1 /* Low level interface to ptrace, for the remote server for GDB.
2 Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
3 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #include "linux-low.h"
22 #include "linux-osdata.h"
26 #include <sys/param.h>
27 #include <sys/ptrace.h>
28 #include "linux-ptrace.h"
29 #include "linux-procfs.h"
31 #include <sys/ioctl.h>
37 #include <sys/syscall.h>
41 #include <sys/types.h>
47 /* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h
48 then ELFMAG0 will have been defined. If it didn't get included by
49 gdb_proc_service.h then including it will likely introduce a duplicate
50 definition of elf_fpregset_t. */
55 #define SPUFS_MAGIC 0x23c9b64e
58 #ifdef HAVE_PERSONALITY
59 # include <sys/personality.h>
60 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
61 # define ADDR_NO_RANDOMIZE 0x0040000
70 #define W_STOPCODE(sig) ((sig) << 8 | 0x7f)
73 /* This is the kernel's hard limit. Not to be confused with
80 #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
85 /* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
86 representation of the thread ID.
88 ``all_lwps'' is keyed by the process ID - which on Linux is (presently)
89 the same as the LWP ID.
91 ``all_processes'' is keyed by the "overall process ID", which
92 GNU/Linux calls tgid, "thread group ID". */
94 struct inferior_list all_lwps;
96 /* A list of all unknown processes which receive stop signals. Some other
97 process will presumably claim each of these as forked children
100 struct inferior_list stopped_pids;
102 /* FIXME this is a bit of a hack, and could be removed. */
103 int stopping_threads;
105 /* FIXME make into a target method? */
106 int using_threads = 1;
108 /* True if we're presently stabilizing threads (moving them out of
110 static int stabilizing_threads;
112 /* This flag is true iff we've just created or attached to our first
113 inferior but it has not stopped yet. As soon as it does, we need
114 to call the low target's arch_setup callback. Doing this only on
115 the first inferior avoids reinializing the architecture on every
116 inferior, and avoids messing with the register caches of the
117 already running inferiors. NOTE: this assumes all inferiors under
118 control of gdbserver have the same architecture. */
119 static int new_inferior;
121 static void linux_resume_one_lwp (struct lwp_info *lwp,
122 int step, int signal, siginfo_t *info);
123 static void linux_resume (struct thread_resume *resume_info, size_t n);
124 static void stop_all_lwps (int suspend, struct lwp_info *except);
125 static void unstop_all_lwps (int unsuspend, struct lwp_info *except);
126 static int linux_wait_for_event (ptid_t ptid, int *wstat, int options);
127 static void *add_lwp (ptid_t ptid);
128 static int linux_stopped_by_watchpoint (void);
129 static void mark_lwp_dead (struct lwp_info *lwp, int wstat);
130 static void proceed_all_lwps (void);
131 static int finish_step_over (struct lwp_info *lwp);
132 static CORE_ADDR get_stop_pc (struct lwp_info *lwp);
133 static int kill_lwp (unsigned long lwpid, int signo);
134 static void linux_enable_event_reporting (int pid);
136 /* True if the low target can hardware single-step. Such targets
137 don't need a BREAKPOINT_REINSERT_ADDR callback. */
140 can_hardware_single_step (void)
142 return (the_low_target.breakpoint_reinsert_addr == NULL);
145 /* True if the low target supports memory breakpoints. If so, we'll
146 have a GET_PC implementation. */
149 supports_breakpoints (void)
151 return (the_low_target.get_pc != NULL);
154 /* Returns true if this target can support fast tracepoints. This
155 does not mean that the in-process agent has been loaded in the
159 supports_fast_tracepoints (void)
161 return the_low_target.install_fast_tracepoint_jump_pad != NULL;
164 struct pending_signals
168 struct pending_signals *prev;
171 #define PTRACE_ARG3_TYPE void *
172 #define PTRACE_ARG4_TYPE void *
173 #define PTRACE_XFER_TYPE long
175 #ifdef HAVE_LINUX_REGSETS
176 static char *disabled_regsets;
177 static int num_regsets;
180 /* The read/write ends of the pipe registered as waitable file in the
182 static int linux_event_pipe[2] = { -1, -1 };
184 /* True if we're currently in async mode. */
185 #define target_is_async_p() (linux_event_pipe[0] != -1)
187 static void send_sigstop (struct lwp_info *lwp);
188 static void wait_for_sigstop (struct inferior_list_entry *entry);
190 /* Accepts an integer PID; Returns a string representing a file that
191 can be opened to get info for the child process.
192 Space for the result is malloc'd, caller must free. */
195 linux_child_pid_to_exec_file (int pid)
199 name1 = xmalloc (MAXPATHLEN);
200 name2 = xmalloc (MAXPATHLEN);
201 memset (name2, 0, MAXPATHLEN);
203 sprintf (name1, "/proc/%d/exe", pid);
204 if (readlink (name1, name2, MAXPATHLEN) > 0)
216 /* Return non-zero if HEADER is a 64-bit ELF file. */
219 elf_64_header_p (const Elf64_Ehdr *header)
221 return (header->e_ident[EI_MAG0] == ELFMAG0
222 && header->e_ident[EI_MAG1] == ELFMAG1
223 && header->e_ident[EI_MAG2] == ELFMAG2
224 && header->e_ident[EI_MAG3] == ELFMAG3
225 && header->e_ident[EI_CLASS] == ELFCLASS64);
228 /* Return non-zero if FILE is a 64-bit ELF file,
229 zero if the file is not a 64-bit ELF file,
230 and -1 if the file is not accessible or doesn't exist. */
233 elf_64_file_p (const char *file)
238 fd = open (file, O_RDONLY);
242 if (read (fd, &header, sizeof (header)) != sizeof (header))
249 return elf_64_header_p (&header);
253 delete_lwp (struct lwp_info *lwp)
255 remove_thread (get_lwp_thread (lwp));
256 remove_inferior (&all_lwps, &lwp->head);
257 free (lwp->arch_private);
261 /* Add a process to the common process list, and set its private
264 static struct process_info *
265 linux_add_process (int pid, int attached)
267 struct process_info *proc;
269 /* Is this the first process? If so, then set the arch. */
270 if (all_processes.head == NULL)
273 proc = add_process (pid, attached);
274 proc->private = xcalloc (1, sizeof (*proc->private));
276 if (the_low_target.new_process != NULL)
277 proc->private->arch_private = the_low_target.new_process ();
282 /* Wrapper function for waitpid which handles EINTR, and emulates
283 __WALL for systems where that is not available. */
286 my_waitpid (int pid, int *status, int flags)
291 fprintf (stderr, "my_waitpid (%d, 0x%x)\n", pid, flags);
295 sigset_t block_mask, org_mask, wake_mask;
298 wnohang = (flags & WNOHANG) != 0;
299 flags &= ~(__WALL | __WCLONE);
302 /* Block all signals while here. This avoids knowing about
303 LinuxThread's signals. */
304 sigfillset (&block_mask);
305 sigprocmask (SIG_BLOCK, &block_mask, &org_mask);
307 /* ... except during the sigsuspend below. */
308 sigemptyset (&wake_mask);
312 /* Since all signals are blocked, there's no need to check
314 ret = waitpid (pid, status, flags);
317 if (ret == -1 && out_errno != ECHILD)
322 if (flags & __WCLONE)
324 /* We've tried both flavors now. If WNOHANG is set,
325 there's nothing else to do, just bail out. */
330 fprintf (stderr, "blocking\n");
332 /* Block waiting for signals. */
333 sigsuspend (&wake_mask);
339 sigprocmask (SIG_SETMASK, &org_mask, NULL);
344 ret = waitpid (pid, status, flags);
345 while (ret == -1 && errno == EINTR);
350 fprintf (stderr, "my_waitpid (%d, 0x%x): status(%x), %d\n",
351 pid, flags, status ? *status : -1, ret);
357 /* Handle a GNU/Linux extended wait response. If we see a clone
358 event, we need to add the new LWP to our list (and not report the
359 trap to higher layers). */
362 handle_extended_wait (struct lwp_info *event_child, int wstat)
364 int event = wstat >> 16;
365 struct lwp_info *new_lwp;
367 if (event == PTRACE_EVENT_CLONE)
370 unsigned long new_pid;
371 int ret, status = W_STOPCODE (SIGSTOP);
373 ptrace (PTRACE_GETEVENTMSG, lwpid_of (event_child), 0, &new_pid);
375 /* If we haven't already seen the new PID stop, wait for it now. */
376 if (! pull_pid_from_list (&stopped_pids, new_pid))
378 /* The new child has a pending SIGSTOP. We can't affect it until it
379 hits the SIGSTOP, but we're already attached. */
381 ret = my_waitpid (new_pid, &status, __WALL);
384 perror_with_name ("waiting for new child");
385 else if (ret != new_pid)
386 warning ("wait returned unexpected PID %d", ret);
387 else if (!WIFSTOPPED (status))
388 warning ("wait returned unexpected status 0x%x", status);
391 linux_enable_event_reporting (new_pid);
393 ptid = ptid_build (pid_of (event_child), new_pid, 0);
394 new_lwp = (struct lwp_info *) add_lwp (ptid);
395 add_thread (ptid, new_lwp);
397 /* Either we're going to immediately resume the new thread
398 or leave it stopped. linux_resume_one_lwp is a nop if it
399 thinks the thread is currently running, so set this first
400 before calling linux_resume_one_lwp. */
401 new_lwp->stopped = 1;
403 /* Normally we will get the pending SIGSTOP. But in some cases
404 we might get another signal delivered to the group first.
405 If we do get another signal, be sure not to lose it. */
406 if (WSTOPSIG (status) == SIGSTOP)
408 if (stopping_threads)
409 new_lwp->stop_pc = get_stop_pc (new_lwp);
411 linux_resume_one_lwp (new_lwp, 0, 0, NULL);
415 new_lwp->stop_expected = 1;
417 if (stopping_threads)
419 new_lwp->stop_pc = get_stop_pc (new_lwp);
420 new_lwp->status_pending_p = 1;
421 new_lwp->status_pending = status;
424 /* Pass the signal on. This is what GDB does - except
425 shouldn't we really report it instead? */
426 linux_resume_one_lwp (new_lwp, 0, WSTOPSIG (status), NULL);
429 /* Always resume the current thread. If we are stopping
430 threads, it will have a pending SIGSTOP; we may as well
432 linux_resume_one_lwp (event_child, event_child->stepping, 0, NULL);
436 /* Return the PC as read from the regcache of LWP, without any
440 get_pc (struct lwp_info *lwp)
442 struct thread_info *saved_inferior;
443 struct regcache *regcache;
446 if (the_low_target.get_pc == NULL)
449 saved_inferior = current_inferior;
450 current_inferior = get_lwp_thread (lwp);
452 regcache = get_thread_regcache (current_inferior, 1);
453 pc = (*the_low_target.get_pc) (regcache);
456 fprintf (stderr, "pc is 0x%lx\n", (long) pc);
458 current_inferior = saved_inferior;
462 /* This function should only be called if LWP got a SIGTRAP.
463 The SIGTRAP could mean several things.
465 On i386, where decr_pc_after_break is non-zero:
466 If we were single-stepping this process using PTRACE_SINGLESTEP,
467 we will get only the one SIGTRAP (even if the instruction we
468 stepped over was a breakpoint). The value of $eip will be the
470 If we continue the process using PTRACE_CONT, we will get a
471 SIGTRAP when we hit a breakpoint. The value of $eip will be
472 the instruction after the breakpoint (i.e. needs to be
473 decremented). If we report the SIGTRAP to GDB, we must also
474 report the undecremented PC. If we cancel the SIGTRAP, we
475 must resume at the decremented PC.
477 (Presumably, not yet tested) On a non-decr_pc_after_break machine
478 with hardware or kernel single-step:
479 If we single-step over a breakpoint instruction, our PC will
480 point at the following instruction. If we continue and hit a
481 breakpoint instruction, our PC will point at the breakpoint
485 get_stop_pc (struct lwp_info *lwp)
489 if (the_low_target.get_pc == NULL)
492 stop_pc = get_pc (lwp);
494 if (WSTOPSIG (lwp->last_status) == SIGTRAP
496 && !lwp->stopped_by_watchpoint
497 && lwp->last_status >> 16 == 0)
498 stop_pc -= the_low_target.decr_pc_after_break;
501 fprintf (stderr, "stop pc is 0x%lx\n", (long) stop_pc);
507 add_lwp (ptid_t ptid)
509 struct lwp_info *lwp;
511 lwp = (struct lwp_info *) xmalloc (sizeof (*lwp));
512 memset (lwp, 0, sizeof (*lwp));
516 if (the_low_target.new_thread != NULL)
517 lwp->arch_private = the_low_target.new_thread ();
519 add_inferior_to_list (&all_lwps, &lwp->head);
524 /* Start an inferior process and returns its pid.
525 ALLARGS is a vector of program-name and args. */
528 linux_create_inferior (char *program, char **allargs)
530 #ifdef HAVE_PERSONALITY
531 int personality_orig = 0, personality_set = 0;
533 struct lwp_info *new_lwp;
537 #ifdef HAVE_PERSONALITY
538 if (disable_randomization)
541 personality_orig = personality (0xffffffff);
542 if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE))
545 personality (personality_orig | ADDR_NO_RANDOMIZE);
547 if (errno != 0 || (personality_set
548 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE)))
549 warning ("Error disabling address space randomization: %s",
554 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
560 perror_with_name ("fork");
564 ptrace (PTRACE_TRACEME, 0, 0, 0);
566 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
567 signal (__SIGRTMIN + 1, SIG_DFL);
572 execv (program, allargs);
574 execvp (program, allargs);
576 fprintf (stderr, "Cannot exec %s: %s.\n", program,
582 #ifdef HAVE_PERSONALITY
586 personality (personality_orig);
588 warning ("Error restoring address space randomization: %s",
593 linux_add_process (pid, 0);
595 ptid = ptid_build (pid, pid, 0);
596 new_lwp = add_lwp (ptid);
597 add_thread (ptid, new_lwp);
598 new_lwp->must_set_ptrace_flags = 1;
603 /* Attach to an inferior process. */
606 linux_attach_lwp_1 (unsigned long lwpid, int initial)
609 struct lwp_info *new_lwp;
611 if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) != 0)
615 /* If we fail to attach to an LWP, just warn. */
616 fprintf (stderr, "Cannot attach to lwp %ld: %s (%d)\n", lwpid,
617 strerror (errno), errno);
622 /* If we fail to attach to a process, report an error. */
623 error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid,
624 strerror (errno), errno);
628 /* If lwp is the tgid, we handle adding existing threads later.
629 Otherwise we just add lwp without bothering about any other
631 ptid = ptid_build (lwpid, lwpid, 0);
634 /* Note that extracting the pid from the current inferior is
635 safe, since we're always called in the context of the same
636 process as this new thread. */
637 int pid = pid_of (get_thread_lwp (current_inferior));
638 ptid = ptid_build (pid, lwpid, 0);
641 new_lwp = (struct lwp_info *) add_lwp (ptid);
642 add_thread (ptid, new_lwp);
644 /* We need to wait for SIGSTOP before being able to make the next
645 ptrace call on this LWP. */
646 new_lwp->must_set_ptrace_flags = 1;
648 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
651 There are several cases to consider here:
653 1) gdbserver has already attached to the process and is being notified
654 of a new thread that is being created.
655 In this case we should ignore that SIGSTOP and resume the
656 process. This is handled below by setting stop_expected = 1,
657 and the fact that add_thread sets last_resume_kind ==
660 2) This is the first thread (the process thread), and we're attaching
661 to it via attach_inferior.
662 In this case we want the process thread to stop.
663 This is handled by having linux_attach set last_resume_kind ==
664 resume_stop after we return.
666 If the pid we are attaching to is also the tgid, we attach to and
667 stop all the existing threads. Otherwise, we attach to pid and
668 ignore any other threads in the same group as this pid.
670 3) GDB is connecting to gdbserver and is requesting an enumeration of all
672 In this case we want the thread to stop.
673 FIXME: This case is currently not properly handled.
674 We should wait for the SIGSTOP but don't. Things work apparently
675 because enough time passes between when we ptrace (ATTACH) and when
676 gdb makes the next ptrace call on the thread.
678 On the other hand, if we are currently trying to stop all threads, we
679 should treat the new thread as if we had sent it a SIGSTOP. This works
680 because we are guaranteed that the add_lwp call above added us to the
681 end of the list, and so the new thread has not yet reached
682 wait_for_sigstop (but will). */
683 new_lwp->stop_expected = 1;
687 linux_attach_lwp (unsigned long lwpid)
689 linux_attach_lwp_1 (lwpid, 0);
692 /* Attach to PID. If PID is the tgid, attach to it and all
696 linux_attach (unsigned long pid)
698 /* Attach to PID. We will check for other threads
700 linux_attach_lwp_1 (pid, 1);
701 linux_add_process (pid, 1);
705 struct thread_info *thread;
707 /* Don't ignore the initial SIGSTOP if we just attached to this
708 process. It will be collected by wait shortly. */
709 thread = find_thread_ptid (ptid_build (pid, pid, 0));
710 thread->last_resume_kind = resume_stop;
713 if (linux_proc_get_tgid (pid) == pid)
718 sprintf (pathname, "/proc/%ld/task", pid);
720 dir = opendir (pathname);
724 fprintf (stderr, "Could not open /proc/%ld/task.\n", pid);
729 /* At this point we attached to the tgid. Scan the task for
732 int new_threads_found;
736 while (iterations < 2)
738 new_threads_found = 0;
739 /* Add all the other threads. While we go through the
740 threads, new threads may be spawned. Cycle through
741 the list of threads until we have done two iterations without
742 finding new threads. */
743 while ((dp = readdir (dir)) != NULL)
746 lwp = strtoul (dp->d_name, NULL, 10);
748 /* Is this a new thread? */
750 && find_thread_ptid (ptid_build (pid, lwp, 0)) == NULL)
752 linux_attach_lwp_1 (lwp, 0);
757 Found and attached to new lwp %ld\n", lwp);
761 if (!new_threads_found)
782 second_thread_of_pid_p (struct inferior_list_entry *entry, void *args)
784 struct counter *counter = args;
786 if (ptid_get_pid (entry->id) == counter->pid)
788 if (++counter->count > 1)
796 last_thread_of_process_p (struct thread_info *thread)
798 ptid_t ptid = ((struct inferior_list_entry *)thread)->id;
799 int pid = ptid_get_pid (ptid);
800 struct counter counter = { pid , 0 };
802 return (find_inferior (&all_threads,
803 second_thread_of_pid_p, &counter) == NULL);
806 /* Kill the inferior lwp. */
809 linux_kill_one_lwp (struct inferior_list_entry *entry, void *args)
811 struct thread_info *thread = (struct thread_info *) entry;
812 struct lwp_info *lwp = get_thread_lwp (thread);
814 int pid = * (int *) args;
816 if (ptid_get_pid (entry->id) != pid)
819 /* We avoid killing the first thread here, because of a Linux kernel (at
820 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
821 the children get a chance to be reaped, it will remain a zombie
824 if (lwpid_of (lwp) == pid)
827 fprintf (stderr, "lkop: is last of process %s\n",
828 target_pid_to_str (entry->id));
834 ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0);
836 /* Make sure it died. The loop is most likely unnecessary. */
837 pid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
838 } while (pid > 0 && WIFSTOPPED (wstat));
846 struct process_info *process;
847 struct lwp_info *lwp;
851 process = find_process_pid (pid);
855 /* If we're killing a running inferior, make sure it is stopped
856 first, as PTRACE_KILL will not work otherwise. */
857 stop_all_lwps (0, NULL);
859 find_inferior (&all_threads, linux_kill_one_lwp, &pid);
861 /* See the comment in linux_kill_one_lwp. We did not kill the first
862 thread in the list, so do so now. */
863 lwp = find_lwp_pid (pid_to_ptid (pid));
868 fprintf (stderr, "lk_1: cannot find lwp %ld, for pid: %d\n",
869 lwpid_of (lwp), pid);
874 fprintf (stderr, "lk_1: killing lwp %ld, for pid: %d\n",
875 lwpid_of (lwp), pid);
879 ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0);
881 /* Make sure it died. The loop is most likely unnecessary. */
882 lwpid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
883 } while (lwpid > 0 && WIFSTOPPED (wstat));
886 the_target->mourn (process);
888 /* Since we presently can only stop all lwps of all processes, we
889 need to unstop lwps of other processes. */
890 unstop_all_lwps (0, NULL);
895 linux_detach_one_lwp (struct inferior_list_entry *entry, void *args)
897 struct thread_info *thread = (struct thread_info *) entry;
898 struct lwp_info *lwp = get_thread_lwp (thread);
899 int pid = * (int *) args;
901 if (ptid_get_pid (entry->id) != pid)
904 /* If this process is stopped but is expecting a SIGSTOP, then make
905 sure we take care of that now. This isn't absolutely guaranteed
906 to collect the SIGSTOP, but is fairly likely to. */
907 if (lwp->stop_expected)
910 /* Clear stop_expected, so that the SIGSTOP will be reported. */
911 lwp->stop_expected = 0;
912 linux_resume_one_lwp (lwp, 0, 0, NULL);
913 linux_wait_for_event (lwp->head.id, &wstat, __WALL);
916 /* Flush any pending changes to the process's registers. */
917 regcache_invalidate_one ((struct inferior_list_entry *)
918 get_lwp_thread (lwp));
920 /* Finally, let it resume. */
921 if (the_low_target.prepare_to_resume != NULL)
922 the_low_target.prepare_to_resume (lwp);
923 ptrace (PTRACE_DETACH, lwpid_of (lwp), 0, 0);
930 linux_detach (int pid)
932 struct process_info *process;
934 process = find_process_pid (pid);
938 /* Stop all threads before detaching. First, ptrace requires that
939 the thread is stopped to sucessfully detach. Second, thread_db
940 may need to uninstall thread event breakpoints from memory, which
941 only works with a stopped process anyway. */
942 stop_all_lwps (0, NULL);
945 thread_db_detach (process);
948 /* Stabilize threads (move out of jump pads). */
949 stabilize_threads ();
951 find_inferior (&all_threads, linux_detach_one_lwp, &pid);
953 the_target->mourn (process);
955 /* Since we presently can only stop all lwps of all processes, we
956 need to unstop lwps of other processes. */
957 unstop_all_lwps (0, NULL);
961 /* Remove all LWPs that belong to process PROC from the lwp list. */
964 delete_lwp_callback (struct inferior_list_entry *entry, void *proc)
966 struct lwp_info *lwp = (struct lwp_info *) entry;
967 struct process_info *process = proc;
969 if (pid_of (lwp) == pid_of (process))
976 linux_mourn (struct process_info *process)
978 struct process_info_private *priv;
981 thread_db_mourn (process);
984 find_inferior (&all_lwps, delete_lwp_callback, process);
986 /* Freeing all private data. */
987 priv = process->private;
988 free (priv->arch_private);
990 process->private = NULL;
992 remove_process (process);
1001 ret = my_waitpid (pid, &status, 0);
1002 if (WIFEXITED (status) || WIFSIGNALED (status))
1004 } while (ret != -1 || errno != ECHILD);
1007 /* Return nonzero if the given thread is still alive. */
1009 linux_thread_alive (ptid_t ptid)
1011 struct lwp_info *lwp = find_lwp_pid (ptid);
1013 /* We assume we always know if a thread exits. If a whole process
1014 exited but we still haven't been able to report it to GDB, we'll
1015 hold on to the last lwp of the dead process. */
1022 /* Return 1 if this lwp has an interesting status pending. */
1024 status_pending_p_callback (struct inferior_list_entry *entry, void *arg)
1026 struct lwp_info *lwp = (struct lwp_info *) entry;
1027 ptid_t ptid = * (ptid_t *) arg;
1028 struct thread_info *thread;
1030 /* Check if we're only interested in events from a specific process
1032 if (!ptid_equal (minus_one_ptid, ptid)
1033 && ptid_get_pid (ptid) != ptid_get_pid (lwp->head.id))
1036 thread = get_lwp_thread (lwp);
1038 /* If we got a `vCont;t', but we haven't reported a stop yet, do
1039 report any status pending the LWP may have. */
1040 if (thread->last_resume_kind == resume_stop
1041 && thread->last_status.kind != TARGET_WAITKIND_IGNORE)
1044 return lwp->status_pending_p;
1048 same_lwp (struct inferior_list_entry *entry, void *data)
1050 ptid_t ptid = *(ptid_t *) data;
1053 if (ptid_get_lwp (ptid) != 0)
1054 lwp = ptid_get_lwp (ptid);
1056 lwp = ptid_get_pid (ptid);
1058 if (ptid_get_lwp (entry->id) == lwp)
1065 find_lwp_pid (ptid_t ptid)
1067 return (struct lwp_info*) find_inferior (&all_lwps, same_lwp, &ptid);
1070 static struct lwp_info *
1071 linux_wait_for_lwp (ptid_t ptid, int *wstatp, int options)
1074 int to_wait_for = -1;
1075 struct lwp_info *child = NULL;
1078 fprintf (stderr, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid));
1080 if (ptid_equal (ptid, minus_one_ptid))
1081 to_wait_for = -1; /* any child */
1083 to_wait_for = ptid_get_lwp (ptid); /* this lwp only */
1089 ret = my_waitpid (to_wait_for, wstatp, options);
1090 if (ret == 0 || (ret == -1 && errno == ECHILD && (options & WNOHANG)))
1093 perror_with_name ("waitpid");
1096 && (!WIFSTOPPED (*wstatp)
1097 || (WSTOPSIG (*wstatp) != 32
1098 && WSTOPSIG (*wstatp) != 33)))
1099 fprintf (stderr, "Got an event from %d (%x)\n", ret, *wstatp);
1101 child = find_lwp_pid (pid_to_ptid (ret));
1103 /* If we didn't find a process, one of two things presumably happened:
1104 - A process we started and then detached from has exited. Ignore it.
1105 - A process we are controlling has forked and the new child's stop
1106 was reported to us by the kernel. Save its PID. */
1107 if (child == NULL && WIFSTOPPED (*wstatp))
1109 add_pid_to_list (&stopped_pids, ret);
1112 else if (child == NULL)
1117 child->last_status = *wstatp;
1119 /* Architecture-specific setup after inferior is running.
1120 This needs to happen after we have attached to the inferior
1121 and it is stopped for the first time, but before we access
1122 any inferior registers. */
1125 the_low_target.arch_setup ();
1126 #ifdef HAVE_LINUX_REGSETS
1127 memset (disabled_regsets, 0, num_regsets);
1132 /* Fetch the possibly triggered data watchpoint info and store it in
1135 On some archs, like x86, that use debug registers to set
1136 watchpoints, it's possible that the way to know which watched
1137 address trapped, is to check the register that is used to select
1138 which address to watch. Problem is, between setting the
1139 watchpoint and reading back which data address trapped, the user
1140 may change the set of watchpoints, and, as a consequence, GDB
1141 changes the debug registers in the inferior. To avoid reading
1142 back a stale stopped-data-address when that happens, we cache in
1143 LP the fact that a watchpoint trapped, and the corresponding data
1144 address, as soon as we see CHILD stop with a SIGTRAP. If GDB
1145 changes the debug registers meanwhile, we have the cached data we
1148 if (WIFSTOPPED (*wstatp) && WSTOPSIG (*wstatp) == SIGTRAP)
1150 if (the_low_target.stopped_by_watchpoint == NULL)
1152 child->stopped_by_watchpoint = 0;
1156 struct thread_info *saved_inferior;
1158 saved_inferior = current_inferior;
1159 current_inferior = get_lwp_thread (child);
1161 child->stopped_by_watchpoint
1162 = the_low_target.stopped_by_watchpoint ();
1164 if (child->stopped_by_watchpoint)
1166 if (the_low_target.stopped_data_address != NULL)
1167 child->stopped_data_address
1168 = the_low_target.stopped_data_address ();
1170 child->stopped_data_address = 0;
1173 current_inferior = saved_inferior;
1177 /* Store the STOP_PC, with adjustment applied. This depends on the
1178 architecture being defined already (so that CHILD has a valid
1179 regcache), and on LAST_STATUS being set (to check for SIGTRAP or
1181 if (WIFSTOPPED (*wstatp))
1182 child->stop_pc = get_stop_pc (child);
1185 && WIFSTOPPED (*wstatp)
1186 && the_low_target.get_pc != NULL)
1188 struct thread_info *saved_inferior = current_inferior;
1189 struct regcache *regcache;
1192 current_inferior = get_lwp_thread (child);
1193 regcache = get_thread_regcache (current_inferior, 1);
1194 pc = (*the_low_target.get_pc) (regcache);
1195 fprintf (stderr, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc);
1196 current_inferior = saved_inferior;
1202 /* This function should only be called if the LWP got a SIGTRAP.
1204 Handle any tracepoint steps or hits. Return true if a tracepoint
1205 event was handled, 0 otherwise. */
1208 handle_tracepoints (struct lwp_info *lwp)
1210 struct thread_info *tinfo = get_lwp_thread (lwp);
1211 int tpoint_related_event = 0;
1213 /* If this tracepoint hit causes a tracing stop, we'll immediately
1214 uninsert tracepoints. To do this, we temporarily pause all
1215 threads, unpatch away, and then unpause threads. We need to make
1216 sure the unpausing doesn't resume LWP too. */
1219 /* And we need to be sure that any all-threads-stopping doesn't try
1220 to move threads out of the jump pads, as it could deadlock the
1221 inferior (LWP could be in the jump pad, maybe even holding the
1224 /* Do any necessary step collect actions. */
1225 tpoint_related_event |= tracepoint_finished_step (tinfo, lwp->stop_pc);
1227 tpoint_related_event |= handle_tracepoint_bkpts (tinfo, lwp->stop_pc);
1229 /* See if we just hit a tracepoint and do its main collect
1231 tpoint_related_event |= tracepoint_was_hit (tinfo, lwp->stop_pc);
1235 gdb_assert (lwp->suspended == 0);
1236 gdb_assert (!stabilizing_threads || lwp->collecting_fast_tracepoint);
1238 if (tpoint_related_event)
1241 fprintf (stderr, "got a tracepoint event\n");
1248 /* Convenience wrapper. Returns true if LWP is presently collecting a
1252 linux_fast_tracepoint_collecting (struct lwp_info *lwp,
1253 struct fast_tpoint_collect_status *status)
1255 CORE_ADDR thread_area;
1257 if (the_low_target.get_thread_area == NULL)
1260 /* Get the thread area address. This is used to recognize which
1261 thread is which when tracing with the in-process agent library.
1262 We don't read anything from the address, and treat it as opaque;
1263 it's the address itself that we assume is unique per-thread. */
1264 if ((*the_low_target.get_thread_area) (lwpid_of (lwp), &thread_area) == -1)
1267 return fast_tracepoint_collecting (thread_area, lwp->stop_pc, status);
1270 /* The reason we resume in the caller, is because we want to be able
1271 to pass lwp->status_pending as WSTAT, and we need to clear
1272 status_pending_p before resuming, otherwise, linux_resume_one_lwp
1273 refuses to resume. */
1276 maybe_move_out_of_jump_pad (struct lwp_info *lwp, int *wstat)
1278 struct thread_info *saved_inferior;
1280 saved_inferior = current_inferior;
1281 current_inferior = get_lwp_thread (lwp);
1284 || (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) != SIGTRAP))
1285 && supports_fast_tracepoints ()
1286 && in_process_agent_loaded ())
1288 struct fast_tpoint_collect_status status;
1293 Checking whether LWP %ld needs to move out of the jump pad.\n",
1296 r = linux_fast_tracepoint_collecting (lwp, &status);
1299 || (WSTOPSIG (*wstat) != SIGILL
1300 && WSTOPSIG (*wstat) != SIGFPE
1301 && WSTOPSIG (*wstat) != SIGSEGV
1302 && WSTOPSIG (*wstat) != SIGBUS))
1304 lwp->collecting_fast_tracepoint = r;
1308 if (r == 1 && lwp->exit_jump_pad_bkpt == NULL)
1310 /* Haven't executed the original instruction yet.
1311 Set breakpoint there, and wait till it's hit,
1312 then single-step until exiting the jump pad. */
1313 lwp->exit_jump_pad_bkpt
1314 = set_breakpoint_at (status.adjusted_insn_addr, NULL);
1319 Checking whether LWP %ld needs to move out of the jump pad...it does\n",
1321 current_inferior = saved_inferior;
1328 /* If we get a synchronous signal while collecting, *and*
1329 while executing the (relocated) original instruction,
1330 reset the PC to point at the tpoint address, before
1331 reporting to GDB. Otherwise, it's an IPA lib bug: just
1332 report the signal to GDB, and pray for the best. */
1334 lwp->collecting_fast_tracepoint = 0;
1337 && (status.adjusted_insn_addr <= lwp->stop_pc
1338 && lwp->stop_pc < status.adjusted_insn_addr_end))
1341 struct regcache *regcache;
1343 /* The si_addr on a few signals references the address
1344 of the faulting instruction. Adjust that as
1346 if ((WSTOPSIG (*wstat) == SIGILL
1347 || WSTOPSIG (*wstat) == SIGFPE
1348 || WSTOPSIG (*wstat) == SIGBUS
1349 || WSTOPSIG (*wstat) == SIGSEGV)
1350 && ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &info) == 0
1351 /* Final check just to make sure we don't clobber
1352 the siginfo of non-kernel-sent signals. */
1353 && (uintptr_t) info.si_addr == lwp->stop_pc)
1355 info.si_addr = (void *) (uintptr_t) status.tpoint_addr;
1356 ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &info);
1359 regcache = get_thread_regcache (get_lwp_thread (lwp), 1);
1360 (*the_low_target.set_pc) (regcache, status.tpoint_addr);
1361 lwp->stop_pc = status.tpoint_addr;
1363 /* Cancel any fast tracepoint lock this thread was
1365 force_unlock_trace_buffer ();
1368 if (lwp->exit_jump_pad_bkpt != NULL)
1372 "Cancelling fast exit-jump-pad: removing bkpt. "
1373 "stopping all threads momentarily.\n");
1375 stop_all_lwps (1, lwp);
1376 cancel_breakpoints ();
1378 delete_breakpoint (lwp->exit_jump_pad_bkpt);
1379 lwp->exit_jump_pad_bkpt = NULL;
1381 unstop_all_lwps (1, lwp);
1383 gdb_assert (lwp->suspended >= 0);
1390 Checking whether LWP %ld needs to move out of the jump pad...no\n",
1393 current_inferior = saved_inferior;
1397 /* Enqueue one signal in the "signals to report later when out of the
1401 enqueue_one_deferred_signal (struct lwp_info *lwp, int *wstat)
1403 struct pending_signals *p_sig;
1407 Deferring signal %d for LWP %ld.\n", WSTOPSIG (*wstat), lwpid_of (lwp));
1411 struct pending_signals *sig;
1413 for (sig = lwp->pending_signals_to_report;
1417 " Already queued %d\n",
1420 fprintf (stderr, " (no more currently queued signals)\n");
1423 /* Don't enqueue non-RT signals if they are already in the deferred
1424 queue. (SIGSTOP being the easiest signal to see ending up here
1426 if (WSTOPSIG (*wstat) < __SIGRTMIN)
1428 struct pending_signals *sig;
1430 for (sig = lwp->pending_signals_to_report;
1434 if (sig->signal == WSTOPSIG (*wstat))
1438 "Not requeuing already queued non-RT signal %d"
1447 p_sig = xmalloc (sizeof (*p_sig));
1448 p_sig->prev = lwp->pending_signals_to_report;
1449 p_sig->signal = WSTOPSIG (*wstat);
1450 memset (&p_sig->info, 0, sizeof (siginfo_t));
1451 ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info);
1453 lwp->pending_signals_to_report = p_sig;
1456 /* Dequeue one signal from the "signals to report later when out of
1457 the jump pad" list. */
1460 dequeue_one_deferred_signal (struct lwp_info *lwp, int *wstat)
1462 if (lwp->pending_signals_to_report != NULL)
1464 struct pending_signals **p_sig;
1466 p_sig = &lwp->pending_signals_to_report;
1467 while ((*p_sig)->prev != NULL)
1468 p_sig = &(*p_sig)->prev;
1470 *wstat = W_STOPCODE ((*p_sig)->signal);
1471 if ((*p_sig)->info.si_signo != 0)
1472 ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &(*p_sig)->info);
1477 fprintf (stderr, "Reporting deferred signal %d for LWP %ld.\n",
1478 WSTOPSIG (*wstat), lwpid_of (lwp));
1482 struct pending_signals *sig;
1484 for (sig = lwp->pending_signals_to_report;
1488 " Still queued %d\n",
1491 fprintf (stderr, " (no more queued signals)\n");
1500 /* Arrange for a breakpoint to be hit again later. We don't keep the
1501 SIGTRAP status and don't forward the SIGTRAP signal to the LWP. We
1502 will handle the current event, eventually we will resume this LWP,
1503 and this breakpoint will trap again. */
1506 cancel_breakpoint (struct lwp_info *lwp)
1508 struct thread_info *saved_inferior;
1510 /* There's nothing to do if we don't support breakpoints. */
1511 if (!supports_breakpoints ())
1514 /* breakpoint_at reads from current inferior. */
1515 saved_inferior = current_inferior;
1516 current_inferior = get_lwp_thread (lwp);
1518 if ((*the_low_target.breakpoint_at) (lwp->stop_pc))
1522 "CB: Push back breakpoint for %s\n",
1523 target_pid_to_str (ptid_of (lwp)));
1525 /* Back up the PC if necessary. */
1526 if (the_low_target.decr_pc_after_break)
1528 struct regcache *regcache
1529 = get_thread_regcache (current_inferior, 1);
1530 (*the_low_target.set_pc) (regcache, lwp->stop_pc);
1533 current_inferior = saved_inferior;
1540 "CB: No breakpoint found at %s for [%s]\n",
1541 paddress (lwp->stop_pc),
1542 target_pid_to_str (ptid_of (lwp)));
1545 current_inferior = saved_inferior;
1549 /* When the event-loop is doing a step-over, this points at the thread
1551 ptid_t step_over_bkpt;
1553 /* Wait for an event from child PID. If PID is -1, wait for any
1554 child. Store the stop status through the status pointer WSTAT.
1555 OPTIONS is passed to the waitpid call. Return 0 if no child stop
1556 event was found and OPTIONS contains WNOHANG. Return the PID of
1557 the stopped child otherwise. */
1560 linux_wait_for_event_1 (ptid_t ptid, int *wstat, int options)
1562 struct lwp_info *event_child, *requested_child;
1565 requested_child = NULL;
1567 /* Check for a lwp with a pending status. */
1569 if (ptid_equal (ptid, minus_one_ptid)
1570 || ptid_equal (pid_to_ptid (ptid_get_pid (ptid)), ptid))
1572 event_child = (struct lwp_info *)
1573 find_inferior (&all_lwps, status_pending_p_callback, &ptid);
1574 if (debug_threads && event_child)
1575 fprintf (stderr, "Got a pending child %ld\n", lwpid_of (event_child));
1579 requested_child = find_lwp_pid (ptid);
1581 if (!stopping_threads
1582 && requested_child->status_pending_p
1583 && requested_child->collecting_fast_tracepoint)
1585 enqueue_one_deferred_signal (requested_child,
1586 &requested_child->status_pending);
1587 requested_child->status_pending_p = 0;
1588 requested_child->status_pending = 0;
1589 linux_resume_one_lwp (requested_child, 0, 0, NULL);
1592 if (requested_child->suspended
1593 && requested_child->status_pending_p)
1594 fatal ("requesting an event out of a suspended child?");
1596 if (requested_child->status_pending_p)
1597 event_child = requested_child;
1600 if (event_child != NULL)
1603 fprintf (stderr, "Got an event from pending child %ld (%04x)\n",
1604 lwpid_of (event_child), event_child->status_pending);
1605 *wstat = event_child->status_pending;
1606 event_child->status_pending_p = 0;
1607 event_child->status_pending = 0;
1608 current_inferior = get_lwp_thread (event_child);
1609 return lwpid_of (event_child);
1612 /* We only enter this loop if no process has a pending wait status. Thus
1613 any action taken in response to a wait status inside this loop is
1614 responding as soon as we detect the status, not after any pending
1618 event_child = linux_wait_for_lwp (ptid, wstat, options);
1620 if ((options & WNOHANG) && event_child == NULL)
1623 fprintf (stderr, "WNOHANG set, no event found\n");
1627 if (event_child == NULL)
1628 error ("event from unknown child");
1630 current_inferior = get_lwp_thread (event_child);
1632 /* Check for thread exit. */
1633 if (! WIFSTOPPED (*wstat))
1636 fprintf (stderr, "LWP %ld exiting\n", lwpid_of (event_child));
1638 /* If the last thread is exiting, just return. */
1639 if (last_thread_of_process_p (current_inferior))
1642 fprintf (stderr, "LWP %ld is last lwp of process\n",
1643 lwpid_of (event_child));
1644 return lwpid_of (event_child);
1649 current_inferior = (struct thread_info *) all_threads.head;
1651 fprintf (stderr, "Current inferior is now %ld\n",
1652 lwpid_of (get_thread_lwp (current_inferior)));
1656 current_inferior = NULL;
1658 fprintf (stderr, "Current inferior is now <NULL>\n");
1661 /* If we were waiting for this particular child to do something...
1662 well, it did something. */
1663 if (requested_child != NULL)
1665 int lwpid = lwpid_of (event_child);
1667 /* Cancel the step-over operation --- the thread that
1668 started it is gone. */
1669 if (finish_step_over (event_child))
1670 unstop_all_lwps (1, event_child);
1671 delete_lwp (event_child);
1675 delete_lwp (event_child);
1677 /* Wait for a more interesting event. */
1681 if (event_child->must_set_ptrace_flags)
1683 linux_enable_event_reporting (lwpid_of (event_child));
1684 event_child->must_set_ptrace_flags = 0;
1687 if (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) == SIGTRAP
1688 && *wstat >> 16 != 0)
1690 handle_extended_wait (event_child, *wstat);
1694 if (WIFSTOPPED (*wstat)
1695 && WSTOPSIG (*wstat) == SIGSTOP
1696 && event_child->stop_expected)
1701 fprintf (stderr, "Expected stop.\n");
1702 event_child->stop_expected = 0;
1704 should_stop = (current_inferior->last_resume_kind == resume_stop
1705 || stopping_threads);
1709 linux_resume_one_lwp (event_child,
1710 event_child->stepping, 0, NULL);
1715 return lwpid_of (event_child);
1723 linux_wait_for_event (ptid_t ptid, int *wstat, int options)
1727 if (ptid_is_pid (ptid))
1729 /* A request to wait for a specific tgid. This is not possible
1730 with waitpid, so instead, we wait for any child, and leave
1731 children we're not interested in right now with a pending
1732 status to report later. */
1733 wait_ptid = minus_one_ptid;
1742 event_pid = linux_wait_for_event_1 (wait_ptid, wstat, options);
1745 && ptid_is_pid (ptid) && ptid_get_pid (ptid) != event_pid)
1747 struct lwp_info *event_child
1748 = find_lwp_pid (pid_to_ptid (event_pid));
1750 if (! WIFSTOPPED (*wstat))
1751 mark_lwp_dead (event_child, *wstat);
1754 event_child->status_pending_p = 1;
1755 event_child->status_pending = *wstat;
1764 /* Count the LWP's that have had events. */
1767 count_events_callback (struct inferior_list_entry *entry, void *data)
1769 struct lwp_info *lp = (struct lwp_info *) entry;
1770 struct thread_info *thread = get_lwp_thread (lp);
1773 gdb_assert (count != NULL);
1775 /* Count only resumed LWPs that have a SIGTRAP event pending that
1776 should be reported to GDB. */
1777 if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
1778 && thread->last_resume_kind != resume_stop
1779 && lp->status_pending_p
1780 && WIFSTOPPED (lp->status_pending)
1781 && WSTOPSIG (lp->status_pending) == SIGTRAP
1782 && !breakpoint_inserted_here (lp->stop_pc))
1788 /* Select the LWP (if any) that is currently being single-stepped. */
1791 select_singlestep_lwp_callback (struct inferior_list_entry *entry, void *data)
1793 struct lwp_info *lp = (struct lwp_info *) entry;
1794 struct thread_info *thread = get_lwp_thread (lp);
1796 if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
1797 && thread->last_resume_kind == resume_step
1798 && lp->status_pending_p)
1804 /* Select the Nth LWP that has had a SIGTRAP event that should be
1808 select_event_lwp_callback (struct inferior_list_entry *entry, void *data)
1810 struct lwp_info *lp = (struct lwp_info *) entry;
1811 struct thread_info *thread = get_lwp_thread (lp);
1812 int *selector = data;
1814 gdb_assert (selector != NULL);
1816 /* Select only resumed LWPs that have a SIGTRAP event pending. */
1817 if (thread->last_resume_kind != resume_stop
1818 && thread->last_status.kind == TARGET_WAITKIND_IGNORE
1819 && lp->status_pending_p
1820 && WIFSTOPPED (lp->status_pending)
1821 && WSTOPSIG (lp->status_pending) == SIGTRAP
1822 && !breakpoint_inserted_here (lp->stop_pc))
1823 if ((*selector)-- == 0)
1830 cancel_breakpoints_callback (struct inferior_list_entry *entry, void *data)
1832 struct lwp_info *lp = (struct lwp_info *) entry;
1833 struct thread_info *thread = get_lwp_thread (lp);
1834 struct lwp_info *event_lp = data;
1836 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
1840 /* If a LWP other than the LWP that we're reporting an event for has
1841 hit a GDB breakpoint (as opposed to some random trap signal),
1842 then just arrange for it to hit it again later. We don't keep
1843 the SIGTRAP status and don't forward the SIGTRAP signal to the
1844 LWP. We will handle the current event, eventually we will resume
1845 all LWPs, and this one will get its breakpoint trap again.
1847 If we do not do this, then we run the risk that the user will
1848 delete or disable the breakpoint, but the LWP will have already
1851 if (thread->last_resume_kind != resume_stop
1852 && thread->last_status.kind == TARGET_WAITKIND_IGNORE
1853 && lp->status_pending_p
1854 && WIFSTOPPED (lp->status_pending)
1855 && WSTOPSIG (lp->status_pending) == SIGTRAP
1857 && !lp->stopped_by_watchpoint
1858 && cancel_breakpoint (lp))
1859 /* Throw away the SIGTRAP. */
1860 lp->status_pending_p = 0;
1866 linux_cancel_breakpoints (void)
1868 find_inferior (&all_lwps, cancel_breakpoints_callback, NULL);
1871 /* Select one LWP out of those that have events pending. */
1874 select_event_lwp (struct lwp_info **orig_lp)
1877 int random_selector;
1878 struct lwp_info *event_lp;
1880 /* Give preference to any LWP that is being single-stepped. */
1882 = (struct lwp_info *) find_inferior (&all_lwps,
1883 select_singlestep_lwp_callback, NULL);
1884 if (event_lp != NULL)
1888 "SEL: Select single-step %s\n",
1889 target_pid_to_str (ptid_of (event_lp)));
1893 /* No single-stepping LWP. Select one at random, out of those
1894 which have had SIGTRAP events. */
1896 /* First see how many SIGTRAP events we have. */
1897 find_inferior (&all_lwps, count_events_callback, &num_events);
1899 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
1900 random_selector = (int)
1901 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
1903 if (debug_threads && num_events > 1)
1905 "SEL: Found %d SIGTRAP events, selecting #%d\n",
1906 num_events, random_selector);
1908 event_lp = (struct lwp_info *) find_inferior (&all_lwps,
1909 select_event_lwp_callback,
1913 if (event_lp != NULL)
1915 /* Switch the event LWP. */
1916 *orig_lp = event_lp;
1920 /* Decrement the suspend count of an LWP. */
1923 unsuspend_one_lwp (struct inferior_list_entry *entry, void *except)
1925 struct lwp_info *lwp = (struct lwp_info *) entry;
1927 /* Ignore EXCEPT. */
1933 gdb_assert (lwp->suspended >= 0);
1937 /* Decrement the suspend count of all LWPs, except EXCEPT, if non
1941 unsuspend_all_lwps (struct lwp_info *except)
1943 find_inferior (&all_lwps, unsuspend_one_lwp, except);
1946 static void move_out_of_jump_pad_callback (struct inferior_list_entry *entry);
1947 static int stuck_in_jump_pad_callback (struct inferior_list_entry *entry,
1949 static int lwp_running (struct inferior_list_entry *entry, void *data);
1950 static ptid_t linux_wait_1 (ptid_t ptid,
1951 struct target_waitstatus *ourstatus,
1952 int target_options);
1954 /* Stabilize threads (move out of jump pads).
1956 If a thread is midway collecting a fast tracepoint, we need to
1957 finish the collection and move it out of the jump pad before
1958 reporting the signal.
1960 This avoids recursion while collecting (when a signal arrives
1961 midway, and the signal handler itself collects), which would trash
1962 the trace buffer. In case the user set a breakpoint in a signal
1963 handler, this avoids the backtrace showing the jump pad, etc..
1964 Most importantly, there are certain things we can't do safely if
1965 threads are stopped in a jump pad (or in its callee's). For
1968 - starting a new trace run. A thread still collecting the
1969 previous run, could trash the trace buffer when resumed. The trace
1970 buffer control structures would have been reset but the thread had
1971 no way to tell. The thread could even midway memcpy'ing to the
1972 buffer, which would mean that when resumed, it would clobber the
1973 trace buffer that had been set for a new run.
1975 - we can't rewrite/reuse the jump pads for new tracepoints
1976 safely. Say you do tstart while a thread is stopped midway while
1977 collecting. When the thread is later resumed, it finishes the
1978 collection, and returns to the jump pad, to execute the original
1979 instruction that was under the tracepoint jump at the time the
1980 older run had been started. If the jump pad had been rewritten
1981 since for something else in the new run, the thread would now
1982 execute the wrong / random instructions. */
1985 linux_stabilize_threads (void)
1987 struct thread_info *save_inferior;
1988 struct lwp_info *lwp_stuck;
1991 = (struct lwp_info *) find_inferior (&all_lwps,
1992 stuck_in_jump_pad_callback, NULL);
1993 if (lwp_stuck != NULL)
1996 fprintf (stderr, "can't stabilize, LWP %ld is stuck in jump pad\n",
1997 lwpid_of (lwp_stuck));
2001 save_inferior = current_inferior;
2003 stabilizing_threads = 1;
2006 for_each_inferior (&all_lwps, move_out_of_jump_pad_callback);
2008 /* Loop until all are stopped out of the jump pads. */
2009 while (find_inferior (&all_lwps, lwp_running, NULL) != NULL)
2011 struct target_waitstatus ourstatus;
2012 struct lwp_info *lwp;
2015 /* Note that we go through the full wait even loop. While
2016 moving threads out of jump pad, we need to be able to step
2017 over internal breakpoints and such. */
2018 linux_wait_1 (minus_one_ptid, &ourstatus, 0);
2020 if (ourstatus.kind == TARGET_WAITKIND_STOPPED)
2022 lwp = get_thread_lwp (current_inferior);
2027 if (ourstatus.value.sig != TARGET_SIGNAL_0
2028 || current_inferior->last_resume_kind == resume_stop)
2030 wstat = W_STOPCODE (target_signal_to_host (ourstatus.value.sig));
2031 enqueue_one_deferred_signal (lwp, &wstat);
2036 find_inferior (&all_lwps, unsuspend_one_lwp, NULL);
2038 stabilizing_threads = 0;
2040 current_inferior = save_inferior;
2045 = (struct lwp_info *) find_inferior (&all_lwps,
2046 stuck_in_jump_pad_callback, NULL);
2047 if (lwp_stuck != NULL)
2048 fprintf (stderr, "couldn't stabilize, LWP %ld got stuck in jump pad\n",
2049 lwpid_of (lwp_stuck));
2053 /* Wait for process, returns status. */
2056 linux_wait_1 (ptid_t ptid,
2057 struct target_waitstatus *ourstatus, int target_options)
2060 struct lwp_info *event_child;
2063 int step_over_finished;
2064 int bp_explains_trap;
2065 int maybe_internal_trap;
2069 /* Translate generic target options into linux options. */
2071 if (target_options & TARGET_WNOHANG)
2075 bp_explains_trap = 0;
2077 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2079 /* If we were only supposed to resume one thread, only wait for
2080 that thread - if it's still alive. If it died, however - which
2081 can happen if we're coming from the thread death case below -
2082 then we need to make sure we restart the other threads. We could
2083 pick a thread at random or restart all; restarting all is less
2086 && !ptid_equal (cont_thread, null_ptid)
2087 && !ptid_equal (cont_thread, minus_one_ptid))
2089 struct thread_info *thread;
2091 thread = (struct thread_info *) find_inferior_id (&all_threads,
2094 /* No stepping, no signal - unless one is pending already, of course. */
2097 struct thread_resume resume_info;
2098 resume_info.thread = minus_one_ptid;
2099 resume_info.kind = resume_continue;
2100 resume_info.sig = 0;
2101 linux_resume (&resume_info, 1);
2107 if (ptid_equal (step_over_bkpt, null_ptid))
2108 pid = linux_wait_for_event (ptid, &w, options);
2112 fprintf (stderr, "step_over_bkpt set [%s], doing a blocking wait\n",
2113 target_pid_to_str (step_over_bkpt));
2114 pid = linux_wait_for_event (step_over_bkpt, &w, options & ~WNOHANG);
2117 if (pid == 0) /* only if TARGET_WNOHANG */
2120 event_child = get_thread_lwp (current_inferior);
2122 /* If we are waiting for a particular child, and it exited,
2123 linux_wait_for_event will return its exit status. Similarly if
2124 the last child exited. If this is not the last child, however,
2125 do not report it as exited until there is a 'thread exited' response
2126 available in the remote protocol. Instead, just wait for another event.
2127 This should be safe, because if the thread crashed we will already
2128 have reported the termination signal to GDB; that should stop any
2129 in-progress stepping operations, etc.
2131 Report the exit status of the last thread to exit. This matches
2132 LinuxThreads' behavior. */
2134 if (last_thread_of_process_p (current_inferior))
2136 if (WIFEXITED (w) || WIFSIGNALED (w))
2140 ourstatus->kind = TARGET_WAITKIND_EXITED;
2141 ourstatus->value.integer = WEXITSTATUS (w);
2145 "\nChild exited with retcode = %x \n",
2150 ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
2151 ourstatus->value.sig = target_signal_from_host (WTERMSIG (w));
2155 "\nChild terminated with signal = %x \n",
2160 return ptid_of (event_child);
2165 if (!WIFSTOPPED (w))
2169 /* If this event was not handled before, and is not a SIGTRAP, we
2170 report it. SIGILL and SIGSEGV are also treated as traps in case
2171 a breakpoint is inserted at the current PC. If this target does
2172 not support internal breakpoints at all, we also report the
2173 SIGTRAP without further processing; it's of no concern to us. */
2175 = (supports_breakpoints ()
2176 && (WSTOPSIG (w) == SIGTRAP
2177 || ((WSTOPSIG (w) == SIGILL
2178 || WSTOPSIG (w) == SIGSEGV)
2179 && (*the_low_target.breakpoint_at) (event_child->stop_pc))));
2181 if (maybe_internal_trap)
2183 /* Handle anything that requires bookkeeping before deciding to
2184 report the event or continue waiting. */
2186 /* First check if we can explain the SIGTRAP with an internal
2187 breakpoint, or if we should possibly report the event to GDB.
2188 Do this before anything that may remove or insert a
2190 bp_explains_trap = breakpoint_inserted_here (event_child->stop_pc);
2192 /* We have a SIGTRAP, possibly a step-over dance has just
2193 finished. If so, tweak the state machine accordingly,
2194 reinsert breakpoints and delete any reinsert (software
2195 single-step) breakpoints. */
2196 step_over_finished = finish_step_over (event_child);
2198 /* Now invoke the callbacks of any internal breakpoints there. */
2199 check_breakpoints (event_child->stop_pc);
2201 /* Handle tracepoint data collecting. This may overflow the
2202 trace buffer, and cause a tracing stop, removing
2204 trace_event = handle_tracepoints (event_child);
2206 if (bp_explains_trap)
2208 /* If we stepped or ran into an internal breakpoint, we've
2209 already handled it. So next time we resume (from this
2210 PC), we should step over it. */
2212 fprintf (stderr, "Hit a gdbserver breakpoint.\n");
2214 if (breakpoint_here (event_child->stop_pc))
2215 event_child->need_step_over = 1;
2220 /* We have some other signal, possibly a step-over dance was in
2221 progress, and it should be cancelled too. */
2222 step_over_finished = finish_step_over (event_child);
2225 /* We have all the data we need. Either report the event to GDB, or
2226 resume threads and keep waiting for more. */
2228 /* If we're collecting a fast tracepoint, finish the collection and
2229 move out of the jump pad before delivering a signal. See
2230 linux_stabilize_threads. */
2233 && WSTOPSIG (w) != SIGTRAP
2234 && supports_fast_tracepoints ()
2235 && in_process_agent_loaded ())
2239 "Got signal %d for LWP %ld. Check if we need "
2240 "to defer or adjust it.\n",
2241 WSTOPSIG (w), lwpid_of (event_child));
2243 /* Allow debugging the jump pad itself. */
2244 if (current_inferior->last_resume_kind != resume_step
2245 && maybe_move_out_of_jump_pad (event_child, &w))
2247 enqueue_one_deferred_signal (event_child, &w);
2251 "Signal %d for LWP %ld deferred (in jump pad)\n",
2252 WSTOPSIG (w), lwpid_of (event_child));
2254 linux_resume_one_lwp (event_child, 0, 0, NULL);
2259 if (event_child->collecting_fast_tracepoint)
2263 LWP %ld was trying to move out of the jump pad (%d). \
2264 Check if we're already there.\n",
2265 lwpid_of (event_child),
2266 event_child->collecting_fast_tracepoint);
2270 event_child->collecting_fast_tracepoint
2271 = linux_fast_tracepoint_collecting (event_child, NULL);
2273 if (event_child->collecting_fast_tracepoint != 1)
2275 /* No longer need this breakpoint. */
2276 if (event_child->exit_jump_pad_bkpt != NULL)
2280 "No longer need exit-jump-pad bkpt; removing it."
2281 "stopping all threads momentarily.\n");
2283 /* Other running threads could hit this breakpoint.
2284 We don't handle moribund locations like GDB does,
2285 instead we always pause all threads when removing
2286 breakpoints, so that any step-over or
2287 decr_pc_after_break adjustment is always taken
2288 care of while the breakpoint is still
2290 stop_all_lwps (1, event_child);
2291 cancel_breakpoints ();
2293 delete_breakpoint (event_child->exit_jump_pad_bkpt);
2294 event_child->exit_jump_pad_bkpt = NULL;
2296 unstop_all_lwps (1, event_child);
2298 gdb_assert (event_child->suspended >= 0);
2302 if (event_child->collecting_fast_tracepoint == 0)
2306 "fast tracepoint finished "
2307 "collecting successfully.\n");
2309 /* We may have a deferred signal to report. */
2310 if (dequeue_one_deferred_signal (event_child, &w))
2313 fprintf (stderr, "dequeued one signal.\n");
2318 fprintf (stderr, "no deferred signals.\n");
2320 if (stabilizing_threads)
2322 ourstatus->kind = TARGET_WAITKIND_STOPPED;
2323 ourstatus->value.sig = TARGET_SIGNAL_0;
2324 return ptid_of (event_child);
2330 /* Check whether GDB would be interested in this event. */
2332 /* If GDB is not interested in this signal, don't stop other
2333 threads, and don't report it to GDB. Just resume the inferior
2334 right away. We do this for threading-related signals as well as
2335 any that GDB specifically requested we ignore. But never ignore
2336 SIGSTOP if we sent it ourselves, and do not ignore signals when
2337 stepping - they may require special handling to skip the signal
2339 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
2342 && current_inferior->last_resume_kind != resume_step
2344 #if defined (USE_THREAD_DB) && !defined (__ANDROID__)
2345 (current_process ()->private->thread_db != NULL
2346 && (WSTOPSIG (w) == __SIGRTMIN
2347 || WSTOPSIG (w) == __SIGRTMIN + 1))
2350 (pass_signals[target_signal_from_host (WSTOPSIG (w))]
2351 && !(WSTOPSIG (w) == SIGSTOP
2352 && current_inferior->last_resume_kind == resume_stop))))
2354 siginfo_t info, *info_p;
2357 fprintf (stderr, "Ignored signal %d for LWP %ld.\n",
2358 WSTOPSIG (w), lwpid_of (event_child));
2360 if (ptrace (PTRACE_GETSIGINFO, lwpid_of (event_child), 0, &info) == 0)
2364 linux_resume_one_lwp (event_child, event_child->stepping,
2365 WSTOPSIG (w), info_p);
2369 /* If GDB wanted this thread to single step, we always want to
2370 report the SIGTRAP, and let GDB handle it. Watchpoints should
2371 always be reported. So should signals we can't explain. A
2372 SIGTRAP we can't explain could be a GDB breakpoint --- we may or
2373 not support Z0 breakpoints. If we do, we're be able to handle
2374 GDB breakpoints on top of internal breakpoints, by handling the
2375 internal breakpoint and still reporting the event to GDB. If we
2376 don't, we're out of luck, GDB won't see the breakpoint hit. */
2377 report_to_gdb = (!maybe_internal_trap
2378 || current_inferior->last_resume_kind == resume_step
2379 || event_child->stopped_by_watchpoint
2380 || (!step_over_finished
2381 && !bp_explains_trap && !trace_event)
2382 || gdb_breakpoint_here (event_child->stop_pc));
2384 /* We found no reason GDB would want us to stop. We either hit one
2385 of our own breakpoints, or finished an internal step GDB
2386 shouldn't know about. */
2391 if (bp_explains_trap)
2392 fprintf (stderr, "Hit a gdbserver breakpoint.\n");
2393 if (step_over_finished)
2394 fprintf (stderr, "Step-over finished.\n");
2396 fprintf (stderr, "Tracepoint event.\n");
2399 /* We're not reporting this breakpoint to GDB, so apply the
2400 decr_pc_after_break adjustment to the inferior's regcache
2403 if (the_low_target.set_pc != NULL)
2405 struct regcache *regcache
2406 = get_thread_regcache (get_lwp_thread (event_child), 1);
2407 (*the_low_target.set_pc) (regcache, event_child->stop_pc);
2410 /* We may have finished stepping over a breakpoint. If so,
2411 we've stopped and suspended all LWPs momentarily except the
2412 stepping one. This is where we resume them all again. We're
2413 going to keep waiting, so use proceed, which handles stepping
2414 over the next breakpoint. */
2416 fprintf (stderr, "proceeding all threads.\n");
2418 if (step_over_finished)
2419 unsuspend_all_lwps (event_child);
2421 proceed_all_lwps ();
2427 if (current_inferior->last_resume_kind == resume_step)
2428 fprintf (stderr, "GDB wanted to single-step, reporting event.\n");
2429 if (event_child->stopped_by_watchpoint)
2430 fprintf (stderr, "Stopped by watchpoint.\n");
2431 if (gdb_breakpoint_here (event_child->stop_pc))
2432 fprintf (stderr, "Stopped by GDB breakpoint.\n");
2434 fprintf (stderr, "Hit a non-gdbserver trap event.\n");
2437 /* Alright, we're going to report a stop. */
2439 if (!non_stop && !stabilizing_threads)
2441 /* In all-stop, stop all threads. */
2442 stop_all_lwps (0, NULL);
2444 /* If we're not waiting for a specific LWP, choose an event LWP
2445 from among those that have had events. Giving equal priority
2446 to all LWPs that have had events helps prevent
2448 if (ptid_equal (ptid, minus_one_ptid))
2450 event_child->status_pending_p = 1;
2451 event_child->status_pending = w;
2453 select_event_lwp (&event_child);
2455 event_child->status_pending_p = 0;
2456 w = event_child->status_pending;
2459 /* Now that we've selected our final event LWP, cancel any
2460 breakpoints in other LWPs that have hit a GDB breakpoint.
2461 See the comment in cancel_breakpoints_callback to find out
2463 find_inferior (&all_lwps, cancel_breakpoints_callback, event_child);
2465 /* Stabilize threads (move out of jump pads). */
2466 stabilize_threads ();
2470 /* If we just finished a step-over, then all threads had been
2471 momentarily paused. In all-stop, that's fine, we want
2472 threads stopped by now anyway. In non-stop, we need to
2473 re-resume threads that GDB wanted to be running. */
2474 if (step_over_finished)
2475 unstop_all_lwps (1, event_child);
2478 ourstatus->kind = TARGET_WAITKIND_STOPPED;
2480 if (current_inferior->last_resume_kind == resume_stop
2481 && WSTOPSIG (w) == SIGSTOP)
2483 /* A thread that has been requested to stop by GDB with vCont;t,
2484 and it stopped cleanly, so report as SIG0. The use of
2485 SIGSTOP is an implementation detail. */
2486 ourstatus->value.sig = TARGET_SIGNAL_0;
2488 else if (current_inferior->last_resume_kind == resume_stop
2489 && WSTOPSIG (w) != SIGSTOP)
2491 /* A thread that has been requested to stop by GDB with vCont;t,
2492 but, it stopped for other reasons. */
2493 ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
2497 ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
2500 gdb_assert (ptid_equal (step_over_bkpt, null_ptid));
2503 fprintf (stderr, "linux_wait ret = %s, %d, %d\n",
2504 target_pid_to_str (ptid_of (event_child)),
2506 ourstatus->value.sig);
2508 return ptid_of (event_child);
2511 /* Get rid of any pending event in the pipe. */
2513 async_file_flush (void)
2519 ret = read (linux_event_pipe[0], &buf, 1);
2520 while (ret >= 0 || (ret == -1 && errno == EINTR));
2523 /* Put something in the pipe, so the event loop wakes up. */
2525 async_file_mark (void)
2529 async_file_flush ();
2532 ret = write (linux_event_pipe[1], "+", 1);
2533 while (ret == 0 || (ret == -1 && errno == EINTR));
2535 /* Ignore EAGAIN. If the pipe is full, the event loop will already
2536 be awakened anyway. */
2540 linux_wait (ptid_t ptid,
2541 struct target_waitstatus *ourstatus, int target_options)
2546 fprintf (stderr, "linux_wait: [%s]\n", target_pid_to_str (ptid));
2548 /* Flush the async file first. */
2549 if (target_is_async_p ())
2550 async_file_flush ();
2552 event_ptid = linux_wait_1 (ptid, ourstatus, target_options);
2554 /* If at least one stop was reported, there may be more. A single
2555 SIGCHLD can signal more than one child stop. */
2556 if (target_is_async_p ()
2557 && (target_options & TARGET_WNOHANG) != 0
2558 && !ptid_equal (event_ptid, null_ptid))
2564 /* Send a signal to an LWP. */
2567 kill_lwp (unsigned long lwpid, int signo)
2569 /* Use tkill, if possible, in case we are using nptl threads. If tkill
2570 fails, then we are not using nptl threads and we should be using kill. */
2574 static int tkill_failed;
2581 ret = syscall (__NR_tkill, lwpid, signo);
2582 if (errno != ENOSYS)
2589 return kill (lwpid, signo);
2593 linux_stop_lwp (struct lwp_info *lwp)
2599 send_sigstop (struct lwp_info *lwp)
2603 pid = lwpid_of (lwp);
2605 /* If we already have a pending stop signal for this process, don't
2607 if (lwp->stop_expected)
2610 fprintf (stderr, "Have pending sigstop for lwp %d\n", pid);
2616 fprintf (stderr, "Sending sigstop to lwp %d\n", pid);
2618 lwp->stop_expected = 1;
2619 kill_lwp (pid, SIGSTOP);
2623 send_sigstop_callback (struct inferior_list_entry *entry, void *except)
2625 struct lwp_info *lwp = (struct lwp_info *) entry;
2627 /* Ignore EXCEPT. */
2638 /* Increment the suspend count of an LWP, and stop it, if not stopped
2641 suspend_and_send_sigstop_callback (struct inferior_list_entry *entry,
2644 struct lwp_info *lwp = (struct lwp_info *) entry;
2646 /* Ignore EXCEPT. */
2652 return send_sigstop_callback (entry, except);
2656 mark_lwp_dead (struct lwp_info *lwp, int wstat)
2658 /* It's dead, really. */
2661 /* Store the exit status for later. */
2662 lwp->status_pending_p = 1;
2663 lwp->status_pending = wstat;
2665 /* Prevent trying to stop it. */
2668 /* No further stops are expected from a dead lwp. */
2669 lwp->stop_expected = 0;
2673 wait_for_sigstop (struct inferior_list_entry *entry)
2675 struct lwp_info *lwp = (struct lwp_info *) entry;
2676 struct thread_info *saved_inferior;
2685 fprintf (stderr, "wait_for_sigstop: LWP %ld already stopped\n",
2690 saved_inferior = current_inferior;
2691 if (saved_inferior != NULL)
2692 saved_tid = ((struct inferior_list_entry *) saved_inferior)->id;
2694 saved_tid = null_ptid; /* avoid bogus unused warning */
2696 ptid = lwp->head.id;
2699 fprintf (stderr, "wait_for_sigstop: pulling one event\n");
2701 pid = linux_wait_for_event (ptid, &wstat, __WALL);
2703 /* If we stopped with a non-SIGSTOP signal, save it for later
2704 and record the pending SIGSTOP. If the process exited, just
2706 if (WIFSTOPPED (wstat))
2709 fprintf (stderr, "LWP %ld stopped with signal %d\n",
2710 lwpid_of (lwp), WSTOPSIG (wstat));
2712 if (WSTOPSIG (wstat) != SIGSTOP)
2715 fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n",
2716 lwpid_of (lwp), wstat);
2718 lwp->status_pending_p = 1;
2719 lwp->status_pending = wstat;
2725 fprintf (stderr, "Process %d exited while stopping LWPs\n", pid);
2727 lwp = find_lwp_pid (pid_to_ptid (pid));
2730 /* Leave this status pending for the next time we're able to
2731 report it. In the mean time, we'll report this lwp as
2732 dead to GDB, so GDB doesn't try to read registers and
2733 memory from it. This can only happen if this was the
2734 last thread of the process; otherwise, PID is removed
2735 from the thread tables before linux_wait_for_event
2737 mark_lwp_dead (lwp, wstat);
2741 if (saved_inferior == NULL || linux_thread_alive (saved_tid))
2742 current_inferior = saved_inferior;
2746 fprintf (stderr, "Previously current thread died.\n");
2750 /* We can't change the current inferior behind GDB's back,
2751 otherwise, a subsequent command may apply to the wrong
2753 current_inferior = NULL;
2757 /* Set a valid thread as current. */
2758 set_desired_inferior (0);
2763 /* Returns true if LWP ENTRY is stopped in a jump pad, and we can't
2764 move it out, because we need to report the stop event to GDB. For
2765 example, if the user puts a breakpoint in the jump pad, it's
2766 because she wants to debug it. */
2769 stuck_in_jump_pad_callback (struct inferior_list_entry *entry, void *data)
2771 struct lwp_info *lwp = (struct lwp_info *) entry;
2772 struct thread_info *thread = get_lwp_thread (lwp);
2774 gdb_assert (lwp->suspended == 0);
2775 gdb_assert (lwp->stopped);
2777 /* Allow debugging the jump pad, gdb_collect, etc.. */
2778 return (supports_fast_tracepoints ()
2779 && in_process_agent_loaded ()
2780 && (gdb_breakpoint_here (lwp->stop_pc)
2781 || lwp->stopped_by_watchpoint
2782 || thread->last_resume_kind == resume_step)
2783 && linux_fast_tracepoint_collecting (lwp, NULL));
2787 move_out_of_jump_pad_callback (struct inferior_list_entry *entry)
2789 struct lwp_info *lwp = (struct lwp_info *) entry;
2790 struct thread_info *thread = get_lwp_thread (lwp);
2793 gdb_assert (lwp->suspended == 0);
2794 gdb_assert (lwp->stopped);
2796 wstat = lwp->status_pending_p ? &lwp->status_pending : NULL;
2798 /* Allow debugging the jump pad, gdb_collect, etc. */
2799 if (!gdb_breakpoint_here (lwp->stop_pc)
2800 && !lwp->stopped_by_watchpoint
2801 && thread->last_resume_kind != resume_step
2802 && maybe_move_out_of_jump_pad (lwp, wstat))
2806 "LWP %ld needs stabilizing (in jump pad)\n",
2811 lwp->status_pending_p = 0;
2812 enqueue_one_deferred_signal (lwp, wstat);
2816 "Signal %d for LWP %ld deferred "
2818 WSTOPSIG (*wstat), lwpid_of (lwp));
2821 linux_resume_one_lwp (lwp, 0, 0, NULL);
2828 lwp_running (struct inferior_list_entry *entry, void *data)
2830 struct lwp_info *lwp = (struct lwp_info *) entry;
2839 /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
2840 If SUSPEND, then also increase the suspend count of every LWP,
2844 stop_all_lwps (int suspend, struct lwp_info *except)
2846 stopping_threads = 1;
2849 find_inferior (&all_lwps, suspend_and_send_sigstop_callback, except);
2851 find_inferior (&all_lwps, send_sigstop_callback, except);
2852 for_each_inferior (&all_lwps, wait_for_sigstop);
2853 stopping_threads = 0;
2856 /* Resume execution of the inferior process.
2857 If STEP is nonzero, single-step it.
2858 If SIGNAL is nonzero, give it that signal. */
2861 linux_resume_one_lwp (struct lwp_info *lwp,
2862 int step, int signal, siginfo_t *info)
2864 struct thread_info *saved_inferior;
2865 int fast_tp_collecting;
2867 if (lwp->stopped == 0)
2870 fast_tp_collecting = lwp->collecting_fast_tracepoint;
2872 gdb_assert (!stabilizing_threads || fast_tp_collecting);
2874 /* Cancel actions that rely on GDB not changing the PC (e.g., the
2875 user used the "jump" command, or "set $pc = foo"). */
2876 if (lwp->stop_pc != get_pc (lwp))
2878 /* Collecting 'while-stepping' actions doesn't make sense
2880 release_while_stepping_state_list (get_lwp_thread (lwp));
2883 /* If we have pending signals or status, and a new signal, enqueue the
2884 signal. Also enqueue the signal if we are waiting to reinsert a
2885 breakpoint; it will be picked up again below. */
2887 && (lwp->status_pending_p
2888 || lwp->pending_signals != NULL
2889 || lwp->bp_reinsert != 0
2890 || fast_tp_collecting))
2892 struct pending_signals *p_sig;
2893 p_sig = xmalloc (sizeof (*p_sig));
2894 p_sig->prev = lwp->pending_signals;
2895 p_sig->signal = signal;
2897 memset (&p_sig->info, 0, sizeof (siginfo_t));
2899 memcpy (&p_sig->info, info, sizeof (siginfo_t));
2900 lwp->pending_signals = p_sig;
2903 if (lwp->status_pending_p)
2906 fprintf (stderr, "Not resuming lwp %ld (%s, signal %d, stop %s);"
2907 " has pending status\n",
2908 lwpid_of (lwp), step ? "step" : "continue", signal,
2909 lwp->stop_expected ? "expected" : "not expected");
2913 saved_inferior = current_inferior;
2914 current_inferior = get_lwp_thread (lwp);
2917 fprintf (stderr, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
2918 lwpid_of (lwp), step ? "step" : "continue", signal,
2919 lwp->stop_expected ? "expected" : "not expected");
2921 /* This bit needs some thinking about. If we get a signal that
2922 we must report while a single-step reinsert is still pending,
2923 we often end up resuming the thread. It might be better to
2924 (ew) allow a stack of pending events; then we could be sure that
2925 the reinsert happened right away and not lose any signals.
2927 Making this stack would also shrink the window in which breakpoints are
2928 uninserted (see comment in linux_wait_for_lwp) but not enough for
2929 complete correctness, so it won't solve that problem. It may be
2930 worthwhile just to solve this one, however. */
2931 if (lwp->bp_reinsert != 0)
2934 fprintf (stderr, " pending reinsert at 0x%s\n",
2935 paddress (lwp->bp_reinsert));
2937 if (lwp->bp_reinsert != 0 && can_hardware_single_step ())
2939 if (fast_tp_collecting == 0)
2942 fprintf (stderr, "BAD - reinserting but not stepping.\n");
2944 fprintf (stderr, "BAD - reinserting and suspended(%d).\n",
2951 /* Postpone any pending signal. It was enqueued above. */
2955 if (fast_tp_collecting == 1)
2959 lwp %ld wants to get out of fast tracepoint jump pad (exit-jump-pad-bkpt)\n",
2962 /* Postpone any pending signal. It was enqueued above. */
2965 else if (fast_tp_collecting == 2)
2969 lwp %ld wants to get out of fast tracepoint jump pad single-stepping\n",
2972 if (can_hardware_single_step ())
2975 fatal ("moving out of jump pad single-stepping"
2976 " not implemented on this target");
2978 /* Postpone any pending signal. It was enqueued above. */
2982 /* If we have while-stepping actions in this thread set it stepping.
2983 If we have a signal to deliver, it may or may not be set to
2984 SIG_IGN, we don't know. Assume so, and allow collecting
2985 while-stepping into a signal handler. A possible smart thing to
2986 do would be to set an internal breakpoint at the signal return
2987 address, continue, and carry on catching this while-stepping
2988 action only when that breakpoint is hit. A future
2990 if (get_lwp_thread (lwp)->while_stepping != NULL
2991 && can_hardware_single_step ())
2995 "lwp %ld has a while-stepping action -> forcing step.\n",
3000 if (debug_threads && the_low_target.get_pc != NULL)
3002 struct regcache *regcache = get_thread_regcache (current_inferior, 1);
3003 CORE_ADDR pc = (*the_low_target.get_pc) (regcache);
3004 fprintf (stderr, " resuming from pc 0x%lx\n", (long) pc);
3007 /* If we have pending signals, consume one unless we are trying to
3008 reinsert a breakpoint or we're trying to finish a fast tracepoint
3010 if (lwp->pending_signals != NULL
3011 && lwp->bp_reinsert == 0
3012 && fast_tp_collecting == 0)
3014 struct pending_signals **p_sig;
3016 p_sig = &lwp->pending_signals;
3017 while ((*p_sig)->prev != NULL)
3018 p_sig = &(*p_sig)->prev;
3020 signal = (*p_sig)->signal;
3021 if ((*p_sig)->info.si_signo != 0)
3022 ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &(*p_sig)->info);
3028 if (the_low_target.prepare_to_resume != NULL)
3029 the_low_target.prepare_to_resume (lwp);
3031 regcache_invalidate_one ((struct inferior_list_entry *)
3032 get_lwp_thread (lwp));
3035 lwp->stopped_by_watchpoint = 0;
3036 lwp->stepping = step;
3037 ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (lwp), 0,
3038 /* Coerce to a uintptr_t first to avoid potential gcc warning
3039 of coercing an 8 byte integer to a 4 byte pointer. */
3040 (PTRACE_ARG4_TYPE) (uintptr_t) signal);
3042 current_inferior = saved_inferior;
3045 /* ESRCH from ptrace either means that the thread was already
3046 running (an error) or that it is gone (a race condition). If
3047 it's gone, we will get a notification the next time we wait,
3048 so we can ignore the error. We could differentiate these
3049 two, but it's tricky without waiting; the thread still exists
3050 as a zombie, so sending it signal 0 would succeed. So just
3055 perror_with_name ("ptrace");
3059 struct thread_resume_array
3061 struct thread_resume *resume;
3065 /* This function is called once per thread. We look up the thread
3066 in RESUME_PTR, and mark the thread with a pointer to the appropriate
3069 This algorithm is O(threads * resume elements), but resume elements
3070 is small (and will remain small at least until GDB supports thread
3073 linux_set_resume_request (struct inferior_list_entry *entry, void *arg)
3075 struct lwp_info *lwp;
3076 struct thread_info *thread;
3078 struct thread_resume_array *r;
3080 thread = (struct thread_info *) entry;
3081 lwp = get_thread_lwp (thread);
3084 for (ndx = 0; ndx < r->n; ndx++)
3086 ptid_t ptid = r->resume[ndx].thread;
3087 if (ptid_equal (ptid, minus_one_ptid)
3088 || ptid_equal (ptid, entry->id)
3089 || (ptid_is_pid (ptid)
3090 && (ptid_get_pid (ptid) == pid_of (lwp)))
3091 || (ptid_get_lwp (ptid) == -1
3092 && (ptid_get_pid (ptid) == pid_of (lwp))))
3094 if (r->resume[ndx].kind == resume_stop
3095 && thread->last_resume_kind == resume_stop)
3098 fprintf (stderr, "already %s LWP %ld at GDB's request\n",
3099 thread->last_status.kind == TARGET_WAITKIND_STOPPED
3107 lwp->resume = &r->resume[ndx];
3108 thread->last_resume_kind = lwp->resume->kind;
3110 /* If we had a deferred signal to report, dequeue one now.
3111 This can happen if LWP gets more than one signal while
3112 trying to get out of a jump pad. */
3114 && !lwp->status_pending_p
3115 && dequeue_one_deferred_signal (lwp, &lwp->status_pending))
3117 lwp->status_pending_p = 1;
3121 "Dequeueing deferred signal %d for LWP %ld, "
3122 "leaving status pending.\n",
3123 WSTOPSIG (lwp->status_pending), lwpid_of (lwp));
3130 /* No resume action for this thread. */
3137 /* Set *FLAG_P if this lwp has an interesting status pending. */
3139 resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p)
3141 struct lwp_info *lwp = (struct lwp_info *) entry;
3143 /* LWPs which will not be resumed are not interesting, because
3144 we might not wait for them next time through linux_wait. */
3145 if (lwp->resume == NULL)
3148 if (lwp->status_pending_p)
3149 * (int *) flag_p = 1;
3154 /* Return 1 if this lwp that GDB wants running is stopped at an
3155 internal breakpoint that we need to step over. It assumes that any
3156 required STOP_PC adjustment has already been propagated to the
3157 inferior's regcache. */
3160 need_step_over_p (struct inferior_list_entry *entry, void *dummy)
3162 struct lwp_info *lwp = (struct lwp_info *) entry;
3163 struct thread_info *thread;
3164 struct thread_info *saved_inferior;
3167 /* LWPs which will not be resumed are not interesting, because we
3168 might not wait for them next time through linux_wait. */
3174 "Need step over [LWP %ld]? Ignoring, not stopped\n",
3179 thread = get_lwp_thread (lwp);
3181 if (thread->last_resume_kind == resume_stop)
3185 "Need step over [LWP %ld]? Ignoring, should remain stopped\n",
3190 gdb_assert (lwp->suspended >= 0);
3196 "Need step over [LWP %ld]? Ignoring, suspended\n",
3201 if (!lwp->need_step_over)
3205 "Need step over [LWP %ld]? No\n", lwpid_of (lwp));
3208 if (lwp->status_pending_p)
3212 "Need step over [LWP %ld]? Ignoring, has pending status.\n",
3217 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
3221 /* If the PC has changed since we stopped, then don't do anything,
3222 and let the breakpoint/tracepoint be hit. This happens if, for
3223 instance, GDB handled the decr_pc_after_break subtraction itself,
3224 GDB is OOL stepping this thread, or the user has issued a "jump"
3225 command, or poked thread's registers herself. */
3226 if (pc != lwp->stop_pc)
3230 "Need step over [LWP %ld]? Cancelling, PC was changed. "
3231 "Old stop_pc was 0x%s, PC is now 0x%s\n",
3232 lwpid_of (lwp), paddress (lwp->stop_pc), paddress (pc));
3234 lwp->need_step_over = 0;
3238 saved_inferior = current_inferior;
3239 current_inferior = thread;
3241 /* We can only step over breakpoints we know about. */
3242 if (breakpoint_here (pc) || fast_tracepoint_jump_here (pc))
3244 /* Don't step over a breakpoint that GDB expects to hit
3246 if (gdb_breakpoint_here (pc))
3250 "Need step over [LWP %ld]? yes, but found"
3251 " GDB breakpoint at 0x%s; skipping step over\n",
3252 lwpid_of (lwp), paddress (pc));
3254 current_inferior = saved_inferior;
3261 "Need step over [LWP %ld]? yes, "
3262 "found breakpoint at 0x%s\n",
3263 lwpid_of (lwp), paddress (pc));
3265 /* We've found an lwp that needs stepping over --- return 1 so
3266 that find_inferior stops looking. */
3267 current_inferior = saved_inferior;
3269 /* If the step over is cancelled, this is set again. */
3270 lwp->need_step_over = 0;
3275 current_inferior = saved_inferior;
3279 "Need step over [LWP %ld]? No, no breakpoint found at 0x%s\n",
3280 lwpid_of (lwp), paddress (pc));
3285 /* Start a step-over operation on LWP. When LWP stopped at a
3286 breakpoint, to make progress, we need to remove the breakpoint out
3287 of the way. If we let other threads run while we do that, they may
3288 pass by the breakpoint location and miss hitting it. To avoid
3289 that, a step-over momentarily stops all threads while LWP is
3290 single-stepped while the breakpoint is temporarily uninserted from
3291 the inferior. When the single-step finishes, we reinsert the
3292 breakpoint, and let all threads that are supposed to be running,
3295 On targets that don't support hardware single-step, we don't
3296 currently support full software single-stepping. Instead, we only
3297 support stepping over the thread event breakpoint, by asking the
3298 low target where to place a reinsert breakpoint. Since this
3299 routine assumes the breakpoint being stepped over is a thread event
3300 breakpoint, it usually assumes the return address of the current
3301 function is a good enough place to set the reinsert breakpoint. */
3304 start_step_over (struct lwp_info *lwp)
3306 struct thread_info *saved_inferior;
3312 "Starting step-over on LWP %ld. Stopping all threads\n",
3315 stop_all_lwps (1, lwp);
3316 gdb_assert (lwp->suspended == 0);
3319 fprintf (stderr, "Done stopping all threads for step-over.\n");
3321 /* Note, we should always reach here with an already adjusted PC,
3322 either by GDB (if we're resuming due to GDB's request), or by our
3323 caller, if we just finished handling an internal breakpoint GDB
3324 shouldn't care about. */
3327 saved_inferior = current_inferior;
3328 current_inferior = get_lwp_thread (lwp);
3330 lwp->bp_reinsert = pc;
3331 uninsert_breakpoints_at (pc);
3332 uninsert_fast_tracepoint_jumps_at (pc);
3334 if (can_hardware_single_step ())
3340 CORE_ADDR raddr = (*the_low_target.breakpoint_reinsert_addr) ();
3341 set_reinsert_breakpoint (raddr);
3345 current_inferior = saved_inferior;
3347 linux_resume_one_lwp (lwp, step, 0, NULL);
3349 /* Require next event from this LWP. */
3350 step_over_bkpt = lwp->head.id;
3354 /* Finish a step-over. Reinsert the breakpoint we had uninserted in
3355 start_step_over, if still there, and delete any reinsert
3356 breakpoints we've set, on non hardware single-step targets. */
3359 finish_step_over (struct lwp_info *lwp)
3361 if (lwp->bp_reinsert != 0)
3364 fprintf (stderr, "Finished step over.\n");
3366 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
3367 may be no breakpoint to reinsert there by now. */
3368 reinsert_breakpoints_at (lwp->bp_reinsert);
3369 reinsert_fast_tracepoint_jumps_at (lwp->bp_reinsert);
3371 lwp->bp_reinsert = 0;
3373 /* Delete any software-single-step reinsert breakpoints. No
3374 longer needed. We don't have to worry about other threads
3375 hitting this trap, and later not being able to explain it,
3376 because we were stepping over a breakpoint, and we hold all
3377 threads but LWP stopped while doing that. */
3378 if (!can_hardware_single_step ())
3379 delete_reinsert_breakpoints ();
3381 step_over_bkpt = null_ptid;
3388 /* This function is called once per thread. We check the thread's resume
3389 request, which will tell us whether to resume, step, or leave the thread
3390 stopped; and what signal, if any, it should be sent.
3392 For threads which we aren't explicitly told otherwise, we preserve
3393 the stepping flag; this is used for stepping over gdbserver-placed
3396 If pending_flags was set in any thread, we queue any needed
3397 signals, since we won't actually resume. We already have a pending
3398 event to report, so we don't need to preserve any step requests;
3399 they should be re-issued if necessary. */
3402 linux_resume_one_thread (struct inferior_list_entry *entry, void *arg)
3404 struct lwp_info *lwp;
3405 struct thread_info *thread;
3407 int leave_all_stopped = * (int *) arg;
3410 thread = (struct thread_info *) entry;
3411 lwp = get_thread_lwp (thread);
3413 if (lwp->resume == NULL)
3416 if (lwp->resume->kind == resume_stop)
3419 fprintf (stderr, "resume_stop request for LWP %ld\n", lwpid_of (lwp));
3424 fprintf (stderr, "stopping LWP %ld\n", lwpid_of (lwp));
3426 /* Stop the thread, and wait for the event asynchronously,
3427 through the event loop. */
3433 fprintf (stderr, "already stopped LWP %ld\n",
3436 /* The LWP may have been stopped in an internal event that
3437 was not meant to be notified back to GDB (e.g., gdbserver
3438 breakpoint), so we should be reporting a stop event in
3441 /* If the thread already has a pending SIGSTOP, this is a
3442 no-op. Otherwise, something later will presumably resume
3443 the thread and this will cause it to cancel any pending
3444 operation, due to last_resume_kind == resume_stop. If
3445 the thread already has a pending status to report, we
3446 will still report it the next time we wait - see
3447 status_pending_p_callback. */
3449 /* If we already have a pending signal to report, then
3450 there's no need to queue a SIGSTOP, as this means we're
3451 midway through moving the LWP out of the jumppad, and we
3452 will report the pending signal as soon as that is
3454 if (lwp->pending_signals_to_report == NULL)
3458 /* For stop requests, we're done. */
3460 thread->last_status.kind = TARGET_WAITKIND_IGNORE;
3464 /* If this thread which is about to be resumed has a pending status,
3465 then don't resume any threads - we can just report the pending
3466 status. Make sure to queue any signals that would otherwise be
3467 sent. In all-stop mode, we do this decision based on if *any*
3468 thread has a pending status. If there's a thread that needs the
3469 step-over-breakpoint dance, then don't resume any other thread
3470 but that particular one. */
3471 leave_pending = (lwp->status_pending_p || leave_all_stopped);
3476 fprintf (stderr, "resuming LWP %ld\n", lwpid_of (lwp));
3478 step = (lwp->resume->kind == resume_step);
3479 linux_resume_one_lwp (lwp, step, lwp->resume->sig, NULL);
3484 fprintf (stderr, "leaving LWP %ld stopped\n", lwpid_of (lwp));
3486 /* If we have a new signal, enqueue the signal. */
3487 if (lwp->resume->sig != 0)
3489 struct pending_signals *p_sig;
3490 p_sig = xmalloc (sizeof (*p_sig));
3491 p_sig->prev = lwp->pending_signals;
3492 p_sig->signal = lwp->resume->sig;
3493 memset (&p_sig->info, 0, sizeof (siginfo_t));
3495 /* If this is the same signal we were previously stopped by,
3496 make sure to queue its siginfo. We can ignore the return
3497 value of ptrace; if it fails, we'll skip
3498 PTRACE_SETSIGINFO. */
3499 if (WIFSTOPPED (lwp->last_status)
3500 && WSTOPSIG (lwp->last_status) == lwp->resume->sig)
3501 ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info);
3503 lwp->pending_signals = p_sig;
3507 thread->last_status.kind = TARGET_WAITKIND_IGNORE;
3513 linux_resume (struct thread_resume *resume_info, size_t n)
3515 struct thread_resume_array array = { resume_info, n };
3516 struct lwp_info *need_step_over = NULL;
3518 int leave_all_stopped;
3520 find_inferior (&all_threads, linux_set_resume_request, &array);
3522 /* If there is a thread which would otherwise be resumed, which has
3523 a pending status, then don't resume any threads - we can just
3524 report the pending status. Make sure to queue any signals that
3525 would otherwise be sent. In non-stop mode, we'll apply this
3526 logic to each thread individually. We consume all pending events
3527 before considering to start a step-over (in all-stop). */
3530 find_inferior (&all_lwps, resume_status_pending_p, &any_pending);
3532 /* If there is a thread which would otherwise be resumed, which is
3533 stopped at a breakpoint that needs stepping over, then don't
3534 resume any threads - have it step over the breakpoint with all
3535 other threads stopped, then resume all threads again. Make sure
3536 to queue any signals that would otherwise be delivered or
3538 if (!any_pending && supports_breakpoints ())
3540 = (struct lwp_info *) find_inferior (&all_lwps,
3541 need_step_over_p, NULL);
3543 leave_all_stopped = (need_step_over != NULL || any_pending);
3547 if (need_step_over != NULL)
3548 fprintf (stderr, "Not resuming all, need step over\n");
3549 else if (any_pending)
3551 "Not resuming, all-stop and found "
3552 "an LWP with pending status\n");
3554 fprintf (stderr, "Resuming, no pending status or step over needed\n");
3557 /* Even if we're leaving threads stopped, queue all signals we'd
3558 otherwise deliver. */
3559 find_inferior (&all_threads, linux_resume_one_thread, &leave_all_stopped);
3562 start_step_over (need_step_over);
3565 /* This function is called once per thread. We check the thread's
3566 last resume request, which will tell us whether to resume, step, or
3567 leave the thread stopped. Any signal the client requested to be
3568 delivered has already been enqueued at this point.
3570 If any thread that GDB wants running is stopped at an internal
3571 breakpoint that needs stepping over, we start a step-over operation
3572 on that particular thread, and leave all others stopped. */
3575 proceed_one_lwp (struct inferior_list_entry *entry, void *except)
3577 struct lwp_info *lwp = (struct lwp_info *) entry;
3578 struct thread_info *thread;
3586 "proceed_one_lwp: lwp %ld\n", lwpid_of (lwp));
3591 fprintf (stderr, " LWP %ld already running\n", lwpid_of (lwp));
3595 thread = get_lwp_thread (lwp);
3597 if (thread->last_resume_kind == resume_stop
3598 && thread->last_status.kind != TARGET_WAITKIND_IGNORE)
3601 fprintf (stderr, " client wants LWP to remain %ld stopped\n",
3606 if (lwp->status_pending_p)
3609 fprintf (stderr, " LWP %ld has pending status, leaving stopped\n",
3614 gdb_assert (lwp->suspended >= 0);
3619 fprintf (stderr, " LWP %ld is suspended\n", lwpid_of (lwp));
3623 if (thread->last_resume_kind == resume_stop
3624 && lwp->pending_signals_to_report == NULL
3625 && lwp->collecting_fast_tracepoint == 0)
3627 /* We haven't reported this LWP as stopped yet (otherwise, the
3628 last_status.kind check above would catch it, and we wouldn't
3629 reach here. This LWP may have been momentarily paused by a
3630 stop_all_lwps call while handling for example, another LWP's
3631 step-over. In that case, the pending expected SIGSTOP signal
3632 that was queued at vCont;t handling time will have already
3633 been consumed by wait_for_sigstop, and so we need to requeue
3634 another one here. Note that if the LWP already has a SIGSTOP
3635 pending, this is a no-op. */
3639 "Client wants LWP %ld to stop. "
3640 "Making sure it has a SIGSTOP pending\n",
3646 step = thread->last_resume_kind == resume_step;
3647 linux_resume_one_lwp (lwp, step, 0, NULL);
3652 unsuspend_and_proceed_one_lwp (struct inferior_list_entry *entry, void *except)
3654 struct lwp_info *lwp = (struct lwp_info *) entry;
3660 gdb_assert (lwp->suspended >= 0);
3662 return proceed_one_lwp (entry, except);
3665 /* When we finish a step-over, set threads running again. If there's
3666 another thread that may need a step-over, now's the time to start
3667 it. Eventually, we'll move all threads past their breakpoints. */
3670 proceed_all_lwps (void)
3672 struct lwp_info *need_step_over;
3674 /* If there is a thread which would otherwise be resumed, which is
3675 stopped at a breakpoint that needs stepping over, then don't
3676 resume any threads - have it step over the breakpoint with all
3677 other threads stopped, then resume all threads again. */
3679 if (supports_breakpoints ())
3682 = (struct lwp_info *) find_inferior (&all_lwps,
3683 need_step_over_p, NULL);
3685 if (need_step_over != NULL)
3688 fprintf (stderr, "proceed_all_lwps: found "
3689 "thread %ld needing a step-over\n",
3690 lwpid_of (need_step_over));
3692 start_step_over (need_step_over);
3698 fprintf (stderr, "Proceeding, no step-over needed\n");
3700 find_inferior (&all_lwps, proceed_one_lwp, NULL);
3703 /* Stopped LWPs that the client wanted to be running, that don't have
3704 pending statuses, are set to run again, except for EXCEPT, if not
3705 NULL. This undoes a stop_all_lwps call. */
3708 unstop_all_lwps (int unsuspend, struct lwp_info *except)
3714 "unstopping all lwps, except=(LWP %ld)\n", lwpid_of (except));
3717 "unstopping all lwps\n");
3721 find_inferior (&all_lwps, unsuspend_and_proceed_one_lwp, except);
3723 find_inferior (&all_lwps, proceed_one_lwp, except);
3726 #ifdef HAVE_LINUX_USRREGS
3729 register_addr (int regnum)
3733 if (regnum < 0 || regnum >= the_low_target.num_regs)
3734 error ("Invalid register number %d.", regnum);
3736 addr = the_low_target.regmap[regnum];
3741 /* Fetch one register. */
3743 fetch_register (struct regcache *regcache, int regno)
3750 if (regno >= the_low_target.num_regs)
3752 if ((*the_low_target.cannot_fetch_register) (regno))
3755 regaddr = register_addr (regno);
3759 size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
3760 & -sizeof (PTRACE_XFER_TYPE));
3761 buf = alloca (size);
3763 pid = lwpid_of (get_thread_lwp (current_inferior));
3764 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
3767 *(PTRACE_XFER_TYPE *) (buf + i) =
3768 ptrace (PTRACE_PEEKUSER, pid,
3769 /* Coerce to a uintptr_t first to avoid potential gcc warning
3770 of coercing an 8 byte integer to a 4 byte pointer. */
3771 (PTRACE_ARG3_TYPE) (uintptr_t) regaddr, 0);
3772 regaddr += sizeof (PTRACE_XFER_TYPE);
3774 error ("reading register %d: %s", regno, strerror (errno));
3777 if (the_low_target.supply_ptrace_register)
3778 the_low_target.supply_ptrace_register (regcache, regno, buf);
3780 supply_register (regcache, regno, buf);
3783 /* Store one register. */
3785 store_register (struct regcache *regcache, int regno)
3792 if (regno >= the_low_target.num_regs)
3794 if ((*the_low_target.cannot_store_register) (regno))
3797 regaddr = register_addr (regno);
3801 size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
3802 & -sizeof (PTRACE_XFER_TYPE));
3803 buf = alloca (size);
3804 memset (buf, 0, size);
3806 if (the_low_target.collect_ptrace_register)
3807 the_low_target.collect_ptrace_register (regcache, regno, buf);
3809 collect_register (regcache, regno, buf);
3811 pid = lwpid_of (get_thread_lwp (current_inferior));
3812 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
3815 ptrace (PTRACE_POKEUSER, pid,
3816 /* Coerce to a uintptr_t first to avoid potential gcc warning
3817 about coercing an 8 byte integer to a 4 byte pointer. */
3818 (PTRACE_ARG3_TYPE) (uintptr_t) regaddr,
3819 (PTRACE_ARG4_TYPE) *(PTRACE_XFER_TYPE *) (buf + i));
3822 /* At this point, ESRCH should mean the process is
3823 already gone, in which case we simply ignore attempts
3824 to change its registers. See also the related
3825 comment in linux_resume_one_lwp. */
3829 if ((*the_low_target.cannot_store_register) (regno) == 0)
3830 error ("writing register %d: %s", regno, strerror (errno));
3832 regaddr += sizeof (PTRACE_XFER_TYPE);
3836 /* Fetch all registers, or just one, from the child process. */
3838 usr_fetch_inferior_registers (struct regcache *regcache, int regno)
3841 for (regno = 0; regno < the_low_target.num_regs; regno++)
3842 fetch_register (regcache, regno);
3844 fetch_register (regcache, regno);
3847 /* Store our register values back into the inferior.
3848 If REGNO is -1, do this for all registers.
3849 Otherwise, REGNO specifies which register (so we can save time). */
3851 usr_store_inferior_registers (struct regcache *regcache, int regno)
3854 for (regno = 0; regno < the_low_target.num_regs; regno++)
3855 store_register (regcache, regno);
3857 store_register (regcache, regno);
3859 #endif /* HAVE_LINUX_USRREGS */
3863 #ifdef HAVE_LINUX_REGSETS
3866 regsets_fetch_inferior_registers (struct regcache *regcache)
3868 struct regset_info *regset;
3869 int saw_general_regs = 0;
3873 regset = target_regsets;
3875 pid = lwpid_of (get_thread_lwp (current_inferior));
3876 while (regset->size >= 0)
3881 if (regset->size == 0 || disabled_regsets[regset - target_regsets])
3887 buf = xmalloc (regset->size);
3889 nt_type = regset->nt_type;
3893 iov.iov_len = regset->size;
3894 data = (void *) &iov;
3900 res = ptrace (regset->get_request, pid, nt_type, data);
3902 res = ptrace (regset->get_request, pid, data, nt_type);
3908 /* If we get EIO on a regset, do not try it again for
3910 disabled_regsets[regset - target_regsets] = 1;
3917 sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d",
3922 else if (regset->type == GENERAL_REGS)
3923 saw_general_regs = 1;
3924 regset->store_function (regcache, buf);
3928 if (saw_general_regs)
3935 regsets_store_inferior_registers (struct regcache *regcache)
3937 struct regset_info *regset;
3938 int saw_general_regs = 0;
3942 regset = target_regsets;
3944 pid = lwpid_of (get_thread_lwp (current_inferior));
3945 while (regset->size >= 0)
3950 if (regset->size == 0 || disabled_regsets[regset - target_regsets])
3956 buf = xmalloc (regset->size);
3958 /* First fill the buffer with the current register set contents,
3959 in case there are any items in the kernel's regset that are
3960 not in gdbserver's regcache. */
3962 nt_type = regset->nt_type;
3966 iov.iov_len = regset->size;
3967 data = (void *) &iov;
3973 res = ptrace (regset->get_request, pid, nt_type, data);
3975 res = ptrace (regset->get_request, pid, &iov, data);
3980 /* Then overlay our cached registers on that. */
3981 regset->fill_function (regcache, buf);
3983 /* Only now do we write the register set. */
3985 res = ptrace (regset->set_request, pid, nt_type, data);
3987 res = ptrace (regset->set_request, pid, data, nt_type);
3995 /* If we get EIO on a regset, do not try it again for
3997 disabled_regsets[regset - target_regsets] = 1;
4001 else if (errno == ESRCH)
4003 /* At this point, ESRCH should mean the process is
4004 already gone, in which case we simply ignore attempts
4005 to change its registers. See also the related
4006 comment in linux_resume_one_lwp. */
4012 perror ("Warning: ptrace(regsets_store_inferior_registers)");
4015 else if (regset->type == GENERAL_REGS)
4016 saw_general_regs = 1;
4020 if (saw_general_regs)
4027 #endif /* HAVE_LINUX_REGSETS */
4031 linux_fetch_registers (struct regcache *regcache, int regno)
4033 #ifdef HAVE_LINUX_REGSETS
4034 if (regsets_fetch_inferior_registers (regcache) == 0)
4037 #ifdef HAVE_LINUX_USRREGS
4038 usr_fetch_inferior_registers (regcache, regno);
4043 linux_store_registers (struct regcache *regcache, int regno)
4045 #ifdef HAVE_LINUX_REGSETS
4046 if (regsets_store_inferior_registers (regcache) == 0)
4049 #ifdef HAVE_LINUX_USRREGS
4050 usr_store_inferior_registers (regcache, regno);
4055 /* Copy LEN bytes from inferior's memory starting at MEMADDR
4056 to debugger memory starting at MYADDR. */
4059 linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
4062 /* Round starting address down to longword boundary. */
4063 register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
4064 /* Round ending address up; get number of longwords that makes. */
4066 = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
4067 / sizeof (PTRACE_XFER_TYPE);
4068 /* Allocate buffer of that many longwords. */
4069 register PTRACE_XFER_TYPE *buffer
4070 = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
4073 int pid = lwpid_of (get_thread_lwp (current_inferior));
4075 /* Try using /proc. Don't bother for one word. */
4076 if (len >= 3 * sizeof (long))
4078 /* We could keep this file open and cache it - possibly one per
4079 thread. That requires some juggling, but is even faster. */
4080 sprintf (filename, "/proc/%d/mem", pid);
4081 fd = open (filename, O_RDONLY | O_LARGEFILE);
4085 /* If pread64 is available, use it. It's faster if the kernel
4086 supports it (only one syscall), and it's 64-bit safe even on
4087 32-bit platforms (for instance, SPARC debugging a SPARC64
4090 if (pread64 (fd, myaddr, len, memaddr) != len)
4092 if (lseek (fd, memaddr, SEEK_SET) == -1 || read (fd, myaddr, len) != len)
4104 /* Read all the longwords */
4105 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
4108 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
4109 about coercing an 8 byte integer to a 4 byte pointer. */
4110 buffer[i] = ptrace (PTRACE_PEEKTEXT, pid,
4111 (PTRACE_ARG3_TYPE) (uintptr_t) addr, 0);
4116 /* Copy appropriate bytes out of the buffer. */
4118 (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
4124 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
4125 memory at MEMADDR. On failure (cannot write to the inferior)
4126 returns the value of errno. */
4129 linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
4132 /* Round starting address down to longword boundary. */
4133 register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
4134 /* Round ending address up; get number of longwords that makes. */
4136 = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
4137 / sizeof (PTRACE_XFER_TYPE);
4139 /* Allocate buffer of that many longwords. */
4140 register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *)
4141 alloca (count * sizeof (PTRACE_XFER_TYPE));
4143 int pid = lwpid_of (get_thread_lwp (current_inferior));
4147 /* Dump up to four bytes. */
4148 unsigned int val = * (unsigned int *) myaddr;
4154 val = val & 0xffffff;
4155 fprintf (stderr, "Writing %0*x to 0x%08lx\n", 2 * ((len < 4) ? len : 4),
4156 val, (long)memaddr);
4159 /* Fill start and end extra bytes of buffer with existing memory data. */
4162 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
4163 about coercing an 8 byte integer to a 4 byte pointer. */
4164 buffer[0] = ptrace (PTRACE_PEEKTEXT, pid,
4165 (PTRACE_ARG3_TYPE) (uintptr_t) addr, 0);
4173 = ptrace (PTRACE_PEEKTEXT, pid,
4174 /* Coerce to a uintptr_t first to avoid potential gcc warning
4175 about coercing an 8 byte integer to a 4 byte pointer. */
4176 (PTRACE_ARG3_TYPE) (uintptr_t) (addr + (count - 1)
4177 * sizeof (PTRACE_XFER_TYPE)),
4183 /* Copy data to be written over corresponding part of buffer. */
4185 memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
4188 /* Write the entire buffer. */
4190 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
4193 ptrace (PTRACE_POKETEXT, pid,
4194 /* Coerce to a uintptr_t first to avoid potential gcc warning
4195 about coercing an 8 byte integer to a 4 byte pointer. */
4196 (PTRACE_ARG3_TYPE) (uintptr_t) addr,
4197 (PTRACE_ARG4_TYPE) buffer[i]);
4205 /* Non-zero if the kernel supports PTRACE_O_TRACEFORK. */
4206 static int linux_supports_tracefork_flag;
4209 linux_enable_event_reporting (int pid)
4211 if (!linux_supports_tracefork_flag)
4214 ptrace (PTRACE_SETOPTIONS, pid, 0, (PTRACE_ARG4_TYPE) PTRACE_O_TRACECLONE);
4217 /* Helper functions for linux_test_for_tracefork, called via clone (). */
4220 linux_tracefork_grandchild (void *arg)
4225 #define STACK_SIZE 4096
4228 linux_tracefork_child (void *arg)
4230 ptrace (PTRACE_TRACEME, 0, 0, 0);
4231 kill (getpid (), SIGSTOP);
4233 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
4236 linux_tracefork_grandchild (NULL);
4238 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4241 __clone2 (linux_tracefork_grandchild, arg, STACK_SIZE,
4242 CLONE_VM | SIGCHLD, NULL);
4244 clone (linux_tracefork_grandchild, (char *) arg + STACK_SIZE,
4245 CLONE_VM | SIGCHLD, NULL);
4248 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4253 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
4254 sure that we can enable the option, and that it had the desired
4258 linux_test_for_tracefork (void)
4260 int child_pid, ret, status;
4262 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4263 char *stack = xmalloc (STACK_SIZE * 4);
4264 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4266 linux_supports_tracefork_flag = 0;
4268 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
4270 child_pid = fork ();
4272 linux_tracefork_child (NULL);
4274 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4276 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
4278 child_pid = __clone2 (linux_tracefork_child, stack, STACK_SIZE,
4279 CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
4280 #else /* !__ia64__ */
4281 child_pid = clone (linux_tracefork_child, stack + STACK_SIZE,
4282 CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
4283 #endif /* !__ia64__ */
4285 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4287 if (child_pid == -1)
4288 perror_with_name ("clone");
4290 ret = my_waitpid (child_pid, &status, 0);
4292 perror_with_name ("waitpid");
4293 else if (ret != child_pid)
4294 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret);
4295 if (! WIFSTOPPED (status))
4296 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status);
4298 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0,
4299 (PTRACE_ARG4_TYPE) PTRACE_O_TRACEFORK);
4302 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
4305 warning ("linux_test_for_tracefork: failed to kill child");
4309 ret = my_waitpid (child_pid, &status, 0);
4310 if (ret != child_pid)
4311 warning ("linux_test_for_tracefork: failed to wait for killed child");
4312 else if (!WIFSIGNALED (status))
4313 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
4314 "killed child", status);
4319 ret = ptrace (PTRACE_CONT, child_pid, 0, 0);
4321 warning ("linux_test_for_tracefork: failed to resume child");
4323 ret = my_waitpid (child_pid, &status, 0);
4325 if (ret == child_pid && WIFSTOPPED (status)
4326 && status >> 16 == PTRACE_EVENT_FORK)
4329 ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
4330 if (ret == 0 && second_pid != 0)
4334 linux_supports_tracefork_flag = 1;
4335 my_waitpid (second_pid, &second_status, 0);
4336 ret = ptrace (PTRACE_KILL, second_pid, 0, 0);
4338 warning ("linux_test_for_tracefork: failed to kill second child");
4339 my_waitpid (second_pid, &status, 0);
4343 warning ("linux_test_for_tracefork: unexpected result from waitpid "
4344 "(%d, status 0x%x)", ret, status);
4348 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
4350 warning ("linux_test_for_tracefork: failed to kill child");
4351 my_waitpid (child_pid, &status, 0);
4353 while (WIFSTOPPED (status));
4355 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4357 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4362 linux_look_up_symbols (void)
4364 #ifdef USE_THREAD_DB
4365 struct process_info *proc = current_process ();
4367 if (proc->private->thread_db != NULL)
4370 /* If the kernel supports tracing forks then it also supports tracing
4371 clones, and then we don't need to use the magic thread event breakpoint
4372 to learn about threads. */
4373 thread_db_init (!linux_supports_tracefork_flag);
4378 linux_request_interrupt (void)
4380 extern unsigned long signal_pid;
4382 if (!ptid_equal (cont_thread, null_ptid)
4383 && !ptid_equal (cont_thread, minus_one_ptid))
4385 struct lwp_info *lwp;
4388 lwp = get_thread_lwp (current_inferior);
4389 lwpid = lwpid_of (lwp);
4390 kill_lwp (lwpid, SIGINT);
4393 kill_lwp (signal_pid, SIGINT);
4396 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
4397 to debugger memory starting at MYADDR. */
4400 linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len)
4402 char filename[PATH_MAX];
4404 int pid = lwpid_of (get_thread_lwp (current_inferior));
4406 xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
4408 fd = open (filename, O_RDONLY);
4412 if (offset != (CORE_ADDR) 0
4413 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
4416 n = read (fd, myaddr, len);
4423 /* These breakpoint and watchpoint related wrapper functions simply
4424 pass on the function call if the target has registered a
4425 corresponding function. */
4428 linux_insert_point (char type, CORE_ADDR addr, int len)
4430 if (the_low_target.insert_point != NULL)
4431 return the_low_target.insert_point (type, addr, len);
4433 /* Unsupported (see target.h). */
4438 linux_remove_point (char type, CORE_ADDR addr, int len)
4440 if (the_low_target.remove_point != NULL)
4441 return the_low_target.remove_point (type, addr, len);
4443 /* Unsupported (see target.h). */
4448 linux_stopped_by_watchpoint (void)
4450 struct lwp_info *lwp = get_thread_lwp (current_inferior);
4452 return lwp->stopped_by_watchpoint;
4456 linux_stopped_data_address (void)
4458 struct lwp_info *lwp = get_thread_lwp (current_inferior);
4460 return lwp->stopped_data_address;
4463 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4464 #if defined(__mcoldfire__)
4465 /* These should really be defined in the kernel's ptrace.h header. */
4466 #define PT_TEXT_ADDR 49*4
4467 #define PT_DATA_ADDR 50*4
4468 #define PT_TEXT_END_ADDR 51*4
4470 #define PT_TEXT_ADDR 220
4471 #define PT_TEXT_END_ADDR 224
4472 #define PT_DATA_ADDR 228
4473 #elif defined(__TMS320C6X__)
4474 #define PT_TEXT_ADDR (0x10000*4)
4475 #define PT_DATA_ADDR (0x10004*4)
4476 #define PT_TEXT_END_ADDR (0x10008*4)
4479 /* Under uClinux, programs are loaded at non-zero offsets, which we need
4480 to tell gdb about. */
4483 linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p)
4485 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
4486 unsigned long text, text_end, data;
4487 int pid = lwpid_of (get_thread_lwp (current_inferior));
4491 text = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_ADDR, 0);
4492 text_end = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_END_ADDR, 0);
4493 data = ptrace (PTRACE_PEEKUSER, pid, (long)PT_DATA_ADDR, 0);
4497 /* Both text and data offsets produced at compile-time (and so
4498 used by gdb) are relative to the beginning of the program,
4499 with the data segment immediately following the text segment.
4500 However, the actual runtime layout in memory may put the data
4501 somewhere else, so when we send gdb a data base-address, we
4502 use the real data base address and subtract the compile-time
4503 data base-address from it (which is just the length of the
4504 text segment). BSS immediately follows data in both
4507 *data_p = data - (text_end - text);
4517 linux_qxfer_osdata (const char *annex,
4518 unsigned char *readbuf, unsigned const char *writebuf,
4519 CORE_ADDR offset, int len)
4521 return linux_common_xfer_osdata (annex, readbuf, offset, len);
4524 /* Convert a native/host siginfo object, into/from the siginfo in the
4525 layout of the inferiors' architecture. */
4528 siginfo_fixup (struct siginfo *siginfo, void *inf_siginfo, int direction)
4532 if (the_low_target.siginfo_fixup != NULL)
4533 done = the_low_target.siginfo_fixup (siginfo, inf_siginfo, direction);
4535 /* If there was no callback, or the callback didn't do anything,
4536 then just do a straight memcpy. */
4540 memcpy (siginfo, inf_siginfo, sizeof (struct siginfo));
4542 memcpy (inf_siginfo, siginfo, sizeof (struct siginfo));
4547 linux_xfer_siginfo (const char *annex, unsigned char *readbuf,
4548 unsigned const char *writebuf, CORE_ADDR offset, int len)
4551 struct siginfo siginfo;
4552 char inf_siginfo[sizeof (struct siginfo)];
4554 if (current_inferior == NULL)
4557 pid = lwpid_of (get_thread_lwp (current_inferior));
4560 fprintf (stderr, "%s siginfo for lwp %d.\n",
4561 readbuf != NULL ? "Reading" : "Writing",
4564 if (offset >= sizeof (siginfo))
4567 if (ptrace (PTRACE_GETSIGINFO, pid, 0, &siginfo) != 0)
4570 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
4571 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
4572 inferior with a 64-bit GDBSERVER should look the same as debugging it
4573 with a 32-bit GDBSERVER, we need to convert it. */
4574 siginfo_fixup (&siginfo, inf_siginfo, 0);
4576 if (offset + len > sizeof (siginfo))
4577 len = sizeof (siginfo) - offset;
4579 if (readbuf != NULL)
4580 memcpy (readbuf, inf_siginfo + offset, len);
4583 memcpy (inf_siginfo + offset, writebuf, len);
4585 /* Convert back to ptrace layout before flushing it out. */
4586 siginfo_fixup (&siginfo, inf_siginfo, 1);
4588 if (ptrace (PTRACE_SETSIGINFO, pid, 0, &siginfo) != 0)
4595 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4596 so we notice when children change state; as the handler for the
4597 sigsuspend in my_waitpid. */
4600 sigchld_handler (int signo)
4602 int old_errno = errno;
4608 /* fprintf is not async-signal-safe, so call write
4610 if (write (2, "sigchld_handler\n",
4611 sizeof ("sigchld_handler\n") - 1) < 0)
4612 break; /* just ignore */
4616 if (target_is_async_p ())
4617 async_file_mark (); /* trigger a linux_wait */
4623 linux_supports_non_stop (void)
4629 linux_async (int enable)
4631 int previous = (linux_event_pipe[0] != -1);
4634 fprintf (stderr, "linux_async (%d), previous=%d\n",
4637 if (previous != enable)
4640 sigemptyset (&mask);
4641 sigaddset (&mask, SIGCHLD);
4643 sigprocmask (SIG_BLOCK, &mask, NULL);
4647 if (pipe (linux_event_pipe) == -1)
4648 fatal ("creating event pipe failed.");
4650 fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK);
4651 fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK);
4653 /* Register the event loop handler. */
4654 add_file_handler (linux_event_pipe[0],
4655 handle_target_event, NULL);
4657 /* Always trigger a linux_wait. */
4662 delete_file_handler (linux_event_pipe[0]);
4664 close (linux_event_pipe[0]);
4665 close (linux_event_pipe[1]);
4666 linux_event_pipe[0] = -1;
4667 linux_event_pipe[1] = -1;
4670 sigprocmask (SIG_UNBLOCK, &mask, NULL);
4677 linux_start_non_stop (int nonstop)
4679 /* Register or unregister from event-loop accordingly. */
4680 linux_async (nonstop);
4685 linux_supports_multi_process (void)
4691 linux_supports_disable_randomization (void)
4693 #ifdef HAVE_PERSONALITY
4700 /* Enumerate spufs IDs for process PID. */
4702 spu_enumerate_spu_ids (long pid, unsigned char *buf, CORE_ADDR offset, int len)
4708 struct dirent *entry;
4710 sprintf (path, "/proc/%ld/fd", pid);
4711 dir = opendir (path);
4716 while ((entry = readdir (dir)) != NULL)
4722 fd = atoi (entry->d_name);
4726 sprintf (path, "/proc/%ld/fd/%d", pid, fd);
4727 if (stat (path, &st) != 0)
4729 if (!S_ISDIR (st.st_mode))
4732 if (statfs (path, &stfs) != 0)
4734 if (stfs.f_type != SPUFS_MAGIC)
4737 if (pos >= offset && pos + 4 <= offset + len)
4739 *(unsigned int *)(buf + pos - offset) = fd;
4749 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
4750 object type, using the /proc file system. */
4752 linux_qxfer_spu (const char *annex, unsigned char *readbuf,
4753 unsigned const char *writebuf,
4754 CORE_ADDR offset, int len)
4756 long pid = lwpid_of (get_thread_lwp (current_inferior));
4761 if (!writebuf && !readbuf)
4769 return spu_enumerate_spu_ids (pid, readbuf, offset, len);
4772 sprintf (buf, "/proc/%ld/fd/%s", pid, annex);
4773 fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
4778 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
4785 ret = write (fd, writebuf, (size_t) len);
4787 ret = read (fd, readbuf, (size_t) len);
4793 #if defined PT_GETDSBT || defined PTRACE_GETFDPIC
4794 struct target_loadseg
4796 /* Core address to which the segment is mapped. */
4798 /* VMA recorded in the program header. */
4800 /* Size of this segment in memory. */
4804 # if defined PT_GETDSBT
4805 struct target_loadmap
4807 /* Protocol version number, must be zero. */
4809 /* Pointer to the DSBT table, its size, and the DSBT index. */
4810 unsigned *dsbt_table;
4811 unsigned dsbt_size, dsbt_index;
4812 /* Number of segments in this map. */
4814 /* The actual memory map. */
4815 struct target_loadseg segs[/*nsegs*/];
4817 # define LINUX_LOADMAP PT_GETDSBT
4818 # define LINUX_LOADMAP_EXEC PTRACE_GETDSBT_EXEC
4819 # define LINUX_LOADMAP_INTERP PTRACE_GETDSBT_INTERP
4821 struct target_loadmap
4823 /* Protocol version number, must be zero. */
4825 /* Number of segments in this map. */
4827 /* The actual memory map. */
4828 struct target_loadseg segs[/*nsegs*/];
4830 # define LINUX_LOADMAP PTRACE_GETFDPIC
4831 # define LINUX_LOADMAP_EXEC PTRACE_GETFDPIC_EXEC
4832 # define LINUX_LOADMAP_INTERP PTRACE_GETFDPIC_INTERP
4836 linux_read_loadmap (const char *annex, CORE_ADDR offset,
4837 unsigned char *myaddr, unsigned int len)
4839 int pid = lwpid_of (get_thread_lwp (current_inferior));
4841 struct target_loadmap *data = NULL;
4842 unsigned int actual_length, copy_length;
4844 if (strcmp (annex, "exec") == 0)
4845 addr = (int) LINUX_LOADMAP_EXEC;
4846 else if (strcmp (annex, "interp") == 0)
4847 addr = (int) LINUX_LOADMAP_INTERP;
4851 if (ptrace (LINUX_LOADMAP, pid, addr, &data) != 0)
4857 actual_length = sizeof (struct target_loadmap)
4858 + sizeof (struct target_loadseg) * data->nsegs;
4860 if (offset < 0 || offset > actual_length)
4863 copy_length = actual_length - offset < len ? actual_length - offset : len;
4864 memcpy (myaddr, (char *) data + offset, copy_length);
4868 # define linux_read_loadmap NULL
4869 #endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */
4872 linux_process_qsupported (const char *query)
4874 if (the_low_target.process_qsupported != NULL)
4875 the_low_target.process_qsupported (query);
4879 linux_supports_tracepoints (void)
4881 if (*the_low_target.supports_tracepoints == NULL)
4884 return (*the_low_target.supports_tracepoints) ();
4888 linux_read_pc (struct regcache *regcache)
4890 if (the_low_target.get_pc == NULL)
4893 return (*the_low_target.get_pc) (regcache);
4897 linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
4899 gdb_assert (the_low_target.set_pc != NULL);
4901 (*the_low_target.set_pc) (regcache, pc);
4905 linux_thread_stopped (struct thread_info *thread)
4907 return get_thread_lwp (thread)->stopped;
4910 /* This exposes stop-all-threads functionality to other modules. */
4913 linux_pause_all (int freeze)
4915 stop_all_lwps (freeze, NULL);
4918 /* This exposes unstop-all-threads functionality to other gdbserver
4922 linux_unpause_all (int unfreeze)
4924 unstop_all_lwps (unfreeze, NULL);
4928 linux_prepare_to_access_memory (void)
4930 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
4933 linux_pause_all (1);
4938 linux_done_accessing_memory (void)
4940 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
4943 linux_unpause_all (1);
4947 linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr,
4948 CORE_ADDR collector,
4951 CORE_ADDR *jump_entry,
4952 CORE_ADDR *trampoline,
4953 ULONGEST *trampoline_size,
4954 unsigned char *jjump_pad_insn,
4955 ULONGEST *jjump_pad_insn_size,
4956 CORE_ADDR *adjusted_insn_addr,
4957 CORE_ADDR *adjusted_insn_addr_end,
4960 return (*the_low_target.install_fast_tracepoint_jump_pad)
4961 (tpoint, tpaddr, collector, lockaddr, orig_size,
4962 jump_entry, trampoline, trampoline_size,
4963 jjump_pad_insn, jjump_pad_insn_size,
4964 adjusted_insn_addr, adjusted_insn_addr_end,
4968 static struct emit_ops *
4969 linux_emit_ops (void)
4971 if (the_low_target.emit_ops != NULL)
4972 return (*the_low_target.emit_ops) ();
4978 linux_get_min_fast_tracepoint_insn_len (void)
4980 return (*the_low_target.get_min_fast_tracepoint_insn_len) ();
4983 /* Extract &phdr and num_phdr in the inferior. Return 0 on success. */
4986 get_phdr_phnum_from_proc_auxv (const int pid, const int is_elf64,
4987 CORE_ADDR *phdr_memaddr, int *num_phdr)
4989 char filename[PATH_MAX];
4991 const int auxv_size = is_elf64
4992 ? sizeof (Elf64_auxv_t) : sizeof (Elf32_auxv_t);
4993 char buf[sizeof (Elf64_auxv_t)]; /* The larger of the two. */
4995 xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
4997 fd = open (filename, O_RDONLY);
5003 while (read (fd, buf, auxv_size) == auxv_size
5004 && (*phdr_memaddr == 0 || *num_phdr == 0))
5008 Elf64_auxv_t *const aux = (Elf64_auxv_t *) buf;
5010 switch (aux->a_type)
5013 *phdr_memaddr = aux->a_un.a_val;
5016 *num_phdr = aux->a_un.a_val;
5022 Elf32_auxv_t *const aux = (Elf32_auxv_t *) buf;
5024 switch (aux->a_type)
5027 *phdr_memaddr = aux->a_un.a_val;
5030 *num_phdr = aux->a_un.a_val;
5038 if (*phdr_memaddr == 0 || *num_phdr == 0)
5040 warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: "
5041 "phdr_memaddr = %ld, phdr_num = %d",
5042 (long) *phdr_memaddr, *num_phdr);
5049 /* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */
5052 get_dynamic (const int pid, const int is_elf64)
5054 CORE_ADDR phdr_memaddr, relocation;
5056 unsigned char *phdr_buf;
5057 const int phdr_size = is_elf64 ? sizeof (Elf64_Phdr) : sizeof (Elf32_Phdr);
5059 if (get_phdr_phnum_from_proc_auxv (pid, is_elf64, &phdr_memaddr, &num_phdr))
5062 gdb_assert (num_phdr < 100); /* Basic sanity check. */
5063 phdr_buf = alloca (num_phdr * phdr_size);
5065 if (linux_read_memory (phdr_memaddr, phdr_buf, num_phdr * phdr_size))
5068 /* Compute relocation: it is expected to be 0 for "regular" executables,
5069 non-zero for PIE ones. */
5071 for (i = 0; relocation == -1 && i < num_phdr; i++)
5074 Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size);
5076 if (p->p_type == PT_PHDR)
5077 relocation = phdr_memaddr - p->p_vaddr;
5081 Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size);
5083 if (p->p_type == PT_PHDR)
5084 relocation = phdr_memaddr - p->p_vaddr;
5087 if (relocation == -1)
5089 warning ("Unexpected missing PT_PHDR");
5093 for (i = 0; i < num_phdr; i++)
5097 Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size);
5099 if (p->p_type == PT_DYNAMIC)
5100 return p->p_vaddr + relocation;
5104 Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size);
5106 if (p->p_type == PT_DYNAMIC)
5107 return p->p_vaddr + relocation;
5114 /* Return &_r_debug in the inferior, or -1 if not present. Return value
5115 can be 0 if the inferior does not yet have the library list initialized. */
5118 get_r_debug (const int pid, const int is_elf64)
5120 CORE_ADDR dynamic_memaddr;
5121 const int dyn_size = is_elf64 ? sizeof (Elf64_Dyn) : sizeof (Elf32_Dyn);
5122 unsigned char buf[sizeof (Elf64_Dyn)]; /* The larger of the two. */
5124 dynamic_memaddr = get_dynamic (pid, is_elf64);
5125 if (dynamic_memaddr == 0)
5126 return (CORE_ADDR) -1;
5128 while (linux_read_memory (dynamic_memaddr, buf, dyn_size) == 0)
5132 Elf64_Dyn *const dyn = (Elf64_Dyn *) buf;
5134 if (dyn->d_tag == DT_DEBUG)
5135 return dyn->d_un.d_val;
5137 if (dyn->d_tag == DT_NULL)
5142 Elf32_Dyn *const dyn = (Elf32_Dyn *) buf;
5144 if (dyn->d_tag == DT_DEBUG)
5145 return dyn->d_un.d_val;
5147 if (dyn->d_tag == DT_NULL)
5151 dynamic_memaddr += dyn_size;
5154 return (CORE_ADDR) -1;
5157 /* Read one pointer from MEMADDR in the inferior. */
5160 read_one_ptr (CORE_ADDR memaddr, CORE_ADDR *ptr, int ptr_size)
5163 return linux_read_memory (memaddr, (unsigned char *) ptr, ptr_size);
5166 struct link_map_offsets
5168 /* Offset and size of r_debug.r_version. */
5169 int r_version_offset;
5171 /* Offset and size of r_debug.r_map. */
5174 /* Offset to l_addr field in struct link_map. */
5177 /* Offset to l_name field in struct link_map. */
5180 /* Offset to l_ld field in struct link_map. */
5183 /* Offset to l_next field in struct link_map. */
5186 /* Offset to l_prev field in struct link_map. */
5190 /* Construct qXfer:libraries:read reply. */
5193 linux_qxfer_libraries_svr4 (const char *annex, unsigned char *readbuf,
5194 unsigned const char *writebuf,
5195 CORE_ADDR offset, int len)
5198 unsigned document_len;
5199 struct process_info_private *const priv = current_process ()->private;
5200 char filename[PATH_MAX];
5203 static const struct link_map_offsets lmo_32bit_offsets =
5205 0, /* r_version offset. */
5206 4, /* r_debug.r_map offset. */
5207 0, /* l_addr offset in link_map. */
5208 4, /* l_name offset in link_map. */
5209 8, /* l_ld offset in link_map. */
5210 12, /* l_next offset in link_map. */
5211 16 /* l_prev offset in link_map. */
5214 static const struct link_map_offsets lmo_64bit_offsets =
5216 0, /* r_version offset. */
5217 8, /* r_debug.r_map offset. */
5218 0, /* l_addr offset in link_map. */
5219 8, /* l_name offset in link_map. */
5220 16, /* l_ld offset in link_map. */
5221 24, /* l_next offset in link_map. */
5222 32 /* l_prev offset in link_map. */
5224 const struct link_map_offsets *lmo;
5226 if (writebuf != NULL)
5228 if (readbuf == NULL)
5231 pid = lwpid_of (get_thread_lwp (current_inferior));
5232 xsnprintf (filename, sizeof filename, "/proc/%d/exe", pid);
5233 is_elf64 = elf_64_file_p (filename);
5234 lmo = is_elf64 ? &lmo_64bit_offsets : &lmo_32bit_offsets;
5236 if (priv->r_debug == 0)
5237 priv->r_debug = get_r_debug (pid, is_elf64);
5239 if (priv->r_debug == (CORE_ADDR) -1 || priv->r_debug == 0)
5241 document = xstrdup ("<library-list-svr4 version=\"1.0\"/>\n");
5245 int allocated = 1024;
5247 const int ptr_size = is_elf64 ? 8 : 4;
5248 CORE_ADDR lm_addr, lm_prev, l_name, l_addr, l_ld, l_next, l_prev;
5249 int r_version, header_done = 0;
5251 document = xmalloc (allocated);
5252 strcpy (document, "<library-list-svr4 version=\"1.0\"");
5253 p = document + strlen (document);
5256 if (linux_read_memory (priv->r_debug + lmo->r_version_offset,
5257 (unsigned char *) &r_version,
5258 sizeof (r_version)) != 0
5261 warning ("unexpected r_debug version %d", r_version);
5265 if (read_one_ptr (priv->r_debug + lmo->r_map_offset,
5266 &lm_addr, ptr_size) != 0)
5268 warning ("unable to read r_map from 0x%lx",
5269 (long) priv->r_debug + lmo->r_map_offset);
5274 while (read_one_ptr (lm_addr + lmo->l_name_offset,
5275 &l_name, ptr_size) == 0
5276 && read_one_ptr (lm_addr + lmo->l_addr_offset,
5277 &l_addr, ptr_size) == 0
5278 && read_one_ptr (lm_addr + lmo->l_ld_offset,
5279 &l_ld, ptr_size) == 0
5280 && read_one_ptr (lm_addr + lmo->l_prev_offset,
5281 &l_prev, ptr_size) == 0
5282 && read_one_ptr (lm_addr + lmo->l_next_offset,
5283 &l_next, ptr_size) == 0)
5285 unsigned char libname[PATH_MAX];
5287 if (lm_prev != l_prev)
5289 warning ("Corrupted shared library list: 0x%lx != 0x%lx",
5290 (long) lm_prev, (long) l_prev);
5294 /* Not checking for error because reading may stop before
5295 we've got PATH_MAX worth of characters. */
5297 linux_read_memory (l_name, libname, sizeof (libname) - 1);
5298 libname[sizeof (libname) - 1] = '\0';
5299 if (libname[0] != '\0')
5301 /* 6x the size for xml_escape_text below. */
5302 size_t len = 6 * strlen ((char *) libname);
5307 /* Terminate `<library-list-svr4'. */
5312 while (allocated < p - document + len + 200)
5314 /* Expand to guarantee sufficient storage. */
5315 uintptr_t document_len = p - document;
5317 document = xrealloc (document, 2 * allocated);
5319 p = document + document_len;
5322 name = xml_escape_text ((char *) libname);
5323 p += sprintf (p, "<library name=\"%s\" lm=\"0x%lx\" "
5324 "l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>",
5325 name, (unsigned long) lm_addr,
5326 (unsigned long) l_addr, (unsigned long) l_ld);
5329 else if (lm_prev == 0)
5331 sprintf (p, " main-lm=\"0x%lx\"", (unsigned long) lm_addr);
5342 strcpy (p, "</library-list-svr4>");
5345 document_len = strlen (document);
5346 if (offset < document_len)
5347 document_len -= offset;
5350 if (len > document_len)
5353 memcpy (readbuf, document + offset, len);
5359 static struct target_ops linux_target_ops = {
5360 linux_create_inferior,
5369 linux_fetch_registers,
5370 linux_store_registers,
5371 linux_prepare_to_access_memory,
5372 linux_done_accessing_memory,
5375 linux_look_up_symbols,
5376 linux_request_interrupt,
5380 linux_stopped_by_watchpoint,
5381 linux_stopped_data_address,
5382 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
5387 #ifdef USE_THREAD_DB
5388 thread_db_get_tls_address,
5393 hostio_last_error_from_errno,
5396 linux_supports_non_stop,
5398 linux_start_non_stop,
5399 linux_supports_multi_process,
5400 #ifdef USE_THREAD_DB
5401 thread_db_handle_monitor_command,
5405 linux_common_core_of_thread,
5407 linux_process_qsupported,
5408 linux_supports_tracepoints,
5411 linux_thread_stopped,
5415 linux_cancel_breakpoints,
5416 linux_stabilize_threads,
5417 linux_install_fast_tracepoint_jump_pad,
5419 linux_supports_disable_randomization,
5420 linux_get_min_fast_tracepoint_insn_len,
5421 linux_qxfer_libraries_svr4,
5425 linux_init_signals ()
5427 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
5428 to find what the cancel signal actually is. */
5429 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
5430 signal (__SIGRTMIN+1, SIG_IGN);
5435 initialize_low (void)
5437 struct sigaction sigchld_action;
5438 memset (&sigchld_action, 0, sizeof (sigchld_action));
5439 set_target_ops (&linux_target_ops);
5440 set_breakpoint_data (the_low_target.breakpoint,
5441 the_low_target.breakpoint_len);
5442 linux_init_signals ();
5443 linux_test_for_tracefork ();
5444 #ifdef HAVE_LINUX_REGSETS
5445 for (num_regsets = 0; target_regsets[num_regsets].size >= 0; num_regsets++)
5447 disabled_regsets = xmalloc (num_regsets);
5450 sigchld_action.sa_handler = sigchld_handler;
5451 sigemptyset (&sigchld_action.sa_mask);
5452 sigchld_action.sa_flags = SA_RESTART;
5453 sigaction (SIGCHLD, &sigchld_action, NULL);