From: "Steven Rostedt (VMware)" <[email protected]> The "stack_trace_filter" file only makes sense if DYNAMIC_FTRACE is configured in. If it is not, then the user can not filter any functions.
Not only that, the open function causes warnings when DYNAMIC_FTRACE is not set. Link: http://lkml.kernel.org/r/[email protected] Reported-by: Arnd Bergmann <[email protected]> Signed-off-by: Steven Rostedt (VMware) <[email protected]> --- kernel/trace/trace_stack.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index b4a751e8f9d6..a4df67cbc711 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -406,6 +406,8 @@ static const struct file_operations stack_trace_fops = { .release = seq_release, }; +#ifdef CONFIG_DYNAMIC_FTRACE + static int stack_trace_filter_open(struct inode *inode, struct file *file) { @@ -423,6 +425,8 @@ static const struct file_operations stack_trace_filter_fops = { .release = ftrace_regex_release, }; +#endif /* CONFIG_DYNAMIC_FTRACE */ + int stack_trace_sysctl(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, @@ -477,8 +481,10 @@ static __init int stack_trace_init(void) trace_create_file("stack_trace", 0444, d_tracer, NULL, &stack_trace_fops); +#ifdef CONFIG_DYNAMIC_FTRACE trace_create_file("stack_trace_filter", 0444, d_tracer, &trace_ops, &stack_trace_filter_fops); +#endif if (stack_trace_filter_buf[0]) ftrace_set_early_filter(&trace_ops, stack_trace_filter_buf, 1); -- 2.10.2
