[3.13.y.z extended stable] Patch "xattr: guard against simultaneous glibc header inclusion" has been added to staging queue

Kamal Mostafa kamal at canonical.com
Thu May 1 19:17:37 UTC 2014

This is a note to let you know that I have just added a patch titled

    xattr: guard against simultaneous glibc header inclusion

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:


This patch is scheduled to be released in version

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see



>From da732f456e9d191f1b0a1645482d2f093f3c01b5 Mon Sep 17 00:00:00 2001
From: Serge Hallyn <serge.hallyn at ubuntu.com>
Date: Thu, 3 Apr 2014 14:48:33 -0700
Subject: xattr: guard against simultaneous glibc header inclusion

commit ea1a8217b06b41b31a2b60b0b83f75c77ef9c873 upstream.

If the glibc xattr.h header is included after the uapi header,
compilation fails due to an enum re-using a #define from the uapi

Protect against this by guarding the define and enum inclusions against
each other.

(See https://lists.debian.org/debian-glibc/2014/03/msg00029.html
and https://sourceware.org/glibc/wiki/Synchronizing_Headers
for more information.)

Signed-off-by: Serge Hallyn <serge.hallyn at ubuntu.com>
Cc: Andrew Morton <akpm at linux-foundation.org>
Cc: Allan McRae <allan at archlinux.org>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
 include/uapi/linux/libc-compat.h | 9 +++++++++
 include/uapi/linux/xattr.h       | 7 +++++++
 2 files changed, 16 insertions(+)

diff --git a/include/uapi/linux/libc-compat.h b/include/uapi/linux/libc-compat.h
index 335e8a7..c140620 100644
--- a/include/uapi/linux/libc-compat.h
+++ b/include/uapi/linux/libc-compat.h
@@ -85,6 +85,12 @@

 #endif /* _NETINET_IN_H */

+/* Definitions for xattr.h */
+#if defined(_SYS_XATTR_H)
+#define __UAPI_DEF_XATTR		0
+#define __UAPI_DEF_XATTR		1

 /* If we did not see any headers from any supported C libraries,
  * or we are being included in the kernel, then define everything
@@ -98,6 +104,9 @@
 #define __UAPI_DEF_IPV6_MREQ		1
 #define __UAPI_DEF_IPPROTO_V6		1

+/* Definitions for xattr.h */
+#define __UAPI_DEF_XATTR		1
 #endif /* __GLIBC__ */

 #endif /* _UAPI_LIBC_COMPAT_H */
diff --git a/include/uapi/linux/xattr.h b/include/uapi/linux/xattr.h
index e4629b9..a63c146 100644
--- a/include/uapi/linux/xattr.h
+++ b/include/uapi/linux/xattr.h
@@ -7,11 +7,18 @@
   Copyright (c) 2001-2002 Silicon Graphics, Inc.  All Rights Reserved.
   Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris at redhat.com>
+#include <linux/libc-compat.h>

+#ifdef __UAPI_DEF_XATTR
 #define XATTR_CREATE	0x1	/* set value, fail if attr already exists */
 #define XATTR_REPLACE	0x2	/* set value, fail if attr does not exist */

 /* Namespaces */
 #define XATTR_OS2_PREFIX "os2."

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