Jiri Olsa
a57de0b433
net: adding memory barrier to the poll and receive callbacks ...
Adding memory barrier after the poll_wait function, paired with
receive callbacks. Adding fuctions sock_poll_wait and sk_has_sleeper
to wrap the memory barrier.
Without the memory barrier, following race can happen.
The race fires, when following code paths meet, and the tp->rcv_nxt
and __add_wait_queue updates stay in CPU caches.
CPU1 CPU2
sys_select receive packet
... ...
__add_wait_queue update tp->rcv_nxt
... ...
tp->rcv_nxt check sock_def_readable
... {
schedule ...
if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
wake_up_interruptible(sk->sk_sleep)
...
}
If there was no cache the code would work ok, since the wait_queue and
rcv_nxt are opposit to each other.
Meaning that once tp->rcv_nxt is updated by CPU2, the CPU1 either already
passed the tp->rcv_nxt check and sleeps, or will get the new value for
tp->rcv_nxt and will return with new data mask.
In both cases the process (CPU1) is being added to the wait queue, so the
waitqueue_active (CPU2) call cannot miss and will wake up CPU1.
The bad case is when the __add_wait_queue changes done by CPU1 stay in its
cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1 will then
endup calling schedule and sleep forever if there are no more data on the
socket.
Calls to poll_wait in following modules were ommited:
net/bluetooth/af_bluetooth.c
net/irda/af_irda.c
net/irda/irnet/irnet_ppp.c
net/mac80211/rc80211_pid_debugfs.c
net/phonet/socket.c
net/rds/af_rds.c
net/rfkill/core.c
net/sunrpc/cache.c
net/sunrpc/rpc_pipe.c
net/tipc/socket.c
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-09 17:06:57 -07:00
net/9p: handle correctly interrupted 9P requests
2009-04-05 16:54:53 -05:00
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/holtmann/bluetooth-next-2.6
2009-06-11 05:47:43 -07:00
net: add NL802154 interface for configuration of 802.15.4 devices
2009-06-09 05:25:33 -07:00
irda: Add irda_skb_cb qdisc related padding
2008-12-17 15:44:58 -08:00
af_iucv: Return -EAGAIN if iucv msg limit is exceeded
2009-06-19 00:10:40 -07:00
netfilter: tcp conntrack: fix unacknowledged data detection with NAT
2009-06-29 14:07:56 +02:00
netfilter: conntrack: optional reliable conntrack event delivery
2009-06-13 12:30:52 +02:00
Phonet: publicize the Netlink notification function
2009-06-25 02:58:15 -07:00
net: Move rx skb_orphan call to where needed
2009-06-23 16:36:25 -07:00
pkt_action: add new action skbedit
2008-09-12 16:30:20 -07:00
tipc: Remove unneeded parameter to tipc_createport_raw()
2008-07-14 22:42:19 -07:00
ipv6: Fix conflict resolutions during ipv6 binding
2009-03-24 19:49:11 -07:00
net: Fix soft lockups/OOM issues w/ unix garbage collector
2008-11-26 15:32:27 -08:00
clip: convert to internal network_device_stats
2009-01-21 14:01:59 -08:00
ax88796: Add method to take MAC from platform data
2009-03-24 23:32:03 -07:00
cfg80211: add rfkill support
2009-06-03 14:06:14 -04:00
include/net net/ - csum_partial - remove unnecessary casts
2008-11-19 15:44:53 -08:00
netlabel: Label incoming TCP connections correctly in SELinux
2009-03-28 15:01:36 +11:00
net: Use standard structures for generic socket address structures.
2008-07-19 22:35:47 -07:00
net: fix DCB setstate to return success/failure
2008-12-21 20:09:50 -08:00
decnet: compile fix for removal of byteorder wrapper
2008-11-27 23:04:13 -08:00
decnet: remove private wrappers of endian helpers
2008-11-27 00:12:47 -08:00
dsa: add switch chip cascading support
2009-03-21 19:06:54 -07:00
net: skb->dst accessors
2009-06-03 02:51:04 -07:00
net: Add support for the OpenCores 10/100 Mbps Ethernet MAC.
2009-03-27 00:16:21 -07:00
net: Remove unused parameter from fill method in fib_rules_ops.
2009-05-20 17:26:23 -07:00
netns xfrm: lookup in netns
2008-11-25 17:35:18 -08:00
pkt_sched: gen_estimator: Optimize gen_estimator_active()
2008-11-26 15:24:32 -08:00
genetlink: Introduce genl_register_family_with_ops()
2009-05-21 16:50:22 -07:00
mib: put icmpmsg statistics on struct net
2008-07-18 04:04:22 -07:00
wireless: radiotap updates
2009-03-27 20:12:52 -04:00
ipv6: reorder struct inet6_ifaddr to remove padding on 64 bit builds
2009-03-21 13:29:05 -07:00
net: skb->dst accessors
2009-06-03 02:51:04 -07:00
net: more #ifdef CONFIG_COMPAT
2008-08-28 02:53:51 -07:00
net: replace __constant_{endian} uses in net headers
2009-02-14 22:58:35 -08:00
inet fragments: fix sparse warning: context imbalance
2009-02-26 23:13:35 -08:00
net: skb->dst accessors
2009-06-03 02:51:04 -07:00
Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/vegard/kmemcheck
2009-06-16 13:09:51 -07:00
net: annotate inet_timewait_sock bitfields
2009-06-15 15:49:32 +02:00
snmp: add missing counters for RFC 4293
2009-04-27 02:45:02 -07:00
net: skb->dst accessors
2009-06-03 02:51:04 -07:00
ipv4: remove unused macro (FIB_RES_RESET) from ip_fib.h.
2009-05-03 14:19:51 -07:00
net: replace __constant_{endian} uses in net headers
2009-02-14 22:58:35 -08:00
ipsec: ipcomp - Merge IPComp implementations
2008-07-25 02:54:40 -07:00
sit: stateless autoconf for isatap
2009-05-19 16:02:02 -07:00
snmp: add missing counters for RFC 4293
2009-04-27 02:45:02 -07:00
net: replace __constant_{endian} uses in net headers
2009-02-14 22:58:35 -08:00
wireless: missing include in lib80211.h
2008-11-21 11:42:55 -05:00
mac80211: do not pass PS frames out of mac80211 again
2009-06-10 13:28:37 -04:00
ipv6: Fix sporadic sendmsg -EINVAL when sending to multicast groups.
2009-01-04 16:04:39 -08:00
net: Cleanup of neighbour code
2008-11-12 00:54:54 -08:00
netns: Remove net_alive
2009-03-03 01:14:27 -08:00
net_dma: convert to dma_find_channel
2009-01-06 11:38:15 -07:00
netlabel: Cleanup the Smack/NetLabel code to fix incoming TCP connections
2009-03-28 15:01:37 +11:00
netfilter: conntrack: add support for DCCP handshake sequence to ctnetlink
2009-05-27 17:50:35 +02:00
netrom: convert to internal net_device_stats
2009-01-21 14:02:01 -08:00
ematch: simpler tcf_em_unregister()
2008-11-16 23:01:49 -08:00
pkt_sched: Rename PSCHED_US2NS and PSCHED_NS2US
2009-06-15 02:31:47 -07:00
ipv6: Use correct data types for ICMPv6 type and code
2009-06-23 04:31:07 -07:00
snap: use const for descriptor
2009-03-21 19:06:50 -07:00
ipv6: Use correct data types for ICMPv6 type and code
2009-06-23 04:31:07 -07:00
cfg80211: clean up includes
2009-04-22 16:57:17 -04:00
net: Fix memory leak in the proto_register function
2008-11-21 16:45:22 -08:00
net: skb->rtable accessor
2009-06-03 02:51:02 -07:00
net: reorder struct Qdisc for better SMP performance
2009-03-20 01:33:32 -07:00
Merge branch 'master' into next
2008-11-14 11:29:12 +11:00
snmp: add missing counters for RFC 4293
2009-04-27 02:45:02 -07:00
net: adding memory barrier to the poll and receive callbacks
2009-07-09 17:06:57 -07:00
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
2009-05-08 02:48:30 -07:00
net: Fix memory leak in the proto_register function
2008-11-21 16:45:22 -08:00
net: replace __constant_{endian} uses in net headers
2009-02-14 22:58:35 -08:00
ipv6: Fix NULL pointer dereference with time-wait sockets
2009-04-11 01:53:06 -07:00
udp: introduce struct udp_table and multiple spinlocks
2008-10-29 01:41:45 -07:00
rfkill: rewrite
2009-06-03 14:06:13 -04:00
x25: Fix sleep from timer on socket destroy.
2009-06-16 05:40:30 -07:00
ipv6: Use correct data types for ICMPv6 type and code
2009-06-23 04:31:07 -07:00
a57de0b433