From nobody Wed Oct 1 22:34:49 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 87ECB34BA5A for ; Mon, 29 Sep 2025 15:55:14 +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=1759161317; cv=none; b=gibEk1I3VCdkaYEmzc6R4dj7nRIUjFAyWn1cXtnXXDNNTtP0/LmGPdXtC4NpKDXGk9xiORPyhbGMqtOubtiYMGQVpjaiUFrKsL4kS2FShfSltRFw98TzswH738eb7j6AGgekTDeUJk2NaFxJNGFaYzdF1t1sS1IjZH0mUPO/kTk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759161317; c=relaxed/simple; bh=5ZiYViMmHyYTGbotSTQoJNHs5BRuX6SdoxN8p8nXJh0=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=kq8xf65a+XSvFIa8JNGCIkmYmY8BDNsPK55sJMPi5e7cP1T7+eTI9f6s+M2XgRLMzeZK8rsOCNMpr0C9qU7UQANVZVOpF1x2u+N9lnlGlP05F5vf+HG78F2WyG7+d8ZE/qmQsYCkXB2TxB2FSM5BRhJmfmyh4BexmbTdwyk7TuY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SKc62zVt; 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="SKc62zVt" Received: by smtp.kernel.org (Postfix) with ESMTPS id 250CBC4CEF4; Mon, 29 Sep 2025 15:55:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1759161314; bh=5ZiYViMmHyYTGbotSTQoJNHs5BRuX6SdoxN8p8nXJh0=; h=From:Date:Subject:To:Cc:From; b=SKc62zVtn00Uk5vk3CA+EXf9fSGP6vPqQA32v4D/dWzgk2RFFeNtX0bU24zWlhcug tpDVDDdQ9jpw1MfHqiFTJajPbdM1iHKCTkq5bYO2D3fXyvBOp8D3iGEdfNY7uaLECr 6zvuxpTfR4JewwSet9kfEFiCjCeNJ9qr60inA4HIqu5SMbjxcsXnaFX2gQ+wwRRdfT yXS6XCmnL8d+aGe5tG2Nr+rO7GD8GkSvC84Pt8pMP4D83VNp+ZurwfFTwDnZcn1oBk wO0WatAMmhex5sul7LemGM3f2so47JZZ/7EIw/X9o0fDvVkaCgXUpp17KBaV/GL7zD sN+LcvKRSz9/Q== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0CECACAC5B0; Mon, 29 Sep 2025 15:55:14 +0000 (UTC) From: Joel Granados Date: Mon, 29 Sep 2025 17:55:07 +0200 Subject: [PATCH] watchdog: move nmi_watchdog sysctl into .rodata Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250929-jag-nmiwd_const-v1-1-92200d503b1f@kernel.org> X-B4-Tracking: v=1; b=H4sIANqr2mgC/6tWKk4tykwtVrJSqFYqSi3LLM7MzwNyDHUUlJIzE vPSU3UzU4B8JSMDI1MDSyNL3azEdN283MzylPjk/LziEt0UcxMj48QkI1MTSzMloK6CotS0zAq widGxtbUAqzFcmmEAAAA= X-Change-ID: 20250929-jag-nmiwd_const-d7423ab25496 To: Petr Mladek , Daniel Xu Cc: linux-kernel@vger.kernel.org, Joel Granados X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=2198; i=joel.granados@kernel.org; h=from:subject:message-id; bh=5ZiYViMmHyYTGbotSTQoJNHs5BRuX6SdoxN8p8nXJh0=; b=owJ4nAHtARL+kA0DAAoBupfNUreWQU8ByyZiAGjaq+COM2Svc8jNNFjm5q85lI9TkhtAfjlfy 8z8sh5u2LRDLokBswQAAQoAHRYhBK5HCVcl5jElzssnkLqXzVK3lkFPBQJo2qvgAAoJELqXzVK3 lkFPzlAL/3fhRZbC1qSPUyUYd6UjCH1DU3lx6hp+FzCodX/p2mgTY/luqaOVtuTMqewvQVAJ4dV RbrlwckF82kME1qIKhRyrdZrlIGxNwoe6wMf7Ji58iV0YKQXLySYW/Q44x5byReySl6ONNJ1fvR 3KFPTGU3FQKR8tYayZjjVQyUa/U0B2NyvoPfPJJoqnTo0fXcZTbWdldXDrloJ/HBaip9agWMrgk slAItrraZlt3emPeLB0BslyyaClokokTiB4hwq9iaJhLBTtPF/r0E/UQ3nu21DSIRe9z9+HCuuP 3gPD5+XdsN6Xk0ZKJYivG+5NlHFSa4utglLilzdyiUGvRy9NQAprx/I/8X+Po0cZgfUxEvGaHmA 0oW/14sZzvzR0WBb6qAIacHvUF2cKkhXohfFxYPrsiK4zH7oc10HM5pctdsLOogMS47+raE+NqC ktzJ4mcOjjaTZtKO+Q3mjb3eRdqXoAXabOVJIRQlugNiUI8PpGIWrfZTKqxiV7yLcXYqqu+MIt7 eU= X-Developer-Key: i=joel.granados@kernel.org; a=openpgp; fpr=F1F8E46D30F0F6C4A45FF4465895FAAC338C6E77 X-Endpoint-Received: by B4 Relay for joel.granados@kernel.org/default with auth_id=239 Move nmi_watchdog into the watchdog_sysctls array to prevent it from unnecessary modification. This move effectively moves it inside the .rodata section. Initially moved out into its own non-const array in commit 9ec272c586b0 ("watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails"), which made it writable only when watchdog_hardlockup_available was true. Moving it back to watchdog_sysctl keeps this behavior as writing to nmi_watchdog still fails when watchdog_hardlockup_available is false. Signed-off-by: Joel Granados --- This patch is a followup on the discussion/question I had in [1]. I would prefer this to be const as it locks things in .rodata and prevents inadvertent modifications [2]. [1] https://lore.kernel.org/all/588ec9ab-b38a-40b3-8db5-575a09e9a126@meta.c= om/ [2] https://lore.kernel.org/all/20250109-jag-ctl_table_const-v1-1-622aea723= 0cf@kernel.org/ --- kernel/watchdog.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 80b56c002c7f123c49f65465fe7af9c74de4f46a..1e4e3eccb065a5ce95486f24fa0= 7387e8218cd62 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -1213,14 +1213,11 @@ static const struct ctl_table watchdog_sysctls[] = =3D { }, #endif /* CONFIG_SMP */ #endif -}; - -static struct ctl_table watchdog_hardlockup_sysctl[] =3D { { .procname =3D "nmi_watchdog", .data =3D &watchdog_hardlockup_user_enabled, .maxlen =3D sizeof(int), - .mode =3D 0444, + .mode =3D 0644, .proc_handler =3D proc_nmi_watchdog, .extra1 =3D SYSCTL_ZERO, .extra2 =3D SYSCTL_ONE, @@ -1230,10 +1227,6 @@ static struct ctl_table watchdog_hardlockup_sysctl[]= =3D { static void __init watchdog_sysctl_init(void) { register_sysctl_init("kernel", watchdog_sysctls); - - if (watchdog_hardlockup_available) - watchdog_hardlockup_sysctl[0].mode =3D 0644; - register_sysctl_init("kernel", watchdog_hardlockup_sysctl); } =20 #else --- base-commit: e5f0a698b34ed76002dc5cff3804a61c80233a7a change-id: 20250929-jag-nmiwd_const-d7423ab25496 Best regards, --=20 Joel Granados