From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20130603221155.158605909@goodmis.org> Date: Mon, 03 Jun 2013 18:10:34 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Will Deacon , Jaccon Bastiaansen , Russell King Subject: [18/65] ARM: 7720/1: ARM v6/v7 cmpxchg64 shouldnt clear upper 32 bits of the old/new value References: <20130603221016.243553628@goodmis.org> Content-Disposition: inline; filename=0018-ARM-7720-1-ARM-v6-v7-cmpxchg64-shouldn-t-clear-upper.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.6.11.5 stable review patch. If anyone has any objections, please let me know. ------------------ From: Jaccon Bastiaansen [ Upstream commit 6eabb3301b1facee669d9938f7c5a0295c21d71d ] 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: Acked-by: Will Deacon Signed-off-by: Jaccon Bastiaansen Signed-off-by: Russell King Signed-off-by: Steven Rostedt --- arch/arm/include/asm/cmpxchg.h | 8 ++++---- 1 file 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 */ -- 1.7.10.4