From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754989AbeDTNTW (ORCPT ); Fri, 20 Apr 2018 09:19:22 -0400 Received: from mga04.intel.com ([192.55.52.120]:60647 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754966AbeDTNTR (ORCPT ); Fri, 20 Apr 2018 09:19:17 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,301,1520924400"; d="scan'208";a="52318329" From: "Winkler, Tomas" To: "'Jarkko Sakkinen'" , "'Jason Gunthorpe'" CC: "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. Thread-Topic: [PATCH] tpm: tpm_crb: relinquish locality on error path. Thread-Index: AQHTzovCXbr+Xqq9jkSj9yBS1IttZ6P4GCYAgAGeicCAAAoXAIAAs/uQgA9COvA= Date: Fri, 20 Apr 2018 13:19:12 +0000 Message-ID: <5B8DA87D05A7694D9FA63FD143655C1B942627FD@hasmsx108.ger.corp.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> In-Reply-To: <5B8DA87D05A7694D9FA63FD143655C1B94252945@hasmsx108.ger.corp.intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ctpclassification: CTP_NT x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiYTYxMDJlNTAtYTI3OS00ZjI5LThlYjEtOTE0MzRkOGQ1ZWVjIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX05UIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE3LjIuNS4xOCIsIlRydXN0ZWRMYWJlbEhhc2giOiI2aGZGMWEwOVl4UXpuZlN5N0JCRVRHRGh0d2FhZnpxVXJsRnpqU1M3cFBndkxpQ05UODJZVEVYS2c0TEk2ckhZIn0= dlp-product: dlpe-windows dlp-version: 11.0.0.116 dlp-reaction: no-action x-originating-ip: [10.254.150.163] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id w3KDJOHA024548 > > 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