On Wed, 15 Jan 2025 21:40:40 +0300
Dan Carpenter [off-list ref] wrote:

On Wed, Jan 15, 2025 at 07:58:30PM +0200, Costa Shulyupin wrote:

quoted

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