[PATCH] chardev: set variable ret to -EBUSY before checking minor range overlap
From: Chengguang Xu
Date: Fri Apr 05 2019 - 09:53:54 EST
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 chekcking
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@xxxxxxxxxx>
Signed-off-by: Chengguang Xu <cgxu519@xxxxxxx>
---
fs/char_dev.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/char_dev.c b/fs/char_dev.c
index df6a54045ac4..00dfe17871ac 100644
--- a/fs/char_dev.c
+++ b/fs/char_dev.c
@@ -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)
--
2.17.2