Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934544AbZJJPmB (ORCPT ); Sat, 10 Oct 2009 11:42:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761790AbZJJPhW (ORCPT ); Sat, 10 Oct 2009 11:37:22 -0400 Received: from www.tglx.de ([62.245.132.106]:55288 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761740AbZJJPhU (ORCPT ); Sat, 10 Oct 2009 11:37:20 -0400 Message-Id: <20091010153349.113570550@linutronix.de> User-Agent: quilt/0.47-1 Date: Sat, 10 Oct 2009 15:35:28 -0000 From: Thomas Gleixner To: LKML Cc: Andrew Morton , Ingo Molnar , Peter Zijlstra , Frederic Weisbecker , Vincent Sanders , John Kacur , Jonathan Corbet , Christoph Hellwig , Mark Gross Subject: [patch 02/28] pm_qos: clean up racy global "name" variable References: <20091010153314.827301943@linutronix.de> Content-Disposition: inline; filename=pm-qos-cleanup-racy-name-variable.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2518 Lines: 71 "name" is a poor name for a file-global variable. It was used in three different functions, with no mutual exclusion. But it's just a tiny, temporary string; let's just move it onto the stack in the functions that need it. Also use snprintf() just in case. Signed-off-by: Jonathan Corbet Cc: Mark Gross Reviewed-by: Frederic Weisbecker Signed-off-by: Thomas Gleixner diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c index d96b83e..3db49b9 100644 --- a/kernel/pm_qos_params.c +++ b/kernel/pm_qos_params.c @@ -343,18 +343,18 @@ int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier) } EXPORT_SYMBOL_GPL(pm_qos_remove_notifier); -#define PID_NAME_LEN sizeof("process_1234567890") -static char name[PID_NAME_LEN]; +#define PID_NAME_LEN 32 static int pm_qos_power_open(struct inode *inode, struct file *filp) { int ret; long pm_qos_class; + char name[PID_NAME_LEN]; pm_qos_class = find_pm_qos_object_by_minor(iminor(inode)); if (pm_qos_class >= 0) { filp->private_data = (void *)pm_qos_class; - sprintf(name, "process_%d", current->pid); + snprintf(name, PID_NAME_LEN, "process_%d", current->pid); ret = pm_qos_add_requirement(pm_qos_class, name, PM_QOS_DEFAULT_VALUE); if (ret >= 0) @@ -366,9 +366,10 @@ static int pm_qos_power_open(struct inode *inode, struct file *filp) static int pm_qos_power_release(struct inode *inode, struct file *filp) { int pm_qos_class; + char name[PID_NAME_LEN]; pm_qos_class = (long)filp->private_data; - sprintf(name, "process_%d", current->pid); + snprintf(name, PID_NAME_LEN, "process_%d", current->pid); pm_qos_remove_requirement(pm_qos_class, name); return 0; @@ -379,13 +380,14 @@ static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, { s32 value; int pm_qos_class; + char name[PID_NAME_LEN]; pm_qos_class = (long)filp->private_data; if (count != sizeof(s32)) return -EINVAL; if (copy_from_user(&value, buf, sizeof(s32))) return -EFAULT; - sprintf(name, "process_%d", current->pid); + snprintf(name, PID_NAME_LEN, "process_%d", current->pid); pm_qos_update_requirement(pm_qos_class, name, value); return sizeof(s32); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/