Re: [patch] 2.4.6-pre3 unresolved symbol do_softirq

Keith Owens
2001-06-13T13:58:50Z

On Wed, 13 Jun 2001 05:13:02 -0700 (PDT),
"David S. Miller" <davem@redhat.com> wrote:
>Keith Owens writes:
> > do_softirq is called from asm code which does not get preprocessed.
> > It needs to be exported with no version.
>
>It can get preprocessed if you know how. Simply use the "i" asm
>constraint for an extra argument, and use the symbol there. For
>example:
>
> __asm__("%0" : : "i" (my_versioned_symbol));
>
>It works and we've been doing it on sparc for ages.

It works for integers but call do_softirq is more of a problem. I
could not find an asm constraint that generated correct code in a
single instruction. The closest I could get was
__asm__("call *%%eax" : : "a" (do_softirq));
The 'obvious'
__asm__("call %0" : : "m" (do_softirq));
calls to a location that contains the address of do_softirq, oops.

Any other architectures that call do_softirq inside asm would need
similar hard coding of indirect branches. It is simpler to export
do_softirq with no version, and have cleaner asm.