From patchwork Wed Jun 3 22:56:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 11586341 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8C38B14E3 for ; Wed, 3 Jun 2020 22:56:44 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4F6BA20659 for ; Wed, 3 Jun 2020 22:56:44 +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 4F6BA20659 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) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 3AA5A280003; Wed, 3 Jun 2020 18:56:43 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org 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-Original-To: linux-mm@kvack.org 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-Spam-Summary: 2,0,0,5a2586408a215dd1,d41d8cd98f00b204,akpm@linux-foundation.org,,RULES_HIT:41:355:379:800:960:967:973:988:989:1260:1263:1345:1359:1381:1431:1437:1534:1541:1711:1730:1747:1777:1792:2393:2525:2559:2563:2682:2685:2859:2902:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3352:3865:3866:3867:3870:3874:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4321:4605:5007:6261:6653:7576:8599:8660:9025:9545:10004:10913:11026:11473:11658:11914:12043:12048:12114:12297:12438:12517:12519:12555:12679:12783:12986:13069:13148:13230:13311:13357:13846:14181:14384:14721:14849:21080:21451:21627:21939:21990:30054:30064,0,RBL:198.145.29.99:@linux-foundation.org:.lbl8.mailshell.net-64.100.201.201 62.2.0.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:23,LUA_SUMMARY:none 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;