[src/trunk]: src/sys/dev/usb Fix error handling, to prevent kernel crashes wh...

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

details:   https://anonhg.NetBSD.org/src/rev/529b3789781e
branches:  trunk
changeset: 454343:529b3789781e
user:      maxv <maxv%NetBSD.org@localhost>
date:      Sat Sep 14 12:40:31 2019 +0000

description:
Fix error handling, to prevent kernel crashes when detaching an urtw0
device. Also, fail safely if we didn't recognize the RF chip, to prevent
kernel crashes at attach time. Note that other panics are there, maybe
they also should be removed.

Found with vHCI.

diffstat:

 sys/dev/usb/if_urtw.c    |  19 ++++++++++++-------
 sys/dev/usb/if_urtwreg.h |   5 +++++
 2 files changed, 17 insertions(+), 7 deletions(-)

diffs (91 lines):

diff -r 6bb30ac969ef -r 529b3789781e sys/dev/usb/if_urtw.c
--- a/sys/dev/usb/if_urtw.c     Sat Sep 14 12:38:40 2019 +0000
+++ b/sys/dev/usb/if_urtw.c     Sat Sep 14 12:40:31 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_urtw.c,v 1.18 2018/09/12 21:57:18 christos Exp $    */
+/*     $NetBSD: if_urtw.c,v 1.19 2019/09/14 12:40:31 maxv Exp $        */
 /*     $OpenBSD: if_urtw.c,v 1.39 2011/07/03 15:47:17 matthew Exp $    */
 
 /*-
@@ -19,7 +19,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_urtw.c,v 1.18 2018/09/12 21:57:18 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_urtw.c,v 1.19 2019/09/14 12:40:31 maxv Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_usb.h"
@@ -614,6 +614,7 @@
        sc->sc_dev = self;
        sc->sc_udev = uaa->uaa_device;
        sc->sc_hwrev = urtw_lookup(uaa->uaa_vendor, uaa->uaa_product)->rev;
+       sc->sc_init_state = URTW_INIT_NONE;
 
        aprint_naive("\n");
        aprint_normal(": ");
@@ -757,6 +758,8 @@
 
        ieee80211_announce(ic);
 
+       sc->sc_init_state = URTW_INIT_INITED;
+
        return;
 fail:
        aprint_error(": %s failed!\n", __func__);
@@ -774,6 +777,9 @@
 
        sc->sc_dying = true;
 
+       if (sc->sc_init_state < URTW_INIT_INITED)
+               goto out;
+
        callout_halt(&sc->scan_to, NULL);
        callout_halt(&sc->sc_led_ch, NULL);
        callout_destroy(&sc->scan_to);
@@ -794,8 +800,8 @@
        urtw_free_rx_data_list(sc);
        urtw_close_pipes(sc);
 
+out:
        splx(s);
-
        return 0;
 }
 
@@ -1279,8 +1285,7 @@
        if (sc->sc_hwrev & URTW_HWREV_8187) {
                error = urtw_eprom_read32(sc, URTW_EPROM_RFCHIPID, &data);
                if (error != 0)
-                       panic("unsupported RF chip");
-                       /* NOTREACHED */
+                       return error;
                switch (data & 0xff) {
                case URTW_EPROM_RFCHIPID_RTL8225U:
                        error = urtw_8225_isv2(sc, &ret);
@@ -1313,8 +1318,8 @@
        return 0;
 
 fail:
-       panic("unsupported RF chip %d", data & 0xff);
-       /* NOTREACHED */
+       aprint_error(": unsupported RF chip %d", data & 0xff);
+       return USBD_INVAL;
 }
 
 usbd_status
diff -r 6bb30ac969ef -r 529b3789781e sys/dev/usb/if_urtwreg.h
--- a/sys/dev/usb/if_urtwreg.h  Sat Sep 14 12:38:40 2019 +0000
+++ b/sys/dev/usb/if_urtwreg.h  Sat Sep 14 12:40:31 2019 +0000
@@ -323,6 +323,11 @@
        struct ieee80211com             sc_ic;
        struct ethercom                 sc_ec;
 #define sc_if  sc_ec.ec_if
+
+       enum {
+               URTW_INIT_NONE,
+               URTW_INIT_INITED
+       } sc_init_state;
        int                             (*sc_newstate)(struct ieee80211com *,
                                            enum ieee80211_state, int);
        struct urtw_rf                  sc_rf;