[067/145] macintosh/therm_adt746x: Fix sysfs attributes lifetime

From: Greg KH
Date: Fri Mar 12 2010 - 19:33:28 EST


2.6.32-stable review patch. If anyone has any objections, please let me know.

----------------
From: Jean Delvare <khali@xxxxxxxxxxxx>

commit 33a470f6d5e1879c26f16f6b34dc09f82d44f6e9 upstream.

Looking at drivers/macintosh/therm_adt746x.c, the sysfs files are
created in thermostat_init() and removed in thermostat_exit(), which
are the driver's init and exit functions. These files are backed-up by
a per-device structure, so it looks like the wrong thing to do: the
sysfs files have a lifetime longer than the data structure that is
backing it up.

I think that sysfs files creation should be moved to the end of
probe_thermostat() and sysfs files removal should be moved to the
beginning of remove_thermostat().

Signed-off-by: Jean Delvare <khali@xxxxxxxxxxxx>
Tested-by: Christian Kujau <lists@xxxxxxxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Colin Leroy <colin@xxxxxxxxxx>
Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
drivers/macintosh/therm_adt746x.c | 34 ++++++++++++++++++++++++----------
1 file changed, 24 insertions(+), 10 deletions(-)

--- a/drivers/macintosh/therm_adt746x.c
+++ b/drivers/macintosh/therm_adt746x.c
@@ -90,6 +90,8 @@ static struct task_struct *thread_therm

static void write_both_fan_speed(struct thermostat *th, int speed);
static void write_fan_speed(struct thermostat *th, int speed, int fan);
+static void thermostat_create_files(void);
+static void thermostat_remove_files(void);

static int
write_reg(struct thermostat* th, int reg, u8 data)
@@ -161,6 +163,8 @@ remove_thermostat(struct i2c_client *cli
struct thermostat *th = i2c_get_clientdata(client);
int i;

+ thermostat_remove_files();
+
if (thread_therm != NULL) {
kthread_stop(thread_therm);
}
@@ -449,6 +453,8 @@ static int probe_thermostat(struct i2c_c
return -ENOMEM;
}

+ thermostat_create_files();
+
return 0;
}

@@ -566,7 +572,6 @@ thermostat_init(void)
struct device_node* np;
const u32 *prop;
int i = 0, offset = 0;
- int err;

np = of_find_node_by_name(NULL, "fan");
if (!np)
@@ -633,6 +638,17 @@ thermostat_init(void)
return -ENODEV;
}

+#ifndef CONFIG_I2C_POWERMAC
+ request_module("i2c-powermac");
+#endif
+
+ return i2c_add_driver(&thermostat_driver);
+}
+
+static void thermostat_create_files(void)
+{
+ int err;
+
err = device_create_file(&of_dev->dev, &dev_attr_sensor1_temperature);
err |= device_create_file(&of_dev->dev, &dev_attr_sensor2_temperature);
err |= device_create_file(&of_dev->dev, &dev_attr_sensor1_limit);
@@ -647,16 +663,9 @@ thermostat_init(void)
if (err)
printk(KERN_WARNING
"Failed to create tempertaure attribute file(s).\n");
-
-#ifndef CONFIG_I2C_POWERMAC
- request_module("i2c-powermac");
-#endif
-
- return i2c_add_driver(&thermostat_driver);
}

-static void __exit
-thermostat_exit(void)
+static void thermostat_remove_files(void)
{
if (of_dev) {
device_remove_file(&of_dev->dev, &dev_attr_sensor1_temperature);
@@ -673,9 +682,14 @@ thermostat_exit(void)
device_remove_file(&of_dev->dev,
&dev_attr_sensor2_fan_speed);

- of_device_unregister(of_dev);
}
+}
+
+static void __exit
+thermostat_exit(void)
+{
i2c_del_driver(&thermostat_driver);
+ of_device_unregister(of_dev);
}

module_init(thermostat_init);


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