tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
staging: android: timed_output: fix sysfs file creation race
The sysfs file for the driver was being created _after_ the device was
announced to userspace, causing a race with any tools looking for sysfs
files.
Fix the race by using the default attribute group for the class.
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+10
-17
+10
-17
drivers/staging/android/timed_output.c
+10
-17
drivers/staging/android/timed_output.c
···
28
28
static atomic_t device_count;
29
29
30
30
static ssize_t enable_show(struct device *dev, struct device_attribute *attr,
31
-
char *buf)
31
+
char *buf)
32
32
{
33
33
struct timed_output_dev *tdev = dev_get_drvdata(dev);
34
34
int remaining = tdev->get_time(tdev);
···
36
36
return sprintf(buf, "%d\n", remaining);
37
37
}
38
38
39
-
static ssize_t enable_store(
40
-
struct device *dev, struct device_attribute *attr,
41
-
const char *buf, size_t size)
39
+
static ssize_t enable_store(struct device *dev, struct device_attribute *attr,
40
+
const char *buf, size_t size)
42
41
{
43
42
struct timed_output_dev *tdev = dev_get_drvdata(dev);
44
43
int value;
···
49
50
50
51
return size;
51
52
}
53
+
static DEVICE_ATTR_RW(enable);
52
54
53
-
static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR, enable_show, enable_store);
55
+
static struct attribute *timed_output_attrs[] = {
56
+
&dev_attr_enable.attr,
57
+
NULL,
58
+
};
59
+
ATTRIBUTE_GROUPS(timed_output);
54
60
55
61
static int create_timed_output_class(void)
56
62
{
···
64
60
if (IS_ERR(timed_output_class))
65
61
return PTR_ERR(timed_output_class);
66
62
atomic_set(&device_count, 0);
63
+
timed_output_class->dev_groups = timed_output_groups;
67
64
}
68
65
69
66
return 0;
···
87
82
if (IS_ERR(tdev->dev))
88
83
return PTR_ERR(tdev->dev);
89
84
90
-
ret = device_create_file(tdev->dev, &dev_attr_enable);
91
-
if (ret < 0)
92
-
goto err_create_file;
93
-
94
85
dev_set_drvdata(tdev->dev, tdev);
95
86
tdev->state = 0;
96
87
return 0;
97
-
98
-
err_create_file:
99
-
device_destroy(timed_output_class, MKDEV(0, tdev->index));
100
-
pr_err("failed to register driver %s\n",
101
-
tdev->name);
102
-
103
-
return ret;
104
88
}
105
89
EXPORT_SYMBOL_GPL(timed_output_dev_register);
106
90
107
91
void timed_output_dev_unregister(struct timed_output_dev *tdev)
108
92
{
109
93
tdev->enable(tdev, 0);
110
-
device_remove_file(tdev->dev, &dev_attr_enable);
111
94
device_destroy(timed_output_class, MKDEV(0, tdev->index));
112
95
dev_set_drvdata(tdev->dev, NULL);
113
96
}