From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from youngberry.canonical.com ([91.189.89.112]:43203 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753417AbbJTVgk (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 75/85] batman-adv: Make NC capability changes atomic Date: Tue, 20 Oct 2015 14:35:31 -0700 Message-Id: <1445376941-7046-76-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 4635469f5c617282f18c69643af36cd8c0acf707 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: 3f4841ffb336 ("batman-adv: tvlv - add network coding 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/network-coding.c | 7 ++++--- net/batman-adv/types.h | 2 +- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/net/batman-adv/network-coding.c b/net/batman-adv/network-coding.c index 511d7e1..71decc0 100644 --- a/net/batman-adv/network-coding.c +++ b/net/batman-adv/network-coding.c @@ -17,6 +17,7 @@ * 02110-1301, USA */ +#include #include #include "main.h" @@ -106,9 +107,9 @@ static void batadv_nc_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_NC; + clear_bit(BATADV_ORIG_CAPA_HAS_NC, &orig->capabilities); else - orig->capabilities |= BATADV_ORIG_CAPA_HAS_NC; + set_bit(BATADV_ORIG_CAPA_HAS_NC, &orig->capabilities); } /** @@ -860,7 +861,7 @@ void batadv_nc_update_nc_node(struct batadv_priv *bat_priv, goto out; /* check if orig node is network coding enabled */ - if (!(orig_node->capabilities & BATADV_ORIG_CAPA_HAS_NC)) + if (!test_bit(BATADV_ORIG_CAPA_HAS_NC, &orig_node->capabilities)) goto out; /* accept ogms from 'good' neighbors and single hop neighbors */ diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index a235b3b..471bff8 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -259,7 +259,7 @@ struct batadv_orig_node { */ enum batadv_orig_capabilities { BATADV_ORIG_CAPA_HAS_DAT, - BATADV_ORIG_CAPA_HAS_NC = BIT(1), + BATADV_ORIG_CAPA_HAS_NC, }; /** -- 1.9.1