From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f66.google.com ([74.125.83.66]:36914 "EHLO mail-pg0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753760AbeFTSi4 (ORCPT ); Wed, 20 Jun 2018 14:38:56 -0400 Received: by mail-pg0-f66.google.com with SMTP id r21-v6so212627pgv.4 for ; Wed, 20 Jun 2018 11:38:56 -0700 (PDT) Date: Wed, 20 Jun 2018 12:38:54 -0600 From: Jason Gunthorpe To: Stefan Berger Cc: linux-integrity@vger.kernel.org, jarkko.sakkinen@linux.intel.com, zohar@linux.vnet.ibm.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/6] tpm: Introduce a kref for the tpm_chip Message-ID: <20180620183854.GC27445@ziepe.ca> References: <20180620161948.1464255-1-stefanb@linux.vnet.ibm.com> <20180620161948.1464255-2-stefanb@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20180620161948.1464255-2-stefanb@linux.vnet.ibm.com> Sender: linux-integrity-owner@vger.kernel.org List-ID: On Wed, Jun 20, 2018 at 12:19:43PM -0400, Stefan Berger wrote: > Introduce a kref for the tpm_chip that we initialize when the tpm_chip has > been allocated and release before the tpm_chip is to be freed. > > Signed-off-by: Stefan Berger > drivers/char/tpm/tpm-chip.c | 24 +++++++++++++++++++----- > drivers/char/tpm/tpm.h | 1 + > 2 files changed, 20 insertions(+), 5 deletions(-) > > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c > index 0a62c19937b6..a933676194a4 100644 > +++ b/drivers/char/tpm/tpm-chip.c > @@ -119,8 +119,24 @@ struct tpm_chip *tpm_chip_find_get(struct tpm_chip *chip) > return res; > } > > +static void tpm_chip_free(struct kref *kref) > +{ > + struct tpm_chip *chip = container_of(kref, struct tpm_chip, kref); > + > + kfree(chip->log.bios_event_log); > + kfree(chip->work_space.context_buf); > + kfree(chip->work_space.session_buf); > + kfree(chip); > +} > + > +static void tpm_chip_put(struct tpm_chip *chip) > +{ > + if (chip) > + kref_put(&chip->kref, tpm_chip_free); > +} > + > /** > - * tpm_dev_release() - free chip memory and the device number > + * tpm_dev_release() - free the device number and release reference to chip > * @dev: the character device for the TPM chip > * > * This is used as the release function for the character device. > @@ -133,10 +149,7 @@ static void tpm_dev_release(struct device *dev) > idr_remove(&dev_nums_idr, chip->dev_num); > mutex_unlock(&idr_lock); > > - kfree(chip->log.bios_event_log); > - kfree(chip->work_space.context_buf); > - kfree(chip->work_space.session_buf); > - kfree(chip); > + tpm_chip_put(chip); > } > static void tpm_devs_release(struct device *dev) > @@ -195,6 +208,7 @@ struct tpm_chip *tpm_chip_alloc(struct device *pdev, > > mutex_init(&chip->tpm_mutex); > init_rwsem(&chip->ops_sem); > + kref_init(&chip->kref); > > chip->ops = ops; > > diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h > index 7f2d0f489e9c..098d7dcc04a4 100644 > +++ b/drivers/char/tpm/tpm.h > @@ -211,6 +211,7 @@ struct tpm_chip { > struct cdev cdev; > struct cdev cdevs; > > + struct kref kref; NAK, there is already a kref in struct device, that one must be used. Jason