diff mbox

[v4,maint,3/5] batman-adv: Make TT capability changes atomic

Message ID 1434467426-4281-4-git-send-email-linus.luessing@c0d3.blue
State Accepted, archived
Headers show

Commit Message

Linus Lüssing June 16, 2015, 3:10 p.m. UTC
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.luessing@c0d3.blue>
---
 translation-table.c |    4 ++--
 types.h             |    2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

Comments

Marek Lindner June 17, 2015, 10:38 a.m. UTC | #1
On Tuesday, June 16, 2015 17:10:24 Linus Lüssing wrote:
> 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.luessing@c0d3.blue>
> ---
>  translation-table.c |    4 ++--
>  types.h             |    2 +-
>  2 files changed, 3 insertions(+), 3 deletions(-)

Applied in revision a51fa16.

Thanks,
Marek
diff mbox

Patch

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;