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authorLinus Lüssing <linus.luessing@c0d3.blue>2015-06-16 17:10:22 +0200
committerAntonio Quartulli <antonio@meshcoding.com>2015-08-14 22:50:42 +0200
commit65d7d46050704bcdb8121ddbf4110bfbf2b38baa (patch)
treee23f7284cf9b76d6b6cb8ea91b51ccd6b08bbfce
parent571a963768e7711e0bb5a30f71247b46ec9ca7b9 (diff)
downloadlinux-65d7d46050704bcdb8121ddbf4110bfbf2b38baa.tar.bz2
batman-adv: Make DAT 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: 17cf0ea455f1 ("batman-adv: tvlv - add distributed arp table container") 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>
-rw-r--r--net/batman-adv/distributed-arp-table.c7
-rw-r--r--net/batman-adv/types.h4
2 files changed, 6 insertions, 5 deletions
diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c
index fb54e6aed096..1cfba20d5112 100644
--- a/net/batman-adv/distributed-arp-table.c
+++ b/net/batman-adv/distributed-arp-table.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>
@@ -453,7 +454,7 @@ static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res,
int j;
/* check if orig node candidate is running DAT */
- if (!(candidate->capabilities & BATADV_ORIG_CAPA_HAS_DAT))
+ if (!test_bit(BATADV_ORIG_CAPA_HAS_DAT, &candidate->capabilities))
goto out;
/* Check if this node has already been selected... */
@@ -713,9 +714,9 @@ 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);
}
/**
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index 67d63483618e..29fd62562546 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -273,7 +273,7 @@ struct batadv_orig_node {
struct hlist_node mcast_want_all_ipv4_node;
struct hlist_node mcast_want_all_ipv6_node;
#endif
- uint8_t capabilities;
+ unsigned long capabilities;
uint8_t capa_initialized;
atomic_t last_ttvn;
unsigned char *tt_buff;
@@ -313,7 +313,7 @@ struct batadv_orig_node {
* (= orig node announces a tvlv of type BATADV_TVLV_MCAST)
*/
enum batadv_orig_capabilities {
- BATADV_ORIG_CAPA_HAS_DAT = BIT(0),
+ BATADV_ORIG_CAPA_HAS_DAT,
BATADV_ORIG_CAPA_HAS_NC = BIT(1),
BATADV_ORIG_CAPA_HAS_TT = BIT(2),
BATADV_ORIG_CAPA_HAS_MCAST = BIT(3),