58aecb61a1
(lin_lwp_attach_lwp, linux_nat_attach, wait_lwp, child_wait) (linux_nat_wait, kill_wait_callback): Use my_waitpid. (_initialize_linux_nat, lin_thread_get_thread_signals): Use SA_RESTART.
3179 lines
89 KiB
C
3179 lines
89 KiB
C
/* GNU/Linux native-dependent code common to multiple platforms.
|
||
|
||
Copyright 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
|
||
|
||
This file is part of GDB.
|
||
|
||
This program is free software; you can redistribute it and/or modify
|
||
it under the terms of the GNU General Public License as published by
|
||
the Free Software Foundation; either version 2 of the License, or
|
||
(at your option) any later version.
|
||
|
||
This program is distributed in the hope that it will be useful,
|
||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
GNU General Public License for more details.
|
||
|
||
You should have received a copy of the GNU General Public License
|
||
along with this program; if not, write to the Free Software
|
||
Foundation, Inc., 59 Temple Place - Suite 330,
|
||
Boston, MA 02111-1307, USA. */
|
||
|
||
#include "defs.h"
|
||
#include "inferior.h"
|
||
#include "target.h"
|
||
#include "gdb_string.h"
|
||
#include "gdb_wait.h"
|
||
#include "gdb_assert.h"
|
||
#ifdef HAVE_TKILL_SYSCALL
|
||
#include <unistd.h>
|
||
#include <sys/syscall.h>
|
||
#endif
|
||
#include <sys/ptrace.h>
|
||
#include "linux-nat.h"
|
||
#include "gdbthread.h"
|
||
#include "gdbcmd.h"
|
||
#include "regcache.h"
|
||
#include <sys/param.h> /* for MAXPATHLEN */
|
||
#include <sys/procfs.h> /* for elf_gregset etc. */
|
||
#include "elf-bfd.h" /* for elfcore_write_* */
|
||
#include "gregset.h" /* for gregset */
|
||
#include "gdbcore.h" /* for get_exec_file */
|
||
#include <ctype.h> /* for isdigit */
|
||
#include "gdbthread.h" /* for struct thread_info etc. */
|
||
#include "gdb_stat.h" /* for struct stat */
|
||
#include <fcntl.h> /* for O_RDONLY */
|
||
|
||
#ifndef O_LARGEFILE
|
||
#define O_LARGEFILE 0
|
||
#endif
|
||
|
||
/* If the system headers did not provide the constants, hard-code the normal
|
||
values. */
|
||
#ifndef PTRACE_EVENT_FORK
|
||
|
||
#define PTRACE_SETOPTIONS 0x4200
|
||
#define PTRACE_GETEVENTMSG 0x4201
|
||
|
||
/* options set using PTRACE_SETOPTIONS */
|
||
#define PTRACE_O_TRACESYSGOOD 0x00000001
|
||
#define PTRACE_O_TRACEFORK 0x00000002
|
||
#define PTRACE_O_TRACEVFORK 0x00000004
|
||
#define PTRACE_O_TRACECLONE 0x00000008
|
||
#define PTRACE_O_TRACEEXEC 0x00000010
|
||
#define PTRACE_O_TRACEVFORKDONE 0x00000020
|
||
#define PTRACE_O_TRACEEXIT 0x00000040
|
||
|
||
/* Wait extended result codes for the above trace options. */
|
||
#define PTRACE_EVENT_FORK 1
|
||
#define PTRACE_EVENT_VFORK 2
|
||
#define PTRACE_EVENT_CLONE 3
|
||
#define PTRACE_EVENT_EXEC 4
|
||
#define PTRACE_EVENT_VFORK_DONE 5
|
||
#define PTRACE_EVENT_EXIT 6
|
||
|
||
#endif /* PTRACE_EVENT_FORK */
|
||
|
||
/* We can't always assume that this flag is available, but all systems
|
||
with the ptrace event handlers also have __WALL, so it's safe to use
|
||
here. */
|
||
#ifndef __WALL
|
||
#define __WALL 0x40000000 /* Wait for any child. */
|
||
#endif
|
||
|
||
static int debug_linux_nat;
|
||
static void
|
||
show_debug_linux_nat (struct ui_file *file, int from_tty,
|
||
struct cmd_list_element *c, const char *value)
|
||
{
|
||
fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"),
|
||
value);
|
||
}
|
||
|
||
static int linux_parent_pid;
|
||
|
||
struct simple_pid_list
|
||
{
|
||
int pid;
|
||
struct simple_pid_list *next;
|
||
};
|
||
struct simple_pid_list *stopped_pids;
|
||
|
||
/* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACEFORK
|
||
can not be used, 1 if it can. */
|
||
|
||
static int linux_supports_tracefork_flag = -1;
|
||
|
||
/* If we have PTRACE_O_TRACEFORK, this flag indicates whether we also have
|
||
PTRACE_O_TRACEVFORKDONE. */
|
||
|
||
static int linux_supports_tracevforkdone_flag = -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)
|
||
{
|
||
struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list));
|
||
new_pid->pid = pid;
|
||
new_pid->next = *listp;
|
||
*listp = new_pid;
|
||
}
|
||
|
||
static int
|
||
pull_pid_from_list (struct simple_pid_list **listp, int pid)
|
||
{
|
||
struct simple_pid_list **p;
|
||
|
||
for (p = listp; *p != NULL; p = &(*p)->next)
|
||
if ((*p)->pid == pid)
|
||
{
|
||
struct simple_pid_list *next = (*p)->next;
|
||
xfree (*p);
|
||
*p = next;
|
||
return 1;
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
void
|
||
linux_record_stopped_pid (int pid)
|
||
{
|
||
add_to_pid_list (&stopped_pids, pid);
|
||
}
|
||
|
||
|
||
/* 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. */
|
||
|
||
static int
|
||
my_waitpid (int pid, int *status, int flags)
|
||
{
|
||
int 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
|
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the new child's PID, then we assume that we can. */
|
||
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||
static void
|
||
linux_test_for_tracefork (int original_pid)
|
||
{
|
||
int child_pid, ret, status;
|
||
long second_pid;
|
||
|
||
linux_supports_tracefork_flag = 0;
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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"));
|
||
return;
|
||
}
|
||
|
||
ret = my_waitpid (child_pid, &status, 0);
|
||
if (ret != child_pid)
|
||
warning (_("linux_test_for_tracefork: failed to wait for killed child"));
|
||
else if (!WIFSIGNALED (status))
|
||
warning (_("linux_test_for_tracefork: unexpected wait status 0x%x from "
|
||
"killed child"), status);
|
||
|
||
return;
|
||
}
|
||
|
||
/* Check whether PTRACE_O_TRACEVFORKDONE is available. */
|
||
ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0,
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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"));
|
||
}
|
||
}
|
||
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);
|
||
}
|
||
|
||
/* 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);
|
||
}
|
||
|
||
void
|
||
child_post_attach (int pid)
|
||
{
|
||
linux_enable_event_reporting (pid_to_ptid (pid));
|
||
}
|
||
|
||
void
|
||
linux_child_post_startup_inferior (ptid_t ptid)
|
||
{
|
||
linux_enable_event_reporting (ptid);
|
||
}
|
||
|
||
#ifndef LINUX_CHILD_POST_STARTUP_INFERIOR
|
||
void
|
||
child_post_startup_inferior (ptid_t ptid)
|
||
{
|
||
linux_child_post_startup_inferior (ptid);
|
||
}
|
||
#endif
|
||
|
||
int
|
||
child_follow_fork (int follow_child)
|
||
{
|
||
ptid_t last_ptid;
|
||
struct target_waitstatus last_status;
|
||
int has_vforked;
|
||
int parent_pid, child_pid;
|
||
|
||
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 = 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);
|
||
|
||
if (debug_linux_nat)
|
||
{
|
||
target_terminal_ours ();
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"Detaching after fork from child process %d.\n",
|
||
child_pid);
|
||
}
|
||
|
||
ptrace (PTRACE_DETACH, child_pid, 0, 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 (debug_linux_nat)
|
||
{
|
||
target_terminal_ours ();
|
||
fprintf_unfiltered (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
|
||
target_detach (NULL, 0);
|
||
|
||
inferior_ptid = pid_to_ptid (child_pid);
|
||
push_target (&deprecated_child_ops);
|
||
|
||
/* Reset breakpoints in the child as appropriate. */
|
||
follow_inferior_reset_breakpoints ();
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
ptid_t
|
||
linux_handle_extended_wait (int pid, int status,
|
||
struct target_waitstatus *ourstatus)
|
||
{
|
||
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))
|
||
{
|
||
/* 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) || WSTOPSIG (status) != SIGSTOP)
|
||
internal_error (__FILE__, __LINE__,
|
||
_("wait returned unexpected status 0x%x"), status);
|
||
}
|
||
|
||
if (event == PTRACE_EVENT_FORK)
|
||
ourstatus->kind = TARGET_WAITKIND_FORKED;
|
||
else if (event == PTRACE_EVENT_VFORK)
|
||
ourstatus->kind = TARGET_WAITKIND_VFORKED;
|
||
else
|
||
ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
|
||
|
||
ourstatus->value.related_pid = new_pid;
|
||
return inferior_ptid;
|
||
}
|
||
|
||
if (event == PTRACE_EVENT_EXEC)
|
||
{
|
||
ourstatus->kind = TARGET_WAITKIND_EXECD;
|
||
ourstatus->value.execd_pathname
|
||
= xstrdup (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;
|
||
}
|
||
|
||
return inferior_ptid;
|
||
}
|
||
|
||
internal_error (__FILE__, __LINE__,
|
||
_("unknown ptrace event %d"), event);
|
||
}
|
||
|
||
|
||
void
|
||
child_insert_fork_catchpoint (int pid)
|
||
{
|
||
if (! linux_supports_tracefork (pid))
|
||
error (_("Your system does not support fork catchpoints."));
|
||
}
|
||
|
||
void
|
||
child_insert_vfork_catchpoint (int pid)
|
||
{
|
||
if (!linux_supports_tracefork (pid))
|
||
error (_("Your system does not support vfork catchpoints."));
|
||
}
|
||
|
||
void
|
||
child_insert_exec_catchpoint (int pid)
|
||
{
|
||
if (!linux_supports_tracefork (pid))
|
||
error (_("Your system does not support exec catchpoints."));
|
||
}
|
||
|
||
void
|
||
kill_inferior (void)
|
||
{
|
||
int status;
|
||
int pid = PIDGET (inferior_ptid);
|
||
struct target_waitstatus last;
|
||
ptid_t last_ptid;
|
||
int ret;
|
||
|
||
if (pid == 0)
|
||
return;
|
||
|
||
/* 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, last.value.related_pid, 0, 0);
|
||
wait (&status);
|
||
}
|
||
|
||
/* Kill the current process. */
|
||
ptrace (PT_KILL, pid, 0, 0);
|
||
ret = wait (&status);
|
||
|
||
/* We might get a SIGCHLD instead of an exit status. This is
|
||
aggravated by the first kill above - a child has just died. */
|
||
|
||
while (ret == pid && WIFSTOPPED (status))
|
||
{
|
||
ptrace (PT_KILL, pid, 0, 0);
|
||
ret = wait (&status);
|
||
}
|
||
|
||
target_mourn_inferior ();
|
||
}
|
||
|
||
/* 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. */
|
||
static struct lwp_info *lwp_list;
|
||
|
||
/* Number of LWPs in the list. */
|
||
static int num_lwps;
|
||
|
||
/* Non-zero if we're running in "threaded" mode. */
|
||
static int threaded;
|
||
|
||
|
||
#define GET_LWP(ptid) ptid_get_lwp (ptid)
|
||
#define GET_PID(ptid) ptid_get_pid (ptid)
|
||
#define is_lwp(ptid) (GET_LWP (ptid) != 0)
|
||
#define BUILD_LWP(lwp, pid) ptid_build (pid, lwp, 0)
|
||
|
||
/* If the last reported event was a SIGTRAP, this variable is set to
|
||
the process id of the LWP/thread that got it. */
|
||
ptid_t trap_ptid;
|
||
|
||
|
||
/* This module's target-specific operations. */
|
||
static struct target_ops linux_nat_ops;
|
||
|
||
/* Since we cannot wait (in linux_nat_wait) for the initial process and
|
||
any cloned processes with a single call to waitpid, we have to use
|
||
the WNOHANG flag and call waitpid in a loop. To optimize
|
||
things a bit we use `sigsuspend' to wake us up when a process has
|
||
something to report (it will send us a SIGCHLD if it has). To make
|
||
this work we have to juggle with the signal mask. We save the
|
||
original signal mask such that we can restore it before creating a
|
||
new process in order to avoid blocking certain signals in the
|
||
inferior. We then block SIGCHLD during the waitpid/sigsuspend
|
||
loop. */
|
||
|
||
/* 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;
|
||
|
||
/* Signals to block to make that sigsuspend work. */
|
||
static sigset_t blocked_mask;
|
||
|
||
|
||
/* Prototypes for local functions. */
|
||
static int stop_wait_callback (struct lwp_info *lp, void *data);
|
||
static int linux_nat_thread_alive (ptid_t ptid);
|
||
|
||
/* 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;
|
||
threaded = 0;
|
||
}
|
||
|
||
/* Add the LWP specified by PID to the list. If this causes the
|
||
number of LWPs to become larger than one, go into "threaded" mode.
|
||
Return a pointer to the structure describing the new 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;
|
||
if (++num_lwps > 1)
|
||
threaded = 1;
|
||
|
||
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;
|
||
|
||
/* We don't go back to "non-threaded" mode if the number of threads
|
||
becomes less than two. */
|
||
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;
|
||
}
|
||
|
||
/* Attach to the LWP specified by PID. If VERBOSE is non-zero, print
|
||
a message telling the user that a new LWP has been added to the
|
||
process. */
|
||
|
||
void
|
||
lin_lwp_attach_lwp (ptid_t ptid, int verbose)
|
||
{
|
||
struct lwp_info *lp, *found_lp;
|
||
|
||
gdb_assert (is_lwp (ptid));
|
||
|
||
/* Make sure SIGCHLD is blocked. We don't want SIGCHLD events
|
||
to interrupt either the ptrace() or waitpid() calls below. */
|
||
if (!sigismember (&blocked_mask, SIGCHLD))
|
||
{
|
||
sigaddset (&blocked_mask, SIGCHLD);
|
||
sigprocmask (SIG_BLOCK, &blocked_mask, NULL);
|
||
}
|
||
|
||
if (verbose)
|
||
printf_filtered (_("[New %s]\n"), target_pid_to_str (ptid));
|
||
|
||
found_lp = lp = find_lwp_pid (ptid);
|
||
if (lp == NULL)
|
||
lp = add_lwp (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) && found_lp == NULL)
|
||
{
|
||
pid_t pid;
|
||
int status;
|
||
|
||
if (ptrace (PTRACE_ATTACH, GET_LWP (ptid), 0, 0) < 0)
|
||
error (_("Can't attach %s: %s"), target_pid_to_str (ptid),
|
||
safe_strerror (errno));
|
||
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
|
||
target_pid_to_str (ptid));
|
||
|
||
pid = my_waitpid (GET_LWP (ptid), &status, 0);
|
||
if (pid == -1 && errno == ECHILD)
|
||
{
|
||
/* Try again with __WCLONE to check cloned processes. */
|
||
pid = my_waitpid (GET_LWP (ptid), &status, __WCLONE);
|
||
lp->cloned = 1;
|
||
}
|
||
|
||
gdb_assert (pid == GET_LWP (ptid)
|
||
&& WIFSTOPPED (status) && WSTOPSIG (status));
|
||
|
||
child_post_attach (pid);
|
||
|
||
lp->stopped = 1;
|
||
|
||
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 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. */
|
||
lp->stopped = 1;
|
||
}
|
||
}
|
||
|
||
static void
|
||
linux_nat_attach (char *args, int from_tty)
|
||
{
|
||
struct lwp_info *lp;
|
||
pid_t pid;
|
||
int status;
|
||
|
||
/* FIXME: We should probably accept a list of process id's, and
|
||
attach all of them. */
|
||
deprecated_child_ops.to_attach (args, from_tty);
|
||
|
||
/* Add the initial process as the first LWP to the list. */
|
||
lp = add_lwp (BUILD_LWP (GET_PID (inferior_ptid), GET_PID (inferior_ptid)));
|
||
|
||
/* 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. */
|
||
pid = my_waitpid (GET_PID (inferior_ptid), &status, 0);
|
||
if (pid == -1 && errno == ECHILD)
|
||
{
|
||
warning (_("%s is a cloned process"), target_pid_to_str (inferior_ptid));
|
||
|
||
/* Try again with __WCLONE to check cloned processes. */
|
||
pid = my_waitpid (GET_PID (inferior_ptid), &status, __WCLONE);
|
||
lp->cloned = 1;
|
||
}
|
||
|
||
gdb_assert (pid == GET_PID (inferior_ptid)
|
||
&& WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP);
|
||
|
||
lp->stopped = 1;
|
||
|
||
/* Fake the SIGSTOP that core GDB expects. */
|
||
lp->status = W_STOPCODE (SIGSTOP);
|
||
lp->resumed = 1;
|
||
if (debug_linux_nat)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLA: waitpid %ld, faking SIGSTOP\n", (long) pid);
|
||
}
|
||
}
|
||
|
||
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));
|
||
|
||
while (lp->signalled && lp->stopped)
|
||
{
|
||
errno = 0;
|
||
if (ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0,
|
||
WSTOPSIG (lp->status)) < 0)
|
||
error (_("Can't continue %s: %s"), target_pid_to_str (lp->ptid),
|
||
safe_strerror (errno));
|
||
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"DC: PTRACE_CONTINUE (%s, 0, %s) (OK)\n",
|
||
target_pid_to_str (lp->ptid),
|
||
status_to_str (lp->status));
|
||
|
||
lp->stopped = 0;
|
||
lp->signalled = 0;
|
||
lp->status = 0;
|
||
/* FIXME drow/2003-08-26: There was a call to stop_wait_callback
|
||
here. But since lp->signalled was cleared above,
|
||
stop_wait_callback didn't do anything; the process was left
|
||
running. Shouldn't we be waiting for it to stop?
|
||
I've removed the call, since stop_wait_callback now does do
|
||
something when called with lp->signalled == 0. */
|
||
|
||
gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status));
|
||
}
|
||
|
||
/* 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))
|
||
{
|
||
errno = 0;
|
||
if (ptrace (PTRACE_DETACH, GET_LWP (lp->ptid), 0,
|
||
WSTOPSIG (lp->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)
|
||
{
|
||
iterate_over_lwps (detach_callback, NULL);
|
||
|
||
/* Only the initial process should be left right now. */
|
||
gdb_assert (num_lwps == 1);
|
||
|
||
trap_ptid = null_ptid;
|
||
|
||
/* Destroy LWP info; it's no longer valid. */
|
||
init_lwp_list ();
|
||
|
||
/* Restore the original signal mask. */
|
||
sigprocmask (SIG_SETMASK, &normal_mask, NULL);
|
||
sigemptyset (&blocked_mask);
|
||
|
||
inferior_ptid = pid_to_ptid (GET_PID (inferior_ptid));
|
||
deprecated_child_ops.to_detach (args, from_tty);
|
||
}
|
||
|
||
/* Resume LP. */
|
||
|
||
static int
|
||
resume_callback (struct lwp_info *lp, void *data)
|
||
{
|
||
if (lp->stopped && lp->status == 0)
|
||
{
|
||
struct thread_info *tp;
|
||
|
||
child_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;
|
||
}
|
||
|
||
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;
|
||
|
||
/* A specific PTID means `step only this process id'. */
|
||
resume_all = (PIDGET (ptid) == -1);
|
||
|
||
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);
|
||
if (lp)
|
||
{
|
||
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. */
|
||
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);
|
||
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);
|
||
|
||
child_resume (ptid, step, signo);
|
||
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");
|
||
}
|
||
|
||
/* 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. Most of the work we
|
||
just pass off to linux_handle_extended_wait, but if it reports 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. */
|
||
|
||
static int
|
||
linux_nat_handle_extended (struct lwp_info *lp, int status)
|
||
{
|
||
linux_handle_extended_wait (GET_LWP (lp->ptid), status,
|
||
&lp->waitstatus);
|
||
|
||
/* TARGET_WAITKIND_SPURIOUS is used to indicate clone events. */
|
||
if (lp->waitstatus.kind == TARGET_WAITKIND_SPURIOUS)
|
||
{
|
||
struct lwp_info *new_lp;
|
||
new_lp = add_lwp (BUILD_LWP (lp->waitstatus.value.related_pid,
|
||
GET_PID (inferior_ptid)));
|
||
new_lp->cloned = 1;
|
||
new_lp->stopped = 1;
|
||
|
||
lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
|
||
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLHE: 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;
|
||
}
|
||
|
||
/* 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)
|
||
{
|
||
if (in_thread_list (lp->ptid))
|
||
{
|
||
/* Core GDB cannot deal with us deleting the current thread. */
|
||
if (!ptid_equal (lp->ptid, inferior_ptid))
|
||
delete_thread (lp->ptid);
|
||
printf_unfiltered (_("[%s exited]\n"),
|
||
target_pid_to_str (lp->ptid));
|
||
}
|
||
|
||
delete_lwp (lp->ptid);
|
||
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_nat_handle_extended (lp, status))
|
||
return wait_lwp (lp);
|
||
}
|
||
|
||
return status;
|
||
}
|
||
|
||
/* 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;
|
||
}
|
||
|
||
/* Wait until LP is stopped. If DATA is non-null it is interpreted as
|
||
a pointer to a set of signals to be flushed immediately. */
|
||
|
||
static int
|
||
stop_wait_callback (struct lwp_info *lp, void *data)
|
||
{
|
||
sigset_t *flush_mask = data;
|
||
|
||
if (!lp->stopped)
|
||
{
|
||
int status;
|
||
|
||
status = wait_lwp (lp);
|
||
if (status == 0)
|
||
return 0;
|
||
|
||
/* Ignore any signals in FLUSH_MASK. */
|
||
if (flush_mask && sigismember (flush_mask, WSTOPSIG (status)))
|
||
{
|
||
if (!lp->signalled)
|
||
{
|
||
lp->stopped = 1;
|
||
return 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)\n",
|
||
target_pid_to_str (lp->ptid),
|
||
errno ? safe_strerror (errno) : "OK");
|
||
|
||
return stop_wait_callback (lp, flush_mask);
|
||
}
|
||
|
||
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. */
|
||
|
||
/* 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 the SIGTRAP for handling by linux_nat_wait. */
|
||
stop_wait_callback (lp, data);
|
||
/* 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, data);
|
||
/* 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 == 0)
|
||
lp->status = status;
|
||
else
|
||
{
|
||
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));
|
||
}
|
||
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;
|
||
}
|
||
|
||
/* Check whether PID has any pending signals in FLUSH_MASK. If so set
|
||
the appropriate bits in PENDING, and return 1 - otherwise return 0. */
|
||
|
||
static int
|
||
linux_nat_has_pending (int pid, sigset_t *pending, sigset_t *flush_mask)
|
||
{
|
||
sigset_t blocked, ignored;
|
||
int i;
|
||
|
||
linux_proc_pending_signals (pid, pending, &blocked, &ignored);
|
||
|
||
if (!flush_mask)
|
||
return 0;
|
||
|
||
for (i = 1; i < NSIG; i++)
|
||
if (sigismember (pending, i))
|
||
if (!sigismember (flush_mask, i)
|
||
|| sigismember (&blocked, i)
|
||
|| sigismember (&ignored, i))
|
||
sigdelset (pending, i);
|
||
|
||
if (sigisemptyset (pending))
|
||
return 0;
|
||
|
||
return 1;
|
||
}
|
||
|
||
/* DATA is interpreted as a mask of signals to flush. If LP has
|
||
signals pending, and they are all in the flush mask, then arrange
|
||
to flush them. LP should be stopped, as should all other threads
|
||
it might share a signal queue with. */
|
||
|
||
static int
|
||
flush_callback (struct lwp_info *lp, void *data)
|
||
{
|
||
sigset_t *flush_mask = data;
|
||
sigset_t pending, intersection, blocked, ignored;
|
||
int pid, status;
|
||
|
||
/* Normally, when an LWP exits, it is removed from the LWP list. The
|
||
last LWP isn't removed till later, however. So if there is only
|
||
one LWP on the list, make sure it's alive. */
|
||
if (lwp_list == lp && lp->next == NULL)
|
||
if (!linux_nat_thread_alive (lp->ptid))
|
||
return 0;
|
||
|
||
/* Just because the LWP is stopped doesn't mean that new signals
|
||
can't arrive from outside, so this function must be careful of
|
||
race conditions. However, because all threads are stopped, we
|
||
can assume that the pending mask will not shrink unless we resume
|
||
the LWP, and that it will then get another signal. We can't
|
||
control which one, however. */
|
||
|
||
if (lp->status)
|
||
{
|
||
if (debug_linux_nat)
|
||
printf_unfiltered (_("FC: LP has pending status %06x\n"), lp->status);
|
||
if (WIFSTOPPED (lp->status) && sigismember (flush_mask, WSTOPSIG (lp->status)))
|
||
lp->status = 0;
|
||
}
|
||
|
||
while (linux_nat_has_pending (GET_LWP (lp->ptid), &pending, flush_mask))
|
||
{
|
||
int ret;
|
||
|
||
errno = 0;
|
||
ret = ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stderr,
|
||
"FC: Sent PTRACE_CONT, ret %d %d\n", ret, errno);
|
||
|
||
lp->stopped = 0;
|
||
stop_wait_callback (lp, flush_mask);
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stderr,
|
||
"FC: Wait finished; saved status is %d\n",
|
||
lp->status);
|
||
}
|
||
|
||
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 LWPs that have a SIGTRAP event pending. */
|
||
if (lp->status != 0
|
||
&& 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 LWPs that have a SIGTRAP event pending. */
|
||
if (lp->status != 0
|
||
&& WIFSTOPPED (lp->status) && WSTOPSIG (lp->status) == SIGTRAP)
|
||
if ((*selector)-- == 0)
|
||
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
|
||
&& breakpoint_inserted_here_p (read_pc_pid (lp->ptid) -
|
||
DECR_PC_AFTER_BREAK))
|
||
{
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"CBC: Push back breakpoint for %s\n",
|
||
target_pid_to_str (lp->ptid));
|
||
|
||
/* Back up the PC if necessary. */
|
||
if (DECR_PC_AFTER_BREAK)
|
||
write_pc_pid (read_pc_pid (lp->ptid) - DECR_PC_AFTER_BREAK, lp->ptid);
|
||
|
||
/* 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 origional 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;
|
||
}
|
||
|
||
#ifdef CHILD_WAIT
|
||
|
||
/* We need to override child_wait to support attaching to cloned
|
||
processes, since a normal wait (as done by the default version)
|
||
ignores those processes. */
|
||
|
||
/* Wait for child PTID to do something. Return id of the child,
|
||
minus_one_ptid in case of error; store status into *OURSTATUS. */
|
||
|
||
ptid_t
|
||
child_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
|
||
{
|
||
int save_errno;
|
||
int status;
|
||
pid_t pid;
|
||
|
||
ourstatus->kind = TARGET_WAITKIND_IGNORE;
|
||
|
||
do
|
||
{
|
||
set_sigint_trap (); /* Causes SIGINT to be passed on to the
|
||
attached process. */
|
||
set_sigio_trap ();
|
||
|
||
pid = my_waitpid (GET_PID (ptid), &status, 0);
|
||
if (pid == -1 && errno == ECHILD)
|
||
/* Try again with __WCLONE to check cloned processes. */
|
||
pid = my_waitpid (GET_PID (ptid), &status, __WCLONE);
|
||
|
||
if (debug_linux_nat)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"CW: waitpid %ld received %s\n",
|
||
(long) pid, status_to_str (status));
|
||
}
|
||
|
||
save_errno = errno;
|
||
|
||
/* Make sure we don't report an event for the exit of the
|
||
original program, if we've detached from it. */
|
||
if (pid != -1 && !WIFSTOPPED (status) && pid != GET_PID (inferior_ptid))
|
||
{
|
||
pid = -1;
|
||
save_errno = EINTR;
|
||
}
|
||
|
||
/* Check for stop events reported by a process we didn't already
|
||
know about - in this case, anything other than inferior_ptid.
|
||
|
||
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 we want to handle debugging of
|
||
CLONE_PTRACE processes we need to do more here, i.e. switch
|
||
to multi-threaded mode. */
|
||
if (pid != -1 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP
|
||
&& pid != GET_PID (inferior_ptid))
|
||
{
|
||
linux_record_stopped_pid (pid);
|
||
pid = -1;
|
||
save_errno = EINTR;
|
||
}
|
||
|
||
/* Handle GNU/Linux's extended waitstatus for trace events. */
|
||
if (pid != -1 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP
|
||
&& status >> 16 != 0)
|
||
{
|
||
linux_handle_extended_wait (pid, status, ourstatus);
|
||
|
||
/* If we see a clone event, detach the child, and don't
|
||
report the event. It would be nice to offer some way to
|
||
switch into a non-thread-db based threaded mode at this
|
||
point. */
|
||
if (ourstatus->kind == TARGET_WAITKIND_SPURIOUS)
|
||
{
|
||
ptrace (PTRACE_DETACH, ourstatus->value.related_pid, 0, 0);
|
||
ourstatus->kind = TARGET_WAITKIND_IGNORE;
|
||
ptrace (PTRACE_CONT, pid, 0, 0);
|
||
pid = -1;
|
||
save_errno = EINTR;
|
||
}
|
||
}
|
||
|
||
clear_sigio_trap ();
|
||
clear_sigint_trap ();
|
||
}
|
||
while (pid == -1 && save_errno == EINTR);
|
||
|
||
if (pid == -1)
|
||
{
|
||
warning (_("Child process unexpectedly missing: %s"),
|
||
safe_strerror (errno));
|
||
|
||
/* Claim it exited with unknown signal. */
|
||
ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
|
||
ourstatus->value.sig = TARGET_SIGNAL_UNKNOWN;
|
||
return minus_one_ptid;
|
||
}
|
||
|
||
if (ourstatus->kind == TARGET_WAITKIND_IGNORE)
|
||
store_waitstatus (ourstatus, status);
|
||
|
||
return pid_to_ptid (pid);
|
||
}
|
||
|
||
#endif
|
||
|
||
/* 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;
|
||
}
|
||
|
||
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);
|
||
sigset_t flush_mask;
|
||
|
||
sigemptyset (&flush_mask);
|
||
|
||
/* Make sure SIGCHLD is blocked. */
|
||
if (!sigismember (&blocked_mask, SIGCHLD))
|
||
{
|
||
sigaddset (&blocked_mask, SIGCHLD);
|
||
sigprocmask (SIG_BLOCK, &blocked_mask, NULL);
|
||
}
|
||
|
||
retry:
|
||
|
||
/* Make sure there is at least one LWP that has been resumed, at
|
||
least if there are any LWPs at all. */
|
||
gdb_assert (num_lwps == 0 || 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)
|
||
{
|
||
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 fine 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 ();
|
||
child_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);
|
||
}
|
||
|
||
set_sigint_trap (); /* Causes SIGINT to be passed on to the
|
||
attached process. */
|
||
set_sigio_trap ();
|
||
|
||
while (status == 0)
|
||
{
|
||
pid_t lwpid;
|
||
|
||
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 = 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 = 0;
|
||
continue;
|
||
}
|
||
|
||
/* 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)
|
||
{
|
||
status = 0;
|
||
continue;
|
||
}
|
||
|
||
/* 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;
|
||
|
||
if (threaded)
|
||
{
|
||
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);
|
||
printf_unfiltered (_("[New %s]\n"),
|
||
target_pid_to_str (lp->ptid));
|
||
}
|
||
}
|
||
|
||
/* 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_nat_handle_extended (lp, status))
|
||
{
|
||
status = 0;
|
||
continue;
|
||
}
|
||
}
|
||
|
||
/* Check if the thread has exited. */
|
||
if ((WIFEXITED (status) || WIFSIGNALED (status)) && num_lwps > 1)
|
||
{
|
||
if (in_thread_list (lp->ptid))
|
||
{
|
||
/* Core GDB cannot deal with us deleting the current
|
||
thread. */
|
||
if (!ptid_equal (lp->ptid, inferior_ptid))
|
||
delete_thread (lp->ptid);
|
||
printf_unfiltered (_("[%s exited]\n"),
|
||
target_pid_to_str (lp->ptid));
|
||
}
|
||
|
||
/* 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));
|
||
|
||
delete_lwp (lp->ptid);
|
||
|
||
/* 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)
|
||
{
|
||
/* Make sure there is at least one thread running. */
|
||
gdb_assert (iterate_over_lwps (running_callback, NULL));
|
||
|
||
/* Discard the event. */
|
||
status = 0;
|
||
continue;
|
||
}
|
||
}
|
||
|
||
/* 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 (in_thread_list (lp->ptid))
|
||
{
|
||
/* Core GDB cannot deal with us deleting the current
|
||
thread. */
|
||
if (!ptid_equal (lp->ptid, inferior_ptid))
|
||
delete_thread (lp->ptid);
|
||
printf_unfiltered (_("[%s exited]\n"),
|
||
target_pid_to_str (lp->ptid));
|
||
}
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLW: %s exited.\n",
|
||
target_pid_to_str (lp->ptid));
|
||
|
||
delete_lwp (lp->ptid);
|
||
|
||
/* Make sure there is at least one thread running. */
|
||
gdb_assert (iterate_over_lwps (running_callback, NULL));
|
||
|
||
/* Discard the event. */
|
||
status = 0;
|
||
continue;
|
||
}
|
||
|
||
/* 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 ();
|
||
child_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. */
|
||
status = 0;
|
||
continue;
|
||
}
|
||
|
||
break;
|
||
}
|
||
|
||
if (pid == -1)
|
||
{
|
||
/* Alternate between checking cloned and uncloned processes. */
|
||
options ^= __WCLONE;
|
||
|
||
/* And suspend every time we have checked both. */
|
||
if (options & __WCLONE)
|
||
sigsuspend (&suspend_mask);
|
||
}
|
||
|
||
/* We shouldn't end up here unless we want to try again. */
|
||
gdb_assert (status == 0);
|
||
}
|
||
|
||
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 (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 ();
|
||
child_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 LWP's
|
||
will receive it. Since we only want to report it once,
|
||
we try to flush it from all LWPs except this one. */
|
||
sigaddset (&flush_mask, SIGINT);
|
||
}
|
||
}
|
||
|
||
/* 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));
|
||
|
||
/* 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, &flush_mask);
|
||
iterate_over_lwps (flush_callback, &flush_mask);
|
||
|
||
/* 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 we're not running in "threaded" mode, we'll report the bare
|
||
process id. */
|
||
|
||
if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP)
|
||
{
|
||
trap_ptid = (threaded ? lp->ptid : pid_to_ptid (GET_LWP (lp->ptid)));
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLW: trap_ptid is %s.\n",
|
||
target_pid_to_str (trap_ptid));
|
||
}
|
||
else
|
||
trap_ptid = null_ptid;
|
||
|
||
if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
|
||
{
|
||
*ourstatus = lp->waitstatus;
|
||
lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
|
||
}
|
||
else
|
||
store_waitstatus (ourstatus, status);
|
||
|
||
return (threaded ? lp->ptid : pid_to_ptid (GET_LWP (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 && debug_linux_nat)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"KWC: wait %s received unknown.\n",
|
||
target_pid_to_str (lp->ptid));
|
||
}
|
||
}
|
||
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 && debug_linux_nat)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"KWC: wait %s received unk.\n",
|
||
target_pid_to_str (lp->ptid));
|
||
}
|
||
}
|
||
while (pid == GET_LWP (lp->ptid));
|
||
|
||
gdb_assert (pid == -1 && errno == ECHILD);
|
||
return 0;
|
||
}
|
||
|
||
static void
|
||
linux_nat_kill (void)
|
||
{
|
||
/* 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_create_inferior (char *exec_file, char *allargs, char **env,
|
||
int from_tty)
|
||
{
|
||
deprecated_child_ops.to_create_inferior (exec_file, allargs, env, from_tty);
|
||
}
|
||
|
||
static void
|
||
linux_nat_mourn_inferior (void)
|
||
{
|
||
trap_ptid = null_ptid;
|
||
|
||
/* Destroy LWP info; it's no longer valid. */
|
||
init_lwp_list ();
|
||
|
||
/* Restore the original signal mask. */
|
||
sigprocmask (SIG_SETMASK, &normal_mask, NULL);
|
||
sigemptyset (&blocked_mask);
|
||
|
||
deprecated_child_ops.to_mourn_inferior ();
|
||
}
|
||
|
||
static int
|
||
linux_nat_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len, int write,
|
||
struct mem_attrib *attrib, struct target_ops *target)
|
||
{
|
||
struct cleanup *old_chain = save_inferior_ptid ();
|
||
int xfer;
|
||
|
||
if (is_lwp (inferior_ptid))
|
||
inferior_ptid = pid_to_ptid (GET_LWP (inferior_ptid));
|
||
|
||
xfer = linux_proc_xfer_memory (memaddr, myaddr, len, write, attrib, target);
|
||
if (xfer == 0)
|
||
xfer = child_xfer_memory (memaddr, myaddr, len, write, attrib, target);
|
||
|
||
do_cleanups (old_chain);
|
||
return xfer;
|
||
}
|
||
|
||
static int
|
||
linux_nat_thread_alive (ptid_t ptid)
|
||
{
|
||
gdb_assert (is_lwp (ptid));
|
||
|
||
errno = 0;
|
||
ptrace (PTRACE_PEEKUSER, GET_LWP (ptid), 0, 0);
|
||
if (debug_linux_nat)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"LLTA: PTRACE_PEEKUSER %s, 0, 0 (%s)\n",
|
||
target_pid_to_str (ptid),
|
||
errno ? safe_strerror (errno) : "OK");
|
||
if (errno)
|
||
return 0;
|
||
|
||
return 1;
|
||
}
|
||
|
||
static char *
|
||
linux_nat_pid_to_str (ptid_t ptid)
|
||
{
|
||
static char buf[64];
|
||
|
||
if (is_lwp (ptid))
|
||
{
|
||
snprintf (buf, sizeof (buf), "LWP %ld", GET_LWP (ptid));
|
||
return buf;
|
||
}
|
||
|
||
return normal_pid_to_str (ptid);
|
||
}
|
||
|
||
static void
|
||
init_linux_nat_ops (void)
|
||
{
|
||
#if 0
|
||
linux_nat_ops.to_open = linux_nat_open;
|
||
#endif
|
||
linux_nat_ops.to_shortname = "lwp-layer";
|
||
linux_nat_ops.to_longname = "lwp-layer";
|
||
linux_nat_ops.to_doc = "Low level threads support (LWP layer)";
|
||
linux_nat_ops.to_attach = linux_nat_attach;
|
||
linux_nat_ops.to_detach = linux_nat_detach;
|
||
linux_nat_ops.to_resume = linux_nat_resume;
|
||
linux_nat_ops.to_wait = linux_nat_wait;
|
||
/* fetch_inferior_registers and store_inferior_registers will
|
||
honor the LWP id, so we can use them directly. */
|
||
linux_nat_ops.to_fetch_registers = fetch_inferior_registers;
|
||
linux_nat_ops.to_store_registers = store_inferior_registers;
|
||
linux_nat_ops.deprecated_xfer_memory = linux_nat_xfer_memory;
|
||
linux_nat_ops.to_kill = linux_nat_kill;
|
||
linux_nat_ops.to_create_inferior = linux_nat_create_inferior;
|
||
linux_nat_ops.to_mourn_inferior = linux_nat_mourn_inferior;
|
||
linux_nat_ops.to_thread_alive = linux_nat_thread_alive;
|
||
linux_nat_ops.to_pid_to_str = linux_nat_pid_to_str;
|
||
linux_nat_ops.to_post_startup_inferior = child_post_startup_inferior;
|
||
linux_nat_ops.to_post_attach = child_post_attach;
|
||
linux_nat_ops.to_insert_fork_catchpoint = child_insert_fork_catchpoint;
|
||
linux_nat_ops.to_insert_vfork_catchpoint = child_insert_vfork_catchpoint;
|
||
linux_nat_ops.to_insert_exec_catchpoint = child_insert_exec_catchpoint;
|
||
|
||
linux_nat_ops.to_stratum = thread_stratum;
|
||
linux_nat_ops.to_has_thread_control = tc_schedlock;
|
||
linux_nat_ops.to_magic = OPS_MAGIC;
|
||
}
|
||
|
||
static void
|
||
sigchld_handler (int signo)
|
||
{
|
||
/* 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. */
|
||
|
||
char *
|
||
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);
|
||
|
||
if (ret > 0 && ret != EOF && *inode != 0)
|
||
{
|
||
/* 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);
|
||
}
|
||
else
|
||
{
|
||
filename[0] = '\0'; /* no filename */
|
||
fscanf (mapfile, "\n");
|
||
}
|
||
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 && 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;
|
||
#ifdef FILL_FPXREGSET
|
||
gdb_fpxregset_t fpxregs;
|
||
#endif
|
||
unsigned long lwp = ptid_get_lwp (ptid);
|
||
|
||
fill_gregset (&gregs, -1);
|
||
note_data = (char *) elfcore_write_prstatus (obfd,
|
||
note_data,
|
||
note_size,
|
||
lwp,
|
||
stop_signal, &gregs);
|
||
|
||
fill_fpregset (&fpregs, -1);
|
||
note_data = (char *) elfcore_write_prfpreg (obfd,
|
||
note_data,
|
||
note_size,
|
||
&fpregs, sizeof (fpregs));
|
||
#ifdef FILL_FPXREGSET
|
||
fill_fpxregset (&fpxregs, -1);
|
||
note_data = (char *) elfcore_write_prxfpreg (obfd,
|
||
note_data,
|
||
note_size,
|
||
&fpxregs, sizeof (fpxregs));
|
||
#endif
|
||
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;
|
||
ptid_t saved_ptid = inferior_ptid;
|
||
|
||
inferior_ptid = ti->ptid;
|
||
registers_changed ();
|
||
target_fetch_registers (-1); /* FIXME should not be necessary;
|
||
fill_gregset should do it automatically. */
|
||
args->note_data = linux_nat_do_thread_registers (args->obfd,
|
||
ti->ptid,
|
||
args->note_data,
|
||
args->note_size);
|
||
args->num_notes++;
|
||
inferior_ptid = saved_ptid;
|
||
registers_changed ();
|
||
target_fetch_registers (-1); /* FIXME should not be necessary;
|
||
fill_gregset should do it automatically. */
|
||
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)
|
||
{
|
||
registers_changed ();
|
||
target_fetch_registers (-1); /* FIXME should not be necessary;
|
||
fill_gregset should do it automatically. */
|
||
return linux_nat_do_thread_registers (obfd,
|
||
ptid_build (ptid_get_pid (inferior_ptid),
|
||
ptid_get_pid (inferior_ptid),
|
||
0),
|
||
note_data, note_size);
|
||
return note_data;
|
||
}
|
||
|
||
/* 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;
|
||
char fname[16] = { '\0' };
|
||
char psargs[80] = { '\0' };
|
||
char *note_data = NULL;
|
||
ptid_t current_ptid = inferior_ptid;
|
||
char *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 ())
|
||
{
|
||
strncat (psargs, " ", sizeof (psargs) - strlen (psargs));
|
||
strncat (psargs, get_inferior_args (),
|
||
sizeof (psargs) - strlen (psargs));
|
||
}
|
||
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_auxv_read (¤t_target, &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")) > 0)
|
||
{
|
||
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")) > 0)
|
||
{
|
||
long long addr, endaddr, size, offset, inode;
|
||
char permissions[8], device[8], filename[MAXPATHLEN];
|
||
|
||
printf_filtered (_("Mapped address spaces:\n\n"));
|
||
if (TARGET_ADDR_BIT == 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 (TARGET_ADDR_BIT == 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")) > 0)
|
||
{
|
||
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")) > 0)
|
||
{
|
||
int itmp;
|
||
char ctmp;
|
||
|
||
if (fscanf (procfile, "%d ", &itmp) > 0)
|
||
printf_filtered (_("Process: %d\n"), itmp);
|
||
if (fscanf (procfile, "%s ", &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, "%u ", &itmp) > 0)
|
||
printf_filtered (_("Flags: 0x%x\n"), itmp);
|
||
if (fscanf (procfile, "%u ", &itmp) > 0)
|
||
printf_filtered (_("Minor faults (no memory page): %u\n"),
|
||
(unsigned int) itmp);
|
||
if (fscanf (procfile, "%u ", &itmp) > 0)
|
||
printf_filtered (_("Minor faults, children: %u\n"),
|
||
(unsigned int) itmp);
|
||
if (fscanf (procfile, "%u ", &itmp) > 0)
|
||
printf_filtered (_("Major faults (memory page faults): %u\n"),
|
||
(unsigned int) itmp);
|
||
if (fscanf (procfile, "%u ", &itmp) > 0)
|
||
printf_filtered (_("Major faults, children: %u\n"),
|
||
(unsigned int) itmp);
|
||
if (fscanf (procfile, "%d ", &itmp) > 0)
|
||
printf_filtered ("utime: %d\n", itmp);
|
||
if (fscanf (procfile, "%d ", &itmp) > 0)
|
||
printf_filtered ("stime: %d\n", itmp);
|
||
if (fscanf (procfile, "%d ", &itmp) > 0)
|
||
printf_filtered ("utime, children: %d\n", itmp);
|
||
if (fscanf (procfile, "%d ", &itmp) > 0)
|
||
printf_filtered ("stime, children: %d\n", itmp);
|
||
if (fscanf (procfile, "%d ", &itmp) > 0)
|
||
printf_filtered (_("jiffies remaining in current time slice: %d\n"),
|
||
itmp);
|
||
if (fscanf (procfile, "%d ", &itmp) > 0)
|
||
printf_filtered ("'nice' value: %d\n", itmp);
|
||
if (fscanf (procfile, "%u ", &itmp) > 0)
|
||
printf_filtered (_("jiffies until next timeout: %u\n"),
|
||
(unsigned int) itmp);
|
||
if (fscanf (procfile, "%u ", &itmp) > 0)
|
||
printf_filtered ("jiffies until next SIGALRM: %u\n",
|
||
(unsigned int) itmp);
|
||
if (fscanf (procfile, "%d ", &itmp) > 0)
|
||
printf_filtered (_("start time (jiffies since system boot): %d\n"),
|
||
itmp);
|
||
if (fscanf (procfile, "%u ", &itmp) > 0)
|
||
printf_filtered (_("Virtual memory size: %u\n"),
|
||
(unsigned int) itmp);
|
||
if (fscanf (procfile, "%u ", &itmp) > 0)
|
||
printf_filtered (_("Resident set size: %u\n"), (unsigned int) itmp);
|
||
if (fscanf (procfile, "%u ", &itmp) > 0)
|
||
printf_filtered ("rlim: %u\n", (unsigned int) itmp);
|
||
if (fscanf (procfile, "%u ", &itmp) > 0)
|
||
printf_filtered (_("Start of text: 0x%x\n"), itmp);
|
||
if (fscanf (procfile, "%u ", &itmp) > 0)
|
||
printf_filtered (_("End of text: 0x%x\n"), itmp);
|
||
if (fscanf (procfile, "%u ", &itmp) > 0)
|
||
printf_filtered (_("Start of stack: 0x%x\n"), itmp);
|
||
#if 0 /* Don't know how architecture-dependent the rest is...
|
||
Anyway the signal bitmap info is available from "status". */
|
||
if (fscanf (procfile, "%u ", &itmp) > 0) /* FIXME arch? */
|
||
printf_filtered (_("Kernel stack pointer: 0x%x\n"), itmp);
|
||
if (fscanf (procfile, "%u ", &itmp) > 0) /* FIXME arch? */
|
||
printf_filtered (_("Kernel instr pointer: 0x%x\n"), itmp);
|
||
if (fscanf (procfile, "%d ", &itmp) > 0)
|
||
printf_filtered (_("Pending signals bitmap: 0x%x\n"), itmp);
|
||
if (fscanf (procfile, "%d ", &itmp) > 0)
|
||
printf_filtered (_("Blocked signals bitmap: 0x%x\n"), itmp);
|
||
if (fscanf (procfile, "%d ", &itmp) > 0)
|
||
printf_filtered (_("Ignored signals bitmap: 0x%x\n"), itmp);
|
||
if (fscanf (procfile, "%d ", &itmp) > 0)
|
||
printf_filtered (_("Catched signals bitmap: 0x%x\n"), itmp);
|
||
if (fscanf (procfile, "%u ", &itmp) > 0) /* FIXME arch? */
|
||
printf_filtered (_("wchan (system call): 0x%x\n"), itmp);
|
||
#endif
|
||
fclose (procfile);
|
||
}
|
||
else
|
||
warning (_("unable to open /proc file '%s'"), fname1);
|
||
}
|
||
}
|
||
|
||
int
|
||
linux_proc_xfer_memory (CORE_ADDR addr, char *myaddr, int len, int write,
|
||
struct mem_attrib *attrib, struct target_ops *target)
|
||
{
|
||
int fd, ret;
|
||
char filename[64];
|
||
|
||
if (write)
|
||
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, myaddr, len, addr) != len)
|
||
#else
|
||
if (lseek (fd, addr, SEEK_SET) == -1 || read (fd, myaddr, 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);
|
||
}
|
||
|
||
void
|
||
_initialize_linux_nat (void)
|
||
{
|
||
struct sigaction action;
|
||
extern void thread_db_init (struct target_ops *);
|
||
|
||
deprecated_child_ops.to_find_memory_regions = linux_nat_find_memory_regions;
|
||
deprecated_child_ops.to_make_corefile_notes = linux_nat_make_corefile_notes;
|
||
|
||
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."));
|
||
|
||
init_linux_nat_ops ();
|
||
add_target (&linux_nat_ops);
|
||
thread_db_init (&linux_nat_ops);
|
||
|
||
/* Save the original signal mask. */
|
||
sigprocmask (SIG_SETMASK, NULL, &normal_mask);
|
||
|
||
action.sa_handler = sigchld_handler;
|
||
sigemptyset (&action.sa_mask);
|
||
action.sa_flags = SA_RESTART;
|
||
sigaction (SIGCHLD, &action, NULL);
|
||
|
||
/* Make sure we don't block SIGCHLD during a sigsuspend. */
|
||
sigprocmask (SIG_SETMASK, NULL, &suspend_mask);
|
||
sigdelset (&suspend_mask, SIGCHLD);
|
||
|
||
sigemptyset (&blocked_mask);
|
||
|
||
add_setshow_zinteger_cmd ("lin-lwp", no_class, &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);
|
||
}
|
||
|
||
|
||
/* 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), (char *) &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;
|
||
|
||
sigemptyset (set);
|
||
|
||
restart = get_signo ("__pthread_sig_restart");
|
||
if (restart == 0)
|
||
return;
|
||
|
||
cancel = get_signo ("__pthread_sig_cancel");
|
||
if (cancel == 0)
|
||
return;
|
||
|
||
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);
|
||
}
|