chardev: set variable ret to -EBUSY before checking minor range overlap

When allocating dynamic major, the minor range overlap check
in __register_chrdev_region() will not fail, so actually
there is no real case to passing non negative error code to
caller. However, set variable ret to -EBUSY before checking
minor range overlap will avoid false-positive warning from
code analyzing tool(like Smatch) and also make the code more
easy to understand.

Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Chengguang Xu <cgxu519@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Chengguang Xu 2019-05-02 20:15:05 +08:00 committed by Greg Kroah-Hartman
parent 17aa207e6e
commit 7ef0b15244

View File

@ -98,7 +98,7 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor,
int minorct, const char *name)
{
struct char_device_struct *cd, *curr, *prev = NULL;
int ret = -EBUSY;
int ret;
int i;
if (major >= CHRDEV_MAJOR_MAX) {
@ -129,6 +129,7 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor,
major = ret;
}
ret = -EBUSY;
i = major_to_index(major);
for (curr = chrdevs[i]; curr; prev = curr, curr = curr->next) {
if (curr->major < major)