Patch "x86/prctl/uapi: Remove #ifdef for CHECKPOINT_RESTORE" has been added to the 4.9-stable tree

Patch "x86/prctl/uapi: Remove #ifdef for CHECKPOINT_RESTORE" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    x86/prctl/uapi: Remove #ifdef for CHECKPOINT_RESTORE

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     x86-prctl-uapi-remove-ifdef-for-checkpoint_restore.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From a01aa6c9f40fe03c82032e7f8b3bcf1e6c93ac0e Mon Sep 17 00:00:00 2001
From: Dmitry Safonov <dsafonov@virtuozzo.com>
Date: Thu, 27 Oct 2016 17:15:15 +0300
Subject: x86/prctl/uapi: Remove #ifdef for CHECKPOINT_RESTORE

From: Dmitry Safonov <dsafonov@virtuozzo.com>

commit a01aa6c9f40fe03c82032e7f8b3bcf1e6c93ac0e upstream.

As userspace knows nothing about kernel config, thus #ifdefs
around ABI prctl constants makes them invisible to userspace.

Let it be clean'n'simple: remove #ifdefs.

If kernel has CONFIG_CHECKPOINT_RESTORE disabled, sys_prctl()
will return -EINVAL for those prctls.

Reported-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: 0x7f454c46@gmail.com
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Cc: oleg@redhat.com
Fixes: 2eefd8789698 ("x86/arch_prctl/vdso: Add ARCH_MAP_VDSO_*")
Link: http://lkml.kernel.org/r/20161027141516.28447-2-dsafonov@virtuozzo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/include/uapi/asm/prctl.h |    8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

--- a/arch/x86/include/uapi/asm/prctl.h
+++ b/arch/x86/include/uapi/asm/prctl.h
@@ -6,10 +6,8 @@
 #define ARCH_GET_FS 0x1003
 #define ARCH_GET_GS 0x1004
 
-#ifdef CONFIG_CHECKPOINT_RESTORE
-# define ARCH_MAP_VDSO_X32	0x2001
-# define ARCH_MAP_VDSO_32	0x2002
-# define ARCH_MAP_VDSO_64	0x2003
-#endif
+#define ARCH_MAP_VDSO_X32	0x2001
+#define ARCH_MAP_VDSO_32	0x2002
+#define ARCH_MAP_VDSO_64	0x2003
 
 #endif /* _ASM_X86_PRCTL_H */


Patches currently in stable-queue which might be from dsafonov@virtuozzo.com are

queue-4.9/x86-prctl-uapi-remove-ifdef-for-checkpoint_restore.patch