[rfa/gdbserver] Fix ppc64 bi-arch TLS bug

[Daniel Jacobowitz]

On Wed, May 28, 2008 at 08:29:51PM +0200, Ulrich Weigand wrote:
> Hello,
> 
> this fixes another bug in ppc64 bi-arch gdbserver support: the
> ppc_collect_ptrace_register did not zero out the register buffer
> (in the case of a 4-byte inferior register on a 64-bit host).
> 
> This doesn't matter for the main user of this function
> (usr_store_inferior_registers in linux-low.c) which always
> zeros the buffer itself before passing it in.
> 
> However, there is a second caller, ps_lgetregs in proc-service.c
> (via the ppc_fill_gregset function) which does *not* zero the
> buffer.  This could cause TLS access to fail in some instances
> of 64->32 bit bi-arch debugging.
> 
> Fixed by simply always clearing the register buffer.
> 
> Tested on powerpc64-linux (-m64/-m32) and powerpc-linux using
> local gdbserver.
> 
> OK for mainline?

OK.

-- 
Daniel Jacobowitz
CodeSourcery