From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753278AbeDXRsM (ORCPT ); Tue, 24 Apr 2018 13:48:12 -0400 Received: from mga14.intel.com ([192.55.52.115]:49633 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752074AbeDXRsI (ORCPT ); Tue, 24 Apr 2018 13:48:08 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,324,1520924400"; d="scan'208";a="222985279" Date: Tue, 24 Apr 2018 20:48:02 +0300 From: Jarkko Sakkinen To: "Winkler, Tomas" Cc: "'Jason Gunthorpe'" , "Usyskin, Alexander" , "'linux-integrity@vger.kernel.org'" , "'linux-security-module@vger.kernel.org'" , "'linux-kernel@vger.kernel.org'" Subject: Re: [PATCH] tpm: tpm_crb: relinquish locality on error path. Message-ID: <20180424174802.GA24613@linux.intel.com> References: <20180407161236.22969-1-tomas.winkler@intel.com> <5B8DA87D05A7694D9FA63FD143655C1B94252660@hasmsx108.ger.corp.intel.com> <4984305eae452b7a72b8a13aa20cecec420df580.camel@linux.intel.com> <5B8DA87D05A7694D9FA63FD143655C1B94252945@hasmsx108.ger.corp.intel.com> <5B8DA87D05A7694D9FA63FD143655C1B942627FD@hasmsx108.ger.corp.intel.com> <20180424160328.GA5119@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180424160328.GA5119@linux.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 24, 2018 at 07:03:28PM +0300, Jarkko Sakkinen wrote: > On Fri, Apr 20, 2018 at 01:19:12PM +0000, Winkler, Tomas wrote: > > > > On Tue, 2018-04-10 at 09:00 +0000, Winkler, Tomas wrote: > > > > > > > > > > > > On Sat, 2018-04-07 at 19:12 +0300, Tomas Winkler wrote: > > > > > > > In crb_map_io() function, __crb_request_locality() is called > > > > > > > prior to crb_cmd_ready(), but if one of the consecutive function > > > > > > > fails the flow bails out instead of trying to relinquish locality. > > > > > > > This patch adds goto jump to __crb_relinquish_locality() on the > > > > > > > error path. > > > > > > > > > > > > > > Fixes: 888d867df441 (tpm: cmd_ready command can be issued only > > > > > > > after granting > > > > > > > locality) > > > > > > > Signed-off-by: Tomas Winkler > > > > > > > --- > > > > > > > drivers/char/tpm/tpm_crb.c | 10 +++++++--- > > > > > > > 1 file changed, 7 insertions(+), 3 deletions(-) > > > > > > > > > > > > > > diff --git a/drivers/char/tpm/tpm_crb.c > > > > > > > b/drivers/char/tpm/tpm_crb.c index 7f78482cd157..34fbc6cb097b > > > > > > > 100644 > > > > > > > --- a/drivers/char/tpm/tpm_crb.c > > > > > > > +++ b/drivers/char/tpm/tpm_crb.c > > > > > > > @@ -511,8 +511,10 @@ static int crb_map_io(struct acpi_device > > > > > > > *device, struct crb_priv *priv, > > > > > > > > > > > > > > priv->regs_t = crb_map_res(dev, priv, &io_res, buf- > > > > > > > >control_address, > > > > > > > sizeof(struct crb_regs_tail)); > > > > > > > - if (IS_ERR(priv->regs_t)) > > > > > > > - return PTR_ERR(priv->regs_t); > > > > > > > + if (IS_ERR(priv->regs_t)) { > > > > > > > + ret = PTR_ERR(priv->regs_t); > > > > > > > + goto out_relinquish_locality; > > > > > > > + } > > > > > > > > > > > > > > /* > > > > > > > * PTT HW bug w/a: wake up the device to access @@ -520,7 > > > > > > > +522,7 > > > > > > > > > > > > @@ > > > > > > > static int crb_map_io(struct acpi_device *device, struct > > > > > > > crb_priv *priv, > > > > > > > */ > > > > > > > ret = crb_cmd_ready(dev, priv); > > > > > > > if (ret) > > > > > > > - return ret; > > > > > > > + goto out_relinquish_locality; > > > > > > > > > > > > > > pa_high = ioread32(&priv->regs_t->ctrl_cmd_pa_high); > > > > > > > pa_low = ioread32(&priv->regs_t->ctrl_cmd_pa_low); > > > > > > > @@ -565,6 +567,8 @@ static int crb_map_io(struct acpi_device > > > > > > > *device, struct crb_priv *priv, > > > > > > > > > > > > > > crb_go_idle(dev, priv); > > > > > > > > > > > > > > +out_relinquish_locality: > > > > > > > + > > > > > > > __crb_relinquish_locality(dev, priv, 0); > > > > > > > > > > > > > > return ret; > > > > > > > > > > > > Thanks, please just call it before returning in the error path. > > > > > > > > > > Can you please elaborate why, isn't the centralized exiting of > > > > > functions preferred kernel coding style? > > > > > https://www.kernel.org/doc/html/v4.11/process/coding-style.html#cent > > > > > ra > > > > > lized-ex > > > > > iting-of-functions > > > > > > > > You exit only from one location (not multiple) and not from a nested > > > > context. Here you just add more complexity by doing this. > > > > > > Where is the complexity ? I see it as a standard way of undoing on exit. > > > Tomas > > > > Jarkko, can you please respond. > > Thanks > > Tomas > > I was away for Mon-Wed last week and did not work on TPM for Thu-Fri. > > My earlier comment was incorrect as there are two locations to exit (not > sure how I managed to overlook the patch that way). > > Thus, I have only two very minor requets: > > * Remove the extra newline (the last line addition in the patch). > * Use just label named out as we have only one exception handler. > > I'll move on to testing, and if it it passes, I can do those updates > myself. > > /Jarkko Tested-by: Jarkko Sakkinen /Jarkko From mboxrd@z Thu Jan 1 00:00:00 1970 From: jarkko.sakkinen@linux.intel.com (Jarkko Sakkinen) Date: Tue, 24 Apr 2018 20:48:02 +0300 Subject: [PATCH] tpm: tpm_crb: relinquish locality on error path. In-Reply-To: <20180424160328.GA5119@linux.intel.com> References: <20180407161236.22969-1-tomas.winkler@intel.com> <5B8DA87D05A7694D9FA63FD143655C1B94252660@hasmsx108.ger.corp.intel.com> <4984305eae452b7a72b8a13aa20cecec420df580.camel@linux.intel.com> <5B8DA87D05A7694D9FA63FD143655C1B94252945@hasmsx108.ger.corp.intel.com> <5B8DA87D05A7694D9FA63FD143655C1B942627FD@hasmsx108.ger.corp.intel.com> <20180424160328.GA5119@linux.intel.com> Message-ID: <20180424174802.GA24613@linux.intel.com> To: linux-security-module@vger.kernel.org List-Id: linux-security-module.vger.kernel.org On Tue, Apr 24, 2018 at 07:03:28PM +0300, Jarkko Sakkinen wrote: > On Fri, Apr 20, 2018 at 01:19:12PM +0000, Winkler, Tomas wrote: > > > > On Tue, 2018-04-10 at 09:00 +0000, Winkler, Tomas wrote: > > > > > > > > > > > > On Sat, 2018-04-07 at 19:12 +0300, Tomas Winkler wrote: > > > > > > > In crb_map_io() function, __crb_request_locality() is called > > > > > > > prior to crb_cmd_ready(), but if one of the consecutive function > > > > > > > fails the flow bails out instead of trying to relinquish locality. > > > > > > > This patch adds goto jump to __crb_relinquish_locality() on the > > > > > > > error path. > > > > > > > > > > > > > > Fixes: 888d867df441 (tpm: cmd_ready command can be issued only > > > > > > > after granting > > > > > > > locality) > > > > > > > Signed-off-by: Tomas Winkler > > > > > > > --- > > > > > > > drivers/char/tpm/tpm_crb.c | 10 +++++++--- > > > > > > > 1 file changed, 7 insertions(+), 3 deletions(-) > > > > > > > > > > > > > > diff --git a/drivers/char/tpm/tpm_crb.c > > > > > > > b/drivers/char/tpm/tpm_crb.c index 7f78482cd157..34fbc6cb097b > > > > > > > 100644 > > > > > > > --- a/drivers/char/tpm/tpm_crb.c > > > > > > > +++ b/drivers/char/tpm/tpm_crb.c > > > > > > > @@ -511,8 +511,10 @@ static int crb_map_io(struct acpi_device > > > > > > > *device, struct crb_priv *priv, > > > > > > > > > > > > > > priv->regs_t = crb_map_res(dev, priv, &io_res, buf- > > > > > > > >control_address, > > > > > > > sizeof(struct crb_regs_tail)); > > > > > > > - if (IS_ERR(priv->regs_t)) > > > > > > > - return PTR_ERR(priv->regs_t); > > > > > > > + if (IS_ERR(priv->regs_t)) { > > > > > > > + ret = PTR_ERR(priv->regs_t); > > > > > > > + goto out_relinquish_locality; > > > > > > > + } > > > > > > > > > > > > > > /* > > > > > > > * PTT HW bug w/a: wake up the device to access @@ -520,7 > > > > > > > +522,7 > > > > > > > > > > > > @@ > > > > > > > static int crb_map_io(struct acpi_device *device, struct > > > > > > > crb_priv *priv, > > > > > > > */ > > > > > > > ret = crb_cmd_ready(dev, priv); > > > > > > > if (ret) > > > > > > > - return ret; > > > > > > > + goto out_relinquish_locality; > > > > > > > > > > > > > > pa_high = ioread32(&priv->regs_t->ctrl_cmd_pa_high); > > > > > > > pa_low = ioread32(&priv->regs_t->ctrl_cmd_pa_low); > > > > > > > @@ -565,6 +567,8 @@ static int crb_map_io(struct acpi_device > > > > > > > *device, struct crb_priv *priv, > > > > > > > > > > > > > > crb_go_idle(dev, priv); > > > > > > > > > > > > > > +out_relinquish_locality: > > > > > > > + > > > > > > > __crb_relinquish_locality(dev, priv, 0); > > > > > > > > > > > > > > return ret; > > > > > > > > > > > > Thanks, please just call it before returning in the error path. > > > > > > > > > > Can you please elaborate why, isn't the centralized exiting of > > > > > functions preferred kernel coding style? > > > > > https://www.kernel.org/doc/html/v4.11/process/coding-style.html#cent > > > > > ra > > > > > lized-ex > > > > > iting-of-functions > > > > > > > > You exit only from one location (not multiple) and not from a nested > > > > context. Here you just add more complexity by doing this. > > > > > > Where is the complexity ? I see it as a standard way of undoing on exit. > > > Tomas > > > > Jarkko, can you please respond. > > Thanks > > Tomas > > I was away for Mon-Wed last week and did not work on TPM for Thu-Fri. > > My earlier comment was incorrect as there are two locations to exit (not > sure how I managed to overlook the patch that way). > > Thus, I have only two very minor requets: > > * Remove the extra newline (the last line addition in the patch). > * Use just label named out as we have only one exception handler. > > I'll move on to testing, and if it it passes, I can do those updates > myself. > > /Jarkko Tested-by: Jarkko Sakkinen /Jarkko -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html