From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:49510 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932162AbdJXO5H (ORCPT ); Tue, 24 Oct 2017 10:57:07 -0400 Date: Tue, 24 Oct 2017 07:57:06 -0700 From: Jerry Snitselaar To: Jarkko Sakkinen 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: <20171024145706.na56ff34w5agzo2t@rhwork> Reply-To: Jerry Snitselaar References: <595efb25-8d87-f39d-037f-9c9a98462339@debian.org> <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> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed In-Reply-To: <20171024135123.uqail7olnespun4k@linux.intel.com> Sender: linux-integrity-owner@vger.kernel.org List-ID: 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?