Convert allocation of bpf_if in bpfattach2 from M_NOWAIT to M_WAITOK

and remove possible panic condition.

It is already allowed to sleep in bpfattach[2], since BPF_LOCK was
converted to SX lock in r332388. Also move KASSERT() to the top of
function and make full initialization before bpf_if will be linked
to BPF's list of interfaces.

MFC after:	2 weeks

1 files changed, 5 insertions, 7 deletions

diff --git a/sys/net/bpf.c b/sys/net/bpf.c
index 32785f19668d..699679369c2d 100644
--- a/sys/net/bpf.c
+++ b/sys/net/bpf.c
@@ -2592,16 +2592,16 @@ bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
 {
 	struct bpf_if *bp;
 
-	bp = malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO);
-	if (bp == NULL)
-		panic("bpfattach");
+	KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized"));
+
+	bp = malloc(sizeof(*bp), M_BPF, M_WAITOK | M_ZERO);
 
+	rw_init(&bp->bif_lock, "bpf interface lock");
 	LIST_INIT(&bp->bif_dlist);
 	LIST_INIT(&bp->bif_wlist);
 	bp->bif_ifp = ifp;
 	bp->bif_dlt = dlt;
-	rw_init(&bp->bif_lock, "bpf interface lock");
-	KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized"));
+	bp->bif_hdrlen = hdrlen;
 	bp->bif_bpf = driverp;
 	*driverp = bp;
 
@@ -2609,8 +2609,6 @@ bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
 	LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next);
 	BPF_UNLOCK();
 
-	bp->bif_hdrlen = hdrlen;
-
 	if (bootverbose && IS_DEFAULT_VNET(curvnet))
 		if_printf(ifp, "bpf attached\n");
 }