From patchwork Tue May 10 19:30:01 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Antonio Quartulli X-Patchwork-Id: 16162 Return-Path: X-Original-To: patchwork@open-mesh.org Delivered-To: patchwork@open-mesh.org Received: from open-mesh.org (localhost [IPv6:::1]) by open-mesh.org (Postfix) with ESMTP id 5331F82B90; Tue, 10 May 2016 21:39:28 +0200 (CEST) Authentication-Results: open-mesh.org; dmarc=none header.from=unstable.cc Received-SPF: Permerror (SPF Permanent Error: Two or more type TXT spf records found.) identity=mailfrom; client-ip=5.148.176.60; helo=s2.neomailbox.net; envelope-from=a@unstable.cc; receiver=b.a.t.m.a.n@lists.open-mesh.org Authentication-Results: open-mesh.org; dmarc=none header.from=unstable.cc Received: from s2.neomailbox.net (s2.neomailbox.net [5.148.176.60]) by open-mesh.org (Postfix) with ESMTPS id EF6B182B87 for ; Tue, 10 May 2016 21:39:10 +0200 (CEST) From: Antonio Quartulli To: davem@davemloft.net Date: Wed, 11 May 2016 03:30:01 +0800 Message-Id: <1462908605-27412-14-git-send-email-a@unstable.cc> In-Reply-To: <1462908605-27412-1-git-send-email-a@unstable.cc> References: <1462908605-27412-1-git-send-email-a@unstable.cc> Cc: netdev@vger.kernel.org, b.a.t.m.a.n@lists.open-mesh.org, Antonio Quartulli , Marek Lindner Subject: [B.A.T.M.A.N.] [PATCH 13/17] batman-adv: Use kref_get for hard_iface subfunctions X-BeenThere: b.a.t.m.a.n@lists.open-mesh.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: The list for a Better Approach To Mobile Ad-hoc Networking List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: The list for a Better Approach To Mobile Ad-hoc Networking Errors-To: b.a.t.m.a.n-bounces@lists.open-mesh.org Sender: "B.A.T.M.A.N" From: Sven Eckelmann The callers of the functions using batadv_hard_iface objects already make sure that they hold a valid reference. The subfunctions don't have to check whether the reference counter is > 0 because this was checked by the callers. The kref_get function instead WARNs (with debug information) when the reference counter would still be 0. This makes a bug in batman-adv better visible because kref_get_unless_zero would have ignored this problem. Signed-off-by: Sven Eckelmann Signed-off-by: Marek Lindner Signed-off-by: Antonio Quartulli --- net/batman-adv/bat_iv_ogm.c | 14 +++----------- net/batman-adv/hard-interface.c | 7 +++---- net/batman-adv/originator.c | 30 +++++++----------------------- 3 files changed, 13 insertions(+), 38 deletions(-) diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index 57e9962c7090..eb3435de54b5 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -681,18 +681,12 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff, unsigned char *skb_buff; unsigned int skb_size; - if (!kref_get_unless_zero(&if_incoming->refcount)) - return; - - if (!kref_get_unless_zero(&if_outgoing->refcount)) - goto out_free_incoming; - /* own packet should always be scheduled */ if (!own_packet) { if (!batadv_atomic_dec_not_zero(&bat_priv->batman_queue_left)) { batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "batman packet queue full\n"); - goto out_free_outgoing; + return; } } @@ -718,6 +712,8 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff, forw_packet_aggr->packet_len = packet_len; memcpy(skb_buff, packet_buff, packet_len); + kref_get(&if_incoming->refcount); + kref_get(&if_outgoing->refcount); forw_packet_aggr->own = own_packet; forw_packet_aggr->if_incoming = if_incoming; forw_packet_aggr->if_outgoing = if_outgoing; @@ -747,10 +743,6 @@ out_free_forw_packet: out_nomem: if (!own_packet) atomic_inc(&bat_priv->batman_queue_left); -out_free_outgoing: - batadv_hardif_put(if_outgoing); -out_free_incoming: - batadv_hardif_put(if_incoming); } /* aggregate a new packet into the existing ogm packet */ diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c index d3d37f3f99cf..7c1d8d7ac548 100644 --- a/net/batman-adv/hard-interface.c +++ b/net/batman-adv/hard-interface.c @@ -236,8 +236,8 @@ static void batadv_primary_if_select(struct batadv_priv *bat_priv, ASSERT_RTNL(); - if (new_hard_iface && !kref_get_unless_zero(&new_hard_iface->refcount)) - new_hard_iface = NULL; + if (new_hard_iface) + kref_get(&new_hard_iface->refcount); curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1); rcu_assign_pointer(bat_priv->primary_if, new_hard_iface); @@ -467,8 +467,7 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface, if (hard_iface->if_status != BATADV_IF_NOT_IN_USE) goto out; - if (!kref_get_unless_zero(&hard_iface->refcount)) - goto out; + kref_get(&hard_iface->refcount); soft_iface = dev_get_by_name(net, iface_name); diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c index 2ed2cc89a669..04fa139911c3 100644 --- a/net/batman-adv/originator.c +++ b/net/batman-adv/originator.c @@ -374,12 +374,8 @@ batadv_orig_ifinfo_new(struct batadv_orig_node *orig_node, if (!orig_ifinfo) goto out; - if (if_outgoing != BATADV_IF_DEFAULT && - !kref_get_unless_zero(&if_outgoing->refcount)) { - kfree(orig_ifinfo); - orig_ifinfo = NULL; - goto out; - } + if (if_outgoing != BATADV_IF_DEFAULT) + kref_get(&if_outgoing->refcount); reset_time = jiffies - 1; reset_time -= msecs_to_jiffies(BATADV_RESET_PROTECTION_MS); @@ -455,11 +451,8 @@ batadv_neigh_ifinfo_new(struct batadv_neigh_node *neigh, if (!neigh_ifinfo) goto out; - if (if_outgoing && !kref_get_unless_zero(&if_outgoing->refcount)) { - kfree(neigh_ifinfo); - neigh_ifinfo = NULL; - goto out; - } + if (if_outgoing) + kref_get(&if_outgoing->refcount); INIT_HLIST_NODE(&neigh_ifinfo->list); kref_init(&neigh_ifinfo->refcount); @@ -532,15 +525,11 @@ batadv_hardif_neigh_create(struct batadv_hard_iface *hard_iface, if (hardif_neigh) goto out; - if (!kref_get_unless_zero(&hard_iface->refcount)) - goto out; - hardif_neigh = kzalloc(sizeof(*hardif_neigh), GFP_ATOMIC); - if (!hardif_neigh) { - batadv_hardif_put(hard_iface); + if (!hardif_neigh) goto out; - } + kref_get(&hard_iface->refcount); INIT_HLIST_NODE(&hardif_neigh->list); ether_addr_copy(hardif_neigh->addr, neigh_addr); hardif_neigh->if_incoming = hard_iface; @@ -643,16 +632,11 @@ batadv_neigh_node_new(struct batadv_orig_node *orig_node, if (!neigh_node) goto out; - if (!kref_get_unless_zero(&hard_iface->refcount)) { - kfree(neigh_node); - neigh_node = NULL; - goto out; - } - INIT_HLIST_NODE(&neigh_node->list); INIT_HLIST_HEAD(&neigh_node->ifinfo_list); spin_lock_init(&neigh_node->ifinfo_lock); + kref_get(&hard_iface->refcount); ether_addr_copy(neigh_node->addr, neigh_addr); neigh_node->if_incoming = hard_iface; neigh_node->orig_node = orig_node;