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 (char *status
)
936 struct thread_info
*child
= NULL
;
939 /* If we were only supposed to resume one thread, only wait for
940 that thread - if it's still alive. If it died, however - which
941 can happen if we're coming from the thread death case below -
942 then we need to make sure we restart the other threads. We could
943 pick a thread at random or restart all; restarting all is less
945 if (cont_thread
!= 0 && cont_thread
!= -1)
947 child
= (struct thread_info
*) find_inferior_id (&all_threads
,
950 /* No stepping, no signal - unless one is pending already, of course. */
953 struct thread_resume resume_info
;
954 resume_info
.thread
= -1;
955 resume_info
.step
= resume_info
.sig
= 0;
956 linux_resume (&resume_info
, 1);
960 w
= linux_wait_for_event (child
);
963 if (must_set_ptrace_flags
)
965 ptrace (PTRACE_SETOPTIONS
, inferior_pid
, 0, PTRACE_O_TRACECLONE
);
966 must_set_ptrace_flags
= 0;
969 /* If we are waiting for a particular child, and it exited,
970 linux_wait_for_event will return its exit status. Similarly if
971 the last child exited. If this is not the last child, however,
972 do not report it as exited until there is a 'thread exited' response
973 available in the remote protocol. Instead, just wait for another event.
974 This should be safe, because if the thread crashed we will already
975 have reported the termination signal to GDB; that should stop any
976 in-progress stepping operations, etc.
978 Report the exit status of the last thread to exit. This matches
979 LinuxThreads' behavior. */
981 if (all_threads
.head
== all_threads
.tail
)
985 fprintf (stderr
, "\nChild exited with retcode = %x \n",
989 free (all_lwps
.head
);
990 all_lwps
.head
= all_lwps
.tail
= NULL
;
991 return WEXITSTATUS (w
);
993 else if (!WIFSTOPPED (w
))
995 fprintf (stderr
, "\nChild terminated with signal = %x \n",
999 free (all_lwps
.head
);
1000 all_lwps
.head
= all_lwps
.tail
= NULL
;
1001 return target_signal_from_host (WTERMSIG (w
));
1006 if (!WIFSTOPPED (w
))
1011 return target_signal_from_host (WSTOPSIG (w
));
1014 /* Send a signal to an LWP. For LinuxThreads, kill is enough; however, if
1015 thread groups are in use, we need to use tkill. */
1018 kill_lwp (unsigned long lwpid
, int signo
)
1020 static int tkill_failed
;
1027 int ret
= syscall (SYS_tkill
, lwpid
, signo
);
1028 if (errno
!= ENOSYS
)
1035 return kill (lwpid
, signo
);
1039 send_sigstop (struct inferior_list_entry
*entry
)
1041 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1046 /* If we already have a pending stop signal for this process, don't
1048 if (lwp
->stop_expected
)
1051 fprintf (stderr
, "Have pending sigstop for lwp %ld\n",
1054 /* We clear the stop_expected flag so that wait_for_sigstop
1055 will receive the SIGSTOP event (instead of silently resuming and
1056 waiting again). It'll be reset below. */
1057 lwp
->stop_expected
= 0;
1062 fprintf (stderr
, "Sending sigstop to lwp %ld\n", lwp
->head
.id
);
1064 kill_lwp (lwp
->head
.id
, SIGSTOP
);
1068 wait_for_sigstop (struct inferior_list_entry
*entry
)
1070 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1071 struct thread_info
*saved_inferior
, *thread
;
1073 unsigned long saved_tid
;
1078 saved_inferior
= current_inferior
;
1079 saved_tid
= ((struct inferior_list_entry
*) saved_inferior
)->id
;
1080 thread
= (struct thread_info
*) find_inferior_id (&all_threads
,
1082 wstat
= linux_wait_for_event (thread
);
1084 /* If we stopped with a non-SIGSTOP signal, save it for later
1085 and record the pending SIGSTOP. If the process exited, just
1087 if (WIFSTOPPED (wstat
)
1088 && WSTOPSIG (wstat
) != SIGSTOP
)
1091 fprintf (stderr
, "LWP %ld stopped with non-sigstop status %06x\n",
1094 /* Do not leave a pending single-step finish to be reported to
1095 the client. The client will give us a new action for this
1096 thread, possibly a continue request --- otherwise, the client
1097 would consider this pending SIGTRAP reported later a spurious
1099 if (WSTOPSIG (wstat
) == SIGTRAP
1101 && !linux_stopped_by_watchpoint ())
1104 fprintf (stderr
, " single-step SIGTRAP ignored\n");
1108 lwp
->status_pending_p
= 1;
1109 lwp
->status_pending
= wstat
;
1111 lwp
->stop_expected
= 1;
1114 if (linux_thread_alive (saved_tid
))
1115 current_inferior
= saved_inferior
;
1119 fprintf (stderr
, "Previously current thread died.\n");
1121 /* Set a valid thread as current. */
1122 set_desired_inferior (0);
1127 stop_all_lwps (void)
1129 stopping_threads
= 1;
1130 for_each_inferior (&all_lwps
, send_sigstop
);
1131 for_each_inferior (&all_lwps
, wait_for_sigstop
);
1132 stopping_threads
= 0;
1135 /* Resume execution of the inferior process.
1136 If STEP is nonzero, single-step it.
1137 If SIGNAL is nonzero, give it that signal. */
1140 linux_resume_one_lwp (struct inferior_list_entry
*entry
,
1141 int step
, int signal
, siginfo_t
*info
)
1143 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1144 struct thread_info
*saved_inferior
;
1146 if (lwp
->stopped
== 0)
1149 /* If we have pending signals or status, and a new signal, enqueue the
1150 signal. Also enqueue the signal if we are waiting to reinsert a
1151 breakpoint; it will be picked up again below. */
1153 && (lwp
->status_pending_p
|| lwp
->pending_signals
!= NULL
1154 || lwp
->bp_reinsert
!= 0))
1156 struct pending_signals
*p_sig
;
1157 p_sig
= xmalloc (sizeof (*p_sig
));
1158 p_sig
->prev
= lwp
->pending_signals
;
1159 p_sig
->signal
= signal
;
1161 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
1163 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
1164 lwp
->pending_signals
= p_sig
;
1167 if (lwp
->status_pending_p
&& !check_removed_breakpoint (lwp
))
1170 saved_inferior
= current_inferior
;
1171 current_inferior
= get_lwp_thread (lwp
);
1174 fprintf (stderr
, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
1175 inferior_pid
, step
? "step" : "continue", signal
,
1176 lwp
->stop_expected
? "expected" : "not expected");
1178 /* This bit needs some thinking about. If we get a signal that
1179 we must report while a single-step reinsert is still pending,
1180 we often end up resuming the thread. It might be better to
1181 (ew) allow a stack of pending events; then we could be sure that
1182 the reinsert happened right away and not lose any signals.
1184 Making this stack would also shrink the window in which breakpoints are
1185 uninserted (see comment in linux_wait_for_lwp) but not enough for
1186 complete correctness, so it won't solve that problem. It may be
1187 worthwhile just to solve this one, however. */
1188 if (lwp
->bp_reinsert
!= 0)
1191 fprintf (stderr
, " pending reinsert at %08lx", (long)lwp
->bp_reinsert
);
1193 fprintf (stderr
, "BAD - reinserting but not stepping.\n");
1196 /* Postpone any pending signal. It was enqueued above. */
1200 check_removed_breakpoint (lwp
);
1202 if (debug_threads
&& the_low_target
.get_pc
!= NULL
)
1204 fprintf (stderr
, " ");
1205 (*the_low_target
.get_pc
) ();
1208 /* If we have pending signals, consume one unless we are trying to reinsert
1210 if (lwp
->pending_signals
!= NULL
&& lwp
->bp_reinsert
== 0)
1212 struct pending_signals
**p_sig
;
1214 p_sig
= &lwp
->pending_signals
;
1215 while ((*p_sig
)->prev
!= NULL
)
1216 p_sig
= &(*p_sig
)->prev
;
1218 signal
= (*p_sig
)->signal
;
1219 if ((*p_sig
)->info
.si_signo
!= 0)
1220 ptrace (PTRACE_SETSIGINFO
, lwp
->lwpid
, 0, &(*p_sig
)->info
);
1226 regcache_invalidate_one ((struct inferior_list_entry
*)
1227 get_lwp_thread (lwp
));
1230 lwp
->stepping
= step
;
1231 ptrace (step
? PTRACE_SINGLESTEP
: PTRACE_CONT
, lwp
->lwpid
, 0, signal
);
1233 current_inferior
= saved_inferior
;
1236 /* ESRCH from ptrace either means that the thread was already
1237 running (an error) or that it is gone (a race condition). If
1238 it's gone, we will get a notification the next time we wait,
1239 so we can ignore the error. We could differentiate these
1240 two, but it's tricky without waiting; the thread still exists
1241 as a zombie, so sending it signal 0 would succeed. So just
1246 perror_with_name ("ptrace");
1250 struct thread_resume_array
1252 struct thread_resume
*resume
;
1256 /* This function is called once per thread. We look up the thread
1257 in RESUME_PTR, and mark the thread with a pointer to the appropriate
1260 This algorithm is O(threads * resume elements), but resume elements
1261 is small (and will remain small at least until GDB supports thread
1264 linux_set_resume_request (struct inferior_list_entry
*entry
, void *arg
)
1266 struct lwp_info
*lwp
;
1267 struct thread_info
*thread
;
1269 struct thread_resume_array
*r
;
1271 thread
= (struct thread_info
*) entry
;
1272 lwp
= get_thread_lwp (thread
);
1275 for (ndx
= 0; ndx
< r
->n
; ndx
++)
1276 if (r
->resume
[ndx
].thread
== -1 || r
->resume
[ndx
].thread
== entry
->id
)
1278 lwp
->resume
= &r
->resume
[ndx
];
1282 /* No resume action for this thread. */
1288 /* This function is called once per thread. We check the thread's resume
1289 request, which will tell us whether to resume, step, or leave the thread
1290 stopped; and what signal, if any, it should be sent. For threads which
1291 we aren't explicitly told otherwise, we preserve the stepping flag; this
1292 is used for stepping over gdbserver-placed breakpoints. */
1295 linux_continue_one_thread (struct inferior_list_entry
*entry
)
1297 struct lwp_info
*lwp
;
1298 struct thread_info
*thread
;
1301 thread
= (struct thread_info
*) entry
;
1302 lwp
= get_thread_lwp (thread
);
1304 if (lwp
->resume
== NULL
)
1307 if (lwp
->resume
->thread
== -1
1309 && lwp
->pending_is_breakpoint
)
1312 step
= lwp
->resume
->step
;
1314 linux_resume_one_lwp (&lwp
->head
, step
, lwp
->resume
->sig
, NULL
);
1319 /* This function is called once per thread. We check the thread's resume
1320 request, which will tell us whether to resume, step, or leave the thread
1321 stopped; and what signal, if any, it should be sent. We queue any needed
1322 signals, since we won't actually resume. We already have a pending event
1323 to report, so we don't need to preserve any step requests; they should
1324 be re-issued if necessary. */
1327 linux_queue_one_thread (struct inferior_list_entry
*entry
)
1329 struct lwp_info
*lwp
;
1330 struct thread_info
*thread
;
1332 thread
= (struct thread_info
*) entry
;
1333 lwp
= get_thread_lwp (thread
);
1335 if (lwp
->resume
== NULL
)
1338 /* If we have a new signal, enqueue the signal. */
1339 if (lwp
->resume
->sig
!= 0)
1341 struct pending_signals
*p_sig
;
1342 p_sig
= xmalloc (sizeof (*p_sig
));
1343 p_sig
->prev
= lwp
->pending_signals
;
1344 p_sig
->signal
= lwp
->resume
->sig
;
1345 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
1347 /* If this is the same signal we were previously stopped by,
1348 make sure to queue its siginfo. We can ignore the return
1349 value of ptrace; if it fails, we'll skip
1350 PTRACE_SETSIGINFO. */
1351 if (WIFSTOPPED (lwp
->last_status
)
1352 && WSTOPSIG (lwp
->last_status
) == lwp
->resume
->sig
)
1353 ptrace (PTRACE_GETSIGINFO
, lwp
->lwpid
, 0, &p_sig
->info
);
1355 lwp
->pending_signals
= p_sig
;
1361 /* Set DUMMY if this process has an interesting status pending. */
1363 resume_status_pending_p (struct inferior_list_entry
*entry
, void *flag_p
)
1365 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1367 /* Processes which will not be resumed are not interesting, because
1368 we might not wait for them next time through linux_wait. */
1369 if (lwp
->resume
== NULL
)
1372 /* If this thread has a removed breakpoint, we won't have any
1373 events to report later, so check now. check_removed_breakpoint
1374 may clear status_pending_p. We avoid calling check_removed_breakpoint
1375 for any thread that we are not otherwise going to resume - this
1376 lets us preserve stopped status when two threads hit a breakpoint.
1377 GDB removes the breakpoint to single-step a particular thread
1378 past it, then re-inserts it and resumes all threads. We want
1379 to report the second thread without resuming it in the interim. */
1380 if (lwp
->status_pending_p
)
1381 check_removed_breakpoint (lwp
);
1383 if (lwp
->status_pending_p
)
1384 * (int *) flag_p
= 1;
1390 linux_resume (struct thread_resume
*resume_info
, size_t n
)
1393 struct thread_resume_array array
= { resume_info
, n
};
1395 find_inferior (&all_threads
, linux_set_resume_request
, &array
);
1397 /* If there is a thread which would otherwise be resumed, which
1398 has a pending status, then don't resume any threads - we can just
1399 report the pending status. Make sure to queue any signals
1400 that would otherwise be sent. */
1402 find_inferior (&all_lwps
, resume_status_pending_p
, &pending_flag
);
1407 fprintf (stderr
, "Not resuming, pending status\n");
1409 fprintf (stderr
, "Resuming, no pending status\n");
1413 for_each_inferior (&all_threads
, linux_queue_one_thread
);
1415 for_each_inferior (&all_threads
, linux_continue_one_thread
);
1418 #ifdef HAVE_LINUX_USRREGS
1421 register_addr (int regnum
)
1425 if (regnum
< 0 || regnum
>= the_low_target
.num_regs
)
1426 error ("Invalid register number %d.", regnum
);
1428 addr
= the_low_target
.regmap
[regnum
];
1433 /* Fetch one register. */
1435 fetch_register (int regno
)
1441 if (regno
>= the_low_target
.num_regs
)
1443 if ((*the_low_target
.cannot_fetch_register
) (regno
))
1446 regaddr
= register_addr (regno
);
1449 size
= ((register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
1450 & - sizeof (PTRACE_XFER_TYPE
));
1451 buf
= alloca (size
);
1452 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
1455 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
1456 ptrace (PTRACE_PEEKUSER
, inferior_pid
, (PTRACE_ARG3_TYPE
) regaddr
, 0);
1457 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
1460 /* Warning, not error, in case we are attached; sometimes the
1461 kernel doesn't let us at the registers. */
1462 char *err
= strerror (errno
);
1463 char *msg
= alloca (strlen (err
) + 128);
1464 sprintf (msg
, "reading register %d: %s", regno
, err
);
1470 if (the_low_target
.supply_ptrace_register
)
1471 the_low_target
.supply_ptrace_register (regno
, buf
);
1473 supply_register (regno
, buf
);
1478 /* Fetch all registers, or just one, from the child process. */
1480 usr_fetch_inferior_registers (int regno
)
1482 if (regno
== -1 || regno
== 0)
1483 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
1484 fetch_register (regno
);
1486 fetch_register (regno
);
1489 /* Store our register values back into the inferior.
1490 If REGNO is -1, do this for all registers.
1491 Otherwise, REGNO specifies which register (so we can save time). */
1493 usr_store_inferior_registers (int regno
)
1501 if (regno
>= the_low_target
.num_regs
)
1504 if ((*the_low_target
.cannot_store_register
) (regno
) == 1)
1507 regaddr
= register_addr (regno
);
1511 size
= (register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
1512 & - sizeof (PTRACE_XFER_TYPE
);
1513 buf
= alloca (size
);
1514 memset (buf
, 0, size
);
1516 if (the_low_target
.collect_ptrace_register
)
1517 the_low_target
.collect_ptrace_register (regno
, buf
);
1519 collect_register (regno
, buf
);
1521 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
1524 ptrace (PTRACE_POKEUSER
, inferior_pid
, (PTRACE_ARG3_TYPE
) regaddr
,
1525 *(PTRACE_XFER_TYPE
*) (buf
+ i
));
1528 /* At this point, ESRCH should mean the process is
1529 already gone, in which case we simply ignore attempts
1530 to change its registers. See also the related
1531 comment in linux_resume_one_lwp. */
1535 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
1537 char *err
= strerror (errno
);
1538 char *msg
= alloca (strlen (err
) + 128);
1539 sprintf (msg
, "writing register %d: %s",
1545 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
1549 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
1550 usr_store_inferior_registers (regno
);
1552 #endif /* HAVE_LINUX_USRREGS */
1556 #ifdef HAVE_LINUX_REGSETS
1559 regsets_fetch_inferior_registers ()
1561 struct regset_info
*regset
;
1562 int saw_general_regs
= 0;
1564 regset
= target_regsets
;
1566 while (regset
->size
>= 0)
1571 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
1577 buf
= xmalloc (regset
->size
);
1579 res
= ptrace (regset
->get_request
, inferior_pid
, 0, buf
);
1581 res
= ptrace (regset
->get_request
, inferior_pid
, buf
, 0);
1587 /* If we get EIO on a regset, do not try it again for
1589 disabled_regsets
[regset
- target_regsets
] = 1;
1595 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%ld",
1600 else if (regset
->type
== GENERAL_REGS
)
1601 saw_general_regs
= 1;
1602 regset
->store_function (buf
);
1605 if (saw_general_regs
)
1612 regsets_store_inferior_registers ()
1614 struct regset_info
*regset
;
1615 int saw_general_regs
= 0;
1617 regset
= target_regsets
;
1619 while (regset
->size
>= 0)
1624 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
1630 buf
= xmalloc (regset
->size
);
1632 /* First fill the buffer with the current register set contents,
1633 in case there are any items in the kernel's regset that are
1634 not in gdbserver's regcache. */
1636 res
= ptrace (regset
->get_request
, inferior_pid
, 0, buf
);
1638 res
= ptrace (regset
->get_request
, inferior_pid
, buf
, 0);
1643 /* Then overlay our cached registers on that. */
1644 regset
->fill_function (buf
);
1646 /* Only now do we write the register set. */
1648 res
= ptrace (regset
->set_request
, inferior_pid
, 0, buf
);
1650 res
= ptrace (regset
->set_request
, inferior_pid
, buf
, 0);
1658 /* If we get EIO on a regset, do not try it again for
1660 disabled_regsets
[regset
- target_regsets
] = 1;
1663 else if (errno
== ESRCH
)
1665 /* At this point, ESRCH should mean the process is
1666 already gone, in which case we simply ignore attempts
1667 to change its registers. See also the related
1668 comment in linux_resume_one_lwp. */
1673 perror ("Warning: ptrace(regsets_store_inferior_registers)");
1676 else if (regset
->type
== GENERAL_REGS
)
1677 saw_general_regs
= 1;
1681 if (saw_general_regs
)
1688 #endif /* HAVE_LINUX_REGSETS */
1692 linux_fetch_registers (int regno
)
1694 #ifdef HAVE_LINUX_REGSETS
1695 if (regsets_fetch_inferior_registers () == 0)
1698 #ifdef HAVE_LINUX_USRREGS
1699 usr_fetch_inferior_registers (regno
);
1704 linux_store_registers (int regno
)
1706 #ifdef HAVE_LINUX_REGSETS
1707 if (regsets_store_inferior_registers () == 0)
1710 #ifdef HAVE_LINUX_USRREGS
1711 usr_store_inferior_registers (regno
);
1716 /* Copy LEN bytes from inferior's memory starting at MEMADDR
1717 to debugger memory starting at MYADDR. */
1720 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
1723 /* Round starting address down to longword boundary. */
1724 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
1725 /* Round ending address up; get number of longwords that makes. */
1727 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
1728 / sizeof (PTRACE_XFER_TYPE
);
1729 /* Allocate buffer of that many longwords. */
1730 register PTRACE_XFER_TYPE
*buffer
1731 = (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
1735 /* Try using /proc. Don't bother for one word. */
1736 if (len
>= 3 * sizeof (long))
1738 /* We could keep this file open and cache it - possibly one per
1739 thread. That requires some juggling, but is even faster. */
1740 sprintf (filename
, "/proc/%ld/mem", inferior_pid
);
1741 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
1745 /* If pread64 is available, use it. It's faster if the kernel
1746 supports it (only one syscall), and it's 64-bit safe even on
1747 32-bit platforms (for instance, SPARC debugging a SPARC64
1750 if (pread64 (fd
, myaddr
, len
, memaddr
) != len
)
1752 if (lseek (fd
, memaddr
, SEEK_SET
) == -1 || read (fd
, memaddr
, len
) != len
)
1764 /* Read all the longwords */
1765 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
1768 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, inferior_pid
,
1769 (PTRACE_ARG3_TYPE
) addr
, 0);
1774 /* Copy appropriate bytes out of the buffer. */
1776 (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
1782 /* Copy LEN bytes of data from debugger memory at MYADDR
1783 to inferior's memory at MEMADDR.
1784 On failure (cannot write the inferior)
1785 returns the value of errno. */
1788 linux_write_memory (CORE_ADDR memaddr
, const unsigned char *myaddr
, int len
)
1791 /* Round starting address down to longword boundary. */
1792 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
1793 /* Round ending address up; get number of longwords that makes. */
1795 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1) / sizeof (PTRACE_XFER_TYPE
);
1796 /* Allocate buffer of that many longwords. */
1797 register PTRACE_XFER_TYPE
*buffer
= (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
1801 fprintf (stderr
, "Writing %02x to %08lx\n", (unsigned)myaddr
[0], (long)memaddr
);
1804 /* Fill start and end extra bytes of buffer with existing memory data. */
1806 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, inferior_pid
,
1807 (PTRACE_ARG3_TYPE
) addr
, 0);
1812 = ptrace (PTRACE_PEEKTEXT
, inferior_pid
,
1813 (PTRACE_ARG3_TYPE
) (addr
+ (count
- 1)
1814 * sizeof (PTRACE_XFER_TYPE
)),
1818 /* Copy data to be written over corresponding part of buffer */
1820 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)), myaddr
, len
);
1822 /* Write the entire buffer. */
1824 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
1827 ptrace (PTRACE_POKETEXT
, inferior_pid
, (PTRACE_ARG3_TYPE
) addr
, buffer
[i
]);
1835 static int linux_supports_tracefork_flag
;
1837 /* Helper functions for linux_test_for_tracefork, called via clone (). */
1840 linux_tracefork_grandchild (void *arg
)
1845 #define STACK_SIZE 4096
1848 linux_tracefork_child (void *arg
)
1850 ptrace (PTRACE_TRACEME
, 0, 0, 0);
1851 kill (getpid (), SIGSTOP
);
1853 __clone2 (linux_tracefork_grandchild
, arg
, STACK_SIZE
,
1854 CLONE_VM
| SIGCHLD
, NULL
);
1856 clone (linux_tracefork_grandchild
, arg
+ STACK_SIZE
,
1857 CLONE_VM
| SIGCHLD
, NULL
);
1862 /* Wrapper function for waitpid which handles EINTR. */
1865 my_waitpid (int pid
, int *status
, int flags
)
1870 ret
= waitpid (pid
, status
, flags
);
1872 while (ret
== -1 && errno
== EINTR
);
1877 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
1878 sure that we can enable the option, and that it had the desired
1882 linux_test_for_tracefork (void)
1884 int child_pid
, ret
, status
;
1886 char *stack
= xmalloc (STACK_SIZE
* 4);
1888 linux_supports_tracefork_flag
= 0;
1890 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
1892 child_pid
= __clone2 (linux_tracefork_child
, stack
, STACK_SIZE
,
1893 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
1895 child_pid
= clone (linux_tracefork_child
, stack
+ STACK_SIZE
,
1896 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
1898 if (child_pid
== -1)
1899 perror_with_name ("clone");
1901 ret
= my_waitpid (child_pid
, &status
, 0);
1903 perror_with_name ("waitpid");
1904 else if (ret
!= child_pid
)
1905 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret
);
1906 if (! WIFSTOPPED (status
))
1907 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status
);
1909 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0, PTRACE_O_TRACEFORK
);
1912 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
1915 warning ("linux_test_for_tracefork: failed to kill child");
1919 ret
= my_waitpid (child_pid
, &status
, 0);
1920 if (ret
!= child_pid
)
1921 warning ("linux_test_for_tracefork: failed to wait for killed child");
1922 else if (!WIFSIGNALED (status
))
1923 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
1924 "killed child", status
);
1929 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
1931 warning ("linux_test_for_tracefork: failed to resume child");
1933 ret
= my_waitpid (child_pid
, &status
, 0);
1935 if (ret
== child_pid
&& WIFSTOPPED (status
)
1936 && status
>> 16 == PTRACE_EVENT_FORK
)
1939 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
1940 if (ret
== 0 && second_pid
!= 0)
1944 linux_supports_tracefork_flag
= 1;
1945 my_waitpid (second_pid
, &second_status
, 0);
1946 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
1948 warning ("linux_test_for_tracefork: failed to kill second child");
1949 my_waitpid (second_pid
, &status
, 0);
1953 warning ("linux_test_for_tracefork: unexpected result from waitpid "
1954 "(%d, status 0x%x)", ret
, status
);
1958 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
1960 warning ("linux_test_for_tracefork: failed to kill child");
1961 my_waitpid (child_pid
, &status
, 0);
1963 while (WIFSTOPPED (status
));
1970 linux_look_up_symbols (void)
1972 #ifdef USE_THREAD_DB
1973 if (thread_db_active
)
1976 thread_db_active
= thread_db_init (!linux_supports_tracefork_flag
);
1981 linux_request_interrupt (void)
1983 extern unsigned long signal_pid
;
1985 if (cont_thread
!= 0 && cont_thread
!= -1)
1987 struct lwp_info
*lwp
;
1989 lwp
= get_thread_lwp (current_inferior
);
1990 kill_lwp (lwp
->lwpid
, SIGINT
);
1993 kill_lwp (signal_pid
, SIGINT
);
1996 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
1997 to debugger memory starting at MYADDR. */
2000 linux_read_auxv (CORE_ADDR offset
, unsigned char *myaddr
, unsigned int len
)
2002 char filename
[PATH_MAX
];
2005 snprintf (filename
, sizeof filename
, "/proc/%ld/auxv", inferior_pid
);
2007 fd
= open (filename
, O_RDONLY
);
2011 if (offset
!= (CORE_ADDR
) 0
2012 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
2015 n
= read (fd
, myaddr
, len
);
2022 /* These watchpoint related wrapper functions simply pass on the function call
2023 if the target has registered a corresponding function. */
2026 linux_insert_watchpoint (char type
, CORE_ADDR addr
, int len
)
2028 if (the_low_target
.insert_watchpoint
!= NULL
)
2029 return the_low_target
.insert_watchpoint (type
, addr
, len
);
2031 /* Unsupported (see target.h). */
2036 linux_remove_watchpoint (char type
, CORE_ADDR addr
, int len
)
2038 if (the_low_target
.remove_watchpoint
!= NULL
)
2039 return the_low_target
.remove_watchpoint (type
, addr
, len
);
2041 /* Unsupported (see target.h). */
2046 linux_stopped_by_watchpoint (void)
2048 if (the_low_target
.stopped_by_watchpoint
!= NULL
)
2049 return the_low_target
.stopped_by_watchpoint ();
2055 linux_stopped_data_address (void)
2057 if (the_low_target
.stopped_data_address
!= NULL
)
2058 return the_low_target
.stopped_data_address ();
2063 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
2064 #if defined(__mcoldfire__)
2065 /* These should really be defined in the kernel's ptrace.h header. */
2066 #define PT_TEXT_ADDR 49*4
2067 #define PT_DATA_ADDR 50*4
2068 #define PT_TEXT_END_ADDR 51*4
2071 /* Under uClinux, programs are loaded at non-zero offsets, which we need
2072 to tell gdb about. */
2075 linux_read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
2077 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
2078 unsigned long text
, text_end
, data
;
2079 int pid
= get_thread_lwp (current_inferior
)->head
.id
;
2083 text
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_ADDR
, 0);
2084 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_END_ADDR
, 0);
2085 data
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_DATA_ADDR
, 0);
2089 /* Both text and data offsets produced at compile-time (and so
2090 used by gdb) are relative to the beginning of the program,
2091 with the data segment immediately following the text segment.
2092 However, the actual runtime layout in memory may put the data
2093 somewhere else, so when we send gdb a data base-address, we
2094 use the real data base address and subtract the compile-time
2095 data base-address from it (which is just the length of the
2096 text segment). BSS immediately follows data in both
2099 *data_p
= data
- (text_end
- text
);
2109 linux_qxfer_osdata (const char *annex
,
2110 unsigned char *readbuf
, unsigned const char *writebuf
,
2111 CORE_ADDR offset
, int len
)
2113 /* We make the process list snapshot when the object starts to be
2115 static const char *buf
;
2116 static long len_avail
= -1;
2117 static struct buffer buffer
;
2121 if (strcmp (annex
, "processes") != 0)
2124 if (!readbuf
|| writebuf
)
2129 if (len_avail
!= -1 && len_avail
!= 0)
2130 buffer_free (&buffer
);
2133 buffer_init (&buffer
);
2134 buffer_grow_str (&buffer
, "<osdata type=\"processes\">");
2136 dirp
= opendir ("/proc");
2140 while ((dp
= readdir (dirp
)) != NULL
)
2142 struct stat statbuf
;
2143 char procentry
[sizeof ("/proc/4294967295")];
2145 if (!isdigit (dp
->d_name
[0])
2146 || strlen (dp
->d_name
) > sizeof ("4294967295") - 1)
2149 sprintf (procentry
, "/proc/%s", dp
->d_name
);
2150 if (stat (procentry
, &statbuf
) == 0
2151 && S_ISDIR (statbuf
.st_mode
))
2155 char cmd
[MAXPATHLEN
+ 1];
2156 struct passwd
*entry
;
2158 sprintf (pathname
, "/proc/%s/cmdline", dp
->d_name
);
2159 entry
= getpwuid (statbuf
.st_uid
);
2161 if ((f
= fopen (pathname
, "r")) != NULL
)
2163 size_t len
= fread (cmd
, 1, sizeof (cmd
) - 1, f
);
2167 for (i
= 0; i
< len
; i
++)
2175 "<column name=\"pid\">%s</column>"
2176 "<column name=\"user\">%s</column>"
2177 "<column name=\"command\">%s</column>"
2180 entry
? entry
->pw_name
: "?",
2190 buffer_grow_str0 (&buffer
, "</osdata>\n");
2191 buf
= buffer_finish (&buffer
);
2192 len_avail
= strlen (buf
);
2195 if (offset
>= len_avail
)
2197 /* Done. Get rid of the data. */
2198 buffer_free (&buffer
);
2204 if (len
> len_avail
- offset
)
2205 len
= len_avail
- offset
;
2206 memcpy (readbuf
, buf
+ offset
, len
);
2212 linux_xfer_siginfo (const char *annex
, unsigned char *readbuf
,
2213 unsigned const char *writebuf
, CORE_ADDR offset
, int len
)
2215 struct siginfo siginfo
;
2218 if (current_inferior
== NULL
)
2221 pid
= pid_of (get_thread_lwp (current_inferior
));
2224 fprintf (stderr
, "%s siginfo for lwp %ld.\n",
2225 readbuf
!= NULL
? "Reading" : "Writing",
2228 if (offset
> sizeof (siginfo
))
2231 if (ptrace (PTRACE_GETSIGINFO
, pid
, 0, &siginfo
) != 0)
2234 if (offset
+ len
> sizeof (siginfo
))
2235 len
= sizeof (siginfo
) - offset
;
2237 if (readbuf
!= NULL
)
2238 memcpy (readbuf
, (char *) &siginfo
+ offset
, len
);
2241 memcpy ((char *) &siginfo
+ offset
, writebuf
, len
);
2242 if (ptrace (PTRACE_SETSIGINFO
, pid
, 0, &siginfo
) != 0)
2249 static struct target_ops linux_target_ops
= {
2250 linux_create_inferior
,
2258 linux_fetch_registers
,
2259 linux_store_registers
,
2262 linux_look_up_symbols
,
2263 linux_request_interrupt
,
2265 linux_insert_watchpoint
,
2266 linux_remove_watchpoint
,
2267 linux_stopped_by_watchpoint
,
2268 linux_stopped_data_address
,
2269 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
2274 #ifdef USE_THREAD_DB
2275 thread_db_get_tls_address
,
2280 hostio_last_error_from_errno
,
2286 linux_init_signals ()
2288 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
2289 to find what the cancel signal actually is. */
2290 signal (__SIGRTMIN
+1, SIG_IGN
);
2294 initialize_low (void)
2296 thread_db_active
= 0;
2297 set_target_ops (&linux_target_ops
);
2298 set_breakpoint_data (the_low_target
.breakpoint
,
2299 the_low_target
.breakpoint_len
);
2300 linux_init_signals ();
2301 linux_test_for_tracefork ();
2302 #ifdef HAVE_LINUX_REGSETS
2303 for (num_regsets
= 0; target_regsets
[num_regsets
].size
>= 0; num_regsets
++)
2305 disabled_regsets
= xmalloc (num_regsets
);