Merge tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel...

[linux-block.git] / lib / dynamic_debug.c

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 009f2ead09c1e0009479f999b36953dee4a02249..fdd6d9800a7007141563de5feb5ebe26b9eedb68 100644 (file)
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -1223,8 +1223,7 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt,
  * Allocate a new ddebug_table for the given module
  * and add it to the global list.
  */
-static int __ddebug_add_module(struct _ddebug_info *di, unsigned int base,
-                              const char *modname)
+static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
 {
        struct ddebug_table *dt;
 
@@ -1263,11 +1262,6 @@ static int __ddebug_add_module(struct _ddebug_info *di, unsigned int base,
        return 0;
 }
 
-int ddebug_add_module(struct _ddebug_info *di, const char *modname)
-{
-       return __ddebug_add_module(di, 0, modname);
-}
-
 /* helper for ddebug_dyndbg_(boot|module)_param_cb */
 static int ddebug_dyndbg_param_cb(char *param, char *val,
                                const char *modname, int on_err)
@@ -1314,11 +1308,13 @@ static void ddebug_table_free(struct ddebug_table *dt)
        kfree(dt);
 }
 
+#ifdef CONFIG_MODULES
+
 /*
  * Called in response to a module being unloaded.  Removes
  * any ddebug_table's which point at the module.
  */
-int ddebug_remove_module(const char *mod_name)
+static int ddebug_remove_module(const char *mod_name)
 {
        struct ddebug_table *dt, *nextdt;
        int ret = -ENOENT;
@@ -1337,6 +1333,33 @@ int ddebug_remove_module(const char *mod_name)
        return ret;
 }
 
+static int ddebug_module_notify(struct notifier_block *self, unsigned long val,
+                               void *data)
+{
+       struct module *mod = data;
+       int ret = 0;
+
+       switch (val) {
+       case MODULE_STATE_COMING:
+               ret = ddebug_add_module(&mod->dyndbg_info, mod->name);
+               if (ret)
+                       WARN(1, "Failed to allocate memory: dyndbg may not work properly.\n");
+               break;
+       case MODULE_STATE_GOING:
+               ddebug_remove_module(mod->name);
+               break;
+       }
+
+       return notifier_from_errno(ret);
+}
+
+static struct notifier_block ddebug_module_nb = {
+       .notifier_call = ddebug_module_notify,
+       .priority = 0, /* dynamic debug depends on jump label */
+};
+
+#endif /* CONFIG_MODULES */
+
 static void ddebug_remove_all_tables(void)
 {
        mutex_lock(&ddebug_lock);
@@ -1388,6 +1411,14 @@ static int __init dynamic_debug_init(void)
                .num_classes = __stop___dyndbg_classes - __start___dyndbg_classes,
        };
 
+#ifdef CONFIG_MODULES
+       ret = register_module_notifier(&ddebug_module_nb);
+       if (ret) {
+               pr_warn("Failed to register dynamic debug module notifier\n");
+               return ret;
+       }
+#endif /* CONFIG_MODULES */
+
        if (&__start___dyndbg == &__stop___dyndbg) {
                if (IS_ENABLED(CONFIG_DYNAMIC_DEBUG)) {
                        pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
@@ -1408,7 +1439,7 @@ static int __init dynamic_debug_init(void)
                        mod_ct++;
                        di.num_descs = mod_sites;
                        di.descs = iter_mod_start;
-                       ret = __ddebug_add_module(&di, i - mod_sites, modname);
+                       ret = ddebug_add_module(&di, modname);
                        if (ret)
                                goto out_err;
 
@@ -1419,7 +1450,7 @@ static int __init dynamic_debug_init(void)
        }
        di.num_descs = mod_sites;
        di.descs = iter_mod_start;
-       ret = __ddebug_add_module(&di, i - mod_sites, modname);
+       ret = ddebug_add_module(&di, modname);
        if (ret)
                goto out_err;