linux/net, branch v3.2.18

pktgen: fix module unload for good

2012-05-20T21:56:53Z

commit d4b1133558e0d417342d5d2c49e4c35b428ff20d upstream. commit c57b5468406 (pktgen: fix crash at module unload) did a very poor job with list primitives. 1) list_splice() arguments were in the wrong order 2) list_splice(list, head) has undefined behavior if head is not initialized. 3) We should use the list_splice_init() variant to clear pktgen_threads list. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings

pktgen: fix crash at module unload

2012-05-20T21:56:53Z

commit c57b54684060c8aced64a5b78ff69ff289af97b9 upstream. commit 7d3d43dab4e9 (net: In unregister_netdevice_notifier unregister the netdevices.) makes pktgen crashing at module unload. [ 296.820578] BUG: spinlock bad magic on CPU#6, rmmod/3267 [ 296.820719] lock: ffff880310c38000, .magic: ffff8803, .owner: /-1, .owner_cpu: -1 [ 296.820943] Pid: 3267, comm: rmmod Not tainted 3.4.0-rc5+ #254 [ 296.821079] Call Trace: [ 296.821211] [] spin_dump+0x8a/0x8f [ 296.821345] [] spin_bug+0x21/0x26 [ 296.821507] [] do_raw_spin_lock+0x131/0x140 [ 296.821648] [] _raw_spin_lock+0x1e/0x20 [ 296.821786] [] __pktgen_NN_threads+0x4d/0x140 [pktgen] [ 296.821928] [] pktgen_device_event+0x10d/0x1e0 [pktgen] [ 296.822073] [] unregister_netdevice_notifier+0x7f/0x100 [ 296.822216] [] pg_cleanup+0x48/0x73 [pktgen] [ 296.822357] [] sys_delete_module+0x17e/0x2a0 [ 296.822502] [] system_call_fastpath+0x16/0x1b Hold the pktgen_thread_lock while splicing pktgen_threads, and test pktgen_exiting in pktgen_device_event() to make unload faster. Signed-off-by: Eric Dumazet Cc: Eric W. Biederman Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings

tcp: do_tcp_sendpages() must try to push data out on oom conditions

2012-05-20T21:56:51Z

commit bad115cfe5b509043b684d3a007ab54b80090aa1 upstream. Since recent changes on TCP splicing (starting with commits 2f533844 "tcp: allow splice() to build full TSO packets" and 35f9c09f "tcp: tcp_sendpages() should call tcp_push() once"), I started seeing massive stalls when forwarding traffic between two sockets using splice() when pipe buffers were larger than socket buffers. Latest changes (net: netdev_alloc_skb() use build_skb()) made the problem even more apparent. The reason seems to be that if do_tcp_sendpages() fails on out of memory condition without being able to send at least one byte, tcp_push() is not called and the buffers cannot be flushed. After applying the attached patch, I cannot reproduce the stalls at all and the data rate it perfectly stable and steady under any condition which previously caused the problem to be permanent. The issue seems to have been there since before the kernel migrated to git, which makes me think that the stalls I occasionally experienced with tux during stress-tests years ago were probably related to the same issue. This issue was first encountered on 3.0.31 and 3.2.17, so please backport to -stable. Signed-off-by: Willy Tarreau Acked-by: Eric Dumazet Signed-off-by: Ben Hutchings

tcp: change tcp_adv_win_scale and tcp_rmem[2]

2012-05-20T21:56:38Z

[ Upstream commit b49960a05e32121d29316cfdf653894b88ac9190 ] tcp_adv_win_scale default value is 2, meaning we expect a good citizen skb to have skb->len / skb->truesize ratio of 75% (3/4) In 2.6 kernels we (mis)accounted for typical MSS=1460 frame : 1536 + 64 + 256 = 1856 'estimated truesize', and 1856 * 3/4 = 1392. So these skbs were considered as not bloated. With recent truesize fixes, a typical MSS=1460 frame truesize is now the more precise : 2048 + 256 = 2304. But 2304 * 3/4 = 1728. So these skb are not good citizen anymore, because 1460 < 1728 (GRO can escape this problem because it build skbs with a too low truesize.) This also means tcp advertises a too optimistic window for a given allocated rcvspace : When receiving frames, sk_rmem_alloc can hit sk_rcvbuf limit and we call tcp_prune_queue()/tcp_collapse() too often, especially when application is slow to drain its receive queue or in case of losses (netperf is fast, scp is slow). This is a major latency source. We should adjust the len/truesize ratio to 50% instead of 75% This patch : 1) changes tcp_adv_win_scale default to 1 instead of 2 2) increase tcp_rmem[2] limit from 4MB to 6MB to take into account better truesize tracking and to allow autotuning tcp receive window to reach same value than before. Note that same amount of kernel memory is consumed compared to 2.6 kernels. Signed-off-by: Eric Dumazet Cc: Neal Cardwell Cc: Tom Herbert Cc: Yuchung Cheng Acked-by: Neal Cardwell Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings

tcp: fix infinite cwnd in tcp_complete_cwr()

2012-05-20T21:56:37Z

[ Upstream commit 1cebce36d660c83bd1353e41f3e66abd4686f215 ] When the cwnd reduction is done, ssthresh may be infinite if TCP enters CWR via ECN or F-RTO. If cwnd is not undone, i.e., undo_marker is set, tcp_complete_cwr() falsely set cwnd to the infinite ssthresh value. The correct operation is to keep cwnd intact because it has been updated in ECN or F-RTO. Signed-off-by: Yuchung Cheng Acked-by: Neal Cardwell Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings

net: l2tp: unlock socket lock before returning from l2tp_ip_sendmsg

2012-05-20T21:56:35Z

[ Upstream commit 84768edbb2721637620b2d84501bb0d5aed603f1 ] l2tp_ip_sendmsg could return without releasing socket lock, making it all the way to userspace, and generating the following warning: [ 130.891594] ================================================ [ 130.894569] [ BUG: lock held when returning to user space! ] [ 130.897257] 3.4.0-rc5-next-20120501-sasha #104 Tainted: G W [ 130.900336] ------------------------------------------------ [ 130.902996] trinity/8384 is leaving the kernel with locks still held! [ 130.906106] 1 lock held by trinity/8384: [ 130.907924] #0: (sk_lock-AF_INET){+.+.+.}, at: [] l2tp_ip_sendmsg+0x2f/0x550 Introduced by commit 2f16270 ("l2tp: Fix locking in l2tp_ip.c"). Signed-off-by: Sasha Levin Acked-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings

net: In unregister_netdevice_notifier unregister the netdevices.

2012-05-20T21:56:34Z

[ Upstream commit 7d3d43dab4e978d8d9ad1acf8af15c9b1c4b0f0f ] We already synthesize events in register_netdevice_notifier and synthesizing events in unregister_netdevice_notifier allows to us remove the need for special case cleanup code. This change should be safe as it adds no new cases for existing callers of unregiser_netdevice_notifier to handle. Signed-off-by: Eric W. Biederman Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings

netem: fix possible skb leak

2012-05-20T21:56:34Z

[ Upstream commit 116a0fc31c6c9b8fc821be5a96e5bf0b43260131 ] skb_checksum_help(skb) can return an error, we must free skb in this case. qdisc_drop(skb, sch) can also be feeded with a NULL skb (if skb_unshare() failed), so lets use this generic helper. Signed-off-by: Eric Dumazet Cc: Stephen Hemminger Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings

mac80211: fix AP mode EAP tx for VLAN stations

2012-05-11T12:14:54Z

commit 66f2c99af3d6f2d0aa1120884cf1c60613ef61c0 upstream. EAP frames for stations in an AP VLAN are sent on the main AP interface to avoid race conditions wrt. moving stations. For that to work properly, sta_info_get_bss must be used instead of sta_info_get when sending EAP packets. Previously this was only done for cooked monitor injected packets, so this patch adds a check for tx->skb->protocol to the same place. Signed-off-by: Felix Fietkau Signed-off-by: John W. Linville Signed-off-by: Ben Hutchings

nl80211: ensure interface is up in various APIs

2012-05-11T12:14:40Z

commit 2b5f8b0b44e17e625cfba1e7b88db44f4dcc0441 upstream. [backported by Ben Greear] The nl80211 handling code should ensure as much as it can that the interface is in a valid state, it can certainly ensure the interface is running. Not doing so can cause calls through mac80211 into the driver that result in warnings and unspecified behaviour in the driver. Reported-by: Ben Greear Signed-off-by: Johannes Berg Signed-off-by: John W. Linville Signed-off-by: Ben Greear Signed-off-by: Ben Hutchings