Re: [RFC] firmware: annotate thou shalt not request fw on init or probe

From: Luis R. Rodriguez
Date: Thu Jun 16 2016 - 16:56:27 EST


On Thu, Sep 03, 2015 at 07:56:33AM +0200, Julia Lawall wrote:
>
>
> On Thu, 3 Sep 2015, Luis R. Rodriguez wrote:
>
> > On Sat, Aug 29, 2015 at 06:18:20PM +0200, Julia Lawall wrote:
> > > > +@ defines_module_init exists @
> > > > +declarer name module_init;
> > > > +identifier init;
> > > > +@@
> > > > +
> > > > +module_init(init);
> > > > +
> > > > +@ has_probe depends on defines_module_init @
> > > > +identifier drv_calls, drv_probe;
> > > > +type bus_driver;
> > > > +identifier probe_op =~ "(probe)";
> > > > +@@
> > > > +
> > > > +bus_driver drv_calls = {
> > > > + .probe_op = drv_probe,
> > > > +};
> > >
> > > I'm not sure that this is enough. For example, there is the macro
> > > platform_driver_probe that initializes probe fields. There is likewise
> > > module_platform_driver, which is a top-level declaration that encapsulates
> > > the module_init and the definition of the module_init function, which in
> > > turn calls platform_driver_probe. There is also module_platform_driver,
> > > which encapsulates the module_init, but not the initialization of the probe
> > > field. Are you concerned with any of these cases?
> >
> > Yes, and also it would seem this would only capture simple one level of
> > routine indirection, for instance if probe called bar() and it was within
> > bar() that the driver code called a fw request call, that would not be picked
> > up, correct?
>
> By default, Coccinelle is not interprocedural. You can encode that in the
> script, though.
>
> Probably the most convenient approach would be to start with the the call,
> and then work backward to the entry point. I have code to do this, if and
> when it turns out to be useful.

FYI folks, thanks to Coccinelle 1.0.5 this is now easily possible with
Python integration, a follow up patch will be submitted that uses this
mechanism to do a proper full search on the kernel.

Luis