Re: [PATCH] check_netdev_priv: warn about using netdev priv data after free_netdev

[Dan Carpenter <dan.carpenter@oracle.com>]

On Tue, Aug 03, 2021 at 07:03:59PM +0300, Pavel Skripkin wrote:
> Hi, Dan!
> 
> On 8/3/21 6:08 PM, Dan Carpenter wrote:
> > Thanks Pavel!
> > 
> > It looks really nice.  I've applied it.  I'll test it tonight and push
> > tomorrow.
> > 
> > I don't see any major issues with the check at all, but I have a few
> > comments below.
> > 
> > On Tue, Aug 03, 2021 at 12:00:22AM +0300, Pavel Skripkin wrote:
> > > +static void match_free_netdev(const char *fn, struct expression *expr, void *_arg_no)
> > > +{
> > > +	struct expression *arg;
> > > +	const char *name;
> > > +
> > > +	arg = get_argument_from_call_expr(expr->args, PTR_INT(_arg_no));
> > > +	if (!arg)
> > > +		return;
> > > +
> > > +	name = expr_to_var(arg);
> > > +	if (!name)
> > > +		return;
> > > +
> > > +	set_state(my_id, name, NULL, &freed);
> > > +}
> > 
> > There is a new param_key API which would make this function shorter.
> > 
> > static void free_netdev(struct expression *expr, const char *name, struct symbol *sym, void *data)
> > {
> > 	set_state(my_id, name, NULL, &freed);
> > }
> > 
> > Then in the register function you'd add a hooks like this:
> > 
> > 	add_function_param_key_hook("free_netdev", &free_netdev, 0, "$", NULL);
> > 	add_function_param_key_hook("free_candev", &free_netdev, 0, "$", NULL);
> > 
> 
> I guess, I missed that API, sorry :( Next time I will use it instead.

It's new, I wouldn't have expected anyone to be aware of it yet.  But
it's really nice.

regards,
dan carpenter