Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753878AbaJQTbG (ORCPT ); Fri, 17 Oct 2014 15:31:06 -0400 Received: from mail-pa0-f42.google.com ([209.85.220.42]:40047 "EHLO mail-pa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753663AbaJQTbD (ORCPT ); Fri, 17 Oct 2014 15:31:03 -0400 From: Guenter Roeck To: "David S. Miller" Cc: Florian Fainelli , Alexander Duyck , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Guenter Roeck Subject: [PATCH] dsa: Fix conversion from host device to mii bus Date: Fri, 17 Oct 2014 12:30:58 -0700 Message-Id: <1413574258-21766-1-git-send-email-linux@roeck-us.net> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit b4d2394d01bc ("dsa: Replace mii_bus with a generic host device") replaces mii_bus with a generic host_dev, and introduces dsa_host_dev_to_mii_bus() to support conversion from host_dev to mii_bus. However, in some cases it uses to_mii_bus to perform that conversion. Since host_dev is not the phy bus device but typically a platform device, this fails and results in a crash with the affected drivers. BUG: unable to handle kernel NULL pointer dereference at (null) IP: [] __mutex_lock_slowpath+0x75/0x100 PGD 406783067 PUD 406784067 PMD 0 Oops: 0002 [#1] SMP ... Call Trace: [] ? pick_next_task_fair+0x61b/0x880 [] mutex_lock+0x23/0x37 [] mdiobus_read+0x34/0x60 [] __mv88e6xxx_reg_read+0x8a/0xa0 [] mv88e6xxx_reg_read+0x4c/0xa0 Fixes: b4d2394d01bc ("dsa: Replace mii_bus with a generic host device") Cc: Alexander Duyck Signed-off-by: Guenter Roeck --- drivers/net/dsa/mv88e6060.c | 16 ++++++++++++---- drivers/net/dsa/mv88e6xxx.c | 14 ++++++++++---- 2 files changed, 22 insertions(+), 8 deletions(-) diff --git a/drivers/net/dsa/mv88e6060.c b/drivers/net/dsa/mv88e6060.c index 776e965..05b0ca3 100644 --- a/drivers/net/dsa/mv88e6060.c +++ b/drivers/net/dsa/mv88e6060.c @@ -21,8 +21,12 @@ static int reg_read(struct dsa_switch *ds, int addr, int reg) { - return mdiobus_read(to_mii_bus(ds->master_dev), - ds->pd->sw_addr + addr, reg); + struct mii_bus *bus = dsa_host_dev_to_mii_bus(ds->master_dev); + + if (bus == NULL) + return -EINVAL; + + return mdiobus_read(bus, ds->pd->sw_addr + addr, reg); } #define REG_READ(addr, reg) \ @@ -38,8 +42,12 @@ static int reg_read(struct dsa_switch *ds, int addr, int reg) static int reg_write(struct dsa_switch *ds, int addr, int reg, u16 val) { - return mdiobus_write(to_mii_bus(ds->master_dev), - ds->pd->sw_addr + addr, reg, val); + struct mii_bus *bus = dsa_host_dev_to_mii_bus(ds->master_dev); + + if (bus == NULL) + return -EINVAL; + + return mdiobus_write(bus, ds->pd->sw_addr + addr, reg, val); } #define REG_WRITE(addr, reg, val) \ diff --git a/drivers/net/dsa/mv88e6xxx.c b/drivers/net/dsa/mv88e6xxx.c index d6f6428..a6c90cf 100644 --- a/drivers/net/dsa/mv88e6xxx.c +++ b/drivers/net/dsa/mv88e6xxx.c @@ -75,11 +75,14 @@ int __mv88e6xxx_reg_read(struct mii_bus *bus, int sw_addr, int addr, int reg) int mv88e6xxx_reg_read(struct dsa_switch *ds, int addr, int reg) { struct mv88e6xxx_priv_state *ps = ds_to_priv(ds); + struct mii_bus *bus = dsa_host_dev_to_mii_bus(ds->master_dev); int ret; + if (bus == NULL) + return -EINVAL; + mutex_lock(&ps->smi_mutex); - ret = __mv88e6xxx_reg_read(to_mii_bus(ds->master_dev), - ds->pd->sw_addr, addr, reg); + ret = __mv88e6xxx_reg_read(bus, ds->pd->sw_addr, addr, reg); mutex_unlock(&ps->smi_mutex); return ret; @@ -119,11 +122,14 @@ int __mv88e6xxx_reg_write(struct mii_bus *bus, int sw_addr, int addr, int mv88e6xxx_reg_write(struct dsa_switch *ds, int addr, int reg, u16 val) { struct mv88e6xxx_priv_state *ps = ds_to_priv(ds); + struct mii_bus *bus = dsa_host_dev_to_mii_bus(ds->master_dev); int ret; + if (bus == NULL) + return -EINVAL; + mutex_lock(&ps->smi_mutex); - ret = __mv88e6xxx_reg_write(to_mii_bus(ds->master_dev), - ds->pd->sw_addr, addr, reg, val); + ret = __mv88e6xxx_reg_write(bus, ds->pd->sw_addr, addr, reg, val); mutex_unlock(&ps->smi_mutex); return ret; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/