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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 E2B7FC433E0 for ; Wed, 3 Jun 2020 22:56:43 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A026520659 for ; Wed, 3 Jun 2020 22:56:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="V09WmwK9" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A026520659 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 42018280008; Wed, 3 Jun 2020 18:56:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3AA5A280003; Wed, 3 Jun 2020 18:56:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 27204280008; Wed, 3 Jun 2020 18:56:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0026.hostedemail.com [216.40.44.26]) by kanga.kvack.org (Postfix) with ESMTP id 0ADC2280003 for ; Wed, 3 Jun 2020 18:56:43 -0400 (EDT) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id BDECF8248D51 for ; Wed, 3 Jun 2020 22:56:42 +0000 (UTC) X-FDA: 76889411844.13.skate63_5001b33eb5f Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin13.hostedemail.com (Postfix) with ESMTP id A156418140B60 for ; Wed, 3 Jun 2020 22:56:42 +0000 (UTC) X-HE-Tag: skate63_5001b33eb5f X-Filterd-Recvd-Size: 2606 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf01.hostedemail.com (Postfix) with ESMTP for ; Wed, 3 Jun 2020 22:56:42 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F0184207D0; Wed, 3 Jun 2020 22:56:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591225001; bh=wbKlm0n6lSzWdml/5Hlb4rVc0eecmYfCqol+a/VCQnk=; h=Date:From:To:Subject:In-Reply-To:From; b=V09WmwK9XnPA0BrFYRjsnOuGnl0kfBa/j5U0upjsqQOYxrTdVk1WPlZYpoMhsuPmB iJ6mCn/RSY9vC5DF3v1VJF8aXObB/jM1RILKwvOJa2ncDfH+Armfnxpj/x0uvx8/w2 sl0SxYjSpbHV+nGdVToYTBdq2vdmBGyzaGrerWOw= Date: Wed, 03 Jun 2020 15:56:40 -0700 From: Andrew Morton To: akpm@linux-foundation.org, jgg@ziepe.ca, jhubbard@nvidia.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, walken@google.com, willy@infradead.org Subject: [patch 007/131] mm/gup: might_lock_read(mmap_sem) in get_user_pages_fast() Message-ID: <20200603225640.p1jX5JqMA%akpm@linux-foundation.org> In-Reply-To: <20200603155549.e041363450869eaae4c7f05b@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Rspamd-Queue-Id: A156418140B60 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam05 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: John Hubbard Subject: mm/gup: might_lock_read(mmap_sem) in get_user_pages_fast() Instead of scattering these assertions across the drivers, do this assertion inside the core of get_user_pages_fast*() functions. That also includes pin_user_pages_fast*() routines. Add a might_lock_read(mmap_sem) call to internal_get_user_pages_fast(). Link: http://lkml.kernel.org/r/20200522010443.1290485-1-jhubbard@nvidia.com Signed-off-by: John Hubbard Suggested-by: Matthew Wilcox Reviewed-by: Matthew Wilcox Cc: Michel Lespinasse Cc: Jason Gunthorpe Signed-off-by: Andrew Morton --- mm/gup.c | 3 +++ 1 file changed, 3 insertions(+) --- a/mm/gup.c~mm-gup-might_lock_readmmap_sem-in-get_user_pages_fast +++ a/mm/gup.c @@ -2739,6 +2739,9 @@ static int internal_get_user_pages_fast( FOLL_FAST_ONLY))) return -EINVAL; + if (!(gup_flags & FOLL_FAST_ONLY)) + might_lock_read(¤t->mm->mmap_sem); + start = untagged_addr(start) & PAGE_MASK; addr = start; len = (unsigned long) nr_pages << PAGE_SHIFT; _