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 d04476700b7b4eb792e41d381a61b535e0666f8f..589dac5b5f569bff93828ea7d18bf3ff6a8e9316 100644 (file)
--- a/drivers/hid/hidraw.c
+++ b/drivers/hid/hidraw.c
@@ -105,38 +105,48 @@ out:
 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;
+               ret = -EINVAL;
+               goto out;
        }
 
        buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
-       if (!buf)
-               return -ENOMEM;
+       if (!buf) {
+               ret = -ENOMEM;
+               goto out;
+       }
 
        if (copy_from_user(buf, buffer, count)) {
                ret = -EFAULT;
-               goto out;
+               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 @@ static int hidraw_open(struct inode *inode, struct file *file)
                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 @@ static int hidraw_open(struct inode *inode, struct file *file)
 
 out_unlock:
        mutex_unlock(&minors_lock);
-       unlock_kernel();
 out:
        return err;
 
@@ -237,11 +245,12 @@ static long hidraw_ioctl(struct file *file, unsigned int cmd,
        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 @@ static long hidraw_ioctl(struct file *file, unsigned int cmd,
 
                ret = -ENOTTY;
        }
-       unlock_kernel();
+       mutex_unlock(&minors_lock);
        return ret;
 }