Re: [PATCH v1 2/2] Mark functions with the __nocapture attribute

From: Joe Perches
Date: Wed Jun 29 2016 - 20:12:55 EST


On Wed, 2016-06-29 at 20:42 +0200, Emese Revfy wrote:
> On Tue, 28 Jun 2016 14:00:57 -0700 Joe Perches <joe@xxxxxxxxxxx> wrote:
> > On Tue, 2016-06-28 at 22:40 +0200, Emese Revfy wrote:
> > > On Tue, 28 Jun 2016 09:43:31 -0700 Joe Perches <joe@xxxxxxxxxxx> wrote:
> > > > On Tue, 2016-06-28 at 13:36 +0200, Emese Revfy wrote:
> > > > > The nocapture gcc attribute can be on functions only.
> > > > > The attribute takes one or more unsigned integer constants as parameters
> > > > > that specify the function argument(s) of const char* type to initify.
> > > > Perhaps this should be const <void>*
> > > For me function arguments are the values passed to a function call so
> > > the const char* type is good because this is the only one that the plugin handles
> > > (for now at least).
> > OK, but this function prototype specified takes a const void *
> >
> > +extern void * memcpy(void *, const void *, __kernel_size_t) __nocapture(2);
> What matters for the plugin is the type of the passed arguments (which can be const char*
> in the current implementation), not that of the parameters.

And how does this work when the prototype requires the compiler to
implicit cast to const void * before calling the function?