2005-12-13 Ulrich Drepper <drepper@redhat.com>

1 files changed, 140 insertions, 0 deletions

diff --git a/stdlib/abort.c b/stdlib/abort.c
new file mode 100644
index 0000000..00788f2
--- /dev/null
+++ b/stdlib/abort.c
@@ -0,0 +1,140 @@
+/* Copyright (C) 1991,93,95,96,97,98,2001,02 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <bits/libc-lock.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+/* Try to get a machine dependent instruction which will make the
+   program crash.  This is used in case everything else fails.  */
+#include <abort-instr.h>
+#ifndef ABORT_INSTRUCTION
+/* No such instruction is available.  */
+# define ABORT_INSTRUCTION
+#endif
+
+#ifdef USE_IN_LIBIO
+# include <libio/libioP.h>
+# define fflush(s) _IO_flush_all_lockp (0)
+#endif
+
+/* We must avoid to run in circles.  Therefore we remember how far we
+   already got.  */
+static int stage;
+
+/* We should be prepared for multiple threads trying to run abort.  */
+__libc_lock_define_initialized_recursive (static, lock);
+
+
+/* Cause an abnormal program termination with core-dump.  */
+void
+abort (void)
+{
+  struct sigaction act;
+  sigset_t sigs;
+
+  /* First acquire the lock.  */
+  __libc_lock_lock_recursive (lock);
+
+  /* Now it's for sure we are alone.  But recursive calls are possible.  */
+
+  /* Unlock SIGABRT.  */
+  if (stage == 0)
+    {
+      ++stage;
+      if (__sigemptyset (&sigs) == 0 &&
+	  __sigaddset (&sigs, SIGABRT) == 0)
+	__sigprocmask (SIG_UNBLOCK, &sigs, (sigset_t *) NULL);
+    }
+
+  /* Flush all streams.  We cannot close them now because the user
+     might have registered a handler for SIGABRT.  */
+  if (stage == 1)
+    {
+      ++stage;
+      fflush (NULL);
+    }
+
+  /* Send signal which possibly calls a user handler.  */
+  if (stage == 2)
+    {
+      /* This stage is special: we must allow repeated calls of
+	 `abort' when a user defined handler for SIGABRT is installed.
+	 This is risky since the `raise' implementation might also
+	 fail but I don't see another possibility.  */
+      int save_stage = stage;
+
+      stage = 0;
+      __libc_lock_unlock_recursive (lock);
+
+      raise (SIGABRT);
+
+      __libc_lock_lock_recursive (lock);
+      stage = save_stage + 1;
+    }
+
+  /* There was a handler installed.  Now remove it.  */
+  if (stage == 3)
+    {
+      ++stage;
+      memset (&act, '\0', sizeof (struct sigaction));
+      act.sa_handler = SIG_DFL;
+      __sigfillset (&act.sa_mask);
+      act.sa_flags = 0;
+      __sigaction (SIGABRT, &act, NULL);
+    }
+
+  /* Now close the streams which also flushes the output the user
+     defined handler might has produced.  */
+  if (stage == 4)
+    {
+      ++stage;
+      __fcloseall ();
+    }
+
+  /* Try again.  */
+  if (stage == 5)
+    {
+      ++stage;
+      raise (SIGABRT);
+    }
+
+  /* Now try to abort using the system specific command.  */
+  if (stage == 6)
+    {
+      ++stage;
+      ABORT_INSTRUCTION;
+    }
+
+  /* If we can't signal ourselves and the abort instruction failed, exit.  */
+  if (stage == 7)
+    {
+      ++stage;
+      _exit (127);
+    }
+
+  /* If even this fails try to use the provided instruction to crash
+     or otherwise make sure we never return.  */
+  while (1)
+    /* Try for ever and ever.  */
+    ABORT_INSTRUCTION;
+}
+libc_hidden_def (abort)