5202 lines
138 KiB
C
5202 lines
138 KiB
C
/* Low level interface to ptrace, for the remote server for GDB.
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Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
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2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "server.h"
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#include "linux-low.h"
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#include <sys/wait.h>
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#include <stdio.h>
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#include <sys/param.h>
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#include <sys/ptrace.h>
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#include <signal.h>
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#include <sys/ioctl.h>
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#include <fcntl.h>
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#include <string.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <errno.h>
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#include <sys/syscall.h>
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#include <sched.h>
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#include <ctype.h>
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#include <pwd.h>
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#include <sys/types.h>
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#include <dirent.h>
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#include <sys/stat.h>
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#include <sys/vfs.h>
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#include <sys/uio.h>
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#ifndef ELFMAG0
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/* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h
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then ELFMAG0 will have been defined. If it didn't get included by
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gdb_proc_service.h then including it will likely introduce a duplicate
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definition of elf_fpregset_t. */
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#include <elf.h>
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#endif
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#ifndef SPUFS_MAGIC
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#define SPUFS_MAGIC 0x23c9b64e
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#endif
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#ifndef PTRACE_GETSIGINFO
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# define PTRACE_GETSIGINFO 0x4202
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# define PTRACE_SETSIGINFO 0x4203
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#endif
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#ifndef O_LARGEFILE
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#define O_LARGEFILE 0
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#endif
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/* If the system headers did not provide the constants, hard-code the normal
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values. */
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#ifndef PTRACE_EVENT_FORK
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#define PTRACE_SETOPTIONS 0x4200
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#define PTRACE_GETEVENTMSG 0x4201
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/* options set using PTRACE_SETOPTIONS */
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#define PTRACE_O_TRACESYSGOOD 0x00000001
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#define PTRACE_O_TRACEFORK 0x00000002
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#define PTRACE_O_TRACEVFORK 0x00000004
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#define PTRACE_O_TRACECLONE 0x00000008
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#define PTRACE_O_TRACEEXEC 0x00000010
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#define PTRACE_O_TRACEVFORKDONE 0x00000020
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#define PTRACE_O_TRACEEXIT 0x00000040
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/* Wait extended result codes for the above trace options. */
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#define PTRACE_EVENT_FORK 1
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#define PTRACE_EVENT_VFORK 2
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#define PTRACE_EVENT_CLONE 3
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#define PTRACE_EVENT_EXEC 4
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#define PTRACE_EVENT_VFORK_DONE 5
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#define PTRACE_EVENT_EXIT 6
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#endif /* PTRACE_EVENT_FORK */
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/* We can't always assume that this flag is available, but all systems
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with the ptrace event handlers also have __WALL, so it's safe to use
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in some contexts. */
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#ifndef __WALL
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#define __WALL 0x40000000 /* Wait for any child. */
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#endif
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#ifndef W_STOPCODE
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#define W_STOPCODE(sig) ((sig) << 8 | 0x7f)
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#endif
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/* This is the kernel's hard limit. Not to be confused with
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SIGRTMIN. */
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#ifndef __SIGRTMIN
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#define __SIGRTMIN 32
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#endif
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#ifdef __UCLIBC__
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#if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
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#define HAS_NOMMU
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#endif
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#endif
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/* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
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representation of the thread ID.
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``all_lwps'' is keyed by the process ID - which on Linux is (presently)
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the same as the LWP ID.
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``all_processes'' is keyed by the "overall process ID", which
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GNU/Linux calls tgid, "thread group ID". */
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struct inferior_list all_lwps;
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/* A list of all unknown processes which receive stop signals. Some other
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process will presumably claim each of these as forked children
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momentarily. */
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struct inferior_list stopped_pids;
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/* FIXME this is a bit of a hack, and could be removed. */
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int stopping_threads;
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/* FIXME make into a target method? */
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int using_threads = 1;
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/* True if we're presently stabilizing threads (moving them out of
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jump pads). */
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static int stabilizing_threads;
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/* This flag is true iff we've just created or attached to our first
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inferior but it has not stopped yet. As soon as it does, we need
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to call the low target's arch_setup callback. Doing this only on
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the first inferior avoids reinializing the architecture on every
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inferior, and avoids messing with the register caches of the
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already running inferiors. NOTE: this assumes all inferiors under
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control of gdbserver have the same architecture. */
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static int new_inferior;
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static void linux_resume_one_lwp (struct lwp_info *lwp,
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int step, int signal, siginfo_t *info);
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static void linux_resume (struct thread_resume *resume_info, size_t n);
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static void stop_all_lwps (int suspend, struct lwp_info *except);
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static void unstop_all_lwps (int unsuspend, struct lwp_info *except);
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static int linux_wait_for_event (ptid_t ptid, int *wstat, int options);
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static void *add_lwp (ptid_t ptid);
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static int linux_stopped_by_watchpoint (void);
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static void mark_lwp_dead (struct lwp_info *lwp, int wstat);
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static int linux_core_of_thread (ptid_t ptid);
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static void proceed_all_lwps (void);
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static int finish_step_over (struct lwp_info *lwp);
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static CORE_ADDR get_stop_pc (struct lwp_info *lwp);
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static int kill_lwp (unsigned long lwpid, int signo);
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static void linux_enable_event_reporting (int pid);
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/* True if the low target can hardware single-step. Such targets
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don't need a BREAKPOINT_REINSERT_ADDR callback. */
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static int
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can_hardware_single_step (void)
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{
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return (the_low_target.breakpoint_reinsert_addr == NULL);
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}
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/* True if the low target supports memory breakpoints. If so, we'll
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have a GET_PC implementation. */
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static int
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supports_breakpoints (void)
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{
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return (the_low_target.get_pc != NULL);
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}
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/* Returns true if this target can support fast tracepoints. This
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does not mean that the in-process agent has been loaded in the
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inferior. */
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static int
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supports_fast_tracepoints (void)
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{
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return the_low_target.install_fast_tracepoint_jump_pad != NULL;
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}
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struct pending_signals
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{
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int signal;
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siginfo_t info;
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struct pending_signals *prev;
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};
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#define PTRACE_ARG3_TYPE void *
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#define PTRACE_ARG4_TYPE void *
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#define PTRACE_XFER_TYPE long
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#ifdef HAVE_LINUX_REGSETS
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static char *disabled_regsets;
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static int num_regsets;
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#endif
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/* The read/write ends of the pipe registered as waitable file in the
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event loop. */
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static int linux_event_pipe[2] = { -1, -1 };
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/* True if we're currently in async mode. */
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#define target_is_async_p() (linux_event_pipe[0] != -1)
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static void send_sigstop (struct lwp_info *lwp);
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static void wait_for_sigstop (struct inferior_list_entry *entry);
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/* Accepts an integer PID; Returns a string representing a file that
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can be opened to get info for the child process.
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Space for the result is malloc'd, caller must free. */
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char *
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linux_child_pid_to_exec_file (int pid)
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{
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char *name1, *name2;
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name1 = xmalloc (MAXPATHLEN);
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name2 = xmalloc (MAXPATHLEN);
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memset (name2, 0, MAXPATHLEN);
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sprintf (name1, "/proc/%d/exe", pid);
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if (readlink (name1, name2, MAXPATHLEN) > 0)
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{
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free (name1);
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return name2;
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}
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else
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{
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free (name2);
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return name1;
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}
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}
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/* Return non-zero if HEADER is a 64-bit ELF file. */
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static int
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elf_64_header_p (const Elf64_Ehdr *header)
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{
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return (header->e_ident[EI_MAG0] == ELFMAG0
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&& header->e_ident[EI_MAG1] == ELFMAG1
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&& header->e_ident[EI_MAG2] == ELFMAG2
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&& header->e_ident[EI_MAG3] == ELFMAG3
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&& header->e_ident[EI_CLASS] == ELFCLASS64);
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}
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/* Return non-zero if FILE is a 64-bit ELF file,
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zero if the file is not a 64-bit ELF file,
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and -1 if the file is not accessible or doesn't exist. */
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int
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elf_64_file_p (const char *file)
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{
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Elf64_Ehdr header;
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int fd;
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fd = open (file, O_RDONLY);
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if (fd < 0)
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return -1;
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if (read (fd, &header, sizeof (header)) != sizeof (header))
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{
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close (fd);
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return 0;
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}
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close (fd);
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return elf_64_header_p (&header);
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}
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static void
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delete_lwp (struct lwp_info *lwp)
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{
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remove_thread (get_lwp_thread (lwp));
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remove_inferior (&all_lwps, &lwp->head);
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free (lwp->arch_private);
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free (lwp);
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}
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/* Add a process to the common process list, and set its private
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data. */
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static struct process_info *
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linux_add_process (int pid, int attached)
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{
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struct process_info *proc;
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/* Is this the first process? If so, then set the arch. */
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if (all_processes.head == NULL)
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new_inferior = 1;
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proc = add_process (pid, attached);
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proc->private = xcalloc (1, sizeof (*proc->private));
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if (the_low_target.new_process != NULL)
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proc->private->arch_private = the_low_target.new_process ();
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return proc;
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}
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/* Wrapper function for waitpid which handles EINTR, and emulates
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__WALL for systems where that is not available. */
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static int
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my_waitpid (int pid, int *status, int flags)
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{
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int ret, out_errno;
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if (debug_threads)
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fprintf (stderr, "my_waitpid (%d, 0x%x)\n", pid, flags);
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if (flags & __WALL)
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{
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sigset_t block_mask, org_mask, wake_mask;
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int wnohang;
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wnohang = (flags & WNOHANG) != 0;
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flags &= ~(__WALL | __WCLONE);
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flags |= WNOHANG;
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/* Block all signals while here. This avoids knowing about
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LinuxThread's signals. */
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sigfillset (&block_mask);
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sigprocmask (SIG_BLOCK, &block_mask, &org_mask);
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/* ... except during the sigsuspend below. */
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sigemptyset (&wake_mask);
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while (1)
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{
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/* Since all signals are blocked, there's no need to check
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for EINTR here. */
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ret = waitpid (pid, status, flags);
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out_errno = errno;
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if (ret == -1 && out_errno != ECHILD)
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break;
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else if (ret > 0)
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break;
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if (flags & __WCLONE)
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{
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/* We've tried both flavors now. If WNOHANG is set,
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there's nothing else to do, just bail out. */
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if (wnohang)
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break;
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if (debug_threads)
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fprintf (stderr, "blocking\n");
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/* Block waiting for signals. */
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sigsuspend (&wake_mask);
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}
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flags ^= __WCLONE;
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}
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sigprocmask (SIG_SETMASK, &org_mask, NULL);
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}
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else
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{
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do
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ret = waitpid (pid, status, flags);
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while (ret == -1 && errno == EINTR);
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out_errno = errno;
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}
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if (debug_threads)
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fprintf (stderr, "my_waitpid (%d, 0x%x): status(%x), %d\n",
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pid, flags, status ? *status : -1, ret);
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errno = out_errno;
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return ret;
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}
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/* Handle a GNU/Linux extended wait response. If we see a clone
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event, we need to add the new LWP to our list (and not report the
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trap to higher layers). */
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static void
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handle_extended_wait (struct lwp_info *event_child, int wstat)
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{
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int event = wstat >> 16;
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struct lwp_info *new_lwp;
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if (event == PTRACE_EVENT_CLONE)
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{
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ptid_t ptid;
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unsigned long new_pid;
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int ret, status = W_STOPCODE (SIGSTOP);
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ptrace (PTRACE_GETEVENTMSG, lwpid_of (event_child), 0, &new_pid);
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/* If we haven't already seen the new PID stop, wait for it now. */
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if (! pull_pid_from_list (&stopped_pids, new_pid))
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{
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/* The new child has a pending SIGSTOP. We can't affect it until it
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hits the SIGSTOP, but we're already attached. */
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ret = my_waitpid (new_pid, &status, __WALL);
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if (ret == -1)
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perror_with_name ("waiting for new child");
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else if (ret != new_pid)
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warning ("wait returned unexpected PID %d", ret);
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else if (!WIFSTOPPED (status))
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warning ("wait returned unexpected status 0x%x", status);
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}
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linux_enable_event_reporting (new_pid);
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ptid = ptid_build (pid_of (event_child), new_pid, 0);
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new_lwp = (struct lwp_info *) add_lwp (ptid);
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add_thread (ptid, new_lwp);
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/* Either we're going to immediately resume the new thread
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or leave it stopped. linux_resume_one_lwp is a nop if it
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thinks the thread is currently running, so set this first
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before calling linux_resume_one_lwp. */
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new_lwp->stopped = 1;
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/* Normally we will get the pending SIGSTOP. But in some cases
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we might get another signal delivered to the group first.
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If we do get another signal, be sure not to lose it. */
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if (WSTOPSIG (status) == SIGSTOP)
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{
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if (stopping_threads)
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new_lwp->stop_pc = get_stop_pc (new_lwp);
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else
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linux_resume_one_lwp (new_lwp, 0, 0, NULL);
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}
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else
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{
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new_lwp->stop_expected = 1;
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if (stopping_threads)
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{
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new_lwp->stop_pc = get_stop_pc (new_lwp);
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new_lwp->status_pending_p = 1;
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new_lwp->status_pending = status;
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}
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else
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/* Pass the signal on. This is what GDB does - except
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shouldn't we really report it instead? */
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linux_resume_one_lwp (new_lwp, 0, WSTOPSIG (status), NULL);
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}
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/* Always resume the current thread. If we are stopping
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threads, it will have a pending SIGSTOP; we may as well
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collect it now. */
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linux_resume_one_lwp (event_child, event_child->stepping, 0, NULL);
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}
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}
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/* Return the PC as read from the regcache of LWP, without any
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adjustment. */
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static CORE_ADDR
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get_pc (struct lwp_info *lwp)
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{
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struct thread_info *saved_inferior;
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struct regcache *regcache;
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CORE_ADDR pc;
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if (the_low_target.get_pc == NULL)
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return 0;
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saved_inferior = current_inferior;
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current_inferior = get_lwp_thread (lwp);
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regcache = get_thread_regcache (current_inferior, 1);
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pc = (*the_low_target.get_pc) (regcache);
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if (debug_threads)
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fprintf (stderr, "pc is 0x%lx\n", (long) pc);
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current_inferior = saved_inferior;
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return pc;
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}
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/* This function should only be called if LWP got a SIGTRAP.
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The SIGTRAP could mean several things.
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On i386, where decr_pc_after_break is non-zero:
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If we were single-stepping this process using PTRACE_SINGLESTEP,
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we will get only the one SIGTRAP (even if the instruction we
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stepped over was a breakpoint). The value of $eip will be the
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next instruction.
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If we continue the process using PTRACE_CONT, we will get a
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SIGTRAP when we hit a breakpoint. The value of $eip will be
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the instruction after the breakpoint (i.e. needs to be
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decremented). If we report the SIGTRAP to GDB, we must also
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report the undecremented PC. If we cancel the SIGTRAP, we
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must resume at the decremented PC.
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(Presumably, not yet tested) On a non-decr_pc_after_break machine
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with hardware or kernel single-step:
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If we single-step over a breakpoint instruction, our PC will
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point at the following instruction. If we continue and hit a
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breakpoint instruction, our PC will point at the breakpoint
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instruction. */
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static CORE_ADDR
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get_stop_pc (struct lwp_info *lwp)
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{
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CORE_ADDR stop_pc;
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if (the_low_target.get_pc == NULL)
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return 0;
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|
|
stop_pc = get_pc (lwp);
|
|
|
|
if (WSTOPSIG (lwp->last_status) == SIGTRAP
|
|
&& !lwp->stepping
|
|
&& !lwp->stopped_by_watchpoint
|
|
&& lwp->last_status >> 16 == 0)
|
|
stop_pc -= the_low_target.decr_pc_after_break;
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr, "stop pc is 0x%lx\n", (long) stop_pc);
|
|
|
|
return stop_pc;
|
|
}
|
|
|
|
static void *
|
|
add_lwp (ptid_t ptid)
|
|
{
|
|
struct lwp_info *lwp;
|
|
|
|
lwp = (struct lwp_info *) xmalloc (sizeof (*lwp));
|
|
memset (lwp, 0, sizeof (*lwp));
|
|
|
|
lwp->head.id = ptid;
|
|
|
|
if (the_low_target.new_thread != NULL)
|
|
lwp->arch_private = the_low_target.new_thread ();
|
|
|
|
add_inferior_to_list (&all_lwps, &lwp->head);
|
|
|
|
return lwp;
|
|
}
|
|
|
|
/* Start an inferior process and returns its pid.
|
|
ALLARGS is a vector of program-name and args. */
|
|
|
|
static int
|
|
linux_create_inferior (char *program, char **allargs)
|
|
{
|
|
struct lwp_info *new_lwp;
|
|
int pid;
|
|
ptid_t ptid;
|
|
|
|
#if defined(__UCLIBC__) && defined(HAS_NOMMU)
|
|
pid = vfork ();
|
|
#else
|
|
pid = fork ();
|
|
#endif
|
|
if (pid < 0)
|
|
perror_with_name ("fork");
|
|
|
|
if (pid == 0)
|
|
{
|
|
ptrace (PTRACE_TRACEME, 0, 0, 0);
|
|
|
|
#ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
|
|
signal (__SIGRTMIN + 1, SIG_DFL);
|
|
#endif
|
|
|
|
setpgid (0, 0);
|
|
|
|
execv (program, allargs);
|
|
if (errno == ENOENT)
|
|
execvp (program, allargs);
|
|
|
|
fprintf (stderr, "Cannot exec %s: %s.\n", program,
|
|
strerror (errno));
|
|
fflush (stderr);
|
|
_exit (0177);
|
|
}
|
|
|
|
linux_add_process (pid, 0);
|
|
|
|
ptid = ptid_build (pid, pid, 0);
|
|
new_lwp = add_lwp (ptid);
|
|
add_thread (ptid, new_lwp);
|
|
new_lwp->must_set_ptrace_flags = 1;
|
|
|
|
return pid;
|
|
}
|
|
|
|
/* Attach to an inferior process. */
|
|
|
|
static void
|
|
linux_attach_lwp_1 (unsigned long lwpid, int initial)
|
|
{
|
|
ptid_t ptid;
|
|
struct lwp_info *new_lwp;
|
|
|
|
if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) != 0)
|
|
{
|
|
if (!initial)
|
|
{
|
|
/* If we fail to attach to an LWP, just warn. */
|
|
fprintf (stderr, "Cannot attach to lwp %ld: %s (%d)\n", lwpid,
|
|
strerror (errno), errno);
|
|
fflush (stderr);
|
|
return;
|
|
}
|
|
else
|
|
/* If we fail to attach to a process, report an error. */
|
|
error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid,
|
|
strerror (errno), errno);
|
|
}
|
|
|
|
if (initial)
|
|
/* NOTE/FIXME: This lwp might have not been the tgid. */
|
|
ptid = ptid_build (lwpid, lwpid, 0);
|
|
else
|
|
{
|
|
/* Note that extracting the pid from the current inferior is
|
|
safe, since we're always called in the context of the same
|
|
process as this new thread. */
|
|
int pid = pid_of (get_thread_lwp (current_inferior));
|
|
ptid = ptid_build (pid, lwpid, 0);
|
|
}
|
|
|
|
new_lwp = (struct lwp_info *) add_lwp (ptid);
|
|
add_thread (ptid, new_lwp);
|
|
|
|
/* We need to wait for SIGSTOP before being able to make the next
|
|
ptrace call on this LWP. */
|
|
new_lwp->must_set_ptrace_flags = 1;
|
|
|
|
/* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
|
|
brings it to a halt.
|
|
|
|
There are several cases to consider here:
|
|
|
|
1) gdbserver has already attached to the process and is being notified
|
|
of a new thread that is being created.
|
|
In this case we should ignore that SIGSTOP and resume the
|
|
process. This is handled below by setting stop_expected = 1,
|
|
and the fact that add_thread sets last_resume_kind ==
|
|
resume_continue.
|
|
|
|
2) This is the first thread (the process thread), and we're attaching
|
|
to it via attach_inferior.
|
|
In this case we want the process thread to stop.
|
|
This is handled by having linux_attach set last_resume_kind ==
|
|
resume_stop after we return.
|
|
??? If the process already has several threads we leave the other
|
|
threads running.
|
|
|
|
3) GDB is connecting to gdbserver and is requesting an enumeration of all
|
|
existing threads.
|
|
In this case we want the thread to stop.
|
|
FIXME: This case is currently not properly handled.
|
|
We should wait for the SIGSTOP but don't. Things work apparently
|
|
because enough time passes between when we ptrace (ATTACH) and when
|
|
gdb makes the next ptrace call on the thread.
|
|
|
|
On the other hand, if we are currently trying to stop all threads, we
|
|
should treat the new thread as if we had sent it a SIGSTOP. This works
|
|
because we are guaranteed that the add_lwp call above added us to the
|
|
end of the list, and so the new thread has not yet reached
|
|
wait_for_sigstop (but will). */
|
|
new_lwp->stop_expected = 1;
|
|
}
|
|
|
|
void
|
|
linux_attach_lwp (unsigned long lwpid)
|
|
{
|
|
linux_attach_lwp_1 (lwpid, 0);
|
|
}
|
|
|
|
int
|
|
linux_attach (unsigned long pid)
|
|
{
|
|
linux_attach_lwp_1 (pid, 1);
|
|
linux_add_process (pid, 1);
|
|
|
|
if (!non_stop)
|
|
{
|
|
struct thread_info *thread;
|
|
|
|
/* Don't ignore the initial SIGSTOP if we just attached to this
|
|
process. It will be collected by wait shortly. */
|
|
thread = find_thread_ptid (ptid_build (pid, pid, 0));
|
|
thread->last_resume_kind = resume_stop;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct counter
|
|
{
|
|
int pid;
|
|
int count;
|
|
};
|
|
|
|
static int
|
|
second_thread_of_pid_p (struct inferior_list_entry *entry, void *args)
|
|
{
|
|
struct counter *counter = args;
|
|
|
|
if (ptid_get_pid (entry->id) == counter->pid)
|
|
{
|
|
if (++counter->count > 1)
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
last_thread_of_process_p (struct thread_info *thread)
|
|
{
|
|
ptid_t ptid = ((struct inferior_list_entry *)thread)->id;
|
|
int pid = ptid_get_pid (ptid);
|
|
struct counter counter = { pid , 0 };
|
|
|
|
return (find_inferior (&all_threads,
|
|
second_thread_of_pid_p, &counter) == NULL);
|
|
}
|
|
|
|
/* Kill the inferior lwp. */
|
|
|
|
static int
|
|
linux_kill_one_lwp (struct inferior_list_entry *entry, void *args)
|
|
{
|
|
struct thread_info *thread = (struct thread_info *) entry;
|
|
struct lwp_info *lwp = get_thread_lwp (thread);
|
|
int wstat;
|
|
int pid = * (int *) args;
|
|
|
|
if (ptid_get_pid (entry->id) != pid)
|
|
return 0;
|
|
|
|
/* We avoid killing the first thread here, because of a Linux kernel (at
|
|
least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
|
|
the children get a chance to be reaped, it will remain a zombie
|
|
forever. */
|
|
|
|
if (lwpid_of (lwp) == pid)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "lkop: is last of process %s\n",
|
|
target_pid_to_str (entry->id));
|
|
return 0;
|
|
}
|
|
|
|
do
|
|
{
|
|
ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0);
|
|
|
|
/* Make sure it died. The loop is most likely unnecessary. */
|
|
pid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
|
|
} while (pid > 0 && WIFSTOPPED (wstat));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
linux_kill (int pid)
|
|
{
|
|
struct process_info *process;
|
|
struct lwp_info *lwp;
|
|
int wstat;
|
|
int lwpid;
|
|
|
|
process = find_process_pid (pid);
|
|
if (process == NULL)
|
|
return -1;
|
|
|
|
/* If we're killing a running inferior, make sure it is stopped
|
|
first, as PTRACE_KILL will not work otherwise. */
|
|
stop_all_lwps (0, NULL);
|
|
|
|
find_inferior (&all_threads, linux_kill_one_lwp, &pid);
|
|
|
|
/* See the comment in linux_kill_one_lwp. We did not kill the first
|
|
thread in the list, so do so now. */
|
|
lwp = find_lwp_pid (pid_to_ptid (pid));
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr, "lk_1: killing lwp %ld, for pid: %d\n",
|
|
lwpid_of (lwp), pid);
|
|
|
|
do
|
|
{
|
|
ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0);
|
|
|
|
/* Make sure it died. The loop is most likely unnecessary. */
|
|
lwpid = linux_wait_for_event (lwp->head.id, &wstat, __WALL);
|
|
} while (lwpid > 0 && WIFSTOPPED (wstat));
|
|
|
|
the_target->mourn (process);
|
|
|
|
/* Since we presently can only stop all lwps of all processes, we
|
|
need to unstop lwps of other processes. */
|
|
unstop_all_lwps (0, NULL);
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
linux_detach_one_lwp (struct inferior_list_entry *entry, void *args)
|
|
{
|
|
struct thread_info *thread = (struct thread_info *) entry;
|
|
struct lwp_info *lwp = get_thread_lwp (thread);
|
|
int pid = * (int *) args;
|
|
|
|
if (ptid_get_pid (entry->id) != pid)
|
|
return 0;
|
|
|
|
/* If this process is stopped but is expecting a SIGSTOP, then make
|
|
sure we take care of that now. This isn't absolutely guaranteed
|
|
to collect the SIGSTOP, but is fairly likely to. */
|
|
if (lwp->stop_expected)
|
|
{
|
|
int wstat;
|
|
/* Clear stop_expected, so that the SIGSTOP will be reported. */
|
|
lwp->stop_expected = 0;
|
|
linux_resume_one_lwp (lwp, 0, 0, NULL);
|
|
linux_wait_for_event (lwp->head.id, &wstat, __WALL);
|
|
}
|
|
|
|
/* Flush any pending changes to the process's registers. */
|
|
regcache_invalidate_one ((struct inferior_list_entry *)
|
|
get_lwp_thread (lwp));
|
|
|
|
/* Finally, let it resume. */
|
|
ptrace (PTRACE_DETACH, lwpid_of (lwp), 0, 0);
|
|
|
|
delete_lwp (lwp);
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
linux_detach (int pid)
|
|
{
|
|
struct process_info *process;
|
|
|
|
process = find_process_pid (pid);
|
|
if (process == NULL)
|
|
return -1;
|
|
|
|
/* Stop all threads before detaching. First, ptrace requires that
|
|
the thread is stopped to sucessfully detach. Second, thread_db
|
|
may need to uninstall thread event breakpoints from memory, which
|
|
only works with a stopped process anyway. */
|
|
stop_all_lwps (0, NULL);
|
|
|
|
#ifdef USE_THREAD_DB
|
|
thread_db_detach (process);
|
|
#endif
|
|
|
|
/* Stabilize threads (move out of jump pads). */
|
|
stabilize_threads ();
|
|
|
|
find_inferior (&all_threads, linux_detach_one_lwp, &pid);
|
|
|
|
the_target->mourn (process);
|
|
|
|
/* Since we presently can only stop all lwps of all processes, we
|
|
need to unstop lwps of other processes. */
|
|
unstop_all_lwps (0, NULL);
|
|
return 0;
|
|
}
|
|
|
|
/* Remove all LWPs that belong to process PROC from the lwp list. */
|
|
|
|
static int
|
|
delete_lwp_callback (struct inferior_list_entry *entry, void *proc)
|
|
{
|
|
struct lwp_info *lwp = (struct lwp_info *) entry;
|
|
struct process_info *process = proc;
|
|
|
|
if (pid_of (lwp) == pid_of (process))
|
|
delete_lwp (lwp);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
linux_mourn (struct process_info *process)
|
|
{
|
|
struct process_info_private *priv;
|
|
|
|
#ifdef USE_THREAD_DB
|
|
thread_db_mourn (process);
|
|
#endif
|
|
|
|
find_inferior (&all_lwps, delete_lwp_callback, process);
|
|
|
|
/* Freeing all private data. */
|
|
priv = process->private;
|
|
free (priv->arch_private);
|
|
free (priv);
|
|
process->private = NULL;
|
|
|
|
remove_process (process);
|
|
}
|
|
|
|
static void
|
|
linux_join (int pid)
|
|
{
|
|
int status, ret;
|
|
struct process_info *process;
|
|
|
|
process = find_process_pid (pid);
|
|
if (process == NULL)
|
|
return;
|
|
|
|
do {
|
|
ret = my_waitpid (pid, &status, 0);
|
|
if (WIFEXITED (status) || WIFSIGNALED (status))
|
|
break;
|
|
} while (ret != -1 || errno != ECHILD);
|
|
}
|
|
|
|
/* Return nonzero if the given thread is still alive. */
|
|
static int
|
|
linux_thread_alive (ptid_t ptid)
|
|
{
|
|
struct lwp_info *lwp = find_lwp_pid (ptid);
|
|
|
|
/* We assume we always know if a thread exits. If a whole process
|
|
exited but we still haven't been able to report it to GDB, we'll
|
|
hold on to the last lwp of the dead process. */
|
|
if (lwp != NULL)
|
|
return !lwp->dead;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
/* Return 1 if this lwp has an interesting status pending. */
|
|
static int
|
|
status_pending_p_callback (struct inferior_list_entry *entry, void *arg)
|
|
{
|
|
struct lwp_info *lwp = (struct lwp_info *) entry;
|
|
ptid_t ptid = * (ptid_t *) arg;
|
|
struct thread_info *thread;
|
|
|
|
/* Check if we're only interested in events from a specific process
|
|
or its lwps. */
|
|
if (!ptid_equal (minus_one_ptid, ptid)
|
|
&& ptid_get_pid (ptid) != ptid_get_pid (lwp->head.id))
|
|
return 0;
|
|
|
|
thread = get_lwp_thread (lwp);
|
|
|
|
/* If we got a `vCont;t', but we haven't reported a stop yet, do
|
|
report any status pending the LWP may have. */
|
|
if (thread->last_resume_kind == resume_stop
|
|
&& thread->last_status.kind != TARGET_WAITKIND_IGNORE)
|
|
return 0;
|
|
|
|
return lwp->status_pending_p;
|
|
}
|
|
|
|
static int
|
|
same_lwp (struct inferior_list_entry *entry, void *data)
|
|
{
|
|
ptid_t ptid = *(ptid_t *) data;
|
|
int lwp;
|
|
|
|
if (ptid_get_lwp (ptid) != 0)
|
|
lwp = ptid_get_lwp (ptid);
|
|
else
|
|
lwp = ptid_get_pid (ptid);
|
|
|
|
if (ptid_get_lwp (entry->id) == lwp)
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct lwp_info *
|
|
find_lwp_pid (ptid_t ptid)
|
|
{
|
|
return (struct lwp_info*) find_inferior (&all_lwps, same_lwp, &ptid);
|
|
}
|
|
|
|
static struct lwp_info *
|
|
linux_wait_for_lwp (ptid_t ptid, int *wstatp, int options)
|
|
{
|
|
int ret;
|
|
int to_wait_for = -1;
|
|
struct lwp_info *child = NULL;
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid));
|
|
|
|
if (ptid_equal (ptid, minus_one_ptid))
|
|
to_wait_for = -1; /* any child */
|
|
else
|
|
to_wait_for = ptid_get_lwp (ptid); /* this lwp only */
|
|
|
|
options |= __WALL;
|
|
|
|
retry:
|
|
|
|
ret = my_waitpid (to_wait_for, wstatp, options);
|
|
if (ret == 0 || (ret == -1 && errno == ECHILD && (options & WNOHANG)))
|
|
return NULL;
|
|
else if (ret == -1)
|
|
perror_with_name ("waitpid");
|
|
|
|
if (debug_threads
|
|
&& (!WIFSTOPPED (*wstatp)
|
|
|| (WSTOPSIG (*wstatp) != 32
|
|
&& WSTOPSIG (*wstatp) != 33)))
|
|
fprintf (stderr, "Got an event from %d (%x)\n", ret, *wstatp);
|
|
|
|
child = find_lwp_pid (pid_to_ptid (ret));
|
|
|
|
/* If we didn't find a process, one of two things presumably happened:
|
|
- A process we started and then detached from has exited. Ignore it.
|
|
- A process we are controlling has forked and the new child's stop
|
|
was reported to us by the kernel. Save its PID. */
|
|
if (child == NULL && WIFSTOPPED (*wstatp))
|
|
{
|
|
add_pid_to_list (&stopped_pids, ret);
|
|
goto retry;
|
|
}
|
|
else if (child == NULL)
|
|
goto retry;
|
|
|
|
child->stopped = 1;
|
|
|
|
child->last_status = *wstatp;
|
|
|
|
/* Architecture-specific setup after inferior is running.
|
|
This needs to happen after we have attached to the inferior
|
|
and it is stopped for the first time, but before we access
|
|
any inferior registers. */
|
|
if (new_inferior)
|
|
{
|
|
the_low_target.arch_setup ();
|
|
#ifdef HAVE_LINUX_REGSETS
|
|
memset (disabled_regsets, 0, num_regsets);
|
|
#endif
|
|
new_inferior = 0;
|
|
}
|
|
|
|
/* Fetch the possibly triggered data watchpoint info and store it in
|
|
CHILD.
|
|
|
|
On some archs, like x86, that use debug registers to set
|
|
watchpoints, it's possible that the way to know which watched
|
|
address trapped, is to check the register that is used to select
|
|
which address to watch. Problem is, between setting the
|
|
watchpoint and reading back which data address trapped, the user
|
|
may change the set of watchpoints, and, as a consequence, GDB
|
|
changes the debug registers in the inferior. To avoid reading
|
|
back a stale stopped-data-address when that happens, we cache in
|
|
LP the fact that a watchpoint trapped, and the corresponding data
|
|
address, as soon as we see CHILD stop with a SIGTRAP. If GDB
|
|
changes the debug registers meanwhile, we have the cached data we
|
|
can rely on. */
|
|
|
|
if (WIFSTOPPED (*wstatp) && WSTOPSIG (*wstatp) == SIGTRAP)
|
|
{
|
|
if (the_low_target.stopped_by_watchpoint == NULL)
|
|
{
|
|
child->stopped_by_watchpoint = 0;
|
|
}
|
|
else
|
|
{
|
|
struct thread_info *saved_inferior;
|
|
|
|
saved_inferior = current_inferior;
|
|
current_inferior = get_lwp_thread (child);
|
|
|
|
child->stopped_by_watchpoint
|
|
= the_low_target.stopped_by_watchpoint ();
|
|
|
|
if (child->stopped_by_watchpoint)
|
|
{
|
|
if (the_low_target.stopped_data_address != NULL)
|
|
child->stopped_data_address
|
|
= the_low_target.stopped_data_address ();
|
|
else
|
|
child->stopped_data_address = 0;
|
|
}
|
|
|
|
current_inferior = saved_inferior;
|
|
}
|
|
}
|
|
|
|
/* Store the STOP_PC, with adjustment applied. This depends on the
|
|
architecture being defined already (so that CHILD has a valid
|
|
regcache), and on LAST_STATUS being set (to check for SIGTRAP or
|
|
not). */
|
|
if (WIFSTOPPED (*wstatp))
|
|
child->stop_pc = get_stop_pc (child);
|
|
|
|
if (debug_threads
|
|
&& WIFSTOPPED (*wstatp)
|
|
&& the_low_target.get_pc != NULL)
|
|
{
|
|
struct thread_info *saved_inferior = current_inferior;
|
|
struct regcache *regcache;
|
|
CORE_ADDR pc;
|
|
|
|
current_inferior = get_lwp_thread (child);
|
|
regcache = get_thread_regcache (current_inferior, 1);
|
|
pc = (*the_low_target.get_pc) (regcache);
|
|
fprintf (stderr, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc);
|
|
current_inferior = saved_inferior;
|
|
}
|
|
|
|
return child;
|
|
}
|
|
|
|
/* This function should only be called if the LWP got a SIGTRAP.
|
|
|
|
Handle any tracepoint steps or hits. Return true if a tracepoint
|
|
event was handled, 0 otherwise. */
|
|
|
|
static int
|
|
handle_tracepoints (struct lwp_info *lwp)
|
|
{
|
|
struct thread_info *tinfo = get_lwp_thread (lwp);
|
|
int tpoint_related_event = 0;
|
|
|
|
/* If this tracepoint hit causes a tracing stop, we'll immediately
|
|
uninsert tracepoints. To do this, we temporarily pause all
|
|
threads, unpatch away, and then unpause threads. We need to make
|
|
sure the unpausing doesn't resume LWP too. */
|
|
lwp->suspended++;
|
|
|
|
/* And we need to be sure that any all-threads-stopping doesn't try
|
|
to move threads out of the jump pads, as it could deadlock the
|
|
inferior (LWP could be in the jump pad, maybe even holding the
|
|
lock.) */
|
|
|
|
/* Do any necessary step collect actions. */
|
|
tpoint_related_event |= tracepoint_finished_step (tinfo, lwp->stop_pc);
|
|
|
|
tpoint_related_event |= handle_tracepoint_bkpts (tinfo, lwp->stop_pc);
|
|
|
|
/* See if we just hit a tracepoint and do its main collect
|
|
actions. */
|
|
tpoint_related_event |= tracepoint_was_hit (tinfo, lwp->stop_pc);
|
|
|
|
lwp->suspended--;
|
|
|
|
gdb_assert (lwp->suspended == 0);
|
|
gdb_assert (!stabilizing_threads || lwp->collecting_fast_tracepoint);
|
|
|
|
if (tpoint_related_event)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "got a tracepoint event\n");
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Convenience wrapper. Returns true if LWP is presently collecting a
|
|
fast tracepoint. */
|
|
|
|
static int
|
|
linux_fast_tracepoint_collecting (struct lwp_info *lwp,
|
|
struct fast_tpoint_collect_status *status)
|
|
{
|
|
CORE_ADDR thread_area;
|
|
|
|
if (the_low_target.get_thread_area == NULL)
|
|
return 0;
|
|
|
|
/* Get the thread area address. This is used to recognize which
|
|
thread is which when tracing with the in-process agent library.
|
|
We don't read anything from the address, and treat it as opaque;
|
|
it's the address itself that we assume is unique per-thread. */
|
|
if ((*the_low_target.get_thread_area) (lwpid_of (lwp), &thread_area) == -1)
|
|
return 0;
|
|
|
|
return fast_tracepoint_collecting (thread_area, lwp->stop_pc, status);
|
|
}
|
|
|
|
/* The reason we resume in the caller, is because we want to be able
|
|
to pass lwp->status_pending as WSTAT, and we need to clear
|
|
status_pending_p before resuming, otherwise, linux_resume_one_lwp
|
|
refuses to resume. */
|
|
|
|
static int
|
|
maybe_move_out_of_jump_pad (struct lwp_info *lwp, int *wstat)
|
|
{
|
|
struct thread_info *saved_inferior;
|
|
|
|
saved_inferior = current_inferior;
|
|
current_inferior = get_lwp_thread (lwp);
|
|
|
|
if ((wstat == NULL
|
|
|| (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) != SIGTRAP))
|
|
&& supports_fast_tracepoints ()
|
|
&& in_process_agent_loaded ())
|
|
{
|
|
struct fast_tpoint_collect_status status;
|
|
int r;
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr, "\
|
|
Checking whether LWP %ld needs to move out of the jump pad.\n",
|
|
lwpid_of (lwp));
|
|
|
|
r = linux_fast_tracepoint_collecting (lwp, &status);
|
|
|
|
if (wstat == NULL
|
|
|| (WSTOPSIG (*wstat) != SIGILL
|
|
&& WSTOPSIG (*wstat) != SIGFPE
|
|
&& WSTOPSIG (*wstat) != SIGSEGV
|
|
&& WSTOPSIG (*wstat) != SIGBUS))
|
|
{
|
|
lwp->collecting_fast_tracepoint = r;
|
|
|
|
if (r != 0)
|
|
{
|
|
if (r == 1 && lwp->exit_jump_pad_bkpt == NULL)
|
|
{
|
|
/* Haven't executed the original instruction yet.
|
|
Set breakpoint there, and wait till it's hit,
|
|
then single-step until exiting the jump pad. */
|
|
lwp->exit_jump_pad_bkpt
|
|
= set_breakpoint_at (status.adjusted_insn_addr, NULL);
|
|
}
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr, "\
|
|
Checking whether LWP %ld needs to move out of the jump pad...it does\n",
|
|
lwpid_of (lwp));
|
|
current_inferior = saved_inferior;
|
|
|
|
return 1;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* If we get a synchronous signal while collecting, *and*
|
|
while executing the (relocated) original instruction,
|
|
reset the PC to point at the tpoint address, before
|
|
reporting to GDB. Otherwise, it's an IPA lib bug: just
|
|
report the signal to GDB, and pray for the best. */
|
|
|
|
lwp->collecting_fast_tracepoint = 0;
|
|
|
|
if (r != 0
|
|
&& (status.adjusted_insn_addr <= lwp->stop_pc
|
|
&& lwp->stop_pc < status.adjusted_insn_addr_end))
|
|
{
|
|
siginfo_t info;
|
|
struct regcache *regcache;
|
|
|
|
/* The si_addr on a few signals references the address
|
|
of the faulting instruction. Adjust that as
|
|
well. */
|
|
if ((WSTOPSIG (*wstat) == SIGILL
|
|
|| WSTOPSIG (*wstat) == SIGFPE
|
|
|| WSTOPSIG (*wstat) == SIGBUS
|
|
|| WSTOPSIG (*wstat) == SIGSEGV)
|
|
&& ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &info) == 0
|
|
/* Final check just to make sure we don't clobber
|
|
the siginfo of non-kernel-sent signals. */
|
|
&& (uintptr_t) info.si_addr == lwp->stop_pc)
|
|
{
|
|
info.si_addr = (void *) (uintptr_t) status.tpoint_addr;
|
|
ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &info);
|
|
}
|
|
|
|
regcache = get_thread_regcache (get_lwp_thread (lwp), 1);
|
|
(*the_low_target.set_pc) (regcache, status.tpoint_addr);
|
|
lwp->stop_pc = status.tpoint_addr;
|
|
|
|
/* Cancel any fast tracepoint lock this thread was
|
|
holding. */
|
|
force_unlock_trace_buffer ();
|
|
}
|
|
|
|
if (lwp->exit_jump_pad_bkpt != NULL)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"Cancelling fast exit-jump-pad: removing bkpt. "
|
|
"stopping all threads momentarily.\n");
|
|
|
|
stop_all_lwps (1, lwp);
|
|
cancel_breakpoints ();
|
|
|
|
delete_breakpoint (lwp->exit_jump_pad_bkpt);
|
|
lwp->exit_jump_pad_bkpt = NULL;
|
|
|
|
unstop_all_lwps (1, lwp);
|
|
|
|
gdb_assert (lwp->suspended >= 0);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr, "\
|
|
Checking whether LWP %ld needs to move out of the jump pad...no\n",
|
|
lwpid_of (lwp));
|
|
|
|
current_inferior = saved_inferior;
|
|
return 0;
|
|
}
|
|
|
|
/* Enqueue one signal in the "signals to report later when out of the
|
|
jump pad" list. */
|
|
|
|
static void
|
|
enqueue_one_deferred_signal (struct lwp_info *lwp, int *wstat)
|
|
{
|
|
struct pending_signals *p_sig;
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr, "\
|
|
Deferring signal %d for LWP %ld.\n", WSTOPSIG (*wstat), lwpid_of (lwp));
|
|
|
|
if (debug_threads)
|
|
{
|
|
struct pending_signals *sig;
|
|
|
|
for (sig = lwp->pending_signals_to_report;
|
|
sig != NULL;
|
|
sig = sig->prev)
|
|
fprintf (stderr,
|
|
" Already queued %d\n",
|
|
sig->signal);
|
|
|
|
fprintf (stderr, " (no more currently queued signals)\n");
|
|
}
|
|
|
|
/* Don't enqueue non-RT signals if they are already in the deferred
|
|
queue. (SIGSTOP being the easiest signal to see ending up here
|
|
twice) */
|
|
if (WSTOPSIG (*wstat) < __SIGRTMIN)
|
|
{
|
|
struct pending_signals *sig;
|
|
|
|
for (sig = lwp->pending_signals_to_report;
|
|
sig != NULL;
|
|
sig = sig->prev)
|
|
{
|
|
if (sig->signal == WSTOPSIG (*wstat))
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"Not requeuing already queued non-RT signal %d"
|
|
" for LWP %ld\n",
|
|
sig->signal,
|
|
lwpid_of (lwp));
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
p_sig = xmalloc (sizeof (*p_sig));
|
|
p_sig->prev = lwp->pending_signals_to_report;
|
|
p_sig->signal = WSTOPSIG (*wstat);
|
|
memset (&p_sig->info, 0, sizeof (siginfo_t));
|
|
ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info);
|
|
|
|
lwp->pending_signals_to_report = p_sig;
|
|
}
|
|
|
|
/* Dequeue one signal from the "signals to report later when out of
|
|
the jump pad" list. */
|
|
|
|
static int
|
|
dequeue_one_deferred_signal (struct lwp_info *lwp, int *wstat)
|
|
{
|
|
if (lwp->pending_signals_to_report != NULL)
|
|
{
|
|
struct pending_signals **p_sig;
|
|
|
|
p_sig = &lwp->pending_signals_to_report;
|
|
while ((*p_sig)->prev != NULL)
|
|
p_sig = &(*p_sig)->prev;
|
|
|
|
*wstat = W_STOPCODE ((*p_sig)->signal);
|
|
if ((*p_sig)->info.si_signo != 0)
|
|
ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &(*p_sig)->info);
|
|
free (*p_sig);
|
|
*p_sig = NULL;
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr, "Reporting deferred signal %d for LWP %ld.\n",
|
|
WSTOPSIG (*wstat), lwpid_of (lwp));
|
|
|
|
if (debug_threads)
|
|
{
|
|
struct pending_signals *sig;
|
|
|
|
for (sig = lwp->pending_signals_to_report;
|
|
sig != NULL;
|
|
sig = sig->prev)
|
|
fprintf (stderr,
|
|
" Still queued %d\n",
|
|
sig->signal);
|
|
|
|
fprintf (stderr, " (no more queued signals)\n");
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Arrange for a breakpoint to be hit again later. We don't keep the
|
|
SIGTRAP status and don't forward the SIGTRAP signal to the LWP. We
|
|
will handle the current event, eventually we will resume this LWP,
|
|
and this breakpoint will trap again. */
|
|
|
|
static int
|
|
cancel_breakpoint (struct lwp_info *lwp)
|
|
{
|
|
struct thread_info *saved_inferior;
|
|
|
|
/* There's nothing to do if we don't support breakpoints. */
|
|
if (!supports_breakpoints ())
|
|
return 0;
|
|
|
|
/* breakpoint_at reads from current inferior. */
|
|
saved_inferior = current_inferior;
|
|
current_inferior = get_lwp_thread (lwp);
|
|
|
|
if ((*the_low_target.breakpoint_at) (lwp->stop_pc))
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"CB: Push back breakpoint for %s\n",
|
|
target_pid_to_str (ptid_of (lwp)));
|
|
|
|
/* Back up the PC if necessary. */
|
|
if (the_low_target.decr_pc_after_break)
|
|
{
|
|
struct regcache *regcache
|
|
= get_thread_regcache (current_inferior, 1);
|
|
(*the_low_target.set_pc) (regcache, lwp->stop_pc);
|
|
}
|
|
|
|
current_inferior = saved_inferior;
|
|
return 1;
|
|
}
|
|
else
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"CB: No breakpoint found at %s for [%s]\n",
|
|
paddress (lwp->stop_pc),
|
|
target_pid_to_str (ptid_of (lwp)));
|
|
}
|
|
|
|
current_inferior = saved_inferior;
|
|
return 0;
|
|
}
|
|
|
|
/* When the event-loop is doing a step-over, this points at the thread
|
|
being stepped. */
|
|
ptid_t step_over_bkpt;
|
|
|
|
/* Wait for an event from child PID. If PID is -1, wait for any
|
|
child. Store the stop status through the status pointer WSTAT.
|
|
OPTIONS is passed to the waitpid call. Return 0 if no child stop
|
|
event was found and OPTIONS contains WNOHANG. Return the PID of
|
|
the stopped child otherwise. */
|
|
|
|
static int
|
|
linux_wait_for_event_1 (ptid_t ptid, int *wstat, int options)
|
|
{
|
|
struct lwp_info *event_child, *requested_child;
|
|
|
|
event_child = NULL;
|
|
requested_child = NULL;
|
|
|
|
/* Check for a lwp with a pending status. */
|
|
|
|
if (ptid_equal (ptid, minus_one_ptid)
|
|
|| ptid_equal (pid_to_ptid (ptid_get_pid (ptid)), ptid))
|
|
{
|
|
event_child = (struct lwp_info *)
|
|
find_inferior (&all_lwps, status_pending_p_callback, &ptid);
|
|
if (debug_threads && event_child)
|
|
fprintf (stderr, "Got a pending child %ld\n", lwpid_of (event_child));
|
|
}
|
|
else
|
|
{
|
|
requested_child = find_lwp_pid (ptid);
|
|
|
|
if (!stopping_threads
|
|
&& requested_child->status_pending_p
|
|
&& requested_child->collecting_fast_tracepoint)
|
|
{
|
|
enqueue_one_deferred_signal (requested_child,
|
|
&requested_child->status_pending);
|
|
requested_child->status_pending_p = 0;
|
|
requested_child->status_pending = 0;
|
|
linux_resume_one_lwp (requested_child, 0, 0, NULL);
|
|
}
|
|
|
|
if (requested_child->suspended
|
|
&& requested_child->status_pending_p)
|
|
fatal ("requesting an event out of a suspended child?");
|
|
|
|
if (requested_child->status_pending_p)
|
|
event_child = requested_child;
|
|
}
|
|
|
|
if (event_child != NULL)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "Got an event from pending child %ld (%04x)\n",
|
|
lwpid_of (event_child), event_child->status_pending);
|
|
*wstat = event_child->status_pending;
|
|
event_child->status_pending_p = 0;
|
|
event_child->status_pending = 0;
|
|
current_inferior = get_lwp_thread (event_child);
|
|
return lwpid_of (event_child);
|
|
}
|
|
|
|
/* We only enter this loop if no process has a pending wait status. Thus
|
|
any action taken in response to a wait status inside this loop is
|
|
responding as soon as we detect the status, not after any pending
|
|
events. */
|
|
while (1)
|
|
{
|
|
event_child = linux_wait_for_lwp (ptid, wstat, options);
|
|
|
|
if ((options & WNOHANG) && event_child == NULL)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "WNOHANG set, no event found\n");
|
|
return 0;
|
|
}
|
|
|
|
if (event_child == NULL)
|
|
error ("event from unknown child");
|
|
|
|
current_inferior = get_lwp_thread (event_child);
|
|
|
|
/* Check for thread exit. */
|
|
if (! WIFSTOPPED (*wstat))
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "LWP %ld exiting\n", lwpid_of (event_child));
|
|
|
|
/* If the last thread is exiting, just return. */
|
|
if (last_thread_of_process_p (current_inferior))
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "LWP %ld is last lwp of process\n",
|
|
lwpid_of (event_child));
|
|
return lwpid_of (event_child);
|
|
}
|
|
|
|
if (!non_stop)
|
|
{
|
|
current_inferior = (struct thread_info *) all_threads.head;
|
|
if (debug_threads)
|
|
fprintf (stderr, "Current inferior is now %ld\n",
|
|
lwpid_of (get_thread_lwp (current_inferior)));
|
|
}
|
|
else
|
|
{
|
|
current_inferior = NULL;
|
|
if (debug_threads)
|
|
fprintf (stderr, "Current inferior is now <NULL>\n");
|
|
}
|
|
|
|
/* If we were waiting for this particular child to do something...
|
|
well, it did something. */
|
|
if (requested_child != NULL)
|
|
{
|
|
int lwpid = lwpid_of (event_child);
|
|
|
|
/* Cancel the step-over operation --- the thread that
|
|
started it is gone. */
|
|
if (finish_step_over (event_child))
|
|
unstop_all_lwps (1, event_child);
|
|
delete_lwp (event_child);
|
|
return lwpid;
|
|
}
|
|
|
|
delete_lwp (event_child);
|
|
|
|
/* Wait for a more interesting event. */
|
|
continue;
|
|
}
|
|
|
|
if (event_child->must_set_ptrace_flags)
|
|
{
|
|
linux_enable_event_reporting (lwpid_of (event_child));
|
|
event_child->must_set_ptrace_flags = 0;
|
|
}
|
|
|
|
if (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) == SIGTRAP
|
|
&& *wstat >> 16 != 0)
|
|
{
|
|
handle_extended_wait (event_child, *wstat);
|
|
continue;
|
|
}
|
|
|
|
if (WIFSTOPPED (*wstat)
|
|
&& WSTOPSIG (*wstat) == SIGSTOP
|
|
&& event_child->stop_expected)
|
|
{
|
|
int should_stop;
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr, "Expected stop.\n");
|
|
event_child->stop_expected = 0;
|
|
|
|
should_stop = (current_inferior->last_resume_kind == resume_stop
|
|
|| stopping_threads);
|
|
|
|
if (!should_stop)
|
|
{
|
|
linux_resume_one_lwp (event_child,
|
|
event_child->stepping, 0, NULL);
|
|
continue;
|
|
}
|
|
}
|
|
|
|
return lwpid_of (event_child);
|
|
}
|
|
|
|
/* NOTREACHED */
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
linux_wait_for_event (ptid_t ptid, int *wstat, int options)
|
|
{
|
|
ptid_t wait_ptid;
|
|
|
|
if (ptid_is_pid (ptid))
|
|
{
|
|
/* A request to wait for a specific tgid. This is not possible
|
|
with waitpid, so instead, we wait for any child, and leave
|
|
children we're not interested in right now with a pending
|
|
status to report later. */
|
|
wait_ptid = minus_one_ptid;
|
|
}
|
|
else
|
|
wait_ptid = ptid;
|
|
|
|
while (1)
|
|
{
|
|
int event_pid;
|
|
|
|
event_pid = linux_wait_for_event_1 (wait_ptid, wstat, options);
|
|
|
|
if (event_pid > 0
|
|
&& ptid_is_pid (ptid) && ptid_get_pid (ptid) != event_pid)
|
|
{
|
|
struct lwp_info *event_child
|
|
= find_lwp_pid (pid_to_ptid (event_pid));
|
|
|
|
if (! WIFSTOPPED (*wstat))
|
|
mark_lwp_dead (event_child, *wstat);
|
|
else
|
|
{
|
|
event_child->status_pending_p = 1;
|
|
event_child->status_pending = *wstat;
|
|
}
|
|
}
|
|
else
|
|
return event_pid;
|
|
}
|
|
}
|
|
|
|
|
|
/* Count the LWP's that have had events. */
|
|
|
|
static int
|
|
count_events_callback (struct inferior_list_entry *entry, void *data)
|
|
{
|
|
struct lwp_info *lp = (struct lwp_info *) entry;
|
|
struct thread_info *thread = get_lwp_thread (lp);
|
|
int *count = data;
|
|
|
|
gdb_assert (count != NULL);
|
|
|
|
/* Count only resumed LWPs that have a SIGTRAP event pending that
|
|
should be reported to GDB. */
|
|
if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
|
|
&& thread->last_resume_kind != resume_stop
|
|
&& lp->status_pending_p
|
|
&& WIFSTOPPED (lp->status_pending)
|
|
&& WSTOPSIG (lp->status_pending) == SIGTRAP
|
|
&& !breakpoint_inserted_here (lp->stop_pc))
|
|
(*count)++;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Select the LWP (if any) that is currently being single-stepped. */
|
|
|
|
static int
|
|
select_singlestep_lwp_callback (struct inferior_list_entry *entry, void *data)
|
|
{
|
|
struct lwp_info *lp = (struct lwp_info *) entry;
|
|
struct thread_info *thread = get_lwp_thread (lp);
|
|
|
|
if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
|
|
&& thread->last_resume_kind == resume_step
|
|
&& lp->status_pending_p)
|
|
return 1;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
/* Select the Nth LWP that has had a SIGTRAP event that should be
|
|
reported to GDB. */
|
|
|
|
static int
|
|
select_event_lwp_callback (struct inferior_list_entry *entry, void *data)
|
|
{
|
|
struct lwp_info *lp = (struct lwp_info *) entry;
|
|
struct thread_info *thread = get_lwp_thread (lp);
|
|
int *selector = data;
|
|
|
|
gdb_assert (selector != NULL);
|
|
|
|
/* Select only resumed LWPs that have a SIGTRAP event pending. */
|
|
if (thread->last_resume_kind != resume_stop
|
|
&& thread->last_status.kind == TARGET_WAITKIND_IGNORE
|
|
&& lp->status_pending_p
|
|
&& WIFSTOPPED (lp->status_pending)
|
|
&& WSTOPSIG (lp->status_pending) == SIGTRAP
|
|
&& !breakpoint_inserted_here (lp->stop_pc))
|
|
if ((*selector)-- == 0)
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
cancel_breakpoints_callback (struct inferior_list_entry *entry, void *data)
|
|
{
|
|
struct lwp_info *lp = (struct lwp_info *) entry;
|
|
struct thread_info *thread = get_lwp_thread (lp);
|
|
struct lwp_info *event_lp = data;
|
|
|
|
/* Leave the LWP that has been elected to receive a SIGTRAP alone. */
|
|
if (lp == event_lp)
|
|
return 0;
|
|
|
|
/* If a LWP other than the LWP that we're reporting an event for has
|
|
hit a GDB breakpoint (as opposed to some random trap signal),
|
|
then just arrange for it to hit it again later. We don't keep
|
|
the SIGTRAP status and don't forward the SIGTRAP signal to the
|
|
LWP. We will handle the current event, eventually we will resume
|
|
all LWPs, and this one will get its breakpoint trap again.
|
|
|
|
If we do not do this, then we run the risk that the user will
|
|
delete or disable the breakpoint, but the LWP will have already
|
|
tripped on it. */
|
|
|
|
if (thread->last_resume_kind != resume_stop
|
|
&& thread->last_status.kind == TARGET_WAITKIND_IGNORE
|
|
&& lp->status_pending_p
|
|
&& WIFSTOPPED (lp->status_pending)
|
|
&& WSTOPSIG (lp->status_pending) == SIGTRAP
|
|
&& !lp->stepping
|
|
&& !lp->stopped_by_watchpoint
|
|
&& cancel_breakpoint (lp))
|
|
/* Throw away the SIGTRAP. */
|
|
lp->status_pending_p = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
linux_cancel_breakpoints (void)
|
|
{
|
|
find_inferior (&all_lwps, cancel_breakpoints_callback, NULL);
|
|
}
|
|
|
|
/* Select one LWP out of those that have events pending. */
|
|
|
|
static void
|
|
select_event_lwp (struct lwp_info **orig_lp)
|
|
{
|
|
int num_events = 0;
|
|
int random_selector;
|
|
struct lwp_info *event_lp;
|
|
|
|
/* Give preference to any LWP that is being single-stepped. */
|
|
event_lp
|
|
= (struct lwp_info *) find_inferior (&all_lwps,
|
|
select_singlestep_lwp_callback, NULL);
|
|
if (event_lp != NULL)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"SEL: Select single-step %s\n",
|
|
target_pid_to_str (ptid_of (event_lp)));
|
|
}
|
|
else
|
|
{
|
|
/* No single-stepping LWP. Select one at random, out of those
|
|
which have had SIGTRAP events. */
|
|
|
|
/* First see how many SIGTRAP events we have. */
|
|
find_inferior (&all_lwps, count_events_callback, &num_events);
|
|
|
|
/* Now randomly pick a LWP out of those that have had a SIGTRAP. */
|
|
random_selector = (int)
|
|
((num_events * (double) rand ()) / (RAND_MAX + 1.0));
|
|
|
|
if (debug_threads && num_events > 1)
|
|
fprintf (stderr,
|
|
"SEL: Found %d SIGTRAP events, selecting #%d\n",
|
|
num_events, random_selector);
|
|
|
|
event_lp = (struct lwp_info *) find_inferior (&all_lwps,
|
|
select_event_lwp_callback,
|
|
&random_selector);
|
|
}
|
|
|
|
if (event_lp != NULL)
|
|
{
|
|
/* Switch the event LWP. */
|
|
*orig_lp = event_lp;
|
|
}
|
|
}
|
|
|
|
/* Decrement the suspend count of an LWP. */
|
|
|
|
static int
|
|
unsuspend_one_lwp (struct inferior_list_entry *entry, void *except)
|
|
{
|
|
struct lwp_info *lwp = (struct lwp_info *) entry;
|
|
|
|
/* Ignore EXCEPT. */
|
|
if (lwp == except)
|
|
return 0;
|
|
|
|
lwp->suspended--;
|
|
|
|
gdb_assert (lwp->suspended >= 0);
|
|
return 0;
|
|
}
|
|
|
|
/* Decrement the suspend count of all LWPs, except EXCEPT, if non
|
|
NULL. */
|
|
|
|
static void
|
|
unsuspend_all_lwps (struct lwp_info *except)
|
|
{
|
|
find_inferior (&all_lwps, unsuspend_one_lwp, except);
|
|
}
|
|
|
|
static void move_out_of_jump_pad_callback (struct inferior_list_entry *entry);
|
|
static int stuck_in_jump_pad_callback (struct inferior_list_entry *entry,
|
|
void *data);
|
|
static int lwp_running (struct inferior_list_entry *entry, void *data);
|
|
static ptid_t linux_wait_1 (ptid_t ptid,
|
|
struct target_waitstatus *ourstatus,
|
|
int target_options);
|
|
|
|
/* Stabilize threads (move out of jump pads).
|
|
|
|
If a thread is midway collecting a fast tracepoint, we need to
|
|
finish the collection and move it out of the jump pad before
|
|
reporting the signal.
|
|
|
|
This avoids recursion while collecting (when a signal arrives
|
|
midway, and the signal handler itself collects), which would trash
|
|
the trace buffer. In case the user set a breakpoint in a signal
|
|
handler, this avoids the backtrace showing the jump pad, etc..
|
|
Most importantly, there are certain things we can't do safely if
|
|
threads are stopped in a jump pad (or in its callee's). For
|
|
example:
|
|
|
|
- starting a new trace run. A thread still collecting the
|
|
previous run, could trash the trace buffer when resumed. The trace
|
|
buffer control structures would have been reset but the thread had
|
|
no way to tell. The thread could even midway memcpy'ing to the
|
|
buffer, which would mean that when resumed, it would clobber the
|
|
trace buffer that had been set for a new run.
|
|
|
|
- we can't rewrite/reuse the jump pads for new tracepoints
|
|
safely. Say you do tstart while a thread is stopped midway while
|
|
collecting. When the thread is later resumed, it finishes the
|
|
collection, and returns to the jump pad, to execute the original
|
|
instruction that was under the tracepoint jump at the time the
|
|
older run had been started. If the jump pad had been rewritten
|
|
since for something else in the new run, the thread would now
|
|
execute the wrong / random instructions. */
|
|
|
|
static void
|
|
linux_stabilize_threads (void)
|
|
{
|
|
struct thread_info *save_inferior;
|
|
struct lwp_info *lwp_stuck;
|
|
|
|
lwp_stuck
|
|
= (struct lwp_info *) find_inferior (&all_lwps,
|
|
stuck_in_jump_pad_callback, NULL);
|
|
if (lwp_stuck != NULL)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "can't stabilize, LWP %ld is stuck in jump pad\n",
|
|
lwpid_of (lwp_stuck));
|
|
return;
|
|
}
|
|
|
|
save_inferior = current_inferior;
|
|
|
|
stabilizing_threads = 1;
|
|
|
|
/* Kick 'em all. */
|
|
for_each_inferior (&all_lwps, move_out_of_jump_pad_callback);
|
|
|
|
/* Loop until all are stopped out of the jump pads. */
|
|
while (find_inferior (&all_lwps, lwp_running, NULL) != NULL)
|
|
{
|
|
struct target_waitstatus ourstatus;
|
|
struct lwp_info *lwp;
|
|
int wstat;
|
|
|
|
/* Note that we go through the full wait even loop. While
|
|
moving threads out of jump pad, we need to be able to step
|
|
over internal breakpoints and such. */
|
|
linux_wait_1 (minus_one_ptid, &ourstatus, 0);
|
|
|
|
if (ourstatus.kind == TARGET_WAITKIND_STOPPED)
|
|
{
|
|
lwp = get_thread_lwp (current_inferior);
|
|
|
|
/* Lock it. */
|
|
lwp->suspended++;
|
|
|
|
if (ourstatus.value.sig != TARGET_SIGNAL_0
|
|
|| current_inferior->last_resume_kind == resume_stop)
|
|
{
|
|
wstat = W_STOPCODE (target_signal_to_host (ourstatus.value.sig));
|
|
enqueue_one_deferred_signal (lwp, &wstat);
|
|
}
|
|
}
|
|
}
|
|
|
|
find_inferior (&all_lwps, unsuspend_one_lwp, NULL);
|
|
|
|
stabilizing_threads = 0;
|
|
|
|
current_inferior = save_inferior;
|
|
|
|
if (debug_threads)
|
|
{
|
|
lwp_stuck
|
|
= (struct lwp_info *) find_inferior (&all_lwps,
|
|
stuck_in_jump_pad_callback, NULL);
|
|
if (lwp_stuck != NULL)
|
|
fprintf (stderr, "couldn't stabilize, LWP %ld got stuck in jump pad\n",
|
|
lwpid_of (lwp_stuck));
|
|
}
|
|
}
|
|
|
|
/* Wait for process, returns status. */
|
|
|
|
static ptid_t
|
|
linux_wait_1 (ptid_t ptid,
|
|
struct target_waitstatus *ourstatus, int target_options)
|
|
{
|
|
int w;
|
|
struct lwp_info *event_child;
|
|
int options;
|
|
int pid;
|
|
int step_over_finished;
|
|
int bp_explains_trap;
|
|
int maybe_internal_trap;
|
|
int report_to_gdb;
|
|
int trace_event;
|
|
|
|
/* Translate generic target options into linux options. */
|
|
options = __WALL;
|
|
if (target_options & TARGET_WNOHANG)
|
|
options |= WNOHANG;
|
|
|
|
retry:
|
|
bp_explains_trap = 0;
|
|
trace_event = 0;
|
|
ourstatus->kind = TARGET_WAITKIND_IGNORE;
|
|
|
|
/* If we were only supposed to resume one thread, only wait for
|
|
that thread - if it's still alive. If it died, however - which
|
|
can happen if we're coming from the thread death case below -
|
|
then we need to make sure we restart the other threads. We could
|
|
pick a thread at random or restart all; restarting all is less
|
|
arbitrary. */
|
|
if (!non_stop
|
|
&& !ptid_equal (cont_thread, null_ptid)
|
|
&& !ptid_equal (cont_thread, minus_one_ptid))
|
|
{
|
|
struct thread_info *thread;
|
|
|
|
thread = (struct thread_info *) find_inferior_id (&all_threads,
|
|
cont_thread);
|
|
|
|
/* No stepping, no signal - unless one is pending already, of course. */
|
|
if (thread == NULL)
|
|
{
|
|
struct thread_resume resume_info;
|
|
resume_info.thread = minus_one_ptid;
|
|
resume_info.kind = resume_continue;
|
|
resume_info.sig = 0;
|
|
linux_resume (&resume_info, 1);
|
|
}
|
|
else
|
|
ptid = cont_thread;
|
|
}
|
|
|
|
if (ptid_equal (step_over_bkpt, null_ptid))
|
|
pid = linux_wait_for_event (ptid, &w, options);
|
|
else
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "step_over_bkpt set [%s], doing a blocking wait\n",
|
|
target_pid_to_str (step_over_bkpt));
|
|
pid = linux_wait_for_event (step_over_bkpt, &w, options & ~WNOHANG);
|
|
}
|
|
|
|
if (pid == 0) /* only if TARGET_WNOHANG */
|
|
return null_ptid;
|
|
|
|
event_child = get_thread_lwp (current_inferior);
|
|
|
|
/* If we are waiting for a particular child, and it exited,
|
|
linux_wait_for_event will return its exit status. Similarly if
|
|
the last child exited. If this is not the last child, however,
|
|
do not report it as exited until there is a 'thread exited' response
|
|
available in the remote protocol. Instead, just wait for another event.
|
|
This should be safe, because if the thread crashed we will already
|
|
have reported the termination signal to GDB; that should stop any
|
|
in-progress stepping operations, etc.
|
|
|
|
Report the exit status of the last thread to exit. This matches
|
|
LinuxThreads' behavior. */
|
|
|
|
if (last_thread_of_process_p (current_inferior))
|
|
{
|
|
if (WIFEXITED (w) || WIFSIGNALED (w))
|
|
{
|
|
if (WIFEXITED (w))
|
|
{
|
|
ourstatus->kind = TARGET_WAITKIND_EXITED;
|
|
ourstatus->value.integer = WEXITSTATUS (w);
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"\nChild exited with retcode = %x \n",
|
|
WEXITSTATUS (w));
|
|
}
|
|
else
|
|
{
|
|
ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
|
|
ourstatus->value.sig = target_signal_from_host (WTERMSIG (w));
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"\nChild terminated with signal = %x \n",
|
|
WTERMSIG (w));
|
|
|
|
}
|
|
|
|
return ptid_of (event_child);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (!WIFSTOPPED (w))
|
|
goto retry;
|
|
}
|
|
|
|
/* If this event was not handled before, and is not a SIGTRAP, we
|
|
report it. SIGILL and SIGSEGV are also treated as traps in case
|
|
a breakpoint is inserted at the current PC. If this target does
|
|
not support internal breakpoints at all, we also report the
|
|
SIGTRAP without further processing; it's of no concern to us. */
|
|
maybe_internal_trap
|
|
= (supports_breakpoints ()
|
|
&& (WSTOPSIG (w) == SIGTRAP
|
|
|| ((WSTOPSIG (w) == SIGILL
|
|
|| WSTOPSIG (w) == SIGSEGV)
|
|
&& (*the_low_target.breakpoint_at) (event_child->stop_pc))));
|
|
|
|
if (maybe_internal_trap)
|
|
{
|
|
/* Handle anything that requires bookkeeping before deciding to
|
|
report the event or continue waiting. */
|
|
|
|
/* First check if we can explain the SIGTRAP with an internal
|
|
breakpoint, or if we should possibly report the event to GDB.
|
|
Do this before anything that may remove or insert a
|
|
breakpoint. */
|
|
bp_explains_trap = breakpoint_inserted_here (event_child->stop_pc);
|
|
|
|
/* We have a SIGTRAP, possibly a step-over dance has just
|
|
finished. If so, tweak the state machine accordingly,
|
|
reinsert breakpoints and delete any reinsert (software
|
|
single-step) breakpoints. */
|
|
step_over_finished = finish_step_over (event_child);
|
|
|
|
/* Now invoke the callbacks of any internal breakpoints there. */
|
|
check_breakpoints (event_child->stop_pc);
|
|
|
|
/* Handle tracepoint data collecting. This may overflow the
|
|
trace buffer, and cause a tracing stop, removing
|
|
breakpoints. */
|
|
trace_event = handle_tracepoints (event_child);
|
|
|
|
if (bp_explains_trap)
|
|
{
|
|
/* If we stepped or ran into an internal breakpoint, we've
|
|
already handled it. So next time we resume (from this
|
|
PC), we should step over it. */
|
|
if (debug_threads)
|
|
fprintf (stderr, "Hit a gdbserver breakpoint.\n");
|
|
|
|
if (breakpoint_here (event_child->stop_pc))
|
|
event_child->need_step_over = 1;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* We have some other signal, possibly a step-over dance was in
|
|
progress, and it should be cancelled too. */
|
|
step_over_finished = finish_step_over (event_child);
|
|
}
|
|
|
|
/* We have all the data we need. Either report the event to GDB, or
|
|
resume threads and keep waiting for more. */
|
|
|
|
/* If we're collecting a fast tracepoint, finish the collection and
|
|
move out of the jump pad before delivering a signal. See
|
|
linux_stabilize_threads. */
|
|
|
|
if (WIFSTOPPED (w)
|
|
&& WSTOPSIG (w) != SIGTRAP
|
|
&& supports_fast_tracepoints ()
|
|
&& in_process_agent_loaded ())
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"Got signal %d for LWP %ld. Check if we need "
|
|
"to defer or adjust it.\n",
|
|
WSTOPSIG (w), lwpid_of (event_child));
|
|
|
|
/* Allow debugging the jump pad itself. */
|
|
if (current_inferior->last_resume_kind != resume_step
|
|
&& maybe_move_out_of_jump_pad (event_child, &w))
|
|
{
|
|
enqueue_one_deferred_signal (event_child, &w);
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"Signal %d for LWP %ld deferred (in jump pad)\n",
|
|
WSTOPSIG (w), lwpid_of (event_child));
|
|
|
|
linux_resume_one_lwp (event_child, 0, 0, NULL);
|
|
goto retry;
|
|
}
|
|
}
|
|
|
|
if (event_child->collecting_fast_tracepoint)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "\
|
|
LWP %ld was trying to move out of the jump pad (%d). \
|
|
Check if we're already there.\n",
|
|
lwpid_of (event_child),
|
|
event_child->collecting_fast_tracepoint);
|
|
|
|
trace_event = 1;
|
|
|
|
event_child->collecting_fast_tracepoint
|
|
= linux_fast_tracepoint_collecting (event_child, NULL);
|
|
|
|
if (event_child->collecting_fast_tracepoint != 1)
|
|
{
|
|
/* No longer need this breakpoint. */
|
|
if (event_child->exit_jump_pad_bkpt != NULL)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"No longer need exit-jump-pad bkpt; removing it."
|
|
"stopping all threads momentarily.\n");
|
|
|
|
/* Other running threads could hit this breakpoint.
|
|
We don't handle moribund locations like GDB does,
|
|
instead we always pause all threads when removing
|
|
breakpoints, so that any step-over or
|
|
decr_pc_after_break adjustment is always taken
|
|
care of while the breakpoint is still
|
|
inserted. */
|
|
stop_all_lwps (1, event_child);
|
|
cancel_breakpoints ();
|
|
|
|
delete_breakpoint (event_child->exit_jump_pad_bkpt);
|
|
event_child->exit_jump_pad_bkpt = NULL;
|
|
|
|
unstop_all_lwps (1, event_child);
|
|
|
|
gdb_assert (event_child->suspended >= 0);
|
|
}
|
|
}
|
|
|
|
if (event_child->collecting_fast_tracepoint == 0)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"fast tracepoint finished "
|
|
"collecting successfully.\n");
|
|
|
|
/* We may have a deferred signal to report. */
|
|
if (dequeue_one_deferred_signal (event_child, &w))
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "dequeued one signal.\n");
|
|
}
|
|
else
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "no deferred signals.\n");
|
|
|
|
if (stabilizing_threads)
|
|
{
|
|
ourstatus->kind = TARGET_WAITKIND_STOPPED;
|
|
ourstatus->value.sig = TARGET_SIGNAL_0;
|
|
return ptid_of (event_child);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Check whether GDB would be interested in this event. */
|
|
|
|
/* If GDB is not interested in this signal, don't stop other
|
|
threads, and don't report it to GDB. Just resume the inferior
|
|
right away. We do this for threading-related signals as well as
|
|
any that GDB specifically requested we ignore. But never ignore
|
|
SIGSTOP if we sent it ourselves, and do not ignore signals when
|
|
stepping - they may require special handling to skip the signal
|
|
handler. */
|
|
/* FIXME drow/2002-06-09: Get signal numbers from the inferior's
|
|
thread library? */
|
|
if (WIFSTOPPED (w)
|
|
&& current_inferior->last_resume_kind != resume_step
|
|
&& (
|
|
#if defined (USE_THREAD_DB) && !defined (__ANDROID__)
|
|
(current_process ()->private->thread_db != NULL
|
|
&& (WSTOPSIG (w) == __SIGRTMIN
|
|
|| WSTOPSIG (w) == __SIGRTMIN + 1))
|
|
||
|
|
#endif
|
|
(pass_signals[target_signal_from_host (WSTOPSIG (w))]
|
|
&& !(WSTOPSIG (w) == SIGSTOP
|
|
&& current_inferior->last_resume_kind == resume_stop))))
|
|
{
|
|
siginfo_t info, *info_p;
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr, "Ignored signal %d for LWP %ld.\n",
|
|
WSTOPSIG (w), lwpid_of (event_child));
|
|
|
|
if (ptrace (PTRACE_GETSIGINFO, lwpid_of (event_child), 0, &info) == 0)
|
|
info_p = &info;
|
|
else
|
|
info_p = NULL;
|
|
linux_resume_one_lwp (event_child, event_child->stepping,
|
|
WSTOPSIG (w), info_p);
|
|
goto retry;
|
|
}
|
|
|
|
/* If GDB wanted this thread to single step, we always want to
|
|
report the SIGTRAP, and let GDB handle it. Watchpoints should
|
|
always be reported. So should signals we can't explain. A
|
|
SIGTRAP we can't explain could be a GDB breakpoint --- we may or
|
|
not support Z0 breakpoints. If we do, we're be able to handle
|
|
GDB breakpoints on top of internal breakpoints, by handling the
|
|
internal breakpoint and still reporting the event to GDB. If we
|
|
don't, we're out of luck, GDB won't see the breakpoint hit. */
|
|
report_to_gdb = (!maybe_internal_trap
|
|
|| current_inferior->last_resume_kind == resume_step
|
|
|| event_child->stopped_by_watchpoint
|
|
|| (!step_over_finished
|
|
&& !bp_explains_trap && !trace_event)
|
|
|| gdb_breakpoint_here (event_child->stop_pc));
|
|
|
|
/* We found no reason GDB would want us to stop. We either hit one
|
|
of our own breakpoints, or finished an internal step GDB
|
|
shouldn't know about. */
|
|
if (!report_to_gdb)
|
|
{
|
|
if (debug_threads)
|
|
{
|
|
if (bp_explains_trap)
|
|
fprintf (stderr, "Hit a gdbserver breakpoint.\n");
|
|
if (step_over_finished)
|
|
fprintf (stderr, "Step-over finished.\n");
|
|
if (trace_event)
|
|
fprintf (stderr, "Tracepoint event.\n");
|
|
}
|
|
|
|
/* We're not reporting this breakpoint to GDB, so apply the
|
|
decr_pc_after_break adjustment to the inferior's regcache
|
|
ourselves. */
|
|
|
|
if (the_low_target.set_pc != NULL)
|
|
{
|
|
struct regcache *regcache
|
|
= get_thread_regcache (get_lwp_thread (event_child), 1);
|
|
(*the_low_target.set_pc) (regcache, event_child->stop_pc);
|
|
}
|
|
|
|
/* We may have finished stepping over a breakpoint. If so,
|
|
we've stopped and suspended all LWPs momentarily except the
|
|
stepping one. This is where we resume them all again. We're
|
|
going to keep waiting, so use proceed, which handles stepping
|
|
over the next breakpoint. */
|
|
if (debug_threads)
|
|
fprintf (stderr, "proceeding all threads.\n");
|
|
|
|
if (step_over_finished)
|
|
unsuspend_all_lwps (event_child);
|
|
|
|
proceed_all_lwps ();
|
|
goto retry;
|
|
}
|
|
|
|
if (debug_threads)
|
|
{
|
|
if (current_inferior->last_resume_kind == resume_step)
|
|
fprintf (stderr, "GDB wanted to single-step, reporting event.\n");
|
|
if (event_child->stopped_by_watchpoint)
|
|
fprintf (stderr, "Stopped by watchpoint.\n");
|
|
if (gdb_breakpoint_here (event_child->stop_pc))
|
|
fprintf (stderr, "Stopped by GDB breakpoint.\n");
|
|
if (debug_threads)
|
|
fprintf (stderr, "Hit a non-gdbserver trap event.\n");
|
|
}
|
|
|
|
/* Alright, we're going to report a stop. */
|
|
|
|
if (!non_stop && !stabilizing_threads)
|
|
{
|
|
/* In all-stop, stop all threads. */
|
|
stop_all_lwps (0, NULL);
|
|
|
|
/* If we're not waiting for a specific LWP, choose an event LWP
|
|
from among those that have had events. Giving equal priority
|
|
to all LWPs that have had events helps prevent
|
|
starvation. */
|
|
if (ptid_equal (ptid, minus_one_ptid))
|
|
{
|
|
event_child->status_pending_p = 1;
|
|
event_child->status_pending = w;
|
|
|
|
select_event_lwp (&event_child);
|
|
|
|
event_child->status_pending_p = 0;
|
|
w = event_child->status_pending;
|
|
}
|
|
|
|
/* Now that we've selected our final event LWP, cancel any
|
|
breakpoints in other LWPs that have hit a GDB breakpoint.
|
|
See the comment in cancel_breakpoints_callback to find out
|
|
why. */
|
|
find_inferior (&all_lwps, cancel_breakpoints_callback, event_child);
|
|
|
|
/* Stabilize threads (move out of jump pads). */
|
|
stabilize_threads ();
|
|
}
|
|
else
|
|
{
|
|
/* If we just finished a step-over, then all threads had been
|
|
momentarily paused. In all-stop, that's fine, we want
|
|
threads stopped by now anyway. In non-stop, we need to
|
|
re-resume threads that GDB wanted to be running. */
|
|
if (step_over_finished)
|
|
unstop_all_lwps (1, event_child);
|
|
}
|
|
|
|
ourstatus->kind = TARGET_WAITKIND_STOPPED;
|
|
|
|
if (current_inferior->last_resume_kind == resume_stop
|
|
&& WSTOPSIG (w) == SIGSTOP)
|
|
{
|
|
/* A thread that has been requested to stop by GDB with vCont;t,
|
|
and it stopped cleanly, so report as SIG0. The use of
|
|
SIGSTOP is an implementation detail. */
|
|
ourstatus->value.sig = TARGET_SIGNAL_0;
|
|
}
|
|
else if (current_inferior->last_resume_kind == resume_stop
|
|
&& WSTOPSIG (w) != SIGSTOP)
|
|
{
|
|
/* A thread that has been requested to stop by GDB with vCont;t,
|
|
but, it stopped for other reasons. */
|
|
ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
|
|
}
|
|
else
|
|
{
|
|
ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
|
|
}
|
|
|
|
gdb_assert (ptid_equal (step_over_bkpt, null_ptid));
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr, "linux_wait ret = %s, %d, %d\n",
|
|
target_pid_to_str (ptid_of (event_child)),
|
|
ourstatus->kind,
|
|
ourstatus->value.sig);
|
|
|
|
return ptid_of (event_child);
|
|
}
|
|
|
|
/* Get rid of any pending event in the pipe. */
|
|
static void
|
|
async_file_flush (void)
|
|
{
|
|
int ret;
|
|
char buf;
|
|
|
|
do
|
|
ret = read (linux_event_pipe[0], &buf, 1);
|
|
while (ret >= 0 || (ret == -1 && errno == EINTR));
|
|
}
|
|
|
|
/* Put something in the pipe, so the event loop wakes up. */
|
|
static void
|
|
async_file_mark (void)
|
|
{
|
|
int ret;
|
|
|
|
async_file_flush ();
|
|
|
|
do
|
|
ret = write (linux_event_pipe[1], "+", 1);
|
|
while (ret == 0 || (ret == -1 && errno == EINTR));
|
|
|
|
/* Ignore EAGAIN. If the pipe is full, the event loop will already
|
|
be awakened anyway. */
|
|
}
|
|
|
|
static ptid_t
|
|
linux_wait (ptid_t ptid,
|
|
struct target_waitstatus *ourstatus, int target_options)
|
|
{
|
|
ptid_t event_ptid;
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr, "linux_wait: [%s]\n", target_pid_to_str (ptid));
|
|
|
|
/* Flush the async file first. */
|
|
if (target_is_async_p ())
|
|
async_file_flush ();
|
|
|
|
event_ptid = linux_wait_1 (ptid, ourstatus, target_options);
|
|
|
|
/* If at least one stop was reported, there may be more. A single
|
|
SIGCHLD can signal more than one child stop. */
|
|
if (target_is_async_p ()
|
|
&& (target_options & TARGET_WNOHANG) != 0
|
|
&& !ptid_equal (event_ptid, null_ptid))
|
|
async_file_mark ();
|
|
|
|
return event_ptid;
|
|
}
|
|
|
|
/* Send a signal to an LWP. */
|
|
|
|
static int
|
|
kill_lwp (unsigned long lwpid, int signo)
|
|
{
|
|
/* Use tkill, if possible, in case we are using nptl threads. If tkill
|
|
fails, then we are not using nptl threads and we should be using kill. */
|
|
|
|
#ifdef __NR_tkill
|
|
{
|
|
static int tkill_failed;
|
|
|
|
if (!tkill_failed)
|
|
{
|
|
int ret;
|
|
|
|
errno = 0;
|
|
ret = syscall (__NR_tkill, lwpid, signo);
|
|
if (errno != ENOSYS)
|
|
return ret;
|
|
tkill_failed = 1;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
return kill (lwpid, signo);
|
|
}
|
|
|
|
void
|
|
linux_stop_lwp (struct lwp_info *lwp)
|
|
{
|
|
send_sigstop (lwp);
|
|
}
|
|
|
|
static void
|
|
send_sigstop (struct lwp_info *lwp)
|
|
{
|
|
int pid;
|
|
|
|
pid = lwpid_of (lwp);
|
|
|
|
/* If we already have a pending stop signal for this process, don't
|
|
send another. */
|
|
if (lwp->stop_expected)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "Have pending sigstop for lwp %d\n", pid);
|
|
|
|
return;
|
|
}
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr, "Sending sigstop to lwp %d\n", pid);
|
|
|
|
lwp->stop_expected = 1;
|
|
kill_lwp (pid, SIGSTOP);
|
|
}
|
|
|
|
static int
|
|
send_sigstop_callback (struct inferior_list_entry *entry, void *except)
|
|
{
|
|
struct lwp_info *lwp = (struct lwp_info *) entry;
|
|
|
|
/* Ignore EXCEPT. */
|
|
if (lwp == except)
|
|
return 0;
|
|
|
|
if (lwp->stopped)
|
|
return 0;
|
|
|
|
send_sigstop (lwp);
|
|
return 0;
|
|
}
|
|
|
|
/* Increment the suspend count of an LWP, and stop it, if not stopped
|
|
yet. */
|
|
static int
|
|
suspend_and_send_sigstop_callback (struct inferior_list_entry *entry,
|
|
void *except)
|
|
{
|
|
struct lwp_info *lwp = (struct lwp_info *) entry;
|
|
|
|
/* Ignore EXCEPT. */
|
|
if (lwp == except)
|
|
return 0;
|
|
|
|
lwp->suspended++;
|
|
|
|
return send_sigstop_callback (entry, except);
|
|
}
|
|
|
|
static void
|
|
mark_lwp_dead (struct lwp_info *lwp, int wstat)
|
|
{
|
|
/* It's dead, really. */
|
|
lwp->dead = 1;
|
|
|
|
/* Store the exit status for later. */
|
|
lwp->status_pending_p = 1;
|
|
lwp->status_pending = wstat;
|
|
|
|
/* Prevent trying to stop it. */
|
|
lwp->stopped = 1;
|
|
|
|
/* No further stops are expected from a dead lwp. */
|
|
lwp->stop_expected = 0;
|
|
}
|
|
|
|
static void
|
|
wait_for_sigstop (struct inferior_list_entry *entry)
|
|
{
|
|
struct lwp_info *lwp = (struct lwp_info *) entry;
|
|
struct thread_info *saved_inferior;
|
|
int wstat;
|
|
ptid_t saved_tid;
|
|
ptid_t ptid;
|
|
int pid;
|
|
|
|
if (lwp->stopped)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "wait_for_sigstop: LWP %ld already stopped\n",
|
|
lwpid_of (lwp));
|
|
return;
|
|
}
|
|
|
|
saved_inferior = current_inferior;
|
|
if (saved_inferior != NULL)
|
|
saved_tid = ((struct inferior_list_entry *) saved_inferior)->id;
|
|
else
|
|
saved_tid = null_ptid; /* avoid bogus unused warning */
|
|
|
|
ptid = lwp->head.id;
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr, "wait_for_sigstop: pulling one event\n");
|
|
|
|
pid = linux_wait_for_event (ptid, &wstat, __WALL);
|
|
|
|
/* If we stopped with a non-SIGSTOP signal, save it for later
|
|
and record the pending SIGSTOP. If the process exited, just
|
|
return. */
|
|
if (WIFSTOPPED (wstat))
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "LWP %ld stopped with signal %d\n",
|
|
lwpid_of (lwp), WSTOPSIG (wstat));
|
|
|
|
if (WSTOPSIG (wstat) != SIGSTOP)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n",
|
|
lwpid_of (lwp), wstat);
|
|
|
|
lwp->status_pending_p = 1;
|
|
lwp->status_pending = wstat;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "Process %d exited while stopping LWPs\n", pid);
|
|
|
|
lwp = find_lwp_pid (pid_to_ptid (pid));
|
|
if (lwp)
|
|
{
|
|
/* Leave this status pending for the next time we're able to
|
|
report it. In the mean time, we'll report this lwp as
|
|
dead to GDB, so GDB doesn't try to read registers and
|
|
memory from it. This can only happen if this was the
|
|
last thread of the process; otherwise, PID is removed
|
|
from the thread tables before linux_wait_for_event
|
|
returns. */
|
|
mark_lwp_dead (lwp, wstat);
|
|
}
|
|
}
|
|
|
|
if (saved_inferior == NULL || linux_thread_alive (saved_tid))
|
|
current_inferior = saved_inferior;
|
|
else
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "Previously current thread died.\n");
|
|
|
|
if (non_stop)
|
|
{
|
|
/* We can't change the current inferior behind GDB's back,
|
|
otherwise, a subsequent command may apply to the wrong
|
|
process. */
|
|
current_inferior = NULL;
|
|
}
|
|
else
|
|
{
|
|
/* Set a valid thread as current. */
|
|
set_desired_inferior (0);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Returns true if LWP ENTRY is stopped in a jump pad, and we can't
|
|
move it out, because we need to report the stop event to GDB. For
|
|
example, if the user puts a breakpoint in the jump pad, it's
|
|
because she wants to debug it. */
|
|
|
|
static int
|
|
stuck_in_jump_pad_callback (struct inferior_list_entry *entry, void *data)
|
|
{
|
|
struct lwp_info *lwp = (struct lwp_info *) entry;
|
|
struct thread_info *thread = get_lwp_thread (lwp);
|
|
|
|
gdb_assert (lwp->suspended == 0);
|
|
gdb_assert (lwp->stopped);
|
|
|
|
/* Allow debugging the jump pad, gdb_collect, etc.. */
|
|
return (supports_fast_tracepoints ()
|
|
&& in_process_agent_loaded ()
|
|
&& (gdb_breakpoint_here (lwp->stop_pc)
|
|
|| lwp->stopped_by_watchpoint
|
|
|| thread->last_resume_kind == resume_step)
|
|
&& linux_fast_tracepoint_collecting (lwp, NULL));
|
|
}
|
|
|
|
static void
|
|
move_out_of_jump_pad_callback (struct inferior_list_entry *entry)
|
|
{
|
|
struct lwp_info *lwp = (struct lwp_info *) entry;
|
|
struct thread_info *thread = get_lwp_thread (lwp);
|
|
int *wstat;
|
|
|
|
gdb_assert (lwp->suspended == 0);
|
|
gdb_assert (lwp->stopped);
|
|
|
|
wstat = lwp->status_pending_p ? &lwp->status_pending : NULL;
|
|
|
|
/* Allow debugging the jump pad, gdb_collect, etc. */
|
|
if (!gdb_breakpoint_here (lwp->stop_pc)
|
|
&& !lwp->stopped_by_watchpoint
|
|
&& thread->last_resume_kind != resume_step
|
|
&& maybe_move_out_of_jump_pad (lwp, wstat))
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"LWP %ld needs stabilizing (in jump pad)\n",
|
|
lwpid_of (lwp));
|
|
|
|
if (wstat)
|
|
{
|
|
lwp->status_pending_p = 0;
|
|
enqueue_one_deferred_signal (lwp, wstat);
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"Signal %d for LWP %ld deferred "
|
|
"(in jump pad)\n",
|
|
WSTOPSIG (*wstat), lwpid_of (lwp));
|
|
}
|
|
|
|
linux_resume_one_lwp (lwp, 0, 0, NULL);
|
|
}
|
|
else
|
|
lwp->suspended++;
|
|
}
|
|
|
|
static int
|
|
lwp_running (struct inferior_list_entry *entry, void *data)
|
|
{
|
|
struct lwp_info *lwp = (struct lwp_info *) entry;
|
|
|
|
if (lwp->dead)
|
|
return 0;
|
|
if (lwp->stopped)
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
/* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
|
|
If SUSPEND, then also increase the suspend count of every LWP,
|
|
except EXCEPT. */
|
|
|
|
static void
|
|
stop_all_lwps (int suspend, struct lwp_info *except)
|
|
{
|
|
stopping_threads = 1;
|
|
|
|
if (suspend)
|
|
find_inferior (&all_lwps, suspend_and_send_sigstop_callback, except);
|
|
else
|
|
find_inferior (&all_lwps, send_sigstop_callback, except);
|
|
for_each_inferior (&all_lwps, wait_for_sigstop);
|
|
stopping_threads = 0;
|
|
}
|
|
|
|
/* Resume execution of the inferior process.
|
|
If STEP is nonzero, single-step it.
|
|
If SIGNAL is nonzero, give it that signal. */
|
|
|
|
static void
|
|
linux_resume_one_lwp (struct lwp_info *lwp,
|
|
int step, int signal, siginfo_t *info)
|
|
{
|
|
struct thread_info *saved_inferior;
|
|
int fast_tp_collecting;
|
|
|
|
if (lwp->stopped == 0)
|
|
return;
|
|
|
|
fast_tp_collecting = lwp->collecting_fast_tracepoint;
|
|
|
|
gdb_assert (!stabilizing_threads || fast_tp_collecting);
|
|
|
|
/* Cancel actions that rely on GDB not changing the PC (e.g., the
|
|
user used the "jump" command, or "set $pc = foo"). */
|
|
if (lwp->stop_pc != get_pc (lwp))
|
|
{
|
|
/* Collecting 'while-stepping' actions doesn't make sense
|
|
anymore. */
|
|
release_while_stepping_state_list (get_lwp_thread (lwp));
|
|
}
|
|
|
|
/* If we have pending signals or status, and a new signal, enqueue the
|
|
signal. Also enqueue the signal if we are waiting to reinsert a
|
|
breakpoint; it will be picked up again below. */
|
|
if (signal != 0
|
|
&& (lwp->status_pending_p
|
|
|| lwp->pending_signals != NULL
|
|
|| lwp->bp_reinsert != 0
|
|
|| fast_tp_collecting))
|
|
{
|
|
struct pending_signals *p_sig;
|
|
p_sig = xmalloc (sizeof (*p_sig));
|
|
p_sig->prev = lwp->pending_signals;
|
|
p_sig->signal = signal;
|
|
if (info == NULL)
|
|
memset (&p_sig->info, 0, sizeof (siginfo_t));
|
|
else
|
|
memcpy (&p_sig->info, info, sizeof (siginfo_t));
|
|
lwp->pending_signals = p_sig;
|
|
}
|
|
|
|
if (lwp->status_pending_p)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "Not resuming lwp %ld (%s, signal %d, stop %s);"
|
|
" has pending status\n",
|
|
lwpid_of (lwp), step ? "step" : "continue", signal,
|
|
lwp->stop_expected ? "expected" : "not expected");
|
|
return;
|
|
}
|
|
|
|
saved_inferior = current_inferior;
|
|
current_inferior = get_lwp_thread (lwp);
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
|
|
lwpid_of (lwp), step ? "step" : "continue", signal,
|
|
lwp->stop_expected ? "expected" : "not expected");
|
|
|
|
/* This bit needs some thinking about. If we get a signal that
|
|
we must report while a single-step reinsert is still pending,
|
|
we often end up resuming the thread. It might be better to
|
|
(ew) allow a stack of pending events; then we could be sure that
|
|
the reinsert happened right away and not lose any signals.
|
|
|
|
Making this stack would also shrink the window in which breakpoints are
|
|
uninserted (see comment in linux_wait_for_lwp) but not enough for
|
|
complete correctness, so it won't solve that problem. It may be
|
|
worthwhile just to solve this one, however. */
|
|
if (lwp->bp_reinsert != 0)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, " pending reinsert at 0x%s\n",
|
|
paddress (lwp->bp_reinsert));
|
|
|
|
if (lwp->bp_reinsert != 0 && can_hardware_single_step ())
|
|
{
|
|
if (fast_tp_collecting == 0)
|
|
{
|
|
if (step == 0)
|
|
fprintf (stderr, "BAD - reinserting but not stepping.\n");
|
|
if (lwp->suspended)
|
|
fprintf (stderr, "BAD - reinserting and suspended(%d).\n",
|
|
lwp->suspended);
|
|
}
|
|
|
|
step = 1;
|
|
}
|
|
|
|
/* Postpone any pending signal. It was enqueued above. */
|
|
signal = 0;
|
|
}
|
|
|
|
if (fast_tp_collecting == 1)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "\
|
|
lwp %ld wants to get out of fast tracepoint jump pad (exit-jump-pad-bkpt)\n",
|
|
lwpid_of (lwp));
|
|
|
|
/* Postpone any pending signal. It was enqueued above. */
|
|
signal = 0;
|
|
}
|
|
else if (fast_tp_collecting == 2)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "\
|
|
lwp %ld wants to get out of fast tracepoint jump pad single-stepping\n",
|
|
lwpid_of (lwp));
|
|
|
|
if (can_hardware_single_step ())
|
|
step = 1;
|
|
else
|
|
fatal ("moving out of jump pad single-stepping"
|
|
" not implemented on this target");
|
|
|
|
/* Postpone any pending signal. It was enqueued above. */
|
|
signal = 0;
|
|
}
|
|
|
|
/* If we have while-stepping actions in this thread set it stepping.
|
|
If we have a signal to deliver, it may or may not be set to
|
|
SIG_IGN, we don't know. Assume so, and allow collecting
|
|
while-stepping into a signal handler. A possible smart thing to
|
|
do would be to set an internal breakpoint at the signal return
|
|
address, continue, and carry on catching this while-stepping
|
|
action only when that breakpoint is hit. A future
|
|
enhancement. */
|
|
if (get_lwp_thread (lwp)->while_stepping != NULL
|
|
&& can_hardware_single_step ())
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"lwp %ld has a while-stepping action -> forcing step.\n",
|
|
lwpid_of (lwp));
|
|
step = 1;
|
|
}
|
|
|
|
if (debug_threads && the_low_target.get_pc != NULL)
|
|
{
|
|
struct regcache *regcache = get_thread_regcache (current_inferior, 1);
|
|
CORE_ADDR pc = (*the_low_target.get_pc) (regcache);
|
|
fprintf (stderr, " resuming from pc 0x%lx\n", (long) pc);
|
|
}
|
|
|
|
/* If we have pending signals, consume one unless we are trying to
|
|
reinsert a breakpoint or we're trying to finish a fast tracepoint
|
|
collect. */
|
|
if (lwp->pending_signals != NULL
|
|
&& lwp->bp_reinsert == 0
|
|
&& fast_tp_collecting == 0)
|
|
{
|
|
struct pending_signals **p_sig;
|
|
|
|
p_sig = &lwp->pending_signals;
|
|
while ((*p_sig)->prev != NULL)
|
|
p_sig = &(*p_sig)->prev;
|
|
|
|
signal = (*p_sig)->signal;
|
|
if ((*p_sig)->info.si_signo != 0)
|
|
ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &(*p_sig)->info);
|
|
|
|
free (*p_sig);
|
|
*p_sig = NULL;
|
|
}
|
|
|
|
if (the_low_target.prepare_to_resume != NULL)
|
|
the_low_target.prepare_to_resume (lwp);
|
|
|
|
regcache_invalidate_one ((struct inferior_list_entry *)
|
|
get_lwp_thread (lwp));
|
|
errno = 0;
|
|
lwp->stopped = 0;
|
|
lwp->stopped_by_watchpoint = 0;
|
|
lwp->stepping = step;
|
|
ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (lwp), 0,
|
|
/* Coerce to a uintptr_t first to avoid potential gcc warning
|
|
of coercing an 8 byte integer to a 4 byte pointer. */
|
|
(PTRACE_ARG4_TYPE) (uintptr_t) signal);
|
|
|
|
current_inferior = saved_inferior;
|
|
if (errno)
|
|
{
|
|
/* ESRCH from ptrace either means that the thread was already
|
|
running (an error) or that it is gone (a race condition). If
|
|
it's gone, we will get a notification the next time we wait,
|
|
so we can ignore the error. We could differentiate these
|
|
two, but it's tricky without waiting; the thread still exists
|
|
as a zombie, so sending it signal 0 would succeed. So just
|
|
ignore ESRCH. */
|
|
if (errno == ESRCH)
|
|
return;
|
|
|
|
perror_with_name ("ptrace");
|
|
}
|
|
}
|
|
|
|
struct thread_resume_array
|
|
{
|
|
struct thread_resume *resume;
|
|
size_t n;
|
|
};
|
|
|
|
/* This function is called once per thread. We look up the thread
|
|
in RESUME_PTR, and mark the thread with a pointer to the appropriate
|
|
resume request.
|
|
|
|
This algorithm is O(threads * resume elements), but resume elements
|
|
is small (and will remain small at least until GDB supports thread
|
|
suspension). */
|
|
static int
|
|
linux_set_resume_request (struct inferior_list_entry *entry, void *arg)
|
|
{
|
|
struct lwp_info *lwp;
|
|
struct thread_info *thread;
|
|
int ndx;
|
|
struct thread_resume_array *r;
|
|
|
|
thread = (struct thread_info *) entry;
|
|
lwp = get_thread_lwp (thread);
|
|
r = arg;
|
|
|
|
for (ndx = 0; ndx < r->n; ndx++)
|
|
{
|
|
ptid_t ptid = r->resume[ndx].thread;
|
|
if (ptid_equal (ptid, minus_one_ptid)
|
|
|| ptid_equal (ptid, entry->id)
|
|
|| (ptid_is_pid (ptid)
|
|
&& (ptid_get_pid (ptid) == pid_of (lwp)))
|
|
|| (ptid_get_lwp (ptid) == -1
|
|
&& (ptid_get_pid (ptid) == pid_of (lwp))))
|
|
{
|
|
if (r->resume[ndx].kind == resume_stop
|
|
&& thread->last_resume_kind == resume_stop)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "already %s LWP %ld at GDB's request\n",
|
|
thread->last_status.kind == TARGET_WAITKIND_STOPPED
|
|
? "stopped"
|
|
: "stopping",
|
|
lwpid_of (lwp));
|
|
|
|
continue;
|
|
}
|
|
|
|
lwp->resume = &r->resume[ndx];
|
|
thread->last_resume_kind = lwp->resume->kind;
|
|
|
|
/* If we had a deferred signal to report, dequeue one now.
|
|
This can happen if LWP gets more than one signal while
|
|
trying to get out of a jump pad. */
|
|
if (lwp->stopped
|
|
&& !lwp->status_pending_p
|
|
&& dequeue_one_deferred_signal (lwp, &lwp->status_pending))
|
|
{
|
|
lwp->status_pending_p = 1;
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"Dequeueing deferred signal %d for LWP %ld, "
|
|
"leaving status pending.\n",
|
|
WSTOPSIG (lwp->status_pending), lwpid_of (lwp));
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/* No resume action for this thread. */
|
|
lwp->resume = NULL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/* Set *FLAG_P if this lwp has an interesting status pending. */
|
|
static int
|
|
resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p)
|
|
{
|
|
struct lwp_info *lwp = (struct lwp_info *) entry;
|
|
|
|
/* LWPs which will not be resumed are not interesting, because
|
|
we might not wait for them next time through linux_wait. */
|
|
if (lwp->resume == NULL)
|
|
return 0;
|
|
|
|
if (lwp->status_pending_p)
|
|
* (int *) flag_p = 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Return 1 if this lwp that GDB wants running is stopped at an
|
|
internal breakpoint that we need to step over. It assumes that any
|
|
required STOP_PC adjustment has already been propagated to the
|
|
inferior's regcache. */
|
|
|
|
static int
|
|
need_step_over_p (struct inferior_list_entry *entry, void *dummy)
|
|
{
|
|
struct lwp_info *lwp = (struct lwp_info *) entry;
|
|
struct thread_info *thread;
|
|
struct thread_info *saved_inferior;
|
|
CORE_ADDR pc;
|
|
|
|
/* LWPs which will not be resumed are not interesting, because we
|
|
might not wait for them next time through linux_wait. */
|
|
|
|
if (!lwp->stopped)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"Need step over [LWP %ld]? Ignoring, not stopped\n",
|
|
lwpid_of (lwp));
|
|
return 0;
|
|
}
|
|
|
|
thread = get_lwp_thread (lwp);
|
|
|
|
if (thread->last_resume_kind == resume_stop)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"Need step over [LWP %ld]? Ignoring, should remain stopped\n",
|
|
lwpid_of (lwp));
|
|
return 0;
|
|
}
|
|
|
|
gdb_assert (lwp->suspended >= 0);
|
|
|
|
if (lwp->suspended)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"Need step over [LWP %ld]? Ignoring, suspended\n",
|
|
lwpid_of (lwp));
|
|
return 0;
|
|
}
|
|
|
|
if (!lwp->need_step_over)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"Need step over [LWP %ld]? No\n", lwpid_of (lwp));
|
|
}
|
|
|
|
if (lwp->status_pending_p)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"Need step over [LWP %ld]? Ignoring, has pending status.\n",
|
|
lwpid_of (lwp));
|
|
return 0;
|
|
}
|
|
|
|
/* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
|
|
or we have. */
|
|
pc = get_pc (lwp);
|
|
|
|
/* If the PC has changed since we stopped, then don't do anything,
|
|
and let the breakpoint/tracepoint be hit. This happens if, for
|
|
instance, GDB handled the decr_pc_after_break subtraction itself,
|
|
GDB is OOL stepping this thread, or the user has issued a "jump"
|
|
command, or poked thread's registers herself. */
|
|
if (pc != lwp->stop_pc)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"Need step over [LWP %ld]? Cancelling, PC was changed. "
|
|
"Old stop_pc was 0x%s, PC is now 0x%s\n",
|
|
lwpid_of (lwp), paddress (lwp->stop_pc), paddress (pc));
|
|
|
|
lwp->need_step_over = 0;
|
|
return 0;
|
|
}
|
|
|
|
saved_inferior = current_inferior;
|
|
current_inferior = thread;
|
|
|
|
/* We can only step over breakpoints we know about. */
|
|
if (breakpoint_here (pc) || fast_tracepoint_jump_here (pc))
|
|
{
|
|
/* Don't step over a breakpoint that GDB expects to hit
|
|
though. */
|
|
if (gdb_breakpoint_here (pc))
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"Need step over [LWP %ld]? yes, but found"
|
|
" GDB breakpoint at 0x%s; skipping step over\n",
|
|
lwpid_of (lwp), paddress (pc));
|
|
|
|
current_inferior = saved_inferior;
|
|
return 0;
|
|
}
|
|
else
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"Need step over [LWP %ld]? yes, "
|
|
"found breakpoint at 0x%s\n",
|
|
lwpid_of (lwp), paddress (pc));
|
|
|
|
/* We've found an lwp that needs stepping over --- return 1 so
|
|
that find_inferior stops looking. */
|
|
current_inferior = saved_inferior;
|
|
|
|
/* If the step over is cancelled, this is set again. */
|
|
lwp->need_step_over = 0;
|
|
return 1;
|
|
}
|
|
}
|
|
|
|
current_inferior = saved_inferior;
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"Need step over [LWP %ld]? No, no breakpoint found at 0x%s\n",
|
|
lwpid_of (lwp), paddress (pc));
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Start a step-over operation on LWP. When LWP stopped at a
|
|
breakpoint, to make progress, we need to remove the breakpoint out
|
|
of the way. If we let other threads run while we do that, they may
|
|
pass by the breakpoint location and miss hitting it. To avoid
|
|
that, a step-over momentarily stops all threads while LWP is
|
|
single-stepped while the breakpoint is temporarily uninserted from
|
|
the inferior. When the single-step finishes, we reinsert the
|
|
breakpoint, and let all threads that are supposed to be running,
|
|
run again.
|
|
|
|
On targets that don't support hardware single-step, we don't
|
|
currently support full software single-stepping. Instead, we only
|
|
support stepping over the thread event breakpoint, by asking the
|
|
low target where to place a reinsert breakpoint. Since this
|
|
routine assumes the breakpoint being stepped over is a thread event
|
|
breakpoint, it usually assumes the return address of the current
|
|
function is a good enough place to set the reinsert breakpoint. */
|
|
|
|
static int
|
|
start_step_over (struct lwp_info *lwp)
|
|
{
|
|
struct thread_info *saved_inferior;
|
|
CORE_ADDR pc;
|
|
int step;
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"Starting step-over on LWP %ld. Stopping all threads\n",
|
|
lwpid_of (lwp));
|
|
|
|
stop_all_lwps (1, lwp);
|
|
gdb_assert (lwp->suspended == 0);
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr, "Done stopping all threads for step-over.\n");
|
|
|
|
/* Note, we should always reach here with an already adjusted PC,
|
|
either by GDB (if we're resuming due to GDB's request), or by our
|
|
caller, if we just finished handling an internal breakpoint GDB
|
|
shouldn't care about. */
|
|
pc = get_pc (lwp);
|
|
|
|
saved_inferior = current_inferior;
|
|
current_inferior = get_lwp_thread (lwp);
|
|
|
|
lwp->bp_reinsert = pc;
|
|
uninsert_breakpoints_at (pc);
|
|
uninsert_fast_tracepoint_jumps_at (pc);
|
|
|
|
if (can_hardware_single_step ())
|
|
{
|
|
step = 1;
|
|
}
|
|
else
|
|
{
|
|
CORE_ADDR raddr = (*the_low_target.breakpoint_reinsert_addr) ();
|
|
set_reinsert_breakpoint (raddr);
|
|
step = 0;
|
|
}
|
|
|
|
current_inferior = saved_inferior;
|
|
|
|
linux_resume_one_lwp (lwp, step, 0, NULL);
|
|
|
|
/* Require next event from this LWP. */
|
|
step_over_bkpt = lwp->head.id;
|
|
return 1;
|
|
}
|
|
|
|
/* Finish a step-over. Reinsert the breakpoint we had uninserted in
|
|
start_step_over, if still there, and delete any reinsert
|
|
breakpoints we've set, on non hardware single-step targets. */
|
|
|
|
static int
|
|
finish_step_over (struct lwp_info *lwp)
|
|
{
|
|
if (lwp->bp_reinsert != 0)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "Finished step over.\n");
|
|
|
|
/* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
|
|
may be no breakpoint to reinsert there by now. */
|
|
reinsert_breakpoints_at (lwp->bp_reinsert);
|
|
reinsert_fast_tracepoint_jumps_at (lwp->bp_reinsert);
|
|
|
|
lwp->bp_reinsert = 0;
|
|
|
|
/* Delete any software-single-step reinsert breakpoints. No
|
|
longer needed. We don't have to worry about other threads
|
|
hitting this trap, and later not being able to explain it,
|
|
because we were stepping over a breakpoint, and we hold all
|
|
threads but LWP stopped while doing that. */
|
|
if (!can_hardware_single_step ())
|
|
delete_reinsert_breakpoints ();
|
|
|
|
step_over_bkpt = null_ptid;
|
|
return 1;
|
|
}
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
/* This function is called once per thread. We check the thread's resume
|
|
request, which will tell us whether to resume, step, or leave the thread
|
|
stopped; and what signal, if any, it should be sent.
|
|
|
|
For threads which we aren't explicitly told otherwise, we preserve
|
|
the stepping flag; this is used for stepping over gdbserver-placed
|
|
breakpoints.
|
|
|
|
If pending_flags was set in any thread, we queue any needed
|
|
signals, since we won't actually resume. We already have a pending
|
|
event to report, so we don't need to preserve any step requests;
|
|
they should be re-issued if necessary. */
|
|
|
|
static int
|
|
linux_resume_one_thread (struct inferior_list_entry *entry, void *arg)
|
|
{
|
|
struct lwp_info *lwp;
|
|
struct thread_info *thread;
|
|
int step;
|
|
int leave_all_stopped = * (int *) arg;
|
|
int leave_pending;
|
|
|
|
thread = (struct thread_info *) entry;
|
|
lwp = get_thread_lwp (thread);
|
|
|
|
if (lwp->resume == NULL)
|
|
return 0;
|
|
|
|
if (lwp->resume->kind == resume_stop)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "resume_stop request for LWP %ld\n", lwpid_of (lwp));
|
|
|
|
if (!lwp->stopped)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "stopping LWP %ld\n", lwpid_of (lwp));
|
|
|
|
/* Stop the thread, and wait for the event asynchronously,
|
|
through the event loop. */
|
|
send_sigstop (lwp);
|
|
}
|
|
else
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "already stopped LWP %ld\n",
|
|
lwpid_of (lwp));
|
|
|
|
/* The LWP may have been stopped in an internal event that
|
|
was not meant to be notified back to GDB (e.g., gdbserver
|
|
breakpoint), so we should be reporting a stop event in
|
|
this case too. */
|
|
|
|
/* If the thread already has a pending SIGSTOP, this is a
|
|
no-op. Otherwise, something later will presumably resume
|
|
the thread and this will cause it to cancel any pending
|
|
operation, due to last_resume_kind == resume_stop. If
|
|
the thread already has a pending status to report, we
|
|
will still report it the next time we wait - see
|
|
status_pending_p_callback. */
|
|
|
|
/* If we already have a pending signal to report, then
|
|
there's no need to queue a SIGSTOP, as this means we're
|
|
midway through moving the LWP out of the jumppad, and we
|
|
will report the pending signal as soon as that is
|
|
finished. */
|
|
if (lwp->pending_signals_to_report == NULL)
|
|
send_sigstop (lwp);
|
|
}
|
|
|
|
/* For stop requests, we're done. */
|
|
lwp->resume = NULL;
|
|
thread->last_status.kind = TARGET_WAITKIND_IGNORE;
|
|
return 0;
|
|
}
|
|
|
|
/* If this thread which is about to be resumed has a pending status,
|
|
then don't resume any threads - we can just report the pending
|
|
status. Make sure to queue any signals that would otherwise be
|
|
sent. In all-stop mode, we do this decision based on if *any*
|
|
thread has a pending status. If there's a thread that needs the
|
|
step-over-breakpoint dance, then don't resume any other thread
|
|
but that particular one. */
|
|
leave_pending = (lwp->status_pending_p || leave_all_stopped);
|
|
|
|
if (!leave_pending)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "resuming LWP %ld\n", lwpid_of (lwp));
|
|
|
|
step = (lwp->resume->kind == resume_step);
|
|
linux_resume_one_lwp (lwp, step, lwp->resume->sig, NULL);
|
|
}
|
|
else
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "leaving LWP %ld stopped\n", lwpid_of (lwp));
|
|
|
|
/* If we have a new signal, enqueue the signal. */
|
|
if (lwp->resume->sig != 0)
|
|
{
|
|
struct pending_signals *p_sig;
|
|
p_sig = xmalloc (sizeof (*p_sig));
|
|
p_sig->prev = lwp->pending_signals;
|
|
p_sig->signal = lwp->resume->sig;
|
|
memset (&p_sig->info, 0, sizeof (siginfo_t));
|
|
|
|
/* If this is the same signal we were previously stopped by,
|
|
make sure to queue its siginfo. We can ignore the return
|
|
value of ptrace; if it fails, we'll skip
|
|
PTRACE_SETSIGINFO. */
|
|
if (WIFSTOPPED (lwp->last_status)
|
|
&& WSTOPSIG (lwp->last_status) == lwp->resume->sig)
|
|
ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info);
|
|
|
|
lwp->pending_signals = p_sig;
|
|
}
|
|
}
|
|
|
|
thread->last_status.kind = TARGET_WAITKIND_IGNORE;
|
|
lwp->resume = NULL;
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
linux_resume (struct thread_resume *resume_info, size_t n)
|
|
{
|
|
struct thread_resume_array array = { resume_info, n };
|
|
struct lwp_info *need_step_over = NULL;
|
|
int any_pending;
|
|
int leave_all_stopped;
|
|
|
|
find_inferior (&all_threads, linux_set_resume_request, &array);
|
|
|
|
/* If there is a thread which would otherwise be resumed, which has
|
|
a pending status, then don't resume any threads - we can just
|
|
report the pending status. Make sure to queue any signals that
|
|
would otherwise be sent. In non-stop mode, we'll apply this
|
|
logic to each thread individually. We consume all pending events
|
|
before considering to start a step-over (in all-stop). */
|
|
any_pending = 0;
|
|
if (!non_stop)
|
|
find_inferior (&all_lwps, resume_status_pending_p, &any_pending);
|
|
|
|
/* If there is a thread which would otherwise be resumed, which is
|
|
stopped at a breakpoint that needs stepping over, then don't
|
|
resume any threads - have it step over the breakpoint with all
|
|
other threads stopped, then resume all threads again. Make sure
|
|
to queue any signals that would otherwise be delivered or
|
|
queued. */
|
|
if (!any_pending && supports_breakpoints ())
|
|
need_step_over
|
|
= (struct lwp_info *) find_inferior (&all_lwps,
|
|
need_step_over_p, NULL);
|
|
|
|
leave_all_stopped = (need_step_over != NULL || any_pending);
|
|
|
|
if (debug_threads)
|
|
{
|
|
if (need_step_over != NULL)
|
|
fprintf (stderr, "Not resuming all, need step over\n");
|
|
else if (any_pending)
|
|
fprintf (stderr,
|
|
"Not resuming, all-stop and found "
|
|
"an LWP with pending status\n");
|
|
else
|
|
fprintf (stderr, "Resuming, no pending status or step over needed\n");
|
|
}
|
|
|
|
/* Even if we're leaving threads stopped, queue all signals we'd
|
|
otherwise deliver. */
|
|
find_inferior (&all_threads, linux_resume_one_thread, &leave_all_stopped);
|
|
|
|
if (need_step_over)
|
|
start_step_over (need_step_over);
|
|
}
|
|
|
|
/* This function is called once per thread. We check the thread's
|
|
last resume request, which will tell us whether to resume, step, or
|
|
leave the thread stopped. Any signal the client requested to be
|
|
delivered has already been enqueued at this point.
|
|
|
|
If any thread that GDB wants running is stopped at an internal
|
|
breakpoint that needs stepping over, we start a step-over operation
|
|
on that particular thread, and leave all others stopped. */
|
|
|
|
static int
|
|
proceed_one_lwp (struct inferior_list_entry *entry, void *except)
|
|
{
|
|
struct lwp_info *lwp = (struct lwp_info *) entry;
|
|
struct thread_info *thread;
|
|
int step;
|
|
|
|
if (lwp == except)
|
|
return 0;
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"proceed_one_lwp: lwp %ld\n", lwpid_of (lwp));
|
|
|
|
if (!lwp->stopped)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, " LWP %ld already running\n", lwpid_of (lwp));
|
|
return 0;
|
|
}
|
|
|
|
thread = get_lwp_thread (lwp);
|
|
|
|
if (thread->last_resume_kind == resume_stop
|
|
&& thread->last_status.kind != TARGET_WAITKIND_IGNORE)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, " client wants LWP to remain %ld stopped\n",
|
|
lwpid_of (lwp));
|
|
return 0;
|
|
}
|
|
|
|
if (lwp->status_pending_p)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, " LWP %ld has pending status, leaving stopped\n",
|
|
lwpid_of (lwp));
|
|
return 0;
|
|
}
|
|
|
|
gdb_assert (lwp->suspended >= 0);
|
|
|
|
if (lwp->suspended)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, " LWP %ld is suspended\n", lwpid_of (lwp));
|
|
return 0;
|
|
}
|
|
|
|
if (thread->last_resume_kind == resume_stop
|
|
&& lwp->pending_signals_to_report == NULL
|
|
&& lwp->collecting_fast_tracepoint == 0)
|
|
{
|
|
/* We haven't reported this LWP as stopped yet (otherwise, the
|
|
last_status.kind check above would catch it, and we wouldn't
|
|
reach here. This LWP may have been momentarily paused by a
|
|
stop_all_lwps call while handling for example, another LWP's
|
|
step-over. In that case, the pending expected SIGSTOP signal
|
|
that was queued at vCont;t handling time will have already
|
|
been consumed by wait_for_sigstop, and so we need to requeue
|
|
another one here. Note that if the LWP already has a SIGSTOP
|
|
pending, this is a no-op. */
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr,
|
|
"Client wants LWP %ld to stop. "
|
|
"Making sure it has a SIGSTOP pending\n",
|
|
lwpid_of (lwp));
|
|
|
|
send_sigstop (lwp);
|
|
}
|
|
|
|
step = thread->last_resume_kind == resume_step;
|
|
linux_resume_one_lwp (lwp, step, 0, NULL);
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
unsuspend_and_proceed_one_lwp (struct inferior_list_entry *entry, void *except)
|
|
{
|
|
struct lwp_info *lwp = (struct lwp_info *) entry;
|
|
|
|
if (lwp == except)
|
|
return 0;
|
|
|
|
lwp->suspended--;
|
|
gdb_assert (lwp->suspended >= 0);
|
|
|
|
return proceed_one_lwp (entry, except);
|
|
}
|
|
|
|
/* When we finish a step-over, set threads running again. If there's
|
|
another thread that may need a step-over, now's the time to start
|
|
it. Eventually, we'll move all threads past their breakpoints. */
|
|
|
|
static void
|
|
proceed_all_lwps (void)
|
|
{
|
|
struct lwp_info *need_step_over;
|
|
|
|
/* If there is a thread which would otherwise be resumed, which is
|
|
stopped at a breakpoint that needs stepping over, then don't
|
|
resume any threads - have it step over the breakpoint with all
|
|
other threads stopped, then resume all threads again. */
|
|
|
|
if (supports_breakpoints ())
|
|
{
|
|
need_step_over
|
|
= (struct lwp_info *) find_inferior (&all_lwps,
|
|
need_step_over_p, NULL);
|
|
|
|
if (need_step_over != NULL)
|
|
{
|
|
if (debug_threads)
|
|
fprintf (stderr, "proceed_all_lwps: found "
|
|
"thread %ld needing a step-over\n",
|
|
lwpid_of (need_step_over));
|
|
|
|
start_step_over (need_step_over);
|
|
return;
|
|
}
|
|
}
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr, "Proceeding, no step-over needed\n");
|
|
|
|
find_inferior (&all_lwps, proceed_one_lwp, NULL);
|
|
}
|
|
|
|
/* Stopped LWPs that the client wanted to be running, that don't have
|
|
pending statuses, are set to run again, except for EXCEPT, if not
|
|
NULL. This undoes a stop_all_lwps call. */
|
|
|
|
static void
|
|
unstop_all_lwps (int unsuspend, struct lwp_info *except)
|
|
{
|
|
if (debug_threads)
|
|
{
|
|
if (except)
|
|
fprintf (stderr,
|
|
"unstopping all lwps, except=(LWP %ld)\n", lwpid_of (except));
|
|
else
|
|
fprintf (stderr,
|
|
"unstopping all lwps\n");
|
|
}
|
|
|
|
if (unsuspend)
|
|
find_inferior (&all_lwps, unsuspend_and_proceed_one_lwp, except);
|
|
else
|
|
find_inferior (&all_lwps, proceed_one_lwp, except);
|
|
}
|
|
|
|
#ifdef HAVE_LINUX_USRREGS
|
|
|
|
int
|
|
register_addr (int regnum)
|
|
{
|
|
int addr;
|
|
|
|
if (regnum < 0 || regnum >= the_low_target.num_regs)
|
|
error ("Invalid register number %d.", regnum);
|
|
|
|
addr = the_low_target.regmap[regnum];
|
|
|
|
return addr;
|
|
}
|
|
|
|
/* Fetch one register. */
|
|
static void
|
|
fetch_register (struct regcache *regcache, int regno)
|
|
{
|
|
CORE_ADDR regaddr;
|
|
int i, size;
|
|
char *buf;
|
|
int pid;
|
|
|
|
if (regno >= the_low_target.num_regs)
|
|
return;
|
|
if ((*the_low_target.cannot_fetch_register) (regno))
|
|
return;
|
|
|
|
regaddr = register_addr (regno);
|
|
if (regaddr == -1)
|
|
return;
|
|
|
|
pid = lwpid_of (get_thread_lwp (current_inferior));
|
|
size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
|
|
& - sizeof (PTRACE_XFER_TYPE));
|
|
buf = alloca (size);
|
|
for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
|
|
{
|
|
errno = 0;
|
|
*(PTRACE_XFER_TYPE *) (buf + i) =
|
|
ptrace (PTRACE_PEEKUSER, pid,
|
|
/* Coerce to a uintptr_t first to avoid potential gcc warning
|
|
of coercing an 8 byte integer to a 4 byte pointer. */
|
|
(PTRACE_ARG3_TYPE) (uintptr_t) regaddr, 0);
|
|
regaddr += sizeof (PTRACE_XFER_TYPE);
|
|
if (errno != 0)
|
|
error ("reading register %d: %s", regno, strerror (errno));
|
|
}
|
|
|
|
if (the_low_target.supply_ptrace_register)
|
|
the_low_target.supply_ptrace_register (regcache, regno, buf);
|
|
else
|
|
supply_register (regcache, regno, buf);
|
|
}
|
|
|
|
/* Fetch all registers, or just one, from the child process. */
|
|
static void
|
|
usr_fetch_inferior_registers (struct regcache *regcache, int regno)
|
|
{
|
|
if (regno == -1)
|
|
for (regno = 0; regno < the_low_target.num_regs; regno++)
|
|
fetch_register (regcache, regno);
|
|
else
|
|
fetch_register (regcache, regno);
|
|
}
|
|
|
|
/* Store our register values back into the inferior.
|
|
If REGNO is -1, do this for all registers.
|
|
Otherwise, REGNO specifies which register (so we can save time). */
|
|
static void
|
|
usr_store_inferior_registers (struct regcache *regcache, int regno)
|
|
{
|
|
CORE_ADDR regaddr;
|
|
int i, size;
|
|
char *buf;
|
|
int pid;
|
|
|
|
if (regno >= 0)
|
|
{
|
|
if (regno >= the_low_target.num_regs)
|
|
return;
|
|
|
|
if ((*the_low_target.cannot_store_register) (regno) == 1)
|
|
return;
|
|
|
|
regaddr = register_addr (regno);
|
|
if (regaddr == -1)
|
|
return;
|
|
errno = 0;
|
|
size = (register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1)
|
|
& - sizeof (PTRACE_XFER_TYPE);
|
|
buf = alloca (size);
|
|
memset (buf, 0, size);
|
|
|
|
if (the_low_target.collect_ptrace_register)
|
|
the_low_target.collect_ptrace_register (regcache, regno, buf);
|
|
else
|
|
collect_register (regcache, regno, buf);
|
|
|
|
pid = lwpid_of (get_thread_lwp (current_inferior));
|
|
for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
|
|
{
|
|
errno = 0;
|
|
ptrace (PTRACE_POKEUSER, pid,
|
|
/* Coerce to a uintptr_t first to avoid potential gcc warning
|
|
about coercing an 8 byte integer to a 4 byte pointer. */
|
|
(PTRACE_ARG3_TYPE) (uintptr_t) regaddr,
|
|
(PTRACE_ARG4_TYPE) *(PTRACE_XFER_TYPE *) (buf + i));
|
|
if (errno != 0)
|
|
{
|
|
/* At this point, ESRCH should mean the process is
|
|
already gone, in which case we simply ignore attempts
|
|
to change its registers. See also the related
|
|
comment in linux_resume_one_lwp. */
|
|
if (errno == ESRCH)
|
|
return;
|
|
|
|
if ((*the_low_target.cannot_store_register) (regno) == 0)
|
|
error ("writing register %d: %s", regno, strerror (errno));
|
|
}
|
|
regaddr += sizeof (PTRACE_XFER_TYPE);
|
|
}
|
|
}
|
|
else
|
|
for (regno = 0; regno < the_low_target.num_regs; regno++)
|
|
usr_store_inferior_registers (regcache, regno);
|
|
}
|
|
#endif /* HAVE_LINUX_USRREGS */
|
|
|
|
|
|
|
|
#ifdef HAVE_LINUX_REGSETS
|
|
|
|
static int
|
|
regsets_fetch_inferior_registers (struct regcache *regcache)
|
|
{
|
|
struct regset_info *regset;
|
|
int saw_general_regs = 0;
|
|
int pid;
|
|
struct iovec iov;
|
|
|
|
regset = target_regsets;
|
|
|
|
pid = lwpid_of (get_thread_lwp (current_inferior));
|
|
while (regset->size >= 0)
|
|
{
|
|
void *buf, *data;
|
|
int nt_type, res;
|
|
|
|
if (regset->size == 0 || disabled_regsets[regset - target_regsets])
|
|
{
|
|
regset ++;
|
|
continue;
|
|
}
|
|
|
|
buf = xmalloc (regset->size);
|
|
|
|
nt_type = regset->nt_type;
|
|
if (nt_type)
|
|
{
|
|
iov.iov_base = buf;
|
|
iov.iov_len = regset->size;
|
|
data = (void *) &iov;
|
|
}
|
|
else
|
|
data = buf;
|
|
|
|
#ifndef __sparc__
|
|
res = ptrace (regset->get_request, pid, nt_type, data);
|
|
#else
|
|
res = ptrace (regset->get_request, pid, data, nt_type);
|
|
#endif
|
|
if (res < 0)
|
|
{
|
|
if (errno == EIO)
|
|
{
|
|
/* If we get EIO on a regset, do not try it again for
|
|
this process. */
|
|
disabled_regsets[regset - target_regsets] = 1;
|
|
free (buf);
|
|
continue;
|
|
}
|
|
else
|
|
{
|
|
char s[256];
|
|
sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d",
|
|
pid);
|
|
perror (s);
|
|
}
|
|
}
|
|
else if (regset->type == GENERAL_REGS)
|
|
saw_general_regs = 1;
|
|
regset->store_function (regcache, buf);
|
|
regset ++;
|
|
free (buf);
|
|
}
|
|
if (saw_general_regs)
|
|
return 0;
|
|
else
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
regsets_store_inferior_registers (struct regcache *regcache)
|
|
{
|
|
struct regset_info *regset;
|
|
int saw_general_regs = 0;
|
|
int pid;
|
|
struct iovec iov;
|
|
|
|
regset = target_regsets;
|
|
|
|
pid = lwpid_of (get_thread_lwp (current_inferior));
|
|
while (regset->size >= 0)
|
|
{
|
|
void *buf, *data;
|
|
int nt_type, res;
|
|
|
|
if (regset->size == 0 || disabled_regsets[regset - target_regsets])
|
|
{
|
|
regset ++;
|
|
continue;
|
|
}
|
|
|
|
buf = xmalloc (regset->size);
|
|
|
|
/* First fill the buffer with the current register set contents,
|
|
in case there are any items in the kernel's regset that are
|
|
not in gdbserver's regcache. */
|
|
|
|
nt_type = regset->nt_type;
|
|
if (nt_type)
|
|
{
|
|
iov.iov_base = buf;
|
|
iov.iov_len = regset->size;
|
|
data = (void *) &iov;
|
|
}
|
|
else
|
|
data = buf;
|
|
|
|
#ifndef __sparc__
|
|
res = ptrace (regset->get_request, pid, nt_type, data);
|
|
#else
|
|
res = ptrace (regset->get_request, pid, &iov, data);
|
|
#endif
|
|
|
|
if (res == 0)
|
|
{
|
|
/* Then overlay our cached registers on that. */
|
|
regset->fill_function (regcache, buf);
|
|
|
|
/* Only now do we write the register set. */
|
|
#ifndef __sparc__
|
|
res = ptrace (regset->set_request, pid, nt_type, data);
|
|
#else
|
|
res = ptrace (regset->set_request, pid, data, nt_type);
|
|
#endif
|
|
}
|
|
|
|
if (res < 0)
|
|
{
|
|
if (errno == EIO)
|
|
{
|
|
/* If we get EIO on a regset, do not try it again for
|
|
this process. */
|
|
disabled_regsets[regset - target_regsets] = 1;
|
|
free (buf);
|
|
continue;
|
|
}
|
|
else if (errno == ESRCH)
|
|
{
|
|
/* At this point, ESRCH should mean the process is
|
|
already gone, in which case we simply ignore attempts
|
|
to change its registers. See also the related
|
|
comment in linux_resume_one_lwp. */
|
|
free (buf);
|
|
return 0;
|
|
}
|
|
else
|
|
{
|
|
perror ("Warning: ptrace(regsets_store_inferior_registers)");
|
|
}
|
|
}
|
|
else if (regset->type == GENERAL_REGS)
|
|
saw_general_regs = 1;
|
|
regset ++;
|
|
free (buf);
|
|
}
|
|
if (saw_general_regs)
|
|
return 0;
|
|
else
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
#endif /* HAVE_LINUX_REGSETS */
|
|
|
|
|
|
void
|
|
linux_fetch_registers (struct regcache *regcache, int regno)
|
|
{
|
|
#ifdef HAVE_LINUX_REGSETS
|
|
if (regsets_fetch_inferior_registers (regcache) == 0)
|
|
return;
|
|
#endif
|
|
#ifdef HAVE_LINUX_USRREGS
|
|
usr_fetch_inferior_registers (regcache, regno);
|
|
#endif
|
|
}
|
|
|
|
void
|
|
linux_store_registers (struct regcache *regcache, int regno)
|
|
{
|
|
#ifdef HAVE_LINUX_REGSETS
|
|
if (regsets_store_inferior_registers (regcache) == 0)
|
|
return;
|
|
#endif
|
|
#ifdef HAVE_LINUX_USRREGS
|
|
usr_store_inferior_registers (regcache, regno);
|
|
#endif
|
|
}
|
|
|
|
|
|
/* Copy LEN bytes from inferior's memory starting at MEMADDR
|
|
to debugger memory starting at MYADDR. */
|
|
|
|
static int
|
|
linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
|
|
{
|
|
register int i;
|
|
/* Round starting address down to longword boundary. */
|
|
register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
|
|
/* Round ending address up; get number of longwords that makes. */
|
|
register int count
|
|
= (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
|
|
/ sizeof (PTRACE_XFER_TYPE);
|
|
/* Allocate buffer of that many longwords. */
|
|
register PTRACE_XFER_TYPE *buffer
|
|
= (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
|
|
int fd;
|
|
char filename[64];
|
|
int pid = lwpid_of (get_thread_lwp (current_inferior));
|
|
|
|
/* Try using /proc. Don't bother for one word. */
|
|
if (len >= 3 * sizeof (long))
|
|
{
|
|
/* We could keep this file open and cache it - possibly one per
|
|
thread. That requires some juggling, but is even faster. */
|
|
sprintf (filename, "/proc/%d/mem", pid);
|
|
fd = open (filename, O_RDONLY | O_LARGEFILE);
|
|
if (fd == -1)
|
|
goto no_proc;
|
|
|
|
/* If pread64 is available, use it. It's faster if the kernel
|
|
supports it (only one syscall), and it's 64-bit safe even on
|
|
32-bit platforms (for instance, SPARC debugging a SPARC64
|
|
application). */
|
|
#ifdef HAVE_PREAD64
|
|
if (pread64 (fd, myaddr, len, memaddr) != len)
|
|
#else
|
|
if (lseek (fd, memaddr, SEEK_SET) == -1 || read (fd, myaddr, len) != len)
|
|
#endif
|
|
{
|
|
close (fd);
|
|
goto no_proc;
|
|
}
|
|
|
|
close (fd);
|
|
return 0;
|
|
}
|
|
|
|
no_proc:
|
|
/* Read all the longwords */
|
|
for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
|
|
{
|
|
errno = 0;
|
|
/* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
|
|
about coercing an 8 byte integer to a 4 byte pointer. */
|
|
buffer[i] = ptrace (PTRACE_PEEKTEXT, pid,
|
|
(PTRACE_ARG3_TYPE) (uintptr_t) addr, 0);
|
|
if (errno)
|
|
return errno;
|
|
}
|
|
|
|
/* Copy appropriate bytes out of the buffer. */
|
|
memcpy (myaddr,
|
|
(char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
|
|
len);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
|
|
memory at MEMADDR. On failure (cannot write to the inferior)
|
|
returns the value of errno. */
|
|
|
|
static int
|
|
linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
|
|
{
|
|
register int i;
|
|
/* Round starting address down to longword boundary. */
|
|
register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
|
|
/* Round ending address up; get number of longwords that makes. */
|
|
register int count
|
|
= (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
|
|
/ sizeof (PTRACE_XFER_TYPE);
|
|
|
|
/* Allocate buffer of that many longwords. */
|
|
register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *)
|
|
alloca (count * sizeof (PTRACE_XFER_TYPE));
|
|
|
|
int pid = lwpid_of (get_thread_lwp (current_inferior));
|
|
|
|
if (debug_threads)
|
|
{
|
|
/* Dump up to four bytes. */
|
|
unsigned int val = * (unsigned int *) myaddr;
|
|
if (len == 1)
|
|
val = val & 0xff;
|
|
else if (len == 2)
|
|
val = val & 0xffff;
|
|
else if (len == 3)
|
|
val = val & 0xffffff;
|
|
fprintf (stderr, "Writing %0*x to 0x%08lx\n", 2 * ((len < 4) ? len : 4),
|
|
val, (long)memaddr);
|
|
}
|
|
|
|
/* Fill start and end extra bytes of buffer with existing memory data. */
|
|
|
|
errno = 0;
|
|
/* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
|
|
about coercing an 8 byte integer to a 4 byte pointer. */
|
|
buffer[0] = ptrace (PTRACE_PEEKTEXT, pid,
|
|
(PTRACE_ARG3_TYPE) (uintptr_t) addr, 0);
|
|
if (errno)
|
|
return errno;
|
|
|
|
if (count > 1)
|
|
{
|
|
errno = 0;
|
|
buffer[count - 1]
|
|
= ptrace (PTRACE_PEEKTEXT, pid,
|
|
/* Coerce to a uintptr_t first to avoid potential gcc warning
|
|
about coercing an 8 byte integer to a 4 byte pointer. */
|
|
(PTRACE_ARG3_TYPE) (uintptr_t) (addr + (count - 1)
|
|
* sizeof (PTRACE_XFER_TYPE)),
|
|
0);
|
|
if (errno)
|
|
return errno;
|
|
}
|
|
|
|
/* Copy data to be written over corresponding part of buffer. */
|
|
|
|
memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
|
|
myaddr, len);
|
|
|
|
/* Write the entire buffer. */
|
|
|
|
for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
|
|
{
|
|
errno = 0;
|
|
ptrace (PTRACE_POKETEXT, pid,
|
|
/* Coerce to a uintptr_t first to avoid potential gcc warning
|
|
about coercing an 8 byte integer to a 4 byte pointer. */
|
|
(PTRACE_ARG3_TYPE) (uintptr_t) addr,
|
|
(PTRACE_ARG4_TYPE) buffer[i]);
|
|
if (errno)
|
|
return errno;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Non-zero if the kernel supports PTRACE_O_TRACEFORK. */
|
|
static int linux_supports_tracefork_flag;
|
|
|
|
static void
|
|
linux_enable_event_reporting (int pid)
|
|
{
|
|
if (!linux_supports_tracefork_flag)
|
|
return;
|
|
|
|
ptrace (PTRACE_SETOPTIONS, pid, 0, (PTRACE_ARG4_TYPE) PTRACE_O_TRACECLONE);
|
|
}
|
|
|
|
/* Helper functions for linux_test_for_tracefork, called via clone (). */
|
|
|
|
static int
|
|
linux_tracefork_grandchild (void *arg)
|
|
{
|
|
_exit (0);
|
|
}
|
|
|
|
#define STACK_SIZE 4096
|
|
|
|
static int
|
|
linux_tracefork_child (void *arg)
|
|
{
|
|
ptrace (PTRACE_TRACEME, 0, 0, 0);
|
|
kill (getpid (), SIGSTOP);
|
|
|
|
#if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
|
|
|
|
if (fork () == 0)
|
|
linux_tracefork_grandchild (NULL);
|
|
|
|
#else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
|
|
|
|
#ifdef __ia64__
|
|
__clone2 (linux_tracefork_grandchild, arg, STACK_SIZE,
|
|
CLONE_VM | SIGCHLD, NULL);
|
|
#else
|
|
clone (linux_tracefork_grandchild, (char *) arg + STACK_SIZE,
|
|
CLONE_VM | SIGCHLD, NULL);
|
|
#endif
|
|
|
|
#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
|
|
|
|
_exit (0);
|
|
}
|
|
|
|
/* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
|
|
sure that we can enable the option, and that it had the desired
|
|
effect. */
|
|
|
|
static void
|
|
linux_test_for_tracefork (void)
|
|
{
|
|
int child_pid, ret, status;
|
|
long second_pid;
|
|
#if defined(__UCLIBC__) && defined(HAS_NOMMU)
|
|
char *stack = xmalloc (STACK_SIZE * 4);
|
|
#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
|
|
|
|
linux_supports_tracefork_flag = 0;
|
|
|
|
#if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
|
|
|
|
child_pid = fork ();
|
|
if (child_pid == 0)
|
|
linux_tracefork_child (NULL);
|
|
|
|
#else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
|
|
|
|
/* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
|
|
#ifdef __ia64__
|
|
child_pid = __clone2 (linux_tracefork_child, stack, STACK_SIZE,
|
|
CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
|
|
#else /* !__ia64__ */
|
|
child_pid = clone (linux_tracefork_child, stack + STACK_SIZE,
|
|
CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
|
|
#endif /* !__ia64__ */
|
|
|
|
#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
|
|
|
|
if (child_pid == -1)
|
|
perror_with_name ("clone");
|
|
|
|
ret = my_waitpid (child_pid, &status, 0);
|
|
if (ret == -1)
|
|
perror_with_name ("waitpid");
|
|
else if (ret != child_pid)
|
|
error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret);
|
|
if (! WIFSTOPPED (status))
|
|
error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status);
|
|
|
|
ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0,
|
|
(PTRACE_ARG4_TYPE) PTRACE_O_TRACEFORK);
|
|
if (ret != 0)
|
|
{
|
|
ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
|
|
if (ret != 0)
|
|
{
|
|
warning ("linux_test_for_tracefork: failed to kill child");
|
|
return;
|
|
}
|
|
|
|
ret = my_waitpid (child_pid, &status, 0);
|
|
if (ret != child_pid)
|
|
warning ("linux_test_for_tracefork: failed to wait for killed child");
|
|
else if (!WIFSIGNALED (status))
|
|
warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
|
|
"killed child", status);
|
|
|
|
return;
|
|
}
|
|
|
|
ret = ptrace (PTRACE_CONT, child_pid, 0, 0);
|
|
if (ret != 0)
|
|
warning ("linux_test_for_tracefork: failed to resume child");
|
|
|
|
ret = my_waitpid (child_pid, &status, 0);
|
|
|
|
if (ret == child_pid && WIFSTOPPED (status)
|
|
&& status >> 16 == PTRACE_EVENT_FORK)
|
|
{
|
|
second_pid = 0;
|
|
ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
|
|
if (ret == 0 && second_pid != 0)
|
|
{
|
|
int second_status;
|
|
|
|
linux_supports_tracefork_flag = 1;
|
|
my_waitpid (second_pid, &second_status, 0);
|
|
ret = ptrace (PTRACE_KILL, second_pid, 0, 0);
|
|
if (ret != 0)
|
|
warning ("linux_test_for_tracefork: failed to kill second child");
|
|
my_waitpid (second_pid, &status, 0);
|
|
}
|
|
}
|
|
else
|
|
warning ("linux_test_for_tracefork: unexpected result from waitpid "
|
|
"(%d, status 0x%x)", ret, status);
|
|
|
|
do
|
|
{
|
|
ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
|
|
if (ret != 0)
|
|
warning ("linux_test_for_tracefork: failed to kill child");
|
|
my_waitpid (child_pid, &status, 0);
|
|
}
|
|
while (WIFSTOPPED (status));
|
|
|
|
#if defined(__UCLIBC__) && defined(HAS_NOMMU)
|
|
free (stack);
|
|
#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
|
|
}
|
|
|
|
|
|
static void
|
|
linux_look_up_symbols (void)
|
|
{
|
|
#ifdef USE_THREAD_DB
|
|
struct process_info *proc = current_process ();
|
|
|
|
if (proc->private->thread_db != NULL)
|
|
return;
|
|
|
|
/* If the kernel supports tracing forks then it also supports tracing
|
|
clones, and then we don't need to use the magic thread event breakpoint
|
|
to learn about threads. */
|
|
thread_db_init (!linux_supports_tracefork_flag);
|
|
#endif
|
|
}
|
|
|
|
static void
|
|
linux_request_interrupt (void)
|
|
{
|
|
extern unsigned long signal_pid;
|
|
|
|
if (!ptid_equal (cont_thread, null_ptid)
|
|
&& !ptid_equal (cont_thread, minus_one_ptid))
|
|
{
|
|
struct lwp_info *lwp;
|
|
int lwpid;
|
|
|
|
lwp = get_thread_lwp (current_inferior);
|
|
lwpid = lwpid_of (lwp);
|
|
kill_lwp (lwpid, SIGINT);
|
|
}
|
|
else
|
|
kill_lwp (signal_pid, SIGINT);
|
|
}
|
|
|
|
/* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
|
|
to debugger memory starting at MYADDR. */
|
|
|
|
static int
|
|
linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len)
|
|
{
|
|
char filename[PATH_MAX];
|
|
int fd, n;
|
|
int pid = lwpid_of (get_thread_lwp (current_inferior));
|
|
|
|
xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
|
|
|
|
fd = open (filename, O_RDONLY);
|
|
if (fd < 0)
|
|
return -1;
|
|
|
|
if (offset != (CORE_ADDR) 0
|
|
&& lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
|
|
n = -1;
|
|
else
|
|
n = read (fd, myaddr, len);
|
|
|
|
close (fd);
|
|
|
|
return n;
|
|
}
|
|
|
|
/* These breakpoint and watchpoint related wrapper functions simply
|
|
pass on the function call if the target has registered a
|
|
corresponding function. */
|
|
|
|
static int
|
|
linux_insert_point (char type, CORE_ADDR addr, int len)
|
|
{
|
|
if (the_low_target.insert_point != NULL)
|
|
return the_low_target.insert_point (type, addr, len);
|
|
else
|
|
/* Unsupported (see target.h). */
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
linux_remove_point (char type, CORE_ADDR addr, int len)
|
|
{
|
|
if (the_low_target.remove_point != NULL)
|
|
return the_low_target.remove_point (type, addr, len);
|
|
else
|
|
/* Unsupported (see target.h). */
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
linux_stopped_by_watchpoint (void)
|
|
{
|
|
struct lwp_info *lwp = get_thread_lwp (current_inferior);
|
|
|
|
return lwp->stopped_by_watchpoint;
|
|
}
|
|
|
|
static CORE_ADDR
|
|
linux_stopped_data_address (void)
|
|
{
|
|
struct lwp_info *lwp = get_thread_lwp (current_inferior);
|
|
|
|
return lwp->stopped_data_address;
|
|
}
|
|
|
|
#if defined(__UCLIBC__) && defined(HAS_NOMMU)
|
|
#if defined(__mcoldfire__)
|
|
/* These should really be defined in the kernel's ptrace.h header. */
|
|
#define PT_TEXT_ADDR 49*4
|
|
#define PT_DATA_ADDR 50*4
|
|
#define PT_TEXT_END_ADDR 51*4
|
|
#elif defined(BFIN)
|
|
#define PT_TEXT_ADDR 220
|
|
#define PT_TEXT_END_ADDR 224
|
|
#define PT_DATA_ADDR 228
|
|
#endif
|
|
|
|
/* Under uClinux, programs are loaded at non-zero offsets, which we need
|
|
to tell gdb about. */
|
|
|
|
static int
|
|
linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p)
|
|
{
|
|
#if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
|
|
unsigned long text, text_end, data;
|
|
int pid = lwpid_of (get_thread_lwp (current_inferior));
|
|
|
|
errno = 0;
|
|
|
|
text = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_ADDR, 0);
|
|
text_end = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_END_ADDR, 0);
|
|
data = ptrace (PTRACE_PEEKUSER, pid, (long)PT_DATA_ADDR, 0);
|
|
|
|
if (errno == 0)
|
|
{
|
|
/* Both text and data offsets produced at compile-time (and so
|
|
used by gdb) are relative to the beginning of the program,
|
|
with the data segment immediately following the text segment.
|
|
However, the actual runtime layout in memory may put the data
|
|
somewhere else, so when we send gdb a data base-address, we
|
|
use the real data base address and subtract the compile-time
|
|
data base-address from it (which is just the length of the
|
|
text segment). BSS immediately follows data in both
|
|
cases. */
|
|
*text_p = text;
|
|
*data_p = data - (text_end - text);
|
|
|
|
return 1;
|
|
}
|
|
#endif
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static int
|
|
compare_ints (const void *xa, const void *xb)
|
|
{
|
|
int a = *(const int *)xa;
|
|
int b = *(const int *)xb;
|
|
|
|
return a - b;
|
|
}
|
|
|
|
static int *
|
|
unique (int *b, int *e)
|
|
{
|
|
int *d = b;
|
|
while (++b != e)
|
|
if (*d != *b)
|
|
*++d = *b;
|
|
return ++d;
|
|
}
|
|
|
|
/* Given PID, iterates over all threads in that process.
|
|
|
|
Information about each thread, in a format suitable for qXfer:osdata:thread
|
|
is printed to BUFFER, if it's not NULL. BUFFER is assumed to be already
|
|
initialized, and the caller is responsible for finishing and appending '\0'
|
|
to it.
|
|
|
|
The list of cores that threads are running on is assigned to *CORES, if it
|
|
is not NULL. If no cores are found, *CORES will be set to NULL. Caller
|
|
should free *CORES. */
|
|
|
|
static void
|
|
list_threads (int pid, struct buffer *buffer, char **cores)
|
|
{
|
|
int count = 0;
|
|
int allocated = 10;
|
|
int *core_numbers = xmalloc (sizeof (int) * allocated);
|
|
char pathname[128];
|
|
DIR *dir;
|
|
struct dirent *dp;
|
|
struct stat statbuf;
|
|
|
|
sprintf (pathname, "/proc/%d/task", pid);
|
|
if (stat (pathname, &statbuf) == 0 && S_ISDIR (statbuf.st_mode))
|
|
{
|
|
dir = opendir (pathname);
|
|
if (!dir)
|
|
{
|
|
free (core_numbers);
|
|
return;
|
|
}
|
|
|
|
while ((dp = readdir (dir)) != NULL)
|
|
{
|
|
unsigned long lwp = strtoul (dp->d_name, NULL, 10);
|
|
|
|
if (lwp != 0)
|
|
{
|
|
unsigned core = linux_core_of_thread (ptid_build (pid, lwp, 0));
|
|
|
|
if (core != -1)
|
|
{
|
|
char s[sizeof ("4294967295")];
|
|
sprintf (s, "%u", core);
|
|
|
|
if (count == allocated)
|
|
{
|
|
allocated *= 2;
|
|
core_numbers = realloc (core_numbers,
|
|
sizeof (int) * allocated);
|
|
}
|
|
core_numbers[count++] = core;
|
|
if (buffer)
|
|
buffer_xml_printf (buffer,
|
|
"<item>"
|
|
"<column name=\"pid\">%d</column>"
|
|
"<column name=\"tid\">%s</column>"
|
|
"<column name=\"core\">%s</column>"
|
|
"</item>", pid, dp->d_name, s);
|
|
}
|
|
else
|
|
{
|
|
if (buffer)
|
|
buffer_xml_printf (buffer,
|
|
"<item>"
|
|
"<column name=\"pid\">%d</column>"
|
|
"<column name=\"tid\">%s</column>"
|
|
"</item>", pid, dp->d_name);
|
|
}
|
|
}
|
|
}
|
|
closedir (dir);
|
|
}
|
|
|
|
if (cores)
|
|
{
|
|
*cores = NULL;
|
|
if (count > 0)
|
|
{
|
|
struct buffer buffer2;
|
|
int *b;
|
|
int *e;
|
|
qsort (core_numbers, count, sizeof (int), compare_ints);
|
|
|
|
/* Remove duplicates. */
|
|
b = core_numbers;
|
|
e = unique (b, core_numbers + count);
|
|
|
|
buffer_init (&buffer2);
|
|
|
|
for (b = core_numbers; b != e; ++b)
|
|
{
|
|
char number[sizeof ("4294967295")];
|
|
sprintf (number, "%u", *b);
|
|
buffer_xml_printf (&buffer2, "%s%s",
|
|
(b == core_numbers) ? "" : ",", number);
|
|
}
|
|
buffer_grow_str0 (&buffer2, "");
|
|
|
|
*cores = buffer_finish (&buffer2);
|
|
}
|
|
}
|
|
free (core_numbers);
|
|
}
|
|
|
|
static void
|
|
show_process (int pid, const char *username, struct buffer *buffer)
|
|
{
|
|
char pathname[128];
|
|
FILE *f;
|
|
char cmd[MAXPATHLEN + 1];
|
|
|
|
sprintf (pathname, "/proc/%d/cmdline", pid);
|
|
|
|
if ((f = fopen (pathname, "r")) != NULL)
|
|
{
|
|
size_t len = fread (cmd, 1, sizeof (cmd) - 1, f);
|
|
if (len > 0)
|
|
{
|
|
char *cores = 0;
|
|
int i;
|
|
for (i = 0; i < len; i++)
|
|
if (cmd[i] == '\0')
|
|
cmd[i] = ' ';
|
|
cmd[len] = '\0';
|
|
|
|
buffer_xml_printf (buffer,
|
|
"<item>"
|
|
"<column name=\"pid\">%d</column>"
|
|
"<column name=\"user\">%s</column>"
|
|
"<column name=\"command\">%s</column>",
|
|
pid,
|
|
username,
|
|
cmd);
|
|
|
|
/* This only collects core numbers, and does not print threads. */
|
|
list_threads (pid, NULL, &cores);
|
|
|
|
if (cores)
|
|
{
|
|
buffer_xml_printf (buffer,
|
|
"<column name=\"cores\">%s</column>", cores);
|
|
free (cores);
|
|
}
|
|
|
|
buffer_xml_printf (buffer, "</item>");
|
|
}
|
|
fclose (f);
|
|
}
|
|
}
|
|
|
|
static int
|
|
linux_qxfer_osdata (const char *annex,
|
|
unsigned char *readbuf, unsigned const char *writebuf,
|
|
CORE_ADDR offset, int len)
|
|
{
|
|
/* We make the process list snapshot when the object starts to be
|
|
read. */
|
|
static const char *buf;
|
|
static long len_avail = -1;
|
|
static struct buffer buffer;
|
|
int processes = 0;
|
|
int threads = 0;
|
|
|
|
DIR *dirp;
|
|
|
|
if (strcmp (annex, "processes") == 0)
|
|
processes = 1;
|
|
else if (strcmp (annex, "threads") == 0)
|
|
threads = 1;
|
|
else
|
|
return 0;
|
|
|
|
if (!readbuf || writebuf)
|
|
return 0;
|
|
|
|
if (offset == 0)
|
|
{
|
|
if (len_avail != -1 && len_avail != 0)
|
|
buffer_free (&buffer);
|
|
len_avail = 0;
|
|
buf = NULL;
|
|
buffer_init (&buffer);
|
|
if (processes)
|
|
buffer_grow_str (&buffer, "<osdata type=\"processes\">");
|
|
else if (threads)
|
|
buffer_grow_str (&buffer, "<osdata type=\"threads\">");
|
|
|
|
dirp = opendir ("/proc");
|
|
if (dirp)
|
|
{
|
|
struct dirent *dp;
|
|
while ((dp = readdir (dirp)) != NULL)
|
|
{
|
|
struct stat statbuf;
|
|
char procentry[sizeof ("/proc/4294967295")];
|
|
|
|
if (!isdigit (dp->d_name[0])
|
|
|| strlen (dp->d_name) > sizeof ("4294967295") - 1)
|
|
continue;
|
|
|
|
sprintf (procentry, "/proc/%s", dp->d_name);
|
|
if (stat (procentry, &statbuf) == 0
|
|
&& S_ISDIR (statbuf.st_mode))
|
|
{
|
|
int pid = (int) strtoul (dp->d_name, NULL, 10);
|
|
|
|
if (processes)
|
|
{
|
|
struct passwd *entry = getpwuid (statbuf.st_uid);
|
|
show_process (pid, entry ? entry->pw_name : "?", &buffer);
|
|
}
|
|
else if (threads)
|
|
{
|
|
list_threads (pid, &buffer, NULL);
|
|
}
|
|
}
|
|
}
|
|
|
|
closedir (dirp);
|
|
}
|
|
buffer_grow_str0 (&buffer, "</osdata>\n");
|
|
buf = buffer_finish (&buffer);
|
|
len_avail = strlen (buf);
|
|
}
|
|
|
|
if (offset >= len_avail)
|
|
{
|
|
/* Done. Get rid of the data. */
|
|
buffer_free (&buffer);
|
|
buf = NULL;
|
|
len_avail = 0;
|
|
return 0;
|
|
}
|
|
|
|
if (len > len_avail - offset)
|
|
len = len_avail - offset;
|
|
memcpy (readbuf, buf + offset, len);
|
|
|
|
return len;
|
|
}
|
|
|
|
/* Convert a native/host siginfo object, into/from the siginfo in the
|
|
layout of the inferiors' architecture. */
|
|
|
|
static void
|
|
siginfo_fixup (struct siginfo *siginfo, void *inf_siginfo, int direction)
|
|
{
|
|
int done = 0;
|
|
|
|
if (the_low_target.siginfo_fixup != NULL)
|
|
done = the_low_target.siginfo_fixup (siginfo, inf_siginfo, direction);
|
|
|
|
/* If there was no callback, or the callback didn't do anything,
|
|
then just do a straight memcpy. */
|
|
if (!done)
|
|
{
|
|
if (direction == 1)
|
|
memcpy (siginfo, inf_siginfo, sizeof (struct siginfo));
|
|
else
|
|
memcpy (inf_siginfo, siginfo, sizeof (struct siginfo));
|
|
}
|
|
}
|
|
|
|
static int
|
|
linux_xfer_siginfo (const char *annex, unsigned char *readbuf,
|
|
unsigned const char *writebuf, CORE_ADDR offset, int len)
|
|
{
|
|
int pid;
|
|
struct siginfo siginfo;
|
|
char inf_siginfo[sizeof (struct siginfo)];
|
|
|
|
if (current_inferior == NULL)
|
|
return -1;
|
|
|
|
pid = lwpid_of (get_thread_lwp (current_inferior));
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr, "%s siginfo for lwp %d.\n",
|
|
readbuf != NULL ? "Reading" : "Writing",
|
|
pid);
|
|
|
|
if (offset >= sizeof (siginfo))
|
|
return -1;
|
|
|
|
if (ptrace (PTRACE_GETSIGINFO, pid, 0, &siginfo) != 0)
|
|
return -1;
|
|
|
|
/* When GDBSERVER is built as a 64-bit application, ptrace writes into
|
|
SIGINFO an object with 64-bit layout. Since debugging a 32-bit
|
|
inferior with a 64-bit GDBSERVER should look the same as debugging it
|
|
with a 32-bit GDBSERVER, we need to convert it. */
|
|
siginfo_fixup (&siginfo, inf_siginfo, 0);
|
|
|
|
if (offset + len > sizeof (siginfo))
|
|
len = sizeof (siginfo) - offset;
|
|
|
|
if (readbuf != NULL)
|
|
memcpy (readbuf, inf_siginfo + offset, len);
|
|
else
|
|
{
|
|
memcpy (inf_siginfo + offset, writebuf, len);
|
|
|
|
/* Convert back to ptrace layout before flushing it out. */
|
|
siginfo_fixup (&siginfo, inf_siginfo, 1);
|
|
|
|
if (ptrace (PTRACE_SETSIGINFO, pid, 0, &siginfo) != 0)
|
|
return -1;
|
|
}
|
|
|
|
return len;
|
|
}
|
|
|
|
/* SIGCHLD handler that serves two purposes: In non-stop/async mode,
|
|
so we notice when children change state; as the handler for the
|
|
sigsuspend in my_waitpid. */
|
|
|
|
static void
|
|
sigchld_handler (int signo)
|
|
{
|
|
int old_errno = errno;
|
|
|
|
if (debug_threads)
|
|
{
|
|
do
|
|
{
|
|
/* fprintf is not async-signal-safe, so call write
|
|
directly. */
|
|
if (write (2, "sigchld_handler\n",
|
|
sizeof ("sigchld_handler\n") - 1) < 0)
|
|
break; /* just ignore */
|
|
} while (0);
|
|
}
|
|
|
|
if (target_is_async_p ())
|
|
async_file_mark (); /* trigger a linux_wait */
|
|
|
|
errno = old_errno;
|
|
}
|
|
|
|
static int
|
|
linux_supports_non_stop (void)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
linux_async (int enable)
|
|
{
|
|
int previous = (linux_event_pipe[0] != -1);
|
|
|
|
if (debug_threads)
|
|
fprintf (stderr, "linux_async (%d), previous=%d\n",
|
|
enable, previous);
|
|
|
|
if (previous != enable)
|
|
{
|
|
sigset_t mask;
|
|
sigemptyset (&mask);
|
|
sigaddset (&mask, SIGCHLD);
|
|
|
|
sigprocmask (SIG_BLOCK, &mask, NULL);
|
|
|
|
if (enable)
|
|
{
|
|
if (pipe (linux_event_pipe) == -1)
|
|
fatal ("creating event pipe failed.");
|
|
|
|
fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK);
|
|
fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK);
|
|
|
|
/* Register the event loop handler. */
|
|
add_file_handler (linux_event_pipe[0],
|
|
handle_target_event, NULL);
|
|
|
|
/* Always trigger a linux_wait. */
|
|
async_file_mark ();
|
|
}
|
|
else
|
|
{
|
|
delete_file_handler (linux_event_pipe[0]);
|
|
|
|
close (linux_event_pipe[0]);
|
|
close (linux_event_pipe[1]);
|
|
linux_event_pipe[0] = -1;
|
|
linux_event_pipe[1] = -1;
|
|
}
|
|
|
|
sigprocmask (SIG_UNBLOCK, &mask, NULL);
|
|
}
|
|
|
|
return previous;
|
|
}
|
|
|
|
static int
|
|
linux_start_non_stop (int nonstop)
|
|
{
|
|
/* Register or unregister from event-loop accordingly. */
|
|
linux_async (nonstop);
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
linux_supports_multi_process (void)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
|
|
/* Enumerate spufs IDs for process PID. */
|
|
static int
|
|
spu_enumerate_spu_ids (long pid, unsigned char *buf, CORE_ADDR offset, int len)
|
|
{
|
|
int pos = 0;
|
|
int written = 0;
|
|
char path[128];
|
|
DIR *dir;
|
|
struct dirent *entry;
|
|
|
|
sprintf (path, "/proc/%ld/fd", pid);
|
|
dir = opendir (path);
|
|
if (!dir)
|
|
return -1;
|
|
|
|
rewinddir (dir);
|
|
while ((entry = readdir (dir)) != NULL)
|
|
{
|
|
struct stat st;
|
|
struct statfs stfs;
|
|
int fd;
|
|
|
|
fd = atoi (entry->d_name);
|
|
if (!fd)
|
|
continue;
|
|
|
|
sprintf (path, "/proc/%ld/fd/%d", pid, fd);
|
|
if (stat (path, &st) != 0)
|
|
continue;
|
|
if (!S_ISDIR (st.st_mode))
|
|
continue;
|
|
|
|
if (statfs (path, &stfs) != 0)
|
|
continue;
|
|
if (stfs.f_type != SPUFS_MAGIC)
|
|
continue;
|
|
|
|
if (pos >= offset && pos + 4 <= offset + len)
|
|
{
|
|
*(unsigned int *)(buf + pos - offset) = fd;
|
|
written += 4;
|
|
}
|
|
pos += 4;
|
|
}
|
|
|
|
closedir (dir);
|
|
return written;
|
|
}
|
|
|
|
/* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
|
|
object type, using the /proc file system. */
|
|
static int
|
|
linux_qxfer_spu (const char *annex, unsigned char *readbuf,
|
|
unsigned const char *writebuf,
|
|
CORE_ADDR offset, int len)
|
|
{
|
|
long pid = lwpid_of (get_thread_lwp (current_inferior));
|
|
char buf[128];
|
|
int fd = 0;
|
|
int ret = 0;
|
|
|
|
if (!writebuf && !readbuf)
|
|
return -1;
|
|
|
|
if (!*annex)
|
|
{
|
|
if (!readbuf)
|
|
return -1;
|
|
else
|
|
return spu_enumerate_spu_ids (pid, readbuf, offset, len);
|
|
}
|
|
|
|
sprintf (buf, "/proc/%ld/fd/%s", pid, annex);
|
|
fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
|
|
if (fd <= 0)
|
|
return -1;
|
|
|
|
if (offset != 0
|
|
&& lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
|
|
{
|
|
close (fd);
|
|
return 0;
|
|
}
|
|
|
|
if (writebuf)
|
|
ret = write (fd, writebuf, (size_t) len);
|
|
else
|
|
ret = read (fd, readbuf, (size_t) len);
|
|
|
|
close (fd);
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
linux_core_of_thread (ptid_t ptid)
|
|
{
|
|
char filename[sizeof ("/proc//task//stat")
|
|
+ 2 * 20 /* decimal digits for 2 numbers, max 2^64 bit each */
|
|
+ 1];
|
|
FILE *f;
|
|
char *content = NULL;
|
|
char *p;
|
|
char *ts = 0;
|
|
int content_read = 0;
|
|
int i;
|
|
int core;
|
|
|
|
sprintf (filename, "/proc/%d/task/%ld/stat",
|
|
ptid_get_pid (ptid), ptid_get_lwp (ptid));
|
|
f = fopen (filename, "r");
|
|
if (!f)
|
|
return -1;
|
|
|
|
for (;;)
|
|
{
|
|
int n;
|
|
content = realloc (content, content_read + 1024);
|
|
n = fread (content + content_read, 1, 1024, f);
|
|
content_read += n;
|
|
if (n < 1024)
|
|
{
|
|
content[content_read] = '\0';
|
|
break;
|
|
}
|
|
}
|
|
|
|
p = strchr (content, '(');
|
|
|
|
/* Skip ")". */
|
|
if (p != NULL)
|
|
p = strchr (p, ')');
|
|
if (p != NULL)
|
|
p++;
|
|
|
|
/* If the first field after program name has index 0, then core number is
|
|
the field with index 36. There's no constant for that anywhere. */
|
|
if (p != NULL)
|
|
p = strtok_r (p, " ", &ts);
|
|
for (i = 0; p != NULL && i != 36; ++i)
|
|
p = strtok_r (NULL, " ", &ts);
|
|
|
|
if (p == NULL || sscanf (p, "%d", &core) == 0)
|
|
core = -1;
|
|
|
|
free (content);
|
|
fclose (f);
|
|
|
|
return core;
|
|
}
|
|
|
|
static void
|
|
linux_process_qsupported (const char *query)
|
|
{
|
|
if (the_low_target.process_qsupported != NULL)
|
|
the_low_target.process_qsupported (query);
|
|
}
|
|
|
|
static int
|
|
linux_supports_tracepoints (void)
|
|
{
|
|
if (*the_low_target.supports_tracepoints == NULL)
|
|
return 0;
|
|
|
|
return (*the_low_target.supports_tracepoints) ();
|
|
}
|
|
|
|
static CORE_ADDR
|
|
linux_read_pc (struct regcache *regcache)
|
|
{
|
|
if (the_low_target.get_pc == NULL)
|
|
return 0;
|
|
|
|
return (*the_low_target.get_pc) (regcache);
|
|
}
|
|
|
|
static void
|
|
linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
|
|
{
|
|
gdb_assert (the_low_target.set_pc != NULL);
|
|
|
|
(*the_low_target.set_pc) (regcache, pc);
|
|
}
|
|
|
|
static int
|
|
linux_thread_stopped (struct thread_info *thread)
|
|
{
|
|
return get_thread_lwp (thread)->stopped;
|
|
}
|
|
|
|
/* This exposes stop-all-threads functionality to other modules. */
|
|
|
|
static void
|
|
linux_pause_all (int freeze)
|
|
{
|
|
stop_all_lwps (freeze, NULL);
|
|
}
|
|
|
|
/* This exposes unstop-all-threads functionality to other gdbserver
|
|
modules. */
|
|
|
|
static void
|
|
linux_unpause_all (int unfreeze)
|
|
{
|
|
unstop_all_lwps (unfreeze, NULL);
|
|
}
|
|
|
|
static int
|
|
linux_prepare_to_access_memory (void)
|
|
{
|
|
/* Neither ptrace nor /proc/PID/mem allow accessing memory through a
|
|
running LWP. */
|
|
if (non_stop)
|
|
linux_pause_all (1);
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
linux_done_accessing_memory (void)
|
|
{
|
|
/* Neither ptrace nor /proc/PID/mem allow accessing memory through a
|
|
running LWP. */
|
|
if (non_stop)
|
|
linux_unpause_all (1);
|
|
}
|
|
|
|
static int
|
|
linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr,
|
|
CORE_ADDR collector,
|
|
CORE_ADDR lockaddr,
|
|
ULONGEST orig_size,
|
|
CORE_ADDR *jump_entry,
|
|
unsigned char *jjump_pad_insn,
|
|
ULONGEST *jjump_pad_insn_size,
|
|
CORE_ADDR *adjusted_insn_addr,
|
|
CORE_ADDR *adjusted_insn_addr_end)
|
|
{
|
|
return (*the_low_target.install_fast_tracepoint_jump_pad)
|
|
(tpoint, tpaddr, collector, lockaddr, orig_size,
|
|
jump_entry, jjump_pad_insn, jjump_pad_insn_size,
|
|
adjusted_insn_addr, adjusted_insn_addr_end);
|
|
}
|
|
|
|
static struct emit_ops *
|
|
linux_emit_ops (void)
|
|
{
|
|
if (the_low_target.emit_ops != NULL)
|
|
return (*the_low_target.emit_ops) ();
|
|
else
|
|
return NULL;
|
|
}
|
|
|
|
static struct target_ops linux_target_ops = {
|
|
linux_create_inferior,
|
|
linux_attach,
|
|
linux_kill,
|
|
linux_detach,
|
|
linux_mourn,
|
|
linux_join,
|
|
linux_thread_alive,
|
|
linux_resume,
|
|
linux_wait,
|
|
linux_fetch_registers,
|
|
linux_store_registers,
|
|
linux_prepare_to_access_memory,
|
|
linux_done_accessing_memory,
|
|
linux_read_memory,
|
|
linux_write_memory,
|
|
linux_look_up_symbols,
|
|
linux_request_interrupt,
|
|
linux_read_auxv,
|
|
linux_insert_point,
|
|
linux_remove_point,
|
|
linux_stopped_by_watchpoint,
|
|
linux_stopped_data_address,
|
|
#if defined(__UCLIBC__) && defined(HAS_NOMMU)
|
|
linux_read_offsets,
|
|
#else
|
|
NULL,
|
|
#endif
|
|
#ifdef USE_THREAD_DB
|
|
thread_db_get_tls_address,
|
|
#else
|
|
NULL,
|
|
#endif
|
|
linux_qxfer_spu,
|
|
hostio_last_error_from_errno,
|
|
linux_qxfer_osdata,
|
|
linux_xfer_siginfo,
|
|
linux_supports_non_stop,
|
|
linux_async,
|
|
linux_start_non_stop,
|
|
linux_supports_multi_process,
|
|
#ifdef USE_THREAD_DB
|
|
thread_db_handle_monitor_command,
|
|
#else
|
|
NULL,
|
|
#endif
|
|
linux_core_of_thread,
|
|
linux_process_qsupported,
|
|
linux_supports_tracepoints,
|
|
linux_read_pc,
|
|
linux_write_pc,
|
|
linux_thread_stopped,
|
|
NULL,
|
|
linux_pause_all,
|
|
linux_unpause_all,
|
|
linux_cancel_breakpoints,
|
|
linux_stabilize_threads,
|
|
linux_install_fast_tracepoint_jump_pad,
|
|
linux_emit_ops
|
|
};
|
|
|
|
static void
|
|
linux_init_signals ()
|
|
{
|
|
/* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
|
|
to find what the cancel signal actually is. */
|
|
#ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
|
|
signal (__SIGRTMIN+1, SIG_IGN);
|
|
#endif
|
|
}
|
|
|
|
void
|
|
initialize_low (void)
|
|
{
|
|
struct sigaction sigchld_action;
|
|
memset (&sigchld_action, 0, sizeof (sigchld_action));
|
|
set_target_ops (&linux_target_ops);
|
|
set_breakpoint_data (the_low_target.breakpoint,
|
|
the_low_target.breakpoint_len);
|
|
linux_init_signals ();
|
|
linux_test_for_tracefork ();
|
|
#ifdef HAVE_LINUX_REGSETS
|
|
for (num_regsets = 0; target_regsets[num_regsets].size >= 0; num_regsets++)
|
|
;
|
|
disabled_regsets = xmalloc (num_regsets);
|
|
#endif
|
|
|
|
sigchld_action.sa_handler = sigchld_handler;
|
|
sigemptyset (&sigchld_action.sa_mask);
|
|
sigchld_action.sa_flags = SA_RESTART;
|
|
sigaction (SIGCHLD, &sigchld_action, NULL);
|
|
}
|