diff options
| -rw-r--r-- | kernel/livepatch/core.c | 36 | ||||
| -rw-r--r-- | kernel/livepatch/core.h | 5 | ||||
| -rw-r--r-- | kernel/livepatch/transition.c | 12 |
3 files changed, 35 insertions, 18 deletions
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index ab4a4606d19b..1e1d87ead55c 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -632,7 +632,7 @@ static void klp_free_objects_dynamic(struct klp_patch *patch) * 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); @@ -677,6 +677,23 @@ static void klp_free_patch_work_fn(struct work_struct *work) 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) @@ -1022,12 +1039,13 @@ err: 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. @@ -1035,18 +1053,16 @@ EXPORT_SYMBOL_GPL(klp_enable_patch); * 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); } } diff --git a/kernel/livepatch/core.h b/kernel/livepatch/core.h index ec43a40b853f..38209c7361b6 100644 --- a/kernel/livepatch/core.h +++ b/kernel/livepatch/core.h @@ -13,8 +13,9 @@ extern struct list_head klp_patches; #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) diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c index cdf318d86dd6..f6310f848f34 100644 --- a/kernel/livepatch/transition.c +++ b/kernel/livepatch/transition.c @@ -78,7 +78,7 @@ static void klp_complete_transition(void) 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); } @@ -446,14 +446,14 @@ void klp_try_complete_transition(void) 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); } /* |