liveupdate: make unregister functions return void

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.

Link: https://lore.kernel.org/20260327033335.696621-10-pasha.tatashin@soleen.com
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Pratyush Yadav (Google) <pratyush@kernel.org>
Cc: David Matlack <dmatlack@google.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Samiullah Khawaja <skhawaja@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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 4060b6064248..0730865711c1 100644
--- a/kernel/liveupdate/luo_file.c
+++ b/kernel/liveupdate/luo_file.c
@@ -912,25 +912,15 @@ err_unlock:
  *
  * 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 e069d694163e..00f5494812c4 100644
--- a/kernel/liveupdate/luo_flb.c
+++ b/kernel/liveupdate/luo_flb.c
@@ -475,21 +475,16 @@ 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;
 }
 
 /**