Subject: Re: [PATCH 3/3 V13] RO/NX protection for loadable kernel

From: Kees Cook <[email-masked]>
Date: Fri, 10 Dec 2010 16:27:50 -0800

Hi,

On Sat, Dec 11, 2010 at 12:18:57AM +0100, mat wrote:
> Le Wed, 8 Dec 2010 14:19:51 -0800,
> Kees Cook <[email-masked]> a écrit :
> 
> > On Fri, Nov 26, 2010 at 06:23:55PM +0100, mat wrote:
> > > could you try the attached patch ?
> > > 
> > > on module load, we sort the __jump_table section. So we should make
> > > it writable.
> > > 
> > > 
> > > Matthieu
> > 
> > > diff --git a/arch/x86/include/asm/jump_label.h
> > > b/arch/x86/include/asm/jump_label.h index f52d42e..574dbc2 100644
> > > --- a/arch/x86/include/asm/jump_label.h
> > > +++ b/arch/x86/include/asm/jump_label.h
> > > @@ -14,7 +14,7 @@
> > >  	do
> > > {							\ asm
> > > goto("1:"					\
> > > JUMP_LABEL_INITIAL_NOP			\
> > > -			".pushsection __jump_table,  \"a\" \n\t"\
> > > +			".pushsection __jump_table,  \"aw\" \n\t"\
> > >  			_ASM_PTR "1b, %l[" #label "], %c0 \n\t" \
> > >  			".popsection \n\t"			\
> > >  			: :  "i" (key) :  : label);
> > > \
> > 
> > Acked-by: Kees Cook <[email-masked]>
> > 
> > Can this please get committed to tip?
> I think it is not need anymore with  Steven Rostedt patch [1]
> 
> Matthieu
> 
> [1]
> > > Here we set the text read only before we call the notifiers. The
> > > function tracer changes the calls to mcount into nops via a notifier
> > > call so this must be done after the module notifiers.

Which patch was that? (Or, rather, what's a good url to see it?)

-Kees

-- 
Kees Cook
Ubuntu Security Team