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)
101 /* This is the kernel's hard limit. Not to be confused with
104 #define __SIGRTMIN 32
108 #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
113 /* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
114 representation of the thread ID.
116 ``all_lwps'' is keyed by the process ID - which on Linux is (presently)
117 the same as the LWP ID.
119 ``all_processes'' is keyed by the "overall process ID", which
120 GNU/Linux calls tgid, "thread group ID". */
122 struct inferior_list all_lwps
;
124 /* A list of all unknown processes which receive stop signals. Some other
125 process will presumably claim each of these as forked children
128 struct inferior_list stopped_pids
;
130 /* FIXME this is a bit of a hack, and could be removed. */
131 int stopping_threads
;
133 /* FIXME make into a target method? */
134 int using_threads
= 1;
136 /* True if we're presently stabilizing threads (moving them out of
138 static int stabilizing_threads
;
140 /* This flag is true iff we've just created or attached to our first
141 inferior but it has not stopped yet. As soon as it does, we need
142 to call the low target's arch_setup callback. Doing this only on
143 the first inferior avoids reinializing the architecture on every
144 inferior, and avoids messing with the register caches of the
145 already running inferiors. NOTE: this assumes all inferiors under
146 control of gdbserver have the same architecture. */
147 static int new_inferior
;
149 static void linux_resume_one_lwp (struct lwp_info
*lwp
,
150 int step
, int signal
, siginfo_t
*info
);
151 static void linux_resume (struct thread_resume
*resume_info
, size_t n
);
152 static void stop_all_lwps (int suspend
, struct lwp_info
*except
);
153 static void unstop_all_lwps (int unsuspend
, struct lwp_info
*except
);
154 static int linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
);
155 static void *add_lwp (ptid_t ptid
);
156 static int linux_stopped_by_watchpoint (void);
157 static void mark_lwp_dead (struct lwp_info
*lwp
, int wstat
);
158 static int linux_core_of_thread (ptid_t ptid
);
159 static void proceed_all_lwps (void);
160 static int finish_step_over (struct lwp_info
*lwp
);
161 static CORE_ADDR
get_stop_pc (struct lwp_info
*lwp
);
162 static int kill_lwp (unsigned long lwpid
, int signo
);
163 static void linux_enable_event_reporting (int pid
);
165 /* True if the low target can hardware single-step. Such targets
166 don't need a BREAKPOINT_REINSERT_ADDR callback. */
169 can_hardware_single_step (void)
171 return (the_low_target
.breakpoint_reinsert_addr
== NULL
);
174 /* True if the low target supports memory breakpoints. If so, we'll
175 have a GET_PC implementation. */
178 supports_breakpoints (void)
180 return (the_low_target
.get_pc
!= NULL
);
183 /* Returns true if this target can support fast tracepoints. This
184 does not mean that the in-process agent has been loaded in the
188 supports_fast_tracepoints (void)
190 return the_low_target
.install_fast_tracepoint_jump_pad
!= NULL
;
193 struct pending_signals
197 struct pending_signals
*prev
;
200 #define PTRACE_ARG3_TYPE void *
201 #define PTRACE_ARG4_TYPE void *
202 #define PTRACE_XFER_TYPE long
204 #ifdef HAVE_LINUX_REGSETS
205 static char *disabled_regsets
;
206 static int num_regsets
;
209 /* The read/write ends of the pipe registered as waitable file in the
211 static int linux_event_pipe
[2] = { -1, -1 };
213 /* True if we're currently in async mode. */
214 #define target_is_async_p() (linux_event_pipe[0] != -1)
216 static void send_sigstop (struct lwp_info
*lwp
);
217 static void wait_for_sigstop (struct inferior_list_entry
*entry
);
219 /* Accepts an integer PID; Returns a string representing a file that
220 can be opened to get info for the child process.
221 Space for the result is malloc'd, caller must free. */
224 linux_child_pid_to_exec_file (int pid
)
228 name1
= xmalloc (MAXPATHLEN
);
229 name2
= xmalloc (MAXPATHLEN
);
230 memset (name2
, 0, MAXPATHLEN
);
232 sprintf (name1
, "/proc/%d/exe", pid
);
233 if (readlink (name1
, name2
, MAXPATHLEN
) > 0)
245 /* Return non-zero if HEADER is a 64-bit ELF file. */
248 elf_64_header_p (const Elf64_Ehdr
*header
)
250 return (header
->e_ident
[EI_MAG0
] == ELFMAG0
251 && header
->e_ident
[EI_MAG1
] == ELFMAG1
252 && header
->e_ident
[EI_MAG2
] == ELFMAG2
253 && header
->e_ident
[EI_MAG3
] == ELFMAG3
254 && header
->e_ident
[EI_CLASS
] == ELFCLASS64
);
257 /* Return non-zero if FILE is a 64-bit ELF file,
258 zero if the file is not a 64-bit ELF file,
259 and -1 if the file is not accessible or doesn't exist. */
262 elf_64_file_p (const char *file
)
267 fd
= open (file
, O_RDONLY
);
271 if (read (fd
, &header
, sizeof (header
)) != sizeof (header
))
278 return elf_64_header_p (&header
);
282 delete_lwp (struct lwp_info
*lwp
)
284 remove_thread (get_lwp_thread (lwp
));
285 remove_inferior (&all_lwps
, &lwp
->head
);
286 free (lwp
->arch_private
);
290 /* Add a process to the common process list, and set its private
293 static struct process_info
*
294 linux_add_process (int pid
, int attached
)
296 struct process_info
*proc
;
298 /* Is this the first process? If so, then set the arch. */
299 if (all_processes
.head
== NULL
)
302 proc
= add_process (pid
, attached
);
303 proc
->private = xcalloc (1, sizeof (*proc
->private));
305 if (the_low_target
.new_process
!= NULL
)
306 proc
->private->arch_private
= the_low_target
.new_process ();
311 /* Wrapper function for waitpid which handles EINTR, and emulates
312 __WALL for systems where that is not available. */
315 my_waitpid (int pid
, int *status
, int flags
)
320 fprintf (stderr
, "my_waitpid (%d, 0x%x)\n", pid
, flags
);
324 sigset_t block_mask
, org_mask
, wake_mask
;
327 wnohang
= (flags
& WNOHANG
) != 0;
328 flags
&= ~(__WALL
| __WCLONE
);
331 /* Block all signals while here. This avoids knowing about
332 LinuxThread's signals. */
333 sigfillset (&block_mask
);
334 sigprocmask (SIG_BLOCK
, &block_mask
, &org_mask
);
336 /* ... except during the sigsuspend below. */
337 sigemptyset (&wake_mask
);
341 /* Since all signals are blocked, there's no need to check
343 ret
= waitpid (pid
, status
, flags
);
346 if (ret
== -1 && out_errno
!= ECHILD
)
351 if (flags
& __WCLONE
)
353 /* We've tried both flavors now. If WNOHANG is set,
354 there's nothing else to do, just bail out. */
359 fprintf (stderr
, "blocking\n");
361 /* Block waiting for signals. */
362 sigsuspend (&wake_mask
);
368 sigprocmask (SIG_SETMASK
, &org_mask
, NULL
);
373 ret
= waitpid (pid
, status
, flags
);
374 while (ret
== -1 && errno
== EINTR
);
379 fprintf (stderr
, "my_waitpid (%d, 0x%x): status(%x), %d\n",
380 pid
, flags
, status
? *status
: -1, ret
);
386 /* Handle a GNU/Linux extended wait response. If we see a clone
387 event, we need to add the new LWP to our list (and not report the
388 trap to higher layers). */
391 handle_extended_wait (struct lwp_info
*event_child
, int wstat
)
393 int event
= wstat
>> 16;
394 struct lwp_info
*new_lwp
;
396 if (event
== PTRACE_EVENT_CLONE
)
399 unsigned long new_pid
;
400 int ret
, status
= W_STOPCODE (SIGSTOP
);
402 ptrace (PTRACE_GETEVENTMSG
, lwpid_of (event_child
), 0, &new_pid
);
404 /* If we haven't already seen the new PID stop, wait for it now. */
405 if (! pull_pid_from_list (&stopped_pids
, new_pid
))
407 /* The new child has a pending SIGSTOP. We can't affect it until it
408 hits the SIGSTOP, but we're already attached. */
410 ret
= my_waitpid (new_pid
, &status
, __WALL
);
413 perror_with_name ("waiting for new child");
414 else if (ret
!= new_pid
)
415 warning ("wait returned unexpected PID %d", ret
);
416 else if (!WIFSTOPPED (status
))
417 warning ("wait returned unexpected status 0x%x", status
);
420 linux_enable_event_reporting (new_pid
);
422 ptid
= ptid_build (pid_of (event_child
), new_pid
, 0);
423 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
424 add_thread (ptid
, new_lwp
);
426 /* Either we're going to immediately resume the new thread
427 or leave it stopped. linux_resume_one_lwp is a nop if it
428 thinks the thread is currently running, so set this first
429 before calling linux_resume_one_lwp. */
430 new_lwp
->stopped
= 1;
432 /* Normally we will get the pending SIGSTOP. But in some cases
433 we might get another signal delivered to the group first.
434 If we do get another signal, be sure not to lose it. */
435 if (WSTOPSIG (status
) == SIGSTOP
)
437 if (stopping_threads
)
438 new_lwp
->stop_pc
= get_stop_pc (new_lwp
);
440 linux_resume_one_lwp (new_lwp
, 0, 0, NULL
);
444 new_lwp
->stop_expected
= 1;
446 if (stopping_threads
)
448 new_lwp
->stop_pc
= get_stop_pc (new_lwp
);
449 new_lwp
->status_pending_p
= 1;
450 new_lwp
->status_pending
= status
;
453 /* Pass the signal on. This is what GDB does - except
454 shouldn't we really report it instead? */
455 linux_resume_one_lwp (new_lwp
, 0, WSTOPSIG (status
), NULL
);
458 /* Always resume the current thread. If we are stopping
459 threads, it will have a pending SIGSTOP; we may as well
461 linux_resume_one_lwp (event_child
, event_child
->stepping
, 0, NULL
);
465 /* Return the PC as read from the regcache of LWP, without any
469 get_pc (struct lwp_info
*lwp
)
471 struct thread_info
*saved_inferior
;
472 struct regcache
*regcache
;
475 if (the_low_target
.get_pc
== NULL
)
478 saved_inferior
= current_inferior
;
479 current_inferior
= get_lwp_thread (lwp
);
481 regcache
= get_thread_regcache (current_inferior
, 1);
482 pc
= (*the_low_target
.get_pc
) (regcache
);
485 fprintf (stderr
, "pc is 0x%lx\n", (long) pc
);
487 current_inferior
= saved_inferior
;
491 /* This function should only be called if LWP got a SIGTRAP.
492 The SIGTRAP could mean several things.
494 On i386, where decr_pc_after_break is non-zero:
495 If we were single-stepping this process using PTRACE_SINGLESTEP,
496 we will get only the one SIGTRAP (even if the instruction we
497 stepped over was a breakpoint). The value of $eip will be the
499 If we continue the process using PTRACE_CONT, we will get a
500 SIGTRAP when we hit a breakpoint. The value of $eip will be
501 the instruction after the breakpoint (i.e. needs to be
502 decremented). If we report the SIGTRAP to GDB, we must also
503 report the undecremented PC. If we cancel the SIGTRAP, we
504 must resume at the decremented PC.
506 (Presumably, not yet tested) On a non-decr_pc_after_break machine
507 with hardware or kernel single-step:
508 If we single-step over a breakpoint instruction, our PC will
509 point at the following instruction. If we continue and hit a
510 breakpoint instruction, our PC will point at the breakpoint
514 get_stop_pc (struct lwp_info
*lwp
)
518 if (the_low_target
.get_pc
== NULL
)
521 stop_pc
= get_pc (lwp
);
523 if (WSTOPSIG (lwp
->last_status
) == SIGTRAP
525 && !lwp
->stopped_by_watchpoint
526 && lwp
->last_status
>> 16 == 0)
527 stop_pc
-= the_low_target
.decr_pc_after_break
;
530 fprintf (stderr
, "stop pc is 0x%lx\n", (long) stop_pc
);
536 add_lwp (ptid_t ptid
)
538 struct lwp_info
*lwp
;
540 lwp
= (struct lwp_info
*) xmalloc (sizeof (*lwp
));
541 memset (lwp
, 0, sizeof (*lwp
));
545 if (the_low_target
.new_thread
!= NULL
)
546 lwp
->arch_private
= the_low_target
.new_thread ();
548 add_inferior_to_list (&all_lwps
, &lwp
->head
);
553 /* Start an inferior process and returns its pid.
554 ALLARGS is a vector of program-name and args. */
557 linux_create_inferior (char *program
, char **allargs
)
559 struct lwp_info
*new_lwp
;
563 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
569 perror_with_name ("fork");
573 ptrace (PTRACE_TRACEME
, 0, 0, 0);
575 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
576 signal (__SIGRTMIN
+ 1, SIG_DFL
);
581 execv (program
, allargs
);
583 execvp (program
, allargs
);
585 fprintf (stderr
, "Cannot exec %s: %s.\n", program
,
591 linux_add_process (pid
, 0);
593 ptid
= ptid_build (pid
, pid
, 0);
594 new_lwp
= add_lwp (ptid
);
595 add_thread (ptid
, new_lwp
);
596 new_lwp
->must_set_ptrace_flags
= 1;
601 /* Attach to an inferior process. */
604 linux_attach_lwp_1 (unsigned long lwpid
, int initial
)
607 struct lwp_info
*new_lwp
;
609 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) != 0)
613 /* If we fail to attach to an LWP, just warn. */
614 fprintf (stderr
, "Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
615 strerror (errno
), errno
);
620 /* If we fail to attach to a process, report an error. */
621 error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
622 strerror (errno
), errno
);
626 /* NOTE/FIXME: This lwp might have not been the tgid. */
627 ptid
= ptid_build (lwpid
, lwpid
, 0);
630 /* Note that extracting the pid from the current inferior is
631 safe, since we're always called in the context of the same
632 process as this new thread. */
633 int pid
= pid_of (get_thread_lwp (current_inferior
));
634 ptid
= ptid_build (pid
, lwpid
, 0);
637 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
638 add_thread (ptid
, new_lwp
);
640 /* We need to wait for SIGSTOP before being able to make the next
641 ptrace call on this LWP. */
642 new_lwp
->must_set_ptrace_flags
= 1;
644 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
647 There are several cases to consider here:
649 1) gdbserver has already attached to the process and is being notified
650 of a new thread that is being created.
651 In this case we should ignore that SIGSTOP and resume the
652 process. This is handled below by setting stop_expected = 1,
653 and the fact that add_thread sets last_resume_kind ==
656 2) This is the first thread (the process thread), and we're attaching
657 to it via attach_inferior.
658 In this case we want the process thread to stop.
659 This is handled by having linux_attach set last_resume_kind ==
660 resume_stop after we return.
661 ??? If the process already has several threads we leave the other
664 3) GDB is connecting to gdbserver and is requesting an enumeration of all
666 In this case we want the thread to stop.
667 FIXME: This case is currently not properly handled.
668 We should wait for the SIGSTOP but don't. Things work apparently
669 because enough time passes between when we ptrace (ATTACH) and when
670 gdb makes the next ptrace call on the thread.
672 On the other hand, if we are currently trying to stop all threads, we
673 should treat the new thread as if we had sent it a SIGSTOP. This works
674 because we are guaranteed that the add_lwp call above added us to the
675 end of the list, and so the new thread has not yet reached
676 wait_for_sigstop (but will). */
677 new_lwp
->stop_expected
= 1;
681 linux_attach_lwp (unsigned long lwpid
)
683 linux_attach_lwp_1 (lwpid
, 0);
687 linux_attach (unsigned long pid
)
689 linux_attach_lwp_1 (pid
, 1);
690 linux_add_process (pid
, 1);
694 struct thread_info
*thread
;
696 /* Don't ignore the initial SIGSTOP if we just attached to this
697 process. It will be collected by wait shortly. */
698 thread
= find_thread_ptid (ptid_build (pid
, pid
, 0));
699 thread
->last_resume_kind
= resume_stop
;
712 second_thread_of_pid_p (struct inferior_list_entry
*entry
, void *args
)
714 struct counter
*counter
= args
;
716 if (ptid_get_pid (entry
->id
) == counter
->pid
)
718 if (++counter
->count
> 1)
726 last_thread_of_process_p (struct thread_info
*thread
)
728 ptid_t ptid
= ((struct inferior_list_entry
*)thread
)->id
;
729 int pid
= ptid_get_pid (ptid
);
730 struct counter counter
= { pid
, 0 };
732 return (find_inferior (&all_threads
,
733 second_thread_of_pid_p
, &counter
) == NULL
);
736 /* Kill the inferior lwp. */
739 linux_kill_one_lwp (struct inferior_list_entry
*entry
, void *args
)
741 struct thread_info
*thread
= (struct thread_info
*) entry
;
742 struct lwp_info
*lwp
= get_thread_lwp (thread
);
744 int pid
= * (int *) args
;
746 if (ptid_get_pid (entry
->id
) != pid
)
749 /* We avoid killing the first thread here, because of a Linux kernel (at
750 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
751 the children get a chance to be reaped, it will remain a zombie
754 if (lwpid_of (lwp
) == pid
)
757 fprintf (stderr
, "lkop: is last of process %s\n",
758 target_pid_to_str (entry
->id
));
764 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
766 /* Make sure it died. The loop is most likely unnecessary. */
767 pid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
768 } while (pid
> 0 && WIFSTOPPED (wstat
));
776 struct process_info
*process
;
777 struct lwp_info
*lwp
;
778 struct thread_info
*thread
;
782 process
= find_process_pid (pid
);
786 /* If we're killing a running inferior, make sure it is stopped
787 first, as PTRACE_KILL will not work otherwise. */
788 stop_all_lwps (0, NULL
);
790 find_inferior (&all_threads
, linux_kill_one_lwp
, &pid
);
792 /* See the comment in linux_kill_one_lwp. We did not kill the first
793 thread in the list, so do so now. */
794 lwp
= find_lwp_pid (pid_to_ptid (pid
));
795 thread
= get_lwp_thread (lwp
);
798 fprintf (stderr
, "lk_1: killing lwp %ld, for pid: %d\n",
799 lwpid_of (lwp
), pid
);
803 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
805 /* Make sure it died. The loop is most likely unnecessary. */
806 lwpid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
807 } while (lwpid
> 0 && WIFSTOPPED (wstat
));
809 the_target
->mourn (process
);
811 /* Since we presently can only stop all lwps of all processes, we
812 need to unstop lwps of other processes. */
813 unstop_all_lwps (0, NULL
);
818 linux_detach_one_lwp (struct inferior_list_entry
*entry
, void *args
)
820 struct thread_info
*thread
= (struct thread_info
*) entry
;
821 struct lwp_info
*lwp
= get_thread_lwp (thread
);
822 int pid
= * (int *) args
;
824 if (ptid_get_pid (entry
->id
) != pid
)
827 /* If this process is stopped but is expecting a SIGSTOP, then make
828 sure we take care of that now. This isn't absolutely guaranteed
829 to collect the SIGSTOP, but is fairly likely to. */
830 if (lwp
->stop_expected
)
833 /* Clear stop_expected, so that the SIGSTOP will be reported. */
834 lwp
->stop_expected
= 0;
835 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
836 linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
839 /* Flush any pending changes to the process's registers. */
840 regcache_invalidate_one ((struct inferior_list_entry
*)
841 get_lwp_thread (lwp
));
843 /* Finally, let it resume. */
844 ptrace (PTRACE_DETACH
, lwpid_of (lwp
), 0, 0);
851 linux_detach (int pid
)
853 struct process_info
*process
;
855 process
= find_process_pid (pid
);
859 /* Stop all threads before detaching. First, ptrace requires that
860 the thread is stopped to sucessfully detach. Second, thread_db
861 may need to uninstall thread event breakpoints from memory, which
862 only works with a stopped process anyway. */
863 stop_all_lwps (0, NULL
);
866 thread_db_detach (process
);
869 /* Stabilize threads (move out of jump pads). */
870 stabilize_threads ();
872 find_inferior (&all_threads
, linux_detach_one_lwp
, &pid
);
874 the_target
->mourn (process
);
876 /* Since we presently can only stop all lwps of all processes, we
877 need to unstop lwps of other processes. */
878 unstop_all_lwps (0, NULL
);
882 /* Remove all LWPs that belong to process PROC from the lwp list. */
885 delete_lwp_callback (struct inferior_list_entry
*entry
, void *proc
)
887 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
888 struct process_info
*process
= proc
;
890 if (pid_of (lwp
) == pid_of (process
))
897 linux_mourn (struct process_info
*process
)
899 struct process_info_private
*priv
;
902 thread_db_mourn (process
);
905 find_inferior (&all_lwps
, delete_lwp_callback
, process
);
907 /* Freeing all private data. */
908 priv
= process
->private;
909 free (priv
->arch_private
);
911 process
->private = NULL
;
913 remove_process (process
);
920 struct process_info
*process
;
922 process
= find_process_pid (pid
);
927 ret
= my_waitpid (pid
, &status
, 0);
928 if (WIFEXITED (status
) || WIFSIGNALED (status
))
930 } while (ret
!= -1 || errno
!= ECHILD
);
933 /* Return nonzero if the given thread is still alive. */
935 linux_thread_alive (ptid_t ptid
)
937 struct lwp_info
*lwp
= find_lwp_pid (ptid
);
939 /* We assume we always know if a thread exits. If a whole process
940 exited but we still haven't been able to report it to GDB, we'll
941 hold on to the last lwp of the dead process. */
948 /* Return 1 if this lwp has an interesting status pending. */
950 status_pending_p_callback (struct inferior_list_entry
*entry
, void *arg
)
952 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
953 ptid_t ptid
= * (ptid_t
*) arg
;
954 struct thread_info
*thread
;
956 /* Check if we're only interested in events from a specific process
958 if (!ptid_equal (minus_one_ptid
, ptid
)
959 && ptid_get_pid (ptid
) != ptid_get_pid (lwp
->head
.id
))
962 thread
= get_lwp_thread (lwp
);
964 /* If we got a `vCont;t', but we haven't reported a stop yet, do
965 report any status pending the LWP may have. */
966 if (thread
->last_resume_kind
== resume_stop
967 && thread
->last_status
.kind
!= TARGET_WAITKIND_IGNORE
)
970 return lwp
->status_pending_p
;
974 same_lwp (struct inferior_list_entry
*entry
, void *data
)
976 ptid_t ptid
= *(ptid_t
*) data
;
979 if (ptid_get_lwp (ptid
) != 0)
980 lwp
= ptid_get_lwp (ptid
);
982 lwp
= ptid_get_pid (ptid
);
984 if (ptid_get_lwp (entry
->id
) == lwp
)
991 find_lwp_pid (ptid_t ptid
)
993 return (struct lwp_info
*) find_inferior (&all_lwps
, same_lwp
, &ptid
);
996 static struct lwp_info
*
997 linux_wait_for_lwp (ptid_t ptid
, int *wstatp
, int options
)
1000 int to_wait_for
= -1;
1001 struct lwp_info
*child
= NULL
;
1004 fprintf (stderr
, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid
));
1006 if (ptid_equal (ptid
, minus_one_ptid
))
1007 to_wait_for
= -1; /* any child */
1009 to_wait_for
= ptid_get_lwp (ptid
); /* this lwp only */
1015 ret
= my_waitpid (to_wait_for
, wstatp
, options
);
1016 if (ret
== 0 || (ret
== -1 && errno
== ECHILD
&& (options
& WNOHANG
)))
1019 perror_with_name ("waitpid");
1022 && (!WIFSTOPPED (*wstatp
)
1023 || (WSTOPSIG (*wstatp
) != 32
1024 && WSTOPSIG (*wstatp
) != 33)))
1025 fprintf (stderr
, "Got an event from %d (%x)\n", ret
, *wstatp
);
1027 child
= find_lwp_pid (pid_to_ptid (ret
));
1029 /* If we didn't find a process, one of two things presumably happened:
1030 - A process we started and then detached from has exited. Ignore it.
1031 - A process we are controlling has forked and the new child's stop
1032 was reported to us by the kernel. Save its PID. */
1033 if (child
== NULL
&& WIFSTOPPED (*wstatp
))
1035 add_pid_to_list (&stopped_pids
, ret
);
1038 else if (child
== NULL
)
1043 child
->last_status
= *wstatp
;
1045 /* Architecture-specific setup after inferior is running.
1046 This needs to happen after we have attached to the inferior
1047 and it is stopped for the first time, but before we access
1048 any inferior registers. */
1051 the_low_target
.arch_setup ();
1052 #ifdef HAVE_LINUX_REGSETS
1053 memset (disabled_regsets
, 0, num_regsets
);
1058 /* Fetch the possibly triggered data watchpoint info and store it in
1061 On some archs, like x86, that use debug registers to set
1062 watchpoints, it's possible that the way to know which watched
1063 address trapped, is to check the register that is used to select
1064 which address to watch. Problem is, between setting the
1065 watchpoint and reading back which data address trapped, the user
1066 may change the set of watchpoints, and, as a consequence, GDB
1067 changes the debug registers in the inferior. To avoid reading
1068 back a stale stopped-data-address when that happens, we cache in
1069 LP the fact that a watchpoint trapped, and the corresponding data
1070 address, as soon as we see CHILD stop with a SIGTRAP. If GDB
1071 changes the debug registers meanwhile, we have the cached data we
1074 if (WIFSTOPPED (*wstatp
) && WSTOPSIG (*wstatp
) == SIGTRAP
)
1076 if (the_low_target
.stopped_by_watchpoint
== NULL
)
1078 child
->stopped_by_watchpoint
= 0;
1082 struct thread_info
*saved_inferior
;
1084 saved_inferior
= current_inferior
;
1085 current_inferior
= get_lwp_thread (child
);
1087 child
->stopped_by_watchpoint
1088 = the_low_target
.stopped_by_watchpoint ();
1090 if (child
->stopped_by_watchpoint
)
1092 if (the_low_target
.stopped_data_address
!= NULL
)
1093 child
->stopped_data_address
1094 = the_low_target
.stopped_data_address ();
1096 child
->stopped_data_address
= 0;
1099 current_inferior
= saved_inferior
;
1103 /* Store the STOP_PC, with adjustment applied. This depends on the
1104 architecture being defined already (so that CHILD has a valid
1105 regcache), and on LAST_STATUS being set (to check for SIGTRAP or
1107 if (WIFSTOPPED (*wstatp
))
1108 child
->stop_pc
= get_stop_pc (child
);
1111 && WIFSTOPPED (*wstatp
)
1112 && the_low_target
.get_pc
!= NULL
)
1114 struct thread_info
*saved_inferior
= current_inferior
;
1115 struct regcache
*regcache
;
1118 current_inferior
= get_lwp_thread (child
);
1119 regcache
= get_thread_regcache (current_inferior
, 1);
1120 pc
= (*the_low_target
.get_pc
) (regcache
);
1121 fprintf (stderr
, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc
);
1122 current_inferior
= saved_inferior
;
1128 /* This function should only be called if the LWP got a SIGTRAP.
1130 Handle any tracepoint steps or hits. Return true if a tracepoint
1131 event was handled, 0 otherwise. */
1134 handle_tracepoints (struct lwp_info
*lwp
)
1136 struct thread_info
*tinfo
= get_lwp_thread (lwp
);
1137 int tpoint_related_event
= 0;
1139 /* If this tracepoint hit causes a tracing stop, we'll immediately
1140 uninsert tracepoints. To do this, we temporarily pause all
1141 threads, unpatch away, and then unpause threads. We need to make
1142 sure the unpausing doesn't resume LWP too. */
1145 /* And we need to be sure that any all-threads-stopping doesn't try
1146 to move threads out of the jump pads, as it could deadlock the
1147 inferior (LWP could be in the jump pad, maybe even holding the
1150 /* Do any necessary step collect actions. */
1151 tpoint_related_event
|= tracepoint_finished_step (tinfo
, lwp
->stop_pc
);
1153 tpoint_related_event
|= handle_tracepoint_bkpts (tinfo
, lwp
->stop_pc
);
1155 /* See if we just hit a tracepoint and do its main collect
1157 tpoint_related_event
|= tracepoint_was_hit (tinfo
, lwp
->stop_pc
);
1161 gdb_assert (lwp
->suspended
== 0);
1162 gdb_assert (!stabilizing_threads
|| lwp
->collecting_fast_tracepoint
);
1164 if (tpoint_related_event
)
1167 fprintf (stderr
, "got a tracepoint event\n");
1174 /* Convenience wrapper. Returns true if LWP is presently collecting a
1178 linux_fast_tracepoint_collecting (struct lwp_info
*lwp
,
1179 struct fast_tpoint_collect_status
*status
)
1181 CORE_ADDR thread_area
;
1183 if (the_low_target
.get_thread_area
== NULL
)
1186 /* Get the thread area address. This is used to recognize which
1187 thread is which when tracing with the in-process agent library.
1188 We don't read anything from the address, and treat it as opaque;
1189 it's the address itself that we assume is unique per-thread. */
1190 if ((*the_low_target
.get_thread_area
) (lwpid_of (lwp
), &thread_area
) == -1)
1193 return fast_tracepoint_collecting (thread_area
, lwp
->stop_pc
, status
);
1196 /* The reason we resume in the caller, is because we want to be able
1197 to pass lwp->status_pending as WSTAT, and we need to clear
1198 status_pending_p before resuming, otherwise, linux_resume_one_lwp
1199 refuses to resume. */
1202 maybe_move_out_of_jump_pad (struct lwp_info
*lwp
, int *wstat
)
1204 struct thread_info
*saved_inferior
;
1206 saved_inferior
= current_inferior
;
1207 current_inferior
= get_lwp_thread (lwp
);
1210 || (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) != SIGTRAP
))
1211 && supports_fast_tracepoints ()
1212 && in_process_agent_loaded ())
1214 struct fast_tpoint_collect_status status
;
1219 Checking whether LWP %ld needs to move out of the jump pad.\n",
1222 r
= linux_fast_tracepoint_collecting (lwp
, &status
);
1225 || (WSTOPSIG (*wstat
) != SIGILL
1226 && WSTOPSIG (*wstat
) != SIGFPE
1227 && WSTOPSIG (*wstat
) != SIGSEGV
1228 && WSTOPSIG (*wstat
) != SIGBUS
))
1230 lwp
->collecting_fast_tracepoint
= r
;
1234 if (r
== 1 && lwp
->exit_jump_pad_bkpt
== NULL
)
1236 /* Haven't executed the original instruction yet.
1237 Set breakpoint there, and wait till it's hit,
1238 then single-step until exiting the jump pad. */
1239 lwp
->exit_jump_pad_bkpt
1240 = set_breakpoint_at (status
.adjusted_insn_addr
, NULL
);
1245 Checking whether LWP %ld needs to move out of the jump pad...it does\n",
1247 current_inferior
= saved_inferior
;
1254 /* If we get a synchronous signal while collecting, *and*
1255 while executing the (relocated) original instruction,
1256 reset the PC to point at the tpoint address, before
1257 reporting to GDB. Otherwise, it's an IPA lib bug: just
1258 report the signal to GDB, and pray for the best. */
1260 lwp
->collecting_fast_tracepoint
= 0;
1263 && (status
.adjusted_insn_addr
<= lwp
->stop_pc
1264 && lwp
->stop_pc
< status
.adjusted_insn_addr_end
))
1267 struct regcache
*regcache
;
1269 /* The si_addr on a few signals references the address
1270 of the faulting instruction. Adjust that as
1272 if ((WSTOPSIG (*wstat
) == SIGILL
1273 || WSTOPSIG (*wstat
) == SIGFPE
1274 || WSTOPSIG (*wstat
) == SIGBUS
1275 || WSTOPSIG (*wstat
) == SIGSEGV
)
1276 && ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &info
) == 0
1277 /* Final check just to make sure we don't clobber
1278 the siginfo of non-kernel-sent signals. */
1279 && (uintptr_t) info
.si_addr
== lwp
->stop_pc
)
1281 info
.si_addr
= (void *) (uintptr_t) status
.tpoint_addr
;
1282 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &info
);
1285 regcache
= get_thread_regcache (get_lwp_thread (lwp
), 1);
1286 (*the_low_target
.set_pc
) (regcache
, status
.tpoint_addr
);
1287 lwp
->stop_pc
= status
.tpoint_addr
;
1289 /* Cancel any fast tracepoint lock this thread was
1291 force_unlock_trace_buffer ();
1294 if (lwp
->exit_jump_pad_bkpt
!= NULL
)
1298 "Cancelling fast exit-jump-pad: removing bkpt. "
1299 "stopping all threads momentarily.\n");
1301 stop_all_lwps (1, lwp
);
1302 cancel_breakpoints ();
1304 delete_breakpoint (lwp
->exit_jump_pad_bkpt
);
1305 lwp
->exit_jump_pad_bkpt
= NULL
;
1307 unstop_all_lwps (1, lwp
);
1309 gdb_assert (lwp
->suspended
>= 0);
1316 Checking whether LWP %ld needs to move out of the jump pad...no\n",
1319 current_inferior
= saved_inferior
;
1323 /* Enqueue one signal in the "signals to report later when out of the
1327 enqueue_one_deferred_signal (struct lwp_info
*lwp
, int *wstat
)
1329 struct pending_signals
*p_sig
;
1333 Deferring signal %d for LWP %ld.\n", WSTOPSIG (*wstat
), lwpid_of (lwp
));
1337 struct pending_signals
*sig
;
1339 for (sig
= lwp
->pending_signals_to_report
;
1343 " Already queued %d\n",
1346 fprintf (stderr
, " (no more currently queued signals)\n");
1349 /* Don't enqueue non-RT signals if they are already in the deferred
1350 queue. (SIGSTOP being the easiest signal to see ending up here
1352 if (WSTOPSIG (*wstat
) < __SIGRTMIN
)
1354 struct pending_signals
*sig
;
1356 for (sig
= lwp
->pending_signals_to_report
;
1360 if (sig
->signal
== WSTOPSIG (*wstat
))
1364 "Not requeuing already queued non-RT signal %d"
1373 p_sig
= xmalloc (sizeof (*p_sig
));
1374 p_sig
->prev
= lwp
->pending_signals_to_report
;
1375 p_sig
->signal
= WSTOPSIG (*wstat
);
1376 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
1377 ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &p_sig
->info
);
1379 lwp
->pending_signals_to_report
= p_sig
;
1382 /* Dequeue one signal from the "signals to report later when out of
1383 the jump pad" list. */
1386 dequeue_one_deferred_signal (struct lwp_info
*lwp
, int *wstat
)
1388 if (lwp
->pending_signals_to_report
!= NULL
)
1390 struct pending_signals
**p_sig
;
1392 p_sig
= &lwp
->pending_signals_to_report
;
1393 while ((*p_sig
)->prev
!= NULL
)
1394 p_sig
= &(*p_sig
)->prev
;
1396 *wstat
= W_STOPCODE ((*p_sig
)->signal
);
1397 if ((*p_sig
)->info
.si_signo
!= 0)
1398 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &(*p_sig
)->info
);
1403 fprintf (stderr
, "Reporting deferred signal %d for LWP %ld.\n",
1404 WSTOPSIG (*wstat
), lwpid_of (lwp
));
1408 struct pending_signals
*sig
;
1410 for (sig
= lwp
->pending_signals_to_report
;
1414 " Still queued %d\n",
1417 fprintf (stderr
, " (no more queued signals)\n");
1426 /* Arrange for a breakpoint to be hit again later. We don't keep the
1427 SIGTRAP status and don't forward the SIGTRAP signal to the LWP. We
1428 will handle the current event, eventually we will resume this LWP,
1429 and this breakpoint will trap again. */
1432 cancel_breakpoint (struct lwp_info
*lwp
)
1434 struct thread_info
*saved_inferior
;
1436 /* There's nothing to do if we don't support breakpoints. */
1437 if (!supports_breakpoints ())
1440 /* breakpoint_at reads from current inferior. */
1441 saved_inferior
= current_inferior
;
1442 current_inferior
= get_lwp_thread (lwp
);
1444 if ((*the_low_target
.breakpoint_at
) (lwp
->stop_pc
))
1448 "CB: Push back breakpoint for %s\n",
1449 target_pid_to_str (ptid_of (lwp
)));
1451 /* Back up the PC if necessary. */
1452 if (the_low_target
.decr_pc_after_break
)
1454 struct regcache
*regcache
1455 = get_thread_regcache (current_inferior
, 1);
1456 (*the_low_target
.set_pc
) (regcache
, lwp
->stop_pc
);
1459 current_inferior
= saved_inferior
;
1466 "CB: No breakpoint found at %s for [%s]\n",
1467 paddress (lwp
->stop_pc
),
1468 target_pid_to_str (ptid_of (lwp
)));
1471 current_inferior
= saved_inferior
;
1475 /* When the event-loop is doing a step-over, this points at the thread
1477 ptid_t step_over_bkpt
;
1479 /* Wait for an event from child PID. If PID is -1, wait for any
1480 child. Store the stop status through the status pointer WSTAT.
1481 OPTIONS is passed to the waitpid call. Return 0 if no child stop
1482 event was found and OPTIONS contains WNOHANG. Return the PID of
1483 the stopped child otherwise. */
1486 linux_wait_for_event_1 (ptid_t ptid
, int *wstat
, int options
)
1488 struct lwp_info
*event_child
, *requested_child
;
1491 requested_child
= NULL
;
1493 /* Check for a lwp with a pending status. */
1495 if (ptid_equal (ptid
, minus_one_ptid
)
1496 || ptid_equal (pid_to_ptid (ptid_get_pid (ptid
)), ptid
))
1498 event_child
= (struct lwp_info
*)
1499 find_inferior (&all_lwps
, status_pending_p_callback
, &ptid
);
1500 if (debug_threads
&& event_child
)
1501 fprintf (stderr
, "Got a pending child %ld\n", lwpid_of (event_child
));
1505 requested_child
= find_lwp_pid (ptid
);
1507 if (!stopping_threads
1508 && requested_child
->status_pending_p
1509 && requested_child
->collecting_fast_tracepoint
)
1511 enqueue_one_deferred_signal (requested_child
,
1512 &requested_child
->status_pending
);
1513 requested_child
->status_pending_p
= 0;
1514 requested_child
->status_pending
= 0;
1515 linux_resume_one_lwp (requested_child
, 0, 0, NULL
);
1518 if (requested_child
->suspended
1519 && requested_child
->status_pending_p
)
1520 fatal ("requesting an event out of a suspended child?");
1522 if (requested_child
->status_pending_p
)
1523 event_child
= requested_child
;
1526 if (event_child
!= NULL
)
1529 fprintf (stderr
, "Got an event from pending child %ld (%04x)\n",
1530 lwpid_of (event_child
), event_child
->status_pending
);
1531 *wstat
= event_child
->status_pending
;
1532 event_child
->status_pending_p
= 0;
1533 event_child
->status_pending
= 0;
1534 current_inferior
= get_lwp_thread (event_child
);
1535 return lwpid_of (event_child
);
1538 /* We only enter this loop if no process has a pending wait status. Thus
1539 any action taken in response to a wait status inside this loop is
1540 responding as soon as we detect the status, not after any pending
1544 event_child
= linux_wait_for_lwp (ptid
, wstat
, options
);
1546 if ((options
& WNOHANG
) && event_child
== NULL
)
1549 fprintf (stderr
, "WNOHANG set, no event found\n");
1553 if (event_child
== NULL
)
1554 error ("event from unknown child");
1556 current_inferior
= get_lwp_thread (event_child
);
1558 /* Check for thread exit. */
1559 if (! WIFSTOPPED (*wstat
))
1562 fprintf (stderr
, "LWP %ld exiting\n", lwpid_of (event_child
));
1564 /* If the last thread is exiting, just return. */
1565 if (last_thread_of_process_p (current_inferior
))
1568 fprintf (stderr
, "LWP %ld is last lwp of process\n",
1569 lwpid_of (event_child
));
1570 return lwpid_of (event_child
);
1575 current_inferior
= (struct thread_info
*) all_threads
.head
;
1577 fprintf (stderr
, "Current inferior is now %ld\n",
1578 lwpid_of (get_thread_lwp (current_inferior
)));
1582 current_inferior
= NULL
;
1584 fprintf (stderr
, "Current inferior is now <NULL>\n");
1587 /* If we were waiting for this particular child to do something...
1588 well, it did something. */
1589 if (requested_child
!= NULL
)
1591 int lwpid
= lwpid_of (event_child
);
1593 /* Cancel the step-over operation --- the thread that
1594 started it is gone. */
1595 if (finish_step_over (event_child
))
1596 unstop_all_lwps (1, event_child
);
1597 delete_lwp (event_child
);
1601 delete_lwp (event_child
);
1603 /* Wait for a more interesting event. */
1607 if (event_child
->must_set_ptrace_flags
)
1609 linux_enable_event_reporting (lwpid_of (event_child
));
1610 event_child
->must_set_ptrace_flags
= 0;
1613 if (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) == SIGTRAP
1614 && *wstat
>> 16 != 0)
1616 handle_extended_wait (event_child
, *wstat
);
1620 if (WIFSTOPPED (*wstat
)
1621 && WSTOPSIG (*wstat
) == SIGSTOP
1622 && event_child
->stop_expected
)
1627 fprintf (stderr
, "Expected stop.\n");
1628 event_child
->stop_expected
= 0;
1630 should_stop
= (current_inferior
->last_resume_kind
== resume_stop
1631 || stopping_threads
);
1635 linux_resume_one_lwp (event_child
,
1636 event_child
->stepping
, 0, NULL
);
1641 return lwpid_of (event_child
);
1649 linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
)
1653 if (ptid_is_pid (ptid
))
1655 /* A request to wait for a specific tgid. This is not possible
1656 with waitpid, so instead, we wait for any child, and leave
1657 children we're not interested in right now with a pending
1658 status to report later. */
1659 wait_ptid
= minus_one_ptid
;
1668 event_pid
= linux_wait_for_event_1 (wait_ptid
, wstat
, options
);
1671 && ptid_is_pid (ptid
) && ptid_get_pid (ptid
) != event_pid
)
1673 struct lwp_info
*event_child
= find_lwp_pid (pid_to_ptid (event_pid
));
1675 if (! WIFSTOPPED (*wstat
))
1676 mark_lwp_dead (event_child
, *wstat
);
1679 event_child
->status_pending_p
= 1;
1680 event_child
->status_pending
= *wstat
;
1689 /* Count the LWP's that have had events. */
1692 count_events_callback (struct inferior_list_entry
*entry
, void *data
)
1694 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1695 struct thread_info
*thread
= get_lwp_thread (lp
);
1698 gdb_assert (count
!= NULL
);
1700 /* Count only resumed LWPs that have a SIGTRAP event pending that
1701 should be reported to GDB. */
1702 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1703 && thread
->last_resume_kind
!= resume_stop
1704 && lp
->status_pending_p
1705 && WIFSTOPPED (lp
->status_pending
)
1706 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1707 && !breakpoint_inserted_here (lp
->stop_pc
))
1713 /* Select the LWP (if any) that is currently being single-stepped. */
1716 select_singlestep_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
1718 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1719 struct thread_info
*thread
= get_lwp_thread (lp
);
1721 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1722 && thread
->last_resume_kind
== resume_step
1723 && lp
->status_pending_p
)
1729 /* Select the Nth LWP that has had a SIGTRAP event that should be
1733 select_event_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
1735 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1736 struct thread_info
*thread
= get_lwp_thread (lp
);
1737 int *selector
= data
;
1739 gdb_assert (selector
!= NULL
);
1741 /* Select only resumed LWPs that have a SIGTRAP event pending. */
1742 if (thread
->last_resume_kind
!= resume_stop
1743 && thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1744 && lp
->status_pending_p
1745 && WIFSTOPPED (lp
->status_pending
)
1746 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1747 && !breakpoint_inserted_here (lp
->stop_pc
))
1748 if ((*selector
)-- == 0)
1755 cancel_breakpoints_callback (struct inferior_list_entry
*entry
, void *data
)
1757 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1758 struct thread_info
*thread
= get_lwp_thread (lp
);
1759 struct lwp_info
*event_lp
= data
;
1761 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
1765 /* If a LWP other than the LWP that we're reporting an event for has
1766 hit a GDB breakpoint (as opposed to some random trap signal),
1767 then just arrange for it to hit it again later. We don't keep
1768 the SIGTRAP status and don't forward the SIGTRAP signal to the
1769 LWP. We will handle the current event, eventually we will resume
1770 all LWPs, and this one will get its breakpoint trap again.
1772 If we do not do this, then we run the risk that the user will
1773 delete or disable the breakpoint, but the LWP will have already
1776 if (thread
->last_resume_kind
!= resume_stop
1777 && thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1778 && lp
->status_pending_p
1779 && WIFSTOPPED (lp
->status_pending
)
1780 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1782 && !lp
->stopped_by_watchpoint
1783 && cancel_breakpoint (lp
))
1784 /* Throw away the SIGTRAP. */
1785 lp
->status_pending_p
= 0;
1791 linux_cancel_breakpoints (void)
1793 find_inferior (&all_lwps
, cancel_breakpoints_callback
, NULL
);
1796 /* Select one LWP out of those that have events pending. */
1799 select_event_lwp (struct lwp_info
**orig_lp
)
1802 int random_selector
;
1803 struct lwp_info
*event_lp
;
1805 /* Give preference to any LWP that is being single-stepped. */
1807 = (struct lwp_info
*) find_inferior (&all_lwps
,
1808 select_singlestep_lwp_callback
, NULL
);
1809 if (event_lp
!= NULL
)
1813 "SEL: Select single-step %s\n",
1814 target_pid_to_str (ptid_of (event_lp
)));
1818 /* No single-stepping LWP. Select one at random, out of those
1819 which have had SIGTRAP events. */
1821 /* First see how many SIGTRAP events we have. */
1822 find_inferior (&all_lwps
, count_events_callback
, &num_events
);
1824 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
1825 random_selector
= (int)
1826 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
1828 if (debug_threads
&& num_events
> 1)
1830 "SEL: Found %d SIGTRAP events, selecting #%d\n",
1831 num_events
, random_selector
);
1833 event_lp
= (struct lwp_info
*) find_inferior (&all_lwps
,
1834 select_event_lwp_callback
,
1838 if (event_lp
!= NULL
)
1840 /* Switch the event LWP. */
1841 *orig_lp
= event_lp
;
1845 /* Decrement the suspend count of an LWP. */
1848 unsuspend_one_lwp (struct inferior_list_entry
*entry
, void *except
)
1850 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1852 /* Ignore EXCEPT. */
1858 gdb_assert (lwp
->suspended
>= 0);
1862 /* Decrement the suspend count of all LWPs, except EXCEPT, if non
1866 unsuspend_all_lwps (struct lwp_info
*except
)
1868 find_inferior (&all_lwps
, unsuspend_one_lwp
, except
);
1871 static void move_out_of_jump_pad_callback (struct inferior_list_entry
*entry
);
1872 static int stuck_in_jump_pad_callback (struct inferior_list_entry
*entry
,
1874 static int lwp_running (struct inferior_list_entry
*entry
, void *data
);
1875 static ptid_t
linux_wait_1 (ptid_t ptid
,
1876 struct target_waitstatus
*ourstatus
,
1877 int target_options
);
1879 /* Stabilize threads (move out of jump pads).
1881 If a thread is midway collecting a fast tracepoint, we need to
1882 finish the collection and move it out of the jump pad before
1883 reporting the signal.
1885 This avoids recursion while collecting (when a signal arrives
1886 midway, and the signal handler itself collects), which would trash
1887 the trace buffer. In case the user set a breakpoint in a signal
1888 handler, this avoids the backtrace showing the jump pad, etc..
1889 Most importantly, there are certain things we can't do safely if
1890 threads are stopped in a jump pad (or in its callee's). For
1893 - starting a new trace run. A thread still collecting the
1894 previous run, could trash the trace buffer when resumed. The trace
1895 buffer control structures would have been reset but the thread had
1896 no way to tell. The thread could even midway memcpy'ing to the
1897 buffer, which would mean that when resumed, it would clobber the
1898 trace buffer that had been set for a new run.
1900 - we can't rewrite/reuse the jump pads for new tracepoints
1901 safely. Say you do tstart while a thread is stopped midway while
1902 collecting. When the thread is later resumed, it finishes the
1903 collection, and returns to the jump pad, to execute the original
1904 instruction that was under the tracepoint jump at the time the
1905 older run had been started. If the jump pad had been rewritten
1906 since for something else in the new run, the thread would now
1907 execute the wrong / random instructions. */
1910 linux_stabilize_threads (void)
1912 struct thread_info
*save_inferior
;
1913 struct lwp_info
*lwp_stuck
;
1916 = (struct lwp_info
*) find_inferior (&all_lwps
,
1917 stuck_in_jump_pad_callback
, NULL
);
1918 if (lwp_stuck
!= NULL
)
1921 fprintf (stderr
, "can't stabilize, LWP %ld is stuck in jump pad\n",
1922 lwpid_of (lwp_stuck
));
1926 save_inferior
= current_inferior
;
1928 stabilizing_threads
= 1;
1931 for_each_inferior (&all_lwps
, move_out_of_jump_pad_callback
);
1933 /* Loop until all are stopped out of the jump pads. */
1934 while (find_inferior (&all_lwps
, lwp_running
, NULL
) != NULL
)
1936 struct target_waitstatus ourstatus
;
1937 struct lwp_info
*lwp
;
1941 /* Note that we go through the full wait even loop. While
1942 moving threads out of jump pad, we need to be able to step
1943 over internal breakpoints and such. */
1944 ptid
= linux_wait_1 (minus_one_ptid
, &ourstatus
, 0);
1946 if (ourstatus
.kind
== TARGET_WAITKIND_STOPPED
)
1948 lwp
= get_thread_lwp (current_inferior
);
1953 if (ourstatus
.value
.sig
!= TARGET_SIGNAL_0
1954 || current_inferior
->last_resume_kind
== resume_stop
)
1956 wstat
= W_STOPCODE (target_signal_to_host (ourstatus
.value
.sig
));
1957 enqueue_one_deferred_signal (lwp
, &wstat
);
1962 find_inferior (&all_lwps
, unsuspend_one_lwp
, NULL
);
1964 stabilizing_threads
= 0;
1966 current_inferior
= save_inferior
;
1971 = (struct lwp_info
*) find_inferior (&all_lwps
,
1972 stuck_in_jump_pad_callback
, NULL
);
1973 if (lwp_stuck
!= NULL
)
1974 fprintf (stderr
, "couldn't stabilize, LWP %ld got stuck in jump pad\n",
1975 lwpid_of (lwp_stuck
));
1979 /* Wait for process, returns status. */
1982 linux_wait_1 (ptid_t ptid
,
1983 struct target_waitstatus
*ourstatus
, int target_options
)
1986 struct lwp_info
*event_child
;
1989 int step_over_finished
;
1990 int bp_explains_trap
;
1991 int maybe_internal_trap
;
1995 /* Translate generic target options into linux options. */
1997 if (target_options
& TARGET_WNOHANG
)
2001 bp_explains_trap
= 0;
2003 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2005 /* If we were only supposed to resume one thread, only wait for
2006 that thread - if it's still alive. If it died, however - which
2007 can happen if we're coming from the thread death case below -
2008 then we need to make sure we restart the other threads. We could
2009 pick a thread at random or restart all; restarting all is less
2012 && !ptid_equal (cont_thread
, null_ptid
)
2013 && !ptid_equal (cont_thread
, minus_one_ptid
))
2015 struct thread_info
*thread
;
2017 thread
= (struct thread_info
*) find_inferior_id (&all_threads
,
2020 /* No stepping, no signal - unless one is pending already, of course. */
2023 struct thread_resume resume_info
;
2024 resume_info
.thread
= minus_one_ptid
;
2025 resume_info
.kind
= resume_continue
;
2026 resume_info
.sig
= 0;
2027 linux_resume (&resume_info
, 1);
2033 if (ptid_equal (step_over_bkpt
, null_ptid
))
2034 pid
= linux_wait_for_event (ptid
, &w
, options
);
2038 fprintf (stderr
, "step_over_bkpt set [%s], doing a blocking wait\n",
2039 target_pid_to_str (step_over_bkpt
));
2040 pid
= linux_wait_for_event (step_over_bkpt
, &w
, options
& ~WNOHANG
);
2043 if (pid
== 0) /* only if TARGET_WNOHANG */
2046 event_child
= get_thread_lwp (current_inferior
);
2048 /* If we are waiting for a particular child, and it exited,
2049 linux_wait_for_event will return its exit status. Similarly if
2050 the last child exited. If this is not the last child, however,
2051 do not report it as exited until there is a 'thread exited' response
2052 available in the remote protocol. Instead, just wait for another event.
2053 This should be safe, because if the thread crashed we will already
2054 have reported the termination signal to GDB; that should stop any
2055 in-progress stepping operations, etc.
2057 Report the exit status of the last thread to exit. This matches
2058 LinuxThreads' behavior. */
2060 if (last_thread_of_process_p (current_inferior
))
2062 if (WIFEXITED (w
) || WIFSIGNALED (w
))
2066 ourstatus
->kind
= TARGET_WAITKIND_EXITED
;
2067 ourstatus
->value
.integer
= WEXITSTATUS (w
);
2070 fprintf (stderr
, "\nChild exited with retcode = %x \n", WEXITSTATUS (w
));
2074 ourstatus
->kind
= TARGET_WAITKIND_SIGNALLED
;
2075 ourstatus
->value
.sig
= target_signal_from_host (WTERMSIG (w
));
2078 fprintf (stderr
, "\nChild terminated with signal = %x \n", WTERMSIG (w
));
2082 return ptid_of (event_child
);
2087 if (!WIFSTOPPED (w
))
2091 /* If this event was not handled before, and is not a SIGTRAP, we
2092 report it. SIGILL and SIGSEGV are also treated as traps in case
2093 a breakpoint is inserted at the current PC. If this target does
2094 not support internal breakpoints at all, we also report the
2095 SIGTRAP without further processing; it's of no concern to us. */
2097 = (supports_breakpoints ()
2098 && (WSTOPSIG (w
) == SIGTRAP
2099 || ((WSTOPSIG (w
) == SIGILL
2100 || WSTOPSIG (w
) == SIGSEGV
)
2101 && (*the_low_target
.breakpoint_at
) (event_child
->stop_pc
))));
2103 if (maybe_internal_trap
)
2105 /* Handle anything that requires bookkeeping before deciding to
2106 report the event or continue waiting. */
2108 /* First check if we can explain the SIGTRAP with an internal
2109 breakpoint, or if we should possibly report the event to GDB.
2110 Do this before anything that may remove or insert a
2112 bp_explains_trap
= breakpoint_inserted_here (event_child
->stop_pc
);
2114 /* We have a SIGTRAP, possibly a step-over dance has just
2115 finished. If so, tweak the state machine accordingly,
2116 reinsert breakpoints and delete any reinsert (software
2117 single-step) breakpoints. */
2118 step_over_finished
= finish_step_over (event_child
);
2120 /* Now invoke the callbacks of any internal breakpoints there. */
2121 check_breakpoints (event_child
->stop_pc
);
2123 /* Handle tracepoint data collecting. This may overflow the
2124 trace buffer, and cause a tracing stop, removing
2126 trace_event
= handle_tracepoints (event_child
);
2128 if (bp_explains_trap
)
2130 /* If we stepped or ran into an internal breakpoint, we've
2131 already handled it. So next time we resume (from this
2132 PC), we should step over it. */
2134 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
2136 if (breakpoint_here (event_child
->stop_pc
))
2137 event_child
->need_step_over
= 1;
2142 /* We have some other signal, possibly a step-over dance was in
2143 progress, and it should be cancelled too. */
2144 step_over_finished
= finish_step_over (event_child
);
2147 /* We have all the data we need. Either report the event to GDB, or
2148 resume threads and keep waiting for more. */
2150 /* If we're collecting a fast tracepoint, finish the collection and
2151 move out of the jump pad before delivering a signal. See
2152 linux_stabilize_threads. */
2155 && WSTOPSIG (w
) != SIGTRAP
2156 && supports_fast_tracepoints ()
2157 && in_process_agent_loaded ())
2161 "Got signal %d for LWP %ld. Check if we need "
2162 "to defer or adjust it.\n",
2163 WSTOPSIG (w
), lwpid_of (event_child
));
2165 /* Allow debugging the jump pad itself. */
2166 if (current_inferior
->last_resume_kind
!= resume_step
2167 && maybe_move_out_of_jump_pad (event_child
, &w
))
2169 enqueue_one_deferred_signal (event_child
, &w
);
2173 "Signal %d for LWP %ld deferred (in jump pad)\n",
2174 WSTOPSIG (w
), lwpid_of (event_child
));
2176 linux_resume_one_lwp (event_child
, 0, 0, NULL
);
2181 if (event_child
->collecting_fast_tracepoint
)
2185 LWP %ld was trying to move out of the jump pad (%d). \
2186 Check if we're already there.\n",
2187 lwpid_of (event_child
),
2188 event_child
->collecting_fast_tracepoint
);
2192 event_child
->collecting_fast_tracepoint
2193 = linux_fast_tracepoint_collecting (event_child
, NULL
);
2195 if (event_child
->collecting_fast_tracepoint
!= 1)
2197 /* No longer need this breakpoint. */
2198 if (event_child
->exit_jump_pad_bkpt
!= NULL
)
2202 "No longer need exit-jump-pad bkpt; removing it."
2203 "stopping all threads momentarily.\n");
2205 /* Other running threads could hit this breakpoint.
2206 We don't handle moribund locations like GDB does,
2207 instead we always pause all threads when removing
2208 breakpoints, so that any step-over or
2209 decr_pc_after_break adjustment is always taken
2210 care of while the breakpoint is still
2212 stop_all_lwps (1, event_child
);
2213 cancel_breakpoints ();
2215 delete_breakpoint (event_child
->exit_jump_pad_bkpt
);
2216 event_child
->exit_jump_pad_bkpt
= NULL
;
2218 unstop_all_lwps (1, event_child
);
2220 gdb_assert (event_child
->suspended
>= 0);
2224 if (event_child
->collecting_fast_tracepoint
== 0)
2228 "fast tracepoint finished "
2229 "collecting successfully.\n");
2231 /* We may have a deferred signal to report. */
2232 if (dequeue_one_deferred_signal (event_child
, &w
))
2235 fprintf (stderr
, "dequeued one signal.\n");
2240 fprintf (stderr
, "no deferred signals.\n");
2242 if (stabilizing_threads
)
2244 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
2245 ourstatus
->value
.sig
= TARGET_SIGNAL_0
;
2246 return ptid_of (event_child
);
2252 /* Check whether GDB would be interested in this event. */
2254 /* If GDB is not interested in this signal, don't stop other
2255 threads, and don't report it to GDB. Just resume the inferior
2256 right away. We do this for threading-related signals as well as
2257 any that GDB specifically requested we ignore. But never ignore
2258 SIGSTOP if we sent it ourselves, and do not ignore signals when
2259 stepping - they may require special handling to skip the signal
2261 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
2264 && current_inferior
->last_resume_kind
!= resume_step
2266 #if defined (USE_THREAD_DB) && !defined (__ANDROID__)
2267 (current_process ()->private->thread_db
!= NULL
2268 && (WSTOPSIG (w
) == __SIGRTMIN
2269 || WSTOPSIG (w
) == __SIGRTMIN
+ 1))
2272 (pass_signals
[target_signal_from_host (WSTOPSIG (w
))]
2273 && !(WSTOPSIG (w
) == SIGSTOP
2274 && current_inferior
->last_resume_kind
== resume_stop
))))
2276 siginfo_t info
, *info_p
;
2279 fprintf (stderr
, "Ignored signal %d for LWP %ld.\n",
2280 WSTOPSIG (w
), lwpid_of (event_child
));
2282 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (event_child
), 0, &info
) == 0)
2286 linux_resume_one_lwp (event_child
, event_child
->stepping
,
2287 WSTOPSIG (w
), info_p
);
2291 /* If GDB wanted this thread to single step, we always want to
2292 report the SIGTRAP, and let GDB handle it. Watchpoints should
2293 always be reported. So should signals we can't explain. A
2294 SIGTRAP we can't explain could be a GDB breakpoint --- we may or
2295 not support Z0 breakpoints. If we do, we're be able to handle
2296 GDB breakpoints on top of internal breakpoints, by handling the
2297 internal breakpoint and still reporting the event to GDB. If we
2298 don't, we're out of luck, GDB won't see the breakpoint hit. */
2299 report_to_gdb
= (!maybe_internal_trap
2300 || current_inferior
->last_resume_kind
== resume_step
2301 || event_child
->stopped_by_watchpoint
2302 || (!step_over_finished
&& !bp_explains_trap
&& !trace_event
)
2303 || gdb_breakpoint_here (event_child
->stop_pc
));
2305 /* We found no reason GDB would want us to stop. We either hit one
2306 of our own breakpoints, or finished an internal step GDB
2307 shouldn't know about. */
2312 if (bp_explains_trap
)
2313 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
2314 if (step_over_finished
)
2315 fprintf (stderr
, "Step-over finished.\n");
2317 fprintf (stderr
, "Tracepoint event.\n");
2320 /* We're not reporting this breakpoint to GDB, so apply the
2321 decr_pc_after_break adjustment to the inferior's regcache
2324 if (the_low_target
.set_pc
!= NULL
)
2326 struct regcache
*regcache
2327 = get_thread_regcache (get_lwp_thread (event_child
), 1);
2328 (*the_low_target
.set_pc
) (regcache
, event_child
->stop_pc
);
2331 /* We may have finished stepping over a breakpoint. If so,
2332 we've stopped and suspended all LWPs momentarily except the
2333 stepping one. This is where we resume them all again. We're
2334 going to keep waiting, so use proceed, which handles stepping
2335 over the next breakpoint. */
2337 fprintf (stderr
, "proceeding all threads.\n");
2339 if (step_over_finished
)
2340 unsuspend_all_lwps (event_child
);
2342 proceed_all_lwps ();
2348 if (current_inferior
->last_resume_kind
== resume_step
)
2349 fprintf (stderr
, "GDB wanted to single-step, reporting event.\n");
2350 if (event_child
->stopped_by_watchpoint
)
2351 fprintf (stderr
, "Stopped by watchpoint.\n");
2352 if (gdb_breakpoint_here (event_child
->stop_pc
))
2353 fprintf (stderr
, "Stopped by GDB breakpoint.\n");
2355 fprintf (stderr
, "Hit a non-gdbserver trap event.\n");
2358 /* Alright, we're going to report a stop. */
2360 if (!non_stop
&& !stabilizing_threads
)
2362 /* In all-stop, stop all threads. */
2363 stop_all_lwps (0, NULL
);
2365 /* If we're not waiting for a specific LWP, choose an event LWP
2366 from among those that have had events. Giving equal priority
2367 to all LWPs that have had events helps prevent
2369 if (ptid_equal (ptid
, minus_one_ptid
))
2371 event_child
->status_pending_p
= 1;
2372 event_child
->status_pending
= w
;
2374 select_event_lwp (&event_child
);
2376 event_child
->status_pending_p
= 0;
2377 w
= event_child
->status_pending
;
2380 /* Now that we've selected our final event LWP, cancel any
2381 breakpoints in other LWPs that have hit a GDB breakpoint.
2382 See the comment in cancel_breakpoints_callback to find out
2384 find_inferior (&all_lwps
, cancel_breakpoints_callback
, event_child
);
2386 /* Stabilize threads (move out of jump pads). */
2387 stabilize_threads ();
2391 /* If we just finished a step-over, then all threads had been
2392 momentarily paused. In all-stop, that's fine, we want
2393 threads stopped by now anyway. In non-stop, we need to
2394 re-resume threads that GDB wanted to be running. */
2395 if (step_over_finished
)
2396 unstop_all_lwps (1, event_child
);
2399 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
2401 if (current_inferior
->last_resume_kind
== resume_stop
2402 && WSTOPSIG (w
) == SIGSTOP
)
2404 /* A thread that has been requested to stop by GDB with vCont;t,
2405 and it stopped cleanly, so report as SIG0. The use of
2406 SIGSTOP is an implementation detail. */
2407 ourstatus
->value
.sig
= TARGET_SIGNAL_0
;
2409 else if (current_inferior
->last_resume_kind
== resume_stop
2410 && WSTOPSIG (w
) != SIGSTOP
)
2412 /* A thread that has been requested to stop by GDB with vCont;t,
2413 but, it stopped for other reasons. */
2414 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
2418 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
2421 gdb_assert (ptid_equal (step_over_bkpt
, null_ptid
));
2424 fprintf (stderr
, "linux_wait ret = %s, %d, %d\n",
2425 target_pid_to_str (ptid_of (event_child
)),
2427 ourstatus
->value
.sig
);
2429 return ptid_of (event_child
);
2432 /* Get rid of any pending event in the pipe. */
2434 async_file_flush (void)
2440 ret
= read (linux_event_pipe
[0], &buf
, 1);
2441 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
2444 /* Put something in the pipe, so the event loop wakes up. */
2446 async_file_mark (void)
2450 async_file_flush ();
2453 ret
= write (linux_event_pipe
[1], "+", 1);
2454 while (ret
== 0 || (ret
== -1 && errno
== EINTR
));
2456 /* Ignore EAGAIN. If the pipe is full, the event loop will already
2457 be awakened anyway. */
2461 linux_wait (ptid_t ptid
,
2462 struct target_waitstatus
*ourstatus
, int target_options
)
2467 fprintf (stderr
, "linux_wait: [%s]\n", target_pid_to_str (ptid
));
2469 /* Flush the async file first. */
2470 if (target_is_async_p ())
2471 async_file_flush ();
2473 event_ptid
= linux_wait_1 (ptid
, ourstatus
, target_options
);
2475 /* If at least one stop was reported, there may be more. A single
2476 SIGCHLD can signal more than one child stop. */
2477 if (target_is_async_p ()
2478 && (target_options
& TARGET_WNOHANG
) != 0
2479 && !ptid_equal (event_ptid
, null_ptid
))
2485 /* Send a signal to an LWP. */
2488 kill_lwp (unsigned long lwpid
, int signo
)
2490 /* Use tkill, if possible, in case we are using nptl threads. If tkill
2491 fails, then we are not using nptl threads and we should be using kill. */
2495 static int tkill_failed
;
2502 ret
= syscall (__NR_tkill
, lwpid
, signo
);
2503 if (errno
!= ENOSYS
)
2510 return kill (lwpid
, signo
);
2514 linux_stop_lwp (struct lwp_info
*lwp
)
2520 send_sigstop (struct lwp_info
*lwp
)
2524 pid
= lwpid_of (lwp
);
2526 /* If we already have a pending stop signal for this process, don't
2528 if (lwp
->stop_expected
)
2531 fprintf (stderr
, "Have pending sigstop for lwp %d\n", pid
);
2537 fprintf (stderr
, "Sending sigstop to lwp %d\n", pid
);
2539 lwp
->stop_expected
= 1;
2540 kill_lwp (pid
, SIGSTOP
);
2544 send_sigstop_callback (struct inferior_list_entry
*entry
, void *except
)
2546 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2548 /* Ignore EXCEPT. */
2559 /* Increment the suspend count of an LWP, and stop it, if not stopped
2562 suspend_and_send_sigstop_callback (struct inferior_list_entry
*entry
,
2565 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2567 /* Ignore EXCEPT. */
2573 return send_sigstop_callback (entry
, except
);
2577 mark_lwp_dead (struct lwp_info
*lwp
, int wstat
)
2579 /* It's dead, really. */
2582 /* Store the exit status for later. */
2583 lwp
->status_pending_p
= 1;
2584 lwp
->status_pending
= wstat
;
2586 /* Prevent trying to stop it. */
2589 /* No further stops are expected from a dead lwp. */
2590 lwp
->stop_expected
= 0;
2594 wait_for_sigstop (struct inferior_list_entry
*entry
)
2596 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2597 struct thread_info
*saved_inferior
;
2606 fprintf (stderr
, "wait_for_sigstop: LWP %ld already stopped\n",
2611 saved_inferior
= current_inferior
;
2612 if (saved_inferior
!= NULL
)
2613 saved_tid
= ((struct inferior_list_entry
*) saved_inferior
)->id
;
2615 saved_tid
= null_ptid
; /* avoid bogus unused warning */
2617 ptid
= lwp
->head
.id
;
2620 fprintf (stderr
, "wait_for_sigstop: pulling one event\n");
2622 pid
= linux_wait_for_event (ptid
, &wstat
, __WALL
);
2624 /* If we stopped with a non-SIGSTOP signal, save it for later
2625 and record the pending SIGSTOP. If the process exited, just
2627 if (WIFSTOPPED (wstat
))
2630 fprintf (stderr
, "LWP %ld stopped with signal %d\n",
2631 lwpid_of (lwp
), WSTOPSIG (wstat
));
2633 if (WSTOPSIG (wstat
) != SIGSTOP
)
2636 fprintf (stderr
, "LWP %ld stopped with non-sigstop status %06x\n",
2637 lwpid_of (lwp
), wstat
);
2639 lwp
->status_pending_p
= 1;
2640 lwp
->status_pending
= wstat
;
2646 fprintf (stderr
, "Process %d exited while stopping LWPs\n", pid
);
2648 lwp
= find_lwp_pid (pid_to_ptid (pid
));
2651 /* Leave this status pending for the next time we're able to
2652 report it. In the mean time, we'll report this lwp as
2653 dead to GDB, so GDB doesn't try to read registers and
2654 memory from it. This can only happen if this was the
2655 last thread of the process; otherwise, PID is removed
2656 from the thread tables before linux_wait_for_event
2658 mark_lwp_dead (lwp
, wstat
);
2662 if (saved_inferior
== NULL
|| linux_thread_alive (saved_tid
))
2663 current_inferior
= saved_inferior
;
2667 fprintf (stderr
, "Previously current thread died.\n");
2671 /* We can't change the current inferior behind GDB's back,
2672 otherwise, a subsequent command may apply to the wrong
2674 current_inferior
= NULL
;
2678 /* Set a valid thread as current. */
2679 set_desired_inferior (0);
2684 /* Returns true if LWP ENTRY is stopped in a jump pad, and we can't
2685 move it out, because we need to report the stop event to GDB. For
2686 example, if the user puts a breakpoint in the jump pad, it's
2687 because she wants to debug it. */
2690 stuck_in_jump_pad_callback (struct inferior_list_entry
*entry
, void *data
)
2692 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2693 struct thread_info
*thread
= get_lwp_thread (lwp
);
2695 gdb_assert (lwp
->suspended
== 0);
2696 gdb_assert (lwp
->stopped
);
2698 /* Allow debugging the jump pad, gdb_collect, etc.. */
2699 return (supports_fast_tracepoints ()
2700 && in_process_agent_loaded ()
2701 && (gdb_breakpoint_here (lwp
->stop_pc
)
2702 || lwp
->stopped_by_watchpoint
2703 || thread
->last_resume_kind
== resume_step
)
2704 && linux_fast_tracepoint_collecting (lwp
, NULL
));
2708 move_out_of_jump_pad_callback (struct inferior_list_entry
*entry
)
2710 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2711 struct thread_info
*thread
= get_lwp_thread (lwp
);
2714 gdb_assert (lwp
->suspended
== 0);
2715 gdb_assert (lwp
->stopped
);
2717 wstat
= lwp
->status_pending_p
? &lwp
->status_pending
: NULL
;
2719 /* Allow debugging the jump pad, gdb_collect, etc. */
2720 if (!gdb_breakpoint_here (lwp
->stop_pc
)
2721 && !lwp
->stopped_by_watchpoint
2722 && thread
->last_resume_kind
!= resume_step
2723 && maybe_move_out_of_jump_pad (lwp
, wstat
))
2727 "LWP %ld needs stabilizing (in jump pad)\n",
2732 lwp
->status_pending_p
= 0;
2733 enqueue_one_deferred_signal (lwp
, wstat
);
2737 "Signal %d for LWP %ld deferred "
2739 WSTOPSIG (*wstat
), lwpid_of (lwp
));
2742 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
2749 lwp_running (struct inferior_list_entry
*entry
, void *data
)
2751 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2760 /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
2761 If SUSPEND, then also increase the suspend count of every LWP,
2765 stop_all_lwps (int suspend
, struct lwp_info
*except
)
2767 stopping_threads
= 1;
2770 find_inferior (&all_lwps
, suspend_and_send_sigstop_callback
, except
);
2772 find_inferior (&all_lwps
, send_sigstop_callback
, except
);
2773 for_each_inferior (&all_lwps
, wait_for_sigstop
);
2774 stopping_threads
= 0;
2777 /* Resume execution of the inferior process.
2778 If STEP is nonzero, single-step it.
2779 If SIGNAL is nonzero, give it that signal. */
2782 linux_resume_one_lwp (struct lwp_info
*lwp
,
2783 int step
, int signal
, siginfo_t
*info
)
2785 struct thread_info
*saved_inferior
;
2786 int fast_tp_collecting
;
2788 if (lwp
->stopped
== 0)
2791 fast_tp_collecting
= lwp
->collecting_fast_tracepoint
;
2793 gdb_assert (!stabilizing_threads
|| fast_tp_collecting
);
2795 /* Cancel actions that rely on GDB not changing the PC (e.g., the
2796 user used the "jump" command, or "set $pc = foo"). */
2797 if (lwp
->stop_pc
!= get_pc (lwp
))
2799 /* Collecting 'while-stepping' actions doesn't make sense
2801 release_while_stepping_state_list (get_lwp_thread (lwp
));
2804 /* If we have pending signals or status, and a new signal, enqueue the
2805 signal. Also enqueue the signal if we are waiting to reinsert a
2806 breakpoint; it will be picked up again below. */
2808 && (lwp
->status_pending_p
2809 || lwp
->pending_signals
!= NULL
2810 || lwp
->bp_reinsert
!= 0
2811 || fast_tp_collecting
))
2813 struct pending_signals
*p_sig
;
2814 p_sig
= xmalloc (sizeof (*p_sig
));
2815 p_sig
->prev
= lwp
->pending_signals
;
2816 p_sig
->signal
= signal
;
2818 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
2820 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
2821 lwp
->pending_signals
= p_sig
;
2824 if (lwp
->status_pending_p
)
2827 fprintf (stderr
, "Not resuming lwp %ld (%s, signal %d, stop %s);"
2828 " has pending status\n",
2829 lwpid_of (lwp
), step
? "step" : "continue", signal
,
2830 lwp
->stop_expected
? "expected" : "not expected");
2834 saved_inferior
= current_inferior
;
2835 current_inferior
= get_lwp_thread (lwp
);
2838 fprintf (stderr
, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
2839 lwpid_of (lwp
), step
? "step" : "continue", signal
,
2840 lwp
->stop_expected
? "expected" : "not expected");
2842 /* This bit needs some thinking about. If we get a signal that
2843 we must report while a single-step reinsert is still pending,
2844 we often end up resuming the thread. It might be better to
2845 (ew) allow a stack of pending events; then we could be sure that
2846 the reinsert happened right away and not lose any signals.
2848 Making this stack would also shrink the window in which breakpoints are
2849 uninserted (see comment in linux_wait_for_lwp) but not enough for
2850 complete correctness, so it won't solve that problem. It may be
2851 worthwhile just to solve this one, however. */
2852 if (lwp
->bp_reinsert
!= 0)
2855 fprintf (stderr
, " pending reinsert at 0x%s\n",
2856 paddress (lwp
->bp_reinsert
));
2858 if (lwp
->bp_reinsert
!= 0 && can_hardware_single_step ())
2860 if (fast_tp_collecting
== 0)
2863 fprintf (stderr
, "BAD - reinserting but not stepping.\n");
2865 fprintf (stderr
, "BAD - reinserting and suspended(%d).\n",
2872 /* Postpone any pending signal. It was enqueued above. */
2876 if (fast_tp_collecting
== 1)
2880 lwp %ld wants to get out of fast tracepoint jump pad (exit-jump-pad-bkpt)\n",
2883 /* Postpone any pending signal. It was enqueued above. */
2886 else if (fast_tp_collecting
== 2)
2890 lwp %ld wants to get out of fast tracepoint jump pad single-stepping\n",
2893 if (can_hardware_single_step ())
2896 fatal ("moving out of jump pad single-stepping"
2897 " not implemented on this target");
2899 /* Postpone any pending signal. It was enqueued above. */
2903 /* If we have while-stepping actions in this thread set it stepping.
2904 If we have a signal to deliver, it may or may not be set to
2905 SIG_IGN, we don't know. Assume so, and allow collecting
2906 while-stepping into a signal handler. A possible smart thing to
2907 do would be to set an internal breakpoint at the signal return
2908 address, continue, and carry on catching this while-stepping
2909 action only when that breakpoint is hit. A future
2911 if (get_lwp_thread (lwp
)->while_stepping
!= NULL
2912 && can_hardware_single_step ())
2916 "lwp %ld has a while-stepping action -> forcing step.\n",
2921 if (debug_threads
&& the_low_target
.get_pc
!= NULL
)
2923 struct regcache
*regcache
= get_thread_regcache (current_inferior
, 1);
2924 CORE_ADDR pc
= (*the_low_target
.get_pc
) (regcache
);
2925 fprintf (stderr
, " resuming from pc 0x%lx\n", (long) pc
);
2928 /* If we have pending signals, consume one unless we are trying to
2929 reinsert a breakpoint or we're trying to finish a fast tracepoint
2931 if (lwp
->pending_signals
!= NULL
2932 && lwp
->bp_reinsert
== 0
2933 && fast_tp_collecting
== 0)
2935 struct pending_signals
**p_sig
;
2937 p_sig
= &lwp
->pending_signals
;
2938 while ((*p_sig
)->prev
!= NULL
)
2939 p_sig
= &(*p_sig
)->prev
;
2941 signal
= (*p_sig
)->signal
;
2942 if ((*p_sig
)->info
.si_signo
!= 0)
2943 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &(*p_sig
)->info
);
2949 if (the_low_target
.prepare_to_resume
!= NULL
)
2950 the_low_target
.prepare_to_resume (lwp
);
2952 regcache_invalidate_one ((struct inferior_list_entry
*)
2953 get_lwp_thread (lwp
));
2956 lwp
->stopped_by_watchpoint
= 0;
2957 lwp
->stepping
= step
;
2958 ptrace (step
? PTRACE_SINGLESTEP
: PTRACE_CONT
, lwpid_of (lwp
), 0,
2959 /* Coerce to a uintptr_t first to avoid potential gcc warning
2960 of coercing an 8 byte integer to a 4 byte pointer. */
2961 (PTRACE_ARG4_TYPE
) (uintptr_t) signal
);
2963 current_inferior
= saved_inferior
;
2966 /* ESRCH from ptrace either means that the thread was already
2967 running (an error) or that it is gone (a race condition). If
2968 it's gone, we will get a notification the next time we wait,
2969 so we can ignore the error. We could differentiate these
2970 two, but it's tricky without waiting; the thread still exists
2971 as a zombie, so sending it signal 0 would succeed. So just
2976 perror_with_name ("ptrace");
2980 struct thread_resume_array
2982 struct thread_resume
*resume
;
2986 /* This function is called once per thread. We look up the thread
2987 in RESUME_PTR, and mark the thread with a pointer to the appropriate
2990 This algorithm is O(threads * resume elements), but resume elements
2991 is small (and will remain small at least until GDB supports thread
2994 linux_set_resume_request (struct inferior_list_entry
*entry
, void *arg
)
2996 struct lwp_info
*lwp
;
2997 struct thread_info
*thread
;
2999 struct thread_resume_array
*r
;
3001 thread
= (struct thread_info
*) entry
;
3002 lwp
= get_thread_lwp (thread
);
3005 for (ndx
= 0; ndx
< r
->n
; ndx
++)
3007 ptid_t ptid
= r
->resume
[ndx
].thread
;
3008 if (ptid_equal (ptid
, minus_one_ptid
)
3009 || ptid_equal (ptid
, entry
->id
)
3010 || (ptid_is_pid (ptid
)
3011 && (ptid_get_pid (ptid
) == pid_of (lwp
)))
3012 || (ptid_get_lwp (ptid
) == -1
3013 && (ptid_get_pid (ptid
) == pid_of (lwp
))))
3015 if (r
->resume
[ndx
].kind
== resume_stop
3016 && thread
->last_resume_kind
== resume_stop
)
3019 fprintf (stderr
, "already %s LWP %ld at GDB's request\n",
3020 thread
->last_status
.kind
== TARGET_WAITKIND_STOPPED
3028 lwp
->resume
= &r
->resume
[ndx
];
3029 thread
->last_resume_kind
= lwp
->resume
->kind
;
3031 /* If we had a deferred signal to report, dequeue one now.
3032 This can happen if LWP gets more than one signal while
3033 trying to get out of a jump pad. */
3035 && !lwp
->status_pending_p
3036 && dequeue_one_deferred_signal (lwp
, &lwp
->status_pending
))
3038 lwp
->status_pending_p
= 1;
3042 "Dequeueing deferred signal %d for LWP %ld, "
3043 "leaving status pending.\n",
3044 WSTOPSIG (lwp
->status_pending
), lwpid_of (lwp
));
3051 /* No resume action for this thread. */
3058 /* Set *FLAG_P if this lwp has an interesting status pending. */
3060 resume_status_pending_p (struct inferior_list_entry
*entry
, void *flag_p
)
3062 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
3064 /* LWPs which will not be resumed are not interesting, because
3065 we might not wait for them next time through linux_wait. */
3066 if (lwp
->resume
== NULL
)
3069 if (lwp
->status_pending_p
)
3070 * (int *) flag_p
= 1;
3075 /* Return 1 if this lwp that GDB wants running is stopped at an
3076 internal breakpoint that we need to step over. It assumes that any
3077 required STOP_PC adjustment has already been propagated to the
3078 inferior's regcache. */
3081 need_step_over_p (struct inferior_list_entry
*entry
, void *dummy
)
3083 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
3084 struct thread_info
*thread
;
3085 struct thread_info
*saved_inferior
;
3088 /* LWPs which will not be resumed are not interesting, because we
3089 might not wait for them next time through linux_wait. */
3095 "Need step over [LWP %ld]? Ignoring, not stopped\n",
3100 thread
= get_lwp_thread (lwp
);
3102 if (thread
->last_resume_kind
== resume_stop
)
3106 "Need step over [LWP %ld]? Ignoring, should remain stopped\n",
3111 gdb_assert (lwp
->suspended
>= 0);
3117 "Need step over [LWP %ld]? Ignoring, suspended\n",
3122 if (!lwp
->need_step_over
)
3126 "Need step over [LWP %ld]? No\n", lwpid_of (lwp
));
3129 if (lwp
->status_pending_p
)
3133 "Need step over [LWP %ld]? Ignoring, has pending status.\n",
3138 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
3142 /* If the PC has changed since we stopped, then don't do anything,
3143 and let the breakpoint/tracepoint be hit. This happens if, for
3144 instance, GDB handled the decr_pc_after_break subtraction itself,
3145 GDB is OOL stepping this thread, or the user has issued a "jump"
3146 command, or poked thread's registers herself. */
3147 if (pc
!= lwp
->stop_pc
)
3151 "Need step over [LWP %ld]? Cancelling, PC was changed. "
3152 "Old stop_pc was 0x%s, PC is now 0x%s\n",
3153 lwpid_of (lwp
), paddress (lwp
->stop_pc
), paddress (pc
));
3155 lwp
->need_step_over
= 0;
3159 saved_inferior
= current_inferior
;
3160 current_inferior
= thread
;
3162 /* We can only step over breakpoints we know about. */
3163 if (breakpoint_here (pc
) || fast_tracepoint_jump_here (pc
))
3165 /* Don't step over a breakpoint that GDB expects to hit
3167 if (gdb_breakpoint_here (pc
))
3171 "Need step over [LWP %ld]? yes, but found"
3172 " GDB breakpoint at 0x%s; skipping step over\n",
3173 lwpid_of (lwp
), paddress (pc
));
3175 current_inferior
= saved_inferior
;
3182 "Need step over [LWP %ld]? yes, found breakpoint at 0x%s\n",
3183 lwpid_of (lwp
), paddress (pc
));
3185 /* We've found an lwp that needs stepping over --- return 1 so
3186 that find_inferior stops looking. */
3187 current_inferior
= saved_inferior
;
3189 /* If the step over is cancelled, this is set again. */
3190 lwp
->need_step_over
= 0;
3195 current_inferior
= saved_inferior
;
3199 "Need step over [LWP %ld]? No, no breakpoint found at 0x%s\n",
3200 lwpid_of (lwp
), paddress (pc
));
3205 /* Start a step-over operation on LWP. When LWP stopped at a
3206 breakpoint, to make progress, we need to remove the breakpoint out
3207 of the way. If we let other threads run while we do that, they may
3208 pass by the breakpoint location and miss hitting it. To avoid
3209 that, a step-over momentarily stops all threads while LWP is
3210 single-stepped while the breakpoint is temporarily uninserted from
3211 the inferior. When the single-step finishes, we reinsert the
3212 breakpoint, and let all threads that are supposed to be running,
3215 On targets that don't support hardware single-step, we don't
3216 currently support full software single-stepping. Instead, we only
3217 support stepping over the thread event breakpoint, by asking the
3218 low target where to place a reinsert breakpoint. Since this
3219 routine assumes the breakpoint being stepped over is a thread event
3220 breakpoint, it usually assumes the return address of the current
3221 function is a good enough place to set the reinsert breakpoint. */
3224 start_step_over (struct lwp_info
*lwp
)
3226 struct thread_info
*saved_inferior
;
3232 "Starting step-over on LWP %ld. Stopping all threads\n",
3235 stop_all_lwps (1, lwp
);
3236 gdb_assert (lwp
->suspended
== 0);
3239 fprintf (stderr
, "Done stopping all threads for step-over.\n");
3241 /* Note, we should always reach here with an already adjusted PC,
3242 either by GDB (if we're resuming due to GDB's request), or by our
3243 caller, if we just finished handling an internal breakpoint GDB
3244 shouldn't care about. */
3247 saved_inferior
= current_inferior
;
3248 current_inferior
= get_lwp_thread (lwp
);
3250 lwp
->bp_reinsert
= pc
;
3251 uninsert_breakpoints_at (pc
);
3252 uninsert_fast_tracepoint_jumps_at (pc
);
3254 if (can_hardware_single_step ())
3260 CORE_ADDR raddr
= (*the_low_target
.breakpoint_reinsert_addr
) ();
3261 set_reinsert_breakpoint (raddr
);
3265 current_inferior
= saved_inferior
;
3267 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
3269 /* Require next event from this LWP. */
3270 step_over_bkpt
= lwp
->head
.id
;
3274 /* Finish a step-over. Reinsert the breakpoint we had uninserted in
3275 start_step_over, if still there, and delete any reinsert
3276 breakpoints we've set, on non hardware single-step targets. */
3279 finish_step_over (struct lwp_info
*lwp
)
3281 if (lwp
->bp_reinsert
!= 0)
3284 fprintf (stderr
, "Finished step over.\n");
3286 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
3287 may be no breakpoint to reinsert there by now. */
3288 reinsert_breakpoints_at (lwp
->bp_reinsert
);
3289 reinsert_fast_tracepoint_jumps_at (lwp
->bp_reinsert
);
3291 lwp
->bp_reinsert
= 0;
3293 /* Delete any software-single-step reinsert breakpoints. No
3294 longer needed. We don't have to worry about other threads
3295 hitting this trap, and later not being able to explain it,
3296 because we were stepping over a breakpoint, and we hold all
3297 threads but LWP stopped while doing that. */
3298 if (!can_hardware_single_step ())
3299 delete_reinsert_breakpoints ();
3301 step_over_bkpt
= null_ptid
;
3308 /* This function is called once per thread. We check the thread's resume
3309 request, which will tell us whether to resume, step, or leave the thread
3310 stopped; and what signal, if any, it should be sent.
3312 For threads which we aren't explicitly told otherwise, we preserve
3313 the stepping flag; this is used for stepping over gdbserver-placed
3316 If pending_flags was set in any thread, we queue any needed
3317 signals, since we won't actually resume. We already have a pending
3318 event to report, so we don't need to preserve any step requests;
3319 they should be re-issued if necessary. */
3322 linux_resume_one_thread (struct inferior_list_entry
*entry
, void *arg
)
3324 struct lwp_info
*lwp
;
3325 struct thread_info
*thread
;
3327 int leave_all_stopped
= * (int *) arg
;
3330 thread
= (struct thread_info
*) entry
;
3331 lwp
= get_thread_lwp (thread
);
3333 if (lwp
->resume
== NULL
)
3336 if (lwp
->resume
->kind
== resume_stop
)
3339 fprintf (stderr
, "resume_stop request for LWP %ld\n", lwpid_of (lwp
));
3344 fprintf (stderr
, "stopping LWP %ld\n", lwpid_of (lwp
));
3346 /* Stop the thread, and wait for the event asynchronously,
3347 through the event loop. */
3353 fprintf (stderr
, "already stopped LWP %ld\n",
3356 /* The LWP may have been stopped in an internal event that
3357 was not meant to be notified back to GDB (e.g., gdbserver
3358 breakpoint), so we should be reporting a stop event in
3361 /* If the thread already has a pending SIGSTOP, this is a
3362 no-op. Otherwise, something later will presumably resume
3363 the thread and this will cause it to cancel any pending
3364 operation, due to last_resume_kind == resume_stop. If
3365 the thread already has a pending status to report, we
3366 will still report it the next time we wait - see
3367 status_pending_p_callback. */
3369 /* If we already have a pending signal to report, then
3370 there's no need to queue a SIGSTOP, as this means we're
3371 midway through moving the LWP out of the jumppad, and we
3372 will report the pending signal as soon as that is
3374 if (lwp
->pending_signals_to_report
== NULL
)
3378 /* For stop requests, we're done. */
3380 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
3384 /* If this thread which is about to be resumed has a pending status,
3385 then don't resume any threads - we can just report the pending
3386 status. Make sure to queue any signals that would otherwise be
3387 sent. In all-stop mode, we do this decision based on if *any*
3388 thread has a pending status. If there's a thread that needs the
3389 step-over-breakpoint dance, then don't resume any other thread
3390 but that particular one. */
3391 leave_pending
= (lwp
->status_pending_p
|| leave_all_stopped
);
3396 fprintf (stderr
, "resuming LWP %ld\n", lwpid_of (lwp
));
3398 step
= (lwp
->resume
->kind
== resume_step
);
3399 linux_resume_one_lwp (lwp
, step
, lwp
->resume
->sig
, NULL
);
3404 fprintf (stderr
, "leaving LWP %ld stopped\n", lwpid_of (lwp
));
3406 /* If we have a new signal, enqueue the signal. */
3407 if (lwp
->resume
->sig
!= 0)
3409 struct pending_signals
*p_sig
;
3410 p_sig
= xmalloc (sizeof (*p_sig
));
3411 p_sig
->prev
= lwp
->pending_signals
;
3412 p_sig
->signal
= lwp
->resume
->sig
;
3413 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
3415 /* If this is the same signal we were previously stopped by,
3416 make sure to queue its siginfo. We can ignore the return
3417 value of ptrace; if it fails, we'll skip
3418 PTRACE_SETSIGINFO. */
3419 if (WIFSTOPPED (lwp
->last_status
)
3420 && WSTOPSIG (lwp
->last_status
) == lwp
->resume
->sig
)
3421 ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &p_sig
->info
);
3423 lwp
->pending_signals
= p_sig
;
3427 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
3433 linux_resume (struct thread_resume
*resume_info
, size_t n
)
3435 struct thread_resume_array array
= { resume_info
, n
};
3436 struct lwp_info
*need_step_over
= NULL
;
3438 int leave_all_stopped
;
3440 find_inferior (&all_threads
, linux_set_resume_request
, &array
);
3442 /* If there is a thread which would otherwise be resumed, which has
3443 a pending status, then don't resume any threads - we can just
3444 report the pending status. Make sure to queue any signals that
3445 would otherwise be sent. In non-stop mode, we'll apply this
3446 logic to each thread individually. We consume all pending events
3447 before considering to start a step-over (in all-stop). */
3450 find_inferior (&all_lwps
, resume_status_pending_p
, &any_pending
);
3452 /* If there is a thread which would otherwise be resumed, which is
3453 stopped at a breakpoint that needs stepping over, then don't
3454 resume any threads - have it step over the breakpoint with all
3455 other threads stopped, then resume all threads again. Make sure
3456 to queue any signals that would otherwise be delivered or
3458 if (!any_pending
&& supports_breakpoints ())
3460 = (struct lwp_info
*) find_inferior (&all_lwps
,
3461 need_step_over_p
, NULL
);
3463 leave_all_stopped
= (need_step_over
!= NULL
|| any_pending
);
3467 if (need_step_over
!= NULL
)
3468 fprintf (stderr
, "Not resuming all, need step over\n");
3469 else if (any_pending
)
3471 "Not resuming, all-stop and found "
3472 "an LWP with pending status\n");
3474 fprintf (stderr
, "Resuming, no pending status or step over needed\n");
3477 /* Even if we're leaving threads stopped, queue all signals we'd
3478 otherwise deliver. */
3479 find_inferior (&all_threads
, linux_resume_one_thread
, &leave_all_stopped
);
3482 start_step_over (need_step_over
);
3485 /* This function is called once per thread. We check the thread's
3486 last resume request, which will tell us whether to resume, step, or
3487 leave the thread stopped. Any signal the client requested to be
3488 delivered has already been enqueued at this point.
3490 If any thread that GDB wants running is stopped at an internal
3491 breakpoint that needs stepping over, we start a step-over operation
3492 on that particular thread, and leave all others stopped. */
3495 proceed_one_lwp (struct inferior_list_entry
*entry
, void *except
)
3497 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
3498 struct thread_info
*thread
;
3506 "proceed_one_lwp: lwp %ld\n", lwpid_of (lwp
));
3511 fprintf (stderr
, " LWP %ld already running\n", lwpid_of (lwp
));
3515 thread
= get_lwp_thread (lwp
);
3517 if (thread
->last_resume_kind
== resume_stop
3518 && thread
->last_status
.kind
!= TARGET_WAITKIND_IGNORE
)
3521 fprintf (stderr
, " client wants LWP to remain %ld stopped\n",
3526 if (lwp
->status_pending_p
)
3529 fprintf (stderr
, " LWP %ld has pending status, leaving stopped\n",
3534 gdb_assert (lwp
->suspended
>= 0);
3539 fprintf (stderr
, " LWP %ld is suspended\n", lwpid_of (lwp
));
3543 if (thread
->last_resume_kind
== resume_stop
3544 && lwp
->pending_signals_to_report
== NULL
3545 && lwp
->collecting_fast_tracepoint
== 0)
3547 /* We haven't reported this LWP as stopped yet (otherwise, the
3548 last_status.kind check above would catch it, and we wouldn't
3549 reach here. This LWP may have been momentarily paused by a
3550 stop_all_lwps call while handling for example, another LWP's
3551 step-over. In that case, the pending expected SIGSTOP signal
3552 that was queued at vCont;t handling time will have already
3553 been consumed by wait_for_sigstop, and so we need to requeue
3554 another one here. Note that if the LWP already has a SIGSTOP
3555 pending, this is a no-op. */
3559 "Client wants LWP %ld to stop. "
3560 "Making sure it has a SIGSTOP pending\n",
3566 step
= thread
->last_resume_kind
== resume_step
;
3567 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
3572 unsuspend_and_proceed_one_lwp (struct inferior_list_entry
*entry
, void *except
)
3574 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
3580 gdb_assert (lwp
->suspended
>= 0);
3582 return proceed_one_lwp (entry
, except
);
3585 /* When we finish a step-over, set threads running again. If there's
3586 another thread that may need a step-over, now's the time to start
3587 it. Eventually, we'll move all threads past their breakpoints. */
3590 proceed_all_lwps (void)
3592 struct lwp_info
*need_step_over
;
3594 /* If there is a thread which would otherwise be resumed, which is
3595 stopped at a breakpoint that needs stepping over, then don't
3596 resume any threads - have it step over the breakpoint with all
3597 other threads stopped, then resume all threads again. */
3599 if (supports_breakpoints ())
3602 = (struct lwp_info
*) find_inferior (&all_lwps
,
3603 need_step_over_p
, NULL
);
3605 if (need_step_over
!= NULL
)
3608 fprintf (stderr
, "proceed_all_lwps: found "
3609 "thread %ld needing a step-over\n",
3610 lwpid_of (need_step_over
));
3612 start_step_over (need_step_over
);
3618 fprintf (stderr
, "Proceeding, no step-over needed\n");
3620 find_inferior (&all_lwps
, proceed_one_lwp
, NULL
);
3623 /* Stopped LWPs that the client wanted to be running, that don't have
3624 pending statuses, are set to run again, except for EXCEPT, if not
3625 NULL. This undoes a stop_all_lwps call. */
3628 unstop_all_lwps (int unsuspend
, struct lwp_info
*except
)
3634 "unstopping all lwps, except=(LWP %ld)\n", lwpid_of (except
));
3637 "unstopping all lwps\n");
3641 find_inferior (&all_lwps
, unsuspend_and_proceed_one_lwp
, except
);
3643 find_inferior (&all_lwps
, proceed_one_lwp
, except
);
3646 #ifdef HAVE_LINUX_USRREGS
3649 register_addr (int regnum
)
3653 if (regnum
< 0 || regnum
>= the_low_target
.num_regs
)
3654 error ("Invalid register number %d.", regnum
);
3656 addr
= the_low_target
.regmap
[regnum
];
3661 /* Fetch one register. */
3663 fetch_register (struct regcache
*regcache
, int regno
)
3670 if (regno
>= the_low_target
.num_regs
)
3672 if ((*the_low_target
.cannot_fetch_register
) (regno
))
3675 regaddr
= register_addr (regno
);
3679 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3680 size
= ((register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
3681 & - sizeof (PTRACE_XFER_TYPE
));
3682 buf
= alloca (size
);
3683 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
3686 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
3687 ptrace (PTRACE_PEEKUSER
, pid
,
3688 /* Coerce to a uintptr_t first to avoid potential gcc warning
3689 of coercing an 8 byte integer to a 4 byte pointer. */
3690 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
, 0);
3691 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
3693 error ("reading register %d: %s", regno
, strerror (errno
));
3696 if (the_low_target
.supply_ptrace_register
)
3697 the_low_target
.supply_ptrace_register (regcache
, regno
, buf
);
3699 supply_register (regcache
, regno
, buf
);
3702 /* Fetch all registers, or just one, from the child process. */
3704 usr_fetch_inferior_registers (struct regcache
*regcache
, int regno
)
3707 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
3708 fetch_register (regcache
, regno
);
3710 fetch_register (regcache
, regno
);
3713 /* Store our register values back into the inferior.
3714 If REGNO is -1, do this for all registers.
3715 Otherwise, REGNO specifies which register (so we can save time). */
3717 usr_store_inferior_registers (struct regcache
*regcache
, int regno
)
3726 if (regno
>= the_low_target
.num_regs
)
3729 if ((*the_low_target
.cannot_store_register
) (regno
) == 1)
3732 regaddr
= register_addr (regno
);
3736 size
= (register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
3737 & - sizeof (PTRACE_XFER_TYPE
);
3738 buf
= alloca (size
);
3739 memset (buf
, 0, size
);
3741 if (the_low_target
.collect_ptrace_register
)
3742 the_low_target
.collect_ptrace_register (regcache
, regno
, buf
);
3744 collect_register (regcache
, regno
, buf
);
3746 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3747 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
3750 ptrace (PTRACE_POKEUSER
, pid
,
3751 /* Coerce to a uintptr_t first to avoid potential gcc warning
3752 about coercing an 8 byte integer to a 4 byte pointer. */
3753 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
,
3754 (PTRACE_ARG4_TYPE
) *(PTRACE_XFER_TYPE
*) (buf
+ i
));
3757 /* At this point, ESRCH should mean the process is
3758 already gone, in which case we simply ignore attempts
3759 to change its registers. See also the related
3760 comment in linux_resume_one_lwp. */
3764 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
3765 error ("writing register %d: %s", regno
, strerror (errno
));
3767 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
3771 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
3772 usr_store_inferior_registers (regcache
, regno
);
3774 #endif /* HAVE_LINUX_USRREGS */
3778 #ifdef HAVE_LINUX_REGSETS
3781 regsets_fetch_inferior_registers (struct regcache
*regcache
)
3783 struct regset_info
*regset
;
3784 int saw_general_regs
= 0;
3788 regset
= target_regsets
;
3790 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3791 while (regset
->size
>= 0)
3796 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
3802 buf
= xmalloc (regset
->size
);
3804 nt_type
= regset
->nt_type
;
3808 iov
.iov_len
= regset
->size
;
3809 data
= (void *) &iov
;
3815 res
= ptrace (regset
->get_request
, pid
, nt_type
, data
);
3817 res
= ptrace (regset
->get_request
, pid
, data
, nt_type
);
3823 /* If we get EIO on a regset, do not try it again for
3825 disabled_regsets
[regset
- target_regsets
] = 1;
3832 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%d",
3837 else if (regset
->type
== GENERAL_REGS
)
3838 saw_general_regs
= 1;
3839 regset
->store_function (regcache
, buf
);
3843 if (saw_general_regs
)
3850 regsets_store_inferior_registers (struct regcache
*regcache
)
3852 struct regset_info
*regset
;
3853 int saw_general_regs
= 0;
3857 regset
= target_regsets
;
3859 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3860 while (regset
->size
>= 0)
3865 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
3871 buf
= xmalloc (regset
->size
);
3873 /* First fill the buffer with the current register set contents,
3874 in case there are any items in the kernel's regset that are
3875 not in gdbserver's regcache. */
3877 nt_type
= regset
->nt_type
;
3881 iov
.iov_len
= regset
->size
;
3882 data
= (void *) &iov
;
3888 res
= ptrace (regset
->get_request
, pid
, nt_type
, data
);
3890 res
= ptrace (regset
->get_request
, pid
, &iov
, data
);
3895 /* Then overlay our cached registers on that. */
3896 regset
->fill_function (regcache
, buf
);
3898 /* Only now do we write the register set. */
3900 res
= ptrace (regset
->set_request
, pid
, nt_type
, data
);
3902 res
= ptrace (regset
->set_request
, pid
, data
, nt_type
);
3910 /* If we get EIO on a regset, do not try it again for
3912 disabled_regsets
[regset
- target_regsets
] = 1;
3916 else if (errno
== ESRCH
)
3918 /* At this point, ESRCH should mean the process is
3919 already gone, in which case we simply ignore attempts
3920 to change its registers. See also the related
3921 comment in linux_resume_one_lwp. */
3927 perror ("Warning: ptrace(regsets_store_inferior_registers)");
3930 else if (regset
->type
== GENERAL_REGS
)
3931 saw_general_regs
= 1;
3935 if (saw_general_regs
)
3942 #endif /* HAVE_LINUX_REGSETS */
3946 linux_fetch_registers (struct regcache
*regcache
, int regno
)
3948 #ifdef HAVE_LINUX_REGSETS
3949 if (regsets_fetch_inferior_registers (regcache
) == 0)
3952 #ifdef HAVE_LINUX_USRREGS
3953 usr_fetch_inferior_registers (regcache
, regno
);
3958 linux_store_registers (struct regcache
*regcache
, int regno
)
3960 #ifdef HAVE_LINUX_REGSETS
3961 if (regsets_store_inferior_registers (regcache
) == 0)
3964 #ifdef HAVE_LINUX_USRREGS
3965 usr_store_inferior_registers (regcache
, regno
);
3970 /* Copy LEN bytes from inferior's memory starting at MEMADDR
3971 to debugger memory starting at MYADDR. */
3974 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
3977 /* Round starting address down to longword boundary. */
3978 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
3979 /* Round ending address up; get number of longwords that makes. */
3981 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
3982 / sizeof (PTRACE_XFER_TYPE
);
3983 /* Allocate buffer of that many longwords. */
3984 register PTRACE_XFER_TYPE
*buffer
3985 = (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
3988 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3990 /* Try using /proc. Don't bother for one word. */
3991 if (len
>= 3 * sizeof (long))
3993 /* We could keep this file open and cache it - possibly one per
3994 thread. That requires some juggling, but is even faster. */
3995 sprintf (filename
, "/proc/%d/mem", pid
);
3996 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
4000 /* If pread64 is available, use it. It's faster if the kernel
4001 supports it (only one syscall), and it's 64-bit safe even on
4002 32-bit platforms (for instance, SPARC debugging a SPARC64
4005 if (pread64 (fd
, myaddr
, len
, memaddr
) != len
)
4007 if (lseek (fd
, memaddr
, SEEK_SET
) == -1 || read (fd
, myaddr
, len
) != len
)
4019 /* Read all the longwords */
4020 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
4023 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
4024 about coercing an 8 byte integer to a 4 byte pointer. */
4025 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, pid
,
4026 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
4031 /* Copy appropriate bytes out of the buffer. */
4033 (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
4039 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
4040 memory at MEMADDR. On failure (cannot write to the inferior)
4041 returns the value of errno. */
4044 linux_write_memory (CORE_ADDR memaddr
, const unsigned char *myaddr
, int len
)
4047 /* Round starting address down to longword boundary. */
4048 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
4049 /* Round ending address up; get number of longwords that makes. */
4051 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1) / sizeof (PTRACE_XFER_TYPE
);
4052 /* Allocate buffer of that many longwords. */
4053 register PTRACE_XFER_TYPE
*buffer
= (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
4054 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
4058 /* Dump up to four bytes. */
4059 unsigned int val
= * (unsigned int *) myaddr
;
4065 val
= val
& 0xffffff;
4066 fprintf (stderr
, "Writing %0*x to 0x%08lx\n", 2 * ((len
< 4) ? len
: 4),
4067 val
, (long)memaddr
);
4070 /* Fill start and end extra bytes of buffer with existing memory data. */
4073 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
4074 about coercing an 8 byte integer to a 4 byte pointer. */
4075 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, pid
,
4076 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
4084 = ptrace (PTRACE_PEEKTEXT
, pid
,
4085 /* Coerce to a uintptr_t first to avoid potential gcc warning
4086 about coercing an 8 byte integer to a 4 byte pointer. */
4087 (PTRACE_ARG3_TYPE
) (uintptr_t) (addr
+ (count
- 1)
4088 * sizeof (PTRACE_XFER_TYPE
)),
4094 /* Copy data to be written over corresponding part of buffer. */
4096 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)), myaddr
, len
);
4098 /* Write the entire buffer. */
4100 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
4103 ptrace (PTRACE_POKETEXT
, pid
,
4104 /* Coerce to a uintptr_t first to avoid potential gcc warning
4105 about coercing an 8 byte integer to a 4 byte pointer. */
4106 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
,
4107 (PTRACE_ARG4_TYPE
) buffer
[i
]);
4115 /* Non-zero if the kernel supports PTRACE_O_TRACEFORK. */
4116 static int linux_supports_tracefork_flag
;
4119 linux_enable_event_reporting (int pid
)
4121 if (!linux_supports_tracefork_flag
)
4124 ptrace (PTRACE_SETOPTIONS
, pid
, 0, (PTRACE_ARG4_TYPE
) PTRACE_O_TRACECLONE
);
4127 /* Helper functions for linux_test_for_tracefork, called via clone (). */
4130 linux_tracefork_grandchild (void *arg
)
4135 #define STACK_SIZE 4096
4138 linux_tracefork_child (void *arg
)
4140 ptrace (PTRACE_TRACEME
, 0, 0, 0);
4141 kill (getpid (), SIGSTOP
);
4143 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
4146 linux_tracefork_grandchild (NULL
);
4148 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4151 __clone2 (linux_tracefork_grandchild
, arg
, STACK_SIZE
,
4152 CLONE_VM
| SIGCHLD
, NULL
);
4154 clone (linux_tracefork_grandchild
, arg
+ STACK_SIZE
,
4155 CLONE_VM
| SIGCHLD
, NULL
);
4158 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4163 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
4164 sure that we can enable the option, and that it had the desired
4168 linux_test_for_tracefork (void)
4170 int child_pid
, ret
, status
;
4172 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4173 char *stack
= xmalloc (STACK_SIZE
* 4);
4174 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4176 linux_supports_tracefork_flag
= 0;
4178 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
4180 child_pid
= fork ();
4182 linux_tracefork_child (NULL
);
4184 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4186 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
4188 child_pid
= __clone2 (linux_tracefork_child
, stack
, STACK_SIZE
,
4189 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
4190 #else /* !__ia64__ */
4191 child_pid
= clone (linux_tracefork_child
, stack
+ STACK_SIZE
,
4192 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
4193 #endif /* !__ia64__ */
4195 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4197 if (child_pid
== -1)
4198 perror_with_name ("clone");
4200 ret
= my_waitpid (child_pid
, &status
, 0);
4202 perror_with_name ("waitpid");
4203 else if (ret
!= child_pid
)
4204 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret
);
4205 if (! WIFSTOPPED (status
))
4206 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status
);
4208 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0,
4209 (PTRACE_ARG4_TYPE
) PTRACE_O_TRACEFORK
);
4212 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
4215 warning ("linux_test_for_tracefork: failed to kill child");
4219 ret
= my_waitpid (child_pid
, &status
, 0);
4220 if (ret
!= child_pid
)
4221 warning ("linux_test_for_tracefork: failed to wait for killed child");
4222 else if (!WIFSIGNALED (status
))
4223 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
4224 "killed child", status
);
4229 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
4231 warning ("linux_test_for_tracefork: failed to resume child");
4233 ret
= my_waitpid (child_pid
, &status
, 0);
4235 if (ret
== child_pid
&& WIFSTOPPED (status
)
4236 && status
>> 16 == PTRACE_EVENT_FORK
)
4239 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
4240 if (ret
== 0 && second_pid
!= 0)
4244 linux_supports_tracefork_flag
= 1;
4245 my_waitpid (second_pid
, &second_status
, 0);
4246 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
4248 warning ("linux_test_for_tracefork: failed to kill second child");
4249 my_waitpid (second_pid
, &status
, 0);
4253 warning ("linux_test_for_tracefork: unexpected result from waitpid "
4254 "(%d, status 0x%x)", ret
, status
);
4258 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
4260 warning ("linux_test_for_tracefork: failed to kill child");
4261 my_waitpid (child_pid
, &status
, 0);
4263 while (WIFSTOPPED (status
));
4265 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4267 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4272 linux_look_up_symbols (void)
4274 #ifdef USE_THREAD_DB
4275 struct process_info
*proc
= current_process ();
4277 if (proc
->private->thread_db
!= NULL
)
4280 /* If the kernel supports tracing forks then it also supports tracing
4281 clones, and then we don't need to use the magic thread event breakpoint
4282 to learn about threads. */
4283 thread_db_init (!linux_supports_tracefork_flag
);
4288 linux_request_interrupt (void)
4290 extern unsigned long signal_pid
;
4292 if (!ptid_equal (cont_thread
, null_ptid
)
4293 && !ptid_equal (cont_thread
, minus_one_ptid
))
4295 struct lwp_info
*lwp
;
4298 lwp
= get_thread_lwp (current_inferior
);
4299 lwpid
= lwpid_of (lwp
);
4300 kill_lwp (lwpid
, SIGINT
);
4303 kill_lwp (signal_pid
, SIGINT
);
4306 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
4307 to debugger memory starting at MYADDR. */
4310 linux_read_auxv (CORE_ADDR offset
, unsigned char *myaddr
, unsigned int len
)
4312 char filename
[PATH_MAX
];
4314 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
4316 xsnprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
4318 fd
= open (filename
, O_RDONLY
);
4322 if (offset
!= (CORE_ADDR
) 0
4323 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4326 n
= read (fd
, myaddr
, len
);
4333 /* These breakpoint and watchpoint related wrapper functions simply
4334 pass on the function call if the target has registered a
4335 corresponding function. */
4338 linux_insert_point (char type
, CORE_ADDR addr
, int len
)
4340 if (the_low_target
.insert_point
!= NULL
)
4341 return the_low_target
.insert_point (type
, addr
, len
);
4343 /* Unsupported (see target.h). */
4348 linux_remove_point (char type
, CORE_ADDR addr
, int len
)
4350 if (the_low_target
.remove_point
!= NULL
)
4351 return the_low_target
.remove_point (type
, addr
, len
);
4353 /* Unsupported (see target.h). */
4358 linux_stopped_by_watchpoint (void)
4360 struct lwp_info
*lwp
= get_thread_lwp (current_inferior
);
4362 return lwp
->stopped_by_watchpoint
;
4366 linux_stopped_data_address (void)
4368 struct lwp_info
*lwp
= get_thread_lwp (current_inferior
);
4370 return lwp
->stopped_data_address
;
4373 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4374 #if defined(__mcoldfire__)
4375 /* These should really be defined in the kernel's ptrace.h header. */
4376 #define PT_TEXT_ADDR 49*4
4377 #define PT_DATA_ADDR 50*4
4378 #define PT_TEXT_END_ADDR 51*4
4381 /* Under uClinux, programs are loaded at non-zero offsets, which we need
4382 to tell gdb about. */
4385 linux_read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
4387 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
4388 unsigned long text
, text_end
, data
;
4389 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
4393 text
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_ADDR
, 0);
4394 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_END_ADDR
, 0);
4395 data
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_DATA_ADDR
, 0);
4399 /* Both text and data offsets produced at compile-time (and so
4400 used by gdb) are relative to the beginning of the program,
4401 with the data segment immediately following the text segment.
4402 However, the actual runtime layout in memory may put the data
4403 somewhere else, so when we send gdb a data base-address, we
4404 use the real data base address and subtract the compile-time
4405 data base-address from it (which is just the length of the
4406 text segment). BSS immediately follows data in both
4409 *data_p
= data
- (text_end
- text
);
4419 compare_ints (const void *xa
, const void *xb
)
4421 int a
= *(const int *)xa
;
4422 int b
= *(const int *)xb
;
4428 unique (int *b
, int *e
)
4437 /* Given PID, iterates over all threads in that process.
4439 Information about each thread, in a format suitable for qXfer:osdata:thread
4440 is printed to BUFFER, if it's not NULL. BUFFER is assumed to be already
4441 initialized, and the caller is responsible for finishing and appending '\0'
4444 The list of cores that threads are running on is assigned to *CORES, if it
4445 is not NULL. If no cores are found, *CORES will be set to NULL. Caller
4446 should free *CORES. */
4449 list_threads (int pid
, struct buffer
*buffer
, char **cores
)
4453 int *core_numbers
= xmalloc (sizeof (int) * allocated
);
4457 struct stat statbuf
;
4459 sprintf (pathname
, "/proc/%d/task", pid
);
4460 if (stat (pathname
, &statbuf
) == 0 && S_ISDIR (statbuf
.st_mode
))
4462 dir
= opendir (pathname
);
4465 free (core_numbers
);
4469 while ((dp
= readdir (dir
)) != NULL
)
4471 unsigned long lwp
= strtoul (dp
->d_name
, NULL
, 10);
4475 unsigned core
= linux_core_of_thread (ptid_build (pid
, lwp
, 0));
4479 char s
[sizeof ("4294967295")];
4480 sprintf (s
, "%u", core
);
4482 if (count
== allocated
)
4485 core_numbers
= realloc (core_numbers
,
4486 sizeof (int) * allocated
);
4488 core_numbers
[count
++] = core
;
4490 buffer_xml_printf (buffer
,
4492 "<column name=\"pid\">%d</column>"
4493 "<column name=\"tid\">%s</column>"
4494 "<column name=\"core\">%s</column>"
4495 "</item>", pid
, dp
->d_name
, s
);
4500 buffer_xml_printf (buffer
,
4502 "<column name=\"pid\">%d</column>"
4503 "<column name=\"tid\">%s</column>"
4504 "</item>", pid
, dp
->d_name
);
4515 struct buffer buffer2
;
4518 qsort (core_numbers
, count
, sizeof (int), compare_ints
);
4520 /* Remove duplicates. */
4522 e
= unique (b
, core_numbers
+ count
);
4524 buffer_init (&buffer2
);
4526 for (b
= core_numbers
; b
!= e
; ++b
)
4528 char number
[sizeof ("4294967295")];
4529 sprintf (number
, "%u", *b
);
4530 buffer_xml_printf (&buffer2
, "%s%s",
4531 (b
== core_numbers
) ? "" : ",", number
);
4533 buffer_grow_str0 (&buffer2
, "");
4535 *cores
= buffer_finish (&buffer2
);
4538 free (core_numbers
);
4542 show_process (int pid
, const char *username
, struct buffer
*buffer
)
4546 char cmd
[MAXPATHLEN
+ 1];
4548 sprintf (pathname
, "/proc/%d/cmdline", pid
);
4550 if ((f
= fopen (pathname
, "r")) != NULL
)
4552 size_t len
= fread (cmd
, 1, sizeof (cmd
) - 1, f
);
4557 for (i
= 0; i
< len
; i
++)
4562 buffer_xml_printf (buffer
,
4564 "<column name=\"pid\">%d</column>"
4565 "<column name=\"user\">%s</column>"
4566 "<column name=\"command\">%s</column>",
4571 /* This only collects core numbers, and does not print threads. */
4572 list_threads (pid
, NULL
, &cores
);
4576 buffer_xml_printf (buffer
,
4577 "<column name=\"cores\">%s</column>", cores
);
4581 buffer_xml_printf (buffer
, "</item>");
4588 linux_qxfer_osdata (const char *annex
,
4589 unsigned char *readbuf
, unsigned const char *writebuf
,
4590 CORE_ADDR offset
, int len
)
4592 /* We make the process list snapshot when the object starts to be
4594 static const char *buf
;
4595 static long len_avail
= -1;
4596 static struct buffer buffer
;
4602 if (strcmp (annex
, "processes") == 0)
4604 else if (strcmp (annex
, "threads") == 0)
4609 if (!readbuf
|| writebuf
)
4614 if (len_avail
!= -1 && len_avail
!= 0)
4615 buffer_free (&buffer
);
4618 buffer_init (&buffer
);
4620 buffer_grow_str (&buffer
, "<osdata type=\"processes\">");
4622 buffer_grow_str (&buffer
, "<osdata type=\"threads\">");
4624 dirp
= opendir ("/proc");
4628 while ((dp
= readdir (dirp
)) != NULL
)
4630 struct stat statbuf
;
4631 char procentry
[sizeof ("/proc/4294967295")];
4633 if (!isdigit (dp
->d_name
[0])
4634 || strlen (dp
->d_name
) > sizeof ("4294967295") - 1)
4637 sprintf (procentry
, "/proc/%s", dp
->d_name
);
4638 if (stat (procentry
, &statbuf
) == 0
4639 && S_ISDIR (statbuf
.st_mode
))
4641 int pid
= (int) strtoul (dp
->d_name
, NULL
, 10);
4645 struct passwd
*entry
= getpwuid (statbuf
.st_uid
);
4646 show_process (pid
, entry
? entry
->pw_name
: "?", &buffer
);
4650 list_threads (pid
, &buffer
, NULL
);
4657 buffer_grow_str0 (&buffer
, "</osdata>\n");
4658 buf
= buffer_finish (&buffer
);
4659 len_avail
= strlen (buf
);
4662 if (offset
>= len_avail
)
4664 /* Done. Get rid of the data. */
4665 buffer_free (&buffer
);
4671 if (len
> len_avail
- offset
)
4672 len
= len_avail
- offset
;
4673 memcpy (readbuf
, buf
+ offset
, len
);
4678 /* Convert a native/host siginfo object, into/from the siginfo in the
4679 layout of the inferiors' architecture. */
4682 siginfo_fixup (struct siginfo
*siginfo
, void *inf_siginfo
, int direction
)
4686 if (the_low_target
.siginfo_fixup
!= NULL
)
4687 done
= the_low_target
.siginfo_fixup (siginfo
, inf_siginfo
, direction
);
4689 /* If there was no callback, or the callback didn't do anything,
4690 then just do a straight memcpy. */
4694 memcpy (siginfo
, inf_siginfo
, sizeof (struct siginfo
));
4696 memcpy (inf_siginfo
, siginfo
, sizeof (struct siginfo
));
4701 linux_xfer_siginfo (const char *annex
, unsigned char *readbuf
,
4702 unsigned const char *writebuf
, CORE_ADDR offset
, int len
)
4705 struct siginfo siginfo
;
4706 char inf_siginfo
[sizeof (struct siginfo
)];
4708 if (current_inferior
== NULL
)
4711 pid
= lwpid_of (get_thread_lwp (current_inferior
));
4714 fprintf (stderr
, "%s siginfo for lwp %d.\n",
4715 readbuf
!= NULL
? "Reading" : "Writing",
4718 if (offset
> sizeof (siginfo
))
4721 if (ptrace (PTRACE_GETSIGINFO
, pid
, 0, &siginfo
) != 0)
4724 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
4725 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
4726 inferior with a 64-bit GDBSERVER should look the same as debugging it
4727 with a 32-bit GDBSERVER, we need to convert it. */
4728 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
4730 if (offset
+ len
> sizeof (siginfo
))
4731 len
= sizeof (siginfo
) - offset
;
4733 if (readbuf
!= NULL
)
4734 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
4737 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
4739 /* Convert back to ptrace layout before flushing it out. */
4740 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
4742 if (ptrace (PTRACE_SETSIGINFO
, pid
, 0, &siginfo
) != 0)
4749 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4750 so we notice when children change state; as the handler for the
4751 sigsuspend in my_waitpid. */
4754 sigchld_handler (int signo
)
4756 int old_errno
= errno
;
4762 /* fprintf is not async-signal-safe, so call write
4764 if (write (2, "sigchld_handler\n",
4765 sizeof ("sigchld_handler\n") - 1) < 0)
4766 break; /* just ignore */
4770 if (target_is_async_p ())
4771 async_file_mark (); /* trigger a linux_wait */
4777 linux_supports_non_stop (void)
4783 linux_async (int enable
)
4785 int previous
= (linux_event_pipe
[0] != -1);
4788 fprintf (stderr
, "linux_async (%d), previous=%d\n",
4791 if (previous
!= enable
)
4794 sigemptyset (&mask
);
4795 sigaddset (&mask
, SIGCHLD
);
4797 sigprocmask (SIG_BLOCK
, &mask
, NULL
);
4801 if (pipe (linux_event_pipe
) == -1)
4802 fatal ("creating event pipe failed.");
4804 fcntl (linux_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4805 fcntl (linux_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4807 /* Register the event loop handler. */
4808 add_file_handler (linux_event_pipe
[0],
4809 handle_target_event
, NULL
);
4811 /* Always trigger a linux_wait. */
4816 delete_file_handler (linux_event_pipe
[0]);
4818 close (linux_event_pipe
[0]);
4819 close (linux_event_pipe
[1]);
4820 linux_event_pipe
[0] = -1;
4821 linux_event_pipe
[1] = -1;
4824 sigprocmask (SIG_UNBLOCK
, &mask
, NULL
);
4831 linux_start_non_stop (int nonstop
)
4833 /* Register or unregister from event-loop accordingly. */
4834 linux_async (nonstop
);
4839 linux_supports_multi_process (void)
4845 /* Enumerate spufs IDs for process PID. */
4847 spu_enumerate_spu_ids (long pid
, unsigned char *buf
, CORE_ADDR offset
, int len
)
4853 struct dirent
*entry
;
4855 sprintf (path
, "/proc/%ld/fd", pid
);
4856 dir
= opendir (path
);
4861 while ((entry
= readdir (dir
)) != NULL
)
4867 fd
= atoi (entry
->d_name
);
4871 sprintf (path
, "/proc/%ld/fd/%d", pid
, fd
);
4872 if (stat (path
, &st
) != 0)
4874 if (!S_ISDIR (st
.st_mode
))
4877 if (statfs (path
, &stfs
) != 0)
4879 if (stfs
.f_type
!= SPUFS_MAGIC
)
4882 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4884 *(unsigned int *)(buf
+ pos
- offset
) = fd
;
4894 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
4895 object type, using the /proc file system. */
4897 linux_qxfer_spu (const char *annex
, unsigned char *readbuf
,
4898 unsigned const char *writebuf
,
4899 CORE_ADDR offset
, int len
)
4901 long pid
= lwpid_of (get_thread_lwp (current_inferior
));
4906 if (!writebuf
&& !readbuf
)
4914 return spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4917 sprintf (buf
, "/proc/%ld/fd/%s", pid
, annex
);
4918 fd
= open (buf
, writebuf
? O_WRONLY
: O_RDONLY
);
4923 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4930 ret
= write (fd
, writebuf
, (size_t) len
);
4932 ret
= read (fd
, readbuf
, (size_t) len
);
4939 linux_core_of_thread (ptid_t ptid
)
4941 char filename
[sizeof ("/proc//task//stat")
4942 + 2 * 20 /* decimal digits for 2 numbers, max 2^64 bit each */
4945 char *content
= NULL
;
4948 int content_read
= 0;
4952 sprintf (filename
, "/proc/%d/task/%ld/stat",
4953 ptid_get_pid (ptid
), ptid_get_lwp (ptid
));
4954 f
= fopen (filename
, "r");
4961 content
= realloc (content
, content_read
+ 1024);
4962 n
= fread (content
+ content_read
, 1, 1024, f
);
4966 content
[content_read
] = '\0';
4971 p
= strchr (content
, '(');
4975 p
= strchr (p
, ')');
4979 /* If the first field after program name has index 0, then core number is
4980 the field with index 36. There's no constant for that anywhere. */
4982 p
= strtok_r (p
, " ", &ts
);
4983 for (i
= 0; p
!= NULL
&& i
!= 36; ++i
)
4984 p
= strtok_r (NULL
, " ", &ts
);
4986 if (p
== NULL
|| sscanf (p
, "%d", &core
) == 0)
4996 linux_process_qsupported (const char *query
)
4998 if (the_low_target
.process_qsupported
!= NULL
)
4999 the_low_target
.process_qsupported (query
);
5003 linux_supports_tracepoints (void)
5005 if (*the_low_target
.supports_tracepoints
== NULL
)
5008 return (*the_low_target
.supports_tracepoints
) ();
5012 linux_read_pc (struct regcache
*regcache
)
5014 if (the_low_target
.get_pc
== NULL
)
5017 return (*the_low_target
.get_pc
) (regcache
);
5021 linux_write_pc (struct regcache
*regcache
, CORE_ADDR pc
)
5023 gdb_assert (the_low_target
.set_pc
!= NULL
);
5025 (*the_low_target
.set_pc
) (regcache
, pc
);
5029 linux_thread_stopped (struct thread_info
*thread
)
5031 return get_thread_lwp (thread
)->stopped
;
5034 /* This exposes stop-all-threads functionality to other modules. */
5037 linux_pause_all (int freeze
)
5039 stop_all_lwps (freeze
, NULL
);
5042 /* This exposes unstop-all-threads functionality to other gdbserver
5046 linux_unpause_all (int unfreeze
)
5048 unstop_all_lwps (unfreeze
, NULL
);
5052 linux_prepare_to_access_memory (void)
5054 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
5057 linux_pause_all (1);
5062 linux_done_accessing_memory (void)
5064 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
5067 linux_unpause_all (1);
5071 linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint
, CORE_ADDR tpaddr
,
5072 CORE_ADDR collector
,
5075 CORE_ADDR
*jump_entry
,
5076 unsigned char *jjump_pad_insn
,
5077 ULONGEST
*jjump_pad_insn_size
,
5078 CORE_ADDR
*adjusted_insn_addr
,
5079 CORE_ADDR
*adjusted_insn_addr_end
)
5081 return (*the_low_target
.install_fast_tracepoint_jump_pad
)
5082 (tpoint
, tpaddr
, collector
, lockaddr
, orig_size
,
5083 jump_entry
, jjump_pad_insn
, jjump_pad_insn_size
,
5084 adjusted_insn_addr
, adjusted_insn_addr_end
);
5087 static struct emit_ops
*
5088 linux_emit_ops (void)
5090 if (the_low_target
.emit_ops
!= NULL
)
5091 return (*the_low_target
.emit_ops
) ();
5096 static struct target_ops linux_target_ops
= {
5097 linux_create_inferior
,
5106 linux_fetch_registers
,
5107 linux_store_registers
,
5108 linux_prepare_to_access_memory
,
5109 linux_done_accessing_memory
,
5112 linux_look_up_symbols
,
5113 linux_request_interrupt
,
5117 linux_stopped_by_watchpoint
,
5118 linux_stopped_data_address
,
5119 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
5124 #ifdef USE_THREAD_DB
5125 thread_db_get_tls_address
,
5130 hostio_last_error_from_errno
,
5133 linux_supports_non_stop
,
5135 linux_start_non_stop
,
5136 linux_supports_multi_process
,
5137 #ifdef USE_THREAD_DB
5138 thread_db_handle_monitor_command
,
5142 linux_core_of_thread
,
5143 linux_process_qsupported
,
5144 linux_supports_tracepoints
,
5147 linux_thread_stopped
,
5151 linux_cancel_breakpoints
,
5152 linux_stabilize_threads
,
5153 linux_install_fast_tracepoint_jump_pad
,
5158 linux_init_signals ()
5160 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
5161 to find what the cancel signal actually is. */
5162 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
5163 signal (__SIGRTMIN
+1, SIG_IGN
);
5168 initialize_low (void)
5170 struct sigaction sigchld_action
;
5171 memset (&sigchld_action
, 0, sizeof (sigchld_action
));
5172 set_target_ops (&linux_target_ops
);
5173 set_breakpoint_data (the_low_target
.breakpoint
,
5174 the_low_target
.breakpoint_len
);
5175 linux_init_signals ();
5176 linux_test_for_tracefork ();
5177 #ifdef HAVE_LINUX_REGSETS
5178 for (num_regsets
= 0; target_regsets
[num_regsets
].size
>= 0; num_regsets
++)
5180 disabled_regsets
= xmalloc (num_regsets
);
5183 sigchld_action
.sa_handler
= sigchld_handler
;
5184 sigemptyset (&sigchld_action
.sa_mask
);
5185 sigchld_action
.sa_flags
= SA_RESTART
;
5186 sigaction (SIGCHLD
, &sigchld_action
, NULL
);