Re: [PATCH v4] tools/rtla: Add osnoise_trace_is_off()

From: Steven Rostedt
Date: Thu Jan 16 2025 - 19:34:36 EST


On Wed, 15 Jan 2025 21:40:40 +0300
Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:

> On Wed, Jan 15, 2025 at 07:58:30PM +0200, Costa Shulyupin wrote:
> > The original code accidentally works because offset of
> > `record->trace` is zero.
>
> It doesn't "accidentally work". The people who write this kind of
> code 100% understand what they are doing. They don't see it as
> anything complicated.

I'm taking this patch but I replaced the change log with the following text:

tools/rtla: Add osnoise_trace_is_off()

All of the users of trace_is_off() passes in &record->trace as the second
parameter, where record is a pointer to a struct osnoise_tool. This record
could be NULL and there is a hidden dependency that the trace field is the
first field to allow &record->trace to work with a NULL record pointer.

In order to make this code a bit more robust, as record shouldn't be
dereferenced if it is NULL, even if the code does work, create a new
function called osnoise_trace_is_off() that takes the pointer to a
struct osnoise_tool as its second parameter. This way it can properly test
if it is NULL before it dereferences it.

The old function trace_is_off() is removed and the function
osnoise_trace_is_off() is added into osnoise.c which is what the
struct osnoise_tool is associated with.


-- Steve