Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752124AbcJBKRw (ORCPT ); Sun, 2 Oct 2016 06:17:52 -0400 Received: from mga05.intel.com ([192.55.52.43]:8280 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751404AbcJBKRu (ORCPT ); Sun, 2 Oct 2016 06:17:50 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,284,1473145200"; d="scan'208";a="15404855" Date: Sun, 2 Oct 2016 13:17:55 +0300 From: Jarkko Sakkinen To: Tomas Winkler Cc: tpmdd-devel@lists.sourceforge.net, Jason Gunthorpe , linux-kernel@vger.kernel.org Subject: Re: [PATCH] tpm: don't destroy chip device prematurely Message-ID: <20161002101755.GA25844@intel.com> References: <1475393971-12715-1-git-send-email-tomas.winkler@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1475393971-12715-1-git-send-email-tomas.winkler@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1501 Lines: 45 On Sun, Oct 02, 2016 at 10:39:31AM +0300, Tomas Winkler wrote: > In tpm_del_char_device device_del is called > prior to tpm2_shutdown where it is still used. > > Fortunately, so far chip->dev was used only for printouts > int tpm2_shutdown flow, hence system didn't crash. But with > the introduction of runtime power management it will result in > shutting down the parent device while it still in use. > > Fixes: 20e0152393b41 ("tpm: fix crash in tpm_tis deinitialization") > Signed-off-by: Tomas Winkler Tested-by: Jarkko Sakkinen Reviewed-by: Jarkko Sakkinen /Jarkko > --- > drivers/char/tpm/tpm-chip.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c > index e5950131bd90..b1cb0aae8e66 100644 > --- a/drivers/char/tpm/tpm-chip.c > +++ b/drivers/char/tpm/tpm-chip.c > @@ -261,7 +261,6 @@ static int tpm_add_char_device(struct tpm_chip *chip) > static void tpm_del_char_device(struct tpm_chip *chip) > { > cdev_del(&chip->cdev); > - device_del(&chip->dev); > > /* Make the chip unavailable. */ > mutex_lock(&idr_lock); > @@ -274,6 +273,8 @@ static void tpm_del_char_device(struct tpm_chip *chip) > tpm2_shutdown(chip, TPM2_SU_CLEAR); > chip->ops = NULL; > up_write(&chip->ops_sem); > + > + device_del(&chip->dev); > } > > static int tpm1_chip_register(struct tpm_chip *chip) > -- > 2.7.4 >