From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754333AbYCYIIU (ORCPT ); Tue, 25 Mar 2008 04:08:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753115AbYCYIIF (ORCPT ); Tue, 25 Mar 2008 04:08:05 -0400 Received: from mga11.intel.com ([192.55.52.93]:15634 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752403AbYCYIIB (ORCPT ); Tue, 25 Mar 2008 04:08:01 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.25,551,1199692800"; d="scan'208";a="539483358" Subject: Re: [PATCH 4/5] drivers/acpi: elide a non-zero test on a result that is never 0 From: "Zhang, Rui" To: Julia Lawall Cc: "Brown, Len" , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org In-Reply-To: References: Content-Type: text/plain Date: Tue, 25 Mar 2008 15:50:11 +0800 Message-Id: <1206431411.3047.45.camel@acpi-hp-zz.sh.intel.com> Mime-Version: 1.0 X-Mailer: Evolution 2.12.1 (2.12.1-3.fc8) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2008-03-25 at 02:10 +0800, Julia Lawall wrote: > From: Julia Lawall > > The function thermal_cooling_device_register always returns either a > valid > pointer or a value made with ERR_PTR, so a test for non-zero on the > result > will always succeed. > > The problem was found using the following semantic match. > (http://www.emn.fr/x-info/coccinelle/) > // > @a@ > expression E, E1; > statement S,S1; > position p; > @@ > > E = thermal_cooling_device_register(...) > ... when != E = E1 > if@p (E) S else S1 > > @n@ > position a.p; > expression E,E1; > statement S,S1; > @@ > > E = NULL > ... when != E = E1 > if@p (E) S else S1 > > @depends on !n@ > expression E; > statement S,S1; > position a.p; > @@ > > * if@p (E) > S else S1 > // > > Signed-off-by: Julia Lawall Patch looks correct. Thanks, Julia. But it misses the same problem in driver/misc/intel_menlow.c. And the return value of thermal_zone_device_register is also misused. How about this refreshed patch? :) Check the return value of thermal zone/cooling device registration correctly. Signed-off-by: Zhang Rui --- drivers/acpi/fan.c | 3 +-- drivers/acpi/processor_core.c | 3 +-- drivers/acpi/thermal.c | 2 +- drivers/acpi/video.c | 3 +-- drivers/misc/intel_menlow.c | 4 +--- 5 files changed, 5 insertions(+), 10 deletions(-) Index: linux-2.6/drivers/acpi/fan.c =================================================================== --- linux-2.6.orig/drivers/acpi/fan.c +++ linux-2.6/drivers/acpi/fan.c @@ -259,8 +259,7 @@ static int acpi_fan_add(struct acpi_devi if (IS_ERR(cdev)) { result = PTR_ERR(cdev); goto end; - } - if (cdev) { + } else { printk(KERN_INFO PREFIX "%s is registered as cooling_device%d\n", device->dev.bus_id, cdev->id); Index: linux-2.6/drivers/acpi/processor_core.c =================================================================== --- linux-2.6.orig/drivers/acpi/processor_core.c +++ linux-2.6/drivers/acpi/processor_core.c @@ -673,8 +673,7 @@ static int __cpuinit acpi_processor_star if (IS_ERR(pr->cdev)) { result = PTR_ERR(pr->cdev); goto end; - } - if (pr->cdev) { + } else { printk(KERN_INFO PREFIX "%s is registered as cooling_device%d\n", device->dev.bus_id, pr->cdev->id); Index: linux-2.6/drivers/acpi/thermal.c =================================================================== --- linux-2.6.orig/drivers/acpi/thermal.c +++ linux-2.6/drivers/acpi/thermal.c @@ -1125,7 +1125,7 @@ static int acpi_thermal_register_thermal tz->trips.active[i].flags.valid; i++, trips++); tz->thermal_zone = thermal_zone_device_register("ACPI thermal zone", trips, tz, &acpi_thermal_zone_ops); - if (!tz->thermal_zone) + if (IS_ERR(tz->thermal_zone)) return -ENODEV; result = sysfs_create_link(&tz->device->dev.kobj, Index: linux-2.6/drivers/acpi/video.c =================================================================== --- linux-2.6.orig/drivers/acpi/video.c +++ linux-2.6/drivers/acpi/video.c @@ -733,8 +733,7 @@ static void acpi_video_device_find_cap(s device->dev, &video_cooling_ops); if (IS_ERR(device->cdev)) return; - - if (device->cdev) { + else { printk(KERN_INFO PREFIX "%s is registered as cooling_device%d\n", device->dev->dev.bus_id, device->cdev->id); Index: linux-2.6/drivers/misc/intel_menlow.c =================================================================== --- linux-2.6.orig/drivers/misc/intel_menlow.c +++ linux-2.6/drivers/misc/intel_menlow.c @@ -173,9 +173,7 @@ static int intel_menlow_memory_add(struc if (IS_ERR(cdev)) { result = PTR_ERR(cdev); goto end; - } - - if (cdev) { + } else { acpi_driver_data(device) = cdev; result = sysfs_create_link(&device->dev.kobj, &cdev->device.kobj, "thermal_cooling");