Eric Lee / smarc-fsl-linux-kernel

25 May, 2018

1 commit

  • aaa908ffb   net_sched: switch to rcu_work ... Browse Code »

    Commit 05f0fe6b74db ("RCU, workqueue: Implement rcu_work") introduces
    new API's for dispatching work in a RCU callback. Now we can just
    switch to the new API's for tc filters. This could get rid of a lot
    of code.

    Cc: Tejun Heo
    Cc: "Paul E. McKenney"
    Cc: Jamal Hadi Salim
    Signed-off-by: Cong Wang
    Signed-off-by: David S. Miller

    Cong Wang
     

25 Jan, 2018

1 commit

20 Jan, 2018

3 commits

09 Nov, 2017

1 commit

  • 96585063a   cls_rsvp: use tcf_exts_get_net() before call_rcu() ... Browse Code »

    Hold netns refcnt before call_rcu() and release it after
    the tcf_exts_destroy() is done.

    Note, on ->destroy() path we have to respect the return value
    of tcf_exts_get_net(), on other paths it should always return
    true, so we don't need to care.

    Cc: Lucas Bates
    Cc: Jamal Hadi Salim
    Cc: Jiri Pirko
    Signed-off-by: Cong Wang
    Signed-off-by: David S. Miller

    Cong Wang
     

29 Oct, 2017

1 commit

  • d4f84a41d   net_sched: use tcf_queue_work() in rsvp filter ... Browse Code »

    Defer the tcf_exts_destroy() in RCU callback to
    tc filter workqueue and get RTNL lock.

    Reported-by: Chris Mi
    Cc: Daniel Borkmann
    Cc: Jiri Pirko
    Cc: John Fastabend
    Cc: Jamal Hadi Salim
    Cc: "Paul E. McKenney"
    Signed-off-by: Cong Wang
    Signed-off-by: David S. Miller

    Cong Wang
     

12 Sep, 2017

1 commit

  • 230cfd2db   net/sched: fix pointer check in gen_handle ... Browse Code »

    Fixes sparse warning about pointer in gen_handle:
    net/sched/cls_rsvp.h:392:40: warning: Using plain integer as NULL pointer

    Fixes: 8113c095672f6 ("net_sched: use void pointer for filter handle")
    Signed-off-by: Josh Hunt
    Acked-by: Cong Wang
    Signed-off-by: David S. Miller

    Josh Hunt
     

01 Sep, 2017

1 commit

  • 07d79fc7d   net_sched: add reverse binding for tc class ... Browse Code »

    TC filters when used as classifiers are bound to TC classes.
    However, there is a hidden difference when adding them in different
    orders:

    1. If we add tc classes before its filters, everything is fine.
    Logically, the classes exist before we specify their ID's in
    filters, it is easy to bind them together, just as in the current
    code base.

    2. If we add tc filters before the tc classes they bind, we have to
    do dynamic lookup in fast path. What's worse, this happens all
    the time not just once, because on fast path tcf_result is passed
    on stack, there is no way to propagate back to the one in tc filters.

    This hidden difference hurts performance silently if we have many tc
    classes in hierarchy.

    This patch intends to close this gap by doing the reverse binding when
    we create a new class, in this case we can actually search all the
    filters in its parent, match and fixup by classid. And because
    tcf_result is specific to each type of tc filter, we have to introduce
    a new ops for each filter to tell how to bind the class.

    Note, we still can NOT totally get rid of those class lookup in
    ->enqueue() because cgroup and flow filters have no way to determine
    the classid at setup time, they still have to go through dynamic lookup.

    Cc: Jamal Hadi Salim
    Signed-off-by: Cong Wang
    Signed-off-by: David S. Miller

    Cong Wang
     

08 Aug, 2017

1 commit

  • 8113c0956   net_sched: use void pointer for filter handle ... Browse Code »

    Now we use 'unsigned long fh' as a pointer in every place,
    it is safe to convert it to a void pointer now. This gets
    rid of many casts to pointer.

    Cc: Jamal Hadi Salim
    Cc: Jiri Pirko
    Signed-off-by: Cong Wang
    Acked-by: Jamal Hadi Salim
    Signed-off-by: David S. Miller

    WANG Cong
     

05 Aug, 2017

1 commit

22 Apr, 2017

2 commits

  • 439205387   net_sched: remove useless NULL to tp->root ... Browse Code »

    There is no need to NULL tp->root in ->destroy(), since tp is
    going to be freed very soon, and existing readers are still
    safe to read them.

    For cls_route, we always init its tp->root, so it can't be NULL,
    we can drop more useless code.

    Cc: Daniel Borkmann
    Cc: John Fastabend
    Cc: Jamal Hadi Salim
    Signed-off-by: Cong Wang
    Signed-off-by: David S. Miller

    WANG Cong
     
  • 763dbf632   net_sched: move the empty tp check from ->destroy() to ->delete() ... Browse Code »

    We could have a race condition where in ->classify() path we
    dereference tp->root and meanwhile a parallel ->destroy() makes it
    a NULL. Daniel cured this bug in commit d936377414fa
    ("net, sched: respect rcu grace period on cls destruction").

    This happens when ->destroy() is called for deleting a filter to
    check if we are the last one in tp, this tp is still linked and
    visible at that time. The root cause of this problem is the semantic
    of ->destroy(), it does two things (for non-force case):

    1) check if tp is empty
    2) if tp is empty we could really destroy it

    and its caller, if cares, needs to check its return value to see if it
    is really destroyed. Therefore we can't unlink tp unless we know it is
    empty.

    As suggested by Daniel, we could actually move the test logic to ->delete()
    so that we can safely unlink tp after ->delete() tells us the last one is
    just deleted and before ->destroy().

    Fixes: 1e052be69d04 ("net_sched: destroy proto tp when all filters are gone")
    Cc: Roi Dayan
    Cc: Daniel Borkmann
    Cc: John Fastabend
    Cc: Jamal Hadi Salim
    Signed-off-by: Cong Wang
    Acked-by: Daniel Borkmann
    Signed-off-by: David S. Miller

    WANG Cong
     

14 Apr, 2017

1 commit

28 Nov, 2016

1 commit

  • d93637741   net, sched: respect rcu grace period on cls destruction ... Browse Code »

    Roi reported a crash in flower where tp->root was NULL in ->classify()
    callbacks. Reason is that in ->destroy() tp->root is set to NULL via
    RCU_INIT_POINTER(). It's problematic for some of the classifiers, because
    this doesn't respect RCU grace period for them, and as a result, still
    outstanding readers from tc_classify() will try to blindly dereference
    a NULL tp->root.

    The tp->root object is strictly private to the classifier implementation
    and holds internal data the core such as tc_ctl_tfilter() doesn't know
    about. Within some classifiers, such as cls_bpf, cls_basic, etc, tp->root
    is only checked for NULL in ->get() callback, but nowhere else. This is
    misleading and seemed to be copied from old classifier code that was not
    cleaned up properly. For example, d3fa76ee6b4a ("[NET_SCHED]: cls_basic:
    fix NULL pointer dereference") moved tp->root initialization into ->init()
    routine, where before it was part of ->change(), so ->get() had to deal
    with tp->root being NULL back then, so that was indeed a valid case, after
    d3fa76ee6b4a, not really anymore. We used to set tp->root to NULL long
    ago in ->destroy(), see 47a1a1d4be29 ("pkt_sched: remove unnecessary xchg()
    in packet classifiers"); but the NULLifying was reintroduced with the
    RCUification, but it's not correct for every classifier implementation.

    In the cases that are fixed here with one exception of cls_cgroup, tp->root
    object is allocated and initialized inside ->init() callback, which is always
    performed at a point in time after we allocate a new tp, which means tp and
    thus tp->root was not globally visible in the tp chain yet (see tc_ctl_tfilter()).
    Also, on destruction tp->root is strictly kfree_rcu()'ed in ->destroy()
    handler, same for the tp which is kfree_rcu()'ed right when we return
    from ->destroy() in tcf_destroy(). This means, the head object's lifetime
    for such classifiers is always tied to the tp lifetime. The RCU callback
    invocation for the two kfree_rcu() could be out of order, but that's fine
    since both are independent.

    Dropping the RCU_INIT_POINTER(tp->root, NULL) for these classifiers here
    means that 1) we don't need a useless NULL check in fast-path and, 2) that
    outstanding readers of that tp in tc_classify() can still execute under
    respect with RCU grace period as it is actually expected.

    Things that haven't been touched here: cls_fw and cls_route. They each
    handle tp->root being NULL in ->classify() path for historic reasons, so
    their ->destroy() implementation can stay as is. If someone actually
    cares, they could get cleaned up at some point to avoid the test in fast
    path. cls_u32 doesn't set tp->root to NULL. For cls_rsvp, I just added a
    !head should anyone actually be using/testing it, so it at least aligns with
    cls_fw and cls_route. For cls_flower we additionally need to defer rhashtable
    destruction (to a sleepable context) after RCU grace period as concurrent
    readers might still access it. (Note that in this case we need to hold module
    reference to keep work callback address intact, since we only wait on module
    unload for all call_rcu()s to finish.)

    This fixes one race to bring RCU grace period guarantees back. Next step
    as worked on by Cong however is to fix 1e052be69d04 ("net_sched: destroy
    proto tp when all filters are gone") to get the order of unlinking the tp
    in tc_ctl_tfilter() for the RTM_DELTFILTER case right by moving
    RCU_INIT_POINTER() before tcf_destroy() and let the notification for
    removal be done through the prior ->delete() callback. Both are independant
    issues. Once we have that right, we can then clean tp->root up for a number
    of classifiers by not making them RCU pointers, which requires a new callback
    (->uninit) that is triggered from tp's RCU callback, where we just kfree()
    tp->root from there.

    Fixes: 1f947bf151e9 ("net: sched: rcu'ify cls_bpf")
    Fixes: 9888faefe132 ("net: sched: cls_basic use RCU")
    Fixes: 70da9f0bf999 ("net: sched: cls_flow use RCU")
    Fixes: 77b9900ef53a ("tc: introduce Flower classifier")
    Fixes: bf3994d2ed31 ("net/sched: introduce Match-all classifier")
    Fixes: 952313bd6258 ("net: sched: cls_cgroup use RCU")
    Reported-by: Roi Dayan
    Signed-off-by: Daniel Borkmann
    Cc: Cong Wang
    Cc: John Fastabend
    Cc: Roi Dayan
    Cc: Jiri Pirko
    Acked-by: John Fastabend
    Acked-by: Cong Wang
    Signed-off-by: David S. Miller

    Daniel Borkmann
     

23 Aug, 2016

1 commit

  • b9a24bb76   net_sched: properly handle failure case of tcf_exts_init() ... Browse Code »

    After commit 22dc13c837c3 ("net_sched: convert tcf_exts from list to pointer array")
    we do dynamic allocation in tcf_exts_init(), therefore we need
    to handle the ENOMEM case properly.

    Cc: Jamal Hadi Salim
    Signed-off-by: Cong Wang
    Acked-by: Jamal Hadi Salim
    Acked-by: Jamal Hadi Salim
    Signed-off-by: David S. Miller

    WANG Cong
     

27 Aug, 2015

1 commit

10 Mar, 2015

1 commit

  • 1e052be69   net_sched: destroy proto tp when all filters are gone ... Browse Code »

    Kernel automatically creates a tp for each
    (kind, protocol, priority) tuple, which has handle 0,
    when we add a new filter, but it still is left there
    after we remove our own, unless we don't specify the
    handle (literally means all the filters under
    the tuple). For example this one is left:

    # tc filter show dev eth0
    filter parent 8001: protocol arp pref 49152 basic

    The user-space is hard to clean up these for kernel
    because filters like u32 are organized in a complex way.
    So kernel is responsible to remove it after all filters
    are gone. Each type of filter has its own way to
    store the filters, so each type has to provide its
    way to check if all filters are gone.

    Cc: Jamal Hadi Salim
    Signed-off-by: Cong Wang
    Signed-off-by: Cong Wang
    Acked-by: Jamal Hadi Salim
    Signed-off-by: David S. Miller

    Cong Wang
     

10 Dec, 2014

2 commits

29 Sep, 2014

2 commits

14 Sep, 2014

1 commit

28 Apr, 2014

1 commit

  • 2f7ef2f87   sched, cls: check if we could overwrite actions when changing a filter ... Browse Code »

    When actions are attached to a filter, they are a part of the filter
    itself, so when changing a filter we should allow to overwrite the actions
    inside as well.

    In my specific case, when I tried to _append_ a new action to an existing
    filter which already has an action, I got EEXIST since kernel refused
    to overwrite the existing one in kernel.

    This patch checks if we are changing the filter checking NLM_F_CREATE flag
    (Sigh, filters don't use NLM_F_REPLACE...) and then passes the boolean down
    to actions. This fixes the problem above.

    Cc: Jamal Hadi Salim
    Cc: David S. Miller
    Signed-off-by: Cong Wang
    Signed-off-by: Cong Wang
    Signed-off-by: Jamal Hadi Salim
    Signed-off-by: David S. Miller

    Cong Wang
     

14 Jan, 2014

1 commit

19 Dec, 2013

2 commits

  • 5da57f422   net_sched: cls: refactor out struct tcf_ext_map ... Browse Code »

    These information can be saved in tcf_exts, and this will
    simplify the code.

    Cc: Jamal Hadi Salim
    Cc: David S. Miller
    Signed-off-by: Cong Wang
    Signed-off-by: Jamal Hadi Salim
    Signed-off-by: David S. Miller

    WANG Cong
     
  • 33be62715   net_sched: act: use standard struct list_head ... Browse Code »

    Currently actions are chained by a singly linked list,
    therefore it is a bit hard to add and remove a specific
    entry. Convert it to struct list_head so that in the
    latter patch we can remove an action without finding
    its head.

    Cc: Jamal Hadi Salim
    Cc: David S. Miller
    Signed-off-by: Cong Wang
    Signed-off-by: Jamal Hadi Salim
    Signed-off-by: David S. Miller

    WANG Cong
     

15 Jan, 2013

1 commit

  • c1b52739e   pkt_sched: namespace aware act_mirred ... Browse Code »

    Eric Dumazet pointed out that act_mirred needs to find the current net_ns,
    and struct net pointer is not provided in the call chain. His original
    patch made use of current->nsproxy->net_ns to find the network namespace,
    but this fails to work correctly for userspace code that makes use of
    netlink sockets in different network namespaces. Instead, pass the
    "struct net *" down along the call chain to where it is needed.

    This version removes the ifb changes as Eric has submitted that patch
    separately, but is otherwise identical to the previous version.

    Signed-off-by: Benjamin LaHaise
    Tested-by: Eric Dumazet
    Acked-by: Jamal Hadi Salim
    Signed-off-by: David S. Miller

    Benjamin LaHaise
     

15 Aug, 2012

1 commit

  • af4c6641f   net sched: Pass the skb into change so it can access NETLINK_CB ... Browse Code »

    cls_flow.c plays with uids and gids. Unless I misread that
    code it is possible for classifiers to depend on the specific uid and
    gid values. Therefore I need to know the user namespace of the
    netlink socket that is installing the packet classifiers. Pass
    in the rtnetlink skb so I can access the NETLINK_CB of the passed
    packet. In particular I want access to sk_user_ns(NETLINK_CB(in_skb).ssk).

    Pass in not the user namespace but the incomming rtnetlink skb into
    the the classifier change routines as that is generally the more useful
    parameter.

    Cc: Jamal Hadi Salim
    Acked-by: David S. Miller
    Acked-by: Serge Hallyn
    Signed-off-by: Eric W. Biederman

    Eric W. Biederman
     

02 Apr, 2012

1 commit

16 Sep, 2011

1 commit

06 Jul, 2011

1 commit

22 Jun, 2011

1 commit

20 Jan, 2011

1 commit

05 Aug, 2010

1 commit

30 Nov, 2009

1 commit

29 Jan, 2008

4 commits