path: root/arch/arm
diff options
authorRabin Vincent <rabin.vincent@stericsson.com>2012-07-04 07:37:37 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2012-07-05 12:57:16 +0100
commitf8b435bb918412c9410da4c4b0b02b6b3d99b27c (patch)
tree437a95d7a2b25659172cb4353b1511152e216a1c /arch/arm
parentfdeb8e35fd59e79dec385f98eb4b6d2e3398264b (diff)
ARM: 7440/1: kprobes: only test 'sub pc, pc, #1b-2b+8-2' on ARMv6
'sub pc, pc, #1b-2b+8-2' results in address<1:0> == '10'. sub pc, pc, #const (== ADR pc, #const) performs an interworking branch (BXWritePC()) on ARMv7+ and a simple branch (BranchWritePC()) on earlier versions. In ARM state, BXWritePC() is UNPREDICTABLE when address<1:0> == '10'. In ARM state on ARMv6+, BranchWritePC() ignores address<1:0>. Before ARMv6, BranchWritePC() is UNPREDICTABLE if address<1:0> != '00' So the instruction is UNPREDICTABLE both before and after v6. Acked-by: Jon Medhurst <tixy@yxit.co.uk> Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm')
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm/kernel/kprobes-test-arm.c b/arch/arm/kernel/kprobes-test-arm.c
index ba32b393b3f0..38c1a3b103a0 100644
--- a/arch/arm/kernel/kprobes-test-arm.c
+++ b/arch/arm/kernel/kprobes-test-arm.c
@@ -187,8 +187,8 @@ void kprobe_arm_test_cases(void)
TEST_BF_R ("mov pc, r",0,2f,"")
TEST_BF_RR("mov pc, r",0,2f,", asl r",1,0,"")
TEST_BB( "sub pc, pc, #1b-2b+8")
-#if __LINUX_ARM_ARCH__ >= 6
- TEST_BB( "sub pc, pc, #1b-2b+8-2") /* UNPREDICTABLE before ARMv6 */
+#if __LINUX_ARM_ARCH__ == 6 && !defined(CONFIG_CPU_V7)
+ TEST_BB( "sub pc, pc, #1b-2b+8-2") /* UNPREDICTABLE before and after ARMv6 */
TEST_BB_R( "sub pc, pc, r",14, 1f-2f+8,"")
TEST_BB_R( "rsb pc, r",14,1f-2f+8,", pc")