On Wed, 29 Jun 2016 17:12:45 -0700 Joe Perches <j...@perches.com> wrote:
> On Wed, 2016-06-29 at 20:42 +0200, Emese Revfy wrote: > > On Tue, 28 Jun 2016 14:00:57 -0700 Joe Perches <j...@perches.com> wrote: > > > On Tue, 2016-06-28 at 22:40 +0200, Emese Revfy wrote: > > > > On Tue, 28 Jun 2016 09:43:31 -0700 Joe Perches <j...@perches.com> 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? The plugin searches for the nocapture attribute that does not depend on the type. If the function argument is not a string constant just a pointer then the plugin walks the data flow (use-def chain) and tries to find a string constant. If there is a cast to void * then the use-def chain will walk across it. -- Emese
