From: Dave Hansen <dave.hansen@intel.com>
To: Rik van Riel <riel@surriel.com>, Thomas Gleixner <tglx@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
x86@kernel.org, linux-kernel@vger.kernel.org,
kernel-team@meta.com, Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>, Xin Li <xin@zytor.com>
Subject: Re: [PATCH] x86/entry: Read CR2 in asm entry stub to redcue NMI clobbering window
Date: Wed, 13 May 2026 10:12:59 -0700 [thread overview]
Message-ID: <669f925a-df4f-4497-ae41-46b08b6abce6@intel.com> (raw)
In-Reply-To: <1a39356971b5ba2c363ee47a80759595c8a69ecd.camel@surriel.com>
On 5/13/26 09:43, Rik van Riel wrote:
...
> I have only "seen" this in syzkaller, so I don't know
> what the symptoms would look like if a regular system
> hit this race window.
>
> I would not be surprised if we occasionally hit this
> in production, but given that I don't know what the
> symptoms would look like, I have no idea how often.
I don't think there's a concrete enough problem being solved here to
justify adding complexity to the entry code. Especially since it's not
even a robust solution for the problem.
The FRED thing is simple, robust, and doesn't affect the actual (nasty)
entry assembly.
I think we should do the FRED bits and continue to ignore the pre-FRED
problem.
next prev parent reply other threads:[~2026-05-13 17:13 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-13 16:12 [PATCH] x86/entry: Read CR2 in asm entry stub to redcue NMI clobbering window Rik van Riel
2026-05-13 16:31 ` Dave Hansen
2026-05-13 16:43 ` Rik van Riel
2026-05-13 17:12 ` Dave Hansen [this message]
2026-05-14 19:49 ` Andrew Cooper
2026-05-14 19:55 ` Dave Hansen
2026-05-14 18:09 ` kernel test robot
2026-05-14 22:54 ` kernel test robot
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