tracing: Have stack_tracer use a separate list of functions (d2d45c7a) · Commits · 戴 / test

The stack_tracer is used to look at every function and check if the current stack is bigger than the last recorded max stack size. When a new max is found, then it saves that stack off. Currently the stack tracer is limited by the global_ops of the function tracer. As the stack tracer has nothing to do with the ftrace function tracer, except that it uses it as its internal engine, the stack tracer should have its own list. A new file is added to the tracing debugfs directory called: stack_trace_filter that can be used to select which functions you want to check the stack on. Signed-off-by:

Steven Rostedt <rostedt@goodmis.org>

kernel/trace/trace_stack.c

+18 −1

Original line number	Diff line number	Diff line
		@@ -133,7 +133,6 @@ stack_trace_call(unsigned long ip, unsigned long parent_ip)
		static struct ftrace_ops trace_ops __read_mostly =
		{
		.func = stack_trace_call,
		.flags = FTRACE_OPS_FL_GLOBAL,
		};

		static ssize_t
		@@ -311,6 +310,21 @@ static const struct file_operations stack_trace_fops = {
		.release = seq_release,
		};

		static int
		stack_trace_filter_open(struct inode inode, struct file file)
		{
		return ftrace_regex_open(&trace_ops, FTRACE_ITER_FILTER,
		inode, file);
		}

		static const struct file_operations stack_trace_filter_fops = {
		.open = stack_trace_filter_open,
		.read = seq_read,
		.write = ftrace_filter_write,
		.llseek = ftrace_regex_lseek,
		.release = ftrace_regex_release,
		};

		int
		stack_trace_sysctl(struct ctl_table *table, int write,
		void __user buffer, size_t lenp,
		@@ -358,6 +372,9 @@ static __init int stack_trace_init(void)
		trace_create_file("stack_trace", 0444, d_tracer,
		NULL, &stack_trace_fops);

		trace_create_file("stack_trace_filter", 0444, d_tracer,
		NULL, &stack_trace_filter_fops);

		if (stack_tracer_enabled)
		register_ftrace_function(&trace_ops);

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