1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006
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 2 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, write to the Free Software
20 Foundation, Inc., 51 Franklin Street, Fifth Floor,
21 Boston, MA 02110-1301, USA. */
26 #include "gdb_string.h"
28 #include "gdb_assert.h"
29 #ifdef HAVE_TKILL_SYSCALL
31 #include <sys/syscall.h>
33 #include <sys/ptrace.h>
34 #include "linux-nat.h"
35 #include "linux-fork.h"
36 #include "gdbthread.h"
40 #include "inf-ptrace.h"
42 #include <sys/param.h> /* for MAXPATHLEN */
43 #include <sys/procfs.h> /* for elf_gregset etc. */
44 #include "elf-bfd.h" /* for elfcore_write_* */
45 #include "gregset.h" /* for gregset */
46 #include "gdbcore.h" /* for get_exec_file */
47 #include <ctype.h> /* for isdigit */
48 #include "gdbthread.h" /* for struct thread_info etc. */
49 #include "gdb_stat.h" /* for struct stat */
50 #include <fcntl.h> /* for O_RDONLY */
56 /* If the system headers did not provide the constants, hard-code the normal
58 #ifndef PTRACE_EVENT_FORK
60 #define PTRACE_SETOPTIONS 0x4200
61 #define PTRACE_GETEVENTMSG 0x4201
63 /* options set using PTRACE_SETOPTIONS */
64 #define PTRACE_O_TRACESYSGOOD 0x00000001
65 #define PTRACE_O_TRACEFORK 0x00000002
66 #define PTRACE_O_TRACEVFORK 0x00000004
67 #define PTRACE_O_TRACECLONE 0x00000008
68 #define PTRACE_O_TRACEEXEC 0x00000010
69 #define PTRACE_O_TRACEVFORKDONE 0x00000020
70 #define PTRACE_O_TRACEEXIT 0x00000040
72 /* Wait extended result codes for the above trace options. */
73 #define PTRACE_EVENT_FORK 1
74 #define PTRACE_EVENT_VFORK 2
75 #define PTRACE_EVENT_CLONE 3
76 #define PTRACE_EVENT_EXEC 4
77 #define PTRACE_EVENT_VFORK_DONE 5
78 #define PTRACE_EVENT_EXIT 6
80 #endif /* PTRACE_EVENT_FORK */
82 /* We can't always assume that this flag is available, but all systems
83 with the ptrace event handlers also have __WALL, so it's safe to use
86 #define __WALL 0x40000000 /* Wait for any child. */
89 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
90 the use of the multi-threaded target. */
91 static struct target_ops *linux_ops;
92 static struct target_ops linux_ops_saved;
94 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
95 Called by our to_xfer_partial. */
96 static LONGEST (*super_xfer_partial) (struct target_ops *,
98 const char *, gdb_byte *,
102 static int debug_linux_nat;
104 show_debug_linux_nat (struct ui_file *file, int from_tty,
105 struct cmd_list_element *c, const char *value)
107 fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"),
111 static int linux_parent_pid;
113 struct simple_pid_list
116 struct simple_pid_list *next;
118 struct simple_pid_list *stopped_pids;
120 /* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACEFORK
121 can not be used, 1 if it can. */
123 static int linux_supports_tracefork_flag = -1;
125 /* If we have PTRACE_O_TRACEFORK, this flag indicates whether we also have
126 PTRACE_O_TRACEVFORKDONE. */
128 static int linux_supports_tracevforkdone_flag = -1;
131 /* Trivial list manipulation functions to keep track of a list of
132 new stopped processes. */
134 add_to_pid_list (struct simple_pid_list **listp, int pid)
136 struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list));
138 new_pid->next = *listp;
143 pull_pid_from_list (struct simple_pid_list **listp, int pid)
145 struct simple_pid_list **p;
147 for (p = listp; *p != NULL; p = &(*p)->next)
148 if ((*p)->pid == pid)
150 struct simple_pid_list *next = (*p)->next;
159 linux_record_stopped_pid (int pid)
161 add_to_pid_list (&stopped_pids, pid);
165 /* A helper function for linux_test_for_tracefork, called after fork (). */
168 linux_tracefork_child (void)
172 ptrace (PTRACE_TRACEME, 0, 0, 0);
173 kill (getpid (), SIGSTOP);
178 /* Wrapper function for waitpid which handles EINTR. */
181 my_waitpid (int pid, int *status, int flags)
186 ret = waitpid (pid, status, flags);
188 while (ret == -1 && errno == EINTR);
193 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events.
195 First, we try to enable fork tracing on ORIGINAL_PID. If this fails,
196 we know that the feature is not available. This may change the tracing
197 options for ORIGINAL_PID, but we'll be setting them shortly anyway.
199 However, if it succeeds, we don't know for sure that the feature is
200 available; old versions of PTRACE_SETOPTIONS ignored unknown options. We
201 create a child process, attach to it, use PTRACE_SETOPTIONS to enable
202 fork tracing, and let it fork. If the process exits, we assume that we
203 can't use TRACEFORK; if we get the fork notification, and we can extract
204 the new child's PID, then we assume that we can. */
207 linux_test_for_tracefork (int original_pid)
209 int child_pid, ret, status;
212 linux_supports_tracefork_flag = 0;
213 linux_supports_tracevforkdone_flag = 0;
215 ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACEFORK);
221 perror_with_name (("fork"));
224 linux_tracefork_child ();
226 ret = my_waitpid (child_pid, &status, 0);
228 perror_with_name (("waitpid"));
229 else if (ret != child_pid)
230 error (_("linux_test_for_tracefork: waitpid: unexpected result %d."), ret);
231 if (! WIFSTOPPED (status))
232 error (_("linux_test_for_tracefork: waitpid: unexpected status %d."), status);
234 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK);
237 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
240 warning (_("linux_test_for_tracefork: failed to kill child"));
244 ret = my_waitpid (child_pid, &status, 0);
245 if (ret != child_pid)
246 warning (_("linux_test_for_tracefork: failed to wait for killed child"));
247 else if (!WIFSIGNALED (status))
248 warning (_("linux_test_for_tracefork: unexpected wait status 0x%x from "
249 "killed child"), status);
254 /* Check whether PTRACE_O_TRACEVFORKDONE is available. */
255 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0,
256 PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORKDONE);
257 linux_supports_tracevforkdone_flag = (ret == 0);
259 ret = ptrace (PTRACE_CONT, child_pid, 0, 0);
261 warning (_("linux_test_for_tracefork: failed to resume child"));
263 ret = my_waitpid (child_pid, &status, 0);
265 if (ret == child_pid && WIFSTOPPED (status)
266 && status >> 16 == PTRACE_EVENT_FORK)
269 ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
270 if (ret == 0 && second_pid != 0)
274 linux_supports_tracefork_flag = 1;
275 my_waitpid (second_pid, &second_status, 0);
276 ret = ptrace (PTRACE_KILL, second_pid, 0, 0);
278 warning (_("linux_test_for_tracefork: failed to kill second child"));
282 warning (_("linux_test_for_tracefork: unexpected result from waitpid "
283 "(%d, status 0x%x)"), ret, status);
285 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
287 warning (_("linux_test_for_tracefork: failed to kill child"));
288 my_waitpid (child_pid, &status, 0);
291 /* Return non-zero iff we have tracefork functionality available.
292 This function also sets linux_supports_tracefork_flag. */
295 linux_supports_tracefork (int pid)
297 if (linux_supports_tracefork_flag == -1)
298 linux_test_for_tracefork (pid);
299 return linux_supports_tracefork_flag;
303 linux_supports_tracevforkdone (int pid)
305 if (linux_supports_tracefork_flag == -1)
306 linux_test_for_tracefork (pid);
307 return linux_supports_tracevforkdone_flag;
312 linux_enable_event_reporting (ptid_t ptid)
314 int pid = ptid_get_lwp (ptid);
318 pid = ptid_get_pid (ptid);
320 if (! linux_supports_tracefork (pid))
323 options = PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK | PTRACE_O_TRACEEXEC
324 | PTRACE_O_TRACECLONE;
325 if (linux_supports_tracevforkdone (pid))
326 options |= PTRACE_O_TRACEVFORKDONE;
328 /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support
329 read-only process state. */
331 ptrace (PTRACE_SETOPTIONS, pid, 0, options);
335 child_post_attach (int pid)
337 linux_enable_event_reporting (pid_to_ptid (pid));
338 check_for_thread_db ();
342 linux_child_post_startup_inferior (ptid_t ptid)
344 linux_enable_event_reporting (ptid);
345 check_for_thread_db ();
349 child_follow_fork (struct target_ops *ops, int follow_child)
352 struct target_waitstatus last_status;
354 int parent_pid, child_pid;
356 get_last_target_status (&last_ptid, &last_status);
357 has_vforked = (last_status.kind == TARGET_WAITKIND_VFORKED);
358 parent_pid = ptid_get_lwp (last_ptid);
360 parent_pid = ptid_get_pid (last_ptid);
361 child_pid = last_status.value.related_pid;
365 /* We're already attached to the parent, by default. */
367 /* Before detaching from the child, remove all breakpoints from
368 it. (This won't actually modify the breakpoint list, but will
369 physically remove the breakpoints from the child.) */
370 /* If we vforked this will remove the breakpoints from the parent
371 also, but they'll be reinserted below. */
372 detach_breakpoints (child_pid);
374 /* Detach new forked process? */
379 target_terminal_ours ();
380 fprintf_filtered (gdb_stdlog,
381 "Detaching after fork from child process %d.\n",
385 ptrace (PTRACE_DETACH, child_pid, 0, 0);
389 struct fork_info *fp;
390 /* Retain child fork in ptrace (stopped) state. */
391 fp = find_fork_pid (child_pid);
393 fp = add_fork (child_pid);
394 fork_save_infrun_state (fp, 0);
399 gdb_assert (linux_supports_tracefork_flag >= 0);
400 if (linux_supports_tracevforkdone (0))
404 ptrace (PTRACE_CONT, parent_pid, 0, 0);
405 my_waitpid (parent_pid, &status, __WALL);
406 if ((status >> 16) != PTRACE_EVENT_VFORK_DONE)
407 warning (_("Unexpected waitpid result %06x when waiting for "
408 "vfork-done"), status);
412 /* We can't insert breakpoints until the child has
413 finished with the shared memory region. We need to
414 wait until that happens. Ideal would be to just
416 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
417 - waitpid (parent_pid, &status, __WALL);
418 However, most architectures can't handle a syscall
419 being traced on the way out if it wasn't traced on
422 We might also think to loop, continuing the child
423 until it exits or gets a SIGTRAP. One problem is
424 that the child might call ptrace with PTRACE_TRACEME.
426 There's no simple and reliable way to figure out when
427 the vforked child will be done with its copy of the
428 shared memory. We could step it out of the syscall,
429 two instructions, let it go, and then single-step the
430 parent once. When we have hardware single-step, this
431 would work; with software single-step it could still
432 be made to work but we'd have to be able to insert
433 single-step breakpoints in the child, and we'd have
434 to insert -just- the single-step breakpoint in the
435 parent. Very awkward.
437 In the end, the best we can do is to make sure it
438 runs for a little while. Hopefully it will be out of
439 range of any breakpoints we reinsert. Usually this
440 is only the single-step breakpoint at vfork's return
446 /* Since we vforked, breakpoints were removed in the parent
447 too. Put them back. */
448 reattach_breakpoints (parent_pid);
453 char child_pid_spelling[40];
455 /* Needed to keep the breakpoint lists in sync. */
457 detach_breakpoints (child_pid);
459 /* Before detaching from the parent, remove all breakpoints from it. */
460 remove_breakpoints ();
464 target_terminal_ours ();
465 fprintf_filtered (gdb_stdlog,
466 "Attaching after fork to child process %d.\n",
470 /* If we're vforking, we may want to hold on to the parent until
471 the child exits or execs. At exec time we can remove the old
472 breakpoints from the parent and detach it; at exit time we
473 could do the same (or even, sneakily, resume debugging it - the
474 child's exec has failed, or something similar).
476 This doesn't clean up "properly", because we can't call
477 target_detach, but that's OK; if the current target is "child",
478 then it doesn't need any further cleanups, and lin_lwp will
479 generally not encounter vfork (vfork is defined to fork
482 The holding part is very easy if we have VFORKDONE events;
483 but keeping track of both processes is beyond GDB at the
484 moment. So we don't expose the parent to the rest of GDB.
485 Instead we quietly hold onto it until such time as we can
489 linux_parent_pid = parent_pid;
490 else if (!detach_fork)
492 struct fork_info *fp;
493 /* Retain parent fork in ptrace (stopped) state. */
494 fp = find_fork_pid (parent_pid);
496 fp = add_fork (parent_pid);
497 fork_save_infrun_state (fp, 0);
501 target_detach (NULL, 0);
504 inferior_ptid = pid_to_ptid (child_pid);
506 /* Reinstall ourselves, since we might have been removed in
507 target_detach (which does other necessary cleanup). */
511 /* Reset breakpoints in the child as appropriate. */
512 follow_inferior_reset_breakpoints ();
519 linux_handle_extended_wait (int pid, int status,
520 struct target_waitstatus *ourstatus)
522 int event = status >> 16;
524 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK
525 || event == PTRACE_EVENT_CLONE)
527 unsigned long new_pid;
530 ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid);
532 /* If we haven't already seen the new PID stop, wait for it now. */
533 if (! pull_pid_from_list (&stopped_pids, new_pid))
535 /* The new child has a pending SIGSTOP. We can't affect it until it
536 hits the SIGSTOP, but we're already attached. */
537 ret = my_waitpid (new_pid, &status,
538 (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0);
540 perror_with_name (_("waiting for new child"));
541 else if (ret != new_pid)
542 internal_error (__FILE__, __LINE__,
543 _("wait returned unexpected PID %d"), ret);
544 else if (!WIFSTOPPED (status) || WSTOPSIG (status) != SIGSTOP)
545 internal_error (__FILE__, __LINE__,
546 _("wait returned unexpected status 0x%x"), status);
549 if (event == PTRACE_EVENT_FORK)
550 ourstatus->kind = TARGET_WAITKIND_FORKED;
551 else if (event == PTRACE_EVENT_VFORK)
552 ourstatus->kind = TARGET_WAITKIND_VFORKED;
554 ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
556 ourstatus->value.related_pid = new_pid;
557 return inferior_ptid;
560 if (event == PTRACE_EVENT_EXEC)
562 ourstatus->kind = TARGET_WAITKIND_EXECD;
563 ourstatus->value.execd_pathname
564 = xstrdup (child_pid_to_exec_file (pid));
566 if (linux_parent_pid)
568 detach_breakpoints (linux_parent_pid);
569 ptrace (PTRACE_DETACH, linux_parent_pid, 0, 0);
571 linux_parent_pid = 0;
574 return inferior_ptid;
577 internal_error (__FILE__, __LINE__,
578 _("unknown ptrace event %d"), event);
583 child_insert_fork_catchpoint (int pid)
585 if (! linux_supports_tracefork (pid))
586 error (_("Your system does not support fork catchpoints."));
590 child_insert_vfork_catchpoint (int pid)
592 if (!linux_supports_tracefork (pid))
593 error (_("Your system does not support vfork catchpoints."));
597 child_insert_exec_catchpoint (int pid)
599 if (!linux_supports_tracefork (pid))
600 error (_("Your system does not support exec catchpoints."));
603 /* On GNU/Linux there are no real LWP's. The closest thing to LWP's
604 are processes sharing the same VM space. A multi-threaded process
605 is basically a group of such processes. However, such a grouping
606 is almost entirely a user-space issue; the kernel doesn't enforce
607 such a grouping at all (this might change in the future). In
608 general, we'll rely on the threads library (i.e. the GNU/Linux
609 Threads library) to provide such a grouping.
611 It is perfectly well possible to write a multi-threaded application
612 without the assistance of a threads library, by using the clone
613 system call directly. This module should be able to give some
614 rudimentary support for debugging such applications if developers
615 specify the CLONE_PTRACE flag in the clone system call, and are
616 using the Linux kernel 2.4 or above.
618 Note that there are some peculiarities in GNU/Linux that affect
621 - In general one should specify the __WCLONE flag to waitpid in
622 order to make it report events for any of the cloned processes
623 (and leave it out for the initial process). However, if a cloned
624 process has exited the exit status is only reported if the
625 __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
626 we cannot use it since GDB must work on older systems too.
628 - When a traced, cloned process exits and is waited for by the
629 debugger, the kernel reassigns it to the original parent and
630 keeps it around as a "zombie". Somehow, the GNU/Linux Threads
631 library doesn't notice this, which leads to the "zombie problem":
632 When debugged a multi-threaded process that spawns a lot of
633 threads will run out of processes, even if the threads exit,
634 because the "zombies" stay around. */
636 /* List of known LWPs. */
637 static struct lwp_info *lwp_list;
639 /* Number of LWPs in the list. */
643 #define GET_LWP(ptid) ptid_get_lwp (ptid)
644 #define GET_PID(ptid) ptid_get_pid (ptid)
645 #define is_lwp(ptid) (GET_LWP (ptid) != 0)
646 #define BUILD_LWP(lwp, pid) ptid_build (pid, lwp, 0)
648 /* If the last reported event was a SIGTRAP, this variable is set to
649 the process id of the LWP/thread that got it. */
653 /* Since we cannot wait (in linux_nat_wait) for the initial process and
654 any cloned processes with a single call to waitpid, we have to use
655 the WNOHANG flag and call waitpid in a loop. To optimize
656 things a bit we use `sigsuspend' to wake us up when a process has
657 something to report (it will send us a SIGCHLD if it has). To make
658 this work we have to juggle with the signal mask. We save the
659 original signal mask such that we can restore it before creating a
660 new process in order to avoid blocking certain signals in the
661 inferior. We then block SIGCHLD during the waitpid/sigsuspend
664 /* Original signal mask. */
665 static sigset_t normal_mask;
667 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
668 _initialize_linux_nat. */
669 static sigset_t suspend_mask;
671 /* Signals to block to make that sigsuspend work. */
672 static sigset_t blocked_mask;
675 /* Prototypes for local functions. */
676 static int stop_wait_callback (struct lwp_info *lp, void *data);
677 static int linux_nat_thread_alive (ptid_t ptid);
679 /* Convert wait status STATUS to a string. Used for printing debug
683 status_to_str (int status)
687 if (WIFSTOPPED (status))
688 snprintf (buf, sizeof (buf), "%s (stopped)",
689 strsignal (WSTOPSIG (status)));
690 else if (WIFSIGNALED (status))
691 snprintf (buf, sizeof (buf), "%s (terminated)",
692 strsignal (WSTOPSIG (status)));
694 snprintf (buf, sizeof (buf), "%d (exited)", WEXITSTATUS (status));
699 /* Initialize the list of LWPs. Note that this module, contrary to
700 what GDB's generic threads layer does for its thread list,
701 re-initializes the LWP lists whenever we mourn or detach (which
702 doesn't involve mourning) the inferior. */
707 struct lwp_info *lp, *lpnext;
709 for (lp = lwp_list; lp; lp = lpnext)
719 /* Add the LWP specified by PID to the list. Return a pointer to the
720 structure describing the new LWP. */
722 static struct lwp_info *
723 add_lwp (ptid_t ptid)
727 gdb_assert (is_lwp (ptid));
729 lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info));
731 memset (lp, 0, sizeof (struct lwp_info));
733 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
744 /* Remove the LWP specified by PID from the list. */
747 delete_lwp (ptid_t ptid)
749 struct lwp_info *lp, *lpprev;
753 for (lp = lwp_list; lp; lpprev = lp, lp = lp->next)
754 if (ptid_equal (lp->ptid, ptid))
763 lpprev->next = lp->next;
770 /* Return a pointer to the structure describing the LWP corresponding
771 to PID. If no corresponding LWP could be found, return NULL. */
773 static struct lwp_info *
774 find_lwp_pid (ptid_t ptid)
780 lwp = GET_LWP (ptid);
782 lwp = GET_PID (ptid);
784 for (lp = lwp_list; lp; lp = lp->next)
785 if (lwp == GET_LWP (lp->ptid))
791 /* Call CALLBACK with its second argument set to DATA for every LWP in
792 the list. If CALLBACK returns 1 for a particular LWP, return a
793 pointer to the structure describing that LWP immediately.
794 Otherwise return NULL. */
797 iterate_over_lwps (int (*callback) (struct lwp_info *, void *), void *data)
799 struct lwp_info *lp, *lpnext;
801 for (lp = lwp_list; lp; lp = lpnext)
804 if ((*callback) (lp, data))
811 /* Update our internal state when changing from one fork (checkpoint,
812 et cetera) to another indicated by NEW_PTID. We can only switch
813 single-threaded applications, so we only create one new LWP, and
814 the previous list is discarded. */
817 linux_nat_switch_fork (ptid_t new_ptid)
822 lp = add_lwp (new_ptid);
826 /* Record a PTID for later deletion. */
831 struct saved_ptids *next;
833 static struct saved_ptids *threads_to_delete;
836 record_dead_thread (ptid_t ptid)
838 struct saved_ptids *p = xmalloc (sizeof (struct saved_ptids));
840 p->next = threads_to_delete;
841 threads_to_delete = p;
844 /* Delete any dead threads which are not the current thread. */
849 struct saved_ptids **p = &threads_to_delete;
852 if (! ptid_equal ((*p)->ptid, inferior_ptid))
854 struct saved_ptids *tmp = *p;
855 delete_thread (tmp->ptid);
863 /* Callback for iterate_over_threads that finds a thread corresponding
867 find_thread_from_lwp (struct thread_info *thr, void *dummy)
869 ptid_t *ptid_p = dummy;
871 if (GET_LWP (thr->ptid) && GET_LWP (thr->ptid) == GET_LWP (*ptid_p))
877 /* Handle the exit of a single thread LP. */
880 exit_lwp (struct lwp_info *lp)
882 if (in_thread_list (lp->ptid))
884 /* Core GDB cannot deal with us deleting the current thread. */
885 if (!ptid_equal (lp->ptid, inferior_ptid))
886 delete_thread (lp->ptid);
888 record_dead_thread (lp->ptid);
889 printf_unfiltered (_("[%s exited]\n"),
890 target_pid_to_str (lp->ptid));
894 /* Even if LP->PTID is not in the global GDB thread list, the
895 LWP may be - with an additional thread ID. We don't need
896 to print anything in this case; thread_db is in use and
897 already took care of that. But it didn't delete the thread
898 in order to handle zombies correctly. */
900 struct thread_info *thr;
902 thr = iterate_over_threads (find_thread_from_lwp, &lp->ptid);
903 if (thr && !ptid_equal (thr->ptid, inferior_ptid))
904 delete_thread (thr->ptid);
906 record_dead_thread (thr->ptid);
909 delete_lwp (lp->ptid);
912 /* Attach to the LWP specified by PID. If VERBOSE is non-zero, print
913 a message telling the user that a new LWP has been added to the
917 lin_lwp_attach_lwp (ptid_t ptid, int verbose)
919 struct lwp_info *lp, *found_lp;
921 gdb_assert (is_lwp (ptid));
923 /* Make sure SIGCHLD is blocked. We don't want SIGCHLD events
924 to interrupt either the ptrace() or waitpid() calls below. */
925 if (!sigismember (&blocked_mask, SIGCHLD))
927 sigaddset (&blocked_mask, SIGCHLD);
928 sigprocmask (SIG_BLOCK, &blocked_mask, NULL);
932 printf_filtered (_("[New %s]\n"), target_pid_to_str (ptid));
934 found_lp = lp = find_lwp_pid (ptid);
938 /* We assume that we're already attached to any LWP that has an id
939 equal to the overall process id, and to any LWP that is already
940 in our list of LWPs. If we're not seeing exit events from threads
941 and we've had PID wraparound since we last tried to stop all threads,
942 this assumption might be wrong; fortunately, this is very unlikely
944 if (GET_LWP (ptid) != GET_PID (ptid) && found_lp == NULL)
949 if (ptrace (PTRACE_ATTACH, GET_LWP (ptid), 0, 0) < 0)
950 error (_("Can't attach %s: %s"), target_pid_to_str (ptid),
951 safe_strerror (errno));
954 fprintf_unfiltered (gdb_stdlog,
955 "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
956 target_pid_to_str (ptid));
958 pid = my_waitpid (GET_LWP (ptid), &status, 0);
959 if (pid == -1 && errno == ECHILD)
961 /* Try again with __WCLONE to check cloned processes. */
962 pid = my_waitpid (GET_LWP (ptid), &status, __WCLONE);
966 gdb_assert (pid == GET_LWP (ptid)
967 && WIFSTOPPED (status) && WSTOPSIG (status));
969 target_post_attach (pid);
975 fprintf_unfiltered (gdb_stdlog,
976 "LLAL: waitpid %s received %s\n",
977 target_pid_to_str (ptid),
978 status_to_str (status));
983 /* We assume that the LWP representing the original process is
984 already stopped. Mark it as stopped in the data structure
985 that the linux ptrace layer uses to keep track of threads.
986 Note that this won't have already been done since the main
987 thread will have, we assume, been stopped by an attach from a
994 linux_nat_attach (char *args, int from_tty)
1000 /* FIXME: We should probably accept a list of process id's, and
1001 attach all of them. */
1002 linux_ops->to_attach (args, from_tty);
1004 /* Add the initial process as the first LWP to the list. */
1005 inferior_ptid = BUILD_LWP (GET_PID (inferior_ptid), GET_PID (inferior_ptid));
1006 lp = add_lwp (inferior_ptid);
1008 /* Make sure the initial process is stopped. The user-level threads
1009 layer might want to poke around in the inferior, and that won't
1010 work if things haven't stabilized yet. */
1011 pid = my_waitpid (GET_PID (inferior_ptid), &status, 0);
1012 if (pid == -1 && errno == ECHILD)
1014 warning (_("%s is a cloned process"), target_pid_to_str (inferior_ptid));
1016 /* Try again with __WCLONE to check cloned processes. */
1017 pid = my_waitpid (GET_PID (inferior_ptid), &status, __WCLONE);
1021 gdb_assert (pid == GET_PID (inferior_ptid)
1022 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP);
1026 /* Fake the SIGSTOP that core GDB expects. */
1027 lp->status = W_STOPCODE (SIGSTOP);
1029 if (debug_linux_nat)
1031 fprintf_unfiltered (gdb_stdlog,
1032 "LLA: waitpid %ld, faking SIGSTOP\n", (long) pid);
1037 detach_callback (struct lwp_info *lp, void *data)
1039 gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status));
1041 if (debug_linux_nat && lp->status)
1042 fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n",
1043 strsignal (WSTOPSIG (lp->status)),
1044 target_pid_to_str (lp->ptid));
1046 while (lp->signalled && lp->stopped)
1049 if (ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0,
1050 WSTOPSIG (lp->status)) < 0)
1051 error (_("Can't continue %s: %s"), target_pid_to_str (lp->ptid),
1052 safe_strerror (errno));
1054 if (debug_linux_nat)
1055 fprintf_unfiltered (gdb_stdlog,
1056 "DC: PTRACE_CONTINUE (%s, 0, %s) (OK)\n",
1057 target_pid_to_str (lp->ptid),
1058 status_to_str (lp->status));
1063 /* FIXME drow/2003-08-26: There was a call to stop_wait_callback
1064 here. But since lp->signalled was cleared above,
1065 stop_wait_callback didn't do anything; the process was left
1066 running. Shouldn't we be waiting for it to stop?
1067 I've removed the call, since stop_wait_callback now does do
1068 something when called with lp->signalled == 0. */
1070 gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status));
1073 /* We don't actually detach from the LWP that has an id equal to the
1074 overall process id just yet. */
1075 if (GET_LWP (lp->ptid) != GET_PID (lp->ptid))
1078 if (ptrace (PTRACE_DETACH, GET_LWP (lp->ptid), 0,
1079 WSTOPSIG (lp->status)) < 0)
1080 error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid),
1081 safe_strerror (errno));
1083 if (debug_linux_nat)
1084 fprintf_unfiltered (gdb_stdlog,
1085 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1086 target_pid_to_str (lp->ptid),
1087 strsignal (WSTOPSIG (lp->status)));
1089 delete_lwp (lp->ptid);
1096 linux_nat_detach (char *args, int from_tty)
1098 iterate_over_lwps (detach_callback, NULL);
1100 /* Only the initial process should be left right now. */
1101 gdb_assert (num_lwps == 1);
1103 trap_ptid = null_ptid;
1105 /* Destroy LWP info; it's no longer valid. */
1108 /* Restore the original signal mask. */
1109 sigprocmask (SIG_SETMASK, &normal_mask, NULL);
1110 sigemptyset (&blocked_mask);
1112 inferior_ptid = pid_to_ptid (GET_PID (inferior_ptid));
1113 linux_ops->to_detach (args, from_tty);
1119 resume_callback (struct lwp_info *lp, void *data)
1121 if (lp->stopped && lp->status == 0)
1123 struct thread_info *tp;
1125 linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)),
1126 0, TARGET_SIGNAL_0);
1127 if (debug_linux_nat)
1128 fprintf_unfiltered (gdb_stdlog,
1129 "RC: PTRACE_CONT %s, 0, 0 (resume sibling)\n",
1130 target_pid_to_str (lp->ptid));
1139 resume_clear_callback (struct lwp_info *lp, void *data)
1146 resume_set_callback (struct lwp_info *lp, void *data)
1153 linux_nat_resume (ptid_t ptid, int step, enum target_signal signo)
1155 struct lwp_info *lp;
1158 if (debug_linux_nat)
1159 fprintf_unfiltered (gdb_stdlog,
1160 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1161 step ? "step" : "resume",
1162 target_pid_to_str (ptid),
1163 signo ? strsignal (signo) : "0",
1164 target_pid_to_str (inferior_ptid));
1168 /* A specific PTID means `step only this process id'. */
1169 resume_all = (PIDGET (ptid) == -1);
1172 iterate_over_lwps (resume_set_callback, NULL);
1174 iterate_over_lwps (resume_clear_callback, NULL);
1176 /* If PID is -1, it's the current inferior that should be
1177 handled specially. */
1178 if (PIDGET (ptid) == -1)
1179 ptid = inferior_ptid;
1181 lp = find_lwp_pid (ptid);
1184 ptid = pid_to_ptid (GET_LWP (lp->ptid));
1186 /* Remember if we're stepping. */
1189 /* Mark this LWP as resumed. */
1192 /* If we have a pending wait status for this thread, there is no
1193 point in resuming the process. But first make sure that
1194 linux_nat_wait won't preemptively handle the event - we
1195 should never take this short-circuit if we are going to
1196 leave LP running, since we have skipped resuming all the
1197 other threads. This bit of code needs to be synchronized
1198 with linux_nat_wait. */
1200 if (lp->status && WIFSTOPPED (lp->status))
1202 int saved_signo = target_signal_from_host (WSTOPSIG (lp->status));
1204 if (signal_stop_state (saved_signo) == 0
1205 && signal_print_state (saved_signo) == 0
1206 && signal_pass_state (saved_signo) == 1)
1208 if (debug_linux_nat)
1209 fprintf_unfiltered (gdb_stdlog,
1210 "LLR: Not short circuiting for ignored "
1211 "status 0x%x\n", lp->status);
1213 /* FIXME: What should we do if we are supposed to continue
1214 this thread with a signal? */
1215 gdb_assert (signo == TARGET_SIGNAL_0);
1216 signo = saved_signo;
1223 /* FIXME: What should we do if we are supposed to continue
1224 this thread with a signal? */
1225 gdb_assert (signo == TARGET_SIGNAL_0);
1227 if (debug_linux_nat)
1228 fprintf_unfiltered (gdb_stdlog,
1229 "LLR: Short circuiting for status 0x%x\n",
1235 /* Mark LWP as not stopped to prevent it from being continued by
1241 iterate_over_lwps (resume_callback, NULL);
1243 linux_ops->to_resume (ptid, step, signo);
1244 if (debug_linux_nat)
1245 fprintf_unfiltered (gdb_stdlog,
1246 "LLR: %s %s, %s (resume event thread)\n",
1247 step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1248 target_pid_to_str (ptid),
1249 signo ? strsignal (signo) : "0");
1252 /* Issue kill to specified lwp. */
1254 static int tkill_failed;
1257 kill_lwp (int lwpid, int signo)
1261 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1262 fails, then we are not using nptl threads and we should be using kill. */
1264 #ifdef HAVE_TKILL_SYSCALL
1267 int ret = syscall (__NR_tkill, lwpid, signo);
1268 if (errno != ENOSYS)
1275 return kill (lwpid, signo);
1278 /* Handle a GNU/Linux extended wait response. Most of the work we
1279 just pass off to linux_handle_extended_wait, but if it reports a
1280 clone event we need to add the new LWP to our list (and not report
1281 the trap to higher layers). This function returns non-zero if
1282 the event should be ignored and we should wait again. */
1285 linux_nat_handle_extended (struct lwp_info *lp, int status)
1287 linux_handle_extended_wait (GET_LWP (lp->ptid), status,
1290 /* TARGET_WAITKIND_SPURIOUS is used to indicate clone events. */
1291 if (lp->waitstatus.kind == TARGET_WAITKIND_SPURIOUS)
1293 struct lwp_info *new_lp;
1294 new_lp = add_lwp (BUILD_LWP (lp->waitstatus.value.related_pid,
1295 GET_PID (inferior_ptid)));
1297 new_lp->stopped = 1;
1299 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
1301 if (debug_linux_nat)
1302 fprintf_unfiltered (gdb_stdlog,
1303 "LLHE: Got clone event from LWP %ld, resuming\n",
1304 GET_LWP (lp->ptid));
1305 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
1313 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
1317 wait_lwp (struct lwp_info *lp)
1321 int thread_dead = 0;
1323 gdb_assert (!lp->stopped);
1324 gdb_assert (lp->status == 0);
1326 pid = my_waitpid (GET_LWP (lp->ptid), &status, 0);
1327 if (pid == -1 && errno == ECHILD)
1329 pid = my_waitpid (GET_LWP (lp->ptid), &status, __WCLONE);
1330 if (pid == -1 && errno == ECHILD)
1332 /* The thread has previously exited. We need to delete it
1333 now because, for some vendor 2.4 kernels with NPTL
1334 support backported, there won't be an exit event unless
1335 it is the main thread. 2.6 kernels will report an exit
1336 event for each thread that exits, as expected. */
1338 if (debug_linux_nat)
1339 fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
1340 target_pid_to_str (lp->ptid));
1346 gdb_assert (pid == GET_LWP (lp->ptid));
1348 if (debug_linux_nat)
1350 fprintf_unfiltered (gdb_stdlog,
1351 "WL: waitpid %s received %s\n",
1352 target_pid_to_str (lp->ptid),
1353 status_to_str (status));
1357 /* Check if the thread has exited. */
1358 if (WIFEXITED (status) || WIFSIGNALED (status))
1361 if (debug_linux_nat)
1362 fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n",
1363 target_pid_to_str (lp->ptid));
1372 gdb_assert (WIFSTOPPED (status));
1374 /* Handle GNU/Linux's extended waitstatus for trace events. */
1375 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
1377 if (debug_linux_nat)
1378 fprintf_unfiltered (gdb_stdlog,
1379 "WL: Handling extended status 0x%06x\n",
1381 if (linux_nat_handle_extended (lp, status))
1382 return wait_lwp (lp);
1388 /* Send a SIGSTOP to LP. */
1391 stop_callback (struct lwp_info *lp, void *data)
1393 if (!lp->stopped && !lp->signalled)
1397 if (debug_linux_nat)
1399 fprintf_unfiltered (gdb_stdlog,
1400 "SC: kill %s **<SIGSTOP>**\n",
1401 target_pid_to_str (lp->ptid));
1404 ret = kill_lwp (GET_LWP (lp->ptid), SIGSTOP);
1405 if (debug_linux_nat)
1407 fprintf_unfiltered (gdb_stdlog,
1408 "SC: lwp kill %d %s\n",
1410 errno ? safe_strerror (errno) : "ERRNO-OK");
1414 gdb_assert (lp->status == 0);
1420 /* Wait until LP is stopped. If DATA is non-null it is interpreted as
1421 a pointer to a set of signals to be flushed immediately. */
1424 stop_wait_callback (struct lwp_info *lp, void *data)
1426 sigset_t *flush_mask = data;
1432 status = wait_lwp (lp);
1436 /* Ignore any signals in FLUSH_MASK. */
1437 if (flush_mask && sigismember (flush_mask, WSTOPSIG (status)))
1446 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
1447 if (debug_linux_nat)
1448 fprintf_unfiltered (gdb_stdlog,
1449 "PTRACE_CONT %s, 0, 0 (%s)\n",
1450 target_pid_to_str (lp->ptid),
1451 errno ? safe_strerror (errno) : "OK");
1453 return stop_wait_callback (lp, flush_mask);
1456 if (WSTOPSIG (status) != SIGSTOP)
1458 if (WSTOPSIG (status) == SIGTRAP)
1460 /* If a LWP other than the LWP that we're reporting an
1461 event for has hit a GDB breakpoint (as opposed to
1462 some random trap signal), then just arrange for it to
1463 hit it again later. We don't keep the SIGTRAP status
1464 and don't forward the SIGTRAP signal to the LWP. We
1465 will handle the current event, eventually we will
1466 resume all LWPs, and this one will get its breakpoint
1469 If we do not do this, then we run the risk that the
1470 user will delete or disable the breakpoint, but the
1471 thread will have already tripped on it. */
1473 /* Now resume this LWP and get the SIGSTOP event. */
1475 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
1476 if (debug_linux_nat)
1478 fprintf_unfiltered (gdb_stdlog,
1479 "PTRACE_CONT %s, 0, 0 (%s)\n",
1480 target_pid_to_str (lp->ptid),
1481 errno ? safe_strerror (errno) : "OK");
1483 fprintf_unfiltered (gdb_stdlog,
1484 "SWC: Candidate SIGTRAP event in %s\n",
1485 target_pid_to_str (lp->ptid));
1487 /* Hold the SIGTRAP for handling by linux_nat_wait. */
1488 stop_wait_callback (lp, data);
1489 /* If there's another event, throw it back into the queue. */
1492 if (debug_linux_nat)
1494 fprintf_unfiltered (gdb_stdlog,
1495 "SWC: kill %s, %s\n",
1496 target_pid_to_str (lp->ptid),
1497 status_to_str ((int) status));
1499 kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (lp->status));
1501 /* Save the sigtrap event. */
1502 lp->status = status;
1507 /* The thread was stopped with a signal other than
1508 SIGSTOP, and didn't accidentally trip a breakpoint. */
1510 if (debug_linux_nat)
1512 fprintf_unfiltered (gdb_stdlog,
1513 "SWC: Pending event %s in %s\n",
1514 status_to_str ((int) status),
1515 target_pid_to_str (lp->ptid));
1517 /* Now resume this LWP and get the SIGSTOP event. */
1519 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
1520 if (debug_linux_nat)
1521 fprintf_unfiltered (gdb_stdlog,
1522 "SWC: PTRACE_CONT %s, 0, 0 (%s)\n",
1523 target_pid_to_str (lp->ptid),
1524 errno ? safe_strerror (errno) : "OK");
1526 /* Hold this event/waitstatus while we check to see if
1527 there are any more (we still want to get that SIGSTOP). */
1528 stop_wait_callback (lp, data);
1529 /* If the lp->status field is still empty, use it to hold
1530 this event. If not, then this event must be returned
1531 to the event queue of the LWP. */
1532 if (lp->status == 0)
1533 lp->status = status;
1536 if (debug_linux_nat)
1538 fprintf_unfiltered (gdb_stdlog,
1539 "SWC: kill %s, %s\n",
1540 target_pid_to_str (lp->ptid),
1541 status_to_str ((int) status));
1543 kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (status));
1550 /* We caught the SIGSTOP that we intended to catch, so
1551 there's no SIGSTOP pending. */
1560 /* Check whether PID has any pending signals in FLUSH_MASK. If so set
1561 the appropriate bits in PENDING, and return 1 - otherwise return 0. */
1564 linux_nat_has_pending (int pid, sigset_t *pending, sigset_t *flush_mask)
1566 sigset_t blocked, ignored;
1569 linux_proc_pending_signals (pid, pending, &blocked, &ignored);
1574 for (i = 1; i < NSIG; i++)
1575 if (sigismember (pending, i))
1576 if (!sigismember (flush_mask, i)
1577 || sigismember (&blocked, i)
1578 || sigismember (&ignored, i))
1579 sigdelset (pending, i);
1581 if (sigisemptyset (pending))
1587 /* DATA is interpreted as a mask of signals to flush. If LP has
1588 signals pending, and they are all in the flush mask, then arrange
1589 to flush them. LP should be stopped, as should all other threads
1590 it might share a signal queue with. */
1593 flush_callback (struct lwp_info *lp, void *data)
1595 sigset_t *flush_mask = data;
1596 sigset_t pending, intersection, blocked, ignored;
1599 /* Normally, when an LWP exits, it is removed from the LWP list. The
1600 last LWP isn't removed till later, however. So if there is only
1601 one LWP on the list, make sure it's alive. */
1602 if (lwp_list == lp && lp->next == NULL)
1603 if (!linux_nat_thread_alive (lp->ptid))
1606 /* Just because the LWP is stopped doesn't mean that new signals
1607 can't arrive from outside, so this function must be careful of
1608 race conditions. However, because all threads are stopped, we
1609 can assume that the pending mask will not shrink unless we resume
1610 the LWP, and that it will then get another signal. We can't
1611 control which one, however. */
1615 if (debug_linux_nat)
1616 printf_unfiltered (_("FC: LP has pending status %06x\n"), lp->status);
1617 if (WIFSTOPPED (lp->status) && sigismember (flush_mask, WSTOPSIG (lp->status)))
1621 while (linux_nat_has_pending (GET_LWP (lp->ptid), &pending, flush_mask))
1626 ret = ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
1627 if (debug_linux_nat)
1628 fprintf_unfiltered (gdb_stderr,
1629 "FC: Sent PTRACE_CONT, ret %d %d\n", ret, errno);
1632 stop_wait_callback (lp, flush_mask);
1633 if (debug_linux_nat)
1634 fprintf_unfiltered (gdb_stderr,
1635 "FC: Wait finished; saved status is %d\n",
1642 /* Return non-zero if LP has a wait status pending. */
1645 status_callback (struct lwp_info *lp, void *data)
1647 /* Only report a pending wait status if we pretend that this has
1648 indeed been resumed. */
1649 return (lp->status != 0 && lp->resumed);
1652 /* Return non-zero if LP isn't stopped. */
1655 running_callback (struct lwp_info *lp, void *data)
1657 return (lp->stopped == 0 || (lp->status != 0 && lp->resumed));
1660 /* Count the LWP's that have had events. */
1663 count_events_callback (struct lwp_info *lp, void *data)
1667 gdb_assert (count != NULL);
1669 /* Count only LWPs that have a SIGTRAP event pending. */
1671 && WIFSTOPPED (lp->status) && WSTOPSIG (lp->status) == SIGTRAP)
1677 /* Select the LWP (if any) that is currently being single-stepped. */
1680 select_singlestep_lwp_callback (struct lwp_info *lp, void *data)
1682 if (lp->step && lp->status != 0)
1688 /* Select the Nth LWP that has had a SIGTRAP event. */
1691 select_event_lwp_callback (struct lwp_info *lp, void *data)
1693 int *selector = data;
1695 gdb_assert (selector != NULL);
1697 /* Select only LWPs that have a SIGTRAP event pending. */
1699 && WIFSTOPPED (lp->status) && WSTOPSIG (lp->status) == SIGTRAP)
1700 if ((*selector)-- == 0)
1707 cancel_breakpoints_callback (struct lwp_info *lp, void *data)
1709 struct lwp_info *event_lp = data;
1711 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
1715 /* If a LWP other than the LWP that we're reporting an event for has
1716 hit a GDB breakpoint (as opposed to some random trap signal),
1717 then just arrange for it to hit it again later. We don't keep
1718 the SIGTRAP status and don't forward the SIGTRAP signal to the
1719 LWP. We will handle the current event, eventually we will resume
1720 all LWPs, and this one will get its breakpoint trap again.
1722 If we do not do this, then we run the risk that the user will
1723 delete or disable the breakpoint, but the LWP will have already
1727 && WIFSTOPPED (lp->status) && WSTOPSIG (lp->status) == SIGTRAP
1728 && breakpoint_inserted_here_p (read_pc_pid (lp->ptid) -
1729 DECR_PC_AFTER_BREAK))
1731 if (debug_linux_nat)
1732 fprintf_unfiltered (gdb_stdlog,
1733 "CBC: Push back breakpoint for %s\n",
1734 target_pid_to_str (lp->ptid));
1736 /* Back up the PC if necessary. */
1737 if (DECR_PC_AFTER_BREAK)
1738 write_pc_pid (read_pc_pid (lp->ptid) - DECR_PC_AFTER_BREAK, lp->ptid);
1740 /* Throw away the SIGTRAP. */
1747 /* Select one LWP out of those that have events pending. */
1750 select_event_lwp (struct lwp_info **orig_lp, int *status)
1753 int random_selector;
1754 struct lwp_info *event_lp;
1756 /* Record the wait status for the original LWP. */
1757 (*orig_lp)->status = *status;
1759 /* Give preference to any LWP that is being single-stepped. */
1760 event_lp = iterate_over_lwps (select_singlestep_lwp_callback, NULL);
1761 if (event_lp != NULL)
1763 if (debug_linux_nat)
1764 fprintf_unfiltered (gdb_stdlog,
1765 "SEL: Select single-step %s\n",
1766 target_pid_to_str (event_lp->ptid));
1770 /* No single-stepping LWP. Select one at random, out of those
1771 which have had SIGTRAP events. */
1773 /* First see how many SIGTRAP events we have. */
1774 iterate_over_lwps (count_events_callback, &num_events);
1776 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
1777 random_selector = (int)
1778 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
1780 if (debug_linux_nat && num_events > 1)
1781 fprintf_unfiltered (gdb_stdlog,
1782 "SEL: Found %d SIGTRAP events, selecting #%d\n",
1783 num_events, random_selector);
1785 event_lp = iterate_over_lwps (select_event_lwp_callback,
1789 if (event_lp != NULL)
1791 /* Switch the event LWP. */
1792 *orig_lp = event_lp;
1793 *status = event_lp->status;
1796 /* Flush the wait status for the event LWP. */
1797 (*orig_lp)->status = 0;
1800 /* Return non-zero if LP has been resumed. */
1803 resumed_callback (struct lwp_info *lp, void *data)
1808 /* Stop an active thread, verify it still exists, then resume it. */
1811 stop_and_resume_callback (struct lwp_info *lp, void *data)
1813 struct lwp_info *ptr;
1815 if (!lp->stopped && !lp->signalled)
1817 stop_callback (lp, NULL);
1818 stop_wait_callback (lp, NULL);
1819 /* Resume if the lwp still exists. */
1820 for (ptr = lwp_list; ptr; ptr = ptr->next)
1823 resume_callback (lp, NULL);
1824 resume_set_callback (lp, NULL);
1831 linux_nat_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
1833 struct lwp_info *lp = NULL;
1836 pid_t pid = PIDGET (ptid);
1837 sigset_t flush_mask;
1839 /* The first time we get here after starting a new inferior, we may
1840 not have added it to the LWP list yet - this is the earliest
1841 moment at which we know its PID. */
1844 gdb_assert (!is_lwp (inferior_ptid));
1846 inferior_ptid = BUILD_LWP (GET_PID (inferior_ptid),
1847 GET_PID (inferior_ptid));
1848 lp = add_lwp (inferior_ptid);
1852 sigemptyset (&flush_mask);
1854 /* Make sure SIGCHLD is blocked. */
1855 if (!sigismember (&blocked_mask, SIGCHLD))
1857 sigaddset (&blocked_mask, SIGCHLD);
1858 sigprocmask (SIG_BLOCK, &blocked_mask, NULL);
1863 /* Make sure there is at least one LWP that has been resumed. */
1864 gdb_assert (iterate_over_lwps (resumed_callback, NULL));
1866 /* First check if there is a LWP with a wait status pending. */
1869 /* Any LWP that's been resumed will do. */
1870 lp = iterate_over_lwps (status_callback, NULL);
1873 status = lp->status;
1876 if (debug_linux_nat && status)
1877 fprintf_unfiltered (gdb_stdlog,
1878 "LLW: Using pending wait status %s for %s.\n",
1879 status_to_str (status),
1880 target_pid_to_str (lp->ptid));
1883 /* But if we don't fine one, we'll have to wait, and check both
1884 cloned and uncloned processes. We start with the cloned
1886 options = __WCLONE | WNOHANG;
1888 else if (is_lwp (ptid))
1890 if (debug_linux_nat)
1891 fprintf_unfiltered (gdb_stdlog,
1892 "LLW: Waiting for specific LWP %s.\n",
1893 target_pid_to_str (ptid));
1895 /* We have a specific LWP to check. */
1896 lp = find_lwp_pid (ptid);
1898 status = lp->status;
1901 if (debug_linux_nat && status)
1902 fprintf_unfiltered (gdb_stdlog,
1903 "LLW: Using pending wait status %s for %s.\n",
1904 status_to_str (status),
1905 target_pid_to_str (lp->ptid));
1907 /* If we have to wait, take into account whether PID is a cloned
1908 process or not. And we have to convert it to something that
1909 the layer beneath us can understand. */
1910 options = lp->cloned ? __WCLONE : 0;
1911 pid = GET_LWP (ptid);
1914 if (status && lp->signalled)
1916 /* A pending SIGSTOP may interfere with the normal stream of
1917 events. In a typical case where interference is a problem,
1918 we have a SIGSTOP signal pending for LWP A while
1919 single-stepping it, encounter an event in LWP B, and take the
1920 pending SIGSTOP while trying to stop LWP A. After processing
1921 the event in LWP B, LWP A is continued, and we'll never see
1922 the SIGTRAP associated with the last time we were
1923 single-stepping LWP A. */
1925 /* Resume the thread. It should halt immediately returning the
1927 registers_changed ();
1928 linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)),
1929 lp->step, TARGET_SIGNAL_0);
1930 if (debug_linux_nat)
1931 fprintf_unfiltered (gdb_stdlog,
1932 "LLW: %s %s, 0, 0 (expect SIGSTOP)\n",
1933 lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1934 target_pid_to_str (lp->ptid));
1936 gdb_assert (lp->resumed);
1938 /* This should catch the pending SIGSTOP. */
1939 stop_wait_callback (lp, NULL);
1942 set_sigint_trap (); /* Causes SIGINT to be passed on to the
1943 attached process. */
1950 lwpid = my_waitpid (pid, &status, options);
1953 gdb_assert (pid == -1 || lwpid == pid);
1955 if (debug_linux_nat)
1957 fprintf_unfiltered (gdb_stdlog,
1958 "LLW: waitpid %ld received %s\n",
1959 (long) lwpid, status_to_str (status));
1962 lp = find_lwp_pid (pid_to_ptid (lwpid));
1964 /* Check for stop events reported by a process we didn't
1965 already know about - anything not already in our LWP
1968 If we're expecting to receive stopped processes after
1969 fork, vfork, and clone events, then we'll just add the
1970 new one to our list and go back to waiting for the event
1971 to be reported - the stopped process might be returned
1972 from waitpid before or after the event is. */
1973 if (WIFSTOPPED (status) && !lp)
1975 linux_record_stopped_pid (lwpid);
1980 /* Make sure we don't report an event for the exit of an LWP not in
1981 our list, i.e. not part of the current process. This can happen
1982 if we detach from a program we original forked and then it
1984 if (!WIFSTOPPED (status) && !lp)
1990 /* NOTE drow/2003-06-17: This code seems to be meant for debugging
1991 CLONE_PTRACE processes which do not use the thread library -
1992 otherwise we wouldn't find the new LWP this way. That doesn't
1993 currently work, and the following code is currently unreachable
1994 due to the two blocks above. If it's fixed some day, this code
1995 should be broken out into a function so that we can also pick up
1996 LWPs from the new interface. */
1999 lp = add_lwp (BUILD_LWP (lwpid, GET_PID (inferior_ptid)));
2000 if (options & __WCLONE)
2003 gdb_assert (WIFSTOPPED (status)
2004 && WSTOPSIG (status) == SIGSTOP);
2007 if (!in_thread_list (inferior_ptid))
2009 inferior_ptid = BUILD_LWP (GET_PID (inferior_ptid),
2010 GET_PID (inferior_ptid));
2011 add_thread (inferior_ptid);
2014 add_thread (lp->ptid);
2015 printf_unfiltered (_("[New %s]\n"),
2016 target_pid_to_str (lp->ptid));
2019 /* Handle GNU/Linux's extended waitstatus for trace events. */
2020 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
2022 if (debug_linux_nat)
2023 fprintf_unfiltered (gdb_stdlog,
2024 "LLW: Handling extended status 0x%06x\n",
2026 if (linux_nat_handle_extended (lp, status))
2033 /* Check if the thread has exited. */
2034 if ((WIFEXITED (status) || WIFSIGNALED (status)) && num_lwps > 1)
2036 /* If this is the main thread, we must stop all threads and
2037 verify if they are still alive. This is because in the nptl
2038 thread model, there is no signal issued for exiting LWPs
2039 other than the main thread. We only get the main thread
2040 exit signal once all child threads have already exited.
2041 If we stop all the threads and use the stop_wait_callback
2042 to check if they have exited we can determine whether this
2043 signal should be ignored or whether it means the end of the
2044 debugged application, regardless of which threading model
2046 if (GET_PID (lp->ptid) == GET_LWP (lp->ptid))
2049 iterate_over_lwps (stop_and_resume_callback, NULL);
2052 if (debug_linux_nat)
2053 fprintf_unfiltered (gdb_stdlog,
2054 "LLW: %s exited.\n",
2055 target_pid_to_str (lp->ptid));
2059 /* If there is at least one more LWP, then the exit signal
2060 was not the end of the debugged application and should be
2064 /* Make sure there is at least one thread running. */
2065 gdb_assert (iterate_over_lwps (running_callback, NULL));
2067 /* Discard the event. */
2073 /* Check if the current LWP has previously exited. In the nptl
2074 thread model, LWPs other than the main thread do not issue
2075 signals when they exit so we must check whenever the thread
2076 has stopped. A similar check is made in stop_wait_callback(). */
2077 if (num_lwps > 1 && !linux_nat_thread_alive (lp->ptid))
2079 if (debug_linux_nat)
2080 fprintf_unfiltered (gdb_stdlog,
2081 "LLW: %s exited.\n",
2082 target_pid_to_str (lp->ptid));
2086 /* Make sure there is at least one thread running. */
2087 gdb_assert (iterate_over_lwps (running_callback, NULL));
2089 /* Discard the event. */
2094 /* Make sure we don't report a SIGSTOP that we sent
2095 ourselves in an attempt to stop an LWP. */
2097 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP)
2099 if (debug_linux_nat)
2100 fprintf_unfiltered (gdb_stdlog,
2101 "LLW: Delayed SIGSTOP caught for %s.\n",
2102 target_pid_to_str (lp->ptid));
2104 /* This is a delayed SIGSTOP. */
2107 registers_changed ();
2108 linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)),
2109 lp->step, TARGET_SIGNAL_0);
2110 if (debug_linux_nat)
2111 fprintf_unfiltered (gdb_stdlog,
2112 "LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
2114 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2115 target_pid_to_str (lp->ptid));
2118 gdb_assert (lp->resumed);
2120 /* Discard the event. */
2130 /* Alternate between checking cloned and uncloned processes. */
2131 options ^= __WCLONE;
2133 /* And suspend every time we have checked both. */
2134 if (options & __WCLONE)
2135 sigsuspend (&suspend_mask);
2138 /* We shouldn't end up here unless we want to try again. */
2139 gdb_assert (status == 0);
2142 clear_sigio_trap ();
2143 clear_sigint_trap ();
2147 /* Don't report signals that GDB isn't interested in, such as
2148 signals that are neither printed nor stopped upon. Stopping all
2149 threads can be a bit time-consuming so if we want decent
2150 performance with heavily multi-threaded programs, especially when
2151 they're using a high frequency timer, we'd better avoid it if we
2154 if (WIFSTOPPED (status))
2156 int signo = target_signal_from_host (WSTOPSIG (status));
2158 /* If we get a signal while single-stepping, we may need special
2159 care, e.g. to skip the signal handler. Defer to common code. */
2161 && signal_stop_state (signo) == 0
2162 && signal_print_state (signo) == 0
2163 && signal_pass_state (signo) == 1)
2165 /* FIMXE: kettenis/2001-06-06: Should we resume all threads
2166 here? It is not clear we should. GDB may not expect
2167 other threads to run. On the other hand, not resuming
2168 newly attached threads may cause an unwanted delay in
2169 getting them running. */
2170 registers_changed ();
2171 linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)),
2173 if (debug_linux_nat)
2174 fprintf_unfiltered (gdb_stdlog,
2175 "LLW: %s %s, %s (preempt 'handle')\n",
2177 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2178 target_pid_to_str (lp->ptid),
2179 signo ? strsignal (signo) : "0");
2185 if (signo == TARGET_SIGNAL_INT && signal_pass_state (signo) == 0)
2187 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
2188 forwarded to the entire process group, that is, all LWP's
2189 will receive it. Since we only want to report it once,
2190 we try to flush it from all LWPs except this one. */
2191 sigaddset (&flush_mask, SIGINT);
2195 /* This LWP is stopped now. */
2198 if (debug_linux_nat)
2199 fprintf_unfiltered (gdb_stdlog, "LLW: Candidate event %s in %s.\n",
2200 status_to_str (status), target_pid_to_str (lp->ptid));
2202 /* Now stop all other LWP's ... */
2203 iterate_over_lwps (stop_callback, NULL);
2205 /* ... and wait until all of them have reported back that they're no
2207 iterate_over_lwps (stop_wait_callback, &flush_mask);
2208 iterate_over_lwps (flush_callback, &flush_mask);
2210 /* If we're not waiting for a specific LWP, choose an event LWP from
2211 among those that have had events. Giving equal priority to all
2212 LWPs that have had events helps prevent starvation. */
2214 select_event_lwp (&lp, &status);
2216 /* Now that we've selected our final event LWP, cancel any
2217 breakpoints in other LWPs that have hit a GDB breakpoint. See
2218 the comment in cancel_breakpoints_callback to find out why. */
2219 iterate_over_lwps (cancel_breakpoints_callback, lp);
2221 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP)
2223 trap_ptid = lp->ptid;
2224 if (debug_linux_nat)
2225 fprintf_unfiltered (gdb_stdlog,
2226 "LLW: trap_ptid is %s.\n",
2227 target_pid_to_str (trap_ptid));
2230 trap_ptid = null_ptid;
2232 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
2234 *ourstatus = lp->waitstatus;
2235 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
2238 store_waitstatus (ourstatus, status);
2244 kill_callback (struct lwp_info *lp, void *data)
2247 ptrace (PTRACE_KILL, GET_LWP (lp->ptid), 0, 0);
2248 if (debug_linux_nat)
2249 fprintf_unfiltered (gdb_stdlog,
2250 "KC: PTRACE_KILL %s, 0, 0 (%s)\n",
2251 target_pid_to_str (lp->ptid),
2252 errno ? safe_strerror (errno) : "OK");
2258 kill_wait_callback (struct lwp_info *lp, void *data)
2262 /* We must make sure that there are no pending events (delayed
2263 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
2264 program doesn't interfere with any following debugging session. */
2266 /* For cloned processes we must check both with __WCLONE and
2267 without, since the exit status of a cloned process isn't reported
2273 pid = my_waitpid (GET_LWP (lp->ptid), NULL, __WCLONE);
2274 if (pid != (pid_t) -1 && debug_linux_nat)
2276 fprintf_unfiltered (gdb_stdlog,
2277 "KWC: wait %s received unknown.\n",
2278 target_pid_to_str (lp->ptid));
2281 while (pid == GET_LWP (lp->ptid));
2283 gdb_assert (pid == -1 && errno == ECHILD);
2288 pid = my_waitpid (GET_LWP (lp->ptid), NULL, 0);
2289 if (pid != (pid_t) -1 && debug_linux_nat)
2291 fprintf_unfiltered (gdb_stdlog,
2292 "KWC: wait %s received unk.\n",
2293 target_pid_to_str (lp->ptid));
2296 while (pid == GET_LWP (lp->ptid));
2298 gdb_assert (pid == -1 && errno == ECHILD);
2303 linux_nat_kill (void)
2305 struct target_waitstatus last;
2309 /* If we're stopped while forking and we haven't followed yet,
2310 kill the other task. We need to do this first because the
2311 parent will be sleeping if this is a vfork. */
2313 get_last_target_status (&last_ptid, &last);
2315 if (last.kind == TARGET_WAITKIND_FORKED
2316 || last.kind == TARGET_WAITKIND_VFORKED)
2318 ptrace (PT_KILL, last.value.related_pid, 0, 0);
2322 if (forks_exist_p ())
2323 linux_fork_killall ();
2326 /* Kill all LWP's ... */
2327 iterate_over_lwps (kill_callback, NULL);
2329 /* ... and wait until we've flushed all events. */
2330 iterate_over_lwps (kill_wait_callback, NULL);
2333 target_mourn_inferior ();
2337 linux_nat_mourn_inferior (void)
2339 trap_ptid = null_ptid;
2341 /* Destroy LWP info; it's no longer valid. */
2344 /* Restore the original signal mask. */
2345 sigprocmask (SIG_SETMASK, &normal_mask, NULL);
2346 sigemptyset (&blocked_mask);
2348 if (! forks_exist_p ())
2349 /* Normal case, no other forks available. */
2350 linux_ops->to_mourn_inferior ();
2352 /* Multi-fork case. The current inferior_ptid has exited, but
2353 there are other viable forks to debug. Delete the exiting
2354 one and context-switch to the first available. */
2355 linux_fork_mourn_inferior ();
2359 linux_nat_xfer_partial (struct target_ops *ops, enum target_object object,
2360 const char *annex, gdb_byte *readbuf,
2361 const gdb_byte *writebuf,
2362 ULONGEST offset, LONGEST len)
2364 struct cleanup *old_chain = save_inferior_ptid ();
2367 if (is_lwp (inferior_ptid))
2368 inferior_ptid = pid_to_ptid (GET_LWP (inferior_ptid));
2370 xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf,
2373 do_cleanups (old_chain);
2378 linux_nat_thread_alive (ptid_t ptid)
2380 gdb_assert (is_lwp (ptid));
2383 ptrace (PTRACE_PEEKUSER, GET_LWP (ptid), 0, 0);
2384 if (debug_linux_nat)
2385 fprintf_unfiltered (gdb_stdlog,
2386 "LLTA: PTRACE_PEEKUSER %s, 0, 0 (%s)\n",
2387 target_pid_to_str (ptid),
2388 errno ? safe_strerror (errno) : "OK");
2390 /* Not every Linux target implements PTRACE_PEEKUSER.
2391 But we can handle that case gracefully since ptrace
2392 will first do a lookup for the process based upon the
2393 passed-in pid. If that fails we will get either -ESRCH
2394 or -EPERM, otherwise the child exists and is alive. */
2395 if (errno == ESRCH || errno == EPERM)
2402 linux_nat_pid_to_str (ptid_t ptid)
2404 static char buf[64];
2406 if (lwp_list && lwp_list->next && is_lwp (ptid))
2408 snprintf (buf, sizeof (buf), "LWP %ld", GET_LWP (ptid));
2412 return normal_pid_to_str (ptid);
2416 sigchld_handler (int signo)
2418 /* Do nothing. The only reason for this handler is that it allows
2419 us to use sigsuspend in linux_nat_wait above to wait for the
2420 arrival of a SIGCHLD. */
2423 /* Accepts an integer PID; Returns a string representing a file that
2424 can be opened to get the symbols for the child process. */
2427 child_pid_to_exec_file (int pid)
2429 char *name1, *name2;
2431 name1 = xmalloc (MAXPATHLEN);
2432 name2 = xmalloc (MAXPATHLEN);
2433 make_cleanup (xfree, name1);
2434 make_cleanup (xfree, name2);
2435 memset (name2, 0, MAXPATHLEN);
2437 sprintf (name1, "/proc/%d/exe", pid);
2438 if (readlink (name1, name2, MAXPATHLEN) > 0)
2444 /* Service function for corefiles and info proc. */
2447 read_mapping (FILE *mapfile,
2452 char *device, long long *inode, char *filename)
2454 int ret = fscanf (mapfile, "%llx-%llx %s %llx %s %llx",
2455 addr, endaddr, permissions, offset, device, inode);
2458 if (ret > 0 && ret != EOF)
2460 /* Eat everything up to EOL for the filename. This will prevent
2461 weird filenames (such as one with embedded whitespace) from
2462 confusing this code. It also makes this code more robust in
2463 respect to annotations the kernel may add after the filename.
2465 Note the filename is used for informational purposes
2467 ret += fscanf (mapfile, "%[^\n]\n", filename);
2470 return (ret != 0 && ret != EOF);
2473 /* Fills the "to_find_memory_regions" target vector. Lists the memory
2474 regions in the inferior for a corefile. */
2477 linux_nat_find_memory_regions (int (*func) (CORE_ADDR,
2479 int, int, int, void *), void *obfd)
2481 long long pid = PIDGET (inferior_ptid);
2482 char mapsfilename[MAXPATHLEN];
2484 long long addr, endaddr, size, offset, inode;
2485 char permissions[8], device[8], filename[MAXPATHLEN];
2486 int read, write, exec;
2489 /* Compose the filename for the /proc memory map, and open it. */
2490 sprintf (mapsfilename, "/proc/%lld/maps", pid);
2491 if ((mapsfile = fopen (mapsfilename, "r")) == NULL)
2492 error (_("Could not open %s."), mapsfilename);
2495 fprintf_filtered (gdb_stdout,
2496 "Reading memory regions from %s\n", mapsfilename);
2498 /* Now iterate until end-of-file. */
2499 while (read_mapping (mapsfile, &addr, &endaddr, &permissions[0],
2500 &offset, &device[0], &inode, &filename[0]))
2502 size = endaddr - addr;
2504 /* Get the segment's permissions. */
2505 read = (strchr (permissions, 'r') != 0);
2506 write = (strchr (permissions, 'w') != 0);
2507 exec = (strchr (permissions, 'x') != 0);
2511 fprintf_filtered (gdb_stdout,
2512 "Save segment, %lld bytes at 0x%s (%c%c%c)",
2513 size, paddr_nz (addr),
2515 write ? 'w' : ' ', exec ? 'x' : ' ');
2516 if (filename && filename[0])
2517 fprintf_filtered (gdb_stdout, " for %s", filename);
2518 fprintf_filtered (gdb_stdout, "\n");
2521 /* Invoke the callback function to create the corefile
2523 func (addr, size, read, write, exec, obfd);
2529 /* Records the thread's register state for the corefile note
2533 linux_nat_do_thread_registers (bfd *obfd, ptid_t ptid,
2534 char *note_data, int *note_size)
2536 gdb_gregset_t gregs;
2537 gdb_fpregset_t fpregs;
2538 #ifdef FILL_FPXREGSET
2539 gdb_fpxregset_t fpxregs;
2541 unsigned long lwp = ptid_get_lwp (ptid);
2542 struct gdbarch *gdbarch = current_gdbarch;
2543 const struct regset *regset;
2544 int core_regset_p, record_reg_p;
2546 core_regset_p = gdbarch_regset_from_core_section_p (gdbarch);
2550 regset = gdbarch_regset_from_core_section (gdbarch, ".reg",
2553 regset->collect_regset (regset, current_regcache, -1,
2554 &gregs, sizeof (gregs));
2559 fill_gregset (&gregs, -1);
2562 note_data = (char *) elfcore_write_prstatus (obfd,
2566 stop_signal, &gregs);
2571 regset = gdbarch_regset_from_core_section (gdbarch, ".reg2",
2574 regset->collect_regset (regset, current_regcache, -1,
2575 &fpregs, sizeof (fpregs));
2580 fill_fpregset (&fpregs, -1);
2583 note_data = (char *) elfcore_write_prfpreg (obfd,
2586 &fpregs, sizeof (fpregs));
2588 #ifdef FILL_FPXREGSET
2592 regset = gdbarch_regset_from_core_section (gdbarch, ".reg-xfp",
2595 regset->collect_regset (regset, current_regcache, -1,
2596 &fpxregs, sizeof (fpxregs));
2601 fill_fpxregset (&fpxregs, -1);
2604 note_data = (char *) elfcore_write_prxfpreg (obfd,
2607 &fpxregs, sizeof (fpxregs));
2612 struct linux_nat_corefile_thread_data
2620 /* Called by gdbthread.c once per thread. Records the thread's
2621 register state for the corefile note section. */
2624 linux_nat_corefile_thread_callback (struct lwp_info *ti, void *data)
2626 struct linux_nat_corefile_thread_data *args = data;
2627 ptid_t saved_ptid = inferior_ptid;
2629 inferior_ptid = ti->ptid;
2630 registers_changed ();
2631 target_fetch_registers (-1); /* FIXME should not be necessary;
2632 fill_gregset should do it automatically. */
2633 args->note_data = linux_nat_do_thread_registers (args->obfd,
2638 inferior_ptid = saved_ptid;
2639 registers_changed ();
2640 target_fetch_registers (-1); /* FIXME should not be necessary;
2641 fill_gregset should do it automatically. */
2645 /* Records the register state for the corefile note section. */
2648 linux_nat_do_registers (bfd *obfd, ptid_t ptid,
2649 char *note_data, int *note_size)
2651 registers_changed ();
2652 target_fetch_registers (-1); /* FIXME should not be necessary;
2653 fill_gregset should do it automatically. */
2654 return linux_nat_do_thread_registers (obfd,
2655 ptid_build (ptid_get_pid (inferior_ptid),
2656 ptid_get_pid (inferior_ptid),
2658 note_data, note_size);
2662 /* Fills the "to_make_corefile_note" target vector. Builds the note
2663 section for a corefile, and returns it in a malloc buffer. */
2666 linux_nat_make_corefile_notes (bfd *obfd, int *note_size)
2668 struct linux_nat_corefile_thread_data thread_args;
2669 struct cleanup *old_chain;
2670 char fname[16] = { '\0' };
2671 char psargs[80] = { '\0' };
2672 char *note_data = NULL;
2673 ptid_t current_ptid = inferior_ptid;
2677 if (get_exec_file (0))
2679 strncpy (fname, strrchr (get_exec_file (0), '/') + 1, sizeof (fname));
2680 strncpy (psargs, get_exec_file (0), sizeof (psargs));
2681 if (get_inferior_args ())
2683 strncat (psargs, " ", sizeof (psargs) - strlen (psargs));
2684 strncat (psargs, get_inferior_args (),
2685 sizeof (psargs) - strlen (psargs));
2687 note_data = (char *) elfcore_write_prpsinfo (obfd,
2689 note_size, fname, psargs);
2692 /* Dump information for threads. */
2693 thread_args.obfd = obfd;
2694 thread_args.note_data = note_data;
2695 thread_args.note_size = note_size;
2696 thread_args.num_notes = 0;
2697 iterate_over_lwps (linux_nat_corefile_thread_callback, &thread_args);
2698 if (thread_args.num_notes == 0)
2700 /* iterate_over_threads didn't come up with any threads; just
2701 use inferior_ptid. */
2702 note_data = linux_nat_do_registers (obfd, inferior_ptid,
2703 note_data, note_size);
2707 note_data = thread_args.note_data;
2710 auxv_len = target_auxv_read (¤t_target, &auxv);
2713 note_data = elfcore_write_note (obfd, note_data, note_size,
2714 "CORE", NT_AUXV, auxv, auxv_len);
2718 make_cleanup (xfree, note_data);
2722 /* Implement the "info proc" command. */
2725 linux_nat_info_proc_cmd (char *args, int from_tty)
2727 long long pid = PIDGET (inferior_ptid);
2730 char buffer[MAXPATHLEN];
2731 char fname1[MAXPATHLEN], fname2[MAXPATHLEN];
2744 /* Break up 'args' into an argv array. */
2745 if ((argv = buildargv (args)) == NULL)
2748 make_cleanup_freeargv (argv);
2750 while (argv != NULL && *argv != NULL)
2752 if (isdigit (argv[0][0]))
2754 pid = strtoul (argv[0], NULL, 10);
2756 else if (strncmp (argv[0], "mappings", strlen (argv[0])) == 0)
2760 else if (strcmp (argv[0], "status") == 0)
2764 else if (strcmp (argv[0], "stat") == 0)
2768 else if (strcmp (argv[0], "cmd") == 0)
2772 else if (strncmp (argv[0], "exe", strlen (argv[0])) == 0)
2776 else if (strcmp (argv[0], "cwd") == 0)
2780 else if (strncmp (argv[0], "all", strlen (argv[0])) == 0)
2786 /* [...] (future options here) */
2791 error (_("No current process: you must name one."));
2793 sprintf (fname1, "/proc/%lld", pid);
2794 if (stat (fname1, &dummy) != 0)
2795 error (_("No /proc directory: '%s'"), fname1);
2797 printf_filtered (_("process %lld\n"), pid);
2798 if (cmdline_f || all)
2800 sprintf (fname1, "/proc/%lld/cmdline", pid);
2801 if ((procfile = fopen (fname1, "r")) > 0)
2803 fgets (buffer, sizeof (buffer), procfile);
2804 printf_filtered ("cmdline = '%s'\n", buffer);
2808 warning (_("unable to open /proc file '%s'"), fname1);
2812 sprintf (fname1, "/proc/%lld/cwd", pid);
2813 memset (fname2, 0, sizeof (fname2));
2814 if (readlink (fname1, fname2, sizeof (fname2)) > 0)
2815 printf_filtered ("cwd = '%s'\n", fname2);
2817 warning (_("unable to read link '%s'"), fname1);
2821 sprintf (fname1, "/proc/%lld/exe", pid);
2822 memset (fname2, 0, sizeof (fname2));
2823 if (readlink (fname1, fname2, sizeof (fname2)) > 0)
2824 printf_filtered ("exe = '%s'\n", fname2);
2826 warning (_("unable to read link '%s'"), fname1);
2828 if (mappings_f || all)
2830 sprintf (fname1, "/proc/%lld/maps", pid);
2831 if ((procfile = fopen (fname1, "r")) > 0)
2833 long long addr, endaddr, size, offset, inode;
2834 char permissions[8], device[8], filename[MAXPATHLEN];
2836 printf_filtered (_("Mapped address spaces:\n\n"));
2837 if (TARGET_ADDR_BIT == 32)
2839 printf_filtered ("\t%10s %10s %10s %10s %7s\n",
2842 " Size", " Offset", "objfile");
2846 printf_filtered (" %18s %18s %10s %10s %7s\n",
2849 " Size", " Offset", "objfile");
2852 while (read_mapping (procfile, &addr, &endaddr, &permissions[0],
2853 &offset, &device[0], &inode, &filename[0]))
2855 size = endaddr - addr;
2857 /* FIXME: carlton/2003-08-27: Maybe the printf_filtered
2858 calls here (and possibly above) should be abstracted
2859 out into their own functions? Andrew suggests using
2860 a generic local_address_string instead to print out
2861 the addresses; that makes sense to me, too. */
2863 if (TARGET_ADDR_BIT == 32)
2865 printf_filtered ("\t%#10lx %#10lx %#10x %#10x %7s\n",
2866 (unsigned long) addr, /* FIXME: pr_addr */
2867 (unsigned long) endaddr,
2869 (unsigned int) offset,
2870 filename[0] ? filename : "");
2874 printf_filtered (" %#18lx %#18lx %#10x %#10x %7s\n",
2875 (unsigned long) addr, /* FIXME: pr_addr */
2876 (unsigned long) endaddr,
2878 (unsigned int) offset,
2879 filename[0] ? filename : "");
2886 warning (_("unable to open /proc file '%s'"), fname1);
2888 if (status_f || all)
2890 sprintf (fname1, "/proc/%lld/status", pid);
2891 if ((procfile = fopen (fname1, "r")) > 0)
2893 while (fgets (buffer, sizeof (buffer), procfile) != NULL)
2894 puts_filtered (buffer);
2898 warning (_("unable to open /proc file '%s'"), fname1);
2902 sprintf (fname1, "/proc/%lld/stat", pid);
2903 if ((procfile = fopen (fname1, "r")) > 0)
2908 if (fscanf (procfile, "%d ", &itmp) > 0)
2909 printf_filtered (_("Process: %d\n"), itmp);
2910 if (fscanf (procfile, "%s ", &buffer[0]) > 0)
2911 printf_filtered (_("Exec file: %s\n"), buffer);
2912 if (fscanf (procfile, "%c ", &ctmp) > 0)
2913 printf_filtered (_("State: %c\n"), ctmp);
2914 if (fscanf (procfile, "%d ", &itmp) > 0)
2915 printf_filtered (_("Parent process: %d\n"), itmp);
2916 if (fscanf (procfile, "%d ", &itmp) > 0)
2917 printf_filtered (_("Process group: %d\n"), itmp);
2918 if (fscanf (procfile, "%d ", &itmp) > 0)
2919 printf_filtered (_("Session id: %d\n"), itmp);
2920 if (fscanf (procfile, "%d ", &itmp) > 0)
2921 printf_filtered (_("TTY: %d\n"), itmp);
2922 if (fscanf (procfile, "%d ", &itmp) > 0)
2923 printf_filtered (_("TTY owner process group: %d\n"), itmp);
2924 if (fscanf (procfile, "%u ", &itmp) > 0)
2925 printf_filtered (_("Flags: 0x%x\n"), itmp);
2926 if (fscanf (procfile, "%u ", &itmp) > 0)
2927 printf_filtered (_("Minor faults (no memory page): %u\n"),
2928 (unsigned int) itmp);
2929 if (fscanf (procfile, "%u ", &itmp) > 0)
2930 printf_filtered (_("Minor faults, children: %u\n"),
2931 (unsigned int) itmp);
2932 if (fscanf (procfile, "%u ", &itmp) > 0)
2933 printf_filtered (_("Major faults (memory page faults): %u\n"),
2934 (unsigned int) itmp);
2935 if (fscanf (procfile, "%u ", &itmp) > 0)
2936 printf_filtered (_("Major faults, children: %u\n"),
2937 (unsigned int) itmp);
2938 if (fscanf (procfile, "%d ", &itmp) > 0)
2939 printf_filtered ("utime: %d\n", itmp);
2940 if (fscanf (procfile, "%d ", &itmp) > 0)
2941 printf_filtered ("stime: %d\n", itmp);
2942 if (fscanf (procfile, "%d ", &itmp) > 0)
2943 printf_filtered ("utime, children: %d\n", itmp);
2944 if (fscanf (procfile, "%d ", &itmp) > 0)
2945 printf_filtered ("stime, children: %d\n", itmp);
2946 if (fscanf (procfile, "%d ", &itmp) > 0)
2947 printf_filtered (_("jiffies remaining in current time slice: %d\n"),
2949 if (fscanf (procfile, "%d ", &itmp) > 0)
2950 printf_filtered ("'nice' value: %d\n", itmp);
2951 if (fscanf (procfile, "%u ", &itmp) > 0)
2952 printf_filtered (_("jiffies until next timeout: %u\n"),
2953 (unsigned int) itmp);
2954 if (fscanf (procfile, "%u ", &itmp) > 0)
2955 printf_filtered ("jiffies until next SIGALRM: %u\n",
2956 (unsigned int) itmp);
2957 if (fscanf (procfile, "%d ", &itmp) > 0)
2958 printf_filtered (_("start time (jiffies since system boot): %d\n"),
2960 if (fscanf (procfile, "%u ", &itmp) > 0)
2961 printf_filtered (_("Virtual memory size: %u\n"),
2962 (unsigned int) itmp);
2963 if (fscanf (procfile, "%u ", &itmp) > 0)
2964 printf_filtered (_("Resident set size: %u\n"), (unsigned int) itmp);
2965 if (fscanf (procfile, "%u ", &itmp) > 0)
2966 printf_filtered ("rlim: %u\n", (unsigned int) itmp);
2967 if (fscanf (procfile, "%u ", &itmp) > 0)
2968 printf_filtered (_("Start of text: 0x%x\n"), itmp);
2969 if (fscanf (procfile, "%u ", &itmp) > 0)
2970 printf_filtered (_("End of text: 0x%x\n"), itmp);
2971 if (fscanf (procfile, "%u ", &itmp) > 0)
2972 printf_filtered (_("Start of stack: 0x%x\n"), itmp);
2973 #if 0 /* Don't know how architecture-dependent the rest is...
2974 Anyway the signal bitmap info is available from "status". */
2975 if (fscanf (procfile, "%u ", &itmp) > 0) /* FIXME arch? */
2976 printf_filtered (_("Kernel stack pointer: 0x%x\n"), itmp);
2977 if (fscanf (procfile, "%u ", &itmp) > 0) /* FIXME arch? */
2978 printf_filtered (_("Kernel instr pointer: 0x%x\n"), itmp);
2979 if (fscanf (procfile, "%d ", &itmp) > 0)
2980 printf_filtered (_("Pending signals bitmap: 0x%x\n"), itmp);
2981 if (fscanf (procfile, "%d ", &itmp) > 0)
2982 printf_filtered (_("Blocked signals bitmap: 0x%x\n"), itmp);
2983 if (fscanf (procfile, "%d ", &itmp) > 0)
2984 printf_filtered (_("Ignored signals bitmap: 0x%x\n"), itmp);
2985 if (fscanf (procfile, "%d ", &itmp) > 0)
2986 printf_filtered (_("Catched signals bitmap: 0x%x\n"), itmp);
2987 if (fscanf (procfile, "%u ", &itmp) > 0) /* FIXME arch? */
2988 printf_filtered (_("wchan (system call): 0x%x\n"), itmp);
2993 warning (_("unable to open /proc file '%s'"), fname1);
2997 /* Implement the to_xfer_partial interface for memory reads using the /proc
2998 filesystem. Because we can use a single read() call for /proc, this
2999 can be much more efficient than banging away at PTRACE_PEEKTEXT,
3000 but it doesn't support writes. */
3003 linux_proc_xfer_partial (struct target_ops *ops, enum target_object object,
3004 const char *annex, gdb_byte *readbuf,
3005 const gdb_byte *writebuf,
3006 ULONGEST offset, LONGEST len)
3012 if (object != TARGET_OBJECT_MEMORY || !readbuf)
3015 /* Don't bother for one word. */
3016 if (len < 3 * sizeof (long))
3019 /* We could keep this file open and cache it - possibly one per
3020 thread. That requires some juggling, but is even faster. */
3021 sprintf (filename, "/proc/%d/mem", PIDGET (inferior_ptid));
3022 fd = open (filename, O_RDONLY | O_LARGEFILE);
3026 /* If pread64 is available, use it. It's faster if the kernel
3027 supports it (only one syscall), and it's 64-bit safe even on
3028 32-bit platforms (for instance, SPARC debugging a SPARC64
3031 if (pread64 (fd, readbuf, len, offset) != len)
3033 if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len)
3043 /* Parse LINE as a signal set and add its set bits to SIGS. */
3046 add_line_to_sigset (const char *line, sigset_t *sigs)
3048 int len = strlen (line) - 1;
3052 if (line[len] != '\n')
3053 error (_("Could not parse signal set: %s"), line);
3061 if (*p >= '0' && *p <= '9')
3063 else if (*p >= 'a' && *p <= 'f')
3064 digit = *p - 'a' + 10;
3066 error (_("Could not parse signal set: %s"), line);
3071 sigaddset (sigs, signum + 1);
3073 sigaddset (sigs, signum + 2);
3075 sigaddset (sigs, signum + 3);
3077 sigaddset (sigs, signum + 4);
3083 /* Find process PID's pending signals from /proc/pid/status and set
3087 linux_proc_pending_signals (int pid, sigset_t *pending, sigset_t *blocked, sigset_t *ignored)
3090 char buffer[MAXPATHLEN], fname[MAXPATHLEN];
3093 sigemptyset (pending);
3094 sigemptyset (blocked);
3095 sigemptyset (ignored);
3096 sprintf (fname, "/proc/%d/status", pid);
3097 procfile = fopen (fname, "r");
3098 if (procfile == NULL)
3099 error (_("Could not open %s"), fname);
3101 while (fgets (buffer, MAXPATHLEN, procfile) != NULL)
3103 /* Normal queued signals are on the SigPnd line in the status
3104 file. However, 2.6 kernels also have a "shared" pending
3105 queue for delivering signals to a thread group, so check for
3108 Unfortunately some Red Hat kernels include the shared pending
3109 queue but not the ShdPnd status field. */
3111 if (strncmp (buffer, "SigPnd:\t", 8) == 0)
3112 add_line_to_sigset (buffer + 8, pending);
3113 else if (strncmp (buffer, "ShdPnd:\t", 8) == 0)
3114 add_line_to_sigset (buffer + 8, pending);
3115 else if (strncmp (buffer, "SigBlk:\t", 8) == 0)
3116 add_line_to_sigset (buffer + 8, blocked);
3117 else if (strncmp (buffer, "SigIgn:\t", 8) == 0)
3118 add_line_to_sigset (buffer + 8, ignored);
3125 linux_xfer_partial (struct target_ops *ops, enum target_object object,
3126 const char *annex, gdb_byte *readbuf,
3127 const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
3131 if (object == TARGET_OBJECT_AUXV)
3132 return procfs_xfer_auxv (ops, object, annex, readbuf, writebuf,
3135 xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf,
3140 return super_xfer_partial (ops, object, annex, readbuf, writebuf,
3144 #ifndef FETCH_INFERIOR_REGISTERS
3146 /* Return the address in the core dump or inferior of register
3150 linux_register_u_offset (int regno)
3152 /* FIXME drow/2005-09-04: The hardcoded use of register_addr should go
3153 away. This requires disentangling the various definitions of it
3154 (particularly alpha-nat.c's). */
3155 return register_addr (regno, 0);
3160 /* Create a prototype generic Linux target. The client can override
3161 it with local methods. */
3166 struct target_ops *t;
3168 #ifdef FETCH_INFERIOR_REGISTERS
3169 t = inf_ptrace_target ();
3171 t = inf_ptrace_trad_target (linux_register_u_offset);
3173 t->to_insert_fork_catchpoint = child_insert_fork_catchpoint;
3174 t->to_insert_vfork_catchpoint = child_insert_vfork_catchpoint;
3175 t->to_insert_exec_catchpoint = child_insert_exec_catchpoint;
3176 t->to_pid_to_exec_file = child_pid_to_exec_file;
3177 t->to_post_startup_inferior = linux_child_post_startup_inferior;
3178 t->to_post_attach = child_post_attach;
3179 t->to_follow_fork = child_follow_fork;
3180 t->to_find_memory_regions = linux_nat_find_memory_regions;
3181 t->to_make_corefile_notes = linux_nat_make_corefile_notes;
3183 super_xfer_partial = t->to_xfer_partial;
3184 t->to_xfer_partial = linux_xfer_partial;
3190 linux_nat_add_target (struct target_ops *t)
3192 extern void thread_db_init (struct target_ops *);
3194 /* Save the provided single-threaded target. We save this in a separate
3195 variable because another target we've inherited from (e.g. inf-ptrace)
3196 may have saved a pointer to T; we want to use it for the final
3197 process stratum target. */
3198 linux_ops_saved = *t;
3199 linux_ops = &linux_ops_saved;
3201 /* Override some methods for multithreading. */
3202 t->to_attach = linux_nat_attach;
3203 t->to_detach = linux_nat_detach;
3204 t->to_resume = linux_nat_resume;
3205 t->to_wait = linux_nat_wait;
3206 t->to_xfer_partial = linux_nat_xfer_partial;
3207 t->to_kill = linux_nat_kill;
3208 t->to_mourn_inferior = linux_nat_mourn_inferior;
3209 t->to_thread_alive = linux_nat_thread_alive;
3210 t->to_pid_to_str = linux_nat_pid_to_str;
3211 t->to_has_thread_control = tc_schedlock;
3213 /* We don't change the stratum; this target will sit at
3214 process_stratum and thread_db will set at thread_stratum. This
3215 is a little strange, since this is a multi-threaded-capable
3216 target, but we want to be on the stack below thread_db, and we
3217 also want to be used for single-threaded processes. */
3221 /* TODO: Eliminate this and have libthread_db use
3222 find_target_beneath. */
3227 _initialize_linux_nat (void)
3229 struct sigaction action;
3231 add_info ("proc", linux_nat_info_proc_cmd, _("\
3232 Show /proc process information about any running process.\n\
3233 Specify any process id, or use the program being debugged by default.\n\
3234 Specify any of the following keywords for detailed info:\n\
3235 mappings -- list of mapped memory regions.\n\
3236 stat -- list a bunch of random process info.\n\
3237 status -- list a different bunch of random process info.\n\
3238 all -- list all available /proc info."));
3240 /* Save the original signal mask. */
3241 sigprocmask (SIG_SETMASK, NULL, &normal_mask);
3243 action.sa_handler = sigchld_handler;
3244 sigemptyset (&action.sa_mask);
3245 action.sa_flags = SA_RESTART;
3246 sigaction (SIGCHLD, &action, NULL);
3248 /* Make sure we don't block SIGCHLD during a sigsuspend. */
3249 sigprocmask (SIG_SETMASK, NULL, &suspend_mask);
3250 sigdelset (&suspend_mask, SIGCHLD);
3252 sigemptyset (&blocked_mask);
3254 add_setshow_zinteger_cmd ("lin-lwp", no_class, &debug_linux_nat, _("\
3255 Set debugging of GNU/Linux lwp module."), _("\
3256 Show debugging of GNU/Linux lwp module."), _("\
3257 Enables printf debugging output."),
3259 show_debug_linux_nat,
3260 &setdebuglist, &showdebuglist);
3264 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
3265 the GNU/Linux Threads library and therefore doesn't really belong
3268 /* Read variable NAME in the target and return its value if found.
3269 Otherwise return zero. It is assumed that the type of the variable
3273 get_signo (const char *name)
3275 struct minimal_symbol *ms;
3278 ms = lookup_minimal_symbol (name, NULL, NULL);
3282 if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo,
3283 sizeof (signo)) != 0)
3289 /* Return the set of signals used by the threads library in *SET. */
3292 lin_thread_get_thread_signals (sigset_t *set)
3294 struct sigaction action;
3295 int restart, cancel;
3299 restart = get_signo ("__pthread_sig_restart");
3300 cancel = get_signo ("__pthread_sig_cancel");
3302 /* LinuxThreads normally uses the first two RT signals, but in some legacy
3303 cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
3304 not provide any way for the debugger to query the signal numbers -
3305 fortunately they don't change! */
3308 restart = __SIGRTMIN;
3311 cancel = __SIGRTMIN + 1;
3313 sigaddset (set, restart);
3314 sigaddset (set, cancel);
3316 /* The GNU/Linux Threads library makes terminating threads send a
3317 special "cancel" signal instead of SIGCHLD. Make sure we catch
3318 those (to prevent them from terminating GDB itself, which is
3319 likely to be their default action) and treat them the same way as
3322 action.sa_handler = sigchld_handler;
3323 sigemptyset (&action.sa_mask);
3324 action.sa_flags = SA_RESTART;
3325 sigaction (cancel, &action, NULL);
3327 /* We block the "cancel" signal throughout this code ... */
3328 sigaddset (&blocked_mask, cancel);
3329 sigprocmask (SIG_BLOCK, &blocked_mask, NULL);
3331 /* ... except during a sigsuspend. */
3332 sigdelset (&suspend_mask, cancel);