From: Len Brown <len.brown@intel.com>
Date: Sat, 22 May 2010 20:34:10 +0000 (-0400)
Subject: cpuidle: add cpuidle_unregister_driver() error check
X-Git-Tag: v2.6.35-rc1~19^2~6
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c0d64cb031c21f163a0ec15cf10844bcf0ceedcf;p=thirdparty%2Flinux.git

cpuidle: add cpuidle_unregister_driver() error check

Assure that cpuidle_unregister_driver() will not clobber
the registered driver if unregistered by somebody else.

Signed-off-by: Len Brown <len.brown@intel.com>
---

diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c
index 2257004fe33d5..826b5c0aa12bb 100644
--- a/drivers/cpuidle/driver.c
+++ b/drivers/cpuidle/driver.c
@@ -45,8 +45,11 @@ EXPORT_SYMBOL_GPL(cpuidle_register_driver);
  */
 void cpuidle_unregister_driver(struct cpuidle_driver *drv)
 {
-	if (!drv)
+	if (drv != cpuidle_curr_driver) {
+		WARN(1, "invalid cpuidle_unregister_driver(%s)\n",
+			drv->name);
 		return;
+	}
 
 	spin_lock(&cpuidle_driver_lock);
 	cpuidle_curr_driver = NULL;