kernel - Fix lockmgr lock mismatch panics when iwn used without wlan

* If if_iwn is ifconfig'd without going through wlan the wlan_serializer
  is not held during the firmware load stage, resulting in a panic.
  Acquire the serializer for this case.

* Note: iwn worked fine with wlan, but this fixes an annoying panic when
  people try to mess with it without wlan.

Reported-by: fxr (irc)

diff --git a/sys/dev/netif/iwn/if_iwn.c b/sys/dev/netif/iwn/if_iwn.c
index 877eb1c..4e16478 100644 (file)
--- a/sys/dev/netif/iwn/if_iwn.c
+++ b/sys/dev/netif/iwn/if_iwn.c
@@ -5666,16 +5666,19 @@ iwn_read_firmware(struct iwn_softc *sc)
        const uint32_t *ptr;
        uint32_t rev;
        size_t size;
+       int wlan_serialized;
 
        /*
         * Read firmware image from filesystem.  The firmware can block
         * in a taskq and deadlock against our serializer so unlock
         * while we do tihs.
         */
-       wlan_assert_serialized();
-       wlan_serialize_exit();
+       wlan_serialized = IS_SERIALIZED(&wlan_global_serializer);
+       if (wlan_serialized)
+               wlan_serialize_exit();
        sc->fw_fp = firmware_get(sc->fwname);
-       wlan_serialize_enter();
+       if (wlan_serialized)
+               wlan_serialize_enter();
        if (sc->fw_fp == NULL) {
                device_printf(sc->sc_dev,
                    "%s: could not load firmare image \"%s\"\n", __func__,
@@ -5964,25 +5967,25 @@ iwn_hw_init(struct iwn_softc *sc)
                device_printf(sc->sc_dev,
                    "%s: could not power ON adapter, error %d\n",
                    __func__, error);
-               return error;
+               goto done;
        }
 
        /* Select VMAIN power source. */
        error = iwn_nic_lock(sc);
        if (error != 0)
-               return error;
+               goto done;
        iwn_prph_clrbits(sc, IWN_APMG_PS, IWN_APMG_PS_PWR_SRC_MASK);
        iwn_nic_unlock(sc);
 
        /* Perform adapter-specific initialization. */
        error = hal->nic_config(sc);
        if (error != 0)
-               return error;
+               goto done;
 
        /* Initialize RX ring. */
        error = iwn_nic_lock(sc);
        if (error != 0)
-               return error;
+               goto done;
        IWN_WRITE(sc, IWN_FH_RX_CONFIG, 0);
        IWN_WRITE(sc, IWN_FH_RX_WPTR, 0);
        /* Set physical address of RX ring (256-byte aligned.) */
@@ -6002,7 +6005,7 @@ iwn_hw_init(struct iwn_softc *sc)
 
        error = iwn_nic_lock(sc);
        if (error != 0)
-               return error;
+               goto done;
 
        /* Initialize TX scheduler. */
        iwn_prph_write(sc, hal->sched_txfact_addr, 0);
@@ -6047,7 +6050,7 @@ iwn_hw_init(struct iwn_softc *sc)
                device_printf(sc->sc_dev,
                    "%s: could not load firmware, error %d\n",
                    __func__, error);
-               return error;
+               goto done;
        }
        /* Wait at most one second for firmware alive notification. */
        error = zsleep(sc, &wlan_global_serializer, 0, "iwninit", hz);
@@ -6055,10 +6058,12 @@ iwn_hw_init(struct iwn_softc *sc)
                device_printf(sc->sc_dev,
                    "%s: timeout waiting for adapter to initialize, error %d\n",
                    __func__, error);
-               return error;
+               goto done;
        }
        /* Do post-firmware initialization. */
-       return hal->post_alive(sc);
+       error = hal->post_alive(sc);
+done:
+       return error;
 }
 
 static void
@@ -6120,6 +6125,19 @@ iwn_init_locked(struct iwn_softc *sc)
 {
        struct ifnet *ifp = sc->sc_ifp;
        int error;
+       int wlan_serializer_needed;
+
+       /*
+        * The kernel generic firmware loader can wind up calling this
+        * without the wlan serializer, while the wlan subsystem will
+        * call it with the serializer.
+        *
+        * Make sure we hold the serializer or we will have timing issues
+        * with the wlan subsystem.
+        */
+       wlan_serializer_needed = !IS_SERIALIZED(&wlan_global_serializer);
+       if (wlan_serializer_needed)
+               wlan_serialize_enter();
 
        error = iwn_hw_prepare(sc);
        if (error != 0) {
@@ -6140,6 +6158,8 @@ iwn_init_locked(struct iwn_softc *sc)
                /* Enable interrupts to get RF toggle notifications. */
                IWN_WRITE(sc, IWN_INT, 0xffffffff);
                IWN_WRITE(sc, IWN_INT_MASK, sc->int_mask);
+               if (wlan_serializer_needed)
+                       wlan_serialize_exit();
                return;
        }
 
@@ -6174,11 +6194,14 @@ iwn_init_locked(struct iwn_softc *sc)
 
        ifp->if_flags &= ~IFF_OACTIVE;
        ifp->if_flags |= IFF_RUNNING;
-
+       if (wlan_serializer_needed)
+               wlan_serialize_exit();
        return;
 
 fail:
        iwn_stop_locked(sc);
+       if (wlan_serializer_needed)
+               wlan_serialize_exit();
 }
 
 static void