This is a note to let you know that I've just added the patch titled
batman-adv: Make DAT capability changes atomic
to the 4.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
batman-adv-make-dat-capability-changes-atomic.patch
and it can be found in the queue-4.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 65d7d46050704bcdb8121ddbf4110bfbf2b38baa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Linus=20L=C3=BCssing?= <linus.luessing@xxxxxxxxx>
Date: Tue, 16 Jun 2015 17:10:22 +0200
Subject: batman-adv: Make DAT capability changes atomic
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From: =?UTF-8?q?Linus=20L=C3=BCssing?= <linus.luessing@xxxxxxxxx>
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@xxxxxxxxx>
Signed-off-by: Marek Lindner <mareklindner@xxxxxxxxxxxxx>
Signed-off-by: Antonio Quartulli <antonio@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/batman-adv/distributed-arp-table.c | 7 ++++---
net/batman-adv/types.h | 4 ++--
2 files changed, 6 insertions(+), 5 deletions(-)
--- 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
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_
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);
}
/**
--- 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),
Patches currently in stable-queue which might be from linus.luessing@xxxxxxxxx are
queue-4.2/batman-adv-make-dat-capability-changes-atomic.patch
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