From mboxrd@z Thu Jan 1 00:00:00 1970 From: sebastian.hesselbarth@gmail.com (Sebastian Hesselbarth) Date: Thu, 13 Mar 2014 10:14:21 +0000 Subject: [PATCH v3] net: phy: fix uninitalized WOL parameters in phy_ethtool_get_wol In-Reply-To: <1394677305.20857.29.camel@deadeye.wl.decadent.org.uk> References: <1394484661-4554-2-git-send-email-sebastian.hesselbarth@gmail.com> <1394578975-12588-1-git-send-email-sebastian.hesselbarth@gmail.com> <1394677305.20857.29.camel@deadeye.wl.decadent.org.uk> Message-ID: <532184FD.4000808@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 03/13/2014 02:21 AM, Ben Hutchings wrote: > On Wed, 2014-03-12 at 00:02 +0100, Sebastian Hesselbarth wrote: >> phy_ethtool_get_wol is a helper to get current WOL settings from >> a phy device. When using this helper on a PHY without .get_wol >> callback, struct ethtool_wolinfo is never set-up correctly and >> may contain misleading information about WOL status. >> >> To fix this, always zero relevant fields of struct ethtool_wolinfo >> regardless of .get_wol callback availability. > > Sorry, I still disagree with this. Which is really fine with me. Thanks for constantly commenting this. > You're trying to make phy_ethtool_get_wol() do two subtly different > things: > - Provide an implementation of ethtool_ops::get_wol, leaving the net > driver only to look up phy_device > - Provide a standalone function for executing ETHTOOL_GWOL on a > phy_device > > You may notice that phy_suspend() already sets wol.cmd = ETHTOOL_GWOL. Yeah, which was added by me because I misinterpreted phy_ethtool_get_wol depending on it. It doesn't because we just "reuse" struct ethtool_wolinfo. > So it seems to me like it's taking responsibility for initialising the > structure like ethtool_get_wol() does. The bug is then that > phy_suspend() doesn't clear the rest of the structure. That is not the > responsibility of phy_ethtool_get_wol(). I agree that public ethtool_get_wol should clear the struct, but I am not so happy to have an in-kernel API depend on the caller to setup the struct. In any way, if there are strong reasons not to clear struct ethtool_wolinfo again in phy_ethtool_get_wol, I can properly clear it in phy_suspend instead. I don't have a strong opinion about it. Sebastian >> Signed-off-by: Sebastian Hesselbarth >> Reviewed-by: Florian Fainelli >> --- >> Changelog: >> v1->v2: >> - clear whole struct ethtool_wolinfo >> - check for non-NULL phy_device >> v2->v3: >> - only clear ->supported and ->wolopts (Suggested by Ben Hutchings) >> >> Cc: David Miller >> Cc: Florian Fainelli >> Cc: Ben Hutchings >> Cc: netdev at vger.kernel.org >> Cc: linux-arm-kernel at lists.infradead.org >> Cc: linux-kernel at vger.kernel.org >> --- >> drivers/net/phy/phy.c | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c >> index 19c9eca0ef26..94234a91a50f 100644 >> --- a/drivers/net/phy/phy.c >> +++ b/drivers/net/phy/phy.c >> @@ -1092,7 +1092,9 @@ EXPORT_SYMBOL(phy_ethtool_set_wol); >> >> void phy_ethtool_get_wol(struct phy_device *phydev, struct ethtool_wolinfo *wol) >> { >> - if (phydev->drv->get_wol) >> + wol->supported = wol->wolopts = 0; >> + >> + if (phydev && phydev->drv->get_wol) >> phydev->drv->get_wol(phydev, wol); >> } >> EXPORT_SYMBOL(phy_ethtool_get_wol); >