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Author SHA1 Message Date
Yunsheng Lin 102b55ee92 net: sched: fix tx action rescheduling issue during deactivation 
Currently qdisc_run() checks the STATE_DEACTIVATED of lockless
qdisc before calling __qdisc_run(), which ultimately clear the
STATE_MISSED when all the skb is dequeued. If STATE_DEACTIVATED
is set before clearing STATE_MISSED, there may be rescheduling
of net_tx_action() at the end of qdisc_run_end(), see below:

CPU0(net_tx_atcion)  CPU1(__dev_xmit_skb)  CPU2(dev_deactivate)
          .                   .                     .
          .            set STATE_MISSED             .
          .           __netif_schedule()            .
          .                   .           set STATE_DEACTIVATED
          .                   .                qdisc_reset()
          .                   .                     .
          .<---------------   .              synchronize_net()
clear __QDISC_STATE_SCHED  |  .                     .
          .                |  .                     .
          .                |  .            some_qdisc_is_busy()
          .                |  .               return *false*
          .                |  .                     .
  test STATE_DEACTIVATED   |  .                     .
__qdisc_run() *not* called |  .                     .
          .                |  .                     .
   test STATE_MISS         |  .                     .
 __netif_schedule()--------|  .                     .
          .                   .                     .
          .                   .                     .

__qdisc_run() is not called by net_tx_atcion() in CPU0 because
CPU2 has set STATE_DEACTIVATED flag during dev_deactivate(), and
STATE_MISSED is only cleared in __qdisc_run(), __netif_schedule
is called at the end of qdisc_run_end(), causing tx action
rescheduling problem.

qdisc_run() called by net_tx_action() runs in the softirq context,
which should has the same semantic as the qdisc_run() called by
__dev_xmit_skb() protected by rcu_read_lock_bh(). And there is a
synchronize_net() between STATE_DEACTIVATED flag being set and
qdisc_reset()/some_qdisc_is_busy in dev_deactivate(), we can safely
bail out for the deactived lockless qdisc in net_tx_action(), and
qdisc_reset() will reset all skb not dequeued yet.

So add the rcu_read_lock() explicitly to protect the qdisc_run()
and do the STATE_DEACTIVATED checking in net_tx_action() before
calling qdisc_run_begin(). Another option is to do the checking in
the qdisc_run_end(), but it will add unnecessary overhead for
non-tx_action case, because __dev_queue_xmit() will not see qdisc
with STATE_DEACTIVATED after synchronize_net(), the qdisc with
STATE_DEACTIVATED can only be seen by net_tx_action() because of
__netif_schedule().

The STATE_DEACTIVATED checking in qdisc_run() is to avoid race
between net_tx_action() and qdisc_reset(), see:
commit d518d2ed86 ("net/sched: fix race between deactivation
and dequeue for NOLOCK qdisc"). As the bailout added above for
deactived lockless qdisc in net_tx_action() provides better
protection for the race without calling qdisc_run() at all, so
remove the STATE_DEACTIVATED checking in qdisc_run().

After qdisc_reset(), there is no skb in qdisc to be dequeued, so
clear the STATE_MISSED in dev_reset_queue() too.

Fixes: 6b3ba9146f ("net: sched: allow qdiscs to handle locking")
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
V8: Clearing STATE_MISSED before calling __netif_schedule() has
    avoid the endless rescheduling problem, but there may still
    be a unnecessary rescheduling, so adjust the commit log.
Signed-off-by: David S. Miller <davem@davemloft.net>
 2021-05-14 15:05:46 -07:00
Yunsheng Lin a90c57f2ce net: sched: fix packet stuck problem for lockless qdisc 
Lockless qdisc has below concurrent problem:
    cpu0                 cpu1
     .                     .
q->enqueue                 .
     .                     .
qdisc_run_begin()          .
     .                     .
dequeue_skb()              .
     .                     .
sch_direct_xmit()          .
     .                     .
     .                q->enqueue
     .             qdisc_run_begin()
     .            return and do nothing
     .                     .
qdisc_run_end()            .

cpu1 enqueue a skb without calling __qdisc_run() because cpu0
has not released the lock yet and spin_trylock() return false
for cpu1 in qdisc_run_begin(), and cpu0 do not see the skb
enqueued by cpu1 when calling dequeue_skb() because cpu1 may
enqueue the skb after cpu0 calling dequeue_skb() and before
cpu0 calling qdisc_run_end().

Lockless qdisc has below another concurrent problem when
tx_action is involved:

cpu0(serving tx_action)     cpu1             cpu2
          .                   .                .
          .              q->enqueue            .
          .            qdisc_run_begin()       .
          .              dequeue_skb()         .
          .                   .            q->enqueue
          .                   .                .
          .             sch_direct_xmit()      .
          .                   .         qdisc_run_begin()
          .                   .       return and do nothing
          .                   .                .
 clear __QDISC_STATE_SCHED    .                .
 qdisc_run_begin()            .                .
 return and do nothing        .                .
          .                   .                .
          .            qdisc_run_end()         .

This patch fixes the above data race by:
1. If the first spin_trylock() return false and STATE_MISSED is
   not set, set STATE_MISSED and retry another spin_trylock() in
   case other CPU may not see STATE_MISSED after it releases the
   lock.
2. reschedule if STATE_MISSED is set after the lock is released
   at the end of qdisc_run_end().

For tx_action case, STATE_MISSED is also set when cpu1 is at the
end if qdisc_run_end(), so tx_action will be rescheduled again
to dequeue the skb enqueued by cpu2.

Clear STATE_MISSED before retrying a dequeuing when dequeuing
returns NULL in order to reduce the overhead of the second
spin_trylock() and __netif_schedule() calling.

Also clear the STATE_MISSED before calling __netif_schedule()
at the end of qdisc_run_end() to avoid doing another round of
dequeuing in the pfifo_fast_dequeue().

The performance impact of this patch, tested using pktgen and
dummy netdev with pfifo_fast qdisc attached:

 threads  without+this_patch   with+this_patch      delta
    1        2.61Mpps            2.60Mpps           -0.3%
    2        3.97Mpps            3.82Mpps           -3.7%
    4        5.62Mpps            5.59Mpps           -0.5%
    8        2.78Mpps            2.77Mpps           -0.3%
   16        2.22Mpps            2.22Mpps           -0.0%

Fixes: 6b3ba9146f ("net: sched: allow qdiscs to handle locking")
Acked-by: Jakub Kicinski <kuba@kernel.org>
Tested-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2021-05-14 15:05:46 -07:00
Baowen Zheng 2ffe039528 net/sched: act_police: add support for packet-per-second policing 
Allow a policer action to enforce a rate-limit based on packets-per-second,
configurable using a packet-per-second rate and burst parameters.

e.g.
tc filter add dev tap1 parent ffff: u32 match \
        u32 0 0 police pkts_rate 3000 pkts_burst 1000

Testing was unable to uncover a performance impact of this change on
existing features.

Signed-off-by: Baowen Zheng <baowen.zheng@corigine.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: Louis Peens <louis.peens@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2021-03-13 14:18:09 -08:00
Eric Dumazet 846e463a70 net/sched: get rid of qdisc->padded 
kmalloc() of sufficiently big portion of memory is cache-aligned
in regular conditions. If some debugging options are used,
there is no reason qdisc structures would need 64-byte alignment
if most other kernel structures are not aligned.

This get rid of QDISC_ALIGN and QDISC_ALIGNTO.

Addition of privdata field will help implementing
the reverse of qdisc_priv() and documents where
the private data is.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Allen Pais <allen.lkml@gmail.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2020-10-09 08:08:08 -07:00
Yunsheng Lin 2fb541c862 net: sch_generic: aviod concurrent reset and enqueue op for lockless qdisc 
Currently there is concurrent reset and enqueue operation for the
same lockless qdisc when there is no lock to synchronize the
q->enqueue() in __dev_xmit_skb() with the qdisc reset operation in
qdisc_deactivate() called by dev_deactivate_queue(), which may cause
out-of-bounds access for priv->ring[] in hns3 driver if user has
requested a smaller queue num when __dev_xmit_skb() still enqueue a
skb with a larger queue_mapping after the corresponding qdisc is
reset, and call hns3_nic_net_xmit() with that skb later.

Reused the existing synchronize_net() in dev_deactivate_many() to
make sure skb with larger queue_mapping enqueued to old qdisc(which
is saved in dev_queue->qdisc_sleeping) will always be reset when
dev_reset_queue() is called.

Fixes: 6b3ba9146f ("net: sched: allow qdiscs to handle locking")
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2020-09-10 12:38:26 -07:00
Valentin Longchamp 1a3db27ad9 net: sched: export __netdev_watchdog_up() 
Since the quiesce/activate rework, __netdev_watchdog_up() is directly
called in the ucc_geth driver.

Unfortunately, this function is not available for modules and thus
ucc_geth cannot be built as a module anymore. Fix it by exporting
__netdev_watchdog_up().

Since the commit introducing the regression was backported to stable
branches, this one should ideally be as well.

Fixes: 79dde73cf9 ("net/ethernet/freescale: rework quiesce/activate for ucc_geth")
Signed-off-by: Valentin Longchamp <valentin@longchamp.me>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2020-06-09 13:14:31 -07:00
Cong Wang 759ae57f1b net_sched: get rid of unnecessary dev_qdisc_reset() 
Resetting old qdisc on dev_queue->qdisc_sleeping in
dev_qdisc_reset() is redundant, because this qdisc,
even if not same with dev_queue->qdisc, is reset via
qdisc_put() right after calling dev_graft_qdisc() when
hitting refcnt 0.

This is very easy to observe with qdisc_reset() tracepoint
and stack traces.

Reported-by: Václav Zindulka <vaclav.zindulka@tlapnet.cz>
Tested-by: Václav Zindulka <vaclav.zindulka@tlapnet.cz>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2020-05-27 15:05:49 -07:00
Cong Wang 70f5096533 net_sched: avoid resetting active qdisc for multiple times 
Except for sch_mq and sch_mqprio, each dev queue points to the
same root qdisc, so when we reset the dev queues with
netdev_for_each_tx_queue() we end up resetting the same instance
of the root qdisc for multiple times.

Avoid this by checking the __QDISC_STATE_DEACTIVATED bit in
each iteration, so for sch_mq/sch_mqprio, we still reset all
of them like before, for the rest, we only reset it once.

Reported-by: Václav Zindulka <vaclav.zindulka@tlapnet.cz>
Tested-by: Václav Zindulka <vaclav.zindulka@tlapnet.cz>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2020-05-27 15:05:49 -07:00
Cong Wang f5a7833e83 net_sched: add a tracepoint for qdisc creation 
With this tracepoint, we could know when qdisc's are created,
especially those default qdisc's.

Sample output:

  tc-736   [001] ...1    56.230107: qdisc_create: dev=ens3 kind=pfifo parent=1:0
  tc-736   [001] ...1    56.230113: qdisc_create: dev=ens3 kind=hfsc parent=ffff:ffff
  tc-738   [001] ...1    56.256816: qdisc_create: dev=ens3 kind=pfifo parent=1:100
  tc-739   [001] ...1    56.267584: qdisc_create: dev=ens3 kind=pfifo parent=1:200
  tc-740   [001] ...1    56.279649: qdisc_create: dev=ens3 kind=fq_codel parent=1:100
  tc-741   [001] ...1    56.289996: qdisc_create: dev=ens3 kind=pfifo_fast parent=1:200
  tc-745   [000] .N.1   111.687483: qdisc_create: dev=ens3 kind=ingress parent=ffff:fff1

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2020-05-27 15:05:49 -07:00
Cong Wang a34dac0b90 net_sched: add tracepoints for qdisc_reset() and qdisc_destroy() 
Add two tracepoints for qdisc_reset() and qdisc_destroy() to track
qdisc resetting and destroying.

Sample output:

  tc-756   [000] ...3   138.355662: qdisc_reset: dev=ens3 kind=pfifo_fast parent=ffff:ffff handle=0:0
  tc-756   [000] ...1   138.355720: qdisc_reset: dev=ens3 kind=pfifo_fast parent=ffff:ffff handle=0:0
  tc-756   [000] ...1   138.355867: qdisc_reset: dev=ens3 kind=pfifo_fast parent=ffff:ffff handle=0:0
  tc-756   [000] ...1   138.355930: qdisc_destroy: dev=ens3 kind=pfifo_fast parent=ffff:ffff handle=0:0
  tc-757   [000] ...2   143.073780: qdisc_reset: dev=ens3 kind=fq_codel parent=ffff:ffff handle=8001:0
  tc-757   [000] ...1   143.073878: qdisc_reset: dev=ens3 kind=fq_codel parent=ffff:ffff handle=8001:0
  tc-757   [000] ...1   143.074114: qdisc_reset: dev=ens3 kind=fq_codel parent=ffff:ffff handle=8001:0
  tc-757   [000] ...1   143.074228: qdisc_destroy: dev=ens3 kind=fq_codel parent=ffff:ffff handle=8001:0

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2020-05-27 15:05:49 -07:00
Cong Wang 4909daba37 net_sched: use qdisc_reset() in qdisc_destroy() 
qdisc_destroy() calls ops->reset() and cleans up qdisc->gso_skb
and qdisc->skb_bad_txq, these are nearly same with qdisc_reset(),
so just call it directly, and cosolidate the code for the next
patch.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2020-05-27 15:05:49 -07:00
Cong Wang 1a33e10e4a net: partially revert dynamic lockdep key changes 
This patch reverts the folowing commits:

commit 064ff66e2b
"bonding: add missing netdev_update_lockdep_key()"

commit 53d374979e
"net: avoid updating qdisc_xmit_lock_key in netdev_update_lockdep_key()"

commit 1f26c0d3d2
"net: fix kernel-doc warning in <linux/netdevice.h>"

commit ab92d68fc2
"net: core: add generic lockdep keys"

but keeps the addr_list_lock_key because we still lock
addr_list_lock nestedly on stack devices, unlikely xmit_lock
this is safe because we don't take addr_list_lock on any fast
path.

Reported-and-tested-by: syzbot+aaa6fa4949cc5d9b7b25@syzkaller.appspotmail.com
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2020-05-04 12:05:56 -07:00
Jesper Dangaard Brouer bf6dba76d2 net: sched: fallback to qdisc noqueue if default qdisc setup fail 
Currently if the default qdisc setup/init fails, the device ends up with
qdisc "noop", which causes all TX packets to get dropped.

With the introduction of sysctl net/core/default_qdisc it is possible
to change the default qdisc to be more advanced, which opens for the
possibility that Qdisc_ops->init() can fail.

This patch detect these kind of failures, and choose to fallback to
qdisc "noqueue", which is so simple that its init call will not fail.
This allows the interface to continue functioning.

V2:
As this also captures memory failures, which are transient, the
device is not kept in IFF_NO_QUEUE state.  This allows the net_device
to retry to default qdisc assignment.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2020-05-04 11:50:51 -07:00
Paul Blakey 7d17c544cd net: sched: Pass ingress block to tcf_classify_ingress 
On ingress and cls_act qdiscs init, save the block on ingress
mini_Qdisc and and pass it on to ingress classification, so it
can be used for the looking up a specified chain index.

Co-developed-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
 2020-02-19 17:49:48 -08:00
Michael S. Tsirkin 0290bd291c netdev: pass the stuck queue to the timeout handler 
This allows incrementing the correct timeout statistic without any mess.
Down the road, devices can learn to reset just the specific queue.

The patch was generated with the following script:

use strict;
use warnings;

our $^I = '.bak';

my @work = (
["arch/m68k/emu/nfeth.c", "nfeth_tx_timeout"],
["arch/um/drivers/net_kern.c", "uml_net_tx_timeout"],
["arch/um/drivers/vector_kern.c", "vector_net_tx_timeout"],
["arch/xtensa/platforms/iss/network.c", "iss_net_tx_timeout"],
["drivers/char/pcmcia/synclink_cs.c", "hdlcdev_tx_timeout"],
["drivers/infiniband/ulp/ipoib/ipoib_main.c", "ipoib_timeout"],
["drivers/infiniband/ulp/ipoib/ipoib_main.c", "ipoib_timeout"],
["drivers/message/fusion/mptlan.c", "mpt_lan_tx_timeout"],
["drivers/misc/sgi-xp/xpnet.c", "xpnet_dev_tx_timeout"],
["drivers/net/appletalk/cops.c", "cops_timeout"],
["drivers/net/arcnet/arcdevice.h", "arcnet_timeout"],
["drivers/net/arcnet/arcnet.c", "arcnet_timeout"],
["drivers/net/arcnet/com20020.c", "arcnet_timeout"],
["drivers/net/ethernet/3com/3c509.c", "el3_tx_timeout"],
["drivers/net/ethernet/3com/3c515.c", "corkscrew_timeout"],
["drivers/net/ethernet/3com/3c574_cs.c", "el3_tx_timeout"],
["drivers/net/ethernet/3com/3c589_cs.c", "el3_tx_timeout"],
["drivers/net/ethernet/3com/3c59x.c", "vortex_tx_timeout"],
["drivers/net/ethernet/3com/3c59x.c", "vortex_tx_timeout"],
["drivers/net/ethernet/3com/typhoon.c", "typhoon_tx_timeout"],
["drivers/net/ethernet/8390/8390.h", "ei_tx_timeout"],
["drivers/net/ethernet/8390/8390.h", "eip_tx_timeout"],
["drivers/net/ethernet/8390/8390.c", "ei_tx_timeout"],
["drivers/net/ethernet/8390/8390p.c", "eip_tx_timeout"],
["drivers/net/ethernet/8390/ax88796.c", "ax_ei_tx_timeout"],
["drivers/net/ethernet/8390/axnet_cs.c", "axnet_tx_timeout"],
["drivers/net/ethernet/8390/etherh.c", "__ei_tx_timeout"],
["drivers/net/ethernet/8390/hydra.c", "__ei_tx_timeout"],
["drivers/net/ethernet/8390/mac8390.c", "__ei_tx_timeout"],
["drivers/net/ethernet/8390/mcf8390.c", "__ei_tx_timeout"],
["drivers/net/ethernet/8390/lib8390.c", "__ei_tx_timeout"],
["drivers/net/ethernet/8390/ne2k-pci.c", "ei_tx_timeout"],
["drivers/net/ethernet/8390/pcnet_cs.c", "ei_tx_timeout"],
["drivers/net/ethernet/8390/smc-ultra.c", "ei_tx_timeout"],
["drivers/net/ethernet/8390/wd.c", "ei_tx_timeout"],
["drivers/net/ethernet/8390/zorro8390.c", "__ei_tx_timeout"],
["drivers/net/ethernet/adaptec/starfire.c", "tx_timeout"],
["drivers/net/ethernet/agere/et131x.c", "et131x_tx_timeout"],
["drivers/net/ethernet/allwinner/sun4i-emac.c", "emac_timeout"],
["drivers/net/ethernet/alteon/acenic.c", "ace_watchdog"],
["drivers/net/ethernet/amazon/ena/ena_netdev.c", "ena_tx_timeout"],
["drivers/net/ethernet/amd/7990.h", "lance_tx_timeout"],
["drivers/net/ethernet/amd/7990.c", "lance_tx_timeout"],
["drivers/net/ethernet/amd/a2065.c", "lance_tx_timeout"],
["drivers/net/ethernet/amd/am79c961a.c", "am79c961_timeout"],
["drivers/net/ethernet/amd/amd8111e.c", "amd8111e_tx_timeout"],
["drivers/net/ethernet/amd/ariadne.c", "ariadne_tx_timeout"],
["drivers/net/ethernet/amd/atarilance.c", "lance_tx_timeout"],
["drivers/net/ethernet/amd/au1000_eth.c", "au1000_tx_timeout"],
["drivers/net/ethernet/amd/declance.c", "lance_tx_timeout"],
["drivers/net/ethernet/amd/lance.c", "lance_tx_timeout"],
["drivers/net/ethernet/amd/mvme147.c", "lance_tx_timeout"],
["drivers/net/ethernet/amd/ni65.c", "ni65_timeout"],
["drivers/net/ethernet/amd/nmclan_cs.c", "mace_tx_timeout"],
["drivers/net/ethernet/amd/pcnet32.c", "pcnet32_tx_timeout"],
["drivers/net/ethernet/amd/sunlance.c", "lance_tx_timeout"],
["drivers/net/ethernet/amd/xgbe/xgbe-drv.c", "xgbe_tx_timeout"],
["drivers/net/ethernet/apm/xgene-v2/main.c", "xge_timeout"],
["drivers/net/ethernet/apm/xgene/xgene_enet_main.c", "xgene_enet_timeout"],
["drivers/net/ethernet/apple/macmace.c", "mace_tx_timeout"],
["drivers/net/ethernet/atheros/ag71xx.c", "ag71xx_tx_timeout"],
["drivers/net/ethernet/atheros/alx/main.c", "alx_tx_timeout"],
["drivers/net/ethernet/atheros/atl1c/atl1c_main.c", "atl1c_tx_timeout"],
["drivers/net/ethernet/atheros/atl1e/atl1e_main.c", "atl1e_tx_timeout"],
["drivers/net/ethernet/atheros/atlx/atl.c", "atlx_tx_timeout"],
["drivers/net/ethernet/atheros/atlx/atl1.c", "atlx_tx_timeout"],
["drivers/net/ethernet/atheros/atlx/atl2.c", "atl2_tx_timeout"],
["drivers/net/ethernet/broadcom/b44.c", "b44_tx_timeout"],
["drivers/net/ethernet/broadcom/bcmsysport.c", "bcm_sysport_tx_timeout"],
["drivers/net/ethernet/broadcom/bnx2.c", "bnx2_tx_timeout"],
["drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h", "bnx2x_tx_timeout"],
["drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c", "bnx2x_tx_timeout"],
["drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c", "bnx2x_tx_timeout"],
["drivers/net/ethernet/broadcom/bnxt/bnxt.c", "bnxt_tx_timeout"],
["drivers/net/ethernet/broadcom/genet/bcmgenet.c", "bcmgenet_timeout"],
["drivers/net/ethernet/broadcom/sb1250-mac.c", "sbmac_tx_timeout"],
["drivers/net/ethernet/broadcom/tg3.c", "tg3_tx_timeout"],
["drivers/net/ethernet/calxeda/xgmac.c", "xgmac_tx_timeout"],
["drivers/net/ethernet/cavium/liquidio/lio_main.c", "liquidio_tx_timeout"],
["drivers/net/ethernet/cavium/liquidio/lio_vf_main.c", "liquidio_tx_timeout"],
["drivers/net/ethernet/cavium/liquidio/lio_vf_rep.c", "lio_vf_rep_tx_timeout"],
["drivers/net/ethernet/cavium/thunder/nicvf_main.c", "nicvf_tx_timeout"],
["drivers/net/ethernet/cirrus/cs89x0.c", "net_timeout"],
["drivers/net/ethernet/cisco/enic/enic_main.c", "enic_tx_timeout"],
["drivers/net/ethernet/cisco/enic/enic_main.c", "enic_tx_timeout"],
["drivers/net/ethernet/cortina/gemini.c", "gmac_tx_timeout"],
["drivers/net/ethernet/davicom/dm9000.c", "dm9000_timeout"],
["drivers/net/ethernet/dec/tulip/de2104x.c", "de_tx_timeout"],
["drivers/net/ethernet/dec/tulip/tulip_core.c", "tulip_tx_timeout"],
["drivers/net/ethernet/dec/tulip/winbond-840.c", "tx_timeout"],
["drivers/net/ethernet/dlink/dl2k.c", "rio_tx_timeout"],
["drivers/net/ethernet/dlink/sundance.c", "tx_timeout"],
["drivers/net/ethernet/emulex/benet/be_main.c", "be_tx_timeout"],
["drivers/net/ethernet/ethoc.c", "ethoc_tx_timeout"],
["drivers/net/ethernet/faraday/ftgmac100.c", "ftgmac100_tx_timeout"],
["drivers/net/ethernet/fealnx.c", "fealnx_tx_timeout"],
["drivers/net/ethernet/freescale/dpaa/dpaa_eth.c", "dpaa_tx_timeout"],
["drivers/net/ethernet/freescale/fec_main.c", "fec_timeout"],
["drivers/net/ethernet/freescale/fec_mpc52xx.c", "mpc52xx_fec_tx_timeout"],
["drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c", "fs_timeout"],
["drivers/net/ethernet/freescale/gianfar.c", "gfar_timeout"],
["drivers/net/ethernet/freescale/ucc_geth.c", "ucc_geth_timeout"],
["drivers/net/ethernet/fujitsu/fmvj18x_cs.c", "fjn_tx_timeout"],
["drivers/net/ethernet/google/gve/gve_main.c", "gve_tx_timeout"],
["drivers/net/ethernet/hisilicon/hip04_eth.c", "hip04_timeout"],
["drivers/net/ethernet/hisilicon/hix5hd2_gmac.c", "hix5hd2_net_timeout"],
["drivers/net/ethernet/hisilicon/hns/hns_enet.c", "hns_nic_net_timeout"],
["drivers/net/ethernet/hisilicon/hns3/hns3_enet.c", "hns3_nic_net_timeout"],
["drivers/net/ethernet/huawei/hinic/hinic_main.c", "hinic_tx_timeout"],
["drivers/net/ethernet/i825xx/82596.c", "i596_tx_timeout"],
["drivers/net/ethernet/i825xx/ether1.c", "ether1_timeout"],
["drivers/net/ethernet/i825xx/lib82596.c", "i596_tx_timeout"],
["drivers/net/ethernet/i825xx/sun3_82586.c", "sun3_82586_timeout"],
["drivers/net/ethernet/ibm/ehea/ehea_main.c", "ehea_tx_watchdog"],
["drivers/net/ethernet/ibm/emac/core.c", "emac_tx_timeout"],
["drivers/net/ethernet/ibm/emac/core.c", "emac_tx_timeout"],
["drivers/net/ethernet/ibm/ibmvnic.c", "ibmvnic_tx_timeout"],
["drivers/net/ethernet/intel/e100.c", "e100_tx_timeout"],
["drivers/net/ethernet/intel/e1000/e1000_main.c", "e1000_tx_timeout"],
["drivers/net/ethernet/intel/e1000e/netdev.c", "e1000_tx_timeout"],
["drivers/net/ethernet/intel/fm10k/fm10k_netdev.c", "fm10k_tx_timeout"],
["drivers/net/ethernet/intel/i40e/i40e_main.c", "i40e_tx_timeout"],
["drivers/net/ethernet/intel/iavf/iavf_main.c", "iavf_tx_timeout"],
["drivers/net/ethernet/intel/ice/ice_main.c", "ice_tx_timeout"],
["drivers/net/ethernet/intel/ice/ice_main.c", "ice_tx_timeout"],
["drivers/net/ethernet/intel/igb/igb_main.c", "igb_tx_timeout"],
["drivers/net/ethernet/intel/igbvf/netdev.c", "igbvf_tx_timeout"],
["drivers/net/ethernet/intel/ixgb/ixgb_main.c", "ixgb_tx_timeout"],
["drivers/net/ethernet/intel/ixgbe/ixgbe_debugfs.c", "adapter->netdev->netdev_ops->ndo_tx_timeout(adapter->netdev);"],
["drivers/net/ethernet/intel/ixgbe/ixgbe_main.c", "ixgbe_tx_timeout"],
["drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c", "ixgbevf_tx_timeout"],
["drivers/net/ethernet/jme.c", "jme_tx_timeout"],
["drivers/net/ethernet/korina.c", "korina_tx_timeout"],
["drivers/net/ethernet/lantiq_etop.c", "ltq_etop_tx_timeout"],
["drivers/net/ethernet/marvell/mv643xx_eth.c", "mv643xx_eth_tx_timeout"],
["drivers/net/ethernet/marvell/pxa168_eth.c", "pxa168_eth_tx_timeout"],
["drivers/net/ethernet/marvell/skge.c", "skge_tx_timeout"],
["drivers/net/ethernet/marvell/sky2.c", "sky2_tx_timeout"],
["drivers/net/ethernet/marvell/sky2.c", "sky2_tx_timeout"],
["drivers/net/ethernet/mediatek/mtk_eth_soc.c", "mtk_tx_timeout"],
["drivers/net/ethernet/mellanox/mlx4/en_netdev.c", "mlx4_en_tx_timeout"],
["drivers/net/ethernet/mellanox/mlx4/en_netdev.c", "mlx4_en_tx_timeout"],
["drivers/net/ethernet/mellanox/mlx5/core/en_main.c", "mlx5e_tx_timeout"],
["drivers/net/ethernet/micrel/ks8842.c", "ks8842_tx_timeout"],
["drivers/net/ethernet/micrel/ksz884x.c", "netdev_tx_timeout"],
["drivers/net/ethernet/microchip/enc28j60.c", "enc28j60_tx_timeout"],
["drivers/net/ethernet/microchip/encx24j600.c", "encx24j600_tx_timeout"],
["drivers/net/ethernet/natsemi/sonic.h", "sonic_tx_timeout"],
["drivers/net/ethernet/natsemi/sonic.c", "sonic_tx_timeout"],
["drivers/net/ethernet/natsemi/jazzsonic.c", "sonic_tx_timeout"],
["drivers/net/ethernet/natsemi/macsonic.c", "sonic_tx_timeout"],
["drivers/net/ethernet/natsemi/natsemi.c", "ns_tx_timeout"],
["drivers/net/ethernet/natsemi/ns83820.c", "ns83820_tx_timeout"],
["drivers/net/ethernet/natsemi/xtsonic.c", "sonic_tx_timeout"],
["drivers/net/ethernet/neterion/s2io.h", "s2io_tx_watchdog"],
["drivers/net/ethernet/neterion/s2io.c", "s2io_tx_watchdog"],
["drivers/net/ethernet/neterion/vxge/vxge-main.c", "vxge_tx_watchdog"],
["drivers/net/ethernet/netronome/nfp/nfp_net_common.c", "nfp_net_tx_timeout"],
["drivers/net/ethernet/nvidia/forcedeth.c", "nv_tx_timeout"],
["drivers/net/ethernet/nvidia/forcedeth.c", "nv_tx_timeout"],
["drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c", "pch_gbe_tx_timeout"],
["drivers/net/ethernet/packetengines/hamachi.c", "hamachi_tx_timeout"],
["drivers/net/ethernet/packetengines/yellowfin.c", "yellowfin_tx_timeout"],
["drivers/net/ethernet/pensando/ionic/ionic_lif.c", "ionic_tx_timeout"],
["drivers/net/ethernet/qlogic/netxen/netxen_nic_main.c", "netxen_tx_timeout"],
["drivers/net/ethernet/qlogic/qla3xxx.c", "ql3xxx_tx_timeout"],
["drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c", "qlcnic_tx_timeout"],
["drivers/net/ethernet/qualcomm/emac/emac.c", "emac_tx_timeout"],
["drivers/net/ethernet/qualcomm/qca_spi.c", "qcaspi_netdev_tx_timeout"],
["drivers/net/ethernet/qualcomm/qca_uart.c", "qcauart_netdev_tx_timeout"],
["drivers/net/ethernet/rdc/r6040.c", "r6040_tx_timeout"],
["drivers/net/ethernet/realtek/8139cp.c", "cp_tx_timeout"],
["drivers/net/ethernet/realtek/8139too.c", "rtl8139_tx_timeout"],
["drivers/net/ethernet/realtek/atp.c", "tx_timeout"],
["drivers/net/ethernet/realtek/r8169_main.c", "rtl8169_tx_timeout"],
["drivers/net/ethernet/renesas/ravb_main.c", "ravb_tx_timeout"],
["drivers/net/ethernet/renesas/sh_eth.c", "sh_eth_tx_timeout"],
["drivers/net/ethernet/renesas/sh_eth.c", "sh_eth_tx_timeout"],
["drivers/net/ethernet/samsung/sxgbe/sxgbe_main.c", "sxgbe_tx_timeout"],
["drivers/net/ethernet/seeq/ether3.c", "ether3_timeout"],
["drivers/net/ethernet/seeq/sgiseeq.c", "timeout"],
["drivers/net/ethernet/sfc/efx.c", "efx_watchdog"],
["drivers/net/ethernet/sfc/falcon/efx.c", "ef4_watchdog"],
["drivers/net/ethernet/sgi/ioc3-eth.c", "ioc3_timeout"],
["drivers/net/ethernet/sgi/meth.c", "meth_tx_timeout"],
["drivers/net/ethernet/silan/sc92031.c", "sc92031_tx_timeout"],
["drivers/net/ethernet/sis/sis190.c", "sis190_tx_timeout"],
["drivers/net/ethernet/sis/sis900.c", "sis900_tx_timeout"],
["drivers/net/ethernet/smsc/epic100.c", "epic_tx_timeout"],
["drivers/net/ethernet/smsc/smc911x.c", "smc911x_timeout"],
["drivers/net/ethernet/smsc/smc9194.c", "smc_timeout"],
["drivers/net/ethernet/smsc/smc91c92_cs.c", "smc_tx_timeout"],
["drivers/net/ethernet/smsc/smc91x.c", "smc_timeout"],
["drivers/net/ethernet/stmicro/stmmac/stmmac_main.c", "stmmac_tx_timeout"],
["drivers/net/ethernet/sun/cassini.c", "cas_tx_timeout"],
["drivers/net/ethernet/sun/ldmvsw.c", "sunvnet_tx_timeout_common"],
["drivers/net/ethernet/sun/niu.c", "niu_tx_timeout"],
["drivers/net/ethernet/sun/sunbmac.c", "bigmac_tx_timeout"],
["drivers/net/ethernet/sun/sungem.c", "gem_tx_timeout"],
["drivers/net/ethernet/sun/sunhme.c", "happy_meal_tx_timeout"],
["drivers/net/ethernet/sun/sunqe.c", "qe_tx_timeout"],
["drivers/net/ethernet/sun/sunvnet.c", "sunvnet_tx_timeout_common"],
["drivers/net/ethernet/sun/sunvnet_common.c", "sunvnet_tx_timeout_common"],
["drivers/net/ethernet/sun/sunvnet_common.h", "sunvnet_tx_timeout_common"],
["drivers/net/ethernet/synopsys/dwc-xlgmac-net.c", "xlgmac_tx_timeout"],
["drivers/net/ethernet/ti/cpmac.c", "cpmac_tx_timeout"],
["drivers/net/ethernet/ti/cpsw.c", "cpsw_ndo_tx_timeout"],
["drivers/net/ethernet/ti/cpsw_priv.c", "cpsw_ndo_tx_timeout"],
["drivers/net/ethernet/ti/cpsw_priv.h", "cpsw_ndo_tx_timeout"],
["drivers/net/ethernet/ti/davinci_emac.c", "emac_dev_tx_timeout"],
["drivers/net/ethernet/ti/netcp_core.c", "netcp_ndo_tx_timeout"],
["drivers/net/ethernet/ti/tlan.c", "tlan_tx_timeout"],
["drivers/net/ethernet/toshiba/ps3_gelic_net.h", "gelic_net_tx_timeout"],
["drivers/net/ethernet/toshiba/ps3_gelic_net.c", "gelic_net_tx_timeout"],
["drivers/net/ethernet/toshiba/ps3_gelic_wireless.c", "gelic_net_tx_timeout"],
["drivers/net/ethernet/toshiba/spider_net.c", "spider_net_tx_timeout"],
["drivers/net/ethernet/toshiba/tc35815.c", "tc35815_tx_timeout"],
["drivers/net/ethernet/via/via-rhine.c", "rhine_tx_timeout"],
["drivers/net/ethernet/wiznet/w5100.c", "w5100_tx_timeout"],
["drivers/net/ethernet/wiznet/w5300.c", "w5300_tx_timeout"],
["drivers/net/ethernet/xilinx/xilinx_emaclite.c", "xemaclite_tx_timeout"],
["drivers/net/ethernet/xircom/xirc2ps_cs.c", "xirc_tx_timeout"],
["drivers/net/fjes/fjes_main.c", "fjes_tx_retry"],
["drivers/net/slip/slip.c", "sl_tx_timeout"],
["include/linux/usb/usbnet.h", "usbnet_tx_timeout"],
["drivers/net/usb/aqc111.c", "usbnet_tx_timeout"],
["drivers/net/usb/asix_devices.c", "usbnet_tx_timeout"],
["drivers/net/usb/asix_devices.c", "usbnet_tx_timeout"],
["drivers/net/usb/asix_devices.c", "usbnet_tx_timeout"],
["drivers/net/usb/ax88172a.c", "usbnet_tx_timeout"],
["drivers/net/usb/ax88179_178a.c", "usbnet_tx_timeout"],
["drivers/net/usb/catc.c", "catc_tx_timeout"],
["drivers/net/usb/cdc_mbim.c", "usbnet_tx_timeout"],
["drivers/net/usb/cdc_ncm.c", "usbnet_tx_timeout"],
["drivers/net/usb/dm9601.c", "usbnet_tx_timeout"],
["drivers/net/usb/hso.c", "hso_net_tx_timeout"],
["drivers/net/usb/int51x1.c", "usbnet_tx_timeout"],
["drivers/net/usb/ipheth.c", "ipheth_tx_timeout"],
["drivers/net/usb/kaweth.c", "kaweth_tx_timeout"],
["drivers/net/usb/lan78xx.c", "lan78xx_tx_timeout"],
["drivers/net/usb/mcs7830.c", "usbnet_tx_timeout"],
["drivers/net/usb/pegasus.c", "pegasus_tx_timeout"],
["drivers/net/usb/qmi_wwan.c", "usbnet_tx_timeout"],
["drivers/net/usb/r8152.c", "rtl8152_tx_timeout"],
["drivers/net/usb/rndis_host.c", "usbnet_tx_timeout"],
["drivers/net/usb/rtl8150.c", "rtl8150_tx_timeout"],
["drivers/net/usb/sierra_net.c", "usbnet_tx_timeout"],
["drivers/net/usb/smsc75xx.c", "usbnet_tx_timeout"],
["drivers/net/usb/smsc95xx.c", "usbnet_tx_timeout"],
["drivers/net/usb/sr9700.c", "usbnet_tx_timeout"],
["drivers/net/usb/sr9800.c", "usbnet_tx_timeout"],
["drivers/net/usb/usbnet.c", "usbnet_tx_timeout"],
["drivers/net/vmxnet3/vmxnet3_drv.c", "vmxnet3_tx_timeout"],
["drivers/net/wan/cosa.c", "cosa_net_timeout"],
["drivers/net/wan/farsync.c", "fst_tx_timeout"],
["drivers/net/wan/fsl_ucc_hdlc.c", "uhdlc_tx_timeout"],
["drivers/net/wan/lmc/lmc_main.c", "lmc_driver_timeout"],
["drivers/net/wan/x25_asy.c", "x25_asy_timeout"],
["drivers/net/wimax/i2400m/netdev.c", "i2400m_tx_timeout"],
["drivers/net/wireless/intel/ipw2x00/ipw2100.c", "ipw2100_tx_timeout"],
["drivers/net/wireless/intersil/hostap/hostap_main.c", "prism2_tx_timeout"],
["drivers/net/wireless/intersil/hostap/hostap_main.c", "prism2_tx_timeout"],
["drivers/net/wireless/intersil/hostap/hostap_main.c", "prism2_tx_timeout"],
["drivers/net/wireless/intersil/orinoco/main.c", "orinoco_tx_timeout"],
["drivers/net/wireless/intersil/orinoco/orinoco_usb.c", "orinoco_tx_timeout"],
["drivers/net/wireless/intersil/orinoco/orinoco.h", "orinoco_tx_timeout"],
["drivers/net/wireless/intersil/prism54/islpci_dev.c", "islpci_eth_tx_timeout"],
["drivers/net/wireless/intersil/prism54/islpci_eth.c", "islpci_eth_tx_timeout"],
["drivers/net/wireless/intersil/prism54/islpci_eth.h", "islpci_eth_tx_timeout"],
["drivers/net/wireless/marvell/mwifiex/main.c", "mwifiex_tx_timeout"],
["drivers/net/wireless/quantenna/qtnfmac/core.c", "qtnf_netdev_tx_timeout"],
["drivers/net/wireless/quantenna/qtnfmac/core.h", "qtnf_netdev_tx_timeout"],
["drivers/net/wireless/rndis_wlan.c", "usbnet_tx_timeout"],
["drivers/net/wireless/wl3501_cs.c", "wl3501_tx_timeout"],
["drivers/net/wireless/zydas/zd1201.c", "zd1201_tx_timeout"],
["drivers/s390/net/qeth_core.h", "qeth_tx_timeout"],
["drivers/s390/net/qeth_core_main.c", "qeth_tx_timeout"],
["drivers/s390/net/qeth_l2_main.c", "qeth_tx_timeout"],
["drivers/s390/net/qeth_l2_main.c", "qeth_tx_timeout"],
["drivers/s390/net/qeth_l3_main.c", "qeth_tx_timeout"],
["drivers/s390/net/qeth_l3_main.c", "qeth_tx_timeout"],
["drivers/staging/ks7010/ks_wlan_net.c", "ks_wlan_tx_timeout"],
["drivers/staging/qlge/qlge_main.c", "qlge_tx_timeout"],
["drivers/staging/rtl8192e/rtl8192e/rtl_core.c", "_rtl92e_tx_timeout"],
["drivers/staging/rtl8192u/r8192U_core.c", "tx_timeout"],
["drivers/staging/unisys/visornic/visornic_main.c", "visornic_xmit_timeout"],
["drivers/staging/wlan-ng/p80211netdev.c", "p80211knetdev_tx_timeout"],
["drivers/tty/n_gsm.c", "gsm_mux_net_tx_timeout"],
["drivers/tty/synclink.c", "hdlcdev_tx_timeout"],
["drivers/tty/synclink_gt.c", "hdlcdev_tx_timeout"],
["drivers/tty/synclinkmp.c", "hdlcdev_tx_timeout"],
["net/atm/lec.c", "lec_tx_timeout"],
["net/bluetooth/bnep/netdev.c", "bnep_net_timeout"]
);

for my $p (@work) {
	my @pair = @$p;
	my $file = $pair[0];
	my $func = $pair[1];
	print STDERR $file , ": ", $func,"\n";
	our @ARGV = ($file);
	while (<ARGV>) {
		if (m/($func\s*\(struct\s+net_device\s+\*[A-Za-z_]?[A-Za-z-0-9_]*)(\))/) {
			print STDERR "found $1+$2 in $file\n";
		}
		if (s/($func\s*\(struct\s+net_device\s+\*[A-Za-z_]?[A-Za-z-0-9_]*)(\))/$1, unsigned int txqueue$2/) {
			print STDERR "$func found in $file\n";
		}
		print;
	}
}

where the list of files and functions is simply from:

git grep ndo_tx_timeout, with manual addition of headers
in the rare cases where the function is from a header,
then manually changing the few places which actually
call ndo_tx_timeout.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Heiner Kallweit <hkallweit1@gmail.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Shannon Nelson <snelson@pensando.io>
Reviewed-by: Martin Habets <mhabets@solarflare.com>

changes from v9:
	fixup a forward declaration
changes from v9:
	more leftovers from v3 change
changes from v8:
        fix up a missing direct call to timeout
        rebased on net-next
changes from v7:
	fixup leftovers from v3 change
changes from v6:
	fix typo in rtl driver
changes from v5:
	add missing files (allow any net device argument name)
changes from v4:
	add a missing driver header
changes from v3:
        change queue # to unsigned
Changes from v2:
        added headers
Changes from v1:
        Fix errors found by kbuild:
        generalize the pattern a bit, to pick up
        a couple of instances missed by the previous
        version.

Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-12-12 21:38:57 -08:00
Eric Dumazet 90b2be27bb net/sched: annotate lockless accesses to qdisc->empty 
KCSAN reported the following race [1]

BUG: KCSAN: data-race in __dev_queue_xmit / net_tx_action

read to 0xffff8880ba403508 of 1 bytes by task 21814 on cpu 1:
 __dev_xmit_skb net/core/dev.c:3389 [inline]
 __dev_queue_xmit+0x9db/0x1b40 net/core/dev.c:3761
 dev_queue_xmit+0x21/0x30 net/core/dev.c:3825
 neigh_hh_output include/net/neighbour.h:500 [inline]
 neigh_output include/net/neighbour.h:509 [inline]
 ip6_finish_output2+0x873/0xec0 net/ipv6/ip6_output.c:116
 __ip6_finish_output net/ipv6/ip6_output.c:142 [inline]
 __ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127
 ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 ip6_local_out+0x74/0x90 net/ipv6/output_core.c:179
 ip6_send_skb+0x53/0x110 net/ipv6/ip6_output.c:1795
 udp_v6_send_skb.isra.0+0x3ec/0xa70 net/ipv6/udp.c:1173
 udpv6_sendmsg+0x1906/0x1c20 net/ipv6/udp.c:1471
 inet6_sendmsg+0x6d/0x90 net/ipv6/af_inet6.c:576
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0x9f/0xc0 net/socket.c:657
 ___sys_sendmsg+0x2b7/0x5d0 net/socket.c:2311
 __sys_sendmmsg+0x123/0x350 net/socket.c:2413
 __do_sys_sendmmsg net/socket.c:2442 [inline]
 __se_sys_sendmmsg net/socket.c:2439 [inline]
 __x64_sys_sendmmsg+0x64/0x80 net/socket.c:2439
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8880ba403508 of 1 bytes by interrupt on cpu 0:
 qdisc_run_begin include/net/sch_generic.h:160 [inline]
 qdisc_run include/net/pkt_sched.h:120 [inline]
 net_tx_action+0x2b1/0x6c0 net/core/dev.c:4551
 __do_softirq+0x115/0x33f kernel/softirq.c:292
 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1082
 do_softirq.part.0+0x6b/0x80 kernel/softirq.c:337
 do_softirq kernel/softirq.c:329 [inline]
 __local_bh_enable_ip+0x76/0x80 kernel/softirq.c:189
 local_bh_enable include/linux/bottom_half.h:32 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:688 [inline]
 ip6_finish_output2+0x7bb/0xec0 net/ipv6/ip6_output.c:117
 __ip6_finish_output net/ipv6/ip6_output.c:142 [inline]
 __ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127
 ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 ip6_local_out+0x74/0x90 net/ipv6/output_core.c:179
 ip6_send_skb+0x53/0x110 net/ipv6/ip6_output.c:1795
 udp_v6_send_skb.isra.0+0x3ec/0xa70 net/ipv6/udp.c:1173
 udpv6_sendmsg+0x1906/0x1c20 net/ipv6/udp.c:1471
 inet6_sendmsg+0x6d/0x90 net/ipv6/af_inet6.c:576
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0x9f/0xc0 net/socket.c:657
 ___sys_sendmsg+0x2b7/0x5d0 net/socket.c:2311
 __sys_sendmmsg+0x123/0x350 net/socket.c:2413
 __do_sys_sendmmsg net/socket.c:2442 [inline]
 __se_sys_sendmmsg net/socket.c:2439 [inline]
 __x64_sys_sendmmsg+0x64/0x80 net/socket.c:2439
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 21817 Comm: syz-executor.2 Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: d518d2ed86 ("net/sched: fix race between deactivation and dequeue for NOLOCK qdisc")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-11-08 12:21:55 -08:00
David S. Miller d31e95585c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 
The only slightly tricky merge conflict was the netdevsim because the
mutex locking fix overlapped a lot of driver reload reorganization.

The rest were (relatively) trivial in nature.

Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-11-02 13:54:56 -07:00
Vincent Prince 546b85bb0a net: sch_generic: Use pfifo_fast as fallback scheduler for CAN hardware 
There is networking hardware that isn't based on Ethernet for layers 1 and 2.

For example CAN.

CAN is a multi-master serial bus standard for connecting Electronic Control
Units [ECUs] also known as nodes. A frame on the CAN bus carries up to 8 bytes
of payload. Frame corruption is detected by a CRC. However frame loss due to
corruption is possible, but a quite unusual phenomenon.

While fq_codel works great for TCP/IP, it doesn't for CAN. There are a lot of
legacy protocols on top of CAN, which are not build with flow control or high
CAN frame drop rates in mind.

When using fq_codel, as soon as the queue reaches a certain delay based length,
skbs from the head of the queue are silently dropped. Silently meaning that the
user space using a send() or similar syscall doesn't get an error. However
TCP's flow control algorithm will detect dropped packages and adjust the
bandwidth accordingly.

When using fq_codel and sending raw frames over CAN, which is the common use
case, the user space thinks the package has been sent without problems, because
send() returned without an error. pfifo_fast will drop skbs, if the queue
length exceeds the maximum. But with this scheduler the skbs at the tail are
dropped, an error (-ENOBUFS) is propagated to user space. So that the user
space can slow down the package generation.

On distributions, where fq_codel is made default via CONFIG_DEFAULT_NET_SCH
during compile time, or set default during runtime with sysctl
net.core.default_qdisc (see [1]), we get a bad user experience. In my test case
with pfifo_fast, I can transfer thousands of million CAN frames without a frame
drop. On the other hand with fq_codel there is more then one lost CAN frame per
thousand frames.

As pointed out fq_codel is not suited for CAN hardware, so this patch changes
attach_one_default_qdisc() to use pfifo_fast for "ARPHRD_CAN" network devices.

During transition of a netdev from down to up state the default queuing
discipline is attached by attach_default_qdiscs() with the help of
attach_one_default_qdisc(). This patch modifies attach_one_default_qdisc() to
attach the pfifo_fast (pfifo_fast_ops) if the network device type is
"ARPHRD_CAN".

[1] https://github.com/systemd/systemd/issues/9194

Suggested-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Vincent Prince <vincent.prince.fr@gmail.com>
Acked-by: Dave Taht <dave.taht@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-10-25 19:19:51 -07:00
Vincent Prince fa784f2ac0 net: sch_generic: Use pfifo_fast as fallback scheduler for CAN hardware 
There is networking hardware that isn't based on Ethernet for layers 1 and 2.

For example CAN.

CAN is a multi-master serial bus standard for connecting Electronic Control
Units [ECUs] also known as nodes. A frame on the CAN bus carries up to 8 bytes
of payload. Frame corruption is detected by a CRC. However frame loss due to
corruption is possible, but a quite unusual phenomenon.

While fq_codel works great for TCP/IP, it doesn't for CAN. There are a lot of
legacy protocols on top of CAN, which are not build with flow control or high
CAN frame drop rates in mind.

When using fq_codel, as soon as the queue reaches a certain delay based length,
skbs from the head of the queue are silently dropped. Silently meaning that the
user space using a send() or similar syscall doesn't get an error. However
TCP's flow control algorithm will detect dropped packages and adjust the
bandwidth accordingly.

When using fq_codel and sending raw frames over CAN, which is the common use
case, the user space thinks the package has been sent without problems, because
send() returned without an error. pfifo_fast will drop skbs, if the queue
length exceeds the maximum. But with this scheduler the skbs at the tail are
dropped, an error (-ENOBUFS) is propagated to user space. So that the user
space can slow down the package generation.

On distributions, where fq_codel is made default via CONFIG_DEFAULT_NET_SCH
during compile time, or set default during runtime with sysctl
net.core.default_qdisc (see [1]), we get a bad user experience. In my test case
with pfifo_fast, I can transfer thousands of million CAN frames without a frame
drop. On the other hand with fq_codel there is more then one lost CAN frame per
thousand frames.

As pointed out fq_codel is not suited for CAN hardware, so this patch changes
attach_one_default_qdisc() to use pfifo_fast for "ARPHRD_CAN" network devices.

During transition of a netdev from down to up state the default queuing
discipline is attached by attach_default_qdiscs() with the help of
attach_one_default_qdisc(). This patch modifies attach_one_default_qdisc() to
attach the pfifo_fast (pfifo_fast_ops) if the network device type is
"ARPHRD_CAN".

[1] https://github.com/systemd/systemd/issues/9194

Signed-off-by: Vincent Prince <vincent.prince.fr@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-10-25 16:14:05 -07:00
Taehee Yoo ab92d68fc2 net: core: add generic lockdep keys 
Some interface types could be nested.
(VLAN, BONDING, TEAM, MACSEC, MACVLAN, IPVLAN, VIRT_WIFI, VXLAN, etc..)
These interface types should set lockdep class because, without lockdep
class key, lockdep always warn about unexisting circular locking.

In the current code, these interfaces have their own lockdep class keys and
these manage itself. So that there are so many duplicate code around the
/driver/net and /net/.
This patch adds new generic lockdep keys and some helper functions for it.

This patch does below changes.
a) Add lockdep class keys in struct net_device
   - qdisc_running, xmit, addr_list, qdisc_busylock
   - these keys are used as dynamic lockdep key.
b) When net_device is being allocated, lockdep keys are registered.
   - alloc_netdev_mqs()
c) When net_device is being free'd llockdep keys are unregistered.
   - free_netdev()
d) Add generic lockdep key helper function
   - netdev_register_lockdep_key()
   - netdev_unregister_lockdep_key()
   - netdev_update_lockdep_key()
e) Remove unnecessary generic lockdep macro and functions
f) Remove unnecessary lockdep code of each interfaces.

After this patch, each interface modules don't need to maintain
their lockdep keys.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-10-24 14:53:48 -07:00
Marc Kleine-Budde 4eab421bc3 net: sched: Avoid using yield() in a busy waiting loop 
With threaded interrupts enabled, the interrupt thread runs as SCHED_RR
with priority 50. If a user application with a higher priority preempts
the interrupt thread and tries to shutdown the network interface then it
will loop forever. The kernel will spin in the loop waiting for the
device to become idle and the scheduler will never consider the
interrupt thread because its priority is lower.

Avoid the problem by sleeping for a jiffy giving other tasks,
including the interrupt thread, a chance to run and make progress.

In the original thread it has been suggested to use wait_event() and
properly waiting for the state to occur. DaveM explained that this would
require to add expensive checks in the fast paths of packet processing.

Link: https://lkml.kernel.org/r/1393976987-23555-1-git-send-email-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
[bigeasy: Rewrite commit message, add comment, use
          schedule_timeout_uninterruptible()]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-10-17 15:33:03 -04:00
Eric Dumazet b60fa1c5d0 net_sched: remove need_resched() from qdisc_run() 
The introduction of this schedule point was done in commit
2ba2506ca7 ("[NET]: Add preemption point in qdisc_run")
at a time the loop was not bounded.

Then later in commit d5b8aa1d24 ("net_sched: fix dequeuer fairness")
we added a limit on the number of packets.

Now is the time to remove the schedule point, since the default
limit of 64 packets matches the number of packets a typical NAPI
poll can process in a row.

This solves a latency problem for most TCP receivers under moderate load :

1) host receives a packet.
   NET_RX_SOFTIRQ is raised by NIC hard IRQ handler

2) __do_softirq() does its first loop, handling NET_RX_SOFTIRQ
   and calling the driver napi->loop() function

3) TCP stores the skb in socket receive queue:

4) TCP calls sk->sk_data_ready() and wakeups a user thread
   waiting for EPOLLIN (as a result, need_resched() might now be true)

5) TCP cooks an ACK and sends it.

6) qdisc_run() processes one packet from qdisc, and sees need_resched(),
   this raises NET_TX_SOFTIRQ (even if there are no more packets in
   the qdisc)

Then we go back to the __do_softirq() in 2), and we see that new
softirqs were raised. Since need_resched() is true, we end up waking
ksoftirqd in this path :

    if (pending) {
            if (time_before(jiffies, end) && !need_resched() &&
                --max_restart)
                    goto restart;

            wakeup_softirqd();
    }

So we have many wakeups of ksoftirqd kernel threads,
and more calls to qdisc_run() with associated lock overhead.

Note that another way to solve the issue would be to change TCP
to first send the ACK packet, then signal the EPOLLIN,
but this changes P99 latencies, as sending the ACK packet
can add a long delay.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-10-02 14:26:33 -07:00
Cong Wang 6efb971ba8 net_sched: let qdisc_put() accept NULL pointer 
When tcf_block_get() fails in sfb_init(), q->qdisc is still a NULL
pointer which leads to a crash in sfb_destroy(). Similar for
sch_dsmark.

Instead of fixing each separately, Linus suggested to just accept
NULL pointer in qdisc_put(), which would make callers easier.

(For sch_dsmark, the bug probably exists long before commit
6529eaba33f0.)

Fixes: 6529eaba33 ("net: sched: introduce tcf block infractructure")
Reported-by: syzbot+d5870a903591faaca4ae@syzkaller.appspotmail.com
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-09-15 20:54:14 +02:00
Eric Dumazet b88dd52c62 net: sched: fix reordering issues 
Whenever MQ is not used on a multiqueue device, we experience
serious reordering problems. Bisection found the cited
commit.

The issue can be described this way :

- A single qdisc hierarchy is shared by all transmit queues.
  (eg : tc qdisc replace dev eth0 root fq_codel)

- When/if try_bulk_dequeue_skb_slow() dequeues a packet targetting
  a different transmit queue than the one used to build a packet train,
  we stop building the current list and save the 'bad' skb (P1) in a
  special queue. (bad_txq)

- When dequeue_skb() calls qdisc_dequeue_skb_bad_txq() and finds this
  skb (P1), it checks if the associated transmit queues is still in frozen
  state. If the queue is still blocked (by BQL or NIC tx ring full),
  we leave the skb in bad_txq and return NULL.

- dequeue_skb() calls q->dequeue() to get another packet (P2)

  The other packet can target the problematic queue (that we found
  in frozen state for the bad_txq packet), but another cpu just ran
  TX completion and made room in the txq that is now ready to accept
  new packets.

- Packet P2 is sent while P1 is still held in bad_txq, P1 might be sent
  at next round. In practice P2 is the lead of a big packet train
  (P2,P3,P4 ...) filling the BQL budget and delaying P1 by many packets :/

To solve this problem, we have to block the dequeue process as long
as the first packet in bad_txq can not be sent. Reordering issues
disappear and no side effects have been seen.

Fixes: a53851e2c3 ("net: sched: explicit locking in gso_cpu fallback")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-09-06 15:12:33 +02:00
Davide Caratti 092e22e586 net/sched: pfifo_fast: fix wrong dereference in pfifo_fast_enqueue 
Now that 'TCQ_F_CPUSTATS' bit can be cleared, depending on the value of
'TCQ_F_NOLOCK' bit in the parent qdisc, we can't assume anymore that
per-cpu counters are there in the error path of skb_array_produce().
Otherwise, the following splat can be seen:

 Unable to handle kernel paging request at virtual address 0000600dea430008
 Mem abort info:
   ESR = 0x96000005
   Exception class = DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
 Data abort info:
   ISV = 0, ISS = 0x00000005
   CM = 0, WnR = 0
 user pgtable: 64k pages, 48-bit VAs, pgdp = 000000007b97530e
 [0000600dea430008] pgd=0000000000000000, pud=0000000000000000
 Internal error: Oops: 96000005 [#1] SMP
[...]
 pstate: 10000005 (nzcV daif -PAN -UAO)
 pc : pfifo_fast_enqueue+0x524/0x6e8
 lr : pfifo_fast_enqueue+0x46c/0x6e8
 sp : ffff800d39376fe0
 x29: ffff800d39376fe0 x28: 1ffff001a07d1e40
 x27: ffff800d03e8f188 x26: ffff800d03e8f200
 x25: 0000000000000062 x24: ffff800d393772f0
 x23: 0000000000000000 x22: 0000000000000403
 x21: ffff800cca569a00 x20: ffff800d03e8ee00
 x19: ffff800cca569a10 x18: 00000000000000bf
 x17: 0000000000000000 x16: 0000000000000000
 x15: 0000000000000000 x14: ffff1001a726edd0
 x13: 1fffe4000276a9a4 x12: 0000000000000000
 x11: dfff200000000000 x10: ffff800d03e8f1a0
 x9 : 0000000000000003 x8 : 0000000000000000
 x7 : 00000000f1f1f1f1 x6 : ffff1001a726edea
 x5 : ffff800cca56a53c x4 : 1ffff001bf9a8003
 x3 : 1ffff001bf9a8003 x2 : 1ffff001a07d1dcb
 x1 : 0000600dea430000 x0 : 0000600dea430008
 Process ping (pid: 6067, stack limit = 0x00000000dc0aa557)
 Call trace:
  pfifo_fast_enqueue+0x524/0x6e8
  htb_enqueue+0x660/0x10e0 [sch_htb]
  __dev_queue_xmit+0x123c/0x2de0
  dev_queue_xmit+0x24/0x30
  ip_finish_output2+0xc48/0x1720
  ip_finish_output+0x548/0x9d8
  ip_output+0x334/0x788
  ip_local_out+0x90/0x138
  ip_send_skb+0x44/0x1d0
  ip_push_pending_frames+0x5c/0x78
  raw_sendmsg+0xed8/0x28d0
  inet_sendmsg+0xc4/0x5c0
  sock_sendmsg+0xac/0x108
  __sys_sendto+0x1ac/0x2a0
  __arm64_sys_sendto+0xc4/0x138
  el0_svc_handler+0x13c/0x298
  el0_svc+0x8/0xc
 Code: f9402e80 d538d081 91002000 8b010000 (885f7c03)

Fix this by testing the value of 'TCQ_F_CPUSTATS' bit in 'qdisc->flags',
before dereferencing 'qdisc->cpu_qstats'.

Fixes: 8a53e616de ("net: sched: when clearing NOLOCK, clear TCQ_F_CPUSTATS, too")
CC: Paolo Abeni <pabeni@redhat.com>
CC: Stefano Brivio <sbrivio@redhat.com>
Reported-by: Li Shuang <shuali@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-08-28 15:57:38 -07:00
Davide Caratti 04d37cf46a net/sched: pfifo_fast: fix wrong dereference when qdisc is reset 
Now that 'TCQ_F_CPUSTATS' bit can be cleared, depending on the value of
'TCQ_F_NOLOCK' bit in the parent qdisc, we need to be sure that per-cpu
counters are present when 'reset()' is called for pfifo_fast qdiscs.
Otherwise, the following script:

 # tc q a dev lo handle 1: root htb default 100
 # tc c a dev lo parent 1: classid 1:100 htb \
 > rate 95Mbit ceil 100Mbit burst 64k
 [...]
 # tc f a dev lo parent 1: protocol arp basic classid 1:100
 [...]
 # tc q a dev lo parent 1:100 handle 100: pfifo_fast
 [...]
 # tc q d dev lo root

can generate the following splat:

 Unable to handle kernel paging request at virtual address dfff2c01bd148000
 Mem abort info:
   ESR = 0x96000004
   Exception class = DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
 Data abort info:
   ISV = 0, ISS = 0x00000004
   CM = 0, WnR = 0
 [dfff2c01bd148000] address between user and kernel address ranges
 Internal error: Oops: 96000004 [#1] SMP
 [...]
 pstate: 80000005 (Nzcv daif -PAN -UAO)
 pc : pfifo_fast_reset+0x280/0x4d8
 lr : pfifo_fast_reset+0x21c/0x4d8
 sp : ffff800d09676fa0
 x29: ffff800d09676fa0 x28: ffff200012ee22e4
 x27: dfff200000000000 x26: 0000000000000000
 x25: ffff800ca0799958 x24: ffff1001940f332b
 x23: 0000000000000007 x22: ffff200012ee1ab8
 x21: 0000600de8a40000 x20: 0000000000000000
 x19: ffff800ca0799900 x18: 0000000000000000
 x17: 0000000000000002 x16: 0000000000000000
 x15: 0000000000000000 x14: 0000000000000000
 x13: 0000000000000000 x12: ffff1001b922e6e2
 x11: 1ffff001b922e6e1 x10: 0000000000000000
 x9 : 1ffff001b922e6e1 x8 : dfff200000000000
 x7 : 0000000000000000 x6 : 0000000000000000
 x5 : 1fffe400025dc45c x4 : 1fffe400025dc357
 x3 : 00000c01bd148000 x2 : 0000600de8a40000
 x1 : 0000000000000007 x0 : 0000600de8a40004
 Call trace:
  pfifo_fast_reset+0x280/0x4d8
  qdisc_reset+0x6c/0x370
  htb_reset+0x150/0x3b8 [sch_htb]
  qdisc_reset+0x6c/0x370
  dev_deactivate_queue.constprop.5+0xe0/0x1a8
  dev_deactivate_many+0xd8/0x908
  dev_deactivate+0xe4/0x190
  qdisc_graft+0x88c/0xbd0
  tc_get_qdisc+0x418/0x8a8
  rtnetlink_rcv_msg+0x3a8/0xa78
  netlink_rcv_skb+0x18c/0x328
  rtnetlink_rcv+0x28/0x38
  netlink_unicast+0x3c4/0x538
  netlink_sendmsg+0x538/0x9a0
  sock_sendmsg+0xac/0xf8
  ___sys_sendmsg+0x53c/0x658
  __sys_sendmsg+0xc8/0x140
  __arm64_sys_sendmsg+0x74/0xa8
  el0_svc_handler+0x164/0x468
  el0_svc+0x10/0x14
 Code: 910012a0 92400801 d343fc03 11000c21 (38fb6863)

Fix this by testing the value of 'TCQ_F_CPUSTATS' bit in 'qdisc->flags',
before dereferencing 'qdisc->cpu_qstats'.

Changes since v1:
 - coding style improvements, thanks to Stefano Brivio

Fixes: 8a53e616de ("net: sched: when clearing NOLOCK, clear TCQ_F_CPUSTATS, too")
CC: Paolo Abeni <pabeni@redhat.com>
Reported-by: Li Shuang <shuali@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-08-28 14:45:46 -07:00
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2019-05-30 11:26:32 -07:00
Cong Wang 141b6b2ad7 net: add a generic tracepoint for TX queue timeout 
Although devlink health report does a nice job on reporting TX
timeout and other NIC errors, unfortunately it requires drivers
to support it but currently only mlx5 has implemented it.
Before other drivers could catch up, it is useful to have a
generic tracepoint to monitor this kind of TX timeout. We have
been suffering TX timeout with different drivers, we plan to
start to monitor it with rasdaemon which just needs a new tracepoint.

Sample output:

  ksoftirqd/1-16    [001] ..s2   144.043173: net_dev_xmit_timeout: dev=ens3 driver=e1000 queue=0

Cc: Eran Ben Elisha <eranbe@mellanox.com>
Cc: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-05-04 00:41:41 -04:00
Paolo Abeni 73eb628ddf Revert: "net: sched: put back q.qlen into a single location" 
This revert commit 46b1c18f9d ("net: sched: put back q.qlen into
a single location").
After the previous patch, when a NOLOCK qdisc is enslaved to a
locking qdisc it switches to global stats accounting. As a consequence,
when a classful qdisc accesses directly a child qdisc's qlen, such
qdisc is not doing per CPU accounting and qlen value is consistent.

In the control path nobody uses directly qlen since commit
e5f0e8f8e4 ("net: sched: introduce and use qdisc tree flush/purge
helpers"), so we can remove the contented atomic ops from the
datapath.

v1 -> v2:
 - complete the qdisc_qstats_atomic_qlen_dec() ->
   qdisc_qstats_cpu_qlen_dec() replacement, fix build issue
 - more descriptive commit message

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-04-10 12:20:46 -07:00
Paolo Abeni 8a53e616de net: sched: when clearing NOLOCK, clear TCQ_F_CPUSTATS, too 
Since stats updating is always consistent with TCQ_F_CPUSTATS flag,
we can disable it at qdisc creation time flipping such bit.

In my experiments, if the NOLOCK flag is cleared, per CPU stats
accounting does not give any measurable performance gain, but it
waste some memory.

Let's clear TCQ_F_CPUSTATS together with NOLOCK, when enslaving
a NOLOCK qdisc to 'lock' one.

Use stats update helper inside pfifo_fast, to cope correctly with
TCQ_F_CPUSTATS flag change.

As a side effect, q.qlen value for any child qdiscs is always
consistent for all lock classfull qdiscs.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-04-10 12:20:46 -07:00
Paolo Abeni 9c01c9f1f2 net: sched: always do stats accounting according to TCQ_F_CPUSTATS 
The core sched implementation checks independently for NOLOCK flag
to acquire/release the root spin lock and for qdisc_is_percpu_stats()
to account per CPU values in many places.

This change update the last few places checking the TCQ_F_NOLOCK to
do per CPU stats accounting according to qdisc_is_percpu_stats()
value.

The above allows to clean dev_requeue_skb() implementation a bit
and makes stats update always consistent with a single flag.

v1 -> v2:
 - do not move qdisc_is_empty definition, fix build issue

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-04-10 12:20:46 -07:00
Paolo Abeni 28cff537ef net: sched: add empty status flag for NOLOCK qdisc 
The queue is marked not empty after acquiring the seqlock,
and it's up to the NOLOCK qdisc clearing such flag on dequeue.
Since the empty status lays on the same cache-line of the
seqlock, it's always hot on cache during the updates.

This makes the empty flag update a little bit loosy. Given
the lack of synchronization between enqueue and dequeue, this
is unavoidable.

v2 -> v3:
 - qdisc_is_empty() has a const argument (Eric)

v1 -> v2:
 - use really an 'empty' flag instead of 'not_empty', as
   suggested by Eric

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-03-23 21:52:36 -04:00
David S. Miller 18a4d8bf25 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-03-04 13:26:15 -08:00
Eric Dumazet 46b1c18f9d net: sched: put back q.qlen into a single location 
In the series fc8b81a598 ("Merge branch 'lockless-qdisc-series'")
John made the assumption that the data path had no need to read
the qdisc qlen (number of packets in the qdisc).

It is true when pfifo_fast is used as the root qdisc, or as direct MQ/MQPRIO
children.

But pfifo_fast can be used as leaf in class full qdiscs, and existing
logic needs to access the child qlen in an efficient way.

HTB breaks badly, since it uses cl->leaf.q->q.qlen in :
  htb_activate() -> WARN_ON()
  htb_dequeue_tree() to decide if a class can be htb_deactivated
  when it has no more packets.

HFSC, DRR, CBQ, QFQ have similar issues, and some calls to
qdisc_tree_reduce_backlog() also read q.qlen directly.

Using qdisc_qlen_sum() (which iterates over all possible cpus)
in the data path is a non starter.

It seems we have to put back qlen in a central location,
at least for stable kernels.

For all qdisc but pfifo_fast, qlen is guarded by the qdisc lock,
so the existing q.qlen{++|--} are correct.

For 'lockless' qdisc (pfifo_fast so far), we need to use atomic_{inc|dec}()
because the spinlock might be not held (for example from
pfifo_fast_enqueue() and pfifo_fast_dequeue())

This patch adds atomic_qlen (in the same location than qlen)
and renames the following helpers, since we want to express
they can be used without qdisc lock, and that qlen is no longer percpu.

- qdisc_qstats_cpu_qlen_dec -> qdisc_qstats_atomic_qlen_dec()
- qdisc_qstats_cpu_qlen_inc -> qdisc_qstats_atomic_qlen_inc()

Later (net-next) we might revert this patch by tracking all these
qlen uses and replace them by a more efficient method (not having
to access a precise qlen, but an empty/non_empty status that might
be less expensive to maintain/track).

Another possibility is to have a legacy pfifo_fast version that would
be used when used a a child qdisc, since the parent qdisc needs
a spinlock anyway. But then, future lockless qdiscs would also
have the same problem.

Fixes: 7e66016f2c ("net: sched: helpers to sum qlen and qlen for per cpu logic")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-03-02 14:10:18 -08:00
Li RongQing 3b40bf4e24 net: Use RCU_POINTER_INITIALIZER() to init static variable 
This pointer is RCU protected, so proper primitives should be used.

Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-02-26 14:50:22 -08:00
David S. Miller 3313da8188 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 
The netfilter conflicts were rather simple overlapping
changes.

However, the cls_tcindex.c stuff was a bit more complex.

On the 'net' side, Cong is fixing several races and memory
leaks.  Whilst on the 'net-next' side we have Vlad adding
the rtnl-ness support.

What I've decided to do, in order to resolve this, is revert the
conversion over to using a workqueue that Cong did, bringing us back
to pure RCU.  I did it this way because I believe that either Cong's
races don't apply with have Vlad did things, or Cong will have to
implement the race fix slightly differently.

Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-02-15 12:38:38 -08:00
Vlad Buslov ed76f5edcc net: sched: protect filter_chain list with filter_chain_lock mutex 
Extend tcf_chain with new filter_chain_lock mutex. Always lock the chain
when accessing filter_chain list, instead of relying on rtnl lock.
Dereference filter_chain with tcf_chain_dereference() lockdep macro to
verify that all users of chain_list have the lock taken.

Rearrange tp insert/remove code in tc_new_tfilter/tc_del_tfilter to execute
all necessary code while holding chain lock in order to prevent
invalidation of chain_info structure by potential concurrent change. This
also serializes calls to tcf_chain0_head_change(), which allows head change
callbacks to rely on filter_chain_lock for synchronization instead of rtnl
mutex.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-02-12 13:41:32 -05:00
Jouke Witteveen 989723b00b Documentation: bring operstate documentation up-to-date 
Netlink has moved from bitmasks to group numbers long ago.

Signed-off-by: Jouke Witteveen <j.witteveen@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2019-02-11 12:38:51 -08:00
Paul E. McKenney ae0e33494a net/sched: Replace call_rcu_bh() and rcu_barrier_bh() 
Now that call_rcu()'s callback is not invoked until after bh-disable
regions of code have completed (in addition to explicitly marked
RCU read-side critical sections), call_rcu() can be used in place
of call_rcu_bh().  Similarly, rcu_barrier() can be used in place o
frcu_barrier_bh().  This commit therefore makes these changes.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: <netdev@vger.kernel.org>
 2018-12-01 12:38:46 -08:00
Eric Dumazet f98ebd47fd net: sched: avoid writing on noop_qdisc 
While noop_qdisc.gso_skb and noop_qdisc.skb_bad_txq are not used
in other places, it seems not correct to overwrite their fields
in dev_init_scheduler_queue().

noop_qdisc is essentially a shared and read-only object, even if
it is not marked as const because of some implementation detail.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2018-10-10 22:49:16 -07:00
Wei Yongjun 5362700c94 net: sched: make function qdisc_free_cb() static 
Fixes the following sparse warning:

net/sched/sch_generic.c:944:6: warning:
 symbol 'qdisc_free_cb' was not declared. Should it be static?

Fixes: 3a7d0d07a3 ("net: sched: extend Qdisc with rcu")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2018-09-28 11:04:58 -07:00
Vlad Buslov 3a7d0d07a3 net: sched: extend Qdisc with rcu 
Currently, Qdisc API functions assume that users have rtnl lock taken. To
implement rtnl unlocked classifiers update interface, Qdisc API must be
extended with functions that do not require rtnl lock.

Extend Qdisc structure with rcu. Implement special version of put function
qdisc_put_unlocked() that is called without rtnl lock taken. This function
only takes rtnl lock if Qdisc reference counter reached zero and is
intended to be used as optimization.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2018-09-25 20:17:35 -07:00
Vlad Buslov 86bd446b5c net: sched: rename qdisc_destroy() to qdisc_put() 
Current implementation of qdisc_destroy() decrements Qdisc reference
counter and only actually destroy Qdisc if reference counter value reached
zero. Rename qdisc_destroy() to qdisc_put() in order for it to better
describe the way in which this function currently implemented and used.

Extract code that deallocates Qdisc into new private qdisc_destroy()
function. It is intended to be shared between regular qdisc_put() and its
unlocked version that is introduced in next patch in this series.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2018-09-25 20:17:35 -07:00
David S. Miller a8305bff68 net: Add and use skb_mark_not_on_list(). 
An SKB is not on a list if skb->next is NULL.

Codify this convention into a helper function and use it
where we are dequeueing an SKB and need to mark it as such.

Signed-off-by: David S. Miller <davem@davemloft.net>
 2018-09-10 10:06:54 -07:00
Song Liu 4341f8308d net: remove bypassed check in sch_direct_xmit() 
Checking netif_xmit_frozen_or_stopped() at the end of sch_direct_xmit()
is being bypassed. This is because "ret" from sch_direct_xmit() will be
either NETDEV_TX_OK or NETDEV_TX_BUSY, and only ret == NETDEV_TX_OK == 0
will reach the condition:

    if (ret && netif_xmit_frozen_or_stopped(txq))
        return false;

This patch cleans up the code by removing the whole condition.

For more discussion about this, please refer to
   https://marc.info/?t=152727195700008

Signed-off-by: Song Liu <songliubraving@fb.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2018-05-31 13:26:19 -04:00
Paolo Abeni 021a17ed79 pfifo_fast: drop unneeded additional lock on dequeue 
After the previous patch, for NOLOCK qdiscs, q->seqlock is
always held when the dequeue() is invoked, we can drop
any additional locking to protect such operation.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2018-05-17 12:46:54 -04:00
Paolo Abeni 96009c7d50 sched: replace __QDISC_STATE_RUNNING bit with a spin lock 
So that we can use lockdep on it.
The newly introduced sequence lock has the same scope of busylock,
so it shares the same lockdep annotation, but it's only used for
NOLOCK qdiscs.

With this changeset we acquire such lock in the control path around
flushing operation (qdisc reset), to allow more NOLOCK qdisc perf
improvement in the next patch.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2018-05-17 12:46:54 -04:00
Paolo Abeni 32f7b44d0f sched: manipulate __QDISC_STATE_RUNNING in qdisc_run_* helpers 
Currently NOLOCK qdiscs pay a measurable overhead to atomically
manipulate the __QDISC_STATE_RUNNING. Such bit is flipped twice per
packet in the uncontended scenario with packet rate below the
line rate: on packed dequeue and on the next, failing dequeue attempt.

This changeset moves the bit manipulation into the qdisc_run_{begin,end}
helpers, so that the bit is now flipped only once per packet, with
measurable performance improvement in the uncontended scenario.

This also allows simplifying the qdisc teardown code path - since
qdisc_is_running() is now effective for each qdisc type - and avoid a
possible race between qdisc_run() and dev_deactivate_many(), as now
the some_qdisc_is_busy() can properly detect NOLOCK qdiscs being busy
dequeuing packets.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2018-05-16 12:26:25 -04:00
John Fastabend eb82a99447 net: sched, fix OOO packets with pfifo_fast 
After the qdisc lock was dropped in pfifo_fast we allow multiple
enqueue threads and dequeue threads to run in parallel. On the
enqueue side the skb bit ooo_okay is used to ensure all related
skbs are enqueued in-order. On the dequeue side though there is
no similar logic. What we observe is with fewer queues than CPUs
it is possible to re-order packets when two instances of
__qdisc_run() are running in parallel. Each thread will dequeue
a skb and then whichever thread calls the ndo op first will
be sent on the wire. This doesn't typically happen because
qdisc_run() is usually triggered by the same core that did the
enqueue. However, drivers will trigger __netif_schedule()
when queues are transitioning from stopped to awake using the
netif_tx_wake_* APIs. When this happens netif_schedule() calls
qdisc_run() on the same CPU that did the netif_tx_wake_* which
is usually done in the interrupt completion context. This CPU
is selected with the irq affinity which is unrelated to the
enqueue operations.

To resolve this we add a RUNNING bit to the qdisc to ensure
only a single dequeue per qdisc is running. Enqueue and dequeue
operations can still run in parallel and also on multi queue
NICs we can still have a dequeue in-flight per qdisc, which
is typically per CPU.

Fixes: c5ad119fb6 ("net: sched: pfifo_fast use skb_array")
Reported-by: Jakob Unterwurzacher <jakob.unterwurzacher@theobroma-systems.com>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2018-03-26 12:36:23 -04:00
Eric Dumazet cce6294cc2 net: sched: fix uses after free 
syzbot reported one use-after-free in pfifo_fast_enqueue() [1]

Issue here is that we can not reuse skb after a successful skb_array_produce()
since another cpu might have consumed it already.

I believe a similar problem exists in try_bulk_dequeue_skb_slow()
in case we put an skb into qdisc_enqueue_skb_bad_txq() for lockless qdisc.

[1]
BUG: KASAN: use-after-free in qdisc_pkt_len include/net/sch_generic.h:610 [inline]
BUG: KASAN: use-after-free in qdisc_qstats_cpu_backlog_inc include/net/sch_generic.h:712 [inline]
BUG: KASAN: use-after-free in pfifo_fast_enqueue+0x4bc/0x5e0 net/sched/sch_generic.c:639
Read of size 4 at addr ffff8801cede37e8 by task syzkaller717588/5543

CPU: 1 PID: 5543 Comm: syzkaller717588 Not tainted 4.16.0-rc4+ #265
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+0x194/0x24d lib/dump_stack.c:53
 print_address_description+0x73/0x250 mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report+0x23c/0x360 mm/kasan/report.c:412
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432
 qdisc_pkt_len include/net/sch_generic.h:610 [inline]
 qdisc_qstats_cpu_backlog_inc include/net/sch_generic.h:712 [inline]
 pfifo_fast_enqueue+0x4bc/0x5e0 net/sched/sch_generic.c:639
 __dev_xmit_skb net/core/dev.c:3216 [inline]

Fixes: c5ad119fb6 ("net: sched: pfifo_fast use skb_array")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot+ed43b6903ab968b16f54@syzkaller.appspotmail.com
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc:	Cong Wang <xiyou.wangcong@gmail.com>
Cc:	Jiri Pirko <jiri@resnulli.us>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2018-03-17 17:03:45 -04:00