* [PATCH v2] chardev: set variable ret to -EBUSY before checking minor range overlap
@ 2019-05-02 12:15 Chengguang Xu
0 siblings, 0 replies; only message in thread
From: Chengguang Xu @ 2019-05-02 12:15 UTC (permalink / raw)
To: gregkh, dan.carpenter; +Cc: linux-kernel, linux-fsdevel, Chengguang Xu
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>
---
v1->v2:
- Rebase against the latest char-misc-next.
- Modify signed-off mail address.
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 d18cad28c1c3..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
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