[RFC PATCH 2/3] powerpc/pseries: Define & use a type for the plpar_hcall() retvals

[Balbir Singh]

On 18/10/16 19:40, Michael Ellerman wrote:
> We have now had two nasty stack corruption bugs caused by incorrect
> sizing of the return buffer for plpar_hcall()/plpar_hcall9().
> 
> To avoid any more such bugs, define a type which encodes the size of the
> return buffer, and change the argument of plpar_hcall() to be of that
> type, meaning the compiler will check for us that we passed the right
> size buffer.
> 
> There isn't an easy way to do this incrementally, without introducing a
> new function name, eg. plpar_hcall_with_struct(), which is ugly as hell.
> So just do it in one tree-wide change.
> 
Conceptually looks god, but I think we need to abstract the return values
as well. I'll test and see if I can send you something on top of this
Balbir