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UIO: BKL removal

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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: Hans J. Koch <hjk@linutronix.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit is contained in:
Jonathan Corbet 2008-08-26 17:15:45 -06:00
parent 3fa8749e58
commit 0d4a7bc12f
1 changed files with 8 additions and 6 deletions
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14
drivers/uio/uio.c
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@ -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;
} }