diff options
| author | Jon Medhurst (Tixy) <tixy@yxit.co.uk> | 2011-11-29 08:16:02 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2011-11-30 23:54:54 +0000 |
| commit | b5bed7fe801d1460424b7aeb6b06464e23d2a1e6 (patch) | |
| tree | d7908f55743de30fa49d5cf01ad2c5aeafebf8eb /arch/arm | |
| parent | 14383c295ab48178c449336f5d74e9e615e36723 (diff) | |
ARM: 7181/1: Restrict kprobes probing SWP instructions to ARMv5 and below
The SWP instruction is deprecated on ARMv6 and with ARMv7 it will be
UNDEFINED when CONFIG_SWP_EMULATE is selected. In this case, probing a
SWP instruction will cause an oops when the kprobes emulation code
executes an undefined instruction.
As the SWP instruction should be rare or non-existent in kernels for
ARMv6 and later, we can simply avoid these problems by not allowing
probing of these.
Reported-by: Leif Lindholm <leif.lindholm@arm.com>
Tested-by: Leif Lindholm <leif.lindholm@arm.com>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/kernel/kprobes-arm.c | 4 | ||||
| -rw-r--r-- | arch/arm/kernel/kprobes-test-arm.c | 25 |
2 files changed, 19 insertions, 10 deletions
diff --git a/arch/arm/kernel/kprobes-arm.c b/arch/arm/kernel/kprobes-arm.c index 9fe8910308af..8a30c89da70e 100644 --- a/arch/arm/kernel/kprobes-arm.c +++ b/arch/arm/kernel/kprobes-arm.c @@ -519,10 +519,12 @@ static const union decode_item arm_cccc_0000_____1001_table[] = { static const union decode_item arm_cccc_0001_____1001_table[] = { /* Synchronization primitives */ +#if __LINUX_ARM_ARCH__ < 6 + /* Deprecated on ARMv6 and may be UNDEFINED on v7 */ /* SMP/SWPB cccc 0001 0x00 xxxx xxxx xxxx 1001 xxxx */ DECODE_EMULATEX (0x0fb000f0, 0x01000090, emulate_rd12rn16rm0_rwflags_nopc, REGS(NOPC, NOPC, 0, 0, NOPC)), - +#endif /* LDREX/STREX{,D,B,H} cccc 0001 1xxx xxxx xxxx xxxx 1001 xxxx */ /* And unallocated instructions... */ DECODE_END diff --git a/arch/arm/kernel/kprobes-test-arm.c b/arch/arm/kernel/kprobes-test-arm.c index edf9ad8d3c6b..ba32b393b3f0 100644 --- a/arch/arm/kernel/kprobes-test-arm.c +++ b/arch/arm/kernel/kprobes-test-arm.c @@ -427,18 +427,25 @@ void kprobe_arm_test_cases(void) TEST_GROUP("Synchronization primitives") - /* - * Use hard coded constants for SWP instructions to avoid warnings - * about deprecated instructions. - */ - TEST_RP( ".word 0xe108e097 @ swp lr, r",7,VAL2,", [r",8,0,"]") - TEST_R( ".word 0x610d0091 @ swpvs r0, r",1,VAL1,", [sp]") - TEST_RP( ".word 0xe10cd09e @ swp sp, r",14,VAL2,", [r",12,13*4,"]") +#if __LINUX_ARM_ARCH__ < 6 + TEST_RP("swp lr, r",7,VAL2,", [r",8,0,"]") + TEST_R( "swpvs r0, r",1,VAL1,", [sp]") + TEST_RP("swp sp, r",14,VAL2,", [r",12,13*4,"]") +#else + TEST_UNSUPPORTED(".word 0xe108e097 @ swp lr, r7, [r8]") + TEST_UNSUPPORTED(".word 0x610d0091 @ swpvs r0, r1, [sp]") + TEST_UNSUPPORTED(".word 0xe10cd09e @ swp sp, r14 [r12]") +#endif TEST_UNSUPPORTED(".word 0xe102f091 @ swp pc, r1, [r2]") TEST_UNSUPPORTED(".word 0xe102009f @ swp r0, pc, [r2]") TEST_UNSUPPORTED(".word 0xe10f0091 @ swp r0, r1, [pc]") - TEST_RP( ".word 0xe148e097 @ swpb lr, r",7,VAL2,", [r",8,0,"]") - TEST_R( ".word 0x614d0091 @ swpvsb r0, r",1,VAL1,", [sp]") +#if __LINUX_ARM_ARCH__ < 6 + TEST_RP("swpb lr, r",7,VAL2,", [r",8,0,"]") + TEST_R( "swpvsb r0, r",1,VAL1,", [sp]") +#else + TEST_UNSUPPORTED(".word 0xe148e097 @ swpb lr, r7, [r8]") + TEST_UNSUPPORTED(".word 0x614d0091 @ swpvsb r0, r1, [sp]") +#endif TEST_UNSUPPORTED(".word 0xe142f091 @ swpb pc, r1, [r2]") TEST_UNSUPPORTED(".word 0xe1100090") /* Unallocated space */ |