From: "H. Peter Anvin" <hpa@zytor.com>
To: Yinghai Lu <yinghai@kernel.org>
Cc: Kees Cook <keescook@chromium.org>,
linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
x86@kernel.org, Jim Kukunas <james.t.kukunas@linux.intel.com>,
Arjan van de Ven <arjan@infradead.org>
Subject: Re: [RFC] stack and heap are executable on x86_64
Date: Fri, 21 Dec 2012 09:36:10 -0800 [thread overview]
Message-ID: <50D49E0A.1080609@zytor.com> (raw)
In-Reply-To: <CAE9FiQXcXn0xr_ACt4fS_=xWtXR8zGoYfpSzFKG4nEvKF=sGdQ@mail.gmail.com>
On 12/21/2012 09:28 AM, Yinghai Lu wrote:
>
> which line?
>
> 0xffffffff83000000-0xffffffff83c00000 12M RW PSE
> GLB x pmd
>
> my kernel INIT_SIZE is 27M, and it includes everything that i needed
> in the kernel.
>
We should NEVER have RW + x at the same time (at least when the kernel
is compiled properly.) Looks like your patch does get rid of a bunch of
stuff in the low mapping -- although the low mapping really should never
be +x at all -- but there are still problems with the high mapping.
Oh yes, and then there is EFI. If that means we need to keep a
completely separate page tables for EFI than so be it...
-hpa
next prev parent reply other threads:[~2012-12-21 17:36 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-21 3:00 [RFC] stack and heap are executable on x86_64 Kees Cook
2012-12-21 3:06 ` Kees Cook
2012-12-21 3:30 ` H. Peter Anvin
2012-12-21 4:44 ` H. Peter Anvin
2012-12-21 6:27 ` Yinghai Lu
2012-12-21 17:01 ` H. Peter Anvin
2012-12-21 17:28 ` Yinghai Lu
2012-12-21 17:36 ` H. Peter Anvin [this message]
2012-12-21 21:26 ` Yinghai Lu
2012-12-21 22:22 ` Yinghai Lu
2012-12-21 22:23 ` H. Peter Anvin
2012-12-21 22:26 ` Yinghai Lu
2012-12-21 22:28 ` H. Peter Anvin
2012-12-21 22:30 ` Yinghai Lu
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