* The operation must be completed by calling klp_free_patch_finish()
* outside klp_mutex.
*/
-void klp_free_patch_start(struct klp_patch *patch)
+static void klp_free_patch_start(struct klp_patch *patch)
{
if (!list_empty(&patch->list))
list_del(&patch->list);
klp_free_patch_finish(patch);
}
+void klp_free_patch_async(struct klp_patch *patch)
+{
+ klp_free_patch_start(patch);
+ schedule_work(&patch->free_work);
+}
+
+void klp_free_replaced_patches_async(struct klp_patch *new_patch)
+{
+ struct klp_patch *old_patch, *tmp_patch;
+
+ klp_for_each_patch_safe(old_patch, tmp_patch) {
+ if (old_patch == new_patch)
+ return;
+ klp_free_patch_async(old_patch);
+ }
+}
+
static int klp_init_func(struct klp_object *obj, struct klp_func *func)
{
if (!func->old_name)
EXPORT_SYMBOL_GPL(klp_enable_patch);
/*
- * This function removes replaced patches.
+ * This function unpatches objects from the replaced livepatches.
*
* We could be pretty aggressive here. It is called in the situation where
- * these structures are no longer accessible. All functions are redirected
- * by the klp_transition_patch. They use either a new code or they are in
- * the original code because of the special nop function patches.
+ * these structures are no longer accessed from the ftrace handler.
+ * All functions are redirected by the klp_transition_patch. They
+ * use either a new code or they are in the original code because
+ * of the special nop function patches.
*
* The only exception is when the transition was forced. In this case,
* klp_ftrace_handler() might still see the replaced patch on the stack.
* thanks to RCU. We only have to keep the patches on the system. Also
* this is handled transparently by patch->module_put.
*/
-void klp_discard_replaced_patches(struct klp_patch *new_patch)
+void klp_unpatch_replaced_patches(struct klp_patch *new_patch)
{
- struct klp_patch *old_patch, *tmp_patch;
+ struct klp_patch *old_patch;
- klp_for_each_patch_safe(old_patch, tmp_patch) {
+ klp_for_each_patch(old_patch) {
if (old_patch == new_patch)
return;
old_patch->enabled = false;
klp_unpatch_objects(old_patch);
- klp_free_patch_start(old_patch);
- schedule_work(&old_patch->free_work);
}
}
#define klp_for_each_patch(patch) \
list_for_each_entry(patch, &klp_patches, list)
-void klp_free_patch_start(struct klp_patch *patch);
-void klp_discard_replaced_patches(struct klp_patch *new_patch);
+void klp_free_patch_async(struct klp_patch *patch);
+void klp_free_replaced_patches_async(struct klp_patch *new_patch);
+void klp_unpatch_replaced_patches(struct klp_patch *new_patch);
void klp_discard_nops(struct klp_patch *new_patch);
static inline bool klp_is_object_loaded(struct klp_object *obj)
klp_target_state == KLP_PATCHED ? "patching" : "unpatching");
if (klp_transition_patch->replace && klp_target_state == KLP_PATCHED) {
- klp_discard_replaced_patches(klp_transition_patch);
+ klp_unpatch_replaced_patches(klp_transition_patch);
klp_discard_nops(klp_transition_patch);
}
klp_complete_transition();
/*
- * It would make more sense to free the patch in
+ * It would make more sense to free the unused patches in
* klp_complete_transition() but it is called also
* from klp_cancel_transition().
*/
- if (!patch->enabled) {
- klp_free_patch_start(patch);
- schedule_work(&patch->free_work);
- }
+ if (!patch->enabled)
+ klp_free_patch_async(patch);
+ else if (patch->replace)
+ klp_free_replaced_patches_async(patch);
}
/*