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From: "Linus Lüssing" <linus.luessing@c0d3.blue>
To: b.a.t.m.a.n@lists.open-mesh.org
Subject: [B.A.T.M.A.N.] [PATCHv2 maint 2/5] batman-adv: Make NC capability changes atomic
Date: Tue, 16 Jun 2015 14:44:32 +0200	[thread overview]
Message-ID: <1434458675-3343-3-git-send-email-linus.luessing@c0d3.blue> (raw)
In-Reply-To: <1434458675-3343-1-git-send-email-linus.luessing@c0d3.blue>

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() functions.

Fixes: 7dd9d8992b0c ("batman-adv: tvlv - add network coding container")
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
---
 network-coding.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/network-coding.c b/network-coding.c
index 89e1d47..3ce493e 100644
--- a/network-coding.c
+++ b/network-coding.c
@@ -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);
 }
 
 /**
-- 
1.7.10.4


  parent reply	other threads:[~2015-06-16 12:44 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-16 12:44 [B.A.T.M.A.N.] [PATCHv2 maint 0/5] Fixes for parallel OGM processing Linus Lüssing
2015-06-16 12:44 ` [B.A.T.M.A.N.] [PATCHv2 maint 1/5] batman-adv: Make DAT capability changes atomic Linus Lüssing
2015-06-16 12:44 ` Linus Lüssing [this message]
2015-06-16 12:44 ` [B.A.T.M.A.N.] [PATCHv2 maint 3/5] batman-adv: Make TT " Linus Lüssing
2015-06-16 12:44 ` [B.A.T.M.A.N.] [PATCHv2 maint 4/5] batman-adv: Make MCAST " Linus Lüssing
2015-06-16 12:44 ` [B.A.T.M.A.N.] [PATCHv2 maint 5/5] batman-adv: Fix potential synchronization issues in mcast tvlv handler Linus Lüssing

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