lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 23 Jul 2014 11:22:20 -0700 From: Florian Fainelli <f.fainelli@...il.com> To: Ezequiel Garcia <ezequiel.garcia@...e-electrons.com> Cc: netdev <netdev@...r.kernel.org>, David Miller <davem@...emloft.net>, Thomas Petazzoni <thomas.petazzoni@...e-electrons.com>, Gregory Clement <gregory.clement@...e-electrons.com> Subject: Re: [PATCH 2/2] net: phy: Ensure the MDIO bus module is held 2014-07-22 17:16 GMT-07:00 Ezequiel Garcia <ezequiel.garcia@...e-electrons.com>: > This commit adds proper module_{get,put} to prevent the MDIO bus module > from being unloaded while the phydev is connected. By doing so, we fix > a kernel panic produced when a MDIO driver is removed, but the phydev > that relies on it is attached and running. > > Signed-off-by: Ezequiel Garcia <ezequiel.garcia@...e-electrons.com> > --- > drivers/net/phy/phy_device.c | 23 ++++++++++++++++++++--- > 1 file changed, 20 insertions(+), 3 deletions(-) > > diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c > index 35d753d..a10dc47 100644 > --- a/drivers/net/phy/phy_device.c > +++ b/drivers/net/phy/phy_device.c > @@ -575,6 +575,7 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev, > u32 flags, phy_interface_t interface) > { > struct device *d = &phydev->dev; > + struct module *bus_module; > int err; > > /* Assume that if there is no driver, that it doesn't > @@ -599,6 +600,14 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev, > return -EBUSY; > } > > + /* Increment the bus module reference count */ > + bus_module = phydev->bus->dev.driver ? > + phydev->bus->dev.driver->owner : NULL; > + if (!try_module_get(bus_module)) { > + dev_err(&dev->dev, "failed to get the bus module\n"); > + return -EIO; > + } > + > phydev->attached_dev = dev; > dev->phydev = phydev; > > @@ -614,10 +623,14 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev, > */ > err = phy_init_hw(phydev); > if (err) > - phy_detach(phydev); > - else > - phy_resume(phydev); > + goto err_module_put; > > + phy_resume(phydev); > + return err; > + > +err_module_put: > + module_put(bus_module); > + phy_detach(phydev); Since we are calling phy_detach() which is also attempting to do a module_put(), does not that result in one too many calls to module_put() on error path? > return err; > } > EXPORT_SYMBOL(phy_attach_direct); > @@ -664,6 +677,10 @@ EXPORT_SYMBOL(phy_attach); > void phy_detach(struct phy_device *phydev) > { > int i; > + > + if (phydev->bus->dev.driver) > + module_put(phydev->bus->dev.driver->owner); > + > phydev->attached_dev->phydev = NULL; > phydev->attached_dev = NULL; > phy_suspend(phydev); > -- > 2.0.1 > -- Florian -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists