From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Luis Henriques 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 Subject: [PATCH 3.16.y-ckt 097/133] batman-adv: Make TT capability changes atomic Date: Wed, 30 Sep 2015 10:50:45 +0100 Message-Id: <1443606681-7124-98-git-send-email-luis.henriques@canonical.com> In-Reply-To: <1443606681-7124-1-git-send-email-luis.henriques@canonical.com> References: <1443606681-7124-1-git-send-email-luis.henriques@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.16.7-ckt18 -stable review patch. If anyone has any objections, please let me know. ------------------ From: =?UTF-8?q?Linus=20L=C3=BCssing?= commit ac4eebd48461ec993e7cb614d5afe7df8c72e6b7 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: e17931d1a61d ("batman-adv: introduce capability initialization bitfield") 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 --- net/batman-adv/translation-table.c | 8 +++++--- net/batman-adv/types.h | 4 ++-- 2 files changed, 7 insertions(+), 5 deletions(-) diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index 4503069e29b5..b3e61e575f06 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -26,6 +26,7 @@ #include "bridge_loop_avoidance.h" #include "multicast.h" +#include #include /* hash class keys */ @@ -1861,7 +1862,7 @@ void batadv_tt_global_del_orig(struct batadv_priv *bat_priv, } spin_unlock_bh(list_lock); } - orig_node->capa_initialized &= ~BATADV_ORIG_CAPA_HAS_TT; + clear_bit(BATADV_ORIG_CAPA_HAS_TT, &orig_node->capa_initialized); } static bool batadv_tt_global_to_purge(struct batadv_tt_global_entry *tt_global, @@ -2821,7 +2822,7 @@ static void _batadv_tt_update_changes(struct batadv_priv *bat_priv, return; } } - orig_node->capa_initialized |= BATADV_ORIG_CAPA_HAS_TT; + set_bit(BATADV_ORIG_CAPA_HAS_TT, &orig_node->capa_initialized); } static void batadv_tt_fill_gtable(struct batadv_priv *bat_priv, @@ -3323,7 +3324,8 @@ static void batadv_tt_update_orig(struct batadv_priv *bat_priv, bool has_tt_init; tt_vlan = (struct batadv_tvlv_tt_vlan_data *)tt_buff; - has_tt_init = orig_node->capa_initialized & BATADV_ORIG_CAPA_HAS_TT; + has_tt_init = test_bit(BATADV_ORIG_CAPA_HAS_TT, + &orig_node->capa_initialized); /* orig table not initialised AND first diff is in the OGM OR the ttvn * increased by one -> we can apply the attached changes diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 1b0b053ae729..fdf65b50e3ec 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -259,7 +259,7 @@ struct batadv_orig_node { struct hlist_node mcast_want_all_ipv6_node; #endif unsigned long capabilities; - uint8_t capa_initialized; + unsigned long capa_initialized; atomic_t last_ttvn; unsigned char *tt_buff; int16_t tt_buff_len; @@ -300,7 +300,7 @@ struct batadv_orig_node { enum batadv_orig_capabilities { BATADV_ORIG_CAPA_HAS_DAT, BATADV_ORIG_CAPA_HAS_NC, - BATADV_ORIG_CAPA_HAS_TT = BIT(2), + BATADV_ORIG_CAPA_HAS_TT, BATADV_ORIG_CAPA_HAS_MCAST = BIT(3), };