[maint,1/2] batman-adv: Make originator 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. This can lead to various issues in other
code paths, including kernel panics.
Fix this by using the atomic set_bit()/clear_bit() functions.
Fixes: 2b1c07b918d2 ("batman-adv: tvlv - add distributed arp table container")
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
---
distributed-arp-table.c | 4 ++--
multicast.c | 6 +++---
network-coding.c | 4 ++--
translation-table.c | 4 ++--
types.h | 4 ++--
5 files changed, 11 insertions(+), 11 deletions(-)
Comments
On Monday, June 15, 2015 08:22:24 Linus Lüssing wrote:
> Fix this by using the atomic set_bit()/clear_bit() functions.
>
> Fixes: 2b1c07b918d2 ("batman-adv: tvlv - add distributed arp table
> container") Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
If I am not mistaken the referenced patch only touches the DAT capabilities.
You should send separate patches for each regression.
Cheers,
Marek
@@ -682,9 +682,9 @@ static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
uint16_t tvlv_value_len)
{
if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
- orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_DAT;
+ clear_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities);
else
- orig->capabilities |= BATADV_ORIG_CAPA_HAS_DAT;
+ set_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities);
}
/**
@@ -684,7 +684,7 @@ static void batadv_mcast_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
!(orig->capabilities & BATADV_ORIG_CAPA_HAS_MCAST)) {
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.
@@ -693,10 +693,10 @@ static void batadv_mcast_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
(orig->capabilities & BATADV_ORIG_CAPA_HAS_MCAST ||
!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)))
@@ -105,9 +105,9 @@ static void batadv_nc_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
uint16_t tvlv_value_len)
{
if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
- orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_NC;
+ clear_bit(BATADV_ORIG_CAPA_HAS_NC, &orig->capabilities);
else
- orig->capabilities |= BATADV_ORIG_CAPA_HAS_NC;
+ set_bit(BATADV_ORIG_CAPA_HAS_NC, &orig->capabilities);
}
/**
@@ -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,
@@ -256,8 +256,8 @@ struct batadv_orig_node {
struct hlist_node mcast_want_all_ipv4_node;
struct hlist_node mcast_want_all_ipv6_node;
#endif
- uint8_t capabilities;
- uint8_t capa_initialized;
+ unsigned long capabilities;
+ unsigned long capa_initialized;
atomic_t last_ttvn;
unsigned char *tt_buff;
int16_t tt_buff_len;