1 /* Low level interface to ptrace, for the remote server for GDB.
2 Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
3 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #include "linux-low.h"
22 #include "ansidecl.h" /* For ATTRIBUTE_PACKED, must be bug in external.h. */
23 #include "elf/common.h"
24 #include "elf/external.h"
28 #include <sys/param.h>
29 #include <sys/ptrace.h>
31 #include <sys/ioctl.h>
37 #include <sys/syscall.h>
41 #include <sys/types.h>
44 #ifndef PTRACE_GETSIGINFO
45 # define PTRACE_GETSIGINFO 0x4202
46 # define PTRACE_SETSIGINFO 0x4203
53 /* If the system headers did not provide the constants, hard-code the normal
55 #ifndef PTRACE_EVENT_FORK
57 #define PTRACE_SETOPTIONS 0x4200
58 #define PTRACE_GETEVENTMSG 0x4201
60 /* options set using PTRACE_SETOPTIONS */
61 #define PTRACE_O_TRACESYSGOOD 0x00000001
62 #define PTRACE_O_TRACEFORK 0x00000002
63 #define PTRACE_O_TRACEVFORK 0x00000004
64 #define PTRACE_O_TRACECLONE 0x00000008
65 #define PTRACE_O_TRACEEXEC 0x00000010
66 #define PTRACE_O_TRACEVFORKDONE 0x00000020
67 #define PTRACE_O_TRACEEXIT 0x00000040
69 /* Wait extended result codes for the above trace options. */
70 #define PTRACE_EVENT_FORK 1
71 #define PTRACE_EVENT_VFORK 2
72 #define PTRACE_EVENT_CLONE 3
73 #define PTRACE_EVENT_EXEC 4
74 #define PTRACE_EVENT_VFORK_DONE 5
75 #define PTRACE_EVENT_EXIT 6
77 #endif /* PTRACE_EVENT_FORK */
79 /* We can't always assume that this flag is available, but all systems
80 with the ptrace event handlers also have __WALL, so it's safe to use
83 #define __WALL 0x40000000 /* Wait for any child. */
87 #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
92 /* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
93 representation of the thread ID.
95 ``all_lwps'' is keyed by the process ID - which on Linux is (presently)
96 the same as the LWP ID.
98 ``all_processes'' is keyed by the "overall process ID", which
99 GNU/Linux calls tgid, "thread group ID". */
101 struct inferior_list all_lwps;
103 /* A list of all unknown processes which receive stop signals. Some other
104 process will presumably claim each of these as forked children
107 struct inferior_list stopped_pids;
109 /* FIXME this is a bit of a hack, and could be removed. */
110 int stopping_threads;
112 /* FIXME make into a target method? */
113 int using_threads = 1;
115 /* This flag is true iff we've just created or attached to our first
116 inferior but it has not stopped yet. As soon as it does, we need
117 to call the low target's arch_setup callback. Doing this only on
118 the first inferior avoids reinializing the architecture on every
119 inferior, and avoids messing with the register caches of the
120 already running inferiors. NOTE: this assumes all inferiors under
121 control of gdbserver have the same architecture. */
122 static int new_inferior;
124 static void linux_resume_one_lwp (struct lwp_info *lwp,
125 int step, int signal, siginfo_t *info);
126 static void linux_resume (struct thread_resume *resume_info, size_t n);
127 static void stop_all_lwps (void);
128 static int linux_wait_for_event (ptid_t ptid, int *wstat, int options);
129 static int check_removed_breakpoint (struct lwp_info *event_child);
130 static void *add_lwp (ptid_t ptid);
131 static int my_waitpid (int pid, int *status, int flags);
132 static int linux_stopped_by_watchpoint (void);
133 static void mark_lwp_dead (struct lwp_info *lwp, int wstat);
135 struct pending_signals
139 struct pending_signals *prev;
142 #define PTRACE_ARG3_TYPE long
143 #define PTRACE_XFER_TYPE long
145 #ifdef HAVE_LINUX_REGSETS
146 static char *disabled_regsets;
147 static int num_regsets;
150 /* The read/write ends of the pipe registered as waitable file in the
152 static int linux_event_pipe[2] = { -1, -1 };
154 /* True if we're currently in async mode. */
155 #define target_is_async_p() (linux_event_pipe[0] != -1)
157 static void send_sigstop (struct inferior_list_entry *entry);
158 static void wait_for_sigstop (struct inferior_list_entry *entry);
160 /* Accepts an integer PID; Returns a string representing a file that
161 can be opened to get info for the child process.
162 Space for the result is malloc'd, caller must free. */
165 linux_child_pid_to_exec_file (int pid)
169 name1 = xmalloc (MAXPATHLEN);
170 name2 = xmalloc (MAXPATHLEN);
171 memset (name2, 0, MAXPATHLEN);
173 sprintf (name1, "/proc/%d/exe", pid);
174 if (readlink (name1, name2, MAXPATHLEN) > 0)
186 /* Return non-zero if HEADER is a 64-bit ELF file. */
189 elf_64_header_p (const Elf64_External_Ehdr *header)
191 return (header->e_ident[EI_MAG0] == ELFMAG0
192 && header->e_ident[EI_MAG1] == ELFMAG1
193 && header->e_ident[EI_MAG2] == ELFMAG2
194 && header->e_ident[EI_MAG3] == ELFMAG3
195 && header->e_ident[EI_CLASS] == ELFCLASS64);
198 /* Return non-zero if FILE is a 64-bit ELF file,
199 zero if the file is not a 64-bit ELF file,
200 and -1 if the file is not accessible or doesn't exist. */
203 elf_64_file_p (const char *file)
205 Elf64_External_Ehdr header;
208 fd = open (file, O_RDONLY);
212 if (read (fd, &header, sizeof (header)) != sizeof (header))
219 return elf_64_header_p (&header);
223 delete_lwp (struct lwp_info *lwp)
225 remove_thread (get_lwp_thread (lwp));
226 remove_inferior (&all_lwps, &lwp->head);
227 free (lwp->arch_private);
231 /* Add a process to the common process list, and set its private
234 static struct process_info *
235 linux_add_process (int pid, int attached)
237 struct process_info *proc;
239 /* Is this the first process? If so, then set the arch. */
240 if (all_processes.head == NULL)
243 proc = add_process (pid, attached);
244 proc->private = xcalloc (1, sizeof (*proc->private));
246 if (the_low_target.new_process != NULL)
247 proc->private->arch_private = the_low_target.new_process ();
252 /* Remove a process from the common process list,
253 also freeing all private data. */
256 linux_remove_process (struct process_info *process)
258 free (process->private->arch_private);
259 free (process->private);
260 remove_process (process);
263 /* Handle a GNU/Linux extended wait response. If we see a clone
264 event, we need to add the new LWP to our list (and not report the
265 trap to higher layers). */
268 handle_extended_wait (struct lwp_info *event_child, int wstat)
270 int event = wstat >> 16;
271 struct lwp_info *new_lwp;
273 if (event == PTRACE_EVENT_CLONE)
276 unsigned long new_pid;
277 int ret, status = W_STOPCODE (SIGSTOP);
279 ptrace (PTRACE_GETEVENTMSG, lwpid_of (event_child), 0, &new_pid);
281 /* If we haven't already seen the new PID stop, wait for it now. */
282 if (! pull_pid_from_list (&stopped_pids, new_pid))
284 /* The new child has a pending SIGSTOP. We can't affect it until it
285 hits the SIGSTOP, but we're already attached. */
287 ret = my_waitpid (new_pid, &status, __WALL);
290 perror_with_name ("waiting for new child");
291 else if (ret != new_pid)
292 warning ("wait returned unexpected PID %d", ret);
293 else if (!WIFSTOPPED (status))
294 warning ("wait returned unexpected status 0x%x", status);
297 ptrace (PTRACE_SETOPTIONS, new_pid, 0, PTRACE_O_TRACECLONE);
299 ptid = ptid_build (pid_of (event_child), new_pid, 0);
300 new_lwp = (struct lwp_info *) add_lwp (ptid);
301 add_thread (ptid, new_lwp);
303 /* Either we're going to immediately resume the new thread
304 or leave it stopped. linux_resume_one_lwp is a nop if it
305 thinks the thread is currently running, so set this first
306 before calling linux_resume_one_lwp. */
307 new_lwp->stopped = 1;
309 /* Normally we will get the pending SIGSTOP. But in some cases
310 we might get another signal delivered to the group first.
311 If we do get another signal, be sure not to lose it. */
312 if (WSTOPSIG (status) == SIGSTOP)
314 if (! stopping_threads)
315 linux_resume_one_lwp (new_lwp, 0, 0, NULL);
319 new_lwp->stop_expected = 1;
320 if (stopping_threads)
322 new_lwp->status_pending_p = 1;
323 new_lwp->status_pending = status;
326 /* Pass the signal on. This is what GDB does - except
327 shouldn't we really report it instead? */
328 linux_resume_one_lwp (new_lwp, 0, WSTOPSIG (status), NULL);
331 /* Always resume the current thread. If we are stopping
332 threads, it will have a pending SIGSTOP; we may as well
334 linux_resume_one_lwp (event_child, event_child->stepping, 0, NULL);
338 /* This function should only be called if the process got a SIGTRAP.
339 The SIGTRAP could mean several things.
341 On i386, where decr_pc_after_break is non-zero:
342 If we were single-stepping this process using PTRACE_SINGLESTEP,
343 we will get only the one SIGTRAP (even if the instruction we
344 stepped over was a breakpoint). The value of $eip will be the
346 If we continue the process using PTRACE_CONT, we will get a
347 SIGTRAP when we hit a breakpoint. The value of $eip will be
348 the instruction after the breakpoint (i.e. needs to be
349 decremented). If we report the SIGTRAP to GDB, we must also
350 report the undecremented PC. If we cancel the SIGTRAP, we
351 must resume at the decremented PC.
353 (Presumably, not yet tested) On a non-decr_pc_after_break machine
354 with hardware or kernel single-step:
355 If we single-step over a breakpoint instruction, our PC will
356 point at the following instruction. If we continue and hit a
357 breakpoint instruction, our PC will point at the breakpoint
363 CORE_ADDR stop_pc = (*the_low_target.get_pc) ();
365 if (! get_thread_lwp (current_inferior)->stepping)
366 stop_pc -= the_low_target.decr_pc_after_break;
369 fprintf (stderr, "stop pc is 0x%lx\n", (long) stop_pc);
375 add_lwp (ptid_t ptid)
377 struct lwp_info *lwp;
379 lwp = (struct lwp_info *) xmalloc (sizeof (*lwp));
380 memset (lwp, 0, sizeof (*lwp));
384 if (the_low_target.new_thread != NULL)
385 lwp->arch_private = the_low_target.new_thread ();
387 add_inferior_to_list (&all_lwps, &lwp->head);
392 /* Start an inferior process and returns its pid.
393 ALLARGS is a vector of program-name and args. */
396 linux_create_inferior (char *program, char **allargs)
398 struct lwp_info *new_lwp;
402 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
408 perror_with_name ("fork");
412 ptrace (PTRACE_TRACEME, 0, 0, 0);
414 signal (__SIGRTMIN + 1, SIG_DFL);
418 execv (program, allargs);
420 execvp (program, allargs);
422 fprintf (stderr, "Cannot exec %s: %s.\n", program,
428 linux_add_process (pid, 0);
430 ptid = ptid_build (pid, pid, 0);
431 new_lwp = add_lwp (ptid);
432 add_thread (ptid, new_lwp);
433 new_lwp->must_set_ptrace_flags = 1;
438 /* Attach to an inferior process. */
441 linux_attach_lwp_1 (unsigned long lwpid, int initial)
444 struct lwp_info *new_lwp;
446 if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) != 0)
450 /* If we fail to attach to an LWP, just warn. */
451 fprintf (stderr, "Cannot attach to lwp %ld: %s (%d)\n", lwpid,
452 strerror (errno), errno);
457 /* If we fail to attach to a process, report an error. */
458 error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid,
459 strerror (errno), errno);
463 /* NOTE/FIXME: This lwp might have not been the tgid. */
464 ptid = ptid_build (lwpid, lwpid, 0);
467 /* Note that extracting the pid from the current inferior is
468 safe, since we're always called in the context of the same
469 process as this new thread. */
470 int pid = pid_of (get_thread_lwp (current_inferior));
471 ptid = ptid_build (pid, lwpid, 0);
474 new_lwp = (struct lwp_info *) add_lwp (ptid);
475 add_thread (ptid, new_lwp);
477 /* We need to wait for SIGSTOP before being able to make the next
478 ptrace call on this LWP. */
479 new_lwp->must_set_ptrace_flags = 1;
481 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
484 There are several cases to consider here:
486 1) gdbserver has already attached to the process and is being notified
487 of a new thread that is being created.
488 In this case we should ignore that SIGSTOP and resume the process.
489 This is handled below by setting stop_expected = 1.
491 2) This is the first thread (the process thread), and we're attaching
492 to it via attach_inferior.
493 In this case we want the process thread to stop.
494 This is handled by having linux_attach clear stop_expected after
496 ??? If the process already has several threads we leave the other
499 3) GDB is connecting to gdbserver and is requesting an enumeration of all
501 In this case we want the thread to stop.
502 FIXME: This case is currently not properly handled.
503 We should wait for the SIGSTOP but don't. Things work apparently
504 because enough time passes between when we ptrace (ATTACH) and when
505 gdb makes the next ptrace call on the thread.
507 On the other hand, if we are currently trying to stop all threads, we
508 should treat the new thread as if we had sent it a SIGSTOP. This works
509 because we are guaranteed that the add_lwp call above added us to the
510 end of the list, and so the new thread has not yet reached
511 wait_for_sigstop (but will). */
512 if (! stopping_threads)
513 new_lwp->stop_expected = 1;
517 linux_attach_lwp (unsigned long lwpid)
519 linux_attach_lwp_1 (lwpid, 0);
523 linux_attach (unsigned long pid)
525 struct lwp_info *lwp;
527 linux_attach_lwp_1 (pid, 1);
529 linux_add_process (pid, 1);
533 /* Don't ignore the initial SIGSTOP if we just attached to this
534 process. It will be collected by wait shortly. */
535 lwp = (struct lwp_info *) find_inferior_id (&all_lwps,
536 ptid_build (pid, pid, 0));
537 lwp->stop_expected = 0;
550 second_thread_of_pid_p (struct inferior_list_entry *entry, void *args)
552 struct counter *counter = args;
554 if (ptid_get_pid (entry->id) == counter->pid)
556 if (++counter->count > 1)
564 last_thread_of_process_p (struct thread_info *thread)
566 ptid_t ptid = ((struct inferior_list_entry *)thread)->id;
567 int pid = ptid_get_pid (ptid);
568 struct counter counter = { pid , 0 };
570 return (find_inferior (&all_threads,
571 second_thread_of_pid_p, &counter) == NULL);
574 /* Kill the inferior lwp. */
577 linux_kill_one_lwp (struct inferior_list_entry *entry, void *args)
579 struct thread_info *thread = (struct thread_info *) entry;
580 struct lwp_info *lwp = get_thread_lwp (thread);
582 int pid = * (int *) args;
584 if (ptid_get_pid (entry->id) != pid)
587 /* We avoid killing the first thread here, because of a Linux kernel (at
588 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
589 the children get a chance to be reaped, it will remain a zombie
592 if (lwpid_of (lwp) == pid)
595 fprintf (stderr, "lkop: is last of process %s\n",
596 target_pid_to_str (entry->id));
600 /* If we're killing a running inferior, make sure it is stopped
601 first, as PTRACE_KILL will not work otherwise. */
603 send_sigstop (&lwp->head);
607 ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0);
609 /* Make sure it died. The loop is most likely unnecessary. */
610 pid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
611 } while (pid > 0 && WIFSTOPPED (wstat));
619 struct process_info *process;
620 struct lwp_info *lwp;
621 struct thread_info *thread;
625 process = find_process_pid (pid);
629 find_inferior (&all_threads, linux_kill_one_lwp, &pid);
631 /* See the comment in linux_kill_one_lwp. We did not kill the first
632 thread in the list, so do so now. */
633 lwp = find_lwp_pid (pid_to_ptid (pid));
634 thread = get_lwp_thread (lwp);
637 fprintf (stderr, "lk_1: killing lwp %ld, for pid: %d\n",
638 lwpid_of (lwp), pid);
640 /* If we're killing a running inferior, make sure it is stopped
641 first, as PTRACE_KILL will not work otherwise. */
643 send_sigstop (&lwp->head);
647 ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0);
649 /* Make sure it died. The loop is most likely unnecessary. */
650 lwpid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
651 } while (lwpid > 0 && WIFSTOPPED (wstat));
654 linux_remove_process (process);
659 linux_detach_one_lwp (struct inferior_list_entry *entry, void *args)
661 struct thread_info *thread = (struct thread_info *) entry;
662 struct lwp_info *lwp = get_thread_lwp (thread);
663 int pid = * (int *) args;
665 if (ptid_get_pid (entry->id) != pid)
668 /* If we're detaching from a running inferior, make sure it is
669 stopped first, as PTRACE_DETACH will not work otherwise. */
672 int lwpid = lwpid_of (lwp);
674 stopping_threads = 1;
675 send_sigstop (&lwp->head);
677 /* If this detects a new thread through a clone event, the new
678 thread is appended to the end of the lwp list, so we'll
679 eventually detach from it. */
680 wait_for_sigstop (&lwp->head);
681 stopping_threads = 0;
683 /* If LWP exits while we're trying to stop it, there's nothing
685 lwp = find_lwp_pid (pid_to_ptid (lwpid));
690 /* Make sure the process isn't stopped at a breakpoint that's
692 check_removed_breakpoint (lwp);
694 /* If this process is stopped but is expecting a SIGSTOP, then make
695 sure we take care of that now. This isn't absolutely guaranteed
696 to collect the SIGSTOP, but is fairly likely to. */
697 if (lwp->stop_expected)
700 /* Clear stop_expected, so that the SIGSTOP will be reported. */
701 lwp->stop_expected = 0;
703 linux_resume_one_lwp (lwp, 0, 0, NULL);
704 linux_wait_for_event (lwp->head.id, &wstat, __WALL);
707 /* Flush any pending changes to the process's registers. */
708 regcache_invalidate_one ((struct inferior_list_entry *)
709 get_lwp_thread (lwp));
711 /* Finally, let it resume. */
712 ptrace (PTRACE_DETACH, lwpid_of (lwp), 0, 0);
719 any_thread_of (struct inferior_list_entry *entry, void *args)
723 if (ptid_get_pid (entry->id) == *pid_p)
730 linux_detach (int pid)
732 struct process_info *process;
734 process = find_process_pid (pid);
739 (struct thread_info *) find_inferior (&all_threads, any_thread_of, &pid);
741 delete_all_breakpoints ();
742 find_inferior (&all_threads, linux_detach_one_lwp, &pid);
743 linux_remove_process (process);
751 struct process_info *process;
753 process = find_process_pid (pid);
758 ret = my_waitpid (pid, &status, 0);
759 if (WIFEXITED (status) || WIFSIGNALED (status))
761 } while (ret != -1 || errno != ECHILD);
764 /* Return nonzero if the given thread is still alive. */
766 linux_thread_alive (ptid_t ptid)
768 struct lwp_info *lwp = find_lwp_pid (ptid);
770 /* We assume we always know if a thread exits. If a whole process
771 exited but we still haven't been able to report it to GDB, we'll
772 hold on to the last lwp of the dead process. */
779 /* Return nonzero if this process stopped at a breakpoint which
780 no longer appears to be inserted. Also adjust the PC
781 appropriately to resume where the breakpoint used to be. */
783 check_removed_breakpoint (struct lwp_info *event_child)
786 struct thread_info *saved_inferior;
788 if (event_child->pending_is_breakpoint == 0)
792 fprintf (stderr, "Checking for breakpoint in lwp %ld.\n",
793 lwpid_of (event_child));
795 saved_inferior = current_inferior;
796 current_inferior = get_lwp_thread (event_child);
798 stop_pc = get_stop_pc ();
800 /* If the PC has changed since we stopped, then we shouldn't do
801 anything. This happens if, for instance, GDB handled the
802 decr_pc_after_break subtraction itself. */
803 if (stop_pc != event_child->pending_stop_pc)
806 fprintf (stderr, "Ignoring, PC was changed. Old PC was 0x%08llx\n",
807 event_child->pending_stop_pc);
809 event_child->pending_is_breakpoint = 0;
810 current_inferior = saved_inferior;
814 /* If the breakpoint is still there, we will report hitting it. */
815 if ((*the_low_target.breakpoint_at) (stop_pc))
818 fprintf (stderr, "Ignoring, breakpoint is still present.\n");
819 current_inferior = saved_inferior;
824 fprintf (stderr, "Removed breakpoint.\n");
826 /* For decr_pc_after_break targets, here is where we perform the
827 decrement. We go immediately from this function to resuming,
828 and can not safely call get_stop_pc () again. */
829 if (the_low_target.set_pc != NULL)
832 fprintf (stderr, "Set pc to 0x%lx\n", (long) stop_pc);
833 (*the_low_target.set_pc) (stop_pc);
836 /* We consumed the pending SIGTRAP. */
837 event_child->pending_is_breakpoint = 0;
838 event_child->status_pending_p = 0;
839 event_child->status_pending = 0;
841 current_inferior = saved_inferior;
845 /* Return 1 if this lwp has an interesting status pending. This
846 function may silently resume an inferior lwp. */
848 status_pending_p (struct inferior_list_entry *entry, void *arg)
850 struct lwp_info *lwp = (struct lwp_info *) entry;
851 ptid_t ptid = * (ptid_t *) arg;
853 /* Check if we're only interested in events from a specific process
855 if (!ptid_equal (minus_one_ptid, ptid)
856 && ptid_get_pid (ptid) != ptid_get_pid (lwp->head.id))
859 if (lwp->status_pending_p && !lwp->suspended)
860 if (check_removed_breakpoint (lwp))
862 /* This thread was stopped at a breakpoint, and the breakpoint
863 is now gone. We were told to continue (or step...) all threads,
864 so GDB isn't trying to single-step past this breakpoint.
865 So instead of reporting the old SIGTRAP, pretend we got to
866 the breakpoint just after it was removed instead of just
867 before; resume the process. */
868 linux_resume_one_lwp (lwp, 0, 0, NULL);
872 return (lwp->status_pending_p && !lwp->suspended);
876 same_lwp (struct inferior_list_entry *entry, void *data)
878 ptid_t ptid = *(ptid_t *) data;
881 if (ptid_get_lwp (ptid) != 0)
882 lwp = ptid_get_lwp (ptid);
884 lwp = ptid_get_pid (ptid);
886 if (ptid_get_lwp (entry->id) == lwp)
893 find_lwp_pid (ptid_t ptid)
895 return (struct lwp_info*) find_inferior (&all_lwps, same_lwp, &ptid);
898 static struct lwp_info *
899 linux_wait_for_lwp (ptid_t ptid, int *wstatp, int options)
902 int to_wait_for = -1;
903 struct lwp_info *child = NULL;
906 fprintf (stderr, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid));
908 if (ptid_equal (ptid, minus_one_ptid))
909 to_wait_for = -1; /* any child */
911 to_wait_for = ptid_get_lwp (ptid); /* this lwp only */
917 ret = my_waitpid (to_wait_for, wstatp, options);
918 if (ret == 0 || (ret == -1 && errno == ECHILD && (options & WNOHANG)))
921 perror_with_name ("waitpid");
924 && (!WIFSTOPPED (*wstatp)
925 || (WSTOPSIG (*wstatp) != 32
926 && WSTOPSIG (*wstatp) != 33)))
927 fprintf (stderr, "Got an event from %d (%x)\n", ret, *wstatp);
929 child = find_lwp_pid (pid_to_ptid (ret));
931 /* If we didn't find a process, one of two things presumably happened:
932 - A process we started and then detached from has exited. Ignore it.
933 - A process we are controlling has forked and the new child's stop
934 was reported to us by the kernel. Save its PID. */
935 if (child == NULL && WIFSTOPPED (*wstatp))
937 add_pid_to_list (&stopped_pids, ret);
940 else if (child == NULL)
944 child->pending_is_breakpoint = 0;
946 child->last_status = *wstatp;
948 /* Architecture-specific setup after inferior is running.
949 This needs to happen after we have attached to the inferior
950 and it is stopped for the first time, but before we access
951 any inferior registers. */
954 the_low_target.arch_setup ();
955 #ifdef HAVE_LINUX_REGSETS
956 memset (disabled_regsets, 0, num_regsets);
962 && WIFSTOPPED (*wstatp)
963 && the_low_target.get_pc != NULL)
965 struct thread_info *saved_inferior = current_inferior;
968 current_inferior = (struct thread_info *)
969 find_inferior_id (&all_threads, child->head.id);
970 pc = (*the_low_target.get_pc) ();
971 fprintf (stderr, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc);
972 current_inferior = saved_inferior;
978 /* Wait for an event from child PID. If PID is -1, wait for any
979 child. Store the stop status through the status pointer WSTAT.
980 OPTIONS is passed to the waitpid call. Return 0 if no child stop
981 event was found and OPTIONS contains WNOHANG. Return the PID of
982 the stopped child otherwise. */
985 linux_wait_for_event_1 (ptid_t ptid, int *wstat, int options)
988 struct lwp_info *event_child = NULL;
990 struct lwp_info *requested_child = NULL;
992 /* Check for a lwp with a pending status. */
993 /* It is possible that the user changed the pending task's registers since
994 it stopped. We correctly handle the change of PC if we hit a breakpoint
995 (in check_removed_breakpoint); signals should be reported anyway. */
997 if (ptid_equal (ptid, minus_one_ptid)
998 || ptid_equal (pid_to_ptid (ptid_get_pid (ptid)), ptid))
1000 event_child = (struct lwp_info *)
1001 find_inferior (&all_lwps, status_pending_p, &ptid);
1002 if (debug_threads && event_child)
1003 fprintf (stderr, "Got a pending child %ld\n", lwpid_of (event_child));
1007 requested_child = find_lwp_pid (ptid);
1008 if (requested_child->status_pending_p
1009 && !check_removed_breakpoint (requested_child))
1010 event_child = requested_child;
1013 if (event_child != NULL)
1016 fprintf (stderr, "Got an event from pending child %ld (%04x)\n",
1017 lwpid_of (event_child), event_child->status_pending);
1018 *wstat = event_child->status_pending;
1019 event_child->status_pending_p = 0;
1020 event_child->status_pending = 0;
1021 current_inferior = get_lwp_thread (event_child);
1022 return lwpid_of (event_child);
1025 /* We only enter this loop if no process has a pending wait status. Thus
1026 any action taken in response to a wait status inside this loop is
1027 responding as soon as we detect the status, not after any pending
1031 event_child = linux_wait_for_lwp (ptid, wstat, options);
1033 if ((options & WNOHANG) && event_child == NULL)
1036 if (event_child == NULL)
1037 error ("event from unknown child");
1039 current_inferior = get_lwp_thread (event_child);
1041 /* Check for thread exit. */
1042 if (! WIFSTOPPED (*wstat))
1045 fprintf (stderr, "LWP %ld exiting\n", lwpid_of (event_child));
1047 /* If the last thread is exiting, just return. */
1048 if (last_thread_of_process_p (current_inferior))
1051 fprintf (stderr, "LWP %ld is last lwp of process\n",
1052 lwpid_of (event_child));
1053 return lwpid_of (event_child);
1056 delete_lwp (event_child);
1060 current_inferior = (struct thread_info *) all_threads.head;
1062 fprintf (stderr, "Current inferior is now %ld\n",
1063 lwpid_of (get_thread_lwp (current_inferior)));
1067 current_inferior = NULL;
1069 fprintf (stderr, "Current inferior is now <NULL>\n");
1072 /* If we were waiting for this particular child to do something...
1073 well, it did something. */
1074 if (requested_child != NULL)
1075 return lwpid_of (event_child);
1077 /* Wait for a more interesting event. */
1081 if (event_child->must_set_ptrace_flags)
1083 ptrace (PTRACE_SETOPTIONS, lwpid_of (event_child),
1084 0, PTRACE_O_TRACECLONE);
1085 event_child->must_set_ptrace_flags = 0;
1088 if (WIFSTOPPED (*wstat)
1089 && WSTOPSIG (*wstat) == SIGSTOP
1090 && event_child->stop_expected)
1093 fprintf (stderr, "Expected stop.\n");
1094 event_child->stop_expected = 0;
1095 linux_resume_one_lwp (event_child, event_child->stepping, 0, NULL);
1099 if (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) == SIGTRAP
1100 && *wstat >> 16 != 0)
1102 handle_extended_wait (event_child, *wstat);
1106 /* If GDB is not interested in this signal, don't stop other
1107 threads, and don't report it to GDB. Just resume the
1108 inferior right away. We do this for threading-related
1109 signals as well as any that GDB specifically requested we
1110 ignore. But never ignore SIGSTOP if we sent it ourselves,
1111 and do not ignore signals when stepping - they may require
1112 special handling to skip the signal handler. */
1113 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
1115 if (WIFSTOPPED (*wstat)
1116 && !event_child->stepping
1118 #ifdef USE_THREAD_DB
1119 (current_process ()->private->thread_db_active
1120 && (WSTOPSIG (*wstat) == __SIGRTMIN
1121 || WSTOPSIG (*wstat) == __SIGRTMIN + 1))
1124 (pass_signals[target_signal_from_host (WSTOPSIG (*wstat))]
1125 && (WSTOPSIG (*wstat) != SIGSTOP || !stopping_threads))))
1127 siginfo_t info, *info_p;
1130 fprintf (stderr, "Ignored signal %d for LWP %ld.\n",
1131 WSTOPSIG (*wstat), lwpid_of (event_child));
1133 if (ptrace (PTRACE_GETSIGINFO, lwpid_of (event_child), 0, &info) == 0)
1137 linux_resume_one_lwp (event_child,
1138 event_child->stepping,
1139 WSTOPSIG (*wstat), info_p);
1143 /* If this event was not handled above, and is not a SIGTRAP, report
1145 if (!WIFSTOPPED (*wstat) || WSTOPSIG (*wstat) != SIGTRAP)
1146 return lwpid_of (event_child);
1148 /* If this target does not support breakpoints, we simply report the
1149 SIGTRAP; it's of no concern to us. */
1150 if (the_low_target.get_pc == NULL)
1151 return lwpid_of (event_child);
1153 stop_pc = get_stop_pc ();
1155 /* bp_reinsert will only be set if we were single-stepping.
1156 Notice that we will resume the process after hitting
1157 a gdbserver breakpoint; single-stepping to/over one
1158 is not supported (yet). */
1159 if (event_child->bp_reinsert != 0)
1162 fprintf (stderr, "Reinserted breakpoint.\n");
1163 reinsert_breakpoint (event_child->bp_reinsert);
1164 event_child->bp_reinsert = 0;
1166 /* Clear the single-stepping flag and SIGTRAP as we resume. */
1167 linux_resume_one_lwp (event_child, 0, 0, NULL);
1171 bp_status = check_breakpoints (stop_pc);
1176 fprintf (stderr, "Hit a gdbserver breakpoint.\n");
1178 /* We hit one of our own breakpoints. We mark it as a pending
1179 breakpoint, so that check_removed_breakpoint () will do the PC
1180 adjustment for us at the appropriate time. */
1181 event_child->pending_is_breakpoint = 1;
1182 event_child->pending_stop_pc = stop_pc;
1184 /* We may need to put the breakpoint back. We continue in the event
1185 loop instead of simply replacing the breakpoint right away,
1186 in order to not lose signals sent to the thread that hit the
1187 breakpoint. Unfortunately this increases the window where another
1188 thread could sneak past the removed breakpoint. For the current
1189 use of server-side breakpoints (thread creation) this is
1190 acceptable; but it needs to be considered before this breakpoint
1191 mechanism can be used in more general ways. For some breakpoints
1192 it may be necessary to stop all other threads, but that should
1193 be avoided where possible.
1195 If breakpoint_reinsert_addr is NULL, that means that we can
1196 use PTRACE_SINGLESTEP on this platform. Uninsert the breakpoint,
1197 mark it for reinsertion, and single-step.
1199 Otherwise, call the target function to figure out where we need
1200 our temporary breakpoint, create it, and continue executing this
1203 /* NOTE: we're lifting breakpoints in non-stop mode. This
1204 is currently only used for thread event breakpoints, so
1205 it isn't that bad as long as we have PTRACE_EVENT_CLONE
1208 /* No need to reinsert. */
1209 linux_resume_one_lwp (event_child, 0, 0, NULL);
1210 else if (the_low_target.breakpoint_reinsert_addr == NULL)
1212 event_child->bp_reinsert = stop_pc;
1213 uninsert_breakpoint (stop_pc);
1214 linux_resume_one_lwp (event_child, 1, 0, NULL);
1218 reinsert_breakpoint_by_bp
1219 (stop_pc, (*the_low_target.breakpoint_reinsert_addr) ());
1220 linux_resume_one_lwp (event_child, 0, 0, NULL);
1227 fprintf (stderr, "Hit a non-gdbserver breakpoint.\n");
1229 /* If we were single-stepping, we definitely want to report the
1230 SIGTRAP. Although the single-step operation has completed,
1231 do not clear clear the stepping flag yet; we need to check it
1232 in wait_for_sigstop. */
1233 if (event_child->stepping)
1234 return lwpid_of (event_child);
1236 /* A SIGTRAP that we can't explain. It may have been a breakpoint.
1237 Check if it is a breakpoint, and if so mark the process information
1238 accordingly. This will handle both the necessary fiddling with the
1239 PC on decr_pc_after_break targets and suppressing extra threads
1240 hitting a breakpoint if two hit it at once and then GDB removes it
1241 after the first is reported. Arguably it would be better to report
1242 multiple threads hitting breakpoints simultaneously, but the current
1243 remote protocol does not allow this. */
1244 if ((*the_low_target.breakpoint_at) (stop_pc))
1246 event_child->pending_is_breakpoint = 1;
1247 event_child->pending_stop_pc = stop_pc;
1250 return lwpid_of (event_child);
1258 linux_wait_for_event (ptid_t ptid, int *wstat, int options)
1262 if (ptid_is_pid (ptid))
1264 /* A request to wait for a specific tgid. This is not possible
1265 with waitpid, so instead, we wait for any child, and leave
1266 children we're not interested in right now with a pending
1267 status to report later. */
1268 wait_ptid = minus_one_ptid;
1277 event_pid = linux_wait_for_event_1 (wait_ptid, wstat, options);
1280 && ptid_is_pid (ptid) && ptid_get_pid (ptid) != event_pid)
1282 struct lwp_info *event_child = find_lwp_pid (pid_to_ptid (event_pid));
1284 if (! WIFSTOPPED (*wstat))
1285 mark_lwp_dead (event_child, *wstat);
1288 event_child->status_pending_p = 1;
1289 event_child->status_pending = *wstat;
1297 /* Wait for process, returns status. */
1300 linux_wait_1 (ptid_t ptid,
1301 struct target_waitstatus *ourstatus, int target_options)
1304 struct thread_info *thread = NULL;
1305 struct lwp_info *lwp = NULL;
1309 /* Translate generic target options into linux options. */
1311 if (target_options & TARGET_WNOHANG)
1315 ourstatus->kind = TARGET_WAITKIND_IGNORE;
1317 /* If we were only supposed to resume one thread, only wait for
1318 that thread - if it's still alive. If it died, however - which
1319 can happen if we're coming from the thread death case below -
1320 then we need to make sure we restart the other threads. We could
1321 pick a thread at random or restart all; restarting all is less
1324 && !ptid_equal (cont_thread, null_ptid)
1325 && !ptid_equal (cont_thread, minus_one_ptid))
1327 thread = (struct thread_info *) find_inferior_id (&all_threads,
1330 /* No stepping, no signal - unless one is pending already, of course. */
1333 struct thread_resume resume_info;
1334 resume_info.thread = minus_one_ptid;
1335 resume_info.kind = resume_continue;
1336 resume_info.sig = 0;
1337 linux_resume (&resume_info, 1);
1343 pid = linux_wait_for_event (ptid, &w, options);
1344 if (pid == 0) /* only if TARGET_WNOHANG */
1347 lwp = get_thread_lwp (current_inferior);
1349 /* If we are waiting for a particular child, and it exited,
1350 linux_wait_for_event will return its exit status. Similarly if
1351 the last child exited. If this is not the last child, however,
1352 do not report it as exited until there is a 'thread exited' response
1353 available in the remote protocol. Instead, just wait for another event.
1354 This should be safe, because if the thread crashed we will already
1355 have reported the termination signal to GDB; that should stop any
1356 in-progress stepping operations, etc.
1358 Report the exit status of the last thread to exit. This matches
1359 LinuxThreads' behavior. */
1361 if (last_thread_of_process_p (current_inferior))
1363 if (WIFEXITED (w) || WIFSIGNALED (w))
1365 int pid = pid_of (lwp);
1366 struct process_info *process = find_process_pid (pid);
1369 linux_remove_process (process);
1371 current_inferior = NULL;
1375 ourstatus->kind = TARGET_WAITKIND_EXITED;
1376 ourstatus->value.integer = WEXITSTATUS (w);
1379 fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
1383 ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
1384 ourstatus->value.sig = target_signal_from_host (WTERMSIG (w));
1387 fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
1391 return pid_to_ptid (pid);
1396 if (!WIFSTOPPED (w))
1400 /* In all-stop, stop all threads. Be careful to only do this if
1401 we're about to report an event to GDB. */
1405 ourstatus->kind = TARGET_WAITKIND_STOPPED;
1407 if (lwp->suspended && WSTOPSIG (w) == SIGSTOP)
1409 /* A thread that has been requested to stop by GDB with vCont;t,
1410 and it stopped cleanly, so report as SIG0. The use of
1411 SIGSTOP is an implementation detail. */
1412 ourstatus->value.sig = TARGET_SIGNAL_0;
1414 else if (lwp->suspended && WSTOPSIG (w) != SIGSTOP)
1416 /* A thread that has been requested to stop by GDB with vCont;t,
1417 but, it stopped for other reasons. Set stop_expected so the
1418 pending SIGSTOP is ignored and the LWP is resumed. */
1419 lwp->stop_expected = 1;
1420 ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
1424 ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
1428 fprintf (stderr, "linux_wait ret = %s, %d, %d\n",
1429 target_pid_to_str (lwp->head.id),
1431 ourstatus->value.sig);
1433 return lwp->head.id;
1436 /* Get rid of any pending event in the pipe. */
1438 async_file_flush (void)
1444 ret = read (linux_event_pipe[0], &buf, 1);
1445 while (ret >= 0 || (ret == -1 && errno == EINTR));
1448 /* Put something in the pipe, so the event loop wakes up. */
1450 async_file_mark (void)
1454 async_file_flush ();
1457 ret = write (linux_event_pipe[1], "+", 1);
1458 while (ret == 0 || (ret == -1 && errno == EINTR));
1460 /* Ignore EAGAIN. If the pipe is full, the event loop will already
1461 be awakened anyway. */
1465 linux_wait (ptid_t ptid,
1466 struct target_waitstatus *ourstatus, int target_options)
1471 fprintf (stderr, "linux_wait: [%s]\n", target_pid_to_str (ptid));
1473 /* Flush the async file first. */
1474 if (target_is_async_p ())
1475 async_file_flush ();
1477 event_ptid = linux_wait_1 (ptid, ourstatus, target_options);
1479 /* If at least one stop was reported, there may be more. A single
1480 SIGCHLD can signal more than one child stop. */
1481 if (target_is_async_p ()
1482 && (target_options & TARGET_WNOHANG) != 0
1483 && !ptid_equal (event_ptid, null_ptid))
1489 /* Send a signal to an LWP. For LinuxThreads, kill is enough; however, if
1490 thread groups are in use, we need to use tkill. */
1493 kill_lwp (unsigned long lwpid, int signo)
1495 static int tkill_failed;
1502 int ret = syscall (SYS_tkill, lwpid, signo);
1503 if (errno != ENOSYS)
1510 return kill (lwpid, signo);
1514 send_sigstop (struct inferior_list_entry *entry)
1516 struct lwp_info *lwp = (struct lwp_info *) entry;
1522 pid = lwpid_of (lwp);
1524 /* If we already have a pending stop signal for this process, don't
1526 if (lwp->stop_expected)
1529 fprintf (stderr, "Have pending sigstop for lwp %d\n", pid);
1531 /* We clear the stop_expected flag so that wait_for_sigstop
1532 will receive the SIGSTOP event (instead of silently resuming and
1533 waiting again). It'll be reset below. */
1534 lwp->stop_expected = 0;
1539 fprintf (stderr, "Sending sigstop to lwp %d\n", pid);
1541 kill_lwp (pid, SIGSTOP);
1545 mark_lwp_dead (struct lwp_info *lwp, int wstat)
1547 /* It's dead, really. */
1550 /* Store the exit status for later. */
1551 lwp->status_pending_p = 1;
1552 lwp->status_pending = wstat;
1554 /* So that check_removed_breakpoint doesn't try to figure out if
1555 this is stopped at a breakpoint. */
1556 lwp->pending_is_breakpoint = 0;
1558 /* Prevent trying to stop it. */
1561 /* No further stops are expected from a dead lwp. */
1562 lwp->stop_expected = 0;
1566 wait_for_sigstop (struct inferior_list_entry *entry)
1568 struct lwp_info *lwp = (struct lwp_info *) entry;
1569 struct thread_info *saved_inferior;
1577 saved_inferior = current_inferior;
1578 if (saved_inferior != NULL)
1579 saved_tid = ((struct inferior_list_entry *) saved_inferior)->id;
1581 saved_tid = null_ptid; /* avoid bogus unused warning */
1583 ptid = lwp->head.id;
1585 linux_wait_for_event (ptid, &wstat, __WALL);
1587 /* If we stopped with a non-SIGSTOP signal, save it for later
1588 and record the pending SIGSTOP. If the process exited, just
1590 if (WIFSTOPPED (wstat)
1591 && WSTOPSIG (wstat) != SIGSTOP)
1594 fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n",
1595 lwpid_of (lwp), wstat);
1597 /* Do not leave a pending single-step finish to be reported to
1598 the client. The client will give us a new action for this
1599 thread, possibly a continue request --- otherwise, the client
1600 would consider this pending SIGTRAP reported later a spurious
1602 if (WSTOPSIG (wstat) == SIGTRAP
1604 && !linux_stopped_by_watchpoint ())
1607 fprintf (stderr, " single-step SIGTRAP ignored\n");
1611 lwp->status_pending_p = 1;
1612 lwp->status_pending = wstat;
1614 lwp->stop_expected = 1;
1616 else if (!WIFSTOPPED (wstat))
1619 fprintf (stderr, "Process %ld exited while stopping LWPs\n",
1622 /* Leave this status pending for the next time we're able to
1623 report it. In the mean time, we'll report this lwp as dead
1624 to GDB, so GDB doesn't try to read registers and memory from
1626 mark_lwp_dead (lwp, wstat);
1629 if (saved_inferior == NULL || linux_thread_alive (saved_tid))
1630 current_inferior = saved_inferior;
1634 fprintf (stderr, "Previously current thread died.\n");
1638 /* We can't change the current inferior behind GDB's back,
1639 otherwise, a subsequent command may apply to the wrong
1641 current_inferior = NULL;
1645 /* Set a valid thread as current. */
1646 set_desired_inferior (0);
1652 stop_all_lwps (void)
1654 stopping_threads = 1;
1655 for_each_inferior (&all_lwps, send_sigstop);
1656 for_each_inferior (&all_lwps, wait_for_sigstop);
1657 stopping_threads = 0;
1660 /* Resume execution of the inferior process.
1661 If STEP is nonzero, single-step it.
1662 If SIGNAL is nonzero, give it that signal. */
1665 linux_resume_one_lwp (struct lwp_info *lwp,
1666 int step, int signal, siginfo_t *info)
1668 struct thread_info *saved_inferior;
1670 if (lwp->stopped == 0)
1673 /* If we have pending signals or status, and a new signal, enqueue the
1674 signal. Also enqueue the signal if we are waiting to reinsert a
1675 breakpoint; it will be picked up again below. */
1677 && (lwp->status_pending_p || lwp->pending_signals != NULL
1678 || lwp->bp_reinsert != 0))
1680 struct pending_signals *p_sig;
1681 p_sig = xmalloc (sizeof (*p_sig));
1682 p_sig->prev = lwp->pending_signals;
1683 p_sig->signal = signal;
1685 memset (&p_sig->info, 0, sizeof (siginfo_t));
1687 memcpy (&p_sig->info, info, sizeof (siginfo_t));
1688 lwp->pending_signals = p_sig;
1691 if (lwp->status_pending_p && !check_removed_breakpoint (lwp))
1694 saved_inferior = current_inferior;
1695 current_inferior = get_lwp_thread (lwp);
1698 fprintf (stderr, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
1699 lwpid_of (lwp), step ? "step" : "continue", signal,
1700 lwp->stop_expected ? "expected" : "not expected");
1702 /* This bit needs some thinking about. If we get a signal that
1703 we must report while a single-step reinsert is still pending,
1704 we often end up resuming the thread. It might be better to
1705 (ew) allow a stack of pending events; then we could be sure that
1706 the reinsert happened right away and not lose any signals.
1708 Making this stack would also shrink the window in which breakpoints are
1709 uninserted (see comment in linux_wait_for_lwp) but not enough for
1710 complete correctness, so it won't solve that problem. It may be
1711 worthwhile just to solve this one, however. */
1712 if (lwp->bp_reinsert != 0)
1715 fprintf (stderr, " pending reinsert at %08lx", (long)lwp->bp_reinsert);
1717 fprintf (stderr, "BAD - reinserting but not stepping.\n");
1720 /* Postpone any pending signal. It was enqueued above. */
1724 check_removed_breakpoint (lwp);
1726 if (debug_threads && the_low_target.get_pc != NULL)
1728 CORE_ADDR pc = (*the_low_target.get_pc) ();
1729 fprintf (stderr, " resuming from pc 0x%lx\n", (long) pc);
1732 /* If we have pending signals, consume one unless we are trying to reinsert
1734 if (lwp->pending_signals != NULL && lwp->bp_reinsert == 0)
1736 struct pending_signals **p_sig;
1738 p_sig = &lwp->pending_signals;
1739 while ((*p_sig)->prev != NULL)
1740 p_sig = &(*p_sig)->prev;
1742 signal = (*p_sig)->signal;
1743 if ((*p_sig)->info.si_signo != 0)
1744 ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &(*p_sig)->info);
1750 if (the_low_target.prepare_to_resume != NULL)
1751 the_low_target.prepare_to_resume (lwp);
1753 regcache_invalidate_one ((struct inferior_list_entry *)
1754 get_lwp_thread (lwp));
1757 lwp->stepping = step;
1758 ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (lwp), 0, signal);
1760 current_inferior = saved_inferior;
1763 /* ESRCH from ptrace either means that the thread was already
1764 running (an error) or that it is gone (a race condition). If
1765 it's gone, we will get a notification the next time we wait,
1766 so we can ignore the error. We could differentiate these
1767 two, but it's tricky without waiting; the thread still exists
1768 as a zombie, so sending it signal 0 would succeed. So just
1773 perror_with_name ("ptrace");
1777 struct thread_resume_array
1779 struct thread_resume *resume;
1783 /* This function is called once per thread. We look up the thread
1784 in RESUME_PTR, and mark the thread with a pointer to the appropriate
1787 This algorithm is O(threads * resume elements), but resume elements
1788 is small (and will remain small at least until GDB supports thread
1791 linux_set_resume_request (struct inferior_list_entry *entry, void *arg)
1793 struct lwp_info *lwp;
1794 struct thread_info *thread;
1796 struct thread_resume_array *r;
1798 thread = (struct thread_info *) entry;
1799 lwp = get_thread_lwp (thread);
1802 for (ndx = 0; ndx < r->n; ndx++)
1804 ptid_t ptid = r->resume[ndx].thread;
1805 if (ptid_equal (ptid, minus_one_ptid)
1806 || ptid_equal (ptid, entry->id)
1807 || (ptid_is_pid (ptid)
1808 && (ptid_get_pid (ptid) == pid_of (lwp)))
1809 || (ptid_get_lwp (ptid) == -1
1810 && (ptid_get_pid (ptid) == pid_of (lwp))))
1812 lwp->resume = &r->resume[ndx];
1817 /* No resume action for this thread. */
1824 /* Set *FLAG_P if this lwp has an interesting status pending. */
1826 resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p)
1828 struct lwp_info *lwp = (struct lwp_info *) entry;
1830 /* LWPs which will not be resumed are not interesting, because
1831 we might not wait for them next time through linux_wait. */
1832 if (lwp->resume == NULL)
1835 /* If this thread has a removed breakpoint, we won't have any
1836 events to report later, so check now. check_removed_breakpoint
1837 may clear status_pending_p. We avoid calling check_removed_breakpoint
1838 for any thread that we are not otherwise going to resume - this
1839 lets us preserve stopped status when two threads hit a breakpoint.
1840 GDB removes the breakpoint to single-step a particular thread
1841 past it, then re-inserts it and resumes all threads. We want
1842 to report the second thread without resuming it in the interim. */
1843 if (lwp->status_pending_p)
1844 check_removed_breakpoint (lwp);
1846 if (lwp->status_pending_p)
1847 * (int *) flag_p = 1;
1852 /* This function is called once per thread. We check the thread's resume
1853 request, which will tell us whether to resume, step, or leave the thread
1854 stopped; and what signal, if any, it should be sent.
1856 For threads which we aren't explicitly told otherwise, we preserve
1857 the stepping flag; this is used for stepping over gdbserver-placed
1860 If pending_flags was set in any thread, we queue any needed
1861 signals, since we won't actually resume. We already have a pending
1862 event to report, so we don't need to preserve any step requests;
1863 they should be re-issued if necessary. */
1866 linux_resume_one_thread (struct inferior_list_entry *entry, void *arg)
1868 struct lwp_info *lwp;
1869 struct thread_info *thread;
1871 int pending_flag = * (int *) arg;
1873 thread = (struct thread_info *) entry;
1874 lwp = get_thread_lwp (thread);
1876 if (lwp->resume == NULL)
1879 if (lwp->resume->kind == resume_stop)
1882 fprintf (stderr, "suspending LWP %ld\n", lwpid_of (lwp));
1887 fprintf (stderr, "running -> suspending LWP %ld\n", lwpid_of (lwp));
1890 send_sigstop (&lwp->head);
1897 fprintf (stderr, "already stopped/suspended LWP %ld\n",
1900 fprintf (stderr, "already stopped/not suspended LWP %ld\n",
1904 /* Make sure we leave the LWP suspended, so we don't try to
1905 resume it without GDB telling us to. FIXME: The LWP may
1906 have been stopped in an internal event that was not meant
1907 to be notified back to GDB (e.g., gdbserver breakpoint),
1908 so we should be reporting a stop event in that case
1913 /* For stop requests, we're done. */
1920 /* If this thread which is about to be resumed has a pending status,
1921 then don't resume any threads - we can just report the pending
1922 status. Make sure to queue any signals that would otherwise be
1923 sent. In all-stop mode, we do this decision based on if *any*
1924 thread has a pending status. */
1926 resume_status_pending_p (&lwp->head, &pending_flag);
1931 fprintf (stderr, "resuming LWP %ld\n", lwpid_of (lwp));
1933 if (ptid_equal (lwp->resume->thread, minus_one_ptid)
1935 && lwp->pending_is_breakpoint)
1938 step = (lwp->resume->kind == resume_step);
1940 linux_resume_one_lwp (lwp, step, lwp->resume->sig, NULL);
1945 fprintf (stderr, "leaving LWP %ld stopped\n", lwpid_of (lwp));
1947 /* If we have a new signal, enqueue the signal. */
1948 if (lwp->resume->sig != 0)
1950 struct pending_signals *p_sig;
1951 p_sig = xmalloc (sizeof (*p_sig));
1952 p_sig->prev = lwp->pending_signals;
1953 p_sig->signal = lwp->resume->sig;
1954 memset (&p_sig->info, 0, sizeof (siginfo_t));
1956 /* If this is the same signal we were previously stopped by,
1957 make sure to queue its siginfo. We can ignore the return
1958 value of ptrace; if it fails, we'll skip
1959 PTRACE_SETSIGINFO. */
1960 if (WIFSTOPPED (lwp->last_status)
1961 && WSTOPSIG (lwp->last_status) == lwp->resume->sig)
1962 ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info);
1964 lwp->pending_signals = p_sig;
1973 linux_resume (struct thread_resume *resume_info, size_t n)
1976 struct thread_resume_array array = { resume_info, n };
1978 find_inferior (&all_threads, linux_set_resume_request, &array);
1980 /* If there is a thread which would otherwise be resumed, which
1981 has a pending status, then don't resume any threads - we can just
1982 report the pending status. Make sure to queue any signals
1983 that would otherwise be sent. In non-stop mode, we'll apply this
1984 logic to each thread individually. */
1987 find_inferior (&all_lwps, resume_status_pending_p, &pending_flag);
1992 fprintf (stderr, "Not resuming, pending status\n");
1994 fprintf (stderr, "Resuming, no pending status\n");
1997 find_inferior (&all_threads, linux_resume_one_thread, &pending_flag);
2000 #ifdef HAVE_LINUX_USRREGS
2003 register_addr (int regnum)
2007 if (regnum < 0 || regnum >= the_low_target.num_regs)
2008 error ("Invalid register number %d.", regnum);
2010 addr = the_low_target.regmap[regnum];
2015 /* Fetch one register. */
2017 fetch_register (int regno)
2024 if (regno >= the_low_target.num_regs)
2026 if ((*the_low_target.cannot_fetch_register) (regno))
2029 regaddr = register_addr (regno);
2033 pid = lwpid_of (get_thread_lwp (current_inferior));
2034 size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
2035 & - sizeof (PTRACE_XFER_TYPE));
2036 buf = alloca (size);
2037 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
2040 *(PTRACE_XFER_TYPE *) (buf + i) =
2041 ptrace (PTRACE_PEEKUSER, pid, (PTRACE_ARG3_TYPE) regaddr, 0);
2042 regaddr += sizeof (PTRACE_XFER_TYPE);
2045 /* Warning, not error, in case we are attached; sometimes the
2046 kernel doesn't let us at the registers. */
2047 char *err = strerror (errno);
2048 char *msg = alloca (strlen (err) + 128);
2049 sprintf (msg, "reading register %d: %s", regno, err);
2055 if (the_low_target.supply_ptrace_register)
2056 the_low_target.supply_ptrace_register (regno, buf);
2058 supply_register (regno, buf);
2063 /* Fetch all registers, or just one, from the child process. */
2065 usr_fetch_inferior_registers (int regno)
2068 for (regno = 0; regno < the_low_target.num_regs; regno++)
2069 fetch_register (regno);
2071 fetch_register (regno);
2074 /* Store our register values back into the inferior.
2075 If REGNO is -1, do this for all registers.
2076 Otherwise, REGNO specifies which register (so we can save time). */
2078 usr_store_inferior_registers (int regno)
2087 if (regno >= the_low_target.num_regs)
2090 if ((*the_low_target.cannot_store_register) (regno) == 1)
2093 regaddr = register_addr (regno);
2097 size = (register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
2098 & - sizeof (PTRACE_XFER_TYPE);
2099 buf = alloca (size);
2100 memset (buf, 0, size);
2102 if (the_low_target.collect_ptrace_register)
2103 the_low_target.collect_ptrace_register (regno, buf);
2105 collect_register (regno, buf);
2107 pid = lwpid_of (get_thread_lwp (current_inferior));
2108 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
2111 ptrace (PTRACE_POKEUSER, pid, (PTRACE_ARG3_TYPE) regaddr,
2112 *(PTRACE_XFER_TYPE *) (buf + i));
2115 /* At this point, ESRCH should mean the process is
2116 already gone, in which case we simply ignore attempts
2117 to change its registers. See also the related
2118 comment in linux_resume_one_lwp. */
2122 if ((*the_low_target.cannot_store_register) (regno) == 0)
2124 char *err = strerror (errno);
2125 char *msg = alloca (strlen (err) + 128);
2126 sprintf (msg, "writing register %d: %s",
2132 regaddr += sizeof (PTRACE_XFER_TYPE);
2136 for (regno = 0; regno < the_low_target.num_regs; regno++)
2137 usr_store_inferior_registers (regno);
2139 #endif /* HAVE_LINUX_USRREGS */
2143 #ifdef HAVE_LINUX_REGSETS
2146 regsets_fetch_inferior_registers ()
2148 struct regset_info *regset;
2149 int saw_general_regs = 0;
2152 regset = target_regsets;
2154 pid = lwpid_of (get_thread_lwp (current_inferior));
2155 while (regset->size >= 0)
2160 if (regset->size == 0 || disabled_regsets[regset - target_regsets])
2166 buf = xmalloc (regset->size);
2168 res = ptrace (regset->get_request, pid, 0, buf);
2170 res = ptrace (regset->get_request, pid, buf, 0);
2176 /* If we get EIO on a regset, do not try it again for
2178 disabled_regsets[regset - target_regsets] = 1;
2185 sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d",
2190 else if (regset->type == GENERAL_REGS)
2191 saw_general_regs = 1;
2192 regset->store_function (buf);
2196 if (saw_general_regs)
2203 regsets_store_inferior_registers ()
2205 struct regset_info *regset;
2206 int saw_general_regs = 0;
2209 regset = target_regsets;
2211 pid = lwpid_of (get_thread_lwp (current_inferior));
2212 while (regset->size >= 0)
2217 if (regset->size == 0 || disabled_regsets[regset - target_regsets])
2223 buf = xmalloc (regset->size);
2225 /* First fill the buffer with the current register set contents,
2226 in case there are any items in the kernel's regset that are
2227 not in gdbserver's regcache. */
2229 res = ptrace (regset->get_request, pid, 0, buf);
2231 res = ptrace (regset->get_request, pid, buf, 0);
2236 /* Then overlay our cached registers on that. */
2237 regset->fill_function (buf);
2239 /* Only now do we write the register set. */
2241 res = ptrace (regset->set_request, pid, 0, buf);
2243 res = ptrace (regset->set_request, pid, buf, 0);
2251 /* If we get EIO on a regset, do not try it again for
2253 disabled_regsets[regset - target_regsets] = 1;
2257 else if (errno == ESRCH)
2259 /* At this point, ESRCH should mean the process is
2260 already gone, in which case we simply ignore attempts
2261 to change its registers. See also the related
2262 comment in linux_resume_one_lwp. */
2268 perror ("Warning: ptrace(regsets_store_inferior_registers)");
2271 else if (regset->type == GENERAL_REGS)
2272 saw_general_regs = 1;
2276 if (saw_general_regs)
2283 #endif /* HAVE_LINUX_REGSETS */
2287 linux_fetch_registers (int regno)
2289 #ifdef HAVE_LINUX_REGSETS
2290 if (regsets_fetch_inferior_registers () == 0)
2293 #ifdef HAVE_LINUX_USRREGS
2294 usr_fetch_inferior_registers (regno);
2299 linux_store_registers (int regno)
2301 #ifdef HAVE_LINUX_REGSETS
2302 if (regsets_store_inferior_registers () == 0)
2305 #ifdef HAVE_LINUX_USRREGS
2306 usr_store_inferior_registers (regno);
2311 /* Copy LEN bytes from inferior's memory starting at MEMADDR
2312 to debugger memory starting at MYADDR. */
2315 linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
2318 /* Round starting address down to longword boundary. */
2319 register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
2320 /* Round ending address up; get number of longwords that makes. */
2322 = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
2323 / sizeof (PTRACE_XFER_TYPE);
2324 /* Allocate buffer of that many longwords. */
2325 register PTRACE_XFER_TYPE *buffer
2326 = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
2329 int pid = lwpid_of (get_thread_lwp (current_inferior));
2331 /* Try using /proc. Don't bother for one word. */
2332 if (len >= 3 * sizeof (long))
2334 /* We could keep this file open and cache it - possibly one per
2335 thread. That requires some juggling, but is even faster. */
2336 sprintf (filename, "/proc/%d/mem", pid);
2337 fd = open (filename, O_RDONLY | O_LARGEFILE);
2341 /* If pread64 is available, use it. It's faster if the kernel
2342 supports it (only one syscall), and it's 64-bit safe even on
2343 32-bit platforms (for instance, SPARC debugging a SPARC64
2346 if (pread64 (fd, myaddr, len, memaddr) != len)
2348 if (lseek (fd, memaddr, SEEK_SET) == -1 || read (fd, memaddr, len) != len)
2360 /* Read all the longwords */
2361 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
2364 buffer[i] = ptrace (PTRACE_PEEKTEXT, pid, (PTRACE_ARG3_TYPE) addr, 0);
2369 /* Copy appropriate bytes out of the buffer. */
2371 (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
2377 /* Copy LEN bytes of data from debugger memory at MYADDR
2378 to inferior's memory at MEMADDR.
2379 On failure (cannot write the inferior)
2380 returns the value of errno. */
2383 linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
2386 /* Round starting address down to longword boundary. */
2387 register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
2388 /* Round ending address up; get number of longwords that makes. */
2390 = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) / sizeof (PTRACE_XFER_TYPE);
2391 /* Allocate buffer of that many longwords. */
2392 register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
2393 int pid = lwpid_of (get_thread_lwp (current_inferior));
2397 fprintf (stderr, "Writing %02x to %08lx\n", (unsigned)myaddr[0], (long)memaddr);
2400 /* Fill start and end extra bytes of buffer with existing memory data. */
2402 buffer[0] = ptrace (PTRACE_PEEKTEXT, pid, (PTRACE_ARG3_TYPE) addr, 0);
2407 = ptrace (PTRACE_PEEKTEXT, pid,
2408 (PTRACE_ARG3_TYPE) (addr + (count - 1)
2409 * sizeof (PTRACE_XFER_TYPE)),
2413 /* Copy data to be written over corresponding part of buffer */
2415 memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), myaddr, len);
2417 /* Write the entire buffer. */
2419 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
2422 ptrace (PTRACE_POKETEXT, pid, (PTRACE_ARG3_TYPE) addr, buffer[i]);
2430 static int linux_supports_tracefork_flag;
2432 /* Helper functions for linux_test_for_tracefork, called via clone (). */
2435 linux_tracefork_grandchild (void *arg)
2440 #define STACK_SIZE 4096
2443 linux_tracefork_child (void *arg)
2445 ptrace (PTRACE_TRACEME, 0, 0, 0);
2446 kill (getpid (), SIGSTOP);
2448 __clone2 (linux_tracefork_grandchild, arg, STACK_SIZE,
2449 CLONE_VM | SIGCHLD, NULL);
2451 clone (linux_tracefork_grandchild, arg + STACK_SIZE,
2452 CLONE_VM | SIGCHLD, NULL);
2457 /* Wrapper function for waitpid which handles EINTR, and emulates
2458 __WALL for systems where that is not available. */
2461 my_waitpid (int pid, int *status, int flags)
2466 fprintf (stderr, "my_waitpid (%d, 0x%x)\n", pid, flags);
2470 sigset_t block_mask, org_mask, wake_mask;
2473 wnohang = (flags & WNOHANG) != 0;
2474 flags &= ~(__WALL | __WCLONE);
2477 /* Block all signals while here. This avoids knowing about
2478 LinuxThread's signals. */
2479 sigfillset (&block_mask);
2480 sigprocmask (SIG_BLOCK, &block_mask, &org_mask);
2482 /* ... except during the sigsuspend below. */
2483 sigemptyset (&wake_mask);
2487 /* Since all signals are blocked, there's no need to check
2489 ret = waitpid (pid, status, flags);
2492 if (ret == -1 && out_errno != ECHILD)
2497 if (flags & __WCLONE)
2499 /* We've tried both flavors now. If WNOHANG is set,
2500 there's nothing else to do, just bail out. */
2505 fprintf (stderr, "blocking\n");
2507 /* Block waiting for signals. */
2508 sigsuspend (&wake_mask);
2514 sigprocmask (SIG_SETMASK, &org_mask, NULL);
2519 ret = waitpid (pid, status, flags);
2520 while (ret == -1 && errno == EINTR);
2525 fprintf (stderr, "my_waitpid (%d, 0x%x): status(%x), %d\n",
2526 pid, flags, status ? *status : -1, ret);
2532 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
2533 sure that we can enable the option, and that it had the desired
2537 linux_test_for_tracefork (void)
2539 int child_pid, ret, status;
2541 char *stack = xmalloc (STACK_SIZE * 4);
2543 linux_supports_tracefork_flag = 0;
2545 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
2547 child_pid = __clone2 (linux_tracefork_child, stack, STACK_SIZE,
2548 CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
2550 child_pid = clone (linux_tracefork_child, stack + STACK_SIZE,
2551 CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
2553 if (child_pid == -1)
2554 perror_with_name ("clone");
2556 ret = my_waitpid (child_pid, &status, 0);
2558 perror_with_name ("waitpid");
2559 else if (ret != child_pid)
2560 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret);
2561 if (! WIFSTOPPED (status))
2562 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status);
2564 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK);
2567 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
2570 warning ("linux_test_for_tracefork: failed to kill child");
2574 ret = my_waitpid (child_pid, &status, 0);
2575 if (ret != child_pid)
2576 warning ("linux_test_for_tracefork: failed to wait for killed child");
2577 else if (!WIFSIGNALED (status))
2578 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
2579 "killed child", status);
2584 ret = ptrace (PTRACE_CONT, child_pid, 0, 0);
2586 warning ("linux_test_for_tracefork: failed to resume child");
2588 ret = my_waitpid (child_pid, &status, 0);
2590 if (ret == child_pid && WIFSTOPPED (status)
2591 && status >> 16 == PTRACE_EVENT_FORK)
2594 ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
2595 if (ret == 0 && second_pid != 0)
2599 linux_supports_tracefork_flag = 1;
2600 my_waitpid (second_pid, &second_status, 0);
2601 ret = ptrace (PTRACE_KILL, second_pid, 0, 0);
2603 warning ("linux_test_for_tracefork: failed to kill second child");
2604 my_waitpid (second_pid, &status, 0);
2608 warning ("linux_test_for_tracefork: unexpected result from waitpid "
2609 "(%d, status 0x%x)", ret, status);
2613 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
2615 warning ("linux_test_for_tracefork: failed to kill child");
2616 my_waitpid (child_pid, &status, 0);
2618 while (WIFSTOPPED (status));
2625 linux_look_up_symbols (void)
2627 #ifdef USE_THREAD_DB
2628 struct process_info *proc = current_process ();
2630 if (proc->private->thread_db_active)
2633 proc->private->thread_db_active
2634 = thread_db_init (!linux_supports_tracefork_flag);
2639 linux_request_interrupt (void)
2641 extern unsigned long signal_pid;
2643 if (!ptid_equal (cont_thread, null_ptid)
2644 && !ptid_equal (cont_thread, minus_one_ptid))
2646 struct lwp_info *lwp;
2649 lwp = get_thread_lwp (current_inferior);
2650 lwpid = lwpid_of (lwp);
2651 kill_lwp (lwpid, SIGINT);
2654 kill_lwp (signal_pid, SIGINT);
2657 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
2658 to debugger memory starting at MYADDR. */
2661 linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len)
2663 char filename[PATH_MAX];
2665 int pid = lwpid_of (get_thread_lwp (current_inferior));
2667 snprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
2669 fd = open (filename, O_RDONLY);
2673 if (offset != (CORE_ADDR) 0
2674 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
2677 n = read (fd, myaddr, len);
2684 /* These breakpoint and watchpoint related wrapper functions simply
2685 pass on the function call if the target has registered a
2686 corresponding function. */
2689 linux_insert_point (char type, CORE_ADDR addr, int len)
2691 if (the_low_target.insert_point != NULL)
2692 return the_low_target.insert_point (type, addr, len);
2694 /* Unsupported (see target.h). */
2699 linux_remove_point (char type, CORE_ADDR addr, int len)
2701 if (the_low_target.remove_point != NULL)
2702 return the_low_target.remove_point (type, addr, len);
2704 /* Unsupported (see target.h). */
2709 linux_stopped_by_watchpoint (void)
2711 if (the_low_target.stopped_by_watchpoint != NULL)
2712 return the_low_target.stopped_by_watchpoint ();
2718 linux_stopped_data_address (void)
2720 if (the_low_target.stopped_data_address != NULL)
2721 return the_low_target.stopped_data_address ();
2726 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
2727 #if defined(__mcoldfire__)
2728 /* These should really be defined in the kernel's ptrace.h header. */
2729 #define PT_TEXT_ADDR 49*4
2730 #define PT_DATA_ADDR 50*4
2731 #define PT_TEXT_END_ADDR 51*4
2734 /* Under uClinux, programs are loaded at non-zero offsets, which we need
2735 to tell gdb about. */
2738 linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p)
2740 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
2741 unsigned long text, text_end, data;
2742 int pid = lwpid_of (get_thread_lwp (current_inferior));
2746 text = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_ADDR, 0);
2747 text_end = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_END_ADDR, 0);
2748 data = ptrace (PTRACE_PEEKUSER, pid, (long)PT_DATA_ADDR, 0);
2752 /* Both text and data offsets produced at compile-time (and so
2753 used by gdb) are relative to the beginning of the program,
2754 with the data segment immediately following the text segment.
2755 However, the actual runtime layout in memory may put the data
2756 somewhere else, so when we send gdb a data base-address, we
2757 use the real data base address and subtract the compile-time
2758 data base-address from it (which is just the length of the
2759 text segment). BSS immediately follows data in both
2762 *data_p = data - (text_end - text);
2772 linux_qxfer_osdata (const char *annex,
2773 unsigned char *readbuf, unsigned const char *writebuf,
2774 CORE_ADDR offset, int len)
2776 /* We make the process list snapshot when the object starts to be
2778 static const char *buf;
2779 static long len_avail = -1;
2780 static struct buffer buffer;
2784 if (strcmp (annex, "processes") != 0)
2787 if (!readbuf || writebuf)
2792 if (len_avail != -1 && len_avail != 0)
2793 buffer_free (&buffer);
2796 buffer_init (&buffer);
2797 buffer_grow_str (&buffer, "<osdata type=\"processes\">");
2799 dirp = opendir ("/proc");
2803 while ((dp = readdir (dirp)) != NULL)
2805 struct stat statbuf;
2806 char procentry[sizeof ("/proc/4294967295")];
2808 if (!isdigit (dp->d_name[0])
2809 || strlen (dp->d_name) > sizeof ("4294967295") - 1)
2812 sprintf (procentry, "/proc/%s", dp->d_name);
2813 if (stat (procentry, &statbuf) == 0
2814 && S_ISDIR (statbuf.st_mode))
2818 char cmd[MAXPATHLEN + 1];
2819 struct passwd *entry;
2821 sprintf (pathname, "/proc/%s/cmdline", dp->d_name);
2822 entry = getpwuid (statbuf.st_uid);
2824 if ((f = fopen (pathname, "r")) != NULL)
2826 size_t len = fread (cmd, 1, sizeof (cmd) - 1, f);
2830 for (i = 0; i < len; i++)
2838 "<column name=\"pid\">%s</column>"
2839 "<column name=\"user\">%s</column>"
2840 "<column name=\"command\">%s</column>"
2843 entry ? entry->pw_name : "?",
2853 buffer_grow_str0 (&buffer, "</osdata>\n");
2854 buf = buffer_finish (&buffer);
2855 len_avail = strlen (buf);
2858 if (offset >= len_avail)
2860 /* Done. Get rid of the data. */
2861 buffer_free (&buffer);
2867 if (len > len_avail - offset)
2868 len = len_avail - offset;
2869 memcpy (readbuf, buf + offset, len);
2874 /* Convert a native/host siginfo object, into/from the siginfo in the
2875 layout of the inferiors' architecture. */
2878 siginfo_fixup (struct siginfo *siginfo, void *inf_siginfo, int direction)
2882 if (the_low_target.siginfo_fixup != NULL)
2883 done = the_low_target.siginfo_fixup (siginfo, inf_siginfo, direction);
2885 /* If there was no callback, or the callback didn't do anything,
2886 then just do a straight memcpy. */
2890 memcpy (siginfo, inf_siginfo, sizeof (struct siginfo));
2892 memcpy (inf_siginfo, siginfo, sizeof (struct siginfo));
2897 linux_xfer_siginfo (const char *annex, unsigned char *readbuf,
2898 unsigned const char *writebuf, CORE_ADDR offset, int len)
2901 struct siginfo siginfo;
2902 char inf_siginfo[sizeof (struct siginfo)];
2904 if (current_inferior == NULL)
2907 pid = lwpid_of (get_thread_lwp (current_inferior));
2910 fprintf (stderr, "%s siginfo for lwp %d.\n",
2911 readbuf != NULL ? "Reading" : "Writing",
2914 if (offset > sizeof (siginfo))
2917 if (ptrace (PTRACE_GETSIGINFO, pid, 0, &siginfo) != 0)
2920 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
2921 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
2922 inferior with a 64-bit GDBSERVER should look the same as debugging it
2923 with a 32-bit GDBSERVER, we need to convert it. */
2924 siginfo_fixup (&siginfo, inf_siginfo, 0);
2926 if (offset + len > sizeof (siginfo))
2927 len = sizeof (siginfo) - offset;
2929 if (readbuf != NULL)
2930 memcpy (readbuf, inf_siginfo + offset, len);
2933 memcpy (inf_siginfo + offset, writebuf, len);
2935 /* Convert back to ptrace layout before flushing it out. */
2936 siginfo_fixup (&siginfo, inf_siginfo, 1);
2938 if (ptrace (PTRACE_SETSIGINFO, pid, 0, &siginfo) != 0)
2945 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
2946 so we notice when children change state; as the handler for the
2947 sigsuspend in my_waitpid. */
2950 sigchld_handler (int signo)
2952 int old_errno = errno;
2955 /* fprintf is not async-signal-safe, so call write directly. */
2956 write (2, "sigchld_handler\n", sizeof ("sigchld_handler\n") - 1);
2958 if (target_is_async_p ())
2959 async_file_mark (); /* trigger a linux_wait */
2965 linux_supports_non_stop (void)
2971 linux_async (int enable)
2973 int previous = (linux_event_pipe[0] != -1);
2975 if (previous != enable)
2978 sigemptyset (&mask);
2979 sigaddset (&mask, SIGCHLD);
2981 sigprocmask (SIG_BLOCK, &mask, NULL);
2985 if (pipe (linux_event_pipe) == -1)
2986 fatal ("creating event pipe failed.");
2988 fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK);
2989 fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK);
2991 /* Register the event loop handler. */
2992 add_file_handler (linux_event_pipe[0],
2993 handle_target_event, NULL);
2995 /* Always trigger a linux_wait. */
3000 delete_file_handler (linux_event_pipe[0]);
3002 close (linux_event_pipe[0]);
3003 close (linux_event_pipe[1]);
3004 linux_event_pipe[0] = -1;
3005 linux_event_pipe[1] = -1;
3008 sigprocmask (SIG_UNBLOCK, &mask, NULL);
3015 linux_start_non_stop (int nonstop)
3017 /* Register or unregister from event-loop accordingly. */
3018 linux_async (nonstop);
3023 linux_supports_multi_process (void)
3028 static struct target_ops linux_target_ops = {
3029 linux_create_inferior,
3037 linux_fetch_registers,
3038 linux_store_registers,
3041 linux_look_up_symbols,
3042 linux_request_interrupt,
3046 linux_stopped_by_watchpoint,
3047 linux_stopped_data_address,
3048 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
3053 #ifdef USE_THREAD_DB
3054 thread_db_get_tls_address,
3059 hostio_last_error_from_errno,
3062 linux_supports_non_stop,
3064 linux_start_non_stop,
3065 linux_supports_multi_process
3069 linux_init_signals ()
3071 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
3072 to find what the cancel signal actually is. */
3073 signal (__SIGRTMIN+1, SIG_IGN);
3077 initialize_low (void)
3079 struct sigaction sigchld_action;
3080 memset (&sigchld_action, 0, sizeof (sigchld_action));
3081 set_target_ops (&linux_target_ops);
3082 set_breakpoint_data (the_low_target.breakpoint,
3083 the_low_target.breakpoint_len);
3084 linux_init_signals ();
3085 linux_test_for_tracefork ();
3086 #ifdef HAVE_LINUX_REGSETS
3087 for (num_regsets = 0; target_regsets[num_regsets].size >= 0; num_regsets++)
3089 disabled_regsets = xmalloc (num_regsets);
3092 sigchld_action.sa_handler = sigchld_handler;
3093 sigemptyset (&sigchld_action.sa_mask);
3094 sigchld_action.sa_flags = SA_RESTART;
3095 sigaction (SIGCHLD, &sigchld_action, NULL);