From cdf6d00696865ae1c46750059fd7d248323712f9 Mon Sep 17 00:00:00 2001 From: Rasmus Villemoes Date: Thu, 7 Mar 2019 16:27:37 -0800 Subject: [PATCH] dynamic_debug: don't duplicate modname in ddebug_add_module For built-in modules, we're already reusing the passed-in string via kstrdup_const(). But for actual modules (i.e. when we're called from dynamic_debug_setup in module.c), the passed-in string (which points at the name[] array inside struct module) is also guaranteed to live at least as long as the struct ddebug_table, since free_module() calls ddebug_remove_module(). Link: http://lkml.kernel.org/r/20190212214150.4807-6-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes Acked-by: Jason Baron Cc: David Sterba Cc: Greg Kroah-Hartman Cc: Ingo Molnar Cc: Petr Mladek Cc: "Rafael J . Wysocki" Cc: Steven Rostedt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/dynamic_debug.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index dbf2b457e47e..8274c4ea75e0 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -847,17 +847,17 @@ int ddebug_add_module(struct _ddebug *tab, unsigned int n, const char *name) { struct ddebug_table *dt; - const char *new_name; dt = kzalloc(sizeof(*dt), GFP_KERNEL); if (dt == NULL) return -ENOMEM; - new_name = kstrdup_const(name, GFP_KERNEL); - if (new_name == NULL) { - kfree(dt); - return -ENOMEM; - } - dt->mod_name = new_name; + /* + * For built-in modules, name lives in .rodata and is + * immortal. For loaded modules, name points at the name[] + * member of struct module, which lives at least as long as + * this struct ddebug_table. + */ + dt->mod_name = name; dt->num_ddebugs = n; dt->ddebugs = tab; @@ -913,7 +913,6 @@ int ddebug_dyndbg_module_param_cb(char *param, char *val, const char *module) static void ddebug_table_free(struct ddebug_table *dt) { list_del_init(&dt->link); - kfree_const(dt->mod_name); kfree(dt); } -- 2.30.2