From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9CD77C433FE for ; Wed, 22 Dec 2021 12:54:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244986AbhLVMyO (ORCPT ); Wed, 22 Dec 2021 07:54:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40844 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233901AbhLVMyK (ORCPT ); Wed, 22 Dec 2021 07:54:10 -0500 Received: from mail-wm1-x334.google.com (mail-wm1-x334.google.com [IPv6:2a00:1450:4864:20::334]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4915FC061574; Wed, 22 Dec 2021 04:54:10 -0800 (PST) Received: by mail-wm1-x334.google.com with SMTP id e5so1124851wmq.1; Wed, 22 Dec 2021 04:54:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id; bh=Ry2r1h/5gPEfjPNAeB20WCeNaM662aOvZ4e55tHa4OA=; b=Of03S8B1wQYuhMUfs+mIklxnKsQtHZGPNn+H8z9lAO9iw/tp2DOrPhOKzlYf0U4gGJ Q64WLhmin2tcdDkgCgitkeScLf3ca5y1z1hfnsmjNj+EFc9gY+by2xKUR8VgAqwdrMwn 4WyGaBEjxRF6zTbhC+nEWldYHZM6waRZwzeuiwaD8sAySOsdaN04jFWFf188QOP5XlYW Ra8KzPqD3XmNlt1SIwW4uhRNyt3psKWM3sU7MlBNbMg3/919CBEbLBNC8c99yk+sE6uJ 6XLjyKNVvCqdLxx9bhby6PdGJsJlOXE2z3xWT8QBr6cxczWvMFbmixx+tlQZTZQpw9IJ dVAQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=Ry2r1h/5gPEfjPNAeB20WCeNaM662aOvZ4e55tHa4OA=; b=bnFL5xdoeGZkyo9nYZ1QwDBlytkWYHfI4UEEMjiuog4IYP7OACkKA6OMh1LMwd74EP I7eLMLCVR8x4CBrLN6ucr/kUyZ7T+OjagQpevR3N6Mc0Fx7G5uJygorEI6eXk0ddC6pS zaZbF6ktEU23xz80xv/Oe624nw5MkNZLI6dt88Q6JdzmdMxbrojMDlHhtfedeQ3iQQul 2sd4LPch1QV0Q7gmk2HTPGJerPwiPZXXTDmdxJuRpdM+R1Gwobs2tVKpsQT9VS2WIDoc m43yVvCuvfL3BMiqigg2bfSCXQNfeG5I93Z17VVWL2OOyaYCpcKxv1jRScV+Kv27jKfk k8Vg== X-Gm-Message-State: AOAM531v7fYmPkG0MIaSyUIPffHOwuGP5Zy7aCjRgKHKfvu8WJ+RYFyC ey57EnfNmLoKd1vsiMy/cuc= X-Google-Smtp-Source: ABdhPJzprnj332k4bcwegE0DW9KLNfliUp/i1yMiDyUr51Ly928Q/8w1laehjVuOpszZf0NxLPt4TA== X-Received: by 2002:a05:600c:4fcd:: with SMTP id o13mr852886wmq.175.1640177648679; Wed, 22 Dec 2021 04:54:08 -0800 (PST) Received: from felia.fritz.box ([2001:16b8:26d4:3a00:1de2:a01a:60c3:26d5]) by smtp.gmail.com with ESMTPSA id v1sm2102249wru.45.2021.12.22.04.54.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 22 Dec 2021 04:54:08 -0800 (PST) From: Lukas Bulwahn To: Dave Hansen , Kees Cook Cc: Andy Lutomirski , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H . Peter Anvin" , kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org, Lukas Bulwahn Subject: [PATCH] x86: mm: refer to the intended config STRICT_DEVMEM in a comment Date: Wed, 22 Dec 2021 13:53:47 +0100 Message-Id: <20211222125347.13054-1-lukas.bulwahn@gmail.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit a4866aa81251 ("mm: Tighten x86 /dev/mem with zeroing reads") adds a comment to the function devmem_is_allowed() referring to a non-existing config STRICT_IOMEM, whereas the comment very likely intended to refer to the config STRICT_DEVMEM, as the commit adds some behavior for the config STRICT_DEVMEM. Most of the initial analysis was actually done by Dave Hansen in the email thread below (see Link). Refer to the intended and existing config STRICT_DEVMEM. Link: https://lore.kernel.org/r/f9074e8d-9314-9d7d-7bf5-5b5538c8be8d@intel.com/ Suggested-by: Dave Hansen Signed-off-by: Lukas Bulwahn --- arch/x86/mm/init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 4ba024d5b63a..64ac8a5e928a 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -847,7 +847,7 @@ int devmem_is_allowed(unsigned long pagenr) /* * This must follow RAM test, since System RAM is considered a - * restricted resource under CONFIG_STRICT_IOMEM. + * restricted resource under CONFIG_STRICT_DEVMEM. */ if (iomem_is_exclusive(pagenr << PAGE_SHIFT)) { /* Low 1MB bypasses iomem restrictions. */ -- 2.17.1