livepatch: use arch_klp_init_object_loaded() to finish arch-specific tasks

Introduce arch_klp_init_object_loaded() to complete any additional
arch-specific tasks during patching. Architecture code may override this
function.

Signed-off-by: Jessica Yu <jeyu@redhat.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

2 files changed, 16 insertions, 3 deletions

diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h
index a93a0b23dc8d..9072f04db616 100644
--- a/include/linux/livepatch.h
+++ b/include/linux/livepatch.h
@@ -116,6 +116,9 @@ int klp_unregister_patch(struct klp_patch *);
 int klp_enable_patch(struct klp_patch *);
 int klp_disable_patch(struct klp_patch *);
 
+void arch_klp_init_object_loaded(struct klp_patch *patch,
+                                 struct klp_object *obj);
+
 /* Called from the module loader during module coming/going states */
 int klp_module_coming(struct module *mod);
 void klp_module_going(struct module *mod);
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 8bbe50704621..5fbabe022286 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -274,7 +274,6 @@ static int klp_write_object_relocations(struct module *pmod,
 
         objname = klp_is_module(obj) ? obj->name : "vmlinux";
 
-        module_disable_ro(pmod);
         /* For each klp relocation section */
         for (i = 1; i < pmod->klp_info->hdr.e_shnum; i++) {
                 sec = pmod->klp_info->sechdrs + i;
@@ -309,7 +308,6 @@ static int klp_write_object_relocations(struct module *pmod,
                         break;
         }
 
-        module_enable_ro(pmod, true);
         return ret;
 }
 
@@ -763,6 +761,12 @@ static int klp_init_func(struct klp_object *obj, struct klp_func *func)
                                     func->old_sympos ? func->old_sympos : 1);
 }
 
+/* Arches may override this to finish any remaining arch-specific tasks */
+void __weak arch_klp_init_object_loaded(struct klp_patch *patch,
+                                        struct klp_object *obj)
+{
+}
+
 /* parts of the initialization that is done only when the object is loaded */
 static int klp_init_object_loaded(struct klp_patch *patch,
                                   struct klp_object *obj)
@@ -770,9 +774,15 @@ static int klp_init_object_loaded(struct klp_patch *patch,
         struct klp_func *func;
         int ret;
 
+        module_disable_ro(patch->mod);
         ret = klp_write_object_relocations(patch->mod, obj);
-        if (ret)
+        if (ret) {
+                module_enable_ro(patch->mod, true);
                 return ret;
+        }
+
+        arch_klp_init_object_loaded(patch, obj);
+        module_enable_ro(patch->mod, true);
 
         klp_for_each_func(obj, func) {
                 ret = klp_find_object_symbol(obj->name, func->old_name,