Eric Lee / smarc-fsl-linux-kernel

17 Jul, 2020

1 commit

08 Jul, 2020

1 commit

  • 964201de6   net/sched: Use fallthrough pseudo-keyword ... Browse Code »

    Replace the existing /* fall through */ comments and its variants with
    the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
    fall-through markings when it is the case.

    [1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

    Signed-off-by: Gustavo A. R. Silva
    Signed-off-by: David S. Miller

    Gustavo A. R. Silva
     

30 Jun, 2020

1 commit

  • aebe4426c   net: sched: Pass root lock to Qdisc_ops.enqueue ... Browse Code »

    A following patch introduces qevents, points in qdisc algorithm where
    packet can be processed by user-defined filters. Should this processing
    lead to a situation where a new packet is to be enqueued on the same port,
    holding the root lock would lead to deadlocks. To solve the issue, qevent
    handler needs to unlock and relock the root lock when necessary.

    To that end, add the root lock argument to the qdisc op enqueue, and
    propagate throughout.

    Signed-off-by: Petr Machata
    Signed-off-by: David S. Miller

    Petr Machata
     

19 Jun, 2019

1 commit

  • d2912cb15   treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 ... Browse Code »

    Based on 2 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 version 2 as
    published by the free software foundation

    this program is free software you can redistribute it and or modify
    it under the terms of the gnu general public license version 2 as
    published by the free software foundation #

    extracted by the scancode license scanner the SPDX license identifier

    GPL-2.0-only

    has been chosen to replace the boilerplate/reference in 4122 file(s).

    Signed-off-by: Thomas Gleixner
    Reviewed-by: Enrico Weigelt
    Reviewed-by: Kate Stewart
    Reviewed-by: Allison Randal
    Cc: linux-spdx@vger.kernel.org
    Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
    Signed-off-by: Greg Kroah-Hartman

    Thomas Gleixner
     

28 Apr, 2019

2 commits

  • 8cb081746   netlink: make validation more configurable for future strictness ... Browse Code »

    We currently have two levels of strict validation:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    In effect then, this adds fully strict validation for any new command.

    Signed-off-by: Johannes Berg
    Signed-off-by: David S. Miller

    Johannes Berg
     
  • ae0be8de9   netlink: make nla_nest_start() add NLA_F_NESTED flag ... Browse Code »

    Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most
    netlink based interfaces (including recently added ones) are still not
    setting it in kernel generated messages. Without the flag, message parsers
    not aware of attribute semantics (e.g. wireshark dissector or libmnl's
    mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display
    the structure of their contents.

    Unfortunately we cannot just add the flag everywhere as there may be
    userspace applications which check nlattr::nla_type directly rather than
    through a helper masking out the flags. Therefore the patch renames
    nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start()
    as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually
    are rewritten to use nla_nest_start().

    Except for changes in include/net/netlink.h, the patch was generated using
    this semantic patch:

    @@ expression E1, E2; @@
    -nla_nest_start(E1, E2)
    +nla_nest_start_noflag(E1, E2)

    @@ expression E1, E2; @@
    -nla_nest_start_noflag(E1, E2 | NLA_F_NESTED)
    +nla_nest_start(E1, E2)

    Signed-off-by: Michal Kubecek
    Acked-by: Jiri Pirko
    Acked-by: David Ahern
    Signed-off-by: David S. Miller

    Michal Kubecek
     

02 Apr, 2019

2 commits

  • e5f0e8f8e   net: sched: introduce and use qdisc tree flush/purge helpers ... Browse Code »

    The same code to flush qdisc tree and purge the qdisc queue
    is duplicated in many places and in most cases it does not
    respect NOLOCK qdisc: the global backlog len is used and the
    per CPU values are ignored.

    This change addresses the above, factoring-out the relevant
    code and using the helpers introduced by the previous patch
    to fetch the correct backlog len.

    Fixes: c5ad119fb6c0 ("net: sched: pfifo_fast use skb_array")
    Signed-off-by: Paolo Abeni
    Signed-off-by: David S. Miller

    Paolo Abeni
     
  • 5dd431b6b   net: sched: introduce and use qstats read helpers ... Browse Code »

    Classful qdiscs can't access directly the child qdiscs backlog
    length: if such qdisc is NOLOCK, per CPU values should be
    accounted instead.

    Most qdiscs no not respect the above. As a result, qstats fetching
    for most classful qdisc is currently incorrect: if the child qdisc is
    NOLOCK, it always reports 0 len backlog.

    This change introduces a pair of helpers to safely fetch
    both backlog and qlen and use them in stats class dumping
    functions, fixing the above issue and cleaning a bit the code.

    DRR needs also to access the child qdisc queue length, so it
    needs custom handling.

    Fixes: c5ad119fb6c0 ("net: sched: pfifo_fast use skb_array")
    Signed-off-by: Paolo Abeni
    Signed-off-by: David S. Miller

    Paolo Abeni
     

16 Jan, 2019

2 commits

  • 37d9cf1a3   sched: Fix detection of empty queues in child qdiscs ... Browse Code »

    Several qdiscs check on enqueue whether the packet was enqueued to a class
    with an empty queue, in which case the class is activated. This is done by
    checking if the qlen is exactly 1 after enqueue. However, if GSO splitting
    is enabled in the child qdisc, a single packet can result in a qlen longer
    than 1. This means the activation check fails, leading to a stalled queue.

    Fix this by checking if the queue is empty *before* enqueue, and running
    the activation logic if this was the case.

    Reported-by: Pete Heist
    Signed-off-by: Toke Høiland-Jørgensen
    Signed-off-by: David S. Miller

    Toke Høiland-Jørgensen
     
  • f6bab1993   sched: Avoid dereferencing skb pointer after child enqueue ... Browse Code »

    Parent qdiscs may dereference the pointer to the enqueued skb after
    enqueue. However, both CAKE and TBF call consume_skb() on the original skb
    when splitting GSO packets, leading to a potential use-after-free in the
    parent. Fix this by avoiding dereferencing the skb pointer after enqueueing
    to the child.

    Signed-off-by: Toke Høiland-Jørgensen
    Signed-off-by: David S. Miller

    Toke Høiland-Jørgensen
     

26 Sep, 2018

1 commit

  • 86bd446b5   net: sched: rename qdisc_destroy() to qdisc_put() ... Browse Code »

    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
    Acked-by: Jiri Pirko
    Signed-off-by: David S. Miller

    Vlad Buslov
     

22 Dec, 2017

6 commits

22 Oct, 2017

1 commit

17 Oct, 2017

1 commit

07 Sep, 2017

1 commit

26 Aug, 2017

1 commit

  • 143976ce9   net_sched: remove tc class reference counting ... Browse Code »

    For TC classes, their ->get() and ->put() are always paired, and the
    reference counting is completely useless, because:

    1) For class modification and dumping paths, we already hold RTNL lock,
    so all of these ->get(),->change(),->put() are atomic.

    2) For filter bindiing/unbinding, we use other reference counter than
    this one, and they should have RTNL lock too.

    3) For ->qlen_notify(), it is special because it is called on ->enqueue()
    path, but we already hold qdisc tree lock there, and we hold this
    tree lock when graft or delete the class too, so it should not be gone
    or changed until we release the tree lock.

    Therefore, this patch removes ->get() and ->put(), but:

    1) Adds a new ->find() to find the pointer to a class by classid, no
    refcnt.

    2) Move the original class destroy upon the last refcnt into ->delete(),
    right after releasing tree lock. This is fine because the class is
    already removed from hash when holding the lock.

    For those who also use ->put() as ->unbind(), just rename them to reflect
    this change.

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

    WANG Cong
     

17 Aug, 2017

1 commit

  • 959466588   net_sched: call qlen_notify only if child qdisc is empty ... Browse Code »

    This callback is used for deactivating class in parent qdisc.
    This is cheaper to test queue length right here.

    Also this allows to catch draining screwed backlog and prevent
    second deactivation of already inactive parent class which will
    crash kernel for sure. Kernel with print warning at destruction
    of child qdisc where no packets but backlog is not zero.

    Signed-off-by: Konstantin Khlebnikov
    Signed-off-by: David S. Miller

    Konstantin Khlebnikov
     

07 Jun, 2017

1 commit

  • e25ea21ff   net: sched: introduce a TRAP control action ... Browse Code »

    There is need to instruct the HW offloaded path to push certain matched
    packets to cpu/kernel for further analysis. So this patch introduces a
    new TRAP control action to TC.

    For kernel datapath, this action does not make much sense. So with the
    same logic as in HW, new TRAP behaves similar to STOLEN. The skb is just
    dropped in the datapath (and virtually ejected to an upper level, which
    does not exist in case of kernel).

    Signed-off-by: Jiri Pirko
    Reviewed-by: Yotam Gigi
    Reviewed-by: Andrew Lunn
    Signed-off-by: David S. Miller

    Jiri Pirko
     

18 May, 2017

2 commits

  • 6529eaba3   net: sched: introduce tcf block infractructure ... Browse Code »

    Currently, the filter chains are direcly put into the private structures
    of qdiscs. In order to be able to have multiple chains per qdisc and to
    allow filter chains sharing among qdiscs, there is a need for common
    object that would hold the chains. This introduces such object and calls
    it "tcf_block".

    Helpers to get and put the blocks are provided to be called from
    individual qdisc code. Also, the original filter_list pointers are left
    in qdisc privs to allow the entry into tcf_block processing without any
    added overhead of possible multiple pointer dereference on fast path.

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

    Jiri Pirko
     
  • 87d83093b   net: sched: move tc_classify function to cls_api.c ... Browse Code »

    Move tc_classify function to cls_api.c where it belongs, rename it to
    fit the namespace.

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

    Jiri Pirko
     

14 Apr, 2017

1 commit

13 Mar, 2017

1 commit

  • 49b499718   net: sched: make default fifo qdiscs appear in the dump ... Browse Code »

    The original reason [1] for having hidden qdiscs (potential scalability
    issues in qdisc_match_from_root() with single linked list in case of large
    amount of qdiscs) has been invalidated by 59cc1f61f0 ("net: sched: convert
    qdisc linked list to hashtable").

    This allows us for bringing more clarity and determinism into the dump by
    making default pfifo qdiscs visible.

    We're not turning this on by default though, at it was deemed [2] too
    intrusive / unnecessary change of default behavior towards userspace.
    Instead, TCA_DUMP_INVISIBLE netlink attribute is introduced, which allows
    applications to request complete qdisc hierarchy dump, including the
    ones that have always been implicit/invisible.

    Singleton noop_qdisc stays invisible, as teaching the whole infrastructure
    about singletons would require quite some surgery with very little gain
    (seeing no qdisc or seeing noop qdisc in the dump is probably setting
    the same user expectation).

    [1] http://lkml.kernel.org/r/1460732328.10638.74.camel@edumazet-glaptop3.roam.corp.google.com
    [2] http://lkml.kernel.org/r/20161021.105935.1907696543877061916.davem@davemloft.net

    Signed-off-by: Jiri Kosina
    Signed-off-by: David S. Miller

    Jiri Kosina
     

06 Dec, 2016

1 commit

  • 1c0d32fde   net_sched: gen_estimator: complete rewrite of rate estimators ... Browse Code »

    1) Old code was hard to maintain, due to complex lock chains.
    (We probably will be able to remove some kfree_rcu() in callers)

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

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

    In this rewrite :

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

    - Each estimator has its own timer.

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

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

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

    - xt_rateest_mt() no longer has to grab a spinlock.
    (In the future, xt_rateest_tg() could be switched to per cpu counters)

    Signed-off-by: Eric Dumazet
    Signed-off-by: David S. Miller

    Eric Dumazet
     

23 Sep, 2016

1 commit

26 Jun, 2016

1 commit

  • 520ac30f4   net_sched: drop packets after root qdisc lock is released ... Browse Code »

    Qdisc performance suffers when packets are dropped at enqueue()
    time because drops (kfree_skb()) are done while qdisc lock is held,
    delaying a dequeue() draining the queue.

    Nominal throughput can be reduced by 50 % when this happens,
    at a time we would like the dequeue() to proceed as fast as possible.

    Even FQ is vulnerable to this problem, while one of FQ goals was
    to provide some flow isolation.

    This patch adds a 'struct sk_buff **to_free' parameter to all
    qdisc->enqueue(), and in qdisc_drop() helper.

    I measured a performance increase of up to 12 %, but this patch
    is a prereq so that future batches in enqueue() can fly.

    Signed-off-by: Eric Dumazet
    Acked-by: Jesper Dangaard Brouer
    Signed-off-by: David S. Miller

    Eric Dumazet
     

11 Jun, 2016

1 commit

  • 1578b0a5e   Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net ... Browse Code »

    Conflicts:
    net/sched/act_police.c
    net/sched/sch_drr.c
    net/sched/sch_hfsc.c
    net/sched/sch_prio.c
    net/sched/sch_red.c
    net/sched/sch_tbf.c

    In net-next the drop methods of the packet schedulers got removed, so
    the bug fixes to them in 'net' are irrelevant.

    A packet action unload crash fix conflicts with the addition of the
    new firstuse timestamp.

    Signed-off-by: David S. Miller

    David S. Miller
     

09 Jun, 2016

2 commits

08 Jun, 2016

1 commit

  • edb09eb17   net: sched: do not acquire qdisc spinlock in qdisc/class stats dump ... Browse Code »

    Large tc dumps (tc -s {qdisc|class} sh dev ethX) done by Google BwE host
    agent [1] are problematic at scale :

    For each qdisc/class found in the dump, we currently lock the root qdisc
    spinlock in order to get stats. Sampling stats every 5 seconds from
    thousands of HTB classes is a challenge when the root qdisc spinlock is
    under high pressure. Not only the dumps take time, they also slow
    down the fast path (queue/dequeue packets) by 10 % to 20 % in some cases.

    An audit of existing qdiscs showed that sch_fq_codel is the only qdisc
    that might need the qdisc lock in fq_codel_dump_stats() and
    fq_codel_dump_class_stats()

    In v2 of this patch, I now use the Qdisc running seqcount to provide
    consistent reads of packets/bytes counters, regardless of 32/64 bit arches.

    I also changed rate estimators to use the same infrastructure
    so that they no longer need to lock root qdisc lock.

    [1]
    http://static.googleusercontent.com/media/research.google.com/en//pubs/archive/43838.pdf

    Signed-off-by: Eric Dumazet
    Cc: Cong Wang
    Cc: Jamal Hadi Salim
    Cc: John Fastabend
    Cc: Kevin Athey
    Cc: Xiaotian Pei
    Signed-off-by: David S. Miller

    Eric Dumazet
     

01 Mar, 2016

2 commits

  • 2ccccf5fb   net_sched: update hierarchical backlog too ... Browse Code »

    When the bottom qdisc decides to, for example, drop some packet,
    it calls qdisc_tree_decrease_qlen() to update the queue length
    for all its ancestors, we need to update the backlog too to
    keep the stats on root qdisc accurate.

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

    WANG Cong
     
  • 86a7996cc   net_sched: introduce qdisc_replace() helper ... Browse Code »

    Remove nearly duplicated code and prepare for the following patch.

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

    WANG Cong
     

28 Aug, 2015

1 commit

  • 3b3ae8802   net: sched: consolidate tc_classify{,_compat} ... Browse Code »

    For classifiers getting invoked via tc_classify(), we always need an
    extra function call into tc_classify_compat(), as both are being
    exported as symbols and tc_classify() itself doesn't do much except
    handling of reclassifications when tp->classify() returned with
    TC_ACT_RECLASSIFY.

    CBQ and ATM are the only qdiscs that directly call into tc_classify_compat(),
    all others use tc_classify(). When tc actions are being configured
    out in the kernel, tc_classify() effectively does nothing besides
    delegating.

    We could spare this layer and consolidate both functions. pktgen on
    single CPU constantly pushing skbs directly into the netif_receive_skb()
    path with a dummy classifier on ingress qdisc attached, improves
    slightly from 22.3Mpps to 23.1Mpps.

    Signed-off-by: Daniel Borkmann
    Acked-by: Alexei Starovoitov
    Signed-off-by: David S. Miller

    Daniel Borkmann
     

16 Jul, 2015

1 commit

  • 40bdc5360   pkt_sched: sch_qfq: remove unused member of struct qfq_sched ... Browse Code »

    The member (u32) "num_active_agg" of struct qfq_sched has been unused
    since its introduction in 462dbc9101acd38e92eda93c0726857517a24bbd
    "pkt_sched: QFQ Plus: fair-queueing service at DRR cost" and (AFAICT)
    there is no active plan to use it; this removes the member.

    Signed-off-by: Andrea Parri
    Acked-by: Paolo Valente
    Signed-off-by: David S. Miller

    Andrea Parri
     

22 Jun, 2015

1 commit

30 Sep, 2014

1 commit