Re: [PATCH v2 5.4 regression fix] x86/boot: Provide memzero_explicit

[Arvind Sankar]

 On Mon, Oct 07, 2019 at 05:40:07PM +0200, Ingo Molnar wrote:
> 
> * Arvind Sankar <nivedita@xxxxxxxxxxxx> wrote:
> 
> > With the barrier in there, is there any reason to *not* inline the
> > function? barrier_data() is an asm statement that tells the compiler
> > that the asm uses the memory that was set to zero, thus preventing it
> > from removing the memset even if nothing else uses that memory later. A
> > more detailed comment is there in compiler-gcc.h. I can't see why it
> > wouldn't work even if it were inlined.
> > 
> > If the function can indeed be inlined, we could just make the common
> > implementation a macro and avoid duplicating it? As mentioned in another
> > mail, we otherwise will likely need another duplicate implementation for
> > arch/s390/purgatory as well.
> 
> I suspect macro would be justified in this case. Mind sending a v3 patch 
> to demonstrate how it would all look like?
> 
> I'll zap v2 if the macro solution looks better.
> 
> Thanks,
> 
> 	Ingo

Patch attached to turn memzero_explicit into inline function.