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Commit 8b485877 authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman
Browse files

fbdev: fix race in device_create 



There is a race from when a device is created with device_create() and
then the drvdata is set with a call to dev_set_drvdata() in which a
sysfs file could be open, yet the drvdata will be NULL, causing all
sorts of bad things to happen.

This patch fixes the problem by using the new function,
device_create_drvdata().

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: James Simmons <jsimmons@infradead.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 19051c50

drivers/video/display/display-sysfs.c

+7 −3
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 
#include <linux/ctype.h>

#include <linux/idr.h>

#include <linux/err.h>

#include <linux/kdev_t.h>



static ssize_t display_show_name(struct device *dev,

				struct device_attribute *attr, char *buf)
@@ -152,10 +153,13 @@ struct display_device *display_device_register(struct display_driver *driver, 
		mutex_unlock(&allocated_dsp_lock);



		if (!ret) {

			new_dev->dev = device_create(display_class, parent, 0,

						"display%d", new_dev->idx);

			new_dev->dev = device_create_drvdata(display_class,

							     parent,

							     MKDEV(0,0),

							     new_dev,

							     "display%d",

							     new_dev->idx);

			if (!IS_ERR(new_dev->dev)) {

				dev_set_drvdata(new_dev->dev, new_dev);

				new_dev->parent = parent;

				new_dev->driver = driver;

				mutex_init(&new_dev->lock);