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authorJonathan Corbet <corbet@lwn.net>2008-08-26 17:15:45 -0600
committerJonathan Corbet <corbet@lwn.net>2008-10-16 12:32:26 -0600
commit0d4a7bc12ffecd3ba41dd94179cc5b272b71ce8a (patch)
tree40fb095468564e1bcd64ee9a01ac409406cc36d3
parent3fa8749e584b55f1180411ab1b51117190bac1e5 (diff)
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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: Hans J. Koch <hjk@linutronix.de> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
-rw-r--r--drivers/uio/uio.c14
1 files changed, 8 insertions, 6 deletions
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index 3a6934bf7131..4f28f4bf8366 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -47,6 +47,9 @@ static struct uio_class {
struct class *class;
} *uio_class;
+/* Protect idr accesses */
+static DEFINE_MUTEX(minor_lock);
+
/*
* 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 DEFINE_MUTEX(minor_lock);
int retval = -ENOMEM;
int id;
@@ -253,7 +255,9 @@ exit:
static void uio_free_minor(struct uio_device *idev)
{
+ mutex_lock(&minor_lock);
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;
int ret = 0;
- lock_kernel();
+ mutex_lock(&minor_lock);
idev = idr_find(&uio_idr, iminor(inode));
+ mutex_unlock(&minor_lock);
if (!idev) {
ret = -ENODEV;
goto out;
@@ -324,18 +329,15 @@ static int uio_open(struct inode *inode, struct file *filep)
if (ret)
goto err_infoopen;
}
- unlock_kernel();
return 0;
err_infoopen:
-
kfree(listener);
-err_alloc_listener:
+err_alloc_listener:
module_put(idev->owner);
out:
- unlock_kernel();
return ret;
}