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=-18.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=ham 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 92268C48BD1 for ; Thu, 10 Jun 2021 21:05:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 72477613D8 for ; Thu, 10 Jun 2021 21:05:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230059AbhFJVHB (ORCPT ); Thu, 10 Jun 2021 17:07:01 -0400 Received: from linux.microsoft.com ([13.77.154.182]:59734 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229963AbhFJVHB (ORCPT ); Thu, 10 Jun 2021 17:07:01 -0400 Received: from sequoia (162-237-133-238.lightspeed.rcsntx.sbcglobal.net [162.237.133.238]) by linux.microsoft.com (Postfix) with ESMTPSA id 1A69520B7178; Thu, 10 Jun 2021 14:05:03 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 1A69520B7178 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1623359104; bh=9heYwDg7HkXqmnRyjiu31yAcnxTkKMw3sVGVK8qX7II=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=NL/mZr/sTjypmf8YXwF9PG/hiD3wixy3Z8rZov3Q4mL477kgo3L+JGWgn5s1E/IhJ ok1Q2mM+7sKmkUGr4th02hNY+gb2HRC533UHj4s/mXCKrzfqjZeeNL1WvBMeab1g3z TJczE2jmC3xVo/G1up5fiW4ZFLlX5bKSWA+85HKs= Date: Thu, 10 Jun 2021 16:05:01 -0500 From: Tyler Hicks To: Jens Wiklander Cc: Sumit Garg , Rijo-john.Thomas@amd.com, Allen Pais , Peter Huewe , Jarkko Sakkinen , Jason Gunthorpe , Vikas Gupta , Thirupathaiah Annapureddy , Pavel Tatashin , =?utf-8?B?UmFmYcWCIE1pxYJlY2tp?= , op-tee@lists.trustedfirmware.org, linux-integrity , bcm-kernel-feedback-list@broadcom.com, linux-mips@vger.kernel.org, Linux Kernel Mailing List Subject: Re: [PATCH v3 5/7] tee: Support shm registration without dma-buf backing Message-ID: <20210610210501.GP4910@sequoia> References: <20210609002326.210024-1-tyhicks@linux.microsoft.com> <20210609002326.210024-6-tyhicks@linux.microsoft.com> <20210609054621.GB4910@sequoia> <20210609121533.GA2267052@jade> <20210609134225.GC4910@sequoia> <20210610074948.GC2753553@jade> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210610074948.GC2753553@jade> Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On 2021-06-10 09:49:48, Jens Wiklander wrote: > On Wed, Jun 09, 2021 at 08:42:25AM -0500, Tyler Hicks wrote: > [snip] > > > I've just posted "[PATCH 0/7] tee: shared memory updates", > > > https://lore.kernel.org/lkml/20210609102324.2222332-1-jens.wiklander@linaro.org/ > > > > > > Where tee_shm_alloc() is replaced by among other functions > > > tee_shm_alloc_kernel_buf(). tee_shm_alloc_kernel_buf() takes care of the > > > problem with TEE_SHM_DMA_BUF. > > > > Thanks! At first glance, that series would take care of the last three > > patches in my kexec/kdump series. > > > > I'm a bit worried that it is a rewrite of the shm allocator. Do you plan > > to send all of that to stable? (I mentioned earlier in this thread that > > I'm affected by these bugs in linux-5.4.y.) > > No, that might be a bit much. > > > Also, you and Sumit don't seem to have the same opinion on kernel > > drivers making use of tee_shm_register() for allocations that are only > > used internally. Can you comment on that? > > > > I'm not clear on the next steps for fixing these kexec/kdump bugs in > > older releases. I appreciate any guidance here. > > Neither am I be honest. You're the only one that has brought up this > problem so perhaps it's enough to focus on the stable branch you need to > have fixed. I've already added Fixes tags to all of my patches. If you are comfortable with them going to stable, you'd add 'Cc: stable@vger.kernel.org' to them if/when you merge them so that the stable team will ensure that they're applied. Note that I'm not the only person that brought up this bug: https://github.com/OP-TEE/optee_os/issues/3637 Once I started digging in, I realized that there were more kexec/kdump bugs and the series grew. > If I've understood it correctly it's best if it's possible to > cherry-pick the fixes from mainline to the stable branch in question. > So we must make sure to get your needed patches in before any rewrites > that would make cherry-picking impossible. The rewrite I'm proposing > isn't urgent so it can be held off for a while. Thanks for holding off. I'll be quick on my revisions so that you don't have to moth ball your series for too much longer. Tyler > > Cheers, > Jens >