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 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>
27 #include <sys/ptrace.h>
30 #include <sys/ioctl.h>
36 #include <sys/syscall.h>
38 #ifndef PTRACE_GETSIGINFO
39 # define PTRACE_GETSIGINFO 0x4202
40 # define PTRACE_SETSIGINFO 0x4203
44 #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
49 /* ``all_threads'' is keyed by the LWP ID - it should be the thread ID instead,
50 however. This requires changing the ID in place when we go from !using_threads
51 to using_threads, immediately.
53 ``all_processes'' is keyed by the process ID - which on Linux is (presently)
54 the same as the LWP ID. */
56 struct inferior_list all_processes
;
58 /* FIXME this is a bit of a hack, and could be removed. */
61 /* FIXME make into a target method? */
64 static void linux_resume_one_process (struct inferior_list_entry
*entry
,
65 int step
, int signal
, siginfo_t
*info
);
66 static void linux_resume (struct thread_resume
*resume_info
);
67 static void stop_all_processes (void);
68 static int linux_wait_for_event (struct thread_info
*child
);
69 static int check_removed_breakpoint (struct process_info
*event_child
);
71 struct pending_signals
75 struct pending_signals
*prev
;
78 #define PTRACE_ARG3_TYPE long
79 #define PTRACE_XFER_TYPE long
81 #ifdef HAVE_LINUX_REGSETS
82 static int use_regsets_p
= 1;
85 #define pid_of(proc) ((proc)->head.id)
87 /* FIXME: Delete eventually. */
88 #define inferior_pid (pid_of (get_thread_process (current_inferior)))
90 /* This function should only be called if the process got a SIGTRAP.
91 The SIGTRAP could mean several things.
93 On i386, where decr_pc_after_break is non-zero:
94 If we were single-stepping this process using PTRACE_SINGLESTEP,
95 we will get only the one SIGTRAP (even if the instruction we
96 stepped over was a breakpoint). The value of $eip will be the
98 If we continue the process using PTRACE_CONT, we will get a
99 SIGTRAP when we hit a breakpoint. The value of $eip will be
100 the instruction after the breakpoint (i.e. needs to be
101 decremented). If we report the SIGTRAP to GDB, we must also
102 report the undecremented PC. If we cancel the SIGTRAP, we
103 must resume at the decremented PC.
105 (Presumably, not yet tested) On a non-decr_pc_after_break machine
106 with hardware or kernel single-step:
107 If we single-step over a breakpoint instruction, our PC will
108 point at the following instruction. If we continue and hit a
109 breakpoint instruction, our PC will point at the breakpoint
115 CORE_ADDR stop_pc
= (*the_low_target
.get_pc
) ();
117 if (get_thread_process (current_inferior
)->stepping
)
120 return stop_pc
- the_low_target
.decr_pc_after_break
;
124 add_process (unsigned long pid
)
126 struct process_info
*process
;
128 process
= (struct process_info
*) malloc (sizeof (*process
));
129 memset (process
, 0, sizeof (*process
));
131 process
->head
.id
= pid
;
133 /* Default to tid == lwpid == pid. */
135 process
->lwpid
= pid
;
137 add_inferior_to_list (&all_processes
, &process
->head
);
142 /* Start an inferior process and returns its pid.
143 ALLARGS is a vector of program-name and args. */
146 linux_create_inferior (char *program
, char **allargs
)
151 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
157 perror_with_name ("fork");
161 ptrace (PTRACE_TRACEME
, 0, 0, 0);
163 signal (__SIGRTMIN
+ 1, SIG_DFL
);
167 execv (program
, allargs
);
169 execvp (program
, allargs
);
171 fprintf (stderr
, "Cannot exec %s: %s.\n", program
,
177 new_process
= add_process (pid
);
178 add_thread (pid
, new_process
, pid
);
183 /* Attach to an inferior process. */
186 linux_attach_lwp (unsigned long pid
, unsigned long tid
)
188 struct process_info
*new_process
;
190 if (ptrace (PTRACE_ATTACH
, pid
, 0, 0) != 0)
192 fprintf (stderr
, "Cannot attach to process %ld: %s (%d)\n", pid
,
193 strerror (errno
), errno
);
196 /* If we fail to attach to an LWP, just return. */
202 new_process
= (struct process_info
*) add_process (pid
);
203 add_thread (tid
, new_process
, pid
);
205 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
206 brings it to a halt. We should ignore that SIGSTOP and resume the process
207 (unless this is the first process, in which case the flag will be cleared
210 On the other hand, if we are currently trying to stop all threads, we
211 should treat the new thread as if we had sent it a SIGSTOP. This works
212 because we are guaranteed that add_process added us to the end of the
213 list, and so the new thread has not yet reached wait_for_sigstop (but
215 if (! stopping_threads
)
216 new_process
->stop_expected
= 1;
220 linux_attach (unsigned long pid
)
222 struct process_info
*process
;
224 linux_attach_lwp (pid
, pid
);
226 /* Don't ignore the initial SIGSTOP if we just attached to this process.
227 It will be collected by wait shortly. */
228 process
= (struct process_info
*) find_inferior_id (&all_processes
, pid
);
229 process
->stop_expected
= 0;
234 /* Kill the inferior process. Make us have no inferior. */
237 linux_kill_one_process (struct inferior_list_entry
*entry
)
239 struct thread_info
*thread
= (struct thread_info
*) entry
;
240 struct process_info
*process
= get_thread_process (thread
);
243 /* We avoid killing the first thread here, because of a Linux kernel (at
244 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
245 the children get a chance to be reaped, it will remain a zombie
247 if (entry
== all_threads
.head
)
252 ptrace (PTRACE_KILL
, pid_of (process
), 0, 0);
254 /* Make sure it died. The loop is most likely unnecessary. */
255 wstat
= linux_wait_for_event (thread
);
256 } while (WIFSTOPPED (wstat
));
262 struct thread_info
*thread
= (struct thread_info
*) all_threads
.head
;
263 struct process_info
*process
;
269 for_each_inferior (&all_threads
, linux_kill_one_process
);
271 /* See the comment in linux_kill_one_process. We did not kill the first
272 thread in the list, so do so now. */
273 process
= get_thread_process (thread
);
276 ptrace (PTRACE_KILL
, pid_of (process
), 0, 0);
278 /* Make sure it died. The loop is most likely unnecessary. */
279 wstat
= linux_wait_for_event (thread
);
280 } while (WIFSTOPPED (wstat
));
284 linux_detach_one_process (struct inferior_list_entry
*entry
)
286 struct thread_info
*thread
= (struct thread_info
*) entry
;
287 struct process_info
*process
= get_thread_process (thread
);
289 /* Make sure the process isn't stopped at a breakpoint that's
291 check_removed_breakpoint (process
);
293 /* If this process is stopped but is expecting a SIGSTOP, then make
294 sure we take care of that now. This isn't absolutely guaranteed
295 to collect the SIGSTOP, but is fairly likely to. */
296 if (process
->stop_expected
)
298 /* Clear stop_expected, so that the SIGSTOP will be reported. */
299 process
->stop_expected
= 0;
300 if (process
->stopped
)
301 linux_resume_one_process (&process
->head
, 0, 0, NULL
);
302 linux_wait_for_event (thread
);
305 /* Flush any pending changes to the process's registers. */
306 regcache_invalidate_one ((struct inferior_list_entry
*)
307 get_process_thread (process
));
309 /* Finally, let it resume. */
310 ptrace (PTRACE_DETACH
, pid_of (process
), 0, 0);
316 delete_all_breakpoints ();
317 for_each_inferior (&all_threads
, linux_detach_one_process
);
325 extern unsigned long signal_pid
;
329 ret
= waitpid (signal_pid
, &status
, 0);
330 if (WIFEXITED (status
) || WIFSIGNALED (status
))
332 } while (ret
!= -1 || errno
!= ECHILD
);
335 /* Return nonzero if the given thread is still alive. */
337 linux_thread_alive (unsigned long tid
)
339 if (find_inferior_id (&all_threads
, tid
) != NULL
)
345 /* Return nonzero if this process stopped at a breakpoint which
346 no longer appears to be inserted. Also adjust the PC
347 appropriately to resume where the breakpoint used to be. */
349 check_removed_breakpoint (struct process_info
*event_child
)
352 struct thread_info
*saved_inferior
;
354 if (event_child
->pending_is_breakpoint
== 0)
358 fprintf (stderr
, "Checking for breakpoint in process %ld.\n",
361 saved_inferior
= current_inferior
;
362 current_inferior
= get_process_thread (event_child
);
364 stop_pc
= get_stop_pc ();
366 /* If the PC has changed since we stopped, then we shouldn't do
367 anything. This happens if, for instance, GDB handled the
368 decr_pc_after_break subtraction itself. */
369 if (stop_pc
!= event_child
->pending_stop_pc
)
372 fprintf (stderr
, "Ignoring, PC was changed. Old PC was 0x%08llx\n",
373 event_child
->pending_stop_pc
);
375 event_child
->pending_is_breakpoint
= 0;
376 current_inferior
= saved_inferior
;
380 /* If the breakpoint is still there, we will report hitting it. */
381 if ((*the_low_target
.breakpoint_at
) (stop_pc
))
384 fprintf (stderr
, "Ignoring, breakpoint is still present.\n");
385 current_inferior
= saved_inferior
;
390 fprintf (stderr
, "Removed breakpoint.\n");
392 /* For decr_pc_after_break targets, here is where we perform the
393 decrement. We go immediately from this function to resuming,
394 and can not safely call get_stop_pc () again. */
395 if (the_low_target
.set_pc
!= NULL
)
396 (*the_low_target
.set_pc
) (stop_pc
);
398 /* We consumed the pending SIGTRAP. */
399 event_child
->pending_is_breakpoint
= 0;
400 event_child
->status_pending_p
= 0;
401 event_child
->status_pending
= 0;
403 current_inferior
= saved_inferior
;
407 /* Return 1 if this process has an interesting status pending. This function
408 may silently resume an inferior process. */
410 status_pending_p (struct inferior_list_entry
*entry
, void *dummy
)
412 struct process_info
*process
= (struct process_info
*) entry
;
414 if (process
->status_pending_p
)
415 if (check_removed_breakpoint (process
))
417 /* This thread was stopped at a breakpoint, and the breakpoint
418 is now gone. We were told to continue (or step...) all threads,
419 so GDB isn't trying to single-step past this breakpoint.
420 So instead of reporting the old SIGTRAP, pretend we got to
421 the breakpoint just after it was removed instead of just
422 before; resume the process. */
423 linux_resume_one_process (&process
->head
, 0, 0, NULL
);
427 return process
->status_pending_p
;
431 linux_wait_for_process (struct process_info
**childp
, int *wstatp
)
434 int to_wait_for
= -1;
437 to_wait_for
= (*childp
)->lwpid
;
441 ret
= waitpid (to_wait_for
, wstatp
, WNOHANG
);
446 perror_with_name ("waitpid");
451 ret
= waitpid (to_wait_for
, wstatp
, WNOHANG
| __WCLONE
);
456 perror_with_name ("waitpid (WCLONE)");
465 && (!WIFSTOPPED (*wstatp
)
466 || (WSTOPSIG (*wstatp
) != 32
467 && WSTOPSIG (*wstatp
) != 33)))
468 fprintf (stderr
, "Got an event from %d (%x)\n", ret
, *wstatp
);
470 if (to_wait_for
== -1)
471 *childp
= (struct process_info
*) find_inferior_id (&all_processes
, ret
);
473 (*childp
)->stopped
= 1;
474 (*childp
)->pending_is_breakpoint
= 0;
476 (*childp
)->last_status
= *wstatp
;
479 && WIFSTOPPED (*wstatp
))
481 current_inferior
= (struct thread_info
*)
482 find_inferior_id (&all_threads
, (*childp
)->tid
);
483 /* For testing only; i386_stop_pc prints out a diagnostic. */
484 if (the_low_target
.get_pc
!= NULL
)
490 linux_wait_for_event (struct thread_info
*child
)
493 struct process_info
*event_child
;
496 /* Check for a process with a pending status. */
497 /* It is possible that the user changed the pending task's registers since
498 it stopped. We correctly handle the change of PC if we hit a breakpoint
499 (in check_removed_breakpoint); signals should be reported anyway. */
502 event_child
= (struct process_info
*)
503 find_inferior (&all_processes
, status_pending_p
, NULL
);
504 if (debug_threads
&& event_child
)
505 fprintf (stderr
, "Got a pending child %ld\n", event_child
->lwpid
);
509 event_child
= get_thread_process (child
);
510 if (event_child
->status_pending_p
511 && check_removed_breakpoint (event_child
))
515 if (event_child
!= NULL
)
517 if (event_child
->status_pending_p
)
520 fprintf (stderr
, "Got an event from pending child %ld (%04x)\n",
521 event_child
->lwpid
, event_child
->status_pending
);
522 wstat
= event_child
->status_pending
;
523 event_child
->status_pending_p
= 0;
524 event_child
->status_pending
= 0;
525 current_inferior
= get_process_thread (event_child
);
530 /* We only enter this loop if no process has a pending wait status. Thus
531 any action taken in response to a wait status inside this loop is
532 responding as soon as we detect the status, not after any pending
539 event_child
= get_thread_process (child
);
541 linux_wait_for_process (&event_child
, &wstat
);
543 if (event_child
== NULL
)
544 error ("event from unknown child");
546 current_inferior
= (struct thread_info
*)
547 find_inferior_id (&all_threads
, event_child
->tid
);
549 /* Check for thread exit. */
550 if (using_threads
&& ! WIFSTOPPED (wstat
))
553 fprintf (stderr
, "Thread %ld (LWP %ld) exiting\n",
554 event_child
->tid
, event_child
->head
.id
);
556 /* If the last thread is exiting, just return. */
557 if (all_threads
.head
== all_threads
.tail
)
560 dead_thread_notify (event_child
->tid
);
562 remove_inferior (&all_processes
, &event_child
->head
);
564 remove_thread (current_inferior
);
565 current_inferior
= (struct thread_info
*) all_threads
.head
;
567 /* If we were waiting for this particular child to do something...
568 well, it did something. */
572 /* Wait for a more interesting event. */
577 && WIFSTOPPED (wstat
)
578 && WSTOPSIG (wstat
) == SIGSTOP
579 && event_child
->stop_expected
)
582 fprintf (stderr
, "Expected stop.\n");
583 event_child
->stop_expected
= 0;
584 linux_resume_one_process (&event_child
->head
,
585 event_child
->stepping
, 0, NULL
);
589 /* If GDB is not interested in this signal, don't stop other
590 threads, and don't report it to GDB. Just resume the
591 inferior right away. We do this for threading-related
592 signals as well as any that GDB specifically requested we
593 ignore. But never ignore SIGSTOP if we sent it ourselves,
594 and do not ignore signals when stepping - they may require
595 special handling to skip the signal handler. */
596 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
598 if (WIFSTOPPED (wstat
)
599 && !event_child
->stepping
600 && ((using_threads
&& (WSTOPSIG (wstat
) == __SIGRTMIN
601 || WSTOPSIG (wstat
) == __SIGRTMIN
+ 1))
602 || (pass_signals
[target_signal_from_host (WSTOPSIG (wstat
))]
603 && (WSTOPSIG (wstat
) != SIGSTOP
604 || !event_child
->sigstop_sent
))))
606 siginfo_t info
, *info_p
;
609 fprintf (stderr
, "Ignored signal %d for %ld (LWP %ld).\n",
610 WSTOPSIG (wstat
), event_child
->tid
,
611 event_child
->head
.id
);
613 if (ptrace (PTRACE_GETSIGINFO
, event_child
->lwpid
, 0, &info
) == 0)
617 linux_resume_one_process (&event_child
->head
,
618 event_child
->stepping
,
619 WSTOPSIG (wstat
), info_p
);
623 /* If this event was not handled above, and is not a SIGTRAP, report
625 if (!WIFSTOPPED (wstat
) || WSTOPSIG (wstat
) != SIGTRAP
)
628 /* If this target does not support breakpoints, we simply report the
629 SIGTRAP; it's of no concern to us. */
630 if (the_low_target
.get_pc
== NULL
)
633 stop_pc
= get_stop_pc ();
635 /* bp_reinsert will only be set if we were single-stepping.
636 Notice that we will resume the process after hitting
637 a gdbserver breakpoint; single-stepping to/over one
638 is not supported (yet). */
639 if (event_child
->bp_reinsert
!= 0)
642 fprintf (stderr
, "Reinserted breakpoint.\n");
643 reinsert_breakpoint (event_child
->bp_reinsert
);
644 event_child
->bp_reinsert
= 0;
646 /* Clear the single-stepping flag and SIGTRAP as we resume. */
647 linux_resume_one_process (&event_child
->head
, 0, 0, NULL
);
652 fprintf (stderr
, "Hit a (non-reinsert) breakpoint.\n");
654 if (check_breakpoints (stop_pc
) != 0)
656 /* We hit one of our own breakpoints. We mark it as a pending
657 breakpoint, so that check_removed_breakpoint () will do the PC
658 adjustment for us at the appropriate time. */
659 event_child
->pending_is_breakpoint
= 1;
660 event_child
->pending_stop_pc
= stop_pc
;
662 /* Now we need to put the breakpoint back. We continue in the event
663 loop instead of simply replacing the breakpoint right away,
664 in order to not lose signals sent to the thread that hit the
665 breakpoint. Unfortunately this increases the window where another
666 thread could sneak past the removed breakpoint. For the current
667 use of server-side breakpoints (thread creation) this is
668 acceptable; but it needs to be considered before this breakpoint
669 mechanism can be used in more general ways. For some breakpoints
670 it may be necessary to stop all other threads, but that should
671 be avoided where possible.
673 If breakpoint_reinsert_addr is NULL, that means that we can
674 use PTRACE_SINGLESTEP on this platform. Uninsert the breakpoint,
675 mark it for reinsertion, and single-step.
677 Otherwise, call the target function to figure out where we need
678 our temporary breakpoint, create it, and continue executing this
680 if (the_low_target
.breakpoint_reinsert_addr
== NULL
)
682 event_child
->bp_reinsert
= stop_pc
;
683 uninsert_breakpoint (stop_pc
);
684 linux_resume_one_process (&event_child
->head
, 1, 0, NULL
);
688 reinsert_breakpoint_by_bp
689 (stop_pc
, (*the_low_target
.breakpoint_reinsert_addr
) ());
690 linux_resume_one_process (&event_child
->head
, 0, 0, NULL
);
696 /* If we were single-stepping, we definitely want to report the
697 SIGTRAP. The single-step operation has completed, so also
698 clear the stepping flag; in general this does not matter,
699 because the SIGTRAP will be reported to the client, which
700 will give us a new action for this thread, but clear it for
701 consistency anyway. It's safe to clear the stepping flag
702 because the only consumer of get_stop_pc () after this point
703 is check_removed_breakpoint, and pending_is_breakpoint is not
704 set. It might be wiser to use a step_completed flag instead. */
705 if (event_child
->stepping
)
707 event_child
->stepping
= 0;
711 /* A SIGTRAP that we can't explain. It may have been a breakpoint.
712 Check if it is a breakpoint, and if so mark the process information
713 accordingly. This will handle both the necessary fiddling with the
714 PC on decr_pc_after_break targets and suppressing extra threads
715 hitting a breakpoint if two hit it at once and then GDB removes it
716 after the first is reported. Arguably it would be better to report
717 multiple threads hitting breakpoints simultaneously, but the current
718 remote protocol does not allow this. */
719 if ((*the_low_target
.breakpoint_at
) (stop_pc
))
721 event_child
->pending_is_breakpoint
= 1;
722 event_child
->pending_stop_pc
= stop_pc
;
732 /* Wait for process, returns status. */
735 linux_wait (char *status
)
738 struct thread_info
*child
= NULL
;
741 /* If we were only supposed to resume one thread, only wait for
742 that thread - if it's still alive. If it died, however - which
743 can happen if we're coming from the thread death case below -
744 then we need to make sure we restart the other threads. We could
745 pick a thread at random or restart all; restarting all is less
747 if (cont_thread
!= 0 && cont_thread
!= -1)
749 child
= (struct thread_info
*) find_inferior_id (&all_threads
,
752 /* No stepping, no signal - unless one is pending already, of course. */
755 struct thread_resume resume_info
;
756 resume_info
.thread
= -1;
757 resume_info
.step
= resume_info
.sig
= resume_info
.leave_stopped
= 0;
758 linux_resume (&resume_info
);
764 w
= linux_wait_for_event (child
);
765 stop_all_processes ();
768 /* If we are waiting for a particular child, and it exited,
769 linux_wait_for_event will return its exit status. Similarly if
770 the last child exited. If this is not the last child, however,
771 do not report it as exited until there is a 'thread exited' response
772 available in the remote protocol. Instead, just wait for another event.
773 This should be safe, because if the thread crashed we will already
774 have reported the termination signal to GDB; that should stop any
775 in-progress stepping operations, etc.
777 Report the exit status of the last thread to exit. This matches
778 LinuxThreads' behavior. */
780 if (all_threads
.head
== all_threads
.tail
)
784 fprintf (stderr
, "\nChild exited with retcode = %x \n", WEXITSTATUS (w
));
787 free (all_processes
.head
);
788 all_processes
.head
= all_processes
.tail
= NULL
;
789 return WEXITSTATUS (w
);
791 else if (!WIFSTOPPED (w
))
793 fprintf (stderr
, "\nChild terminated with signal = %x \n", WTERMSIG (w
));
796 free (all_processes
.head
);
797 all_processes
.head
= all_processes
.tail
= NULL
;
798 return target_signal_from_host (WTERMSIG (w
));
808 return target_signal_from_host (WSTOPSIG (w
));
811 /* Send a signal to an LWP. For LinuxThreads, kill is enough; however, if
812 thread groups are in use, we need to use tkill. */
815 kill_lwp (unsigned long lwpid
, int signo
)
817 static int tkill_failed
;
824 int ret
= syscall (SYS_tkill
, lwpid
, signo
);
832 return kill (lwpid
, signo
);
836 send_sigstop (struct inferior_list_entry
*entry
)
838 struct process_info
*process
= (struct process_info
*) entry
;
840 if (process
->stopped
)
843 /* If we already have a pending stop signal for this process, don't
845 if (process
->stop_expected
)
848 fprintf (stderr
, "Have pending sigstop for process %ld\n",
851 /* We clear the stop_expected flag so that wait_for_sigstop
852 will receive the SIGSTOP event (instead of silently resuming and
853 waiting again). It'll be reset below. */
854 process
->stop_expected
= 0;
859 fprintf (stderr
, "Sending sigstop to process %ld\n", process
->head
.id
);
861 kill_lwp (process
->head
.id
, SIGSTOP
);
862 process
->sigstop_sent
= 1;
866 wait_for_sigstop (struct inferior_list_entry
*entry
)
868 struct process_info
*process
= (struct process_info
*) entry
;
869 struct thread_info
*saved_inferior
, *thread
;
871 unsigned long saved_tid
;
873 if (process
->stopped
)
876 saved_inferior
= current_inferior
;
877 saved_tid
= ((struct inferior_list_entry
*) saved_inferior
)->id
;
878 thread
= (struct thread_info
*) find_inferior_id (&all_threads
,
880 wstat
= linux_wait_for_event (thread
);
882 /* If we stopped with a non-SIGSTOP signal, save it for later
883 and record the pending SIGSTOP. If the process exited, just
885 if (WIFSTOPPED (wstat
)
886 && WSTOPSIG (wstat
) != SIGSTOP
)
889 fprintf (stderr
, "Process %ld (thread %ld) "
890 "stopped with non-sigstop status %06x\n",
891 process
->lwpid
, process
->tid
, wstat
);
892 process
->status_pending_p
= 1;
893 process
->status_pending
= wstat
;
894 process
->stop_expected
= 1;
897 if (linux_thread_alive (saved_tid
))
898 current_inferior
= saved_inferior
;
902 fprintf (stderr
, "Previously current thread died.\n");
904 /* Set a valid thread as current. */
905 set_desired_inferior (0);
910 stop_all_processes (void)
912 stopping_threads
= 1;
913 for_each_inferior (&all_processes
, send_sigstop
);
914 for_each_inferior (&all_processes
, wait_for_sigstop
);
915 stopping_threads
= 0;
918 /* Resume execution of the inferior process.
919 If STEP is nonzero, single-step it.
920 If SIGNAL is nonzero, give it that signal. */
923 linux_resume_one_process (struct inferior_list_entry
*entry
,
924 int step
, int signal
, siginfo_t
*info
)
926 struct process_info
*process
= (struct process_info
*) entry
;
927 struct thread_info
*saved_inferior
;
929 if (process
->stopped
== 0)
932 /* If we have pending signals or status, and a new signal, enqueue the
933 signal. Also enqueue the signal if we are waiting to reinsert a
934 breakpoint; it will be picked up again below. */
936 && (process
->status_pending_p
|| process
->pending_signals
!= NULL
937 || process
->bp_reinsert
!= 0))
939 struct pending_signals
*p_sig
;
940 p_sig
= malloc (sizeof (*p_sig
));
941 p_sig
->prev
= process
->pending_signals
;
942 p_sig
->signal
= signal
;
944 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
946 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
947 process
->pending_signals
= p_sig
;
950 if (process
->status_pending_p
&& !check_removed_breakpoint (process
))
953 saved_inferior
= current_inferior
;
954 current_inferior
= get_process_thread (process
);
957 fprintf (stderr
, "Resuming process %ld (%s, signal %d, stop %s)\n", inferior_pid
,
958 step
? "step" : "continue", signal
,
959 process
->stop_expected
? "expected" : "not expected");
961 /* This bit needs some thinking about. If we get a signal that
962 we must report while a single-step reinsert is still pending,
963 we often end up resuming the thread. It might be better to
964 (ew) allow a stack of pending events; then we could be sure that
965 the reinsert happened right away and not lose any signals.
967 Making this stack would also shrink the window in which breakpoints are
968 uninserted (see comment in linux_wait_for_process) but not enough for
969 complete correctness, so it won't solve that problem. It may be
970 worthwhile just to solve this one, however. */
971 if (process
->bp_reinsert
!= 0)
974 fprintf (stderr
, " pending reinsert at %08lx", (long)process
->bp_reinsert
);
976 fprintf (stderr
, "BAD - reinserting but not stepping.\n");
979 /* Postpone any pending signal. It was enqueued above. */
983 check_removed_breakpoint (process
);
985 if (debug_threads
&& the_low_target
.get_pc
!= NULL
)
987 fprintf (stderr
, " ");
988 (*the_low_target
.get_pc
) ();
991 /* If we have pending signals, consume one unless we are trying to reinsert
993 if (process
->pending_signals
!= NULL
&& process
->bp_reinsert
== 0)
995 struct pending_signals
**p_sig
;
997 p_sig
= &process
->pending_signals
;
998 while ((*p_sig
)->prev
!= NULL
)
999 p_sig
= &(*p_sig
)->prev
;
1001 signal
= (*p_sig
)->signal
;
1002 if ((*p_sig
)->info
.si_signo
!= 0)
1003 ptrace (PTRACE_SETSIGINFO
, process
->lwpid
, 0, &(*p_sig
)->info
);
1009 regcache_invalidate_one ((struct inferior_list_entry
*)
1010 get_process_thread (process
));
1012 process
->stopped
= 0;
1013 process
->stepping
= step
;
1014 ptrace (step
? PTRACE_SINGLESTEP
: PTRACE_CONT
, process
->lwpid
, 0, signal
);
1016 current_inferior
= saved_inferior
;
1018 perror_with_name ("ptrace");
1021 static struct thread_resume
*resume_ptr
;
1023 /* This function is called once per thread. We look up the thread
1024 in RESUME_PTR, and mark the thread with a pointer to the appropriate
1027 This algorithm is O(threads * resume elements), but resume elements
1028 is small (and will remain small at least until GDB supports thread
1031 linux_set_resume_request (struct inferior_list_entry
*entry
)
1033 struct process_info
*process
;
1034 struct thread_info
*thread
;
1037 thread
= (struct thread_info
*) entry
;
1038 process
= get_thread_process (thread
);
1041 while (resume_ptr
[ndx
].thread
!= -1 && resume_ptr
[ndx
].thread
!= entry
->id
)
1044 process
->resume
= &resume_ptr
[ndx
];
1047 /* This function is called once per thread. We check the thread's resume
1048 request, which will tell us whether to resume, step, or leave the thread
1049 stopped; and what signal, if any, it should be sent. For threads which
1050 we aren't explicitly told otherwise, we preserve the stepping flag; this
1051 is used for stepping over gdbserver-placed breakpoints. */
1054 linux_continue_one_thread (struct inferior_list_entry
*entry
)
1056 struct process_info
*process
;
1057 struct thread_info
*thread
;
1060 thread
= (struct thread_info
*) entry
;
1061 process
= get_thread_process (thread
);
1063 if (process
->resume
->leave_stopped
)
1066 if (process
->resume
->thread
== -1)
1067 step
= process
->stepping
|| process
->resume
->step
;
1069 step
= process
->resume
->step
;
1071 linux_resume_one_process (&process
->head
, step
, process
->resume
->sig
, NULL
);
1073 process
->resume
= NULL
;
1076 /* This function is called once per thread. We check the thread's resume
1077 request, which will tell us whether to resume, step, or leave the thread
1078 stopped; and what signal, if any, it should be sent. We queue any needed
1079 signals, since we won't actually resume. We already have a pending event
1080 to report, so we don't need to preserve any step requests; they should
1081 be re-issued if necessary. */
1084 linux_queue_one_thread (struct inferior_list_entry
*entry
)
1086 struct process_info
*process
;
1087 struct thread_info
*thread
;
1089 thread
= (struct thread_info
*) entry
;
1090 process
= get_thread_process (thread
);
1092 if (process
->resume
->leave_stopped
)
1095 /* If we have a new signal, enqueue the signal. */
1096 if (process
->resume
->sig
!= 0)
1098 struct pending_signals
*p_sig
;
1099 p_sig
= malloc (sizeof (*p_sig
));
1100 p_sig
->prev
= process
->pending_signals
;
1101 p_sig
->signal
= process
->resume
->sig
;
1102 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
1104 /* If this is the same signal we were previously stopped by,
1105 make sure to queue its siginfo. We can ignore the return
1106 value of ptrace; if it fails, we'll skip
1107 PTRACE_SETSIGINFO. */
1108 if (WIFSTOPPED (process
->last_status
)
1109 && WSTOPSIG (process
->last_status
) == process
->resume
->sig
)
1110 ptrace (PTRACE_GETSIGINFO
, process
->lwpid
, 0, &p_sig
->info
);
1112 process
->pending_signals
= p_sig
;
1115 process
->resume
= NULL
;
1118 /* Set DUMMY if this process has an interesting status pending. */
1120 resume_status_pending_p (struct inferior_list_entry
*entry
, void *flag_p
)
1122 struct process_info
*process
= (struct process_info
*) entry
;
1124 /* Processes which will not be resumed are not interesting, because
1125 we might not wait for them next time through linux_wait. */
1126 if (process
->resume
->leave_stopped
)
1129 /* If this thread has a removed breakpoint, we won't have any
1130 events to report later, so check now. check_removed_breakpoint
1131 may clear status_pending_p. We avoid calling check_removed_breakpoint
1132 for any thread that we are not otherwise going to resume - this
1133 lets us preserve stopped status when two threads hit a breakpoint.
1134 GDB removes the breakpoint to single-step a particular thread
1135 past it, then re-inserts it and resumes all threads. We want
1136 to report the second thread without resuming it in the interim. */
1137 if (process
->status_pending_p
)
1138 check_removed_breakpoint (process
);
1140 if (process
->status_pending_p
)
1141 * (int *) flag_p
= 1;
1147 linux_resume (struct thread_resume
*resume_info
)
1151 /* Yes, the use of a global here is rather ugly. */
1152 resume_ptr
= resume_info
;
1154 for_each_inferior (&all_threads
, linux_set_resume_request
);
1156 /* If there is a thread which would otherwise be resumed, which
1157 has a pending status, then don't resume any threads - we can just
1158 report the pending status. Make sure to queue any signals
1159 that would otherwise be sent. */
1161 find_inferior (&all_processes
, resume_status_pending_p
, &pending_flag
);
1166 fprintf (stderr
, "Not resuming, pending status\n");
1168 fprintf (stderr
, "Resuming, no pending status\n");
1172 for_each_inferior (&all_threads
, linux_queue_one_thread
);
1177 for_each_inferior (&all_threads
, linux_continue_one_thread
);
1181 #ifdef HAVE_LINUX_USRREGS
1184 register_addr (int regnum
)
1188 if (regnum
< 0 || regnum
>= the_low_target
.num_regs
)
1189 error ("Invalid register number %d.", regnum
);
1191 addr
= the_low_target
.regmap
[regnum
];
1196 /* Fetch one register. */
1198 fetch_register (int regno
)
1204 if (regno
>= the_low_target
.num_regs
)
1206 if ((*the_low_target
.cannot_fetch_register
) (regno
))
1209 regaddr
= register_addr (regno
);
1212 size
= (register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
1213 & - sizeof (PTRACE_XFER_TYPE
);
1214 buf
= alloca (size
);
1215 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
1218 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
1219 ptrace (PTRACE_PEEKUSER
, inferior_pid
, (PTRACE_ARG3_TYPE
) regaddr
, 0);
1220 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
1223 /* Warning, not error, in case we are attached; sometimes the
1224 kernel doesn't let us at the registers. */
1225 char *err
= strerror (errno
);
1226 char *msg
= alloca (strlen (err
) + 128);
1227 sprintf (msg
, "reading register %d: %s", regno
, err
);
1232 if (the_low_target
.left_pad_xfer
1233 && register_size (regno
) < sizeof (PTRACE_XFER_TYPE
))
1234 supply_register (regno
, (buf
+ sizeof (PTRACE_XFER_TYPE
)
1235 - register_size (regno
)));
1237 supply_register (regno
, buf
);
1242 /* Fetch all registers, or just one, from the child process. */
1244 usr_fetch_inferior_registers (int regno
)
1246 if (regno
== -1 || regno
== 0)
1247 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
1248 fetch_register (regno
);
1250 fetch_register (regno
);
1253 /* Store our register values back into the inferior.
1254 If REGNO is -1, do this for all registers.
1255 Otherwise, REGNO specifies which register (so we can save time). */
1257 usr_store_inferior_registers (int regno
)
1265 if (regno
>= the_low_target
.num_regs
)
1268 if ((*the_low_target
.cannot_store_register
) (regno
) == 1)
1271 regaddr
= register_addr (regno
);
1275 size
= (register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
1276 & - sizeof (PTRACE_XFER_TYPE
);
1277 buf
= alloca (size
);
1278 memset (buf
, 0, size
);
1279 if (the_low_target
.left_pad_xfer
1280 && register_size (regno
) < sizeof (PTRACE_XFER_TYPE
))
1281 collect_register (regno
, (buf
+ sizeof (PTRACE_XFER_TYPE
)
1282 - register_size (regno
)));
1284 collect_register (regno
, buf
);
1285 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
1288 ptrace (PTRACE_POKEUSER
, inferior_pid
, (PTRACE_ARG3_TYPE
) regaddr
,
1289 *(PTRACE_XFER_TYPE
*) (buf
+ i
));
1292 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
1294 char *err
= strerror (errno
);
1295 char *msg
= alloca (strlen (err
) + 128);
1296 sprintf (msg
, "writing register %d: %s",
1302 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
1306 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
1307 usr_store_inferior_registers (regno
);
1309 #endif /* HAVE_LINUX_USRREGS */
1313 #ifdef HAVE_LINUX_REGSETS
1316 regsets_fetch_inferior_registers ()
1318 struct regset_info
*regset
;
1319 int saw_general_regs
= 0;
1321 regset
= target_regsets
;
1323 while (regset
->size
>= 0)
1328 if (regset
->size
== 0)
1334 buf
= malloc (regset
->size
);
1335 res
= ptrace (regset
->get_request
, inferior_pid
, 0, buf
);
1340 /* If we get EIO on the first regset, do not try regsets again.
1341 If we get EIO on a later regset, disable that regset. */
1342 if (regset
== target_regsets
)
1356 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%ld",
1361 else if (regset
->type
== GENERAL_REGS
)
1362 saw_general_regs
= 1;
1363 regset
->store_function (buf
);
1366 if (saw_general_regs
)
1373 regsets_store_inferior_registers ()
1375 struct regset_info
*regset
;
1376 int saw_general_regs
= 0;
1378 regset
= target_regsets
;
1380 while (regset
->size
>= 0)
1385 if (regset
->size
== 0)
1391 buf
= malloc (regset
->size
);
1393 /* First fill the buffer with the current register set contents,
1394 in case there are any items in the kernel's regset that are
1395 not in gdbserver's regcache. */
1396 res
= ptrace (regset
->get_request
, inferior_pid
, 0, buf
);
1400 /* Then overlay our cached registers on that. */
1401 regset
->fill_function (buf
);
1403 /* Only now do we write the register set. */
1404 res
= ptrace (regset
->set_request
, inferior_pid
, 0, buf
);
1411 /* If we get EIO on the first regset, do not try regsets again.
1412 If we get EIO on a later regset, disable that regset. */
1413 if (regset
== target_regsets
)
1426 perror ("Warning: ptrace(regsets_store_inferior_registers)");
1429 else if (regset
->type
== GENERAL_REGS
)
1430 saw_general_regs
= 1;
1434 if (saw_general_regs
)
1441 #endif /* HAVE_LINUX_REGSETS */
1445 linux_fetch_registers (int regno
)
1447 #ifdef HAVE_LINUX_REGSETS
1450 if (regsets_fetch_inferior_registers () == 0)
1454 #ifdef HAVE_LINUX_USRREGS
1455 usr_fetch_inferior_registers (regno
);
1460 linux_store_registers (int regno
)
1462 #ifdef HAVE_LINUX_REGSETS
1465 if (regsets_store_inferior_registers () == 0)
1469 #ifdef HAVE_LINUX_USRREGS
1470 usr_store_inferior_registers (regno
);
1475 /* Copy LEN bytes from inferior's memory starting at MEMADDR
1476 to debugger memory starting at MYADDR. */
1479 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
1482 /* Round starting address down to longword boundary. */
1483 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
1484 /* Round ending address up; get number of longwords that makes. */
1486 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
1487 / sizeof (PTRACE_XFER_TYPE
);
1488 /* Allocate buffer of that many longwords. */
1489 register PTRACE_XFER_TYPE
*buffer
1490 = (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
1492 /* Read all the longwords */
1493 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
1496 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, inferior_pid
, (PTRACE_ARG3_TYPE
) addr
, 0);
1501 /* Copy appropriate bytes out of the buffer. */
1502 memcpy (myaddr
, (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)), len
);
1507 /* Copy LEN bytes of data from debugger memory at MYADDR
1508 to inferior's memory at MEMADDR.
1509 On failure (cannot write the inferior)
1510 returns the value of errno. */
1513 linux_write_memory (CORE_ADDR memaddr
, const unsigned char *myaddr
, int len
)
1516 /* Round starting address down to longword boundary. */
1517 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
1518 /* Round ending address up; get number of longwords that makes. */
1520 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1) / sizeof (PTRACE_XFER_TYPE
);
1521 /* Allocate buffer of that many longwords. */
1522 register PTRACE_XFER_TYPE
*buffer
= (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
1527 fprintf (stderr
, "Writing %02x to %08lx\n", (unsigned)myaddr
[0], (long)memaddr
);
1530 /* Fill start and end extra bytes of buffer with existing memory data. */
1532 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, inferior_pid
,
1533 (PTRACE_ARG3_TYPE
) addr
, 0);
1538 = ptrace (PTRACE_PEEKTEXT
, inferior_pid
,
1539 (PTRACE_ARG3_TYPE
) (addr
+ (count
- 1)
1540 * sizeof (PTRACE_XFER_TYPE
)),
1544 /* Copy data to be written over corresponding part of buffer */
1546 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)), myaddr
, len
);
1548 /* Write the entire buffer. */
1550 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
1553 ptrace (PTRACE_POKETEXT
, inferior_pid
, (PTRACE_ARG3_TYPE
) addr
, buffer
[i
]);
1562 linux_look_up_symbols (void)
1564 #ifdef USE_THREAD_DB
1568 using_threads
= thread_db_init ();
1573 linux_request_interrupt (void)
1575 extern unsigned long signal_pid
;
1577 if (cont_thread
!= 0 && cont_thread
!= -1)
1579 struct process_info
*process
;
1581 process
= get_thread_process (current_inferior
);
1582 kill_lwp (process
->lwpid
, SIGINT
);
1585 kill_lwp (signal_pid
, SIGINT
);
1588 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
1589 to debugger memory starting at MYADDR. */
1592 linux_read_auxv (CORE_ADDR offset
, unsigned char *myaddr
, unsigned int len
)
1594 char filename
[PATH_MAX
];
1597 snprintf (filename
, sizeof filename
, "/proc/%ld/auxv", inferior_pid
);
1599 fd
= open (filename
, O_RDONLY
);
1603 if (offset
!= (CORE_ADDR
) 0
1604 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
1607 n
= read (fd
, myaddr
, len
);
1614 /* These watchpoint related wrapper functions simply pass on the function call
1615 if the target has registered a corresponding function. */
1618 linux_insert_watchpoint (char type
, CORE_ADDR addr
, int len
)
1620 if (the_low_target
.insert_watchpoint
!= NULL
)
1621 return the_low_target
.insert_watchpoint (type
, addr
, len
);
1623 /* Unsupported (see target.h). */
1628 linux_remove_watchpoint (char type
, CORE_ADDR addr
, int len
)
1630 if (the_low_target
.remove_watchpoint
!= NULL
)
1631 return the_low_target
.remove_watchpoint (type
, addr
, len
);
1633 /* Unsupported (see target.h). */
1638 linux_stopped_by_watchpoint (void)
1640 if (the_low_target
.stopped_by_watchpoint
!= NULL
)
1641 return the_low_target
.stopped_by_watchpoint ();
1647 linux_stopped_data_address (void)
1649 if (the_low_target
.stopped_data_address
!= NULL
)
1650 return the_low_target
.stopped_data_address ();
1655 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
1656 #if defined(__mcoldfire__)
1657 /* These should really be defined in the kernel's ptrace.h header. */
1658 #define PT_TEXT_ADDR 49*4
1659 #define PT_DATA_ADDR 50*4
1660 #define PT_TEXT_END_ADDR 51*4
1663 /* Under uClinux, programs are loaded at non-zero offsets, which we need
1664 to tell gdb about. */
1667 linux_read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
1669 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
1670 unsigned long text
, text_end
, data
;
1671 int pid
= get_thread_process (current_inferior
)->head
.id
;
1675 text
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_ADDR
, 0);
1676 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_END_ADDR
, 0);
1677 data
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_DATA_ADDR
, 0);
1681 /* Both text and data offsets produced at compile-time (and so
1682 used by gdb) are relative to the beginning of the program,
1683 with the data segment immediately following the text segment.
1684 However, the actual runtime layout in memory may put the data
1685 somewhere else, so when we send gdb a data base-address, we
1686 use the real data base address and subtract the compile-time
1687 data base-address from it (which is just the length of the
1688 text segment). BSS immediately follows data in both
1691 *data_p
= data
- (text_end
- text
);
1701 linux_arch_string (void)
1703 return the_low_target
.arch_string
;
1706 static struct target_ops linux_target_ops
= {
1707 linux_create_inferior
,
1715 linux_fetch_registers
,
1716 linux_store_registers
,
1719 linux_look_up_symbols
,
1720 linux_request_interrupt
,
1722 linux_insert_watchpoint
,
1723 linux_remove_watchpoint
,
1724 linux_stopped_by_watchpoint
,
1725 linux_stopped_data_address
,
1726 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
1731 #ifdef USE_THREAD_DB
1732 thread_db_get_tls_address
,
1740 linux_init_signals ()
1742 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
1743 to find what the cancel signal actually is. */
1744 signal (__SIGRTMIN
+1, SIG_IGN
);
1748 initialize_low (void)
1751 set_target_ops (&linux_target_ops
);
1752 set_breakpoint_data (the_low_target
.breakpoint
,
1753 the_low_target
.breakpoint_len
);
1755 linux_init_signals ();