Re: [PATCH 14/22] parisc: %pF is only for function pointers

From: Aaro Koskinen
Date: Thu Mar 12 2015 - 15:48:42 EST


Hi,

On Thu, Mar 12, 2015 at 02:04:41PM -0400, James Bottomley wrote:
> On Thu, 2015-03-12 at 11:14 -0500, Scott Wood wrote:
> > On Thu, 2015-03-12 at 08:11 -0400, James Bottomley wrote:
> > > On Wed, 2015-03-11 at 22:13 -0500, Scott Wood wrote:
> > > > Use %pS for actual addresses, otherwise you'll get bad output
> > > > on arches like ppc64 where %pF expects a function descriptor. Even on
> > > > other architectures, refrain from setting a bad example that people
> > > > copy.
> > >
> > > Are you sure about this? Parisc64 is a function description
> > > architecture. There may be a misunderstanding about what
> > > __builtin_return_address(0) is supposed to return, but I'm certain the
> > > person who added the code thought it returned a function pointer, which
> > > on parisc64 would be a descriptor.
> >
> > I wasn't aware that parisc64 used descriptors, but I don't see how you'd
> > get one out of __builtin_return_address(0) since it's not usually a
> > function entry point (plus, GCC documents it as returning void *).
>
> I was more thinking that this message is printed for every boot with a
> superio chip (which is a lot of our boxes). How come no-one has
> complained on parisc64 if it's doing the wrong thing.

It's dead code behind #ifdef DEBUG_SUPERIO_INIT.

A.
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