From 44aa8f0264c19830b9f6fd1de53c456054f85b53 Mon Sep 17 00:00:00 2001
From: "Samuel J. Greear" <sjg@thesjg.com>
Date: Mon, 26 Jul 2010 08:40:52 +0000
Subject: [PATCH] bpf - do wakeup at the proper time

* kq runs the filters to determine readiness after a KNOTE, KNOTE must be
  called after twiddling struct members that will have an impact on the
  readiness check.
---
 sys/net/bpf.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/sys/net/bpf.c b/sys/net/bpf.c
index 461ab49996..6ff0fd9804 100644
--- a/sys/net/bpf.c
+++ b/sys/net/bpf.c
@@ -1303,6 +1303,7 @@ catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
 	struct bpf_hdr *hp;
 	int totlen, curlen;
 	int hdrlen = d->bd_bif->bif_hdrlen;
+	int wakeup = 0;
 	/*
 	 * Figure out how many bytes to move.  If the packet is
 	 * greater or equal to the snapshot length, transfer that
@@ -1332,7 +1333,7 @@ catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
 			return;
 		}
 		ROTATE_BUFFERS(d);
-		bpf_wakeup(d);
+		wakeup = 1;
 		curlen = 0;
 	} else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) {
 		/*
@@ -1340,7 +1341,7 @@ catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
 		 * already expired during a select call.  A packet
 		 * arrived, so the reader should be woken up.
 		 */
-		bpf_wakeup(d);
+		wakeup = 1;
 	}
 
 	/*
@@ -1355,6 +1356,9 @@ catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
 	 */
 	(*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen));
 	d->bd_slen = curlen + totlen;
+
+	if (wakeup)
+		bpf_wakeup(d);
 }
 
 /*
-- 
2.41.0