From: Zijun Hu <zijun.hu@oss.qualcomm.com>
misc_deregister() frees dynamic minor @misc->minor but does not reset it
and cause kunit test case miscdev_test_dynamic_reentry() failure:
| Invalid fixed minor 257 for miscdevice 'miscdyn_a'
| #miscdev_test_dynamic_reentry: ASSERTION FAILED at misc_minor_kunit.c:639
| Expected ret == 0, but
| ret == -22 (0xffffffffffffffea)
| [FAILED] miscdev_test_dynamic_reentry
misc_register()/misc_deregister() are sometimes invoked by driver's
probe()/remove() separately, which has reentry requirement.
Fix by resetting @misc->minor to MISC_DYNAMIC_MINOR in misc_deregister()
as error handling of misc_register() does.
Signed-off-by: Zijun Hu <zijun.hu@oss.qualcomm.com>
---
drivers/char/misc.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/char/misc.c b/drivers/char/misc.c
index b8e66466184fa21fb66d968db7950e0b5669ac43..96ed343cf5c8509a09855020049a9af82a3ede95 100644
--- a/drivers/char/misc.c
+++ b/drivers/char/misc.c
@@ -288,6 +288,8 @@ void misc_deregister(struct miscdevice *misc)
list_del(&misc->list);
device_destroy(&misc_class, MKDEV(MISC_MAJOR, misc->minor));
misc_minor_free(misc->minor);
+ if (misc->minor > MISC_DYNAMIC_MINOR)
+ misc->minor = MISC_DYNAMIC_MINOR;
mutex_unlock(&misc_mtx);
}
EXPORT_SYMBOL(misc_deregister);
--
2.34.1