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  1. 09 10月, 2017 20 次提交
  3. 08 10月, 2017 20 次提交
    • D
      Merge branch 'bpf-obj-name-misc' · c9f766bc
      由 David S. Miller 提交于 
      Martin KaFai Lau says:

====================
bpf: Misc improvements and a new usage on bpf obj name

The first two patches make improvements on the bpf obj name.

The last patch adds the prog name to kallsyms.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      c9f766bc
    • M
      bpf: Append prog->aux->name in bpf_get_prog_name() · 368211fb
      由 Martin KaFai Lau 提交于 
      This patch makes the bpf_prog's name available
in kallsyms.

The new format is bpf_prog_tag[_name].

Sample kallsyms from running selftests/bpf/test_progs:
[root@arch-fb-vm1 ~]# egrep ' bpf_prog_[0-9a-fA-F]{16}' /proc/kallsyms
ffffffffa0048000 t bpf_prog_dabf0207d1992486_test_obj_id
ffffffffa0038000 t bpf_prog_a04f5eef06a7f555__123456789ABCDE
ffffffffa0050000 t bpf_prog_a04f5eef06a7f555
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      368211fb
    • M
      bpf: Use char in prog and map name · 067cae47
      由 Martin KaFai Lau 提交于 
      Instead of u8, use char for prog and map name.  It can avoid the
userspace tool getting compiler's signess warning.  The
bpf_prog_aux, bpf_map, bpf_attr, bpf_prog_info and
bpf_map_info are changed.
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      067cae47
    • M
      bpf: Change bpf_obj_name_cpy() to better ensure map's name is init by 0 · 473d9734
      由 Martin KaFai Lau 提交于 
      During get_info_by_fd, the prog/map name is memcpy-ed.  It depends
on the prog->aux->name and map->name to be zero initialized.

bpf_prog_aux is easy to guarantee that aux->name is zero init.

The name in bpf_map may be harder to be guaranteed in the future when
new map type is added.

Hence, this patch makes bpf_obj_name_cpy() to always zero init
the prog/map name.
Suggested-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      473d9734
    • W
      ip_gre: check packet length and mtu correctly in erspan tx · f192970d
      由 William Tu 提交于 
      Similarly to early patch for erspan_xmit(), the ARPHDR_ETHER device
is the length of the whole ether packet.  So skb->len should subtract
the dev->hard_header_len.

Fixes: 1a66a836 ("gre: add collect_md mode to ERSPAN tunnel")
Fixes: 84e54fe0 ("gre: introduce native tunnel support for ERSPAN")
Signed-off-by: NWilliam Tu <u9012063@gmail.com>
Cc: Xin Long <lucien.xin@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Reviewed-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f192970d
    • L
      net: phonet: mark phonet_protocol as const · 548ec114
      由 Lin Zhang 提交于 
      The phonet_protocol structs don't need to be written by anyone and
so can be marked as const.
Signed-off-by: NLin Zhang <xiaolou4617@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      548ec114
    • L
      net: phonet: mark header_ops as const · 64237470
      由 Lin Zhang 提交于 
      Signed-off-by: NLin Zhang <xiaolou4617@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      64237470
    • D
      Merge branch 'bpf-perf-time-helpers' · a1d753d2
      由 David S. Miller 提交于 
      Yonghong Song says:

====================
bpf: add two helpers to read perf event enabled/running time

Hardware pmu counters are limited resources. When there are more
pmu based perf events opened than available counters, kernel will
multiplex these events so each event gets certain percentage
(but not 100%) of the pmu time. In case that multiplexing happens,
the number of samples or counter value will not reflect the
case compared to no multiplexing. This makes comparison between
different runs difficult.

Typically, the number of samples or counter value should be
normalized before comparing to other experiments. The typical
normalization is done like:
  normalized_num_samples = num_samples * time_enabled / time_running
  normalized_counter_value = counter_value * time_enabled / time_running
where time_enabled is the time enabled for event and time_running is
the time running for event since last normalization.

This patch set implements two helper functions.
The helper bpf_perf_event_read_value reads counter/time_enabled/time_running
for perf event array map. The helper bpf_perf_prog_read_value read
counter/time_enabled/time_running for bpf prog with type BPF_PROG_TYPE_PERF_EVENT.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a1d753d2
    • Y
      bpf: add a test case for helper bpf_perf_prog_read_value · 81b9cf80
      由 Yonghong Song 提交于 
      The bpf sample program trace_event is enhanced to use the new
helper to print out enabled/running time.
Signed-off-by: NYonghong Song <yhs@fb.com>
Acked-by: NAlexei Starovoitov <ast@fb.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      81b9cf80
    • Y
      bpf: add helper bpf_perf_prog_read_value · 4bebdc7a
      由 Yonghong Song 提交于 
      This patch adds helper bpf_perf_prog_read_cvalue for perf event based bpf
programs, to read event counter and enabled/running time.
The enabled/running time is accumulated since the perf event open.

The typical use case for perf event based bpf program is to attach itself
to a single event. In such cases, if it is desirable to get scaling factor
between two bpf invocations, users can can save the time values in a map,
and use the value from the map and the current value to calculate
the scaling factor.
Signed-off-by: NYonghong Song <yhs@fb.com>
Acked-by: NAlexei Starovoitov <ast@fb.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      4bebdc7a
    • Y
      bpf: add a test case for helper bpf_perf_event_read_value · 020a32d9
      由 Yonghong Song 提交于 
      The bpf sample program tracex6 is enhanced to use the new
helper to read enabled/running time as well.
Signed-off-by: NYonghong Song <yhs@fb.com>
Acked-by: NAlexei Starovoitov <ast@fb.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      020a32d9
    • Y
      bpf: add helper bpf_perf_event_read_value for perf event array map · 908432ca
      由 Yonghong Song 提交于 
      Hardware pmu counters are limited resources. When there are more
pmu based perf events opened than available counters, kernel will
multiplex these events so each event gets certain percentage
(but not 100%) of the pmu time. In case that multiplexing happens,
the number of samples or counter value will not reflect the
case compared to no multiplexing. This makes comparison between
different runs difficult.

Typically, the number of samples or counter value should be
normalized before comparing to other experiments. The typical
normalization is done like:
  normalized_num_samples = num_samples * time_enabled / time_running
  normalized_counter_value = counter_value * time_enabled / time_running
where time_enabled is the time enabled for event and time_running is
the time running for event since last normalization.

This patch adds helper bpf_perf_event_read_value for kprobed based perf
event array map, to read perf counter and enabled/running time.
The enabled/running time is accumulated since the perf event open.
To achieve scaling factor between two bpf invocations, users
can can use cpu_id as the key (which is typical for perf array usage model)
to remember the previous value and do the calculation inside the
bpf program.
Signed-off-by: NYonghong Song <yhs@fb.com>
Acked-by: NAlexei Starovoitov <ast@fb.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      908432ca
    • Y
      bpf: perf event change needed for subsequent bpf helpers · 97562633
      由 Yonghong Song 提交于 
      This patch does not impact existing functionalities.
It contains the changes in perf event area needed for
subsequent bpf_perf_event_read_value and
bpf_perf_prog_read_value helpers.
Signed-off-by: NYonghong Song <yhs@fb.com>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      97562633
    • A
      ip_tunnel: add mpls over gre support · bdc47641
      由 Amine Kherbouche 提交于 
      This commit introduces the MPLSoGRE support (RFC 4023), using ip tunnel
API by simply adding ipgre_tunnel_encap_(add|del)_mpls_ops() and the new
tunnel type TUNNEL_ENCAP_MPLS.
Signed-off-by: NAmine Kherbouche <amine.kherbouche@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      bdc47641
    • D
      Merge branch 'fib6-rcu' · 2af48d43
      由 David S. Miller 提交于 
      Wei Wang says:

====================
ipv6: replace rwlock with rcu and spinlock in fib6 table

Currently, fib6 table is protected by rwlock. During route lookup,
reader lock is taken and during route insertion, deletion or
modification, writer lock is taken. This is a very inefficient
implementation because the fastpath always has to do the operation
to grab the reader lock.
According to my latest syn flood test on an iota ivybridage machine
with 2 10G mlx nics bonded together, each with 8 rx queues on 2 NUMA
nodes, and with the upstream net-next kernel:
ipv4 stack can handle around 4.2Mpps
ipv6 stack can handle around 1.3Mpps

In order to close the gap of the performance number between ipv4
and ipv6 stack, this patch series tries to get rid of the usage of
the rwlock and replace it with rcu and spinlock protection. This will
greatly speed up the fastpath performance as it only needs to hold
rcu which is much less expensive than grabbing the reader lock. It
also makes ipv6 fib implementation more consistent with ipv4.

In order to be able to replace the current rwlock with rcu and
spinlock, some preparation work is needed:
Patch 1-8 introduces a per-route hash table (protected by rcu and a
different spinlock) to store all cached routes created by pmtu and ip
redirect under its main route. This makes the main fib6 tree only
contain static routes.
Patch 9-14 prepares all the reader path to be ready to tolerate
concurrent writer.
Patch 15 finally does the rwlock to rcu and spinlock conversion.
Patch 16 takes care of rt6_stats.

After this patch series, in the same syn flood test,
ipv6 stack can now handle around 3.5Mpps compared to previous 1.3Mpps
in my test setup.

After this patch series, there are still some improvements that should
be done in ipv6 stack:
1. During route lookup, dst_use() is called everytime on the selected
route to update dst->__use and dst->lastuse. This dirties the cacheline
and causes extra cacheline miss and should be avoided.
2. when no route is found in the current table, net->ip6.ipv6_null_entry
is used and refcnt is taken on it. As there is no pcpu cache for this
specific route, frequent change on the refcnt for this route causes
quite some cacheline misses.
And to make things worse, if CONFIG_IPV6_MULTIPLE_TABLES is defined,
output path route lookup always starts with local table first and
guarantees to hit net->ipv6.ip6_null_entry before continuing to do
lookup in the main table.
These operations on net->ipv6.ip6_null_entry could potentially be
avoided.
3. ipv6 input path route lookup grabs refcnt on dst. This is different
from ipv4. We could potentially change this behavior to let ipv6 input
path route lookup not to grab refcnt on dst. However, it does not give
us much performance boost as we currently have pcpu route cache for
input path as well in ipv6. But this work probably is still worth doing
to unify ipv6 and ipv4 route lookup behavior.

The above issues will be addressed separately after this patch series
has been accepted.

This is a joint work with Martin KaFai Lau and Eric Dumazet. And many
many thanks to them for their inspiring ideas and big big code review
efforts.
====================
Reviewed-by: NEric Dumazet <edumazet@google.com>
Reviewed-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2af48d43
    • W
      ipv6: take care of rt6_stats · 81eb8447
      由 Wei Wang 提交于 
      Currently, most of the rt6_stats are not hooked up correctly. As the
last part of this patch series, hook up all existing rt6_stats and add
one new stat fib_rt_uncache to indicate the number of routes in the
uncached list.
For details of the stats, please refer to the comments added in
include/net/ip6_fib.h.

Note: fib_rt_alloc and fib_rt_uncache are not guaranteed to be modified
under a lock. So atomic_t is used for them.
Signed-off-by: NWei Wang <weiwan@google.com>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      81eb8447
    • W
      ipv6: replace rwlock with rcu and spinlock in fib6_table · 66f5d6ce
      由 Wei Wang 提交于 
      With all the preparation work before, we are now ready to replace rwlock
with rcu and spinlock in fib6_table.
That means now all fib6_node in fib6_table are protected by rcu. And
when freeing fib6_node, call_rcu() is used to wait for the rcu grace
period before releasing the memory.
When accessing fib6_node, corresponding rcu APIs need to be used.
And all previous sessions protected by the write lock will now be
protected by the spin lock per table.
All previous sessions protected by read lock will now be protected by
rcu_read_lock().

A couple of things to note here:
1. As part of the work of replacing rwlock with rcu, the linked list of
fn->leaf now has to be rcu protected as well. So both fn->leaf and
rt->dst.rt6_next are now __rcu tagged and corresponding rcu APIs are
used when manipulating them.

2. For fn->rr_ptr, first of all, it also needs to be rcu protected now
and is tagged with __rcu and rcu APIs are used in corresponding places.
Secondly, fn->rr_ptr is changed in rt6_select() which is a reader
thread. This makes the issue a bit complicated. We think a valid
solution for it is to let rt6_select() grab the tb6_lock if it decides
to change it. As it is not in the normal operation and only happens when
there is no valid neighbor cache for the route, we think the performance
impact should be low.

3. fib6_walk_continue() has to be called with tb6_lock held even in the
route dumping related functions, e.g. inet6_dump_fib(),
fib6_tables_dump() and ipv6_route_seq_ops. It is because
fib6_walk_continue() makes modifications to the walker structure, and so
are fib6_repair_tree() and fib6_del_route(). In order to do proper
syncing between them, we need to let fib6_walk_continue() hold the lock.
We may be able to do further improvement on the way we do the tree walk
to get rid of the need for holding the spin lock. But not for now.

4. When fib6_del_route() removes a route from the tree, we no longer
mark rt->dst.rt6_next to NULL to make simultaneous reader be able to
further traverse the list with rcu. However, rt->dst.rt6_next is only
valid within this same rcu period. No one should access it later.

5. All the operation of atomic_inc(rt->rt6i_ref) is changed to be
performed before we publish this route (either by linking it to fn->leaf
or insert it in the list pointed by fn->leaf) just to be safe because as
soon as we publish the route, some read thread will be able to access it.
Signed-off-by: NWei Wang <weiwan@google.com>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      66f5d6ce
    • W
      ipv6: add key length check into rt6_select() · 17ecf590
      由 Wei Wang 提交于 
      After rwlock is replaced with rcu and spinlock, fib6_lookup() could
potentially return an intermediate node if other thread is doing
fib6_del() on a route which is the only route on the node so that
fib6_repair_tree() will be called on this node and potentially assigns
fn->leaf to the its child's fn->leaf.

In order to detect this situation in rt6_select(), we have to check if
fn->fn_bit is consistent with the key length stored in the route. And
depending on if the fn is in the subtree or not, the key is either
rt->rt6i_dst or rt->rt6i_src.
If any inconsistency is found, that means the node no longer holds valid
routes in it. So net->ipv6.ip6_null_entry is returned.
Signed-off-by: NWei Wang <weiwan@google.com>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      17ecf590
    • W
      ipv6: check fn->leaf before it is used · 8d1040e8
      由 Wei Wang 提交于 
      If rwlock is replaced with rcu and spinlock, it is possible that the
reader thread will see fn->leaf as NULL in the following scenarios:
1. fib6_add() is in progress and we have already inserted a new node but
not yet inserted the route.
2. fib6_del_route() is in progress and we have already set fn->leaf to
NULL but not yet freed the node because of rcu grace period.

This patch makes sure all the reader threads check fn->leaf first before
using it. And together with later patch to grab rcu_read_lock() and
rcu_dereference() fn->leaf, it makes sure reader threads are safe when
accessing fn->leaf.
Signed-off-by: NWei Wang <weiwan@google.com>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      8d1040e8
    • W
      ipv6: update fn_sernum after route is inserted to tree · bbd63f06
      由 Wei Wang 提交于 
      fib6_add() logic currently calls fib6_add_1() to figure out what node
should be used for the newly added route and then call
fib6_add_rt2node() to insert the route to the node.
And during the call of fib6_add_1(), fn_sernum is updated for all nodes
that share the same prefix as the new route.
This does not have issue in the current code because reader thread will
not be able to access the tree while writer thread is inserting new
route to it. However, it is not the case once we transition to use RCU.
Reader thread could potentially see the new fn_sernum before the new
route is inserted. As a result, reader thread's route lookup will return
a stale route with the new fn_sernum.

In order to solve this issue, we remove all the update of fn_sernum in
fib6_add_1(), and instead, introduce a new function that updates fn_sernum
for all related nodes and call this functions once the route is
successfully inserted to the tree.
Also, smp_wmb() is used after a route is successfully inserted into the
fib tree and right before the updated of fn->sernum. And smp_rmb() is
used right after fn->sernum is accessed in rt6_get_cookie_safe(). This
is to guarantee that when the reader thread sees the new fn->sernum, the
new route is already inserted in the tree in memory.
Signed-off-by: NWei Wang <weiwan@google.com>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      bbd63f06