kernel/linux.git/include/net/sock.h, branch v3.12.43

net: fix sparse warning in sk_dst_set()

2015-04-09T12:13:51+00:00

commit 5925a0555bdaf0b396a84318cbc21ba085f6c0d3 upstream. sk_dst_cache has __rcu annotation, so we need a cast to avoid following sparse error : include/net/sock.h:1774:19: warning: incorrect type in initializer (different address spaces) include/net/sock.h:1774:19: expected struct dst_entry [noderef] *__ret include/net/sock.h:1774:19: got struct dst_entry *dst Signed-off-by: Eric Dumazet Reported-by: kbuild test robot Fixes: 7f502361531e ("ipv4: irq safe sk_dst_[re]set() and ipv4_sk_update_pmtu() fix") Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby

tcp: fix tcp_release_cb() to dispatch via address family for mtu_reduced()

2014-10-17T07:43:12+00:00

[ Upstream commit 4fab9071950c2021d846e18351e0f46a1cffd67b ] Make sure we use the correct address-family-specific function for handling MTU reductions from within tcp_release_cb(). Previously AF_INET6 sockets were incorrectly always using the IPv6 code path when sometimes they were handling IPv4 traffic and thus had an IPv4 dst. Signed-off-by: Neal Cardwell Signed-off-by: Eric Dumazet Diagnosed-by: Willem de Bruijn Fixes: 563d34d057862 ("tcp: dont drop MTU reduction indications") Reviewed-by: Hannes Frederic Sowa Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby

ipv4: irq safe sk_dst_[re]set() and ipv4_sk_update_pmtu() fix

2014-07-29T14:56:59+00:00

[ Upstream commit 7f502361531e9eecb396cf99bdc9e9a59f7ebd7f ] We have two different ways to handle changes to sk->sk_dst First way (used by TCP) assumes socket lock is owned by caller, and use no extra lock : __sk_dst_set() & __sk_dst_reset() Another way (used by UDP) uses sk_dst_lock because socket lock is not always taken. Note that sk_dst_lock is not softirq safe. These ways are not inter changeable for a given socket type. ipv4_sk_update_pmtu(), added in linux-3.8, added a race, as it used the socket lock as synchronization, but users might be UDP sockets. Instead of converting sk_dst_lock to a softirq safe version, use xchg() as we did for sk_rx_dst in commit e47eb5dfb296b ("udp: ipv4: do not use sk_dst_lock from softirq context") In a follow up patch, we probably can remove sk_dst_lock, as it is only used in IPv6. Signed-off-by: Eric Dumazet Cc: Steffen Klassert Fixes: 9cb3a50c5f63e ("ipv4: Invalidate the socket cached route on pmtu events if possible") Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby

ipv4: fix dst race in sk_dst_get()

2014-07-29T14:56:59+00:00

[ Upstream commit f88649721268999bdff09777847080a52004f691 ] When IP route cache had been removed in linux-3.6, we broke assumption that dst entries were all freed after rcu grace period. DST_NOCACHE dst were supposed to be freed from dst_release(). But it appears we want to keep such dst around, either in UDP sockets or tunnels. In sk_dst_get() we need to make sure dst refcount is not 0 before incrementing it, or else we might end up freeing a dst twice. DST_NOCACHE set on a dst does not mean this dst can not be attached to a socket or a tunnel. Then, before actual freeing, we need to observe a rcu grace period to make sure all other cpus can catch the fact the dst is no longer usable. Signed-off-by: Eric Dumazet Reported-by: Dormando Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby

net: Add variants of capable for use on on sockets

2014-06-23T08:27:56+00:00

[ Upstream commit a3b299da869d6e78cf42ae0b1b41797bcb8c5e4b ] sk_net_capable - The common case, operations that are safe in a network namespace. sk_capable - Operations that are not known to be safe in a network namespace sk_ns_capable - The general case for special cases. Signed-off-by: "Eric W. Biederman" Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby

tcp: tcp_release_cb() should release socket ownership

2014-04-18T09:07:01+00:00

[ Upstream commit c3f9b01849ef3bc69024990092b9f42e20df7797 ] Lars Persson reported following deadlock : -000 |M:0x0:0x802B6AF8(asm) <-- arch_spin_lock -001 |tcp_v4_rcv(skb = 0x8BD527A0) <-- sk = 0x8BE6B2A0 -002 |ip_local_deliver_finish(skb = 0x8BD527A0) -003 |__netif_receive_skb_core(skb = 0x8BD527A0, ?) -004 |netif_receive_skb(skb = 0x8BD527A0) -005 |elk_poll(napi = 0x8C770500, budget = 64) -006 |net_rx_action(?) -007 |__do_softirq() -008 |do_softirq() -009 |local_bh_enable() -010 |tcp_rcv_established(sk = 0x8BE6B2A0, skb = 0x87D3A9E0, th = 0x814EBE14, ?) -011 |tcp_v4_do_rcv(sk = 0x8BE6B2A0, skb = 0x87D3A9E0) -012 |tcp_delack_timer_handler(sk = 0x8BE6B2A0) -013 |tcp_release_cb(sk = 0x8BE6B2A0) -014 |release_sock(sk = 0x8BE6B2A0) -015 |tcp_sendmsg(?, sk = 0x8BE6B2A0, ?, ?) -016 |sock_sendmsg(sock = 0x8518C4C0, msg = 0x87D8DAA8, size = 4096) -017 |kernel_sendmsg(?, ?, ?, ?, size = 4096) -018 |smb_send_kvec() -019 |smb_send_rqst(server = 0x87C4D400, rqst = 0x87D8DBA0) -020 |cifs_call_async() -021 |cifs_async_writev(wdata = 0x87FD6580) -022 |cifs_writepages(mapping = 0x852096E4, wbc = 0x87D8DC88) -023 |__writeback_single_inode(inode = 0x852095D0, wbc = 0x87D8DC88) -024 |writeback_sb_inodes(sb = 0x87D6D800, wb = 0x87E4A9C0, work = 0x87D8DD88) -025 |__writeback_inodes_wb(wb = 0x87E4A9C0, work = 0x87D8DD88) -026 |wb_writeback(wb = 0x87E4A9C0, work = 0x87D8DD88) -027 |wb_do_writeback(wb = 0x87E4A9C0, force_wait = 0) -028 |bdi_writeback_workfn(work = 0x87E4A9CC) -029 |process_one_work(worker = 0x8B045880, work = 0x87E4A9CC) -030 |worker_thread(__worker = 0x8B045880) -031 |kthread(_create = 0x87CADD90) -032 |ret_from_kernel_thread(asm) Bug occurs because __tcp_checksum_complete_user() enables BH, assuming it is running from softirq context. Lars trace involved a NIC without RX checksum support but other points are problematic as well, like the prequeue stuff. Problem is triggered by a timer, that found socket being owned by user. tcp_release_cb() should call tcp_write_timer_handler() or tcp_delack_timer_handler() in the appropriate context : BH disabled and socket lock held, but 'owned' field cleared, as if they were running from timer handlers. Fixes: 6f458dfb4092 ("tcp: improve latencies of timer triggered events") Reported-by: Lars Persson Tested-by: Lars Persson Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby

net: fix unsafe set_memory_rw from softirq

2013-10-07T19:16:45+00:00

on x86 system with net.core.bpf_jit_enable = 1 sudo tcpdump -i eth1 'tcp port 22' causes the warning: [ 56.766097] Possible unsafe locking scenario: [ 56.766097] [ 56.780146] CPU0 [ 56.786807] ---- [ 56.793188] lock(&(&vb->lock)->rlock); [ 56.799593] [ 56.805889] lock(&(&vb->lock)->rlock); [ 56.812266] [ 56.812266] *** DEADLOCK *** [ 56.812266] [ 56.830670] 1 lock held by ksoftirqd/1/13: [ 56.836838] #0: (rcu_read_lock){.+.+..}, at: [] vm_unmap_aliases+0x8c/0x380 [ 56.849757] [ 56.849757] stack backtrace: [ 56.862194] CPU: 1 PID: 13 Comm: ksoftirqd/1 Not tainted 3.12.0-rc3+ #45 [ 56.868721] Hardware name: System manufacturer System Product Name/P8Z77 WS, BIOS 3007 07/26/2012 [ 56.882004] ffffffff821944c0 ffff88080bbdb8c8 ffffffff8175a145 0000000000000007 [ 56.895630] ffff88080bbd5f40 ffff88080bbdb928 ffffffff81755b14 0000000000000001 [ 56.909313] ffff880800000001 ffff880800000000 ffffffff8101178f 0000000000000001 [ 56.923006] Call Trace: [ 56.929532] [] dump_stack+0x55/0x76 [ 56.936067] [] print_usage_bug+0x1f7/0x208 [ 56.942445] [] ? save_stack_trace+0x2f/0x50 [ 56.948932] [] ? check_usage_backwards+0x150/0x150 [ 56.955470] [] mark_lock+0x282/0x2c0 [ 56.961945] [] __lock_acquire+0x45d/0x1d50 [ 56.968474] [] ? __lock_acquire+0x2de/0x1d50 [ 56.975140] [] ? cpumask_next_and+0x55/0x90 [ 56.981942] [] lock_acquire+0x92/0x1d0 [ 56.988745] [] ? vm_unmap_aliases+0x16a/0x380 [ 56.995619] [] _raw_spin_lock+0x41/0x50 [ 57.002493] [] ? vm_unmap_aliases+0x16a/0x380 [ 57.009447] [] vm_unmap_aliases+0x16a/0x380 [ 57.016477] [] ? vm_unmap_aliases+0x8c/0x380 [ 57.023607] [] change_page_attr_set_clr+0xc0/0x460 [ 57.030818] [] ? trace_hardirqs_on+0xd/0x10 [ 57.037896] [] ? kmem_cache_free+0xb0/0x2b0 [ 57.044789] [] ? free_object_rcu+0x93/0xa0 [ 57.051720] [] set_memory_rw+0x2f/0x40 [ 57.058727] [] bpf_jit_free+0x2c/0x40 [ 57.065577] [] sk_filter_release_rcu+0x1a/0x30 [ 57.072338] [] rcu_process_callbacks+0x202/0x7c0 [ 57.078962] [] __do_softirq+0xf7/0x3f0 [ 57.085373] [] run_ksoftirqd+0x35/0x70 cannot reuse jited filter memory, since it's readonly, so use original bpf insns memory to hold work_struct defer kfree of sk_filter until jit completed freeing tested on x86_64 and i386 Signed-off-by: Alexei Starovoitov Acked-by: Eric Dumazet Signed-off-by: David S. Miller

vxlan: Use RCU apis to access sk_user_data.

2013-09-30T18:22:59+00:00

Use of RCU api makes vxlan code easier to understand. It also fixes bug due to missing ACCESS_ONCE() on sk_user_data dereference. In rare case without ACCESS_ONCE() compiler might omit vs on sk_user_data dereference. Compiler can use vs as alias for sk->sk_user_data, resulting in multiple sk_user_data dereference in rcu read context which could change. CC: Jesse Gross Signed-off-by: Pravin B Shelar Signed-off-by: David S. Miller

tcp: TSO packets automatic sizing

2013-08-29T19:50:06+00:00

After hearing many people over past years complaining against TSO being bursty or even buggy, we are proud to present automatic sizing of TSO packets. One part of the problem is that tcp_tso_should_defer() uses an heuristic relying on upcoming ACKS instead of a timer, but more generally, having big TSO packets makes little sense for low rates, as it tends to create micro bursts on the network, and general consensus is to reduce the buffering amount. This patch introduces a per socket sk_pacing_rate, that approximates the current sending rate, and allows us to size the TSO packets so that we try to send one packet every ms. This field could be set by other transports. Patch has no impact for high speed flows, where having large TSO packets makes sense to reach line rate. For other flows, this helps better packet scheduling and ACK clocking. This patch increases performance of TCP flows in lossy environments. A new sysctl (tcp_min_tso_segs) is added, to specify the minimal size of a TSO packet (default being 2). A follow-up patch will provide a new packet scheduler (FQ), using sk_pacing_rate as an input to perform optional per flow pacing. This explains why we chose to set sk_pacing_rate to twice the current rate, allowing 'slow start' ramp up. sk_pacing_rate = 2 * cwnd * mss / srtt v2: Neal Cardwell reported a suspect deferring of last two segments on initial write of 10 MSS, I had to change tcp_tso_should_defer() to take into account tp->xmit_size_goal_segs Signed-off-by: Eric Dumazet Cc: Neal Cardwell Cc: Yuchung Cheng Cc: Van Jacobson Cc: Tom Herbert Acked-by: Yuchung Cheng Acked-by: Neal Cardwell Signed-off-by: David S. Miller

net: attempt high order allocations in sock_alloc_send_pskb()

2013-08-10T08:16:44+00:00

Adding paged frags skbs to af_unix sockets introduced a performance regression on large sends because of additional page allocations, even if each skb could carry at least 100% more payload than before. We can instruct sock_alloc_send_pskb() to attempt high order allocations. Most of the time, it does a single page allocation instead of 8. I added an additional parameter to sock_alloc_send_pskb() to let other users to opt-in for this new feature on followup patches. Tested: Before patch : $ netperf -t STREAM_STREAM STREAM STREAM TEST Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 2304 212992 212992 10.00 46861.15 After patch : $ netperf -t STREAM_STREAM STREAM STREAM TEST Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 2304 212992 212992 10.00 57981.11 Signed-off-by: Eric Dumazet Cc: David Rientjes Signed-off-by: David S. Miller