0dc016dbd8
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>
13 lines
410 B
Makefile
13 lines
410 B
Makefile
obj-$(CONFIG_KPROBES) += core.o actions-common.o checkers-common.o
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obj-$(CONFIG_ARM_KPROBES_TEST) += test-kprobes.o
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test-kprobes-objs := test-core.o
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ifdef CONFIG_THUMB2_KERNEL
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obj-$(CONFIG_KPROBES) += actions-thumb.o checkers-thumb.o
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test-kprobes-objs += test-thumb.o
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else
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obj-$(CONFIG_KPROBES) += actions-arm.o checkers-arm.o
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obj-$(CONFIG_OPTPROBES) += opt-arm.o
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test-kprobes-objs += test-arm.o
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endif
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