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| author | Rabin Vincent <rabin.vincent@stericsson.com> | 2012-07-04 10:37:37 +0400 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-07-05 15:57:16 +0400 |
| commit | f8b435bb918412c9410da4c4b0b02b6b3d99b27c (patch) | |
| tree | 437a95d7a2b25659172cb4353b1511152e216a1c /arch | |
| parent | fdeb8e35fd59e79dec385f98eb4b6d2e3398264b (diff) | |
| download | linux-f8b435bb918412c9410da4c4b0b02b6b3d99b27c.tar.xz | |
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')
| -rw-r--r-- | arch/arm/kernel/kprobes-test-arm.c | 4 |
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 */ #endif TEST_BB_R( "sub pc, pc, r",14, 1f-2f+8,"") TEST_BB_R( "rsb pc, r",14,1f-2f+8,", pc") |