From: "H. Peter Anvin" <hpa@zytor.com>
To: Kees Cook <keescook@chromium.org>, linux-kernel@vger.kernel.org
Cc: "Rik van Riel" <riel@redhat.com>,
"Andy Lutomirski" <luto@kernel.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
x86@kernel.org, "Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
"Yu-cheng Yu" <yu-cheng.yu@intel.com>,
"Masahiro Yamada" <yamada.masahiro@socionext.com>,
"Borislav Petkov" <bp@suse.de>,
"Christian Borntraeger" <borntraeger@de.ibm.com>,
"Thomas Garnier" <thgarnie@google.com>,
"Brian Gerst" <brgerst@gmail.com>,
"He Chen" <he.chen@linux.intel.com>,
"Mathias Krause" <minipli@googlemail.com>,
"Fenghua Yu" <fenghua.yu@intel.com>,
"Piotr Luc" <piotr.luc@intel.com>, "Kyle Huey" <me@kylehuey.com>,
"Len Brown" <len.brown@intel.com>,
kvm@vger.kernel.org, kernel-hardening@lists.openwall.com
Subject: Re: [PATCH] x86/fpu: move FPU state into separate cache
Date: Wed, 29 Mar 2017 13:45:32 -0700 [thread overview]
Message-ID: <ea0a7663-7318-6086-1cb8-25fd9a252f83@zytor.com> (raw)
In-Reply-To: <20170329203908.GA39222@beast>
On 03/29/17 13:39, Kees Cook wrote:
> This removes ARCH_WANTS_DYNAMIC_TASK_STRUCT from x86, leaving only s390
> still defining this config.
>
> In order to support future structure layout randomization of the
> task_struct, none of the structure fields are allowed to have a specific
> position or dynamic size. To enable randomization of task_struct on
> x86, the FPU state must be moved to its own dynamically sized cache,
> and dereferenced from the task_struct.
>
> This change is nearly identical to what was done in grsecurity to support
> structure layout randomization. Hopefully I found all the needed changes.
> This passes allyesconfig, and boot tests.
Is this really what we want to happen? It seems much more sane to
simply make them adjacent; they don't need to be part of the same
structure (in practice, there are three objects: thread_info,
task_struct, and the FPU state.)
-hpa
next prev parent reply other threads:[~2017-03-29 21:00 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-29 20:39 Kees Cook
2017-03-29 20:45 ` H. Peter Anvin [this message]
2017-03-29 21:09 ` Kees Cook
2017-03-29 21:19 ` Dave Hansen
2017-03-29 21:30 ` Linus Torvalds
2017-03-29 21:35 ` Andy Lutomirski
2017-03-29 21:41 ` Linus Torvalds
2017-03-29 22:28 ` hpa
2017-03-29 23:56 ` Linus Torvalds
2017-03-30 1:50 ` Kees Cook
2017-03-29 21:35 ` Linus Torvalds
2017-03-31 4:59 ` kbuild test robot
2017-03-31 5:57 ` kbuild test robot
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