Eric Lee / smarc-fsl-linux-kernel

25 Feb, 2018

1 commit

  • 6e12516df   netfilter: xt_RATEEST: acquire xt_rateest_mutex for hash insert ... Browse Code »

    commit 7dc68e98757a8eccf8ca7a53a29b896f1eef1f76 upstream.

    rateest_hash is supposed to be protected by xt_rateest_mutex,
    and, as suggested by Eric, lookup and insert should be atomic,
    so we should acquire the xt_rateest_mutex once for both.

    So introduce a non-locking helper for internal use and keep the
    locking one for external.

    Reported-by:
    Fixes: 5859034d7eb8 ("[NETFILTER]: x_tables: add RATEEST target")
    Signed-off-by: Cong Wang
    Reviewed-by: Florian Westphal
    Reviewed-by: Eric Dumazet
    Signed-off-by: Pablo Neira Ayuso
    Signed-off-by: Greg Kroah-Hartman

    Cong Wang
     

10 Jan, 2017

1 commit

  • ec2318904   xtables: extend matches and targets with .usersize ... Browse Code »

    In matches and targets that define a kernel-only tail to their
    xt_match and xt_target data structs, add a field .usersize that
    specifies up to where data is to be shared with userspace.

    Performed a search for comment "Used internally by the kernel" to find
    relevant matches and targets. Manually inspected the structs to derive
    a valid offsetof.

    Signed-off-by: Willem de Bruijn
    Signed-off-by: Pablo Neira Ayuso

    Willem de Bruijn
     

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

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
     

30 Sep, 2014

1 commit

  • 22e0f8b93   net: sched: make bstats per cpu and estimator RCU safe ... Browse Code »

    In order to run qdisc's without locking statistics and estimators
    need to be handled correctly.

    To resolve bstats make the statistics per cpu. And because this is
    only needed for qdiscs that are running without locks which is not
    the case for most qdiscs in the near future only create percpu
    stats when qdiscs set the TCQ_F_CPUSTATS flag.

    Next because estimators use the bstats to calculate packets per
    second and bytes per second the estimator code paths are updated
    to use the per cpu statistics.

    Signed-off-by: John Fastabend
    Signed-off-by: David S. Miller

    John Fastabend
     

28 Feb, 2013

1 commit

  • b67bfe0d4   hlist: drop the node parameter from iterators ... Browse Code »

    I'm not sure why, but the hlist for each entry iterators were conceived

    list_for_each_entry(pos, head, member)

    The hlist ones were greedy and wanted an extra parameter:

    hlist_for_each_entry(tpos, pos, head, member)

    Why did they need an extra pos parameter? I'm not quite sure. Not only
    they don't really need it, it also prevents the iterator from looking
    exactly like the list iterator, which is unfortunate.

    Besides the semantic patch, there was some manual work required:

    - Fix up the actual hlist iterators in linux/list.h
    - Fix up the declaration of other iterators based on the hlist ones.
    - A very small amount of places were using the 'node' parameter, this
    was modified to use 'obj->member' instead.
    - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
    properly, so those had to be fixed up manually.

    The semantic patch which is mostly the work of Peter Senna Tschudin is here:

    @@
    iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

    type T;
    expression a,c,d,e;
    identifier b;
    statement S;
    @@

    -T b;

    [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
    [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
    [akpm@linux-foundation.org: checkpatch fixes]
    [akpm@linux-foundation.org: fix warnings]
    [akpm@linux-foudnation.org: redo intrusive kvm changes]
    Tested-by: Peter Senna Tschudin
    Acked-by: Paul E. McKenney
    Signed-off-by: Sasha Levin
    Cc: Wu Fengguang
    Cc: Marcelo Tosatti
    Cc: Gleb Natapov
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Sasha Levin
     

21 Jul, 2011

1 commit

12 Jun, 2010

1 commit

  • c7de2cf05   pkt_sched: gen_kill_estimator() rcu fixes ... Browse Code »

    gen_kill_estimator() API is incomplete or not well documented, since
    caller should make sure an RCU grace period is respected before
    freeing stats_lock.

    This was partially addressed in commit 5d944c640b4
    (gen_estimator: deadlock fix), but same problem exist for all
    gen_kill_estimator() users, if lock they use is not already RCU
    protected.

    A code review shows xt_RATEEST.c, act_api.c, act_police.c have this
    problem. Other are ok because they use qdisc lock, already RCU
    protected.

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

    Eric Dumazet
     

12 May, 2010

1 commit

20 Apr, 2010

1 commit

30 Mar, 2010

1 commit

  • 5a0e3ad6a   include cleanup: Update gfp.h and slab.h includes to prepare for breaking implic… ... Browse Code »

    …it slab.h inclusion from percpu.h

    percpu.h is included by sched.h and module.h and thus ends up being
    included when building most .c files. percpu.h includes slab.h which
    in turn includes gfp.h making everything defined by the two files
    universally available and complicating inclusion dependencies.

    percpu.h -> slab.h dependency is about to be removed. Prepare for
    this change by updating users of gfp and slab facilities include those
    headers directly instead of assuming availability. As this conversion
    needs to touch large number of source files, the following script is
    used as the basis of conversion.

    http://userweb.kernel.org/~tj/misc/slabh-sweep.py

    The script does the followings.

    * Scan files for gfp and slab usages and update includes such that
    only the necessary includes are there. ie. if only gfp is used,
    gfp.h, if slab is used, slab.h.

    * When the script inserts a new include, it looks at the include
    blocks and try to put the new include such that its order conforms
    to its surrounding. It's put in the include block which contains
    core kernel includes, in the same order that the rest are ordered -
    alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
    doesn't seem to be any matching order.

    * If the script can't find a place to put a new include (mostly
    because the file doesn't have fitting include block), it prints out
    an error message indicating which .h file needs to be added to the
    file.

    The conversion was done in the following steps.

    1. The initial automatic conversion of all .c files updated slightly
    over 4000 files, deleting around 700 includes and adding ~480 gfp.h
    and ~3000 slab.h inclusions. The script emitted errors for ~400
    files.

    2. Each error was manually checked. Some didn't need the inclusion,
    some needed manual addition while adding it to implementation .h or
    embedding .c file was more appropriate for others. This step added
    inclusions to around 150 files.

    3. The script was run again and the output was compared to the edits
    from #2 to make sure no file was left behind.

    4. Several build tests were done and a couple of problems were fixed.
    e.g. lib/decompress_*.c used malloc/free() wrappers around slab
    APIs requiring slab.h to be added manually.

    5. The script was run on all .h files but without automatically
    editing them as sprinkling gfp.h and slab.h inclusions around .h
    files could easily lead to inclusion dependency hell. Most gfp.h
    inclusion directives were ignored as stuff from gfp.h was usually
    wildly available and often used in preprocessor macros. Each
    slab.h inclusion directive was examined and added manually as
    necessary.

    6. percpu.h was updated not to include slab.h.

    7. Build test were done on the following configurations and failures
    were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
    distributed build env didn't work with gcov compiles) and a few
    more options had to be turned off depending on archs to make things
    build (like ipr on powerpc/64 which failed due to missing writeq).

    * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
    * powerpc and powerpc64 SMP allmodconfig
    * sparc and sparc64 SMP allmodconfig
    * ia64 SMP allmodconfig
    * s390 SMP allmodconfig
    * alpha SMP allmodconfig
    * um on x86_64 SMP allmodconfig

    8. percpu.h modifications were reverted so that it could be applied as
    a separate patch and serve as bisection point.

    Given the fact that I had only a couple of failures from tests on step
    6, I'm fairly confident about the coverage of this conversion patch.
    If there is a breakage, it's likely to be something in one of the arch
    headers which should be easily discoverable easily on most builds of
    the specific arch.

    Signed-off-by: Tejun Heo <tj@kernel.org>
    Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

    Tejun Heo
     

25 Mar, 2010

3 commits

04 Jan, 2010

1 commit

18 Aug, 2009

1 commit

  • c1a8f1f1c   net: restore gnet_stats_basic to previous definition ... Browse Code »

    In 5e140dfc1fe87eae27846f193086724806b33c7d "net: reorder struct Qdisc
    for better SMP performance" the definition of struct gnet_stats_basic
    changed incompatibly, as copies of this struct are shipped to
    userland via netlink.

    Restoring old behavior is not welcome, for performance reason.

    Fix is to use a private structure for kernel, and
    teach gnet_stats_copy_basic() to convert from kernel to user land,
    using legacy structure (struct gnet_stats_basic)

    Based on a report and initial patch from Michael Spang.

    Reported-by: Michael Spang
    Signed-off-by: Eric Dumazet
    Signed-off-by: David S. Miller

    Eric Dumazet
     

08 Oct, 2008

5 commits

14 Apr, 2008

1 commit

29 Jan, 2008

3 commits