Re: [RFC] making HAVE_SYSCALL_WRAPPERS universal (Re: Issues with "x86, um: switch to generic fork/vfork/clone" commit)

[Al Viro <viro@ZenIV.linux.org.uk>]

On Tue, Jan 22, 2013 at 12:47:17PM +0000, James Hogan wrote:
> On 21/01/13 22:55, Al Viro wrote:
> > I've tried to sanitize cond_syscall/SYSCALL_ALIAS situation; the tree is in
> > git.kernel.org/pub/scm/linux/kernel/git/viro/signal experimental-syscalls
> > NOTE: this is absolutely untested and might very well blow up
> > on any number of architectures.
> > 
> > Review and comments would be very welcome.
> 
> Looking at "consolidate cond_syscall and SYSCALL_ALIAS declarations",
> is it worth having the default __SYMBOL_NAME declaration in
> include/linux/linkage.h make use of CONFIG_SYMBOL_PREFIX?
> 
> E.g. in the metag patchset we currently have the patch below.
> 
> Admittedly CONFIG_SYMBOL_PREFIX is a string which would make it's use in
> SYMBOL_NAME a bit awkward.

Umm...  TBH, I simply followed the existing macro (from h8300), but I really
suspect that it's better than your approach - sure, you leave populating the
syscall table to cc(1) and generally have fewer things in asm glue, but
you still have things like _clear_page, _ip_fast_csum, ___ashldi3, etc.
Having a macro converting C identifier to asm one might be a win for such
situations; if nothing else, it helps with grep - blackfin is a constant
source of annoyance, since e.g. git grep -n -w do_notify_resume will miss
things like
        pseudo_long_call _do_notify_resume, p5;

I'm not saying that SYMBOL_NAME is particulary good as identifiers go,
but the functionality is more useful than CONFIG_SYMBOL_PREFIX, IMO...