The branch stable/13 has been updated by markj:
URL:
https://cgit.FreeBSD.org/src/commit/?id=c3bd32f225ec093ba0f7cd7fc1a000b02aad5211
commit c3bd32f225ec093ba0f7cd7fc1a000b02aad5211
Author: Mark Johnston <ma...@freebsd.org>
AuthorDate: 2023-03-06 14:39:17 +0000
Commit: Mark Johnston <ma...@freebsd.org>
CommitDate: 2023-03-13 15:53:16 +0000
epair: Avoid loading m_flags into a short
The m_flags field of struct mbuf is 24 bits wide and so gets truncated
in a couple of places in the epair code. Instead of preserving the
entire flag set, just remember whether M_BCAST or M_MCAST is set.
MFC after: 1 week
Sponsored by: Klara, Inc.
(cherry picked from commit 48227d1c6db8fceaceebbf8578612302d64ca170)
---
sys/net/if_epair.c | 95 +++++++++++++++++++++++++++++++-----------------------
1 file changed, 54 insertions(+), 41 deletions(-)
diff --git a/sys/net/if_epair.c b/sys/net/if_epair.c
index e7257f5fa551..05667633fa42 100644
--- a/sys/net/if_epair.c
+++ b/sys/net/if_epair.c
@@ -188,39 +188,14 @@ epair_tx_start_deferred(void *arg, int pending)
if_rele(sc->ifp);
}
-static int
-epair_menq(struct mbuf *m, struct epair_softc *osc)
+static struct epair_queue *
+epair_select_queue(struct epair_softc *sc, struct mbuf *m)
{
- struct ifnet *ifp, *oifp;
- int len, ret;
- int ridx;
- short mflags;
- struct epair_queue *q = NULL;
uint32_t bucket;
#ifdef RSS
struct ether_header *eh;
-#endif
-
- /*
- * I know this looks weird. We pass the "other sc" as we need that one
- * and can get both ifps from it as well.
- */
- oifp = osc->ifp;
- ifp = osc->oifp;
-
- M_ASSERTPKTHDR(m);
- epair_clear_mbuf(m);
- if_setrcvif(m, oifp);
- M_SETFIB(m, oifp->if_fib);
-
- /* Save values as once the mbuf is queued, it's not ours anymore. */
- len = m->m_pkthdr.len;
- mflags = m->m_flags;
-
- MPASS(m->m_nextpkt == NULL);
- MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0);
+ int ret;
-#ifdef RSS
ret = rss_m2bucket(m, &bucket);
if (ret) {
/* Actually hash the packet. */
@@ -246,7 +221,43 @@ epair_menq(struct mbuf *m, struct epair_softc *osc)
#else
bucket = 0;
#endif
- q = &osc->queues[bucket];
+ return (&sc->queues[bucket]);
+}
+
+static void
+epair_prepare_mbuf(struct mbuf *m, struct ifnet *src_ifp)
+{
+ M_ASSERTPKTHDR(m);
+ epair_clear_mbuf(m);
+ if_setrcvif(m, src_ifp);
+ M_SETFIB(m, src_ifp->if_fib);
+
+ MPASS(m->m_nextpkt == NULL);
+ MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0);
+}
+
+static void
+epair_menq(struct mbuf *m, struct epair_softc *osc)
+{
+ struct ifnet *ifp, *oifp;
+ int len, ret;
+ int ridx;
+ bool mcast;
+
+ /*
+ * I know this looks weird. We pass the "other sc" as we need that one
+ * and can get both ifps from it as well.
+ */
+ oifp = osc->ifp;
+ ifp = osc->oifp;
+
+ epair_prepare_mbuf(m, oifp);
+
+ /* Save values as once the mbuf is queued, it's not ours anymore. */
+ len = m->m_pkthdr.len;
+ mcast = (m->m_flags & (M_BCAST | M_MCAST)) != 0;
+
+ struct epair_queue *q = epair_select_queue(osc, m);
atomic_set_long(&q->state, (1 << BIT_MBUF_QUEUED));
ridx = atomic_load_int(&q->ridx);
@@ -255,7 +266,7 @@ epair_menq(struct mbuf *m, struct epair_softc *osc)
/* Ring is full. */
if_inc_counter(ifp, IFCOUNTER_OQDROPS, 1);
m_freem(m);
- return (0);
+ return;
}
if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
@@ -265,15 +276,13 @@ epair_menq(struct mbuf *m, struct epair_softc *osc)
* the logic another time.
*/
if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
- if (mflags & (M_BCAST|M_MCAST))
+ if (mcast)
if_inc_counter(ifp, IFCOUNTER_OMCASTS, 1);
/* Someone else received the packet. */
if_inc_counter(oifp, IFCOUNTER_IPACKETS, 1);
if (!atomic_testandset_long(&q->state, BIT_QUEUE_TASK))
- taskqueue_enqueue(epair_tasks.tq[bucket], &q->tx_task);
-
- return (0);
+ taskqueue_enqueue(epair_tasks.tq[q->id], &q->tx_task);
}
static void
@@ -317,8 +326,10 @@ epair_transmit(struct ifnet *ifp, struct mbuf *m)
{
struct epair_softc *sc;
struct ifnet *oifp;
- int error, len;
- short mflags;
+#ifdef ALTQ
+ int len;
+ bool mcast;
+#endif
if (m == NULL)
return (0);
@@ -355,10 +366,12 @@ epair_transmit(struct ifnet *ifp, struct mbuf *m)
m_freem(m);
return (0);
}
- len = m->m_pkthdr.len;
- mflags = m->m_flags;
#ifdef ALTQ
+ len = m->m_pkthdr.len;
+ mcast = (m->m_flags & (M_BCAST | M_MCAST)) != 0;
+ int error = 0;
+
/* Support ALTQ via the classic if_start() path. */
IF_LOCK(&ifp->if_snd);
if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
@@ -368,7 +381,7 @@ epair_transmit(struct ifnet *ifp, struct mbuf *m)
IF_UNLOCK(&ifp->if_snd);
if (!error) {
if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
- if (mflags & (M_BCAST|M_MCAST))
+ if (mcast)
if_inc_counter(ifp, IFCOUNTER_OMCASTS, 1);
epair_start(ifp);
}
@@ -377,8 +390,8 @@ epair_transmit(struct ifnet *ifp, struct mbuf *m)
IF_UNLOCK(&ifp->if_snd);
#endif
- error = epair_menq(m, oifp->if_softc);
- return (error);
+ epair_menq(m, oifp->if_softc);
+ return (0);
}
static int
