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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 EC31CC3A5A6 for ; Fri, 30 Aug 2019 06:29:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B2F1820659 for ; Fri, 30 Aug 2019 06:29:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567146555; bh=w5gHXGlwtkw2+r0MPL+BJkXamsnvdtNRlH2XT0EHQjQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=R0zZvtaDVAsCTloW/8kFbaKiRZTbYCdubjOHIcrLn4td9v/ikWx84i4ZlahEvdvRf nbcSARZhIBweFcwQJ7V47uwpfNmTW493rtBCf1a9lFqQhLaDpnWvIjNJh7+huwscgM 5FJvDIeryCiUvfgd/AiaMcUmxkJUNmscRNyK8X64= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727924AbfH3G3O (ORCPT ); Fri, 30 Aug 2019 02:29:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:60738 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726144AbfH3G3O (ORCPT ); Fri, 30 Aug 2019 02:29:14 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 A88F120659; Fri, 30 Aug 2019 06:29:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567146553; bh=w5gHXGlwtkw2+r0MPL+BJkXamsnvdtNRlH2XT0EHQjQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Zl/htVkwO8o8kRP/crnxSsKBzqX5r1VOcAf2+9z2mTsgV1h127OaVZ+P5pSJgFC4a 1EjiRvpMeXynfXXQUneSP3UVBl4zFlWzbWlH9RFnc57ehE5WHYYhlyetYUGVNDCw0+ vAqlhZHwR9xUo18lZSBQuCV8+NA2wh4UTgYe7Dyw= Date: Fri, 30 Aug 2019 08:29:10 +0200 From: Greg Kroah-Hartman To: Tyler Hicks 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: <20190830062910.GC15257@kroah.com> References: <20190829105009.2265-1-sashal@kernel.org> <20190829105009.2265-11-sashal@kernel.org> <20190829151320.GC27650@elm> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190829151320.GC27650@elm> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 thanks, greg k-h