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 void *add_lwp (ptid_t ptid
);
144 static int linux_stopped_by_watchpoint (void);
145 static void mark_lwp_dead (struct lwp_info
*lwp
, int wstat
);
146 static int linux_core_of_thread (ptid_t ptid
);
147 static void proceed_all_lwps (void);
148 static void unstop_all_lwps (struct lwp_info
*except
);
149 static int finish_step_over (struct lwp_info
*lwp
);
150 static CORE_ADDR
get_stop_pc (struct lwp_info
*lwp
);
151 static int kill_lwp (unsigned long lwpid
, int signo
);
153 /* True if the low target can hardware single-step. Such targets
154 don't need a BREAKPOINT_REINSERT_ADDR callback. */
157 can_hardware_single_step (void)
159 return (the_low_target
.breakpoint_reinsert_addr
== NULL
);
162 /* True if the low target supports memory breakpoints. If so, we'll
163 have a GET_PC implementation. */
166 supports_breakpoints (void)
168 return (the_low_target
.get_pc
!= NULL
);
171 struct pending_signals
175 struct pending_signals
*prev
;
178 #define PTRACE_ARG3_TYPE void *
179 #define PTRACE_ARG4_TYPE void *
180 #define PTRACE_XFER_TYPE long
182 #ifdef HAVE_LINUX_REGSETS
183 static char *disabled_regsets
;
184 static int num_regsets
;
187 /* The read/write ends of the pipe registered as waitable file in the
189 static int linux_event_pipe
[2] = { -1, -1 };
191 /* True if we're currently in async mode. */
192 #define target_is_async_p() (linux_event_pipe[0] != -1)
194 static void send_sigstop (struct inferior_list_entry
*entry
);
195 static void wait_for_sigstop (struct inferior_list_entry
*entry
);
197 /* Accepts an integer PID; Returns a string representing a file that
198 can be opened to get info for the child process.
199 Space for the result is malloc'd, caller must free. */
202 linux_child_pid_to_exec_file (int pid
)
206 name1
= xmalloc (MAXPATHLEN
);
207 name2
= xmalloc (MAXPATHLEN
);
208 memset (name2
, 0, MAXPATHLEN
);
210 sprintf (name1
, "/proc/%d/exe", pid
);
211 if (readlink (name1
, name2
, MAXPATHLEN
) > 0)
223 /* Return non-zero if HEADER is a 64-bit ELF file. */
226 elf_64_header_p (const Elf64_Ehdr
*header
)
228 return (header
->e_ident
[EI_MAG0
] == ELFMAG0
229 && header
->e_ident
[EI_MAG1
] == ELFMAG1
230 && header
->e_ident
[EI_MAG2
] == ELFMAG2
231 && header
->e_ident
[EI_MAG3
] == ELFMAG3
232 && header
->e_ident
[EI_CLASS
] == ELFCLASS64
);
235 /* Return non-zero if FILE is a 64-bit ELF file,
236 zero if the file is not a 64-bit ELF file,
237 and -1 if the file is not accessible or doesn't exist. */
240 elf_64_file_p (const char *file
)
245 fd
= open (file
, O_RDONLY
);
249 if (read (fd
, &header
, sizeof (header
)) != sizeof (header
))
256 return elf_64_header_p (&header
);
260 delete_lwp (struct lwp_info
*lwp
)
262 remove_thread (get_lwp_thread (lwp
));
263 remove_inferior (&all_lwps
, &lwp
->head
);
264 free (lwp
->arch_private
);
268 /* Add a process to the common process list, and set its private
271 static struct process_info
*
272 linux_add_process (int pid
, int attached
)
274 struct process_info
*proc
;
276 /* Is this the first process? If so, then set the arch. */
277 if (all_processes
.head
== NULL
)
280 proc
= add_process (pid
, attached
);
281 proc
->private = xcalloc (1, sizeof (*proc
->private));
283 if (the_low_target
.new_process
!= NULL
)
284 proc
->private->arch_private
= the_low_target
.new_process ();
289 /* Remove a process from the common process list,
290 also freeing all private data. */
293 linux_remove_process (struct process_info
*process
)
295 struct process_info_private
*priv
= process
->private;
297 free (priv
->arch_private
);
299 remove_process (process
);
302 /* Wrapper function for waitpid which handles EINTR, and emulates
303 __WALL for systems where that is not available. */
306 my_waitpid (int pid
, int *status
, int flags
)
311 fprintf (stderr
, "my_waitpid (%d, 0x%x)\n", pid
, flags
);
315 sigset_t block_mask
, org_mask
, wake_mask
;
318 wnohang
= (flags
& WNOHANG
) != 0;
319 flags
&= ~(__WALL
| __WCLONE
);
322 /* Block all signals while here. This avoids knowing about
323 LinuxThread's signals. */
324 sigfillset (&block_mask
);
325 sigprocmask (SIG_BLOCK
, &block_mask
, &org_mask
);
327 /* ... except during the sigsuspend below. */
328 sigemptyset (&wake_mask
);
332 /* Since all signals are blocked, there's no need to check
334 ret
= waitpid (pid
, status
, flags
);
337 if (ret
== -1 && out_errno
!= ECHILD
)
342 if (flags
& __WCLONE
)
344 /* We've tried both flavors now. If WNOHANG is set,
345 there's nothing else to do, just bail out. */
350 fprintf (stderr
, "blocking\n");
352 /* Block waiting for signals. */
353 sigsuspend (&wake_mask
);
359 sigprocmask (SIG_SETMASK
, &org_mask
, NULL
);
364 ret
= waitpid (pid
, status
, flags
);
365 while (ret
== -1 && errno
== EINTR
);
370 fprintf (stderr
, "my_waitpid (%d, 0x%x): status(%x), %d\n",
371 pid
, flags
, status
? *status
: -1, ret
);
377 /* Handle a GNU/Linux extended wait response. If we see a clone
378 event, we need to add the new LWP to our list (and not report the
379 trap to higher layers). */
382 handle_extended_wait (struct lwp_info
*event_child
, int wstat
)
384 int event
= wstat
>> 16;
385 struct lwp_info
*new_lwp
;
387 if (event
== PTRACE_EVENT_CLONE
)
390 unsigned long new_pid
;
391 int ret
, status
= W_STOPCODE (SIGSTOP
);
393 ptrace (PTRACE_GETEVENTMSG
, lwpid_of (event_child
), 0, &new_pid
);
395 /* If we haven't already seen the new PID stop, wait for it now. */
396 if (! pull_pid_from_list (&stopped_pids
, new_pid
))
398 /* The new child has a pending SIGSTOP. We can't affect it until it
399 hits the SIGSTOP, but we're already attached. */
401 ret
= my_waitpid (new_pid
, &status
, __WALL
);
404 perror_with_name ("waiting for new child");
405 else if (ret
!= new_pid
)
406 warning ("wait returned unexpected PID %d", ret
);
407 else if (!WIFSTOPPED (status
))
408 warning ("wait returned unexpected status 0x%x", status
);
411 ptrace (PTRACE_SETOPTIONS
, new_pid
, 0, (PTRACE_ARG4_TYPE
) PTRACE_O_TRACECLONE
);
413 ptid
= ptid_build (pid_of (event_child
), new_pid
, 0);
414 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
415 add_thread (ptid
, new_lwp
);
417 /* Either we're going to immediately resume the new thread
418 or leave it stopped. linux_resume_one_lwp is a nop if it
419 thinks the thread is currently running, so set this first
420 before calling linux_resume_one_lwp. */
421 new_lwp
->stopped
= 1;
423 /* Normally we will get the pending SIGSTOP. But in some cases
424 we might get another signal delivered to the group first.
425 If we do get another signal, be sure not to lose it. */
426 if (WSTOPSIG (status
) == SIGSTOP
)
428 if (stopping_threads
)
429 new_lwp
->stop_pc
= get_stop_pc (new_lwp
);
431 linux_resume_one_lwp (new_lwp
, 0, 0, NULL
);
435 new_lwp
->stop_expected
= 1;
437 if (stopping_threads
)
439 new_lwp
->stop_pc
= get_stop_pc (new_lwp
);
440 new_lwp
->status_pending_p
= 1;
441 new_lwp
->status_pending
= status
;
444 /* Pass the signal on. This is what GDB does - except
445 shouldn't we really report it instead? */
446 linux_resume_one_lwp (new_lwp
, 0, WSTOPSIG (status
), NULL
);
449 /* Always resume the current thread. If we are stopping
450 threads, it will have a pending SIGSTOP; we may as well
452 linux_resume_one_lwp (event_child
, event_child
->stepping
, 0, NULL
);
456 /* Return the PC as read from the regcache of LWP, without any
460 get_pc (struct lwp_info
*lwp
)
462 struct thread_info
*saved_inferior
;
463 struct regcache
*regcache
;
466 if (the_low_target
.get_pc
== NULL
)
469 saved_inferior
= current_inferior
;
470 current_inferior
= get_lwp_thread (lwp
);
472 regcache
= get_thread_regcache (current_inferior
, 1);
473 pc
= (*the_low_target
.get_pc
) (regcache
);
476 fprintf (stderr
, "pc is 0x%lx\n", (long) pc
);
478 current_inferior
= saved_inferior
;
482 /* This function should only be called if LWP got a SIGTRAP.
483 The SIGTRAP could mean several things.
485 On i386, where decr_pc_after_break is non-zero:
486 If we were single-stepping this process using PTRACE_SINGLESTEP,
487 we will get only the one SIGTRAP (even if the instruction we
488 stepped over was a breakpoint). The value of $eip will be the
490 If we continue the process using PTRACE_CONT, we will get a
491 SIGTRAP when we hit a breakpoint. The value of $eip will be
492 the instruction after the breakpoint (i.e. needs to be
493 decremented). If we report the SIGTRAP to GDB, we must also
494 report the undecremented PC. If we cancel the SIGTRAP, we
495 must resume at the decremented PC.
497 (Presumably, not yet tested) On a non-decr_pc_after_break machine
498 with hardware or kernel single-step:
499 If we single-step over a breakpoint instruction, our PC will
500 point at the following instruction. If we continue and hit a
501 breakpoint instruction, our PC will point at the breakpoint
505 get_stop_pc (struct lwp_info
*lwp
)
509 if (the_low_target
.get_pc
== NULL
)
512 stop_pc
= get_pc (lwp
);
514 if (WSTOPSIG (lwp
->last_status
) == SIGTRAP
&& !lwp
->stepping
)
515 stop_pc
-= the_low_target
.decr_pc_after_break
;
518 fprintf (stderr
, "stop pc is 0x%lx\n", (long) stop_pc
);
524 add_lwp (ptid_t ptid
)
526 struct lwp_info
*lwp
;
528 lwp
= (struct lwp_info
*) xmalloc (sizeof (*lwp
));
529 memset (lwp
, 0, sizeof (*lwp
));
533 lwp
->last_resume_kind
= resume_continue
;
535 if (the_low_target
.new_thread
!= NULL
)
536 lwp
->arch_private
= the_low_target
.new_thread ();
538 add_inferior_to_list (&all_lwps
, &lwp
->head
);
543 /* Start an inferior process and returns its pid.
544 ALLARGS is a vector of program-name and args. */
547 linux_create_inferior (char *program
, char **allargs
)
549 struct lwp_info
*new_lwp
;
553 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
559 perror_with_name ("fork");
563 ptrace (PTRACE_TRACEME
, 0, 0, 0);
565 #ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
566 signal (__SIGRTMIN
+ 1, SIG_DFL
);
571 execv (program
, allargs
);
573 execvp (program
, allargs
);
575 fprintf (stderr
, "Cannot exec %s: %s.\n", program
,
581 linux_add_process (pid
, 0);
583 ptid
= ptid_build (pid
, pid
, 0);
584 new_lwp
= add_lwp (ptid
);
585 add_thread (ptid
, new_lwp
);
586 new_lwp
->must_set_ptrace_flags
= 1;
591 /* Attach to an inferior process. */
594 linux_attach_lwp_1 (unsigned long lwpid
, int initial
)
597 struct lwp_info
*new_lwp
;
599 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) != 0)
603 /* If we fail to attach to an LWP, just warn. */
604 fprintf (stderr
, "Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
605 strerror (errno
), errno
);
610 /* If we fail to attach to a process, report an error. */
611 error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
612 strerror (errno
), errno
);
616 /* NOTE/FIXME: This lwp might have not been the tgid. */
617 ptid
= ptid_build (lwpid
, lwpid
, 0);
620 /* Note that extracting the pid from the current inferior is
621 safe, since we're always called in the context of the same
622 process as this new thread. */
623 int pid
= pid_of (get_thread_lwp (current_inferior
));
624 ptid
= ptid_build (pid
, lwpid
, 0);
627 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
628 add_thread (ptid
, new_lwp
);
630 /* We need to wait for SIGSTOP before being able to make the next
631 ptrace call on this LWP. */
632 new_lwp
->must_set_ptrace_flags
= 1;
634 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
637 There are several cases to consider here:
639 1) gdbserver has already attached to the process and is being notified
640 of a new thread that is being created.
641 In this case we should ignore that SIGSTOP and resume the
642 process. This is handled below by setting stop_expected = 1,
643 and the fact that add_lwp sets last_resume_kind ==
646 2) This is the first thread (the process thread), and we're attaching
647 to it via attach_inferior.
648 In this case we want the process thread to stop.
649 This is handled by having linux_attach set last_resume_kind ==
650 resume_stop after we return.
651 ??? If the process already has several threads we leave the other
654 3) GDB is connecting to gdbserver and is requesting an enumeration of all
656 In this case we want the thread to stop.
657 FIXME: This case is currently not properly handled.
658 We should wait for the SIGSTOP but don't. Things work apparently
659 because enough time passes between when we ptrace (ATTACH) and when
660 gdb makes the next ptrace call on the thread.
662 On the other hand, if we are currently trying to stop all threads, we
663 should treat the new thread as if we had sent it a SIGSTOP. This works
664 because we are guaranteed that the add_lwp call above added us to the
665 end of the list, and so the new thread has not yet reached
666 wait_for_sigstop (but will). */
667 new_lwp
->stop_expected
= 1;
671 linux_attach_lwp (unsigned long lwpid
)
673 linux_attach_lwp_1 (lwpid
, 0);
677 linux_attach (unsigned long pid
)
679 struct lwp_info
*lwp
;
681 linux_attach_lwp_1 (pid
, 1);
683 linux_add_process (pid
, 1);
687 /* Don't ignore the initial SIGSTOP if we just attached to this
688 process. It will be collected by wait shortly. */
689 lwp
= (struct lwp_info
*) find_inferior_id (&all_lwps
,
690 ptid_build (pid
, pid
, 0));
691 lwp
->last_resume_kind
= resume_stop
;
704 second_thread_of_pid_p (struct inferior_list_entry
*entry
, void *args
)
706 struct counter
*counter
= args
;
708 if (ptid_get_pid (entry
->id
) == counter
->pid
)
710 if (++counter
->count
> 1)
718 last_thread_of_process_p (struct thread_info
*thread
)
720 ptid_t ptid
= ((struct inferior_list_entry
*)thread
)->id
;
721 int pid
= ptid_get_pid (ptid
);
722 struct counter counter
= { pid
, 0 };
724 return (find_inferior (&all_threads
,
725 second_thread_of_pid_p
, &counter
) == NULL
);
728 /* Kill the inferior lwp. */
731 linux_kill_one_lwp (struct inferior_list_entry
*entry
, void *args
)
733 struct thread_info
*thread
= (struct thread_info
*) entry
;
734 struct lwp_info
*lwp
= get_thread_lwp (thread
);
736 int pid
= * (int *) args
;
738 if (ptid_get_pid (entry
->id
) != pid
)
741 /* We avoid killing the first thread here, because of a Linux kernel (at
742 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
743 the children get a chance to be reaped, it will remain a zombie
746 if (lwpid_of (lwp
) == pid
)
749 fprintf (stderr
, "lkop: is last of process %s\n",
750 target_pid_to_str (entry
->id
));
754 /* If we're killing a running inferior, make sure it is stopped
755 first, as PTRACE_KILL will not work otherwise. */
757 send_sigstop (&lwp
->head
);
761 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
763 /* Make sure it died. The loop is most likely unnecessary. */
764 pid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
765 } while (pid
> 0 && WIFSTOPPED (wstat
));
773 struct process_info
*process
;
774 struct lwp_info
*lwp
;
775 struct thread_info
*thread
;
779 process
= find_process_pid (pid
);
783 find_inferior (&all_threads
, linux_kill_one_lwp
, &pid
);
785 /* See the comment in linux_kill_one_lwp. We did not kill the first
786 thread in the list, so do so now. */
787 lwp
= find_lwp_pid (pid_to_ptid (pid
));
788 thread
= get_lwp_thread (lwp
);
791 fprintf (stderr
, "lk_1: killing lwp %ld, for pid: %d\n",
792 lwpid_of (lwp
), pid
);
794 /* If we're killing a running inferior, make sure it is stopped
795 first, as PTRACE_KILL will not work otherwise. */
797 send_sigstop (&lwp
->head
);
801 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
803 /* Make sure it died. The loop is most likely unnecessary. */
804 lwpid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
805 } while (lwpid
> 0 && WIFSTOPPED (wstat
));
808 thread_db_free (process
, 0);
811 linux_remove_process (process
);
816 linux_detach_one_lwp (struct inferior_list_entry
*entry
, void *args
)
818 struct thread_info
*thread
= (struct thread_info
*) entry
;
819 struct lwp_info
*lwp
= get_thread_lwp (thread
);
820 int pid
= * (int *) args
;
822 if (ptid_get_pid (entry
->id
) != pid
)
825 /* If we're detaching from a running inferior, make sure it is
826 stopped first, as PTRACE_DETACH will not work otherwise. */
829 int lwpid
= lwpid_of (lwp
);
831 stopping_threads
= 1;
832 send_sigstop (&lwp
->head
);
834 /* If this detects a new thread through a clone event, the new
835 thread is appended to the end of the lwp list, so we'll
836 eventually detach from it. */
837 wait_for_sigstop (&lwp
->head
);
838 stopping_threads
= 0;
840 /* If LWP exits while we're trying to stop it, there's nothing
842 lwp
= find_lwp_pid (pid_to_ptid (lwpid
));
847 /* If this process is stopped but is expecting a SIGSTOP, then make
848 sure we take care of that now. This isn't absolutely guaranteed
849 to collect the SIGSTOP, but is fairly likely to. */
850 if (lwp
->stop_expected
)
853 /* Clear stop_expected, so that the SIGSTOP will be reported. */
854 lwp
->stop_expected
= 0;
856 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
857 linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
860 /* Flush any pending changes to the process's registers. */
861 regcache_invalidate_one ((struct inferior_list_entry
*)
862 get_lwp_thread (lwp
));
864 /* Finally, let it resume. */
865 ptrace (PTRACE_DETACH
, lwpid_of (lwp
), 0, 0);
872 any_thread_of (struct inferior_list_entry
*entry
, void *args
)
876 if (ptid_get_pid (entry
->id
) == *pid_p
)
883 linux_detach (int pid
)
885 struct process_info
*process
;
887 process
= find_process_pid (pid
);
892 thread_db_free (process
, 1);
896 (struct thread_info
*) find_inferior (&all_threads
, any_thread_of
, &pid
);
898 delete_all_breakpoints ();
899 find_inferior (&all_threads
, linux_detach_one_lwp
, &pid
);
900 linux_remove_process (process
);
908 struct process_info
*process
;
910 process
= find_process_pid (pid
);
915 ret
= my_waitpid (pid
, &status
, 0);
916 if (WIFEXITED (status
) || WIFSIGNALED (status
))
918 } while (ret
!= -1 || errno
!= ECHILD
);
921 /* Return nonzero if the given thread is still alive. */
923 linux_thread_alive (ptid_t ptid
)
925 struct lwp_info
*lwp
= find_lwp_pid (ptid
);
927 /* We assume we always know if a thread exits. If a whole process
928 exited but we still haven't been able to report it to GDB, we'll
929 hold on to the last lwp of the dead process. */
936 /* Return 1 if this lwp has an interesting status pending. */
938 status_pending_p_callback (struct inferior_list_entry
*entry
, void *arg
)
940 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
941 ptid_t ptid
= * (ptid_t
*) arg
;
942 struct thread_info
*thread
= get_lwp_thread (lwp
);
944 /* Check if we're only interested in events from a specific process
946 if (!ptid_equal (minus_one_ptid
, ptid
)
947 && ptid_get_pid (ptid
) != ptid_get_pid (lwp
->head
.id
))
950 thread
= get_lwp_thread (lwp
);
952 /* If we got a `vCont;t', but we haven't reported a stop yet, do
953 report any status pending the LWP may have. */
954 if (lwp
->last_resume_kind
== resume_stop
955 && thread
->last_status
.kind
== TARGET_WAITKIND_STOPPED
)
958 return lwp
->status_pending_p
;
962 same_lwp (struct inferior_list_entry
*entry
, void *data
)
964 ptid_t ptid
= *(ptid_t
*) data
;
967 if (ptid_get_lwp (ptid
) != 0)
968 lwp
= ptid_get_lwp (ptid
);
970 lwp
= ptid_get_pid (ptid
);
972 if (ptid_get_lwp (entry
->id
) == lwp
)
979 find_lwp_pid (ptid_t ptid
)
981 return (struct lwp_info
*) find_inferior (&all_lwps
, same_lwp
, &ptid
);
984 static struct lwp_info
*
985 linux_wait_for_lwp (ptid_t ptid
, int *wstatp
, int options
)
988 int to_wait_for
= -1;
989 struct lwp_info
*child
= NULL
;
992 fprintf (stderr
, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid
));
994 if (ptid_equal (ptid
, minus_one_ptid
))
995 to_wait_for
= -1; /* any child */
997 to_wait_for
= ptid_get_lwp (ptid
); /* this lwp only */
1003 ret
= my_waitpid (to_wait_for
, wstatp
, options
);
1004 if (ret
== 0 || (ret
== -1 && errno
== ECHILD
&& (options
& WNOHANG
)))
1007 perror_with_name ("waitpid");
1010 && (!WIFSTOPPED (*wstatp
)
1011 || (WSTOPSIG (*wstatp
) != 32
1012 && WSTOPSIG (*wstatp
) != 33)))
1013 fprintf (stderr
, "Got an event from %d (%x)\n", ret
, *wstatp
);
1015 child
= find_lwp_pid (pid_to_ptid (ret
));
1017 /* If we didn't find a process, one of two things presumably happened:
1018 - A process we started and then detached from has exited. Ignore it.
1019 - A process we are controlling has forked and the new child's stop
1020 was reported to us by the kernel. Save its PID. */
1021 if (child
== NULL
&& WIFSTOPPED (*wstatp
))
1023 add_pid_to_list (&stopped_pids
, ret
);
1026 else if (child
== NULL
)
1031 child
->last_status
= *wstatp
;
1033 /* Architecture-specific setup after inferior is running.
1034 This needs to happen after we have attached to the inferior
1035 and it is stopped for the first time, but before we access
1036 any inferior registers. */
1039 the_low_target
.arch_setup ();
1040 #ifdef HAVE_LINUX_REGSETS
1041 memset (disabled_regsets
, 0, num_regsets
);
1046 /* Fetch the possibly triggered data watchpoint info and store it in
1049 On some archs, like x86, that use debug registers to set
1050 watchpoints, it's possible that the way to know which watched
1051 address trapped, is to check the register that is used to select
1052 which address to watch. Problem is, between setting the
1053 watchpoint and reading back which data address trapped, the user
1054 may change the set of watchpoints, and, as a consequence, GDB
1055 changes the debug registers in the inferior. To avoid reading
1056 back a stale stopped-data-address when that happens, we cache in
1057 LP the fact that a watchpoint trapped, and the corresponding data
1058 address, as soon as we see CHILD stop with a SIGTRAP. If GDB
1059 changes the debug registers meanwhile, we have the cached data we
1062 if (WIFSTOPPED (*wstatp
) && WSTOPSIG (*wstatp
) == SIGTRAP
)
1064 if (the_low_target
.stopped_by_watchpoint
== NULL
)
1066 child
->stopped_by_watchpoint
= 0;
1070 struct thread_info
*saved_inferior
;
1072 saved_inferior
= current_inferior
;
1073 current_inferior
= get_lwp_thread (child
);
1075 child
->stopped_by_watchpoint
1076 = the_low_target
.stopped_by_watchpoint ();
1078 if (child
->stopped_by_watchpoint
)
1080 if (the_low_target
.stopped_data_address
!= NULL
)
1081 child
->stopped_data_address
1082 = the_low_target
.stopped_data_address ();
1084 child
->stopped_data_address
= 0;
1087 current_inferior
= saved_inferior
;
1091 /* Store the STOP_PC, with adjustment applied. This depends on the
1092 architecture being defined already (so that CHILD has a valid
1093 regcache), and on LAST_STATUS being set (to check for SIGTRAP or
1095 if (WIFSTOPPED (*wstatp
))
1096 child
->stop_pc
= get_stop_pc (child
);
1099 && WIFSTOPPED (*wstatp
)
1100 && the_low_target
.get_pc
!= NULL
)
1102 struct thread_info
*saved_inferior
= current_inferior
;
1103 struct regcache
*regcache
;
1106 current_inferior
= get_lwp_thread (child
);
1107 regcache
= get_thread_regcache (current_inferior
, 1);
1108 pc
= (*the_low_target
.get_pc
) (regcache
);
1109 fprintf (stderr
, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc
);
1110 current_inferior
= saved_inferior
;
1116 /* Arrange for a breakpoint to be hit again later. We don't keep the
1117 SIGTRAP status and don't forward the SIGTRAP signal to the LWP. We
1118 will handle the current event, eventually we will resume this LWP,
1119 and this breakpoint will trap again. */
1122 cancel_breakpoint (struct lwp_info
*lwp
)
1124 struct thread_info
*saved_inferior
;
1125 struct regcache
*regcache
;
1127 /* There's nothing to do if we don't support breakpoints. */
1128 if (!supports_breakpoints ())
1135 "CB: [%s] is stepping\n",
1136 target_pid_to_str (lwp
->head
.id
));
1140 regcache
= get_thread_regcache (get_lwp_thread (lwp
), 1);
1142 /* breakpoint_at reads from current inferior. */
1143 saved_inferior
= current_inferior
;
1144 current_inferior
= get_lwp_thread (lwp
);
1146 if ((*the_low_target
.breakpoint_at
) (lwp
->stop_pc
))
1150 "CB: Push back breakpoint for %s\n",
1151 target_pid_to_str (lwp
->head
.id
));
1153 /* Back up the PC if necessary. */
1154 if (the_low_target
.decr_pc_after_break
)
1156 struct regcache
*regcache
1157 = get_thread_regcache (get_lwp_thread (lwp
), 1);
1158 (*the_low_target
.set_pc
) (regcache
, lwp
->stop_pc
);
1161 current_inferior
= saved_inferior
;
1168 "CB: No breakpoint found at %s for [%s]\n",
1169 paddress (lwp
->stop_pc
),
1170 target_pid_to_str (lwp
->head
.id
));
1173 current_inferior
= saved_inferior
;
1177 /* When the event-loop is doing a step-over, this points at the thread
1179 ptid_t step_over_bkpt
;
1181 /* Wait for an event from child PID. If PID is -1, wait for any
1182 child. Store the stop status through the status pointer WSTAT.
1183 OPTIONS is passed to the waitpid call. Return 0 if no child stop
1184 event was found and OPTIONS contains WNOHANG. Return the PID of
1185 the stopped child otherwise. */
1188 linux_wait_for_event_1 (ptid_t ptid
, int *wstat
, int options
)
1190 struct lwp_info
*event_child
, *requested_child
;
1193 requested_child
= NULL
;
1195 /* Check for a lwp with a pending status. */
1197 if (ptid_equal (ptid
, minus_one_ptid
)
1198 || ptid_equal (pid_to_ptid (ptid_get_pid (ptid
)), ptid
))
1200 event_child
= (struct lwp_info
*)
1201 find_inferior (&all_lwps
, status_pending_p_callback
, &ptid
);
1202 if (debug_threads
&& event_child
)
1203 fprintf (stderr
, "Got a pending child %ld\n", lwpid_of (event_child
));
1207 requested_child
= find_lwp_pid (ptid
);
1209 if (requested_child
->status_pending_p
)
1210 event_child
= requested_child
;
1213 if (event_child
!= NULL
)
1216 fprintf (stderr
, "Got an event from pending child %ld (%04x)\n",
1217 lwpid_of (event_child
), event_child
->status_pending
);
1218 *wstat
= event_child
->status_pending
;
1219 event_child
->status_pending_p
= 0;
1220 event_child
->status_pending
= 0;
1221 current_inferior
= get_lwp_thread (event_child
);
1222 return lwpid_of (event_child
);
1225 /* We only enter this loop if no process has a pending wait status. Thus
1226 any action taken in response to a wait status inside this loop is
1227 responding as soon as we detect the status, not after any pending
1231 event_child
= linux_wait_for_lwp (ptid
, wstat
, options
);
1233 if ((options
& WNOHANG
) && event_child
== NULL
)
1236 fprintf (stderr
, "WNOHANG set, no event found\n");
1240 if (event_child
== NULL
)
1241 error ("event from unknown child");
1243 current_inferior
= get_lwp_thread (event_child
);
1245 /* Check for thread exit. */
1246 if (! WIFSTOPPED (*wstat
))
1249 fprintf (stderr
, "LWP %ld exiting\n", lwpid_of (event_child
));
1251 /* If the last thread is exiting, just return. */
1252 if (last_thread_of_process_p (current_inferior
))
1255 fprintf (stderr
, "LWP %ld is last lwp of process\n",
1256 lwpid_of (event_child
));
1257 return lwpid_of (event_child
);
1262 current_inferior
= (struct thread_info
*) all_threads
.head
;
1264 fprintf (stderr
, "Current inferior is now %ld\n",
1265 lwpid_of (get_thread_lwp (current_inferior
)));
1269 current_inferior
= NULL
;
1271 fprintf (stderr
, "Current inferior is now <NULL>\n");
1274 /* If we were waiting for this particular child to do something...
1275 well, it did something. */
1276 if (requested_child
!= NULL
)
1278 int lwpid
= lwpid_of (event_child
);
1280 /* Cancel the step-over operation --- the thread that
1281 started it is gone. */
1282 if (finish_step_over (event_child
))
1283 unstop_all_lwps (event_child
);
1284 delete_lwp (event_child
);
1288 delete_lwp (event_child
);
1290 /* Wait for a more interesting event. */
1294 if (event_child
->must_set_ptrace_flags
)
1296 ptrace (PTRACE_SETOPTIONS
, lwpid_of (event_child
),
1297 0, (PTRACE_ARG4_TYPE
) PTRACE_O_TRACECLONE
);
1298 event_child
->must_set_ptrace_flags
= 0;
1301 if (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) == SIGTRAP
1302 && *wstat
>> 16 != 0)
1304 handle_extended_wait (event_child
, *wstat
);
1308 /* If GDB is not interested in this signal, don't stop other
1309 threads, and don't report it to GDB. Just resume the
1310 inferior right away. We do this for threading-related
1311 signals as well as any that GDB specifically requested we
1312 ignore. But never ignore SIGSTOP if we sent it ourselves,
1313 and do not ignore signals when stepping - they may require
1314 special handling to skip the signal handler. */
1315 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
1317 if (WIFSTOPPED (*wstat
)
1318 && !event_child
->stepping
1320 #if defined (USE_THREAD_DB) && defined (__SIGRTMIN)
1321 (current_process ()->private->thread_db
!= NULL
1322 && (WSTOPSIG (*wstat
) == __SIGRTMIN
1323 || WSTOPSIG (*wstat
) == __SIGRTMIN
+ 1))
1326 (pass_signals
[target_signal_from_host (WSTOPSIG (*wstat
))]
1327 && !(WSTOPSIG (*wstat
) == SIGSTOP
1328 && event_child
->stop_expected
))))
1330 siginfo_t info
, *info_p
;
1333 fprintf (stderr
, "Ignored signal %d for LWP %ld.\n",
1334 WSTOPSIG (*wstat
), lwpid_of (event_child
));
1336 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (event_child
), 0, &info
) == 0)
1340 linux_resume_one_lwp (event_child
, event_child
->stepping
,
1341 WSTOPSIG (*wstat
), info_p
);
1345 if (WIFSTOPPED (*wstat
)
1346 && WSTOPSIG (*wstat
) == SIGSTOP
1347 && event_child
->stop_expected
)
1352 fprintf (stderr
, "Expected stop.\n");
1353 event_child
->stop_expected
= 0;
1355 should_stop
= (event_child
->last_resume_kind
== resume_stop
1356 || stopping_threads
);
1360 linux_resume_one_lwp (event_child
,
1361 event_child
->stepping
, 0, NULL
);
1366 return lwpid_of (event_child
);
1374 linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
)
1378 if (ptid_is_pid (ptid
))
1380 /* A request to wait for a specific tgid. This is not possible
1381 with waitpid, so instead, we wait for any child, and leave
1382 children we're not interested in right now with a pending
1383 status to report later. */
1384 wait_ptid
= minus_one_ptid
;
1393 event_pid
= linux_wait_for_event_1 (wait_ptid
, wstat
, options
);
1396 && ptid_is_pid (ptid
) && ptid_get_pid (ptid
) != event_pid
)
1398 struct lwp_info
*event_child
= find_lwp_pid (pid_to_ptid (event_pid
));
1400 if (! WIFSTOPPED (*wstat
))
1401 mark_lwp_dead (event_child
, *wstat
);
1404 event_child
->status_pending_p
= 1;
1405 event_child
->status_pending
= *wstat
;
1414 /* Count the LWP's that have had events. */
1417 count_events_callback (struct inferior_list_entry
*entry
, void *data
)
1419 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1422 gdb_assert (count
!= NULL
);
1424 /* Count only resumed LWPs that have a SIGTRAP event pending that
1425 should be reported to GDB. */
1426 if (get_lwp_thread (lp
)->last_status
.kind
== TARGET_WAITKIND_IGNORE
1427 && lp
->last_resume_kind
!= resume_stop
1428 && lp
->status_pending_p
1429 && WIFSTOPPED (lp
->status_pending
)
1430 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1431 && !breakpoint_inserted_here (lp
->stop_pc
))
1437 /* Select the LWP (if any) that is currently being single-stepped. */
1440 select_singlestep_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
1442 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1444 if (get_lwp_thread (lp
)->last_status
.kind
== TARGET_WAITKIND_IGNORE
1445 && lp
->last_resume_kind
== resume_step
1446 && lp
->status_pending_p
)
1452 /* Select the Nth LWP that has had a SIGTRAP event that should be
1456 select_event_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
1458 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1459 int *selector
= data
;
1461 gdb_assert (selector
!= NULL
);
1463 /* Select only resumed LWPs that have a SIGTRAP event pending. */
1464 if (lp
->last_resume_kind
!= resume_stop
1465 && get_lwp_thread (lp
)->last_status
.kind
== TARGET_WAITKIND_IGNORE
1466 && lp
->status_pending_p
1467 && WIFSTOPPED (lp
->status_pending
)
1468 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1469 && !breakpoint_inserted_here (lp
->stop_pc
))
1470 if ((*selector
)-- == 0)
1477 cancel_breakpoints_callback (struct inferior_list_entry
*entry
, void *data
)
1479 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1480 struct lwp_info
*event_lp
= data
;
1482 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
1486 /* If a LWP other than the LWP that we're reporting an event for has
1487 hit a GDB breakpoint (as opposed to some random trap signal),
1488 then just arrange for it to hit it again later. We don't keep
1489 the SIGTRAP status and don't forward the SIGTRAP signal to the
1490 LWP. We will handle the current event, eventually we will resume
1491 all LWPs, and this one will get its breakpoint trap again.
1493 If we do not do this, then we run the risk that the user will
1494 delete or disable the breakpoint, but the LWP will have already
1497 if (lp
->last_resume_kind
!= resume_stop
1498 && get_lwp_thread (lp
)->last_status
.kind
== TARGET_WAITKIND_IGNORE
1499 && lp
->status_pending_p
1500 && WIFSTOPPED (lp
->status_pending
)
1501 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1502 && cancel_breakpoint (lp
))
1503 /* Throw away the SIGTRAP. */
1504 lp
->status_pending_p
= 0;
1509 /* Select one LWP out of those that have events pending. */
1512 select_event_lwp (struct lwp_info
**orig_lp
)
1515 int random_selector
;
1516 struct lwp_info
*event_lp
;
1518 /* Give preference to any LWP that is being single-stepped. */
1520 = (struct lwp_info
*) find_inferior (&all_lwps
,
1521 select_singlestep_lwp_callback
, NULL
);
1522 if (event_lp
!= NULL
)
1526 "SEL: Select single-step %s\n",
1527 target_pid_to_str (ptid_of (event_lp
)));
1531 /* No single-stepping LWP. Select one at random, out of those
1532 which have had SIGTRAP events. */
1534 /* First see how many SIGTRAP events we have. */
1535 find_inferior (&all_lwps
, count_events_callback
, &num_events
);
1537 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
1538 random_selector
= (int)
1539 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
1541 if (debug_threads
&& num_events
> 1)
1543 "SEL: Found %d SIGTRAP events, selecting #%d\n",
1544 num_events
, random_selector
);
1546 event_lp
= (struct lwp_info
*) find_inferior (&all_lwps
,
1547 select_event_lwp_callback
,
1551 if (event_lp
!= NULL
)
1553 /* Switch the event LWP. */
1554 *orig_lp
= event_lp
;
1558 /* Set this inferior LWP's state as "want-stopped". We won't resume
1559 this LWP until the client gives us another action for it. */
1562 gdb_wants_lwp_stopped (struct inferior_list_entry
*entry
)
1564 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1565 struct thread_info
*thread
= get_lwp_thread (lwp
);
1567 /* Most threads are stopped implicitly (all-stop); tag that with
1568 signal 0. The thread being explicitly reported stopped to the
1569 client, gets it's status fixed up afterwards. */
1570 thread
->last_status
.kind
= TARGET_WAITKIND_STOPPED
;
1571 thread
->last_status
.value
.sig
= TARGET_SIGNAL_0
;
1573 lwp
->last_resume_kind
= resume_stop
;
1576 /* Set all LWP's states as "want-stopped". */
1579 gdb_wants_all_stopped (void)
1581 for_each_inferior (&all_lwps
, gdb_wants_lwp_stopped
);
1584 /* Wait for process, returns status. */
1587 linux_wait_1 (ptid_t ptid
,
1588 struct target_waitstatus
*ourstatus
, int target_options
)
1591 struct thread_info
*thread
= NULL
;
1592 struct lwp_info
*event_child
= NULL
;
1595 int step_over_finished
;
1596 int bp_explains_trap
;
1597 int maybe_internal_trap
;
1600 /* Translate generic target options into linux options. */
1602 if (target_options
& TARGET_WNOHANG
)
1606 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
1608 /* If we were only supposed to resume one thread, only wait for
1609 that thread - if it's still alive. If it died, however - which
1610 can happen if we're coming from the thread death case below -
1611 then we need to make sure we restart the other threads. We could
1612 pick a thread at random or restart all; restarting all is less
1615 && !ptid_equal (cont_thread
, null_ptid
)
1616 && !ptid_equal (cont_thread
, minus_one_ptid
))
1618 thread
= (struct thread_info
*) find_inferior_id (&all_threads
,
1621 /* No stepping, no signal - unless one is pending already, of course. */
1624 struct thread_resume resume_info
;
1625 resume_info
.thread
= minus_one_ptid
;
1626 resume_info
.kind
= resume_continue
;
1627 resume_info
.sig
= 0;
1628 linux_resume (&resume_info
, 1);
1634 if (ptid_equal (step_over_bkpt
, null_ptid
))
1635 pid
= linux_wait_for_event (ptid
, &w
, options
);
1639 fprintf (stderr
, "step_over_bkpt set [%s], doing a blocking wait\n",
1640 target_pid_to_str (step_over_bkpt
));
1641 pid
= linux_wait_for_event (step_over_bkpt
, &w
, options
& ~WNOHANG
);
1644 if (pid
== 0) /* only if TARGET_WNOHANG */
1647 event_child
= get_thread_lwp (current_inferior
);
1649 /* If we are waiting for a particular child, and it exited,
1650 linux_wait_for_event will return its exit status. Similarly if
1651 the last child exited. If this is not the last child, however,
1652 do not report it as exited until there is a 'thread exited' response
1653 available in the remote protocol. Instead, just wait for another event.
1654 This should be safe, because if the thread crashed we will already
1655 have reported the termination signal to GDB; that should stop any
1656 in-progress stepping operations, etc.
1658 Report the exit status of the last thread to exit. This matches
1659 LinuxThreads' behavior. */
1661 if (last_thread_of_process_p (current_inferior
))
1663 if (WIFEXITED (w
) || WIFSIGNALED (w
))
1665 int pid
= pid_of (event_child
);
1666 struct process_info
*process
= find_process_pid (pid
);
1668 #ifdef USE_THREAD_DB
1669 thread_db_free (process
, 0);
1671 delete_lwp (event_child
);
1672 linux_remove_process (process
);
1674 current_inferior
= NULL
;
1678 ourstatus
->kind
= TARGET_WAITKIND_EXITED
;
1679 ourstatus
->value
.integer
= WEXITSTATUS (w
);
1682 fprintf (stderr
, "\nChild exited with retcode = %x \n", WEXITSTATUS (w
));
1686 ourstatus
->kind
= TARGET_WAITKIND_SIGNALLED
;
1687 ourstatus
->value
.sig
= target_signal_from_host (WTERMSIG (w
));
1690 fprintf (stderr
, "\nChild terminated with signal = %x \n", WTERMSIG (w
));
1694 return pid_to_ptid (pid
);
1699 if (!WIFSTOPPED (w
))
1703 /* If this event was not handled before, and is not a SIGTRAP, we
1704 report it. SIGILL and SIGSEGV are also treated as traps in case
1705 a breakpoint is inserted at the current PC. If this target does
1706 not support internal breakpoints at all, we also report the
1707 SIGTRAP without further processing; it's of no concern to us. */
1709 = (supports_breakpoints ()
1710 && (WSTOPSIG (w
) == SIGTRAP
1711 || ((WSTOPSIG (w
) == SIGILL
1712 || WSTOPSIG (w
) == SIGSEGV
)
1713 && (*the_low_target
.breakpoint_at
) (event_child
->stop_pc
))));
1715 if (maybe_internal_trap
)
1717 /* Handle anything that requires bookkeeping before deciding to
1718 report the event or continue waiting. */
1720 /* First check if we can explain the SIGTRAP with an internal
1721 breakpoint, or if we should possibly report the event to GDB.
1722 Do this before anything that may remove or insert a
1724 bp_explains_trap
= breakpoint_inserted_here (event_child
->stop_pc
);
1726 /* We have a SIGTRAP, possibly a step-over dance has just
1727 finished. If so, tweak the state machine accordingly,
1728 reinsert breakpoints and delete any reinsert (software
1729 single-step) breakpoints. */
1730 step_over_finished
= finish_step_over (event_child
);
1732 /* Now invoke the callbacks of any internal breakpoints there. */
1733 check_breakpoints (event_child
->stop_pc
);
1735 if (bp_explains_trap
)
1737 /* If we stepped or ran into an internal breakpoint, we've
1738 already handled it. So next time we resume (from this
1739 PC), we should step over it. */
1741 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
1743 if (breakpoint_here (event_child
->stop_pc
))
1744 event_child
->need_step_over
= 1;
1749 /* We have some other signal, possibly a step-over dance was in
1750 progress, and it should be cancelled too. */
1751 step_over_finished
= finish_step_over (event_child
);
1754 /* We have all the data we need. Either report the event to GDB, or
1755 resume threads and keep waiting for more. */
1757 /* Check If GDB would be interested in this event. If GDB wanted
1758 this thread to single step, we always want to report the SIGTRAP,
1759 and let GDB handle it. Watchpoints should always be reported.
1760 So should signals we can't explain. A SIGTRAP we can't explain
1761 could be a GDB breakpoint --- we may or not support Z0
1762 breakpoints. If we do, we're be able to handle GDB breakpoints
1763 on top of internal breakpoints, by handling the internal
1764 breakpoint and still reporting the event to GDB. If we don't,
1765 we're out of luck, GDB won't see the breakpoint hit. */
1766 report_to_gdb
= (!maybe_internal_trap
1767 || event_child
->last_resume_kind
== resume_step
1768 || event_child
->stopped_by_watchpoint
1769 || (!step_over_finished
&& !bp_explains_trap
)
1770 || gdb_breakpoint_here (event_child
->stop_pc
));
1772 /* We found no reason GDB would want us to stop. We either hit one
1773 of our own breakpoints, or finished an internal step GDB
1774 shouldn't know about. */
1779 if (bp_explains_trap
)
1780 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
1781 if (step_over_finished
)
1782 fprintf (stderr
, "Step-over finished.\n");
1785 /* We're not reporting this breakpoint to GDB, so apply the
1786 decr_pc_after_break adjustment to the inferior's regcache
1789 if (the_low_target
.set_pc
!= NULL
)
1791 struct regcache
*regcache
1792 = get_thread_regcache (get_lwp_thread (event_child
), 1);
1793 (*the_low_target
.set_pc
) (regcache
, event_child
->stop_pc
);
1796 /* We've finished stepping over a breakpoint. We've stopped all
1797 LWPs momentarily except the stepping one. This is where we
1798 resume them all again. We're going to keep waiting, so use
1799 proceed, which handles stepping over the next breakpoint. */
1801 fprintf (stderr
, "proceeding all threads.\n");
1802 proceed_all_lwps ();
1808 if (event_child
->last_resume_kind
== resume_step
)
1809 fprintf (stderr
, "GDB wanted to single-step, reporting event.\n");
1810 if (event_child
->stopped_by_watchpoint
)
1811 fprintf (stderr
, "Stopped by watchpoint.\n");
1812 if (gdb_breakpoint_here (event_child
->stop_pc
))
1813 fprintf (stderr
, "Stopped by GDB breakpoint.\n");
1815 fprintf (stderr
, "Hit a non-gdbserver trap event.\n");
1818 /* Alright, we're going to report a stop. */
1822 /* In all-stop, stop all threads. */
1825 /* If we're not waiting for a specific LWP, choose an event LWP
1826 from among those that have had events. Giving equal priority
1827 to all LWPs that have had events helps prevent
1829 if (ptid_equal (ptid
, minus_one_ptid
))
1831 event_child
->status_pending_p
= 1;
1832 event_child
->status_pending
= w
;
1834 select_event_lwp (&event_child
);
1836 event_child
->status_pending_p
= 0;
1837 w
= event_child
->status_pending
;
1840 /* Now that we've selected our final event LWP, cancel any
1841 breakpoints in other LWPs that have hit a GDB breakpoint.
1842 See the comment in cancel_breakpoints_callback to find out
1844 find_inferior (&all_lwps
, cancel_breakpoints_callback
, event_child
);
1848 /* If we just finished a step-over, then all threads had been
1849 momentarily paused. In all-stop, that's fine, we want
1850 threads stopped by now anyway. In non-stop, we need to
1851 re-resume threads that GDB wanted to be running. */
1852 if (step_over_finished
)
1853 unstop_all_lwps (event_child
);
1856 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
1858 /* Do this before the gdb_wants_all_stopped calls below, since they
1859 always set last_resume_kind to resume_stop. */
1860 if (event_child
->last_resume_kind
== resume_stop
&& WSTOPSIG (w
) == SIGSTOP
)
1862 /* A thread that has been requested to stop by GDB with vCont;t,
1863 and it stopped cleanly, so report as SIG0. The use of
1864 SIGSTOP is an implementation detail. */
1865 ourstatus
->value
.sig
= TARGET_SIGNAL_0
;
1867 else if (event_child
->last_resume_kind
== resume_stop
&& WSTOPSIG (w
) != SIGSTOP
)
1869 /* A thread that has been requested to stop by GDB with vCont;t,
1870 but, it stopped for other reasons. */
1871 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
1875 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
1878 gdb_assert (ptid_equal (step_over_bkpt
, null_ptid
));
1882 /* From GDB's perspective, all-stop mode always stops all
1883 threads implicitly. Tag all threads as "want-stopped". */
1884 gdb_wants_all_stopped ();
1888 /* We're reporting this LWP as stopped. Update it's
1889 "want-stopped" state to what the client wants, until it gets
1890 a new resume action. */
1891 gdb_wants_lwp_stopped (&event_child
->head
);
1895 fprintf (stderr
, "linux_wait ret = %s, %d, %d\n",
1896 target_pid_to_str (ptid_of (event_child
)),
1898 ourstatus
->value
.sig
);
1900 get_lwp_thread (event_child
)->last_status
= *ourstatus
;
1901 return ptid_of (event_child
);
1904 /* Get rid of any pending event in the pipe. */
1906 async_file_flush (void)
1912 ret
= read (linux_event_pipe
[0], &buf
, 1);
1913 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
1916 /* Put something in the pipe, so the event loop wakes up. */
1918 async_file_mark (void)
1922 async_file_flush ();
1925 ret
= write (linux_event_pipe
[1], "+", 1);
1926 while (ret
== 0 || (ret
== -1 && errno
== EINTR
));
1928 /* Ignore EAGAIN. If the pipe is full, the event loop will already
1929 be awakened anyway. */
1933 linux_wait (ptid_t ptid
,
1934 struct target_waitstatus
*ourstatus
, int target_options
)
1939 fprintf (stderr
, "linux_wait: [%s]\n", target_pid_to_str (ptid
));
1941 /* Flush the async file first. */
1942 if (target_is_async_p ())
1943 async_file_flush ();
1945 event_ptid
= linux_wait_1 (ptid
, ourstatus
, target_options
);
1947 /* If at least one stop was reported, there may be more. A single
1948 SIGCHLD can signal more than one child stop. */
1949 if (target_is_async_p ()
1950 && (target_options
& TARGET_WNOHANG
) != 0
1951 && !ptid_equal (event_ptid
, null_ptid
))
1957 /* Send a signal to an LWP. */
1960 kill_lwp (unsigned long lwpid
, int signo
)
1962 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1963 fails, then we are not using nptl threads and we should be using kill. */
1967 static int tkill_failed
;
1974 ret
= syscall (__NR_tkill
, lwpid
, signo
);
1975 if (errno
!= ENOSYS
)
1982 return kill (lwpid
, signo
);
1986 send_sigstop (struct inferior_list_entry
*entry
)
1988 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1994 pid
= lwpid_of (lwp
);
1996 /* If we already have a pending stop signal for this process, don't
1998 if (lwp
->stop_expected
)
2001 fprintf (stderr
, "Have pending sigstop for lwp %d\n", pid
);
2007 fprintf (stderr
, "Sending sigstop to lwp %d\n", pid
);
2009 lwp
->stop_expected
= 1;
2010 kill_lwp (pid
, SIGSTOP
);
2014 mark_lwp_dead (struct lwp_info
*lwp
, int wstat
)
2016 /* It's dead, really. */
2019 /* Store the exit status for later. */
2020 lwp
->status_pending_p
= 1;
2021 lwp
->status_pending
= wstat
;
2023 /* Prevent trying to stop it. */
2026 /* No further stops are expected from a dead lwp. */
2027 lwp
->stop_expected
= 0;
2031 wait_for_sigstop (struct inferior_list_entry
*entry
)
2033 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2034 struct thread_info
*saved_inferior
;
2043 fprintf (stderr
, "wait_for_sigstop: LWP %ld already stopped\n",
2048 saved_inferior
= current_inferior
;
2049 if (saved_inferior
!= NULL
)
2050 saved_tid
= ((struct inferior_list_entry
*) saved_inferior
)->id
;
2052 saved_tid
= null_ptid
; /* avoid bogus unused warning */
2054 ptid
= lwp
->head
.id
;
2057 fprintf (stderr
, "wait_for_sigstop: pulling one event\n");
2059 pid
= linux_wait_for_event (ptid
, &wstat
, __WALL
);
2061 /* If we stopped with a non-SIGSTOP signal, save it for later
2062 and record the pending SIGSTOP. If the process exited, just
2064 if (WIFSTOPPED (wstat
))
2067 fprintf (stderr
, "LWP %ld stopped with signal %d\n",
2068 lwpid_of (lwp
), WSTOPSIG (wstat
));
2070 if (WSTOPSIG (wstat
) != SIGSTOP
)
2073 fprintf (stderr
, "LWP %ld stopped with non-sigstop status %06x\n",
2074 lwpid_of (lwp
), wstat
);
2076 lwp
->status_pending_p
= 1;
2077 lwp
->status_pending
= wstat
;
2083 fprintf (stderr
, "Process %d exited while stopping LWPs\n", pid
);
2085 lwp
= find_lwp_pid (pid_to_ptid (pid
));
2088 /* Leave this status pending for the next time we're able to
2089 report it. In the mean time, we'll report this lwp as
2090 dead to GDB, so GDB doesn't try to read registers and
2091 memory from it. This can only happen if this was the
2092 last thread of the process; otherwise, PID is removed
2093 from the thread tables before linux_wait_for_event
2095 mark_lwp_dead (lwp
, wstat
);
2099 if (saved_inferior
== NULL
|| linux_thread_alive (saved_tid
))
2100 current_inferior
= saved_inferior
;
2104 fprintf (stderr
, "Previously current thread died.\n");
2108 /* We can't change the current inferior behind GDB's back,
2109 otherwise, a subsequent command may apply to the wrong
2111 current_inferior
= NULL
;
2115 /* Set a valid thread as current. */
2116 set_desired_inferior (0);
2122 stop_all_lwps (void)
2124 stopping_threads
= 1;
2125 for_each_inferior (&all_lwps
, send_sigstop
);
2126 for_each_inferior (&all_lwps
, wait_for_sigstop
);
2127 stopping_threads
= 0;
2130 /* Resume execution of the inferior process.
2131 If STEP is nonzero, single-step it.
2132 If SIGNAL is nonzero, give it that signal. */
2135 linux_resume_one_lwp (struct lwp_info
*lwp
,
2136 int step
, int signal
, siginfo_t
*info
)
2138 struct thread_info
*saved_inferior
;
2140 if (lwp
->stopped
== 0)
2143 /* If we have pending signals or status, and a new signal, enqueue the
2144 signal. Also enqueue the signal if we are waiting to reinsert a
2145 breakpoint; it will be picked up again below. */
2147 && (lwp
->status_pending_p
|| lwp
->pending_signals
!= NULL
2148 || lwp
->bp_reinsert
!= 0))
2150 struct pending_signals
*p_sig
;
2151 p_sig
= xmalloc (sizeof (*p_sig
));
2152 p_sig
->prev
= lwp
->pending_signals
;
2153 p_sig
->signal
= signal
;
2155 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
2157 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
2158 lwp
->pending_signals
= p_sig
;
2161 if (lwp
->status_pending_p
)
2164 fprintf (stderr
, "Not resuming lwp %ld (%s, signal %d, stop %s);"
2165 " has pending status\n",
2166 lwpid_of (lwp
), step
? "step" : "continue", signal
,
2167 lwp
->stop_expected
? "expected" : "not expected");
2171 saved_inferior
= current_inferior
;
2172 current_inferior
= get_lwp_thread (lwp
);
2175 fprintf (stderr
, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
2176 lwpid_of (lwp
), step
? "step" : "continue", signal
,
2177 lwp
->stop_expected
? "expected" : "not expected");
2179 /* This bit needs some thinking about. If we get a signal that
2180 we must report while a single-step reinsert is still pending,
2181 we often end up resuming the thread. It might be better to
2182 (ew) allow a stack of pending events; then we could be sure that
2183 the reinsert happened right away and not lose any signals.
2185 Making this stack would also shrink the window in which breakpoints are
2186 uninserted (see comment in linux_wait_for_lwp) but not enough for
2187 complete correctness, so it won't solve that problem. It may be
2188 worthwhile just to solve this one, however. */
2189 if (lwp
->bp_reinsert
!= 0)
2192 fprintf (stderr
, " pending reinsert at 0x%s\n",
2193 paddress (lwp
->bp_reinsert
));
2195 if (lwp
->bp_reinsert
!= 0 && can_hardware_single_step ())
2198 fprintf (stderr
, "BAD - reinserting but not stepping.\n");
2203 /* Postpone any pending signal. It was enqueued above. */
2207 if (debug_threads
&& the_low_target
.get_pc
!= NULL
)
2209 struct regcache
*regcache
= get_thread_regcache (current_inferior
, 1);
2210 CORE_ADDR pc
= (*the_low_target
.get_pc
) (regcache
);
2211 fprintf (stderr
, " resuming from pc 0x%lx\n", (long) pc
);
2214 /* If we have pending signals, consume one unless we are trying to reinsert
2216 if (lwp
->pending_signals
!= NULL
&& lwp
->bp_reinsert
== 0)
2218 struct pending_signals
**p_sig
;
2220 p_sig
= &lwp
->pending_signals
;
2221 while ((*p_sig
)->prev
!= NULL
)
2222 p_sig
= &(*p_sig
)->prev
;
2224 signal
= (*p_sig
)->signal
;
2225 if ((*p_sig
)->info
.si_signo
!= 0)
2226 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &(*p_sig
)->info
);
2232 if (the_low_target
.prepare_to_resume
!= NULL
)
2233 the_low_target
.prepare_to_resume (lwp
);
2235 regcache_invalidate_one ((struct inferior_list_entry
*)
2236 get_lwp_thread (lwp
));
2239 lwp
->stopped_by_watchpoint
= 0;
2240 lwp
->stepping
= step
;
2241 ptrace (step
? PTRACE_SINGLESTEP
: PTRACE_CONT
, lwpid_of (lwp
), 0,
2242 /* Coerce to a uintptr_t first to avoid potential gcc warning
2243 of coercing an 8 byte integer to a 4 byte pointer. */
2244 (PTRACE_ARG4_TYPE
) (uintptr_t) signal
);
2246 current_inferior
= saved_inferior
;
2249 /* ESRCH from ptrace either means that the thread was already
2250 running (an error) or that it is gone (a race condition). If
2251 it's gone, we will get a notification the next time we wait,
2252 so we can ignore the error. We could differentiate these
2253 two, but it's tricky without waiting; the thread still exists
2254 as a zombie, so sending it signal 0 would succeed. So just
2259 perror_with_name ("ptrace");
2263 struct thread_resume_array
2265 struct thread_resume
*resume
;
2269 /* This function is called once per thread. We look up the thread
2270 in RESUME_PTR, and mark the thread with a pointer to the appropriate
2273 This algorithm is O(threads * resume elements), but resume elements
2274 is small (and will remain small at least until GDB supports thread
2277 linux_set_resume_request (struct inferior_list_entry
*entry
, void *arg
)
2279 struct lwp_info
*lwp
;
2280 struct thread_info
*thread
;
2282 struct thread_resume_array
*r
;
2284 thread
= (struct thread_info
*) entry
;
2285 lwp
= get_thread_lwp (thread
);
2288 for (ndx
= 0; ndx
< r
->n
; ndx
++)
2290 ptid_t ptid
= r
->resume
[ndx
].thread
;
2291 if (ptid_equal (ptid
, minus_one_ptid
)
2292 || ptid_equal (ptid
, entry
->id
)
2293 || (ptid_is_pid (ptid
)
2294 && (ptid_get_pid (ptid
) == pid_of (lwp
)))
2295 || (ptid_get_lwp (ptid
) == -1
2296 && (ptid_get_pid (ptid
) == pid_of (lwp
))))
2298 if (r
->resume
[ndx
].kind
== resume_stop
2299 && lwp
->last_resume_kind
== resume_stop
)
2302 fprintf (stderr
, "already %s LWP %ld at GDB's request\n",
2303 thread
->last_status
.kind
== TARGET_WAITKIND_STOPPED
2311 lwp
->resume
= &r
->resume
[ndx
];
2312 lwp
->last_resume_kind
= lwp
->resume
->kind
;
2317 /* No resume action for this thread. */
2324 /* Set *FLAG_P if this lwp has an interesting status pending. */
2326 resume_status_pending_p (struct inferior_list_entry
*entry
, void *flag_p
)
2328 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2330 /* LWPs which will not be resumed are not interesting, because
2331 we might not wait for them next time through linux_wait. */
2332 if (lwp
->resume
== NULL
)
2335 if (lwp
->status_pending_p
)
2336 * (int *) flag_p
= 1;
2341 /* Return 1 if this lwp that GDB wants running is stopped at an
2342 internal breakpoint that we need to step over. It assumes that any
2343 required STOP_PC adjustment has already been propagated to the
2344 inferior's regcache. */
2347 need_step_over_p (struct inferior_list_entry
*entry
, void *dummy
)
2349 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2350 struct thread_info
*saved_inferior
;
2353 /* LWPs which will not be resumed are not interesting, because we
2354 might not wait for them next time through linux_wait. */
2360 "Need step over [LWP %ld]? Ignoring, not stopped\n",
2365 if (lwp
->last_resume_kind
== resume_stop
)
2369 "Need step over [LWP %ld]? Ignoring, should remain stopped\n",
2374 if (!lwp
->need_step_over
)
2378 "Need step over [LWP %ld]? No\n", lwpid_of (lwp
));
2381 if (lwp
->status_pending_p
)
2385 "Need step over [LWP %ld]? Ignoring, has pending status.\n",
2390 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
2394 /* If the PC has changed since we stopped, then don't do anything,
2395 and let the breakpoint/tracepoint be hit. This happens if, for
2396 instance, GDB handled the decr_pc_after_break subtraction itself,
2397 GDB is OOL stepping this thread, or the user has issued a "jump"
2398 command, or poked thread's registers herself. */
2399 if (pc
!= lwp
->stop_pc
)
2403 "Need step over [LWP %ld]? Cancelling, PC was changed. "
2404 "Old stop_pc was 0x%s, PC is now 0x%s\n",
2405 lwpid_of (lwp
), paddress (lwp
->stop_pc
), paddress (pc
));
2407 lwp
->need_step_over
= 0;
2411 saved_inferior
= current_inferior
;
2412 current_inferior
= get_lwp_thread (lwp
);
2414 /* We can only step over breakpoints we know about. */
2415 if (breakpoint_here (pc
))
2417 /* Don't step over a breakpoint that GDB expects to hit
2419 if (gdb_breakpoint_here (pc
))
2423 "Need step over [LWP %ld]? yes, but found"
2424 " GDB breakpoint at 0x%s; skipping step over\n",
2425 lwpid_of (lwp
), paddress (pc
));
2427 current_inferior
= saved_inferior
;
2434 "Need step over [LWP %ld]? yes, found breakpoint at 0x%s\n",
2435 lwpid_of (lwp
), paddress (pc
));
2437 /* We've found an lwp that needs stepping over --- return 1 so
2438 that find_inferior stops looking. */
2439 current_inferior
= saved_inferior
;
2441 /* If the step over is cancelled, this is set again. */
2442 lwp
->need_step_over
= 0;
2447 current_inferior
= saved_inferior
;
2451 "Need step over [LWP %ld]? No, no breakpoint found at 0x%s\n",
2452 lwpid_of (lwp
), paddress (pc
));
2457 /* Start a step-over operation on LWP. When LWP stopped at a
2458 breakpoint, to make progress, we need to remove the breakpoint out
2459 of the way. If we let other threads run while we do that, they may
2460 pass by the breakpoint location and miss hitting it. To avoid
2461 that, a step-over momentarily stops all threads while LWP is
2462 single-stepped while the breakpoint is temporarily uninserted from
2463 the inferior. When the single-step finishes, we reinsert the
2464 breakpoint, and let all threads that are supposed to be running,
2467 On targets that don't support hardware single-step, we don't
2468 currently support full software single-stepping. Instead, we only
2469 support stepping over the thread event breakpoint, by asking the
2470 low target where to place a reinsert breakpoint. Since this
2471 routine assumes the breakpoint being stepped over is a thread event
2472 breakpoint, it usually assumes the return address of the current
2473 function is a good enough place to set the reinsert breakpoint. */
2476 start_step_over (struct lwp_info
*lwp
)
2478 struct thread_info
*saved_inferior
;
2484 "Starting step-over on LWP %ld. Stopping all threads\n",
2490 fprintf (stderr
, "Done stopping all threads for step-over.\n");
2492 /* Note, we should always reach here with an already adjusted PC,
2493 either by GDB (if we're resuming due to GDB's request), or by our
2494 caller, if we just finished handling an internal breakpoint GDB
2495 shouldn't care about. */
2498 saved_inferior
= current_inferior
;
2499 current_inferior
= get_lwp_thread (lwp
);
2501 lwp
->bp_reinsert
= pc
;
2502 uninsert_breakpoints_at (pc
);
2504 if (can_hardware_single_step ())
2510 CORE_ADDR raddr
= (*the_low_target
.breakpoint_reinsert_addr
) ();
2511 set_reinsert_breakpoint (raddr
);
2515 current_inferior
= saved_inferior
;
2517 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
2519 /* Require next event from this LWP. */
2520 step_over_bkpt
= lwp
->head
.id
;
2524 /* Finish a step-over. Reinsert the breakpoint we had uninserted in
2525 start_step_over, if still there, and delete any reinsert
2526 breakpoints we've set, on non hardware single-step targets. */
2529 finish_step_over (struct lwp_info
*lwp
)
2531 if (lwp
->bp_reinsert
!= 0)
2534 fprintf (stderr
, "Finished step over.\n");
2536 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
2537 may be no breakpoint to reinsert there by now. */
2538 reinsert_breakpoints_at (lwp
->bp_reinsert
);
2540 lwp
->bp_reinsert
= 0;
2542 /* Delete any software-single-step reinsert breakpoints. No
2543 longer needed. We don't have to worry about other threads
2544 hitting this trap, and later not being able to explain it,
2545 because we were stepping over a breakpoint, and we hold all
2546 threads but LWP stopped while doing that. */
2547 if (!can_hardware_single_step ())
2548 delete_reinsert_breakpoints ();
2550 step_over_bkpt
= null_ptid
;
2557 /* This function is called once per thread. We check the thread's resume
2558 request, which will tell us whether to resume, step, or leave the thread
2559 stopped; and what signal, if any, it should be sent.
2561 For threads which we aren't explicitly told otherwise, we preserve
2562 the stepping flag; this is used for stepping over gdbserver-placed
2565 If pending_flags was set in any thread, we queue any needed
2566 signals, since we won't actually resume. We already have a pending
2567 event to report, so we don't need to preserve any step requests;
2568 they should be re-issued if necessary. */
2571 linux_resume_one_thread (struct inferior_list_entry
*entry
, void *arg
)
2573 struct lwp_info
*lwp
;
2574 struct thread_info
*thread
;
2576 int leave_all_stopped
= * (int *) arg
;
2579 thread
= (struct thread_info
*) entry
;
2580 lwp
= get_thread_lwp (thread
);
2582 if (lwp
->resume
== NULL
)
2585 if (lwp
->resume
->kind
== resume_stop
)
2588 fprintf (stderr
, "resume_stop request for LWP %ld\n", lwpid_of (lwp
));
2593 fprintf (stderr
, "stopping LWP %ld\n", lwpid_of (lwp
));
2595 /* Stop the thread, and wait for the event asynchronously,
2596 through the event loop. */
2597 send_sigstop (&lwp
->head
);
2602 fprintf (stderr
, "already stopped LWP %ld\n",
2605 /* The LWP may have been stopped in an internal event that
2606 was not meant to be notified back to GDB (e.g., gdbserver
2607 breakpoint), so we should be reporting a stop event in
2610 /* If the thread already has a pending SIGSTOP, this is a
2611 no-op. Otherwise, something later will presumably resume
2612 the thread and this will cause it to cancel any pending
2613 operation, due to last_resume_kind == resume_stop. If
2614 the thread already has a pending status to report, we
2615 will still report it the next time we wait - see
2616 status_pending_p_callback. */
2617 send_sigstop (&lwp
->head
);
2620 /* For stop requests, we're done. */
2622 get_lwp_thread (lwp
)->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
2626 /* If this thread which is about to be resumed has a pending status,
2627 then don't resume any threads - we can just report the pending
2628 status. Make sure to queue any signals that would otherwise be
2629 sent. In all-stop mode, we do this decision based on if *any*
2630 thread has a pending status. If there's a thread that needs the
2631 step-over-breakpoint dance, then don't resume any other thread
2632 but that particular one. */
2633 leave_pending
= (lwp
->status_pending_p
|| leave_all_stopped
);
2638 fprintf (stderr
, "resuming LWP %ld\n", lwpid_of (lwp
));
2640 step
= (lwp
->resume
->kind
== resume_step
);
2641 linux_resume_one_lwp (lwp
, step
, lwp
->resume
->sig
, NULL
);
2642 get_lwp_thread (lwp
)->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
2647 fprintf (stderr
, "leaving LWP %ld stopped\n", lwpid_of (lwp
));
2649 /* If we have a new signal, enqueue the signal. */
2650 if (lwp
->resume
->sig
!= 0)
2652 struct pending_signals
*p_sig
;
2653 p_sig
= xmalloc (sizeof (*p_sig
));
2654 p_sig
->prev
= lwp
->pending_signals
;
2655 p_sig
->signal
= lwp
->resume
->sig
;
2656 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
2658 /* If this is the same signal we were previously stopped by,
2659 make sure to queue its siginfo. We can ignore the return
2660 value of ptrace; if it fails, we'll skip
2661 PTRACE_SETSIGINFO. */
2662 if (WIFSTOPPED (lwp
->last_status
)
2663 && WSTOPSIG (lwp
->last_status
) == lwp
->resume
->sig
)
2664 ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &p_sig
->info
);
2666 lwp
->pending_signals
= p_sig
;
2675 linux_resume (struct thread_resume
*resume_info
, size_t n
)
2677 struct thread_resume_array array
= { resume_info
, n
};
2678 struct lwp_info
*need_step_over
= NULL
;
2680 int leave_all_stopped
;
2682 find_inferior (&all_threads
, linux_set_resume_request
, &array
);
2684 /* If there is a thread which would otherwise be resumed, which has
2685 a pending status, then don't resume any threads - we can just
2686 report the pending status. Make sure to queue any signals that
2687 would otherwise be sent. In non-stop mode, we'll apply this
2688 logic to each thread individually. We consume all pending events
2689 before considering to start a step-over (in all-stop). */
2692 find_inferior (&all_lwps
, resume_status_pending_p
, &any_pending
);
2694 /* If there is a thread which would otherwise be resumed, which is
2695 stopped at a breakpoint that needs stepping over, then don't
2696 resume any threads - have it step over the breakpoint with all
2697 other threads stopped, then resume all threads again. Make sure
2698 to queue any signals that would otherwise be delivered or
2700 if (!any_pending
&& supports_breakpoints ())
2702 = (struct lwp_info
*) find_inferior (&all_lwps
,
2703 need_step_over_p
, NULL
);
2705 leave_all_stopped
= (need_step_over
!= NULL
|| any_pending
);
2709 if (need_step_over
!= NULL
)
2710 fprintf (stderr
, "Not resuming all, need step over\n");
2711 else if (any_pending
)
2713 "Not resuming, all-stop and found "
2714 "an LWP with pending status\n");
2716 fprintf (stderr
, "Resuming, no pending status or step over needed\n");
2719 /* Even if we're leaving threads stopped, queue all signals we'd
2720 otherwise deliver. */
2721 find_inferior (&all_threads
, linux_resume_one_thread
, &leave_all_stopped
);
2724 start_step_over (need_step_over
);
2727 /* This function is called once per thread. We check the thread's
2728 last resume request, which will tell us whether to resume, step, or
2729 leave the thread stopped. Any signal the client requested to be
2730 delivered has already been enqueued at this point.
2732 If any thread that GDB wants running is stopped at an internal
2733 breakpoint that needs stepping over, we start a step-over operation
2734 on that particular thread, and leave all others stopped. */
2737 proceed_one_lwp (struct inferior_list_entry
*entry
)
2739 struct lwp_info
*lwp
;
2742 lwp
= (struct lwp_info
*) entry
;
2746 "proceed_one_lwp: lwp %ld\n", lwpid_of (lwp
));
2751 fprintf (stderr
, " LWP %ld already running\n", lwpid_of (lwp
));
2755 if (lwp
->last_resume_kind
== resume_stop
)
2758 fprintf (stderr
, " client wants LWP %ld stopped\n", lwpid_of (lwp
));
2762 if (lwp
->status_pending_p
)
2765 fprintf (stderr
, " LWP %ld has pending status, leaving stopped\n",
2773 fprintf (stderr
, " LWP %ld is suspended\n", lwpid_of (lwp
));
2777 step
= lwp
->last_resume_kind
== resume_step
;
2778 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
2781 /* When we finish a step-over, set threads running again. If there's
2782 another thread that may need a step-over, now's the time to start
2783 it. Eventually, we'll move all threads past their breakpoints. */
2786 proceed_all_lwps (void)
2788 struct lwp_info
*need_step_over
;
2790 /* If there is a thread which would otherwise be resumed, which is
2791 stopped at a breakpoint that needs stepping over, then don't
2792 resume any threads - have it step over the breakpoint with all
2793 other threads stopped, then resume all threads again. */
2795 if (supports_breakpoints ())
2798 = (struct lwp_info
*) find_inferior (&all_lwps
,
2799 need_step_over_p
, NULL
);
2801 if (need_step_over
!= NULL
)
2804 fprintf (stderr
, "proceed_all_lwps: found "
2805 "thread %ld needing a step-over\n",
2806 lwpid_of (need_step_over
));
2808 start_step_over (need_step_over
);
2814 fprintf (stderr
, "Proceeding, no step-over needed\n");
2816 for_each_inferior (&all_lwps
, proceed_one_lwp
);
2819 /* Stopped LWPs that the client wanted to be running, that don't have
2820 pending statuses, are set to run again, except for EXCEPT, if not
2821 NULL. This undoes a stop_all_lwps call. */
2824 unstop_all_lwps (struct lwp_info
*except
)
2830 "unstopping all lwps, except=(LWP %ld)\n", lwpid_of (except
));
2833 "unstopping all lwps\n");
2836 /* Make sure proceed_one_lwp doesn't try to resume this thread. */
2838 ++except
->suspended
;
2840 for_each_inferior (&all_lwps
, proceed_one_lwp
);
2843 --except
->suspended
;
2846 #ifdef HAVE_LINUX_USRREGS
2849 register_addr (int regnum
)
2853 if (regnum
< 0 || regnum
>= the_low_target
.num_regs
)
2854 error ("Invalid register number %d.", regnum
);
2856 addr
= the_low_target
.regmap
[regnum
];
2861 /* Fetch one register. */
2863 fetch_register (struct regcache
*regcache
, int regno
)
2870 if (regno
>= the_low_target
.num_regs
)
2872 if ((*the_low_target
.cannot_fetch_register
) (regno
))
2875 regaddr
= register_addr (regno
);
2879 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2880 size
= ((register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
2881 & - sizeof (PTRACE_XFER_TYPE
));
2882 buf
= alloca (size
);
2883 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
2886 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
2887 ptrace (PTRACE_PEEKUSER
, pid
,
2888 /* Coerce to a uintptr_t first to avoid potential gcc warning
2889 of coercing an 8 byte integer to a 4 byte pointer. */
2890 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
, 0);
2891 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
2893 error ("reading register %d: %s", regno
, strerror (errno
));
2896 if (the_low_target
.supply_ptrace_register
)
2897 the_low_target
.supply_ptrace_register (regcache
, regno
, buf
);
2899 supply_register (regcache
, regno
, buf
);
2902 /* Fetch all registers, or just one, from the child process. */
2904 usr_fetch_inferior_registers (struct regcache
*regcache
, int regno
)
2907 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
2908 fetch_register (regcache
, regno
);
2910 fetch_register (regcache
, regno
);
2913 /* Store our register values back into the inferior.
2914 If REGNO is -1, do this for all registers.
2915 Otherwise, REGNO specifies which register (so we can save time). */
2917 usr_store_inferior_registers (struct regcache
*regcache
, int regno
)
2926 if (regno
>= the_low_target
.num_regs
)
2929 if ((*the_low_target
.cannot_store_register
) (regno
) == 1)
2932 regaddr
= register_addr (regno
);
2936 size
= (register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
2937 & - sizeof (PTRACE_XFER_TYPE
);
2938 buf
= alloca (size
);
2939 memset (buf
, 0, size
);
2941 if (the_low_target
.collect_ptrace_register
)
2942 the_low_target
.collect_ptrace_register (regcache
, regno
, buf
);
2944 collect_register (regcache
, regno
, buf
);
2946 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2947 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
2950 ptrace (PTRACE_POKEUSER
, pid
,
2951 /* Coerce to a uintptr_t first to avoid potential gcc warning
2952 about coercing an 8 byte integer to a 4 byte pointer. */
2953 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
,
2954 (PTRACE_ARG4_TYPE
) *(PTRACE_XFER_TYPE
*) (buf
+ i
));
2957 /* At this point, ESRCH should mean the process is
2958 already gone, in which case we simply ignore attempts
2959 to change its registers. See also the related
2960 comment in linux_resume_one_lwp. */
2964 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
2965 error ("writing register %d: %s", regno
, strerror (errno
));
2967 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
2971 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
2972 usr_store_inferior_registers (regcache
, regno
);
2974 #endif /* HAVE_LINUX_USRREGS */
2978 #ifdef HAVE_LINUX_REGSETS
2981 regsets_fetch_inferior_registers (struct regcache
*regcache
)
2983 struct regset_info
*regset
;
2984 int saw_general_regs
= 0;
2987 regset
= target_regsets
;
2989 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2990 while (regset
->size
>= 0)
2995 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
3001 buf
= xmalloc (regset
->size
);
3003 res
= ptrace (regset
->get_request
, pid
, 0, buf
);
3005 res
= ptrace (regset
->get_request
, pid
, buf
, 0);
3011 /* If we get EIO on a regset, do not try it again for
3013 disabled_regsets
[regset
- target_regsets
] = 1;
3020 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%d",
3025 else if (regset
->type
== GENERAL_REGS
)
3026 saw_general_regs
= 1;
3027 regset
->store_function (regcache
, buf
);
3031 if (saw_general_regs
)
3038 regsets_store_inferior_registers (struct regcache
*regcache
)
3040 struct regset_info
*regset
;
3041 int saw_general_regs
= 0;
3044 regset
= target_regsets
;
3046 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3047 while (regset
->size
>= 0)
3052 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
3058 buf
= xmalloc (regset
->size
);
3060 /* First fill the buffer with the current register set contents,
3061 in case there are any items in the kernel's regset that are
3062 not in gdbserver's regcache. */
3064 res
= ptrace (regset
->get_request
, pid
, 0, buf
);
3066 res
= ptrace (regset
->get_request
, pid
, buf
, 0);
3071 /* Then overlay our cached registers on that. */
3072 regset
->fill_function (regcache
, buf
);
3074 /* Only now do we write the register set. */
3076 res
= ptrace (regset
->set_request
, pid
, 0, buf
);
3078 res
= ptrace (regset
->set_request
, pid
, buf
, 0);
3086 /* If we get EIO on a regset, do not try it again for
3088 disabled_regsets
[regset
- target_regsets
] = 1;
3092 else if (errno
== ESRCH
)
3094 /* At this point, ESRCH should mean the process is
3095 already gone, in which case we simply ignore attempts
3096 to change its registers. See also the related
3097 comment in linux_resume_one_lwp. */
3103 perror ("Warning: ptrace(regsets_store_inferior_registers)");
3106 else if (regset
->type
== GENERAL_REGS
)
3107 saw_general_regs
= 1;
3111 if (saw_general_regs
)
3118 #endif /* HAVE_LINUX_REGSETS */
3122 linux_fetch_registers (struct regcache
*regcache
, int regno
)
3124 #ifdef HAVE_LINUX_REGSETS
3125 if (regsets_fetch_inferior_registers (regcache
) == 0)
3128 #ifdef HAVE_LINUX_USRREGS
3129 usr_fetch_inferior_registers (regcache
, regno
);
3134 linux_store_registers (struct regcache
*regcache
, int regno
)
3136 #ifdef HAVE_LINUX_REGSETS
3137 if (regsets_store_inferior_registers (regcache
) == 0)
3140 #ifdef HAVE_LINUX_USRREGS
3141 usr_store_inferior_registers (regcache
, regno
);
3146 /* Copy LEN bytes from inferior's memory starting at MEMADDR
3147 to debugger memory starting at MYADDR. */
3150 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
3153 /* Round starting address down to longword boundary. */
3154 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
3155 /* Round ending address up; get number of longwords that makes. */
3157 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
3158 / sizeof (PTRACE_XFER_TYPE
);
3159 /* Allocate buffer of that many longwords. */
3160 register PTRACE_XFER_TYPE
*buffer
3161 = (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
3164 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3166 /* Try using /proc. Don't bother for one word. */
3167 if (len
>= 3 * sizeof (long))
3169 /* We could keep this file open and cache it - possibly one per
3170 thread. That requires some juggling, but is even faster. */
3171 sprintf (filename
, "/proc/%d/mem", pid
);
3172 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
3176 /* If pread64 is available, use it. It's faster if the kernel
3177 supports it (only one syscall), and it's 64-bit safe even on
3178 32-bit platforms (for instance, SPARC debugging a SPARC64
3181 if (pread64 (fd
, myaddr
, len
, memaddr
) != len
)
3183 if (lseek (fd
, memaddr
, SEEK_SET
) == -1 || read (fd
, myaddr
, len
) != len
)
3195 /* Read all the longwords */
3196 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
3199 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
3200 about coercing an 8 byte integer to a 4 byte pointer. */
3201 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, pid
,
3202 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
3207 /* Copy appropriate bytes out of the buffer. */
3209 (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
3215 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
3216 memory at MEMADDR. On failure (cannot write to the inferior)
3217 returns the value of errno. */
3220 linux_write_memory (CORE_ADDR memaddr
, const unsigned char *myaddr
, int len
)
3223 /* Round starting address down to longword boundary. */
3224 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
3225 /* Round ending address up; get number of longwords that makes. */
3227 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1) / sizeof (PTRACE_XFER_TYPE
);
3228 /* Allocate buffer of that many longwords. */
3229 register PTRACE_XFER_TYPE
*buffer
= (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
3230 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3234 /* Dump up to four bytes. */
3235 unsigned int val
= * (unsigned int *) myaddr
;
3241 val
= val
& 0xffffff;
3242 fprintf (stderr
, "Writing %0*x to 0x%08lx\n", 2 * ((len
< 4) ? len
: 4),
3243 val
, (long)memaddr
);
3246 /* Fill start and end extra bytes of buffer with existing memory data. */
3249 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
3250 about coercing an 8 byte integer to a 4 byte pointer. */
3251 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, pid
,
3252 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
3260 = ptrace (PTRACE_PEEKTEXT
, pid
,
3261 /* Coerce to a uintptr_t first to avoid potential gcc warning
3262 about coercing an 8 byte integer to a 4 byte pointer. */
3263 (PTRACE_ARG3_TYPE
) (uintptr_t) (addr
+ (count
- 1)
3264 * sizeof (PTRACE_XFER_TYPE
)),
3270 /* Copy data to be written over corresponding part of buffer. */
3272 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)), myaddr
, len
);
3274 /* Write the entire buffer. */
3276 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
3279 ptrace (PTRACE_POKETEXT
, pid
,
3280 /* Coerce to a uintptr_t first to avoid potential gcc warning
3281 about coercing an 8 byte integer to a 4 byte pointer. */
3282 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
,
3283 (PTRACE_ARG4_TYPE
) buffer
[i
]);
3291 /* Non-zero if the kernel supports PTRACE_O_TRACEFORK. */
3292 static int linux_supports_tracefork_flag
;
3294 /* Helper functions for linux_test_for_tracefork, called via clone (). */
3297 linux_tracefork_grandchild (void *arg
)
3302 #define STACK_SIZE 4096
3305 linux_tracefork_child (void *arg
)
3307 ptrace (PTRACE_TRACEME
, 0, 0, 0);
3308 kill (getpid (), SIGSTOP
);
3310 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
3313 linux_tracefork_grandchild (NULL
);
3315 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3318 __clone2 (linux_tracefork_grandchild
, arg
, STACK_SIZE
,
3319 CLONE_VM
| SIGCHLD
, NULL
);
3321 clone (linux_tracefork_grandchild
, arg
+ STACK_SIZE
,
3322 CLONE_VM
| SIGCHLD
, NULL
);
3325 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3330 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
3331 sure that we can enable the option, and that it had the desired
3335 linux_test_for_tracefork (void)
3337 int child_pid
, ret
, status
;
3339 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
3340 char *stack
= xmalloc (STACK_SIZE
* 4);
3341 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3343 linux_supports_tracefork_flag
= 0;
3345 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
3347 child_pid
= fork ();
3349 linux_tracefork_child (NULL
);
3351 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3353 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
3355 child_pid
= __clone2 (linux_tracefork_child
, stack
, STACK_SIZE
,
3356 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
3357 #else /* !__ia64__ */
3358 child_pid
= clone (linux_tracefork_child
, stack
+ STACK_SIZE
,
3359 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
3360 #endif /* !__ia64__ */
3362 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3364 if (child_pid
== -1)
3365 perror_with_name ("clone");
3367 ret
= my_waitpid (child_pid
, &status
, 0);
3369 perror_with_name ("waitpid");
3370 else if (ret
!= child_pid
)
3371 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret
);
3372 if (! WIFSTOPPED (status
))
3373 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status
);
3375 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0,
3376 (PTRACE_ARG4_TYPE
) PTRACE_O_TRACEFORK
);
3379 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
3382 warning ("linux_test_for_tracefork: failed to kill child");
3386 ret
= my_waitpid (child_pid
, &status
, 0);
3387 if (ret
!= child_pid
)
3388 warning ("linux_test_for_tracefork: failed to wait for killed child");
3389 else if (!WIFSIGNALED (status
))
3390 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
3391 "killed child", status
);
3396 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
3398 warning ("linux_test_for_tracefork: failed to resume child");
3400 ret
= my_waitpid (child_pid
, &status
, 0);
3402 if (ret
== child_pid
&& WIFSTOPPED (status
)
3403 && status
>> 16 == PTRACE_EVENT_FORK
)
3406 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
3407 if (ret
== 0 && second_pid
!= 0)
3411 linux_supports_tracefork_flag
= 1;
3412 my_waitpid (second_pid
, &second_status
, 0);
3413 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
3415 warning ("linux_test_for_tracefork: failed to kill second child");
3416 my_waitpid (second_pid
, &status
, 0);
3420 warning ("linux_test_for_tracefork: unexpected result from waitpid "
3421 "(%d, status 0x%x)", ret
, status
);
3425 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
3427 warning ("linux_test_for_tracefork: failed to kill child");
3428 my_waitpid (child_pid
, &status
, 0);
3430 while (WIFSTOPPED (status
));
3432 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
3434 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3439 linux_look_up_symbols (void)
3441 #ifdef USE_THREAD_DB
3442 struct process_info
*proc
= current_process ();
3444 if (proc
->private->thread_db
!= NULL
)
3447 /* If the kernel supports tracing forks then it also supports tracing
3448 clones, and then we don't need to use the magic thread event breakpoint
3449 to learn about threads. */
3450 thread_db_init (!linux_supports_tracefork_flag
);
3455 linux_request_interrupt (void)
3457 extern unsigned long signal_pid
;
3459 if (!ptid_equal (cont_thread
, null_ptid
)
3460 && !ptid_equal (cont_thread
, minus_one_ptid
))
3462 struct lwp_info
*lwp
;
3465 lwp
= get_thread_lwp (current_inferior
);
3466 lwpid
= lwpid_of (lwp
);
3467 kill_lwp (lwpid
, SIGINT
);
3470 kill_lwp (signal_pid
, SIGINT
);
3473 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
3474 to debugger memory starting at MYADDR. */
3477 linux_read_auxv (CORE_ADDR offset
, unsigned char *myaddr
, unsigned int len
)
3479 char filename
[PATH_MAX
];
3481 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3483 snprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
3485 fd
= open (filename
, O_RDONLY
);
3489 if (offset
!= (CORE_ADDR
) 0
3490 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
3493 n
= read (fd
, myaddr
, len
);
3500 /* These breakpoint and watchpoint related wrapper functions simply
3501 pass on the function call if the target has registered a
3502 corresponding function. */
3505 linux_insert_point (char type
, CORE_ADDR addr
, int len
)
3507 if (the_low_target
.insert_point
!= NULL
)
3508 return the_low_target
.insert_point (type
, addr
, len
);
3510 /* Unsupported (see target.h). */
3515 linux_remove_point (char type
, CORE_ADDR addr
, int len
)
3517 if (the_low_target
.remove_point
!= NULL
)
3518 return the_low_target
.remove_point (type
, addr
, len
);
3520 /* Unsupported (see target.h). */
3525 linux_stopped_by_watchpoint (void)
3527 struct lwp_info
*lwp
= get_thread_lwp (current_inferior
);
3529 return lwp
->stopped_by_watchpoint
;
3533 linux_stopped_data_address (void)
3535 struct lwp_info
*lwp
= get_thread_lwp (current_inferior
);
3537 return lwp
->stopped_data_address
;
3540 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
3541 #if defined(__mcoldfire__)
3542 /* These should really be defined in the kernel's ptrace.h header. */
3543 #define PT_TEXT_ADDR 49*4
3544 #define PT_DATA_ADDR 50*4
3545 #define PT_TEXT_END_ADDR 51*4
3548 /* Under uClinux, programs are loaded at non-zero offsets, which we need
3549 to tell gdb about. */
3552 linux_read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
3554 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
3555 unsigned long text
, text_end
, data
;
3556 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3560 text
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_ADDR
, 0);
3561 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_END_ADDR
, 0);
3562 data
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_DATA_ADDR
, 0);
3566 /* Both text and data offsets produced at compile-time (and so
3567 used by gdb) are relative to the beginning of the program,
3568 with the data segment immediately following the text segment.
3569 However, the actual runtime layout in memory may put the data
3570 somewhere else, so when we send gdb a data base-address, we
3571 use the real data base address and subtract the compile-time
3572 data base-address from it (which is just the length of the
3573 text segment). BSS immediately follows data in both
3576 *data_p
= data
- (text_end
- text
);
3586 compare_ints (const void *xa
, const void *xb
)
3588 int a
= *(const int *)xa
;
3589 int b
= *(const int *)xb
;
3595 unique (int *b
, int *e
)
3604 /* Given PID, iterates over all threads in that process.
3606 Information about each thread, in a format suitable for qXfer:osdata:thread
3607 is printed to BUFFER, if it's not NULL. BUFFER is assumed to be already
3608 initialized, and the caller is responsible for finishing and appending '\0'
3611 The list of cores that threads are running on is assigned to *CORES, if it
3612 is not NULL. If no cores are found, *CORES will be set to NULL. Caller
3613 should free *CORES. */
3616 list_threads (int pid
, struct buffer
*buffer
, char **cores
)
3620 int *core_numbers
= xmalloc (sizeof (int) * allocated
);
3624 struct stat statbuf
;
3626 sprintf (pathname
, "/proc/%d/task", pid
);
3627 if (stat (pathname
, &statbuf
) == 0 && S_ISDIR (statbuf
.st_mode
))
3629 dir
= opendir (pathname
);
3632 free (core_numbers
);
3636 while ((dp
= readdir (dir
)) != NULL
)
3638 unsigned long lwp
= strtoul (dp
->d_name
, NULL
, 10);
3642 unsigned core
= linux_core_of_thread (ptid_build (pid
, lwp
, 0));
3646 char s
[sizeof ("4294967295")];
3647 sprintf (s
, "%u", core
);
3649 if (count
== allocated
)
3652 core_numbers
= realloc (core_numbers
,
3653 sizeof (int) * allocated
);
3655 core_numbers
[count
++] = core
;
3657 buffer_xml_printf (buffer
,
3659 "<column name=\"pid\">%d</column>"
3660 "<column name=\"tid\">%s</column>"
3661 "<column name=\"core\">%s</column>"
3662 "</item>", pid
, dp
->d_name
, s
);
3667 buffer_xml_printf (buffer
,
3669 "<column name=\"pid\">%d</column>"
3670 "<column name=\"tid\">%s</column>"
3671 "</item>", pid
, dp
->d_name
);
3682 struct buffer buffer2
;
3685 qsort (core_numbers
, count
, sizeof (int), compare_ints
);
3687 /* Remove duplicates. */
3689 e
= unique (b
, core_numbers
+ count
);
3691 buffer_init (&buffer2
);
3693 for (b
= core_numbers
; b
!= e
; ++b
)
3695 char number
[sizeof ("4294967295")];
3696 sprintf (number
, "%u", *b
);
3697 buffer_xml_printf (&buffer2
, "%s%s",
3698 (b
== core_numbers
) ? "" : ",", number
);
3700 buffer_grow_str0 (&buffer2
, "");
3702 *cores
= buffer_finish (&buffer2
);
3705 free (core_numbers
);
3709 show_process (int pid
, const char *username
, struct buffer
*buffer
)
3713 char cmd
[MAXPATHLEN
+ 1];
3715 sprintf (pathname
, "/proc/%d/cmdline", pid
);
3717 if ((f
= fopen (pathname
, "r")) != NULL
)
3719 size_t len
= fread (cmd
, 1, sizeof (cmd
) - 1, f
);
3724 for (i
= 0; i
< len
; i
++)
3729 buffer_xml_printf (buffer
,
3731 "<column name=\"pid\">%d</column>"
3732 "<column name=\"user\">%s</column>"
3733 "<column name=\"command\">%s</column>",
3738 /* This only collects core numbers, and does not print threads. */
3739 list_threads (pid
, NULL
, &cores
);
3743 buffer_xml_printf (buffer
,
3744 "<column name=\"cores\">%s</column>", cores
);
3748 buffer_xml_printf (buffer
, "</item>");
3755 linux_qxfer_osdata (const char *annex
,
3756 unsigned char *readbuf
, unsigned const char *writebuf
,
3757 CORE_ADDR offset
, int len
)
3759 /* We make the process list snapshot when the object starts to be
3761 static const char *buf
;
3762 static long len_avail
= -1;
3763 static struct buffer buffer
;
3769 if (strcmp (annex
, "processes") == 0)
3771 else if (strcmp (annex
, "threads") == 0)
3776 if (!readbuf
|| writebuf
)
3781 if (len_avail
!= -1 && len_avail
!= 0)
3782 buffer_free (&buffer
);
3785 buffer_init (&buffer
);
3787 buffer_grow_str (&buffer
, "<osdata type=\"processes\">");
3789 buffer_grow_str (&buffer
, "<osdata type=\"threads\">");
3791 dirp
= opendir ("/proc");
3795 while ((dp
= readdir (dirp
)) != NULL
)
3797 struct stat statbuf
;
3798 char procentry
[sizeof ("/proc/4294967295")];
3800 if (!isdigit (dp
->d_name
[0])
3801 || strlen (dp
->d_name
) > sizeof ("4294967295") - 1)
3804 sprintf (procentry
, "/proc/%s", dp
->d_name
);
3805 if (stat (procentry
, &statbuf
) == 0
3806 && S_ISDIR (statbuf
.st_mode
))
3808 int pid
= (int) strtoul (dp
->d_name
, NULL
, 10);
3812 struct passwd
*entry
= getpwuid (statbuf
.st_uid
);
3813 show_process (pid
, entry
? entry
->pw_name
: "?", &buffer
);
3817 list_threads (pid
, &buffer
, NULL
);
3824 buffer_grow_str0 (&buffer
, "</osdata>\n");
3825 buf
= buffer_finish (&buffer
);
3826 len_avail
= strlen (buf
);
3829 if (offset
>= len_avail
)
3831 /* Done. Get rid of the data. */
3832 buffer_free (&buffer
);
3838 if (len
> len_avail
- offset
)
3839 len
= len_avail
- offset
;
3840 memcpy (readbuf
, buf
+ offset
, len
);
3845 /* Convert a native/host siginfo object, into/from the siginfo in the
3846 layout of the inferiors' architecture. */
3849 siginfo_fixup (struct siginfo
*siginfo
, void *inf_siginfo
, int direction
)
3853 if (the_low_target
.siginfo_fixup
!= NULL
)
3854 done
= the_low_target
.siginfo_fixup (siginfo
, inf_siginfo
, direction
);
3856 /* If there was no callback, or the callback didn't do anything,
3857 then just do a straight memcpy. */
3861 memcpy (siginfo
, inf_siginfo
, sizeof (struct siginfo
));
3863 memcpy (inf_siginfo
, siginfo
, sizeof (struct siginfo
));
3868 linux_xfer_siginfo (const char *annex
, unsigned char *readbuf
,
3869 unsigned const char *writebuf
, CORE_ADDR offset
, int len
)
3872 struct siginfo siginfo
;
3873 char inf_siginfo
[sizeof (struct siginfo
)];
3875 if (current_inferior
== NULL
)
3878 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3881 fprintf (stderr
, "%s siginfo for lwp %d.\n",
3882 readbuf
!= NULL
? "Reading" : "Writing",
3885 if (offset
> sizeof (siginfo
))
3888 if (ptrace (PTRACE_GETSIGINFO
, pid
, 0, &siginfo
) != 0)
3891 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
3892 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3893 inferior with a 64-bit GDBSERVER should look the same as debugging it
3894 with a 32-bit GDBSERVER, we need to convert it. */
3895 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
3897 if (offset
+ len
> sizeof (siginfo
))
3898 len
= sizeof (siginfo
) - offset
;
3900 if (readbuf
!= NULL
)
3901 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
3904 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
3906 /* Convert back to ptrace layout before flushing it out. */
3907 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
3909 if (ptrace (PTRACE_SETSIGINFO
, pid
, 0, &siginfo
) != 0)
3916 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
3917 so we notice when children change state; as the handler for the
3918 sigsuspend in my_waitpid. */
3921 sigchld_handler (int signo
)
3923 int old_errno
= errno
;
3926 /* fprintf is not async-signal-safe, so call write directly. */
3927 write (2, "sigchld_handler\n", sizeof ("sigchld_handler\n") - 1);
3929 if (target_is_async_p ())
3930 async_file_mark (); /* trigger a linux_wait */
3936 linux_supports_non_stop (void)
3942 linux_async (int enable
)
3944 int previous
= (linux_event_pipe
[0] != -1);
3946 if (previous
!= enable
)
3949 sigemptyset (&mask
);
3950 sigaddset (&mask
, SIGCHLD
);
3952 sigprocmask (SIG_BLOCK
, &mask
, NULL
);
3956 if (pipe (linux_event_pipe
) == -1)
3957 fatal ("creating event pipe failed.");
3959 fcntl (linux_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
3960 fcntl (linux_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
3962 /* Register the event loop handler. */
3963 add_file_handler (linux_event_pipe
[0],
3964 handle_target_event
, NULL
);
3966 /* Always trigger a linux_wait. */
3971 delete_file_handler (linux_event_pipe
[0]);
3973 close (linux_event_pipe
[0]);
3974 close (linux_event_pipe
[1]);
3975 linux_event_pipe
[0] = -1;
3976 linux_event_pipe
[1] = -1;
3979 sigprocmask (SIG_UNBLOCK
, &mask
, NULL
);
3986 linux_start_non_stop (int nonstop
)
3988 /* Register or unregister from event-loop accordingly. */
3989 linux_async (nonstop
);
3994 linux_supports_multi_process (void)
4000 /* Enumerate spufs IDs for process PID. */
4002 spu_enumerate_spu_ids (long pid
, unsigned char *buf
, CORE_ADDR offset
, int len
)
4008 struct dirent
*entry
;
4010 sprintf (path
, "/proc/%ld/fd", pid
);
4011 dir
= opendir (path
);
4016 while ((entry
= readdir (dir
)) != NULL
)
4022 fd
= atoi (entry
->d_name
);
4026 sprintf (path
, "/proc/%ld/fd/%d", pid
, fd
);
4027 if (stat (path
, &st
) != 0)
4029 if (!S_ISDIR (st
.st_mode
))
4032 if (statfs (path
, &stfs
) != 0)
4034 if (stfs
.f_type
!= SPUFS_MAGIC
)
4037 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4039 *(unsigned int *)(buf
+ pos
- offset
) = fd
;
4049 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
4050 object type, using the /proc file system. */
4052 linux_qxfer_spu (const char *annex
, unsigned char *readbuf
,
4053 unsigned const char *writebuf
,
4054 CORE_ADDR offset
, int len
)
4056 long pid
= lwpid_of (get_thread_lwp (current_inferior
));
4061 if (!writebuf
&& !readbuf
)
4069 return spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4072 sprintf (buf
, "/proc/%ld/fd/%s", pid
, annex
);
4073 fd
= open (buf
, writebuf
? O_WRONLY
: O_RDONLY
);
4078 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4085 ret
= write (fd
, writebuf
, (size_t) len
);
4087 ret
= read (fd
, readbuf
, (size_t) len
);
4094 linux_core_of_thread (ptid_t ptid
)
4096 char filename
[sizeof ("/proc//task//stat")
4097 + 2 * 20 /* decimal digits for 2 numbers, max 2^64 bit each */
4100 char *content
= NULL
;
4103 int content_read
= 0;
4107 sprintf (filename
, "/proc/%d/task/%ld/stat",
4108 ptid_get_pid (ptid
), ptid_get_lwp (ptid
));
4109 f
= fopen (filename
, "r");
4116 content
= realloc (content
, content_read
+ 1024);
4117 n
= fread (content
+ content_read
, 1, 1024, f
);
4121 content
[content_read
] = '\0';
4126 p
= strchr (content
, '(');
4127 p
= strchr (p
, ')') + 2; /* skip ")" and a whitespace. */
4129 p
= strtok_r (p
, " ", &ts
);
4130 for (i
= 0; i
!= 36; ++i
)
4131 p
= strtok_r (NULL
, " ", &ts
);
4133 if (sscanf (p
, "%d", &core
) == 0)
4142 static struct target_ops linux_target_ops
= {
4143 linux_create_inferior
,
4151 linux_fetch_registers
,
4152 linux_store_registers
,
4155 linux_look_up_symbols
,
4156 linux_request_interrupt
,
4160 linux_stopped_by_watchpoint
,
4161 linux_stopped_data_address
,
4162 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4167 #ifdef USE_THREAD_DB
4168 thread_db_get_tls_address
,
4173 hostio_last_error_from_errno
,
4176 linux_supports_non_stop
,
4178 linux_start_non_stop
,
4179 linux_supports_multi_process
,
4180 #ifdef USE_THREAD_DB
4181 thread_db_handle_monitor_command
,
4185 linux_core_of_thread
4189 linux_init_signals ()
4191 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
4192 to find what the cancel signal actually is. */
4193 #ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
4194 signal (__SIGRTMIN
+1, SIG_IGN
);
4199 initialize_low (void)
4201 struct sigaction sigchld_action
;
4202 memset (&sigchld_action
, 0, sizeof (sigchld_action
));
4203 set_target_ops (&linux_target_ops
);
4204 set_breakpoint_data (the_low_target
.breakpoint
,
4205 the_low_target
.breakpoint_len
);
4206 linux_init_signals ();
4207 linux_test_for_tracefork ();
4208 #ifdef HAVE_LINUX_REGSETS
4209 for (num_regsets
= 0; target_regsets
[num_regsets
].size
>= 0; num_regsets
++)
4211 disabled_regsets
= xmalloc (num_regsets
);
4214 sigchld_action
.sa_handler
= sigchld_handler
;
4215 sigemptyset (&sigchld_action
.sa_mask
);
4216 sigchld_action
.sa_flags
= SA_RESTART
;
4217 sigaction (SIGCHLD
, &sigchld_action
, NULL
);