From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Mon, 24 Sep 2018 13:00:29 +0200 (CEST) Received: from out1-smtp.messagingengine.com ([66.111.4.25]:59663 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S23992066AbeIXLAY4LsuU (ORCPT ); Mon, 24 Sep 2018 13:00:24 +0200 Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailout.nyi.internal (Postfix) with ESMTP id DA01D21A7B; Mon, 24 Sep 2018 07:00:23 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute6.internal (MEProxy); Mon, 24 Sep 2018 07:00:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kroah.com; h=cc :content-type:date:from:in-reply-to:message-id:mime-version :references:subject:to:x-me-sender:x-me-sender:x-sasl-enc; s= fm1; bh=+3Zq1T085IioVZUG6ygk2FVuGAGypzfDUMvE/zb+64k=; b=PVnNhusD z3Wu6ADcNVDXSQiz88+bAj0mmDqVjgxxztFGS+HHz++hdqQJk5z6/LfJuHmtJgge loH9O3Zne+4a3BOqwZ6yezriVEc9jyrpIgSQrpyzvEK6WNeaJy90wXNdNLRaHfyO AHkRWJyFuavbqUEKfIEv3BohaQ9+0ZLD8B1Z9OqNkdYklzG3cu4oH8A/j1HiC/F3 FRxK3lrbJspl6OElJ92KfhlenAZ+B6RpqRjmW9He0mP9/PiANjmQaZFslak/njA9 21PBfkJQF0j/xqbCopuHXq2lpsNuxWzxUCJ+zA2gpfsaeSEAzu4r1/y64R000Vwu eRAwWxPOFoGQlQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-sender :x-me-sender:x-sasl-enc; s=fm3; bh=+3Zq1T085IioVZUG6ygk2FVuGAGyp zfDUMvE/zb+64k=; b=uY1eNbWhc6RMxPuWf2vmk2GnbkJZlr2V4lsohMKgDFvWx 9qYKAbv6yggyEl0doECF8fkJ3W3RYd11DQ2rC7UG2EVXzXDvWvKrsJ6n2ULgrPBK oZjeljhwa2SGwSK7IqA6kNMRw3XmgWi4IfS69YqxbCbKdYONAuVV9I3xlVi7Q3iF 0tPwuztF28XwbctioqbsDg1P3KhHciqp5SLD6N85056pfSyoCdBwnnzmgr5ZBLgh rwFmh7bZ2IO6BQi+FuvEeeiDync5vy9bd6KlTtaZMnhuDu6Idq2hRHtbTfJhRFyH cau0A9AQfBpPPcmPGGAcwMhJciCxpDrNHVWdeqnTw== X-ME-Proxy: X-ME-Sender: Received: from localhost (ip-213-127-77-73.ip.prioritytelecom.net [213.127.77.73]) by mail.messagingengine.com (Postfix) with ESMTPA id 8C958102D2; Mon, 24 Sep 2018 07:00:22 -0400 (EDT) Date: Mon, 24 Sep 2018 13:00:21 +0200 From: Greg KH To: Paul Burton Cc: "stable@vger.kernel.org" , "linux-mips@linux-mips.org" , Hauke Mehrtens , Rene Nielsen , Alexandre Belloni , Paul Burton , James Hogan Subject: Re: [PATCH 4.4] MIPS: VDSO: Match data page cache colouring when D$ aliases Message-ID: <20180924110021.GH16476@kroah.com> References: <20180919212044.21385-1-paul.burton@mips.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180919212044.21385-1-paul.burton@mips.com> User-Agent: Mutt/1.10.1 (2018-07-13) Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 66514 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: greg@kroah.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips On Wed, Sep 19, 2018 at 09:20:59PM +0000, Paul Burton wrote: > [ Upstream commit 0f02cfbc3d9e413d450d8d0fd660077c23f67eff ] > > When a system suffers from dcache aliasing a user program may observe > stale VDSO data from an aliased cache line. Notably this can break the > expectation that clock_gettime(CLOCK_MONOTONIC, ...) is, as its name > suggests, monotonic. > > In order to ensure that users observe updates to the VDSO data page as > intended, align the user mappings of the VDSO data page such that their > cache colouring matches that of the virtual address range which the > kernel will use to update the data page - typically its unmapped address > within kseg0. > > This ensures that we don't introduce aliasing cache lines for the VDSO > data page, and therefore that userland will observe updates without > requiring cache invalidation. > > Signed-off-by: Paul Burton > Reported-by: Hauke Mehrtens > Reported-by: Rene Nielsen > Reported-by: Alexandre Belloni > Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO") > Patchwork: https://patchwork.linux-mips.org/patch/20344/ > Tested-by: Alexandre Belloni > Tested-by: Hauke Mehrtens > Cc: James Hogan > Cc: linux-mips@linux-mips.org > Cc: stable@vger.kernel.org # v4.4+ > --- > arch/mips/kernel/vdso.c | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) This, and the 4.9.y backport, are now applied, thanks. greg k-h