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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 783EACA9ED2 for ; Sat, 2 Nov 2019 19:34:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5330F21783 for ; Sat, 2 Nov 2019 19:34:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="gAoDpQwZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726687AbfKBTep (ORCPT ); Sat, 2 Nov 2019 15:34:45 -0400 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:33911 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726757AbfKBTen (ORCPT ); Sat, 2 Nov 2019 15:34:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1572723282; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=n9uy9Ir3Ut1yjzdM3qEpE4Hb5gck/P7uGMy2spM/hGs=; b=gAoDpQwZG4XmAzvZSPh32H1ilDY+7nyAZa0E5EPt/qqoDYyben+F/MQ5dV9XzkXYX6Jd1I eCh6pb+2UwYN9hvnC9otbxNsd2sAMmeRmbQyGazvoRMe1nnp6lYZ9tueKJtUDcpUsa9Coq 4IiE8g3MAaa3AIF5yAvV2/9BnHhXGpg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-430-oDDOJjWoN7W39XjMblURzQ-1; Sat, 02 Nov 2019 15:34:39 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 977298017E0; Sat, 2 Nov 2019 19:34:36 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-121-40.rdu2.redhat.com [10.10.121.40]) by smtp.corp.redhat.com (Postfix) with ESMTP id EDFB85D9E2; Sat, 2 Nov 2019 19:34:32 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: <157186182463.3995.13922458878706311997.stgit@warthog.procyon.org.uk> <30394.1571936252@warthog.procyon.org.uk> <17311.1572534953@warthog.procyon.org.uk> To: Linus Torvalds Cc: dhowells@redhat.com, Konstantin Khlebnikov , Rasmus Villemoes , Greg Kroah-Hartman , Peter Zijlstra , Nicolas Dichtel , raven@themaw.net, Christian Brauner , keyrings@vger.kernel.org, linux-usb@vger.kernel.org, linux-block , LSM List , linux-fsdevel , Linux API , Linux Kernel Mailing List Subject: Re: [RFC PATCH 11/10] pipe: Add fsync() support [ver #2] MIME-Version: 1.0 Content-ID: <25885.1572723272.1@warthog.procyon.org.uk> Date: Sat, 02 Nov 2019 19:34:32 +0000 Message-ID: <25886.1572723272@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-MC-Unique: oDDOJjWoN7W39XjMblURzQ-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: Linus Torvalds wrote: > > > Similar synchronization is required for reusing memory after vmsplice= ()? > > > I don't see other way how sender could safely change these pages. Actually, it's probably worse than that. If the output of the pipe gets te= ed or spliced somewhere else, you still don't know when the vmspliced pages ar= e finished with. David