Messages in this thread Patch in this message | | | Date | Thu, 10 Mar 2011 18:47:31 -0800 | From | Michel Lespinasse <> | Subject | [PATCH 1/3] futex: do not pagefault_disable in futex_atomic_cmpxchg_inatomic() |
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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 <walken@google.com>
diff --git a/arch/arm/include/asm/futex.h b/arch/arm/include/asm/futex.h index b33fe70..7133a86 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; } -- Michel "Walken" Lespinasse A program is never fully debugged until the last user dies.
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