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  1. 02 4月, 2021 4 次提交
  3. 30 3月, 2021 1 次提交
  5. 29 3月, 2021 2 次提交
  7. 27 3月, 2021 3 次提交
  9. 26 3月, 2021 1 次提交
    • Y
      bpf: Fix NULL pointer dereference in bpf_get_local_storage() helper · b910eaaa
      由 Yonghong Song 提交于 
      Jiri Olsa reported a bug ([1]) in kernel where cgroup local
storage pointer may be NULL in bpf_get_local_storage() helper.
There are two issues uncovered by this bug:
  (1). kprobe or tracepoint prog incorrectly sets cgroup local storage
       before prog run,
  (2). due to change from preempt_disable to migrate_disable,
       preemption is possible and percpu storage might be overwritten
       by other tasks.

This issue (1) is fixed in [2]. This patch tried to address issue (2).
The following shows how things can go wrong:
  task 1:   bpf_cgroup_storage_set() for percpu local storage
         preemption happens
  task 2:   bpf_cgroup_storage_set() for percpu local storage
         preemption happens
  task 1:   run bpf program

task 1 will effectively use the percpu local storage setting by task 2
which will be either NULL or incorrect ones.

Instead of just one common local storage per cpu, this patch fixed
the issue by permitting 8 local storages per cpu and each local
storage is identified by a task_struct pointer. This way, we
allow at most 8 nested preemption between bpf_cgroup_storage_set()
and bpf_cgroup_storage_unset(). The percpu local storage slot
is released (calling bpf_cgroup_storage_unset()) by the same task
after bpf program finished running.
bpf_test_run() is also fixed to use the new bpf_cgroup_storage_set()
interface.

The patch is tested on top of [2] with reproducer in [1].
Without this patch, kernel will emit error in 2-3 minutes.
With this patch, after one hour, still no error.

 [1] https://lore.kernel.org/bpf/CAKH8qBuXCfUz=w8L+Fj74OaUpbosO29niYwTki7e3Ag044_aww@mail.gmail.com/T
 [2] https://lore.kernel.org/bpf/20210309185028.3763817-1-yhs@fb.comSigned-off-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NRoman Gushchin <guro@fb.com>
Link: https://lore.kernel.org/bpf/20210323055146.3334476-1-yhs@fb.com
      b910eaaa
  11. 25 3月, 2021 25 次提交
  13. 24 3月, 2021 4 次提交
    • D
      net: make unregister netdev warning timeout configurable · 5aa3afe1
      由 Dmitry Vyukov 提交于 
      netdev_wait_allrefs() issues a warning if refcount does not drop to 0
after 10 seconds. While 10 second wait generally should not happen
under normal workload in normal environment, it seems to fire falsely
very often during fuzzing and/or in qemu emulation (~10x slower).
At least it's not possible to understand if it's really a false
positive or not. Automated testing generally bumps all timeouts
to very high values to avoid flake failures.
Add net.core.netdev_unregister_timeout_secs sysctl to make
the timeout configurable for automated testing systems.
Lowering the timeout may also be useful for e.g. manual bisection.
The default value matches the current behavior.
Signed-off-by: NDmitry Vyukov <dvyukov@google.com>
Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=211877
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      5aa3afe1
    • V
      net: dsa: sync up switchdev objects and port attributes when joining the bridge · 010e269f
      由 Vladimir Oltean 提交于 
      If we join an already-created bridge port, such as a bond master
interface, then we can miss the initial switchdev notifications emitted
by the bridge for this port, while it wasn't offloaded by anybody.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      010e269f
    • V
      net: dsa: inherit the actual bridge port flags at join time · 5961d6a1
      由 Vladimir Oltean 提交于 
      DSA currently assumes that the bridge port starts off with this
constellation of bridge port flags:

- learning on
- unicast flooding on
- multicast flooding on
- broadcast flooding on

just by virtue of code copy-pasta from the bridge layer (new_nbp).
This was a simple enough strategy thus far, because the 'bridge join'
moment always coincided with the 'bridge port creation' moment.

But with sandwiched interfaces, such as:

 br0
  |
bond0
  |
 swp0

it may happen that the user has had time to change the bridge port flags
of bond0 before enslaving swp0 to it. In that case, swp0 will falsely
assume that the bridge port flags are those determined by new_nbp, when
in fact this can happen:

ip link add br0 type bridge
ip link add bond0 type bond
ip link set bond0 master br0
ip link set bond0 type bridge_slave learning off
ip link set swp0 master br0

Now swp0 has learning enabled, bond0 has learning disabled. Not nice.

Fix this by "dumpster diving" through the actual bridge port flags with
br_port_flag_is_set, at bridge join time.

We use this opportunity to split dsa_port_change_brport_flags into two
distinct functions called dsa_port_inherit_brport_flags and
dsa_port_clear_brport_flags, now that the implementation for the two
cases is no longer similar. This patch also creates two functions called
dsa_port_switchdev_sync and dsa_port_switchdev_unsync which collect what
we have so far, even if that's asymmetrical. More is going to be added
in the next patch.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      5961d6a1
    • V
      net: dsa: pass extack to dsa_port_{bridge,lag}_join · 2afc526a
      由 Vladimir Oltean 提交于 
      This is a pretty noisy change that was broken out of the larger change
for replaying switchdev attributes and objects at bridge join time,
which is when these extack objects are actually used.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: NTobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2afc526a