[LEDE-DEV] [PATCH] ubus: Remove unnecessary memset calls.

[Kristian Evensen]

On Tue, Nov 7, 2017 at 9:34 PM, Rosen Penev <rosenp at gmail.com> wrote:
> Replace malloc+memset with calloc. Cleaner and faster in extreme situations.
>
> Signed-off-by: Rosen Penev <rosenp at gmail.com>
> ---
>  libubus.c  |  6 ++----
>  lua/ubus.c | 18 ++++++------------
>  2 files changed, 8 insertions(+), 16 deletions(-)
>
> diff --git a/libubus.c b/libubus.c
> index 9463522..260e40f 100644
> --- a/libubus.c
> +++ b/libubus.c
> @@ -133,7 +133,7 @@ struct ubus_lookup_request {
>  static void ubus_lookup_cb(struct ubus_request *ureq, int type, struct blob_attr *msg)
>  {
>         struct ubus_lookup_request *req;
> -       struct ubus_object_data obj;
> +       struct ubus_object_data obj = {};
>         struct blob_attr **attr;
>
>         req = container_of(ureq, struct ubus_lookup_request, req);
> @@ -143,7 +143,6 @@ static void ubus_lookup_cb(struct ubus_request *ureq, int type, struct blob_attr
>             !attr[UBUS_ATTR_OBJTYPE])
>                 return;
>
> -       memset(&obj, 0, sizeof(obj));
>         obj.id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
>         obj.path = blob_data(attr[UBUS_ATTR_OBJPATH]);
>         obj.type_id = blob_get_u32(attr[UBUS_ATTR_OBJTYPE]);
> @@ -220,7 +219,7 @@ int ubus_register_event_handler(struct ubus_context *ctx,
>                                 const char *pattern)
>  {
>         struct ubus_object *obj = &ev->obj;
> -       struct blob_buf b2;
> +       struct blob_buf b2 = {};
>         int ret;
>
>         if (!obj->id) {
> @@ -236,7 +235,6 @@ int ubus_register_event_handler(struct ubus_context *ctx,
>         }
>
>         /* use a second buffer, ubus_invoke() overwrites the primary one */
> -       memset(&b2, 0, sizeof(b2));
>         blob_buf_init(&b2, 0);
>         blobmsg_add_u32(&b2, "object", obj->id);
>         if (pattern)
> diff --git a/lua/ubus.c b/lua/ubus.c
> index 74a15b0..e9fd10e 100644
> --- a/lua/ubus.c
> +++ b/lua/ubus.c
> @@ -410,11 +410,10 @@ static int ubus_lua_load_methods(lua_State *L, struct ubus_method *m)
>         }
>
>         /* setup the policy pointers */
> -       p = malloc(sizeof(struct blobmsg_policy) * plen);
> +       p = calloc(plen, sizeof(struct blobmsg_policy));
>         if (!p)
>                 return 1;
>
> -       memset(p, 0, sizeof(struct blobmsg_policy) * plen);
>         m->policy = p;
>         lua_pushnil(L);
>         while (lua_next(L, -2) != 0) {
> @@ -481,26 +480,23 @@ static struct ubus_object* ubus_lua_load_object(lua_State *L)
>         int midx = 0;
>
>         /* setup object pointers */
> -       obj = malloc(sizeof(struct ubus_lua_object));
> +       obj = calloc(1, sizeof(struct ubus_lua_object));
>         if (!obj)
>                 return NULL;
>
> -       memset(obj, 0, sizeof(struct ubus_lua_object));
>         obj->o.name = lua_tostring(L, -2);
>
>         /* setup method pointers */
> -       m = malloc(sizeof(struct ubus_method) * mlen);
> -       memset(m, 0, sizeof(struct ubus_method) * mlen);
> +       m = calloc(1, sizeof(struct ubus_method) * mlen);
>         obj->o.methods = m;

While I have no strong opinion on the malloc + memset vs. calloc
debate, here it looks like a check for if (!m) is missing.

-Kristian