Jiri Kosina 2ce42ec4ef tcp: perform DMA to userspace only if there is a task waiting for it ... [ Upstream commit 59ea33a68a ] 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2012-08-09 08:31:51 -07:00
..
netfilter	netfilter: nf_ct_ipv4: packets with wrong ihl are invalid	2012-04-10 12:50:49 +02:00
af_inet.c	Remove all #inclusions of asm/system.h	2012-03-28 18:30:03 +01:00
ah4.c	net: ipv4: Standardize prefixes for message logging	2012-03-12 17:05:21 -07:00
arp.c	Remove all #inclusions of asm/system.h	2012-03-28 18:30:03 +01:00
cipso_ipv4.c	cipso: don't follow a NULL pointer when setsockopt() is called	2012-08-09 08:31:42 -07:00
datagram.c	ipv4: Lock socket and use cork flow in ip4_datagram_connect().	2011-05-08 13:48:57 -07:00
devinet.c	Disintegrate and delete asm/system.h	2012-03-28 15:58:21 -07:00
esp4.c	xfrm: take net hdr len into account for esp payload size calculation	2012-06-10 00:36:15 +09:00
fib_frontend.c	Remove all #inclusions of asm/system.h	2012-03-28 18:30:03 +01:00
fib_lookup.h	ipv4: Fix nexthop caching wrt. scoping.	2011-03-24 18:06:47 -07:00
fib_rules.c	net: ipv4: export fib_lookup and fib_table_lookup	2011-12-04 22:43:33 +01:00
fib_semantics.c	ipv4: fix the rcu race between free_fib_info and ip_route_output_slow	2012-06-10 00:36:14 +09:00
fib_trie.c	ipv4: Do not use dead fib_info entries.	2012-05-10 22:16:32 -04:00
gre.c	net: ipv4: Standardize prefixes for message logging	2012-03-12 17:05:21 -07:00
icmp.c	Remove all #inclusions of asm/system.h	2012-03-28 18:30:03 +01:00
igmp.c	Remove all #inclusions of asm/system.h	2012-03-28 18:30:03 +01:00
inet_connection_sock.c	tcp: bind() optimize port allocation	2012-01-25 21:50:43 -05:00
inet_diag.c	udp_diag: implement idiag_get_info for udp/udplite to get queue information	2012-04-25 20:43:01 -04:00
inet_fragment.c
inet_hashtables.c	net: Compute protocol sequence numbers and fragment IDs using MD5.	2011-08-06 18:33:19 -07:00
inet_lro.c	net: add skb frag size accessors	2011-10-19 03:10:46 -04:00
inet_timewait_sock.c	net: Fix files explicitly needing to include module.h	2011-10-31 19:30:28 -04:00
inetpeer.c	inetpeer: fix a race in inetpeer_gc_worker()	2012-07-16 09:03:45 -07:00
ip_forward.c	ipv4: Save nexthop address of LSRR/SSRR option to IPCB.	2011-11-23 19:19:32 -05:00
ip_fragment.c	net: ipv4: Standardize prefixes for message logging	2012-03-12 17:05:21 -07:00
ip_gre.c	net: ipv4: Standardize prefixes for message logging	2012-03-12 17:05:21 -07:00
ip_input.c	Remove all #inclusions of asm/system.h	2012-03-28 18:30:03 +01:00
ip_options.c	net: ipv4: Standardize prefixes for message logging	2012-03-12 17:05:21 -07:00
ip_output.c	Remove all #inclusions of asm/system.h	2012-03-28 18:30:03 +01:00
ip_sockglue.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2012-03-20 21:04:47 -07:00
ipcomp.c	net: Convert printks to pr_<level>	2012-03-11 23:42:51 -07:00
ipconfig.c	net: Convert printks to pr_<level>	2012-03-11 23:42:51 -07:00
ipip.c	net: Convert printks to pr_<level>	2012-03-11 23:42:51 -07:00
ipmr.c	Remove all #inclusions of asm/system.h	2012-03-28 18:30:03 +01:00
Kconfig	net: Fix build regression when INET_UDP_DIAG=y and IPV6=m	2012-02-07 13:35:28 -05:00
Makefile	tcp memory pressure controls	2011-12-12 19:04:10 -05:00
netfilter.c	netfilter: possible unaligned packet header in ip_route_me_harder	2011-11-21 18:46:18 +01:00
ping.c	Remove all #inclusions of asm/system.h	2012-03-28 18:30:03 +01:00
proc.c	tcp: reduce out_of_order memory use	2012-03-19 16:53:08 -04:00
protocol.c
raw.c	net: Convert printks to pr_<level>	2012-03-11 23:42:51 -07:00
route.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2012-04-02 17:53:39 -07:00
syncookies.c	tcp: fix syncookie regression	2012-03-11 15:52:12 -07:00
sysctl_net_ipv4.c	tcp: properly initialize tcp memory limits	2012-02-02 14:34:41 -05:00
tcp_bic.c	tcp: fix undo after RTO for BIC	2012-01-20 14:17:26 -05:00
tcp_cong.c	net: ipv4: Standardize prefixes for message logging	2012-03-12 17:05:21 -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_highspeed.c	tcp: mark tcp_congestion_ops read_mostly	2011-03-10 00:40:17 -08:00
tcp_htcp.c	tcp: mark tcp_congestion_ops read_mostly	2011-03-10 00:40:17 -08:00
tcp_hybla.c	tcp: mark tcp_congestion_ops read_mostly	2011-03-10 00:40:17 -08:00
tcp_illinois.c	tcp: mark tcp_congestion_ops read_mostly	2011-03-10 00:40:17 -08:00
tcp_input.c	tcp: perform DMA to userspace only if there is a task waiting for it	2012-08-09 08:31:51 -07:00
tcp_ipv4.c	dmaengine-fixes for 3.4-rc3	2012-04-10 15:30:16 -07:00
tcp_lp.c	Fix common misspellings	2011-03-31 11:26:23 -03:00
tcp_memcontrol.c	Merge branch 'for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2012-03-20 18:11:21 -07:00
tcp_minisocks.c	tcp: md5: rcu conversion	2012-01-31 12:14:00 -05:00
tcp_output.c	tcp: fix retransmit of partially acked frames	2012-04-18 16:52:45 -04:00
tcp_probe.c	net: ipv4: Standardize prefixes for message logging	2012-03-12 17:05:21 -07:00
tcp_scalable.c	tcp: mark tcp_congestion_ops read_mostly	2011-03-10 00:40:17 -08:00
tcp_timer.c	net: ipv4: Standardize prefixes for message logging	2012-03-12 17:05:21 -07:00
tcp_vegas.c	tcp: mark tcp_congestion_ops read_mostly	2011-03-10 00:40:17 -08:00
tcp_vegas.h
tcp_veno.c	tcp: mark tcp_congestion_ops read_mostly	2011-03-10 00:40:17 -08:00
tcp_westwood.c	tcp: mark tcp_congestion_ops read_mostly	2011-03-10 00:40:17 -08:00
tcp_yeah.c	Fix common misspellings	2011-03-31 11:26:23 -03:00
tcp.c	tcp: Add TCP_USER_TIMEOUT negative value check	2012-08-09 08:31:51 -07:00
tunnel4.c	net: Convert printks to pr_<level>	2012-03-11 23:42:51 -07:00
udp_diag.c	udp_diag: implement idiag_get_info for udp/udplite to get queue information	2012-04-25 20:43:01 -04:00
udp_impl.h
udp.c	Remove all #inclusions of asm/system.h	2012-03-28 18:30:03 +01:00
udplite.c	net: ipv4: Standardize prefixes for message logging	2012-03-12 17:05:21 -07:00
xfrm4_input.c
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	ipsec: be careful of non existing mac headers	2012-02-23 16:50:45 -05:00
xfrm4_output.c	xfrm4: Don't call icmp_send on local error	2011-07-01 17:33:19 -07:00
xfrm4_policy.c	ipv4: fix ipsec forward performance regression	2011-10-24 03:01:22 -04:00
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