TencentOS-kernel/net/core
Dongdong Wang 1fc81227a5 lwt: Disable BH too in run_lwt_bpf()
[ Upstream commit d9054a1ff585ba01029584ab730efc794603d68f ]

The per-cpu bpf_redirect_info is shared among all skb_do_redirect()
and BPF redirect helpers. Callers on RX path are all in BH context,
disabling preemption is not sufficient to prevent BH interruption.

In production, we observed strange packet drops because of the race
condition between LWT xmit and TC ingress, and we verified this issue
is fixed after we disable BH.

Although this bug was technically introduced from the beginning, that
is commit 3a0af8fd61f9 ("bpf: BPF for lightweight tunnel infrastructure"),
at that time call_rcu() had to be call_rcu_bh() to match the RCU context.
So this patch may not work well before RCU flavor consolidation has been
completed around v5.0.

Update the comments above the code too, as call_rcu() is now BH friendly.

Signed-off-by: Dongdong Wang <wangdongdong.6@bytedance.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Link: https://lore.kernel.org/bpf/20201205075946.497763-1-xiyou.wangcong@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-16 16:43:20 +08:00
..
Makefile Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
bpf_sk_storage.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
datagram.c net: use indirect call wrappers for skb_copy_datagram_iter() 2021-03-16 16:27:16 +08:00
datagram.h Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
dev.c net: Fix bridge enslavement failure 2021-03-16 16:36:26 +08:00
dev_addr_lists.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
dev_ioctl.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
devlink.c devlink: Hold rtnl lock while reading netdev attributes 2021-03-16 16:41:51 +08:00
drop_monitor.c drop_monitor: work around gcc-10 stringop-overflow warning 2021-03-16 16:27:46 +08:00
dst.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
dst_cache.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
ethtool.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
failover.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
fib_notifier.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
fib_rules.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
filter.c net: Properly typecast int values to set sk_max_pacing_rate 2021-03-16 16:38:17 +08:00
flow_dissector.c flow_dissector: Drop BPF flow dissector prog ref on netns cleanup 2021-03-16 16:28:20 +08:00
flow_offload.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
gen_estimator.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
gen_stats.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
gro_cells.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
hwbm.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
link_watch.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
lwt_bpf.c lwt: Disable BH too in run_lwt_bpf() 2021-03-16 16:43:20 +08:00
lwtunnel.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
neighbour.c Exempt multicast addresses from five-second neighbor lifetime 2021-03-16 16:41:04 +08:00
net-procfs.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
net-sysfs.c net-sysfs: add a newline when printing 'tx_timeout' by sysfs 2021-03-16 16:32:41 +08:00
net-sysfs.h Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
net-traces.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
net_namespace.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
netclassid_cgroup.c cgroup, netclassid: remove double cond_resched 2021-03-16 16:27:30 +08:00
netevent.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
netpoll.c net: Have netpoll bring-up DSA management interface 2021-03-16 16:41:06 +08:00
netprio_cgroup.c netprio_cgroup: Fix unlimited memory leak of v2 cgroups 2021-03-16 16:27:49 +08:00
page_pool.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
pktgen.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
ptp_classifier.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
request_sock.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
rtnetlink.c rtnetlink: Fix memory(net_device) leak when ->newlink fails 2021-03-16 16:32:42 +08:00
scm.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
secure_seq.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
skbuff.c net: skbuff: ensure LSE is pullable before decrementing the MPLS ttl 2021-03-16 16:41:57 +08:00
skmsg.c bpf, sockmap: Avoid returning unneeded EAGAIN when redirecting to self 2021-03-16 16:41:24 +08:00
sock.c socket: don't clear SOCK_TSTAMP_NEW when SO_TIMESTAMPNS is disabled 2021-03-16 16:39:27 +08:00
sock_diag.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
sock_map.c bpf: sockmap: Require attach_bpf_fd when detaching a program 2021-03-16 16:32:59 +08:00
sock_reuseport.c udp: Copy has_conns in reuseport_grow(). 2021-03-16 16:32:43 +08:00
stream.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
sysctl_net_core.c bpf: Check correct cred for CAP_SYSLOG in bpf_dump_raw_ok() 2021-03-16 16:31:38 +08:00
timestamping.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
tso.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
utils.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
xdp.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00