Re: [PATCH v5 0/9] ftrace with regs + live patching for ppc64 LE (ABI v2)

[Jiri Kosina]

On Thu, 21 Jan 2016, Torsten Duwe wrote:

> > mcount call sites looks normal on first sight...
> 
> Not quite.
> LR is not saved on the stack before the call.
> Argh!
> 
> Petr, this looks like 12 bytes offset for gcc-6.
> I think I can work around the rest.

Are we sure that gcc is doing the right thing here?

I am far from claiming understanding of ppc64 ABI, but from what Vojtech 
told me I understood that saving link register is necessary for (at least) 
graph tracer to work properly.

Thanks,

-- 
Jiri Kosina
SUSE Labs