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/* Copyright (C) 2016-2019 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 3 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, see <http://www.gnu.org/licenses/>. */
#include "common/common-defs.h"
#include "common/signals-state-save-restore.h"
/* Standard C includes. */
#include <signal.h>
/* The original signal actions and mask. */
#ifdef HAVE_SIGACTION
static struct sigaction original_signal_actions[NSIG];
/* Note that we use sigprocmask without worrying about threads because
the save/restore functions are called either from main, or after a
fork. In both cases, we know the calling process is single
threaded. */
static sigset_t original_signal_mask;
#endif
/* See signals-state-save-restore.h. */
void
save_original_signals_state (bool quiet)
{
#ifdef HAVE_SIGACTION
int i;
int res;
res = sigprocmask (0, NULL, &original_signal_mask);
if (res == -1)
perror_with_name (("sigprocmask"));
bool found_preinstalled = false;
for (i = 1; i < NSIG; i++)
{
struct sigaction *oldact = &original_signal_actions[i];
res = sigaction (i, NULL, oldact);
if (res == -1 && errno == EINVAL)
{
/* Some signal numbers in the range are invalid. */
continue;
}
else if (res == -1)
perror_with_name (("sigaction"));
/* If we find a custom signal handler already installed, then
this function was called too late. This is a warning instead
of an internal error because this can also happen if you
LD_PRELOAD a library that installs a signal handler early via
__attribute__((constructor)), like libSegFault.so. */
if (!quiet
&& oldact->sa_handler != SIG_DFL
&& oldact->sa_handler != SIG_IGN)
{
found_preinstalled = true;
/* Use raw fprintf here because we're being called in early
startup, before GDB's filtered streams are created. */
fprintf (stderr,
_("warning: Found custom handler for signal "
"%d (%s) preinstalled.\n"), i,
strsignal (i));
}
}
if (found_preinstalled)
{
fprintf (stderr, _("\
Some signal dispositions inherited from the environment (SIG_DFL/SIG_IGN)\n\
won't be propagated to spawned programs.\n"));
}
#endif
}
/* See signals-state-save-restore.h. */
void
restore_original_signals_state (void)
{
#ifdef HAVE_SIGACTION
int i;
int res;
for (i = 1; i < NSIG; i++)
{
res = sigaction (i, &original_signal_actions[i], NULL);
if (res == -1 && errno == EINVAL)
{
/* Some signal numbers in the range are invalid. */
continue;
}
else if (res == -1)
perror_with_name (("sigaction"));
}
res = sigprocmask (SIG_SETMASK, &original_signal_mask, NULL);
if (res == -1)
perror_with_name (("sigprocmask"));
#endif
}
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