From: Ingo Molnar <mingo@kernel.org>
To: Jan Beulich <JBeulich@suse.com>
Cc: mingo@elte.hu, tglx@linutronix.de, hpa@zytor.com,
linux-kernel@vger.kernel.org,
Ricardo Neri <ricardo.neri-calderon@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@alien8.de>,
Stas Sergeev <stsp@list.ru>
Subject: Re: [PATCH] x86: add UMIP support
Date: Thu, 17 Nov 2016 07:52:13 +0100 [thread overview]
Message-ID: <20161117065213.GA10358@gmail.com> (raw)
In-Reply-To: <582C8CE3020000780011F475@prv-mh.provo.novell.com>
* Jan Beulich <JBeulich@suse.com> wrote:
> This is a small aid to security, hiding in particular the kernel address
> information otherwise available through SGDT/SIDT.
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> ---
> Main question here is whether to limit this to 64-bit (or at least
> !CONFIG_VM86) for the time being, or to disable it while running VM86
> mode code: Such code isn't unlikely to use SMSW (and one of SGDT/SIDT)
> to figure out whether it's running on an i286 or i386, as the EFLAGS
> based method recommended by Intel's SDM can't be relied upon there.
> ---
> Documentation/kernel-parameters.txt | 4 ++++
> arch/x86/include/asm/cpufeatures.h | 1 +
> arch/x86/include/uapi/asm/processor-flags.h | 2 ++
> arch/x86/kernel/cpu/common.c | 16 +++++++++++++++-
> 4 files changed, 22 insertions(+), 1 deletion(-)
Note that similar patches have been submitted a week ago:
https://lkml.org/lkml/2016/11/8/68
Thanks,
Ingo
next prev parent reply other threads:[~2016-11-17 6:52 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-16 15:44 [PATCH] x86: add UMIP support Jan Beulich
2016-11-17 6:52 ` Ingo Molnar [this message]
2016-11-17 23:27 ` Ricardo Neri
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