1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
4 2011 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "gdb_string.h"
26 #include "gdb_assert.h"
27 #ifdef HAVE_TKILL_SYSCALL
29 #include <sys/syscall.h>
31 #include <sys/ptrace.h>
32 #include "linux-nat.h"
33 #include "linux-ptrace.h"
34 #include "linux-fork.h"
35 #include "gdbthread.h"
39 #include "inf-ptrace.h"
41 #include <sys/param.h> /* for MAXPATHLEN */
42 #include <sys/procfs.h> /* for elf_gregset etc. */
43 #include "elf-bfd.h" /* for elfcore_write_* */
44 #include "gregset.h" /* for gregset */
45 #include "gdbcore.h" /* for get_exec_file */
46 #include <ctype.h> /* for isdigit */
47 #include "gdbthread.h" /* for struct thread_info etc. */
48 #include "gdb_stat.h" /* for struct stat */
49 #include <fcntl.h> /* for O_RDONLY */
51 #include "event-loop.h"
52 #include "event-top.h"
54 #include <sys/types.h>
55 #include "gdb_dirent.h"
56 #include "xml-support.h"
60 #include "linux-osdata.h"
63 #define SPUFS_MAGIC 0x23c9b64e
66 #ifdef HAVE_PERSONALITY
67 # include <sys/personality.h>
68 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
69 # define ADDR_NO_RANDOMIZE 0x0040000
71 #endif /* HAVE_PERSONALITY */
73 /* This comment documents high-level logic of this file.
75 Waiting for events in sync mode
76 ===============================
78 When waiting for an event in a specific thread, we just use waitpid, passing
79 the specific pid, and not passing WNOHANG.
81 When waiting for an event in all threads, waitpid is not quite good. Prior to
82 version 2.4, Linux can either wait for event in main thread, or in secondary
83 threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might
84 miss an event. The solution is to use non-blocking waitpid, together with
85 sigsuspend. First, we use non-blocking waitpid to get an event in the main
86 process, if any. Second, we use non-blocking waitpid with the __WCLONED
87 flag to check for events in cloned processes. If nothing is found, we use
88 sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something
89 happened to a child process -- and SIGCHLD will be delivered both for events
90 in main debugged process and in cloned processes. As soon as we know there's
91 an event, we get back to calling nonblocking waitpid with and without
94 Note that SIGCHLD should be blocked between waitpid and sigsuspend calls,
95 so that we don't miss a signal. If SIGCHLD arrives in between, when it's
96 blocked, the signal becomes pending and sigsuspend immediately
97 notices it and returns.
99 Waiting for events in async mode
100 ================================
102 In async mode, GDB should always be ready to handle both user input
103 and target events, so neither blocking waitpid nor sigsuspend are
104 viable options. Instead, we should asynchronously notify the GDB main
105 event loop whenever there's an unprocessed event from the target. We
106 detect asynchronous target events by handling SIGCHLD signals. To
107 notify the event loop about target events, the self-pipe trick is used
108 --- a pipe is registered as waitable event source in the event loop,
109 the event loop select/poll's on the read end of this pipe (as well on
110 other event sources, e.g., stdin), and the SIGCHLD handler writes a
111 byte to this pipe. This is more portable than relying on
112 pselect/ppoll, since on kernels that lack those syscalls, libc
113 emulates them with select/poll+sigprocmask, and that is racy
114 (a.k.a. plain broken).
116 Obviously, if we fail to notify the event loop if there's a target
117 event, it's bad. OTOH, if we notify the event loop when there's no
118 event from the target, linux_nat_wait will detect that there's no real
119 event to report, and return event of type TARGET_WAITKIND_IGNORE.
120 This is mostly harmless, but it will waste time and is better avoided.
122 The main design point is that every time GDB is outside linux-nat.c,
123 we have a SIGCHLD handler installed that is called when something
124 happens to the target and notifies the GDB event loop. Whenever GDB
125 core decides to handle the event, and calls into linux-nat.c, we
126 process things as in sync mode, except that the we never block in
129 While processing an event, we may end up momentarily blocked in
130 waitpid calls. Those waitpid calls, while blocking, are guarantied to
131 return quickly. E.g., in all-stop mode, before reporting to the core
132 that an LWP hit a breakpoint, all LWPs are stopped by sending them
133 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
134 Note that this is different from blocking indefinitely waiting for the
135 next event --- here, we're already handling an event.
140 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
141 signal is not entirely significant; we just need for a signal to be delivered,
142 so that we can intercept it. SIGSTOP's advantage is that it can not be
143 blocked. A disadvantage is that it is not a real-time signal, so it can only
144 be queued once; we do not keep track of other sources of SIGSTOP.
146 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
147 use them, because they have special behavior when the signal is generated -
148 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
149 kills the entire thread group.
151 A delivered SIGSTOP would stop the entire thread group, not just the thread we
152 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
153 cancel it (by PTRACE_CONT without passing SIGSTOP).
155 We could use a real-time signal instead. This would solve those problems; we
156 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
157 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
158 generates it, and there are races with trying to find a signal that is not
162 #define O_LARGEFILE 0
165 /* Unlike other extended result codes, WSTOPSIG (status) on
166 PTRACE_O_TRACESYSGOOD syscall events doesn't return SIGTRAP, but
167 instead SIGTRAP with bit 7 set. */
168 #define SYSCALL_SIGTRAP (SIGTRAP | 0x80)
170 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
171 the use of the multi-threaded target. */
172 static struct target_ops *linux_ops;
173 static struct target_ops linux_ops_saved;
175 /* The method to call, if any, when a new thread is attached. */
176 static void (*linux_nat_new_thread) (ptid_t);
178 /* The method to call, if any, when the siginfo object needs to be
179 converted between the layout returned by ptrace, and the layout in
180 the architecture of the inferior. */
181 static int (*linux_nat_siginfo_fixup) (struct siginfo *,
185 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
186 Called by our to_xfer_partial. */
187 static LONGEST (*super_xfer_partial) (struct target_ops *,
189 const char *, gdb_byte *,
193 static int debug_linux_nat;
195 show_debug_linux_nat (struct ui_file *file, int from_tty,
196 struct cmd_list_element *c, const char *value)
198 fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"),
202 static int disable_randomization = 1;
205 show_disable_randomization (struct ui_file *file, int from_tty,
206 struct cmd_list_element *c, const char *value)
208 #ifdef HAVE_PERSONALITY
209 fprintf_filtered (file,
210 _("Disabling randomization of debuggee's "
211 "virtual address space is %s.\n"),
213 #else /* !HAVE_PERSONALITY */
214 fputs_filtered (_("Disabling randomization of debuggee's "
215 "virtual address space is unsupported on\n"
216 "this platform.\n"), file);
217 #endif /* !HAVE_PERSONALITY */
221 set_disable_randomization (char *args, int from_tty,
222 struct cmd_list_element *c)
224 #ifndef HAVE_PERSONALITY
225 error (_("Disabling randomization of debuggee's "
226 "virtual address space is unsupported on\n"
228 #endif /* !HAVE_PERSONALITY */
231 struct simple_pid_list
235 struct simple_pid_list *next;
237 struct simple_pid_list *stopped_pids;
239 /* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACEFORK
240 can not be used, 1 if it can. */
242 static int linux_supports_tracefork_flag = -1;
244 /* This variable is a tri-state flag: -1 for unknown, 0 if
245 PTRACE_O_TRACESYSGOOD can not be used, 1 if it can. */
247 static int linux_supports_tracesysgood_flag = -1;
249 /* If we have PTRACE_O_TRACEFORK, this flag indicates whether we also have
250 PTRACE_O_TRACEVFORKDONE. */
252 static int linux_supports_tracevforkdone_flag = -1;
254 /* Stores the current used ptrace() options. */
255 static int current_ptrace_options = 0;
257 /* Async mode support. */
259 /* The read/write ends of the pipe registered as waitable file in the
261 static int linux_nat_event_pipe[2] = { -1, -1 };
263 /* Flush the event pipe. */
266 async_file_flush (void)
273 ret = read (linux_nat_event_pipe[0], &buf, 1);
275 while (ret >= 0 || (ret == -1 && errno == EINTR));
278 /* Put something (anything, doesn't matter what, or how much) in event
279 pipe, so that the select/poll in the event-loop realizes we have
280 something to process. */
283 async_file_mark (void)
287 /* It doesn't really matter what the pipe contains, as long we end
288 up with something in it. Might as well flush the previous
294 ret = write (linux_nat_event_pipe[1], "+", 1);
296 while (ret == -1 && errno == EINTR);
298 /* Ignore EAGAIN. If the pipe is full, the event loop will already
299 be awakened anyway. */
302 static void linux_nat_async (void (*callback)
303 (enum inferior_event_type event_type,
306 static int kill_lwp (int lwpid, int signo);
308 static int stop_callback (struct lwp_info *lp, void *data);
310 static void block_child_signals (sigset_t *prev_mask);
311 static void restore_child_signals_mask (sigset_t *prev_mask);
314 static struct lwp_info *add_lwp (ptid_t ptid);
315 static void purge_lwp_list (int pid);
316 static struct lwp_info *find_lwp_pid (ptid_t ptid);
319 /* Trivial list manipulation functions to keep track of a list of
320 new stopped processes. */
322 add_to_pid_list (struct simple_pid_list **listp, int pid, int status)
324 struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list));
327 new_pid->status = status;
328 new_pid->next = *listp;
333 pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp)
335 struct simple_pid_list **p;
337 for (p = listp; *p != NULL; p = &(*p)->next)
338 if ((*p)->pid == pid)
340 struct simple_pid_list *next = (*p)->next;
342 *statusp = (*p)->status;
351 linux_record_stopped_pid (int pid, int status)
353 add_to_pid_list (&stopped_pids, pid, status);
357 /* A helper function for linux_test_for_tracefork, called after fork (). */
360 linux_tracefork_child (void)
362 ptrace (PTRACE_TRACEME, 0, 0, 0);
363 kill (getpid (), SIGSTOP);
368 /* Wrapper function for waitpid which handles EINTR. */
371 my_waitpid (int pid, int *statusp, int flags)
377 ret = waitpid (pid, statusp, flags);
379 while (ret == -1 && errno == EINTR);
384 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events.
386 First, we try to enable fork tracing on ORIGINAL_PID. If this fails,
387 we know that the feature is not available. This may change the tracing
388 options for ORIGINAL_PID, but we'll be setting them shortly anyway.
390 However, if it succeeds, we don't know for sure that the feature is
391 available; old versions of PTRACE_SETOPTIONS ignored unknown options. We
392 create a child process, attach to it, use PTRACE_SETOPTIONS to enable
393 fork tracing, and let it fork. If the process exits, we assume that we
394 can't use TRACEFORK; if we get the fork notification, and we can extract
395 the new child's PID, then we assume that we can. */
398 linux_test_for_tracefork (int original_pid)
400 int child_pid, ret, status;
404 /* We don't want those ptrace calls to be interrupted. */
405 block_child_signals (&prev_mask);
407 linux_supports_tracefork_flag = 0;
408 linux_supports_tracevforkdone_flag = 0;
410 ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACEFORK);
413 restore_child_signals_mask (&prev_mask);
419 perror_with_name (("fork"));
422 linux_tracefork_child ();
424 ret = my_waitpid (child_pid, &status, 0);
426 perror_with_name (("waitpid"));
427 else if (ret != child_pid)
428 error (_("linux_test_for_tracefork: waitpid: unexpected result %d."), ret);
429 if (! WIFSTOPPED (status))
430 error (_("linux_test_for_tracefork: waitpid: unexpected status %d."),
433 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK);
436 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
439 warning (_("linux_test_for_tracefork: failed to kill child"));
440 restore_child_signals_mask (&prev_mask);
444 ret = my_waitpid (child_pid, &status, 0);
445 if (ret != child_pid)
446 warning (_("linux_test_for_tracefork: failed "
447 "to wait for killed child"));
448 else if (!WIFSIGNALED (status))
449 warning (_("linux_test_for_tracefork: unexpected "
450 "wait status 0x%x from killed child"), status);
452 restore_child_signals_mask (&prev_mask);
456 /* Check whether PTRACE_O_TRACEVFORKDONE is available. */
457 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0,
458 PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORKDONE);
459 linux_supports_tracevforkdone_flag = (ret == 0);
461 ret = ptrace (PTRACE_CONT, child_pid, 0, 0);
463 warning (_("linux_test_for_tracefork: failed to resume child"));
465 ret = my_waitpid (child_pid, &status, 0);
467 if (ret == child_pid && WIFSTOPPED (status)
468 && status >> 16 == PTRACE_EVENT_FORK)
471 ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
472 if (ret == 0 && second_pid != 0)
476 linux_supports_tracefork_flag = 1;
477 my_waitpid (second_pid, &second_status, 0);
478 ret = ptrace (PTRACE_KILL, second_pid, 0, 0);
480 warning (_("linux_test_for_tracefork: "
481 "failed to kill second child"));
482 my_waitpid (second_pid, &status, 0);
486 warning (_("linux_test_for_tracefork: unexpected result from waitpid "
487 "(%d, status 0x%x)"), ret, status);
489 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
491 warning (_("linux_test_for_tracefork: failed to kill child"));
492 my_waitpid (child_pid, &status, 0);
494 restore_child_signals_mask (&prev_mask);
497 /* Determine if PTRACE_O_TRACESYSGOOD can be used to follow syscalls.
499 We try to enable syscall tracing on ORIGINAL_PID. If this fails,
500 we know that the feature is not available. This may change the tracing
501 options for ORIGINAL_PID, but we'll be setting them shortly anyway. */
504 linux_test_for_tracesysgood (int original_pid)
509 /* We don't want those ptrace calls to be interrupted. */
510 block_child_signals (&prev_mask);
512 linux_supports_tracesysgood_flag = 0;
514 ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACESYSGOOD);
518 linux_supports_tracesysgood_flag = 1;
520 restore_child_signals_mask (&prev_mask);
523 /* Determine wether we support PTRACE_O_TRACESYSGOOD option available.
524 This function also sets linux_supports_tracesysgood_flag. */
527 linux_supports_tracesysgood (int pid)
529 if (linux_supports_tracesysgood_flag == -1)
530 linux_test_for_tracesysgood (pid);
531 return linux_supports_tracesysgood_flag;
534 /* Return non-zero iff we have tracefork functionality available.
535 This function also sets linux_supports_tracefork_flag. */
538 linux_supports_tracefork (int pid)
540 if (linux_supports_tracefork_flag == -1)
541 linux_test_for_tracefork (pid);
542 return linux_supports_tracefork_flag;
546 linux_supports_tracevforkdone (int pid)
548 if (linux_supports_tracefork_flag == -1)
549 linux_test_for_tracefork (pid);
550 return linux_supports_tracevforkdone_flag;
554 linux_enable_tracesysgood (ptid_t ptid)
556 int pid = ptid_get_lwp (ptid);
559 pid = ptid_get_pid (ptid);
561 if (linux_supports_tracesysgood (pid) == 0)
564 current_ptrace_options |= PTRACE_O_TRACESYSGOOD;
566 ptrace (PTRACE_SETOPTIONS, pid, 0, current_ptrace_options);
571 linux_enable_event_reporting (ptid_t ptid)
573 int pid = ptid_get_lwp (ptid);
576 pid = ptid_get_pid (ptid);
578 if (! linux_supports_tracefork (pid))
581 current_ptrace_options |= PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK
582 | PTRACE_O_TRACEEXEC | PTRACE_O_TRACECLONE;
584 if (linux_supports_tracevforkdone (pid))
585 current_ptrace_options |= PTRACE_O_TRACEVFORKDONE;
587 /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support
588 read-only process state. */
590 ptrace (PTRACE_SETOPTIONS, pid, 0, current_ptrace_options);
594 linux_child_post_attach (int pid)
596 linux_enable_event_reporting (pid_to_ptid (pid));
597 check_for_thread_db ();
598 linux_enable_tracesysgood (pid_to_ptid (pid));
602 linux_child_post_startup_inferior (ptid_t ptid)
604 linux_enable_event_reporting (ptid);
605 check_for_thread_db ();
606 linux_enable_tracesysgood (ptid);
610 linux_child_follow_fork (struct target_ops *ops, int follow_child)
614 int parent_pid, child_pid;
616 block_child_signals (&prev_mask);
618 has_vforked = (inferior_thread ()->pending_follow.kind
619 == TARGET_WAITKIND_VFORKED);
620 parent_pid = ptid_get_lwp (inferior_ptid);
622 parent_pid = ptid_get_pid (inferior_ptid);
623 child_pid = PIDGET (inferior_thread ()->pending_follow.value.related_pid);
626 linux_enable_event_reporting (pid_to_ptid (child_pid));
629 && !non_stop /* Non-stop always resumes both branches. */
630 && (!target_is_async_p () || sync_execution)
631 && !(follow_child || detach_fork || sched_multi))
633 /* The parent stays blocked inside the vfork syscall until the
634 child execs or exits. If we don't let the child run, then
635 the parent stays blocked. If we're telling the parent to run
636 in the foreground, the user will not be able to ctrl-c to get
637 back the terminal, effectively hanging the debug session. */
638 fprintf_filtered (gdb_stderr, _("\
639 Can not resume the parent process over vfork in the foreground while\n\
640 holding the child stopped. Try \"set detach-on-fork\" or \
641 \"set schedule-multiple\".\n"));
642 /* FIXME output string > 80 columns. */
648 struct lwp_info *child_lp = NULL;
650 /* We're already attached to the parent, by default. */
652 /* Detach new forked process? */
655 /* Before detaching from the child, remove all breakpoints
656 from it. If we forked, then this has already been taken
657 care of by infrun.c. If we vforked however, any
658 breakpoint inserted in the parent is visible in the
659 child, even those added while stopped in a vfork
660 catchpoint. This will remove the breakpoints from the
661 parent also, but they'll be reinserted below. */
664 /* keep breakpoints list in sync. */
665 remove_breakpoints_pid (GET_PID (inferior_ptid));
668 if (info_verbose || debug_linux_nat)
670 target_terminal_ours ();
671 fprintf_filtered (gdb_stdlog,
672 "Detaching after fork from "
673 "child process %d.\n",
677 ptrace (PTRACE_DETACH, child_pid, 0, 0);
681 struct inferior *parent_inf, *child_inf;
682 struct cleanup *old_chain;
684 /* Add process to GDB's tables. */
685 child_inf = add_inferior (child_pid);
687 parent_inf = current_inferior ();
688 child_inf->attach_flag = parent_inf->attach_flag;
689 copy_terminal_info (child_inf, parent_inf);
691 old_chain = save_inferior_ptid ();
692 save_current_program_space ();
694 inferior_ptid = ptid_build (child_pid, child_pid, 0);
695 add_thread (inferior_ptid);
696 child_lp = add_lwp (inferior_ptid);
697 child_lp->stopped = 1;
698 child_lp->resumed = 1;
700 /* If this is a vfork child, then the address-space is
701 shared with the parent. */
704 child_inf->pspace = parent_inf->pspace;
705 child_inf->aspace = parent_inf->aspace;
707 /* The parent will be frozen until the child is done
708 with the shared region. Keep track of the
710 child_inf->vfork_parent = parent_inf;
711 child_inf->pending_detach = 0;
712 parent_inf->vfork_child = child_inf;
713 parent_inf->pending_detach = 0;
717 child_inf->aspace = new_address_space ();
718 child_inf->pspace = add_program_space (child_inf->aspace);
719 child_inf->removable = 1;
720 set_current_program_space (child_inf->pspace);
721 clone_program_space (child_inf->pspace, parent_inf->pspace);
723 /* Let the shared library layer (solib-svr4) learn about
724 this new process, relocate the cloned exec, pull in
725 shared libraries, and install the solib event
726 breakpoint. If a "cloned-VM" event was propagated
727 better throughout the core, this wouldn't be
729 solib_create_inferior_hook (0);
732 /* Let the thread_db layer learn about this new process. */
733 check_for_thread_db ();
735 do_cleanups (old_chain);
741 struct inferior *parent_inf;
743 parent_inf = current_inferior ();
745 /* If we detached from the child, then we have to be careful
746 to not insert breakpoints in the parent until the child
747 is done with the shared memory region. However, if we're
748 staying attached to the child, then we can and should
749 insert breakpoints, so that we can debug it. A
750 subsequent child exec or exit is enough to know when does
751 the child stops using the parent's address space. */
752 parent_inf->waiting_for_vfork_done = detach_fork;
753 parent_inf->pspace->breakpoints_not_allowed = detach_fork;
755 lp = find_lwp_pid (pid_to_ptid (parent_pid));
756 gdb_assert (linux_supports_tracefork_flag >= 0);
757 if (linux_supports_tracevforkdone (0))
760 fprintf_unfiltered (gdb_stdlog,
761 "LCFF: waiting for VFORK_DONE on %d\n",
767 /* We'll handle the VFORK_DONE event like any other
768 event, in target_wait. */
772 /* We can't insert breakpoints until the child has
773 finished with the shared memory region. We need to
774 wait until that happens. Ideal would be to just
776 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
777 - waitpid (parent_pid, &status, __WALL);
778 However, most architectures can't handle a syscall
779 being traced on the way out if it wasn't traced on
782 We might also think to loop, continuing the child
783 until it exits or gets a SIGTRAP. One problem is
784 that the child might call ptrace with PTRACE_TRACEME.
786 There's no simple and reliable way to figure out when
787 the vforked child will be done with its copy of the
788 shared memory. We could step it out of the syscall,
789 two instructions, let it go, and then single-step the
790 parent once. When we have hardware single-step, this
791 would work; with software single-step it could still
792 be made to work but we'd have to be able to insert
793 single-step breakpoints in the child, and we'd have
794 to insert -just- the single-step breakpoint in the
795 parent. Very awkward.
797 In the end, the best we can do is to make sure it
798 runs for a little while. Hopefully it will be out of
799 range of any breakpoints we reinsert. Usually this
800 is only the single-step breakpoint at vfork's return
804 fprintf_unfiltered (gdb_stdlog,
805 "LCFF: no VFORK_DONE "
806 "support, sleeping a bit\n");
810 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
811 and leave it pending. The next linux_nat_resume call
812 will notice a pending event, and bypasses actually
813 resuming the inferior. */
815 lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE;
819 /* If we're in async mode, need to tell the event loop
820 there's something here to process. */
821 if (target_can_async_p ())
828 struct inferior *parent_inf, *child_inf;
830 struct program_space *parent_pspace;
832 if (info_verbose || debug_linux_nat)
834 target_terminal_ours ();
836 fprintf_filtered (gdb_stdlog,
837 _("Attaching after process %d "
838 "vfork to child process %d.\n"),
839 parent_pid, child_pid);
841 fprintf_filtered (gdb_stdlog,
842 _("Attaching after process %d "
843 "fork to child process %d.\n"),
844 parent_pid, child_pid);
847 /* Add the new inferior first, so that the target_detach below
848 doesn't unpush the target. */
850 child_inf = add_inferior (child_pid);
852 parent_inf = current_inferior ();
853 child_inf->attach_flag = parent_inf->attach_flag;
854 copy_terminal_info (child_inf, parent_inf);
856 parent_pspace = parent_inf->pspace;
858 /* If we're vforking, we want to hold on to the parent until the
859 child exits or execs. At child exec or exit time we can
860 remove the old breakpoints from the parent and detach or
861 resume debugging it. Otherwise, detach the parent now; we'll
862 want to reuse it's program/address spaces, but we can't set
863 them to the child before removing breakpoints from the
864 parent, otherwise, the breakpoints module could decide to
865 remove breakpoints from the wrong process (since they'd be
866 assigned to the same address space). */
870 gdb_assert (child_inf->vfork_parent == NULL);
871 gdb_assert (parent_inf->vfork_child == NULL);
872 child_inf->vfork_parent = parent_inf;
873 child_inf->pending_detach = 0;
874 parent_inf->vfork_child = child_inf;
875 parent_inf->pending_detach = detach_fork;
876 parent_inf->waiting_for_vfork_done = 0;
878 else if (detach_fork)
879 target_detach (NULL, 0);
881 /* Note that the detach above makes PARENT_INF dangling. */
883 /* Add the child thread to the appropriate lists, and switch to
884 this new thread, before cloning the program space, and
885 informing the solib layer about this new process. */
887 inferior_ptid = ptid_build (child_pid, child_pid, 0);
888 add_thread (inferior_ptid);
889 lp = add_lwp (inferior_ptid);
893 /* If this is a vfork child, then the address-space is shared
894 with the parent. If we detached from the parent, then we can
895 reuse the parent's program/address spaces. */
896 if (has_vforked || detach_fork)
898 child_inf->pspace = parent_pspace;
899 child_inf->aspace = child_inf->pspace->aspace;
903 child_inf->aspace = new_address_space ();
904 child_inf->pspace = add_program_space (child_inf->aspace);
905 child_inf->removable = 1;
906 set_current_program_space (child_inf->pspace);
907 clone_program_space (child_inf->pspace, parent_pspace);
909 /* Let the shared library layer (solib-svr4) learn about
910 this new process, relocate the cloned exec, pull in
911 shared libraries, and install the solib event breakpoint.
912 If a "cloned-VM" event was propagated better throughout
913 the core, this wouldn't be required. */
914 solib_create_inferior_hook (0);
917 /* Let the thread_db layer learn about this new process. */
918 check_for_thread_db ();
921 restore_child_signals_mask (&prev_mask);
927 linux_child_insert_fork_catchpoint (int pid)
929 return !linux_supports_tracefork (pid);
933 linux_child_remove_fork_catchpoint (int pid)
939 linux_child_insert_vfork_catchpoint (int pid)
941 return !linux_supports_tracefork (pid);
945 linux_child_remove_vfork_catchpoint (int pid)
951 linux_child_insert_exec_catchpoint (int pid)
953 return !linux_supports_tracefork (pid);
957 linux_child_remove_exec_catchpoint (int pid)
963 linux_child_set_syscall_catchpoint (int pid, int needed, int any_count,
964 int table_size, int *table)
966 if (!linux_supports_tracesysgood (pid))
969 /* On GNU/Linux, we ignore the arguments. It means that we only
970 enable the syscall catchpoints, but do not disable them.
972 Also, we do not use the `table' information because we do not
973 filter system calls here. We let GDB do the logic for us. */
977 /* On GNU/Linux there are no real LWP's. The closest thing to LWP's
978 are processes sharing the same VM space. A multi-threaded process
979 is basically a group of such processes. However, such a grouping
980 is almost entirely a user-space issue; the kernel doesn't enforce
981 such a grouping at all (this might change in the future). In
982 general, we'll rely on the threads library (i.e. the GNU/Linux
983 Threads library) to provide such a grouping.
985 It is perfectly well possible to write a multi-threaded application
986 without the assistance of a threads library, by using the clone
987 system call directly. This module should be able to give some
988 rudimentary support for debugging such applications if developers
989 specify the CLONE_PTRACE flag in the clone system call, and are
990 using the Linux kernel 2.4 or above.
992 Note that there are some peculiarities in GNU/Linux that affect
995 - In general one should specify the __WCLONE flag to waitpid in
996 order to make it report events for any of the cloned processes
997 (and leave it out for the initial process). However, if a cloned
998 process has exited the exit status is only reported if the
999 __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
1000 we cannot use it since GDB must work on older systems too.
1002 - When a traced, cloned process exits and is waited for by the
1003 debugger, the kernel reassigns it to the original parent and
1004 keeps it around as a "zombie". Somehow, the GNU/Linux Threads
1005 library doesn't notice this, which leads to the "zombie problem":
1006 When debugged a multi-threaded process that spawns a lot of
1007 threads will run out of processes, even if the threads exit,
1008 because the "zombies" stay around. */
1010 /* List of known LWPs. */
1011 struct lwp_info *lwp_list;
1014 /* Original signal mask. */
1015 static sigset_t normal_mask;
1017 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
1018 _initialize_linux_nat. */
1019 static sigset_t suspend_mask;
1021 /* Signals to block to make that sigsuspend work. */
1022 static sigset_t blocked_mask;
1024 /* SIGCHLD action. */
1025 struct sigaction sigchld_action;
1027 /* Block child signals (SIGCHLD and linux threads signals), and store
1028 the previous mask in PREV_MASK. */
1031 block_child_signals (sigset_t *prev_mask)
1033 /* Make sure SIGCHLD is blocked. */
1034 if (!sigismember (&blocked_mask, SIGCHLD))
1035 sigaddset (&blocked_mask, SIGCHLD);
1037 sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask);
1040 /* Restore child signals mask, previously returned by
1041 block_child_signals. */
1044 restore_child_signals_mask (sigset_t *prev_mask)
1046 sigprocmask (SIG_SETMASK, prev_mask, NULL);
1049 /* Mask of signals to pass directly to the inferior. */
1050 static sigset_t pass_mask;
1052 /* Update signals to pass to the inferior. */
1054 linux_nat_pass_signals (int numsigs, unsigned char *pass_signals)
1058 sigemptyset (&pass_mask);
1060 for (signo = 1; signo < NSIG; signo++)
1062 int target_signo = target_signal_from_host (signo);
1063 if (target_signo < numsigs && pass_signals[target_signo])
1064 sigaddset (&pass_mask, signo);
1070 /* Prototypes for local functions. */
1071 static int stop_wait_callback (struct lwp_info *lp, void *data);
1072 static int linux_thread_alive (ptid_t ptid);
1073 static char *linux_child_pid_to_exec_file (int pid);
1076 /* Convert wait status STATUS to a string. Used for printing debug
1080 status_to_str (int status)
1082 static char buf[64];
1084 if (WIFSTOPPED (status))
1086 if (WSTOPSIG (status) == SYSCALL_SIGTRAP)
1087 snprintf (buf, sizeof (buf), "%s (stopped at syscall)",
1088 strsignal (SIGTRAP));
1090 snprintf (buf, sizeof (buf), "%s (stopped)",
1091 strsignal (WSTOPSIG (status)));
1093 else if (WIFSIGNALED (status))
1094 snprintf (buf, sizeof (buf), "%s (terminated)",
1095 strsignal (WTERMSIG (status)));
1097 snprintf (buf, sizeof (buf), "%d (exited)", WEXITSTATUS (status));
1102 /* Remove all LWPs belong to PID from the lwp list. */
1105 purge_lwp_list (int pid)
1107 struct lwp_info *lp, *lpprev, *lpnext;
1111 for (lp = lwp_list; lp; lp = lpnext)
1115 if (ptid_get_pid (lp->ptid) == pid)
1118 lwp_list = lp->next;
1120 lpprev->next = lp->next;
1129 /* Return the number of known LWPs in the tgid given by PID. */
1135 struct lwp_info *lp;
1137 for (lp = lwp_list; lp; lp = lp->next)
1138 if (ptid_get_pid (lp->ptid) == pid)
1144 /* Add the LWP specified by PID to the list. Return a pointer to the
1145 structure describing the new LWP. The LWP should already be stopped
1146 (with an exception for the very first LWP). */
1148 static struct lwp_info *
1149 add_lwp (ptid_t ptid)
1151 struct lwp_info *lp;
1153 gdb_assert (is_lwp (ptid));
1155 lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info));
1157 memset (lp, 0, sizeof (struct lwp_info));
1159 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
1164 lp->next = lwp_list;
1167 if (num_lwps (GET_PID (ptid)) > 1 && linux_nat_new_thread != NULL)
1168 linux_nat_new_thread (ptid);
1173 /* Remove the LWP specified by PID from the list. */
1176 delete_lwp (ptid_t ptid)
1178 struct lwp_info *lp, *lpprev;
1182 for (lp = lwp_list; lp; lpprev = lp, lp = lp->next)
1183 if (ptid_equal (lp->ptid, ptid))
1190 lpprev->next = lp->next;
1192 lwp_list = lp->next;
1197 /* Return a pointer to the structure describing the LWP corresponding
1198 to PID. If no corresponding LWP could be found, return NULL. */
1200 static struct lwp_info *
1201 find_lwp_pid (ptid_t ptid)
1203 struct lwp_info *lp;
1207 lwp = GET_LWP (ptid);
1209 lwp = GET_PID (ptid);
1211 for (lp = lwp_list; lp; lp = lp->next)
1212 if (lwp == GET_LWP (lp->ptid))
1218 /* Call CALLBACK with its second argument set to DATA for every LWP in
1219 the list. If CALLBACK returns 1 for a particular LWP, return a
1220 pointer to the structure describing that LWP immediately.
1221 Otherwise return NULL. */
1224 iterate_over_lwps (ptid_t filter,
1225 int (*callback) (struct lwp_info *, void *),
1228 struct lwp_info *lp, *lpnext;
1230 for (lp = lwp_list; lp; lp = lpnext)
1234 if (ptid_match (lp->ptid, filter))
1236 if ((*callback) (lp, data))
1244 /* Update our internal state when changing from one checkpoint to
1245 another indicated by NEW_PTID. We can only switch single-threaded
1246 applications, so we only create one new LWP, and the previous list
1250 linux_nat_switch_fork (ptid_t new_ptid)
1252 struct lwp_info *lp;
1254 purge_lwp_list (GET_PID (inferior_ptid));
1256 lp = add_lwp (new_ptid);
1259 /* This changes the thread's ptid while preserving the gdb thread
1260 num. Also changes the inferior pid, while preserving the
1262 thread_change_ptid (inferior_ptid, new_ptid);
1264 /* We've just told GDB core that the thread changed target id, but,
1265 in fact, it really is a different thread, with different register
1267 registers_changed ();
1270 /* Handle the exit of a single thread LP. */
1273 exit_lwp (struct lwp_info *lp)
1275 struct thread_info *th = find_thread_ptid (lp->ptid);
1279 if (print_thread_events)
1280 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid));
1282 delete_thread (lp->ptid);
1285 delete_lwp (lp->ptid);
1288 /* Return an lwp's tgid, found in `/proc/PID/status'. */
1291 linux_proc_get_tgid (int lwpid)
1297 snprintf (buf, sizeof (buf), "/proc/%d/status", (int) lwpid);
1298 status_file = fopen (buf, "r");
1299 if (status_file != NULL)
1301 while (fgets (buf, sizeof (buf), status_file))
1303 if (strncmp (buf, "Tgid:", 5) == 0)
1305 tgid = strtoul (buf + strlen ("Tgid:"), NULL, 10);
1310 fclose (status_file);
1316 /* Detect `T (stopped)' in `/proc/PID/status'.
1317 Other states including `T (tracing stop)' are reported as false. */
1320 pid_is_stopped (pid_t pid)
1326 snprintf (buf, sizeof (buf), "/proc/%d/status", (int) pid);
1327 status_file = fopen (buf, "r");
1328 if (status_file != NULL)
1332 while (fgets (buf, sizeof (buf), status_file))
1334 if (strncmp (buf, "State:", 6) == 0)
1340 if (have_state && strstr (buf, "T (stopped)") != NULL)
1342 fclose (status_file);
1347 /* Wait for the LWP specified by LP, which we have just attached to.
1348 Returns a wait status for that LWP, to cache. */
1351 linux_nat_post_attach_wait (ptid_t ptid, int first, int *cloned,
1354 pid_t new_pid, pid = GET_LWP (ptid);
1357 if (pid_is_stopped (pid))
1359 if (debug_linux_nat)
1360 fprintf_unfiltered (gdb_stdlog,
1361 "LNPAW: Attaching to a stopped process\n");
1363 /* The process is definitely stopped. It is in a job control
1364 stop, unless the kernel predates the TASK_STOPPED /
1365 TASK_TRACED distinction, in which case it might be in a
1366 ptrace stop. Make sure it is in a ptrace stop; from there we
1367 can kill it, signal it, et cetera.
1369 First make sure there is a pending SIGSTOP. Since we are
1370 already attached, the process can not transition from stopped
1371 to running without a PTRACE_CONT; so we know this signal will
1372 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1373 probably already in the queue (unless this kernel is old
1374 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1375 is not an RT signal, it can only be queued once. */
1376 kill_lwp (pid, SIGSTOP);
1378 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1379 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1380 ptrace (PTRACE_CONT, pid, 0, 0);
1383 /* Make sure the initial process is stopped. The user-level threads
1384 layer might want to poke around in the inferior, and that won't
1385 work if things haven't stabilized yet. */
1386 new_pid = my_waitpid (pid, &status, 0);
1387 if (new_pid == -1 && errno == ECHILD)
1390 warning (_("%s is a cloned process"), target_pid_to_str (ptid));
1392 /* Try again with __WCLONE to check cloned processes. */
1393 new_pid = my_waitpid (pid, &status, __WCLONE);
1397 gdb_assert (pid == new_pid);
1399 if (!WIFSTOPPED (status))
1401 /* The pid we tried to attach has apparently just exited. */
1402 if (debug_linux_nat)
1403 fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s",
1404 pid, status_to_str (status));
1408 if (WSTOPSIG (status) != SIGSTOP)
1411 if (debug_linux_nat)
1412 fprintf_unfiltered (gdb_stdlog,
1413 "LNPAW: Received %s after attaching\n",
1414 status_to_str (status));
1420 /* Attach to the LWP specified by PID. Return 0 if successful or -1
1421 if the new LWP could not be attached. */
1424 lin_lwp_attach_lwp (ptid_t ptid)
1426 struct lwp_info *lp;
1429 gdb_assert (is_lwp (ptid));
1431 block_child_signals (&prev_mask);
1433 lp = find_lwp_pid (ptid);
1435 /* We assume that we're already attached to any LWP that has an id
1436 equal to the overall process id, and to any LWP that is already
1437 in our list of LWPs. If we're not seeing exit events from threads
1438 and we've had PID wraparound since we last tried to stop all threads,
1439 this assumption might be wrong; fortunately, this is very unlikely
1441 if (GET_LWP (ptid) != GET_PID (ptid) && lp == NULL)
1443 int status, cloned = 0, signalled = 0;
1445 if (ptrace (PTRACE_ATTACH, GET_LWP (ptid), 0, 0) < 0)
1447 /* If we fail to attach to the thread, issue a warning,
1448 but continue. One way this can happen is if thread
1449 creation is interrupted; as of Linux kernel 2.6.19, a
1450 bug may place threads in the thread list and then fail
1452 warning (_("Can't attach %s: %s"), target_pid_to_str (ptid),
1453 safe_strerror (errno));
1454 restore_child_signals_mask (&prev_mask);
1458 if (debug_linux_nat)
1459 fprintf_unfiltered (gdb_stdlog,
1460 "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
1461 target_pid_to_str (ptid));
1463 status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled);
1464 if (!WIFSTOPPED (status))
1466 restore_child_signals_mask (&prev_mask);
1470 lp = add_lwp (ptid);
1472 lp->cloned = cloned;
1473 lp->signalled = signalled;
1474 if (WSTOPSIG (status) != SIGSTOP)
1477 lp->status = status;
1480 target_post_attach (GET_LWP (lp->ptid));
1482 if (debug_linux_nat)
1484 fprintf_unfiltered (gdb_stdlog,
1485 "LLAL: waitpid %s received %s\n",
1486 target_pid_to_str (ptid),
1487 status_to_str (status));
1492 /* We assume that the LWP representing the original process is
1493 already stopped. Mark it as stopped in the data structure
1494 that the GNU/linux ptrace layer uses to keep track of
1495 threads. Note that this won't have already been done since
1496 the main thread will have, we assume, been stopped by an
1497 attach from a different layer. */
1499 lp = add_lwp (ptid);
1503 restore_child_signals_mask (&prev_mask);
1508 linux_nat_create_inferior (struct target_ops *ops,
1509 char *exec_file, char *allargs, char **env,
1512 #ifdef HAVE_PERSONALITY
1513 int personality_orig = 0, personality_set = 0;
1514 #endif /* HAVE_PERSONALITY */
1516 /* The fork_child mechanism is synchronous and calls target_wait, so
1517 we have to mask the async mode. */
1519 #ifdef HAVE_PERSONALITY
1520 if (disable_randomization)
1523 personality_orig = personality (0xffffffff);
1524 if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE))
1526 personality_set = 1;
1527 personality (personality_orig | ADDR_NO_RANDOMIZE);
1529 if (errno != 0 || (personality_set
1530 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE)))
1531 warning (_("Error disabling address space randomization: %s"),
1532 safe_strerror (errno));
1534 #endif /* HAVE_PERSONALITY */
1536 /* Make sure we report all signals during startup. */
1537 linux_nat_pass_signals (0, NULL);
1539 linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty);
1541 #ifdef HAVE_PERSONALITY
1542 if (personality_set)
1545 personality (personality_orig);
1547 warning (_("Error restoring address space randomization: %s"),
1548 safe_strerror (errno));
1550 #endif /* HAVE_PERSONALITY */
1554 linux_nat_attach (struct target_ops *ops, char *args, int from_tty)
1556 struct lwp_info *lp;
1560 /* Make sure we report all signals during attach. */
1561 linux_nat_pass_signals (0, NULL);
1563 linux_ops->to_attach (ops, args, from_tty);
1565 /* The ptrace base target adds the main thread with (pid,0,0)
1566 format. Decorate it with lwp info. */
1567 ptid = BUILD_LWP (GET_PID (inferior_ptid), GET_PID (inferior_ptid));
1568 thread_change_ptid (inferior_ptid, ptid);
1570 /* Add the initial process as the first LWP to the list. */
1571 lp = add_lwp (ptid);
1573 status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->cloned,
1575 if (!WIFSTOPPED (status))
1577 if (WIFEXITED (status))
1579 int exit_code = WEXITSTATUS (status);
1581 target_terminal_ours ();
1582 target_mourn_inferior ();
1584 error (_("Unable to attach: program exited normally."));
1586 error (_("Unable to attach: program exited with code %d."),
1589 else if (WIFSIGNALED (status))
1591 enum target_signal signo;
1593 target_terminal_ours ();
1594 target_mourn_inferior ();
1596 signo = target_signal_from_host (WTERMSIG (status));
1597 error (_("Unable to attach: program terminated with signal "
1599 target_signal_to_name (signo),
1600 target_signal_to_string (signo));
1603 internal_error (__FILE__, __LINE__,
1604 _("unexpected status %d for PID %ld"),
1605 status, (long) GET_LWP (ptid));
1610 /* Save the wait status to report later. */
1612 if (debug_linux_nat)
1613 fprintf_unfiltered (gdb_stdlog,
1614 "LNA: waitpid %ld, saving status %s\n",
1615 (long) GET_PID (lp->ptid), status_to_str (status));
1617 lp->status = status;
1619 if (target_can_async_p ())
1620 target_async (inferior_event_handler, 0);
1623 /* Get pending status of LP. */
1625 get_pending_status (struct lwp_info *lp, int *status)
1627 enum target_signal signo = TARGET_SIGNAL_0;
1629 /* If we paused threads momentarily, we may have stored pending
1630 events in lp->status or lp->waitstatus (see stop_wait_callback),
1631 and GDB core hasn't seen any signal for those threads.
1632 Otherwise, the last signal reported to the core is found in the
1633 thread object's stop_signal.
1635 There's a corner case that isn't handled here at present. Only
1636 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1637 stop_signal make sense as a real signal to pass to the inferior.
1638 Some catchpoint related events, like
1639 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1640 to TARGET_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1641 those traps are debug API (ptrace in our case) related and
1642 induced; the inferior wouldn't see them if it wasn't being
1643 traced. Hence, we should never pass them to the inferior, even
1644 when set to pass state. Since this corner case isn't handled by
1645 infrun.c when proceeding with a signal, for consistency, neither
1646 do we handle it here (or elsewhere in the file we check for
1647 signal pass state). Normally SIGTRAP isn't set to pass state, so
1648 this is really a corner case. */
1650 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
1651 signo = TARGET_SIGNAL_0; /* a pending ptrace event, not a real signal. */
1652 else if (lp->status)
1653 signo = target_signal_from_host (WSTOPSIG (lp->status));
1654 else if (non_stop && !is_executing (lp->ptid))
1656 struct thread_info *tp = find_thread_ptid (lp->ptid);
1658 signo = tp->suspend.stop_signal;
1662 struct target_waitstatus last;
1665 get_last_target_status (&last_ptid, &last);
1667 if (GET_LWP (lp->ptid) == GET_LWP (last_ptid))
1669 struct thread_info *tp = find_thread_ptid (lp->ptid);
1671 signo = tp->suspend.stop_signal;
1677 if (signo == TARGET_SIGNAL_0)
1679 if (debug_linux_nat)
1680 fprintf_unfiltered (gdb_stdlog,
1681 "GPT: lwp %s has no pending signal\n",
1682 target_pid_to_str (lp->ptid));
1684 else if (!signal_pass_state (signo))
1686 if (debug_linux_nat)
1687 fprintf_unfiltered (gdb_stdlog,
1688 "GPT: lwp %s had signal %s, "
1689 "but it is in no pass state\n",
1690 target_pid_to_str (lp->ptid),
1691 target_signal_to_string (signo));
1695 *status = W_STOPCODE (target_signal_to_host (signo));
1697 if (debug_linux_nat)
1698 fprintf_unfiltered (gdb_stdlog,
1699 "GPT: lwp %s has pending signal %s\n",
1700 target_pid_to_str (lp->ptid),
1701 target_signal_to_string (signo));
1708 detach_callback (struct lwp_info *lp, void *data)
1710 gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status));
1712 if (debug_linux_nat && lp->status)
1713 fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n",
1714 strsignal (WSTOPSIG (lp->status)),
1715 target_pid_to_str (lp->ptid));
1717 /* If there is a pending SIGSTOP, get rid of it. */
1720 if (debug_linux_nat)
1721 fprintf_unfiltered (gdb_stdlog,
1722 "DC: Sending SIGCONT to %s\n",
1723 target_pid_to_str (lp->ptid));
1725 kill_lwp (GET_LWP (lp->ptid), SIGCONT);
1729 /* We don't actually detach from the LWP that has an id equal to the
1730 overall process id just yet. */
1731 if (GET_LWP (lp->ptid) != GET_PID (lp->ptid))
1735 /* Pass on any pending signal for this LWP. */
1736 get_pending_status (lp, &status);
1739 if (ptrace (PTRACE_DETACH, GET_LWP (lp->ptid), 0,
1740 WSTOPSIG (status)) < 0)
1741 error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid),
1742 safe_strerror (errno));
1744 if (debug_linux_nat)
1745 fprintf_unfiltered (gdb_stdlog,
1746 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1747 target_pid_to_str (lp->ptid),
1748 strsignal (WSTOPSIG (status)));
1750 delete_lwp (lp->ptid);
1757 linux_nat_detach (struct target_ops *ops, char *args, int from_tty)
1761 struct lwp_info *main_lwp;
1763 pid = GET_PID (inferior_ptid);
1765 if (target_can_async_p ())
1766 linux_nat_async (NULL, 0);
1768 /* Stop all threads before detaching. ptrace requires that the
1769 thread is stopped to sucessfully detach. */
1770 iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL);
1771 /* ... and wait until all of them have reported back that
1772 they're no longer running. */
1773 iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL);
1775 iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL);
1777 /* Only the initial process should be left right now. */
1778 gdb_assert (num_lwps (GET_PID (inferior_ptid)) == 1);
1780 main_lwp = find_lwp_pid (pid_to_ptid (pid));
1782 /* Pass on any pending signal for the last LWP. */
1783 if ((args == NULL || *args == '\0')
1784 && get_pending_status (main_lwp, &status) != -1
1785 && WIFSTOPPED (status))
1787 /* Put the signal number in ARGS so that inf_ptrace_detach will
1788 pass it along with PTRACE_DETACH. */
1790 sprintf (args, "%d", (int) WSTOPSIG (status));
1791 if (debug_linux_nat)
1792 fprintf_unfiltered (gdb_stdlog,
1793 "LND: Sending signal %s to %s\n",
1795 target_pid_to_str (main_lwp->ptid));
1798 delete_lwp (main_lwp->ptid);
1800 if (forks_exist_p ())
1802 /* Multi-fork case. The current inferior_ptid is being detached
1803 from, but there are other viable forks to debug. Detach from
1804 the current fork, and context-switch to the first
1806 linux_fork_detach (args, from_tty);
1808 if (non_stop && target_can_async_p ())
1809 target_async (inferior_event_handler, 0);
1812 linux_ops->to_detach (ops, args, from_tty);
1818 resume_callback (struct lwp_info *lp, void *data)
1820 struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid));
1822 if (lp->stopped && inf->vfork_child != NULL)
1824 if (debug_linux_nat)
1825 fprintf_unfiltered (gdb_stdlog,
1826 "RC: Not resuming %s (vfork parent)\n",
1827 target_pid_to_str (lp->ptid));
1829 else if (lp->stopped && lp->status == 0)
1831 if (debug_linux_nat)
1832 fprintf_unfiltered (gdb_stdlog,
1833 "RC: PTRACE_CONT %s, 0, 0 (resuming sibling)\n",
1834 target_pid_to_str (lp->ptid));
1836 linux_ops->to_resume (linux_ops,
1837 pid_to_ptid (GET_LWP (lp->ptid)),
1838 0, TARGET_SIGNAL_0);
1839 if (debug_linux_nat)
1840 fprintf_unfiltered (gdb_stdlog,
1841 "RC: PTRACE_CONT %s, 0, 0 (resume sibling)\n",
1842 target_pid_to_str (lp->ptid));
1845 memset (&lp->siginfo, 0, sizeof (lp->siginfo));
1846 lp->stopped_by_watchpoint = 0;
1848 else if (lp->stopped && debug_linux_nat)
1849 fprintf_unfiltered (gdb_stdlog,
1850 "RC: Not resuming sibling %s (has pending)\n",
1851 target_pid_to_str (lp->ptid));
1852 else if (debug_linux_nat)
1853 fprintf_unfiltered (gdb_stdlog,
1854 "RC: Not resuming sibling %s (not stopped)\n",
1855 target_pid_to_str (lp->ptid));
1861 resume_clear_callback (struct lwp_info *lp, void *data)
1868 resume_set_callback (struct lwp_info *lp, void *data)
1875 linux_nat_resume (struct target_ops *ops,
1876 ptid_t ptid, int step, enum target_signal signo)
1879 struct lwp_info *lp;
1882 if (debug_linux_nat)
1883 fprintf_unfiltered (gdb_stdlog,
1884 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1885 step ? "step" : "resume",
1886 target_pid_to_str (ptid),
1887 (signo != TARGET_SIGNAL_0
1888 ? strsignal (target_signal_to_host (signo)) : "0"),
1889 target_pid_to_str (inferior_ptid));
1891 block_child_signals (&prev_mask);
1893 /* A specific PTID means `step only this process id'. */
1894 resume_many = (ptid_equal (minus_one_ptid, ptid)
1895 || ptid_is_pid (ptid));
1897 /* Mark the lwps we're resuming as resumed. */
1898 iterate_over_lwps (ptid, resume_set_callback, NULL);
1900 /* See if it's the current inferior that should be handled
1903 lp = find_lwp_pid (inferior_ptid);
1905 lp = find_lwp_pid (ptid);
1906 gdb_assert (lp != NULL);
1908 /* Remember if we're stepping. */
1911 /* If we have a pending wait status for this thread, there is no
1912 point in resuming the process. But first make sure that
1913 linux_nat_wait won't preemptively handle the event - we
1914 should never take this short-circuit if we are going to
1915 leave LP running, since we have skipped resuming all the
1916 other threads. This bit of code needs to be synchronized
1917 with linux_nat_wait. */
1919 if (lp->status && WIFSTOPPED (lp->status))
1922 && WSTOPSIG (lp->status)
1923 && sigismember (&pass_mask, WSTOPSIG (lp->status)))
1925 if (debug_linux_nat)
1926 fprintf_unfiltered (gdb_stdlog,
1927 "LLR: Not short circuiting for ignored "
1928 "status 0x%x\n", lp->status);
1930 /* FIXME: What should we do if we are supposed to continue
1931 this thread with a signal? */
1932 gdb_assert (signo == TARGET_SIGNAL_0);
1933 signo = target_signal_from_host (WSTOPSIG (lp->status));
1938 if (lp->status || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
1940 /* FIXME: What should we do if we are supposed to continue
1941 this thread with a signal? */
1942 gdb_assert (signo == TARGET_SIGNAL_0);
1944 if (debug_linux_nat)
1945 fprintf_unfiltered (gdb_stdlog,
1946 "LLR: Short circuiting for status 0x%x\n",
1949 restore_child_signals_mask (&prev_mask);
1950 if (target_can_async_p ())
1952 target_async (inferior_event_handler, 0);
1953 /* Tell the event loop we have something to process. */
1959 /* Mark LWP as not stopped to prevent it from being continued by
1964 iterate_over_lwps (ptid, resume_callback, NULL);
1966 /* Convert to something the lower layer understands. */
1967 ptid = pid_to_ptid (GET_LWP (lp->ptid));
1969 linux_ops->to_resume (linux_ops, ptid, step, signo);
1970 memset (&lp->siginfo, 0, sizeof (lp->siginfo));
1971 lp->stopped_by_watchpoint = 0;
1973 if (debug_linux_nat)
1974 fprintf_unfiltered (gdb_stdlog,
1975 "LLR: %s %s, %s (resume event thread)\n",
1976 step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1977 target_pid_to_str (ptid),
1978 (signo != TARGET_SIGNAL_0
1979 ? strsignal (target_signal_to_host (signo)) : "0"));
1981 restore_child_signals_mask (&prev_mask);
1982 if (target_can_async_p ())
1983 target_async (inferior_event_handler, 0);
1986 /* Send a signal to an LWP. */
1989 kill_lwp (int lwpid, int signo)
1991 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1992 fails, then we are not using nptl threads and we should be using kill. */
1994 #ifdef HAVE_TKILL_SYSCALL
1996 static int tkill_failed;
2003 ret = syscall (__NR_tkill, lwpid, signo);
2004 if (errno != ENOSYS)
2011 return kill (lwpid, signo);
2014 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
2015 event, check if the core is interested in it: if not, ignore the
2016 event, and keep waiting; otherwise, we need to toggle the LWP's
2017 syscall entry/exit status, since the ptrace event itself doesn't
2018 indicate it, and report the trap to higher layers. */
2021 linux_handle_syscall_trap (struct lwp_info *lp, int stopping)
2023 struct target_waitstatus *ourstatus = &lp->waitstatus;
2024 struct gdbarch *gdbarch = target_thread_architecture (lp->ptid);
2025 int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid);
2029 /* If we're stopping threads, there's a SIGSTOP pending, which
2030 makes it so that the LWP reports an immediate syscall return,
2031 followed by the SIGSTOP. Skip seeing that "return" using
2032 PTRACE_CONT directly, and let stop_wait_callback collect the
2033 SIGSTOP. Later when the thread is resumed, a new syscall
2034 entry event. If we didn't do this (and returned 0), we'd
2035 leave a syscall entry pending, and our caller, by using
2036 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
2037 itself. Later, when the user re-resumes this LWP, we'd see
2038 another syscall entry event and we'd mistake it for a return.
2040 If stop_wait_callback didn't force the SIGSTOP out of the LWP
2041 (leaving immediately with LWP->signalled set, without issuing
2042 a PTRACE_CONT), it would still be problematic to leave this
2043 syscall enter pending, as later when the thread is resumed,
2044 it would then see the same syscall exit mentioned above,
2045 followed by the delayed SIGSTOP, while the syscall didn't
2046 actually get to execute. It seems it would be even more
2047 confusing to the user. */
2049 if (debug_linux_nat)
2050 fprintf_unfiltered (gdb_stdlog,
2051 "LHST: ignoring syscall %d "
2052 "for LWP %ld (stopping threads), "
2053 "resuming with PTRACE_CONT for SIGSTOP\n",
2055 GET_LWP (lp->ptid));
2057 lp->syscall_state = TARGET_WAITKIND_IGNORE;
2058 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2062 if (catch_syscall_enabled ())
2064 /* Always update the entry/return state, even if this particular
2065 syscall isn't interesting to the core now. In async mode,
2066 the user could install a new catchpoint for this syscall
2067 between syscall enter/return, and we'll need to know to
2068 report a syscall return if that happens. */
2069 lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
2070 ? TARGET_WAITKIND_SYSCALL_RETURN
2071 : TARGET_WAITKIND_SYSCALL_ENTRY);
2073 if (catching_syscall_number (syscall_number))
2075 /* Alright, an event to report. */
2076 ourstatus->kind = lp->syscall_state;
2077 ourstatus->value.syscall_number = syscall_number;
2079 if (debug_linux_nat)
2080 fprintf_unfiltered (gdb_stdlog,
2081 "LHST: stopping for %s of syscall %d"
2084 == TARGET_WAITKIND_SYSCALL_ENTRY
2085 ? "entry" : "return",
2087 GET_LWP (lp->ptid));
2091 if (debug_linux_nat)
2092 fprintf_unfiltered (gdb_stdlog,
2093 "LHST: ignoring %s of syscall %d "
2095 lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
2096 ? "entry" : "return",
2098 GET_LWP (lp->ptid));
2102 /* If we had been syscall tracing, and hence used PT_SYSCALL
2103 before on this LWP, it could happen that the user removes all
2104 syscall catchpoints before we get to process this event.
2105 There are two noteworthy issues here:
2107 - When stopped at a syscall entry event, resuming with
2108 PT_STEP still resumes executing the syscall and reports a
2111 - Only PT_SYSCALL catches syscall enters. If we last
2112 single-stepped this thread, then this event can't be a
2113 syscall enter. If we last single-stepped this thread, this
2114 has to be a syscall exit.
2116 The points above mean that the next resume, be it PT_STEP or
2117 PT_CONTINUE, can not trigger a syscall trace event. */
2118 if (debug_linux_nat)
2119 fprintf_unfiltered (gdb_stdlog,
2120 "LHST: caught syscall event "
2121 "with no syscall catchpoints."
2122 " %d for LWP %ld, ignoring\n",
2124 GET_LWP (lp->ptid));
2125 lp->syscall_state = TARGET_WAITKIND_IGNORE;
2128 /* The core isn't interested in this event. For efficiency, avoid
2129 stopping all threads only to have the core resume them all again.
2130 Since we're not stopping threads, if we're still syscall tracing
2131 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
2132 subsequent syscall. Simply resume using the inf-ptrace layer,
2133 which knows when to use PT_SYSCALL or PT_CONTINUE. */
2135 /* Note that gdbarch_get_syscall_number may access registers, hence
2137 registers_changed ();
2138 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
2139 lp->step, TARGET_SIGNAL_0);
2143 /* Handle a GNU/Linux extended wait response. If we see a clone
2144 event, we need to add the new LWP to our list (and not report the
2145 trap to higher layers). This function returns non-zero if the
2146 event should be ignored and we should wait again. If STOPPING is
2147 true, the new LWP remains stopped, otherwise it is continued. */
2150 linux_handle_extended_wait (struct lwp_info *lp, int status,
2153 int pid = GET_LWP (lp->ptid);
2154 struct target_waitstatus *ourstatus = &lp->waitstatus;
2155 int event = status >> 16;
2157 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK
2158 || event == PTRACE_EVENT_CLONE)
2160 unsigned long new_pid;
2163 ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid);
2165 /* If we haven't already seen the new PID stop, wait for it now. */
2166 if (! pull_pid_from_list (&stopped_pids, new_pid, &status))
2168 /* The new child has a pending SIGSTOP. We can't affect it until it
2169 hits the SIGSTOP, but we're already attached. */
2170 ret = my_waitpid (new_pid, &status,
2171 (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0);
2173 perror_with_name (_("waiting for new child"));
2174 else if (ret != new_pid)
2175 internal_error (__FILE__, __LINE__,
2176 _("wait returned unexpected PID %d"), ret);
2177 else if (!WIFSTOPPED (status))
2178 internal_error (__FILE__, __LINE__,
2179 _("wait returned unexpected status 0x%x"), status);
2182 ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0);
2184 if (event == PTRACE_EVENT_FORK
2185 && linux_fork_checkpointing_p (GET_PID (lp->ptid)))
2187 /* Handle checkpointing by linux-fork.c here as a special
2188 case. We don't want the follow-fork-mode or 'catch fork'
2189 to interfere with this. */
2191 /* This won't actually modify the breakpoint list, but will
2192 physically remove the breakpoints from the child. */
2193 detach_breakpoints (new_pid);
2195 /* Retain child fork in ptrace (stopped) state. */
2196 if (!find_fork_pid (new_pid))
2199 /* Report as spurious, so that infrun doesn't want to follow
2200 this fork. We're actually doing an infcall in
2202 ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
2203 linux_enable_event_reporting (pid_to_ptid (new_pid));
2205 /* Report the stop to the core. */
2209 if (event == PTRACE_EVENT_FORK)
2210 ourstatus->kind = TARGET_WAITKIND_FORKED;
2211 else if (event == PTRACE_EVENT_VFORK)
2212 ourstatus->kind = TARGET_WAITKIND_VFORKED;
2215 struct lwp_info *new_lp;
2217 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2219 new_lp = add_lwp (BUILD_LWP (new_pid, GET_PID (lp->ptid)));
2221 new_lp->stopped = 1;
2223 if (WSTOPSIG (status) != SIGSTOP)
2225 /* This can happen if someone starts sending signals to
2226 the new thread before it gets a chance to run, which
2227 have a lower number than SIGSTOP (e.g. SIGUSR1).
2228 This is an unlikely case, and harder to handle for
2229 fork / vfork than for clone, so we do not try - but
2230 we handle it for clone events here. We'll send
2231 the other signal on to the thread below. */
2233 new_lp->signalled = 1;
2240 /* Add the new thread to GDB's lists as soon as possible
2243 1) the frontend doesn't have to wait for a stop to
2246 2) we tag it with the correct running state. */
2248 /* If the thread_db layer is active, let it know about
2249 this new thread, and add it to GDB's list. */
2250 if (!thread_db_attach_lwp (new_lp->ptid))
2252 /* We're not using thread_db. Add it to GDB's
2254 target_post_attach (GET_LWP (new_lp->ptid));
2255 add_thread (new_lp->ptid);
2260 set_running (new_lp->ptid, 1);
2261 set_executing (new_lp->ptid, 1);
2265 /* Note the need to use the low target ops to resume, to
2266 handle resuming with PT_SYSCALL if we have syscall
2270 enum target_signal signo;
2272 new_lp->stopped = 0;
2273 new_lp->resumed = 1;
2276 ? target_signal_from_host (WSTOPSIG (status))
2279 linux_ops->to_resume (linux_ops, pid_to_ptid (new_pid),
2286 /* We created NEW_LP so it cannot yet contain STATUS. */
2287 gdb_assert (new_lp->status == 0);
2289 /* Save the wait status to report later. */
2290 if (debug_linux_nat)
2291 fprintf_unfiltered (gdb_stdlog,
2292 "LHEW: waitpid of new LWP %ld, "
2293 "saving status %s\n",
2294 (long) GET_LWP (new_lp->ptid),
2295 status_to_str (status));
2296 new_lp->status = status;
2300 if (debug_linux_nat)
2301 fprintf_unfiltered (gdb_stdlog,
2302 "LHEW: Got clone event "
2303 "from LWP %ld, resuming\n",
2304 GET_LWP (lp->ptid));
2305 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
2306 0, TARGET_SIGNAL_0);
2314 if (event == PTRACE_EVENT_EXEC)
2316 if (debug_linux_nat)
2317 fprintf_unfiltered (gdb_stdlog,
2318 "LHEW: Got exec event from LWP %ld\n",
2319 GET_LWP (lp->ptid));
2321 ourstatus->kind = TARGET_WAITKIND_EXECD;
2322 ourstatus->value.execd_pathname
2323 = xstrdup (linux_child_pid_to_exec_file (pid));
2328 if (event == PTRACE_EVENT_VFORK_DONE)
2330 if (current_inferior ()->waiting_for_vfork_done)
2332 if (debug_linux_nat)
2333 fprintf_unfiltered (gdb_stdlog,
2334 "LHEW: Got expected PTRACE_EVENT_"
2335 "VFORK_DONE from LWP %ld: stopping\n",
2336 GET_LWP (lp->ptid));
2338 ourstatus->kind = TARGET_WAITKIND_VFORK_DONE;
2342 if (debug_linux_nat)
2343 fprintf_unfiltered (gdb_stdlog,
2344 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2345 "from LWP %ld: resuming\n",
2346 GET_LWP (lp->ptid));
2347 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2351 internal_error (__FILE__, __LINE__,
2352 _("unknown ptrace event %d"), event);
2355 /* Return non-zero if LWP is a zombie. */
2358 linux_lwp_is_zombie (long lwp)
2360 char buffer[MAXPATHLEN];
2364 xsnprintf (buffer, sizeof (buffer), "/proc/%ld/status", lwp);
2365 procfile = fopen (buffer, "r");
2366 if (procfile == NULL)
2368 warning (_("unable to open /proc file '%s'"), buffer);
2371 while (fgets (buffer, sizeof (buffer), procfile) != NULL)
2372 if (strcmp (buffer, "State:\tZ (zombie)\n") == 0)
2382 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2386 wait_lwp (struct lwp_info *lp)
2390 int thread_dead = 0;
2393 gdb_assert (!lp->stopped);
2394 gdb_assert (lp->status == 0);
2396 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2397 block_child_signals (&prev_mask);
2401 /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind
2402 was right and we should just call sigsuspend. */
2404 pid = my_waitpid (GET_LWP (lp->ptid), &status, WNOHANG);
2405 if (pid == -1 && errno == ECHILD)
2406 pid = my_waitpid (GET_LWP (lp->ptid), &status, __WCLONE | WNOHANG);
2410 /* Bugs 10970, 12702.
2411 Thread group leader may have exited in which case we'll lock up in
2412 waitpid if there are other threads, even if they are all zombies too.
2413 Basically, we're not supposed to use waitpid this way.
2414 __WCLONE is not applicable for the leader so we can't use that.
2415 LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED
2416 process; it gets ESRCH both for the zombie and for running processes.
2418 As a workaround, check if we're waiting for the thread group leader and
2419 if it's a zombie, and avoid calling waitpid if it is.
2421 This is racy, what if the tgl becomes a zombie right after we check?
2422 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2423 waiting waitpid but the linux_lwp_is_zombie is safe this way. */
2425 if (GET_PID (lp->ptid) == GET_LWP (lp->ptid)
2426 && linux_lwp_is_zombie (GET_LWP (lp->ptid)))
2429 if (debug_linux_nat)
2430 fprintf_unfiltered (gdb_stdlog,
2431 "WL: Thread group leader %s vanished.\n",
2432 target_pid_to_str (lp->ptid));
2436 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2437 get invoked despite our caller had them intentionally blocked by
2438 block_child_signals. This is sensitive only to the loop of
2439 linux_nat_wait_1 and there if we get called my_waitpid gets called
2440 again before it gets to sigsuspend so we can safely let the handlers
2441 get executed here. */
2443 sigsuspend (&suspend_mask);
2446 restore_child_signals_mask (&prev_mask);
2448 if (pid == -1 && errno == ECHILD)
2450 /* The thread has previously exited. We need to delete it
2451 now because, for some vendor 2.4 kernels with NPTL
2452 support backported, there won't be an exit event unless
2453 it is the main thread. 2.6 kernels will report an exit
2454 event for each thread that exits, as expected. */
2456 if (debug_linux_nat)
2457 fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
2458 target_pid_to_str (lp->ptid));
2463 gdb_assert (pid == GET_LWP (lp->ptid));
2465 if (debug_linux_nat)
2467 fprintf_unfiltered (gdb_stdlog,
2468 "WL: waitpid %s received %s\n",
2469 target_pid_to_str (lp->ptid),
2470 status_to_str (status));
2474 /* Check if the thread has exited. */
2475 if (WIFEXITED (status) || WIFSIGNALED (status))
2478 if (debug_linux_nat)
2479 fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n",
2480 target_pid_to_str (lp->ptid));
2489 gdb_assert (WIFSTOPPED (status));
2491 /* Handle GNU/Linux's syscall SIGTRAPs. */
2492 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
2494 /* No longer need the sysgood bit. The ptrace event ends up
2495 recorded in lp->waitstatus if we care for it. We can carry
2496 on handling the event like a regular SIGTRAP from here
2498 status = W_STOPCODE (SIGTRAP);
2499 if (linux_handle_syscall_trap (lp, 1))
2500 return wait_lwp (lp);
2503 /* Handle GNU/Linux's extended waitstatus for trace events. */
2504 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
2506 if (debug_linux_nat)
2507 fprintf_unfiltered (gdb_stdlog,
2508 "WL: Handling extended status 0x%06x\n",
2510 if (linux_handle_extended_wait (lp, status, 1))
2511 return wait_lwp (lp);
2517 /* Save the most recent siginfo for LP. This is currently only called
2518 for SIGTRAP; some ports use the si_addr field for
2519 target_stopped_data_address. In the future, it may also be used to
2520 restore the siginfo of requeued signals. */
2523 save_siginfo (struct lwp_info *lp)
2526 ptrace (PTRACE_GETSIGINFO, GET_LWP (lp->ptid),
2527 (PTRACE_TYPE_ARG3) 0, &lp->siginfo);
2530 memset (&lp->siginfo, 0, sizeof (lp->siginfo));
2533 /* Send a SIGSTOP to LP. */
2536 stop_callback (struct lwp_info *lp, void *data)
2538 if (!lp->stopped && !lp->signalled)
2542 if (debug_linux_nat)
2544 fprintf_unfiltered (gdb_stdlog,
2545 "SC: kill %s **<SIGSTOP>**\n",
2546 target_pid_to_str (lp->ptid));
2549 ret = kill_lwp (GET_LWP (lp->ptid), SIGSTOP);
2550 if (debug_linux_nat)
2552 fprintf_unfiltered (gdb_stdlog,
2553 "SC: lwp kill %d %s\n",
2555 errno ? safe_strerror (errno) : "ERRNO-OK");
2559 gdb_assert (lp->status == 0);
2565 /* Return non-zero if LWP PID has a pending SIGINT. */
2568 linux_nat_has_pending_sigint (int pid)
2570 sigset_t pending, blocked, ignored;
2572 linux_proc_pending_signals (pid, &pending, &blocked, &ignored);
2574 if (sigismember (&pending, SIGINT)
2575 && !sigismember (&ignored, SIGINT))
2581 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2584 set_ignore_sigint (struct lwp_info *lp, void *data)
2586 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2587 flag to consume the next one. */
2588 if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status)
2589 && WSTOPSIG (lp->status) == SIGINT)
2592 lp->ignore_sigint = 1;
2597 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2598 This function is called after we know the LWP has stopped; if the LWP
2599 stopped before the expected SIGINT was delivered, then it will never have
2600 arrived. Also, if the signal was delivered to a shared queue and consumed
2601 by a different thread, it will never be delivered to this LWP. */
2604 maybe_clear_ignore_sigint (struct lwp_info *lp)
2606 if (!lp->ignore_sigint)
2609 if (!linux_nat_has_pending_sigint (GET_LWP (lp->ptid)))
2611 if (debug_linux_nat)
2612 fprintf_unfiltered (gdb_stdlog,
2613 "MCIS: Clearing bogus flag for %s\n",
2614 target_pid_to_str (lp->ptid));
2615 lp->ignore_sigint = 0;
2619 /* Fetch the possible triggered data watchpoint info and store it in
2622 On some archs, like x86, that use debug registers to set
2623 watchpoints, it's possible that the way to know which watched
2624 address trapped, is to check the register that is used to select
2625 which address to watch. Problem is, between setting the watchpoint
2626 and reading back which data address trapped, the user may change
2627 the set of watchpoints, and, as a consequence, GDB changes the
2628 debug registers in the inferior. To avoid reading back a stale
2629 stopped-data-address when that happens, we cache in LP the fact
2630 that a watchpoint trapped, and the corresponding data address, as
2631 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2632 registers meanwhile, we have the cached data we can rely on. */
2635 save_sigtrap (struct lwp_info *lp)
2637 struct cleanup *old_chain;
2639 if (linux_ops->to_stopped_by_watchpoint == NULL)
2641 lp->stopped_by_watchpoint = 0;
2645 old_chain = save_inferior_ptid ();
2646 inferior_ptid = lp->ptid;
2648 lp->stopped_by_watchpoint = linux_ops->to_stopped_by_watchpoint ();
2650 if (lp->stopped_by_watchpoint)
2652 if (linux_ops->to_stopped_data_address != NULL)
2653 lp->stopped_data_address_p =
2654 linux_ops->to_stopped_data_address (¤t_target,
2655 &lp->stopped_data_address);
2657 lp->stopped_data_address_p = 0;
2660 do_cleanups (old_chain);
2663 /* See save_sigtrap. */
2666 linux_nat_stopped_by_watchpoint (void)
2668 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2670 gdb_assert (lp != NULL);
2672 return lp->stopped_by_watchpoint;
2676 linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
2678 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2680 gdb_assert (lp != NULL);
2682 *addr_p = lp->stopped_data_address;
2684 return lp->stopped_data_address_p;
2687 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2690 sigtrap_is_event (int status)
2692 return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP;
2695 /* SIGTRAP-like events recognizer. */
2697 static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event;
2699 /* Check for SIGTRAP-like events in LP. */
2702 linux_nat_lp_status_is_event (struct lwp_info *lp)
2704 /* We check for lp->waitstatus in addition to lp->status, because we can
2705 have pending process exits recorded in lp->status
2706 and W_EXITCODE(0,0) == 0. We should probably have an additional
2707 lp->status_p flag. */
2709 return (lp->waitstatus.kind == TARGET_WAITKIND_IGNORE
2710 && linux_nat_status_is_event (lp->status));
2713 /* Set alternative SIGTRAP-like events recognizer. If
2714 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2718 linux_nat_set_status_is_event (struct target_ops *t,
2719 int (*status_is_event) (int status))
2721 linux_nat_status_is_event = status_is_event;
2724 /* Wait until LP is stopped. */
2727 stop_wait_callback (struct lwp_info *lp, void *data)
2729 struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid));
2731 /* If this is a vfork parent, bail out, it is not going to report
2732 any SIGSTOP until the vfork is done with. */
2733 if (inf->vfork_child != NULL)
2740 status = wait_lwp (lp);
2744 if (lp->ignore_sigint && WIFSTOPPED (status)
2745 && WSTOPSIG (status) == SIGINT)
2747 lp->ignore_sigint = 0;
2750 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2751 if (debug_linux_nat)
2752 fprintf_unfiltered (gdb_stdlog,
2753 "PTRACE_CONT %s, 0, 0 (%s) "
2754 "(discarding SIGINT)\n",
2755 target_pid_to_str (lp->ptid),
2756 errno ? safe_strerror (errno) : "OK");
2758 return stop_wait_callback (lp, NULL);
2761 maybe_clear_ignore_sigint (lp);
2763 if (WSTOPSIG (status) != SIGSTOP)
2765 if (linux_nat_status_is_event (status))
2767 /* If a LWP other than the LWP that we're reporting an
2768 event for has hit a GDB breakpoint (as opposed to
2769 some random trap signal), then just arrange for it to
2770 hit it again later. We don't keep the SIGTRAP status
2771 and don't forward the SIGTRAP signal to the LWP. We
2772 will handle the current event, eventually we will
2773 resume all LWPs, and this one will get its breakpoint
2776 If we do not do this, then we run the risk that the
2777 user will delete or disable the breakpoint, but the
2778 thread will have already tripped on it. */
2780 /* Save the trap's siginfo in case we need it later. */
2785 /* Now resume this LWP and get the SIGSTOP event. */
2787 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2788 if (debug_linux_nat)
2790 fprintf_unfiltered (gdb_stdlog,
2791 "PTRACE_CONT %s, 0, 0 (%s)\n",
2792 target_pid_to_str (lp->ptid),
2793 errno ? safe_strerror (errno) : "OK");
2795 fprintf_unfiltered (gdb_stdlog,
2796 "SWC: Candidate SIGTRAP event in %s\n",
2797 target_pid_to_str (lp->ptid));
2799 /* Hold this event/waitstatus while we check to see if
2800 there are any more (we still want to get that SIGSTOP). */
2801 stop_wait_callback (lp, NULL);
2803 /* Hold the SIGTRAP for handling by linux_nat_wait. If
2804 there's another event, throw it back into the
2808 if (debug_linux_nat)
2809 fprintf_unfiltered (gdb_stdlog,
2810 "SWC: kill %s, %s\n",
2811 target_pid_to_str (lp->ptid),
2812 status_to_str ((int) status));
2813 kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (lp->status));
2816 /* Save the sigtrap event. */
2817 lp->status = status;
2822 /* The thread was stopped with a signal other than
2823 SIGSTOP, and didn't accidentally trip a breakpoint. */
2825 if (debug_linux_nat)
2827 fprintf_unfiltered (gdb_stdlog,
2828 "SWC: Pending event %s in %s\n",
2829 status_to_str ((int) status),
2830 target_pid_to_str (lp->ptid));
2832 /* Now resume this LWP and get the SIGSTOP event. */
2834 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2835 if (debug_linux_nat)
2836 fprintf_unfiltered (gdb_stdlog,
2837 "SWC: PTRACE_CONT %s, 0, 0 (%s)\n",
2838 target_pid_to_str (lp->ptid),
2839 errno ? safe_strerror (errno) : "OK");
2841 /* Hold this event/waitstatus while we check to see if
2842 there are any more (we still want to get that SIGSTOP). */
2843 stop_wait_callback (lp, NULL);
2845 /* If the lp->status field is still empty, use it to
2846 hold this event. If not, then this event must be
2847 returned to the event queue of the LWP. */
2850 if (debug_linux_nat)
2852 fprintf_unfiltered (gdb_stdlog,
2853 "SWC: kill %s, %s\n",
2854 target_pid_to_str (lp->ptid),
2855 status_to_str ((int) status));
2857 kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (status));
2860 lp->status = status;
2866 /* We caught the SIGSTOP that we intended to catch, so
2867 there's no SIGSTOP pending. */
2876 /* Return non-zero if LP has a wait status pending. */
2879 status_callback (struct lwp_info *lp, void *data)
2881 /* Only report a pending wait status if we pretend that this has
2882 indeed been resumed. */
2886 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
2888 /* A ptrace event, like PTRACE_FORK|VFORK|EXEC, syscall event,
2889 or a pending process exit. Note that `W_EXITCODE(0,0) ==
2890 0', so a clean process exit can not be stored pending in
2891 lp->status, it is indistinguishable from
2892 no-pending-status. */
2896 if (lp->status != 0)
2902 /* Return non-zero if LP isn't stopped. */
2905 running_callback (struct lwp_info *lp, void *data)
2907 return (lp->stopped == 0 || (lp->status != 0 && lp->resumed));
2910 /* Count the LWP's that have had events. */
2913 count_events_callback (struct lwp_info *lp, void *data)
2917 gdb_assert (count != NULL);
2919 /* Count only resumed LWPs that have a SIGTRAP event pending. */
2920 if (lp->resumed && linux_nat_lp_status_is_event (lp))
2926 /* Select the LWP (if any) that is currently being single-stepped. */
2929 select_singlestep_lwp_callback (struct lwp_info *lp, void *data)
2931 if (lp->step && lp->status != 0)
2937 /* Select the Nth LWP that has had a SIGTRAP event. */
2940 select_event_lwp_callback (struct lwp_info *lp, void *data)
2942 int *selector = data;
2944 gdb_assert (selector != NULL);
2946 /* Select only resumed LWPs that have a SIGTRAP event pending. */
2947 if (lp->resumed && linux_nat_lp_status_is_event (lp))
2948 if ((*selector)-- == 0)
2955 cancel_breakpoint (struct lwp_info *lp)
2957 /* Arrange for a breakpoint to be hit again later. We don't keep
2958 the SIGTRAP status and don't forward the SIGTRAP signal to the
2959 LWP. We will handle the current event, eventually we will resume
2960 this LWP, and this breakpoint will trap again.
2962 If we do not do this, then we run the risk that the user will
2963 delete or disable the breakpoint, but the LWP will have already
2966 struct regcache *regcache = get_thread_regcache (lp->ptid);
2967 struct gdbarch *gdbarch = get_regcache_arch (regcache);
2970 pc = regcache_read_pc (regcache) - gdbarch_decr_pc_after_break (gdbarch);
2971 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
2973 if (debug_linux_nat)
2974 fprintf_unfiltered (gdb_stdlog,
2975 "CB: Push back breakpoint for %s\n",
2976 target_pid_to_str (lp->ptid));
2978 /* Back up the PC if necessary. */
2979 if (gdbarch_decr_pc_after_break (gdbarch))
2980 regcache_write_pc (regcache, pc);
2988 cancel_breakpoints_callback (struct lwp_info *lp, void *data)
2990 struct lwp_info *event_lp = data;
2992 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
2996 /* If a LWP other than the LWP that we're reporting an event for has
2997 hit a GDB breakpoint (as opposed to some random trap signal),
2998 then just arrange for it to hit it again later. We don't keep
2999 the SIGTRAP status and don't forward the SIGTRAP signal to the
3000 LWP. We will handle the current event, eventually we will resume
3001 all LWPs, and this one will get its breakpoint trap again.
3003 If we do not do this, then we run the risk that the user will
3004 delete or disable the breakpoint, but the LWP will have already
3007 if (linux_nat_lp_status_is_event (lp)
3008 && cancel_breakpoint (lp))
3009 /* Throw away the SIGTRAP. */
3015 /* Select one LWP out of those that have events pending. */
3018 select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status)
3021 int random_selector;
3022 struct lwp_info *event_lp;
3024 /* Record the wait status for the original LWP. */
3025 (*orig_lp)->status = *status;
3027 /* Give preference to any LWP that is being single-stepped. */
3028 event_lp = iterate_over_lwps (filter,
3029 select_singlestep_lwp_callback, NULL);
3030 if (event_lp != NULL)
3032 if (debug_linux_nat)
3033 fprintf_unfiltered (gdb_stdlog,
3034 "SEL: Select single-step %s\n",
3035 target_pid_to_str (event_lp->ptid));
3039 /* No single-stepping LWP. Select one at random, out of those
3040 which have had SIGTRAP events. */
3042 /* First see how many SIGTRAP events we have. */
3043 iterate_over_lwps (filter, count_events_callback, &num_events);
3045 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
3046 random_selector = (int)
3047 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
3049 if (debug_linux_nat && num_events > 1)
3050 fprintf_unfiltered (gdb_stdlog,
3051 "SEL: Found %d SIGTRAP events, selecting #%d\n",
3052 num_events, random_selector);
3054 event_lp = iterate_over_lwps (filter,
3055 select_event_lwp_callback,
3059 if (event_lp != NULL)
3061 /* Switch the event LWP. */
3062 *orig_lp = event_lp;
3063 *status = event_lp->status;
3066 /* Flush the wait status for the event LWP. */
3067 (*orig_lp)->status = 0;
3070 /* Return non-zero if LP has been resumed. */
3073 resumed_callback (struct lwp_info *lp, void *data)
3078 /* Stop an active thread, verify it still exists, then resume it. */
3081 stop_and_resume_callback (struct lwp_info *lp, void *data)
3083 struct lwp_info *ptr;
3085 if (!lp->stopped && !lp->signalled)
3087 stop_callback (lp, NULL);
3088 stop_wait_callback (lp, NULL);
3089 /* Resume if the lwp still exists. */
3090 for (ptr = lwp_list; ptr; ptr = ptr->next)
3093 resume_callback (lp, NULL);
3094 resume_set_callback (lp, NULL);
3100 /* Check if we should go on and pass this event to common code.
3101 Return the affected lwp if we are, or NULL otherwise. */
3102 static struct lwp_info *
3103 linux_nat_filter_event (int lwpid, int status, int options)
3105 struct lwp_info *lp;
3107 lp = find_lwp_pid (pid_to_ptid (lwpid));
3109 /* Check for stop events reported by a process we didn't already
3110 know about - anything not already in our LWP list.
3112 If we're expecting to receive stopped processes after
3113 fork, vfork, and clone events, then we'll just add the
3114 new one to our list and go back to waiting for the event
3115 to be reported - the stopped process might be returned
3116 from waitpid before or after the event is. */
3117 if (WIFSTOPPED (status) && !lp)
3119 linux_record_stopped_pid (lwpid, status);
3123 /* Make sure we don't report an event for the exit of an LWP not in
3124 our list, i.e. not part of the current process. This can happen
3125 if we detach from a program we originally forked and then it
3127 if (!WIFSTOPPED (status) && !lp)
3130 /* NOTE drow/2003-06-17: This code seems to be meant for debugging
3131 CLONE_PTRACE processes which do not use the thread library -
3132 otherwise we wouldn't find the new LWP this way. That doesn't
3133 currently work, and the following code is currently unreachable
3134 due to the two blocks above. If it's fixed some day, this code
3135 should be broken out into a function so that we can also pick up
3136 LWPs from the new interface. */
3139 lp = add_lwp (BUILD_LWP (lwpid, GET_PID (inferior_ptid)));
3140 if (options & __WCLONE)
3143 gdb_assert (WIFSTOPPED (status)
3144 && WSTOPSIG (status) == SIGSTOP);
3147 if (!in_thread_list (inferior_ptid))
3149 inferior_ptid = BUILD_LWP (GET_PID (inferior_ptid),
3150 GET_PID (inferior_ptid));
3151 add_thread (inferior_ptid);
3154 add_thread (lp->ptid);
3157 /* Handle GNU/Linux's syscall SIGTRAPs. */
3158 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
3160 /* No longer need the sysgood bit. The ptrace event ends up
3161 recorded in lp->waitstatus if we care for it. We can carry
3162 on handling the event like a regular SIGTRAP from here
3164 status = W_STOPCODE (SIGTRAP);
3165 if (linux_handle_syscall_trap (lp, 0))
3169 /* Handle GNU/Linux's extended waitstatus for trace events. */
3170 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
3172 if (debug_linux_nat)
3173 fprintf_unfiltered (gdb_stdlog,
3174 "LLW: Handling extended status 0x%06x\n",
3176 if (linux_handle_extended_wait (lp, status, 0))
3180 if (linux_nat_status_is_event (status))
3182 /* Save the trap's siginfo in case we need it later. */
3188 /* Check if the thread has exited. */
3189 if ((WIFEXITED (status) || WIFSIGNALED (status))
3190 && num_lwps (GET_PID (lp->ptid)) > 1)
3192 /* If this is the main thread, we must stop all threads and verify
3193 if they are still alive. This is because in the nptl thread model
3194 on Linux 2.4, there is no signal issued for exiting LWPs
3195 other than the main thread. We only get the main thread exit
3196 signal once all child threads have already exited. If we
3197 stop all the threads and use the stop_wait_callback to check
3198 if they have exited we can determine whether this signal
3199 should be ignored or whether it means the end of the debugged
3200 application, regardless of which threading model is being
3202 if (GET_PID (lp->ptid) == GET_LWP (lp->ptid))
3205 iterate_over_lwps (pid_to_ptid (GET_PID (lp->ptid)),
3206 stop_and_resume_callback, NULL);
3209 if (debug_linux_nat)
3210 fprintf_unfiltered (gdb_stdlog,
3211 "LLW: %s exited.\n",
3212 target_pid_to_str (lp->ptid));
3214 if (num_lwps (GET_PID (lp->ptid)) > 1)
3216 /* If there is at least one more LWP, then the exit signal
3217 was not the end of the debugged application and should be
3224 /* Check if the current LWP has previously exited. In the nptl
3225 thread model, LWPs other than the main thread do not issue
3226 signals when they exit so we must check whenever the thread has
3227 stopped. A similar check is made in stop_wait_callback(). */
3228 if (num_lwps (GET_PID (lp->ptid)) > 1 && !linux_thread_alive (lp->ptid))
3230 ptid_t ptid = pid_to_ptid (GET_PID (lp->ptid));
3232 if (debug_linux_nat)
3233 fprintf_unfiltered (gdb_stdlog,
3234 "LLW: %s exited.\n",
3235 target_pid_to_str (lp->ptid));
3239 /* Make sure there is at least one thread running. */
3240 gdb_assert (iterate_over_lwps (ptid, running_callback, NULL));
3242 /* Discard the event. */
3246 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3247 an attempt to stop an LWP. */
3249 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP)
3251 if (debug_linux_nat)
3252 fprintf_unfiltered (gdb_stdlog,
3253 "LLW: Delayed SIGSTOP caught for %s.\n",
3254 target_pid_to_str (lp->ptid));
3256 /* This is a delayed SIGSTOP. */
3259 registers_changed ();
3261 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
3262 lp->step, TARGET_SIGNAL_0);
3263 if (debug_linux_nat)
3264 fprintf_unfiltered (gdb_stdlog,
3265 "LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
3267 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3268 target_pid_to_str (lp->ptid));
3271 gdb_assert (lp->resumed);
3273 /* Discard the event. */
3277 /* Make sure we don't report a SIGINT that we have already displayed
3278 for another thread. */
3279 if (lp->ignore_sigint
3280 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT)
3282 if (debug_linux_nat)
3283 fprintf_unfiltered (gdb_stdlog,
3284 "LLW: Delayed SIGINT caught for %s.\n",
3285 target_pid_to_str (lp->ptid));
3287 /* This is a delayed SIGINT. */
3288 lp->ignore_sigint = 0;
3290 registers_changed ();
3291 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
3292 lp->step, TARGET_SIGNAL_0);
3293 if (debug_linux_nat)
3294 fprintf_unfiltered (gdb_stdlog,
3295 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3297 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3298 target_pid_to_str (lp->ptid));
3301 gdb_assert (lp->resumed);
3303 /* Discard the event. */
3307 /* An interesting event. */
3309 lp->status = status;
3314 linux_nat_wait_1 (struct target_ops *ops,
3315 ptid_t ptid, struct target_waitstatus *ourstatus,
3318 static sigset_t prev_mask;
3319 struct lwp_info *lp = NULL;
3324 if (debug_linux_nat)
3325 fprintf_unfiltered (gdb_stdlog, "LLW: enter\n");
3327 /* The first time we get here after starting a new inferior, we may
3328 not have added it to the LWP list yet - this is the earliest
3329 moment at which we know its PID. */
3330 if (ptid_is_pid (inferior_ptid))
3332 /* Upgrade the main thread's ptid. */
3333 thread_change_ptid (inferior_ptid,
3334 BUILD_LWP (GET_PID (inferior_ptid),
3335 GET_PID (inferior_ptid)));
3337 lp = add_lwp (inferior_ptid);
3341 /* Make sure SIGCHLD is blocked. */
3342 block_child_signals (&prev_mask);
3344 if (ptid_equal (ptid, minus_one_ptid))
3346 else if (ptid_is_pid (ptid))
3347 /* A request to wait for a specific tgid. This is not possible
3348 with waitpid, so instead, we wait for any child, and leave
3349 children we're not interested in right now with a pending
3350 status to report later. */
3353 pid = GET_LWP (ptid);
3359 /* Make sure that of those LWPs we want to get an event from, there
3360 is at least one LWP that has been resumed. If there's none, just
3361 bail out. The core may just be flushing asynchronously all
3363 if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL)
3365 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3367 if (debug_linux_nat)
3368 fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n");
3370 restore_child_signals_mask (&prev_mask);
3371 return minus_one_ptid;
3374 /* First check if there is a LWP with a wait status pending. */
3377 /* Any LWP that's been resumed will do. */
3378 lp = iterate_over_lwps (ptid, status_callback, NULL);
3381 if (debug_linux_nat && lp->status)
3382 fprintf_unfiltered (gdb_stdlog,
3383 "LLW: Using pending wait status %s for %s.\n",
3384 status_to_str (lp->status),
3385 target_pid_to_str (lp->ptid));
3388 /* But if we don't find one, we'll have to wait, and check both
3389 cloned and uncloned processes. We start with the cloned
3391 options = __WCLONE | WNOHANG;
3393 else if (is_lwp (ptid))
3395 if (debug_linux_nat)
3396 fprintf_unfiltered (gdb_stdlog,
3397 "LLW: Waiting for specific LWP %s.\n",
3398 target_pid_to_str (ptid));
3400 /* We have a specific LWP to check. */
3401 lp = find_lwp_pid (ptid);
3404 if (debug_linux_nat && lp->status)
3405 fprintf_unfiltered (gdb_stdlog,
3406 "LLW: Using pending wait status %s for %s.\n",
3407 status_to_str (lp->status),
3408 target_pid_to_str (lp->ptid));
3410 /* If we have to wait, take into account whether PID is a cloned
3411 process or not. And we have to convert it to something that
3412 the layer beneath us can understand. */
3413 options = lp->cloned ? __WCLONE : 0;
3414 pid = GET_LWP (ptid);
3416 /* We check for lp->waitstatus in addition to lp->status,
3417 because we can have pending process exits recorded in
3418 lp->status and W_EXITCODE(0,0) == 0. We should probably have
3419 an additional lp->status_p flag. */
3420 if (lp->status == 0 && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE)
3424 if (lp && lp->signalled)
3426 /* A pending SIGSTOP may interfere with the normal stream of
3427 events. In a typical case where interference is a problem,
3428 we have a SIGSTOP signal pending for LWP A while
3429 single-stepping it, encounter an event in LWP B, and take the
3430 pending SIGSTOP while trying to stop LWP A. After processing
3431 the event in LWP B, LWP A is continued, and we'll never see
3432 the SIGTRAP associated with the last time we were
3433 single-stepping LWP A. */
3435 /* Resume the thread. It should halt immediately returning the
3437 registers_changed ();
3438 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
3439 lp->step, TARGET_SIGNAL_0);
3440 if (debug_linux_nat)
3441 fprintf_unfiltered (gdb_stdlog,
3442 "LLW: %s %s, 0, 0 (expect SIGSTOP)\n",
3443 lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3444 target_pid_to_str (lp->ptid));
3446 gdb_assert (lp->resumed);
3448 /* Catch the pending SIGSTOP. */
3449 status = lp->status;
3452 stop_wait_callback (lp, NULL);
3454 /* If the lp->status field isn't empty, we caught another signal
3455 while flushing the SIGSTOP. Return it back to the event
3456 queue of the LWP, as we already have an event to handle. */
3459 if (debug_linux_nat)
3460 fprintf_unfiltered (gdb_stdlog,
3461 "LLW: kill %s, %s\n",
3462 target_pid_to_str (lp->ptid),
3463 status_to_str (lp->status));
3464 kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (lp->status));
3467 lp->status = status;
3470 if (!target_can_async_p ())
3472 /* Causes SIGINT to be passed on to the attached process. */
3476 /* Translate generic target_wait options into waitpid options. */
3477 if (target_options & TARGET_WNOHANG)
3484 lwpid = my_waitpid (pid, &status, options);
3488 gdb_assert (pid == -1 || lwpid == pid);
3490 if (debug_linux_nat)
3492 fprintf_unfiltered (gdb_stdlog,
3493 "LLW: waitpid %ld received %s\n",
3494 (long) lwpid, status_to_str (status));
3497 lp = linux_nat_filter_event (lwpid, status, options);
3499 /* STATUS is now no longer valid, use LP->STATUS instead. */
3503 && ptid_is_pid (ptid)
3504 && ptid_get_pid (lp->ptid) != ptid_get_pid (ptid))
3506 gdb_assert (lp->resumed);
3508 if (debug_linux_nat)
3510 "LWP %ld got an event %06x, leaving pending.\n",
3511 ptid_get_lwp (lp->ptid), lp->status);
3513 if (WIFSTOPPED (lp->status))
3515 if (WSTOPSIG (lp->status) != SIGSTOP)
3517 /* Cancel breakpoint hits. The breakpoint may
3518 be removed before we fetch events from this
3519 process to report to the core. It is best
3520 not to assume the moribund breakpoints
3521 heuristic always handles these cases --- it
3522 could be too many events go through to the
3523 core before this one is handled. All-stop
3524 always cancels breakpoint hits in all
3527 && linux_nat_lp_status_is_event (lp)
3528 && cancel_breakpoint (lp))
3530 /* Throw away the SIGTRAP. */
3533 if (debug_linux_nat)
3535 "LLW: LWP %ld hit a breakpoint while"
3536 " waiting for another process;"
3538 ptid_get_lwp (lp->ptid));
3548 else if (WIFEXITED (lp->status) || WIFSIGNALED (lp->status))
3550 if (debug_linux_nat)
3552 "Process %ld exited while stopping LWPs\n",
3553 ptid_get_lwp (lp->ptid));
3555 /* This was the last lwp in the process. Since
3556 events are serialized to GDB core, and we can't
3557 report this one right now, but GDB core and the
3558 other target layers will want to be notified
3559 about the exit code/signal, leave the status
3560 pending for the next time we're able to report
3563 /* Prevent trying to stop this thread again. We'll
3564 never try to resume it because it has a pending
3568 /* Dead LWP's aren't expected to reported a pending
3572 /* Store the pending event in the waitstatus as
3573 well, because W_EXITCODE(0,0) == 0. */
3574 store_waitstatus (&lp->waitstatus, lp->status);
3588 /* waitpid did return something. Restart over. */
3589 options |= __WCLONE;
3597 /* Alternate between checking cloned and uncloned processes. */
3598 options ^= __WCLONE;
3600 /* And every time we have checked both:
3601 In async mode, return to event loop;
3602 In sync mode, suspend waiting for a SIGCHLD signal. */
3603 if (options & __WCLONE)
3605 if (target_options & TARGET_WNOHANG)
3607 /* No interesting event. */
3608 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3610 if (debug_linux_nat)
3611 fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
3613 restore_child_signals_mask (&prev_mask);
3614 return minus_one_ptid;
3617 sigsuspend (&suspend_mask);
3620 else if (target_options & TARGET_WNOHANG)
3622 /* No interesting event for PID yet. */
3623 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3625 if (debug_linux_nat)
3626 fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
3628 restore_child_signals_mask (&prev_mask);
3629 return minus_one_ptid;
3632 /* We shouldn't end up here unless we want to try again. */
3633 gdb_assert (lp == NULL);
3636 if (!target_can_async_p ())
3637 clear_sigint_trap ();
3641 status = lp->status;
3644 /* Don't report signals that GDB isn't interested in, such as
3645 signals that are neither printed nor stopped upon. Stopping all
3646 threads can be a bit time-consuming so if we want decent
3647 performance with heavily multi-threaded programs, especially when
3648 they're using a high frequency timer, we'd better avoid it if we
3651 if (WIFSTOPPED (status))
3653 enum target_signal signo = target_signal_from_host (WSTOPSIG (status));
3655 /* When using hardware single-step, we need to report every signal.
3656 Otherwise, signals in pass_mask may be short-circuited. */
3658 && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status)))
3660 /* FIMXE: kettenis/2001-06-06: Should we resume all threads
3661 here? It is not clear we should. GDB may not expect
3662 other threads to run. On the other hand, not resuming
3663 newly attached threads may cause an unwanted delay in
3664 getting them running. */
3665 registers_changed ();
3666 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
3668 if (debug_linux_nat)
3669 fprintf_unfiltered (gdb_stdlog,
3670 "LLW: %s %s, %s (preempt 'handle')\n",
3672 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3673 target_pid_to_str (lp->ptid),
3674 (signo != TARGET_SIGNAL_0
3675 ? strsignal (target_signal_to_host (signo))
3683 /* Only do the below in all-stop, as we currently use SIGINT
3684 to implement target_stop (see linux_nat_stop) in
3686 if (signo == TARGET_SIGNAL_INT && signal_pass_state (signo) == 0)
3688 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3689 forwarded to the entire process group, that is, all LWPs
3690 will receive it - unless they're using CLONE_THREAD to
3691 share signals. Since we only want to report it once, we
3692 mark it as ignored for all LWPs except this one. */
3693 iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid)),
3694 set_ignore_sigint, NULL);
3695 lp->ignore_sigint = 0;
3698 maybe_clear_ignore_sigint (lp);
3702 /* This LWP is stopped now. */
3705 if (debug_linux_nat)
3706 fprintf_unfiltered (gdb_stdlog, "LLW: Candidate event %s in %s.\n",
3707 status_to_str (status), target_pid_to_str (lp->ptid));
3711 /* Now stop all other LWP's ... */
3712 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
3714 /* ... and wait until all of them have reported back that
3715 they're no longer running. */
3716 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
3718 /* If we're not waiting for a specific LWP, choose an event LWP
3719 from among those that have had events. Giving equal priority
3720 to all LWPs that have had events helps prevent
3723 select_event_lwp (ptid, &lp, &status);
3725 /* Now that we've selected our final event LWP, cancel any
3726 breakpoints in other LWPs that have hit a GDB breakpoint.
3727 See the comment in cancel_breakpoints_callback to find out
3729 iterate_over_lwps (minus_one_ptid, cancel_breakpoints_callback, lp);
3731 /* In all-stop, from the core's perspective, all LWPs are now
3732 stopped until a new resume action is sent over. */
3733 iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL);
3738 if (linux_nat_status_is_event (status))
3740 if (debug_linux_nat)
3741 fprintf_unfiltered (gdb_stdlog,
3742 "LLW: trap ptid is %s.\n",
3743 target_pid_to_str (lp->ptid));
3746 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
3748 *ourstatus = lp->waitstatus;
3749 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
3752 store_waitstatus (ourstatus, status);
3754 if (debug_linux_nat)
3755 fprintf_unfiltered (gdb_stdlog, "LLW: exit\n");
3757 restore_child_signals_mask (&prev_mask);
3759 if (ourstatus->kind == TARGET_WAITKIND_EXITED
3760 || ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
3763 lp->core = linux_nat_core_of_thread_1 (lp->ptid);
3768 /* Resume LWPs that are currently stopped without any pending status
3769 to report, but are resumed from the core's perspective. */
3772 resume_stopped_resumed_lwps (struct lwp_info *lp, void *data)
3774 ptid_t *wait_ptid_p = data;
3779 && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE)
3781 gdb_assert (is_executing (lp->ptid));
3783 /* Don't bother if there's a breakpoint at PC that we'd hit
3784 immediately, and we're not waiting for this LWP. */
3785 if (!ptid_match (lp->ptid, *wait_ptid_p))
3787 struct regcache *regcache = get_thread_regcache (lp->ptid);
3788 CORE_ADDR pc = regcache_read_pc (regcache);
3790 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
3794 if (debug_linux_nat)
3795 fprintf_unfiltered (gdb_stdlog,
3796 "RSRL: resuming stopped-resumed LWP %s\n",
3797 target_pid_to_str (lp->ptid));
3799 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
3800 lp->step, TARGET_SIGNAL_0);
3802 memset (&lp->siginfo, 0, sizeof (lp->siginfo));
3803 lp->stopped_by_watchpoint = 0;
3810 linux_nat_wait (struct target_ops *ops,
3811 ptid_t ptid, struct target_waitstatus *ourstatus,
3816 if (debug_linux_nat)
3817 fprintf_unfiltered (gdb_stdlog,
3818 "linux_nat_wait: [%s]\n", target_pid_to_str (ptid));
3820 /* Flush the async file first. */
3821 if (target_can_async_p ())
3822 async_file_flush ();
3824 /* Resume LWPs that are currently stopped without any pending status
3825 to report, but are resumed from the core's perspective. LWPs get
3826 in this state if we find them stopping at a time we're not
3827 interested in reporting the event (target_wait on a
3828 specific_process, for example, see linux_nat_wait_1), and
3829 meanwhile the event became uninteresting. Don't bother resuming
3830 LWPs we're not going to wait for if they'd stop immediately. */
3832 iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid);
3834 event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options);
3836 /* If we requested any event, and something came out, assume there
3837 may be more. If we requested a specific lwp or process, also
3838 assume there may be more. */
3839 if (target_can_async_p ()
3840 && (ourstatus->kind != TARGET_WAITKIND_IGNORE
3841 || !ptid_equal (ptid, minus_one_ptid)))
3844 /* Get ready for the next event. */
3845 if (target_can_async_p ())
3846 target_async (inferior_event_handler, 0);
3852 kill_callback (struct lwp_info *lp, void *data)
3854 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3857 kill (GET_LWP (lp->ptid), SIGKILL);
3858 if (debug_linux_nat)
3859 fprintf_unfiltered (gdb_stdlog,
3860 "KC: kill (SIGKILL) %s, 0, 0 (%s)\n",
3861 target_pid_to_str (lp->ptid),
3862 errno ? safe_strerror (errno) : "OK");
3864 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3867 ptrace (PTRACE_KILL, GET_LWP (lp->ptid), 0, 0);
3868 if (debug_linux_nat)
3869 fprintf_unfiltered (gdb_stdlog,
3870 "KC: PTRACE_KILL %s, 0, 0 (%s)\n",
3871 target_pid_to_str (lp->ptid),
3872 errno ? safe_strerror (errno) : "OK");
3878 kill_wait_callback (struct lwp_info *lp, void *data)
3882 /* We must make sure that there are no pending events (delayed
3883 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3884 program doesn't interfere with any following debugging session. */
3886 /* For cloned processes we must check both with __WCLONE and
3887 without, since the exit status of a cloned process isn't reported
3893 pid = my_waitpid (GET_LWP (lp->ptid), NULL, __WCLONE);
3894 if (pid != (pid_t) -1)
3896 if (debug_linux_nat)
3897 fprintf_unfiltered (gdb_stdlog,
3898 "KWC: wait %s received unknown.\n",
3899 target_pid_to_str (lp->ptid));
3900 /* The Linux kernel sometimes fails to kill a thread
3901 completely after PTRACE_KILL; that goes from the stop
3902 point in do_fork out to the one in
3903 get_signal_to_deliever and waits again. So kill it
3905 kill_callback (lp, NULL);
3908 while (pid == GET_LWP (lp->ptid));
3910 gdb_assert (pid == -1 && errno == ECHILD);
3915 pid = my_waitpid (GET_LWP (lp->ptid), NULL, 0);
3916 if (pid != (pid_t) -1)
3918 if (debug_linux_nat)
3919 fprintf_unfiltered (gdb_stdlog,
3920 "KWC: wait %s received unk.\n",
3921 target_pid_to_str (lp->ptid));
3922 /* See the call to kill_callback above. */
3923 kill_callback (lp, NULL);
3926 while (pid == GET_LWP (lp->ptid));
3928 gdb_assert (pid == -1 && errno == ECHILD);
3933 linux_nat_kill (struct target_ops *ops)
3935 struct target_waitstatus last;
3939 /* If we're stopped while forking and we haven't followed yet,
3940 kill the other task. We need to do this first because the
3941 parent will be sleeping if this is a vfork. */
3943 get_last_target_status (&last_ptid, &last);
3945 if (last.kind == TARGET_WAITKIND_FORKED
3946 || last.kind == TARGET_WAITKIND_VFORKED)
3948 ptrace (PT_KILL, PIDGET (last.value.related_pid), 0, 0);
3952 if (forks_exist_p ())
3953 linux_fork_killall ();
3956 ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
3958 /* Stop all threads before killing them, since ptrace requires
3959 that the thread is stopped to sucessfully PTRACE_KILL. */
3960 iterate_over_lwps (ptid, stop_callback, NULL);
3961 /* ... and wait until all of them have reported back that
3962 they're no longer running. */
3963 iterate_over_lwps (ptid, stop_wait_callback, NULL);
3965 /* Kill all LWP's ... */
3966 iterate_over_lwps (ptid, kill_callback, NULL);
3968 /* ... and wait until we've flushed all events. */
3969 iterate_over_lwps (ptid, kill_wait_callback, NULL);
3972 target_mourn_inferior ();
3976 linux_nat_mourn_inferior (struct target_ops *ops)
3978 purge_lwp_list (ptid_get_pid (inferior_ptid));
3980 if (! forks_exist_p ())
3981 /* Normal case, no other forks available. */
3982 linux_ops->to_mourn_inferior (ops);
3984 /* Multi-fork case. The current inferior_ptid has exited, but
3985 there are other viable forks to debug. Delete the exiting
3986 one and context-switch to the first available. */
3987 linux_fork_mourn_inferior ();
3990 /* Convert a native/host siginfo object, into/from the siginfo in the
3991 layout of the inferiors' architecture. */
3994 siginfo_fixup (struct siginfo *siginfo, gdb_byte *inf_siginfo, int direction)
3998 if (linux_nat_siginfo_fixup != NULL)
3999 done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction);
4001 /* If there was no callback, or the callback didn't do anything,
4002 then just do a straight memcpy. */
4006 memcpy (siginfo, inf_siginfo, sizeof (struct siginfo));
4008 memcpy (inf_siginfo, siginfo, sizeof (struct siginfo));
4013 linux_xfer_siginfo (struct target_ops *ops, enum target_object object,
4014 const char *annex, gdb_byte *readbuf,
4015 const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
4018 struct siginfo siginfo;
4019 gdb_byte inf_siginfo[sizeof (struct siginfo)];
4021 gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO);
4022 gdb_assert (readbuf || writebuf);
4024 pid = GET_LWP (inferior_ptid);
4026 pid = GET_PID (inferior_ptid);
4028 if (offset > sizeof (siginfo))
4032 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
4036 /* When GDB is built as a 64-bit application, ptrace writes into
4037 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
4038 inferior with a 64-bit GDB should look the same as debugging it
4039 with a 32-bit GDB, we need to convert it. GDB core always sees
4040 the converted layout, so any read/write will have to be done
4042 siginfo_fixup (&siginfo, inf_siginfo, 0);
4044 if (offset + len > sizeof (siginfo))
4045 len = sizeof (siginfo) - offset;
4047 if (readbuf != NULL)
4048 memcpy (readbuf, inf_siginfo + offset, len);
4051 memcpy (inf_siginfo + offset, writebuf, len);
4053 /* Convert back to ptrace layout before flushing it out. */
4054 siginfo_fixup (&siginfo, inf_siginfo, 1);
4057 ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
4066 linux_nat_xfer_partial (struct target_ops *ops, enum target_object object,
4067 const char *annex, gdb_byte *readbuf,
4068 const gdb_byte *writebuf,
4069 ULONGEST offset, LONGEST len)
4071 struct cleanup *old_chain;
4074 if (object == TARGET_OBJECT_SIGNAL_INFO)
4075 return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf,
4078 /* The target is connected but no live inferior is selected. Pass
4079 this request down to a lower stratum (e.g., the executable
4081 if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid))
4084 old_chain = save_inferior_ptid ();
4086 if (is_lwp (inferior_ptid))
4087 inferior_ptid = pid_to_ptid (GET_LWP (inferior_ptid));
4089 xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf,
4092 do_cleanups (old_chain);
4097 linux_thread_alive (ptid_t ptid)
4101 gdb_assert (is_lwp (ptid));
4103 /* Send signal 0 instead of anything ptrace, because ptracing a
4104 running thread errors out claiming that the thread doesn't
4106 err = kill_lwp (GET_LWP (ptid), 0);
4108 if (debug_linux_nat)
4109 fprintf_unfiltered (gdb_stdlog,
4110 "LLTA: KILL(SIG0) %s (%s)\n",
4111 target_pid_to_str (ptid),
4112 err ? safe_strerror (tmp_errno) : "OK");
4121 linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid)
4123 return linux_thread_alive (ptid);
4127 linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid)
4129 static char buf[64];
4132 && (GET_PID (ptid) != GET_LWP (ptid)
4133 || num_lwps (GET_PID (ptid)) > 1))
4135 snprintf (buf, sizeof (buf), "LWP %ld", GET_LWP (ptid));
4139 return normal_pid_to_str (ptid);
4143 linux_nat_thread_name (struct thread_info *thr)
4145 int pid = ptid_get_pid (thr->ptid);
4146 long lwp = ptid_get_lwp (thr->ptid);
4147 #define FORMAT "/proc/%d/task/%ld/comm"
4148 char buf[sizeof (FORMAT) + 30];
4150 char *result = NULL;
4152 snprintf (buf, sizeof (buf), FORMAT, pid, lwp);
4153 comm_file = fopen (buf, "r");
4156 /* Not exported by the kernel, so we define it here. */
4158 static char line[COMM_LEN + 1];
4160 if (fgets (line, sizeof (line), comm_file))
4162 char *nl = strchr (line, '\n');
4179 /* Accepts an integer PID; Returns a string representing a file that
4180 can be opened to get the symbols for the child process. */
4183 linux_child_pid_to_exec_file (int pid)
4185 char *name1, *name2;
4187 name1 = xmalloc (MAXPATHLEN);
4188 name2 = xmalloc (MAXPATHLEN);
4189 make_cleanup (xfree, name1);
4190 make_cleanup (xfree, name2);
4191 memset (name2, 0, MAXPATHLEN);
4193 sprintf (name1, "/proc/%d/exe", pid);
4194 if (readlink (name1, name2, MAXPATHLEN) > 0)
4200 /* Service function for corefiles and info proc. */
4203 read_mapping (FILE *mapfile,
4208 char *device, long long *inode, char *filename)
4210 int ret = fscanf (mapfile, "%llx-%llx %s %llx %s %llx",
4211 addr, endaddr, permissions, offset, device, inode);
4214 if (ret > 0 && ret != EOF)
4216 /* Eat everything up to EOL for the filename. This will prevent
4217 weird filenames (such as one with embedded whitespace) from
4218 confusing this code. It also makes this code more robust in
4219 respect to annotations the kernel may add after the filename.
4221 Note the filename is used for informational purposes
4223 ret += fscanf (mapfile, "%[^\n]\n", filename);
4226 return (ret != 0 && ret != EOF);
4229 /* Fills the "to_find_memory_regions" target vector. Lists the memory
4230 regions in the inferior for a corefile. */
4233 linux_nat_find_memory_regions (find_memory_region_ftype func, void *obfd)
4235 int pid = PIDGET (inferior_ptid);
4236 char mapsfilename[MAXPATHLEN];
4238 long long addr, endaddr, size, offset, inode;
4239 char permissions[8], device[8], filename[MAXPATHLEN];
4240 int read, write, exec;
4241 struct cleanup *cleanup;
4243 /* Compose the filename for the /proc memory map, and open it. */
4244 sprintf (mapsfilename, "/proc/%d/maps", pid);
4245 if ((mapsfile = fopen (mapsfilename, "r")) == NULL)
4246 error (_("Could not open %s."), mapsfilename);
4247 cleanup = make_cleanup_fclose (mapsfile);
4250 fprintf_filtered (gdb_stdout,
4251 "Reading memory regions from %s\n", mapsfilename);
4253 /* Now iterate until end-of-file. */
4254 while (read_mapping (mapsfile, &addr, &endaddr, &permissions[0],
4255 &offset, &device[0], &inode, &filename[0]))
4257 size = endaddr - addr;
4259 /* Get the segment's permissions. */
4260 read = (strchr (permissions, 'r') != 0);
4261 write = (strchr (permissions, 'w') != 0);
4262 exec = (strchr (permissions, 'x') != 0);
4266 fprintf_filtered (gdb_stdout,
4267 "Save segment, %s bytes at %s (%c%c%c)",
4268 plongest (size), paddress (target_gdbarch, addr),
4270 write ? 'w' : ' ', exec ? 'x' : ' ');
4272 fprintf_filtered (gdb_stdout, " for %s", filename);
4273 fprintf_filtered (gdb_stdout, "\n");
4276 /* Invoke the callback function to create the corefile
4278 func (addr, size, read, write, exec, obfd);
4280 do_cleanups (cleanup);
4285 find_signalled_thread (struct thread_info *info, void *data)
4287 if (info->suspend.stop_signal != TARGET_SIGNAL_0
4288 && ptid_get_pid (info->ptid) == ptid_get_pid (inferior_ptid))
4294 static enum target_signal
4295 find_stop_signal (void)
4297 struct thread_info *info =
4298 iterate_over_threads (find_signalled_thread, NULL);
4301 return info->suspend.stop_signal;
4303 return TARGET_SIGNAL_0;
4306 /* Records the thread's register state for the corefile note
4310 linux_nat_do_thread_registers (bfd *obfd, ptid_t ptid,
4311 char *note_data, int *note_size,
4312 enum target_signal stop_signal)
4314 unsigned long lwp = ptid_get_lwp (ptid);
4315 struct gdbarch *gdbarch = target_gdbarch;
4316 struct regcache *regcache = get_thread_arch_regcache (ptid, gdbarch);
4317 const struct regset *regset;
4319 struct cleanup *old_chain;
4320 struct core_regset_section *sect_list;
4323 old_chain = save_inferior_ptid ();
4324 inferior_ptid = ptid;
4325 target_fetch_registers (regcache, -1);
4326 do_cleanups (old_chain);
4328 core_regset_p = gdbarch_regset_from_core_section_p (gdbarch);
4329 sect_list = gdbarch_core_regset_sections (gdbarch);
4331 /* The loop below uses the new struct core_regset_section, which stores
4332 the supported section names and sizes for the core file. Note that
4333 note PRSTATUS needs to be treated specially. But the other notes are
4334 structurally the same, so they can benefit from the new struct. */
4335 if (core_regset_p && sect_list != NULL)
4336 while (sect_list->sect_name != NULL)
4338 regset = gdbarch_regset_from_core_section (gdbarch,
4339 sect_list->sect_name,
4341 gdb_assert (regset && regset->collect_regset);
4342 gdb_regset = xmalloc (sect_list->size);
4343 regset->collect_regset (regset, regcache, -1,
4344 gdb_regset, sect_list->size);
4346 if (strcmp (sect_list->sect_name, ".reg") == 0)
4347 note_data = (char *) elfcore_write_prstatus
4348 (obfd, note_data, note_size,
4349 lwp, target_signal_to_host (stop_signal),
4352 note_data = (char *) elfcore_write_register_note
4353 (obfd, note_data, note_size,
4354 sect_list->sect_name, gdb_regset,
4360 /* For architectures that does not have the struct core_regset_section
4361 implemented, we use the old method. When all the architectures have
4362 the new support, the code below should be deleted. */
4365 gdb_gregset_t gregs;
4366 gdb_fpregset_t fpregs;
4369 && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg",
4371 != NULL && regset->collect_regset != NULL)
4372 regset->collect_regset (regset, regcache, -1,
4373 &gregs, sizeof (gregs));
4375 fill_gregset (regcache, &gregs, -1);
4377 note_data = (char *) elfcore_write_prstatus
4378 (obfd, note_data, note_size, lwp, target_signal_to_host (stop_signal),
4382 && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg2",
4384 != NULL && regset->collect_regset != NULL)
4385 regset->collect_regset (regset, regcache, -1,
4386 &fpregs, sizeof (fpregs));
4388 fill_fpregset (regcache, &fpregs, -1);
4390 note_data = (char *) elfcore_write_prfpreg (obfd,
4393 &fpregs, sizeof (fpregs));
4399 struct linux_nat_corefile_thread_data
4405 enum target_signal stop_signal;
4408 /* Called by gdbthread.c once per thread. Records the thread's
4409 register state for the corefile note section. */
4412 linux_nat_corefile_thread_callback (struct lwp_info *ti, void *data)
4414 struct linux_nat_corefile_thread_data *args = data;
4416 args->note_data = linux_nat_do_thread_registers (args->obfd,
4426 /* Enumerate spufs IDs for process PID. */
4429 iterate_over_spus (int pid, void (*callback) (void *, int), void *data)
4433 struct dirent *entry;
4435 xsnprintf (path, sizeof path, "/proc/%d/fd", pid);
4436 dir = opendir (path);
4441 while ((entry = readdir (dir)) != NULL)
4447 fd = atoi (entry->d_name);
4451 xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd);
4452 if (stat (path, &st) != 0)
4454 if (!S_ISDIR (st.st_mode))
4457 if (statfs (path, &stfs) != 0)
4459 if (stfs.f_type != SPUFS_MAGIC)
4462 callback (data, fd);
4468 /* Generate corefile notes for SPU contexts. */
4470 struct linux_spu_corefile_data
4478 linux_spu_corefile_callback (void *data, int fd)
4480 struct linux_spu_corefile_data *args = data;
4483 static const char *spu_files[] =
4505 for (i = 0; i < sizeof (spu_files) / sizeof (spu_files[0]); i++)
4507 char annex[32], note_name[32];
4511 xsnprintf (annex, sizeof annex, "%d/%s", fd, spu_files[i]);
4512 spu_len = target_read_alloc (¤t_target, TARGET_OBJECT_SPU,
4516 xsnprintf (note_name, sizeof note_name, "SPU/%s", annex);
4517 args->note_data = elfcore_write_note (args->obfd, args->note_data,
4518 args->note_size, note_name,
4519 NT_SPU, spu_data, spu_len);
4526 linux_spu_make_corefile_notes (bfd *obfd, char *note_data, int *note_size)
4528 struct linux_spu_corefile_data args;
4531 args.note_data = note_data;
4532 args.note_size = note_size;
4534 iterate_over_spus (PIDGET (inferior_ptid),
4535 linux_spu_corefile_callback, &args);
4537 return args.note_data;
4540 /* Fills the "to_make_corefile_note" target vector. Builds the note
4541 section for a corefile, and returns it in a malloc buffer. */
4544 linux_nat_make_corefile_notes (bfd *obfd, int *note_size)
4546 struct linux_nat_corefile_thread_data thread_args;
4547 /* The variable size must be >= sizeof (prpsinfo_t.pr_fname). */
4548 char fname[16] = { '\0' };
4549 /* The variable size must be >= sizeof (prpsinfo_t.pr_psargs). */
4550 char psargs[80] = { '\0' };
4551 char *note_data = NULL;
4552 ptid_t filter = pid_to_ptid (ptid_get_pid (inferior_ptid));
4556 if (get_exec_file (0))
4558 strncpy (fname, lbasename (get_exec_file (0)), sizeof (fname));
4559 strncpy (psargs, get_exec_file (0), sizeof (psargs));
4560 if (get_inferior_args ())
4563 char *psargs_end = psargs + sizeof (psargs);
4565 /* linux_elfcore_write_prpsinfo () handles zero unterminated
4567 string_end = memchr (psargs, 0, sizeof (psargs));
4568 if (string_end != NULL)
4570 *string_end++ = ' ';
4571 strncpy (string_end, get_inferior_args (),
4572 psargs_end - string_end);
4575 note_data = (char *) elfcore_write_prpsinfo (obfd,
4577 note_size, fname, psargs);
4580 /* Dump information for threads. */
4581 thread_args.obfd = obfd;
4582 thread_args.note_data = note_data;
4583 thread_args.note_size = note_size;
4584 thread_args.num_notes = 0;
4585 thread_args.stop_signal = find_stop_signal ();
4586 iterate_over_lwps (filter, linux_nat_corefile_thread_callback, &thread_args);
4587 gdb_assert (thread_args.num_notes != 0);
4588 note_data = thread_args.note_data;
4590 auxv_len = target_read_alloc (¤t_target, TARGET_OBJECT_AUXV,
4594 note_data = elfcore_write_note (obfd, note_data, note_size,
4595 "CORE", NT_AUXV, auxv, auxv_len);
4599 note_data = linux_spu_make_corefile_notes (obfd, note_data, note_size);
4601 make_cleanup (xfree, note_data);
4605 /* Implement the "info proc" command. */
4608 linux_nat_info_proc_cmd (char *args, int from_tty)
4610 /* A long is used for pid instead of an int to avoid a loss of precision
4611 compiler warning from the output of strtoul. */
4612 long pid = PIDGET (inferior_ptid);
4615 char buffer[MAXPATHLEN];
4616 char fname1[MAXPATHLEN], fname2[MAXPATHLEN];
4628 /* Break up 'args' into an argv array. */
4629 argv = gdb_buildargv (args);
4630 make_cleanup_freeargv (argv);
4632 while (argv != NULL && *argv != NULL)
4634 if (isdigit (argv[0][0]))
4636 pid = strtoul (argv[0], NULL, 10);
4638 else if (strncmp (argv[0], "mappings", strlen (argv[0])) == 0)
4642 else if (strcmp (argv[0], "status") == 0)
4646 else if (strcmp (argv[0], "stat") == 0)
4650 else if (strcmp (argv[0], "cmd") == 0)
4654 else if (strncmp (argv[0], "exe", strlen (argv[0])) == 0)
4658 else if (strcmp (argv[0], "cwd") == 0)
4662 else if (strncmp (argv[0], "all", strlen (argv[0])) == 0)
4668 /* [...] (future options here). */
4673 error (_("No current process: you must name one."));
4675 sprintf (fname1, "/proc/%ld", pid);
4676 if (stat (fname1, &dummy) != 0)
4677 error (_("No /proc directory: '%s'"), fname1);
4679 printf_filtered (_("process %ld\n"), pid);
4680 if (cmdline_f || all)
4682 sprintf (fname1, "/proc/%ld/cmdline", pid);
4683 if ((procfile = fopen (fname1, "r")) != NULL)
4685 struct cleanup *cleanup = make_cleanup_fclose (procfile);
4687 if (fgets (buffer, sizeof (buffer), procfile))
4688 printf_filtered ("cmdline = '%s'\n", buffer);
4690 warning (_("unable to read '%s'"), fname1);
4691 do_cleanups (cleanup);
4694 warning (_("unable to open /proc file '%s'"), fname1);
4698 sprintf (fname1, "/proc/%ld/cwd", pid);
4699 memset (fname2, 0, sizeof (fname2));
4700 if (readlink (fname1, fname2, sizeof (fname2)) > 0)
4701 printf_filtered ("cwd = '%s'\n", fname2);
4703 warning (_("unable to read link '%s'"), fname1);
4707 sprintf (fname1, "/proc/%ld/exe", pid);
4708 memset (fname2, 0, sizeof (fname2));
4709 if (readlink (fname1, fname2, sizeof (fname2)) > 0)
4710 printf_filtered ("exe = '%s'\n", fname2);
4712 warning (_("unable to read link '%s'"), fname1);
4714 if (mappings_f || all)
4716 sprintf (fname1, "/proc/%ld/maps", pid);
4717 if ((procfile = fopen (fname1, "r")) != NULL)
4719 long long addr, endaddr, size, offset, inode;
4720 char permissions[8], device[8], filename[MAXPATHLEN];
4721 struct cleanup *cleanup;
4723 cleanup = make_cleanup_fclose (procfile);
4724 printf_filtered (_("Mapped address spaces:\n\n"));
4725 if (gdbarch_addr_bit (target_gdbarch) == 32)
4727 printf_filtered ("\t%10s %10s %10s %10s %7s\n",
4730 " Size", " Offset", "objfile");
4734 printf_filtered (" %18s %18s %10s %10s %7s\n",
4737 " Size", " Offset", "objfile");
4740 while (read_mapping (procfile, &addr, &endaddr, &permissions[0],
4741 &offset, &device[0], &inode, &filename[0]))
4743 size = endaddr - addr;
4745 /* FIXME: carlton/2003-08-27: Maybe the printf_filtered
4746 calls here (and possibly above) should be abstracted
4747 out into their own functions? Andrew suggests using
4748 a generic local_address_string instead to print out
4749 the addresses; that makes sense to me, too. */
4751 if (gdbarch_addr_bit (target_gdbarch) == 32)
4753 printf_filtered ("\t%#10lx %#10lx %#10x %#10x %7s\n",
4754 (unsigned long) addr, /* FIXME: pr_addr */
4755 (unsigned long) endaddr,
4757 (unsigned int) offset,
4758 filename[0] ? filename : "");
4762 printf_filtered (" %#18lx %#18lx %#10x %#10x %7s\n",
4763 (unsigned long) addr, /* FIXME: pr_addr */
4764 (unsigned long) endaddr,
4766 (unsigned int) offset,
4767 filename[0] ? filename : "");
4771 do_cleanups (cleanup);
4774 warning (_("unable to open /proc file '%s'"), fname1);
4776 if (status_f || all)
4778 sprintf (fname1, "/proc/%ld/status", pid);
4779 if ((procfile = fopen (fname1, "r")) != NULL)
4781 struct cleanup *cleanup = make_cleanup_fclose (procfile);
4783 while (fgets (buffer, sizeof (buffer), procfile) != NULL)
4784 puts_filtered (buffer);
4785 do_cleanups (cleanup);
4788 warning (_("unable to open /proc file '%s'"), fname1);
4792 sprintf (fname1, "/proc/%ld/stat", pid);
4793 if ((procfile = fopen (fname1, "r")) != NULL)
4798 struct cleanup *cleanup = make_cleanup_fclose (procfile);
4800 if (fscanf (procfile, "%d ", &itmp) > 0)
4801 printf_filtered (_("Process: %d\n"), itmp);
4802 if (fscanf (procfile, "(%[^)]) ", &buffer[0]) > 0)
4803 printf_filtered (_("Exec file: %s\n"), buffer);
4804 if (fscanf (procfile, "%c ", &ctmp) > 0)
4805 printf_filtered (_("State: %c\n"), ctmp);
4806 if (fscanf (procfile, "%d ", &itmp) > 0)
4807 printf_filtered (_("Parent process: %d\n"), itmp);
4808 if (fscanf (procfile, "%d ", &itmp) > 0)
4809 printf_filtered (_("Process group: %d\n"), itmp);
4810 if (fscanf (procfile, "%d ", &itmp) > 0)
4811 printf_filtered (_("Session id: %d\n"), itmp);
4812 if (fscanf (procfile, "%d ", &itmp) > 0)
4813 printf_filtered (_("TTY: %d\n"), itmp);
4814 if (fscanf (procfile, "%d ", &itmp) > 0)
4815 printf_filtered (_("TTY owner process group: %d\n"), itmp);
4816 if (fscanf (procfile, "%lu ", <mp) > 0)
4817 printf_filtered (_("Flags: 0x%lx\n"), ltmp);
4818 if (fscanf (procfile, "%lu ", <mp) > 0)
4819 printf_filtered (_("Minor faults (no memory page): %lu\n"),
4820 (unsigned long) ltmp);
4821 if (fscanf (procfile, "%lu ", <mp) > 0)
4822 printf_filtered (_("Minor faults, children: %lu\n"),
4823 (unsigned long) ltmp);
4824 if (fscanf (procfile, "%lu ", <mp) > 0)
4825 printf_filtered (_("Major faults (memory page faults): %lu\n"),
4826 (unsigned long) ltmp);
4827 if (fscanf (procfile, "%lu ", <mp) > 0)
4828 printf_filtered (_("Major faults, children: %lu\n"),
4829 (unsigned long) ltmp);
4830 if (fscanf (procfile, "%ld ", <mp) > 0)
4831 printf_filtered (_("utime: %ld\n"), ltmp);
4832 if (fscanf (procfile, "%ld ", <mp) > 0)
4833 printf_filtered (_("stime: %ld\n"), ltmp);
4834 if (fscanf (procfile, "%ld ", <mp) > 0)
4835 printf_filtered (_("utime, children: %ld\n"), ltmp);
4836 if (fscanf (procfile, "%ld ", <mp) > 0)
4837 printf_filtered (_("stime, children: %ld\n"), ltmp);
4838 if (fscanf (procfile, "%ld ", <mp) > 0)
4839 printf_filtered (_("jiffies remaining in current "
4840 "time slice: %ld\n"), ltmp);
4841 if (fscanf (procfile, "%ld ", <mp) > 0)
4842 printf_filtered (_("'nice' value: %ld\n"), ltmp);
4843 if (fscanf (procfile, "%lu ", <mp) > 0)
4844 printf_filtered (_("jiffies until next timeout: %lu\n"),
4845 (unsigned long) ltmp);
4846 if (fscanf (procfile, "%lu ", <mp) > 0)
4847 printf_filtered (_("jiffies until next SIGALRM: %lu\n"),
4848 (unsigned long) ltmp);
4849 if (fscanf (procfile, "%ld ", <mp) > 0)
4850 printf_filtered (_("start time (jiffies since "
4851 "system boot): %ld\n"), ltmp);
4852 if (fscanf (procfile, "%lu ", <mp) > 0)
4853 printf_filtered (_("Virtual memory size: %lu\n"),
4854 (unsigned long) ltmp);
4855 if (fscanf (procfile, "%lu ", <mp) > 0)
4856 printf_filtered (_("Resident set size: %lu\n"),
4857 (unsigned long) ltmp);
4858 if (fscanf (procfile, "%lu ", <mp) > 0)
4859 printf_filtered (_("rlim: %lu\n"), (unsigned long) ltmp);
4860 if (fscanf (procfile, "%lu ", <mp) > 0)
4861 printf_filtered (_("Start of text: 0x%lx\n"), ltmp);
4862 if (fscanf (procfile, "%lu ", <mp) > 0)
4863 printf_filtered (_("End of text: 0x%lx\n"), ltmp);
4864 if (fscanf (procfile, "%lu ", <mp) > 0)
4865 printf_filtered (_("Start of stack: 0x%lx\n"), ltmp);
4866 #if 0 /* Don't know how architecture-dependent the rest is...
4867 Anyway the signal bitmap info is available from "status". */
4868 if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */
4869 printf_filtered (_("Kernel stack pointer: 0x%lx\n"), ltmp);
4870 if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */
4871 printf_filtered (_("Kernel instr pointer: 0x%lx\n"), ltmp);
4872 if (fscanf (procfile, "%ld ", <mp) > 0)
4873 printf_filtered (_("Pending signals bitmap: 0x%lx\n"), ltmp);
4874 if (fscanf (procfile, "%ld ", <mp) > 0)
4875 printf_filtered (_("Blocked signals bitmap: 0x%lx\n"), ltmp);
4876 if (fscanf (procfile, "%ld ", <mp) > 0)
4877 printf_filtered (_("Ignored signals bitmap: 0x%lx\n"), ltmp);
4878 if (fscanf (procfile, "%ld ", <mp) > 0)
4879 printf_filtered (_("Catched signals bitmap: 0x%lx\n"), ltmp);
4880 if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */
4881 printf_filtered (_("wchan (system call): 0x%lx\n"), ltmp);
4883 do_cleanups (cleanup);
4886 warning (_("unable to open /proc file '%s'"), fname1);
4890 /* Implement the to_xfer_partial interface for memory reads using the /proc
4891 filesystem. Because we can use a single read() call for /proc, this
4892 can be much more efficient than banging away at PTRACE_PEEKTEXT,
4893 but it doesn't support writes. */
4896 linux_proc_xfer_partial (struct target_ops *ops, enum target_object object,
4897 const char *annex, gdb_byte *readbuf,
4898 const gdb_byte *writebuf,
4899 ULONGEST offset, LONGEST len)
4905 if (object != TARGET_OBJECT_MEMORY || !readbuf)
4908 /* Don't bother for one word. */
4909 if (len < 3 * sizeof (long))
4912 /* We could keep this file open and cache it - possibly one per
4913 thread. That requires some juggling, but is even faster. */
4914 sprintf (filename, "/proc/%d/mem", PIDGET (inferior_ptid));
4915 fd = open (filename, O_RDONLY | O_LARGEFILE);
4919 /* If pread64 is available, use it. It's faster if the kernel
4920 supports it (only one syscall), and it's 64-bit safe even on
4921 32-bit platforms (for instance, SPARC debugging a SPARC64
4924 if (pread64 (fd, readbuf, len, offset) != len)
4926 if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len)
4937 /* Enumerate spufs IDs for process PID. */
4939 spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, LONGEST len)
4941 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
4943 LONGEST written = 0;
4946 struct dirent *entry;
4948 xsnprintf (path, sizeof path, "/proc/%d/fd", pid);
4949 dir = opendir (path);
4954 while ((entry = readdir (dir)) != NULL)
4960 fd = atoi (entry->d_name);
4964 xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd);
4965 if (stat (path, &st) != 0)
4967 if (!S_ISDIR (st.st_mode))
4970 if (statfs (path, &stfs) != 0)
4972 if (stfs.f_type != SPUFS_MAGIC)
4975 if (pos >= offset && pos + 4 <= offset + len)
4977 store_unsigned_integer (buf + pos - offset, 4, byte_order, fd);
4987 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4988 object type, using the /proc file system. */
4990 linux_proc_xfer_spu (struct target_ops *ops, enum target_object object,
4991 const char *annex, gdb_byte *readbuf,
4992 const gdb_byte *writebuf,
4993 ULONGEST offset, LONGEST len)
4998 int pid = PIDGET (inferior_ptid);
5005 return spu_enumerate_spu_ids (pid, readbuf, offset, len);
5008 xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex);
5009 fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
5014 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
5021 ret = write (fd, writebuf, (size_t) len);
5023 ret = read (fd, readbuf, (size_t) len);
5030 /* Parse LINE as a signal set and add its set bits to SIGS. */
5033 add_line_to_sigset (const char *line, sigset_t *sigs)
5035 int len = strlen (line) - 1;
5039 if (line[len] != '\n')
5040 error (_("Could not parse signal set: %s"), line);
5048 if (*p >= '0' && *p <= '9')
5050 else if (*p >= 'a' && *p <= 'f')
5051 digit = *p - 'a' + 10;
5053 error (_("Could not parse signal set: %s"), line);
5058 sigaddset (sigs, signum + 1);
5060 sigaddset (sigs, signum + 2);
5062 sigaddset (sigs, signum + 3);
5064 sigaddset (sigs, signum + 4);
5070 /* Find process PID's pending signals from /proc/pid/status and set
5074 linux_proc_pending_signals (int pid, sigset_t *pending,
5075 sigset_t *blocked, sigset_t *ignored)
5078 char buffer[MAXPATHLEN], fname[MAXPATHLEN];
5079 struct cleanup *cleanup;
5081 sigemptyset (pending);
5082 sigemptyset (blocked);
5083 sigemptyset (ignored);
5084 sprintf (fname, "/proc/%d/status", pid);
5085 procfile = fopen (fname, "r");
5086 if (procfile == NULL)
5087 error (_("Could not open %s"), fname);
5088 cleanup = make_cleanup_fclose (procfile);
5090 while (fgets (buffer, MAXPATHLEN, procfile) != NULL)
5092 /* Normal queued signals are on the SigPnd line in the status
5093 file. However, 2.6 kernels also have a "shared" pending
5094 queue for delivering signals to a thread group, so check for
5097 Unfortunately some Red Hat kernels include the shared pending
5098 queue but not the ShdPnd status field. */
5100 if (strncmp (buffer, "SigPnd:\t", 8) == 0)
5101 add_line_to_sigset (buffer + 8, pending);
5102 else if (strncmp (buffer, "ShdPnd:\t", 8) == 0)
5103 add_line_to_sigset (buffer + 8, pending);
5104 else if (strncmp (buffer, "SigBlk:\t", 8) == 0)
5105 add_line_to_sigset (buffer + 8, blocked);
5106 else if (strncmp (buffer, "SigIgn:\t", 8) == 0)
5107 add_line_to_sigset (buffer + 8, ignored);
5110 do_cleanups (cleanup);
5114 linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object,
5115 const char *annex, gdb_byte *readbuf,
5116 const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
5118 gdb_assert (object == TARGET_OBJECT_OSDATA);
5120 return linux_common_xfer_osdata (annex, readbuf, offset, len);
5124 linux_xfer_partial (struct target_ops *ops, enum target_object object,
5125 const char *annex, gdb_byte *readbuf,
5126 const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
5130 if (object == TARGET_OBJECT_AUXV)
5131 return memory_xfer_auxv (ops, object, annex, readbuf, writebuf,
5134 if (object == TARGET_OBJECT_OSDATA)
5135 return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf,
5138 if (object == TARGET_OBJECT_SPU)
5139 return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf,
5142 /* GDB calculates all the addresses in possibly larget width of the address.
5143 Address width needs to be masked before its final use - either by
5144 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
5146 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
5148 if (object == TARGET_OBJECT_MEMORY)
5150 int addr_bit = gdbarch_addr_bit (target_gdbarch);
5152 if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT))
5153 offset &= ((ULONGEST) 1 << addr_bit) - 1;
5156 xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf,
5161 return super_xfer_partial (ops, object, annex, readbuf, writebuf,
5165 /* Create a prototype generic GNU/Linux target. The client can override
5166 it with local methods. */
5169 linux_target_install_ops (struct target_ops *t)
5171 t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint;
5172 t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint;
5173 t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint;
5174 t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint;
5175 t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint;
5176 t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint;
5177 t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint;
5178 t->to_pid_to_exec_file = linux_child_pid_to_exec_file;
5179 t->to_post_startup_inferior = linux_child_post_startup_inferior;
5180 t->to_post_attach = linux_child_post_attach;
5181 t->to_follow_fork = linux_child_follow_fork;
5182 t->to_find_memory_regions = linux_nat_find_memory_regions;
5183 t->to_make_corefile_notes = linux_nat_make_corefile_notes;
5185 super_xfer_partial = t->to_xfer_partial;
5186 t->to_xfer_partial = linux_xfer_partial;
5192 struct target_ops *t;
5194 t = inf_ptrace_target ();
5195 linux_target_install_ops (t);
5201 linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int))
5203 struct target_ops *t;
5205 t = inf_ptrace_trad_target (register_u_offset);
5206 linux_target_install_ops (t);
5211 /* target_is_async_p implementation. */
5214 linux_nat_is_async_p (void)
5216 /* NOTE: palves 2008-03-21: We're only async when the user requests
5217 it explicitly with the "set target-async" command.
5218 Someday, linux will always be async. */
5219 return target_async_permitted;
5222 /* target_can_async_p implementation. */
5225 linux_nat_can_async_p (void)
5227 /* NOTE: palves 2008-03-21: We're only async when the user requests
5228 it explicitly with the "set target-async" command.
5229 Someday, linux will always be async. */
5230 return target_async_permitted;
5234 linux_nat_supports_non_stop (void)
5239 /* True if we want to support multi-process. To be removed when GDB
5240 supports multi-exec. */
5242 int linux_multi_process = 1;
5245 linux_nat_supports_multi_process (void)
5247 return linux_multi_process;
5250 static int async_terminal_is_ours = 1;
5252 /* target_terminal_inferior implementation. */
5255 linux_nat_terminal_inferior (void)
5257 if (!target_is_async_p ())
5259 /* Async mode is disabled. */
5260 terminal_inferior ();
5264 terminal_inferior ();
5266 /* Calls to target_terminal_*() are meant to be idempotent. */
5267 if (!async_terminal_is_ours)
5270 delete_file_handler (input_fd);
5271 async_terminal_is_ours = 0;
5275 /* target_terminal_ours implementation. */
5278 linux_nat_terminal_ours (void)
5280 if (!target_is_async_p ())
5282 /* Async mode is disabled. */
5287 /* GDB should never give the terminal to the inferior if the
5288 inferior is running in the background (run&, continue&, etc.),
5289 but claiming it sure should. */
5292 if (async_terminal_is_ours)
5295 clear_sigint_trap ();
5296 add_file_handler (input_fd, stdin_event_handler, 0);
5297 async_terminal_is_ours = 1;
5300 static void (*async_client_callback) (enum inferior_event_type event_type,
5302 static void *async_client_context;
5304 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
5305 so we notice when any child changes state, and notify the
5306 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
5307 above to wait for the arrival of a SIGCHLD. */
5310 sigchld_handler (int signo)
5312 int old_errno = errno;
5314 if (debug_linux_nat)
5315 ui_file_write_async_safe (gdb_stdlog,
5316 "sigchld\n", sizeof ("sigchld\n") - 1);
5318 if (signo == SIGCHLD
5319 && linux_nat_event_pipe[0] != -1)
5320 async_file_mark (); /* Let the event loop know that there are
5321 events to handle. */
5326 /* Callback registered with the target events file descriptor. */
5329 handle_target_event (int error, gdb_client_data client_data)
5331 (*async_client_callback) (INF_REG_EVENT, async_client_context);
5334 /* Create/destroy the target events pipe. Returns previous state. */
5337 linux_async_pipe (int enable)
5339 int previous = (linux_nat_event_pipe[0] != -1);
5341 if (previous != enable)
5345 block_child_signals (&prev_mask);
5349 if (pipe (linux_nat_event_pipe) == -1)
5350 internal_error (__FILE__, __LINE__,
5351 "creating event pipe failed.");
5353 fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK);
5354 fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK);
5358 close (linux_nat_event_pipe[0]);
5359 close (linux_nat_event_pipe[1]);
5360 linux_nat_event_pipe[0] = -1;
5361 linux_nat_event_pipe[1] = -1;
5364 restore_child_signals_mask (&prev_mask);
5370 /* target_async implementation. */
5373 linux_nat_async (void (*callback) (enum inferior_event_type event_type,
5374 void *context), void *context)
5376 if (callback != NULL)
5378 async_client_callback = callback;
5379 async_client_context = context;
5380 if (!linux_async_pipe (1))
5382 add_file_handler (linux_nat_event_pipe[0],
5383 handle_target_event, NULL);
5384 /* There may be pending events to handle. Tell the event loop
5391 async_client_callback = callback;
5392 async_client_context = context;
5393 delete_file_handler (linux_nat_event_pipe[0]);
5394 linux_async_pipe (0);
5399 /* Stop an LWP, and push a TARGET_SIGNAL_0 stop status if no other
5403 linux_nat_stop_lwp (struct lwp_info *lwp, void *data)
5407 ptid_t ptid = lwp->ptid;
5409 if (debug_linux_nat)
5410 fprintf_unfiltered (gdb_stdlog,
5411 "LNSL: running -> suspending %s\n",
5412 target_pid_to_str (lwp->ptid));
5415 stop_callback (lwp, NULL);
5416 stop_wait_callback (lwp, NULL);
5418 /* If the lwp exits while we try to stop it, there's nothing
5420 lwp = find_lwp_pid (ptid);
5424 /* If we didn't collect any signal other than SIGSTOP while
5425 stopping the LWP, push a SIGNAL_0 event. In either case, the
5426 event-loop will end up calling target_wait which will collect
5428 if (lwp->status == 0)
5429 lwp->status = W_STOPCODE (0);
5434 /* Already known to be stopped; do nothing. */
5436 if (debug_linux_nat)
5438 if (find_thread_ptid (lwp->ptid)->stop_requested)
5439 fprintf_unfiltered (gdb_stdlog,
5440 "LNSL: already stopped/stop_requested %s\n",
5441 target_pid_to_str (lwp->ptid));
5443 fprintf_unfiltered (gdb_stdlog,
5444 "LNSL: already stopped/no "
5445 "stop_requested yet %s\n",
5446 target_pid_to_str (lwp->ptid));
5453 linux_nat_stop (ptid_t ptid)
5456 iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL);
5458 linux_ops->to_stop (ptid);
5462 linux_nat_close (int quitting)
5464 /* Unregister from the event loop. */
5465 if (target_is_async_p ())
5466 target_async (NULL, 0);
5468 if (linux_ops->to_close)
5469 linux_ops->to_close (quitting);
5472 /* When requests are passed down from the linux-nat layer to the
5473 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
5474 used. The address space pointer is stored in the inferior object,
5475 but the common code that is passed such ptid can't tell whether
5476 lwpid is a "main" process id or not (it assumes so). We reverse
5477 look up the "main" process id from the lwp here. */
5479 struct address_space *
5480 linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid)
5482 struct lwp_info *lwp;
5483 struct inferior *inf;
5486 pid = GET_LWP (ptid);
5487 if (GET_LWP (ptid) == 0)
5489 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
5491 lwp = find_lwp_pid (ptid);
5492 pid = GET_PID (lwp->ptid);
5496 /* A (pid,lwpid,0) ptid. */
5497 pid = GET_PID (ptid);
5500 inf = find_inferior_pid (pid);
5501 gdb_assert (inf != NULL);
5506 linux_nat_core_of_thread_1 (ptid_t ptid)
5508 struct cleanup *back_to;
5511 char *content = NULL;
5514 int content_read = 0;
5518 filename = xstrprintf ("/proc/%d/task/%ld/stat",
5519 GET_PID (ptid), GET_LWP (ptid));
5520 back_to = make_cleanup (xfree, filename);
5522 f = fopen (filename, "r");
5525 do_cleanups (back_to);
5529 make_cleanup_fclose (f);
5535 content = xrealloc (content, content_read + 1024);
5536 n = fread (content + content_read, 1, 1024, f);
5540 content[content_read] = '\0';
5545 make_cleanup (xfree, content);
5547 p = strchr (content, '(');
5551 p = strchr (p, ')');
5555 /* If the first field after program name has index 0, then core number is
5556 the field with index 36. There's no constant for that anywhere. */
5558 p = strtok_r (p, " ", &ts);
5559 for (i = 0; p != NULL && i != 36; ++i)
5560 p = strtok_r (NULL, " ", &ts);
5562 if (p == NULL || sscanf (p, "%d", &core) == 0)
5565 do_cleanups (back_to);
5570 /* Return the cached value of the processor core for thread PTID. */
5573 linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid)
5575 struct lwp_info *info = find_lwp_pid (ptid);
5583 linux_nat_add_target (struct target_ops *t)
5585 /* Save the provided single-threaded target. We save this in a separate
5586 variable because another target we've inherited from (e.g. inf-ptrace)
5587 may have saved a pointer to T; we want to use it for the final
5588 process stratum target. */
5589 linux_ops_saved = *t;
5590 linux_ops = &linux_ops_saved;
5592 /* Override some methods for multithreading. */
5593 t->to_create_inferior = linux_nat_create_inferior;
5594 t->to_attach = linux_nat_attach;
5595 t->to_detach = linux_nat_detach;
5596 t->to_resume = linux_nat_resume;
5597 t->to_wait = linux_nat_wait;
5598 t->to_pass_signals = linux_nat_pass_signals;
5599 t->to_xfer_partial = linux_nat_xfer_partial;
5600 t->to_kill = linux_nat_kill;
5601 t->to_mourn_inferior = linux_nat_mourn_inferior;
5602 t->to_thread_alive = linux_nat_thread_alive;
5603 t->to_pid_to_str = linux_nat_pid_to_str;
5604 t->to_thread_name = linux_nat_thread_name;
5605 t->to_has_thread_control = tc_schedlock;
5606 t->to_thread_address_space = linux_nat_thread_address_space;
5607 t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint;
5608 t->to_stopped_data_address = linux_nat_stopped_data_address;
5610 t->to_can_async_p = linux_nat_can_async_p;
5611 t->to_is_async_p = linux_nat_is_async_p;
5612 t->to_supports_non_stop = linux_nat_supports_non_stop;
5613 t->to_async = linux_nat_async;
5614 t->to_terminal_inferior = linux_nat_terminal_inferior;
5615 t->to_terminal_ours = linux_nat_terminal_ours;
5616 t->to_close = linux_nat_close;
5618 /* Methods for non-stop support. */
5619 t->to_stop = linux_nat_stop;
5621 t->to_supports_multi_process = linux_nat_supports_multi_process;
5623 t->to_core_of_thread = linux_nat_core_of_thread;
5625 /* We don't change the stratum; this target will sit at
5626 process_stratum and thread_db will set at thread_stratum. This
5627 is a little strange, since this is a multi-threaded-capable
5628 target, but we want to be on the stack below thread_db, and we
5629 also want to be used for single-threaded processes. */
5634 /* Register a method to call whenever a new thread is attached. */
5636 linux_nat_set_new_thread (struct target_ops *t, void (*new_thread) (ptid_t))
5638 /* Save the pointer. We only support a single registered instance
5639 of the GNU/Linux native target, so we do not need to map this to
5641 linux_nat_new_thread = new_thread;
5644 /* Register a method that converts a siginfo object between the layout
5645 that ptrace returns, and the layout in the architecture of the
5648 linux_nat_set_siginfo_fixup (struct target_ops *t,
5649 int (*siginfo_fixup) (struct siginfo *,
5653 /* Save the pointer. */
5654 linux_nat_siginfo_fixup = siginfo_fixup;
5657 /* Return the saved siginfo associated with PTID. */
5659 linux_nat_get_siginfo (ptid_t ptid)
5661 struct lwp_info *lp = find_lwp_pid (ptid);
5663 gdb_assert (lp != NULL);
5665 return &lp->siginfo;
5668 /* Provide a prototype to silence -Wmissing-prototypes. */
5669 extern initialize_file_ftype _initialize_linux_nat;
5672 _initialize_linux_nat (void)
5674 add_info ("proc", linux_nat_info_proc_cmd, _("\
5675 Show /proc process information about any running process.\n\
5676 Specify any process id, or use the program being debugged by default.\n\
5677 Specify any of the following keywords for detailed info:\n\
5678 mappings -- list of mapped memory regions.\n\
5679 stat -- list a bunch of random process info.\n\
5680 status -- list a different bunch of random process info.\n\
5681 all -- list all available /proc info."));
5683 add_setshow_zinteger_cmd ("lin-lwp", class_maintenance,
5684 &debug_linux_nat, _("\
5685 Set debugging of GNU/Linux lwp module."), _("\
5686 Show debugging of GNU/Linux lwp module."), _("\
5687 Enables printf debugging output."),
5689 show_debug_linux_nat,
5690 &setdebuglist, &showdebuglist);
5692 /* Save this mask as the default. */
5693 sigprocmask (SIG_SETMASK, NULL, &normal_mask);
5695 /* Install a SIGCHLD handler. */
5696 sigchld_action.sa_handler = sigchld_handler;
5697 sigemptyset (&sigchld_action.sa_mask);
5698 sigchld_action.sa_flags = SA_RESTART;
5700 /* Make it the default. */
5701 sigaction (SIGCHLD, &sigchld_action, NULL);
5703 /* Make sure we don't block SIGCHLD during a sigsuspend. */
5704 sigprocmask (SIG_SETMASK, NULL, &suspend_mask);
5705 sigdelset (&suspend_mask, SIGCHLD);
5707 sigemptyset (&blocked_mask);
5709 add_setshow_boolean_cmd ("disable-randomization", class_support,
5710 &disable_randomization, _("\
5711 Set disabling of debuggee's virtual address space randomization."), _("\
5712 Show disabling of debuggee's virtual address space randomization."), _("\
5713 When this mode is on (which is the default), randomization of the virtual\n\
5714 address space is disabled. Standalone programs run with the randomization\n\
5715 enabled by default on some platforms."),
5716 &set_disable_randomization,
5717 &show_disable_randomization,
5718 &setlist, &showlist);
5722 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
5723 the GNU/Linux Threads library and therefore doesn't really belong
5726 /* Read variable NAME in the target and return its value if found.
5727 Otherwise return zero. It is assumed that the type of the variable
5731 get_signo (const char *name)
5733 struct minimal_symbol *ms;
5736 ms = lookup_minimal_symbol (name, NULL, NULL);
5740 if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo,
5741 sizeof (signo)) != 0)
5747 /* Return the set of signals used by the threads library in *SET. */
5750 lin_thread_get_thread_signals (sigset_t *set)
5752 struct sigaction action;
5753 int restart, cancel;
5755 sigemptyset (&blocked_mask);
5758 restart = get_signo ("__pthread_sig_restart");
5759 cancel = get_signo ("__pthread_sig_cancel");
5761 /* LinuxThreads normally uses the first two RT signals, but in some legacy
5762 cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
5763 not provide any way for the debugger to query the signal numbers -
5764 fortunately they don't change! */
5767 restart = __SIGRTMIN;
5770 cancel = __SIGRTMIN + 1;
5772 sigaddset (set, restart);
5773 sigaddset (set, cancel);
5775 /* The GNU/Linux Threads library makes terminating threads send a
5776 special "cancel" signal instead of SIGCHLD. Make sure we catch
5777 those (to prevent them from terminating GDB itself, which is
5778 likely to be their default action) and treat them the same way as
5781 action.sa_handler = sigchld_handler;
5782 sigemptyset (&action.sa_mask);
5783 action.sa_flags = SA_RESTART;
5784 sigaction (cancel, &action, NULL);
5786 /* We block the "cancel" signal throughout this code ... */
5787 sigaddset (&blocked_mask, cancel);
5788 sigprocmask (SIG_BLOCK, &blocked_mask, NULL);
5790 /* ... except during a sigsuspend. */
5791 sigdelset (&suspend_mask, cancel);