1 /* Low level interface to ptrace, for the remote server for GDB.
2 Copyright (C) 1995-1996, 1998-2012 Free Software Foundation, Inc.
4 This file is part of GDB.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>. */
20 #include "linux-low.h"
21 #include "linux-osdata.h"
26 #include <sys/param.h>
27 #include <sys/ptrace.h>
28 #include "linux-ptrace.h"
29 #include "linux-procfs.h"
31 #include <sys/ioctl.h>
37 #include <sys/syscall.h>
41 #include <sys/types.h>
47 /* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h
48 then ELFMAG0 will have been defined. If it didn't get included by
49 gdb_proc_service.h then including it will likely introduce a duplicate
50 definition of elf_fpregset_t. */
55 #define SPUFS_MAGIC 0x23c9b64e
58 #ifdef HAVE_PERSONALITY
59 # include <sys/personality.h>
60 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
61 # define ADDR_NO_RANDOMIZE 0x0040000
70 #define W_STOPCODE(sig) ((sig) << 8 | 0x7f)
73 /* This is the kernel's hard limit. Not to be confused with
80 #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
85 /* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
86 representation of the thread ID.
88 ``all_lwps'' is keyed by the process ID - which on Linux is (presently)
89 the same as the LWP ID.
91 ``all_processes'' is keyed by the "overall process ID", which
92 GNU/Linux calls tgid, "thread group ID". */
94 struct inferior_list all_lwps
;
96 /* A list of all unknown processes which receive stop signals. Some
97 other process will presumably claim each of these as forked
98 children momentarily. */
100 struct simple_pid_list
102 /* The process ID. */
105 /* The status as reported by waitpid. */
109 struct simple_pid_list
*next
;
111 struct simple_pid_list
*stopped_pids
;
113 /* Trivial list manipulation functions to keep track of a list of new
114 stopped processes. */
117 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
119 struct simple_pid_list
*new_pid
= xmalloc (sizeof (struct simple_pid_list
));
122 new_pid
->status
= status
;
123 new_pid
->next
= *listp
;
128 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *statusp
)
130 struct simple_pid_list
**p
;
132 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
133 if ((*p
)->pid
== pid
)
135 struct simple_pid_list
*next
= (*p
)->next
;
137 *statusp
= (*p
)->status
;
145 /* FIXME this is a bit of a hack, and could be removed. */
146 int stopping_threads
;
148 /* FIXME make into a target method? */
149 int using_threads
= 1;
151 /* True if we're presently stabilizing threads (moving them out of
153 static int stabilizing_threads
;
155 /* This flag is true iff we've just created or attached to our first
156 inferior but it has not stopped yet. As soon as it does, we need
157 to call the low target's arch_setup callback. Doing this only on
158 the first inferior avoids reinializing the architecture on every
159 inferior, and avoids messing with the register caches of the
160 already running inferiors. NOTE: this assumes all inferiors under
161 control of gdbserver have the same architecture. */
162 static int new_inferior
;
164 static void linux_resume_one_lwp (struct lwp_info
*lwp
,
165 int step
, int signal
, siginfo_t
*info
);
166 static void linux_resume (struct thread_resume
*resume_info
, size_t n
);
167 static void stop_all_lwps (int suspend
, struct lwp_info
*except
);
168 static void unstop_all_lwps (int unsuspend
, struct lwp_info
*except
);
169 static int linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
);
170 static void *add_lwp (ptid_t ptid
);
171 static int linux_stopped_by_watchpoint (void);
172 static void mark_lwp_dead (struct lwp_info
*lwp
, int wstat
);
173 static void proceed_all_lwps (void);
174 static int finish_step_over (struct lwp_info
*lwp
);
175 static CORE_ADDR
get_stop_pc (struct lwp_info
*lwp
);
176 static int kill_lwp (unsigned long lwpid
, int signo
);
177 static void linux_enable_event_reporting (int pid
);
179 /* True if the low target can hardware single-step. Such targets
180 don't need a BREAKPOINT_REINSERT_ADDR callback. */
183 can_hardware_single_step (void)
185 return (the_low_target
.breakpoint_reinsert_addr
== NULL
);
188 /* True if the low target supports memory breakpoints. If so, we'll
189 have a GET_PC implementation. */
192 supports_breakpoints (void)
194 return (the_low_target
.get_pc
!= NULL
);
197 /* Returns true if this target can support fast tracepoints. This
198 does not mean that the in-process agent has been loaded in the
202 supports_fast_tracepoints (void)
204 return the_low_target
.install_fast_tracepoint_jump_pad
!= NULL
;
207 struct pending_signals
211 struct pending_signals
*prev
;
214 #define PTRACE_ARG3_TYPE void *
215 #define PTRACE_ARG4_TYPE void *
216 #define PTRACE_XFER_TYPE long
218 #ifdef HAVE_LINUX_REGSETS
219 static char *disabled_regsets
;
220 static int num_regsets
;
223 /* The read/write ends of the pipe registered as waitable file in the
225 static int linux_event_pipe
[2] = { -1, -1 };
227 /* True if we're currently in async mode. */
228 #define target_is_async_p() (linux_event_pipe[0] != -1)
230 static void send_sigstop (struct lwp_info
*lwp
);
231 static void wait_for_sigstop (struct inferior_list_entry
*entry
);
233 /* Return non-zero if HEADER is a 64-bit ELF file. */
236 elf_64_header_p (const Elf64_Ehdr
*header
)
238 return (header
->e_ident
[EI_MAG0
] == ELFMAG0
239 && header
->e_ident
[EI_MAG1
] == ELFMAG1
240 && header
->e_ident
[EI_MAG2
] == ELFMAG2
241 && header
->e_ident
[EI_MAG3
] == ELFMAG3
242 && header
->e_ident
[EI_CLASS
] == ELFCLASS64
);
245 /* Return non-zero if FILE is a 64-bit ELF file,
246 zero if the file is not a 64-bit ELF file,
247 and -1 if the file is not accessible or doesn't exist. */
250 elf_64_file_p (const char *file
)
255 fd
= open (file
, O_RDONLY
);
259 if (read (fd
, &header
, sizeof (header
)) != sizeof (header
))
266 return elf_64_header_p (&header
);
269 /* Accepts an integer PID; Returns true if the executable PID is
270 running is a 64-bit ELF file.. */
273 linux_pid_exe_is_elf_64_file (int pid
)
275 char file
[MAXPATHLEN
];
277 sprintf (file
, "/proc/%d/exe", pid
);
278 return elf_64_file_p (file
);
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
;
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
, &status
))
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 #ifdef HAVE_PERSONALITY
560 int personality_orig
= 0, personality_set
= 0;
562 struct lwp_info
*new_lwp
;
566 #ifdef HAVE_PERSONALITY
567 if (disable_randomization
)
570 personality_orig
= personality (0xffffffff);
571 if (errno
== 0 && !(personality_orig
& ADDR_NO_RANDOMIZE
))
574 personality (personality_orig
| ADDR_NO_RANDOMIZE
);
576 if (errno
!= 0 || (personality_set
577 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE
)))
578 warning ("Error disabling address space randomization: %s",
583 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
589 perror_with_name ("fork");
593 ptrace (PTRACE_TRACEME
, 0, 0, 0);
595 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
596 signal (__SIGRTMIN
+ 1, SIG_DFL
);
601 /* If gdbserver is connected to gdb via stdio, redirect the inferior's
602 stdout to stderr so that inferior i/o doesn't corrupt the connection.
603 Also, redirect stdin to /dev/null. */
604 if (remote_connection_is_stdio ())
607 open ("/dev/null", O_RDONLY
);
609 if (write (2, "stdin/stdout redirected\n",
610 sizeof ("stdin/stdout redirected\n") - 1) < 0)
611 /* Errors ignored. */;
614 execv (program
, allargs
);
616 execvp (program
, allargs
);
618 fprintf (stderr
, "Cannot exec %s: %s.\n", program
,
624 #ifdef HAVE_PERSONALITY
628 personality (personality_orig
);
630 warning ("Error restoring address space randomization: %s",
635 linux_add_process (pid
, 0);
637 ptid
= ptid_build (pid
, pid
, 0);
638 new_lwp
= add_lwp (ptid
);
639 add_thread (ptid
, new_lwp
);
640 new_lwp
->must_set_ptrace_flags
= 1;
645 /* Attach to an inferior process. */
648 linux_attach_lwp_1 (unsigned long lwpid
, int initial
)
651 struct lwp_info
*new_lwp
;
653 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) != 0)
655 struct buffer buffer
;
659 /* If we fail to attach to an LWP, just warn. */
660 fprintf (stderr
, "Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
661 strerror (errno
), errno
);
666 /* If we fail to attach to a process, report an error. */
667 buffer_init (&buffer
);
668 linux_ptrace_attach_warnings (lwpid
, &buffer
);
669 buffer_grow_str0 (&buffer
, "");
670 error ("%sCannot attach to lwp %ld: %s (%d)", buffer_finish (&buffer
),
671 lwpid
, strerror (errno
), errno
);
675 /* If lwp is the tgid, we handle adding existing threads later.
676 Otherwise we just add lwp without bothering about any other
678 ptid
= ptid_build (lwpid
, lwpid
, 0);
681 /* Note that extracting the pid from the current inferior is
682 safe, since we're always called in the context of the same
683 process as this new thread. */
684 int pid
= pid_of (get_thread_lwp (current_inferior
));
685 ptid
= ptid_build (pid
, lwpid
, 0);
688 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
689 add_thread (ptid
, new_lwp
);
691 /* We need to wait for SIGSTOP before being able to make the next
692 ptrace call on this LWP. */
693 new_lwp
->must_set_ptrace_flags
= 1;
695 if (linux_proc_pid_is_stopped (lwpid
))
699 "Attached to a stopped process\n");
701 /* The process is definitely stopped. It is in a job control
702 stop, unless the kernel predates the TASK_STOPPED /
703 TASK_TRACED distinction, in which case it might be in a
704 ptrace stop. Make sure it is in a ptrace stop; from there we
705 can kill it, signal it, et cetera.
707 First make sure there is a pending SIGSTOP. Since we are
708 already attached, the process can not transition from stopped
709 to running without a PTRACE_CONT; so we know this signal will
710 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
711 probably already in the queue (unless this kernel is old
712 enough to use TASK_STOPPED for ptrace stops); but since
713 SIGSTOP is not an RT signal, it can only be queued once. */
714 kill_lwp (lwpid
, SIGSTOP
);
716 /* Finally, resume the stopped process. This will deliver the
717 SIGSTOP (or a higher priority signal, just like normal
718 PTRACE_ATTACH), which we'll catch later on. */
719 ptrace (PTRACE_CONT
, lwpid
, 0, 0);
722 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
725 There are several cases to consider here:
727 1) gdbserver has already attached to the process and is being notified
728 of a new thread that is being created.
729 In this case we should ignore that SIGSTOP and resume the
730 process. This is handled below by setting stop_expected = 1,
731 and the fact that add_thread sets last_resume_kind ==
734 2) This is the first thread (the process thread), and we're attaching
735 to it via attach_inferior.
736 In this case we want the process thread to stop.
737 This is handled by having linux_attach set last_resume_kind ==
738 resume_stop after we return.
740 If the pid we are attaching to is also the tgid, we attach to and
741 stop all the existing threads. Otherwise, we attach to pid and
742 ignore any other threads in the same group as this pid.
744 3) GDB is connecting to gdbserver and is requesting an enumeration of all
746 In this case we want the thread to stop.
747 FIXME: This case is currently not properly handled.
748 We should wait for the SIGSTOP but don't. Things work apparently
749 because enough time passes between when we ptrace (ATTACH) and when
750 gdb makes the next ptrace call on the thread.
752 On the other hand, if we are currently trying to stop all threads, we
753 should treat the new thread as if we had sent it a SIGSTOP. This works
754 because we are guaranteed that the add_lwp call above added us to the
755 end of the list, and so the new thread has not yet reached
756 wait_for_sigstop (but will). */
757 new_lwp
->stop_expected
= 1;
761 linux_attach_lwp (unsigned long lwpid
)
763 linux_attach_lwp_1 (lwpid
, 0);
766 /* Attach to PID. If PID is the tgid, attach to it and all
770 linux_attach (unsigned long pid
)
772 /* Attach to PID. We will check for other threads
774 linux_attach_lwp_1 (pid
, 1);
775 linux_add_process (pid
, 1);
779 struct thread_info
*thread
;
781 /* Don't ignore the initial SIGSTOP if we just attached to this
782 process. It will be collected by wait shortly. */
783 thread
= find_thread_ptid (ptid_build (pid
, pid
, 0));
784 thread
->last_resume_kind
= resume_stop
;
787 if (linux_proc_get_tgid (pid
) == pid
)
792 sprintf (pathname
, "/proc/%ld/task", pid
);
794 dir
= opendir (pathname
);
798 fprintf (stderr
, "Could not open /proc/%ld/task.\n", pid
);
803 /* At this point we attached to the tgid. Scan the task for
806 int new_threads_found
;
810 while (iterations
< 2)
812 new_threads_found
= 0;
813 /* Add all the other threads. While we go through the
814 threads, new threads may be spawned. Cycle through
815 the list of threads until we have done two iterations without
816 finding new threads. */
817 while ((dp
= readdir (dir
)) != NULL
)
820 lwp
= strtoul (dp
->d_name
, NULL
, 10);
822 /* Is this a new thread? */
824 && find_thread_ptid (ptid_build (pid
, lwp
, 0)) == NULL
)
826 linux_attach_lwp_1 (lwp
, 0);
831 Found and attached to new lwp %ld\n", lwp
);
835 if (!new_threads_found
)
856 second_thread_of_pid_p (struct inferior_list_entry
*entry
, void *args
)
858 struct counter
*counter
= args
;
860 if (ptid_get_pid (entry
->id
) == counter
->pid
)
862 if (++counter
->count
> 1)
870 last_thread_of_process_p (struct thread_info
*thread
)
872 ptid_t ptid
= ((struct inferior_list_entry
*)thread
)->id
;
873 int pid
= ptid_get_pid (ptid
);
874 struct counter counter
= { pid
, 0 };
876 return (find_inferior (&all_threads
,
877 second_thread_of_pid_p
, &counter
) == NULL
);
883 linux_kill_one_lwp (struct lwp_info
*lwp
)
885 int pid
= lwpid_of (lwp
);
887 /* PTRACE_KILL is unreliable. After stepping into a signal handler,
888 there is no signal context, and ptrace(PTRACE_KILL) (or
889 ptrace(PTRACE_CONT, SIGKILL), pretty much the same) acts like
890 ptrace(CONT, pid, 0,0) and just resumes the tracee. A better
891 alternative is to kill with SIGKILL. We only need one SIGKILL
892 per process, not one for each thread. But since we still support
893 linuxthreads, and we also support debugging programs using raw
894 clone without CLONE_THREAD, we send one for each thread. For
895 years, we used PTRACE_KILL only, so we're being a bit paranoid
896 about some old kernels where PTRACE_KILL might work better
897 (dubious if there are any such, but that's why it's paranoia), so
898 we try SIGKILL first, PTRACE_KILL second, and so we're fine
905 "LKL: kill (SIGKILL) %s, 0, 0 (%s)\n",
906 target_pid_to_str (ptid_of (lwp
)),
907 errno
? strerror (errno
) : "OK");
910 ptrace (PTRACE_KILL
, pid
, 0, 0);
913 "LKL: PTRACE_KILL %s, 0, 0 (%s)\n",
914 target_pid_to_str (ptid_of (lwp
)),
915 errno
? strerror (errno
) : "OK");
918 /* Callback for `find_inferior'. Kills an lwp of a given process,
919 except the leader. */
922 kill_one_lwp_callback (struct inferior_list_entry
*entry
, void *args
)
924 struct thread_info
*thread
= (struct thread_info
*) entry
;
925 struct lwp_info
*lwp
= get_thread_lwp (thread
);
927 int pid
= * (int *) args
;
929 if (ptid_get_pid (entry
->id
) != pid
)
932 /* We avoid killing the first thread here, because of a Linux kernel (at
933 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
934 the children get a chance to be reaped, it will remain a zombie
937 if (lwpid_of (lwp
) == pid
)
940 fprintf (stderr
, "lkop: is last of process %s\n",
941 target_pid_to_str (entry
->id
));
947 linux_kill_one_lwp (lwp
);
949 /* Make sure it died. The loop is most likely unnecessary. */
950 pid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
951 } while (pid
> 0 && WIFSTOPPED (wstat
));
959 struct process_info
*process
;
960 struct lwp_info
*lwp
;
964 process
= find_process_pid (pid
);
968 /* If we're killing a running inferior, make sure it is stopped
969 first, as PTRACE_KILL will not work otherwise. */
970 stop_all_lwps (0, NULL
);
972 find_inferior (&all_threads
, kill_one_lwp_callback
, &pid
);
974 /* See the comment in linux_kill_one_lwp. We did not kill the first
975 thread in the list, so do so now. */
976 lwp
= find_lwp_pid (pid_to_ptid (pid
));
981 fprintf (stderr
, "lk_1: cannot find lwp %ld, for pid: %d\n",
982 lwpid_of (lwp
), pid
);
987 fprintf (stderr
, "lk_1: killing lwp %ld, for pid: %d\n",
988 lwpid_of (lwp
), pid
);
992 linux_kill_one_lwp (lwp
);
994 /* Make sure it died. The loop is most likely unnecessary. */
995 lwpid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
996 } while (lwpid
> 0 && WIFSTOPPED (wstat
));
999 the_target
->mourn (process
);
1001 /* Since we presently can only stop all lwps of all processes, we
1002 need to unstop lwps of other processes. */
1003 unstop_all_lwps (0, NULL
);
1007 /* Get pending signal of THREAD, for detaching purposes. This is the
1008 signal the thread last stopped for, which we need to deliver to the
1009 thread when detaching, otherwise, it'd be suppressed/lost. */
1012 get_detach_signal (struct thread_info
*thread
)
1014 enum target_signal signo
= TARGET_SIGNAL_0
;
1016 struct lwp_info
*lp
= get_thread_lwp (thread
);
1018 if (lp
->status_pending_p
)
1019 status
= lp
->status_pending
;
1022 /* If the thread had been suspended by gdbserver, and it stopped
1023 cleanly, then it'll have stopped with SIGSTOP. But we don't
1024 want to deliver that SIGSTOP. */
1025 if (thread
->last_status
.kind
!= TARGET_WAITKIND_STOPPED
1026 || thread
->last_status
.value
.sig
== TARGET_SIGNAL_0
)
1029 /* Otherwise, we may need to deliver the signal we
1031 status
= lp
->last_status
;
1034 if (!WIFSTOPPED (status
))
1038 "GPS: lwp %s hasn't stopped: no pending signal\n",
1039 target_pid_to_str (ptid_of (lp
)));
1043 /* Extended wait statuses aren't real SIGTRAPs. */
1044 if (WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 != 0)
1048 "GPS: lwp %s had stopped with extended "
1049 "status: no pending signal\n",
1050 target_pid_to_str (ptid_of (lp
)));
1054 signo
= target_signal_from_host (WSTOPSIG (status
));
1056 if (program_signals_p
&& !program_signals
[signo
])
1060 "GPS: lwp %s had signal %s, but it is in nopass state\n",
1061 target_pid_to_str (ptid_of (lp
)),
1062 target_signal_to_string (signo
));
1065 else if (!program_signals_p
1066 /* If we have no way to know which signals GDB does not
1067 want to have passed to the program, assume
1068 SIGTRAP/SIGINT, which is GDB's default. */
1069 && (signo
== TARGET_SIGNAL_TRAP
|| signo
== TARGET_SIGNAL_INT
))
1073 "GPS: lwp %s had signal %s, "
1074 "but we don't know if we should pass it. Default to not.\n",
1075 target_pid_to_str (ptid_of (lp
)),
1076 target_signal_to_string (signo
));
1083 "GPS: lwp %s has pending signal %s: delivering it.\n",
1084 target_pid_to_str (ptid_of (lp
)),
1085 target_signal_to_string (signo
));
1087 return WSTOPSIG (status
);
1092 linux_detach_one_lwp (struct inferior_list_entry
*entry
, void *args
)
1094 struct thread_info
*thread
= (struct thread_info
*) entry
;
1095 struct lwp_info
*lwp
= get_thread_lwp (thread
);
1096 int pid
= * (int *) args
;
1099 if (ptid_get_pid (entry
->id
) != pid
)
1102 /* If there is a pending SIGSTOP, get rid of it. */
1103 if (lwp
->stop_expected
)
1107 "Sending SIGCONT to %s\n",
1108 target_pid_to_str (ptid_of (lwp
)));
1110 kill_lwp (lwpid_of (lwp
), SIGCONT
);
1111 lwp
->stop_expected
= 0;
1114 /* Flush any pending changes to the process's registers. */
1115 regcache_invalidate_one ((struct inferior_list_entry
*)
1116 get_lwp_thread (lwp
));
1118 /* Pass on any pending signal for this thread. */
1119 sig
= get_detach_signal (thread
);
1121 /* Finally, let it resume. */
1122 if (the_low_target
.prepare_to_resume
!= NULL
)
1123 the_low_target
.prepare_to_resume (lwp
);
1124 if (ptrace (PTRACE_DETACH
, lwpid_of (lwp
), 0, sig
) < 0)
1125 error (_("Can't detach %s: %s"),
1126 target_pid_to_str (ptid_of (lwp
)),
1134 linux_detach (int pid
)
1136 struct process_info
*process
;
1138 process
= find_process_pid (pid
);
1139 if (process
== NULL
)
1142 /* Stop all threads before detaching. First, ptrace requires that
1143 the thread is stopped to sucessfully detach. Second, thread_db
1144 may need to uninstall thread event breakpoints from memory, which
1145 only works with a stopped process anyway. */
1146 stop_all_lwps (0, NULL
);
1148 #ifdef USE_THREAD_DB
1149 thread_db_detach (process
);
1152 /* Stabilize threads (move out of jump pads). */
1153 stabilize_threads ();
1155 find_inferior (&all_threads
, linux_detach_one_lwp
, &pid
);
1157 the_target
->mourn (process
);
1159 /* Since we presently can only stop all lwps of all processes, we
1160 need to unstop lwps of other processes. */
1161 unstop_all_lwps (0, NULL
);
1165 /* Remove all LWPs that belong to process PROC from the lwp list. */
1168 delete_lwp_callback (struct inferior_list_entry
*entry
, void *proc
)
1170 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1171 struct process_info
*process
= proc
;
1173 if (pid_of (lwp
) == pid_of (process
))
1180 linux_mourn (struct process_info
*process
)
1182 struct process_info_private
*priv
;
1184 #ifdef USE_THREAD_DB
1185 thread_db_mourn (process
);
1188 find_inferior (&all_lwps
, delete_lwp_callback
, process
);
1190 /* Freeing all private data. */
1191 priv
= process
->private;
1192 free (priv
->arch_private
);
1194 process
->private = NULL
;
1196 remove_process (process
);
1200 linux_join (int pid
)
1205 ret
= my_waitpid (pid
, &status
, 0);
1206 if (WIFEXITED (status
) || WIFSIGNALED (status
))
1208 } while (ret
!= -1 || errno
!= ECHILD
);
1211 /* Return nonzero if the given thread is still alive. */
1213 linux_thread_alive (ptid_t ptid
)
1215 struct lwp_info
*lwp
= find_lwp_pid (ptid
);
1217 /* We assume we always know if a thread exits. If a whole process
1218 exited but we still haven't been able to report it to GDB, we'll
1219 hold on to the last lwp of the dead process. */
1226 /* Return 1 if this lwp has an interesting status pending. */
1228 status_pending_p_callback (struct inferior_list_entry
*entry
, void *arg
)
1230 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1231 ptid_t ptid
= * (ptid_t
*) arg
;
1232 struct thread_info
*thread
;
1234 /* Check if we're only interested in events from a specific process
1236 if (!ptid_equal (minus_one_ptid
, ptid
)
1237 && ptid_get_pid (ptid
) != ptid_get_pid (lwp
->head
.id
))
1240 thread
= get_lwp_thread (lwp
);
1242 /* If we got a `vCont;t', but we haven't reported a stop yet, do
1243 report any status pending the LWP may have. */
1244 if (thread
->last_resume_kind
== resume_stop
1245 && thread
->last_status
.kind
!= TARGET_WAITKIND_IGNORE
)
1248 return lwp
->status_pending_p
;
1252 same_lwp (struct inferior_list_entry
*entry
, void *data
)
1254 ptid_t ptid
= *(ptid_t
*) data
;
1257 if (ptid_get_lwp (ptid
) != 0)
1258 lwp
= ptid_get_lwp (ptid
);
1260 lwp
= ptid_get_pid (ptid
);
1262 if (ptid_get_lwp (entry
->id
) == lwp
)
1269 find_lwp_pid (ptid_t ptid
)
1271 return (struct lwp_info
*) find_inferior (&all_lwps
, same_lwp
, &ptid
);
1274 static struct lwp_info
*
1275 linux_wait_for_lwp (ptid_t ptid
, int *wstatp
, int options
)
1278 int to_wait_for
= -1;
1279 struct lwp_info
*child
= NULL
;
1282 fprintf (stderr
, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid
));
1284 if (ptid_equal (ptid
, minus_one_ptid
))
1285 to_wait_for
= -1; /* any child */
1287 to_wait_for
= ptid_get_lwp (ptid
); /* this lwp only */
1293 ret
= my_waitpid (to_wait_for
, wstatp
, options
);
1294 if (ret
== 0 || (ret
== -1 && errno
== ECHILD
&& (options
& WNOHANG
)))
1297 perror_with_name ("waitpid");
1300 && (!WIFSTOPPED (*wstatp
)
1301 || (WSTOPSIG (*wstatp
) != 32
1302 && WSTOPSIG (*wstatp
) != 33)))
1303 fprintf (stderr
, "Got an event from %d (%x)\n", ret
, *wstatp
);
1305 child
= find_lwp_pid (pid_to_ptid (ret
));
1307 /* If we didn't find a process, one of two things presumably happened:
1308 - A process we started and then detached from has exited. Ignore it.
1309 - A process we are controlling has forked and the new child's stop
1310 was reported to us by the kernel. Save its PID. */
1311 if (child
== NULL
&& WIFSTOPPED (*wstatp
))
1313 add_to_pid_list (&stopped_pids
, ret
, *wstatp
);
1316 else if (child
== NULL
)
1321 child
->last_status
= *wstatp
;
1323 /* Architecture-specific setup after inferior is running.
1324 This needs to happen after we have attached to the inferior
1325 and it is stopped for the first time, but before we access
1326 any inferior registers. */
1329 the_low_target
.arch_setup ();
1330 #ifdef HAVE_LINUX_REGSETS
1331 memset (disabled_regsets
, 0, num_regsets
);
1336 /* Fetch the possibly triggered data watchpoint info and store it in
1339 On some archs, like x86, that use debug registers to set
1340 watchpoints, it's possible that the way to know which watched
1341 address trapped, is to check the register that is used to select
1342 which address to watch. Problem is, between setting the
1343 watchpoint and reading back which data address trapped, the user
1344 may change the set of watchpoints, and, as a consequence, GDB
1345 changes the debug registers in the inferior. To avoid reading
1346 back a stale stopped-data-address when that happens, we cache in
1347 LP the fact that a watchpoint trapped, and the corresponding data
1348 address, as soon as we see CHILD stop with a SIGTRAP. If GDB
1349 changes the debug registers meanwhile, we have the cached data we
1352 if (WIFSTOPPED (*wstatp
) && WSTOPSIG (*wstatp
) == SIGTRAP
)
1354 if (the_low_target
.stopped_by_watchpoint
== NULL
)
1356 child
->stopped_by_watchpoint
= 0;
1360 struct thread_info
*saved_inferior
;
1362 saved_inferior
= current_inferior
;
1363 current_inferior
= get_lwp_thread (child
);
1365 child
->stopped_by_watchpoint
1366 = the_low_target
.stopped_by_watchpoint ();
1368 if (child
->stopped_by_watchpoint
)
1370 if (the_low_target
.stopped_data_address
!= NULL
)
1371 child
->stopped_data_address
1372 = the_low_target
.stopped_data_address ();
1374 child
->stopped_data_address
= 0;
1377 current_inferior
= saved_inferior
;
1381 /* Store the STOP_PC, with adjustment applied. This depends on the
1382 architecture being defined already (so that CHILD has a valid
1383 regcache), and on LAST_STATUS being set (to check for SIGTRAP or
1385 if (WIFSTOPPED (*wstatp
))
1386 child
->stop_pc
= get_stop_pc (child
);
1389 && WIFSTOPPED (*wstatp
)
1390 && the_low_target
.get_pc
!= NULL
)
1392 struct thread_info
*saved_inferior
= current_inferior
;
1393 struct regcache
*regcache
;
1396 current_inferior
= get_lwp_thread (child
);
1397 regcache
= get_thread_regcache (current_inferior
, 1);
1398 pc
= (*the_low_target
.get_pc
) (regcache
);
1399 fprintf (stderr
, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc
);
1400 current_inferior
= saved_inferior
;
1406 /* This function should only be called if the LWP got a SIGTRAP.
1408 Handle any tracepoint steps or hits. Return true if a tracepoint
1409 event was handled, 0 otherwise. */
1412 handle_tracepoints (struct lwp_info
*lwp
)
1414 struct thread_info
*tinfo
= get_lwp_thread (lwp
);
1415 int tpoint_related_event
= 0;
1417 /* If this tracepoint hit causes a tracing stop, we'll immediately
1418 uninsert tracepoints. To do this, we temporarily pause all
1419 threads, unpatch away, and then unpause threads. We need to make
1420 sure the unpausing doesn't resume LWP too. */
1423 /* And we need to be sure that any all-threads-stopping doesn't try
1424 to move threads out of the jump pads, as it could deadlock the
1425 inferior (LWP could be in the jump pad, maybe even holding the
1428 /* Do any necessary step collect actions. */
1429 tpoint_related_event
|= tracepoint_finished_step (tinfo
, lwp
->stop_pc
);
1431 tpoint_related_event
|= handle_tracepoint_bkpts (tinfo
, lwp
->stop_pc
);
1433 /* See if we just hit a tracepoint and do its main collect
1435 tpoint_related_event
|= tracepoint_was_hit (tinfo
, lwp
->stop_pc
);
1439 gdb_assert (lwp
->suspended
== 0);
1440 gdb_assert (!stabilizing_threads
|| lwp
->collecting_fast_tracepoint
);
1442 if (tpoint_related_event
)
1445 fprintf (stderr
, "got a tracepoint event\n");
1452 /* Convenience wrapper. Returns true if LWP is presently collecting a
1456 linux_fast_tracepoint_collecting (struct lwp_info
*lwp
,
1457 struct fast_tpoint_collect_status
*status
)
1459 CORE_ADDR thread_area
;
1461 if (the_low_target
.get_thread_area
== NULL
)
1464 /* Get the thread area address. This is used to recognize which
1465 thread is which when tracing with the in-process agent library.
1466 We don't read anything from the address, and treat it as opaque;
1467 it's the address itself that we assume is unique per-thread. */
1468 if ((*the_low_target
.get_thread_area
) (lwpid_of (lwp
), &thread_area
) == -1)
1471 return fast_tracepoint_collecting (thread_area
, lwp
->stop_pc
, status
);
1474 /* The reason we resume in the caller, is because we want to be able
1475 to pass lwp->status_pending as WSTAT, and we need to clear
1476 status_pending_p before resuming, otherwise, linux_resume_one_lwp
1477 refuses to resume. */
1480 maybe_move_out_of_jump_pad (struct lwp_info
*lwp
, int *wstat
)
1482 struct thread_info
*saved_inferior
;
1484 saved_inferior
= current_inferior
;
1485 current_inferior
= get_lwp_thread (lwp
);
1488 || (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) != SIGTRAP
))
1489 && supports_fast_tracepoints ()
1490 && agent_loaded_p ())
1492 struct fast_tpoint_collect_status status
;
1497 Checking whether LWP %ld needs to move out of the jump pad.\n",
1500 r
= linux_fast_tracepoint_collecting (lwp
, &status
);
1503 || (WSTOPSIG (*wstat
) != SIGILL
1504 && WSTOPSIG (*wstat
) != SIGFPE
1505 && WSTOPSIG (*wstat
) != SIGSEGV
1506 && WSTOPSIG (*wstat
) != SIGBUS
))
1508 lwp
->collecting_fast_tracepoint
= r
;
1512 if (r
== 1 && lwp
->exit_jump_pad_bkpt
== NULL
)
1514 /* Haven't executed the original instruction yet.
1515 Set breakpoint there, and wait till it's hit,
1516 then single-step until exiting the jump pad. */
1517 lwp
->exit_jump_pad_bkpt
1518 = set_breakpoint_at (status
.adjusted_insn_addr
, NULL
);
1523 Checking whether LWP %ld needs to move out of the jump pad...it does\n",
1525 current_inferior
= saved_inferior
;
1532 /* If we get a synchronous signal while collecting, *and*
1533 while executing the (relocated) original instruction,
1534 reset the PC to point at the tpoint address, before
1535 reporting to GDB. Otherwise, it's an IPA lib bug: just
1536 report the signal to GDB, and pray for the best. */
1538 lwp
->collecting_fast_tracepoint
= 0;
1541 && (status
.adjusted_insn_addr
<= lwp
->stop_pc
1542 && lwp
->stop_pc
< status
.adjusted_insn_addr_end
))
1545 struct regcache
*regcache
;
1547 /* The si_addr on a few signals references the address
1548 of the faulting instruction. Adjust that as
1550 if ((WSTOPSIG (*wstat
) == SIGILL
1551 || WSTOPSIG (*wstat
) == SIGFPE
1552 || WSTOPSIG (*wstat
) == SIGBUS
1553 || WSTOPSIG (*wstat
) == SIGSEGV
)
1554 && ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &info
) == 0
1555 /* Final check just to make sure we don't clobber
1556 the siginfo of non-kernel-sent signals. */
1557 && (uintptr_t) info
.si_addr
== lwp
->stop_pc
)
1559 info
.si_addr
= (void *) (uintptr_t) status
.tpoint_addr
;
1560 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &info
);
1563 regcache
= get_thread_regcache (get_lwp_thread (lwp
), 1);
1564 (*the_low_target
.set_pc
) (regcache
, status
.tpoint_addr
);
1565 lwp
->stop_pc
= status
.tpoint_addr
;
1567 /* Cancel any fast tracepoint lock this thread was
1569 force_unlock_trace_buffer ();
1572 if (lwp
->exit_jump_pad_bkpt
!= NULL
)
1576 "Cancelling fast exit-jump-pad: removing bkpt. "
1577 "stopping all threads momentarily.\n");
1579 stop_all_lwps (1, lwp
);
1580 cancel_breakpoints ();
1582 delete_breakpoint (lwp
->exit_jump_pad_bkpt
);
1583 lwp
->exit_jump_pad_bkpt
= NULL
;
1585 unstop_all_lwps (1, lwp
);
1587 gdb_assert (lwp
->suspended
>= 0);
1594 Checking whether LWP %ld needs to move out of the jump pad...no\n",
1597 current_inferior
= saved_inferior
;
1601 /* Enqueue one signal in the "signals to report later when out of the
1605 enqueue_one_deferred_signal (struct lwp_info
*lwp
, int *wstat
)
1607 struct pending_signals
*p_sig
;
1611 Deferring signal %d for LWP %ld.\n", WSTOPSIG (*wstat
), lwpid_of (lwp
));
1615 struct pending_signals
*sig
;
1617 for (sig
= lwp
->pending_signals_to_report
;
1621 " Already queued %d\n",
1624 fprintf (stderr
, " (no more currently queued signals)\n");
1627 /* Don't enqueue non-RT signals if they are already in the deferred
1628 queue. (SIGSTOP being the easiest signal to see ending up here
1630 if (WSTOPSIG (*wstat
) < __SIGRTMIN
)
1632 struct pending_signals
*sig
;
1634 for (sig
= lwp
->pending_signals_to_report
;
1638 if (sig
->signal
== WSTOPSIG (*wstat
))
1642 "Not requeuing already queued non-RT signal %d"
1651 p_sig
= xmalloc (sizeof (*p_sig
));
1652 p_sig
->prev
= lwp
->pending_signals_to_report
;
1653 p_sig
->signal
= WSTOPSIG (*wstat
);
1654 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
1655 ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &p_sig
->info
);
1657 lwp
->pending_signals_to_report
= p_sig
;
1660 /* Dequeue one signal from the "signals to report later when out of
1661 the jump pad" list. */
1664 dequeue_one_deferred_signal (struct lwp_info
*lwp
, int *wstat
)
1666 if (lwp
->pending_signals_to_report
!= NULL
)
1668 struct pending_signals
**p_sig
;
1670 p_sig
= &lwp
->pending_signals_to_report
;
1671 while ((*p_sig
)->prev
!= NULL
)
1672 p_sig
= &(*p_sig
)->prev
;
1674 *wstat
= W_STOPCODE ((*p_sig
)->signal
);
1675 if ((*p_sig
)->info
.si_signo
!= 0)
1676 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &(*p_sig
)->info
);
1681 fprintf (stderr
, "Reporting deferred signal %d for LWP %ld.\n",
1682 WSTOPSIG (*wstat
), lwpid_of (lwp
));
1686 struct pending_signals
*sig
;
1688 for (sig
= lwp
->pending_signals_to_report
;
1692 " Still queued %d\n",
1695 fprintf (stderr
, " (no more queued signals)\n");
1704 /* Arrange for a breakpoint to be hit again later. We don't keep the
1705 SIGTRAP status and don't forward the SIGTRAP signal to the LWP. We
1706 will handle the current event, eventually we will resume this LWP,
1707 and this breakpoint will trap again. */
1710 cancel_breakpoint (struct lwp_info
*lwp
)
1712 struct thread_info
*saved_inferior
;
1714 /* There's nothing to do if we don't support breakpoints. */
1715 if (!supports_breakpoints ())
1718 /* breakpoint_at reads from current inferior. */
1719 saved_inferior
= current_inferior
;
1720 current_inferior
= get_lwp_thread (lwp
);
1722 if ((*the_low_target
.breakpoint_at
) (lwp
->stop_pc
))
1726 "CB: Push back breakpoint for %s\n",
1727 target_pid_to_str (ptid_of (lwp
)));
1729 /* Back up the PC if necessary. */
1730 if (the_low_target
.decr_pc_after_break
)
1732 struct regcache
*regcache
1733 = get_thread_regcache (current_inferior
, 1);
1734 (*the_low_target
.set_pc
) (regcache
, lwp
->stop_pc
);
1737 current_inferior
= saved_inferior
;
1744 "CB: No breakpoint found at %s for [%s]\n",
1745 paddress (lwp
->stop_pc
),
1746 target_pid_to_str (ptid_of (lwp
)));
1749 current_inferior
= saved_inferior
;
1753 /* When the event-loop is doing a step-over, this points at the thread
1755 ptid_t step_over_bkpt
;
1757 /* Wait for an event from child PID. If PID is -1, wait for any
1758 child. Store the stop status through the status pointer WSTAT.
1759 OPTIONS is passed to the waitpid call. Return 0 if no child stop
1760 event was found and OPTIONS contains WNOHANG. Return the PID of
1761 the stopped child otherwise. */
1764 linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
)
1766 struct lwp_info
*event_child
, *requested_child
;
1770 requested_child
= NULL
;
1772 /* Check for a lwp with a pending status. */
1774 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
1776 event_child
= (struct lwp_info
*)
1777 find_inferior (&all_lwps
, status_pending_p_callback
, &ptid
);
1778 if (debug_threads
&& event_child
)
1779 fprintf (stderr
, "Got a pending child %ld\n", lwpid_of (event_child
));
1783 requested_child
= find_lwp_pid (ptid
);
1785 if (!stopping_threads
1786 && requested_child
->status_pending_p
1787 && requested_child
->collecting_fast_tracepoint
)
1789 enqueue_one_deferred_signal (requested_child
,
1790 &requested_child
->status_pending
);
1791 requested_child
->status_pending_p
= 0;
1792 requested_child
->status_pending
= 0;
1793 linux_resume_one_lwp (requested_child
, 0, 0, NULL
);
1796 if (requested_child
->suspended
1797 && requested_child
->status_pending_p
)
1798 fatal ("requesting an event out of a suspended child?");
1800 if (requested_child
->status_pending_p
)
1801 event_child
= requested_child
;
1804 if (event_child
!= NULL
)
1807 fprintf (stderr
, "Got an event from pending child %ld (%04x)\n",
1808 lwpid_of (event_child
), event_child
->status_pending
);
1809 *wstat
= event_child
->status_pending
;
1810 event_child
->status_pending_p
= 0;
1811 event_child
->status_pending
= 0;
1812 current_inferior
= get_lwp_thread (event_child
);
1813 return lwpid_of (event_child
);
1816 if (ptid_is_pid (ptid
))
1818 /* A request to wait for a specific tgid. This is not possible
1819 with waitpid, so instead, we wait for any child, and leave
1820 children we're not interested in right now with a pending
1821 status to report later. */
1822 wait_ptid
= minus_one_ptid
;
1827 /* We only enter this loop if no process has a pending wait status. Thus
1828 any action taken in response to a wait status inside this loop is
1829 responding as soon as we detect the status, not after any pending
1833 event_child
= linux_wait_for_lwp (wait_ptid
, wstat
, options
);
1835 if ((options
& WNOHANG
) && event_child
== NULL
)
1838 fprintf (stderr
, "WNOHANG set, no event found\n");
1842 if (event_child
== NULL
)
1843 error ("event from unknown child");
1845 if (ptid_is_pid (ptid
)
1846 && ptid_get_pid (ptid
) != ptid_get_pid (ptid_of (event_child
)))
1848 if (! WIFSTOPPED (*wstat
))
1849 mark_lwp_dead (event_child
, *wstat
);
1852 event_child
->status_pending_p
= 1;
1853 event_child
->status_pending
= *wstat
;
1858 current_inferior
= get_lwp_thread (event_child
);
1860 /* Check for thread exit. */
1861 if (! WIFSTOPPED (*wstat
))
1864 fprintf (stderr
, "LWP %ld exiting\n", lwpid_of (event_child
));
1866 /* If the last thread is exiting, just return. */
1867 if (last_thread_of_process_p (current_inferior
))
1870 fprintf (stderr
, "LWP %ld is last lwp of process\n",
1871 lwpid_of (event_child
));
1872 return lwpid_of (event_child
);
1877 current_inferior
= (struct thread_info
*) all_threads
.head
;
1879 fprintf (stderr
, "Current inferior is now %ld\n",
1880 lwpid_of (get_thread_lwp (current_inferior
)));
1884 current_inferior
= NULL
;
1886 fprintf (stderr
, "Current inferior is now <NULL>\n");
1889 /* If we were waiting for this particular child to do something...
1890 well, it did something. */
1891 if (requested_child
!= NULL
)
1893 int lwpid
= lwpid_of (event_child
);
1895 /* Cancel the step-over operation --- the thread that
1896 started it is gone. */
1897 if (finish_step_over (event_child
))
1898 unstop_all_lwps (1, event_child
);
1899 delete_lwp (event_child
);
1903 delete_lwp (event_child
);
1905 /* Wait for a more interesting event. */
1909 if (event_child
->must_set_ptrace_flags
)
1911 linux_enable_event_reporting (lwpid_of (event_child
));
1912 event_child
->must_set_ptrace_flags
= 0;
1915 if (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) == SIGTRAP
1916 && *wstat
>> 16 != 0)
1918 handle_extended_wait (event_child
, *wstat
);
1922 if (WIFSTOPPED (*wstat
)
1923 && WSTOPSIG (*wstat
) == SIGSTOP
1924 && event_child
->stop_expected
)
1929 fprintf (stderr
, "Expected stop.\n");
1930 event_child
->stop_expected
= 0;
1932 should_stop
= (current_inferior
->last_resume_kind
== resume_stop
1933 || stopping_threads
);
1937 linux_resume_one_lwp (event_child
,
1938 event_child
->stepping
, 0, NULL
);
1943 return lwpid_of (event_child
);
1950 /* Count the LWP's that have had events. */
1953 count_events_callback (struct inferior_list_entry
*entry
, void *data
)
1955 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1956 struct thread_info
*thread
= get_lwp_thread (lp
);
1959 gdb_assert (count
!= NULL
);
1961 /* Count only resumed LWPs that have a SIGTRAP event pending that
1962 should be reported to GDB. */
1963 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1964 && thread
->last_resume_kind
!= resume_stop
1965 && lp
->status_pending_p
1966 && WIFSTOPPED (lp
->status_pending
)
1967 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1968 && !breakpoint_inserted_here (lp
->stop_pc
))
1974 /* Select the LWP (if any) that is currently being single-stepped. */
1977 select_singlestep_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
1979 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1980 struct thread_info
*thread
= get_lwp_thread (lp
);
1982 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1983 && thread
->last_resume_kind
== resume_step
1984 && lp
->status_pending_p
)
1990 /* Select the Nth LWP that has had a SIGTRAP event that should be
1994 select_event_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
1996 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1997 struct thread_info
*thread
= get_lwp_thread (lp
);
1998 int *selector
= data
;
2000 gdb_assert (selector
!= NULL
);
2002 /* Select only resumed LWPs that have a SIGTRAP event pending. */
2003 if (thread
->last_resume_kind
!= resume_stop
2004 && thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
2005 && lp
->status_pending_p
2006 && WIFSTOPPED (lp
->status_pending
)
2007 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
2008 && !breakpoint_inserted_here (lp
->stop_pc
))
2009 if ((*selector
)-- == 0)
2016 cancel_breakpoints_callback (struct inferior_list_entry
*entry
, void *data
)
2018 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
2019 struct thread_info
*thread
= get_lwp_thread (lp
);
2020 struct lwp_info
*event_lp
= data
;
2022 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
2026 /* If a LWP other than the LWP that we're reporting an event for has
2027 hit a GDB breakpoint (as opposed to some random trap signal),
2028 then just arrange for it to hit it again later. We don't keep
2029 the SIGTRAP status and don't forward the SIGTRAP signal to the
2030 LWP. We will handle the current event, eventually we will resume
2031 all LWPs, and this one will get its breakpoint trap again.
2033 If we do not do this, then we run the risk that the user will
2034 delete or disable the breakpoint, but the LWP will have already
2037 if (thread
->last_resume_kind
!= resume_stop
2038 && thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
2039 && lp
->status_pending_p
2040 && WIFSTOPPED (lp
->status_pending
)
2041 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
2043 && !lp
->stopped_by_watchpoint
2044 && cancel_breakpoint (lp
))
2045 /* Throw away the SIGTRAP. */
2046 lp
->status_pending_p
= 0;
2052 linux_cancel_breakpoints (void)
2054 find_inferior (&all_lwps
, cancel_breakpoints_callback
, NULL
);
2057 /* Select one LWP out of those that have events pending. */
2060 select_event_lwp (struct lwp_info
**orig_lp
)
2063 int random_selector
;
2064 struct lwp_info
*event_lp
;
2066 /* Give preference to any LWP that is being single-stepped. */
2068 = (struct lwp_info
*) find_inferior (&all_lwps
,
2069 select_singlestep_lwp_callback
, NULL
);
2070 if (event_lp
!= NULL
)
2074 "SEL: Select single-step %s\n",
2075 target_pid_to_str (ptid_of (event_lp
)));
2079 /* No single-stepping LWP. Select one at random, out of those
2080 which have had SIGTRAP events. */
2082 /* First see how many SIGTRAP events we have. */
2083 find_inferior (&all_lwps
, count_events_callback
, &num_events
);
2085 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
2086 random_selector
= (int)
2087 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
2089 if (debug_threads
&& num_events
> 1)
2091 "SEL: Found %d SIGTRAP events, selecting #%d\n",
2092 num_events
, random_selector
);
2094 event_lp
= (struct lwp_info
*) find_inferior (&all_lwps
,
2095 select_event_lwp_callback
,
2099 if (event_lp
!= NULL
)
2101 /* Switch the event LWP. */
2102 *orig_lp
= event_lp
;
2106 /* Decrement the suspend count of an LWP. */
2109 unsuspend_one_lwp (struct inferior_list_entry
*entry
, void *except
)
2111 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2113 /* Ignore EXCEPT. */
2119 gdb_assert (lwp
->suspended
>= 0);
2123 /* Decrement the suspend count of all LWPs, except EXCEPT, if non
2127 unsuspend_all_lwps (struct lwp_info
*except
)
2129 find_inferior (&all_lwps
, unsuspend_one_lwp
, except
);
2132 static void move_out_of_jump_pad_callback (struct inferior_list_entry
*entry
);
2133 static int stuck_in_jump_pad_callback (struct inferior_list_entry
*entry
,
2135 static int lwp_running (struct inferior_list_entry
*entry
, void *data
);
2136 static ptid_t
linux_wait_1 (ptid_t ptid
,
2137 struct target_waitstatus
*ourstatus
,
2138 int target_options
);
2140 /* Stabilize threads (move out of jump pads).
2142 If a thread is midway collecting a fast tracepoint, we need to
2143 finish the collection and move it out of the jump pad before
2144 reporting the signal.
2146 This avoids recursion while collecting (when a signal arrives
2147 midway, and the signal handler itself collects), which would trash
2148 the trace buffer. In case the user set a breakpoint in a signal
2149 handler, this avoids the backtrace showing the jump pad, etc..
2150 Most importantly, there are certain things we can't do safely if
2151 threads are stopped in a jump pad (or in its callee's). For
2154 - starting a new trace run. A thread still collecting the
2155 previous run, could trash the trace buffer when resumed. The trace
2156 buffer control structures would have been reset but the thread had
2157 no way to tell. The thread could even midway memcpy'ing to the
2158 buffer, which would mean that when resumed, it would clobber the
2159 trace buffer that had been set for a new run.
2161 - we can't rewrite/reuse the jump pads for new tracepoints
2162 safely. Say you do tstart while a thread is stopped midway while
2163 collecting. When the thread is later resumed, it finishes the
2164 collection, and returns to the jump pad, to execute the original
2165 instruction that was under the tracepoint jump at the time the
2166 older run had been started. If the jump pad had been rewritten
2167 since for something else in the new run, the thread would now
2168 execute the wrong / random instructions. */
2171 linux_stabilize_threads (void)
2173 struct thread_info
*save_inferior
;
2174 struct lwp_info
*lwp_stuck
;
2177 = (struct lwp_info
*) find_inferior (&all_lwps
,
2178 stuck_in_jump_pad_callback
, NULL
);
2179 if (lwp_stuck
!= NULL
)
2182 fprintf (stderr
, "can't stabilize, LWP %ld is stuck in jump pad\n",
2183 lwpid_of (lwp_stuck
));
2187 save_inferior
= current_inferior
;
2189 stabilizing_threads
= 1;
2192 for_each_inferior (&all_lwps
, move_out_of_jump_pad_callback
);
2194 /* Loop until all are stopped out of the jump pads. */
2195 while (find_inferior (&all_lwps
, lwp_running
, NULL
) != NULL
)
2197 struct target_waitstatus ourstatus
;
2198 struct lwp_info
*lwp
;
2201 /* Note that we go through the full wait even loop. While
2202 moving threads out of jump pad, we need to be able to step
2203 over internal breakpoints and such. */
2204 linux_wait_1 (minus_one_ptid
, &ourstatus
, 0);
2206 if (ourstatus
.kind
== TARGET_WAITKIND_STOPPED
)
2208 lwp
= get_thread_lwp (current_inferior
);
2213 if (ourstatus
.value
.sig
!= TARGET_SIGNAL_0
2214 || current_inferior
->last_resume_kind
== resume_stop
)
2216 wstat
= W_STOPCODE (target_signal_to_host (ourstatus
.value
.sig
));
2217 enqueue_one_deferred_signal (lwp
, &wstat
);
2222 find_inferior (&all_lwps
, unsuspend_one_lwp
, NULL
);
2224 stabilizing_threads
= 0;
2226 current_inferior
= save_inferior
;
2231 = (struct lwp_info
*) find_inferior (&all_lwps
,
2232 stuck_in_jump_pad_callback
, NULL
);
2233 if (lwp_stuck
!= NULL
)
2234 fprintf (stderr
, "couldn't stabilize, LWP %ld got stuck in jump pad\n",
2235 lwpid_of (lwp_stuck
));
2239 /* Wait for process, returns status. */
2242 linux_wait_1 (ptid_t ptid
,
2243 struct target_waitstatus
*ourstatus
, int target_options
)
2246 struct lwp_info
*event_child
;
2249 int step_over_finished
;
2250 int bp_explains_trap
;
2251 int maybe_internal_trap
;
2255 /* Translate generic target options into linux options. */
2257 if (target_options
& TARGET_WNOHANG
)
2261 bp_explains_trap
= 0;
2263 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2265 /* If we were only supposed to resume one thread, only wait for
2266 that thread - if it's still alive. If it died, however - which
2267 can happen if we're coming from the thread death case below -
2268 then we need to make sure we restart the other threads. We could
2269 pick a thread at random or restart all; restarting all is less
2272 && !ptid_equal (cont_thread
, null_ptid
)
2273 && !ptid_equal (cont_thread
, minus_one_ptid
))
2275 struct thread_info
*thread
;
2277 thread
= (struct thread_info
*) find_inferior_id (&all_threads
,
2280 /* No stepping, no signal - unless one is pending already, of course. */
2283 struct thread_resume resume_info
;
2284 resume_info
.thread
= minus_one_ptid
;
2285 resume_info
.kind
= resume_continue
;
2286 resume_info
.sig
= 0;
2287 linux_resume (&resume_info
, 1);
2293 if (ptid_equal (step_over_bkpt
, null_ptid
))
2294 pid
= linux_wait_for_event (ptid
, &w
, options
);
2298 fprintf (stderr
, "step_over_bkpt set [%s], doing a blocking wait\n",
2299 target_pid_to_str (step_over_bkpt
));
2300 pid
= linux_wait_for_event (step_over_bkpt
, &w
, options
& ~WNOHANG
);
2303 if (pid
== 0) /* only if TARGET_WNOHANG */
2306 event_child
= get_thread_lwp (current_inferior
);
2308 /* If we are waiting for a particular child, and it exited,
2309 linux_wait_for_event will return its exit status. Similarly if
2310 the last child exited. If this is not the last child, however,
2311 do not report it as exited until there is a 'thread exited' response
2312 available in the remote protocol. Instead, just wait for another event.
2313 This should be safe, because if the thread crashed we will already
2314 have reported the termination signal to GDB; that should stop any
2315 in-progress stepping operations, etc.
2317 Report the exit status of the last thread to exit. This matches
2318 LinuxThreads' behavior. */
2320 if (last_thread_of_process_p (current_inferior
))
2322 if (WIFEXITED (w
) || WIFSIGNALED (w
))
2326 ourstatus
->kind
= TARGET_WAITKIND_EXITED
;
2327 ourstatus
->value
.integer
= WEXITSTATUS (w
);
2331 "\nChild exited with retcode = %x \n",
2336 ourstatus
->kind
= TARGET_WAITKIND_SIGNALLED
;
2337 ourstatus
->value
.sig
= target_signal_from_host (WTERMSIG (w
));
2341 "\nChild terminated with signal = %x \n",
2346 return ptid_of (event_child
);
2351 if (!WIFSTOPPED (w
))
2355 /* If this event was not handled before, and is not a SIGTRAP, we
2356 report it. SIGILL and SIGSEGV are also treated as traps in case
2357 a breakpoint is inserted at the current PC. If this target does
2358 not support internal breakpoints at all, we also report the
2359 SIGTRAP without further processing; it's of no concern to us. */
2361 = (supports_breakpoints ()
2362 && (WSTOPSIG (w
) == SIGTRAP
2363 || ((WSTOPSIG (w
) == SIGILL
2364 || WSTOPSIG (w
) == SIGSEGV
)
2365 && (*the_low_target
.breakpoint_at
) (event_child
->stop_pc
))));
2367 if (maybe_internal_trap
)
2369 /* Handle anything that requires bookkeeping before deciding to
2370 report the event or continue waiting. */
2372 /* First check if we can explain the SIGTRAP with an internal
2373 breakpoint, or if we should possibly report the event to GDB.
2374 Do this before anything that may remove or insert a
2376 bp_explains_trap
= breakpoint_inserted_here (event_child
->stop_pc
);
2378 /* We have a SIGTRAP, possibly a step-over dance has just
2379 finished. If so, tweak the state machine accordingly,
2380 reinsert breakpoints and delete any reinsert (software
2381 single-step) breakpoints. */
2382 step_over_finished
= finish_step_over (event_child
);
2384 /* Now invoke the callbacks of any internal breakpoints there. */
2385 check_breakpoints (event_child
->stop_pc
);
2387 /* Handle tracepoint data collecting. This may overflow the
2388 trace buffer, and cause a tracing stop, removing
2390 trace_event
= handle_tracepoints (event_child
);
2392 if (bp_explains_trap
)
2394 /* If we stepped or ran into an internal breakpoint, we've
2395 already handled it. So next time we resume (from this
2396 PC), we should step over it. */
2398 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
2400 if (breakpoint_here (event_child
->stop_pc
))
2401 event_child
->need_step_over
= 1;
2406 /* We have some other signal, possibly a step-over dance was in
2407 progress, and it should be cancelled too. */
2408 step_over_finished
= finish_step_over (event_child
);
2411 /* We have all the data we need. Either report the event to GDB, or
2412 resume threads and keep waiting for more. */
2414 /* If we're collecting a fast tracepoint, finish the collection and
2415 move out of the jump pad before delivering a signal. See
2416 linux_stabilize_threads. */
2419 && WSTOPSIG (w
) != SIGTRAP
2420 && supports_fast_tracepoints ()
2421 && agent_loaded_p ())
2425 "Got signal %d for LWP %ld. Check if we need "
2426 "to defer or adjust it.\n",
2427 WSTOPSIG (w
), lwpid_of (event_child
));
2429 /* Allow debugging the jump pad itself. */
2430 if (current_inferior
->last_resume_kind
!= resume_step
2431 && maybe_move_out_of_jump_pad (event_child
, &w
))
2433 enqueue_one_deferred_signal (event_child
, &w
);
2437 "Signal %d for LWP %ld deferred (in jump pad)\n",
2438 WSTOPSIG (w
), lwpid_of (event_child
));
2440 linux_resume_one_lwp (event_child
, 0, 0, NULL
);
2445 if (event_child
->collecting_fast_tracepoint
)
2449 LWP %ld was trying to move out of the jump pad (%d). \
2450 Check if we're already there.\n",
2451 lwpid_of (event_child
),
2452 event_child
->collecting_fast_tracepoint
);
2456 event_child
->collecting_fast_tracepoint
2457 = linux_fast_tracepoint_collecting (event_child
, NULL
);
2459 if (event_child
->collecting_fast_tracepoint
!= 1)
2461 /* No longer need this breakpoint. */
2462 if (event_child
->exit_jump_pad_bkpt
!= NULL
)
2466 "No longer need exit-jump-pad bkpt; removing it."
2467 "stopping all threads momentarily.\n");
2469 /* Other running threads could hit this breakpoint.
2470 We don't handle moribund locations like GDB does,
2471 instead we always pause all threads when removing
2472 breakpoints, so that any step-over or
2473 decr_pc_after_break adjustment is always taken
2474 care of while the breakpoint is still
2476 stop_all_lwps (1, event_child
);
2477 cancel_breakpoints ();
2479 delete_breakpoint (event_child
->exit_jump_pad_bkpt
);
2480 event_child
->exit_jump_pad_bkpt
= NULL
;
2482 unstop_all_lwps (1, event_child
);
2484 gdb_assert (event_child
->suspended
>= 0);
2488 if (event_child
->collecting_fast_tracepoint
== 0)
2492 "fast tracepoint finished "
2493 "collecting successfully.\n");
2495 /* We may have a deferred signal to report. */
2496 if (dequeue_one_deferred_signal (event_child
, &w
))
2499 fprintf (stderr
, "dequeued one signal.\n");
2504 fprintf (stderr
, "no deferred signals.\n");
2506 if (stabilizing_threads
)
2508 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
2509 ourstatus
->value
.sig
= TARGET_SIGNAL_0
;
2510 return ptid_of (event_child
);
2516 /* Check whether GDB would be interested in this event. */
2518 /* If GDB is not interested in this signal, don't stop other
2519 threads, and don't report it to GDB. Just resume the inferior
2520 right away. We do this for threading-related signals as well as
2521 any that GDB specifically requested we ignore. But never ignore
2522 SIGSTOP if we sent it ourselves, and do not ignore signals when
2523 stepping - they may require special handling to skip the signal
2525 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
2528 && current_inferior
->last_resume_kind
!= resume_step
2530 #if defined (USE_THREAD_DB) && !defined (__ANDROID__)
2531 (current_process ()->private->thread_db
!= NULL
2532 && (WSTOPSIG (w
) == __SIGRTMIN
2533 || WSTOPSIG (w
) == __SIGRTMIN
+ 1))
2536 (pass_signals
[target_signal_from_host (WSTOPSIG (w
))]
2537 && !(WSTOPSIG (w
) == SIGSTOP
2538 && current_inferior
->last_resume_kind
== resume_stop
))))
2540 siginfo_t info
, *info_p
;
2543 fprintf (stderr
, "Ignored signal %d for LWP %ld.\n",
2544 WSTOPSIG (w
), lwpid_of (event_child
));
2546 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (event_child
), 0, &info
) == 0)
2550 linux_resume_one_lwp (event_child
, event_child
->stepping
,
2551 WSTOPSIG (w
), info_p
);
2555 /* If GDB wanted this thread to single step, we always want to
2556 report the SIGTRAP, and let GDB handle it. Watchpoints should
2557 always be reported. So should signals we can't explain. A
2558 SIGTRAP we can't explain could be a GDB breakpoint --- we may or
2559 not support Z0 breakpoints. If we do, we're be able to handle
2560 GDB breakpoints on top of internal breakpoints, by handling the
2561 internal breakpoint and still reporting the event to GDB. If we
2562 don't, we're out of luck, GDB won't see the breakpoint hit. */
2563 report_to_gdb
= (!maybe_internal_trap
2564 || current_inferior
->last_resume_kind
== resume_step
2565 || event_child
->stopped_by_watchpoint
2566 || (!step_over_finished
2567 && !bp_explains_trap
&& !trace_event
)
2568 || (gdb_breakpoint_here (event_child
->stop_pc
)
2569 && gdb_condition_true_at_breakpoint (event_child
->stop_pc
)));
2571 /* We found no reason GDB would want us to stop. We either hit one
2572 of our own breakpoints, or finished an internal step GDB
2573 shouldn't know about. */
2578 if (bp_explains_trap
)
2579 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
2580 if (step_over_finished
)
2581 fprintf (stderr
, "Step-over finished.\n");
2583 fprintf (stderr
, "Tracepoint event.\n");
2586 /* We're not reporting this breakpoint to GDB, so apply the
2587 decr_pc_after_break adjustment to the inferior's regcache
2590 if (the_low_target
.set_pc
!= NULL
)
2592 struct regcache
*regcache
2593 = get_thread_regcache (get_lwp_thread (event_child
), 1);
2594 (*the_low_target
.set_pc
) (regcache
, event_child
->stop_pc
);
2597 /* We may have finished stepping over a breakpoint. If so,
2598 we've stopped and suspended all LWPs momentarily except the
2599 stepping one. This is where we resume them all again. We're
2600 going to keep waiting, so use proceed, which handles stepping
2601 over the next breakpoint. */
2603 fprintf (stderr
, "proceeding all threads.\n");
2605 if (step_over_finished
)
2606 unsuspend_all_lwps (event_child
);
2608 proceed_all_lwps ();
2614 if (current_inferior
->last_resume_kind
== resume_step
)
2615 fprintf (stderr
, "GDB wanted to single-step, reporting event.\n");
2616 if (event_child
->stopped_by_watchpoint
)
2617 fprintf (stderr
, "Stopped by watchpoint.\n");
2618 if (gdb_breakpoint_here (event_child
->stop_pc
))
2619 fprintf (stderr
, "Stopped by GDB breakpoint.\n");
2621 fprintf (stderr
, "Hit a non-gdbserver trap event.\n");
2624 /* Alright, we're going to report a stop. */
2626 if (!non_stop
&& !stabilizing_threads
)
2628 /* In all-stop, stop all threads. */
2629 stop_all_lwps (0, NULL
);
2631 /* If we're not waiting for a specific LWP, choose an event LWP
2632 from among those that have had events. Giving equal priority
2633 to all LWPs that have had events helps prevent
2635 if (ptid_equal (ptid
, minus_one_ptid
))
2637 event_child
->status_pending_p
= 1;
2638 event_child
->status_pending
= w
;
2640 select_event_lwp (&event_child
);
2642 event_child
->status_pending_p
= 0;
2643 w
= event_child
->status_pending
;
2646 /* Now that we've selected our final event LWP, cancel any
2647 breakpoints in other LWPs that have hit a GDB breakpoint.
2648 See the comment in cancel_breakpoints_callback to find out
2650 find_inferior (&all_lwps
, cancel_breakpoints_callback
, event_child
);
2652 /* If we were going a step-over, all other threads but the stepping one
2653 had been paused in start_step_over, with their suspend counts
2654 incremented. We don't want to do a full unstop/unpause, because we're
2655 in all-stop mode (so we want threads stopped), but we still need to
2656 unsuspend the other threads, to decrement their `suspended' count
2658 if (step_over_finished
)
2659 unsuspend_all_lwps (event_child
);
2661 /* Stabilize threads (move out of jump pads). */
2662 stabilize_threads ();
2666 /* If we just finished a step-over, then all threads had been
2667 momentarily paused. In all-stop, that's fine, we want
2668 threads stopped by now anyway. In non-stop, we need to
2669 re-resume threads that GDB wanted to be running. */
2670 if (step_over_finished
)
2671 unstop_all_lwps (1, event_child
);
2674 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
2676 if (current_inferior
->last_resume_kind
== resume_stop
2677 && WSTOPSIG (w
) == SIGSTOP
)
2679 /* A thread that has been requested to stop by GDB with vCont;t,
2680 and it stopped cleanly, so report as SIG0. The use of
2681 SIGSTOP is an implementation detail. */
2682 ourstatus
->value
.sig
= TARGET_SIGNAL_0
;
2684 else if (current_inferior
->last_resume_kind
== resume_stop
2685 && WSTOPSIG (w
) != SIGSTOP
)
2687 /* A thread that has been requested to stop by GDB with vCont;t,
2688 but, it stopped for other reasons. */
2689 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
2693 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
2696 gdb_assert (ptid_equal (step_over_bkpt
, null_ptid
));
2699 fprintf (stderr
, "linux_wait ret = %s, %d, %d\n",
2700 target_pid_to_str (ptid_of (event_child
)),
2702 ourstatus
->value
.sig
);
2704 return ptid_of (event_child
);
2707 /* Get rid of any pending event in the pipe. */
2709 async_file_flush (void)
2715 ret
= read (linux_event_pipe
[0], &buf
, 1);
2716 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
2719 /* Put something in the pipe, so the event loop wakes up. */
2721 async_file_mark (void)
2725 async_file_flush ();
2728 ret
= write (linux_event_pipe
[1], "+", 1);
2729 while (ret
== 0 || (ret
== -1 && errno
== EINTR
));
2731 /* Ignore EAGAIN. If the pipe is full, the event loop will already
2732 be awakened anyway. */
2736 linux_wait (ptid_t ptid
,
2737 struct target_waitstatus
*ourstatus
, int target_options
)
2742 fprintf (stderr
, "linux_wait: [%s]\n", target_pid_to_str (ptid
));
2744 /* Flush the async file first. */
2745 if (target_is_async_p ())
2746 async_file_flush ();
2748 event_ptid
= linux_wait_1 (ptid
, ourstatus
, target_options
);
2750 /* If at least one stop was reported, there may be more. A single
2751 SIGCHLD can signal more than one child stop. */
2752 if (target_is_async_p ()
2753 && (target_options
& TARGET_WNOHANG
) != 0
2754 && !ptid_equal (event_ptid
, null_ptid
))
2760 /* Send a signal to an LWP. */
2763 kill_lwp (unsigned long lwpid
, int signo
)
2765 /* Use tkill, if possible, in case we are using nptl threads. If tkill
2766 fails, then we are not using nptl threads and we should be using kill. */
2770 static int tkill_failed
;
2777 ret
= syscall (__NR_tkill
, lwpid
, signo
);
2778 if (errno
!= ENOSYS
)
2785 return kill (lwpid
, signo
);
2789 linux_stop_lwp (struct lwp_info
*lwp
)
2795 send_sigstop (struct lwp_info
*lwp
)
2799 pid
= lwpid_of (lwp
);
2801 /* If we already have a pending stop signal for this process, don't
2803 if (lwp
->stop_expected
)
2806 fprintf (stderr
, "Have pending sigstop for lwp %d\n", pid
);
2812 fprintf (stderr
, "Sending sigstop to lwp %d\n", pid
);
2814 lwp
->stop_expected
= 1;
2815 kill_lwp (pid
, SIGSTOP
);
2819 send_sigstop_callback (struct inferior_list_entry
*entry
, void *except
)
2821 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2823 /* Ignore EXCEPT. */
2834 /* Increment the suspend count of an LWP, and stop it, if not stopped
2837 suspend_and_send_sigstop_callback (struct inferior_list_entry
*entry
,
2840 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2842 /* Ignore EXCEPT. */
2848 return send_sigstop_callback (entry
, except
);
2852 mark_lwp_dead (struct lwp_info
*lwp
, int wstat
)
2854 /* It's dead, really. */
2857 /* Store the exit status for later. */
2858 lwp
->status_pending_p
= 1;
2859 lwp
->status_pending
= wstat
;
2861 /* Prevent trying to stop it. */
2864 /* No further stops are expected from a dead lwp. */
2865 lwp
->stop_expected
= 0;
2869 wait_for_sigstop (struct inferior_list_entry
*entry
)
2871 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2872 struct thread_info
*saved_inferior
;
2881 fprintf (stderr
, "wait_for_sigstop: LWP %ld already stopped\n",
2886 saved_inferior
= current_inferior
;
2887 if (saved_inferior
!= NULL
)
2888 saved_tid
= ((struct inferior_list_entry
*) saved_inferior
)->id
;
2890 saved_tid
= null_ptid
; /* avoid bogus unused warning */
2892 ptid
= lwp
->head
.id
;
2895 fprintf (stderr
, "wait_for_sigstop: pulling one event\n");
2897 pid
= linux_wait_for_event (ptid
, &wstat
, __WALL
);
2899 /* If we stopped with a non-SIGSTOP signal, save it for later
2900 and record the pending SIGSTOP. If the process exited, just
2902 if (WIFSTOPPED (wstat
))
2905 fprintf (stderr
, "LWP %ld stopped with signal %d\n",
2906 lwpid_of (lwp
), WSTOPSIG (wstat
));
2908 if (WSTOPSIG (wstat
) != SIGSTOP
)
2911 fprintf (stderr
, "LWP %ld stopped with non-sigstop status %06x\n",
2912 lwpid_of (lwp
), wstat
);
2914 lwp
->status_pending_p
= 1;
2915 lwp
->status_pending
= wstat
;
2921 fprintf (stderr
, "Process %d exited while stopping LWPs\n", pid
);
2923 lwp
= find_lwp_pid (pid_to_ptid (pid
));
2926 /* Leave this status pending for the next time we're able to
2927 report it. In the mean time, we'll report this lwp as
2928 dead to GDB, so GDB doesn't try to read registers and
2929 memory from it. This can only happen if this was the
2930 last thread of the process; otherwise, PID is removed
2931 from the thread tables before linux_wait_for_event
2933 mark_lwp_dead (lwp
, wstat
);
2937 if (saved_inferior
== NULL
|| linux_thread_alive (saved_tid
))
2938 current_inferior
= saved_inferior
;
2942 fprintf (stderr
, "Previously current thread died.\n");
2946 /* We can't change the current inferior behind GDB's back,
2947 otherwise, a subsequent command may apply to the wrong
2949 current_inferior
= NULL
;
2953 /* Set a valid thread as current. */
2954 set_desired_inferior (0);
2959 /* Returns true if LWP ENTRY is stopped in a jump pad, and we can't
2960 move it out, because we need to report the stop event to GDB. For
2961 example, if the user puts a breakpoint in the jump pad, it's
2962 because she wants to debug it. */
2965 stuck_in_jump_pad_callback (struct inferior_list_entry
*entry
, void *data
)
2967 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2968 struct thread_info
*thread
= get_lwp_thread (lwp
);
2970 gdb_assert (lwp
->suspended
== 0);
2971 gdb_assert (lwp
->stopped
);
2973 /* Allow debugging the jump pad, gdb_collect, etc.. */
2974 return (supports_fast_tracepoints ()
2975 && agent_loaded_p ()
2976 && (gdb_breakpoint_here (lwp
->stop_pc
)
2977 || lwp
->stopped_by_watchpoint
2978 || thread
->last_resume_kind
== resume_step
)
2979 && linux_fast_tracepoint_collecting (lwp
, NULL
));
2983 move_out_of_jump_pad_callback (struct inferior_list_entry
*entry
)
2985 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2986 struct thread_info
*thread
= get_lwp_thread (lwp
);
2989 gdb_assert (lwp
->suspended
== 0);
2990 gdb_assert (lwp
->stopped
);
2992 wstat
= lwp
->status_pending_p
? &lwp
->status_pending
: NULL
;
2994 /* Allow debugging the jump pad, gdb_collect, etc. */
2995 if (!gdb_breakpoint_here (lwp
->stop_pc
)
2996 && !lwp
->stopped_by_watchpoint
2997 && thread
->last_resume_kind
!= resume_step
2998 && maybe_move_out_of_jump_pad (lwp
, wstat
))
3002 "LWP %ld needs stabilizing (in jump pad)\n",
3007 lwp
->status_pending_p
= 0;
3008 enqueue_one_deferred_signal (lwp
, wstat
);
3012 "Signal %d for LWP %ld deferred "
3014 WSTOPSIG (*wstat
), lwpid_of (lwp
));
3017 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
3024 lwp_running (struct inferior_list_entry
*entry
, void *data
)
3026 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
3035 /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
3036 If SUSPEND, then also increase the suspend count of every LWP,
3040 stop_all_lwps (int suspend
, struct lwp_info
*except
)
3042 stopping_threads
= 1;
3045 find_inferior (&all_lwps
, suspend_and_send_sigstop_callback
, except
);
3047 find_inferior (&all_lwps
, send_sigstop_callback
, except
);
3048 for_each_inferior (&all_lwps
, wait_for_sigstop
);
3049 stopping_threads
= 0;
3052 /* Resume execution of the inferior process.
3053 If STEP is nonzero, single-step it.
3054 If SIGNAL is nonzero, give it that signal. */
3057 linux_resume_one_lwp (struct lwp_info
*lwp
,
3058 int step
, int signal
, siginfo_t
*info
)
3060 struct thread_info
*saved_inferior
;
3061 int fast_tp_collecting
;
3063 if (lwp
->stopped
== 0)
3066 fast_tp_collecting
= lwp
->collecting_fast_tracepoint
;
3068 gdb_assert (!stabilizing_threads
|| fast_tp_collecting
);
3070 /* Cancel actions that rely on GDB not changing the PC (e.g., the
3071 user used the "jump" command, or "set $pc = foo"). */
3072 if (lwp
->stop_pc
!= get_pc (lwp
))
3074 /* Collecting 'while-stepping' actions doesn't make sense
3076 release_while_stepping_state_list (get_lwp_thread (lwp
));
3079 /* If we have pending signals or status, and a new signal, enqueue the
3080 signal. Also enqueue the signal if we are waiting to reinsert a
3081 breakpoint; it will be picked up again below. */
3083 && (lwp
->status_pending_p
3084 || lwp
->pending_signals
!= NULL
3085 || lwp
->bp_reinsert
!= 0
3086 || fast_tp_collecting
))
3088 struct pending_signals
*p_sig
;
3089 p_sig
= xmalloc (sizeof (*p_sig
));
3090 p_sig
->prev
= lwp
->pending_signals
;
3091 p_sig
->signal
= signal
;
3093 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
3095 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
3096 lwp
->pending_signals
= p_sig
;
3099 if (lwp
->status_pending_p
)
3102 fprintf (stderr
, "Not resuming lwp %ld (%s, signal %d, stop %s);"
3103 " has pending status\n",
3104 lwpid_of (lwp
), step
? "step" : "continue", signal
,
3105 lwp
->stop_expected
? "expected" : "not expected");
3109 saved_inferior
= current_inferior
;
3110 current_inferior
= get_lwp_thread (lwp
);
3113 fprintf (stderr
, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
3114 lwpid_of (lwp
), step
? "step" : "continue", signal
,
3115 lwp
->stop_expected
? "expected" : "not expected");
3117 /* This bit needs some thinking about. If we get a signal that
3118 we must report while a single-step reinsert is still pending,
3119 we often end up resuming the thread. It might be better to
3120 (ew) allow a stack of pending events; then we could be sure that
3121 the reinsert happened right away and not lose any signals.
3123 Making this stack would also shrink the window in which breakpoints are
3124 uninserted (see comment in linux_wait_for_lwp) but not enough for
3125 complete correctness, so it won't solve that problem. It may be
3126 worthwhile just to solve this one, however. */
3127 if (lwp
->bp_reinsert
!= 0)
3130 fprintf (stderr
, " pending reinsert at 0x%s\n",
3131 paddress (lwp
->bp_reinsert
));
3133 if (lwp
->bp_reinsert
!= 0 && can_hardware_single_step ())
3135 if (fast_tp_collecting
== 0)
3138 fprintf (stderr
, "BAD - reinserting but not stepping.\n");
3140 fprintf (stderr
, "BAD - reinserting and suspended(%d).\n",
3147 /* Postpone any pending signal. It was enqueued above. */
3151 if (fast_tp_collecting
== 1)
3155 lwp %ld wants to get out of fast tracepoint jump pad (exit-jump-pad-bkpt)\n",
3158 /* Postpone any pending signal. It was enqueued above. */
3161 else if (fast_tp_collecting
== 2)
3165 lwp %ld wants to get out of fast tracepoint jump pad single-stepping\n",
3168 if (can_hardware_single_step ())
3171 fatal ("moving out of jump pad single-stepping"
3172 " not implemented on this target");
3174 /* Postpone any pending signal. It was enqueued above. */
3178 /* If we have while-stepping actions in this thread set it stepping.
3179 If we have a signal to deliver, it may or may not be set to
3180 SIG_IGN, we don't know. Assume so, and allow collecting
3181 while-stepping into a signal handler. A possible smart thing to
3182 do would be to set an internal breakpoint at the signal return
3183 address, continue, and carry on catching this while-stepping
3184 action only when that breakpoint is hit. A future
3186 if (get_lwp_thread (lwp
)->while_stepping
!= NULL
3187 && can_hardware_single_step ())
3191 "lwp %ld has a while-stepping action -> forcing step.\n",
3196 if (debug_threads
&& the_low_target
.get_pc
!= NULL
)
3198 struct regcache
*regcache
= get_thread_regcache (current_inferior
, 1);
3199 CORE_ADDR pc
= (*the_low_target
.get_pc
) (regcache
);
3200 fprintf (stderr
, " resuming from pc 0x%lx\n", (long) pc
);
3203 /* If we have pending signals, consume one unless we are trying to
3204 reinsert a breakpoint or we're trying to finish a fast tracepoint
3206 if (lwp
->pending_signals
!= NULL
3207 && lwp
->bp_reinsert
== 0
3208 && fast_tp_collecting
== 0)
3210 struct pending_signals
**p_sig
;
3212 p_sig
= &lwp
->pending_signals
;
3213 while ((*p_sig
)->prev
!= NULL
)
3214 p_sig
= &(*p_sig
)->prev
;
3216 signal
= (*p_sig
)->signal
;
3217 if ((*p_sig
)->info
.si_signo
!= 0)
3218 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &(*p_sig
)->info
);
3224 if (the_low_target
.prepare_to_resume
!= NULL
)
3225 the_low_target
.prepare_to_resume (lwp
);
3227 regcache_invalidate_one ((struct inferior_list_entry
*)
3228 get_lwp_thread (lwp
));
3231 lwp
->stopped_by_watchpoint
= 0;
3232 lwp
->stepping
= step
;
3233 ptrace (step
? PTRACE_SINGLESTEP
: PTRACE_CONT
, lwpid_of (lwp
), 0,
3234 /* Coerce to a uintptr_t first to avoid potential gcc warning
3235 of coercing an 8 byte integer to a 4 byte pointer. */
3236 (PTRACE_ARG4_TYPE
) (uintptr_t) signal
);
3238 current_inferior
= saved_inferior
;
3241 /* ESRCH from ptrace either means that the thread was already
3242 running (an error) or that it is gone (a race condition). If
3243 it's gone, we will get a notification the next time we wait,
3244 so we can ignore the error. We could differentiate these
3245 two, but it's tricky without waiting; the thread still exists
3246 as a zombie, so sending it signal 0 would succeed. So just
3251 perror_with_name ("ptrace");
3255 struct thread_resume_array
3257 struct thread_resume
*resume
;
3261 /* This function is called once per thread. We look up the thread
3262 in RESUME_PTR, and mark the thread with a pointer to the appropriate
3265 This algorithm is O(threads * resume elements), but resume elements
3266 is small (and will remain small at least until GDB supports thread
3269 linux_set_resume_request (struct inferior_list_entry
*entry
, void *arg
)
3271 struct lwp_info
*lwp
;
3272 struct thread_info
*thread
;
3274 struct thread_resume_array
*r
;
3276 thread
= (struct thread_info
*) entry
;
3277 lwp
= get_thread_lwp (thread
);
3280 for (ndx
= 0; ndx
< r
->n
; ndx
++)
3282 ptid_t ptid
= r
->resume
[ndx
].thread
;
3283 if (ptid_equal (ptid
, minus_one_ptid
)
3284 || ptid_equal (ptid
, entry
->id
)
3285 || (ptid_is_pid (ptid
)
3286 && (ptid_get_pid (ptid
) == pid_of (lwp
)))
3287 || (ptid_get_lwp (ptid
) == -1
3288 && (ptid_get_pid (ptid
) == pid_of (lwp
))))
3290 if (r
->resume
[ndx
].kind
== resume_stop
3291 && thread
->last_resume_kind
== resume_stop
)
3294 fprintf (stderr
, "already %s LWP %ld at GDB's request\n",
3295 thread
->last_status
.kind
== TARGET_WAITKIND_STOPPED
3303 lwp
->resume
= &r
->resume
[ndx
];
3304 thread
->last_resume_kind
= lwp
->resume
->kind
;
3306 /* If we had a deferred signal to report, dequeue one now.
3307 This can happen if LWP gets more than one signal while
3308 trying to get out of a jump pad. */
3310 && !lwp
->status_pending_p
3311 && dequeue_one_deferred_signal (lwp
, &lwp
->status_pending
))
3313 lwp
->status_pending_p
= 1;
3317 "Dequeueing deferred signal %d for LWP %ld, "
3318 "leaving status pending.\n",
3319 WSTOPSIG (lwp
->status_pending
), lwpid_of (lwp
));
3326 /* No resume action for this thread. */
3333 /* Set *FLAG_P if this lwp has an interesting status pending. */
3335 resume_status_pending_p (struct inferior_list_entry
*entry
, void *flag_p
)
3337 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
3339 /* LWPs which will not be resumed are not interesting, because
3340 we might not wait for them next time through linux_wait. */
3341 if (lwp
->resume
== NULL
)
3344 if (lwp
->status_pending_p
)
3345 * (int *) flag_p
= 1;
3350 /* Return 1 if this lwp that GDB wants running is stopped at an
3351 internal breakpoint that we need to step over. It assumes that any
3352 required STOP_PC adjustment has already been propagated to the
3353 inferior's regcache. */
3356 need_step_over_p (struct inferior_list_entry
*entry
, void *dummy
)
3358 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
3359 struct thread_info
*thread
;
3360 struct thread_info
*saved_inferior
;
3363 /* LWPs which will not be resumed are not interesting, because we
3364 might not wait for them next time through linux_wait. */
3370 "Need step over [LWP %ld]? Ignoring, not stopped\n",
3375 thread
= get_lwp_thread (lwp
);
3377 if (thread
->last_resume_kind
== resume_stop
)
3381 "Need step over [LWP %ld]? Ignoring, should remain stopped\n",
3386 gdb_assert (lwp
->suspended
>= 0);
3392 "Need step over [LWP %ld]? Ignoring, suspended\n",
3397 if (!lwp
->need_step_over
)
3401 "Need step over [LWP %ld]? No\n", lwpid_of (lwp
));
3404 if (lwp
->status_pending_p
)
3408 "Need step over [LWP %ld]? Ignoring, has pending status.\n",
3413 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
3417 /* If the PC has changed since we stopped, then don't do anything,
3418 and let the breakpoint/tracepoint be hit. This happens if, for
3419 instance, GDB handled the decr_pc_after_break subtraction itself,
3420 GDB is OOL stepping this thread, or the user has issued a "jump"
3421 command, or poked thread's registers herself. */
3422 if (pc
!= lwp
->stop_pc
)
3426 "Need step over [LWP %ld]? Cancelling, PC was changed. "
3427 "Old stop_pc was 0x%s, PC is now 0x%s\n",
3428 lwpid_of (lwp
), paddress (lwp
->stop_pc
), paddress (pc
));
3430 lwp
->need_step_over
= 0;
3434 saved_inferior
= current_inferior
;
3435 current_inferior
= thread
;
3437 /* We can only step over breakpoints we know about. */
3438 if (breakpoint_here (pc
) || fast_tracepoint_jump_here (pc
))
3440 /* Don't step over a breakpoint that GDB expects to hit
3441 though. If the condition is being evaluated on the target's side
3442 and it evaluate to false, step over this breakpoint as well. */
3443 if (gdb_breakpoint_here (pc
)
3444 && gdb_condition_true_at_breakpoint (pc
))
3448 "Need step over [LWP %ld]? yes, but found"
3449 " GDB breakpoint at 0x%s; skipping step over\n",
3450 lwpid_of (lwp
), paddress (pc
));
3452 current_inferior
= saved_inferior
;
3459 "Need step over [LWP %ld]? yes, "
3460 "found breakpoint at 0x%s\n",
3461 lwpid_of (lwp
), paddress (pc
));
3463 /* We've found an lwp that needs stepping over --- return 1 so
3464 that find_inferior stops looking. */
3465 current_inferior
= saved_inferior
;
3467 /* If the step over is cancelled, this is set again. */
3468 lwp
->need_step_over
= 0;
3473 current_inferior
= saved_inferior
;
3477 "Need step over [LWP %ld]? No, no breakpoint found at 0x%s\n",
3478 lwpid_of (lwp
), paddress (pc
));
3483 /* Start a step-over operation on LWP. When LWP stopped at a
3484 breakpoint, to make progress, we need to remove the breakpoint out
3485 of the way. If we let other threads run while we do that, they may
3486 pass by the breakpoint location and miss hitting it. To avoid
3487 that, a step-over momentarily stops all threads while LWP is
3488 single-stepped while the breakpoint is temporarily uninserted from
3489 the inferior. When the single-step finishes, we reinsert the
3490 breakpoint, and let all threads that are supposed to be running,
3493 On targets that don't support hardware single-step, we don't
3494 currently support full software single-stepping. Instead, we only
3495 support stepping over the thread event breakpoint, by asking the
3496 low target where to place a reinsert breakpoint. Since this
3497 routine assumes the breakpoint being stepped over is a thread event
3498 breakpoint, it usually assumes the return address of the current
3499 function is a good enough place to set the reinsert breakpoint. */
3502 start_step_over (struct lwp_info
*lwp
)
3504 struct thread_info
*saved_inferior
;
3510 "Starting step-over on LWP %ld. Stopping all threads\n",
3513 stop_all_lwps (1, lwp
);
3514 gdb_assert (lwp
->suspended
== 0);
3517 fprintf (stderr
, "Done stopping all threads for step-over.\n");
3519 /* Note, we should always reach here with an already adjusted PC,
3520 either by GDB (if we're resuming due to GDB's request), or by our
3521 caller, if we just finished handling an internal breakpoint GDB
3522 shouldn't care about. */
3525 saved_inferior
= current_inferior
;
3526 current_inferior
= get_lwp_thread (lwp
);
3528 lwp
->bp_reinsert
= pc
;
3529 uninsert_breakpoints_at (pc
);
3530 uninsert_fast_tracepoint_jumps_at (pc
);
3532 if (can_hardware_single_step ())
3538 CORE_ADDR raddr
= (*the_low_target
.breakpoint_reinsert_addr
) ();
3539 set_reinsert_breakpoint (raddr
);
3543 current_inferior
= saved_inferior
;
3545 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
3547 /* Require next event from this LWP. */
3548 step_over_bkpt
= lwp
->head
.id
;
3552 /* Finish a step-over. Reinsert the breakpoint we had uninserted in
3553 start_step_over, if still there, and delete any reinsert
3554 breakpoints we've set, on non hardware single-step targets. */
3557 finish_step_over (struct lwp_info
*lwp
)
3559 if (lwp
->bp_reinsert
!= 0)
3562 fprintf (stderr
, "Finished step over.\n");
3564 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
3565 may be no breakpoint to reinsert there by now. */
3566 reinsert_breakpoints_at (lwp
->bp_reinsert
);
3567 reinsert_fast_tracepoint_jumps_at (lwp
->bp_reinsert
);
3569 lwp
->bp_reinsert
= 0;
3571 /* Delete any software-single-step reinsert breakpoints. No
3572 longer needed. We don't have to worry about other threads
3573 hitting this trap, and later not being able to explain it,
3574 because we were stepping over a breakpoint, and we hold all
3575 threads but LWP stopped while doing that. */
3576 if (!can_hardware_single_step ())
3577 delete_reinsert_breakpoints ();
3579 step_over_bkpt
= null_ptid
;
3586 /* This function is called once per thread. We check the thread's resume
3587 request, which will tell us whether to resume, step, or leave the thread
3588 stopped; and what signal, if any, it should be sent.
3590 For threads which we aren't explicitly told otherwise, we preserve
3591 the stepping flag; this is used for stepping over gdbserver-placed
3594 If pending_flags was set in any thread, we queue any needed
3595 signals, since we won't actually resume. We already have a pending
3596 event to report, so we don't need to preserve any step requests;
3597 they should be re-issued if necessary. */
3600 linux_resume_one_thread (struct inferior_list_entry
*entry
, void *arg
)
3602 struct lwp_info
*lwp
;
3603 struct thread_info
*thread
;
3605 int leave_all_stopped
= * (int *) arg
;
3608 thread
= (struct thread_info
*) entry
;
3609 lwp
= get_thread_lwp (thread
);
3611 if (lwp
->resume
== NULL
)
3614 if (lwp
->resume
->kind
== resume_stop
)
3617 fprintf (stderr
, "resume_stop request for LWP %ld\n", lwpid_of (lwp
));
3622 fprintf (stderr
, "stopping LWP %ld\n", lwpid_of (lwp
));
3624 /* Stop the thread, and wait for the event asynchronously,
3625 through the event loop. */
3631 fprintf (stderr
, "already stopped LWP %ld\n",
3634 /* The LWP may have been stopped in an internal event that
3635 was not meant to be notified back to GDB (e.g., gdbserver
3636 breakpoint), so we should be reporting a stop event in
3639 /* If the thread already has a pending SIGSTOP, this is a
3640 no-op. Otherwise, something later will presumably resume
3641 the thread and this will cause it to cancel any pending
3642 operation, due to last_resume_kind == resume_stop. If
3643 the thread already has a pending status to report, we
3644 will still report it the next time we wait - see
3645 status_pending_p_callback. */
3647 /* If we already have a pending signal to report, then
3648 there's no need to queue a SIGSTOP, as this means we're
3649 midway through moving the LWP out of the jumppad, and we
3650 will report the pending signal as soon as that is
3652 if (lwp
->pending_signals_to_report
== NULL
)
3656 /* For stop requests, we're done. */
3658 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
3662 /* If this thread which is about to be resumed has a pending status,
3663 then don't resume any threads - we can just report the pending
3664 status. Make sure to queue any signals that would otherwise be
3665 sent. In all-stop mode, we do this decision based on if *any*
3666 thread has a pending status. If there's a thread that needs the
3667 step-over-breakpoint dance, then don't resume any other thread
3668 but that particular one. */
3669 leave_pending
= (lwp
->status_pending_p
|| leave_all_stopped
);
3674 fprintf (stderr
, "resuming LWP %ld\n", lwpid_of (lwp
));
3676 step
= (lwp
->resume
->kind
== resume_step
);
3677 linux_resume_one_lwp (lwp
, step
, lwp
->resume
->sig
, NULL
);
3682 fprintf (stderr
, "leaving LWP %ld stopped\n", lwpid_of (lwp
));
3684 /* If we have a new signal, enqueue the signal. */
3685 if (lwp
->resume
->sig
!= 0)
3687 struct pending_signals
*p_sig
;
3688 p_sig
= xmalloc (sizeof (*p_sig
));
3689 p_sig
->prev
= lwp
->pending_signals
;
3690 p_sig
->signal
= lwp
->resume
->sig
;
3691 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
3693 /* If this is the same signal we were previously stopped by,
3694 make sure to queue its siginfo. We can ignore the return
3695 value of ptrace; if it fails, we'll skip
3696 PTRACE_SETSIGINFO. */
3697 if (WIFSTOPPED (lwp
->last_status
)
3698 && WSTOPSIG (lwp
->last_status
) == lwp
->resume
->sig
)
3699 ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &p_sig
->info
);
3701 lwp
->pending_signals
= p_sig
;
3705 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
3711 linux_resume (struct thread_resume
*resume_info
, size_t n
)
3713 struct thread_resume_array array
= { resume_info
, n
};
3714 struct lwp_info
*need_step_over
= NULL
;
3716 int leave_all_stopped
;
3718 find_inferior (&all_threads
, linux_set_resume_request
, &array
);
3720 /* If there is a thread which would otherwise be resumed, which has
3721 a pending status, then don't resume any threads - we can just
3722 report the pending status. Make sure to queue any signals that
3723 would otherwise be sent. In non-stop mode, we'll apply this
3724 logic to each thread individually. We consume all pending events
3725 before considering to start a step-over (in all-stop). */
3728 find_inferior (&all_lwps
, resume_status_pending_p
, &any_pending
);
3730 /* If there is a thread which would otherwise be resumed, which is
3731 stopped at a breakpoint that needs stepping over, then don't
3732 resume any threads - have it step over the breakpoint with all
3733 other threads stopped, then resume all threads again. Make sure
3734 to queue any signals that would otherwise be delivered or
3736 if (!any_pending
&& supports_breakpoints ())
3738 = (struct lwp_info
*) find_inferior (&all_lwps
,
3739 need_step_over_p
, NULL
);
3741 leave_all_stopped
= (need_step_over
!= NULL
|| any_pending
);
3745 if (need_step_over
!= NULL
)
3746 fprintf (stderr
, "Not resuming all, need step over\n");
3747 else if (any_pending
)
3749 "Not resuming, all-stop and found "
3750 "an LWP with pending status\n");
3752 fprintf (stderr
, "Resuming, no pending status or step over needed\n");
3755 /* Even if we're leaving threads stopped, queue all signals we'd
3756 otherwise deliver. */
3757 find_inferior (&all_threads
, linux_resume_one_thread
, &leave_all_stopped
);
3760 start_step_over (need_step_over
);
3763 /* This function is called once per thread. We check the thread's
3764 last resume request, which will tell us whether to resume, step, or
3765 leave the thread stopped. Any signal the client requested to be
3766 delivered has already been enqueued at this point.
3768 If any thread that GDB wants running is stopped at an internal
3769 breakpoint that needs stepping over, we start a step-over operation
3770 on that particular thread, and leave all others stopped. */
3773 proceed_one_lwp (struct inferior_list_entry
*entry
, void *except
)
3775 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
3776 struct thread_info
*thread
;
3784 "proceed_one_lwp: lwp %ld\n", lwpid_of (lwp
));
3789 fprintf (stderr
, " LWP %ld already running\n", lwpid_of (lwp
));
3793 thread
= get_lwp_thread (lwp
);
3795 if (thread
->last_resume_kind
== resume_stop
3796 && thread
->last_status
.kind
!= TARGET_WAITKIND_IGNORE
)
3799 fprintf (stderr
, " client wants LWP to remain %ld stopped\n",
3804 if (lwp
->status_pending_p
)
3807 fprintf (stderr
, " LWP %ld has pending status, leaving stopped\n",
3812 gdb_assert (lwp
->suspended
>= 0);
3817 fprintf (stderr
, " LWP %ld is suspended\n", lwpid_of (lwp
));
3821 if (thread
->last_resume_kind
== resume_stop
3822 && lwp
->pending_signals_to_report
== NULL
3823 && lwp
->collecting_fast_tracepoint
== 0)
3825 /* We haven't reported this LWP as stopped yet (otherwise, the
3826 last_status.kind check above would catch it, and we wouldn't
3827 reach here. This LWP may have been momentarily paused by a
3828 stop_all_lwps call while handling for example, another LWP's
3829 step-over. In that case, the pending expected SIGSTOP signal
3830 that was queued at vCont;t handling time will have already
3831 been consumed by wait_for_sigstop, and so we need to requeue
3832 another one here. Note that if the LWP already has a SIGSTOP
3833 pending, this is a no-op. */
3837 "Client wants LWP %ld to stop. "
3838 "Making sure it has a SIGSTOP pending\n",
3844 step
= thread
->last_resume_kind
== resume_step
;
3845 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
3850 unsuspend_and_proceed_one_lwp (struct inferior_list_entry
*entry
, void *except
)
3852 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
3858 gdb_assert (lwp
->suspended
>= 0);
3860 return proceed_one_lwp (entry
, except
);
3863 /* When we finish a step-over, set threads running again. If there's
3864 another thread that may need a step-over, now's the time to start
3865 it. Eventually, we'll move all threads past their breakpoints. */
3868 proceed_all_lwps (void)
3870 struct lwp_info
*need_step_over
;
3872 /* If there is a thread which would otherwise be resumed, which is
3873 stopped at a breakpoint that needs stepping over, then don't
3874 resume any threads - have it step over the breakpoint with all
3875 other threads stopped, then resume all threads again. */
3877 if (supports_breakpoints ())
3880 = (struct lwp_info
*) find_inferior (&all_lwps
,
3881 need_step_over_p
, NULL
);
3883 if (need_step_over
!= NULL
)
3886 fprintf (stderr
, "proceed_all_lwps: found "
3887 "thread %ld needing a step-over\n",
3888 lwpid_of (need_step_over
));
3890 start_step_over (need_step_over
);
3896 fprintf (stderr
, "Proceeding, no step-over needed\n");
3898 find_inferior (&all_lwps
, proceed_one_lwp
, NULL
);
3901 /* Stopped LWPs that the client wanted to be running, that don't have
3902 pending statuses, are set to run again, except for EXCEPT, if not
3903 NULL. This undoes a stop_all_lwps call. */
3906 unstop_all_lwps (int unsuspend
, struct lwp_info
*except
)
3912 "unstopping all lwps, except=(LWP %ld)\n", lwpid_of (except
));
3915 "unstopping all lwps\n");
3919 find_inferior (&all_lwps
, unsuspend_and_proceed_one_lwp
, except
);
3921 find_inferior (&all_lwps
, proceed_one_lwp
, except
);
3925 #ifdef HAVE_LINUX_REGSETS
3927 #define use_linux_regsets 1
3930 regsets_fetch_inferior_registers (struct regcache
*regcache
)
3932 struct regset_info
*regset
;
3933 int saw_general_regs
= 0;
3937 regset
= target_regsets
;
3939 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3940 while (regset
->size
>= 0)
3945 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
3951 buf
= xmalloc (regset
->size
);
3953 nt_type
= regset
->nt_type
;
3957 iov
.iov_len
= regset
->size
;
3958 data
= (void *) &iov
;
3964 res
= ptrace (regset
->get_request
, pid
, nt_type
, data
);
3966 res
= ptrace (regset
->get_request
, pid
, data
, nt_type
);
3972 /* If we get EIO on a regset, do not try it again for
3974 disabled_regsets
[regset
- target_regsets
] = 1;
3981 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%d",
3986 else if (regset
->type
== GENERAL_REGS
)
3987 saw_general_regs
= 1;
3988 regset
->store_function (regcache
, buf
);
3992 if (saw_general_regs
)
3999 regsets_store_inferior_registers (struct regcache
*regcache
)
4001 struct regset_info
*regset
;
4002 int saw_general_regs
= 0;
4006 regset
= target_regsets
;
4008 pid
= lwpid_of (get_thread_lwp (current_inferior
));
4009 while (regset
->size
>= 0)
4014 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
4020 buf
= xmalloc (regset
->size
);
4022 /* First fill the buffer with the current register set contents,
4023 in case there are any items in the kernel's regset that are
4024 not in gdbserver's regcache. */
4026 nt_type
= regset
->nt_type
;
4030 iov
.iov_len
= regset
->size
;
4031 data
= (void *) &iov
;
4037 res
= ptrace (regset
->get_request
, pid
, nt_type
, data
);
4039 res
= ptrace (regset
->get_request
, pid
, &iov
, data
);
4044 /* Then overlay our cached registers on that. */
4045 regset
->fill_function (regcache
, buf
);
4047 /* Only now do we write the register set. */
4049 res
= ptrace (regset
->set_request
, pid
, nt_type
, data
);
4051 res
= ptrace (regset
->set_request
, pid
, data
, nt_type
);
4059 /* If we get EIO on a regset, do not try it again for
4061 disabled_regsets
[regset
- target_regsets
] = 1;
4065 else if (errno
== ESRCH
)
4067 /* At this point, ESRCH should mean the process is
4068 already gone, in which case we simply ignore attempts
4069 to change its registers. See also the related
4070 comment in linux_resume_one_lwp. */
4076 perror ("Warning: ptrace(regsets_store_inferior_registers)");
4079 else if (regset
->type
== GENERAL_REGS
)
4080 saw_general_regs
= 1;
4084 if (saw_general_regs
)
4090 #else /* !HAVE_LINUX_REGSETS */
4092 #define use_linux_regsets 0
4093 #define regsets_fetch_inferior_registers(regcache) 1
4094 #define regsets_store_inferior_registers(regcache) 1
4098 /* Return 1 if register REGNO is supported by one of the regset ptrace
4099 calls or 0 if it has to be transferred individually. */
4102 linux_register_in_regsets (int regno
)
4104 unsigned char mask
= 1 << (regno
% 8);
4105 size_t index
= regno
/ 8;
4107 return (use_linux_regsets
4108 && (the_low_target
.regset_bitmap
== NULL
4109 || (the_low_target
.regset_bitmap
[index
] & mask
) != 0));
4112 #ifdef HAVE_LINUX_USRREGS
4115 register_addr (int regnum
)
4119 if (regnum
< 0 || regnum
>= the_low_target
.num_regs
)
4120 error ("Invalid register number %d.", regnum
);
4122 addr
= the_low_target
.regmap
[regnum
];
4127 /* Fetch one register. */
4129 fetch_register (struct regcache
*regcache
, int regno
)
4136 if (regno
>= the_low_target
.num_regs
)
4138 if ((*the_low_target
.cannot_fetch_register
) (regno
))
4141 regaddr
= register_addr (regno
);
4145 size
= ((register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
4146 & -sizeof (PTRACE_XFER_TYPE
));
4147 buf
= alloca (size
);
4149 pid
= lwpid_of (get_thread_lwp (current_inferior
));
4150 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
4153 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
4154 ptrace (PTRACE_PEEKUSER
, pid
,
4155 /* Coerce to a uintptr_t first to avoid potential gcc warning
4156 of coercing an 8 byte integer to a 4 byte pointer. */
4157 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
, 0);
4158 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
4160 error ("reading register %d: %s", regno
, strerror (errno
));
4163 if (the_low_target
.supply_ptrace_register
)
4164 the_low_target
.supply_ptrace_register (regcache
, regno
, buf
);
4166 supply_register (regcache
, regno
, buf
);
4169 /* Store one register. */
4171 store_register (struct regcache
*regcache
, int regno
)
4178 if (regno
>= the_low_target
.num_regs
)
4180 if ((*the_low_target
.cannot_store_register
) (regno
))
4183 regaddr
= register_addr (regno
);
4187 size
= ((register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
4188 & -sizeof (PTRACE_XFER_TYPE
));
4189 buf
= alloca (size
);
4190 memset (buf
, 0, size
);
4192 if (the_low_target
.collect_ptrace_register
)
4193 the_low_target
.collect_ptrace_register (regcache
, regno
, buf
);
4195 collect_register (regcache
, regno
, buf
);
4197 pid
= lwpid_of (get_thread_lwp (current_inferior
));
4198 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
4201 ptrace (PTRACE_POKEUSER
, pid
,
4202 /* Coerce to a uintptr_t first to avoid potential gcc warning
4203 about coercing an 8 byte integer to a 4 byte pointer. */
4204 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
,
4205 (PTRACE_ARG4_TYPE
) *(PTRACE_XFER_TYPE
*) (buf
+ i
));
4208 /* At this point, ESRCH should mean the process is
4209 already gone, in which case we simply ignore attempts
4210 to change its registers. See also the related
4211 comment in linux_resume_one_lwp. */
4215 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
4216 error ("writing register %d: %s", regno
, strerror (errno
));
4218 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
4222 /* Fetch all registers, or just one, from the child process.
4223 If REGNO is -1, do this for all registers, skipping any that are
4224 assumed to have been retrieved by regsets_fetch_inferior_registers,
4225 unless ALL is non-zero.
4226 Otherwise, REGNO specifies which register (so we can save time). */
4228 usr_fetch_inferior_registers (struct regcache
*regcache
, int regno
, int all
)
4232 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
4233 if (all
|| !linux_register_in_regsets (regno
))
4234 fetch_register (regcache
, regno
);
4237 fetch_register (regcache
, regno
);
4240 /* Store our register values back into the inferior.
4241 If REGNO is -1, do this for all registers, skipping any that are
4242 assumed to have been saved by regsets_store_inferior_registers,
4243 unless ALL is non-zero.
4244 Otherwise, REGNO specifies which register (so we can save time). */
4246 usr_store_inferior_registers (struct regcache
*regcache
, int regno
, int all
)
4250 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
4251 if (all
|| !linux_register_in_regsets (regno
))
4252 store_register (regcache
, regno
);
4255 store_register (regcache
, regno
);
4258 #else /* !HAVE_LINUX_USRREGS */
4260 #define usr_fetch_inferior_registers(regcache, regno, all) do {} while (0)
4261 #define usr_store_inferior_registers(regcache, regno, all) do {} while (0)
4267 linux_fetch_registers (struct regcache
*regcache
, int regno
)
4274 all
= regsets_fetch_inferior_registers (regcache
);
4275 usr_fetch_inferior_registers (regcache
, regno
, all
);
4279 use_regsets
= linux_register_in_regsets (regno
);
4281 all
= regsets_fetch_inferior_registers (regcache
);
4282 if (!use_regsets
|| all
)
4283 usr_fetch_inferior_registers (regcache
, regno
, 1);
4288 linux_store_registers (struct regcache
*regcache
, int regno
)
4295 all
= regsets_store_inferior_registers (regcache
);
4296 usr_store_inferior_registers (regcache
, regno
, all
);
4300 use_regsets
= linux_register_in_regsets (regno
);
4302 all
= regsets_store_inferior_registers (regcache
);
4303 if (!use_regsets
|| all
)
4304 usr_store_inferior_registers (regcache
, regno
, 1);
4309 /* Copy LEN bytes from inferior's memory starting at MEMADDR
4310 to debugger memory starting at MYADDR. */
4313 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
4316 /* Round starting address down to longword boundary. */
4317 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
4318 /* Round ending address up; get number of longwords that makes. */
4320 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
4321 / sizeof (PTRACE_XFER_TYPE
);
4322 /* Allocate buffer of that many longwords. */
4323 register PTRACE_XFER_TYPE
*buffer
4324 = (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
4327 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
4329 /* Try using /proc. Don't bother for one word. */
4330 if (len
>= 3 * sizeof (long))
4332 /* We could keep this file open and cache it - possibly one per
4333 thread. That requires some juggling, but is even faster. */
4334 sprintf (filename
, "/proc/%d/mem", pid
);
4335 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
4339 /* If pread64 is available, use it. It's faster if the kernel
4340 supports it (only one syscall), and it's 64-bit safe even on
4341 32-bit platforms (for instance, SPARC debugging a SPARC64
4344 if (pread64 (fd
, myaddr
, len
, memaddr
) != len
)
4346 if (lseek (fd
, memaddr
, SEEK_SET
) == -1 || read (fd
, myaddr
, len
) != len
)
4358 /* Read all the longwords */
4359 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
4362 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
4363 about coercing an 8 byte integer to a 4 byte pointer. */
4364 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, pid
,
4365 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
4370 /* Copy appropriate bytes out of the buffer. */
4372 (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
4378 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
4379 memory at MEMADDR. On failure (cannot write to the inferior)
4380 returns the value of errno. */
4383 linux_write_memory (CORE_ADDR memaddr
, const unsigned char *myaddr
, int len
)
4386 /* Round starting address down to longword boundary. */
4387 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
4388 /* Round ending address up; get number of longwords that makes. */
4390 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
4391 / sizeof (PTRACE_XFER_TYPE
);
4393 /* Allocate buffer of that many longwords. */
4394 register PTRACE_XFER_TYPE
*buffer
= (PTRACE_XFER_TYPE
*)
4395 alloca (count
* sizeof (PTRACE_XFER_TYPE
));
4397 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
4401 /* Dump up to four bytes. */
4402 unsigned int val
= * (unsigned int *) myaddr
;
4408 val
= val
& 0xffffff;
4409 fprintf (stderr
, "Writing %0*x to 0x%08lx\n", 2 * ((len
< 4) ? len
: 4),
4410 val
, (long)memaddr
);
4413 /* Fill start and end extra bytes of buffer with existing memory data. */
4416 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
4417 about coercing an 8 byte integer to a 4 byte pointer. */
4418 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, pid
,
4419 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
4427 = ptrace (PTRACE_PEEKTEXT
, pid
,
4428 /* Coerce to a uintptr_t first to avoid potential gcc warning
4429 about coercing an 8 byte integer to a 4 byte pointer. */
4430 (PTRACE_ARG3_TYPE
) (uintptr_t) (addr
+ (count
- 1)
4431 * sizeof (PTRACE_XFER_TYPE
)),
4437 /* Copy data to be written over corresponding part of buffer. */
4439 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
4442 /* Write the entire buffer. */
4444 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
4447 ptrace (PTRACE_POKETEXT
, pid
,
4448 /* Coerce to a uintptr_t first to avoid potential gcc warning
4449 about coercing an 8 byte integer to a 4 byte pointer. */
4450 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
,
4451 (PTRACE_ARG4_TYPE
) buffer
[i
]);
4459 /* Non-zero if the kernel supports PTRACE_O_TRACEFORK. */
4460 static int linux_supports_tracefork_flag
;
4463 linux_enable_event_reporting (int pid
)
4465 if (!linux_supports_tracefork_flag
)
4468 ptrace (PTRACE_SETOPTIONS
, pid
, 0, (PTRACE_ARG4_TYPE
) PTRACE_O_TRACECLONE
);
4471 /* Helper functions for linux_test_for_tracefork, called via clone (). */
4474 linux_tracefork_grandchild (void *arg
)
4479 #define STACK_SIZE 4096
4482 linux_tracefork_child (void *arg
)
4484 ptrace (PTRACE_TRACEME
, 0, 0, 0);
4485 kill (getpid (), SIGSTOP
);
4487 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
4490 linux_tracefork_grandchild (NULL
);
4492 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4495 __clone2 (linux_tracefork_grandchild
, arg
, STACK_SIZE
,
4496 CLONE_VM
| SIGCHLD
, NULL
);
4498 clone (linux_tracefork_grandchild
, (char *) arg
+ STACK_SIZE
,
4499 CLONE_VM
| SIGCHLD
, NULL
);
4502 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4507 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
4508 sure that we can enable the option, and that it had the desired
4512 linux_test_for_tracefork (void)
4514 int child_pid
, ret
, status
;
4516 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4517 char *stack
= xmalloc (STACK_SIZE
* 4);
4518 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4520 linux_supports_tracefork_flag
= 0;
4522 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
4524 child_pid
= fork ();
4526 linux_tracefork_child (NULL
);
4528 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4530 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
4532 child_pid
= __clone2 (linux_tracefork_child
, stack
, STACK_SIZE
,
4533 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
4534 #else /* !__ia64__ */
4535 child_pid
= clone (linux_tracefork_child
, stack
+ STACK_SIZE
,
4536 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
4537 #endif /* !__ia64__ */
4539 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4541 if (child_pid
== -1)
4542 perror_with_name ("clone");
4544 ret
= my_waitpid (child_pid
, &status
, 0);
4546 perror_with_name ("waitpid");
4547 else if (ret
!= child_pid
)
4548 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret
);
4549 if (! WIFSTOPPED (status
))
4550 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status
);
4552 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0,
4553 (PTRACE_ARG4_TYPE
) PTRACE_O_TRACEFORK
);
4556 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
4559 warning ("linux_test_for_tracefork: failed to kill child");
4563 ret
= my_waitpid (child_pid
, &status
, 0);
4564 if (ret
!= child_pid
)
4565 warning ("linux_test_for_tracefork: failed to wait for killed child");
4566 else if (!WIFSIGNALED (status
))
4567 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
4568 "killed child", status
);
4573 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
4575 warning ("linux_test_for_tracefork: failed to resume child");
4577 ret
= my_waitpid (child_pid
, &status
, 0);
4579 if (ret
== child_pid
&& WIFSTOPPED (status
)
4580 && status
>> 16 == PTRACE_EVENT_FORK
)
4583 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
4584 if (ret
== 0 && second_pid
!= 0)
4588 linux_supports_tracefork_flag
= 1;
4589 my_waitpid (second_pid
, &second_status
, 0);
4590 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
4592 warning ("linux_test_for_tracefork: failed to kill second child");
4593 my_waitpid (second_pid
, &status
, 0);
4597 warning ("linux_test_for_tracefork: unexpected result from waitpid "
4598 "(%d, status 0x%x)", ret
, status
);
4602 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
4604 warning ("linux_test_for_tracefork: failed to kill child");
4605 my_waitpid (child_pid
, &status
, 0);
4607 while (WIFSTOPPED (status
));
4609 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4611 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4616 linux_look_up_symbols (void)
4618 #ifdef USE_THREAD_DB
4619 struct process_info
*proc
= current_process ();
4621 if (proc
->private->thread_db
!= NULL
)
4624 /* If the kernel supports tracing forks then it also supports tracing
4625 clones, and then we don't need to use the magic thread event breakpoint
4626 to learn about threads. */
4627 thread_db_init (!linux_supports_tracefork_flag
);
4632 linux_request_interrupt (void)
4634 extern unsigned long signal_pid
;
4636 if (!ptid_equal (cont_thread
, null_ptid
)
4637 && !ptid_equal (cont_thread
, minus_one_ptid
))
4639 struct lwp_info
*lwp
;
4642 lwp
= get_thread_lwp (current_inferior
);
4643 lwpid
= lwpid_of (lwp
);
4644 kill_lwp (lwpid
, SIGINT
);
4647 kill_lwp (signal_pid
, SIGINT
);
4650 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
4651 to debugger memory starting at MYADDR. */
4654 linux_read_auxv (CORE_ADDR offset
, unsigned char *myaddr
, unsigned int len
)
4656 char filename
[PATH_MAX
];
4658 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
4660 xsnprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
4662 fd
= open (filename
, O_RDONLY
);
4666 if (offset
!= (CORE_ADDR
) 0
4667 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4670 n
= read (fd
, myaddr
, len
);
4677 /* These breakpoint and watchpoint related wrapper functions simply
4678 pass on the function call if the target has registered a
4679 corresponding function. */
4682 linux_insert_point (char type
, CORE_ADDR addr
, int len
)
4684 if (the_low_target
.insert_point
!= NULL
)
4685 return the_low_target
.insert_point (type
, addr
, len
);
4687 /* Unsupported (see target.h). */
4692 linux_remove_point (char type
, CORE_ADDR addr
, int len
)
4694 if (the_low_target
.remove_point
!= NULL
)
4695 return the_low_target
.remove_point (type
, addr
, len
);
4697 /* Unsupported (see target.h). */
4702 linux_stopped_by_watchpoint (void)
4704 struct lwp_info
*lwp
= get_thread_lwp (current_inferior
);
4706 return lwp
->stopped_by_watchpoint
;
4710 linux_stopped_data_address (void)
4712 struct lwp_info
*lwp
= get_thread_lwp (current_inferior
);
4714 return lwp
->stopped_data_address
;
4717 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4718 #if defined(__mcoldfire__)
4719 /* These should really be defined in the kernel's ptrace.h header. */
4720 #define PT_TEXT_ADDR 49*4
4721 #define PT_DATA_ADDR 50*4
4722 #define PT_TEXT_END_ADDR 51*4
4724 #define PT_TEXT_ADDR 220
4725 #define PT_TEXT_END_ADDR 224
4726 #define PT_DATA_ADDR 228
4727 #elif defined(__TMS320C6X__)
4728 #define PT_TEXT_ADDR (0x10000*4)
4729 #define PT_DATA_ADDR (0x10004*4)
4730 #define PT_TEXT_END_ADDR (0x10008*4)
4733 /* Under uClinux, programs are loaded at non-zero offsets, which we need
4734 to tell gdb about. */
4737 linux_read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
4739 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
4740 unsigned long text
, text_end
, data
;
4741 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
4745 text
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_ADDR
, 0);
4746 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_END_ADDR
, 0);
4747 data
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_DATA_ADDR
, 0);
4751 /* Both text and data offsets produced at compile-time (and so
4752 used by gdb) are relative to the beginning of the program,
4753 with the data segment immediately following the text segment.
4754 However, the actual runtime layout in memory may put the data
4755 somewhere else, so when we send gdb a data base-address, we
4756 use the real data base address and subtract the compile-time
4757 data base-address from it (which is just the length of the
4758 text segment). BSS immediately follows data in both
4761 *data_p
= data
- (text_end
- text
);
4771 linux_qxfer_osdata (const char *annex
,
4772 unsigned char *readbuf
, unsigned const char *writebuf
,
4773 CORE_ADDR offset
, int len
)
4775 return linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
4778 /* Convert a native/host siginfo object, into/from the siginfo in the
4779 layout of the inferiors' architecture. */
4782 siginfo_fixup (struct siginfo
*siginfo
, void *inf_siginfo
, int direction
)
4786 if (the_low_target
.siginfo_fixup
!= NULL
)
4787 done
= the_low_target
.siginfo_fixup (siginfo
, inf_siginfo
, direction
);
4789 /* If there was no callback, or the callback didn't do anything,
4790 then just do a straight memcpy. */
4794 memcpy (siginfo
, inf_siginfo
, sizeof (struct siginfo
));
4796 memcpy (inf_siginfo
, siginfo
, sizeof (struct siginfo
));
4801 linux_xfer_siginfo (const char *annex
, unsigned char *readbuf
,
4802 unsigned const char *writebuf
, CORE_ADDR offset
, int len
)
4805 struct siginfo siginfo
;
4806 char inf_siginfo
[sizeof (struct siginfo
)];
4808 if (current_inferior
== NULL
)
4811 pid
= lwpid_of (get_thread_lwp (current_inferior
));
4814 fprintf (stderr
, "%s siginfo for lwp %d.\n",
4815 readbuf
!= NULL
? "Reading" : "Writing",
4818 if (offset
>= sizeof (siginfo
))
4821 if (ptrace (PTRACE_GETSIGINFO
, pid
, 0, &siginfo
) != 0)
4824 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
4825 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
4826 inferior with a 64-bit GDBSERVER should look the same as debugging it
4827 with a 32-bit GDBSERVER, we need to convert it. */
4828 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
4830 if (offset
+ len
> sizeof (siginfo
))
4831 len
= sizeof (siginfo
) - offset
;
4833 if (readbuf
!= NULL
)
4834 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
4837 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
4839 /* Convert back to ptrace layout before flushing it out. */
4840 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
4842 if (ptrace (PTRACE_SETSIGINFO
, pid
, 0, &siginfo
) != 0)
4849 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4850 so we notice when children change state; as the handler for the
4851 sigsuspend in my_waitpid. */
4854 sigchld_handler (int signo
)
4856 int old_errno
= errno
;
4862 /* fprintf is not async-signal-safe, so call write
4864 if (write (2, "sigchld_handler\n",
4865 sizeof ("sigchld_handler\n") - 1) < 0)
4866 break; /* just ignore */
4870 if (target_is_async_p ())
4871 async_file_mark (); /* trigger a linux_wait */
4877 linux_supports_non_stop (void)
4883 linux_async (int enable
)
4885 int previous
= (linux_event_pipe
[0] != -1);
4888 fprintf (stderr
, "linux_async (%d), previous=%d\n",
4891 if (previous
!= enable
)
4894 sigemptyset (&mask
);
4895 sigaddset (&mask
, SIGCHLD
);
4897 sigprocmask (SIG_BLOCK
, &mask
, NULL
);
4901 if (pipe (linux_event_pipe
) == -1)
4902 fatal ("creating event pipe failed.");
4904 fcntl (linux_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4905 fcntl (linux_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4907 /* Register the event loop handler. */
4908 add_file_handler (linux_event_pipe
[0],
4909 handle_target_event
, NULL
);
4911 /* Always trigger a linux_wait. */
4916 delete_file_handler (linux_event_pipe
[0]);
4918 close (linux_event_pipe
[0]);
4919 close (linux_event_pipe
[1]);
4920 linux_event_pipe
[0] = -1;
4921 linux_event_pipe
[1] = -1;
4924 sigprocmask (SIG_UNBLOCK
, &mask
, NULL
);
4931 linux_start_non_stop (int nonstop
)
4933 /* Register or unregister from event-loop accordingly. */
4934 linux_async (nonstop
);
4939 linux_supports_multi_process (void)
4945 linux_supports_disable_randomization (void)
4947 #ifdef HAVE_PERSONALITY
4955 linux_supports_agent (void)
4960 /* Enumerate spufs IDs for process PID. */
4962 spu_enumerate_spu_ids (long pid
, unsigned char *buf
, CORE_ADDR offset
, int len
)
4968 struct dirent
*entry
;
4970 sprintf (path
, "/proc/%ld/fd", pid
);
4971 dir
= opendir (path
);
4976 while ((entry
= readdir (dir
)) != NULL
)
4982 fd
= atoi (entry
->d_name
);
4986 sprintf (path
, "/proc/%ld/fd/%d", pid
, fd
);
4987 if (stat (path
, &st
) != 0)
4989 if (!S_ISDIR (st
.st_mode
))
4992 if (statfs (path
, &stfs
) != 0)
4994 if (stfs
.f_type
!= SPUFS_MAGIC
)
4997 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4999 *(unsigned int *)(buf
+ pos
- offset
) = fd
;
5009 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
5010 object type, using the /proc file system. */
5012 linux_qxfer_spu (const char *annex
, unsigned char *readbuf
,
5013 unsigned const char *writebuf
,
5014 CORE_ADDR offset
, int len
)
5016 long pid
= lwpid_of (get_thread_lwp (current_inferior
));
5021 if (!writebuf
&& !readbuf
)
5029 return spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
5032 sprintf (buf
, "/proc/%ld/fd/%s", pid
, annex
);
5033 fd
= open (buf
, writebuf
? O_WRONLY
: O_RDONLY
);
5038 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
5045 ret
= write (fd
, writebuf
, (size_t) len
);
5047 ret
= read (fd
, readbuf
, (size_t) len
);
5053 #if defined PT_GETDSBT || defined PTRACE_GETFDPIC
5054 struct target_loadseg
5056 /* Core address to which the segment is mapped. */
5058 /* VMA recorded in the program header. */
5060 /* Size of this segment in memory. */
5064 # if defined PT_GETDSBT
5065 struct target_loadmap
5067 /* Protocol version number, must be zero. */
5069 /* Pointer to the DSBT table, its size, and the DSBT index. */
5070 unsigned *dsbt_table
;
5071 unsigned dsbt_size
, dsbt_index
;
5072 /* Number of segments in this map. */
5074 /* The actual memory map. */
5075 struct target_loadseg segs
[/*nsegs*/];
5077 # define LINUX_LOADMAP PT_GETDSBT
5078 # define LINUX_LOADMAP_EXEC PTRACE_GETDSBT_EXEC
5079 # define LINUX_LOADMAP_INTERP PTRACE_GETDSBT_INTERP
5081 struct target_loadmap
5083 /* Protocol version number, must be zero. */
5085 /* Number of segments in this map. */
5087 /* The actual memory map. */
5088 struct target_loadseg segs
[/*nsegs*/];
5090 # define LINUX_LOADMAP PTRACE_GETFDPIC
5091 # define LINUX_LOADMAP_EXEC PTRACE_GETFDPIC_EXEC
5092 # define LINUX_LOADMAP_INTERP PTRACE_GETFDPIC_INTERP
5096 linux_read_loadmap (const char *annex
, CORE_ADDR offset
,
5097 unsigned char *myaddr
, unsigned int len
)
5099 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
5101 struct target_loadmap
*data
= NULL
;
5102 unsigned int actual_length
, copy_length
;
5104 if (strcmp (annex
, "exec") == 0)
5105 addr
= (int) LINUX_LOADMAP_EXEC
;
5106 else if (strcmp (annex
, "interp") == 0)
5107 addr
= (int) LINUX_LOADMAP_INTERP
;
5111 if (ptrace (LINUX_LOADMAP
, pid
, addr
, &data
) != 0)
5117 actual_length
= sizeof (struct target_loadmap
)
5118 + sizeof (struct target_loadseg
) * data
->nsegs
;
5120 if (offset
< 0 || offset
> actual_length
)
5123 copy_length
= actual_length
- offset
< len
? actual_length
- offset
: len
;
5124 memcpy (myaddr
, (char *) data
+ offset
, copy_length
);
5128 # define linux_read_loadmap NULL
5129 #endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */
5132 linux_process_qsupported (const char *query
)
5134 if (the_low_target
.process_qsupported
!= NULL
)
5135 the_low_target
.process_qsupported (query
);
5139 linux_supports_tracepoints (void)
5141 if (*the_low_target
.supports_tracepoints
== NULL
)
5144 return (*the_low_target
.supports_tracepoints
) ();
5148 linux_read_pc (struct regcache
*regcache
)
5150 if (the_low_target
.get_pc
== NULL
)
5153 return (*the_low_target
.get_pc
) (regcache
);
5157 linux_write_pc (struct regcache
*regcache
, CORE_ADDR pc
)
5159 gdb_assert (the_low_target
.set_pc
!= NULL
);
5161 (*the_low_target
.set_pc
) (regcache
, pc
);
5165 linux_thread_stopped (struct thread_info
*thread
)
5167 return get_thread_lwp (thread
)->stopped
;
5170 /* This exposes stop-all-threads functionality to other modules. */
5173 linux_pause_all (int freeze
)
5175 stop_all_lwps (freeze
, NULL
);
5178 /* This exposes unstop-all-threads functionality to other gdbserver
5182 linux_unpause_all (int unfreeze
)
5184 unstop_all_lwps (unfreeze
, NULL
);
5188 linux_prepare_to_access_memory (void)
5190 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
5193 linux_pause_all (1);
5198 linux_done_accessing_memory (void)
5200 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
5203 linux_unpause_all (1);
5207 linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint
, CORE_ADDR tpaddr
,
5208 CORE_ADDR collector
,
5211 CORE_ADDR
*jump_entry
,
5212 CORE_ADDR
*trampoline
,
5213 ULONGEST
*trampoline_size
,
5214 unsigned char *jjump_pad_insn
,
5215 ULONGEST
*jjump_pad_insn_size
,
5216 CORE_ADDR
*adjusted_insn_addr
,
5217 CORE_ADDR
*adjusted_insn_addr_end
,
5220 return (*the_low_target
.install_fast_tracepoint_jump_pad
)
5221 (tpoint
, tpaddr
, collector
, lockaddr
, orig_size
,
5222 jump_entry
, trampoline
, trampoline_size
,
5223 jjump_pad_insn
, jjump_pad_insn_size
,
5224 adjusted_insn_addr
, adjusted_insn_addr_end
,
5228 static struct emit_ops
*
5229 linux_emit_ops (void)
5231 if (the_low_target
.emit_ops
!= NULL
)
5232 return (*the_low_target
.emit_ops
) ();
5238 linux_get_min_fast_tracepoint_insn_len (void)
5240 return (*the_low_target
.get_min_fast_tracepoint_insn_len
) ();
5243 /* Extract &phdr and num_phdr in the inferior. Return 0 on success. */
5246 get_phdr_phnum_from_proc_auxv (const int pid
, const int is_elf64
,
5247 CORE_ADDR
*phdr_memaddr
, int *num_phdr
)
5249 char filename
[PATH_MAX
];
5251 const int auxv_size
= is_elf64
5252 ? sizeof (Elf64_auxv_t
) : sizeof (Elf32_auxv_t
);
5253 char buf
[sizeof (Elf64_auxv_t
)]; /* The larger of the two. */
5255 xsnprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
5257 fd
= open (filename
, O_RDONLY
);
5263 while (read (fd
, buf
, auxv_size
) == auxv_size
5264 && (*phdr_memaddr
== 0 || *num_phdr
== 0))
5268 Elf64_auxv_t
*const aux
= (Elf64_auxv_t
*) buf
;
5270 switch (aux
->a_type
)
5273 *phdr_memaddr
= aux
->a_un
.a_val
;
5276 *num_phdr
= aux
->a_un
.a_val
;
5282 Elf32_auxv_t
*const aux
= (Elf32_auxv_t
*) buf
;
5284 switch (aux
->a_type
)
5287 *phdr_memaddr
= aux
->a_un
.a_val
;
5290 *num_phdr
= aux
->a_un
.a_val
;
5298 if (*phdr_memaddr
== 0 || *num_phdr
== 0)
5300 warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: "
5301 "phdr_memaddr = %ld, phdr_num = %d",
5302 (long) *phdr_memaddr
, *num_phdr
);
5309 /* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */
5312 get_dynamic (const int pid
, const int is_elf64
)
5314 CORE_ADDR phdr_memaddr
, relocation
;
5316 unsigned char *phdr_buf
;
5317 const int phdr_size
= is_elf64
? sizeof (Elf64_Phdr
) : sizeof (Elf32_Phdr
);
5319 if (get_phdr_phnum_from_proc_auxv (pid
, is_elf64
, &phdr_memaddr
, &num_phdr
))
5322 gdb_assert (num_phdr
< 100); /* Basic sanity check. */
5323 phdr_buf
= alloca (num_phdr
* phdr_size
);
5325 if (linux_read_memory (phdr_memaddr
, phdr_buf
, num_phdr
* phdr_size
))
5328 /* Compute relocation: it is expected to be 0 for "regular" executables,
5329 non-zero for PIE ones. */
5331 for (i
= 0; relocation
== -1 && i
< num_phdr
; i
++)
5334 Elf64_Phdr
*const p
= (Elf64_Phdr
*) (phdr_buf
+ i
* phdr_size
);
5336 if (p
->p_type
== PT_PHDR
)
5337 relocation
= phdr_memaddr
- p
->p_vaddr
;
5341 Elf32_Phdr
*const p
= (Elf32_Phdr
*) (phdr_buf
+ i
* phdr_size
);
5343 if (p
->p_type
== PT_PHDR
)
5344 relocation
= phdr_memaddr
- p
->p_vaddr
;
5347 if (relocation
== -1)
5349 /* PT_PHDR is optional, but necessary for PIE in general. Fortunately
5350 any real world executables, including PIE executables, have always
5351 PT_PHDR present. PT_PHDR is not present in some shared libraries or
5352 in fpc (Free Pascal 2.4) binaries but neither of those have a need for
5353 or present DT_DEBUG anyway (fpc binaries are statically linked).
5355 Therefore if there exists DT_DEBUG there is always also PT_PHDR.
5357 GDB could find RELOCATION also from AT_ENTRY - e_entry. */
5362 for (i
= 0; i
< num_phdr
; i
++)
5366 Elf64_Phdr
*const p
= (Elf64_Phdr
*) (phdr_buf
+ i
* phdr_size
);
5368 if (p
->p_type
== PT_DYNAMIC
)
5369 return p
->p_vaddr
+ relocation
;
5373 Elf32_Phdr
*const p
= (Elf32_Phdr
*) (phdr_buf
+ i
* phdr_size
);
5375 if (p
->p_type
== PT_DYNAMIC
)
5376 return p
->p_vaddr
+ relocation
;
5383 /* Return &_r_debug in the inferior, or -1 if not present. Return value
5384 can be 0 if the inferior does not yet have the library list initialized. */
5387 get_r_debug (const int pid
, const int is_elf64
)
5389 CORE_ADDR dynamic_memaddr
;
5390 const int dyn_size
= is_elf64
? sizeof (Elf64_Dyn
) : sizeof (Elf32_Dyn
);
5391 unsigned char buf
[sizeof (Elf64_Dyn
)]; /* The larger of the two. */
5393 dynamic_memaddr
= get_dynamic (pid
, is_elf64
);
5394 if (dynamic_memaddr
== 0)
5395 return (CORE_ADDR
) -1;
5397 while (linux_read_memory (dynamic_memaddr
, buf
, dyn_size
) == 0)
5401 Elf64_Dyn
*const dyn
= (Elf64_Dyn
*) buf
;
5403 if (dyn
->d_tag
== DT_DEBUG
)
5404 return dyn
->d_un
.d_val
;
5406 if (dyn
->d_tag
== DT_NULL
)
5411 Elf32_Dyn
*const dyn
= (Elf32_Dyn
*) buf
;
5413 if (dyn
->d_tag
== DT_DEBUG
)
5414 return dyn
->d_un
.d_val
;
5416 if (dyn
->d_tag
== DT_NULL
)
5420 dynamic_memaddr
+= dyn_size
;
5423 return (CORE_ADDR
) -1;
5426 /* Read one pointer from MEMADDR in the inferior. */
5429 read_one_ptr (CORE_ADDR memaddr
, CORE_ADDR
*ptr
, int ptr_size
)
5432 return linux_read_memory (memaddr
, (unsigned char *) ptr
, ptr_size
);
5435 struct link_map_offsets
5437 /* Offset and size of r_debug.r_version. */
5438 int r_version_offset
;
5440 /* Offset and size of r_debug.r_map. */
5443 /* Offset to l_addr field in struct link_map. */
5446 /* Offset to l_name field in struct link_map. */
5449 /* Offset to l_ld field in struct link_map. */
5452 /* Offset to l_next field in struct link_map. */
5455 /* Offset to l_prev field in struct link_map. */
5459 /* Construct qXfer:libraries:read reply. */
5462 linux_qxfer_libraries_svr4 (const char *annex
, unsigned char *readbuf
,
5463 unsigned const char *writebuf
,
5464 CORE_ADDR offset
, int len
)
5467 unsigned document_len
;
5468 struct process_info_private
*const priv
= current_process ()->private;
5469 char filename
[PATH_MAX
];
5472 static const struct link_map_offsets lmo_32bit_offsets
=
5474 0, /* r_version offset. */
5475 4, /* r_debug.r_map offset. */
5476 0, /* l_addr offset in link_map. */
5477 4, /* l_name offset in link_map. */
5478 8, /* l_ld offset in link_map. */
5479 12, /* l_next offset in link_map. */
5480 16 /* l_prev offset in link_map. */
5483 static const struct link_map_offsets lmo_64bit_offsets
=
5485 0, /* r_version offset. */
5486 8, /* r_debug.r_map offset. */
5487 0, /* l_addr offset in link_map. */
5488 8, /* l_name offset in link_map. */
5489 16, /* l_ld offset in link_map. */
5490 24, /* l_next offset in link_map. */
5491 32 /* l_prev offset in link_map. */
5493 const struct link_map_offsets
*lmo
;
5495 if (writebuf
!= NULL
)
5497 if (readbuf
== NULL
)
5500 pid
= lwpid_of (get_thread_lwp (current_inferior
));
5501 xsnprintf (filename
, sizeof filename
, "/proc/%d/exe", pid
);
5502 is_elf64
= elf_64_file_p (filename
);
5503 lmo
= is_elf64
? &lmo_64bit_offsets
: &lmo_32bit_offsets
;
5505 if (priv
->r_debug
== 0)
5506 priv
->r_debug
= get_r_debug (pid
, is_elf64
);
5508 if (priv
->r_debug
== (CORE_ADDR
) -1 || priv
->r_debug
== 0)
5510 document
= xstrdup ("<library-list-svr4 version=\"1.0\"/>\n");
5514 int allocated
= 1024;
5516 const int ptr_size
= is_elf64
? 8 : 4;
5517 CORE_ADDR lm_addr
, lm_prev
, l_name
, l_addr
, l_ld
, l_next
, l_prev
;
5518 int r_version
, header_done
= 0;
5520 document
= xmalloc (allocated
);
5521 strcpy (document
, "<library-list-svr4 version=\"1.0\"");
5522 p
= document
+ strlen (document
);
5525 if (linux_read_memory (priv
->r_debug
+ lmo
->r_version_offset
,
5526 (unsigned char *) &r_version
,
5527 sizeof (r_version
)) != 0
5530 warning ("unexpected r_debug version %d", r_version
);
5534 if (read_one_ptr (priv
->r_debug
+ lmo
->r_map_offset
,
5535 &lm_addr
, ptr_size
) != 0)
5537 warning ("unable to read r_map from 0x%lx",
5538 (long) priv
->r_debug
+ lmo
->r_map_offset
);
5543 while (read_one_ptr (lm_addr
+ lmo
->l_name_offset
,
5544 &l_name
, ptr_size
) == 0
5545 && read_one_ptr (lm_addr
+ lmo
->l_addr_offset
,
5546 &l_addr
, ptr_size
) == 0
5547 && read_one_ptr (lm_addr
+ lmo
->l_ld_offset
,
5548 &l_ld
, ptr_size
) == 0
5549 && read_one_ptr (lm_addr
+ lmo
->l_prev_offset
,
5550 &l_prev
, ptr_size
) == 0
5551 && read_one_ptr (lm_addr
+ lmo
->l_next_offset
,
5552 &l_next
, ptr_size
) == 0)
5554 unsigned char libname
[PATH_MAX
];
5556 if (lm_prev
!= l_prev
)
5558 warning ("Corrupted shared library list: 0x%lx != 0x%lx",
5559 (long) lm_prev
, (long) l_prev
);
5563 /* Not checking for error because reading may stop before
5564 we've got PATH_MAX worth of characters. */
5566 linux_read_memory (l_name
, libname
, sizeof (libname
) - 1);
5567 libname
[sizeof (libname
) - 1] = '\0';
5568 if (libname
[0] != '\0')
5570 /* 6x the size for xml_escape_text below. */
5571 size_t len
= 6 * strlen ((char *) libname
);
5576 /* Terminate `<library-list-svr4'. */
5581 while (allocated
< p
- document
+ len
+ 200)
5583 /* Expand to guarantee sufficient storage. */
5584 uintptr_t document_len
= p
- document
;
5586 document
= xrealloc (document
, 2 * allocated
);
5588 p
= document
+ document_len
;
5591 name
= xml_escape_text ((char *) libname
);
5592 p
+= sprintf (p
, "<library name=\"%s\" lm=\"0x%lx\" "
5593 "l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>",
5594 name
, (unsigned long) lm_addr
,
5595 (unsigned long) l_addr
, (unsigned long) l_ld
);
5598 else if (lm_prev
== 0)
5600 sprintf (p
, " main-lm=\"0x%lx\"", (unsigned long) lm_addr
);
5611 strcpy (p
, "</library-list-svr4>");
5614 document_len
= strlen (document
);
5615 if (offset
< document_len
)
5616 document_len
-= offset
;
5619 if (len
> document_len
)
5622 memcpy (readbuf
, document
+ offset
, len
);
5628 static struct target_ops linux_target_ops
= {
5629 linux_create_inferior
,
5638 linux_fetch_registers
,
5639 linux_store_registers
,
5640 linux_prepare_to_access_memory
,
5641 linux_done_accessing_memory
,
5644 linux_look_up_symbols
,
5645 linux_request_interrupt
,
5649 linux_stopped_by_watchpoint
,
5650 linux_stopped_data_address
,
5651 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
5656 #ifdef USE_THREAD_DB
5657 thread_db_get_tls_address
,
5662 hostio_last_error_from_errno
,
5665 linux_supports_non_stop
,
5667 linux_start_non_stop
,
5668 linux_supports_multi_process
,
5669 #ifdef USE_THREAD_DB
5670 thread_db_handle_monitor_command
,
5674 linux_common_core_of_thread
,
5676 linux_process_qsupported
,
5677 linux_supports_tracepoints
,
5680 linux_thread_stopped
,
5684 linux_cancel_breakpoints
,
5685 linux_stabilize_threads
,
5686 linux_install_fast_tracepoint_jump_pad
,
5688 linux_supports_disable_randomization
,
5689 linux_get_min_fast_tracepoint_insn_len
,
5690 linux_qxfer_libraries_svr4
,
5691 linux_supports_agent
,
5695 linux_init_signals ()
5697 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
5698 to find what the cancel signal actually is. */
5699 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
5700 signal (__SIGRTMIN
+1, SIG_IGN
);
5705 initialize_low (void)
5707 struct sigaction sigchld_action
;
5708 memset (&sigchld_action
, 0, sizeof (sigchld_action
));
5709 set_target_ops (&linux_target_ops
);
5710 set_breakpoint_data (the_low_target
.breakpoint
,
5711 the_low_target
.breakpoint_len
);
5712 linux_init_signals ();
5713 linux_test_for_tracefork ();
5714 #ifdef HAVE_LINUX_REGSETS
5715 for (num_regsets
= 0; target_regsets
[num_regsets
].size
>= 0; num_regsets
++)
5717 disabled_regsets
= xmalloc (num_regsets
);
5720 sigchld_action
.sa_handler
= sigchld_handler
;
5721 sigemptyset (&sigchld_action
.sa_mask
);
5722 sigchld_action
.sa_flags
= SA_RESTART
;
5723 sigaction (SIGCHLD
, &sigchld_action
, NULL
);