arm64: Remove unneeded rcu_read_lock from debug handlers (760d8ed0) · Commits · 戴 / test

arch/arm64/kernel/debug-monitors.c

+8 −6

Original line number	Diff line number	Diff line
		@@ -207,16 +207,16 @@ static int call_step_hook(struct pt_regs *regs, unsigned int esr)

		list = user_mode(regs) ? &user_step_hook : &kernel_step_hook;

		rcu_read_lock();

		/*
		* Since single-step exception disables interrupt, this function is
		* entirely not preemptible, and we can use rcu list safely here.
		*/
		list_for_each_entry_rcu(hook, list, node) {
		retval = hook->fn(regs, esr);
		if (retval == DBG_HOOK_HANDLED)
		break;
		}

		rcu_read_unlock();

		return retval;
		}
		NOKPROBE_SYMBOL(call_step_hook);
		@@ -305,14 +305,16 @@ static int call_break_hook(struct pt_regs *regs, unsigned int esr)

		list = user_mode(regs) ? &user_break_hook : &kernel_break_hook;

		rcu_read_lock();
		/*
		* Since brk exception disables interrupt, this function is
		* entirely not preemptible, and we can use rcu list safely here.
		*/
		list_for_each_entry_rcu(hook, list, node) {
		unsigned int comment = esr & ESR_ELx_BRK64_ISS_COMMENT_MASK;

		if ((comment & ~hook->mask) == hook->imm)
		fn = hook->fn;
		}
		rcu_read_unlock();

		return fn ? fn(regs, esr) : DBG_HOOK_ERROR;
		}