Re: [PATCH] NX protection for kernel data : fix 32 bits S3 suspend

From: Ingo Molnar <mingo@elte.hu>
To: castet.matthieu@free.fr
Cc: Linux Kernel list <linux-kernel@vger.kernel.org>,
	linux-security-module@vger.kernel.org,
	Matthias Hopf <mhopf@suse.de>,
	rjw@sisk.pl, Andrew Morton <akpm@linux-foundation.org>,
	"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH] NX protection for kernel data : fix 32 bits S3 suspend
Date: Wed, 2 Feb 2011 07:26:32 +0100	[thread overview]
Message-ID: <20110202062632.GA12256@elte.hu> (raw)
In-Reply-To: <1296566732.4d4809cc1f963@imp.free.fr>

* castet.matthieu@free.fr <castet.matthieu@free.fr> wrote:

> Quoting Ingo Molnar <mingo@elte.hu>:
> 
> >
> > * matthieu castet <castet.matthieu@free.fr> wrote:
> >
> > >  static inline int is_kernel_text(unsigned long addr)
> > >  {
> > > +#if defined(CONFIG_X86_32) && defined(CONFIG_ACPI_SLEEP)
> > > +	/*
> > > +	 * We need to make the wakeup trampoline in first 1MB !NX
> > > +	 */
> > > +	if (addr >= PAGE_OFFSET && addr <= (PAGE_OFFSET + (1<<20)))
> > > +		return 1;
> > > +#endif
> >
> > That's pretty ugly. Why not use set_memory_x()/set_memory_nx(), and only for
> > the
> > trampoline itself? Does the whole 1MB need to be marked X?
>
> The previous code was doing that.

So why not call set_memory_x() in your patch? Mind trying that?

Thanks,

	Ingo