From 522d7decc0370070448a8c28982c8dfd8970489e Mon Sep 17 00:00:00 2001 From: Michel Lespinasse Date: Thu, 10 Mar 2011 18:47:31 -0800 Subject: [PATCH] futex: Remove redundant pagefault_disable in futex_atomic_cmpxchg_inatomic() kernel/futex.c disables page faults before calling futex_atomic_cmpxchg_inatomic(), so there is no need to do it again within that function. Signed-off-by: Michel Lespinasse Cc: Darren Hart Cc: Peter Zijlstra Cc: Matt Turner Cc: Russell King Cc: David Howells Cc: Tony Luck Cc: Michal Simek Cc: Ralf Baechle Cc: "James E.J. Bottomley" Cc: Benjamin Herrenschmidt Cc: Martin Schwidefsky Cc: Paul Mundt Cc: "David S. Miller" Cc: Chris Metcalf Cc: Linus Torvalds LKML-Reference: <20110311024731.GB26122@google.com> Signed-off-by: Thomas Gleixner --- arch/arm/include/asm/futex.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/arm/include/asm/futex.h b/arch/arm/include/asm/futex.h index b33fe7065b38..7133a8620830 100644 --- a/arch/arm/include/asm/futex.h +++ b/arch/arm/include/asm/futex.h @@ -95,7 +95,8 @@ futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) return -EFAULT; - pagefault_disable(); /* implies preempt_disable() */ + /* Note that preemption is disabled by futex_atomic_cmpxchg_inatomic + * call sites. */ __asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n" "1: " T(ldr) " %0, [%3]\n" @@ -115,8 +116,6 @@ futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) : "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT) : "cc", "memory"); - pagefault_enable(); /* subsumes preempt_enable() */ - return val; } -- 2.39.2