From owner-freebsd-net  Wed Mar 28  0: 2:37 2001
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Date: Wed, 28 Mar 2001 12:02:10 +0400
From: Yar Tikhiy <yar@comp.chem.msu.su>
To: Archie Cobbs <archie@dellroad.org>
Cc: freebsd-stable@FreeBSD.ORG, freebsd-net@FreeBSD.ORG
Subject: Re: Kernel Panic on 4.3-RC #0 using PPPoE
Message-ID: <20010328120209.A35959@comp.chem.msu.su>
References: <4.2.2.20010327070955.01db1268@192.168.0.12> <200103272040.f2RKeBn44013@arch20m.dellroad.org> <20010328113049.B28919@comp.chem.msu.su>
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In-Reply-To: <20010328113049.B28919@comp.chem.msu.su>; from yar@comp.chem.msu.su on Wed, Mar 28, 2001 at 11:30:49AM +0400
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On Wed, Mar 28, 2001 at 11:30:49AM +0400, Yar Tikhiy wrote:
> 
> Please take a careful look at the frames 6 through 9 of the stack
> trace in PR#25478, so you may notice that your patch happens to do
> nothing about the broblem.  You are going to add a check for IFF_UP
> to ether_output_frame() while that function is just a bottom half
> of ether_output(), which does do the check at its very beginning.
 
Just a clarifying note: Please keep in mind that ether_output()
(frame 9) through vlan_start() (frame 7) are called on a vlan interface
while fxp_start() (frame 6) is called on a different interface - fxp.

> The real problem is that ethernet card drivers rely on ether_output()
> making sure they are up before calling their if_output()s. AFAIK
> the vlan driver is the only piece of code where the standard
> ether_output()->if_output() order is bypassed, and an if_output()
> routine of an ethernet card is called directly. Therefore, the
> IFF_UP check should be in the vlan code, and I'm going to commit
> a corresponding fix (PR: kern/22179). Any objections?

Please substitute "if_output" with "if_start" when reading
the above paragraph. Sorry :-)

SY, Yar

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