From: Ulrich Drepper <drepper@redhat.com>
Date: Mon, 6 Oct 2008 16:47:10 +0000 (+0000)
Subject: * sysdeps/unix/sysv/linux/fork.c (__libc_fork): Add memory barrier
X-Git-Tag: cvs/fedora-glibc-20081019T1815~9
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=af62b44029c208376086940976cc386c9921f086;p=thirdparty%2Fglibc.git

* sysdeps/unix/sysv/linux/fork.c (__libc_fork): Add memory barrier

	to force runp->refcntr to be read from memory.
---

diff --git a/ChangeLog b/ChangeLog
index 9dd19f1575c..8a37b4a0fa9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2008-09-11  Martin Schwidefsky  <schwidefsky@de.ibm.com>
+
+	* sysdeps/unix/sysv/linux/fork.c (__libc_fork): Add memory barrier
+	to force runp->refcntr to be read from memory.
+
 2008-09-18  Andreas Schwab  <schwab@suse.de>
 
 	[BZ #6942]
diff --git a/nptl/sysdeps/unix/sysv/linux/fork.c b/nptl/sysdeps/unix/sysv/linux/fork.c
index 1683de80fdf..524d72c5874 100644
--- a/nptl/sysdeps/unix/sysv/linux/fork.c
+++ b/nptl/sysdeps/unix/sysv/linux/fork.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2002, 2003, 2007 Free Software Foundation, Inc.
+/* Copyright (C) 2002, 2003, 2007, 2008 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
 
@@ -64,6 +64,9 @@ __libc_fork (void)
   struct fork_handler *runp;
   while ((runp = __fork_handlers) != NULL)
     {
+      /* Make sure we read from the current RUNP pointer.  */
+      atomic_full_barrier ();
+
       unsigned int oldval = runp->refcntr;
 
       if (oldval == 0)