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This is currently done for CMSG_INQ, add an ability to do so via struct
msghdr as well and have CMSG_INQ use that too. If the caller sets
msghdr->msg_get_inq, then we'll pass back the hint in msghdr->msg_inq.
Rearrange struct msghdr a bit so we can add this member while shrinking
it at the same time. On a 64-bit build, it was 96 bytes before this
change and 88 bytes afterwards.
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/650c22ca-cffc-0255-9a05-2413a1e20826@kernel.dk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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tcp_should_autocork() is evaluating if it makes senses
to not immediately send current skb, hoping that
user space will add more payload on it by the
time TCP stack reacts to upcoming TX completions.
If current skb got MSG_EOR mark, then we know
that no further data will be added, it is therefore
futile to wait.
SOF_TIMESTAMPING_TX_ACK will become a bit more accurate,
if prior packets are still in qdisc/device queues.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Willem de Bruijn <willemb@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Link: https://lore.kernel.org/r/20220309054706.2857266-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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We have a number of cases where function returns drop/no drop
decision as a boolean. Now that we want to report the reason
code as well we have to pass extra output arguments.
We can make the reason code evaluate correctly as bool.
I believe we're good to reorder the reasons as they are
reported to user space as strings.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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net/batman-adv/hard-interface.c
commit 690bb6fb64f5 ("batman-adv: Request iflink once in batadv-on-batadv check")
commit 6ee3c393eeb7 ("batman-adv: Demote batadv-on-batadv skip error message")
https://lore.kernel.org/all/20220302163049.101957-1-sw@simonwunderlich.de/
net/smc/af_smc.c
commit 4d08b7b57ece ("net/smc: Fix cleanup when register ULP fails")
commit 462791bbfa35 ("net/smc: add sysctl interface for SMC")
https://lore.kernel.org/all/20220302112209.355def40@canb.auug.org.au/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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If recv_actor() returns an incorrect value, tcp_read_sock()
might loop forever.
Instead, issue a one time warning and make sure to make progress.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20220302161723.3910001-2-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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The functions do essentially the same work to verify TCP-MD5 sign.
Code can be merged into one family-independent function in order to
reduce copy'n'paste and generated code.
Later with TCP-AO option added, this will allow to create one function
that's responsible for segment verification, that will have all the
different checks for MD5/AO/non-signed packets, which in turn will help
to see checks for all corner-cases in one function, rather than spread
around different families and functions.
Cc: Eric Dumazet <edumazet@google.com>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20220223175740.452397-1-dima@arista.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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No conflicts.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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syzbot found that mixing sendpage() and sendmsg(MSG_ZEROCOPY)
calls over the same TCP socket would again trigger the
infamous warning in inet_sock_destruct()
WARN_ON(sk_forward_alloc_get(sk));
While Talal took into account a mix of regular copied data
and MSG_ZEROCOPY one in the same skb, the sendpage() path
has been forgotten.
We want the charging to happen for sendpage(), because
pages could be coming from a pipe. What is missing is the
downgrading of pure zerocopy status to make sure
sk_forward_alloc will stay synced.
Add tcp_downgrade_zcopy_pure() helper so that we can
use it from the two callers.
Fixes: 9b65b17db723 ("net: avoid double accounting for pure zerocopy skbs")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Talal Ahmad <talalahmad@google.com>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Link: https://lore.kernel.org/r/20220203225547.665114-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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No conflicts.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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We got reports of following warning in inet_sock_destruct()
WARN_ON(sk_forward_alloc_get(sk));
Whenever we add a non zero-copy fragment to a pure zerocopy skb,
we have to anticipate that whole skb->truesize will be uncharged
when skb is finally freed.
skb->data_len is the payload length. But the memory truesize
estimated by __zerocopy_sg_from_iter() is page aligned.
Fixes: 9b65b17db723 ("net: avoid double accounting for pure zerocopy skbs")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Talal Ahmad <talalahmad@google.com>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Link: https://lore.kernel.org/r/20220201065254.680532-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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sk_gso_max_size is set based on the dst dev. Both users of it
adjust the value by the same offset - (MAX_TCP_HEADER + 1). Rather
than compute the same adjusted value on each call do the adjustment
once when set.
Signed-off-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20220125024511.27480-1-dsahern@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Without it, splice users can hit the warning
added in commit 79074a72d335 ("net: Flush deferred skb free on socket destroy")
Fixes: f35f821935d8 ("tcp: defer skb freeing after socket lock is released")
Fixes: 79074a72d335 ("net: Flush deferred skb free on socket destroy")
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Gal Pressman <gal@nvidia.com>
Link: https://lore.kernel.org/r/20220120124530.925607-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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include/net/sock.h
commit 8f905c0e7354 ("inet: fully convert sk->sk_rx_dst to RCU rules")
commit 43f51df41729 ("net: move early demux fields close to sk_refcnt")
https://lore.kernel.org/all/20211222141641.0caa0ab3@canb.auug.org.au/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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syzbot reported various issues around early demux,
one being included in this changelog [1]
sk->sk_rx_dst is using RCU protection without clearly
documenting it.
And following sequences in tcp_v4_do_rcv()/tcp_v6_do_rcv()
are not following standard RCU rules.
[a] dst_release(dst);
[b] sk->sk_rx_dst = NULL;
They look wrong because a delete operation of RCU protected
pointer is supposed to clear the pointer before
the call_rcu()/synchronize_rcu() guarding actual memory freeing.
In some cases indeed, dst could be freed before [b] is done.
We could cheat by clearing sk_rx_dst before calling
dst_release(), but this seems the right time to stick
to standard RCU annotations and debugging facilities.
[1]
BUG: KASAN: use-after-free in dst_check include/net/dst.h:470 [inline]
BUG: KASAN: use-after-free in tcp_v4_early_demux+0x95b/0x960 net/ipv4/tcp_ipv4.c:1792
Read of size 2 at addr ffff88807f1cb73a by task syz-executor.5/9204
CPU: 0 PID: 9204 Comm: syz-executor.5 Not tainted 5.16.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description.constprop.0.cold+0x8d/0x320 mm/kasan/report.c:247
__kasan_report mm/kasan/report.c:433 [inline]
kasan_report.cold+0x83/0xdf mm/kasan/report.c:450
dst_check include/net/dst.h:470 [inline]
tcp_v4_early_demux+0x95b/0x960 net/ipv4/tcp_ipv4.c:1792
ip_rcv_finish_core.constprop.0+0x15de/0x1e80 net/ipv4/ip_input.c:340
ip_list_rcv_finish.constprop.0+0x1b2/0x6e0 net/ipv4/ip_input.c:583
ip_sublist_rcv net/ipv4/ip_input.c:609 [inline]
ip_list_rcv+0x34e/0x490 net/ipv4/ip_input.c:644
__netif_receive_skb_list_ptype net/core/dev.c:5508 [inline]
__netif_receive_skb_list_core+0x549/0x8e0 net/core/dev.c:5556
__netif_receive_skb_list net/core/dev.c:5608 [inline]
netif_receive_skb_list_internal+0x75e/0xd80 net/core/dev.c:5699
gro_normal_list net/core/dev.c:5853 [inline]
gro_normal_list net/core/dev.c:5849 [inline]
napi_complete_done+0x1f1/0x880 net/core/dev.c:6590
virtqueue_napi_complete drivers/net/virtio_net.c:339 [inline]
virtnet_poll+0xca2/0x11b0 drivers/net/virtio_net.c:1557
__napi_poll+0xaf/0x440 net/core/dev.c:7023
napi_poll net/core/dev.c:7090 [inline]
net_rx_action+0x801/0xb40 net/core/dev.c:7177
__do_softirq+0x29b/0x9c2 kernel/softirq.c:558
invoke_softirq kernel/softirq.c:432 [inline]
__irq_exit_rcu+0x123/0x180 kernel/softirq.c:637
irq_exit_rcu+0x5/0x20 kernel/softirq.c:649
common_interrupt+0x52/0xc0 arch/x86/kernel/irq.c:240
asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:629
RIP: 0033:0x7f5e972bfd57
Code: 39 d1 73 14 0f 1f 80 00 00 00 00 48 8b 50 f8 48 83 e8 08 48 39 ca 77 f3 48 39 c3 73 3e 48 89 13 48 8b 50 f8 48 89 38 49 8b 0e <48> 8b 3e 48 83 c3 08 48 83 c6 08 eb bc 48 39 d1 72 9e 48 39 d0 73
RSP: 002b:00007fff8a413210 EFLAGS: 00000283
RAX: 00007f5e97108990 RBX: 00007f5e97108338 RCX: ffffffff81d3aa45
RDX: ffffffff81d3aa45 RSI: 00007f5e97108340 RDI: ffffffff81d3aa45
RBP: 00007f5e97107eb8 R08: 00007f5e97108d88 R09: 0000000093c2e8d9
R10: 0000000000000000 R11: 0000000000000000 R12: 00007f5e97107eb0
R13: 00007f5e97108338 R14: 00007f5e97107ea8 R15: 0000000000000019
</TASK>
Allocated by task 13:
kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
__kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:467
kasan_slab_alloc include/linux/kasan.h:259 [inline]
slab_post_alloc_hook mm/slab.h:519 [inline]
slab_alloc_node mm/slub.c:3234 [inline]
slab_alloc mm/slub.c:3242 [inline]
kmem_cache_alloc+0x202/0x3a0 mm/slub.c:3247
dst_alloc+0x146/0x1f0 net/core/dst.c:92
rt_dst_alloc+0x73/0x430 net/ipv4/route.c:1613
ip_route_input_slow+0x1817/0x3a20 net/ipv4/route.c:2340
ip_route_input_rcu net/ipv4/route.c:2470 [inline]
ip_route_input_noref+0x116/0x2a0 net/ipv4/route.c:2415
ip_rcv_finish_core.constprop.0+0x288/0x1e80 net/ipv4/ip_input.c:354
ip_list_rcv_finish.constprop.0+0x1b2/0x6e0 net/ipv4/ip_input.c:583
ip_sublist_rcv net/ipv4/ip_input.c:609 [inline]
ip_list_rcv+0x34e/0x490 net/ipv4/ip_input.c:644
__netif_receive_skb_list_ptype net/core/dev.c:5508 [inline]
__netif_receive_skb_list_core+0x549/0x8e0 net/core/dev.c:5556
__netif_receive_skb_list net/core/dev.c:5608 [inline]
netif_receive_skb_list_internal+0x75e/0xd80 net/core/dev.c:5699
gro_normal_list net/core/dev.c:5853 [inline]
gro_normal_list net/core/dev.c:5849 [inline]
napi_complete_done+0x1f1/0x880 net/core/dev.c:6590
virtqueue_napi_complete drivers/net/virtio_net.c:339 [inline]
virtnet_poll+0xca2/0x11b0 drivers/net/virtio_net.c:1557
__napi_poll+0xaf/0x440 net/core/dev.c:7023
napi_poll net/core/dev.c:7090 [inline]
net_rx_action+0x801/0xb40 net/core/dev.c:7177
__do_softirq+0x29b/0x9c2 kernel/softirq.c:558
Freed by task 13:
kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
kasan_set_track+0x21/0x30 mm/kasan/common.c:46
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
____kasan_slab_free mm/kasan/common.c:366 [inline]
____kasan_slab_free mm/kasan/common.c:328 [inline]
__kasan_slab_free+0xff/0x130 mm/kasan/common.c:374
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:1723 [inline]
slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1749
slab_free mm/slub.c:3513 [inline]
kmem_cache_free+0xbd/0x5d0 mm/slub.c:3530
dst_destroy+0x2d6/0x3f0 net/core/dst.c:127
rcu_do_batch kernel/rcu/tree.c:2506 [inline]
rcu_core+0x7ab/0x1470 kernel/rcu/tree.c:2741
__do_softirq+0x29b/0x9c2 kernel/softirq.c:558
Last potentially related work creation:
kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
__kasan_record_aux_stack+0xf5/0x120 mm/kasan/generic.c:348
__call_rcu kernel/rcu/tree.c:2985 [inline]
call_rcu+0xb1/0x740 kernel/rcu/tree.c:3065
dst_release net/core/dst.c:177 [inline]
dst_release+0x79/0xe0 net/core/dst.c:167
tcp_v4_do_rcv+0x612/0x8d0 net/ipv4/tcp_ipv4.c:1712
sk_backlog_rcv include/net/sock.h:1030 [inline]
__release_sock+0x134/0x3b0 net/core/sock.c:2768
release_sock+0x54/0x1b0 net/core/sock.c:3300
tcp_sendmsg+0x36/0x40 net/ipv4/tcp.c:1441
inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819
sock_sendmsg_nosec net/socket.c:704 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:724
sock_write_iter+0x289/0x3c0 net/socket.c:1057
call_write_iter include/linux/fs.h:2162 [inline]
new_sync_write+0x429/0x660 fs/read_write.c:503
vfs_write+0x7cd/0xae0 fs/read_write.c:590
ksys_write+0x1ee/0x250 fs/read_write.c:643
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
The buggy address belongs to the object at ffff88807f1cb700
which belongs to the cache ip_dst_cache of size 176
The buggy address is located 58 bytes inside of
176-byte region [ffff88807f1cb700, ffff88807f1cb7b0)
The buggy address belongs to the page:
page:ffffea0001fc72c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7f1cb
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 dead000000000100 dead000000000122 ffff8881413bb780
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 5, ts 108466983062, free_ts 108048976062
prep_new_page mm/page_alloc.c:2418 [inline]
get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4149
__alloc_pages+0x1b2/0x500 mm/page_alloc.c:5369
alloc_pages+0x1a7/0x300 mm/mempolicy.c:2191
alloc_slab_page mm/slub.c:1793 [inline]
allocate_slab mm/slub.c:1930 [inline]
new_slab+0x32d/0x4a0 mm/slub.c:1993
___slab_alloc+0x918/0xfe0 mm/slub.c:3022
__slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3109
slab_alloc_node mm/slub.c:3200 [inline]
slab_alloc mm/slub.c:3242 [inline]
kmem_cache_alloc+0x35c/0x3a0 mm/slub.c:3247
dst_alloc+0x146/0x1f0 net/core/dst.c:92
rt_dst_alloc+0x73/0x430 net/ipv4/route.c:1613
__mkroute_output net/ipv4/route.c:2564 [inline]
ip_route_output_key_hash_rcu+0x921/0x2d00 net/ipv4/route.c:2791
ip_route_output_key_hash+0x18b/0x300 net/ipv4/route.c:2619
__ip_route_output_key include/net/route.h:126 [inline]
ip_route_output_flow+0x23/0x150 net/ipv4/route.c:2850
ip_route_output_key include/net/route.h:142 [inline]
geneve_get_v4_rt+0x3a6/0x830 drivers/net/geneve.c:809
geneve_xmit_skb drivers/net/geneve.c:899 [inline]
geneve_xmit+0xc4a/0x3540 drivers/net/geneve.c:1082
__netdev_start_xmit include/linux/netdevice.h:4994 [inline]
netdev_start_xmit include/linux/netdevice.h:5008 [inline]
xmit_one net/core/dev.c:3590 [inline]
dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3606
__dev_queue_xmit+0x299a/0x3650 net/core/dev.c:4229
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1338 [inline]
free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1389
free_unref_page_prepare mm/page_alloc.c:3309 [inline]
free_unref_page+0x19/0x690 mm/page_alloc.c:3388
qlink_free mm/kasan/quarantine.c:146 [inline]
qlist_free_all+0x5a/0xc0 mm/kasan/quarantine.c:165
kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272
__kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:444
kasan_slab_alloc include/linux/kasan.h:259 [inline]
slab_post_alloc_hook mm/slab.h:519 [inline]
slab_alloc_node mm/slub.c:3234 [inline]
kmem_cache_alloc_node+0x255/0x3f0 mm/slub.c:3270
__alloc_skb+0x215/0x340 net/core/skbuff.c:414
alloc_skb include/linux/skbuff.h:1126 [inline]
alloc_skb_with_frags+0x93/0x620 net/core/skbuff.c:6078
sock_alloc_send_pskb+0x783/0x910 net/core/sock.c:2575
mld_newpack+0x1df/0x770 net/ipv6/mcast.c:1754
add_grhead+0x265/0x330 net/ipv6/mcast.c:1857
add_grec+0x1053/0x14e0 net/ipv6/mcast.c:1995
mld_send_initial_cr.part.0+0xf6/0x230 net/ipv6/mcast.c:2242
mld_send_initial_cr net/ipv6/mcast.c:1232 [inline]
mld_dad_work+0x1d3/0x690 net/ipv6/mcast.c:2268
process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
Memory state around the buggy address:
ffff88807f1cb600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88807f1cb680: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
>ffff88807f1cb700: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88807f1cb780: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
ffff88807f1cb800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
Fixes: 41063e9dd119 ("ipv4: Early TCP socket demux.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20211220143330.680945-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Expose __tcp_sock_set_cork() and __tcp_sock_set_nodelay() for use in
MPTCP setsockopt code -- namely for syncing MPTCP socket options with
subflows inside sync_socket_options() while already holding the subflow
socket lock.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Maxim Galaganov <max@internet.ru>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Under pressure, tcp recvmsg() has logic to process the socket backlog,
but calls tcp_cleanup_rbuf() right before.
Avoiding sending ACK right before processing new segments makes
a lot of sense, as this decrease the number of ACK packets,
with no impact on effective ACK clocking.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Testing timeo before sk_err/sk_state/sk_shutdown makes more sense.
Modern applications use non-blocking IO, while a socket is terminated
only once during its life time.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
tcp recvmsg() (or rx zerocopy) spends a fair amount of time
freeing skbs after their payload has been consumed.
A typical ~64KB GRO packet has to release ~45 page
references, eventually going to page allocator
for each of them.
Currently, this freeing is performed while socket lock
is held, meaning that there is a high chance that
BH handler has to queue incoming packets to tcp socket backlog.
This can cause additional latencies, because the user
thread has to process the backlog at release_sock() time,
and while doing so, additional frames can be added
by BH handler.
This patch adds logic to defer these frees after socket
lock is released, or directly from BH handler if possible.
Being able to free these skbs from BH handler helps a lot,
because this avoids the usual alloc/free assymetry,
when BH handler and user thread do not run on same cpu or
NUMA node.
One cpu can now be fully utilized for the kernel->user copy,
and another cpu is handling BH processing and skb/page
allocs/frees (assuming RFS is not forcing use of a single CPU)
Tested:
100Gbit NIC
Max throughput for one TCP_STREAM flow, over 10 runs
MTU : 1500
Before: 55 Gbit
After: 66 Gbit
MTU : 4096+(headers)
Before: 82 Gbit
After: 95 Gbit
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
TCP uses sk_eat_skb() when skbs can be removed from receive queue.
However, the call to skb_orphan() from __kfree_skb() incurs
an indirect call so sock_rfee(), which is more expensive than
a direct call, especially for CONFIG_RETPOLINE=y.
Add tcp_eat_recv_skb() function to make the call before
__kfree_skb().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Use some unlikely() hints in the fast path.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
tcp_poll() and tcp_ioctl() are reading tp->urg_data without socket lock
owned.
Also, it is faster to first check tp->urg_data in tcp_poll(),
then tp->urg_seq == tp->copied_seq, because tp->urg_seq is
located in a different/cold cache line.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
tcp_segs_in() can be called from BH, while socket spinlock
is held but socket owned by user, eventually reading these
fields from tcp_get_info()
Found by code inspection, no need to backport this patch
to older kernels.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
When reading large chunks of data, incoming packets might
be added to the backlog from BH.
tcp recvmsg() detects the backlog queue is not empty, and uses
a release_sock()/lock_sock() pair to process this backlog.
We now have __sk_flush_backlog() to perform this
a bit faster.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
tcp_memory_allocated and tcp_sockets_allocated often share
a common cache line, source of false sharing.
Also take care of udp_memory_allocated and mptcp_sockets_allocated.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
We were only using one bit, and we can replace it by sk_is_tcp()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
TCP Receive zerocopy iterates through the SKB queue via
tcp_recv_skb(), acquiring a pointer to an SKB and an offset within
that SKB to read from. From there, it iterates the SKB frags array to
determine which offset to start remapping pages from.
However, this is built on the assumption that the offset read so far
within the SKB is smaller than the SKB length. If this assumption is
violated, we can attempt to read an invalid frags array element, which
would cause a fault.
tcp_recv_skb() can cause such an SKB to be returned when the TCP FIN
flag is set. Therefore, we must guard against this occurrence inside
skb_advance_frag().
One way that we can reproduce this error follows:
1) In a receiver program, call getsockopt(TCP_ZEROCOPY_RECEIVE) with:
char some_array[32 * 1024];
struct tcp_zerocopy_receive zc = {
.copybuf_address = (__u64) &some_array[0],
.copybuf_len = 32 * 1024,
};
2) In a sender program, after a TCP handshake, send the following
sequence of packets:
i) Seq = [X, X+4000]
ii) Seq = [X+4000, X+5000]
iii) Seq = [X+4000, X+5000], Flags = FIN | URG, urgptr=1000
(This can happen without URG, if we have a signal pending, but URG is
a convenient way to reproduce the behaviour).
In this case, the following event sequence will occur on the receiver:
tcp_zerocopy_receive():
-> receive_fallback_to_copy() // copybuf_len >= inq
-> tcp_recvmsg_locked() // reads 5000 bytes, then breaks due to URG
-> tcp_recv_skb() // yields skb with skb->len == offset
-> tcp_zerocopy_set_hint_for_skb()
-> skb_advance_to_frag() // will returns a frags ptr. >= nr_frags
-> find_next_mappable_frag() // will dereference this bad frags ptr.
With this patch, skb_advance_to_frag() will no longer return an
invalid frags pointer, and will return NULL instead, fixing the issue.
Signed-off-by: Arjun Roy <arjunroy@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 05255b823a61 ("tcp: add TCP_ZEROCOPY_RECEIVE support for zerocopy receive")
Link: https://lore.kernel.org/r/20211111235215.2605384-1-arjunroy.kdev@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
"Including fixes from bpf, can and netfilter.
Current release - regressions:
- bpf: do not reject when the stack read size is different from the
tracked scalar size
- net: fix premature exit from NAPI state polling in napi_disable()
- riscv, bpf: fix RV32 broken build, and silence RV64 warning
Current release - new code bugs:
- net: fix possible NULL deref in sock_reserve_memory
- amt: fix error return code in amt_init(); fix stopping the
workqueue
- ax88796c: use the correct ioctl callback
Previous releases - always broken:
- bpf: stop caching subprog index in the bpf_pseudo_func insn
- security: fixups for the security hooks in sctp
- nfc: add necessary privilege flags in netlink layer, limit
operations to admin only
- vsock: prevent unnecessary refcnt inc for non-blocking connect
- net/smc: fix sk_refcnt underflow on link down and fallback
- nfnetlink_queue: fix OOB when mac header was cleared
- can: j1939: ignore invalid messages per standard
- bpf, sockmap:
- fix race in ingress receive verdict with redirect to self
- fix incorrect sk_skb data_end access when src_reg = dst_reg
- strparser, and tls are reusing qdisc_skb_cb and colliding
- ethtool: fix ethtool msg len calculation for pause stats
- vlan: fix a UAF in vlan_dev_real_dev() when ref-holder tries to
access an unregistering real_dev
- udp6: make encap_rcv() bump the v6 not v4 stats
- drv: prestera: add explicit padding to fix m68k build
- drv: felix: fix broken VLAN-tagged PTP under VLAN-aware bridge
- drv: mvpp2: fix wrong SerDes reconfiguration order
Misc & small latecomers:
- ipvs: auto-load ipvs on genl access
- mctp: sanity check the struct sockaddr_mctp padding fields
- libfs: support RENAME_EXCHANGE in simple_rename()
- avoid double accounting for pure zerocopy skbs"
* tag 'net-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (123 commits)
selftests/net: udpgso_bench_rx: fix port argument
net: wwan: iosm: fix compilation warning
cxgb4: fix eeprom len when diagnostics not implemented
net: fix premature exit from NAPI state polling in napi_disable()
net/smc: fix sk_refcnt underflow on linkdown and fallback
net/mlx5: Lag, fix a potential Oops with mlx5_lag_create_definer()
gve: fix unmatched u64_stats_update_end()
net: ethernet: lantiq_etop: Fix compilation error
selftests: forwarding: Fix packet matching in mirroring selftests
vsock: prevent unnecessary refcnt inc for nonblocking connect
net: marvell: mvpp2: Fix wrong SerDes reconfiguration order
net: ethernet: ti: cpsw_ale: Fix access to un-initialized memory
net: stmmac: allow a tc-taprio base-time of zero
selftests: net: test_vxlan_under_vrf: fix HV connectivity test
net: hns3: allow configure ETS bandwidth of all TCs
net: hns3: remove check VF uc mac exist when set by PF
net: hns3: fix some mac statistics is always 0 in device version V2
net: hns3: fix kernel crash when unload VF while it is being reset
net: hns3: sync rx ring head in echo common pull
net: hns3: fix pfc packet number incorrect after querying pfc parameters
...
|
|
Merge misc updates from Andrew Morton:
"257 patches.
Subsystems affected by this patch series: scripts, ocfs2, vfs, and
mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache,
gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc,
pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools,
memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm,
vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram,
cleanups, kfence, and damon)"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (257 commits)
mm/damon: remove return value from before_terminate callback
mm/damon: fix a few spelling mistakes in comments and a pr_debug message
mm/damon: simplify stop mechanism
Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions
Docs/admin-guide/mm/damon/start: simplify the content
Docs/admin-guide/mm/damon/start: fix a wrong link
Docs/admin-guide/mm/damon/start: fix wrong example commands
mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on
mm/damon: remove unnecessary variable initialization
Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM
mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM)
selftests/damon: support watermarks
mm/damon/dbgfs: support watermarks
mm/damon/schemes: activate schemes based on a watermarks mechanism
tools/selftests/damon: update for regions prioritization of schemes
mm/damon/dbgfs: support prioritization weights
mm/damon/vaddr,paddr: support pageout prioritization
mm/damon/schemes: prioritize regions within the quotas
mm/damon/selftests: support schemes quotas
mm/damon/dbgfs: support quotas of schemes
...
|
|
nr_free_buffer_pages could be exposed through mm.h instead of swap.h.
The advantage of this change is that it can reduce the obsolete
includes. For example, net/ipv4/tcp.c wouldn't need swap.h any more
since it has already included mm.h. Similarly, after checking all the
other files, it comes that tcp.c, udp.c meter.c ,... follow the same
rule, so these files can have swap.h removed too.
Moreover, after preprocessing all the files that use
nr_free_buffer_pages, it turns out that those files have already
included mm.h.Thus, we can move nr_free_buffer_pages from swap.h to mm.h
safely. This change will not affect the compilation of other files.
Link: https://lkml.kernel.org/r/20210912133640.1624-1-liumh1@shanghaitech.edu.cn
Signed-off-by: Mianhan Liu <liumh1@shanghaitech.edu.cn>
Cc: Jakub Kicinski <kuba@kernel.org>
CC: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "David S . Miller" <davem@davemloft.net>
Cc: Simon Horman <horms@verge.net.au>
Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Track skbs containing only zerocopy data and avoid charging them to
kernel memory to correctly account the memory utilization for
msg_zerocopy. All of the data in such skbs is held in user pages which
are already accounted to user. Before this change, they are charged
again in kernel in __zerocopy_sg_from_iter. The charging in kernel is
excessive because data is not being copied into skb frags. This
excessive charging can lead to kernel going into memory pressure
state which impacts all sockets in the system adversely. Mark pure
zerocopy skbs with a SKBFL_PURE_ZEROCOPY flag and remove
charge/uncharge for data in such skbs.
Initially, an skb is marked pure zerocopy when it is empty and in
zerocopy path. skb can then change from a pure zerocopy skb to mixed
data skb (zerocopy and copy data) if it is at tail of write queue and
there is room available in it and non-zerocopy data is being sent in
the next sendmsg call. At this time sk_mem_charge is done for the pure
zerocopied data and the pure zerocopy flag is unmarked. We found that
this happens very rarely on workloads that pass MSG_ZEROCOPY.
A pure zerocopy skb can later be coalesced into normal skb if they are
next to each other in queue but this patch prevents coalescing from
happening. This avoids complexity of charging when skb downgrades from
pure zerocopy to mixed. This is also rare.
In sk_wmem_free_skb, if it is a pure zerocopy skb, an sk_mem_uncharge
for SKB_TRUESIZE(skb_end_offset(skb)) is done for sk_mem_charge in
tcp_skb_entail for an skb without data.
Testing with the msg_zerocopy.c benchmark between two hosts(100G nics)
with zerocopy showed that before this patch the 'sock' variable in
memory.stat for cgroup2 that tracks sum of sk_forward_alloc,
sk_rmem_alloc and sk_wmem_queued is around 1822720 and with this
change it is 0. This is due to no charge to sk_forward_alloc for
zerocopy data and shows memory utilization for kernel is lowered.
With this commit we don't see the warning we saw in previous commit
which resulted in commit 84882cf72cd774cf16fd338bdbf00f69ac9f9194.
Signed-off-by: Talal Ahmad <talalahmad@google.com>
Acked-by: Arjun Roy <arjunroy@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
This reverts commit f1a456f8f3fc5828d8abcad941860380ae147b1d.
WARNING: CPU: 1 PID: 6819 at net/core/skbuff.c:5429 skb_try_coalesce+0x78b/0x7e0
CPU: 1 PID: 6819 Comm: xxxxxxx Kdump: loaded Tainted: G S 5.15.0-04194-gd852503f7711 #16
RIP: 0010:skb_try_coalesce+0x78b/0x7e0
Code: e8 2a bf 41 ff 44 8b b3 bc 00 00 00 48 8b 7c 24 30 e8 19 c0 41 ff 44 89 f0 48 03 83 c0 00 00 00 48 89 44 24 40 e9 47 fb ff ff <0f> 0b e9 ca fc ff ff 4c 8d 70 ff 48 83 c0 07 48 89 44 24 38 e9 61
RSP: 0018:ffff88881f449688 EFLAGS: 00010282
RAX: 00000000fffffe96 RBX: ffff8881566e4460 RCX: ffffffff82079f7e
RDX: 0000000000000003 RSI: dffffc0000000000 RDI: ffff8881566e47b0
RBP: ffff8881566e46e0 R08: ffffed102619235d R09: ffffed102619235d
R10: ffff888130c91ae3 R11: ffffed102619235c R12: ffff88881f4498a0
R13: 0000000000000056 R14: 0000000000000009 R15: ffff888130c91ac0
FS: 00007fec2cbb9700(0000) GS:ffff88881f440000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fec1b060d80 CR3: 00000003acf94005 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
tcp_try_coalesce+0xeb/0x290
? tcp_parse_options+0x610/0x610
? mark_held_locks+0x79/0xa0
tcp_queue_rcv+0x69/0x2f0
tcp_rcv_established+0xa49/0xd40
? tcp_data_queue+0x18a0/0x18a0
tcp_v6_do_rcv+0x1c9/0x880
? rt6_mtu_change_route+0x100/0x100
tcp_v6_rcv+0x1624/0x1830
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Track skbs with only zerocopy data and avoid charging them to kernel
memory to correctly account the memory utilization for msg_zerocopy.
All of the data in such skbs is held in user pages which are already
accounted to user. Before this change, they are charged again in
kernel in __zerocopy_sg_from_iter. The charging in kernel is
excessive because data is not being copied into skb frags. This
excessive charging can lead to kernel going into memory pressure
state which impacts all sockets in the system adversely. Mark pure
zerocopy skbs with a SKBFL_PURE_ZEROCOPY flag and remove
charge/uncharge for data in such skbs.
Initially, an skb is marked pure zerocopy when it is empty and in
zerocopy path. skb can then change from a pure zerocopy skb to mixed
data skb (zerocopy and copy data) if it is at tail of write queue and
there is room available in it and non-zerocopy data is being sent in
the next sendmsg call. At this time sk_mem_charge is done for the pure
zerocopied data and the pure zerocopy flag is unmarked. We found that
this happens very rarely on workloads that pass MSG_ZEROCOPY.
A pure zerocopy skb can later be coalesced into normal skb if they are
next to each other in queue but this patch prevents coalescing from
happening. This avoids complexity of charging when skb downgrades from
pure zerocopy to mixed. This is also rare.
In sk_wmem_free_skb, if it is a pure zerocopy skb, an sk_mem_uncharge
for SKB_TRUESIZE(MAX_TCP_HEADER) is done for sk_mem_charge in
tcp_skb_entail for an skb without data.
Testing with the msg_zerocopy.c benchmark between two hosts(100G nics)
with zerocopy showed that before this patch the 'sock' variable in
memory.stat for cgroup2 that tracks sum of sk_forward_alloc,
sk_rmem_alloc and sk_wmem_queued is around 1822720 and with this
change it is 0. This is due to no charge to sk_forward_alloc for
zerocopy data and shows memory utilization for kernel is lowered.
Signed-off-by: Talal Ahmad <talalahmad@google.com>
Acked-by: Arjun Roy <arjunroy@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
sk_wmem_free_skb() is only used by TCP.
Rename it to make this clear, and move its declaration to
include/net/tcp.h
Signed-off-by: Talal Ahmad <talalahmad@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Arjun Roy <arjunroy@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
include/net/sock.h
7b50ecfcc6cd ("net: Rename ->stream_memory_read to ->sock_is_readable")
4c1e34c0dbff ("vsock: Enable y2038 safe timeval for timeout")
drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c
0daa55d033b0 ("octeontx2-af: cn10k: debugfs for dumping LMTST map table")
e77bcdd1f639 ("octeontx2-af: Display all enabled PF VF rsrc_alloc entries.")
Adjacent code addition in both cases, keep both.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Freshly allocated skbs have zero in skb->cb[] already.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Freshly allocated skbs have their csum field cleared already.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Setting skb->ip_summed to CHECKSUM_PARTIAL can be centralized
in tcp_stream_alloc_skb() and __mptcp_do_alloc_tx_skb()
instead of being done multiple times.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
TCP/MPTCP sendmsg() no longer puts payload in skb->head,
we can remove not needed code.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
All tcp_remove_empty_skb() callers now use tcp_write_queue_tail()
for the skb argument, we can therefore factorize code.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
TCP sendmsg() no longer puts payload in skb head, we can remove
dead code.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
The proto ops ->stream_memory_read() is currently only used
by TCP to check whether psock queue is empty or not. We need
to rename it before reusing it for non-TCP protocols, and
adjust the exsiting users accordingly.
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211008203306.37525-2-xiyou.wangcong@gmail.com
|
|
Aligning @size argument to 4 bytes is not needed.
The header alignment has nothing to do with @size.
It really depends on skb->head alignment and MAX_TCP_HEADER.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Both IPv4 and IPv6 uses same reserve, no need risking
cache line misses to fetch its value.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
sk_stream_alloc_skb() is only used by TCP.
Rename it to make this clear, and move its declaration
to include/net/tcp.h
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
v1: Implement a more general statement as recommended by Eric Dumazet. The
sequence number will be advanced, so this check will fix the FIN case and
other cases.
A customer reported sockets stuck in the CLOSING state. A Vmcore revealed that
the write_queue was not empty as determined by tcp_write_queue_empty() but the
sk_buff containing the FIN flag had been freed and the socket was zombied in
that state. Corresponding pcaps show no FIN from the Linux kernel on the wire.
Some instrumentation was added to the kernel and it was found that there is a
timing window where tcp_sendmsg() can run after tcp_send_fin().
tcp_sendmsg() will hit an error, for example:
1269 ▹ if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))↩
1270 ▹ ▹ goto do_error;↩
tcp_remove_empty_skb() will then free the FIN sk_buff as "skb->len == 0". The
TCP socket is now wedged in the FIN-WAIT-1 state because the FIN is never sent.
If the other side sends a FIN packet the socket will transition to CLOSING and
remain that way until the system is rebooted.
Fix this by checking for the FIN flag in the sk_buff and don't free it if that
is the case. Testing confirmed that fixed the issue.
Fixes: fdfc5c8594c2 ("tcp: remove empty skb from write queue in error cases")
Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com>
Reported-by: Monir Zouaoui <Monir.Zouaoui@mail.schwarz>
Reported-by: Simon Stier <simon.stier@mail.schwarz>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Use of percpu_counter structure to track count of orphaned
sockets is causing problems on modern hosts with 256 cpus
or more.
Stefan Bach reported a serious spinlock contention in real workloads,
that I was able to reproduce with a netfilter rule dropping
incoming FIN packets.
53.56% server [kernel.kallsyms] [k] queued_spin_lock_slowpath
|
---queued_spin_lock_slowpath
|
--53.51%--_raw_spin_lock_irqsave
|
--53.51%--__percpu_counter_sum
tcp_check_oom
|
|--39.03%--__tcp_close
| tcp_close
| inet_release
| inet6_release
| sock_close
| __fput
| ____fput
| task_work_run
| exit_to_usermode_loop
| do_syscall_64
| entry_SYSCALL_64_after_hwframe
| __GI___libc_close
|
--14.48%--tcp_out_of_resources
tcp_write_timeout
tcp_retransmit_timer
tcp_write_timer_handler
tcp_write_timer
call_timer_fn
expire_timers
__run_timers
run_timer_softirq
__softirqentry_text_start
As explained in commit cf86a086a180 ("net/dst: use a smaller percpu_counter
batch for dst entries accounting"), default batch size is too big
for the default value of tcp_max_orphans (262144).
But even if we reduce batch sizes, there would still be cases
where the estimated count of orphans is beyond the limit,
and where tcp_too_many_orphans() has to call the expensive
percpu_counter_sum_positive().
One solution is to use plain per-cpu counters, and have
a timer to periodically refresh this cache.
Updating this cache every 100ms seems about right, tcp pressure
state is not radically changing over shorter periods.
percpu_counter was nice 15 years ago while hosts had less
than 16 cpus, not anymore by current standards.
v2: Fix the build issue for CONFIG_CRYPTO_DEV_CHELSIO_TLS=m,
reported by kernel test robot <lkp@intel.com>
Remove unused socket argument from tcp_too_many_orphans()
Fixes: dd24c00191d5 ("net: Use a percpu_counter for orphan_count")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Stefan Bach <sfb@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
This reverts the following patches :
- commit 2e05fcae83c4 ("tcp: fix compile error if !CONFIG_SYSCTL")
- commit 4f661542a402 ("tcp: fix zerocopy and notsent_lowat issues")
- commit 472c2e07eef0 ("tcp: add one skb cache for tx")
- commit 8b27dae5a2e8 ("tcp: add one skb cache for rx")
Having a cache of one skb (in each direction) per TCP socket is fragile,
since it can cause a significant increase of memory needs,
and not good enough for high speed flows anyway where more than one skb
is needed.
We want instead to add a generic infrastructure, with more flexible
per-cpu caches, for alien NUMA nodes.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
After the previous patch the mentioned helper is
used only inside its compilation unit: let's make
it static.
RFC -> v1:
- preserve the tcp_build_frag() helper (Eric)
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
the tcp_skb_entail() helper is actually skb_entail(), renamed
to provide proper scope.
The two helper will be used by the next patch.
RFC -> v1:
- rename skb_entail to tcp_skb_entail (Eric)
Acked-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
