Date: Thu, 12 Feb 2015 12:00:12 -0800 From: Jack Vogel <jfvogel@gmail.com> To: Sreekanth Rupavatharam <rupavath@juniper.net> Cc: "jfv@freebsd.org" <jfv@freebsd.org>, "freebsd-net@freebsd.org" <freebsd-net@freebsd.org>, hiren panchasara <hiren@strugglingcoder.info> Subject: Re: Double cleanup in igb_attach Message-ID: <CAFOYbc=ed3vrp00aQXQsTPGzerysmYk%2BYEBDzi5TG9ZtxHZJbg@mail.gmail.com> In-Reply-To: <D102367E.1B663%rupavath@juniper.net> References: <D0EC151C.1A7B1%rupavath@juniper.net> <20150127192814.GA63990@strugglingcoder.info> <D0ED2984.1A86C%rupavath@juniper.net> <CAFOYbcmBks6s448stkVjGsWxxNZdZEwX2zxtdUh5cDnmtKEA1w@mail.gmail.com> <26266AD2-4743-4A7B-A87D-F68E2E2425A0@juniper.net> <CAFOYbckAP6t0jkhtswi%2BRnFGtJtN7=feCw6_vneS%2BSEZn4o2Pg@mail.gmail.com> <BABD0D32-30E3-4521-8838-976FF77AE244@juniper.net> <CAFOYbcmPF70yf%2B7BmTdDrrfUtyPP7pkCx8_%2BQdZcfOSA_dAK1w@mail.gmail.com> <D102367E.1B663%rupavath@juniper.net>
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I do not recall if I put that call in myself and, yes, it seems odd. It was probably trying to clean up some bad state a failed attach left things in. If it is removed it should be thoroughly regression tested. Jack On Thu, Feb 12, 2015 at 10:56 AM, Sreekanth Rupavatharam < rupavath@juniper.net> wrote: > Hi Jack, > Actually, looking at the code again, it seems to me that igb_detach is not > supposed to be called from igb_attach at all. It causes more problems than > previously mentioned. E.g., in case of branching to err_late *before* > igb_setup_interface(where the ifp is initialized), calling igb_detach there > causes a NULL pointer access. The best way to deal with it is to take out > the igb_detach call from the err_late: label. Thoughts? Comments? > -- Thanks, > > Sreekanth > > > > From: Jack Vogel <jfvogel@gmail.com> > Date: Tuesday, January 27, 2015 at 12:42 PM > To: Sreekanth Rupavatharam <rupavath@juniper.net> > Cc: hiren panchasara <hiren@strugglingcoder.info>, " > freebsd-net@freebsd.org" <freebsd-net@freebsd.org>, "jfv@freebsd.org" < > jfv@freebsd.org> > Subject: Re: Double cleanup in igb_attach > > Yes, I will look them over. > > Jack > > > On Tue, Jan 27, 2015 at 12:38 PM, Sreekanth Rupavatharam < > rupavath@juniper.net> wrote: > >> Thanks jack, >> Now, can you please review these changes? And commit if you deem it >> fit? >> >> Thanks, >> >> -Sreekanth >> >> On Jan 27, 2015, at 12:24 PM, "Jack Vogel" <jfvogel@gmail.com> wrote: >> >> Errrr, I am one of those people :) (jack.vogel@intel.com) >> >> Jack >> >> >> On Tue, Jan 27, 2015 at 12:21 PM, Sreekanth Rupavatharam < >> rupavath@juniper.net> wrote: >> >>> Definitely, but I didn't have the contact info of those people. >>> >>> Thanks, >>> >>> -Sreekanth >>> >>> On Jan 27, 2015, at 12:15 PM, "Jack Vogel" <jfvogel@gmail.com> wrote: >>> >>> If you want something committed to an Intel driver, asking Intel >>> might be the >>> courteous thing to do, don't you think? >>> >>> Jack >>> >>> >>> On Tue, Jan 27, 2015 at 11:51 AM, Sreekanth Rupavatharam < >>> rupavath@juniper.net> wrote: >>> >>>> Hiren, >>>> Can you help commit this? >>>> >>>> Index: if_igb.c >>>> >>>> =================================================================== >>>> >>>> --- if_igb.c(revision 298053) >>>> >>>> +++ if_igb.c(working copy) >>>> >>>> @@ -723,7 +723,8 @@ igb_attach(device_t dev) >>>> >>>> return (0); >>>> >>>> >>>> >>>> err_late: >>>> >>>> -igb_detach(dev); >>>> >>>> +if(igb_detach(dev) == 0) /* igb_detach did the cleanup */ >>>> >>>> +return(error); >>>> >>>> igb_free_transmit_structures(adapter); >>>> >>>> igb_free_receive_structures(adapter); >>>> >>>> igb_release_hw_control(adapter); >>>> >>>> -- Thanks, >>>> >>>> Sreekanth >>>> >>>> >>>> >>>> >>>> >>>> >>>> On 1/27/15, 11:28 AM, "hiren panchasara" <hiren@strugglingcoder.info> >>>> wrote: >>>> >>>> + Jack >>>> On Tue, Jan 27, 2015 at 12:00:19AM +0000, Sreekanth Rupavatharam wrote: >>>> >>>> Apologies if this is not the right forum. In igb_attach function, we >>>> have this code. >>>> err_late: >>>> igb_detach(dev); >>>> igb_free_transmit_structures(adapter); >>>> igb_free_receive_structures(adapter); >>>> igb_release_hw_control(adapter); >>>> err_pci: >>>> igb_free_pci_resources(adapter); >>>> if (adapter->ifp != NULL) >>>> if_free(adapter->ifp); >>>> free(adapter->mta, M_DEVBUF); >>>> IGB_CORE_LOCK_DESTROY(adapter); >>>> The problem is that igb_detach also does the same cleanup in it?s >>>> body. Only exception is this case where it just returns EBUSY >>>> /* Make sure VLANS are not using driver */ >>>> if (if_vlantrunkinuse(ifp)) { >>>> device_printf(dev,"Vlan in use, detach first\n"); >>>> return (EBUSY); >>>> } >>>> I think the code in igb_attach should be changed to free up resources >>>> only if the igb_detach returns an error. Here?s the patch for it. >>>> Index: if_igb.c >>>> =================================================================== >>>> --- if_igb.c (revision 298025) >>>> +++ if_igb.c (working copy) >>>> @@ -723,7 +723,8 @@ igb_attach(device_t dev) >>>> return (0); >>>> err_late: >>>> - igb_detach(dev); >>>> + if(igb_detach(dev) == 0) /* igb_detach did the cleanup */ >>>> + return; >>>> igb_free_transmit_structures(adapter); >>>> Can anyone comment on it and tell me if my understanding is >>>> incorrect? >>>> >>>> >>>> Seems reasonable to me at the first glance. >>>> >>>> We need to call IGB_CORE_LOCK_DESTROY(adapter) before returning >>>> though. >>>> >>>> cheers, >>>> Hiren >>>> >>>> >>> >> >
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