1 /* Low level interface to ptrace, for the remote server for GDB.
2 Copyright (C) 1995-2014 Free Software Foundation, Inc.
4 This file is part of GDB.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>. */
20 #include "linux-low.h"
21 #include "nat/linux-osdata.h"
24 #include "nat/linux-nat.h"
25 #include "nat/linux-waitpid.h"
27 #include <sys/ptrace.h>
28 #include "nat/linux-ptrace.h"
29 #include "nat/linux-procfs.h"
31 #include <sys/ioctl.h>
34 #include <sys/syscall.h>
38 #include <sys/types.h>
43 #include "filestuff.h"
44 #include "tracepoint.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
79 /* Some targets did not define these ptrace constants from the start,
80 so gdbserver defines them locally here. In the future, these may
81 be removed after they are added to asm/ptrace.h. */
82 #if !(defined(PT_TEXT_ADDR) \
83 || defined(PT_DATA_ADDR) \
84 || defined(PT_TEXT_END_ADDR))
85 #if defined(__mcoldfire__)
86 /* These are still undefined in 3.10 kernels. */
87 #define PT_TEXT_ADDR 49*4
88 #define PT_DATA_ADDR 50*4
89 #define PT_TEXT_END_ADDR 51*4
90 /* BFIN already defines these since at least 2.6.32 kernels. */
92 #define PT_TEXT_ADDR 220
93 #define PT_TEXT_END_ADDR 224
94 #define PT_DATA_ADDR 228
95 /* These are still undefined in 3.10 kernels. */
96 #elif defined(__TMS320C6X__)
97 #define PT_TEXT_ADDR (0x10000*4)
98 #define PT_DATA_ADDR (0x10004*4)
99 #define PT_TEXT_END_ADDR (0x10008*4)
103 #ifdef HAVE_LINUX_BTRACE
104 # include "nat/linux-btrace.h"
107 #ifndef HAVE_ELF32_AUXV_T
108 /* Copied from glibc's elf.h. */
111 uint32_t a_type; /* Entry type */
114 uint32_t a_val; /* Integer value */
115 /* We use to have pointer elements added here. We cannot do that,
116 though, since it does not work when using 32-bit definitions
117 on 64-bit platforms and vice versa. */
122 #ifndef HAVE_ELF64_AUXV_T
123 /* Copied from glibc's elf.h. */
126 uint64_t a_type; /* Entry type */
129 uint64_t a_val; /* Integer value */
130 /* We use to have pointer elements added here. We cannot do that,
131 though, since it does not work when using 32-bit definitions
132 on 64-bit platforms and vice versa. */
137 /* A list of all unknown processes which receive stop signals. Some
138 other process will presumably claim each of these as forked
139 children momentarily. */
141 struct simple_pid_list
143 /* The process ID. */
146 /* The status as reported by waitpid. */
150 struct simple_pid_list *next;
152 struct simple_pid_list *stopped_pids;
154 /* Trivial list manipulation functions to keep track of a list of new
155 stopped processes. */
158 add_to_pid_list (struct simple_pid_list **listp, int pid, int status)
160 struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list));
163 new_pid->status = status;
164 new_pid->next = *listp;
169 pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp)
171 struct simple_pid_list **p;
173 for (p = listp; *p != NULL; p = &(*p)->next)
174 if ((*p)->pid == pid)
176 struct simple_pid_list *next = (*p)->next;
178 *statusp = (*p)->status;
186 enum stopping_threads_kind
188 /* Not stopping threads presently. */
189 NOT_STOPPING_THREADS,
191 /* Stopping threads. */
194 /* Stopping and suspending threads. */
195 STOPPING_AND_SUSPENDING_THREADS
198 /* This is set while stop_all_lwps is in effect. */
199 enum stopping_threads_kind stopping_threads = NOT_STOPPING_THREADS;
201 /* FIXME make into a target method? */
202 int using_threads = 1;
204 /* True if we're presently stabilizing threads (moving them out of
206 static int stabilizing_threads;
208 static void linux_resume_one_lwp (struct lwp_info *lwp,
209 int step, int signal, siginfo_t *info);
210 static void linux_resume (struct thread_resume *resume_info, size_t n);
211 static void stop_all_lwps (int suspend, struct lwp_info *except);
212 static void unstop_all_lwps (int unsuspend, struct lwp_info *except);
213 static int linux_wait_for_event_filtered (ptid_t wait_ptid, ptid_t filter_ptid,
214 int *wstat, int options);
215 static int linux_wait_for_event (ptid_t ptid, int *wstat, int options);
216 static struct lwp_info *add_lwp (ptid_t ptid);
217 static int linux_stopped_by_watchpoint (void);
218 static void mark_lwp_dead (struct lwp_info *lwp, int wstat);
219 static void proceed_all_lwps (void);
220 static int finish_step_over (struct lwp_info *lwp);
221 static CORE_ADDR get_stop_pc (struct lwp_info *lwp);
222 static int kill_lwp (unsigned long lwpid, int signo);
224 /* True if the low target can hardware single-step. Such targets
225 don't need a BREAKPOINT_REINSERT_ADDR callback. */
228 can_hardware_single_step (void)
230 return (the_low_target.breakpoint_reinsert_addr == NULL);
233 /* True if the low target supports memory breakpoints. If so, we'll
234 have a GET_PC implementation. */
237 supports_breakpoints (void)
239 return (the_low_target.get_pc != NULL);
242 /* Returns true if this target can support fast tracepoints. This
243 does not mean that the in-process agent has been loaded in the
247 supports_fast_tracepoints (void)
249 return the_low_target.install_fast_tracepoint_jump_pad != NULL;
252 /* True if LWP is stopped in its stepping range. */
255 lwp_in_step_range (struct lwp_info *lwp)
257 CORE_ADDR pc = lwp->stop_pc;
259 return (pc >= lwp->step_range_start && pc < lwp->step_range_end);
262 struct pending_signals
266 struct pending_signals *prev;
269 /* The read/write ends of the pipe registered as waitable file in the
271 static int linux_event_pipe[2] = { -1, -1 };
273 /* True if we're currently in async mode. */
274 #define target_is_async_p() (linux_event_pipe[0] != -1)
276 static void send_sigstop (struct lwp_info *lwp);
277 static void wait_for_sigstop (void);
279 /* Return non-zero if HEADER is a 64-bit ELF file. */
282 elf_64_header_p (const Elf64_Ehdr *header, unsigned int *machine)
284 if (header->e_ident[EI_MAG0] == ELFMAG0
285 && header->e_ident[EI_MAG1] == ELFMAG1
286 && header->e_ident[EI_MAG2] == ELFMAG2
287 && header->e_ident[EI_MAG3] == ELFMAG3)
289 *machine = header->e_machine;
290 return header->e_ident[EI_CLASS] == ELFCLASS64;
297 /* Return non-zero if FILE is a 64-bit ELF file,
298 zero if the file is not a 64-bit ELF file,
299 and -1 if the file is not accessible or doesn't exist. */
302 elf_64_file_p (const char *file, unsigned int *machine)
307 fd = open (file, O_RDONLY);
311 if (read (fd, &header, sizeof (header)) != sizeof (header))
318 return elf_64_header_p (&header, machine);
321 /* Accepts an integer PID; Returns true if the executable PID is
322 running is a 64-bit ELF file.. */
325 linux_pid_exe_is_elf_64_file (int pid, unsigned int *machine)
329 sprintf (file, "/proc/%d/exe", pid);
330 return elf_64_file_p (file, machine);
334 delete_lwp (struct lwp_info *lwp)
336 struct thread_info *thr = get_lwp_thread (lwp);
339 debug_printf ("deleting %ld\n", lwpid_of (thr));
342 free (lwp->arch_private);
346 /* Add a process to the common process list, and set its private
349 static struct process_info *
350 linux_add_process (int pid, int attached)
352 struct process_info *proc;
354 proc = add_process (pid, attached);
355 proc->private = xcalloc (1, sizeof (*proc->private));
357 /* Set the arch when the first LWP stops. */
358 proc->private->new_inferior = 1;
360 if (the_low_target.new_process != NULL)
361 proc->private->arch_private = the_low_target.new_process ();
366 /* Handle a GNU/Linux extended wait response. If we see a clone
367 event, we need to add the new LWP to our list (and not report the
368 trap to higher layers). */
371 handle_extended_wait (struct lwp_info *event_child, int wstat)
373 int event = wstat >> 16;
374 struct thread_info *event_thr = get_lwp_thread (event_child);
375 struct lwp_info *new_lwp;
377 if (event == PTRACE_EVENT_CLONE)
380 unsigned long new_pid;
383 ptrace (PTRACE_GETEVENTMSG, lwpid_of (event_thr), (PTRACE_TYPE_ARG3) 0,
386 /* If we haven't already seen the new PID stop, wait for it now. */
387 if (!pull_pid_from_list (&stopped_pids, new_pid, &status))
389 /* The new child has a pending SIGSTOP. We can't affect it until it
390 hits the SIGSTOP, but we're already attached. */
392 ret = my_waitpid (new_pid, &status, __WALL);
395 perror_with_name ("waiting for new child");
396 else if (ret != new_pid)
397 warning ("wait returned unexpected PID %d", ret);
398 else if (!WIFSTOPPED (status))
399 warning ("wait returned unexpected status 0x%x", status);
403 debug_printf ("HEW: Got clone event "
404 "from LWP %ld, new child is LWP %ld\n",
405 lwpid_of (event_thr), new_pid);
407 ptid = ptid_build (pid_of (event_thr), new_pid, 0);
408 new_lwp = add_lwp (ptid);
410 /* Either we're going to immediately resume the new thread
411 or leave it stopped. linux_resume_one_lwp is a nop if it
412 thinks the thread is currently running, so set this first
413 before calling linux_resume_one_lwp. */
414 new_lwp->stopped = 1;
416 /* If we're suspending all threads, leave this one suspended
418 if (stopping_threads == STOPPING_AND_SUSPENDING_THREADS)
419 new_lwp->suspended = 1;
421 /* Normally we will get the pending SIGSTOP. But in some cases
422 we might get another signal delivered to the group first.
423 If we do get another signal, be sure not to lose it. */
424 if (WSTOPSIG (status) == SIGSTOP)
426 if (stopping_threads != NOT_STOPPING_THREADS)
427 new_lwp->stop_pc = get_stop_pc (new_lwp);
429 linux_resume_one_lwp (new_lwp, 0, 0, NULL);
433 new_lwp->stop_expected = 1;
435 if (stopping_threads != NOT_STOPPING_THREADS)
437 new_lwp->stop_pc = get_stop_pc (new_lwp);
438 new_lwp->status_pending_p = 1;
439 new_lwp->status_pending = status;
442 /* Pass the signal on. This is what GDB does - except
443 shouldn't we really report it instead? */
444 linux_resume_one_lwp (new_lwp, 0, WSTOPSIG (status), NULL);
447 /* Always resume the current thread. If we are stopping
448 threads, it will have a pending SIGSTOP; we may as well
450 linux_resume_one_lwp (event_child, event_child->stepping, 0, NULL);
454 /* Return the PC as read from the regcache of LWP, without any
458 get_pc (struct lwp_info *lwp)
460 struct thread_info *saved_thread;
461 struct regcache *regcache;
464 if (the_low_target.get_pc == NULL)
467 saved_thread = current_thread;
468 current_thread = get_lwp_thread (lwp);
470 regcache = get_thread_regcache (current_thread, 1);
471 pc = (*the_low_target.get_pc) (regcache);
474 debug_printf ("pc is 0x%lx\n", (long) pc);
476 current_thread = saved_thread;
480 /* This function should only be called if LWP got a SIGTRAP.
481 The SIGTRAP could mean several things.
483 On i386, where decr_pc_after_break is non-zero:
484 If we were single-stepping this process using PTRACE_SINGLESTEP,
485 we will get only the one SIGTRAP (even if the instruction we
486 stepped over was a breakpoint). The value of $eip will be the
488 If we continue the process using PTRACE_CONT, we will get a
489 SIGTRAP when we hit a breakpoint. The value of $eip will be
490 the instruction after the breakpoint (i.e. needs to be
491 decremented). If we report the SIGTRAP to GDB, we must also
492 report the undecremented PC. If we cancel the SIGTRAP, we
493 must resume at the decremented PC.
495 (Presumably, not yet tested) On a non-decr_pc_after_break machine
496 with hardware or kernel single-step:
497 If we single-step over a breakpoint instruction, our PC will
498 point at the following instruction. If we continue and hit a
499 breakpoint instruction, our PC will point at the breakpoint
503 get_stop_pc (struct lwp_info *lwp)
507 if (the_low_target.get_pc == NULL)
510 stop_pc = get_pc (lwp);
512 if (WSTOPSIG (lwp->last_status) == SIGTRAP
514 && !lwp->stopped_by_watchpoint
515 && lwp->last_status >> 16 == 0)
516 stop_pc -= the_low_target.decr_pc_after_break;
519 debug_printf ("stop pc is 0x%lx\n", (long) stop_pc);
524 static struct lwp_info *
525 add_lwp (ptid_t ptid)
527 struct lwp_info *lwp;
529 lwp = (struct lwp_info *) xmalloc (sizeof (*lwp));
530 memset (lwp, 0, sizeof (*lwp));
532 if (the_low_target.new_thread != NULL)
533 lwp->arch_private = the_low_target.new_thread ();
535 lwp->thread = add_thread (ptid, lwp);
540 /* Start an inferior process and returns its pid.
541 ALLARGS is a vector of program-name and args. */
544 linux_create_inferior (char *program, char **allargs)
546 #ifdef HAVE_PERSONALITY
547 int personality_orig = 0, personality_set = 0;
549 struct lwp_info *new_lwp;
553 #ifdef HAVE_PERSONALITY
554 if (disable_randomization)
557 personality_orig = personality (0xffffffff);
558 if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE))
561 personality (personality_orig | ADDR_NO_RANDOMIZE);
563 if (errno != 0 || (personality_set
564 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE)))
565 warning ("Error disabling address space randomization: %s",
570 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
576 perror_with_name ("fork");
581 ptrace (PTRACE_TRACEME, 0, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0);
583 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
584 signal (__SIGRTMIN + 1, SIG_DFL);
589 /* If gdbserver is connected to gdb via stdio, redirect the inferior's
590 stdout to stderr so that inferior i/o doesn't corrupt the connection.
591 Also, redirect stdin to /dev/null. */
592 if (remote_connection_is_stdio ())
595 open ("/dev/null", O_RDONLY);
597 if (write (2, "stdin/stdout redirected\n",
598 sizeof ("stdin/stdout redirected\n") - 1) < 0)
600 /* Errors ignored. */;
604 execv (program, allargs);
606 execvp (program, allargs);
608 fprintf (stderr, "Cannot exec %s: %s.\n", program,
614 #ifdef HAVE_PERSONALITY
618 personality (personality_orig);
620 warning ("Error restoring address space randomization: %s",
625 linux_add_process (pid, 0);
627 ptid = ptid_build (pid, pid, 0);
628 new_lwp = add_lwp (ptid);
629 new_lwp->must_set_ptrace_flags = 1;
635 linux_attach_fail_reason_string (ptid_t ptid, int err)
637 static char *reason_string;
638 struct buffer buffer;
640 long lwpid = ptid_get_lwp (ptid);
642 xfree (reason_string);
644 buffer_init (&buffer);
645 linux_ptrace_attach_fail_reason (lwpid, &buffer);
646 buffer_grow_str0 (&buffer, "");
647 warnings = buffer_finish (&buffer);
648 if (warnings[0] != '\0')
649 reason_string = xstrprintf ("%s (%d), %s",
650 strerror (err), err, warnings);
652 reason_string = xstrprintf ("%s (%d)",
653 strerror (err), err);
655 return reason_string;
658 /* Attach to an inferior process. */
661 linux_attach_lwp (ptid_t ptid)
663 struct lwp_info *new_lwp;
664 int lwpid = ptid_get_lwp (ptid);
666 if (ptrace (PTRACE_ATTACH, lwpid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0)
670 new_lwp = add_lwp (ptid);
672 /* We need to wait for SIGSTOP before being able to make the next
673 ptrace call on this LWP. */
674 new_lwp->must_set_ptrace_flags = 1;
676 if (linux_proc_pid_is_stopped (lwpid))
679 debug_printf ("Attached to a stopped process\n");
681 /* The process is definitely stopped. It is in a job control
682 stop, unless the kernel predates the TASK_STOPPED /
683 TASK_TRACED distinction, in which case it might be in a
684 ptrace stop. Make sure it is in a ptrace stop; from there we
685 can kill it, signal it, et cetera.
687 First make sure there is a pending SIGSTOP. Since we are
688 already attached, the process can not transition from stopped
689 to running without a PTRACE_CONT; so we know this signal will
690 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
691 probably already in the queue (unless this kernel is old
692 enough to use TASK_STOPPED for ptrace stops); but since
693 SIGSTOP is not an RT signal, it can only be queued once. */
694 kill_lwp (lwpid, SIGSTOP);
696 /* Finally, resume the stopped process. This will deliver the
697 SIGSTOP (or a higher priority signal, just like normal
698 PTRACE_ATTACH), which we'll catch later on. */
699 ptrace (PTRACE_CONT, lwpid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0);
702 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
705 There are several cases to consider here:
707 1) gdbserver has already attached to the process and is being notified
708 of a new thread that is being created.
709 In this case we should ignore that SIGSTOP and resume the
710 process. This is handled below by setting stop_expected = 1,
711 and the fact that add_thread sets last_resume_kind ==
714 2) This is the first thread (the process thread), and we're attaching
715 to it via attach_inferior.
716 In this case we want the process thread to stop.
717 This is handled by having linux_attach set last_resume_kind ==
718 resume_stop after we return.
720 If the pid we are attaching to is also the tgid, we attach to and
721 stop all the existing threads. Otherwise, we attach to pid and
722 ignore any other threads in the same group as this pid.
724 3) GDB is connecting to gdbserver and is requesting an enumeration of all
726 In this case we want the thread to stop.
727 FIXME: This case is currently not properly handled.
728 We should wait for the SIGSTOP but don't. Things work apparently
729 because enough time passes between when we ptrace (ATTACH) and when
730 gdb makes the next ptrace call on the thread.
732 On the other hand, if we are currently trying to stop all threads, we
733 should treat the new thread as if we had sent it a SIGSTOP. This works
734 because we are guaranteed that the add_lwp call above added us to the
735 end of the list, and so the new thread has not yet reached
736 wait_for_sigstop (but will). */
737 new_lwp->stop_expected = 1;
742 /* Attach to PID. If PID is the tgid, attach to it and all
746 linux_attach (unsigned long pid)
748 ptid_t ptid = ptid_build (pid, pid, 0);
751 /* Attach to PID. We will check for other threads
753 err = linux_attach_lwp (ptid);
755 error ("Cannot attach to process %ld: %s",
756 pid, linux_attach_fail_reason_string (ptid, err));
758 linux_add_process (pid, 1);
762 struct thread_info *thread;
764 /* Don't ignore the initial SIGSTOP if we just attached to this
765 process. It will be collected by wait shortly. */
766 thread = find_thread_ptid (ptid_build (pid, pid, 0));
767 thread->last_resume_kind = resume_stop;
770 if (linux_proc_get_tgid (pid) == pid)
775 sprintf (pathname, "/proc/%ld/task", pid);
777 dir = opendir (pathname);
781 fprintf (stderr, "Could not open /proc/%ld/task.\n", pid);
786 /* At this point we attached to the tgid. Scan the task for
788 int new_threads_found;
791 while (iterations < 2)
795 new_threads_found = 0;
796 /* Add all the other threads. While we go through the
797 threads, new threads may be spawned. Cycle through
798 the list of threads until we have done two iterations without
799 finding new threads. */
800 while ((dp = readdir (dir)) != NULL)
806 lwp = strtoul (dp->d_name, NULL, 10);
808 ptid = ptid_build (pid, lwp, 0);
810 /* Is this a new thread? */
811 if (lwp != 0 && find_thread_ptid (ptid) == NULL)
816 debug_printf ("Found new lwp %ld\n", lwp);
818 err = linux_attach_lwp (ptid);
820 warning ("Cannot attach to lwp %ld: %s",
822 linux_attach_fail_reason_string (ptid, err));
828 if (!new_threads_found)
849 second_thread_of_pid_p (struct inferior_list_entry *entry, void *args)
851 struct counter *counter = args;
853 if (ptid_get_pid (entry->id) == counter->pid)
855 if (++counter->count > 1)
863 last_thread_of_process_p (int pid)
865 struct counter counter = { pid , 0 };
867 return (find_inferior (&all_threads,
868 second_thread_of_pid_p, &counter) == NULL);
874 linux_kill_one_lwp (struct lwp_info *lwp)
876 struct thread_info *thr = get_lwp_thread (lwp);
877 int pid = lwpid_of (thr);
879 /* PTRACE_KILL is unreliable. After stepping into a signal handler,
880 there is no signal context, and ptrace(PTRACE_KILL) (or
881 ptrace(PTRACE_CONT, SIGKILL), pretty much the same) acts like
882 ptrace(CONT, pid, 0,0) and just resumes the tracee. A better
883 alternative is to kill with SIGKILL. We only need one SIGKILL
884 per process, not one for each thread. But since we still support
885 linuxthreads, and we also support debugging programs using raw
886 clone without CLONE_THREAD, we send one for each thread. For
887 years, we used PTRACE_KILL only, so we're being a bit paranoid
888 about some old kernels where PTRACE_KILL might work better
889 (dubious if there are any such, but that's why it's paranoia), so
890 we try SIGKILL first, PTRACE_KILL second, and so we're fine
894 kill_lwp (pid, SIGKILL);
897 int save_errno = errno;
899 debug_printf ("LKL: kill_lwp (SIGKILL) %s, 0, 0 (%s)\n",
900 target_pid_to_str (ptid_of (thr)),
901 save_errno ? strerror (save_errno) : "OK");
905 ptrace (PTRACE_KILL, pid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0);
908 int save_errno = errno;
910 debug_printf ("LKL: PTRACE_KILL %s, 0, 0 (%s)\n",
911 target_pid_to_str (ptid_of (thr)),
912 save_errno ? strerror (save_errno) : "OK");
916 /* Kill LWP and wait for it to die. */
919 kill_wait_lwp (struct lwp_info *lwp)
921 struct thread_info *thr = get_lwp_thread (lwp);
922 int pid = ptid_get_pid (ptid_of (thr));
923 int lwpid = ptid_get_lwp (ptid_of (thr));
928 debug_printf ("kwl: killing lwp %d, for pid: %d\n", lwpid, pid);
932 linux_kill_one_lwp (lwp);
934 /* Make sure it died. Notes:
936 - The loop is most likely unnecessary.
938 - We don't use linux_wait_for_event as that could delete lwps
939 while we're iterating over them. We're not interested in
940 any pending status at this point, only in making sure all
941 wait status on the kernel side are collected until the
944 - We don't use __WALL here as the __WALL emulation relies on
945 SIGCHLD, and killing a stopped process doesn't generate
946 one, nor an exit status.
948 res = my_waitpid (lwpid, &wstat, 0);
949 if (res == -1 && errno == ECHILD)
950 res = my_waitpid (lwpid, &wstat, __WCLONE);
951 } while (res > 0 && WIFSTOPPED (wstat));
953 gdb_assert (res > 0);
956 /* Callback for `find_inferior'. Kills an lwp of a given process,
957 except the leader. */
960 kill_one_lwp_callback (struct inferior_list_entry *entry, void *args)
962 struct thread_info *thread = (struct thread_info *) entry;
963 struct lwp_info *lwp = get_thread_lwp (thread);
964 int pid = * (int *) args;
966 if (ptid_get_pid (entry->id) != pid)
969 /* We avoid killing the first thread here, because of a Linux kernel (at
970 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
971 the children get a chance to be reaped, it will remain a zombie
974 if (lwpid_of (thread) == pid)
977 debug_printf ("lkop: is last of process %s\n",
978 target_pid_to_str (entry->id));
989 struct process_info *process;
990 struct lwp_info *lwp;
992 process = find_process_pid (pid);
996 /* If we're killing a running inferior, make sure it is stopped
997 first, as PTRACE_KILL will not work otherwise. */
998 stop_all_lwps (0, NULL);
1000 find_inferior (&all_threads, kill_one_lwp_callback , &pid);
1002 /* See the comment in linux_kill_one_lwp. We did not kill the first
1003 thread in the list, so do so now. */
1004 lwp = find_lwp_pid (pid_to_ptid (pid));
1009 debug_printf ("lk_1: cannot find lwp for pid: %d\n",
1013 kill_wait_lwp (lwp);
1015 the_target->mourn (process);
1017 /* Since we presently can only stop all lwps of all processes, we
1018 need to unstop lwps of other processes. */
1019 unstop_all_lwps (0, NULL);
1023 /* Get pending signal of THREAD, for detaching purposes. This is the
1024 signal the thread last stopped for, which we need to deliver to the
1025 thread when detaching, otherwise, it'd be suppressed/lost. */
1028 get_detach_signal (struct thread_info *thread)
1030 enum gdb_signal signo = GDB_SIGNAL_0;
1032 struct lwp_info *lp = get_thread_lwp (thread);
1034 if (lp->status_pending_p)
1035 status = lp->status_pending;
1038 /* If the thread had been suspended by gdbserver, and it stopped
1039 cleanly, then it'll have stopped with SIGSTOP. But we don't
1040 want to deliver that SIGSTOP. */
1041 if (thread->last_status.kind != TARGET_WAITKIND_STOPPED
1042 || thread->last_status.value.sig == GDB_SIGNAL_0)
1045 /* Otherwise, we may need to deliver the signal we
1047 status = lp->last_status;
1050 if (!WIFSTOPPED (status))
1053 debug_printf ("GPS: lwp %s hasn't stopped: no pending signal\n",
1054 target_pid_to_str (ptid_of (thread)));
1058 /* Extended wait statuses aren't real SIGTRAPs. */
1059 if (WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
1062 debug_printf ("GPS: lwp %s had stopped with extended "
1063 "status: no pending signal\n",
1064 target_pid_to_str (ptid_of (thread)));
1068 signo = gdb_signal_from_host (WSTOPSIG (status));
1070 if (program_signals_p && !program_signals[signo])
1073 debug_printf ("GPS: lwp %s had signal %s, but it is in nopass state\n",
1074 target_pid_to_str (ptid_of (thread)),
1075 gdb_signal_to_string (signo));
1078 else if (!program_signals_p
1079 /* If we have no way to know which signals GDB does not
1080 want to have passed to the program, assume
1081 SIGTRAP/SIGINT, which is GDB's default. */
1082 && (signo == GDB_SIGNAL_TRAP || signo == GDB_SIGNAL_INT))
1085 debug_printf ("GPS: lwp %s had signal %s, "
1086 "but we don't know if we should pass it. "
1087 "Default to not.\n",
1088 target_pid_to_str (ptid_of (thread)),
1089 gdb_signal_to_string (signo));
1095 debug_printf ("GPS: lwp %s has pending signal %s: delivering it.\n",
1096 target_pid_to_str (ptid_of (thread)),
1097 gdb_signal_to_string (signo));
1099 return WSTOPSIG (status);
1104 linux_detach_one_lwp (struct inferior_list_entry *entry, void *args)
1106 struct thread_info *thread = (struct thread_info *) entry;
1107 struct lwp_info *lwp = get_thread_lwp (thread);
1108 int pid = * (int *) args;
1111 if (ptid_get_pid (entry->id) != pid)
1114 /* If there is a pending SIGSTOP, get rid of it. */
1115 if (lwp->stop_expected)
1118 debug_printf ("Sending SIGCONT to %s\n",
1119 target_pid_to_str (ptid_of (thread)));
1121 kill_lwp (lwpid_of (thread), SIGCONT);
1122 lwp->stop_expected = 0;
1125 /* Flush any pending changes to the process's registers. */
1126 regcache_invalidate_thread (thread);
1128 /* Pass on any pending signal for this thread. */
1129 sig = get_detach_signal (thread);
1131 /* Finally, let it resume. */
1132 if (the_low_target.prepare_to_resume != NULL)
1133 the_low_target.prepare_to_resume (lwp);
1134 if (ptrace (PTRACE_DETACH, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0,
1135 (PTRACE_TYPE_ARG4) (long) sig) < 0)
1136 error (_("Can't detach %s: %s"),
1137 target_pid_to_str (ptid_of (thread)),
1145 linux_detach (int pid)
1147 struct process_info *process;
1149 process = find_process_pid (pid);
1150 if (process == NULL)
1153 /* Stop all threads before detaching. First, ptrace requires that
1154 the thread is stopped to sucessfully detach. Second, thread_db
1155 may need to uninstall thread event breakpoints from memory, which
1156 only works with a stopped process anyway. */
1157 stop_all_lwps (0, NULL);
1159 #ifdef USE_THREAD_DB
1160 thread_db_detach (process);
1163 /* Stabilize threads (move out of jump pads). */
1164 stabilize_threads ();
1166 find_inferior (&all_threads, linux_detach_one_lwp, &pid);
1168 the_target->mourn (process);
1170 /* Since we presently can only stop all lwps of all processes, we
1171 need to unstop lwps of other processes. */
1172 unstop_all_lwps (0, NULL);
1176 /* Remove all LWPs that belong to process PROC from the lwp list. */
1179 delete_lwp_callback (struct inferior_list_entry *entry, void *proc)
1181 struct thread_info *thread = (struct thread_info *) entry;
1182 struct lwp_info *lwp = get_thread_lwp (thread);
1183 struct process_info *process = proc;
1185 if (pid_of (thread) == pid_of (process))
1192 linux_mourn (struct process_info *process)
1194 struct process_info_private *priv;
1196 #ifdef USE_THREAD_DB
1197 thread_db_mourn (process);
1200 find_inferior (&all_threads, delete_lwp_callback, process);
1202 /* Freeing all private data. */
1203 priv = process->private;
1204 free (priv->arch_private);
1206 process->private = NULL;
1208 remove_process (process);
1212 linux_join (int pid)
1217 ret = my_waitpid (pid, &status, 0);
1218 if (WIFEXITED (status) || WIFSIGNALED (status))
1220 } while (ret != -1 || errno != ECHILD);
1223 /* Return nonzero if the given thread is still alive. */
1225 linux_thread_alive (ptid_t ptid)
1227 struct lwp_info *lwp = find_lwp_pid (ptid);
1229 /* We assume we always know if a thread exits. If a whole process
1230 exited but we still haven't been able to report it to GDB, we'll
1231 hold on to the last lwp of the dead process. */
1238 /* Return 1 if this lwp has an interesting status pending. */
1240 status_pending_p_callback (struct inferior_list_entry *entry, void *arg)
1242 struct thread_info *thread = (struct thread_info *) entry;
1243 struct lwp_info *lwp = get_thread_lwp (thread);
1244 ptid_t ptid = * (ptid_t *) arg;
1246 /* Check if we're only interested in events from a specific process
1248 if (!ptid_equal (minus_one_ptid, ptid)
1249 && ptid_get_pid (ptid) != ptid_get_pid (thread->entry.id))
1252 /* If we got a `vCont;t', but we haven't reported a stop yet, do
1253 report any status pending the LWP may have. */
1254 if (thread->last_resume_kind == resume_stop
1255 && thread->last_status.kind != TARGET_WAITKIND_IGNORE)
1258 return lwp->status_pending_p;
1262 same_lwp (struct inferior_list_entry *entry, void *data)
1264 ptid_t ptid = *(ptid_t *) data;
1267 if (ptid_get_lwp (ptid) != 0)
1268 lwp = ptid_get_lwp (ptid);
1270 lwp = ptid_get_pid (ptid);
1272 if (ptid_get_lwp (entry->id) == lwp)
1279 find_lwp_pid (ptid_t ptid)
1281 struct inferior_list_entry *thread
1282 = find_inferior (&all_threads, same_lwp, &ptid);
1287 return get_thread_lwp ((struct thread_info *) thread);
1290 /* Return the number of known LWPs in the tgid given by PID. */
1295 struct inferior_list_entry *inf, *tmp;
1298 ALL_INFERIORS (&all_threads, inf, tmp)
1300 if (ptid_get_pid (inf->id) == pid)
1307 /* Detect zombie thread group leaders, and "exit" them. We can't reap
1308 their exits until all other threads in the group have exited. */
1311 check_zombie_leaders (void)
1313 struct process_info *proc, *tmp;
1315 ALL_PROCESSES (proc, tmp)
1317 pid_t leader_pid = pid_of (proc);
1318 struct lwp_info *leader_lp;
1320 leader_lp = find_lwp_pid (pid_to_ptid (leader_pid));
1323 debug_printf ("leader_pid=%d, leader_lp!=NULL=%d, "
1324 "num_lwps=%d, zombie=%d\n",
1325 leader_pid, leader_lp!= NULL, num_lwps (leader_pid),
1326 linux_proc_pid_is_zombie (leader_pid));
1328 if (leader_lp != NULL
1329 /* Check if there are other threads in the group, as we may
1330 have raced with the inferior simply exiting. */
1331 && !last_thread_of_process_p (leader_pid)
1332 && linux_proc_pid_is_zombie (leader_pid))
1334 /* A leader zombie can mean one of two things:
1336 - It exited, and there's an exit status pending
1337 available, or only the leader exited (not the whole
1338 program). In the latter case, we can't waitpid the
1339 leader's exit status until all other threads are gone.
1341 - There are 3 or more threads in the group, and a thread
1342 other than the leader exec'd. On an exec, the Linux
1343 kernel destroys all other threads (except the execing
1344 one) in the thread group, and resets the execing thread's
1345 tid to the tgid. No exit notification is sent for the
1346 execing thread -- from the ptracer's perspective, it
1347 appears as though the execing thread just vanishes.
1348 Until we reap all other threads except the leader and the
1349 execing thread, the leader will be zombie, and the
1350 execing thread will be in `D (disc sleep)'. As soon as
1351 all other threads are reaped, the execing thread changes
1352 it's tid to the tgid, and the previous (zombie) leader
1353 vanishes, giving place to the "new" leader. We could try
1354 distinguishing the exit and exec cases, by waiting once
1355 more, and seeing if something comes out, but it doesn't
1356 sound useful. The previous leader _does_ go away, and
1357 we'll re-add the new one once we see the exec event
1358 (which is just the same as what would happen if the
1359 previous leader did exit voluntarily before some other
1364 "CZL: Thread group leader %d zombie "
1365 "(it exited, or another thread execd).\n",
1368 delete_lwp (leader_lp);
1373 /* Callback for `find_inferior'. Returns the first LWP that is not
1374 stopped. ARG is a PTID filter. */
1377 not_stopped_callback (struct inferior_list_entry *entry, void *arg)
1379 struct thread_info *thr = (struct thread_info *) entry;
1380 struct lwp_info *lwp;
1381 ptid_t filter = *(ptid_t *) arg;
1383 if (!ptid_match (ptid_of (thr), filter))
1386 lwp = get_thread_lwp (thr);
1393 /* This function should only be called if the LWP got a SIGTRAP.
1395 Handle any tracepoint steps or hits. Return true if a tracepoint
1396 event was handled, 0 otherwise. */
1399 handle_tracepoints (struct lwp_info *lwp)
1401 struct thread_info *tinfo = get_lwp_thread (lwp);
1402 int tpoint_related_event = 0;
1404 /* If this tracepoint hit causes a tracing stop, we'll immediately
1405 uninsert tracepoints. To do this, we temporarily pause all
1406 threads, unpatch away, and then unpause threads. We need to make
1407 sure the unpausing doesn't resume LWP too. */
1410 /* And we need to be sure that any all-threads-stopping doesn't try
1411 to move threads out of the jump pads, as it could deadlock the
1412 inferior (LWP could be in the jump pad, maybe even holding the
1415 /* Do any necessary step collect actions. */
1416 tpoint_related_event |= tracepoint_finished_step (tinfo, lwp->stop_pc);
1418 tpoint_related_event |= handle_tracepoint_bkpts (tinfo, lwp->stop_pc);
1420 /* See if we just hit a tracepoint and do its main collect
1422 tpoint_related_event |= tracepoint_was_hit (tinfo, lwp->stop_pc);
1426 gdb_assert (lwp->suspended == 0);
1427 gdb_assert (!stabilizing_threads || lwp->collecting_fast_tracepoint);
1429 if (tpoint_related_event)
1432 debug_printf ("got a tracepoint event\n");
1439 /* Convenience wrapper. Returns true if LWP is presently collecting a
1443 linux_fast_tracepoint_collecting (struct lwp_info *lwp,
1444 struct fast_tpoint_collect_status *status)
1446 CORE_ADDR thread_area;
1447 struct thread_info *thread = get_lwp_thread (lwp);
1449 if (the_low_target.get_thread_area == NULL)
1452 /* Get the thread area address. This is used to recognize which
1453 thread is which when tracing with the in-process agent library.
1454 We don't read anything from the address, and treat it as opaque;
1455 it's the address itself that we assume is unique per-thread. */
1456 if ((*the_low_target.get_thread_area) (lwpid_of (thread), &thread_area) == -1)
1459 return fast_tracepoint_collecting (thread_area, lwp->stop_pc, status);
1462 /* The reason we resume in the caller, is because we want to be able
1463 to pass lwp->status_pending as WSTAT, and we need to clear
1464 status_pending_p before resuming, otherwise, linux_resume_one_lwp
1465 refuses to resume. */
1468 maybe_move_out_of_jump_pad (struct lwp_info *lwp, int *wstat)
1470 struct thread_info *saved_thread;
1472 saved_thread = current_thread;
1473 current_thread = get_lwp_thread (lwp);
1476 || (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) != SIGTRAP))
1477 && supports_fast_tracepoints ()
1478 && agent_loaded_p ())
1480 struct fast_tpoint_collect_status status;
1484 debug_printf ("Checking whether LWP %ld needs to move out of the "
1486 lwpid_of (current_thread));
1488 r = linux_fast_tracepoint_collecting (lwp, &status);
1491 || (WSTOPSIG (*wstat) != SIGILL
1492 && WSTOPSIG (*wstat) != SIGFPE
1493 && WSTOPSIG (*wstat) != SIGSEGV
1494 && WSTOPSIG (*wstat) != SIGBUS))
1496 lwp->collecting_fast_tracepoint = r;
1500 if (r == 1 && lwp->exit_jump_pad_bkpt == NULL)
1502 /* Haven't executed the original instruction yet.
1503 Set breakpoint there, and wait till it's hit,
1504 then single-step until exiting the jump pad. */
1505 lwp->exit_jump_pad_bkpt
1506 = set_breakpoint_at (status.adjusted_insn_addr, NULL);
1510 debug_printf ("Checking whether LWP %ld needs to move out of "
1511 "the jump pad...it does\n",
1512 lwpid_of (current_thread));
1513 current_thread = saved_thread;
1520 /* If we get a synchronous signal while collecting, *and*
1521 while executing the (relocated) original instruction,
1522 reset the PC to point at the tpoint address, before
1523 reporting to GDB. Otherwise, it's an IPA lib bug: just
1524 report the signal to GDB, and pray for the best. */
1526 lwp->collecting_fast_tracepoint = 0;
1529 && (status.adjusted_insn_addr <= lwp->stop_pc
1530 && lwp->stop_pc < status.adjusted_insn_addr_end))
1533 struct regcache *regcache;
1535 /* The si_addr on a few signals references the address
1536 of the faulting instruction. Adjust that as
1538 if ((WSTOPSIG (*wstat) == SIGILL
1539 || WSTOPSIG (*wstat) == SIGFPE
1540 || WSTOPSIG (*wstat) == SIGBUS
1541 || WSTOPSIG (*wstat) == SIGSEGV)
1542 && ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread),
1543 (PTRACE_TYPE_ARG3) 0, &info) == 0
1544 /* Final check just to make sure we don't clobber
1545 the siginfo of non-kernel-sent signals. */
1546 && (uintptr_t) info.si_addr == lwp->stop_pc)
1548 info.si_addr = (void *) (uintptr_t) status.tpoint_addr;
1549 ptrace (PTRACE_SETSIGINFO, lwpid_of (current_thread),
1550 (PTRACE_TYPE_ARG3) 0, &info);
1553 regcache = get_thread_regcache (current_thread, 1);
1554 (*the_low_target.set_pc) (regcache, status.tpoint_addr);
1555 lwp->stop_pc = status.tpoint_addr;
1557 /* Cancel any fast tracepoint lock this thread was
1559 force_unlock_trace_buffer ();
1562 if (lwp->exit_jump_pad_bkpt != NULL)
1565 debug_printf ("Cancelling fast exit-jump-pad: removing bkpt. "
1566 "stopping all threads momentarily.\n");
1568 stop_all_lwps (1, lwp);
1569 cancel_breakpoints ();
1571 delete_breakpoint (lwp->exit_jump_pad_bkpt);
1572 lwp->exit_jump_pad_bkpt = NULL;
1574 unstop_all_lwps (1, lwp);
1576 gdb_assert (lwp->suspended >= 0);
1582 debug_printf ("Checking whether LWP %ld needs to move out of the "
1584 lwpid_of (current_thread));
1586 current_thread = saved_thread;
1590 /* Enqueue one signal in the "signals to report later when out of the
1594 enqueue_one_deferred_signal (struct lwp_info *lwp, int *wstat)
1596 struct pending_signals *p_sig;
1597 struct thread_info *thread = get_lwp_thread (lwp);
1600 debug_printf ("Deferring signal %d for LWP %ld.\n",
1601 WSTOPSIG (*wstat), lwpid_of (thread));
1605 struct pending_signals *sig;
1607 for (sig = lwp->pending_signals_to_report;
1610 debug_printf (" Already queued %d\n",
1613 debug_printf (" (no more currently queued signals)\n");
1616 /* Don't enqueue non-RT signals if they are already in the deferred
1617 queue. (SIGSTOP being the easiest signal to see ending up here
1619 if (WSTOPSIG (*wstat) < __SIGRTMIN)
1621 struct pending_signals *sig;
1623 for (sig = lwp->pending_signals_to_report;
1627 if (sig->signal == WSTOPSIG (*wstat))
1630 debug_printf ("Not requeuing already queued non-RT signal %d"
1639 p_sig = xmalloc (sizeof (*p_sig));
1640 p_sig->prev = lwp->pending_signals_to_report;
1641 p_sig->signal = WSTOPSIG (*wstat);
1642 memset (&p_sig->info, 0, sizeof (siginfo_t));
1643 ptrace (PTRACE_GETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0,
1646 lwp->pending_signals_to_report = p_sig;
1649 /* Dequeue one signal from the "signals to report later when out of
1650 the jump pad" list. */
1653 dequeue_one_deferred_signal (struct lwp_info *lwp, int *wstat)
1655 struct thread_info *thread = get_lwp_thread (lwp);
1657 if (lwp->pending_signals_to_report != NULL)
1659 struct pending_signals **p_sig;
1661 p_sig = &lwp->pending_signals_to_report;
1662 while ((*p_sig)->prev != NULL)
1663 p_sig = &(*p_sig)->prev;
1665 *wstat = W_STOPCODE ((*p_sig)->signal);
1666 if ((*p_sig)->info.si_signo != 0)
1667 ptrace (PTRACE_SETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0,
1673 debug_printf ("Reporting deferred signal %d for LWP %ld.\n",
1674 WSTOPSIG (*wstat), lwpid_of (thread));
1678 struct pending_signals *sig;
1680 for (sig = lwp->pending_signals_to_report;
1683 debug_printf (" Still queued %d\n",
1686 debug_printf (" (no more queued signals)\n");
1695 /* Arrange for a breakpoint to be hit again later. We don't keep the
1696 SIGTRAP status and don't forward the SIGTRAP signal to the LWP. We
1697 will handle the current event, eventually we will resume this LWP,
1698 and this breakpoint will trap again. */
1701 cancel_breakpoint (struct lwp_info *lwp)
1703 struct thread_info *saved_thread;
1705 /* There's nothing to do if we don't support breakpoints. */
1706 if (!supports_breakpoints ())
1709 /* breakpoint_at reads from current inferior. */
1710 saved_thread = current_thread;
1711 current_thread = get_lwp_thread (lwp);
1713 if ((*the_low_target.breakpoint_at) (lwp->stop_pc))
1716 debug_printf ("CB: Push back breakpoint for %s\n",
1717 target_pid_to_str (ptid_of (current_thread)));
1719 /* Back up the PC if necessary. */
1720 if (the_low_target.decr_pc_after_break)
1722 struct regcache *regcache
1723 = get_thread_regcache (current_thread, 1);
1724 (*the_low_target.set_pc) (regcache, lwp->stop_pc);
1727 current_thread = saved_thread;
1733 debug_printf ("CB: No breakpoint found at %s for [%s]\n",
1734 paddress (lwp->stop_pc),
1735 target_pid_to_str (ptid_of (current_thread)));
1738 current_thread = saved_thread;
1742 /* Do low-level handling of the event, and check if we should go on
1743 and pass it to caller code. Return the affected lwp if we are, or
1746 static struct lwp_info *
1747 linux_low_filter_event (ptid_t filter_ptid, int lwpid, int wstat)
1749 struct lwp_info *child;
1750 struct thread_info *thread;
1752 child = find_lwp_pid (pid_to_ptid (lwpid));
1754 /* If we didn't find a process, one of two things presumably happened:
1755 - A process we started and then detached from has exited. Ignore it.
1756 - A process we are controlling has forked and the new child's stop
1757 was reported to us by the kernel. Save its PID. */
1758 if (child == NULL && WIFSTOPPED (wstat))
1760 add_to_pid_list (&stopped_pids, lwpid, wstat);
1763 else if (child == NULL)
1766 thread = get_lwp_thread (child);
1770 child->last_status = wstat;
1772 if (WIFSTOPPED (wstat))
1774 struct process_info *proc;
1776 /* Architecture-specific setup after inferior is running. This
1777 needs to happen after we have attached to the inferior and it
1778 is stopped for the first time, but before we access any
1779 inferior registers. */
1780 proc = find_process_pid (pid_of (thread));
1781 if (proc->private->new_inferior)
1783 struct thread_info *saved_thread;
1785 saved_thread = current_thread;
1786 current_thread = thread;
1788 the_low_target.arch_setup ();
1790 current_thread = saved_thread;
1792 proc->private->new_inferior = 0;
1796 /* Store the STOP_PC, with adjustment applied. This depends on the
1797 architecture being defined already (so that CHILD has a valid
1798 regcache), and on LAST_STATUS being set (to check for SIGTRAP or
1800 if (WIFSTOPPED (wstat))
1803 && the_low_target.get_pc != NULL)
1805 struct thread_info *saved_thread;
1806 struct regcache *regcache;
1809 saved_thread = current_thread;
1810 current_thread = thread;
1811 regcache = get_thread_regcache (current_thread, 1);
1812 pc = (*the_low_target.get_pc) (regcache);
1813 debug_printf ("linux_low_filter_event: pc is 0x%lx\n", (long) pc);
1814 current_thread = saved_thread;
1817 child->stop_pc = get_stop_pc (child);
1820 /* Fetch the possibly triggered data watchpoint info and store it in
1823 On some archs, like x86, that use debug registers to set
1824 watchpoints, it's possible that the way to know which watched
1825 address trapped, is to check the register that is used to select
1826 which address to watch. Problem is, between setting the
1827 watchpoint and reading back which data address trapped, the user
1828 may change the set of watchpoints, and, as a consequence, GDB
1829 changes the debug registers in the inferior. To avoid reading
1830 back a stale stopped-data-address when that happens, we cache in
1831 LP the fact that a watchpoint trapped, and the corresponding data
1832 address, as soon as we see CHILD stop with a SIGTRAP. If GDB
1833 changes the debug registers meanwhile, we have the cached data we
1836 if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP)
1838 if (the_low_target.stopped_by_watchpoint == NULL)
1840 child->stopped_by_watchpoint = 0;
1844 struct thread_info *saved_thread;
1846 saved_thread = current_thread;
1847 current_thread = thread;
1849 child->stopped_by_watchpoint
1850 = the_low_target.stopped_by_watchpoint ();
1852 if (child->stopped_by_watchpoint)
1854 if (the_low_target.stopped_data_address != NULL)
1855 child->stopped_data_address
1856 = the_low_target.stopped_data_address ();
1858 child->stopped_data_address = 0;
1861 current_thread = saved_thread;
1865 if (WIFSTOPPED (wstat) && child->must_set_ptrace_flags)
1867 linux_enable_event_reporting (lwpid);
1868 child->must_set_ptrace_flags = 0;
1871 if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP
1872 && wstat >> 16 != 0)
1874 handle_extended_wait (child, wstat);
1878 if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGSTOP
1879 && child->stop_expected)
1882 debug_printf ("Expected stop.\n");
1883 child->stop_expected = 0;
1885 if (thread->last_resume_kind == resume_stop)
1887 /* We want to report the stop to the core. Treat the
1888 SIGSTOP as a normal event. */
1890 else if (stopping_threads != NOT_STOPPING_THREADS)
1892 /* Stopping threads. We don't want this SIGSTOP to end up
1893 pending in the FILTER_PTID handling below. */
1898 /* Filter out the event. */
1899 linux_resume_one_lwp (child, child->stepping, 0, NULL);
1904 /* Check if the thread has exited. */
1905 if ((WIFEXITED (wstat) || WIFSIGNALED (wstat))
1906 && num_lwps (pid_of (thread)) > 1)
1909 debug_printf ("LLW: %d exited.\n", lwpid);
1911 /* If there is at least one more LWP, then the exit signal
1912 was not the end of the debugged application and should be
1918 if (!ptid_match (ptid_of (thread), filter_ptid))
1921 debug_printf ("LWP %d got an event %06x, leaving pending.\n",
1924 if (WIFSTOPPED (wstat))
1926 child->status_pending_p = 1;
1927 child->status_pending = wstat;
1929 if (WSTOPSIG (wstat) != SIGSTOP)
1931 /* Cancel breakpoint hits. The breakpoint may be
1932 removed before we fetch events from this process to
1933 report to the core. It is best not to assume the
1934 moribund breakpoints heuristic always handles these
1935 cases --- it could be too many events go through to
1936 the core before this one is handled. All-stop always
1937 cancels breakpoint hits in all threads. */
1939 && WSTOPSIG (wstat) == SIGTRAP
1940 && cancel_breakpoint (child))
1942 /* Throw away the SIGTRAP. */
1943 child->status_pending_p = 0;
1946 debug_printf ("LLW: LWP %d hit a breakpoint while"
1947 " waiting for another process;"
1948 " cancelled it\n", lwpid);
1952 else if (WIFEXITED (wstat) || WIFSIGNALED (wstat))
1955 debug_printf ("LLWE: process %d exited while fetching "
1956 "event from another LWP\n", lwpid);
1958 /* This was the last lwp in the process. Since events are
1959 serialized to GDB core, and we can't report this one
1960 right now, but GDB core and the other target layers will
1961 want to be notified about the exit code/signal, leave the
1962 status pending for the next time we're able to report
1964 mark_lwp_dead (child, wstat);
1973 /* When the event-loop is doing a step-over, this points at the thread
1975 ptid_t step_over_bkpt;
1977 /* Wait for an event from child(ren) WAIT_PTID, and return any that
1978 match FILTER_PTID (leaving others pending). The PTIDs can be:
1979 minus_one_ptid, to specify any child; a pid PTID, specifying all
1980 lwps of a thread group; or a PTID representing a single lwp. Store
1981 the stop status through the status pointer WSTAT. OPTIONS is
1982 passed to the waitpid call. Return 0 if no event was found and
1983 OPTIONS contains WNOHANG. Return -1 if no unwaited-for children
1984 was found. Return the PID of the stopped child otherwise. */
1987 linux_wait_for_event_filtered (ptid_t wait_ptid, ptid_t filter_ptid,
1988 int *wstatp, int options)
1990 struct thread_info *event_thread;
1991 struct lwp_info *event_child, *requested_child;
1992 sigset_t block_mask, prev_mask;
1995 /* N.B. event_thread points to the thread_info struct that contains
1996 event_child. Keep them in sync. */
1997 event_thread = NULL;
1999 requested_child = NULL;
2001 /* Check for a lwp with a pending status. */
2003 if (ptid_equal (filter_ptid, minus_one_ptid) || ptid_is_pid (filter_ptid))
2005 event_thread = (struct thread_info *)
2006 find_inferior (&all_threads, status_pending_p_callback, &filter_ptid);
2007 if (event_thread != NULL)
2008 event_child = get_thread_lwp (event_thread);
2009 if (debug_threads && event_thread)
2010 debug_printf ("Got a pending child %ld\n", lwpid_of (event_thread));
2012 else if (!ptid_equal (filter_ptid, null_ptid))
2014 requested_child = find_lwp_pid (filter_ptid);
2016 if (stopping_threads == NOT_STOPPING_THREADS
2017 && requested_child->status_pending_p
2018 && requested_child->collecting_fast_tracepoint)
2020 enqueue_one_deferred_signal (requested_child,
2021 &requested_child->status_pending);
2022 requested_child->status_pending_p = 0;
2023 requested_child->status_pending = 0;
2024 linux_resume_one_lwp (requested_child, 0, 0, NULL);
2027 if (requested_child->suspended
2028 && requested_child->status_pending_p)
2030 internal_error (__FILE__, __LINE__,
2031 "requesting an event out of a"
2032 " suspended child?");
2035 if (requested_child->status_pending_p)
2037 event_child = requested_child;
2038 event_thread = get_lwp_thread (event_child);
2042 if (event_child != NULL)
2045 debug_printf ("Got an event from pending child %ld (%04x)\n",
2046 lwpid_of (event_thread), event_child->status_pending);
2047 *wstatp = event_child->status_pending;
2048 event_child->status_pending_p = 0;
2049 event_child->status_pending = 0;
2050 current_thread = event_thread;
2051 return lwpid_of (event_thread);
2054 /* But if we don't find a pending event, we'll have to wait.
2056 We only enter this loop if no process has a pending wait status.
2057 Thus any action taken in response to a wait status inside this
2058 loop is responding as soon as we detect the status, not after any
2061 /* Make sure SIGCHLD is blocked until the sigsuspend below. Block
2062 all signals while here. */
2063 sigfillset (&block_mask);
2064 sigprocmask (SIG_BLOCK, &block_mask, &prev_mask);
2066 while (event_child == NULL)
2070 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
2073 - If the thread group leader exits while other threads in the
2074 thread group still exist, waitpid(TGID, ...) hangs. That
2075 waitpid won't return an exit status until the other threads
2076 in the group are reaped.
2078 - When a non-leader thread execs, that thread just vanishes
2079 without reporting an exit (so we'd hang if we waited for it
2080 explicitly in that case). The exec event is reported to
2081 the TGID pid (although we don't currently enable exec
2084 ret = my_waitpid (-1, wstatp, options | WNOHANG);
2087 debug_printf ("LWFE: waitpid(-1, ...) returned %d, %s\n",
2088 ret, errno ? strerror (errno) : "ERRNO-OK");
2094 debug_printf ("LLW: waitpid %ld received %s\n",
2095 (long) ret, status_to_str (*wstatp));
2098 event_child = linux_low_filter_event (filter_ptid,
2100 if (event_child != NULL)
2102 /* We got an event to report to the core. */
2103 event_thread = get_lwp_thread (event_child);
2107 /* Retry until nothing comes out of waitpid. A single
2108 SIGCHLD can indicate more than one child stopped. */
2112 /* Check for zombie thread group leaders. Those can't be reaped
2113 until all other threads in the thread group are. */
2114 check_zombie_leaders ();
2116 /* If there are no resumed children left in the set of LWPs we
2117 want to wait for, bail. We can't just block in
2118 waitpid/sigsuspend, because lwps might have been left stopped
2119 in trace-stop state, and we'd be stuck forever waiting for
2120 their status to change (which would only happen if we resumed
2121 them). Even if WNOHANG is set, this return code is preferred
2122 over 0 (below), as it is more detailed. */
2123 if ((find_inferior (&all_threads,
2124 not_stopped_callback,
2125 &wait_ptid) == NULL))
2128 debug_printf ("LLW: exit (no unwaited-for LWP)\n");
2129 sigprocmask (SIG_SETMASK, &prev_mask, NULL);
2133 /* No interesting event to report to the caller. */
2134 if ((options & WNOHANG))
2137 debug_printf ("WNOHANG set, no event found\n");
2139 sigprocmask (SIG_SETMASK, &prev_mask, NULL);
2143 /* Block until we get an event reported with SIGCHLD. */
2145 debug_printf ("sigsuspend'ing\n");
2147 sigsuspend (&prev_mask);
2148 sigprocmask (SIG_SETMASK, &prev_mask, NULL);
2152 sigprocmask (SIG_SETMASK, &prev_mask, NULL);
2154 current_thread = event_thread;
2156 /* Check for thread exit. */
2157 if (! WIFSTOPPED (*wstatp))
2159 gdb_assert (last_thread_of_process_p (pid_of (event_thread)));
2162 debug_printf ("LWP %d is the last lwp of process. "
2163 "Process %ld exiting.\n",
2164 pid_of (event_thread), lwpid_of (event_thread));
2165 return lwpid_of (event_thread);
2168 return lwpid_of (event_thread);
2171 /* Wait for an event from child(ren) PTID. PTIDs can be:
2172 minus_one_ptid, to specify any child; a pid PTID, specifying all
2173 lwps of a thread group; or a PTID representing a single lwp. Store
2174 the stop status through the status pointer WSTAT. OPTIONS is
2175 passed to the waitpid call. Return 0 if no event was found and
2176 OPTIONS contains WNOHANG. Return -1 if no unwaited-for children
2177 was found. Return the PID of the stopped child otherwise. */
2180 linux_wait_for_event (ptid_t ptid, int *wstatp, int options)
2182 return linux_wait_for_event_filtered (ptid, ptid, wstatp, options);
2185 /* Count the LWP's that have had events. */
2188 count_events_callback (struct inferior_list_entry *entry, void *data)
2190 struct thread_info *thread = (struct thread_info *) entry;
2191 struct lwp_info *lp = get_thread_lwp (thread);
2194 gdb_assert (count != NULL);
2196 /* Count only resumed LWPs that have a SIGTRAP event pending that
2197 should be reported to GDB. */
2198 if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
2199 && thread->last_resume_kind != resume_stop
2200 && lp->status_pending_p
2201 && WIFSTOPPED (lp->status_pending)
2202 && WSTOPSIG (lp->status_pending) == SIGTRAP
2203 && !breakpoint_inserted_here (lp->stop_pc))
2209 /* Select the LWP (if any) that is currently being single-stepped. */
2212 select_singlestep_lwp_callback (struct inferior_list_entry *entry, void *data)
2214 struct thread_info *thread = (struct thread_info *) entry;
2215 struct lwp_info *lp = get_thread_lwp (thread);
2217 if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
2218 && thread->last_resume_kind == resume_step
2219 && lp->status_pending_p)
2225 /* Select the Nth LWP that has had a SIGTRAP event that should be
2229 select_event_lwp_callback (struct inferior_list_entry *entry, void *data)
2231 struct thread_info *thread = (struct thread_info *) entry;
2232 struct lwp_info *lp = get_thread_lwp (thread);
2233 int *selector = data;
2235 gdb_assert (selector != NULL);
2237 /* Select only resumed LWPs that have a SIGTRAP event pending. */
2238 if (thread->last_resume_kind != resume_stop
2239 && thread->last_status.kind == TARGET_WAITKIND_IGNORE
2240 && lp->status_pending_p
2241 && WIFSTOPPED (lp->status_pending)
2242 && WSTOPSIG (lp->status_pending) == SIGTRAP
2243 && !breakpoint_inserted_here (lp->stop_pc))
2244 if ((*selector)-- == 0)
2251 cancel_breakpoints_callback (struct inferior_list_entry *entry, void *data)
2253 struct thread_info *thread = (struct thread_info *) entry;
2254 struct lwp_info *lp = get_thread_lwp (thread);
2255 struct lwp_info *event_lp = data;
2257 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
2261 /* If a LWP other than the LWP that we're reporting an event for has
2262 hit a GDB breakpoint (as opposed to some random trap signal),
2263 then just arrange for it to hit it again later. We don't keep
2264 the SIGTRAP status and don't forward the SIGTRAP signal to the
2265 LWP. We will handle the current event, eventually we will resume
2266 all LWPs, and this one will get its breakpoint trap again.
2268 If we do not do this, then we run the risk that the user will
2269 delete or disable the breakpoint, but the LWP will have already
2272 if (thread->last_resume_kind != resume_stop
2273 && thread->last_status.kind == TARGET_WAITKIND_IGNORE
2274 && lp->status_pending_p
2275 && WIFSTOPPED (lp->status_pending)
2276 && WSTOPSIG (lp->status_pending) == SIGTRAP
2278 && !lp->stopped_by_watchpoint
2279 && cancel_breakpoint (lp))
2280 /* Throw away the SIGTRAP. */
2281 lp->status_pending_p = 0;
2287 linux_cancel_breakpoints (void)
2289 find_inferior (&all_threads, cancel_breakpoints_callback, NULL);
2292 /* Select one LWP out of those that have events pending. */
2295 select_event_lwp (struct lwp_info **orig_lp)
2298 int random_selector;
2299 struct thread_info *event_thread;
2301 /* Give preference to any LWP that is being single-stepped. */
2303 = (struct thread_info *) find_inferior (&all_threads,
2304 select_singlestep_lwp_callback,
2306 if (event_thread != NULL)
2309 debug_printf ("SEL: Select single-step %s\n",
2310 target_pid_to_str (ptid_of (event_thread)));
2314 /* No single-stepping LWP. Select one at random, out of those
2315 which have had SIGTRAP events. */
2317 /* First see how many SIGTRAP events we have. */
2318 find_inferior (&all_threads, count_events_callback, &num_events);
2320 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
2321 random_selector = (int)
2322 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
2324 if (debug_threads && num_events > 1)
2325 debug_printf ("SEL: Found %d SIGTRAP events, selecting #%d\n",
2326 num_events, random_selector);
2329 = (struct thread_info *) find_inferior (&all_threads,
2330 select_event_lwp_callback,
2334 if (event_thread != NULL)
2336 struct lwp_info *event_lp = get_thread_lwp (event_thread);
2338 /* Switch the event LWP. */
2339 *orig_lp = event_lp;
2343 /* Decrement the suspend count of an LWP. */
2346 unsuspend_one_lwp (struct inferior_list_entry *entry, void *except)
2348 struct thread_info *thread = (struct thread_info *) entry;
2349 struct lwp_info *lwp = get_thread_lwp (thread);
2351 /* Ignore EXCEPT. */
2357 gdb_assert (lwp->suspended >= 0);
2361 /* Decrement the suspend count of all LWPs, except EXCEPT, if non
2365 unsuspend_all_lwps (struct lwp_info *except)
2367 find_inferior (&all_threads, unsuspend_one_lwp, except);
2370 static void move_out_of_jump_pad_callback (struct inferior_list_entry *entry);
2371 static int stuck_in_jump_pad_callback (struct inferior_list_entry *entry,
2373 static int lwp_running (struct inferior_list_entry *entry, void *data);
2374 static ptid_t linux_wait_1 (ptid_t ptid,
2375 struct target_waitstatus *ourstatus,
2376 int target_options);
2378 /* Stabilize threads (move out of jump pads).
2380 If a thread is midway collecting a fast tracepoint, we need to
2381 finish the collection and move it out of the jump pad before
2382 reporting the signal.
2384 This avoids recursion while collecting (when a signal arrives
2385 midway, and the signal handler itself collects), which would trash
2386 the trace buffer. In case the user set a breakpoint in a signal
2387 handler, this avoids the backtrace showing the jump pad, etc..
2388 Most importantly, there are certain things we can't do safely if
2389 threads are stopped in a jump pad (or in its callee's). For
2392 - starting a new trace run. A thread still collecting the
2393 previous run, could trash the trace buffer when resumed. The trace
2394 buffer control structures would have been reset but the thread had
2395 no way to tell. The thread could even midway memcpy'ing to the
2396 buffer, which would mean that when resumed, it would clobber the
2397 trace buffer that had been set for a new run.
2399 - we can't rewrite/reuse the jump pads for new tracepoints
2400 safely. Say you do tstart while a thread is stopped midway while
2401 collecting. When the thread is later resumed, it finishes the
2402 collection, and returns to the jump pad, to execute the original
2403 instruction that was under the tracepoint jump at the time the
2404 older run had been started. If the jump pad had been rewritten
2405 since for something else in the new run, the thread would now
2406 execute the wrong / random instructions. */
2409 linux_stabilize_threads (void)
2411 struct thread_info *saved_thread;
2412 struct thread_info *thread_stuck;
2415 = (struct thread_info *) find_inferior (&all_threads,
2416 stuck_in_jump_pad_callback,
2418 if (thread_stuck != NULL)
2421 debug_printf ("can't stabilize, LWP %ld is stuck in jump pad\n",
2422 lwpid_of (thread_stuck));
2426 saved_thread = current_thread;
2428 stabilizing_threads = 1;
2431 for_each_inferior (&all_threads, move_out_of_jump_pad_callback);
2433 /* Loop until all are stopped out of the jump pads. */
2434 while (find_inferior (&all_threads, lwp_running, NULL) != NULL)
2436 struct target_waitstatus ourstatus;
2437 struct lwp_info *lwp;
2440 /* Note that we go through the full wait even loop. While
2441 moving threads out of jump pad, we need to be able to step
2442 over internal breakpoints and such. */
2443 linux_wait_1 (minus_one_ptid, &ourstatus, 0);
2445 if (ourstatus.kind == TARGET_WAITKIND_STOPPED)
2447 lwp = get_thread_lwp (current_thread);
2452 if (ourstatus.value.sig != GDB_SIGNAL_0
2453 || current_thread->last_resume_kind == resume_stop)
2455 wstat = W_STOPCODE (gdb_signal_to_host (ourstatus.value.sig));
2456 enqueue_one_deferred_signal (lwp, &wstat);
2461 find_inferior (&all_threads, unsuspend_one_lwp, NULL);
2463 stabilizing_threads = 0;
2465 current_thread = saved_thread;
2470 = (struct thread_info *) find_inferior (&all_threads,
2471 stuck_in_jump_pad_callback,
2473 if (thread_stuck != NULL)
2474 debug_printf ("couldn't stabilize, LWP %ld got stuck in jump pad\n",
2475 lwpid_of (thread_stuck));
2479 /* Wait for process, returns status. */
2482 linux_wait_1 (ptid_t ptid,
2483 struct target_waitstatus *ourstatus, int target_options)
2486 struct lwp_info *event_child;
2489 int step_over_finished;
2490 int bp_explains_trap;
2491 int maybe_internal_trap;
2499 debug_printf ("linux_wait_1: [%s]\n", target_pid_to_str (ptid));
2502 /* Translate generic target options into linux options. */
2504 if (target_options & TARGET_WNOHANG)
2508 bp_explains_trap = 0;
2511 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2513 /* If we were only supposed to resume one thread, only wait for
2514 that thread - if it's still alive. If it died, however - which
2515 can happen if we're coming from the thread death case below -
2516 then we need to make sure we restart the other threads. We could
2517 pick a thread at random or restart all; restarting all is less
2520 && !ptid_equal (cont_thread, null_ptid)
2521 && !ptid_equal (cont_thread, minus_one_ptid))
2523 struct thread_info *thread;
2525 thread = (struct thread_info *) find_inferior_id (&all_threads,
2528 /* No stepping, no signal - unless one is pending already, of course. */
2531 struct thread_resume resume_info;
2532 resume_info.thread = minus_one_ptid;
2533 resume_info.kind = resume_continue;
2534 resume_info.sig = 0;
2535 linux_resume (&resume_info, 1);
2541 if (ptid_equal (step_over_bkpt, null_ptid))
2542 pid = linux_wait_for_event (ptid, &w, options);
2546 debug_printf ("step_over_bkpt set [%s], doing a blocking wait\n",
2547 target_pid_to_str (step_over_bkpt));
2548 pid = linux_wait_for_event (step_over_bkpt, &w, options & ~WNOHANG);
2553 gdb_assert (target_options & TARGET_WNOHANG);
2557 debug_printf ("linux_wait_1 ret = null_ptid, "
2558 "TARGET_WAITKIND_IGNORE\n");
2562 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2569 debug_printf ("linux_wait_1 ret = null_ptid, "
2570 "TARGET_WAITKIND_NO_RESUMED\n");
2574 ourstatus->kind = TARGET_WAITKIND_NO_RESUMED;
2578 event_child = get_thread_lwp (current_thread);
2580 /* linux_wait_for_event only returns an exit status for the last
2581 child of a process. Report it. */
2582 if (WIFEXITED (w) || WIFSIGNALED (w))
2586 ourstatus->kind = TARGET_WAITKIND_EXITED;
2587 ourstatus->value.integer = WEXITSTATUS (w);
2591 debug_printf ("linux_wait_1 ret = %s, exited with "
2593 target_pid_to_str (ptid_of (current_thread)),
2600 ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
2601 ourstatus->value.sig = gdb_signal_from_host (WTERMSIG (w));
2605 debug_printf ("linux_wait_1 ret = %s, terminated with "
2607 target_pid_to_str (ptid_of (current_thread)),
2613 return ptid_of (current_thread);
2616 /* If this event was not handled before, and is not a SIGTRAP, we
2617 report it. SIGILL and SIGSEGV are also treated as traps in case
2618 a breakpoint is inserted at the current PC. If this target does
2619 not support internal breakpoints at all, we also report the
2620 SIGTRAP without further processing; it's of no concern to us. */
2622 = (supports_breakpoints ()
2623 && (WSTOPSIG (w) == SIGTRAP
2624 || ((WSTOPSIG (w) == SIGILL
2625 || WSTOPSIG (w) == SIGSEGV)
2626 && (*the_low_target.breakpoint_at) (event_child->stop_pc))));
2628 if (maybe_internal_trap)
2630 /* Handle anything that requires bookkeeping before deciding to
2631 report the event or continue waiting. */
2633 /* First check if we can explain the SIGTRAP with an internal
2634 breakpoint, or if we should possibly report the event to GDB.
2635 Do this before anything that may remove or insert a
2637 bp_explains_trap = breakpoint_inserted_here (event_child->stop_pc);
2639 /* We have a SIGTRAP, possibly a step-over dance has just
2640 finished. If so, tweak the state machine accordingly,
2641 reinsert breakpoints and delete any reinsert (software
2642 single-step) breakpoints. */
2643 step_over_finished = finish_step_over (event_child);
2645 /* Now invoke the callbacks of any internal breakpoints there. */
2646 check_breakpoints (event_child->stop_pc);
2648 /* Handle tracepoint data collecting. This may overflow the
2649 trace buffer, and cause a tracing stop, removing
2651 trace_event = handle_tracepoints (event_child);
2653 if (bp_explains_trap)
2655 /* If we stepped or ran into an internal breakpoint, we've
2656 already handled it. So next time we resume (from this
2657 PC), we should step over it. */
2659 debug_printf ("Hit a gdbserver breakpoint.\n");
2661 if (breakpoint_here (event_child->stop_pc))
2662 event_child->need_step_over = 1;
2667 /* We have some other signal, possibly a step-over dance was in
2668 progress, and it should be cancelled too. */
2669 step_over_finished = finish_step_over (event_child);
2672 /* We have all the data we need. Either report the event to GDB, or
2673 resume threads and keep waiting for more. */
2675 /* If we're collecting a fast tracepoint, finish the collection and
2676 move out of the jump pad before delivering a signal. See
2677 linux_stabilize_threads. */
2680 && WSTOPSIG (w) != SIGTRAP
2681 && supports_fast_tracepoints ()
2682 && agent_loaded_p ())
2685 debug_printf ("Got signal %d for LWP %ld. Check if we need "
2686 "to defer or adjust it.\n",
2687 WSTOPSIG (w), lwpid_of (current_thread));
2689 /* Allow debugging the jump pad itself. */
2690 if (current_thread->last_resume_kind != resume_step
2691 && maybe_move_out_of_jump_pad (event_child, &w))
2693 enqueue_one_deferred_signal (event_child, &w);
2696 debug_printf ("Signal %d for LWP %ld deferred (in jump pad)\n",
2697 WSTOPSIG (w), lwpid_of (current_thread));
2699 linux_resume_one_lwp (event_child, 0, 0, NULL);
2704 if (event_child->collecting_fast_tracepoint)
2707 debug_printf ("LWP %ld was trying to move out of the jump pad (%d). "
2708 "Check if we're already there.\n",
2709 lwpid_of (current_thread),
2710 event_child->collecting_fast_tracepoint);
2714 event_child->collecting_fast_tracepoint
2715 = linux_fast_tracepoint_collecting (event_child, NULL);
2717 if (event_child->collecting_fast_tracepoint != 1)
2719 /* No longer need this breakpoint. */
2720 if (event_child->exit_jump_pad_bkpt != NULL)
2723 debug_printf ("No longer need exit-jump-pad bkpt; removing it."
2724 "stopping all threads momentarily.\n");
2726 /* Other running threads could hit this breakpoint.
2727 We don't handle moribund locations like GDB does,
2728 instead we always pause all threads when removing
2729 breakpoints, so that any step-over or
2730 decr_pc_after_break adjustment is always taken
2731 care of while the breakpoint is still
2733 stop_all_lwps (1, event_child);
2734 cancel_breakpoints ();
2736 delete_breakpoint (event_child->exit_jump_pad_bkpt);
2737 event_child->exit_jump_pad_bkpt = NULL;
2739 unstop_all_lwps (1, event_child);
2741 gdb_assert (event_child->suspended >= 0);
2745 if (event_child->collecting_fast_tracepoint == 0)
2748 debug_printf ("fast tracepoint finished "
2749 "collecting successfully.\n");
2751 /* We may have a deferred signal to report. */
2752 if (dequeue_one_deferred_signal (event_child, &w))
2755 debug_printf ("dequeued one signal.\n");
2760 debug_printf ("no deferred signals.\n");
2762 if (stabilizing_threads)
2764 ourstatus->kind = TARGET_WAITKIND_STOPPED;
2765 ourstatus->value.sig = GDB_SIGNAL_0;
2769 debug_printf ("linux_wait_1 ret = %s, stopped "
2770 "while stabilizing threads\n",
2771 target_pid_to_str (ptid_of (current_thread)));
2775 return ptid_of (current_thread);
2781 /* Check whether GDB would be interested in this event. */
2783 /* If GDB is not interested in this signal, don't stop other
2784 threads, and don't report it to GDB. Just resume the inferior
2785 right away. We do this for threading-related signals as well as
2786 any that GDB specifically requested we ignore. But never ignore
2787 SIGSTOP if we sent it ourselves, and do not ignore signals when
2788 stepping - they may require special handling to skip the signal
2790 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
2793 && current_thread->last_resume_kind != resume_step
2795 #if defined (USE_THREAD_DB) && !defined (__ANDROID__)
2796 (current_process ()->private->thread_db != NULL
2797 && (WSTOPSIG (w) == __SIGRTMIN
2798 || WSTOPSIG (w) == __SIGRTMIN + 1))
2801 (pass_signals[gdb_signal_from_host (WSTOPSIG (w))]
2802 && !(WSTOPSIG (w) == SIGSTOP
2803 && current_thread->last_resume_kind == resume_stop))))
2805 siginfo_t info, *info_p;
2808 debug_printf ("Ignored signal %d for LWP %ld.\n",
2809 WSTOPSIG (w), lwpid_of (current_thread));
2811 if (ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread),
2812 (PTRACE_TYPE_ARG3) 0, &info) == 0)
2816 linux_resume_one_lwp (event_child, event_child->stepping,
2817 WSTOPSIG (w), info_p);
2821 /* Note that all addresses are always "out of the step range" when
2822 there's no range to begin with. */
2823 in_step_range = lwp_in_step_range (event_child);
2825 /* If GDB wanted this thread to single step, and the thread is out
2826 of the step range, we always want to report the SIGTRAP, and let
2827 GDB handle it. Watchpoints should always be reported. So should
2828 signals we can't explain. A SIGTRAP we can't explain could be a
2829 GDB breakpoint --- we may or not support Z0 breakpoints. If we
2830 do, we're be able to handle GDB breakpoints on top of internal
2831 breakpoints, by handling the internal breakpoint and still
2832 reporting the event to GDB. If we don't, we're out of luck, GDB
2833 won't see the breakpoint hit. */
2834 report_to_gdb = (!maybe_internal_trap
2835 || (current_thread->last_resume_kind == resume_step
2837 || event_child->stopped_by_watchpoint
2838 || (!step_over_finished && !in_step_range
2839 && !bp_explains_trap && !trace_event)
2840 || (gdb_breakpoint_here (event_child->stop_pc)
2841 && gdb_condition_true_at_breakpoint (event_child->stop_pc)
2842 && gdb_no_commands_at_breakpoint (event_child->stop_pc)));
2844 run_breakpoint_commands (event_child->stop_pc);
2846 /* We found no reason GDB would want us to stop. We either hit one
2847 of our own breakpoints, or finished an internal step GDB
2848 shouldn't know about. */
2853 if (bp_explains_trap)
2854 debug_printf ("Hit a gdbserver breakpoint.\n");
2855 if (step_over_finished)
2856 debug_printf ("Step-over finished.\n");
2858 debug_printf ("Tracepoint event.\n");
2859 if (lwp_in_step_range (event_child))
2860 debug_printf ("Range stepping pc 0x%s [0x%s, 0x%s).\n",
2861 paddress (event_child->stop_pc),
2862 paddress (event_child->step_range_start),
2863 paddress (event_child->step_range_end));
2866 /* We're not reporting this breakpoint to GDB, so apply the
2867 decr_pc_after_break adjustment to the inferior's regcache
2870 if (the_low_target.set_pc != NULL)
2872 struct regcache *regcache
2873 = get_thread_regcache (current_thread, 1);
2874 (*the_low_target.set_pc) (regcache, event_child->stop_pc);
2877 /* We may have finished stepping over a breakpoint. If so,
2878 we've stopped and suspended all LWPs momentarily except the
2879 stepping one. This is where we resume them all again. We're
2880 going to keep waiting, so use proceed, which handles stepping
2881 over the next breakpoint. */
2883 debug_printf ("proceeding all threads.\n");
2885 if (step_over_finished)
2886 unsuspend_all_lwps (event_child);
2888 proceed_all_lwps ();
2894 if (current_thread->last_resume_kind == resume_step)
2896 if (event_child->step_range_start == event_child->step_range_end)
2897 debug_printf ("GDB wanted to single-step, reporting event.\n");
2898 else if (!lwp_in_step_range (event_child))
2899 debug_printf ("Out of step range, reporting event.\n");
2901 if (event_child->stopped_by_watchpoint)
2902 debug_printf ("Stopped by watchpoint.\n");
2903 if (gdb_breakpoint_here (event_child->stop_pc))
2904 debug_printf ("Stopped by GDB breakpoint.\n");
2906 debug_printf ("Hit a non-gdbserver trap event.\n");
2909 /* Alright, we're going to report a stop. */
2911 if (!non_stop && !stabilizing_threads)
2913 /* In all-stop, stop all threads. */
2914 stop_all_lwps (0, NULL);
2916 /* If we're not waiting for a specific LWP, choose an event LWP
2917 from among those that have had events. Giving equal priority
2918 to all LWPs that have had events helps prevent
2920 if (ptid_equal (ptid, minus_one_ptid))
2922 event_child->status_pending_p = 1;
2923 event_child->status_pending = w;
2925 select_event_lwp (&event_child);
2927 /* current_thread and event_child must stay in sync. */
2928 current_thread = get_lwp_thread (event_child);
2930 event_child->status_pending_p = 0;
2931 w = event_child->status_pending;
2934 /* Now that we've selected our final event LWP, cancel any
2935 breakpoints in other LWPs that have hit a GDB breakpoint.
2936 See the comment in cancel_breakpoints_callback to find out
2938 find_inferior (&all_threads, cancel_breakpoints_callback, event_child);
2940 /* If we were going a step-over, all other threads but the stepping one
2941 had been paused in start_step_over, with their suspend counts
2942 incremented. We don't want to do a full unstop/unpause, because we're
2943 in all-stop mode (so we want threads stopped), but we still need to
2944 unsuspend the other threads, to decrement their `suspended' count
2946 if (step_over_finished)
2947 unsuspend_all_lwps (event_child);
2949 /* Stabilize threads (move out of jump pads). */
2950 stabilize_threads ();
2954 /* If we just finished a step-over, then all threads had been
2955 momentarily paused. In all-stop, that's fine, we want
2956 threads stopped by now anyway. In non-stop, we need to
2957 re-resume threads that GDB wanted to be running. */
2958 if (step_over_finished)
2959 unstop_all_lwps (1, event_child);
2962 ourstatus->kind = TARGET_WAITKIND_STOPPED;
2964 if (current_thread->last_resume_kind == resume_stop
2965 && WSTOPSIG (w) == SIGSTOP)
2967 /* A thread that has been requested to stop by GDB with vCont;t,
2968 and it stopped cleanly, so report as SIG0. The use of
2969 SIGSTOP is an implementation detail. */
2970 ourstatus->value.sig = GDB_SIGNAL_0;
2972 else if (current_thread->last_resume_kind == resume_stop
2973 && WSTOPSIG (w) != SIGSTOP)
2975 /* A thread that has been requested to stop by GDB with vCont;t,
2976 but, it stopped for other reasons. */
2977 ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w));
2981 ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w));
2984 gdb_assert (ptid_equal (step_over_bkpt, null_ptid));
2988 debug_printf ("linux_wait_1 ret = %s, %d, %d\n",
2989 target_pid_to_str (ptid_of (current_thread)),
2990 ourstatus->kind, ourstatus->value.sig);
2994 return ptid_of (current_thread);
2997 /* Get rid of any pending event in the pipe. */
2999 async_file_flush (void)
3005 ret = read (linux_event_pipe[0], &buf, 1);
3006 while (ret >= 0 || (ret == -1 && errno == EINTR));
3009 /* Put something in the pipe, so the event loop wakes up. */
3011 async_file_mark (void)
3015 async_file_flush ();
3018 ret = write (linux_event_pipe[1], "+", 1);
3019 while (ret == 0 || (ret == -1 && errno == EINTR));
3021 /* Ignore EAGAIN. If the pipe is full, the event loop will already
3022 be awakened anyway. */
3026 linux_wait (ptid_t ptid,
3027 struct target_waitstatus *ourstatus, int target_options)
3031 /* Flush the async file first. */
3032 if (target_is_async_p ())
3033 async_file_flush ();
3035 event_ptid = linux_wait_1 (ptid, ourstatus, target_options);
3037 /* If at least one stop was reported, there may be more. A single
3038 SIGCHLD can signal more than one child stop. */
3039 if (target_is_async_p ()
3040 && (target_options & TARGET_WNOHANG) != 0
3041 && !ptid_equal (event_ptid, null_ptid))
3047 /* Send a signal to an LWP. */
3050 kill_lwp (unsigned long lwpid, int signo)
3052 /* Use tkill, if possible, in case we are using nptl threads. If tkill
3053 fails, then we are not using nptl threads and we should be using kill. */
3057 static int tkill_failed;
3064 ret = syscall (__NR_tkill, lwpid, signo);
3065 if (errno != ENOSYS)
3072 return kill (lwpid, signo);
3076 linux_stop_lwp (struct lwp_info *lwp)
3082 send_sigstop (struct lwp_info *lwp)
3086 pid = lwpid_of (get_lwp_thread (lwp));
3088 /* If we already have a pending stop signal for this process, don't
3090 if (lwp->stop_expected)
3093 debug_printf ("Have pending sigstop for lwp %d\n", pid);
3099 debug_printf ("Sending sigstop to lwp %d\n", pid);
3101 lwp->stop_expected = 1;
3102 kill_lwp (pid, SIGSTOP);
3106 send_sigstop_callback (struct inferior_list_entry *entry, void *except)
3108 struct thread_info *thread = (struct thread_info *) entry;
3109 struct lwp_info *lwp = get_thread_lwp (thread);
3111 /* Ignore EXCEPT. */
3122 /* Increment the suspend count of an LWP, and stop it, if not stopped
3125 suspend_and_send_sigstop_callback (struct inferior_list_entry *entry,
3128 struct thread_info *thread = (struct thread_info *) entry;
3129 struct lwp_info *lwp = get_thread_lwp (thread);
3131 /* Ignore EXCEPT. */
3137 return send_sigstop_callback (entry, except);
3141 mark_lwp_dead (struct lwp_info *lwp, int wstat)
3143 /* It's dead, really. */
3146 /* Store the exit status for later. */
3147 lwp->status_pending_p = 1;
3148 lwp->status_pending = wstat;
3150 /* Prevent trying to stop it. */
3153 /* No further stops are expected from a dead lwp. */
3154 lwp->stop_expected = 0;
3157 /* Wait for all children to stop for the SIGSTOPs we just queued. */
3160 wait_for_sigstop (void)
3162 struct thread_info *saved_thread;
3167 saved_thread = current_thread;
3168 if (saved_thread != NULL)
3169 saved_tid = saved_thread->entry.id;
3171 saved_tid = null_ptid; /* avoid bogus unused warning */
3174 debug_printf ("wait_for_sigstop: pulling events\n");
3176 /* Passing NULL_PTID as filter indicates we want all events to be
3177 left pending. Eventually this returns when there are no
3178 unwaited-for children left. */
3179 ret = linux_wait_for_event_filtered (minus_one_ptid, null_ptid,
3181 gdb_assert (ret == -1);
3183 if (saved_thread == NULL || linux_thread_alive (saved_tid))
3184 current_thread = saved_thread;
3188 debug_printf ("Previously current thread died.\n");
3192 /* We can't change the current inferior behind GDB's back,
3193 otherwise, a subsequent command may apply to the wrong
3195 current_thread = NULL;
3199 /* Set a valid thread as current. */
3200 set_desired_thread (0);
3205 /* Returns true if LWP ENTRY is stopped in a jump pad, and we can't
3206 move it out, because we need to report the stop event to GDB. For
3207 example, if the user puts a breakpoint in the jump pad, it's
3208 because she wants to debug it. */
3211 stuck_in_jump_pad_callback (struct inferior_list_entry *entry, void *data)
3213 struct thread_info *thread = (struct thread_info *) entry;
3214 struct lwp_info *lwp = get_thread_lwp (thread);
3216 gdb_assert (lwp->suspended == 0);
3217 gdb_assert (lwp->stopped);
3219 /* Allow debugging the jump pad, gdb_collect, etc.. */
3220 return (supports_fast_tracepoints ()
3221 && agent_loaded_p ()
3222 && (gdb_breakpoint_here (lwp->stop_pc)
3223 || lwp->stopped_by_watchpoint
3224 || thread->last_resume_kind == resume_step)
3225 && linux_fast_tracepoint_collecting (lwp, NULL));
3229 move_out_of_jump_pad_callback (struct inferior_list_entry *entry)
3231 struct thread_info *thread = (struct thread_info *) entry;
3232 struct lwp_info *lwp = get_thread_lwp (thread);
3235 gdb_assert (lwp->suspended == 0);
3236 gdb_assert (lwp->stopped);
3238 wstat = lwp->status_pending_p ? &lwp->status_pending : NULL;
3240 /* Allow debugging the jump pad, gdb_collect, etc. */
3241 if (!gdb_breakpoint_here (lwp->stop_pc)
3242 && !lwp->stopped_by_watchpoint
3243 && thread->last_resume_kind != resume_step
3244 && maybe_move_out_of_jump_pad (lwp, wstat))
3247 debug_printf ("LWP %ld needs stabilizing (in jump pad)\n",
3252 lwp->status_pending_p = 0;
3253 enqueue_one_deferred_signal (lwp, wstat);
3256 debug_printf ("Signal %d for LWP %ld deferred "
3258 WSTOPSIG (*wstat), lwpid_of (thread));
3261 linux_resume_one_lwp (lwp, 0, 0, NULL);
3268 lwp_running (struct inferior_list_entry *entry, void *data)
3270 struct thread_info *thread = (struct thread_info *) entry;
3271 struct lwp_info *lwp = get_thread_lwp (thread);
3280 /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
3281 If SUSPEND, then also increase the suspend count of every LWP,
3285 stop_all_lwps (int suspend, struct lwp_info *except)
3287 /* Should not be called recursively. */
3288 gdb_assert (stopping_threads == NOT_STOPPING_THREADS);
3293 debug_printf ("stop_all_lwps (%s, except=%s)\n",
3294 suspend ? "stop-and-suspend" : "stop",
3296 ? target_pid_to_str (ptid_of (get_lwp_thread (except)))
3300 stopping_threads = (suspend
3301 ? STOPPING_AND_SUSPENDING_THREADS
3302 : STOPPING_THREADS);
3305 find_inferior (&all_threads, suspend_and_send_sigstop_callback, except);
3307 find_inferior (&all_threads, send_sigstop_callback, except);
3308 wait_for_sigstop ();
3309 stopping_threads = NOT_STOPPING_THREADS;
3313 debug_printf ("stop_all_lwps done, setting stopping_threads "
3314 "back to !stopping\n");
3319 /* Resume execution of the inferior process.
3320 If STEP is nonzero, single-step it.
3321 If SIGNAL is nonzero, give it that signal. */
3324 linux_resume_one_lwp (struct lwp_info *lwp,
3325 int step, int signal, siginfo_t *info)
3327 struct thread_info *thread = get_lwp_thread (lwp);
3328 struct thread_info *saved_thread;
3329 int fast_tp_collecting;
3331 if (lwp->stopped == 0)
3334 fast_tp_collecting = lwp->collecting_fast_tracepoint;
3336 gdb_assert (!stabilizing_threads || fast_tp_collecting);
3338 /* Cancel actions that rely on GDB not changing the PC (e.g., the
3339 user used the "jump" command, or "set $pc = foo"). */
3340 if (lwp->stop_pc != get_pc (lwp))
3342 /* Collecting 'while-stepping' actions doesn't make sense
3344 release_while_stepping_state_list (thread);
3347 /* If we have pending signals or status, and a new signal, enqueue the
3348 signal. Also enqueue the signal if we are waiting to reinsert a
3349 breakpoint; it will be picked up again below. */
3351 && (lwp->status_pending_p
3352 || lwp->pending_signals != NULL
3353 || lwp->bp_reinsert != 0
3354 || fast_tp_collecting))
3356 struct pending_signals *p_sig;
3357 p_sig = xmalloc (sizeof (*p_sig));
3358 p_sig->prev = lwp->pending_signals;
3359 p_sig->signal = signal;
3361 memset (&p_sig->info, 0, sizeof (siginfo_t));
3363 memcpy (&p_sig->info, info, sizeof (siginfo_t));
3364 lwp->pending_signals = p_sig;
3367 if (lwp->status_pending_p)
3370 debug_printf ("Not resuming lwp %ld (%s, signal %d, stop %s);"
3371 " has pending status\n",
3372 lwpid_of (thread), step ? "step" : "continue", signal,
3373 lwp->stop_expected ? "expected" : "not expected");
3377 saved_thread = current_thread;
3378 current_thread = thread;
3381 debug_printf ("Resuming lwp %ld (%s, signal %d, stop %s)\n",
3382 lwpid_of (thread), step ? "step" : "continue", signal,
3383 lwp->stop_expected ? "expected" : "not expected");
3385 /* This bit needs some thinking about. If we get a signal that
3386 we must report while a single-step reinsert is still pending,
3387 we often end up resuming the thread. It might be better to
3388 (ew) allow a stack of pending events; then we could be sure that
3389 the reinsert happened right away and not lose any signals.
3391 Making this stack would also shrink the window in which breakpoints are
3392 uninserted (see comment in linux_wait_for_lwp) but not enough for
3393 complete correctness, so it won't solve that problem. It may be
3394 worthwhile just to solve this one, however. */
3395 if (lwp->bp_reinsert != 0)
3398 debug_printf (" pending reinsert at 0x%s\n",
3399 paddress (lwp->bp_reinsert));
3401 if (can_hardware_single_step ())
3403 if (fast_tp_collecting == 0)
3406 fprintf (stderr, "BAD - reinserting but not stepping.\n");
3408 fprintf (stderr, "BAD - reinserting and suspended(%d).\n",
3415 /* Postpone any pending signal. It was enqueued above. */
3419 if (fast_tp_collecting == 1)
3422 debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad"
3423 " (exit-jump-pad-bkpt)\n",
3426 /* Postpone any pending signal. It was enqueued above. */
3429 else if (fast_tp_collecting == 2)
3432 debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad"
3433 " single-stepping\n",
3436 if (can_hardware_single_step ())
3440 internal_error (__FILE__, __LINE__,
3441 "moving out of jump pad single-stepping"
3442 " not implemented on this target");
3445 /* Postpone any pending signal. It was enqueued above. */
3449 /* If we have while-stepping actions in this thread set it stepping.
3450 If we have a signal to deliver, it may or may not be set to
3451 SIG_IGN, we don't know. Assume so, and allow collecting
3452 while-stepping into a signal handler. A possible smart thing to
3453 do would be to set an internal breakpoint at the signal return
3454 address, continue, and carry on catching this while-stepping
3455 action only when that breakpoint is hit. A future
3457 if (thread->while_stepping != NULL
3458 && can_hardware_single_step ())
3461 debug_printf ("lwp %ld has a while-stepping action -> forcing step.\n",
3466 if (debug_threads && the_low_target.get_pc != NULL)
3468 struct regcache *regcache = get_thread_regcache (current_thread, 1);
3469 CORE_ADDR pc = (*the_low_target.get_pc) (regcache);
3470 debug_printf (" resuming from pc 0x%lx\n", (long) pc);
3473 /* If we have pending signals, consume one unless we are trying to
3474 reinsert a breakpoint or we're trying to finish a fast tracepoint
3476 if (lwp->pending_signals != NULL
3477 && lwp->bp_reinsert == 0
3478 && fast_tp_collecting == 0)
3480 struct pending_signals **p_sig;
3482 p_sig = &lwp->pending_signals;
3483 while ((*p_sig)->prev != NULL)
3484 p_sig = &(*p_sig)->prev;
3486 signal = (*p_sig)->signal;
3487 if ((*p_sig)->info.si_signo != 0)
3488 ptrace (PTRACE_SETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0,
3495 if (the_low_target.prepare_to_resume != NULL)
3496 the_low_target.prepare_to_resume (lwp);
3498 regcache_invalidate_thread (thread);
3501 lwp->stopped_by_watchpoint = 0;
3502 lwp->stepping = step;
3503 ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (thread),
3504 (PTRACE_TYPE_ARG3) 0,
3505 /* Coerce to a uintptr_t first to avoid potential gcc warning
3506 of coercing an 8 byte integer to a 4 byte pointer. */
3507 (PTRACE_TYPE_ARG4) (uintptr_t) signal);
3509 current_thread = saved_thread;
3512 /* ESRCH from ptrace either means that the thread was already
3513 running (an error) or that it is gone (a race condition). If
3514 it's gone, we will get a notification the next time we wait,
3515 so we can ignore the error. We could differentiate these
3516 two, but it's tricky without waiting; the thread still exists
3517 as a zombie, so sending it signal 0 would succeed. So just
3522 perror_with_name ("ptrace");
3526 struct thread_resume_array
3528 struct thread_resume *resume;
3532 /* This function is called once per thread via find_inferior.
3533 ARG is a pointer to a thread_resume_array struct.
3534 We look up the thread specified by ENTRY in ARG, and mark the thread
3535 with a pointer to the appropriate resume request.
3537 This algorithm is O(threads * resume elements), but resume elements
3538 is small (and will remain small at least until GDB supports thread
3542 linux_set_resume_request (struct inferior_list_entry *entry, void *arg)
3544 struct thread_info *thread = (struct thread_info *) entry;
3545 struct lwp_info *lwp = get_thread_lwp (thread);
3547 struct thread_resume_array *r;
3551 for (ndx = 0; ndx < r->n; ndx++)
3553 ptid_t ptid = r->resume[ndx].thread;
3554 if (ptid_equal (ptid, minus_one_ptid)
3555 || ptid_equal (ptid, entry->id)
3556 /* Handle both 'pPID' and 'pPID.-1' as meaning 'all threads
3558 || (ptid_get_pid (ptid) == pid_of (thread)
3559 && (ptid_is_pid (ptid)
3560 || ptid_get_lwp (ptid) == -1)))
3562 if (r->resume[ndx].kind == resume_stop
3563 && thread->last_resume_kind == resume_stop)
3566 debug_printf ("already %s LWP %ld at GDB's request\n",
3567 (thread->last_status.kind
3568 == TARGET_WAITKIND_STOPPED)
3576 lwp->resume = &r->resume[ndx];
3577 thread->last_resume_kind = lwp->resume->kind;
3579 lwp->step_range_start = lwp->resume->step_range_start;
3580 lwp->step_range_end = lwp->resume->step_range_end;
3582 /* If we had a deferred signal to report, dequeue one now.
3583 This can happen if LWP gets more than one signal while
3584 trying to get out of a jump pad. */
3586 && !lwp->status_pending_p
3587 && dequeue_one_deferred_signal (lwp, &lwp->status_pending))
3589 lwp->status_pending_p = 1;
3592 debug_printf ("Dequeueing deferred signal %d for LWP %ld, "
3593 "leaving status pending.\n",
3594 WSTOPSIG (lwp->status_pending),
3602 /* No resume action for this thread. */
3608 /* find_inferior callback for linux_resume.
3609 Set *FLAG_P if this lwp has an interesting status pending. */
3612 resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p)
3614 struct thread_info *thread = (struct thread_info *) entry;
3615 struct lwp_info *lwp = get_thread_lwp (thread);
3617 /* LWPs which will not be resumed are not interesting, because
3618 we might not wait for them next time through linux_wait. */
3619 if (lwp->resume == NULL)
3622 if (lwp->status_pending_p)
3623 * (int *) flag_p = 1;
3628 /* Return 1 if this lwp that GDB wants running is stopped at an
3629 internal breakpoint that we need to step over. It assumes that any
3630 required STOP_PC adjustment has already been propagated to the
3631 inferior's regcache. */
3634 need_step_over_p (struct inferior_list_entry *entry, void *dummy)
3636 struct thread_info *thread = (struct thread_info *) entry;
3637 struct lwp_info *lwp = get_thread_lwp (thread);
3638 struct thread_info *saved_thread;
3641 /* LWPs which will not be resumed are not interesting, because we
3642 might not wait for them next time through linux_wait. */
3647 debug_printf ("Need step over [LWP %ld]? Ignoring, not stopped\n",
3652 if (thread->last_resume_kind == resume_stop)
3655 debug_printf ("Need step over [LWP %ld]? Ignoring, should remain"
3661 gdb_assert (lwp->suspended >= 0);
3666 debug_printf ("Need step over [LWP %ld]? Ignoring, suspended\n",
3671 if (!lwp->need_step_over)
3674 debug_printf ("Need step over [LWP %ld]? No\n", lwpid_of (thread));
3677 if (lwp->status_pending_p)
3680 debug_printf ("Need step over [LWP %ld]? Ignoring, has pending"
3686 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
3690 /* If the PC has changed since we stopped, then don't do anything,
3691 and let the breakpoint/tracepoint be hit. This happens if, for
3692 instance, GDB handled the decr_pc_after_break subtraction itself,
3693 GDB is OOL stepping this thread, or the user has issued a "jump"
3694 command, or poked thread's registers herself. */
3695 if (pc != lwp->stop_pc)
3698 debug_printf ("Need step over [LWP %ld]? Cancelling, PC was changed. "
3699 "Old stop_pc was 0x%s, PC is now 0x%s\n",
3701 paddress (lwp->stop_pc), paddress (pc));
3703 lwp->need_step_over = 0;
3707 saved_thread = current_thread;
3708 current_thread = thread;
3710 /* We can only step over breakpoints we know about. */
3711 if (breakpoint_here (pc) || fast_tracepoint_jump_here (pc))
3713 /* Don't step over a breakpoint that GDB expects to hit
3714 though. If the condition is being evaluated on the target's side
3715 and it evaluate to false, step over this breakpoint as well. */
3716 if (gdb_breakpoint_here (pc)
3717 && gdb_condition_true_at_breakpoint (pc)
3718 && gdb_no_commands_at_breakpoint (pc))
3721 debug_printf ("Need step over [LWP %ld]? yes, but found"
3722 " GDB breakpoint at 0x%s; skipping step over\n",
3723 lwpid_of (thread), paddress (pc));
3725 current_thread = saved_thread;
3731 debug_printf ("Need step over [LWP %ld]? yes, "
3732 "found breakpoint at 0x%s\n",
3733 lwpid_of (thread), paddress (pc));
3735 /* We've found an lwp that needs stepping over --- return 1 so
3736 that find_inferior stops looking. */
3737 current_thread = saved_thread;
3739 /* If the step over is cancelled, this is set again. */
3740 lwp->need_step_over = 0;
3745 current_thread = saved_thread;
3748 debug_printf ("Need step over [LWP %ld]? No, no breakpoint found"
3750 lwpid_of (thread), paddress (pc));
3755 /* Start a step-over operation on LWP. When LWP stopped at a
3756 breakpoint, to make progress, we need to remove the breakpoint out
3757 of the way. If we let other threads run while we do that, they may
3758 pass by the breakpoint location and miss hitting it. To avoid
3759 that, a step-over momentarily stops all threads while LWP is
3760 single-stepped while the breakpoint is temporarily uninserted from
3761 the inferior. When the single-step finishes, we reinsert the
3762 breakpoint, and let all threads that are supposed to be running,
3765 On targets that don't support hardware single-step, we don't
3766 currently support full software single-stepping. Instead, we only
3767 support stepping over the thread event breakpoint, by asking the
3768 low target where to place a reinsert breakpoint. Since this
3769 routine assumes the breakpoint being stepped over is a thread event
3770 breakpoint, it usually assumes the return address of the current
3771 function is a good enough place to set the reinsert breakpoint. */
3774 start_step_over (struct lwp_info *lwp)
3776 struct thread_info *thread = get_lwp_thread (lwp);
3777 struct thread_info *saved_thread;
3782 debug_printf ("Starting step-over on LWP %ld. Stopping all threads\n",
3785 stop_all_lwps (1, lwp);
3786 gdb_assert (lwp->suspended == 0);
3789 debug_printf ("Done stopping all threads for step-over.\n");
3791 /* Note, we should always reach here with an already adjusted PC,
3792 either by GDB (if we're resuming due to GDB's request), or by our
3793 caller, if we just finished handling an internal breakpoint GDB
3794 shouldn't care about. */
3797 saved_thread = current_thread;
3798 current_thread = thread;
3800 lwp->bp_reinsert = pc;
3801 uninsert_breakpoints_at (pc);
3802 uninsert_fast_tracepoint_jumps_at (pc);
3804 if (can_hardware_single_step ())
3810 CORE_ADDR raddr = (*the_low_target.breakpoint_reinsert_addr) ();
3811 set_reinsert_breakpoint (raddr);
3815 current_thread = saved_thread;
3817 linux_resume_one_lwp (lwp, step, 0, NULL);
3819 /* Require next event from this LWP. */
3820 step_over_bkpt = thread->entry.id;
3824 /* Finish a step-over. Reinsert the breakpoint we had uninserted in
3825 start_step_over, if still there, and delete any reinsert
3826 breakpoints we've set, on non hardware single-step targets. */
3829 finish_step_over (struct lwp_info *lwp)
3831 if (lwp->bp_reinsert != 0)
3834 debug_printf ("Finished step over.\n");
3836 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
3837 may be no breakpoint to reinsert there by now. */
3838 reinsert_breakpoints_at (lwp->bp_reinsert);
3839 reinsert_fast_tracepoint_jumps_at (lwp->bp_reinsert);
3841 lwp->bp_reinsert = 0;
3843 /* Delete any software-single-step reinsert breakpoints. No
3844 longer needed. We don't have to worry about other threads
3845 hitting this trap, and later not being able to explain it,
3846 because we were stepping over a breakpoint, and we hold all
3847 threads but LWP stopped while doing that. */
3848 if (!can_hardware_single_step ())
3849 delete_reinsert_breakpoints ();
3851 step_over_bkpt = null_ptid;
3858 /* This function is called once per thread. We check the thread's resume
3859 request, which will tell us whether to resume, step, or leave the thread
3860 stopped; and what signal, if any, it should be sent.
3862 For threads which we aren't explicitly told otherwise, we preserve
3863 the stepping flag; this is used for stepping over gdbserver-placed
3866 If pending_flags was set in any thread, we queue any needed
3867 signals, since we won't actually resume. We already have a pending
3868 event to report, so we don't need to preserve any step requests;
3869 they should be re-issued if necessary. */
3872 linux_resume_one_thread (struct inferior_list_entry *entry, void *arg)
3874 struct thread_info *thread = (struct thread_info *) entry;
3875 struct lwp_info *lwp = get_thread_lwp (thread);
3877 int leave_all_stopped = * (int *) arg;
3880 if (lwp->resume == NULL)
3883 if (lwp->resume->kind == resume_stop)
3886 debug_printf ("resume_stop request for LWP %ld\n", lwpid_of (thread));
3891 debug_printf ("stopping LWP %ld\n", lwpid_of (thread));
3893 /* Stop the thread, and wait for the event asynchronously,
3894 through the event loop. */
3900 debug_printf ("already stopped LWP %ld\n",
3903 /* The LWP may have been stopped in an internal event that
3904 was not meant to be notified back to GDB (e.g., gdbserver
3905 breakpoint), so we should be reporting a stop event in
3908 /* If the thread already has a pending SIGSTOP, this is a
3909 no-op. Otherwise, something later will presumably resume
3910 the thread and this will cause it to cancel any pending
3911 operation, due to last_resume_kind == resume_stop. If
3912 the thread already has a pending status to report, we
3913 will still report it the next time we wait - see
3914 status_pending_p_callback. */
3916 /* If we already have a pending signal to report, then
3917 there's no need to queue a SIGSTOP, as this means we're
3918 midway through moving the LWP out of the jumppad, and we
3919 will report the pending signal as soon as that is
3921 if (lwp->pending_signals_to_report == NULL)
3925 /* For stop requests, we're done. */
3927 thread->last_status.kind = TARGET_WAITKIND_IGNORE;
3931 /* If this thread which is about to be resumed has a pending status,
3932 then don't resume any threads - we can just report the pending
3933 status. Make sure to queue any signals that would otherwise be
3934 sent. In all-stop mode, we do this decision based on if *any*
3935 thread has a pending status. If there's a thread that needs the
3936 step-over-breakpoint dance, then don't resume any other thread
3937 but that particular one. */
3938 leave_pending = (lwp->status_pending_p || leave_all_stopped);
3943 debug_printf ("resuming LWP %ld\n", lwpid_of (thread));
3945 step = (lwp->resume->kind == resume_step);
3946 linux_resume_one_lwp (lwp, step, lwp->resume->sig, NULL);
3951 debug_printf ("leaving LWP %ld stopped\n", lwpid_of (thread));
3953 /* If we have a new signal, enqueue the signal. */
3954 if (lwp->resume->sig != 0)
3956 struct pending_signals *p_sig;
3957 p_sig = xmalloc (sizeof (*p_sig));
3958 p_sig->prev = lwp->pending_signals;
3959 p_sig->signal = lwp->resume->sig;
3960 memset (&p_sig->info, 0, sizeof (siginfo_t));
3962 /* If this is the same signal we were previously stopped by,
3963 make sure to queue its siginfo. We can ignore the return
3964 value of ptrace; if it fails, we'll skip
3965 PTRACE_SETSIGINFO. */
3966 if (WIFSTOPPED (lwp->last_status)
3967 && WSTOPSIG (lwp->last_status) == lwp->resume->sig)
3968 ptrace (PTRACE_GETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0,
3971 lwp->pending_signals = p_sig;
3975 thread->last_status.kind = TARGET_WAITKIND_IGNORE;
3981 linux_resume (struct thread_resume *resume_info, size_t n)
3983 struct thread_resume_array array = { resume_info, n };
3984 struct thread_info *need_step_over = NULL;
3986 int leave_all_stopped;
3991 debug_printf ("linux_resume:\n");
3994 find_inferior (&all_threads, linux_set_resume_request, &array);
3996 /* If there is a thread which would otherwise be resumed, which has
3997 a pending status, then don't resume any threads - we can just
3998 report the pending status. Make sure to queue any signals that
3999 would otherwise be sent. In non-stop mode, we'll apply this
4000 logic to each thread individually. We consume all pending events
4001 before considering to start a step-over (in all-stop). */
4004 find_inferior (&all_threads, resume_status_pending_p, &any_pending);
4006 /* If there is a thread which would otherwise be resumed, which is
4007 stopped at a breakpoint that needs stepping over, then don't
4008 resume any threads - have it step over the breakpoint with all
4009 other threads stopped, then resume all threads again. Make sure
4010 to queue any signals that would otherwise be delivered or
4012 if (!any_pending && supports_breakpoints ())
4014 = (struct thread_info *) find_inferior (&all_threads,
4015 need_step_over_p, NULL);
4017 leave_all_stopped = (need_step_over != NULL || any_pending);
4021 if (need_step_over != NULL)
4022 debug_printf ("Not resuming all, need step over\n");
4023 else if (any_pending)
4024 debug_printf ("Not resuming, all-stop and found "
4025 "an LWP with pending status\n");
4027 debug_printf ("Resuming, no pending status or step over needed\n");
4030 /* Even if we're leaving threads stopped, queue all signals we'd
4031 otherwise deliver. */
4032 find_inferior (&all_threads, linux_resume_one_thread, &leave_all_stopped);
4035 start_step_over (get_thread_lwp (need_step_over));
4039 debug_printf ("linux_resume done\n");
4044 /* This function is called once per thread. We check the thread's
4045 last resume request, which will tell us whether to resume, step, or
4046 leave the thread stopped. Any signal the client requested to be
4047 delivered has already been enqueued at this point.
4049 If any thread that GDB wants running is stopped at an internal
4050 breakpoint that needs stepping over, we start a step-over operation
4051 on that particular thread, and leave all others stopped. */
4054 proceed_one_lwp (struct inferior_list_entry *entry, void *except)
4056 struct thread_info *thread = (struct thread_info *) entry;
4057 struct lwp_info *lwp = get_thread_lwp (thread);
4064 debug_printf ("proceed_one_lwp: lwp %ld\n", lwpid_of (thread));
4069 debug_printf (" LWP %ld already running\n", lwpid_of (thread));
4073 if (thread->last_resume_kind == resume_stop
4074 && thread->last_status.kind != TARGET_WAITKIND_IGNORE)
4077 debug_printf (" client wants LWP to remain %ld stopped\n",
4082 if (lwp->status_pending_p)
4085 debug_printf (" LWP %ld has pending status, leaving stopped\n",
4090 gdb_assert (lwp->suspended >= 0);
4095 debug_printf (" LWP %ld is suspended\n", lwpid_of (thread));
4099 if (thread->last_resume_kind == resume_stop
4100 && lwp->pending_signals_to_report == NULL
4101 && lwp->collecting_fast_tracepoint == 0)
4103 /* We haven't reported this LWP as stopped yet (otherwise, the
4104 last_status.kind check above would catch it, and we wouldn't
4105 reach here. This LWP may have been momentarily paused by a
4106 stop_all_lwps call while handling for example, another LWP's
4107 step-over. In that case, the pending expected SIGSTOP signal
4108 that was queued at vCont;t handling time will have already
4109 been consumed by wait_for_sigstop, and so we need to requeue
4110 another one here. Note that if the LWP already has a SIGSTOP
4111 pending, this is a no-op. */
4114 debug_printf ("Client wants LWP %ld to stop. "
4115 "Making sure it has a SIGSTOP pending\n",
4121 step = thread->last_resume_kind == resume_step;
4122 linux_resume_one_lwp (lwp, step, 0, NULL);
4127 unsuspend_and_proceed_one_lwp (struct inferior_list_entry *entry, void *except)
4129 struct thread_info *thread = (struct thread_info *) entry;
4130 struct lwp_info *lwp = get_thread_lwp (thread);
4136 gdb_assert (lwp->suspended >= 0);
4138 return proceed_one_lwp (entry, except);
4141 /* When we finish a step-over, set threads running again. If there's
4142 another thread that may need a step-over, now's the time to start
4143 it. Eventually, we'll move all threads past their breakpoints. */
4146 proceed_all_lwps (void)
4148 struct thread_info *need_step_over;
4150 /* If there is a thread which would otherwise be resumed, which is
4151 stopped at a breakpoint that needs stepping over, then don't
4152 resume any threads - have it step over the breakpoint with all
4153 other threads stopped, then resume all threads again. */
4155 if (supports_breakpoints ())
4158 = (struct thread_info *) find_inferior (&all_threads,
4159 need_step_over_p, NULL);
4161 if (need_step_over != NULL)
4164 debug_printf ("proceed_all_lwps: found "
4165 "thread %ld needing a step-over\n",
4166 lwpid_of (need_step_over));
4168 start_step_over (get_thread_lwp (need_step_over));
4174 debug_printf ("Proceeding, no step-over needed\n");
4176 find_inferior (&all_threads, proceed_one_lwp, NULL);
4179 /* Stopped LWPs that the client wanted to be running, that don't have
4180 pending statuses, are set to run again, except for EXCEPT, if not
4181 NULL. This undoes a stop_all_lwps call. */
4184 unstop_all_lwps (int unsuspend, struct lwp_info *except)
4190 debug_printf ("unstopping all lwps, except=(LWP %ld)\n",
4191 lwpid_of (get_lwp_thread (except)));
4193 debug_printf ("unstopping all lwps\n");
4197 find_inferior (&all_threads, unsuspend_and_proceed_one_lwp, except);
4199 find_inferior (&all_threads, proceed_one_lwp, except);
4203 debug_printf ("unstop_all_lwps done\n");
4209 #ifdef HAVE_LINUX_REGSETS
4211 #define use_linux_regsets 1
4213 /* Returns true if REGSET has been disabled. */
4216 regset_disabled (struct regsets_info *info, struct regset_info *regset)
4218 return (info->disabled_regsets != NULL
4219 && info->disabled_regsets[regset - info->regsets]);
4222 /* Disable REGSET. */
4225 disable_regset (struct regsets_info *info, struct regset_info *regset)
4229 dr_offset = regset - info->regsets;
4230 if (info->disabled_regsets == NULL)
4231 info->disabled_regsets = xcalloc (1, info->num_regsets);
4232 info->disabled_regsets[dr_offset] = 1;
4236 regsets_fetch_inferior_registers (struct regsets_info *regsets_info,
4237 struct regcache *regcache)
4239 struct regset_info *regset;
4240 int saw_general_regs = 0;
4244 regset = regsets_info->regsets;
4246 pid = lwpid_of (current_thread);
4247 while (regset->size >= 0)
4252 if (regset->size == 0 || regset_disabled (regsets_info, regset))
4258 buf = xmalloc (regset->size);
4260 nt_type = regset->nt_type;
4264 iov.iov_len = regset->size;
4265 data = (void *) &iov;
4271 res = ptrace (regset->get_request, pid,
4272 (PTRACE_TYPE_ARG3) (long) nt_type, data);
4274 res = ptrace (regset->get_request, pid, data, nt_type);
4280 /* If we get EIO on a regset, do not try it again for
4281 this process mode. */
4282 disable_regset (regsets_info, regset);
4289 sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d",
4294 else if (regset->type == GENERAL_REGS)
4295 saw_general_regs = 1;
4296 regset->store_function (regcache, buf);
4300 if (saw_general_regs)
4307 regsets_store_inferior_registers (struct regsets_info *regsets_info,
4308 struct regcache *regcache)
4310 struct regset_info *regset;
4311 int saw_general_regs = 0;
4315 regset = regsets_info->regsets;
4317 pid = lwpid_of (current_thread);
4318 while (regset->size >= 0)
4323 if (regset->size == 0 || regset_disabled (regsets_info, regset))
4329 buf = xmalloc (regset->size);
4331 /* First fill the buffer with the current register set contents,
4332 in case there are any items in the kernel's regset that are
4333 not in gdbserver's regcache. */
4335 nt_type = regset->nt_type;
4339 iov.iov_len = regset->size;
4340 data = (void *) &iov;
4346 res = ptrace (regset->get_request, pid,
4347 (PTRACE_TYPE_ARG3) (long) nt_type, data);
4349 res = ptrace (regset->get_request, pid, data, nt_type);
4354 /* Then overlay our cached registers on that. */
4355 regset->fill_function (regcache, buf);
4357 /* Only now do we write the register set. */
4359 res = ptrace (regset->set_request, pid,
4360 (PTRACE_TYPE_ARG3) (long) nt_type, data);
4362 res = ptrace (regset->set_request, pid, data, nt_type);
4370 /* If we get EIO on a regset, do not try it again for
4371 this process mode. */
4372 disable_regset (regsets_info, regset);
4376 else if (errno == ESRCH)
4378 /* At this point, ESRCH should mean the process is
4379 already gone, in which case we simply ignore attempts
4380 to change its registers. See also the related
4381 comment in linux_resume_one_lwp. */
4387 perror ("Warning: ptrace(regsets_store_inferior_registers)");
4390 else if (regset->type == GENERAL_REGS)
4391 saw_general_regs = 1;
4395 if (saw_general_regs)
4401 #else /* !HAVE_LINUX_REGSETS */
4403 #define use_linux_regsets 0
4404 #define regsets_fetch_inferior_registers(regsets_info, regcache) 1
4405 #define regsets_store_inferior_registers(regsets_info, regcache) 1
4409 /* Return 1 if register REGNO is supported by one of the regset ptrace
4410 calls or 0 if it has to be transferred individually. */
4413 linux_register_in_regsets (const struct regs_info *regs_info, int regno)
4415 unsigned char mask = 1 << (regno % 8);
4416 size_t index = regno / 8;
4418 return (use_linux_regsets
4419 && (regs_info->regset_bitmap == NULL
4420 || (regs_info->regset_bitmap[index] & mask) != 0));
4423 #ifdef HAVE_LINUX_USRREGS
4426 register_addr (const struct usrregs_info *usrregs, int regnum)
4430 if (regnum < 0 || regnum >= usrregs->num_regs)
4431 error ("Invalid register number %d.", regnum);
4433 addr = usrregs->regmap[regnum];
4438 /* Fetch one register. */
4440 fetch_register (const struct usrregs_info *usrregs,
4441 struct regcache *regcache, int regno)
4448 if (regno >= usrregs->num_regs)
4450 if ((*the_low_target.cannot_fetch_register) (regno))
4453 regaddr = register_addr (usrregs, regno);
4457 size = ((register_size (regcache->tdesc, regno)
4458 + sizeof (PTRACE_XFER_TYPE) - 1)
4459 & -sizeof (PTRACE_XFER_TYPE));
4460 buf = alloca (size);
4462 pid = lwpid_of (current_thread);
4463 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
4466 *(PTRACE_XFER_TYPE *) (buf + i) =
4467 ptrace (PTRACE_PEEKUSER, pid,
4468 /* Coerce to a uintptr_t first to avoid potential gcc warning
4469 of coercing an 8 byte integer to a 4 byte pointer. */
4470 (PTRACE_TYPE_ARG3) (uintptr_t) regaddr, (PTRACE_TYPE_ARG4) 0);
4471 regaddr += sizeof (PTRACE_XFER_TYPE);
4473 error ("reading register %d: %s", regno, strerror (errno));
4476 if (the_low_target.supply_ptrace_register)
4477 the_low_target.supply_ptrace_register (regcache, regno, buf);
4479 supply_register (regcache, regno, buf);
4482 /* Store one register. */
4484 store_register (const struct usrregs_info *usrregs,
4485 struct regcache *regcache, int regno)
4492 if (regno >= usrregs->num_regs)
4494 if ((*the_low_target.cannot_store_register) (regno))
4497 regaddr = register_addr (usrregs, regno);
4501 size = ((register_size (regcache->tdesc, regno)
4502 + sizeof (PTRACE_XFER_TYPE) - 1)
4503 & -sizeof (PTRACE_XFER_TYPE));
4504 buf = alloca (size);
4505 memset (buf, 0, size);
4507 if (the_low_target.collect_ptrace_register)
4508 the_low_target.collect_ptrace_register (regcache, regno, buf);
4510 collect_register (regcache, regno, buf);
4512 pid = lwpid_of (current_thread);
4513 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
4516 ptrace (PTRACE_POKEUSER, pid,
4517 /* Coerce to a uintptr_t first to avoid potential gcc warning
4518 about coercing an 8 byte integer to a 4 byte pointer. */
4519 (PTRACE_TYPE_ARG3) (uintptr_t) regaddr,
4520 (PTRACE_TYPE_ARG4) *(PTRACE_XFER_TYPE *) (buf + i));
4523 /* At this point, ESRCH should mean the process is
4524 already gone, in which case we simply ignore attempts
4525 to change its registers. See also the related
4526 comment in linux_resume_one_lwp. */
4530 if ((*the_low_target.cannot_store_register) (regno) == 0)
4531 error ("writing register %d: %s", regno, strerror (errno));
4533 regaddr += sizeof (PTRACE_XFER_TYPE);
4537 /* Fetch all registers, or just one, from the child process.
4538 If REGNO is -1, do this for all registers, skipping any that are
4539 assumed to have been retrieved by regsets_fetch_inferior_registers,
4540 unless ALL is non-zero.
4541 Otherwise, REGNO specifies which register (so we can save time). */
4543 usr_fetch_inferior_registers (const struct regs_info *regs_info,
4544 struct regcache *regcache, int regno, int all)
4546 struct usrregs_info *usr = regs_info->usrregs;
4550 for (regno = 0; regno < usr->num_regs; regno++)
4551 if (all || !linux_register_in_regsets (regs_info, regno))
4552 fetch_register (usr, regcache, regno);
4555 fetch_register (usr, regcache, regno);
4558 /* Store our register values back into the inferior.
4559 If REGNO is -1, do this for all registers, skipping any that are
4560 assumed to have been saved by regsets_store_inferior_registers,
4561 unless ALL is non-zero.
4562 Otherwise, REGNO specifies which register (so we can save time). */
4564 usr_store_inferior_registers (const struct regs_info *regs_info,
4565 struct regcache *regcache, int regno, int all)
4567 struct usrregs_info *usr = regs_info->usrregs;
4571 for (regno = 0; regno < usr->num_regs; regno++)
4572 if (all || !linux_register_in_regsets (regs_info, regno))
4573 store_register (usr, regcache, regno);
4576 store_register (usr, regcache, regno);
4579 #else /* !HAVE_LINUX_USRREGS */
4581 #define usr_fetch_inferior_registers(regs_info, regcache, regno, all) do {} while (0)
4582 #define usr_store_inferior_registers(regs_info, regcache, regno, all) do {} while (0)
4588 linux_fetch_registers (struct regcache *regcache, int regno)
4592 const struct regs_info *regs_info = (*the_low_target.regs_info) ();
4596 if (the_low_target.fetch_register != NULL
4597 && regs_info->usrregs != NULL)
4598 for (regno = 0; regno < regs_info->usrregs->num_regs; regno++)
4599 (*the_low_target.fetch_register) (regcache, regno);
4601 all = regsets_fetch_inferior_registers (regs_info->regsets_info, regcache);
4602 if (regs_info->usrregs != NULL)
4603 usr_fetch_inferior_registers (regs_info, regcache, -1, all);
4607 if (the_low_target.fetch_register != NULL
4608 && (*the_low_target.fetch_register) (regcache, regno))
4611 use_regsets = linux_register_in_regsets (regs_info, regno);
4613 all = regsets_fetch_inferior_registers (regs_info->regsets_info,
4615 if ((!use_regsets || all) && regs_info->usrregs != NULL)
4616 usr_fetch_inferior_registers (regs_info, regcache, regno, 1);
4621 linux_store_registers (struct regcache *regcache, int regno)
4625 const struct regs_info *regs_info = (*the_low_target.regs_info) ();
4629 all = regsets_store_inferior_registers (regs_info->regsets_info,
4631 if (regs_info->usrregs != NULL)
4632 usr_store_inferior_registers (regs_info, regcache, regno, all);
4636 use_regsets = linux_register_in_regsets (regs_info, regno);
4638 all = regsets_store_inferior_registers (regs_info->regsets_info,
4640 if ((!use_regsets || all) && regs_info->usrregs != NULL)
4641 usr_store_inferior_registers (regs_info, regcache, regno, 1);
4646 /* Copy LEN bytes from inferior's memory starting at MEMADDR
4647 to debugger memory starting at MYADDR. */
4650 linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
4652 int pid = lwpid_of (current_thread);
4653 register PTRACE_XFER_TYPE *buffer;
4654 register CORE_ADDR addr;
4661 /* Try using /proc. Don't bother for one word. */
4662 if (len >= 3 * sizeof (long))
4666 /* We could keep this file open and cache it - possibly one per
4667 thread. That requires some juggling, but is even faster. */
4668 sprintf (filename, "/proc/%d/mem", pid);
4669 fd = open (filename, O_RDONLY | O_LARGEFILE);
4673 /* If pread64 is available, use it. It's faster if the kernel
4674 supports it (only one syscall), and it's 64-bit safe even on
4675 32-bit platforms (for instance, SPARC debugging a SPARC64
4678 bytes = pread64 (fd, myaddr, len, memaddr);
4681 if (lseek (fd, memaddr, SEEK_SET) != -1)
4682 bytes = read (fd, myaddr, len);
4689 /* Some data was read, we'll try to get the rest with ptrace. */
4699 /* Round starting address down to longword boundary. */
4700 addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
4701 /* Round ending address up; get number of longwords that makes. */
4702 count = ((((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
4703 / sizeof (PTRACE_XFER_TYPE));
4704 /* Allocate buffer of that many longwords. */
4705 buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
4707 /* Read all the longwords */
4709 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
4711 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
4712 about coercing an 8 byte integer to a 4 byte pointer. */
4713 buffer[i] = ptrace (PTRACE_PEEKTEXT, pid,
4714 (PTRACE_TYPE_ARG3) (uintptr_t) addr,
4715 (PTRACE_TYPE_ARG4) 0);
4721 /* Copy appropriate bytes out of the buffer. */
4724 i *= sizeof (PTRACE_XFER_TYPE);
4725 i -= memaddr & (sizeof (PTRACE_XFER_TYPE) - 1);
4727 (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
4734 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
4735 memory at MEMADDR. On failure (cannot write to the inferior)
4736 returns the value of errno. Always succeeds if LEN is zero. */
4739 linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
4742 /* Round starting address down to longword boundary. */
4743 register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
4744 /* Round ending address up; get number of longwords that makes. */
4746 = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
4747 / sizeof (PTRACE_XFER_TYPE);
4749 /* Allocate buffer of that many longwords. */
4750 register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *)
4751 alloca (count * sizeof (PTRACE_XFER_TYPE));
4753 int pid = lwpid_of (current_thread);
4757 /* Zero length write always succeeds. */
4763 /* Dump up to four bytes. */
4764 unsigned int val = * (unsigned int *) myaddr;
4770 val = val & 0xffffff;
4771 debug_printf ("Writing %0*x to 0x%08lx\n", 2 * ((len < 4) ? len : 4),
4772 val, (long)memaddr);
4775 /* Fill start and end extra bytes of buffer with existing memory data. */
4778 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
4779 about coercing an 8 byte integer to a 4 byte pointer. */
4780 buffer[0] = ptrace (PTRACE_PEEKTEXT, pid,
4781 (PTRACE_TYPE_ARG3) (uintptr_t) addr,
4782 (PTRACE_TYPE_ARG4) 0);
4790 = ptrace (PTRACE_PEEKTEXT, pid,
4791 /* Coerce to a uintptr_t first to avoid potential gcc warning
4792 about coercing an 8 byte integer to a 4 byte pointer. */
4793 (PTRACE_TYPE_ARG3) (uintptr_t) (addr + (count - 1)
4794 * sizeof (PTRACE_XFER_TYPE)),
4795 (PTRACE_TYPE_ARG4) 0);
4800 /* Copy data to be written over corresponding part of buffer. */
4802 memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
4805 /* Write the entire buffer. */
4807 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
4810 ptrace (PTRACE_POKETEXT, pid,
4811 /* Coerce to a uintptr_t first to avoid potential gcc warning
4812 about coercing an 8 byte integer to a 4 byte pointer. */
4813 (PTRACE_TYPE_ARG3) (uintptr_t) addr,
4814 (PTRACE_TYPE_ARG4) buffer[i]);
4823 linux_look_up_symbols (void)
4825 #ifdef USE_THREAD_DB
4826 struct process_info *proc = current_process ();
4828 if (proc->private->thread_db != NULL)
4831 /* If the kernel supports tracing clones, then we don't need to
4832 use the magic thread event breakpoint to learn about
4834 thread_db_init (!linux_supports_traceclone ());
4839 linux_request_interrupt (void)
4841 extern unsigned long signal_pid;
4843 if (!ptid_equal (cont_thread, null_ptid)
4844 && !ptid_equal (cont_thread, minus_one_ptid))
4848 lwpid = lwpid_of (current_thread);
4849 kill_lwp (lwpid, SIGINT);
4852 kill_lwp (signal_pid, SIGINT);
4855 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
4856 to debugger memory starting at MYADDR. */
4859 linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len)
4861 char filename[PATH_MAX];
4863 int pid = lwpid_of (current_thread);
4865 xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
4867 fd = open (filename, O_RDONLY);
4871 if (offset != (CORE_ADDR) 0
4872 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
4875 n = read (fd, myaddr, len);
4882 /* These breakpoint and watchpoint related wrapper functions simply
4883 pass on the function call if the target has registered a
4884 corresponding function. */
4887 linux_supports_z_point_type (char z_type)
4889 return (the_low_target.supports_z_point_type != NULL
4890 && the_low_target.supports_z_point_type (z_type));
4894 linux_insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
4895 int size, struct raw_breakpoint *bp)
4897 if (the_low_target.insert_point != NULL)
4898 return the_low_target.insert_point (type, addr, size, bp);
4900 /* Unsupported (see target.h). */
4905 linux_remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
4906 int size, struct raw_breakpoint *bp)
4908 if (the_low_target.remove_point != NULL)
4909 return the_low_target.remove_point (type, addr, size, bp);
4911 /* Unsupported (see target.h). */
4916 linux_stopped_by_watchpoint (void)
4918 struct lwp_info *lwp = get_thread_lwp (current_thread);
4920 return lwp->stopped_by_watchpoint;
4924 linux_stopped_data_address (void)
4926 struct lwp_info *lwp = get_thread_lwp (current_thread);
4928 return lwp->stopped_data_address;
4931 #if defined(__UCLIBC__) && defined(HAS_NOMMU) \
4932 && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \
4933 && defined(PT_TEXT_END_ADDR)
4935 /* This is only used for targets that define PT_TEXT_ADDR,
4936 PT_DATA_ADDR and PT_TEXT_END_ADDR. If those are not defined, supposedly
4937 the target has different ways of acquiring this information, like
4940 /* Under uClinux, programs are loaded at non-zero offsets, which we need
4941 to tell gdb about. */
4944 linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p)
4946 unsigned long text, text_end, data;
4947 int pid = lwpid_of (get_thread_lwp (current_thread));
4951 text = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_TEXT_ADDR,
4952 (PTRACE_TYPE_ARG4) 0);
4953 text_end = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_TEXT_END_ADDR,
4954 (PTRACE_TYPE_ARG4) 0);
4955 data = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_DATA_ADDR,
4956 (PTRACE_TYPE_ARG4) 0);
4960 /* Both text and data offsets produced at compile-time (and so
4961 used by gdb) are relative to the beginning of the program,
4962 with the data segment immediately following the text segment.
4963 However, the actual runtime layout in memory may put the data
4964 somewhere else, so when we send gdb a data base-address, we
4965 use the real data base address and subtract the compile-time
4966 data base-address from it (which is just the length of the
4967 text segment). BSS immediately follows data in both
4970 *data_p = data - (text_end - text);
4979 linux_qxfer_osdata (const char *annex,
4980 unsigned char *readbuf, unsigned const char *writebuf,
4981 CORE_ADDR offset, int len)
4983 return linux_common_xfer_osdata (annex, readbuf, offset, len);
4986 /* Convert a native/host siginfo object, into/from the siginfo in the
4987 layout of the inferiors' architecture. */
4990 siginfo_fixup (siginfo_t *siginfo, void *inf_siginfo, int direction)
4994 if (the_low_target.siginfo_fixup != NULL)
4995 done = the_low_target.siginfo_fixup (siginfo, inf_siginfo, direction);
4997 /* If there was no callback, or the callback didn't do anything,
4998 then just do a straight memcpy. */
5002 memcpy (siginfo, inf_siginfo, sizeof (siginfo_t));
5004 memcpy (inf_siginfo, siginfo, sizeof (siginfo_t));
5009 linux_xfer_siginfo (const char *annex, unsigned char *readbuf,
5010 unsigned const char *writebuf, CORE_ADDR offset, int len)
5014 char inf_siginfo[sizeof (siginfo_t)];
5016 if (current_thread == NULL)
5019 pid = lwpid_of (current_thread);
5022 debug_printf ("%s siginfo for lwp %d.\n",
5023 readbuf != NULL ? "Reading" : "Writing",
5026 if (offset >= sizeof (siginfo))
5029 if (ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo) != 0)
5032 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
5033 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
5034 inferior with a 64-bit GDBSERVER should look the same as debugging it
5035 with a 32-bit GDBSERVER, we need to convert it. */
5036 siginfo_fixup (&siginfo, inf_siginfo, 0);
5038 if (offset + len > sizeof (siginfo))
5039 len = sizeof (siginfo) - offset;
5041 if (readbuf != NULL)
5042 memcpy (readbuf, inf_siginfo + offset, len);
5045 memcpy (inf_siginfo + offset, writebuf, len);
5047 /* Convert back to ptrace layout before flushing it out. */
5048 siginfo_fixup (&siginfo, inf_siginfo, 1);
5050 if (ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo) != 0)
5057 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
5058 so we notice when children change state; as the handler for the
5059 sigsuspend in my_waitpid. */
5062 sigchld_handler (int signo)
5064 int old_errno = errno;
5070 /* fprintf is not async-signal-safe, so call write
5072 if (write (2, "sigchld_handler\n",
5073 sizeof ("sigchld_handler\n") - 1) < 0)
5074 break; /* just ignore */
5078 if (target_is_async_p ())
5079 async_file_mark (); /* trigger a linux_wait */
5085 linux_supports_non_stop (void)
5091 linux_async (int enable)
5093 int previous = target_is_async_p ();
5096 debug_printf ("linux_async (%d), previous=%d\n",
5099 if (previous != enable)
5102 sigemptyset (&mask);
5103 sigaddset (&mask, SIGCHLD);
5105 sigprocmask (SIG_BLOCK, &mask, NULL);
5109 if (pipe (linux_event_pipe) == -1)
5111 linux_event_pipe[0] = -1;
5112 linux_event_pipe[1] = -1;
5113 sigprocmask (SIG_UNBLOCK, &mask, NULL);
5115 warning ("creating event pipe failed.");
5119 fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK);
5120 fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK);
5122 /* Register the event loop handler. */
5123 add_file_handler (linux_event_pipe[0],
5124 handle_target_event, NULL);
5126 /* Always trigger a linux_wait. */
5131 delete_file_handler (linux_event_pipe[0]);
5133 close (linux_event_pipe[0]);
5134 close (linux_event_pipe[1]);
5135 linux_event_pipe[0] = -1;
5136 linux_event_pipe[1] = -1;
5139 sigprocmask (SIG_UNBLOCK, &mask, NULL);
5146 linux_start_non_stop (int nonstop)
5148 /* Register or unregister from event-loop accordingly. */
5149 linux_async (nonstop);
5151 if (target_is_async_p () != (nonstop != 0))
5158 linux_supports_multi_process (void)
5164 linux_supports_disable_randomization (void)
5166 #ifdef HAVE_PERSONALITY
5174 linux_supports_agent (void)
5180 linux_supports_range_stepping (void)
5182 if (*the_low_target.supports_range_stepping == NULL)
5185 return (*the_low_target.supports_range_stepping) ();
5188 /* Enumerate spufs IDs for process PID. */
5190 spu_enumerate_spu_ids (long pid, unsigned char *buf, CORE_ADDR offset, int len)
5196 struct dirent *entry;
5198 sprintf (path, "/proc/%ld/fd", pid);
5199 dir = opendir (path);
5204 while ((entry = readdir (dir)) != NULL)
5210 fd = atoi (entry->d_name);
5214 sprintf (path, "/proc/%ld/fd/%d", pid, fd);
5215 if (stat (path, &st) != 0)
5217 if (!S_ISDIR (st.st_mode))
5220 if (statfs (path, &stfs) != 0)
5222 if (stfs.f_type != SPUFS_MAGIC)
5225 if (pos >= offset && pos + 4 <= offset + len)
5227 *(unsigned int *)(buf + pos - offset) = fd;
5237 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
5238 object type, using the /proc file system. */
5240 linux_qxfer_spu (const char *annex, unsigned char *readbuf,
5241 unsigned const char *writebuf,
5242 CORE_ADDR offset, int len)
5244 long pid = lwpid_of (current_thread);
5249 if (!writebuf && !readbuf)
5257 return spu_enumerate_spu_ids (pid, readbuf, offset, len);
5260 sprintf (buf, "/proc/%ld/fd/%s", pid, annex);
5261 fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
5266 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
5273 ret = write (fd, writebuf, (size_t) len);
5275 ret = read (fd, readbuf, (size_t) len);
5281 #if defined PT_GETDSBT || defined PTRACE_GETFDPIC
5282 struct target_loadseg
5284 /* Core address to which the segment is mapped. */
5286 /* VMA recorded in the program header. */
5288 /* Size of this segment in memory. */
5292 # if defined PT_GETDSBT
5293 struct target_loadmap
5295 /* Protocol version number, must be zero. */
5297 /* Pointer to the DSBT table, its size, and the DSBT index. */
5298 unsigned *dsbt_table;
5299 unsigned dsbt_size, dsbt_index;
5300 /* Number of segments in this map. */
5302 /* The actual memory map. */
5303 struct target_loadseg segs[/*nsegs*/];
5305 # define LINUX_LOADMAP PT_GETDSBT
5306 # define LINUX_LOADMAP_EXEC PTRACE_GETDSBT_EXEC
5307 # define LINUX_LOADMAP_INTERP PTRACE_GETDSBT_INTERP
5309 struct target_loadmap
5311 /* Protocol version number, must be zero. */
5313 /* Number of segments in this map. */
5315 /* The actual memory map. */
5316 struct target_loadseg segs[/*nsegs*/];
5318 # define LINUX_LOADMAP PTRACE_GETFDPIC
5319 # define LINUX_LOADMAP_EXEC PTRACE_GETFDPIC_EXEC
5320 # define LINUX_LOADMAP_INTERP PTRACE_GETFDPIC_INTERP
5324 linux_read_loadmap (const char *annex, CORE_ADDR offset,
5325 unsigned char *myaddr, unsigned int len)
5327 int pid = lwpid_of (current_thread);
5329 struct target_loadmap *data = NULL;
5330 unsigned int actual_length, copy_length;
5332 if (strcmp (annex, "exec") == 0)
5333 addr = (int) LINUX_LOADMAP_EXEC;
5334 else if (strcmp (annex, "interp") == 0)
5335 addr = (int) LINUX_LOADMAP_INTERP;
5339 if (ptrace (LINUX_LOADMAP, pid, addr, &data) != 0)
5345 actual_length = sizeof (struct target_loadmap)
5346 + sizeof (struct target_loadseg) * data->nsegs;
5348 if (offset < 0 || offset > actual_length)
5351 copy_length = actual_length - offset < len ? actual_length - offset : len;
5352 memcpy (myaddr, (char *) data + offset, copy_length);
5356 # define linux_read_loadmap NULL
5357 #endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */
5360 linux_process_qsupported (const char *query)
5362 if (the_low_target.process_qsupported != NULL)
5363 the_low_target.process_qsupported (query);
5367 linux_supports_tracepoints (void)
5369 if (*the_low_target.supports_tracepoints == NULL)
5372 return (*the_low_target.supports_tracepoints) ();
5376 linux_read_pc (struct regcache *regcache)
5378 if (the_low_target.get_pc == NULL)
5381 return (*the_low_target.get_pc) (regcache);
5385 linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
5387 gdb_assert (the_low_target.set_pc != NULL);
5389 (*the_low_target.set_pc) (regcache, pc);
5393 linux_thread_stopped (struct thread_info *thread)
5395 return get_thread_lwp (thread)->stopped;
5398 /* This exposes stop-all-threads functionality to other modules. */
5401 linux_pause_all (int freeze)
5403 stop_all_lwps (freeze, NULL);
5406 /* This exposes unstop-all-threads functionality to other gdbserver
5410 linux_unpause_all (int unfreeze)
5412 unstop_all_lwps (unfreeze, NULL);
5416 linux_prepare_to_access_memory (void)
5418 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
5421 linux_pause_all (1);
5426 linux_done_accessing_memory (void)
5428 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
5431 linux_unpause_all (1);
5435 linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr,
5436 CORE_ADDR collector,
5439 CORE_ADDR *jump_entry,
5440 CORE_ADDR *trampoline,
5441 ULONGEST *trampoline_size,
5442 unsigned char *jjump_pad_insn,
5443 ULONGEST *jjump_pad_insn_size,
5444 CORE_ADDR *adjusted_insn_addr,
5445 CORE_ADDR *adjusted_insn_addr_end,
5448 return (*the_low_target.install_fast_tracepoint_jump_pad)
5449 (tpoint, tpaddr, collector, lockaddr, orig_size,
5450 jump_entry, trampoline, trampoline_size,
5451 jjump_pad_insn, jjump_pad_insn_size,
5452 adjusted_insn_addr, adjusted_insn_addr_end,
5456 static struct emit_ops *
5457 linux_emit_ops (void)
5459 if (the_low_target.emit_ops != NULL)
5460 return (*the_low_target.emit_ops) ();
5466 linux_get_min_fast_tracepoint_insn_len (void)
5468 return (*the_low_target.get_min_fast_tracepoint_insn_len) ();
5471 /* Extract &phdr and num_phdr in the inferior. Return 0 on success. */
5474 get_phdr_phnum_from_proc_auxv (const int pid, const int is_elf64,
5475 CORE_ADDR *phdr_memaddr, int *num_phdr)
5477 char filename[PATH_MAX];
5479 const int auxv_size = is_elf64
5480 ? sizeof (Elf64_auxv_t) : sizeof (Elf32_auxv_t);
5481 char buf[sizeof (Elf64_auxv_t)]; /* The larger of the two. */
5483 xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
5485 fd = open (filename, O_RDONLY);
5491 while (read (fd, buf, auxv_size) == auxv_size
5492 && (*phdr_memaddr == 0 || *num_phdr == 0))
5496 Elf64_auxv_t *const aux = (Elf64_auxv_t *) buf;
5498 switch (aux->a_type)
5501 *phdr_memaddr = aux->a_un.a_val;
5504 *num_phdr = aux->a_un.a_val;
5510 Elf32_auxv_t *const aux = (Elf32_auxv_t *) buf;
5512 switch (aux->a_type)
5515 *phdr_memaddr = aux->a_un.a_val;
5518 *num_phdr = aux->a_un.a_val;
5526 if (*phdr_memaddr == 0 || *num_phdr == 0)
5528 warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: "
5529 "phdr_memaddr = %ld, phdr_num = %d",
5530 (long) *phdr_memaddr, *num_phdr);
5537 /* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */
5540 get_dynamic (const int pid, const int is_elf64)
5542 CORE_ADDR phdr_memaddr, relocation;
5544 unsigned char *phdr_buf;
5545 const int phdr_size = is_elf64 ? sizeof (Elf64_Phdr) : sizeof (Elf32_Phdr);
5547 if (get_phdr_phnum_from_proc_auxv (pid, is_elf64, &phdr_memaddr, &num_phdr))
5550 gdb_assert (num_phdr < 100); /* Basic sanity check. */
5551 phdr_buf = alloca (num_phdr * phdr_size);
5553 if (linux_read_memory (phdr_memaddr, phdr_buf, num_phdr * phdr_size))
5556 /* Compute relocation: it is expected to be 0 for "regular" executables,
5557 non-zero for PIE ones. */
5559 for (i = 0; relocation == -1 && i < num_phdr; i++)
5562 Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size);
5564 if (p->p_type == PT_PHDR)
5565 relocation = phdr_memaddr - p->p_vaddr;
5569 Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size);
5571 if (p->p_type == PT_PHDR)
5572 relocation = phdr_memaddr - p->p_vaddr;
5575 if (relocation == -1)
5577 /* PT_PHDR is optional, but necessary for PIE in general. Fortunately
5578 any real world executables, including PIE executables, have always
5579 PT_PHDR present. PT_PHDR is not present in some shared libraries or
5580 in fpc (Free Pascal 2.4) binaries but neither of those have a need for
5581 or present DT_DEBUG anyway (fpc binaries are statically linked).
5583 Therefore if there exists DT_DEBUG there is always also PT_PHDR.
5585 GDB could find RELOCATION also from AT_ENTRY - e_entry. */
5590 for (i = 0; i < num_phdr; i++)
5594 Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size);
5596 if (p->p_type == PT_DYNAMIC)
5597 return p->p_vaddr + relocation;
5601 Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size);
5603 if (p->p_type == PT_DYNAMIC)
5604 return p->p_vaddr + relocation;
5611 /* Return &_r_debug in the inferior, or -1 if not present. Return value
5612 can be 0 if the inferior does not yet have the library list initialized.
5613 We look for DT_MIPS_RLD_MAP first. MIPS executables use this instead of
5614 DT_DEBUG, although they sometimes contain an unused DT_DEBUG entry too. */
5617 get_r_debug (const int pid, const int is_elf64)
5619 CORE_ADDR dynamic_memaddr;
5620 const int dyn_size = is_elf64 ? sizeof (Elf64_Dyn) : sizeof (Elf32_Dyn);
5621 unsigned char buf[sizeof (Elf64_Dyn)]; /* The larger of the two. */
5624 dynamic_memaddr = get_dynamic (pid, is_elf64);
5625 if (dynamic_memaddr == 0)
5628 while (linux_read_memory (dynamic_memaddr, buf, dyn_size) == 0)
5632 Elf64_Dyn *const dyn = (Elf64_Dyn *) buf;
5633 #ifdef DT_MIPS_RLD_MAP
5637 unsigned char buf[sizeof (Elf64_Xword)];
5641 if (dyn->d_tag == DT_MIPS_RLD_MAP)
5643 if (linux_read_memory (dyn->d_un.d_val,
5644 rld_map.buf, sizeof (rld_map.buf)) == 0)
5649 #endif /* DT_MIPS_RLD_MAP */
5651 if (dyn->d_tag == DT_DEBUG && map == -1)
5652 map = dyn->d_un.d_val;
5654 if (dyn->d_tag == DT_NULL)
5659 Elf32_Dyn *const dyn = (Elf32_Dyn *) buf;
5660 #ifdef DT_MIPS_RLD_MAP
5664 unsigned char buf[sizeof (Elf32_Word)];
5668 if (dyn->d_tag == DT_MIPS_RLD_MAP)
5670 if (linux_read_memory (dyn->d_un.d_val,
5671 rld_map.buf, sizeof (rld_map.buf)) == 0)
5676 #endif /* DT_MIPS_RLD_MAP */
5678 if (dyn->d_tag == DT_DEBUG && map == -1)
5679 map = dyn->d_un.d_val;
5681 if (dyn->d_tag == DT_NULL)
5685 dynamic_memaddr += dyn_size;
5691 /* Read one pointer from MEMADDR in the inferior. */
5694 read_one_ptr (CORE_ADDR memaddr, CORE_ADDR *ptr, int ptr_size)
5698 /* Go through a union so this works on either big or little endian
5699 hosts, when the inferior's pointer size is smaller than the size
5700 of CORE_ADDR. It is assumed the inferior's endianness is the
5701 same of the superior's. */
5704 CORE_ADDR core_addr;
5709 ret = linux_read_memory (memaddr, &addr.uc, ptr_size);
5712 if (ptr_size == sizeof (CORE_ADDR))
5713 *ptr = addr.core_addr;
5714 else if (ptr_size == sizeof (unsigned int))
5717 gdb_assert_not_reached ("unhandled pointer size");
5722 struct link_map_offsets
5724 /* Offset and size of r_debug.r_version. */
5725 int r_version_offset;
5727 /* Offset and size of r_debug.r_map. */
5730 /* Offset to l_addr field in struct link_map. */
5733 /* Offset to l_name field in struct link_map. */
5736 /* Offset to l_ld field in struct link_map. */
5739 /* Offset to l_next field in struct link_map. */
5742 /* Offset to l_prev field in struct link_map. */
5746 /* Construct qXfer:libraries-svr4:read reply. */
5749 linux_qxfer_libraries_svr4 (const char *annex, unsigned char *readbuf,
5750 unsigned const char *writebuf,
5751 CORE_ADDR offset, int len)
5754 unsigned document_len;
5755 struct process_info_private *const priv = current_process ()->private;
5756 char filename[PATH_MAX];
5759 static const struct link_map_offsets lmo_32bit_offsets =
5761 0, /* r_version offset. */
5762 4, /* r_debug.r_map offset. */
5763 0, /* l_addr offset in link_map. */
5764 4, /* l_name offset in link_map. */
5765 8, /* l_ld offset in link_map. */
5766 12, /* l_next offset in link_map. */
5767 16 /* l_prev offset in link_map. */
5770 static const struct link_map_offsets lmo_64bit_offsets =
5772 0, /* r_version offset. */
5773 8, /* r_debug.r_map offset. */
5774 0, /* l_addr offset in link_map. */
5775 8, /* l_name offset in link_map. */
5776 16, /* l_ld offset in link_map. */
5777 24, /* l_next offset in link_map. */
5778 32 /* l_prev offset in link_map. */
5780 const struct link_map_offsets *lmo;
5781 unsigned int machine;
5783 CORE_ADDR lm_addr = 0, lm_prev = 0;
5784 int allocated = 1024;
5786 CORE_ADDR l_name, l_addr, l_ld, l_next, l_prev;
5787 int header_done = 0;
5789 if (writebuf != NULL)
5791 if (readbuf == NULL)
5794 pid = lwpid_of (current_thread);
5795 xsnprintf (filename, sizeof filename, "/proc/%d/exe", pid);
5796 is_elf64 = elf_64_file_p (filename, &machine);
5797 lmo = is_elf64 ? &lmo_64bit_offsets : &lmo_32bit_offsets;
5798 ptr_size = is_elf64 ? 8 : 4;
5800 while (annex[0] != '\0')
5806 sep = strchr (annex, '=');
5811 if (len == 5 && strncmp (annex, "start", 5) == 0)
5813 else if (len == 4 && strncmp (annex, "prev", 4) == 0)
5817 annex = strchr (sep, ';');
5824 annex = decode_address_to_semicolon (addrp, sep + 1);
5831 if (priv->r_debug == 0)
5832 priv->r_debug = get_r_debug (pid, is_elf64);
5834 /* We failed to find DT_DEBUG. Such situation will not change
5835 for this inferior - do not retry it. Report it to GDB as
5836 E01, see for the reasons at the GDB solib-svr4.c side. */
5837 if (priv->r_debug == (CORE_ADDR) -1)
5840 if (priv->r_debug != 0)
5842 if (linux_read_memory (priv->r_debug + lmo->r_version_offset,
5843 (unsigned char *) &r_version,
5844 sizeof (r_version)) != 0
5847 warning ("unexpected r_debug version %d", r_version);
5849 else if (read_one_ptr (priv->r_debug + lmo->r_map_offset,
5850 &lm_addr, ptr_size) != 0)
5852 warning ("unable to read r_map from 0x%lx",
5853 (long) priv->r_debug + lmo->r_map_offset);
5858 document = xmalloc (allocated);
5859 strcpy (document, "<library-list-svr4 version=\"1.0\"");
5860 p = document + strlen (document);
5863 && read_one_ptr (lm_addr + lmo->l_name_offset,
5864 &l_name, ptr_size) == 0
5865 && read_one_ptr (lm_addr + lmo->l_addr_offset,
5866 &l_addr, ptr_size) == 0
5867 && read_one_ptr (lm_addr + lmo->l_ld_offset,
5868 &l_ld, ptr_size) == 0
5869 && read_one_ptr (lm_addr + lmo->l_prev_offset,
5870 &l_prev, ptr_size) == 0
5871 && read_one_ptr (lm_addr + lmo->l_next_offset,
5872 &l_next, ptr_size) == 0)
5874 unsigned char libname[PATH_MAX];
5876 if (lm_prev != l_prev)
5878 warning ("Corrupted shared library list: 0x%lx != 0x%lx",
5879 (long) lm_prev, (long) l_prev);
5883 /* Ignore the first entry even if it has valid name as the first entry
5884 corresponds to the main executable. The first entry should not be
5885 skipped if the dynamic loader was loaded late by a static executable
5886 (see solib-svr4.c parameter ignore_first). But in such case the main
5887 executable does not have PT_DYNAMIC present and this function already
5888 exited above due to failed get_r_debug. */
5891 sprintf (p, " main-lm=\"0x%lx\"", (unsigned long) lm_addr);
5896 /* Not checking for error because reading may stop before
5897 we've got PATH_MAX worth of characters. */
5899 linux_read_memory (l_name, libname, sizeof (libname) - 1);
5900 libname[sizeof (libname) - 1] = '\0';
5901 if (libname[0] != '\0')
5903 /* 6x the size for xml_escape_text below. */
5904 size_t len = 6 * strlen ((char *) libname);
5909 /* Terminate `<library-list-svr4'. */
5914 while (allocated < p - document + len + 200)
5916 /* Expand to guarantee sufficient storage. */
5917 uintptr_t document_len = p - document;
5919 document = xrealloc (document, 2 * allocated);
5921 p = document + document_len;
5924 name = xml_escape_text ((char *) libname);
5925 p += sprintf (p, "<library name=\"%s\" lm=\"0x%lx\" "
5926 "l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>",
5927 name, (unsigned long) lm_addr,
5928 (unsigned long) l_addr, (unsigned long) l_ld);
5939 /* Empty list; terminate `<library-list-svr4'. */
5943 strcpy (p, "</library-list-svr4>");
5945 document_len = strlen (document);
5946 if (offset < document_len)
5947 document_len -= offset;
5950 if (len > document_len)
5953 memcpy (readbuf, document + offset, len);
5959 #ifdef HAVE_LINUX_BTRACE
5961 /* See to_enable_btrace target method. */
5963 static struct btrace_target_info *
5964 linux_low_enable_btrace (ptid_t ptid)
5966 struct btrace_target_info *tinfo;
5968 tinfo = linux_enable_btrace (ptid);
5972 struct thread_info *thread = find_thread_ptid (ptid);
5973 struct regcache *regcache = get_thread_regcache (thread, 0);
5975 tinfo->ptr_bits = register_size (regcache->tdesc, 0) * 8;
5981 /* See to_disable_btrace target method. */
5984 linux_low_disable_btrace (struct btrace_target_info *tinfo)
5986 enum btrace_error err;
5988 err = linux_disable_btrace (tinfo);
5989 return (err == BTRACE_ERR_NONE ? 0 : -1);
5992 /* See to_read_btrace target method. */
5995 linux_low_read_btrace (struct btrace_target_info *tinfo, struct buffer *buffer,
5998 VEC (btrace_block_s) *btrace;
5999 struct btrace_block *block;
6000 enum btrace_error err;
6004 err = linux_read_btrace (&btrace, tinfo, type);
6005 if (err != BTRACE_ERR_NONE)
6007 if (err == BTRACE_ERR_OVERFLOW)
6008 buffer_grow_str0 (buffer, "E.Overflow.");
6010 buffer_grow_str0 (buffer, "E.Generic Error.");
6015 buffer_grow_str (buffer, "<!DOCTYPE btrace SYSTEM \"btrace.dtd\">\n");
6016 buffer_grow_str (buffer, "<btrace version=\"1.0\">\n");
6018 for (i = 0; VEC_iterate (btrace_block_s, btrace, i, block); i++)
6019 buffer_xml_printf (buffer, "<block begin=\"0x%s\" end=\"0x%s\"/>\n",
6020 paddress (block->begin), paddress (block->end));
6022 buffer_grow_str0 (buffer, "</btrace>\n");
6024 VEC_free (btrace_block_s, btrace);
6028 #endif /* HAVE_LINUX_BTRACE */
6030 static struct target_ops linux_target_ops = {
6031 linux_create_inferior,
6040 linux_fetch_registers,
6041 linux_store_registers,
6042 linux_prepare_to_access_memory,
6043 linux_done_accessing_memory,
6046 linux_look_up_symbols,
6047 linux_request_interrupt,
6049 linux_supports_z_point_type,
6052 linux_stopped_by_watchpoint,
6053 linux_stopped_data_address,
6054 #if defined(__UCLIBC__) && defined(HAS_NOMMU) \
6055 && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \
6056 && defined(PT_TEXT_END_ADDR)
6061 #ifdef USE_THREAD_DB
6062 thread_db_get_tls_address,
6067 hostio_last_error_from_errno,
6070 linux_supports_non_stop,
6072 linux_start_non_stop,
6073 linux_supports_multi_process,
6074 #ifdef USE_THREAD_DB
6075 thread_db_handle_monitor_command,
6079 linux_common_core_of_thread,
6081 linux_process_qsupported,
6082 linux_supports_tracepoints,
6085 linux_thread_stopped,
6089 linux_cancel_breakpoints,
6090 linux_stabilize_threads,
6091 linux_install_fast_tracepoint_jump_pad,
6093 linux_supports_disable_randomization,
6094 linux_get_min_fast_tracepoint_insn_len,
6095 linux_qxfer_libraries_svr4,
6096 linux_supports_agent,
6097 #ifdef HAVE_LINUX_BTRACE
6098 linux_supports_btrace,
6099 linux_low_enable_btrace,
6100 linux_low_disable_btrace,
6101 linux_low_read_btrace,
6108 linux_supports_range_stepping,
6112 linux_init_signals ()
6114 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
6115 to find what the cancel signal actually is. */
6116 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
6117 signal (__SIGRTMIN+1, SIG_IGN);
6121 #ifdef HAVE_LINUX_REGSETS
6123 initialize_regsets_info (struct regsets_info *info)
6125 for (info->num_regsets = 0;
6126 info->regsets[info->num_regsets].size >= 0;
6127 info->num_regsets++)
6133 initialize_low (void)
6135 struct sigaction sigchld_action;
6136 memset (&sigchld_action, 0, sizeof (sigchld_action));
6137 set_target_ops (&linux_target_ops);
6138 set_breakpoint_data (the_low_target.breakpoint,
6139 the_low_target.breakpoint_len);
6140 linux_init_signals ();
6141 linux_ptrace_init_warnings ();
6143 sigchld_action.sa_handler = sigchld_handler;
6144 sigemptyset (&sigchld_action.sa_mask);
6145 sigchld_action.sa_flags = SA_RESTART;
6146 sigaction (SIGCHLD, &sigchld_action, NULL);
6148 initialize_low_arch ();