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| author | Schoch Christian <e0326715@student.tuwien.ac.at> | 2012-11-28 05:18:29 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-11-28 11:13:40 -0500 |
| commit | 92d64c261e77cb2a6117887617e2a629fea6b67c (patch) | |
| tree | 0021d03d1c34acb7ab099ad66bbec6f28d658613 /net | |
| parent | 6e51fe7572590d8d86e93b547fab6693d305fd0d (diff) | |
| download | linux-3.10-92d64c261e77cb2a6117887617e2a629fea6b67c.tar.gz linux-3.10-92d64c261e77cb2a6117887617e2a629fea6b67c.tar.bz2 linux-3.10-92d64c261e77cb2a6117887617e2a629fea6b67c.zip | |
sctp: Error in calculation of RTTvar
The calculation of RTTVAR involves the subtraction of two unsigned
numbers which
may causes rollover and results in very high values of RTTVAR when RTT > SRTT.
With this patch it is possible to set RTOmin = 1 to get the minimum of RTO at
4 times the clock granularity.
Change Notes:
v2)
*Replaced abs() by abs64() and long by __s64, changed patch
description.
Signed-off-by: Christian Schoch <e0326715@student.tuwien.ac.at>
CC: Vlad Yasevich <vyasevich@gmail.com>
CC: Sridhar Samudrala <sri@us.ibm.com>
CC: Neil Horman <nhorman@tuxdriver.com>
CC: linux-sctp@vger.kernel.org
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/sctp/transport.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/sctp/transport.c b/net/sctp/transport.c index 953c21e4af9..206cf5238fd 100644 --- a/net/sctp/transport.c +++ b/net/sctp/transport.c @@ -331,7 +331,7 @@ void sctp_transport_update_rto(struct sctp_transport *tp, __u32 rtt) * 1/8, rto_alpha would be expressed as 3. */ tp->rttvar = tp->rttvar - (tp->rttvar >> net->sctp.rto_beta) - + ((abs(tp->srtt - rtt)) >> net->sctp.rto_beta); + + (((__u32)abs64((__s64)tp->srtt - (__s64)rtt)) >> net->sctp.rto_beta); tp->srtt = tp->srtt - (tp->srtt >> net->sctp.rto_alpha) + (rtt >> net->sctp.rto_alpha); } else { |