From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: matthieu castet <castet.matthieu@free.fr>
Cc: linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-next@vger.kernel.org,
Arjan van de Ven <arjan@infradead.org>,
James Morris <jmorris@namei.org>,
Andrew Morton <akpm@linux-foundation.org>, Andi Kleen <ak@muc.de>,
Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@elte.hu>,
Rusty Russell <rusty@rustcorp.com.au>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Dave Jones <davej@redhat.com>,
Siarhei Liakh <sliakh.lkml@gmail.com>
Subject: Re: [PATCH 2/3 V8] [tip:x86/mm] NX protection for kernel data
Date: Tue, 21 Sep 2010 15:00:06 -0400 [thread overview]
Message-ID: <20100921190006.GA23067@dumpdata.com> (raw)
In-Reply-To: <4C8FB616.2070807@free.fr>
On Tue, Sep 14, 2010 at 07:51:18PM +0200, matthieu castet wrote:
> Hi,
>
> any feedback on that ?
I was hoping to run your patch through a Xen guest. In the past modifications
in that area caused unbootable kernels :-( But I am still suffering from
post-vacation-amnesia and e-mails so haven't gotten to look at this.
>
> Thanks,
>
> Matthieu
>
>
> matthieu castet a écrit :
> > Note: this patch depends on "Correct improper large page
> >preservation" patch
> > This patch expands functionality of CONFIG_DEBUG_RODATA to set main
> > (static) kernel data area as NX.
> > The following steps are taken to achieve this:
> > 1. Linker script is adjusted so .text always starts and ends on
> >a page bound
> > 2. Linker script is adjusted so .rodata always start and
> > end on a page boundary
> > 3. NX is set for all pages from _etext through _end in mark_rodata_ro.
> > 4. free_init_pages() sets released memory NX in arch/x86/mm/init.c
> > 5. bios rom is set to x when pcibios is used.
> > The results of patch application may be observed in the diff
> >of kernel page
> > table dumps.
> > pcibios :
> > --- data_nx_pt_before.txt 2009-10-13 07:48:59.000000000 -0400
> > +++ data_nx_pt_after.txt 2009-10-13 07:26:46.000000000 -0400
> > @@ -2,8 +2,9 @@
> > 0x00000000-0xc0000000 3G pmd
> > ---[ Kernel Mapping ]---
> > -0xc0000000-0xc0100000 1M RW GLB x pte
> > +0xc0000000-0xc00a0000 640K RW GLB NX pte
> > +0xc00a0000-0xc0100000 384K RW GLB x pte
> > -0xc0100000-0xc03d7000 2908K ro GLB x pte
> > +0xc0100000-0xc0318000 2144K ro GLB x pte
> > +0xc0318000-0xc03d7000 764K ro GLB NX pte
> > -0xc03d7000-0xc0600000 2212K RW GLB x pte
> > +0xc03d7000-0xc0600000 2212K RW GLB NX pte
> > 0xc0600000-0xf7a00000 884M RW PSE GLB NX pmd
> > 0xf7a00000-0xf7bfe000 2040K RW GLB NX pte
> > 0xf7bfe000-0xf7c00000 8K pte
> > no pcibios :
> > --- data_nx_pt_before.txt 2009-10-13 07:48:59.000000000 -0400
> > +++ data_nx_pt_after.txt 2009-10-13 07:26:46.000000000 -0400
> > @@ -2,8 +2,9 @@
> > 0x00000000-0xc0000000 3G pmd
> > ---[ Kernel Mapping ]---
> > -0xc0000000-0xc0100000 1M RW GLB x pte
> > +0xc0000000-0xc0100000 1M RW GLB NX pte
> > -0xc0100000-0xc03d7000 2908K ro GLB x pte
> > +0xc0100000-0xc0318000 2144K ro GLB x pte
> > +0xc0318000-0xc03d7000 764K ro GLB NX pte
> > -0xc03d7000-0xc0600000 2212K RW GLB x pte
> > +0xc03d7000-0xc0600000 2212K RW GLB NX pte
> > 0xc0600000-0xf7a00000 884M RW PSE GLB NX pmd
> > 0xf7a00000-0xf7bfe000 2040K RW GLB NX pte
> > 0xf7bfe000-0xf7c00000 8K pte
> > The patch have been developed for Linux 2.6.34-rc2 x86 by
> >Siarhei Liakh
> > <sliakh.lkml@gmail.com> and Xuxian Jiang <jiang@cs.ncsu.edu>.
> > V1: initial patch for 2.6.30
> > V2: patch for 2.6.31-rc7
> > V3: moved all code into arch/x86, adjusted credits
> > V4: fixed ifdef, removed credits from CREDITS
> > V5: fixed an address calculation bug in mark_nxdata_nx()
> > V6: added acked-by and PT dump diff to commit log
> > V7: minor adjustments for -tip
> > V8: rework with the merge of "Set first MB as RW+NX"
> > Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com>
> > Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu>
> > Signed-off-by: Matthieu CASTET <castet.matthieu@free.fr>
> >
>
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prev parent reply other threads:[~2010-09-21 19:00 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-06 21:50 [PATCH 2/3 V8] [tip:x86/mm] NX protection for kernel data matthieu castet
2010-09-14 17:51 ` matthieu castet
2010-09-21 19:00 ` Konrad Rzeszutek Wilk [this message]
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