[PATCH] lib/dynamic_debug.c: use kstrdup_const

[PATCH] lib/dynamic_debug.c: use kstrdup_const

[Rasmus Villemoes]

Using kstrdup_const, thus reusing .rodata when possible, saves around
2 kB of runtime memory on my laptop/.config combination.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 lib/dynamic_debug.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index e491e02eff54..e3952e9c8ec0 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -42,7 +42,7 @@ extern struct _ddebug __stop___verbose[];
 
 struct ddebug_table {
 	struct list_head link;
-	char *mod_name;
+	const char *mod_name;
 	unsigned int num_ddebugs;
 	struct _ddebug *ddebugs;
 };
@@ -841,12 +841,12 @@ int ddebug_add_module(struct _ddebug *tab, unsigned int n,
 			     const char *name)
 {
 	struct ddebug_table *dt;
-	char *new_name;
+	const char *new_name;
 
 	dt = kzalloc(sizeof(*dt), GFP_KERNEL);
 	if (dt == NULL)
 		return -ENOMEM;
-	new_name = kstrdup(name, GFP_KERNEL);
+	new_name = kstrdup_const(name, GFP_KERNEL);
 	if (new_name == NULL) {
 		kfree(dt);
 		return -ENOMEM;
@@ -907,7 +907,7 @@ 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(dt->mod_name);
+	kfree_const(dt->mod_name);
 	kfree(dt);
 }
 
-- 
2.1.3

Re: [PATCH] lib/dynamic_debug.c: use kstrdup_const

[Jason Baron]

Looks fine to me.

Acked-by: Jason Baron <jbaron@akamai.com>

Andrew, want to pick this up?

Thanks,

-Jason

On 09/09/2015 05:40 PM, Rasmus Villemoes wrote:
> Using kstrdup_const, thus reusing .rodata when possible, saves around
> 2 kB of runtime memory on my laptop/.config combination.
> 
> Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
> ---
>  lib/dynamic_debug.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
> index e491e02eff54..e3952e9c8ec0 100644
> --- a/lib/dynamic_debug.c
> +++ b/lib/dynamic_debug.c
> @@ -42,7 +42,7 @@ extern struct _ddebug __stop___verbose[];
>  
>  struct ddebug_table {
>  	struct list_head link;
> -	char *mod_name;
> +	const char *mod_name;
>  	unsigned int num_ddebugs;
>  	struct _ddebug *ddebugs;
>  };
> @@ -841,12 +841,12 @@ int ddebug_add_module(struct _ddebug *tab, unsigned int n,
>  			     const char *name)
>  {
>  	struct ddebug_table *dt;
> -	char *new_name;
> +	const char *new_name;
>  
>  	dt = kzalloc(sizeof(*dt), GFP_KERNEL);
>  	if (dt == NULL)
>  		return -ENOMEM;
> -	new_name = kstrdup(name, GFP_KERNEL);
> +	new_name = kstrdup_const(name, GFP_KERNEL);
>  	if (new_name == NULL) {
>  		kfree(dt);
>  		return -ENOMEM;
> @@ -907,7 +907,7 @@ 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(dt->mod_name);
> +	kfree_const(dt->mod_name);
>  	kfree(dt);
>  }
>  
>