From nobody Fri Dec 19 20:55:24 2025 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 17038E776D6 for ; Mon, 2 Oct 2023 23:15:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237290AbjJBXPJ (ORCPT ); Mon, 2 Oct 2023 19:15:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52388 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237204AbjJBXPG (ORCPT ); Mon, 2 Oct 2023 19:15:06 -0400 Received: from mail-wr1-x430.google.com (mail-wr1-x430.google.com [IPv6:2a00:1450:4864:20::430]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 228B6AD for ; Mon, 2 Oct 2023 16:15:04 -0700 (PDT) Received: by mail-wr1-x430.google.com with SMTP id ffacd0b85a97d-317c3ac7339so355260f8f.0 for ; Mon, 02 Oct 2023 16:15:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1696288502; x=1696893302; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=vQvCLVMfpl1rfMES4jKdwm82L8UOBjNuap0Ti+SzBhc=; b=M+CLVVRy5HwsqvwlOokevjgvepUgwThG5qiKvLLjgD6DgeE0lvwqnB3Uwnbn04and0 5FwsF0wShTTx273cd96s8GM5ipKSoQNtSSWLleeCVEi+nkNqXAS5+Skcbte8QM65fri7 CozNyc2DCzNxLYZC2uztoUiriVNctcjbqvUEIPQSF8LrQiVpZD/grqAQaBMVlZ8pkcYa VMbDr9bjJpGKhPJui+9bnSEhAD/CRyHtYHvTgJxCVZq+6//ibb2+RZHErvAkBnvdDDpM OsUvgL92PtYNz963pxwdEIybG9/0Q6M8vXsx9KiGD04R9j+8vvMmaHeZfIW3pbIOP23U U0Cg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696288502; x=1696893302; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=vQvCLVMfpl1rfMES4jKdwm82L8UOBjNuap0Ti+SzBhc=; b=Wz91v5mZdLiPfpjUaMQ6OO3YcLFO1BBx+q276hxhSVcJ3ayBLOFG4gRZ63uNAE9UTR 1IMbZIhkk6Ngb/XEKYfrsRxDl19VZ0Ssa2+YB531BppAlHzyrCZ+yJk4Sb6MikgmKvgD qoURXuWHQUFamsz+kbhMqvGHbRLuYld8JybKuvAoVjjqnWlZ0VYgAbv6v+UonAE2aaAM gM3Tn/TUaXd0l54rgmo45ZG0qjJ4X+qC3dGTXlXumIoU3VmJ4jn5Vm7+NhP6DHspBXuj 6SaO8xRzYsLZ9m+w6UCGSnvZFJDn2Ou8MSfUS9RQtNN6wwtZiKsWggVOtPrfVMmabC2q QtMQ== X-Gm-Message-State: AOJu0YwTAQD5Ljb1yb48RliWmioVD9xG4yfLfxsYg2rUnIVteh3tUM5f vLvr++qE9AZOvQIYkk0gSH0= X-Google-Smtp-Source: AGHT+IEtd7/2+KG5WHd0cByCIEOQATOBxdbRX+bfexS1IsqnxYU1Maj/cmH3p1/Wp7fgogXQxGevfg== X-Received: by 2002:adf:fc4c:0:b0:31a:d4e1:ea30 with SMTP id e12-20020adffc4c000000b0031ad4e1ea30mr11701566wrs.17.1696288502337; Mon, 02 Oct 2023 16:15:02 -0700 (PDT) Received: from lucifer.home ([2a00:23c5:dc8c:8701:1663:9a35:5a7b:1d76]) by smtp.googlemail.com with ESMTPSA id e31-20020a5d595f000000b0031fbbe347e1sm63860wri.65.2023.10.02.16.15.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Oct 2023 16:15:01 -0700 (PDT) From: Lorenzo Stoakes To: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Catalin Marinas , Will Deacon , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland Cc: Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , Oleg Nesterov , Richard Cochran , Jason Gunthorpe , John Hubbard , Arnd Bergmann , Lorenzo Stoakes , David Hildenbrand Subject: [PATCH v2 2/4] mm/gup: explicitly define and check internal GUP flags, disallow FOLL_TOUCH Date: Tue, 3 Oct 2023 00:14:52 +0100 Message-ID: <971e013dfe20915612ea8b704e801d7aef9a66b6.1696288092.git.lstoakes@gmail.com> X-Mailer: git-send-email 2.42.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Rather than open-coding a list of internal GUP flags in is_valid_gup_args(), define which ones are internal. In addition, explicitly check to see if the user passed in FOLL_TOUCH somehow, as this appears to have been accidentally excluded. Reviewed-by: Arnd Bergmann Reviewed-by: David Hildenbrand Signed-off-by: Lorenzo Stoakes --- mm/gup.c | 5 ++--- mm/internal.h | 3 +++ 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index 2f8a2d89fde1..b21b33d1787e 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -2227,12 +2227,11 @@ static bool is_valid_gup_args(struct page **pages, = int *locked, /* * These flags not allowed to be specified externally to the gup * interfaces: - * - FOLL_PIN/FOLL_TRIED/FOLL_FAST_ONLY are internal only + * - FOLL_TOUCH/FOLL_PIN/FOLL_TRIED/FOLL_FAST_ONLY are internal only * - FOLL_REMOTE is internal only and used on follow_page() * - FOLL_UNLOCKABLE is internal only and used if locked is !NULL */ - if (WARN_ON_ONCE(gup_flags & (FOLL_PIN | FOLL_TRIED | FOLL_UNLOCKABLE | - FOLL_REMOTE | FOLL_FAST_ONLY))) + if (WARN_ON_ONCE(gup_flags & INTERNAL_GUP_FLAGS)) return false; =20 gup_flags |=3D to_set; diff --git a/mm/internal.h b/mm/internal.h index 449891ad7fdb..499016c6b01d 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -1018,6 +1018,9 @@ enum { FOLL_UNLOCKABLE =3D 1 << 21, }; =20 +#define INTERNAL_GUP_FLAGS (FOLL_TOUCH | FOLL_TRIED | FOLL_REMOTE | FOLL_P= IN | \ + FOLL_FAST_ONLY | FOLL_UNLOCKABLE) + /* * Indicates for which pages that are write-protected in the page table, * whether GUP has to trigger unsharing via FAULT_FLAG_UNSHARE such that t= he --=20 2.42.0