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);
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);
126 struct pending_signals
130 struct pending_signals *prev;
133 #define PTRACE_ARG3_TYPE long
134 #define PTRACE_XFER_TYPE long
136 #ifdef HAVE_LINUX_REGSETS
137 static char *disabled_regsets;
138 static int num_regsets;
141 #define pid_of(proc) ((proc)->head.id)
143 /* FIXME: Delete eventually. */
144 #define inferior_pid (pid_of (get_thread_lwp (current_inferior)))
147 handle_extended_wait (struct lwp_info *event_child, int wstat)
149 int event = wstat >> 16;
150 struct lwp_info *new_lwp;
152 if (event == PTRACE_EVENT_CLONE)
154 unsigned long new_pid;
155 int ret, status = W_STOPCODE (SIGSTOP);
157 ptrace (PTRACE_GETEVENTMSG, inferior_pid, 0, &new_pid);
159 /* If we haven't already seen the new PID stop, wait for it now. */
160 if (! pull_pid_from_list (&stopped_pids, new_pid))
162 /* The new child has a pending SIGSTOP. We can't affect it until it
163 hits the SIGSTOP, but we're already attached. */
165 ret = my_waitpid (new_pid, &status, __WALL);
168 perror_with_name ("waiting for new child");
169 else if (ret != new_pid)
170 warning ("wait returned unexpected PID %d", ret);
171 else if (!WIFSTOPPED (status))
172 warning ("wait returned unexpected status 0x%x", status);
175 ptrace (PTRACE_SETOPTIONS, new_pid, 0, PTRACE_O_TRACECLONE);
177 new_lwp = (struct lwp_info *) add_lwp (new_pid);
178 add_thread (new_pid, new_lwp, new_pid);
179 new_thread_notify (thread_id_to_gdb_id (new_lwp->lwpid));
181 /* Normally we will get the pending SIGSTOP. But in some cases
182 we might get another signal delivered to the group first.
183 If we do get another signal, be sure not to lose it. */
184 if (WSTOPSIG (status) == SIGSTOP)
186 if (stopping_threads)
187 new_lwp->stopped = 1;
189 ptrace (PTRACE_CONT, new_pid, 0, 0);
193 new_lwp->stop_expected = 1;
194 if (stopping_threads)
196 new_lwp->stopped = 1;
197 new_lwp->status_pending_p = 1;
198 new_lwp->status_pending = status;
201 /* Pass the signal on. This is what GDB does - except
202 shouldn't we really report it instead? */
203 ptrace (PTRACE_CONT, new_pid, 0, WSTOPSIG (status));
206 /* Always resume the current thread. If we are stopping
207 threads, it will have a pending SIGSTOP; we may as well
209 linux_resume_one_lwp (&event_child->head,
210 event_child->stepping, 0, NULL);
214 /* This function should only be called if the process got a SIGTRAP.
215 The SIGTRAP could mean several things.
217 On i386, where decr_pc_after_break is non-zero:
218 If we were single-stepping this process using PTRACE_SINGLESTEP,
219 we will get only the one SIGTRAP (even if the instruction we
220 stepped over was a breakpoint). The value of $eip will be the
222 If we continue the process using PTRACE_CONT, we will get a
223 SIGTRAP when we hit a breakpoint. The value of $eip will be
224 the instruction after the breakpoint (i.e. needs to be
225 decremented). If we report the SIGTRAP to GDB, we must also
226 report the undecremented PC. If we cancel the SIGTRAP, we
227 must resume at the decremented PC.
229 (Presumably, not yet tested) On a non-decr_pc_after_break machine
230 with hardware or kernel single-step:
231 If we single-step over a breakpoint instruction, our PC will
232 point at the following instruction. If we continue and hit a
233 breakpoint instruction, our PC will point at the breakpoint
239 CORE_ADDR stop_pc = (*the_low_target.get_pc) ();
241 if (get_thread_lwp (current_inferior)->stepping)
244 return stop_pc - the_low_target.decr_pc_after_break;
248 add_lwp (unsigned long pid)
250 struct lwp_info *lwp;
252 lwp = (struct lwp_info *) xmalloc (sizeof (*lwp));
253 memset (lwp, 0, sizeof (*lwp));
258 add_inferior_to_list (&all_lwps, &lwp->head);
263 /* Start an inferior process and returns its pid.
264 ALLARGS is a vector of program-name and args. */
267 linux_create_inferior (char *program, char **allargs)
272 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
278 perror_with_name ("fork");
282 ptrace (PTRACE_TRACEME, 0, 0, 0);
284 signal (__SIGRTMIN + 1, SIG_DFL);
288 execv (program, allargs);
290 execvp (program, allargs);
292 fprintf (stderr, "Cannot exec %s: %s.\n", program,
298 new_lwp = add_lwp (pid);
299 add_thread (pid, new_lwp, pid);
300 must_set_ptrace_flags = 1;
306 /* Attach to an inferior process. */
309 linux_attach_lwp (unsigned long pid)
311 struct lwp_info *new_lwp;
313 if (ptrace (PTRACE_ATTACH, pid, 0, 0) != 0)
315 if (all_threads.head != NULL)
317 /* If we fail to attach to an LWP, just warn. */
318 fprintf (stderr, "Cannot attach to lwp %ld: %s (%d)\n", pid,
319 strerror (errno), errno);
324 /* If we fail to attach to a process, report an error. */
325 error ("Cannot attach to process %ld: %s (%d)\n", pid,
326 strerror (errno), errno);
329 /* FIXME: This intermittently fails.
330 We need to wait for SIGSTOP first. */
331 ptrace (PTRACE_SETOPTIONS, pid, 0, PTRACE_O_TRACECLONE);
333 new_lwp = (struct lwp_info *) add_lwp (pid);
334 add_thread (pid, new_lwp, pid);
335 new_thread_notify (thread_id_to_gdb_id (new_lwp->lwpid));
337 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
340 There are several cases to consider here:
342 1) gdbserver has already attached to the process and is being notified
343 of a new thread that is being created.
344 In this case we should ignore that SIGSTOP and resume the process.
345 This is handled below by setting stop_expected = 1.
347 2) This is the first thread (the process thread), and we're attaching
348 to it via attach_inferior.
349 In this case we want the process thread to stop.
350 This is handled by having linux_attach clear stop_expected after
352 ??? If the process already has several threads we leave the other
355 3) GDB is connecting to gdbserver and is requesting an enumeration of all
357 In this case we want the thread to stop.
358 FIXME: This case is currently not properly handled.
359 We should wait for the SIGSTOP but don't. Things work apparently
360 because enough time passes between when we ptrace (ATTACH) and when
361 gdb makes the next ptrace call on the thread.
363 On the other hand, if we are currently trying to stop all threads, we
364 should treat the new thread as if we had sent it a SIGSTOP. This works
365 because we are guaranteed that the add_lwp call above added us to the
366 end of the list, and so the new thread has not yet reached
367 wait_for_sigstop (but will). */
368 if (! stopping_threads)
369 new_lwp->stop_expected = 1;
373 linux_attach (unsigned long pid)
375 struct lwp_info *lwp;
377 linux_attach_lwp (pid);
379 /* Don't ignore the initial SIGSTOP if we just attached to this process.
380 It will be collected by wait shortly. */
381 lwp = (struct lwp_info *) find_inferior_id (&all_lwps, pid);
382 lwp->stop_expected = 0;
389 /* Kill the inferior process. Make us have no inferior. */
392 linux_kill_one_lwp (struct inferior_list_entry *entry)
394 struct thread_info *thread = (struct thread_info *) entry;
395 struct lwp_info *lwp = get_thread_lwp (thread);
398 /* We avoid killing the first thread here, because of a Linux kernel (at
399 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
400 the children get a chance to be reaped, it will remain a zombie
402 if (entry == all_threads.head)
407 ptrace (PTRACE_KILL, pid_of (lwp), 0, 0);
409 /* Make sure it died. The loop is most likely unnecessary. */
410 wstat = linux_wait_for_event (thread);
411 } while (WIFSTOPPED (wstat));
417 struct thread_info *thread = (struct thread_info *) all_threads.head;
418 struct lwp_info *lwp;
424 for_each_inferior (&all_threads, linux_kill_one_lwp);
426 /* See the comment in linux_kill_one_lwp. We did not kill the first
427 thread in the list, so do so now. */
428 lwp = get_thread_lwp (thread);
431 ptrace (PTRACE_KILL, pid_of (lwp), 0, 0);
433 /* Make sure it died. The loop is most likely unnecessary. */
434 wstat = linux_wait_for_event (thread);
435 } while (WIFSTOPPED (wstat));
438 free (all_lwps.head);
439 all_lwps.head = all_lwps.tail = NULL;
443 linux_detach_one_lwp (struct inferior_list_entry *entry)
445 struct thread_info *thread = (struct thread_info *) entry;
446 struct lwp_info *lwp = get_thread_lwp (thread);
448 /* Make sure the process isn't stopped at a breakpoint that's
450 check_removed_breakpoint (lwp);
452 /* If this process is stopped but is expecting a SIGSTOP, then make
453 sure we take care of that now. This isn't absolutely guaranteed
454 to collect the SIGSTOP, but is fairly likely to. */
455 if (lwp->stop_expected)
457 /* Clear stop_expected, so that the SIGSTOP will be reported. */
458 lwp->stop_expected = 0;
460 linux_resume_one_lwp (&lwp->head, 0, 0, NULL);
461 linux_wait_for_event (thread);
464 /* Flush any pending changes to the process's registers. */
465 regcache_invalidate_one ((struct inferior_list_entry *)
466 get_lwp_thread (lwp));
468 /* Finally, let it resume. */
469 ptrace (PTRACE_DETACH, pid_of (lwp), 0, 0);
475 delete_all_breakpoints ();
476 for_each_inferior (&all_threads, linux_detach_one_lwp);
478 free (all_lwps.head);
479 all_lwps.head = all_lwps.tail = NULL;
486 extern unsigned long signal_pid;
490 ret = waitpid (signal_pid, &status, 0);
491 if (WIFEXITED (status) || WIFSIGNALED (status))
493 } while (ret != -1 || errno != ECHILD);
496 /* Return nonzero if the given thread is still alive. */
498 linux_thread_alive (unsigned long lwpid)
500 if (find_inferior_id (&all_threads, lwpid) != NULL)
506 /* Return nonzero if this process stopped at a breakpoint which
507 no longer appears to be inserted. Also adjust the PC
508 appropriately to resume where the breakpoint used to be. */
510 check_removed_breakpoint (struct lwp_info *event_child)
513 struct thread_info *saved_inferior;
515 if (event_child->pending_is_breakpoint == 0)
519 fprintf (stderr, "Checking for breakpoint in lwp %ld.\n",
522 saved_inferior = current_inferior;
523 current_inferior = get_lwp_thread (event_child);
525 stop_pc = get_stop_pc ();
527 /* If the PC has changed since we stopped, then we shouldn't do
528 anything. This happens if, for instance, GDB handled the
529 decr_pc_after_break subtraction itself. */
530 if (stop_pc != event_child->pending_stop_pc)
533 fprintf (stderr, "Ignoring, PC was changed. Old PC was 0x%08llx\n",
534 event_child->pending_stop_pc);
536 event_child->pending_is_breakpoint = 0;
537 current_inferior = saved_inferior;
541 /* If the breakpoint is still there, we will report hitting it. */
542 if ((*the_low_target.breakpoint_at) (stop_pc))
545 fprintf (stderr, "Ignoring, breakpoint is still present.\n");
546 current_inferior = saved_inferior;
551 fprintf (stderr, "Removed breakpoint.\n");
553 /* For decr_pc_after_break targets, here is where we perform the
554 decrement. We go immediately from this function to resuming,
555 and can not safely call get_stop_pc () again. */
556 if (the_low_target.set_pc != NULL)
557 (*the_low_target.set_pc) (stop_pc);
559 /* We consumed the pending SIGTRAP. */
560 event_child->pending_is_breakpoint = 0;
561 event_child->status_pending_p = 0;
562 event_child->status_pending = 0;
564 current_inferior = saved_inferior;
568 /* Return 1 if this lwp has an interesting status pending. This
569 function may silently resume an inferior lwp. */
571 status_pending_p (struct inferior_list_entry *entry, void *dummy)
573 struct lwp_info *lwp = (struct lwp_info *) entry;
575 if (lwp->status_pending_p)
576 if (check_removed_breakpoint (lwp))
578 /* This thread was stopped at a breakpoint, and the breakpoint
579 is now gone. We were told to continue (or step...) all threads,
580 so GDB isn't trying to single-step past this breakpoint.
581 So instead of reporting the old SIGTRAP, pretend we got to
582 the breakpoint just after it was removed instead of just
583 before; resume the process. */
584 linux_resume_one_lwp (&lwp->head, 0, 0, NULL);
588 return lwp->status_pending_p;
592 linux_wait_for_lwp (struct lwp_info **childp, int *wstatp)
595 int to_wait_for = -1;
598 to_wait_for = (*childp)->lwpid;
603 ret = waitpid (to_wait_for, wstatp, WNOHANG);
608 perror_with_name ("waitpid");
613 ret = waitpid (to_wait_for, wstatp, WNOHANG | __WCLONE);
618 perror_with_name ("waitpid (WCLONE)");
627 && (!WIFSTOPPED (*wstatp)
628 || (WSTOPSIG (*wstatp) != 32
629 && WSTOPSIG (*wstatp) != 33)))
630 fprintf (stderr, "Got an event from %d (%x)\n", ret, *wstatp);
632 if (to_wait_for == -1)
633 *childp = (struct lwp_info *) find_inferior_id (&all_lwps, ret);
635 /* If we didn't find a process, one of two things presumably happened:
636 - A process we started and then detached from has exited. Ignore it.
637 - A process we are controlling has forked and the new child's stop
638 was reported to us by the kernel. Save its PID. */
639 if (*childp == NULL && WIFSTOPPED (*wstatp))
641 add_pid_to_list (&stopped_pids, ret);
644 else if (*childp == NULL)
647 (*childp)->stopped = 1;
648 (*childp)->pending_is_breakpoint = 0;
650 (*childp)->last_status = *wstatp;
652 /* Architecture-specific setup after inferior is running.
653 This needs to happen after we have attached to the inferior
654 and it is stopped for the first time, but before we access
655 any inferior registers. */
658 the_low_target.arch_setup ();
659 #ifdef HAVE_LINUX_REGSETS
660 memset (disabled_regsets, 0, num_regsets);
666 && WIFSTOPPED (*wstatp))
668 struct thread_info *saved_inferior = current_inferior;
669 current_inferior = (struct thread_info *)
670 find_inferior_id (&all_threads, (*childp)->lwpid);
671 /* For testing only; i386_stop_pc prints out a diagnostic. */
672 if (the_low_target.get_pc != NULL)
674 current_inferior = saved_inferior;
679 linux_wait_for_event (struct thread_info *child)
682 struct lwp_info *event_child;
686 /* Check for a process with a pending status. */
687 /* It is possible that the user changed the pending task's registers since
688 it stopped. We correctly handle the change of PC if we hit a breakpoint
689 (in check_removed_breakpoint); signals should be reported anyway. */
692 event_child = (struct lwp_info *)
693 find_inferior (&all_lwps, status_pending_p, NULL);
694 if (debug_threads && event_child)
695 fprintf (stderr, "Got a pending child %ld\n", event_child->lwpid);
699 event_child = get_thread_lwp (child);
700 if (event_child->status_pending_p
701 && check_removed_breakpoint (event_child))
705 if (event_child != NULL)
707 if (event_child->status_pending_p)
710 fprintf (stderr, "Got an event from pending child %ld (%04x)\n",
711 event_child->lwpid, event_child->status_pending);
712 wstat = event_child->status_pending;
713 event_child->status_pending_p = 0;
714 event_child->status_pending = 0;
715 current_inferior = get_lwp_thread (event_child);
720 /* We only enter this loop if no process has a pending wait status. Thus
721 any action taken in response to a wait status inside this loop is
722 responding as soon as we detect the status, not after any pending
729 event_child = get_thread_lwp (child);
731 linux_wait_for_lwp (&event_child, &wstat);
733 if (event_child == NULL)
734 error ("event from unknown child");
736 current_inferior = (struct thread_info *)
737 find_inferior_id (&all_threads, event_child->lwpid);
739 /* Check for thread exit. */
740 if (! WIFSTOPPED (wstat))
743 fprintf (stderr, "LWP %ld exiting\n", event_child->head.id);
745 /* If the last thread is exiting, just return. */
746 if (all_threads.head == all_threads.tail)
749 dead_thread_notify (thread_id_to_gdb_id (event_child->lwpid));
751 remove_inferior (&all_lwps, &event_child->head);
753 remove_thread (current_inferior);
754 current_inferior = (struct thread_info *) all_threads.head;
756 /* If we were waiting for this particular child to do something...
757 well, it did something. */
761 /* Wait for a more interesting event. */
765 if (WIFSTOPPED (wstat)
766 && WSTOPSIG (wstat) == SIGSTOP
767 && event_child->stop_expected)
770 fprintf (stderr, "Expected stop.\n");
771 event_child->stop_expected = 0;
772 linux_resume_one_lwp (&event_child->head,
773 event_child->stepping, 0, NULL);
777 if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP
780 handle_extended_wait (event_child, wstat);
784 /* If GDB is not interested in this signal, don't stop other
785 threads, and don't report it to GDB. Just resume the
786 inferior right away. We do this for threading-related
787 signals as well as any that GDB specifically requested we
788 ignore. But never ignore SIGSTOP if we sent it ourselves,
789 and do not ignore signals when stepping - they may require
790 special handling to skip the signal handler. */
791 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
793 if (WIFSTOPPED (wstat)
794 && !event_child->stepping
797 (thread_db_active && (WSTOPSIG (wstat) == __SIGRTMIN
798 || WSTOPSIG (wstat) == __SIGRTMIN + 1))
801 (pass_signals[target_signal_from_host (WSTOPSIG (wstat))]
802 && (WSTOPSIG (wstat) != SIGSTOP || !stopping_threads))))
804 siginfo_t info, *info_p;
807 fprintf (stderr, "Ignored signal %d for LWP %ld.\n",
808 WSTOPSIG (wstat), event_child->head.id);
810 if (ptrace (PTRACE_GETSIGINFO, event_child->lwpid, 0, &info) == 0)
814 linux_resume_one_lwp (&event_child->head,
815 event_child->stepping,
816 WSTOPSIG (wstat), info_p);
820 /* If this event was not handled above, and is not a SIGTRAP, report
822 if (!WIFSTOPPED (wstat) || WSTOPSIG (wstat) != SIGTRAP)
825 /* If this target does not support breakpoints, we simply report the
826 SIGTRAP; it's of no concern to us. */
827 if (the_low_target.get_pc == NULL)
830 stop_pc = get_stop_pc ();
832 /* bp_reinsert will only be set if we were single-stepping.
833 Notice that we will resume the process after hitting
834 a gdbserver breakpoint; single-stepping to/over one
835 is not supported (yet). */
836 if (event_child->bp_reinsert != 0)
839 fprintf (stderr, "Reinserted breakpoint.\n");
840 reinsert_breakpoint (event_child->bp_reinsert);
841 event_child->bp_reinsert = 0;
843 /* Clear the single-stepping flag and SIGTRAP as we resume. */
844 linux_resume_one_lwp (&event_child->head, 0, 0, NULL);
848 bp_status = check_breakpoints (stop_pc);
853 fprintf (stderr, "Hit a gdbserver breakpoint.\n");
855 /* We hit one of our own breakpoints. We mark it as a pending
856 breakpoint, so that check_removed_breakpoint () will do the PC
857 adjustment for us at the appropriate time. */
858 event_child->pending_is_breakpoint = 1;
859 event_child->pending_stop_pc = stop_pc;
861 /* We may need to put the breakpoint back. We continue in the event
862 loop instead of simply replacing the breakpoint right away,
863 in order to not lose signals sent to the thread that hit the
864 breakpoint. Unfortunately this increases the window where another
865 thread could sneak past the removed breakpoint. For the current
866 use of server-side breakpoints (thread creation) this is
867 acceptable; but it needs to be considered before this breakpoint
868 mechanism can be used in more general ways. For some breakpoints
869 it may be necessary to stop all other threads, but that should
870 be avoided where possible.
872 If breakpoint_reinsert_addr is NULL, that means that we can
873 use PTRACE_SINGLESTEP on this platform. Uninsert the breakpoint,
874 mark it for reinsertion, and single-step.
876 Otherwise, call the target function to figure out where we need
877 our temporary breakpoint, create it, and continue executing this
880 /* No need to reinsert. */
881 linux_resume_one_lwp (&event_child->head, 0, 0, NULL);
882 else if (the_low_target.breakpoint_reinsert_addr == NULL)
884 event_child->bp_reinsert = stop_pc;
885 uninsert_breakpoint (stop_pc);
886 linux_resume_one_lwp (&event_child->head, 1, 0, NULL);
890 reinsert_breakpoint_by_bp
891 (stop_pc, (*the_low_target.breakpoint_reinsert_addr) ());
892 linux_resume_one_lwp (&event_child->head, 0, 0, NULL);
899 fprintf (stderr, "Hit a non-gdbserver breakpoint.\n");
901 /* If we were single-stepping, we definitely want to report the
902 SIGTRAP. The single-step operation has completed, so also
903 clear the stepping flag; in general this does not matter,
904 because the SIGTRAP will be reported to the client, which
905 will give us a new action for this thread, but clear it for
906 consistency anyway. It's safe to clear the stepping flag
907 because the only consumer of get_stop_pc () after this point
908 is check_removed_breakpoint, and pending_is_breakpoint is not
909 set. It might be wiser to use a step_completed flag instead. */
910 if (event_child->stepping)
912 event_child->stepping = 0;
916 /* A SIGTRAP that we can't explain. It may have been a breakpoint.
917 Check if it is a breakpoint, and if so mark the process information
918 accordingly. This will handle both the necessary fiddling with the
919 PC on decr_pc_after_break targets and suppressing extra threads
920 hitting a breakpoint if two hit it at once and then GDB removes it
921 after the first is reported. Arguably it would be better to report
922 multiple threads hitting breakpoints simultaneously, but the current
923 remote protocol does not allow this. */
924 if ((*the_low_target.breakpoint_at) (stop_pc))
926 event_child->pending_is_breakpoint = 1;
927 event_child->pending_stop_pc = stop_pc;
937 /* Wait for process, returns status. */
940 linux_wait (char *status)
943 struct thread_info *child = NULL;
946 /* If we were only supposed to resume one thread, only wait for
947 that thread - if it's still alive. If it died, however - which
948 can happen if we're coming from the thread death case below -
949 then we need to make sure we restart the other threads. We could
950 pick a thread at random or restart all; restarting all is less
952 if (cont_thread != 0 && cont_thread != -1)
954 child = (struct thread_info *) find_inferior_id (&all_threads,
957 /* No stepping, no signal - unless one is pending already, of course. */
960 struct thread_resume resume_info;
961 resume_info.thread = -1;
962 resume_info.step = resume_info.sig = resume_info.leave_stopped = 0;
963 linux_resume (&resume_info);
967 w = linux_wait_for_event (child);
970 if (must_set_ptrace_flags)
972 ptrace (PTRACE_SETOPTIONS, inferior_pid, 0, PTRACE_O_TRACECLONE);
973 must_set_ptrace_flags = 0;
976 /* If we are waiting for a particular child, and it exited,
977 linux_wait_for_event will return its exit status. Similarly if
978 the last child exited. If this is not the last child, however,
979 do not report it as exited until there is a 'thread exited' response
980 available in the remote protocol. Instead, just wait for another event.
981 This should be safe, because if the thread crashed we will already
982 have reported the termination signal to GDB; that should stop any
983 in-progress stepping operations, etc.
985 Report the exit status of the last thread to exit. This matches
986 LinuxThreads' behavior. */
988 if (all_threads.head == all_threads.tail)
992 fprintf (stderr, "\nChild exited with retcode = %x \n",
996 free (all_lwps.head);
997 all_lwps.head = all_lwps.tail = NULL;
998 return WEXITSTATUS (w);
1000 else if (!WIFSTOPPED (w))
1002 fprintf (stderr, "\nChild terminated with signal = %x \n",
1006 free (all_lwps.head);
1007 all_lwps.head = all_lwps.tail = NULL;
1008 return target_signal_from_host (WTERMSIG (w));
1013 if (!WIFSTOPPED (w))
1018 return target_signal_from_host (WSTOPSIG (w));
1021 /* Send a signal to an LWP. For LinuxThreads, kill is enough; however, if
1022 thread groups are in use, we need to use tkill. */
1025 kill_lwp (unsigned long lwpid, int signo)
1027 static int tkill_failed;
1034 int ret = syscall (SYS_tkill, lwpid, signo);
1035 if (errno != ENOSYS)
1042 return kill (lwpid, signo);
1046 send_sigstop (struct inferior_list_entry *entry)
1048 struct lwp_info *lwp = (struct lwp_info *) entry;
1053 /* If we already have a pending stop signal for this process, don't
1055 if (lwp->stop_expected)
1058 fprintf (stderr, "Have pending sigstop for lwp %ld\n",
1061 /* We clear the stop_expected flag so that wait_for_sigstop
1062 will receive the SIGSTOP event (instead of silently resuming and
1063 waiting again). It'll be reset below. */
1064 lwp->stop_expected = 0;
1069 fprintf (stderr, "Sending sigstop to lwp %ld\n", lwp->head.id);
1071 kill_lwp (lwp->head.id, SIGSTOP);
1075 wait_for_sigstop (struct inferior_list_entry *entry)
1077 struct lwp_info *lwp = (struct lwp_info *) entry;
1078 struct thread_info *saved_inferior, *thread;
1080 unsigned long saved_tid;
1085 saved_inferior = current_inferior;
1086 saved_tid = ((struct inferior_list_entry *) saved_inferior)->id;
1087 thread = (struct thread_info *) find_inferior_id (&all_threads,
1089 wstat = linux_wait_for_event (thread);
1091 /* If we stopped with a non-SIGSTOP signal, save it for later
1092 and record the pending SIGSTOP. If the process exited, just
1094 if (WIFSTOPPED (wstat)
1095 && WSTOPSIG (wstat) != SIGSTOP)
1098 fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n",
1100 lwp->status_pending_p = 1;
1101 lwp->status_pending = wstat;
1102 lwp->stop_expected = 1;
1105 if (linux_thread_alive (saved_tid))
1106 current_inferior = saved_inferior;
1110 fprintf (stderr, "Previously current thread died.\n");
1112 /* Set a valid thread as current. */
1113 set_desired_inferior (0);
1118 stop_all_lwps (void)
1120 stopping_threads = 1;
1121 for_each_inferior (&all_lwps, send_sigstop);
1122 for_each_inferior (&all_lwps, wait_for_sigstop);
1123 stopping_threads = 0;
1126 /* Resume execution of the inferior process.
1127 If STEP is nonzero, single-step it.
1128 If SIGNAL is nonzero, give it that signal. */
1131 linux_resume_one_lwp (struct inferior_list_entry *entry,
1132 int step, int signal, siginfo_t *info)
1134 struct lwp_info *lwp = (struct lwp_info *) entry;
1135 struct thread_info *saved_inferior;
1137 if (lwp->stopped == 0)
1140 /* If we have pending signals or status, and a new signal, enqueue the
1141 signal. Also enqueue the signal if we are waiting to reinsert a
1142 breakpoint; it will be picked up again below. */
1144 && (lwp->status_pending_p || lwp->pending_signals != NULL
1145 || lwp->bp_reinsert != 0))
1147 struct pending_signals *p_sig;
1148 p_sig = xmalloc (sizeof (*p_sig));
1149 p_sig->prev = lwp->pending_signals;
1150 p_sig->signal = signal;
1152 memset (&p_sig->info, 0, sizeof (siginfo_t));
1154 memcpy (&p_sig->info, info, sizeof (siginfo_t));
1155 lwp->pending_signals = p_sig;
1158 if (lwp->status_pending_p && !check_removed_breakpoint (lwp))
1161 saved_inferior = current_inferior;
1162 current_inferior = get_lwp_thread (lwp);
1165 fprintf (stderr, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
1166 inferior_pid, step ? "step" : "continue", signal,
1167 lwp->stop_expected ? "expected" : "not expected");
1169 /* This bit needs some thinking about. If we get a signal that
1170 we must report while a single-step reinsert is still pending,
1171 we often end up resuming the thread. It might be better to
1172 (ew) allow a stack of pending events; then we could be sure that
1173 the reinsert happened right away and not lose any signals.
1175 Making this stack would also shrink the window in which breakpoints are
1176 uninserted (see comment in linux_wait_for_lwp) but not enough for
1177 complete correctness, so it won't solve that problem. It may be
1178 worthwhile just to solve this one, however. */
1179 if (lwp->bp_reinsert != 0)
1182 fprintf (stderr, " pending reinsert at %08lx", (long)lwp->bp_reinsert);
1184 fprintf (stderr, "BAD - reinserting but not stepping.\n");
1187 /* Postpone any pending signal. It was enqueued above. */
1191 check_removed_breakpoint (lwp);
1193 if (debug_threads && the_low_target.get_pc != NULL)
1195 fprintf (stderr, " ");
1196 (*the_low_target.get_pc) ();
1199 /* If we have pending signals, consume one unless we are trying to reinsert
1201 if (lwp->pending_signals != NULL && lwp->bp_reinsert == 0)
1203 struct pending_signals **p_sig;
1205 p_sig = &lwp->pending_signals;
1206 while ((*p_sig)->prev != NULL)
1207 p_sig = &(*p_sig)->prev;
1209 signal = (*p_sig)->signal;
1210 if ((*p_sig)->info.si_signo != 0)
1211 ptrace (PTRACE_SETSIGINFO, lwp->lwpid, 0, &(*p_sig)->info);
1217 regcache_invalidate_one ((struct inferior_list_entry *)
1218 get_lwp_thread (lwp));
1221 lwp->stepping = step;
1222 ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwp->lwpid, 0, signal);
1224 current_inferior = saved_inferior;
1227 /* ESRCH from ptrace either means that the thread was already
1228 running (an error) or that it is gone (a race condition). If
1229 it's gone, we will get a notification the next time we wait,
1230 so we can ignore the error. We could differentiate these
1231 two, but it's tricky without waiting; the thread still exists
1232 as a zombie, so sending it signal 0 would succeed. So just
1237 perror_with_name ("ptrace");
1241 static struct thread_resume *resume_ptr;
1243 /* This function is called once per thread. We look up the thread
1244 in RESUME_PTR, and mark the thread with a pointer to the appropriate
1247 This algorithm is O(threads * resume elements), but resume elements
1248 is small (and will remain small at least until GDB supports thread
1251 linux_set_resume_request (struct inferior_list_entry *entry)
1253 struct lwp_info *lwp;
1254 struct thread_info *thread;
1257 thread = (struct thread_info *) entry;
1258 lwp = get_thread_lwp (thread);
1261 while (resume_ptr[ndx].thread != -1 && resume_ptr[ndx].thread != entry->id)
1264 lwp->resume = &resume_ptr[ndx];
1267 /* This function is called once per thread. We check the thread's resume
1268 request, which will tell us whether to resume, step, or leave the thread
1269 stopped; and what signal, if any, it should be sent. For threads which
1270 we aren't explicitly told otherwise, we preserve the stepping flag; this
1271 is used for stepping over gdbserver-placed breakpoints. */
1274 linux_continue_one_thread (struct inferior_list_entry *entry)
1276 struct lwp_info *lwp;
1277 struct thread_info *thread;
1280 thread = (struct thread_info *) entry;
1281 lwp = get_thread_lwp (thread);
1283 if (lwp->resume->leave_stopped)
1286 if (lwp->resume->thread == -1)
1287 step = lwp->stepping || lwp->resume->step;
1289 step = lwp->resume->step;
1291 linux_resume_one_lwp (&lwp->head, step, lwp->resume->sig, NULL);
1296 /* This function is called once per thread. We check the thread's resume
1297 request, which will tell us whether to resume, step, or leave the thread
1298 stopped; and what signal, if any, it should be sent. We queue any needed
1299 signals, since we won't actually resume. We already have a pending event
1300 to report, so we don't need to preserve any step requests; they should
1301 be re-issued if necessary. */
1304 linux_queue_one_thread (struct inferior_list_entry *entry)
1306 struct lwp_info *lwp;
1307 struct thread_info *thread;
1309 thread = (struct thread_info *) entry;
1310 lwp = get_thread_lwp (thread);
1312 if (lwp->resume->leave_stopped)
1315 /* If we have a new signal, enqueue the signal. */
1316 if (lwp->resume->sig != 0)
1318 struct pending_signals *p_sig;
1319 p_sig = xmalloc (sizeof (*p_sig));
1320 p_sig->prev = lwp->pending_signals;
1321 p_sig->signal = lwp->resume->sig;
1322 memset (&p_sig->info, 0, sizeof (siginfo_t));
1324 /* If this is the same signal we were previously stopped by,
1325 make sure to queue its siginfo. We can ignore the return
1326 value of ptrace; if it fails, we'll skip
1327 PTRACE_SETSIGINFO. */
1328 if (WIFSTOPPED (lwp->last_status)
1329 && WSTOPSIG (lwp->last_status) == lwp->resume->sig)
1330 ptrace (PTRACE_GETSIGINFO, lwp->lwpid, 0, &p_sig->info);
1332 lwp->pending_signals = p_sig;
1338 /* Set DUMMY if this process has an interesting status pending. */
1340 resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p)
1342 struct lwp_info *lwp = (struct lwp_info *) entry;
1344 /* Processes which will not be resumed are not interesting, because
1345 we might not wait for them next time through linux_wait. */
1346 if (lwp->resume->leave_stopped)
1349 /* If this thread has a removed breakpoint, we won't have any
1350 events to report later, so check now. check_removed_breakpoint
1351 may clear status_pending_p. We avoid calling check_removed_breakpoint
1352 for any thread that we are not otherwise going to resume - this
1353 lets us preserve stopped status when two threads hit a breakpoint.
1354 GDB removes the breakpoint to single-step a particular thread
1355 past it, then re-inserts it and resumes all threads. We want
1356 to report the second thread without resuming it in the interim. */
1357 if (lwp->status_pending_p)
1358 check_removed_breakpoint (lwp);
1360 if (lwp->status_pending_p)
1361 * (int *) flag_p = 1;
1367 linux_resume (struct thread_resume *resume_info)
1371 /* Yes, the use of a global here is rather ugly. */
1372 resume_ptr = resume_info;
1374 for_each_inferior (&all_threads, linux_set_resume_request);
1376 /* If there is a thread which would otherwise be resumed, which
1377 has a pending status, then don't resume any threads - we can just
1378 report the pending status. Make sure to queue any signals
1379 that would otherwise be sent. */
1381 find_inferior (&all_lwps, resume_status_pending_p, &pending_flag);
1386 fprintf (stderr, "Not resuming, pending status\n");
1388 fprintf (stderr, "Resuming, no pending status\n");
1392 for_each_inferior (&all_threads, linux_queue_one_thread);
1394 for_each_inferior (&all_threads, linux_continue_one_thread);
1397 #ifdef HAVE_LINUX_USRREGS
1400 register_addr (int regnum)
1404 if (regnum < 0 || regnum >= the_low_target.num_regs)
1405 error ("Invalid register number %d.", regnum);
1407 addr = the_low_target.regmap[regnum];
1412 /* Fetch one register. */
1414 fetch_register (int regno)
1420 if (regno >= the_low_target.num_regs)
1422 if ((*the_low_target.cannot_fetch_register) (regno))
1425 regaddr = register_addr (regno);
1428 size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
1429 & - sizeof (PTRACE_XFER_TYPE));
1430 buf = alloca (size);
1431 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
1434 *(PTRACE_XFER_TYPE *) (buf + i) =
1435 ptrace (PTRACE_PEEKUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, 0);
1436 regaddr += sizeof (PTRACE_XFER_TYPE);
1439 /* Warning, not error, in case we are attached; sometimes the
1440 kernel doesn't let us at the registers. */
1441 char *err = strerror (errno);
1442 char *msg = alloca (strlen (err) + 128);
1443 sprintf (msg, "reading register %d: %s", regno, err);
1449 if (the_low_target.supply_ptrace_register)
1450 the_low_target.supply_ptrace_register (regno, buf);
1452 supply_register (regno, buf);
1457 /* Fetch all registers, or just one, from the child process. */
1459 usr_fetch_inferior_registers (int regno)
1461 if (regno == -1 || regno == 0)
1462 for (regno = 0; regno < the_low_target.num_regs; regno++)
1463 fetch_register (regno);
1465 fetch_register (regno);
1468 /* Store our register values back into the inferior.
1469 If REGNO is -1, do this for all registers.
1470 Otherwise, REGNO specifies which register (so we can save time). */
1472 usr_store_inferior_registers (int regno)
1480 if (regno >= the_low_target.num_regs)
1483 if ((*the_low_target.cannot_store_register) (regno) == 1)
1486 regaddr = register_addr (regno);
1490 size = (register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
1491 & - sizeof (PTRACE_XFER_TYPE);
1492 buf = alloca (size);
1493 memset (buf, 0, size);
1495 if (the_low_target.collect_ptrace_register)
1496 the_low_target.collect_ptrace_register (regno, buf);
1498 collect_register (regno, buf);
1500 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
1503 ptrace (PTRACE_POKEUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
1504 *(PTRACE_XFER_TYPE *) (buf + i));
1507 /* At this point, ESRCH should mean the process is
1508 already gone, in which case we simply ignore attempts
1509 to change its registers. See also the related
1510 comment in linux_resume_one_lwp. */
1514 if ((*the_low_target.cannot_store_register) (regno) == 0)
1516 char *err = strerror (errno);
1517 char *msg = alloca (strlen (err) + 128);
1518 sprintf (msg, "writing register %d: %s",
1524 regaddr += sizeof (PTRACE_XFER_TYPE);
1528 for (regno = 0; regno < the_low_target.num_regs; regno++)
1529 usr_store_inferior_registers (regno);
1531 #endif /* HAVE_LINUX_USRREGS */
1535 #ifdef HAVE_LINUX_REGSETS
1538 regsets_fetch_inferior_registers ()
1540 struct regset_info *regset;
1541 int saw_general_regs = 0;
1543 regset = target_regsets;
1545 while (regset->size >= 0)
1550 if (regset->size == 0 || disabled_regsets[regset - target_regsets])
1556 buf = xmalloc (regset->size);
1558 res = ptrace (regset->get_request, inferior_pid, 0, buf);
1560 res = ptrace (regset->get_request, inferior_pid, buf, 0);
1566 /* If we get EIO on a regset, do not try it again for
1568 disabled_regsets[regset - target_regsets] = 1;
1574 sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%ld",
1579 else if (regset->type == GENERAL_REGS)
1580 saw_general_regs = 1;
1581 regset->store_function (buf);
1584 if (saw_general_regs)
1591 regsets_store_inferior_registers ()
1593 struct regset_info *regset;
1594 int saw_general_regs = 0;
1596 regset = target_regsets;
1598 while (regset->size >= 0)
1603 if (regset->size == 0 || disabled_regsets[regset - target_regsets])
1609 buf = xmalloc (regset->size);
1611 /* First fill the buffer with the current register set contents,
1612 in case there are any items in the kernel's regset that are
1613 not in gdbserver's regcache. */
1615 res = ptrace (regset->get_request, inferior_pid, 0, buf);
1617 res = ptrace (regset->get_request, inferior_pid, buf, 0);
1622 /* Then overlay our cached registers on that. */
1623 regset->fill_function (buf);
1625 /* Only now do we write the register set. */
1627 res = ptrace (regset->set_request, inferior_pid, 0, buf);
1629 res = ptrace (regset->set_request, inferior_pid, buf, 0);
1637 /* If we get EIO on a regset, do not try it again for
1639 disabled_regsets[regset - target_regsets] = 1;
1642 else if (errno == ESRCH)
1644 /* At this point, ESRCH should mean the process is
1645 already gone, in which case we simply ignore attempts
1646 to change its registers. See also the related
1647 comment in linux_resume_one_lwp. */
1652 perror ("Warning: ptrace(regsets_store_inferior_registers)");
1655 else if (regset->type == GENERAL_REGS)
1656 saw_general_regs = 1;
1660 if (saw_general_regs)
1667 #endif /* HAVE_LINUX_REGSETS */
1671 linux_fetch_registers (int regno)
1673 #ifdef HAVE_LINUX_REGSETS
1674 if (regsets_fetch_inferior_registers () == 0)
1677 #ifdef HAVE_LINUX_USRREGS
1678 usr_fetch_inferior_registers (regno);
1683 linux_store_registers (int regno)
1685 #ifdef HAVE_LINUX_REGSETS
1686 if (regsets_store_inferior_registers () == 0)
1689 #ifdef HAVE_LINUX_USRREGS
1690 usr_store_inferior_registers (regno);
1695 /* Copy LEN bytes from inferior's memory starting at MEMADDR
1696 to debugger memory starting at MYADDR. */
1699 linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
1702 /* Round starting address down to longword boundary. */
1703 register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
1704 /* Round ending address up; get number of longwords that makes. */
1706 = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
1707 / sizeof (PTRACE_XFER_TYPE);
1708 /* Allocate buffer of that many longwords. */
1709 register PTRACE_XFER_TYPE *buffer
1710 = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
1714 /* Try using /proc. Don't bother for one word. */
1715 if (len >= 3 * sizeof (long))
1717 /* We could keep this file open and cache it - possibly one per
1718 thread. That requires some juggling, but is even faster. */
1719 sprintf (filename, "/proc/%ld/mem", inferior_pid);
1720 fd = open (filename, O_RDONLY | O_LARGEFILE);
1724 /* If pread64 is available, use it. It's faster if the kernel
1725 supports it (only one syscall), and it's 64-bit safe even on
1726 32-bit platforms (for instance, SPARC debugging a SPARC64
1729 if (pread64 (fd, myaddr, len, memaddr) != len)
1731 if (lseek (fd, memaddr, SEEK_SET) == -1 || read (fd, memaddr, len) != len)
1743 /* Read all the longwords */
1744 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
1747 buffer[i] = ptrace (PTRACE_PEEKTEXT, inferior_pid,
1748 (PTRACE_ARG3_TYPE) addr, 0);
1753 /* Copy appropriate bytes out of the buffer. */
1755 (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
1761 /* Copy LEN bytes of data from debugger memory at MYADDR
1762 to inferior's memory at MEMADDR.
1763 On failure (cannot write the inferior)
1764 returns the value of errno. */
1767 linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
1770 /* Round starting address down to longword boundary. */
1771 register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
1772 /* Round ending address up; get number of longwords that makes. */
1774 = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) / sizeof (PTRACE_XFER_TYPE);
1775 /* Allocate buffer of that many longwords. */
1776 register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
1780 fprintf (stderr, "Writing %02x to %08lx\n", (unsigned)myaddr[0], (long)memaddr);
1783 /* Fill start and end extra bytes of buffer with existing memory data. */
1785 buffer[0] = ptrace (PTRACE_PEEKTEXT, inferior_pid,
1786 (PTRACE_ARG3_TYPE) addr, 0);
1791 = ptrace (PTRACE_PEEKTEXT, inferior_pid,
1792 (PTRACE_ARG3_TYPE) (addr + (count - 1)
1793 * sizeof (PTRACE_XFER_TYPE)),
1797 /* Copy data to be written over corresponding part of buffer */
1799 memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), myaddr, len);
1801 /* Write the entire buffer. */
1803 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
1806 ptrace (PTRACE_POKETEXT, inferior_pid, (PTRACE_ARG3_TYPE) addr, buffer[i]);
1814 static int linux_supports_tracefork_flag;
1816 /* Helper functions for linux_test_for_tracefork, called via clone (). */
1819 linux_tracefork_grandchild (void *arg)
1824 #define STACK_SIZE 4096
1827 linux_tracefork_child (void *arg)
1829 ptrace (PTRACE_TRACEME, 0, 0, 0);
1830 kill (getpid (), SIGSTOP);
1832 __clone2 (linux_tracefork_grandchild, arg, STACK_SIZE,
1833 CLONE_VM | SIGCHLD, NULL);
1835 clone (linux_tracefork_grandchild, arg + STACK_SIZE,
1836 CLONE_VM | SIGCHLD, NULL);
1841 /* Wrapper function for waitpid which handles EINTR. */
1844 my_waitpid (int pid, int *status, int flags)
1849 ret = waitpid (pid, status, flags);
1851 while (ret == -1 && errno == EINTR);
1856 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
1857 sure that we can enable the option, and that it had the desired
1861 linux_test_for_tracefork (void)
1863 int child_pid, ret, status;
1865 char *stack = xmalloc (STACK_SIZE * 4);
1867 linux_supports_tracefork_flag = 0;
1869 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
1871 child_pid = __clone2 (linux_tracefork_child, stack, STACK_SIZE,
1872 CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
1874 child_pid = clone (linux_tracefork_child, stack + STACK_SIZE,
1875 CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
1877 if (child_pid == -1)
1878 perror_with_name ("clone");
1880 ret = my_waitpid (child_pid, &status, 0);
1882 perror_with_name ("waitpid");
1883 else if (ret != child_pid)
1884 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret);
1885 if (! WIFSTOPPED (status))
1886 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status);
1888 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK);
1891 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
1894 warning ("linux_test_for_tracefork: failed to kill child");
1898 ret = my_waitpid (child_pid, &status, 0);
1899 if (ret != child_pid)
1900 warning ("linux_test_for_tracefork: failed to wait for killed child");
1901 else if (!WIFSIGNALED (status))
1902 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
1903 "killed child", status);
1908 ret = ptrace (PTRACE_CONT, child_pid, 0, 0);
1910 warning ("linux_test_for_tracefork: failed to resume child");
1912 ret = my_waitpid (child_pid, &status, 0);
1914 if (ret == child_pid && WIFSTOPPED (status)
1915 && status >> 16 == PTRACE_EVENT_FORK)
1918 ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
1919 if (ret == 0 && second_pid != 0)
1923 linux_supports_tracefork_flag = 1;
1924 my_waitpid (second_pid, &second_status, 0);
1925 ret = ptrace (PTRACE_KILL, second_pid, 0, 0);
1927 warning ("linux_test_for_tracefork: failed to kill second child");
1928 my_waitpid (second_pid, &status, 0);
1932 warning ("linux_test_for_tracefork: unexpected result from waitpid "
1933 "(%d, status 0x%x)", ret, status);
1937 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
1939 warning ("linux_test_for_tracefork: failed to kill child");
1940 my_waitpid (child_pid, &status, 0);
1942 while (WIFSTOPPED (status));
1949 linux_look_up_symbols (void)
1951 #ifdef USE_THREAD_DB
1952 if (thread_db_active)
1955 thread_db_active = thread_db_init (!linux_supports_tracefork_flag);
1960 linux_request_interrupt (void)
1962 extern unsigned long signal_pid;
1964 if (cont_thread != 0 && cont_thread != -1)
1966 struct lwp_info *lwp;
1968 lwp = get_thread_lwp (current_inferior);
1969 kill_lwp (lwp->lwpid, SIGINT);
1972 kill_lwp (signal_pid, SIGINT);
1975 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
1976 to debugger memory starting at MYADDR. */
1979 linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len)
1981 char filename[PATH_MAX];
1984 snprintf (filename, sizeof filename, "/proc/%ld/auxv", inferior_pid);
1986 fd = open (filename, O_RDONLY);
1990 if (offset != (CORE_ADDR) 0
1991 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
1994 n = read (fd, myaddr, len);
2001 /* These watchpoint related wrapper functions simply pass on the function call
2002 if the target has registered a corresponding function. */
2005 linux_insert_watchpoint (char type, CORE_ADDR addr, int len)
2007 if (the_low_target.insert_watchpoint != NULL)
2008 return the_low_target.insert_watchpoint (type, addr, len);
2010 /* Unsupported (see target.h). */
2015 linux_remove_watchpoint (char type, CORE_ADDR addr, int len)
2017 if (the_low_target.remove_watchpoint != NULL)
2018 return the_low_target.remove_watchpoint (type, addr, len);
2020 /* Unsupported (see target.h). */
2025 linux_stopped_by_watchpoint (void)
2027 if (the_low_target.stopped_by_watchpoint != NULL)
2028 return the_low_target.stopped_by_watchpoint ();
2034 linux_stopped_data_address (void)
2036 if (the_low_target.stopped_data_address != NULL)
2037 return the_low_target.stopped_data_address ();
2042 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
2043 #if defined(__mcoldfire__)
2044 /* These should really be defined in the kernel's ptrace.h header. */
2045 #define PT_TEXT_ADDR 49*4
2046 #define PT_DATA_ADDR 50*4
2047 #define PT_TEXT_END_ADDR 51*4
2050 /* Under uClinux, programs are loaded at non-zero offsets, which we need
2051 to tell gdb about. */
2054 linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p)
2056 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
2057 unsigned long text, text_end, data;
2058 int pid = get_thread_lwp (current_inferior)->head.id;
2062 text = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_ADDR, 0);
2063 text_end = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_END_ADDR, 0);
2064 data = ptrace (PTRACE_PEEKUSER, pid, (long)PT_DATA_ADDR, 0);
2068 /* Both text and data offsets produced at compile-time (and so
2069 used by gdb) are relative to the beginning of the program,
2070 with the data segment immediately following the text segment.
2071 However, the actual runtime layout in memory may put the data
2072 somewhere else, so when we send gdb a data base-address, we
2073 use the real data base address and subtract the compile-time
2074 data base-address from it (which is just the length of the
2075 text segment). BSS immediately follows data in both
2078 *data_p = data - (text_end - text);
2088 linux_qxfer_osdata (const char *annex,
2089 unsigned char *readbuf, unsigned const char *writebuf,
2090 CORE_ADDR offset, int len)
2092 /* We make the process list snapshot when the object starts to be
2094 static const char *buf;
2095 static long len_avail = -1;
2096 static struct buffer buffer;
2100 if (strcmp (annex, "processes") != 0)
2103 if (!readbuf || writebuf)
2108 if (len_avail != -1 && len_avail != 0)
2109 buffer_free (&buffer);
2112 buffer_init (&buffer);
2113 buffer_grow_str (&buffer, "<osdata type=\"processes\">");
2115 dirp = opendir ("/proc");
2119 while ((dp = readdir (dirp)) != NULL)
2121 struct stat statbuf;
2122 char procentry[sizeof ("/proc/4294967295")];
2124 if (!isdigit (dp->d_name[0])
2125 || strlen (dp->d_name) > sizeof ("4294967295") - 1)
2128 sprintf (procentry, "/proc/%s", dp->d_name);
2129 if (stat (procentry, &statbuf) == 0
2130 && S_ISDIR (statbuf.st_mode))
2134 char cmd[MAXPATHLEN + 1];
2135 struct passwd *entry;
2137 sprintf (pathname, "/proc/%s/cmdline", dp->d_name);
2138 entry = getpwuid (statbuf.st_uid);
2140 if ((f = fopen (pathname, "r")) != NULL)
2142 size_t len = fread (cmd, 1, sizeof (cmd) - 1, f);
2146 for (i = 0; i < len; i++)
2154 "<column name=\"pid\">%s</column>"
2155 "<column name=\"user\">%s</column>"
2156 "<column name=\"command\">%s</column>"
2159 entry ? entry->pw_name : "?",
2169 buffer_grow_str0 (&buffer, "</osdata>\n");
2170 buf = buffer_finish (&buffer);
2171 len_avail = strlen (buf);
2174 if (offset >= len_avail)
2176 /* Done. Get rid of the data. */
2177 buffer_free (&buffer);
2183 if (len > len_avail - offset)
2184 len = len_avail - offset;
2185 memcpy (readbuf, buf + offset, len);
2191 linux_xfer_siginfo (const char *annex, unsigned char *readbuf,
2192 unsigned const char *writebuf, CORE_ADDR offset, int len)
2194 struct siginfo siginfo;
2197 if (current_inferior == NULL)
2200 pid = pid_of (get_thread_lwp (current_inferior));
2203 fprintf (stderr, "%s siginfo for lwp %ld.\n",
2204 readbuf != NULL ? "Reading" : "Writing",
2207 if (offset > sizeof (siginfo))
2210 if (ptrace (PTRACE_GETSIGINFO, pid, 0, &siginfo) != 0)
2213 if (offset + len > sizeof (siginfo))
2214 len = sizeof (siginfo) - offset;
2216 if (readbuf != NULL)
2217 memcpy (readbuf, (char *) &siginfo + offset, len);
2220 memcpy ((char *) &siginfo + offset, writebuf, len);
2221 if (ptrace (PTRACE_SETSIGINFO, pid, 0, &siginfo) != 0)
2228 static struct target_ops linux_target_ops = {
2229 linux_create_inferior,
2237 linux_fetch_registers,
2238 linux_store_registers,
2241 linux_look_up_symbols,
2242 linux_request_interrupt,
2244 linux_insert_watchpoint,
2245 linux_remove_watchpoint,
2246 linux_stopped_by_watchpoint,
2247 linux_stopped_data_address,
2248 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
2253 #ifdef USE_THREAD_DB
2254 thread_db_get_tls_address,
2259 hostio_last_error_from_errno,
2265 linux_init_signals ()
2267 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
2268 to find what the cancel signal actually is. */
2269 signal (__SIGRTMIN+1, SIG_IGN);
2273 initialize_low (void)
2275 thread_db_active = 0;
2276 set_target_ops (&linux_target_ops);
2277 set_breakpoint_data (the_low_target.breakpoint,
2278 the_low_target.breakpoint_len);
2279 linux_init_signals ();
2280 linux_test_for_tracefork ();
2281 #ifdef HAVE_LINUX_REGSETS
2282 for (num_regsets = 0; target_regsets[num_regsets].size >= 0; num_regsets++)
2284 disabled_regsets = xmalloc (num_regsets);