From mboxrd@z Thu Jan 1 00:00:00 1970 From: james.morse@arm.com (James Morse) Date: Tue, 2 Feb 2016 15:53:59 +0000 Subject: [PATCH] arm64: futex.h: Add missing PAN toggling Message-ID: <1454428439-10942-1-git-send-email-james.morse@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org futex.h's futex_atomic_cmpxchg_inatomic() does not use the __futex_atomic_op() macro and needs its own PAN toggling. This was missed when the feature was implemented. Fixes: 338d4f49d6f ("arm64: kernel: Add support for Privileged Access Never") Signed-off-by: James Morse --- arch/arm64/include/asm/futex.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm64/include/asm/futex.h b/arch/arm64/include/asm/futex.h index 007a69fc4f40..5f3ab8c1db55 100644 --- a/arch/arm64/include/asm/futex.h +++ b/arch/arm64/include/asm/futex.h @@ -121,6 +121,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, return -EFAULT; asm volatile("// futex_atomic_cmpxchg_inatomic\n" +ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN, CONFIG_ARM64_PAN) " prfm pstl1strm, %2\n" "1: ldxr %w1, %2\n" " sub %w3, %w1, %w4\n" @@ -137,6 +138,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, " .align 3\n" " .quad 1b, 4b, 2b, 4b\n" " .popsection\n" +ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN, CONFIG_ARM64_PAN) : "+r" (ret), "=&r" (val), "+Q" (*uaddr), "=&r" (tmp) : "r" (oldval), "r" (newval), "Ir" (-EFAULT) : "memory"); -- 2.6.2