lkml.org 
[lkml]   [2015]   [Oct]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3.13.y-ckt 74/85] batman-adv: Make DAT capability changes atomic
Date
3.13.11-ckt28 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: =?UTF-8?q?Linus=20L=C3=BCssing?= <linus.luessing@c0d3.blue>

commit 65d7d46050704bcdb8121ddbf4110bfbf2b38baa upstream.

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>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
net/batman-adv/distributed-arp-table.c | 7 ++++---
net/batman-adv/types.h | 4 ++--
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 e086dab..a80dece 100644
--- a/net/batman-adv/distributed-arp-table.c
+++ b/net/batman-adv/distributed-arp-table.c
@@ -17,6 +17,7 @@
* 02110-1301, USA
*/

+#include <linux/bitops.h>
#include <linux/if_ether.h>
#include <linux/if_arp.h>
#include <linux/if_vlan.h>
@@ -424,7 +425,7 @@ 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... */
@@ -681,9 +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);
}

/**
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index 91dd369..a235b3b 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -217,7 +217,7 @@ struct batadv_orig_node {
unsigned long last_seen;
unsigned long bcast_seqno_reset;
unsigned long batman_seqno_reset;
- uint8_t capabilities;
+ unsigned long capabilities;
atomic_t last_ttvn;
unsigned char *tt_buff;
int16_t tt_buff_len;
@@ -258,7 +258,7 @@ struct batadv_orig_node {
* @BATADV_ORIG_CAPA_HAS_NC: orig node has network coding enabled
*/
enum batadv_orig_capabilities {
- BATADV_ORIG_CAPA_HAS_DAT = BIT(0),
+ BATADV_ORIG_CAPA_HAS_DAT,
BATADV_ORIG_CAPA_HAS_NC = BIT(1),
};

--
1.9.1


\
 
 \ /
  Last update: 2015-10-21 00:41    [W:0.186 / U:0.492 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site