugging session. */
3810 /* For cloned processes we must check both with __WCLONE and
3811 without, since the exit status of a cloned process isn't reported
3817 pid = my_waitpid (ptid_get_lwp (lp->ptid), NULL, __WCLONE);
3818 if (pid != (pid_t) -1)
3820 if (debug_linux_nat)
3821 fprintf_unfiltered (gdb_stdlog,
3822 "KWC: wait %s received unknown.\n",
3823 target_pid_to_str (lp->ptid));
3824 /* The Linux kernel sometimes fails to kill a thread
3825 completely after PTRACE_KILL; that goes from the stop
3826 point in do_fork out to the one in
3827 get_signal_to_deliever and waits again. So kill it
3829 kill_callback (lp, NULL);
3832 while (pid == ptid_get_lwp (lp->ptid));
3834 gdb_assert (pid == -1 && errno == ECHILD);
3839 pid = my_waitpid (ptid_get_lwp (lp->ptid), NULL, 0);
3840 if (pid != (pid_t) -1)
3842 if (debug_linux_nat)
3843 fprintf_unfiltered (gdb_stdlog,
3844 "KWC: wait %s received unk.\n",
3845 target_pid_to_str (lp->ptid));
3846 /* See the call to kill_callback above. */
3847 kill_callback (lp, NULL);
3850 while (pid == ptid_get_lwp (lp->ptid));
3852 gdb_assert (pid == -1 && errno == ECHILD);
3857 linux_nat_kill (struct target_ops *ops)
3859 struct target_waitstatus last;
3863 /* If we're stopped while forking and we haven't followed yet,
3864 kill the other task. We need to do this first because the
3865 parent will be sleeping if this is a vfork. */
3867 get_last_target_status (&last_ptid, &last);
3869 if (last.kind == TARGET_WAITKIND_FORKED
3870 || last.kind == TARGET_WAITKIND_VFORKED)
3872 ptrace (PT_KILL, ptid_get_pid (last.value.related_pid), 0, 0);
3875 /* Let the arch-specific native code know this process is
3877 linux_nat_forget_process (ptid_get_pid (last.value.related_pid));
3880 if (forks_exist_p ())
3881 linux_fork_killall ();
3884 ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
3886 /* Stop all threads before killing them, since ptrace requires
3887 that the thread is stopped to sucessfully PTRACE_KILL. */
3888 iterate_over_lwps (ptid, stop_callback, NULL);
3889 /* ... and wait until all of them have reported back that
3890 they're no longer running. */
3891 iterate_over_lwps (ptid, stop_wait_callback, NULL);
3893 /* Kill all LWP's ... */
3894 iterate_over_lwps (ptid, kill_callback, NULL);
3896 /* ... and wait until we've flushed all events. */
3897 iterate_over_lwps (ptid, kill_wait_callback, NULL);
3900 target_mourn_inferior ();
3904 linux_nat_mourn_inferior (struct target_ops *ops)
3906 int pid = ptid_get_pid (inferior_ptid);
3908 purge_lwp_list (pid);
3910 if (! forks_exist_p ())
3911 /* Normal case, no other forks available. */
3912 linux_ops->to_mourn_inferior (ops);
3914 /* Multi-fork case. The current inferior_ptid has exited, but
3915 there are other viable forks to debug. Delete the exiting
3916 one and context-switch to the first available. */
3917 linux_fork_mourn_inferior ();
3919 /* Let the arch-specific native code know this process is gone. */
3920 linux_nat_forget_process (pid);
3923 /* Convert a native/host siginfo object, into/from the siginfo in the
3924 layout of the inferiors' architecture. */
3927 siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction)
3931 if (linux_nat_siginfo_fixup != NULL)
3932 done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction);
3934 /* If there was no callback, or the callback didn't do anything,
3935 then just do a straight memcpy. */
3939 memcpy (siginfo, inf_siginfo, sizeof (siginfo_t));
3941 memcpy (inf_siginfo, siginfo, sizeof (siginfo_t));
3945 static enum target_xfer_status
3946 linux_xfer_siginfo (struct target_ops *ops, enum target_object object,
3947 const char *annex, gdb_byte *readbuf,
3948 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
3949 ULONGEST *xfered_len)
3953 gdb_byte inf_siginfo[sizeof (siginfo_t)];
3955 gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO);
3956 gdb_assert (readbuf || writebuf);
3958 pid = ptid_get_lwp (inferior_ptid);
3960 pid = ptid_get_pid (inferior_ptid);
3962 if (offset > sizeof (siginfo))
3963 return TARGET_XFER_E_IO;
3966 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3968 return TARGET_XFER_E_IO;
3970 /* When GDB is built as a 64-bit application, ptrace writes into
3971 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3972 inferior with a 64-bit GDB should look the same as debugging it
3973 with a 32-bit GDB, we need to convert it. GDB core always sees
3974 the converted layout, so any read/write will have to be done
3976 siginfo_fixup (&siginfo, inf_siginfo, 0);
3978 if (offset + len > sizeof (siginfo))
3979 len = sizeof (siginfo) - offset;
3981 if (readbuf != NULL)
3982 memcpy (readbuf, inf_siginfo + offset, len);
3985 memcpy (inf_siginfo + offset, writebuf, len);
3987 /* Convert back to ptrace layout before flushing it out. */
3988 siginfo_fixup (&siginfo, inf_siginfo, 1);
3991 ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3993 return TARGET_XFER_E_IO;
3997 return TARGET_XFER_OK;
4000 static enum target_xfer_status
4001 linux_nat_xfer_partial (struct target_ops *ops, enum target_object object,
4002 const char *annex, gdb_byte *readbuf,
4003 const gdb_byte *writebuf,
4004 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
4006 struct cleanup *old_chain;
4007 enum target_xfer_status xfer;
4009 if (object == TARGET_OBJECT_SIGNAL_INFO)
4010 return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf,
4011 offset, len, xfered_len);
4013 /* The target is connected but no live inferior is selected. Pass
4014 this request down to a lower stratum (e.g., the executable
4016 if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid))
4017 return TARGET_XFER_EOF;
4019 old_chain = save_inferior_ptid ();
4021 if (ptid_lwp_p (inferior_ptid))
4022 inferior_ptid = pid_to_ptid (ptid_get_lwp (inferior_ptid));
4024 xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf,
4025 offset, len, xfered_len);
4027 do_cleanups (old_chain);
4032 linux_thread_alive (ptid_t ptid)
4036 gdb_assert (ptid_lwp_p (ptid));
4038 /* Send signal 0 instead of anything ptrace, because ptracing a
4039 running thread errors out claiming that the thread doesn't
4041 err = kill_lwp (ptid_get_lwp (ptid), 0);
4043 if (debug_linux_nat)
4044 fprintf_unfiltered (gdb_stdlog,
4045 "LLTA: KILL(SIG0) %s (%s)\n",
4046 target_pid_to_str (ptid),
4047 err ? safe_strerror (tmp_errno) : "OK");
4056 linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid)
4058 return linux_thread_alive (ptid);
4061 /* Implement the to_update_thread_list target method for this
4065 linux_nat_update_thread_list (struct target_ops *ops)
4067 if (linux_supports_traceclone ())
4069 /* With support for clone events, we add/delete threads from the
4070 list as clone/exit events are processed, so just try deleting
4071 exited threads still in the thread list. */
4072 delete_exited_threads ();
4079 linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid)
4081 static char buf[64];
4083 if (ptid_lwp_p (ptid)
4084 && (ptid_get_pid (ptid) != ptid_get_lwp (ptid)
4085 || num_lwps (ptid_get_pid (ptid)) > 1))
4087 snprintf (buf, sizeof (buf), "LWP %ld", ptid_get_lwp (ptid));
4091 return normal_pid_to_str (ptid);
4095 linux_nat_thread_name (struct target_ops *self, struct thread_info *thr)
4097 int pid = ptid_get_pid (thr->ptid);
4098 long lwp = ptid_get_lwp (thr->ptid);
4099 #define FORMAT "/proc/%d/task/%ld/comm"
4100 char buf[sizeof (FORMAT) + 30];
4102 char *result = NULL;
4104 snprintf (buf, sizeof (buf), FORMAT, pid, lwp);
4105 comm_file = gdb_fopen_cloexec (buf, "r");
4108 /* Not exported by the kernel, so we define it here. */
4110 static char line[COMM_LEN + 1];
4112 if (fgets (line, sizeof (line), comm_file))
4114 char *nl = strchr (line, '\n');
4131 /* Accepts an integer PID; Returns a string representing a file that
4132 can be opened to get the symbols for the child process. */
4135 linux_child_pid_to_exec_file (struct target_ops *self, int pid)
4137 return linux_proc_pid_to_exec_file (pid);
4140 /* Implement the to_xfer_partial interface for memory reads using the /proc
4141 filesystem. Because we can use a single read() call for /proc, this
4142 can be much more efficient than banging away at PTRACE_PEEKTEXT,
4143 but it doesn't support writes. */
4145 static enum target_xfer_status
4146 linux_proc_xfer_partial (struct target_ops *ops, enum target_object object,
4147 const char *annex, gdb_byte *readbuf,
4148 const gdb_byte *writebuf,
4149 ULONGEST offset, LONGEST len, ULONGEST *xfered_len)
4155 if (object != TARGET_OBJECT_MEMORY || !readbuf)
4158 /* Don't bother for one word. */
4159 if (len < 3 * sizeof (long))
4160 return TARGET_XFER_EOF;
4162 /* We could keep this file open and cache it - possibly one per
4163 thread. That requires some juggling, but is even faster. */
4164 xsnprintf (filename, sizeof filename, "/proc/%d/mem",
4165 ptid_get_pid (inferior_ptid));
4166 fd = gdb_open_cloexec (filename, O_RDONLY | O_LARGEFILE, 0);
4168 return TARGET_XFER_EOF;
4170 /* If pread64 is available, use it. It's faster if the kernel
4171 supports it (only one syscall), and it's 64-bit safe even on
4172 32-bit platforms (for instance, SPARC debugging a SPARC64
4175 if (pread64 (fd, readbuf, len, offset) != len)
4177 if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len)
4186 return TARGET_XFER_EOF;
4190 return TARGET_XFER_OK;
4195 /* Enumerate spufs IDs for process PID. */
4197 spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, ULONGEST len)
4199 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
4201 LONGEST written = 0;
4204 struct dirent *entry;
4206 xsnprintf (path, sizeof path, "/proc/%d/fd", pid);
4207 dir = opendir (path);
4212 while ((entry = readdir (dir)) != NULL)
4218 fd = atoi (entry->d_name);
4222 xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd);
4223 if (stat (path, &st) != 0)
4225 if (!S_ISDIR (st.st_mode))
4228 if (statfs (path, &stfs) != 0)
4230 if (stfs.f_type != SPUFS_MAGIC)
4233 if (pos >= offset && pos + 4 <= offset + len)
4235 store_unsigned_integer (buf + pos - offset, 4, byte_order, fd);
4245 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4246 object type, using the /proc file system. */
4248 static enum target_xfer_status
4249 linux_proc_xfer_spu (struct target_ops *ops, enum target_object object,
4250 const char *annex, gdb_byte *readbuf,
4251 const gdb_byte *writebuf,
4252 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
4257 int pid = ptid_get_pid (inferior_ptid);
4262 return TARGET_XFER_E_IO;
4265 LONGEST l = spu_enumerate_spu_ids (pid, readbuf, offset, len);
4268 return TARGET_XFER_E_IO;
4270 return TARGET_XFER_EOF;
4273 *xfered_len = (ULONGEST) l;
4274 return TARGET_XFER_OK;
4279 xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex);
4280 fd = gdb_open_cloexec (buf, writebuf? O_WRONLY : O_RDONLY, 0);
4282 return TARGET_XFER_E_IO;
4285 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
4288 return TARGET_XFER_EOF;
4292 ret = write (fd, writebuf, (size_t) len);
4294 ret = read (fd, readbuf, (size_t) len);
4299 return TARGET_XFER_E_IO;
4301 return TARGET_XFER_EOF;
4304 *xfered_len = (ULONGEST) ret;
4305 return TARGET_XFER_OK;
4310 /* Parse LINE as a signal set and add its set bits to SIGS. */
4313 add_line_to_sigset (const char *line, sigset_t *sigs)
4315 int len = strlen (line) - 1;
4319 if (line[len] != '\n')
4320 error (_("Could not parse signal set: %s"), line);
4328 if (*p >= '0' && *p <= '9')
4330 else if (*p >= 'a' && *p <= 'f')
4331 digit = *p - 'a' + 10;
4333 error (_("Could not parse signal set: %s"), line);
4338 sigaddset (sigs, signum + 1);
4340 sigaddset (sigs, signum + 2);
4342 sigaddset (sigs, signum + 3);
4344 sigaddset (sigs, signum + 4);
4350 /* Find process PID's pending signals from /proc/pid/status and set
4354 linux_proc_pending_signals (int pid, sigset_t *pending,
4355 sigset_t *blocked, sigset_t *ignored)
4358 char buffer[PATH_MAX], fname[PATH_MAX];
4359 struct cleanup *cleanup;
4361 sigemptyset (pending);
4362 sigemptyset (blocked);
4363 sigemptyset (ignored);
4364 xsnprintf (fname, sizeof fname, "/proc/%d/status", pid);
4365 procfile = gdb_fopen_cloexec (fname, "r");
4366 if (procfile == NULL)
4367 error (_("Could not open %s"), fname);
4368 cleanup = make_cleanup_fclose (procfile);
4370 while (fgets (buffer, PATH_MAX, procfile) != NULL)
4372 /* Normal queued signals are on the SigPnd line in the status
4373 file. However, 2.6 kernels also have a "shared" pending
4374 queue for delivering signals to a thread group, so check for
4377 Unfortunately some Red Hat kernels include the shared pending
4378 queue but not the ShdPnd status field. */
4380 if (startswith (buffer, "SigPnd:\t"))
4381 add_line_to_sigset (buffer + 8, pending);
4382 else if (startswith (buffer, "ShdPnd:\t"))
4383 add_line_to_sigset (buffer + 8, pending);
4384 else if (startswith (buffer, "SigBlk:\t"))
4385 add_line_to_sigset (buffer + 8, blocked);
4386 else if (startswith (buffer, "SigIgn:\t"))
4387 add_line_to_sigset (buffer + 8, ignored);
4390 do_cleanups (cleanup);
4393 static enum target_xfer_status
4394 linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object,
4395 const char *annex, gdb_byte *readbuf,
4396 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
4397 ULONGEST *xfered_len)
4399 gdb_assert (object == TARGET_OBJECT_OSDATA);
4401 *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len);
4402 if (*xfered_len == 0)
4403 return TARGET_XFER_EOF;
4405 return TARGET_XFER_OK;
4408 static enum target_xfer_status
4409 linux_xfer_partial (struct target_ops *ops, enum target_object object,
4410 const char *annex, gdb_byte *readbuf,
4411 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
4412 ULONGEST *xfered_len)
4414 enum target_xfer_status xfer;
4416 if (object == TARGET_OBJECT_AUXV)
4417 return memory_xfer_auxv (ops, object, annex, readbuf, writebuf,
4418 offset, len, xfered_len);
4420 if (object == TARGET_OBJECT_OSDATA)
4421 return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf,
4422 offset, len, xfered_len);
4424 if (object == TARGET_OBJECT_SPU)
4425 return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf,
4426 offset, len, xfered_len);
4428 /* GDB calculates all the addresses in possibly larget width of the address.
4429 Address width needs to be masked before its final use - either by
4430 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4432 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4434 if (object == TARGET_OBJECT_MEMORY)
4436 int addr_bit = gdbarch_addr_bit (target_gdbarch ());
4438 if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT))
4439 offset &= ((ULONGEST) 1 << addr_bit) - 1;
4442 xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf,
4443 offset, len, xfered_len);
4444 if (xfer != TARGET_XFER_EOF)
4447 return super_xfer_partial (ops, object, annex, readbuf, writebuf,
4448 offset, len, xfered_len);
4452 cleanup_target_stop (void *arg)
4454 ptid_t *ptid = (ptid_t *) arg;
4456 gdb_assert (arg != NULL);
4459 target_resume (*ptid, 0, GDB_SIGNAL_0);
4462 static VEC(static_tracepoint_marker_p) *
4463 linux_child_static_tracepoint_markers_by_strid (struct target_ops *self,
4466 char s[IPA_CMD_BUF_SIZE];
4467 struct cleanup *old_chain;
4468 int pid = ptid_get_pid (inferior_ptid);
4469 VEC(static_tracepoint_marker_p) *markers = NULL;
4470 struct static_tracepoint_marker *marker = NULL;
4472 ptid_t ptid = ptid_build (pid, 0, 0);
4477 memcpy (s, "qTfSTM", sizeof ("qTfSTM"));
4478 s[sizeof ("qTfSTM")] = 0;
4480 agent_run_command (pid, s, strlen (s) + 1);
4482 old_chain = make_cleanup (free_current_marker, &marker);
4483 make_cleanup (cleanup_target_stop, &ptid);
4488 marker = XCNEW (struct static_tracepoint_marker);
4492 parse_static_tracepoint_marker_definition (p, &p, marker);
4494 if (strid == NULL || strcmp (strid, marker->str_id) == 0)
4496 VEC_safe_push (static_tracepoint_marker_p,
4502 release_static_tracepoint_marker (marker);
4503 memset (marker, 0, sizeof (*marker));
4506 while (*p++ == ','); /* comma-separated list */
4508 memcpy (s, "qTsSTM", sizeof ("qTsSTM"));
4509 s[sizeof ("qTsSTM")] = 0;
4510 agent_run_command (pid, s, strlen (s) + 1);
4514 do_cleanups (old_chain);
4519 /* Create a prototype generic GNU/Linux target. The client can override
4520 it with local methods. */
4523 linux_target_install_ops (struct target_ops *t)
4525 t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint;
4526 t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint;
4527 t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint;
4528 t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint;
4529 t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint;
4530 t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint;
4531 t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint;
4532 t->to_pid_to_exec_file = linux_child_pid_to_exec_file;
4533 t->to_post_startup_inferior = linux_child_post_startup_inferior;
4534 t->to_post_attach = linux_child_post_attach;
4535 t->to_follow_fork = linux_child_follow_fork;
4537 super_xfer_partial = t->to_xfer_partial;
4538 t->to_xfer_partial = linux_xfer_partial;
4540 t->to_static_tracepoint_markers_by_strid
4541 = linux_child_static_tracepoint_markers_by_strid;
4547 struct target_ops *t;
4549 t = inf_ptrace_target ();
4550 linux_target_install_ops (t);
4556 linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int))
4558 struct target_ops *t;
4560 t = inf_ptrace_trad_target (register_u_offset);
4561 linux_target_install_ops (t);
4566 /* target_is_async_p implementation. */
4569 linux_nat_is_async_p (struct target_ops *ops)
4571 return linux_is_async_p ();
4574 /* target_can_async_p implementation. */
4577 linux_nat_can_async_p (struct target_ops *ops)
4579 /* NOTE: palves 2008-03-21: We're only async when the user requests
4580 it explicitly with the "set target-async" command.
4581 Someday, linux will always be async. */
4582 return target_async_permitted;
4586 linux_nat_supports_non_stop (struct target_ops *self)
4591 /* True if we want to support multi-process. To be removed when GDB
4592 supports multi-exec. */
4594 int linux_multi_process = 1;
4597 linux_nat_supports_multi_process (struct target_ops *self)
4599 return linux_multi_process;
4603 linux_nat_supports_disable_randomization (struct target_ops *self)
4605 #ifdef HAVE_PERSONALITY
4612 static int async_terminal_is_ours = 1;
4614 /* target_terminal_inferior implementation.
4616 This is a wrapper around child_terminal_inferior to add async support. */
4619 linux_nat_terminal_inferior (struct target_ops *self)
4621 /* Like target_terminal_inferior, use target_can_async_p, not
4622 target_is_async_p, since at this point the target is not async
4623 yet. If it can async, then we know it will become async prior to
4625 if (!target_can_async_p ())
4627 /* Async mode is disabled. */
4628 child_terminal_inferior (self);
4632 child_terminal_inferior (self);
4634 /* Calls to target_terminal_*() are meant to be idempotent. */
4635 if (!async_terminal_is_ours)
4638 delete_file_handler (input_fd);
4639 async_terminal_is_ours = 0;
4643 /* target_terminal_ours implementation.
4645 This is a wrapper around child_terminal_ours to add async support (and
4646 implement the target_terminal_ours vs target_terminal_ours_for_output
4647 distinction). child_terminal_ours is currently no different than
4648 child_terminal_ours_for_output.
4649 We leave target_terminal_ours_for_output alone, leaving it to
4650 child_terminal_ours_for_output. */
4653 linux_nat_terminal_ours (struct target_ops *self)
4655 /* GDB should never give the terminal to the inferior if the
4656 inferior is running in the background (run&, continue&, etc.),
4657 but claiming it sure should. */
4658 child_terminal_ours (self);
4660 if (async_terminal_is_ours)
4663 clear_sigint_trap ();
4664 add_file_handler (input_fd, stdin_event_handler, 0);
4665 async_terminal_is_ours = 1;
4668 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4669 so we notice when any child changes state, and notify the
4670 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4671 above to wait for the arrival of a SIGCHLD. */
4674 sigchld_handler (int signo)
4676 int old_errno = errno;
4678 if (debug_linux_nat)
4679 ui_file_write_async_safe (gdb_stdlog,
4680 "sigchld\n", sizeof ("sigchld\n") - 1);
4682 if (signo == SIGCHLD
4683 && linux_nat_event_pipe[0] != -1)
4684 async_file_mark (); /* Let the event loop know that there are
4685 events to handle. */
4690 /* Callback registered with the target events file descriptor. */
4693 handle_target_event (int error, gdb_client_data client_data)
4695 inferior_event_handler (INF_REG_EVENT, NULL);
4698 /* Create/destroy the target events pipe. Returns previous state. */
4701 linux_async_pipe (int enable)
4703 int previous = linux_is_async_p ();
4705 if (previous != enable)
4709 /* Block child signals while we create/destroy the pipe, as
4710 their handler writes to it. */
4711 block_child_signals (&prev_mask);
4715 if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1)
4716 internal_error (__FILE__, __LINE__,
4717 "creating event pipe failed.");
4719 fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK);
4720 fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK);
4724 close (linux_nat_event_pipe[0]);
4725 close (linux_nat_event_pipe[1]);
4726 linux_nat_event_pipe[0] = -1;
4727 linux_nat_event_pipe[1] = -1;
4730 restore_child_signals_mask (&prev_mask);
4736 /* target_async implementation. */
4739 linux_nat_async (struct target_ops *ops, int enable)
4743 if (!linux_async_pipe (1))
4745 add_file_handler (linux_nat_event_pipe[0],
4746 handle_target_event, NULL);
4747 /* There may be pending events to handle. Tell the event loop
4754 delete_file_handler (linux_nat_event_pipe[0]);
4755 linux_async_pipe (0);
4760 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4764 linux_nat_stop_lwp (struct lwp_info *lwp, void *data)
4768 if (debug_linux_nat)
4769 fprintf_unfiltered (gdb_stdlog,
4770 "LNSL: running -> suspending %s\n",
4771 target_pid_to_str (lwp->ptid));
4774 if (lwp->last_resume_kind == resume_stop)
4776 if (debug_linux_nat)
4777 fprintf_unfiltered (gdb_stdlog,
4778 "linux-nat: already stopping LWP %ld at "
4780 ptid_get_lwp (lwp->ptid));
4784 stop_callback (lwp, NULL);
4785 lwp->last_resume_kind = resume_stop;
4789 /* Already known to be stopped; do nothing. */
4791 if (debug_linux_nat)
4793 if (find_thread_ptid (lwp->ptid)->stop_requested)
4794 fprintf_unfiltered (gdb_stdlog,
4795 "LNSL: already stopped/stop_requested %s\n",
4796 target_pid_to_str (lwp->ptid));
4798 fprintf_unfiltered (gdb_stdlog,
4799 "LNSL: already stopped/no "
4800 "stop_requested yet %s\n",
4801 target_pid_to_str (lwp->ptid));
4808 linux_nat_stop (struct target_ops *self, ptid_t ptid)
4811 iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL);
4813 linux_ops->to_stop (linux_ops, ptid);
4817 linux_nat_close (struct target_ops *self)
4819 /* Unregister from the event loop. */
4820 if (linux_nat_is_async_p (self))
4821 linux_nat_async (self, 0);
4823 if (linux_ops->to_close)
4824 linux_ops->to_close (linux_ops);
4829 /* When requests are passed down from the linux-nat layer to the
4830 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4831 used. The address space pointer is stored in the inferior object,
4832 but the common code that is passed such ptid can't tell whether
4833 lwpid is a "main" process id or not (it assumes so). We reverse
4834 look up the "main" process id from the lwp here. */
4836 static struct address_space *
4837 linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid)
4839 struct lwp_info *lwp;
4840 struct inferior *inf;
4843 if (ptid_get_lwp (ptid) == 0)
4845 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4847 lwp = find_lwp_pid (ptid);
4848 pid = ptid_get_pid (lwp->ptid);
4852 /* A (pid,lwpid,0) ptid. */
4853 pid = ptid_get_pid (ptid);
4856 inf = find_inferior_pid (pid);
4857 gdb_assert (inf != NULL);
4861 /* Return the cached value of the processor core for thread PTID. */
4864 linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid)
4866 struct lwp_info *info = find_lwp_pid (ptid);
4873 /* Implementation of to_filesystem_is_local. */
4876 linux_nat_filesystem_is_local (struct target_ops *ops)
4878 struct inferior *inf = current_inferior ();
4880 if (inf->fake_pid_p || inf->pid == 0)
4883 return linux_ns_same (inf->pid, LINUX_NS_MNT);
4886 /* Convert the INF argument passed to a to_fileio_* method
4887 to a process ID suitable for passing to its corresponding
4888 linux_mntns_* function. If INF is non-NULL then the
4889 caller is requesting the filesystem seen by INF. If INF
4890 is NULL then the caller is requesting the filesystem seen
4891 by the GDB. We fall back to GDB's filesystem in the case
4892 that INF is non-NULL but its PID is unknown. */
4895 linux_nat_fileio_pid_of (struct inferior *inf)
4897 if (inf == NULL || inf->fake_pid_p || inf->pid == 0)
4903 /* Implementation of to_fileio_open. */
4906 linux_nat_fileio_open (struct target_ops *self,
4907 struct inferior *inf, const char *filename,
4908 int flags, int mode, int *target_errno)
4914 if (fileio_to_host_openflags (flags, &nat_flags) == -1
4915 || fileio_to_host_mode (mode, &nat_mode) == -1)
4917 *target_errno = FILEIO_EINVAL;
4921 fd = linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf),
4922 filename, nat_flags, nat_mode);
4924 *target_errno = host_to_fileio_error (errno);
4929 /* Implementation of to_fileio_readlink. */
4932 linux_nat_fileio_readlink (struct target_ops *self,
4933 struct inferior *inf, const char *filename,
4940 len = linux_mntns_readlink (linux_nat_fileio_pid_of (inf),
4941 filename, buf, sizeof (buf));
4944 *target_errno = host_to_fileio_error (errno);
4948 ret = xmalloc (len + 1);
4949 memcpy (ret, buf, len);
4954 /* Implementation of to_fileio_unlink. */
4957 linux_nat_fileio_unlink (struct target_ops *self,
4958 struct inferior *inf, const char *filename,
4963 ret = linux_mntns_unlink (linux_nat_fileio_pid_of (inf),
4966 *target_errno = host_to_fileio_error (errno);
4972 linux_nat_add_target (struct target_ops *t)
4974 /* Save the provided single-threaded target. We save this in a separate
4975 variable because another target we've inherited from (e.g. inf-ptrace)
4976 may have saved a pointer to T; we want to use it for the final
4977 process stratum target. */
4978 linux_ops_saved = *t;
4979 linux_ops = &linux_ops_saved;
4981 /* Override some methods for multithreading. */
4982 t->to_create_inferior = linux_nat_create_inferior;
4983 t->to_attach = linux_nat_attach;
4984 t->to_detach = linux_nat_detach;
4985 t->to_resume = linux_nat_resume;
4986 t->to_wait = linux_nat_wait;
4987 t->to_pass_signals = linux_nat_pass_signals;
4988 t->to_xfer_partial = linux_nat_xfer_partial;
4989 t->to_kill = linux_nat_kill;
4990 t->to_mourn_inferior = linux_nat_mourn_inferior;
4991 t->to_thread_alive = linux_nat_thread_alive;
4992 t->to_update_thread_list = linux_nat_update_thread_list;
4993 t->to_pid_to_str = linux_nat_pid_to_str;
4994 t->to_thread_name = linux_nat_thread_name;
4995 t->to_has_thread_control = tc_schedlock;
4996 t->to_thread_address_space = linux_nat_thread_address_space;
4997 t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint;
4998 t->to_stopped_data_address = linux_nat_stopped_data_address;
4999 t->to_stopped_by_sw_breakpoint = linux_nat_stopped_by_sw_breakpoint;
5000 t->to_supports_stopped_by_sw_breakpoint = linux_nat_supports_stopped_by_sw_breakpoint;
5001 t->to_stopped_by_hw_breakpoint = linux_nat_stopped_by_hw_breakpoint;
5002 t->to_supports_stopped_by_hw_breakpoint = linux_nat_supports_stopped_by_hw_breakpoint;
5004 t->to_can_async_p = linux_nat_can_async_p;
5005 t->to_is_async_p = linux_nat_is_async_p;
5006 t->to_supports_non_stop = linux_nat_supports_non_stop;
5007 t->to_async = linux_nat_async;
5008 t->to_terminal_inferior = linux_nat_terminal_inferior;
5009 t->to_terminal_ours = linux_nat_terminal_ours;
5011 super_close = t->to_close;
5012 t->to_close = linux_nat_close;
5014 /* Methods for non-stop support. */
5015 t->to_stop = linux_nat_stop;
5017 t->to_supports_multi_process = linux_nat_supports_multi_process;
5019 t->to_supports_disable_randomization
5020 = linux_nat_supports_disable_randomization;
5022 t->to_core_of_thread = linux_nat_core_of_thread;
5024 t->to_filesystem_is_local = linux_nat_filesystem_is_local;
5025 t->to_fileio_open = linux_nat_fileio_open;
5026 t->to_fileio_readlink = linux_nat_fileio_readlink;
5027 t->to_fileio_unlink = linux_nat_fileio_unlink;
5029 /* We don't change the stratum; this target will sit at
5030 process_stratum and thread_db will set at thread_stratum. This
5031 is a little strange, since this is a multi-threaded-capable
5032 target, but we want to be on the stack below thread_db, and we
5033 also want to be used for single-threaded processes. */
5038 /* Register a method to call whenever a new thread is attached. */
5040 linux_nat_set_new_thread (struct target_ops *t,
5041 void (*new_thread) (struct lwp_info *))
5043 /* Save the pointer. We only support a single registered instance
5044 of the GNU/Linux native target, so we do not need to map this to
5046 linux_nat_new_thread = new_thread;
5049 /* See declaration in linux-nat.h. */
5052 linux_nat_set_new_fork (struct target_ops *t,
5053 linux_nat_new_fork_ftype *new_fork)
5055 /* Save the pointer. */
5056 linux_nat_new_fork = new_fork;
5059 /* See declaration in linux-nat.h. */
5062 linux_nat_set_forget_process (struct target_ops *t,
5063 linux_nat_forget_process_ftype *fn)
5065 /* Save the pointer. */
5066 linux_nat_forget_process_hook = fn;
5069 /* See declaration in linux-nat.h. */
5072 linux_nat_forget_process (pid_t pid)
5074 if (linux_nat_forget_process_hook != NULL)
5075 linux_nat_forget_process_hook (pid);
5078 /* Register a method that converts a siginfo object between the layout
5079 that ptrace returns, and the layout in the architecture of the
5082 linux_nat_set_siginfo_fixup (struct target_ops *t,
5083 int (*siginfo_fixup) (siginfo_t *,
5087 /* Save the pointer. */
5088 linux_nat_siginfo_fixup = siginfo_fixup;
5091 /* Register a method to call prior to resuming a thread. */
5094 linux_nat_set_prepare_to_resume (struct target_ops *t,
5095 void (*prepare_to_resume) (struct lwp_info *))
5097 /* Save the pointer. */
5098 linux_nat_prepare_to_resume = prepare_to_resume;
5101 /* See linux-nat.h. */
5104 linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo)
5108 pid = ptid_get_lwp (ptid);
5110 pid = ptid_get_pid (ptid);
5113 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo);
5116 memset (siginfo, 0, sizeof (*siginfo));
5122 /* See nat/linux-nat.h. */
5125 current_lwp_ptid (void)
5127 gdb_assert (ptid_lwp_p (inferior_ptid));
5128 return inferior_ptid;
5131 /* Provide a prototype to silence -Wmissing-prototypes. */
5132 extern initialize_file_ftype _initialize_linux_nat;
5135 _initialize_linux_nat (void)
5137 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance,
5138 &debug_linux_nat, _("\
5139 Set debugging of GNU/Linux lwp module."), _("\
5140 Show debugging of GNU/Linux lwp module."), _("\
5141 Enables printf debugging output."),
5143 show_debug_linux_nat,
5144 &setdebuglist, &showdebuglist);
5146 add_setshow_boolean_cmd ("linux-namespaces", class_maintenance,
5147 &debug_linux_namespaces, _("\
5148 Set debugging of GNU/Linux namespaces module."), _("\
5149 Show debugging of GNU/Linux namespaces module."), _("\
5150 Enables printf debugging output."),
5153 &setdebuglist, &showdebuglist);
5155 /* Save this mask as the default. */
5156 sigprocmask (SIG_SETMASK, NULL, &normal_mask);
5158 /* Install a SIGCHLD handler. */
5159 sigchld_action.sa_handler = sigchld_handler;
5160 sigemptyset (&sigchld_action.sa_mask);
5161 sigchld_action.sa_flags = SA_RESTART;
5163 /* Make it the default. */
5164 sigaction (SIGCHLD, &sigchld_action, NULL);
5166 /* Make sure we don't block SIGCHLD during a sigsuspend. */
5167 sigprocmask (SIG_SETMASK, NULL, &suspend_mask);
5168 sigdelset (&suspend_mask, SIGCHLD);
5170 sigemptyset (&blocked_mask);
5174 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
5175 the GNU/Linux Threads library and therefore doesn't really belong
5178 /* Read variable NAME in the target and return its value if found.
5179 Otherwise return zero. It is assumed that the type of the variable
5183 get_signo (const char *name)
5185 struct bound_minimal_symbol ms;
5188 ms = lookup_minimal_symbol (name, NULL, NULL);
5189 if (ms.minsym == NULL)
5192 if (target_read_memory (BMSYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo,
5193 sizeof (signo)) != 0)
5199 /* Return the set of signals used by the threads library in *SET. */
5202 lin_thread_get_thread_signals (sigset_t *set)
5204 struct sigaction action;
5205 int restart, cancel;
5207 sigemptyset (&blocked_mask);
5210 restart = get_signo ("__pthread_sig_restart");
5211 cancel = get_signo ("__pthread_sig_cancel");
5213 /* LinuxThreads normally uses the first two RT signals, but in some legacy
5214 cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
5215 not provide any way for the debugger to query the signal numbers -
5216 fortunately they don't change! */
5219 restart = __SIGRTMIN;
5222 cancel = __SIGRTMIN + 1;
5224 sigaddset (set, restart);
5225 sigaddset (set, cancel);
5227 /* The GNU/Linux Threads library makes terminating threads send a
5228 special "cancel" signal instead of SIGCHLD. Make sure we catch
5229 those (to prevent them from terminating GDB itself, which is
5230 likely to be their default action) and treat them the same way as
5233 action.sa_handler = sigchld_handler;
5234 sigemptyset (&action.sa_mask);
5235 action.sa_flags = SA_RESTART;
5236 sigaction (cancel, &action, NULL);
5238 /* We block the "cancel" signal throughout this code ... */
5239 sigaddset (&blocked_mask, cancel);
5240 sigprocmask (SIG_BLOCK, &blocked_mask, NULL);
5242 /* ... except during a sigsuspend. */
5243 sigdelset (&suspend_mask, cancel);