X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Ffatal-signal.c;h=64b346d8747b4637bcc684bc74a706ad8445e2e6;hb=b6d87f536521a59758453d8dbd071e7cd6efc39d;hp=c726a0cb5f7545acd342f0e555dbd7ebe8b03ac3;hpb=a29af463676f147bba1a8cad38627d4e03f4e009;p=gnulib.git

diff --git a/lib/fatal-signal.c b/lib/fatal-signal.c
index c726a0cb5..64b346d87 100644
--- a/lib/fatal-signal.c
+++ b/lib/fatal-signal.c
@@ -1,11 +1,11 @@
 /* Emergency actions in case of a fatal signal.
-   Copyright (C) 2003-2004 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
@@ -13,13 +13,10 @@
    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.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 
-#ifdef HAVE_CONFIG_H
-# include "config.h"
-#endif
+#include <config.h>
 
 /* Specification.  */
 #include "fatal-signal.h"
@@ -27,16 +24,13 @@
 #include <stdbool.h>
 #include <stdlib.h>
 #include <signal.h>
-#include <string.h>
-#if HAVE_UNISTD_H
-# include <unistd.h>
-#endif
+#include <unistd.h>
 
+#include "sig-handler.h"
 #include "xalloc.h"
 
 #define SIZEOF(a) (sizeof(a) / sizeof(a[0]))
 
-
 /* ========================================================================= */
 
 
@@ -77,6 +71,10 @@ static int fatal_signals[] =
 #ifdef SIGXFSZ
     SIGXFSZ,
 #endif
+    /* Woe32 signals.  */
+#ifdef SIGBREAK
+    SIGBREAK,
+#endif
     0
   };
 
@@ -90,7 +88,6 @@ init_fatal_signals (void)
   static bool fatal_signals_initialized = false;
   if (!fatal_signals_initialized)
     {
-#if HAVE_SIGACTION
       size_t i;
 
       for (i = 0; i < num_fatal_signals; i++)
@@ -98,10 +95,9 @@ init_fatal_signals (void)
 	  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;
     }
@@ -134,10 +130,14 @@ static inline void
 uninstall_handlers ()
 {
   size_t i;
+  struct sigaction action;
 
+  action.sa_handler = SIG_DFL;
+  action.sa_flags = 0;
+  sigemptyset (&action.sa_mask);
   for (i = 0; i < num_fatal_signals; i++)
     if (fatal_signals[i] >= 0)
-      signal (fatal_signals[i], SIG_DFL);
+      sigaction (fatal_signals[i], &action, NULL);
 }
 
 
@@ -160,15 +160,12 @@ fatal_signal_handler (int sig)
     }
 
   /* 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
 }
 
 
@@ -177,10 +174,17 @@ static inline void
 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);
+      sigaction (fatal_signals[i], &action, NULL);
 }
 
 
@@ -203,12 +207,17 @@ at_fatal_signal (action_t action)
 	 because then the cleanup() function could access an already
 	 deallocated array.  */
       actions_entry_t *old_actions = actions;
+      size_t old_actions_allocated = actions_allocated;
       size_t new_actions_allocated = 2 * actions_allocated;
       actions_entry_t *new_actions =
-	xmalloc (new_actions_allocated * sizeof (actions_entry_t));
-
-      memcpy (new_actions, old_actions,
-	      actions_allocated * sizeof (actions_entry_t));
+	XNMALLOC (new_actions_allocated, actions_entry_t);
+      size_t k;
+
+      /* Don't use memcpy() here, because memcpy takes non-volatile arguments
+	 and is therefore not guaranteed to complete all memory stores before
+	 the next statement.  */
+      for (k = 0; k < old_actions_allocated; k++)
+	new_actions[k] = old_actions[k];
       actions = new_actions;
       actions_allocated = new_actions_allocated;
       /* Now we can free the old actions array.  */
@@ -227,8 +236,6 @@ at_fatal_signal (action_t action)
 /* ========================================================================= */
 
 
-#if HAVE_POSIX_SIGNALBLOCKING
-
 static sigset_t fatal_signal_set;
 
 static void
@@ -265,20 +272,3 @@ unblock_fatal_signals ()
   init_fatal_signal_set ();
   sigprocmask (SIG_UNBLOCK, &fatal_signal_set, NULL);
 }
-
-#else
-
-/* Don't bother caring about the old systems which don't have POSIX signal
-   blocking.  */
-
-void
-block_fatal_signals ()
-{
-}
-
-void
-unblock_fatal_signals ()
-{
-}
-
-#endif