[PATCH v4 09/11] liveupdate: Make unregister functions return void

Pasha Tatashin
2026-04-13T18:51:42Z

Change liveupdate_unregister_file_handler and liveupdate_unregister_flb
to return void instead of an error code. This follows the design
principle that unregistration during module unload should not fail,
as the unload cannot be stopped at that point.

Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Pratyush Yadav (Google) <pratyush@kernel.org>
---
include/linux/liveupdate.h | 14 ++++++--------
kernel/liveupdate/luo_file.c | 14 ++------------
kernel/liveupdate/luo_flb.c | 11 +++--------
3 files changed, 11 insertions(+), 28 deletions(-)

diff --git a/include/linux/liveupdate.h b/include/linux/liveupdate.h
index 9c761d9bacf8..30c5a39ff9e9 100644
--- a/include/linux/liveupdate.h
+++ b/include/linux/liveupdate.h
@@ -231,12 +231,12 @@ bool liveupdate_enabled(void);
int liveupdate_reboot(void);

int liveupdate_register_file_handler(struct liveupdate_file_handler *fh);
-int liveupdate_unregister_file_handler(struct liveupdate_file_handler *fh);
+void liveupdate_unregister_file_handler(struct liveupdate_file_handler *fh);

int liveupdate_register_flb(struct liveupdate_file_handler *fh,
struct liveupdate_flb *flb);
-int liveupdate_unregister_flb(struct liveupdate_file_handler *fh,
- struct liveupdate_flb *flb);
+void liveupdate_unregister_flb(struct liveupdate_file_handler *fh,
+ struct liveupdate_flb *flb);

int liveupdate_flb_get_incoming(struct liveupdate_flb *flb, void **objp);
int liveupdate_flb_get_outgoing(struct liveupdate_flb *flb, void **objp);
@@ -258,9 +258,8 @@ static inline int liveupdate_register_file_handler(struct liveupdate_file_handle
return -EOPNOTSUPP;
}

-static inline int liveupdate_unregister_file_handler(struct liveupdate_file_handler *fh)
+static inline void liveupdate_unregister_file_handler(struct liveupdate_file_handler *fh)
{
- return -EOPNOTSUPP;
}

static inline int liveupdate_register_flb(struct liveupdate_file_handler *fh,
@@ -269,10 +268,9 @@ static inline int liveupdate_register_flb(struct liveupdate_file_handler *fh,
return -EOPNOTSUPP;
}

-static inline int liveupdate_unregister_flb(struct liveupdate_file_handler *fh,
- struct liveupdate_flb *flb)
+static inline void liveupdate_unregister_flb(struct liveupdate_file_handler *fh,
+ struct liveupdate_flb *flb)
{
- return -EOPNOTSUPP;
}

static inline int liveupdate_flb_get_incoming(struct liveupdate_flb *flb,
diff --git a/kernel/liveupdate/luo_file.c b/kernel/liveupdate/luo_file.c
index f3b7bb698d3b..f8e098858c62 100644
--- a/kernel/liveupdate/luo_file.c
+++ b/kernel/liveupdate/luo_file.c
@@ -915,25 +915,15 @@ int liveupdate_register_file_handler(struct liveupdate_file_handler *fh)
*
* Unregisters the file handler from the liveupdate core. This function
* reverses the operations of liveupdate_register_file_handler().
- *
- * It ensures safe removal by checking that:
- * No FLB registered with this file handler.
- *
- * If the unregistration fails, the internal test state is reverted.
- *
- * Return: 0 Success. -EOPNOTSUPP when live update is not enabled. -EBUSY A live
- * update is in progress, FLB is registred with this file handler.
*/
-int liveupdate_unregister_file_handler(struct liveupdate_file_handler *fh)
+void liveupdate_unregister_file_handler(struct liveupdate_file_handler *fh)
{
if (!liveupdate_enabled())
- return -EOPNOTSUPP;
+ return;

guard(rwsem_write)(&luo_register_rwlock);
luo_flb_unregister_all(fh);
list_del(&ACCESS_PRIVATE(fh, list));

module_put(fh->ops->owner);
-
- return 0;
}
diff --git a/kernel/liveupdate/luo_flb.c b/kernel/liveupdate/luo_flb.c
index b9f5d452a998..42c37b3c2101 100644
--- a/kernel/liveupdate/luo_flb.c
+++ b/kernel/liveupdate/luo_flb.c
@@ -476,21 +476,16 @@ int liveupdate_register_flb(struct liveupdate_file_handler *fh,
* owner module (acquired during registration) is released.
*
* Context: It is typically called from a subsystem's module exit function.
- * Return: 0 on success.
- * -EOPNOTSUPP if live update is disabled.
- * -ENOENT if the FLB was not found in the file handler's list.
*/
-int liveupdate_unregister_flb(struct liveupdate_file_handler *fh,
- struct liveupdate_flb *flb)
+void liveupdate_unregister_flb(struct liveupdate_file_handler *fh,
+ struct liveupdate_flb *flb)
{
if (!liveupdate_enabled())
- return -EOPNOTSUPP;
+ return;

guard(rwsem_write)(&luo_register_rwlock);

luo_flb_unregister_one(fh, flb);
-
- return 0;
}

/**
--
2.43.0