1 /* Low level interface to ptrace, for the remote server for GDB.
2 Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
3 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #include "linux-low.h"
25 #include <sys/param.h>
26 #include <sys/ptrace.h>
28 #include <sys/ioctl.h>
34 #include <sys/syscall.h>
38 #include <sys/types.h>
41 #ifndef PTRACE_GETSIGINFO
42 # define PTRACE_GETSIGINFO 0x4202
43 # define PTRACE_SETSIGINFO 0x4203
50 /* If the system headers did not provide the constants, hard-code the normal
52 #ifndef PTRACE_EVENT_FORK
54 #define PTRACE_SETOPTIONS 0x4200
55 #define PTRACE_GETEVENTMSG 0x4201
57 /* options set using PTRACE_SETOPTIONS */
58 #define PTRACE_O_TRACESYSGOOD 0x00000001
59 #define PTRACE_O_TRACEFORK 0x00000002
60 #define PTRACE_O_TRACEVFORK 0x00000004
61 #define PTRACE_O_TRACECLONE 0x00000008
62 #define PTRACE_O_TRACEEXEC 0x00000010
63 #define PTRACE_O_TRACEVFORKDONE 0x00000020
64 #define PTRACE_O_TRACEEXIT 0x00000040
66 /* Wait extended result codes for the above trace options. */
67 #define PTRACE_EVENT_FORK 1
68 #define PTRACE_EVENT_VFORK 2
69 #define PTRACE_EVENT_CLONE 3
70 #define PTRACE_EVENT_EXEC 4
71 #define PTRACE_EVENT_VFORK_DONE 5
72 #define PTRACE_EVENT_EXIT 6
74 #endif /* PTRACE_EVENT_FORK */
76 /* We can't always assume that this flag is available, but all systems
77 with the ptrace event handlers also have __WALL, so it's safe to use
80 #define __WALL 0x40000000 /* Wait for any child. */
84 #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
89 /* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
90 representation of the thread ID.
92 ``all_lwps'' is keyed by the process ID - which on Linux is (presently)
93 the same as the LWP ID. */
95 struct inferior_list all_lwps;
97 /* A list of all unknown processes which receive stop signals. Some other
98 process will presumably claim each of these as forked children
101 struct inferior_list stopped_pids;
103 /* FIXME this is a bit of a hack, and could be removed. */
104 int stopping_threads;
106 /* FIXME make into a target method? */
107 int using_threads = 1;
108 static int thread_db_active;
110 static int must_set_ptrace_flags;
112 /* This flag is true iff we've just created or attached to a new inferior
113 but it has not stopped yet. As soon as it does, we need to call the
114 low target's arch_setup callback. */
115 static int new_inferior;
117 static void linux_resume_one_lwp (struct inferior_list_entry *entry,
118 int step, int signal, siginfo_t *info);
119 static void linux_resume (struct thread_resume *resume_info, size_t n);
120 static void stop_all_lwps (void);
121 static int linux_wait_for_event (struct thread_info *child);
122 static int check_removed_breakpoint (struct lwp_info *event_child);
123 static void *add_lwp (unsigned long pid);
124 static int my_waitpid (int pid, int *status, int flags);
125 static int linux_stopped_by_watchpoint (void);
127 struct pending_signals
131 struct pending_signals *prev;
134 #define PTRACE_ARG3_TYPE long
135 #define PTRACE_XFER_TYPE long
137 #ifdef HAVE_LINUX_REGSETS
138 static char *disabled_regsets;
139 static int num_regsets;
142 #define pid_of(proc) ((proc)->head.id)
144 /* FIXME: Delete eventually. */
145 #define inferior_pid (pid_of (get_thread_lwp (current_inferior)))
148 handle_extended_wait (struct lwp_info *event_child, int wstat)
150 int event = wstat >> 16;
151 struct lwp_info *new_lwp;
153 if (event == PTRACE_EVENT_CLONE)
155 unsigned long new_pid;
156 int ret, status = W_STOPCODE (SIGSTOP);
158 ptrace (PTRACE_GETEVENTMSG, inferior_pid, 0, &new_pid);
160 /* If we haven't already seen the new PID stop, wait for it now. */
161 if (! pull_pid_from_list (&stopped_pids, new_pid))
163 /* The new child has a pending SIGSTOP. We can't affect it until it
164 hits the SIGSTOP, but we're already attached. */
166 ret = my_waitpid (new_pid, &status, __WALL);
169 perror_with_name ("waiting for new child");
170 else if (ret != new_pid)
171 warning ("wait returned unexpected PID %d", ret);
172 else if (!WIFSTOPPED (status))
173 warning ("wait returned unexpected status 0x%x", status);
176 ptrace (PTRACE_SETOPTIONS, new_pid, 0, PTRACE_O_TRACECLONE);
178 new_lwp = (struct lwp_info *) add_lwp (new_pid);
179 add_thread (new_pid, new_lwp, new_pid);
180 new_thread_notify (thread_id_to_gdb_id (new_lwp->lwpid));
182 /* Normally we will get the pending SIGSTOP. But in some cases
183 we might get another signal delivered to the group first.
184 If we do get another signal, be sure not to lose it. */
185 if (WSTOPSIG (status) == SIGSTOP)
187 if (stopping_threads)
188 new_lwp->stopped = 1;
190 ptrace (PTRACE_CONT, new_pid, 0, 0);
194 new_lwp->stop_expected = 1;
195 if (stopping_threads)
197 new_lwp->stopped = 1;
198 new_lwp->status_pending_p = 1;
199 new_lwp->status_pending = status;
202 /* Pass the signal on. This is what GDB does - except
203 shouldn't we really report it instead? */
204 ptrace (PTRACE_CONT, new_pid, 0, WSTOPSIG (status));
207 /* Always resume the current thread. If we are stopping
208 threads, it will have a pending SIGSTOP; we may as well
210 linux_resume_one_lwp (&event_child->head,
211 event_child->stepping, 0, NULL);
215 /* This function should only be called if the process got a SIGTRAP.
216 The SIGTRAP could mean several things.
218 On i386, where decr_pc_after_break is non-zero:
219 If we were single-stepping this process using PTRACE_SINGLESTEP,
220 we will get only the one SIGTRAP (even if the instruction we
221 stepped over was a breakpoint). The value of $eip will be the
223 If we continue the process using PTRACE_CONT, we will get a
224 SIGTRAP when we hit a breakpoint. The value of $eip will be
225 the instruction after the breakpoint (i.e. needs to be
226 decremented). If we report the SIGTRAP to GDB, we must also
227 report the undecremented PC. If we cancel the SIGTRAP, we
228 must resume at the decremented PC.
230 (Presumably, not yet tested) On a non-decr_pc_after_break machine
231 with hardware or kernel single-step:
232 If we single-step over a breakpoint instruction, our PC will
233 point at the following instruction. If we continue and hit a
234 breakpoint instruction, our PC will point at the breakpoint
240 CORE_ADDR stop_pc = (*the_low_target.get_pc) ();
242 if (get_thread_lwp (current_inferior)->stepping)
245 return stop_pc - the_low_target.decr_pc_after_break;
249 add_lwp (unsigned long pid)
251 struct lwp_info *lwp;
253 lwp = (struct lwp_info *) xmalloc (sizeof (*lwp));
254 memset (lwp, 0, sizeof (*lwp));
259 add_inferior_to_list (&all_lwps, &lwp->head);
264 /* Start an inferior process and returns its pid.
265 ALLARGS is a vector of program-name and args. */
268 linux_create_inferior (char *program, char **allargs)
273 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
279 perror_with_name ("fork");
283 ptrace (PTRACE_TRACEME, 0, 0, 0);
285 signal (__SIGRTMIN + 1, SIG_DFL);
289 execv (program, allargs);
291 execvp (program, allargs);
293 fprintf (stderr, "Cannot exec %s: %s.\n", program,
299 new_lwp = add_lwp (pid);
300 add_thread (pid, new_lwp, pid);
301 must_set_ptrace_flags = 1;
307 /* Attach to an inferior process. */
310 linux_attach_lwp (unsigned long pid)
312 struct lwp_info *new_lwp;
314 if (ptrace (PTRACE_ATTACH, pid, 0, 0) != 0)
316 if (all_threads.head != NULL)
318 /* If we fail to attach to an LWP, just warn. */
319 fprintf (stderr, "Cannot attach to lwp %ld: %s (%d)\n", pid,
320 strerror (errno), errno);
325 /* If we fail to attach to a process, report an error. */
326 error ("Cannot attach to process %ld: %s (%d)\n", pid,
327 strerror (errno), errno);
330 /* FIXME: This intermittently fails.
331 We need to wait for SIGSTOP first. */
332 ptrace (PTRACE_SETOPTIONS, pid, 0, PTRACE_O_TRACECLONE);
334 new_lwp = (struct lwp_info *) add_lwp (pid);
335 add_thread (pid, new_lwp, pid);
336 new_thread_notify (thread_id_to_gdb_id (new_lwp->lwpid));
338 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
341 There are several cases to consider here:
343 1) gdbserver has already attached to the process and is being notified
344 of a new thread that is being created.
345 In this case we should ignore that SIGSTOP and resume the process.
346 This is handled below by setting stop_expected = 1.
348 2) This is the first thread (the process thread), and we're attaching
349 to it via attach_inferior.
350 In this case we want the process thread to stop.
351 This is handled by having linux_attach clear stop_expected after
353 ??? If the process already has several threads we leave the other
356 3) GDB is connecting to gdbserver and is requesting an enumeration of all
358 In this case we want the thread to stop.
359 FIXME: This case is currently not properly handled.
360 We should wait for the SIGSTOP but don't. Things work apparently
361 because enough time passes between when we ptrace (ATTACH) and when
362 gdb makes the next ptrace call on the thread.
364 On the other hand, if we are currently trying to stop all threads, we
365 should treat the new thread as if we had sent it a SIGSTOP. This works
366 because we are guaranteed that the add_lwp call above added us to the
367 end of the list, and so the new thread has not yet reached
368 wait_for_sigstop (but will). */
369 if (! stopping_threads)
370 new_lwp->stop_expected = 1;
374 linux_attach (unsigned long pid)
376 struct lwp_info *lwp;
378 linux_attach_lwp (pid);
380 /* Don't ignore the initial SIGSTOP if we just attached to this process.
381 It will be collected by wait shortly. */
382 lwp = (struct lwp_info *) find_inferior_id (&all_lwps, pid);
383 lwp->stop_expected = 0;
390 /* Kill the inferior process. Make us have no inferior. */
393 linux_kill_one_lwp (struct inferior_list_entry *entry)
395 struct thread_info *thread = (struct thread_info *) entry;
396 struct lwp_info *lwp = get_thread_lwp (thread);
399 /* We avoid killing the first thread here, because of a Linux kernel (at
400 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
401 the children get a chance to be reaped, it will remain a zombie
403 if (entry == all_threads.head)
408 ptrace (PTRACE_KILL, pid_of (lwp), 0, 0);
410 /* Make sure it died. The loop is most likely unnecessary. */
411 wstat = linux_wait_for_event (thread);
412 } while (WIFSTOPPED (wstat));
418 struct thread_info *thread = (struct thread_info *) all_threads.head;
419 struct lwp_info *lwp;
425 for_each_inferior (&all_threads, linux_kill_one_lwp);
427 /* See the comment in linux_kill_one_lwp. We did not kill the first
428 thread in the list, so do so now. */
429 lwp = get_thread_lwp (thread);
432 ptrace (PTRACE_KILL, pid_of (lwp), 0, 0);
434 /* Make sure it died. The loop is most likely unnecessary. */
435 wstat = linux_wait_for_event (thread);
436 } while (WIFSTOPPED (wstat));
439 free (all_lwps.head);
440 all_lwps.head = all_lwps.tail = NULL;
444 linux_detach_one_lwp (struct inferior_list_entry *entry)
446 struct thread_info *thread = (struct thread_info *) entry;
447 struct lwp_info *lwp = get_thread_lwp (thread);
449 /* Make sure the process isn't stopped at a breakpoint that's
451 check_removed_breakpoint (lwp);
453 /* If this process is stopped but is expecting a SIGSTOP, then make
454 sure we take care of that now. This isn't absolutely guaranteed
455 to collect the SIGSTOP, but is fairly likely to. */
456 if (lwp->stop_expected)
458 /* Clear stop_expected, so that the SIGSTOP will be reported. */
459 lwp->stop_expected = 0;
461 linux_resume_one_lwp (&lwp->head, 0, 0, NULL);
462 linux_wait_for_event (thread);
465 /* Flush any pending changes to the process's registers. */
466 regcache_invalidate_one ((struct inferior_list_entry *)
467 get_lwp_thread (lwp));
469 /* Finally, let it resume. */
470 ptrace (PTRACE_DETACH, pid_of (lwp), 0, 0);
476 delete_all_breakpoints ();
477 for_each_inferior (&all_threads, linux_detach_one_lwp);
479 free (all_lwps.head);
480 all_lwps.head = all_lwps.tail = NULL;
487 extern unsigned long signal_pid;
491 ret = waitpid (signal_pid, &status, 0);
492 if (WIFEXITED (status) || WIFSIGNALED (status))
494 } while (ret != -1 || errno != ECHILD);
497 /* Return nonzero if the given thread is still alive. */
499 linux_thread_alive (unsigned long lwpid)
501 if (find_inferior_id (&all_threads, lwpid) != NULL)
507 /* Return nonzero if this process stopped at a breakpoint which
508 no longer appears to be inserted. Also adjust the PC
509 appropriately to resume where the breakpoint used to be. */
511 check_removed_breakpoint (struct lwp_info *event_child)
514 struct thread_info *saved_inferior;
516 if (event_child->pending_is_breakpoint == 0)
520 fprintf (stderr, "Checking for breakpoint in lwp %ld.\n",
523 saved_inferior = current_inferior;
524 current_inferior = get_lwp_thread (event_child);
526 stop_pc = get_stop_pc ();
528 /* If the PC has changed since we stopped, then we shouldn't do
529 anything. This happens if, for instance, GDB handled the
530 decr_pc_after_break subtraction itself. */
531 if (stop_pc != event_child->pending_stop_pc)
534 fprintf (stderr, "Ignoring, PC was changed. Old PC was 0x%08llx\n",
535 event_child->pending_stop_pc);
537 event_child->pending_is_breakpoint = 0;
538 current_inferior = saved_inferior;
542 /* If the breakpoint is still there, we will report hitting it. */
543 if ((*the_low_target.breakpoint_at) (stop_pc))
546 fprintf (stderr, "Ignoring, breakpoint is still present.\n");
547 current_inferior = saved_inferior;
552 fprintf (stderr, "Removed breakpoint.\n");
554 /* For decr_pc_after_break targets, here is where we perform the
555 decrement. We go immediately from this function to resuming,
556 and can not safely call get_stop_pc () again. */
557 if (the_low_target.set_pc != NULL)
558 (*the_low_target.set_pc) (stop_pc);
560 /* We consumed the pending SIGTRAP. */
561 event_child->pending_is_breakpoint = 0;
562 event_child->status_pending_p = 0;
563 event_child->status_pending = 0;
565 current_inferior = saved_inferior;
569 /* Return 1 if this lwp has an interesting status pending. This
570 function may silently resume an inferior lwp. */
572 status_pending_p (struct inferior_list_entry *entry, void *dummy)
574 struct lwp_info *lwp = (struct lwp_info *) entry;
576 if (lwp->status_pending_p)
577 if (check_removed_breakpoint (lwp))
579 /* This thread was stopped at a breakpoint, and the breakpoint
580 is now gone. We were told to continue (or step...) all threads,
581 so GDB isn't trying to single-step past this breakpoint.
582 So instead of reporting the old SIGTRAP, pretend we got to
583 the breakpoint just after it was removed instead of just
584 before; resume the process. */
585 linux_resume_one_lwp (&lwp->head, 0, 0, NULL);
589 return lwp->status_pending_p;
593 linux_wait_for_lwp (struct lwp_info **childp, int *wstatp)
596 int to_wait_for = -1;
599 to_wait_for = (*childp)->lwpid;
604 ret = waitpid (to_wait_for, wstatp, WNOHANG);
609 perror_with_name ("waitpid");
614 ret = waitpid (to_wait_for, wstatp, WNOHANG | __WCLONE);
619 perror_with_name ("waitpid (WCLONE)");
628 && (!WIFSTOPPED (*wstatp)
629 || (WSTOPSIG (*wstatp) != 32
630 && WSTOPSIG (*wstatp) != 33)))
631 fprintf (stderr, "Got an event from %d (%x)\n", ret, *wstatp);
633 if (to_wait_for == -1)
634 *childp = (struct lwp_info *) find_inferior_id (&all_lwps, ret);
636 /* If we didn't find a process, one of two things presumably happened:
637 - A process we started and then detached from has exited. Ignore it.
638 - A process we are controlling has forked and the new child's stop
639 was reported to us by the kernel. Save its PID. */
640 if (*childp == NULL && WIFSTOPPED (*wstatp))
642 add_pid_to_list (&stopped_pids, ret);
645 else if (*childp == NULL)
648 (*childp)->stopped = 1;
649 (*childp)->pending_is_breakpoint = 0;
651 (*childp)->last_status = *wstatp;
653 /* Architecture-specific setup after inferior is running.
654 This needs to happen after we have attached to the inferior
655 and it is stopped for the first time, but before we access
656 any inferior registers. */
659 the_low_target.arch_setup ();
660 #ifdef HAVE_LINUX_REGSETS
661 memset (disabled_regsets, 0, num_regsets);
667 && WIFSTOPPED (*wstatp))
669 struct thread_info *saved_inferior = current_inferior;
670 current_inferior = (struct thread_info *)
671 find_inferior_id (&all_threads, (*childp)->lwpid);
672 /* For testing only; i386_stop_pc prints out a diagnostic. */
673 if (the_low_target.get_pc != NULL)
675 current_inferior = saved_inferior;
680 linux_wait_for_event (struct thread_info *child)
683 struct lwp_info *event_child;
687 /* Check for a process with a pending status. */
688 /* It is possible that the user changed the pending task's registers since
689 it stopped. We correctly handle the change of PC if we hit a breakpoint
690 (in check_removed_breakpoint); signals should be reported anyway. */
693 event_child = (struct lwp_info *)
694 find_inferior (&all_lwps, status_pending_p, NULL);
695 if (debug_threads && event_child)
696 fprintf (stderr, "Got a pending child %ld\n", event_child->lwpid);
700 event_child = get_thread_lwp (child);
701 if (event_child->status_pending_p
702 && check_removed_breakpoint (event_child))
706 if (event_child != NULL)
708 if (event_child->status_pending_p)
711 fprintf (stderr, "Got an event from pending child %ld (%04x)\n",
712 event_child->lwpid, event_child->status_pending);
713 wstat = event_child->status_pending;
714 event_child->status_pending_p = 0;
715 event_child->status_pending = 0;
716 current_inferior = get_lwp_thread (event_child);
721 /* We only enter this loop if no process has a pending wait status. Thus
722 any action taken in response to a wait status inside this loop is
723 responding as soon as we detect the status, not after any pending
730 event_child = get_thread_lwp (child);
732 linux_wait_for_lwp (&event_child, &wstat);
734 if (event_child == NULL)
735 error ("event from unknown child");
737 current_inferior = (struct thread_info *)
738 find_inferior_id (&all_threads, event_child->lwpid);
740 /* Check for thread exit. */
741 if (! WIFSTOPPED (wstat))
744 fprintf (stderr, "LWP %ld exiting\n", event_child->head.id);
746 /* If the last thread is exiting, just return. */
747 if (all_threads.head == all_threads.tail)
750 dead_thread_notify (thread_id_to_gdb_id (event_child->lwpid));
752 remove_inferior (&all_lwps, &event_child->head);
754 remove_thread (current_inferior);
755 current_inferior = (struct thread_info *) all_threads.head;
757 /* If we were waiting for this particular child to do something...
758 well, it did something. */
762 /* Wait for a more interesting event. */
766 if (WIFSTOPPED (wstat)
767 && WSTOPSIG (wstat) == SIGSTOP
768 && event_child->stop_expected)
771 fprintf (stderr, "Expected stop.\n");
772 event_child->stop_expected = 0;
773 linux_resume_one_lwp (&event_child->head,
774 event_child->stepping, 0, NULL);
778 if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP
781 handle_extended_wait (event_child, wstat);
785 /* If GDB is not interested in this signal, don't stop other
786 threads, and don't report it to GDB. Just resume the
787 inferior right away. We do this for threading-related
788 signals as well as any that GDB specifically requested we
789 ignore. But never ignore SIGSTOP if we sent it ourselves,
790 and do not ignore signals when stepping - they may require
791 special handling to skip the signal handler. */
792 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
794 if (WIFSTOPPED (wstat)
795 && !event_child->stepping
798 (thread_db_active && (WSTOPSIG (wstat) == __SIGRTMIN
799 || WSTOPSIG (wstat) == __SIGRTMIN + 1))
802 (pass_signals[target_signal_from_host (WSTOPSIG (wstat))]
803 && (WSTOPSIG (wstat) != SIGSTOP || !stopping_threads))))
805 siginfo_t info, *info_p;
808 fprintf (stderr, "Ignored signal %d for LWP %ld.\n",
809 WSTOPSIG (wstat), event_child->head.id);
811 if (ptrace (PTRACE_GETSIGINFO, event_child->lwpid, 0, &info) == 0)
815 linux_resume_one_lwp (&event_child->head,
816 event_child->stepping,
817 WSTOPSIG (wstat), info_p);
821 /* If this event was not handled above, and is not a SIGTRAP, report
823 if (!WIFSTOPPED (wstat) || WSTOPSIG (wstat) != SIGTRAP)
826 /* If this target does not support breakpoints, we simply report the
827 SIGTRAP; it's of no concern to us. */
828 if (the_low_target.get_pc == NULL)
831 stop_pc = get_stop_pc ();
833 /* bp_reinsert will only be set if we were single-stepping.
834 Notice that we will resume the process after hitting
835 a gdbserver breakpoint; single-stepping to/over one
836 is not supported (yet). */
837 if (event_child->bp_reinsert != 0)
840 fprintf (stderr, "Reinserted breakpoint.\n");
841 reinsert_breakpoint (event_child->bp_reinsert);
842 event_child->bp_reinsert = 0;
844 /* Clear the single-stepping flag and SIGTRAP as we resume. */
845 linux_resume_one_lwp (&event_child->head, 0, 0, NULL);
849 bp_status = check_breakpoints (stop_pc);
854 fprintf (stderr, "Hit a gdbserver breakpoint.\n");
856 /* We hit one of our own breakpoints. We mark it as a pending
857 breakpoint, so that check_removed_breakpoint () will do the PC
858 adjustment for us at the appropriate time. */
859 event_child->pending_is_breakpoint = 1;
860 event_child->pending_stop_pc = stop_pc;
862 /* We may need to put the breakpoint back. We continue in the event
863 loop instead of simply replacing the breakpoint right away,
864 in order to not lose signals sent to the thread that hit the
865 breakpoint. Unfortunately this increases the window where another
866 thread could sneak past the removed breakpoint. For the current
867 use of server-side breakpoints (thread creation) this is
868 acceptable; but it needs to be considered before this breakpoint
869 mechanism can be used in more general ways. For some breakpoints
870 it may be necessary to stop all other threads, but that should
871 be avoided where possible.
873 If breakpoint_reinsert_addr is NULL, that means that we can
874 use PTRACE_SINGLESTEP on this platform. Uninsert the breakpoint,
875 mark it for reinsertion, and single-step.
877 Otherwise, call the target function to figure out where we need
878 our temporary breakpoint, create it, and continue executing this
881 /* No need to reinsert. */
882 linux_resume_one_lwp (&event_child->head, 0, 0, NULL);
883 else if (the_low_target.breakpoint_reinsert_addr == NULL)
885 event_child->bp_reinsert = stop_pc;
886 uninsert_breakpoint (stop_pc);
887 linux_resume_one_lwp (&event_child->head, 1, 0, NULL);
891 reinsert_breakpoint_by_bp
892 (stop_pc, (*the_low_target.breakpoint_reinsert_addr) ());
893 linux_resume_one_lwp (&event_child->head, 0, 0, NULL);
900 fprintf (stderr, "Hit a non-gdbserver breakpoint.\n");
902 /* If we were single-stepping, we definitely want to report the
903 SIGTRAP. Although the single-step operation has completed,
904 do not clear clear the stepping flag yet; we need to check it
905 in wait_for_sigstop. */
906 if (event_child->stepping)
909 /* A SIGTRAP that we can't explain. It may have been a breakpoint.
910 Check if it is a breakpoint, and if so mark the process information
911 accordingly. This will handle both the necessary fiddling with the
912 PC on decr_pc_after_break targets and suppressing extra threads
913 hitting a breakpoint if two hit it at once and then GDB removes it
914 after the first is reported. Arguably it would be better to report
915 multiple threads hitting breakpoints simultaneously, but the current
916 remote protocol does not allow this. */
917 if ((*the_low_target.breakpoint_at) (stop_pc))
919 event_child->pending_is_breakpoint = 1;
920 event_child->pending_stop_pc = stop_pc;
930 /* Wait for process, returns status. */
933 linux_wait (struct target_waitstatus *ourstatus)
936 struct thread_info *child = NULL;
937 struct lwp_info *lwp;
940 /* If we were only supposed to resume one thread, only wait for
941 that thread - if it's still alive. If it died, however - which
942 can happen if we're coming from the thread death case below -
943 then we need to make sure we restart the other threads. We could
944 pick a thread at random or restart all; restarting all is less
946 if (cont_thread != 0 && cont_thread != -1)
948 child = (struct thread_info *) find_inferior_id (&all_threads,
951 /* No stepping, no signal - unless one is pending already, of course. */
954 struct thread_resume resume_info;
955 resume_info.thread = -1;
956 resume_info.step = resume_info.sig = 0;
957 linux_resume (&resume_info, 1);
961 w = linux_wait_for_event (child);
964 if (must_set_ptrace_flags)
966 ptrace (PTRACE_SETOPTIONS, inferior_pid, 0, PTRACE_O_TRACECLONE);
967 must_set_ptrace_flags = 0;
970 lwp = get_thread_lwp (current_inferior);
972 /* If we are waiting for a particular child, and it exited,
973 linux_wait_for_event will return its exit status. Similarly if
974 the last child exited. If this is not the last child, however,
975 do not report it as exited until there is a 'thread exited' response
976 available in the remote protocol. Instead, just wait for another event.
977 This should be safe, because if the thread crashed we will already
978 have reported the termination signal to GDB; that should stop any
979 in-progress stepping operations, etc.
981 Report the exit status of the last thread to exit. This matches
982 LinuxThreads' behavior. */
984 if (all_threads.head == all_threads.tail)
986 int pid = pid_of (lwp);
990 fprintf (stderr, "\nChild exited with retcode = %x \n",
993 ourstatus->kind = TARGET_WAITKIND_EXITED;
994 ourstatus->value.integer = WEXITSTATUS (w);
996 free (all_lwps.head);
997 all_lwps.head = all_lwps.tail = NULL;
1001 else if (!WIFSTOPPED (w))
1004 fprintf (stderr, "\nChild terminated with signal = %x \n",
1007 ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
1008 ourstatus->value.sig = target_signal_from_host (WTERMSIG (w));
1010 free (all_lwps.head);
1011 all_lwps.head = all_lwps.tail = NULL;
1018 if (!WIFSTOPPED (w))
1022 ourstatus->kind = TARGET_WAITKIND_STOPPED;
1023 ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
1028 /* Send a signal to an LWP. For LinuxThreads, kill is enough; however, if
1029 thread groups are in use, we need to use tkill. */
1032 kill_lwp (unsigned long lwpid, int signo)
1034 static int tkill_failed;
1041 int ret = syscall (SYS_tkill, lwpid, signo);
1042 if (errno != ENOSYS)
1049 return kill (lwpid, signo);
1053 send_sigstop (struct inferior_list_entry *entry)
1055 struct lwp_info *lwp = (struct lwp_info *) entry;
1060 /* If we already have a pending stop signal for this process, don't
1062 if (lwp->stop_expected)
1065 fprintf (stderr, "Have pending sigstop for lwp %ld\n",
1068 /* We clear the stop_expected flag so that wait_for_sigstop
1069 will receive the SIGSTOP event (instead of silently resuming and
1070 waiting again). It'll be reset below. */
1071 lwp->stop_expected = 0;
1076 fprintf (stderr, "Sending sigstop to lwp %ld\n", lwp->head.id);
1078 kill_lwp (lwp->head.id, SIGSTOP);
1082 wait_for_sigstop (struct inferior_list_entry *entry)
1084 struct lwp_info *lwp = (struct lwp_info *) entry;
1085 struct thread_info *saved_inferior, *thread;
1087 unsigned long saved_tid;
1092 saved_inferior = current_inferior;
1093 saved_tid = ((struct inferior_list_entry *) saved_inferior)->id;
1094 thread = (struct thread_info *) find_inferior_id (&all_threads,
1096 wstat = linux_wait_for_event (thread);
1098 /* If we stopped with a non-SIGSTOP signal, save it for later
1099 and record the pending SIGSTOP. If the process exited, just
1101 if (WIFSTOPPED (wstat)
1102 && WSTOPSIG (wstat) != SIGSTOP)
1105 fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n",
1108 /* Do not leave a pending single-step finish to be reported to
1109 the client. The client will give us a new action for this
1110 thread, possibly a continue request --- otherwise, the client
1111 would consider this pending SIGTRAP reported later a spurious
1113 if (WSTOPSIG (wstat) == SIGTRAP
1115 && !linux_stopped_by_watchpoint ())
1118 fprintf (stderr, " single-step SIGTRAP ignored\n");
1122 lwp->status_pending_p = 1;
1123 lwp->status_pending = wstat;
1125 lwp->stop_expected = 1;
1128 if (linux_thread_alive (saved_tid))
1129 current_inferior = saved_inferior;
1133 fprintf (stderr, "Previously current thread died.\n");
1135 /* Set a valid thread as current. */
1136 set_desired_inferior (0);
1141 stop_all_lwps (void)
1143 stopping_threads = 1;
1144 for_each_inferior (&all_lwps, send_sigstop);
1145 for_each_inferior (&all_lwps, wait_for_sigstop);
1146 stopping_threads = 0;
1149 /* Resume execution of the inferior process.
1150 If STEP is nonzero, single-step it.
1151 If SIGNAL is nonzero, give it that signal. */
1154 linux_resume_one_lwp (struct inferior_list_entry *entry,
1155 int step, int signal, siginfo_t *info)
1157 struct lwp_info *lwp = (struct lwp_info *) entry;
1158 struct thread_info *saved_inferior;
1160 if (lwp->stopped == 0)
1163 /* If we have pending signals or status, and a new signal, enqueue the
1164 signal. Also enqueue the signal if we are waiting to reinsert a
1165 breakpoint; it will be picked up again below. */
1167 && (lwp->status_pending_p || lwp->pending_signals != NULL
1168 || lwp->bp_reinsert != 0))
1170 struct pending_signals *p_sig;
1171 p_sig = xmalloc (sizeof (*p_sig));
1172 p_sig->prev = lwp->pending_signals;
1173 p_sig->signal = signal;
1175 memset (&p_sig->info, 0, sizeof (siginfo_t));
1177 memcpy (&p_sig->info, info, sizeof (siginfo_t));
1178 lwp->pending_signals = p_sig;
1181 if (lwp->status_pending_p && !check_removed_breakpoint (lwp))
1184 saved_inferior = current_inferior;
1185 current_inferior = get_lwp_thread (lwp);
1188 fprintf (stderr, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
1189 inferior_pid, step ? "step" : "continue", signal,
1190 lwp->stop_expected ? "expected" : "not expected");
1192 /* This bit needs some thinking about. If we get a signal that
1193 we must report while a single-step reinsert is still pending,
1194 we often end up resuming the thread. It might be better to
1195 (ew) allow a stack of pending events; then we could be sure that
1196 the reinsert happened right away and not lose any signals.
1198 Making this stack would also shrink the window in which breakpoints are
1199 uninserted (see comment in linux_wait_for_lwp) but not enough for
1200 complete correctness, so it won't solve that problem. It may be
1201 worthwhile just to solve this one, however. */
1202 if (lwp->bp_reinsert != 0)
1205 fprintf (stderr, " pending reinsert at %08lx", (long)lwp->bp_reinsert);
1207 fprintf (stderr, "BAD - reinserting but not stepping.\n");
1210 /* Postpone any pending signal. It was enqueued above. */
1214 check_removed_breakpoint (lwp);
1216 if (debug_threads && the_low_target.get_pc != NULL)
1218 fprintf (stderr, " ");
1219 (*the_low_target.get_pc) ();
1222 /* If we have pending signals, consume one unless we are trying to reinsert
1224 if (lwp->pending_signals != NULL && lwp->bp_reinsert == 0)
1226 struct pending_signals **p_sig;
1228 p_sig = &lwp->pending_signals;
1229 while ((*p_sig)->prev != NULL)
1230 p_sig = &(*p_sig)->prev;
1232 signal = (*p_sig)->signal;
1233 if ((*p_sig)->info.si_signo != 0)
1234 ptrace (PTRACE_SETSIGINFO, lwp->lwpid, 0, &(*p_sig)->info);
1240 regcache_invalidate_one ((struct inferior_list_entry *)
1241 get_lwp_thread (lwp));
1244 lwp->stepping = step;
1245 ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwp->lwpid, 0, signal);
1247 current_inferior = saved_inferior;
1250 /* ESRCH from ptrace either means that the thread was already
1251 running (an error) or that it is gone (a race condition). If
1252 it's gone, we will get a notification the next time we wait,
1253 so we can ignore the error. We could differentiate these
1254 two, but it's tricky without waiting; the thread still exists
1255 as a zombie, so sending it signal 0 would succeed. So just
1260 perror_with_name ("ptrace");
1264 struct thread_resume_array
1266 struct thread_resume *resume;
1270 /* This function is called once per thread. We look up the thread
1271 in RESUME_PTR, and mark the thread with a pointer to the appropriate
1274 This algorithm is O(threads * resume elements), but resume elements
1275 is small (and will remain small at least until GDB supports thread
1278 linux_set_resume_request (struct inferior_list_entry *entry, void *arg)
1280 struct lwp_info *lwp;
1281 struct thread_info *thread;
1283 struct thread_resume_array *r;
1285 thread = (struct thread_info *) entry;
1286 lwp = get_thread_lwp (thread);
1289 for (ndx = 0; ndx < r->n; ndx++)
1290 if (r->resume[ndx].thread == -1 || r->resume[ndx].thread == entry->id)
1292 lwp->resume = &r->resume[ndx];
1296 /* No resume action for this thread. */
1302 /* This function is called once per thread. We check the thread's resume
1303 request, which will tell us whether to resume, step, or leave the thread
1304 stopped; and what signal, if any, it should be sent. For threads which
1305 we aren't explicitly told otherwise, we preserve the stepping flag; this
1306 is used for stepping over gdbserver-placed breakpoints. */
1309 linux_continue_one_thread (struct inferior_list_entry *entry)
1311 struct lwp_info *lwp;
1312 struct thread_info *thread;
1315 thread = (struct thread_info *) entry;
1316 lwp = get_thread_lwp (thread);
1318 if (lwp->resume == NULL)
1321 if (lwp->resume->thread == -1
1323 && lwp->pending_is_breakpoint)
1326 step = lwp->resume->step;
1328 linux_resume_one_lwp (&lwp->head, step, lwp->resume->sig, NULL);
1333 /* This function is called once per thread. We check the thread's resume
1334 request, which will tell us whether to resume, step, or leave the thread
1335 stopped; and what signal, if any, it should be sent. We queue any needed
1336 signals, since we won't actually resume. We already have a pending event
1337 to report, so we don't need to preserve any step requests; they should
1338 be re-issued if necessary. */
1341 linux_queue_one_thread (struct inferior_list_entry *entry)
1343 struct lwp_info *lwp;
1344 struct thread_info *thread;
1346 thread = (struct thread_info *) entry;
1347 lwp = get_thread_lwp (thread);
1349 if (lwp->resume == NULL)
1352 /* If we have a new signal, enqueue the signal. */
1353 if (lwp->resume->sig != 0)
1355 struct pending_signals *p_sig;
1356 p_sig = xmalloc (sizeof (*p_sig));
1357 p_sig->prev = lwp->pending_signals;
1358 p_sig->signal = lwp->resume->sig;
1359 memset (&p_sig->info, 0, sizeof (siginfo_t));
1361 /* If this is the same signal we were previously stopped by,
1362 make sure to queue its siginfo. We can ignore the return
1363 value of ptrace; if it fails, we'll skip
1364 PTRACE_SETSIGINFO. */
1365 if (WIFSTOPPED (lwp->last_status)
1366 && WSTOPSIG (lwp->last_status) == lwp->resume->sig)
1367 ptrace (PTRACE_GETSIGINFO, lwp->lwpid, 0, &p_sig->info);
1369 lwp->pending_signals = p_sig;
1375 /* Set DUMMY if this process has an interesting status pending. */
1377 resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p)
1379 struct lwp_info *lwp = (struct lwp_info *) entry;
1381 /* Processes which will not be resumed are not interesting, because
1382 we might not wait for them next time through linux_wait. */
1383 if (lwp->resume == NULL)
1386 /* If this thread has a removed breakpoint, we won't have any
1387 events to report later, so check now. check_removed_breakpoint
1388 may clear status_pending_p. We avoid calling check_removed_breakpoint
1389 for any thread that we are not otherwise going to resume - this
1390 lets us preserve stopped status when two threads hit a breakpoint.
1391 GDB removes the breakpoint to single-step a particular thread
1392 past it, then re-inserts it and resumes all threads. We want
1393 to report the second thread without resuming it in the interim. */
1394 if (lwp->status_pending_p)
1395 check_removed_breakpoint (lwp);
1397 if (lwp->status_pending_p)
1398 * (int *) flag_p = 1;
1404 linux_resume (struct thread_resume *resume_info, size_t n)
1407 struct thread_resume_array array = { resume_info, n };
1409 find_inferior (&all_threads, linux_set_resume_request, &array);
1411 /* If there is a thread which would otherwise be resumed, which
1412 has a pending status, then don't resume any threads - we can just
1413 report the pending status. Make sure to queue any signals
1414 that would otherwise be sent. */
1416 find_inferior (&all_lwps, resume_status_pending_p, &pending_flag);
1421 fprintf (stderr, "Not resuming, pending status\n");
1423 fprintf (stderr, "Resuming, no pending status\n");
1427 for_each_inferior (&all_threads, linux_queue_one_thread);
1429 for_each_inferior (&all_threads, linux_continue_one_thread);
1432 #ifdef HAVE_LINUX_USRREGS
1435 register_addr (int regnum)
1439 if (regnum < 0 || regnum >= the_low_target.num_regs)
1440 error ("Invalid register number %d.", regnum);
1442 addr = the_low_target.regmap[regnum];
1447 /* Fetch one register. */
1449 fetch_register (int regno)
1455 if (regno >= the_low_target.num_regs)
1457 if ((*the_low_target.cannot_fetch_register) (regno))
1460 regaddr = register_addr (regno);
1463 size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
1464 & - sizeof (PTRACE_XFER_TYPE));
1465 buf = alloca (size);
1466 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
1469 *(PTRACE_XFER_TYPE *) (buf + i) =
1470 ptrace (PTRACE_PEEKUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, 0);
1471 regaddr += sizeof (PTRACE_XFER_TYPE);
1474 /* Warning, not error, in case we are attached; sometimes the
1475 kernel doesn't let us at the registers. */
1476 char *err = strerror (errno);
1477 char *msg = alloca (strlen (err) + 128);
1478 sprintf (msg, "reading register %d: %s", regno, err);
1484 if (the_low_target.supply_ptrace_register)
1485 the_low_target.supply_ptrace_register (regno, buf);
1487 supply_register (regno, buf);
1492 /* Fetch all registers, or just one, from the child process. */
1494 usr_fetch_inferior_registers (int regno)
1496 if (regno == -1 || regno == 0)
1497 for (regno = 0; regno < the_low_target.num_regs; regno++)
1498 fetch_register (regno);
1500 fetch_register (regno);
1503 /* Store our register values back into the inferior.
1504 If REGNO is -1, do this for all registers.
1505 Otherwise, REGNO specifies which register (so we can save time). */
1507 usr_store_inferior_registers (int regno)
1515 if (regno >= the_low_target.num_regs)
1518 if ((*the_low_target.cannot_store_register) (regno) == 1)
1521 regaddr = register_addr (regno);
1525 size = (register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
1526 & - sizeof (PTRACE_XFER_TYPE);
1527 buf = alloca (size);
1528 memset (buf, 0, size);
1530 if (the_low_target.collect_ptrace_register)
1531 the_low_target.collect_ptrace_register (regno, buf);
1533 collect_register (regno, buf);
1535 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
1538 ptrace (PTRACE_POKEUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
1539 *(PTRACE_XFER_TYPE *) (buf + i));
1542 /* At this point, ESRCH should mean the process is
1543 already gone, in which case we simply ignore attempts
1544 to change its registers. See also the related
1545 comment in linux_resume_one_lwp. */
1549 if ((*the_low_target.cannot_store_register) (regno) == 0)
1551 char *err = strerror (errno);
1552 char *msg = alloca (strlen (err) + 128);
1553 sprintf (msg, "writing register %d: %s",
1559 regaddr += sizeof (PTRACE_XFER_TYPE);
1563 for (regno = 0; regno < the_low_target.num_regs; regno++)
1564 usr_store_inferior_registers (regno);
1566 #endif /* HAVE_LINUX_USRREGS */
1570 #ifdef HAVE_LINUX_REGSETS
1573 regsets_fetch_inferior_registers ()
1575 struct regset_info *regset;
1576 int saw_general_regs = 0;
1578 regset = target_regsets;
1580 while (regset->size >= 0)
1585 if (regset->size == 0 || disabled_regsets[regset - target_regsets])
1591 buf = xmalloc (regset->size);
1593 res = ptrace (regset->get_request, inferior_pid, 0, buf);
1595 res = ptrace (regset->get_request, inferior_pid, buf, 0);
1601 /* If we get EIO on a regset, do not try it again for
1603 disabled_regsets[regset - target_regsets] = 1;
1609 sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%ld",
1614 else if (regset->type == GENERAL_REGS)
1615 saw_general_regs = 1;
1616 regset->store_function (buf);
1619 if (saw_general_regs)
1626 regsets_store_inferior_registers ()
1628 struct regset_info *regset;
1629 int saw_general_regs = 0;
1631 regset = target_regsets;
1633 while (regset->size >= 0)
1638 if (regset->size == 0 || disabled_regsets[regset - target_regsets])
1644 buf = xmalloc (regset->size);
1646 /* First fill the buffer with the current register set contents,
1647 in case there are any items in the kernel's regset that are
1648 not in gdbserver's regcache. */
1650 res = ptrace (regset->get_request, inferior_pid, 0, buf);
1652 res = ptrace (regset->get_request, inferior_pid, buf, 0);
1657 /* Then overlay our cached registers on that. */
1658 regset->fill_function (buf);
1660 /* Only now do we write the register set. */
1662 res = ptrace (regset->set_request, inferior_pid, 0, buf);
1664 res = ptrace (regset->set_request, inferior_pid, buf, 0);
1672 /* If we get EIO on a regset, do not try it again for
1674 disabled_regsets[regset - target_regsets] = 1;
1677 else if (errno == ESRCH)
1679 /* At this point, ESRCH should mean the process is
1680 already gone, in which case we simply ignore attempts
1681 to change its registers. See also the related
1682 comment in linux_resume_one_lwp. */
1687 perror ("Warning: ptrace(regsets_store_inferior_registers)");
1690 else if (regset->type == GENERAL_REGS)
1691 saw_general_regs = 1;
1695 if (saw_general_regs)
1702 #endif /* HAVE_LINUX_REGSETS */
1706 linux_fetch_registers (int regno)
1708 #ifdef HAVE_LINUX_REGSETS
1709 if (regsets_fetch_inferior_registers () == 0)
1712 #ifdef HAVE_LINUX_USRREGS
1713 usr_fetch_inferior_registers (regno);
1718 linux_store_registers (int regno)
1720 #ifdef HAVE_LINUX_REGSETS
1721 if (regsets_store_inferior_registers () == 0)
1724 #ifdef HAVE_LINUX_USRREGS
1725 usr_store_inferior_registers (regno);
1730 /* Copy LEN bytes from inferior's memory starting at MEMADDR
1731 to debugger memory starting at MYADDR. */
1734 linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
1737 /* Round starting address down to longword boundary. */
1738 register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
1739 /* Round ending address up; get number of longwords that makes. */
1741 = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
1742 / sizeof (PTRACE_XFER_TYPE);
1743 /* Allocate buffer of that many longwords. */
1744 register PTRACE_XFER_TYPE *buffer
1745 = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
1749 /* Try using /proc. Don't bother for one word. */
1750 if (len >= 3 * sizeof (long))
1752 /* We could keep this file open and cache it - possibly one per
1753 thread. That requires some juggling, but is even faster. */
1754 sprintf (filename, "/proc/%ld/mem", inferior_pid);
1755 fd = open (filename, O_RDONLY | O_LARGEFILE);
1759 /* If pread64 is available, use it. It's faster if the kernel
1760 supports it (only one syscall), and it's 64-bit safe even on
1761 32-bit platforms (for instance, SPARC debugging a SPARC64
1764 if (pread64 (fd, myaddr, len, memaddr) != len)
1766 if (lseek (fd, memaddr, SEEK_SET) == -1 || read (fd, memaddr, len) != len)
1778 /* Read all the longwords */
1779 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
1782 buffer[i] = ptrace (PTRACE_PEEKTEXT, inferior_pid,
1783 (PTRACE_ARG3_TYPE) addr, 0);
1788 /* Copy appropriate bytes out of the buffer. */
1790 (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
1796 /* Copy LEN bytes of data from debugger memory at MYADDR
1797 to inferior's memory at MEMADDR.
1798 On failure (cannot write the inferior)
1799 returns the value of errno. */
1802 linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
1805 /* Round starting address down to longword boundary. */
1806 register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
1807 /* Round ending address up; get number of longwords that makes. */
1809 = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) / sizeof (PTRACE_XFER_TYPE);
1810 /* Allocate buffer of that many longwords. */
1811 register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
1815 fprintf (stderr, "Writing %02x to %08lx\n", (unsigned)myaddr[0], (long)memaddr);
1818 /* Fill start and end extra bytes of buffer with existing memory data. */
1820 buffer[0] = ptrace (PTRACE_PEEKTEXT, inferior_pid,
1821 (PTRACE_ARG3_TYPE) addr, 0);
1826 = ptrace (PTRACE_PEEKTEXT, inferior_pid,
1827 (PTRACE_ARG3_TYPE) (addr + (count - 1)
1828 * sizeof (PTRACE_XFER_TYPE)),
1832 /* Copy data to be written over corresponding part of buffer */
1834 memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), myaddr, len);
1836 /* Write the entire buffer. */
1838 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
1841 ptrace (PTRACE_POKETEXT, inferior_pid, (PTRACE_ARG3_TYPE) addr, buffer[i]);
1849 static int linux_supports_tracefork_flag;
1851 /* Helper functions for linux_test_for_tracefork, called via clone (). */
1854 linux_tracefork_grandchild (void *arg)
1859 #define STACK_SIZE 4096
1862 linux_tracefork_child (void *arg)
1864 ptrace (PTRACE_TRACEME, 0, 0, 0);
1865 kill (getpid (), SIGSTOP);
1867 __clone2 (linux_tracefork_grandchild, arg, STACK_SIZE,
1868 CLONE_VM | SIGCHLD, NULL);
1870 clone (linux_tracefork_grandchild, arg + STACK_SIZE,
1871 CLONE_VM | SIGCHLD, NULL);
1876 /* Wrapper function for waitpid which handles EINTR. */
1879 my_waitpid (int pid, int *status, int flags)
1884 ret = waitpid (pid, status, flags);
1886 while (ret == -1 && errno == EINTR);
1891 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
1892 sure that we can enable the option, and that it had the desired
1896 linux_test_for_tracefork (void)
1898 int child_pid, ret, status;
1900 char *stack = xmalloc (STACK_SIZE * 4);
1902 linux_supports_tracefork_flag = 0;
1904 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
1906 child_pid = __clone2 (linux_tracefork_child, stack, STACK_SIZE,
1907 CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
1909 child_pid = clone (linux_tracefork_child, stack + STACK_SIZE,
1910 CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
1912 if (child_pid == -1)
1913 perror_with_name ("clone");
1915 ret = my_waitpid (child_pid, &status, 0);
1917 perror_with_name ("waitpid");
1918 else if (ret != child_pid)
1919 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret);
1920 if (! WIFSTOPPED (status))
1921 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status);
1923 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK);
1926 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
1929 warning ("linux_test_for_tracefork: failed to kill child");
1933 ret = my_waitpid (child_pid, &status, 0);
1934 if (ret != child_pid)
1935 warning ("linux_test_for_tracefork: failed to wait for killed child");
1936 else if (!WIFSIGNALED (status))
1937 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
1938 "killed child", status);
1943 ret = ptrace (PTRACE_CONT, child_pid, 0, 0);
1945 warning ("linux_test_for_tracefork: failed to resume child");
1947 ret = my_waitpid (child_pid, &status, 0);
1949 if (ret == child_pid && WIFSTOPPED (status)
1950 && status >> 16 == PTRACE_EVENT_FORK)
1953 ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
1954 if (ret == 0 && second_pid != 0)
1958 linux_supports_tracefork_flag = 1;
1959 my_waitpid (second_pid, &second_status, 0);
1960 ret = ptrace (PTRACE_KILL, second_pid, 0, 0);
1962 warning ("linux_test_for_tracefork: failed to kill second child");
1963 my_waitpid (second_pid, &status, 0);
1967 warning ("linux_test_for_tracefork: unexpected result from waitpid "
1968 "(%d, status 0x%x)", ret, status);
1972 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
1974 warning ("linux_test_for_tracefork: failed to kill child");
1975 my_waitpid (child_pid, &status, 0);
1977 while (WIFSTOPPED (status));
1984 linux_look_up_symbols (void)
1986 #ifdef USE_THREAD_DB
1987 if (thread_db_active)
1990 thread_db_active = thread_db_init (!linux_supports_tracefork_flag);
1995 linux_request_interrupt (void)
1997 extern unsigned long signal_pid;
1999 if (cont_thread != 0 && cont_thread != -1)
2001 struct lwp_info *lwp;
2003 lwp = get_thread_lwp (current_inferior);
2004 kill_lwp (lwp->lwpid, SIGINT);
2007 kill_lwp (signal_pid, SIGINT);
2010 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
2011 to debugger memory starting at MYADDR. */
2014 linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len)
2016 char filename[PATH_MAX];
2019 snprintf (filename, sizeof filename, "/proc/%ld/auxv", inferior_pid);
2021 fd = open (filename, O_RDONLY);
2025 if (offset != (CORE_ADDR) 0
2026 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
2029 n = read (fd, myaddr, len);
2036 /* These watchpoint related wrapper functions simply pass on the function call
2037 if the target has registered a corresponding function. */
2040 linux_insert_watchpoint (char type, CORE_ADDR addr, int len)
2042 if (the_low_target.insert_watchpoint != NULL)
2043 return the_low_target.insert_watchpoint (type, addr, len);
2045 /* Unsupported (see target.h). */
2050 linux_remove_watchpoint (char type, CORE_ADDR addr, int len)
2052 if (the_low_target.remove_watchpoint != NULL)
2053 return the_low_target.remove_watchpoint (type, addr, len);
2055 /* Unsupported (see target.h). */
2060 linux_stopped_by_watchpoint (void)
2062 if (the_low_target.stopped_by_watchpoint != NULL)
2063 return the_low_target.stopped_by_watchpoint ();
2069 linux_stopped_data_address (void)
2071 if (the_low_target.stopped_data_address != NULL)
2072 return the_low_target.stopped_data_address ();
2077 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
2078 #if defined(__mcoldfire__)
2079 /* These should really be defined in the kernel's ptrace.h header. */
2080 #define PT_TEXT_ADDR 49*4
2081 #define PT_DATA_ADDR 50*4
2082 #define PT_TEXT_END_ADDR 51*4
2085 /* Under uClinux, programs are loaded at non-zero offsets, which we need
2086 to tell gdb about. */
2089 linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p)
2091 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
2092 unsigned long text, text_end, data;
2093 int pid = get_thread_lwp (current_inferior)->head.id;
2097 text = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_ADDR, 0);
2098 text_end = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_END_ADDR, 0);
2099 data = ptrace (PTRACE_PEEKUSER, pid, (long)PT_DATA_ADDR, 0);
2103 /* Both text and data offsets produced at compile-time (and so
2104 used by gdb) are relative to the beginning of the program,
2105 with the data segment immediately following the text segment.
2106 However, the actual runtime layout in memory may put the data
2107 somewhere else, so when we send gdb a data base-address, we
2108 use the real data base address and subtract the compile-time
2109 data base-address from it (which is just the length of the
2110 text segment). BSS immediately follows data in both
2113 *data_p = data - (text_end - text);
2123 linux_qxfer_osdata (const char *annex,
2124 unsigned char *readbuf, unsigned const char *writebuf,
2125 CORE_ADDR offset, int len)
2127 /* We make the process list snapshot when the object starts to be
2129 static const char *buf;
2130 static long len_avail = -1;
2131 static struct buffer buffer;
2135 if (strcmp (annex, "processes") != 0)
2138 if (!readbuf || writebuf)
2143 if (len_avail != -1 && len_avail != 0)
2144 buffer_free (&buffer);
2147 buffer_init (&buffer);
2148 buffer_grow_str (&buffer, "<osdata type=\"processes\">");
2150 dirp = opendir ("/proc");
2154 while ((dp = readdir (dirp)) != NULL)
2156 struct stat statbuf;
2157 char procentry[sizeof ("/proc/4294967295")];
2159 if (!isdigit (dp->d_name[0])
2160 || strlen (dp->d_name) > sizeof ("4294967295") - 1)
2163 sprintf (procentry, "/proc/%s", dp->d_name);
2164 if (stat (procentry, &statbuf) == 0
2165 && S_ISDIR (statbuf.st_mode))
2169 char cmd[MAXPATHLEN + 1];
2170 struct passwd *entry;
2172 sprintf (pathname, "/proc/%s/cmdline", dp->d_name);
2173 entry = getpwuid (statbuf.st_uid);
2175 if ((f = fopen (pathname, "r")) != NULL)
2177 size_t len = fread (cmd, 1, sizeof (cmd) - 1, f);
2181 for (i = 0; i < len; i++)
2189 "<column name=\"pid\">%s</column>"
2190 "<column name=\"user\">%s</column>"
2191 "<column name=\"command\">%s</column>"
2194 entry ? entry->pw_name : "?",
2204 buffer_grow_str0 (&buffer, "</osdata>\n");
2205 buf = buffer_finish (&buffer);
2206 len_avail = strlen (buf);
2209 if (offset >= len_avail)
2211 /* Done. Get rid of the data. */
2212 buffer_free (&buffer);
2218 if (len > len_avail - offset)
2219 len = len_avail - offset;
2220 memcpy (readbuf, buf + offset, len);
2226 linux_xfer_siginfo (const char *annex, unsigned char *readbuf,
2227 unsigned const char *writebuf, CORE_ADDR offset, int len)
2229 struct siginfo siginfo;
2232 if (current_inferior == NULL)
2235 pid = pid_of (get_thread_lwp (current_inferior));
2238 fprintf (stderr, "%s siginfo for lwp %ld.\n",
2239 readbuf != NULL ? "Reading" : "Writing",
2242 if (offset > sizeof (siginfo))
2245 if (ptrace (PTRACE_GETSIGINFO, pid, 0, &siginfo) != 0)
2248 if (offset + len > sizeof (siginfo))
2249 len = sizeof (siginfo) - offset;
2251 if (readbuf != NULL)
2252 memcpy (readbuf, (char *) &siginfo + offset, len);
2255 memcpy ((char *) &siginfo + offset, writebuf, len);
2256 if (ptrace (PTRACE_SETSIGINFO, pid, 0, &siginfo) != 0)
2263 static struct target_ops linux_target_ops = {
2264 linux_create_inferior,
2272 linux_fetch_registers,
2273 linux_store_registers,
2276 linux_look_up_symbols,
2277 linux_request_interrupt,
2279 linux_insert_watchpoint,
2280 linux_remove_watchpoint,
2281 linux_stopped_by_watchpoint,
2282 linux_stopped_data_address,
2283 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
2288 #ifdef USE_THREAD_DB
2289 thread_db_get_tls_address,
2294 hostio_last_error_from_errno,
2300 linux_init_signals ()
2302 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
2303 to find what the cancel signal actually is. */
2304 signal (__SIGRTMIN+1, SIG_IGN);
2308 initialize_low (void)
2310 thread_db_active = 0;
2311 set_target_ops (&linux_target_ops);
2312 set_breakpoint_data (the_low_target.breakpoint,
2313 the_low_target.breakpoint_len);
2314 linux_init_signals ();
2315 linux_test_for_tracefork ();
2316 #ifdef HAVE_LINUX_REGSETS
2317 for (num_regsets = 0; target_regsets[num_regsets].size >= 0; num_regsets++)
2319 disabled_regsets = xmalloc (num_regsets);