1. 08 Apr, 2018 1 commit
    • Eric Dumazet's avatar
      soreuseport: initialise timewait reuseport field · 3099a529
      Eric Dumazet authored
      syzbot reported an uninit-value in inet_csk_bind_conflict() [1]
      
      It turns out we never propagated sk->sk_reuseport into timewait socket.
      
      [1]
      BUG: KMSAN: uninit-value in inet_csk_bind_conflict+0x5f9/0x990 net/ipv4/inet_connection_sock.c:151
      CPU: 1 PID: 3589 Comm: syzkaller008242 Not tainted 4.16.0+ #82
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
      Call Trace:
       __dump_stack lib/dump_stack.c:17 [inline]
       dump_stack+0x185/0x1d0 lib/dump_stack.c:53
       kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
       __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676
       inet_csk_bind_conflict+0x5f9/0x990 net/ipv4/inet_connection_sock.c:151
       inet_csk_get_port+0x1d28/0x1e40 net/ipv4/inet_connection_sock.c:320
       inet6_bind+0x121c/0x1820 net/ipv6/af_inet6.c:399
       SYSC_bind+0x3f2/0x4b0 net/socket.c:1474
       SyS_bind+0x54/0x80 net/socket.c:1460
       do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
       entry_SYSCALL_64_after_hwframe+0x3d/0xa2
      RIP: 0033:0x4416e9
      RSP: 002b:00007ffce6d15c88 EFLAGS: 00000217 ORIG_RAX: 0000000000000031
      RAX: ffffffffffffffda RBX: 0100000000000000 RCX: 00000000004416e9
      RDX: 000000000000001c RSI: 0000000020402000 RDI: 0000000000000004
      RBP: 0000000000000000 R08: 00000000e6d15e08 R09: 00000000e6d15e08
      R10: 0000000000000004 R11: 0000000000000217 R12: 0000000000009478
      R13: 00000000006cd448 R14: 0000000000000000 R15: 0000000000000000
      
      Uninit was stored to memory at:
       kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
       kmsan_save_stack mm/kmsan/kmsan.c:293 [inline]
       kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684
       __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:521
       tcp_time_wait+0xf17/0xf50 net/ipv4/tcp_minisocks.c:283
       tcp_rcv_state_process+0xebe/0x6490 net/ipv4/tcp_input.c:6003
       tcp_v6_do_rcv+0x11dd/0x1d90 net/ipv6/tcp_ipv6.c:1331
       sk_backlog_rcv include/net/sock.h:908 [inline]
       __release_sock+0x2d6/0x680 net/core/sock.c:2271
       release_sock+0x97/0x2a0 net/core/sock.c:2786
       tcp_close+0x277/0x18f0 net/ipv4/tcp.c:2269
       inet_release+0x240/0x2a0 net/ipv4/af_inet.c:427
       inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:435
       sock_release net/socket.c:595 [inline]
       sock_close+0xe0/0x300 net/socket.c:1149
       __fput+0x49e/0xa10 fs/file_table.c:209
       ____fput+0x37/0x40 fs/file_table.c:243
       task_work_run+0x243/0x2c0 kernel/task_work.c:113
       exit_task_work include/linux/task_work.h:22 [inline]
       do_exit+0x10e1/0x38d0 kernel/exit.c:867
       do_group_exit+0x1a0/0x360 kernel/exit.c:970
       SYSC_exit_group+0x21/0x30 kernel/exit.c:981
       SyS_exit_group+0x25/0x30 kernel/exit.c:979
       do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
       entry_SYSCALL_64_after_hwframe+0x3d/0xa2
      Uninit was stored to memory at:
       kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
       kmsan_save_stack mm/kmsan/kmsan.c:293 [inline]
       kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684
       __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:521
       inet_twsk_alloc+0xaef/0xc00 net/ipv4/inet_timewait_sock.c:182
       tcp_time_wait+0xd9/0xf50 net/ipv4/tcp_minisocks.c:258
       tcp_rcv_state_process+0xebe/0x6490 net/ipv4/tcp_input.c:6003
       tcp_v6_do_rcv+0x11dd/0x1d90 net/ipv6/tcp_ipv6.c:1331
       sk_backlog_rcv include/net/sock.h:908 [inline]
       __release_sock+0x2d6/0x680 net/core/sock.c:2271
       release_sock+0x97/0x2a0 net/core/sock.c:2786
       tcp_close+0x277/0x18f0 net/ipv4/tcp.c:2269
       inet_release+0x240/0x2a0 net/ipv4/af_inet.c:427
       inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:435
       sock_release net/socket.c:595 [inline]
       sock_close+0xe0/0x300 net/socket.c:1149
       __fput+0x49e/0xa10 fs/file_table.c:209
       ____fput+0x37/0x40 fs/file_table.c:243
       task_work_run+0x243/0x2c0 kernel/task_work.c:113
       exit_task_work include/linux/task_work.h:22 [inline]
       do_exit+0x10e1/0x38d0 kernel/exit.c:867
       do_group_exit+0x1a0/0x360 kernel/exit.c:970
       SYSC_exit_group+0x21/0x30 kernel/exit.c:981
       SyS_exit_group+0x25/0x30 kernel/exit.c:979
       do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
       entry_SYSCALL_64_after_hwframe+0x3d/0xa2
      Uninit was created at:
       kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
       kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188
       kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314
       kmem_cache_alloc+0xaab/0xb90 mm/slub.c:2756
       inet_twsk_alloc+0x13b/0xc00 net/ipv4/inet_timewait_sock.c:163
       tcp_time_wait+0xd9/0xf50 net/ipv4/tcp_minisocks.c:258
       tcp_rcv_state_process+0xebe/0x6490 net/ipv4/tcp_input.c:6003
       tcp_v6_do_rcv+0x11dd/0x1d90 net/ipv6/tcp_ipv6.c:1331
       sk_backlog_rcv include/net/sock.h:908 [inline]
       __release_sock+0x2d6/0x680 net/core/sock.c:2271
       release_sock+0x97/0x2a0 net/core/sock.c:2786
       tcp_close+0x277/0x18f0 net/ipv4/tcp.c:2269
       inet_release+0x240/0x2a0 net/ipv4/af_inet.c:427
       inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:435
       sock_release net/socket.c:595 [inline]
       sock_close+0xe0/0x300 net/socket.c:1149
       __fput+0x49e/0xa10 fs/file_table.c:209
       ____fput+0x37/0x40 fs/file_table.c:243
       task_work_run+0x243/0x2c0 kernel/task_work.c:113
       exit_task_work include/linux/task_work.h:22 [inline]
       do_exit+0x10e1/0x38d0 kernel/exit.c:867
       do_group_exit+0x1a0/0x360 kernel/exit.c:970
       SYSC_exit_group+0x21/0x30 kernel/exit.c:981
       SyS_exit_group+0x25/0x30 kernel/exit.c:979
       do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
       entry_SYSCALL_64_after_hwframe+0x3d/0xa2
      
      Fixes: da5e3630 ("soreuseport: TCP/IPv4 implementation")
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      3099a529
  2. 15 Jan, 2018 1 commit
  3. 13 Dec, 2017 1 commit
  4. 05 Dec, 2017 1 commit
  5. 16 Nov, 2017 1 commit
  6. 18 Oct, 2017 1 commit
  7. 01 Jul, 2017 1 commit
  8. 29 Dec, 2016 1 commit
  9. 07 Jul, 2016 1 commit
  10. 04 May, 2016 1 commit
  11. 28 Apr, 2016 1 commit
  12. 21 Sep, 2015 1 commit
    • Eric Dumazet's avatar
      tcp/dccp: fix timewait races in timer handling · ed2e9239
      Eric Dumazet authored
      When creating a timewait socket, we need to arm the timer before
      allowing other cpus to find it. The signal allowing cpus to find
      the socket is setting tw_refcnt to non zero value.
      
      As we set tw_refcnt in __inet_twsk_hashdance(), we therefore need to
      call inet_twsk_schedule() first.
      
      This also means we need to remove tw_refcnt changes from
      inet_twsk_schedule() and let the caller handle it.
      
      Note that because we use mod_timer_pinned(), we have the guarantee
      the timer wont expire before we set tw_refcnt as we run in BH context.
      
      To make things more readable I introduced inet_twsk_reschedule() helper.
      
      When rearming the timer, we can use mod_timer_pending() to make sure
      we do not rearm a canceled timer.
      
      Note: This bug can possibly trigger if packets of a flow can hit
      multiple cpus. This does not normally happen, unless flow steering
      is broken somehow. This explains this bug was spotted ~5 months after
      its introduction.
      
      A similar fix is needed for SYN_RECV sockets in reqsk_queue_hash_req(),
      but will be provided in a separate patch for proper tracking.
      
      Fixes: 789f558c ("tcp/dccp: get rid of central timewait timer")
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Reported-by: default avatarYing Cai <ycai@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      ed2e9239
  13. 09 Jul, 2015 2 commits
  14. 13 May, 2015 1 commit
  15. 13 Apr, 2015 1 commit
    • Eric Dumazet's avatar
      tcp/dccp: get rid of central timewait timer · 789f558c
      Eric Dumazet authored
      Using a timer wheel for timewait sockets was nice ~15 years ago when
      memory was expensive and machines had a single processor.
      
      This does not scale, code is ugly and source of huge latencies
      (Typically 30 ms have been seen, cpus spinning on death_lock spinlock.)
      
      We can afford to use an extra 64 bytes per timewait sock and spread
      timewait load to all cpus to have better behavior.
      
      Tested:
      
      On following test, /proc/sys/net/ipv4/tcp_tw_recycle is set to 1
      on the target (lpaa24)
      
      Before patch :
      
      lpaa23:~# ./super_netperf 200 -H lpaa24 -t TCP_CC -l 60 -- -p0,0
      419594
      
      lpaa23:~# ./super_netperf 200 -H lpaa24 -t TCP_CC -l 60 -- -p0,0
      437171
      
      While test is running, we can observe 25 or even 33 ms latencies.
      
      lpaa24:~# ping -c 1000 -i 0.02 -qn lpaa23
      ...
      1000 packets transmitted, 1000 received, 0% packet loss, time 20601ms
      rtt min/avg/max/mdev = 0.020/0.217/25.771/1.535 ms, pipe 2
      
      lpaa24:~# ping -c 1000 -i 0.02 -qn lpaa23
      ...
      1000 packets transmitted, 1000 received, 0% packet loss, time 20702ms
      rtt min/avg/max/mdev = 0.019/0.183/33.761/1.441 ms, pipe 2
      
      After patch :
      
      About 90% increase of throughput :
      
      lpaa23:~# ./super_netperf 200 -H lpaa24 -t TCP_CC -l 60 -- -p0,0
      810442
      
      lpaa23:~# ./super_netperf 200 -H lpaa24 -t TCP_CC -l 60 -- -p0,0
      800992
      
      And latencies are kept to minimal values during this load, even
      if network utilization is 90% higher :
      
      lpaa24:~# ping -c 1000 -i 0.02 -qn lpaa23
      ...
      1000 packets transmitted, 1000 received, 0% packet loss, time 19991ms
      rtt min/avg/max/mdev = 0.023/0.064/0.360/0.042 ms
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      789f558c
  16. 03 Apr, 2015 1 commit
  17. 19 Mar, 2015 1 commit
  18. 12 Mar, 2015 2 commits
    • Eric W. Biederman's avatar
      net: Kill hold_net release_net · efd7ef1c
      Eric W. Biederman authored
      hold_net and release_net were an idea that turned out to be useless.
      The code has been disabled since 2008.  Kill the code it is long past due.
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Acked-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      efd7ef1c
    • Eric Dumazet's avatar
      net: add real socket cookies · 33cf7c90
      Eric Dumazet authored
      A long standing problem in netlink socket dumps is the use
      of kernel socket addresses as cookies.
      
      1) It is a security concern.
      
      2) Sockets can be reused quite quickly, so there is
         no guarantee a cookie is used once and identify
         a flow.
      
      3) request sock, establish sock, and timewait socks
         for a given flow have different cookies.
      
      Part of our effort to bring better TCP statistics requires
      to switch to a different allocator.
      
      In this patch, I chose to use a per network namespace 64bit generator,
      and to use it only in the case a socket needs to be dumped to netlink.
      (This might be refined later if needed)
      
      Note that I tried to carry cookies from request sock, to establish sock,
      then timewait sockets.
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Cc: Eric Salo <salo@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      33cf7c90
  19. 09 Oct, 2013 1 commit
    • Eric Dumazet's avatar
      tcp/dccp: remove twchain · 05dbc7b5
      Eric Dumazet authored
      TCP listener refactoring, part 3 :
      
      Our goal is to hash SYN_RECV sockets into main ehash for fast lookup,
      and parallel SYN processing.
      
      Current inet_ehash_bucket contains two chains, one for ESTABLISH (and
      friend states) sockets, another for TIME_WAIT sockets only.
      
      As the hash table is sized to get at most one socket per bucket, it
      makes little sense to have separate twchain, as it makes the lookup
      slightly more complicated, and doubles hash table memory usage.
      
      If we make sure all socket types have the lookup keys at the same
      offsets, we can use a generic and faster lookup. It turns out TIME_WAIT
      and ESTABLISHED sockets already have common lookup fields for IPv4.
      
      [ INET_TW_MATCH() is no longer needed ]
      
      I'll provide a follow-up to factorize IPv6 lookup as well, to remove
      INET6_TW_MATCH()
      
      This way, SYN_RECV pseudo sockets will be supported the same.
      
      A new sock_gen_put() helper is added, doing either a sock_put() or
      inet_twsk_put() [ and will support SYN_RECV later ].
      
      Note this helper should only be called in real slow path, when rcu
      lookup found a socket that was moved to another identity (freed/reused
      immediately), but could eventually be used in other contexts, like
      sock_edemux()
      
      Before patch :
      
      dmesg | grep "TCP established"
      
      TCP established hash table entries: 524288 (order: 11, 8388608 bytes)
      
      After patch :
      
      TCP established hash table entries: 524288 (order: 10, 4194304 bytes)
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      05dbc7b5
  20. 03 Oct, 2013 1 commit
    • Eric Dumazet's avatar
      tcp: shrink tcp6_timewait_sock by one cache line · 96f817fe
      Eric Dumazet authored
      While working on tcp listener refactoring, I found that it
      would really make things easier if sock_common could include
      the IPv6 addresses needed in the lookups, instead of doing
      very complex games to get their values (depending on sock
      being SYN_RECV, ESTABLISHED, TIME_WAIT)
      
      For this to happen, I need to be sure that tcp6_timewait_sock
      and tcp_timewait_sock consume same number of cache lines.
      
      This is possible if we only use 32bits for tw_ttd, as we remove
      one 32bit hole in inet_timewait_sock
      
      inet_tw_time_stamp() is defined and used, even if its current
      implementation looks like tcp_time_stamp : We might need finer
      resolution for tcp_time_stamp in the future.
      
      Before patch : sizeof(struct tcp6_timewait_sock) = 0xc8
      
      After patch : sizeof(struct tcp6_timewait_sock) = 0xc0
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      96f817fe
  21. 28 Feb, 2013 1 commit
    • Sasha Levin's avatar
      hlist: drop the node parameter from iterators · b67bfe0d
      Sasha Levin authored
      I'm not sure why, but the hlist for each entry iterators were conceived
      
              list_for_each_entry(pos, head, member)
      
      The hlist ones were greedy and wanted an extra parameter:
      
              hlist_for_each_entry(tpos, pos, head, member)
      
      Why did they need an extra pos parameter? I'm not quite sure. Not only
      they don't really need it, it also prevents the iterator from looking
      exactly like the list iterator, which is unfortunate.
      
      Besides the semantic patch, there was some manual work required:
      
       - Fix up the actual hlist iterators in linux/list.h
       - Fix up the declaration of other iterators based on the hlist ones.
       - A very small amount of places were using the 'node' parameter, this
       was modified to use 'obj->member' instead.
       - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
       properly, so those had to be fixed up manually.
      
      The semantic patch which is mostly the work of Peter Senna Tschudin is here:
      
      @@
      iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;
      
      type T;
      expression a,c,d,e;
      identifier b;
      statement S;
      @@
      
      -T b;
          <+... when != b
      (
      hlist_for_each_entry(a,
      - b,
      c, d) S
      |
      hlist_for_each_entry_continue(a,
      - b,
      c) S
      |
      hlist_for_each_entry_from(a,
      - b,
      c) S
      |
      hlist_for_each_entry_rcu(a,
      - b,
      c, d) S
      |
      hlist_for_each_entry_rcu_bh(a,
      - b,
      c, d) S
      |
      hlist_for_each_entry_continue_rcu_bh(a,
      - b,
      c) S
      |
      for_each_busy_worker(a, c,
      - b,
      d) S
      |
      ax25_uid_for_each(a,
      - b,
      c) S
      |
      ax25_for_each(a,
      - b,
      c) S
      |
      inet_bind_bucket_for_each(a,
      - b,
      c) S
      |
      sctp_for_each_hentry(a,
      - b,
      c) S
      |
      sk_for_each(a,
      - b,
      c) S
      |
      sk_for_each_rcu(a,
      - b,
      c) S
      |
      sk_for_each_from
      -(a, b)
      +(a)
      S
      + sk_for_each_from(a) S
      |
      sk_for_each_safe(a,
      - b,
      c, d) S
      |
      sk_for_each_bound(a,
      - b,
      c) S
      |
      hlist_for_each_entry_safe(a,
      - b,
      c, d, e) S
      |
      hlist_for_each_entry_continue_rcu(a,
      - b,
      c) S
      |
      nr_neigh_for_each(a,
      - b,
      c) S
      |
      nr_neigh_for_each_safe(a,
      - b,
      c, d) S
      |
      nr_node_for_each(a,
      - b,
      c) S
      |
      nr_node_for_each_safe(a,
      - b,
      c, d) S
      |
      - for_each_gfn_sp(a, c, d, b) S
      + for_each_gfn_sp(a, c, d) S
      |
      - for_each_gfn_indirect_valid_sp(a, c, d, b) S
      + for_each_gfn_indirect_valid_sp(a, c, d) S
      |
      for_each_host(a,
      - b,
      c) S
      |
      for_each_host_safe(a,
      - b,
      c, d) S
      |
      for_each_mesh_entry(a,
      - b,
      c, d) S
      )
          ...+>
      
      [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
      [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
      [akpm@linux-foundation.org: checkpatch fixes]
      [akpm@linux-foundation.org: fix warnings]
      [akpm@linux-foudnation.org: redo intrusive kvm changes]
      Tested-by: Peter Senna Tschudin's avatarPeter Senna Tschudin <peter.senna@gmail.com>
      Acked-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      Cc: Wu Fengguang <fengguang.wu@intel.com>
      Cc: Marcelo Tosatti <mtosatti@redhat.com>
      Cc: Gleb Natapov <gleb@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b67bfe0d
  22. 16 May, 2012 1 commit
  23. 15 Apr, 2012 1 commit
  24. 31 Oct, 2011 1 commit
  25. 24 Oct, 2011 1 commit
    • Eric Dumazet's avatar
      ipv4: tcp: fix TOS value in ACK messages sent from TIME_WAIT · 66b13d99
      Eric Dumazet authored
      There is a long standing bug in linux tcp stack, about ACK messages sent
      on behalf of TIME_WAIT sockets.
      
      In the IP header of the ACK message, we choose to reflect TOS field of
      incoming message, and this might break some setups.
      
      Example of things that were broken :
        - Routing using TOS as a selector
        - Firewalls
        - Trafic classification / shaping
      
      We now remember in timewait structure the inet tos field and use it in
      ACK generation, and route lookup.
      
      Notes :
       - We still reflect incoming TOS in RST messages.
       - We could extend MuraliRaja Muniraju patch to report TOS value in
      netlink messages for TIME_WAIT sockets.
       - A patch is needed for IPv6
      Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      66b13d99
  26. 20 Feb, 2011 1 commit
    • Eric Dumazet's avatar
      tcp: fix inet_twsk_deschedule() · 91035f0b
      Eric Dumazet authored
      Eric W. Biederman reported a lockdep splat in inet_twsk_deschedule()
      
      This is caused by inet_twsk_purge(), run from process context,
      and commit 575f4cd5 (net: Use rcu lookups in inet_twsk_purge.)
      removed the BH disabling that was necessary.
      
      Add the BH disabling but fine grained, right before calling
      inet_twsk_deschedule(), instead of whole function.
      
      With help from Linus Torvalds and Eric W. Biederman
      Reported-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
      CC: Daniel Lezcano <daniel.lezcano@free.fr>
      CC: Pavel Emelyanov <xemul@openvz.org>
      CC: Arnaldo Carvalho de Melo <acme@redhat.com>
      CC: stable <stable@kernel.org> (# 2.6.33+)
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      91035f0b
  27. 30 Mar, 2010 1 commit
    • Tejun Heo's avatar
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo authored
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Guess-its-ok-by: default avatarChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  28. 09 Dec, 2009 2 commits
  29. 04 Dec, 2009 2 commits
    • Eric Dumazet's avatar
      tcp: fix a timewait refcnt race · 47e1c323
      Eric Dumazet authored
      After TCP RCU conversion, tw->tw_refcnt should not be set to 1 in
      inet_twsk_alloc(). It allows a RCU reader to get this timewait socket,
      while we not yet stabilized it.
      
      Only choice we have is to set tw_refcnt to 0 in inet_twsk_alloc(),
      then atomic_add() it later, once everything is done.
      
      Location of this atomic_add() is tricky, because we dont want another
      writer to find this timewait in ehash, while tw_refcnt is still zero !
      
      Thanks to Kapil Dakhane tests and reports.
      Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      47e1c323
    • Eric Dumazet's avatar
      tcp: connect() race with timewait reuse · 13475a30
      Eric Dumazet authored
      Its currently possible that several threads issuing a connect() find
      the same timewait socket and try to reuse it, leading to list
      corruptions.
      
      Condition for bug is that these threads bound their socket on same
      address/port of to-be-find timewait socket, and connected to same
      target. (SO_REUSEADDR needed)
      
      To fix this problem, we could unhash timewait socket while holding
      ehash lock, to make sure lookups/changes will be serialized. Only
      first thread finds the timewait socket, other ones find the
      established socket and return an EADDRNOTAVAIL error.
      
      This second version takes into account Evgeniy's review and makes sure
      inet_twsk_put() is called outside of locked sections.
      Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      13475a30
  30. 03 Dec, 2009 2 commits
    • Eric W. Biederman's avatar
      net: Batch inet_twsk_purge · b099ce26
      Eric W. Biederman authored
      This function walks the whole hashtable so there is no point in
      passing it a network namespace.  Instead I purge all timewait
      sockets from dead network namespaces that I find.  If the namespace
      is one of the once I am trying to purge I am guaranteed no new timewait
      sockets can be formed so this will get them all.  If the namespace
      is one I am not acting for it might form a few more but I will
      call inet_twsk_purge again and  shortly to get rid of them.  In
      any even if the network namespace is dead timewait sockets are
      useless.
      
      Move the calls of inet_twsk_purge into batch_exit routines so
      that if I am killing a bunch of namespaces at once I will just
      call inet_twsk_purge once and save a lot of redundant unnecessary
      work.
      
      My simple 4k network namespace exit test the cleanup time dropped from
      roughly 8.2s to 1.6s.  While the time spent running inet_twsk_purge fell
      to about 2ms.  1ms for ipv4 and 1ms for ipv6.
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      b099ce26
    • Eric W. Biederman's avatar
      net: Use rcu lookups in inet_twsk_purge. · 575f4cd5
      Eric W. Biederman authored
      While we are looking up entries to free there is no reason to take
      the lock in inet_twsk_purge.  We have to drop locks and restart
      occassionally anyway so adding a few more in case we get on the
      wrong list because of a timewait move is no big deal.  At the
      same time not taking the lock for long periods of time is much
      more polite to the rest of the users of the hash table.
      
      In my test configuration of killing 4k network namespaces
      this change causes 4k back to back runs of inet_twsk_purge on an
      empty hash table to go from roughly 20.7s to 3.3s, and the total
      time to destroy 4k network namespaces goes from roughly 44s to
      3.3s.
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Acked-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      575f4cd5
  31. 19 Oct, 2009 1 commit
    • Eric Dumazet's avatar
      inet: rename some inet_sock fields · c720c7e8
      Eric Dumazet authored
      In order to have better cache layouts of struct sock (separate zones
      for rx/tx paths), we need this preliminary patch.
      
      Goal is to transfert fields used at lookup time in the first
      read-mostly cache line (inside struct sock_common) and move sk_refcnt
      to a separate cache line (only written by rx path)
      
      This patch adds inet_ prefix to daddr, rcv_saddr, dport, num, saddr,
      sport and id fields. This allows a future patch to define these
      fields as macros, like sk_refcnt, without name clashes.
      Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      c720c7e8
  32. 13 Oct, 2009 1 commit
  33. 29 Aug, 2009 1 commit
    • Octavian Purdila's avatar
      tcp: fix premature termination of FIN_WAIT2 time-wait sockets · 80a1096b
      Octavian Purdila authored
      There is a race condition in the time-wait sockets code that can lead
      to premature termination of FIN_WAIT2 and, subsequently, to RST
      generation when the FIN,ACK from the peer finally arrives:
      
      Time     TCP header
      0.000000 30755 > http [SYN] Seq=0 Win=2920 Len=0 MSS=1460 TSV=282912 TSER=0
      0.000008 http > 30755 aSYN, ACK] Seq=0 Ack=1 Win=2896 Len=0 MSS=1460 TSV=...
      0.136899 HEAD /1b.html?n1Lg=v1 HTTP/1.0 [Packet size limited during capture]
      0.136934 HTTP/1.0 200 OK [Packet size limited during capture]
      0.136945 http > 30755 [FIN, ACK] Seq=187 Ack=207 Win=2690 Len=0 TSV=270521...
      0.136974 30755 > http [ACK] Seq=207 Ack=187 Win=2734 Len=0 TSV=283049 TSER=...
      0.177983 30755 > http [ACK] Seq=207 Ack=188 Win=2733 Len=0 TSV=283089 TSER=...
      0.238618 30755 > http [FIN, ACK] Seq=207 Ack=188 Win=2733 Len=0 TSV=283151...
      0.238625 http > 30755 [RST] Seq=188 Win=0 Len=0
      
      Say twdr->slot = 1 and we are running inet_twdr_hangman and in this
      instance inet_twdr_do_twkill_work returns 1. At that point we will
      mark slot 1 and schedule inet_twdr_twkill_work. We will also make
      twdr->slot = 2.
      
      Next, a connection is closed and tcp_time_wait(TCP_FIN_WAIT2, timeo)
      is called which will create a new FIN_WAIT2 time-wait socket and will
      place it in the last to be reached slot, i.e. twdr->slot = 1.
      
      At this point say inet_twdr_twkill_work will run which will start
      destroying the time-wait sockets in slot 1, including the just added
      TCP_FIN_WAIT2 one.
      
      To avoid this issue we increment the slot only if all entries in the
      slot have been purged.
      
      This change may delay the slots cleanup by a time-wait death row
      period but only if the worker thread didn't had the time to run/purge
      the current slot in the next period (6 seconds with default sysctl
      settings). However, on such a busy system even without this change we
      would probably see delays...
      Signed-off-by: default avatarOctavian Purdila <opurdila@ixiacom.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      80a1096b
  34. 15 Jun, 2009 1 commit
  35. 06 May, 2009 1 commit