Re: [PATCH] Fix compile breakage caused by asmlinkage_protect

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

On Fri, Apr 11, 2008 at 07:46:48AM -0700, Linus Torvalds wrote:
> Ok, that's just _odd_.
> 
> > So just surround the new define with an #ifndef __ASSEMBLY__ to prevent
> > any side effects on asm code.
> 
> There are no side effects on asm code. It just adds a #define that 
> obviously won't be used.
> 
> Is the s390 assembler using some strange C pre-processor that is different 
> from the main C preprocessor and doesn't understand this pattern?
> 
> I really think you should fix *that*, because otherwise you'll hit these 
> kinds of bugs occasionally. There aren't that many asm files, it's not 
> worth it optimizing them to use some faster-but-stupider preprocessor.

FWIW, at least m68k and m32r cross-builds hit the same.  I think I've a very
good guess about the reasons:
arch/m32r/kernel/Makefile:EXTRA_AFLAGS  := -traditional
arch/m68k/fpsp040/Makefile:EXTRA_AFLAGS := -traditional
arch/m68k/ifpsp060/Makefile:EXTRA_AFLAGS := -traditional
arch/m68k/kernel/Makefile:EXTRA_AFLAGS := -traditional
arch/m68k/lib/Makefile:EXTRA_AFLAGS := -traditional
arch/m68k/math-emu/Makefile:EXTRA_AFLAGS := -traditional
arch/parisc/kernel/Makefile:AFLAGS_entry.o      := -traditional
arch/parisc/kernel/Makefile:AFLAGS_pacache.o := -traditional
arch/s390/kernel/Makefile:EXTRA_AFLAGS  := -traditional
arch/s390/lib/Makefile:EXTRA_AFLAGS := -traditional
arch/s390/math-emu/Makefile:EXTRA_AFLAGS := -traditional

and that gets us -traditional-cpp passed to cc1, with obvious resulting
unhappiness from vararg macro.