[B.A.T.M.A.N.] [PATCHv3 maint 3/5] batman-adv: Make TT capability changes atomic

[Linus Lüssing]

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: 5d2121af6d31 ("batman-adv: introduce capability initialization bitfield")
Signed-off-by: Linus Lüssing <linus.luess...@c0d3.blue>
---
 translation-table.c |    4 ++--
 types.h             |    2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/translation-table.c b/translation-table.c
index b098e53..e95a424 100644
--- a/translation-table.c
+++ b/translation-table.c
@@ -1843,7 +1843,7 @@ 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,
@@ -2802,7 +2802,7 @@ 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,
diff --git a/types.h b/types.h
index e33b5aa..c6ec558 100644
--- a/types.h
+++ b/types.h
@@ -257,7 +257,7 @@ 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;
-- 
1.7.10.4