[parisc-linux] [PATCH-2.5] Various cleanups

[John David Anglin]

> > I'm not applying these bits.  It's just not reasonable to add (void *)
> > casts to every function pointer comparison.  I know Linus will reject it.
> > We need to find a better way to fix this one -- and I suspect the right
> > way is to implement a __canonicalize_funcptr_for_compare in the kernel
> > and EXPORT_SYMBOL it.
> 
> I thougt about that, but didn't do it this way because I didn't like the
> approach to double libgcc's __canonicalize_funcptr_for_compare. Maybe
> we'd simply find a way to EXPORT_SYMBOL libgcc's version of that one...

No, you don't want to use the libgcc version as it is specific to
user programs.  A kernel version is needed.  I think all that needs to
be done is return the function pointer passed to it.  It should totally
disappear if inlined.  Thus, __canonicalize_funcptr_for_compare could
be defined in a header.

It might actually be necessary to do function pointer canonicalization
in the kernel in situations involving loadable modules.  One would
have to look at how the loader manages the plabels.

Dave
-- 
J. David Anglin                                  dave.anglin@nrc-cnrc.gc.ca
National Research Council of Canada              (613) 990-0752 (FAX: 952-6602)