From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from youngberry.canonical.com ([91.189.89.112]:43197 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753413AbbJTVgk (ORCPT ); Tue, 20 Oct 2015 17:36:40 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: =?UTF-8?q?Linus=20L=C3=BCssing?= , Marek Lindner , Antonio Quartulli , Luis Henriques , Kamal Mostafa Subject: [PATCH 3.13.y-ckt 74/85] batman-adv: Make DAT capability changes atomic Date: Tue, 20 Oct 2015 14:35:30 -0700 Message-Id: <1445376941-7046-75-git-send-email-kamal@canonical.com> In-Reply-To: <1445376941-7046-1-git-send-email-kamal@canonical.com> References: <1445376941-7046-1-git-send-email-kamal@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 3.13.11-ckt28 -stable review patch. If anyone has any objections, please let me know. ------------------ From: =?UTF-8?q?Linus=20L=C3=BCssing?= commit 65d7d46050704bcdb8121ddbf4110bfbf2b38baa upstream. 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()/test_bit() functions. Fixes: 17cf0ea455f1 ("batman-adv: tvlv - add distributed arp table container") Signed-off-by: Linus Lüssing Signed-off-by: Marek Lindner Signed-off-by: Antonio Quartulli [ luis: backported to 3.16: adjusted context ] Signed-off-by: Luis Henriques Signed-off-by: Kamal Mostafa --- net/batman-adv/distributed-arp-table.c | 7 ++++--- net/batman-adv/types.h | 4 ++-- 2 files changed, 6 insertions(+), 5 deletions(-) diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index e086dab..a80dece 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -17,6 +17,7 @@ * 02110-1301, USA */ +#include #include #include #include @@ -424,7 +425,7 @@ static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res, int j; /* check if orig node candidate is running DAT */ - if (!(candidate->capabilities & BATADV_ORIG_CAPA_HAS_DAT)) + if (!test_bit(BATADV_ORIG_CAPA_HAS_DAT, &candidate->capabilities)) goto out; /* Check if this node has already been selected... */ @@ -681,9 +682,9 @@ static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, uint16_t tvlv_value_len) { if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) - orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_DAT; + clear_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities); else - orig->capabilities |= BATADV_ORIG_CAPA_HAS_DAT; + set_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities); } /** diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 91dd369..a235b3b 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -217,7 +217,7 @@ struct batadv_orig_node { unsigned long last_seen; unsigned long bcast_seqno_reset; unsigned long batman_seqno_reset; - uint8_t capabilities; + unsigned long capabilities; atomic_t last_ttvn; unsigned char *tt_buff; int16_t tt_buff_len; @@ -258,7 +258,7 @@ struct batadv_orig_node { * @BATADV_ORIG_CAPA_HAS_NC: orig node has network coding enabled */ enum batadv_orig_capabilities { - BATADV_ORIG_CAPA_HAS_DAT = BIT(0), + BATADV_ORIG_CAPA_HAS_DAT, BATADV_ORIG_CAPA_HAS_NC = BIT(1), }; -- 1.9.1