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>
44 /* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h
45 then ELFMAG0 will have been defined. If it didn't get included by
46 gdb_proc_service.h then including it will likely introduce a duplicate
47 definition of elf_fpregset_t. */
52 #define SPUFS_MAGIC 0x23c9b64e
55 #ifndef PTRACE_GETSIGINFO
56 # define PTRACE_GETSIGINFO 0x4202
57 # define PTRACE_SETSIGINFO 0x4203
64 /* If the system headers did not provide the constants, hard-code the normal
66 #ifndef PTRACE_EVENT_FORK
68 #define PTRACE_SETOPTIONS 0x4200
69 #define PTRACE_GETEVENTMSG 0x4201
71 /* options set using PTRACE_SETOPTIONS */
72 #define PTRACE_O_TRACESYSGOOD 0x00000001
73 #define PTRACE_O_TRACEFORK 0x00000002
74 #define PTRACE_O_TRACEVFORK 0x00000004
75 #define PTRACE_O_TRACECLONE 0x00000008
76 #define PTRACE_O_TRACEEXEC 0x00000010
77 #define PTRACE_O_TRACEVFORKDONE 0x00000020
78 #define PTRACE_O_TRACEEXIT 0x00000040
80 /* Wait extended result codes for the above trace options. */
81 #define PTRACE_EVENT_FORK 1
82 #define PTRACE_EVENT_VFORK 2
83 #define PTRACE_EVENT_CLONE 3
84 #define PTRACE_EVENT_EXEC 4
85 #define PTRACE_EVENT_VFORK_DONE 5
86 #define PTRACE_EVENT_EXIT 6
88 #endif /* PTRACE_EVENT_FORK */
90 /* We can't always assume that this flag is available, but all systems
91 with the ptrace event handlers also have __WALL, so it's safe to use
94 #define __WALL 0x40000000 /* Wait for any child. */
98 #define W_STOPCODE(sig) ((sig) << 8 | 0x7f)
102 #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
107 /* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
108 representation of the thread ID.
110 ``all_lwps'' is keyed by the process ID - which on Linux is (presently)
111 the same as the LWP ID.
113 ``all_processes'' is keyed by the "overall process ID", which
114 GNU/Linux calls tgid, "thread group ID". */
116 struct inferior_list all_lwps
;
118 /* A list of all unknown processes which receive stop signals. Some other
119 process will presumably claim each of these as forked children
122 struct inferior_list stopped_pids
;
124 /* FIXME this is a bit of a hack, and could be removed. */
125 int stopping_threads
;
127 /* FIXME make into a target method? */
128 int using_threads
= 1;
130 /* True if we're presently stabilizing threads (moving them out of
132 static int stabilizing_threads
;
134 /* This flag is true iff we've just created or attached to our first
135 inferior but it has not stopped yet. As soon as it does, we need
136 to call the low target's arch_setup callback. Doing this only on
137 the first inferior avoids reinializing the architecture on every
138 inferior, and avoids messing with the register caches of the
139 already running inferiors. NOTE: this assumes all inferiors under
140 control of gdbserver have the same architecture. */
141 static int new_inferior
;
143 static void linux_resume_one_lwp (struct lwp_info
*lwp
,
144 int step
, int signal
, siginfo_t
*info
);
145 static void linux_resume (struct thread_resume
*resume_info
, size_t n
);
146 static void stop_all_lwps (int suspend
, struct lwp_info
*except
);
147 static void unstop_all_lwps (int unsuspend
, struct lwp_info
*except
);
148 static int linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
);
149 static void *add_lwp (ptid_t ptid
);
150 static int linux_stopped_by_watchpoint (void);
151 static void mark_lwp_dead (struct lwp_info
*lwp
, int wstat
);
152 static int linux_core_of_thread (ptid_t ptid
);
153 static void proceed_all_lwps (void);
154 static int finish_step_over (struct lwp_info
*lwp
);
155 static CORE_ADDR
get_stop_pc (struct lwp_info
*lwp
);
156 static int kill_lwp (unsigned long lwpid
, int signo
);
157 static void linux_enable_event_reporting (int pid
);
159 /* True if the low target can hardware single-step. Such targets
160 don't need a BREAKPOINT_REINSERT_ADDR callback. */
163 can_hardware_single_step (void)
165 return (the_low_target
.breakpoint_reinsert_addr
== NULL
);
168 /* True if the low target supports memory breakpoints. If so, we'll
169 have a GET_PC implementation. */
172 supports_breakpoints (void)
174 return (the_low_target
.get_pc
!= NULL
);
177 /* Returns true if this target can support fast tracepoints. This
178 does not mean that the in-process agent has been loaded in the
182 supports_fast_tracepoints (void)
184 return the_low_target
.install_fast_tracepoint_jump_pad
!= NULL
;
187 struct pending_signals
191 struct pending_signals
*prev
;
194 #define PTRACE_ARG3_TYPE void *
195 #define PTRACE_ARG4_TYPE void *
196 #define PTRACE_XFER_TYPE long
198 #ifdef HAVE_LINUX_REGSETS
199 static char *disabled_regsets
;
200 static int num_regsets
;
203 /* The read/write ends of the pipe registered as waitable file in the
205 static int linux_event_pipe
[2] = { -1, -1 };
207 /* True if we're currently in async mode. */
208 #define target_is_async_p() (linux_event_pipe[0] != -1)
210 static void send_sigstop (struct lwp_info
*lwp
);
211 static void wait_for_sigstop (struct inferior_list_entry
*entry
);
213 /* Accepts an integer PID; Returns a string representing a file that
214 can be opened to get info for the child process.
215 Space for the result is malloc'd, caller must free. */
218 linux_child_pid_to_exec_file (int pid
)
222 name1
= xmalloc (MAXPATHLEN
);
223 name2
= xmalloc (MAXPATHLEN
);
224 memset (name2
, 0, MAXPATHLEN
);
226 sprintf (name1
, "/proc/%d/exe", pid
);
227 if (readlink (name1
, name2
, MAXPATHLEN
) > 0)
239 /* Return non-zero if HEADER is a 64-bit ELF file. */
242 elf_64_header_p (const Elf64_Ehdr
*header
)
244 return (header
->e_ident
[EI_MAG0
] == ELFMAG0
245 && header
->e_ident
[EI_MAG1
] == ELFMAG1
246 && header
->e_ident
[EI_MAG2
] == ELFMAG2
247 && header
->e_ident
[EI_MAG3
] == ELFMAG3
248 && header
->e_ident
[EI_CLASS
] == ELFCLASS64
);
251 /* Return non-zero if FILE is a 64-bit ELF file,
252 zero if the file is not a 64-bit ELF file,
253 and -1 if the file is not accessible or doesn't exist. */
256 elf_64_file_p (const char *file
)
261 fd
= open (file
, O_RDONLY
);
265 if (read (fd
, &header
, sizeof (header
)) != sizeof (header
))
272 return elf_64_header_p (&header
);
276 delete_lwp (struct lwp_info
*lwp
)
278 remove_thread (get_lwp_thread (lwp
));
279 remove_inferior (&all_lwps
, &lwp
->head
);
280 free (lwp
->arch_private
);
284 /* Add a process to the common process list, and set its private
287 static struct process_info
*
288 linux_add_process (int pid
, int attached
)
290 struct process_info
*proc
;
292 /* Is this the first process? If so, then set the arch. */
293 if (all_processes
.head
== NULL
)
296 proc
= add_process (pid
, attached
);
297 proc
->private = xcalloc (1, sizeof (*proc
->private));
299 if (the_low_target
.new_process
!= NULL
)
300 proc
->private->arch_private
= the_low_target
.new_process ();
305 /* Wrapper function for waitpid which handles EINTR, and emulates
306 __WALL for systems where that is not available. */
309 my_waitpid (int pid
, int *status
, int flags
)
314 fprintf (stderr
, "my_waitpid (%d, 0x%x)\n", pid
, flags
);
318 sigset_t block_mask
, org_mask
, wake_mask
;
321 wnohang
= (flags
& WNOHANG
) != 0;
322 flags
&= ~(__WALL
| __WCLONE
);
325 /* Block all signals while here. This avoids knowing about
326 LinuxThread's signals. */
327 sigfillset (&block_mask
);
328 sigprocmask (SIG_BLOCK
, &block_mask
, &org_mask
);
330 /* ... except during the sigsuspend below. */
331 sigemptyset (&wake_mask
);
335 /* Since all signals are blocked, there's no need to check
337 ret
= waitpid (pid
, status
, flags
);
340 if (ret
== -1 && out_errno
!= ECHILD
)
345 if (flags
& __WCLONE
)
347 /* We've tried both flavors now. If WNOHANG is set,
348 there's nothing else to do, just bail out. */
353 fprintf (stderr
, "blocking\n");
355 /* Block waiting for signals. */
356 sigsuspend (&wake_mask
);
362 sigprocmask (SIG_SETMASK
, &org_mask
, NULL
);
367 ret
= waitpid (pid
, status
, flags
);
368 while (ret
== -1 && errno
== EINTR
);
373 fprintf (stderr
, "my_waitpid (%d, 0x%x): status(%x), %d\n",
374 pid
, flags
, status
? *status
: -1, ret
);
380 /* Handle a GNU/Linux extended wait response. If we see a clone
381 event, we need to add the new LWP to our list (and not report the
382 trap to higher layers). */
385 handle_extended_wait (struct lwp_info
*event_child
, int wstat
)
387 int event
= wstat
>> 16;
388 struct lwp_info
*new_lwp
;
390 if (event
== PTRACE_EVENT_CLONE
)
393 unsigned long new_pid
;
394 int ret
, status
= W_STOPCODE (SIGSTOP
);
396 ptrace (PTRACE_GETEVENTMSG
, lwpid_of (event_child
), 0, &new_pid
);
398 /* If we haven't already seen the new PID stop, wait for it now. */
399 if (! pull_pid_from_list (&stopped_pids
, new_pid
))
401 /* The new child has a pending SIGSTOP. We can't affect it until it
402 hits the SIGSTOP, but we're already attached. */
404 ret
= my_waitpid (new_pid
, &status
, __WALL
);
407 perror_with_name ("waiting for new child");
408 else if (ret
!= new_pid
)
409 warning ("wait returned unexpected PID %d", ret
);
410 else if (!WIFSTOPPED (status
))
411 warning ("wait returned unexpected status 0x%x", status
);
414 linux_enable_event_reporting (new_pid
);
416 ptid
= ptid_build (pid_of (event_child
), new_pid
, 0);
417 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
418 add_thread (ptid
, new_lwp
);
420 /* Either we're going to immediately resume the new thread
421 or leave it stopped. linux_resume_one_lwp is a nop if it
422 thinks the thread is currently running, so set this first
423 before calling linux_resume_one_lwp. */
424 new_lwp
->stopped
= 1;
426 /* Normally we will get the pending SIGSTOP. But in some cases
427 we might get another signal delivered to the group first.
428 If we do get another signal, be sure not to lose it. */
429 if (WSTOPSIG (status
) == SIGSTOP
)
431 if (stopping_threads
)
432 new_lwp
->stop_pc
= get_stop_pc (new_lwp
);
434 linux_resume_one_lwp (new_lwp
, 0, 0, NULL
);
438 new_lwp
->stop_expected
= 1;
440 if (stopping_threads
)
442 new_lwp
->stop_pc
= get_stop_pc (new_lwp
);
443 new_lwp
->status_pending_p
= 1;
444 new_lwp
->status_pending
= status
;
447 /* Pass the signal on. This is what GDB does - except
448 shouldn't we really report it instead? */
449 linux_resume_one_lwp (new_lwp
, 0, WSTOPSIG (status
), NULL
);
452 /* Always resume the current thread. If we are stopping
453 threads, it will have a pending SIGSTOP; we may as well
455 linux_resume_one_lwp (event_child
, event_child
->stepping
, 0, NULL
);
459 /* Return the PC as read from the regcache of LWP, without any
463 get_pc (struct lwp_info
*lwp
)
465 struct thread_info
*saved_inferior
;
466 struct regcache
*regcache
;
469 if (the_low_target
.get_pc
== NULL
)
472 saved_inferior
= current_inferior
;
473 current_inferior
= get_lwp_thread (lwp
);
475 regcache
= get_thread_regcache (current_inferior
, 1);
476 pc
= (*the_low_target
.get_pc
) (regcache
);
479 fprintf (stderr
, "pc is 0x%lx\n", (long) pc
);
481 current_inferior
= saved_inferior
;
485 /* This function should only be called if LWP got a SIGTRAP.
486 The SIGTRAP could mean several things.
488 On i386, where decr_pc_after_break is non-zero:
489 If we were single-stepping this process using PTRACE_SINGLESTEP,
490 we will get only the one SIGTRAP (even if the instruction we
491 stepped over was a breakpoint). The value of $eip will be the
493 If we continue the process using PTRACE_CONT, we will get a
494 SIGTRAP when we hit a breakpoint. The value of $eip will be
495 the instruction after the breakpoint (i.e. needs to be
496 decremented). If we report the SIGTRAP to GDB, we must also
497 report the undecremented PC. If we cancel the SIGTRAP, we
498 must resume at the decremented PC.
500 (Presumably, not yet tested) On a non-decr_pc_after_break machine
501 with hardware or kernel single-step:
502 If we single-step over a breakpoint instruction, our PC will
503 point at the following instruction. If we continue and hit a
504 breakpoint instruction, our PC will point at the breakpoint
508 get_stop_pc (struct lwp_info
*lwp
)
512 if (the_low_target
.get_pc
== NULL
)
515 stop_pc
= get_pc (lwp
);
517 if (WSTOPSIG (lwp
->last_status
) == SIGTRAP
519 && !lwp
->stopped_by_watchpoint
520 && lwp
->last_status
>> 16 == 0)
521 stop_pc
-= the_low_target
.decr_pc_after_break
;
524 fprintf (stderr
, "stop pc is 0x%lx\n", (long) stop_pc
);
530 add_lwp (ptid_t ptid
)
532 struct lwp_info
*lwp
;
534 lwp
= (struct lwp_info
*) xmalloc (sizeof (*lwp
));
535 memset (lwp
, 0, sizeof (*lwp
));
539 if (the_low_target
.new_thread
!= NULL
)
540 lwp
->arch_private
= the_low_target
.new_thread ();
542 add_inferior_to_list (&all_lwps
, &lwp
->head
);
547 /* Start an inferior process and returns its pid.
548 ALLARGS is a vector of program-name and args. */
551 linux_create_inferior (char *program
, char **allargs
)
553 struct lwp_info
*new_lwp
;
557 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
563 perror_with_name ("fork");
567 ptrace (PTRACE_TRACEME
, 0, 0, 0);
569 #ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
570 signal (__SIGRTMIN
+ 1, SIG_DFL
);
575 execv (program
, allargs
);
577 execvp (program
, allargs
);
579 fprintf (stderr
, "Cannot exec %s: %s.\n", program
,
585 linux_add_process (pid
, 0);
587 ptid
= ptid_build (pid
, pid
, 0);
588 new_lwp
= add_lwp (ptid
);
589 add_thread (ptid
, new_lwp
);
590 new_lwp
->must_set_ptrace_flags
= 1;
595 /* Attach to an inferior process. */
598 linux_attach_lwp_1 (unsigned long lwpid
, int initial
)
601 struct lwp_info
*new_lwp
;
603 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) != 0)
607 /* If we fail to attach to an LWP, just warn. */
608 fprintf (stderr
, "Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
609 strerror (errno
), errno
);
614 /* If we fail to attach to a process, report an error. */
615 error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
616 strerror (errno
), errno
);
620 /* NOTE/FIXME: This lwp might have not been the tgid. */
621 ptid
= ptid_build (lwpid
, lwpid
, 0);
624 /* Note that extracting the pid from the current inferior is
625 safe, since we're always called in the context of the same
626 process as this new thread. */
627 int pid
= pid_of (get_thread_lwp (current_inferior
));
628 ptid
= ptid_build (pid
, lwpid
, 0);
631 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
632 add_thread (ptid
, new_lwp
);
634 /* We need to wait for SIGSTOP before being able to make the next
635 ptrace call on this LWP. */
636 new_lwp
->must_set_ptrace_flags
= 1;
638 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
641 There are several cases to consider here:
643 1) gdbserver has already attached to the process and is being notified
644 of a new thread that is being created.
645 In this case we should ignore that SIGSTOP and resume the
646 process. This is handled below by setting stop_expected = 1,
647 and the fact that add_thread sets last_resume_kind ==
650 2) This is the first thread (the process thread), and we're attaching
651 to it via attach_inferior.
652 In this case we want the process thread to stop.
653 This is handled by having linux_attach set last_resume_kind ==
654 resume_stop after we return.
655 ??? If the process already has several threads we leave the other
658 3) GDB is connecting to gdbserver and is requesting an enumeration of all
660 In this case we want the thread to stop.
661 FIXME: This case is currently not properly handled.
662 We should wait for the SIGSTOP but don't. Things work apparently
663 because enough time passes between when we ptrace (ATTACH) and when
664 gdb makes the next ptrace call on the thread.
666 On the other hand, if we are currently trying to stop all threads, we
667 should treat the new thread as if we had sent it a SIGSTOP. This works
668 because we are guaranteed that the add_lwp call above added us to the
669 end of the list, and so the new thread has not yet reached
670 wait_for_sigstop (but will). */
671 new_lwp
->stop_expected
= 1;
675 linux_attach_lwp (unsigned long lwpid
)
677 linux_attach_lwp_1 (lwpid
, 0);
681 linux_attach (unsigned long pid
)
683 linux_attach_lwp_1 (pid
, 1);
684 linux_add_process (pid
, 1);
688 struct thread_info
*thread
;
690 /* Don't ignore the initial SIGSTOP if we just attached to this
691 process. It will be collected by wait shortly. */
692 thread
= find_thread_ptid (ptid_build (pid
, pid
, 0));
693 thread
->last_resume_kind
= resume_stop
;
706 second_thread_of_pid_p (struct inferior_list_entry
*entry
, void *args
)
708 struct counter
*counter
= args
;
710 if (ptid_get_pid (entry
->id
) == counter
->pid
)
712 if (++counter
->count
> 1)
720 last_thread_of_process_p (struct thread_info
*thread
)
722 ptid_t ptid
= ((struct inferior_list_entry
*)thread
)->id
;
723 int pid
= ptid_get_pid (ptid
);
724 struct counter counter
= { pid
, 0 };
726 return (find_inferior (&all_threads
,
727 second_thread_of_pid_p
, &counter
) == NULL
);
730 /* Kill the inferior lwp. */
733 linux_kill_one_lwp (struct inferior_list_entry
*entry
, void *args
)
735 struct thread_info
*thread
= (struct thread_info
*) entry
;
736 struct lwp_info
*lwp
= get_thread_lwp (thread
);
738 int pid
= * (int *) args
;
740 if (ptid_get_pid (entry
->id
) != pid
)
743 /* We avoid killing the first thread here, because of a Linux kernel (at
744 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
745 the children get a chance to be reaped, it will remain a zombie
748 if (lwpid_of (lwp
) == pid
)
751 fprintf (stderr
, "lkop: is last of process %s\n",
752 target_pid_to_str (entry
->id
));
758 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
760 /* Make sure it died. The loop is most likely unnecessary. */
761 pid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
762 } while (pid
> 0 && WIFSTOPPED (wstat
));
770 struct process_info
*process
;
771 struct lwp_info
*lwp
;
772 struct thread_info
*thread
;
776 process
= find_process_pid (pid
);
780 /* If we're killing a running inferior, make sure it is stopped
781 first, as PTRACE_KILL will not work otherwise. */
782 stop_all_lwps (0, NULL
);
784 find_inferior (&all_threads
, linux_kill_one_lwp
, &pid
);
786 /* See the comment in linux_kill_one_lwp. We did not kill the first
787 thread in the list, so do so now. */
788 lwp
= find_lwp_pid (pid_to_ptid (pid
));
789 thread
= get_lwp_thread (lwp
);
792 fprintf (stderr
, "lk_1: killing lwp %ld, for pid: %d\n",
793 lwpid_of (lwp
), pid
);
797 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
799 /* Make sure it died. The loop is most likely unnecessary. */
800 lwpid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
801 } while (lwpid
> 0 && WIFSTOPPED (wstat
));
803 the_target
->mourn (process
);
805 /* Since we presently can only stop all lwps of all processes, we
806 need to unstop lwps of other processes. */
807 unstop_all_lwps (0, NULL
);
812 linux_detach_one_lwp (struct inferior_list_entry
*entry
, void *args
)
814 struct thread_info
*thread
= (struct thread_info
*) entry
;
815 struct lwp_info
*lwp
= get_thread_lwp (thread
);
816 int pid
= * (int *) args
;
818 if (ptid_get_pid (entry
->id
) != pid
)
821 /* If this process is stopped but is expecting a SIGSTOP, then make
822 sure we take care of that now. This isn't absolutely guaranteed
823 to collect the SIGSTOP, but is fairly likely to. */
824 if (lwp
->stop_expected
)
827 /* Clear stop_expected, so that the SIGSTOP will be reported. */
828 lwp
->stop_expected
= 0;
829 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
830 linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
833 /* Flush any pending changes to the process's registers. */
834 regcache_invalidate_one ((struct inferior_list_entry
*)
835 get_lwp_thread (lwp
));
837 /* Finally, let it resume. */
838 ptrace (PTRACE_DETACH
, lwpid_of (lwp
), 0, 0);
845 linux_detach (int pid
)
847 struct process_info
*process
;
849 process
= find_process_pid (pid
);
853 /* Stop all threads before detaching. First, ptrace requires that
854 the thread is stopped to sucessfully detach. Second, thread_db
855 may need to uninstall thread event breakpoints from memory, which
856 only works with a stopped process anyway. */
857 stop_all_lwps (0, NULL
);
860 thread_db_detach (process
);
863 /* Stabilize threads (move out of jump pads). */
864 stabilize_threads ();
866 find_inferior (&all_threads
, linux_detach_one_lwp
, &pid
);
868 the_target
->mourn (process
);
870 /* Since we presently can only stop all lwps of all processes, we
871 need to unstop lwps of other processes. */
872 unstop_all_lwps (0, NULL
);
876 /* Remove all LWPs that belong to process PROC from the lwp list. */
879 delete_lwp_callback (struct inferior_list_entry
*entry
, void *proc
)
881 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
882 struct process_info
*process
= proc
;
884 if (pid_of (lwp
) == pid_of (process
))
891 linux_mourn (struct process_info
*process
)
893 struct process_info_private
*priv
;
896 thread_db_mourn (process
);
899 find_inferior (&all_lwps
, delete_lwp_callback
, process
);
901 /* Freeing all private data. */
902 priv
= process
->private;
903 free (priv
->arch_private
);
905 process
->private = NULL
;
907 remove_process (process
);
914 struct process_info
*process
;
916 process
= find_process_pid (pid
);
921 ret
= my_waitpid (pid
, &status
, 0);
922 if (WIFEXITED (status
) || WIFSIGNALED (status
))
924 } while (ret
!= -1 || errno
!= ECHILD
);
927 /* Return nonzero if the given thread is still alive. */
929 linux_thread_alive (ptid_t ptid
)
931 struct lwp_info
*lwp
= find_lwp_pid (ptid
);
933 /* We assume we always know if a thread exits. If a whole process
934 exited but we still haven't been able to report it to GDB, we'll
935 hold on to the last lwp of the dead process. */
942 /* Return 1 if this lwp has an interesting status pending. */
944 status_pending_p_callback (struct inferior_list_entry
*entry
, void *arg
)
946 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
947 ptid_t ptid
= * (ptid_t
*) arg
;
948 struct thread_info
*thread
;
950 /* Check if we're only interested in events from a specific process
952 if (!ptid_equal (minus_one_ptid
, ptid
)
953 && ptid_get_pid (ptid
) != ptid_get_pid (lwp
->head
.id
))
956 thread
= get_lwp_thread (lwp
);
958 /* If we got a `vCont;t', but we haven't reported a stop yet, do
959 report any status pending the LWP may have. */
960 if (thread
->last_resume_kind
== resume_stop
961 && thread
->last_status
.kind
!= TARGET_WAITKIND_IGNORE
)
964 return lwp
->status_pending_p
;
968 same_lwp (struct inferior_list_entry
*entry
, void *data
)
970 ptid_t ptid
= *(ptid_t
*) data
;
973 if (ptid_get_lwp (ptid
) != 0)
974 lwp
= ptid_get_lwp (ptid
);
976 lwp
= ptid_get_pid (ptid
);
978 if (ptid_get_lwp (entry
->id
) == lwp
)
985 find_lwp_pid (ptid_t ptid
)
987 return (struct lwp_info
*) find_inferior (&all_lwps
, same_lwp
, &ptid
);
990 static struct lwp_info
*
991 linux_wait_for_lwp (ptid_t ptid
, int *wstatp
, int options
)
994 int to_wait_for
= -1;
995 struct lwp_info
*child
= NULL
;
998 fprintf (stderr
, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid
));
1000 if (ptid_equal (ptid
, minus_one_ptid
))
1001 to_wait_for
= -1; /* any child */
1003 to_wait_for
= ptid_get_lwp (ptid
); /* this lwp only */
1009 ret
= my_waitpid (to_wait_for
, wstatp
, options
);
1010 if (ret
== 0 || (ret
== -1 && errno
== ECHILD
&& (options
& WNOHANG
)))
1013 perror_with_name ("waitpid");
1016 && (!WIFSTOPPED (*wstatp
)
1017 || (WSTOPSIG (*wstatp
) != 32
1018 && WSTOPSIG (*wstatp
) != 33)))
1019 fprintf (stderr
, "Got an event from %d (%x)\n", ret
, *wstatp
);
1021 child
= find_lwp_pid (pid_to_ptid (ret
));
1023 /* If we didn't find a process, one of two things presumably happened:
1024 - A process we started and then detached from has exited. Ignore it.
1025 - A process we are controlling has forked and the new child's stop
1026 was reported to us by the kernel. Save its PID. */
1027 if (child
== NULL
&& WIFSTOPPED (*wstatp
))
1029 add_pid_to_list (&stopped_pids
, ret
);
1032 else if (child
== NULL
)
1037 child
->last_status
= *wstatp
;
1039 /* Architecture-specific setup after inferior is running.
1040 This needs to happen after we have attached to the inferior
1041 and it is stopped for the first time, but before we access
1042 any inferior registers. */
1045 the_low_target
.arch_setup ();
1046 #ifdef HAVE_LINUX_REGSETS
1047 memset (disabled_regsets
, 0, num_regsets
);
1052 /* Fetch the possibly triggered data watchpoint info and store it in
1055 On some archs, like x86, that use debug registers to set
1056 watchpoints, it's possible that the way to know which watched
1057 address trapped, is to check the register that is used to select
1058 which address to watch. Problem is, between setting the
1059 watchpoint and reading back which data address trapped, the user
1060 may change the set of watchpoints, and, as a consequence, GDB
1061 changes the debug registers in the inferior. To avoid reading
1062 back a stale stopped-data-address when that happens, we cache in
1063 LP the fact that a watchpoint trapped, and the corresponding data
1064 address, as soon as we see CHILD stop with a SIGTRAP. If GDB
1065 changes the debug registers meanwhile, we have the cached data we
1068 if (WIFSTOPPED (*wstatp
) && WSTOPSIG (*wstatp
) == SIGTRAP
)
1070 if (the_low_target
.stopped_by_watchpoint
== NULL
)
1072 child
->stopped_by_watchpoint
= 0;
1076 struct thread_info
*saved_inferior
;
1078 saved_inferior
= current_inferior
;
1079 current_inferior
= get_lwp_thread (child
);
1081 child
->stopped_by_watchpoint
1082 = the_low_target
.stopped_by_watchpoint ();
1084 if (child
->stopped_by_watchpoint
)
1086 if (the_low_target
.stopped_data_address
!= NULL
)
1087 child
->stopped_data_address
1088 = the_low_target
.stopped_data_address ();
1090 child
->stopped_data_address
= 0;
1093 current_inferior
= saved_inferior
;
1097 /* Store the STOP_PC, with adjustment applied. This depends on the
1098 architecture being defined already (so that CHILD has a valid
1099 regcache), and on LAST_STATUS being set (to check for SIGTRAP or
1101 if (WIFSTOPPED (*wstatp
))
1102 child
->stop_pc
= get_stop_pc (child
);
1105 && WIFSTOPPED (*wstatp
)
1106 && the_low_target
.get_pc
!= NULL
)
1108 struct thread_info
*saved_inferior
= current_inferior
;
1109 struct regcache
*regcache
;
1112 current_inferior
= get_lwp_thread (child
);
1113 regcache
= get_thread_regcache (current_inferior
, 1);
1114 pc
= (*the_low_target
.get_pc
) (regcache
);
1115 fprintf (stderr
, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc
);
1116 current_inferior
= saved_inferior
;
1122 /* This function should only be called if the LWP got a SIGTRAP.
1124 Handle any tracepoint steps or hits. Return true if a tracepoint
1125 event was handled, 0 otherwise. */
1128 handle_tracepoints (struct lwp_info
*lwp
)
1130 struct thread_info
*tinfo
= get_lwp_thread (lwp
);
1131 int tpoint_related_event
= 0;
1133 /* If this tracepoint hit causes a tracing stop, we'll immediately
1134 uninsert tracepoints. To do this, we temporarily pause all
1135 threads, unpatch away, and then unpause threads. We need to make
1136 sure the unpausing doesn't resume LWP too. */
1139 /* And we need to be sure that any all-threads-stopping doesn't try
1140 to move threads out of the jump pads, as it could deadlock the
1141 inferior (LWP could be in the jump pad, maybe even holding the
1144 /* Do any necessary step collect actions. */
1145 tpoint_related_event
|= tracepoint_finished_step (tinfo
, lwp
->stop_pc
);
1147 tpoint_related_event
|= handle_tracepoint_bkpts (tinfo
, lwp
->stop_pc
);
1149 /* See if we just hit a tracepoint and do its main collect
1151 tpoint_related_event
|= tracepoint_was_hit (tinfo
, lwp
->stop_pc
);
1155 gdb_assert (lwp
->suspended
== 0);
1156 gdb_assert (!stabilizing_threads
|| lwp
->collecting_fast_tracepoint
);
1158 if (tpoint_related_event
)
1161 fprintf (stderr
, "got a tracepoint event\n");
1168 /* Convenience wrapper. Returns true if LWP is presently collecting a
1172 linux_fast_tracepoint_collecting (struct lwp_info
*lwp
,
1173 struct fast_tpoint_collect_status
*status
)
1175 CORE_ADDR thread_area
;
1177 if (the_low_target
.get_thread_area
== NULL
)
1180 /* Get the thread area address. This is used to recognize which
1181 thread is which when tracing with the in-process agent library.
1182 We don't read anything from the address, and treat it as opaque;
1183 it's the address itself that we assume is unique per-thread. */
1184 if ((*the_low_target
.get_thread_area
) (lwpid_of (lwp
), &thread_area
) == -1)
1187 return fast_tracepoint_collecting (thread_area
, lwp
->stop_pc
, status
);
1190 /* The reason we resume in the caller, is because we want to be able
1191 to pass lwp->status_pending as WSTAT, and we need to clear
1192 status_pending_p before resuming, otherwise, linux_resume_one_lwp
1193 refuses to resume. */
1196 maybe_move_out_of_jump_pad (struct lwp_info
*lwp
, int *wstat
)
1198 struct thread_info
*saved_inferior
;
1200 saved_inferior
= current_inferior
;
1201 current_inferior
= get_lwp_thread (lwp
);
1204 || (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) != SIGTRAP
))
1205 && supports_fast_tracepoints ()
1206 && in_process_agent_loaded ())
1208 struct fast_tpoint_collect_status status
;
1213 Checking whether LWP %ld needs to move out of the jump pad.\n",
1216 r
= linux_fast_tracepoint_collecting (lwp
, &status
);
1219 || (WSTOPSIG (*wstat
) != SIGILL
1220 && WSTOPSIG (*wstat
) != SIGFPE
1221 && WSTOPSIG (*wstat
) != SIGSEGV
1222 && WSTOPSIG (*wstat
) != SIGBUS
))
1224 lwp
->collecting_fast_tracepoint
= r
;
1228 if (r
== 1 && lwp
->exit_jump_pad_bkpt
== NULL
)
1230 /* Haven't executed the original instruction yet.
1231 Set breakpoint there, and wait till it's hit,
1232 then single-step until exiting the jump pad. */
1233 lwp
->exit_jump_pad_bkpt
1234 = set_breakpoint_at (status
.adjusted_insn_addr
, NULL
);
1239 Checking whether LWP %ld needs to move out of the jump pad...it does\n",
1247 /* If we get a synchronous signal while collecting, *and*
1248 while executing the (relocated) original instruction,
1249 reset the PC to point at the tpoint address, before
1250 reporting to GDB. Otherwise, it's an IPA lib bug: just
1251 report the signal to GDB, and pray for the best. */
1253 lwp
->collecting_fast_tracepoint
= 0;
1256 && (status
.adjusted_insn_addr
<= lwp
->stop_pc
1257 && lwp
->stop_pc
< status
.adjusted_insn_addr_end
))
1260 struct regcache
*regcache
;
1262 /* The si_addr on a few signals references the address
1263 of the faulting instruction. Adjust that as
1265 if ((WSTOPSIG (*wstat
) == SIGILL
1266 || WSTOPSIG (*wstat
) == SIGFPE
1267 || WSTOPSIG (*wstat
) == SIGBUS
1268 || WSTOPSIG (*wstat
) == SIGSEGV
)
1269 && ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &info
) == 0
1270 /* Final check just to make sure we don't clobber
1271 the siginfo of non-kernel-sent signals. */
1272 && (uintptr_t) info
.si_addr
== lwp
->stop_pc
)
1274 info
.si_addr
= (void *) (uintptr_t) status
.tpoint_addr
;
1275 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &info
);
1278 regcache
= get_thread_regcache (get_lwp_thread (lwp
), 1);
1279 (*the_low_target
.set_pc
) (regcache
, status
.tpoint_addr
);
1280 lwp
->stop_pc
= status
.tpoint_addr
;
1282 /* Cancel any fast tracepoint lock this thread was
1284 force_unlock_trace_buffer ();
1287 if (lwp
->exit_jump_pad_bkpt
!= NULL
)
1291 "Cancelling fast exit-jump-pad: removing bkpt. "
1292 "stopping all threads momentarily.\n");
1294 stop_all_lwps (1, lwp
);
1295 cancel_breakpoints ();
1297 delete_breakpoint (lwp
->exit_jump_pad_bkpt
);
1298 lwp
->exit_jump_pad_bkpt
= NULL
;
1300 unstop_all_lwps (1, lwp
);
1302 gdb_assert (lwp
->suspended
>= 0);
1309 Checking whether LWP %ld needs to move out of the jump pad...no\n",
1314 /* Enqueue one signal in the "signals to report later when out of the
1318 enqueue_one_deferred_signal (struct lwp_info
*lwp
, int *wstat
)
1320 struct pending_signals
*p_sig
;
1324 Deferring signal %d for LWP %ld.\n", WSTOPSIG (*wstat
), lwpid_of (lwp
));
1328 struct pending_signals
*sig
;
1330 for (sig
= lwp
->pending_signals_to_report
;
1334 " Already queued %d\n",
1337 fprintf (stderr
, " (no more currently queued signals)\n");
1340 p_sig
= xmalloc (sizeof (*p_sig
));
1341 p_sig
->prev
= lwp
->pending_signals_to_report
;
1342 p_sig
->signal
= WSTOPSIG (*wstat
);
1343 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
1344 ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &p_sig
->info
);
1346 lwp
->pending_signals_to_report
= p_sig
;
1349 /* Dequeue one signal from the "signals to report later when out of
1350 the jump pad" list. */
1353 dequeue_one_deferred_signal (struct lwp_info
*lwp
, int *wstat
)
1355 if (lwp
->pending_signals_to_report
!= NULL
)
1357 struct pending_signals
**p_sig
;
1359 p_sig
= &lwp
->pending_signals_to_report
;
1360 while ((*p_sig
)->prev
!= NULL
)
1361 p_sig
= &(*p_sig
)->prev
;
1363 *wstat
= W_STOPCODE ((*p_sig
)->signal
);
1364 if ((*p_sig
)->info
.si_signo
!= 0)
1365 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &(*p_sig
)->info
);
1370 fprintf (stderr
, "Reporting deferred signal %d for LWP %ld.\n",
1371 WSTOPSIG (*wstat
), lwpid_of (lwp
));
1375 struct pending_signals
*sig
;
1377 for (sig
= lwp
->pending_signals_to_report
;
1381 " Still queued %d\n",
1384 fprintf (stderr
, " (no more queued signals)\n");
1393 /* Arrange for a breakpoint to be hit again later. We don't keep the
1394 SIGTRAP status and don't forward the SIGTRAP signal to the LWP. We
1395 will handle the current event, eventually we will resume this LWP,
1396 and this breakpoint will trap again. */
1399 cancel_breakpoint (struct lwp_info
*lwp
)
1401 struct thread_info
*saved_inferior
;
1403 /* There's nothing to do if we don't support breakpoints. */
1404 if (!supports_breakpoints ())
1407 /* breakpoint_at reads from current inferior. */
1408 saved_inferior
= current_inferior
;
1409 current_inferior
= get_lwp_thread (lwp
);
1411 if ((*the_low_target
.breakpoint_at
) (lwp
->stop_pc
))
1415 "CB: Push back breakpoint for %s\n",
1416 target_pid_to_str (ptid_of (lwp
)));
1418 /* Back up the PC if necessary. */
1419 if (the_low_target
.decr_pc_after_break
)
1421 struct regcache
*regcache
1422 = get_thread_regcache (current_inferior
, 1);
1423 (*the_low_target
.set_pc
) (regcache
, lwp
->stop_pc
);
1426 current_inferior
= saved_inferior
;
1433 "CB: No breakpoint found at %s for [%s]\n",
1434 paddress (lwp
->stop_pc
),
1435 target_pid_to_str (ptid_of (lwp
)));
1438 current_inferior
= saved_inferior
;
1442 /* When the event-loop is doing a step-over, this points at the thread
1444 ptid_t step_over_bkpt
;
1446 /* Wait for an event from child PID. If PID is -1, wait for any
1447 child. Store the stop status through the status pointer WSTAT.
1448 OPTIONS is passed to the waitpid call. Return 0 if no child stop
1449 event was found and OPTIONS contains WNOHANG. Return the PID of
1450 the stopped child otherwise. */
1453 linux_wait_for_event_1 (ptid_t ptid
, int *wstat
, int options
)
1455 struct lwp_info
*event_child
, *requested_child
;
1458 requested_child
= NULL
;
1460 /* Check for a lwp with a pending status. */
1462 if (ptid_equal (ptid
, minus_one_ptid
)
1463 || ptid_equal (pid_to_ptid (ptid_get_pid (ptid
)), ptid
))
1465 event_child
= (struct lwp_info
*)
1466 find_inferior (&all_lwps
, status_pending_p_callback
, &ptid
);
1467 if (debug_threads
&& event_child
)
1468 fprintf (stderr
, "Got a pending child %ld\n", lwpid_of (event_child
));
1472 requested_child
= find_lwp_pid (ptid
);
1474 if (!stopping_threads
1475 && requested_child
->status_pending_p
1476 && requested_child
->collecting_fast_tracepoint
)
1478 enqueue_one_deferred_signal (requested_child
,
1479 &requested_child
->status_pending
);
1480 requested_child
->status_pending_p
= 0;
1481 requested_child
->status_pending
= 0;
1482 linux_resume_one_lwp (requested_child
, 0, 0, NULL
);
1485 if (requested_child
->suspended
1486 && requested_child
->status_pending_p
)
1487 fatal ("requesting an event out of a suspended child?");
1489 if (requested_child
->status_pending_p
)
1490 event_child
= requested_child
;
1493 if (event_child
!= NULL
)
1496 fprintf (stderr
, "Got an event from pending child %ld (%04x)\n",
1497 lwpid_of (event_child
), event_child
->status_pending
);
1498 *wstat
= event_child
->status_pending
;
1499 event_child
->status_pending_p
= 0;
1500 event_child
->status_pending
= 0;
1501 current_inferior
= get_lwp_thread (event_child
);
1502 return lwpid_of (event_child
);
1505 /* We only enter this loop if no process has a pending wait status. Thus
1506 any action taken in response to a wait status inside this loop is
1507 responding as soon as we detect the status, not after any pending
1511 event_child
= linux_wait_for_lwp (ptid
, wstat
, options
);
1513 if ((options
& WNOHANG
) && event_child
== NULL
)
1516 fprintf (stderr
, "WNOHANG set, no event found\n");
1520 if (event_child
== NULL
)
1521 error ("event from unknown child");
1523 current_inferior
= get_lwp_thread (event_child
);
1525 /* Check for thread exit. */
1526 if (! WIFSTOPPED (*wstat
))
1529 fprintf (stderr
, "LWP %ld exiting\n", lwpid_of (event_child
));
1531 /* If the last thread is exiting, just return. */
1532 if (last_thread_of_process_p (current_inferior
))
1535 fprintf (stderr
, "LWP %ld is last lwp of process\n",
1536 lwpid_of (event_child
));
1537 return lwpid_of (event_child
);
1542 current_inferior
= (struct thread_info
*) all_threads
.head
;
1544 fprintf (stderr
, "Current inferior is now %ld\n",
1545 lwpid_of (get_thread_lwp (current_inferior
)));
1549 current_inferior
= NULL
;
1551 fprintf (stderr
, "Current inferior is now <NULL>\n");
1554 /* If we were waiting for this particular child to do something...
1555 well, it did something. */
1556 if (requested_child
!= NULL
)
1558 int lwpid
= lwpid_of (event_child
);
1560 /* Cancel the step-over operation --- the thread that
1561 started it is gone. */
1562 if (finish_step_over (event_child
))
1563 unstop_all_lwps (1, event_child
);
1564 delete_lwp (event_child
);
1568 delete_lwp (event_child
);
1570 /* Wait for a more interesting event. */
1574 if (event_child
->must_set_ptrace_flags
)
1576 linux_enable_event_reporting (lwpid_of (event_child
));
1577 event_child
->must_set_ptrace_flags
= 0;
1580 if (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) == SIGTRAP
1581 && *wstat
>> 16 != 0)
1583 handle_extended_wait (event_child
, *wstat
);
1587 if (WIFSTOPPED (*wstat
)
1588 && WSTOPSIG (*wstat
) == SIGSTOP
1589 && event_child
->stop_expected
)
1594 fprintf (stderr
, "Expected stop.\n");
1595 event_child
->stop_expected
= 0;
1597 should_stop
= (current_inferior
->last_resume_kind
== resume_stop
1598 || stopping_threads
);
1602 linux_resume_one_lwp (event_child
,
1603 event_child
->stepping
, 0, NULL
);
1608 return lwpid_of (event_child
);
1616 linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
)
1620 if (ptid_is_pid (ptid
))
1622 /* A request to wait for a specific tgid. This is not possible
1623 with waitpid, so instead, we wait for any child, and leave
1624 children we're not interested in right now with a pending
1625 status to report later. */
1626 wait_ptid
= minus_one_ptid
;
1635 event_pid
= linux_wait_for_event_1 (wait_ptid
, wstat
, options
);
1638 && ptid_is_pid (ptid
) && ptid_get_pid (ptid
) != event_pid
)
1640 struct lwp_info
*event_child
= find_lwp_pid (pid_to_ptid (event_pid
));
1642 if (! WIFSTOPPED (*wstat
))
1643 mark_lwp_dead (event_child
, *wstat
);
1646 event_child
->status_pending_p
= 1;
1647 event_child
->status_pending
= *wstat
;
1656 /* Count the LWP's that have had events. */
1659 count_events_callback (struct inferior_list_entry
*entry
, void *data
)
1661 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1662 struct thread_info
*thread
= get_lwp_thread (lp
);
1665 gdb_assert (count
!= NULL
);
1667 /* Count only resumed LWPs that have a SIGTRAP event pending that
1668 should be reported to GDB. */
1669 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1670 && thread
->last_resume_kind
!= resume_stop
1671 && lp
->status_pending_p
1672 && WIFSTOPPED (lp
->status_pending
)
1673 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1674 && !breakpoint_inserted_here (lp
->stop_pc
))
1680 /* Select the LWP (if any) that is currently being single-stepped. */
1683 select_singlestep_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
1685 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1686 struct thread_info
*thread
= get_lwp_thread (lp
);
1688 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1689 && thread
->last_resume_kind
== resume_step
1690 && lp
->status_pending_p
)
1696 /* Select the Nth LWP that has had a SIGTRAP event that should be
1700 select_event_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
1702 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1703 struct thread_info
*thread
= get_lwp_thread (lp
);
1704 int *selector
= data
;
1706 gdb_assert (selector
!= NULL
);
1708 /* Select only resumed LWPs that have a SIGTRAP event pending. */
1709 if (thread
->last_resume_kind
!= resume_stop
1710 && thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1711 && lp
->status_pending_p
1712 && WIFSTOPPED (lp
->status_pending
)
1713 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1714 && !breakpoint_inserted_here (lp
->stop_pc
))
1715 if ((*selector
)-- == 0)
1722 cancel_breakpoints_callback (struct inferior_list_entry
*entry
, void *data
)
1724 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1725 struct thread_info
*thread
= get_lwp_thread (lp
);
1726 struct lwp_info
*event_lp
= data
;
1728 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
1732 /* If a LWP other than the LWP that we're reporting an event for has
1733 hit a GDB breakpoint (as opposed to some random trap signal),
1734 then just arrange for it to hit it again later. We don't keep
1735 the SIGTRAP status and don't forward the SIGTRAP signal to the
1736 LWP. We will handle the current event, eventually we will resume
1737 all LWPs, and this one will get its breakpoint trap again.
1739 If we do not do this, then we run the risk that the user will
1740 delete or disable the breakpoint, but the LWP will have already
1743 if (thread
->last_resume_kind
!= resume_stop
1744 && thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1745 && lp
->status_pending_p
1746 && WIFSTOPPED (lp
->status_pending
)
1747 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1749 && !lp
->stopped_by_watchpoint
1750 && cancel_breakpoint (lp
))
1751 /* Throw away the SIGTRAP. */
1752 lp
->status_pending_p
= 0;
1758 linux_cancel_breakpoints (void)
1760 find_inferior (&all_lwps
, cancel_breakpoints_callback
, NULL
);
1763 /* Select one LWP out of those that have events pending. */
1766 select_event_lwp (struct lwp_info
**orig_lp
)
1769 int random_selector
;
1770 struct lwp_info
*event_lp
;
1772 /* Give preference to any LWP that is being single-stepped. */
1774 = (struct lwp_info
*) find_inferior (&all_lwps
,
1775 select_singlestep_lwp_callback
, NULL
);
1776 if (event_lp
!= NULL
)
1780 "SEL: Select single-step %s\n",
1781 target_pid_to_str (ptid_of (event_lp
)));
1785 /* No single-stepping LWP. Select one at random, out of those
1786 which have had SIGTRAP events. */
1788 /* First see how many SIGTRAP events we have. */
1789 find_inferior (&all_lwps
, count_events_callback
, &num_events
);
1791 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
1792 random_selector
= (int)
1793 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
1795 if (debug_threads
&& num_events
> 1)
1797 "SEL: Found %d SIGTRAP events, selecting #%d\n",
1798 num_events
, random_selector
);
1800 event_lp
= (struct lwp_info
*) find_inferior (&all_lwps
,
1801 select_event_lwp_callback
,
1805 if (event_lp
!= NULL
)
1807 /* Switch the event LWP. */
1808 *orig_lp
= event_lp
;
1812 /* Set this inferior LWP's state as "want-stopped". We won't resume
1813 this LWP until the client gives us another action for it. */
1816 gdb_wants_lwp_stopped (struct inferior_list_entry
*entry
)
1818 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1819 struct thread_info
*thread
= get_lwp_thread (lwp
);
1821 /* Most threads are stopped implicitly (all-stop); tag that with
1822 signal 0. The thread being explicitly reported stopped to the
1823 client, gets it's status fixed up afterwards. */
1824 thread
->last_status
.kind
= TARGET_WAITKIND_STOPPED
;
1825 thread
->last_status
.value
.sig
= TARGET_SIGNAL_0
;
1827 thread
->last_resume_kind
= resume_stop
;
1830 /* Decrement the suspend count of an LWP. */
1833 unsuspend_one_lwp (struct inferior_list_entry
*entry
, void *except
)
1835 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1837 /* Ignore EXCEPT. */
1843 gdb_assert (lwp
->suspended
>= 0);
1847 /* Decrement the suspend count of all LWPs, except EXCEPT, if non
1851 unsuspend_all_lwps (struct lwp_info
*except
)
1853 find_inferior (&all_lwps
, unsuspend_one_lwp
, except
);
1856 /* Set all LWP's states as "want-stopped". */
1859 gdb_wants_all_stopped (void)
1861 for_each_inferior (&all_lwps
, gdb_wants_lwp_stopped
);
1864 static void move_out_of_jump_pad_callback (struct inferior_list_entry
*entry
);
1865 static int stuck_in_jump_pad_callback (struct inferior_list_entry
*entry
,
1867 static int lwp_running (struct inferior_list_entry
*entry
, void *data
);
1868 static ptid_t
linux_wait_1 (ptid_t ptid
,
1869 struct target_waitstatus
*ourstatus
,
1870 int target_options
);
1872 /* Stabilize threads (move out of jump pads).
1874 If a thread is midway collecting a fast tracepoint, we need to
1875 finish the collection and move it out of the jump pad before
1876 reporting the signal.
1878 This avoids recursion while collecting (when a signal arrives
1879 midway, and the signal handler itself collects), which would trash
1880 the trace buffer. In case the user set a breakpoint in a signal
1881 handler, this avoids the backtrace showing the jump pad, etc..
1882 Most importantly, there are certain things we can't do safely if
1883 threads are stopped in a jump pad (or in its callee's). For
1886 - starting a new trace run. A thread still collecting the
1887 previous run, could trash the trace buffer when resumed. The trace
1888 buffer control structures would have been reset but the thread had
1889 no way to tell. The thread could even midway memcpy'ing to the
1890 buffer, which would mean that when resumed, it would clobber the
1891 trace buffer that had been set for a new run.
1893 - we can't rewrite/reuse the jump pads for new tracepoints
1894 safely. Say you do tstart while a thread is stopped midway while
1895 collecting. When the thread is later resumed, it finishes the
1896 collection, and returns to the jump pad, to execute the original
1897 instruction that was under the tracepoint jump at the time the
1898 older run had been started. If the jump pad had been rewritten
1899 since for something else in the new run, the thread would now
1900 execute the wrong / random instructions. */
1903 linux_stabilize_threads (void)
1905 struct thread_info
*save_inferior
;
1906 struct lwp_info
*lwp_stuck
;
1909 = (struct lwp_info
*) find_inferior (&all_lwps
,
1910 stuck_in_jump_pad_callback
, NULL
);
1911 if (lwp_stuck
!= NULL
)
1913 fprintf (stderr
, "can't stabilize, LWP %ld is stuck in jump pad\n",
1914 lwpid_of (lwp_stuck
));
1918 save_inferior
= current_inferior
;
1920 stabilizing_threads
= 1;
1923 for_each_inferior (&all_lwps
, move_out_of_jump_pad_callback
);
1925 /* Loop until all are stopped out of the jump pads. */
1926 while (find_inferior (&all_lwps
, lwp_running
, NULL
) != NULL
)
1928 struct target_waitstatus ourstatus
;
1929 struct lwp_info
*lwp
;
1933 /* Note that we go through the full wait even loop. While
1934 moving threads out of jump pad, we need to be able to step
1935 over internal breakpoints and such. */
1936 ptid
= linux_wait_1 (minus_one_ptid
, &ourstatus
, 0);
1938 if (ourstatus
.kind
== TARGET_WAITKIND_STOPPED
)
1940 lwp
= get_thread_lwp (current_inferior
);
1945 if (ourstatus
.value
.sig
!= TARGET_SIGNAL_0
1946 || current_inferior
->last_resume_kind
== resume_stop
)
1948 wstat
= W_STOPCODE (target_signal_to_host (ourstatus
.value
.sig
));
1949 enqueue_one_deferred_signal (lwp
, &wstat
);
1954 find_inferior (&all_lwps
, unsuspend_one_lwp
, NULL
);
1956 stabilizing_threads
= 0;
1958 current_inferior
= save_inferior
;
1961 = (struct lwp_info
*) find_inferior (&all_lwps
,
1962 stuck_in_jump_pad_callback
, NULL
);
1963 if (lwp_stuck
!= NULL
)
1966 fprintf (stderr
, "couldn't stabilize, LWP %ld got stuck in jump pad\n",
1967 lwpid_of (lwp_stuck
));
1971 /* Wait for process, returns status. */
1974 linux_wait_1 (ptid_t ptid
,
1975 struct target_waitstatus
*ourstatus
, int target_options
)
1978 struct lwp_info
*event_child
;
1981 int step_over_finished
;
1982 int bp_explains_trap
;
1983 int maybe_internal_trap
;
1987 /* Translate generic target options into linux options. */
1989 if (target_options
& TARGET_WNOHANG
)
1993 bp_explains_trap
= 0;
1995 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
1997 /* If we were only supposed to resume one thread, only wait for
1998 that thread - if it's still alive. If it died, however - which
1999 can happen if we're coming from the thread death case below -
2000 then we need to make sure we restart the other threads. We could
2001 pick a thread at random or restart all; restarting all is less
2004 && !ptid_equal (cont_thread
, null_ptid
)
2005 && !ptid_equal (cont_thread
, minus_one_ptid
))
2007 struct thread_info
*thread
;
2009 thread
= (struct thread_info
*) find_inferior_id (&all_threads
,
2012 /* No stepping, no signal - unless one is pending already, of course. */
2015 struct thread_resume resume_info
;
2016 resume_info
.thread
= minus_one_ptid
;
2017 resume_info
.kind
= resume_continue
;
2018 resume_info
.sig
= 0;
2019 linux_resume (&resume_info
, 1);
2025 if (ptid_equal (step_over_bkpt
, null_ptid
))
2026 pid
= linux_wait_for_event (ptid
, &w
, options
);
2030 fprintf (stderr
, "step_over_bkpt set [%s], doing a blocking wait\n",
2031 target_pid_to_str (step_over_bkpt
));
2032 pid
= linux_wait_for_event (step_over_bkpt
, &w
, options
& ~WNOHANG
);
2035 if (pid
== 0) /* only if TARGET_WNOHANG */
2038 event_child
= get_thread_lwp (current_inferior
);
2040 /* If we are waiting for a particular child, and it exited,
2041 linux_wait_for_event will return its exit status. Similarly if
2042 the last child exited. If this is not the last child, however,
2043 do not report it as exited until there is a 'thread exited' response
2044 available in the remote protocol. Instead, just wait for another event.
2045 This should be safe, because if the thread crashed we will already
2046 have reported the termination signal to GDB; that should stop any
2047 in-progress stepping operations, etc.
2049 Report the exit status of the last thread to exit. This matches
2050 LinuxThreads' behavior. */
2052 if (last_thread_of_process_p (current_inferior
))
2054 if (WIFEXITED (w
) || WIFSIGNALED (w
))
2058 ourstatus
->kind
= TARGET_WAITKIND_EXITED
;
2059 ourstatus
->value
.integer
= WEXITSTATUS (w
);
2062 fprintf (stderr
, "\nChild exited with retcode = %x \n", WEXITSTATUS (w
));
2066 ourstatus
->kind
= TARGET_WAITKIND_SIGNALLED
;
2067 ourstatus
->value
.sig
= target_signal_from_host (WTERMSIG (w
));
2070 fprintf (stderr
, "\nChild terminated with signal = %x \n", WTERMSIG (w
));
2074 return pid_to_ptid (pid
);
2079 if (!WIFSTOPPED (w
))
2083 /* If this event was not handled before, and is not a SIGTRAP, we
2084 report it. SIGILL and SIGSEGV are also treated as traps in case
2085 a breakpoint is inserted at the current PC. If this target does
2086 not support internal breakpoints at all, we also report the
2087 SIGTRAP without further processing; it's of no concern to us. */
2089 = (supports_breakpoints ()
2090 && (WSTOPSIG (w
) == SIGTRAP
2091 || ((WSTOPSIG (w
) == SIGILL
2092 || WSTOPSIG (w
) == SIGSEGV
)
2093 && (*the_low_target
.breakpoint_at
) (event_child
->stop_pc
))));
2095 if (maybe_internal_trap
)
2097 /* Handle anything that requires bookkeeping before deciding to
2098 report the event or continue waiting. */
2100 /* First check if we can explain the SIGTRAP with an internal
2101 breakpoint, or if we should possibly report the event to GDB.
2102 Do this before anything that may remove or insert a
2104 bp_explains_trap
= breakpoint_inserted_here (event_child
->stop_pc
);
2106 /* We have a SIGTRAP, possibly a step-over dance has just
2107 finished. If so, tweak the state machine accordingly,
2108 reinsert breakpoints and delete any reinsert (software
2109 single-step) breakpoints. */
2110 step_over_finished
= finish_step_over (event_child
);
2112 /* Now invoke the callbacks of any internal breakpoints there. */
2113 check_breakpoints (event_child
->stop_pc
);
2115 /* Handle tracepoint data collecting. This may overflow the
2116 trace buffer, and cause a tracing stop, removing
2118 trace_event
= handle_tracepoints (event_child
);
2120 if (bp_explains_trap
)
2122 /* If we stepped or ran into an internal breakpoint, we've
2123 already handled it. So next time we resume (from this
2124 PC), we should step over it. */
2126 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
2128 if (breakpoint_here (event_child
->stop_pc
))
2129 event_child
->need_step_over
= 1;
2134 /* We have some other signal, possibly a step-over dance was in
2135 progress, and it should be cancelled too. */
2136 step_over_finished
= finish_step_over (event_child
);
2139 /* We have all the data we need. Either report the event to GDB, or
2140 resume threads and keep waiting for more. */
2142 /* If we're collecting a fast tracepoint, finish the collection and
2143 move out of the jump pad before delivering a signal. See
2144 linux_stabilize_threads. */
2147 && WSTOPSIG (w
) != SIGTRAP
2148 && supports_fast_tracepoints ()
2149 && in_process_agent_loaded ())
2153 "Got signal %d for LWP %ld. Check if we need "
2154 "to defer or adjust it.\n",
2155 WSTOPSIG (w
), lwpid_of (event_child
));
2157 /* Allow debugging the jump pad itself. */
2158 if (current_inferior
->last_resume_kind
!= resume_step
2159 && maybe_move_out_of_jump_pad (event_child
, &w
))
2161 enqueue_one_deferred_signal (event_child
, &w
);
2165 "Signal %d for LWP %ld deferred (in jump pad)\n",
2166 WSTOPSIG (w
), lwpid_of (event_child
));
2168 linux_resume_one_lwp (event_child
, 0, 0, NULL
);
2173 if (event_child
->collecting_fast_tracepoint
)
2177 LWP %ld was trying to move out of the jump pad (%d). \
2178 Check if we're already there.\n",
2179 lwpid_of (event_child
),
2180 event_child
->collecting_fast_tracepoint
);
2184 event_child
->collecting_fast_tracepoint
2185 = linux_fast_tracepoint_collecting (event_child
, NULL
);
2187 if (event_child
->collecting_fast_tracepoint
!= 1)
2189 /* No longer need this breakpoint. */
2190 if (event_child
->exit_jump_pad_bkpt
!= NULL
)
2194 "No longer need exit-jump-pad bkpt; removing it."
2195 "stopping all threads momentarily.\n");
2197 /* Other running threads could hit this breakpoint.
2198 We don't handle moribund locations like GDB does,
2199 instead we always pause all threads when removing
2200 breakpoints, so that any step-over or
2201 decr_pc_after_break adjustment is always taken
2202 care of while the breakpoint is still
2204 stop_all_lwps (1, event_child
);
2205 cancel_breakpoints ();
2207 delete_breakpoint (event_child
->exit_jump_pad_bkpt
);
2208 event_child
->exit_jump_pad_bkpt
= NULL
;
2210 unstop_all_lwps (1, event_child
);
2212 gdb_assert (event_child
->suspended
>= 0);
2216 if (event_child
->collecting_fast_tracepoint
== 0)
2220 "fast tracepoint finished "
2221 "collecting successfully.\n");
2223 /* We may have a deferred signal to report. */
2224 if (dequeue_one_deferred_signal (event_child
, &w
))
2227 fprintf (stderr
, "dequeued one signal.\n");
2229 else if (debug_threads
)
2231 fprintf (stderr
, "no deferred signals.\n");
2233 if (stabilizing_threads
)
2235 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
2236 ourstatus
->value
.sig
= TARGET_SIGNAL_0
;
2237 return ptid_of (event_child
);
2243 /* Check whether GDB would be interested in this event. */
2245 /* If GDB is not interested in this signal, don't stop other
2246 threads, and don't report it to GDB. Just resume the inferior
2247 right away. We do this for threading-related signals as well as
2248 any that GDB specifically requested we ignore. But never ignore
2249 SIGSTOP if we sent it ourselves, and do not ignore signals when
2250 stepping - they may require special handling to skip the signal
2252 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
2255 && current_inferior
->last_resume_kind
!= resume_step
2257 #if defined (USE_THREAD_DB) && defined (__SIGRTMIN)
2258 (current_process ()->private->thread_db
!= NULL
2259 && (WSTOPSIG (w
) == __SIGRTMIN
2260 || WSTOPSIG (w
) == __SIGRTMIN
+ 1))
2263 (pass_signals
[target_signal_from_host (WSTOPSIG (w
))]
2264 && !(WSTOPSIG (w
) == SIGSTOP
2265 && current_inferior
->last_resume_kind
== resume_stop
))))
2267 siginfo_t info
, *info_p
;
2270 fprintf (stderr
, "Ignored signal %d for LWP %ld.\n",
2271 WSTOPSIG (w
), lwpid_of (event_child
));
2273 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (event_child
), 0, &info
) == 0)
2277 linux_resume_one_lwp (event_child
, event_child
->stepping
,
2278 WSTOPSIG (w
), info_p
);
2282 /* If GDB wanted this thread to single step, we always want to
2283 report the SIGTRAP, and let GDB handle it. Watchpoints should
2284 always be reported. So should signals we can't explain. A
2285 SIGTRAP we can't explain could be a GDB breakpoint --- we may or
2286 not support Z0 breakpoints. If we do, we're be able to handle
2287 GDB breakpoints on top of internal breakpoints, by handling the
2288 internal breakpoint and still reporting the event to GDB. If we
2289 don't, we're out of luck, GDB won't see the breakpoint hit. */
2290 report_to_gdb
= (!maybe_internal_trap
2291 || current_inferior
->last_resume_kind
== resume_step
2292 || event_child
->stopped_by_watchpoint
2293 || (!step_over_finished
&& !bp_explains_trap
&& !trace_event
)
2294 || gdb_breakpoint_here (event_child
->stop_pc
));
2296 /* We found no reason GDB would want us to stop. We either hit one
2297 of our own breakpoints, or finished an internal step GDB
2298 shouldn't know about. */
2303 if (bp_explains_trap
)
2304 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
2305 if (step_over_finished
)
2306 fprintf (stderr
, "Step-over finished.\n");
2308 fprintf (stderr
, "Tracepoint event.\n");
2311 /* We're not reporting this breakpoint to GDB, so apply the
2312 decr_pc_after_break adjustment to the inferior's regcache
2315 if (the_low_target
.set_pc
!= NULL
)
2317 struct regcache
*regcache
2318 = get_thread_regcache (get_lwp_thread (event_child
), 1);
2319 (*the_low_target
.set_pc
) (regcache
, event_child
->stop_pc
);
2322 /* We may have finished stepping over a breakpoint. If so,
2323 we've stopped and suspended all LWPs momentarily except the
2324 stepping one. This is where we resume them all again. We're
2325 going to keep waiting, so use proceed, which handles stepping
2326 over the next breakpoint. */
2328 fprintf (stderr
, "proceeding all threads.\n");
2330 if (step_over_finished
)
2331 unsuspend_all_lwps (event_child
);
2333 proceed_all_lwps ();
2339 if (current_inferior
->last_resume_kind
== resume_step
)
2340 fprintf (stderr
, "GDB wanted to single-step, reporting event.\n");
2341 if (event_child
->stopped_by_watchpoint
)
2342 fprintf (stderr
, "Stopped by watchpoint.\n");
2343 if (gdb_breakpoint_here (event_child
->stop_pc
))
2344 fprintf (stderr
, "Stopped by GDB breakpoint.\n");
2346 fprintf (stderr
, "Hit a non-gdbserver trap event.\n");
2349 /* Alright, we're going to report a stop. */
2351 if (!non_stop
&& !stabilizing_threads
)
2353 /* In all-stop, stop all threads. */
2354 stop_all_lwps (0, NULL
);
2356 /* If we're not waiting for a specific LWP, choose an event LWP
2357 from among those that have had events. Giving equal priority
2358 to all LWPs that have had events helps prevent
2360 if (ptid_equal (ptid
, minus_one_ptid
))
2362 event_child
->status_pending_p
= 1;
2363 event_child
->status_pending
= w
;
2365 select_event_lwp (&event_child
);
2367 event_child
->status_pending_p
= 0;
2368 w
= event_child
->status_pending
;
2371 /* Now that we've selected our final event LWP, cancel any
2372 breakpoints in other LWPs that have hit a GDB breakpoint.
2373 See the comment in cancel_breakpoints_callback to find out
2375 find_inferior (&all_lwps
, cancel_breakpoints_callback
, event_child
);
2377 /* Stabilize threads (move out of jump pads). */
2378 stabilize_threads ();
2382 /* If we just finished a step-over, then all threads had been
2383 momentarily paused. In all-stop, that's fine, we want
2384 threads stopped by now anyway. In non-stop, we need to
2385 re-resume threads that GDB wanted to be running. */
2386 if (step_over_finished
)
2387 unstop_all_lwps (1, event_child
);
2390 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
2392 /* Do this before the gdb_wants_all_stopped calls below, since they
2393 always set last_resume_kind to resume_stop. */
2394 if (current_inferior
->last_resume_kind
== resume_stop
2395 && WSTOPSIG (w
) == SIGSTOP
)
2397 /* A thread that has been requested to stop by GDB with vCont;t,
2398 and it stopped cleanly, so report as SIG0. The use of
2399 SIGSTOP is an implementation detail. */
2400 ourstatus
->value
.sig
= TARGET_SIGNAL_0
;
2402 else if (current_inferior
->last_resume_kind
== resume_stop
2403 && WSTOPSIG (w
) != SIGSTOP
)
2405 /* A thread that has been requested to stop by GDB with vCont;t,
2406 but, it stopped for other reasons. */
2407 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
2411 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
2414 gdb_assert (ptid_equal (step_over_bkpt
, null_ptid
));
2416 if (stabilizing_threads
)
2417 return ptid_of (event_child
);
2421 /* From GDB's perspective, all-stop mode always stops all
2422 threads implicitly. Tag all threads as "want-stopped". */
2423 gdb_wants_all_stopped ();
2427 /* We're reporting this LWP as stopped. Update it's
2428 "want-stopped" state to what the client wants, until it gets
2429 a new resume action. */
2430 gdb_wants_lwp_stopped (&event_child
->head
);
2434 fprintf (stderr
, "linux_wait ret = %s, %d, %d\n",
2435 target_pid_to_str (ptid_of (event_child
)),
2437 ourstatus
->value
.sig
);
2439 current_inferior
->last_status
= *ourstatus
;
2441 return ptid_of (event_child
);
2444 /* Get rid of any pending event in the pipe. */
2446 async_file_flush (void)
2452 ret
= read (linux_event_pipe
[0], &buf
, 1);
2453 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
2456 /* Put something in the pipe, so the event loop wakes up. */
2458 async_file_mark (void)
2462 async_file_flush ();
2465 ret
= write (linux_event_pipe
[1], "+", 1);
2466 while (ret
== 0 || (ret
== -1 && errno
== EINTR
));
2468 /* Ignore EAGAIN. If the pipe is full, the event loop will already
2469 be awakened anyway. */
2473 linux_wait (ptid_t ptid
,
2474 struct target_waitstatus
*ourstatus
, int target_options
)
2479 fprintf (stderr
, "linux_wait: [%s]\n", target_pid_to_str (ptid
));
2481 /* Flush the async file first. */
2482 if (target_is_async_p ())
2483 async_file_flush ();
2485 event_ptid
= linux_wait_1 (ptid
, ourstatus
, target_options
);
2487 /* If at least one stop was reported, there may be more. A single
2488 SIGCHLD can signal more than one child stop. */
2489 if (target_is_async_p ()
2490 && (target_options
& TARGET_WNOHANG
) != 0
2491 && !ptid_equal (event_ptid
, null_ptid
))
2497 /* Send a signal to an LWP. */
2500 kill_lwp (unsigned long lwpid
, int signo
)
2502 /* Use tkill, if possible, in case we are using nptl threads. If tkill
2503 fails, then we are not using nptl threads and we should be using kill. */
2507 static int tkill_failed
;
2514 ret
= syscall (__NR_tkill
, lwpid
, signo
);
2515 if (errno
!= ENOSYS
)
2522 return kill (lwpid
, signo
);
2526 send_sigstop (struct lwp_info
*lwp
)
2530 pid
= lwpid_of (lwp
);
2532 /* If we already have a pending stop signal for this process, don't
2534 if (lwp
->stop_expected
)
2537 fprintf (stderr
, "Have pending sigstop for lwp %d\n", pid
);
2543 fprintf (stderr
, "Sending sigstop to lwp %d\n", pid
);
2545 lwp
->stop_expected
= 1;
2546 kill_lwp (pid
, SIGSTOP
);
2550 send_sigstop_callback (struct inferior_list_entry
*entry
, void *except
)
2552 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2554 /* Ignore EXCEPT. */
2565 /* Increment the suspend count of an LWP, and stop it, if not stopped
2568 suspend_and_send_sigstop_callback (struct inferior_list_entry
*entry
,
2571 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2573 /* Ignore EXCEPT. */
2579 return send_sigstop_callback (entry
, except
);
2583 mark_lwp_dead (struct lwp_info
*lwp
, int wstat
)
2585 /* It's dead, really. */
2588 /* Store the exit status for later. */
2589 lwp
->status_pending_p
= 1;
2590 lwp
->status_pending
= wstat
;
2592 /* Prevent trying to stop it. */
2595 /* No further stops are expected from a dead lwp. */
2596 lwp
->stop_expected
= 0;
2600 wait_for_sigstop (struct inferior_list_entry
*entry
)
2602 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2603 struct thread_info
*saved_inferior
;
2612 fprintf (stderr
, "wait_for_sigstop: LWP %ld already stopped\n",
2617 saved_inferior
= current_inferior
;
2618 if (saved_inferior
!= NULL
)
2619 saved_tid
= ((struct inferior_list_entry
*) saved_inferior
)->id
;
2621 saved_tid
= null_ptid
; /* avoid bogus unused warning */
2623 ptid
= lwp
->head
.id
;
2626 fprintf (stderr
, "wait_for_sigstop: pulling one event\n");
2628 pid
= linux_wait_for_event (ptid
, &wstat
, __WALL
);
2630 /* If we stopped with a non-SIGSTOP signal, save it for later
2631 and record the pending SIGSTOP. If the process exited, just
2633 if (WIFSTOPPED (wstat
))
2636 fprintf (stderr
, "LWP %ld stopped with signal %d\n",
2637 lwpid_of (lwp
), WSTOPSIG (wstat
));
2639 if (WSTOPSIG (wstat
) != SIGSTOP
)
2642 fprintf (stderr
, "LWP %ld stopped with non-sigstop status %06x\n",
2643 lwpid_of (lwp
), wstat
);
2645 lwp
->status_pending_p
= 1;
2646 lwp
->status_pending
= wstat
;
2652 fprintf (stderr
, "Process %d exited while stopping LWPs\n", pid
);
2654 lwp
= find_lwp_pid (pid_to_ptid (pid
));
2657 /* Leave this status pending for the next time we're able to
2658 report it. In the mean time, we'll report this lwp as
2659 dead to GDB, so GDB doesn't try to read registers and
2660 memory from it. This can only happen if this was the
2661 last thread of the process; otherwise, PID is removed
2662 from the thread tables before linux_wait_for_event
2664 mark_lwp_dead (lwp
, wstat
);
2668 if (saved_inferior
== NULL
|| linux_thread_alive (saved_tid
))
2669 current_inferior
= saved_inferior
;
2673 fprintf (stderr
, "Previously current thread died.\n");
2677 /* We can't change the current inferior behind GDB's back,
2678 otherwise, a subsequent command may apply to the wrong
2680 current_inferior
= NULL
;
2684 /* Set a valid thread as current. */
2685 set_desired_inferior (0);
2690 /* Returns true if LWP ENTRY is stopped in a jump pad, and we can't
2691 move it out, because we need to report the stop event to GDB. For
2692 example, if the user puts a breakpoint in the jump pad, it's
2693 because she wants to debug it. */
2696 stuck_in_jump_pad_callback (struct inferior_list_entry
*entry
, void *data
)
2698 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2699 struct thread_info
*thread
= get_lwp_thread (lwp
);
2701 gdb_assert (lwp
->suspended
== 0);
2702 gdb_assert (lwp
->stopped
);
2704 /* Allow debugging the jump pad, gdb_collect, etc.. */
2705 return (supports_fast_tracepoints ()
2706 && in_process_agent_loaded ()
2707 && (gdb_breakpoint_here (lwp
->stop_pc
)
2708 || lwp
->stopped_by_watchpoint
2709 || thread
->last_resume_kind
== resume_step
)
2710 && linux_fast_tracepoint_collecting (lwp
, NULL
));
2714 move_out_of_jump_pad_callback (struct inferior_list_entry
*entry
)
2716 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2717 struct thread_info
*thread
= get_lwp_thread (lwp
);
2720 gdb_assert (lwp
->suspended
== 0);
2721 gdb_assert (lwp
->stopped
);
2723 wstat
= lwp
->status_pending_p
? &lwp
->status_pending
: NULL
;
2725 /* Allow debugging the jump pad, gdb_collect, etc. */
2726 if (!gdb_breakpoint_here (lwp
->stop_pc
)
2727 && !lwp
->stopped_by_watchpoint
2728 && thread
->last_resume_kind
!= resume_step
2729 && maybe_move_out_of_jump_pad (lwp
, wstat
))
2733 "LWP %ld needs stabilizing (in jump pad)\n",
2738 lwp
->status_pending_p
= 0;
2739 enqueue_one_deferred_signal (lwp
, wstat
);
2743 "Signal %d for LWP %ld deferred "
2745 WSTOPSIG (*wstat
), lwpid_of (lwp
));
2748 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
2755 lwp_running (struct inferior_list_entry
*entry
, void *data
)
2757 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2766 /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
2767 If SUSPEND, then also increase the suspend count of every LWP,
2771 stop_all_lwps (int suspend
, struct lwp_info
*except
)
2773 stopping_threads
= 1;
2776 find_inferior (&all_lwps
, suspend_and_send_sigstop_callback
, except
);
2778 find_inferior (&all_lwps
, send_sigstop_callback
, except
);
2779 for_each_inferior (&all_lwps
, wait_for_sigstop
);
2780 stopping_threads
= 0;
2783 /* Resume execution of the inferior process.
2784 If STEP is nonzero, single-step it.
2785 If SIGNAL is nonzero, give it that signal. */
2788 linux_resume_one_lwp (struct lwp_info
*lwp
,
2789 int step
, int signal
, siginfo_t
*info
)
2791 struct thread_info
*saved_inferior
;
2792 int fast_tp_collecting
;
2794 if (lwp
->stopped
== 0)
2797 fast_tp_collecting
= lwp
->collecting_fast_tracepoint
;
2799 gdb_assert (!stabilizing_threads
|| fast_tp_collecting
);
2801 /* Cancel actions that rely on GDB not changing the PC (e.g., the
2802 user used the "jump" command, or "set $pc = foo"). */
2803 if (lwp
->stop_pc
!= get_pc (lwp
))
2805 /* Collecting 'while-stepping' actions doesn't make sense
2807 release_while_stepping_state_list (get_lwp_thread (lwp
));
2810 /* If we have pending signals or status, and a new signal, enqueue the
2811 signal. Also enqueue the signal if we are waiting to reinsert a
2812 breakpoint; it will be picked up again below. */
2814 && (lwp
->status_pending_p
2815 || lwp
->pending_signals
!= NULL
2816 || lwp
->bp_reinsert
!= 0
2817 || fast_tp_collecting
))
2819 struct pending_signals
*p_sig
;
2820 p_sig
= xmalloc (sizeof (*p_sig
));
2821 p_sig
->prev
= lwp
->pending_signals
;
2822 p_sig
->signal
= signal
;
2824 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
2826 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
2827 lwp
->pending_signals
= p_sig
;
2830 if (lwp
->status_pending_p
)
2833 fprintf (stderr
, "Not resuming lwp %ld (%s, signal %d, stop %s);"
2834 " has pending status\n",
2835 lwpid_of (lwp
), step
? "step" : "continue", signal
,
2836 lwp
->stop_expected
? "expected" : "not expected");
2840 saved_inferior
= current_inferior
;
2841 current_inferior
= get_lwp_thread (lwp
);
2844 fprintf (stderr
, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
2845 lwpid_of (lwp
), step
? "step" : "continue", signal
,
2846 lwp
->stop_expected
? "expected" : "not expected");
2848 /* This bit needs some thinking about. If we get a signal that
2849 we must report while a single-step reinsert is still pending,
2850 we often end up resuming the thread. It might be better to
2851 (ew) allow a stack of pending events; then we could be sure that
2852 the reinsert happened right away and not lose any signals.
2854 Making this stack would also shrink the window in which breakpoints are
2855 uninserted (see comment in linux_wait_for_lwp) but not enough for
2856 complete correctness, so it won't solve that problem. It may be
2857 worthwhile just to solve this one, however. */
2858 if (lwp
->bp_reinsert
!= 0)
2861 fprintf (stderr
, " pending reinsert at 0x%s\n",
2862 paddress (lwp
->bp_reinsert
));
2864 if (lwp
->bp_reinsert
!= 0 && can_hardware_single_step ())
2866 if (fast_tp_collecting
== 0)
2869 fprintf (stderr
, "BAD - reinserting but not stepping.\n");
2871 fprintf (stderr
, "BAD - reinserting and suspended(%d).\n",
2878 /* Postpone any pending signal. It was enqueued above. */
2882 if (fast_tp_collecting
== 1)
2886 lwp %ld wants to get out of fast tracepoint jump pad (exit-jump-pad-bkpt)\n",
2889 /* Postpone any pending signal. It was enqueued above. */
2892 else if (fast_tp_collecting
== 2)
2896 lwp %ld wants to get out of fast tracepoint jump pad single-stepping\n",
2899 if (can_hardware_single_step ())
2902 fatal ("moving out of jump pad single-stepping"
2903 " not implemented on this target");
2905 /* Postpone any pending signal. It was enqueued above. */
2909 /* If we have while-stepping actions in this thread set it stepping.
2910 If we have a signal to deliver, it may or may not be set to
2911 SIG_IGN, we don't know. Assume so, and allow collecting
2912 while-stepping into a signal handler. A possible smart thing to
2913 do would be to set an internal breakpoint at the signal return
2914 address, continue, and carry on catching this while-stepping
2915 action only when that breakpoint is hit. A future
2917 if (get_lwp_thread (lwp
)->while_stepping
!= NULL
2918 && can_hardware_single_step ())
2922 "lwp %ld has a while-stepping action -> forcing step.\n",
2927 if (debug_threads
&& the_low_target
.get_pc
!= NULL
)
2929 struct regcache
*regcache
= get_thread_regcache (current_inferior
, 1);
2930 CORE_ADDR pc
= (*the_low_target
.get_pc
) (regcache
);
2931 fprintf (stderr
, " resuming from pc 0x%lx\n", (long) pc
);
2934 /* If we have pending signals, consume one unless we are trying to
2935 reinsert a breakpoint or we're trying to finish a fast tracepoint
2937 if (lwp
->pending_signals
!= NULL
2938 && lwp
->bp_reinsert
== 0
2939 && fast_tp_collecting
== 0)
2941 struct pending_signals
**p_sig
;
2943 p_sig
= &lwp
->pending_signals
;
2944 while ((*p_sig
)->prev
!= NULL
)
2945 p_sig
= &(*p_sig
)->prev
;
2947 signal
= (*p_sig
)->signal
;
2948 if ((*p_sig
)->info
.si_signo
!= 0)
2949 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &(*p_sig
)->info
);
2955 if (the_low_target
.prepare_to_resume
!= NULL
)
2956 the_low_target
.prepare_to_resume (lwp
);
2958 regcache_invalidate_one ((struct inferior_list_entry
*)
2959 get_lwp_thread (lwp
));
2962 lwp
->stopped_by_watchpoint
= 0;
2963 lwp
->stepping
= step
;
2964 ptrace (step
? PTRACE_SINGLESTEP
: PTRACE_CONT
, lwpid_of (lwp
), 0,
2965 /* Coerce to a uintptr_t first to avoid potential gcc warning
2966 of coercing an 8 byte integer to a 4 byte pointer. */
2967 (PTRACE_ARG4_TYPE
) (uintptr_t) signal
);
2969 current_inferior
= saved_inferior
;
2972 /* ESRCH from ptrace either means that the thread was already
2973 running (an error) or that it is gone (a race condition). If
2974 it's gone, we will get a notification the next time we wait,
2975 so we can ignore the error. We could differentiate these
2976 two, but it's tricky without waiting; the thread still exists
2977 as a zombie, so sending it signal 0 would succeed. So just
2982 perror_with_name ("ptrace");
2986 struct thread_resume_array
2988 struct thread_resume
*resume
;
2992 /* This function is called once per thread. We look up the thread
2993 in RESUME_PTR, and mark the thread with a pointer to the appropriate
2996 This algorithm is O(threads * resume elements), but resume elements
2997 is small (and will remain small at least until GDB supports thread
3000 linux_set_resume_request (struct inferior_list_entry
*entry
, void *arg
)
3002 struct lwp_info
*lwp
;
3003 struct thread_info
*thread
;
3005 struct thread_resume_array
*r
;
3007 thread
= (struct thread_info
*) entry
;
3008 lwp
= get_thread_lwp (thread
);
3011 for (ndx
= 0; ndx
< r
->n
; ndx
++)
3013 ptid_t ptid
= r
->resume
[ndx
].thread
;
3014 if (ptid_equal (ptid
, minus_one_ptid
)
3015 || ptid_equal (ptid
, entry
->id
)
3016 || (ptid_is_pid (ptid
)
3017 && (ptid_get_pid (ptid
) == pid_of (lwp
)))
3018 || (ptid_get_lwp (ptid
) == -1
3019 && (ptid_get_pid (ptid
) == pid_of (lwp
))))
3021 if (r
->resume
[ndx
].kind
== resume_stop
3022 && thread
->last_resume_kind
== resume_stop
)
3025 fprintf (stderr
, "already %s LWP %ld at GDB's request\n",
3026 thread
->last_status
.kind
== TARGET_WAITKIND_STOPPED
3034 lwp
->resume
= &r
->resume
[ndx
];
3035 thread
->last_resume_kind
= lwp
->resume
->kind
;
3037 /* If we had a deferred signal to report, dequeue one now.
3038 This can happen if LWP gets more than one signal while
3039 trying to get out of a jump pad. */
3041 && !lwp
->status_pending_p
3042 && dequeue_one_deferred_signal (lwp
, &lwp
->status_pending
))
3044 lwp
->status_pending_p
= 1;
3048 "Dequeueing deferred signal %d for LWP %ld, "
3049 "leaving status pending.\n",
3050 WSTOPSIG (lwp
->status_pending
), lwpid_of (lwp
));
3057 /* No resume action for this thread. */
3064 /* Set *FLAG_P if this lwp has an interesting status pending. */
3066 resume_status_pending_p (struct inferior_list_entry
*entry
, void *flag_p
)
3068 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
3070 /* LWPs which will not be resumed are not interesting, because
3071 we might not wait for them next time through linux_wait. */
3072 if (lwp
->resume
== NULL
)
3075 if (lwp
->status_pending_p
)
3076 * (int *) flag_p
= 1;
3081 /* Return 1 if this lwp that GDB wants running is stopped at an
3082 internal breakpoint that we need to step over. It assumes that any
3083 required STOP_PC adjustment has already been propagated to the
3084 inferior's regcache. */
3087 need_step_over_p (struct inferior_list_entry
*entry
, void *dummy
)
3089 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
3090 struct thread_info
*thread
;
3091 struct thread_info
*saved_inferior
;
3094 /* LWPs which will not be resumed are not interesting, because we
3095 might not wait for them next time through linux_wait. */
3101 "Need step over [LWP %ld]? Ignoring, not stopped\n",
3106 thread
= get_lwp_thread (lwp
);
3108 if (thread
->last_resume_kind
== resume_stop
)
3112 "Need step over [LWP %ld]? Ignoring, should remain stopped\n",
3117 gdb_assert (lwp
->suspended
>= 0);
3123 "Need step over [LWP %ld]? Ignoring, suspended\n",
3128 if (!lwp
->need_step_over
)
3132 "Need step over [LWP %ld]? No\n", lwpid_of (lwp
));
3135 if (lwp
->status_pending_p
)
3139 "Need step over [LWP %ld]? Ignoring, has pending status.\n",
3144 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
3148 /* If the PC has changed since we stopped, then don't do anything,
3149 and let the breakpoint/tracepoint be hit. This happens if, for
3150 instance, GDB handled the decr_pc_after_break subtraction itself,
3151 GDB is OOL stepping this thread, or the user has issued a "jump"
3152 command, or poked thread's registers herself. */
3153 if (pc
!= lwp
->stop_pc
)
3157 "Need step over [LWP %ld]? Cancelling, PC was changed. "
3158 "Old stop_pc was 0x%s, PC is now 0x%s\n",
3159 lwpid_of (lwp
), paddress (lwp
->stop_pc
), paddress (pc
));
3161 lwp
->need_step_over
= 0;
3165 saved_inferior
= current_inferior
;
3166 current_inferior
= thread
;
3168 /* We can only step over breakpoints we know about. */
3169 if (breakpoint_here (pc
) || fast_tracepoint_jump_here (pc
))
3171 /* Don't step over a breakpoint that GDB expects to hit
3173 if (gdb_breakpoint_here (pc
))
3177 "Need step over [LWP %ld]? yes, but found"
3178 " GDB breakpoint at 0x%s; skipping step over\n",
3179 lwpid_of (lwp
), paddress (pc
));
3181 current_inferior
= saved_inferior
;
3188 "Need step over [LWP %ld]? yes, found breakpoint at 0x%s\n",
3189 lwpid_of (lwp
), paddress (pc
));
3191 /* We've found an lwp that needs stepping over --- return 1 so
3192 that find_inferior stops looking. */
3193 current_inferior
= saved_inferior
;
3195 /* If the step over is cancelled, this is set again. */
3196 lwp
->need_step_over
= 0;
3201 current_inferior
= saved_inferior
;
3205 "Need step over [LWP %ld]? No, no breakpoint found at 0x%s\n",
3206 lwpid_of (lwp
), paddress (pc
));
3211 /* Start a step-over operation on LWP. When LWP stopped at a
3212 breakpoint, to make progress, we need to remove the breakpoint out
3213 of the way. If we let other threads run while we do that, they may
3214 pass by the breakpoint location and miss hitting it. To avoid
3215 that, a step-over momentarily stops all threads while LWP is
3216 single-stepped while the breakpoint is temporarily uninserted from
3217 the inferior. When the single-step finishes, we reinsert the
3218 breakpoint, and let all threads that are supposed to be running,
3221 On targets that don't support hardware single-step, we don't
3222 currently support full software single-stepping. Instead, we only
3223 support stepping over the thread event breakpoint, by asking the
3224 low target where to place a reinsert breakpoint. Since this
3225 routine assumes the breakpoint being stepped over is a thread event
3226 breakpoint, it usually assumes the return address of the current
3227 function is a good enough place to set the reinsert breakpoint. */
3230 start_step_over (struct lwp_info
*lwp
)
3232 struct thread_info
*saved_inferior
;
3238 "Starting step-over on LWP %ld. Stopping all threads\n",
3241 stop_all_lwps (1, lwp
);
3242 gdb_assert (lwp
->suspended
== 0);
3245 fprintf (stderr
, "Done stopping all threads for step-over.\n");
3247 /* Note, we should always reach here with an already adjusted PC,
3248 either by GDB (if we're resuming due to GDB's request), or by our
3249 caller, if we just finished handling an internal breakpoint GDB
3250 shouldn't care about. */
3253 saved_inferior
= current_inferior
;
3254 current_inferior
= get_lwp_thread (lwp
);
3256 lwp
->bp_reinsert
= pc
;
3257 uninsert_breakpoints_at (pc
);
3258 uninsert_fast_tracepoint_jumps_at (pc
);
3260 if (can_hardware_single_step ())
3266 CORE_ADDR raddr
= (*the_low_target
.breakpoint_reinsert_addr
) ();
3267 set_reinsert_breakpoint (raddr
);
3271 current_inferior
= saved_inferior
;
3273 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
3275 /* Require next event from this LWP. */
3276 step_over_bkpt
= lwp
->head
.id
;
3280 /* Finish a step-over. Reinsert the breakpoint we had uninserted in
3281 start_step_over, if still there, and delete any reinsert
3282 breakpoints we've set, on non hardware single-step targets. */
3285 finish_step_over (struct lwp_info
*lwp
)
3287 if (lwp
->bp_reinsert
!= 0)
3290 fprintf (stderr
, "Finished step over.\n");
3292 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
3293 may be no breakpoint to reinsert there by now. */
3294 reinsert_breakpoints_at (lwp
->bp_reinsert
);
3295 reinsert_fast_tracepoint_jumps_at (lwp
->bp_reinsert
);
3297 lwp
->bp_reinsert
= 0;
3299 /* Delete any software-single-step reinsert breakpoints. No
3300 longer needed. We don't have to worry about other threads
3301 hitting this trap, and later not being able to explain it,
3302 because we were stepping over a breakpoint, and we hold all
3303 threads but LWP stopped while doing that. */
3304 if (!can_hardware_single_step ())
3305 delete_reinsert_breakpoints ();
3307 step_over_bkpt
= null_ptid
;
3314 /* This function is called once per thread. We check the thread's resume
3315 request, which will tell us whether to resume, step, or leave the thread
3316 stopped; and what signal, if any, it should be sent.
3318 For threads which we aren't explicitly told otherwise, we preserve
3319 the stepping flag; this is used for stepping over gdbserver-placed
3322 If pending_flags was set in any thread, we queue any needed
3323 signals, since we won't actually resume. We already have a pending
3324 event to report, so we don't need to preserve any step requests;
3325 they should be re-issued if necessary. */
3328 linux_resume_one_thread (struct inferior_list_entry
*entry
, void *arg
)
3330 struct lwp_info
*lwp
;
3331 struct thread_info
*thread
;
3333 int leave_all_stopped
= * (int *) arg
;
3336 thread
= (struct thread_info
*) entry
;
3337 lwp
= get_thread_lwp (thread
);
3339 if (lwp
->resume
== NULL
)
3342 if (lwp
->resume
->kind
== resume_stop
)
3345 fprintf (stderr
, "resume_stop request for LWP %ld\n", lwpid_of (lwp
));
3350 fprintf (stderr
, "stopping LWP %ld\n", lwpid_of (lwp
));
3352 /* Stop the thread, and wait for the event asynchronously,
3353 through the event loop. */
3359 fprintf (stderr
, "already stopped LWP %ld\n",
3362 /* The LWP may have been stopped in an internal event that
3363 was not meant to be notified back to GDB (e.g., gdbserver
3364 breakpoint), so we should be reporting a stop event in
3367 /* If the thread already has a pending SIGSTOP, this is a
3368 no-op. Otherwise, something later will presumably resume
3369 the thread and this will cause it to cancel any pending
3370 operation, due to last_resume_kind == resume_stop. If
3371 the thread already has a pending status to report, we
3372 will still report it the next time we wait - see
3373 status_pending_p_callback. */
3377 /* For stop requests, we're done. */
3379 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
3383 /* If this thread which is about to be resumed has a pending status,
3384 then don't resume any threads - we can just report the pending
3385 status. Make sure to queue any signals that would otherwise be
3386 sent. In all-stop mode, we do this decision based on if *any*
3387 thread has a pending status. If there's a thread that needs the
3388 step-over-breakpoint dance, then don't resume any other thread
3389 but that particular one. */
3390 leave_pending
= (lwp
->status_pending_p
|| leave_all_stopped
);
3395 fprintf (stderr
, "resuming LWP %ld\n", lwpid_of (lwp
));
3397 step
= (lwp
->resume
->kind
== resume_step
);
3398 linux_resume_one_lwp (lwp
, step
, lwp
->resume
->sig
, NULL
);
3403 fprintf (stderr
, "leaving LWP %ld stopped\n", lwpid_of (lwp
));
3405 /* If we have a new signal, enqueue the signal. */
3406 if (lwp
->resume
->sig
!= 0)
3408 struct pending_signals
*p_sig
;
3409 p_sig
= xmalloc (sizeof (*p_sig
));
3410 p_sig
->prev
= lwp
->pending_signals
;
3411 p_sig
->signal
= lwp
->resume
->sig
;
3412 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
3414 /* If this is the same signal we were previously stopped by,
3415 make sure to queue its siginfo. We can ignore the return
3416 value of ptrace; if it fails, we'll skip
3417 PTRACE_SETSIGINFO. */
3418 if (WIFSTOPPED (lwp
->last_status
)
3419 && WSTOPSIG (lwp
->last_status
) == lwp
->resume
->sig
)
3420 ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &p_sig
->info
);
3422 lwp
->pending_signals
= p_sig
;
3426 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
3432 linux_resume (struct thread_resume
*resume_info
, size_t n
)
3434 struct thread_resume_array array
= { resume_info
, n
};
3435 struct lwp_info
*need_step_over
= NULL
;
3437 int leave_all_stopped
;
3439 find_inferior (&all_threads
, linux_set_resume_request
, &array
);
3441 /* If there is a thread which would otherwise be resumed, which has
3442 a pending status, then don't resume any threads - we can just
3443 report the pending status. Make sure to queue any signals that
3444 would otherwise be sent. In non-stop mode, we'll apply this
3445 logic to each thread individually. We consume all pending events
3446 before considering to start a step-over (in all-stop). */
3449 find_inferior (&all_lwps
, resume_status_pending_p
, &any_pending
);
3451 /* If there is a thread which would otherwise be resumed, which is
3452 stopped at a breakpoint that needs stepping over, then don't
3453 resume any threads - have it step over the breakpoint with all
3454 other threads stopped, then resume all threads again. Make sure
3455 to queue any signals that would otherwise be delivered or
3457 if (!any_pending
&& supports_breakpoints ())
3459 = (struct lwp_info
*) find_inferior (&all_lwps
,
3460 need_step_over_p
, NULL
);
3462 leave_all_stopped
= (need_step_over
!= NULL
|| any_pending
);
3466 if (need_step_over
!= NULL
)
3467 fprintf (stderr
, "Not resuming all, need step over\n");
3468 else if (any_pending
)
3470 "Not resuming, all-stop and found "
3471 "an LWP with pending status\n");
3473 fprintf (stderr
, "Resuming, no pending status or step over needed\n");
3476 /* Even if we're leaving threads stopped, queue all signals we'd
3477 otherwise deliver. */
3478 find_inferior (&all_threads
, linux_resume_one_thread
, &leave_all_stopped
);
3481 start_step_over (need_step_over
);
3484 /* This function is called once per thread. We check the thread's
3485 last resume request, which will tell us whether to resume, step, or
3486 leave the thread stopped. Any signal the client requested to be
3487 delivered has already been enqueued at this point.
3489 If any thread that GDB wants running is stopped at an internal
3490 breakpoint that needs stepping over, we start a step-over operation
3491 on that particular thread, and leave all others stopped. */
3494 proceed_one_lwp (struct inferior_list_entry
*entry
, void *except
)
3496 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
3497 struct thread_info
*thread
;
3505 "proceed_one_lwp: lwp %ld\n", lwpid_of (lwp
));
3510 fprintf (stderr
, " LWP %ld already running\n", lwpid_of (lwp
));
3514 thread
= get_lwp_thread (lwp
);
3516 if (thread
->last_resume_kind
== resume_stop
3517 && thread
->last_status
.kind
!= TARGET_WAITKIND_IGNORE
)
3520 fprintf (stderr
, " client wants LWP to remain %ld stopped\n",
3525 if (lwp
->status_pending_p
)
3528 fprintf (stderr
, " LWP %ld has pending status, leaving stopped\n",
3533 gdb_assert (lwp
->suspended
>= 0);
3538 fprintf (stderr
, " LWP %ld is suspended\n", lwpid_of (lwp
));
3542 if (thread
->last_resume_kind
== resume_stop
)
3544 /* We haven't reported this LWP as stopped yet (otherwise, the
3545 last_status.kind check above would catch it, and we wouldn't
3546 reach here. This LWP may have been momentarily paused by a
3547 stop_all_lwps call while handling for example, another LWP's
3548 step-over. In that case, the pending expected SIGSTOP signal
3549 that was queued at vCont;t handling time will have already
3550 been consumed by wait_for_sigstop, and so we need to requeue
3551 another one here. Note that if the LWP already has a SIGSTOP
3552 pending, this is a no-op. */
3556 "Client wants LWP %ld to stop. "
3557 "Making sure it has a SIGSTOP pending\n",
3563 step
= thread
->last_resume_kind
== resume_step
;
3564 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
3569 unsuspend_and_proceed_one_lwp (struct inferior_list_entry
*entry
, void *except
)
3571 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
3577 gdb_assert (lwp
->suspended
>= 0);
3579 return proceed_one_lwp (entry
, except
);
3582 /* When we finish a step-over, set threads running again. If there's
3583 another thread that may need a step-over, now's the time to start
3584 it. Eventually, we'll move all threads past their breakpoints. */
3587 proceed_all_lwps (void)
3589 struct lwp_info
*need_step_over
;
3591 /* If there is a thread which would otherwise be resumed, which is
3592 stopped at a breakpoint that needs stepping over, then don't
3593 resume any threads - have it step over the breakpoint with all
3594 other threads stopped, then resume all threads again. */
3596 if (supports_breakpoints ())
3599 = (struct lwp_info
*) find_inferior (&all_lwps
,
3600 need_step_over_p
, NULL
);
3602 if (need_step_over
!= NULL
)
3605 fprintf (stderr
, "proceed_all_lwps: found "
3606 "thread %ld needing a step-over\n",
3607 lwpid_of (need_step_over
));
3609 start_step_over (need_step_over
);
3615 fprintf (stderr
, "Proceeding, no step-over needed\n");
3617 find_inferior (&all_lwps
, proceed_one_lwp
, NULL
);
3620 /* Stopped LWPs that the client wanted to be running, that don't have
3621 pending statuses, are set to run again, except for EXCEPT, if not
3622 NULL. This undoes a stop_all_lwps call. */
3625 unstop_all_lwps (int unsuspend
, struct lwp_info
*except
)
3631 "unstopping all lwps, except=(LWP %ld)\n", lwpid_of (except
));
3634 "unstopping all lwps\n");
3638 find_inferior (&all_lwps
, unsuspend_and_proceed_one_lwp
, except
);
3640 find_inferior (&all_lwps
, proceed_one_lwp
, except
);
3643 #ifdef HAVE_LINUX_USRREGS
3646 register_addr (int regnum
)
3650 if (regnum
< 0 || regnum
>= the_low_target
.num_regs
)
3651 error ("Invalid register number %d.", regnum
);
3653 addr
= the_low_target
.regmap
[regnum
];
3658 /* Fetch one register. */
3660 fetch_register (struct regcache
*regcache
, int regno
)
3667 if (regno
>= the_low_target
.num_regs
)
3669 if ((*the_low_target
.cannot_fetch_register
) (regno
))
3672 regaddr
= register_addr (regno
);
3676 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3677 size
= ((register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
3678 & - sizeof (PTRACE_XFER_TYPE
));
3679 buf
= alloca (size
);
3680 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
3683 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
3684 ptrace (PTRACE_PEEKUSER
, pid
,
3685 /* Coerce to a uintptr_t first to avoid potential gcc warning
3686 of coercing an 8 byte integer to a 4 byte pointer. */
3687 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
, 0);
3688 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
3690 error ("reading register %d: %s", regno
, strerror (errno
));
3693 if (the_low_target
.supply_ptrace_register
)
3694 the_low_target
.supply_ptrace_register (regcache
, regno
, buf
);
3696 supply_register (regcache
, regno
, buf
);
3699 /* Fetch all registers, or just one, from the child process. */
3701 usr_fetch_inferior_registers (struct regcache
*regcache
, int regno
)
3704 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
3705 fetch_register (regcache
, regno
);
3707 fetch_register (regcache
, regno
);
3710 /* Store our register values back into the inferior.
3711 If REGNO is -1, do this for all registers.
3712 Otherwise, REGNO specifies which register (so we can save time). */
3714 usr_store_inferior_registers (struct regcache
*regcache
, int regno
)
3723 if (regno
>= the_low_target
.num_regs
)
3726 if ((*the_low_target
.cannot_store_register
) (regno
) == 1)
3729 regaddr
= register_addr (regno
);
3733 size
= (register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
3734 & - sizeof (PTRACE_XFER_TYPE
);
3735 buf
= alloca (size
);
3736 memset (buf
, 0, size
);
3738 if (the_low_target
.collect_ptrace_register
)
3739 the_low_target
.collect_ptrace_register (regcache
, regno
, buf
);
3741 collect_register (regcache
, regno
, buf
);
3743 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3744 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
3747 ptrace (PTRACE_POKEUSER
, pid
,
3748 /* Coerce to a uintptr_t first to avoid potential gcc warning
3749 about coercing an 8 byte integer to a 4 byte pointer. */
3750 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
,
3751 (PTRACE_ARG4_TYPE
) *(PTRACE_XFER_TYPE
*) (buf
+ i
));
3754 /* At this point, ESRCH should mean the process is
3755 already gone, in which case we simply ignore attempts
3756 to change its registers. See also the related
3757 comment in linux_resume_one_lwp. */
3761 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
3762 error ("writing register %d: %s", regno
, strerror (errno
));
3764 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
3768 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
3769 usr_store_inferior_registers (regcache
, regno
);
3771 #endif /* HAVE_LINUX_USRREGS */
3775 #ifdef HAVE_LINUX_REGSETS
3778 regsets_fetch_inferior_registers (struct regcache
*regcache
)
3780 struct regset_info
*regset
;
3781 int saw_general_regs
= 0;
3785 regset
= target_regsets
;
3787 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3788 while (regset
->size
>= 0)
3793 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
3799 buf
= xmalloc (regset
->size
);
3801 nt_type
= regset
->nt_type
;
3805 iov
.iov_len
= regset
->size
;
3806 data
= (void *) &iov
;
3812 res
= ptrace (regset
->get_request
, pid
, nt_type
, data
);
3814 res
= ptrace (regset
->get_request
, pid
, data
, nt_type
);
3820 /* If we get EIO on a regset, do not try it again for
3822 disabled_regsets
[regset
- target_regsets
] = 1;
3829 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%d",
3834 else if (regset
->type
== GENERAL_REGS
)
3835 saw_general_regs
= 1;
3836 regset
->store_function (regcache
, buf
);
3840 if (saw_general_regs
)
3847 regsets_store_inferior_registers (struct regcache
*regcache
)
3849 struct regset_info
*regset
;
3850 int saw_general_regs
= 0;
3854 regset
= target_regsets
;
3856 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3857 while (regset
->size
>= 0)
3862 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
3868 buf
= xmalloc (regset
->size
);
3870 /* First fill the buffer with the current register set contents,
3871 in case there are any items in the kernel's regset that are
3872 not in gdbserver's regcache. */
3874 nt_type
= regset
->nt_type
;
3878 iov
.iov_len
= regset
->size
;
3879 data
= (void *) &iov
;
3885 res
= ptrace (regset
->get_request
, pid
, nt_type
, data
);
3887 res
= ptrace (regset
->get_request
, pid
, &iov
, data
);
3892 /* Then overlay our cached registers on that. */
3893 regset
->fill_function (regcache
, buf
);
3895 /* Only now do we write the register set. */
3897 res
= ptrace (regset
->set_request
, pid
, nt_type
, data
);
3899 res
= ptrace (regset
->set_request
, pid
, data
, nt_type
);
3907 /* If we get EIO on a regset, do not try it again for
3909 disabled_regsets
[regset
- target_regsets
] = 1;
3913 else if (errno
== ESRCH
)
3915 /* At this point, ESRCH should mean the process is
3916 already gone, in which case we simply ignore attempts
3917 to change its registers. See also the related
3918 comment in linux_resume_one_lwp. */
3924 perror ("Warning: ptrace(regsets_store_inferior_registers)");
3927 else if (regset
->type
== GENERAL_REGS
)
3928 saw_general_regs
= 1;
3932 if (saw_general_regs
)
3939 #endif /* HAVE_LINUX_REGSETS */
3943 linux_fetch_registers (struct regcache
*regcache
, int regno
)
3945 #ifdef HAVE_LINUX_REGSETS
3946 if (regsets_fetch_inferior_registers (regcache
) == 0)
3949 #ifdef HAVE_LINUX_USRREGS
3950 usr_fetch_inferior_registers (regcache
, regno
);
3955 linux_store_registers (struct regcache
*regcache
, int regno
)
3957 #ifdef HAVE_LINUX_REGSETS
3958 if (regsets_store_inferior_registers (regcache
) == 0)
3961 #ifdef HAVE_LINUX_USRREGS
3962 usr_store_inferior_registers (regcache
, regno
);
3967 /* Copy LEN bytes from inferior's memory starting at MEMADDR
3968 to debugger memory starting at MYADDR. */
3971 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
3974 /* Round starting address down to longword boundary. */
3975 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
3976 /* Round ending address up; get number of longwords that makes. */
3978 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
3979 / sizeof (PTRACE_XFER_TYPE
);
3980 /* Allocate buffer of that many longwords. */
3981 register PTRACE_XFER_TYPE
*buffer
3982 = (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
3985 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3987 /* Try using /proc. Don't bother for one word. */
3988 if (len
>= 3 * sizeof (long))
3990 /* We could keep this file open and cache it - possibly one per
3991 thread. That requires some juggling, but is even faster. */
3992 sprintf (filename
, "/proc/%d/mem", pid
);
3993 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
3997 /* If pread64 is available, use it. It's faster if the kernel
3998 supports it (only one syscall), and it's 64-bit safe even on
3999 32-bit platforms (for instance, SPARC debugging a SPARC64
4002 if (pread64 (fd
, myaddr
, len
, memaddr
) != len
)
4004 if (lseek (fd
, memaddr
, SEEK_SET
) == -1 || read (fd
, myaddr
, len
) != len
)
4016 /* Read all the longwords */
4017 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
4020 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
4021 about coercing an 8 byte integer to a 4 byte pointer. */
4022 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, pid
,
4023 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
4028 /* Copy appropriate bytes out of the buffer. */
4030 (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
4036 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
4037 memory at MEMADDR. On failure (cannot write to the inferior)
4038 returns the value of errno. */
4041 linux_write_memory (CORE_ADDR memaddr
, const unsigned char *myaddr
, int len
)
4044 /* Round starting address down to longword boundary. */
4045 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
4046 /* Round ending address up; get number of longwords that makes. */
4048 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1) / sizeof (PTRACE_XFER_TYPE
);
4049 /* Allocate buffer of that many longwords. */
4050 register PTRACE_XFER_TYPE
*buffer
= (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
4051 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
4055 /* Dump up to four bytes. */
4056 unsigned int val
= * (unsigned int *) myaddr
;
4062 val
= val
& 0xffffff;
4063 fprintf (stderr
, "Writing %0*x to 0x%08lx\n", 2 * ((len
< 4) ? len
: 4),
4064 val
, (long)memaddr
);
4067 /* Fill start and end extra bytes of buffer with existing memory data. */
4070 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
4071 about coercing an 8 byte integer to a 4 byte pointer. */
4072 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, pid
,
4073 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
4081 = ptrace (PTRACE_PEEKTEXT
, pid
,
4082 /* Coerce to a uintptr_t first to avoid potential gcc warning
4083 about coercing an 8 byte integer to a 4 byte pointer. */
4084 (PTRACE_ARG3_TYPE
) (uintptr_t) (addr
+ (count
- 1)
4085 * sizeof (PTRACE_XFER_TYPE
)),
4091 /* Copy data to be written over corresponding part of buffer. */
4093 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)), myaddr
, len
);
4095 /* Write the entire buffer. */
4097 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
4100 ptrace (PTRACE_POKETEXT
, pid
,
4101 /* Coerce to a uintptr_t first to avoid potential gcc warning
4102 about coercing an 8 byte integer to a 4 byte pointer. */
4103 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
,
4104 (PTRACE_ARG4_TYPE
) buffer
[i
]);
4112 /* Non-zero if the kernel supports PTRACE_O_TRACEFORK. */
4113 static int linux_supports_tracefork_flag
;
4116 linux_enable_event_reporting (int pid
)
4118 if (!linux_supports_tracefork_flag
)
4121 ptrace (PTRACE_SETOPTIONS
, pid
, 0, (PTRACE_ARG4_TYPE
) PTRACE_O_TRACECLONE
);
4124 /* Helper functions for linux_test_for_tracefork, called via clone (). */
4127 linux_tracefork_grandchild (void *arg
)
4132 #define STACK_SIZE 4096
4135 linux_tracefork_child (void *arg
)
4137 ptrace (PTRACE_TRACEME
, 0, 0, 0);
4138 kill (getpid (), SIGSTOP
);
4140 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
4143 linux_tracefork_grandchild (NULL
);
4145 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4148 __clone2 (linux_tracefork_grandchild
, arg
, STACK_SIZE
,
4149 CLONE_VM
| SIGCHLD
, NULL
);
4151 clone (linux_tracefork_grandchild
, arg
+ STACK_SIZE
,
4152 CLONE_VM
| SIGCHLD
, NULL
);
4155 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4160 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
4161 sure that we can enable the option, and that it had the desired
4165 linux_test_for_tracefork (void)
4167 int child_pid
, ret
, status
;
4169 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4170 char *stack
= xmalloc (STACK_SIZE
* 4);
4171 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4173 linux_supports_tracefork_flag
= 0;
4175 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
4177 child_pid
= fork ();
4179 linux_tracefork_child (NULL
);
4181 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4183 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
4185 child_pid
= __clone2 (linux_tracefork_child
, stack
, STACK_SIZE
,
4186 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
4187 #else /* !__ia64__ */
4188 child_pid
= clone (linux_tracefork_child
, stack
+ STACK_SIZE
,
4189 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
4190 #endif /* !__ia64__ */
4192 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4194 if (child_pid
== -1)
4195 perror_with_name ("clone");
4197 ret
= my_waitpid (child_pid
, &status
, 0);
4199 perror_with_name ("waitpid");
4200 else if (ret
!= child_pid
)
4201 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret
);
4202 if (! WIFSTOPPED (status
))
4203 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status
);
4205 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0,
4206 (PTRACE_ARG4_TYPE
) PTRACE_O_TRACEFORK
);
4209 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
4212 warning ("linux_test_for_tracefork: failed to kill child");
4216 ret
= my_waitpid (child_pid
, &status
, 0);
4217 if (ret
!= child_pid
)
4218 warning ("linux_test_for_tracefork: failed to wait for killed child");
4219 else if (!WIFSIGNALED (status
))
4220 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
4221 "killed child", status
);
4226 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
4228 warning ("linux_test_for_tracefork: failed to resume child");
4230 ret
= my_waitpid (child_pid
, &status
, 0);
4232 if (ret
== child_pid
&& WIFSTOPPED (status
)
4233 && status
>> 16 == PTRACE_EVENT_FORK
)
4236 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
4237 if (ret
== 0 && second_pid
!= 0)
4241 linux_supports_tracefork_flag
= 1;
4242 my_waitpid (second_pid
, &second_status
, 0);
4243 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
4245 warning ("linux_test_for_tracefork: failed to kill second child");
4246 my_waitpid (second_pid
, &status
, 0);
4250 warning ("linux_test_for_tracefork: unexpected result from waitpid "
4251 "(%d, status 0x%x)", ret
, status
);
4255 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
4257 warning ("linux_test_for_tracefork: failed to kill child");
4258 my_waitpid (child_pid
, &status
, 0);
4260 while (WIFSTOPPED (status
));
4262 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4264 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4269 linux_look_up_symbols (void)
4271 #ifdef USE_THREAD_DB
4272 struct process_info
*proc
= current_process ();
4274 if (proc
->private->thread_db
!= NULL
)
4277 /* If the kernel supports tracing forks then it also supports tracing
4278 clones, and then we don't need to use the magic thread event breakpoint
4279 to learn about threads. */
4280 thread_db_init (!linux_supports_tracefork_flag
);
4285 linux_request_interrupt (void)
4287 extern unsigned long signal_pid
;
4289 if (!ptid_equal (cont_thread
, null_ptid
)
4290 && !ptid_equal (cont_thread
, minus_one_ptid
))
4292 struct lwp_info
*lwp
;
4295 lwp
= get_thread_lwp (current_inferior
);
4296 lwpid
= lwpid_of (lwp
);
4297 kill_lwp (lwpid
, SIGINT
);
4300 kill_lwp (signal_pid
, SIGINT
);
4303 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
4304 to debugger memory starting at MYADDR. */
4307 linux_read_auxv (CORE_ADDR offset
, unsigned char *myaddr
, unsigned int len
)
4309 char filename
[PATH_MAX
];
4311 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
4313 snprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
4315 fd
= open (filename
, O_RDONLY
);
4319 if (offset
!= (CORE_ADDR
) 0
4320 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4323 n
= read (fd
, myaddr
, len
);
4330 /* These breakpoint and watchpoint related wrapper functions simply
4331 pass on the function call if the target has registered a
4332 corresponding function. */
4335 linux_insert_point (char type
, CORE_ADDR addr
, int len
)
4337 if (the_low_target
.insert_point
!= NULL
)
4338 return the_low_target
.insert_point (type
, addr
, len
);
4340 /* Unsupported (see target.h). */
4345 linux_remove_point (char type
, CORE_ADDR addr
, int len
)
4347 if (the_low_target
.remove_point
!= NULL
)
4348 return the_low_target
.remove_point (type
, addr
, len
);
4350 /* Unsupported (see target.h). */
4355 linux_stopped_by_watchpoint (void)
4357 struct lwp_info
*lwp
= get_thread_lwp (current_inferior
);
4359 return lwp
->stopped_by_watchpoint
;
4363 linux_stopped_data_address (void)
4365 struct lwp_info
*lwp
= get_thread_lwp (current_inferior
);
4367 return lwp
->stopped_data_address
;
4370 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4371 #if defined(__mcoldfire__)
4372 /* These should really be defined in the kernel's ptrace.h header. */
4373 #define PT_TEXT_ADDR 49*4
4374 #define PT_DATA_ADDR 50*4
4375 #define PT_TEXT_END_ADDR 51*4
4378 /* Under uClinux, programs are loaded at non-zero offsets, which we need
4379 to tell gdb about. */
4382 linux_read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
4384 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
4385 unsigned long text
, text_end
, data
;
4386 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
4390 text
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_ADDR
, 0);
4391 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_END_ADDR
, 0);
4392 data
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_DATA_ADDR
, 0);
4396 /* Both text and data offsets produced at compile-time (and so
4397 used by gdb) are relative to the beginning of the program,
4398 with the data segment immediately following the text segment.
4399 However, the actual runtime layout in memory may put the data
4400 somewhere else, so when we send gdb a data base-address, we
4401 use the real data base address and subtract the compile-time
4402 data base-address from it (which is just the length of the
4403 text segment). BSS immediately follows data in both
4406 *data_p
= data
- (text_end
- text
);
4416 compare_ints (const void *xa
, const void *xb
)
4418 int a
= *(const int *)xa
;
4419 int b
= *(const int *)xb
;
4425 unique (int *b
, int *e
)
4434 /* Given PID, iterates over all threads in that process.
4436 Information about each thread, in a format suitable for qXfer:osdata:thread
4437 is printed to BUFFER, if it's not NULL. BUFFER is assumed to be already
4438 initialized, and the caller is responsible for finishing and appending '\0'
4441 The list of cores that threads are running on is assigned to *CORES, if it
4442 is not NULL. If no cores are found, *CORES will be set to NULL. Caller
4443 should free *CORES. */
4446 list_threads (int pid
, struct buffer
*buffer
, char **cores
)
4450 int *core_numbers
= xmalloc (sizeof (int) * allocated
);
4454 struct stat statbuf
;
4456 sprintf (pathname
, "/proc/%d/task", pid
);
4457 if (stat (pathname
, &statbuf
) == 0 && S_ISDIR (statbuf
.st_mode
))
4459 dir
= opendir (pathname
);
4462 free (core_numbers
);
4466 while ((dp
= readdir (dir
)) != NULL
)
4468 unsigned long lwp
= strtoul (dp
->d_name
, NULL
, 10);
4472 unsigned core
= linux_core_of_thread (ptid_build (pid
, lwp
, 0));
4476 char s
[sizeof ("4294967295")];
4477 sprintf (s
, "%u", core
);
4479 if (count
== allocated
)
4482 core_numbers
= realloc (core_numbers
,
4483 sizeof (int) * allocated
);
4485 core_numbers
[count
++] = core
;
4487 buffer_xml_printf (buffer
,
4489 "<column name=\"pid\">%d</column>"
4490 "<column name=\"tid\">%s</column>"
4491 "<column name=\"core\">%s</column>"
4492 "</item>", pid
, dp
->d_name
, s
);
4497 buffer_xml_printf (buffer
,
4499 "<column name=\"pid\">%d</column>"
4500 "<column name=\"tid\">%s</column>"
4501 "</item>", pid
, dp
->d_name
);
4512 struct buffer buffer2
;
4515 qsort (core_numbers
, count
, sizeof (int), compare_ints
);
4517 /* Remove duplicates. */
4519 e
= unique (b
, core_numbers
+ count
);
4521 buffer_init (&buffer2
);
4523 for (b
= core_numbers
; b
!= e
; ++b
)
4525 char number
[sizeof ("4294967295")];
4526 sprintf (number
, "%u", *b
);
4527 buffer_xml_printf (&buffer2
, "%s%s",
4528 (b
== core_numbers
) ? "" : ",", number
);
4530 buffer_grow_str0 (&buffer2
, "");
4532 *cores
= buffer_finish (&buffer2
);
4535 free (core_numbers
);
4539 show_process (int pid
, const char *username
, struct buffer
*buffer
)
4543 char cmd
[MAXPATHLEN
+ 1];
4545 sprintf (pathname
, "/proc/%d/cmdline", pid
);
4547 if ((f
= fopen (pathname
, "r")) != NULL
)
4549 size_t len
= fread (cmd
, 1, sizeof (cmd
) - 1, f
);
4554 for (i
= 0; i
< len
; i
++)
4559 buffer_xml_printf (buffer
,
4561 "<column name=\"pid\">%d</column>"
4562 "<column name=\"user\">%s</column>"
4563 "<column name=\"command\">%s</column>",
4568 /* This only collects core numbers, and does not print threads. */
4569 list_threads (pid
, NULL
, &cores
);
4573 buffer_xml_printf (buffer
,
4574 "<column name=\"cores\">%s</column>", cores
);
4578 buffer_xml_printf (buffer
, "</item>");
4585 linux_qxfer_osdata (const char *annex
,
4586 unsigned char *readbuf
, unsigned const char *writebuf
,
4587 CORE_ADDR offset
, int len
)
4589 /* We make the process list snapshot when the object starts to be
4591 static const char *buf
;
4592 static long len_avail
= -1;
4593 static struct buffer buffer
;
4599 if (strcmp (annex
, "processes") == 0)
4601 else if (strcmp (annex
, "threads") == 0)
4606 if (!readbuf
|| writebuf
)
4611 if (len_avail
!= -1 && len_avail
!= 0)
4612 buffer_free (&buffer
);
4615 buffer_init (&buffer
);
4617 buffer_grow_str (&buffer
, "<osdata type=\"processes\">");
4619 buffer_grow_str (&buffer
, "<osdata type=\"threads\">");
4621 dirp
= opendir ("/proc");
4625 while ((dp
= readdir (dirp
)) != NULL
)
4627 struct stat statbuf
;
4628 char procentry
[sizeof ("/proc/4294967295")];
4630 if (!isdigit (dp
->d_name
[0])
4631 || strlen (dp
->d_name
) > sizeof ("4294967295") - 1)
4634 sprintf (procentry
, "/proc/%s", dp
->d_name
);
4635 if (stat (procentry
, &statbuf
) == 0
4636 && S_ISDIR (statbuf
.st_mode
))
4638 int pid
= (int) strtoul (dp
->d_name
, NULL
, 10);
4642 struct passwd
*entry
= getpwuid (statbuf
.st_uid
);
4643 show_process (pid
, entry
? entry
->pw_name
: "?", &buffer
);
4647 list_threads (pid
, &buffer
, NULL
);
4654 buffer_grow_str0 (&buffer
, "</osdata>\n");
4655 buf
= buffer_finish (&buffer
);
4656 len_avail
= strlen (buf
);
4659 if (offset
>= len_avail
)
4661 /* Done. Get rid of the data. */
4662 buffer_free (&buffer
);
4668 if (len
> len_avail
- offset
)
4669 len
= len_avail
- offset
;
4670 memcpy (readbuf
, buf
+ offset
, len
);
4675 /* Convert a native/host siginfo object, into/from the siginfo in the
4676 layout of the inferiors' architecture. */
4679 siginfo_fixup (struct siginfo
*siginfo
, void *inf_siginfo
, int direction
)
4683 if (the_low_target
.siginfo_fixup
!= NULL
)
4684 done
= the_low_target
.siginfo_fixup (siginfo
, inf_siginfo
, direction
);
4686 /* If there was no callback, or the callback didn't do anything,
4687 then just do a straight memcpy. */
4691 memcpy (siginfo
, inf_siginfo
, sizeof (struct siginfo
));
4693 memcpy (inf_siginfo
, siginfo
, sizeof (struct siginfo
));
4698 linux_xfer_siginfo (const char *annex
, unsigned char *readbuf
,
4699 unsigned const char *writebuf
, CORE_ADDR offset
, int len
)
4702 struct siginfo siginfo
;
4703 char inf_siginfo
[sizeof (struct siginfo
)];
4705 if (current_inferior
== NULL
)
4708 pid
= lwpid_of (get_thread_lwp (current_inferior
));
4711 fprintf (stderr
, "%s siginfo for lwp %d.\n",
4712 readbuf
!= NULL
? "Reading" : "Writing",
4715 if (offset
> sizeof (siginfo
))
4718 if (ptrace (PTRACE_GETSIGINFO
, pid
, 0, &siginfo
) != 0)
4721 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
4722 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
4723 inferior with a 64-bit GDBSERVER should look the same as debugging it
4724 with a 32-bit GDBSERVER, we need to convert it. */
4725 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
4727 if (offset
+ len
> sizeof (siginfo
))
4728 len
= sizeof (siginfo
) - offset
;
4730 if (readbuf
!= NULL
)
4731 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
4734 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
4736 /* Convert back to ptrace layout before flushing it out. */
4737 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
4739 if (ptrace (PTRACE_SETSIGINFO
, pid
, 0, &siginfo
) != 0)
4746 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4747 so we notice when children change state; as the handler for the
4748 sigsuspend in my_waitpid. */
4751 sigchld_handler (int signo
)
4753 int old_errno
= errno
;
4756 /* fprintf is not async-signal-safe, so call write directly. */
4757 write (2, "sigchld_handler\n", sizeof ("sigchld_handler\n") - 1);
4759 if (target_is_async_p ())
4760 async_file_mark (); /* trigger a linux_wait */
4766 linux_supports_non_stop (void)
4772 linux_async (int enable
)
4774 int previous
= (linux_event_pipe
[0] != -1);
4777 fprintf (stderr
, "linux_async (%d), previous=%d\n",
4780 if (previous
!= enable
)
4783 sigemptyset (&mask
);
4784 sigaddset (&mask
, SIGCHLD
);
4786 sigprocmask (SIG_BLOCK
, &mask
, NULL
);
4790 if (pipe (linux_event_pipe
) == -1)
4791 fatal ("creating event pipe failed.");
4793 fcntl (linux_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4794 fcntl (linux_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4796 /* Register the event loop handler. */
4797 add_file_handler (linux_event_pipe
[0],
4798 handle_target_event
, NULL
);
4800 /* Always trigger a linux_wait. */
4805 delete_file_handler (linux_event_pipe
[0]);
4807 close (linux_event_pipe
[0]);
4808 close (linux_event_pipe
[1]);
4809 linux_event_pipe
[0] = -1;
4810 linux_event_pipe
[1] = -1;
4813 sigprocmask (SIG_UNBLOCK
, &mask
, NULL
);
4820 linux_start_non_stop (int nonstop
)
4822 /* Register or unregister from event-loop accordingly. */
4823 linux_async (nonstop
);
4828 linux_supports_multi_process (void)
4834 /* Enumerate spufs IDs for process PID. */
4836 spu_enumerate_spu_ids (long pid
, unsigned char *buf
, CORE_ADDR offset
, int len
)
4842 struct dirent
*entry
;
4844 sprintf (path
, "/proc/%ld/fd", pid
);
4845 dir
= opendir (path
);
4850 while ((entry
= readdir (dir
)) != NULL
)
4856 fd
= atoi (entry
->d_name
);
4860 sprintf (path
, "/proc/%ld/fd/%d", pid
, fd
);
4861 if (stat (path
, &st
) != 0)
4863 if (!S_ISDIR (st
.st_mode
))
4866 if (statfs (path
, &stfs
) != 0)
4868 if (stfs
.f_type
!= SPUFS_MAGIC
)
4871 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4873 *(unsigned int *)(buf
+ pos
- offset
) = fd
;
4883 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
4884 object type, using the /proc file system. */
4886 linux_qxfer_spu (const char *annex
, unsigned char *readbuf
,
4887 unsigned const char *writebuf
,
4888 CORE_ADDR offset
, int len
)
4890 long pid
= lwpid_of (get_thread_lwp (current_inferior
));
4895 if (!writebuf
&& !readbuf
)
4903 return spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4906 sprintf (buf
, "/proc/%ld/fd/%s", pid
, annex
);
4907 fd
= open (buf
, writebuf
? O_WRONLY
: O_RDONLY
);
4912 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4919 ret
= write (fd
, writebuf
, (size_t) len
);
4921 ret
= read (fd
, readbuf
, (size_t) len
);
4928 linux_core_of_thread (ptid_t ptid
)
4930 char filename
[sizeof ("/proc//task//stat")
4931 + 2 * 20 /* decimal digits for 2 numbers, max 2^64 bit each */
4934 char *content
= NULL
;
4937 int content_read
= 0;
4941 sprintf (filename
, "/proc/%d/task/%ld/stat",
4942 ptid_get_pid (ptid
), ptid_get_lwp (ptid
));
4943 f
= fopen (filename
, "r");
4950 content
= realloc (content
, content_read
+ 1024);
4951 n
= fread (content
+ content_read
, 1, 1024, f
);
4955 content
[content_read
] = '\0';
4960 p
= strchr (content
, '(');
4964 p
= strchr (p
, ')');
4968 /* If the first field after program name has index 0, then core number is
4969 the field with index 36. There's no constant for that anywhere. */
4971 p
= strtok_r (p
, " ", &ts
);
4972 for (i
= 0; p
!= NULL
&& i
!= 36; ++i
)
4973 p
= strtok_r (NULL
, " ", &ts
);
4975 if (p
== NULL
|| sscanf (p
, "%d", &core
) == 0)
4985 linux_process_qsupported (const char *query
)
4987 if (the_low_target
.process_qsupported
!= NULL
)
4988 the_low_target
.process_qsupported (query
);
4992 linux_supports_tracepoints (void)
4994 if (*the_low_target
.supports_tracepoints
== NULL
)
4997 return (*the_low_target
.supports_tracepoints
) ();
5001 linux_read_pc (struct regcache
*regcache
)
5003 if (the_low_target
.get_pc
== NULL
)
5006 return (*the_low_target
.get_pc
) (regcache
);
5010 linux_write_pc (struct regcache
*regcache
, CORE_ADDR pc
)
5012 gdb_assert (the_low_target
.set_pc
!= NULL
);
5014 (*the_low_target
.set_pc
) (regcache
, pc
);
5018 linux_thread_stopped (struct thread_info
*thread
)
5020 return get_thread_lwp (thread
)->stopped
;
5023 /* This exposes stop-all-threads functionality to other modules. */
5026 linux_pause_all (int freeze
)
5028 stop_all_lwps (freeze
, NULL
);
5031 /* This exposes unstop-all-threads functionality to other gdbserver
5035 linux_unpause_all (int unfreeze
)
5037 unstop_all_lwps (unfreeze
, NULL
);
5041 linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint
, CORE_ADDR tpaddr
,
5042 CORE_ADDR collector
,
5045 CORE_ADDR
*jump_entry
,
5046 unsigned char *jjump_pad_insn
,
5047 ULONGEST
*jjump_pad_insn_size
,
5048 CORE_ADDR
*adjusted_insn_addr
,
5049 CORE_ADDR
*adjusted_insn_addr_end
)
5051 return (*the_low_target
.install_fast_tracepoint_jump_pad
)
5052 (tpoint
, tpaddr
, collector
, lockaddr
, orig_size
,
5053 jump_entry
, jjump_pad_insn
, jjump_pad_insn_size
,
5054 adjusted_insn_addr
, adjusted_insn_addr_end
);
5057 static struct target_ops linux_target_ops
= {
5058 linux_create_inferior
,
5067 linux_fetch_registers
,
5068 linux_store_registers
,
5071 linux_look_up_symbols
,
5072 linux_request_interrupt
,
5076 linux_stopped_by_watchpoint
,
5077 linux_stopped_data_address
,
5078 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
5083 #ifdef USE_THREAD_DB
5084 thread_db_get_tls_address
,
5089 hostio_last_error_from_errno
,
5092 linux_supports_non_stop
,
5094 linux_start_non_stop
,
5095 linux_supports_multi_process
,
5096 #ifdef USE_THREAD_DB
5097 thread_db_handle_monitor_command
,
5101 linux_core_of_thread
,
5102 linux_process_qsupported
,
5103 linux_supports_tracepoints
,
5106 linux_thread_stopped
,
5110 linux_cancel_breakpoints
,
5111 linux_stabilize_threads
,
5112 linux_install_fast_tracepoint_jump_pad
5116 linux_init_signals ()
5118 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
5119 to find what the cancel signal actually is. */
5120 #ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
5121 signal (__SIGRTMIN
+1, SIG_IGN
);
5126 initialize_low (void)
5128 struct sigaction sigchld_action
;
5129 memset (&sigchld_action
, 0, sizeof (sigchld_action
));
5130 set_target_ops (&linux_target_ops
);
5131 set_breakpoint_data (the_low_target
.breakpoint
,
5132 the_low_target
.breakpoint_len
);
5133 linux_init_signals ();
5134 linux_test_for_tracefork ();
5135 #ifdef HAVE_LINUX_REGSETS
5136 for (num_regsets
= 0; target_regsets
[num_regsets
].size
>= 0; num_regsets
++)
5138 disabled_regsets
= xmalloc (num_regsets
);
5141 sigchld_action
.sa_handler
= sigchld_handler
;
5142 sigemptyset (&sigchld_action
.sa_mask
);
5143 sigchld_action
.sa_flags
= SA_RESTART
;
5144 sigaction (SIGCHLD
, &sigchld_action
, NULL
);