tracing: Add stack_tracer_disable/enable() functions (5367278c) · Commits · 戴 / test

include/linux/ftrace.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -286,6 +286,12 @@ int
		stack_trace_sysctl(struct ctl_table *table, int write,
		void __user buffer, size_t lenp,
		loff_t *ppos);

		void stack_tracer_disable(void);
		void stack_tracer_enable(void);
		#else
		static inline void stack_tracer_disable(void) { }
		static inline void stack_tracer_enable(void) { }
		#endif

		struct ftrace_func_command {

+32 −0

Original line number	Diff line number	Diff line
		@@ -41,6 +41,38 @@ static DEFINE_MUTEX(stack_sysctl_mutex);
		int stack_tracer_enabled;
		static int last_stack_tracer_enabled;

		/**
		* stack_tracer_disable - temporarily disable the stack tracer
		*
		* There's a few locations (namely in RCU) where stack tracing
		* cannot be executed. This function is used to disable stack
		* tracing during those critical sections.
		*
		* This function must be called with preemption or interrupts
		* disabled and stack_tracer_enable() must be called shortly after
		* while preemption or interrupts are still disabled.
		*/
		void stack_tracer_disable(void)
		{
		/* Preemption or interupts must be disabled */
		if (IS_ENABLED(CONFIG_PREEMPT_DEBUG))
		WARN_ON_ONCE(!preempt_count() \|\| !irqs_disabled());
		this_cpu_inc(trace_active);
		}

		/**
		* stack_tracer_enable - re-enable the stack tracer
		*
		* After stack_tracer_disable() is called, stack_tracer_enable()
		* must be called shortly afterward.
		*/
		void stack_tracer_enable(void)
		{
		if (IS_ENABLED(CONFIG_PREEMPT_DEBUG))
		WARN_ON_ONCE(!preempt_count() \|\| !irqs_disabled());
		this_cpu_dec(trace_active);
		}

		void stack_trace_print(void)
		{
		long i;