From: Linus Lüssing linus.luessing@c0d3.blue
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 linus.luessing@c0d3.blue Signed-off-by: Marek Lindner mareklindner@neomailbox.ch Signed-off-by: Antonio Quartulli antonio@meshcoding.com --- 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 b482495..1573489 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -19,6 +19,7 @@ #include "main.h"
#include <linux/atomic.h> +#include <linux/bitops.h> #include <linux/bug.h> #include <linux/byteorder/generic.h> #include <linux/compiler.h> @@ -1862,7 +1863,7 @@ 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, @@ -3321,7 +3322,8 @@ 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 ed4aec5..6f801ef 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -274,7 +274,7 @@ 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; @@ -315,7 +315,7 @@ 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), };