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, 2010 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>
43 /* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h
44 then ELFMAG0 will have been defined. If it didn't get included by
45 gdb_proc_service.h then including it will likely introduce a duplicate
46 definition of elf_fpregset_t. */
51 #define SPUFS_MAGIC 0x23c9b64e
54 #ifndef PTRACE_GETSIGINFO
55 # define PTRACE_GETSIGINFO 0x4202
56 # define PTRACE_SETSIGINFO 0x4203
63 /* If the system headers did not provide the constants, hard-code the normal
65 #ifndef PTRACE_EVENT_FORK
67 #define PTRACE_SETOPTIONS 0x4200
68 #define PTRACE_GETEVENTMSG 0x4201
70 /* options set using PTRACE_SETOPTIONS */
71 #define PTRACE_O_TRACESYSGOOD 0x00000001
72 #define PTRACE_O_TRACEFORK 0x00000002
73 #define PTRACE_O_TRACEVFORK 0x00000004
74 #define PTRACE_O_TRACECLONE 0x00000008
75 #define PTRACE_O_TRACEEXEC 0x00000010
76 #define PTRACE_O_TRACEVFORKDONE 0x00000020
77 #define PTRACE_O_TRACEEXIT 0x00000040
79 /* Wait extended result codes for the above trace options. */
80 #define PTRACE_EVENT_FORK 1
81 #define PTRACE_EVENT_VFORK 2
82 #define PTRACE_EVENT_CLONE 3
83 #define PTRACE_EVENT_EXEC 4
84 #define PTRACE_EVENT_VFORK_DONE 5
85 #define PTRACE_EVENT_EXIT 6
87 #endif /* PTRACE_EVENT_FORK */
89 /* We can't always assume that this flag is available, but all systems
90 with the ptrace event handlers also have __WALL, so it's safe to use
93 #define __WALL 0x40000000 /* Wait for any child. */
97 #define W_STOPCODE(sig) ((sig) << 8 | 0x7f)
101 #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
106 /* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
107 representation of the thread ID.
109 ``all_lwps'' is keyed by the process ID - which on Linux is (presently)
110 the same as the LWP ID.
112 ``all_processes'' is keyed by the "overall process ID", which
113 GNU/Linux calls tgid, "thread group ID". */
115 struct inferior_list all_lwps
;
117 /* A list of all unknown processes which receive stop signals. Some other
118 process will presumably claim each of these as forked children
121 struct inferior_list stopped_pids
;
123 /* FIXME this is a bit of a hack, and could be removed. */
124 int stopping_threads
;
126 /* FIXME make into a target method? */
127 int using_threads
= 1;
129 /* This flag is true iff we've just created or attached to our first
130 inferior but it has not stopped yet. As soon as it does, we need
131 to call the low target's arch_setup callback. Doing this only on
132 the first inferior avoids reinializing the architecture on every
133 inferior, and avoids messing with the register caches of the
134 already running inferiors. NOTE: this assumes all inferiors under
135 control of gdbserver have the same architecture. */
136 static int new_inferior
;
138 static void linux_resume_one_lwp (struct lwp_info
*lwp
,
139 int step
, int signal
, siginfo_t
*info
);
140 static void linux_resume (struct thread_resume
*resume_info
, size_t n
);
141 static void stop_all_lwps (void);
142 static int linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
);
143 static int check_removed_breakpoint (struct lwp_info
*event_child
);
144 static void *add_lwp (ptid_t ptid
);
145 static int linux_stopped_by_watchpoint (void);
146 static void mark_lwp_dead (struct lwp_info
*lwp
, int wstat
);
147 static int linux_core_of_thread (ptid_t ptid
);
149 struct pending_signals
153 struct pending_signals
*prev
;
156 #define PTRACE_ARG3_TYPE void *
157 #define PTRACE_ARG4_TYPE void *
158 #define PTRACE_XFER_TYPE long
160 #ifdef HAVE_LINUX_REGSETS
161 static char *disabled_regsets
;
162 static int num_regsets
;
165 /* The read/write ends of the pipe registered as waitable file in the
167 static int linux_event_pipe
[2] = { -1, -1 };
169 /* True if we're currently in async mode. */
170 #define target_is_async_p() (linux_event_pipe[0] != -1)
172 static void send_sigstop (struct inferior_list_entry
*entry
);
173 static void wait_for_sigstop (struct inferior_list_entry
*entry
);
175 /* Accepts an integer PID; Returns a string representing a file that
176 can be opened to get info for the child process.
177 Space for the result is malloc'd, caller must free. */
180 linux_child_pid_to_exec_file (int pid
)
184 name1
= xmalloc (MAXPATHLEN
);
185 name2
= xmalloc (MAXPATHLEN
);
186 memset (name2
, 0, MAXPATHLEN
);
188 sprintf (name1
, "/proc/%d/exe", pid
);
189 if (readlink (name1
, name2
, MAXPATHLEN
) > 0)
201 /* Return non-zero if HEADER is a 64-bit ELF file. */
204 elf_64_header_p (const Elf64_Ehdr
*header
)
206 return (header
->e_ident
[EI_MAG0
] == ELFMAG0
207 && header
->e_ident
[EI_MAG1
] == ELFMAG1
208 && header
->e_ident
[EI_MAG2
] == ELFMAG2
209 && header
->e_ident
[EI_MAG3
] == ELFMAG3
210 && header
->e_ident
[EI_CLASS
] == ELFCLASS64
);
213 /* Return non-zero if FILE is a 64-bit ELF file,
214 zero if the file is not a 64-bit ELF file,
215 and -1 if the file is not accessible or doesn't exist. */
218 elf_64_file_p (const char *file
)
223 fd
= open (file
, O_RDONLY
);
227 if (read (fd
, &header
, sizeof (header
)) != sizeof (header
))
234 return elf_64_header_p (&header
);
238 delete_lwp (struct lwp_info
*lwp
)
240 remove_thread (get_lwp_thread (lwp
));
241 remove_inferior (&all_lwps
, &lwp
->head
);
242 free (lwp
->arch_private
);
246 /* Add a process to the common process list, and set its private
249 static struct process_info
*
250 linux_add_process (int pid
, int attached
)
252 struct process_info
*proc
;
254 /* Is this the first process? If so, then set the arch. */
255 if (all_processes
.head
== NULL
)
258 proc
= add_process (pid
, attached
);
259 proc
->private = xcalloc (1, sizeof (*proc
->private));
261 if (the_low_target
.new_process
!= NULL
)
262 proc
->private->arch_private
= the_low_target
.new_process ();
267 /* Remove a process from the common process list,
268 also freeing all private data. */
271 linux_remove_process (struct process_info
*process
)
273 struct process_info_private
*priv
= process
->private;
275 free (priv
->arch_private
);
277 remove_process (process
);
280 /* Wrapper function for waitpid which handles EINTR, and emulates
281 __WALL for systems where that is not available. */
284 my_waitpid (int pid
, int *status
, int flags
)
289 fprintf (stderr
, "my_waitpid (%d, 0x%x)\n", pid
, flags
);
293 sigset_t block_mask
, org_mask
, wake_mask
;
296 wnohang
= (flags
& WNOHANG
) != 0;
297 flags
&= ~(__WALL
| __WCLONE
);
300 /* Block all signals while here. This avoids knowing about
301 LinuxThread's signals. */
302 sigfillset (&block_mask
);
303 sigprocmask (SIG_BLOCK
, &block_mask
, &org_mask
);
305 /* ... except during the sigsuspend below. */
306 sigemptyset (&wake_mask
);
310 /* Since all signals are blocked, there's no need to check
312 ret
= waitpid (pid
, status
, flags
);
315 if (ret
== -1 && out_errno
!= ECHILD
)
320 if (flags
& __WCLONE
)
322 /* We've tried both flavors now. If WNOHANG is set,
323 there's nothing else to do, just bail out. */
328 fprintf (stderr
, "blocking\n");
330 /* Block waiting for signals. */
331 sigsuspend (&wake_mask
);
337 sigprocmask (SIG_SETMASK
, &org_mask
, NULL
);
342 ret
= waitpid (pid
, status
, flags
);
343 while (ret
== -1 && errno
== EINTR
);
348 fprintf (stderr
, "my_waitpid (%d, 0x%x): status(%x), %d\n",
349 pid
, flags
, status
? *status
: -1, ret
);
355 /* Handle a GNU/Linux extended wait response. If we see a clone
356 event, we need to add the new LWP to our list (and not report the
357 trap to higher layers). */
360 handle_extended_wait (struct lwp_info
*event_child
, int wstat
)
362 int event
= wstat
>> 16;
363 struct lwp_info
*new_lwp
;
365 if (event
== PTRACE_EVENT_CLONE
)
368 unsigned long new_pid
;
369 int ret
, status
= W_STOPCODE (SIGSTOP
);
371 ptrace (PTRACE_GETEVENTMSG
, lwpid_of (event_child
), 0, &new_pid
);
373 /* If we haven't already seen the new PID stop, wait for it now. */
374 if (! pull_pid_from_list (&stopped_pids
, new_pid
))
376 /* The new child has a pending SIGSTOP. We can't affect it until it
377 hits the SIGSTOP, but we're already attached. */
379 ret
= my_waitpid (new_pid
, &status
, __WALL
);
382 perror_with_name ("waiting for new child");
383 else if (ret
!= new_pid
)
384 warning ("wait returned unexpected PID %d", ret
);
385 else if (!WIFSTOPPED (status
))
386 warning ("wait returned unexpected status 0x%x", status
);
389 ptrace (PTRACE_SETOPTIONS
, new_pid
, 0, (PTRACE_ARG4_TYPE
) PTRACE_O_TRACECLONE
);
391 ptid
= ptid_build (pid_of (event_child
), new_pid
, 0);
392 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
393 add_thread (ptid
, new_lwp
);
395 /* Either we're going to immediately resume the new thread
396 or leave it stopped. linux_resume_one_lwp is a nop if it
397 thinks the thread is currently running, so set this first
398 before calling linux_resume_one_lwp. */
399 new_lwp
->stopped
= 1;
401 /* Normally we will get the pending SIGSTOP. But in some cases
402 we might get another signal delivered to the group first.
403 If we do get another signal, be sure not to lose it. */
404 if (WSTOPSIG (status
) == SIGSTOP
)
406 if (! stopping_threads
)
407 linux_resume_one_lwp (new_lwp
, 0, 0, NULL
);
411 new_lwp
->stop_expected
= 1;
412 if (stopping_threads
)
414 new_lwp
->status_pending_p
= 1;
415 new_lwp
->status_pending
= status
;
418 /* Pass the signal on. This is what GDB does - except
419 shouldn't we really report it instead? */
420 linux_resume_one_lwp (new_lwp
, 0, WSTOPSIG (status
), NULL
);
423 /* Always resume the current thread. If we are stopping
424 threads, it will have a pending SIGSTOP; we may as well
426 linux_resume_one_lwp (event_child
, event_child
->stepping
, 0, NULL
);
430 /* This function should only be called if the process got a SIGTRAP.
431 The SIGTRAP could mean several things.
433 On i386, where decr_pc_after_break is non-zero:
434 If we were single-stepping this process using PTRACE_SINGLESTEP,
435 we will get only the one SIGTRAP (even if the instruction we
436 stepped over was a breakpoint). The value of $eip will be the
438 If we continue the process using PTRACE_CONT, we will get a
439 SIGTRAP when we hit a breakpoint. The value of $eip will be
440 the instruction after the breakpoint (i.e. needs to be
441 decremented). If we report the SIGTRAP to GDB, we must also
442 report the undecremented PC. If we cancel the SIGTRAP, we
443 must resume at the decremented PC.
445 (Presumably, not yet tested) On a non-decr_pc_after_break machine
446 with hardware or kernel single-step:
447 If we single-step over a breakpoint instruction, our PC will
448 point at the following instruction. If we continue and hit a
449 breakpoint instruction, our PC will point at the breakpoint
455 struct regcache
*regcache
= get_thread_regcache (current_inferior
, 1);
456 CORE_ADDR stop_pc
= (*the_low_target
.get_pc
) (regcache
);
458 if (! get_thread_lwp (current_inferior
)->stepping
459 && WSTOPSIG (get_thread_lwp (current_inferior
)->last_status
) == SIGTRAP
)
460 stop_pc
-= the_low_target
.decr_pc_after_break
;
463 fprintf (stderr
, "stop pc is 0x%lx\n", (long) stop_pc
);
469 add_lwp (ptid_t ptid
)
471 struct lwp_info
*lwp
;
473 lwp
= (struct lwp_info
*) xmalloc (sizeof (*lwp
));
474 memset (lwp
, 0, sizeof (*lwp
));
478 if (the_low_target
.new_thread
!= NULL
)
479 lwp
->arch_private
= the_low_target
.new_thread ();
481 add_inferior_to_list (&all_lwps
, &lwp
->head
);
486 /* Start an inferior process and returns its pid.
487 ALLARGS is a vector of program-name and args. */
490 linux_create_inferior (char *program
, char **allargs
)
492 struct lwp_info
*new_lwp
;
496 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
502 perror_with_name ("fork");
506 ptrace (PTRACE_TRACEME
, 0, 0, 0);
508 #ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
509 signal (__SIGRTMIN
+ 1, SIG_DFL
);
514 execv (program
, allargs
);
516 execvp (program
, allargs
);
518 fprintf (stderr
, "Cannot exec %s: %s.\n", program
,
524 linux_add_process (pid
, 0);
526 ptid
= ptid_build (pid
, pid
, 0);
527 new_lwp
= add_lwp (ptid
);
528 add_thread (ptid
, new_lwp
);
529 new_lwp
->must_set_ptrace_flags
= 1;
534 /* Attach to an inferior process. */
537 linux_attach_lwp_1 (unsigned long lwpid
, int initial
)
540 struct lwp_info
*new_lwp
;
542 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) != 0)
546 /* If we fail to attach to an LWP, just warn. */
547 fprintf (stderr
, "Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
548 strerror (errno
), errno
);
553 /* If we fail to attach to a process, report an error. */
554 error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
555 strerror (errno
), errno
);
559 /* NOTE/FIXME: This lwp might have not been the tgid. */
560 ptid
= ptid_build (lwpid
, lwpid
, 0);
563 /* Note that extracting the pid from the current inferior is
564 safe, since we're always called in the context of the same
565 process as this new thread. */
566 int pid
= pid_of (get_thread_lwp (current_inferior
));
567 ptid
= ptid_build (pid
, lwpid
, 0);
570 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
571 add_thread (ptid
, new_lwp
);
573 /* We need to wait for SIGSTOP before being able to make the next
574 ptrace call on this LWP. */
575 new_lwp
->must_set_ptrace_flags
= 1;
577 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
580 There are several cases to consider here:
582 1) gdbserver has already attached to the process and is being notified
583 of a new thread that is being created.
584 In this case we should ignore that SIGSTOP and resume the process.
585 This is handled below by setting stop_expected = 1.
587 2) This is the first thread (the process thread), and we're attaching
588 to it via attach_inferior.
589 In this case we want the process thread to stop.
590 This is handled by having linux_attach clear stop_expected after
592 ??? If the process already has several threads we leave the other
595 3) GDB is connecting to gdbserver and is requesting an enumeration of all
597 In this case we want the thread to stop.
598 FIXME: This case is currently not properly handled.
599 We should wait for the SIGSTOP but don't. Things work apparently
600 because enough time passes between when we ptrace (ATTACH) and when
601 gdb makes the next ptrace call on the thread.
603 On the other hand, if we are currently trying to stop all threads, we
604 should treat the new thread as if we had sent it a SIGSTOP. This works
605 because we are guaranteed that the add_lwp call above added us to the
606 end of the list, and so the new thread has not yet reached
607 wait_for_sigstop (but will). */
608 if (! stopping_threads
)
609 new_lwp
->stop_expected
= 1;
613 linux_attach_lwp (unsigned long lwpid
)
615 linux_attach_lwp_1 (lwpid
, 0);
619 linux_attach (unsigned long pid
)
621 struct lwp_info
*lwp
;
623 linux_attach_lwp_1 (pid
, 1);
625 linux_add_process (pid
, 1);
629 /* Don't ignore the initial SIGSTOP if we just attached to this
630 process. It will be collected by wait shortly. */
631 lwp
= (struct lwp_info
*) find_inferior_id (&all_lwps
,
632 ptid_build (pid
, pid
, 0));
633 lwp
->stop_expected
= 0;
646 second_thread_of_pid_p (struct inferior_list_entry
*entry
, void *args
)
648 struct counter
*counter
= args
;
650 if (ptid_get_pid (entry
->id
) == counter
->pid
)
652 if (++counter
->count
> 1)
660 last_thread_of_process_p (struct thread_info
*thread
)
662 ptid_t ptid
= ((struct inferior_list_entry
*)thread
)->id
;
663 int pid
= ptid_get_pid (ptid
);
664 struct counter counter
= { pid
, 0 };
666 return (find_inferior (&all_threads
,
667 second_thread_of_pid_p
, &counter
) == NULL
);
670 /* Kill the inferior lwp. */
673 linux_kill_one_lwp (struct inferior_list_entry
*entry
, void *args
)
675 struct thread_info
*thread
= (struct thread_info
*) entry
;
676 struct lwp_info
*lwp
= get_thread_lwp (thread
);
678 int pid
= * (int *) args
;
680 if (ptid_get_pid (entry
->id
) != pid
)
683 /* We avoid killing the first thread here, because of a Linux kernel (at
684 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
685 the children get a chance to be reaped, it will remain a zombie
688 if (lwpid_of (lwp
) == pid
)
691 fprintf (stderr
, "lkop: is last of process %s\n",
692 target_pid_to_str (entry
->id
));
696 /* If we're killing a running inferior, make sure it is stopped
697 first, as PTRACE_KILL will not work otherwise. */
699 send_sigstop (&lwp
->head
);
703 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
705 /* Make sure it died. The loop is most likely unnecessary. */
706 pid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
707 } while (pid
> 0 && WIFSTOPPED (wstat
));
715 struct process_info
*process
;
716 struct lwp_info
*lwp
;
717 struct thread_info
*thread
;
721 process
= find_process_pid (pid
);
725 find_inferior (&all_threads
, linux_kill_one_lwp
, &pid
);
727 /* See the comment in linux_kill_one_lwp. We did not kill the first
728 thread in the list, so do so now. */
729 lwp
= find_lwp_pid (pid_to_ptid (pid
));
730 thread
= get_lwp_thread (lwp
);
733 fprintf (stderr
, "lk_1: killing lwp %ld, for pid: %d\n",
734 lwpid_of (lwp
), pid
);
736 /* If we're killing a running inferior, make sure it is stopped
737 first, as PTRACE_KILL will not work otherwise. */
739 send_sigstop (&lwp
->head
);
743 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
745 /* Make sure it died. The loop is most likely unnecessary. */
746 lwpid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
747 } while (lwpid
> 0 && WIFSTOPPED (wstat
));
750 thread_db_free (process
, 0);
753 linux_remove_process (process
);
758 linux_detach_one_lwp (struct inferior_list_entry
*entry
, void *args
)
760 struct thread_info
*thread
= (struct thread_info
*) entry
;
761 struct lwp_info
*lwp
= get_thread_lwp (thread
);
762 int pid
= * (int *) args
;
764 if (ptid_get_pid (entry
->id
) != pid
)
767 /* If we're detaching from a running inferior, make sure it is
768 stopped first, as PTRACE_DETACH will not work otherwise. */
771 int lwpid
= lwpid_of (lwp
);
773 stopping_threads
= 1;
774 send_sigstop (&lwp
->head
);
776 /* If this detects a new thread through a clone event, the new
777 thread is appended to the end of the lwp list, so we'll
778 eventually detach from it. */
779 wait_for_sigstop (&lwp
->head
);
780 stopping_threads
= 0;
782 /* If LWP exits while we're trying to stop it, there's nothing
784 lwp
= find_lwp_pid (pid_to_ptid (lwpid
));
789 /* Make sure the process isn't stopped at a breakpoint that's
791 check_removed_breakpoint (lwp
);
793 /* If this process is stopped but is expecting a SIGSTOP, then make
794 sure we take care of that now. This isn't absolutely guaranteed
795 to collect the SIGSTOP, but is fairly likely to. */
796 if (lwp
->stop_expected
)
799 /* Clear stop_expected, so that the SIGSTOP will be reported. */
800 lwp
->stop_expected
= 0;
802 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
803 linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
806 /* Flush any pending changes to the process's registers. */
807 regcache_invalidate_one ((struct inferior_list_entry
*)
808 get_lwp_thread (lwp
));
810 /* Finally, let it resume. */
811 ptrace (PTRACE_DETACH
, lwpid_of (lwp
), 0, 0);
818 any_thread_of (struct inferior_list_entry
*entry
, void *args
)
822 if (ptid_get_pid (entry
->id
) == *pid_p
)
829 linux_detach (int pid
)
831 struct process_info
*process
;
833 process
= find_process_pid (pid
);
838 thread_db_free (process
, 1);
842 (struct thread_info
*) find_inferior (&all_threads
, any_thread_of
, &pid
);
844 delete_all_breakpoints ();
845 find_inferior (&all_threads
, linux_detach_one_lwp
, &pid
);
846 linux_remove_process (process
);
854 struct process_info
*process
;
856 process
= find_process_pid (pid
);
861 ret
= my_waitpid (pid
, &status
, 0);
862 if (WIFEXITED (status
) || WIFSIGNALED (status
))
864 } while (ret
!= -1 || errno
!= ECHILD
);
867 /* Return nonzero if the given thread is still alive. */
869 linux_thread_alive (ptid_t ptid
)
871 struct lwp_info
*lwp
= find_lwp_pid (ptid
);
873 /* We assume we always know if a thread exits. If a whole process
874 exited but we still haven't been able to report it to GDB, we'll
875 hold on to the last lwp of the dead process. */
882 /* Return nonzero if this process stopped at a breakpoint which
883 no longer appears to be inserted. Also adjust the PC
884 appropriately to resume where the breakpoint used to be. */
886 check_removed_breakpoint (struct lwp_info
*event_child
)
889 struct thread_info
*saved_inferior
;
890 struct regcache
*regcache
;
892 if (event_child
->pending_is_breakpoint
== 0)
896 fprintf (stderr
, "Checking for breakpoint in lwp %ld.\n",
897 lwpid_of (event_child
));
899 saved_inferior
= current_inferior
;
900 current_inferior
= get_lwp_thread (event_child
);
901 regcache
= get_thread_regcache (current_inferior
, 1);
902 stop_pc
= get_stop_pc ();
904 /* If the PC has changed since we stopped, then we shouldn't do
905 anything. This happens if, for instance, GDB handled the
906 decr_pc_after_break subtraction itself. */
907 if (stop_pc
!= event_child
->pending_stop_pc
)
910 fprintf (stderr
, "Ignoring, PC was changed. Old PC was 0x%08llx\n",
911 event_child
->pending_stop_pc
);
913 event_child
->pending_is_breakpoint
= 0;
914 current_inferior
= saved_inferior
;
918 /* If the breakpoint is still there, we will report hitting it. */
919 if ((*the_low_target
.breakpoint_at
) (stop_pc
))
922 fprintf (stderr
, "Ignoring, breakpoint is still present.\n");
923 current_inferior
= saved_inferior
;
928 fprintf (stderr
, "Removed breakpoint.\n");
930 /* For decr_pc_after_break targets, here is where we perform the
931 decrement. We go immediately from this function to resuming,
932 and can not safely call get_stop_pc () again. */
933 if (the_low_target
.set_pc
!= NULL
)
936 fprintf (stderr
, "Set pc to 0x%lx\n", (long) stop_pc
);
937 (*the_low_target
.set_pc
) (regcache
, stop_pc
);
940 /* We consumed the pending SIGTRAP. */
941 event_child
->pending_is_breakpoint
= 0;
942 event_child
->status_pending_p
= 0;
943 event_child
->status_pending
= 0;
945 current_inferior
= saved_inferior
;
949 /* Return 1 if this lwp has an interesting status pending. This
950 function may silently resume an inferior lwp. */
952 status_pending_p (struct inferior_list_entry
*entry
, void *arg
)
954 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
955 ptid_t ptid
= * (ptid_t
*) arg
;
957 /* Check if we're only interested in events from a specific process
959 if (!ptid_equal (minus_one_ptid
, ptid
)
960 && ptid_get_pid (ptid
) != ptid_get_pid (lwp
->head
.id
))
963 if (lwp
->status_pending_p
&& !lwp
->suspended
)
964 if (check_removed_breakpoint (lwp
))
966 /* This thread was stopped at a breakpoint, and the breakpoint
967 is now gone. We were told to continue (or step...) all threads,
968 so GDB isn't trying to single-step past this breakpoint.
969 So instead of reporting the old SIGTRAP, pretend we got to
970 the breakpoint just after it was removed instead of just
971 before; resume the process. */
972 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
976 return (lwp
->status_pending_p
&& !lwp
->suspended
);
980 same_lwp (struct inferior_list_entry
*entry
, void *data
)
982 ptid_t ptid
= *(ptid_t
*) data
;
985 if (ptid_get_lwp (ptid
) != 0)
986 lwp
= ptid_get_lwp (ptid
);
988 lwp
= ptid_get_pid (ptid
);
990 if (ptid_get_lwp (entry
->id
) == lwp
)
997 find_lwp_pid (ptid_t ptid
)
999 return (struct lwp_info
*) find_inferior (&all_lwps
, same_lwp
, &ptid
);
1002 static struct lwp_info
*
1003 linux_wait_for_lwp (ptid_t ptid
, int *wstatp
, int options
)
1006 int to_wait_for
= -1;
1007 struct lwp_info
*child
= NULL
;
1010 fprintf (stderr
, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid
));
1012 if (ptid_equal (ptid
, minus_one_ptid
))
1013 to_wait_for
= -1; /* any child */
1015 to_wait_for
= ptid_get_lwp (ptid
); /* this lwp only */
1021 ret
= my_waitpid (to_wait_for
, wstatp
, options
);
1022 if (ret
== 0 || (ret
== -1 && errno
== ECHILD
&& (options
& WNOHANG
)))
1025 perror_with_name ("waitpid");
1028 && (!WIFSTOPPED (*wstatp
)
1029 || (WSTOPSIG (*wstatp
) != 32
1030 && WSTOPSIG (*wstatp
) != 33)))
1031 fprintf (stderr
, "Got an event from %d (%x)\n", ret
, *wstatp
);
1033 child
= find_lwp_pid (pid_to_ptid (ret
));
1035 /* If we didn't find a process, one of two things presumably happened:
1036 - A process we started and then detached from has exited. Ignore it.
1037 - A process we are controlling has forked and the new child's stop
1038 was reported to us by the kernel. Save its PID. */
1039 if (child
== NULL
&& WIFSTOPPED (*wstatp
))
1041 add_pid_to_list (&stopped_pids
, ret
);
1044 else if (child
== NULL
)
1048 child
->pending_is_breakpoint
= 0;
1050 child
->last_status
= *wstatp
;
1052 /* Architecture-specific setup after inferior is running.
1053 This needs to happen after we have attached to the inferior
1054 and it is stopped for the first time, but before we access
1055 any inferior registers. */
1058 the_low_target
.arch_setup ();
1059 #ifdef HAVE_LINUX_REGSETS
1060 memset (disabled_regsets
, 0, num_regsets
);
1066 && WIFSTOPPED (*wstatp
)
1067 && the_low_target
.get_pc
!= NULL
)
1069 struct thread_info
*saved_inferior
= current_inferior
;
1070 struct regcache
*regcache
= get_thread_regcache (current_inferior
, 1);
1073 current_inferior
= (struct thread_info
*)
1074 find_inferior_id (&all_threads
, child
->head
.id
);
1075 pc
= (*the_low_target
.get_pc
) (regcache
);
1076 fprintf (stderr
, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc
);
1077 current_inferior
= saved_inferior
;
1083 /* Wait for an event from child PID. If PID is -1, wait for any
1084 child. Store the stop status through the status pointer WSTAT.
1085 OPTIONS is passed to the waitpid call. Return 0 if no child stop
1086 event was found and OPTIONS contains WNOHANG. Return the PID of
1087 the stopped child otherwise. */
1090 linux_wait_for_event_1 (ptid_t ptid
, int *wstat
, int options
)
1093 struct lwp_info
*event_child
= NULL
;
1095 struct lwp_info
*requested_child
= NULL
;
1097 /* Check for a lwp with a pending status. */
1098 /* It is possible that the user changed the pending task's registers since
1099 it stopped. We correctly handle the change of PC if we hit a breakpoint
1100 (in check_removed_breakpoint); signals should be reported anyway. */
1102 if (ptid_equal (ptid
, minus_one_ptid
)
1103 || ptid_equal (pid_to_ptid (ptid_get_pid (ptid
)), ptid
))
1105 event_child
= (struct lwp_info
*)
1106 find_inferior (&all_lwps
, status_pending_p
, &ptid
);
1107 if (debug_threads
&& event_child
)
1108 fprintf (stderr
, "Got a pending child %ld\n", lwpid_of (event_child
));
1112 requested_child
= find_lwp_pid (ptid
);
1113 if (requested_child
->status_pending_p
1114 && !check_removed_breakpoint (requested_child
))
1115 event_child
= requested_child
;
1118 if (event_child
!= NULL
)
1121 fprintf (stderr
, "Got an event from pending child %ld (%04x)\n",
1122 lwpid_of (event_child
), event_child
->status_pending
);
1123 *wstat
= event_child
->status_pending
;
1124 event_child
->status_pending_p
= 0;
1125 event_child
->status_pending
= 0;
1126 current_inferior
= get_lwp_thread (event_child
);
1127 return lwpid_of (event_child
);
1130 /* We only enter this loop if no process has a pending wait status. Thus
1131 any action taken in response to a wait status inside this loop is
1132 responding as soon as we detect the status, not after any pending
1136 event_child
= linux_wait_for_lwp (ptid
, wstat
, options
);
1138 if ((options
& WNOHANG
) && event_child
== NULL
)
1141 if (event_child
== NULL
)
1142 error ("event from unknown child");
1144 current_inferior
= get_lwp_thread (event_child
);
1146 /* Check for thread exit. */
1147 if (! WIFSTOPPED (*wstat
))
1150 fprintf (stderr
, "LWP %ld exiting\n", lwpid_of (event_child
));
1152 /* If the last thread is exiting, just return. */
1153 if (last_thread_of_process_p (current_inferior
))
1156 fprintf (stderr
, "LWP %ld is last lwp of process\n",
1157 lwpid_of (event_child
));
1158 return lwpid_of (event_child
);
1161 delete_lwp (event_child
);
1165 current_inferior
= (struct thread_info
*) all_threads
.head
;
1167 fprintf (stderr
, "Current inferior is now %ld\n",
1168 lwpid_of (get_thread_lwp (current_inferior
)));
1172 current_inferior
= NULL
;
1174 fprintf (stderr
, "Current inferior is now <NULL>\n");
1177 /* If we were waiting for this particular child to do something...
1178 well, it did something. */
1179 if (requested_child
!= NULL
)
1180 return lwpid_of (event_child
);
1182 /* Wait for a more interesting event. */
1186 if (event_child
->must_set_ptrace_flags
)
1188 ptrace (PTRACE_SETOPTIONS
, lwpid_of (event_child
),
1189 0, (PTRACE_ARG4_TYPE
) PTRACE_O_TRACECLONE
);
1190 event_child
->must_set_ptrace_flags
= 0;
1193 if (WIFSTOPPED (*wstat
)
1194 && WSTOPSIG (*wstat
) == SIGSTOP
1195 && event_child
->stop_expected
)
1198 fprintf (stderr
, "Expected stop.\n");
1199 event_child
->stop_expected
= 0;
1200 linux_resume_one_lwp (event_child
, event_child
->stepping
, 0, NULL
);
1204 if (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) == SIGTRAP
1205 && *wstat
>> 16 != 0)
1207 handle_extended_wait (event_child
, *wstat
);
1211 /* If GDB is not interested in this signal, don't stop other
1212 threads, and don't report it to GDB. Just resume the
1213 inferior right away. We do this for threading-related
1214 signals as well as any that GDB specifically requested we
1215 ignore. But never ignore SIGSTOP if we sent it ourselves,
1216 and do not ignore signals when stepping - they may require
1217 special handling to skip the signal handler. */
1218 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
1220 if (WIFSTOPPED (*wstat
)
1221 && !event_child
->stepping
1223 #if defined (USE_THREAD_DB) && defined (__SIGRTMIN)
1224 (current_process ()->private->thread_db
!= NULL
1225 && (WSTOPSIG (*wstat
) == __SIGRTMIN
1226 || WSTOPSIG (*wstat
) == __SIGRTMIN
+ 1))
1229 (pass_signals
[target_signal_from_host (WSTOPSIG (*wstat
))]
1230 && (WSTOPSIG (*wstat
) != SIGSTOP
|| !stopping_threads
))))
1232 siginfo_t info
, *info_p
;
1235 fprintf (stderr
, "Ignored signal %d for LWP %ld.\n",
1236 WSTOPSIG (*wstat
), lwpid_of (event_child
));
1238 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (event_child
), 0, &info
) == 0)
1242 linux_resume_one_lwp (event_child
,
1243 event_child
->stepping
,
1244 WSTOPSIG (*wstat
), info_p
);
1248 /* If this event was not handled above, and is not a SIGTRAP,
1249 report it. SIGILL and SIGSEGV are also treated as traps in case
1250 a breakpoint is inserted at the current PC. */
1251 if (!WIFSTOPPED (*wstat
)
1252 || (WSTOPSIG (*wstat
) != SIGTRAP
&& WSTOPSIG (*wstat
) != SIGILL
1253 && WSTOPSIG (*wstat
) != SIGSEGV
))
1254 return lwpid_of (event_child
);
1256 /* If this target does not support breakpoints, we simply report the
1257 signal; it's of no concern to us. */
1258 if (the_low_target
.get_pc
== NULL
)
1259 return lwpid_of (event_child
);
1261 stop_pc
= get_stop_pc ();
1263 /* Only handle SIGILL or SIGSEGV if we've hit a recognized
1265 if (WSTOPSIG (*wstat
) != SIGTRAP
1266 && (event_child
->stepping
1267 || ! (*the_low_target
.breakpoint_at
) (stop_pc
)))
1268 return lwpid_of (event_child
);
1270 /* bp_reinsert will only be set if we were single-stepping.
1271 Notice that we will resume the process after hitting
1272 a gdbserver breakpoint; single-stepping to/over one
1273 is not supported (yet). */
1274 if (event_child
->bp_reinsert
!= 0)
1277 fprintf (stderr
, "Reinserted breakpoint.\n");
1278 reinsert_breakpoint (event_child
->bp_reinsert
);
1279 event_child
->bp_reinsert
= 0;
1281 /* Clear the single-stepping flag and SIGTRAP as we resume. */
1282 linux_resume_one_lwp (event_child
, 0, 0, NULL
);
1286 bp_status
= check_breakpoints (stop_pc
);
1291 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
1293 /* We hit one of our own breakpoints. We mark it as a pending
1294 breakpoint, so that check_removed_breakpoint () will do the PC
1295 adjustment for us at the appropriate time. */
1296 event_child
->pending_is_breakpoint
= 1;
1297 event_child
->pending_stop_pc
= stop_pc
;
1299 /* We may need to put the breakpoint back. We continue in the event
1300 loop instead of simply replacing the breakpoint right away,
1301 in order to not lose signals sent to the thread that hit the
1302 breakpoint. Unfortunately this increases the window where another
1303 thread could sneak past the removed breakpoint. For the current
1304 use of server-side breakpoints (thread creation) this is
1305 acceptable; but it needs to be considered before this breakpoint
1306 mechanism can be used in more general ways. For some breakpoints
1307 it may be necessary to stop all other threads, but that should
1308 be avoided where possible.
1310 If breakpoint_reinsert_addr is NULL, that means that we can
1311 use PTRACE_SINGLESTEP on this platform. Uninsert the breakpoint,
1312 mark it for reinsertion, and single-step.
1314 Otherwise, call the target function to figure out where we need
1315 our temporary breakpoint, create it, and continue executing this
1318 /* NOTE: we're lifting breakpoints in non-stop mode. This
1319 is currently only used for thread event breakpoints, so
1320 it isn't that bad as long as we have PTRACE_EVENT_CLONE
1323 /* No need to reinsert. */
1324 linux_resume_one_lwp (event_child
, 0, 0, NULL
);
1325 else if (the_low_target
.breakpoint_reinsert_addr
== NULL
)
1327 event_child
->bp_reinsert
= stop_pc
;
1328 uninsert_breakpoint (stop_pc
);
1329 linux_resume_one_lwp (event_child
, 1, 0, NULL
);
1333 reinsert_breakpoint_by_bp
1334 (stop_pc
, (*the_low_target
.breakpoint_reinsert_addr
) ());
1335 linux_resume_one_lwp (event_child
, 0, 0, NULL
);
1342 fprintf (stderr
, "Hit a non-gdbserver breakpoint.\n");
1344 /* If we were single-stepping, we definitely want to report the
1345 SIGTRAP. Although the single-step operation has completed,
1346 do not clear clear the stepping flag yet; we need to check it
1347 in wait_for_sigstop. */
1348 if (event_child
->stepping
)
1349 return lwpid_of (event_child
);
1351 /* A SIGTRAP that we can't explain. It may have been a breakpoint.
1352 Check if it is a breakpoint, and if so mark the process information
1353 accordingly. This will handle both the necessary fiddling with the
1354 PC on decr_pc_after_break targets and suppressing extra threads
1355 hitting a breakpoint if two hit it at once and then GDB removes it
1356 after the first is reported. Arguably it would be better to report
1357 multiple threads hitting breakpoints simultaneously, but the current
1358 remote protocol does not allow this. */
1359 if ((*the_low_target
.breakpoint_at
) (stop_pc
))
1361 event_child
->pending_is_breakpoint
= 1;
1362 event_child
->pending_stop_pc
= stop_pc
;
1365 return lwpid_of (event_child
);
1373 linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
)
1377 if (ptid_is_pid (ptid
))
1379 /* A request to wait for a specific tgid. This is not possible
1380 with waitpid, so instead, we wait for any child, and leave
1381 children we're not interested in right now with a pending
1382 status to report later. */
1383 wait_ptid
= minus_one_ptid
;
1392 event_pid
= linux_wait_for_event_1 (wait_ptid
, wstat
, options
);
1395 && ptid_is_pid (ptid
) && ptid_get_pid (ptid
) != event_pid
)
1397 struct lwp_info
*event_child
= find_lwp_pid (pid_to_ptid (event_pid
));
1399 if (! WIFSTOPPED (*wstat
))
1400 mark_lwp_dead (event_child
, *wstat
);
1403 event_child
->status_pending_p
= 1;
1404 event_child
->status_pending
= *wstat
;
1412 /* Wait for process, returns status. */
1415 linux_wait_1 (ptid_t ptid
,
1416 struct target_waitstatus
*ourstatus
, int target_options
)
1419 struct thread_info
*thread
= NULL
;
1420 struct lwp_info
*lwp
= NULL
;
1424 /* Translate generic target options into linux options. */
1426 if (target_options
& TARGET_WNOHANG
)
1430 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
1432 /* If we were only supposed to resume one thread, only wait for
1433 that thread - if it's still alive. If it died, however - which
1434 can happen if we're coming from the thread death case below -
1435 then we need to make sure we restart the other threads. We could
1436 pick a thread at random or restart all; restarting all is less
1439 && !ptid_equal (cont_thread
, null_ptid
)
1440 && !ptid_equal (cont_thread
, minus_one_ptid
))
1442 thread
= (struct thread_info
*) find_inferior_id (&all_threads
,
1445 /* No stepping, no signal - unless one is pending already, of course. */
1448 struct thread_resume resume_info
;
1449 resume_info
.thread
= minus_one_ptid
;
1450 resume_info
.kind
= resume_continue
;
1451 resume_info
.sig
= 0;
1452 linux_resume (&resume_info
, 1);
1458 pid
= linux_wait_for_event (ptid
, &w
, options
);
1459 if (pid
== 0) /* only if TARGET_WNOHANG */
1462 lwp
= get_thread_lwp (current_inferior
);
1464 /* If we are waiting for a particular child, and it exited,
1465 linux_wait_for_event will return its exit status. Similarly if
1466 the last child exited. If this is not the last child, however,
1467 do not report it as exited until there is a 'thread exited' response
1468 available in the remote protocol. Instead, just wait for another event.
1469 This should be safe, because if the thread crashed we will already
1470 have reported the termination signal to GDB; that should stop any
1471 in-progress stepping operations, etc.
1473 Report the exit status of the last thread to exit. This matches
1474 LinuxThreads' behavior. */
1476 if (last_thread_of_process_p (current_inferior
))
1478 if (WIFEXITED (w
) || WIFSIGNALED (w
))
1480 int pid
= pid_of (lwp
);
1481 struct process_info
*process
= find_process_pid (pid
);
1483 #ifdef USE_THREAD_DB
1484 thread_db_free (process
, 0);
1487 linux_remove_process (process
);
1489 current_inferior
= NULL
;
1493 ourstatus
->kind
= TARGET_WAITKIND_EXITED
;
1494 ourstatus
->value
.integer
= WEXITSTATUS (w
);
1497 fprintf (stderr
, "\nChild exited with retcode = %x \n", WEXITSTATUS (w
));
1501 ourstatus
->kind
= TARGET_WAITKIND_SIGNALLED
;
1502 ourstatus
->value
.sig
= target_signal_from_host (WTERMSIG (w
));
1505 fprintf (stderr
, "\nChild terminated with signal = %x \n", WTERMSIG (w
));
1509 return pid_to_ptid (pid
);
1514 if (!WIFSTOPPED (w
))
1518 /* In all-stop, stop all threads. Be careful to only do this if
1519 we're about to report an event to GDB. */
1523 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
1525 if (lwp
->suspended
&& WSTOPSIG (w
) == SIGSTOP
)
1527 /* A thread that has been requested to stop by GDB with vCont;t,
1528 and it stopped cleanly, so report as SIG0. The use of
1529 SIGSTOP is an implementation detail. */
1530 ourstatus
->value
.sig
= TARGET_SIGNAL_0
;
1532 else if (lwp
->suspended
&& WSTOPSIG (w
) != SIGSTOP
)
1534 /* A thread that has been requested to stop by GDB with vCont;t,
1535 but, it stopped for other reasons. Set stop_expected so the
1536 pending SIGSTOP is ignored and the LWP is resumed. */
1537 lwp
->stop_expected
= 1;
1538 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
1542 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
1546 fprintf (stderr
, "linux_wait ret = %s, %d, %d\n",
1547 target_pid_to_str (lwp
->head
.id
),
1549 ourstatus
->value
.sig
);
1551 return lwp
->head
.id
;
1554 /* Get rid of any pending event in the pipe. */
1556 async_file_flush (void)
1562 ret
= read (linux_event_pipe
[0], &buf
, 1);
1563 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
1566 /* Put something in the pipe, so the event loop wakes up. */
1568 async_file_mark (void)
1572 async_file_flush ();
1575 ret
= write (linux_event_pipe
[1], "+", 1);
1576 while (ret
== 0 || (ret
== -1 && errno
== EINTR
));
1578 /* Ignore EAGAIN. If the pipe is full, the event loop will already
1579 be awakened anyway. */
1583 linux_wait (ptid_t ptid
,
1584 struct target_waitstatus
*ourstatus
, int target_options
)
1589 fprintf (stderr
, "linux_wait: [%s]\n", target_pid_to_str (ptid
));
1591 /* Flush the async file first. */
1592 if (target_is_async_p ())
1593 async_file_flush ();
1595 event_ptid
= linux_wait_1 (ptid
, ourstatus
, target_options
);
1597 /* If at least one stop was reported, there may be more. A single
1598 SIGCHLD can signal more than one child stop. */
1599 if (target_is_async_p ()
1600 && (target_options
& TARGET_WNOHANG
) != 0
1601 && !ptid_equal (event_ptid
, null_ptid
))
1607 /* Send a signal to an LWP. */
1610 kill_lwp (unsigned long lwpid
, int signo
)
1612 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1613 fails, then we are not using nptl threads and we should be using kill. */
1617 static int tkill_failed
;
1624 ret
= syscall (__NR_tkill
, lwpid
, signo
);
1625 if (errno
!= ENOSYS
)
1632 return kill (lwpid
, signo
);
1636 send_sigstop (struct inferior_list_entry
*entry
)
1638 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1644 pid
= lwpid_of (lwp
);
1646 /* If we already have a pending stop signal for this process, don't
1648 if (lwp
->stop_expected
)
1651 fprintf (stderr
, "Have pending sigstop for lwp %d\n", pid
);
1653 /* We clear the stop_expected flag so that wait_for_sigstop
1654 will receive the SIGSTOP event (instead of silently resuming and
1655 waiting again). It'll be reset below. */
1656 lwp
->stop_expected
= 0;
1661 fprintf (stderr
, "Sending sigstop to lwp %d\n", pid
);
1663 kill_lwp (pid
, SIGSTOP
);
1667 mark_lwp_dead (struct lwp_info
*lwp
, int wstat
)
1669 /* It's dead, really. */
1672 /* Store the exit status for later. */
1673 lwp
->status_pending_p
= 1;
1674 lwp
->status_pending
= wstat
;
1676 /* So that check_removed_breakpoint doesn't try to figure out if
1677 this is stopped at a breakpoint. */
1678 lwp
->pending_is_breakpoint
= 0;
1680 /* Prevent trying to stop it. */
1683 /* No further stops are expected from a dead lwp. */
1684 lwp
->stop_expected
= 0;
1688 wait_for_sigstop (struct inferior_list_entry
*entry
)
1690 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1691 struct thread_info
*saved_inferior
;
1699 saved_inferior
= current_inferior
;
1700 if (saved_inferior
!= NULL
)
1701 saved_tid
= ((struct inferior_list_entry
*) saved_inferior
)->id
;
1703 saved_tid
= null_ptid
; /* avoid bogus unused warning */
1705 ptid
= lwp
->head
.id
;
1707 linux_wait_for_event (ptid
, &wstat
, __WALL
);
1709 /* If we stopped with a non-SIGSTOP signal, save it for later
1710 and record the pending SIGSTOP. If the process exited, just
1712 if (WIFSTOPPED (wstat
)
1713 && WSTOPSIG (wstat
) != SIGSTOP
)
1716 fprintf (stderr
, "LWP %ld stopped with non-sigstop status %06x\n",
1717 lwpid_of (lwp
), wstat
);
1719 /* Do not leave a pending single-step finish to be reported to
1720 the client. The client will give us a new action for this
1721 thread, possibly a continue request --- otherwise, the client
1722 would consider this pending SIGTRAP reported later a spurious
1724 if (WSTOPSIG (wstat
) == SIGTRAP
1726 && !linux_stopped_by_watchpoint ())
1729 fprintf (stderr
, " single-step SIGTRAP ignored\n");
1733 lwp
->status_pending_p
= 1;
1734 lwp
->status_pending
= wstat
;
1736 lwp
->stop_expected
= 1;
1738 else if (!WIFSTOPPED (wstat
))
1741 fprintf (stderr
, "Process %ld exited while stopping LWPs\n",
1744 /* Leave this status pending for the next time we're able to
1745 report it. In the mean time, we'll report this lwp as dead
1746 to GDB, so GDB doesn't try to read registers and memory from
1748 mark_lwp_dead (lwp
, wstat
);
1751 if (saved_inferior
== NULL
|| linux_thread_alive (saved_tid
))
1752 current_inferior
= saved_inferior
;
1756 fprintf (stderr
, "Previously current thread died.\n");
1760 /* We can't change the current inferior behind GDB's back,
1761 otherwise, a subsequent command may apply to the wrong
1763 current_inferior
= NULL
;
1767 /* Set a valid thread as current. */
1768 set_desired_inferior (0);
1774 stop_all_lwps (void)
1776 stopping_threads
= 1;
1777 for_each_inferior (&all_lwps
, send_sigstop
);
1778 for_each_inferior (&all_lwps
, wait_for_sigstop
);
1779 stopping_threads
= 0;
1782 /* Resume execution of the inferior process.
1783 If STEP is nonzero, single-step it.
1784 If SIGNAL is nonzero, give it that signal. */
1787 linux_resume_one_lwp (struct lwp_info
*lwp
,
1788 int step
, int signal
, siginfo_t
*info
)
1790 struct thread_info
*saved_inferior
;
1792 if (lwp
->stopped
== 0)
1795 /* If we have pending signals or status, and a new signal, enqueue the
1796 signal. Also enqueue the signal if we are waiting to reinsert a
1797 breakpoint; it will be picked up again below. */
1799 && (lwp
->status_pending_p
|| lwp
->pending_signals
!= NULL
1800 || lwp
->bp_reinsert
!= 0))
1802 struct pending_signals
*p_sig
;
1803 p_sig
= xmalloc (sizeof (*p_sig
));
1804 p_sig
->prev
= lwp
->pending_signals
;
1805 p_sig
->signal
= signal
;
1807 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
1809 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
1810 lwp
->pending_signals
= p_sig
;
1813 if (lwp
->status_pending_p
&& !check_removed_breakpoint (lwp
))
1816 saved_inferior
= current_inferior
;
1817 current_inferior
= get_lwp_thread (lwp
);
1820 fprintf (stderr
, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
1821 lwpid_of (lwp
), step
? "step" : "continue", signal
,
1822 lwp
->stop_expected
? "expected" : "not expected");
1824 /* This bit needs some thinking about. If we get a signal that
1825 we must report while a single-step reinsert is still pending,
1826 we often end up resuming the thread. It might be better to
1827 (ew) allow a stack of pending events; then we could be sure that
1828 the reinsert happened right away and not lose any signals.
1830 Making this stack would also shrink the window in which breakpoints are
1831 uninserted (see comment in linux_wait_for_lwp) but not enough for
1832 complete correctness, so it won't solve that problem. It may be
1833 worthwhile just to solve this one, however. */
1834 if (lwp
->bp_reinsert
!= 0)
1837 fprintf (stderr
, " pending reinsert at %08lx", (long)lwp
->bp_reinsert
);
1839 fprintf (stderr
, "BAD - reinserting but not stepping.\n");
1842 /* Postpone any pending signal. It was enqueued above. */
1846 check_removed_breakpoint (lwp
);
1848 if (debug_threads
&& the_low_target
.get_pc
!= NULL
)
1850 struct regcache
*regcache
= get_thread_regcache (current_inferior
, 1);
1851 CORE_ADDR pc
= (*the_low_target
.get_pc
) (regcache
);
1852 fprintf (stderr
, " resuming from pc 0x%lx\n", (long) pc
);
1855 /* If we have pending signals, consume one unless we are trying to reinsert
1857 if (lwp
->pending_signals
!= NULL
&& lwp
->bp_reinsert
== 0)
1859 struct pending_signals
**p_sig
;
1861 p_sig
= &lwp
->pending_signals
;
1862 while ((*p_sig
)->prev
!= NULL
)
1863 p_sig
= &(*p_sig
)->prev
;
1865 signal
= (*p_sig
)->signal
;
1866 if ((*p_sig
)->info
.si_signo
!= 0)
1867 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &(*p_sig
)->info
);
1873 if (the_low_target
.prepare_to_resume
!= NULL
)
1874 the_low_target
.prepare_to_resume (lwp
);
1876 regcache_invalidate_one ((struct inferior_list_entry
*)
1877 get_lwp_thread (lwp
));
1880 lwp
->stepping
= step
;
1881 ptrace (step
? PTRACE_SINGLESTEP
: PTRACE_CONT
, lwpid_of (lwp
), 0,
1882 /* Coerce to a uintptr_t first to avoid potential gcc warning
1883 of coercing an 8 byte integer to a 4 byte pointer. */
1884 (PTRACE_ARG4_TYPE
) (uintptr_t) signal
);
1886 current_inferior
= saved_inferior
;
1889 /* ESRCH from ptrace either means that the thread was already
1890 running (an error) or that it is gone (a race condition). If
1891 it's gone, we will get a notification the next time we wait,
1892 so we can ignore the error. We could differentiate these
1893 two, but it's tricky without waiting; the thread still exists
1894 as a zombie, so sending it signal 0 would succeed. So just
1899 perror_with_name ("ptrace");
1903 struct thread_resume_array
1905 struct thread_resume
*resume
;
1909 /* This function is called once per thread. We look up the thread
1910 in RESUME_PTR, and mark the thread with a pointer to the appropriate
1913 This algorithm is O(threads * resume elements), but resume elements
1914 is small (and will remain small at least until GDB supports thread
1917 linux_set_resume_request (struct inferior_list_entry
*entry
, void *arg
)
1919 struct lwp_info
*lwp
;
1920 struct thread_info
*thread
;
1922 struct thread_resume_array
*r
;
1924 thread
= (struct thread_info
*) entry
;
1925 lwp
= get_thread_lwp (thread
);
1928 for (ndx
= 0; ndx
< r
->n
; ndx
++)
1930 ptid_t ptid
= r
->resume
[ndx
].thread
;
1931 if (ptid_equal (ptid
, minus_one_ptid
)
1932 || ptid_equal (ptid
, entry
->id
)
1933 || (ptid_is_pid (ptid
)
1934 && (ptid_get_pid (ptid
) == pid_of (lwp
)))
1935 || (ptid_get_lwp (ptid
) == -1
1936 && (ptid_get_pid (ptid
) == pid_of (lwp
))))
1938 lwp
->resume
= &r
->resume
[ndx
];
1943 /* No resume action for this thread. */
1950 /* Set *FLAG_P if this lwp has an interesting status pending. */
1952 resume_status_pending_p (struct inferior_list_entry
*entry
, void *flag_p
)
1954 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1956 /* LWPs which will not be resumed are not interesting, because
1957 we might not wait for them next time through linux_wait. */
1958 if (lwp
->resume
== NULL
)
1961 /* If this thread has a removed breakpoint, we won't have any
1962 events to report later, so check now. check_removed_breakpoint
1963 may clear status_pending_p. We avoid calling check_removed_breakpoint
1964 for any thread that we are not otherwise going to resume - this
1965 lets us preserve stopped status when two threads hit a breakpoint.
1966 GDB removes the breakpoint to single-step a particular thread
1967 past it, then re-inserts it and resumes all threads. We want
1968 to report the second thread without resuming it in the interim. */
1969 if (lwp
->status_pending_p
)
1970 check_removed_breakpoint (lwp
);
1972 if (lwp
->status_pending_p
)
1973 * (int *) flag_p
= 1;
1978 /* This function is called once per thread. We check the thread's resume
1979 request, which will tell us whether to resume, step, or leave the thread
1980 stopped; and what signal, if any, it should be sent.
1982 For threads which we aren't explicitly told otherwise, we preserve
1983 the stepping flag; this is used for stepping over gdbserver-placed
1986 If pending_flags was set in any thread, we queue any needed
1987 signals, since we won't actually resume. We already have a pending
1988 event to report, so we don't need to preserve any step requests;
1989 they should be re-issued if necessary. */
1992 linux_resume_one_thread (struct inferior_list_entry
*entry
, void *arg
)
1994 struct lwp_info
*lwp
;
1995 struct thread_info
*thread
;
1997 int pending_flag
= * (int *) arg
;
1999 thread
= (struct thread_info
*) entry
;
2000 lwp
= get_thread_lwp (thread
);
2002 if (lwp
->resume
== NULL
)
2005 if (lwp
->resume
->kind
== resume_stop
)
2008 fprintf (stderr
, "suspending LWP %ld\n", lwpid_of (lwp
));
2013 fprintf (stderr
, "running -> suspending LWP %ld\n", lwpid_of (lwp
));
2016 send_sigstop (&lwp
->head
);
2023 fprintf (stderr
, "already stopped/suspended LWP %ld\n",
2026 fprintf (stderr
, "already stopped/not suspended LWP %ld\n",
2030 /* Make sure we leave the LWP suspended, so we don't try to
2031 resume it without GDB telling us to. FIXME: The LWP may
2032 have been stopped in an internal event that was not meant
2033 to be notified back to GDB (e.g., gdbserver breakpoint),
2034 so we should be reporting a stop event in that case
2039 /* For stop requests, we're done. */
2046 /* If this thread which is about to be resumed has a pending status,
2047 then don't resume any threads - we can just report the pending
2048 status. Make sure to queue any signals that would otherwise be
2049 sent. In all-stop mode, we do this decision based on if *any*
2050 thread has a pending status. */
2052 resume_status_pending_p (&lwp
->head
, &pending_flag
);
2057 fprintf (stderr
, "resuming LWP %ld\n", lwpid_of (lwp
));
2059 if (ptid_equal (lwp
->resume
->thread
, minus_one_ptid
)
2061 && lwp
->pending_is_breakpoint
)
2064 step
= (lwp
->resume
->kind
== resume_step
);
2066 linux_resume_one_lwp (lwp
, step
, lwp
->resume
->sig
, NULL
);
2071 fprintf (stderr
, "leaving LWP %ld stopped\n", lwpid_of (lwp
));
2073 /* If we have a new signal, enqueue the signal. */
2074 if (lwp
->resume
->sig
!= 0)
2076 struct pending_signals
*p_sig
;
2077 p_sig
= xmalloc (sizeof (*p_sig
));
2078 p_sig
->prev
= lwp
->pending_signals
;
2079 p_sig
->signal
= lwp
->resume
->sig
;
2080 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
2082 /* If this is the same signal we were previously stopped by,
2083 make sure to queue its siginfo. We can ignore the return
2084 value of ptrace; if it fails, we'll skip
2085 PTRACE_SETSIGINFO. */
2086 if (WIFSTOPPED (lwp
->last_status
)
2087 && WSTOPSIG (lwp
->last_status
) == lwp
->resume
->sig
)
2088 ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &p_sig
->info
);
2090 lwp
->pending_signals
= p_sig
;
2099 linux_resume (struct thread_resume
*resume_info
, size_t n
)
2102 struct thread_resume_array array
= { resume_info
, n
};
2104 find_inferior (&all_threads
, linux_set_resume_request
, &array
);
2106 /* If there is a thread which would otherwise be resumed, which
2107 has a pending status, then don't resume any threads - we can just
2108 report the pending status. Make sure to queue any signals
2109 that would otherwise be sent. In non-stop mode, we'll apply this
2110 logic to each thread individually. */
2113 find_inferior (&all_lwps
, resume_status_pending_p
, &pending_flag
);
2118 fprintf (stderr
, "Not resuming, pending status\n");
2120 fprintf (stderr
, "Resuming, no pending status\n");
2123 find_inferior (&all_threads
, linux_resume_one_thread
, &pending_flag
);
2126 #ifdef HAVE_LINUX_USRREGS
2129 register_addr (int regnum
)
2133 if (regnum
< 0 || regnum
>= the_low_target
.num_regs
)
2134 error ("Invalid register number %d.", regnum
);
2136 addr
= the_low_target
.regmap
[regnum
];
2141 /* Fetch one register. */
2143 fetch_register (struct regcache
*regcache
, int regno
)
2150 if (regno
>= the_low_target
.num_regs
)
2152 if ((*the_low_target
.cannot_fetch_register
) (regno
))
2155 regaddr
= register_addr (regno
);
2159 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2160 size
= ((register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
2161 & - sizeof (PTRACE_XFER_TYPE
));
2162 buf
= alloca (size
);
2163 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
2166 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
2167 ptrace (PTRACE_PEEKUSER
, pid
,
2168 /* Coerce to a uintptr_t first to avoid potential gcc warning
2169 of coercing an 8 byte integer to a 4 byte pointer. */
2170 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
, 0);
2171 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
2174 /* Warning, not error, in case we are attached; sometimes the
2175 kernel doesn't let us at the registers. */
2176 char *err
= strerror (errno
);
2177 char *msg
= alloca (strlen (err
) + 128);
2178 sprintf (msg
, "reading register %d: %s", regno
, err
);
2184 if (the_low_target
.supply_ptrace_register
)
2185 the_low_target
.supply_ptrace_register (regcache
, regno
, buf
);
2187 supply_register (regcache
, regno
, buf
);
2192 /* Fetch all registers, or just one, from the child process. */
2194 usr_fetch_inferior_registers (struct regcache
*regcache
, int regno
)
2197 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
2198 fetch_register (regcache
, regno
);
2200 fetch_register (regcache
, regno
);
2203 /* Store our register values back into the inferior.
2204 If REGNO is -1, do this for all registers.
2205 Otherwise, REGNO specifies which register (so we can save time). */
2207 usr_store_inferior_registers (struct regcache
*regcache
, int regno
)
2216 if (regno
>= the_low_target
.num_regs
)
2219 if ((*the_low_target
.cannot_store_register
) (regno
) == 1)
2222 regaddr
= register_addr (regno
);
2226 size
= (register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
2227 & - sizeof (PTRACE_XFER_TYPE
);
2228 buf
= alloca (size
);
2229 memset (buf
, 0, size
);
2231 if (the_low_target
.collect_ptrace_register
)
2232 the_low_target
.collect_ptrace_register (regcache
, regno
, buf
);
2234 collect_register (regcache
, regno
, buf
);
2236 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2237 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
2240 ptrace (PTRACE_POKEUSER
, pid
,
2241 /* Coerce to a uintptr_t first to avoid potential gcc warning
2242 about coercing an 8 byte integer to a 4 byte pointer. */
2243 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
,
2244 (PTRACE_ARG4_TYPE
) *(PTRACE_XFER_TYPE
*) (buf
+ i
));
2247 /* At this point, ESRCH should mean the process is
2248 already gone, in which case we simply ignore attempts
2249 to change its registers. See also the related
2250 comment in linux_resume_one_lwp. */
2254 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
2256 char *err
= strerror (errno
);
2257 char *msg
= alloca (strlen (err
) + 128);
2258 sprintf (msg
, "writing register %d: %s",
2264 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
2268 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
2269 usr_store_inferior_registers (regcache
, regno
);
2271 #endif /* HAVE_LINUX_USRREGS */
2275 #ifdef HAVE_LINUX_REGSETS
2278 regsets_fetch_inferior_registers (struct regcache
*regcache
)
2280 struct regset_info
*regset
;
2281 int saw_general_regs
= 0;
2284 regset
= target_regsets
;
2286 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2287 while (regset
->size
>= 0)
2292 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
2298 buf
= xmalloc (regset
->size
);
2300 res
= ptrace (regset
->get_request
, pid
, 0, buf
);
2302 res
= ptrace (regset
->get_request
, pid
, buf
, 0);
2308 /* If we get EIO on a regset, do not try it again for
2310 disabled_regsets
[regset
- target_regsets
] = 1;
2317 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%d",
2322 else if (regset
->type
== GENERAL_REGS
)
2323 saw_general_regs
= 1;
2324 regset
->store_function (regcache
, buf
);
2328 if (saw_general_regs
)
2335 regsets_store_inferior_registers (struct regcache
*regcache
)
2337 struct regset_info
*regset
;
2338 int saw_general_regs
= 0;
2341 regset
= target_regsets
;
2343 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2344 while (regset
->size
>= 0)
2349 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
2355 buf
= xmalloc (regset
->size
);
2357 /* First fill the buffer with the current register set contents,
2358 in case there are any items in the kernel's regset that are
2359 not in gdbserver's regcache. */
2361 res
= ptrace (regset
->get_request
, pid
, 0, buf
);
2363 res
= ptrace (regset
->get_request
, pid
, buf
, 0);
2368 /* Then overlay our cached registers on that. */
2369 regset
->fill_function (regcache
, buf
);
2371 /* Only now do we write the register set. */
2373 res
= ptrace (regset
->set_request
, pid
, 0, buf
);
2375 res
= ptrace (regset
->set_request
, pid
, buf
, 0);
2383 /* If we get EIO on a regset, do not try it again for
2385 disabled_regsets
[regset
- target_regsets
] = 1;
2389 else if (errno
== ESRCH
)
2391 /* At this point, ESRCH should mean the process is
2392 already gone, in which case we simply ignore attempts
2393 to change its registers. See also the related
2394 comment in linux_resume_one_lwp. */
2400 perror ("Warning: ptrace(regsets_store_inferior_registers)");
2403 else if (regset
->type
== GENERAL_REGS
)
2404 saw_general_regs
= 1;
2408 if (saw_general_regs
)
2415 #endif /* HAVE_LINUX_REGSETS */
2419 linux_fetch_registers (struct regcache
*regcache
, int regno
)
2421 #ifdef HAVE_LINUX_REGSETS
2422 if (regsets_fetch_inferior_registers (regcache
) == 0)
2425 #ifdef HAVE_LINUX_USRREGS
2426 usr_fetch_inferior_registers (regcache
, regno
);
2431 linux_store_registers (struct regcache
*regcache
, int regno
)
2433 #ifdef HAVE_LINUX_REGSETS
2434 if (regsets_store_inferior_registers (regcache
) == 0)
2437 #ifdef HAVE_LINUX_USRREGS
2438 usr_store_inferior_registers (regcache
, regno
);
2443 /* Copy LEN bytes from inferior's memory starting at MEMADDR
2444 to debugger memory starting at MYADDR. */
2447 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
2450 /* Round starting address down to longword boundary. */
2451 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
2452 /* Round ending address up; get number of longwords that makes. */
2454 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
2455 / sizeof (PTRACE_XFER_TYPE
);
2456 /* Allocate buffer of that many longwords. */
2457 register PTRACE_XFER_TYPE
*buffer
2458 = (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
2461 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
2463 /* Try using /proc. Don't bother for one word. */
2464 if (len
>= 3 * sizeof (long))
2466 /* We could keep this file open and cache it - possibly one per
2467 thread. That requires some juggling, but is even faster. */
2468 sprintf (filename
, "/proc/%d/mem", pid
);
2469 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
2473 /* If pread64 is available, use it. It's faster if the kernel
2474 supports it (only one syscall), and it's 64-bit safe even on
2475 32-bit platforms (for instance, SPARC debugging a SPARC64
2478 if (pread64 (fd
, myaddr
, len
, memaddr
) != len
)
2480 if (lseek (fd
, memaddr
, SEEK_SET
) == -1 || read (fd
, myaddr
, len
) != len
)
2492 /* Read all the longwords */
2493 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
2496 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
2497 about coercing an 8 byte integer to a 4 byte pointer. */
2498 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, pid
,
2499 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
2504 /* Copy appropriate bytes out of the buffer. */
2506 (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
2512 /* Copy LEN bytes of data from debugger memory at MYADDR
2513 to inferior's memory at MEMADDR.
2514 On failure (cannot write the inferior)
2515 returns the value of errno. */
2518 linux_write_memory (CORE_ADDR memaddr
, const unsigned char *myaddr
, int len
)
2521 /* Round starting address down to longword boundary. */
2522 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
2523 /* Round ending address up; get number of longwords that makes. */
2525 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1) / sizeof (PTRACE_XFER_TYPE
);
2526 /* Allocate buffer of that many longwords. */
2527 register PTRACE_XFER_TYPE
*buffer
= (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
2528 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
2532 /* Dump up to four bytes. */
2533 unsigned int val
= * (unsigned int *) myaddr
;
2539 val
= val
& 0xffffff;
2540 fprintf (stderr
, "Writing %0*x to 0x%08lx\n", 2 * ((len
< 4) ? len
: 4),
2541 val
, (long)memaddr
);
2544 /* Fill start and end extra bytes of buffer with existing memory data. */
2546 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
2547 about coercing an 8 byte integer to a 4 byte pointer. */
2548 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, pid
,
2549 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
2554 = ptrace (PTRACE_PEEKTEXT
, pid
,
2555 /* Coerce to a uintptr_t first to avoid potential gcc warning
2556 about coercing an 8 byte integer to a 4 byte pointer. */
2557 (PTRACE_ARG3_TYPE
) (uintptr_t) (addr
+ (count
- 1)
2558 * sizeof (PTRACE_XFER_TYPE
)),
2562 /* Copy data to be written over corresponding part of buffer */
2564 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)), myaddr
, len
);
2566 /* Write the entire buffer. */
2568 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
2571 ptrace (PTRACE_POKETEXT
, pid
,
2572 /* Coerce to a uintptr_t first to avoid potential gcc warning
2573 about coercing an 8 byte integer to a 4 byte pointer. */
2574 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
,
2575 (PTRACE_ARG4_TYPE
) buffer
[i
]);
2583 static int linux_supports_tracefork_flag
;
2585 /* Helper functions for linux_test_for_tracefork, called via clone (). */
2588 linux_tracefork_grandchild (void *arg
)
2593 #define STACK_SIZE 4096
2596 linux_tracefork_child (void *arg
)
2598 ptrace (PTRACE_TRACEME
, 0, 0, 0);
2599 kill (getpid (), SIGSTOP
);
2601 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
2604 linux_tracefork_grandchild (NULL
);
2606 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
2609 __clone2 (linux_tracefork_grandchild
, arg
, STACK_SIZE
,
2610 CLONE_VM
| SIGCHLD
, NULL
);
2612 clone (linux_tracefork_grandchild
, arg
+ STACK_SIZE
,
2613 CLONE_VM
| SIGCHLD
, NULL
);
2616 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
2621 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
2622 sure that we can enable the option, and that it had the desired
2626 linux_test_for_tracefork (void)
2628 int child_pid
, ret
, status
;
2630 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
2631 char *stack
= xmalloc (STACK_SIZE
* 4);
2632 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
2634 linux_supports_tracefork_flag
= 0;
2636 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
2638 child_pid
= fork ();
2640 linux_tracefork_child (NULL
);
2642 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
2644 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
2646 child_pid
= __clone2 (linux_tracefork_child
, stack
, STACK_SIZE
,
2647 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
2648 #else /* !__ia64__ */
2649 child_pid
= clone (linux_tracefork_child
, stack
+ STACK_SIZE
,
2650 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
2651 #endif /* !__ia64__ */
2653 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
2655 if (child_pid
== -1)
2656 perror_with_name ("clone");
2658 ret
= my_waitpid (child_pid
, &status
, 0);
2660 perror_with_name ("waitpid");
2661 else if (ret
!= child_pid
)
2662 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret
);
2663 if (! WIFSTOPPED (status
))
2664 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status
);
2666 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0,
2667 (PTRACE_ARG4_TYPE
) PTRACE_O_TRACEFORK
);
2670 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
2673 warning ("linux_test_for_tracefork: failed to kill child");
2677 ret
= my_waitpid (child_pid
, &status
, 0);
2678 if (ret
!= child_pid
)
2679 warning ("linux_test_for_tracefork: failed to wait for killed child");
2680 else if (!WIFSIGNALED (status
))
2681 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
2682 "killed child", status
);
2687 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
2689 warning ("linux_test_for_tracefork: failed to resume child");
2691 ret
= my_waitpid (child_pid
, &status
, 0);
2693 if (ret
== child_pid
&& WIFSTOPPED (status
)
2694 && status
>> 16 == PTRACE_EVENT_FORK
)
2697 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
2698 if (ret
== 0 && second_pid
!= 0)
2702 linux_supports_tracefork_flag
= 1;
2703 my_waitpid (second_pid
, &second_status
, 0);
2704 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
2706 warning ("linux_test_for_tracefork: failed to kill second child");
2707 my_waitpid (second_pid
, &status
, 0);
2711 warning ("linux_test_for_tracefork: unexpected result from waitpid "
2712 "(%d, status 0x%x)", ret
, status
);
2716 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
2718 warning ("linux_test_for_tracefork: failed to kill child");
2719 my_waitpid (child_pid
, &status
, 0);
2721 while (WIFSTOPPED (status
));
2723 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
2725 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
2730 linux_look_up_symbols (void)
2732 #ifdef USE_THREAD_DB
2733 struct process_info
*proc
= current_process ();
2735 if (proc
->private->thread_db
!= NULL
)
2738 thread_db_init (!linux_supports_tracefork_flag
);
2743 linux_request_interrupt (void)
2745 extern unsigned long signal_pid
;
2747 if (!ptid_equal (cont_thread
, null_ptid
)
2748 && !ptid_equal (cont_thread
, minus_one_ptid
))
2750 struct lwp_info
*lwp
;
2753 lwp
= get_thread_lwp (current_inferior
);
2754 lwpid
= lwpid_of (lwp
);
2755 kill_lwp (lwpid
, SIGINT
);
2758 kill_lwp (signal_pid
, SIGINT
);
2761 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
2762 to debugger memory starting at MYADDR. */
2765 linux_read_auxv (CORE_ADDR offset
, unsigned char *myaddr
, unsigned int len
)
2767 char filename
[PATH_MAX
];
2769 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
2771 snprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
2773 fd
= open (filename
, O_RDONLY
);
2777 if (offset
!= (CORE_ADDR
) 0
2778 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
2781 n
= read (fd
, myaddr
, len
);
2788 /* These breakpoint and watchpoint related wrapper functions simply
2789 pass on the function call if the target has registered a
2790 corresponding function. */
2793 linux_insert_point (char type
, CORE_ADDR addr
, int len
)
2795 if (the_low_target
.insert_point
!= NULL
)
2796 return the_low_target
.insert_point (type
, addr
, len
);
2798 /* Unsupported (see target.h). */
2803 linux_remove_point (char type
, CORE_ADDR addr
, int len
)
2805 if (the_low_target
.remove_point
!= NULL
)
2806 return the_low_target
.remove_point (type
, addr
, len
);
2808 /* Unsupported (see target.h). */
2813 linux_stopped_by_watchpoint (void)
2815 if (the_low_target
.stopped_by_watchpoint
!= NULL
)
2816 return the_low_target
.stopped_by_watchpoint ();
2822 linux_stopped_data_address (void)
2824 if (the_low_target
.stopped_data_address
!= NULL
)
2825 return the_low_target
.stopped_data_address ();
2830 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
2831 #if defined(__mcoldfire__)
2832 /* These should really be defined in the kernel's ptrace.h header. */
2833 #define PT_TEXT_ADDR 49*4
2834 #define PT_DATA_ADDR 50*4
2835 #define PT_TEXT_END_ADDR 51*4
2838 /* Under uClinux, programs are loaded at non-zero offsets, which we need
2839 to tell gdb about. */
2842 linux_read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
2844 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
2845 unsigned long text
, text_end
, data
;
2846 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
2850 text
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_ADDR
, 0);
2851 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_END_ADDR
, 0);
2852 data
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_DATA_ADDR
, 0);
2856 /* Both text and data offsets produced at compile-time (and so
2857 used by gdb) are relative to the beginning of the program,
2858 with the data segment immediately following the text segment.
2859 However, the actual runtime layout in memory may put the data
2860 somewhere else, so when we send gdb a data base-address, we
2861 use the real data base address and subtract the compile-time
2862 data base-address from it (which is just the length of the
2863 text segment). BSS immediately follows data in both
2866 *data_p
= data
- (text_end
- text
);
2876 compare_ints (const void *xa
, const void *xb
)
2878 int a
= *(const int *)xa
;
2879 int b
= *(const int *)xb
;
2885 unique (int *b
, int *e
)
2894 /* Given PID, iterates over all threads in that process.
2896 Information about each thread, in a format suitable for qXfer:osdata:thread
2897 is printed to BUFFER, if it's not NULL. BUFFER is assumed to be already
2898 initialized, and the caller is responsible for finishing and appending '\0'
2901 The list of cores that threads are running on is assigned to *CORES, if it
2902 is not NULL. If no cores are found, *CORES will be set to NULL. Caller
2903 should free *CORES. */
2906 list_threads (int pid
, struct buffer
*buffer
, char **cores
)
2910 int *core_numbers
= xmalloc (sizeof (int) * allocated
);
2914 struct stat statbuf
;
2916 sprintf (pathname
, "/proc/%d/task", pid
);
2917 if (stat (pathname
, &statbuf
) == 0 && S_ISDIR (statbuf
.st_mode
))
2919 dir
= opendir (pathname
);
2922 free (core_numbers
);
2926 while ((dp
= readdir (dir
)) != NULL
)
2928 unsigned long lwp
= strtoul (dp
->d_name
, NULL
, 10);
2932 unsigned core
= linux_core_of_thread (ptid_build (pid
, lwp
, 0));
2936 char s
[sizeof ("4294967295")];
2937 sprintf (s
, "%u", core
);
2939 if (count
== allocated
)
2942 core_numbers
= realloc (core_numbers
,
2943 sizeof (int) * allocated
);
2945 core_numbers
[count
++] = core
;
2947 buffer_xml_printf (buffer
,
2949 "<column name=\"pid\">%d</column>"
2950 "<column name=\"tid\">%s</column>"
2951 "<column name=\"core\">%s</column>"
2952 "</item>", pid
, dp
->d_name
, s
);
2957 buffer_xml_printf (buffer
,
2959 "<column name=\"pid\">%d</column>"
2960 "<column name=\"tid\">%s</column>"
2961 "</item>", pid
, dp
->d_name
);
2972 struct buffer buffer2
;
2975 qsort (core_numbers
, count
, sizeof (int), compare_ints
);
2977 /* Remove duplicates. */
2979 e
= unique (b
, core_numbers
+ count
);
2981 buffer_init (&buffer2
);
2983 for (b
= core_numbers
; b
!= e
; ++b
)
2985 char number
[sizeof ("4294967295")];
2986 sprintf (number
, "%u", *b
);
2987 buffer_xml_printf (&buffer2
, "%s%s",
2988 (b
== core_numbers
) ? "" : ",", number
);
2990 buffer_grow_str0 (&buffer2
, "");
2992 *cores
= buffer_finish (&buffer2
);
2995 free (core_numbers
);
2999 show_process (int pid
, const char *username
, struct buffer
*buffer
)
3003 char cmd
[MAXPATHLEN
+ 1];
3005 sprintf (pathname
, "/proc/%d/cmdline", pid
);
3007 if ((f
= fopen (pathname
, "r")) != NULL
)
3009 size_t len
= fread (cmd
, 1, sizeof (cmd
) - 1, f
);
3014 for (i
= 0; i
< len
; i
++)
3019 buffer_xml_printf (buffer
,
3021 "<column name=\"pid\">%d</column>"
3022 "<column name=\"user\">%s</column>"
3023 "<column name=\"command\">%s</column>",
3028 /* This only collects core numbers, and does not print threads. */
3029 list_threads (pid
, NULL
, &cores
);
3033 buffer_xml_printf (buffer
,
3034 "<column name=\"cores\">%s</column>", cores
);
3038 buffer_xml_printf (buffer
, "</item>");
3045 linux_qxfer_osdata (const char *annex
,
3046 unsigned char *readbuf
, unsigned const char *writebuf
,
3047 CORE_ADDR offset
, int len
)
3049 /* We make the process list snapshot when the object starts to be
3051 static const char *buf
;
3052 static long len_avail
= -1;
3053 static struct buffer buffer
;
3059 if (strcmp (annex
, "processes") == 0)
3061 else if (strcmp (annex
, "threads") == 0)
3066 if (!readbuf
|| writebuf
)
3071 if (len_avail
!= -1 && len_avail
!= 0)
3072 buffer_free (&buffer
);
3075 buffer_init (&buffer
);
3077 buffer_grow_str (&buffer
, "<osdata type=\"processes\">");
3079 buffer_grow_str (&buffer
, "<osdata type=\"threads\">");
3081 dirp
= opendir ("/proc");
3085 while ((dp
= readdir (dirp
)) != NULL
)
3087 struct stat statbuf
;
3088 char procentry
[sizeof ("/proc/4294967295")];
3090 if (!isdigit (dp
->d_name
[0])
3091 || strlen (dp
->d_name
) > sizeof ("4294967295") - 1)
3094 sprintf (procentry
, "/proc/%s", dp
->d_name
);
3095 if (stat (procentry
, &statbuf
) == 0
3096 && S_ISDIR (statbuf
.st_mode
))
3098 int pid
= (int) strtoul (dp
->d_name
, NULL
, 10);
3102 struct passwd
*entry
= getpwuid (statbuf
.st_uid
);
3103 show_process (pid
, entry
? entry
->pw_name
: "?", &buffer
);
3107 list_threads (pid
, &buffer
, NULL
);
3114 buffer_grow_str0 (&buffer
, "</osdata>\n");
3115 buf
= buffer_finish (&buffer
);
3116 len_avail
= strlen (buf
);
3119 if (offset
>= len_avail
)
3121 /* Done. Get rid of the data. */
3122 buffer_free (&buffer
);
3128 if (len
> len_avail
- offset
)
3129 len
= len_avail
- offset
;
3130 memcpy (readbuf
, buf
+ offset
, len
);
3135 /* Convert a native/host siginfo object, into/from the siginfo in the
3136 layout of the inferiors' architecture. */
3139 siginfo_fixup (struct siginfo
*siginfo
, void *inf_siginfo
, int direction
)
3143 if (the_low_target
.siginfo_fixup
!= NULL
)
3144 done
= the_low_target
.siginfo_fixup (siginfo
, inf_siginfo
, direction
);
3146 /* If there was no callback, or the callback didn't do anything,
3147 then just do a straight memcpy. */
3151 memcpy (siginfo
, inf_siginfo
, sizeof (struct siginfo
));
3153 memcpy (inf_siginfo
, siginfo
, sizeof (struct siginfo
));
3158 linux_xfer_siginfo (const char *annex
, unsigned char *readbuf
,
3159 unsigned const char *writebuf
, CORE_ADDR offset
, int len
)
3162 struct siginfo siginfo
;
3163 char inf_siginfo
[sizeof (struct siginfo
)];
3165 if (current_inferior
== NULL
)
3168 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3171 fprintf (stderr
, "%s siginfo for lwp %d.\n",
3172 readbuf
!= NULL
? "Reading" : "Writing",
3175 if (offset
> sizeof (siginfo
))
3178 if (ptrace (PTRACE_GETSIGINFO
, pid
, 0, &siginfo
) != 0)
3181 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
3182 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3183 inferior with a 64-bit GDBSERVER should look the same as debugging it
3184 with a 32-bit GDBSERVER, we need to convert it. */
3185 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
3187 if (offset
+ len
> sizeof (siginfo
))
3188 len
= sizeof (siginfo
) - offset
;
3190 if (readbuf
!= NULL
)
3191 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
3194 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
3196 /* Convert back to ptrace layout before flushing it out. */
3197 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
3199 if (ptrace (PTRACE_SETSIGINFO
, pid
, 0, &siginfo
) != 0)
3206 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
3207 so we notice when children change state; as the handler for the
3208 sigsuspend in my_waitpid. */
3211 sigchld_handler (int signo
)
3213 int old_errno
= errno
;
3216 /* fprintf is not async-signal-safe, so call write directly. */
3217 write (2, "sigchld_handler\n", sizeof ("sigchld_handler\n") - 1);
3219 if (target_is_async_p ())
3220 async_file_mark (); /* trigger a linux_wait */
3226 linux_supports_non_stop (void)
3232 linux_async (int enable
)
3234 int previous
= (linux_event_pipe
[0] != -1);
3236 if (previous
!= enable
)
3239 sigemptyset (&mask
);
3240 sigaddset (&mask
, SIGCHLD
);
3242 sigprocmask (SIG_BLOCK
, &mask
, NULL
);
3246 if (pipe (linux_event_pipe
) == -1)
3247 fatal ("creating event pipe failed.");
3249 fcntl (linux_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
3250 fcntl (linux_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
3252 /* Register the event loop handler. */
3253 add_file_handler (linux_event_pipe
[0],
3254 handle_target_event
, NULL
);
3256 /* Always trigger a linux_wait. */
3261 delete_file_handler (linux_event_pipe
[0]);
3263 close (linux_event_pipe
[0]);
3264 close (linux_event_pipe
[1]);
3265 linux_event_pipe
[0] = -1;
3266 linux_event_pipe
[1] = -1;
3269 sigprocmask (SIG_UNBLOCK
, &mask
, NULL
);
3276 linux_start_non_stop (int nonstop
)
3278 /* Register or unregister from event-loop accordingly. */
3279 linux_async (nonstop
);
3284 linux_supports_multi_process (void)
3290 /* Enumerate spufs IDs for process PID. */
3292 spu_enumerate_spu_ids (long pid
, unsigned char *buf
, CORE_ADDR offset
, int len
)
3298 struct dirent
*entry
;
3300 sprintf (path
, "/proc/%ld/fd", pid
);
3301 dir
= opendir (path
);
3306 while ((entry
= readdir (dir
)) != NULL
)
3312 fd
= atoi (entry
->d_name
);
3316 sprintf (path
, "/proc/%ld/fd/%d", pid
, fd
);
3317 if (stat (path
, &st
) != 0)
3319 if (!S_ISDIR (st
.st_mode
))
3322 if (statfs (path
, &stfs
) != 0)
3324 if (stfs
.f_type
!= SPUFS_MAGIC
)
3327 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
3329 *(unsigned int *)(buf
+ pos
- offset
) = fd
;
3339 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
3340 object type, using the /proc file system. */
3342 linux_qxfer_spu (const char *annex
, unsigned char *readbuf
,
3343 unsigned const char *writebuf
,
3344 CORE_ADDR offset
, int len
)
3346 long pid
= lwpid_of (get_thread_lwp (current_inferior
));
3351 if (!writebuf
&& !readbuf
)
3359 return spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
3362 sprintf (buf
, "/proc/%ld/fd/%s", pid
, annex
);
3363 fd
= open (buf
, writebuf
? O_WRONLY
: O_RDONLY
);
3368 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
3375 ret
= write (fd
, writebuf
, (size_t) len
);
3377 ret
= read (fd
, readbuf
, (size_t) len
);
3384 linux_core_of_thread (ptid_t ptid
)
3386 char filename
[sizeof ("/proc//task//stat")
3387 + 2 * 20 /* decimal digits for 2 numbers, max 2^64 bit each */
3390 char *content
= NULL
;
3393 int content_read
= 0;
3397 sprintf (filename
, "/proc/%d/task/%ld/stat",
3398 ptid_get_pid (ptid
), ptid_get_lwp (ptid
));
3399 f
= fopen (filename
, "r");
3406 content
= realloc (content
, content_read
+ 1024);
3407 n
= fread (content
+ content_read
, 1, 1024, f
);
3411 content
[content_read
] = '\0';
3416 p
= strchr (content
, '(');
3417 p
= strchr (p
, ')') + 2; /* skip ")" and a whitespace. */
3419 p
= strtok_r (p
, " ", &ts
);
3420 for (i
= 0; i
!= 36; ++i
)
3421 p
= strtok_r (NULL
, " ", &ts
);
3423 if (sscanf (p
, "%d", &core
) == 0)
3432 static struct target_ops linux_target_ops
= {
3433 linux_create_inferior
,
3441 linux_fetch_registers
,
3442 linux_store_registers
,
3445 linux_look_up_symbols
,
3446 linux_request_interrupt
,
3450 linux_stopped_by_watchpoint
,
3451 linux_stopped_data_address
,
3452 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
3457 #ifdef USE_THREAD_DB
3458 thread_db_get_tls_address
,
3463 hostio_last_error_from_errno
,
3466 linux_supports_non_stop
,
3468 linux_start_non_stop
,
3469 linux_supports_multi_process
,
3470 #ifdef USE_THREAD_DB
3471 thread_db_handle_monitor_command
,
3475 linux_core_of_thread
3479 linux_init_signals ()
3481 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
3482 to find what the cancel signal actually is. */
3483 #ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
3484 signal (__SIGRTMIN
+1, SIG_IGN
);
3489 initialize_low (void)
3491 struct sigaction sigchld_action
;
3492 memset (&sigchld_action
, 0, sizeof (sigchld_action
));
3493 set_target_ops (&linux_target_ops
);
3494 set_breakpoint_data (the_low_target
.breakpoint
,
3495 the_low_target
.breakpoint_len
);
3496 linux_init_signals ();
3497 linux_test_for_tracefork ();
3498 #ifdef HAVE_LINUX_REGSETS
3499 for (num_regsets
= 0; target_regsets
[num_regsets
].size
>= 0; num_regsets
++)
3501 disabled_regsets
= xmalloc (num_regsets
);
3504 sigchld_action
.sa_handler
= sigchld_handler
;
3505 sigemptyset (&sigchld_action
.sa_mask
);
3506 sigchld_action
.sa_flags
= SA_RESTART
;
3507 sigaction (SIGCHLD
, &sigchld_action
, NULL
);