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=-7.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 110DFC433E4 for ; Fri, 7 Aug 2020 13:14:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E00392224D for ; Fri, 7 Aug 2020 13:14:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596806065; bh=FtlvdFU0rYHu3NtmhLjOvAgzY9+CtYRM9ziRa0ODO0A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=LW9HXLn2GAsaEwepU/bCI83CFOb2f/5mCVV70Y8XzrPM9ostNh9G1P3JoHTCmznZq 54t1UgSRjFUPuiWE0TwYLqOfX6vRL2FyxvNNUH++l05/JgiIvtcalVgGDgpzkFTn/B 7Ea/4kRuWT/E86/gruADlusKhFmtTfP4ysj+lakY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726764AbgHGNOY (ORCPT ); Fri, 7 Aug 2020 09:14:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:60724 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726710AbgHGNOR (ORCPT ); Fri, 7 Aug 2020 09:14:17 -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 7D31C22C9F; Fri, 7 Aug 2020 13:14:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596806056; bh=FtlvdFU0rYHu3NtmhLjOvAgzY9+CtYRM9ziRa0ODO0A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=gmZIGCEcgfuVdz+6J2O7xd/KbPIF8Kt0i6lVH1/0GwDcP4ahviudYfWt2hAY9j7B+ aWdmlsXly326kOqV/BPhToRn3VR8LfDF+AQAJNY0pdH7uq8FP5GpGuc8TV3OPPvqvs KY2003KRA8He4FRGu9xn2B11aFr5mnbTQA8dFXSc= Date: Fri, 7 Aug 2020 15:14:29 +0200 From: Greg KH To: Florian Fainelli Cc: Will Deacon , Will Deacon , linux-arm-kernel@lists.infradead.org, stable@vger.kernel.org, Catalin Marinas , Marc Zyngier , James Morse , Julien Thierry , Suzuki K Poulose , Mark Rutland , Mark Brown , Kristina Martsenko , Sami Tolvanen , Andrew Jones , Ard Biesheuvel , Nick Desaulniers , Fangrui Song , open list , "open list:KERNEL VIRTUAL MACHINE FOR ARM64 (KVM/arm64)" Subject: Re: [PATCH stable v4.9 v2] arm64: entry: Place an SB sequence following an ERET instruction Message-ID: <20200807131429.GB664450@kroah.com> References: <20200709195034.15185-1-f.fainelli@gmail.com> <20200720130411.GB494210@kroah.com> <9c29080e-8b3a-571c-3296-e0487fa473fa@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9c29080e-8b3a-571c-3296-e0487fa473fa@gmail.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 06, 2020 at 01:00:54PM -0700, Florian Fainelli wrote: > > > On 7/20/2020 11:26 AM, Florian Fainelli wrote: > > On 7/20/20 6:04 AM, Greg KH wrote: > >> On Thu, Jul 09, 2020 at 12:50:23PM -0700, Florian Fainelli wrote: > >>> From: Will Deacon > >>> > >>> commit 679db70801da9fda91d26caf13bf5b5ccc74e8e8 upstream > >>> > >>> Some CPUs can speculate past an ERET instruction and potentially perform > >>> speculative accesses to memory before processing the exception return. > >>> Since the register state is often controlled by a lower privilege level > >>> at the point of an ERET, this could potentially be used as part of a > >>> side-channel attack. > >>> > >>> This patch emits an SB sequence after each ERET so that speculation is > >>> held up on exception return. > >>> > >>> Signed-off-by: Will Deacon > >>> [florian: Adjust hyp-entry.S to account for the label > >>> added change to hyp/entry.S] > >>> Signed-off-by: Florian Fainelli > >>> --- > >>> Changes in v2: > >>> > >>> - added missing hunk in hyp/entry.S per Will's feedback > >> > >> What about 4.19.y and 4.14.y trees? I can't take something for 4.9.y > >> and then have a regression if someone moves to a newer release, right? > > > > Sure, send you candidates for 4.14 and 4.19. > > Greg, did you have a chance to queue those changes for 4.9, 4.14 and 4.19? > > https://lore.kernel.org/linux-arm-kernel/20200720182538.13304-1-f.fainelli@gmail.com/ > https://lore.kernel.org/linux-arm-kernel/20200720182937.14099-1-f.fainelli@gmail.com/ > https://lore.kernel.org/linux-arm-kernel/20200709195034.15185-1-f.fainelli@gmail.com/ Nope, I was waiting for Will's "ack" for these. thanks, greg k-h