Re: reference_discarded addition

[Keith Owens <kaos@sgi.com>]

Dave Jones (on Fri, 6 Jan 2006 02:40:19 -0500) wrote:
>Error: ./fs/quota_v2.o .opd refers to 0000000000000020 R_PPC64_ADDR64    .exit.text
>
>Been carrying this for some time in Red Hat trees.
>
>Signed-off-by: Dave Jones <davej@redhat.com>
>
>diff -urNp --exclude-from=/home/davej/.exclude linux-3022/scripts/reference_discarded.pl linux-10000/scripts/reference_discarded.pl
>--- linux-3022/scripts/reference_discarded.pl
>+++ linux-10000/scripts/reference_discarded.pl
>@@ -88,6 +88,7 @@ foreach $object (keys(%object)) {
> 		    ($from !~ /\.text\.exit$/ &&
> 		     $from !~ /\.exit\.text$/ &&
> 		     $from !~ /\.data\.exit$/ &&
>+		     $from !~ /\.opd$/ &&
> 		     $from !~ /\.exit\.data$/ &&
> 		     $from !~ /\.altinstructions$/ &&
> 		     $from !~ /\.pdr$/ &&

For our future {in}sanity, add a comment that this is the ppc .opd
section, not the ia64 .opd section.  ia64 .opd should not point to
discarded sections.

Any idea why ppc .opd points to discarded sections when ia64 does not?
AFAICT no ia64 object has a useful .opd section, they are all empty or
(sometimes) a dummy entry which is 1 byte long.  ia64 .opd data is
built at link time, not compile time.

It is a pity that ppc is generating .opd entries at compile time.  It
makes it impossible to detect a real reference to a discarded function.