1 /* Low level interface to ptrace, for the remote server for GDB.
2 Copyright (C) 1995-1996, 1998-2012 Free Software Foundation, Inc.
4 This file is part of GDB.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>. */
20 #include "linux-low.h"
21 #include "linux-osdata.h"
26 #include <sys/param.h>
27 #include <sys/ptrace.h>
28 #include "linux-ptrace.h"
29 #include "linux-procfs.h"
31 #include <sys/ioctl.h>
37 #include <sys/syscall.h>
41 #include <sys/types.h>
47 /* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h
48 then ELFMAG0 will have been defined. If it didn't get included by
49 gdb_proc_service.h then including it will likely introduce a duplicate
50 definition of elf_fpregset_t. */
55 #define SPUFS_MAGIC 0x23c9b64e
58 #ifdef HAVE_PERSONALITY
59 # include <sys/personality.h>
60 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
61 # define ADDR_NO_RANDOMIZE 0x0040000
70 #define W_STOPCODE(sig) ((sig) << 8 | 0x7f)
73 /* This is the kernel's hard limit. Not to be confused with
80 #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
81 /* PTRACE_TEXT_ADDR and friends. */
82 #include <asm/ptrace.h>
87 #ifndef HAVE_ELF32_AUXV_T
88 /* Copied from glibc's elf.h. */
91 uint32_t a_type; /* Entry type */
94 uint32_t a_val; /* Integer value */
95 /* We use to have pointer elements added here. We cannot do that,
96 though, since it does not work when using 32-bit definitions
97 on 64-bit platforms and vice versa. */
102 #ifndef HAVE_ELF64_AUXV_T
103 /* Copied from glibc's elf.h. */
106 uint64_t a_type; /* Entry type */
109 uint64_t a_val; /* Integer value */
110 /* We use to have pointer elements added here. We cannot do that,
111 though, since it does not work when using 32-bit definitions
112 on 64-bit platforms and vice versa. */
117 /* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
118 representation of the thread ID.
120 ``all_lwps'' is keyed by the process ID - which on Linux is (presently)
121 the same as the LWP ID.
123 ``all_processes'' is keyed by the "overall process ID", which
124 GNU/Linux calls tgid, "thread group ID". */
126 struct inferior_list all_lwps;
128 /* A list of all unknown processes which receive stop signals. Some
129 other process will presumably claim each of these as forked
130 children momentarily. */
132 struct simple_pid_list
134 /* The process ID. */
137 /* The status as reported by waitpid. */
141 struct simple_pid_list *next;
143 struct simple_pid_list *stopped_pids;
145 /* Trivial list manipulation functions to keep track of a list of new
146 stopped processes. */
149 add_to_pid_list (struct simple_pid_list **listp, int pid, int status)
151 struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list));
154 new_pid->status = status;
155 new_pid->next = *listp;
160 pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp)
162 struct simple_pid_list **p;
164 for (p = listp; *p != NULL; p = &(*p)->next)
165 if ((*p)->pid == pid)
167 struct simple_pid_list *next = (*p)->next;
169 *statusp = (*p)->status;
177 enum stopping_threads_kind
179 /* Not stopping threads presently. */
180 NOT_STOPPING_THREADS,
182 /* Stopping threads. */
185 /* Stopping and suspending threads. */
186 STOPPING_AND_SUSPENDING_THREADS
189 /* This is set while stop_all_lwps is in effect. */
190 enum stopping_threads_kind stopping_threads = NOT_STOPPING_THREADS;
192 /* FIXME make into a target method? */
193 int using_threads = 1;
195 /* True if we're presently stabilizing threads (moving them out of
197 static int stabilizing_threads;
199 /* This flag is true iff we've just created or attached to our first
200 inferior but it has not stopped yet. As soon as it does, we need
201 to call the low target's arch_setup callback. Doing this only on
202 the first inferior avoids reinializing the architecture on every
203 inferior, and avoids messing with the register caches of the
204 already running inferiors. NOTE: this assumes all inferiors under
205 control of gdbserver have the same architecture. */
206 static int new_inferior;
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 (ptid_t ptid, int *wstat, int options);
214 static void *add_lwp (ptid_t ptid);
215 static int linux_stopped_by_watchpoint (void);
216 static void mark_lwp_dead (struct lwp_info *lwp, int wstat);
217 static void proceed_all_lwps (void);
218 static int finish_step_over (struct lwp_info *lwp);
219 static CORE_ADDR get_stop_pc (struct lwp_info *lwp);
220 static int kill_lwp (unsigned long lwpid, int signo);
221 static void linux_enable_event_reporting (int pid);
223 /* True if the low target can hardware single-step. Such targets
224 don't need a BREAKPOINT_REINSERT_ADDR callback. */
227 can_hardware_single_step (void)
229 return (the_low_target.breakpoint_reinsert_addr == NULL);
232 /* True if the low target supports memory breakpoints. If so, we'll
233 have a GET_PC implementation. */
236 supports_breakpoints (void)
238 return (the_low_target.get_pc != NULL);
241 /* Returns true if this target can support fast tracepoints. This
242 does not mean that the in-process agent has been loaded in the
246 supports_fast_tracepoints (void)
248 return the_low_target.install_fast_tracepoint_jump_pad != NULL;
251 struct pending_signals
255 struct pending_signals *prev;
258 #ifdef HAVE_LINUX_REGSETS
259 static char *disabled_regsets;
260 static int num_regsets;
263 /* The read/write ends of the pipe registered as waitable file in the
265 static int linux_event_pipe[2] = { -1, -1 };
267 /* True if we're currently in async mode. */
268 #define target_is_async_p() (linux_event_pipe[0] != -1)
270 static void send_sigstop (struct lwp_info *lwp);
271 static void wait_for_sigstop (struct inferior_list_entry *entry);
273 /* Return non-zero if HEADER is a 64-bit ELF file. */
276 elf_64_header_p (const Elf64_Ehdr *header, unsigned int *machine)
278 if (header->e_ident[EI_MAG0] == ELFMAG0
279 && header->e_ident[EI_MAG1] == ELFMAG1
280 && header->e_ident[EI_MAG2] == ELFMAG2
281 && header->e_ident[EI_MAG3] == ELFMAG3)
283 *machine = header->e_machine;
284 return header->e_ident[EI_CLASS] == ELFCLASS64;
291 /* Return non-zero if FILE is a 64-bit ELF file,
292 zero if the file is not a 64-bit ELF file,
293 and -1 if the file is not accessible or doesn't exist. */
296 elf_64_file_p (const char *file, unsigned int *machine)
301 fd = open (file, O_RDONLY);
305 if (read (fd, &header, sizeof (header)) != sizeof (header))
312 return elf_64_header_p (&header, machine);
315 /* Accepts an integer PID; Returns true if the executable PID is
316 running is a 64-bit ELF file.. */
319 linux_pid_exe_is_elf_64_file (int pid, unsigned int *machine)
321 char file[MAXPATHLEN];
323 sprintf (file, "/proc/%d/exe", pid);
324 return elf_64_file_p (file, machine);
328 delete_lwp (struct lwp_info *lwp)
330 remove_thread (get_lwp_thread (lwp));
331 remove_inferior (&all_lwps, &lwp->head);
332 free (lwp->arch_private);
336 /* Add a process to the common process list, and set its private
339 static struct process_info *
340 linux_add_process (int pid, int attached)
342 struct process_info *proc;
344 /* Is this the first process? If so, then set the arch. */
345 if (all_processes.head == NULL)
348 proc = add_process (pid, attached);
349 proc->private = xcalloc (1, sizeof (*proc->private));
351 if (the_low_target.new_process != NULL)
352 proc->private->arch_private = the_low_target.new_process ();
357 /* Wrapper function for waitpid which handles EINTR, and emulates
358 __WALL for systems where that is not available. */
361 my_waitpid (int pid, int *status, int flags)
366 fprintf (stderr, "my_waitpid (%d, 0x%x)\n", pid, flags);
370 sigset_t block_mask, org_mask, wake_mask;
373 wnohang = (flags & WNOHANG) != 0;
374 flags &= ~(__WALL | __WCLONE);
377 /* Block all signals while here. This avoids knowing about
378 LinuxThread's signals. */
379 sigfillset (&block_mask);
380 sigprocmask (SIG_BLOCK, &block_mask, &org_mask);
382 /* ... except during the sigsuspend below. */
383 sigemptyset (&wake_mask);
387 /* Since all signals are blocked, there's no need to check
389 ret = waitpid (pid, status, flags);
392 if (ret == -1 && out_errno != ECHILD)
397 if (flags & __WCLONE)
399 /* We've tried both flavors now. If WNOHANG is set,
400 there's nothing else to do, just bail out. */
405 fprintf (stderr, "blocking\n");
407 /* Block waiting for signals. */
408 sigsuspend (&wake_mask);
414 sigprocmask (SIG_SETMASK, &org_mask, NULL);
419 ret = waitpid (pid, status, flags);
420 while (ret == -1 && errno == EINTR);
425 fprintf (stderr, "my_waitpid (%d, 0x%x): status(%x), %d\n",
426 pid, flags, status ? *status : -1, ret);
432 /* Handle a GNU/Linux extended wait response. If we see a clone
433 event, we need to add the new LWP to our list (and not report the
434 trap to higher layers). */
437 handle_extended_wait (struct lwp_info *event_child, int wstat)
439 int event = wstat >> 16;
440 struct lwp_info *new_lwp;
442 if (event == PTRACE_EVENT_CLONE)
445 unsigned long new_pid;
448 ptrace (PTRACE_GETEVENTMSG, lwpid_of (event_child), 0, &new_pid);
450 /* If we haven't already seen the new PID stop, wait for it now. */
451 if (!pull_pid_from_list (&stopped_pids, new_pid, &status))
453 /* The new child has a pending SIGSTOP. We can't affect it until it
454 hits the SIGSTOP, but we're already attached. */
456 ret = my_waitpid (new_pid, &status, __WALL);
459 perror_with_name ("waiting for new child");
460 else if (ret != new_pid)
461 warning ("wait returned unexpected PID %d", ret);
462 else if (!WIFSTOPPED (status))
463 warning ("wait returned unexpected status 0x%x", status);
466 linux_enable_event_reporting (new_pid);
468 ptid = ptid_build (pid_of (event_child), new_pid, 0);
469 new_lwp = (struct lwp_info *) add_lwp (ptid);
470 add_thread (ptid, new_lwp);
472 /* Either we're going to immediately resume the new thread
473 or leave it stopped. linux_resume_one_lwp is a nop if it
474 thinks the thread is currently running, so set this first
475 before calling linux_resume_one_lwp. */
476 new_lwp->stopped = 1;
478 /* If we're suspending all threads, leave this one suspended
480 if (stopping_threads == STOPPING_AND_SUSPENDING_THREADS)
481 new_lwp->suspended = 1;
483 /* Normally we will get the pending SIGSTOP. But in some cases
484 we might get another signal delivered to the group first.
485 If we do get another signal, be sure not to lose it. */
486 if (WSTOPSIG (status) == SIGSTOP)
488 if (stopping_threads != NOT_STOPPING_THREADS)
489 new_lwp->stop_pc = get_stop_pc (new_lwp);
491 linux_resume_one_lwp (new_lwp, 0, 0, NULL);
495 new_lwp->stop_expected = 1;
497 if (stopping_threads != NOT_STOPPING_THREADS)
499 new_lwp->stop_pc = get_stop_pc (new_lwp);
500 new_lwp->status_pending_p = 1;
501 new_lwp->status_pending = status;
504 /* Pass the signal on. This is what GDB does - except
505 shouldn't we really report it instead? */
506 linux_resume_one_lwp (new_lwp, 0, WSTOPSIG (status), NULL);
509 /* Always resume the current thread. If we are stopping
510 threads, it will have a pending SIGSTOP; we may as well
512 linux_resume_one_lwp (event_child, event_child->stepping, 0, NULL);
516 /* Return the PC as read from the regcache of LWP, without any
520 get_pc (struct lwp_info *lwp)
522 struct thread_info *saved_inferior;
523 struct regcache *regcache;
526 if (the_low_target.get_pc == NULL)
529 saved_inferior = current_inferior;
530 current_inferior = get_lwp_thread (lwp);
532 regcache = get_thread_regcache (current_inferior, 1);
533 pc = (*the_low_target.get_pc) (regcache);
536 fprintf (stderr, "pc is 0x%lx\n", (long) pc);
538 current_inferior = saved_inferior;
542 /* This function should only be called if LWP got a SIGTRAP.
543 The SIGTRAP could mean several things.
545 On i386, where decr_pc_after_break is non-zero:
546 If we were single-stepping this process using PTRACE_SINGLESTEP,
547 we will get only the one SIGTRAP (even if the instruction we
548 stepped over was a breakpoint). The value of $eip will be the
550 If we continue the process using PTRACE_CONT, we will get a
551 SIGTRAP when we hit a breakpoint. The value of $eip will be
552 the instruction after the breakpoint (i.e. needs to be
553 decremented). If we report the SIGTRAP to GDB, we must also
554 report the undecremented PC. If we cancel the SIGTRAP, we
555 must resume at the decremented PC.
557 (Presumably, not yet tested) On a non-decr_pc_after_break machine
558 with hardware or kernel single-step:
559 If we single-step over a breakpoint instruction, our PC will
560 point at the following instruction. If we continue and hit a
561 breakpoint instruction, our PC will point at the breakpoint
565 get_stop_pc (struct lwp_info *lwp)
569 if (the_low_target.get_pc == NULL)
572 stop_pc = get_pc (lwp);
574 if (WSTOPSIG (lwp->last_status) == SIGTRAP
576 && !lwp->stopped_by_watchpoint
577 && lwp->last_status >> 16 == 0)
578 stop_pc -= the_low_target.decr_pc_after_break;
581 fprintf (stderr, "stop pc is 0x%lx\n", (long) stop_pc);
587 add_lwp (ptid_t ptid)
589 struct lwp_info *lwp;
591 lwp = (struct lwp_info *) xmalloc (sizeof (*lwp));
592 memset (lwp, 0, sizeof (*lwp));
596 if (the_low_target.new_thread != NULL)
597 lwp->arch_private = the_low_target.new_thread ();
599 add_inferior_to_list (&all_lwps, &lwp->head);
604 /* Start an inferior process and returns its pid.
605 ALLARGS is a vector of program-name and args. */
608 linux_create_inferior (char *program, char **allargs)
610 #ifdef HAVE_PERSONALITY
611 int personality_orig = 0, personality_set = 0;
613 struct lwp_info *new_lwp;
617 #ifdef HAVE_PERSONALITY
618 if (disable_randomization)
621 personality_orig = personality (0xffffffff);
622 if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE))
625 personality (personality_orig | ADDR_NO_RANDOMIZE);
627 if (errno != 0 || (personality_set
628 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE)))
629 warning ("Error disabling address space randomization: %s",
634 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
640 perror_with_name ("fork");
644 ptrace (PTRACE_TRACEME, 0, 0, 0);
646 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
647 signal (__SIGRTMIN + 1, SIG_DFL);
652 /* If gdbserver is connected to gdb via stdio, redirect the inferior's
653 stdout to stderr so that inferior i/o doesn't corrupt the connection.
654 Also, redirect stdin to /dev/null. */
655 if (remote_connection_is_stdio ())
658 open ("/dev/null", O_RDONLY);
660 if (write (2, "stdin/stdout redirected\n",
661 sizeof ("stdin/stdout redirected\n") - 1) < 0)
662 /* Errors ignored. */;
665 execv (program, allargs);
667 execvp (program, allargs);
669 fprintf (stderr, "Cannot exec %s: %s.\n", program,
675 #ifdef HAVE_PERSONALITY
679 personality (personality_orig);
681 warning ("Error restoring address space randomization: %s",
686 linux_add_process (pid, 0);
688 ptid = ptid_build (pid, pid, 0);
689 new_lwp = add_lwp (ptid);
690 add_thread (ptid, new_lwp);
691 new_lwp->must_set_ptrace_flags = 1;
696 /* Attach to an inferior process. */
699 linux_attach_lwp_1 (unsigned long lwpid, int initial)
702 struct lwp_info *new_lwp;
704 if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) != 0)
706 struct buffer buffer;
710 /* If we fail to attach to an LWP, just warn. */
711 fprintf (stderr, "Cannot attach to lwp %ld: %s (%d)\n", lwpid,
712 strerror (errno), errno);
717 /* If we fail to attach to a process, report an error. */
718 buffer_init (&buffer);
719 linux_ptrace_attach_warnings (lwpid, &buffer);
720 buffer_grow_str0 (&buffer, "");
721 error ("%sCannot attach to lwp %ld: %s (%d)", buffer_finish (&buffer),
722 lwpid, strerror (errno), errno);
726 /* If lwp is the tgid, we handle adding existing threads later.
727 Otherwise we just add lwp without bothering about any other
729 ptid = ptid_build (lwpid, lwpid, 0);
732 /* Note that extracting the pid from the current inferior is
733 safe, since we're always called in the context of the same
734 process as this new thread. */
735 int pid = pid_of (get_thread_lwp (current_inferior));
736 ptid = ptid_build (pid, lwpid, 0);
739 new_lwp = (struct lwp_info *) add_lwp (ptid);
740 add_thread (ptid, new_lwp);
742 /* We need to wait for SIGSTOP before being able to make the next
743 ptrace call on this LWP. */
744 new_lwp->must_set_ptrace_flags = 1;
746 if (linux_proc_pid_is_stopped (lwpid))
750 "Attached to a stopped process\n");
752 /* The process is definitely stopped. It is in a job control
753 stop, unless the kernel predates the TASK_STOPPED /
754 TASK_TRACED distinction, in which case it might be in a
755 ptrace stop. Make sure it is in a ptrace stop; from there we
756 can kill it, signal it, et cetera.
758 First make sure there is a pending SIGSTOP. Since we are
759 already attached, the process can not transition from stopped
760 to running without a PTRACE_CONT; so we know this signal will
761 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
762 probably already in the queue (unless this kernel is old
763 enough to use TASK_STOPPED for ptrace stops); but since
764 SIGSTOP is not an RT signal, it can only be queued once. */
765 kill_lwp (lwpid, SIGSTOP);
767 /* Finally, resume the stopped process. This will deliver the
768 SIGSTOP (or a higher priority signal, just like normal
769 PTRACE_ATTACH), which we'll catch later on. */
770 ptrace (PTRACE_CONT, lwpid, 0, 0);
773 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
776 There are several cases to consider here:
778 1) gdbserver has already attached to the process and is being notified
779 of a new thread that is being created.
780 In this case we should ignore that SIGSTOP and resume the
781 process. This is handled below by setting stop_expected = 1,
782 and the fact that add_thread sets last_resume_kind ==
785 2) This is the first thread (the process thread), and we're attaching
786 to it via attach_inferior.
787 In this case we want the process thread to stop.
788 This is handled by having linux_attach set last_resume_kind ==
789 resume_stop after we return.
791 If the pid we are attaching to is also the tgid, we attach to and
792 stop all the existing threads. Otherwise, we attach to pid and
793 ignore any other threads in the same group as this pid.
795 3) GDB is connecting to gdbserver and is requesting an enumeration of all
797 In this case we want the thread to stop.
798 FIXME: This case is currently not properly handled.
799 We should wait for the SIGSTOP but don't. Things work apparently
800 because enough time passes between when we ptrace (ATTACH) and when
801 gdb makes the next ptrace call on the thread.
803 On the other hand, if we are currently trying to stop all threads, we
804 should treat the new thread as if we had sent it a SIGSTOP. This works
805 because we are guaranteed that the add_lwp call above added us to the
806 end of the list, and so the new thread has not yet reached
807 wait_for_sigstop (but will). */
808 new_lwp->stop_expected = 1;
812 linux_attach_lwp (unsigned long lwpid)
814 linux_attach_lwp_1 (lwpid, 0);
817 /* Attach to PID. If PID is the tgid, attach to it and all
821 linux_attach (unsigned long pid)
823 /* Attach to PID. We will check for other threads
825 linux_attach_lwp_1 (pid, 1);
826 linux_add_process (pid, 1);
830 struct thread_info *thread;
832 /* Don't ignore the initial SIGSTOP if we just attached to this
833 process. It will be collected by wait shortly. */
834 thread = find_thread_ptid (ptid_build (pid, pid, 0));
835 thread->last_resume_kind = resume_stop;
838 if (linux_proc_get_tgid (pid) == pid)
843 sprintf (pathname, "/proc/%ld/task", pid);
845 dir = opendir (pathname);
849 fprintf (stderr, "Could not open /proc/%ld/task.\n", pid);
854 /* At this point we attached to the tgid. Scan the task for
857 int new_threads_found;
861 while (iterations < 2)
863 new_threads_found = 0;
864 /* Add all the other threads. While we go through the
865 threads, new threads may be spawned. Cycle through
866 the list of threads until we have done two iterations without
867 finding new threads. */
868 while ((dp = readdir (dir)) != NULL)
871 lwp = strtoul (dp->d_name, NULL, 10);
873 /* Is this a new thread? */
875 && find_thread_ptid (ptid_build (pid, lwp, 0)) == NULL)
877 linux_attach_lwp_1 (lwp, 0);
882 Found and attached to new lwp %ld\n", lwp);
886 if (!new_threads_found)
907 second_thread_of_pid_p (struct inferior_list_entry *entry, void *args)
909 struct counter *counter = args;
911 if (ptid_get_pid (entry->id) == counter->pid)
913 if (++counter->count > 1)
921 last_thread_of_process_p (struct thread_info *thread)
923 ptid_t ptid = ((struct inferior_list_entry *)thread)->id;
924 int pid = ptid_get_pid (ptid);
925 struct counter counter = { pid , 0 };
927 return (find_inferior (&all_threads,
928 second_thread_of_pid_p, &counter) == NULL);
934 linux_kill_one_lwp (struct lwp_info *lwp)
936 int pid = lwpid_of (lwp);
938 /* PTRACE_KILL is unreliable. After stepping into a signal handler,
939 there is no signal context, and ptrace(PTRACE_KILL) (or
940 ptrace(PTRACE_CONT, SIGKILL), pretty much the same) acts like
941 ptrace(CONT, pid, 0,0) and just resumes the tracee. A better
942 alternative is to kill with SIGKILL. We only need one SIGKILL
943 per process, not one for each thread. But since we still support
944 linuxthreads, and we also support debugging programs using raw
945 clone without CLONE_THREAD, we send one for each thread. For
946 years, we used PTRACE_KILL only, so we're being a bit paranoid
947 about some old kernels where PTRACE_KILL might work better
948 (dubious if there are any such, but that's why it's paranoia), so
949 we try SIGKILL first, PTRACE_KILL second, and so we're fine
956 "LKL: kill (SIGKILL) %s, 0, 0 (%s)\n",
957 target_pid_to_str (ptid_of (lwp)),
958 errno ? strerror (errno) : "OK");
961 ptrace (PTRACE_KILL, pid, 0, 0);
964 "LKL: PTRACE_KILL %s, 0, 0 (%s)\n",
965 target_pid_to_str (ptid_of (lwp)),
966 errno ? strerror (errno) : "OK");
969 /* Callback for `find_inferior'. Kills an lwp of a given process,
970 except the leader. */
973 kill_one_lwp_callback (struct inferior_list_entry *entry, void *args)
975 struct thread_info *thread = (struct thread_info *) entry;
976 struct lwp_info *lwp = get_thread_lwp (thread);
978 int pid = * (int *) args;
980 if (ptid_get_pid (entry->id) != pid)
983 /* We avoid killing the first thread here, because of a Linux kernel (at
984 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
985 the children get a chance to be reaped, it will remain a zombie
988 if (lwpid_of (lwp) == pid)
991 fprintf (stderr, "lkop: is last of process %s\n",
992 target_pid_to_str (entry->id));
998 linux_kill_one_lwp (lwp);
1000 /* Make sure it died. The loop is most likely unnecessary. */
1001 pid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
1002 } while (pid > 0 && WIFSTOPPED (wstat));
1008 linux_kill (int pid)
1010 struct process_info *process;
1011 struct lwp_info *lwp;
1015 process = find_process_pid (pid);
1016 if (process == NULL)
1019 /* If we're killing a running inferior, make sure it is stopped
1020 first, as PTRACE_KILL will not work otherwise. */
1021 stop_all_lwps (0, NULL);
1023 find_inferior (&all_threads, kill_one_lwp_callback , &pid);
1025 /* See the comment in linux_kill_one_lwp. We did not kill the first
1026 thread in the list, so do so now. */
1027 lwp = find_lwp_pid (pid_to_ptid (pid));
1032 fprintf (stderr, "lk_1: cannot find lwp %ld, for pid: %d\n",
1033 lwpid_of (lwp), pid);
1038 fprintf (stderr, "lk_1: killing lwp %ld, for pid: %d\n",
1039 lwpid_of (lwp), pid);
1043 linux_kill_one_lwp (lwp);
1045 /* Make sure it died. The loop is most likely unnecessary. */
1046 lwpid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
1047 } while (lwpid > 0 && WIFSTOPPED (wstat));
1050 the_target->mourn (process);
1052 /* Since we presently can only stop all lwps of all processes, we
1053 need to unstop lwps of other processes. */
1054 unstop_all_lwps (0, NULL);
1058 /* Get pending signal of THREAD, for detaching purposes. This is the
1059 signal the thread last stopped for, which we need to deliver to the
1060 thread when detaching, otherwise, it'd be suppressed/lost. */
1063 get_detach_signal (struct thread_info *thread)
1065 enum gdb_signal signo = GDB_SIGNAL_0;
1067 struct lwp_info *lp = get_thread_lwp (thread);
1069 if (lp->status_pending_p)
1070 status = lp->status_pending;
1073 /* If the thread had been suspended by gdbserver, and it stopped
1074 cleanly, then it'll have stopped with SIGSTOP. But we don't
1075 want to deliver that SIGSTOP. */
1076 if (thread->last_status.kind != TARGET_WAITKIND_STOPPED
1077 || thread->last_status.value.sig == GDB_SIGNAL_0)
1080 /* Otherwise, we may need to deliver the signal we
1082 status = lp->last_status;
1085 if (!WIFSTOPPED (status))
1089 "GPS: lwp %s hasn't stopped: no pending signal\n",
1090 target_pid_to_str (ptid_of (lp)));
1094 /* Extended wait statuses aren't real SIGTRAPs. */
1095 if (WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
1099 "GPS: lwp %s had stopped with extended "
1100 "status: no pending signal\n",
1101 target_pid_to_str (ptid_of (lp)));
1105 signo = gdb_signal_from_host (WSTOPSIG (status));
1107 if (program_signals_p && !program_signals[signo])
1111 "GPS: lwp %s had signal %s, but it is in nopass state\n",
1112 target_pid_to_str (ptid_of (lp)),
1113 gdb_signal_to_string (signo));
1116 else if (!program_signals_p
1117 /* If we have no way to know which signals GDB does not
1118 want to have passed to the program, assume
1119 SIGTRAP/SIGINT, which is GDB's default. */
1120 && (signo == GDB_SIGNAL_TRAP || signo == GDB_SIGNAL_INT))
1124 "GPS: lwp %s had signal %s, "
1125 "but we don't know if we should pass it. Default to not.\n",
1126 target_pid_to_str (ptid_of (lp)),
1127 gdb_signal_to_string (signo));
1134 "GPS: lwp %s has pending signal %s: delivering it.\n",
1135 target_pid_to_str (ptid_of (lp)),
1136 gdb_signal_to_string (signo));
1138 return WSTOPSIG (status);
1143 linux_detach_one_lwp (struct inferior_list_entry *entry, void *args)
1145 struct thread_info *thread = (struct thread_info *) entry;
1146 struct lwp_info *lwp = get_thread_lwp (thread);
1147 int pid = * (int *) args;
1150 if (ptid_get_pid (entry->id) != pid)
1153 /* If there is a pending SIGSTOP, get rid of it. */
1154 if (lwp->stop_expected)
1158 "Sending SIGCONT to %s\n",
1159 target_pid_to_str (ptid_of (lwp)));
1161 kill_lwp (lwpid_of (lwp), SIGCONT);
1162 lwp->stop_expected = 0;
1165 /* Flush any pending changes to the process's registers. */
1166 regcache_invalidate_one ((struct inferior_list_entry *)
1167 get_lwp_thread (lwp));
1169 /* Pass on any pending signal for this thread. */
1170 sig = get_detach_signal (thread);
1172 /* Finally, let it resume. */
1173 if (the_low_target.prepare_to_resume != NULL)
1174 the_low_target.prepare_to_resume (lwp);
1175 if (ptrace (PTRACE_DETACH, lwpid_of (lwp), 0,
1176 (PTRACE_ARG4_TYPE) (long) sig) < 0)
1177 error (_("Can't detach %s: %s"),
1178 target_pid_to_str (ptid_of (lwp)),
1186 linux_detach (int pid)
1188 struct process_info *process;
1190 process = find_process_pid (pid);
1191 if (process == NULL)
1194 /* Stop all threads before detaching. First, ptrace requires that
1195 the thread is stopped to sucessfully detach. Second, thread_db
1196 may need to uninstall thread event breakpoints from memory, which
1197 only works with a stopped process anyway. */
1198 stop_all_lwps (0, NULL);
1200 #ifdef USE_THREAD_DB
1201 thread_db_detach (process);
1204 /* Stabilize threads (move out of jump pads). */
1205 stabilize_threads ();
1207 find_inferior (&all_threads, linux_detach_one_lwp, &pid);
1209 the_target->mourn (process);
1211 /* Since we presently can only stop all lwps of all processes, we
1212 need to unstop lwps of other processes. */
1213 unstop_all_lwps (0, NULL);
1217 /* Remove all LWPs that belong to process PROC from the lwp list. */
1220 delete_lwp_callback (struct inferior_list_entry *entry, void *proc)
1222 struct lwp_info *lwp = (struct lwp_info *) entry;
1223 struct process_info *process = proc;
1225 if (pid_of (lwp) == pid_of (process))
1232 linux_mourn (struct process_info *process)
1234 struct process_info_private *priv;
1236 #ifdef USE_THREAD_DB
1237 thread_db_mourn (process);
1240 find_inferior (&all_lwps, delete_lwp_callback, process);
1242 /* Freeing all private data. */
1243 priv = process->private;
1244 free (priv->arch_private);
1246 process->private = NULL;
1248 remove_process (process);
1252 linux_join (int pid)
1257 ret = my_waitpid (pid, &status, 0);
1258 if (WIFEXITED (status) || WIFSIGNALED (status))
1260 } while (ret != -1 || errno != ECHILD);
1263 /* Return nonzero if the given thread is still alive. */
1265 linux_thread_alive (ptid_t ptid)
1267 struct lwp_info *lwp = find_lwp_pid (ptid);
1269 /* We assume we always know if a thread exits. If a whole process
1270 exited but we still haven't been able to report it to GDB, we'll
1271 hold on to the last lwp of the dead process. */
1278 /* Return 1 if this lwp has an interesting status pending. */
1280 status_pending_p_callback (struct inferior_list_entry *entry, void *arg)
1282 struct lwp_info *lwp = (struct lwp_info *) entry;
1283 ptid_t ptid = * (ptid_t *) arg;
1284 struct thread_info *thread;
1286 /* Check if we're only interested in events from a specific process
1288 if (!ptid_equal (minus_one_ptid, ptid)
1289 && ptid_get_pid (ptid) != ptid_get_pid (lwp->head.id))
1292 thread = get_lwp_thread (lwp);
1294 /* If we got a `vCont;t', but we haven't reported a stop yet, do
1295 report any status pending the LWP may have. */
1296 if (thread->last_resume_kind == resume_stop
1297 && thread->last_status.kind != TARGET_WAITKIND_IGNORE)
1300 return lwp->status_pending_p;
1304 same_lwp (struct inferior_list_entry *entry, void *data)
1306 ptid_t ptid = *(ptid_t *) data;
1309 if (ptid_get_lwp (ptid) != 0)
1310 lwp = ptid_get_lwp (ptid);
1312 lwp = ptid_get_pid (ptid);
1314 if (ptid_get_lwp (entry->id) == lwp)
1321 find_lwp_pid (ptid_t ptid)
1323 return (struct lwp_info*) find_inferior (&all_lwps, same_lwp, &ptid);
1326 static struct lwp_info *
1327 linux_wait_for_lwp (ptid_t ptid, int *wstatp, int options)
1330 int to_wait_for = -1;
1331 struct lwp_info *child = NULL;
1334 fprintf (stderr, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid));
1336 if (ptid_equal (ptid, minus_one_ptid))
1337 to_wait_for = -1; /* any child */
1339 to_wait_for = ptid_get_lwp (ptid); /* this lwp only */
1345 ret = my_waitpid (to_wait_for, wstatp, options);
1346 if (ret == 0 || (ret == -1 && errno == ECHILD && (options & WNOHANG)))
1349 perror_with_name ("waitpid");
1352 && (!WIFSTOPPED (*wstatp)
1353 || (WSTOPSIG (*wstatp) != 32
1354 && WSTOPSIG (*wstatp) != 33)))
1355 fprintf (stderr, "Got an event from %d (%x)\n", ret, *wstatp);
1357 child = find_lwp_pid (pid_to_ptid (ret));
1359 /* If we didn't find a process, one of two things presumably happened:
1360 - A process we started and then detached from has exited. Ignore it.
1361 - A process we are controlling has forked and the new child's stop
1362 was reported to us by the kernel. Save its PID. */
1363 if (child == NULL && WIFSTOPPED (*wstatp))
1365 add_to_pid_list (&stopped_pids, ret, *wstatp);
1368 else if (child == NULL)
1373 child->last_status = *wstatp;
1375 /* Architecture-specific setup after inferior is running.
1376 This needs to happen after we have attached to the inferior
1377 and it is stopped for the first time, but before we access
1378 any inferior registers. */
1381 the_low_target.arch_setup ();
1382 #ifdef HAVE_LINUX_REGSETS
1383 memset (disabled_regsets, 0, num_regsets);
1388 /* Fetch the possibly triggered data watchpoint info and store it in
1391 On some archs, like x86, that use debug registers to set
1392 watchpoints, it's possible that the way to know which watched
1393 address trapped, is to check the register that is used to select
1394 which address to watch. Problem is, between setting the
1395 watchpoint and reading back which data address trapped, the user
1396 may change the set of watchpoints, and, as a consequence, GDB
1397 changes the debug registers in the inferior. To avoid reading
1398 back a stale stopped-data-address when that happens, we cache in
1399 LP the fact that a watchpoint trapped, and the corresponding data
1400 address, as soon as we see CHILD stop with a SIGTRAP. If GDB
1401 changes the debug registers meanwhile, we have the cached data we
1404 if (WIFSTOPPED (*wstatp) && WSTOPSIG (*wstatp) == SIGTRAP)
1406 if (the_low_target.stopped_by_watchpoint == NULL)
1408 child->stopped_by_watchpoint = 0;
1412 struct thread_info *saved_inferior;
1414 saved_inferior = current_inferior;
1415 current_inferior = get_lwp_thread (child);
1417 child->stopped_by_watchpoint
1418 = the_low_target.stopped_by_watchpoint ();
1420 if (child->stopped_by_watchpoint)
1422 if (the_low_target.stopped_data_address != NULL)
1423 child->stopped_data_address
1424 = the_low_target.stopped_data_address ();
1426 child->stopped_data_address = 0;
1429 current_inferior = saved_inferior;
1433 /* Store the STOP_PC, with adjustment applied. This depends on the
1434 architecture being defined already (so that CHILD has a valid
1435 regcache), and on LAST_STATUS being set (to check for SIGTRAP or
1437 if (WIFSTOPPED (*wstatp))
1438 child->stop_pc = get_stop_pc (child);
1441 && WIFSTOPPED (*wstatp)
1442 && the_low_target.get_pc != NULL)
1444 struct thread_info *saved_inferior = current_inferior;
1445 struct regcache *regcache;
1448 current_inferior = get_lwp_thread (child);
1449 regcache = get_thread_regcache (current_inferior, 1);
1450 pc = (*the_low_target.get_pc) (regcache);
1451 fprintf (stderr, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc);
1452 current_inferior = saved_inferior;
1458 /* This function should only be called if the LWP got a SIGTRAP.
1460 Handle any tracepoint steps or hits. Return true if a tracepoint
1461 event was handled, 0 otherwise. */
1464 handle_tracepoints (struct lwp_info *lwp)
1466 struct thread_info *tinfo = get_lwp_thread (lwp);
1467 int tpoint_related_event = 0;
1469 /* If this tracepoint hit causes a tracing stop, we'll immediately
1470 uninsert tracepoints. To do this, we temporarily pause all
1471 threads, unpatch away, and then unpause threads. We need to make
1472 sure the unpausing doesn't resume LWP too. */
1475 /* And we need to be sure that any all-threads-stopping doesn't try
1476 to move threads out of the jump pads, as it could deadlock the
1477 inferior (LWP could be in the jump pad, maybe even holding the
1480 /* Do any necessary step collect actions. */
1481 tpoint_related_event |= tracepoint_finished_step (tinfo, lwp->stop_pc);
1483 tpoint_related_event |= handle_tracepoint_bkpts (tinfo, lwp->stop_pc);
1485 /* See if we just hit a tracepoint and do its main collect
1487 tpoint_related_event |= tracepoint_was_hit (tinfo, lwp->stop_pc);
1491 gdb_assert (lwp->suspended == 0);
1492 gdb_assert (!stabilizing_threads || lwp->collecting_fast_tracepoint);
1494 if (tpoint_related_event)
1497 fprintf (stderr, "got a tracepoint event\n");
1504 /* Convenience wrapper. Returns true if LWP is presently collecting a
1508 linux_fast_tracepoint_collecting (struct lwp_info *lwp,
1509 struct fast_tpoint_collect_status *status)
1511 CORE_ADDR thread_area;
1513 if (the_low_target.get_thread_area == NULL)
1516 /* Get the thread area address. This is used to recognize which
1517 thread is which when tracing with the in-process agent library.
1518 We don't read anything from the address, and treat it as opaque;
1519 it's the address itself that we assume is unique per-thread. */
1520 if ((*the_low_target.get_thread_area) (lwpid_of (lwp), &thread_area) == -1)
1523 return fast_tracepoint_collecting (thread_area, lwp->stop_pc, status);
1526 /* The reason we resume in the caller, is because we want to be able
1527 to pass lwp->status_pending as WSTAT, and we need to clear
1528 status_pending_p before resuming, otherwise, linux_resume_one_lwp
1529 refuses to resume. */
1532 maybe_move_out_of_jump_pad (struct lwp_info *lwp, int *wstat)
1534 struct thread_info *saved_inferior;
1536 saved_inferior = current_inferior;
1537 current_inferior = get_lwp_thread (lwp);
1540 || (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) != SIGTRAP))
1541 && supports_fast_tracepoints ()
1542 && agent_loaded_p ())
1544 struct fast_tpoint_collect_status status;
1549 Checking whether LWP %ld needs to move out of the jump pad.\n",
1552 r = linux_fast_tracepoint_collecting (lwp, &status);
1555 || (WSTOPSIG (*wstat) != SIGILL
1556 && WSTOPSIG (*wstat) != SIGFPE
1557 && WSTOPSIG (*wstat) != SIGSEGV
1558 && WSTOPSIG (*wstat) != SIGBUS))
1560 lwp->collecting_fast_tracepoint = r;
1564 if (r == 1 && lwp->exit_jump_pad_bkpt == NULL)
1566 /* Haven't executed the original instruction yet.
1567 Set breakpoint there, and wait till it's hit,
1568 then single-step until exiting the jump pad. */
1569 lwp->exit_jump_pad_bkpt
1570 = set_breakpoint_at (status.adjusted_insn_addr, NULL);
1575 Checking whether LWP %ld needs to move out of the jump pad...it does\n",
1577 current_inferior = saved_inferior;
1584 /* If we get a synchronous signal while collecting, *and*
1585 while executing the (relocated) original instruction,
1586 reset the PC to point at the tpoint address, before
1587 reporting to GDB. Otherwise, it's an IPA lib bug: just
1588 report the signal to GDB, and pray for the best. */
1590 lwp->collecting_fast_tracepoint = 0;
1593 && (status.adjusted_insn_addr <= lwp->stop_pc
1594 && lwp->stop_pc < status.adjusted_insn_addr_end))
1597 struct regcache *regcache;
1599 /* The si_addr on a few signals references the address
1600 of the faulting instruction. Adjust that as
1602 if ((WSTOPSIG (*wstat) == SIGILL
1603 || WSTOPSIG (*wstat) == SIGFPE
1604 || WSTOPSIG (*wstat) == SIGBUS
1605 || WSTOPSIG (*wstat) == SIGSEGV)
1606 && ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &info) == 0
1607 /* Final check just to make sure we don't clobber
1608 the siginfo of non-kernel-sent signals. */
1609 && (uintptr_t) info.si_addr == lwp->stop_pc)
1611 info.si_addr = (void *) (uintptr_t) status.tpoint_addr;
1612 ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &info);
1615 regcache = get_thread_regcache (get_lwp_thread (lwp), 1);
1616 (*the_low_target.set_pc) (regcache, status.tpoint_addr);
1617 lwp->stop_pc = status.tpoint_addr;
1619 /* Cancel any fast tracepoint lock this thread was
1621 force_unlock_trace_buffer ();
1624 if (lwp->exit_jump_pad_bkpt != NULL)
1628 "Cancelling fast exit-jump-pad: removing bkpt. "
1629 "stopping all threads momentarily.\n");
1631 stop_all_lwps (1, lwp);
1632 cancel_breakpoints ();
1634 delete_breakpoint (lwp->exit_jump_pad_bkpt);
1635 lwp->exit_jump_pad_bkpt = NULL;
1637 unstop_all_lwps (1, lwp);
1639 gdb_assert (lwp->suspended >= 0);
1646 Checking whether LWP %ld needs to move out of the jump pad...no\n",
1649 current_inferior = saved_inferior;
1653 /* Enqueue one signal in the "signals to report later when out of the
1657 enqueue_one_deferred_signal (struct lwp_info *lwp, int *wstat)
1659 struct pending_signals *p_sig;
1663 Deferring signal %d for LWP %ld.\n", WSTOPSIG (*wstat), lwpid_of (lwp));
1667 struct pending_signals *sig;
1669 for (sig = lwp->pending_signals_to_report;
1673 " Already queued %d\n",
1676 fprintf (stderr, " (no more currently queued signals)\n");
1679 /* Don't enqueue non-RT signals if they are already in the deferred
1680 queue. (SIGSTOP being the easiest signal to see ending up here
1682 if (WSTOPSIG (*wstat) < __SIGRTMIN)
1684 struct pending_signals *sig;
1686 for (sig = lwp->pending_signals_to_report;
1690 if (sig->signal == WSTOPSIG (*wstat))
1694 "Not requeuing already queued non-RT signal %d"
1703 p_sig = xmalloc (sizeof (*p_sig));
1704 p_sig->prev = lwp->pending_signals_to_report;
1705 p_sig->signal = WSTOPSIG (*wstat);
1706 memset (&p_sig->info, 0, sizeof (siginfo_t));
1707 ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info);
1709 lwp->pending_signals_to_report = p_sig;
1712 /* Dequeue one signal from the "signals to report later when out of
1713 the jump pad" list. */
1716 dequeue_one_deferred_signal (struct lwp_info *lwp, int *wstat)
1718 if (lwp->pending_signals_to_report != NULL)
1720 struct pending_signals **p_sig;
1722 p_sig = &lwp->pending_signals_to_report;
1723 while ((*p_sig)->prev != NULL)
1724 p_sig = &(*p_sig)->prev;
1726 *wstat = W_STOPCODE ((*p_sig)->signal);
1727 if ((*p_sig)->info.si_signo != 0)
1728 ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &(*p_sig)->info);
1733 fprintf (stderr, "Reporting deferred signal %d for LWP %ld.\n",
1734 WSTOPSIG (*wstat), lwpid_of (lwp));
1738 struct pending_signals *sig;
1740 for (sig = lwp->pending_signals_to_report;
1744 " Still queued %d\n",
1747 fprintf (stderr, " (no more queued signals)\n");
1756 /* Arrange for a breakpoint to be hit again later. We don't keep the
1757 SIGTRAP status and don't forward the SIGTRAP signal to the LWP. We
1758 will handle the current event, eventually we will resume this LWP,
1759 and this breakpoint will trap again. */
1762 cancel_breakpoint (struct lwp_info *lwp)
1764 struct thread_info *saved_inferior;
1766 /* There's nothing to do if we don't support breakpoints. */
1767 if (!supports_breakpoints ())
1770 /* breakpoint_at reads from current inferior. */
1771 saved_inferior = current_inferior;
1772 current_inferior = get_lwp_thread (lwp);
1774 if ((*the_low_target.breakpoint_at) (lwp->stop_pc))
1778 "CB: Push back breakpoint for %s\n",
1779 target_pid_to_str (ptid_of (lwp)));
1781 /* Back up the PC if necessary. */
1782 if (the_low_target.decr_pc_after_break)
1784 struct regcache *regcache
1785 = get_thread_regcache (current_inferior, 1);
1786 (*the_low_target.set_pc) (regcache, lwp->stop_pc);
1789 current_inferior = saved_inferior;
1796 "CB: No breakpoint found at %s for [%s]\n",
1797 paddress (lwp->stop_pc),
1798 target_pid_to_str (ptid_of (lwp)));
1801 current_inferior = saved_inferior;
1805 /* When the event-loop is doing a step-over, this points at the thread
1807 ptid_t step_over_bkpt;
1809 /* Wait for an event from child PID. If PID is -1, wait for any
1810 child. Store the stop status through the status pointer WSTAT.
1811 OPTIONS is passed to the waitpid call. Return 0 if no child stop
1812 event was found and OPTIONS contains WNOHANG. Return the PID of
1813 the stopped child otherwise. */
1816 linux_wait_for_event (ptid_t ptid, int *wstat, int options)
1818 struct lwp_info *event_child, *requested_child;
1822 requested_child = NULL;
1824 /* Check for a lwp with a pending status. */
1826 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
1828 event_child = (struct lwp_info *)
1829 find_inferior (&all_lwps, status_pending_p_callback, &ptid);
1830 if (debug_threads && event_child)
1831 fprintf (stderr, "Got a pending child %ld\n", lwpid_of (event_child));
1835 requested_child = find_lwp_pid (ptid);
1837 if (stopping_threads == NOT_STOPPING_THREADS
1838 && requested_child->status_pending_p
1839 && requested_child->collecting_fast_tracepoint)
1841 enqueue_one_deferred_signal (requested_child,
1842 &requested_child->status_pending);
1843 requested_child->status_pending_p = 0;
1844 requested_child->status_pending = 0;
1845 linux_resume_one_lwp (requested_child, 0, 0, NULL);
1848 if (requested_child->suspended
1849 && requested_child->status_pending_p)
1850 fatal ("requesting an event out of a suspended child?");
1852 if (requested_child->status_pending_p)
1853 event_child = requested_child;
1856 if (event_child != NULL)
1859 fprintf (stderr, "Got an event from pending child %ld (%04x)\n",
1860 lwpid_of (event_child), event_child->status_pending);
1861 *wstat = event_child->status_pending;
1862 event_child->status_pending_p = 0;
1863 event_child->status_pending = 0;
1864 current_inferior = get_lwp_thread (event_child);
1865 return lwpid_of (event_child);
1868 if (ptid_is_pid (ptid))
1870 /* A request to wait for a specific tgid. This is not possible
1871 with waitpid, so instead, we wait for any child, and leave
1872 children we're not interested in right now with a pending
1873 status to report later. */
1874 wait_ptid = minus_one_ptid;
1879 /* We only enter this loop if no process has a pending wait status. Thus
1880 any action taken in response to a wait status inside this loop is
1881 responding as soon as we detect the status, not after any pending
1885 event_child = linux_wait_for_lwp (wait_ptid, wstat, options);
1887 if ((options & WNOHANG) && event_child == NULL)
1890 fprintf (stderr, "WNOHANG set, no event found\n");
1894 if (event_child == NULL)
1895 error ("event from unknown child");
1897 if (ptid_is_pid (ptid)
1898 && ptid_get_pid (ptid) != ptid_get_pid (ptid_of (event_child)))
1900 if (! WIFSTOPPED (*wstat))
1901 mark_lwp_dead (event_child, *wstat);
1904 event_child->status_pending_p = 1;
1905 event_child->status_pending = *wstat;
1910 current_inferior = get_lwp_thread (event_child);
1912 /* Check for thread exit. */
1913 if (! WIFSTOPPED (*wstat))
1916 fprintf (stderr, "LWP %ld exiting\n", lwpid_of (event_child));
1918 /* If the last thread is exiting, just return. */
1919 if (last_thread_of_process_p (current_inferior))
1922 fprintf (stderr, "LWP %ld is last lwp of process\n",
1923 lwpid_of (event_child));
1924 return lwpid_of (event_child);
1929 current_inferior = (struct thread_info *) all_threads.head;
1931 fprintf (stderr, "Current inferior is now %ld\n",
1932 lwpid_of (get_thread_lwp (current_inferior)));
1936 current_inferior = NULL;
1938 fprintf (stderr, "Current inferior is now <NULL>\n");
1941 /* If we were waiting for this particular child to do something...
1942 well, it did something. */
1943 if (requested_child != NULL)
1945 int lwpid = lwpid_of (event_child);
1947 /* Cancel the step-over operation --- the thread that
1948 started it is gone. */
1949 if (finish_step_over (event_child))
1950 unstop_all_lwps (1, event_child);
1951 delete_lwp (event_child);
1955 delete_lwp (event_child);
1957 /* Wait for a more interesting event. */
1961 if (event_child->must_set_ptrace_flags)
1963 linux_enable_event_reporting (lwpid_of (event_child));
1964 event_child->must_set_ptrace_flags = 0;
1967 if (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) == SIGTRAP
1968 && *wstat >> 16 != 0)
1970 handle_extended_wait (event_child, *wstat);
1974 if (WIFSTOPPED (*wstat)
1975 && WSTOPSIG (*wstat) == SIGSTOP
1976 && event_child->stop_expected)
1981 fprintf (stderr, "Expected stop.\n");
1982 event_child->stop_expected = 0;
1984 should_stop = (current_inferior->last_resume_kind == resume_stop
1985 || stopping_threads != NOT_STOPPING_THREADS);
1989 linux_resume_one_lwp (event_child,
1990 event_child->stepping, 0, NULL);
1995 return lwpid_of (event_child);
2002 /* Count the LWP's that have had events. */
2005 count_events_callback (struct inferior_list_entry *entry, void *data)
2007 struct lwp_info *lp = (struct lwp_info *) entry;
2008 struct thread_info *thread = get_lwp_thread (lp);
2011 gdb_assert (count != NULL);
2013 /* Count only resumed LWPs that have a SIGTRAP event pending that
2014 should be reported to GDB. */
2015 if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
2016 && thread->last_resume_kind != resume_stop
2017 && lp->status_pending_p
2018 && WIFSTOPPED (lp->status_pending)
2019 && WSTOPSIG (lp->status_pending) == SIGTRAP
2020 && !breakpoint_inserted_here (lp->stop_pc))
2026 /* Select the LWP (if any) that is currently being single-stepped. */
2029 select_singlestep_lwp_callback (struct inferior_list_entry *entry, void *data)
2031 struct lwp_info *lp = (struct lwp_info *) entry;
2032 struct thread_info *thread = get_lwp_thread (lp);
2034 if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
2035 && thread->last_resume_kind == resume_step
2036 && lp->status_pending_p)
2042 /* Select the Nth LWP that has had a SIGTRAP event that should be
2046 select_event_lwp_callback (struct inferior_list_entry *entry, void *data)
2048 struct lwp_info *lp = (struct lwp_info *) entry;
2049 struct thread_info *thread = get_lwp_thread (lp);
2050 int *selector = data;
2052 gdb_assert (selector != NULL);
2054 /* Select only resumed LWPs that have a SIGTRAP event pending. */
2055 if (thread->last_resume_kind != resume_stop
2056 && thread->last_status.kind == TARGET_WAITKIND_IGNORE
2057 && lp->status_pending_p
2058 && WIFSTOPPED (lp->status_pending)
2059 && WSTOPSIG (lp->status_pending) == SIGTRAP
2060 && !breakpoint_inserted_here (lp->stop_pc))
2061 if ((*selector)-- == 0)
2068 cancel_breakpoints_callback (struct inferior_list_entry *entry, void *data)
2070 struct lwp_info *lp = (struct lwp_info *) entry;
2071 struct thread_info *thread = get_lwp_thread (lp);
2072 struct lwp_info *event_lp = data;
2074 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
2078 /* If a LWP other than the LWP that we're reporting an event for has
2079 hit a GDB breakpoint (as opposed to some random trap signal),
2080 then just arrange for it to hit it again later. We don't keep
2081 the SIGTRAP status and don't forward the SIGTRAP signal to the
2082 LWP. We will handle the current event, eventually we will resume
2083 all LWPs, and this one will get its breakpoint trap again.
2085 If we do not do this, then we run the risk that the user will
2086 delete or disable the breakpoint, but the LWP will have already
2089 if (thread->last_resume_kind != resume_stop
2090 && thread->last_status.kind == TARGET_WAITKIND_IGNORE
2091 && lp->status_pending_p
2092 && WIFSTOPPED (lp->status_pending)
2093 && WSTOPSIG (lp->status_pending) == SIGTRAP
2095 && !lp->stopped_by_watchpoint
2096 && cancel_breakpoint (lp))
2097 /* Throw away the SIGTRAP. */
2098 lp->status_pending_p = 0;
2104 linux_cancel_breakpoints (void)
2106 find_inferior (&all_lwps, cancel_breakpoints_callback, NULL);
2109 /* Select one LWP out of those that have events pending. */
2112 select_event_lwp (struct lwp_info **orig_lp)
2115 int random_selector;
2116 struct lwp_info *event_lp;
2118 /* Give preference to any LWP that is being single-stepped. */
2120 = (struct lwp_info *) find_inferior (&all_lwps,
2121 select_singlestep_lwp_callback, NULL);
2122 if (event_lp != NULL)
2126 "SEL: Select single-step %s\n",
2127 target_pid_to_str (ptid_of (event_lp)));
2131 /* No single-stepping LWP. Select one at random, out of those
2132 which have had SIGTRAP events. */
2134 /* First see how many SIGTRAP events we have. */
2135 find_inferior (&all_lwps, count_events_callback, &num_events);
2137 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
2138 random_selector = (int)
2139 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
2141 if (debug_threads && num_events > 1)
2143 "SEL: Found %d SIGTRAP events, selecting #%d\n",
2144 num_events, random_selector);
2146 event_lp = (struct lwp_info *) find_inferior (&all_lwps,
2147 select_event_lwp_callback,
2151 if (event_lp != NULL)
2153 /* Switch the event LWP. */
2154 *orig_lp = event_lp;
2158 /* Decrement the suspend count of an LWP. */
2161 unsuspend_one_lwp (struct inferior_list_entry *entry, void *except)
2163 struct lwp_info *lwp = (struct lwp_info *) entry;
2165 /* Ignore EXCEPT. */
2171 gdb_assert (lwp->suspended >= 0);
2175 /* Decrement the suspend count of all LWPs, except EXCEPT, if non
2179 unsuspend_all_lwps (struct lwp_info *except)
2181 find_inferior (&all_lwps, unsuspend_one_lwp, except);
2184 static void move_out_of_jump_pad_callback (struct inferior_list_entry *entry);
2185 static int stuck_in_jump_pad_callback (struct inferior_list_entry *entry,
2187 static int lwp_running (struct inferior_list_entry *entry, void *data);
2188 static ptid_t linux_wait_1 (ptid_t ptid,
2189 struct target_waitstatus *ourstatus,
2190 int target_options);
2192 /* Stabilize threads (move out of jump pads).
2194 If a thread is midway collecting a fast tracepoint, we need to
2195 finish the collection and move it out of the jump pad before
2196 reporting the signal.
2198 This avoids recursion while collecting (when a signal arrives
2199 midway, and the signal handler itself collects), which would trash
2200 the trace buffer. In case the user set a breakpoint in a signal
2201 handler, this avoids the backtrace showing the jump pad, etc..
2202 Most importantly, there are certain things we can't do safely if
2203 threads are stopped in a jump pad (or in its callee's). For
2206 - starting a new trace run. A thread still collecting the
2207 previous run, could trash the trace buffer when resumed. The trace
2208 buffer control structures would have been reset but the thread had
2209 no way to tell. The thread could even midway memcpy'ing to the
2210 buffer, which would mean that when resumed, it would clobber the
2211 trace buffer that had been set for a new run.
2213 - we can't rewrite/reuse the jump pads for new tracepoints
2214 safely. Say you do tstart while a thread is stopped midway while
2215 collecting. When the thread is later resumed, it finishes the
2216 collection, and returns to the jump pad, to execute the original
2217 instruction that was under the tracepoint jump at the time the
2218 older run had been started. If the jump pad had been rewritten
2219 since for something else in the new run, the thread would now
2220 execute the wrong / random instructions. */
2223 linux_stabilize_threads (void)
2225 struct thread_info *save_inferior;
2226 struct lwp_info *lwp_stuck;
2229 = (struct lwp_info *) find_inferior (&all_lwps,
2230 stuck_in_jump_pad_callback, NULL);
2231 if (lwp_stuck != NULL)
2234 fprintf (stderr, "can't stabilize, LWP %ld is stuck in jump pad\n",
2235 lwpid_of (lwp_stuck));
2239 save_inferior = current_inferior;
2241 stabilizing_threads = 1;
2244 for_each_inferior (&all_lwps, move_out_of_jump_pad_callback);
2246 /* Loop until all are stopped out of the jump pads. */
2247 while (find_inferior (&all_lwps, lwp_running, NULL) != NULL)
2249 struct target_waitstatus ourstatus;
2250 struct lwp_info *lwp;
2253 /* Note that we go through the full wait even loop. While
2254 moving threads out of jump pad, we need to be able to step
2255 over internal breakpoints and such. */
2256 linux_wait_1 (minus_one_ptid, &ourstatus, 0);
2258 if (ourstatus.kind == TARGET_WAITKIND_STOPPED)
2260 lwp = get_thread_lwp (current_inferior);
2265 if (ourstatus.value.sig != GDB_SIGNAL_0
2266 || current_inferior->last_resume_kind == resume_stop)
2268 wstat = W_STOPCODE (gdb_signal_to_host (ourstatus.value.sig));
2269 enqueue_one_deferred_signal (lwp, &wstat);
2274 find_inferior (&all_lwps, unsuspend_one_lwp, NULL);
2276 stabilizing_threads = 0;
2278 current_inferior = save_inferior;
2283 = (struct lwp_info *) find_inferior (&all_lwps,
2284 stuck_in_jump_pad_callback, NULL);
2285 if (lwp_stuck != NULL)
2286 fprintf (stderr, "couldn't stabilize, LWP %ld got stuck in jump pad\n",
2287 lwpid_of (lwp_stuck));
2291 /* Wait for process, returns status. */
2294 linux_wait_1 (ptid_t ptid,
2295 struct target_waitstatus *ourstatus, int target_options)
2298 struct lwp_info *event_child;
2301 int step_over_finished;
2302 int bp_explains_trap;
2303 int maybe_internal_trap;
2307 /* Translate generic target options into linux options. */
2309 if (target_options & TARGET_WNOHANG)
2313 bp_explains_trap = 0;
2315 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2317 /* If we were only supposed to resume one thread, only wait for
2318 that thread - if it's still alive. If it died, however - which
2319 can happen if we're coming from the thread death case below -
2320 then we need to make sure we restart the other threads. We could
2321 pick a thread at random or restart all; restarting all is less
2324 && !ptid_equal (cont_thread, null_ptid)
2325 && !ptid_equal (cont_thread, minus_one_ptid))
2327 struct thread_info *thread;
2329 thread = (struct thread_info *) find_inferior_id (&all_threads,
2332 /* No stepping, no signal - unless one is pending already, of course. */
2335 struct thread_resume resume_info;
2336 resume_info.thread = minus_one_ptid;
2337 resume_info.kind = resume_continue;
2338 resume_info.sig = 0;
2339 linux_resume (&resume_info, 1);
2345 if (ptid_equal (step_over_bkpt, null_ptid))
2346 pid = linux_wait_for_event (ptid, &w, options);
2350 fprintf (stderr, "step_over_bkpt set [%s], doing a blocking wait\n",
2351 target_pid_to_str (step_over_bkpt));
2352 pid = linux_wait_for_event (step_over_bkpt, &w, options & ~WNOHANG);
2355 if (pid == 0) /* only if TARGET_WNOHANG */
2358 event_child = get_thread_lwp (current_inferior);
2360 /* If we are waiting for a particular child, and it exited,
2361 linux_wait_for_event will return its exit status. Similarly if
2362 the last child exited. If this is not the last child, however,
2363 do not report it as exited until there is a 'thread exited' response
2364 available in the remote protocol. Instead, just wait for another event.
2365 This should be safe, because if the thread crashed we will already
2366 have reported the termination signal to GDB; that should stop any
2367 in-progress stepping operations, etc.
2369 Report the exit status of the last thread to exit. This matches
2370 LinuxThreads' behavior. */
2372 if (last_thread_of_process_p (current_inferior))
2374 if (WIFEXITED (w) || WIFSIGNALED (w))
2378 ourstatus->kind = TARGET_WAITKIND_EXITED;
2379 ourstatus->value.integer = WEXITSTATUS (w);
2383 "\nChild exited with retcode = %x \n",
2388 ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
2389 ourstatus->value.sig = gdb_signal_from_host (WTERMSIG (w));
2393 "\nChild terminated with signal = %x \n",
2398 return ptid_of (event_child);
2403 if (!WIFSTOPPED (w))
2407 /* If this event was not handled before, and is not a SIGTRAP, we
2408 report it. SIGILL and SIGSEGV are also treated as traps in case
2409 a breakpoint is inserted at the current PC. If this target does
2410 not support internal breakpoints at all, we also report the
2411 SIGTRAP without further processing; it's of no concern to us. */
2413 = (supports_breakpoints ()
2414 && (WSTOPSIG (w) == SIGTRAP
2415 || ((WSTOPSIG (w) == SIGILL
2416 || WSTOPSIG (w) == SIGSEGV)
2417 && (*the_low_target.breakpoint_at) (event_child->stop_pc))));
2419 if (maybe_internal_trap)
2421 /* Handle anything that requires bookkeeping before deciding to
2422 report the event or continue waiting. */
2424 /* First check if we can explain the SIGTRAP with an internal
2425 breakpoint, or if we should possibly report the event to GDB.
2426 Do this before anything that may remove or insert a
2428 bp_explains_trap = breakpoint_inserted_here (event_child->stop_pc);
2430 /* We have a SIGTRAP, possibly a step-over dance has just
2431 finished. If so, tweak the state machine accordingly,
2432 reinsert breakpoints and delete any reinsert (software
2433 single-step) breakpoints. */
2434 step_over_finished = finish_step_over (event_child);
2436 /* Now invoke the callbacks of any internal breakpoints there. */
2437 check_breakpoints (event_child->stop_pc);
2439 /* Handle tracepoint data collecting. This may overflow the
2440 trace buffer, and cause a tracing stop, removing
2442 trace_event = handle_tracepoints (event_child);
2444 if (bp_explains_trap)
2446 /* If we stepped or ran into an internal breakpoint, we've
2447 already handled it. So next time we resume (from this
2448 PC), we should step over it. */
2450 fprintf (stderr, "Hit a gdbserver breakpoint.\n");
2452 if (breakpoint_here (event_child->stop_pc))
2453 event_child->need_step_over = 1;
2458 /* We have some other signal, possibly a step-over dance was in
2459 progress, and it should be cancelled too. */
2460 step_over_finished = finish_step_over (event_child);
2463 /* We have all the data we need. Either report the event to GDB, or
2464 resume threads and keep waiting for more. */
2466 /* If we're collecting a fast tracepoint, finish the collection and
2467 move out of the jump pad before delivering a signal. See
2468 linux_stabilize_threads. */
2471 && WSTOPSIG (w) != SIGTRAP
2472 && supports_fast_tracepoints ()
2473 && agent_loaded_p ())
2477 "Got signal %d for LWP %ld. Check if we need "
2478 "to defer or adjust it.\n",
2479 WSTOPSIG (w), lwpid_of (event_child));
2481 /* Allow debugging the jump pad itself. */
2482 if (current_inferior->last_resume_kind != resume_step
2483 && maybe_move_out_of_jump_pad (event_child, &w))
2485 enqueue_one_deferred_signal (event_child, &w);
2489 "Signal %d for LWP %ld deferred (in jump pad)\n",
2490 WSTOPSIG (w), lwpid_of (event_child));
2492 linux_resume_one_lwp (event_child, 0, 0, NULL);
2497 if (event_child->collecting_fast_tracepoint)
2501 LWP %ld was trying to move out of the jump pad (%d). \
2502 Check if we're already there.\n",
2503 lwpid_of (event_child),
2504 event_child->collecting_fast_tracepoint);
2508 event_child->collecting_fast_tracepoint
2509 = linux_fast_tracepoint_collecting (event_child, NULL);
2511 if (event_child->collecting_fast_tracepoint != 1)
2513 /* No longer need this breakpoint. */
2514 if (event_child->exit_jump_pad_bkpt != NULL)
2518 "No longer need exit-jump-pad bkpt; removing it."
2519 "stopping all threads momentarily.\n");
2521 /* Other running threads could hit this breakpoint.
2522 We don't handle moribund locations like GDB does,
2523 instead we always pause all threads when removing
2524 breakpoints, so that any step-over or
2525 decr_pc_after_break adjustment is always taken
2526 care of while the breakpoint is still
2528 stop_all_lwps (1, event_child);
2529 cancel_breakpoints ();
2531 delete_breakpoint (event_child->exit_jump_pad_bkpt);
2532 event_child->exit_jump_pad_bkpt = NULL;
2534 unstop_all_lwps (1, event_child);
2536 gdb_assert (event_child->suspended >= 0);
2540 if (event_child->collecting_fast_tracepoint == 0)
2544 "fast tracepoint finished "
2545 "collecting successfully.\n");
2547 /* We may have a deferred signal to report. */
2548 if (dequeue_one_deferred_signal (event_child, &w))
2551 fprintf (stderr, "dequeued one signal.\n");
2556 fprintf (stderr, "no deferred signals.\n");
2558 if (stabilizing_threads)
2560 ourstatus->kind = TARGET_WAITKIND_STOPPED;
2561 ourstatus->value.sig = GDB_SIGNAL_0;
2562 return ptid_of (event_child);
2568 /* Check whether GDB would be interested in this event. */
2570 /* If GDB is not interested in this signal, don't stop other
2571 threads, and don't report it to GDB. Just resume the inferior
2572 right away. We do this for threading-related signals as well as
2573 any that GDB specifically requested we ignore. But never ignore
2574 SIGSTOP if we sent it ourselves, and do not ignore signals when
2575 stepping - they may require special handling to skip the signal
2577 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
2580 && current_inferior->last_resume_kind != resume_step
2582 #if defined (USE_THREAD_DB) && !defined (__ANDROID__)
2583 (current_process ()->private->thread_db != NULL
2584 && (WSTOPSIG (w) == __SIGRTMIN
2585 || WSTOPSIG (w) == __SIGRTMIN + 1))
2588 (pass_signals[gdb_signal_from_host (WSTOPSIG (w))]
2589 && !(WSTOPSIG (w) == SIGSTOP
2590 && current_inferior->last_resume_kind == resume_stop))))
2592 siginfo_t info, *info_p;
2595 fprintf (stderr, "Ignored signal %d for LWP %ld.\n",
2596 WSTOPSIG (w), lwpid_of (event_child));
2598 if (ptrace (PTRACE_GETSIGINFO, lwpid_of (event_child), 0, &info) == 0)
2602 linux_resume_one_lwp (event_child, event_child->stepping,
2603 WSTOPSIG (w), info_p);
2607 /* If GDB wanted this thread to single step, we always want to
2608 report the SIGTRAP, and let GDB handle it. Watchpoints should
2609 always be reported. So should signals we can't explain. A
2610 SIGTRAP we can't explain could be a GDB breakpoint --- we may or
2611 not support Z0 breakpoints. If we do, we're be able to handle
2612 GDB breakpoints on top of internal breakpoints, by handling the
2613 internal breakpoint and still reporting the event to GDB. If we
2614 don't, we're out of luck, GDB won't see the breakpoint hit. */
2615 report_to_gdb = (!maybe_internal_trap
2616 || current_inferior->last_resume_kind == resume_step
2617 || event_child->stopped_by_watchpoint
2618 || (!step_over_finished
2619 && !bp_explains_trap && !trace_event)
2620 || (gdb_breakpoint_here (event_child->stop_pc)
2621 && gdb_condition_true_at_breakpoint (event_child->stop_pc)));
2623 /* We found no reason GDB would want us to stop. We either hit one
2624 of our own breakpoints, or finished an internal step GDB
2625 shouldn't know about. */
2630 if (bp_explains_trap)
2631 fprintf (stderr, "Hit a gdbserver breakpoint.\n");
2632 if (step_over_finished)
2633 fprintf (stderr, "Step-over finished.\n");
2635 fprintf (stderr, "Tracepoint event.\n");
2638 /* We're not reporting this breakpoint to GDB, so apply the
2639 decr_pc_after_break adjustment to the inferior's regcache
2642 if (the_low_target.set_pc != NULL)
2644 struct regcache *regcache
2645 = get_thread_regcache (get_lwp_thread (event_child), 1);
2646 (*the_low_target.set_pc) (regcache, event_child->stop_pc);
2649 /* We may have finished stepping over a breakpoint. If so,
2650 we've stopped and suspended all LWPs momentarily except the
2651 stepping one. This is where we resume them all again. We're
2652 going to keep waiting, so use proceed, which handles stepping
2653 over the next breakpoint. */
2655 fprintf (stderr, "proceeding all threads.\n");
2657 if (step_over_finished)
2658 unsuspend_all_lwps (event_child);
2660 proceed_all_lwps ();
2666 if (current_inferior->last_resume_kind == resume_step)
2667 fprintf (stderr, "GDB wanted to single-step, reporting event.\n");
2668 if (event_child->stopped_by_watchpoint)
2669 fprintf (stderr, "Stopped by watchpoint.\n");
2670 if (gdb_breakpoint_here (event_child->stop_pc))
2671 fprintf (stderr, "Stopped by GDB breakpoint.\n");
2673 fprintf (stderr, "Hit a non-gdbserver trap event.\n");
2676 /* Alright, we're going to report a stop. */
2678 if (!non_stop && !stabilizing_threads)
2680 /* In all-stop, stop all threads. */
2681 stop_all_lwps (0, NULL);
2683 /* If we're not waiting for a specific LWP, choose an event LWP
2684 from among those that have had events. Giving equal priority
2685 to all LWPs that have had events helps prevent
2687 if (ptid_equal (ptid, minus_one_ptid))
2689 event_child->status_pending_p = 1;
2690 event_child->status_pending = w;
2692 select_event_lwp (&event_child);
2694 event_child->status_pending_p = 0;
2695 w = event_child->status_pending;
2698 /* Now that we've selected our final event LWP, cancel any
2699 breakpoints in other LWPs that have hit a GDB breakpoint.
2700 See the comment in cancel_breakpoints_callback to find out
2702 find_inferior (&all_lwps, cancel_breakpoints_callback, event_child);
2704 /* If we were going a step-over, all other threads but the stepping one
2705 had been paused in start_step_over, with their suspend counts
2706 incremented. We don't want to do a full unstop/unpause, because we're
2707 in all-stop mode (so we want threads stopped), but we still need to
2708 unsuspend the other threads, to decrement their `suspended' count
2710 if (step_over_finished)
2711 unsuspend_all_lwps (event_child);
2713 /* Stabilize threads (move out of jump pads). */
2714 stabilize_threads ();
2718 /* If we just finished a step-over, then all threads had been
2719 momentarily paused. In all-stop, that's fine, we want
2720 threads stopped by now anyway. In non-stop, we need to
2721 re-resume threads that GDB wanted to be running. */
2722 if (step_over_finished)
2723 unstop_all_lwps (1, event_child);
2726 ourstatus->kind = TARGET_WAITKIND_STOPPED;
2728 if (current_inferior->last_resume_kind == resume_stop
2729 && WSTOPSIG (w) == SIGSTOP)
2731 /* A thread that has been requested to stop by GDB with vCont;t,
2732 and it stopped cleanly, so report as SIG0. The use of
2733 SIGSTOP is an implementation detail. */
2734 ourstatus->value.sig = GDB_SIGNAL_0;
2736 else if (current_inferior->last_resume_kind == resume_stop
2737 && WSTOPSIG (w) != SIGSTOP)
2739 /* A thread that has been requested to stop by GDB with vCont;t,
2740 but, it stopped for other reasons. */
2741 ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w));
2745 ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w));
2748 gdb_assert (ptid_equal (step_over_bkpt, null_ptid));
2751 fprintf (stderr, "linux_wait ret = %s, %d, %d\n",
2752 target_pid_to_str (ptid_of (event_child)),
2754 ourstatus->value.sig);
2756 return ptid_of (event_child);
2759 /* Get rid of any pending event in the pipe. */
2761 async_file_flush (void)
2767 ret = read (linux_event_pipe[0], &buf, 1);
2768 while (ret >= 0 || (ret == -1 && errno == EINTR));
2771 /* Put something in the pipe, so the event loop wakes up. */
2773 async_file_mark (void)
2777 async_file_flush ();
2780 ret = write (linux_event_pipe[1], "+", 1);
2781 while (ret == 0 || (ret == -1 && errno == EINTR));
2783 /* Ignore EAGAIN. If the pipe is full, the event loop will already
2784 be awakened anyway. */
2788 linux_wait (ptid_t ptid,
2789 struct target_waitstatus *ourstatus, int target_options)
2794 fprintf (stderr, "linux_wait: [%s]\n", target_pid_to_str (ptid));
2796 /* Flush the async file first. */
2797 if (target_is_async_p ())
2798 async_file_flush ();
2800 event_ptid = linux_wait_1 (ptid, ourstatus, target_options);
2802 /* If at least one stop was reported, there may be more. A single
2803 SIGCHLD can signal more than one child stop. */
2804 if (target_is_async_p ()
2805 && (target_options & TARGET_WNOHANG) != 0
2806 && !ptid_equal (event_ptid, null_ptid))
2812 /* Send a signal to an LWP. */
2815 kill_lwp (unsigned long lwpid, int signo)
2817 /* Use tkill, if possible, in case we are using nptl threads. If tkill
2818 fails, then we are not using nptl threads and we should be using kill. */
2822 static int tkill_failed;
2829 ret = syscall (__NR_tkill, lwpid, signo);
2830 if (errno != ENOSYS)
2837 return kill (lwpid, signo);
2841 linux_stop_lwp (struct lwp_info *lwp)
2847 send_sigstop (struct lwp_info *lwp)
2851 pid = lwpid_of (lwp);
2853 /* If we already have a pending stop signal for this process, don't
2855 if (lwp->stop_expected)
2858 fprintf (stderr, "Have pending sigstop for lwp %d\n", pid);
2864 fprintf (stderr, "Sending sigstop to lwp %d\n", pid);
2866 lwp->stop_expected = 1;
2867 kill_lwp (pid, SIGSTOP);
2871 send_sigstop_callback (struct inferior_list_entry *entry, void *except)
2873 struct lwp_info *lwp = (struct lwp_info *) entry;
2875 /* Ignore EXCEPT. */
2886 /* Increment the suspend count of an LWP, and stop it, if not stopped
2889 suspend_and_send_sigstop_callback (struct inferior_list_entry *entry,
2892 struct lwp_info *lwp = (struct lwp_info *) entry;
2894 /* Ignore EXCEPT. */
2900 return send_sigstop_callback (entry, except);
2904 mark_lwp_dead (struct lwp_info *lwp, int wstat)
2906 /* It's dead, really. */
2909 /* Store the exit status for later. */
2910 lwp->status_pending_p = 1;
2911 lwp->status_pending = wstat;
2913 /* Prevent trying to stop it. */
2916 /* No further stops are expected from a dead lwp. */
2917 lwp->stop_expected = 0;
2921 wait_for_sigstop (struct inferior_list_entry *entry)
2923 struct lwp_info *lwp = (struct lwp_info *) entry;
2924 struct thread_info *saved_inferior;
2933 fprintf (stderr, "wait_for_sigstop: LWP %ld already stopped\n",
2938 saved_inferior = current_inferior;
2939 if (saved_inferior != NULL)
2940 saved_tid = ((struct inferior_list_entry *) saved_inferior)->id;
2942 saved_tid = null_ptid; /* avoid bogus unused warning */
2944 ptid = lwp->head.id;
2947 fprintf (stderr, "wait_for_sigstop: pulling one event\n");
2949 pid = linux_wait_for_event (ptid, &wstat, __WALL);
2951 /* If we stopped with a non-SIGSTOP signal, save it for later
2952 and record the pending SIGSTOP. If the process exited, just
2954 if (WIFSTOPPED (wstat))
2957 fprintf (stderr, "LWP %ld stopped with signal %d\n",
2958 lwpid_of (lwp), WSTOPSIG (wstat));
2960 if (WSTOPSIG (wstat) != SIGSTOP)
2963 fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n",
2964 lwpid_of (lwp), wstat);
2966 lwp->status_pending_p = 1;
2967 lwp->status_pending = wstat;
2973 fprintf (stderr, "Process %d exited while stopping LWPs\n", pid);
2975 lwp = find_lwp_pid (pid_to_ptid (pid));
2978 /* Leave this status pending for the next time we're able to
2979 report it. In the mean time, we'll report this lwp as
2980 dead to GDB, so GDB doesn't try to read registers and
2981 memory from it. This can only happen if this was the
2982 last thread of the process; otherwise, PID is removed
2983 from the thread tables before linux_wait_for_event
2985 mark_lwp_dead (lwp, wstat);
2989 if (saved_inferior == NULL || linux_thread_alive (saved_tid))
2990 current_inferior = saved_inferior;
2994 fprintf (stderr, "Previously current thread died.\n");
2998 /* We can't change the current inferior behind GDB's back,
2999 otherwise, a subsequent command may apply to the wrong
3001 current_inferior = NULL;
3005 /* Set a valid thread as current. */
3006 set_desired_inferior (0);
3011 /* Returns true if LWP ENTRY is stopped in a jump pad, and we can't
3012 move it out, because we need to report the stop event to GDB. For
3013 example, if the user puts a breakpoint in the jump pad, it's
3014 because she wants to debug it. */
3017 stuck_in_jump_pad_callback (struct inferior_list_entry *entry, void *data)
3019 struct lwp_info *lwp = (struct lwp_info *) entry;
3020 struct thread_info *thread = get_lwp_thread (lwp);
3022 gdb_assert (lwp->suspended == 0);
3023 gdb_assert (lwp->stopped);
3025 /* Allow debugging the jump pad, gdb_collect, etc.. */
3026 return (supports_fast_tracepoints ()
3027 && agent_loaded_p ()
3028 && (gdb_breakpoint_here (lwp->stop_pc)
3029 || lwp->stopped_by_watchpoint
3030 || thread->last_resume_kind == resume_step)
3031 && linux_fast_tracepoint_collecting (lwp, NULL));
3035 move_out_of_jump_pad_callback (struct inferior_list_entry *entry)
3037 struct lwp_info *lwp = (struct lwp_info *) entry;
3038 struct thread_info *thread = get_lwp_thread (lwp);
3041 gdb_assert (lwp->suspended == 0);
3042 gdb_assert (lwp->stopped);
3044 wstat = lwp->status_pending_p ? &lwp->status_pending : NULL;
3046 /* Allow debugging the jump pad, gdb_collect, etc. */
3047 if (!gdb_breakpoint_here (lwp->stop_pc)
3048 && !lwp->stopped_by_watchpoint
3049 && thread->last_resume_kind != resume_step
3050 && maybe_move_out_of_jump_pad (lwp, wstat))
3054 "LWP %ld needs stabilizing (in jump pad)\n",
3059 lwp->status_pending_p = 0;
3060 enqueue_one_deferred_signal (lwp, wstat);
3064 "Signal %d for LWP %ld deferred "
3066 WSTOPSIG (*wstat), lwpid_of (lwp));
3069 linux_resume_one_lwp (lwp, 0, 0, NULL);
3076 lwp_running (struct inferior_list_entry *entry, void *data)
3078 struct lwp_info *lwp = (struct lwp_info *) entry;
3087 /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
3088 If SUSPEND, then also increase the suspend count of every LWP,
3092 stop_all_lwps (int suspend, struct lwp_info *except)
3094 /* Should not be called recursively. */
3095 gdb_assert (stopping_threads == NOT_STOPPING_THREADS);
3097 stopping_threads = (suspend
3098 ? STOPPING_AND_SUSPENDING_THREADS
3099 : STOPPING_THREADS);
3102 find_inferior (&all_lwps, suspend_and_send_sigstop_callback, except);
3104 find_inferior (&all_lwps, send_sigstop_callback, except);
3105 for_each_inferior (&all_lwps, wait_for_sigstop);
3106 stopping_threads = NOT_STOPPING_THREADS;
3109 /* Resume execution of the inferior process.
3110 If STEP is nonzero, single-step it.
3111 If SIGNAL is nonzero, give it that signal. */
3114 linux_resume_one_lwp (struct lwp_info *lwp,
3115 int step, int signal, siginfo_t *info)
3117 struct thread_info *saved_inferior;
3118 int fast_tp_collecting;
3120 if (lwp->stopped == 0)
3123 fast_tp_collecting = lwp->collecting_fast_tracepoint;
3125 gdb_assert (!stabilizing_threads || fast_tp_collecting);
3127 /* Cancel actions that rely on GDB not changing the PC (e.g., the
3128 user used the "jump" command, or "set $pc = foo"). */
3129 if (lwp->stop_pc != get_pc (lwp))
3131 /* Collecting 'while-stepping' actions doesn't make sense
3133 release_while_stepping_state_list (get_lwp_thread (lwp));
3136 /* If we have pending signals or status, and a new signal, enqueue the
3137 signal. Also enqueue the signal if we are waiting to reinsert a
3138 breakpoint; it will be picked up again below. */
3140 && (lwp->status_pending_p
3141 || lwp->pending_signals != NULL
3142 || lwp->bp_reinsert != 0
3143 || fast_tp_collecting))
3145 struct pending_signals *p_sig;
3146 p_sig = xmalloc (sizeof (*p_sig));
3147 p_sig->prev = lwp->pending_signals;
3148 p_sig->signal = signal;
3150 memset (&p_sig->info, 0, sizeof (siginfo_t));
3152 memcpy (&p_sig->info, info, sizeof (siginfo_t));
3153 lwp->pending_signals = p_sig;
3156 if (lwp->status_pending_p)
3159 fprintf (stderr, "Not resuming lwp %ld (%s, signal %d, stop %s);"
3160 " has pending status\n",
3161 lwpid_of (lwp), step ? "step" : "continue", signal,
3162 lwp->stop_expected ? "expected" : "not expected");
3166 saved_inferior = current_inferior;
3167 current_inferior = get_lwp_thread (lwp);
3170 fprintf (stderr, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
3171 lwpid_of (lwp), step ? "step" : "continue", signal,
3172 lwp->stop_expected ? "expected" : "not expected");
3174 /* This bit needs some thinking about. If we get a signal that
3175 we must report while a single-step reinsert is still pending,
3176 we often end up resuming the thread. It might be better to
3177 (ew) allow a stack of pending events; then we could be sure that
3178 the reinsert happened right away and not lose any signals.
3180 Making this stack would also shrink the window in which breakpoints are
3181 uninserted (see comment in linux_wait_for_lwp) but not enough for
3182 complete correctness, so it won't solve that problem. It may be
3183 worthwhile just to solve this one, however. */
3184 if (lwp->bp_reinsert != 0)
3187 fprintf (stderr, " pending reinsert at 0x%s\n",
3188 paddress (lwp->bp_reinsert));
3190 if (lwp->bp_reinsert != 0 && can_hardware_single_step ())
3192 if (fast_tp_collecting == 0)
3195 fprintf (stderr, "BAD - reinserting but not stepping.\n");
3197 fprintf (stderr, "BAD - reinserting and suspended(%d).\n",
3204 /* Postpone any pending signal. It was enqueued above. */
3208 if (fast_tp_collecting == 1)
3212 lwp %ld wants to get out of fast tracepoint jump pad (exit-jump-pad-bkpt)\n",
3215 /* Postpone any pending signal. It was enqueued above. */
3218 else if (fast_tp_collecting == 2)
3222 lwp %ld wants to get out of fast tracepoint jump pad single-stepping\n",
3225 if (can_hardware_single_step ())
3228 fatal ("moving out of jump pad single-stepping"
3229 " not implemented on this target");
3231 /* Postpone any pending signal. It was enqueued above. */
3235 /* If we have while-stepping actions in this thread set it stepping.
3236 If we have a signal to deliver, it may or may not be set to
3237 SIG_IGN, we don't know. Assume so, and allow collecting
3238 while-stepping into a signal handler. A possible smart thing to
3239 do would be to set an internal breakpoint at the signal return
3240 address, continue, and carry on catching this while-stepping
3241 action only when that breakpoint is hit. A future
3243 if (get_lwp_thread (lwp)->while_stepping != NULL
3244 && can_hardware_single_step ())
3248 "lwp %ld has a while-stepping action -> forcing step.\n",
3253 if (debug_threads && the_low_target.get_pc != NULL)
3255 struct regcache *regcache = get_thread_regcache (current_inferior, 1);
3256 CORE_ADDR pc = (*the_low_target.get_pc) (regcache);
3257 fprintf (stderr, " resuming from pc 0x%lx\n", (long) pc);
3260 /* If we have pending signals, consume one unless we are trying to
3261 reinsert a breakpoint or we're trying to finish a fast tracepoint
3263 if (lwp->pending_signals != NULL
3264 && lwp->bp_reinsert == 0
3265 && fast_tp_collecting == 0)
3267 struct pending_signals **p_sig;
3269 p_sig = &lwp->pending_signals;
3270 while ((*p_sig)->prev != NULL)
3271 p_sig = &(*p_sig)->prev;
3273 signal = (*p_sig)->signal;
3274 if ((*p_sig)->info.si_signo != 0)
3275 ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &(*p_sig)->info);
3281 if (the_low_target.prepare_to_resume != NULL)
3282 the_low_target.prepare_to_resume (lwp);
3284 regcache_invalidate_one ((struct inferior_list_entry *)
3285 get_lwp_thread (lwp));
3288 lwp->stopped_by_watchpoint = 0;
3289 lwp->stepping = step;
3290 ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (lwp), 0,
3291 /* Coerce to a uintptr_t first to avoid potential gcc warning
3292 of coercing an 8 byte integer to a 4 byte pointer. */
3293 (PTRACE_ARG4_TYPE) (uintptr_t) signal);
3295 current_inferior = saved_inferior;
3298 /* ESRCH from ptrace either means that the thread was already
3299 running (an error) or that it is gone (a race condition). If
3300 it's gone, we will get a notification the next time we wait,
3301 so we can ignore the error. We could differentiate these
3302 two, but it's tricky without waiting; the thread still exists
3303 as a zombie, so sending it signal 0 would succeed. So just
3308 perror_with_name ("ptrace");
3312 struct thread_resume_array
3314 struct thread_resume *resume;
3318 /* This function is called once per thread. We look up the thread
3319 in RESUME_PTR, and mark the thread with a pointer to the appropriate
3322 This algorithm is O(threads * resume elements), but resume elements
3323 is small (and will remain small at least until GDB supports thread
3326 linux_set_resume_request (struct inferior_list_entry *entry, void *arg)
3328 struct lwp_info *lwp;
3329 struct thread_info *thread;
3331 struct thread_resume_array *r;
3333 thread = (struct thread_info *) entry;
3334 lwp = get_thread_lwp (thread);
3337 for (ndx = 0; ndx < r->n; ndx++)
3339 ptid_t ptid = r->resume[ndx].thread;
3340 if (ptid_equal (ptid, minus_one_ptid)
3341 || ptid_equal (ptid, entry->id)
3342 || (ptid_is_pid (ptid)
3343 && (ptid_get_pid (ptid) == pid_of (lwp)))
3344 || (ptid_get_lwp (ptid) == -1
3345 && (ptid_get_pid (ptid) == pid_of (lwp))))
3347 if (r->resume[ndx].kind == resume_stop
3348 && thread->last_resume_kind == resume_stop)
3351 fprintf (stderr, "already %s LWP %ld at GDB's request\n",
3352 thread->last_status.kind == TARGET_WAITKIND_STOPPED
3360 lwp->resume = &r->resume[ndx];
3361 thread->last_resume_kind = lwp->resume->kind;
3363 /* If we had a deferred signal to report, dequeue one now.
3364 This can happen if LWP gets more than one signal while
3365 trying to get out of a jump pad. */
3367 && !lwp->status_pending_p
3368 && dequeue_one_deferred_signal (lwp, &lwp->status_pending))
3370 lwp->status_pending_p = 1;
3374 "Dequeueing deferred signal %d for LWP %ld, "
3375 "leaving status pending.\n",
3376 WSTOPSIG (lwp->status_pending), lwpid_of (lwp));
3383 /* No resume action for this thread. */
3390 /* Set *FLAG_P if this lwp has an interesting status pending. */
3392 resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p)
3394 struct lwp_info *lwp = (struct lwp_info *) entry;
3396 /* LWPs which will not be resumed are not interesting, because
3397 we might not wait for them next time through linux_wait. */
3398 if (lwp->resume == NULL)
3401 if (lwp->status_pending_p)
3402 * (int *) flag_p = 1;
3407 /* Return 1 if this lwp that GDB wants running is stopped at an
3408 internal breakpoint that we need to step over. It assumes that any
3409 required STOP_PC adjustment has already been propagated to the
3410 inferior's regcache. */
3413 need_step_over_p (struct inferior_list_entry *entry, void *dummy)
3415 struct lwp_info *lwp = (struct lwp_info *) entry;
3416 struct thread_info *thread;
3417 struct thread_info *saved_inferior;
3420 /* LWPs which will not be resumed are not interesting, because we
3421 might not wait for them next time through linux_wait. */
3427 "Need step over [LWP %ld]? Ignoring, not stopped\n",
3432 thread = get_lwp_thread (lwp);
3434 if (thread->last_resume_kind == resume_stop)
3438 "Need step over [LWP %ld]? Ignoring, should remain stopped\n",
3443 gdb_assert (lwp->suspended >= 0);
3449 "Need step over [LWP %ld]? Ignoring, suspended\n",
3454 if (!lwp->need_step_over)
3458 "Need step over [LWP %ld]? No\n", lwpid_of (lwp));
3461 if (lwp->status_pending_p)
3465 "Need step over [LWP %ld]? Ignoring, has pending status.\n",
3470 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
3474 /* If the PC has changed since we stopped, then don't do anything,
3475 and let the breakpoint/tracepoint be hit. This happens if, for
3476 instance, GDB handled the decr_pc_after_break subtraction itself,
3477 GDB is OOL stepping this thread, or the user has issued a "jump"
3478 command, or poked thread's registers herself. */
3479 if (pc != lwp->stop_pc)
3483 "Need step over [LWP %ld]? Cancelling, PC was changed. "
3484 "Old stop_pc was 0x%s, PC is now 0x%s\n",
3485 lwpid_of (lwp), paddress (lwp->stop_pc), paddress (pc));
3487 lwp->need_step_over = 0;
3491 saved_inferior = current_inferior;
3492 current_inferior = thread;
3494 /* We can only step over breakpoints we know about. */
3495 if (breakpoint_here (pc) || fast_tracepoint_jump_here (pc))
3497 /* Don't step over a breakpoint that GDB expects to hit
3498 though. If the condition is being evaluated on the target's side
3499 and it evaluate to false, step over this breakpoint as well. */
3500 if (gdb_breakpoint_here (pc)
3501 && gdb_condition_true_at_breakpoint (pc))
3505 "Need step over [LWP %ld]? yes, but found"
3506 " GDB breakpoint at 0x%s; skipping step over\n",
3507 lwpid_of (lwp), paddress (pc));
3509 current_inferior = saved_inferior;
3516 "Need step over [LWP %ld]? yes, "
3517 "found breakpoint at 0x%s\n",
3518 lwpid_of (lwp), paddress (pc));
3520 /* We've found an lwp that needs stepping over --- return 1 so
3521 that find_inferior stops looking. */
3522 current_inferior = saved_inferior;
3524 /* If the step over is cancelled, this is set again. */
3525 lwp->need_step_over = 0;
3530 current_inferior = saved_inferior;
3534 "Need step over [LWP %ld]? No, no breakpoint found at 0x%s\n",
3535 lwpid_of (lwp), paddress (pc));
3540 /* Start a step-over operation on LWP. When LWP stopped at a
3541 breakpoint, to make progress, we need to remove the breakpoint out
3542 of the way. If we let other threads run while we do that, they may
3543 pass by the breakpoint location and miss hitting it. To avoid
3544 that, a step-over momentarily stops all threads while LWP is
3545 single-stepped while the breakpoint is temporarily uninserted from
3546 the inferior. When the single-step finishes, we reinsert the
3547 breakpoint, and let all threads that are supposed to be running,
3550 On targets that don't support hardware single-step, we don't
3551 currently support full software single-stepping. Instead, we only
3552 support stepping over the thread event breakpoint, by asking the
3553 low target where to place a reinsert breakpoint. Since this
3554 routine assumes the breakpoint being stepped over is a thread event
3555 breakpoint, it usually assumes the return address of the current
3556 function is a good enough place to set the reinsert breakpoint. */
3559 start_step_over (struct lwp_info *lwp)
3561 struct thread_info *saved_inferior;
3567 "Starting step-over on LWP %ld. Stopping all threads\n",
3570 stop_all_lwps (1, lwp);
3571 gdb_assert (lwp->suspended == 0);
3574 fprintf (stderr, "Done stopping all threads for step-over.\n");
3576 /* Note, we should always reach here with an already adjusted PC,
3577 either by GDB (if we're resuming due to GDB's request), or by our
3578 caller, if we just finished handling an internal breakpoint GDB
3579 shouldn't care about. */
3582 saved_inferior = current_inferior;
3583 current_inferior = get_lwp_thread (lwp);
3585 lwp->bp_reinsert = pc;
3586 uninsert_breakpoints_at (pc);
3587 uninsert_fast_tracepoint_jumps_at (pc);
3589 if (can_hardware_single_step ())
3595 CORE_ADDR raddr = (*the_low_target.breakpoint_reinsert_addr) ();
3596 set_reinsert_breakpoint (raddr);
3600 current_inferior = saved_inferior;
3602 linux_resume_one_lwp (lwp, step, 0, NULL);
3604 /* Require next event from this LWP. */
3605 step_over_bkpt = lwp->head.id;
3609 /* Finish a step-over. Reinsert the breakpoint we had uninserted in
3610 start_step_over, if still there, and delete any reinsert
3611 breakpoints we've set, on non hardware single-step targets. */
3614 finish_step_over (struct lwp_info *lwp)
3616 if (lwp->bp_reinsert != 0)
3619 fprintf (stderr, "Finished step over.\n");
3621 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
3622 may be no breakpoint to reinsert there by now. */
3623 reinsert_breakpoints_at (lwp->bp_reinsert);
3624 reinsert_fast_tracepoint_jumps_at (lwp->bp_reinsert);
3626 lwp->bp_reinsert = 0;
3628 /* Delete any software-single-step reinsert breakpoints. No
3629 longer needed. We don't have to worry about other threads
3630 hitting this trap, and later not being able to explain it,
3631 because we were stepping over a breakpoint, and we hold all
3632 threads but LWP stopped while doing that. */
3633 if (!can_hardware_single_step ())
3634 delete_reinsert_breakpoints ();
3636 step_over_bkpt = null_ptid;
3643 /* This function is called once per thread. We check the thread's resume
3644 request, which will tell us whether to resume, step, or leave the thread
3645 stopped; and what signal, if any, it should be sent.
3647 For threads which we aren't explicitly told otherwise, we preserve
3648 the stepping flag; this is used for stepping over gdbserver-placed
3651 If pending_flags was set in any thread, we queue any needed
3652 signals, since we won't actually resume. We already have a pending
3653 event to report, so we don't need to preserve any step requests;
3654 they should be re-issued if necessary. */
3657 linux_resume_one_thread (struct inferior_list_entry *entry, void *arg)
3659 struct lwp_info *lwp;
3660 struct thread_info *thread;
3662 int leave_all_stopped = * (int *) arg;
3665 thread = (struct thread_info *) entry;
3666 lwp = get_thread_lwp (thread);
3668 if (lwp->resume == NULL)
3671 if (lwp->resume->kind == resume_stop)
3674 fprintf (stderr, "resume_stop request for LWP %ld\n", lwpid_of (lwp));
3679 fprintf (stderr, "stopping LWP %ld\n", lwpid_of (lwp));
3681 /* Stop the thread, and wait for the event asynchronously,
3682 through the event loop. */
3688 fprintf (stderr, "already stopped LWP %ld\n",
3691 /* The LWP may have been stopped in an internal event that
3692 was not meant to be notified back to GDB (e.g., gdbserver
3693 breakpoint), so we should be reporting a stop event in
3696 /* If the thread already has a pending SIGSTOP, this is a
3697 no-op. Otherwise, something later will presumably resume
3698 the thread and this will cause it to cancel any pending
3699 operation, due to last_resume_kind == resume_stop. If
3700 the thread already has a pending status to report, we
3701 will still report it the next time we wait - see
3702 status_pending_p_callback. */
3704 /* If we already have a pending signal to report, then
3705 there's no need to queue a SIGSTOP, as this means we're
3706 midway through moving the LWP out of the jumppad, and we
3707 will report the pending signal as soon as that is
3709 if (lwp->pending_signals_to_report == NULL)
3713 /* For stop requests, we're done. */
3715 thread->last_status.kind = TARGET_WAITKIND_IGNORE;
3719 /* If this thread which is about to be resumed has a pending status,
3720 then don't resume any threads - we can just report the pending
3721 status. Make sure to queue any signals that would otherwise be
3722 sent. In all-stop mode, we do this decision based on if *any*
3723 thread has a pending status. If there's a thread that needs the
3724 step-over-breakpoint dance, then don't resume any other thread
3725 but that particular one. */
3726 leave_pending = (lwp->status_pending_p || leave_all_stopped);
3731 fprintf (stderr, "resuming LWP %ld\n", lwpid_of (lwp));
3733 step = (lwp->resume->kind == resume_step);
3734 linux_resume_one_lwp (lwp, step, lwp->resume->sig, NULL);
3739 fprintf (stderr, "leaving LWP %ld stopped\n", lwpid_of (lwp));
3741 /* If we have a new signal, enqueue the signal. */
3742 if (lwp->resume->sig != 0)
3744 struct pending_signals *p_sig;
3745 p_sig = xmalloc (sizeof (*p_sig));
3746 p_sig->prev = lwp->pending_signals;
3747 p_sig->signal = lwp->resume->sig;
3748 memset (&p_sig->info, 0, sizeof (siginfo_t));
3750 /* If this is the same signal we were previously stopped by,
3751 make sure to queue its siginfo. We can ignore the return
3752 value of ptrace; if it fails, we'll skip
3753 PTRACE_SETSIGINFO. */
3754 if (WIFSTOPPED (lwp->last_status)
3755 && WSTOPSIG (lwp->last_status) == lwp->resume->sig)
3756 ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info);
3758 lwp->pending_signals = p_sig;
3762 thread->last_status.kind = TARGET_WAITKIND_IGNORE;
3768 linux_resume (struct thread_resume *resume_info, size_t n)
3770 struct thread_resume_array array = { resume_info, n };
3771 struct lwp_info *need_step_over = NULL;
3773 int leave_all_stopped;
3775 find_inferior (&all_threads, linux_set_resume_request, &array);
3777 /* If there is a thread which would otherwise be resumed, which has
3778 a pending status, then don't resume any threads - we can just
3779 report the pending status. Make sure to queue any signals that
3780 would otherwise be sent. In non-stop mode, we'll apply this
3781 logic to each thread individually. We consume all pending events
3782 before considering to start a step-over (in all-stop). */
3785 find_inferior (&all_lwps, resume_status_pending_p, &any_pending);
3787 /* If there is a thread which would otherwise be resumed, which is
3788 stopped at a breakpoint that needs stepping over, then don't
3789 resume any threads - have it step over the breakpoint with all
3790 other threads stopped, then resume all threads again. Make sure
3791 to queue any signals that would otherwise be delivered or
3793 if (!any_pending && supports_breakpoints ())
3795 = (struct lwp_info *) find_inferior (&all_lwps,
3796 need_step_over_p, NULL);
3798 leave_all_stopped = (need_step_over != NULL || any_pending);
3802 if (need_step_over != NULL)
3803 fprintf (stderr, "Not resuming all, need step over\n");
3804 else if (any_pending)
3806 "Not resuming, all-stop and found "
3807 "an LWP with pending status\n");
3809 fprintf (stderr, "Resuming, no pending status or step over needed\n");
3812 /* Even if we're leaving threads stopped, queue all signals we'd
3813 otherwise deliver. */
3814 find_inferior (&all_threads, linux_resume_one_thread, &leave_all_stopped);
3817 start_step_over (need_step_over);
3820 /* This function is called once per thread. We check the thread's
3821 last resume request, which will tell us whether to resume, step, or
3822 leave the thread stopped. Any signal the client requested to be
3823 delivered has already been enqueued at this point.
3825 If any thread that GDB wants running is stopped at an internal
3826 breakpoint that needs stepping over, we start a step-over operation
3827 on that particular thread, and leave all others stopped. */
3830 proceed_one_lwp (struct inferior_list_entry *entry, void *except)
3832 struct lwp_info *lwp = (struct lwp_info *) entry;
3833 struct thread_info *thread;
3841 "proceed_one_lwp: lwp %ld\n", lwpid_of (lwp));
3846 fprintf (stderr, " LWP %ld already running\n", lwpid_of (lwp));
3850 thread = get_lwp_thread (lwp);
3852 if (thread->last_resume_kind == resume_stop
3853 && thread->last_status.kind != TARGET_WAITKIND_IGNORE)
3856 fprintf (stderr, " client wants LWP to remain %ld stopped\n",
3861 if (lwp->status_pending_p)
3864 fprintf (stderr, " LWP %ld has pending status, leaving stopped\n",
3869 gdb_assert (lwp->suspended >= 0);
3874 fprintf (stderr, " LWP %ld is suspended\n", lwpid_of (lwp));
3878 if (thread->last_resume_kind == resume_stop
3879 && lwp->pending_signals_to_report == NULL
3880 && lwp->collecting_fast_tracepoint == 0)
3882 /* We haven't reported this LWP as stopped yet (otherwise, the
3883 last_status.kind check above would catch it, and we wouldn't
3884 reach here. This LWP may have been momentarily paused by a
3885 stop_all_lwps call while handling for example, another LWP's
3886 step-over. In that case, the pending expected SIGSTOP signal
3887 that was queued at vCont;t handling time will have already
3888 been consumed by wait_for_sigstop, and so we need to requeue
3889 another one here. Note that if the LWP already has a SIGSTOP
3890 pending, this is a no-op. */
3894 "Client wants LWP %ld to stop. "
3895 "Making sure it has a SIGSTOP pending\n",
3901 step = thread->last_resume_kind == resume_step;
3902 linux_resume_one_lwp (lwp, step, 0, NULL);
3907 unsuspend_and_proceed_one_lwp (struct inferior_list_entry *entry, void *except)
3909 struct lwp_info *lwp = (struct lwp_info *) entry;
3915 gdb_assert (lwp->suspended >= 0);
3917 return proceed_one_lwp (entry, except);
3920 /* When we finish a step-over, set threads running again. If there's
3921 another thread that may need a step-over, now's the time to start
3922 it. Eventually, we'll move all threads past their breakpoints. */
3925 proceed_all_lwps (void)
3927 struct lwp_info *need_step_over;
3929 /* If there is a thread which would otherwise be resumed, which is
3930 stopped at a breakpoint that needs stepping over, then don't
3931 resume any threads - have it step over the breakpoint with all
3932 other threads stopped, then resume all threads again. */
3934 if (supports_breakpoints ())
3937 = (struct lwp_info *) find_inferior (&all_lwps,
3938 need_step_over_p, NULL);
3940 if (need_step_over != NULL)
3943 fprintf (stderr, "proceed_all_lwps: found "
3944 "thread %ld needing a step-over\n",
3945 lwpid_of (need_step_over));
3947 start_step_over (need_step_over);
3953 fprintf (stderr, "Proceeding, no step-over needed\n");
3955 find_inferior (&all_lwps, proceed_one_lwp, NULL);
3958 /* Stopped LWPs that the client wanted to be running, that don't have
3959 pending statuses, are set to run again, except for EXCEPT, if not
3960 NULL. This undoes a stop_all_lwps call. */
3963 unstop_all_lwps (int unsuspend, struct lwp_info *except)
3969 "unstopping all lwps, except=(LWP %ld)\n", lwpid_of (except));
3972 "unstopping all lwps\n");
3976 find_inferior (&all_lwps, unsuspend_and_proceed_one_lwp, except);
3978 find_inferior (&all_lwps, proceed_one_lwp, except);
3982 #ifdef HAVE_LINUX_REGSETS
3984 #define use_linux_regsets 1
3987 regsets_fetch_inferior_registers (struct regcache *regcache)
3989 struct regset_info *regset;
3990 int saw_general_regs = 0;
3994 regset = target_regsets;
3996 pid = lwpid_of (get_thread_lwp (current_inferior));
3997 while (regset->size >= 0)
4002 if (regset->size == 0 || disabled_regsets[regset - target_regsets])
4008 buf = xmalloc (regset->size);
4010 nt_type = regset->nt_type;
4014 iov.iov_len = regset->size;
4015 data = (void *) &iov;
4021 res = ptrace (regset->get_request, pid,
4022 (PTRACE_ARG3_TYPE) (long) nt_type, data);
4024 res = ptrace (regset->get_request, pid, data, nt_type);
4030 /* If we get EIO on a regset, do not try it again for
4032 disabled_regsets[regset - target_regsets] = 1;
4039 sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d",
4044 else if (regset->type == GENERAL_REGS)
4045 saw_general_regs = 1;
4046 regset->store_function (regcache, buf);
4050 if (saw_general_regs)
4057 regsets_store_inferior_registers (struct regcache *regcache)
4059 struct regset_info *regset;
4060 int saw_general_regs = 0;
4064 regset = target_regsets;
4066 pid = lwpid_of (get_thread_lwp (current_inferior));
4067 while (regset->size >= 0)
4072 if (regset->size == 0 || disabled_regsets[regset - target_regsets])
4078 buf = xmalloc (regset->size);
4080 /* First fill the buffer with the current register set contents,
4081 in case there are any items in the kernel's regset that are
4082 not in gdbserver's regcache. */
4084 nt_type = regset->nt_type;
4088 iov.iov_len = regset->size;
4089 data = (void *) &iov;
4095 res = ptrace (regset->get_request, pid,
4096 (PTRACE_ARG3_TYPE) (long) nt_type, data);
4098 res = ptrace (regset->get_request, pid, data, nt_type);
4103 /* Then overlay our cached registers on that. */
4104 regset->fill_function (regcache, buf);
4106 /* Only now do we write the register set. */
4108 res = ptrace (regset->set_request, pid,
4109 (PTRACE_ARG3_TYPE) (long) nt_type, data);
4111 res = ptrace (regset->set_request, pid, data, nt_type);
4119 /* If we get EIO on a regset, do not try it again for
4121 disabled_regsets[regset - target_regsets] = 1;
4125 else if (errno == ESRCH)
4127 /* At this point, ESRCH should mean the process is
4128 already gone, in which case we simply ignore attempts
4129 to change its registers. See also the related
4130 comment in linux_resume_one_lwp. */
4136 perror ("Warning: ptrace(regsets_store_inferior_registers)");
4139 else if (regset->type == GENERAL_REGS)
4140 saw_general_regs = 1;
4144 if (saw_general_regs)
4150 #else /* !HAVE_LINUX_REGSETS */
4152 #define use_linux_regsets 0
4153 #define regsets_fetch_inferior_registers(regcache) 1
4154 #define regsets_store_inferior_registers(regcache) 1
4158 /* Return 1 if register REGNO is supported by one of the regset ptrace
4159 calls or 0 if it has to be transferred individually. */
4162 linux_register_in_regsets (int regno)
4164 unsigned char mask = 1 << (regno % 8);
4165 size_t index = regno / 8;
4167 return (use_linux_regsets
4168 && (the_low_target.regset_bitmap == NULL
4169 || (the_low_target.regset_bitmap[index] & mask) != 0));
4172 #ifdef HAVE_LINUX_USRREGS
4175 register_addr (int regnum)
4179 if (regnum < 0 || regnum >= the_low_target.num_regs)
4180 error ("Invalid register number %d.", regnum);
4182 addr = the_low_target.regmap[regnum];
4187 /* Fetch one register. */
4189 fetch_register (struct regcache *regcache, int regno)
4196 if (regno >= the_low_target.num_regs)
4198 if ((*the_low_target.cannot_fetch_register) (regno))
4201 regaddr = register_addr (regno);
4205 size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
4206 & -sizeof (PTRACE_XFER_TYPE));
4207 buf = alloca (size);
4209 pid = lwpid_of (get_thread_lwp (current_inferior));
4210 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
4213 *(PTRACE_XFER_TYPE *) (buf + i) =
4214 ptrace (PTRACE_PEEKUSER, pid,
4215 /* Coerce to a uintptr_t first to avoid potential gcc warning
4216 of coercing an 8 byte integer to a 4 byte pointer. */
4217 (PTRACE_ARG3_TYPE) (uintptr_t) regaddr, 0);
4218 regaddr += sizeof (PTRACE_XFER_TYPE);
4220 error ("reading register %d: %s", regno, strerror (errno));
4223 if (the_low_target.supply_ptrace_register)
4224 the_low_target.supply_ptrace_register (regcache, regno, buf);
4226 supply_register (regcache, regno, buf);
4229 /* Store one register. */
4231 store_register (struct regcache *regcache, int regno)
4238 if (regno >= the_low_target.num_regs)
4240 if ((*the_low_target.cannot_store_register) (regno))
4243 regaddr = register_addr (regno);
4247 size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
4248 & -sizeof (PTRACE_XFER_TYPE));
4249 buf = alloca (size);
4250 memset (buf, 0, size);
4252 if (the_low_target.collect_ptrace_register)
4253 the_low_target.collect_ptrace_register (regcache, regno, buf);
4255 collect_register (regcache, regno, buf);
4257 pid = lwpid_of (get_thread_lwp (current_inferior));
4258 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
4261 ptrace (PTRACE_POKEUSER, pid,
4262 /* Coerce to a uintptr_t first to avoid potential gcc warning
4263 about coercing an 8 byte integer to a 4 byte pointer. */
4264 (PTRACE_ARG3_TYPE) (uintptr_t) regaddr,
4265 (PTRACE_ARG4_TYPE) *(PTRACE_XFER_TYPE *) (buf + i));
4268 /* At this point, ESRCH should mean the process is
4269 already gone, in which case we simply ignore attempts
4270 to change its registers. See also the related
4271 comment in linux_resume_one_lwp. */
4275 if ((*the_low_target.cannot_store_register) (regno) == 0)
4276 error ("writing register %d: %s", regno, strerror (errno));
4278 regaddr += sizeof (PTRACE_XFER_TYPE);
4282 /* Fetch all registers, or just one, from the child process.
4283 If REGNO is -1, do this for all registers, skipping any that are
4284 assumed to have been retrieved by regsets_fetch_inferior_registers,
4285 unless ALL is non-zero.
4286 Otherwise, REGNO specifies which register (so we can save time). */
4288 usr_fetch_inferior_registers (struct regcache *regcache, int regno, int all)
4292 for (regno = 0; regno < the_low_target.num_regs; regno++)
4293 if (all || !linux_register_in_regsets (regno))
4294 fetch_register (regcache, regno);
4297 fetch_register (regcache, regno);
4300 /* Store our register values back into the inferior.
4301 If REGNO is -1, do this for all registers, skipping any that are
4302 assumed to have been saved by regsets_store_inferior_registers,
4303 unless ALL is non-zero.
4304 Otherwise, REGNO specifies which register (so we can save time). */
4306 usr_store_inferior_registers (struct regcache *regcache, int regno, int all)
4310 for (regno = 0; regno < the_low_target.num_regs; regno++)
4311 if (all || !linux_register_in_regsets (regno))
4312 store_register (regcache, regno);
4315 store_register (regcache, regno);
4318 #else /* !HAVE_LINUX_USRREGS */
4320 #define usr_fetch_inferior_registers(regcache, regno, all) do {} while (0)
4321 #define usr_store_inferior_registers(regcache, regno, all) do {} while (0)
4327 linux_fetch_registers (struct regcache *regcache, int regno)
4334 if (the_low_target.fetch_register != NULL)
4335 for (regno = 0; regno < the_low_target.num_regs; regno++)
4336 (*the_low_target.fetch_register) (regcache, regno);
4338 all = regsets_fetch_inferior_registers (regcache);
4339 usr_fetch_inferior_registers (regcache, -1, all);
4343 if (the_low_target.fetch_register != NULL
4344 && (*the_low_target.fetch_register) (regcache, regno))
4347 use_regsets = linux_register_in_regsets (regno);
4349 all = regsets_fetch_inferior_registers (regcache);
4350 if (!use_regsets || all)
4351 usr_fetch_inferior_registers (regcache, regno, 1);
4356 linux_store_registers (struct regcache *regcache, int regno)
4363 all = regsets_store_inferior_registers (regcache);
4364 usr_store_inferior_registers (regcache, regno, all);
4368 use_regsets = linux_register_in_regsets (regno);
4370 all = regsets_store_inferior_registers (regcache);
4371 if (!use_regsets || all)
4372 usr_store_inferior_registers (regcache, regno, 1);
4377 /* Copy LEN bytes from inferior's memory starting at MEMADDR
4378 to debugger memory starting at MYADDR. */
4381 linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
4383 int pid = lwpid_of (get_thread_lwp (current_inferior));
4384 register PTRACE_XFER_TYPE *buffer;
4385 register CORE_ADDR addr;
4392 /* Try using /proc. Don't bother for one word. */
4393 if (len >= 3 * sizeof (long))
4397 /* We could keep this file open and cache it - possibly one per
4398 thread. That requires some juggling, but is even faster. */
4399 sprintf (filename, "/proc/%d/mem", pid);
4400 fd = open (filename, O_RDONLY | O_LARGEFILE);
4404 /* If pread64 is available, use it. It's faster if the kernel
4405 supports it (only one syscall), and it's 64-bit safe even on
4406 32-bit platforms (for instance, SPARC debugging a SPARC64
4409 bytes = pread64 (fd, myaddr, len, memaddr);
4412 if (lseek (fd, memaddr, SEEK_SET) != -1)
4413 bytes = read (fd, myaddr, len);
4420 /* Some data was read, we'll try to get the rest with ptrace. */
4430 /* Round starting address down to longword boundary. */
4431 addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
4432 /* Round ending address up; get number of longwords that makes. */
4433 count = ((((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
4434 / sizeof (PTRACE_XFER_TYPE));
4435 /* Allocate buffer of that many longwords. */
4436 buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
4438 /* Read all the longwords */
4440 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
4442 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
4443 about coercing an 8 byte integer to a 4 byte pointer. */
4444 buffer[i] = ptrace (PTRACE_PEEKTEXT, pid,
4445 (PTRACE_ARG3_TYPE) (uintptr_t) addr, 0);
4451 /* Copy appropriate bytes out of the buffer. */
4454 i *= sizeof (PTRACE_XFER_TYPE);
4455 i -= memaddr & (sizeof (PTRACE_XFER_TYPE) - 1);
4457 (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
4464 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
4465 memory at MEMADDR. On failure (cannot write to the inferior)
4466 returns the value of errno. */
4469 linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
4472 /* Round starting address down to longword boundary. */
4473 register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
4474 /* Round ending address up; get number of longwords that makes. */
4476 = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
4477 / sizeof (PTRACE_XFER_TYPE);
4479 /* Allocate buffer of that many longwords. */
4480 register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *)
4481 alloca (count * sizeof (PTRACE_XFER_TYPE));
4483 int pid = lwpid_of (get_thread_lwp (current_inferior));
4487 /* Dump up to four bytes. */
4488 unsigned int val = * (unsigned int *) myaddr;
4494 val = val & 0xffffff;
4495 fprintf (stderr, "Writing %0*x to 0x%08lx\n", 2 * ((len < 4) ? len : 4),
4496 val, (long)memaddr);
4499 /* Fill start and end extra bytes of buffer with existing memory data. */
4502 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
4503 about coercing an 8 byte integer to a 4 byte pointer. */
4504 buffer[0] = ptrace (PTRACE_PEEKTEXT, pid,
4505 (PTRACE_ARG3_TYPE) (uintptr_t) addr, 0);
4513 = ptrace (PTRACE_PEEKTEXT, pid,
4514 /* Coerce to a uintptr_t first to avoid potential gcc warning
4515 about coercing an 8 byte integer to a 4 byte pointer. */
4516 (PTRACE_ARG3_TYPE) (uintptr_t) (addr + (count - 1)
4517 * sizeof (PTRACE_XFER_TYPE)),
4523 /* Copy data to be written over corresponding part of buffer. */
4525 memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
4528 /* Write the entire buffer. */
4530 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
4533 ptrace (PTRACE_POKETEXT, pid,
4534 /* Coerce to a uintptr_t first to avoid potential gcc warning
4535 about coercing an 8 byte integer to a 4 byte pointer. */
4536 (PTRACE_ARG3_TYPE) (uintptr_t) addr,
4537 (PTRACE_ARG4_TYPE) buffer[i]);
4545 /* Non-zero if the kernel supports PTRACE_O_TRACEFORK. */
4546 static int linux_supports_tracefork_flag;
4549 linux_enable_event_reporting (int pid)
4551 if (!linux_supports_tracefork_flag)
4554 ptrace (PTRACE_SETOPTIONS, pid, 0, (PTRACE_ARG4_TYPE) PTRACE_O_TRACECLONE);
4557 /* Helper functions for linux_test_for_tracefork, called via clone (). */
4560 linux_tracefork_grandchild (void *arg)
4565 #define STACK_SIZE 4096
4568 linux_tracefork_child (void *arg)
4570 ptrace (PTRACE_TRACEME, 0, 0, 0);
4571 kill (getpid (), SIGSTOP);
4573 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
4576 linux_tracefork_grandchild (NULL);
4578 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4581 __clone2 (linux_tracefork_grandchild, arg, STACK_SIZE,
4582 CLONE_VM | SIGCHLD, NULL);
4584 clone (linux_tracefork_grandchild, (char *) arg + STACK_SIZE,
4585 CLONE_VM | SIGCHLD, NULL);
4588 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4593 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
4594 sure that we can enable the option, and that it had the desired
4598 linux_test_for_tracefork (void)
4600 int child_pid, ret, status;
4602 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4603 char *stack = xmalloc (STACK_SIZE * 4);
4604 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4606 linux_supports_tracefork_flag = 0;
4608 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
4610 child_pid = fork ();
4612 linux_tracefork_child (NULL);
4614 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4616 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
4618 child_pid = __clone2 (linux_tracefork_child, stack, STACK_SIZE,
4619 CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
4620 #else /* !__ia64__ */
4621 child_pid = clone (linux_tracefork_child, stack + STACK_SIZE,
4622 CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
4623 #endif /* !__ia64__ */
4625 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4627 if (child_pid == -1)
4628 perror_with_name ("clone");
4630 ret = my_waitpid (child_pid, &status, 0);
4632 perror_with_name ("waitpid");
4633 else if (ret != child_pid)
4634 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret);
4635 if (! WIFSTOPPED (status))
4636 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status);
4638 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0,
4639 (PTRACE_ARG4_TYPE) PTRACE_O_TRACEFORK);
4642 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
4645 warning ("linux_test_for_tracefork: failed to kill child");
4649 ret = my_waitpid (child_pid, &status, 0);
4650 if (ret != child_pid)
4651 warning ("linux_test_for_tracefork: failed to wait for killed child");
4652 else if (!WIFSIGNALED (status))
4653 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
4654 "killed child", status);
4659 ret = ptrace (PTRACE_CONT, child_pid, 0, 0);
4661 warning ("linux_test_for_tracefork: failed to resume child");
4663 ret = my_waitpid (child_pid, &status, 0);
4665 if (ret == child_pid && WIFSTOPPED (status)
4666 && status >> 16 == PTRACE_EVENT_FORK)
4669 ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
4670 if (ret == 0 && second_pid != 0)
4674 linux_supports_tracefork_flag = 1;
4675 my_waitpid (second_pid, &second_status, 0);
4676 ret = ptrace (PTRACE_KILL, second_pid, 0, 0);
4678 warning ("linux_test_for_tracefork: failed to kill second child");
4679 my_waitpid (second_pid, &status, 0);
4683 warning ("linux_test_for_tracefork: unexpected result from waitpid "
4684 "(%d, status 0x%x)", ret, status);
4688 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
4690 warning ("linux_test_for_tracefork: failed to kill child");
4691 my_waitpid (child_pid, &status, 0);
4693 while (WIFSTOPPED (status));
4695 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4697 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4702 linux_look_up_symbols (void)
4704 #ifdef USE_THREAD_DB
4705 struct process_info *proc = current_process ();
4707 if (proc->private->thread_db != NULL)
4710 /* If the kernel supports tracing forks then it also supports tracing
4711 clones, and then we don't need to use the magic thread event breakpoint
4712 to learn about threads. */
4713 thread_db_init (!linux_supports_tracefork_flag);
4718 linux_request_interrupt (void)
4720 extern unsigned long signal_pid;
4722 if (!ptid_equal (cont_thread, null_ptid)
4723 && !ptid_equal (cont_thread, minus_one_ptid))
4725 struct lwp_info *lwp;
4728 lwp = get_thread_lwp (current_inferior);
4729 lwpid = lwpid_of (lwp);
4730 kill_lwp (lwpid, SIGINT);
4733 kill_lwp (signal_pid, SIGINT);
4736 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
4737 to debugger memory starting at MYADDR. */
4740 linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len)
4742 char filename[PATH_MAX];
4744 int pid = lwpid_of (get_thread_lwp (current_inferior));
4746 xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
4748 fd = open (filename, O_RDONLY);
4752 if (offset != (CORE_ADDR) 0
4753 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
4756 n = read (fd, myaddr, len);
4763 /* These breakpoint and watchpoint related wrapper functions simply
4764 pass on the function call if the target has registered a
4765 corresponding function. */
4768 linux_insert_point (char type, CORE_ADDR addr, int len)
4770 if (the_low_target.insert_point != NULL)
4771 return the_low_target.insert_point (type, addr, len);
4773 /* Unsupported (see target.h). */
4778 linux_remove_point (char type, CORE_ADDR addr, int len)
4780 if (the_low_target.remove_point != NULL)
4781 return the_low_target.remove_point (type, addr, len);
4783 /* Unsupported (see target.h). */
4788 linux_stopped_by_watchpoint (void)
4790 struct lwp_info *lwp = get_thread_lwp (current_inferior);
4792 return lwp->stopped_by_watchpoint;
4796 linux_stopped_data_address (void)
4798 struct lwp_info *lwp = get_thread_lwp (current_inferior);
4800 return lwp->stopped_data_address;
4803 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4804 #if ! (defined(PT_TEXT_ADDR) \
4805 || defined(PT_DATA_ADDR) \
4806 || defined(PT_TEXT_END_ADDR))
4807 #if defined(__mcoldfire__)
4808 /* These should really be defined in the kernel's ptrace.h header. */
4809 #define PT_TEXT_ADDR 49*4
4810 #define PT_DATA_ADDR 50*4
4811 #define PT_TEXT_END_ADDR 51*4
4813 #define PT_TEXT_ADDR 220
4814 #define PT_TEXT_END_ADDR 224
4815 #define PT_DATA_ADDR 228
4816 #elif defined(__TMS320C6X__)
4817 #define PT_TEXT_ADDR (0x10000*4)
4818 #define PT_DATA_ADDR (0x10004*4)
4819 #define PT_TEXT_END_ADDR (0x10008*4)
4823 /* Under uClinux, programs are loaded at non-zero offsets, which we need
4824 to tell gdb about. */
4827 linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p)
4829 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
4830 unsigned long text, text_end, data;
4831 int pid = lwpid_of (get_thread_lwp (current_inferior));
4835 text = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_ADDR, 0);
4836 text_end = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_END_ADDR, 0);
4837 data = ptrace (PTRACE_PEEKUSER, pid, (long)PT_DATA_ADDR, 0);
4841 /* Both text and data offsets produced at compile-time (and so
4842 used by gdb) are relative to the beginning of the program,
4843 with the data segment immediately following the text segment.
4844 However, the actual runtime layout in memory may put the data
4845 somewhere else, so when we send gdb a data base-address, we
4846 use the real data base address and subtract the compile-time
4847 data base-address from it (which is just the length of the
4848 text segment). BSS immediately follows data in both
4851 *data_p = data - (text_end - text);
4861 linux_qxfer_osdata (const char *annex,
4862 unsigned char *readbuf, unsigned const char *writebuf,
4863 CORE_ADDR offset, int len)
4865 return linux_common_xfer_osdata (annex, readbuf, offset, len);
4868 /* Convert a native/host siginfo object, into/from the siginfo in the
4869 layout of the inferiors' architecture. */
4872 siginfo_fixup (siginfo_t *siginfo, void *inf_siginfo, int direction)
4876 if (the_low_target.siginfo_fixup != NULL)
4877 done = the_low_target.siginfo_fixup (siginfo, inf_siginfo, direction);
4879 /* If there was no callback, or the callback didn't do anything,
4880 then just do a straight memcpy. */
4884 memcpy (siginfo, inf_siginfo, sizeof (siginfo_t));
4886 memcpy (inf_siginfo, siginfo, sizeof (siginfo_t));
4891 linux_xfer_siginfo (const char *annex, unsigned char *readbuf,
4892 unsigned const char *writebuf, CORE_ADDR offset, int len)
4896 char inf_siginfo[sizeof (siginfo_t)];
4898 if (current_inferior == NULL)
4901 pid = lwpid_of (get_thread_lwp (current_inferior));
4904 fprintf (stderr, "%s siginfo for lwp %d.\n",
4905 readbuf != NULL ? "Reading" : "Writing",
4908 if (offset >= sizeof (siginfo))
4911 if (ptrace (PTRACE_GETSIGINFO, pid, 0, &siginfo) != 0)
4914 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
4915 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
4916 inferior with a 64-bit GDBSERVER should look the same as debugging it
4917 with a 32-bit GDBSERVER, we need to convert it. */
4918 siginfo_fixup (&siginfo, inf_siginfo, 0);
4920 if (offset + len > sizeof (siginfo))
4921 len = sizeof (siginfo) - offset;
4923 if (readbuf != NULL)
4924 memcpy (readbuf, inf_siginfo + offset, len);
4927 memcpy (inf_siginfo + offset, writebuf, len);
4929 /* Convert back to ptrace layout before flushing it out. */
4930 siginfo_fixup (&siginfo, inf_siginfo, 1);
4932 if (ptrace (PTRACE_SETSIGINFO, pid, 0, &siginfo) != 0)
4939 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4940 so we notice when children change state; as the handler for the
4941 sigsuspend in my_waitpid. */
4944 sigchld_handler (int signo)
4946 int old_errno = errno;
4952 /* fprintf is not async-signal-safe, so call write
4954 if (write (2, "sigchld_handler\n",
4955 sizeof ("sigchld_handler\n") - 1) < 0)
4956 break; /* just ignore */
4960 if (target_is_async_p ())
4961 async_file_mark (); /* trigger a linux_wait */
4967 linux_supports_non_stop (void)
4973 linux_async (int enable)
4975 int previous = (linux_event_pipe[0] != -1);
4978 fprintf (stderr, "linux_async (%d), previous=%d\n",
4981 if (previous != enable)
4984 sigemptyset (&mask);
4985 sigaddset (&mask, SIGCHLD);
4987 sigprocmask (SIG_BLOCK, &mask, NULL);
4991 if (pipe (linux_event_pipe) == -1)
4992 fatal ("creating event pipe failed.");
4994 fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK);
4995 fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK);
4997 /* Register the event loop handler. */
4998 add_file_handler (linux_event_pipe[0],
4999 handle_target_event, NULL);
5001 /* Always trigger a linux_wait. */
5006 delete_file_handler (linux_event_pipe[0]);
5008 close (linux_event_pipe[0]);
5009 close (linux_event_pipe[1]);
5010 linux_event_pipe[0] = -1;
5011 linux_event_pipe[1] = -1;
5014 sigprocmask (SIG_UNBLOCK, &mask, NULL);
5021 linux_start_non_stop (int nonstop)
5023 /* Register or unregister from event-loop accordingly. */
5024 linux_async (nonstop);
5029 linux_supports_multi_process (void)
5035 linux_supports_disable_randomization (void)
5037 #ifdef HAVE_PERSONALITY
5045 linux_supports_agent (void)
5050 /* Enumerate spufs IDs for process PID. */
5052 spu_enumerate_spu_ids (long pid, unsigned char *buf, CORE_ADDR offset, int len)
5058 struct dirent *entry;
5060 sprintf (path, "/proc/%ld/fd", pid);
5061 dir = opendir (path);
5066 while ((entry = readdir (dir)) != NULL)
5072 fd = atoi (entry->d_name);
5076 sprintf (path, "/proc/%ld/fd/%d", pid, fd);
5077 if (stat (path, &st) != 0)
5079 if (!S_ISDIR (st.st_mode))
5082 if (statfs (path, &stfs) != 0)
5084 if (stfs.f_type != SPUFS_MAGIC)
5087 if (pos >= offset && pos + 4 <= offset + len)
5089 *(unsigned int *)(buf + pos - offset) = fd;
5099 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
5100 object type, using the /proc file system. */
5102 linux_qxfer_spu (const char *annex, unsigned char *readbuf,
5103 unsigned const char *writebuf,
5104 CORE_ADDR offset, int len)
5106 long pid = lwpid_of (get_thread_lwp (current_inferior));
5111 if (!writebuf && !readbuf)
5119 return spu_enumerate_spu_ids (pid, readbuf, offset, len);
5122 sprintf (buf, "/proc/%ld/fd/%s", pid, annex);
5123 fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
5128 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
5135 ret = write (fd, writebuf, (size_t) len);
5137 ret = read (fd, readbuf, (size_t) len);
5143 #if defined PT_GETDSBT || defined PTRACE_GETFDPIC
5144 struct target_loadseg
5146 /* Core address to which the segment is mapped. */
5148 /* VMA recorded in the program header. */
5150 /* Size of this segment in memory. */
5154 # if defined PT_GETDSBT
5155 struct target_loadmap
5157 /* Protocol version number, must be zero. */
5159 /* Pointer to the DSBT table, its size, and the DSBT index. */
5160 unsigned *dsbt_table;
5161 unsigned dsbt_size, dsbt_index;
5162 /* Number of segments in this map. */
5164 /* The actual memory map. */
5165 struct target_loadseg segs[/*nsegs*/];
5167 # define LINUX_LOADMAP PT_GETDSBT
5168 # define LINUX_LOADMAP_EXEC PTRACE_GETDSBT_EXEC
5169 # define LINUX_LOADMAP_INTERP PTRACE_GETDSBT_INTERP
5171 struct target_loadmap
5173 /* Protocol version number, must be zero. */
5175 /* Number of segments in this map. */
5177 /* The actual memory map. */
5178 struct target_loadseg segs[/*nsegs*/];
5180 # define LINUX_LOADMAP PTRACE_GETFDPIC
5181 # define LINUX_LOADMAP_EXEC PTRACE_GETFDPIC_EXEC
5182 # define LINUX_LOADMAP_INTERP PTRACE_GETFDPIC_INTERP
5186 linux_read_loadmap (const char *annex, CORE_ADDR offset,
5187 unsigned char *myaddr, unsigned int len)
5189 int pid = lwpid_of (get_thread_lwp (current_inferior));
5191 struct target_loadmap *data = NULL;
5192 unsigned int actual_length, copy_length;
5194 if (strcmp (annex, "exec") == 0)
5195 addr = (int) LINUX_LOADMAP_EXEC;
5196 else if (strcmp (annex, "interp") == 0)
5197 addr = (int) LINUX_LOADMAP_INTERP;
5201 if (ptrace (LINUX_LOADMAP, pid, addr, &data) != 0)
5207 actual_length = sizeof (struct target_loadmap)
5208 + sizeof (struct target_loadseg) * data->nsegs;
5210 if (offset < 0 || offset > actual_length)
5213 copy_length = actual_length - offset < len ? actual_length - offset : len;
5214 memcpy (myaddr, (char *) data + offset, copy_length);
5218 # define linux_read_loadmap NULL
5219 #endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */
5222 linux_process_qsupported (const char *query)
5224 if (the_low_target.process_qsupported != NULL)
5225 the_low_target.process_qsupported (query);
5229 linux_supports_tracepoints (void)
5231 if (*the_low_target.supports_tracepoints == NULL)
5234 return (*the_low_target.supports_tracepoints) ();
5238 linux_read_pc (struct regcache *regcache)
5240 if (the_low_target.get_pc == NULL)
5243 return (*the_low_target.get_pc) (regcache);
5247 linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
5249 gdb_assert (the_low_target.set_pc != NULL);
5251 (*the_low_target.set_pc) (regcache, pc);
5255 linux_thread_stopped (struct thread_info *thread)
5257 return get_thread_lwp (thread)->stopped;
5260 /* This exposes stop-all-threads functionality to other modules. */
5263 linux_pause_all (int freeze)
5265 stop_all_lwps (freeze, NULL);
5268 /* This exposes unstop-all-threads functionality to other gdbserver
5272 linux_unpause_all (int unfreeze)
5274 unstop_all_lwps (unfreeze, NULL);
5278 linux_prepare_to_access_memory (void)
5280 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
5283 linux_pause_all (1);
5288 linux_done_accessing_memory (void)
5290 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
5293 linux_unpause_all (1);
5297 linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr,
5298 CORE_ADDR collector,
5301 CORE_ADDR *jump_entry,
5302 CORE_ADDR *trampoline,
5303 ULONGEST *trampoline_size,
5304 unsigned char *jjump_pad_insn,
5305 ULONGEST *jjump_pad_insn_size,
5306 CORE_ADDR *adjusted_insn_addr,
5307 CORE_ADDR *adjusted_insn_addr_end,
5310 return (*the_low_target.install_fast_tracepoint_jump_pad)
5311 (tpoint, tpaddr, collector, lockaddr, orig_size,
5312 jump_entry, trampoline, trampoline_size,
5313 jjump_pad_insn, jjump_pad_insn_size,
5314 adjusted_insn_addr, adjusted_insn_addr_end,
5318 static struct emit_ops *
5319 linux_emit_ops (void)
5321 if (the_low_target.emit_ops != NULL)
5322 return (*the_low_target.emit_ops) ();
5328 linux_get_min_fast_tracepoint_insn_len (void)
5330 return (*the_low_target.get_min_fast_tracepoint_insn_len) ();
5333 /* Extract &phdr and num_phdr in the inferior. Return 0 on success. */
5336 get_phdr_phnum_from_proc_auxv (const int pid, const int is_elf64,
5337 CORE_ADDR *phdr_memaddr, int *num_phdr)
5339 char filename[PATH_MAX];
5341 const int auxv_size = is_elf64
5342 ? sizeof (Elf64_auxv_t) : sizeof (Elf32_auxv_t);
5343 char buf[sizeof (Elf64_auxv_t)]; /* The larger of the two. */
5345 xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
5347 fd = open (filename, O_RDONLY);
5353 while (read (fd, buf, auxv_size) == auxv_size
5354 && (*phdr_memaddr == 0 || *num_phdr == 0))
5358 Elf64_auxv_t *const aux = (Elf64_auxv_t *) buf;
5360 switch (aux->a_type)
5363 *phdr_memaddr = aux->a_un.a_val;
5366 *num_phdr = aux->a_un.a_val;
5372 Elf32_auxv_t *const aux = (Elf32_auxv_t *) buf;
5374 switch (aux->a_type)
5377 *phdr_memaddr = aux->a_un.a_val;
5380 *num_phdr = aux->a_un.a_val;
5388 if (*phdr_memaddr == 0 || *num_phdr == 0)
5390 warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: "
5391 "phdr_memaddr = %ld, phdr_num = %d",
5392 (long) *phdr_memaddr, *num_phdr);
5399 /* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */
5402 get_dynamic (const int pid, const int is_elf64)
5404 CORE_ADDR phdr_memaddr, relocation;
5406 unsigned char *phdr_buf;
5407 const int phdr_size = is_elf64 ? sizeof (Elf64_Phdr) : sizeof (Elf32_Phdr);
5409 if (get_phdr_phnum_from_proc_auxv (pid, is_elf64, &phdr_memaddr, &num_phdr))
5412 gdb_assert (num_phdr < 100); /* Basic sanity check. */
5413 phdr_buf = alloca (num_phdr * phdr_size);
5415 if (linux_read_memory (phdr_memaddr, phdr_buf, num_phdr * phdr_size))
5418 /* Compute relocation: it is expected to be 0 for "regular" executables,
5419 non-zero for PIE ones. */
5421 for (i = 0; relocation == -1 && i < num_phdr; i++)
5424 Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size);
5426 if (p->p_type == PT_PHDR)
5427 relocation = phdr_memaddr - p->p_vaddr;
5431 Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size);
5433 if (p->p_type == PT_PHDR)
5434 relocation = phdr_memaddr - p->p_vaddr;
5437 if (relocation == -1)
5439 /* PT_PHDR is optional, but necessary for PIE in general. Fortunately
5440 any real world executables, including PIE executables, have always
5441 PT_PHDR present. PT_PHDR is not present in some shared libraries or
5442 in fpc (Free Pascal 2.4) binaries but neither of those have a need for
5443 or present DT_DEBUG anyway (fpc binaries are statically linked).
5445 Therefore if there exists DT_DEBUG there is always also PT_PHDR.
5447 GDB could find RELOCATION also from AT_ENTRY - e_entry. */
5452 for (i = 0; i < num_phdr; i++)
5456 Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size);
5458 if (p->p_type == PT_DYNAMIC)
5459 return p->p_vaddr + relocation;
5463 Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size);
5465 if (p->p_type == PT_DYNAMIC)
5466 return p->p_vaddr + relocation;
5473 /* Return &_r_debug in the inferior, or -1 if not present. Return value
5474 can be 0 if the inferior does not yet have the library list initialized.
5475 We look for DT_MIPS_RLD_MAP first. MIPS executables use this instead of
5476 DT_DEBUG, although they sometimes contain an unused DT_DEBUG entry too. */
5479 get_r_debug (const int pid, const int is_elf64)
5481 CORE_ADDR dynamic_memaddr;
5482 const int dyn_size = is_elf64 ? sizeof (Elf64_Dyn) : sizeof (Elf32_Dyn);
5483 unsigned char buf[sizeof (Elf64_Dyn)]; /* The larger of the two. */
5486 dynamic_memaddr = get_dynamic (pid, is_elf64);
5487 if (dynamic_memaddr == 0)
5490 while (linux_read_memory (dynamic_memaddr, buf, dyn_size) == 0)
5494 Elf64_Dyn *const dyn = (Elf64_Dyn *) buf;
5498 unsigned char buf[sizeof (Elf64_Xword)];
5502 if (dyn->d_tag == DT_MIPS_RLD_MAP)
5504 if (linux_read_memory (dyn->d_un.d_val,
5505 rld_map.buf, sizeof (rld_map.buf)) == 0)
5511 if (dyn->d_tag == DT_DEBUG && map == -1)
5512 map = dyn->d_un.d_val;
5514 if (dyn->d_tag == DT_NULL)
5519 Elf32_Dyn *const dyn = (Elf32_Dyn *) buf;
5523 unsigned char buf[sizeof (Elf32_Word)];
5527 if (dyn->d_tag == DT_MIPS_RLD_MAP)
5529 if (linux_read_memory (dyn->d_un.d_val,
5530 rld_map.buf, sizeof (rld_map.buf)) == 0)
5536 if (dyn->d_tag == DT_DEBUG && map == -1)
5537 map = dyn->d_un.d_val;
5539 if (dyn->d_tag == DT_NULL)
5543 dynamic_memaddr += dyn_size;
5549 /* Read one pointer from MEMADDR in the inferior. */
5552 read_one_ptr (CORE_ADDR memaddr, CORE_ADDR *ptr, int ptr_size)
5556 /* Go through a union so this works on either big or little endian
5557 hosts, when the inferior's pointer size is smaller than the size
5558 of CORE_ADDR. It is assumed the inferior's endianness is the
5559 same of the superior's. */
5562 CORE_ADDR core_addr;
5567 ret = linux_read_memory (memaddr, &addr.uc, ptr_size);
5570 if (ptr_size == sizeof (CORE_ADDR))
5571 *ptr = addr.core_addr;
5572 else if (ptr_size == sizeof (unsigned int))
5575 gdb_assert_not_reached ("unhandled pointer size");
5580 struct link_map_offsets
5582 /* Offset and size of r_debug.r_version. */
5583 int r_version_offset;
5585 /* Offset and size of r_debug.r_map. */
5588 /* Offset to l_addr field in struct link_map. */
5591 /* Offset to l_name field in struct link_map. */
5594 /* Offset to l_ld field in struct link_map. */
5597 /* Offset to l_next field in struct link_map. */
5600 /* Offset to l_prev field in struct link_map. */
5604 /* Construct qXfer:libraries-svr4:read reply. */
5607 linux_qxfer_libraries_svr4 (const char *annex, unsigned char *readbuf,
5608 unsigned const char *writebuf,
5609 CORE_ADDR offset, int len)
5612 unsigned document_len;
5613 struct process_info_private *const priv = current_process ()->private;
5614 char filename[PATH_MAX];
5617 static const struct link_map_offsets lmo_32bit_offsets =
5619 0, /* r_version offset. */
5620 4, /* r_debug.r_map offset. */
5621 0, /* l_addr offset in link_map. */
5622 4, /* l_name offset in link_map. */
5623 8, /* l_ld offset in link_map. */
5624 12, /* l_next offset in link_map. */
5625 16 /* l_prev offset in link_map. */
5628 static const struct link_map_offsets lmo_64bit_offsets =
5630 0, /* r_version offset. */
5631 8, /* r_debug.r_map offset. */
5632 0, /* l_addr offset in link_map. */
5633 8, /* l_name offset in link_map. */
5634 16, /* l_ld offset in link_map. */
5635 24, /* l_next offset in link_map. */
5636 32 /* l_prev offset in link_map. */
5638 const struct link_map_offsets *lmo;
5639 unsigned int machine;
5641 if (writebuf != NULL)
5643 if (readbuf == NULL)
5646 pid = lwpid_of (get_thread_lwp (current_inferior));
5647 xsnprintf (filename, sizeof filename, "/proc/%d/exe", pid);
5648 is_elf64 = elf_64_file_p (filename, &machine);
5649 lmo = is_elf64 ? &lmo_64bit_offsets : &lmo_32bit_offsets;
5651 if (priv->r_debug == 0)
5652 priv->r_debug = get_r_debug (pid, is_elf64);
5654 if (priv->r_debug == (CORE_ADDR) -1 || priv->r_debug == 0)
5656 document = xstrdup ("<library-list-svr4 version=\"1.0\"/>\n");
5660 int allocated = 1024;
5662 const int ptr_size = is_elf64 ? 8 : 4;
5663 CORE_ADDR lm_addr, lm_prev, l_name, l_addr, l_ld, l_next, l_prev;
5664 int r_version, header_done = 0;
5666 document = xmalloc (allocated);
5667 strcpy (document, "<library-list-svr4 version=\"1.0\"");
5668 p = document + strlen (document);
5671 if (linux_read_memory (priv->r_debug + lmo->r_version_offset,
5672 (unsigned char *) &r_version,
5673 sizeof (r_version)) != 0
5676 warning ("unexpected r_debug version %d", r_version);
5680 if (read_one_ptr (priv->r_debug + lmo->r_map_offset,
5681 &lm_addr, ptr_size) != 0)
5683 warning ("unable to read r_map from 0x%lx",
5684 (long) priv->r_debug + lmo->r_map_offset);
5689 while (read_one_ptr (lm_addr + lmo->l_name_offset,
5690 &l_name, ptr_size) == 0
5691 && read_one_ptr (lm_addr + lmo->l_addr_offset,
5692 &l_addr, ptr_size) == 0
5693 && read_one_ptr (lm_addr + lmo->l_ld_offset,
5694 &l_ld, ptr_size) == 0
5695 && read_one_ptr (lm_addr + lmo->l_prev_offset,
5696 &l_prev, ptr_size) == 0
5697 && read_one_ptr (lm_addr + lmo->l_next_offset,
5698 &l_next, ptr_size) == 0)
5700 unsigned char libname[PATH_MAX];
5702 if (lm_prev != l_prev)
5704 warning ("Corrupted shared library list: 0x%lx != 0x%lx",
5705 (long) lm_prev, (long) l_prev);
5709 /* Not checking for error because reading may stop before
5710 we've got PATH_MAX worth of characters. */
5712 linux_read_memory (l_name, libname, sizeof (libname) - 1);
5713 libname[sizeof (libname) - 1] = '\0';
5714 if (libname[0] != '\0')
5716 /* 6x the size for xml_escape_text below. */
5717 size_t len = 6 * strlen ((char *) libname);
5722 /* Terminate `<library-list-svr4'. */
5727 while (allocated < p - document + len + 200)
5729 /* Expand to guarantee sufficient storage. */
5730 uintptr_t document_len = p - document;
5732 document = xrealloc (document, 2 * allocated);
5734 p = document + document_len;
5737 name = xml_escape_text ((char *) libname);
5738 p += sprintf (p, "<library name=\"%s\" lm=\"0x%lx\" "
5739 "l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>",
5740 name, (unsigned long) lm_addr,
5741 (unsigned long) l_addr, (unsigned long) l_ld);
5744 else if (lm_prev == 0)
5746 sprintf (p, " main-lm=\"0x%lx\"", (unsigned long) lm_addr);
5759 /* Empty list; terminate `<library-list-svr4'. */
5763 strcpy (p, "</library-list-svr4>");
5766 document_len = strlen (document);
5767 if (offset < document_len)
5768 document_len -= offset;
5771 if (len > document_len)
5774 memcpy (readbuf, document + offset, len);
5780 static struct target_ops linux_target_ops = {
5781 linux_create_inferior,
5790 linux_fetch_registers,
5791 linux_store_registers,
5792 linux_prepare_to_access_memory,
5793 linux_done_accessing_memory,
5796 linux_look_up_symbols,
5797 linux_request_interrupt,
5801 linux_stopped_by_watchpoint,
5802 linux_stopped_data_address,
5803 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
5808 #ifdef USE_THREAD_DB
5809 thread_db_get_tls_address,
5814 hostio_last_error_from_errno,
5817 linux_supports_non_stop,
5819 linux_start_non_stop,
5820 linux_supports_multi_process,
5821 #ifdef USE_THREAD_DB
5822 thread_db_handle_monitor_command,
5826 linux_common_core_of_thread,
5828 linux_process_qsupported,
5829 linux_supports_tracepoints,
5832 linux_thread_stopped,
5836 linux_cancel_breakpoints,
5837 linux_stabilize_threads,
5838 linux_install_fast_tracepoint_jump_pad,
5840 linux_supports_disable_randomization,
5841 linux_get_min_fast_tracepoint_insn_len,
5842 linux_qxfer_libraries_svr4,
5843 linux_supports_agent,
5847 linux_init_signals ()
5849 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
5850 to find what the cancel signal actually is. */
5851 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
5852 signal (__SIGRTMIN+1, SIG_IGN);
5857 initialize_low (void)
5859 struct sigaction sigchld_action;
5860 memset (&sigchld_action, 0, sizeof (sigchld_action));
5861 set_target_ops (&linux_target_ops);
5862 set_breakpoint_data (the_low_target.breakpoint,
5863 the_low_target.breakpoint_len);
5864 linux_init_signals ();
5865 linux_test_for_tracefork ();
5866 #ifdef HAVE_LINUX_REGSETS
5867 for (num_regsets = 0; target_regsets[num_regsets].size >= 0; num_regsets++)
5869 disabled_regsets = xmalloc (num_regsets);
5872 sigchld_action.sa_handler = sigchld_handler;
5873 sigemptyset (&sigchld_action.sa_mask);
5874 sigchld_action.sa_flags = SA_RESTART;
5875 sigaction (SIGCHLD, &sigchld_action, NULL);