[linuxsh-dev] A problem of SH PIC ABI

[kaz K. <kk...@rr...>]

Hi,

I'd like to report a problem of SH PIC ABI and changes of toolchain
needed for it.

Gcc usually uses r2 to pass the address of the returned structure when
the structure valued function is called. On the other hand, current SH
PLT code uses r0, r1 and r2. So such function never work in the shared
library. This problem was reported by Yaegashi-san when he ported debian
apt package.

I've written new PLT codes which use r0 and r1 only. This needs a tiny
change of the dynamic linker so to handle both old and new PLT codes.
With this change, we can use the old and new binaries at the same time.
This proposal was sent to the binutils mailing list and is approved.
Of course, it's an additional change of SH PIC ABI. I've talked with
Alexandre Oliva in Red Hat about this issue and he and I contacted with
Hitachi America and Japan guys who are responsible for this change. They
also approved it.
I've posted a patch for the dynamic linker to the libc mailing list and
it's approved now.
So, when you try to update the binutils from the sources in mainline cvs
and the SH local patch, please don't forget to update your libc too. If
you use your own dynamic linker, you have to fix it slightly.

Regards,
	kaz