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