Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754050AbcDKRks (ORCPT ); Mon, 11 Apr 2016 13:40:48 -0400 Received: from quartz.orcorp.ca ([184.70.90.242]:60951 "EHLO quartz.orcorp.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751175AbcDKRkr (ORCPT ); Mon, 11 Apr 2016 13:40:47 -0400 Date: Mon, 11 Apr 2016 11:40:37 -0600 From: Jason Gunthorpe To: Jarkko Sakkinen Cc: Peter Huewe , Marcel Selhorst , "moderated list:TPM DEVICE DRIVER" , open list Subject: Re: [PATCH] tpm: fix crash in tpm_tis deinitialization Message-ID: <20160411174037.GA371@obsidianresearch.com> References: <1460390720-9509-1-git-send-email-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1460390720-9509-1-git-send-email-jarkko.sakkinen@linux.intel.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-Broken-Reverse-DNS: no host name found for IP address 10.0.0.160 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1939 Lines: 51 On Mon, Apr 11, 2016 at 07:05:20PM +0300, Jarkko Sakkinen wrote: > rmmod crashes the driver because tpm_chip_unregister() already sets ops > to NULL. This commit fixes the issue by moving tpm2_shutdown() to > tpm_chip_unregister(). This commit is also cleanup because it removes > duplicate code from tpm_crb and tpm_tis to the core. > > Signed-off-by: Jarkko Sakkinen > Fixes: 4d3eac5e156a ("tpm: Provide strong locking for device removal") > drivers/char/tpm/tpm-chip.c | 3 +++ > drivers/char/tpm/tpm_crb.c | 3 --- > drivers/char/tpm/tpm_tis.c | 3 --- > 3 files changed, 3 insertions(+), 6 deletions(-) > > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c > index f62c851..2642cca 100644 > +++ b/drivers/char/tpm/tpm-chip.c > @@ -361,6 +361,9 @@ void tpm_chip_unregister(struct tpm_chip *chip) > if (!(chip->flags & TPM_CHIP_FLAG_REGISTERED)) > return; > > + if (chip->flags & TPM_CHIP_FLAG_TPM2) > + tpm2_shutdown(chip, TPM2_SU_CLEAR); > + > if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) > sysfs_remove_link(&chip->dev.parent->kobj, "ppi"); This needs to be after ops is fenced, something like this. diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 2642cca05cac..2ea2f1561e59 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -269,6 +269,8 @@ static void tpm_del_char_device(struct tpm_chip *chip) /* Make the driver uncallable. */ down_write(&chip->ops_sem); + if (chip->flags & TPM_CHIP_FLAG_TPM2) + tpm2_shutdown(chip, TPM2_SU_CLEAR); chip->ops = NULL; up_write(&chip->ops_sem); } @@ -361,9 +363,6 @@ void tpm_chip_unregister(struct tpm_chip *chip) if (!(chip->flags & TPM_CHIP_FLAG_REGISTERED)) return; - if (chip->flags & TPM_CHIP_FLAG_TPM2) - tpm2_shutdown(chip, TPM2_SU_CLEAR); - if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) sysfs_remove_link(&chip->dev.parent->kobj, "ppi");