From mboxrd@z Thu Jan 1 00:00:00 1970 References: <20170314170508.100882-1-thgarnie@google.com> From: Boris Ostrovsky Message-ID: <799314af-e529-bc83-6322-54f5f5d28a40@oracle.com> Date: Wed, 15 Mar 2017 09:52:54 -0400 MIME-Version: 1.0 In-Reply-To: <20170314170508.100882-1-thgarnie@google.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: [kernel-hardening] Re: [PATCH v7 1/3] x86/mm: Adapt MODULES_END based on Fixmap section size To: Thomas Garnier , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Jonathan Corbet , Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , Lorenzo Stoakes , Kees Cook , Juergen Gross , Andy Lutomirski , Paul Gortmaker , Andrew Morton , Michal Hocko , zijun_hu , Chris Wilson , Andy Lutomirski , "Rafael J . Wysocki" , Len Brown , Pavel Machek , Jiri Kosina , Matt Fleming , Ard Biesheuvel , Rusty Russell , Paolo Bonzini , Borislav Petkov , Christian Borntraeger , Frederic Weisbecker , "Luis R . Rodriguez" , Stanislaw Gruszka , Peter Zijlstra , Josh Poimboeuf , Vitaly Kuznetsov , Tim Chen , Joerg Roedel , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= Cc: 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 List-ID: On 03/14/2017 01:05 PM, Thomas Garnier wrote: > This patch aligns MODULES_END to the beginning of the Fixmap section. > It optimizes the space available for both sections. The address is > pre-computed based on the number of pages required by the Fixmap > section. > > It will allow GDT remapping in the Fixmap section. The current > MODULES_END static address does not provide enough space for the kernel > to support a large number of processors. > > Signed-off-by: Thomas Garnier For Xen bits (and to some extent bare-metal): Reviewed-and-Tested-by: Boris Ostrovsky