Re: [PATCH v3 6/7] tracing: Add snapshot action

From: Tom Zanussi
Date: Fri Aug 10 2018 - 10:07:22 EST


On Fri, 2018-08-10 at 16:04 +0900, Namhyung Kim wrote:
> On Thu, Aug 09, 2018 at 09:34:16AM -0500, Tom Zanussi wrote:
> > From: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>
> >
> > Add support for hist:handlerXXX($var).snapshot(), which will take a
> > snapshot of the current trace buffer whenever handlerXXX is hit.
> >
> > As a first user, this also adds snapshot() action support for the
> > onmax() handler i.e. hist:onmax($var).snapshot().
> >
> > Signed-off-by: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>
> > ---
>
> [SNIP]
> > +static struct track_data *track_data_alloc(unsigned int key_len,
> > + struct action_data
> > *action_data,
> > + struct
> > hist_trigger_data *hist_data)
> > +{
> > + struct track_data *data = kzalloc(sizeof(*data),
> > GFP_KERNEL);
> > + unsigned int size = TASK_COMM_LEN;
> > + struct hist_elt_data *elt_data;
> > +
> > + if (!data)
> > + return ERR_PTR(-ENOMEM);
> > +
> > + data->key = kzalloc(key_len, GFP_KERNEL);
> > + if (!data->key) {
> > + track_data_free(data);
> > + return ERR_PTR(-ENOMEM);
> > + }
> > +
> > + data->key_len = key_len;
> > + data->action_data = action_data;
> > + data->hist_data = hist_data;
> > +
> > + elt_data = kzalloc(sizeof(*elt_data), GFP_KERNEL);
> > + if (!elt_data) {
> > + track_data_free(data);
> > + return ERR_PTR(-ENOMEM);
> > + }
> > + elt_data->comm = kzalloc(size, GFP_KERNEL);
> > + if (!elt_data->comm) {
> > + track_data_free(data);
>
> It seems to leak 'elf_data' here.
>

Yep, it does - thanks for pointing that out.

Tom


> Thanks,
> Namhyung
>
>
> > + return ERR_PTR(-ENOMEM);
> > + }
> > +
> > + data->elt.private_data = elt_data;
> > +
> > + return data;
> > +}