Re: [RFC][PATCH] x86: make text_poke() atomic

Mathieu Desnoyers
2009-03-02T18:36:42Z

* Arjan van de Ven (arjan@infradead.org) wrote:
> >
> > Use map_vm_area() instead of vmap() in text_poke() for avoiding page
> > allocation and delayed unmapping, and call vunmap_page_range() and
> > local_flush_tlb() directly because this mapping is temporary and
> > local.
> >
> > At the result of above change, text_poke() becomes atomic and can be
> > called from stop_machine() etc.
>
> .... but text_poke() realistically needs to call stop_machine() since
> you can't poke live code.... so that makes me wonder how useful this
> is...

Hi Arjan,

Stop machine is not required when inserting a breakpoint. And cleverly
using this breakpoint technique can permit modifying other instructions
as well.

Mathieu

--
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68