From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754490AbcK1IZJ (ORCPT ); Mon, 28 Nov 2016 03:25:09 -0500 Received: from mga05.intel.com ([192.55.52.43]:24997 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754074AbcK1IZB (ORCPT ); Mon, 28 Nov 2016 03:25:01 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,563,1473145200"; d="scan'208";a="791565990" Date: Mon, 28 Nov 2016 16:24:58 +0800 From: Fengguang Wu To: Greg Kroah-Hartman Cc: kbuild-all@01.org, linux-kernel@vger.kernel.org, Julia Lawall Subject: Re: drivers/staging/greybus/bootrom.c:298:35-39: ERROR: fw is NULL but dereferenced. Message-ID: <20161128082458.pe7wfmehxo5rpyxc@wfg-t540p.sh.intel.com> References: <201611270743.Rc4TmNre%fengguang.wu@intel.com> <20161127110633.GA16452@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20161127110633.GA16452@kroah.com> User-Agent: NeoMutt/20161104 (1.7.1) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Nov 27, 2016 at 12:06:33PM +0100, Greg KH wrote: >On Sun, Nov 27, 2016 at 07:11:46AM +0800, kbuild test robot wrote: >> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master >> head: a0d60e62ea5c88a9823410e9d0929a513e29dea2 >> commit: f44dd184634d401f5cf88a6d8b4a60d5ff4f417f Merge greybus driver tree into 4.8-rc6 >> date: 10 weeks ago > >This is a false-positive, sorry. Yes it's a false warning: ret != 0, so fw->size in the if test won't be dereferenced. Relevant code: if (!fw) { dev_err(dev, "%s: firmware not available\n", __func__); ret = -EINVAL; goto unlock; } ... unlock: mutex_unlock(&bootrom->mutex); queue_work: /* Refresh timeout */ if (!ret && (offset + size == fw->size)) next_request = NEXT_REQ_READY_TO_BOOT; else next_request = NEXT_REQ_GET_FIRMWARE; CC Julia for possible improvements to the coccinelle script. If it's not convenient to fix there I'll teach the robot to ignore this particular false warning. Thanks, Fengguang >> coccinelle warnings: (new ones prefixed by >>) >> >> >> drivers/staging/greybus/bootrom.c:298:35-39: ERROR: fw is NULL but dereferenced. >> >> vim +298 drivers/staging/greybus/bootrom.c >> >> 90f1b617 drivers/staging/greybus/firmware.c Viresh Kumar 2015-08-12 282 dev_err(dev, "%s: error allocating response\n", __func__); >> a956d939 drivers/staging/greybus/bootrom.c Viresh Kumar 2016-05-09 283 ret = -ENOMEM; >> a956d939 drivers/staging/greybus/bootrom.c Viresh Kumar 2016-05-09 284 goto unlock; >> 90f1b617 drivers/staging/greybus/firmware.c Viresh Kumar 2015-08-12 285 } >> 90f1b617 drivers/staging/greybus/firmware.c Viresh Kumar 2015-08-12 286 >> 90f1b617 drivers/staging/greybus/firmware.c Viresh Kumar 2015-08-12 287 firmware_response = op->response->payload; >> 98645a9c drivers/staging/greybus/firmware.c Johan Hovold 2015-11-19 288 memcpy(firmware_response->data, fw->data + offset, size); >> 90f1b617 drivers/staging/greybus/firmware.c Viresh Kumar 2015-08-12 289 >> fc41c2da drivers/staging/greybus/firmware.c Eli Sennesh 2016-01-08 290 dev_dbg(dev, "responding with firmware (offs = %u, size = %u)\n", offset, >> fc41c2da drivers/staging/greybus/firmware.c Eli Sennesh 2016-01-08 291 size); >> fc41c2da drivers/staging/greybus/firmware.c Eli Sennesh 2016-01-08 292 >> a956d939 drivers/staging/greybus/bootrom.c Viresh Kumar 2016-05-09 293 unlock: >> a956d939 drivers/staging/greybus/bootrom.c Viresh Kumar 2016-05-09 294 mutex_unlock(&bootrom->mutex); >> a956d939 drivers/staging/greybus/bootrom.c Viresh Kumar 2016-05-09 295 >> a956d939 drivers/staging/greybus/bootrom.c Viresh Kumar 2016-05-09 296 queue_work: >> a956d939 drivers/staging/greybus/bootrom.c Viresh Kumar 2016-05-09 297 /* Refresh timeout */ >> a4293e1d drivers/staging/greybus/bootrom.c Viresh Kumar 2016-06-22 @298 if (!ret && (offset + size == fw->size)) >> a4293e1d drivers/staging/greybus/bootrom.c Viresh Kumar 2016-06-22 299 next_request = NEXT_REQ_READY_TO_BOOT; >> a4293e1d drivers/staging/greybus/bootrom.c Viresh Kumar 2016-06-22 300 else >> a4293e1d drivers/staging/greybus/bootrom.c Viresh Kumar 2016-06-22 301 next_request = NEXT_REQ_GET_FIRMWARE; >> a4293e1d drivers/staging/greybus/bootrom.c Viresh Kumar 2016-06-22 302 >> dbb8cfeb drivers/staging/greybus/bootrom.c Viresh Kumar 2016-06-22 303 gb_bootrom_set_timeout(bootrom, next_request, NEXT_REQ_TIMEOUT_MS); >> a956d939 drivers/staging/greybus/bootrom.c Viresh Kumar 2016-05-09 304 >> a956d939 drivers/staging/greybus/bootrom.c Viresh Kumar 2016-05-09 305 return ret; >> 90f1b617 drivers/staging/greybus/firmware.c Viresh Kumar 2015-08-12 306 } >> >> :::::: The code at line 298 was first introduced by commit >> :::::: a4293e1d4e6416477976ee3bd248589d3fc4bb19 greybus: bootrom: Enhance timeout error message >> >> :::::: TO: Viresh Kumar >> :::::: CC: Greg Kroah-Hartman >> >> --- >> 0-DAY kernel test infrastructure Open Source Technology Center >> https://lists.01.org/pipermail/kbuild-all Intel Corporation