HID: remove BKL from hidraw
Remove BKL from hidraw, which is possible through fixing the
locking of minors_lock mutex properly -- it is now used to
guard all accessess to hidraw_table[], preventing it to becoming
NULL unexpectedly by unregistering the device.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c
index d044767..589dac5 100644
--- a/drivers/hid/hidraw.c
+++ b/drivers/hid/hidraw.c
@@ -105,38 +105,48 @@
static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
{
unsigned int minor = iminor(file->f_path.dentry->d_inode);
- /* FIXME: What stops hidraw_table going NULL */
- struct hid_device *dev = hidraw_table[minor]->hid;
+ struct hid_device *dev;
__u8 *buf;
int ret = 0;
- if (!dev->hid_output_raw_report)
- return -ENODEV;
+ mutex_lock(&minors_lock);
+ dev = hidraw_table[minor]->hid;
+
+ if (!dev->hid_output_raw_report) {
+ ret = -ENODEV;
+ goto out;
+ }
if (count > HID_MAX_BUFFER_SIZE) {
printk(KERN_WARNING "hidraw: pid %d passed too large report\n",
task_pid_nr(current));
- return -EINVAL;
+ ret = -EINVAL;
+ goto out;
}
if (count < 2) {
printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
task_pid_nr(current));
- return -EINVAL;
- }
-
- buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
-
- if (copy_from_user(buf, buffer, count)) {
- ret = -EFAULT;
+ ret = -EINVAL;
goto out;
}
+ buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
+ if (!buf) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if (copy_from_user(buf, buffer, count)) {
+ ret = -EFAULT;
+ goto out_free;
+ }
+
ret = dev->hid_output_raw_report(dev, buf, count, HID_OUTPUT_REPORT);
-out:
+out_free:
kfree(buf);
+out:
+ mutex_unlock(&minors_lock);
return ret;
}
@@ -164,7 +174,6 @@
goto out;
}
- lock_kernel();
mutex_lock(&minors_lock);
if (!hidraw_table[minor]) {
printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n",
@@ -196,7 +205,6 @@
out_unlock:
mutex_unlock(&minors_lock);
- unlock_kernel();
out:
return err;
@@ -237,11 +245,12 @@
struct inode *inode = file->f_path.dentry->d_inode;
unsigned int minor = iminor(inode);
long ret = 0;
- /* FIXME: What stops hidraw_table going NULL */
- struct hidraw *dev = hidraw_table[minor];
+ struct hidraw *dev;
void __user *user_arg = (void __user*) arg;
- lock_kernel();
+ mutex_lock(&minors_lock);
+ dev = hidraw_table[minor];
+
switch (cmd) {
case HIDIOCGRDESCSIZE:
if (put_user(dev->hid->rsize, (int __user *)arg))
@@ -314,7 +323,7 @@
ret = -ENOTTY;
}
- unlock_kernel();
+ mutex_unlock(&minors_lock);
return ret;
}
