forked from Minki/linux
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>
59 lines
1.8 KiB
C
59 lines
1.8 KiB
C
/*
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* arch/arm/kernel/kprobes.h
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*
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* Copyright (C) 2011 Jon Medhurst <tixy@yxit.co.uk>.
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*
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* Some contents moved here from arch/arm/include/asm/kprobes.h which is
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* Copyright (C) 2006, 2007 Motorola Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*/
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#ifndef _ARM_KERNEL_KPROBES_H
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#define _ARM_KERNEL_KPROBES_H
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#include <asm/kprobes.h>
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#include "../decode.h"
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/*
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* These undefined instructions must be unique and
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* reserved solely for kprobes' use.
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*/
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#define KPROBE_ARM_BREAKPOINT_INSTRUCTION 0x07f001f8
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#define KPROBE_THUMB16_BREAKPOINT_INSTRUCTION 0xde18
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#define KPROBE_THUMB32_BREAKPOINT_INSTRUCTION 0xf7f0a018
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extern void kprobes_remove_breakpoint(void *addr, unsigned int insn);
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enum probes_insn __kprobes
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kprobe_decode_ldmstm(kprobe_opcode_t insn, struct arch_probes_insn *asi,
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const struct decode_header *h);
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typedef enum probes_insn (kprobe_decode_insn_t)(probes_opcode_t,
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struct arch_probes_insn *,
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bool,
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const union decode_action *,
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const struct decode_checker *[*]);
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#ifdef CONFIG_THUMB2_KERNEL
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extern const union decode_action kprobes_t32_actions[];
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extern const union decode_action kprobes_t16_actions[];
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extern const struct decode_checker *kprobes_t32_checkers[];
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extern const struct decode_checker *kprobes_t16_checkers[];
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#else /* !CONFIG_THUMB2_KERNEL */
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extern const union decode_action kprobes_arm_actions[];
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extern const struct decode_checker *kprobes_arm_checkers[];
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#endif
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#endif /* _ARM_KERNEL_KPROBES_H */
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