From: Pavel Machek <pavel@ucw.cz>
To: Thomas Garnier <thgarnie@google.com>
Cc: "Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
"H . Peter Anvin" <hpa@zytor.com>,
"Jonathan Corbet" <corbet@lwn.net>,
"Andrey Ryabinin" <aryabinin@virtuozzo.com>,
"Alexander Potapenko" <glider@google.com>,
"Dmitry Vyukov" <dvyukov@google.com>,
"Lorenzo Stoakes" <lstoakes@gmail.com>,
"Kees Cook" <keescook@chromium.org>,
"Juergen Gross" <jgross@suse.com>,
"Andy Lutomirski" <luto@kernel.org>,
"Paul Gortmaker" <paul.gortmaker@windriver.com>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Michal Hocko" <mhocko@suse.com>, zijun_hu <zijun_hu@htc.com>,
"Chris Wilson" <chris@chris-wilson.co.uk>,
"Andy Lutomirski" <luto@amacapital.net>,
"Rafael J . Wysocki" <rjw@rjwysocki.net>,
"Len Brown" <len.brown@intel.com>,
"Jiri Kosina" <jikos@kernel.org>,
"Matt Fleming" <matt@codeblueprint.co.uk>,
"Ard Biesheuvel" <ard.biesheuvel@linaro.org>,
"Boris Ostrovsky" <boris.ostrovsky@oracle.com>,
"Rusty Russell" <rusty@rustcorp.com.au>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Borislav Petkov" <bp@suse.de>,
"Christian Borntraeger" <borntraeger@de.ibm.com>,
"Frederic Weisbecker" <fweisbec@gmail.com>,
"Luis R . Rodriguez" <mcgrof@kernel.org>,
"Stanislaw Gruszka" <sgruszka@redhat.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Josh Poimboeuf" <jpoimboe@redhat.com>,
"Vitaly Kuznetsov" <vkuznets@redhat.com>,
"Tim Chen" <tim.c.chen@linux.intel.com>,
"Joerg Roedel" <joro@8bytes.org>,
"Radim Krčmář" <rkrcmar@redhat.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
linux-doc@vger.kernel.org, kasan-dev@googlegroups.com,
linux-mm@kvack.org, linux-pm@vger.kernel.org,
linux-efi@vger.kernel.org, xen-devel@lists.xenproject.org,
lguest@lists.ozlabs.org, kvm@vger.kernel.org,
kernel-hardening@lists.openwall.com
Subject: Re: [PATCH v7 3/3] x86: Make the GDT remapping read-only on 64-bit
Date: Tue, 14 Mar 2017 22:04:24 +0100 [thread overview]
Message-ID: <20170314210424.GA5023@amd> (raw)
In-Reply-To: <20170314170508.100882-3-thgarnie@google.com>
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On Tue 2017-03-14 10:05:08, Thomas Garnier wrote:
> This patch makes the GDT remapped pages read-only to prevent corruption.
> This change is done only on 64-bit.
>
> The native_load_tr_desc function was adapted to correctly handle a
> read-only GDT. The LTR instruction always writes to the GDT TSS entry.
> This generates a page fault if the GDT is read-only. This change checks
> if the current GDT is a remap and swap GDTs as needed. This function was
> tested by booting multiple machines and checking hibernation works
> properly.
>
> KVM SVM and VMX were adapted to use the writeable GDT. On VMX, the
> per-cpu variable was removed for functions to fetch the original GDT.
> Instead of reloading the previous GDT, VMX will reload the fixmap GDT as
> expected. For testing, VMs were started and restored on multiple
> configurations.
>
> Signed-off-by: Thomas Garnier <thgarnie@google.com>
Can we get the same change for 32-bit, too? Growing differences
between 32 and 64 bit are a bit of a problem...
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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next prev parent reply other threads:[~2017-03-14 21:04 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-14 17:05 [PATCH v7 1/3] x86/mm: Adapt MODULES_END based on Fixmap section size Thomas Garnier
2017-03-14 17:05 ` [PATCH v7 2/3] x86: Remap GDT tables in the Fixmap section Thomas Garnier
2017-03-14 17:05 ` [PATCH v7 3/3] x86: Make the GDT remapping read-only on 64-bit Thomas Garnier
2017-03-14 21:04 ` Pavel Machek [this message]
2017-03-14 21:20 ` Thomas Garnier
2017-03-14 22:43 ` H. Peter Anvin
2017-03-15 13:52 ` [PATCH v7 1/3] x86/mm: Adapt MODULES_END based on Fixmap section size Boris Ostrovsky
2017-03-16 8:10 ` Ingo Molnar
2017-03-16 15:33 ` Thomas Garnier
2017-03-17 7:34 ` Ingo Molnar
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