From: Kees Cook <kees@kernel.org>
To: luto@amacapital.net, wad@chromium.org, Mateusz Guzik <mjguzik@gmail.com>
Cc: Kees Cook <kees@kernel.org>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] seccomp: avoid the lock trip seccomp_filter_release in common case
Date: Mon, 24 Feb 2025 11:18:04 -0800 [thread overview]
Message-ID: <174042468261.3899124.11197404704577449998.b4-ty@kernel.org> (raw)
In-Reply-To: <20250213170911.1140187-1-mjguzik@gmail.com>
On Thu, 13 Feb 2025 18:09:10 +0100, Mateusz Guzik wrote:
> Vast majority of threads don't have any seccomp filters, all while the
> lock taken here is shared between all threads in given process and
> frequently used.
>
> Safety of the check relies on the following:
> - seccomp_filter_release is only legally called for PF_EXITING threads
> - SIGNAL_GROUP_EXIT is only ever set with the sighand lock held
> - PF_EXITING is only ever set with the sighand lock held *or* after
> SIGNAL_GROUP_EXIT is set *or* the process is single-threaded
> - seccomp_sync_threads holds the sighand lock and skips all threads if
> SIGNAL_GROUP_EXIT is set, PF_EXITING threads if not
>
> [...]
Applied to for-next/seccomp, thanks!
[1/1] seccomp: avoid the lock trip seccomp_filter_release in common case
https://git.kernel.org/kees/c/8f19331384e6
Take care,
--
Kees Cook
prev parent reply other threads:[~2025-02-24 19:18 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-13 17:09 Mateusz Guzik
2025-02-24 19:18 ` Kees Cook [this message]
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