4588 lines
129 KiB
C
4588 lines
129 KiB
C
/* GNU/Linux native-dependent code common to multiple platforms.
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Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
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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 "defs.h"
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#include "inferior.h"
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#include "target.h"
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#include "gdb_string.h"
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#include "gdb_wait.h"
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#include "gdb_assert.h"
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#ifdef HAVE_TKILL_SYSCALL
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#include <unistd.h>
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#include <sys/syscall.h>
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#endif
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#include <sys/ptrace.h>
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#include "linux-nat.h"
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#include "linux-fork.h"
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#include "gdbthread.h"
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#include "gdbcmd.h"
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#include "regcache.h"
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#include "regset.h"
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#include "inf-ptrace.h"
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#include "auxv.h"
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#include <sys/param.h> /* for MAXPATHLEN */
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#include <sys/procfs.h> /* for elf_gregset etc. */
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#include "elf-bfd.h" /* for elfcore_write_* */
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#include "gregset.h" /* for gregset */
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#include "gdbcore.h" /* for get_exec_file */
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#include <ctype.h> /* for isdigit */
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#include "gdbthread.h" /* for struct thread_info etc. */
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#include "gdb_stat.h" /* for struct stat */
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#include <fcntl.h> /* for O_RDONLY */
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#include "inf-loop.h"
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#include "event-loop.h"
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#include "event-top.h"
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#ifdef HAVE_PERSONALITY
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# include <sys/personality.h>
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# if !HAVE_DECL_ADDR_NO_RANDOMIZE
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# define ADDR_NO_RANDOMIZE 0x0040000
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# endif
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#endif /* HAVE_PERSONALITY */
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/* This comment documents high-level logic of this file.
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Waiting for events in sync mode
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===============================
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When waiting for an event in a specific thread, we just use waitpid, passing
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the specific pid, and not passing WNOHANG.
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When waiting for an event in all threads, waitpid is not quite good. Prior to
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version 2.4, Linux can either wait for event in main thread, or in secondary
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threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might
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miss an event. The solution is to use non-blocking waitpid, together with
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sigsuspend. First, we use non-blocking waitpid to get an event in the main
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process, if any. Second, we use non-blocking waitpid with the __WCLONED
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flag to check for events in cloned processes. If nothing is found, we use
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sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something
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happened to a child process -- and SIGCHLD will be delivered both for events
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in main debugged process and in cloned processes. As soon as we know there's
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an event, we get back to calling nonblocking waitpid with and without __WCLONED.
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Note that SIGCHLD should be blocked between waitpid and sigsuspend calls,
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so that we don't miss a signal. If SIGCHLD arrives in between, when it's
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blocked, the signal becomes pending and sigsuspend immediately
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notices it and returns.
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Waiting for events in async mode
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================================
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In async mode, GDB should always be ready to handle both user input and target
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events, so neither blocking waitpid nor sigsuspend are viable
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options. Instead, we should notify the GDB main event loop whenever there's
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unprocessed event from the target. The only way to notify this event loop is
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to make it wait on input from a pipe, and write something to the pipe whenever
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there's event. Obviously, if we fail to notify the event loop if there's
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target event, it's bad. If we notify the event loop when there's no event
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from target, linux-nat.c will detect that there's no event, actually, and
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report event of type TARGET_WAITKIND_IGNORE, but it will waste time and
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better avoided.
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The main design point is that every time GDB is outside linux-nat.c, we have a
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SIGCHLD handler installed that is called when something happens to the target
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and notifies the GDB event loop. Also, the event is extracted from the target
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using waitpid and stored for future use. Whenever GDB core decides to handle
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the event, and calls into linux-nat.c, we disable SIGCHLD and process things
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as in sync mode, except that before waitpid call we check if there are any
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previously read events.
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It could happen that during event processing, we'll try to get more events
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than there are events in the local queue, which will result to waitpid call.
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Those waitpid calls, while blocking, are guarantied to always have
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something for waitpid to return. E.g., stopping a thread with SIGSTOP, and
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waiting for the lwp to stop.
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The event loop is notified about new events using a pipe. SIGCHLD handler does
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waitpid and writes the results in to a pipe. GDB event loop has the other end
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of the pipe among the sources. When event loop starts to process the event
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and calls a function in linux-nat.c, all events from the pipe are transferred
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into a local queue and SIGCHLD is blocked. Further processing goes as in sync
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mode. Before we return from linux_nat_wait, we transfer all unprocessed events
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from local queue back to the pipe, so that when we get back to event loop,
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event loop will notice there's something more to do.
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SIGCHLD is blocked when we're inside target_wait, so that should we actually
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want to wait for some more events, SIGCHLD handler does not steal them from
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us. Technically, it would be possible to add new events to the local queue but
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it's about the same amount of work as blocking SIGCHLD.
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This moving of events from pipe into local queue and back into pipe when we
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enter/leave linux-nat.c is somewhat ugly. Unfortunately, GDB event loop is
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home-grown and incapable to wait on any queue.
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Use of signals
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==============
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We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
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signal is not entirely significant; we just need for a signal to be delivered,
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so that we can intercept it. SIGSTOP's advantage is that it can not be
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blocked. A disadvantage is that it is not a real-time signal, so it can only
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be queued once; we do not keep track of other sources of SIGSTOP.
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Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
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use them, because they have special behavior when the signal is generated -
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not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
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kills the entire thread group.
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A delivered SIGSTOP would stop the entire thread group, not just the thread we
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tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
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cancel it (by PTRACE_CONT without passing SIGSTOP).
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We could use a real-time signal instead. This would solve those problems; we
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could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
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But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
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generates it, and there are races with trying to find a signal that is not
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blocked. */
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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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here. */
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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 PTRACE_GETSIGINFO
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#define PTRACE_GETSIGINFO 0x4202
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#endif
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/* The single-threaded native GNU/Linux target_ops. We save a pointer for
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the use of the multi-threaded target. */
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static struct target_ops *linux_ops;
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static struct target_ops linux_ops_saved;
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/* The method to call, if any, when a new thread is attached. */
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static void (*linux_nat_new_thread) (ptid_t);
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/* The saved to_xfer_partial method, inherited from inf-ptrace.c.
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Called by our to_xfer_partial. */
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static LONGEST (*super_xfer_partial) (struct target_ops *,
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enum target_object,
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const char *, gdb_byte *,
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const gdb_byte *,
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ULONGEST, LONGEST);
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static int debug_linux_nat;
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static void
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show_debug_linux_nat (struct ui_file *file, int from_tty,
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struct cmd_list_element *c, const char *value)
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{
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fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"),
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value);
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}
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static int debug_linux_nat_async = 0;
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static void
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show_debug_linux_nat_async (struct ui_file *file, int from_tty,
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struct cmd_list_element *c, const char *value)
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{
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fprintf_filtered (file, _("Debugging of GNU/Linux async lwp module is %s.\n"),
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value);
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}
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static int disable_randomization = 1;
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static void
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show_disable_randomization (struct ui_file *file, int from_tty,
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struct cmd_list_element *c, const char *value)
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{
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#ifdef HAVE_PERSONALITY
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fprintf_filtered (file, _("\
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Disabling randomization of debuggee's virtual address space is %s.\n"),
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value);
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#else /* !HAVE_PERSONALITY */
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fputs_filtered (_("\
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Disabling randomization of debuggee's virtual address space is unsupported on\n\
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this platform.\n"), file);
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#endif /* !HAVE_PERSONALITY */
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}
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static void
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set_disable_randomization (char *args, int from_tty, struct cmd_list_element *c)
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{
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#ifndef HAVE_PERSONALITY
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error (_("\
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Disabling randomization of debuggee's virtual address space is unsupported on\n\
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this platform."));
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#endif /* !HAVE_PERSONALITY */
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}
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static int linux_parent_pid;
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struct simple_pid_list
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{
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int pid;
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int status;
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struct simple_pid_list *next;
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};
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struct simple_pid_list *stopped_pids;
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/* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACEFORK
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can not be used, 1 if it can. */
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static int linux_supports_tracefork_flag = -1;
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/* If we have PTRACE_O_TRACEFORK, this flag indicates whether we also have
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PTRACE_O_TRACEVFORKDONE. */
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static int linux_supports_tracevforkdone_flag = -1;
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/* Async mode support */
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/* Zero if the async mode, although enabled, is masked, which means
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linux_nat_wait should behave as if async mode was off. */
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static int linux_nat_async_mask_value = 1;
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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_nat_event_pipe[2] = { -1, -1 };
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/* Number of queued events in the pipe. */
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static volatile int linux_nat_num_queued_events;
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/* The possible SIGCHLD handling states. */
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enum sigchld_state
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{
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/* SIGCHLD disabled, with action set to sigchld_handler, for the
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sigsuspend in linux_nat_wait. */
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sigchld_sync,
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/* SIGCHLD enabled, with action set to async_sigchld_handler. */
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sigchld_async,
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/* Set SIGCHLD to default action. Used while creating an
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inferior. */
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sigchld_default
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};
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/* The current SIGCHLD handling state. */
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static enum sigchld_state linux_nat_async_events_state;
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static enum sigchld_state linux_nat_async_events (enum sigchld_state enable);
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static void pipe_to_local_event_queue (void);
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static void local_event_queue_to_pipe (void);
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static void linux_nat_event_pipe_push (int pid, int status, int options);
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static int linux_nat_event_pipe_pop (int* ptr_status, int* ptr_options);
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static void linux_nat_set_async_mode (int on);
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static void linux_nat_async (void (*callback)
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(enum inferior_event_type event_type, void *context),
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void *context);
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static int linux_nat_async_mask (int mask);
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static int kill_lwp (int lwpid, int signo);
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static int send_sigint_callback (struct lwp_info *lp, void *data);
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static int stop_callback (struct lwp_info *lp, void *data);
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/* Captures the result of a successful waitpid call, along with the
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options used in that call. */
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struct waitpid_result
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{
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int pid;
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int status;
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int options;
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struct waitpid_result *next;
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};
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/* A singly-linked list of the results of the waitpid calls performed
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in the async SIGCHLD handler. */
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static struct waitpid_result *waitpid_queue = NULL;
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static int
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queued_waitpid (int pid, int *status, int flags)
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{
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struct waitpid_result *msg = waitpid_queue, *prev = NULL;
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if (debug_linux_nat_async)
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fprintf_unfiltered (gdb_stdlog,
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"\
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QWPID: linux_nat_async_events_state(%d), linux_nat_num_queued_events(%d)\n",
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linux_nat_async_events_state,
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linux_nat_num_queued_events);
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if (flags & __WALL)
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{
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for (; msg; prev = msg, msg = msg->next)
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if (pid == -1 || pid == msg->pid)
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break;
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}
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else if (flags & __WCLONE)
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{
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for (; msg; prev = msg, msg = msg->next)
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if (msg->options & __WCLONE
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&& (pid == -1 || pid == msg->pid))
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break;
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}
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else
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{
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for (; msg; prev = msg, msg = msg->next)
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if ((msg->options & __WCLONE) == 0
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&& (pid == -1 || pid == msg->pid))
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break;
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}
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if (msg)
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{
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int pid;
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if (prev)
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prev->next = msg->next;
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else
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waitpid_queue = msg->next;
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msg->next = NULL;
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if (status)
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*status = msg->status;
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pid = msg->pid;
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if (debug_linux_nat_async)
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fprintf_unfiltered (gdb_stdlog, "QWPID: pid(%d), status(%x)\n",
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pid, msg->status);
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xfree (msg);
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return pid;
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||
}
|
||
|
||
if (debug_linux_nat_async)
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||
fprintf_unfiltered (gdb_stdlog, "QWPID: miss\n");
|
||
|
||
if (status)
|
||
*status = 0;
|
||
return -1;
|
||
}
|
||
|
||
static void
|
||
push_waitpid (int pid, int status, int options)
|
||
{
|
||
struct waitpid_result *event, *new_event;
|
||
|
||
new_event = xmalloc (sizeof (*new_event));
|
||
new_event->pid = pid;
|
||
new_event->status = status;
|
||
new_event->options = options;
|
||
new_event->next = NULL;
|
||
|
||
if (waitpid_queue)
|
||
{
|
||
for (event = waitpid_queue;
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||
event && event->next;
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||
event = event->next)
|
||
;
|
||
|
||
event->next = new_event;
|
||
}
|
||
else
|
||
waitpid_queue = new_event;
|
||
}
|
||
|
||
/* Drain all queued events of PID. If PID is -1, the effect is of
|
||
draining all events. */
|
||
static void
|
||
drain_queued_events (int pid)
|
||
{
|
||
while (queued_waitpid (pid, NULL, __WALL) != -1)
|
||
;
|
||
}
|
||
|
||
|
||
/* Trivial list manipulation functions to keep track of a list of
|
||
new stopped processes. */
|
||
static void
|
||
add_to_pid_list (struct simple_pid_list **listp, int pid, int status)
|
||
{
|
||
struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list));
|
||
new_pid->pid = pid;
|
||
new_pid->status = status;
|
||
new_pid->next = *listp;
|
||
*listp = new_pid;
|
||
}
|
||
|
||
static int
|
||
pull_pid_from_list (struct simple_pid_list **listp, int pid, int *status)
|
||
{
|
||
struct simple_pid_list **p;
|
||
|
||
for (p = listp; *p != NULL; p = &(*p)->next)
|
||
if ((*p)->pid == pid)
|
||
{
|
||
struct simple_pid_list *next = (*p)->next;
|
||
*status = (*p)->status;
|
||
xfree (*p);
|
||
*p = next;
|
||
return 1;
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
static void
|
||
linux_record_stopped_pid (int pid, int status)
|
||
{
|
||
add_to_pid_list (&stopped_pids, pid, status);
|
||
}
|
||
|
||
|
||
/* A helper function for linux_test_for_tracefork, called after fork (). */
|
||
|
||
static void
|
||
linux_tracefork_child (void)
|
||
{
|
||
int ret;
|
||
|
||
ptrace (PTRACE_TRACEME, 0, 0, 0);
|
||
kill (getpid (), SIGSTOP);
|
||
fork ();
|
||
_exit (0);
|
||
}
|
||
|
||
/* Wrapper function for waitpid which handles EINTR, and checks for
|
||
locally queued events. */
|
||
|
||
static int
|
||
my_waitpid (int pid, int *status, int flags)
|
||
{
|
||
int ret;
|
||
|
||
/* There should be no concurrent calls to waitpid. */
|
||
gdb_assert (linux_nat_async_events_state == sigchld_sync);
|
||
|
||
ret = queued_waitpid (pid, status, flags);
|
||
if (ret != -1)
|
||
return ret;
|
||
|
||
do
|
||
{
|
||
ret = waitpid (pid, status, flags);
|
||
}
|
||
while (ret == -1 && errno == EINTR);
|
||
|
||
return ret;
|
||
}
|
||
|
||
/* Determine if PTRACE_O_TRACEFORK can be used to follow fork events.
|
||
|
||
First, we try to enable fork tracing on ORIGINAL_PID. If this fails,
|
||
we know that the feature is not available. This may change the tracing
|
||
options for ORIGINAL_PID, but we'll be setting them shortly anyway.
|
||
|
||
However, if it succeeds, we don't know for sure that the feature is
|
||
available; old versions of PTRACE_SETOPTIONS ignored unknown options. We
|
||
create a child process, attach to it, use PTRACE_SETOPTIONS to enable
|
||
fork tracing, and let it fork. If the process exits, we assume that we
|
||
can't use TRACEFORK; if we get the fork notification, and we can extract
|
||
the new child's PID, then we assume that we can. */
|
||
|
||
static void
|
||
linux_test_for_tracefork (int original_pid)
|
||
{
|
||
int child_pid, ret, status;
|
||
long second_pid;
|
||
enum sigchld_state async_events_original_state;
|
||
|
||
async_events_original_state = linux_nat_async_events (sigchld_sync);
|
||
|
||
linux_supports_tracefork_flag = 0;
|
||
linux_supports_tracevforkdone_flag = 0;
|
||
|
||
ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACEFORK);
|
||
if (ret != 0)
|
||
return;
|
||
|
||
child_pid = fork ();
|
||
if (child_pid == -1)
|
||
perror_with_name (("fork"));
|
||
|
||
if (child_pid == 0)
|
||
linux_tracefork_child ();
|
||
|
||
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_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"));
|
||
linux_nat_async_events (async_events_original_state);
|
||
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);
|
||
|
||
linux_nat_async_events (async_events_original_state);
|
||
return;
|
||
}
|
||
|
||
/* Check whether PTRACE_O_TRACEVFORKDONE is available. */
|
||
ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0,
|
||
PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORKDONE);
|
||
linux_supports_tracevforkdone_flag = (ret == 0);
|
||
|
||
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);
|
||
|
||
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);
|
||
|
||
linux_nat_async_events (async_events_original_state);
|
||
}
|
||
|
||
/* Return non-zero iff we have tracefork functionality available.
|
||
This function also sets linux_supports_tracefork_flag. */
|
||
|
||
static int
|
||
linux_supports_tracefork (int pid)
|
||
{
|
||
if (linux_supports_tracefork_flag == -1)
|
||
linux_test_for_tracefork (pid);
|
||
return linux_supports_tracefork_flag;
|
||
}
|
||
|
||
static int
|
||
linux_supports_tracevforkdone (int pid)
|
||
{
|
||
if (linux_supports_tracefork_flag == -1)
|
||
linux_test_for_tracefork (pid);
|
||
return linux_supports_tracevforkdone_flag;
|
||
}
|
||
|
||
|
||
void
|
||
linux_enable_event_reporting (ptid_t ptid)
|
||
{
|
||
int pid = ptid_get_lwp (ptid);
|
||
int options;
|
||
|
||
if (pid == 0)
|
||
pid = ptid_get_pid (ptid);
|
||
|
||
if (! linux_supports_tracefork (pid))
|
||
return;
|
||
|
||
options = PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK | PTRACE_O_TRACEEXEC
|
||
| PTRACE_O_TRACECLONE;
|
||
if (linux_supports_tracevforkdone (pid))
|
||
options |= PTRACE_O_TRACEVFORKDONE;
|
||
|
||
/* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support
|
||
read-only process state. */
|
||
|
||
ptrace (PTRACE_SETOPTIONS, pid, 0, options);
|
||
}
|
||
|
||
static void
|
||
linux_child_post_attach (int pid)
|
||
{
|
||
linux_enable_event_reporting (pid_to_ptid (pid));
|
||
check_for_thread_db ();
|
||
}
|
||
|
||
static void
|
||
linux_child_post_startup_inferior (ptid_t ptid)
|
||
{
|
||
linux_enable_event_reporting (ptid);
|
||
check_for_thread_db ();
|
||
}
|
||
|
||
static int
|
||
linux_child_follow_fork (struct target_ops *ops, int follow_child)
|
||
{
|
||
ptid_t last_ptid;
|
||
struct target_waitstatus last_status;
|
||
int has_vforked;
|
||
int parent_pid, child_pid;
|
||
|
||
if (target_can_async_p ())
|
||
target_async (NULL, 0);
|
||
|
||
get_last_target_status (&last_ptid, &last_status);
|
||
has_vforked = (last_status.kind == TARGET_WAITKIND_VFORKED);
|
||
parent_pid = ptid_get_lwp (last_ptid);
|
||
if (parent_pid == 0)
|
||
parent_pid = ptid_get_pid (last_ptid);
|
||
child_pid = PIDGET (last_status.value.related_pid);
|
||
|
||
if (! follow_child)
|
||
{
|
||
/* We're already attached to the parent, by default. */
|
||
|
||
/* Before detaching from the child, remove all breakpoints from
|
||
it. (This won't actually modify the breakpoint list, but will
|
||
physically remove the breakpoints from the child.) */
|
||
/* If we vforked this will remove the breakpoints from the parent
|
||
also, but they'll be reinserted below. */
|
||
detach_breakpoints (child_pid);
|
||
|
||
/* Detach new forked process? */
|
||
if (detach_fork)
|
||
{
|
||
if (info_verbose || debug_linux_nat)
|
||
{
|
||
target_terminal_ours ();
|
||
fprintf_filtered (gdb_stdlog,
|
||
"Detaching after fork from child process %d.\n",
|
||
child_pid);
|
||
}
|
||
|
||
ptrace (PTRACE_DETACH, child_pid, 0, 0);
|
||
}
|
||
else
|
||
{
|
||
struct fork_info *fp;
|
||
/* Retain child fork in ptrace (stopped) state. */
|
||
fp = find_fork_pid (child_pid);
|
||
if (!fp)
|
||
fp = add_fork (child_pid);
|
||
fork_save_infrun_state (fp, 0);
|
||
}
|
||
|
||
if (has_vforked)
|
||
{
|
||
gdb_assert (linux_supports_tracefork_flag >= 0);
|
||
if (linux_supports_tracevforkdone (0))
|
||
{
|
||
int status;
|
||
|
||
ptrace (PTRACE_CONT, parent_pid, 0, 0);
|
||
my_waitpid (parent_pid, &status, __WALL);
|
||
if ((status >> 16) != PTRACE_EVENT_VFORK_DONE)
|
||
warning (_("Unexpected waitpid result %06x when waiting for "
|
||
"vfork-done"), status);
|
||
}
|
||
else
|
||
{
|
||
/* We can't insert breakpoints until the child has
|
||
finished with the shared memory region. We need to
|
||
wait until that happens. Ideal would be to just
|
||
call:
|
||
- ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
|
||
- waitpid (parent_pid, &status, __WALL);
|
||
However, most architectures can't handle a syscall
|
||
being traced on the way out if it wasn't traced on
|
||
the way in.
|
||
|
||
We might also think to loop, continuing the child
|
||
until it exits or gets a SIGTRAP. One problem is
|
||
that the child might call ptrace with PTRACE_TRACEME.
|
||
|
||
There's no simple and reliable way to figure out when
|
||
the vforked child will be done with its copy of the
|
||
shared memory. We could step it out of the syscall,
|
||
two instructions, let it go, and then single-step the
|
||
parent once. When we have hardware single-step, this
|
||
would work; with software single-step it could still
|
||
be made to work but we'd have to be able to insert
|
||
single-step breakpoints in the child, and we'd have
|
||
to insert -just- the single-step breakpoint in the
|
||
parent. Very awkward.
|
||
|
||
In the end, the best we can do is to make sure it
|
||
runs for a little while. Hopefully it will be out of
|
||
range of any breakpoints we reinsert. Usually this
|
||
is only the single-step breakpoint at vfork's return
|
||
point. */
|
||
|
||
usleep (10000);
|
||
}
|
||
|
||
/* Since we vforked, breakpoints were removed in the parent
|
||
too. Put them back. */
|
||
reattach_breakpoints (parent_pid);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
char child_pid_spelling[40];
|
||
|
||
/* Needed to keep the breakpoint lists in sync. */
|
||
if (! has_vforked)
|
||
detach_breakpoints (child_pid);
|
||
|
||
/* Before detaching from the parent, remove all breakpoints from it. */
|
||
remove_breakpoints ();
|
||
|
||
if (info_verbose || debug_linux_nat)
|
||
{
|
||
target_terminal_ours ();
|
||
fprintf_filtered (gdb_stdlog,
|
||
"Attaching after fork to child process %d.\n",
|
||
child_pid);
|
||
}
|
||
|
||
/* If we're vforking, we may want to hold on to the parent until
|
||
the child exits or execs. At exec time we can remove the old
|
||
breakpoints from the parent and detach it; at exit time we
|
||
could do the same (or even, sneakily, resume debugging it - the
|
||
child's exec has failed, or something similar).
|
||
|
||
This doesn't clean up "properly", because we can't call
|
||
target_detach, but that's OK; if the current target is "child",
|
||
then it doesn't need any further cleanups, and lin_lwp will
|
||
generally not encounter vfork (vfork is defined to fork
|
||
in libpthread.so).
|
||
|
||
The holding part is very easy if we have VFORKDONE events;
|
||
but keeping track of both processes is beyond GDB at the
|
||
moment. So we don't expose the parent to the rest of GDB.
|
||
Instead we quietly hold onto it until such time as we can
|
||
safely resume it. */
|
||
|
||
if (has_vforked)
|
||
linux_parent_pid = parent_pid;
|
||
else if (!detach_fork)
|
||
{
|
||
struct fork_info *fp;
|
||
/* Retain parent fork in ptrace (stopped) state. */
|
||
fp = find_fork_pid (parent_pid);
|
||
if (!fp)
|
||
fp = add_fork (parent_pid);
|
||
fork_save_infrun_state (fp, 0);
|
||
}
|
||
else
|
||
target_detach (NULL, 0);
|
||
|
||
inferior_ptid = ptid_build (child_pid, child_pid, 0);
|
||
|
||
/* Reinstall ourselves, since we might have been removed in
|
||
target_detach (which does other necessary cleanup). */
|
||
|
||
push_target (ops);
|
||
linux_nat_switch_fork (inferior_ptid);
|
||
check_for_thread_db ();
|
||
|
||
/* Reset breakpoints in the child as appropriate. */
|
||
follow_inferior_reset_breakpoints ();
|
||
}
|
||
|
||
if (target_can_async_p ())
|
||
target_async (inferior_event_handler, 0);
|
||
|
||
return 0;
|
||
}
|
||
|
||
|
||
static void
|
||
linux_child_insert_fork_catchpoint (int pid)
|
||
{
|
||
if (! linux_supports_tracefork (pid))
|
||
error (_("Your system does not support fork catchpoints."));
|
||
}
|
||
|
||
static void
|
||
linux_child_insert_vfork_catchpoint (int pid)
|
||
{
|
||
if (!linux_supports_tracefork (pid))
|
||
error (_("Your system does not support vfork catchpoints."));
|
||
}
|
||
|
||
static void
|
||
linux_child_insert_exec_catchpoint (int pid)
|
||
{
|
||
if (!linux_supports_tracefork (pid))
|
||
error (_("Your system does not support exec catchpoints."));
|
||
}
|
||
|
||
/* On GNU/Linux there are no real LWP's. The closest thing to LWP's
|
||
are processes sharing the same VM space. A multi-threaded process
|
||
is basically a group of such processes. However, such a grouping
|
||
is almost entirely a user-space issue; the kernel doesn't enforce
|
||
such a grouping at all (this might change in the future). In
|
||
general, we'll rely on the threads library (i.e. the GNU/Linux
|
||
Threads library) to provide such a grouping.
|
||
|
||
It is perfectly well possible to write a multi-threaded application
|
||
without the assistance of a threads library, by using the clone
|
||
system call directly. This module should be able to give some
|
||
rudimentary support for debugging such applications if developers
|
||
specify the CLONE_PTRACE flag in the clone system call, and are
|
||
using the Linux kernel 2.4 or above.
|
||
|
||
Note that there are some peculiarities in GNU/Linux that affect
|
||
this code:
|
||
|
||
- In general one should specify the __WCLONE flag to waitpid in
|
||
order to make it report events for any of the cloned processes
|
||
(and leave it out for the initial process). However, if a cloned
|
||
process has exited the exit status is only reported if the
|
||
__WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
|
||
we cannot use it since GDB must work on older systems too.
|
||
|
||
- When a traced, cloned process exits and is waited for by the
|
||
debugger, the kernel reassigns it to the original parent and
|
||
keeps it around as a "zombie". Somehow, the GNU/Linux Threads
|
||
library doesn't notice this, which leads to the "zombie problem":
|
||
When debugged a multi-threaded process that spawns a lot of
|
||
threads will run out of processes, even if the threads exit,
|
||
because the "zombies" stay around. */
|
||
|
||
/* List of known LWPs. */
|
||
struct lwp_info *lwp_list;
|
||
|
||
/* Number of LWPs in the list. */
|
||
static int num_lwps;
|
||
|
||
|
||
/* Original signal mask. */
|
||
static sigset_t normal_mask;
|
||
|
||
/* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
|
||
_initialize_linux_nat. */
|
||
static sigset_t suspend_mask;
|
||
|
||
/* SIGCHLD action for synchronous mode. */
|
||
struct sigaction sync_sigchld_action;
|
||
|
||
/* SIGCHLD action for asynchronous mode. */
|
||
static struct sigaction async_sigchld_action;
|
||
|
||
/* SIGCHLD default action, to pass to new inferiors. */
|
||
static struct sigaction sigchld_default_action;
|
||
|
||
|
||
/* Prototypes for local functions. */
|
||
static int stop_wait_callback (struct lwp_info *lp, void *data);
|
||
static int linux_nat_thread_alive (ptid_t ptid);
|
||
static char *linux_child_pid_to_exec_file (int pid);
|
||
static int cancel_breakpoint (struct lwp_info *lp);
|
||
|
||
|
||
/* Convert wait status STATUS to a string. Used for printing debug
|
||
messages only. */
|
||
|
||
static char *
|
||
status_to_str (int status)
|
||
{
|
||
static char buf[64];
|
||
|
||
if (WIFSTOPPED (status))
|
||
snprintf (buf, sizeof (buf), "%s (stopped)",
|
||
strsignal (WSTOPSIG (status)));
|
||
else if (WIFSIGNALED (status))
|
||
snprintf (buf, sizeof (buf), "%s (terminated)",
|
||
strsignal (WSTOPSIG (status)));
|
||
else
|
||
snprintf (buf, sizeof (buf), "%d (exited)", WEXITSTATUS (status));
|
||
|
||
return buf;
|
||
}
|
||
|
||
/* Initialize the list of LWPs. Note that this module, contrary to
|
||
what GDB's generic threads layer does for its thread list,
|
||
re-initializes the LWP lists whenever we mourn or detach (which
|
||
doesn't involve mourning) the inferior. */
|
||
|
||
static void
|
||
init_lwp_list (void)
|
||
{
|
||
struct lwp_info *lp, *lpnext;
|
||
|
||
for (lp = lwp_list; lp; lp = lpnext)
|
||
{
|
||
lpnext = lp->next;
|
||
xfree (lp);
|
||
}
|
||
|
||
lwp_list = NULL;
|
||
num_lwps = 0;
|
||
}
|
||
|
||
/* Add the LWP specified by PID to the list. Return a pointer to the
|
||
structure describing the new LWP. The LWP should already be stopped
|
||
(with an exception for the very first LWP). */
|
||
|
||
static struct lwp_info *
|
||
add_lwp (ptid_t ptid)
|
||
{
|
||
struct lwp_info *lp;
|
||
|
||
gdb_assert (is_lwp (ptid));
|
||
|
||
lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info));
|
||
|
||
memset (lp, 0, sizeof (struct lwp_info));
|
||
|
||
lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
|
||
|
||
lp->ptid = ptid;
|
||
|
||
lp->next = lwp_list;
|
||
lwp_list = lp;
|
||
++num_lwps;
|
||
|
||
if (num_lwps > 1 && linux_nat_new_thread != NULL)
|
||
linux_nat_new_thread (ptid);
|
||
|
||
return lp;
|
||
}
|
||
|
||
/* Remove the LWP specified by PID from the list. */
|
||
|
||
static void
|
||
delete_lwp (ptid_t ptid)
|
||
{
|
||
struct lwp_info *lp, *lpprev;
|
||
|
||
lpprev = NULL;
|
||
|
||
for (lp = lwp_list; lp; lpprev = lp, lp = lp->next)
|
||
if (ptid_equal (lp->ptid, ptid))
|
||
break;
|
||
|
||
if (!lp)
|
||
return;
|
||
|
||
num_lwps--;
|
||
|
||
if (lpprev)
|
||
lpprev->next = lp->next;
|
||
else
|
||
lwp_list = lp->next;
|
||
|
||
xfree (lp);
|
||
}
|
||
|
||
/* Return a pointer to the structure describing the LWP corresponding
|
||
to PID. If no corresponding LWP could be found, return NULL. */
|
||
|
||
static struct lwp_info *
|
||
find_lwp_pid (ptid_t ptid)
|
||
{
|
||
struct lwp_info *lp;
|
||
int lwp;
|
||
|
||
if (is_lwp (ptid))
|
||
lwp = GET_LWP (ptid);
|
||
else
|
||
lwp = GET_PID (ptid);
|
||
|
||
for (lp = lwp_list; lp; lp = lp->next)
|
||
if (lwp == GET_LWP (lp->ptid))
|
||
return lp;
|
||
|
||
return NULL;
|
||
}
|
||
|
||
/* Call CALLBACK with its second argument set to DATA for every LWP in
|
||
the list. If CALLBACK returns 1 for a particular LWP, return a
|
||
pointer to the structure describing that LWP immediately.
|
||
Otherwise return NULL. */
|
||
|
||
struct lwp_info *
|
||
iterate_over_lwps (int (*callback) (struct lwp_info *, void *), void *data)
|
||
{
|
||
struct lwp_info *lp, *lpnext;
|
||
|
||
for (lp = lwp_list; lp; lp = lpnext)
|
||
{
|
||
lpnext = lp->next;
|
||
if ((*callback) (lp, data))
|
||
return lp;
|
||
}
|
||
|
||
return NULL;
|
||
}
|
||
|
||
/* Update our internal state when changing from one fork (checkpoint,
|
||
et cetera) to another indicated by NEW_PTID. We can only switch
|
||
single-threaded applications, so we only create one new LWP, and
|
||
the previous list is discarded. */
|
||
|
||
void
|
||
linux_nat_switch_fork (ptid_t new_ptid)
|
||
{
|
||
struct lwp_info *lp;
|
||
|
||
init_lwp_list ();
|
||
lp = add_lwp (new_ptid);
|
||
lp->stopped = 1;
|
||
|
||
init_thread_list ();
|
||
add_thread_silent (new_ptid);
|
||
}
|
||
|
||
/* Handle the exit of a single thread LP. */
|
||
|
||
static void
|
||
exit_lwp (struct lwp_info *lp)
|
||
{
|
||
struct thread_info *th = find_thread_pid (lp->ptid);
|
||
|
||
if (th)
|
||
{
|
||
if (print_thread_events)
|
||
printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid));
|
||
|
||
delete_thread (lp->ptid);
|
||
}
|
||
|
||
delete_lwp (lp->ptid);
|
||
}
|
||
|
||
/* Detect `T (stopped)' in `/proc/PID/status'.
|
||
Other states including `T (tracing stop)' are reported as false. */
|
||
|
||
static int
|
||
pid_is_stopped (pid_t pid)
|
||
{
|
||
FILE *status_file;
|
||
char buf[100];
|
||
int retval = 0;
|
||
|
||
snprintf (buf, sizeof (buf), "/proc/%d/status", (int) pid);
|
||
status_file = fopen (buf, "r");
|
||
if (status_file != NULL)
|
||
{
|
||
int have_state = 0;
|
||
|
||
while (fgets (buf, sizeof (buf), status_file))
|
||
{
|
||
if (strncmp (buf, "State:", 6) == 0)
|
||
{
|
||
have_state = 1;
|
||
break;
|
||
}
|
||
}
|
||
if (have_state && strstr (buf, "T (stopped)") != NULL)
|
||
retval = 1;
|
||
fclose (status_file);
|
||
}
|
||
return retval;
|
||
}
|
||
|
||
/* Wait for the LWP specified by LP, which we have just attached to.
|
||
Returns a wait status for that LWP, to cache. */
|
||
|
||
static int
|
||
linux_nat_post_attach_wait (ptid_t ptid, int first, int *cloned,
|
||
int *signalled)
|
||
{
|
||
pid_t new_pid, pid = GET_LWP (ptid);
|
||
int status;
|
||
|
||
if (pid_is_stopped (pid))
|
||
{
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LNPAW: Attaching to a stopped process\n");
|
||
|
||
/* The process is definitely stopped. It is in a job control
|
||
stop, unless the kernel predates the TASK_STOPPED /
|
||
TASK_TRACED distinction, in which case it might be in a
|
||
ptrace stop. Make sure it is in a ptrace stop; from there we
|
||
can kill it, signal it, et cetera.
|
||
|
||
First make sure there is a pending SIGSTOP. Since we are
|
||
already attached, the process can not transition from stopped
|
||
to running without a PTRACE_CONT; so we know this signal will
|
||
go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
|
||
probably already in the queue (unless this kernel is old
|
||
enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
|
||
is not an RT signal, it can only be queued once. */
|
||
kill_lwp (pid, SIGSTOP);
|
||
|
||
/* Finally, resume the stopped process. This will deliver the SIGSTOP
|
||
(or a higher priority signal, just like normal PTRACE_ATTACH). */
|
||
ptrace (PTRACE_CONT, pid, 0, 0);
|
||
}
|
||
|
||
/* Make sure the initial process is stopped. The user-level threads
|
||
layer might want to poke around in the inferior, and that won't
|
||
work if things haven't stabilized yet. */
|
||
new_pid = my_waitpid (pid, &status, 0);
|
||
if (new_pid == -1 && errno == ECHILD)
|
||
{
|
||
if (first)
|
||
warning (_("%s is a cloned process"), target_pid_to_str (ptid));
|
||
|
||
/* Try again with __WCLONE to check cloned processes. */
|
||
new_pid = my_waitpid (pid, &status, __WCLONE);
|
||
*cloned = 1;
|
||
}
|
||
|
||
gdb_assert (pid == new_pid && WIFSTOPPED (status));
|
||
|
||
if (WSTOPSIG (status) != SIGSTOP)
|
||
{
|
||
*signalled = 1;
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LNPAW: Received %s after attaching\n",
|
||
status_to_str (status));
|
||
}
|
||
|
||
return status;
|
||
}
|
||
|
||
/* Attach to the LWP specified by PID. Return 0 if successful or -1
|
||
if the new LWP could not be attached. */
|
||
|
||
int
|
||
lin_lwp_attach_lwp (ptid_t ptid)
|
||
{
|
||
struct lwp_info *lp;
|
||
enum sigchld_state async_events_original_state;
|
||
|
||
gdb_assert (is_lwp (ptid));
|
||
|
||
async_events_original_state = linux_nat_async_events (sigchld_sync);
|
||
|
||
lp = find_lwp_pid (ptid);
|
||
|
||
/* We assume that we're already attached to any LWP that has an id
|
||
equal to the overall process id, and to any LWP that is already
|
||
in our list of LWPs. If we're not seeing exit events from threads
|
||
and we've had PID wraparound since we last tried to stop all threads,
|
||
this assumption might be wrong; fortunately, this is very unlikely
|
||
to happen. */
|
||
if (GET_LWP (ptid) != GET_PID (ptid) && lp == NULL)
|
||
{
|
||
int status, cloned = 0, signalled = 0;
|
||
|
||
if (ptrace (PTRACE_ATTACH, GET_LWP (ptid), 0, 0) < 0)
|
||
{
|
||
/* If we fail to attach to the thread, issue a warning,
|
||
but continue. One way this can happen is if thread
|
||
creation is interrupted; as of Linux kernel 2.6.19, a
|
||
bug may place threads in the thread list and then fail
|
||
to create them. */
|
||
warning (_("Can't attach %s: %s"), target_pid_to_str (ptid),
|
||
safe_strerror (errno));
|
||
return -1;
|
||
}
|
||
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
|
||
target_pid_to_str (ptid));
|
||
|
||
status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled);
|
||
lp = add_lwp (ptid);
|
||
lp->stopped = 1;
|
||
lp->cloned = cloned;
|
||
lp->signalled = signalled;
|
||
if (WSTOPSIG (status) != SIGSTOP)
|
||
{
|
||
lp->resumed = 1;
|
||
lp->status = status;
|
||
}
|
||
|
||
target_post_attach (GET_LWP (lp->ptid));
|
||
|
||
if (debug_linux_nat)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLAL: waitpid %s received %s\n",
|
||
target_pid_to_str (ptid),
|
||
status_to_str (status));
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* We assume that the LWP representing the original process is
|
||
already stopped. Mark it as stopped in the data structure
|
||
that the GNU/linux ptrace layer uses to keep track of
|
||
threads. Note that this won't have already been done since
|
||
the main thread will have, we assume, been stopped by an
|
||
attach from a different layer. */
|
||
if (lp == NULL)
|
||
lp = add_lwp (ptid);
|
||
lp->stopped = 1;
|
||
}
|
||
|
||
linux_nat_async_events (async_events_original_state);
|
||
return 0;
|
||
}
|
||
|
||
static void
|
||
linux_nat_create_inferior (char *exec_file, char *allargs, char **env,
|
||
int from_tty)
|
||
{
|
||
int saved_async = 0;
|
||
#ifdef HAVE_PERSONALITY
|
||
int personality_orig = 0, personality_set = 0;
|
||
#endif /* HAVE_PERSONALITY */
|
||
|
||
/* The fork_child mechanism is synchronous and calls target_wait, so
|
||
we have to mask the async mode. */
|
||
|
||
if (target_can_async_p ())
|
||
/* Mask async mode. Creating a child requires a loop calling
|
||
wait_for_inferior currently. */
|
||
saved_async = linux_nat_async_mask (0);
|
||
else
|
||
{
|
||
/* Restore the original signal mask. */
|
||
sigprocmask (SIG_SETMASK, &normal_mask, NULL);
|
||
/* Make sure we don't block SIGCHLD during a sigsuspend. */
|
||
suspend_mask = normal_mask;
|
||
sigdelset (&suspend_mask, SIGCHLD);
|
||
}
|
||
|
||
/* Set SIGCHLD to the default action, until after execing the child,
|
||
since the inferior inherits the superior's signal mask. It will
|
||
be blocked again in linux_nat_wait, which is only reached after
|
||
the inferior execing. */
|
||
linux_nat_async_events (sigchld_default);
|
||
|
||
#ifdef HAVE_PERSONALITY
|
||
if (disable_randomization)
|
||
{
|
||
errno = 0;
|
||
personality_orig = personality (0xffffffff);
|
||
if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE))
|
||
{
|
||
personality_set = 1;
|
||
personality (personality_orig | ADDR_NO_RANDOMIZE);
|
||
}
|
||
if (errno != 0 || (personality_set
|
||
&& !(personality (0xffffffff) & ADDR_NO_RANDOMIZE)))
|
||
warning (_("Error disabling address space randomization: %s"),
|
||
safe_strerror (errno));
|
||
}
|
||
#endif /* HAVE_PERSONALITY */
|
||
|
||
linux_ops->to_create_inferior (exec_file, allargs, env, from_tty);
|
||
|
||
#ifdef HAVE_PERSONALITY
|
||
if (personality_set)
|
||
{
|
||
errno = 0;
|
||
personality (personality_orig);
|
||
if (errno != 0)
|
||
warning (_("Error restoring address space randomization: %s"),
|
||
safe_strerror (errno));
|
||
}
|
||
#endif /* HAVE_PERSONALITY */
|
||
|
||
if (saved_async)
|
||
linux_nat_async_mask (saved_async);
|
||
}
|
||
|
||
static void
|
||
linux_nat_attach (char *args, int from_tty)
|
||
{
|
||
struct lwp_info *lp;
|
||
int status;
|
||
ptid_t ptid;
|
||
|
||
/* FIXME: We should probably accept a list of process id's, and
|
||
attach all of them. */
|
||
linux_ops->to_attach (args, from_tty);
|
||
|
||
if (!target_can_async_p ())
|
||
{
|
||
/* Restore the original signal mask. */
|
||
sigprocmask (SIG_SETMASK, &normal_mask, NULL);
|
||
/* Make sure we don't block SIGCHLD during a sigsuspend. */
|
||
suspend_mask = normal_mask;
|
||
sigdelset (&suspend_mask, SIGCHLD);
|
||
}
|
||
|
||
/* The ptrace base target adds the main thread with (pid,0,0)
|
||
format. Decorate it with lwp info. */
|
||
ptid = BUILD_LWP (GET_PID (inferior_ptid), GET_PID (inferior_ptid));
|
||
thread_change_ptid (inferior_ptid, ptid);
|
||
|
||
/* Add the initial process as the first LWP to the list. */
|
||
lp = add_lwp (ptid);
|
||
|
||
status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->cloned,
|
||
&lp->signalled);
|
||
lp->stopped = 1;
|
||
|
||
/* Save the wait status to report later. */
|
||
lp->resumed = 1;
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LNA: waitpid %ld, saving status %s\n",
|
||
(long) GET_PID (lp->ptid), status_to_str (status));
|
||
|
||
if (!target_can_async_p ())
|
||
lp->status = status;
|
||
else
|
||
{
|
||
/* We already waited for this LWP, so put the wait result on the
|
||
pipe. The event loop will wake up and gets us to handling
|
||
this event. */
|
||
linux_nat_event_pipe_push (GET_PID (lp->ptid), status,
|
||
lp->cloned ? __WCLONE : 0);
|
||
/* Register in the event loop. */
|
||
target_async (inferior_event_handler, 0);
|
||
}
|
||
}
|
||
|
||
/* Get pending status of LP. */
|
||
static int
|
||
get_pending_status (struct lwp_info *lp, int *status)
|
||
{
|
||
struct target_waitstatus last;
|
||
ptid_t last_ptid;
|
||
|
||
get_last_target_status (&last_ptid, &last);
|
||
|
||
/* If this lwp is the ptid that GDB is processing an event from, the
|
||
signal will be in stop_signal. Otherwise, in all-stop + sync
|
||
mode, we may cache pending events in lp->status while trying to
|
||
stop all threads (see stop_wait_callback). In async mode, the
|
||
events are always cached in waitpid_queue. */
|
||
|
||
*status = 0;
|
||
|
||
if (non_stop)
|
||
{
|
||
enum target_signal signo = TARGET_SIGNAL_0;
|
||
|
||
if (is_executing (lp->ptid))
|
||
{
|
||
/* If the core thought this lwp was executing --- e.g., the
|
||
executing property hasn't been updated yet, but the
|
||
thread has been stopped with a stop_callback /
|
||
stop_wait_callback sequence (see linux_nat_detach for
|
||
example) --- we can only have pending events in the local
|
||
queue. */
|
||
if (queued_waitpid (GET_LWP (lp->ptid), status, __WALL) != -1)
|
||
{
|
||
if (WIFSTOPPED (status))
|
||
signo = target_signal_from_host (WSTOPSIG (status));
|
||
|
||
/* If not stopped, then the lwp is gone, no use in
|
||
resending a signal. */
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* If the core knows the thread is not executing, then we
|
||
have the last signal recorded in
|
||
thread_info->stop_signal, unless this is inferior_ptid,
|
||
in which case, it's in the global stop_signal, due to
|
||
context switching. */
|
||
|
||
if (ptid_equal (lp->ptid, inferior_ptid))
|
||
signo = stop_signal;
|
||
else
|
||
{
|
||
struct thread_info *tp = find_thread_pid (lp->ptid);
|
||
gdb_assert (tp);
|
||
signo = tp->stop_signal;
|
||
}
|
||
}
|
||
|
||
if (signo != TARGET_SIGNAL_0
|
||
&& !signal_pass_state (signo))
|
||
{
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog, "\
|
||
GPT: lwp %s had signal %s, but it is in no pass state\n",
|
||
target_pid_to_str (lp->ptid),
|
||
target_signal_to_string (signo));
|
||
}
|
||
else
|
||
{
|
||
if (signo != TARGET_SIGNAL_0)
|
||
*status = W_STOPCODE (target_signal_to_host (signo));
|
||
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"GPT: lwp %s as pending signal %s\n",
|
||
target_pid_to_str (lp->ptid),
|
||
target_signal_to_string (signo));
|
||
}
|
||
}
|
||
else
|
||
{
|
||
if (GET_LWP (lp->ptid) == GET_LWP (last_ptid))
|
||
{
|
||
if (stop_signal != TARGET_SIGNAL_0
|
||
&& signal_pass_state (stop_signal))
|
||
*status = W_STOPCODE (target_signal_to_host (stop_signal));
|
||
}
|
||
else if (target_can_async_p ())
|
||
queued_waitpid (GET_LWP (lp->ptid), status, __WALL);
|
||
else
|
||
*status = lp->status;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
static int
|
||
detach_callback (struct lwp_info *lp, void *data)
|
||
{
|
||
gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status));
|
||
|
||
if (debug_linux_nat && lp->status)
|
||
fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n",
|
||
strsignal (WSTOPSIG (lp->status)),
|
||
target_pid_to_str (lp->ptid));
|
||
|
||
/* If there is a pending SIGSTOP, get rid of it. */
|
||
if (lp->signalled)
|
||
{
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"DC: Sending SIGCONT to %s\n",
|
||
target_pid_to_str (lp->ptid));
|
||
|
||
kill_lwp (GET_LWP (lp->ptid), SIGCONT);
|
||
lp->signalled = 0;
|
||
}
|
||
|
||
/* We don't actually detach from the LWP that has an id equal to the
|
||
overall process id just yet. */
|
||
if (GET_LWP (lp->ptid) != GET_PID (lp->ptid))
|
||
{
|
||
int status = 0;
|
||
|
||
/* Pass on any pending signal for this LWP. */
|
||
get_pending_status (lp, &status);
|
||
|
||
errno = 0;
|
||
if (ptrace (PTRACE_DETACH, GET_LWP (lp->ptid), 0,
|
||
WSTOPSIG (status)) < 0)
|
||
error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid),
|
||
safe_strerror (errno));
|
||
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"PTRACE_DETACH (%s, %s, 0) (OK)\n",
|
||
target_pid_to_str (lp->ptid),
|
||
strsignal (WSTOPSIG (lp->status)));
|
||
|
||
delete_lwp (lp->ptid);
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
static void
|
||
linux_nat_detach (char *args, int from_tty)
|
||
{
|
||
int pid;
|
||
int status;
|
||
enum target_signal sig;
|
||
|
||
if (target_can_async_p ())
|
||
linux_nat_async (NULL, 0);
|
||
|
||
/* Stop all threads before detaching. ptrace requires that the
|
||
thread is stopped to sucessfully detach. */
|
||
iterate_over_lwps (stop_callback, NULL);
|
||
/* ... and wait until all of them have reported back that
|
||
they're no longer running. */
|
||
iterate_over_lwps (stop_wait_callback, NULL);
|
||
|
||
iterate_over_lwps (detach_callback, NULL);
|
||
|
||
/* Only the initial process should be left right now. */
|
||
gdb_assert (num_lwps == 1);
|
||
|
||
/* Pass on any pending signal for the last LWP. */
|
||
if ((args == NULL || *args == '\0')
|
||
&& get_pending_status (lwp_list, &status) != -1
|
||
&& WIFSTOPPED (status))
|
||
{
|
||
/* Put the signal number in ARGS so that inf_ptrace_detach will
|
||
pass it along with PTRACE_DETACH. */
|
||
args = alloca (8);
|
||
sprintf (args, "%d", (int) WSTOPSIG (status));
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LND: Sending signal %s to %s\n",
|
||
args,
|
||
target_pid_to_str (lwp_list->ptid));
|
||
}
|
||
|
||
/* Destroy LWP info; it's no longer valid. */
|
||
init_lwp_list ();
|
||
|
||
pid = GET_PID (inferior_ptid);
|
||
inferior_ptid = pid_to_ptid (pid);
|
||
linux_ops->to_detach (args, from_tty);
|
||
|
||
if (target_can_async_p ())
|
||
drain_queued_events (pid);
|
||
}
|
||
|
||
/* Resume LP. */
|
||
|
||
static int
|
||
resume_callback (struct lwp_info *lp, void *data)
|
||
{
|
||
if (lp->stopped && lp->status == 0)
|
||
{
|
||
linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)),
|
||
0, TARGET_SIGNAL_0);
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"RC: PTRACE_CONT %s, 0, 0 (resume sibling)\n",
|
||
target_pid_to_str (lp->ptid));
|
||
lp->stopped = 0;
|
||
lp->step = 0;
|
||
memset (&lp->siginfo, 0, sizeof (lp->siginfo));
|
||
}
|
||
else if (lp->stopped && debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog, "RC: Not resuming sibling %s (has pending)\n",
|
||
target_pid_to_str (lp->ptid));
|
||
else if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog, "RC: Not resuming sibling %s (not stopped)\n",
|
||
target_pid_to_str (lp->ptid));
|
||
|
||
return 0;
|
||
}
|
||
|
||
static int
|
||
resume_clear_callback (struct lwp_info *lp, void *data)
|
||
{
|
||
lp->resumed = 0;
|
||
return 0;
|
||
}
|
||
|
||
static int
|
||
resume_set_callback (struct lwp_info *lp, void *data)
|
||
{
|
||
lp->resumed = 1;
|
||
return 0;
|
||
}
|
||
|
||
static void
|
||
linux_nat_resume (ptid_t ptid, int step, enum target_signal signo)
|
||
{
|
||
struct lwp_info *lp;
|
||
int resume_all;
|
||
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
|
||
step ? "step" : "resume",
|
||
target_pid_to_str (ptid),
|
||
signo ? strsignal (signo) : "0",
|
||
target_pid_to_str (inferior_ptid));
|
||
|
||
if (target_can_async_p ())
|
||
/* Block events while we're here. */
|
||
linux_nat_async_events (sigchld_sync);
|
||
|
||
/* A specific PTID means `step only this process id'. */
|
||
resume_all = (PIDGET (ptid) == -1);
|
||
|
||
if (non_stop && resume_all)
|
||
internal_error (__FILE__, __LINE__,
|
||
"can't resume all in non-stop mode");
|
||
|
||
if (!non_stop)
|
||
{
|
||
if (resume_all)
|
||
iterate_over_lwps (resume_set_callback, NULL);
|
||
else
|
||
iterate_over_lwps (resume_clear_callback, NULL);
|
||
}
|
||
|
||
/* If PID is -1, it's the current inferior that should be
|
||
handled specially. */
|
||
if (PIDGET (ptid) == -1)
|
||
ptid = inferior_ptid;
|
||
|
||
lp = find_lwp_pid (ptid);
|
||
gdb_assert (lp != NULL);
|
||
|
||
/* Convert to something the lower layer understands. */
|
||
ptid = pid_to_ptid (GET_LWP (lp->ptid));
|
||
|
||
/* Remember if we're stepping. */
|
||
lp->step = step;
|
||
|
||
/* Mark this LWP as resumed. */
|
||
lp->resumed = 1;
|
||
|
||
/* If we have a pending wait status for this thread, there is no
|
||
point in resuming the process. But first make sure that
|
||
linux_nat_wait won't preemptively handle the event - we
|
||
should never take this short-circuit if we are going to
|
||
leave LP running, since we have skipped resuming all the
|
||
other threads. This bit of code needs to be synchronized
|
||
with linux_nat_wait. */
|
||
|
||
/* In async mode, we never have pending wait status. */
|
||
if (target_can_async_p () && lp->status)
|
||
internal_error (__FILE__, __LINE__, "Pending status in async mode");
|
||
|
||
if (lp->status && WIFSTOPPED (lp->status))
|
||
{
|
||
int saved_signo = target_signal_from_host (WSTOPSIG (lp->status));
|
||
|
||
if (signal_stop_state (saved_signo) == 0
|
||
&& signal_print_state (saved_signo) == 0
|
||
&& signal_pass_state (saved_signo) == 1)
|
||
{
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLR: Not short circuiting for ignored "
|
||
"status 0x%x\n", lp->status);
|
||
|
||
/* FIXME: What should we do if we are supposed to continue
|
||
this thread with a signal? */
|
||
gdb_assert (signo == TARGET_SIGNAL_0);
|
||
signo = saved_signo;
|
||
lp->status = 0;
|
||
}
|
||
}
|
||
|
||
if (lp->status)
|
||
{
|
||
/* FIXME: What should we do if we are supposed to continue
|
||
this thread with a signal? */
|
||
gdb_assert (signo == TARGET_SIGNAL_0);
|
||
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLR: Short circuiting for status 0x%x\n",
|
||
lp->status);
|
||
|
||
return;
|
||
}
|
||
|
||
/* Mark LWP as not stopped to prevent it from being continued by
|
||
resume_callback. */
|
||
lp->stopped = 0;
|
||
|
||
if (resume_all)
|
||
iterate_over_lwps (resume_callback, NULL);
|
||
|
||
linux_ops->to_resume (ptid, step, signo);
|
||
memset (&lp->siginfo, 0, sizeof (lp->siginfo));
|
||
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLR: %s %s, %s (resume event thread)\n",
|
||
step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
|
||
target_pid_to_str (ptid),
|
||
signo ? strsignal (signo) : "0");
|
||
|
||
if (target_can_async_p ())
|
||
target_async (inferior_event_handler, 0);
|
||
}
|
||
|
||
/* Issue kill to specified lwp. */
|
||
|
||
static int tkill_failed;
|
||
|
||
static int
|
||
kill_lwp (int lwpid, int signo)
|
||
{
|
||
errno = 0;
|
||
|
||
/* 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 HAVE_TKILL_SYSCALL
|
||
if (!tkill_failed)
|
||
{
|
||
int ret = syscall (__NR_tkill, lwpid, signo);
|
||
if (errno != ENOSYS)
|
||
return ret;
|
||
errno = 0;
|
||
tkill_failed = 1;
|
||
}
|
||
#endif
|
||
|
||
return kill (lwpid, signo);
|
||
}
|
||
|
||
/* Handle a GNU/Linux extended wait response. If we see a clone
|
||
event, we need to add the new LWP to our list (and not report the
|
||
trap to higher layers). This function returns non-zero if the
|
||
event should be ignored and we should wait again. If STOPPING is
|
||
true, the new LWP remains stopped, otherwise it is continued. */
|
||
|
||
static int
|
||
linux_handle_extended_wait (struct lwp_info *lp, int status,
|
||
int stopping)
|
||
{
|
||
int pid = GET_LWP (lp->ptid);
|
||
struct target_waitstatus *ourstatus = &lp->waitstatus;
|
||
struct lwp_info *new_lp = NULL;
|
||
int event = status >> 16;
|
||
|
||
if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK
|
||
|| event == PTRACE_EVENT_CLONE)
|
||
{
|
||
unsigned long new_pid;
|
||
int ret;
|
||
|
||
ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid);
|
||
|
||
/* If we haven't already seen the new PID stop, wait for it now. */
|
||
if (! pull_pid_from_list (&stopped_pids, new_pid, &status))
|
||
{
|
||
/* The new child has a pending SIGSTOP. We can't affect it until it
|
||
hits the SIGSTOP, but we're already attached. */
|
||
ret = my_waitpid (new_pid, &status,
|
||
(event == PTRACE_EVENT_CLONE) ? __WCLONE : 0);
|
||
if (ret == -1)
|
||
perror_with_name (_("waiting for new child"));
|
||
else if (ret != new_pid)
|
||
internal_error (__FILE__, __LINE__,
|
||
_("wait returned unexpected PID %d"), ret);
|
||
else if (!WIFSTOPPED (status))
|
||
internal_error (__FILE__, __LINE__,
|
||
_("wait returned unexpected status 0x%x"), status);
|
||
}
|
||
|
||
ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0);
|
||
|
||
if (event == PTRACE_EVENT_FORK)
|
||
ourstatus->kind = TARGET_WAITKIND_FORKED;
|
||
else if (event == PTRACE_EVENT_VFORK)
|
||
ourstatus->kind = TARGET_WAITKIND_VFORKED;
|
||
else
|
||
{
|
||
struct cleanup *old_chain;
|
||
|
||
ourstatus->kind = TARGET_WAITKIND_IGNORE;
|
||
new_lp = add_lwp (BUILD_LWP (new_pid, GET_PID (inferior_ptid)));
|
||
new_lp->cloned = 1;
|
||
new_lp->stopped = 1;
|
||
|
||
if (WSTOPSIG (status) != SIGSTOP)
|
||
{
|
||
/* This can happen if someone starts sending signals to
|
||
the new thread before it gets a chance to run, which
|
||
have a lower number than SIGSTOP (e.g. SIGUSR1).
|
||
This is an unlikely case, and harder to handle for
|
||
fork / vfork than for clone, so we do not try - but
|
||
we handle it for clone events here. We'll send
|
||
the other signal on to the thread below. */
|
||
|
||
new_lp->signalled = 1;
|
||
}
|
||
else
|
||
status = 0;
|
||
|
||
if (non_stop)
|
||
{
|
||
/* Add the new thread to GDB's lists as soon as possible
|
||
so that:
|
||
|
||
1) the frontend doesn't have to wait for a stop to
|
||
display them, and,
|
||
|
||
2) we tag it with the correct running state. */
|
||
|
||
/* If the thread_db layer is active, let it know about
|
||
this new thread, and add it to GDB's list. */
|
||
if (!thread_db_attach_lwp (new_lp->ptid))
|
||
{
|
||
/* We're not using thread_db. Add it to GDB's
|
||
list. */
|
||
target_post_attach (GET_LWP (new_lp->ptid));
|
||
add_thread (new_lp->ptid);
|
||
}
|
||
|
||
if (!stopping)
|
||
{
|
||
set_running (new_lp->ptid, 1);
|
||
set_executing (new_lp->ptid, 1);
|
||
}
|
||
}
|
||
|
||
if (!stopping)
|
||
{
|
||
new_lp->stopped = 0;
|
||
new_lp->resumed = 1;
|
||
ptrace (PTRACE_CONT, new_pid, 0,
|
||
status ? WSTOPSIG (status) : 0);
|
||
}
|
||
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LHEW: Got clone event from LWP %ld, resuming\n",
|
||
GET_LWP (lp->ptid));
|
||
ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
|
||
|
||
return 1;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
if (event == PTRACE_EVENT_EXEC)
|
||
{
|
||
ourstatus->kind = TARGET_WAITKIND_EXECD;
|
||
ourstatus->value.execd_pathname
|
||
= xstrdup (linux_child_pid_to_exec_file (pid));
|
||
|
||
if (linux_parent_pid)
|
||
{
|
||
detach_breakpoints (linux_parent_pid);
|
||
ptrace (PTRACE_DETACH, linux_parent_pid, 0, 0);
|
||
|
||
linux_parent_pid = 0;
|
||
}
|
||
|
||
/* At this point, all inserted breakpoints are gone. Doing this
|
||
as soon as we detect an exec prevents the badness of deleting
|
||
a breakpoint writing the current "shadow contents" to lift
|
||
the bp. That shadow is NOT valid after an exec.
|
||
|
||
Note that we have to do this after the detach_breakpoints
|
||
call above, otherwise breakpoints wouldn't be lifted from the
|
||
parent on a vfork, because detach_breakpoints would think
|
||
that breakpoints are not inserted. */
|
||
mark_breakpoints_out ();
|
||
return 0;
|
||
}
|
||
|
||
internal_error (__FILE__, __LINE__,
|
||
_("unknown ptrace event %d"), event);
|
||
}
|
||
|
||
/* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
|
||
exited. */
|
||
|
||
static int
|
||
wait_lwp (struct lwp_info *lp)
|
||
{
|
||
pid_t pid;
|
||
int status;
|
||
int thread_dead = 0;
|
||
|
||
gdb_assert (!lp->stopped);
|
||
gdb_assert (lp->status == 0);
|
||
|
||
pid = my_waitpid (GET_LWP (lp->ptid), &status, 0);
|
||
if (pid == -1 && errno == ECHILD)
|
||
{
|
||
pid = my_waitpid (GET_LWP (lp->ptid), &status, __WCLONE);
|
||
if (pid == -1 && errno == ECHILD)
|
||
{
|
||
/* The thread has previously exited. We need to delete it
|
||
now because, for some vendor 2.4 kernels with NPTL
|
||
support backported, there won't be an exit event unless
|
||
it is the main thread. 2.6 kernels will report an exit
|
||
event for each thread that exits, as expected. */
|
||
thread_dead = 1;
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
|
||
target_pid_to_str (lp->ptid));
|
||
}
|
||
}
|
||
|
||
if (!thread_dead)
|
||
{
|
||
gdb_assert (pid == GET_LWP (lp->ptid));
|
||
|
||
if (debug_linux_nat)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"WL: waitpid %s received %s\n",
|
||
target_pid_to_str (lp->ptid),
|
||
status_to_str (status));
|
||
}
|
||
}
|
||
|
||
/* Check if the thread has exited. */
|
||
if (WIFEXITED (status) || WIFSIGNALED (status))
|
||
{
|
||
thread_dead = 1;
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n",
|
||
target_pid_to_str (lp->ptid));
|
||
}
|
||
|
||
if (thread_dead)
|
||
{
|
||
exit_lwp (lp);
|
||
return 0;
|
||
}
|
||
|
||
gdb_assert (WIFSTOPPED (status));
|
||
|
||
/* Handle GNU/Linux's extended waitstatus for trace events. */
|
||
if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
|
||
{
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"WL: Handling extended status 0x%06x\n",
|
||
status);
|
||
if (linux_handle_extended_wait (lp, status, 1))
|
||
return wait_lwp (lp);
|
||
}
|
||
|
||
return status;
|
||
}
|
||
|
||
/* Save the most recent siginfo for LP. This is currently only called
|
||
for SIGTRAP; some ports use the si_addr field for
|
||
target_stopped_data_address. In the future, it may also be used to
|
||
restore the siginfo of requeued signals. */
|
||
|
||
static void
|
||
save_siginfo (struct lwp_info *lp)
|
||
{
|
||
errno = 0;
|
||
ptrace (PTRACE_GETSIGINFO, GET_LWP (lp->ptid),
|
||
(PTRACE_TYPE_ARG3) 0, &lp->siginfo);
|
||
|
||
if (errno != 0)
|
||
memset (&lp->siginfo, 0, sizeof (lp->siginfo));
|
||
}
|
||
|
||
/* Send a SIGSTOP to LP. */
|
||
|
||
static int
|
||
stop_callback (struct lwp_info *lp, void *data)
|
||
{
|
||
if (!lp->stopped && !lp->signalled)
|
||
{
|
||
int ret;
|
||
|
||
if (debug_linux_nat)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"SC: kill %s **<SIGSTOP>**\n",
|
||
target_pid_to_str (lp->ptid));
|
||
}
|
||
errno = 0;
|
||
ret = kill_lwp (GET_LWP (lp->ptid), SIGSTOP);
|
||
if (debug_linux_nat)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"SC: lwp kill %d %s\n",
|
||
ret,
|
||
errno ? safe_strerror (errno) : "ERRNO-OK");
|
||
}
|
||
|
||
lp->signalled = 1;
|
||
gdb_assert (lp->status == 0);
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Return non-zero if LWP PID has a pending SIGINT. */
|
||
|
||
static int
|
||
linux_nat_has_pending_sigint (int pid)
|
||
{
|
||
sigset_t pending, blocked, ignored;
|
||
int i;
|
||
|
||
linux_proc_pending_signals (pid, &pending, &blocked, &ignored);
|
||
|
||
if (sigismember (&pending, SIGINT)
|
||
&& !sigismember (&ignored, SIGINT))
|
||
return 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Set a flag in LP indicating that we should ignore its next SIGINT. */
|
||
|
||
static int
|
||
set_ignore_sigint (struct lwp_info *lp, void *data)
|
||
{
|
||
/* If a thread has a pending SIGINT, consume it; otherwise, set a
|
||
flag to consume the next one. */
|
||
if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status)
|
||
&& WSTOPSIG (lp->status) == SIGINT)
|
||
lp->status = 0;
|
||
else
|
||
lp->ignore_sigint = 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
|
||
This function is called after we know the LWP has stopped; if the LWP
|
||
stopped before the expected SIGINT was delivered, then it will never have
|
||
arrived. Also, if the signal was delivered to a shared queue and consumed
|
||
by a different thread, it will never be delivered to this LWP. */
|
||
|
||
static void
|
||
maybe_clear_ignore_sigint (struct lwp_info *lp)
|
||
{
|
||
if (!lp->ignore_sigint)
|
||
return;
|
||
|
||
if (!linux_nat_has_pending_sigint (GET_LWP (lp->ptid)))
|
||
{
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"MCIS: Clearing bogus flag for %s\n",
|
||
target_pid_to_str (lp->ptid));
|
||
lp->ignore_sigint = 0;
|
||
}
|
||
}
|
||
|
||
/* Wait until LP is stopped. */
|
||
|
||
static int
|
||
stop_wait_callback (struct lwp_info *lp, void *data)
|
||
{
|
||
if (!lp->stopped)
|
||
{
|
||
int status;
|
||
|
||
status = wait_lwp (lp);
|
||
if (status == 0)
|
||
return 0;
|
||
|
||
if (lp->ignore_sigint && WIFSTOPPED (status)
|
||
&& WSTOPSIG (status) == SIGINT)
|
||
{
|
||
lp->ignore_sigint = 0;
|
||
|
||
errno = 0;
|
||
ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"PTRACE_CONT %s, 0, 0 (%s) (discarding SIGINT)\n",
|
||
target_pid_to_str (lp->ptid),
|
||
errno ? safe_strerror (errno) : "OK");
|
||
|
||
return stop_wait_callback (lp, NULL);
|
||
}
|
||
|
||
maybe_clear_ignore_sigint (lp);
|
||
|
||
if (WSTOPSIG (status) != SIGSTOP)
|
||
{
|
||
if (WSTOPSIG (status) == SIGTRAP)
|
||
{
|
||
/* 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
|
||
thread will have already tripped on it. */
|
||
|
||
/* Save the trap's siginfo in case we need it later. */
|
||
save_siginfo (lp);
|
||
|
||
/* Now resume this LWP and get the SIGSTOP event. */
|
||
errno = 0;
|
||
ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
|
||
if (debug_linux_nat)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"PTRACE_CONT %s, 0, 0 (%s)\n",
|
||
target_pid_to_str (lp->ptid),
|
||
errno ? safe_strerror (errno) : "OK");
|
||
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"SWC: Candidate SIGTRAP event in %s\n",
|
||
target_pid_to_str (lp->ptid));
|
||
}
|
||
/* Hold this event/waitstatus while we check to see if
|
||
there are any more (we still want to get that SIGSTOP). */
|
||
stop_wait_callback (lp, NULL);
|
||
|
||
if (target_can_async_p ())
|
||
{
|
||
/* Don't leave a pending wait status in async mode.
|
||
Retrigger the breakpoint. */
|
||
if (!cancel_breakpoint (lp))
|
||
{
|
||
/* There was no gdb breakpoint set at pc. Put
|
||
the event back in the queue. */
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"SWC: kill %s, %s\n",
|
||
target_pid_to_str (lp->ptid),
|
||
status_to_str ((int) status));
|
||
kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (status));
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* Hold the SIGTRAP for handling by
|
||
linux_nat_wait. */
|
||
/* If there's another event, throw it back into the
|
||
queue. */
|
||
if (lp->status)
|
||
{
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"SWC: kill %s, %s\n",
|
||
target_pid_to_str (lp->ptid),
|
||
status_to_str ((int) status));
|
||
kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (lp->status));
|
||
}
|
||
/* Save the sigtrap event. */
|
||
lp->status = status;
|
||
}
|
||
return 0;
|
||
}
|
||
else
|
||
{
|
||
/* The thread was stopped with a signal other than
|
||
SIGSTOP, and didn't accidentally trip a breakpoint. */
|
||
|
||
if (debug_linux_nat)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"SWC: Pending event %s in %s\n",
|
||
status_to_str ((int) status),
|
||
target_pid_to_str (lp->ptid));
|
||
}
|
||
/* Now resume this LWP and get the SIGSTOP event. */
|
||
errno = 0;
|
||
ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"SWC: PTRACE_CONT %s, 0, 0 (%s)\n",
|
||
target_pid_to_str (lp->ptid),
|
||
errno ? safe_strerror (errno) : "OK");
|
||
|
||
/* Hold this event/waitstatus while we check to see if
|
||
there are any more (we still want to get that SIGSTOP). */
|
||
stop_wait_callback (lp, NULL);
|
||
|
||
/* If the lp->status field is still empty, use it to
|
||
hold this event. If not, then this event must be
|
||
returned to the event queue of the LWP. */
|
||
if (lp->status || target_can_async_p ())
|
||
{
|
||
if (debug_linux_nat)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"SWC: kill %s, %s\n",
|
||
target_pid_to_str (lp->ptid),
|
||
status_to_str ((int) status));
|
||
}
|
||
kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (status));
|
||
}
|
||
else
|
||
lp->status = status;
|
||
return 0;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* We caught the SIGSTOP that we intended to catch, so
|
||
there's no SIGSTOP pending. */
|
||
lp->stopped = 1;
|
||
lp->signalled = 0;
|
||
}
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Return non-zero if LP has a wait status pending. */
|
||
|
||
static int
|
||
status_callback (struct lwp_info *lp, void *data)
|
||
{
|
||
/* Only report a pending wait status if we pretend that this has
|
||
indeed been resumed. */
|
||
return (lp->status != 0 && lp->resumed);
|
||
}
|
||
|
||
/* Return non-zero if LP isn't stopped. */
|
||
|
||
static int
|
||
running_callback (struct lwp_info *lp, void *data)
|
||
{
|
||
return (lp->stopped == 0 || (lp->status != 0 && lp->resumed));
|
||
}
|
||
|
||
/* Count the LWP's that have had events. */
|
||
|
||
static int
|
||
count_events_callback (struct lwp_info *lp, void *data)
|
||
{
|
||
int *count = data;
|
||
|
||
gdb_assert (count != NULL);
|
||
|
||
/* Count only resumed LWPs that have a SIGTRAP event pending. */
|
||
if (lp->status != 0 && lp->resumed
|
||
&& WIFSTOPPED (lp->status) && WSTOPSIG (lp->status) == SIGTRAP)
|
||
(*count)++;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Select the LWP (if any) that is currently being single-stepped. */
|
||
|
||
static int
|
||
select_singlestep_lwp_callback (struct lwp_info *lp, void *data)
|
||
{
|
||
if (lp->step && lp->status != 0)
|
||
return 1;
|
||
else
|
||
return 0;
|
||
}
|
||
|
||
/* Select the Nth LWP that has had a SIGTRAP event. */
|
||
|
||
static int
|
||
select_event_lwp_callback (struct lwp_info *lp, void *data)
|
||
{
|
||
int *selector = data;
|
||
|
||
gdb_assert (selector != NULL);
|
||
|
||
/* Select only resumed LWPs that have a SIGTRAP event pending. */
|
||
if (lp->status != 0 && lp->resumed
|
||
&& WIFSTOPPED (lp->status) && WSTOPSIG (lp->status) == SIGTRAP)
|
||
if ((*selector)-- == 0)
|
||
return 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
static int
|
||
cancel_breakpoint (struct lwp_info *lp)
|
||
{
|
||
/* 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.
|
||
|
||
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. */
|
||
|
||
struct regcache *regcache = get_thread_regcache (lp->ptid);
|
||
struct gdbarch *gdbarch = get_regcache_arch (regcache);
|
||
CORE_ADDR pc;
|
||
|
||
pc = regcache_read_pc (regcache) - gdbarch_decr_pc_after_break (gdbarch);
|
||
if (breakpoint_inserted_here_p (pc))
|
||
{
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"CB: Push back breakpoint for %s\n",
|
||
target_pid_to_str (lp->ptid));
|
||
|
||
/* Back up the PC if necessary. */
|
||
if (gdbarch_decr_pc_after_break (gdbarch))
|
||
regcache_write_pc (regcache, pc);
|
||
|
||
return 1;
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
static int
|
||
cancel_breakpoints_callback (struct lwp_info *lp, void *data)
|
||
{
|
||
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 (lp->status != 0
|
||
&& WIFSTOPPED (lp->status) && WSTOPSIG (lp->status) == SIGTRAP
|
||
&& cancel_breakpoint (lp))
|
||
/* Throw away the SIGTRAP. */
|
||
lp->status = 0;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Select one LWP out of those that have events pending. */
|
||
|
||
static void
|
||
select_event_lwp (struct lwp_info **orig_lp, int *status)
|
||
{
|
||
int num_events = 0;
|
||
int random_selector;
|
||
struct lwp_info *event_lp;
|
||
|
||
/* Record the wait status for the original LWP. */
|
||
(*orig_lp)->status = *status;
|
||
|
||
/* Give preference to any LWP that is being single-stepped. */
|
||
event_lp = iterate_over_lwps (select_singlestep_lwp_callback, NULL);
|
||
if (event_lp != NULL)
|
||
{
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"SEL: Select single-step %s\n",
|
||
target_pid_to_str (event_lp->ptid));
|
||
}
|
||
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. */
|
||
iterate_over_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_linux_nat && num_events > 1)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"SEL: Found %d SIGTRAP events, selecting #%d\n",
|
||
num_events, random_selector);
|
||
|
||
event_lp = iterate_over_lwps (select_event_lwp_callback,
|
||
&random_selector);
|
||
}
|
||
|
||
if (event_lp != NULL)
|
||
{
|
||
/* Switch the event LWP. */
|
||
*orig_lp = event_lp;
|
||
*status = event_lp->status;
|
||
}
|
||
|
||
/* Flush the wait status for the event LWP. */
|
||
(*orig_lp)->status = 0;
|
||
}
|
||
|
||
/* Return non-zero if LP has been resumed. */
|
||
|
||
static int
|
||
resumed_callback (struct lwp_info *lp, void *data)
|
||
{
|
||
return lp->resumed;
|
||
}
|
||
|
||
/* Stop an active thread, verify it still exists, then resume it. */
|
||
|
||
static int
|
||
stop_and_resume_callback (struct lwp_info *lp, void *data)
|
||
{
|
||
struct lwp_info *ptr;
|
||
|
||
if (!lp->stopped && !lp->signalled)
|
||
{
|
||
stop_callback (lp, NULL);
|
||
stop_wait_callback (lp, NULL);
|
||
/* Resume if the lwp still exists. */
|
||
for (ptr = lwp_list; ptr; ptr = ptr->next)
|
||
if (lp == ptr)
|
||
{
|
||
resume_callback (lp, NULL);
|
||
resume_set_callback (lp, NULL);
|
||
}
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
/* Check if we should go on and pass this event to common code.
|
||
Return the affected lwp if we are, or NULL otherwise. */
|
||
static struct lwp_info *
|
||
linux_nat_filter_event (int lwpid, int status, int options)
|
||
{
|
||
struct lwp_info *lp;
|
||
|
||
lp = find_lwp_pid (pid_to_ptid (lwpid));
|
||
|
||
/* Check for stop events reported by a process we didn't already
|
||
know about - anything not already in our LWP list.
|
||
|
||
If we're expecting to receive stopped processes after
|
||
fork, vfork, and clone events, then we'll just add the
|
||
new one to our list and go back to waiting for the event
|
||
to be reported - the stopped process might be returned
|
||
from waitpid before or after the event is. */
|
||
if (WIFSTOPPED (status) && !lp)
|
||
{
|
||
linux_record_stopped_pid (lwpid, status);
|
||
return NULL;
|
||
}
|
||
|
||
/* Make sure we don't report an event for the exit of an LWP not in
|
||
our list, i.e. not part of the current process. This can happen
|
||
if we detach from a program we original forked and then it
|
||
exits. */
|
||
if (!WIFSTOPPED (status) && !lp)
|
||
return NULL;
|
||
|
||
/* NOTE drow/2003-06-17: This code seems to be meant for debugging
|
||
CLONE_PTRACE processes which do not use the thread library -
|
||
otherwise we wouldn't find the new LWP this way. That doesn't
|
||
currently work, and the following code is currently unreachable
|
||
due to the two blocks above. If it's fixed some day, this code
|
||
should be broken out into a function so that we can also pick up
|
||
LWPs from the new interface. */
|
||
if (!lp)
|
||
{
|
||
lp = add_lwp (BUILD_LWP (lwpid, GET_PID (inferior_ptid)));
|
||
if (options & __WCLONE)
|
||
lp->cloned = 1;
|
||
|
||
gdb_assert (WIFSTOPPED (status)
|
||
&& WSTOPSIG (status) == SIGSTOP);
|
||
lp->signalled = 1;
|
||
|
||
if (!in_thread_list (inferior_ptid))
|
||
{
|
||
inferior_ptid = BUILD_LWP (GET_PID (inferior_ptid),
|
||
GET_PID (inferior_ptid));
|
||
add_thread (inferior_ptid);
|
||
}
|
||
|
||
add_thread (lp->ptid);
|
||
}
|
||
|
||
/* Save the trap's siginfo in case we need it later. */
|
||
if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP)
|
||
save_siginfo (lp);
|
||
|
||
/* Handle GNU/Linux's extended waitstatus for trace events. */
|
||
if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
|
||
{
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLW: Handling extended status 0x%06x\n",
|
||
status);
|
||
if (linux_handle_extended_wait (lp, status, 0))
|
||
return NULL;
|
||
}
|
||
|
||
/* Check if the thread has exited. */
|
||
if ((WIFEXITED (status) || WIFSIGNALED (status)) && num_lwps > 1)
|
||
{
|
||
/* If this is the main thread, we must stop all threads and
|
||
verify if they are still alive. This is because in the nptl
|
||
thread model, there is no signal issued for exiting LWPs
|
||
other than the main thread. We only get the main thread exit
|
||
signal once all child threads have already exited. If we
|
||
stop all the threads and use the stop_wait_callback to check
|
||
if they have exited we can determine whether this signal
|
||
should be ignored or whether it means the end of the debugged
|
||
application, regardless of which threading model is being
|
||
used. */
|
||
if (GET_PID (lp->ptid) == GET_LWP (lp->ptid))
|
||
{
|
||
lp->stopped = 1;
|
||
iterate_over_lwps (stop_and_resume_callback, NULL);
|
||
}
|
||
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLW: %s exited.\n",
|
||
target_pid_to_str (lp->ptid));
|
||
|
||
exit_lwp (lp);
|
||
|
||
/* If there is at least one more LWP, then the exit signal was
|
||
not the end of the debugged application and should be
|
||
ignored. */
|
||
if (num_lwps > 0)
|
||
return NULL;
|
||
}
|
||
|
||
/* Check if the current LWP has previously exited. In the nptl
|
||
thread model, LWPs other than the main thread do not issue
|
||
signals when they exit so we must check whenever the thread has
|
||
stopped. A similar check is made in stop_wait_callback(). */
|
||
if (num_lwps > 1 && !linux_nat_thread_alive (lp->ptid))
|
||
{
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLW: %s exited.\n",
|
||
target_pid_to_str (lp->ptid));
|
||
|
||
exit_lwp (lp);
|
||
|
||
/* Make sure there is at least one thread running. */
|
||
gdb_assert (iterate_over_lwps (running_callback, NULL));
|
||
|
||
/* Discard the event. */
|
||
return NULL;
|
||
}
|
||
|
||
/* Make sure we don't report a SIGSTOP that we sent ourselves in
|
||
an attempt to stop an LWP. */
|
||
if (lp->signalled
|
||
&& WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP)
|
||
{
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLW: Delayed SIGSTOP caught for %s.\n",
|
||
target_pid_to_str (lp->ptid));
|
||
|
||
/* This is a delayed SIGSTOP. */
|
||
lp->signalled = 0;
|
||
|
||
registers_changed ();
|
||
|
||
linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)),
|
||
lp->step, TARGET_SIGNAL_0);
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
|
||
lp->step ?
|
||
"PTRACE_SINGLESTEP" : "PTRACE_CONT",
|
||
target_pid_to_str (lp->ptid));
|
||
|
||
lp->stopped = 0;
|
||
gdb_assert (lp->resumed);
|
||
|
||
/* Discard the event. */
|
||
return NULL;
|
||
}
|
||
|
||
/* Make sure we don't report a SIGINT that we have already displayed
|
||
for another thread. */
|
||
if (lp->ignore_sigint
|
||
&& WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT)
|
||
{
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLW: Delayed SIGINT caught for %s.\n",
|
||
target_pid_to_str (lp->ptid));
|
||
|
||
/* This is a delayed SIGINT. */
|
||
lp->ignore_sigint = 0;
|
||
|
||
registers_changed ();
|
||
linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)),
|
||
lp->step, TARGET_SIGNAL_0);
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLW: %s %s, 0, 0 (discard SIGINT)\n",
|
||
lp->step ?
|
||
"PTRACE_SINGLESTEP" : "PTRACE_CONT",
|
||
target_pid_to_str (lp->ptid));
|
||
|
||
lp->stopped = 0;
|
||
gdb_assert (lp->resumed);
|
||
|
||
/* Discard the event. */
|
||
return NULL;
|
||
}
|
||
|
||
/* An interesting event. */
|
||
gdb_assert (lp);
|
||
return lp;
|
||
}
|
||
|
||
/* Get the events stored in the pipe into the local queue, so they are
|
||
accessible to queued_waitpid. We need to do this, since it is not
|
||
always the case that the event at the head of the pipe is the event
|
||
we want. */
|
||
|
||
static void
|
||
pipe_to_local_event_queue (void)
|
||
{
|
||
if (debug_linux_nat_async)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"PTLEQ: linux_nat_num_queued_events(%d)\n",
|
||
linux_nat_num_queued_events);
|
||
while (linux_nat_num_queued_events)
|
||
{
|
||
int lwpid, status, options;
|
||
lwpid = linux_nat_event_pipe_pop (&status, &options);
|
||
gdb_assert (lwpid > 0);
|
||
push_waitpid (lwpid, status, options);
|
||
}
|
||
}
|
||
|
||
/* Get the unprocessed events stored in the local queue back into the
|
||
pipe, so the event loop realizes there's something else to
|
||
process. */
|
||
|
||
static void
|
||
local_event_queue_to_pipe (void)
|
||
{
|
||
struct waitpid_result *w = waitpid_queue;
|
||
while (w)
|
||
{
|
||
struct waitpid_result *next = w->next;
|
||
linux_nat_event_pipe_push (w->pid,
|
||
w->status,
|
||
w->options);
|
||
xfree (w);
|
||
w = next;
|
||
}
|
||
waitpid_queue = NULL;
|
||
|
||
if (debug_linux_nat_async)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LEQTP: linux_nat_num_queued_events(%d)\n",
|
||
linux_nat_num_queued_events);
|
||
}
|
||
|
||
static ptid_t
|
||
linux_nat_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
|
||
{
|
||
struct lwp_info *lp = NULL;
|
||
int options = 0;
|
||
int status = 0;
|
||
pid_t pid = PIDGET (ptid);
|
||
|
||
if (debug_linux_nat_async)
|
||
fprintf_unfiltered (gdb_stdlog, "LLW: enter\n");
|
||
|
||
/* The first time we get here after starting a new inferior, we may
|
||
not have added it to the LWP list yet - this is the earliest
|
||
moment at which we know its PID. */
|
||
if (num_lwps == 0)
|
||
{
|
||
gdb_assert (!is_lwp (inferior_ptid));
|
||
|
||
/* Upgrade the main thread's ptid. */
|
||
thread_change_ptid (inferior_ptid,
|
||
BUILD_LWP (GET_PID (inferior_ptid),
|
||
GET_PID (inferior_ptid)));
|
||
|
||
lp = add_lwp (inferior_ptid);
|
||
lp->resumed = 1;
|
||
}
|
||
|
||
/* Block events while we're here. */
|
||
linux_nat_async_events (sigchld_sync);
|
||
|
||
retry:
|
||
|
||
/* Make sure there is at least one LWP that has been resumed. */
|
||
gdb_assert (iterate_over_lwps (resumed_callback, NULL));
|
||
|
||
/* First check if there is a LWP with a wait status pending. */
|
||
if (pid == -1)
|
||
{
|
||
/* Any LWP that's been resumed will do. */
|
||
lp = iterate_over_lwps (status_callback, NULL);
|
||
if (lp)
|
||
{
|
||
if (target_can_async_p ())
|
||
internal_error (__FILE__, __LINE__,
|
||
"Found an LWP with a pending status in async mode.");
|
||
|
||
status = lp->status;
|
||
lp->status = 0;
|
||
|
||
if (debug_linux_nat && status)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLW: Using pending wait status %s for %s.\n",
|
||
status_to_str (status),
|
||
target_pid_to_str (lp->ptid));
|
||
}
|
||
|
||
/* But if we don't find one, we'll have to wait, and check both
|
||
cloned and uncloned processes. We start with the cloned
|
||
processes. */
|
||
options = __WCLONE | WNOHANG;
|
||
}
|
||
else if (is_lwp (ptid))
|
||
{
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLW: Waiting for specific LWP %s.\n",
|
||
target_pid_to_str (ptid));
|
||
|
||
/* We have a specific LWP to check. */
|
||
lp = find_lwp_pid (ptid);
|
||
gdb_assert (lp);
|
||
status = lp->status;
|
||
lp->status = 0;
|
||
|
||
if (debug_linux_nat && status)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLW: Using pending wait status %s for %s.\n",
|
||
status_to_str (status),
|
||
target_pid_to_str (lp->ptid));
|
||
|
||
/* If we have to wait, take into account whether PID is a cloned
|
||
process or not. And we have to convert it to something that
|
||
the layer beneath us can understand. */
|
||
options = lp->cloned ? __WCLONE : 0;
|
||
pid = GET_LWP (ptid);
|
||
}
|
||
|
||
if (status && lp->signalled)
|
||
{
|
||
/* A pending SIGSTOP may interfere with the normal stream of
|
||
events. In a typical case where interference is a problem,
|
||
we have a SIGSTOP signal pending for LWP A while
|
||
single-stepping it, encounter an event in LWP B, and take the
|
||
pending SIGSTOP while trying to stop LWP A. After processing
|
||
the event in LWP B, LWP A is continued, and we'll never see
|
||
the SIGTRAP associated with the last time we were
|
||
single-stepping LWP A. */
|
||
|
||
/* Resume the thread. It should halt immediately returning the
|
||
pending SIGSTOP. */
|
||
registers_changed ();
|
||
linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)),
|
||
lp->step, TARGET_SIGNAL_0);
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLW: %s %s, 0, 0 (expect SIGSTOP)\n",
|
||
lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
|
||
target_pid_to_str (lp->ptid));
|
||
lp->stopped = 0;
|
||
gdb_assert (lp->resumed);
|
||
|
||
/* This should catch the pending SIGSTOP. */
|
||
stop_wait_callback (lp, NULL);
|
||
}
|
||
|
||
if (!target_can_async_p ())
|
||
{
|
||
/* Causes SIGINT to be passed on to the attached process. */
|
||
set_sigint_trap ();
|
||
set_sigio_trap ();
|
||
}
|
||
|
||
while (status == 0)
|
||
{
|
||
pid_t lwpid;
|
||
|
||
if (target_can_async_p ())
|
||
/* In async mode, don't ever block. Only look at the locally
|
||
queued events. */
|
||
lwpid = queued_waitpid (pid, &status, options);
|
||
else
|
||
lwpid = my_waitpid (pid, &status, options);
|
||
|
||
if (lwpid > 0)
|
||
{
|
||
gdb_assert (pid == -1 || lwpid == pid);
|
||
|
||
if (debug_linux_nat)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLW: waitpid %ld received %s\n",
|
||
(long) lwpid, status_to_str (status));
|
||
}
|
||
|
||
lp = linux_nat_filter_event (lwpid, status, options);
|
||
if (!lp)
|
||
{
|
||
/* A discarded event. */
|
||
status = 0;
|
||
continue;
|
||
}
|
||
|
||
break;
|
||
}
|
||
|
||
if (pid == -1)
|
||
{
|
||
/* Alternate between checking cloned and uncloned processes. */
|
||
options ^= __WCLONE;
|
||
|
||
/* And every time we have checked both:
|
||
In async mode, return to event loop;
|
||
In sync mode, suspend waiting for a SIGCHLD signal. */
|
||
if (options & __WCLONE)
|
||
{
|
||
if (target_can_async_p ())
|
||
{
|
||
/* No interesting event. */
|
||
ourstatus->kind = TARGET_WAITKIND_IGNORE;
|
||
|
||
/* Get ready for the next event. */
|
||
target_async (inferior_event_handler, 0);
|
||
|
||
if (debug_linux_nat_async)
|
||
fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
|
||
|
||
return minus_one_ptid;
|
||
}
|
||
|
||
sigsuspend (&suspend_mask);
|
||
}
|
||
}
|
||
|
||
/* We shouldn't end up here unless we want to try again. */
|
||
gdb_assert (status == 0);
|
||
}
|
||
|
||
if (!target_can_async_p ())
|
||
{
|
||
clear_sigio_trap ();
|
||
clear_sigint_trap ();
|
||
}
|
||
|
||
gdb_assert (lp);
|
||
|
||
/* Don't report signals that GDB isn't interested in, such as
|
||
signals that are neither printed nor stopped upon. Stopping all
|
||
threads can be a bit time-consuming so if we want decent
|
||
performance with heavily multi-threaded programs, especially when
|
||
they're using a high frequency timer, we'd better avoid it if we
|
||
can. */
|
||
|
||
if (WIFSTOPPED (status))
|
||
{
|
||
int signo = target_signal_from_host (WSTOPSIG (status));
|
||
|
||
/* If we get a signal while single-stepping, we may need special
|
||
care, e.g. to skip the signal handler. Defer to common code. */
|
||
if (!lp->step
|
||
&& signal_stop_state (signo) == 0
|
||
&& signal_print_state (signo) == 0
|
||
&& signal_pass_state (signo) == 1)
|
||
{
|
||
/* FIMXE: kettenis/2001-06-06: Should we resume all threads
|
||
here? It is not clear we should. GDB may not expect
|
||
other threads to run. On the other hand, not resuming
|
||
newly attached threads may cause an unwanted delay in
|
||
getting them running. */
|
||
registers_changed ();
|
||
linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)),
|
||
lp->step, signo);
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLW: %s %s, %s (preempt 'handle')\n",
|
||
lp->step ?
|
||
"PTRACE_SINGLESTEP" : "PTRACE_CONT",
|
||
target_pid_to_str (lp->ptid),
|
||
signo ? strsignal (signo) : "0");
|
||
lp->stopped = 0;
|
||
status = 0;
|
||
goto retry;
|
||
}
|
||
|
||
if (signo == TARGET_SIGNAL_INT && signal_pass_state (signo) == 0)
|
||
{
|
||
/* If ^C/BREAK is typed at the tty/console, SIGINT gets
|
||
forwarded to the entire process group, that is, all LWPs
|
||
will receive it - unless they're using CLONE_THREAD to
|
||
share signals. Since we only want to report it once, we
|
||
mark it as ignored for all LWPs except this one. */
|
||
iterate_over_lwps (set_ignore_sigint, NULL);
|
||
lp->ignore_sigint = 0;
|
||
}
|
||
else
|
||
maybe_clear_ignore_sigint (lp);
|
||
}
|
||
|
||
/* This LWP is stopped now. */
|
||
lp->stopped = 1;
|
||
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog, "LLW: Candidate event %s in %s.\n",
|
||
status_to_str (status), target_pid_to_str (lp->ptid));
|
||
|
||
if (!non_stop)
|
||
{
|
||
/* Now stop all other LWP's ... */
|
||
iterate_over_lwps (stop_callback, NULL);
|
||
|
||
/* ... and wait until all of them have reported back that
|
||
they're no longer running. */
|
||
iterate_over_lwps (stop_wait_callback, 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 (pid == -1)
|
||
select_event_lwp (&lp, &status);
|
||
}
|
||
|
||
/* 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. */
|
||
iterate_over_lwps (cancel_breakpoints_callback, lp);
|
||
|
||
if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP)
|
||
{
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLW: trap ptid is %s.\n",
|
||
target_pid_to_str (lp->ptid));
|
||
}
|
||
|
||
if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
|
||
{
|
||
*ourstatus = lp->waitstatus;
|
||
lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
|
||
}
|
||
else
|
||
store_waitstatus (ourstatus, status);
|
||
|
||
/* Get ready for the next event. */
|
||
if (target_can_async_p ())
|
||
target_async (inferior_event_handler, 0);
|
||
|
||
if (debug_linux_nat_async)
|
||
fprintf_unfiltered (gdb_stdlog, "LLW: exit\n");
|
||
|
||
return lp->ptid;
|
||
}
|
||
|
||
static int
|
||
kill_callback (struct lwp_info *lp, void *data)
|
||
{
|
||
errno = 0;
|
||
ptrace (PTRACE_KILL, GET_LWP (lp->ptid), 0, 0);
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"KC: PTRACE_KILL %s, 0, 0 (%s)\n",
|
||
target_pid_to_str (lp->ptid),
|
||
errno ? safe_strerror (errno) : "OK");
|
||
|
||
return 0;
|
||
}
|
||
|
||
static int
|
||
kill_wait_callback (struct lwp_info *lp, void *data)
|
||
{
|
||
pid_t pid;
|
||
|
||
/* We must make sure that there are no pending events (delayed
|
||
SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
|
||
program doesn't interfere with any following debugging session. */
|
||
|
||
/* For cloned processes we must check both with __WCLONE and
|
||
without, since the exit status of a cloned process isn't reported
|
||
with __WCLONE. */
|
||
if (lp->cloned)
|
||
{
|
||
do
|
||
{
|
||
pid = my_waitpid (GET_LWP (lp->ptid), NULL, __WCLONE);
|
||
if (pid != (pid_t) -1)
|
||
{
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"KWC: wait %s received unknown.\n",
|
||
target_pid_to_str (lp->ptid));
|
||
/* The Linux kernel sometimes fails to kill a thread
|
||
completely after PTRACE_KILL; that goes from the stop
|
||
point in do_fork out to the one in
|
||
get_signal_to_deliever and waits again. So kill it
|
||
again. */
|
||
kill_callback (lp, NULL);
|
||
}
|
||
}
|
||
while (pid == GET_LWP (lp->ptid));
|
||
|
||
gdb_assert (pid == -1 && errno == ECHILD);
|
||
}
|
||
|
||
do
|
||
{
|
||
pid = my_waitpid (GET_LWP (lp->ptid), NULL, 0);
|
||
if (pid != (pid_t) -1)
|
||
{
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"KWC: wait %s received unk.\n",
|
||
target_pid_to_str (lp->ptid));
|
||
/* See the call to kill_callback above. */
|
||
kill_callback (lp, NULL);
|
||
}
|
||
}
|
||
while (pid == GET_LWP (lp->ptid));
|
||
|
||
gdb_assert (pid == -1 && errno == ECHILD);
|
||
return 0;
|
||
}
|
||
|
||
static void
|
||
linux_nat_kill (void)
|
||
{
|
||
struct target_waitstatus last;
|
||
ptid_t last_ptid;
|
||
int status;
|
||
|
||
if (target_can_async_p ())
|
||
target_async (NULL, 0);
|
||
|
||
/* If we're stopped while forking and we haven't followed yet,
|
||
kill the other task. We need to do this first because the
|
||
parent will be sleeping if this is a vfork. */
|
||
|
||
get_last_target_status (&last_ptid, &last);
|
||
|
||
if (last.kind == TARGET_WAITKIND_FORKED
|
||
|| last.kind == TARGET_WAITKIND_VFORKED)
|
||
{
|
||
ptrace (PT_KILL, PIDGET (last.value.related_pid), 0, 0);
|
||
wait (&status);
|
||
}
|
||
|
||
if (forks_exist_p ())
|
||
{
|
||
linux_fork_killall ();
|
||
drain_queued_events (-1);
|
||
}
|
||
else
|
||
{
|
||
/* Stop all threads before killing them, since ptrace requires
|
||
that the thread is stopped to sucessfully PTRACE_KILL. */
|
||
iterate_over_lwps (stop_callback, NULL);
|
||
/* ... and wait until all of them have reported back that
|
||
they're no longer running. */
|
||
iterate_over_lwps (stop_wait_callback, NULL);
|
||
|
||
/* Kill all LWP's ... */
|
||
iterate_over_lwps (kill_callback, NULL);
|
||
|
||
/* ... and wait until we've flushed all events. */
|
||
iterate_over_lwps (kill_wait_callback, NULL);
|
||
}
|
||
|
||
target_mourn_inferior ();
|
||
}
|
||
|
||
static void
|
||
linux_nat_mourn_inferior (void)
|
||
{
|
||
/* Destroy LWP info; it's no longer valid. */
|
||
init_lwp_list ();
|
||
|
||
if (! forks_exist_p ())
|
||
{
|
||
/* Normal case, no other forks available. */
|
||
if (target_can_async_p ())
|
||
linux_nat_async (NULL, 0);
|
||
linux_ops->to_mourn_inferior ();
|
||
}
|
||
else
|
||
/* Multi-fork case. The current inferior_ptid has exited, but
|
||
there are other viable forks to debug. Delete the exiting
|
||
one and context-switch to the first available. */
|
||
linux_fork_mourn_inferior ();
|
||
}
|
||
|
||
static LONGEST
|
||
linux_nat_xfer_partial (struct target_ops *ops, enum target_object object,
|
||
const char *annex, gdb_byte *readbuf,
|
||
const gdb_byte *writebuf,
|
||
ULONGEST offset, LONGEST len)
|
||
{
|
||
struct cleanup *old_chain = save_inferior_ptid ();
|
||
LONGEST xfer;
|
||
|
||
if (is_lwp (inferior_ptid))
|
||
inferior_ptid = pid_to_ptid (GET_LWP (inferior_ptid));
|
||
|
||
xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf,
|
||
offset, len);
|
||
|
||
do_cleanups (old_chain);
|
||
return xfer;
|
||
}
|
||
|
||
static int
|
||
linux_nat_thread_alive (ptid_t ptid)
|
||
{
|
||
int err;
|
||
|
||
gdb_assert (is_lwp (ptid));
|
||
|
||
/* Send signal 0 instead of anything ptrace, because ptracing a
|
||
running thread errors out claiming that the thread doesn't
|
||
exist. */
|
||
err = kill_lwp (GET_LWP (ptid), 0);
|
||
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLTA: KILL(SIG0) %s (%s)\n",
|
||
target_pid_to_str (ptid),
|
||
err ? safe_strerror (err) : "OK");
|
||
|
||
if (err != 0)
|
||
return 0;
|
||
|
||
return 1;
|
||
}
|
||
|
||
static char *
|
||
linux_nat_pid_to_str (ptid_t ptid)
|
||
{
|
||
static char buf[64];
|
||
|
||
if (is_lwp (ptid)
|
||
&& ((lwp_list && lwp_list->next)
|
||
|| GET_PID (ptid) != GET_LWP (ptid)))
|
||
{
|
||
snprintf (buf, sizeof (buf), "LWP %ld", GET_LWP (ptid));
|
||
return buf;
|
||
}
|
||
|
||
return normal_pid_to_str (ptid);
|
||
}
|
||
|
||
static void
|
||
sigchld_handler (int signo)
|
||
{
|
||
if (target_async_permitted
|
||
&& linux_nat_async_events_state != sigchld_sync
|
||
&& signo == SIGCHLD)
|
||
/* It is *always* a bug to hit this. */
|
||
internal_error (__FILE__, __LINE__,
|
||
"sigchld_handler called when async events are enabled");
|
||
|
||
/* Do nothing. The only reason for this handler is that it allows
|
||
us to use sigsuspend in linux_nat_wait above to wait for the
|
||
arrival of a SIGCHLD. */
|
||
}
|
||
|
||
/* Accepts an integer PID; Returns a string representing a file that
|
||
can be opened to get the symbols for the child process. */
|
||
|
||
static char *
|
||
linux_child_pid_to_exec_file (int pid)
|
||
{
|
||
char *name1, *name2;
|
||
|
||
name1 = xmalloc (MAXPATHLEN);
|
||
name2 = xmalloc (MAXPATHLEN);
|
||
make_cleanup (xfree, name1);
|
||
make_cleanup (xfree, name2);
|
||
memset (name2, 0, MAXPATHLEN);
|
||
|
||
sprintf (name1, "/proc/%d/exe", pid);
|
||
if (readlink (name1, name2, MAXPATHLEN) > 0)
|
||
return name2;
|
||
else
|
||
return name1;
|
||
}
|
||
|
||
/* Service function for corefiles and info proc. */
|
||
|
||
static int
|
||
read_mapping (FILE *mapfile,
|
||
long long *addr,
|
||
long long *endaddr,
|
||
char *permissions,
|
||
long long *offset,
|
||
char *device, long long *inode, char *filename)
|
||
{
|
||
int ret = fscanf (mapfile, "%llx-%llx %s %llx %s %llx",
|
||
addr, endaddr, permissions, offset, device, inode);
|
||
|
||
filename[0] = '\0';
|
||
if (ret > 0 && ret != EOF)
|
||
{
|
||
/* Eat everything up to EOL for the filename. This will prevent
|
||
weird filenames (such as one with embedded whitespace) from
|
||
confusing this code. It also makes this code more robust in
|
||
respect to annotations the kernel may add after the filename.
|
||
|
||
Note the filename is used for informational purposes
|
||
only. */
|
||
ret += fscanf (mapfile, "%[^\n]\n", filename);
|
||
}
|
||
|
||
return (ret != 0 && ret != EOF);
|
||
}
|
||
|
||
/* Fills the "to_find_memory_regions" target vector. Lists the memory
|
||
regions in the inferior for a corefile. */
|
||
|
||
static int
|
||
linux_nat_find_memory_regions (int (*func) (CORE_ADDR,
|
||
unsigned long,
|
||
int, int, int, void *), void *obfd)
|
||
{
|
||
long long pid = PIDGET (inferior_ptid);
|
||
char mapsfilename[MAXPATHLEN];
|
||
FILE *mapsfile;
|
||
long long addr, endaddr, size, offset, inode;
|
||
char permissions[8], device[8], filename[MAXPATHLEN];
|
||
int read, write, exec;
|
||
int ret;
|
||
|
||
/* Compose the filename for the /proc memory map, and open it. */
|
||
sprintf (mapsfilename, "/proc/%lld/maps", pid);
|
||
if ((mapsfile = fopen (mapsfilename, "r")) == NULL)
|
||
error (_("Could not open %s."), mapsfilename);
|
||
|
||
if (info_verbose)
|
||
fprintf_filtered (gdb_stdout,
|
||
"Reading memory regions from %s\n", mapsfilename);
|
||
|
||
/* Now iterate until end-of-file. */
|
||
while (read_mapping (mapsfile, &addr, &endaddr, &permissions[0],
|
||
&offset, &device[0], &inode, &filename[0]))
|
||
{
|
||
size = endaddr - addr;
|
||
|
||
/* Get the segment's permissions. */
|
||
read = (strchr (permissions, 'r') != 0);
|
||
write = (strchr (permissions, 'w') != 0);
|
||
exec = (strchr (permissions, 'x') != 0);
|
||
|
||
if (info_verbose)
|
||
{
|
||
fprintf_filtered (gdb_stdout,
|
||
"Save segment, %lld bytes at 0x%s (%c%c%c)",
|
||
size, paddr_nz (addr),
|
||
read ? 'r' : ' ',
|
||
write ? 'w' : ' ', exec ? 'x' : ' ');
|
||
if (filename[0])
|
||
fprintf_filtered (gdb_stdout, " for %s", filename);
|
||
fprintf_filtered (gdb_stdout, "\n");
|
||
}
|
||
|
||
/* Invoke the callback function to create the corefile
|
||
segment. */
|
||
func (addr, size, read, write, exec, obfd);
|
||
}
|
||
fclose (mapsfile);
|
||
return 0;
|
||
}
|
||
|
||
/* Records the thread's register state for the corefile note
|
||
section. */
|
||
|
||
static char *
|
||
linux_nat_do_thread_registers (bfd *obfd, ptid_t ptid,
|
||
char *note_data, int *note_size)
|
||
{
|
||
gdb_gregset_t gregs;
|
||
gdb_fpregset_t fpregs;
|
||
unsigned long lwp = ptid_get_lwp (ptid);
|
||
struct regcache *regcache = get_thread_regcache (ptid);
|
||
struct gdbarch *gdbarch = get_regcache_arch (regcache);
|
||
const struct regset *regset;
|
||
int core_regset_p;
|
||
struct cleanup *old_chain;
|
||
struct core_regset_section *sect_list;
|
||
char *gdb_regset;
|
||
|
||
old_chain = save_inferior_ptid ();
|
||
inferior_ptid = ptid;
|
||
target_fetch_registers (regcache, -1);
|
||
do_cleanups (old_chain);
|
||
|
||
core_regset_p = gdbarch_regset_from_core_section_p (gdbarch);
|
||
sect_list = gdbarch_core_regset_sections (gdbarch);
|
||
|
||
if (core_regset_p
|
||
&& (regset = gdbarch_regset_from_core_section (gdbarch, ".reg",
|
||
sizeof (gregs))) != NULL
|
||
&& regset->collect_regset != NULL)
|
||
regset->collect_regset (regset, regcache, -1,
|
||
&gregs, sizeof (gregs));
|
||
else
|
||
fill_gregset (regcache, &gregs, -1);
|
||
|
||
note_data = (char *) elfcore_write_prstatus (obfd,
|
||
note_data,
|
||
note_size,
|
||
lwp,
|
||
stop_signal, &gregs);
|
||
|
||
/* The loop below uses the new struct core_regset_section, which stores
|
||
the supported section names and sizes for the core file. Note that
|
||
note PRSTATUS needs to be treated specially. But the other notes are
|
||
structurally the same, so they can benefit from the new struct. */
|
||
if (core_regset_p && sect_list != NULL)
|
||
while (sect_list->sect_name != NULL)
|
||
{
|
||
/* .reg was already handled above. */
|
||
if (strcmp (sect_list->sect_name, ".reg") == 0)
|
||
{
|
||
sect_list++;
|
||
continue;
|
||
}
|
||
regset = gdbarch_regset_from_core_section (gdbarch,
|
||
sect_list->sect_name,
|
||
sect_list->size);
|
||
gdb_assert (regset && regset->collect_regset);
|
||
gdb_regset = xmalloc (sect_list->size);
|
||
regset->collect_regset (regset, regcache, -1,
|
||
gdb_regset, sect_list->size);
|
||
note_data = (char *) elfcore_write_register_note (obfd,
|
||
note_data,
|
||
note_size,
|
||
sect_list->sect_name,
|
||
gdb_regset,
|
||
sect_list->size);
|
||
xfree (gdb_regset);
|
||
sect_list++;
|
||
}
|
||
|
||
/* For architectures that does not have the struct core_regset_section
|
||
implemented, we use the old method. When all the architectures have
|
||
the new support, the code below should be deleted. */
|
||
else
|
||
{
|
||
if (core_regset_p
|
||
&& (regset = gdbarch_regset_from_core_section (gdbarch, ".reg2",
|
||
sizeof (fpregs))) != NULL
|
||
&& regset->collect_regset != NULL)
|
||
regset->collect_regset (regset, regcache, -1,
|
||
&fpregs, sizeof (fpregs));
|
||
else
|
||
fill_fpregset (regcache, &fpregs, -1);
|
||
|
||
note_data = (char *) elfcore_write_prfpreg (obfd,
|
||
note_data,
|
||
note_size,
|
||
&fpregs, sizeof (fpregs));
|
||
}
|
||
|
||
return note_data;
|
||
}
|
||
|
||
struct linux_nat_corefile_thread_data
|
||
{
|
||
bfd *obfd;
|
||
char *note_data;
|
||
int *note_size;
|
||
int num_notes;
|
||
};
|
||
|
||
/* Called by gdbthread.c once per thread. Records the thread's
|
||
register state for the corefile note section. */
|
||
|
||
static int
|
||
linux_nat_corefile_thread_callback (struct lwp_info *ti, void *data)
|
||
{
|
||
struct linux_nat_corefile_thread_data *args = data;
|
||
|
||
args->note_data = linux_nat_do_thread_registers (args->obfd,
|
||
ti->ptid,
|
||
args->note_data,
|
||
args->note_size);
|
||
args->num_notes++;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Records the register state for the corefile note section. */
|
||
|
||
static char *
|
||
linux_nat_do_registers (bfd *obfd, ptid_t ptid,
|
||
char *note_data, int *note_size)
|
||
{
|
||
return linux_nat_do_thread_registers (obfd,
|
||
ptid_build (ptid_get_pid (inferior_ptid),
|
||
ptid_get_pid (inferior_ptid),
|
||
0),
|
||
note_data, note_size);
|
||
}
|
||
|
||
/* Fills the "to_make_corefile_note" target vector. Builds the note
|
||
section for a corefile, and returns it in a malloc buffer. */
|
||
|
||
static char *
|
||
linux_nat_make_corefile_notes (bfd *obfd, int *note_size)
|
||
{
|
||
struct linux_nat_corefile_thread_data thread_args;
|
||
struct cleanup *old_chain;
|
||
/* The variable size must be >= sizeof (prpsinfo_t.pr_fname). */
|
||
char fname[16] = { '\0' };
|
||
/* The variable size must be >= sizeof (prpsinfo_t.pr_psargs). */
|
||
char psargs[80] = { '\0' };
|
||
char *note_data = NULL;
|
||
ptid_t current_ptid = inferior_ptid;
|
||
gdb_byte *auxv;
|
||
int auxv_len;
|
||
|
||
if (get_exec_file (0))
|
||
{
|
||
strncpy (fname, strrchr (get_exec_file (0), '/') + 1, sizeof (fname));
|
||
strncpy (psargs, get_exec_file (0), sizeof (psargs));
|
||
if (get_inferior_args ())
|
||
{
|
||
char *string_end;
|
||
char *psargs_end = psargs + sizeof (psargs);
|
||
|
||
/* linux_elfcore_write_prpsinfo () handles zero unterminated
|
||
strings fine. */
|
||
string_end = memchr (psargs, 0, sizeof (psargs));
|
||
if (string_end != NULL)
|
||
{
|
||
*string_end++ = ' ';
|
||
strncpy (string_end, get_inferior_args (),
|
||
psargs_end - string_end);
|
||
}
|
||
}
|
||
note_data = (char *) elfcore_write_prpsinfo (obfd,
|
||
note_data,
|
||
note_size, fname, psargs);
|
||
}
|
||
|
||
/* Dump information for threads. */
|
||
thread_args.obfd = obfd;
|
||
thread_args.note_data = note_data;
|
||
thread_args.note_size = note_size;
|
||
thread_args.num_notes = 0;
|
||
iterate_over_lwps (linux_nat_corefile_thread_callback, &thread_args);
|
||
if (thread_args.num_notes == 0)
|
||
{
|
||
/* iterate_over_threads didn't come up with any threads; just
|
||
use inferior_ptid. */
|
||
note_data = linux_nat_do_registers (obfd, inferior_ptid,
|
||
note_data, note_size);
|
||
}
|
||
else
|
||
{
|
||
note_data = thread_args.note_data;
|
||
}
|
||
|
||
auxv_len = target_read_alloc (¤t_target, TARGET_OBJECT_AUXV,
|
||
NULL, &auxv);
|
||
if (auxv_len > 0)
|
||
{
|
||
note_data = elfcore_write_note (obfd, note_data, note_size,
|
||
"CORE", NT_AUXV, auxv, auxv_len);
|
||
xfree (auxv);
|
||
}
|
||
|
||
make_cleanup (xfree, note_data);
|
||
return note_data;
|
||
}
|
||
|
||
/* Implement the "info proc" command. */
|
||
|
||
static void
|
||
linux_nat_info_proc_cmd (char *args, int from_tty)
|
||
{
|
||
long long pid = PIDGET (inferior_ptid);
|
||
FILE *procfile;
|
||
char **argv = NULL;
|
||
char buffer[MAXPATHLEN];
|
||
char fname1[MAXPATHLEN], fname2[MAXPATHLEN];
|
||
int cmdline_f = 1;
|
||
int cwd_f = 1;
|
||
int exe_f = 1;
|
||
int mappings_f = 0;
|
||
int environ_f = 0;
|
||
int status_f = 0;
|
||
int stat_f = 0;
|
||
int all = 0;
|
||
struct stat dummy;
|
||
|
||
if (args)
|
||
{
|
||
/* Break up 'args' into an argv array. */
|
||
if ((argv = buildargv (args)) == NULL)
|
||
nomem (0);
|
||
else
|
||
make_cleanup_freeargv (argv);
|
||
}
|
||
while (argv != NULL && *argv != NULL)
|
||
{
|
||
if (isdigit (argv[0][0]))
|
||
{
|
||
pid = strtoul (argv[0], NULL, 10);
|
||
}
|
||
else if (strncmp (argv[0], "mappings", strlen (argv[0])) == 0)
|
||
{
|
||
mappings_f = 1;
|
||
}
|
||
else if (strcmp (argv[0], "status") == 0)
|
||
{
|
||
status_f = 1;
|
||
}
|
||
else if (strcmp (argv[0], "stat") == 0)
|
||
{
|
||
stat_f = 1;
|
||
}
|
||
else if (strcmp (argv[0], "cmd") == 0)
|
||
{
|
||
cmdline_f = 1;
|
||
}
|
||
else if (strncmp (argv[0], "exe", strlen (argv[0])) == 0)
|
||
{
|
||
exe_f = 1;
|
||
}
|
||
else if (strcmp (argv[0], "cwd") == 0)
|
||
{
|
||
cwd_f = 1;
|
||
}
|
||
else if (strncmp (argv[0], "all", strlen (argv[0])) == 0)
|
||
{
|
||
all = 1;
|
||
}
|
||
else
|
||
{
|
||
/* [...] (future options here) */
|
||
}
|
||
argv++;
|
||
}
|
||
if (pid == 0)
|
||
error (_("No current process: you must name one."));
|
||
|
||
sprintf (fname1, "/proc/%lld", pid);
|
||
if (stat (fname1, &dummy) != 0)
|
||
error (_("No /proc directory: '%s'"), fname1);
|
||
|
||
printf_filtered (_("process %lld\n"), pid);
|
||
if (cmdline_f || all)
|
||
{
|
||
sprintf (fname1, "/proc/%lld/cmdline", pid);
|
||
if ((procfile = fopen (fname1, "r")) != NULL)
|
||
{
|
||
fgets (buffer, sizeof (buffer), procfile);
|
||
printf_filtered ("cmdline = '%s'\n", buffer);
|
||
fclose (procfile);
|
||
}
|
||
else
|
||
warning (_("unable to open /proc file '%s'"), fname1);
|
||
}
|
||
if (cwd_f || all)
|
||
{
|
||
sprintf (fname1, "/proc/%lld/cwd", pid);
|
||
memset (fname2, 0, sizeof (fname2));
|
||
if (readlink (fname1, fname2, sizeof (fname2)) > 0)
|
||
printf_filtered ("cwd = '%s'\n", fname2);
|
||
else
|
||
warning (_("unable to read link '%s'"), fname1);
|
||
}
|
||
if (exe_f || all)
|
||
{
|
||
sprintf (fname1, "/proc/%lld/exe", pid);
|
||
memset (fname2, 0, sizeof (fname2));
|
||
if (readlink (fname1, fname2, sizeof (fname2)) > 0)
|
||
printf_filtered ("exe = '%s'\n", fname2);
|
||
else
|
||
warning (_("unable to read link '%s'"), fname1);
|
||
}
|
||
if (mappings_f || all)
|
||
{
|
||
sprintf (fname1, "/proc/%lld/maps", pid);
|
||
if ((procfile = fopen (fname1, "r")) != NULL)
|
||
{
|
||
long long addr, endaddr, size, offset, inode;
|
||
char permissions[8], device[8], filename[MAXPATHLEN];
|
||
|
||
printf_filtered (_("Mapped address spaces:\n\n"));
|
||
if (gdbarch_addr_bit (current_gdbarch) == 32)
|
||
{
|
||
printf_filtered ("\t%10s %10s %10s %10s %7s\n",
|
||
"Start Addr",
|
||
" End Addr",
|
||
" Size", " Offset", "objfile");
|
||
}
|
||
else
|
||
{
|
||
printf_filtered (" %18s %18s %10s %10s %7s\n",
|
||
"Start Addr",
|
||
" End Addr",
|
||
" Size", " Offset", "objfile");
|
||
}
|
||
|
||
while (read_mapping (procfile, &addr, &endaddr, &permissions[0],
|
||
&offset, &device[0], &inode, &filename[0]))
|
||
{
|
||
size = endaddr - addr;
|
||
|
||
/* FIXME: carlton/2003-08-27: Maybe the printf_filtered
|
||
calls here (and possibly above) should be abstracted
|
||
out into their own functions? Andrew suggests using
|
||
a generic local_address_string instead to print out
|
||
the addresses; that makes sense to me, too. */
|
||
|
||
if (gdbarch_addr_bit (current_gdbarch) == 32)
|
||
{
|
||
printf_filtered ("\t%#10lx %#10lx %#10x %#10x %7s\n",
|
||
(unsigned long) addr, /* FIXME: pr_addr */
|
||
(unsigned long) endaddr,
|
||
(int) size,
|
||
(unsigned int) offset,
|
||
filename[0] ? filename : "");
|
||
}
|
||
else
|
||
{
|
||
printf_filtered (" %#18lx %#18lx %#10x %#10x %7s\n",
|
||
(unsigned long) addr, /* FIXME: pr_addr */
|
||
(unsigned long) endaddr,
|
||
(int) size,
|
||
(unsigned int) offset,
|
||
filename[0] ? filename : "");
|
||
}
|
||
}
|
||
|
||
fclose (procfile);
|
||
}
|
||
else
|
||
warning (_("unable to open /proc file '%s'"), fname1);
|
||
}
|
||
if (status_f || all)
|
||
{
|
||
sprintf (fname1, "/proc/%lld/status", pid);
|
||
if ((procfile = fopen (fname1, "r")) != NULL)
|
||
{
|
||
while (fgets (buffer, sizeof (buffer), procfile) != NULL)
|
||
puts_filtered (buffer);
|
||
fclose (procfile);
|
||
}
|
||
else
|
||
warning (_("unable to open /proc file '%s'"), fname1);
|
||
}
|
||
if (stat_f || all)
|
||
{
|
||
sprintf (fname1, "/proc/%lld/stat", pid);
|
||
if ((procfile = fopen (fname1, "r")) != NULL)
|
||
{
|
||
int itmp;
|
||
char ctmp;
|
||
long ltmp;
|
||
|
||
if (fscanf (procfile, "%d ", &itmp) > 0)
|
||
printf_filtered (_("Process: %d\n"), itmp);
|
||
if (fscanf (procfile, "(%[^)]) ", &buffer[0]) > 0)
|
||
printf_filtered (_("Exec file: %s\n"), buffer);
|
||
if (fscanf (procfile, "%c ", &ctmp) > 0)
|
||
printf_filtered (_("State: %c\n"), ctmp);
|
||
if (fscanf (procfile, "%d ", &itmp) > 0)
|
||
printf_filtered (_("Parent process: %d\n"), itmp);
|
||
if (fscanf (procfile, "%d ", &itmp) > 0)
|
||
printf_filtered (_("Process group: %d\n"), itmp);
|
||
if (fscanf (procfile, "%d ", &itmp) > 0)
|
||
printf_filtered (_("Session id: %d\n"), itmp);
|
||
if (fscanf (procfile, "%d ", &itmp) > 0)
|
||
printf_filtered (_("TTY: %d\n"), itmp);
|
||
if (fscanf (procfile, "%d ", &itmp) > 0)
|
||
printf_filtered (_("TTY owner process group: %d\n"), itmp);
|
||
if (fscanf (procfile, "%lu ", <mp) > 0)
|
||
printf_filtered (_("Flags: 0x%lx\n"), ltmp);
|
||
if (fscanf (procfile, "%lu ", <mp) > 0)
|
||
printf_filtered (_("Minor faults (no memory page): %lu\n"),
|
||
(unsigned long) ltmp);
|
||
if (fscanf (procfile, "%lu ", <mp) > 0)
|
||
printf_filtered (_("Minor faults, children: %lu\n"),
|
||
(unsigned long) ltmp);
|
||
if (fscanf (procfile, "%lu ", <mp) > 0)
|
||
printf_filtered (_("Major faults (memory page faults): %lu\n"),
|
||
(unsigned long) ltmp);
|
||
if (fscanf (procfile, "%lu ", <mp) > 0)
|
||
printf_filtered (_("Major faults, children: %lu\n"),
|
||
(unsigned long) ltmp);
|
||
if (fscanf (procfile, "%ld ", <mp) > 0)
|
||
printf_filtered (_("utime: %ld\n"), ltmp);
|
||
if (fscanf (procfile, "%ld ", <mp) > 0)
|
||
printf_filtered (_("stime: %ld\n"), ltmp);
|
||
if (fscanf (procfile, "%ld ", <mp) > 0)
|
||
printf_filtered (_("utime, children: %ld\n"), ltmp);
|
||
if (fscanf (procfile, "%ld ", <mp) > 0)
|
||
printf_filtered (_("stime, children: %ld\n"), ltmp);
|
||
if (fscanf (procfile, "%ld ", <mp) > 0)
|
||
printf_filtered (_("jiffies remaining in current time slice: %ld\n"),
|
||
ltmp);
|
||
if (fscanf (procfile, "%ld ", <mp) > 0)
|
||
printf_filtered (_("'nice' value: %ld\n"), ltmp);
|
||
if (fscanf (procfile, "%lu ", <mp) > 0)
|
||
printf_filtered (_("jiffies until next timeout: %lu\n"),
|
||
(unsigned long) ltmp);
|
||
if (fscanf (procfile, "%lu ", <mp) > 0)
|
||
printf_filtered (_("jiffies until next SIGALRM: %lu\n"),
|
||
(unsigned long) ltmp);
|
||
if (fscanf (procfile, "%ld ", <mp) > 0)
|
||
printf_filtered (_("start time (jiffies since system boot): %ld\n"),
|
||
ltmp);
|
||
if (fscanf (procfile, "%lu ", <mp) > 0)
|
||
printf_filtered (_("Virtual memory size: %lu\n"),
|
||
(unsigned long) ltmp);
|
||
if (fscanf (procfile, "%lu ", <mp) > 0)
|
||
printf_filtered (_("Resident set size: %lu\n"), (unsigned long) ltmp);
|
||
if (fscanf (procfile, "%lu ", <mp) > 0)
|
||
printf_filtered (_("rlim: %lu\n"), (unsigned long) ltmp);
|
||
if (fscanf (procfile, "%lu ", <mp) > 0)
|
||
printf_filtered (_("Start of text: 0x%lx\n"), ltmp);
|
||
if (fscanf (procfile, "%lu ", <mp) > 0)
|
||
printf_filtered (_("End of text: 0x%lx\n"), ltmp);
|
||
if (fscanf (procfile, "%lu ", <mp) > 0)
|
||
printf_filtered (_("Start of stack: 0x%lx\n"), ltmp);
|
||
#if 0 /* Don't know how architecture-dependent the rest is...
|
||
Anyway the signal bitmap info is available from "status". */
|
||
if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */
|
||
printf_filtered (_("Kernel stack pointer: 0x%lx\n"), ltmp);
|
||
if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */
|
||
printf_filtered (_("Kernel instr pointer: 0x%lx\n"), ltmp);
|
||
if (fscanf (procfile, "%ld ", <mp) > 0)
|
||
printf_filtered (_("Pending signals bitmap: 0x%lx\n"), ltmp);
|
||
if (fscanf (procfile, "%ld ", <mp) > 0)
|
||
printf_filtered (_("Blocked signals bitmap: 0x%lx\n"), ltmp);
|
||
if (fscanf (procfile, "%ld ", <mp) > 0)
|
||
printf_filtered (_("Ignored signals bitmap: 0x%lx\n"), ltmp);
|
||
if (fscanf (procfile, "%ld ", <mp) > 0)
|
||
printf_filtered (_("Catched signals bitmap: 0x%lx\n"), ltmp);
|
||
if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */
|
||
printf_filtered (_("wchan (system call): 0x%lx\n"), ltmp);
|
||
#endif
|
||
fclose (procfile);
|
||
}
|
||
else
|
||
warning (_("unable to open /proc file '%s'"), fname1);
|
||
}
|
||
}
|
||
|
||
/* Implement the to_xfer_partial interface for memory reads using the /proc
|
||
filesystem. Because we can use a single read() call for /proc, this
|
||
can be much more efficient than banging away at PTRACE_PEEKTEXT,
|
||
but it doesn't support writes. */
|
||
|
||
static LONGEST
|
||
linux_proc_xfer_partial (struct target_ops *ops, enum target_object object,
|
||
const char *annex, gdb_byte *readbuf,
|
||
const gdb_byte *writebuf,
|
||
ULONGEST offset, LONGEST len)
|
||
{
|
||
LONGEST ret;
|
||
int fd;
|
||
char filename[64];
|
||
|
||
if (object != TARGET_OBJECT_MEMORY || !readbuf)
|
||
return 0;
|
||
|
||
/* Don't bother for one word. */
|
||
if (len < 3 * sizeof (long))
|
||
return 0;
|
||
|
||
/* 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", PIDGET (inferior_ptid));
|
||
fd = open (filename, O_RDONLY | O_LARGEFILE);
|
||
if (fd == -1)
|
||
return 0;
|
||
|
||
/* 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, readbuf, len, offset) != len)
|
||
#else
|
||
if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len)
|
||
#endif
|
||
ret = 0;
|
||
else
|
||
ret = len;
|
||
|
||
close (fd);
|
||
return ret;
|
||
}
|
||
|
||
/* Parse LINE as a signal set and add its set bits to SIGS. */
|
||
|
||
static void
|
||
add_line_to_sigset (const char *line, sigset_t *sigs)
|
||
{
|
||
int len = strlen (line) - 1;
|
||
const char *p;
|
||
int signum;
|
||
|
||
if (line[len] != '\n')
|
||
error (_("Could not parse signal set: %s"), line);
|
||
|
||
p = line;
|
||
signum = len * 4;
|
||
while (len-- > 0)
|
||
{
|
||
int digit;
|
||
|
||
if (*p >= '0' && *p <= '9')
|
||
digit = *p - '0';
|
||
else if (*p >= 'a' && *p <= 'f')
|
||
digit = *p - 'a' + 10;
|
||
else
|
||
error (_("Could not parse signal set: %s"), line);
|
||
|
||
signum -= 4;
|
||
|
||
if (digit & 1)
|
||
sigaddset (sigs, signum + 1);
|
||
if (digit & 2)
|
||
sigaddset (sigs, signum + 2);
|
||
if (digit & 4)
|
||
sigaddset (sigs, signum + 3);
|
||
if (digit & 8)
|
||
sigaddset (sigs, signum + 4);
|
||
|
||
p++;
|
||
}
|
||
}
|
||
|
||
/* Find process PID's pending signals from /proc/pid/status and set
|
||
SIGS to match. */
|
||
|
||
void
|
||
linux_proc_pending_signals (int pid, sigset_t *pending, sigset_t *blocked, sigset_t *ignored)
|
||
{
|
||
FILE *procfile;
|
||
char buffer[MAXPATHLEN], fname[MAXPATHLEN];
|
||
int signum;
|
||
|
||
sigemptyset (pending);
|
||
sigemptyset (blocked);
|
||
sigemptyset (ignored);
|
||
sprintf (fname, "/proc/%d/status", pid);
|
||
procfile = fopen (fname, "r");
|
||
if (procfile == NULL)
|
||
error (_("Could not open %s"), fname);
|
||
|
||
while (fgets (buffer, MAXPATHLEN, procfile) != NULL)
|
||
{
|
||
/* Normal queued signals are on the SigPnd line in the status
|
||
file. However, 2.6 kernels also have a "shared" pending
|
||
queue for delivering signals to a thread group, so check for
|
||
a ShdPnd line also.
|
||
|
||
Unfortunately some Red Hat kernels include the shared pending
|
||
queue but not the ShdPnd status field. */
|
||
|
||
if (strncmp (buffer, "SigPnd:\t", 8) == 0)
|
||
add_line_to_sigset (buffer + 8, pending);
|
||
else if (strncmp (buffer, "ShdPnd:\t", 8) == 0)
|
||
add_line_to_sigset (buffer + 8, pending);
|
||
else if (strncmp (buffer, "SigBlk:\t", 8) == 0)
|
||
add_line_to_sigset (buffer + 8, blocked);
|
||
else if (strncmp (buffer, "SigIgn:\t", 8) == 0)
|
||
add_line_to_sigset (buffer + 8, ignored);
|
||
}
|
||
|
||
fclose (procfile);
|
||
}
|
||
|
||
static LONGEST
|
||
linux_xfer_partial (struct target_ops *ops, enum target_object object,
|
||
const char *annex, gdb_byte *readbuf,
|
||
const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
|
||
{
|
||
LONGEST xfer;
|
||
|
||
if (object == TARGET_OBJECT_AUXV)
|
||
return procfs_xfer_auxv (ops, object, annex, readbuf, writebuf,
|
||
offset, len);
|
||
|
||
xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf,
|
||
offset, len);
|
||
if (xfer != 0)
|
||
return xfer;
|
||
|
||
return super_xfer_partial (ops, object, annex, readbuf, writebuf,
|
||
offset, len);
|
||
}
|
||
|
||
/* Create a prototype generic GNU/Linux target. The client can override
|
||
it with local methods. */
|
||
|
||
static void
|
||
linux_target_install_ops (struct target_ops *t)
|
||
{
|
||
t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint;
|
||
t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint;
|
||
t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint;
|
||
t->to_pid_to_exec_file = linux_child_pid_to_exec_file;
|
||
t->to_post_startup_inferior = linux_child_post_startup_inferior;
|
||
t->to_post_attach = linux_child_post_attach;
|
||
t->to_follow_fork = linux_child_follow_fork;
|
||
t->to_find_memory_regions = linux_nat_find_memory_regions;
|
||
t->to_make_corefile_notes = linux_nat_make_corefile_notes;
|
||
|
||
super_xfer_partial = t->to_xfer_partial;
|
||
t->to_xfer_partial = linux_xfer_partial;
|
||
}
|
||
|
||
struct target_ops *
|
||
linux_target (void)
|
||
{
|
||
struct target_ops *t;
|
||
|
||
t = inf_ptrace_target ();
|
||
linux_target_install_ops (t);
|
||
|
||
return t;
|
||
}
|
||
|
||
struct target_ops *
|
||
linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int))
|
||
{
|
||
struct target_ops *t;
|
||
|
||
t = inf_ptrace_trad_target (register_u_offset);
|
||
linux_target_install_ops (t);
|
||
|
||
return t;
|
||
}
|
||
|
||
/* target_is_async_p implementation. */
|
||
|
||
static int
|
||
linux_nat_is_async_p (void)
|
||
{
|
||
/* NOTE: palves 2008-03-21: We're only async when the user requests
|
||
it explicitly with the "maintenance set target-async" command.
|
||
Someday, linux will always be async. */
|
||
if (!target_async_permitted)
|
||
return 0;
|
||
|
||
return 1;
|
||
}
|
||
|
||
/* target_can_async_p implementation. */
|
||
|
||
static int
|
||
linux_nat_can_async_p (void)
|
||
{
|
||
/* NOTE: palves 2008-03-21: We're only async when the user requests
|
||
it explicitly with the "maintenance set target-async" command.
|
||
Someday, linux will always be async. */
|
||
if (!target_async_permitted)
|
||
return 0;
|
||
|
||
/* See target.h/target_async_mask. */
|
||
return linux_nat_async_mask_value;
|
||
}
|
||
|
||
static int
|
||
linux_nat_supports_non_stop (void)
|
||
{
|
||
return 1;
|
||
}
|
||
|
||
/* target_async_mask implementation. */
|
||
|
||
static int
|
||
linux_nat_async_mask (int mask)
|
||
{
|
||
int current_state;
|
||
current_state = linux_nat_async_mask_value;
|
||
|
||
if (current_state != mask)
|
||
{
|
||
if (mask == 0)
|
||
{
|
||
linux_nat_async (NULL, 0);
|
||
linux_nat_async_mask_value = mask;
|
||
}
|
||
else
|
||
{
|
||
linux_nat_async_mask_value = mask;
|
||
linux_nat_async (inferior_event_handler, 0);
|
||
}
|
||
}
|
||
|
||
return current_state;
|
||
}
|
||
|
||
/* Pop an event from the event pipe. */
|
||
|
||
static int
|
||
linux_nat_event_pipe_pop (int* ptr_status, int* ptr_options)
|
||
{
|
||
struct waitpid_result event = {0};
|
||
int ret;
|
||
|
||
do
|
||
{
|
||
ret = read (linux_nat_event_pipe[0], &event, sizeof (event));
|
||
}
|
||
while (ret == -1 && errno == EINTR);
|
||
|
||
gdb_assert (ret == sizeof (event));
|
||
|
||
*ptr_status = event.status;
|
||
*ptr_options = event.options;
|
||
|
||
linux_nat_num_queued_events--;
|
||
|
||
return event.pid;
|
||
}
|
||
|
||
/* Push an event into the event pipe. */
|
||
|
||
static void
|
||
linux_nat_event_pipe_push (int pid, int status, int options)
|
||
{
|
||
int ret;
|
||
struct waitpid_result event = {0};
|
||
event.pid = pid;
|
||
event.status = status;
|
||
event.options = options;
|
||
|
||
do
|
||
{
|
||
ret = write (linux_nat_event_pipe[1], &event, sizeof (event));
|
||
gdb_assert ((ret == -1 && errno == EINTR) || ret == sizeof (event));
|
||
} while (ret == -1 && errno == EINTR);
|
||
|
||
linux_nat_num_queued_events++;
|
||
}
|
||
|
||
static void
|
||
get_pending_events (void)
|
||
{
|
||
int status, options, pid;
|
||
|
||
if (!target_async_permitted
|
||
|| linux_nat_async_events_state != sigchld_async)
|
||
internal_error (__FILE__, __LINE__,
|
||
"get_pending_events called with async masked");
|
||
|
||
while (1)
|
||
{
|
||
status = 0;
|
||
options = __WCLONE | WNOHANG;
|
||
|
||
do
|
||
{
|
||
pid = waitpid (-1, &status, options);
|
||
}
|
||
while (pid == -1 && errno == EINTR);
|
||
|
||
if (pid <= 0)
|
||
{
|
||
options = WNOHANG;
|
||
do
|
||
{
|
||
pid = waitpid (-1, &status, options);
|
||
}
|
||
while (pid == -1 && errno == EINTR);
|
||
}
|
||
|
||
if (pid <= 0)
|
||
/* No more children reporting events. */
|
||
break;
|
||
|
||
if (debug_linux_nat_async)
|
||
fprintf_unfiltered (gdb_stdlog, "\
|
||
get_pending_events: pid(%d), status(%x), options (%x)\n",
|
||
pid, status, options);
|
||
|
||
linux_nat_event_pipe_push (pid, status, options);
|
||
}
|
||
|
||
if (debug_linux_nat_async)
|
||
fprintf_unfiltered (gdb_stdlog, "\
|
||
get_pending_events: linux_nat_num_queued_events(%d)\n",
|
||
linux_nat_num_queued_events);
|
||
}
|
||
|
||
/* SIGCHLD handler for async mode. */
|
||
|
||
static void
|
||
async_sigchld_handler (int signo)
|
||
{
|
||
if (debug_linux_nat_async)
|
||
fprintf_unfiltered (gdb_stdlog, "async_sigchld_handler\n");
|
||
|
||
get_pending_events ();
|
||
}
|
||
|
||
/* Set SIGCHLD handling state to STATE. Returns previous state. */
|
||
|
||
static enum sigchld_state
|
||
linux_nat_async_events (enum sigchld_state state)
|
||
{
|
||
enum sigchld_state current_state = linux_nat_async_events_state;
|
||
|
||
if (debug_linux_nat_async)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LNAE: state(%d): linux_nat_async_events_state(%d), "
|
||
"linux_nat_num_queued_events(%d)\n",
|
||
state, linux_nat_async_events_state,
|
||
linux_nat_num_queued_events);
|
||
|
||
if (current_state != state)
|
||
{
|
||
sigset_t mask;
|
||
sigemptyset (&mask);
|
||
sigaddset (&mask, SIGCHLD);
|
||
|
||
/* Always block before changing state. */
|
||
sigprocmask (SIG_BLOCK, &mask, NULL);
|
||
|
||
/* Set new state. */
|
||
linux_nat_async_events_state = state;
|
||
|
||
switch (state)
|
||
{
|
||
case sigchld_sync:
|
||
{
|
||
/* Block target events. */
|
||
sigprocmask (SIG_BLOCK, &mask, NULL);
|
||
sigaction (SIGCHLD, &sync_sigchld_action, NULL);
|
||
/* Get events out of queue, and make them available to
|
||
queued_waitpid / my_waitpid. */
|
||
pipe_to_local_event_queue ();
|
||
}
|
||
break;
|
||
case sigchld_async:
|
||
{
|
||
/* Unblock target events for async mode. */
|
||
|
||
sigprocmask (SIG_BLOCK, &mask, NULL);
|
||
|
||
/* Put events we already waited on, in the pipe first, so
|
||
events are FIFO. */
|
||
local_event_queue_to_pipe ();
|
||
/* While in masked async, we may have not collected all
|
||
the pending events. Get them out now. */
|
||
get_pending_events ();
|
||
|
||
/* Let'em come. */
|
||
sigaction (SIGCHLD, &async_sigchld_action, NULL);
|
||
sigprocmask (SIG_UNBLOCK, &mask, NULL);
|
||
}
|
||
break;
|
||
case sigchld_default:
|
||
{
|
||
/* SIGCHLD default mode. */
|
||
sigaction (SIGCHLD, &sigchld_default_action, NULL);
|
||
|
||
/* Get events out of queue, and make them available to
|
||
queued_waitpid / my_waitpid. */
|
||
pipe_to_local_event_queue ();
|
||
|
||
/* Unblock SIGCHLD. */
|
||
sigprocmask (SIG_UNBLOCK, &mask, NULL);
|
||
}
|
||
break;
|
||
}
|
||
}
|
||
|
||
return current_state;
|
||
}
|
||
|
||
static int async_terminal_is_ours = 1;
|
||
|
||
/* target_terminal_inferior implementation. */
|
||
|
||
static void
|
||
linux_nat_terminal_inferior (void)
|
||
{
|
||
if (!target_is_async_p ())
|
||
{
|
||
/* Async mode is disabled. */
|
||
terminal_inferior ();
|
||
return;
|
||
}
|
||
|
||
/* GDB should never give the terminal to the inferior, if the
|
||
inferior is running in the background (run&, continue&, etc.).
|
||
This check can be removed when the common code is fixed. */
|
||
if (!sync_execution)
|
||
return;
|
||
|
||
terminal_inferior ();
|
||
|
||
if (!async_terminal_is_ours)
|
||
return;
|
||
|
||
delete_file_handler (input_fd);
|
||
async_terminal_is_ours = 0;
|
||
set_sigint_trap ();
|
||
}
|
||
|
||
/* target_terminal_ours implementation. */
|
||
|
||
void
|
||
linux_nat_terminal_ours (void)
|
||
{
|
||
if (!target_is_async_p ())
|
||
{
|
||
/* Async mode is disabled. */
|
||
terminal_ours ();
|
||
return;
|
||
}
|
||
|
||
/* GDB should never give the terminal to the inferior if the
|
||
inferior is running in the background (run&, continue&, etc.),
|
||
but claiming it sure should. */
|
||
terminal_ours ();
|
||
|
||
if (!sync_execution)
|
||
return;
|
||
|
||
if (async_terminal_is_ours)
|
||
return;
|
||
|
||
clear_sigint_trap ();
|
||
add_file_handler (input_fd, stdin_event_handler, 0);
|
||
async_terminal_is_ours = 1;
|
||
}
|
||
|
||
static void (*async_client_callback) (enum inferior_event_type event_type,
|
||
void *context);
|
||
static void *async_client_context;
|
||
|
||
static void
|
||
linux_nat_async_file_handler (int error, gdb_client_data client_data)
|
||
{
|
||
async_client_callback (INF_REG_EVENT, async_client_context);
|
||
}
|
||
|
||
/* target_async implementation. */
|
||
|
||
static void
|
||
linux_nat_async (void (*callback) (enum inferior_event_type event_type,
|
||
void *context), void *context)
|
||
{
|
||
if (linux_nat_async_mask_value == 0 || !target_async_permitted)
|
||
internal_error (__FILE__, __LINE__,
|
||
"Calling target_async when async is masked");
|
||
|
||
if (callback != NULL)
|
||
{
|
||
async_client_callback = callback;
|
||
async_client_context = context;
|
||
add_file_handler (linux_nat_event_pipe[0],
|
||
linux_nat_async_file_handler, NULL);
|
||
|
||
linux_nat_async_events (sigchld_async);
|
||
}
|
||
else
|
||
{
|
||
async_client_callback = callback;
|
||
async_client_context = context;
|
||
|
||
linux_nat_async_events (sigchld_sync);
|
||
delete_file_handler (linux_nat_event_pipe[0]);
|
||
}
|
||
return;
|
||
}
|
||
|
||
static int
|
||
send_sigint_callback (struct lwp_info *lp, void *data)
|
||
{
|
||
/* Use is_running instead of !lp->stopped, because the lwp may be
|
||
stopped due to an internal event, and we want to interrupt it in
|
||
that case too. What we want is to check if the thread is stopped
|
||
from the point of view of the user. */
|
||
if (is_running (lp->ptid))
|
||
kill_lwp (GET_LWP (lp->ptid), SIGINT);
|
||
return 0;
|
||
}
|
||
|
||
static void
|
||
linux_nat_stop (ptid_t ptid)
|
||
{
|
||
if (non_stop)
|
||
{
|
||
if (ptid_equal (ptid, minus_one_ptid))
|
||
iterate_over_lwps (send_sigint_callback, &ptid);
|
||
else
|
||
{
|
||
struct lwp_info *lp = find_lwp_pid (ptid);
|
||
send_sigint_callback (lp, NULL);
|
||
}
|
||
}
|
||
else
|
||
linux_ops->to_stop (ptid);
|
||
}
|
||
|
||
void
|
||
linux_nat_add_target (struct target_ops *t)
|
||
{
|
||
/* Save the provided single-threaded target. We save this in a separate
|
||
variable because another target we've inherited from (e.g. inf-ptrace)
|
||
may have saved a pointer to T; we want to use it for the final
|
||
process stratum target. */
|
||
linux_ops_saved = *t;
|
||
linux_ops = &linux_ops_saved;
|
||
|
||
/* Override some methods for multithreading. */
|
||
t->to_create_inferior = linux_nat_create_inferior;
|
||
t->to_attach = linux_nat_attach;
|
||
t->to_detach = linux_nat_detach;
|
||
t->to_resume = linux_nat_resume;
|
||
t->to_wait = linux_nat_wait;
|
||
t->to_xfer_partial = linux_nat_xfer_partial;
|
||
t->to_kill = linux_nat_kill;
|
||
t->to_mourn_inferior = linux_nat_mourn_inferior;
|
||
t->to_thread_alive = linux_nat_thread_alive;
|
||
t->to_pid_to_str = linux_nat_pid_to_str;
|
||
t->to_has_thread_control = tc_schedlock;
|
||
|
||
t->to_can_async_p = linux_nat_can_async_p;
|
||
t->to_is_async_p = linux_nat_is_async_p;
|
||
t->to_supports_non_stop = linux_nat_supports_non_stop;
|
||
t->to_async = linux_nat_async;
|
||
t->to_async_mask = linux_nat_async_mask;
|
||
t->to_terminal_inferior = linux_nat_terminal_inferior;
|
||
t->to_terminal_ours = linux_nat_terminal_ours;
|
||
|
||
/* Methods for non-stop support. */
|
||
t->to_stop = linux_nat_stop;
|
||
|
||
/* We don't change the stratum; this target will sit at
|
||
process_stratum and thread_db will set at thread_stratum. This
|
||
is a little strange, since this is a multi-threaded-capable
|
||
target, but we want to be on the stack below thread_db, and we
|
||
also want to be used for single-threaded processes. */
|
||
|
||
add_target (t);
|
||
|
||
/* TODO: Eliminate this and have libthread_db use
|
||
find_target_beneath. */
|
||
thread_db_init (t);
|
||
}
|
||
|
||
/* Register a method to call whenever a new thread is attached. */
|
||
void
|
||
linux_nat_set_new_thread (struct target_ops *t, void (*new_thread) (ptid_t))
|
||
{
|
||
/* Save the pointer. We only support a single registered instance
|
||
of the GNU/Linux native target, so we do not need to map this to
|
||
T. */
|
||
linux_nat_new_thread = new_thread;
|
||
}
|
||
|
||
/* Return the saved siginfo associated with PTID. */
|
||
struct siginfo *
|
||
linux_nat_get_siginfo (ptid_t ptid)
|
||
{
|
||
struct lwp_info *lp = find_lwp_pid (ptid);
|
||
|
||
gdb_assert (lp != NULL);
|
||
|
||
return &lp->siginfo;
|
||
}
|
||
|
||
/* Enable/Disable async mode. */
|
||
|
||
static void
|
||
linux_nat_setup_async (void)
|
||
{
|
||
if (pipe (linux_nat_event_pipe) == -1)
|
||
internal_error (__FILE__, __LINE__,
|
||
"creating event pipe failed.");
|
||
fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK);
|
||
fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK);
|
||
}
|
||
|
||
void
|
||
_initialize_linux_nat (void)
|
||
{
|
||
sigset_t mask;
|
||
|
||
add_info ("proc", linux_nat_info_proc_cmd, _("\
|
||
Show /proc process information about any running process.\n\
|
||
Specify any process id, or use the program being debugged by default.\n\
|
||
Specify any of the following keywords for detailed info:\n\
|
||
mappings -- list of mapped memory regions.\n\
|
||
stat -- list a bunch of random process info.\n\
|
||
status -- list a different bunch of random process info.\n\
|
||
all -- list all available /proc info."));
|
||
|
||
add_setshow_zinteger_cmd ("lin-lwp", class_maintenance,
|
||
&debug_linux_nat, _("\
|
||
Set debugging of GNU/Linux lwp module."), _("\
|
||
Show debugging of GNU/Linux lwp module."), _("\
|
||
Enables printf debugging output."),
|
||
NULL,
|
||
show_debug_linux_nat,
|
||
&setdebuglist, &showdebuglist);
|
||
|
||
add_setshow_zinteger_cmd ("lin-lwp-async", class_maintenance,
|
||
&debug_linux_nat_async, _("\
|
||
Set debugging of GNU/Linux async lwp module."), _("\
|
||
Show debugging of GNU/Linux async lwp module."), _("\
|
||
Enables printf debugging output."),
|
||
NULL,
|
||
show_debug_linux_nat_async,
|
||
&setdebuglist, &showdebuglist);
|
||
|
||
/* Get the default SIGCHLD action. Used while forking an inferior
|
||
(see linux_nat_create_inferior/linux_nat_async_events). */
|
||
sigaction (SIGCHLD, NULL, &sigchld_default_action);
|
||
|
||
/* Block SIGCHLD by default. Doing this early prevents it getting
|
||
unblocked if an exception is thrown due to an error while the
|
||
inferior is starting (sigsetjmp/siglongjmp). */
|
||
sigemptyset (&mask);
|
||
sigaddset (&mask, SIGCHLD);
|
||
sigprocmask (SIG_BLOCK, &mask, NULL);
|
||
|
||
/* Save this mask as the default. */
|
||
sigprocmask (SIG_SETMASK, NULL, &normal_mask);
|
||
|
||
/* The synchronous SIGCHLD handler. */
|
||
sync_sigchld_action.sa_handler = sigchld_handler;
|
||
sigemptyset (&sync_sigchld_action.sa_mask);
|
||
sync_sigchld_action.sa_flags = SA_RESTART;
|
||
|
||
/* Make it the default. */
|
||
sigaction (SIGCHLD, &sync_sigchld_action, NULL);
|
||
|
||
/* Make sure we don't block SIGCHLD during a sigsuspend. */
|
||
sigprocmask (SIG_SETMASK, NULL, &suspend_mask);
|
||
sigdelset (&suspend_mask, SIGCHLD);
|
||
|
||
/* SIGCHLD handler for async mode. */
|
||
async_sigchld_action.sa_handler = async_sigchld_handler;
|
||
sigemptyset (&async_sigchld_action.sa_mask);
|
||
async_sigchld_action.sa_flags = SA_RESTART;
|
||
|
||
linux_nat_setup_async ();
|
||
|
||
add_setshow_boolean_cmd ("disable-randomization", class_support,
|
||
&disable_randomization, _("\
|
||
Set disabling of debuggee's virtual address space randomization."), _("\
|
||
Show disabling of debuggee's virtual address space randomization."), _("\
|
||
When this mode is on (which is the default), randomization of the virtual\n\
|
||
address space is disabled. Standalone programs run with the randomization\n\
|
||
enabled by default on some platforms."),
|
||
&set_disable_randomization,
|
||
&show_disable_randomization,
|
||
&setlist, &showlist);
|
||
}
|
||
|
||
|
||
/* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
|
||
the GNU/Linux Threads library and therefore doesn't really belong
|
||
here. */
|
||
|
||
/* Read variable NAME in the target and return its value if found.
|
||
Otherwise return zero. It is assumed that the type of the variable
|
||
is `int'. */
|
||
|
||
static int
|
||
get_signo (const char *name)
|
||
{
|
||
struct minimal_symbol *ms;
|
||
int signo;
|
||
|
||
ms = lookup_minimal_symbol (name, NULL, NULL);
|
||
if (ms == NULL)
|
||
return 0;
|
||
|
||
if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo,
|
||
sizeof (signo)) != 0)
|
||
return 0;
|
||
|
||
return signo;
|
||
}
|
||
|
||
/* Return the set of signals used by the threads library in *SET. */
|
||
|
||
void
|
||
lin_thread_get_thread_signals (sigset_t *set)
|
||
{
|
||
struct sigaction action;
|
||
int restart, cancel;
|
||
sigset_t blocked_mask;
|
||
|
||
sigemptyset (&blocked_mask);
|
||
sigemptyset (set);
|
||
|
||
restart = get_signo ("__pthread_sig_restart");
|
||
cancel = get_signo ("__pthread_sig_cancel");
|
||
|
||
/* LinuxThreads normally uses the first two RT signals, but in some legacy
|
||
cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
|
||
not provide any way for the debugger to query the signal numbers -
|
||
fortunately they don't change! */
|
||
|
||
if (restart == 0)
|
||
restart = __SIGRTMIN;
|
||
|
||
if (cancel == 0)
|
||
cancel = __SIGRTMIN + 1;
|
||
|
||
sigaddset (set, restart);
|
||
sigaddset (set, cancel);
|
||
|
||
/* The GNU/Linux Threads library makes terminating threads send a
|
||
special "cancel" signal instead of SIGCHLD. Make sure we catch
|
||
those (to prevent them from terminating GDB itself, which is
|
||
likely to be their default action) and treat them the same way as
|
||
SIGCHLD. */
|
||
|
||
action.sa_handler = sigchld_handler;
|
||
sigemptyset (&action.sa_mask);
|
||
action.sa_flags = SA_RESTART;
|
||
sigaction (cancel, &action, NULL);
|
||
|
||
/* We block the "cancel" signal throughout this code ... */
|
||
sigaddset (&blocked_mask, cancel);
|
||
sigprocmask (SIG_BLOCK, &blocked_mask, NULL);
|
||
|
||
/* ... except during a sigsuspend. */
|
||
sigdelset (&suspend_mask, cancel);
|
||
}
|