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 X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 678AAC2BBCA for ; Wed, 16 Dec 2020 04:47:37 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 06C6D23332 for ; Wed, 16 Dec 2020 04:47:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 06C6D23332 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 911CC6B00AC; Tue, 15 Dec 2020 23:47:36 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 89B956B00AD; Tue, 15 Dec 2020 23:47:36 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 78C8A8D0001; Tue, 15 Dec 2020 23:47:36 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0006.hostedemail.com [216.40.44.6]) by kanga.kvack.org (Postfix) with ESMTP id 5D0DE6B00AC for ; Tue, 15 Dec 2020 23:47:36 -0500 (EST) Received: from smtpin05.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 2B68D181AEF1E for ; Wed, 16 Dec 2020 04:47:36 +0000 (UTC) X-FDA: 77597912112.05.air24_2a14efc27429 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin05.hostedemail.com (Postfix) with ESMTP id 12D161801B5FA for ; Wed, 16 Dec 2020 04:47:36 +0000 (UTC) X-HE-Tag: air24_2a14efc27429 X-Filterd-Recvd-Size: 2569 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf20.hostedemail.com (Postfix) with ESMTP for ; Wed, 16 Dec 2020 04:47:35 +0000 (UTC) Date: Tue, 15 Dec 2020 20:47:33 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1608094054; bh=462ioZ5uCjZTZ0Xw3Hrqpy1AQpYq0q/FTY4isv+IMYA=; h=From:To:Subject:In-Reply-To:From; b=H58pfWEhfsI+TFpbZkTAA3OmxIz8NDGm/A+Yk1wmPbWyZcPBoiKIu8QpvyjzZrayG J9pWBls0f6XYmOIRAYnCtH6FTehx18bwaDSjt1gBkzV9DBxbs1fvafXA/m+SyAjX0w dQaJup6FyzmLwxmdtf1QpVOMJStFvYUD1u4Nrzpo= From: Andrew Morton To: akpm@linux-foundation.org, ebiederm@xmission.com, jannh@google.com, jgg@nvidia.com, jhubbard@nvidia.com, linux-mm@kvack.org, mchehab@kernel.org, mm-commits@vger.kernel.org, sakari.ailus@linux.intel.com, torvalds@linux-foundation.org, walken@google.com Subject: [patch 95/95] mm/gup: assert that the mmap lock is held in __get_user_pages() Message-ID: <20201216044733.ICgCxdEoF%akpm@linux-foundation.org> In-Reply-To: <20201215204156.f05ec694b907845bcfab5c44@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Jann Horn Subject: mm/gup: assert that the mmap lock is held in __get_user_pages() After having cleaned up all GUP callers (except for the atomisp staging driver, which currently gets mmap locking completely wrong [1]) to always ensure that they hold the mmap lock when calling into GUP (unless the mm is not yet globally visible), add an assertion to make sure it stays that way going forward. [1] https://lore.kernel.org/lkml/CAG48ez3tZAb9JVhw4T5e-i=h2_DUZxfNRTDsagSRCVazNXx5qA@mail.gmail.com/ Link: https://lkml.kernel.org/r/CAG48ez1GM==OnHpS=ghqZNJPn02FCDUEHc7GQmGRMXUD_aKudg@mail.gmail.com Signed-off-by: Jann Horn Reviewed-by: Jason Gunthorpe Acked-by: Michel Lespinasse Cc: "Eric W . Biederman" Cc: John Hubbard Cc: Mauro Carvalho Chehab Cc: Sakari Ailus Signed-off-by: Andrew Morton --- mm/gup.c | 2 ++ 1 file changed, 2 insertions(+) --- a/mm/gup.c~mm-gup-assert-that-the-mmap-lock-is-held-in-__get_user_pages +++ a/mm/gup.c @@ -996,6 +996,8 @@ static long __get_user_pages(struct mm_s struct vm_area_struct *vma = NULL; struct follow_page_context ctx = { NULL }; + mmap_assert_locked(mm); + if (!nr_pages) return 0; _