Re: [PATCH 12/13] x86/jitalloc: prepare to allocate exectuatble memory as ROX

[Kent Overstreet]

On Thu, Jun 01, 2023 at 12:30:50PM +0200, Peter Zijlstra wrote:
> On Thu, Jun 01, 2023 at 01:12:56PM +0300, Mike Rapoport wrote:
> 
> > +static void __init_or_module do_text_poke(void *addr, const void *opcode, size_t len)
> > +{
> > +	if (system_state < SYSTEM_RUNNING) {
> > +		text_poke_early(addr, opcode, len);
> > +	} else {
> > +		mutex_lock(&text_mutex);
> > +		text_poke(addr, opcode, len);
> > +		mutex_unlock(&text_mutex);
> > +	}
> > +}
> 
> So I don't much like do_text_poke(); why?

Could you share why?

I think the impementation sucks but conceptually it's the right idea -
create a new temporary mapping to avoid the need for RWX mappings.