Messages in this thread | | | Subject | Re: [PATCH] netlink: Deal with ESRCH error in nlmsg_notify() | From | Yonghong Song <> | Date | Mon, 19 Jul 2021 07:47:15 -0700 |
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On 7/18/21 10:18 PM, Yajun Deng wrote: > Yonghong Song report: > The bpf selftest tc_bpf failed with latest bpf-next. > The following is the command to run and the result: > $ ./test_progs -n 132 > [ 40.947571] bpf_testmod: loading out-of-tree module taints kernel. > test_tc_bpf:PASS:test_tc_bpf__open_and_load 0 nsec > test_tc_bpf:PASS:bpf_tc_hook_create(BPF_TC_INGRESS) 0 nsec > test_tc_bpf:PASS:bpf_tc_hook_create invalid hook.attach_point 0 nsec > test_tc_bpf_basic:PASS:bpf_obj_get_info_by_fd 0 nsec > test_tc_bpf_basic:PASS:bpf_tc_attach 0 nsec > test_tc_bpf_basic:PASS:handle set 0 nsec > test_tc_bpf_basic:PASS:priority set 0 nsec > test_tc_bpf_basic:PASS:prog_id set 0 nsec > test_tc_bpf_basic:PASS:bpf_tc_attach replace mode 0 nsec > test_tc_bpf_basic:PASS:bpf_tc_query 0 nsec > test_tc_bpf_basic:PASS:handle set 0 nsec > test_tc_bpf_basic:PASS:priority set 0 nsec > test_tc_bpf_basic:PASS:prog_id set 0 nsec > libbpf: Kernel error message: Failed to send filter delete notification > test_tc_bpf_basic:FAIL:bpf_tc_detach unexpected error: -3 (errno 3) > test_tc_bpf:FAIL:test_tc_internal ingress unexpected error: -3 (errno 3) > > The failure seems due to the commit > cfdf0d9ae75b ("rtnetlink: use nlmsg_notify() in rtnetlink_send()") > > Deal with ESRCH error in nlmsg_notify() even the report variable is zero. > > Reported-by: Yonghong Song <yhs@fb.com> > Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Thanks for quick fix. This does fix the bpf selftest issu. But does this change have negative impacts on other nlmsg_notify() callers, below 1-3 items?
0 net/core/rtnetlink.c rtnetlink_send 714 return nlmsg_notify(rtnl, skb, pid, group, echo, GFP_KERNEL);
1 net/core/rtnetlink.c rtnl_notify 734 nlmsg_notify(rtnl, skb, pid, group, report, flags);
2 net/netfilter/nfnetlink.c nfnetlink_send 176 return nlmsg_notify(nfnlnet->nfnl, skb, portid, group, echo, flags);
3 net/netlink/genetlink.c genl_notify 1506 nlmsg_notify(sk, skb, info->snd_portid, group, report, flags);
> --- > net/netlink/af_netlink.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c > index 380f95aacdec..24b7cf447bc5 100644 > --- a/net/netlink/af_netlink.c > +++ b/net/netlink/af_netlink.c > @@ -2545,13 +2545,15 @@ int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, > /* errors reported via destination sk->sk_err, but propagate > * delivery errors if NETLINK_BROADCAST_ERROR flag is set */ > err = nlmsg_multicast(sk, skb, exclude_portid, group, flags); > + if (err == -ESRCH) > + err = 0; > } > > if (report) { > int err2; > > err2 = nlmsg_unicast(sk, skb, portid); > - if (!err || err == -ESRCH) > + if (!err) > err = err2; > } > >
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