From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751796AbeEEUDS (ORCPT ); Sat, 5 May 2018 16:03:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33562 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751183AbeEEUDQ (ORCPT ); Sat, 5 May 2018 16:03:16 -0400 Date: Sat, 5 May 2018 13:03:15 -0700 From: Jerry Snitselaar To: linux-integrity@vger.kernel.org, Laurent Bigonville Cc: linux-kernel@vger.kernel.org, Jarkko Sakkinen , Peter Huewe , Jason Gunthorpe Subject: Re: [PATCH] tpm_tis: verify locality released before returning from release_locality Message-ID: <20180505200315.x7jt33j7psizmfyi@cantor> Reply-To: Jerry Snitselaar Mail-Followup-To: linux-integrity@vger.kernel.org, Laurent Bigonville , linux-kernel@vger.kernel.org, Jarkko Sakkinen , Peter Huewe , Jason Gunthorpe References: <20180505195453.10431-1-jsnitsel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20180505195453.10431-1-jsnitsel@redhat.com> User-Agent: NeoMutt/20180323 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat May 05 18, Jerry Snitselaar wrote: >For certain tpm chips releasing locality can take long enough that a >subsequent call to request_locality will see the locality as being >active when the access register is read in check_locality. So check >that the locality has been released before returning from >release_locality. > >Cc: Jarkko Sakkinen >Cc: Peter Huewe >Cc: Jason Gunthorpe >Reported-by: Laurent Bigonville >Signed-off-by: Jerry Snitselaar >--- > drivers/char/tpm/tpm_tis_core.c | 47 ++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 46 insertions(+), 1 deletion(-) > >diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c >index 5a1f47b43947..d547cd309dbd 100644 >--- a/drivers/char/tpm/tpm_tis_core.c >+++ b/drivers/char/tpm/tpm_tis_core.c >@@ -143,13 +143,58 @@ static bool check_locality(struct tpm_chip *chip, int l) > return false; > } > >+static bool locality_inactive(struct tpm_chip *chip, int l) >+{ >+ struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); >+ int rc; >+ u8 access; >+ >+ rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access); >+ if (rc < 0) >+ return false; >+ >+ if ((access & (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY)) >+ == TPM_ACCESS_VALID) >+ return true; >+ >+ return false; >+} >+ > static int release_locality(struct tpm_chip *chip, int l) > { > struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); >+ unsigned long stop, timeout; >+ long rc; > > tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY); > >- return 0; >+ stop = jiffies + chip->timeout_a; >+ >+ if (chip->flags & TPM_CHIP_FLAG_IRQ) { >+again: >+ timeout = stop - jiffies; >+ if ((long)timeout <= 0) >+ return -1; >+ >+ rc = wait_event_interruptible_timeout(priv->int_queue, >+ (locality_inactive(chip, l)), >+ timeout); >+ >+ if (rc > 0) >+ return 0; >+ >+ if (rc == -ERESTARTSYS && freezing(current)) { >+ clear_thread_flag(TIF_SIGPENDING); >+ goto again; >+ } >+ } else { >+ do { >+ if (locality_inactive(chip, l)) >+ return 0; >+ tpm_msleep(TPM_TIMEOUT); >+ } while (time_before(jiffies, stop)); >+ } >+ return -1; > } > > static int request_locality(struct tpm_chip *chip, int l) >-- >2.15.0 > Laurent, Can you try this patch with your system since it is the one that has exhibited the problem so far. I've tested on a tpm2.0 and tpm1.2 system here. Regards, Jerry