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=-6.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 27473C11F67 for ; Tue, 29 Jun 2021 22:05:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0CC7261DA2 for ; Tue, 29 Jun 2021 22:05:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235335AbhF2WHr (ORCPT ); Tue, 29 Jun 2021 18:07:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:42650 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234953AbhF2WHq (ORCPT ); Tue, 29 Jun 2021 18:07:46 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1C26D61DA0; Tue, 29 Jun 2021 22:05:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625004318; bh=wL4QubpVslVkyqpPYOVGapr51ugDCN40mrI1cMYOd3s=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mHZD86XEw5OblpWiif0Ap7A/Rozq76oL+oSo8bdhOjX1xlrdGZhDkIDrLnp9y0qtF VhOhnhxocUVjv1E4NAmyY4tY7v/iD+GO99jFNcEmhKQ7gfmTm+go9p56vBJHmVTmQF 4Ah+0bebDFVY4HIgmLVrEbT5ZiyFsSNB4saAbTamM+91fc/NM//5qVQKVTCTSczcSa NeRJZUkNrj2AMKY4TrGvBM4uulEd6CLGFL8eBLWdjnzR8fDHxMe+kjs3S9rlJoI3aS m2cm+RR7t4ZJZPR+gWH51pagUajDvtesIYOertvk8Mf623uHNR4NKYDURXnUqaeEes kKkXcnQnfr6FQ== Date: Wed, 30 Jun 2021 01:05:16 +0300 From: Jarkko Sakkinen To: Hans de Goede Cc: Jerry Snitselaar , Matthew Garrett , linux-integrity , James Bottomley Subject: Re: Recent tpm_tis IRQ handling changes are causing kernel backtraces] Message-ID: <20210629220516.xm3jvjy7v2uw3fvz@kernel.org> References: <20210527140025.vl3ply6wnn7rsygg@kernel.org> <27d71b81-1e89-1b5d-ddaf-a8928bac90fd@redhat.com> <20210531043616.u3v25qzkkrik5apq@kernel.org> <89d5b891-97d8-caed-4eb1-6d4d485a2fd1@redhat.com> <5680899e-9040-7641-e6ac-23edd2d988cf@redhat.com> <49bfb4a7-eb3c-77f9-ff8e-b37617a26195@redhat.com> <20210623134054.45gjj2wbgz7jpjmy@kernel.org> <90ed51b4-66d4-fb10-ca8e-d99532028fab@redhat.com> <20210629180445.oind62rsktevm45q@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On Tue, Jun 29, 2021 at 09:14:39PM +0200, Hans de Goede wrote: > Hi, > > On 6/29/21 8:04 PM, Jarkko Sakkinen wrote: > > On Wed, Jun 23, 2021 at 03:54:59PM +0200, Hans de Goede wrote: > >> Hi, > >> > >> On 6/23/21 3:40 PM, Jarkko Sakkinen wrote: > >>> On Mon, Jun 21, 2021 at 02:04:52PM +0200, Hans de Goede wrote: > >>>> Hi, > >>>> > >>>> On 6/14/21 3:33 PM, Hans de Goede wrote: > >>>>> Hi, > >>>>> > >>>>> On 6/1/21 6:04 PM, Hans de Goede wrote: > >>>>>> Hi, > >>>>>> > >>>>>> On 5/31/21 6:36 AM, Jarkko Sakkinen wrote: > >>>>>>>> Interestingly enough the first backtrace is also happening on a: > >>>>>>>> "Dell Inc. XPS 13 9310/0MRT12, BIOS 2.2.0 04/06/2021" > >>>>>>>> > >>>>>>>> So it seems that at least with 5.12.6 (which has the last 2 fixes) > >>>>>>>> all reports are about the XPS 13 9310. I wonder if there is an > >>>>>>>> issue with the TPM interrupt line on the XPS 13 9310; I've asked the > >>>>>>>> reporters to try adding tpm_tis.interrupts=0 to their kernel commandline. > >>>>>>> > >>>>>>> This is helpful for sure that these all are happening on matching hardware. > >>>>>> > >>>>>> So our kernel-backtrace tracking info (ABRT) just recorded a third backtrace > >>>>>> with a kernel >= 5.12.6, again on the XPS 13 9310, so now we have 3 variants: > >>>>>> > >>>>>> 1. Backtrace starting with a call to ima_add_boot_aggregate > >>>>>> https://bugzilla.redhat.com/show_bug.cgi?id=1963712 > >>>>>> > >>>>>> 2. Backtrace starting with a call to tpm_dev_async_work: > >>>>>> https://bugzilla.redhat.com/show_bug.cgi?id=1964974 > >>>>>> (note this one is not easily reproducible) > >>>>>> > >>>>>> 3. Backtrace starting with a call to rng_dev_read: > >>>>>> https://bugzilla.redhat.com/show_bug.cgi?id=1920510 > >>>>>> > >>>>>> 3. is the new one. All bugs linked above are public, all 3 backtraces > >>>>>> so far have only been reported on the XPS 13 9310 (with kernel >= 5.12.6) > >>>>>> and I've asked all the reporters to check if tpm_tis.interrupts=0 helps. > >>>>> > >>>>> Quick status update, I've got a response from a XPS 13 9310 user in: > >>>>> > >>>>> https://bugzilla.redhat.com/show_bug.cgi?id=1920510 > >>>>> > >>>>> Indicating that a. he can reproduce this with the latest >= 5.12.6 kernels; > >>>>> and b. it goes away when specifying tpm_tis.interrupts=0 as I expected > >>>>> (I expected this because all the bug-reports started when the interrupt > >>>>> code got fixed/re-enabled a while ago). > >>>> > >>>> One more status update. > >>>> > >>>> - A new 4th variant of the backtrace has been spotted, where the problem hits > >>>> when called from probe() -> tpm2_auto_startup -> tpm2_do_selftest, see: > >>>> https://bugzilla.redhat.com/show_bug.cgi?id=1958381 > >>>> > >>>> - So far all reports with kernel >= 5.12.6 have been on a Dell XPS 13 9310 > >>>> models. But the new variant is happening on a Dell XPS 15 9500 and the > >>>> backtrace starting at ima_add_boot_aggregate is also being reported on > >>>> a Dell XPS 15 9500 (as well as on the XPS 13 9310). > >>>> > >>>> Regards, > >>>> > >>>> Hans > >>> > >>> OK, I'll have to query if I could borrow that laptop from someone. It's > >>> fairly common laptop, i.e. might be possible. > >> > >> In the mean time I've also got a report that this variant of the backtrace: > >> > >> 1. Backtrace starting with a call to ima_add_boot_aggregate > >> https://bugzilla.redhat.com/show_bug.cgi?id=1963712 > >> > >> Is also still happening with recent 5.12.y kernels on > >> Dell Precision 7750 laptops. Both the Precision 7750 and the XPS 9500 use > >> 10th gen comet lake processors (i7-10750H), where as the XPS 9310 is using > >> an icelake processor. So the common denominator seems to be that they are > >> all 2020 Dell laptop models using the latest Intel CPUs. > >> > >> FYI the complete list of models on which some of the 4 backtrace variants > >> are still seen on recent 5.12.y kernels is now: > >> > >> Dell XPS 13 9310 > >> Dell XPS 15 9500 > >> Dell Precision 7750 > >> > >> Regards, > >> > >> Hans > > > > Does "tpm_tis.interrupts=0" uniformly workaround the issue? > > I unfortunately have not gotten much replies to my request to test with > tpm_tis.interrupts=0, but for those people who have bothered to test > (2 reporters IIRC) using tpm_tis.interrupts=0 does avoid the issue. So we see this in dmesg as first anything from TPM: [ 0.904572] tpm_tis STM0125:00: 2.0 TPM (device-id 0x0, rev-id 78) This means that one command is successfully processed by the TPM, i.e. tpm2_probe() in tpm_tis_core_init(). My first *guess* was that IRQ is given by ACPI, would need ACPI dump to confirm (e.g. sudo acpidump > acpi.dump). It cannot be so because otherwise this code path would be executed: if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) { dev_err(&chip->dev, FW_BUG "TPM interrupt not working, polling instead\n"); disable_interrupts(chip); } TPM_CHIP_FLAG_IRQ is never set, so you should see this message in dmesg if a legit value is given to IRQ by ACPI. We are probably planning re-enable IRQ code after these type of issues are fully resolved, but right now you should not end up having it enabled (see tpm_tis_send() function). To put this together "if (irq != -1) {" path in tpm_tis_core_init() is never executed. And early in the same function the interrupt hardware is *explicitly* disabled. For me this looks like a hardware bug right now: interrupts stay enabled for some reason. ACPI dump would be useful to verify some of the assumptions in this. /Jarkko