HID: fix locking in hidraw_open()
As open needs to sleep hidraw was wrong to call it with a spinlock held.
Furthermore, open can of course fail which needs to be handled.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c
index 894d52e..7685ae6 100644
--- a/drivers/hid/hidraw.c
+++ b/drivers/hid/hidraw.c
@@ -38,7 +38,7 @@
static struct cdev hidraw_cdev;
static struct class *hidraw_class;
static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES];
-static DEFINE_SPINLOCK(minors_lock);
+static DEFINE_MUTEX(minors_lock);
static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
{
@@ -159,13 +159,13 @@
struct hidraw_list *list;
int err = 0;
- lock_kernel();
if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
err = -ENOMEM;
goto out;
}
- spin_lock(&minors_lock);
+ lock_kernel();
+ mutex_lock(&minors_lock);
if (!hidraw_table[minor]) {
printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n",
minor);
@@ -180,13 +180,16 @@
file->private_data = list;
dev = hidraw_table[minor];
- if (!dev->open++)
- dev->hid->ll_driver->open(dev->hid);
+ if (!dev->open++) {
+ err = dev->hid->ll_driver->open(dev->hid);
+ if (err < 0)
+ dev->open--;
+ }
out_unlock:
- spin_unlock(&minors_lock);
-out:
+ mutex_unlock(&minors_lock);
unlock_kernel();
+out:
return err;
}
@@ -310,7 +313,7 @@
result = -EINVAL;
- spin_lock(&minors_lock);
+ mutex_lock(&minors_lock);
for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
if (hidraw_table[minor])
@@ -320,9 +323,8 @@
break;
}
- spin_unlock(&minors_lock);
-
if (result) {
+ mutex_unlock(&minors_lock);
kfree(dev);
goto out;
}
@@ -331,14 +333,14 @@
NULL, "%s%d", "hidraw", minor);
if (IS_ERR(dev->dev)) {
- spin_lock(&minors_lock);
hidraw_table[minor] = NULL;
- spin_unlock(&minors_lock);
+ mutex_unlock(&minors_lock);
result = PTR_ERR(dev->dev);
kfree(dev);
goto out;
}
+ mutex_unlock(&minors_lock);
init_waitqueue_head(&dev->wait);
INIT_LIST_HEAD(&dev->list);
@@ -360,9 +362,9 @@
hidraw->exist = 0;
- spin_lock(&minors_lock);
+ mutex_lock(&minors_lock);
hidraw_table[hidraw->minor] = NULL;
- spin_unlock(&minors_lock);
+ mutex_unlock(&minors_lock);
device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor));