[PATCH] ARM: futex: fix clobbering oldval

From: mhban
Date: Wed Sep 21 2011 - 22:53:40 EST


This patch fixes clobbering oldval bug. oldval should be preserved for next
compare operation.

Change-Id: I2a63bc1bdb8de330eb9e1ac02d7da1f77e6e8c3c
Signed-off-by: Minho Ban <mhban@xxxxxxxxxxx>
---
arch/arm/include/asm/futex.h | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/arm/include/asm/futex.h b/arch/arm/include/asm/futex.h
index d2d733c..b0f2e8e 100644
--- a/arch/arm/include/asm/futex.h
+++ b/arch/arm/include/asm/futex.h
@@ -30,14 +30,14 @@
__asm__ __volatile__( \
"1: ldrex %1, [%2]\n" \
" " insn "\n" \
- "2: strex %1, %0, [%2]\n" \
- " teq %1, #0\n" \
+ "2: strex r5, %0, [%2]\n" \
+ " teq r5, #0\n" \
" bne 1b\n" \
" mov %0, #0\n" \
__futex_atomic_ex_table("%4") \
: "=&r" (ret), "=&r" (oldval) \
: "r" (uaddr), "r" (oparg), "Ir" (-EFAULT) \
- : "cc", "memory")
+ : "r5", "cc", "memory")

static inline int
futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
--
1.7.0.4


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