[PATCH 4.9 60/77] x86/speculation: Fix up array_index_nospec_mask() asm constraint
From: Greg Kroah-Hartman
Date: Wed Feb 21 2018 - 09:29:46 EST
4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Dan Williams <dan.j.williams@xxxxxxxxx>
commit be3233fbfcb8f5acb6e3bcd0895c3ef9e100d470 upstream.
Allow the compiler to handle @size as an immediate value or memory
directly rather than allocating a register.
Reported-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/151797010204.1289.1510000292250184993.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/barrier.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/include/asm/barrier.h
+++ b/arch/x86/include/asm/barrier.h
@@ -39,7 +39,7 @@ static inline unsigned long array_index_
asm ("cmp %1,%2; sbb %0,%0;"
:"=r" (mask)
- :"r"(size),"r" (index)
+ :"g"(size),"r" (index)
:"cc");
return mask;
}