kprobes: Allow kprobes coexist with livepatch (0bc11ed5) · Commits · 戴 / test

kernel/kprobes.c

+40 −16

Original line number	Original line	Diff line number	Diff line
	@@ -961,9 +961,16 @@ static struct kprobe alloc_aggr_kprobe(struct kprobe p)

	#ifdef CONFIG_KPROBES_ON_FTRACE		#ifdef CONFIG_KPROBES_ON_FTRACE
	static struct ftrace_ops kprobe_ftrace_ops __read_mostly = {		static struct ftrace_ops kprobe_ftrace_ops __read_mostly = {
			.func = kprobe_ftrace_handler,
			.flags = FTRACE_OPS_FL_SAVE_REGS,
			};

			static struct ftrace_ops kprobe_ipmodify_ops __read_mostly = {
	.func = kprobe_ftrace_handler,		.func = kprobe_ftrace_handler,
	.flags = FTRACE_OPS_FL_SAVE_REGS \| FTRACE_OPS_FL_IPMODIFY,		.flags = FTRACE_OPS_FL_SAVE_REGS \| FTRACE_OPS_FL_IPMODIFY,
	};		};

			static int kprobe_ipmodify_enabled;
	static int kprobe_ftrace_enabled;		static int kprobe_ftrace_enabled;

	/* Must ensure p->addr is really on ftrace */		/* Must ensure p->addr is really on ftrace */
	@@ -976,58 +983,75 @@ static int prepare_kprobe(struct kprobe *p)
	}		}

	/* Caller must lock kprobe_mutex */		/* Caller must lock kprobe_mutex */
	static int arm_kprobe_ftrace(struct kprobe *p)		static int __arm_kprobe_ftrace(struct kprobe p, struct ftrace_ops ops,
			int *cnt)
	{		{
	int ret = 0;		int ret = 0;

	ret = ftrace_set_filter_ip(&kprobe_ftrace_ops,		ret = ftrace_set_filter_ip(ops, (unsigned long)p->addr, 0, 0);
	(unsigned long)p->addr, 0, 0);
	if (ret) {		if (ret) {
	pr_debug("Failed to arm kprobe-ftrace at %pS (%d)\n",		pr_debug("Failed to arm kprobe-ftrace at %pS (%d)\n",
	p->addr, ret);		p->addr, ret);
	return ret;		return ret;
	}		}

	if (kprobe_ftrace_enabled == 0) {		if (*cnt == 0) {
	ret = register_ftrace_function(&kprobe_ftrace_ops);		ret = register_ftrace_function(ops);
	if (ret) {		if (ret) {
	pr_debug("Failed to init kprobe-ftrace (%d)\n", ret);		pr_debug("Failed to init kprobe-ftrace (%d)\n", ret);
	goto err_ftrace;		goto err_ftrace;
	}		}
	}		}

	kprobe_ftrace_enabled++;		(*cnt)++;
	return ret;		return ret;

	err_ftrace:		err_ftrace:
	/*		/*
	* Note: Since kprobe_ftrace_ops has IPMODIFY set, and ftrace requires a		* At this point, sinec ops is not registered, we should be sefe from
	* non-empty filter_hash for IPMODIFY ops, we're safe from an accidental		* registering empty filter.
	* empty filter_hash which would undesirably trace all functions.
	*/		*/
	ftrace_set_filter_ip(&kprobe_ftrace_ops, (unsigned long)p->addr, 1, 0);		ftrace_set_filter_ip(ops, (unsigned long)p->addr, 1, 0);
	return ret;		return ret;
	}		}

			static int arm_kprobe_ftrace(struct kprobe *p)
			{
			bool ipmodify = (p->post_handler != NULL);

			return __arm_kprobe_ftrace(p,
			ipmodify ? &kprobe_ipmodify_ops : &kprobe_ftrace_ops,
			ipmodify ? &kprobe_ipmodify_enabled : &kprobe_ftrace_enabled);
			}

	/* Caller must lock kprobe_mutex */		/* Caller must lock kprobe_mutex */
	static int disarm_kprobe_ftrace(struct kprobe *p)		static int __disarm_kprobe_ftrace(struct kprobe p, struct ftrace_ops ops,
			int *cnt)
	{		{
	int ret = 0;		int ret = 0;

	if (kprobe_ftrace_enabled == 1) {		if (*cnt == 1) {
	ret = unregister_ftrace_function(&kprobe_ftrace_ops);		ret = unregister_ftrace_function(ops);
	if (WARN(ret < 0, "Failed to unregister kprobe-ftrace (%d)\n", ret))		if (WARN(ret < 0, "Failed to unregister kprobe-ftrace (%d)\n", ret))
	return ret;		return ret;
	}		}

	kprobe_ftrace_enabled--;		(*cnt)--;

	ret = ftrace_set_filter_ip(&kprobe_ftrace_ops,		ret = ftrace_set_filter_ip(ops, (unsigned long)p->addr, 1, 0);
	(unsigned long)p->addr, 1, 0);
	WARN_ONCE(ret < 0, "Failed to disarm kprobe-ftrace at %pS (%d)\n",		WARN_ONCE(ret < 0, "Failed to disarm kprobe-ftrace at %pS (%d)\n",
	p->addr, ret);		p->addr, ret);
	return ret;		return ret;
	}		}

			static int disarm_kprobe_ftrace(struct kprobe *p)
			{
			bool ipmodify = (p->post_handler != NULL);

			return __disarm_kprobe_ftrace(p,
			ipmodify ? &kprobe_ipmodify_ops : &kprobe_ftrace_ops,
			ipmodify ? &kprobe_ipmodify_enabled : &kprobe_ftrace_enabled);
			}
	#else /* !CONFIG_KPROBES_ON_FTRACE */		#else /* !CONFIG_KPROBES_ON_FTRACE */
	#define prepare_kprobe(p) arch_prepare_kprobe(p)		#define prepare_kprobe(p) arch_prepare_kprobe(p)
	#define arm_kprobe_ftrace(p) (-ENODEV)		#define arm_kprobe_ftrace(p) (-ENODEV)

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