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From: Alex Sidorenko <alexandre.sidorenko@hpe.com>
To: netdev@vger.kernel.org
Cc: eric.dumazet@gmail.com, David Miller <davem@davemloft.net>
Subject: [PATCH net v2] Fixing a bug in team driver due to incorrect 'unsigned int' to 'int' conversion
Date: Fri, 07 Oct 2016 09:02:33 -0400	[thread overview]
Message-ID: <14617987.qnk3Z4yzn3@zbook> (raw)

Roundrobin runner of team driver uses 'unsigned int' variable to count
the number of sent_packets. Later it is passed to a subroutine
team_num_to_port_index(struct team *team, int num) as 'num' and when
we reach MAXINT (2**31-1), 'num' becomes negative.

This leads to using incorrect hash-bucket for port lookup
and as a result, packets are dropped. The fix consists of changing 
'int num' to 'unsigned int num'. Testing of a fixed kernel shows that
there is no packet drop anymore.


Signed-off-by: Alex Sidorenko <alexandre.sidorenko@hpe.com>


---
v2: fixed formatting

 include/linux/if_team.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/if_team.h b/include/linux/if_team.h
index 174f43f..c05216a 100644
--- a/include/linux/if_team.h
+++ b/include/linux/if_team.h
@@ -245,7 +245,7 @@ static inline struct team_port *team_get_port_by_index(struct team *team,
 	return NULL;
 }
 
-static inline int team_num_to_port_index(struct team *team, int num)
+static inline int team_num_to_port_index(struct team *team, unsigned int num)
 {
 	int en_port_count = ACCESS_ONCE(team->en_port_count);
 
-- 
2.7.4

             reply	other threads:[~2016-10-07 13:02 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-07 13:02 Alex Sidorenko [this message]
2016-10-08  3:51 ` [PATCH net v2] Fixing a bug in team driver due to incorrect 'unsigned int' to 'int' conversion David Miller

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