Patch "arm64: armv8_deprecated: ensure extension of addr" has been added to the 4.9-stable tree

Patch "arm64: armv8_deprecated: ensure extension of addr" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    arm64: armv8_deprecated: ensure extension of addr

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     arm64-armv8_deprecated-ensure-extension-of-addr.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 55de49f9aa17b0b2b144dd2af587177b9aadf429 Mon Sep 17 00:00:00 2001
From: Mark Rutland <mark.rutland@arm.com>
Date: Wed, 3 May 2017 16:09:36 +0100
Subject: arm64: armv8_deprecated: ensure extension of addr

From: Mark Rutland <mark.rutland@arm.com>

commit 55de49f9aa17b0b2b144dd2af587177b9aadf429 upstream.

Our compat swp emulation holds the compat user address in an unsigned
int, which it passes to __user_swpX_asm(). When a 32-bit value is passed
in a register, the upper 32 bits of the register are unknown, and we
must extend the value to 64 bits before we can use it as a base address.

This patch casts the address to unsigned long to ensure it has been
suitably extended, avoiding the potential issue, and silencing a related
warning from clang.

Fixes: bd35a4adc413 ("arm64: Port SWP/SWPB emulation support from arm")
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/arm64/kernel/armv8_deprecated.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/arch/arm64/kernel/armv8_deprecated.c
+++ b/arch/arm64/kernel/armv8_deprecated.c
@@ -309,7 +309,8 @@ static void __init register_insn_emulati
 	ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN,	\
 		CONFIG_ARM64_PAN)				\
 	: "=&r" (res), "+r" (data), "=&r" (temp), "=&r" (temp2)	\
-	: "r" (addr), "i" (-EAGAIN), "i" (-EFAULT),		\
+	: "r" ((unsigned long)addr), "i" (-EAGAIN),		\
+	  "i" (-EFAULT),					\
 	  "i" (__SWP_LL_SC_LOOPS)				\
 	: "memory")
 


Patches currently in stable-queue which might be from mark.rutland@arm.com are

queue-4.9/arm64-armv8_deprecated-ensure-extension-of-addr.patch
queue-4.9/arm64-uaccess-ensure-extension-of-access_ok-addr.patch
queue-4.9/arm64-xchg-hazard-against-entire-exchange-variable.patch
queue-4.9/arm64-ensure-extension-of-smp_store_release-value.patch