/* Emergency actions in case of a fatal signal.
- Copyright (C) 2003-2004, 2006-2007 Free Software Foundation, Inc.
+ Copyright (C) 2003-2004, 2006-2008 Free Software Foundation, Inc.
Written by Bruno Haible <bruno@clisp.org>, 2003.
- This program is free software; you can redistribute it and/or modify
+ 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, or (at your option)
- any later version.
+ 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
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include <config.h>
#include <signal.h>
#include <unistd.h>
+#include "sig-handler.h"
#include "xalloc.h"
#define SIZEOF(a) (sizeof(a) / sizeof(a[0]))
-
/* ========================================================================= */
static bool fatal_signals_initialized = false;
if (!fatal_signals_initialized)
{
-#if HAVE_SIGACTION
size_t i;
for (i = 0; i < num_fatal_signals; i++)
struct sigaction action;
if (sigaction (fatal_signals[i], NULL, &action) >= 0
- && action.sa_handler == SIG_IGN)
+ && get_handler (&action) == SIG_IGN)
fatal_signals[i] = -1;
}
-#endif
fatal_signals_initialized = true;
}
static size_t actions_allocated = SIZEOF (static_actions);
+/* The saved signal handlers.
+ Size 32 would not be sufficient: On HP-UX, SIGXCPU = 33, SIGXFSZ = 34. */
+static struct sigaction saved_sigactions[64];
+
+
/* Uninstall the handlers. */
static inline void
uninstall_handlers ()
for (i = 0; i < num_fatal_signals; i++)
if (fatal_signals[i] >= 0)
- signal (fatal_signals[i], SIG_DFL);
+ {
+ int sig = fatal_signals[i];
+ if (saved_sigactions[sig].sa_handler == SIG_IGN)
+ saved_sigactions[sig].sa_handler = SIG_DFL;
+ sigaction (sig, &saved_sigactions[sig], NULL);
+ }
}
}
/* Now execute the signal's default action.
- If signal() blocks the signal being delivered for the duration of the
- signal handler's execution, the re-raised signal is delivered when this
- handler returns; otherwise it is delivered already during raise(). */
+ If the signal being delivered was blocked, the re-raised signal would be
+ delivered when this handler returns. But the way we install this handler,
+ no signal is blocked, and the re-raised signal is delivered already
+ during raise(). */
uninstall_handlers ();
-#if HAVE_RAISE
raise (sig);
-#else
- kill (getpid (), sig);
-#endif
}
install_handlers ()
{
size_t i;
-
+ struct sigaction action;
+
+ action.sa_handler = &fatal_signal_handler;
+ /* If we get a fatal signal while executing fatal_signal_handler, enter
+ fatal_signal_handler recursively, since it is reentrant. Hence no
+ SA_RESETHAND. */
+ action.sa_flags = SA_NODEFER;
+ sigemptyset (&action.sa_mask);
for (i = 0; i < num_fatal_signals; i++)
if (fatal_signals[i] >= 0)
- signal (fatal_signals[i], &fatal_signal_handler);
+ {
+ int sig = fatal_signals[i];
+
+ if (!(sig < sizeof (saved_sigactions) / sizeof (saved_sigactions[0])))
+ abort ();
+ sigaction (sig, &action, &saved_sigactions[sig]);
+ }
}