commit 04a6217df28e3004ba4e76eb0a356a30f72c564f
author Jean Delvare <khali@linux-fr.org> Tue Jun 12 13:57:19 2007 +0200
committer Mark M. Hoffman <mhoffman@lightlink.com> Thu Jul 19 14:22:14 2007 -0400
tree c2361be6f6a778dc769d77aa3e9ebfe0ebea366d
parent ec5e1a4b8faa6a3522171a185a5c6ac9609e14b4

hwmon: Fix a potential race condition on unload

Fix a potential race condition when some hardware monitoring platform
drivers are being unloaded. I believe that the driver data pointer
shouldn't be cleared before all the sysfs files are removed, otherwise
a sysfs callback might attempt to dereference a NULL pointer. I'm not
sure exactly what the driver core protects drivers against, so let's
play it safe.

While we're here, clear the driver data pointer when probe fails, so
as to not leave an invalid pointer behind us.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>

drivers/hwmon/abituguru.c

diff --git a/drivers/hwmon/abituguru.c b/drivers/hwmon/abituguru.c
index bede4d9..11a40da 100644
--- a/drivers/hwmon/abituguru.c
+++ b/drivers/hwmon/abituguru.c
@@ -1287,6 +1287,7 @@
 	for (i = 0; i < ARRAY_SIZE(abituguru_sysfs_attr); i++)
 		device_remove_file(&pdev->dev,
 			&abituguru_sysfs_attr[i].dev_attr);
+	platform_set_drvdata(pdev, NULL);
 	kfree(data);
 	return res;
 }
@@ -1296,13 +1297,13 @@
 	int i;
 	struct abituguru_data *data = platform_get_drvdata(pdev);
 
-	platform_set_drvdata(pdev, NULL);
 	hwmon_device_unregister(data->class_dev);
 	for (i = 0; data->sysfs_attr[i].dev_attr.attr.name; i++)
 		device_remove_file(&pdev->dev, &data->sysfs_attr[i].dev_attr);
 	for (i = 0; i < ARRAY_SIZE(abituguru_sysfs_attr); i++)
 		device_remove_file(&pdev->dev,
 			&abituguru_sysfs_attr[i].dev_attr);
+	platform_set_drvdata(pdev, NULL);
 	kfree(data);
 
 	return 0;

drivers/hwmon/f71805f.c

diff --git a/drivers/hwmon/f71805f.c b/drivers/hwmon/f71805f.c
index e8b1504..8fe4d70 100644
--- a/drivers/hwmon/f71805f.c
+++ b/drivers/hwmon/f71805f.c
@@ -1242,12 +1242,12 @@
 	struct resource *res;
 	int i;
 
-	platform_set_drvdata(pdev, NULL);
 	hwmon_device_unregister(data->class_dev);
 	sysfs_remove_group(&pdev->dev.kobj, &f71805f_group);
 	for (i = 0; i < 4; i++)
 		sysfs_remove_group(&pdev->dev.kobj, &f71805f_group_optin[i]);
 	sysfs_remove_group(&pdev->dev.kobj, &f71805f_group_pwm_freq);
+	platform_set_drvdata(pdev, NULL);
 	kfree(data);
 
 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);

drivers/hwmon/pc87427.c

diff --git a/drivers/hwmon/pc87427.c b/drivers/hwmon/pc87427.c
index 29354fa..2915bc4 100644
--- a/drivers/hwmon/pc87427.c
+++ b/drivers/hwmon/pc87427.c
@@ -484,7 +484,6 @@
 	struct resource *res;
 	int i;
 
-	platform_set_drvdata(pdev, NULL);
 	hwmon_device_unregister(data->class_dev);
 	device_remove_file(&pdev->dev, &dev_attr_name);
 	for (i = 0; i < 8; i++) {
@@ -492,6 +491,7 @@
 			continue;
 		sysfs_remove_group(&pdev->dev.kobj, &pc87427_group_fan[i]);
 	}
+	platform_set_drvdata(pdev, NULL);
 	kfree(data);
 
 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);

drivers/hwmon/smsc47m1.c

diff --git a/drivers/hwmon/smsc47m1.c b/drivers/hwmon/smsc47m1.c
index 9bac3c2..1de2f2b 100644
--- a/drivers/hwmon/smsc47m1.c
+++ b/drivers/hwmon/smsc47m1.c
@@ -597,6 +597,7 @@
 error_remove_files:
 	sysfs_remove_group(&dev->kobj, &smsc47m1_group);
 error_free:
+	platform_set_drvdata(pdev, NULL);
 	kfree(data);
 error_release:
 	release_region(res->start, SMSC_EXTENT);
@@ -608,12 +609,12 @@
 	struct smsc47m1_data *data = platform_get_drvdata(pdev);
 	struct resource *res;
 
-	platform_set_drvdata(pdev, NULL);
 	hwmon_device_unregister(data->class_dev);
 	sysfs_remove_group(&pdev->dev.kobj, &smsc47m1_group);
 
 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
 	release_region(res->start, SMSC_EXTENT);
+	platform_set_drvdata(pdev, NULL);
 	kfree(data);
 
 	return 0;

drivers/hwmon/vt8231.c

diff --git a/drivers/hwmon/vt8231.c b/drivers/hwmon/vt8231.c
index 320d814..c604972 100644
--- a/drivers/hwmon/vt8231.c
+++ b/drivers/hwmon/vt8231.c
@@ -743,6 +743,7 @@
 	sysfs_remove_group(&pdev->dev.kobj, &vt8231_group);
 
 exit_free:
+	platform_set_drvdata(pdev, NULL);
 	kfree(data);
 
 exit_release:

drivers/hwmon/w83627hf.c

diff --git a/drivers/hwmon/w83627hf.c b/drivers/hwmon/w83627hf.c
index cd95360..1ce7817 100644
--- a/drivers/hwmon/w83627hf.c
+++ b/drivers/hwmon/w83627hf.c
@@ -1306,6 +1306,7 @@
 	sysfs_remove_group(&dev->kobj, &w83627hf_group);
 	sysfs_remove_group(&dev->kobj, &w83627hf_group_opt);
       ERROR3:
+	platform_set_drvdata(pdev, NULL);
 	kfree(data);
       ERROR1:
 	release_region(res->start, WINB_REGION_SIZE);
@@ -1318,11 +1319,11 @@
 	struct w83627hf_data *data = platform_get_drvdata(pdev);
 	struct resource *res;
 
-	platform_set_drvdata(pdev, NULL);
 	hwmon_device_unregister(data->class_dev);
 
 	sysfs_remove_group(&pdev->dev.kobj, &w83627hf_group);
 	sysfs_remove_group(&pdev->dev.kobj, &w83627hf_group_opt);
+	platform_set_drvdata(pdev, NULL);
 	kfree(data);
 
 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);