Messages in this thread Patch in this message | | | From | Wang Nan <> | Subject | [RFC PATCH v3 23/26] early kprobes: x86: arch_restore_optimized_kprobe(). | Date | Fri, 13 Feb 2015 13:41:13 +0800 |
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arch_restore_optimized_kprobe() can be used to temporarily restore probed instruction. It will actually disable optimized kprobe, but keep the relatived data structure. It uses stop_machine() to enforce atimicity.
Signed-off-by: Wang Nan <wangnan0@huawei.com> --- arch/x86/kernel/kprobes/opt.c | 26 ++++++++++++++++++++++++++ include/linux/kprobes.h | 1 + 2 files changed, 27 insertions(+)
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c index f3ea954..12332c2 100644 --- a/arch/x86/kernel/kprobes/opt.c +++ b/arch/x86/kernel/kprobes/opt.c @@ -28,6 +28,7 @@ #include <linux/kdebug.h> #include <linux/kallsyms.h> #include <linux/ftrace.h> +#include <linux/stop_machine.h> #include <asm/cacheflush.h> #include <asm/desc.h> @@ -486,4 +487,29 @@ void arch_fix_ftrace_early_kprobe(struct optimized_kprobe *op) memcpy(&list_p->opcode, correct_nop5, sizeof(kprobe_opcode_t)); } + +static int do_restore_kprobe(void *p) +{ + struct optimized_kprobe *op = p; + u8 insn_buf[RELATIVEJUMP_SIZE]; + + memcpy(insn_buf, &op->kp.opcode, sizeof(kprobe_opcode_t)); + memcpy(insn_buf + INT3_SIZE, + op->optinsn.copied_insn, + RELATIVE_ADDR_SIZE); + text_poke(op->kp.addr, insn_buf, RELATIVEJUMP_SIZE); + return 0; +} + +void arch_restore_optimized_kprobe(struct optimized_kprobe *op) +{ + u32 mask = KPROBE_FLAG_EARLY | + KPROBE_FLAG_OPTIMIZED | + KPROBE_FLAG_FTRACE; + + if ((op->kp.flags & mask) != mask) + return; + + stop_machine(do_restore_kprobe, op, NULL); +} #endif diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index e483f1b..e615402 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -462,6 +462,7 @@ extern int arch_prepare_kprobe_ftrace(struct kprobe *p); #ifdef CONFIG_EARLY_KPROBES extern void arch_fix_ftrace_early_kprobe(struct optimized_kprobe *p); +extern void arch_restore_optimized_kprobe(struct optimized_kprobe *p); #endif #endif -- 1.8.4
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