To ensure that unregistration is always successful and doesn't leave
dangling resources, introduce auto-unregistration of FLBs: when a file
handler is unregistered, all FLBs associated with it are automatically
unregistered.
Introduce a new helper luo_flb_unregister_all() which unregisters all
FLBs linked to the given file handler.
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
---
kernel/liveupdate/luo_file.c | 17 +-----
kernel/liveupdate/luo_flb.c | 93 ++++++++++++++++++++------------
kernel/liveupdate/luo_internal.h | 1 +
3 files changed, 61 insertions(+), 50 deletions(-)
diff --git a/kernel/liveupdate/luo_file.c b/kernel/liveupdate/luo_file.c
index c0ce08d55747..b9ba1b8dce84 100644
--- a/kernel/liveupdate/luo_file.c
+++ b/kernel/liveupdate/luo_file.c
@@ -873,15 +873,6 @@ 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)
{
@@ -891,15 +882,9 @@ int liveupdate_unregister_file_handler(struct liveupdate_file_handler *fh)
liveupdate_test_unregister(fh);
scoped_guard(rwsem_write, &luo_file_handler_lock) {
- if (!list_empty(&ACCESS_PRIVATE(fh, flb_list)))
- goto err_register;
-
+ luo_flb_unregister_all(fh);
list_del(&ACCESS_PRIVATE(fh, list));
}
return 0;
-
-err_register:
- liveupdate_test_register(fh);
- return -EBUSY;
}
diff --git a/kernel/liveupdate/luo_flb.c b/kernel/liveupdate/luo_flb.c
index 8bbe11a7286b..5b61c0844a49 100644
--- a/kernel/liveupdate/luo_flb.c
+++ b/kernel/liveupdate/luo_flb.c
@@ -316,6 +316,64 @@ void luo_flb_file_finish(struct liveupdate_file_handler *fh)
luo_flb_file_finish_one(iter->flb);
}
+static void luo_flb_unregister_one(struct liveupdate_file_handler *fh,
+ struct liveupdate_flb *flb)
+{
+ struct luo_flb_private *private = luo_flb_get_private(flb);
+ struct list_head *flb_list = &ACCESS_PRIVATE(fh, flb_list);
+ struct luo_flb_link *iter;
+ bool found = false;
+
+ /* Find and remove the link from the file handler's list */
+ list_for_each_entry(iter, flb_list, list) {
+ if (iter->flb == flb) {
+ list_del(&iter->list);
+ kfree(iter);
+ found = true;
+ break;
+ }
+ }
+
+ if (!found) {
+ pr_warn("Failed to unregister FLB '%s': not found in file handler '%s'\n",
+ flb->compatible, fh->compatible);
+ return;
+ }
+
+ private->users--;
+
+ /*
+ * If this is the last file-handler with which we are registred, remove
+ * from the global list.
+ */
+ if (!private->users) {
+ list_del_init(&private->list);
+ luo_flb_global.count--;
+ }
+}
+
+/**
+ * luo_flb_unregister_all - Unregister all FLBs associated with a file handler.
+ * @fh: The file handler whose FLBs should be unregistered.
+ *
+ * This function iterates through the list of FLBs associated with the given
+ * file handler and unregisters them all one by one.
+ */
+void luo_flb_unregister_all(struct liveupdate_file_handler *fh)
+{
+ struct list_head *flb_list = &ACCESS_PRIVATE(fh, flb_list);
+ struct luo_flb_link *iter, *tmp;
+
+ if (!liveupdate_enabled())
+ return;
+
+ guard(rwsem_write)(&luo_flb_lock);
+ guard(rwsem_write)(&ACCESS_PRIVATE(fh, flb_lock));
+
+ list_for_each_entry_safe(iter, tmp, flb_list, list)
+ luo_flb_unregister_one(fh, iter->flb);
+}
+
/**
* liveupdate_register_flb - Associate an FLB with a file handler and register it globally.
* @fh: The file handler that will now depend on the FLB.
@@ -417,50 +475,17 @@ int liveupdate_register_flb(struct liveupdate_file_handler *fh,
* the FLB is removed from the global registry and the reference to its
* owner module (acquired during registration) is released.
*
- * Context: This function ensures the session is quiesced (no active FDs
- * being created) during the update. It is typically called from a
- * subsystem's module exit function.
- * Return: 0 on success.
- * -EOPNOTSUPP if live update is disabled.
- * -EBUSY if the live update session is active and cannot be quiesced.
- * -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)
{
- struct luo_flb_private *private = luo_flb_get_private(flb);
- struct list_head *flb_list = &ACCESS_PRIVATE(fh, flb_list);
- struct luo_flb_link *iter;
- int err = -ENOENT;
-
if (!liveupdate_enabled())
return -EOPNOTSUPP;
guard(rwsem_write)(&luo_flb_lock);
guard(rwsem_write)(&ACCESS_PRIVATE(fh, flb_lock));
- /* Find and remove the link from the file handler's list */
- list_for_each_entry(iter, flb_list, list) {
- if (iter->flb == flb) {
- list_del(&iter->list);
- kfree(iter);
- err = 0;
- break;
- }
- }
-
- if (err)
- return err;
-
- private->users--;
- /*
- * If this is the last file-handler with which we are registred, remove
- * from the global list.
- */
- if (!private->users) {
- list_del_init(&private->list);
- luo_flb_global.count--;
- }
+ luo_flb_unregister_one(fh, flb);
return 0;
}
diff --git a/kernel/liveupdate/luo_internal.h b/kernel/liveupdate/luo_internal.h
index ec949f91c8c1..730c3faa7616 100644
--- a/kernel/liveupdate/luo_internal.h
+++ b/kernel/liveupdate/luo_internal.h
@@ -101,6 +101,7 @@ void luo_file_set_destroy(struct luo_file_set *file_set);
int luo_flb_file_preserve(struct liveupdate_file_handler *fh);
void luo_flb_file_unpreserve(struct liveupdate_file_handler *fh);
void luo_flb_file_finish(struct liveupdate_file_handler *fh);
+void luo_flb_unregister_all(struct liveupdate_file_handler *fh);
int __init luo_flb_setup_outgoing(void *fdt);
int __init luo_flb_setup_incoming(void *fdt);
void luo_flb_serialize(void);
--
2.53.0.851.ga537e3e6e9-goog