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Commit 0d4a7bc1 authored by Jonathan Corbet's avatar Jonathan Corbet
Browse files

UIO: BKL removal 



Fill in needed locking around idr accesses, then remove the big kernel lock
from the UIO driver.  Since there are no in-tree UIO drivers with open()
methods, no further BKL pushdown is required.

Acked-by: default avatarHans J. Koch <hjk@linutronix.de>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
parent 3fa8749e

drivers/uio/uio.c

+8 −6
Original line number Original line Diff line number Diff line
@@ -47,6 +47,9 @@ static struct uio_class { 
	struct class *class;

	struct class *class;

} *uio_class;

} *uio_class;





/* Protect idr accesses */

static DEFINE_MUTEX(minor_lock);



/*

/*

 * attributes

 * attributes

 */

 */
@@ -231,7 +234,6 @@ static void uio_dev_del_attributes(struct uio_device *idev) 




static int uio_get_minor(struct uio_device *idev)

static int uio_get_minor(struct uio_device *idev)

{

{

	static DEFINE_MUTEX(minor_lock);

	int retval = -ENOMEM;

	int retval = -ENOMEM;

	int id;

	int id;
@@ -253,7 +255,9 @@ exit: 




static void uio_free_minor(struct uio_device *idev)

static void uio_free_minor(struct uio_device *idev)

{

{

	mutex_lock(&minor_lock);

	idr_remove(&uio_idr, idev->minor);

	idr_remove(&uio_idr, idev->minor);

	mutex_unlock(&minor_lock);

}

}





/**

/**
@@ -297,8 +301,9 @@ static int uio_open(struct inode *inode, struct file *filep) 
	struct uio_listener *listener;

	struct uio_listener *listener;

	int ret = 0;

	int ret = 0;





	lock_kernel();

	mutex_lock(&minor_lock);

	idev = idr_find(&uio_idr, iminor(inode));

	idev = idr_find(&uio_idr, iminor(inode));

	mutex_unlock(&minor_lock);

	if (!idev) {

	if (!idev) {

		ret = -ENODEV;

		ret = -ENODEV;

		goto out;

		goto out;
@@ -324,18 +329,15 @@ static int uio_open(struct inode *inode, struct file *filep) 
		if (ret)

		if (ret)

			goto err_infoopen;

			goto err_infoopen;

	}

	}

	unlock_kernel();

	return 0;

	return 0;





err_infoopen:

err_infoopen:



	kfree(listener);

	kfree(listener);

err_alloc_listener:





err_alloc_listener:

	module_put(idev->owner);

	module_put(idev->owner);





out:

out:

	unlock_kernel();

	return ret;

	return ret;

}

}