batman-adv: Make TT 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: e17931d1a61d ("batman-adv: introduce capability initialization bitfield")
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>
diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index b482495..1573489 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -19,6 +19,7 @@
#include "main.h"
#include <linux/atomic.h>
+#include <linux/bitops.h>
#include <linux/bug.h>
#include <linux/byteorder/generic.h>
#include <linux/compiler.h>
@@ -1862,7 +1863,7 @@
}
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,
@@ -2821,7 +2822,7 @@
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,
@@ -3321,7 +3322,8 @@
bool has_tt_init;
tt_vlan = (struct batadv_tvlv_tt_vlan_data *)tt_buff;
- has_tt_init = orig_node->capa_initialized & BATADV_ORIG_CAPA_HAS_TT;
+ has_tt_init = test_bit(BATADV_ORIG_CAPA_HAS_TT,
+ &orig_node->capa_initialized);
/* orig table not initialised AND first diff is in the OGM OR the ttvn
* increased by one -> we can apply the attached changes