From nobody Thu Dec 25 12:19:58 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E403822638; Wed, 17 Jan 2024 16:15:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705508111; cv=none; b=PIgYJawRp8KGcLl1nPR7I2ndMWRaRL/807XYJOcQWTgOYaxXm6OMH593HvTt1fXQuxTpoa7GLJDVrEHBmCn44k62d/PAD/crmO9O1mDkj8X3eimWJUcE0MlPjKoH/0VWV7oN9jYsY1R/fwiS5DqmKR1LGApfl1B/i2v29PC8vhk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705508111; c=relaxed/simple; bh=jDzObRYwRkapJySKK0oWQtxYQUq2OVssGctw+1duV94=; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID: X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding; b=OTy5/2m4f+xv2yh+ryQzqaccw+hp68wgY/9EtZWhg0sTteIdBN/I5H8GxkpCiLGIA40I3M0jYzKfwCae7O28tf9/HwJdss9yiHHRqeB8Fyp10OeH72/8qRf2SJ8JSmNdgopbTXxe/TBFXdpY5/qnbalzwhh9o76Y37YXfPsuo+0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=maEHAzHm; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="maEHAzHm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CF1BAC43609; Wed, 17 Jan 2024 16:15:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1705508110; bh=jDzObRYwRkapJySKK0oWQtxYQUq2OVssGctw+1duV94=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=maEHAzHmX242xFhjDsTXdUbPh+/313gooww6/wGhfud2C6V+ivwG3IIUyyDsblUjI 05Cfc0FLTgiLtets7cdvt9U1BAaDYytmPqjoHp9v4TnGh8hJFgappYvNSadYIZD/lD Ma/df36cpC/lrmGPKu+YGfwmLsCZBQVQEtwaL1F7tdtCu8EBEZBhvc7RrCn1L8LYwJ fvIikk7HgNpBwTIlWV3cNxJgTC0GW6JTKfU1AfajNo4VedSGPAITaQkqyC23exjI6M Yll3SXrambsT2BAdjL4GzfrmGfa7A3h8IX0XJECuRirErY6rcQYAcJ2Vo4ChBB1lwD Yw7CgleyUXxhg== From: Josh Poimboeuf To: Linus Torvalds , Jeff Layton , Chuck Lever , Shakeel Butt , Roman Gushchin , Johannes Weiner , Michal Hocko Cc: linux-kernel@vger.kernel.org, Jens Axboe , Tejun Heo , Vasily Averin , Michal Koutny , Waiman Long , Muchun Song , Jiri Kosina , cgroups@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH RFC 4/4] mitigations: Add flock cache accounting to 'mitigations=off' Date: Wed, 17 Jan 2024 08:14:46 -0800 Message-ID: <3e803d5aee5dd1f4c738f0de1e839e6cfcb9dc41.1705507931.git.jpoimboe@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Allow flock cache accounting to be disabled with 'mitigations=3Doff', as it fits the profile for that option: trusted user space combined with a performance-impacting mitigation. Also, for consistency with the other CONFIG_MITIGATION_* options, rename CONFIG_FLOCK_ACCOUNTING to CONFIG_MITIGATION_FLOCK_ACCOUNTING. Signed-off-by: Josh Poimboeuf --- Documentation/admin-guide/kernel-parameters.txt | 4 ++++ fs/Kconfig | 2 +- fs/locks.c | 5 +++-- 3 files changed, 8 insertions(+), 3 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentatio= n/admin-guide/kernel-parameters.txt index 24e873351368..b31fe7433b48 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3427,6 +3427,10 @@ ssbd=3Dforce-off [ARM64] tsx_async_abort=3Doff [X86] =20 + Software mitigations: + --------------------- + flock_accounting=3Doff [KNL] + Exceptions: This does not have any effect on kvm.nx_huge_pages when diff --git a/fs/Kconfig b/fs/Kconfig index 591f54a03059..4345b79d3b40 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -129,7 +129,7 @@ config FILE_LOCKING for filesystems like NFS and for the flock() system call. Disabling this option saves about 11k. =20 -config FLOCK_ACCOUNTING +config MITIGATION_FLOCK_ACCOUNTING bool "Enable kernel memory accounting for file locks" if EXPERT depends on FILE_LOCKING default y diff --git a/fs/locks.c b/fs/locks.c index e2799a18c4e8..fd4157ccd504 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -64,6 +64,7 @@ #include #include #include +#include =20 #define CREATE_TRACE_POINTS #include @@ -2905,7 +2906,7 @@ static int __init proc_locks_init(void) fs_initcall(proc_locks_init); #endif =20 -static bool flock_accounting __ro_after_init =3D IS_ENABLED(CONFIG_FLOCK_A= CCOUNTING); +static bool flock_accounting __ro_after_init =3D IS_ENABLED(CONFIG_MITIGAT= ION_FLOCK_ACCOUNTING); =20 static int __init flock_accounting_cmdline(char *str) { @@ -2930,7 +2931,7 @@ static int __init filelock_init(void) int i; slab_flags_t flags =3D SLAB_PANIC; =20 - if (!flock_accounting) + if (mitigations_off() || !flock_accounting) pr_err(FLOCK_ACCOUNTING_MSG); else flags |=3D SLAB_ACCOUNT; --=20 2.43.0