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>
This commit is contained in:
Rasmus Villemoes 2019-03-07 16:27:37 -08:00 committed by Linus Torvalds
parent 2bdde670be
commit cdf6d00696

View File

@ -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);
}