Jiri Kosina 59ea33a68a tcp: perform DMA to userspace only if there is a task waiting for it ... Back in 2006, commit 1a2449a87b ("[I/OAT]: TCP recv offload to I/OAT") added support for receive offloading to IOAT dma engine if available. The code in tcp_rcv_established() tries to perform early DMA copy if applicable. It however does so without checking whether the userspace task is actually expecting the data in the buffer. This is not a problem under normal circumstances, but there is a corner case where this doesn't work -- and that's when MSG_TRUNC flag to recvmsg() is used. If the IOAT dma engine is not used, the code properly checks whether there is a valid ucopy.task and the socket is owned by userspace, but misses the check in the dmaengine case. This problem can be observed in real trivially -- for example 'tbench' is a good reproducer, as it makes a heavy use of MSG_TRUNC. On systems utilizing IOAT, you will soon find tbench waiting indefinitely in sk_wait_data(), as they have been already early-copied in tcp_rcv_established() using dma engine. This patch introduces the same check we are performing in the simple iovec copy case to the IOAT case as well. It fixes the indefinite recvmsg(MSG_TRUNC) hangs. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net>		2012-07-27 13:45:51 -07:00
..
netfilter	ipv4: Adjust semantics of rt->rt_gateway.	2012-07-20 13:31:20 -07:00
af_inet.c	net-tcp: Fast Open client - sendmsg(MSG_FASTOPEN)	2012-07-19 11:02:03 -07:00
ah4.c	ipv4: Add redirect support to all protocol icmp error handlers.	2012-07-11 21:27:49 -07:00
arp.c	ipv4: Fix input route performance regression.	2012-07-26 15:50:39 -07:00
cipso_ipv4.c	cipso: don't follow a NULL pointer when setsockopt() is called	2012-07-18 09:01:12 -07:00
datagram.c
devinet.c	ipv4: Add interface option to enable routing of 127.0.0.0/8	2012-06-12 15:25:46 -07:00
esp4.c	ipv4: Add redirect support to all protocol icmp error handlers.	2012-07-11 21:27:49 -07:00
fib_frontend.c	ipv4: Remove redundant assignment	2012-07-23 13:00:54 -07:00
fib_lookup.h
fib_rules.c	ipv4: Don't store a rule pointer in fib_result.	2012-07-13 08:21:29 -07:00
fib_semantics.c	ipv4: Fix input route performance regression.	2012-07-26 15:50:39 -07:00
fib_trie.c	ipv4: Remove tb_peers from fib_table.	2012-07-12 09:39:28 -07:00
gre.c	net: ipv4: Standardize prefixes for message logging	2012-03-12 17:05:21 -07:00
icmp.c	ipv4: Prepare for change of rt->rt_iif encoding.	2012-07-23 16:36:26 -07:00
igmp.c	ipv4: fix checkpatch errors	2012-04-15 12:37:19 -04:00
inet_connection_sock.c	ipv4: Kill FLOWI_FLAG_RT_NOCACHE and associated code.	2012-07-20 13:36:54 -07:00
inet_diag.c	net: make sock diag per-namespace	2012-07-16 22:31:34 -07:00
inet_fragment.c	inetpeer: add parameter net for inet_getpeer_v4,v6	2012-06-08 14:27:23 -07:00
inet_hashtables.c	ipv4: fix checkpatch errors	2012-04-15 12:37:19 -04:00
inet_lro.c	net: add skb frag size accessors	2011-10-19 03:10:46 -04:00
inet_timewait_sock.c	net: ipv4 and ipv6: Convert printk(KERN_DEBUG to pr_debug	2012-05-16 01:01:03 -04:00
inetpeer.c	ipv4: Maintain redirect and PMTU info in struct rtable again.	2012-07-10 22:40:14 -07:00
ip_forward.c	snmp: fix OutOctets counter to include forwarded datagrams	2012-06-07 14:50:56 -07:00
ip_fragment.c	ipv4: Fix input route performance regression.	2012-07-26 15:50:39 -07:00
ip_gre.c	ipv4: Adjust semantics of rt->rt_gateway.	2012-07-20 13:31:20 -07:00
ip_input.c	ipv6: Early TCP socket demux	2012-07-26 15:50:39 -07:00
ip_options.c	ipv4: optimize fib_compute_spec_dst call in ip_options_echo	2012-07-19 08:30:49 -07:00
ip_output.c	Merge branch 'kill_rtcache'	2012-07-22 17:04:15 -07:00
ip_sockglue.c	ipv4: Prepare for change of rt->rt_iif encoding.	2012-07-23 16:36:26 -07:00
ip_vti.c	net/ipv4/ip_vti.c: Fix __rcu warnings detected by sparse.	2012-07-23 13:00:54 -07:00
ipcomp.c	ipv4: Add redirect support to all protocol icmp error handlers.	2012-07-11 21:27:49 -07:00
ipconfig.c	net/ipv4/ipconfig: neaten __setup placement	2012-05-20 04:06:16 -04:00
ipip.c	ipv4: Adjust semantics of rt->rt_gateway.	2012-07-20 13:31:20 -07:00
ipmr.c	ipv4: Kill rt->rt_oif	2012-07-20 13:38:34 -07:00
Kconfig	net/ipv4: VTI support new module for ip_vti.	2012-07-18 09:36:12 -07:00
Makefile	net-tcp: Fast Open base	2012-07-19 10:55:36 -07:00
netfilter.c	net: Delete all remaining instances of ctl_path	2012-04-20 21:22:30 -04:00
ping.c	ipv4: Add redirect support to all protocol icmp error handlers.	2012-07-11 21:27:49 -07:00
proc.c	net-tcp: Fast Open client - sending SYN-data	2012-07-19 11:02:03 -07:00
protocol.c	inet: Sanitize inet{,6} protocol demux.	2012-06-19 18:56:21 -07:00
raw.c	ipv4: Add redirect support to all protocol icmp error handlers.	2012-07-11 21:27:49 -07:00
route.c	ipv4: Fix input route performance regression.	2012-07-26 15:50:39 -07:00
syncookies.c	net-tcp: Fast Open base	2012-07-19 10:55:36 -07:00
sysctl_net_ipv4.c	net-tcp: Fast Open base	2012-07-19 10:55:36 -07:00
tcp_bic.c	tcp: fix undo after RTO for BIC	2012-01-20 14:17:26 -05:00
tcp_cong.c	tcp: fix ABC in tcp_slow_start()	2012-07-20 10:59:41 -07:00
tcp_cubic.c	tcp: fix undo after RTO for CUBIC	2012-01-20 14:17:26 -05:00
tcp_diag.c	inet_diag: Rename inet_diag_req into inet_diag_req_v2	2012-01-11 12:56:06 -08:00
tcp_fastopen.c	net-tcp: Fast Open base	2012-07-19 10:55:36 -07:00
tcp_highspeed.c
tcp_htcp.c
tcp_hybla.c	tcp: bool conversions	2012-05-17 14:59:59 -04:00
tcp_illinois.c
tcp_input.c	tcp: perform DMA to userspace only if there is a task waiting for it	2012-07-27 13:45:51 -07:00
tcp_ipv4.c	ipv4: fix TCP early demux	2012-07-27 13:45:51 -07:00
tcp_lp.c
tcp_memcontrol.c	memcg: decrement static keys at real destroy time	2012-05-29 16:22:28 -07:00
tcp_metrics.c	tcp: avoid oops in tcp_metrics and reset tcpm_stamp	2012-07-23 00:57:12 -07:00
tcp_minisocks.c	ipv4: fix TCP early demux	2012-07-27 13:45:51 -07:00
tcp_output.c	tcp: dont drop MTU reduction indications	2012-07-23 00:58:46 -07:00
tcp_probe.c	net: cleanup unsigned to unsigned int	2012-04-15 12:44:40 -04:00
tcp_scalable.c
tcp_timer.c	tcp: improve latencies of timer triggered events	2012-07-20 10:59:41 -07:00
tcp_vegas.c
tcp_vegas.h
tcp_veno.c
tcp_westwood.c
tcp_yeah.c
tcp.c	tcp: Add TCP_USER_TIMEOUT negative value check	2012-07-27 13:45:50 -07:00
tunnel4.c	net: Convert printks to pr_<level>	2012-03-11 23:42:51 -07:00
udp_diag.c	net: make sock diag per-namespace	2012-07-16 22:31:34 -07:00
udp_impl.h	ipv4: fix checkpatch errors	2012-04-15 12:37:19 -04:00
udp.c	ipv4: Add redirect support to all protocol icmp error handlers.	2012-07-11 21:27:49 -07:00
udplite.c	net: ipv4: Standardize prefixes for message logging	2012-03-12 17:05:21 -07:00
xfrm4_input.c	ipv4: Fix input route performance regression.	2012-07-26 15:50:39 -07:00
xfrm4_mode_beet.c	ipsec: be careful of non existing mac headers	2012-02-23 16:50:45 -05:00
xfrm4_mode_transport.c
xfrm4_mode_tunnel.c	net/ipv4: VTI support rx-path hook in xfrm4_mode_tunnel.	2012-07-18 09:36:12 -07:00
xfrm4_output.c
xfrm4_policy.c	ipv4: Turn rt->rt_route_iif into rt->rt_is_input.	2012-07-20 13:40:02 -07:00
xfrm4_state.c	net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules	2011-10-31 19:30:30 -04:00
xfrm4_tunnel.c	net: ipv4: Standardize prefixes for message logging	2012-03-12 17:05:21 -07:00