Re: [PATCH 2/2] tracing: Use strncpy instead of memcpy for string keys in hist triggers

Steven Rostedt
2019-03-04T21:56:57Z

On Mon, 4 Mar 2019 16:50:00 -0500
Steven Rostedt <rostedt@goodmis.org> wrote:

> > +++ b/kernel/trace/trace_events_hist.c
> > @@ -4695,9 +4695,10 @@ static inline void add_to_key(char *compound_key, void *key,
> > /* ensure NULL-termination */
> > if (size > key_field->size - 1)
> > size = key_field->size - 1;
> > - }
> >
> > - memcpy(compound_key + key_field->offset, key, size);
> > + strncpy(compound_key + key_field->offset, (char *)key, size);
> > + } else
> > + memcpy(compound_key + key_field->offset, key, size);
> > }
> >
>
> Shouldn't we use strncpy() in save_comm() too. Feels safer.

Note, if that is changed, it can be another patch. This one is fine as
is. I just was looking at other use cases of memcpy() in that file.

-- Steve