hwlat-Fix-Kconfig-and-check-kthread_stop-result.patch

From 605886995a0b84fa23876c1d99485743ef2eef99 Mon Sep 17 00:00:00 2001
From: Jon Masters <jcm@jonmasters.org>
Date: Thu, 22 Oct 2009 19:33:56 +0200
Subject: [PATCH] hwlat: Fix Kconfig and check kthread_stop result

commit d9a4a1d04d0b5ba138a6a5b25013187d4614de4d in tip.

Signed-off-by: Jon Masters <jcm@jonmasters.org>
Signed-off-by: John Kacur <jkacur@redhat.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 drivers/misc/Kconfig          |    2 +-
 drivers/misc/hwlat_detector.c |   12 ++++++++++--
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 125e995..2d883bb 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -93,7 +93,7 @@ config IBM_ASM
 config HWLAT_DETECTOR
 	tristate "Testing module to detect hardware-induced latencies"
 	depends on DEBUG_FS
-	select RING_BUFFER
+	depends on RING_BUFFER
 	default m
 	---help---
 	  A simple hardware latency detector. Use this module to detect
diff --git a/drivers/misc/hwlat_detector.c b/drivers/misc/hwlat_detector.c
index be6553f..d9549e9 100644
--- a/drivers/misc/hwlat_detector.c
+++ b/drivers/misc/hwlat_detector.c
@@ -607,7 +607,11 @@ static ssize_t  debug_enable_fwrite(struct file *filp,
 		if (!enabled)
 			goto unlock;
 		enabled = 0;
-		stop_kthread();
+		err = stop_kthread();
+		if (err) {
+			printk(KERN_ERR BANNER "cannot stop kthread\n");
+			return -EFAULT;
+		}
 		wake_up(&data.wq);		/* reader(s) should return */
 	}
 unlock:
@@ -1194,9 +1198,13 @@ out:
  */
 static void detector_exit(void)
 {
+	int err;
+
 	if (enabled) {
 		enabled = 0;
-		stop_kthread();
+		err = stop_kthread();
+		if (err)
+			printk(KERN_ERR BANNER "cannot stop kthread\n");
 	}
 
 	free_debugfs();
-- 
1.7.0.4