[src/trunk]: src/sys/arch/arm/sunxi Eliminate use of IFF_OACTIVE.

[thorpej <thorpej%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/fbcc63b712fe
branches:  trunk
changeset: 370142:fbcc63b712fe
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Sun Sep 18 15:44:29 2022 +0000

description:
Eliminate use of IFF_OACTIVE.

While here, fix a use-after-free bug in the "too many segments" error path in
sunxi_emac_setup_txbuf().

diffstat:

 sys/arch/arm/sunxi/sunxi_emac.c |  27 ++++++++++++++++-----------
 1 files changed, 16 insertions(+), 11 deletions(-)

diffs (87 lines):

diff -r 920fba6a6b48 -r fbcc63b712fe sys/arch/arm/sunxi/sunxi_emac.c
--- a/sys/arch/arm/sunxi/sunxi_emac.c   Sun Sep 18 15:28:01 2022 +0000
+++ b/sys/arch/arm/sunxi/sunxi_emac.c   Sun Sep 18 15:44:29 2022 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: sunxi_emac.c,v 1.36 2022/06/28 05:19:03 skrll Exp $ */
+/* $NetBSD: sunxi_emac.c,v 1.37 2022/09/18 15:44:29 thorpej Exp $ */
 
 /*-
  * Copyright (c) 2016-2017 Jared McNeill <jmcneill%invisible.ca@localhost>
@@ -33,7 +33,7 @@
 #include "opt_net_mpsafe.h"
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sunxi_emac.c,v 1.36 2022/06/28 05:19:03 skrll Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sunxi_emac.c,v 1.37 2022/09/18 15:44:29 thorpej Exp $");
 
 #include <sys/param.h>
 #include <sys/bus.h>
@@ -351,8 +351,8 @@
        if (error == EFBIG) {
                device_printf(sc->dev,
                    "TX packet needs too many DMA segments, dropping...\n");
-               m_freem(m);
-               return 0;
+               /* Caller will dequeue and free packet. */
+               return -1;
        }
        if (error != 0)
                return 0;
@@ -447,12 +447,11 @@
 
        EMAC_ASSERT_LOCKED(sc);
 
-       if ((ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING)
+       if ((ifp->if_flags & IFF_RUNNING) == 0)
                return;
 
        for (cnt = 0, start = sc->tx.cur; ; cnt++) {
                if (sc->tx.queued >= TX_DESC_COUNT - TX_MAX_SEGS) {
-                       ifp->if_flags |= IFF_OACTIVE;
                        break;
                }
 
@@ -461,8 +460,16 @@
                        break;
 
                nsegs = sunxi_emac_setup_txbuf(sc, sc->tx.cur, m);
-               if (nsegs == 0) {
-                       ifp->if_flags |= IFF_OACTIVE;
+               if (__predict_false(nsegs <= 0)) {
+                       if (nsegs == -1) {
+                               /*
+                                * We're being asked to discard this packet,
+                                * but we can try to continue.
+                                */
+                               IFQ_DEQUEUE(&ifp->if_snd, m);
+                               m_freem(m);
+                               continue;
+                       }
                        break;
                }
                IFQ_DEQUEUE(&ifp->if_snd, m);
@@ -702,7 +709,6 @@
        WR4(sc, EMAC_RX_CTL_0, val | RX_EN | CHECK_CRC);
 
        ifp->if_flags |= IFF_RUNNING;
-       ifp->if_flags &= ~IFF_OACTIVE;
 
        mii_mediachg(mii);
        callout_schedule(&sc->stat_ch, hz);
@@ -760,7 +766,7 @@
        val = RD4(sc, EMAC_RX_CTL_1);
        WR4(sc, EMAC_RX_CTL_1, val & ~RX_DMA_EN);
 
-       ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
+       ifp->if_flags &= ~IFF_RUNNING;
 }
 
 static void
@@ -876,7 +882,6 @@
                    i, i + 1, TX_DESC_COUNT,
                    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
 
-               ifp->if_flags &= ~IFF_OACTIVE;
                if_statinc(ifp, if_opackets);
        }