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)
2402 && gdb_condition_true_at_breakpoint (event_child->stop_pc)));
2404 /* We found no reason GDB would want us to stop. We either hit one
2405 of our own breakpoints, or finished an internal step GDB
2406 shouldn't know about. */
2411 if (bp_explains_trap)
2412 fprintf (stderr, "Hit a gdbserver breakpoint.\n");
2413 if (step_over_finished)
2414 fprintf (stderr, "Step-over finished.\n");
2416 fprintf (stderr, "Tracepoint event.\n");
2419 /* We're not reporting this breakpoint to GDB, so apply the
2420 decr_pc_after_break adjustment to the inferior's regcache
2423 if (the_low_target.set_pc != NULL)
2425 struct regcache *regcache
2426 = get_thread_regcache (get_lwp_thread (event_child), 1);
2427 (*the_low_target.set_pc) (regcache, event_child->stop_pc);
2430 /* We may have finished stepping over a breakpoint. If so,
2431 we've stopped and suspended all LWPs momentarily except the
2432 stepping one. This is where we resume them all again. We're
2433 going to keep waiting, so use proceed, which handles stepping
2434 over the next breakpoint. */
2436 fprintf (stderr, "proceeding all threads.\n");
2438 if (step_over_finished)
2439 unsuspend_all_lwps (event_child);
2441 proceed_all_lwps ();
2447 if (current_inferior->last_resume_kind == resume_step)
2448 fprintf (stderr, "GDB wanted to single-step, reporting event.\n");
2449 if (event_child->stopped_by_watchpoint)
2450 fprintf (stderr, "Stopped by watchpoint.\n");
2451 if (gdb_breakpoint_here (event_child->stop_pc))
2452 fprintf (stderr, "Stopped by GDB breakpoint.\n");
2454 fprintf (stderr, "Hit a non-gdbserver trap event.\n");
2457 /* Alright, we're going to report a stop. */
2459 if (!non_stop && !stabilizing_threads)
2461 /* In all-stop, stop all threads. */
2462 stop_all_lwps (0, NULL);
2464 /* If we're not waiting for a specific LWP, choose an event LWP
2465 from among those that have had events. Giving equal priority
2466 to all LWPs that have had events helps prevent
2468 if (ptid_equal (ptid, minus_one_ptid))
2470 event_child->status_pending_p = 1;
2471 event_child->status_pending = w;
2473 select_event_lwp (&event_child);
2475 event_child->status_pending_p = 0;
2476 w = event_child->status_pending;
2479 /* Now that we've selected our final event LWP, cancel any
2480 breakpoints in other LWPs that have hit a GDB breakpoint.
2481 See the comment in cancel_breakpoints_callback to find out
2483 find_inferior (&all_lwps, cancel_breakpoints_callback, event_child);
2485 /* Stabilize threads (move out of jump pads). */
2486 stabilize_threads ();
2490 /* If we just finished a step-over, then all threads had been
2491 momentarily paused. In all-stop, that's fine, we want
2492 threads stopped by now anyway. In non-stop, we need to
2493 re-resume threads that GDB wanted to be running. */
2494 if (step_over_finished)
2495 unstop_all_lwps (1, event_child);
2498 ourstatus->kind = TARGET_WAITKIND_STOPPED;
2500 if (current_inferior->last_resume_kind == resume_stop
2501 && WSTOPSIG (w) == SIGSTOP)
2503 /* A thread that has been requested to stop by GDB with vCont;t,
2504 and it stopped cleanly, so report as SIG0. The use of
2505 SIGSTOP is an implementation detail. */
2506 ourstatus->value.sig = TARGET_SIGNAL_0;
2508 else if (current_inferior->last_resume_kind == resume_stop
2509 && WSTOPSIG (w) != SIGSTOP)
2511 /* A thread that has been requested to stop by GDB with vCont;t,
2512 but, it stopped for other reasons. */
2513 ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
2517 ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
2520 gdb_assert (ptid_equal (step_over_bkpt, null_ptid));
2523 fprintf (stderr, "linux_wait ret = %s, %d, %d\n",
2524 target_pid_to_str (ptid_of (event_child)),
2526 ourstatus->value.sig);
2528 return ptid_of (event_child);
2531 /* Get rid of any pending event in the pipe. */
2533 async_file_flush (void)
2539 ret = read (linux_event_pipe[0], &buf, 1);
2540 while (ret >= 0 || (ret == -1 && errno == EINTR));
2543 /* Put something in the pipe, so the event loop wakes up. */
2545 async_file_mark (void)
2549 async_file_flush ();
2552 ret = write (linux_event_pipe[1], "+", 1);
2553 while (ret == 0 || (ret == -1 && errno == EINTR));
2555 /* Ignore EAGAIN. If the pipe is full, the event loop will already
2556 be awakened anyway. */
2560 linux_wait (ptid_t ptid,
2561 struct target_waitstatus *ourstatus, int target_options)
2566 fprintf (stderr, "linux_wait: [%s]\n", target_pid_to_str (ptid));
2568 /* Flush the async file first. */
2569 if (target_is_async_p ())
2570 async_file_flush ();
2572 event_ptid = linux_wait_1 (ptid, ourstatus, target_options);
2574 /* If at least one stop was reported, there may be more. A single
2575 SIGCHLD can signal more than one child stop. */
2576 if (target_is_async_p ()
2577 && (target_options & TARGET_WNOHANG) != 0
2578 && !ptid_equal (event_ptid, null_ptid))
2584 /* Send a signal to an LWP. */
2587 kill_lwp (unsigned long lwpid, int signo)
2589 /* Use tkill, if possible, in case we are using nptl threads. If tkill
2590 fails, then we are not using nptl threads and we should be using kill. */
2594 static int tkill_failed;
2601 ret = syscall (__NR_tkill, lwpid, signo);
2602 if (errno != ENOSYS)
2609 return kill (lwpid, signo);
2613 linux_stop_lwp (struct lwp_info *lwp)
2619 send_sigstop (struct lwp_info *lwp)
2623 pid = lwpid_of (lwp);
2625 /* If we already have a pending stop signal for this process, don't
2627 if (lwp->stop_expected)
2630 fprintf (stderr, "Have pending sigstop for lwp %d\n", pid);
2636 fprintf (stderr, "Sending sigstop to lwp %d\n", pid);
2638 lwp->stop_expected = 1;
2639 kill_lwp (pid, SIGSTOP);
2643 send_sigstop_callback (struct inferior_list_entry *entry, void *except)
2645 struct lwp_info *lwp = (struct lwp_info *) entry;
2647 /* Ignore EXCEPT. */
2658 /* Increment the suspend count of an LWP, and stop it, if not stopped
2661 suspend_and_send_sigstop_callback (struct inferior_list_entry *entry,
2664 struct lwp_info *lwp = (struct lwp_info *) entry;
2666 /* Ignore EXCEPT. */
2672 return send_sigstop_callback (entry, except);
2676 mark_lwp_dead (struct lwp_info *lwp, int wstat)
2678 /* It's dead, really. */
2681 /* Store the exit status for later. */
2682 lwp->status_pending_p = 1;
2683 lwp->status_pending = wstat;
2685 /* Prevent trying to stop it. */
2688 /* No further stops are expected from a dead lwp. */
2689 lwp->stop_expected = 0;
2693 wait_for_sigstop (struct inferior_list_entry *entry)
2695 struct lwp_info *lwp = (struct lwp_info *) entry;
2696 struct thread_info *saved_inferior;
2705 fprintf (stderr, "wait_for_sigstop: LWP %ld already stopped\n",
2710 saved_inferior = current_inferior;
2711 if (saved_inferior != NULL)
2712 saved_tid = ((struct inferior_list_entry *) saved_inferior)->id;
2714 saved_tid = null_ptid; /* avoid bogus unused warning */
2716 ptid = lwp->head.id;
2719 fprintf (stderr, "wait_for_sigstop: pulling one event\n");
2721 pid = linux_wait_for_event (ptid, &wstat, __WALL);
2723 /* If we stopped with a non-SIGSTOP signal, save it for later
2724 and record the pending SIGSTOP. If the process exited, just
2726 if (WIFSTOPPED (wstat))
2729 fprintf (stderr, "LWP %ld stopped with signal %d\n",
2730 lwpid_of (lwp), WSTOPSIG (wstat));
2732 if (WSTOPSIG (wstat) != SIGSTOP)
2735 fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n",
2736 lwpid_of (lwp), wstat);
2738 lwp->status_pending_p = 1;
2739 lwp->status_pending = wstat;
2745 fprintf (stderr, "Process %d exited while stopping LWPs\n", pid);
2747 lwp = find_lwp_pid (pid_to_ptid (pid));
2750 /* Leave this status pending for the next time we're able to
2751 report it. In the mean time, we'll report this lwp as
2752 dead to GDB, so GDB doesn't try to read registers and
2753 memory from it. This can only happen if this was the
2754 last thread of the process; otherwise, PID is removed
2755 from the thread tables before linux_wait_for_event
2757 mark_lwp_dead (lwp, wstat);
2761 if (saved_inferior == NULL || linux_thread_alive (saved_tid))
2762 current_inferior = saved_inferior;
2766 fprintf (stderr, "Previously current thread died.\n");
2770 /* We can't change the current inferior behind GDB's back,
2771 otherwise, a subsequent command may apply to the wrong
2773 current_inferior = NULL;
2777 /* Set a valid thread as current. */
2778 set_desired_inferior (0);
2783 /* Returns true if LWP ENTRY is stopped in a jump pad, and we can't
2784 move it out, because we need to report the stop event to GDB. For
2785 example, if the user puts a breakpoint in the jump pad, it's
2786 because she wants to debug it. */
2789 stuck_in_jump_pad_callback (struct inferior_list_entry *entry, void *data)
2791 struct lwp_info *lwp = (struct lwp_info *) entry;
2792 struct thread_info *thread = get_lwp_thread (lwp);
2794 gdb_assert (lwp->suspended == 0);
2795 gdb_assert (lwp->stopped);
2797 /* Allow debugging the jump pad, gdb_collect, etc.. */
2798 return (supports_fast_tracepoints ()
2799 && in_process_agent_loaded ()
2800 && (gdb_breakpoint_here (lwp->stop_pc)
2801 || lwp->stopped_by_watchpoint
2802 || thread->last_resume_kind == resume_step)
2803 && linux_fast_tracepoint_collecting (lwp, NULL));
2807 move_out_of_jump_pad_callback (struct inferior_list_entry *entry)
2809 struct lwp_info *lwp = (struct lwp_info *) entry;
2810 struct thread_info *thread = get_lwp_thread (lwp);
2813 gdb_assert (lwp->suspended == 0);
2814 gdb_assert (lwp->stopped);
2816 wstat = lwp->status_pending_p ? &lwp->status_pending : NULL;
2818 /* Allow debugging the jump pad, gdb_collect, etc. */
2819 if (!gdb_breakpoint_here (lwp->stop_pc)
2820 && !lwp->stopped_by_watchpoint
2821 && thread->last_resume_kind != resume_step
2822 && maybe_move_out_of_jump_pad (lwp, wstat))
2826 "LWP %ld needs stabilizing (in jump pad)\n",
2831 lwp->status_pending_p = 0;
2832 enqueue_one_deferred_signal (lwp, wstat);
2836 "Signal %d for LWP %ld deferred "
2838 WSTOPSIG (*wstat), lwpid_of (lwp));
2841 linux_resume_one_lwp (lwp, 0, 0, NULL);
2848 lwp_running (struct inferior_list_entry *entry, void *data)
2850 struct lwp_info *lwp = (struct lwp_info *) entry;
2859 /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
2860 If SUSPEND, then also increase the suspend count of every LWP,
2864 stop_all_lwps (int suspend, struct lwp_info *except)
2866 stopping_threads = 1;
2869 find_inferior (&all_lwps, suspend_and_send_sigstop_callback, except);
2871 find_inferior (&all_lwps, send_sigstop_callback, except);
2872 for_each_inferior (&all_lwps, wait_for_sigstop);
2873 stopping_threads = 0;
2876 /* Resume execution of the inferior process.
2877 If STEP is nonzero, single-step it.
2878 If SIGNAL is nonzero, give it that signal. */
2881 linux_resume_one_lwp (struct lwp_info *lwp,
2882 int step, int signal, siginfo_t *info)
2884 struct thread_info *saved_inferior;
2885 int fast_tp_collecting;
2887 if (lwp->stopped == 0)
2890 fast_tp_collecting = lwp->collecting_fast_tracepoint;
2892 gdb_assert (!stabilizing_threads || fast_tp_collecting);
2894 /* Cancel actions that rely on GDB not changing the PC (e.g., the
2895 user used the "jump" command, or "set $pc = foo"). */
2896 if (lwp->stop_pc != get_pc (lwp))
2898 /* Collecting 'while-stepping' actions doesn't make sense
2900 release_while_stepping_state_list (get_lwp_thread (lwp));
2903 /* If we have pending signals or status, and a new signal, enqueue the
2904 signal. Also enqueue the signal if we are waiting to reinsert a
2905 breakpoint; it will be picked up again below. */
2907 && (lwp->status_pending_p
2908 || lwp->pending_signals != NULL
2909 || lwp->bp_reinsert != 0
2910 || fast_tp_collecting))
2912 struct pending_signals *p_sig;
2913 p_sig = xmalloc (sizeof (*p_sig));
2914 p_sig->prev = lwp->pending_signals;
2915 p_sig->signal = signal;
2917 memset (&p_sig->info, 0, sizeof (siginfo_t));
2919 memcpy (&p_sig->info, info, sizeof (siginfo_t));
2920 lwp->pending_signals = p_sig;
2923 if (lwp->status_pending_p)
2926 fprintf (stderr, "Not resuming lwp %ld (%s, signal %d, stop %s);"
2927 " has pending status\n",
2928 lwpid_of (lwp), step ? "step" : "continue", signal,
2929 lwp->stop_expected ? "expected" : "not expected");
2933 saved_inferior = current_inferior;
2934 current_inferior = get_lwp_thread (lwp);
2937 fprintf (stderr, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
2938 lwpid_of (lwp), step ? "step" : "continue", signal,
2939 lwp->stop_expected ? "expected" : "not expected");
2941 /* This bit needs some thinking about. If we get a signal that
2942 we must report while a single-step reinsert is still pending,
2943 we often end up resuming the thread. It might be better to
2944 (ew) allow a stack of pending events; then we could be sure that
2945 the reinsert happened right away and not lose any signals.
2947 Making this stack would also shrink the window in which breakpoints are
2948 uninserted (see comment in linux_wait_for_lwp) but not enough for
2949 complete correctness, so it won't solve that problem. It may be
2950 worthwhile just to solve this one, however. */
2951 if (lwp->bp_reinsert != 0)
2954 fprintf (stderr, " pending reinsert at 0x%s\n",
2955 paddress (lwp->bp_reinsert));
2957 if (lwp->bp_reinsert != 0 && can_hardware_single_step ())
2959 if (fast_tp_collecting == 0)
2962 fprintf (stderr, "BAD - reinserting but not stepping.\n");
2964 fprintf (stderr, "BAD - reinserting and suspended(%d).\n",
2971 /* Postpone any pending signal. It was enqueued above. */
2975 if (fast_tp_collecting == 1)
2979 lwp %ld wants to get out of fast tracepoint jump pad (exit-jump-pad-bkpt)\n",
2982 /* Postpone any pending signal. It was enqueued above. */
2985 else if (fast_tp_collecting == 2)
2989 lwp %ld wants to get out of fast tracepoint jump pad single-stepping\n",
2992 if (can_hardware_single_step ())
2995 fatal ("moving out of jump pad single-stepping"
2996 " not implemented on this target");
2998 /* Postpone any pending signal. It was enqueued above. */
3002 /* If we have while-stepping actions in this thread set it stepping.
3003 If we have a signal to deliver, it may or may not be set to
3004 SIG_IGN, we don't know. Assume so, and allow collecting
3005 while-stepping into a signal handler. A possible smart thing to
3006 do would be to set an internal breakpoint at the signal return
3007 address, continue, and carry on catching this while-stepping
3008 action only when that breakpoint is hit. A future
3010 if (get_lwp_thread (lwp)->while_stepping != NULL
3011 && can_hardware_single_step ())
3015 "lwp %ld has a while-stepping action -> forcing step.\n",
3020 if (debug_threads && the_low_target.get_pc != NULL)
3022 struct regcache *regcache = get_thread_regcache (current_inferior, 1);
3023 CORE_ADDR pc = (*the_low_target.get_pc) (regcache);
3024 fprintf (stderr, " resuming from pc 0x%lx\n", (long) pc);
3027 /* If we have pending signals, consume one unless we are trying to
3028 reinsert a breakpoint or we're trying to finish a fast tracepoint
3030 if (lwp->pending_signals != NULL
3031 && lwp->bp_reinsert == 0
3032 && fast_tp_collecting == 0)
3034 struct pending_signals **p_sig;
3036 p_sig = &lwp->pending_signals;
3037 while ((*p_sig)->prev != NULL)
3038 p_sig = &(*p_sig)->prev;
3040 signal = (*p_sig)->signal;
3041 if ((*p_sig)->info.si_signo != 0)
3042 ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &(*p_sig)->info);
3048 if (the_low_target.prepare_to_resume != NULL)
3049 the_low_target.prepare_to_resume (lwp);
3051 regcache_invalidate_one ((struct inferior_list_entry *)
3052 get_lwp_thread (lwp));
3055 lwp->stopped_by_watchpoint = 0;
3056 lwp->stepping = step;
3057 ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (lwp), 0,
3058 /* Coerce to a uintptr_t first to avoid potential gcc warning
3059 of coercing an 8 byte integer to a 4 byte pointer. */
3060 (PTRACE_ARG4_TYPE) (uintptr_t) signal);
3062 current_inferior = saved_inferior;
3065 /* ESRCH from ptrace either means that the thread was already
3066 running (an error) or that it is gone (a race condition). If
3067 it's gone, we will get a notification the next time we wait,
3068 so we can ignore the error. We could differentiate these
3069 two, but it's tricky without waiting; the thread still exists
3070 as a zombie, so sending it signal 0 would succeed. So just
3075 perror_with_name ("ptrace");
3079 struct thread_resume_array
3081 struct thread_resume *resume;
3085 /* This function is called once per thread. We look up the thread
3086 in RESUME_PTR, and mark the thread with a pointer to the appropriate
3089 This algorithm is O(threads * resume elements), but resume elements
3090 is small (and will remain small at least until GDB supports thread
3093 linux_set_resume_request (struct inferior_list_entry *entry, void *arg)
3095 struct lwp_info *lwp;
3096 struct thread_info *thread;
3098 struct thread_resume_array *r;
3100 thread = (struct thread_info *) entry;
3101 lwp = get_thread_lwp (thread);
3104 for (ndx = 0; ndx < r->n; ndx++)
3106 ptid_t ptid = r->resume[ndx].thread;
3107 if (ptid_equal (ptid, minus_one_ptid)
3108 || ptid_equal (ptid, entry->id)
3109 || (ptid_is_pid (ptid)
3110 && (ptid_get_pid (ptid) == pid_of (lwp)))
3111 || (ptid_get_lwp (ptid) == -1
3112 && (ptid_get_pid (ptid) == pid_of (lwp))))
3114 if (r->resume[ndx].kind == resume_stop
3115 && thread->last_resume_kind == resume_stop)
3118 fprintf (stderr, "already %s LWP %ld at GDB's request\n",
3119 thread->last_status.kind == TARGET_WAITKIND_STOPPED
3127 lwp->resume = &r->resume[ndx];
3128 thread->last_resume_kind = lwp->resume->kind;
3130 /* If we had a deferred signal to report, dequeue one now.
3131 This can happen if LWP gets more than one signal while
3132 trying to get out of a jump pad. */
3134 && !lwp->status_pending_p
3135 && dequeue_one_deferred_signal (lwp, &lwp->status_pending))
3137 lwp->status_pending_p = 1;
3141 "Dequeueing deferred signal %d for LWP %ld, "
3142 "leaving status pending.\n",
3143 WSTOPSIG (lwp->status_pending), lwpid_of (lwp));
3150 /* No resume action for this thread. */
3157 /* Set *FLAG_P if this lwp has an interesting status pending. */
3159 resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p)
3161 struct lwp_info *lwp = (struct lwp_info *) entry;
3163 /* LWPs which will not be resumed are not interesting, because
3164 we might not wait for them next time through linux_wait. */
3165 if (lwp->resume == NULL)
3168 if (lwp->status_pending_p)
3169 * (int *) flag_p = 1;
3174 /* Return 1 if this lwp that GDB wants running is stopped at an
3175 internal breakpoint that we need to step over. It assumes that any
3176 required STOP_PC adjustment has already been propagated to the
3177 inferior's regcache. */
3180 need_step_over_p (struct inferior_list_entry *entry, void *dummy)
3182 struct lwp_info *lwp = (struct lwp_info *) entry;
3183 struct thread_info *thread;
3184 struct thread_info *saved_inferior;
3187 /* LWPs which will not be resumed are not interesting, because we
3188 might not wait for them next time through linux_wait. */
3194 "Need step over [LWP %ld]? Ignoring, not stopped\n",
3199 thread = get_lwp_thread (lwp);
3201 if (thread->last_resume_kind == resume_stop)
3205 "Need step over [LWP %ld]? Ignoring, should remain stopped\n",
3210 gdb_assert (lwp->suspended >= 0);
3216 "Need step over [LWP %ld]? Ignoring, suspended\n",
3221 if (!lwp->need_step_over)
3225 "Need step over [LWP %ld]? No\n", lwpid_of (lwp));
3228 if (lwp->status_pending_p)
3232 "Need step over [LWP %ld]? Ignoring, has pending status.\n",
3237 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
3241 /* If the PC has changed since we stopped, then don't do anything,
3242 and let the breakpoint/tracepoint be hit. This happens if, for
3243 instance, GDB handled the decr_pc_after_break subtraction itself,
3244 GDB is OOL stepping this thread, or the user has issued a "jump"
3245 command, or poked thread's registers herself. */
3246 if (pc != lwp->stop_pc)
3250 "Need step over [LWP %ld]? Cancelling, PC was changed. "
3251 "Old stop_pc was 0x%s, PC is now 0x%s\n",
3252 lwpid_of (lwp), paddress (lwp->stop_pc), paddress (pc));
3254 lwp->need_step_over = 0;
3258 saved_inferior = current_inferior;
3259 current_inferior = thread;
3261 /* We can only step over breakpoints we know about. */
3262 if (breakpoint_here (pc) || fast_tracepoint_jump_here (pc))
3264 /* Don't step over a breakpoint that GDB expects to hit
3265 though. If the condition is being evaluated on the target's side
3266 and it evaluate to false, step over this breakpoint as well. */
3267 if (gdb_breakpoint_here (pc)
3268 && gdb_condition_true_at_breakpoint (pc))
3272 "Need step over [LWP %ld]? yes, but found"
3273 " GDB breakpoint at 0x%s; skipping step over\n",
3274 lwpid_of (lwp), paddress (pc));
3276 current_inferior = saved_inferior;
3283 "Need step over [LWP %ld]? yes, "
3284 "found breakpoint at 0x%s\n",
3285 lwpid_of (lwp), paddress (pc));
3287 /* We've found an lwp that needs stepping over --- return 1 so
3288 that find_inferior stops looking. */
3289 current_inferior = saved_inferior;
3291 /* If the step over is cancelled, this is set again. */
3292 lwp->need_step_over = 0;
3297 current_inferior = saved_inferior;
3301 "Need step over [LWP %ld]? No, no breakpoint found at 0x%s\n",
3302 lwpid_of (lwp), paddress (pc));
3307 /* Start a step-over operation on LWP. When LWP stopped at a
3308 breakpoint, to make progress, we need to remove the breakpoint out
3309 of the way. If we let other threads run while we do that, they may
3310 pass by the breakpoint location and miss hitting it. To avoid
3311 that, a step-over momentarily stops all threads while LWP is
3312 single-stepped while the breakpoint is temporarily uninserted from
3313 the inferior. When the single-step finishes, we reinsert the
3314 breakpoint, and let all threads that are supposed to be running,
3317 On targets that don't support hardware single-step, we don't
3318 currently support full software single-stepping. Instead, we only
3319 support stepping over the thread event breakpoint, by asking the
3320 low target where to place a reinsert breakpoint. Since this
3321 routine assumes the breakpoint being stepped over is a thread event
3322 breakpoint, it usually assumes the return address of the current
3323 function is a good enough place to set the reinsert breakpoint. */
3326 start_step_over (struct lwp_info *lwp)
3328 struct thread_info *saved_inferior;
3334 "Starting step-over on LWP %ld. Stopping all threads\n",
3337 stop_all_lwps (1, lwp);
3338 gdb_assert (lwp->suspended == 0);
3341 fprintf (stderr, "Done stopping all threads for step-over.\n");
3343 /* Note, we should always reach here with an already adjusted PC,
3344 either by GDB (if we're resuming due to GDB's request), or by our
3345 caller, if we just finished handling an internal breakpoint GDB
3346 shouldn't care about. */
3349 saved_inferior = current_inferior;
3350 current_inferior = get_lwp_thread (lwp);
3352 lwp->bp_reinsert = pc;
3353 uninsert_breakpoints_at (pc);
3354 uninsert_fast_tracepoint_jumps_at (pc);
3356 if (can_hardware_single_step ())
3362 CORE_ADDR raddr = (*the_low_target.breakpoint_reinsert_addr) ();
3363 set_reinsert_breakpoint (raddr);
3367 current_inferior = saved_inferior;
3369 linux_resume_one_lwp (lwp, step, 0, NULL);
3371 /* Require next event from this LWP. */
3372 step_over_bkpt = lwp->head.id;
3376 /* Finish a step-over. Reinsert the breakpoint we had uninserted in
3377 start_step_over, if still there, and delete any reinsert
3378 breakpoints we've set, on non hardware single-step targets. */
3381 finish_step_over (struct lwp_info *lwp)
3383 if (lwp->bp_reinsert != 0)
3386 fprintf (stderr, "Finished step over.\n");
3388 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
3389 may be no breakpoint to reinsert there by now. */
3390 reinsert_breakpoints_at (lwp->bp_reinsert);
3391 reinsert_fast_tracepoint_jumps_at (lwp->bp_reinsert);
3393 lwp->bp_reinsert = 0;
3395 /* Delete any software-single-step reinsert breakpoints. No
3396 longer needed. We don't have to worry about other threads
3397 hitting this trap, and later not being able to explain it,
3398 because we were stepping over a breakpoint, and we hold all
3399 threads but LWP stopped while doing that. */
3400 if (!can_hardware_single_step ())
3401 delete_reinsert_breakpoints ();
3403 step_over_bkpt = null_ptid;
3410 /* This function is called once per thread. We check the thread's resume
3411 request, which will tell us whether to resume, step, or leave the thread
3412 stopped; and what signal, if any, it should be sent.
3414 For threads which we aren't explicitly told otherwise, we preserve
3415 the stepping flag; this is used for stepping over gdbserver-placed
3418 If pending_flags was set in any thread, we queue any needed
3419 signals, since we won't actually resume. We already have a pending
3420 event to report, so we don't need to preserve any step requests;
3421 they should be re-issued if necessary. */
3424 linux_resume_one_thread (struct inferior_list_entry *entry, void *arg)
3426 struct lwp_info *lwp;
3427 struct thread_info *thread;
3429 int leave_all_stopped = * (int *) arg;
3432 thread = (struct thread_info *) entry;
3433 lwp = get_thread_lwp (thread);
3435 if (lwp->resume == NULL)
3438 if (lwp->resume->kind == resume_stop)
3441 fprintf (stderr, "resume_stop request for LWP %ld\n", lwpid_of (lwp));
3446 fprintf (stderr, "stopping LWP %ld\n", lwpid_of (lwp));
3448 /* Stop the thread, and wait for the event asynchronously,
3449 through the event loop. */
3455 fprintf (stderr, "already stopped LWP %ld\n",
3458 /* The LWP may have been stopped in an internal event that
3459 was not meant to be notified back to GDB (e.g., gdbserver
3460 breakpoint), so we should be reporting a stop event in
3463 /* If the thread already has a pending SIGSTOP, this is a
3464 no-op. Otherwise, something later will presumably resume
3465 the thread and this will cause it to cancel any pending
3466 operation, due to last_resume_kind == resume_stop. If
3467 the thread already has a pending status to report, we
3468 will still report it the next time we wait - see
3469 status_pending_p_callback. */
3471 /* If we already have a pending signal to report, then
3472 there's no need to queue a SIGSTOP, as this means we're
3473 midway through moving the LWP out of the jumppad, and we
3474 will report the pending signal as soon as that is
3476 if (lwp->pending_signals_to_report == NULL)
3480 /* For stop requests, we're done. */
3482 thread->last_status.kind = TARGET_WAITKIND_IGNORE;
3486 /* If this thread which is about to be resumed has a pending status,
3487 then don't resume any threads - we can just report the pending
3488 status. Make sure to queue any signals that would otherwise be
3489 sent. In all-stop mode, we do this decision based on if *any*
3490 thread has a pending status. If there's a thread that needs the
3491 step-over-breakpoint dance, then don't resume any other thread
3492 but that particular one. */
3493 leave_pending = (lwp->status_pending_p || leave_all_stopped);
3498 fprintf (stderr, "resuming LWP %ld\n", lwpid_of (lwp));
3500 step = (lwp->resume->kind == resume_step);
3501 linux_resume_one_lwp (lwp, step, lwp->resume->sig, NULL);
3506 fprintf (stderr, "leaving LWP %ld stopped\n", lwpid_of (lwp));
3508 /* If we have a new signal, enqueue the signal. */
3509 if (lwp->resume->sig != 0)
3511 struct pending_signals *p_sig;
3512 p_sig = xmalloc (sizeof (*p_sig));
3513 p_sig->prev = lwp->pending_signals;
3514 p_sig->signal = lwp->resume->sig;
3515 memset (&p_sig->info, 0, sizeof (siginfo_t));
3517 /* If this is the same signal we were previously stopped by,
3518 make sure to queue its siginfo. We can ignore the return
3519 value of ptrace; if it fails, we'll skip
3520 PTRACE_SETSIGINFO. */
3521 if (WIFSTOPPED (lwp->last_status)
3522 && WSTOPSIG (lwp->last_status) == lwp->resume->sig)
3523 ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info);
3525 lwp->pending_signals = p_sig;
3529 thread->last_status.kind = TARGET_WAITKIND_IGNORE;
3535 linux_resume (struct thread_resume *resume_info, size_t n)
3537 struct thread_resume_array array = { resume_info, n };
3538 struct lwp_info *need_step_over = NULL;
3540 int leave_all_stopped;
3542 find_inferior (&all_threads, linux_set_resume_request, &array);
3544 /* If there is a thread which would otherwise be resumed, which has
3545 a pending status, then don't resume any threads - we can just
3546 report the pending status. Make sure to queue any signals that
3547 would otherwise be sent. In non-stop mode, we'll apply this
3548 logic to each thread individually. We consume all pending events
3549 before considering to start a step-over (in all-stop). */
3552 find_inferior (&all_lwps, resume_status_pending_p, &any_pending);
3554 /* If there is a thread which would otherwise be resumed, which is
3555 stopped at a breakpoint that needs stepping over, then don't
3556 resume any threads - have it step over the breakpoint with all
3557 other threads stopped, then resume all threads again. Make sure
3558 to queue any signals that would otherwise be delivered or
3560 if (!any_pending && supports_breakpoints ())
3562 = (struct lwp_info *) find_inferior (&all_lwps,
3563 need_step_over_p, NULL);
3565 leave_all_stopped = (need_step_over != NULL || any_pending);
3569 if (need_step_over != NULL)
3570 fprintf (stderr, "Not resuming all, need step over\n");
3571 else if (any_pending)
3573 "Not resuming, all-stop and found "
3574 "an LWP with pending status\n");
3576 fprintf (stderr, "Resuming, no pending status or step over needed\n");
3579 /* Even if we're leaving threads stopped, queue all signals we'd
3580 otherwise deliver. */
3581 find_inferior (&all_threads, linux_resume_one_thread, &leave_all_stopped);
3584 start_step_over (need_step_over);
3587 /* This function is called once per thread. We check the thread's
3588 last resume request, which will tell us whether to resume, step, or
3589 leave the thread stopped. Any signal the client requested to be
3590 delivered has already been enqueued at this point.
3592 If any thread that GDB wants running is stopped at an internal
3593 breakpoint that needs stepping over, we start a step-over operation
3594 on that particular thread, and leave all others stopped. */
3597 proceed_one_lwp (struct inferior_list_entry *entry, void *except)
3599 struct lwp_info *lwp = (struct lwp_info *) entry;
3600 struct thread_info *thread;
3608 "proceed_one_lwp: lwp %ld\n", lwpid_of (lwp));
3613 fprintf (stderr, " LWP %ld already running\n", lwpid_of (lwp));
3617 thread = get_lwp_thread (lwp);
3619 if (thread->last_resume_kind == resume_stop
3620 && thread->last_status.kind != TARGET_WAITKIND_IGNORE)
3623 fprintf (stderr, " client wants LWP to remain %ld stopped\n",
3628 if (lwp->status_pending_p)
3631 fprintf (stderr, " LWP %ld has pending status, leaving stopped\n",
3636 gdb_assert (lwp->suspended >= 0);
3641 fprintf (stderr, " LWP %ld is suspended\n", lwpid_of (lwp));
3645 if (thread->last_resume_kind == resume_stop
3646 && lwp->pending_signals_to_report == NULL
3647 && lwp->collecting_fast_tracepoint == 0)
3649 /* We haven't reported this LWP as stopped yet (otherwise, the
3650 last_status.kind check above would catch it, and we wouldn't
3651 reach here. This LWP may have been momentarily paused by a
3652 stop_all_lwps call while handling for example, another LWP's
3653 step-over. In that case, the pending expected SIGSTOP signal
3654 that was queued at vCont;t handling time will have already
3655 been consumed by wait_for_sigstop, and so we need to requeue
3656 another one here. Note that if the LWP already has a SIGSTOP
3657 pending, this is a no-op. */
3661 "Client wants LWP %ld to stop. "
3662 "Making sure it has a SIGSTOP pending\n",
3668 step = thread->last_resume_kind == resume_step;
3669 linux_resume_one_lwp (lwp, step, 0, NULL);
3674 unsuspend_and_proceed_one_lwp (struct inferior_list_entry *entry, void *except)
3676 struct lwp_info *lwp = (struct lwp_info *) entry;
3682 gdb_assert (lwp->suspended >= 0);
3684 return proceed_one_lwp (entry, except);
3687 /* When we finish a step-over, set threads running again. If there's
3688 another thread that may need a step-over, now's the time to start
3689 it. Eventually, we'll move all threads past their breakpoints. */
3692 proceed_all_lwps (void)
3694 struct lwp_info *need_step_over;
3696 /* If there is a thread which would otherwise be resumed, which is
3697 stopped at a breakpoint that needs stepping over, then don't
3698 resume any threads - have it step over the breakpoint with all
3699 other threads stopped, then resume all threads again. */
3701 if (supports_breakpoints ())
3704 = (struct lwp_info *) find_inferior (&all_lwps,
3705 need_step_over_p, NULL);
3707 if (need_step_over != NULL)
3710 fprintf (stderr, "proceed_all_lwps: found "
3711 "thread %ld needing a step-over\n",
3712 lwpid_of (need_step_over));
3714 start_step_over (need_step_over);
3720 fprintf (stderr, "Proceeding, no step-over needed\n");
3722 find_inferior (&all_lwps, proceed_one_lwp, NULL);
3725 /* Stopped LWPs that the client wanted to be running, that don't have
3726 pending statuses, are set to run again, except for EXCEPT, if not
3727 NULL. This undoes a stop_all_lwps call. */
3730 unstop_all_lwps (int unsuspend, struct lwp_info *except)
3736 "unstopping all lwps, except=(LWP %ld)\n", lwpid_of (except));
3739 "unstopping all lwps\n");
3743 find_inferior (&all_lwps, unsuspend_and_proceed_one_lwp, except);
3745 find_inferior (&all_lwps, proceed_one_lwp, except);
3748 #ifdef HAVE_LINUX_USRREGS
3751 register_addr (int regnum)
3755 if (regnum < 0 || regnum >= the_low_target.num_regs)
3756 error ("Invalid register number %d.", regnum);
3758 addr = the_low_target.regmap[regnum];
3763 /* Fetch one register. */
3765 fetch_register (struct regcache *regcache, int regno)
3772 if (regno >= the_low_target.num_regs)
3774 if ((*the_low_target.cannot_fetch_register) (regno))
3777 regaddr = register_addr (regno);
3781 size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
3782 & -sizeof (PTRACE_XFER_TYPE));
3783 buf = alloca (size);
3785 pid = lwpid_of (get_thread_lwp (current_inferior));
3786 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
3789 *(PTRACE_XFER_TYPE *) (buf + i) =
3790 ptrace (PTRACE_PEEKUSER, pid,
3791 /* Coerce to a uintptr_t first to avoid potential gcc warning
3792 of coercing an 8 byte integer to a 4 byte pointer. */
3793 (PTRACE_ARG3_TYPE) (uintptr_t) regaddr, 0);
3794 regaddr += sizeof (PTRACE_XFER_TYPE);
3796 error ("reading register %d: %s", regno, strerror (errno));
3799 if (the_low_target.supply_ptrace_register)
3800 the_low_target.supply_ptrace_register (regcache, regno, buf);
3802 supply_register (regcache, regno, buf);
3805 /* Store one register. */
3807 store_register (struct regcache *regcache, int regno)
3814 if (regno >= the_low_target.num_regs)
3816 if ((*the_low_target.cannot_store_register) (regno))
3819 regaddr = register_addr (regno);
3823 size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
3824 & -sizeof (PTRACE_XFER_TYPE));
3825 buf = alloca (size);
3826 memset (buf, 0, size);
3828 if (the_low_target.collect_ptrace_register)
3829 the_low_target.collect_ptrace_register (regcache, regno, buf);
3831 collect_register (regcache, regno, buf);
3833 pid = lwpid_of (get_thread_lwp (current_inferior));
3834 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
3837 ptrace (PTRACE_POKEUSER, pid,
3838 /* Coerce to a uintptr_t first to avoid potential gcc warning
3839 about coercing an 8 byte integer to a 4 byte pointer. */
3840 (PTRACE_ARG3_TYPE) (uintptr_t) regaddr,
3841 (PTRACE_ARG4_TYPE) *(PTRACE_XFER_TYPE *) (buf + i));
3844 /* At this point, ESRCH should mean the process is
3845 already gone, in which case we simply ignore attempts
3846 to change its registers. See also the related
3847 comment in linux_resume_one_lwp. */
3851 if ((*the_low_target.cannot_store_register) (regno) == 0)
3852 error ("writing register %d: %s", regno, strerror (errno));
3854 regaddr += sizeof (PTRACE_XFER_TYPE);
3858 /* Fetch all registers, or just one, from the child process. */
3860 usr_fetch_inferior_registers (struct regcache *regcache, int regno)
3863 for (regno = 0; regno < the_low_target.num_regs; regno++)
3864 fetch_register (regcache, regno);
3866 fetch_register (regcache, regno);
3869 /* Store our register values back into the inferior.
3870 If REGNO is -1, do this for all registers.
3871 Otherwise, REGNO specifies which register (so we can save time). */
3873 usr_store_inferior_registers (struct regcache *regcache, int regno)
3876 for (regno = 0; regno < the_low_target.num_regs; regno++)
3877 store_register (regcache, regno);
3879 store_register (regcache, regno);
3881 #endif /* HAVE_LINUX_USRREGS */
3885 #ifdef HAVE_LINUX_REGSETS
3888 regsets_fetch_inferior_registers (struct regcache *regcache)
3890 struct regset_info *regset;
3891 int saw_general_regs = 0;
3895 regset = target_regsets;
3897 pid = lwpid_of (get_thread_lwp (current_inferior));
3898 while (regset->size >= 0)
3903 if (regset->size == 0 || disabled_regsets[regset - target_regsets])
3909 buf = xmalloc (regset->size);
3911 nt_type = regset->nt_type;
3915 iov.iov_len = regset->size;
3916 data = (void *) &iov;
3922 res = ptrace (regset->get_request, pid, nt_type, data);
3924 res = ptrace (regset->get_request, pid, data, nt_type);
3930 /* If we get EIO on a regset, do not try it again for
3932 disabled_regsets[regset - target_regsets] = 1;
3939 sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d",
3944 else if (regset->type == GENERAL_REGS)
3945 saw_general_regs = 1;
3946 regset->store_function (regcache, buf);
3950 if (saw_general_regs)
3957 regsets_store_inferior_registers (struct regcache *regcache)
3959 struct regset_info *regset;
3960 int saw_general_regs = 0;
3964 regset = target_regsets;
3966 pid = lwpid_of (get_thread_lwp (current_inferior));
3967 while (regset->size >= 0)
3972 if (regset->size == 0 || disabled_regsets[regset - target_regsets])
3978 buf = xmalloc (regset->size);
3980 /* First fill the buffer with the current register set contents,
3981 in case there are any items in the kernel's regset that are
3982 not in gdbserver's regcache. */
3984 nt_type = regset->nt_type;
3988 iov.iov_len = regset->size;
3989 data = (void *) &iov;
3995 res = ptrace (regset->get_request, pid, nt_type, data);
3997 res = ptrace (regset->get_request, pid, &iov, data);
4002 /* Then overlay our cached registers on that. */
4003 regset->fill_function (regcache, buf);
4005 /* Only now do we write the register set. */
4007 res = ptrace (regset->set_request, pid, nt_type, data);
4009 res = ptrace (regset->set_request, pid, data, nt_type);
4017 /* If we get EIO on a regset, do not try it again for
4019 disabled_regsets[regset - target_regsets] = 1;
4023 else if (errno == ESRCH)
4025 /* At this point, ESRCH should mean the process is
4026 already gone, in which case we simply ignore attempts
4027 to change its registers. See also the related
4028 comment in linux_resume_one_lwp. */
4034 perror ("Warning: ptrace(regsets_store_inferior_registers)");
4037 else if (regset->type == GENERAL_REGS)
4038 saw_general_regs = 1;
4042 if (saw_general_regs)
4049 #endif /* HAVE_LINUX_REGSETS */
4053 linux_fetch_registers (struct regcache *regcache, int regno)
4055 #ifdef HAVE_LINUX_REGSETS
4056 if (regsets_fetch_inferior_registers (regcache) == 0)
4059 #ifdef HAVE_LINUX_USRREGS
4060 usr_fetch_inferior_registers (regcache, regno);
4065 linux_store_registers (struct regcache *regcache, int regno)
4067 #ifdef HAVE_LINUX_REGSETS
4068 if (regsets_store_inferior_registers (regcache) == 0)
4071 #ifdef HAVE_LINUX_USRREGS
4072 usr_store_inferior_registers (regcache, regno);
4077 /* Copy LEN bytes from inferior's memory starting at MEMADDR
4078 to debugger memory starting at MYADDR. */
4081 linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
4084 /* Round starting address down to longword boundary. */
4085 register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
4086 /* Round ending address up; get number of longwords that makes. */
4088 = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
4089 / sizeof (PTRACE_XFER_TYPE);
4090 /* Allocate buffer of that many longwords. */
4091 register PTRACE_XFER_TYPE *buffer
4092 = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
4095 int pid = lwpid_of (get_thread_lwp (current_inferior));
4097 /* Try using /proc. Don't bother for one word. */
4098 if (len >= 3 * sizeof (long))
4100 /* We could keep this file open and cache it - possibly one per
4101 thread. That requires some juggling, but is even faster. */
4102 sprintf (filename, "/proc/%d/mem", pid);
4103 fd = open (filename, O_RDONLY | O_LARGEFILE);
4107 /* If pread64 is available, use it. It's faster if the kernel
4108 supports it (only one syscall), and it's 64-bit safe even on
4109 32-bit platforms (for instance, SPARC debugging a SPARC64
4112 if (pread64 (fd, myaddr, len, memaddr) != len)
4114 if (lseek (fd, memaddr, SEEK_SET) == -1 || read (fd, myaddr, len) != len)
4126 /* Read all the longwords */
4127 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
4130 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
4131 about coercing an 8 byte integer to a 4 byte pointer. */
4132 buffer[i] = ptrace (PTRACE_PEEKTEXT, pid,
4133 (PTRACE_ARG3_TYPE) (uintptr_t) addr, 0);
4138 /* Copy appropriate bytes out of the buffer. */
4140 (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
4146 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
4147 memory at MEMADDR. On failure (cannot write to the inferior)
4148 returns the value of errno. */
4151 linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
4154 /* Round starting address down to longword boundary. */
4155 register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
4156 /* Round ending address up; get number of longwords that makes. */
4158 = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
4159 / sizeof (PTRACE_XFER_TYPE);
4161 /* Allocate buffer of that many longwords. */
4162 register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *)
4163 alloca (count * sizeof (PTRACE_XFER_TYPE));
4165 int pid = lwpid_of (get_thread_lwp (current_inferior));
4169 /* Dump up to four bytes. */
4170 unsigned int val = * (unsigned int *) myaddr;
4176 val = val & 0xffffff;
4177 fprintf (stderr, "Writing %0*x to 0x%08lx\n", 2 * ((len < 4) ? len : 4),
4178 val, (long)memaddr);
4181 /* Fill start and end extra bytes of buffer with existing memory data. */
4184 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
4185 about coercing an 8 byte integer to a 4 byte pointer. */
4186 buffer[0] = ptrace (PTRACE_PEEKTEXT, pid,
4187 (PTRACE_ARG3_TYPE) (uintptr_t) addr, 0);
4195 = ptrace (PTRACE_PEEKTEXT, pid,
4196 /* Coerce to a uintptr_t first to avoid potential gcc warning
4197 about coercing an 8 byte integer to a 4 byte pointer. */
4198 (PTRACE_ARG3_TYPE) (uintptr_t) (addr + (count - 1)
4199 * sizeof (PTRACE_XFER_TYPE)),
4205 /* Copy data to be written over corresponding part of buffer. */
4207 memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
4210 /* Write the entire buffer. */
4212 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
4215 ptrace (PTRACE_POKETEXT, pid,
4216 /* Coerce to a uintptr_t first to avoid potential gcc warning
4217 about coercing an 8 byte integer to a 4 byte pointer. */
4218 (PTRACE_ARG3_TYPE) (uintptr_t) addr,
4219 (PTRACE_ARG4_TYPE) buffer[i]);
4227 /* Non-zero if the kernel supports PTRACE_O_TRACEFORK. */
4228 static int linux_supports_tracefork_flag;
4231 linux_enable_event_reporting (int pid)
4233 if (!linux_supports_tracefork_flag)
4236 ptrace (PTRACE_SETOPTIONS, pid, 0, (PTRACE_ARG4_TYPE) PTRACE_O_TRACECLONE);
4239 /* Helper functions for linux_test_for_tracefork, called via clone (). */
4242 linux_tracefork_grandchild (void *arg)
4247 #define STACK_SIZE 4096
4250 linux_tracefork_child (void *arg)
4252 ptrace (PTRACE_TRACEME, 0, 0, 0);
4253 kill (getpid (), SIGSTOP);
4255 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
4258 linux_tracefork_grandchild (NULL);
4260 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4263 __clone2 (linux_tracefork_grandchild, arg, STACK_SIZE,
4264 CLONE_VM | SIGCHLD, NULL);
4266 clone (linux_tracefork_grandchild, (char *) arg + STACK_SIZE,
4267 CLONE_VM | SIGCHLD, NULL);
4270 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4275 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
4276 sure that we can enable the option, and that it had the desired
4280 linux_test_for_tracefork (void)
4282 int child_pid, ret, status;
4284 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4285 char *stack = xmalloc (STACK_SIZE * 4);
4286 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4288 linux_supports_tracefork_flag = 0;
4290 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
4292 child_pid = fork ();
4294 linux_tracefork_child (NULL);
4296 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4298 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
4300 child_pid = __clone2 (linux_tracefork_child, stack, STACK_SIZE,
4301 CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
4302 #else /* !__ia64__ */
4303 child_pid = clone (linux_tracefork_child, stack + STACK_SIZE,
4304 CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
4305 #endif /* !__ia64__ */
4307 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4309 if (child_pid == -1)
4310 perror_with_name ("clone");
4312 ret = my_waitpid (child_pid, &status, 0);
4314 perror_with_name ("waitpid");
4315 else if (ret != child_pid)
4316 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret);
4317 if (! WIFSTOPPED (status))
4318 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status);
4320 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0,
4321 (PTRACE_ARG4_TYPE) PTRACE_O_TRACEFORK);
4324 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
4327 warning ("linux_test_for_tracefork: failed to kill child");
4331 ret = my_waitpid (child_pid, &status, 0);
4332 if (ret != child_pid)
4333 warning ("linux_test_for_tracefork: failed to wait for killed child");
4334 else if (!WIFSIGNALED (status))
4335 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
4336 "killed child", status);
4341 ret = ptrace (PTRACE_CONT, child_pid, 0, 0);
4343 warning ("linux_test_for_tracefork: failed to resume child");
4345 ret = my_waitpid (child_pid, &status, 0);
4347 if (ret == child_pid && WIFSTOPPED (status)
4348 && status >> 16 == PTRACE_EVENT_FORK)
4351 ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
4352 if (ret == 0 && second_pid != 0)
4356 linux_supports_tracefork_flag = 1;
4357 my_waitpid (second_pid, &second_status, 0);
4358 ret = ptrace (PTRACE_KILL, second_pid, 0, 0);
4360 warning ("linux_test_for_tracefork: failed to kill second child");
4361 my_waitpid (second_pid, &status, 0);
4365 warning ("linux_test_for_tracefork: unexpected result from waitpid "
4366 "(%d, status 0x%x)", ret, status);
4370 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
4372 warning ("linux_test_for_tracefork: failed to kill child");
4373 my_waitpid (child_pid, &status, 0);
4375 while (WIFSTOPPED (status));
4377 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4379 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4384 linux_look_up_symbols (void)
4386 #ifdef USE_THREAD_DB
4387 struct process_info *proc = current_process ();
4389 if (proc->private->thread_db != NULL)
4392 /* If the kernel supports tracing forks then it also supports tracing
4393 clones, and then we don't need to use the magic thread event breakpoint
4394 to learn about threads. */
4395 thread_db_init (!linux_supports_tracefork_flag);
4400 linux_request_interrupt (void)
4402 extern unsigned long signal_pid;
4404 if (!ptid_equal (cont_thread, null_ptid)
4405 && !ptid_equal (cont_thread, minus_one_ptid))
4407 struct lwp_info *lwp;
4410 lwp = get_thread_lwp (current_inferior);
4411 lwpid = lwpid_of (lwp);
4412 kill_lwp (lwpid, SIGINT);
4415 kill_lwp (signal_pid, SIGINT);
4418 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
4419 to debugger memory starting at MYADDR. */
4422 linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len)
4424 char filename[PATH_MAX];
4426 int pid = lwpid_of (get_thread_lwp (current_inferior));
4428 xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
4430 fd = open (filename, O_RDONLY);
4434 if (offset != (CORE_ADDR) 0
4435 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
4438 n = read (fd, myaddr, len);
4445 /* These breakpoint and watchpoint related wrapper functions simply
4446 pass on the function call if the target has registered a
4447 corresponding function. */
4450 linux_insert_point (char type, CORE_ADDR addr, int len)
4452 if (the_low_target.insert_point != NULL)
4453 return the_low_target.insert_point (type, addr, len);
4455 /* Unsupported (see target.h). */
4460 linux_remove_point (char type, CORE_ADDR addr, int len)
4462 if (the_low_target.remove_point != NULL)
4463 return the_low_target.remove_point (type, addr, len);
4465 /* Unsupported (see target.h). */
4470 linux_stopped_by_watchpoint (void)
4472 struct lwp_info *lwp = get_thread_lwp (current_inferior);
4474 return lwp->stopped_by_watchpoint;
4478 linux_stopped_data_address (void)
4480 struct lwp_info *lwp = get_thread_lwp (current_inferior);
4482 return lwp->stopped_data_address;
4485 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4486 #if defined(__mcoldfire__)
4487 /* These should really be defined in the kernel's ptrace.h header. */
4488 #define PT_TEXT_ADDR 49*4
4489 #define PT_DATA_ADDR 50*4
4490 #define PT_TEXT_END_ADDR 51*4
4492 #define PT_TEXT_ADDR 220
4493 #define PT_TEXT_END_ADDR 224
4494 #define PT_DATA_ADDR 228
4495 #elif defined(__TMS320C6X__)
4496 #define PT_TEXT_ADDR (0x10000*4)
4497 #define PT_DATA_ADDR (0x10004*4)
4498 #define PT_TEXT_END_ADDR (0x10008*4)
4501 /* Under uClinux, programs are loaded at non-zero offsets, which we need
4502 to tell gdb about. */
4505 linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p)
4507 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
4508 unsigned long text, text_end, data;
4509 int pid = lwpid_of (get_thread_lwp (current_inferior));
4513 text = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_ADDR, 0);
4514 text_end = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_END_ADDR, 0);
4515 data = ptrace (PTRACE_PEEKUSER, pid, (long)PT_DATA_ADDR, 0);
4519 /* Both text and data offsets produced at compile-time (and so
4520 used by gdb) are relative to the beginning of the program,
4521 with the data segment immediately following the text segment.
4522 However, the actual runtime layout in memory may put the data
4523 somewhere else, so when we send gdb a data base-address, we
4524 use the real data base address and subtract the compile-time
4525 data base-address from it (which is just the length of the
4526 text segment). BSS immediately follows data in both
4529 *data_p = data - (text_end - text);
4539 linux_qxfer_osdata (const char *annex,
4540 unsigned char *readbuf, unsigned const char *writebuf,
4541 CORE_ADDR offset, int len)
4543 return linux_common_xfer_osdata (annex, readbuf, offset, len);
4546 /* Convert a native/host siginfo object, into/from the siginfo in the
4547 layout of the inferiors' architecture. */
4550 siginfo_fixup (struct siginfo *siginfo, void *inf_siginfo, int direction)
4554 if (the_low_target.siginfo_fixup != NULL)
4555 done = the_low_target.siginfo_fixup (siginfo, inf_siginfo, direction);
4557 /* If there was no callback, or the callback didn't do anything,
4558 then just do a straight memcpy. */
4562 memcpy (siginfo, inf_siginfo, sizeof (struct siginfo));
4564 memcpy (inf_siginfo, siginfo, sizeof (struct siginfo));
4569 linux_xfer_siginfo (const char *annex, unsigned char *readbuf,
4570 unsigned const char *writebuf, CORE_ADDR offset, int len)
4573 struct siginfo siginfo;
4574 char inf_siginfo[sizeof (struct siginfo)];
4576 if (current_inferior == NULL)
4579 pid = lwpid_of (get_thread_lwp (current_inferior));
4582 fprintf (stderr, "%s siginfo for lwp %d.\n",
4583 readbuf != NULL ? "Reading" : "Writing",
4586 if (offset >= sizeof (siginfo))
4589 if (ptrace (PTRACE_GETSIGINFO, pid, 0, &siginfo) != 0)
4592 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
4593 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
4594 inferior with a 64-bit GDBSERVER should look the same as debugging it
4595 with a 32-bit GDBSERVER, we need to convert it. */
4596 siginfo_fixup (&siginfo, inf_siginfo, 0);
4598 if (offset + len > sizeof (siginfo))
4599 len = sizeof (siginfo) - offset;
4601 if (readbuf != NULL)
4602 memcpy (readbuf, inf_siginfo + offset, len);
4605 memcpy (inf_siginfo + offset, writebuf, len);
4607 /* Convert back to ptrace layout before flushing it out. */
4608 siginfo_fixup (&siginfo, inf_siginfo, 1);
4610 if (ptrace (PTRACE_SETSIGINFO, pid, 0, &siginfo) != 0)
4617 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4618 so we notice when children change state; as the handler for the
4619 sigsuspend in my_waitpid. */
4622 sigchld_handler (int signo)
4624 int old_errno = errno;
4630 /* fprintf is not async-signal-safe, so call write
4632 if (write (2, "sigchld_handler\n",
4633 sizeof ("sigchld_handler\n") - 1) < 0)
4634 break; /* just ignore */
4638 if (target_is_async_p ())
4639 async_file_mark (); /* trigger a linux_wait */
4645 linux_supports_non_stop (void)
4651 linux_async (int enable)
4653 int previous = (linux_event_pipe[0] != -1);
4656 fprintf (stderr, "linux_async (%d), previous=%d\n",
4659 if (previous != enable)
4662 sigemptyset (&mask);
4663 sigaddset (&mask, SIGCHLD);
4665 sigprocmask (SIG_BLOCK, &mask, NULL);
4669 if (pipe (linux_event_pipe) == -1)
4670 fatal ("creating event pipe failed.");
4672 fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK);
4673 fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK);
4675 /* Register the event loop handler. */
4676 add_file_handler (linux_event_pipe[0],
4677 handle_target_event, NULL);
4679 /* Always trigger a linux_wait. */
4684 delete_file_handler (linux_event_pipe[0]);
4686 close (linux_event_pipe[0]);
4687 close (linux_event_pipe[1]);
4688 linux_event_pipe[0] = -1;
4689 linux_event_pipe[1] = -1;
4692 sigprocmask (SIG_UNBLOCK, &mask, NULL);
4699 linux_start_non_stop (int nonstop)
4701 /* Register or unregister from event-loop accordingly. */
4702 linux_async (nonstop);
4707 linux_supports_multi_process (void)
4713 linux_supports_disable_randomization (void)
4715 #ifdef HAVE_PERSONALITY
4722 /* Enumerate spufs IDs for process PID. */
4724 spu_enumerate_spu_ids (long pid, unsigned char *buf, CORE_ADDR offset, int len)
4730 struct dirent *entry;
4732 sprintf (path, "/proc/%ld/fd", pid);
4733 dir = opendir (path);
4738 while ((entry = readdir (dir)) != NULL)
4744 fd = atoi (entry->d_name);
4748 sprintf (path, "/proc/%ld/fd/%d", pid, fd);
4749 if (stat (path, &st) != 0)
4751 if (!S_ISDIR (st.st_mode))
4754 if (statfs (path, &stfs) != 0)
4756 if (stfs.f_type != SPUFS_MAGIC)
4759 if (pos >= offset && pos + 4 <= offset + len)
4761 *(unsigned int *)(buf + pos - offset) = fd;
4771 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
4772 object type, using the /proc file system. */
4774 linux_qxfer_spu (const char *annex, unsigned char *readbuf,
4775 unsigned const char *writebuf,
4776 CORE_ADDR offset, int len)
4778 long pid = lwpid_of (get_thread_lwp (current_inferior));
4783 if (!writebuf && !readbuf)
4791 return spu_enumerate_spu_ids (pid, readbuf, offset, len);
4794 sprintf (buf, "/proc/%ld/fd/%s", pid, annex);
4795 fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
4800 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
4807 ret = write (fd, writebuf, (size_t) len);
4809 ret = read (fd, readbuf, (size_t) len);
4815 #if defined PT_GETDSBT || defined PTRACE_GETFDPIC
4816 struct target_loadseg
4818 /* Core address to which the segment is mapped. */
4820 /* VMA recorded in the program header. */
4822 /* Size of this segment in memory. */
4826 # if defined PT_GETDSBT
4827 struct target_loadmap
4829 /* Protocol version number, must be zero. */
4831 /* Pointer to the DSBT table, its size, and the DSBT index. */
4832 unsigned *dsbt_table;
4833 unsigned dsbt_size, dsbt_index;
4834 /* Number of segments in this map. */
4836 /* The actual memory map. */
4837 struct target_loadseg segs[/*nsegs*/];
4839 # define LINUX_LOADMAP PT_GETDSBT
4840 # define LINUX_LOADMAP_EXEC PTRACE_GETDSBT_EXEC
4841 # define LINUX_LOADMAP_INTERP PTRACE_GETDSBT_INTERP
4843 struct target_loadmap
4845 /* Protocol version number, must be zero. */
4847 /* Number of segments in this map. */
4849 /* The actual memory map. */
4850 struct target_loadseg segs[/*nsegs*/];
4852 # define LINUX_LOADMAP PTRACE_GETFDPIC
4853 # define LINUX_LOADMAP_EXEC PTRACE_GETFDPIC_EXEC
4854 # define LINUX_LOADMAP_INTERP PTRACE_GETFDPIC_INTERP
4858 linux_read_loadmap (const char *annex, CORE_ADDR offset,
4859 unsigned char *myaddr, unsigned int len)
4861 int pid = lwpid_of (get_thread_lwp (current_inferior));
4863 struct target_loadmap *data = NULL;
4864 unsigned int actual_length, copy_length;
4866 if (strcmp (annex, "exec") == 0)
4867 addr = (int) LINUX_LOADMAP_EXEC;
4868 else if (strcmp (annex, "interp") == 0)
4869 addr = (int) LINUX_LOADMAP_INTERP;
4873 if (ptrace (LINUX_LOADMAP, pid, addr, &data) != 0)
4879 actual_length = sizeof (struct target_loadmap)
4880 + sizeof (struct target_loadseg) * data->nsegs;
4882 if (offset < 0 || offset > actual_length)
4885 copy_length = actual_length - offset < len ? actual_length - offset : len;
4886 memcpy (myaddr, (char *) data + offset, copy_length);
4890 # define linux_read_loadmap NULL
4891 #endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */
4894 linux_process_qsupported (const char *query)
4896 if (the_low_target.process_qsupported != NULL)
4897 the_low_target.process_qsupported (query);
4901 linux_supports_tracepoints (void)
4903 if (*the_low_target.supports_tracepoints == NULL)
4906 return (*the_low_target.supports_tracepoints) ();
4910 linux_read_pc (struct regcache *regcache)
4912 if (the_low_target.get_pc == NULL)
4915 return (*the_low_target.get_pc) (regcache);
4919 linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
4921 gdb_assert (the_low_target.set_pc != NULL);
4923 (*the_low_target.set_pc) (regcache, pc);
4927 linux_thread_stopped (struct thread_info *thread)
4929 return get_thread_lwp (thread)->stopped;
4932 /* This exposes stop-all-threads functionality to other modules. */
4935 linux_pause_all (int freeze)
4937 stop_all_lwps (freeze, NULL);
4940 /* This exposes unstop-all-threads functionality to other gdbserver
4944 linux_unpause_all (int unfreeze)
4946 unstop_all_lwps (unfreeze, NULL);
4950 linux_prepare_to_access_memory (void)
4952 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
4955 linux_pause_all (1);
4960 linux_done_accessing_memory (void)
4962 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
4965 linux_unpause_all (1);
4969 linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr,
4970 CORE_ADDR collector,
4973 CORE_ADDR *jump_entry,
4974 CORE_ADDR *trampoline,
4975 ULONGEST *trampoline_size,
4976 unsigned char *jjump_pad_insn,
4977 ULONGEST *jjump_pad_insn_size,
4978 CORE_ADDR *adjusted_insn_addr,
4979 CORE_ADDR *adjusted_insn_addr_end,
4982 return (*the_low_target.install_fast_tracepoint_jump_pad)
4983 (tpoint, tpaddr, collector, lockaddr, orig_size,
4984 jump_entry, trampoline, trampoline_size,
4985 jjump_pad_insn, jjump_pad_insn_size,
4986 adjusted_insn_addr, adjusted_insn_addr_end,
4990 static struct emit_ops *
4991 linux_emit_ops (void)
4993 if (the_low_target.emit_ops != NULL)
4994 return (*the_low_target.emit_ops) ();
5000 linux_get_min_fast_tracepoint_insn_len (void)
5002 return (*the_low_target.get_min_fast_tracepoint_insn_len) ();
5005 /* Extract &phdr and num_phdr in the inferior. Return 0 on success. */
5008 get_phdr_phnum_from_proc_auxv (const int pid, const int is_elf64,
5009 CORE_ADDR *phdr_memaddr, int *num_phdr)
5011 char filename[PATH_MAX];
5013 const int auxv_size = is_elf64
5014 ? sizeof (Elf64_auxv_t) : sizeof (Elf32_auxv_t);
5015 char buf[sizeof (Elf64_auxv_t)]; /* The larger of the two. */
5017 xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
5019 fd = open (filename, O_RDONLY);
5025 while (read (fd, buf, auxv_size) == auxv_size
5026 && (*phdr_memaddr == 0 || *num_phdr == 0))
5030 Elf64_auxv_t *const aux = (Elf64_auxv_t *) buf;
5032 switch (aux->a_type)
5035 *phdr_memaddr = aux->a_un.a_val;
5038 *num_phdr = aux->a_un.a_val;
5044 Elf32_auxv_t *const aux = (Elf32_auxv_t *) buf;
5046 switch (aux->a_type)
5049 *phdr_memaddr = aux->a_un.a_val;
5052 *num_phdr = aux->a_un.a_val;
5060 if (*phdr_memaddr == 0 || *num_phdr == 0)
5062 warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: "
5063 "phdr_memaddr = %ld, phdr_num = %d",
5064 (long) *phdr_memaddr, *num_phdr);
5071 /* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */
5074 get_dynamic (const int pid, const int is_elf64)
5076 CORE_ADDR phdr_memaddr, relocation;
5078 unsigned char *phdr_buf;
5079 const int phdr_size = is_elf64 ? sizeof (Elf64_Phdr) : sizeof (Elf32_Phdr);
5081 if (get_phdr_phnum_from_proc_auxv (pid, is_elf64, &phdr_memaddr, &num_phdr))
5084 gdb_assert (num_phdr < 100); /* Basic sanity check. */
5085 phdr_buf = alloca (num_phdr * phdr_size);
5087 if (linux_read_memory (phdr_memaddr, phdr_buf, num_phdr * phdr_size))
5090 /* Compute relocation: it is expected to be 0 for "regular" executables,
5091 non-zero for PIE ones. */
5093 for (i = 0; relocation == -1 && i < num_phdr; i++)
5096 Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size);
5098 if (p->p_type == PT_PHDR)
5099 relocation = phdr_memaddr - p->p_vaddr;
5103 Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size);
5105 if (p->p_type == PT_PHDR)
5106 relocation = phdr_memaddr - p->p_vaddr;
5109 if (relocation == -1)
5111 warning ("Unexpected missing PT_PHDR");
5115 for (i = 0; i < num_phdr; i++)
5119 Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size);
5121 if (p->p_type == PT_DYNAMIC)
5122 return p->p_vaddr + relocation;
5126 Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size);
5128 if (p->p_type == PT_DYNAMIC)
5129 return p->p_vaddr + relocation;
5136 /* Return &_r_debug in the inferior, or -1 if not present. Return value
5137 can be 0 if the inferior does not yet have the library list initialized. */
5140 get_r_debug (const int pid, const int is_elf64)
5142 CORE_ADDR dynamic_memaddr;
5143 const int dyn_size = is_elf64 ? sizeof (Elf64_Dyn) : sizeof (Elf32_Dyn);
5144 unsigned char buf[sizeof (Elf64_Dyn)]; /* The larger of the two. */
5146 dynamic_memaddr = get_dynamic (pid, is_elf64);
5147 if (dynamic_memaddr == 0)
5148 return (CORE_ADDR) -1;
5150 while (linux_read_memory (dynamic_memaddr, buf, dyn_size) == 0)
5154 Elf64_Dyn *const dyn = (Elf64_Dyn *) buf;
5156 if (dyn->d_tag == DT_DEBUG)
5157 return dyn->d_un.d_val;
5159 if (dyn->d_tag == DT_NULL)
5164 Elf32_Dyn *const dyn = (Elf32_Dyn *) buf;
5166 if (dyn->d_tag == DT_DEBUG)
5167 return dyn->d_un.d_val;
5169 if (dyn->d_tag == DT_NULL)
5173 dynamic_memaddr += dyn_size;
5176 return (CORE_ADDR) -1;
5179 /* Read one pointer from MEMADDR in the inferior. */
5182 read_one_ptr (CORE_ADDR memaddr, CORE_ADDR *ptr, int ptr_size)
5185 return linux_read_memory (memaddr, (unsigned char *) ptr, ptr_size);
5188 struct link_map_offsets
5190 /* Offset and size of r_debug.r_version. */
5191 int r_version_offset;
5193 /* Offset and size of r_debug.r_map. */
5196 /* Offset to l_addr field in struct link_map. */
5199 /* Offset to l_name field in struct link_map. */
5202 /* Offset to l_ld field in struct link_map. */
5205 /* Offset to l_next field in struct link_map. */
5208 /* Offset to l_prev field in struct link_map. */
5212 /* Construct qXfer:libraries:read reply. */
5215 linux_qxfer_libraries_svr4 (const char *annex, unsigned char *readbuf,
5216 unsigned const char *writebuf,
5217 CORE_ADDR offset, int len)
5220 unsigned document_len;
5221 struct process_info_private *const priv = current_process ()->private;
5222 char filename[PATH_MAX];
5225 static const struct link_map_offsets lmo_32bit_offsets =
5227 0, /* r_version offset. */
5228 4, /* r_debug.r_map offset. */
5229 0, /* l_addr offset in link_map. */
5230 4, /* l_name offset in link_map. */
5231 8, /* l_ld offset in link_map. */
5232 12, /* l_next offset in link_map. */
5233 16 /* l_prev offset in link_map. */
5236 static const struct link_map_offsets lmo_64bit_offsets =
5238 0, /* r_version offset. */
5239 8, /* r_debug.r_map offset. */
5240 0, /* l_addr offset in link_map. */
5241 8, /* l_name offset in link_map. */
5242 16, /* l_ld offset in link_map. */
5243 24, /* l_next offset in link_map. */
5244 32 /* l_prev offset in link_map. */
5246 const struct link_map_offsets *lmo;
5248 if (writebuf != NULL)
5250 if (readbuf == NULL)
5253 pid = lwpid_of (get_thread_lwp (current_inferior));
5254 xsnprintf (filename, sizeof filename, "/proc/%d/exe", pid);
5255 is_elf64 = elf_64_file_p (filename);
5256 lmo = is_elf64 ? &lmo_64bit_offsets : &lmo_32bit_offsets;
5258 if (priv->r_debug == 0)
5259 priv->r_debug = get_r_debug (pid, is_elf64);
5261 if (priv->r_debug == (CORE_ADDR) -1 || priv->r_debug == 0)
5263 document = xstrdup ("<library-list-svr4 version=\"1.0\"/>\n");
5267 int allocated = 1024;
5269 const int ptr_size = is_elf64 ? 8 : 4;
5270 CORE_ADDR lm_addr, lm_prev, l_name, l_addr, l_ld, l_next, l_prev;
5271 int r_version, header_done = 0;
5273 document = xmalloc (allocated);
5274 strcpy (document, "<library-list-svr4 version=\"1.0\"");
5275 p = document + strlen (document);
5278 if (linux_read_memory (priv->r_debug + lmo->r_version_offset,
5279 (unsigned char *) &r_version,
5280 sizeof (r_version)) != 0
5283 warning ("unexpected r_debug version %d", r_version);
5287 if (read_one_ptr (priv->r_debug + lmo->r_map_offset,
5288 &lm_addr, ptr_size) != 0)
5290 warning ("unable to read r_map from 0x%lx",
5291 (long) priv->r_debug + lmo->r_map_offset);
5296 while (read_one_ptr (lm_addr + lmo->l_name_offset,
5297 &l_name, ptr_size) == 0
5298 && read_one_ptr (lm_addr + lmo->l_addr_offset,
5299 &l_addr, ptr_size) == 0
5300 && read_one_ptr (lm_addr + lmo->l_ld_offset,
5301 &l_ld, ptr_size) == 0
5302 && read_one_ptr (lm_addr + lmo->l_prev_offset,
5303 &l_prev, ptr_size) == 0
5304 && read_one_ptr (lm_addr + lmo->l_next_offset,
5305 &l_next, ptr_size) == 0)
5307 unsigned char libname[PATH_MAX];
5309 if (lm_prev != l_prev)
5311 warning ("Corrupted shared library list: 0x%lx != 0x%lx",
5312 (long) lm_prev, (long) l_prev);
5316 /* Not checking for error because reading may stop before
5317 we've got PATH_MAX worth of characters. */
5319 linux_read_memory (l_name, libname, sizeof (libname) - 1);
5320 libname[sizeof (libname) - 1] = '\0';
5321 if (libname[0] != '\0')
5323 /* 6x the size for xml_escape_text below. */
5324 size_t len = 6 * strlen ((char *) libname);
5329 /* Terminate `<library-list-svr4'. */
5334 while (allocated < p - document + len + 200)
5336 /* Expand to guarantee sufficient storage. */
5337 uintptr_t document_len = p - document;
5339 document = xrealloc (document, 2 * allocated);
5341 p = document + document_len;
5344 name = xml_escape_text ((char *) libname);
5345 p += sprintf (p, "<library name=\"%s\" lm=\"0x%lx\" "
5346 "l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>",
5347 name, (unsigned long) lm_addr,
5348 (unsigned long) l_addr, (unsigned long) l_ld);
5351 else if (lm_prev == 0)
5353 sprintf (p, " main-lm=\"0x%lx\"", (unsigned long) lm_addr);
5364 strcpy (p, "</library-list-svr4>");
5367 document_len = strlen (document);
5368 if (offset < document_len)
5369 document_len -= offset;
5372 if (len > document_len)
5375 memcpy (readbuf, document + offset, len);
5381 static struct target_ops linux_target_ops = {
5382 linux_create_inferior,
5391 linux_fetch_registers,
5392 linux_store_registers,
5393 linux_prepare_to_access_memory,
5394 linux_done_accessing_memory,
5397 linux_look_up_symbols,
5398 linux_request_interrupt,
5402 linux_stopped_by_watchpoint,
5403 linux_stopped_data_address,
5404 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
5409 #ifdef USE_THREAD_DB
5410 thread_db_get_tls_address,
5415 hostio_last_error_from_errno,
5418 linux_supports_non_stop,
5420 linux_start_non_stop,
5421 linux_supports_multi_process,
5422 #ifdef USE_THREAD_DB
5423 thread_db_handle_monitor_command,
5427 linux_common_core_of_thread,
5429 linux_process_qsupported,
5430 linux_supports_tracepoints,
5433 linux_thread_stopped,
5437 linux_cancel_breakpoints,
5438 linux_stabilize_threads,
5439 linux_install_fast_tracepoint_jump_pad,
5441 linux_supports_disable_randomization,
5442 linux_get_min_fast_tracepoint_insn_len,
5443 linux_qxfer_libraries_svr4,
5447 linux_init_signals ()
5449 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
5450 to find what the cancel signal actually is. */
5451 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
5452 signal (__SIGRTMIN+1, SIG_IGN);
5457 initialize_low (void)
5459 struct sigaction sigchld_action;
5460 memset (&sigchld_action, 0, sizeof (sigchld_action));
5461 set_target_ops (&linux_target_ops);
5462 set_breakpoint_data (the_low_target.breakpoint,
5463 the_low_target.breakpoint_len);
5464 linux_init_signals ();
5465 linux_test_for_tracefork ();
5466 #ifdef HAVE_LINUX_REGSETS
5467 for (num_regsets = 0; target_regsets[num_regsets].size >= 0; num_regsets++)
5469 disabled_regsets = xmalloc (num_regsets);
5472 sigchld_action.sa_handler = sigchld_handler;
5473 sigemptyset (&sigchld_action.sa_mask);
5474 sigchld_action.sa_flags = SA_RESTART;
5475 sigaction (SIGCHLD, &sigchld_action, NULL);