diff options
| author | Linus Lüssing <linus.luessing@c0d3.blue> | 2015-06-16 17:10:25 +0200 |
|---|---|---|
| committer | Antonio Quartulli <antonio@meshcoding.com> | 2015-08-14 22:51:40 +0200 |
| commit | 9c936e3f4c4fad07abb6c082a89508b8f724c88f (patch) | |
| tree | 92735d9af12d734e2a9146439d1dae940ad95302 /net/batman-adv/multicast.c | |
| parent | ac4eebd48461ec993e7cb614d5afe7df8c72e6b7 (diff) | |
batman-adv: Make MCAST capability changes atomic
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: 60432d756cf0 ("batman-adv: Announce new capability via multicast TVLV")
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>
Diffstat (limited to 'net/batman-adv/multicast.c')
| -rw-r--r-- | net/batman-adv/multicast.c | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c index 7aa480b7edd0..8f1ec21bf2d0 100644 --- a/net/batman-adv/multicast.c +++ b/net/batman-adv/multicast.c @@ -19,6 +19,7 @@ #include "main.h" #include <linux/atomic.h> +#include <linux/bitops.h> #include <linux/byteorder/generic.h> #include <linux/errno.h> #include <linux/etherdevice.h> @@ -697,29 +698,30 @@ static void batadv_mcast_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, uint8_t mcast_flags = BATADV_NO_FLAGS; bool orig_initialized; - orig_initialized = orig->capa_initialized & BATADV_ORIG_CAPA_HAS_MCAST; + orig_initialized = test_bit(BATADV_ORIG_CAPA_HAS_MCAST, + &orig->capa_initialized); /* If mcast support is turned on decrease the disabled mcast node * counter only if we had increased it for this node before. If this * is a completely new orig_node no need to decrease the counter. */ if (orig_mcast_enabled && - !(orig->capabilities & BATADV_ORIG_CAPA_HAS_MCAST)) { + !test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities)) { if (orig_initialized) atomic_dec(&bat_priv->mcast.num_disabled); - orig->capabilities |= BATADV_ORIG_CAPA_HAS_MCAST; + set_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities); /* If mcast support is being switched off or if this is an initial * OGM without mcast support then increase the disabled mcast * node counter. */ } else if (!orig_mcast_enabled && - (orig->capabilities & BATADV_ORIG_CAPA_HAS_MCAST || + (test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities) || !orig_initialized)) { atomic_inc(&bat_priv->mcast.num_disabled); - orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_MCAST; + clear_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities); } - orig->capa_initialized |= BATADV_ORIG_CAPA_HAS_MCAST; + set_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capa_initialized); if (orig_mcast_enabled && tvlv_value && (tvlv_value_len >= sizeof(mcast_flags))) @@ -763,8 +765,8 @@ void batadv_mcast_purge_orig(struct batadv_orig_node *orig) { struct batadv_priv *bat_priv = orig->bat_priv; - if (!(orig->capabilities & BATADV_ORIG_CAPA_HAS_MCAST) && - orig->capa_initialized & BATADV_ORIG_CAPA_HAS_MCAST) + if (!test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities) && + test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capa_initialized)) atomic_dec(&bat_priv->mcast.num_disabled); batadv_mcast_want_unsnoop_update(bat_priv, orig, BATADV_NO_FLAGS); |