From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: =?UTF-8?q?Linus=20L=C3=BCssing?= Date: Tue, 16 Jun 2015 15:17:22 +0200 Message-Id: <1434460643-3681-5-git-send-email-linus.luessing@c0d3.blue> In-Reply-To: <1434460643-3681-1-git-send-email-linus.luessing@c0d3.blue> References: <1434460643-3681-1-git-send-email-linus.luessing@c0d3.blue> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Subject: [B.A.T.M.A.N.] [PATCHv3 maint 4/5] batman-adv: Make MCAST capability changes atomic Reply-To: The list for a Better Approach To Mobile Ad-hoc Networking List-Id: The list for a Better Approach To Mobile Ad-hoc Networking List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: b.a.t.m.a.n@lists.open-mesh.org Bitwise OR/AND assignments in C aren't guaranteed to be atomic. One OGM handler might undo the set/clear of a specific bit from another handler run in between. Fix this by using the atomic set_bit()/clear_bit() functions. Fixes: 77ec494490d6 ("batman-adv: Announce new capability via multicast TVLV") Signed-off-by: Linus Lüssing --- multicast.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/multicast.c b/multicast.c index 09f2838..00612bf 100644 --- a/multicast.c +++ b/multicast.c @@ -684,7 +684,7 @@ static void batadv_mcast_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, !(orig->capabilities & BATADV_ORIG_CAPA_HAS_MCAST)) { if (orig_initialized) atomic_dec(&bat_priv->mcast.num_disabled); - orig->capabilities |= BATADV_ORIG_CAPA_HAS_MCAST; + set_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities); /* If mcast support is being switched off or if this is an initial * OGM without mcast support then increase the disabled mcast * node counter. @@ -693,10 +693,10 @@ static void batadv_mcast_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, (orig->capabilities & BATADV_ORIG_CAPA_HAS_MCAST || !orig_initialized)) { atomic_inc(&bat_priv->mcast.num_disabled); - orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_MCAST; + clear_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities); } - orig->capa_initialized |= BATADV_ORIG_CAPA_HAS_MCAST; + set_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capa_initialized); if (orig_mcast_enabled && tvlv_value && (tvlv_value_len >= sizeof(mcast_flags))) -- 1.7.10.4