On Fri, 9 Aug 2024 13:34:28 -0400 (EDT)
John Kacur <jkacur@xxxxxxxxxx> wrote:
> On Fri, 9 Aug 2024, Dan Carpenter wrote:
>
> > If the "tool->data" allocation fails then there is no need to call
> > osnoise_free_top() and, in fact, doing so will lead to a NULL dereference.
> >
> > Fixes: 1eceb2fc2ca5 ("rtla/osnoise: Add osnoise top mode")
> > Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> > ---
> > tools/tracing/rtla/src/osnoise_top.c | 11 ++++-------
> > 1 file changed, 4 insertions(+), 7 deletions(-)
> >
> > diff --git a/tools/tracing/rtla/src/osnoise_top.c b/tools/tracing/rtla/src/osnoise_top.c
> > index f594a44df840..2f756628613d 100644
> > --- a/tools/tracing/rtla/src/osnoise_top.c
> > +++ b/tools/tracing/rtla/src/osnoise_top.c
> > @@ -651,8 +651,10 @@ struct osnoise_tool *osnoise_init_top(struct osnoise_top_params *params)
> > return NULL;
> >
> > tool->data = osnoise_alloc_top(nr_cpus);
> > - if (!tool->data)
> > - goto out_err;
> > + if (!tool->data) {
> > + osnoise_destroy_tool(tool);
> > + return NULL;
> > + }
> >
> > tool->params = params;
> >
> > @@ -660,11 +662,6 @@ struct osnoise_tool *osnoise_init_top(struct osnoise_top_params *params)
> > osnoise_top_handler, NULL);
> >
> > return tool;
> > -
> > -out_err:
> > - osnoise_free_top(tool->data);
> > - osnoise_destroy_tool(tool);
> > - return NULL;
> > }
> >
> > static int stop_tracing;
> > --
>
> Although your fix appears to be correct, I wonder if it would be better to
> create a second error label, such as out_destroy_tool: as described in
> section 7 of the coding-style.rst
>
There's no reason for that. It's the only error path. That is, nothing
would jump to the original out_err:
And for a single error, an if statement is good enough.
-- Steve
