powerpc/kprobes: Remove redundant code (eb4f8e25) · Commits · 戴 / test

arch/powerpc/kernel/kprobes.c

+33 −48

Original line number	Diff line number	Diff line
		@@ -271,23 +271,45 @@ int kprobe_handler(struct pt_regs *regs)
		preempt_disable();
		kcb = get_kprobe_ctlblk();

		p = get_kprobe(addr);
		if (!p) {
		if (*addr != BREAKPOINT_INSTRUCTION) {
		/*
		* PowerPC has multiple variants of the "trap"
		* instruction. If the current instruction is a
		* trap variant, it could belong to someone else
		*/
		kprobe_opcode_t cur_insn = *addr;
		if (is_trap(cur_insn))
		goto no_kprobe;
		/*
		* The breakpoint instruction was removed right
		* after we hit it. Another cpu has removed
		* either a probepoint or a debugger breakpoint
		* at this address. In either case, no further
		* handling of this interrupt is appropriate.
		*/
		ret = 1;
		}
		/* Not one of ours: let kernel handle it */
		goto no_kprobe;
		}

		/* Check we're not actually recursing */
		if (kprobe_running()) {
		p = get_kprobe(addr);
		if (p) {
		kprobe_opcode_t insn = *p->ainsn.insn;
		if (kcb->kprobe_status == KPROBE_HIT_SS &&
		is_trap(insn)) {
		if (kcb->kprobe_status == KPROBE_HIT_SS && is_trap(insn)) {
		/* Turn off 'trace' bits */
		regs->msr &= ~MSR_SINGLESTEP;
		regs->msr \|= kcb->kprobe_saved_msr;
		goto no_kprobe;
		}
		/* We have reentered the kprobe_handler(), since
		* another probe was hit while within the handler.
		* We here save the original kprobes variables and
		* just single step on the instruction of the new probe
		* without calling any user handlers.

		/*
		* We have reentered the kprobe_handler(), since another probe
		* was hit while within the handler. We here save the original
		* kprobes variables and just single step on the instruction of
		* the new probe without calling any user handlers.
		*/
		save_previous_kprobe(kcb);
		set_current_kprobe(p, regs, kcb);
		@@ -304,43 +326,6 @@ int kprobe_handler(struct pt_regs *regs)
		}
		prepare_singlestep(p, regs);
		return 1;
		} else if (*addr != BREAKPOINT_INSTRUCTION) {
		/* If trap variant, then it belongs not to us */
		kprobe_opcode_t cur_insn = *addr;

		if (is_trap(cur_insn))
		goto no_kprobe;
		/* The breakpoint instruction was removed by
		* another cpu right after we hit, no further
		* handling of this interrupt is appropriate
		*/
		ret = 1;
		}
		goto no_kprobe;
		}

		p = get_kprobe(addr);
		if (!p) {
		if (*addr != BREAKPOINT_INSTRUCTION) {
		/*
		* PowerPC has multiple variants of the "trap"
		* instruction. If the current instruction is a
		* trap variant, it could belong to someone else
		*/
		kprobe_opcode_t cur_insn = *addr;
		if (is_trap(cur_insn))
		goto no_kprobe;
		/*
		* The breakpoint instruction was removed right
		* after we hit it. Another cpu has removed
		* either a probepoint or a debugger breakpoint
		* at this address. In either case, no further
		* handling of this interrupt is appropriate.
		*/
		ret = 1;
		}
		/* Not one of ours: let kernel handle it */
		goto no_kprobe;
		}

		kcb->kprobe_status = KPROBE_HIT_ACTIVE;

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