Lock-up on PPC64

[Benjamin Herrenschmidt]

On Sun, 2009-02-22 at 11:35 +0300, malc wrote:
> After writing valgrind tool that was simulating Cell XER.SO syscall
> (mis)behaviour (pre ab598b6680f1e74c267d1547ee352f3e1e530f89 that is)
> and banging my had against the wall for a while trying to figure out
> which of the failing syscalls was responsible, i've tried to be simple
> and after only ~30 minutes came up with this, rather short, piece of
> code that knocks pre XER.SO patched kernels out cold:
> 
> gcc -o xer -x assembler /dev/stdin -nostdlib <<eof
> .globl _start
> _start:
>          addis 0,0,0x8000
>          mtxer 0
>          addi 0,0,1
>          sc

Allright, but the XER patch fixes it... interesting. Oh well, I'll try
to figure out at some stage where we get something wrong in those old
kernels.

Cheers,
Ben.