summaryrefslogtreecommitdiff
path: root/arch/arm/lib/putuser.S
diff options
context:
space:
mode:
authorRussell King <rmk+kernel@arm.linux.org.uk>2012-09-07 18:22:28 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2012-09-09 17:28:47 +0100
commit8404663f81d212918ff85f493649a7991209fa04 (patch)
treeb695686fd2764914da245ef31649b1deb91ddafa /arch/arm/lib/putuser.S
parent2b2040af0b64cd93e5d4df2494c4486cf604090d (diff)
ARM: 7527/1: uaccess: explicitly check __user pointer when !CPU_USE_DOMAINS
The {get,put}_user macros don't perform range checking on the provided __user address when !CPU_HAS_DOMAINS. This patch reworks the out-of-line assembly accessors to check the user address against a specified limit, returning -EFAULT if is is out of range. [will: changed get_user register allocation to match put_user] [rmk: fixed building on older ARM architectures] Reported-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: stable@vger.kernel.org Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/lib/putuser.S')
-rw-r--r--arch/arm/lib/putuser.S6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm/lib/putuser.S b/arch/arm/lib/putuser.S
index 7db25990c589..3d73dcb959b0 100644
--- a/arch/arm/lib/putuser.S
+++ b/arch/arm/lib/putuser.S
@@ -16,6 +16,7 @@
* __put_user_X
*
* Inputs: r0 contains the address
+ * r1 contains the address limit, which must be preserved
* r2, r3 contains the value
* Outputs: r0 is the error code
* lr corrupted
@@ -27,16 +28,19 @@
* Note also that it is intended that __put_user_bad is not global.
*/
#include <linux/linkage.h>
+#include <asm/assembler.h>
#include <asm/errno.h>
#include <asm/domain.h>
ENTRY(__put_user_1)
+ check_uaccess r0, 1, r1, ip, __put_user_bad
1: TUSER(strb) r2, [r0]
mov r0, #0
mov pc, lr
ENDPROC(__put_user_1)
ENTRY(__put_user_2)
+ check_uaccess r0, 2, r1, ip, __put_user_bad
mov ip, r2, lsr #8
#ifdef CONFIG_THUMB2_KERNEL
#ifndef __ARMEB__
@@ -60,12 +64,14 @@ ENTRY(__put_user_2)
ENDPROC(__put_user_2)
ENTRY(__put_user_4)
+ check_uaccess r0, 4, r1, ip, __put_user_bad
4: TUSER(str) r2, [r0]
mov r0, #0
mov pc, lr
ENDPROC(__put_user_4)
ENTRY(__put_user_8)
+ check_uaccess r0, 8, r1, ip, __put_user_bad
#ifdef CONFIG_THUMB2_KERNEL
5: TUSER(str) r2, [r0]
6: TUSER(str) r3, [r0, #4]