[src/trunk]: src/sys/dev/pci wm(4): Audit sc->phy.acquire and sc->nvm.acquire.

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

details:   https://anonhg.NetBSD.org/src/rev/8e7afd651719
branches:  trunk
changeset: 368899:8e7afd651719
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Fri Aug 12 10:58:45 2022 +0000

description:
wm(4): Audit sc->phy.acquire and sc->nvm.acquire.

The return value must be used, because some of the acquire/release
pairs hold a mutex from acquire to release, and failing to call
release, or calling release twice, leads to an inconsistent state.

diffstat:

 sys/dev/pci/if_wm.c |  36 ++++++++++++++++++++++++------------
 1 files changed, 24 insertions(+), 12 deletions(-)

diffs (112 lines):

diff -r f131b6ec9358 -r 8e7afd651719 sys/dev/pci/if_wm.c
--- a/sys/dev/pci/if_wm.c       Fri Aug 12 10:58:21 2022 +0000
+++ b/sys/dev/pci/if_wm.c       Fri Aug 12 10:58:45 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_wm.c,v 1.761 2022/08/12 10:58:21 riastradh Exp $    */
+/*     $NetBSD: if_wm.c,v 1.762 2022/08/12 10:58:45 riastradh Exp $    */
 
 /*
  * Copyright (c) 2001, 2002, 2003, 2004 Wasabi Systems, Inc.
@@ -82,7 +82,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.761 2022/08/12 10:58:21 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.762 2022/08/12 10:58:45 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_net_mpsafe.h"
@@ -495,7 +495,7 @@
 };
 
 struct wm_phyop {
-       int (*acquire)(struct wm_softc *);
+       int (*acquire)(struct wm_softc *) __attribute__((warn_unused_result));
        void (*release)(struct wm_softc *);
        int (*readreg_locked)(device_t, int, int, uint16_t *);
        int (*writereg_locked)(device_t, int, int, uint16_t);
@@ -504,7 +504,7 @@
 };
 
 struct wm_nvmop {
-       int (*acquire)(struct wm_softc *);
+       int (*acquire)(struct wm_softc *) __attribute__((warn_unused_result));
        void (*release)(struct wm_softc *);
        int (*read)(struct wm_softc *, int, int, uint16_t *);
 };
@@ -5266,13 +5266,19 @@
 wm_reset_phy(struct wm_softc *sc)
 {
        uint32_t reg;
+       int rv;
 
        DPRINTF(sc, WM_DEBUG_INIT, ("%s: %s called\n",
                device_xname(sc->sc_dev), __func__));
        if (wm_phy_resetisblocked(sc))
                return -1;
 
-       sc->phy.acquire(sc);
+       rv = sc->phy.acquire(sc);
+       if (rv) {
+               device_printf(sc->sc_dev, "%s: failed to acquire phy: %d\n",
+                   __func__, rv);
+               return rv;
+       }
 
        reg = CSR_READ(sc, WMREG_CTRL);
        CSR_WRITE(sc, WMREG_CTRL, reg | CTRL_PHY_RESET);
@@ -5582,7 +5588,8 @@
                break;
        case WM_T_80003:
                reg = CSR_READ(sc, WMREG_CTRL) | CTRL_RST;
-               sc->phy.acquire(sc);
+               if (sc->phy.acquire(sc) != 0)
+                       break;
                CSR_WRITE(sc, WMREG_CTRL, reg);
                sc->phy.release(sc);
                break;
@@ -5609,7 +5616,8 @@
                        phy_reset = 1;
                } else
                        device_printf(sc->sc_dev, "XXX reset is blocked!!!\n");
-               sc->phy.acquire(sc);
+               if (sc->phy.acquire(sc) != 0)
+                       break;
                CSR_WRITE(sc, WMREG_CTRL, reg);
                /* Don't insert a completion barrier when reset */
                delay(20*1000);
@@ -11698,7 +11706,7 @@
        struct wm_softc *sc = device_private(dev);
        int rv;
 
-       rv = sc->phy.acquire(sc); 
+       rv = sc->phy.acquire(sc);
        if (rv != 0) {
                device_printf(dev, "%s: failed to get semaphore\n", __func__);
                return rv;
@@ -11867,7 +11875,7 @@
        if (phy != 1) /* Only one PHY on kumeran bus */
                return -1;
 
-       rv = sc->phy.acquire(sc); 
+       rv = sc->phy.acquire(sc);
        if (rv != 0) {
                device_printf(dev, "%s: failed to get semaphore\n", __func__);
                return rv;
@@ -17021,9 +17029,13 @@
        uint16_t phyreg;
 
        if (link && (speed == STATUS_SPEED_1000)) {
-               sc->phy.acquire(sc);
-               int rv = wm_kmrn_readreg_locked(sc,
-                   KUMCTRLSTA_OFFSET_K1_CONFIG, &phyreg);
+               int rv;
+
+               rv = sc->phy.acquire(sc);
+               if (rv != 0)
+                       return rv;
+               rv = wm_kmrn_readreg_locked(sc, KUMCTRLSTA_OFFSET_K1_CONFIG,
+                   &phyreg);
                if (rv != 0)
                        goto release;
                rv = wm_kmrn_writereg_locked(sc, KUMCTRLSTA_OFFSET_K1_CONFIG,