Re: [PATCH 0/2] tracing: Fix adding some modifiers to histogram values

Steven Rostedt
2023-03-02T13:19:04Z

I forgot to add Tom Zanussi on this series.

-- Steve

On Wed, 01 Mar 2023 20:00:51 -0500
Steven Rostedt <rostedt@goodmis.org> wrote:

> Mark Rutland reported to me on IRC that he accidentally added the
> ".buckets=8" modifier to hitcount. This should not be allowed, but it
> did not error. Worse yet, when reading the hist file, it would crash
> as there was a NULL pointer dereference due to the values not having
> fields assigned to them.
>
> The first fix is to make sure that histogram values do not get assigned
> modifiers that they can't use.
>
> The the second patch is to not crash if a NULL pointer is passed to
> hist_field_name() (which is what happens if you allow some of these
> modifiers to be used by values).
>
> Steven Rostedt (Google) (2):
> tracing: Do not let histogram values have some modifiers
> tracing: Check field value in hist_field_name()
>
> ----
> kernel/trace/trace_events_hist.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)