From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga04.intel.com ([192.55.52.120]:57655 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751336AbdJXQH3 (ORCPT ); Tue, 24 Oct 2017 12:07:29 -0400 Date: Tue, 24 Oct 2017 18:07:25 +0200 From: Jarkko Sakkinen To: Jerry Snitselaar Cc: Laurent Bigonville , Alexander.Steffen@infineon.com, tpmdd-devel@lists.sourceforge.net, linux-integrity@vger.kernel.org Subject: Re: [tpmdd-devel] tpm device not showing up in /dev anymore Message-ID: <20171024160725.r6kj452jdzpkbb6o@linux.intel.com> References: <857106e4bb864bb8a68b1381fffc8f50@MUCSE603.infineon.com> <20170831164015.3ajgwydgxtippwoz@rhwork> <0d9be244-ace0-030d-6ff9-c4e94c63b7e9@debian.org> <20170906040555.fqedhmo5277sd6fq@linux.intel.com> <20171014081318.busge2fhteusfjwx@rhwork> <20171023132346.jbqgokwv3ah2oqjo@linux.intel.com> <20171023134515.56siz3m6lhrhnovv@rhwork> <20171024135123.uqail7olnespun4k@linux.intel.com> <20171024145706.na56ff34w5agzo2t@rhwork> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 In-Reply-To: <20171024145706.na56ff34w5agzo2t@rhwork> Sender: linux-integrity-owner@vger.kernel.org List-ID: On Tue, Oct 24, 2017 at 07:57:06AM -0700, Jerry Snitselaar wrote: > On Tue Oct 24 17, Jarkko Sakkinen wrote: > > On Mon, Oct 23, 2017 at 06:45:15AM -0700, Jerry Snitselaar wrote: > > > On Mon Oct 23 17, Jarkko Sakkinen wrote: > > > > On Sat, Oct 21, 2017 at 10:53:55AM +0200, Laurent Bigonville wrote: > > > > > Le 14/10/17 a 10:13, Jerry Snitselaar a ecrit : > > > > > > On Wed Sep 06 17, Jarkko Sakkinen wrote: > > > > > > > On Fri, Sep 01, 2017 at 02:10:18PM +0200, Laurent Bigonville wrote: > > > > > > > > Le 31/08/17 a 18:40, Jerry Snitselaar a ecrit : > > > > > > > > > On Thu Aug 31 17, Alexander.Steffen@infineon.com wrote: > > > > > > > > > > > Le 29/08/17 a 18:35, Laurent Bigonville a ecrit : > > > > > > > > > > > > Le 29/08/17 a 18:00, Alexander.Steffen@infineon.com a ecrit : > > > > > > > > > > > >>> An idea how to troubleshoot this? > > > > > > > > > > > >> Can you run git bisect on the changes between 4.11 and > > > > > > > > 4.12, so that > > > > > > > > > > > >> we find the offending commit? It is probably sufficient > > > > > > > > to limit the > > > > > > > > > > > >> search to commits that touch something in drivers/char/tpm. > > > > > > > > > > > > > > > > > > > > > > > > I'll try and keep you posted. > > > > > > > > > > > > > > > > > > > > > > OK I've been able to bisect the problem and the bad commit is: > > > > > > > > > > > > > > > > > > > > > > e6aef069b6e97790cb127d5eeb86ae9ff0b7b0e3 is the first bad commit > > > > > > > > > > > commit e6aef069b6e97790cb127d5eeb86ae9ff0b7b0e3 > > > > > > > > > > > Author: Jerry Snitselaar > > > > > > > > > > > Date: Mon Mar 27 08:46:04 2017 -0700 > > > > > > > > > > > > > > > > > > > > > > tpm_tis: convert to using locality callbacks > > > > > > > > > > > > > > > > > > > > > > This patch converts tpm_tis to use of the new tpm class ops > > > > > > > > > > > request_locality, and relinquish_locality. > > > > > > > > > > > > > > > > > > > > > > With the move to using the callbacks, release_locality is > > > > > > > > > > > changed so > > > > > > > > > > > that we now release the locality even if there is no > > > > > > > > > > > request pending. > > > > > > > > > > > > > > > > > > > > > > This required some changes to the tpm_tis_core_init > > > > > > > > code path to > > > > > > > > > > > make sure locality is requested when needed: > > > > > > > > > > > > > > > > > > > > > > - tpm2_probe code path will end up calling > > > > > > > > > > > request/release through > > > > > > > > > > > callbacks, so request_locality prior to > > > > > > > > tpm2_probe not needed. > > > > > > > > > > > > > > > > > > > > > > - probe_itpm makes calls to tpm_tis_send_data which no > > > > > > > > > > > longer calls > > > > > > > > > > > request_locality, so add request_locality prior to > > > > > > > > > > > tpm_tis_send_data > > > > > > > > > > > calls. Also drop release_locality call in middleof > > > > > > > > > > > probe_itpm, and > > > > > > > > > > > keep locality until release_locality called at end of > > > > > > > > > > > probe_itpm. > > > > > > > > > > > > > > > > > > > > > > Cc: Peter Huewe > > > > > > > > > > > Cc: Jarkko Sakkinen > > > > > > > > > > > Cc: Jason Gunthorpe > > > > > > > > > > > Cc: Marcel Selhorst > > > > > > > > > > > Signed-off-by: Jerry Snitselaar > > > > > > > > > > > Reviewed-by: Jarkko Sakkinen > > > > > > > > > > > > > > > > > > > Tested-by: Jarkko Sakkinen > > > > > > > > > > > Signed-off-by: Jarkko Sakkinen > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > :040000 040000 70234365da69959d47076ebb40c8d17f520c3e44 > > > > > > > > > > > 72f21b446e45ea1003de75902b0553deb99157fd M drivers > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > I've looked again at the code in question, but could not find > > > > > > > > > > anything that is obviously wrong there. Locality is now > > > > > > > > > > requested/released at slightly different points in the process than > > > > > > > > > > before, but that's it. It does not seem to cause problems with the > > > > > > > > > > majority of TPMs, since you are the first to report any, so > > > > > > > > maybe it > > > > > > > > > > is a quirk that only affects this device. > > > > > > > > > > > > > > > > > > > > Perhaps Jerry can help, since this is his change? > > > > > > > > > > > > > > > > > > > > Alexander > > > > > > > > > > > > > > > > > > Getting some caffeine in me, and starting to take a look. Adding > > > > > > > > > Jarkko as well since this might involve the general locality changes. > > > > > > > > > > > > > > > > > > Laurent, if I send you a patch with some debugging code added, would > > > > > > > > > you be able to run it on that system? I wasn't running into issues > > > > > > > > > on the system I had with a 1.2 device, but I no longer have access > > > > > > > > > to it. I'll see if I can find one in our labs and reproduce it there. > > > > > > > > > > > > > > > > Yes I should be able to do that > > > > > > > > > > > > > > Any findings? > > > > > > > > > > > > > > /Jarkko > > > > > > > > > > > > Okay, finally getting back to this. Looking at the code it isn't clear > > > > > > to me > > > > > > why the change is causing this. So while I stare at this some more > > > > > > Laurent > > > > > > could you reproduce it with this patch so I can see what the status and > > > > > > access registers look like? Does anyone else on here happen to have a > > > > > > Sinosun > > > > > > tpm device? The systems I have access to with TPM1.2 devices don't have > > > > > > this > > > > > > issue. > > > > > > > > > > > > --8<-- > > > > > > > > > > > > diff --git a/drivers/char/tpm/tpm_tis_core.c > > > > > > b/drivers/char/tpm/tpm_tis_core.c > > > > > > index fdde971bc810..7d60a7e4b50a 100644 > > > > > > --- a/drivers/char/tpm/tpm_tis_core.c > > > > > > +++ b/drivers/char/tpm/tpm_tis_core.c > > > > > > @@ -258,6 +258,7 @@ static int tpm_tis_send_data(struct tpm_chip *chip, > > > > > > const u8 *buf, size_t len) > > > > > > int rc, status, burstcnt; > > > > > > size_t count = 0; > > > > > > bool itpm = priv->flags & TPM_TIS_ITPM_WORKAROUND; > > > > > > + u8 access; > > > > > > > > > > > > status = tpm_tis_status(chip); > > > > > > if ((status & TPM_STS_COMMAND_READY) == 0) { > > > > > > @@ -292,6 +293,11 @@ static int tpm_tis_send_data(struct tpm_chip *chip, > > > > > > const u8 *buf, size_t len) > > > > > > } > > > > > > status = tpm_tis_status(chip); > > > > > > if (!itpm && (status & TPM_STS_DATA_EXPECT) == 0) { > > > > > > + rc = tpm_tis_read8(priv, TPM_ACCESS(priv->locality), > > > > > > &access); > > > > > > + if (rc < 0) > > > > > > + dev_info(&chip->dev, "TPM_STS_DATA_EXPECT == 0: read > > > > > > failure TPM_ACCESS(%d)\n", priv->locality); > > > > > > + else > > > > > > + dev_info(&chip->dev, "TPM_STS_DATA_EXPECT == 0: > > > > > > locality: %d status: %x access: %x\n", priv->locality, status, access); > > > > > > rc = -EIO; > > > > > > goto out_err; > > > > > > } > > > > > > @@ -309,6 +315,11 @@ static int tpm_tis_send_data(struct tpm_chip *chip, > > > > > > const u8 *buf, size_t len) > > > > > > } > > > > > > status = tpm_tis_status(chip); > > > > > > if (!itpm && (status & TPM_STS_DATA_EXPECT) != 0) { > > > > > > + rc = tpm_tis_read8(priv, TPM_ACCESS(priv->locality), &access); > > > > > > + if (rc < 0) > > > > > > + dev_info(&chip->dev, "TPM_STS_DATA_EXPECT != 0: read > > > > > > failure TPM_ACCESS(%d)\n", priv->locality); > > > > > > + else > > > > > > + dev_info(&chip->dev, "TPM_STS_DATA_EXPECT != 0: locality: > > > > > > %d status: %x access: %x\n", priv->locality, status, access); > > > > > > rc = -EIO; > > > > > > goto out_err; > > > > > > } > > > > > > > > > > Please find here the dmesg output of the patched kernel > > > > > > > > At least 0xff is corrupted value in senseful way. CPU fills the read > > > > with ones for example for unaligned bus read. See table 19 in PC client > > > > spec. This can happen when you do unaligned read for example. > > > > > > > > Maybe TPM is unreachable i.e. powered off. Bit busy with stuff ATM but > > > > would probably make sense to compare that 0x81 to table 18 in the same > > > > spec. > > > > > > > > /Jarkko > > > > > > 0x81 is saying the access register status is valid, and the locality > > > is not active. That first bit means A Dynamic OS has not been previously > > > established on the platform. Normally we would see 0xa1, which would > > > mean valid register status, and the locality is active. > > > > I think the important thing to note here is that STS has bits set that > > should never be set. So we can conclude that TPM might be either > > > > 1. Powered off > > 2. In some transition state? > > > > /Jarkko > > If it was powered off would we be getting a valid read from the access > register? I think there is no universal answer to that :-) Maybe adding a extra delay would be next test to make? If for random reason it is in-between states... /Jarkko