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authorJaccon Bastiaansen <jaccon.bastiaansen@gmail.com>2013-05-13 17:28:27 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2013-05-13 23:42:24 +0100
commit6eabb3301b1facee669d9938f7c5a0295c21d71d (patch)
tree4bd6c1782d956367ac1bf20286cfc36e10abc428 /arch/arm
parent9e01573b5cf8b3188c1f33493d2e73a30e8d25fc (diff)
downloadop-kernel-dev-6eabb3301b1facee669d9938f7c5a0295c21d71d.zip
op-kernel-dev-6eabb3301b1facee669d9938f7c5a0295c21d71d.tar.gz
ARM: 7720/1: ARM v6/v7 cmpxchg64 shouldn't clear upper 32 bits of the old/new value
The implementation of cmpxchg64() for the ARM v6 and v7 architecture casts parameter 2 and 3 (the old and new 64bit values) to an unsigned long before calling the atomic_cmpxchg64() function. This clears the top 32 bits of the old and new values, resulting in the wrong values being compare-exchanged. Luckily, this only appears to be used for 64-bit sched_clock, which we don't (yet) have on ARM. This bug was introduced by commit 3e0f5a15f500 ("ARM: 7404/1: cmpxchg64: use atomic64 and local64 routines for cmpxchg64"). Cc: <stable@vger.kernel.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Jaccon Bastiaansen <jaccon.bastiaansen@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/include/asm/cmpxchg.h8
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/arm/include/asm/cmpxchg.h b/arch/arm/include/asm/cmpxchg.h
index 7eb18c1..4f009c1 100644
--- a/arch/arm/include/asm/cmpxchg.h
+++ b/arch/arm/include/asm/cmpxchg.h
@@ -233,15 +233,15 @@ static inline unsigned long __cmpxchg_local(volatile void *ptr,
((__typeof__(*(ptr)))atomic64_cmpxchg(container_of((ptr), \
atomic64_t, \
counter), \
- (unsigned long)(o), \
- (unsigned long)(n)))
+ (unsigned long long)(o), \
+ (unsigned long long)(n)))
#define cmpxchg64_local(ptr, o, n) \
((__typeof__(*(ptr)))local64_cmpxchg(container_of((ptr), \
local64_t, \
a), \
- (unsigned long)(o), \
- (unsigned long)(n)))
+ (unsigned long long)(o), \
+ (unsigned long long)(n)))
#endif /* __LINUX_ARM_ARCH__ >= 6 */
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