Re: [PATCH] tracing: Fix infinite loop in ftrace_update_pid_func()

Matt Fleming
2009-09-29T09:50:57Z

On Mon, Sep 28, 2009 at 04:43:01PM +0100, Matt Fleming wrote:
> From: Matt Fleming <matthew.fleming@imgtec.com>
>
> When CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST is enabled
> __ftrace_trace_function contains the current trace function, not
> ftrace_trace_function. In ftrace_update_pid_func() we currently
> incorrectly assign the value of ftrace_trace_function to
> __ftrace_trace_funcion before returning.
>
> Without this patch it is possible to execute an infinite loop whereby
> ftrace_test_stop_func() calls __ftrace_trace_function, which was
> assigned ftrace_test_stop_func() in ftrace_update_pid_func().
>

Oops..

I just realised I've used the phrase "infinite loop" when what I meant
to say was "infinite recursion". Sorry, brain fart.