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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 885D1C3A5A3 for ; Fri, 30 Aug 2019 07:30:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5581821897 for ; Fri, 30 Aug 2019 07:30:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727936AbfH3Ha0 (ORCPT ); Fri, 30 Aug 2019 03:30:26 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:45148 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726655AbfH3Ha0 (ORCPT ); Fri, 30 Aug 2019 03:30:26 -0400 Received: from 162-237-133-238.lightspeed.rcsntx.sbcglobal.net ([162.237.133.238] helo=elm) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1i3bMV-0000hq-Ga; Fri, 30 Aug 2019 07:30:23 +0000 Date: Fri, 30 Aug 2019 02:30:19 -0500 From: Tyler Hicks To: Greg Kroah-Hartman Cc: Sasha Levin , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Todd Kjos , devel@driverdev.osuosl.org Subject: Re: [PATCH AUTOSEL 4.19 11/29] binder: take read mode of mmap_sem in binder_alloc_free_page() Message-ID: <20190830073019.GA16891@elm> References: <20190829105009.2265-1-sashal@kernel.org> <20190829105009.2265-11-sashal@kernel.org> <20190829151320.GC27650@elm> <20190830062910.GC15257@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190830062910.GC15257@kroah.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On 2019-08-30 08:29:10, Greg Kroah-Hartman wrote: > On Thu, Aug 29, 2019 at 10:13:20AM -0500, Tyler Hicks wrote: > > Hello, Sasha! > > > > On 2019-08-29 06:49:51, Sasha Levin wrote: > > > From: Tyler Hicks > > > > > > [ Upstream commit 60d4885710836595192c42d3e04b27551d30ec91 ] > > > > > > Restore the behavior of locking mmap_sem for reading in > > > binder_alloc_free_page(), as was first done in commit 3013bf62b67a > > > ("binder: reduce mmap_sem write-side lock"). That change was > > > inadvertently reverted by commit 5cec2d2e5839 ("binder: fix race between > > > munmap() and direct reclaim"). > > > > > > In addition, change the name of the label for the error path to > > > accurately reflect that we're taking the lock for reading. > > > > > > Backporting note: This fix is only needed when *both* of the commits > > > mentioned above are applied. That's an unlikely situation since they > > > both landed during the development of v5.1 but only one of them is > > > targeted for stable. > > > > This patch isn't meant to be applied to 4.19 since commit 3013bf62b67a > > ("binder: reduce mmap_sem write-side lock") was never brought back to > > 4.19. > > > > Tyler > > > > > > > > Fixes: 5cec2d2e5839 ("binder: fix race between munmap() and direct reclaim") > > But this commit is in 4.19.49 That's correct but commit 3013bf62b67a isn't present in 4.19.y. See the "Backporting note" above. Tyler > > thanks, > > greg k-h