Merge tag 'livepatching-for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching

Pull livepatching updates from Petr Mladek:

 - New API to track system state changes done be livepatch callbacks. It
   helps to maintain compatibility between livepatches.

 - Update Kconfig help text. ORC is another reliable unwinder.

 - Disable generic selftest timeout. Livepatch selftests have their own
   per-operation fine-grained timeouts.

* tag 'livepatching-for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching:
  x86/stacktrace: update kconfig help text for reliable unwinders
  livepatch: Selftests of the API for tracking system state changes
  livepatch: Documentation of the new API for tracking system state changes
  livepatch: Allow to distinguish different version of system state changes
  livepatch: Basic API to track system state changes
  livepatch: Keep replaced patches until post_patch callback is called
  selftests/livepatch: Disable the timeout

1 files changed, 17 insertions, 0 deletions

diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h
index 273400814020..e894e74905f3 100644
--- a/include/linux/livepatch.h
+++ b/include/linux/livepatch.h
@@ -131,9 +131,22 @@ struct klp_object {
 };
 
 /**
+ * struct klp_state - state of the system modified by the livepatch
+ * @id:		system state identifier (non-zero)
+ * @version:	version of the change
+ * @data:	custom data
+ */
+struct klp_state {
+	unsigned long id;
+	unsigned int version;
+	void *data;
+};
+
+/**
  * struct klp_patch - patch structure for live patching
  * @mod:	reference to the live patch module
  * @objs:	object entries for kernel objects to be patched
+ * @states:	system states that can get modified
  * @replace:	replace all actively used patches
  * @list:	list node for global list of actively used patches
  * @kobj:	kobject for sysfs resources
@@ -147,6 +160,7 @@ struct klp_patch {
 	/* external */
 	struct module *mod;
 	struct klp_object *objs;
+	struct klp_state *states;
 	bool replace;
 
 	/* internal */
@@ -217,6 +231,9 @@ void *klp_shadow_get_or_alloc(void *obj, unsigned long id,
 void klp_shadow_free(void *obj, unsigned long id, klp_shadow_dtor_t dtor);
 void klp_shadow_free_all(unsigned long id, klp_shadow_dtor_t dtor);
 
+struct klp_state *klp_get_state(struct klp_patch *patch, unsigned long id);
+struct klp_state *klp_get_prev_state(unsigned long id);
+
 #else /* !CONFIG_LIVEPATCH */
 
 static inline int klp_module_coming(struct module *mod) { return 0; }