Messages in this thread | | | Date | Fri, 14 Mar 2014 10:06:58 +0100 | From | Sebastian Hesselbarth <> | Subject | Re: [PATCH v3] net: phy: fix uninitalized WOL parameters in phy_ethtool_get_wol |
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On 03/13/2014 08:38 PM, David Miller wrote: > From: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> > Date: Wed, 12 Mar 2014 00:02:55 +0100 > >> 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. >> >> Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> >> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> > > I'm starting to see this situation more clearly now, especially with > Ben's most recent commentary. > > The basic notion is that one must do ethtool ops are designed such that > the top-level execution context in net/core/ethtool.c takes care of > initializing the structure. > > In this case, we're referring specifically to ethtool_get_wol(), which > runs any time ETHTOOL_GWOL is requested. > > Therefore no ethtool_ops->get_wol() implementation should duplicate > this work, that goes for all of such cases which invoke the function > we are talking about here, phy_ethtool_get_wol(). > > So the first change is definitely to remove: > > wol->supported = 0; > wol->wolopts = 0; > > from: > > drivers/net/ethernet/marvell/mv643xx_eth.c:mv643xx_eth_get_wol() > drivers/net/ethernet/ti/cpsw.c:cpsw_get_wol() > > Next, I think phy_suspend() must create the same environment the > call sites above guarentee for phy_ethtool_get_wol(), namely > by changing the declaration of 'wol' to: > > struct ethtool_wolinfo wol = { .cmd = ETHTOOL_GWOL }; > > which will cause the compiler to clear out the rest of the structure > for us, as the same declaration does in ethtool_get_wol(). > > Finally, purge the spurious clears in phydev_ops->get_wol(), namely > in at803x_get_wol() and m88e1318_get_wol(). > > So, to reiterate, OPS never have to be mindful of initializing the > ethtool result with zeros. However, anyone who calls into OPS > directly must provide said expected state. > > Are we all on the same page now?
Yes, we are. I'll send a fix for phy_suspend in a minute - still based on v3.14-rc1 in case there will be another -rc.
If not, I'll rebase that fix on net-next together with patches for the four offending drivers you named above.
Sebastian
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