linux/include
Cong Wang 7aa0045dad net_sched: introduce a workqueue for RCU callbacks of tc filter
This patch introduces a dedicated workqueue for tc filters
so that each tc filter's RCU callback could defer their
action destroy work to this workqueue. The helper
tcf_queue_work() is introduced for them to use.

Because we hold RTNL lock when calling tcf_block_put(), we
can not simply flush works inside it, therefore we have to
defer it again to this workqueue and make sure all flying RCU
callbacks have already queued their work before this one, in
other words, to ensure this is the last one to execute to
prevent any use-after-free.

On the other hand, this makes tcf_block_put() ugly and
harder to understand. Since David and Eric strongly dislike
adding synchronize_rcu(), this is probably the only
solution that could make everyone happy.

Please also see the code comments below.

Reported-by: Chris Mi <chrism@mellanox.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-29 22:49:30 +09:00
..
acpi ACPI / bus: Make ACPI_HANDLE() work for non-GPL code again 2017-09-19 22:42:31 +02:00
asm-generic percpu: make this_cpu_generic_read() atomic w.r.t. interrupts 2017-09-26 07:37:33 -07:00
clocksource
crypto
drm lib/interval_tree: fast overlap detection 2017-09-08 18:26:49 -07:00
dt-bindings ARC: reset: remove the misleading v1 suffix all over 2017-09-18 13:02:03 +02:00
keys
kvm
linux sctp: fix some type cast warnings introduced since very beginning 2017-10-29 18:03:24 +09:00
math-emu
media media updates for v4.14-rc1 2017-09-07 12:53:14 -07:00
memory
misc
net net_sched: introduce a workqueue for RCU callbacks of tc filter 2017-10-29 22:49:30 +09:00
pcmcia
ras
rdma IB: Correct MR length field to be 64-bit 2017-09-25 11:47:23 -04:00
scsi scsi: libiscsi: Remove iscsi_destroy_session 2017-10-02 22:23:21 -04:00
soc ARM: SoC driver updates for v4.14 2017-09-10 20:40:00 -07:00
sound ALSA: hda - Fix incorrect TLV callback check introduced during set_fs() removal 2017-10-18 12:27:00 +02:00
target
trace sched/debug: Add explicit TASK_PARKED printing 2017-09-29 11:02:57 +02:00
uapi sctp: fix some type cast warnings introduced since very beginning 2017-10-29 18:03:24 +09:00
video
xen xen, arm64: drop dummy lookup_address() 2017-09-19 09:25:05 -04:00