1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
4 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-fork.h"
34 #include "gdbthread.h"
38 #include "inf-ptrace.h"
40 #include <sys/param.h> /* for MAXPATHLEN */
41 #include <sys/procfs.h> /* for elf_gregset etc. */
42 #include "elf-bfd.h" /* for elfcore_write_* */
43 #include "gregset.h" /* for gregset */
44 #include "gdbcore.h" /* for get_exec_file */
45 #include <ctype.h> /* for isdigit */
46 #include "gdbthread.h" /* for struct thread_info etc. */
47 #include "gdb_stat.h" /* for struct stat */
48 #include <fcntl.h> /* for O_RDONLY */
50 #include "event-loop.h"
51 #include "event-top.h"
53 #include <sys/types.h>
54 #include "gdb_dirent.h"
55 #include "xml-support.h"
57 #ifdef HAVE_PERSONALITY
58 # include <sys/personality.h>
59 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
60 # define ADDR_NO_RANDOMIZE 0x0040000
62 #endif /* HAVE_PERSONALITY */
64 /* This comment documents high-level logic of this file.
66 Waiting for events in sync mode
67 ===============================
69 When waiting for an event in a specific thread, we just use waitpid, passing
70 the specific pid, and not passing WNOHANG.
72 When waiting for an event in all threads, waitpid is not quite good. Prior to
73 version 2.4, Linux can either wait for event in main thread, or in secondary
74 threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might
75 miss an event. The solution is to use non-blocking waitpid, together with
76 sigsuspend. First, we use non-blocking waitpid to get an event in the main
77 process, if any. Second, we use non-blocking waitpid with the __WCLONED
78 flag to check for events in cloned processes. If nothing is found, we use
79 sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something
80 happened to a child process -- and SIGCHLD will be delivered both for events
81 in main debugged process and in cloned processes. As soon as we know there's
82 an event, we get back to calling nonblocking waitpid with and without __WCLONED.
84 Note that SIGCHLD should be blocked between waitpid and sigsuspend calls,
85 so that we don't miss a signal. If SIGCHLD arrives in between, when it's
86 blocked, the signal becomes pending and sigsuspend immediately
87 notices it and returns.
89 Waiting for events in async mode
90 ================================
92 In async mode, GDB should always be ready to handle both user input and target
93 events, so neither blocking waitpid nor sigsuspend are viable
94 options. Instead, we should notify the GDB main event loop whenever there's
95 unprocessed event from the target. The only way to notify this event loop is
96 to make it wait on input from a pipe, and write something to the pipe whenever
97 there's event. Obviously, if we fail to notify the event loop if there's
98 target event, it's bad. If we notify the event loop when there's no event
99 from target, linux-nat.c will detect that there's no event, actually, and
100 report event of type TARGET_WAITKIND_IGNORE, but it will waste time and
103 The main design point is that every time GDB is outside linux-nat.c, we have a
104 SIGCHLD handler installed that is called when something happens to the target
105 and notifies the GDB event loop. Also, the event is extracted from the target
106 using waitpid and stored for future use. Whenever GDB core decides to handle
107 the event, and calls into linux-nat.c, we disable SIGCHLD and process things
108 as in sync mode, except that before waitpid call we check if there are any
109 previously read events.
111 It could happen that during event processing, we'll try to get more events
112 than there are events in the local queue, which will result to waitpid call.
113 Those waitpid calls, while blocking, are guarantied to always have
114 something for waitpid to return. E.g., stopping a thread with SIGSTOP, and
115 waiting for the lwp to stop.
117 The event loop is notified about new events using a pipe. SIGCHLD handler does
118 waitpid and writes the results in to a pipe. GDB event loop has the other end
119 of the pipe among the sources. When event loop starts to process the event
120 and calls a function in linux-nat.c, all events from the pipe are transferred
121 into a local queue and SIGCHLD is blocked. Further processing goes as in sync
122 mode. Before we return from linux_nat_wait, we transfer all unprocessed events
123 from local queue back to the pipe, so that when we get back to event loop,
124 event loop will notice there's something more to do.
126 SIGCHLD is blocked when we're inside target_wait, so that should we actually
127 want to wait for some more events, SIGCHLD handler does not steal them from
128 us. Technically, it would be possible to add new events to the local queue but
129 it's about the same amount of work as blocking SIGCHLD.
131 This moving of events from pipe into local queue and back into pipe when we
132 enter/leave linux-nat.c is somewhat ugly. Unfortunately, GDB event loop is
133 home-grown and incapable to wait on any queue.
138 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
139 signal is not entirely significant; we just need for a signal to be delivered,
140 so that we can intercept it. SIGSTOP's advantage is that it can not be
141 blocked. A disadvantage is that it is not a real-time signal, so it can only
142 be queued once; we do not keep track of other sources of SIGSTOP.
144 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
145 use them, because they have special behavior when the signal is generated -
146 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
147 kills the entire thread group.
149 A delivered SIGSTOP would stop the entire thread group, not just the thread we
150 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
151 cancel it (by PTRACE_CONT without passing SIGSTOP).
153 We could use a real-time signal instead. This would solve those problems; we
154 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
155 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
156 generates it, and there are races with trying to find a signal that is not
160 #define O_LARGEFILE 0
163 /* If the system headers did not provide the constants, hard-code the normal
165 #ifndef PTRACE_EVENT_FORK
167 #define PTRACE_SETOPTIONS 0x4200
168 #define PTRACE_GETEVENTMSG 0x4201
170 /* options set using PTRACE_SETOPTIONS */
171 #define PTRACE_O_TRACESYSGOOD 0x00000001
172 #define PTRACE_O_TRACEFORK 0x00000002
173 #define PTRACE_O_TRACEVFORK 0x00000004
174 #define PTRACE_O_TRACECLONE 0x00000008
175 #define PTRACE_O_TRACEEXEC 0x00000010
176 #define PTRACE_O_TRACEVFORKDONE 0x00000020
177 #define PTRACE_O_TRACEEXIT 0x00000040
179 /* Wait extended result codes for the above trace options. */
180 #define PTRACE_EVENT_FORK 1
181 #define PTRACE_EVENT_VFORK 2
182 #define PTRACE_EVENT_CLONE 3
183 #define PTRACE_EVENT_EXEC 4
184 #define PTRACE_EVENT_VFORK_DONE 5
185 #define PTRACE_EVENT_EXIT 6
187 #endif /* PTRACE_EVENT_FORK */
189 /* We can't always assume that this flag is available, but all systems
190 with the ptrace event handlers also have __WALL, so it's safe to use
193 #define __WALL 0x40000000 /* Wait for any child. */
196 #ifndef PTRACE_GETSIGINFO
197 #define PTRACE_GETSIGINFO 0x4202
200 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
201 the use of the multi-threaded target. */
202 static struct target_ops *linux_ops;
203 static struct target_ops linux_ops_saved;
205 /* The method to call, if any, when a new thread is attached. */
206 static void (*linux_nat_new_thread) (ptid_t);
208 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
209 Called by our to_xfer_partial. */
210 static LONGEST (*super_xfer_partial) (struct target_ops *,
212 const char *, gdb_byte *,
216 static int debug_linux_nat;
218 show_debug_linux_nat (struct ui_file *file, int from_tty,
219 struct cmd_list_element *c, const char *value)
221 fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"),
225 static int debug_linux_nat_async = 0;
227 show_debug_linux_nat_async (struct ui_file *file, int from_tty,
228 struct cmd_list_element *c, const char *value)
230 fprintf_filtered (file, _("Debugging of GNU/Linux async lwp module is %s.\n"),
234 static int disable_randomization = 1;
237 show_disable_randomization (struct ui_file *file, int from_tty,
238 struct cmd_list_element *c, const char *value)
240 #ifdef HAVE_PERSONALITY
241 fprintf_filtered (file, _("\
242 Disabling randomization of debuggee's virtual address space is %s.\n"),
244 #else /* !HAVE_PERSONALITY */
246 Disabling randomization of debuggee's virtual address space is unsupported on\n\
247 this platform.\n"), file);
248 #endif /* !HAVE_PERSONALITY */
252 set_disable_randomization (char *args, int from_tty, struct cmd_list_element *c)
254 #ifndef HAVE_PERSONALITY
256 Disabling randomization of debuggee's virtual address space is unsupported on\n\
258 #endif /* !HAVE_PERSONALITY */
261 static int linux_parent_pid;
263 struct simple_pid_list
267 struct simple_pid_list *next;
269 struct simple_pid_list *stopped_pids;
271 /* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACEFORK
272 can not be used, 1 if it can. */
274 static int linux_supports_tracefork_flag = -1;
276 /* If we have PTRACE_O_TRACEFORK, this flag indicates whether we also have
277 PTRACE_O_TRACEVFORKDONE. */
279 static int linux_supports_tracevforkdone_flag = -1;
281 /* Async mode support */
283 /* Zero if the async mode, although enabled, is masked, which means
284 linux_nat_wait should behave as if async mode was off. */
285 static int linux_nat_async_mask_value = 1;
287 /* The read/write ends of the pipe registered as waitable file in the
289 static int linux_nat_event_pipe[2] = { -1, -1 };
291 /* Number of queued events in the pipe. */
292 static volatile int linux_nat_num_queued_events;
294 /* The possible SIGCHLD handling states. */
298 /* SIGCHLD disabled, with action set to sigchld_handler, for the
299 sigsuspend in linux_nat_wait. */
301 /* SIGCHLD enabled, with action set to async_sigchld_handler. */
303 /* Set SIGCHLD to default action. Used while creating an
308 /* The current SIGCHLD handling state. */
309 static enum sigchld_state linux_nat_async_events_state;
311 static enum sigchld_state linux_nat_async_events (enum sigchld_state enable);
312 static void pipe_to_local_event_queue (void);
313 static void local_event_queue_to_pipe (void);
314 static void linux_nat_event_pipe_push (int pid, int status, int options);
315 static int linux_nat_event_pipe_pop (int* ptr_status, int* ptr_options);
316 static void linux_nat_set_async_mode (int on);
317 static void linux_nat_async (void (*callback)
318 (enum inferior_event_type event_type, void *context),
320 static int linux_nat_async_mask (int mask);
321 static int kill_lwp (int lwpid, int signo);
323 static int stop_callback (struct lwp_info *lp, void *data);
325 /* Captures the result of a successful waitpid call, along with the
326 options used in that call. */
327 struct waitpid_result
332 struct waitpid_result *next;
335 /* A singly-linked list of the results of the waitpid calls performed
336 in the async SIGCHLD handler. */
337 static struct waitpid_result *waitpid_queue = NULL;
339 /* Similarly to `waitpid', but check the local event queue instead of
340 querying the kernel queue. If PEEK, don't remove the event found
344 queued_waitpid_1 (int pid, int *status, int flags, int peek)
346 struct waitpid_result *msg = waitpid_queue, *prev = NULL;
348 if (debug_linux_nat_async)
349 fprintf_unfiltered (gdb_stdlog,
351 QWPID: linux_nat_async_events_state(%d), linux_nat_num_queued_events(%d)\n",
352 linux_nat_async_events_state,
353 linux_nat_num_queued_events);
357 for (; msg; prev = msg, msg = msg->next)
358 if (pid == -1 || pid == msg->pid)
361 else if (flags & __WCLONE)
363 for (; msg; prev = msg, msg = msg->next)
364 if (msg->options & __WCLONE
365 && (pid == -1 || pid == msg->pid))
370 for (; msg; prev = msg, msg = msg->next)
371 if ((msg->options & __WCLONE) == 0
372 && (pid == -1 || pid == msg->pid))
381 *status = msg->status;
384 if (debug_linux_nat_async)
385 fprintf_unfiltered (gdb_stdlog, "QWPID: pid(%d), status(%x)\n",
391 prev->next = msg->next;
393 waitpid_queue = msg->next;
402 if (debug_linux_nat_async)
403 fprintf_unfiltered (gdb_stdlog, "QWPID: miss\n");
410 /* Similarly to `waitpid', but check the local event queue. */
413 queued_waitpid (int pid, int *status, int flags)
415 return queued_waitpid_1 (pid, status, flags, 0);
419 push_waitpid (int pid, int status, int options)
421 struct waitpid_result *event, *new_event;
423 new_event = xmalloc (sizeof (*new_event));
424 new_event->pid = pid;
425 new_event->status = status;
426 new_event->options = options;
427 new_event->next = NULL;
431 for (event = waitpid_queue;
432 event && event->next;
436 event->next = new_event;
439 waitpid_queue = new_event;
442 /* Drain all queued events of PID. If PID is -1, the effect is of
443 draining all events. */
445 drain_queued_events (int pid)
447 while (queued_waitpid (pid, NULL, __WALL) != -1)
452 /* Trivial list manipulation functions to keep track of a list of
453 new stopped processes. */
455 add_to_pid_list (struct simple_pid_list **listp, int pid, int status)
457 struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list));
459 new_pid->status = status;
460 new_pid->next = *listp;
465 pull_pid_from_list (struct simple_pid_list **listp, int pid, int *status)
467 struct simple_pid_list **p;
469 for (p = listp; *p != NULL; p = &(*p)->next)
470 if ((*p)->pid == pid)
472 struct simple_pid_list *next = (*p)->next;
473 *status = (*p)->status;
482 linux_record_stopped_pid (int pid, int status)
484 add_to_pid_list (&stopped_pids, pid, status);
488 /* A helper function for linux_test_for_tracefork, called after fork (). */
491 linux_tracefork_child (void)
495 ptrace (PTRACE_TRACEME, 0, 0, 0);
496 kill (getpid (), SIGSTOP);
501 /* Wrapper function for waitpid which handles EINTR, and checks for
502 locally queued events. */
505 my_waitpid (int pid, int *status, int flags)
509 /* There should be no concurrent calls to waitpid. */
510 gdb_assert (linux_nat_async_events_state == sigchld_sync);
512 ret = queued_waitpid (pid, status, flags);
518 ret = waitpid (pid, status, flags);
520 while (ret == -1 && errno == EINTR);
525 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events.
527 First, we try to enable fork tracing on ORIGINAL_PID. If this fails,
528 we know that the feature is not available. This may change the tracing
529 options for ORIGINAL_PID, but we'll be setting them shortly anyway.
531 However, if it succeeds, we don't know for sure that the feature is
532 available; old versions of PTRACE_SETOPTIONS ignored unknown options. We
533 create a child process, attach to it, use PTRACE_SETOPTIONS to enable
534 fork tracing, and let it fork. If the process exits, we assume that we
535 can't use TRACEFORK; if we get the fork notification, and we can extract
536 the new child's PID, then we assume that we can. */
539 linux_test_for_tracefork (int original_pid)
541 int child_pid, ret, status;
543 enum sigchld_state async_events_original_state;
545 async_events_original_state = linux_nat_async_events (sigchld_sync);
547 linux_supports_tracefork_flag = 0;
548 linux_supports_tracevforkdone_flag = 0;
550 ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACEFORK);
556 perror_with_name (("fork"));
559 linux_tracefork_child ();
561 ret = my_waitpid (child_pid, &status, 0);
563 perror_with_name (("waitpid"));
564 else if (ret != child_pid)
565 error (_("linux_test_for_tracefork: waitpid: unexpected result %d."), ret);
566 if (! WIFSTOPPED (status))
567 error (_("linux_test_for_tracefork: waitpid: unexpected status %d."), status);
569 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK);
572 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
575 warning (_("linux_test_for_tracefork: failed to kill child"));
576 linux_nat_async_events (async_events_original_state);
580 ret = my_waitpid (child_pid, &status, 0);
581 if (ret != child_pid)
582 warning (_("linux_test_for_tracefork: failed to wait for killed child"));
583 else if (!WIFSIGNALED (status))
584 warning (_("linux_test_for_tracefork: unexpected wait status 0x%x from "
585 "killed child"), status);
587 linux_nat_async_events (async_events_original_state);
591 /* Check whether PTRACE_O_TRACEVFORKDONE is available. */
592 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0,
593 PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORKDONE);
594 linux_supports_tracevforkdone_flag = (ret == 0);
596 ret = ptrace (PTRACE_CONT, child_pid, 0, 0);
598 warning (_("linux_test_for_tracefork: failed to resume child"));
600 ret = my_waitpid (child_pid, &status, 0);
602 if (ret == child_pid && WIFSTOPPED (status)
603 && status >> 16 == PTRACE_EVENT_FORK)
606 ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
607 if (ret == 0 && second_pid != 0)
611 linux_supports_tracefork_flag = 1;
612 my_waitpid (second_pid, &second_status, 0);
613 ret = ptrace (PTRACE_KILL, second_pid, 0, 0);
615 warning (_("linux_test_for_tracefork: failed to kill second child"));
616 my_waitpid (second_pid, &status, 0);
620 warning (_("linux_test_for_tracefork: unexpected result from waitpid "
621 "(%d, status 0x%x)"), ret, status);
623 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
625 warning (_("linux_test_for_tracefork: failed to kill child"));
626 my_waitpid (child_pid, &status, 0);
628 linux_nat_async_events (async_events_original_state);
631 /* Return non-zero iff we have tracefork functionality available.
632 This function also sets linux_supports_tracefork_flag. */
635 linux_supports_tracefork (int pid)
637 if (linux_supports_tracefork_flag == -1)
638 linux_test_for_tracefork (pid);
639 return linux_supports_tracefork_flag;
643 linux_supports_tracevforkdone (int pid)
645 if (linux_supports_tracefork_flag == -1)
646 linux_test_for_tracefork (pid);
647 return linux_supports_tracevforkdone_flag;
652 linux_enable_event_reporting (ptid_t ptid)
654 int pid = ptid_get_lwp (ptid);
658 pid = ptid_get_pid (ptid);
660 if (! linux_supports_tracefork (pid))
663 options = PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK | PTRACE_O_TRACEEXEC
664 | PTRACE_O_TRACECLONE;
665 if (linux_supports_tracevforkdone (pid))
666 options |= PTRACE_O_TRACEVFORKDONE;
668 /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support
669 read-only process state. */
671 ptrace (PTRACE_SETOPTIONS, pid, 0, options);
675 linux_child_post_attach (int pid)
677 linux_enable_event_reporting (pid_to_ptid (pid));
678 check_for_thread_db ();
682 linux_child_post_startup_inferior (ptid_t ptid)
684 linux_enable_event_reporting (ptid);
685 check_for_thread_db ();
689 linux_child_follow_fork (struct target_ops *ops, int follow_child)
692 struct target_waitstatus last_status;
694 int parent_pid, child_pid;
696 if (target_can_async_p ())
697 target_async (NULL, 0);
699 get_last_target_status (&last_ptid, &last_status);
700 has_vforked = (last_status.kind == TARGET_WAITKIND_VFORKED);
701 parent_pid = ptid_get_lwp (last_ptid);
703 parent_pid = ptid_get_pid (last_ptid);
704 child_pid = PIDGET (last_status.value.related_pid);
708 /* We're already attached to the parent, by default. */
710 /* Before detaching from the child, remove all breakpoints from
711 it. (This won't actually modify the breakpoint list, but will
712 physically remove the breakpoints from the child.) */
713 /* If we vforked this will remove the breakpoints from the parent
714 also, but they'll be reinserted below. */
715 detach_breakpoints (child_pid);
717 /* Detach new forked process? */
720 if (info_verbose || debug_linux_nat)
722 target_terminal_ours ();
723 fprintf_filtered (gdb_stdlog,
724 "Detaching after fork from child process %d.\n",
728 ptrace (PTRACE_DETACH, child_pid, 0, 0);
732 struct fork_info *fp;
733 struct inferior *parent_inf, *child_inf;
735 /* Add process to GDB's tables. */
736 child_inf = add_inferior (child_pid);
738 parent_inf = find_inferior_pid (GET_PID (last_ptid));
739 child_inf->attach_flag = parent_inf->attach_flag;
741 /* Retain child fork in ptrace (stopped) state. */
742 fp = find_fork_pid (child_pid);
744 fp = add_fork (child_pid);
745 fork_save_infrun_state (fp, 0);
750 gdb_assert (linux_supports_tracefork_flag >= 0);
751 if (linux_supports_tracevforkdone (0))
755 ptrace (PTRACE_CONT, parent_pid, 0, 0);
756 my_waitpid (parent_pid, &status, __WALL);
757 if ((status >> 16) != PTRACE_EVENT_VFORK_DONE)
758 warning (_("Unexpected waitpid result %06x when waiting for "
759 "vfork-done"), status);
763 /* We can't insert breakpoints until the child has
764 finished with the shared memory region. We need to
765 wait until that happens. Ideal would be to just
767 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
768 - waitpid (parent_pid, &status, __WALL);
769 However, most architectures can't handle a syscall
770 being traced on the way out if it wasn't traced on
773 We might also think to loop, continuing the child
774 until it exits or gets a SIGTRAP. One problem is
775 that the child might call ptrace with PTRACE_TRACEME.
777 There's no simple and reliable way to figure out when
778 the vforked child will be done with its copy of the
779 shared memory. We could step it out of the syscall,
780 two instructions, let it go, and then single-step the
781 parent once. When we have hardware single-step, this
782 would work; with software single-step it could still
783 be made to work but we'd have to be able to insert
784 single-step breakpoints in the child, and we'd have
785 to insert -just- the single-step breakpoint in the
786 parent. Very awkward.
788 In the end, the best we can do is to make sure it
789 runs for a little while. Hopefully it will be out of
790 range of any breakpoints we reinsert. Usually this
791 is only the single-step breakpoint at vfork's return
797 /* Since we vforked, breakpoints were removed in the parent
798 too. Put them back. */
799 reattach_breakpoints (parent_pid);
804 struct thread_info *last_tp = find_thread_pid (last_ptid);
805 struct thread_info *tp;
806 char child_pid_spelling[40];
807 struct inferior *parent_inf, *child_inf;
809 /* Copy user stepping state to the new inferior thread. */
810 struct breakpoint *step_resume_breakpoint = last_tp->step_resume_breakpoint;
811 CORE_ADDR step_range_start = last_tp->step_range_start;
812 CORE_ADDR step_range_end = last_tp->step_range_end;
813 struct frame_id step_frame_id = last_tp->step_frame_id;
815 /* Otherwise, deleting the parent would get rid of this
817 last_tp->step_resume_breakpoint = NULL;
819 /* Needed to keep the breakpoint lists in sync. */
821 detach_breakpoints (child_pid);
823 /* Before detaching from the parent, remove all breakpoints from it. */
824 remove_breakpoints ();
826 if (info_verbose || debug_linux_nat)
828 target_terminal_ours ();
829 fprintf_filtered (gdb_stdlog,
830 "Attaching after fork to child process %d.\n",
834 /* Add the new inferior first, so that the target_detach below
835 doesn't unpush the target. */
837 child_inf = add_inferior (child_pid);
839 parent_inf = find_inferior_pid (GET_PID (last_ptid));
840 child_inf->attach_flag = parent_inf->attach_flag;
842 /* If we're vforking, we may want to hold on to the parent until
843 the child exits or execs. At exec time we can remove the old
844 breakpoints from the parent and detach it; at exit time we
845 could do the same (or even, sneakily, resume debugging it - the
846 child's exec has failed, or something similar).
848 This doesn't clean up "properly", because we can't call
849 target_detach, but that's OK; if the current target is "child",
850 then it doesn't need any further cleanups, and lin_lwp will
851 generally not encounter vfork (vfork is defined to fork
854 The holding part is very easy if we have VFORKDONE events;
855 but keeping track of both processes is beyond GDB at the
856 moment. So we don't expose the parent to the rest of GDB.
857 Instead we quietly hold onto it until such time as we can
862 linux_parent_pid = parent_pid;
863 detach_inferior (parent_pid);
865 else if (!detach_fork)
867 struct fork_info *fp;
868 /* Retain parent fork in ptrace (stopped) state. */
869 fp = find_fork_pid (parent_pid);
871 fp = add_fork (parent_pid);
872 fork_save_infrun_state (fp, 0);
874 /* Also add an entry for the child fork. */
875 fp = find_fork_pid (child_pid);
877 fp = add_fork (child_pid);
878 fork_save_infrun_state (fp, 0);
881 target_detach (NULL, 0);
883 inferior_ptid = ptid_build (child_pid, child_pid, 0);
885 linux_nat_switch_fork (inferior_ptid);
886 check_for_thread_db ();
888 tp = inferior_thread ();
889 tp->step_resume_breakpoint = step_resume_breakpoint;
890 tp->step_range_start = step_range_start;
891 tp->step_range_end = step_range_end;
892 tp->step_frame_id = step_frame_id;
894 /* Reset breakpoints in the child as appropriate. */
895 follow_inferior_reset_breakpoints ();
898 if (target_can_async_p ())
899 target_async (inferior_event_handler, 0);
906 linux_child_insert_fork_catchpoint (int pid)
908 if (! linux_supports_tracefork (pid))
909 error (_("Your system does not support fork catchpoints."));
913 linux_child_insert_vfork_catchpoint (int pid)
915 if (!linux_supports_tracefork (pid))
916 error (_("Your system does not support vfork catchpoints."));
920 linux_child_insert_exec_catchpoint (int pid)
922 if (!linux_supports_tracefork (pid))
923 error (_("Your system does not support exec catchpoints."));
926 /* On GNU/Linux there are no real LWP's. The closest thing to LWP's
927 are processes sharing the same VM space. A multi-threaded process
928 is basically a group of such processes. However, such a grouping
929 is almost entirely a user-space issue; the kernel doesn't enforce
930 such a grouping at all (this might change in the future). In
931 general, we'll rely on the threads library (i.e. the GNU/Linux
932 Threads library) to provide such a grouping.
934 It is perfectly well possible to write a multi-threaded application
935 without the assistance of a threads library, by using the clone
936 system call directly. This module should be able to give some
937 rudimentary support for debugging such applications if developers
938 specify the CLONE_PTRACE flag in the clone system call, and are
939 using the Linux kernel 2.4 or above.
941 Note that there are some peculiarities in GNU/Linux that affect
944 - In general one should specify the __WCLONE flag to waitpid in
945 order to make it report events for any of the cloned processes
946 (and leave it out for the initial process). However, if a cloned
947 process has exited the exit status is only reported if the
948 __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
949 we cannot use it since GDB must work on older systems too.
951 - When a traced, cloned process exits and is waited for by the
952 debugger, the kernel reassigns it to the original parent and
953 keeps it around as a "zombie". Somehow, the GNU/Linux Threads
954 library doesn't notice this, which leads to the "zombie problem":
955 When debugged a multi-threaded process that spawns a lot of
956 threads will run out of processes, even if the threads exit,
957 because the "zombies" stay around. */
959 /* List of known LWPs. */
960 struct lwp_info *lwp_list;
962 /* Number of LWPs in the list. */
966 /* Original signal mask. */
967 static sigset_t normal_mask;
969 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
970 _initialize_linux_nat. */
971 static sigset_t suspend_mask;
973 /* SIGCHLD action for synchronous mode. */
974 struct sigaction sync_sigchld_action;
976 /* SIGCHLD action for asynchronous mode. */
977 static struct sigaction async_sigchld_action;
979 /* SIGCHLD default action, to pass to new inferiors. */
980 static struct sigaction sigchld_default_action;
983 /* Prototypes for local functions. */
984 static int stop_wait_callback (struct lwp_info *lp, void *data);
985 static int linux_nat_thread_alive (ptid_t ptid);
986 static char *linux_child_pid_to_exec_file (int pid);
987 static int cancel_breakpoint (struct lwp_info *lp);
990 /* Convert wait status STATUS to a string. Used for printing debug
994 status_to_str (int status)
998 if (WIFSTOPPED (status))
999 snprintf (buf, sizeof (buf), "%s (stopped)",
1000 strsignal (WSTOPSIG (status)));
1001 else if (WIFSIGNALED (status))
1002 snprintf (buf, sizeof (buf), "%s (terminated)",
1003 strsignal (WSTOPSIG (status)));
1005 snprintf (buf, sizeof (buf), "%d (exited)", WEXITSTATUS (status));
1010 /* Initialize the list of LWPs. Note that this module, contrary to
1011 what GDB's generic threads layer does for its thread list,
1012 re-initializes the LWP lists whenever we mourn or detach (which
1013 doesn't involve mourning) the inferior. */
1016 init_lwp_list (void)
1018 struct lwp_info *lp, *lpnext;
1020 for (lp = lwp_list; lp; lp = lpnext)
1030 /* Add the LWP specified by PID to the list. Return a pointer to the
1031 structure describing the new LWP. The LWP should already be stopped
1032 (with an exception for the very first LWP). */
1034 static struct lwp_info *
1035 add_lwp (ptid_t ptid)
1037 struct lwp_info *lp;
1039 gdb_assert (is_lwp (ptid));
1041 lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info));
1043 memset (lp, 0, sizeof (struct lwp_info));
1045 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
1049 lp->next = lwp_list;
1053 if (num_lwps > 1 && linux_nat_new_thread != NULL)
1054 linux_nat_new_thread (ptid);
1059 /* Remove the LWP specified by PID from the list. */
1062 delete_lwp (ptid_t ptid)
1064 struct lwp_info *lp, *lpprev;
1068 for (lp = lwp_list; lp; lpprev = lp, lp = lp->next)
1069 if (ptid_equal (lp->ptid, ptid))
1078 lpprev->next = lp->next;
1080 lwp_list = lp->next;
1085 /* Return a pointer to the structure describing the LWP corresponding
1086 to PID. If no corresponding LWP could be found, return NULL. */
1088 static struct lwp_info *
1089 find_lwp_pid (ptid_t ptid)
1091 struct lwp_info *lp;
1095 lwp = GET_LWP (ptid);
1097 lwp = GET_PID (ptid);
1099 for (lp = lwp_list; lp; lp = lp->next)
1100 if (lwp == GET_LWP (lp->ptid))
1106 /* Call CALLBACK with its second argument set to DATA for every LWP in
1107 the list. If CALLBACK returns 1 for a particular LWP, return a
1108 pointer to the structure describing that LWP immediately.
1109 Otherwise return NULL. */
1112 iterate_over_lwps (int (*callback) (struct lwp_info *, void *), void *data)
1114 struct lwp_info *lp, *lpnext;
1116 for (lp = lwp_list; lp; lp = lpnext)
1119 if ((*callback) (lp, data))
1126 /* Update our internal state when changing from one fork (checkpoint,
1127 et cetera) to another indicated by NEW_PTID. We can only switch
1128 single-threaded applications, so we only create one new LWP, and
1129 the previous list is discarded. */
1132 linux_nat_switch_fork (ptid_t new_ptid)
1134 struct lwp_info *lp;
1137 lp = add_lwp (new_ptid);
1140 init_thread_list ();
1141 add_thread_silent (new_ptid);
1144 /* Handle the exit of a single thread LP. */
1147 exit_lwp (struct lwp_info *lp)
1149 struct thread_info *th = find_thread_pid (lp->ptid);
1153 if (print_thread_events)
1154 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid));
1156 delete_thread (lp->ptid);
1159 delete_lwp (lp->ptid);
1162 /* Detect `T (stopped)' in `/proc/PID/status'.
1163 Other states including `T (tracing stop)' are reported as false. */
1166 pid_is_stopped (pid_t pid)
1172 snprintf (buf, sizeof (buf), "/proc/%d/status", (int) pid);
1173 status_file = fopen (buf, "r");
1174 if (status_file != NULL)
1178 while (fgets (buf, sizeof (buf), status_file))
1180 if (strncmp (buf, "State:", 6) == 0)
1186 if (have_state && strstr (buf, "T (stopped)") != NULL)
1188 fclose (status_file);
1193 /* Wait for the LWP specified by LP, which we have just attached to.
1194 Returns a wait status for that LWP, to cache. */
1197 linux_nat_post_attach_wait (ptid_t ptid, int first, int *cloned,
1200 pid_t new_pid, pid = GET_LWP (ptid);
1203 if (pid_is_stopped (pid))
1205 if (debug_linux_nat)
1206 fprintf_unfiltered (gdb_stdlog,
1207 "LNPAW: Attaching to a stopped process\n");
1209 /* The process is definitely stopped. It is in a job control
1210 stop, unless the kernel predates the TASK_STOPPED /
1211 TASK_TRACED distinction, in which case it might be in a
1212 ptrace stop. Make sure it is in a ptrace stop; from there we
1213 can kill it, signal it, et cetera.
1215 First make sure there is a pending SIGSTOP. Since we are
1216 already attached, the process can not transition from stopped
1217 to running without a PTRACE_CONT; so we know this signal will
1218 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1219 probably already in the queue (unless this kernel is old
1220 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1221 is not an RT signal, it can only be queued once. */
1222 kill_lwp (pid, SIGSTOP);
1224 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1225 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1226 ptrace (PTRACE_CONT, pid, 0, 0);
1229 /* Make sure the initial process is stopped. The user-level threads
1230 layer might want to poke around in the inferior, and that won't
1231 work if things haven't stabilized yet. */
1232 new_pid = my_waitpid (pid, &status, 0);
1233 if (new_pid == -1 && errno == ECHILD)
1236 warning (_("%s is a cloned process"), target_pid_to_str (ptid));
1238 /* Try again with __WCLONE to check cloned processes. */
1239 new_pid = my_waitpid (pid, &status, __WCLONE);
1243 gdb_assert (pid == new_pid && WIFSTOPPED (status));
1245 if (WSTOPSIG (status) != SIGSTOP)
1248 if (debug_linux_nat)
1249 fprintf_unfiltered (gdb_stdlog,
1250 "LNPAW: Received %s after attaching\n",
1251 status_to_str (status));
1257 /* Attach to the LWP specified by PID. Return 0 if successful or -1
1258 if the new LWP could not be attached. */
1261 lin_lwp_attach_lwp (ptid_t ptid)
1263 struct lwp_info *lp;
1264 enum sigchld_state async_events_original_state;
1266 gdb_assert (is_lwp (ptid));
1268 async_events_original_state = linux_nat_async_events (sigchld_sync);
1270 lp = find_lwp_pid (ptid);
1272 /* We assume that we're already attached to any LWP that has an id
1273 equal to the overall process id, and to any LWP that is already
1274 in our list of LWPs. If we're not seeing exit events from threads
1275 and we've had PID wraparound since we last tried to stop all threads,
1276 this assumption might be wrong; fortunately, this is very unlikely
1278 if (GET_LWP (ptid) != GET_PID (ptid) && lp == NULL)
1280 int status, cloned = 0, signalled = 0;
1282 if (ptrace (PTRACE_ATTACH, GET_LWP (ptid), 0, 0) < 0)
1284 /* If we fail to attach to the thread, issue a warning,
1285 but continue. One way this can happen is if thread
1286 creation is interrupted; as of Linux kernel 2.6.19, a
1287 bug may place threads in the thread list and then fail
1289 warning (_("Can't attach %s: %s"), target_pid_to_str (ptid),
1290 safe_strerror (errno));
1294 if (debug_linux_nat)
1295 fprintf_unfiltered (gdb_stdlog,
1296 "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
1297 target_pid_to_str (ptid));
1299 status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled);
1300 lp = add_lwp (ptid);
1302 lp->cloned = cloned;
1303 lp->signalled = signalled;
1304 if (WSTOPSIG (status) != SIGSTOP)
1307 lp->status = status;
1310 target_post_attach (GET_LWP (lp->ptid));
1312 if (debug_linux_nat)
1314 fprintf_unfiltered (gdb_stdlog,
1315 "LLAL: waitpid %s received %s\n",
1316 target_pid_to_str (ptid),
1317 status_to_str (status));
1322 /* We assume that the LWP representing the original process is
1323 already stopped. Mark it as stopped in the data structure
1324 that the GNU/linux ptrace layer uses to keep track of
1325 threads. Note that this won't have already been done since
1326 the main thread will have, we assume, been stopped by an
1327 attach from a different layer. */
1329 lp = add_lwp (ptid);
1333 linux_nat_async_events (async_events_original_state);
1338 linux_nat_create_inferior (struct target_ops *ops,
1339 char *exec_file, char *allargs, char **env,
1342 int saved_async = 0;
1343 #ifdef HAVE_PERSONALITY
1344 int personality_orig = 0, personality_set = 0;
1345 #endif /* HAVE_PERSONALITY */
1347 /* The fork_child mechanism is synchronous and calls target_wait, so
1348 we have to mask the async mode. */
1350 if (target_can_async_p ())
1351 /* Mask async mode. Creating a child requires a loop calling
1352 wait_for_inferior currently. */
1353 saved_async = linux_nat_async_mask (0);
1356 /* Restore the original signal mask. */
1357 sigprocmask (SIG_SETMASK, &normal_mask, NULL);
1358 /* Make sure we don't block SIGCHLD during a sigsuspend. */
1359 suspend_mask = normal_mask;
1360 sigdelset (&suspend_mask, SIGCHLD);
1363 /* Set SIGCHLD to the default action, until after execing the child,
1364 since the inferior inherits the superior's signal mask. It will
1365 be blocked again in linux_nat_wait, which is only reached after
1366 the inferior execing. */
1367 linux_nat_async_events (sigchld_default);
1369 #ifdef HAVE_PERSONALITY
1370 if (disable_randomization)
1373 personality_orig = personality (0xffffffff);
1374 if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE))
1376 personality_set = 1;
1377 personality (personality_orig | ADDR_NO_RANDOMIZE);
1379 if (errno != 0 || (personality_set
1380 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE)))
1381 warning (_("Error disabling address space randomization: %s"),
1382 safe_strerror (errno));
1384 #endif /* HAVE_PERSONALITY */
1386 linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty);
1388 #ifdef HAVE_PERSONALITY
1389 if (personality_set)
1392 personality (personality_orig);
1394 warning (_("Error restoring address space randomization: %s"),
1395 safe_strerror (errno));
1397 #endif /* HAVE_PERSONALITY */
1400 linux_nat_async_mask (saved_async);
1404 linux_nat_attach (struct target_ops *ops, char *args, int from_tty)
1406 struct lwp_info *lp;
1410 /* FIXME: We should probably accept a list of process id's, and
1411 attach all of them. */
1412 linux_ops->to_attach (ops, args, from_tty);
1414 if (!target_can_async_p ())
1416 /* Restore the original signal mask. */
1417 sigprocmask (SIG_SETMASK, &normal_mask, NULL);
1418 /* Make sure we don't block SIGCHLD during a sigsuspend. */
1419 suspend_mask = normal_mask;
1420 sigdelset (&suspend_mask, SIGCHLD);
1423 /* The ptrace base target adds the main thread with (pid,0,0)
1424 format. Decorate it with lwp info. */
1425 ptid = BUILD_LWP (GET_PID (inferior_ptid), GET_PID (inferior_ptid));
1426 thread_change_ptid (inferior_ptid, ptid);
1428 /* Add the initial process as the first LWP to the list. */
1429 lp = add_lwp (ptid);
1431 status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->cloned,
1435 /* Save the wait status to report later. */
1437 if (debug_linux_nat)
1438 fprintf_unfiltered (gdb_stdlog,
1439 "LNA: waitpid %ld, saving status %s\n",
1440 (long) GET_PID (lp->ptid), status_to_str (status));
1442 if (!target_can_async_p ())
1443 lp->status = status;
1446 /* We already waited for this LWP, so put the wait result on the
1447 pipe. The event loop will wake up and gets us to handling
1449 linux_nat_event_pipe_push (GET_PID (lp->ptid), status,
1450 lp->cloned ? __WCLONE : 0);
1451 /* Register in the event loop. */
1452 target_async (inferior_event_handler, 0);
1456 /* Get pending status of LP. */
1458 get_pending_status (struct lwp_info *lp, int *status)
1460 struct target_waitstatus last;
1463 get_last_target_status (&last_ptid, &last);
1465 /* If this lwp is the ptid that GDB is processing an event from, the
1466 signal will be in stop_signal. Otherwise, in all-stop + sync
1467 mode, we may cache pending events in lp->status while trying to
1468 stop all threads (see stop_wait_callback). In async mode, the
1469 events are always cached in waitpid_queue. */
1475 enum target_signal signo = TARGET_SIGNAL_0;
1477 if (is_executing (lp->ptid))
1479 /* If the core thought this lwp was executing --- e.g., the
1480 executing property hasn't been updated yet, but the
1481 thread has been stopped with a stop_callback /
1482 stop_wait_callback sequence (see linux_nat_detach for
1483 example) --- we can only have pending events in the local
1485 if (queued_waitpid (GET_LWP (lp->ptid), status, __WALL) != -1)
1487 if (WIFSTOPPED (*status))
1488 signo = target_signal_from_host (WSTOPSIG (*status));
1490 /* If not stopped, then the lwp is gone, no use in
1491 resending a signal. */
1496 /* If the core knows the thread is not executing, then we
1497 have the last signal recorded in
1498 thread_info->stop_signal. */
1500 struct thread_info *tp = find_thread_pid (lp->ptid);
1501 signo = tp->stop_signal;
1504 if (signo != TARGET_SIGNAL_0
1505 && !signal_pass_state (signo))
1507 if (debug_linux_nat)
1508 fprintf_unfiltered (gdb_stdlog, "\
1509 GPT: lwp %s had signal %s, but it is in no pass state\n",
1510 target_pid_to_str (lp->ptid),
1511 target_signal_to_string (signo));
1515 if (signo != TARGET_SIGNAL_0)
1516 *status = W_STOPCODE (target_signal_to_host (signo));
1518 if (debug_linux_nat)
1519 fprintf_unfiltered (gdb_stdlog,
1520 "GPT: lwp %s as pending signal %s\n",
1521 target_pid_to_str (lp->ptid),
1522 target_signal_to_string (signo));
1527 if (GET_LWP (lp->ptid) == GET_LWP (last_ptid))
1529 struct thread_info *tp = find_thread_pid (lp->ptid);
1530 if (tp->stop_signal != TARGET_SIGNAL_0
1531 && signal_pass_state (tp->stop_signal))
1532 *status = W_STOPCODE (target_signal_to_host (tp->stop_signal));
1534 else if (target_can_async_p ())
1535 queued_waitpid (GET_LWP (lp->ptid), status, __WALL);
1537 *status = lp->status;
1544 detach_callback (struct lwp_info *lp, void *data)
1546 gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status));
1548 if (debug_linux_nat && lp->status)
1549 fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n",
1550 strsignal (WSTOPSIG (lp->status)),
1551 target_pid_to_str (lp->ptid));
1553 /* If there is a pending SIGSTOP, get rid of it. */
1556 if (debug_linux_nat)
1557 fprintf_unfiltered (gdb_stdlog,
1558 "DC: Sending SIGCONT to %s\n",
1559 target_pid_to_str (lp->ptid));
1561 kill_lwp (GET_LWP (lp->ptid), SIGCONT);
1565 /* We don't actually detach from the LWP that has an id equal to the
1566 overall process id just yet. */
1567 if (GET_LWP (lp->ptid) != GET_PID (lp->ptid))
1571 /* Pass on any pending signal for this LWP. */
1572 get_pending_status (lp, &status);
1575 if (ptrace (PTRACE_DETACH, GET_LWP (lp->ptid), 0,
1576 WSTOPSIG (status)) < 0)
1577 error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid),
1578 safe_strerror (errno));
1580 if (debug_linux_nat)
1581 fprintf_unfiltered (gdb_stdlog,
1582 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1583 target_pid_to_str (lp->ptid),
1584 strsignal (WSTOPSIG (lp->status)));
1586 delete_lwp (lp->ptid);
1593 linux_nat_detach (struct target_ops *ops, char *args, int from_tty)
1597 enum target_signal sig;
1599 if (target_can_async_p ())
1600 linux_nat_async (NULL, 0);
1602 /* Stop all threads before detaching. ptrace requires that the
1603 thread is stopped to sucessfully detach. */
1604 iterate_over_lwps (stop_callback, NULL);
1605 /* ... and wait until all of them have reported back that
1606 they're no longer running. */
1607 iterate_over_lwps (stop_wait_callback, NULL);
1609 iterate_over_lwps (detach_callback, NULL);
1611 /* Only the initial process should be left right now. */
1612 gdb_assert (num_lwps == 1);
1614 /* Pass on any pending signal for the last LWP. */
1615 if ((args == NULL || *args == '\0')
1616 && get_pending_status (lwp_list, &status) != -1
1617 && WIFSTOPPED (status))
1619 /* Put the signal number in ARGS so that inf_ptrace_detach will
1620 pass it along with PTRACE_DETACH. */
1622 sprintf (args, "%d", (int) WSTOPSIG (status));
1623 fprintf_unfiltered (gdb_stdlog,
1624 "LND: Sending signal %s to %s\n",
1626 target_pid_to_str (lwp_list->ptid));
1629 /* Destroy LWP info; it's no longer valid. */
1632 pid = ptid_get_pid (inferior_ptid);
1634 if (target_can_async_p ())
1635 drain_queued_events (pid);
1637 if (forks_exist_p ())
1639 /* Multi-fork case. The current inferior_ptid is being detached
1640 from, but there are other viable forks to debug. Detach from
1641 the current fork, and context-switch to the first
1643 linux_fork_detach (args, from_tty);
1645 if (non_stop && target_can_async_p ())
1646 target_async (inferior_event_handler, 0);
1649 linux_ops->to_detach (ops, args, from_tty);
1655 resume_callback (struct lwp_info *lp, void *data)
1657 if (lp->stopped && lp->status == 0)
1659 linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)),
1660 0, TARGET_SIGNAL_0);
1661 if (debug_linux_nat)
1662 fprintf_unfiltered (gdb_stdlog,
1663 "RC: PTRACE_CONT %s, 0, 0 (resume sibling)\n",
1664 target_pid_to_str (lp->ptid));
1667 memset (&lp->siginfo, 0, sizeof (lp->siginfo));
1669 else if (lp->stopped && debug_linux_nat)
1670 fprintf_unfiltered (gdb_stdlog, "RC: Not resuming sibling %s (has pending)\n",
1671 target_pid_to_str (lp->ptid));
1672 else if (debug_linux_nat)
1673 fprintf_unfiltered (gdb_stdlog, "RC: Not resuming sibling %s (not stopped)\n",
1674 target_pid_to_str (lp->ptid));
1680 resume_clear_callback (struct lwp_info *lp, void *data)
1687 resume_set_callback (struct lwp_info *lp, void *data)
1694 linux_nat_resume (ptid_t ptid, int step, enum target_signal signo)
1696 struct lwp_info *lp;
1699 if (debug_linux_nat)
1700 fprintf_unfiltered (gdb_stdlog,
1701 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1702 step ? "step" : "resume",
1703 target_pid_to_str (ptid),
1704 signo ? strsignal (signo) : "0",
1705 target_pid_to_str (inferior_ptid));
1707 if (target_can_async_p ())
1708 /* Block events while we're here. */
1709 linux_nat_async_events (sigchld_sync);
1711 /* A specific PTID means `step only this process id'. */
1712 resume_all = (PIDGET (ptid) == -1);
1714 if (non_stop && resume_all)
1715 internal_error (__FILE__, __LINE__,
1716 "can't resume all in non-stop mode");
1721 iterate_over_lwps (resume_set_callback, NULL);
1723 iterate_over_lwps (resume_clear_callback, NULL);
1726 /* If PID is -1, it's the current inferior that should be
1727 handled specially. */
1728 if (PIDGET (ptid) == -1)
1729 ptid = inferior_ptid;
1731 lp = find_lwp_pid (ptid);
1732 gdb_assert (lp != NULL);
1734 /* Convert to something the lower layer understands. */
1735 ptid = pid_to_ptid (GET_LWP (lp->ptid));
1737 /* Remember if we're stepping. */
1740 /* Mark this LWP as resumed. */
1743 /* If we have a pending wait status for this thread, there is no
1744 point in resuming the process. But first make sure that
1745 linux_nat_wait won't preemptively handle the event - we
1746 should never take this short-circuit if we are going to
1747 leave LP running, since we have skipped resuming all the
1748 other threads. This bit of code needs to be synchronized
1749 with linux_nat_wait. */
1751 /* In async mode, we never have pending wait status. */
1752 if (target_can_async_p () && lp->status)
1753 internal_error (__FILE__, __LINE__, "Pending status in async mode");
1755 if (lp->status && WIFSTOPPED (lp->status))
1758 struct inferior *inf;
1760 inf = find_inferior_pid (ptid_get_pid (ptid));
1762 saved_signo = target_signal_from_host (WSTOPSIG (lp->status));
1764 /* Defer to common code if we're gaining control of the
1766 if (inf->stop_soon == NO_STOP_QUIETLY
1767 && signal_stop_state (saved_signo) == 0
1768 && signal_print_state (saved_signo) == 0
1769 && signal_pass_state (saved_signo) == 1)
1771 if (debug_linux_nat)
1772 fprintf_unfiltered (gdb_stdlog,
1773 "LLR: Not short circuiting for ignored "
1774 "status 0x%x\n", lp->status);
1776 /* FIXME: What should we do if we are supposed to continue
1777 this thread with a signal? */
1778 gdb_assert (signo == TARGET_SIGNAL_0);
1779 signo = saved_signo;
1786 /* FIXME: What should we do if we are supposed to continue
1787 this thread with a signal? */
1788 gdb_assert (signo == TARGET_SIGNAL_0);
1790 if (debug_linux_nat)
1791 fprintf_unfiltered (gdb_stdlog,
1792 "LLR: Short circuiting for status 0x%x\n",
1798 /* Mark LWP as not stopped to prevent it from being continued by
1803 iterate_over_lwps (resume_callback, NULL);
1805 linux_ops->to_resume (ptid, step, signo);
1806 memset (&lp->siginfo, 0, sizeof (lp->siginfo));
1808 if (debug_linux_nat)
1809 fprintf_unfiltered (gdb_stdlog,
1810 "LLR: %s %s, %s (resume event thread)\n",
1811 step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1812 target_pid_to_str (ptid),
1813 signo ? strsignal (signo) : "0");
1815 if (target_can_async_p ())
1816 target_async (inferior_event_handler, 0);
1819 /* Issue kill to specified lwp. */
1821 static int tkill_failed;
1824 kill_lwp (int lwpid, int signo)
1828 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1829 fails, then we are not using nptl threads and we should be using kill. */
1831 #ifdef HAVE_TKILL_SYSCALL
1834 int ret = syscall (__NR_tkill, lwpid, signo);
1835 if (errno != ENOSYS)
1842 return kill (lwpid, signo);
1845 /* Handle a GNU/Linux extended wait response. If we see a clone
1846 event, we need to add the new LWP to our list (and not report the
1847 trap to higher layers). This function returns non-zero if the
1848 event should be ignored and we should wait again. If STOPPING is
1849 true, the new LWP remains stopped, otherwise it is continued. */
1852 linux_handle_extended_wait (struct lwp_info *lp, int status,
1855 int pid = GET_LWP (lp->ptid);
1856 struct target_waitstatus *ourstatus = &lp->waitstatus;
1857 struct lwp_info *new_lp = NULL;
1858 int event = status >> 16;
1860 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK
1861 || event == PTRACE_EVENT_CLONE)
1863 unsigned long new_pid;
1866 ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid);
1868 /* If we haven't already seen the new PID stop, wait for it now. */
1869 if (! pull_pid_from_list (&stopped_pids, new_pid, &status))
1871 /* The new child has a pending SIGSTOP. We can't affect it until it
1872 hits the SIGSTOP, but we're already attached. */
1873 ret = my_waitpid (new_pid, &status,
1874 (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0);
1876 perror_with_name (_("waiting for new child"));
1877 else if (ret != new_pid)
1878 internal_error (__FILE__, __LINE__,
1879 _("wait returned unexpected PID %d"), ret);
1880 else if (!WIFSTOPPED (status))
1881 internal_error (__FILE__, __LINE__,
1882 _("wait returned unexpected status 0x%x"), status);
1885 ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0);
1887 if (event == PTRACE_EVENT_FORK)
1888 ourstatus->kind = TARGET_WAITKIND_FORKED;
1889 else if (event == PTRACE_EVENT_VFORK)
1890 ourstatus->kind = TARGET_WAITKIND_VFORKED;
1893 struct cleanup *old_chain;
1895 ourstatus->kind = TARGET_WAITKIND_IGNORE;
1896 new_lp = add_lwp (BUILD_LWP (new_pid, GET_PID (inferior_ptid)));
1898 new_lp->stopped = 1;
1900 if (WSTOPSIG (status) != SIGSTOP)
1902 /* This can happen if someone starts sending signals to
1903 the new thread before it gets a chance to run, which
1904 have a lower number than SIGSTOP (e.g. SIGUSR1).
1905 This is an unlikely case, and harder to handle for
1906 fork / vfork than for clone, so we do not try - but
1907 we handle it for clone events here. We'll send
1908 the other signal on to the thread below. */
1910 new_lp->signalled = 1;
1917 /* Add the new thread to GDB's lists as soon as possible
1920 1) the frontend doesn't have to wait for a stop to
1923 2) we tag it with the correct running state. */
1925 /* If the thread_db layer is active, let it know about
1926 this new thread, and add it to GDB's list. */
1927 if (!thread_db_attach_lwp (new_lp->ptid))
1929 /* We're not using thread_db. Add it to GDB's
1931 target_post_attach (GET_LWP (new_lp->ptid));
1932 add_thread (new_lp->ptid);
1937 set_running (new_lp->ptid, 1);
1938 set_executing (new_lp->ptid, 1);
1944 new_lp->stopped = 0;
1945 new_lp->resumed = 1;
1946 ptrace (PTRACE_CONT, new_pid, 0,
1947 status ? WSTOPSIG (status) : 0);
1950 if (debug_linux_nat)
1951 fprintf_unfiltered (gdb_stdlog,
1952 "LHEW: Got clone event from LWP %ld, resuming\n",
1953 GET_LWP (lp->ptid));
1954 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
1962 if (event == PTRACE_EVENT_EXEC)
1964 ourstatus->kind = TARGET_WAITKIND_EXECD;
1965 ourstatus->value.execd_pathname
1966 = xstrdup (linux_child_pid_to_exec_file (pid));
1968 if (linux_parent_pid)
1970 detach_breakpoints (linux_parent_pid);
1971 ptrace (PTRACE_DETACH, linux_parent_pid, 0, 0);
1973 linux_parent_pid = 0;
1976 /* At this point, all inserted breakpoints are gone. Doing this
1977 as soon as we detect an exec prevents the badness of deleting
1978 a breakpoint writing the current "shadow contents" to lift
1979 the bp. That shadow is NOT valid after an exec.
1981 Note that we have to do this after the detach_breakpoints
1982 call above, otherwise breakpoints wouldn't be lifted from the
1983 parent on a vfork, because detach_breakpoints would think
1984 that breakpoints are not inserted. */
1985 mark_breakpoints_out ();
1989 internal_error (__FILE__, __LINE__,
1990 _("unknown ptrace event %d"), event);
1993 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
1997 wait_lwp (struct lwp_info *lp)
2001 int thread_dead = 0;
2003 gdb_assert (!lp->stopped);
2004 gdb_assert (lp->status == 0);
2006 pid = my_waitpid (GET_LWP (lp->ptid), &status, 0);
2007 if (pid == -1 && errno == ECHILD)
2009 pid = my_waitpid (GET_LWP (lp->ptid), &status, __WCLONE);
2010 if (pid == -1 && errno == ECHILD)
2012 /* The thread has previously exited. We need to delete it
2013 now because, for some vendor 2.4 kernels with NPTL
2014 support backported, there won't be an exit event unless
2015 it is the main thread. 2.6 kernels will report an exit
2016 event for each thread that exits, as expected. */
2018 if (debug_linux_nat)
2019 fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
2020 target_pid_to_str (lp->ptid));
2026 gdb_assert (pid == GET_LWP (lp->ptid));
2028 if (debug_linux_nat)
2030 fprintf_unfiltered (gdb_stdlog,
2031 "WL: waitpid %s received %s\n",
2032 target_pid_to_str (lp->ptid),
2033 status_to_str (status));
2037 /* Check if the thread has exited. */
2038 if (WIFEXITED (status) || WIFSIGNALED (status))
2041 if (debug_linux_nat)
2042 fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n",
2043 target_pid_to_str (lp->ptid));
2052 gdb_assert (WIFSTOPPED (status));
2054 /* Handle GNU/Linux's extended waitstatus for trace events. */
2055 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
2057 if (debug_linux_nat)
2058 fprintf_unfiltered (gdb_stdlog,
2059 "WL: Handling extended status 0x%06x\n",
2061 if (linux_handle_extended_wait (lp, status, 1))
2062 return wait_lwp (lp);
2068 /* Save the most recent siginfo for LP. This is currently only called
2069 for SIGTRAP; some ports use the si_addr field for
2070 target_stopped_data_address. In the future, it may also be used to
2071 restore the siginfo of requeued signals. */
2074 save_siginfo (struct lwp_info *lp)
2077 ptrace (PTRACE_GETSIGINFO, GET_LWP (lp->ptid),
2078 (PTRACE_TYPE_ARG3) 0, &lp->siginfo);
2081 memset (&lp->siginfo, 0, sizeof (lp->siginfo));
2084 /* Send a SIGSTOP to LP. */
2087 stop_callback (struct lwp_info *lp, void *data)
2089 if (!lp->stopped && !lp->signalled)
2093 if (debug_linux_nat)
2095 fprintf_unfiltered (gdb_stdlog,
2096 "SC: kill %s **<SIGSTOP>**\n",
2097 target_pid_to_str (lp->ptid));
2100 ret = kill_lwp (GET_LWP (lp->ptid), SIGSTOP);
2101 if (debug_linux_nat)
2103 fprintf_unfiltered (gdb_stdlog,
2104 "SC: lwp kill %d %s\n",
2106 errno ? safe_strerror (errno) : "ERRNO-OK");
2110 gdb_assert (lp->status == 0);
2116 /* Return non-zero if LWP PID has a pending SIGINT. */
2119 linux_nat_has_pending_sigint (int pid)
2121 sigset_t pending, blocked, ignored;
2124 linux_proc_pending_signals (pid, &pending, &blocked, &ignored);
2126 if (sigismember (&pending, SIGINT)
2127 && !sigismember (&ignored, SIGINT))
2133 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2136 set_ignore_sigint (struct lwp_info *lp, void *data)
2138 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2139 flag to consume the next one. */
2140 if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status)
2141 && WSTOPSIG (lp->status) == SIGINT)
2144 lp->ignore_sigint = 1;
2149 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2150 This function is called after we know the LWP has stopped; if the LWP
2151 stopped before the expected SIGINT was delivered, then it will never have
2152 arrived. Also, if the signal was delivered to a shared queue and consumed
2153 by a different thread, it will never be delivered to this LWP. */
2156 maybe_clear_ignore_sigint (struct lwp_info *lp)
2158 if (!lp->ignore_sigint)
2161 if (!linux_nat_has_pending_sigint (GET_LWP (lp->ptid)))
2163 if (debug_linux_nat)
2164 fprintf_unfiltered (gdb_stdlog,
2165 "MCIS: Clearing bogus flag for %s\n",
2166 target_pid_to_str (lp->ptid));
2167 lp->ignore_sigint = 0;
2171 /* Wait until LP is stopped. */
2174 stop_wait_callback (struct lwp_info *lp, void *data)
2180 status = wait_lwp (lp);
2184 if (lp->ignore_sigint && WIFSTOPPED (status)
2185 && WSTOPSIG (status) == SIGINT)
2187 lp->ignore_sigint = 0;
2190 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2191 if (debug_linux_nat)
2192 fprintf_unfiltered (gdb_stdlog,
2193 "PTRACE_CONT %s, 0, 0 (%s) (discarding SIGINT)\n",
2194 target_pid_to_str (lp->ptid),
2195 errno ? safe_strerror (errno) : "OK");
2197 return stop_wait_callback (lp, NULL);
2200 maybe_clear_ignore_sigint (lp);
2202 if (WSTOPSIG (status) != SIGSTOP)
2204 if (WSTOPSIG (status) == SIGTRAP)
2206 /* If a LWP other than the LWP that we're reporting an
2207 event for has hit a GDB breakpoint (as opposed to
2208 some random trap signal), then just arrange for it to
2209 hit it again later. We don't keep the SIGTRAP status
2210 and don't forward the SIGTRAP signal to the LWP. We
2211 will handle the current event, eventually we will
2212 resume all LWPs, and this one will get its breakpoint
2215 If we do not do this, then we run the risk that the
2216 user will delete or disable the breakpoint, but the
2217 thread will have already tripped on it. */
2219 /* Save the trap's siginfo in case we need it later. */
2222 /* Now resume this LWP and get the SIGSTOP event. */
2224 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2225 if (debug_linux_nat)
2227 fprintf_unfiltered (gdb_stdlog,
2228 "PTRACE_CONT %s, 0, 0 (%s)\n",
2229 target_pid_to_str (lp->ptid),
2230 errno ? safe_strerror (errno) : "OK");
2232 fprintf_unfiltered (gdb_stdlog,
2233 "SWC: Candidate SIGTRAP event in %s\n",
2234 target_pid_to_str (lp->ptid));
2236 /* Hold this event/waitstatus while we check to see if
2237 there are any more (we still want to get that SIGSTOP). */
2238 stop_wait_callback (lp, NULL);
2240 if (target_can_async_p ())
2242 /* Don't leave a pending wait status in async mode.
2243 Retrigger the breakpoint. */
2244 if (!cancel_breakpoint (lp))
2246 /* There was no gdb breakpoint set at pc. Put
2247 the event back in the queue. */
2248 if (debug_linux_nat)
2249 fprintf_unfiltered (gdb_stdlog, "\
2250 SWC: leaving SIGTRAP in local queue of %s\n", target_pid_to_str (lp->ptid));
2251 push_waitpid (GET_LWP (lp->ptid),
2252 W_STOPCODE (SIGTRAP),
2253 lp->cloned ? __WCLONE : 0);
2258 /* Hold the SIGTRAP for handling by
2260 /* If there's another event, throw it back into the
2264 if (debug_linux_nat)
2265 fprintf_unfiltered (gdb_stdlog,
2266 "SWC: kill %s, %s\n",
2267 target_pid_to_str (lp->ptid),
2268 status_to_str ((int) status));
2269 kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (lp->status));
2271 /* Save the sigtrap event. */
2272 lp->status = status;
2278 /* The thread was stopped with a signal other than
2279 SIGSTOP, and didn't accidentally trip a breakpoint. */
2281 if (debug_linux_nat)
2283 fprintf_unfiltered (gdb_stdlog,
2284 "SWC: Pending event %s in %s\n",
2285 status_to_str ((int) status),
2286 target_pid_to_str (lp->ptid));
2288 /* Now resume this LWP and get the SIGSTOP event. */
2290 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2291 if (debug_linux_nat)
2292 fprintf_unfiltered (gdb_stdlog,
2293 "SWC: PTRACE_CONT %s, 0, 0 (%s)\n",
2294 target_pid_to_str (lp->ptid),
2295 errno ? safe_strerror (errno) : "OK");
2297 /* Hold this event/waitstatus while we check to see if
2298 there are any more (we still want to get that SIGSTOP). */
2299 stop_wait_callback (lp, NULL);
2301 /* If the lp->status field is still empty, use it to
2302 hold this event. If not, then this event must be
2303 returned to the event queue of the LWP. */
2304 if (lp->status || target_can_async_p ())
2306 if (debug_linux_nat)
2308 fprintf_unfiltered (gdb_stdlog,
2309 "SWC: kill %s, %s\n",
2310 target_pid_to_str (lp->ptid),
2311 status_to_str ((int) status));
2313 kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (status));
2316 lp->status = status;
2322 /* We caught the SIGSTOP that we intended to catch, so
2323 there's no SIGSTOP pending. */
2332 /* Return non-zero if LP has a wait status pending. */
2335 status_callback (struct lwp_info *lp, void *data)
2337 /* Only report a pending wait status if we pretend that this has
2338 indeed been resumed. */
2339 return (lp->status != 0 && lp->resumed);
2342 /* Return non-zero if LP isn't stopped. */
2345 running_callback (struct lwp_info *lp, void *data)
2347 return (lp->stopped == 0 || (lp->status != 0 && lp->resumed));
2350 /* Count the LWP's that have had events. */
2353 count_events_callback (struct lwp_info *lp, void *data)
2357 gdb_assert (count != NULL);
2359 /* Count only resumed LWPs that have a SIGTRAP event pending. */
2360 if (lp->status != 0 && lp->resumed
2361 && WIFSTOPPED (lp->status) && WSTOPSIG (lp->status) == SIGTRAP)
2367 /* Select the LWP (if any) that is currently being single-stepped. */
2370 select_singlestep_lwp_callback (struct lwp_info *lp, void *data)
2372 if (lp->step && lp->status != 0)
2378 /* Select the Nth LWP that has had a SIGTRAP event. */
2381 select_event_lwp_callback (struct lwp_info *lp, void *data)
2383 int *selector = data;
2385 gdb_assert (selector != NULL);
2387 /* Select only resumed LWPs that have a SIGTRAP event pending. */
2388 if (lp->status != 0 && lp->resumed
2389 && WIFSTOPPED (lp->status) && WSTOPSIG (lp->status) == SIGTRAP)
2390 if ((*selector)-- == 0)
2397 cancel_breakpoint (struct lwp_info *lp)
2399 /* Arrange for a breakpoint to be hit again later. We don't keep
2400 the SIGTRAP status and don't forward the SIGTRAP signal to the
2401 LWP. We will handle the current event, eventually we will resume
2402 this LWP, and this breakpoint will trap again.
2404 If we do not do this, then we run the risk that the user will
2405 delete or disable the breakpoint, but the LWP will have already
2408 struct regcache *regcache = get_thread_regcache (lp->ptid);
2409 struct gdbarch *gdbarch = get_regcache_arch (regcache);
2412 pc = regcache_read_pc (regcache) - gdbarch_decr_pc_after_break (gdbarch);
2413 if (breakpoint_inserted_here_p (pc))
2415 if (debug_linux_nat)
2416 fprintf_unfiltered (gdb_stdlog,
2417 "CB: Push back breakpoint for %s\n",
2418 target_pid_to_str (lp->ptid));
2420 /* Back up the PC if necessary. */
2421 if (gdbarch_decr_pc_after_break (gdbarch))
2422 regcache_write_pc (regcache, pc);
2430 cancel_breakpoints_callback (struct lwp_info *lp, void *data)
2432 struct lwp_info *event_lp = data;
2434 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
2438 /* If a LWP other than the LWP that we're reporting an event for has
2439 hit a GDB breakpoint (as opposed to some random trap signal),
2440 then just arrange for it to hit it again later. We don't keep
2441 the SIGTRAP status and don't forward the SIGTRAP signal to the
2442 LWP. We will handle the current event, eventually we will resume
2443 all LWPs, and this one will get its breakpoint trap again.
2445 If we do not do this, then we run the risk that the user will
2446 delete or disable the breakpoint, but the LWP will have already
2450 && WIFSTOPPED (lp->status) && WSTOPSIG (lp->status) == SIGTRAP
2451 && cancel_breakpoint (lp))
2452 /* Throw away the SIGTRAP. */
2458 /* Select one LWP out of those that have events pending. */
2461 select_event_lwp (struct lwp_info **orig_lp, int *status)
2464 int random_selector;
2465 struct lwp_info *event_lp;
2467 /* Record the wait status for the original LWP. */
2468 (*orig_lp)->status = *status;
2470 /* Give preference to any LWP that is being single-stepped. */
2471 event_lp = iterate_over_lwps (select_singlestep_lwp_callback, NULL);
2472 if (event_lp != NULL)
2474 if (debug_linux_nat)
2475 fprintf_unfiltered (gdb_stdlog,
2476 "SEL: Select single-step %s\n",
2477 target_pid_to_str (event_lp->ptid));
2481 /* No single-stepping LWP. Select one at random, out of those
2482 which have had SIGTRAP events. */
2484 /* First see how many SIGTRAP events we have. */
2485 iterate_over_lwps (count_events_callback, &num_events);
2487 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
2488 random_selector = (int)
2489 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
2491 if (debug_linux_nat && num_events > 1)
2492 fprintf_unfiltered (gdb_stdlog,
2493 "SEL: Found %d SIGTRAP events, selecting #%d\n",
2494 num_events, random_selector);
2496 event_lp = iterate_over_lwps (select_event_lwp_callback,
2500 if (event_lp != NULL)
2502 /* Switch the event LWP. */
2503 *orig_lp = event_lp;
2504 *status = event_lp->status;
2507 /* Flush the wait status for the event LWP. */
2508 (*orig_lp)->status = 0;
2511 /* Return non-zero if LP has been resumed. */
2514 resumed_callback (struct lwp_info *lp, void *data)
2519 /* Stop an active thread, verify it still exists, then resume it. */
2522 stop_and_resume_callback (struct lwp_info *lp, void *data)
2524 struct lwp_info *ptr;
2526 if (!lp->stopped && !lp->signalled)
2528 stop_callback (lp, NULL);
2529 stop_wait_callback (lp, NULL);
2530 /* Resume if the lwp still exists. */
2531 for (ptr = lwp_list; ptr; ptr = ptr->next)
2534 resume_callback (lp, NULL);
2535 resume_set_callback (lp, NULL);
2541 /* Check if we should go on and pass this event to common code.
2542 Return the affected lwp if we are, or NULL otherwise. */
2543 static struct lwp_info *
2544 linux_nat_filter_event (int lwpid, int status, int options)
2546 struct lwp_info *lp;
2548 lp = find_lwp_pid (pid_to_ptid (lwpid));
2550 /* Check for stop events reported by a process we didn't already
2551 know about - anything not already in our LWP list.
2553 If we're expecting to receive stopped processes after
2554 fork, vfork, and clone events, then we'll just add the
2555 new one to our list and go back to waiting for the event
2556 to be reported - the stopped process might be returned
2557 from waitpid before or after the event is. */
2558 if (WIFSTOPPED (status) && !lp)
2560 linux_record_stopped_pid (lwpid, status);
2564 /* Make sure we don't report an event for the exit of an LWP not in
2565 our list, i.e. not part of the current process. This can happen
2566 if we detach from a program we original forked and then it
2568 if (!WIFSTOPPED (status) && !lp)
2571 /* NOTE drow/2003-06-17: This code seems to be meant for debugging
2572 CLONE_PTRACE processes which do not use the thread library -
2573 otherwise we wouldn't find the new LWP this way. That doesn't
2574 currently work, and the following code is currently unreachable
2575 due to the two blocks above. If it's fixed some day, this code
2576 should be broken out into a function so that we can also pick up
2577 LWPs from the new interface. */
2580 lp = add_lwp (BUILD_LWP (lwpid, GET_PID (inferior_ptid)));
2581 if (options & __WCLONE)
2584 gdb_assert (WIFSTOPPED (status)
2585 && WSTOPSIG (status) == SIGSTOP);
2588 if (!in_thread_list (inferior_ptid))
2590 inferior_ptid = BUILD_LWP (GET_PID (inferior_ptid),
2591 GET_PID (inferior_ptid));
2592 add_thread (inferior_ptid);
2595 add_thread (lp->ptid);
2598 /* Save the trap's siginfo in case we need it later. */
2599 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP)
2602 /* Handle GNU/Linux's extended waitstatus for trace events. */
2603 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
2605 if (debug_linux_nat)
2606 fprintf_unfiltered (gdb_stdlog,
2607 "LLW: Handling extended status 0x%06x\n",
2609 if (linux_handle_extended_wait (lp, status, 0))
2613 /* Check if the thread has exited. */
2614 if ((WIFEXITED (status) || WIFSIGNALED (status)) && num_lwps > 1)
2616 /* If this is the main thread, we must stop all threads and
2617 verify if they are still alive. This is because in the nptl
2618 thread model, there is no signal issued for exiting LWPs
2619 other than the main thread. We only get the main thread exit
2620 signal once all child threads have already exited. If we
2621 stop all the threads and use the stop_wait_callback to check
2622 if they have exited we can determine whether this signal
2623 should be ignored or whether it means the end of the debugged
2624 application, regardless of which threading model is being
2626 if (GET_PID (lp->ptid) == GET_LWP (lp->ptid))
2629 iterate_over_lwps (stop_and_resume_callback, NULL);
2632 if (debug_linux_nat)
2633 fprintf_unfiltered (gdb_stdlog,
2634 "LLW: %s exited.\n",
2635 target_pid_to_str (lp->ptid));
2639 /* If there is at least one more LWP, then the exit signal was
2640 not the end of the debugged application and should be
2646 /* Check if the current LWP has previously exited. In the nptl
2647 thread model, LWPs other than the main thread do not issue
2648 signals when they exit so we must check whenever the thread has
2649 stopped. A similar check is made in stop_wait_callback(). */
2650 if (num_lwps > 1 && !linux_nat_thread_alive (lp->ptid))
2652 if (debug_linux_nat)
2653 fprintf_unfiltered (gdb_stdlog,
2654 "LLW: %s exited.\n",
2655 target_pid_to_str (lp->ptid));
2659 /* Make sure there is at least one thread running. */
2660 gdb_assert (iterate_over_lwps (running_callback, NULL));
2662 /* Discard the event. */
2666 /* Make sure we don't report a SIGSTOP that we sent ourselves in
2667 an attempt to stop an LWP. */
2669 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP)
2671 if (debug_linux_nat)
2672 fprintf_unfiltered (gdb_stdlog,
2673 "LLW: Delayed SIGSTOP caught for %s.\n",
2674 target_pid_to_str (lp->ptid));
2676 /* This is a delayed SIGSTOP. */
2679 registers_changed ();
2681 linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)),
2682 lp->step, TARGET_SIGNAL_0);
2683 if (debug_linux_nat)
2684 fprintf_unfiltered (gdb_stdlog,
2685 "LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
2687 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2688 target_pid_to_str (lp->ptid));
2691 gdb_assert (lp->resumed);
2693 /* Discard the event. */
2697 /* Make sure we don't report a SIGINT that we have already displayed
2698 for another thread. */
2699 if (lp->ignore_sigint
2700 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT)
2702 if (debug_linux_nat)
2703 fprintf_unfiltered (gdb_stdlog,
2704 "LLW: Delayed SIGINT caught for %s.\n",
2705 target_pid_to_str (lp->ptid));
2707 /* This is a delayed SIGINT. */
2708 lp->ignore_sigint = 0;
2710 registers_changed ();
2711 linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)),
2712 lp->step, TARGET_SIGNAL_0);
2713 if (debug_linux_nat)
2714 fprintf_unfiltered (gdb_stdlog,
2715 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
2717 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2718 target_pid_to_str (lp->ptid));
2721 gdb_assert (lp->resumed);
2723 /* Discard the event. */
2727 /* An interesting event. */
2732 /* Get the events stored in the pipe into the local queue, so they are
2733 accessible to queued_waitpid. We need to do this, since it is not
2734 always the case that the event at the head of the pipe is the event
2738 pipe_to_local_event_queue (void)
2740 if (debug_linux_nat_async)
2741 fprintf_unfiltered (gdb_stdlog,
2742 "PTLEQ: linux_nat_num_queued_events(%d)\n",
2743 linux_nat_num_queued_events);
2744 while (linux_nat_num_queued_events)
2746 int lwpid, status, options;
2747 lwpid = linux_nat_event_pipe_pop (&status, &options);
2748 gdb_assert (lwpid > 0);
2749 push_waitpid (lwpid, status, options);
2753 /* Get the unprocessed events stored in the local queue back into the
2754 pipe, so the event loop realizes there's something else to
2758 local_event_queue_to_pipe (void)
2760 struct waitpid_result *w = waitpid_queue;
2763 struct waitpid_result *next = w->next;
2764 linux_nat_event_pipe_push (w->pid,
2770 waitpid_queue = NULL;
2772 if (debug_linux_nat_async)
2773 fprintf_unfiltered (gdb_stdlog,
2774 "LEQTP: linux_nat_num_queued_events(%d)\n",
2775 linux_nat_num_queued_events);
2779 linux_nat_wait (struct target_ops *ops,
2780 ptid_t ptid, struct target_waitstatus *ourstatus)
2782 struct lwp_info *lp = NULL;
2785 pid_t pid = PIDGET (ptid);
2787 if (debug_linux_nat_async)
2788 fprintf_unfiltered (gdb_stdlog, "LLW: enter\n");
2790 /* The first time we get here after starting a new inferior, we may
2791 not have added it to the LWP list yet - this is the earliest
2792 moment at which we know its PID. */
2795 gdb_assert (!is_lwp (inferior_ptid));
2797 /* Upgrade the main thread's ptid. */
2798 thread_change_ptid (inferior_ptid,
2799 BUILD_LWP (GET_PID (inferior_ptid),
2800 GET_PID (inferior_ptid)));
2802 lp = add_lwp (inferior_ptid);
2806 /* Block events while we're here. */
2807 linux_nat_async_events (sigchld_sync);
2811 /* Make sure there is at least one LWP that has been resumed. */
2812 gdb_assert (iterate_over_lwps (resumed_callback, NULL));
2814 /* First check if there is a LWP with a wait status pending. */
2817 /* Any LWP that's been resumed will do. */
2818 lp = iterate_over_lwps (status_callback, NULL);
2821 if (target_can_async_p ())
2822 internal_error (__FILE__, __LINE__,
2823 "Found an LWP with a pending status in async mode.");
2825 status = lp->status;
2828 if (debug_linux_nat && status)
2829 fprintf_unfiltered (gdb_stdlog,
2830 "LLW: Using pending wait status %s for %s.\n",
2831 status_to_str (status),
2832 target_pid_to_str (lp->ptid));
2835 /* But if we don't find one, we'll have to wait, and check both
2836 cloned and uncloned processes. We start with the cloned
2838 options = __WCLONE | WNOHANG;
2840 else if (is_lwp (ptid))
2842 if (debug_linux_nat)
2843 fprintf_unfiltered (gdb_stdlog,
2844 "LLW: Waiting for specific LWP %s.\n",
2845 target_pid_to_str (ptid));
2847 /* We have a specific LWP to check. */
2848 lp = find_lwp_pid (ptid);
2850 status = lp->status;
2853 if (debug_linux_nat && status)
2854 fprintf_unfiltered (gdb_stdlog,
2855 "LLW: Using pending wait status %s for %s.\n",
2856 status_to_str (status),
2857 target_pid_to_str (lp->ptid));
2859 /* If we have to wait, take into account whether PID is a cloned
2860 process or not. And we have to convert it to something that
2861 the layer beneath us can understand. */
2862 options = lp->cloned ? __WCLONE : 0;
2863 pid = GET_LWP (ptid);
2866 if (status && lp->signalled)
2868 /* A pending SIGSTOP may interfere with the normal stream of
2869 events. In a typical case where interference is a problem,
2870 we have a SIGSTOP signal pending for LWP A while
2871 single-stepping it, encounter an event in LWP B, and take the
2872 pending SIGSTOP while trying to stop LWP A. After processing
2873 the event in LWP B, LWP A is continued, and we'll never see
2874 the SIGTRAP associated with the last time we were
2875 single-stepping LWP A. */
2877 /* Resume the thread. It should halt immediately returning the
2879 registers_changed ();
2880 linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)),
2881 lp->step, TARGET_SIGNAL_0);
2882 if (debug_linux_nat)
2883 fprintf_unfiltered (gdb_stdlog,
2884 "LLW: %s %s, 0, 0 (expect SIGSTOP)\n",
2885 lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2886 target_pid_to_str (lp->ptid));
2888 gdb_assert (lp->resumed);
2890 /* This should catch the pending SIGSTOP. */
2891 stop_wait_callback (lp, NULL);
2894 if (!target_can_async_p ())
2896 /* Causes SIGINT to be passed on to the attached process. */
2904 if (target_can_async_p ())
2905 /* In async mode, don't ever block. Only look at the locally
2907 lwpid = queued_waitpid (pid, &status, options);
2909 lwpid = my_waitpid (pid, &status, options);
2913 gdb_assert (pid == -1 || lwpid == pid);
2915 if (debug_linux_nat)
2917 fprintf_unfiltered (gdb_stdlog,
2918 "LLW: waitpid %ld received %s\n",
2919 (long) lwpid, status_to_str (status));
2922 lp = linux_nat_filter_event (lwpid, status, options);
2925 /* A discarded event. */
2935 /* Alternate between checking cloned and uncloned processes. */
2936 options ^= __WCLONE;
2938 /* And every time we have checked both:
2939 In async mode, return to event loop;
2940 In sync mode, suspend waiting for a SIGCHLD signal. */
2941 if (options & __WCLONE)
2943 if (target_can_async_p ())
2945 /* No interesting event. */
2946 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2948 /* Get ready for the next event. */
2949 target_async (inferior_event_handler, 0);
2951 if (debug_linux_nat_async)
2952 fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
2954 return minus_one_ptid;
2957 sigsuspend (&suspend_mask);
2961 /* We shouldn't end up here unless we want to try again. */
2962 gdb_assert (status == 0);
2965 if (!target_can_async_p ())
2966 clear_sigint_trap ();
2970 /* Don't report signals that GDB isn't interested in, such as
2971 signals that are neither printed nor stopped upon. Stopping all
2972 threads can be a bit time-consuming so if we want decent
2973 performance with heavily multi-threaded programs, especially when
2974 they're using a high frequency timer, we'd better avoid it if we
2977 if (WIFSTOPPED (status))
2979 int signo = target_signal_from_host (WSTOPSIG (status));
2980 struct inferior *inf;
2982 inf = find_inferior_pid (ptid_get_pid (lp->ptid));
2985 /* Defer to common code if we get a signal while
2986 single-stepping, since that may need special care, e.g. to
2987 skip the signal handler, or, if we're gaining control of the
2990 && inf->stop_soon == NO_STOP_QUIETLY
2991 && signal_stop_state (signo) == 0
2992 && signal_print_state (signo) == 0
2993 && signal_pass_state (signo) == 1)
2995 /* FIMXE: kettenis/2001-06-06: Should we resume all threads
2996 here? It is not clear we should. GDB may not expect
2997 other threads to run. On the other hand, not resuming
2998 newly attached threads may cause an unwanted delay in
2999 getting them running. */
3000 registers_changed ();
3001 linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)),
3003 if (debug_linux_nat)
3004 fprintf_unfiltered (gdb_stdlog,
3005 "LLW: %s %s, %s (preempt 'handle')\n",
3007 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3008 target_pid_to_str (lp->ptid),
3009 signo ? strsignal (signo) : "0");
3017 /* Only do the below in all-stop, as we currently use SIGINT
3018 to implement target_stop (see linux_nat_stop) in
3020 if (signo == TARGET_SIGNAL_INT && signal_pass_state (signo) == 0)
3022 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3023 forwarded to the entire process group, that is, all LWPs
3024 will receive it - unless they're using CLONE_THREAD to
3025 share signals. Since we only want to report it once, we
3026 mark it as ignored for all LWPs except this one. */
3027 iterate_over_lwps (set_ignore_sigint, NULL);
3028 lp->ignore_sigint = 0;
3031 maybe_clear_ignore_sigint (lp);
3035 /* This LWP is stopped now. */
3038 if (debug_linux_nat)
3039 fprintf_unfiltered (gdb_stdlog, "LLW: Candidate event %s in %s.\n",
3040 status_to_str (status), target_pid_to_str (lp->ptid));
3044 /* Now stop all other LWP's ... */
3045 iterate_over_lwps (stop_callback, NULL);
3047 /* ... and wait until all of them have reported back that
3048 they're no longer running. */
3049 iterate_over_lwps (stop_wait_callback, NULL);
3051 /* If we're not waiting for a specific LWP, choose an event LWP
3052 from among those that have had events. Giving equal priority
3053 to all LWPs that have had events helps prevent
3056 select_event_lwp (&lp, &status);
3059 /* Now that we've selected our final event LWP, cancel any
3060 breakpoints in other LWPs that have hit a GDB breakpoint. See
3061 the comment in cancel_breakpoints_callback to find out why. */
3062 iterate_over_lwps (cancel_breakpoints_callback, lp);
3064 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP)
3066 if (debug_linux_nat)
3067 fprintf_unfiltered (gdb_stdlog,
3068 "LLW: trap ptid is %s.\n",
3069 target_pid_to_str (lp->ptid));
3072 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
3074 *ourstatus = lp->waitstatus;
3075 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
3078 store_waitstatus (ourstatus, status);
3080 /* Get ready for the next event. */
3081 if (target_can_async_p ())
3082 target_async (inferior_event_handler, 0);
3084 if (debug_linux_nat_async)
3085 fprintf_unfiltered (gdb_stdlog, "LLW: exit\n");
3091 kill_callback (struct lwp_info *lp, void *data)
3094 ptrace (PTRACE_KILL, GET_LWP (lp->ptid), 0, 0);
3095 if (debug_linux_nat)
3096 fprintf_unfiltered (gdb_stdlog,
3097 "KC: PTRACE_KILL %s, 0, 0 (%s)\n",
3098 target_pid_to_str (lp->ptid),
3099 errno ? safe_strerror (errno) : "OK");
3105 kill_wait_callback (struct lwp_info *lp, void *data)
3109 /* We must make sure that there are no pending events (delayed
3110 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3111 program doesn't interfere with any following debugging session. */
3113 /* For cloned processes we must check both with __WCLONE and
3114 without, since the exit status of a cloned process isn't reported
3120 pid = my_waitpid (GET_LWP (lp->ptid), NULL, __WCLONE);
3121 if (pid != (pid_t) -1)
3123 if (debug_linux_nat)
3124 fprintf_unfiltered (gdb_stdlog,
3125 "KWC: wait %s received unknown.\n",
3126 target_pid_to_str (lp->ptid));
3127 /* The Linux kernel sometimes fails to kill a thread
3128 completely after PTRACE_KILL; that goes from the stop
3129 point in do_fork out to the one in
3130 get_signal_to_deliever and waits again. So kill it
3132 kill_callback (lp, NULL);
3135 while (pid == GET_LWP (lp->ptid));
3137 gdb_assert (pid == -1 && errno == ECHILD);
3142 pid = my_waitpid (GET_LWP (lp->ptid), NULL, 0);
3143 if (pid != (pid_t) -1)
3145 if (debug_linux_nat)
3146 fprintf_unfiltered (gdb_stdlog,
3147 "KWC: wait %s received unk.\n",
3148 target_pid_to_str (lp->ptid));
3149 /* See the call to kill_callback above. */
3150 kill_callback (lp, NULL);
3153 while (pid == GET_LWP (lp->ptid));
3155 gdb_assert (pid == -1 && errno == ECHILD);
3160 linux_nat_kill (void)
3162 struct target_waitstatus last;
3166 if (target_can_async_p ())
3167 target_async (NULL, 0);
3169 /* If we're stopped while forking and we haven't followed yet,
3170 kill the other task. We need to do this first because the
3171 parent will be sleeping if this is a vfork. */
3173 get_last_target_status (&last_ptid, &last);
3175 if (last.kind == TARGET_WAITKIND_FORKED
3176 || last.kind == TARGET_WAITKIND_VFORKED)
3178 ptrace (PT_KILL, PIDGET (last.value.related_pid), 0, 0);
3182 if (forks_exist_p ())
3184 linux_fork_killall ();
3185 drain_queued_events (-1);
3189 /* Stop all threads before killing them, since ptrace requires
3190 that the thread is stopped to sucessfully PTRACE_KILL. */
3191 iterate_over_lwps (stop_callback, NULL);
3192 /* ... and wait until all of them have reported back that
3193 they're no longer running. */
3194 iterate_over_lwps (stop_wait_callback, NULL);
3196 /* Kill all LWP's ... */
3197 iterate_over_lwps (kill_callback, NULL);
3199 /* ... and wait until we've flushed all events. */
3200 iterate_over_lwps (kill_wait_callback, NULL);
3203 target_mourn_inferior ();
3207 linux_nat_mourn_inferior (struct target_ops *ops)
3209 /* Destroy LWP info; it's no longer valid. */
3212 if (! forks_exist_p ())
3214 /* Normal case, no other forks available. */
3215 if (target_can_async_p ())
3216 linux_nat_async (NULL, 0);
3217 linux_ops->to_mourn_inferior (ops);
3220 /* Multi-fork case. The current inferior_ptid has exited, but
3221 there are other viable forks to debug. Delete the exiting
3222 one and context-switch to the first available. */
3223 linux_fork_mourn_inferior ();
3227 linux_nat_xfer_partial (struct target_ops *ops, enum target_object object,
3228 const char *annex, gdb_byte *readbuf,
3229 const gdb_byte *writebuf,
3230 ULONGEST offset, LONGEST len)
3232 struct cleanup *old_chain = save_inferior_ptid ();
3235 if (is_lwp (inferior_ptid))
3236 inferior_ptid = pid_to_ptid (GET_LWP (inferior_ptid));
3238 xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf,
3241 do_cleanups (old_chain);
3246 linux_nat_thread_alive (ptid_t ptid)
3250 gdb_assert (is_lwp (ptid));
3252 /* Send signal 0 instead of anything ptrace, because ptracing a
3253 running thread errors out claiming that the thread doesn't
3255 err = kill_lwp (GET_LWP (ptid), 0);
3257 if (debug_linux_nat)
3258 fprintf_unfiltered (gdb_stdlog,
3259 "LLTA: KILL(SIG0) %s (%s)\n",
3260 target_pid_to_str (ptid),
3261 err ? safe_strerror (err) : "OK");
3270 linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid)
3272 static char buf[64];
3275 && ((lwp_list && lwp_list->next)
3276 || GET_PID (ptid) != GET_LWP (ptid)))
3278 snprintf (buf, sizeof (buf), "LWP %ld", GET_LWP (ptid));
3282 return normal_pid_to_str (ptid);
3286 sigchld_handler (int signo)
3288 if (target_async_permitted
3289 && linux_nat_async_events_state != sigchld_sync
3290 && signo == SIGCHLD)
3291 /* It is *always* a bug to hit this. */
3292 internal_error (__FILE__, __LINE__,
3293 "sigchld_handler called when async events are enabled");
3295 /* Do nothing. The only reason for this handler is that it allows
3296 us to use sigsuspend in linux_nat_wait above to wait for the
3297 arrival of a SIGCHLD. */
3300 /* Accepts an integer PID; Returns a string representing a file that
3301 can be opened to get the symbols for the child process. */
3304 linux_child_pid_to_exec_file (int pid)
3306 char *name1, *name2;
3308 name1 = xmalloc (MAXPATHLEN);
3309 name2 = xmalloc (MAXPATHLEN);
3310 make_cleanup (xfree, name1);
3311 make_cleanup (xfree, name2);
3312 memset (name2, 0, MAXPATHLEN);
3314 sprintf (name1, "/proc/%d/exe", pid);
3315 if (readlink (name1, name2, MAXPATHLEN) > 0)
3321 /* Service function for corefiles and info proc. */
3324 read_mapping (FILE *mapfile,
3329 char *device, long long *inode, char *filename)
3331 int ret = fscanf (mapfile, "%llx-%llx %s %llx %s %llx",
3332 addr, endaddr, permissions, offset, device, inode);
3335 if (ret > 0 && ret != EOF)
3337 /* Eat everything up to EOL for the filename. This will prevent
3338 weird filenames (such as one with embedded whitespace) from
3339 confusing this code. It also makes this code more robust in
3340 respect to annotations the kernel may add after the filename.
3342 Note the filename is used for informational purposes
3344 ret += fscanf (mapfile, "%[^\n]\n", filename);
3347 return (ret != 0 && ret != EOF);
3350 /* Fills the "to_find_memory_regions" target vector. Lists the memory
3351 regions in the inferior for a corefile. */
3354 linux_nat_find_memory_regions (int (*func) (CORE_ADDR,
3356 int, int, int, void *), void *obfd)
3358 long long pid = PIDGET (inferior_ptid);
3359 char mapsfilename[MAXPATHLEN];
3361 long long addr, endaddr, size, offset, inode;
3362 char permissions[8], device[8], filename[MAXPATHLEN];
3363 int read, write, exec;
3365 struct cleanup *cleanup;
3367 /* Compose the filename for the /proc memory map, and open it. */
3368 sprintf (mapsfilename, "/proc/%lld/maps", pid);
3369 if ((mapsfile = fopen (mapsfilename, "r")) == NULL)
3370 error (_("Could not open %s."), mapsfilename);
3371 cleanup = make_cleanup_fclose (mapsfile);
3374 fprintf_filtered (gdb_stdout,
3375 "Reading memory regions from %s\n", mapsfilename);
3377 /* Now iterate until end-of-file. */
3378 while (read_mapping (mapsfile, &addr, &endaddr, &permissions[0],
3379 &offset, &device[0], &inode, &filename[0]))
3381 size = endaddr - addr;
3383 /* Get the segment's permissions. */
3384 read = (strchr (permissions, 'r') != 0);
3385 write = (strchr (permissions, 'w') != 0);
3386 exec = (strchr (permissions, 'x') != 0);
3390 fprintf_filtered (gdb_stdout,
3391 "Save segment, %lld bytes at 0x%s (%c%c%c)",
3392 size, paddr_nz (addr),
3394 write ? 'w' : ' ', exec ? 'x' : ' ');
3396 fprintf_filtered (gdb_stdout, " for %s", filename);
3397 fprintf_filtered (gdb_stdout, "\n");
3400 /* Invoke the callback function to create the corefile
3402 func (addr, size, read, write, exec, obfd);
3404 do_cleanups (cleanup);
3409 find_signalled_thread (struct thread_info *info, void *data)
3411 if (info->stop_signal != TARGET_SIGNAL_0
3412 && ptid_get_pid (info->ptid) == ptid_get_pid (inferior_ptid))
3418 static enum target_signal
3419 find_stop_signal (void)
3421 struct thread_info *info =
3422 iterate_over_threads (find_signalled_thread, NULL);
3425 return info->stop_signal;
3427 return TARGET_SIGNAL_0;
3430 /* Records the thread's register state for the corefile note
3434 linux_nat_do_thread_registers (bfd *obfd, ptid_t ptid,
3435 char *note_data, int *note_size,
3436 enum target_signal stop_signal)
3438 gdb_gregset_t gregs;
3439 gdb_fpregset_t fpregs;
3440 unsigned long lwp = ptid_get_lwp (ptid);
3441 struct regcache *regcache = get_thread_regcache (ptid);
3442 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3443 const struct regset *regset;
3445 struct cleanup *old_chain;
3446 struct core_regset_section *sect_list;
3449 old_chain = save_inferior_ptid ();
3450 inferior_ptid = ptid;
3451 target_fetch_registers (regcache, -1);
3452 do_cleanups (old_chain);
3454 core_regset_p = gdbarch_regset_from_core_section_p (gdbarch);
3455 sect_list = gdbarch_core_regset_sections (gdbarch);
3458 && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg",
3459 sizeof (gregs))) != NULL
3460 && regset->collect_regset != NULL)
3461 regset->collect_regset (regset, regcache, -1,
3462 &gregs, sizeof (gregs));
3464 fill_gregset (regcache, &gregs, -1);
3466 note_data = (char *) elfcore_write_prstatus (obfd,
3470 stop_signal, &gregs);
3472 /* The loop below uses the new struct core_regset_section, which stores
3473 the supported section names and sizes for the core file. Note that
3474 note PRSTATUS needs to be treated specially. But the other notes are
3475 structurally the same, so they can benefit from the new struct. */
3476 if (core_regset_p && sect_list != NULL)
3477 while (sect_list->sect_name != NULL)
3479 /* .reg was already handled above. */
3480 if (strcmp (sect_list->sect_name, ".reg") == 0)
3485 regset = gdbarch_regset_from_core_section (gdbarch,
3486 sect_list->sect_name,
3488 gdb_assert (regset && regset->collect_regset);
3489 gdb_regset = xmalloc (sect_list->size);
3490 regset->collect_regset (regset, regcache, -1,
3491 gdb_regset, sect_list->size);
3492 note_data = (char *) elfcore_write_register_note (obfd,
3495 sect_list->sect_name,
3502 /* For architectures that does not have the struct core_regset_section
3503 implemented, we use the old method. When all the architectures have
3504 the new support, the code below should be deleted. */
3508 && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg2",
3509 sizeof (fpregs))) != NULL
3510 && regset->collect_regset != NULL)
3511 regset->collect_regset (regset, regcache, -1,
3512 &fpregs, sizeof (fpregs));
3514 fill_fpregset (regcache, &fpregs, -1);
3516 note_data = (char *) elfcore_write_prfpreg (obfd,
3519 &fpregs, sizeof (fpregs));
3525 struct linux_nat_corefile_thread_data
3531 enum target_signal stop_signal;
3534 /* Called by gdbthread.c once per thread. Records the thread's
3535 register state for the corefile note section. */
3538 linux_nat_corefile_thread_callback (struct lwp_info *ti, void *data)
3540 struct linux_nat_corefile_thread_data *args = data;
3542 args->note_data = linux_nat_do_thread_registers (args->obfd,
3552 /* Fills the "to_make_corefile_note" target vector. Builds the note
3553 section for a corefile, and returns it in a malloc buffer. */
3556 linux_nat_make_corefile_notes (bfd *obfd, int *note_size)
3558 struct linux_nat_corefile_thread_data thread_args;
3559 struct cleanup *old_chain;
3560 /* The variable size must be >= sizeof (prpsinfo_t.pr_fname). */
3561 char fname[16] = { '\0' };
3562 /* The variable size must be >= sizeof (prpsinfo_t.pr_psargs). */
3563 char psargs[80] = { '\0' };
3564 char *note_data = NULL;
3565 ptid_t current_ptid = inferior_ptid;
3569 if (get_exec_file (0))
3571 strncpy (fname, strrchr (get_exec_file (0), '/') + 1, sizeof (fname));
3572 strncpy (psargs, get_exec_file (0), sizeof (psargs));
3573 if (get_inferior_args ())
3576 char *psargs_end = psargs + sizeof (psargs);
3578 /* linux_elfcore_write_prpsinfo () handles zero unterminated
3580 string_end = memchr (psargs, 0, sizeof (psargs));
3581 if (string_end != NULL)
3583 *string_end++ = ' ';
3584 strncpy (string_end, get_inferior_args (),
3585 psargs_end - string_end);
3588 note_data = (char *) elfcore_write_prpsinfo (obfd,
3590 note_size, fname, psargs);
3593 /* Dump information for threads. */
3594 thread_args.obfd = obfd;
3595 thread_args.note_data = note_data;
3596 thread_args.note_size = note_size;
3597 thread_args.num_notes = 0;
3598 thread_args.stop_signal = find_stop_signal ();
3599 iterate_over_lwps (linux_nat_corefile_thread_callback, &thread_args);
3600 gdb_assert (thread_args.num_notes != 0);
3601 note_data = thread_args.note_data;
3603 auxv_len = target_read_alloc (¤t_target, TARGET_OBJECT_AUXV,
3607 note_data = elfcore_write_note (obfd, note_data, note_size,
3608 "CORE", NT_AUXV, auxv, auxv_len);
3612 make_cleanup (xfree, note_data);
3616 /* Implement the "info proc" command. */
3619 linux_nat_info_proc_cmd (char *args, int from_tty)
3621 long long pid = PIDGET (inferior_ptid);
3624 char buffer[MAXPATHLEN];
3625 char fname1[MAXPATHLEN], fname2[MAXPATHLEN];
3638 /* Break up 'args' into an argv array. */
3639 argv = gdb_buildargv (args);
3640 make_cleanup_freeargv (argv);
3642 while (argv != NULL && *argv != NULL)
3644 if (isdigit (argv[0][0]))
3646 pid = strtoul (argv[0], NULL, 10);
3648 else if (strncmp (argv[0], "mappings", strlen (argv[0])) == 0)
3652 else if (strcmp (argv[0], "status") == 0)
3656 else if (strcmp (argv[0], "stat") == 0)
3660 else if (strcmp (argv[0], "cmd") == 0)
3664 else if (strncmp (argv[0], "exe", strlen (argv[0])) == 0)
3668 else if (strcmp (argv[0], "cwd") == 0)
3672 else if (strncmp (argv[0], "all", strlen (argv[0])) == 0)
3678 /* [...] (future options here) */
3683 error (_("No current process: you must name one."));
3685 sprintf (fname1, "/proc/%lld", pid);
3686 if (stat (fname1, &dummy) != 0)
3687 error (_("No /proc directory: '%s'"), fname1);
3689 printf_filtered (_("process %lld\n"), pid);
3690 if (cmdline_f || all)
3692 sprintf (fname1, "/proc/%lld/cmdline", pid);
3693 if ((procfile = fopen (fname1, "r")) != NULL)
3695 struct cleanup *cleanup = make_cleanup_fclose (procfile);
3696 if (fgets (buffer, sizeof (buffer), procfile))
3697 printf_filtered ("cmdline = '%s'\n", buffer);
3699 warning (_("unable to read '%s'"), fname1);
3700 do_cleanups (cleanup);
3703 warning (_("unable to open /proc file '%s'"), fname1);
3707 sprintf (fname1, "/proc/%lld/cwd", pid);
3708 memset (fname2, 0, sizeof (fname2));
3709 if (readlink (fname1, fname2, sizeof (fname2)) > 0)
3710 printf_filtered ("cwd = '%s'\n", fname2);
3712 warning (_("unable to read link '%s'"), fname1);
3716 sprintf (fname1, "/proc/%lld/exe", pid);
3717 memset (fname2, 0, sizeof (fname2));
3718 if (readlink (fname1, fname2, sizeof (fname2)) > 0)
3719 printf_filtered ("exe = '%s'\n", fname2);
3721 warning (_("unable to read link '%s'"), fname1);
3723 if (mappings_f || all)
3725 sprintf (fname1, "/proc/%lld/maps", pid);
3726 if ((procfile = fopen (fname1, "r")) != NULL)
3728 long long addr, endaddr, size, offset, inode;
3729 char permissions[8], device[8], filename[MAXPATHLEN];
3730 struct cleanup *cleanup;
3732 cleanup = make_cleanup_fclose (procfile);
3733 printf_filtered (_("Mapped address spaces:\n\n"));
3734 if (gdbarch_addr_bit (current_gdbarch) == 32)
3736 printf_filtered ("\t%10s %10s %10s %10s %7s\n",
3739 " Size", " Offset", "objfile");
3743 printf_filtered (" %18s %18s %10s %10s %7s\n",
3746 " Size", " Offset", "objfile");
3749 while (read_mapping (procfile, &addr, &endaddr, &permissions[0],
3750 &offset, &device[0], &inode, &filename[0]))
3752 size = endaddr - addr;
3754 /* FIXME: carlton/2003-08-27: Maybe the printf_filtered
3755 calls here (and possibly above) should be abstracted
3756 out into their own functions? Andrew suggests using
3757 a generic local_address_string instead to print out
3758 the addresses; that makes sense to me, too. */
3760 if (gdbarch_addr_bit (current_gdbarch) == 32)
3762 printf_filtered ("\t%#10lx %#10lx %#10x %#10x %7s\n",
3763 (unsigned long) addr, /* FIXME: pr_addr */
3764 (unsigned long) endaddr,
3766 (unsigned int) offset,
3767 filename[0] ? filename : "");
3771 printf_filtered (" %#18lx %#18lx %#10x %#10x %7s\n",
3772 (unsigned long) addr, /* FIXME: pr_addr */
3773 (unsigned long) endaddr,
3775 (unsigned int) offset,
3776 filename[0] ? filename : "");
3780 do_cleanups (cleanup);
3783 warning (_("unable to open /proc file '%s'"), fname1);
3785 if (status_f || all)
3787 sprintf (fname1, "/proc/%lld/status", pid);
3788 if ((procfile = fopen (fname1, "r")) != NULL)
3790 struct cleanup *cleanup = make_cleanup_fclose (procfile);
3791 while (fgets (buffer, sizeof (buffer), procfile) != NULL)
3792 puts_filtered (buffer);
3793 do_cleanups (cleanup);
3796 warning (_("unable to open /proc file '%s'"), fname1);
3800 sprintf (fname1, "/proc/%lld/stat", pid);
3801 if ((procfile = fopen (fname1, "r")) != NULL)
3806 struct cleanup *cleanup = make_cleanup_fclose (procfile);
3808 if (fscanf (procfile, "%d ", &itmp) > 0)
3809 printf_filtered (_("Process: %d\n"), itmp);
3810 if (fscanf (procfile, "(%[^)]) ", &buffer[0]) > 0)
3811 printf_filtered (_("Exec file: %s\n"), buffer);
3812 if (fscanf (procfile, "%c ", &ctmp) > 0)
3813 printf_filtered (_("State: %c\n"), ctmp);
3814 if (fscanf (procfile, "%d ", &itmp) > 0)
3815 printf_filtered (_("Parent process: %d\n"), itmp);
3816 if (fscanf (procfile, "%d ", &itmp) > 0)
3817 printf_filtered (_("Process group: %d\n"), itmp);
3818 if (fscanf (procfile, "%d ", &itmp) > 0)
3819 printf_filtered (_("Session id: %d\n"), itmp);
3820 if (fscanf (procfile, "%d ", &itmp) > 0)
3821 printf_filtered (_("TTY: %d\n"), itmp);
3822 if (fscanf (procfile, "%d ", &itmp) > 0)
3823 printf_filtered (_("TTY owner process group: %d\n"), itmp);
3824 if (fscanf (procfile, "%lu ", <mp) > 0)
3825 printf_filtered (_("Flags: 0x%lx\n"), ltmp);
3826 if (fscanf (procfile, "%lu ", <mp) > 0)
3827 printf_filtered (_("Minor faults (no memory page): %lu\n"),
3828 (unsigned long) ltmp);
3829 if (fscanf (procfile, "%lu ", <mp) > 0)
3830 printf_filtered (_("Minor faults, children: %lu\n"),
3831 (unsigned long) ltmp);
3832 if (fscanf (procfile, "%lu ", <mp) > 0)
3833 printf_filtered (_("Major faults (memory page faults): %lu\n"),
3834 (unsigned long) ltmp);
3835 if (fscanf (procfile, "%lu ", <mp) > 0)
3836 printf_filtered (_("Major faults, children: %lu\n"),
3837 (unsigned long) ltmp);
3838 if (fscanf (procfile, "%ld ", <mp) > 0)
3839 printf_filtered (_("utime: %ld\n"), ltmp);
3840 if (fscanf (procfile, "%ld ", <mp) > 0)
3841 printf_filtered (_("stime: %ld\n"), ltmp);
3842 if (fscanf (procfile, "%ld ", <mp) > 0)
3843 printf_filtered (_("utime, children: %ld\n"), ltmp);
3844 if (fscanf (procfile, "%ld ", <mp) > 0)
3845 printf_filtered (_("stime, children: %ld\n"), ltmp);
3846 if (fscanf (procfile, "%ld ", <mp) > 0)
3847 printf_filtered (_("jiffies remaining in current time slice: %ld\n"),
3849 if (fscanf (procfile, "%ld ", <mp) > 0)
3850 printf_filtered (_("'nice' value: %ld\n"), ltmp);
3851 if (fscanf (procfile, "%lu ", <mp) > 0)
3852 printf_filtered (_("jiffies until next timeout: %lu\n"),
3853 (unsigned long) ltmp);
3854 if (fscanf (procfile, "%lu ", <mp) > 0)
3855 printf_filtered (_("jiffies until next SIGALRM: %lu\n"),
3856 (unsigned long) ltmp);
3857 if (fscanf (procfile, "%ld ", <mp) > 0)
3858 printf_filtered (_("start time (jiffies since system boot): %ld\n"),
3860 if (fscanf (procfile, "%lu ", <mp) > 0)
3861 printf_filtered (_("Virtual memory size: %lu\n"),
3862 (unsigned long) ltmp);
3863 if (fscanf (procfile, "%lu ", <mp) > 0)
3864 printf_filtered (_("Resident set size: %lu\n"), (unsigned long) ltmp);
3865 if (fscanf (procfile, "%lu ", <mp) > 0)
3866 printf_filtered (_("rlim: %lu\n"), (unsigned long) ltmp);
3867 if (fscanf (procfile, "%lu ", <mp) > 0)
3868 printf_filtered (_("Start of text: 0x%lx\n"), ltmp);
3869 if (fscanf (procfile, "%lu ", <mp) > 0)
3870 printf_filtered (_("End of text: 0x%lx\n"), ltmp);
3871 if (fscanf (procfile, "%lu ", <mp) > 0)
3872 printf_filtered (_("Start of stack: 0x%lx\n"), ltmp);
3873 #if 0 /* Don't know how architecture-dependent the rest is...
3874 Anyway the signal bitmap info is available from "status". */
3875 if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */
3876 printf_filtered (_("Kernel stack pointer: 0x%lx\n"), ltmp);
3877 if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */
3878 printf_filtered (_("Kernel instr pointer: 0x%lx\n"), ltmp);
3879 if (fscanf (procfile, "%ld ", <mp) > 0)
3880 printf_filtered (_("Pending signals bitmap: 0x%lx\n"), ltmp);
3881 if (fscanf (procfile, "%ld ", <mp) > 0)
3882 printf_filtered (_("Blocked signals bitmap: 0x%lx\n"), ltmp);
3883 if (fscanf (procfile, "%ld ", <mp) > 0)
3884 printf_filtered (_("Ignored signals bitmap: 0x%lx\n"), ltmp);
3885 if (fscanf (procfile, "%ld ", <mp) > 0)
3886 printf_filtered (_("Catched signals bitmap: 0x%lx\n"), ltmp);
3887 if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */
3888 printf_filtered (_("wchan (system call): 0x%lx\n"), ltmp);
3890 do_cleanups (cleanup);
3893 warning (_("unable to open /proc file '%s'"), fname1);
3897 /* Implement the to_xfer_partial interface for memory reads using the /proc
3898 filesystem. Because we can use a single read() call for /proc, this
3899 can be much more efficient than banging away at PTRACE_PEEKTEXT,
3900 but it doesn't support writes. */
3903 linux_proc_xfer_partial (struct target_ops *ops, enum target_object object,
3904 const char *annex, gdb_byte *readbuf,
3905 const gdb_byte *writebuf,
3906 ULONGEST offset, LONGEST len)
3912 if (object != TARGET_OBJECT_MEMORY || !readbuf)
3915 /* Don't bother for one word. */
3916 if (len < 3 * sizeof (long))
3919 /* We could keep this file open and cache it - possibly one per
3920 thread. That requires some juggling, but is even faster. */
3921 sprintf (filename, "/proc/%d/mem", PIDGET (inferior_ptid));
3922 fd = open (filename, O_RDONLY | O_LARGEFILE);
3926 /* If pread64 is available, use it. It's faster if the kernel
3927 supports it (only one syscall), and it's 64-bit safe even on
3928 32-bit platforms (for instance, SPARC debugging a SPARC64
3931 if (pread64 (fd, readbuf, len, offset) != len)
3933 if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len)
3943 /* Parse LINE as a signal set and add its set bits to SIGS. */
3946 add_line_to_sigset (const char *line, sigset_t *sigs)
3948 int len = strlen (line) - 1;
3952 if (line[len] != '\n')
3953 error (_("Could not parse signal set: %s"), line);
3961 if (*p >= '0' && *p <= '9')
3963 else if (*p >= 'a' && *p <= 'f')
3964 digit = *p - 'a' + 10;
3966 error (_("Could not parse signal set: %s"), line);
3971 sigaddset (sigs, signum + 1);
3973 sigaddset (sigs, signum + 2);
3975 sigaddset (sigs, signum + 3);
3977 sigaddset (sigs, signum + 4);
3983 /* Find process PID's pending signals from /proc/pid/status and set
3987 linux_proc_pending_signals (int pid, sigset_t *pending, sigset_t *blocked, sigset_t *ignored)
3990 char buffer[MAXPATHLEN], fname[MAXPATHLEN];
3992 struct cleanup *cleanup;
3994 sigemptyset (pending);
3995 sigemptyset (blocked);
3996 sigemptyset (ignored);
3997 sprintf (fname, "/proc/%d/status", pid);
3998 procfile = fopen (fname, "r");
3999 if (procfile == NULL)
4000 error (_("Could not open %s"), fname);
4001 cleanup = make_cleanup_fclose (procfile);
4003 while (fgets (buffer, MAXPATHLEN, procfile) != NULL)
4005 /* Normal queued signals are on the SigPnd line in the status
4006 file. However, 2.6 kernels also have a "shared" pending
4007 queue for delivering signals to a thread group, so check for
4010 Unfortunately some Red Hat kernels include the shared pending
4011 queue but not the ShdPnd status field. */
4013 if (strncmp (buffer, "SigPnd:\t", 8) == 0)
4014 add_line_to_sigset (buffer + 8, pending);
4015 else if (strncmp (buffer, "ShdPnd:\t", 8) == 0)
4016 add_line_to_sigset (buffer + 8, pending);
4017 else if (strncmp (buffer, "SigBlk:\t", 8) == 0)
4018 add_line_to_sigset (buffer + 8, blocked);
4019 else if (strncmp (buffer, "SigIgn:\t", 8) == 0)
4020 add_line_to_sigset (buffer + 8, ignored);
4023 do_cleanups (cleanup);
4027 linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object,
4028 const char *annex, gdb_byte *readbuf,
4029 const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
4031 /* We make the process list snapshot when the object starts to be
4033 static const char *buf;
4034 static LONGEST len_avail = -1;
4035 static struct obstack obstack;
4039 gdb_assert (object == TARGET_OBJECT_OSDATA);
4041 if (strcmp (annex, "processes") != 0)
4044 gdb_assert (readbuf && !writebuf);
4048 if (len_avail != -1 && len_avail != 0)
4049 obstack_free (&obstack, NULL);
4052 obstack_init (&obstack);
4053 obstack_grow_str (&obstack, "<osdata type=\"processes\">\n");
4055 dirp = opendir ("/proc");
4059 while ((dp = readdir (dirp)) != NULL)
4061 struct stat statbuf;
4062 char procentry[sizeof ("/proc/4294967295")];
4064 if (!isdigit (dp->d_name[0])
4065 || strlen (dp->d_name) > sizeof ("4294967295") - 1)
4068 sprintf (procentry, "/proc/%s", dp->d_name);
4069 if (stat (procentry, &statbuf) == 0
4070 && S_ISDIR (statbuf.st_mode))
4074 char cmd[MAXPATHLEN + 1];
4075 struct passwd *entry;
4077 pathname = xstrprintf ("/proc/%s/cmdline", dp->d_name);
4078 entry = getpwuid (statbuf.st_uid);
4080 if ((f = fopen (pathname, "r")) != NULL)
4082 size_t len = fread (cmd, 1, sizeof (cmd) - 1, f);
4086 for (i = 0; i < len; i++)
4091 obstack_xml_printf (
4094 "<column name=\"pid\">%s</column>"
4095 "<column name=\"user\">%s</column>"
4096 "<column name=\"command\">%s</column>"
4099 entry ? entry->pw_name : "?",
4112 obstack_grow_str0 (&obstack, "</osdata>\n");
4113 buf = obstack_finish (&obstack);
4114 len_avail = strlen (buf);
4117 if (offset >= len_avail)
4119 /* Done. Get rid of the obstack. */
4120 obstack_free (&obstack, NULL);
4126 if (len > len_avail - offset)
4127 len = len_avail - offset;
4128 memcpy (readbuf, buf + offset, len);
4134 linux_xfer_partial (struct target_ops *ops, enum target_object object,
4135 const char *annex, gdb_byte *readbuf,
4136 const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
4140 if (object == TARGET_OBJECT_AUXV)
4141 return procfs_xfer_auxv (ops, object, annex, readbuf, writebuf,
4144 if (object == TARGET_OBJECT_OSDATA)
4145 return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf,
4148 xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf,
4153 return super_xfer_partial (ops, object, annex, readbuf, writebuf,
4157 /* Create a prototype generic GNU/Linux target. The client can override
4158 it with local methods. */
4161 linux_target_install_ops (struct target_ops *t)
4163 t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint;
4164 t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint;
4165 t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint;
4166 t->to_pid_to_exec_file = linux_child_pid_to_exec_file;
4167 t->to_post_startup_inferior = linux_child_post_startup_inferior;
4168 t->to_post_attach = linux_child_post_attach;
4169 t->to_follow_fork = linux_child_follow_fork;
4170 t->to_find_memory_regions = linux_nat_find_memory_regions;
4171 t->to_make_corefile_notes = linux_nat_make_corefile_notes;
4173 super_xfer_partial = t->to_xfer_partial;
4174 t->to_xfer_partial = linux_xfer_partial;
4180 struct target_ops *t;
4182 t = inf_ptrace_target ();
4183 linux_target_install_ops (t);
4189 linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int))
4191 struct target_ops *t;
4193 t = inf_ptrace_trad_target (register_u_offset);
4194 linux_target_install_ops (t);
4199 /* target_is_async_p implementation. */
4202 linux_nat_is_async_p (void)
4204 /* NOTE: palves 2008-03-21: We're only async when the user requests
4205 it explicitly with the "maintenance set target-async" command.
4206 Someday, linux will always be async. */
4207 if (!target_async_permitted)
4213 /* target_can_async_p implementation. */
4216 linux_nat_can_async_p (void)
4218 /* NOTE: palves 2008-03-21: We're only async when the user requests
4219 it explicitly with the "maintenance set target-async" command.
4220 Someday, linux will always be async. */
4221 if (!target_async_permitted)
4224 /* See target.h/target_async_mask. */
4225 return linux_nat_async_mask_value;
4229 linux_nat_supports_non_stop (void)
4234 /* target_async_mask implementation. */
4237 linux_nat_async_mask (int mask)
4240 current_state = linux_nat_async_mask_value;
4242 if (current_state != mask)
4246 linux_nat_async (NULL, 0);
4247 linux_nat_async_mask_value = mask;
4251 linux_nat_async_mask_value = mask;
4252 linux_nat_async (inferior_event_handler, 0);
4256 return current_state;
4259 /* Pop an event from the event pipe. */
4262 linux_nat_event_pipe_pop (int* ptr_status, int* ptr_options)
4264 struct waitpid_result event = {0};
4269 ret = read (linux_nat_event_pipe[0], &event, sizeof (event));
4271 while (ret == -1 && errno == EINTR);
4273 gdb_assert (ret == sizeof (event));
4275 *ptr_status = event.status;
4276 *ptr_options = event.options;
4278 linux_nat_num_queued_events--;
4283 /* Push an event into the event pipe. */
4286 linux_nat_event_pipe_push (int pid, int status, int options)
4289 struct waitpid_result event = {0};
4291 event.status = status;
4292 event.options = options;
4296 ret = write (linux_nat_event_pipe[1], &event, sizeof (event));
4297 gdb_assert ((ret == -1 && errno == EINTR) || ret == sizeof (event));
4298 } while (ret == -1 && errno == EINTR);
4300 linux_nat_num_queued_events++;
4304 get_pending_events (void)
4306 int status, options, pid;
4308 if (!target_async_permitted
4309 || linux_nat_async_events_state != sigchld_async)
4310 internal_error (__FILE__, __LINE__,
4311 "get_pending_events called with async masked");
4316 options = __WCLONE | WNOHANG;
4320 pid = waitpid (-1, &status, options);
4322 while (pid == -1 && errno == EINTR);
4329 pid = waitpid (-1, &status, options);
4331 while (pid == -1 && errno == EINTR);
4335 /* No more children reporting events. */
4338 if (debug_linux_nat_async)
4339 fprintf_unfiltered (gdb_stdlog, "\
4340 get_pending_events: pid(%d), status(%x), options (%x)\n",
4341 pid, status, options);
4343 linux_nat_event_pipe_push (pid, status, options);
4346 if (debug_linux_nat_async)
4347 fprintf_unfiltered (gdb_stdlog, "\
4348 get_pending_events: linux_nat_num_queued_events(%d)\n",
4349 linux_nat_num_queued_events);
4352 /* SIGCHLD handler for async mode. */
4355 async_sigchld_handler (int signo)
4357 if (debug_linux_nat_async)
4358 fprintf_unfiltered (gdb_stdlog, "async_sigchld_handler\n");
4360 get_pending_events ();
4363 /* Set SIGCHLD handling state to STATE. Returns previous state. */
4365 static enum sigchld_state
4366 linux_nat_async_events (enum sigchld_state state)
4368 enum sigchld_state current_state = linux_nat_async_events_state;
4370 if (debug_linux_nat_async)
4371 fprintf_unfiltered (gdb_stdlog,
4372 "LNAE: state(%d): linux_nat_async_events_state(%d), "
4373 "linux_nat_num_queued_events(%d)\n",
4374 state, linux_nat_async_events_state,
4375 linux_nat_num_queued_events);
4377 if (current_state != state)
4380 sigemptyset (&mask);
4381 sigaddset (&mask, SIGCHLD);
4383 /* Always block before changing state. */
4384 sigprocmask (SIG_BLOCK, &mask, NULL);
4386 /* Set new state. */
4387 linux_nat_async_events_state = state;
4393 /* Block target events. */
4394 sigprocmask (SIG_BLOCK, &mask, NULL);
4395 sigaction (SIGCHLD, &sync_sigchld_action, NULL);
4396 /* Get events out of queue, and make them available to
4397 queued_waitpid / my_waitpid. */
4398 pipe_to_local_event_queue ();
4403 /* Unblock target events for async mode. */
4405 sigprocmask (SIG_BLOCK, &mask, NULL);
4407 /* Put events we already waited on, in the pipe first, so
4409 local_event_queue_to_pipe ();
4410 /* While in masked async, we may have not collected all
4411 the pending events. Get them out now. */
4412 get_pending_events ();
4415 sigaction (SIGCHLD, &async_sigchld_action, NULL);
4416 sigprocmask (SIG_UNBLOCK, &mask, NULL);
4419 case sigchld_default:
4421 /* SIGCHLD default mode. */
4422 sigaction (SIGCHLD, &sigchld_default_action, NULL);
4424 /* Get events out of queue, and make them available to
4425 queued_waitpid / my_waitpid. */
4426 pipe_to_local_event_queue ();
4428 /* Unblock SIGCHLD. */
4429 sigprocmask (SIG_UNBLOCK, &mask, NULL);
4435 return current_state;
4438 static int async_terminal_is_ours = 1;
4440 /* target_terminal_inferior implementation. */
4443 linux_nat_terminal_inferior (void)
4445 if (!target_is_async_p ())
4447 /* Async mode is disabled. */
4448 terminal_inferior ();
4452 /* GDB should never give the terminal to the inferior, if the
4453 inferior is running in the background (run&, continue&, etc.).
4454 This check can be removed when the common code is fixed. */
4455 if (!sync_execution)
4458 terminal_inferior ();
4460 if (!async_terminal_is_ours)
4463 delete_file_handler (input_fd);
4464 async_terminal_is_ours = 0;
4468 /* target_terminal_ours implementation. */
4471 linux_nat_terminal_ours (void)
4473 if (!target_is_async_p ())
4475 /* Async mode is disabled. */
4480 /* GDB should never give the terminal to the inferior if the
4481 inferior is running in the background (run&, continue&, etc.),
4482 but claiming it sure should. */
4485 if (!sync_execution)
4488 if (async_terminal_is_ours)
4491 clear_sigint_trap ();
4492 add_file_handler (input_fd, stdin_event_handler, 0);
4493 async_terminal_is_ours = 1;
4496 static void (*async_client_callback) (enum inferior_event_type event_type,
4498 static void *async_client_context;
4501 linux_nat_async_file_handler (int error, gdb_client_data client_data)
4503 async_client_callback (INF_REG_EVENT, async_client_context);
4506 /* target_async implementation. */
4509 linux_nat_async (void (*callback) (enum inferior_event_type event_type,
4510 void *context), void *context)
4512 if (linux_nat_async_mask_value == 0 || !target_async_permitted)
4513 internal_error (__FILE__, __LINE__,
4514 "Calling target_async when async is masked");
4516 if (callback != NULL)
4518 async_client_callback = callback;
4519 async_client_context = context;
4520 add_file_handler (linux_nat_event_pipe[0],
4521 linux_nat_async_file_handler, NULL);
4523 linux_nat_async_events (sigchld_async);
4527 async_client_callback = callback;
4528 async_client_context = context;
4530 linux_nat_async_events (sigchld_sync);
4531 delete_file_handler (linux_nat_event_pipe[0]);
4536 /* Stop an LWP, and push a TARGET_SIGNAL_0 stop status if no other
4540 linux_nat_stop_lwp (struct lwp_info *lwp, void *data)
4542 ptid_t ptid = * (ptid_t *) data;
4544 if (ptid_equal (lwp->ptid, ptid)
4545 || ptid_equal (minus_one_ptid, ptid)
4546 || (ptid_is_pid (ptid)
4547 && ptid_get_pid (ptid) == ptid_get_pid (lwp->ptid)))
4553 if (debug_linux_nat)
4554 fprintf_unfiltered (gdb_stdlog,
4555 "LNSL: running -> suspending %s\n",
4556 target_pid_to_str (lwp->ptid));
4558 /* Peek once, to check if we've already waited for this
4560 pid = queued_waitpid_1 (ptid_get_lwp (lwp->ptid), &status,
4561 lwp->cloned ? __WCLONE : 0, 1 /* peek */);
4565 ptid_t ptid = lwp->ptid;
4567 stop_callback (lwp, NULL);
4568 stop_wait_callback (lwp, NULL);
4570 /* If the lwp exits while we try to stop it, there's
4571 nothing else to do. */
4572 lwp = find_lwp_pid (ptid);
4576 pid = queued_waitpid_1 (ptid_get_lwp (lwp->ptid), &status,
4577 lwp->cloned ? __WCLONE : 0,
4581 /* If we didn't collect any signal other than SIGSTOP while
4582 stopping the LWP, push a SIGNAL_0 event. In either case,
4583 the event-loop will end up calling target_wait which will
4586 push_waitpid (ptid_get_lwp (lwp->ptid), W_STOPCODE (0),
4587 lwp->cloned ? __WCLONE : 0);
4591 /* Already known to be stopped; do nothing. */
4593 if (debug_linux_nat)
4595 if (find_thread_pid (lwp->ptid)->stop_requested)
4596 fprintf_unfiltered (gdb_stdlog, "\
4597 LNSL: already stopped/stop_requested %s\n",
4598 target_pid_to_str (lwp->ptid));
4600 fprintf_unfiltered (gdb_stdlog, "\
4601 LNSL: already stopped/no stop_requested yet %s\n",
4602 target_pid_to_str (lwp->ptid));
4610 linux_nat_stop (ptid_t ptid)
4614 linux_nat_async_events (sigchld_sync);
4615 iterate_over_lwps (linux_nat_stop_lwp, &ptid);
4616 target_async (inferior_event_handler, 0);
4619 linux_ops->to_stop (ptid);
4623 linux_nat_add_target (struct target_ops *t)
4625 /* Save the provided single-threaded target. We save this in a separate
4626 variable because another target we've inherited from (e.g. inf-ptrace)
4627 may have saved a pointer to T; we want to use it for the final
4628 process stratum target. */
4629 linux_ops_saved = *t;
4630 linux_ops = &linux_ops_saved;
4632 /* Override some methods for multithreading. */
4633 t->to_create_inferior = linux_nat_create_inferior;
4634 t->to_attach = linux_nat_attach;
4635 t->to_detach = linux_nat_detach;
4636 t->to_resume = linux_nat_resume;
4637 t->to_wait = linux_nat_wait;
4638 t->to_xfer_partial = linux_nat_xfer_partial;
4639 t->to_kill = linux_nat_kill;
4640 t->to_mourn_inferior = linux_nat_mourn_inferior;
4641 t->to_thread_alive = linux_nat_thread_alive;
4642 t->to_pid_to_str = linux_nat_pid_to_str;
4643 t->to_has_thread_control = tc_schedlock;
4645 t->to_can_async_p = linux_nat_can_async_p;
4646 t->to_is_async_p = linux_nat_is_async_p;
4647 t->to_supports_non_stop = linux_nat_supports_non_stop;
4648 t->to_async = linux_nat_async;
4649 t->to_async_mask = linux_nat_async_mask;
4650 t->to_terminal_inferior = linux_nat_terminal_inferior;
4651 t->to_terminal_ours = linux_nat_terminal_ours;
4653 /* Methods for non-stop support. */
4654 t->to_stop = linux_nat_stop;
4656 /* We don't change the stratum; this target will sit at
4657 process_stratum and thread_db will set at thread_stratum. This
4658 is a little strange, since this is a multi-threaded-capable
4659 target, but we want to be on the stack below thread_db, and we
4660 also want to be used for single-threaded processes. */
4665 /* Register a method to call whenever a new thread is attached. */
4667 linux_nat_set_new_thread (struct target_ops *t, void (*new_thread) (ptid_t))
4669 /* Save the pointer. We only support a single registered instance
4670 of the GNU/Linux native target, so we do not need to map this to
4672 linux_nat_new_thread = new_thread;
4675 /* Return the saved siginfo associated with PTID. */
4677 linux_nat_get_siginfo (ptid_t ptid)
4679 struct lwp_info *lp = find_lwp_pid (ptid);
4681 gdb_assert (lp != NULL);
4683 return &lp->siginfo;
4686 /* Enable/Disable async mode. */
4689 linux_nat_setup_async (void)
4691 if (pipe (linux_nat_event_pipe) == -1)
4692 internal_error (__FILE__, __LINE__,
4693 "creating event pipe failed.");
4694 fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK);
4695 fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK);
4699 _initialize_linux_nat (void)
4703 add_info ("proc", linux_nat_info_proc_cmd, _("\
4704 Show /proc process information about any running process.\n\
4705 Specify any process id, or use the program being debugged by default.\n\
4706 Specify any of the following keywords for detailed info:\n\
4707 mappings -- list of mapped memory regions.\n\
4708 stat -- list a bunch of random process info.\n\
4709 status -- list a different bunch of random process info.\n\
4710 all -- list all available /proc info."));
4712 add_setshow_zinteger_cmd ("lin-lwp", class_maintenance,
4713 &debug_linux_nat, _("\
4714 Set debugging of GNU/Linux lwp module."), _("\
4715 Show debugging of GNU/Linux lwp module."), _("\
4716 Enables printf debugging output."),
4718 show_debug_linux_nat,
4719 &setdebuglist, &showdebuglist);
4721 add_setshow_zinteger_cmd ("lin-lwp-async", class_maintenance,
4722 &debug_linux_nat_async, _("\
4723 Set debugging of GNU/Linux async lwp module."), _("\
4724 Show debugging of GNU/Linux async lwp module."), _("\
4725 Enables printf debugging output."),
4727 show_debug_linux_nat_async,
4728 &setdebuglist, &showdebuglist);
4730 /* Get the default SIGCHLD action. Used while forking an inferior
4731 (see linux_nat_create_inferior/linux_nat_async_events). */
4732 sigaction (SIGCHLD, NULL, &sigchld_default_action);
4734 /* Block SIGCHLD by default. Doing this early prevents it getting
4735 unblocked if an exception is thrown due to an error while the
4736 inferior is starting (sigsetjmp/siglongjmp). */
4737 sigemptyset (&mask);
4738 sigaddset (&mask, SIGCHLD);
4739 sigprocmask (SIG_BLOCK, &mask, NULL);
4741 /* Save this mask as the default. */
4742 sigprocmask (SIG_SETMASK, NULL, &normal_mask);
4744 /* The synchronous SIGCHLD handler. */
4745 sync_sigchld_action.sa_handler = sigchld_handler;
4746 sigemptyset (&sync_sigchld_action.sa_mask);
4747 sync_sigchld_action.sa_flags = SA_RESTART;
4749 /* Make it the default. */
4750 sigaction (SIGCHLD, &sync_sigchld_action, NULL);
4752 /* Make sure we don't block SIGCHLD during a sigsuspend. */
4753 sigprocmask (SIG_SETMASK, NULL, &suspend_mask);
4754 sigdelset (&suspend_mask, SIGCHLD);
4756 /* SIGCHLD handler for async mode. */
4757 async_sigchld_action.sa_handler = async_sigchld_handler;
4758 sigemptyset (&async_sigchld_action.sa_mask);
4759 async_sigchld_action.sa_flags = SA_RESTART;
4761 linux_nat_setup_async ();
4763 add_setshow_boolean_cmd ("disable-randomization", class_support,
4764 &disable_randomization, _("\
4765 Set disabling of debuggee's virtual address space randomization."), _("\
4766 Show disabling of debuggee's virtual address space randomization."), _("\
4767 When this mode is on (which is the default), randomization of the virtual\n\
4768 address space is disabled. Standalone programs run with the randomization\n\
4769 enabled by default on some platforms."),
4770 &set_disable_randomization,
4771 &show_disable_randomization,
4772 &setlist, &showlist);
4776 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
4777 the GNU/Linux Threads library and therefore doesn't really belong
4780 /* Read variable NAME in the target and return its value if found.
4781 Otherwise return zero. It is assumed that the type of the variable
4785 get_signo (const char *name)
4787 struct minimal_symbol *ms;
4790 ms = lookup_minimal_symbol (name, NULL, NULL);
4794 if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo,
4795 sizeof (signo)) != 0)
4801 /* Return the set of signals used by the threads library in *SET. */
4804 lin_thread_get_thread_signals (sigset_t *set)
4806 struct sigaction action;
4807 int restart, cancel;
4808 sigset_t blocked_mask;
4810 sigemptyset (&blocked_mask);
4813 restart = get_signo ("__pthread_sig_restart");
4814 cancel = get_signo ("__pthread_sig_cancel");
4816 /* LinuxThreads normally uses the first two RT signals, but in some legacy
4817 cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
4818 not provide any way for the debugger to query the signal numbers -
4819 fortunately they don't change! */
4822 restart = __SIGRTMIN;
4825 cancel = __SIGRTMIN + 1;
4827 sigaddset (set, restart);
4828 sigaddset (set, cancel);
4830 /* The GNU/Linux Threads library makes terminating threads send a
4831 special "cancel" signal instead of SIGCHLD. Make sure we catch
4832 those (to prevent them from terminating GDB itself, which is
4833 likely to be their default action) and treat them the same way as
4836 action.sa_handler = sigchld_handler;
4837 sigemptyset (&action.sa_mask);
4838 action.sa_flags = SA_RESTART;
4839 sigaction (cancel, &action, NULL);
4841 /* We block the "cancel" signal throughout this code ... */
4842 sigaddset (&blocked_mask, cancel);
4843 sigprocmask (SIG_BLOCK, &blocked_mask, NULL);
4845 /* ... except during a sigsuspend. */
4846 sigdelset (&suspend_mask, cancel);