Message ID | E1jdac8-0005tC-3o@rmk-PC.armlinux.org.uk |
---|---|
State | RFC |
Delegated to: | David Miller |
Headers | show |
Series | Clause 45 PHY probing cleanups | expand |
Hi, On 5/26/20 9:31 AM, Russell King wrote: > Expand the device_ids[] array to allow all MMD IDs to be read rather > than just the first 8 MMDs, but only read the ID if the MDIO_STAT2 > register reports that a device really is present here for these new > devices to maintain compatibility with our current behaviour. > > 88X3310 PHY vendor MMDs do are marked as present in the > devices_in_package, but do not contain IEE 802.3 compatible register > sets in their lower space. This avoids reading incorrect values as MMD > identifiers. > > Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> > --- > drivers/net/phy/phy_device.c | 14 ++++++++++++++ > include/linux/phy.h | 2 +- > 2 files changed, 15 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c > index 1c948bbf4fa0..92742c7be80f 100644 > --- a/drivers/net/phy/phy_device.c > +++ b/drivers/net/phy/phy_device.c > @@ -773,6 +773,20 @@ static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id, > if (!(devs_in_pkg & (1 << i))) > continue; > > + if (i >= 8) { > + /* Only probe the MMD ID for MMDs >= 8 if they report > + * that they are present. We have at least one PHY that > + * reports MMD presence in devs_in_pkg, but does not > + * contain valid IEEE 802.3 ID registers in some MMDs. > + */ > + ret = phy_c45_probe_present(bus, addr, i); > + if (ret < 0) > + return ret; > + > + if (!ret) > + continue; > + } > + > phy_reg = mdiobus_c45_read(bus, addr, i, MII_PHYSID1); > if (phy_reg < 0) > return -EIO; > diff --git a/include/linux/phy.h b/include/linux/phy.h > index 0d41c710339a..3325dd8fb9ac 100644 > --- a/include/linux/phy.h > +++ b/include/linux/phy.h > @@ -361,7 +361,7 @@ enum phy_state { > struct phy_c45_device_ids { > u32 devices_in_package; > u32 mmds_present; > - u32 device_ids[8]; > + u32 device_ids[MDIO_MMD_NUM]; You have a array overflow/invalid access if you don't do this earlier in 4/7. > }; > > struct macsec_context; >
On Tue, May 26, 2020 at 10:35:46AM -0500, Jeremy Linton wrote: > Hi, > > On 5/26/20 9:31 AM, Russell King wrote: > > Expand the device_ids[] array to allow all MMD IDs to be read rather > > than just the first 8 MMDs, but only read the ID if the MDIO_STAT2 > > register reports that a device really is present here for these new > > devices to maintain compatibility with our current behaviour. > > > > 88X3310 PHY vendor MMDs do are marked as present in the > > devices_in_package, but do not contain IEE 802.3 compatible register > > sets in their lower space. This avoids reading incorrect values as MMD > > identifiers. > > > > Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> > > --- > > drivers/net/phy/phy_device.c | 14 ++++++++++++++ > > include/linux/phy.h | 2 +- > > 2 files changed, 15 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c > > index 1c948bbf4fa0..92742c7be80f 100644 > > --- a/drivers/net/phy/phy_device.c > > +++ b/drivers/net/phy/phy_device.c > > @@ -773,6 +773,20 @@ static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id, > > if (!(devs_in_pkg & (1 << i))) > > continue; > > + if (i >= 8) { > > + /* Only probe the MMD ID for MMDs >= 8 if they report > > + * that they are present. We have at least one PHY that > > + * reports MMD presence in devs_in_pkg, but does not > > + * contain valid IEEE 802.3 ID registers in some MMDs. > > + */ > > + ret = phy_c45_probe_present(bus, addr, i); > > + if (ret < 0) > > + return ret; > > + > > + if (!ret) > > + continue; > > + } > > + > > phy_reg = mdiobus_c45_read(bus, addr, i, MII_PHYSID1); > > if (phy_reg < 0) > > return -EIO; > > diff --git a/include/linux/phy.h b/include/linux/phy.h > > index 0d41c710339a..3325dd8fb9ac 100644 > > --- a/include/linux/phy.h > > +++ b/include/linux/phy.h > > @@ -361,7 +361,7 @@ enum phy_state { > > struct phy_c45_device_ids { > > u32 devices_in_package; > > u32 mmds_present; > > - u32 device_ids[8]; > > + u32 device_ids[MDIO_MMD_NUM]; > > You have a array overflow/invalid access if you don't do this earlier in > 4/7. I'm very sorry, but you are mistaken - there is no overflow. The overflow would happen if I'd changed the _second_ loop in get_phy_c45_ids(), but that still relies upon the size of this array. In fact, everywhere that the device_ids array is indexed with a for() loop, the maximum bound is defined by the element size of the array.
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index 1c948bbf4fa0..92742c7be80f 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -773,6 +773,20 @@ static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id, if (!(devs_in_pkg & (1 << i))) continue; + if (i >= 8) { + /* Only probe the MMD ID for MMDs >= 8 if they report + * that they are present. We have at least one PHY that + * reports MMD presence in devs_in_pkg, but does not + * contain valid IEEE 802.3 ID registers in some MMDs. + */ + ret = phy_c45_probe_present(bus, addr, i); + if (ret < 0) + return ret; + + if (!ret) + continue; + } + phy_reg = mdiobus_c45_read(bus, addr, i, MII_PHYSID1); if (phy_reg < 0) return -EIO; diff --git a/include/linux/phy.h b/include/linux/phy.h index 0d41c710339a..3325dd8fb9ac 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -361,7 +361,7 @@ enum phy_state { struct phy_c45_device_ids { u32 devices_in_package; u32 mmds_present; - u32 device_ids[8]; + u32 device_ids[MDIO_MMD_NUM]; }; struct macsec_context;
Expand the device_ids[] array to allow all MMD IDs to be read rather than just the first 8 MMDs, but only read the ID if the MDIO_STAT2 register reports that a device really is present here for these new devices to maintain compatibility with our current behaviour. 88X3310 PHY vendor MMDs do are marked as present in the devices_in_package, but do not contain IEE 802.3 compatible register sets in their lower space. This avoids reading incorrect values as MMD identifiers. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> --- drivers/net/phy/phy_device.c | 14 ++++++++++++++ include/linux/phy.h | 2 +- 2 files changed, 15 insertions(+), 1 deletion(-)