devlink: have genetlink code to parse the attrs during dumpit

Benefit from the fact that the generic netlink code can parse the attrs
for dumpit op and avoid need to parse it in the op callback.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/devlink.c

@@ -3943,29 +3943,19 @@ static int devlink_nl_region_read_snapshot_fill(struct sk_buff *skb,
 static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb,
 					     struct netlink_callback *cb)
 {
+	const struct genl_dumpit_info *info = genl_dumpit_info(cb);
 	u64 ret_offset, start_offset, end_offset = 0;
+	struct nlattr **attrs = info->attrs;
 	struct devlink_region *region;
 	struct nlattr *chunks_attr;
 	const char *region_name;
 	struct devlink *devlink;
-	struct nlattr **attrs;
 	bool dump = true;
 	void *hdr;
 	int err;
 
 	start_offset = *((u64 *)&cb->args[0]);
 
-	attrs = kmalloc_array(DEVLINK_ATTR_MAX + 1, sizeof(*attrs), GFP_KERNEL);
-	if (!attrs)
-		return -ENOMEM;
-
-	err = nlmsg_parse_deprecated(cb->nlh,
-				     GENL_HDRLEN + devlink_nl_family.hdrsize,
-				     attrs, DEVLINK_ATTR_MAX,
-				     devlink_nl_family.policy, cb->extack);
-	if (err)
-		goto out_free;
-
 	mutex_lock(&devlink_mutex);
 	devlink = devlink_get_from_attrs(sock_net(cb->skb->sk), attrs);
 	if (IS_ERR(devlink)) {
@@ -4042,7 +4032,6 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb,
 	genlmsg_end(skb, hdr);
 	mutex_unlock(&devlink->lock);
 	mutex_unlock(&devlink_mutex);
-	kfree(attrs);
 
 	return skb->len;
 
@@ -4052,8 +4041,6 @@ out_unlock:
 	mutex_unlock(&devlink->lock);
 out_dev:
 	mutex_unlock(&devlink_mutex);
-out_free:
-	kfree(attrs);
 	return err;
 }
 
@@ -4995,21 +4982,10 @@ devlink_health_reporter_get_from_info(struct devlink *devlink,
 static struct devlink_health_reporter *
 devlink_health_reporter_get_from_cb(struct netlink_callback *cb)
 {
+	const struct genl_dumpit_info *info = genl_dumpit_info(cb);
 	struct devlink_health_reporter *reporter;
+	struct nlattr **attrs = info->attrs;
 	struct devlink *devlink;
-	struct nlattr **attrs;
-	int err;
-
-	attrs = kmalloc_array(DEVLINK_ATTR_MAX + 1, sizeof(*attrs), GFP_KERNEL);
-	if (!attrs)
-		return NULL;
-
-	err = nlmsg_parse_deprecated(cb->nlh,
-				     GENL_HDRLEN + devlink_nl_family.hdrsize,
-				     attrs, DEVLINK_ATTR_MAX,
-				     devlink_nl_family.policy, cb->extack);
-	if (err)
-		goto free;
 
 	mutex_lock(&devlink_mutex);
 	devlink = devlink_get_from_attrs(sock_net(cb->skb->sk), attrs);
@@ -5018,12 +4994,9 @@ devlink_health_reporter_get_from_cb(struct netlink_callback *cb)
 
 	reporter = devlink_health_reporter_get_from_attrs(devlink, attrs);
 	mutex_unlock(&devlink_mutex);
-	kfree(attrs);
 	return reporter;
 unlock:
 	mutex_unlock(&devlink_mutex);
-free:
-	kfree(attrs);
 	return NULL;
 }
 
@@ -6154,7 +6127,8 @@ static const struct genl_ops devlink_nl_ops[] = {
 	},
 	{
 		.cmd = DEVLINK_CMD_REGION_READ,
-		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.validate = GENL_DONT_VALIDATE_STRICT |
+			    GENL_DONT_VALIDATE_DUMP_STRICT,
 		.dumpit = devlink_nl_cmd_region_read_dumpit,
 		.flags = GENL_ADMIN_PERM,
 		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK,