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* ARM: kprobes: Fix compilation error caused by superfluous '*'Jon Medhurst2015-02-101-1/+1
| | | | | | | | | | | | | There is a superfluous '*' in the definition of kprobe_decode_insn_t which on older versions of GCC (4.2.4) causes the compilation error: In file included from arch/arm/probes/kprobes/core.c:37: arch/arm/probes/kprobes/core.h:43: error: '[*]' not allowed in other than a declaration Fix this by removing the unneeded character. Reported-by: Janusz Użycki <j.uzycki@elproma.com.pl> Signed-off-by: Jon Medhurst <tixy@linaro.org>
* ARM: kprobes: Eliminate test code's use of BX instruction on ARMv4 CPUsJon Medhurst2015-01-202-3/+10
| | | | | | | Non-T variants of ARMv4 CPUs don't support the BX instruction so eliminate its use. Signed-off-by: Jon Medhurst <tixy@linaro.org>
* ARM: optprobes: execute instruction during restoring if possible.Wang Nan2015-01-141-2/+50
| | | | | | | | | | | | | | | This patch removes software emulation or simulation for most of probed instructions. If the instruction doesn't use PC relative addressing, it will be translated into following instructions in the restore code in code template: ldmia {r0 - r14} // restore all instruction except PC <instruction> // direct execute the probed instruction b next_insn // branch to next instruction. Signed-off-by: Wang Nan <wangnan0@huawei.com> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Jon Medhurst <tixy@linaro.org>
* ARM: kprobes: check register usage for probed instruction.Wang Nan2015-01-134-1/+102
| | | | | | | | | | | This patch utilizes the previously introduced checker to check register usage for probed ARM instruction and saves it in a mask. A further patch will use such information to avoid simulation or emulation. Signed-off-by: Wang Nan <wangnan0@huawei.com> Reviewed-by: Jon Medhurst <tixy@linaro.org> Signed-off-by: Jon Medhurst <tixy@linaro.org>
* ARM: kprobes: Fix unreliable MRS instruction testsJon Medhurst (Tixy)2015-01-134-19/+43
| | | | | | | | For the instruction 'mrs Rn, cpsr' the resulting value of Rn can vary due to external factors we can't control. So get the test code to mask out these indeterminate bits. Signed-off-by: Jon Medhurst <tixy@linaro.org>
* ARM: kprobes: enable OPTPROBES for ARM 32Wang Nan2015-01-134-7/+344
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduce kprobeopt for ARM 32. Limitations: - Currently only kernel compiled with ARM ISA is supported. - Offset between probe point and optinsn slot must not larger than 32MiB. Masami Hiramatsu suggests replacing 2 words, it will make things complex. Futher patch can make such optimization. Kprobe opt on ARM is relatively simpler than kprobe opt on x86 because ARM instruction is always 4 bytes aligned and 4 bytes long. This patch replace probed instruction by a 'b', branch to trampoline code and then calls optimized_callback(). optimized_callback() calls opt_pre_handler() to execute kprobe handler. It also emulate/simulate replaced instruction. When unregistering kprobe, the deferred manner of unoptimizer may leave branch instruction before optimizer is called. Different from x86_64, which only copy the probed insn after optprobe_template_end and reexecute them, this patch call singlestep to emulate/simulate the insn directly. Futher patch can optimize this behavior. Signed-off-by: Wang Nan <wangnan0@huawei.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Will Deacon <will.deacon@arm.com> Reviewed-by: Jon Medhurst (Tixy) <tixy@linaro.org> Signed-off-by: Jon Medhurst <tixy@linaro.org>
* ARM: kprobes: Add test cases for stack consuming instructionsJon Medhurst (Tixy)2015-01-133-2/+36
| | | | | | | | | | These have extra 'checker' functions associated with them so lets make sure those get covered by testing. As they may create uninitialised space on the stack we also update the test code to ensure such space is consistent between test runs. This is done by disabling interrupts in setup_test_context(). Signed-off-by: Jon Medhurst <tixy@linaro.org>
* ARM: kprobes: disallow probing stack consuming instructionsWang Nan2015-01-132-6/+19
| | | | | | | | | | | This patch prohibits probing instructions for which the stack requirements are unable to be determined statically. Some test cases are found not work again after the modification, this patch also removes them. Signed-off-by: Wang Nan <wangnan0@huawei.com> Reviewed-by: Jon Medhurst <tixy@linaro.org> Signed-off-by: Jon Medhurst <tixy@linaro.org>
* ARM: kprobes: collects stack consumption for store instructionsWang Nan2015-01-138-6/+382
| | | | | | | | | | This patch uses the previously introduced checker functionality on store instructions to record their stack consumption information to arch_probes_insn. Signed-off-by: Wang Nan <wangnan0@huawei.com> Reviewed-by: Jon Medhurst <tixy@linaro.org> Signed-off-by: Jon Medhurst <tixy@linaro.org>
* ARM: kprobes: introduces checkerWang Nan2015-01-0911-20/+95
| | | | | | | | | | | | This patch introdces 'checker' to decoding phase, and calls checkers when instruction decoding. This allows further decoding for specific instructions. This patch introduces a stub call of checkers in kprobe arch_prepare_kprobe() as an example and for further expansion. Signed-off-by: Wang Nan <wangnan0@huawei.com> Reviewed-by: Jon Medhurst <tixy@linaro.org> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Jon Medhurst <tixy@linaro.org>
* ARM: probes: Use correct action types for MOVW, SEV and WFIJon Medhurst2015-01-094-9/+3
| | | | | | | | | | | This doesn't correct any bugs when probing these instructions but makes MOVW slightly faster and makes everything more symmetric with the Thumb instruction cases. We can also remove the now redundant PROBES_EMULATE_NONE and PROBES_SIMULATE_NOP actions. Signed-off-by: Jon Medhurst <tixy@linaro.org>
* ARM: probes: move all probe code to dedicate directoryWang Nan2015-01-0921-0/+9715
In discussion on LKML (https://lkml.org/lkml/2014/11/28/158), Russell King suggests to move all probe related code to arch/arm/probes. This patch does the work. Due to dependency on 'arch/arm/kernel/patch.h', this patch also moves patch.h to 'arch/arm/include/asm/patch.h', and related '#include' directives are also midified to '#include <asm/patch.h>'. Following is an overview of this patch: ./arch/arm/kernel/ ./arch/arm/probes/ |-- Makefile |-- Makefile |-- probes-arm.c ==> |-- decode-arm.c |-- probes-arm.h ==> |-- decode-arm.h |-- probes-thumb.c ==> |-- decode-thumb.c |-- probes-thumb.h ==> |-- decode-thumb.h |-- probes.c ==> |-- decode.c |-- probes.h ==> |-- decode.h | |-- kprobes | | |-- Makefile |-- kprobes-arm.c ==> | |-- actions-arm.c |-- kprobes-common.c ==> | |-- actions-common.c |-- kprobes-thumb.c ==> | |-- actions-thumb.c |-- kprobes.c ==> | |-- core.c |-- kprobes.h ==> | |-- core.h |-- kprobes-test-arm.c ==> | |-- test-arm.c |-- kprobes-test.c ==> | |-- test-core.c |-- kprobes-test.h ==> | |-- test-core.h |-- kprobes-test-thumb.c ==> | `-- test-thumb.c | `-- uprobes | |-- Makefile |-- uprobes-arm.c ==> |-- actions-arm.c |-- uprobes.c ==> |-- core.c |-- uprobes.h ==> `-- core.h | `-- patch.h ==> arch/arm/include/asm/patch.h Signed-off-by: Wang Nan <wangnan0@huawei.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Jon Medhurst <tixy@linaro.org>
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