From: "H. Peter Anvin" <hpa@zytor.com>
To: Kees Cook <keescook@chromium.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
"x86@kernel.org" <x86@kernel.org>,
"kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>,
Aaron Durbin <adurbin@google.com>,
Eric Northup <digitaleric@google.com>,
Julien Tinnes <jln@google.com>, Will Drewry <wad@google.com>,
Mathias Krause <minipli@googlemail.com>,
Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Subject: Re: [PATCH 3/7] x86, kaslr: find minimum safe relocation position
Date: Thu, 03 Oct 2013 15:46:50 -0700 [thread overview]
Message-ID: <524DF3DA.7060204@zytor.com> (raw)
In-Reply-To: <CAGXu5j+hm8whuGxJ9PBEdxrSwpdH9a-S5-7ReVmb+COyRo9=uw@mail.gmail.com>
On 10/03/2013 03:43 PM, Kees Cook wrote:
>> This is highly problematic. The standard protocol is to hoist the
>> initramfs as high as possible in memory, so this may really unacceptably
>> restrict the available range.
>
> Doesn't this depend on the boot loader's behavior?
It does, but the recommended (and *required* for compatibility with
older kernels) behavior is to hoist as high as possible.
>> It would be better to treat these the same as reserved regions in the
>> e820 map as far as the address space picking algorithm is concerned.
>
> Could this be considered a future optimization, or do you feel this is
> required even for this first patch series landing?
Yes, I consider it required because of the above.
-hpa
next prev parent reply other threads:[~2013-10-03 22:47 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-03 20:53 [PATCH v7 0/7] Kernel base address randomization on x86 Kees Cook
2013-10-03 20:53 ` [PATCH 1/7] x86, boot: move CPU flags out of cpucheck Kees Cook
2014-01-29 12:01 ` [PATCH] x86, boot: fix word-size assumptions in has_eflag() inline asm David Woodhouse
2014-01-29 16:57 ` Kees Cook
2014-01-29 17:13 ` [tip:x86/build] x86, boot: Fix word-size assumptions in has_eflag () " tip-bot for David Woodhouse
2014-01-30 9:09 ` Ingo Molnar
2014-01-30 10:28 ` Woodhouse, David
2014-01-30 11:00 ` [PATCH v2] " David Woodhouse
2014-01-30 13:45 ` H. Peter Anvin
2014-01-30 14:08 ` David Woodhouse
2014-01-30 16:10 ` [tip:x86/build] " tip-bot for David Woodhouse
2014-01-30 23:01 ` [PATCH v2] " David Rientjes
2013-10-03 20:53 ` [PATCH 2/7] x86, kaslr: return location from decompress_kernel Kees Cook
2013-10-03 20:53 ` [PATCH 3/7] x86, kaslr: find minimum safe relocation position Kees Cook
2013-10-03 22:23 ` H. Peter Anvin
2013-10-03 22:43 ` Kees Cook
2013-10-03 22:46 ` H. Peter Anvin [this message]
2013-10-03 20:53 ` [PATCH 4/7] x86, kaslr: select random base offset Kees Cook
2013-10-03 20:53 ` [PATCH 5/7] x86, kaslr: select memory region from e820 maps Kees Cook
2013-10-03 20:53 ` [PATCH 6/7] x86, kaslr: report kernel offset on panic Kees Cook
2013-10-03 20:53 ` [PATCH 7/7] x86, kaslr: raise max positions to 1GiB on x86_64 Kees Cook
-- strict thread matches above, loose matches on Subject: below --
2013-10-01 19:37 [PATCH v6 0/7] Kernel base address randomization Kees Cook
2013-10-01 19:37 ` [PATCH 3/7] x86, kaslr: find minimum safe relocation position Kees Cook
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