[PATCH 4.9 102/206] x86/prctl/uapi: Remove #ifdef for CHECKPOINT_RESTORE

From: Greg Kroah-Hartman
Date: Tue Jan 10 2017 - 08:48:24 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Dmitry Safonov <dsafonov@xxxxxxxxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: Dmitry Safonov <dsafonov@xxxxxxxxxxxxx>
Acked-by: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: 0x7f454c46@xxxxxxxxx
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: oleg@xxxxxxxxxx
Fixes: 2eefd8789698 ("x86/arch_prctl/vdso: Add ARCH_MAP_VDSO_*")
Link: http://lkml.kernel.org/r/20161027141516.28447-2-dsafonov@xxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
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 */