[ Upstream commit d6dbbb11247c71203785a2c9da474c36f4b19eae ]
NAPI threads can keep polling packets under load. Currently it is only
calling cond_resched() before repolling, but it is not sufficient to
clear out the holdout of RCU tasks, which prevent BPF tracing programs
from detaching for long period. This can be reproduced easily with
following set up:
ip netns add test1
ip netns add test2
ip -n test1 link add veth1 type veth peer name veth2 netns test2
ip -n test1 link set veth1 up
ip -n test1 link set lo up
ip -n test2 link set veth2 up
ip -n test2 link set lo up
ip -n test1 addr add 192.168.1.2/31 dev veth1
ip -n test1 addr add 1.1.1.1/32 dev lo
ip -n test2 addr add 192.168.1.3/31 dev veth2
ip -n test2 addr add 2.2.2.2/31 dev lo
ip -n test1 route add default via 192.168.1.3
ip -n test2 route add default via 192.168.1.2
for i in `seq 10 210`; do
for j in `seq 10 210`; do
ip netns exec test2 iptables -I INPUT -s 3.3.$i.$j -p udp --dport 5201
done
done
ip netns exec test2 ethtool -K veth2 gro on
ip netns exec test2 bash -c 'echo 1 > /sys/class/net/veth2/threaded'
ip netns exec test1 ethtool -K veth1 tso off
Then run an iperf3 client/server and a bpftrace script can trigger it:
ip netns exec test2 iperf3 -s -B 2.2.2.2 >/dev/null&
ip netns exec test1 iperf3 -c 2.2.2.2 -B 1.1.1.1 -u -l 1500 -b 3g -t 100 >/dev/null&
bpftrace -e 'kfunc:__napi_poll{@=count();} interval:s:1{exit();}'
Report RCU quiescent states periodically will resolve the issue.
Fixes: 29863d41bb ("net: implement threaded-able napi poll loop support")
Reviewed-by: Jesper Dangaard Brouer <hawk@kernel.org>
Signed-off-by: Yan Zhai <yan@cloudflare.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Link: https://lore.kernel.org/r/4c3b0d3f32d3b18949d75b18e5e1d9f13a24f025.1710877680.git.yan@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d09486a04f5da0a812c26217213b89a3b1acf836 ]
Mark reports a BUG() when a net namespace is removed.
kernel BUG at net/core/dev.c:11520!
Physical interfaces moved outside of init_net get "refunded"
to init_net when that namespace disappears. The main interface
name may get overwritten in the process if it would have
conflicted. We need to also discard all conflicting altnames.
Recent fixes addressed ensuring that altnames get moved
with the main interface, which surfaced this problem.
Reported-by: Марк Коренберг <socketpair@gmail.com>
Link: https://lore.kernel.org/all/CAEmTpZFZ4Sv3KwqFOY2WKDHeZYdi0O7N5H1nTvcGp=SAEavtDg@mail.gmail.com/
Fixes: 7663d52209 ("net: check for altname conflicts when changing netdev's netns")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 24ab059d2ebd62fdccc43794796f6ffbabe49ebc ]
Some drivers might misbehave if TSO packets get too big.
GVE for instance uses a 16bit field in its TX descriptor,
and will do bad things if a packet is bigger than 2^16 bytes.
Linux TCP stack honors dev->gso_max_size, but there are
other ways for too big packets to reach an ndo_start_xmit()
handler : virtio_net, af_packet, GRO...
Add a generic check in gso_features_check() and fallback
to GSO when needed.
gso_max_size was added in the blamed commit.
Fixes: 82cc1a7a56 ("[NET]: Add per-connection option to set max TSO frame size")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20231219125331.4127498-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 024ee930cb3c9ae49e4266aee89cfde0ebb407e1 ]
Traffic redirected by bpf_redirect_peer() (used by recent CNIs like Cilium)
is not accounted for in the RX stats of supported devices (that is, veth
and netkit), confusing user space metrics collectors such as cAdvisor [0],
as reported by Youlun.
Fix it by calling dev_sw_netstats_rx_add() in skb_do_redirect(), to update
RX traffic counters. Devices that support ndo_get_peer_dev _must_ use the
@tstats per-CPU counters (instead of @lstats, or @dstats).
To make this more fool-proof, error out when ndo_get_peer_dev is set but
@tstats are not selected.
[0] Specifically, the "container_network_receive_{byte,packet}s_total"
counters are affected.
Fixes: 9aa1206e8f ("bpf: Add redirect_peer helper")
Reported-by: Youlun Zhang <zhangyoulun@bytedance.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Co-developed-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/20231114004220.6495-6-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 34d21de99cea9cb17967874313e5b0262527833c ]
Move {l,t,d}stats allocation to the core and let netdevs pick the stats
type they need. That way the driver doesn't have to bother with error
handling (allocation failure checking, making sure free happens in the
right spot, etc) - all happening in the core.
Co-developed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Cc: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20231114004220.6495-3-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Stable-dep-of: 024ee930cb3c ("bpf: Fix dev's rx stats for bpf_redirect_peer traffic")
Signed-off-by: Sasha Levin <sashal@kernel.org>
The altname nodes are currently not moved to the new netns
when netdevice itself moves:
[ ~]# ip netns add test
[ ~]# ip -netns test link add name eth0 type dummy
[ ~]# ip -netns test link property add dev eth0 altname some-name
[ ~]# ip -netns test link show dev some-name
2: eth0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether 1e:67:ed:19:3d:24 brd ff:ff:ff:ff:ff:ff
altname some-name
[ ~]# ip -netns test link set dev eth0 netns 1
[ ~]# ip link
...
3: eth0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether 02:40:88:62:ec:b8 brd ff:ff:ff:ff:ff:ff
altname some-name
[ ~]# ip li show dev some-name
Device "some-name" does not exist.
Remove them from the hash table when device is unlisted
and add back when listed again.
Fixes: 36fbf1e52b ("net: rtnetlink: add linkprop commands to add and delete alternative ifnames")
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Altnames are accessed under RCU (dev_get_by_name_rcu())
but freed by kfree() with no synchronization point.
Each node has one or two allocations (node and a variable-size
name, sometimes the name is netdev->name). Adding rcu_heads
here is a bit tedious. Besides most code which unlists the names
already has rcu barriers - so take the simpler approach of adding
synchronize_rcu(). Note that the one on the unregistration path
(which matters more) is removed by the next fix.
Fixes: ff92741270 ("net: introduce name_node struct to be used in hashlist")
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
It's currently possible to create an altname conflicting
with an altname or real name of another device by creating
it in another netns and moving it over:
[ ~]$ ip link add dev eth0 type dummy
[ ~]$ ip netns add test
[ ~]$ ip -netns test link add dev ethX netns test type dummy
[ ~]$ ip -netns test link property add dev ethX altname eth0
[ ~]$ ip -netns test link set dev ethX netns 1
[ ~]$ ip link
...
3: eth0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether 02:40:88:62:ec:b8 brd ff:ff:ff:ff:ff:ff
...
5: ethX: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether 26:b7:28:78:38:0f brd ff:ff:ff:ff:ff:ff
altname eth0
Create a macro for walking the altnames, this hopefully makes
it clearer that the list we walk contains only altnames.
Which is otherwise not entirely intuitive.
Fixes: 36fbf1e52b ("net: rtnetlink: add linkprop commands to add and delete alternative ifnames")
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
dev_get_valid_name() overwrites the netdev's name on success.
This makes it hard to use in prepare-commit-like fashion,
where we do validation first, and "commit" to the change
later.
Factor out a helper which lets us save the new name to a buffer.
Use it to fix the problem of notification on netns move having
incorrect name:
5: eth0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN group default
link/ether be:4d:58:f9:d5:40 brd ff:ff:ff:ff:ff:ff
6: eth1: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN group default
link/ether 1e:4a:34:36:e3:cd brd ff:ff:ff:ff:ff:ff
[ ~]# ip link set dev eth0 netns 1 name eth1
ip monitor inside netns:
Deleted inet eth0
Deleted inet6 eth0
Deleted 5: eth1: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN group default
link/ether be:4d:58:f9:d5:40 brd ff:ff:ff:ff:ff:ff new-netnsid 0 new-ifindex 7
Name is reported as eth1 in old netns for ifindex 5, already renamed.
Fixes: d90310243f ("net: device name allocation cleanups")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
syzbot uses panic_on_warn.
This means that the skb_dump() I added in the blamed commit are
not even called.
Rewrite this so that we get the needed skb dump before syzbot crashes.
Fixes: eeee4b77dc ("net: add more debug info in skb_checksum_help()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20231006173355.2254983-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Use bitmap_zalloc() and bitmap_free() instead of hand-writing them.
It is less verbose and it improves the type checking and semantic.
While at it, add missing header inclusion (should be bitops.h,
but with the above change it becomes bitmap.h).
Suggested-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20230911154534.4174265-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While looking at TC_ACT_* handling, the TC_ACT_CONSUMED is only handled in
sch_handle_ingress but not sch_handle_egress. This was added via cd11b16407
("net/tc: introduce TC_ACT_REINSERT.") and e5cf1baf92 ("act_mirred: use
TC_ACT_REINSERT when possible") and later got renamed into TC_ACT_CONSUMED
via 720f22fed8 ("net: sched: refactor reinsert action").
The initial work was targeted for ovs back then and only needed on ingress,
and the mirred action module also restricts it to only that. However, given
it's an API contract it would still make sense to make this consistent to
sch_handle_ingress and handle it on egress side in the same way, that is,
setting return code to "success" and returning NULL back to the caller as
otherwise an action module sitting on egress returning TC_ACT_CONSUMED could
lead to an UAF when untreated.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix a memory leak for the tc egress path with TC_ACT_{STOLEN,QUEUED,TRAP}:
[...]
unreferenced object 0xffff88818bcb4f00 (size 232):
comm "softirq", pid 0, jiffies 4299085078 (age 134.028s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 80 70 61 81 88 ff ff 00 41 31 14 81 88 ff ff ..pa.....A1.....
backtrace:
[<ffffffff9991b938>] kmem_cache_alloc_node+0x268/0x400
[<ffffffff9b3d9231>] __alloc_skb+0x211/0x2c0
[<ffffffff9b3f0c7e>] alloc_skb_with_frags+0xbe/0x6b0
[<ffffffff9b3bf9a9>] sock_alloc_send_pskb+0x6a9/0x870
[<ffffffff9b6b3f00>] __ip_append_data+0x14d0/0x3bf0
[<ffffffff9b6ba24e>] ip_append_data+0xee/0x190
[<ffffffff9b7e1496>] icmp_push_reply+0xa6/0x470
[<ffffffff9b7e4030>] icmp_reply+0x900/0xa00
[<ffffffff9b7e42e3>] icmp_echo.part.0+0x1a3/0x230
[<ffffffff9b7e444d>] icmp_echo+0xcd/0x190
[<ffffffff9b7e9566>] icmp_rcv+0x806/0xe10
[<ffffffff9b699bd1>] ip_protocol_deliver_rcu+0x351/0x3d0
[<ffffffff9b699f14>] ip_local_deliver_finish+0x2b4/0x450
[<ffffffff9b69a234>] ip_local_deliver+0x174/0x1f0
[<ffffffff9b69a4b2>] ip_sublist_rcv_finish+0x1f2/0x420
[<ffffffff9b69ab56>] ip_sublist_rcv+0x466/0x920
[...]
I was able to reproduce this via:
ip link add dev dummy0 type dummy
ip link set dev dummy0 up
tc qdisc add dev eth0 clsact
tc filter add dev eth0 egress protocol ip prio 1 u32 match ip protocol 1 0xff action mirred egress redirect dev dummy0
ping 1.1.1.1
<stolen>
After the fix, there are no kmemleak reports with the reproducer. This is
in line with what is also done on the ingress side, and from debugging the
skb_unref(skb) on dummy xmit and sch_handle_egress() side, it is visible
that these are two different skbs with both skb_unref(skb) as true. The two
seen skbs are due to mirred doing a skb_clone() internally as use_reinsert
is false in tcf_mirred_act() for egress. This was initially reported by Gal.
Fixes: e420bed025 ("bpf: Add fd-based tcx multi-prog infra with link support")
Reported-by: Gal Pressman <gal@nvidia.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/bdfc2640-8f65-5b56-4472-db8e2b161aab@nvidia.com
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since the xarray changes we mix returning valid ifindex and negative
errno in a single int returned from dev_index_reserve(). This depends
on the fact that ifindexes can't be negative. Otherwise we may insert
into the xarray and return a very large negative value. This in turn
may break ERR_PTR().
OvS is susceptible to this problem and lacking validation (fix posted
separately for net).
Reject negative ifindex explicitly. Add a warning because the input
validation is better handled by the caller.
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20230814205627.2914583-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Martin KaFai Lau says:
====================
pull-request: bpf-next 2023-08-03
We've added 54 non-merge commits during the last 10 day(s) which contain
a total of 84 files changed, 4026 insertions(+), 562 deletions(-).
The main changes are:
1) Add SO_REUSEPORT support for TC bpf_sk_assign from Lorenz Bauer,
Daniel Borkmann
2) Support new insns from cpu v4 from Yonghong Song
3) Non-atomically allocate freelist during prefill from YiFei Zhu
4) Support defragmenting IPv(4|6) packets in BPF from Daniel Xu
5) Add tracepoint to xdp attaching failure from Leon Hwang
6) struct netdev_rx_queue and xdp.h reshuffling to reduce
rebuild time from Jakub Kicinski
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (54 commits)
net: invert the netdevice.h vs xdp.h dependency
net: move struct netdev_rx_queue out of netdevice.h
eth: add missing xdp.h includes in drivers
selftests/bpf: Add testcase for xdp attaching failure tracepoint
bpf, xdp: Add tracepoint to xdp attaching failure
selftests/bpf: fix static assert compilation issue for test_cls_*.c
bpf: fix bpf_probe_read_kernel prototype mismatch
riscv, bpf: Adapt bpf trampoline to optimized riscv ftrace framework
libbpf: fix typos in Makefile
tracing: bpf: use struct trace_entry in struct syscall_tp_t
bpf, devmap: Remove unused dtab field from bpf_dtab_netdev
bpf, cpumap: Remove unused cmap field from bpf_cpu_map_entry
netfilter: bpf: Only define get_proto_defrag_hook() if necessary
bpf: Fix an array-index-out-of-bounds issue in disasm.c
net: remove duplicate INDIRECT_CALLABLE_DECLARE of udp[6]_ehashfn
docs/bpf: Fix malformed documentation
bpf: selftests: Add defrag selftests
bpf: selftests: Support custom type and proto for client sockets
bpf: selftests: Support not connecting client socket
netfilter: bpf: Support BPF_F_NETFILTER_IP_DEFRAG in netfilter link
...
====================
Link: https://lore.kernel.org/r/20230803174845.825419-1-martin.lau@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
struct netdev_rx_queue is touched in only a few places
and having it defined in netdevice.h brings in the dependency
on xdp.h, because struct xdp_rxq_info gets embedded in
struct netdev_rx_queue.
In prep for removal of xdp.h from netdevice.h move all
the netdev_rx_queue stuff to a new header.
We could technically break the new header up to avoid
the sysfs.h include but it's so rarely included it
doesn't seem to be worth it at this point.
Reviewed-by: Amritha Nambiar <amritha.nambiar@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Link: https://lore.kernel.org/r/20230803010230.1755386-3-kuba@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
When error happens in dev_xdp_attach(), it should have a way to tell
users the error message like the netlink approach.
To avoid breaking uapi, adding a tracepoint in bpf_xdp_link_attach() is
an appropriate way to notify users the error message.
Hence, bpf libraries are able to retrieve the error message by this
tracepoint, and then report the error message to users.
Signed-off-by: Leon Hwang <hffilwlqm@gmail.com>
Link: https://lore.kernel.org/r/20230801142621.7925-2-hffilwlqm@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Iterating over the netdev hash table for netlink dumps is hard.
Dumps are done in "chunks" so we need to save the position
after each chunk, so we know where to restart from. Because
netdevs are stored in a hash table we remember which bucket
we were in and how many devices we dumped.
Since we don't hold any locks across the "chunks" - devices may
come and go while we're dumping. If that happens we may miss
a device (if device is deleted from the bucket we were in).
We indicate to user space that this may have happened by setting
NLM_F_DUMP_INTR. User space is supposed to dump again (I think)
if it sees that. Somehow I doubt most user space gets this right..
To illustrate let's look at an example:
System state:
start: # [A, B, C]
del: B # [A, C]
with the hash table we may dump [A, B], missing C completely even
tho it existed both before and after the "del B".
Add an xarray and use it to allocate ifindexes. This way we
can iterate ifindexes in order, without the worry that we'll
skip one. We may still generate a dump of a state which "never
existed", for example for a set of values and sequence of ops:
System state:
start: # [A, B]
add: C # [A, C, B]
del: B # [A, C]
we may generate a dump of [A], if C got an index between A and B.
System has never been in such state. But I'm 90% sure that's perfectly
fine, important part is that we can't _miss_ devices which exist before
and after. User space which wants to mirror kernel's state subscribes
to notifications and does periodic dumps so it will know that C exists
from the notification about its creation or from the next dump
(next dump is _guaranteed_ to include C, if it doesn't get removed).
To avoid any perf regressions keep the hash table for now. Most
net namespaces have very few devices and microbenchmarking 1M lookups
on Skylake I get the following results (not counting loopback
to number of devs):
#devs | hash | xa | delta
2 | 18.3 | 20.1 | + 9.8%
16 | 18.3 | 20.1 | + 9.5%
64 | 18.3 | 26.3 | +43.8%
128 | 20.4 | 26.3 | +28.6%
256 | 20.0 | 26.4 | +32.1%
1024 | 26.6 | 26.7 | + 0.2%
8192 |541.3 | 33.5 | -93.8%
No surprises since the hash table has 256 entries.
The microbenchmark scans indexes in order, if the pattern is more
random xa starts to win at 512 devices already. But that's a lot
of devices, in practice.
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20230726185530.2247698-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
There are currently two paths that call remove_xps_queue():
1. __netif_set_xps_queue -> remove_xps_queue
2. clean_xps_maps -> remove_xps_queue_cpu -> remove_xps_queue
There is no need to check dev_maps in remove_xps_queue() because
dev_maps has been checked on these two paths.
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Link: https://lore.kernel.org/r/20230724023735.2751602-1-shaozhengchao@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This work refactors and adds a lightweight extension ("tcx") to the tc BPF
ingress and egress data path side for allowing BPF program management based
on fds via bpf() syscall through the newly added generic multi-prog API.
The main goal behind this work which we also presented at LPC [0] last year
and a recent update at LSF/MM/BPF this year [3] is to support long-awaited
BPF link functionality for tc BPF programs, which allows for a model of safe
ownership and program detachment.
Given the rise in tc BPF users in cloud native environments, this becomes
necessary to avoid hard to debug incidents either through stale leftover
programs or 3rd party applications accidentally stepping on each others toes.
As a recap, a BPF link represents the attachment of a BPF program to a BPF
hook point. The BPF link holds a single reference to keep BPF program alive.
Moreover, hook points do not reference a BPF link, only the application's
fd or pinning does. A BPF link holds meta-data specific to attachment and
implements operations for link creation, (atomic) BPF program update,
detachment and introspection. The motivation for BPF links for tc BPF programs
is multi-fold, for example:
- From Meta: "It's especially important for applications that are deployed
fleet-wide and that don't "control" hosts they are deployed to. If such
application crashes and no one notices and does anything about that, BPF
program will keep running draining resources or even just, say, dropping
packets. We at FB had outages due to such permanent BPF attachment
semantics. With fd-based BPF link we are getting a framework, which allows
safe, auto-detachable behavior by default, unless application explicitly
opts in by pinning the BPF link." [1]
- From Cilium-side the tc BPF programs we attach to host-facing veth devices
and phys devices build the core datapath for Kubernetes Pods, and they
implement forwarding, load-balancing, policy, EDT-management, etc, within
BPF. Currently there is no concept of 'safe' ownership, e.g. we've recently
experienced hard-to-debug issues in a user's staging environment where
another Kubernetes application using tc BPF attached to the same prio/handle
of cls_bpf, accidentally wiping all Cilium-based BPF programs from underneath
it. The goal is to establish a clear/safe ownership model via links which
cannot accidentally be overridden. [0,2]
BPF links for tc can co-exist with non-link attachments, and the semantics are
in line also with XDP links: BPF links cannot replace other BPF links, BPF
links cannot replace non-BPF links, non-BPF links cannot replace BPF links and
lastly only non-BPF links can replace non-BPF links. In case of Cilium, this
would solve mentioned issue of safe ownership model as 3rd party applications
would not be able to accidentally wipe Cilium programs, even if they are not
BPF link aware.
Earlier attempts [4] have tried to integrate BPF links into core tc machinery
to solve cls_bpf, which has been intrusive to the generic tc kernel API with
extensions only specific to cls_bpf and suboptimal/complex since cls_bpf could
be wiped from the qdisc also. Locking a tc BPF program in place this way, is
getting into layering hacks given the two object models are vastly different.
We instead implemented the tcx (tc 'express') layer which is an fd-based tc BPF
attach API, so that the BPF link implementation blends in naturally similar to
other link types which are fd-based and without the need for changing core tc
internal APIs. BPF programs for tc can then be successively migrated from classic
cls_bpf to the new tc BPF link without needing to change the program's source
code, just the BPF loader mechanics for attaching is sufficient.
For the current tc framework, there is no change in behavior with this change
and neither does this change touch on tc core kernel APIs. The gist of this
patch is that the ingress and egress hook have a lightweight, qdisc-less
extension for BPF to attach its tc BPF programs, in other words, a minimal
entry point for tc BPF. The name tcx has been suggested from discussion of
earlier revisions of this work as a good fit, and to more easily differ between
the classic cls_bpf attachment and the fd-based one.
For the ingress and egress tcx points, the device holds a cache-friendly array
with program pointers which is separated from control plane (slow-path) data.
Earlier versions of this work used priority to determine ordering and expression
of dependencies similar as with classic tc, but it was challenged that for
something more future-proof a better user experience is required. Hence this
resulted in the design and development of the generic attach/detach/query API
for multi-progs. See prior patch with its discussion on the API design. tcx is
the first user and later we plan to integrate also others, for example, one
candidate is multi-prog support for XDP which would benefit and have the same
'look and feel' from API perspective.
The goal with tcx is to have maximum compatibility to existing tc BPF programs,
so they don't need to be rewritten specifically. Compatibility to call into
classic tcf_classify() is also provided in order to allow successive migration
or both to cleanly co-exist where needed given its all one logical tc layer and
the tcx plus classic tc cls/act build one logical overall processing pipeline.
tcx supports the simplified return codes TCX_NEXT which is non-terminating (go
to next program) and terminating ones with TCX_PASS, TCX_DROP, TCX_REDIRECT.
The fd-based API is behind a static key, so that when unused the code is also
not entered. The struct tcx_entry's program array is currently static, but
could be made dynamic if necessary at a point in future. The a/b pair swap
design has been chosen so that for detachment there are no allocations which
otherwise could fail.
The work has been tested with tc-testing selftest suite which all passes, as
well as the tc BPF tests from the BPF CI, and also with Cilium's L4LB.
Thanks also to Nikolay Aleksandrov and Martin Lau for in-depth early reviews
of this work.
[0] https://lpc.events/event/16/contributions/1353/
[1] https://lore.kernel.org/bpf/CAEf4BzbokCJN33Nw_kg82sO=xppXnKWEncGTWCTB9vGCmLB6pw@mail.gmail.com
[2] https://colocatedeventseu2023.sched.com/event/1Jo6O/tales-from-an-ebpf-programs-murder-mystery-hemanth-malla-guillaume-fournier-datadog
[3] http://vger.kernel.org/bpfconf2023_material/tcx_meta_netdev_borkmann.pdf
[4] https://lore.kernel.org/bpf/20210604063116.234316-1-memxor@gmail.com
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20230719140858.13224-3-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Introduce new netlink attribute NETDEV_A_DEV_XDP_ZC_MAX_SEGS that will
carry maximum fragments that underlying ZC driver is able to handle on
TX side. It is going to be included in netlink response only when driver
supports ZC. Any value higher than 1 implies multi-buffer ZC support on
underlying device.
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230719132421.584801-11-maciej.fijalkowski@intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
We have for some time the assign_bit() API to replace open coded
if (foo)
set_bit(n, bar);
else
clear_bit(n, bar);
Use this API in the code. No functional change intended.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Message-ID: <20230710100830.89936-1-andriy.shevchenko@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Commit ad72c4a06a introduced optimization to return from function
quickly if the MAC address is not changing at all. It was reported
that such change causes dev->addr_assign_type to not change
to NET_ADDR_SET from _PERM or _RANDOM.
Restore the old behavior and skip only call to ndo_set_mac_address.
Fixes: ad72c4a06a ("net: add check for current MAC address in dev_set_mac_address")
Reported-by: Gal Pressman <gal@nvidia.com>
Signed-off-by: Piotr Gardocki <piotrx.gardocki@intel.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20230621132106.991342-1-piotrx.gardocki@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In some cases it is possible for kernel to come with request
to change primary MAC address to the address that is already
set on the given interface.
Add proper check to return fast from the function in these cases.
An example of such case is adding an interface to bonding
channel in balance-alb mode:
modprobe bonding mode=balance-alb miimon=100 max_bonds=1
ip link set bond0 up
ifenslave bond0 <eth>
Signed-off-by: Piotr Gardocki <piotrx.gardocki@intel.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
New users of dev_get_by_index() and dev_get_by_name() keep
getting added and it would be nice to steer them towards
the APIs with reference tracking.
Add variants of those calls which allocate the reference
tracker and use them in a couple of places.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move declarations into include/net/gso.h and code into net/core/gso.c
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230608191738.3947077-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Cross-merge networking fixes after downstream PR.
Conflicts:
net/sched/sch_taprio.c
d636fc5dd6 ("net: sched: add rcu annotations around qdisc->qdisc_sleeping")
dced11ef84 ("net/sched: taprio: don't overwrite "sch" variable in taprio_dump_class_stats()")
net/ipv4/sysctl_net_ipv4.c
e209fee411 ("net/ipv4: ping_group_range: allow GID from 2147483648 to 4294967294")
ccce324dab ("tcp: make the first N SYN RTO backoffs linear")
https://lore.kernel.org/all/20230605100816.08d41a7b@canb.auug.org.au/
No adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add READ_ONCE()/WRITE_ONCE() on accesses to the sock flow table.
This also prevents a (smart ?) compiler to remove the condition in:
if (table->ents[index] != newval)
table->ents[index] = newval;
We need the condition to avoid dirtying a shared cache line.
Fixes: fec5e652e5 ("rfs: Receive Flow Steering")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Andrzej Hajda says:
====================
drm/i915: use ref_tracker library for tracking wakerefs
This is reviewed series of ref_tracker patches, ready to merge
via network tree, rebased on net-next/main.
i915 patches will be merged later via intel-gfx tree.
====================
Merge on top of an -rc tag in case it's needed in another tree.
Link: https://lore.kernel.org/r/20230224-track_gt-v9-0-5b47a33f55d1@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In case the library is tracking busy subsystem, simply
printing stack for every active reference will spam log
with long, hard to read, redundant stack traces. To improve
readabilty following changes have been made:
- reports are printed per stack_handle - log is more compact,
- added display name for ref_tracker_dir - it will differentiate
multiple subsystems,
- stack trace is printed indented, in the same printk call,
- info about dropped references is printed as well.
Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
If PREEMPT_RT is set, then assume that the user focuses on minimum
latency. Therefore don't set sw irq coalescing defaults.
This affects the defaults only, users can override these settings
via sysfs.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/f9439c7f-c92c-4c2c-703e-110f96d841b7@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Busy polling is currently not allowed on PREEMPT_RT, because it disables
preemption while invoking the NAPI callback. It is not possible to acquire
sleeping locks with disabled preemption. For details see commit
20ab39d13e ("net/core: disable NET_RX_BUSY_POLL on PREEMPT_RT").
However, strict cyclic and/or low latency network applications may prefer busy
polling e.g., using AF_XDP instead of interrupt driven communication.
The preempt_disable() is used in order to prevent the poll_owner and NAPI owner
to be preempted while owning the resource to ensure progress. Netpoll performs
busy polling in order to acquire the lock. NAPI is locked by setting the
NAPIF_STATE_SCHED flag. There is no busy polling if the flag is set and the
"owner" is preempted. Worst case is that the task owning NAPI gets preempted and
NAPI processing stalls. This is can be prevented by properly prioritising the
tasks within the system.
Allow RX_BUSY_POLL on PREEMPT_RT if NETPOLL is disabled. Don't disable
preemption on PREEMPT_RT within the busy poll loop.
Tested on x86 hardware with v6.1-RT and v6.3-RT on Intel i225 (igc) with
AF_XDP/ZC sockets configured to run in busy polling mode.
Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
We use napi_threaded_poll() in order to reduce our softirq dependency.
We can add a followup of 821eba962d ("net: optimize napi_schedule_rps()")
to further remove the need of firing NET_RX_SOFTIRQ whenever
RPS/RFS are used.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If we call skb_defer_free_flush() from napi_threaded_poll(),
we can avoid to raise IPI from skb_attempt_defer_free()
when the list becomes too big.
This allows napi_threaded_poll() to rely less on softirqs,
and lowers latency caused by a too big list.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We plan using skb_defer_free_flush() from napi_threaded_poll()
in the following patch.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
kfree_skb() can be called from hard irq handlers,
but skb_attempt_defer_free() is meant to be used
from process or BH contexts, and skb_defer_free_flush()
is meant to be called from BH contexts.
Not having to mask hard irq can save some cycles.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
__kfree_skb_defer() uses the old naming where "defer" meant
slab bulk free/alloc APIs. In the meantime we also made
__kfree_skb_defer() feed the per-NAPI skb cache, which
implies bulk APIs. So take away the 'defer' and add 'napi'.
While at it add a drop reason. This only matters on the
tx_action path, if the skb has a frag_list. But getting
rid of a SKB_DROP_REASON_NOT_SPECIFIED seems like a net
benefit so why not.
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://lore.kernel.org/r/20230420020005.815854-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
SCTP is not universally deployed, allow hiding its bit
from the skb.
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Recent patches to mlx5 mentioned a regression when moving from
driver local page pool to only using the generic page pool code.
Page pool has two recycling paths (1) direct one, which runs in
safe NAPI context (basically consumer context, so producing
can be lockless); and (2) via a ptr_ring, which takes a spin
lock because the freeing can happen from any CPU; producer
and consumer may run concurrently.
Since the page pool code was added, Eric introduced a revised version
of deferred skb freeing. TCP skbs are now usually returned to the CPU
which allocated them, and freed in softirq context. This places the
freeing (producing of pages back to the pool) enticingly close to
the allocation (consumer).
If we can prove that we're freeing in the same softirq context in which
the consumer NAPI will run - lockless use of the cache is perfectly fine,
no need for the lock.
Let drivers link the page pool to a NAPI instance. If the NAPI instance
is scheduled on the same CPU on which we're freeing - place the pages
in the direct cache.
With that and patched bnxt (XDP enabled to engage the page pool, sigh,
bnxt really needs page pool work :() I see a 2.6% perf boost with
a TCP stream test (app on a different physical core than softirq).
The CPU use of relevant functions decreases as expected:
page_pool_refill_alloc_cache 1.17% -> 0%
_raw_spin_lock 2.41% -> 0.98%
Only consider lockless path to be safe when NAPI is scheduled
- in practice this should cover majority if not all of steady state
workloads. It's usually the NAPI kicking in that causes the skb flush.
The main case we'll miss out on is when application runs on the same
CPU as NAPI. In that case we don't use the deferred skb free path.
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Tested-by: Dragos Tatulea <dtatulea@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The commits referenced below allows userspace to use the NLM_F_ECHO flag
for RTM_NEW/DELLINK operations to receive unicast notifications for the
affected link. Prior to these changes, applications may have relied on
multicast notifications to learn the same information without specifying
the NLM_F_ECHO flag.
For such applications, the mentioned commits changed the behavior for
requests not using NLM_F_ECHO. Multicast notifications are still received,
but now use the portid of the requester and the sequence number of the
request instead of zero values used previously. For the application, this
message may be unexpected and likely handled as a response to the
NLM_F_ACKed request, especially if it uses the same socket to handle
requests and notifications.
To fix existing applications relying on the old notification behavior,
set the portid and sequence number in the notification only if the
request included the NLM_F_ECHO flag. This restores the old behavior
for applications not using it, but allows unicasted notifications for
others.
Fixes: f3a63cce1b ("rtnetlink: Honour NLM_F_ECHO flag in rtnl_delete_link")
Fixes: d88e136cab ("rtnetlink: Honour NLM_F_ECHO flag in rtnl_newlink_create")
Signed-off-by: Martin Willi <martin@strongswan.org>
Acked-by: Guillaume Nault <gnault@redhat.com>
Acked-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20230411074319.24133-1-martin@strongswan.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
There was a sort of rush surrounding commit 88c0a6b503 ("net: create a
netdev notifier for DSA to reject PTP on DSA master"), due to a desire
to convert DSA's attempt to deny TX timestamping on a DSA master to
something that doesn't block the kernel-wide API conversion from
ndo_eth_ioctl() to ndo_hwtstamp_set().
What was required was a mechanism that did not depend on ndo_eth_ioctl(),
and what was provided was a mechanism that did not depend on
ndo_eth_ioctl(), while at the same time introducing something that
wasn't absolutely necessary - a new netdev notifier.
There have been objections from Jakub Kicinski that using notifiers in
general when they are not absolutely necessary creates complications to
the control flow and difficulties to maintainers who look at the code.
So there is a desire to not use notifiers.
In addition to that, the notifier chain gets called even if there is no
DSA in the system and no one is interested in applying any restriction.
Take the model of udp_tunnel_nic_ops and introduce a stub mechanism,
through which net/core/dev_ioctl.c can call into DSA even when
CONFIG_NET_DSA=m.
Compared to the code that existed prior to the notifier conversion, aka
what was added in commits:
- 4cfab35667 ("net: dsa: Add wrappers for overloaded ndo_ops")
- 3369afba1e ("net: Call into DSA netdevice_ops wrappers")
this is different because we are not overloading any struct
net_device_ops of the DSA master anymore, but rather, we are exposing a
rather specific functionality which is orthogonal to which API is used
to enable it - ndo_eth_ioctl() or ndo_hwtstamp_set().
Also, what is similar is that both approaches use function pointers to
get from built-in code to DSA.
There is no point in replicating the function pointers towards
__dsa_master_hwtstamp_validate() once for every CPU port (dev->dsa_ptr).
Instead, it is sufficient to introduce a singleton struct dsa_stubs,
built into the kernel, which contains a single function pointer to
__dsa_master_hwtstamp_validate().
I find this approach preferable to what we had originally, because
dev->dsa_ptr->netdev_ops->ndo_do_ioctl() used to require going through
struct dsa_port (dev->dsa_ptr), and so, this was incompatible with any
attempts to add any data encapsulation and hide DSA data structures from
the outside world.
Link: https://lore.kernel.org/netdev/20230403083019.120b72fd@kernel.org/
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
assume the following setup on a single machine:
1. An openvswitch instance with one bridge and default flows
2. two network namespaces "server" and "client"
3. two ovs interfaces "server" and "client" on the bridge
4. for each ovs interface a veth pair with a matching name and 32 rx and
tx queues
5. move the ends of the veth pairs to the respective network namespaces
6. assign ip addresses to each of the veth ends in the namespaces (needs
to be the same subnet)
7. start some http server on the server network namespace
8. test if a client in the client namespace can reach the http server
when following the actions below the host has a chance of getting a cpu
stuck in a infinite loop:
1. send a large amount of parallel requests to the http server (around
3000 curls should work)
2. in parallel delete the network namespace (do not delete interfaces or
stop the server, just kill the namespace)
there is a low chance that this will cause the below kernel cpu stuck
message. If this does not happen just retry.
Below there is also the output of bpftrace for the functions mentioned
in the output.
The series of events happening here is:
1. the network namespace is deleted calling
`unregister_netdevice_many_notify` somewhere in the process
2. this sets first `NETREG_UNREGISTERING` on both ends of the veth and
then runs `synchronize_net`
3. it then calls `call_netdevice_notifiers` with `NETDEV_UNREGISTER`
4. this is then handled by `dp_device_event` which calls
`ovs_netdev_detach_dev` (if a vport is found, which is the case for
the veth interface attached to ovs)
5. this removes the rx_handlers of the device but does not prevent
packages to be sent to the device
6. `dp_device_event` then queues the vport deletion to work in
background as a ovs_lock is needed that we do not hold in the
unregistration path
7. `unregister_netdevice_many_notify` continues to call
`netdev_unregister_kobject` which sets `real_num_tx_queues` to 0
8. port deletion continues (but details are not relevant for this issue)
9. at some future point the background task deletes the vport
If after 7. but before 9. a packet is send to the ovs vport (which is
not deleted at this point in time) which forwards it to the
`dev_queue_xmit` flow even though the device is unregistering.
In `skb_tx_hash` (which is called in the `dev_queue_xmit`) path there is
a while loop (if the packet has a rx_queue recorded) that is infinite if
`dev->real_num_tx_queues` is zero.
To prevent this from happening we update `do_output` to handle devices
without carrier the same as if the device is not found (which would
be the code path after 9. is done).
Additionally we now produce a warning in `skb_tx_hash` if we will hit
the infinite loop.
bpftrace (first word is function name):
__dev_queue_xmit server: real_num_tx_queues: 1, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 1
netdev_core_pick_tx server: addr: 0xffff9f0a46d4a000 real_num_tx_queues: 1, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 1
dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 2, reg_state: 1
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 6, reg_state: 2
ovs_netdev_detach_dev server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, reg_state: 2
netdev_rx_handler_unregister server: real_num_tx_queues: 1, cpu: 9, pid: 21024, tid: 21024, reg_state: 2
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
netdev_rx_handler_unregister ret server: real_num_tx_queues: 1, cpu: 9, pid: 21024, tid: 21024, reg_state: 2
dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 27, reg_state: 2
dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 22, reg_state: 2
dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 18, reg_state: 2
netdev_unregister_kobject: real_num_tx_queues: 1, cpu: 9, pid: 21024, tid: 21024
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
ovs_vport_send server: real_num_tx_queues: 0, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 2
__dev_queue_xmit server: real_num_tx_queues: 0, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 2
netdev_core_pick_tx server: addr: 0xffff9f0a46d4a000 real_num_tx_queues: 0, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 2
broken device server: real_num_tx_queues: 0, cpu: 2, pid: 28024, tid: 28024
ovs_dp_detach_port server: real_num_tx_queues: 0 cpu 9, pid: 9124, tid: 9124, reg_state: 2
synchronize_rcu_expedited: cpu 9, pid: 33604, tid: 33604
stuck message:
watchdog: BUG: soft lockup - CPU#5 stuck for 26s! [curl:1929279]
Modules linked in: veth pktgen bridge stp llc ip_set_hash_net nft_counter xt_set nft_compat nf_tables ip_set_hash_ip ip_set nfnetlink_cttimeout nfnetlink openvswitch nsh nf_conncount nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 tls binfmt_misc nls_iso8859_1 input_leds joydev serio_raw dm_multipath scsi_dh_rdac scsi_dh_emc scsi_dh_alua sch_fq_codel drm efi_pstore virtio_rng ip_tables x_tables autofs4 btrfs blake2b_generic zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear hid_generic usbhid hid crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel virtio_net ahci net_failover crypto_simd cryptd psmouse libahci virtio_blk failover
CPU: 5 PID: 1929279 Comm: curl Not tainted 5.15.0-67-generic #74-Ubuntu
Hardware name: OpenStack Foundation OpenStack Nova, BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:netdev_pick_tx+0xf1/0x320
Code: 00 00 8d 48 ff 0f b7 c1 66 39 ca 0f 86 e9 01 00 00 45 0f b7 ff 41 39 c7 0f 87 5b 01 00 00 44 29 f8 41 39 c7 0f 87 4f 01 00 00 <eb> f2 0f 1f 44 00 00 49 8b 94 24 28 04 00 00 48 85 d2 0f 84 53 01
RSP: 0018:ffffb78b40298820 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff9c8773adc2e0 RCX: 000000000000083f
RDX: 0000000000000000 RSI: ffff9c8773adc2e0 RDI: ffff9c870a25e000
RBP: ffffb78b40298858 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff9c870a25e000
R13: ffff9c870a25e000 R14: ffff9c87fe043480 R15: 0000000000000000
FS: 00007f7b80008f00(0000) GS:ffff9c8e5f740000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7b80f6a0b0 CR3: 0000000329d66000 CR4: 0000000000350ee0
Call Trace:
<IRQ>
netdev_core_pick_tx+0xa4/0xb0
__dev_queue_xmit+0xf8/0x510
? __bpf_prog_exit+0x1e/0x30
dev_queue_xmit+0x10/0x20
ovs_vport_send+0xad/0x170 [openvswitch]
do_output+0x59/0x180 [openvswitch]
do_execute_actions+0xa80/0xaa0 [openvswitch]
? kfree+0x1/0x250
? kfree+0x1/0x250
? kprobe_perf_func+0x4f/0x2b0
? flow_lookup.constprop.0+0x5c/0x110 [openvswitch]
ovs_execute_actions+0x4c/0x120 [openvswitch]
ovs_dp_process_packet+0xa1/0x200 [openvswitch]
? ovs_ct_update_key.isra.0+0xa8/0x120 [openvswitch]
? ovs_ct_fill_key+0x1d/0x30 [openvswitch]
? ovs_flow_key_extract+0x2db/0x350 [openvswitch]
ovs_vport_receive+0x77/0xd0 [openvswitch]
? __htab_map_lookup_elem+0x4e/0x60
? bpf_prog_680e8aff8547aec1_kfree+0x3b/0x714
? trace_call_bpf+0xc8/0x150
? kfree+0x1/0x250
? kfree+0x1/0x250
? kprobe_perf_func+0x4f/0x2b0
? kprobe_perf_func+0x4f/0x2b0
? __mod_memcg_lruvec_state+0x63/0xe0
netdev_port_receive+0xc4/0x180 [openvswitch]
? netdev_port_receive+0x180/0x180 [openvswitch]
netdev_frame_hook+0x1f/0x40 [openvswitch]
__netif_receive_skb_core.constprop.0+0x23d/0xf00
__netif_receive_skb_one_core+0x3f/0xa0
__netif_receive_skb+0x15/0x60
process_backlog+0x9e/0x170
__napi_poll+0x33/0x180
net_rx_action+0x126/0x280
? ttwu_do_activate+0x72/0xf0
__do_softirq+0xd9/0x2e7
? rcu_report_exp_cpu_mult+0x1b0/0x1b0
do_softirq+0x7d/0xb0
</IRQ>
<TASK>
__local_bh_enable_ip+0x54/0x60
ip_finish_output2+0x191/0x460
__ip_finish_output+0xb7/0x180
ip_finish_output+0x2e/0xc0
ip_output+0x78/0x100
? __ip_finish_output+0x180/0x180
ip_local_out+0x5e/0x70
__ip_queue_xmit+0x184/0x440
? tcp_syn_options+0x1f9/0x300
ip_queue_xmit+0x15/0x20
__tcp_transmit_skb+0x910/0x9c0
? __mod_memcg_state+0x44/0xa0
tcp_connect+0x437/0x4e0
? ktime_get_with_offset+0x60/0xf0
tcp_v4_connect+0x436/0x530
__inet_stream_connect+0xd4/0x3a0
? kprobe_perf_func+0x4f/0x2b0
? aa_sk_perm+0x43/0x1c0
inet_stream_connect+0x3b/0x60
__sys_connect_file+0x63/0x70
__sys_connect+0xa6/0xd0
? setfl+0x108/0x170
? do_fcntl+0xe8/0x5a0
__x64_sys_connect+0x18/0x20
do_syscall_64+0x5c/0xc0
? __x64_sys_fcntl+0xa9/0xd0
? exit_to_user_mode_prepare+0x37/0xb0
? syscall_exit_to_user_mode+0x27/0x50
? do_syscall_64+0x69/0xc0
? __sys_setsockopt+0xea/0x1e0
? exit_to_user_mode_prepare+0x37/0xb0
? syscall_exit_to_user_mode+0x27/0x50
? __x64_sys_setsockopt+0x1f/0x30
? do_syscall_64+0x69/0xc0
? irqentry_exit+0x1d/0x30
? exc_page_fault+0x89/0x170
entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f7b8101c6a7
Code: 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2a 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 18 89 54 24 0c 48 89 34 24 89
RSP: 002b:00007ffffd6b2198 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7b8101c6a7
RDX: 0000000000000010 RSI: 00007ffffd6b2360 RDI: 0000000000000005
RBP: 0000561f1370d560 R08: 00002795ad21d1ac R09: 0030312e302e302e
R10: 00007ffffd73f080 R11: 0000000000000246 R12: 0000561f1370c410
R13: 0000000000000000 R14: 0000000000000005 R15: 0000000000000000
</TASK>
Fixes: 7f8a436eaa ("openvswitch: Add conntrack action")
Co-developed-by: Luca Czesla <luca.czesla@mail.schwarz>
Signed-off-by: Luca Czesla <luca.czesla@mail.schwarz>
Signed-off-by: Felix Huettner <felix.huettner@mail.schwarz>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/ZC0pBXBAgh7c76CA@kernel-bug-kernel-bug
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The fact that PTP 2-step TX timestamping is broken on DSA switches if
the master also timestamps the same packets is documented by commit
f685e609a3 ("net: dsa: Deny PTP on master if switch supports it").
We attempt to help the users avoid shooting themselves in the foot by
making DSA reject the timestamping ioctls on an interface that is a DSA
master, and the switch tree beneath it contains switches which are aware
of PTP.
The only problem is that there isn't an established way of intercepting
ndo_eth_ioctl calls, so DSA creates avoidable burden upon the network
stack by creating a struct dsa_netdevice_ops with overlaid function
pointers that are manually checked from the relevant call sites. There
used to be 2 such dsa_netdevice_ops, but now, ndo_eth_ioctl is the only
one left.
There is an ongoing effort to migrate driver-visible hardware timestamping
control from the ndo_eth_ioctl() based API to a new ndo_hwtstamp_set()
model, but DSA actively prevents that migration, since dsa_master_ioctl()
is currently coded to manually call the master's legacy ndo_eth_ioctl(),
and so, whenever a network device driver would be converted to the new
API, DSA's restrictions would be circumvented, because any device could
be used as a DSA master.
The established way for unrelated modules to react on a net device event
is via netdevice notifiers. So we create a new notifier which gets
called whenever there is an attempt to change hardware timestamping
settings on a device.
Finally, there is another reason why a netdev notifier will be a good
idea, besides strictly DSA, and this has to do with PHY timestamping.
With ndo_eth_ioctl(), all MAC drivers must manually call
phy_has_hwtstamp() before deciding whether to act upon SIOCSHWTSTAMP,
otherwise they must pass this ioctl to the PHY driver via
phy_mii_ioctl().
With the new ndo_hwtstamp_set() API, it will be desirable to simply not
make any calls into the MAC device driver when timestamping should be
performed at the PHY level.
But there exist drivers, such as the lan966x switch, which need to
install packet traps for PTP regardless of whether they are the layer
that provides the hardware timestamps, or the PHY is. That would be
impossible to support with the new API.
The proposal there, too, is to introduce a netdev notifier which acts as
a better cue for switching drivers to add or remove PTP packet traps,
than ndo_hwtstamp_set(). The one introduced here "almost" works there as
well, except for the fact that packet traps should only be installed if
the PHY driver succeeded to enable hardware timestamping, whereas here,
we need to deny hardware timestamping on the DSA master before it
actually gets enabled. This is why this notifier is called "PRE_", and
the notifier that would get used for PHY timestamping and packet traps
would be called NETDEV_CHANGE_HWTSTAMP. This isn't a new concept, for
example NETDEV_CHANGEUPPER and NETDEV_PRECHANGEUPPER do the same thing.
In expectation of future netlink UAPI, we also pass a non-NULL extack
pointer to the netdev notifier, and we make DSA populate it with an
informative reason for the rejection. To avoid making it go to waste, we
make the ioctl-based dev_set_hwtstamp() create a fake extack and print
the message to the kernel log.
Link: https://lore.kernel.org/netdev/20230401191215.tvveoi3lkawgg6g4@skbuf/
Link: https://lore.kernel.org/netdev/20230310164451.ls7bbs6pdzs4m6pw@skbuf/
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
____napi_schedule() adds a napi into current cpu softnet_data poll_list,
then raises NET_RX_SOFTIRQ to make sure net_rx_action() will process it.
Idea of this patch is to not raise NET_RX_SOFTIRQ when being called indirectly
from net_rx_action(), because we can process poll_list from this point,
without going to full softirq loop.
This needs a change in net_rx_action() to make sure we restart
its main loop if sd->poll_list was updated without NET_RX_SOFTIRQ
being raised.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Tested-by: Jason Xing <kerneljasonxing@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Based on initial patch from Jason Xing.
Idea is to not raise NET_RX_SOFTIRQ from napi_schedule_rps()
when we queued a packet into another cpu backlog.
We can do this only in the context of us being called indirectly
from net_rx_action(), to have the guarantee our rps_ipi_list
will be processed before we exit from net_rx_action().
Link: https://lore.kernel.org/lkml/20230325152417.5403-1-kerneljasonxing@gmail.com/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Tested-by: Jason Xing <kerneljasonxing@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Yan Zhai