path: root/lib
diff options
authorRasmus Villemoes <linux@rasmusvillemoes.dk>2019-03-07 16:27:37 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-03-07 18:32:00 -0800
commitcdf6d00696865ae1c46750059fd7d248323712f9 (patch)
tree08903df02a81ec1a5f20442842b7a68d1c3d7cb6 /lib
parent2bdde670beedf73de38b8607f0b1913358af7381 (diff)
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 <linux@rasmusvillemoes.dk> Acked-by: Jason Baron <jbaron@akamai.com> Cc: David Sterba <dsterba@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Petr Mladek <pmladek@suse.com> Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
1 files 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)
- kfree_const(dt->mod_name);