Need ld.so help

Need ld.so help

[Dan Malek]

I discovered the problem I am having with the embedded 8xx
processors and cache is that there are several assumptions
about cache block size in various functions.  The 8xx processors
have a 4 word (16 byte) cache line while other PPCs have
a 8 word line.  This causes problems when trying to flush and
invalidate caches.

One place this is done is dynamic linking functions of ld.so,
where it is assumed a cache line is 8 words.  Unfortunately,
I have been unable to build ld.so from the glibc SRPM.  I am
using the 961212-1h SRPM from the linuxppc.org server, and
the appropriate egcs and binutils.  All of the other libraries
I build from this SRPM are fine.  From looking at the RPM of
the same version, all of the resulting *.so files appear to be
nearly identical, except for ld.so which is much larger than
found in the RPM.

The details....I have tracked it down to the elf_get_dynamic_info()
function, called from _dl_start().  The failure occurs following
the 'while' loop.  It appears info[DT_RELA] is OK, or at least
not NULL.  However, info[DT_RELAENT] is NULL, causing the
program to segfault at this point.

I don't understand enough about the libraries to know where to
look from here, so I need some help :-)

Oh yeah, the SRPM didn't build quite right.  I had to hand patch
stdlib/exit.c.....

Thanks.


    -- Dan



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RE: Need ld.so help

[Gary Thomas]

On 27-Dec-98 Dan Malek wrote:
> 
> I discovered the problem I am having with the embedded 8xx
> processors and cache is that there are several assumptions
> about cache block size in various functions.  The 8xx processors
> have a 4 word (16 byte) cache line while other PPCs have
> a 8 word line.  This causes problems when trying to flush and
> invalidate caches.
> 
> One place this is done is dynamic linking functions of ld.so,
> where it is assumed a cache line is 8 words.  Unfortunately,
> I have been unable to build ld.so from the glibc SRPM.  I am
> using the 961212-1h SRPM from the linuxppc.org server, and
> the appropriate egcs and binutils.  All of the other libraries
> I build from this SRPM are fine.  From looking at the RPM of
> the same version, all of the resulting *.so files appear to be
> nearly identical, except for ld.so which is much larger than
> found in the RPM.
> 
> The details....I have tracked it down to the elf_get_dynamic_info()
> function, called from _dl_start().  The failure occurs following
> the 'while' loop.  It appears info[DT_RELA] is OK, or at least
> not NULL.  However, info[DT_RELAENT] is NULL, causing the
> program to segfault at this point.
> 
> I don't understand enough about the libraries to know where to
> look from here, so I need some help :-)
> 
> Oh yeah, the SRPM didn't build quite right.  I had to hand patch
> stdlib/exit.c.....
> 

I'm confused.  Are all of these problems attributable to the cache-line
size stuff?  Or are there other problems?

I [obviously] build the libraries directly from the SRPMS, so I'd like
to understand what your problems are.

Which software pieces are you running?
  EGCS?
  BINUTILS?
  GLIBC?
  Kernel?


------------------------------------------------------------------------
Gary Thomas                              |
email: gdt@linuxppc.org                  | "Fine wine is a necessity of
   ... opinions expressed here are mine  |        life for me"
       and no one else would claim them! |
                                         |      Thomas Jefferson
------------------------------------------------------------------------



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