Date: Thu, 12 Feb 2015 21:36:39 +0000 From: Sreekanth Rupavatharam <rupavath@juniper.net> To: Jack Vogel <jfvogel@gmail.com> 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: <D1025BBD.1B686%rupavath@juniper.net> In-Reply-To: <CAFOYbc=ed3vrp00aQXQsTPGzerysmYk%2BYEBDzi5TG9ZtxHZJbg@mail.gmail.com> 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> <CAFOYbc=ed3vrp00aQXQsTPGzerysmYk%2BYEBDzi5TG9ZtxHZJbg@mail.gmail.com>
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Looking at the em driver, the em_detach is missing from the same place.
return (0);
759<http://optimus.englab.juniper.net:8180/source/xref/X-FreeBSD-10/sys/dev=
/e1000/if_em.c#759>
760<http://optimus.englab.juniper.net:8180/source/xref/X-FreeBSD-10/sys/dev=
/e1000/if_em.c#760>err_late<http://optimus.englab.juniper.net:8180/source/s=
?defs=3Derr_late&project=3DX-FreeBSD-10>:
761<http://optimus.englab.juniper.net:8180/source/xref/X-FreeBSD-10/sys/dev=
/e1000/if_em.c#761> em_free_transmit_structures<http://optimus.engla=
b.juniper.net:8180/source/xref/X-FreeBSD-10/sys/dev/e1000/if_em.c#em_free_t=
ransmit_structures>(adapter<http://optimus.englab.juniper.net:8180/source/s=
?defs=3Dadapter&project=3DX-FreeBSD-10>);
762<http://optimus.englab.juniper.net:8180/source/xref/X-FreeBSD-10/sys/dev=
/e1000/if_em.c#762> em_free_receive_structures<http://optimus.englab=
.juniper.net:8180/source/xref/X-FreeBSD-10/sys/dev/e1000/if_em.c#em_free_re=
ceive_structures>(adapter<http://optimus.englab.juniper.net:8180/source/s?d=
efs=3Dadapter&project=3DX-FreeBSD-10>);
763<http://optimus.englab.juniper.net:8180/source/xref/X-FreeBSD-10/sys/dev=
/e1000/if_em.c#763> em_release_hw_control<http://optimus.englab.juni=
per.net:8180/source/xref/X-FreeBSD-10/sys/dev/e1000/if_em.c#em_release_hw_c=
ontrol>(adapter<http://optimus.englab.juniper.net:8180/source/s?defs=3Dadap=
ter&project=3DX-FreeBSD-10>);
764<http://optimus.englab.juniper.net:8180/source/xref/X-FreeBSD-10/sys/dev=
/e1000/if_em.c#764> if (adapter<http://optimus.englab.juniper.net:81=
80/source/s?defs=3Dadapter&project=3DX-FreeBSD-10>->ifp<http://optimus.engl=
ab.juniper.net:8180/source/s?defs=3Difp&project=3DX-FreeBSD-10> !=3D NULL<h=
ttp://optimus.englab.juniper.net:8180/source/s?defs=3DNULL&project=3DX-Free=
BSD-10>)
765<http://optimus.englab.juniper.net:8180/source/xref/X-FreeBSD-10/sys/dev=
/e1000/if_em.c#765> if_free<http://optimus.englab.juniper.ne=
t:8180/source/s?defs=3Dif_free&project=3DX-FreeBSD-10>(adapter<http://optim=
us.englab.juniper.net:8180/source/s?defs=3Dadapter&project=3DX-FreeBSD-10>-=
>ifp<http://optimus.englab.juniper.net:8180/source/s?defs=3Difp&project=3DX=
-FreeBSD-10>);
766<http://optimus.englab.juniper.net:8180/source/xref/X-FreeBSD-10/sys/dev=
/e1000/if_em.c#766>err_pci<http://optimus.englab.juniper.net:8180/source/s?=
defs=3Derr_pci&project=3DX-FreeBSD-10>:
-- Thanks,
Sreekanth
From: Jack Vogel <jfvogel@gmail.com<mailto:jfvogel@gmail.com>>
Date: Thursday, February 12, 2015 at 12:00 PM
To: Sreekanth Rupavatharam <rupavath@juniper.net<mailto:rupavath@juniper.ne=
t>>
Cc: hiren panchasara <hiren@strugglingcoder.info<mailto:hiren@strugglingcod=
er.info>>, "freebsd-net@freebsd.org<mailto:freebsd-net@freebsd.org>" <freeb=
sd-net@freebsd.org<mailto:freebsd-net@freebsd.org>>, "jfv@freebsd.org<mailt=
o:jfv@freebsd.org>" <jfv@freebsd.org<mailto:jfv@freebsd.org>>
Subject: Re: Double cleanup in igb_attach
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<mailto: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 cau=
ses 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<mailto:jfvogel@gmail.com>>
Date: Tuesday, January 27, 2015 at 12:42 PM
To: Sreekanth Rupavatharam <rupavath@juniper.net<mailto:rupavath@juniper.ne=
t>>
Cc: hiren panchasara <hiren@strugglingcoder.info<mailto:hiren@strugglingcod=
er.info>>, "freebsd-net@freebsd.org<mailto:freebsd-net@freebsd.org>" <freeb=
sd-net@freebsd.org<mailto:freebsd-net@freebsd.org>>, "jfv@freebsd.org<mailt=
o:jfv@freebsd.org>" <jfv@freebsd.org<mailto: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<mailto:rupavath@juniper.net>> wrote:
Thanks jack,
Now, can you please review these changes? And commit if you deem it fi=
t?
Thanks,
-Sreekanth
On Jan 27, 2015, at 12:24 PM, "Jack Vogel" <jfvogel@gmail.com<mailto:jfvoge=
l@gmail.com>> wrote:
Errrr, I am one of those people :) (jack.vogel@intel.com<mailto:jack.vogel=
@intel.com>)
Jack
On Tue, Jan 27, 2015 at 12:21 PM, Sreekanth Rupavatharam <rupavath@juniper.=
net<mailto: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<mailto:jfvoge=
l@gmail.com>> wrote:
If you want something committed to an Intel driver, asking Intel might be t=
he
courteous thing to do, don't you think?
Jack
On Tue, Jan 27, 2015 at 11:51 AM, Sreekanth Rupavatharam <rupavath@juniper.=
net<mailto:rupavath@juniper.net>> wrote:
Hiren,
Can you help commit this?
Index: if_igb.c
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
--- 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) =3D=3D 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<mailto=
: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 t=
his 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 !=3D 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. Onl=
y 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
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
--- 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) =3D=3D 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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