Re: [PATCH 1/1] lib, stackdepot: Add helper to print stack entries into buffer.

[imran . f . khan]

On 13/9/21 6:51 pm, Vlastimil Babka wrote:
> On 9/10/21 16:10, Imran Khan wrote:
> > To print stack entries into a buffer, users of stackdepot,
> > first get a list of stack entries using stack_depot_fetch
> > and then print this list into a buffer using stack_trace_snprint.
> > Provide a helper in stackdepot for this purpose.
> > Also change above mentioned users to use this helper.
> >
> > Signed-off-by: Imran Khan <imran.f.khan@xxxxxxxxxx>
> > Suggested-by: Vlastimil Babka <vbabka@xxxxxxx>
>
> Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Thanks for the review.

A comment below:
> > --- a/lib/stackdepot.c
> > +++ b/lib/stackdepot.c
> > @@ -214,6 +214,29 @@ static inline struct stack_record *find_stack(struct stack_record *bucket,
> >   	return NULL;
> >   }

[...]

> > + */
> > +int stack_depot_snprint(depot_stack_handle_t handle, char *buf, size_t size,
> > +		       int spaces)
> > +{
> > +	unsigned long *entries;
> > +	unsigned int nr_entries;
> > +
> > +	nr_entries = stack_depot_fetch(handle, &entries);
> > +	return stack_trace_snprint(buf, size, entries, nr_entries, 0);
>
> stack_trace_snprint() has a WARN_ON(!entries).
> So maybe we should not call it if nr_entries is 0 (because e.g. handle was
> 0) as the warnings are not useful in that case.
Agree. I have addressed this feedback in v2 of patch.


Thanks
-- Imran