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, 2011 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
;
781 process
= find_process_pid (pid
);
785 /* If we're killing a running inferior, make sure it is stopped
786 first, as PTRACE_KILL will not work otherwise. */
787 stop_all_lwps (0, NULL
);
789 find_inferior (&all_threads
, linux_kill_one_lwp
, &pid
);
791 /* See the comment in linux_kill_one_lwp. We did not kill the first
792 thread in the list, so do so now. */
793 lwp
= find_lwp_pid (pid_to_ptid (pid
));
796 fprintf (stderr
, "lk_1: killing lwp %ld, for pid: %d\n",
797 lwpid_of (lwp
), pid
);
801 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
803 /* Make sure it died. The loop is most likely unnecessary. */
804 lwpid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
805 } while (lwpid
> 0 && WIFSTOPPED (wstat
));
807 the_target
->mourn (process
);
809 /* Since we presently can only stop all lwps of all processes, we
810 need to unstop lwps of other processes. */
811 unstop_all_lwps (0, NULL
);
816 linux_detach_one_lwp (struct inferior_list_entry
*entry
, void *args
)
818 struct thread_info
*thread
= (struct thread_info
*) entry
;
819 struct lwp_info
*lwp
= get_thread_lwp (thread
);
820 int pid
= * (int *) args
;
822 if (ptid_get_pid (entry
->id
) != pid
)
825 /* If this process is stopped but is expecting a SIGSTOP, then make
826 sure we take care of that now. This isn't absolutely guaranteed
827 to collect the SIGSTOP, but is fairly likely to. */
828 if (lwp
->stop_expected
)
831 /* Clear stop_expected, so that the SIGSTOP will be reported. */
832 lwp
->stop_expected
= 0;
833 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
834 linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
837 /* Flush any pending changes to the process's registers. */
838 regcache_invalidate_one ((struct inferior_list_entry
*)
839 get_lwp_thread (lwp
));
841 /* Finally, let it resume. */
842 ptrace (PTRACE_DETACH
, lwpid_of (lwp
), 0, 0);
849 linux_detach (int pid
)
851 struct process_info
*process
;
853 process
= find_process_pid (pid
);
857 /* Stop all threads before detaching. First, ptrace requires that
858 the thread is stopped to sucessfully detach. Second, thread_db
859 may need to uninstall thread event breakpoints from memory, which
860 only works with a stopped process anyway. */
861 stop_all_lwps (0, NULL
);
864 thread_db_detach (process
);
867 /* Stabilize threads (move out of jump pads). */
868 stabilize_threads ();
870 find_inferior (&all_threads
, linux_detach_one_lwp
, &pid
);
872 the_target
->mourn (process
);
874 /* Since we presently can only stop all lwps of all processes, we
875 need to unstop lwps of other processes. */
876 unstop_all_lwps (0, NULL
);
880 /* Remove all LWPs that belong to process PROC from the lwp list. */
883 delete_lwp_callback (struct inferior_list_entry
*entry
, void *proc
)
885 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
886 struct process_info
*process
= proc
;
888 if (pid_of (lwp
) == pid_of (process
))
895 linux_mourn (struct process_info
*process
)
897 struct process_info_private
*priv
;
900 thread_db_mourn (process
);
903 find_inferior (&all_lwps
, delete_lwp_callback
, process
);
905 /* Freeing all private data. */
906 priv
= process
->private;
907 free (priv
->arch_private
);
909 process
->private = NULL
;
911 remove_process (process
);
918 struct process_info
*process
;
920 process
= find_process_pid (pid
);
925 ret
= my_waitpid (pid
, &status
, 0);
926 if (WIFEXITED (status
) || WIFSIGNALED (status
))
928 } while (ret
!= -1 || errno
!= ECHILD
);
931 /* Return nonzero if the given thread is still alive. */
933 linux_thread_alive (ptid_t ptid
)
935 struct lwp_info
*lwp
= find_lwp_pid (ptid
);
937 /* We assume we always know if a thread exits. If a whole process
938 exited but we still haven't been able to report it to GDB, we'll
939 hold on to the last lwp of the dead process. */
946 /* Return 1 if this lwp has an interesting status pending. */
948 status_pending_p_callback (struct inferior_list_entry
*entry
, void *arg
)
950 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
951 ptid_t ptid
= * (ptid_t
*) arg
;
952 struct thread_info
*thread
;
954 /* Check if we're only interested in events from a specific process
956 if (!ptid_equal (minus_one_ptid
, ptid
)
957 && ptid_get_pid (ptid
) != ptid_get_pid (lwp
->head
.id
))
960 thread
= get_lwp_thread (lwp
);
962 /* If we got a `vCont;t', but we haven't reported a stop yet, do
963 report any status pending the LWP may have. */
964 if (thread
->last_resume_kind
== resume_stop
965 && thread
->last_status
.kind
!= TARGET_WAITKIND_IGNORE
)
968 return lwp
->status_pending_p
;
972 same_lwp (struct inferior_list_entry
*entry
, void *data
)
974 ptid_t ptid
= *(ptid_t
*) data
;
977 if (ptid_get_lwp (ptid
) != 0)
978 lwp
= ptid_get_lwp (ptid
);
980 lwp
= ptid_get_pid (ptid
);
982 if (ptid_get_lwp (entry
->id
) == lwp
)
989 find_lwp_pid (ptid_t ptid
)
991 return (struct lwp_info
*) find_inferior (&all_lwps
, same_lwp
, &ptid
);
994 static struct lwp_info
*
995 linux_wait_for_lwp (ptid_t ptid
, int *wstatp
, int options
)
998 int to_wait_for
= -1;
999 struct lwp_info
*child
= NULL
;
1002 fprintf (stderr
, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid
));
1004 if (ptid_equal (ptid
, minus_one_ptid
))
1005 to_wait_for
= -1; /* any child */
1007 to_wait_for
= ptid_get_lwp (ptid
); /* this lwp only */
1013 ret
= my_waitpid (to_wait_for
, wstatp
, options
);
1014 if (ret
== 0 || (ret
== -1 && errno
== ECHILD
&& (options
& WNOHANG
)))
1017 perror_with_name ("waitpid");
1020 && (!WIFSTOPPED (*wstatp
)
1021 || (WSTOPSIG (*wstatp
) != 32
1022 && WSTOPSIG (*wstatp
) != 33)))
1023 fprintf (stderr
, "Got an event from %d (%x)\n", ret
, *wstatp
);
1025 child
= find_lwp_pid (pid_to_ptid (ret
));
1027 /* If we didn't find a process, one of two things presumably happened:
1028 - A process we started and then detached from has exited. Ignore it.
1029 - A process we are controlling has forked and the new child's stop
1030 was reported to us by the kernel. Save its PID. */
1031 if (child
== NULL
&& WIFSTOPPED (*wstatp
))
1033 add_pid_to_list (&stopped_pids
, ret
);
1036 else if (child
== NULL
)
1041 child
->last_status
= *wstatp
;
1043 /* Architecture-specific setup after inferior is running.
1044 This needs to happen after we have attached to the inferior
1045 and it is stopped for the first time, but before we access
1046 any inferior registers. */
1049 the_low_target
.arch_setup ();
1050 #ifdef HAVE_LINUX_REGSETS
1051 memset (disabled_regsets
, 0, num_regsets
);
1056 /* Fetch the possibly triggered data watchpoint info and store it in
1059 On some archs, like x86, that use debug registers to set
1060 watchpoints, it's possible that the way to know which watched
1061 address trapped, is to check the register that is used to select
1062 which address to watch. Problem is, between setting the
1063 watchpoint and reading back which data address trapped, the user
1064 may change the set of watchpoints, and, as a consequence, GDB
1065 changes the debug registers in the inferior. To avoid reading
1066 back a stale stopped-data-address when that happens, we cache in
1067 LP the fact that a watchpoint trapped, and the corresponding data
1068 address, as soon as we see CHILD stop with a SIGTRAP. If GDB
1069 changes the debug registers meanwhile, we have the cached data we
1072 if (WIFSTOPPED (*wstatp
) && WSTOPSIG (*wstatp
) == SIGTRAP
)
1074 if (the_low_target
.stopped_by_watchpoint
== NULL
)
1076 child
->stopped_by_watchpoint
= 0;
1080 struct thread_info
*saved_inferior
;
1082 saved_inferior
= current_inferior
;
1083 current_inferior
= get_lwp_thread (child
);
1085 child
->stopped_by_watchpoint
1086 = the_low_target
.stopped_by_watchpoint ();
1088 if (child
->stopped_by_watchpoint
)
1090 if (the_low_target
.stopped_data_address
!= NULL
)
1091 child
->stopped_data_address
1092 = the_low_target
.stopped_data_address ();
1094 child
->stopped_data_address
= 0;
1097 current_inferior
= saved_inferior
;
1101 /* Store the STOP_PC, with adjustment applied. This depends on the
1102 architecture being defined already (so that CHILD has a valid
1103 regcache), and on LAST_STATUS being set (to check for SIGTRAP or
1105 if (WIFSTOPPED (*wstatp
))
1106 child
->stop_pc
= get_stop_pc (child
);
1109 && WIFSTOPPED (*wstatp
)
1110 && the_low_target
.get_pc
!= NULL
)
1112 struct thread_info
*saved_inferior
= current_inferior
;
1113 struct regcache
*regcache
;
1116 current_inferior
= get_lwp_thread (child
);
1117 regcache
= get_thread_regcache (current_inferior
, 1);
1118 pc
= (*the_low_target
.get_pc
) (regcache
);
1119 fprintf (stderr
, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc
);
1120 current_inferior
= saved_inferior
;
1126 /* This function should only be called if the LWP got a SIGTRAP.
1128 Handle any tracepoint steps or hits. Return true if a tracepoint
1129 event was handled, 0 otherwise. */
1132 handle_tracepoints (struct lwp_info
*lwp
)
1134 struct thread_info
*tinfo
= get_lwp_thread (lwp
);
1135 int tpoint_related_event
= 0;
1137 /* If this tracepoint hit causes a tracing stop, we'll immediately
1138 uninsert tracepoints. To do this, we temporarily pause all
1139 threads, unpatch away, and then unpause threads. We need to make
1140 sure the unpausing doesn't resume LWP too. */
1143 /* And we need to be sure that any all-threads-stopping doesn't try
1144 to move threads out of the jump pads, as it could deadlock the
1145 inferior (LWP could be in the jump pad, maybe even holding the
1148 /* Do any necessary step collect actions. */
1149 tpoint_related_event
|= tracepoint_finished_step (tinfo
, lwp
->stop_pc
);
1151 tpoint_related_event
|= handle_tracepoint_bkpts (tinfo
, lwp
->stop_pc
);
1153 /* See if we just hit a tracepoint and do its main collect
1155 tpoint_related_event
|= tracepoint_was_hit (tinfo
, lwp
->stop_pc
);
1159 gdb_assert (lwp
->suspended
== 0);
1160 gdb_assert (!stabilizing_threads
|| lwp
->collecting_fast_tracepoint
);
1162 if (tpoint_related_event
)
1165 fprintf (stderr
, "got a tracepoint event\n");
1172 /* Convenience wrapper. Returns true if LWP is presently collecting a
1176 linux_fast_tracepoint_collecting (struct lwp_info
*lwp
,
1177 struct fast_tpoint_collect_status
*status
)
1179 CORE_ADDR thread_area
;
1181 if (the_low_target
.get_thread_area
== NULL
)
1184 /* Get the thread area address. This is used to recognize which
1185 thread is which when tracing with the in-process agent library.
1186 We don't read anything from the address, and treat it as opaque;
1187 it's the address itself that we assume is unique per-thread. */
1188 if ((*the_low_target
.get_thread_area
) (lwpid_of (lwp
), &thread_area
) == -1)
1191 return fast_tracepoint_collecting (thread_area
, lwp
->stop_pc
, status
);
1194 /* The reason we resume in the caller, is because we want to be able
1195 to pass lwp->status_pending as WSTAT, and we need to clear
1196 status_pending_p before resuming, otherwise, linux_resume_one_lwp
1197 refuses to resume. */
1200 maybe_move_out_of_jump_pad (struct lwp_info
*lwp
, int *wstat
)
1202 struct thread_info
*saved_inferior
;
1204 saved_inferior
= current_inferior
;
1205 current_inferior
= get_lwp_thread (lwp
);
1208 || (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) != SIGTRAP
))
1209 && supports_fast_tracepoints ()
1210 && in_process_agent_loaded ())
1212 struct fast_tpoint_collect_status status
;
1217 Checking whether LWP %ld needs to move out of the jump pad.\n",
1220 r
= linux_fast_tracepoint_collecting (lwp
, &status
);
1223 || (WSTOPSIG (*wstat
) != SIGILL
1224 && WSTOPSIG (*wstat
) != SIGFPE
1225 && WSTOPSIG (*wstat
) != SIGSEGV
1226 && WSTOPSIG (*wstat
) != SIGBUS
))
1228 lwp
->collecting_fast_tracepoint
= r
;
1232 if (r
== 1 && lwp
->exit_jump_pad_bkpt
== NULL
)
1234 /* Haven't executed the original instruction yet.
1235 Set breakpoint there, and wait till it's hit,
1236 then single-step until exiting the jump pad. */
1237 lwp
->exit_jump_pad_bkpt
1238 = set_breakpoint_at (status
.adjusted_insn_addr
, NULL
);
1243 Checking whether LWP %ld needs to move out of the jump pad...it does\n",
1245 current_inferior
= saved_inferior
;
1252 /* If we get a synchronous signal while collecting, *and*
1253 while executing the (relocated) original instruction,
1254 reset the PC to point at the tpoint address, before
1255 reporting to GDB. Otherwise, it's an IPA lib bug: just
1256 report the signal to GDB, and pray for the best. */
1258 lwp
->collecting_fast_tracepoint
= 0;
1261 && (status
.adjusted_insn_addr
<= lwp
->stop_pc
1262 && lwp
->stop_pc
< status
.adjusted_insn_addr_end
))
1265 struct regcache
*regcache
;
1267 /* The si_addr on a few signals references the address
1268 of the faulting instruction. Adjust that as
1270 if ((WSTOPSIG (*wstat
) == SIGILL
1271 || WSTOPSIG (*wstat
) == SIGFPE
1272 || WSTOPSIG (*wstat
) == SIGBUS
1273 || WSTOPSIG (*wstat
) == SIGSEGV
)
1274 && ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &info
) == 0
1275 /* Final check just to make sure we don't clobber
1276 the siginfo of non-kernel-sent signals. */
1277 && (uintptr_t) info
.si_addr
== lwp
->stop_pc
)
1279 info
.si_addr
= (void *) (uintptr_t) status
.tpoint_addr
;
1280 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &info
);
1283 regcache
= get_thread_regcache (get_lwp_thread (lwp
), 1);
1284 (*the_low_target
.set_pc
) (regcache
, status
.tpoint_addr
);
1285 lwp
->stop_pc
= status
.tpoint_addr
;
1287 /* Cancel any fast tracepoint lock this thread was
1289 force_unlock_trace_buffer ();
1292 if (lwp
->exit_jump_pad_bkpt
!= NULL
)
1296 "Cancelling fast exit-jump-pad: removing bkpt. "
1297 "stopping all threads momentarily.\n");
1299 stop_all_lwps (1, lwp
);
1300 cancel_breakpoints ();
1302 delete_breakpoint (lwp
->exit_jump_pad_bkpt
);
1303 lwp
->exit_jump_pad_bkpt
= NULL
;
1305 unstop_all_lwps (1, lwp
);
1307 gdb_assert (lwp
->suspended
>= 0);
1314 Checking whether LWP %ld needs to move out of the jump pad...no\n",
1317 current_inferior
= saved_inferior
;
1321 /* Enqueue one signal in the "signals to report later when out of the
1325 enqueue_one_deferred_signal (struct lwp_info
*lwp
, int *wstat
)
1327 struct pending_signals
*p_sig
;
1331 Deferring signal %d for LWP %ld.\n", WSTOPSIG (*wstat
), lwpid_of (lwp
));
1335 struct pending_signals
*sig
;
1337 for (sig
= lwp
->pending_signals_to_report
;
1341 " Already queued %d\n",
1344 fprintf (stderr
, " (no more currently queued signals)\n");
1347 /* Don't enqueue non-RT signals if they are already in the deferred
1348 queue. (SIGSTOP being the easiest signal to see ending up here
1350 if (WSTOPSIG (*wstat
) < __SIGRTMIN
)
1352 struct pending_signals
*sig
;
1354 for (sig
= lwp
->pending_signals_to_report
;
1358 if (sig
->signal
== WSTOPSIG (*wstat
))
1362 "Not requeuing already queued non-RT signal %d"
1371 p_sig
= xmalloc (sizeof (*p_sig
));
1372 p_sig
->prev
= lwp
->pending_signals_to_report
;
1373 p_sig
->signal
= WSTOPSIG (*wstat
);
1374 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
1375 ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &p_sig
->info
);
1377 lwp
->pending_signals_to_report
= p_sig
;
1380 /* Dequeue one signal from the "signals to report later when out of
1381 the jump pad" list. */
1384 dequeue_one_deferred_signal (struct lwp_info
*lwp
, int *wstat
)
1386 if (lwp
->pending_signals_to_report
!= NULL
)
1388 struct pending_signals
**p_sig
;
1390 p_sig
= &lwp
->pending_signals_to_report
;
1391 while ((*p_sig
)->prev
!= NULL
)
1392 p_sig
= &(*p_sig
)->prev
;
1394 *wstat
= W_STOPCODE ((*p_sig
)->signal
);
1395 if ((*p_sig
)->info
.si_signo
!= 0)
1396 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &(*p_sig
)->info
);
1401 fprintf (stderr
, "Reporting deferred signal %d for LWP %ld.\n",
1402 WSTOPSIG (*wstat
), lwpid_of (lwp
));
1406 struct pending_signals
*sig
;
1408 for (sig
= lwp
->pending_signals_to_report
;
1412 " Still queued %d\n",
1415 fprintf (stderr
, " (no more queued signals)\n");
1424 /* Arrange for a breakpoint to be hit again later. We don't keep the
1425 SIGTRAP status and don't forward the SIGTRAP signal to the LWP. We
1426 will handle the current event, eventually we will resume this LWP,
1427 and this breakpoint will trap again. */
1430 cancel_breakpoint (struct lwp_info
*lwp
)
1432 struct thread_info
*saved_inferior
;
1434 /* There's nothing to do if we don't support breakpoints. */
1435 if (!supports_breakpoints ())
1438 /* breakpoint_at reads from current inferior. */
1439 saved_inferior
= current_inferior
;
1440 current_inferior
= get_lwp_thread (lwp
);
1442 if ((*the_low_target
.breakpoint_at
) (lwp
->stop_pc
))
1446 "CB: Push back breakpoint for %s\n",
1447 target_pid_to_str (ptid_of (lwp
)));
1449 /* Back up the PC if necessary. */
1450 if (the_low_target
.decr_pc_after_break
)
1452 struct regcache
*regcache
1453 = get_thread_regcache (current_inferior
, 1);
1454 (*the_low_target
.set_pc
) (regcache
, lwp
->stop_pc
);
1457 current_inferior
= saved_inferior
;
1464 "CB: No breakpoint found at %s for [%s]\n",
1465 paddress (lwp
->stop_pc
),
1466 target_pid_to_str (ptid_of (lwp
)));
1469 current_inferior
= saved_inferior
;
1473 /* When the event-loop is doing a step-over, this points at the thread
1475 ptid_t step_over_bkpt
;
1477 /* Wait for an event from child PID. If PID is -1, wait for any
1478 child. Store the stop status through the status pointer WSTAT.
1479 OPTIONS is passed to the waitpid call. Return 0 if no child stop
1480 event was found and OPTIONS contains WNOHANG. Return the PID of
1481 the stopped child otherwise. */
1484 linux_wait_for_event_1 (ptid_t ptid
, int *wstat
, int options
)
1486 struct lwp_info
*event_child
, *requested_child
;
1489 requested_child
= NULL
;
1491 /* Check for a lwp with a pending status. */
1493 if (ptid_equal (ptid
, minus_one_ptid
)
1494 || ptid_equal (pid_to_ptid (ptid_get_pid (ptid
)), ptid
))
1496 event_child
= (struct lwp_info
*)
1497 find_inferior (&all_lwps
, status_pending_p_callback
, &ptid
);
1498 if (debug_threads
&& event_child
)
1499 fprintf (stderr
, "Got a pending child %ld\n", lwpid_of (event_child
));
1503 requested_child
= find_lwp_pid (ptid
);
1505 if (!stopping_threads
1506 && requested_child
->status_pending_p
1507 && requested_child
->collecting_fast_tracepoint
)
1509 enqueue_one_deferred_signal (requested_child
,
1510 &requested_child
->status_pending
);
1511 requested_child
->status_pending_p
= 0;
1512 requested_child
->status_pending
= 0;
1513 linux_resume_one_lwp (requested_child
, 0, 0, NULL
);
1516 if (requested_child
->suspended
1517 && requested_child
->status_pending_p
)
1518 fatal ("requesting an event out of a suspended child?");
1520 if (requested_child
->status_pending_p
)
1521 event_child
= requested_child
;
1524 if (event_child
!= NULL
)
1527 fprintf (stderr
, "Got an event from pending child %ld (%04x)\n",
1528 lwpid_of (event_child
), event_child
->status_pending
);
1529 *wstat
= event_child
->status_pending
;
1530 event_child
->status_pending_p
= 0;
1531 event_child
->status_pending
= 0;
1532 current_inferior
= get_lwp_thread (event_child
);
1533 return lwpid_of (event_child
);
1536 /* We only enter this loop if no process has a pending wait status. Thus
1537 any action taken in response to a wait status inside this loop is
1538 responding as soon as we detect the status, not after any pending
1542 event_child
= linux_wait_for_lwp (ptid
, wstat
, options
);
1544 if ((options
& WNOHANG
) && event_child
== NULL
)
1547 fprintf (stderr
, "WNOHANG set, no event found\n");
1551 if (event_child
== NULL
)
1552 error ("event from unknown child");
1554 current_inferior
= get_lwp_thread (event_child
);
1556 /* Check for thread exit. */
1557 if (! WIFSTOPPED (*wstat
))
1560 fprintf (stderr
, "LWP %ld exiting\n", lwpid_of (event_child
));
1562 /* If the last thread is exiting, just return. */
1563 if (last_thread_of_process_p (current_inferior
))
1566 fprintf (stderr
, "LWP %ld is last lwp of process\n",
1567 lwpid_of (event_child
));
1568 return lwpid_of (event_child
);
1573 current_inferior
= (struct thread_info
*) all_threads
.head
;
1575 fprintf (stderr
, "Current inferior is now %ld\n",
1576 lwpid_of (get_thread_lwp (current_inferior
)));
1580 current_inferior
= NULL
;
1582 fprintf (stderr
, "Current inferior is now <NULL>\n");
1585 /* If we were waiting for this particular child to do something...
1586 well, it did something. */
1587 if (requested_child
!= NULL
)
1589 int lwpid
= lwpid_of (event_child
);
1591 /* Cancel the step-over operation --- the thread that
1592 started it is gone. */
1593 if (finish_step_over (event_child
))
1594 unstop_all_lwps (1, event_child
);
1595 delete_lwp (event_child
);
1599 delete_lwp (event_child
);
1601 /* Wait for a more interesting event. */
1605 if (event_child
->must_set_ptrace_flags
)
1607 linux_enable_event_reporting (lwpid_of (event_child
));
1608 event_child
->must_set_ptrace_flags
= 0;
1611 if (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) == SIGTRAP
1612 && *wstat
>> 16 != 0)
1614 handle_extended_wait (event_child
, *wstat
);
1618 if (WIFSTOPPED (*wstat
)
1619 && WSTOPSIG (*wstat
) == SIGSTOP
1620 && event_child
->stop_expected
)
1625 fprintf (stderr
, "Expected stop.\n");
1626 event_child
->stop_expected
= 0;
1628 should_stop
= (current_inferior
->last_resume_kind
== resume_stop
1629 || stopping_threads
);
1633 linux_resume_one_lwp (event_child
,
1634 event_child
->stepping
, 0, NULL
);
1639 return lwpid_of (event_child
);
1647 linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
)
1651 if (ptid_is_pid (ptid
))
1653 /* A request to wait for a specific tgid. This is not possible
1654 with waitpid, so instead, we wait for any child, and leave
1655 children we're not interested in right now with a pending
1656 status to report later. */
1657 wait_ptid
= minus_one_ptid
;
1666 event_pid
= linux_wait_for_event_1 (wait_ptid
, wstat
, options
);
1669 && ptid_is_pid (ptid
) && ptid_get_pid (ptid
) != event_pid
)
1671 struct lwp_info
*event_child
1672 = find_lwp_pid (pid_to_ptid (event_pid
));
1674 if (! WIFSTOPPED (*wstat
))
1675 mark_lwp_dead (event_child
, *wstat
);
1678 event_child
->status_pending_p
= 1;
1679 event_child
->status_pending
= *wstat
;
1688 /* Count the LWP's that have had events. */
1691 count_events_callback (struct inferior_list_entry
*entry
, void *data
)
1693 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1694 struct thread_info
*thread
= get_lwp_thread (lp
);
1697 gdb_assert (count
!= NULL
);
1699 /* Count only resumed LWPs that have a SIGTRAP event pending that
1700 should be reported to GDB. */
1701 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1702 && thread
->last_resume_kind
!= resume_stop
1703 && lp
->status_pending_p
1704 && WIFSTOPPED (lp
->status_pending
)
1705 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1706 && !breakpoint_inserted_here (lp
->stop_pc
))
1712 /* Select the LWP (if any) that is currently being single-stepped. */
1715 select_singlestep_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
1717 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1718 struct thread_info
*thread
= get_lwp_thread (lp
);
1720 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1721 && thread
->last_resume_kind
== resume_step
1722 && lp
->status_pending_p
)
1728 /* Select the Nth LWP that has had a SIGTRAP event that should be
1732 select_event_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
1734 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1735 struct thread_info
*thread
= get_lwp_thread (lp
);
1736 int *selector
= data
;
1738 gdb_assert (selector
!= NULL
);
1740 /* Select only resumed LWPs that have a SIGTRAP event pending. */
1741 if (thread
->last_resume_kind
!= resume_stop
1742 && thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1743 && lp
->status_pending_p
1744 && WIFSTOPPED (lp
->status_pending
)
1745 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1746 && !breakpoint_inserted_here (lp
->stop_pc
))
1747 if ((*selector
)-- == 0)
1754 cancel_breakpoints_callback (struct inferior_list_entry
*entry
, void *data
)
1756 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1757 struct thread_info
*thread
= get_lwp_thread (lp
);
1758 struct lwp_info
*event_lp
= data
;
1760 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
1764 /* If a LWP other than the LWP that we're reporting an event for has
1765 hit a GDB breakpoint (as opposed to some random trap signal),
1766 then just arrange for it to hit it again later. We don't keep
1767 the SIGTRAP status and don't forward the SIGTRAP signal to the
1768 LWP. We will handle the current event, eventually we will resume
1769 all LWPs, and this one will get its breakpoint trap again.
1771 If we do not do this, then we run the risk that the user will
1772 delete or disable the breakpoint, but the LWP will have already
1775 if (thread
->last_resume_kind
!= resume_stop
1776 && thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1777 && lp
->status_pending_p
1778 && WIFSTOPPED (lp
->status_pending
)
1779 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1781 && !lp
->stopped_by_watchpoint
1782 && cancel_breakpoint (lp
))
1783 /* Throw away the SIGTRAP. */
1784 lp
->status_pending_p
= 0;
1790 linux_cancel_breakpoints (void)
1792 find_inferior (&all_lwps
, cancel_breakpoints_callback
, NULL
);
1795 /* Select one LWP out of those that have events pending. */
1798 select_event_lwp (struct lwp_info
**orig_lp
)
1801 int random_selector
;
1802 struct lwp_info
*event_lp
;
1804 /* Give preference to any LWP that is being single-stepped. */
1806 = (struct lwp_info
*) find_inferior (&all_lwps
,
1807 select_singlestep_lwp_callback
, NULL
);
1808 if (event_lp
!= NULL
)
1812 "SEL: Select single-step %s\n",
1813 target_pid_to_str (ptid_of (event_lp
)));
1817 /* No single-stepping LWP. Select one at random, out of those
1818 which have had SIGTRAP events. */
1820 /* First see how many SIGTRAP events we have. */
1821 find_inferior (&all_lwps
, count_events_callback
, &num_events
);
1823 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
1824 random_selector
= (int)
1825 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
1827 if (debug_threads
&& num_events
> 1)
1829 "SEL: Found %d SIGTRAP events, selecting #%d\n",
1830 num_events
, random_selector
);
1832 event_lp
= (struct lwp_info
*) find_inferior (&all_lwps
,
1833 select_event_lwp_callback
,
1837 if (event_lp
!= NULL
)
1839 /* Switch the event LWP. */
1840 *orig_lp
= event_lp
;
1844 /* Decrement the suspend count of an LWP. */
1847 unsuspend_one_lwp (struct inferior_list_entry
*entry
, void *except
)
1849 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1851 /* Ignore EXCEPT. */
1857 gdb_assert (lwp
->suspended
>= 0);
1861 /* Decrement the suspend count of all LWPs, except EXCEPT, if non
1865 unsuspend_all_lwps (struct lwp_info
*except
)
1867 find_inferior (&all_lwps
, unsuspend_one_lwp
, except
);
1870 static void move_out_of_jump_pad_callback (struct inferior_list_entry
*entry
);
1871 static int stuck_in_jump_pad_callback (struct inferior_list_entry
*entry
,
1873 static int lwp_running (struct inferior_list_entry
*entry
, void *data
);
1874 static ptid_t
linux_wait_1 (ptid_t ptid
,
1875 struct target_waitstatus
*ourstatus
,
1876 int target_options
);
1878 /* Stabilize threads (move out of jump pads).
1880 If a thread is midway collecting a fast tracepoint, we need to
1881 finish the collection and move it out of the jump pad before
1882 reporting the signal.
1884 This avoids recursion while collecting (when a signal arrives
1885 midway, and the signal handler itself collects), which would trash
1886 the trace buffer. In case the user set a breakpoint in a signal
1887 handler, this avoids the backtrace showing the jump pad, etc..
1888 Most importantly, there are certain things we can't do safely if
1889 threads are stopped in a jump pad (or in its callee's). For
1892 - starting a new trace run. A thread still collecting the
1893 previous run, could trash the trace buffer when resumed. The trace
1894 buffer control structures would have been reset but the thread had
1895 no way to tell. The thread could even midway memcpy'ing to the
1896 buffer, which would mean that when resumed, it would clobber the
1897 trace buffer that had been set for a new run.
1899 - we can't rewrite/reuse the jump pads for new tracepoints
1900 safely. Say you do tstart while a thread is stopped midway while
1901 collecting. When the thread is later resumed, it finishes the
1902 collection, and returns to the jump pad, to execute the original
1903 instruction that was under the tracepoint jump at the time the
1904 older run had been started. If the jump pad had been rewritten
1905 since for something else in the new run, the thread would now
1906 execute the wrong / random instructions. */
1909 linux_stabilize_threads (void)
1911 struct thread_info
*save_inferior
;
1912 struct lwp_info
*lwp_stuck
;
1915 = (struct lwp_info
*) find_inferior (&all_lwps
,
1916 stuck_in_jump_pad_callback
, NULL
);
1917 if (lwp_stuck
!= NULL
)
1920 fprintf (stderr
, "can't stabilize, LWP %ld is stuck in jump pad\n",
1921 lwpid_of (lwp_stuck
));
1925 save_inferior
= current_inferior
;
1927 stabilizing_threads
= 1;
1930 for_each_inferior (&all_lwps
, move_out_of_jump_pad_callback
);
1932 /* Loop until all are stopped out of the jump pads. */
1933 while (find_inferior (&all_lwps
, lwp_running
, NULL
) != NULL
)
1935 struct target_waitstatus ourstatus
;
1936 struct lwp_info
*lwp
;
1939 /* Note that we go through the full wait even loop. While
1940 moving threads out of jump pad, we need to be able to step
1941 over internal breakpoints and such. */
1942 linux_wait_1 (minus_one_ptid
, &ourstatus
, 0);
1944 if (ourstatus
.kind
== TARGET_WAITKIND_STOPPED
)
1946 lwp
= get_thread_lwp (current_inferior
);
1951 if (ourstatus
.value
.sig
!= TARGET_SIGNAL_0
1952 || current_inferior
->last_resume_kind
== resume_stop
)
1954 wstat
= W_STOPCODE (target_signal_to_host (ourstatus
.value
.sig
));
1955 enqueue_one_deferred_signal (lwp
, &wstat
);
1960 find_inferior (&all_lwps
, unsuspend_one_lwp
, NULL
);
1962 stabilizing_threads
= 0;
1964 current_inferior
= save_inferior
;
1969 = (struct lwp_info
*) find_inferior (&all_lwps
,
1970 stuck_in_jump_pad_callback
, NULL
);
1971 if (lwp_stuck
!= NULL
)
1972 fprintf (stderr
, "couldn't stabilize, LWP %ld got stuck in jump pad\n",
1973 lwpid_of (lwp_stuck
));
1977 /* Wait for process, returns status. */
1980 linux_wait_1 (ptid_t ptid
,
1981 struct target_waitstatus
*ourstatus
, int target_options
)
1984 struct lwp_info
*event_child
;
1987 int step_over_finished
;
1988 int bp_explains_trap
;
1989 int maybe_internal_trap
;
1993 /* Translate generic target options into linux options. */
1995 if (target_options
& TARGET_WNOHANG
)
1999 bp_explains_trap
= 0;
2001 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2003 /* If we were only supposed to resume one thread, only wait for
2004 that thread - if it's still alive. If it died, however - which
2005 can happen if we're coming from the thread death case below -
2006 then we need to make sure we restart the other threads. We could
2007 pick a thread at random or restart all; restarting all is less
2010 && !ptid_equal (cont_thread
, null_ptid
)
2011 && !ptid_equal (cont_thread
, minus_one_ptid
))
2013 struct thread_info
*thread
;
2015 thread
= (struct thread_info
*) find_inferior_id (&all_threads
,
2018 /* No stepping, no signal - unless one is pending already, of course. */
2021 struct thread_resume resume_info
;
2022 resume_info
.thread
= minus_one_ptid
;
2023 resume_info
.kind
= resume_continue
;
2024 resume_info
.sig
= 0;
2025 linux_resume (&resume_info
, 1);
2031 if (ptid_equal (step_over_bkpt
, null_ptid
))
2032 pid
= linux_wait_for_event (ptid
, &w
, options
);
2036 fprintf (stderr
, "step_over_bkpt set [%s], doing a blocking wait\n",
2037 target_pid_to_str (step_over_bkpt
));
2038 pid
= linux_wait_for_event (step_over_bkpt
, &w
, options
& ~WNOHANG
);
2041 if (pid
== 0) /* only if TARGET_WNOHANG */
2044 event_child
= get_thread_lwp (current_inferior
);
2046 /* If we are waiting for a particular child, and it exited,
2047 linux_wait_for_event will return its exit status. Similarly if
2048 the last child exited. If this is not the last child, however,
2049 do not report it as exited until there is a 'thread exited' response
2050 available in the remote protocol. Instead, just wait for another event.
2051 This should be safe, because if the thread crashed we will already
2052 have reported the termination signal to GDB; that should stop any
2053 in-progress stepping operations, etc.
2055 Report the exit status of the last thread to exit. This matches
2056 LinuxThreads' behavior. */
2058 if (last_thread_of_process_p (current_inferior
))
2060 if (WIFEXITED (w
) || WIFSIGNALED (w
))
2064 ourstatus
->kind
= TARGET_WAITKIND_EXITED
;
2065 ourstatus
->value
.integer
= WEXITSTATUS (w
);
2069 "\nChild exited with retcode = %x \n",
2074 ourstatus
->kind
= TARGET_WAITKIND_SIGNALLED
;
2075 ourstatus
->value
.sig
= target_signal_from_host (WTERMSIG (w
));
2079 "\nChild terminated with signal = %x \n",
2084 return ptid_of (event_child
);
2089 if (!WIFSTOPPED (w
))
2093 /* If this event was not handled before, and is not a SIGTRAP, we
2094 report it. SIGILL and SIGSEGV are also treated as traps in case
2095 a breakpoint is inserted at the current PC. If this target does
2096 not support internal breakpoints at all, we also report the
2097 SIGTRAP without further processing; it's of no concern to us. */
2099 = (supports_breakpoints ()
2100 && (WSTOPSIG (w
) == SIGTRAP
2101 || ((WSTOPSIG (w
) == SIGILL
2102 || WSTOPSIG (w
) == SIGSEGV
)
2103 && (*the_low_target
.breakpoint_at
) (event_child
->stop_pc
))));
2105 if (maybe_internal_trap
)
2107 /* Handle anything that requires bookkeeping before deciding to
2108 report the event or continue waiting. */
2110 /* First check if we can explain the SIGTRAP with an internal
2111 breakpoint, or if we should possibly report the event to GDB.
2112 Do this before anything that may remove or insert a
2114 bp_explains_trap
= breakpoint_inserted_here (event_child
->stop_pc
);
2116 /* We have a SIGTRAP, possibly a step-over dance has just
2117 finished. If so, tweak the state machine accordingly,
2118 reinsert breakpoints and delete any reinsert (software
2119 single-step) breakpoints. */
2120 step_over_finished
= finish_step_over (event_child
);
2122 /* Now invoke the callbacks of any internal breakpoints there. */
2123 check_breakpoints (event_child
->stop_pc
);
2125 /* Handle tracepoint data collecting. This may overflow the
2126 trace buffer, and cause a tracing stop, removing
2128 trace_event
= handle_tracepoints (event_child
);
2130 if (bp_explains_trap
)
2132 /* If we stepped or ran into an internal breakpoint, we've
2133 already handled it. So next time we resume (from this
2134 PC), we should step over it. */
2136 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
2138 if (breakpoint_here (event_child
->stop_pc
))
2139 event_child
->need_step_over
= 1;
2144 /* We have some other signal, possibly a step-over dance was in
2145 progress, and it should be cancelled too. */
2146 step_over_finished
= finish_step_over (event_child
);
2149 /* We have all the data we need. Either report the event to GDB, or
2150 resume threads and keep waiting for more. */
2152 /* If we're collecting a fast tracepoint, finish the collection and
2153 move out of the jump pad before delivering a signal. See
2154 linux_stabilize_threads. */
2157 && WSTOPSIG (w
) != SIGTRAP
2158 && supports_fast_tracepoints ()
2159 && in_process_agent_loaded ())
2163 "Got signal %d for LWP %ld. Check if we need "
2164 "to defer or adjust it.\n",
2165 WSTOPSIG (w
), lwpid_of (event_child
));
2167 /* Allow debugging the jump pad itself. */
2168 if (current_inferior
->last_resume_kind
!= resume_step
2169 && maybe_move_out_of_jump_pad (event_child
, &w
))
2171 enqueue_one_deferred_signal (event_child
, &w
);
2175 "Signal %d for LWP %ld deferred (in jump pad)\n",
2176 WSTOPSIG (w
), lwpid_of (event_child
));
2178 linux_resume_one_lwp (event_child
, 0, 0, NULL
);
2183 if (event_child
->collecting_fast_tracepoint
)
2187 LWP %ld was trying to move out of the jump pad (%d). \
2188 Check if we're already there.\n",
2189 lwpid_of (event_child
),
2190 event_child
->collecting_fast_tracepoint
);
2194 event_child
->collecting_fast_tracepoint
2195 = linux_fast_tracepoint_collecting (event_child
, NULL
);
2197 if (event_child
->collecting_fast_tracepoint
!= 1)
2199 /* No longer need this breakpoint. */
2200 if (event_child
->exit_jump_pad_bkpt
!= NULL
)
2204 "No longer need exit-jump-pad bkpt; removing it."
2205 "stopping all threads momentarily.\n");
2207 /* Other running threads could hit this breakpoint.
2208 We don't handle moribund locations like GDB does,
2209 instead we always pause all threads when removing
2210 breakpoints, so that any step-over or
2211 decr_pc_after_break adjustment is always taken
2212 care of while the breakpoint is still
2214 stop_all_lwps (1, event_child
);
2215 cancel_breakpoints ();
2217 delete_breakpoint (event_child
->exit_jump_pad_bkpt
);
2218 event_child
->exit_jump_pad_bkpt
= NULL
;
2220 unstop_all_lwps (1, event_child
);
2222 gdb_assert (event_child
->suspended
>= 0);
2226 if (event_child
->collecting_fast_tracepoint
== 0)
2230 "fast tracepoint finished "
2231 "collecting successfully.\n");
2233 /* We may have a deferred signal to report. */
2234 if (dequeue_one_deferred_signal (event_child
, &w
))
2237 fprintf (stderr
, "dequeued one signal.\n");
2242 fprintf (stderr
, "no deferred signals.\n");
2244 if (stabilizing_threads
)
2246 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
2247 ourstatus
->value
.sig
= TARGET_SIGNAL_0
;
2248 return ptid_of (event_child
);
2254 /* Check whether GDB would be interested in this event. */
2256 /* If GDB is not interested in this signal, don't stop other
2257 threads, and don't report it to GDB. Just resume the inferior
2258 right away. We do this for threading-related signals as well as
2259 any that GDB specifically requested we ignore. But never ignore
2260 SIGSTOP if we sent it ourselves, and do not ignore signals when
2261 stepping - they may require special handling to skip the signal
2263 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
2266 && current_inferior
->last_resume_kind
!= resume_step
2268 #if defined (USE_THREAD_DB) && !defined (__ANDROID__)
2269 (current_process ()->private->thread_db
!= NULL
2270 && (WSTOPSIG (w
) == __SIGRTMIN
2271 || WSTOPSIG (w
) == __SIGRTMIN
+ 1))
2274 (pass_signals
[target_signal_from_host (WSTOPSIG (w
))]
2275 && !(WSTOPSIG (w
) == SIGSTOP
2276 && current_inferior
->last_resume_kind
== resume_stop
))))
2278 siginfo_t info
, *info_p
;
2281 fprintf (stderr
, "Ignored signal %d for LWP %ld.\n",
2282 WSTOPSIG (w
), lwpid_of (event_child
));
2284 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (event_child
), 0, &info
) == 0)
2288 linux_resume_one_lwp (event_child
, event_child
->stepping
,
2289 WSTOPSIG (w
), info_p
);
2293 /* If GDB wanted this thread to single step, we always want to
2294 report the SIGTRAP, and let GDB handle it. Watchpoints should
2295 always be reported. So should signals we can't explain. A
2296 SIGTRAP we can't explain could be a GDB breakpoint --- we may or
2297 not support Z0 breakpoints. If we do, we're be able to handle
2298 GDB breakpoints on top of internal breakpoints, by handling the
2299 internal breakpoint and still reporting the event to GDB. If we
2300 don't, we're out of luck, GDB won't see the breakpoint hit. */
2301 report_to_gdb
= (!maybe_internal_trap
2302 || current_inferior
->last_resume_kind
== resume_step
2303 || event_child
->stopped_by_watchpoint
2304 || (!step_over_finished
2305 && !bp_explains_trap
&& !trace_event
)
2306 || gdb_breakpoint_here (event_child
->stop_pc
));
2308 /* We found no reason GDB would want us to stop. We either hit one
2309 of our own breakpoints, or finished an internal step GDB
2310 shouldn't know about. */
2315 if (bp_explains_trap
)
2316 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
2317 if (step_over_finished
)
2318 fprintf (stderr
, "Step-over finished.\n");
2320 fprintf (stderr
, "Tracepoint event.\n");
2323 /* We're not reporting this breakpoint to GDB, so apply the
2324 decr_pc_after_break adjustment to the inferior's regcache
2327 if (the_low_target
.set_pc
!= NULL
)
2329 struct regcache
*regcache
2330 = get_thread_regcache (get_lwp_thread (event_child
), 1);
2331 (*the_low_target
.set_pc
) (regcache
, event_child
->stop_pc
);
2334 /* We may have finished stepping over a breakpoint. If so,
2335 we've stopped and suspended all LWPs momentarily except the
2336 stepping one. This is where we resume them all again. We're
2337 going to keep waiting, so use proceed, which handles stepping
2338 over the next breakpoint. */
2340 fprintf (stderr
, "proceeding all threads.\n");
2342 if (step_over_finished
)
2343 unsuspend_all_lwps (event_child
);
2345 proceed_all_lwps ();
2351 if (current_inferior
->last_resume_kind
== resume_step
)
2352 fprintf (stderr
, "GDB wanted to single-step, reporting event.\n");
2353 if (event_child
->stopped_by_watchpoint
)
2354 fprintf (stderr
, "Stopped by watchpoint.\n");
2355 if (gdb_breakpoint_here (event_child
->stop_pc
))
2356 fprintf (stderr
, "Stopped by GDB breakpoint.\n");
2358 fprintf (stderr
, "Hit a non-gdbserver trap event.\n");
2361 /* Alright, we're going to report a stop. */
2363 if (!non_stop
&& !stabilizing_threads
)
2365 /* In all-stop, stop all threads. */
2366 stop_all_lwps (0, NULL
);
2368 /* If we're not waiting for a specific LWP, choose an event LWP
2369 from among those that have had events. Giving equal priority
2370 to all LWPs that have had events helps prevent
2372 if (ptid_equal (ptid
, minus_one_ptid
))
2374 event_child
->status_pending_p
= 1;
2375 event_child
->status_pending
= w
;
2377 select_event_lwp (&event_child
);
2379 event_child
->status_pending_p
= 0;
2380 w
= event_child
->status_pending
;
2383 /* Now that we've selected our final event LWP, cancel any
2384 breakpoints in other LWPs that have hit a GDB breakpoint.
2385 See the comment in cancel_breakpoints_callback to find out
2387 find_inferior (&all_lwps
, cancel_breakpoints_callback
, event_child
);
2389 /* Stabilize threads (move out of jump pads). */
2390 stabilize_threads ();
2394 /* If we just finished a step-over, then all threads had been
2395 momentarily paused. In all-stop, that's fine, we want
2396 threads stopped by now anyway. In non-stop, we need to
2397 re-resume threads that GDB wanted to be running. */
2398 if (step_over_finished
)
2399 unstop_all_lwps (1, event_child
);
2402 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
2404 if (current_inferior
->last_resume_kind
== resume_stop
2405 && WSTOPSIG (w
) == SIGSTOP
)
2407 /* A thread that has been requested to stop by GDB with vCont;t,
2408 and it stopped cleanly, so report as SIG0. The use of
2409 SIGSTOP is an implementation detail. */
2410 ourstatus
->value
.sig
= TARGET_SIGNAL_0
;
2412 else if (current_inferior
->last_resume_kind
== resume_stop
2413 && WSTOPSIG (w
) != SIGSTOP
)
2415 /* A thread that has been requested to stop by GDB with vCont;t,
2416 but, it stopped for other reasons. */
2417 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
2421 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
2424 gdb_assert (ptid_equal (step_over_bkpt
, null_ptid
));
2427 fprintf (stderr
, "linux_wait ret = %s, %d, %d\n",
2428 target_pid_to_str (ptid_of (event_child
)),
2430 ourstatus
->value
.sig
);
2432 return ptid_of (event_child
);
2435 /* Get rid of any pending event in the pipe. */
2437 async_file_flush (void)
2443 ret
= read (linux_event_pipe
[0], &buf
, 1);
2444 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
2447 /* Put something in the pipe, so the event loop wakes up. */
2449 async_file_mark (void)
2453 async_file_flush ();
2456 ret
= write (linux_event_pipe
[1], "+", 1);
2457 while (ret
== 0 || (ret
== -1 && errno
== EINTR
));
2459 /* Ignore EAGAIN. If the pipe is full, the event loop will already
2460 be awakened anyway. */
2464 linux_wait (ptid_t ptid
,
2465 struct target_waitstatus
*ourstatus
, int target_options
)
2470 fprintf (stderr
, "linux_wait: [%s]\n", target_pid_to_str (ptid
));
2472 /* Flush the async file first. */
2473 if (target_is_async_p ())
2474 async_file_flush ();
2476 event_ptid
= linux_wait_1 (ptid
, ourstatus
, target_options
);
2478 /* If at least one stop was reported, there may be more. A single
2479 SIGCHLD can signal more than one child stop. */
2480 if (target_is_async_p ()
2481 && (target_options
& TARGET_WNOHANG
) != 0
2482 && !ptid_equal (event_ptid
, null_ptid
))
2488 /* Send a signal to an LWP. */
2491 kill_lwp (unsigned long lwpid
, int signo
)
2493 /* Use tkill, if possible, in case we are using nptl threads. If tkill
2494 fails, then we are not using nptl threads and we should be using kill. */
2498 static int tkill_failed
;
2505 ret
= syscall (__NR_tkill
, lwpid
, signo
);
2506 if (errno
!= ENOSYS
)
2513 return kill (lwpid
, signo
);
2517 linux_stop_lwp (struct lwp_info
*lwp
)
2523 send_sigstop (struct lwp_info
*lwp
)
2527 pid
= lwpid_of (lwp
);
2529 /* If we already have a pending stop signal for this process, don't
2531 if (lwp
->stop_expected
)
2534 fprintf (stderr
, "Have pending sigstop for lwp %d\n", pid
);
2540 fprintf (stderr
, "Sending sigstop to lwp %d\n", pid
);
2542 lwp
->stop_expected
= 1;
2543 kill_lwp (pid
, SIGSTOP
);
2547 send_sigstop_callback (struct inferior_list_entry
*entry
, void *except
)
2549 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2551 /* Ignore EXCEPT. */
2562 /* Increment the suspend count of an LWP, and stop it, if not stopped
2565 suspend_and_send_sigstop_callback (struct inferior_list_entry
*entry
,
2568 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2570 /* Ignore EXCEPT. */
2576 return send_sigstop_callback (entry
, except
);
2580 mark_lwp_dead (struct lwp_info
*lwp
, int wstat
)
2582 /* It's dead, really. */
2585 /* Store the exit status for later. */
2586 lwp
->status_pending_p
= 1;
2587 lwp
->status_pending
= wstat
;
2589 /* Prevent trying to stop it. */
2592 /* No further stops are expected from a dead lwp. */
2593 lwp
->stop_expected
= 0;
2597 wait_for_sigstop (struct inferior_list_entry
*entry
)
2599 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2600 struct thread_info
*saved_inferior
;
2609 fprintf (stderr
, "wait_for_sigstop: LWP %ld already stopped\n",
2614 saved_inferior
= current_inferior
;
2615 if (saved_inferior
!= NULL
)
2616 saved_tid
= ((struct inferior_list_entry
*) saved_inferior
)->id
;
2618 saved_tid
= null_ptid
; /* avoid bogus unused warning */
2620 ptid
= lwp
->head
.id
;
2623 fprintf (stderr
, "wait_for_sigstop: pulling one event\n");
2625 pid
= linux_wait_for_event (ptid
, &wstat
, __WALL
);
2627 /* If we stopped with a non-SIGSTOP signal, save it for later
2628 and record the pending SIGSTOP. If the process exited, just
2630 if (WIFSTOPPED (wstat
))
2633 fprintf (stderr
, "LWP %ld stopped with signal %d\n",
2634 lwpid_of (lwp
), WSTOPSIG (wstat
));
2636 if (WSTOPSIG (wstat
) != SIGSTOP
)
2639 fprintf (stderr
, "LWP %ld stopped with non-sigstop status %06x\n",
2640 lwpid_of (lwp
), wstat
);
2642 lwp
->status_pending_p
= 1;
2643 lwp
->status_pending
= wstat
;
2649 fprintf (stderr
, "Process %d exited while stopping LWPs\n", pid
);
2651 lwp
= find_lwp_pid (pid_to_ptid (pid
));
2654 /* Leave this status pending for the next time we're able to
2655 report it. In the mean time, we'll report this lwp as
2656 dead to GDB, so GDB doesn't try to read registers and
2657 memory from it. This can only happen if this was the
2658 last thread of the process; otherwise, PID is removed
2659 from the thread tables before linux_wait_for_event
2661 mark_lwp_dead (lwp
, wstat
);
2665 if (saved_inferior
== NULL
|| linux_thread_alive (saved_tid
))
2666 current_inferior
= saved_inferior
;
2670 fprintf (stderr
, "Previously current thread died.\n");
2674 /* We can't change the current inferior behind GDB's back,
2675 otherwise, a subsequent command may apply to the wrong
2677 current_inferior
= NULL
;
2681 /* Set a valid thread as current. */
2682 set_desired_inferior (0);
2687 /* Returns true if LWP ENTRY is stopped in a jump pad, and we can't
2688 move it out, because we need to report the stop event to GDB. For
2689 example, if the user puts a breakpoint in the jump pad, it's
2690 because she wants to debug it. */
2693 stuck_in_jump_pad_callback (struct inferior_list_entry
*entry
, void *data
)
2695 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2696 struct thread_info
*thread
= get_lwp_thread (lwp
);
2698 gdb_assert (lwp
->suspended
== 0);
2699 gdb_assert (lwp
->stopped
);
2701 /* Allow debugging the jump pad, gdb_collect, etc.. */
2702 return (supports_fast_tracepoints ()
2703 && in_process_agent_loaded ()
2704 && (gdb_breakpoint_here (lwp
->stop_pc
)
2705 || lwp
->stopped_by_watchpoint
2706 || thread
->last_resume_kind
== resume_step
)
2707 && linux_fast_tracepoint_collecting (lwp
, NULL
));
2711 move_out_of_jump_pad_callback (struct inferior_list_entry
*entry
)
2713 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2714 struct thread_info
*thread
= get_lwp_thread (lwp
);
2717 gdb_assert (lwp
->suspended
== 0);
2718 gdb_assert (lwp
->stopped
);
2720 wstat
= lwp
->status_pending_p
? &lwp
->status_pending
: NULL
;
2722 /* Allow debugging the jump pad, gdb_collect, etc. */
2723 if (!gdb_breakpoint_here (lwp
->stop_pc
)
2724 && !lwp
->stopped_by_watchpoint
2725 && thread
->last_resume_kind
!= resume_step
2726 && maybe_move_out_of_jump_pad (lwp
, wstat
))
2730 "LWP %ld needs stabilizing (in jump pad)\n",
2735 lwp
->status_pending_p
= 0;
2736 enqueue_one_deferred_signal (lwp
, wstat
);
2740 "Signal %d for LWP %ld deferred "
2742 WSTOPSIG (*wstat
), lwpid_of (lwp
));
2745 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
2752 lwp_running (struct inferior_list_entry
*entry
, void *data
)
2754 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2763 /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
2764 If SUSPEND, then also increase the suspend count of every LWP,
2768 stop_all_lwps (int suspend
, struct lwp_info
*except
)
2770 stopping_threads
= 1;
2773 find_inferior (&all_lwps
, suspend_and_send_sigstop_callback
, except
);
2775 find_inferior (&all_lwps
, send_sigstop_callback
, except
);
2776 for_each_inferior (&all_lwps
, wait_for_sigstop
);
2777 stopping_threads
= 0;
2780 /* Resume execution of the inferior process.
2781 If STEP is nonzero, single-step it.
2782 If SIGNAL is nonzero, give it that signal. */
2785 linux_resume_one_lwp (struct lwp_info
*lwp
,
2786 int step
, int signal
, siginfo_t
*info
)
2788 struct thread_info
*saved_inferior
;
2789 int fast_tp_collecting
;
2791 if (lwp
->stopped
== 0)
2794 fast_tp_collecting
= lwp
->collecting_fast_tracepoint
;
2796 gdb_assert (!stabilizing_threads
|| fast_tp_collecting
);
2798 /* Cancel actions that rely on GDB not changing the PC (e.g., the
2799 user used the "jump" command, or "set $pc = foo"). */
2800 if (lwp
->stop_pc
!= get_pc (lwp
))
2802 /* Collecting 'while-stepping' actions doesn't make sense
2804 release_while_stepping_state_list (get_lwp_thread (lwp
));
2807 /* If we have pending signals or status, and a new signal, enqueue the
2808 signal. Also enqueue the signal if we are waiting to reinsert a
2809 breakpoint; it will be picked up again below. */
2811 && (lwp
->status_pending_p
2812 || lwp
->pending_signals
!= NULL
2813 || lwp
->bp_reinsert
!= 0
2814 || fast_tp_collecting
))
2816 struct pending_signals
*p_sig
;
2817 p_sig
= xmalloc (sizeof (*p_sig
));
2818 p_sig
->prev
= lwp
->pending_signals
;
2819 p_sig
->signal
= signal
;
2821 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
2823 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
2824 lwp
->pending_signals
= p_sig
;
2827 if (lwp
->status_pending_p
)
2830 fprintf (stderr
, "Not resuming lwp %ld (%s, signal %d, stop %s);"
2831 " has pending status\n",
2832 lwpid_of (lwp
), step
? "step" : "continue", signal
,
2833 lwp
->stop_expected
? "expected" : "not expected");
2837 saved_inferior
= current_inferior
;
2838 current_inferior
= get_lwp_thread (lwp
);
2841 fprintf (stderr
, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
2842 lwpid_of (lwp
), step
? "step" : "continue", signal
,
2843 lwp
->stop_expected
? "expected" : "not expected");
2845 /* This bit needs some thinking about. If we get a signal that
2846 we must report while a single-step reinsert is still pending,
2847 we often end up resuming the thread. It might be better to
2848 (ew) allow a stack of pending events; then we could be sure that
2849 the reinsert happened right away and not lose any signals.
2851 Making this stack would also shrink the window in which breakpoints are
2852 uninserted (see comment in linux_wait_for_lwp) but not enough for
2853 complete correctness, so it won't solve that problem. It may be
2854 worthwhile just to solve this one, however. */
2855 if (lwp
->bp_reinsert
!= 0)
2858 fprintf (stderr
, " pending reinsert at 0x%s\n",
2859 paddress (lwp
->bp_reinsert
));
2861 if (lwp
->bp_reinsert
!= 0 && can_hardware_single_step ())
2863 if (fast_tp_collecting
== 0)
2866 fprintf (stderr
, "BAD - reinserting but not stepping.\n");
2868 fprintf (stderr
, "BAD - reinserting and suspended(%d).\n",
2875 /* Postpone any pending signal. It was enqueued above. */
2879 if (fast_tp_collecting
== 1)
2883 lwp %ld wants to get out of fast tracepoint jump pad (exit-jump-pad-bkpt)\n",
2886 /* Postpone any pending signal. It was enqueued above. */
2889 else if (fast_tp_collecting
== 2)
2893 lwp %ld wants to get out of fast tracepoint jump pad single-stepping\n",
2896 if (can_hardware_single_step ())
2899 fatal ("moving out of jump pad single-stepping"
2900 " not implemented on this target");
2902 /* Postpone any pending signal. It was enqueued above. */
2906 /* If we have while-stepping actions in this thread set it stepping.
2907 If we have a signal to deliver, it may or may not be set to
2908 SIG_IGN, we don't know. Assume so, and allow collecting
2909 while-stepping into a signal handler. A possible smart thing to
2910 do would be to set an internal breakpoint at the signal return
2911 address, continue, and carry on catching this while-stepping
2912 action only when that breakpoint is hit. A future
2914 if (get_lwp_thread (lwp
)->while_stepping
!= NULL
2915 && can_hardware_single_step ())
2919 "lwp %ld has a while-stepping action -> forcing step.\n",
2924 if (debug_threads
&& the_low_target
.get_pc
!= NULL
)
2926 struct regcache
*regcache
= get_thread_regcache (current_inferior
, 1);
2927 CORE_ADDR pc
= (*the_low_target
.get_pc
) (regcache
);
2928 fprintf (stderr
, " resuming from pc 0x%lx\n", (long) pc
);
2931 /* If we have pending signals, consume one unless we are trying to
2932 reinsert a breakpoint or we're trying to finish a fast tracepoint
2934 if (lwp
->pending_signals
!= NULL
2935 && lwp
->bp_reinsert
== 0
2936 && fast_tp_collecting
== 0)
2938 struct pending_signals
**p_sig
;
2940 p_sig
= &lwp
->pending_signals
;
2941 while ((*p_sig
)->prev
!= NULL
)
2942 p_sig
= &(*p_sig
)->prev
;
2944 signal
= (*p_sig
)->signal
;
2945 if ((*p_sig
)->info
.si_signo
!= 0)
2946 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &(*p_sig
)->info
);
2952 if (the_low_target
.prepare_to_resume
!= NULL
)
2953 the_low_target
.prepare_to_resume (lwp
);
2955 regcache_invalidate_one ((struct inferior_list_entry
*)
2956 get_lwp_thread (lwp
));
2959 lwp
->stopped_by_watchpoint
= 0;
2960 lwp
->stepping
= step
;
2961 ptrace (step
? PTRACE_SINGLESTEP
: PTRACE_CONT
, lwpid_of (lwp
), 0,
2962 /* Coerce to a uintptr_t first to avoid potential gcc warning
2963 of coercing an 8 byte integer to a 4 byte pointer. */
2964 (PTRACE_ARG4_TYPE
) (uintptr_t) signal
);
2966 current_inferior
= saved_inferior
;
2969 /* ESRCH from ptrace either means that the thread was already
2970 running (an error) or that it is gone (a race condition). If
2971 it's gone, we will get a notification the next time we wait,
2972 so we can ignore the error. We could differentiate these
2973 two, but it's tricky without waiting; the thread still exists
2974 as a zombie, so sending it signal 0 would succeed. So just
2979 perror_with_name ("ptrace");
2983 struct thread_resume_array
2985 struct thread_resume
*resume
;
2989 /* This function is called once per thread. We look up the thread
2990 in RESUME_PTR, and mark the thread with a pointer to the appropriate
2993 This algorithm is O(threads * resume elements), but resume elements
2994 is small (and will remain small at least until GDB supports thread
2997 linux_set_resume_request (struct inferior_list_entry
*entry
, void *arg
)
2999 struct lwp_info
*lwp
;
3000 struct thread_info
*thread
;
3002 struct thread_resume_array
*r
;
3004 thread
= (struct thread_info
*) entry
;
3005 lwp
= get_thread_lwp (thread
);
3008 for (ndx
= 0; ndx
< r
->n
; ndx
++)
3010 ptid_t ptid
= r
->resume
[ndx
].thread
;
3011 if (ptid_equal (ptid
, minus_one_ptid
)
3012 || ptid_equal (ptid
, entry
->id
)
3013 || (ptid_is_pid (ptid
)
3014 && (ptid_get_pid (ptid
) == pid_of (lwp
)))
3015 || (ptid_get_lwp (ptid
) == -1
3016 && (ptid_get_pid (ptid
) == pid_of (lwp
))))
3018 if (r
->resume
[ndx
].kind
== resume_stop
3019 && thread
->last_resume_kind
== resume_stop
)
3022 fprintf (stderr
, "already %s LWP %ld at GDB's request\n",
3023 thread
->last_status
.kind
== TARGET_WAITKIND_STOPPED
3031 lwp
->resume
= &r
->resume
[ndx
];
3032 thread
->last_resume_kind
= lwp
->resume
->kind
;
3034 /* If we had a deferred signal to report, dequeue one now.
3035 This can happen if LWP gets more than one signal while
3036 trying to get out of a jump pad. */
3038 && !lwp
->status_pending_p
3039 && dequeue_one_deferred_signal (lwp
, &lwp
->status_pending
))
3041 lwp
->status_pending_p
= 1;
3045 "Dequeueing deferred signal %d for LWP %ld, "
3046 "leaving status pending.\n",
3047 WSTOPSIG (lwp
->status_pending
), lwpid_of (lwp
));
3054 /* No resume action for this thread. */
3061 /* Set *FLAG_P if this lwp has an interesting status pending. */
3063 resume_status_pending_p (struct inferior_list_entry
*entry
, void *flag_p
)
3065 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
3067 /* LWPs which will not be resumed are not interesting, because
3068 we might not wait for them next time through linux_wait. */
3069 if (lwp
->resume
== NULL
)
3072 if (lwp
->status_pending_p
)
3073 * (int *) flag_p
= 1;
3078 /* Return 1 if this lwp that GDB wants running is stopped at an
3079 internal breakpoint that we need to step over. It assumes that any
3080 required STOP_PC adjustment has already been propagated to the
3081 inferior's regcache. */
3084 need_step_over_p (struct inferior_list_entry
*entry
, void *dummy
)
3086 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
3087 struct thread_info
*thread
;
3088 struct thread_info
*saved_inferior
;
3091 /* LWPs which will not be resumed are not interesting, because we
3092 might not wait for them next time through linux_wait. */
3098 "Need step over [LWP %ld]? Ignoring, not stopped\n",
3103 thread
= get_lwp_thread (lwp
);
3105 if (thread
->last_resume_kind
== resume_stop
)
3109 "Need step over [LWP %ld]? Ignoring, should remain stopped\n",
3114 gdb_assert (lwp
->suspended
>= 0);
3120 "Need step over [LWP %ld]? Ignoring, suspended\n",
3125 if (!lwp
->need_step_over
)
3129 "Need step over [LWP %ld]? No\n", lwpid_of (lwp
));
3132 if (lwp
->status_pending_p
)
3136 "Need step over [LWP %ld]? Ignoring, has pending status.\n",
3141 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
3145 /* If the PC has changed since we stopped, then don't do anything,
3146 and let the breakpoint/tracepoint be hit. This happens if, for
3147 instance, GDB handled the decr_pc_after_break subtraction itself,
3148 GDB is OOL stepping this thread, or the user has issued a "jump"
3149 command, or poked thread's registers herself. */
3150 if (pc
!= lwp
->stop_pc
)
3154 "Need step over [LWP %ld]? Cancelling, PC was changed. "
3155 "Old stop_pc was 0x%s, PC is now 0x%s\n",
3156 lwpid_of (lwp
), paddress (lwp
->stop_pc
), paddress (pc
));
3158 lwp
->need_step_over
= 0;
3162 saved_inferior
= current_inferior
;
3163 current_inferior
= thread
;
3165 /* We can only step over breakpoints we know about. */
3166 if (breakpoint_here (pc
) || fast_tracepoint_jump_here (pc
))
3168 /* Don't step over a breakpoint that GDB expects to hit
3170 if (gdb_breakpoint_here (pc
))
3174 "Need step over [LWP %ld]? yes, but found"
3175 " GDB breakpoint at 0x%s; skipping step over\n",
3176 lwpid_of (lwp
), paddress (pc
));
3178 current_inferior
= saved_inferior
;
3185 "Need step over [LWP %ld]? yes, "
3186 "found breakpoint at 0x%s\n",
3187 lwpid_of (lwp
), paddress (pc
));
3189 /* We've found an lwp that needs stepping over --- return 1 so
3190 that find_inferior stops looking. */
3191 current_inferior
= saved_inferior
;
3193 /* If the step over is cancelled, this is set again. */
3194 lwp
->need_step_over
= 0;
3199 current_inferior
= saved_inferior
;
3203 "Need step over [LWP %ld]? No, no breakpoint found at 0x%s\n",
3204 lwpid_of (lwp
), paddress (pc
));
3209 /* Start a step-over operation on LWP. When LWP stopped at a
3210 breakpoint, to make progress, we need to remove the breakpoint out
3211 of the way. If we let other threads run while we do that, they may
3212 pass by the breakpoint location and miss hitting it. To avoid
3213 that, a step-over momentarily stops all threads while LWP is
3214 single-stepped while the breakpoint is temporarily uninserted from
3215 the inferior. When the single-step finishes, we reinsert the
3216 breakpoint, and let all threads that are supposed to be running,
3219 On targets that don't support hardware single-step, we don't
3220 currently support full software single-stepping. Instead, we only
3221 support stepping over the thread event breakpoint, by asking the
3222 low target where to place a reinsert breakpoint. Since this
3223 routine assumes the breakpoint being stepped over is a thread event
3224 breakpoint, it usually assumes the return address of the current
3225 function is a good enough place to set the reinsert breakpoint. */
3228 start_step_over (struct lwp_info
*lwp
)
3230 struct thread_info
*saved_inferior
;
3236 "Starting step-over on LWP %ld. Stopping all threads\n",
3239 stop_all_lwps (1, lwp
);
3240 gdb_assert (lwp
->suspended
== 0);
3243 fprintf (stderr
, "Done stopping all threads for step-over.\n");
3245 /* Note, we should always reach here with an already adjusted PC,
3246 either by GDB (if we're resuming due to GDB's request), or by our
3247 caller, if we just finished handling an internal breakpoint GDB
3248 shouldn't care about. */
3251 saved_inferior
= current_inferior
;
3252 current_inferior
= get_lwp_thread (lwp
);
3254 lwp
->bp_reinsert
= pc
;
3255 uninsert_breakpoints_at (pc
);
3256 uninsert_fast_tracepoint_jumps_at (pc
);
3258 if (can_hardware_single_step ())
3264 CORE_ADDR raddr
= (*the_low_target
.breakpoint_reinsert_addr
) ();
3265 set_reinsert_breakpoint (raddr
);
3269 current_inferior
= saved_inferior
;
3271 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
3273 /* Require next event from this LWP. */
3274 step_over_bkpt
= lwp
->head
.id
;
3278 /* Finish a step-over. Reinsert the breakpoint we had uninserted in
3279 start_step_over, if still there, and delete any reinsert
3280 breakpoints we've set, on non hardware single-step targets. */
3283 finish_step_over (struct lwp_info
*lwp
)
3285 if (lwp
->bp_reinsert
!= 0)
3288 fprintf (stderr
, "Finished step over.\n");
3290 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
3291 may be no breakpoint to reinsert there by now. */
3292 reinsert_breakpoints_at (lwp
->bp_reinsert
);
3293 reinsert_fast_tracepoint_jumps_at (lwp
->bp_reinsert
);
3295 lwp
->bp_reinsert
= 0;
3297 /* Delete any software-single-step reinsert breakpoints. No
3298 longer needed. We don't have to worry about other threads
3299 hitting this trap, and later not being able to explain it,
3300 because we were stepping over a breakpoint, and we hold all
3301 threads but LWP stopped while doing that. */
3302 if (!can_hardware_single_step ())
3303 delete_reinsert_breakpoints ();
3305 step_over_bkpt
= null_ptid
;
3312 /* This function is called once per thread. We check the thread's resume
3313 request, which will tell us whether to resume, step, or leave the thread
3314 stopped; and what signal, if any, it should be sent.
3316 For threads which we aren't explicitly told otherwise, we preserve
3317 the stepping flag; this is used for stepping over gdbserver-placed
3320 If pending_flags was set in any thread, we queue any needed
3321 signals, since we won't actually resume. We already have a pending
3322 event to report, so we don't need to preserve any step requests;
3323 they should be re-issued if necessary. */
3326 linux_resume_one_thread (struct inferior_list_entry
*entry
, void *arg
)
3328 struct lwp_info
*lwp
;
3329 struct thread_info
*thread
;
3331 int leave_all_stopped
= * (int *) arg
;
3334 thread
= (struct thread_info
*) entry
;
3335 lwp
= get_thread_lwp (thread
);
3337 if (lwp
->resume
== NULL
)
3340 if (lwp
->resume
->kind
== resume_stop
)
3343 fprintf (stderr
, "resume_stop request for LWP %ld\n", lwpid_of (lwp
));
3348 fprintf (stderr
, "stopping LWP %ld\n", lwpid_of (lwp
));
3350 /* Stop the thread, and wait for the event asynchronously,
3351 through the event loop. */
3357 fprintf (stderr
, "already stopped LWP %ld\n",
3360 /* The LWP may have been stopped in an internal event that
3361 was not meant to be notified back to GDB (e.g., gdbserver
3362 breakpoint), so we should be reporting a stop event in
3365 /* If the thread already has a pending SIGSTOP, this is a
3366 no-op. Otherwise, something later will presumably resume
3367 the thread and this will cause it to cancel any pending
3368 operation, due to last_resume_kind == resume_stop. If
3369 the thread already has a pending status to report, we
3370 will still report it the next time we wait - see
3371 status_pending_p_callback. */
3373 /* If we already have a pending signal to report, then
3374 there's no need to queue a SIGSTOP, as this means we're
3375 midway through moving the LWP out of the jumppad, and we
3376 will report the pending signal as soon as that is
3378 if (lwp
->pending_signals_to_report
== NULL
)
3382 /* For stop requests, we're done. */
3384 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
3388 /* If this thread which is about to be resumed has a pending status,
3389 then don't resume any threads - we can just report the pending
3390 status. Make sure to queue any signals that would otherwise be
3391 sent. In all-stop mode, we do this decision based on if *any*
3392 thread has a pending status. If there's a thread that needs the
3393 step-over-breakpoint dance, then don't resume any other thread
3394 but that particular one. */
3395 leave_pending
= (lwp
->status_pending_p
|| leave_all_stopped
);
3400 fprintf (stderr
, "resuming LWP %ld\n", lwpid_of (lwp
));
3402 step
= (lwp
->resume
->kind
== resume_step
);
3403 linux_resume_one_lwp (lwp
, step
, lwp
->resume
->sig
, NULL
);
3408 fprintf (stderr
, "leaving LWP %ld stopped\n", lwpid_of (lwp
));
3410 /* If we have a new signal, enqueue the signal. */
3411 if (lwp
->resume
->sig
!= 0)
3413 struct pending_signals
*p_sig
;
3414 p_sig
= xmalloc (sizeof (*p_sig
));
3415 p_sig
->prev
= lwp
->pending_signals
;
3416 p_sig
->signal
= lwp
->resume
->sig
;
3417 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
3419 /* If this is the same signal we were previously stopped by,
3420 make sure to queue its siginfo. We can ignore the return
3421 value of ptrace; if it fails, we'll skip
3422 PTRACE_SETSIGINFO. */
3423 if (WIFSTOPPED (lwp
->last_status
)
3424 && WSTOPSIG (lwp
->last_status
) == lwp
->resume
->sig
)
3425 ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &p_sig
->info
);
3427 lwp
->pending_signals
= p_sig
;
3431 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
3437 linux_resume (struct thread_resume
*resume_info
, size_t n
)
3439 struct thread_resume_array array
= { resume_info
, n
};
3440 struct lwp_info
*need_step_over
= NULL
;
3442 int leave_all_stopped
;
3444 find_inferior (&all_threads
, linux_set_resume_request
, &array
);
3446 /* If there is a thread which would otherwise be resumed, which has
3447 a pending status, then don't resume any threads - we can just
3448 report the pending status. Make sure to queue any signals that
3449 would otherwise be sent. In non-stop mode, we'll apply this
3450 logic to each thread individually. We consume all pending events
3451 before considering to start a step-over (in all-stop). */
3454 find_inferior (&all_lwps
, resume_status_pending_p
, &any_pending
);
3456 /* If there is a thread which would otherwise be resumed, which is
3457 stopped at a breakpoint that needs stepping over, then don't
3458 resume any threads - have it step over the breakpoint with all
3459 other threads stopped, then resume all threads again. Make sure
3460 to queue any signals that would otherwise be delivered or
3462 if (!any_pending
&& supports_breakpoints ())
3464 = (struct lwp_info
*) find_inferior (&all_lwps
,
3465 need_step_over_p
, NULL
);
3467 leave_all_stopped
= (need_step_over
!= NULL
|| any_pending
);
3471 if (need_step_over
!= NULL
)
3472 fprintf (stderr
, "Not resuming all, need step over\n");
3473 else if (any_pending
)
3475 "Not resuming, all-stop and found "
3476 "an LWP with pending status\n");
3478 fprintf (stderr
, "Resuming, no pending status or step over needed\n");
3481 /* Even if we're leaving threads stopped, queue all signals we'd
3482 otherwise deliver. */
3483 find_inferior (&all_threads
, linux_resume_one_thread
, &leave_all_stopped
);
3486 start_step_over (need_step_over
);
3489 /* This function is called once per thread. We check the thread's
3490 last resume request, which will tell us whether to resume, step, or
3491 leave the thread stopped. Any signal the client requested to be
3492 delivered has already been enqueued at this point.
3494 If any thread that GDB wants running is stopped at an internal
3495 breakpoint that needs stepping over, we start a step-over operation
3496 on that particular thread, and leave all others stopped. */
3499 proceed_one_lwp (struct inferior_list_entry
*entry
, void *except
)
3501 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
3502 struct thread_info
*thread
;
3510 "proceed_one_lwp: lwp %ld\n", lwpid_of (lwp
));
3515 fprintf (stderr
, " LWP %ld already running\n", lwpid_of (lwp
));
3519 thread
= get_lwp_thread (lwp
);
3521 if (thread
->last_resume_kind
== resume_stop
3522 && thread
->last_status
.kind
!= TARGET_WAITKIND_IGNORE
)
3525 fprintf (stderr
, " client wants LWP to remain %ld stopped\n",
3530 if (lwp
->status_pending_p
)
3533 fprintf (stderr
, " LWP %ld has pending status, leaving stopped\n",
3538 gdb_assert (lwp
->suspended
>= 0);
3543 fprintf (stderr
, " LWP %ld is suspended\n", lwpid_of (lwp
));
3547 if (thread
->last_resume_kind
== resume_stop
3548 && lwp
->pending_signals_to_report
== NULL
3549 && lwp
->collecting_fast_tracepoint
== 0)
3551 /* We haven't reported this LWP as stopped yet (otherwise, the
3552 last_status.kind check above would catch it, and we wouldn't
3553 reach here. This LWP may have been momentarily paused by a
3554 stop_all_lwps call while handling for example, another LWP's
3555 step-over. In that case, the pending expected SIGSTOP signal
3556 that was queued at vCont;t handling time will have already
3557 been consumed by wait_for_sigstop, and so we need to requeue
3558 another one here. Note that if the LWP already has a SIGSTOP
3559 pending, this is a no-op. */
3563 "Client wants LWP %ld to stop. "
3564 "Making sure it has a SIGSTOP pending\n",
3570 step
= thread
->last_resume_kind
== resume_step
;
3571 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
3576 unsuspend_and_proceed_one_lwp (struct inferior_list_entry
*entry
, void *except
)
3578 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
3584 gdb_assert (lwp
->suspended
>= 0);
3586 return proceed_one_lwp (entry
, except
);
3589 /* When we finish a step-over, set threads running again. If there's
3590 another thread that may need a step-over, now's the time to start
3591 it. Eventually, we'll move all threads past their breakpoints. */
3594 proceed_all_lwps (void)
3596 struct lwp_info
*need_step_over
;
3598 /* If there is a thread which would otherwise be resumed, which is
3599 stopped at a breakpoint that needs stepping over, then don't
3600 resume any threads - have it step over the breakpoint with all
3601 other threads stopped, then resume all threads again. */
3603 if (supports_breakpoints ())
3606 = (struct lwp_info
*) find_inferior (&all_lwps
,
3607 need_step_over_p
, NULL
);
3609 if (need_step_over
!= NULL
)
3612 fprintf (stderr
, "proceed_all_lwps: found "
3613 "thread %ld needing a step-over\n",
3614 lwpid_of (need_step_over
));
3616 start_step_over (need_step_over
);
3622 fprintf (stderr
, "Proceeding, no step-over needed\n");
3624 find_inferior (&all_lwps
, proceed_one_lwp
, NULL
);
3627 /* Stopped LWPs that the client wanted to be running, that don't have
3628 pending statuses, are set to run again, except for EXCEPT, if not
3629 NULL. This undoes a stop_all_lwps call. */
3632 unstop_all_lwps (int unsuspend
, struct lwp_info
*except
)
3638 "unstopping all lwps, except=(LWP %ld)\n", lwpid_of (except
));
3641 "unstopping all lwps\n");
3645 find_inferior (&all_lwps
, unsuspend_and_proceed_one_lwp
, except
);
3647 find_inferior (&all_lwps
, proceed_one_lwp
, except
);
3650 #ifdef HAVE_LINUX_USRREGS
3653 register_addr (int regnum
)
3657 if (regnum
< 0 || regnum
>= the_low_target
.num_regs
)
3658 error ("Invalid register number %d.", regnum
);
3660 addr
= the_low_target
.regmap
[regnum
];
3665 /* Fetch one register. */
3667 fetch_register (struct regcache
*regcache
, int regno
)
3674 if (regno
>= the_low_target
.num_regs
)
3676 if ((*the_low_target
.cannot_fetch_register
) (regno
))
3679 regaddr
= register_addr (regno
);
3683 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3684 size
= ((register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
3685 & - sizeof (PTRACE_XFER_TYPE
));
3686 buf
= alloca (size
);
3687 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
3690 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
3691 ptrace (PTRACE_PEEKUSER
, pid
,
3692 /* Coerce to a uintptr_t first to avoid potential gcc warning
3693 of coercing an 8 byte integer to a 4 byte pointer. */
3694 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
, 0);
3695 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
3697 error ("reading register %d: %s", regno
, strerror (errno
));
3700 if (the_low_target
.supply_ptrace_register
)
3701 the_low_target
.supply_ptrace_register (regcache
, regno
, buf
);
3703 supply_register (regcache
, regno
, buf
);
3706 /* Fetch all registers, or just one, from the child process. */
3708 usr_fetch_inferior_registers (struct regcache
*regcache
, int regno
)
3711 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
3712 fetch_register (regcache
, regno
);
3714 fetch_register (regcache
, regno
);
3717 /* Store our register values back into the inferior.
3718 If REGNO is -1, do this for all registers.
3719 Otherwise, REGNO specifies which register (so we can save time). */
3721 usr_store_inferior_registers (struct regcache
*regcache
, int regno
)
3730 if (regno
>= the_low_target
.num_regs
)
3733 if ((*the_low_target
.cannot_store_register
) (regno
) == 1)
3736 regaddr
= register_addr (regno
);
3740 size
= (register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
3741 & - sizeof (PTRACE_XFER_TYPE
);
3742 buf
= alloca (size
);
3743 memset (buf
, 0, size
);
3745 if (the_low_target
.collect_ptrace_register
)
3746 the_low_target
.collect_ptrace_register (regcache
, regno
, buf
);
3748 collect_register (regcache
, regno
, buf
);
3750 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3751 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
3754 ptrace (PTRACE_POKEUSER
, pid
,
3755 /* Coerce to a uintptr_t first to avoid potential gcc warning
3756 about coercing an 8 byte integer to a 4 byte pointer. */
3757 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
,
3758 (PTRACE_ARG4_TYPE
) *(PTRACE_XFER_TYPE
*) (buf
+ i
));
3761 /* At this point, ESRCH should mean the process is
3762 already gone, in which case we simply ignore attempts
3763 to change its registers. See also the related
3764 comment in linux_resume_one_lwp. */
3768 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
3769 error ("writing register %d: %s", regno
, strerror (errno
));
3771 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
3775 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
3776 usr_store_inferior_registers (regcache
, regno
);
3778 #endif /* HAVE_LINUX_USRREGS */
3782 #ifdef HAVE_LINUX_REGSETS
3785 regsets_fetch_inferior_registers (struct regcache
*regcache
)
3787 struct regset_info
*regset
;
3788 int saw_general_regs
= 0;
3792 regset
= target_regsets
;
3794 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3795 while (regset
->size
>= 0)
3800 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
3806 buf
= xmalloc (regset
->size
);
3808 nt_type
= regset
->nt_type
;
3812 iov
.iov_len
= regset
->size
;
3813 data
= (void *) &iov
;
3819 res
= ptrace (regset
->get_request
, pid
, nt_type
, data
);
3821 res
= ptrace (regset
->get_request
, pid
, data
, nt_type
);
3827 /* If we get EIO on a regset, do not try it again for
3829 disabled_regsets
[regset
- target_regsets
] = 1;
3836 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%d",
3841 else if (regset
->type
== GENERAL_REGS
)
3842 saw_general_regs
= 1;
3843 regset
->store_function (regcache
, buf
);
3847 if (saw_general_regs
)
3854 regsets_store_inferior_registers (struct regcache
*regcache
)
3856 struct regset_info
*regset
;
3857 int saw_general_regs
= 0;
3861 regset
= target_regsets
;
3863 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3864 while (regset
->size
>= 0)
3869 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
3875 buf
= xmalloc (regset
->size
);
3877 /* First fill the buffer with the current register set contents,
3878 in case there are any items in the kernel's regset that are
3879 not in gdbserver's regcache. */
3881 nt_type
= regset
->nt_type
;
3885 iov
.iov_len
= regset
->size
;
3886 data
= (void *) &iov
;
3892 res
= ptrace (regset
->get_request
, pid
, nt_type
, data
);
3894 res
= ptrace (regset
->get_request
, pid
, &iov
, data
);
3899 /* Then overlay our cached registers on that. */
3900 regset
->fill_function (regcache
, buf
);
3902 /* Only now do we write the register set. */
3904 res
= ptrace (regset
->set_request
, pid
, nt_type
, data
);
3906 res
= ptrace (regset
->set_request
, pid
, data
, nt_type
);
3914 /* If we get EIO on a regset, do not try it again for
3916 disabled_regsets
[regset
- target_regsets
] = 1;
3920 else if (errno
== ESRCH
)
3922 /* At this point, ESRCH should mean the process is
3923 already gone, in which case we simply ignore attempts
3924 to change its registers. See also the related
3925 comment in linux_resume_one_lwp. */
3931 perror ("Warning: ptrace(regsets_store_inferior_registers)");
3934 else if (regset
->type
== GENERAL_REGS
)
3935 saw_general_regs
= 1;
3939 if (saw_general_regs
)
3946 #endif /* HAVE_LINUX_REGSETS */
3950 linux_fetch_registers (struct regcache
*regcache
, int regno
)
3952 #ifdef HAVE_LINUX_REGSETS
3953 if (regsets_fetch_inferior_registers (regcache
) == 0)
3956 #ifdef HAVE_LINUX_USRREGS
3957 usr_fetch_inferior_registers (regcache
, regno
);
3962 linux_store_registers (struct regcache
*regcache
, int regno
)
3964 #ifdef HAVE_LINUX_REGSETS
3965 if (regsets_store_inferior_registers (regcache
) == 0)
3968 #ifdef HAVE_LINUX_USRREGS
3969 usr_store_inferior_registers (regcache
, regno
);
3974 /* Copy LEN bytes from inferior's memory starting at MEMADDR
3975 to debugger memory starting at MYADDR. */
3978 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
3981 /* Round starting address down to longword boundary. */
3982 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
3983 /* Round ending address up; get number of longwords that makes. */
3985 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
3986 / sizeof (PTRACE_XFER_TYPE
);
3987 /* Allocate buffer of that many longwords. */
3988 register PTRACE_XFER_TYPE
*buffer
3989 = (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
3992 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3994 /* Try using /proc. Don't bother for one word. */
3995 if (len
>= 3 * sizeof (long))
3997 /* We could keep this file open and cache it - possibly one per
3998 thread. That requires some juggling, but is even faster. */
3999 sprintf (filename
, "/proc/%d/mem", pid
);
4000 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
4004 /* If pread64 is available, use it. It's faster if the kernel
4005 supports it (only one syscall), and it's 64-bit safe even on
4006 32-bit platforms (for instance, SPARC debugging a SPARC64
4009 if (pread64 (fd
, myaddr
, len
, memaddr
) != len
)
4011 if (lseek (fd
, memaddr
, SEEK_SET
) == -1 || read (fd
, myaddr
, len
) != len
)
4023 /* Read all the longwords */
4024 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
4027 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
4028 about coercing an 8 byte integer to a 4 byte pointer. */
4029 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, pid
,
4030 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
4035 /* Copy appropriate bytes out of the buffer. */
4037 (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
4043 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
4044 memory at MEMADDR. On failure (cannot write to the inferior)
4045 returns the value of errno. */
4048 linux_write_memory (CORE_ADDR memaddr
, const unsigned char *myaddr
, int len
)
4051 /* Round starting address down to longword boundary. */
4052 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
4053 /* Round ending address up; get number of longwords that makes. */
4055 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
4056 / sizeof (PTRACE_XFER_TYPE
);
4058 /* Allocate buffer of that many longwords. */
4059 register PTRACE_XFER_TYPE
*buffer
= (PTRACE_XFER_TYPE
*)
4060 alloca (count
* sizeof (PTRACE_XFER_TYPE
));
4062 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
4066 /* Dump up to four bytes. */
4067 unsigned int val
= * (unsigned int *) myaddr
;
4073 val
= val
& 0xffffff;
4074 fprintf (stderr
, "Writing %0*x to 0x%08lx\n", 2 * ((len
< 4) ? len
: 4),
4075 val
, (long)memaddr
);
4078 /* Fill start and end extra bytes of buffer with existing memory data. */
4081 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
4082 about coercing an 8 byte integer to a 4 byte pointer. */
4083 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, pid
,
4084 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
4092 = ptrace (PTRACE_PEEKTEXT
, pid
,
4093 /* Coerce to a uintptr_t first to avoid potential gcc warning
4094 about coercing an 8 byte integer to a 4 byte pointer. */
4095 (PTRACE_ARG3_TYPE
) (uintptr_t) (addr
+ (count
- 1)
4096 * sizeof (PTRACE_XFER_TYPE
)),
4102 /* Copy data to be written over corresponding part of buffer. */
4104 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
4107 /* Write the entire buffer. */
4109 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
4112 ptrace (PTRACE_POKETEXT
, pid
,
4113 /* Coerce to a uintptr_t first to avoid potential gcc warning
4114 about coercing an 8 byte integer to a 4 byte pointer. */
4115 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
,
4116 (PTRACE_ARG4_TYPE
) buffer
[i
]);
4124 /* Non-zero if the kernel supports PTRACE_O_TRACEFORK. */
4125 static int linux_supports_tracefork_flag
;
4128 linux_enable_event_reporting (int pid
)
4130 if (!linux_supports_tracefork_flag
)
4133 ptrace (PTRACE_SETOPTIONS
, pid
, 0, (PTRACE_ARG4_TYPE
) PTRACE_O_TRACECLONE
);
4136 /* Helper functions for linux_test_for_tracefork, called via clone (). */
4139 linux_tracefork_grandchild (void *arg
)
4144 #define STACK_SIZE 4096
4147 linux_tracefork_child (void *arg
)
4149 ptrace (PTRACE_TRACEME
, 0, 0, 0);
4150 kill (getpid (), SIGSTOP
);
4152 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
4155 linux_tracefork_grandchild (NULL
);
4157 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4160 __clone2 (linux_tracefork_grandchild
, arg
, STACK_SIZE
,
4161 CLONE_VM
| SIGCHLD
, NULL
);
4163 clone (linux_tracefork_grandchild
, (char *) arg
+ STACK_SIZE
,
4164 CLONE_VM
| SIGCHLD
, NULL
);
4167 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4172 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
4173 sure that we can enable the option, and that it had the desired
4177 linux_test_for_tracefork (void)
4179 int child_pid
, ret
, status
;
4181 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4182 char *stack
= xmalloc (STACK_SIZE
* 4);
4183 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4185 linux_supports_tracefork_flag
= 0;
4187 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
4189 child_pid
= fork ();
4191 linux_tracefork_child (NULL
);
4193 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4195 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
4197 child_pid
= __clone2 (linux_tracefork_child
, stack
, STACK_SIZE
,
4198 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
4199 #else /* !__ia64__ */
4200 child_pid
= clone (linux_tracefork_child
, stack
+ STACK_SIZE
,
4201 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
4202 #endif /* !__ia64__ */
4204 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4206 if (child_pid
== -1)
4207 perror_with_name ("clone");
4209 ret
= my_waitpid (child_pid
, &status
, 0);
4211 perror_with_name ("waitpid");
4212 else if (ret
!= child_pid
)
4213 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret
);
4214 if (! WIFSTOPPED (status
))
4215 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status
);
4217 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0,
4218 (PTRACE_ARG4_TYPE
) PTRACE_O_TRACEFORK
);
4221 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
4224 warning ("linux_test_for_tracefork: failed to kill child");
4228 ret
= my_waitpid (child_pid
, &status
, 0);
4229 if (ret
!= child_pid
)
4230 warning ("linux_test_for_tracefork: failed to wait for killed child");
4231 else if (!WIFSIGNALED (status
))
4232 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
4233 "killed child", status
);
4238 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
4240 warning ("linux_test_for_tracefork: failed to resume child");
4242 ret
= my_waitpid (child_pid
, &status
, 0);
4244 if (ret
== child_pid
&& WIFSTOPPED (status
)
4245 && status
>> 16 == PTRACE_EVENT_FORK
)
4248 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
4249 if (ret
== 0 && second_pid
!= 0)
4253 linux_supports_tracefork_flag
= 1;
4254 my_waitpid (second_pid
, &second_status
, 0);
4255 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
4257 warning ("linux_test_for_tracefork: failed to kill second child");
4258 my_waitpid (second_pid
, &status
, 0);
4262 warning ("linux_test_for_tracefork: unexpected result from waitpid "
4263 "(%d, status 0x%x)", ret
, status
);
4267 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
4269 warning ("linux_test_for_tracefork: failed to kill child");
4270 my_waitpid (child_pid
, &status
, 0);
4272 while (WIFSTOPPED (status
));
4274 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4276 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4281 linux_look_up_symbols (void)
4283 #ifdef USE_THREAD_DB
4284 struct process_info
*proc
= current_process ();
4286 if (proc
->private->thread_db
!= NULL
)
4289 /* If the kernel supports tracing forks then it also supports tracing
4290 clones, and then we don't need to use the magic thread event breakpoint
4291 to learn about threads. */
4292 thread_db_init (!linux_supports_tracefork_flag
);
4297 linux_request_interrupt (void)
4299 extern unsigned long signal_pid
;
4301 if (!ptid_equal (cont_thread
, null_ptid
)
4302 && !ptid_equal (cont_thread
, minus_one_ptid
))
4304 struct lwp_info
*lwp
;
4307 lwp
= get_thread_lwp (current_inferior
);
4308 lwpid
= lwpid_of (lwp
);
4309 kill_lwp (lwpid
, SIGINT
);
4312 kill_lwp (signal_pid
, SIGINT
);
4315 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
4316 to debugger memory starting at MYADDR. */
4319 linux_read_auxv (CORE_ADDR offset
, unsigned char *myaddr
, unsigned int len
)
4321 char filename
[PATH_MAX
];
4323 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
4325 xsnprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
4327 fd
= open (filename
, O_RDONLY
);
4331 if (offset
!= (CORE_ADDR
) 0
4332 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4335 n
= read (fd
, myaddr
, len
);
4342 /* These breakpoint and watchpoint related wrapper functions simply
4343 pass on the function call if the target has registered a
4344 corresponding function. */
4347 linux_insert_point (char type
, CORE_ADDR addr
, int len
)
4349 if (the_low_target
.insert_point
!= NULL
)
4350 return the_low_target
.insert_point (type
, addr
, len
);
4352 /* Unsupported (see target.h). */
4357 linux_remove_point (char type
, CORE_ADDR addr
, int len
)
4359 if (the_low_target
.remove_point
!= NULL
)
4360 return the_low_target
.remove_point (type
, addr
, len
);
4362 /* Unsupported (see target.h). */
4367 linux_stopped_by_watchpoint (void)
4369 struct lwp_info
*lwp
= get_thread_lwp (current_inferior
);
4371 return lwp
->stopped_by_watchpoint
;
4375 linux_stopped_data_address (void)
4377 struct lwp_info
*lwp
= get_thread_lwp (current_inferior
);
4379 return lwp
->stopped_data_address
;
4382 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4383 #if defined(__mcoldfire__)
4384 /* These should really be defined in the kernel's ptrace.h header. */
4385 #define PT_TEXT_ADDR 49*4
4386 #define PT_DATA_ADDR 50*4
4387 #define PT_TEXT_END_ADDR 51*4
4389 #define PT_TEXT_ADDR 220
4390 #define PT_TEXT_END_ADDR 224
4391 #define PT_DATA_ADDR 228
4394 /* Under uClinux, programs are loaded at non-zero offsets, which we need
4395 to tell gdb about. */
4398 linux_read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
4400 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
4401 unsigned long text
, text_end
, data
;
4402 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
4406 text
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_ADDR
, 0);
4407 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_END_ADDR
, 0);
4408 data
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_DATA_ADDR
, 0);
4412 /* Both text and data offsets produced at compile-time (and so
4413 used by gdb) are relative to the beginning of the program,
4414 with the data segment immediately following the text segment.
4415 However, the actual runtime layout in memory may put the data
4416 somewhere else, so when we send gdb a data base-address, we
4417 use the real data base address and subtract the compile-time
4418 data base-address from it (which is just the length of the
4419 text segment). BSS immediately follows data in both
4422 *data_p
= data
- (text_end
- text
);
4432 compare_ints (const void *xa
, const void *xb
)
4434 int a
= *(const int *)xa
;
4435 int b
= *(const int *)xb
;
4441 unique (int *b
, int *e
)
4450 /* Given PID, iterates over all threads in that process.
4452 Information about each thread, in a format suitable for qXfer:osdata:thread
4453 is printed to BUFFER, if it's not NULL. BUFFER is assumed to be already
4454 initialized, and the caller is responsible for finishing and appending '\0'
4457 The list of cores that threads are running on is assigned to *CORES, if it
4458 is not NULL. If no cores are found, *CORES will be set to NULL. Caller
4459 should free *CORES. */
4462 list_threads (int pid
, struct buffer
*buffer
, char **cores
)
4466 int *core_numbers
= xmalloc (sizeof (int) * allocated
);
4470 struct stat statbuf
;
4472 sprintf (pathname
, "/proc/%d/task", pid
);
4473 if (stat (pathname
, &statbuf
) == 0 && S_ISDIR (statbuf
.st_mode
))
4475 dir
= opendir (pathname
);
4478 free (core_numbers
);
4482 while ((dp
= readdir (dir
)) != NULL
)
4484 unsigned long lwp
= strtoul (dp
->d_name
, NULL
, 10);
4488 unsigned core
= linux_core_of_thread (ptid_build (pid
, lwp
, 0));
4492 char s
[sizeof ("4294967295")];
4493 sprintf (s
, "%u", core
);
4495 if (count
== allocated
)
4498 core_numbers
= realloc (core_numbers
,
4499 sizeof (int) * allocated
);
4501 core_numbers
[count
++] = core
;
4503 buffer_xml_printf (buffer
,
4505 "<column name=\"pid\">%d</column>"
4506 "<column name=\"tid\">%s</column>"
4507 "<column name=\"core\">%s</column>"
4508 "</item>", pid
, dp
->d_name
, s
);
4513 buffer_xml_printf (buffer
,
4515 "<column name=\"pid\">%d</column>"
4516 "<column name=\"tid\">%s</column>"
4517 "</item>", pid
, dp
->d_name
);
4529 struct buffer buffer2
;
4532 qsort (core_numbers
, count
, sizeof (int), compare_ints
);
4534 /* Remove duplicates. */
4536 e
= unique (b
, core_numbers
+ count
);
4538 buffer_init (&buffer2
);
4540 for (b
= core_numbers
; b
!= e
; ++b
)
4542 char number
[sizeof ("4294967295")];
4543 sprintf (number
, "%u", *b
);
4544 buffer_xml_printf (&buffer2
, "%s%s",
4545 (b
== core_numbers
) ? "" : ",", number
);
4547 buffer_grow_str0 (&buffer2
, "");
4549 *cores
= buffer_finish (&buffer2
);
4552 free (core_numbers
);
4556 show_process (int pid
, const char *username
, struct buffer
*buffer
)
4560 char cmd
[MAXPATHLEN
+ 1];
4562 sprintf (pathname
, "/proc/%d/cmdline", pid
);
4564 if ((f
= fopen (pathname
, "r")) != NULL
)
4566 size_t len
= fread (cmd
, 1, sizeof (cmd
) - 1, f
);
4571 for (i
= 0; i
< len
; i
++)
4576 buffer_xml_printf (buffer
,
4578 "<column name=\"pid\">%d</column>"
4579 "<column name=\"user\">%s</column>"
4580 "<column name=\"command\">%s</column>",
4585 /* This only collects core numbers, and does not print threads. */
4586 list_threads (pid
, NULL
, &cores
);
4590 buffer_xml_printf (buffer
,
4591 "<column name=\"cores\">%s</column>", cores
);
4595 buffer_xml_printf (buffer
, "</item>");
4602 linux_qxfer_osdata (const char *annex
,
4603 unsigned char *readbuf
, unsigned const char *writebuf
,
4604 CORE_ADDR offset
, int len
)
4606 /* We make the process list snapshot when the object starts to be
4608 static const char *buf
;
4609 static long len_avail
= -1;
4610 static struct buffer buffer
;
4616 if (strcmp (annex
, "processes") == 0)
4618 else if (strcmp (annex
, "threads") == 0)
4623 if (!readbuf
|| writebuf
)
4628 if (len_avail
!= -1 && len_avail
!= 0)
4629 buffer_free (&buffer
);
4632 buffer_init (&buffer
);
4634 buffer_grow_str (&buffer
, "<osdata type=\"processes\">");
4636 buffer_grow_str (&buffer
, "<osdata type=\"threads\">");
4638 dirp
= opendir ("/proc");
4642 while ((dp
= readdir (dirp
)) != NULL
)
4644 struct stat statbuf
;
4645 char procentry
[sizeof ("/proc/4294967295")];
4647 if (!isdigit (dp
->d_name
[0])
4648 || strlen (dp
->d_name
) > sizeof ("4294967295") - 1)
4651 sprintf (procentry
, "/proc/%s", dp
->d_name
);
4652 if (stat (procentry
, &statbuf
) == 0
4653 && S_ISDIR (statbuf
.st_mode
))
4655 int pid
= (int) strtoul (dp
->d_name
, NULL
, 10);
4659 struct passwd
*entry
= getpwuid (statbuf
.st_uid
);
4660 show_process (pid
, entry
? entry
->pw_name
: "?", &buffer
);
4664 list_threads (pid
, &buffer
, NULL
);
4671 buffer_grow_str0 (&buffer
, "</osdata>\n");
4672 buf
= buffer_finish (&buffer
);
4673 len_avail
= strlen (buf
);
4676 if (offset
>= len_avail
)
4678 /* Done. Get rid of the data. */
4679 buffer_free (&buffer
);
4685 if (len
> len_avail
- offset
)
4686 len
= len_avail
- offset
;
4687 memcpy (readbuf
, buf
+ offset
, len
);
4692 /* Convert a native/host siginfo object, into/from the siginfo in the
4693 layout of the inferiors' architecture. */
4696 siginfo_fixup (struct siginfo
*siginfo
, void *inf_siginfo
, int direction
)
4700 if (the_low_target
.siginfo_fixup
!= NULL
)
4701 done
= the_low_target
.siginfo_fixup (siginfo
, inf_siginfo
, direction
);
4703 /* If there was no callback, or the callback didn't do anything,
4704 then just do a straight memcpy. */
4708 memcpy (siginfo
, inf_siginfo
, sizeof (struct siginfo
));
4710 memcpy (inf_siginfo
, siginfo
, sizeof (struct siginfo
));
4715 linux_xfer_siginfo (const char *annex
, unsigned char *readbuf
,
4716 unsigned const char *writebuf
, CORE_ADDR offset
, int len
)
4719 struct siginfo siginfo
;
4720 char inf_siginfo
[sizeof (struct siginfo
)];
4722 if (current_inferior
== NULL
)
4725 pid
= lwpid_of (get_thread_lwp (current_inferior
));
4728 fprintf (stderr
, "%s siginfo for lwp %d.\n",
4729 readbuf
!= NULL
? "Reading" : "Writing",
4732 if (offset
>= sizeof (siginfo
))
4735 if (ptrace (PTRACE_GETSIGINFO
, pid
, 0, &siginfo
) != 0)
4738 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
4739 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
4740 inferior with a 64-bit GDBSERVER should look the same as debugging it
4741 with a 32-bit GDBSERVER, we need to convert it. */
4742 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
4744 if (offset
+ len
> sizeof (siginfo
))
4745 len
= sizeof (siginfo
) - offset
;
4747 if (readbuf
!= NULL
)
4748 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
4751 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
4753 /* Convert back to ptrace layout before flushing it out. */
4754 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
4756 if (ptrace (PTRACE_SETSIGINFO
, pid
, 0, &siginfo
) != 0)
4763 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4764 so we notice when children change state; as the handler for the
4765 sigsuspend in my_waitpid. */
4768 sigchld_handler (int signo
)
4770 int old_errno
= errno
;
4776 /* fprintf is not async-signal-safe, so call write
4778 if (write (2, "sigchld_handler\n",
4779 sizeof ("sigchld_handler\n") - 1) < 0)
4780 break; /* just ignore */
4784 if (target_is_async_p ())
4785 async_file_mark (); /* trigger a linux_wait */
4791 linux_supports_non_stop (void)
4797 linux_async (int enable
)
4799 int previous
= (linux_event_pipe
[0] != -1);
4802 fprintf (stderr
, "linux_async (%d), previous=%d\n",
4805 if (previous
!= enable
)
4808 sigemptyset (&mask
);
4809 sigaddset (&mask
, SIGCHLD
);
4811 sigprocmask (SIG_BLOCK
, &mask
, NULL
);
4815 if (pipe (linux_event_pipe
) == -1)
4816 fatal ("creating event pipe failed.");
4818 fcntl (linux_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4819 fcntl (linux_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4821 /* Register the event loop handler. */
4822 add_file_handler (linux_event_pipe
[0],
4823 handle_target_event
, NULL
);
4825 /* Always trigger a linux_wait. */
4830 delete_file_handler (linux_event_pipe
[0]);
4832 close (linux_event_pipe
[0]);
4833 close (linux_event_pipe
[1]);
4834 linux_event_pipe
[0] = -1;
4835 linux_event_pipe
[1] = -1;
4838 sigprocmask (SIG_UNBLOCK
, &mask
, NULL
);
4845 linux_start_non_stop (int nonstop
)
4847 /* Register or unregister from event-loop accordingly. */
4848 linux_async (nonstop
);
4853 linux_supports_multi_process (void)
4859 /* Enumerate spufs IDs for process PID. */
4861 spu_enumerate_spu_ids (long pid
, unsigned char *buf
, CORE_ADDR offset
, int len
)
4867 struct dirent
*entry
;
4869 sprintf (path
, "/proc/%ld/fd", pid
);
4870 dir
= opendir (path
);
4875 while ((entry
= readdir (dir
)) != NULL
)
4881 fd
= atoi (entry
->d_name
);
4885 sprintf (path
, "/proc/%ld/fd/%d", pid
, fd
);
4886 if (stat (path
, &st
) != 0)
4888 if (!S_ISDIR (st
.st_mode
))
4891 if (statfs (path
, &stfs
) != 0)
4893 if (stfs
.f_type
!= SPUFS_MAGIC
)
4896 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4898 *(unsigned int *)(buf
+ pos
- offset
) = fd
;
4908 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
4909 object type, using the /proc file system. */
4911 linux_qxfer_spu (const char *annex
, unsigned char *readbuf
,
4912 unsigned const char *writebuf
,
4913 CORE_ADDR offset
, int len
)
4915 long pid
= lwpid_of (get_thread_lwp (current_inferior
));
4920 if (!writebuf
&& !readbuf
)
4928 return spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4931 sprintf (buf
, "/proc/%ld/fd/%s", pid
, annex
);
4932 fd
= open (buf
, writebuf
? O_WRONLY
: O_RDONLY
);
4937 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4944 ret
= write (fd
, writebuf
, (size_t) len
);
4946 ret
= read (fd
, readbuf
, (size_t) len
);
4953 linux_core_of_thread (ptid_t ptid
)
4955 char filename
[sizeof ("/proc//task//stat")
4956 + 2 * 20 /* decimal digits for 2 numbers, max 2^64 bit each */
4959 char *content
= NULL
;
4962 int content_read
= 0;
4966 sprintf (filename
, "/proc/%d/task/%ld/stat",
4967 ptid_get_pid (ptid
), ptid_get_lwp (ptid
));
4968 f
= fopen (filename
, "r");
4975 content
= realloc (content
, content_read
+ 1024);
4976 n
= fread (content
+ content_read
, 1, 1024, f
);
4980 content
[content_read
] = '\0';
4985 p
= strchr (content
, '(');
4989 p
= strchr (p
, ')');
4993 /* If the first field after program name has index 0, then core number is
4994 the field with index 36. There's no constant for that anywhere. */
4996 p
= strtok_r (p
, " ", &ts
);
4997 for (i
= 0; p
!= NULL
&& i
!= 36; ++i
)
4998 p
= strtok_r (NULL
, " ", &ts
);
5000 if (p
== NULL
|| sscanf (p
, "%d", &core
) == 0)
5010 linux_process_qsupported (const char *query
)
5012 if (the_low_target
.process_qsupported
!= NULL
)
5013 the_low_target
.process_qsupported (query
);
5017 linux_supports_tracepoints (void)
5019 if (*the_low_target
.supports_tracepoints
== NULL
)
5022 return (*the_low_target
.supports_tracepoints
) ();
5026 linux_read_pc (struct regcache
*regcache
)
5028 if (the_low_target
.get_pc
== NULL
)
5031 return (*the_low_target
.get_pc
) (regcache
);
5035 linux_write_pc (struct regcache
*regcache
, CORE_ADDR pc
)
5037 gdb_assert (the_low_target
.set_pc
!= NULL
);
5039 (*the_low_target
.set_pc
) (regcache
, pc
);
5043 linux_thread_stopped (struct thread_info
*thread
)
5045 return get_thread_lwp (thread
)->stopped
;
5048 /* This exposes stop-all-threads functionality to other modules. */
5051 linux_pause_all (int freeze
)
5053 stop_all_lwps (freeze
, NULL
);
5056 /* This exposes unstop-all-threads functionality to other gdbserver
5060 linux_unpause_all (int unfreeze
)
5062 unstop_all_lwps (unfreeze
, NULL
);
5066 linux_prepare_to_access_memory (void)
5068 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
5071 linux_pause_all (1);
5076 linux_done_accessing_memory (void)
5078 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
5081 linux_unpause_all (1);
5085 linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint
, CORE_ADDR tpaddr
,
5086 CORE_ADDR collector
,
5089 CORE_ADDR
*jump_entry
,
5090 unsigned char *jjump_pad_insn
,
5091 ULONGEST
*jjump_pad_insn_size
,
5092 CORE_ADDR
*adjusted_insn_addr
,
5093 CORE_ADDR
*adjusted_insn_addr_end
)
5095 return (*the_low_target
.install_fast_tracepoint_jump_pad
)
5096 (tpoint
, tpaddr
, collector
, lockaddr
, orig_size
,
5097 jump_entry
, jjump_pad_insn
, jjump_pad_insn_size
,
5098 adjusted_insn_addr
, adjusted_insn_addr_end
);
5101 static struct emit_ops
*
5102 linux_emit_ops (void)
5104 if (the_low_target
.emit_ops
!= NULL
)
5105 return (*the_low_target
.emit_ops
) ();
5110 static struct target_ops linux_target_ops
= {
5111 linux_create_inferior
,
5120 linux_fetch_registers
,
5121 linux_store_registers
,
5122 linux_prepare_to_access_memory
,
5123 linux_done_accessing_memory
,
5126 linux_look_up_symbols
,
5127 linux_request_interrupt
,
5131 linux_stopped_by_watchpoint
,
5132 linux_stopped_data_address
,
5133 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
5138 #ifdef USE_THREAD_DB
5139 thread_db_get_tls_address
,
5144 hostio_last_error_from_errno
,
5147 linux_supports_non_stop
,
5149 linux_start_non_stop
,
5150 linux_supports_multi_process
,
5151 #ifdef USE_THREAD_DB
5152 thread_db_handle_monitor_command
,
5156 linux_core_of_thread
,
5157 linux_process_qsupported
,
5158 linux_supports_tracepoints
,
5161 linux_thread_stopped
,
5165 linux_cancel_breakpoints
,
5166 linux_stabilize_threads
,
5167 linux_install_fast_tracepoint_jump_pad
,
5172 linux_init_signals ()
5174 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
5175 to find what the cancel signal actually is. */
5176 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
5177 signal (__SIGRTMIN
+1, SIG_IGN
);
5182 initialize_low (void)
5184 struct sigaction sigchld_action
;
5185 memset (&sigchld_action
, 0, sizeof (sigchld_action
));
5186 set_target_ops (&linux_target_ops
);
5187 set_breakpoint_data (the_low_target
.breakpoint
,
5188 the_low_target
.breakpoint_len
);
5189 linux_init_signals ();
5190 linux_test_for_tracefork ();
5191 #ifdef HAVE_LINUX_REGSETS
5192 for (num_regsets
= 0; target_regsets
[num_regsets
].size
>= 0; num_regsets
++)
5194 disabled_regsets
= xmalloc (num_regsets
);
5197 sigchld_action
.sa_handler
= sigchld_handler
;
5198 sigemptyset (&sigchld_action
.sa_mask
);
5199 sigchld_action
.sa_flags
= SA_RESTART
;
5200 sigaction (SIGCHLD
, &sigchld_action
, NULL
);