Re: [parisc-linux] binutils 2.15?

[Carlos O'Donell <carlos@baldric.uwo.ca>]

> There's a lazy linking stub inserted at the end of the .plt section that
> loads the .got address by
> 
>   b,l	1b,%r20
>   depi	0,31,2,%r20
> 
> ie. it depends on .got immediately following these instructions.

My apologies for a tardy reply.

We don't *have* to depend on the .got immediately following these
instructions. Technically we look for a signature at the end of the PLT.
The code in glibc looks beyond the last relocation in the following 
equation:

ptr = reloc->r_offset + l_addr + PLT_ENTRY_SIZE + SIZEOF_PLT_STUB

And if it finds the signature at ptr[-2] and ptr[-1], then it
acknowledges that as the PLT stub. It then by proxy knows that the GOT
should be at ptr[0], but it doesn't have to rely strictly on this, I'm
more than willing to add more code to glibc to remove this restriction.

I just don't really know how other arches find the GOT at this early 
stage in ld.so's startup (e.g. elf_machine_runtime_setup()).

The only reason we use the GOT here is because we want to identify the
shared object by storing a pointer to the DSO link_map into GOT[1]. 
Which to tell you the truth, I'm sure has to do with something in 
binutils that I currently don't understand.

I'm slowly reviewing the binutils hppa code because I'd like to clean it
up / understand it enough to add TLS.

Jakub, I hope this helps, if someone has an idea then I would be more
than happy to implement the change and test the resulting
binutils/glibc.

Cheers,
Carlos.