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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 02D9AC28CC0 for ; Thu, 30 May 2019 18:28:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DCF1325FAE for ; Thu, 30 May 2019 18:28:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726518AbfE3S2m (ORCPT ); Thu, 30 May 2019 14:28:42 -0400 Received: from mail-qt1-f196.google.com ([209.85.160.196]:33904 "EHLO mail-qt1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726079AbfE3S2m (ORCPT ); Thu, 30 May 2019 14:28:42 -0400 Received: by mail-qt1-f196.google.com with SMTP id h1so8228571qtp.1; Thu, 30 May 2019 11:28:41 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=y/lAesORefc6bhlBeQ2Gn091+SjcoN/8Ir1iuEsW99A=; b=QhzkmGMypMm9pHr7YV2l2l3kwhSgGYYTPo9Ui6fbzivhiUmeUEkLQ+vWUflEDcxswU oA0/XS7gEIH+kWhfS5fMV/BCdkBLwHz3vTTiJtRN99dVRlesKrkmqCkexsucoxBoZFoE oCmzavHc9QEHTQaJ69U3obalRJYxv70kjk+dPlYQ95ddEcJWesAwE8TZMscNVoYhsRHi b9MKVDvFmLuXmU3CoBjklRpQSAfg6YQgPXQ2w7723BT44YUz2eAtlzz81JAL027vcA3X qbFYtb2Ik54tPoS3BdPn8ql5ZmfF5t3yxzr3ZMqZYB6oPkLy7WhW0RlAgKm3jK7njIm6 f6Vg== X-Gm-Message-State: APjAAAWFz66nDB82toN9GYf+rVzYGpUKEH5O/wPHkVTxjyppzcFnMoLt YbzTcybHjqhqlC6bvformNebIY/+n60nujpxPuA= X-Google-Smtp-Source: APXvYqwJZtIYaMrmM7kBP31g8e8y4dFZ6guBPLQBIpcazgz32TcKxbacQZ3BiQaq4nHfJv7EzcWESGiPWz6vCSB3pMY= X-Received: by 2002:ac8:2433:: with SMTP id c48mr4854798qtc.18.1559240921162; Thu, 30 May 2019 11:28:41 -0700 (PDT) MIME-Version: 1.0 References: <20190522032144.10995-1-deepa.kernel@gmail.com> <20190529161157.GA27659@redhat.com> <874l5czozi.fsf@xmission.com> In-Reply-To: <874l5czozi.fsf@xmission.com> From: Arnd Bergmann Date: Thu, 30 May 2019 20:28:24 +0200 Message-ID: Subject: Re: pselect/etc semantics To: "Eric W. Biederman" Cc: Oleg Nesterov , Deepa Dinamani , Al Viro , Linus Torvalds , Linux Kernel Mailing List , Andrew Morton , dbueso@suse.de, Jens Axboe , Davidlohr Bueso , e@80x24.org, Jason Baron , Linux FS-devel Mailing List , linux-aio , omar.kilani@gmail.com, Thomas Gleixner , "# 3.4.x" Content-Type: text/plain; charset="UTF-8" Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Thu, May 30, 2019 at 3:54 AM Eric W. Biederman wrote: > Arnd Bergmann writes: > > On Wed, May 29, 2019 at 6:12 PM Oleg Nesterov wrote: > > > > Not sure about the order of the cleanups, but probably something like > > this would work: > > > > 1. fix the race (to be backported) > > 2. unify set_compat_user_sigmask/set_user_sigmask > > 3. remove unneeded compat handlers > > 4. replace restore_user_sigmask with restore_saved_sigmask_if() > > 5. also unify compat_get_fd_set()/get_fd_set() and kill off > > compat select() variants. > > Are new system calls added preventing a revert of the patch in question > for stable kernels? Yes, a straight revert would not work, as it was done as a cleanup in order to simplify the following conversion. I suppose one could undo the cleanup in both the time32 and time64 versions of each syscall, but I would consider that a more risky change than just fixing the bug that was reported. Arnd