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"
25 #include <sys/param.h>
26 #include <sys/ptrace.h>
27 #include "linux-ptrace.h"
28 #include "linux-procfs.h"
30 #include <sys/ioctl.h>
36 #include <sys/syscall.h>
40 #include <sys/types.h>
46 /* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h
47 then ELFMAG0 will have been defined. If it didn't get included by
48 gdb_proc_service.h then including it will likely introduce a duplicate
49 definition of elf_fpregset_t. */
54 #define SPUFS_MAGIC 0x23c9b64e
57 #ifdef HAVE_PERSONALITY
58 # include <sys/personality.h>
59 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
60 # define ADDR_NO_RANDOMIZE 0x0040000
69 #define W_STOPCODE(sig) ((sig) << 8 | 0x7f)
72 /* This is the kernel's hard limit. Not to be confused with
79 #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
84 /* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
85 representation of the thread ID.
87 ``all_lwps'' is keyed by the process ID - which on Linux is (presently)
88 the same as the LWP ID.
90 ``all_processes'' is keyed by the "overall process ID", which
91 GNU/Linux calls tgid, "thread group ID". */
93 struct inferior_list all_lwps;
95 /* A list of all unknown processes which receive stop signals. Some other
96 process will presumably claim each of these as forked children
99 struct inferior_list stopped_pids;
101 /* FIXME this is a bit of a hack, and could be removed. */
102 int stopping_threads;
104 /* FIXME make into a target method? */
105 int using_threads = 1;
107 /* True if we're presently stabilizing threads (moving them out of
109 static int stabilizing_threads;
111 /* This flag is true iff we've just created or attached to our first
112 inferior but it has not stopped yet. As soon as it does, we need
113 to call the low target's arch_setup callback. Doing this only on
114 the first inferior avoids reinializing the architecture on every
115 inferior, and avoids messing with the register caches of the
116 already running inferiors. NOTE: this assumes all inferiors under
117 control of gdbserver have the same architecture. */
118 static int new_inferior;
120 static void linux_resume_one_lwp (struct lwp_info *lwp,
121 int step, int signal, siginfo_t *info);
122 static void linux_resume (struct thread_resume *resume_info, size_t n);
123 static void stop_all_lwps (int suspend, struct lwp_info *except);
124 static void unstop_all_lwps (int unsuspend, struct lwp_info *except);
125 static int linux_wait_for_event (ptid_t ptid, int *wstat, int options);
126 static void *add_lwp (ptid_t ptid);
127 static int linux_stopped_by_watchpoint (void);
128 static void mark_lwp_dead (struct lwp_info *lwp, int wstat);
129 static void proceed_all_lwps (void);
130 static int finish_step_over (struct lwp_info *lwp);
131 static CORE_ADDR get_stop_pc (struct lwp_info *lwp);
132 static int kill_lwp (unsigned long lwpid, int signo);
133 static void linux_enable_event_reporting (int pid);
135 /* True if the low target can hardware single-step. Such targets
136 don't need a BREAKPOINT_REINSERT_ADDR callback. */
139 can_hardware_single_step (void)
141 return (the_low_target.breakpoint_reinsert_addr == NULL);
144 /* True if the low target supports memory breakpoints. If so, we'll
145 have a GET_PC implementation. */
148 supports_breakpoints (void)
150 return (the_low_target.get_pc != NULL);
153 /* Returns true if this target can support fast tracepoints. This
154 does not mean that the in-process agent has been loaded in the
158 supports_fast_tracepoints (void)
160 return the_low_target.install_fast_tracepoint_jump_pad != NULL;
163 struct pending_signals
167 struct pending_signals *prev;
170 #define PTRACE_ARG3_TYPE void *
171 #define PTRACE_ARG4_TYPE void *
172 #define PTRACE_XFER_TYPE long
174 #ifdef HAVE_LINUX_REGSETS
175 static char *disabled_regsets;
176 static int num_regsets;
179 /* The read/write ends of the pipe registered as waitable file in the
181 static int linux_event_pipe[2] = { -1, -1 };
183 /* True if we're currently in async mode. */
184 #define target_is_async_p() (linux_event_pipe[0] != -1)
186 static void send_sigstop (struct lwp_info *lwp);
187 static void wait_for_sigstop (struct inferior_list_entry *entry);
189 /* Return non-zero if HEADER is a 64-bit ELF file. */
192 elf_64_header_p (const Elf64_Ehdr *header)
194 return (header->e_ident[EI_MAG0] == ELFMAG0
195 && header->e_ident[EI_MAG1] == ELFMAG1
196 && header->e_ident[EI_MAG2] == ELFMAG2
197 && header->e_ident[EI_MAG3] == ELFMAG3
198 && header->e_ident[EI_CLASS] == ELFCLASS64);
201 /* Return non-zero if FILE is a 64-bit ELF file,
202 zero if the file is not a 64-bit ELF file,
203 and -1 if the file is not accessible or doesn't exist. */
206 elf_64_file_p (const char *file)
211 fd = open (file, O_RDONLY);
215 if (read (fd, &header, sizeof (header)) != sizeof (header))
222 return elf_64_header_p (&header);
225 /* Accepts an integer PID; Returns true if the executable PID is
226 running is a 64-bit ELF file.. */
229 linux_pid_exe_is_elf_64_file (int pid)
231 char file[MAXPATHLEN];
233 sprintf (file, "/proc/%d/exe", pid);
234 return elf_64_file_p (file);
238 delete_lwp (struct lwp_info *lwp)
240 remove_thread (get_lwp_thread (lwp));
241 remove_inferior (&all_lwps, &lwp->head);
242 free (lwp->arch_private);
246 /* Add a process to the common process list, and set its private
249 static struct process_info *
250 linux_add_process (int pid, int attached)
252 struct process_info *proc;
254 /* Is this the first process? If so, then set the arch. */
255 if (all_processes.head == NULL)
258 proc = add_process (pid, attached);
259 proc->private = xcalloc (1, sizeof (*proc->private));
261 if (the_low_target.new_process != NULL)
262 proc->private->arch_private = the_low_target.new_process ();
267 /* Wrapper function for waitpid which handles EINTR, and emulates
268 __WALL for systems where that is not available. */
271 my_waitpid (int pid, int *status, int flags)
276 fprintf (stderr, "my_waitpid (%d, 0x%x)\n", pid, flags);
280 sigset_t block_mask, org_mask, wake_mask;
283 wnohang = (flags & WNOHANG) != 0;
284 flags &= ~(__WALL | __WCLONE);
287 /* Block all signals while here. This avoids knowing about
288 LinuxThread's signals. */
289 sigfillset (&block_mask);
290 sigprocmask (SIG_BLOCK, &block_mask, &org_mask);
292 /* ... except during the sigsuspend below. */
293 sigemptyset (&wake_mask);
297 /* Since all signals are blocked, there's no need to check
299 ret = waitpid (pid, status, flags);
302 if (ret == -1 && out_errno != ECHILD)
307 if (flags & __WCLONE)
309 /* We've tried both flavors now. If WNOHANG is set,
310 there's nothing else to do, just bail out. */
315 fprintf (stderr, "blocking\n");
317 /* Block waiting for signals. */
318 sigsuspend (&wake_mask);
324 sigprocmask (SIG_SETMASK, &org_mask, NULL);
329 ret = waitpid (pid, status, flags);
330 while (ret == -1 && errno == EINTR);
335 fprintf (stderr, "my_waitpid (%d, 0x%x): status(%x), %d\n",
336 pid, flags, status ? *status : -1, ret);
342 /* Handle a GNU/Linux extended wait response. If we see a clone
343 event, we need to add the new LWP to our list (and not report the
344 trap to higher layers). */
347 handle_extended_wait (struct lwp_info *event_child, int wstat)
349 int event = wstat >> 16;
350 struct lwp_info *new_lwp;
352 if (event == PTRACE_EVENT_CLONE)
355 unsigned long new_pid;
356 int ret, status = W_STOPCODE (SIGSTOP);
358 ptrace (PTRACE_GETEVENTMSG, lwpid_of (event_child), 0, &new_pid);
360 /* If we haven't already seen the new PID stop, wait for it now. */
361 if (! pull_pid_from_list (&stopped_pids, new_pid))
363 /* The new child has a pending SIGSTOP. We can't affect it until it
364 hits the SIGSTOP, but we're already attached. */
366 ret = my_waitpid (new_pid, &status, __WALL);
369 perror_with_name ("waiting for new child");
370 else if (ret != new_pid)
371 warning ("wait returned unexpected PID %d", ret);
372 else if (!WIFSTOPPED (status))
373 warning ("wait returned unexpected status 0x%x", status);
376 linux_enable_event_reporting (new_pid);
378 ptid = ptid_build (pid_of (event_child), new_pid, 0);
379 new_lwp = (struct lwp_info *) add_lwp (ptid);
380 add_thread (ptid, new_lwp);
382 /* Either we're going to immediately resume the new thread
383 or leave it stopped. linux_resume_one_lwp is a nop if it
384 thinks the thread is currently running, so set this first
385 before calling linux_resume_one_lwp. */
386 new_lwp->stopped = 1;
388 /* Normally we will get the pending SIGSTOP. But in some cases
389 we might get another signal delivered to the group first.
390 If we do get another signal, be sure not to lose it. */
391 if (WSTOPSIG (status) == SIGSTOP)
393 if (stopping_threads)
394 new_lwp->stop_pc = get_stop_pc (new_lwp);
396 linux_resume_one_lwp (new_lwp, 0, 0, NULL);
400 new_lwp->stop_expected = 1;
402 if (stopping_threads)
404 new_lwp->stop_pc = get_stop_pc (new_lwp);
405 new_lwp->status_pending_p = 1;
406 new_lwp->status_pending = status;
409 /* Pass the signal on. This is what GDB does - except
410 shouldn't we really report it instead? */
411 linux_resume_one_lwp (new_lwp, 0, WSTOPSIG (status), NULL);
414 /* Always resume the current thread. If we are stopping
415 threads, it will have a pending SIGSTOP; we may as well
417 linux_resume_one_lwp (event_child, event_child->stepping, 0, NULL);
421 /* Return the PC as read from the regcache of LWP, without any
425 get_pc (struct lwp_info *lwp)
427 struct thread_info *saved_inferior;
428 struct regcache *regcache;
431 if (the_low_target.get_pc == NULL)
434 saved_inferior = current_inferior;
435 current_inferior = get_lwp_thread (lwp);
437 regcache = get_thread_regcache (current_inferior, 1);
438 pc = (*the_low_target.get_pc) (regcache);
441 fprintf (stderr, "pc is 0x%lx\n", (long) pc);
443 current_inferior = saved_inferior;
447 /* This function should only be called if LWP got a SIGTRAP.
448 The SIGTRAP could mean several things.
450 On i386, where decr_pc_after_break is non-zero:
451 If we were single-stepping this process using PTRACE_SINGLESTEP,
452 we will get only the one SIGTRAP (even if the instruction we
453 stepped over was a breakpoint). The value of $eip will be the
455 If we continue the process using PTRACE_CONT, we will get a
456 SIGTRAP when we hit a breakpoint. The value of $eip will be
457 the instruction after the breakpoint (i.e. needs to be
458 decremented). If we report the SIGTRAP to GDB, we must also
459 report the undecremented PC. If we cancel the SIGTRAP, we
460 must resume at the decremented PC.
462 (Presumably, not yet tested) On a non-decr_pc_after_break machine
463 with hardware or kernel single-step:
464 If we single-step over a breakpoint instruction, our PC will
465 point at the following instruction. If we continue and hit a
466 breakpoint instruction, our PC will point at the breakpoint
470 get_stop_pc (struct lwp_info *lwp)
474 if (the_low_target.get_pc == NULL)
477 stop_pc = get_pc (lwp);
479 if (WSTOPSIG (lwp->last_status) == SIGTRAP
481 && !lwp->stopped_by_watchpoint
482 && lwp->last_status >> 16 == 0)
483 stop_pc -= the_low_target.decr_pc_after_break;
486 fprintf (stderr, "stop pc is 0x%lx\n", (long) stop_pc);
492 add_lwp (ptid_t ptid)
494 struct lwp_info *lwp;
496 lwp = (struct lwp_info *) xmalloc (sizeof (*lwp));
497 memset (lwp, 0, sizeof (*lwp));
501 if (the_low_target.new_thread != NULL)
502 lwp->arch_private = the_low_target.new_thread ();
504 add_inferior_to_list (&all_lwps, &lwp->head);
509 /* Start an inferior process and returns its pid.
510 ALLARGS is a vector of program-name and args. */
513 linux_create_inferior (char *program, char **allargs)
515 #ifdef HAVE_PERSONALITY
516 int personality_orig = 0, personality_set = 0;
518 struct lwp_info *new_lwp;
522 #ifdef HAVE_PERSONALITY
523 if (disable_randomization)
526 personality_orig = personality (0xffffffff);
527 if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE))
530 personality (personality_orig | ADDR_NO_RANDOMIZE);
532 if (errno != 0 || (personality_set
533 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE)))
534 warning ("Error disabling address space randomization: %s",
539 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
545 perror_with_name ("fork");
549 ptrace (PTRACE_TRACEME, 0, 0, 0);
551 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
552 signal (__SIGRTMIN + 1, SIG_DFL);
557 /* If gdbserver is connected to gdb via stdio, redirect the inferior's
558 stdout to stderr so that inferior i/o doesn't corrupt the connection.
559 Also, redirect stdin to /dev/null. */
560 if (remote_connection_is_stdio ())
563 open ("/dev/null", O_RDONLY);
565 if (write (2, "stdin/stdout redirected\n",
566 sizeof ("stdin/stdout redirected\n") - 1) < 0)
567 /* Errors ignored. */;
570 execv (program, allargs);
572 execvp (program, allargs);
574 fprintf (stderr, "Cannot exec %s: %s.\n", program,
580 #ifdef HAVE_PERSONALITY
584 personality (personality_orig);
586 warning ("Error restoring address space randomization: %s",
591 linux_add_process (pid, 0);
593 ptid = ptid_build (pid, pid, 0);
594 new_lwp = add_lwp (ptid);
595 add_thread (ptid, new_lwp);
596 new_lwp->must_set_ptrace_flags = 1;
601 /* Attach to an inferior process. */
604 linux_attach_lwp_1 (unsigned long lwpid, int initial)
607 struct lwp_info *new_lwp;
609 if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) != 0)
613 /* If we fail to attach to an LWP, just warn. */
614 fprintf (stderr, "Cannot attach to lwp %ld: %s (%d)\n", lwpid,
615 strerror (errno), errno);
620 /* If we fail to attach to a process, report an error. */
621 error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid,
622 strerror (errno), errno);
626 /* If lwp is the tgid, we handle adding existing threads later.
627 Otherwise we just add lwp without bothering about any other
629 ptid = ptid_build (lwpid, lwpid, 0);
632 /* Note that extracting the pid from the current inferior is
633 safe, since we're always called in the context of the same
634 process as this new thread. */
635 int pid = pid_of (get_thread_lwp (current_inferior));
636 ptid = ptid_build (pid, lwpid, 0);
639 new_lwp = (struct lwp_info *) add_lwp (ptid);
640 add_thread (ptid, new_lwp);
642 /* We need to wait for SIGSTOP before being able to make the next
643 ptrace call on this LWP. */
644 new_lwp->must_set_ptrace_flags = 1;
646 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
649 There are several cases to consider here:
651 1) gdbserver has already attached to the process and is being notified
652 of a new thread that is being created.
653 In this case we should ignore that SIGSTOP and resume the
654 process. This is handled below by setting stop_expected = 1,
655 and the fact that add_thread sets last_resume_kind ==
658 2) This is the first thread (the process thread), and we're attaching
659 to it via attach_inferior.
660 In this case we want the process thread to stop.
661 This is handled by having linux_attach set last_resume_kind ==
662 resume_stop after we return.
664 If the pid we are attaching to is also the tgid, we attach to and
665 stop all the existing threads. Otherwise, we attach to pid and
666 ignore any other threads in the same group as this pid.
668 3) GDB is connecting to gdbserver and is requesting an enumeration of all
670 In this case we want the thread to stop.
671 FIXME: This case is currently not properly handled.
672 We should wait for the SIGSTOP but don't. Things work apparently
673 because enough time passes between when we ptrace (ATTACH) and when
674 gdb makes the next ptrace call on the thread.
676 On the other hand, if we are currently trying to stop all threads, we
677 should treat the new thread as if we had sent it a SIGSTOP. This works
678 because we are guaranteed that the add_lwp call above added us to the
679 end of the list, and so the new thread has not yet reached
680 wait_for_sigstop (but will). */
681 new_lwp->stop_expected = 1;
685 linux_attach_lwp (unsigned long lwpid)
687 linux_attach_lwp_1 (lwpid, 0);
690 /* Attach to PID. If PID is the tgid, attach to it and all
694 linux_attach (unsigned long pid)
696 /* Attach to PID. We will check for other threads
698 linux_attach_lwp_1 (pid, 1);
699 linux_add_process (pid, 1);
703 struct thread_info *thread;
705 /* Don't ignore the initial SIGSTOP if we just attached to this
706 process. It will be collected by wait shortly. */
707 thread = find_thread_ptid (ptid_build (pid, pid, 0));
708 thread->last_resume_kind = resume_stop;
711 if (linux_proc_get_tgid (pid) == pid)
716 sprintf (pathname, "/proc/%ld/task", pid);
718 dir = opendir (pathname);
722 fprintf (stderr, "Could not open /proc/%ld/task.\n", pid);
727 /* At this point we attached to the tgid. Scan the task for
730 int new_threads_found;
734 while (iterations < 2)
736 new_threads_found = 0;
737 /* Add all the other threads. While we go through the
738 threads, new threads may be spawned. Cycle through
739 the list of threads until we have done two iterations without
740 finding new threads. */
741 while ((dp = readdir (dir)) != NULL)
744 lwp = strtoul (dp->d_name, NULL, 10);
746 /* Is this a new thread? */
748 && find_thread_ptid (ptid_build (pid, lwp, 0)) == NULL)
750 linux_attach_lwp_1 (lwp, 0);
755 Found and attached to new lwp %ld\n", lwp);
759 if (!new_threads_found)
780 second_thread_of_pid_p (struct inferior_list_entry *entry, void *args)
782 struct counter *counter = args;
784 if (ptid_get_pid (entry->id) == counter->pid)
786 if (++counter->count > 1)
794 last_thread_of_process_p (struct thread_info *thread)
796 ptid_t ptid = ((struct inferior_list_entry *)thread)->id;
797 int pid = ptid_get_pid (ptid);
798 struct counter counter = { pid , 0 };
800 return (find_inferior (&all_threads,
801 second_thread_of_pid_p, &counter) == NULL);
807 linux_kill_one_lwp (struct lwp_info *lwp)
809 int pid = lwpid_of (lwp);
811 /* PTRACE_KILL is unreliable. After stepping into a signal handler,
812 there is no signal context, and ptrace(PTRACE_KILL) (or
813 ptrace(PTRACE_CONT, SIGKILL), pretty much the same) acts like
814 ptrace(CONT, pid, 0,0) and just resumes the tracee. A better
815 alternative is to kill with SIGKILL. We only need one SIGKILL
816 per process, not one for each thread. But since we still support
817 linuxthreads, and we also support debugging programs using raw
818 clone without CLONE_THREAD, we send one for each thread. For
819 years, we used PTRACE_KILL only, so we're being a bit paranoid
820 about some old kernels where PTRACE_KILL might work better
821 (dubious if there are any such, but that's why it's paranoia), so
822 we try SIGKILL first, PTRACE_KILL second, and so we're fine
829 "LKL: kill (SIGKILL) %s, 0, 0 (%s)\n",
830 target_pid_to_str (ptid_of (lwp)),
831 errno ? strerror (errno) : "OK");
834 ptrace (PTRACE_KILL, pid, 0, 0);
837 "LKL: PTRACE_KILL %s, 0, 0 (%s)\n",
838 target_pid_to_str (ptid_of (lwp)),
839 errno ? strerror (errno) : "OK");
842 /* Callback for `find_inferior'. Kills an lwp of a given process,
843 except the leader. */
846 kill_one_lwp_callback (struct inferior_list_entry *entry, void *args)
848 struct thread_info *thread = (struct thread_info *) entry;
849 struct lwp_info *lwp = get_thread_lwp (thread);
851 int pid = * (int *) args;
853 if (ptid_get_pid (entry->id) != pid)
856 /* We avoid killing the first thread here, because of a Linux kernel (at
857 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
858 the children get a chance to be reaped, it will remain a zombie
861 if (lwpid_of (lwp) == pid)
864 fprintf (stderr, "lkop: is last of process %s\n",
865 target_pid_to_str (entry->id));
871 linux_kill_one_lwp (lwp);
873 /* Make sure it died. The loop is most likely unnecessary. */
874 pid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
875 } while (pid > 0 && WIFSTOPPED (wstat));
883 struct process_info *process;
884 struct lwp_info *lwp;
888 process = find_process_pid (pid);
892 /* If we're killing a running inferior, make sure it is stopped
893 first, as PTRACE_KILL will not work otherwise. */
894 stop_all_lwps (0, NULL);
896 find_inferior (&all_threads, kill_one_lwp_callback , &pid);
898 /* See the comment in linux_kill_one_lwp. We did not kill the first
899 thread in the list, so do so now. */
900 lwp = find_lwp_pid (pid_to_ptid (pid));
905 fprintf (stderr, "lk_1: cannot find lwp %ld, for pid: %d\n",
906 lwpid_of (lwp), pid);
911 fprintf (stderr, "lk_1: killing lwp %ld, for pid: %d\n",
912 lwpid_of (lwp), pid);
916 linux_kill_one_lwp (lwp);
918 /* Make sure it died. The loop is most likely unnecessary. */
919 lwpid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
920 } while (lwpid > 0 && WIFSTOPPED (wstat));
923 the_target->mourn (process);
925 /* Since we presently can only stop all lwps of all processes, we
926 need to unstop lwps of other processes. */
927 unstop_all_lwps (0, NULL);
932 linux_detach_one_lwp (struct inferior_list_entry *entry, void *args)
934 struct thread_info *thread = (struct thread_info *) entry;
935 struct lwp_info *lwp = get_thread_lwp (thread);
936 int pid = * (int *) args;
938 if (ptid_get_pid (entry->id) != pid)
941 /* If this process is stopped but is expecting a SIGSTOP, then make
942 sure we take care of that now. This isn't absolutely guaranteed
943 to collect the SIGSTOP, but is fairly likely to. */
944 if (lwp->stop_expected)
947 /* Clear stop_expected, so that the SIGSTOP will be reported. */
948 lwp->stop_expected = 0;
949 linux_resume_one_lwp (lwp, 0, 0, NULL);
950 linux_wait_for_event (lwp->head.id, &wstat, __WALL);
953 /* Flush any pending changes to the process's registers. */
954 regcache_invalidate_one ((struct inferior_list_entry *)
955 get_lwp_thread (lwp));
957 /* Finally, let it resume. */
958 if (the_low_target.prepare_to_resume != NULL)
959 the_low_target.prepare_to_resume (lwp);
960 ptrace (PTRACE_DETACH, lwpid_of (lwp), 0, 0);
967 linux_detach (int pid)
969 struct process_info *process;
971 process = find_process_pid (pid);
975 /* Stop all threads before detaching. First, ptrace requires that
976 the thread is stopped to sucessfully detach. Second, thread_db
977 may need to uninstall thread event breakpoints from memory, which
978 only works with a stopped process anyway. */
979 stop_all_lwps (0, NULL);
982 thread_db_detach (process);
985 /* Stabilize threads (move out of jump pads). */
986 stabilize_threads ();
988 find_inferior (&all_threads, linux_detach_one_lwp, &pid);
990 the_target->mourn (process);
992 /* Since we presently can only stop all lwps of all processes, we
993 need to unstop lwps of other processes. */
994 unstop_all_lwps (0, NULL);
998 /* Remove all LWPs that belong to process PROC from the lwp list. */
1001 delete_lwp_callback (struct inferior_list_entry *entry, void *proc)
1003 struct lwp_info *lwp = (struct lwp_info *) entry;
1004 struct process_info *process = proc;
1006 if (pid_of (lwp) == pid_of (process))
1013 linux_mourn (struct process_info *process)
1015 struct process_info_private *priv;
1017 #ifdef USE_THREAD_DB
1018 thread_db_mourn (process);
1021 find_inferior (&all_lwps, delete_lwp_callback, process);
1023 /* Freeing all private data. */
1024 priv = process->private;
1025 free (priv->arch_private);
1027 process->private = NULL;
1029 remove_process (process);
1033 linux_join (int pid)
1038 ret = my_waitpid (pid, &status, 0);
1039 if (WIFEXITED (status) || WIFSIGNALED (status))
1041 } while (ret != -1 || errno != ECHILD);
1044 /* Return nonzero if the given thread is still alive. */
1046 linux_thread_alive (ptid_t ptid)
1048 struct lwp_info *lwp = find_lwp_pid (ptid);
1050 /* We assume we always know if a thread exits. If a whole process
1051 exited but we still haven't been able to report it to GDB, we'll
1052 hold on to the last lwp of the dead process. */
1059 /* Return 1 if this lwp has an interesting status pending. */
1061 status_pending_p_callback (struct inferior_list_entry *entry, void *arg)
1063 struct lwp_info *lwp = (struct lwp_info *) entry;
1064 ptid_t ptid = * (ptid_t *) arg;
1065 struct thread_info *thread;
1067 /* Check if we're only interested in events from a specific process
1069 if (!ptid_equal (minus_one_ptid, ptid)
1070 && ptid_get_pid (ptid) != ptid_get_pid (lwp->head.id))
1073 thread = get_lwp_thread (lwp);
1075 /* If we got a `vCont;t', but we haven't reported a stop yet, do
1076 report any status pending the LWP may have. */
1077 if (thread->last_resume_kind == resume_stop
1078 && thread->last_status.kind != TARGET_WAITKIND_IGNORE)
1081 return lwp->status_pending_p;
1085 same_lwp (struct inferior_list_entry *entry, void *data)
1087 ptid_t ptid = *(ptid_t *) data;
1090 if (ptid_get_lwp (ptid) != 0)
1091 lwp = ptid_get_lwp (ptid);
1093 lwp = ptid_get_pid (ptid);
1095 if (ptid_get_lwp (entry->id) == lwp)
1102 find_lwp_pid (ptid_t ptid)
1104 return (struct lwp_info*) find_inferior (&all_lwps, same_lwp, &ptid);
1107 static struct lwp_info *
1108 linux_wait_for_lwp (ptid_t ptid, int *wstatp, int options)
1111 int to_wait_for = -1;
1112 struct lwp_info *child = NULL;
1115 fprintf (stderr, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid));
1117 if (ptid_equal (ptid, minus_one_ptid))
1118 to_wait_for = -1; /* any child */
1120 to_wait_for = ptid_get_lwp (ptid); /* this lwp only */
1126 ret = my_waitpid (to_wait_for, wstatp, options);
1127 if (ret == 0 || (ret == -1 && errno == ECHILD && (options & WNOHANG)))
1130 perror_with_name ("waitpid");
1133 && (!WIFSTOPPED (*wstatp)
1134 || (WSTOPSIG (*wstatp) != 32
1135 && WSTOPSIG (*wstatp) != 33)))
1136 fprintf (stderr, "Got an event from %d (%x)\n", ret, *wstatp);
1138 child = find_lwp_pid (pid_to_ptid (ret));
1140 /* If we didn't find a process, one of two things presumably happened:
1141 - A process we started and then detached from has exited. Ignore it.
1142 - A process we are controlling has forked and the new child's stop
1143 was reported to us by the kernel. Save its PID. */
1144 if (child == NULL && WIFSTOPPED (*wstatp))
1146 add_pid_to_list (&stopped_pids, ret);
1149 else if (child == NULL)
1154 child->last_status = *wstatp;
1156 /* Architecture-specific setup after inferior is running.
1157 This needs to happen after we have attached to the inferior
1158 and it is stopped for the first time, but before we access
1159 any inferior registers. */
1162 the_low_target.arch_setup ();
1163 #ifdef HAVE_LINUX_REGSETS
1164 memset (disabled_regsets, 0, num_regsets);
1169 /* Fetch the possibly triggered data watchpoint info and store it in
1172 On some archs, like x86, that use debug registers to set
1173 watchpoints, it's possible that the way to know which watched
1174 address trapped, is to check the register that is used to select
1175 which address to watch. Problem is, between setting the
1176 watchpoint and reading back which data address trapped, the user
1177 may change the set of watchpoints, and, as a consequence, GDB
1178 changes the debug registers in the inferior. To avoid reading
1179 back a stale stopped-data-address when that happens, we cache in
1180 LP the fact that a watchpoint trapped, and the corresponding data
1181 address, as soon as we see CHILD stop with a SIGTRAP. If GDB
1182 changes the debug registers meanwhile, we have the cached data we
1185 if (WIFSTOPPED (*wstatp) && WSTOPSIG (*wstatp) == SIGTRAP)
1187 if (the_low_target.stopped_by_watchpoint == NULL)
1189 child->stopped_by_watchpoint = 0;
1193 struct thread_info *saved_inferior;
1195 saved_inferior = current_inferior;
1196 current_inferior = get_lwp_thread (child);
1198 child->stopped_by_watchpoint
1199 = the_low_target.stopped_by_watchpoint ();
1201 if (child->stopped_by_watchpoint)
1203 if (the_low_target.stopped_data_address != NULL)
1204 child->stopped_data_address
1205 = the_low_target.stopped_data_address ();
1207 child->stopped_data_address = 0;
1210 current_inferior = saved_inferior;
1214 /* Store the STOP_PC, with adjustment applied. This depends on the
1215 architecture being defined already (so that CHILD has a valid
1216 regcache), and on LAST_STATUS being set (to check for SIGTRAP or
1218 if (WIFSTOPPED (*wstatp))
1219 child->stop_pc = get_stop_pc (child);
1222 && WIFSTOPPED (*wstatp)
1223 && the_low_target.get_pc != NULL)
1225 struct thread_info *saved_inferior = current_inferior;
1226 struct regcache *regcache;
1229 current_inferior = get_lwp_thread (child);
1230 regcache = get_thread_regcache (current_inferior, 1);
1231 pc = (*the_low_target.get_pc) (regcache);
1232 fprintf (stderr, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc);
1233 current_inferior = saved_inferior;
1239 /* This function should only be called if the LWP got a SIGTRAP.
1241 Handle any tracepoint steps or hits. Return true if a tracepoint
1242 event was handled, 0 otherwise. */
1245 handle_tracepoints (struct lwp_info *lwp)
1247 struct thread_info *tinfo = get_lwp_thread (lwp);
1248 int tpoint_related_event = 0;
1250 /* If this tracepoint hit causes a tracing stop, we'll immediately
1251 uninsert tracepoints. To do this, we temporarily pause all
1252 threads, unpatch away, and then unpause threads. We need to make
1253 sure the unpausing doesn't resume LWP too. */
1256 /* And we need to be sure that any all-threads-stopping doesn't try
1257 to move threads out of the jump pads, as it could deadlock the
1258 inferior (LWP could be in the jump pad, maybe even holding the
1261 /* Do any necessary step collect actions. */
1262 tpoint_related_event |= tracepoint_finished_step (tinfo, lwp->stop_pc);
1264 tpoint_related_event |= handle_tracepoint_bkpts (tinfo, lwp->stop_pc);
1266 /* See if we just hit a tracepoint and do its main collect
1268 tpoint_related_event |= tracepoint_was_hit (tinfo, lwp->stop_pc);
1272 gdb_assert (lwp->suspended == 0);
1273 gdb_assert (!stabilizing_threads || lwp->collecting_fast_tracepoint);
1275 if (tpoint_related_event)
1278 fprintf (stderr, "got a tracepoint event\n");
1285 /* Convenience wrapper. Returns true if LWP is presently collecting a
1289 linux_fast_tracepoint_collecting (struct lwp_info *lwp,
1290 struct fast_tpoint_collect_status *status)
1292 CORE_ADDR thread_area;
1294 if (the_low_target.get_thread_area == NULL)
1297 /* Get the thread area address. This is used to recognize which
1298 thread is which when tracing with the in-process agent library.
1299 We don't read anything from the address, and treat it as opaque;
1300 it's the address itself that we assume is unique per-thread. */
1301 if ((*the_low_target.get_thread_area) (lwpid_of (lwp), &thread_area) == -1)
1304 return fast_tracepoint_collecting (thread_area, lwp->stop_pc, status);
1307 /* The reason we resume in the caller, is because we want to be able
1308 to pass lwp->status_pending as WSTAT, and we need to clear
1309 status_pending_p before resuming, otherwise, linux_resume_one_lwp
1310 refuses to resume. */
1313 maybe_move_out_of_jump_pad (struct lwp_info *lwp, int *wstat)
1315 struct thread_info *saved_inferior;
1317 saved_inferior = current_inferior;
1318 current_inferior = get_lwp_thread (lwp);
1321 || (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) != SIGTRAP))
1322 && supports_fast_tracepoints ()
1323 && in_process_agent_loaded ())
1325 struct fast_tpoint_collect_status status;
1330 Checking whether LWP %ld needs to move out of the jump pad.\n",
1333 r = linux_fast_tracepoint_collecting (lwp, &status);
1336 || (WSTOPSIG (*wstat) != SIGILL
1337 && WSTOPSIG (*wstat) != SIGFPE
1338 && WSTOPSIG (*wstat) != SIGSEGV
1339 && WSTOPSIG (*wstat) != SIGBUS))
1341 lwp->collecting_fast_tracepoint = r;
1345 if (r == 1 && lwp->exit_jump_pad_bkpt == NULL)
1347 /* Haven't executed the original instruction yet.
1348 Set breakpoint there, and wait till it's hit,
1349 then single-step until exiting the jump pad. */
1350 lwp->exit_jump_pad_bkpt
1351 = set_breakpoint_at (status.adjusted_insn_addr, NULL);
1356 Checking whether LWP %ld needs to move out of the jump pad...it does\n",
1358 current_inferior = saved_inferior;
1365 /* If we get a synchronous signal while collecting, *and*
1366 while executing the (relocated) original instruction,
1367 reset the PC to point at the tpoint address, before
1368 reporting to GDB. Otherwise, it's an IPA lib bug: just
1369 report the signal to GDB, and pray for the best. */
1371 lwp->collecting_fast_tracepoint = 0;
1374 && (status.adjusted_insn_addr <= lwp->stop_pc
1375 && lwp->stop_pc < status.adjusted_insn_addr_end))
1378 struct regcache *regcache;
1380 /* The si_addr on a few signals references the address
1381 of the faulting instruction. Adjust that as
1383 if ((WSTOPSIG (*wstat) == SIGILL
1384 || WSTOPSIG (*wstat) == SIGFPE
1385 || WSTOPSIG (*wstat) == SIGBUS
1386 || WSTOPSIG (*wstat) == SIGSEGV)
1387 && ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &info) == 0
1388 /* Final check just to make sure we don't clobber
1389 the siginfo of non-kernel-sent signals. */
1390 && (uintptr_t) info.si_addr == lwp->stop_pc)
1392 info.si_addr = (void *) (uintptr_t) status.tpoint_addr;
1393 ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &info);
1396 regcache = get_thread_regcache (get_lwp_thread (lwp), 1);
1397 (*the_low_target.set_pc) (regcache, status.tpoint_addr);
1398 lwp->stop_pc = status.tpoint_addr;
1400 /* Cancel any fast tracepoint lock this thread was
1402 force_unlock_trace_buffer ();
1405 if (lwp->exit_jump_pad_bkpt != NULL)
1409 "Cancelling fast exit-jump-pad: removing bkpt. "
1410 "stopping all threads momentarily.\n");
1412 stop_all_lwps (1, lwp);
1413 cancel_breakpoints ();
1415 delete_breakpoint (lwp->exit_jump_pad_bkpt);
1416 lwp->exit_jump_pad_bkpt = NULL;
1418 unstop_all_lwps (1, lwp);
1420 gdb_assert (lwp->suspended >= 0);
1427 Checking whether LWP %ld needs to move out of the jump pad...no\n",
1430 current_inferior = saved_inferior;
1434 /* Enqueue one signal in the "signals to report later when out of the
1438 enqueue_one_deferred_signal (struct lwp_info *lwp, int *wstat)
1440 struct pending_signals *p_sig;
1444 Deferring signal %d for LWP %ld.\n", WSTOPSIG (*wstat), lwpid_of (lwp));
1448 struct pending_signals *sig;
1450 for (sig = lwp->pending_signals_to_report;
1454 " Already queued %d\n",
1457 fprintf (stderr, " (no more currently queued signals)\n");
1460 /* Don't enqueue non-RT signals if they are already in the deferred
1461 queue. (SIGSTOP being the easiest signal to see ending up here
1463 if (WSTOPSIG (*wstat) < __SIGRTMIN)
1465 struct pending_signals *sig;
1467 for (sig = lwp->pending_signals_to_report;
1471 if (sig->signal == WSTOPSIG (*wstat))
1475 "Not requeuing already queued non-RT signal %d"
1484 p_sig = xmalloc (sizeof (*p_sig));
1485 p_sig->prev = lwp->pending_signals_to_report;
1486 p_sig->signal = WSTOPSIG (*wstat);
1487 memset (&p_sig->info, 0, sizeof (siginfo_t));
1488 ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info);
1490 lwp->pending_signals_to_report = p_sig;
1493 /* Dequeue one signal from the "signals to report later when out of
1494 the jump pad" list. */
1497 dequeue_one_deferred_signal (struct lwp_info *lwp, int *wstat)
1499 if (lwp->pending_signals_to_report != NULL)
1501 struct pending_signals **p_sig;
1503 p_sig = &lwp->pending_signals_to_report;
1504 while ((*p_sig)->prev != NULL)
1505 p_sig = &(*p_sig)->prev;
1507 *wstat = W_STOPCODE ((*p_sig)->signal);
1508 if ((*p_sig)->info.si_signo != 0)
1509 ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &(*p_sig)->info);
1514 fprintf (stderr, "Reporting deferred signal %d for LWP %ld.\n",
1515 WSTOPSIG (*wstat), lwpid_of (lwp));
1519 struct pending_signals *sig;
1521 for (sig = lwp->pending_signals_to_report;
1525 " Still queued %d\n",
1528 fprintf (stderr, " (no more queued signals)\n");
1537 /* Arrange for a breakpoint to be hit again later. We don't keep the
1538 SIGTRAP status and don't forward the SIGTRAP signal to the LWP. We
1539 will handle the current event, eventually we will resume this LWP,
1540 and this breakpoint will trap again. */
1543 cancel_breakpoint (struct lwp_info *lwp)
1545 struct thread_info *saved_inferior;
1547 /* There's nothing to do if we don't support breakpoints. */
1548 if (!supports_breakpoints ())
1551 /* breakpoint_at reads from current inferior. */
1552 saved_inferior = current_inferior;
1553 current_inferior = get_lwp_thread (lwp);
1555 if ((*the_low_target.breakpoint_at) (lwp->stop_pc))
1559 "CB: Push back breakpoint for %s\n",
1560 target_pid_to_str (ptid_of (lwp)));
1562 /* Back up the PC if necessary. */
1563 if (the_low_target.decr_pc_after_break)
1565 struct regcache *regcache
1566 = get_thread_regcache (current_inferior, 1);
1567 (*the_low_target.set_pc) (regcache, lwp->stop_pc);
1570 current_inferior = saved_inferior;
1577 "CB: No breakpoint found at %s for [%s]\n",
1578 paddress (lwp->stop_pc),
1579 target_pid_to_str (ptid_of (lwp)));
1582 current_inferior = saved_inferior;
1586 /* When the event-loop is doing a step-over, this points at the thread
1588 ptid_t step_over_bkpt;
1590 /* Wait for an event from child PID. If PID is -1, wait for any
1591 child. Store the stop status through the status pointer WSTAT.
1592 OPTIONS is passed to the waitpid call. Return 0 if no child stop
1593 event was found and OPTIONS contains WNOHANG. Return the PID of
1594 the stopped child otherwise. */
1597 linux_wait_for_event (ptid_t ptid, int *wstat, int options)
1599 struct lwp_info *event_child, *requested_child;
1603 requested_child = NULL;
1605 /* Check for a lwp with a pending status. */
1607 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
1609 event_child = (struct lwp_info *)
1610 find_inferior (&all_lwps, status_pending_p_callback, &ptid);
1611 if (debug_threads && event_child)
1612 fprintf (stderr, "Got a pending child %ld\n", lwpid_of (event_child));
1616 requested_child = find_lwp_pid (ptid);
1618 if (!stopping_threads
1619 && requested_child->status_pending_p
1620 && requested_child->collecting_fast_tracepoint)
1622 enqueue_one_deferred_signal (requested_child,
1623 &requested_child->status_pending);
1624 requested_child->status_pending_p = 0;
1625 requested_child->status_pending = 0;
1626 linux_resume_one_lwp (requested_child, 0, 0, NULL);
1629 if (requested_child->suspended
1630 && requested_child->status_pending_p)
1631 fatal ("requesting an event out of a suspended child?");
1633 if (requested_child->status_pending_p)
1634 event_child = requested_child;
1637 if (event_child != NULL)
1640 fprintf (stderr, "Got an event from pending child %ld (%04x)\n",
1641 lwpid_of (event_child), event_child->status_pending);
1642 *wstat = event_child->status_pending;
1643 event_child->status_pending_p = 0;
1644 event_child->status_pending = 0;
1645 current_inferior = get_lwp_thread (event_child);
1646 return lwpid_of (event_child);
1649 if (ptid_is_pid (ptid))
1651 /* A request to wait for a specific tgid. This is not possible
1652 with waitpid, so instead, we wait for any child, and leave
1653 children we're not interested in right now with a pending
1654 status to report later. */
1655 wait_ptid = minus_one_ptid;
1660 /* We only enter this loop if no process has a pending wait status. Thus
1661 any action taken in response to a wait status inside this loop is
1662 responding as soon as we detect the status, not after any pending
1666 event_child = linux_wait_for_lwp (wait_ptid, wstat, options);
1668 if ((options & WNOHANG) && event_child == NULL)
1671 fprintf (stderr, "WNOHANG set, no event found\n");
1675 if (event_child == NULL)
1676 error ("event from unknown child");
1678 if (ptid_is_pid (ptid)
1679 && ptid_get_pid (ptid) != ptid_get_pid (ptid_of (event_child)))
1681 if (! WIFSTOPPED (*wstat))
1682 mark_lwp_dead (event_child, *wstat);
1685 event_child->status_pending_p = 1;
1686 event_child->status_pending = *wstat;
1691 current_inferior = get_lwp_thread (event_child);
1693 /* Check for thread exit. */
1694 if (! WIFSTOPPED (*wstat))
1697 fprintf (stderr, "LWP %ld exiting\n", lwpid_of (event_child));
1699 /* If the last thread is exiting, just return. */
1700 if (last_thread_of_process_p (current_inferior))
1703 fprintf (stderr, "LWP %ld is last lwp of process\n",
1704 lwpid_of (event_child));
1705 return lwpid_of (event_child);
1710 current_inferior = (struct thread_info *) all_threads.head;
1712 fprintf (stderr, "Current inferior is now %ld\n",
1713 lwpid_of (get_thread_lwp (current_inferior)));
1717 current_inferior = NULL;
1719 fprintf (stderr, "Current inferior is now <NULL>\n");
1722 /* If we were waiting for this particular child to do something...
1723 well, it did something. */
1724 if (requested_child != NULL)
1726 int lwpid = lwpid_of (event_child);
1728 /* Cancel the step-over operation --- the thread that
1729 started it is gone. */
1730 if (finish_step_over (event_child))
1731 unstop_all_lwps (1, event_child);
1732 delete_lwp (event_child);
1736 delete_lwp (event_child);
1738 /* Wait for a more interesting event. */
1742 if (event_child->must_set_ptrace_flags)
1744 linux_enable_event_reporting (lwpid_of (event_child));
1745 event_child->must_set_ptrace_flags = 0;
1748 if (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) == SIGTRAP
1749 && *wstat >> 16 != 0)
1751 handle_extended_wait (event_child, *wstat);
1755 if (WIFSTOPPED (*wstat)
1756 && WSTOPSIG (*wstat) == SIGSTOP
1757 && event_child->stop_expected)
1762 fprintf (stderr, "Expected stop.\n");
1763 event_child->stop_expected = 0;
1765 should_stop = (current_inferior->last_resume_kind == resume_stop
1766 || stopping_threads);
1770 linux_resume_one_lwp (event_child,
1771 event_child->stepping, 0, NULL);
1776 return lwpid_of (event_child);
1783 /* Count the LWP's that have had events. */
1786 count_events_callback (struct inferior_list_entry *entry, void *data)
1788 struct lwp_info *lp = (struct lwp_info *) entry;
1789 struct thread_info *thread = get_lwp_thread (lp);
1792 gdb_assert (count != NULL);
1794 /* Count only resumed LWPs that have a SIGTRAP event pending that
1795 should be reported to GDB. */
1796 if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
1797 && thread->last_resume_kind != resume_stop
1798 && lp->status_pending_p
1799 && WIFSTOPPED (lp->status_pending)
1800 && WSTOPSIG (lp->status_pending) == SIGTRAP
1801 && !breakpoint_inserted_here (lp->stop_pc))
1807 /* Select the LWP (if any) that is currently being single-stepped. */
1810 select_singlestep_lwp_callback (struct inferior_list_entry *entry, void *data)
1812 struct lwp_info *lp = (struct lwp_info *) entry;
1813 struct thread_info *thread = get_lwp_thread (lp);
1815 if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
1816 && thread->last_resume_kind == resume_step
1817 && lp->status_pending_p)
1823 /* Select the Nth LWP that has had a SIGTRAP event that should be
1827 select_event_lwp_callback (struct inferior_list_entry *entry, void *data)
1829 struct lwp_info *lp = (struct lwp_info *) entry;
1830 struct thread_info *thread = get_lwp_thread (lp);
1831 int *selector = data;
1833 gdb_assert (selector != NULL);
1835 /* Select only resumed LWPs that have a SIGTRAP event pending. */
1836 if (thread->last_resume_kind != resume_stop
1837 && thread->last_status.kind == TARGET_WAITKIND_IGNORE
1838 && lp->status_pending_p
1839 && WIFSTOPPED (lp->status_pending)
1840 && WSTOPSIG (lp->status_pending) == SIGTRAP
1841 && !breakpoint_inserted_here (lp->stop_pc))
1842 if ((*selector)-- == 0)
1849 cancel_breakpoints_callback (struct inferior_list_entry *entry, void *data)
1851 struct lwp_info *lp = (struct lwp_info *) entry;
1852 struct thread_info *thread = get_lwp_thread (lp);
1853 struct lwp_info *event_lp = data;
1855 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
1859 /* If a LWP other than the LWP that we're reporting an event for has
1860 hit a GDB breakpoint (as opposed to some random trap signal),
1861 then just arrange for it to hit it again later. We don't keep
1862 the SIGTRAP status and don't forward the SIGTRAP signal to the
1863 LWP. We will handle the current event, eventually we will resume
1864 all LWPs, and this one will get its breakpoint trap again.
1866 If we do not do this, then we run the risk that the user will
1867 delete or disable the breakpoint, but the LWP will have already
1870 if (thread->last_resume_kind != resume_stop
1871 && thread->last_status.kind == TARGET_WAITKIND_IGNORE
1872 && lp->status_pending_p
1873 && WIFSTOPPED (lp->status_pending)
1874 && WSTOPSIG (lp->status_pending) == SIGTRAP
1876 && !lp->stopped_by_watchpoint
1877 && cancel_breakpoint (lp))
1878 /* Throw away the SIGTRAP. */
1879 lp->status_pending_p = 0;
1885 linux_cancel_breakpoints (void)
1887 find_inferior (&all_lwps, cancel_breakpoints_callback, NULL);
1890 /* Select one LWP out of those that have events pending. */
1893 select_event_lwp (struct lwp_info **orig_lp)
1896 int random_selector;
1897 struct lwp_info *event_lp;
1899 /* Give preference to any LWP that is being single-stepped. */
1901 = (struct lwp_info *) find_inferior (&all_lwps,
1902 select_singlestep_lwp_callback, NULL);
1903 if (event_lp != NULL)
1907 "SEL: Select single-step %s\n",
1908 target_pid_to_str (ptid_of (event_lp)));
1912 /* No single-stepping LWP. Select one at random, out of those
1913 which have had SIGTRAP events. */
1915 /* First see how many SIGTRAP events we have. */
1916 find_inferior (&all_lwps, count_events_callback, &num_events);
1918 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
1919 random_selector = (int)
1920 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
1922 if (debug_threads && num_events > 1)
1924 "SEL: Found %d SIGTRAP events, selecting #%d\n",
1925 num_events, random_selector);
1927 event_lp = (struct lwp_info *) find_inferior (&all_lwps,
1928 select_event_lwp_callback,
1932 if (event_lp != NULL)
1934 /* Switch the event LWP. */
1935 *orig_lp = event_lp;
1939 /* Decrement the suspend count of an LWP. */
1942 unsuspend_one_lwp (struct inferior_list_entry *entry, void *except)
1944 struct lwp_info *lwp = (struct lwp_info *) entry;
1946 /* Ignore EXCEPT. */
1952 gdb_assert (lwp->suspended >= 0);
1956 /* Decrement the suspend count of all LWPs, except EXCEPT, if non
1960 unsuspend_all_lwps (struct lwp_info *except)
1962 find_inferior (&all_lwps, unsuspend_one_lwp, except);
1965 static void move_out_of_jump_pad_callback (struct inferior_list_entry *entry);
1966 static int stuck_in_jump_pad_callback (struct inferior_list_entry *entry,
1968 static int lwp_running (struct inferior_list_entry *entry, void *data);
1969 static ptid_t linux_wait_1 (ptid_t ptid,
1970 struct target_waitstatus *ourstatus,
1971 int target_options);
1973 /* Stabilize threads (move out of jump pads).
1975 If a thread is midway collecting a fast tracepoint, we need to
1976 finish the collection and move it out of the jump pad before
1977 reporting the signal.
1979 This avoids recursion while collecting (when a signal arrives
1980 midway, and the signal handler itself collects), which would trash
1981 the trace buffer. In case the user set a breakpoint in a signal
1982 handler, this avoids the backtrace showing the jump pad, etc..
1983 Most importantly, there are certain things we can't do safely if
1984 threads are stopped in a jump pad (or in its callee's). For
1987 - starting a new trace run. A thread still collecting the
1988 previous run, could trash the trace buffer when resumed. The trace
1989 buffer control structures would have been reset but the thread had
1990 no way to tell. The thread could even midway memcpy'ing to the
1991 buffer, which would mean that when resumed, it would clobber the
1992 trace buffer that had been set for a new run.
1994 - we can't rewrite/reuse the jump pads for new tracepoints
1995 safely. Say you do tstart while a thread is stopped midway while
1996 collecting. When the thread is later resumed, it finishes the
1997 collection, and returns to the jump pad, to execute the original
1998 instruction that was under the tracepoint jump at the time the
1999 older run had been started. If the jump pad had been rewritten
2000 since for something else in the new run, the thread would now
2001 execute the wrong / random instructions. */
2004 linux_stabilize_threads (void)
2006 struct thread_info *save_inferior;
2007 struct lwp_info *lwp_stuck;
2010 = (struct lwp_info *) find_inferior (&all_lwps,
2011 stuck_in_jump_pad_callback, NULL);
2012 if (lwp_stuck != NULL)
2015 fprintf (stderr, "can't stabilize, LWP %ld is stuck in jump pad\n",
2016 lwpid_of (lwp_stuck));
2020 save_inferior = current_inferior;
2022 stabilizing_threads = 1;
2025 for_each_inferior (&all_lwps, move_out_of_jump_pad_callback);
2027 /* Loop until all are stopped out of the jump pads. */
2028 while (find_inferior (&all_lwps, lwp_running, NULL) != NULL)
2030 struct target_waitstatus ourstatus;
2031 struct lwp_info *lwp;
2034 /* Note that we go through the full wait even loop. While
2035 moving threads out of jump pad, we need to be able to step
2036 over internal breakpoints and such. */
2037 linux_wait_1 (minus_one_ptid, &ourstatus, 0);
2039 if (ourstatus.kind == TARGET_WAITKIND_STOPPED)
2041 lwp = get_thread_lwp (current_inferior);
2046 if (ourstatus.value.sig != TARGET_SIGNAL_0
2047 || current_inferior->last_resume_kind == resume_stop)
2049 wstat = W_STOPCODE (target_signal_to_host (ourstatus.value.sig));
2050 enqueue_one_deferred_signal (lwp, &wstat);
2055 find_inferior (&all_lwps, unsuspend_one_lwp, NULL);
2057 stabilizing_threads = 0;
2059 current_inferior = save_inferior;
2064 = (struct lwp_info *) find_inferior (&all_lwps,
2065 stuck_in_jump_pad_callback, NULL);
2066 if (lwp_stuck != NULL)
2067 fprintf (stderr, "couldn't stabilize, LWP %ld got stuck in jump pad\n",
2068 lwpid_of (lwp_stuck));
2072 /* Wait for process, returns status. */
2075 linux_wait_1 (ptid_t ptid,
2076 struct target_waitstatus *ourstatus, int target_options)
2079 struct lwp_info *event_child;
2082 int step_over_finished;
2083 int bp_explains_trap;
2084 int maybe_internal_trap;
2088 /* Translate generic target options into linux options. */
2090 if (target_options & TARGET_WNOHANG)
2094 bp_explains_trap = 0;
2096 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2098 /* If we were only supposed to resume one thread, only wait for
2099 that thread - if it's still alive. If it died, however - which
2100 can happen if we're coming from the thread death case below -
2101 then we need to make sure we restart the other threads. We could
2102 pick a thread at random or restart all; restarting all is less
2105 && !ptid_equal (cont_thread, null_ptid)
2106 && !ptid_equal (cont_thread, minus_one_ptid))
2108 struct thread_info *thread;
2110 thread = (struct thread_info *) find_inferior_id (&all_threads,
2113 /* No stepping, no signal - unless one is pending already, of course. */
2116 struct thread_resume resume_info;
2117 resume_info.thread = minus_one_ptid;
2118 resume_info.kind = resume_continue;
2119 resume_info.sig = 0;
2120 linux_resume (&resume_info, 1);
2126 if (ptid_equal (step_over_bkpt, null_ptid))
2127 pid = linux_wait_for_event (ptid, &w, options);
2131 fprintf (stderr, "step_over_bkpt set [%s], doing a blocking wait\n",
2132 target_pid_to_str (step_over_bkpt));
2133 pid = linux_wait_for_event (step_over_bkpt, &w, options & ~WNOHANG);
2136 if (pid == 0) /* only if TARGET_WNOHANG */
2139 event_child = get_thread_lwp (current_inferior);
2141 /* If we are waiting for a particular child, and it exited,
2142 linux_wait_for_event will return its exit status. Similarly if
2143 the last child exited. If this is not the last child, however,
2144 do not report it as exited until there is a 'thread exited' response
2145 available in the remote protocol. Instead, just wait for another event.
2146 This should be safe, because if the thread crashed we will already
2147 have reported the termination signal to GDB; that should stop any
2148 in-progress stepping operations, etc.
2150 Report the exit status of the last thread to exit. This matches
2151 LinuxThreads' behavior. */
2153 if (last_thread_of_process_p (current_inferior))
2155 if (WIFEXITED (w) || WIFSIGNALED (w))
2159 ourstatus->kind = TARGET_WAITKIND_EXITED;
2160 ourstatus->value.integer = WEXITSTATUS (w);
2164 "\nChild exited with retcode = %x \n",
2169 ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
2170 ourstatus->value.sig = target_signal_from_host (WTERMSIG (w));
2174 "\nChild terminated with signal = %x \n",
2179 return ptid_of (event_child);
2184 if (!WIFSTOPPED (w))
2188 /* If this event was not handled before, and is not a SIGTRAP, we
2189 report it. SIGILL and SIGSEGV are also treated as traps in case
2190 a breakpoint is inserted at the current PC. If this target does
2191 not support internal breakpoints at all, we also report the
2192 SIGTRAP without further processing; it's of no concern to us. */
2194 = (supports_breakpoints ()
2195 && (WSTOPSIG (w) == SIGTRAP
2196 || ((WSTOPSIG (w) == SIGILL
2197 || WSTOPSIG (w) == SIGSEGV)
2198 && (*the_low_target.breakpoint_at) (event_child->stop_pc))));
2200 if (maybe_internal_trap)
2202 /* Handle anything that requires bookkeeping before deciding to
2203 report the event or continue waiting. */
2205 /* First check if we can explain the SIGTRAP with an internal
2206 breakpoint, or if we should possibly report the event to GDB.
2207 Do this before anything that may remove or insert a
2209 bp_explains_trap = breakpoint_inserted_here (event_child->stop_pc);
2211 /* We have a SIGTRAP, possibly a step-over dance has just
2212 finished. If so, tweak the state machine accordingly,
2213 reinsert breakpoints and delete any reinsert (software
2214 single-step) breakpoints. */
2215 step_over_finished = finish_step_over (event_child);
2217 /* Now invoke the callbacks of any internal breakpoints there. */
2218 check_breakpoints (event_child->stop_pc);
2220 /* Handle tracepoint data collecting. This may overflow the
2221 trace buffer, and cause a tracing stop, removing
2223 trace_event = handle_tracepoints (event_child);
2225 if (bp_explains_trap)
2227 /* If we stepped or ran into an internal breakpoint, we've
2228 already handled it. So next time we resume (from this
2229 PC), we should step over it. */
2231 fprintf (stderr, "Hit a gdbserver breakpoint.\n");
2233 if (breakpoint_here (event_child->stop_pc))
2234 event_child->need_step_over = 1;
2239 /* We have some other signal, possibly a step-over dance was in
2240 progress, and it should be cancelled too. */
2241 step_over_finished = finish_step_over (event_child);
2244 /* We have all the data we need. Either report the event to GDB, or
2245 resume threads and keep waiting for more. */
2247 /* If we're collecting a fast tracepoint, finish the collection and
2248 move out of the jump pad before delivering a signal. See
2249 linux_stabilize_threads. */
2252 && WSTOPSIG (w) != SIGTRAP
2253 && supports_fast_tracepoints ()
2254 && in_process_agent_loaded ())
2258 "Got signal %d for LWP %ld. Check if we need "
2259 "to defer or adjust it.\n",
2260 WSTOPSIG (w), lwpid_of (event_child));
2262 /* Allow debugging the jump pad itself. */
2263 if (current_inferior->last_resume_kind != resume_step
2264 && maybe_move_out_of_jump_pad (event_child, &w))
2266 enqueue_one_deferred_signal (event_child, &w);
2270 "Signal %d for LWP %ld deferred (in jump pad)\n",
2271 WSTOPSIG (w), lwpid_of (event_child));
2273 linux_resume_one_lwp (event_child, 0, 0, NULL);
2278 if (event_child->collecting_fast_tracepoint)
2282 LWP %ld was trying to move out of the jump pad (%d). \
2283 Check if we're already there.\n",
2284 lwpid_of (event_child),
2285 event_child->collecting_fast_tracepoint);
2289 event_child->collecting_fast_tracepoint
2290 = linux_fast_tracepoint_collecting (event_child, NULL);
2292 if (event_child->collecting_fast_tracepoint != 1)
2294 /* No longer need this breakpoint. */
2295 if (event_child->exit_jump_pad_bkpt != NULL)
2299 "No longer need exit-jump-pad bkpt; removing it."
2300 "stopping all threads momentarily.\n");
2302 /* Other running threads could hit this breakpoint.
2303 We don't handle moribund locations like GDB does,
2304 instead we always pause all threads when removing
2305 breakpoints, so that any step-over or
2306 decr_pc_after_break adjustment is always taken
2307 care of while the breakpoint is still
2309 stop_all_lwps (1, event_child);
2310 cancel_breakpoints ();
2312 delete_breakpoint (event_child->exit_jump_pad_bkpt);
2313 event_child->exit_jump_pad_bkpt = NULL;
2315 unstop_all_lwps (1, event_child);
2317 gdb_assert (event_child->suspended >= 0);
2321 if (event_child->collecting_fast_tracepoint == 0)
2325 "fast tracepoint finished "
2326 "collecting successfully.\n");
2328 /* We may have a deferred signal to report. */
2329 if (dequeue_one_deferred_signal (event_child, &w))
2332 fprintf (stderr, "dequeued one signal.\n");
2337 fprintf (stderr, "no deferred signals.\n");
2339 if (stabilizing_threads)
2341 ourstatus->kind = TARGET_WAITKIND_STOPPED;
2342 ourstatus->value.sig = TARGET_SIGNAL_0;
2343 return ptid_of (event_child);
2349 /* Check whether GDB would be interested in this event. */
2351 /* If GDB is not interested in this signal, don't stop other
2352 threads, and don't report it to GDB. Just resume the inferior
2353 right away. We do this for threading-related signals as well as
2354 any that GDB specifically requested we ignore. But never ignore
2355 SIGSTOP if we sent it ourselves, and do not ignore signals when
2356 stepping - they may require special handling to skip the signal
2358 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
2361 && current_inferior->last_resume_kind != resume_step
2363 #if defined (USE_THREAD_DB) && !defined (__ANDROID__)
2364 (current_process ()->private->thread_db != NULL
2365 && (WSTOPSIG (w) == __SIGRTMIN
2366 || WSTOPSIG (w) == __SIGRTMIN + 1))
2369 (pass_signals[target_signal_from_host (WSTOPSIG (w))]
2370 && !(WSTOPSIG (w) == SIGSTOP
2371 && current_inferior->last_resume_kind == resume_stop))))
2373 siginfo_t info, *info_p;
2376 fprintf (stderr, "Ignored signal %d for LWP %ld.\n",
2377 WSTOPSIG (w), lwpid_of (event_child));
2379 if (ptrace (PTRACE_GETSIGINFO, lwpid_of (event_child), 0, &info) == 0)
2383 linux_resume_one_lwp (event_child, event_child->stepping,
2384 WSTOPSIG (w), info_p);
2388 /* If GDB wanted this thread to single step, we always want to
2389 report the SIGTRAP, and let GDB handle it. Watchpoints should
2390 always be reported. So should signals we can't explain. A
2391 SIGTRAP we can't explain could be a GDB breakpoint --- we may or
2392 not support Z0 breakpoints. If we do, we're be able to handle
2393 GDB breakpoints on top of internal breakpoints, by handling the
2394 internal breakpoint and still reporting the event to GDB. If we
2395 don't, we're out of luck, GDB won't see the breakpoint hit. */
2396 report_to_gdb = (!maybe_internal_trap
2397 || current_inferior->last_resume_kind == resume_step
2398 || event_child->stopped_by_watchpoint
2399 || (!step_over_finished
2400 && !bp_explains_trap && !trace_event)
2401 || gdb_breakpoint_here (event_child->stop_pc));
2403 /* We found no reason GDB would want us to stop. We either hit one
2404 of our own breakpoints, or finished an internal step GDB
2405 shouldn't know about. */
2410 if (bp_explains_trap)
2411 fprintf (stderr, "Hit a gdbserver breakpoint.\n");
2412 if (step_over_finished)
2413 fprintf (stderr, "Step-over finished.\n");
2415 fprintf (stderr, "Tracepoint event.\n");
2418 /* We're not reporting this breakpoint to GDB, so apply the
2419 decr_pc_after_break adjustment to the inferior's regcache
2422 if (the_low_target.set_pc != NULL)
2424 struct regcache *regcache
2425 = get_thread_regcache (get_lwp_thread (event_child), 1);
2426 (*the_low_target.set_pc) (regcache, event_child->stop_pc);
2429 /* We may have finished stepping over a breakpoint. If so,
2430 we've stopped and suspended all LWPs momentarily except the
2431 stepping one. This is where we resume them all again. We're
2432 going to keep waiting, so use proceed, which handles stepping
2433 over the next breakpoint. */
2435 fprintf (stderr, "proceeding all threads.\n");
2437 if (step_over_finished)
2438 unsuspend_all_lwps (event_child);
2440 proceed_all_lwps ();
2446 if (current_inferior->last_resume_kind == resume_step)
2447 fprintf (stderr, "GDB wanted to single-step, reporting event.\n");
2448 if (event_child->stopped_by_watchpoint)
2449 fprintf (stderr, "Stopped by watchpoint.\n");
2450 if (gdb_breakpoint_here (event_child->stop_pc))
2451 fprintf (stderr, "Stopped by GDB breakpoint.\n");
2453 fprintf (stderr, "Hit a non-gdbserver trap event.\n");
2456 /* Alright, we're going to report a stop. */
2458 if (!non_stop && !stabilizing_threads)
2460 /* In all-stop, stop all threads. */
2461 stop_all_lwps (0, NULL);
2463 /* If we're not waiting for a specific LWP, choose an event LWP
2464 from among those that have had events. Giving equal priority
2465 to all LWPs that have had events helps prevent
2467 if (ptid_equal (ptid, minus_one_ptid))
2469 event_child->status_pending_p = 1;
2470 event_child->status_pending = w;
2472 select_event_lwp (&event_child);
2474 event_child->status_pending_p = 0;
2475 w = event_child->status_pending;
2478 /* Now that we've selected our final event LWP, cancel any
2479 breakpoints in other LWPs that have hit a GDB breakpoint.
2480 See the comment in cancel_breakpoints_callback to find out
2482 find_inferior (&all_lwps, cancel_breakpoints_callback, event_child);
2484 /* Stabilize threads (move out of jump pads). */
2485 stabilize_threads ();
2489 /* If we just finished a step-over, then all threads had been
2490 momentarily paused. In all-stop, that's fine, we want
2491 threads stopped by now anyway. In non-stop, we need to
2492 re-resume threads that GDB wanted to be running. */
2493 if (step_over_finished)
2494 unstop_all_lwps (1, event_child);
2497 ourstatus->kind = TARGET_WAITKIND_STOPPED;
2499 if (current_inferior->last_resume_kind == resume_stop
2500 && WSTOPSIG (w) == SIGSTOP)
2502 /* A thread that has been requested to stop by GDB with vCont;t,
2503 and it stopped cleanly, so report as SIG0. The use of
2504 SIGSTOP is an implementation detail. */
2505 ourstatus->value.sig = TARGET_SIGNAL_0;
2507 else if (current_inferior->last_resume_kind == resume_stop
2508 && WSTOPSIG (w) != SIGSTOP)
2510 /* A thread that has been requested to stop by GDB with vCont;t,
2511 but, it stopped for other reasons. */
2512 ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
2516 ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
2519 gdb_assert (ptid_equal (step_over_bkpt, null_ptid));
2522 fprintf (stderr, "linux_wait ret = %s, %d, %d\n",
2523 target_pid_to_str (ptid_of (event_child)),
2525 ourstatus->value.sig);
2527 return ptid_of (event_child);
2530 /* Get rid of any pending event in the pipe. */
2532 async_file_flush (void)
2538 ret = read (linux_event_pipe[0], &buf, 1);
2539 while (ret >= 0 || (ret == -1 && errno == EINTR));
2542 /* Put something in the pipe, so the event loop wakes up. */
2544 async_file_mark (void)
2548 async_file_flush ();
2551 ret = write (linux_event_pipe[1], "+", 1);
2552 while (ret == 0 || (ret == -1 && errno == EINTR));
2554 /* Ignore EAGAIN. If the pipe is full, the event loop will already
2555 be awakened anyway. */
2559 linux_wait (ptid_t ptid,
2560 struct target_waitstatus *ourstatus, int target_options)
2565 fprintf (stderr, "linux_wait: [%s]\n", target_pid_to_str (ptid));
2567 /* Flush the async file first. */
2568 if (target_is_async_p ())
2569 async_file_flush ();
2571 event_ptid = linux_wait_1 (ptid, ourstatus, target_options);
2573 /* If at least one stop was reported, there may be more. A single
2574 SIGCHLD can signal more than one child stop. */
2575 if (target_is_async_p ()
2576 && (target_options & TARGET_WNOHANG) != 0
2577 && !ptid_equal (event_ptid, null_ptid))
2583 /* Send a signal to an LWP. */
2586 kill_lwp (unsigned long lwpid, int signo)
2588 /* Use tkill, if possible, in case we are using nptl threads. If tkill
2589 fails, then we are not using nptl threads and we should be using kill. */
2593 static int tkill_failed;
2600 ret = syscall (__NR_tkill, lwpid, signo);
2601 if (errno != ENOSYS)
2608 return kill (lwpid, signo);
2612 linux_stop_lwp (struct lwp_info *lwp)
2618 send_sigstop (struct lwp_info *lwp)
2622 pid = lwpid_of (lwp);
2624 /* If we already have a pending stop signal for this process, don't
2626 if (lwp->stop_expected)
2629 fprintf (stderr, "Have pending sigstop for lwp %d\n", pid);
2635 fprintf (stderr, "Sending sigstop to lwp %d\n", pid);
2637 lwp->stop_expected = 1;
2638 kill_lwp (pid, SIGSTOP);
2642 send_sigstop_callback (struct inferior_list_entry *entry, void *except)
2644 struct lwp_info *lwp = (struct lwp_info *) entry;
2646 /* Ignore EXCEPT. */
2657 /* Increment the suspend count of an LWP, and stop it, if not stopped
2660 suspend_and_send_sigstop_callback (struct inferior_list_entry *entry,
2663 struct lwp_info *lwp = (struct lwp_info *) entry;
2665 /* Ignore EXCEPT. */
2671 return send_sigstop_callback (entry, except);
2675 mark_lwp_dead (struct lwp_info *lwp, int wstat)
2677 /* It's dead, really. */
2680 /* Store the exit status for later. */
2681 lwp->status_pending_p = 1;
2682 lwp->status_pending = wstat;
2684 /* Prevent trying to stop it. */
2687 /* No further stops are expected from a dead lwp. */
2688 lwp->stop_expected = 0;
2692 wait_for_sigstop (struct inferior_list_entry *entry)
2694 struct lwp_info *lwp = (struct lwp_info *) entry;
2695 struct thread_info *saved_inferior;
2704 fprintf (stderr, "wait_for_sigstop: LWP %ld already stopped\n",
2709 saved_inferior = current_inferior;
2710 if (saved_inferior != NULL)
2711 saved_tid = ((struct inferior_list_entry *) saved_inferior)->id;
2713 saved_tid = null_ptid; /* avoid bogus unused warning */
2715 ptid = lwp->head.id;
2718 fprintf (stderr, "wait_for_sigstop: pulling one event\n");
2720 pid = linux_wait_for_event (ptid, &wstat, __WALL);
2722 /* If we stopped with a non-SIGSTOP signal, save it for later
2723 and record the pending SIGSTOP. If the process exited, just
2725 if (WIFSTOPPED (wstat))
2728 fprintf (stderr, "LWP %ld stopped with signal %d\n",
2729 lwpid_of (lwp), WSTOPSIG (wstat));
2731 if (WSTOPSIG (wstat) != SIGSTOP)
2734 fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n",
2735 lwpid_of (lwp), wstat);
2737 lwp->status_pending_p = 1;
2738 lwp->status_pending = wstat;
2744 fprintf (stderr, "Process %d exited while stopping LWPs\n", pid);
2746 lwp = find_lwp_pid (pid_to_ptid (pid));
2749 /* Leave this status pending for the next time we're able to
2750 report it. In the mean time, we'll report this lwp as
2751 dead to GDB, so GDB doesn't try to read registers and
2752 memory from it. This can only happen if this was the
2753 last thread of the process; otherwise, PID is removed
2754 from the thread tables before linux_wait_for_event
2756 mark_lwp_dead (lwp, wstat);
2760 if (saved_inferior == NULL || linux_thread_alive (saved_tid))
2761 current_inferior = saved_inferior;
2765 fprintf (stderr, "Previously current thread died.\n");
2769 /* We can't change the current inferior behind GDB's back,
2770 otherwise, a subsequent command may apply to the wrong
2772 current_inferior = NULL;
2776 /* Set a valid thread as current. */
2777 set_desired_inferior (0);
2782 /* Returns true if LWP ENTRY is stopped in a jump pad, and we can't
2783 move it out, because we need to report the stop event to GDB. For
2784 example, if the user puts a breakpoint in the jump pad, it's
2785 because she wants to debug it. */
2788 stuck_in_jump_pad_callback (struct inferior_list_entry *entry, void *data)
2790 struct lwp_info *lwp = (struct lwp_info *) entry;
2791 struct thread_info *thread = get_lwp_thread (lwp);
2793 gdb_assert (lwp->suspended == 0);
2794 gdb_assert (lwp->stopped);
2796 /* Allow debugging the jump pad, gdb_collect, etc.. */
2797 return (supports_fast_tracepoints ()
2798 && in_process_agent_loaded ()
2799 && (gdb_breakpoint_here (lwp->stop_pc)
2800 || lwp->stopped_by_watchpoint
2801 || thread->last_resume_kind == resume_step)
2802 && linux_fast_tracepoint_collecting (lwp, NULL));
2806 move_out_of_jump_pad_callback (struct inferior_list_entry *entry)
2808 struct lwp_info *lwp = (struct lwp_info *) entry;
2809 struct thread_info *thread = get_lwp_thread (lwp);
2812 gdb_assert (lwp->suspended == 0);
2813 gdb_assert (lwp->stopped);
2815 wstat = lwp->status_pending_p ? &lwp->status_pending : NULL;
2817 /* Allow debugging the jump pad, gdb_collect, etc. */
2818 if (!gdb_breakpoint_here (lwp->stop_pc)
2819 && !lwp->stopped_by_watchpoint
2820 && thread->last_resume_kind != resume_step
2821 && maybe_move_out_of_jump_pad (lwp, wstat))
2825 "LWP %ld needs stabilizing (in jump pad)\n",
2830 lwp->status_pending_p = 0;
2831 enqueue_one_deferred_signal (lwp, wstat);
2835 "Signal %d for LWP %ld deferred "
2837 WSTOPSIG (*wstat), lwpid_of (lwp));
2840 linux_resume_one_lwp (lwp, 0, 0, NULL);
2847 lwp_running (struct inferior_list_entry *entry, void *data)
2849 struct lwp_info *lwp = (struct lwp_info *) entry;
2858 /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
2859 If SUSPEND, then also increase the suspend count of every LWP,
2863 stop_all_lwps (int suspend, struct lwp_info *except)
2865 stopping_threads = 1;
2868 find_inferior (&all_lwps, suspend_and_send_sigstop_callback, except);
2870 find_inferior (&all_lwps, send_sigstop_callback, except);
2871 for_each_inferior (&all_lwps, wait_for_sigstop);
2872 stopping_threads = 0;
2875 /* Resume execution of the inferior process.
2876 If STEP is nonzero, single-step it.
2877 If SIGNAL is nonzero, give it that signal. */
2880 linux_resume_one_lwp (struct lwp_info *lwp,
2881 int step, int signal, siginfo_t *info)
2883 struct thread_info *saved_inferior;
2884 int fast_tp_collecting;
2886 if (lwp->stopped == 0)
2889 fast_tp_collecting = lwp->collecting_fast_tracepoint;
2891 gdb_assert (!stabilizing_threads || fast_tp_collecting);
2893 /* Cancel actions that rely on GDB not changing the PC (e.g., the
2894 user used the "jump" command, or "set $pc = foo"). */
2895 if (lwp->stop_pc != get_pc (lwp))
2897 /* Collecting 'while-stepping' actions doesn't make sense
2899 release_while_stepping_state_list (get_lwp_thread (lwp));
2902 /* If we have pending signals or status, and a new signal, enqueue the
2903 signal. Also enqueue the signal if we are waiting to reinsert a
2904 breakpoint; it will be picked up again below. */
2906 && (lwp->status_pending_p
2907 || lwp->pending_signals != NULL
2908 || lwp->bp_reinsert != 0
2909 || fast_tp_collecting))
2911 struct pending_signals *p_sig;
2912 p_sig = xmalloc (sizeof (*p_sig));
2913 p_sig->prev = lwp->pending_signals;
2914 p_sig->signal = signal;
2916 memset (&p_sig->info, 0, sizeof (siginfo_t));
2918 memcpy (&p_sig->info, info, sizeof (siginfo_t));
2919 lwp->pending_signals = p_sig;
2922 if (lwp->status_pending_p)
2925 fprintf (stderr, "Not resuming lwp %ld (%s, signal %d, stop %s);"
2926 " has pending status\n",
2927 lwpid_of (lwp), step ? "step" : "continue", signal,
2928 lwp->stop_expected ? "expected" : "not expected");
2932 saved_inferior = current_inferior;
2933 current_inferior = get_lwp_thread (lwp);
2936 fprintf (stderr, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
2937 lwpid_of (lwp), step ? "step" : "continue", signal,
2938 lwp->stop_expected ? "expected" : "not expected");
2940 /* This bit needs some thinking about. If we get a signal that
2941 we must report while a single-step reinsert is still pending,
2942 we often end up resuming the thread. It might be better to
2943 (ew) allow a stack of pending events; then we could be sure that
2944 the reinsert happened right away and not lose any signals.
2946 Making this stack would also shrink the window in which breakpoints are
2947 uninserted (see comment in linux_wait_for_lwp) but not enough for
2948 complete correctness, so it won't solve that problem. It may be
2949 worthwhile just to solve this one, however. */
2950 if (lwp->bp_reinsert != 0)
2953 fprintf (stderr, " pending reinsert at 0x%s\n",
2954 paddress (lwp->bp_reinsert));
2956 if (lwp->bp_reinsert != 0 && can_hardware_single_step ())
2958 if (fast_tp_collecting == 0)
2961 fprintf (stderr, "BAD - reinserting but not stepping.\n");
2963 fprintf (stderr, "BAD - reinserting and suspended(%d).\n",
2970 /* Postpone any pending signal. It was enqueued above. */
2974 if (fast_tp_collecting == 1)
2978 lwp %ld wants to get out of fast tracepoint jump pad (exit-jump-pad-bkpt)\n",
2981 /* Postpone any pending signal. It was enqueued above. */
2984 else if (fast_tp_collecting == 2)
2988 lwp %ld wants to get out of fast tracepoint jump pad single-stepping\n",
2991 if (can_hardware_single_step ())
2994 fatal ("moving out of jump pad single-stepping"
2995 " not implemented on this target");
2997 /* Postpone any pending signal. It was enqueued above. */
3001 /* If we have while-stepping actions in this thread set it stepping.
3002 If we have a signal to deliver, it may or may not be set to
3003 SIG_IGN, we don't know. Assume so, and allow collecting
3004 while-stepping into a signal handler. A possible smart thing to
3005 do would be to set an internal breakpoint at the signal return
3006 address, continue, and carry on catching this while-stepping
3007 action only when that breakpoint is hit. A future
3009 if (get_lwp_thread (lwp)->while_stepping != NULL
3010 && can_hardware_single_step ())
3014 "lwp %ld has a while-stepping action -> forcing step.\n",
3019 if (debug_threads && the_low_target.get_pc != NULL)
3021 struct regcache *regcache = get_thread_regcache (current_inferior, 1);
3022 CORE_ADDR pc = (*the_low_target.get_pc) (regcache);
3023 fprintf (stderr, " resuming from pc 0x%lx\n", (long) pc);
3026 /* If we have pending signals, consume one unless we are trying to
3027 reinsert a breakpoint or we're trying to finish a fast tracepoint
3029 if (lwp->pending_signals != NULL
3030 && lwp->bp_reinsert == 0
3031 && fast_tp_collecting == 0)
3033 struct pending_signals **p_sig;
3035 p_sig = &lwp->pending_signals;
3036 while ((*p_sig)->prev != NULL)
3037 p_sig = &(*p_sig)->prev;
3039 signal = (*p_sig)->signal;
3040 if ((*p_sig)->info.si_signo != 0)
3041 ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &(*p_sig)->info);
3047 if (the_low_target.prepare_to_resume != NULL)
3048 the_low_target.prepare_to_resume (lwp);
3050 regcache_invalidate_one ((struct inferior_list_entry *)
3051 get_lwp_thread (lwp));
3054 lwp->stopped_by_watchpoint = 0;
3055 lwp->stepping = step;
3056 ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (lwp), 0,
3057 /* Coerce to a uintptr_t first to avoid potential gcc warning
3058 of coercing an 8 byte integer to a 4 byte pointer. */
3059 (PTRACE_ARG4_TYPE) (uintptr_t) signal);
3061 current_inferior = saved_inferior;
3064 /* ESRCH from ptrace either means that the thread was already
3065 running (an error) or that it is gone (a race condition). If
3066 it's gone, we will get a notification the next time we wait,
3067 so we can ignore the error. We could differentiate these
3068 two, but it's tricky without waiting; the thread still exists
3069 as a zombie, so sending it signal 0 would succeed. So just
3074 perror_with_name ("ptrace");
3078 struct thread_resume_array
3080 struct thread_resume *resume;
3084 /* This function is called once per thread. We look up the thread
3085 in RESUME_PTR, and mark the thread with a pointer to the appropriate
3088 This algorithm is O(threads * resume elements), but resume elements
3089 is small (and will remain small at least until GDB supports thread
3092 linux_set_resume_request (struct inferior_list_entry *entry, void *arg)
3094 struct lwp_info *lwp;
3095 struct thread_info *thread;
3097 struct thread_resume_array *r;
3099 thread = (struct thread_info *) entry;
3100 lwp = get_thread_lwp (thread);
3103 for (ndx = 0; ndx < r->n; ndx++)
3105 ptid_t ptid = r->resume[ndx].thread;
3106 if (ptid_equal (ptid, minus_one_ptid)
3107 || ptid_equal (ptid, entry->id)
3108 || (ptid_is_pid (ptid)
3109 && (ptid_get_pid (ptid) == pid_of (lwp)))
3110 || (ptid_get_lwp (ptid) == -1
3111 && (ptid_get_pid (ptid) == pid_of (lwp))))
3113 if (r->resume[ndx].kind == resume_stop
3114 && thread->last_resume_kind == resume_stop)
3117 fprintf (stderr, "already %s LWP %ld at GDB's request\n",
3118 thread->last_status.kind == TARGET_WAITKIND_STOPPED
3126 lwp->resume = &r->resume[ndx];
3127 thread->last_resume_kind = lwp->resume->kind;
3129 /* If we had a deferred signal to report, dequeue one now.
3130 This can happen if LWP gets more than one signal while
3131 trying to get out of a jump pad. */
3133 && !lwp->status_pending_p
3134 && dequeue_one_deferred_signal (lwp, &lwp->status_pending))
3136 lwp->status_pending_p = 1;
3140 "Dequeueing deferred signal %d for LWP %ld, "
3141 "leaving status pending.\n",
3142 WSTOPSIG (lwp->status_pending), lwpid_of (lwp));
3149 /* No resume action for this thread. */
3156 /* Set *FLAG_P if this lwp has an interesting status pending. */
3158 resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p)
3160 struct lwp_info *lwp = (struct lwp_info *) entry;
3162 /* LWPs which will not be resumed are not interesting, because
3163 we might not wait for them next time through linux_wait. */
3164 if (lwp->resume == NULL)
3167 if (lwp->status_pending_p)
3168 * (int *) flag_p = 1;
3173 /* Return 1 if this lwp that GDB wants running is stopped at an
3174 internal breakpoint that we need to step over. It assumes that any
3175 required STOP_PC adjustment has already been propagated to the
3176 inferior's regcache. */
3179 need_step_over_p (struct inferior_list_entry *entry, void *dummy)
3181 struct lwp_info *lwp = (struct lwp_info *) entry;
3182 struct thread_info *thread;
3183 struct thread_info *saved_inferior;
3186 /* LWPs which will not be resumed are not interesting, because we
3187 might not wait for them next time through linux_wait. */
3193 "Need step over [LWP %ld]? Ignoring, not stopped\n",
3198 thread = get_lwp_thread (lwp);
3200 if (thread->last_resume_kind == resume_stop)
3204 "Need step over [LWP %ld]? Ignoring, should remain stopped\n",
3209 gdb_assert (lwp->suspended >= 0);
3215 "Need step over [LWP %ld]? Ignoring, suspended\n",
3220 if (!lwp->need_step_over)
3224 "Need step over [LWP %ld]? No\n", lwpid_of (lwp));
3227 if (lwp->status_pending_p)
3231 "Need step over [LWP %ld]? Ignoring, has pending status.\n",
3236 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
3240 /* If the PC has changed since we stopped, then don't do anything,
3241 and let the breakpoint/tracepoint be hit. This happens if, for
3242 instance, GDB handled the decr_pc_after_break subtraction itself,
3243 GDB is OOL stepping this thread, or the user has issued a "jump"
3244 command, or poked thread's registers herself. */
3245 if (pc != lwp->stop_pc)
3249 "Need step over [LWP %ld]? Cancelling, PC was changed. "
3250 "Old stop_pc was 0x%s, PC is now 0x%s\n",
3251 lwpid_of (lwp), paddress (lwp->stop_pc), paddress (pc));
3253 lwp->need_step_over = 0;
3257 saved_inferior = current_inferior;
3258 current_inferior = thread;
3260 /* We can only step over breakpoints we know about. */
3261 if (breakpoint_here (pc) || fast_tracepoint_jump_here (pc))
3263 /* Don't step over a breakpoint that GDB expects to hit
3265 if (gdb_breakpoint_here (pc))
3269 "Need step over [LWP %ld]? yes, but found"
3270 " GDB breakpoint at 0x%s; skipping step over\n",
3271 lwpid_of (lwp), paddress (pc));
3273 current_inferior = saved_inferior;
3280 "Need step over [LWP %ld]? yes, "
3281 "found breakpoint at 0x%s\n",
3282 lwpid_of (lwp), paddress (pc));
3284 /* We've found an lwp that needs stepping over --- return 1 so
3285 that find_inferior stops looking. */
3286 current_inferior = saved_inferior;
3288 /* If the step over is cancelled, this is set again. */
3289 lwp->need_step_over = 0;
3294 current_inferior = saved_inferior;
3298 "Need step over [LWP %ld]? No, no breakpoint found at 0x%s\n",
3299 lwpid_of (lwp), paddress (pc));
3304 /* Start a step-over operation on LWP. When LWP stopped at a
3305 breakpoint, to make progress, we need to remove the breakpoint out
3306 of the way. If we let other threads run while we do that, they may
3307 pass by the breakpoint location and miss hitting it. To avoid
3308 that, a step-over momentarily stops all threads while LWP is
3309 single-stepped while the breakpoint is temporarily uninserted from
3310 the inferior. When the single-step finishes, we reinsert the
3311 breakpoint, and let all threads that are supposed to be running,
3314 On targets that don't support hardware single-step, we don't
3315 currently support full software single-stepping. Instead, we only
3316 support stepping over the thread event breakpoint, by asking the
3317 low target where to place a reinsert breakpoint. Since this
3318 routine assumes the breakpoint being stepped over is a thread event
3319 breakpoint, it usually assumes the return address of the current
3320 function is a good enough place to set the reinsert breakpoint. */
3323 start_step_over (struct lwp_info *lwp)
3325 struct thread_info *saved_inferior;
3331 "Starting step-over on LWP %ld. Stopping all threads\n",
3334 stop_all_lwps (1, lwp);
3335 gdb_assert (lwp->suspended == 0);
3338 fprintf (stderr, "Done stopping all threads for step-over.\n");
3340 /* Note, we should always reach here with an already adjusted PC,
3341 either by GDB (if we're resuming due to GDB's request), or by our
3342 caller, if we just finished handling an internal breakpoint GDB
3343 shouldn't care about. */
3346 saved_inferior = current_inferior;
3347 current_inferior = get_lwp_thread (lwp);
3349 lwp->bp_reinsert = pc;
3350 uninsert_breakpoints_at (pc);
3351 uninsert_fast_tracepoint_jumps_at (pc);
3353 if (can_hardware_single_step ())
3359 CORE_ADDR raddr = (*the_low_target.breakpoint_reinsert_addr) ();
3360 set_reinsert_breakpoint (raddr);
3364 current_inferior = saved_inferior;
3366 linux_resume_one_lwp (lwp, step, 0, NULL);
3368 /* Require next event from this LWP. */
3369 step_over_bkpt = lwp->head.id;
3373 /* Finish a step-over. Reinsert the breakpoint we had uninserted in
3374 start_step_over, if still there, and delete any reinsert
3375 breakpoints we've set, on non hardware single-step targets. */
3378 finish_step_over (struct lwp_info *lwp)
3380 if (lwp->bp_reinsert != 0)
3383 fprintf (stderr, "Finished step over.\n");
3385 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
3386 may be no breakpoint to reinsert there by now. */
3387 reinsert_breakpoints_at (lwp->bp_reinsert);
3388 reinsert_fast_tracepoint_jumps_at (lwp->bp_reinsert);
3390 lwp->bp_reinsert = 0;
3392 /* Delete any software-single-step reinsert breakpoints. No
3393 longer needed. We don't have to worry about other threads
3394 hitting this trap, and later not being able to explain it,
3395 because we were stepping over a breakpoint, and we hold all
3396 threads but LWP stopped while doing that. */
3397 if (!can_hardware_single_step ())
3398 delete_reinsert_breakpoints ();
3400 step_over_bkpt = null_ptid;
3407 /* This function is called once per thread. We check the thread's resume
3408 request, which will tell us whether to resume, step, or leave the thread
3409 stopped; and what signal, if any, it should be sent.
3411 For threads which we aren't explicitly told otherwise, we preserve
3412 the stepping flag; this is used for stepping over gdbserver-placed
3415 If pending_flags was set in any thread, we queue any needed
3416 signals, since we won't actually resume. We already have a pending
3417 event to report, so we don't need to preserve any step requests;
3418 they should be re-issued if necessary. */
3421 linux_resume_one_thread (struct inferior_list_entry *entry, void *arg)
3423 struct lwp_info *lwp;
3424 struct thread_info *thread;
3426 int leave_all_stopped = * (int *) arg;
3429 thread = (struct thread_info *) entry;
3430 lwp = get_thread_lwp (thread);
3432 if (lwp->resume == NULL)
3435 if (lwp->resume->kind == resume_stop)
3438 fprintf (stderr, "resume_stop request for LWP %ld\n", lwpid_of (lwp));
3443 fprintf (stderr, "stopping LWP %ld\n", lwpid_of (lwp));
3445 /* Stop the thread, and wait for the event asynchronously,
3446 through the event loop. */
3452 fprintf (stderr, "already stopped LWP %ld\n",
3455 /* The LWP may have been stopped in an internal event that
3456 was not meant to be notified back to GDB (e.g., gdbserver
3457 breakpoint), so we should be reporting a stop event in
3460 /* If the thread already has a pending SIGSTOP, this is a
3461 no-op. Otherwise, something later will presumably resume
3462 the thread and this will cause it to cancel any pending
3463 operation, due to last_resume_kind == resume_stop. If
3464 the thread already has a pending status to report, we
3465 will still report it the next time we wait - see
3466 status_pending_p_callback. */
3468 /* If we already have a pending signal to report, then
3469 there's no need to queue a SIGSTOP, as this means we're
3470 midway through moving the LWP out of the jumppad, and we
3471 will report the pending signal as soon as that is
3473 if (lwp->pending_signals_to_report == NULL)
3477 /* For stop requests, we're done. */
3479 thread->last_status.kind = TARGET_WAITKIND_IGNORE;
3483 /* If this thread which is about to be resumed has a pending status,
3484 then don't resume any threads - we can just report the pending
3485 status. Make sure to queue any signals that would otherwise be
3486 sent. In all-stop mode, we do this decision based on if *any*
3487 thread has a pending status. If there's a thread that needs the
3488 step-over-breakpoint dance, then don't resume any other thread
3489 but that particular one. */
3490 leave_pending = (lwp->status_pending_p || leave_all_stopped);
3495 fprintf (stderr, "resuming LWP %ld\n", lwpid_of (lwp));
3497 step = (lwp->resume->kind == resume_step);
3498 linux_resume_one_lwp (lwp, step, lwp->resume->sig, NULL);
3503 fprintf (stderr, "leaving LWP %ld stopped\n", lwpid_of (lwp));
3505 /* If we have a new signal, enqueue the signal. */
3506 if (lwp->resume->sig != 0)
3508 struct pending_signals *p_sig;
3509 p_sig = xmalloc (sizeof (*p_sig));
3510 p_sig->prev = lwp->pending_signals;
3511 p_sig->signal = lwp->resume->sig;
3512 memset (&p_sig->info, 0, sizeof (siginfo_t));
3514 /* If this is the same signal we were previously stopped by,
3515 make sure to queue its siginfo. We can ignore the return
3516 value of ptrace; if it fails, we'll skip
3517 PTRACE_SETSIGINFO. */
3518 if (WIFSTOPPED (lwp->last_status)
3519 && WSTOPSIG (lwp->last_status) == lwp->resume->sig)
3520 ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info);
3522 lwp->pending_signals = p_sig;
3526 thread->last_status.kind = TARGET_WAITKIND_IGNORE;
3532 linux_resume (struct thread_resume *resume_info, size_t n)
3534 struct thread_resume_array array = { resume_info, n };
3535 struct lwp_info *need_step_over = NULL;
3537 int leave_all_stopped;
3539 find_inferior (&all_threads, linux_set_resume_request, &array);
3541 /* If there is a thread which would otherwise be resumed, which has
3542 a pending status, then don't resume any threads - we can just
3543 report the pending status. Make sure to queue any signals that
3544 would otherwise be sent. In non-stop mode, we'll apply this
3545 logic to each thread individually. We consume all pending events
3546 before considering to start a step-over (in all-stop). */
3549 find_inferior (&all_lwps, resume_status_pending_p, &any_pending);
3551 /* If there is a thread which would otherwise be resumed, which is
3552 stopped at a breakpoint that needs stepping over, then don't
3553 resume any threads - have it step over the breakpoint with all
3554 other threads stopped, then resume all threads again. Make sure
3555 to queue any signals that would otherwise be delivered or
3557 if (!any_pending && supports_breakpoints ())
3559 = (struct lwp_info *) find_inferior (&all_lwps,
3560 need_step_over_p, NULL);
3562 leave_all_stopped = (need_step_over != NULL || any_pending);
3566 if (need_step_over != NULL)
3567 fprintf (stderr, "Not resuming all, need step over\n");
3568 else if (any_pending)
3570 "Not resuming, all-stop and found "
3571 "an LWP with pending status\n");
3573 fprintf (stderr, "Resuming, no pending status or step over needed\n");
3576 /* Even if we're leaving threads stopped, queue all signals we'd
3577 otherwise deliver. */
3578 find_inferior (&all_threads, linux_resume_one_thread, &leave_all_stopped);
3581 start_step_over (need_step_over);
3584 /* This function is called once per thread. We check the thread's
3585 last resume request, which will tell us whether to resume, step, or
3586 leave the thread stopped. Any signal the client requested to be
3587 delivered has already been enqueued at this point.
3589 If any thread that GDB wants running is stopped at an internal
3590 breakpoint that needs stepping over, we start a step-over operation
3591 on that particular thread, and leave all others stopped. */
3594 proceed_one_lwp (struct inferior_list_entry *entry, void *except)
3596 struct lwp_info *lwp = (struct lwp_info *) entry;
3597 struct thread_info *thread;
3605 "proceed_one_lwp: lwp %ld\n", lwpid_of (lwp));
3610 fprintf (stderr, " LWP %ld already running\n", lwpid_of (lwp));
3614 thread = get_lwp_thread (lwp);
3616 if (thread->last_resume_kind == resume_stop
3617 && thread->last_status.kind != TARGET_WAITKIND_IGNORE)
3620 fprintf (stderr, " client wants LWP to remain %ld stopped\n",
3625 if (lwp->status_pending_p)
3628 fprintf (stderr, " LWP %ld has pending status, leaving stopped\n",
3633 gdb_assert (lwp->suspended >= 0);
3638 fprintf (stderr, " LWP %ld is suspended\n", lwpid_of (lwp));
3642 if (thread->last_resume_kind == resume_stop
3643 && lwp->pending_signals_to_report == NULL
3644 && lwp->collecting_fast_tracepoint == 0)
3646 /* We haven't reported this LWP as stopped yet (otherwise, the
3647 last_status.kind check above would catch it, and we wouldn't
3648 reach here. This LWP may have been momentarily paused by a
3649 stop_all_lwps call while handling for example, another LWP's
3650 step-over. In that case, the pending expected SIGSTOP signal
3651 that was queued at vCont;t handling time will have already
3652 been consumed by wait_for_sigstop, and so we need to requeue
3653 another one here. Note that if the LWP already has a SIGSTOP
3654 pending, this is a no-op. */
3658 "Client wants LWP %ld to stop. "
3659 "Making sure it has a SIGSTOP pending\n",
3665 step = thread->last_resume_kind == resume_step;
3666 linux_resume_one_lwp (lwp, step, 0, NULL);
3671 unsuspend_and_proceed_one_lwp (struct inferior_list_entry *entry, void *except)
3673 struct lwp_info *lwp = (struct lwp_info *) entry;
3679 gdb_assert (lwp->suspended >= 0);
3681 return proceed_one_lwp (entry, except);
3684 /* When we finish a step-over, set threads running again. If there's
3685 another thread that may need a step-over, now's the time to start
3686 it. Eventually, we'll move all threads past their breakpoints. */
3689 proceed_all_lwps (void)
3691 struct lwp_info *need_step_over;
3693 /* If there is a thread which would otherwise be resumed, which is
3694 stopped at a breakpoint that needs stepping over, then don't
3695 resume any threads - have it step over the breakpoint with all
3696 other threads stopped, then resume all threads again. */
3698 if (supports_breakpoints ())
3701 = (struct lwp_info *) find_inferior (&all_lwps,
3702 need_step_over_p, NULL);
3704 if (need_step_over != NULL)
3707 fprintf (stderr, "proceed_all_lwps: found "
3708 "thread %ld needing a step-over\n",
3709 lwpid_of (need_step_over));
3711 start_step_over (need_step_over);
3717 fprintf (stderr, "Proceeding, no step-over needed\n");
3719 find_inferior (&all_lwps, proceed_one_lwp, NULL);
3722 /* Stopped LWPs that the client wanted to be running, that don't have
3723 pending statuses, are set to run again, except for EXCEPT, if not
3724 NULL. This undoes a stop_all_lwps call. */
3727 unstop_all_lwps (int unsuspend, struct lwp_info *except)
3733 "unstopping all lwps, except=(LWP %ld)\n", lwpid_of (except));
3736 "unstopping all lwps\n");
3740 find_inferior (&all_lwps, unsuspend_and_proceed_one_lwp, except);
3742 find_inferior (&all_lwps, proceed_one_lwp, except);
3745 #ifdef HAVE_LINUX_USRREGS
3748 register_addr (int regnum)
3752 if (regnum < 0 || regnum >= the_low_target.num_regs)
3753 error ("Invalid register number %d.", regnum);
3755 addr = the_low_target.regmap[regnum];
3760 /* Fetch one register. */
3762 fetch_register (struct regcache *regcache, int regno)
3769 if (regno >= the_low_target.num_regs)
3771 if ((*the_low_target.cannot_fetch_register) (regno))
3774 regaddr = register_addr (regno);
3778 size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
3779 & -sizeof (PTRACE_XFER_TYPE));
3780 buf = alloca (size);
3782 pid = lwpid_of (get_thread_lwp (current_inferior));
3783 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
3786 *(PTRACE_XFER_TYPE *) (buf + i) =
3787 ptrace (PTRACE_PEEKUSER, pid,
3788 /* Coerce to a uintptr_t first to avoid potential gcc warning
3789 of coercing an 8 byte integer to a 4 byte pointer. */
3790 (PTRACE_ARG3_TYPE) (uintptr_t) regaddr, 0);
3791 regaddr += sizeof (PTRACE_XFER_TYPE);
3793 error ("reading register %d: %s", regno, strerror (errno));
3796 if (the_low_target.supply_ptrace_register)
3797 the_low_target.supply_ptrace_register (regcache, regno, buf);
3799 supply_register (regcache, regno, buf);
3802 /* Store one register. */
3804 store_register (struct regcache *regcache, int regno)
3811 if (regno >= the_low_target.num_regs)
3813 if ((*the_low_target.cannot_store_register) (regno))
3816 regaddr = register_addr (regno);
3820 size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
3821 & -sizeof (PTRACE_XFER_TYPE));
3822 buf = alloca (size);
3823 memset (buf, 0, size);
3825 if (the_low_target.collect_ptrace_register)
3826 the_low_target.collect_ptrace_register (regcache, regno, buf);
3828 collect_register (regcache, regno, buf);
3830 pid = lwpid_of (get_thread_lwp (current_inferior));
3831 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
3834 ptrace (PTRACE_POKEUSER, pid,
3835 /* Coerce to a uintptr_t first to avoid potential gcc warning
3836 about coercing an 8 byte integer to a 4 byte pointer. */
3837 (PTRACE_ARG3_TYPE) (uintptr_t) regaddr,
3838 (PTRACE_ARG4_TYPE) *(PTRACE_XFER_TYPE *) (buf + i));
3841 /* At this point, ESRCH should mean the process is
3842 already gone, in which case we simply ignore attempts
3843 to change its registers. See also the related
3844 comment in linux_resume_one_lwp. */
3848 if ((*the_low_target.cannot_store_register) (regno) == 0)
3849 error ("writing register %d: %s", regno, strerror (errno));
3851 regaddr += sizeof (PTRACE_XFER_TYPE);
3855 /* Fetch all registers, or just one, from the child process. */
3857 usr_fetch_inferior_registers (struct regcache *regcache, int regno)
3860 for (regno = 0; regno < the_low_target.num_regs; regno++)
3861 fetch_register (regcache, regno);
3863 fetch_register (regcache, regno);
3866 /* Store our register values back into the inferior.
3867 If REGNO is -1, do this for all registers.
3868 Otherwise, REGNO specifies which register (so we can save time). */
3870 usr_store_inferior_registers (struct regcache *regcache, int regno)
3873 for (regno = 0; regno < the_low_target.num_regs; regno++)
3874 store_register (regcache, regno);
3876 store_register (regcache, regno);
3878 #endif /* HAVE_LINUX_USRREGS */
3882 #ifdef HAVE_LINUX_REGSETS
3885 regsets_fetch_inferior_registers (struct regcache *regcache)
3887 struct regset_info *regset;
3888 int saw_general_regs = 0;
3892 regset = target_regsets;
3894 pid = lwpid_of (get_thread_lwp (current_inferior));
3895 while (regset->size >= 0)
3900 if (regset->size == 0 || disabled_regsets[regset - target_regsets])
3906 buf = xmalloc (regset->size);
3908 nt_type = regset->nt_type;
3912 iov.iov_len = regset->size;
3913 data = (void *) &iov;
3919 res = ptrace (regset->get_request, pid, nt_type, data);
3921 res = ptrace (regset->get_request, pid, data, nt_type);
3927 /* If we get EIO on a regset, do not try it again for
3929 disabled_regsets[regset - target_regsets] = 1;
3936 sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d",
3941 else if (regset->type == GENERAL_REGS)
3942 saw_general_regs = 1;
3943 regset->store_function (regcache, buf);
3947 if (saw_general_regs)
3954 regsets_store_inferior_registers (struct regcache *regcache)
3956 struct regset_info *regset;
3957 int saw_general_regs = 0;
3961 regset = target_regsets;
3963 pid = lwpid_of (get_thread_lwp (current_inferior));
3964 while (regset->size >= 0)
3969 if (regset->size == 0 || disabled_regsets[regset - target_regsets])
3975 buf = xmalloc (regset->size);
3977 /* First fill the buffer with the current register set contents,
3978 in case there are any items in the kernel's regset that are
3979 not in gdbserver's regcache. */
3981 nt_type = regset->nt_type;
3985 iov.iov_len = regset->size;
3986 data = (void *) &iov;
3992 res = ptrace (regset->get_request, pid, nt_type, data);
3994 res = ptrace (regset->get_request, pid, &iov, data);
3999 /* Then overlay our cached registers on that. */
4000 regset->fill_function (regcache, buf);
4002 /* Only now do we write the register set. */
4004 res = ptrace (regset->set_request, pid, nt_type, data);
4006 res = ptrace (regset->set_request, pid, data, nt_type);
4014 /* If we get EIO on a regset, do not try it again for
4016 disabled_regsets[regset - target_regsets] = 1;
4020 else if (errno == ESRCH)
4022 /* At this point, ESRCH should mean the process is
4023 already gone, in which case we simply ignore attempts
4024 to change its registers. See also the related
4025 comment in linux_resume_one_lwp. */
4031 perror ("Warning: ptrace(regsets_store_inferior_registers)");
4034 else if (regset->type == GENERAL_REGS)
4035 saw_general_regs = 1;
4039 if (saw_general_regs)
4046 #endif /* HAVE_LINUX_REGSETS */
4050 linux_fetch_registers (struct regcache *regcache, int regno)
4052 #ifdef HAVE_LINUX_REGSETS
4053 if (regsets_fetch_inferior_registers (regcache) == 0)
4056 #ifdef HAVE_LINUX_USRREGS
4057 usr_fetch_inferior_registers (regcache, regno);
4062 linux_store_registers (struct regcache *regcache, int regno)
4064 #ifdef HAVE_LINUX_REGSETS
4065 if (regsets_store_inferior_registers (regcache) == 0)
4068 #ifdef HAVE_LINUX_USRREGS
4069 usr_store_inferior_registers (regcache, regno);
4074 /* Copy LEN bytes from inferior's memory starting at MEMADDR
4075 to debugger memory starting at MYADDR. */
4078 linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
4081 /* Round starting address down to longword boundary. */
4082 register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
4083 /* Round ending address up; get number of longwords that makes. */
4085 = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
4086 / sizeof (PTRACE_XFER_TYPE);
4087 /* Allocate buffer of that many longwords. */
4088 register PTRACE_XFER_TYPE *buffer
4089 = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
4092 int pid = lwpid_of (get_thread_lwp (current_inferior));
4094 /* Try using /proc. Don't bother for one word. */
4095 if (len >= 3 * sizeof (long))
4097 /* We could keep this file open and cache it - possibly one per
4098 thread. That requires some juggling, but is even faster. */
4099 sprintf (filename, "/proc/%d/mem", pid);
4100 fd = open (filename, O_RDONLY | O_LARGEFILE);
4104 /* If pread64 is available, use it. It's faster if the kernel
4105 supports it (only one syscall), and it's 64-bit safe even on
4106 32-bit platforms (for instance, SPARC debugging a SPARC64
4109 if (pread64 (fd, myaddr, len, memaddr) != len)
4111 if (lseek (fd, memaddr, SEEK_SET) == -1 || read (fd, myaddr, len) != len)
4123 /* Read all the longwords */
4124 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
4127 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
4128 about coercing an 8 byte integer to a 4 byte pointer. */
4129 buffer[i] = ptrace (PTRACE_PEEKTEXT, pid,
4130 (PTRACE_ARG3_TYPE) (uintptr_t) addr, 0);
4135 /* Copy appropriate bytes out of the buffer. */
4137 (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
4143 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
4144 memory at MEMADDR. On failure (cannot write to the inferior)
4145 returns the value of errno. */
4148 linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
4151 /* Round starting address down to longword boundary. */
4152 register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
4153 /* Round ending address up; get number of longwords that makes. */
4155 = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
4156 / sizeof (PTRACE_XFER_TYPE);
4158 /* Allocate buffer of that many longwords. */
4159 register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *)
4160 alloca (count * sizeof (PTRACE_XFER_TYPE));
4162 int pid = lwpid_of (get_thread_lwp (current_inferior));
4166 /* Dump up to four bytes. */
4167 unsigned int val = * (unsigned int *) myaddr;
4173 val = val & 0xffffff;
4174 fprintf (stderr, "Writing %0*x to 0x%08lx\n", 2 * ((len < 4) ? len : 4),
4175 val, (long)memaddr);
4178 /* Fill start and end extra bytes of buffer with existing memory data. */
4181 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
4182 about coercing an 8 byte integer to a 4 byte pointer. */
4183 buffer[0] = ptrace (PTRACE_PEEKTEXT, pid,
4184 (PTRACE_ARG3_TYPE) (uintptr_t) addr, 0);
4192 = ptrace (PTRACE_PEEKTEXT, pid,
4193 /* Coerce to a uintptr_t first to avoid potential gcc warning
4194 about coercing an 8 byte integer to a 4 byte pointer. */
4195 (PTRACE_ARG3_TYPE) (uintptr_t) (addr + (count - 1)
4196 * sizeof (PTRACE_XFER_TYPE)),
4202 /* Copy data to be written over corresponding part of buffer. */
4204 memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
4207 /* Write the entire buffer. */
4209 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
4212 ptrace (PTRACE_POKETEXT, pid,
4213 /* Coerce to a uintptr_t first to avoid potential gcc warning
4214 about coercing an 8 byte integer to a 4 byte pointer. */
4215 (PTRACE_ARG3_TYPE) (uintptr_t) addr,
4216 (PTRACE_ARG4_TYPE) buffer[i]);
4224 /* Non-zero if the kernel supports PTRACE_O_TRACEFORK. */
4225 static int linux_supports_tracefork_flag;
4228 linux_enable_event_reporting (int pid)
4230 if (!linux_supports_tracefork_flag)
4233 ptrace (PTRACE_SETOPTIONS, pid, 0, (PTRACE_ARG4_TYPE) PTRACE_O_TRACECLONE);
4236 /* Helper functions for linux_test_for_tracefork, called via clone (). */
4239 linux_tracefork_grandchild (void *arg)
4244 #define STACK_SIZE 4096
4247 linux_tracefork_child (void *arg)
4249 ptrace (PTRACE_TRACEME, 0, 0, 0);
4250 kill (getpid (), SIGSTOP);
4252 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
4255 linux_tracefork_grandchild (NULL);
4257 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4260 __clone2 (linux_tracefork_grandchild, arg, STACK_SIZE,
4261 CLONE_VM | SIGCHLD, NULL);
4263 clone (linux_tracefork_grandchild, (char *) arg + STACK_SIZE,
4264 CLONE_VM | SIGCHLD, NULL);
4267 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4272 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
4273 sure that we can enable the option, and that it had the desired
4277 linux_test_for_tracefork (void)
4279 int child_pid, ret, status;
4281 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4282 char *stack = xmalloc (STACK_SIZE * 4);
4283 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4285 linux_supports_tracefork_flag = 0;
4287 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
4289 child_pid = fork ();
4291 linux_tracefork_child (NULL);
4293 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4295 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
4297 child_pid = __clone2 (linux_tracefork_child, stack, STACK_SIZE,
4298 CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
4299 #else /* !__ia64__ */
4300 child_pid = clone (linux_tracefork_child, stack + STACK_SIZE,
4301 CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
4302 #endif /* !__ia64__ */
4304 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4306 if (child_pid == -1)
4307 perror_with_name ("clone");
4309 ret = my_waitpid (child_pid, &status, 0);
4311 perror_with_name ("waitpid");
4312 else if (ret != child_pid)
4313 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret);
4314 if (! WIFSTOPPED (status))
4315 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status);
4317 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0,
4318 (PTRACE_ARG4_TYPE) PTRACE_O_TRACEFORK);
4321 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
4324 warning ("linux_test_for_tracefork: failed to kill child");
4328 ret = my_waitpid (child_pid, &status, 0);
4329 if (ret != child_pid)
4330 warning ("linux_test_for_tracefork: failed to wait for killed child");
4331 else if (!WIFSIGNALED (status))
4332 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
4333 "killed child", status);
4338 ret = ptrace (PTRACE_CONT, child_pid, 0, 0);
4340 warning ("linux_test_for_tracefork: failed to resume child");
4342 ret = my_waitpid (child_pid, &status, 0);
4344 if (ret == child_pid && WIFSTOPPED (status)
4345 && status >> 16 == PTRACE_EVENT_FORK)
4348 ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
4349 if (ret == 0 && second_pid != 0)
4353 linux_supports_tracefork_flag = 1;
4354 my_waitpid (second_pid, &second_status, 0);
4355 ret = ptrace (PTRACE_KILL, second_pid, 0, 0);
4357 warning ("linux_test_for_tracefork: failed to kill second child");
4358 my_waitpid (second_pid, &status, 0);
4362 warning ("linux_test_for_tracefork: unexpected result from waitpid "
4363 "(%d, status 0x%x)", ret, status);
4367 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
4369 warning ("linux_test_for_tracefork: failed to kill child");
4370 my_waitpid (child_pid, &status, 0);
4372 while (WIFSTOPPED (status));
4374 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4376 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4381 linux_look_up_symbols (void)
4383 #ifdef USE_THREAD_DB
4384 struct process_info *proc = current_process ();
4386 if (proc->private->thread_db != NULL)
4389 /* If the kernel supports tracing forks then it also supports tracing
4390 clones, and then we don't need to use the magic thread event breakpoint
4391 to learn about threads. */
4392 thread_db_init (!linux_supports_tracefork_flag);
4397 linux_request_interrupt (void)
4399 extern unsigned long signal_pid;
4401 if (!ptid_equal (cont_thread, null_ptid)
4402 && !ptid_equal (cont_thread, minus_one_ptid))
4404 struct lwp_info *lwp;
4407 lwp = get_thread_lwp (current_inferior);
4408 lwpid = lwpid_of (lwp);
4409 kill_lwp (lwpid, SIGINT);
4412 kill_lwp (signal_pid, SIGINT);
4415 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
4416 to debugger memory starting at MYADDR. */
4419 linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len)
4421 char filename[PATH_MAX];
4423 int pid = lwpid_of (get_thread_lwp (current_inferior));
4425 xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
4427 fd = open (filename, O_RDONLY);
4431 if (offset != (CORE_ADDR) 0
4432 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
4435 n = read (fd, myaddr, len);
4442 /* These breakpoint and watchpoint related wrapper functions simply
4443 pass on the function call if the target has registered a
4444 corresponding function. */
4447 linux_insert_point (char type, CORE_ADDR addr, int len)
4449 if (the_low_target.insert_point != NULL)
4450 return the_low_target.insert_point (type, addr, len);
4452 /* Unsupported (see target.h). */
4457 linux_remove_point (char type, CORE_ADDR addr, int len)
4459 if (the_low_target.remove_point != NULL)
4460 return the_low_target.remove_point (type, addr, len);
4462 /* Unsupported (see target.h). */
4467 linux_stopped_by_watchpoint (void)
4469 struct lwp_info *lwp = get_thread_lwp (current_inferior);
4471 return lwp->stopped_by_watchpoint;
4475 linux_stopped_data_address (void)
4477 struct lwp_info *lwp = get_thread_lwp (current_inferior);
4479 return lwp->stopped_data_address;
4482 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4483 #if defined(__mcoldfire__)
4484 /* These should really be defined in the kernel's ptrace.h header. */
4485 #define PT_TEXT_ADDR 49*4
4486 #define PT_DATA_ADDR 50*4
4487 #define PT_TEXT_END_ADDR 51*4
4489 #define PT_TEXT_ADDR 220
4490 #define PT_TEXT_END_ADDR 224
4491 #define PT_DATA_ADDR 228
4492 #elif defined(__TMS320C6X__)
4493 #define PT_TEXT_ADDR (0x10000*4)
4494 #define PT_DATA_ADDR (0x10004*4)
4495 #define PT_TEXT_END_ADDR (0x10008*4)
4498 /* Under uClinux, programs are loaded at non-zero offsets, which we need
4499 to tell gdb about. */
4502 linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p)
4504 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
4505 unsigned long text, text_end, data;
4506 int pid = lwpid_of (get_thread_lwp (current_inferior));
4510 text = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_ADDR, 0);
4511 text_end = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_END_ADDR, 0);
4512 data = ptrace (PTRACE_PEEKUSER, pid, (long)PT_DATA_ADDR, 0);
4516 /* Both text and data offsets produced at compile-time (and so
4517 used by gdb) are relative to the beginning of the program,
4518 with the data segment immediately following the text segment.
4519 However, the actual runtime layout in memory may put the data
4520 somewhere else, so when we send gdb a data base-address, we
4521 use the real data base address and subtract the compile-time
4522 data base-address from it (which is just the length of the
4523 text segment). BSS immediately follows data in both
4526 *data_p = data - (text_end - text);
4536 linux_qxfer_osdata (const char *annex,
4537 unsigned char *readbuf, unsigned const char *writebuf,
4538 CORE_ADDR offset, int len)
4540 return linux_common_xfer_osdata (annex, readbuf, offset, len);
4543 /* Convert a native/host siginfo object, into/from the siginfo in the
4544 layout of the inferiors' architecture. */
4547 siginfo_fixup (struct siginfo *siginfo, void *inf_siginfo, int direction)
4551 if (the_low_target.siginfo_fixup != NULL)
4552 done = the_low_target.siginfo_fixup (siginfo, inf_siginfo, direction);
4554 /* If there was no callback, or the callback didn't do anything,
4555 then just do a straight memcpy. */
4559 memcpy (siginfo, inf_siginfo, sizeof (struct siginfo));
4561 memcpy (inf_siginfo, siginfo, sizeof (struct siginfo));
4566 linux_xfer_siginfo (const char *annex, unsigned char *readbuf,
4567 unsigned const char *writebuf, CORE_ADDR offset, int len)
4570 struct siginfo siginfo;
4571 char inf_siginfo[sizeof (struct siginfo)];
4573 if (current_inferior == NULL)
4576 pid = lwpid_of (get_thread_lwp (current_inferior));
4579 fprintf (stderr, "%s siginfo for lwp %d.\n",
4580 readbuf != NULL ? "Reading" : "Writing",
4583 if (offset >= sizeof (siginfo))
4586 if (ptrace (PTRACE_GETSIGINFO, pid, 0, &siginfo) != 0)
4589 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
4590 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
4591 inferior with a 64-bit GDBSERVER should look the same as debugging it
4592 with a 32-bit GDBSERVER, we need to convert it. */
4593 siginfo_fixup (&siginfo, inf_siginfo, 0);
4595 if (offset + len > sizeof (siginfo))
4596 len = sizeof (siginfo) - offset;
4598 if (readbuf != NULL)
4599 memcpy (readbuf, inf_siginfo + offset, len);
4602 memcpy (inf_siginfo + offset, writebuf, len);
4604 /* Convert back to ptrace layout before flushing it out. */
4605 siginfo_fixup (&siginfo, inf_siginfo, 1);
4607 if (ptrace (PTRACE_SETSIGINFO, pid, 0, &siginfo) != 0)
4614 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4615 so we notice when children change state; as the handler for the
4616 sigsuspend in my_waitpid. */
4619 sigchld_handler (int signo)
4621 int old_errno = errno;
4627 /* fprintf is not async-signal-safe, so call write
4629 if (write (2, "sigchld_handler\n",
4630 sizeof ("sigchld_handler\n") - 1) < 0)
4631 break; /* just ignore */
4635 if (target_is_async_p ())
4636 async_file_mark (); /* trigger a linux_wait */
4642 linux_supports_non_stop (void)
4648 linux_async (int enable)
4650 int previous = (linux_event_pipe[0] != -1);
4653 fprintf (stderr, "linux_async (%d), previous=%d\n",
4656 if (previous != enable)
4659 sigemptyset (&mask);
4660 sigaddset (&mask, SIGCHLD);
4662 sigprocmask (SIG_BLOCK, &mask, NULL);
4666 if (pipe (linux_event_pipe) == -1)
4667 fatal ("creating event pipe failed.");
4669 fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK);
4670 fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK);
4672 /* Register the event loop handler. */
4673 add_file_handler (linux_event_pipe[0],
4674 handle_target_event, NULL);
4676 /* Always trigger a linux_wait. */
4681 delete_file_handler (linux_event_pipe[0]);
4683 close (linux_event_pipe[0]);
4684 close (linux_event_pipe[1]);
4685 linux_event_pipe[0] = -1;
4686 linux_event_pipe[1] = -1;
4689 sigprocmask (SIG_UNBLOCK, &mask, NULL);
4696 linux_start_non_stop (int nonstop)
4698 /* Register or unregister from event-loop accordingly. */
4699 linux_async (nonstop);
4704 linux_supports_multi_process (void)
4710 linux_supports_disable_randomization (void)
4712 #ifdef HAVE_PERSONALITY
4719 /* Enumerate spufs IDs for process PID. */
4721 spu_enumerate_spu_ids (long pid, unsigned char *buf, CORE_ADDR offset, int len)
4727 struct dirent *entry;
4729 sprintf (path, "/proc/%ld/fd", pid);
4730 dir = opendir (path);
4735 while ((entry = readdir (dir)) != NULL)
4741 fd = atoi (entry->d_name);
4745 sprintf (path, "/proc/%ld/fd/%d", pid, fd);
4746 if (stat (path, &st) != 0)
4748 if (!S_ISDIR (st.st_mode))
4751 if (statfs (path, &stfs) != 0)
4753 if (stfs.f_type != SPUFS_MAGIC)
4756 if (pos >= offset && pos + 4 <= offset + len)
4758 *(unsigned int *)(buf + pos - offset) = fd;
4768 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
4769 object type, using the /proc file system. */
4771 linux_qxfer_spu (const char *annex, unsigned char *readbuf,
4772 unsigned const char *writebuf,
4773 CORE_ADDR offset, int len)
4775 long pid = lwpid_of (get_thread_lwp (current_inferior));
4780 if (!writebuf && !readbuf)
4788 return spu_enumerate_spu_ids (pid, readbuf, offset, len);
4791 sprintf (buf, "/proc/%ld/fd/%s", pid, annex);
4792 fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
4797 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
4804 ret = write (fd, writebuf, (size_t) len);
4806 ret = read (fd, readbuf, (size_t) len);
4812 #if defined PT_GETDSBT || defined PTRACE_GETFDPIC
4813 struct target_loadseg
4815 /* Core address to which the segment is mapped. */
4817 /* VMA recorded in the program header. */
4819 /* Size of this segment in memory. */
4823 # if defined PT_GETDSBT
4824 struct target_loadmap
4826 /* Protocol version number, must be zero. */
4828 /* Pointer to the DSBT table, its size, and the DSBT index. */
4829 unsigned *dsbt_table;
4830 unsigned dsbt_size, dsbt_index;
4831 /* Number of segments in this map. */
4833 /* The actual memory map. */
4834 struct target_loadseg segs[/*nsegs*/];
4836 # define LINUX_LOADMAP PT_GETDSBT
4837 # define LINUX_LOADMAP_EXEC PTRACE_GETDSBT_EXEC
4838 # define LINUX_LOADMAP_INTERP PTRACE_GETDSBT_INTERP
4840 struct target_loadmap
4842 /* Protocol version number, must be zero. */
4844 /* Number of segments in this map. */
4846 /* The actual memory map. */
4847 struct target_loadseg segs[/*nsegs*/];
4849 # define LINUX_LOADMAP PTRACE_GETFDPIC
4850 # define LINUX_LOADMAP_EXEC PTRACE_GETFDPIC_EXEC
4851 # define LINUX_LOADMAP_INTERP PTRACE_GETFDPIC_INTERP
4855 linux_read_loadmap (const char *annex, CORE_ADDR offset,
4856 unsigned char *myaddr, unsigned int len)
4858 int pid = lwpid_of (get_thread_lwp (current_inferior));
4860 struct target_loadmap *data = NULL;
4861 unsigned int actual_length, copy_length;
4863 if (strcmp (annex, "exec") == 0)
4864 addr = (int) LINUX_LOADMAP_EXEC;
4865 else if (strcmp (annex, "interp") == 0)
4866 addr = (int) LINUX_LOADMAP_INTERP;
4870 if (ptrace (LINUX_LOADMAP, pid, addr, &data) != 0)
4876 actual_length = sizeof (struct target_loadmap)
4877 + sizeof (struct target_loadseg) * data->nsegs;
4879 if (offset < 0 || offset > actual_length)
4882 copy_length = actual_length - offset < len ? actual_length - offset : len;
4883 memcpy (myaddr, (char *) data + offset, copy_length);
4887 # define linux_read_loadmap NULL
4888 #endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */
4891 linux_process_qsupported (const char *query)
4893 if (the_low_target.process_qsupported != NULL)
4894 the_low_target.process_qsupported (query);
4898 linux_supports_tracepoints (void)
4900 if (*the_low_target.supports_tracepoints == NULL)
4903 return (*the_low_target.supports_tracepoints) ();
4907 linux_read_pc (struct regcache *regcache)
4909 if (the_low_target.get_pc == NULL)
4912 return (*the_low_target.get_pc) (regcache);
4916 linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
4918 gdb_assert (the_low_target.set_pc != NULL);
4920 (*the_low_target.set_pc) (regcache, pc);
4924 linux_thread_stopped (struct thread_info *thread)
4926 return get_thread_lwp (thread)->stopped;
4929 /* This exposes stop-all-threads functionality to other modules. */
4932 linux_pause_all (int freeze)
4934 stop_all_lwps (freeze, NULL);
4937 /* This exposes unstop-all-threads functionality to other gdbserver
4941 linux_unpause_all (int unfreeze)
4943 unstop_all_lwps (unfreeze, NULL);
4947 linux_prepare_to_access_memory (void)
4949 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
4952 linux_pause_all (1);
4957 linux_done_accessing_memory (void)
4959 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
4962 linux_unpause_all (1);
4966 linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr,
4967 CORE_ADDR collector,
4970 CORE_ADDR *jump_entry,
4971 CORE_ADDR *trampoline,
4972 ULONGEST *trampoline_size,
4973 unsigned char *jjump_pad_insn,
4974 ULONGEST *jjump_pad_insn_size,
4975 CORE_ADDR *adjusted_insn_addr,
4976 CORE_ADDR *adjusted_insn_addr_end,
4979 return (*the_low_target.install_fast_tracepoint_jump_pad)
4980 (tpoint, tpaddr, collector, lockaddr, orig_size,
4981 jump_entry, trampoline, trampoline_size,
4982 jjump_pad_insn, jjump_pad_insn_size,
4983 adjusted_insn_addr, adjusted_insn_addr_end,
4987 static struct emit_ops *
4988 linux_emit_ops (void)
4990 if (the_low_target.emit_ops != NULL)
4991 return (*the_low_target.emit_ops) ();
4997 linux_get_min_fast_tracepoint_insn_len (void)
4999 return (*the_low_target.get_min_fast_tracepoint_insn_len) ();
5002 /* Extract &phdr and num_phdr in the inferior. Return 0 on success. */
5005 get_phdr_phnum_from_proc_auxv (const int pid, const int is_elf64,
5006 CORE_ADDR *phdr_memaddr, int *num_phdr)
5008 char filename[PATH_MAX];
5010 const int auxv_size = is_elf64
5011 ? sizeof (Elf64_auxv_t) : sizeof (Elf32_auxv_t);
5012 char buf[sizeof (Elf64_auxv_t)]; /* The larger of the two. */
5014 xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
5016 fd = open (filename, O_RDONLY);
5022 while (read (fd, buf, auxv_size) == auxv_size
5023 && (*phdr_memaddr == 0 || *num_phdr == 0))
5027 Elf64_auxv_t *const aux = (Elf64_auxv_t *) buf;
5029 switch (aux->a_type)
5032 *phdr_memaddr = aux->a_un.a_val;
5035 *num_phdr = aux->a_un.a_val;
5041 Elf32_auxv_t *const aux = (Elf32_auxv_t *) buf;
5043 switch (aux->a_type)
5046 *phdr_memaddr = aux->a_un.a_val;
5049 *num_phdr = aux->a_un.a_val;
5057 if (*phdr_memaddr == 0 || *num_phdr == 0)
5059 warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: "
5060 "phdr_memaddr = %ld, phdr_num = %d",
5061 (long) *phdr_memaddr, *num_phdr);
5068 /* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */
5071 get_dynamic (const int pid, const int is_elf64)
5073 CORE_ADDR phdr_memaddr, relocation;
5075 unsigned char *phdr_buf;
5076 const int phdr_size = is_elf64 ? sizeof (Elf64_Phdr) : sizeof (Elf32_Phdr);
5078 if (get_phdr_phnum_from_proc_auxv (pid, is_elf64, &phdr_memaddr, &num_phdr))
5081 gdb_assert (num_phdr < 100); /* Basic sanity check. */
5082 phdr_buf = alloca (num_phdr * phdr_size);
5084 if (linux_read_memory (phdr_memaddr, phdr_buf, num_phdr * phdr_size))
5087 /* Compute relocation: it is expected to be 0 for "regular" executables,
5088 non-zero for PIE ones. */
5090 for (i = 0; relocation == -1 && i < num_phdr; i++)
5093 Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size);
5095 if (p->p_type == PT_PHDR)
5096 relocation = phdr_memaddr - p->p_vaddr;
5100 Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size);
5102 if (p->p_type == PT_PHDR)
5103 relocation = phdr_memaddr - p->p_vaddr;
5106 if (relocation == -1)
5108 warning ("Unexpected missing PT_PHDR");
5112 for (i = 0; i < num_phdr; i++)
5116 Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size);
5118 if (p->p_type == PT_DYNAMIC)
5119 return p->p_vaddr + relocation;
5123 Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size);
5125 if (p->p_type == PT_DYNAMIC)
5126 return p->p_vaddr + relocation;
5133 /* Return &_r_debug in the inferior, or -1 if not present. Return value
5134 can be 0 if the inferior does not yet have the library list initialized. */
5137 get_r_debug (const int pid, const int is_elf64)
5139 CORE_ADDR dynamic_memaddr;
5140 const int dyn_size = is_elf64 ? sizeof (Elf64_Dyn) : sizeof (Elf32_Dyn);
5141 unsigned char buf[sizeof (Elf64_Dyn)]; /* The larger of the two. */
5143 dynamic_memaddr = get_dynamic (pid, is_elf64);
5144 if (dynamic_memaddr == 0)
5145 return (CORE_ADDR) -1;
5147 while (linux_read_memory (dynamic_memaddr, buf, dyn_size) == 0)
5151 Elf64_Dyn *const dyn = (Elf64_Dyn *) buf;
5153 if (dyn->d_tag == DT_DEBUG)
5154 return dyn->d_un.d_val;
5156 if (dyn->d_tag == DT_NULL)
5161 Elf32_Dyn *const dyn = (Elf32_Dyn *) buf;
5163 if (dyn->d_tag == DT_DEBUG)
5164 return dyn->d_un.d_val;
5166 if (dyn->d_tag == DT_NULL)
5170 dynamic_memaddr += dyn_size;
5173 return (CORE_ADDR) -1;
5176 /* Read one pointer from MEMADDR in the inferior. */
5179 read_one_ptr (CORE_ADDR memaddr, CORE_ADDR *ptr, int ptr_size)
5182 return linux_read_memory (memaddr, (unsigned char *) ptr, ptr_size);
5185 struct link_map_offsets
5187 /* Offset and size of r_debug.r_version. */
5188 int r_version_offset;
5190 /* Offset and size of r_debug.r_map. */
5193 /* Offset to l_addr field in struct link_map. */
5196 /* Offset to l_name field in struct link_map. */
5199 /* Offset to l_ld field in struct link_map. */
5202 /* Offset to l_next field in struct link_map. */
5205 /* Offset to l_prev field in struct link_map. */
5209 /* Construct qXfer:libraries:read reply. */
5212 linux_qxfer_libraries_svr4 (const char *annex, unsigned char *readbuf,
5213 unsigned const char *writebuf,
5214 CORE_ADDR offset, int len)
5217 unsigned document_len;
5218 struct process_info_private *const priv = current_process ()->private;
5219 char filename[PATH_MAX];
5222 static const struct link_map_offsets lmo_32bit_offsets =
5224 0, /* r_version offset. */
5225 4, /* r_debug.r_map offset. */
5226 0, /* l_addr offset in link_map. */
5227 4, /* l_name offset in link_map. */
5228 8, /* l_ld offset in link_map. */
5229 12, /* l_next offset in link_map. */
5230 16 /* l_prev offset in link_map. */
5233 static const struct link_map_offsets lmo_64bit_offsets =
5235 0, /* r_version offset. */
5236 8, /* r_debug.r_map offset. */
5237 0, /* l_addr offset in link_map. */
5238 8, /* l_name offset in link_map. */
5239 16, /* l_ld offset in link_map. */
5240 24, /* l_next offset in link_map. */
5241 32 /* l_prev offset in link_map. */
5243 const struct link_map_offsets *lmo;
5245 if (writebuf != NULL)
5247 if (readbuf == NULL)
5250 pid = lwpid_of (get_thread_lwp (current_inferior));
5251 xsnprintf (filename, sizeof filename, "/proc/%d/exe", pid);
5252 is_elf64 = elf_64_file_p (filename);
5253 lmo = is_elf64 ? &lmo_64bit_offsets : &lmo_32bit_offsets;
5255 if (priv->r_debug == 0)
5256 priv->r_debug = get_r_debug (pid, is_elf64);
5258 if (priv->r_debug == (CORE_ADDR) -1 || priv->r_debug == 0)
5260 document = xstrdup ("<library-list-svr4 version=\"1.0\"/>\n");
5264 int allocated = 1024;
5266 const int ptr_size = is_elf64 ? 8 : 4;
5267 CORE_ADDR lm_addr, lm_prev, l_name, l_addr, l_ld, l_next, l_prev;
5268 int r_version, header_done = 0;
5270 document = xmalloc (allocated);
5271 strcpy (document, "<library-list-svr4 version=\"1.0\"");
5272 p = document + strlen (document);
5275 if (linux_read_memory (priv->r_debug + lmo->r_version_offset,
5276 (unsigned char *) &r_version,
5277 sizeof (r_version)) != 0
5280 warning ("unexpected r_debug version %d", r_version);
5284 if (read_one_ptr (priv->r_debug + lmo->r_map_offset,
5285 &lm_addr, ptr_size) != 0)
5287 warning ("unable to read r_map from 0x%lx",
5288 (long) priv->r_debug + lmo->r_map_offset);
5293 while (read_one_ptr (lm_addr + lmo->l_name_offset,
5294 &l_name, ptr_size) == 0
5295 && read_one_ptr (lm_addr + lmo->l_addr_offset,
5296 &l_addr, ptr_size) == 0
5297 && read_one_ptr (lm_addr + lmo->l_ld_offset,
5298 &l_ld, ptr_size) == 0
5299 && read_one_ptr (lm_addr + lmo->l_prev_offset,
5300 &l_prev, ptr_size) == 0
5301 && read_one_ptr (lm_addr + lmo->l_next_offset,
5302 &l_next, ptr_size) == 0)
5304 unsigned char libname[PATH_MAX];
5306 if (lm_prev != l_prev)
5308 warning ("Corrupted shared library list: 0x%lx != 0x%lx",
5309 (long) lm_prev, (long) l_prev);
5313 /* Not checking for error because reading may stop before
5314 we've got PATH_MAX worth of characters. */
5316 linux_read_memory (l_name, libname, sizeof (libname) - 1);
5317 libname[sizeof (libname) - 1] = '\0';
5318 if (libname[0] != '\0')
5320 /* 6x the size for xml_escape_text below. */
5321 size_t len = 6 * strlen ((char *) libname);
5326 /* Terminate `<library-list-svr4'. */
5331 while (allocated < p - document + len + 200)
5333 /* Expand to guarantee sufficient storage. */
5334 uintptr_t document_len = p - document;
5336 document = xrealloc (document, 2 * allocated);
5338 p = document + document_len;
5341 name = xml_escape_text ((char *) libname);
5342 p += sprintf (p, "<library name=\"%s\" lm=\"0x%lx\" "
5343 "l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>",
5344 name, (unsigned long) lm_addr,
5345 (unsigned long) l_addr, (unsigned long) l_ld);
5348 else if (lm_prev == 0)
5350 sprintf (p, " main-lm=\"0x%lx\"", (unsigned long) lm_addr);
5361 strcpy (p, "</library-list-svr4>");
5364 document_len = strlen (document);
5365 if (offset < document_len)
5366 document_len -= offset;
5369 if (len > document_len)
5372 memcpy (readbuf, document + offset, len);
5378 static struct target_ops linux_target_ops = {
5379 linux_create_inferior,
5388 linux_fetch_registers,
5389 linux_store_registers,
5390 linux_prepare_to_access_memory,
5391 linux_done_accessing_memory,
5394 linux_look_up_symbols,
5395 linux_request_interrupt,
5399 linux_stopped_by_watchpoint,
5400 linux_stopped_data_address,
5401 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
5406 #ifdef USE_THREAD_DB
5407 thread_db_get_tls_address,
5412 hostio_last_error_from_errno,
5415 linux_supports_non_stop,
5417 linux_start_non_stop,
5418 linux_supports_multi_process,
5419 #ifdef USE_THREAD_DB
5420 thread_db_handle_monitor_command,
5424 linux_common_core_of_thread,
5426 linux_process_qsupported,
5427 linux_supports_tracepoints,
5430 linux_thread_stopped,
5434 linux_cancel_breakpoints,
5435 linux_stabilize_threads,
5436 linux_install_fast_tracepoint_jump_pad,
5438 linux_supports_disable_randomization,
5439 linux_get_min_fast_tracepoint_insn_len,
5440 linux_qxfer_libraries_svr4,
5444 linux_init_signals ()
5446 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
5447 to find what the cancel signal actually is. */
5448 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
5449 signal (__SIGRTMIN+1, SIG_IGN);
5454 initialize_low (void)
5456 struct sigaction sigchld_action;
5457 memset (&sigchld_action, 0, sizeof (sigchld_action));
5458 set_target_ops (&linux_target_ops);
5459 set_breakpoint_data (the_low_target.breakpoint,
5460 the_low_target.breakpoint_len);
5461 linux_init_signals ();
5462 linux_test_for_tracefork ();
5463 #ifdef HAVE_LINUX_REGSETS
5464 for (num_regsets = 0; target_regsets[num_regsets].size >= 0; num_regsets++)
5466 disabled_regsets = xmalloc (num_regsets);
5469 sigchld_action.sa_handler = sigchld_handler;
5470 sigemptyset (&sigchld_action.sa_mask);
5471 sigchld_action.sa_flags = SA_RESTART;
5472 sigaction (SIGCHLD, &sigchld_action, NULL);