only read the if_bpf pointer once.

diff --git a/sys/net/if_tpmr.c b/sys/net/if_tpmr.c
index 50ac1ed..f6eb99f 100644 (file)
--- a/sys/net/if_tpmr.c
+++ b/sys/net/if_tpmr.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: if_tpmr.c,v 1.29 2021/06/02 01:36:10 dlg Exp $ */
+/*     $OpenBSD: if_tpmr.c,v 1.30 2021/06/02 01:37:10 dlg Exp $ */
 
 /*
  * Copyright (c) 2019 The University of Queensland
@@ -368,7 +368,7 @@ tpmr_input(struct ifnet *ifp0, struct mbuf *m, uint64_t dst, void *brport)
        counters_pkt(ifp->if_counters, ifc_ipackets, ifc_ibytes, len);
 
 #if NBPFILTER > 0
-       if_bpf = ifp->if_bpf;
+       if_bpf = READ_ONCE(ifp->if_bpf);
        if (if_bpf) {
                if (bpf_mtap(if_bpf, m, 0))
                        goto drop;