Skip to content

K
Kernel

openeuler / Kernel
1 年多 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 06 8月, 2019 1 次提交
    • D
      net: sched: use temporary variable for actions indexes · 7be8ef2c
      由 Dmytro Linkin 提交于 
      Currently init call of all actions (except ipt) init their 'parm'
structure as a direct pointer to nla data in skb. This leads to race
condition when some of the filter actions were initialized successfully
(and were assigned with idr action index that was written directly
into nla data), but then were deleted and retried (due to following
action module missing or classifier-initiated retry), in which case
action init code tries to insert action to idr with index that was
assigned on previous iteration. During retry the index can be reused
by another action that was inserted concurrently, which causes
unintended action sharing between filters.
To fix described race condition, save action idr index to temporary
stack-allocated variable instead on nla data.

Fixes: 0190c1d4 ("net: sched: atomically check-allocate action")
Signed-off-by: NDmytro Linkin <dmitrolin@mellanox.com>
Signed-off-by: NVlad Buslov <vladbu@mellanox.com>
Acked-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      7be8ef2c
  3. 31 5月, 2019 1 次提交
  5. 06 5月, 2019 2 次提交
  7. 28 4月, 2019 1 次提交
    • J
      netlink: make validation more configurable for future strictness · 8cb08174
      由 Johannes Berg 提交于 
      We currently have two levels of strict validation:

 1) liberal (default)
     - undefined (type >= max) & NLA_UNSPEC attributes accepted
     - attribute length >= expected accepted
     - garbage at end of message accepted
 2) strict (opt-in)
     - NLA_UNSPEC attributes accepted
     - attribute length >= expected accepted

Split out parsing strictness into four different options:
 * TRAILING     - check that there's no trailing data after parsing
                  attributes (in message or nested)
 * MAXTYPE      - reject attrs > max known type
 * UNSPEC       - reject attributes with NLA_UNSPEC policy entries
 * STRICT_ATTRS - strictly validate attribute size

The default for future things should be *everything*.
The current *_strict() is a combination of TRAILING and MAXTYPE,
and is renamed to _deprecated_strict().
The current regular parsing has none of this, and is renamed to
*_parse_deprecated().

Additionally it allows us to selectively set one of the new flags
even on old policies. Notably, the UNSPEC flag could be useful in
this case, since it can be arranged (by filling in the policy) to
not be an incompatible userspace ABI change, but would then going
forward prevent forgetting attribute entries. Similar can apply
to the POLICY flag.

We end up with the following renames:
 * nla_parse           -> nla_parse_deprecated
 * nla_parse_strict    -> nla_parse_deprecated_strict
 * nlmsg_parse         -> nlmsg_parse_deprecated
 * nlmsg_parse_strict  -> nlmsg_parse_deprecated_strict
 * nla_parse_nested    -> nla_parse_nested_deprecated
 * nla_validate_nested -> nla_validate_nested_deprecated

Using spatch, of course:
    @@
    expression TB, MAX, HEAD, LEN, POL, EXT;
    @@
    -nla_parse(TB, MAX, HEAD, LEN, POL, EXT)
    +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT)

    @@
    expression NLH, HDRLEN, TB, MAX, POL, EXT;
    @@
    -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT)
    +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT)

    @@
    expression NLH, HDRLEN, TB, MAX, POL, EXT;
    @@
    -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
    +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT)

    @@
    expression TB, MAX, NLA, POL, EXT;
    @@
    -nla_parse_nested(TB, MAX, NLA, POL, EXT)
    +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT)

    @@
    expression START, MAX, POL, EXT;
    @@
    -nla_validate_nested(START, MAX, POL, EXT)
    +nla_validate_nested_deprecated(START, MAX, POL, EXT)

    @@
    expression NLH, HDRLEN, MAX, POL, EXT;
    @@
    -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT)
    +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT)

For this patch, don't actually add the strict, non-renamed versions
yet so that it breaks compile if I get it wrong.

Also, while at it, make nla_validate and nla_parse go down to a
common __nla_validate_parse() function to avoid code duplication.

Ultimately, this allows us to have very strict validation for every
new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the
next patch, while existing things will continue to work as is.

In effect then, this adds fully strict validation for any new command.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      8cb08174
  9. 22 3月, 2019 2 次提交
    • D
      net/sched: act_police: validate the control action inside init() · d6124d6b
      由 Davide Caratti 提交于 
      the following script:

 # tc qdisc add dev crash0 clsact
 # tc filter add dev crash0 egress matchall \
 > action police rate 3mbit burst 250k pass index 90
 # tc actions replace action police \
 > rate 3mbit burst 250k goto chain 42 index 90 cookie c1a0c1a0
 # tc actions show action police rate 3mbit burst

had the following output:

 Error: Failed to init TC action chain.
 We have an error talking to the kernel
 total acts 1

         action order 0:  police 0x5a rate 3Mbit burst 250Kb mtu 2Kb  action goto chain 42 overhead 0b
         ref 2 bind 1
         cookie c1a0c1a0

Then, when crash0 starts transmitting more than 3Mbit/s, the following
kernel crash is observed:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 #PF error: [normal kernel read fault]
 PGD 800000007a779067 P4D 800000007a779067 PUD 2ad96067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 3 PID: 5032 Comm: netperf Not tainted 5.0.0-rc4.gotochain_crash+ #533
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 RIP: 0010:tcf_action_exec+0xb8/0x100
 Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
 RSP: 0018:ffffb0e04064fa60 EFLAGS: 00010246
 RAX: 000000002000002a RBX: ffff93bb3322cce0 RCX: 0000000000000005
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff93bb3322cce0
 RBP: ffffb0e04064fb00 R08: 0000000000000022 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000001 R12: ffff93bb3beed300
 R13: ffff93bb3beed308 R14: 0000000000000001 R15: ffff93bb3b64d000
 FS:  00007f0bc6be5740(0000) GS:ffff93bb3db80000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 00000000746a8001 CR4: 00000000001606e0
 Call Trace:
  tcf_classify+0x58/0x120
  __dev_queue_xmit+0x40a/0x890
  ? ipt_do_table+0x31c/0x420 [ip_tables]
  ? ip_finish_output2+0x16f/0x430
  ip_finish_output2+0x16f/0x430
  ? ip_output+0x69/0xe0
  ip_output+0x69/0xe0
  ? ip_forward_options+0x1a0/0x1a0
  __tcp_transmit_skb+0x563/0xa40
  tcp_write_xmit+0x243/0xfa0
  __tcp_push_pending_frames+0x32/0xf0
  tcp_sendmsg_locked+0x404/0xd30
  tcp_sendmsg+0x27/0x40
  sock_sendmsg+0x36/0x40
  __sys_sendto+0x10e/0x140
  ? __sys_connect+0x87/0xf0
  ? syscall_trace_enter+0x1df/0x2e0
  ? __audit_syscall_exit+0x216/0x260
  __x64_sys_sendto+0x24/0x30
  do_syscall_64+0x5b/0x180
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7f0bc5ffbafd
 Code: 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 8b 05 ae c4 2c 00 85 c0 75 2d 45 31 c9 45 31 c0 4c 63 d1 48 63 ff b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 63 63 2c 00 f7 d8 64 89 02 48
 RSP: 002b:00007fffef94b7f8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
 RAX: ffffffffffffffda RBX: 0000000000004000 RCX: 00007f0bc5ffbafd
 RDX: 0000000000004000 RSI: 00000000017e5420 RDI: 0000000000000004
 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
 R13: 00000000017e51d0 R14: 0000000000000010 R15: 0000000000000006
 Modules linked in: act_police veth ip6table_filter ip6_tables iptable_filter binfmt_misc ext4 snd_hda_codec_generic mbcache crct10dif_pclmul jbd2 crc32_pclmul ghash_clmulni_intel snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_seq snd_seq_device snd_pcm aesni_intel crypto_simd cryptd glue_helper snd_timer snd joydev pcspkr virtio_balloon soundcore i2c_piix4 nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs ata_generic pata_acpi qxl drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm virtio_blk virtio_net virtio_console net_failover failover crc32c_intel ata_piix libata serio_raw virtio_pci virtio_ring virtio floppy dm_mirror dm_region_hash dm_log dm_mod
 CR2: 0000000000000000

Validating the control action within tcf_police_init() proved to fix the
above issue. A TDC selftest is added to verify the correct behavior.

Fixes: db50514f ("net: sched: add termination action to allow goto chain")
Fixes: 97763dc0 ("net_sched: reject unknown tcfa_action values")
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      d6124d6b
    • D
      net/sched: prepare TC actions to properly validate the control action · 85d0966f
      由 Davide Caratti 提交于 
      - pass a pointer to struct tcf_proto in each actions's init() handler,
  to allow validating the control action, checking whether the chain
  exists and (eventually) refcounting it.
- remove code that validates the control action after a successful call
  to the action's init() handler, and replace it with a test that forbids
  addition of actions having 'goto_chain' and NULL goto_chain pointer at
  the same time.
- add tcf_action_check_ctrlact(), that will validate the control action
  and eventually allocate the action 'goto_chain' within the init()
  handler.
- add tcf_action_set_ctrlact(), that will assign the control action and
  swap the current 'goto_chain' pointer with the new given one.

This disallows 'goto_chain' on actions that don't initialize it properly
in their init() handler, i.e. calling tcf_action_check_ctrlact() after
successful IDR reservation and then calling tcf_action_set_ctrlact()
to assign 'goto_chain' and 'tcf_action' consistently.

By doing this, the kernel does not leak anymore refcounts when a valid
'goto chain' handle is replaced in TC actions, causing kmemleak splats
like the following one:

 # tc chain add dev dd0 chain 42 ingress protocol ip flower \
 > ip_proto tcp action drop
 # tc chain add dev dd0 chain 43 ingress protocol ip flower \
 > ip_proto udp action drop
 # tc filter add dev dd0 ingress matchall \
 > action gact goto chain 42 index 66
 # tc filter replace dev dd0 ingress matchall \
 > action gact goto chain 43 index 66
 # echo scan >/sys/kernel/debug/kmemleak
 <...>
 unreferenced object 0xffff93c0ee09f000 (size 1024):
 comm "tc", pid 2565, jiffies 4295339808 (age 65.426s)
 hex dump (first 32 bytes):
   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
   00 00 00 00 08 00 06 00 00 00 00 00 00 00 00 00  ................
 backtrace:
   [<000000009b63f92d>] tc_ctl_chain+0x3d2/0x4c0
   [<00000000683a8d72>] rtnetlink_rcv_msg+0x263/0x2d0
   [<00000000ddd88f8e>] netlink_rcv_skb+0x4a/0x110
   [<000000006126a348>] netlink_unicast+0x1a0/0x250
   [<00000000b3340877>] netlink_sendmsg+0x2c1/0x3c0
   [<00000000a25a2171>] sock_sendmsg+0x36/0x40
   [<00000000f19ee1ec>] ___sys_sendmsg+0x280/0x2f0
   [<00000000d0422042>] __sys_sendmsg+0x5e/0xa0
   [<000000007a6c61f9>] do_syscall_64+0x5b/0x180
   [<00000000ccd07542>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
   [<0000000013eaa334>] 0xffffffffffffffff

Fixes: db50514f ("net: sched: add termination action to allow goto chain")
Fixes: 97763dc0 ("net_sched: reject unknown tcfa_action values")
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      85d0966f
  11. 11 2月, 2019 1 次提交
  13. 01 12月, 2018 1 次提交
    • D
      net/sched: act_police: fix memory leak in case of invalid control action · fd6d4338
      由 Davide Caratti 提交于 
      when users set an invalid control action, kmemleak complains as follows:

 # echo clear >/sys/kernel/debug/kmemleak
 # ./tdc.py -e b48b
 Test b48b: Add police action with exceed goto chain control action
 All test results:

 1..1
 ok 1 - b48b # Add police action with exceed goto chain control action
 about to flush the tap output if tests need to be skipped
 done flushing skipped test tap output
 # echo scan >/sys/kernel/debug/kmemleak
 # cat /sys/kernel/debug/kmemleak
 unreferenced object 0xffffa0fafbc3dde0 (size 96):
  comm "tc", pid 2358, jiffies 4294922738 (age 17.022s)
  hex dump (first 32 bytes):
    2a 00 00 20 00 00 00 00 00 00 7d 00 00 00 00 00  *.. ......}.....
    f8 07 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000648803d2>] tcf_action_init_1+0x384/0x4c0
    [<00000000cb69382e>] tcf_action_init+0x12b/0x1a0
    [<00000000847ef0d4>] tcf_action_add+0x73/0x170
    [<0000000093656e14>] tc_ctl_action+0x122/0x160
    [<0000000023c98e32>] rtnetlink_rcv_msg+0x263/0x2d0
    [<000000003493ae9c>] netlink_rcv_skb+0x4d/0x130
    [<00000000de63f8ba>] netlink_unicast+0x209/0x2d0
    [<00000000c3da0ebe>] netlink_sendmsg+0x2c1/0x3c0
    [<000000007a9e0753>] sock_sendmsg+0x33/0x40
    [<00000000457c6d2e>] ___sys_sendmsg+0x2a0/0x2f0
    [<00000000c5c6a086>] __sys_sendmsg+0x5e/0xa0
    [<00000000446eafce>] do_syscall_64+0x5b/0x180
    [<000000004aa871f2>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
    [<00000000450c38ef>] 0xffffffffffffffff

change tcf_police_init() to avoid leaking 'new' in case TCA_POLICE_RESULT
contains TC_ACT_GOTO_CHAIN extended action.

Fixes: c08f5ed5 ("net/sched: act_police: disallow 'goto chain' on fallback control action")
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Acked-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      fd6d4338
  15. 24 11月, 2018 1 次提交
    • D
      net/sched: act_police: add missing spinlock initialization · 484afd1b
      由 Davide Caratti 提交于 
      commit f2cbd485 ("net/sched: act_police: fix race condition on state
variables") introduces a new spinlock, but forgets its initialization.
Ensure that tcf_police_init() initializes 'tcfp_lock' every time a 'police'
action is newly created, to avoid the following lockdep splat:

 INFO: trying to register non-static key.
 the code is fine but needs lockdep annotation.
 turning off the locking correctness validator.
 <...>
 Call Trace:
  dump_stack+0x85/0xcb
  register_lock_class+0x581/0x590
  __lock_acquire+0xd4/0x1330
  ? tcf_police_init+0x2fa/0x650 [act_police]
  ? lock_acquire+0x9e/0x1a0
  lock_acquire+0x9e/0x1a0
  ? tcf_police_init+0x2fa/0x650 [act_police]
  ? tcf_police_init+0x55a/0x650 [act_police]
  _raw_spin_lock_bh+0x34/0x40
  ? tcf_police_init+0x2fa/0x650 [act_police]
  tcf_police_init+0x2fa/0x650 [act_police]
  tcf_action_init_1+0x384/0x4c0
  tcf_action_init+0xf6/0x160
  tcf_action_add+0x73/0x170
  tc_ctl_action+0x122/0x160
  rtnetlink_rcv_msg+0x2a4/0x490
  ? netlink_deliver_tap+0x99/0x400
  ? validate_linkmsg+0x370/0x370
  netlink_rcv_skb+0x4d/0x130
  netlink_unicast+0x196/0x230
  netlink_sendmsg+0x2e5/0x3e0
  sock_sendmsg+0x36/0x40
  ___sys_sendmsg+0x280/0x2f0
  ? _raw_spin_unlock+0x24/0x30
  ? handle_pte_fault+0xafe/0xf30
  ? find_held_lock+0x2d/0x90
  ? syscall_trace_enter+0x1df/0x360
  ? __sys_sendmsg+0x5e/0xa0
  __sys_sendmsg+0x5e/0xa0
  do_syscall_64+0x60/0x210
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
 RIP: 0033:0x7f1841c7cf10
 Code: c3 48 8b 05 82 6f 2c 00 f7 db 64 89 18 48 83 cb ff eb dd 0f 1f 80 00 00 00 00 83 3d 8d d0 2c 00 00 75 10 b8 2e 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ae cc 00 00 48 89 04 24
 RSP: 002b:00007ffcf9df4d68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f1841c7cf10
 RDX: 0000000000000000 RSI: 00007ffcf9df4dc0 RDI: 0000000000000003
 RBP: 000000005bf56105 R08: 0000000000000002 R09: 00007ffcf9df8edc
 R10: 00007ffcf9df47e0 R11: 0000000000000246 R12: 0000000000671be0
 R13: 00007ffcf9df4e84 R14: 0000000000000008 R15: 0000000000000000

Fixes: f2cbd485 ("net/sched: act_police: fix race condition on state variables")
Reported-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Acked-by: NCong Wang <xiyou.wangcong@gmail.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      484afd1b
  17. 21 11月, 2018 1 次提交
    • D
      net/sched: act_police: fix race condition on state variables · f2cbd485
      由 Davide Caratti 提交于 
      after 'police' configuration parameters were converted to use RCU instead
of spinlock, the state variables used to compute the traffic rate (namely
'tcfp_toks', 'tcfp_ptoks' and 'tcfp_t_c') are erroneously read/updated in
the traffic path without any protection.

Use a dedicated spinlock to avoid race conditions on these variables, and
ensure proper cache-line alignment. In this way, 'police' is still faster
than what we observed when 'tcf_lock' was used in the traffic path _ i.e.
reverting commit 2d550dba ("net/sched: act_police: don't use spinlock
in the data path"). Moreover, we preserve the throughput improvement that
was obtained after 'police' started using per-cpu counters, when 'avrate'
is used instead of 'rate'.

Changes since v1 (thanks to Eric Dumazet):
- call ktime_get_ns() before acquiring the lock in the traffic path
- use a dedicated spinlock instead of tcf_lock
- improve cache-line usage

Fixes: 2d550dba ("net/sched: act_police: don't use spinlock in the data path")
Reported-and-suggested-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
      f2cbd485
  19. 23 10月, 2018 1 次提交
  21. 17 9月, 2018 2 次提交
  23. 01 9月, 2018 1 次提交
  25. 22 8月, 2018 1 次提交
  27. 14 8月, 2018 1 次提交
  29. 12 8月, 2018 1 次提交
  31. 08 7月, 2018 5 次提交
  33. 28 3月, 2018 1 次提交
  35. 22 3月, 2018 1 次提交
    • D
      net/sched: fix idr leak in the error path of tcf_act_police_init() · 5bf7f818
      由 Davide Caratti 提交于 
      tcf_act_police_init() can fail after the idr has been successfully
reserved (e.g., qdisc_get_rtab() may return NULL). When this happens,
subsequent attempts to configure a police rule using the same idr value
systematiclly fail with -ENOSPC:

 # tc action add action police rate 1000 burst 1000 drop index 100
 RTNETLINK answers: Cannot allocate memory
 We have an error talking to the kernel
 # tc action add action police rate 1000 burst 1000 drop index 100
 RTNETLINK answers: No space left on device
 We have an error talking to the kernel
 # tc action add action police rate 1000 burst 1000 drop index 100
 RTNETLINK answers: No space left on device
 ...

Fix this in the error path of tcf_act_police_init(), calling
tcf_idr_release() in place of tcf_idr_cleanup().

Fixes: 65a206c0 ("net/sched: Change act_api and act_xxx modules to use IDR")
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      5bf7f818
  37. 28 2月, 2018 1 次提交
    • K
      net: Convert tc_action_net_init() and tc_action_net_exit() based pernet_operations · 685ecfb1
      由 Kirill Tkhai 提交于 
      These pernet_operations are from net/sched directory, and they call only
tc_action_net_init() and tc_action_net_exit():

bpf_net_ops
connmark_net_ops
csum_net_ops
gact_net_ops
ife_net_ops
ipt_net_ops
xt_net_ops
mirred_net_ops
nat_net_ops
pedit_net_ops
police_net_ops
sample_net_ops
simp_net_ops
skbedit_net_ops
skbmod_net_ops
tunnel_key_net_ops
vlan_net_ops

1)tc_action_net_init() just allocates and initializes per-net memory.
2)There should not be in-flight packets at the time of tc_action_net_exit()
call, or another pernet_operations send packets to dying net (except
netlink). So, it seems they can be marked as async.
Signed-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      685ecfb1
  39. 17 2月, 2018 4 次提交
  41. 22 12月, 2017 1 次提交
  43. 14 12月, 2017 1 次提交
  45. 09 11月, 2017 1 次提交
  47. 03 11月, 2017 1 次提交
  49. 31 8月, 2017 1 次提交
  51. 15 6月, 2017 1 次提交
  53. 14 4月, 2017 1 次提交
  55. 06 12月, 2016 1 次提交
    • E
      net_sched: gen_estimator: complete rewrite of rate estimators · 1c0d32fd
      由 Eric Dumazet 提交于 
      1) Old code was hard to maintain, due to complex lock chains.
   (We probably will be able to remove some kfree_rcu() in callers)

2) Using a single timer to update all estimators does not scale.

3) Code was buggy on 32bit kernel (WRITE_ONCE() on 64bit quantity
   is not supposed to work well)

In this rewrite :

- I removed the RB tree that had to be scanned in
  gen_estimator_active(). qdisc dumps should be much faster.

- Each estimator has its own timer.

- Estimations are maintained in net_rate_estimator structure,
  instead of dirtying the qdisc. Minor, but part of the simplification.

- Reading the estimator uses RCU and a seqcount to provide proper
  support for 32bit kernels.

- We reduce memory need when estimators are not used, since
  we store a pointer, instead of the bytes/packets counters.

- xt_rateest_mt() no longer has to grab a spinlock.
  (In the future, xt_rateest_tg() could be switched to per cpu counters)
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      1c0d32fd
  57. 18 11月, 2016 1 次提交
    • A
      netns: make struct pernet_operations::id unsigned int · c7d03a00
      由 Alexey Dobriyan 提交于 
      Make struct pernet_operations::id unsigned.

There are 2 reasons to do so:

1)
This field is really an index into an zero based array and
thus is unsigned entity. Using negative value is out-of-bound
access by definition.

2)
On x86_64 unsigned 32-bit data which are mixed with pointers
via array indexing or offsets added or subtracted to pointers
are preffered to signed 32-bit data.

"int" being used as an array index needs to be sign-extended
to 64-bit before being used.

	void f(long *p, int i)
	{
		g(p[i]);
	}

  roughly translates to

	movsx	rsi, esi
	mov	rdi, [rsi+...]
	call 	g

MOVSX is 3 byte instruction which isn't necessary if the variable is
unsigned because x86_64 is zero extending by default.

Now, there is net_generic() function which, you guessed it right, uses
"int" as an array index:

	static inline void *net_generic(const struct net *net, int id)
	{
		...
		ptr = ng->ptr[id - 1];
		...
	}

And this function is used a lot, so those sign extensions add up.

Patch snipes ~1730 bytes on allyesconfig kernel (without all junk
messing with code generation):

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)

Unfortunately some functions actually grow bigger.
This is a semmingly random artefact of code generation with register
allocator being used differently. gcc decides that some variable
needs to live in new r8+ registers and every access now requires REX
prefix. Or it is shifted into r12, so [r12+0] addressing mode has to be
used which is longer than [r8]

However, overall balance is in negative direction:

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)
	function                                     old     new   delta
	nfsd4_lock                                  3886    3959     +73
	tipc_link_build_proto_msg                   1096    1140     +44
	mac80211_hwsim_new_radio                    2776    2808     +32
	tipc_mon_rcv                                1032    1058     +26
	svcauth_gss_legacy_init                     1413    1429     +16
	tipc_bcbase_select_primary                   379     392     +13
	nfsd4_exchange_id                           1247    1260     +13
	nfsd4_setclientid_confirm                    782     793     +11
		...
	put_client_renew_locked                      494     480     -14
	ip_set_sockfn_get                            730     716     -14
	geneve_sock_add                              829     813     -16
	nfsd4_sequence_done                          721     703     -18
	nlmclnt_lookup_host                          708     686     -22
	nfsd4_lockt                                 1085    1063     -22
	nfs_get_client                              1077    1050     -27
	tcf_bpf_init                                1106    1076     -30
	nfsd4_encode_fattr                          5997    5930     -67
	Total: Before=154856051, After=154854321, chg -0.00%
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      c7d03a00
  59. 20 9月, 2016 1 次提交