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-rw-r--r--kernel/livepatch/core.c44
1 files changed, 34 insertions, 10 deletions
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index ab4a4606d19b..c3512e7e0801 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -22,6 +22,7 @@
#include <asm/cacheflush.h>
#include "core.h"
#include "patch.h"
+#include "state.h"
#include "transition.h"
/*
@@ -632,7 +633,7 @@ 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 +678,23 @@ 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)
@@ -992,6 +1010,13 @@ int klp_enable_patch(struct klp_patch *patch)
mutex_lock(&klp_mutex);
+ if (!klp_is_patch_compatible(patch)) {
+ pr_err("Livepatch patch (%s) is not compatible with the already installed livepatches.\n",
+ patch->mod->name);
+ mutex_unlock(&klp_mutex);
+ return -EINVAL;
+ }
+
ret = klp_init_patch_early(patch);
if (ret) {
mutex_unlock(&klp_mutex);
@@ -1022,12 +1047,13 @@ 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 +1061,16 @@ 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);
}
}