powerpc/kprobes: Factor out code to emulate instruction into a helper (1cabd2f8) · Commits · 戴 / test

arch/powerpc/kernel/kprobes.c

+31 −21

Original line number	Diff line number	Diff line
		@@ -207,6 +207,35 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
		regs->link = (unsigned long)kretprobe_trampoline;
		}

		int __kprobes try_to_emulate(struct kprobe p, struct pt_regs regs)
		{
		int ret;
		unsigned int insn = *p->ainsn.insn;

		/* regs->nip is also adjusted if emulate_step returns 1 */
		ret = emulate_step(regs, insn);
		if (ret > 0) {
		/*
		* Once this instruction has been boosted
		* successfully, set the boostable flag
		*/
		if (unlikely(p->ainsn.boostable == 0))
		p->ainsn.boostable = 1;
		} else if (ret < 0) {
		/*
		* We don't allow kprobes on mtmsr(d)/rfi(d), etc.
		* So, we should never get here... but, its still
		* good to catch them, just in case...
		*/
		printk("Can't step on instruction %x\n", insn);
		BUG();
		} else if (ret == 0)
		/* This instruction can't be boosted */
		p->ainsn.boostable = -1;

		return ret;
		}

		int __kprobes kprobe_handler(struct pt_regs *regs)
		{
		struct kprobe *p;
		@@ -302,18 +331,9 @@ int __kprobes kprobe_handler(struct pt_regs *regs)

		ss_probe:
		if (p->ainsn.boostable >= 0) {
		unsigned int insn = *p->ainsn.insn;
		ret = try_to_emulate(p, regs);

		/* regs->nip is also adjusted if emulate_step returns 1 */
		ret = emulate_step(regs, insn);
		if (ret > 0) {
		/*
		* Once this instruction has been boosted
		* successfully, set the boostable flag
		*/
		if (unlikely(p->ainsn.boostable == 0))
		p->ainsn.boostable = 1;

		if (p->post_handler)
		p->post_handler(p, regs, 0);

		@@ -321,17 +341,7 @@ ss_probe:
		reset_current_kprobe();
		preempt_enable_no_resched();
		return 1;
		} else if (ret < 0) {
		/*
		* We don't allow kprobes on mtmsr(d)/rfi(d), etc.
		* So, we should never get here... but, its still
		* good to catch them, just in case...
		*/
		printk("Can't step on instruction %x\n", insn);
		BUG();
		} else if (ret == 0)
		/* This instruction can't be boosted */
		p->ainsn.boostable = -1;
		}
		}
		prepare_singlestep(p, regs);
		kcb->kprobe_status = KPROBE_HIT_SS;

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