Date: Wed, 3 Nov 2004 19:28:06 +0100 From: devet@devet.org (Arjan de Vet) To: peadar.edwards@gmail.com Cc: current@freebsd.org Subject: Re: if_sk patch to get more info from people with problems Message-ID: <20041103182806.GA1040@adv.devet.org> In-Reply-To: <34cb7c8404110209563fc01498@mail.gmail.com> References: <Pine.BSF.4.53.0411011123190.90940@e0-0.zab2.int.zabbadoz.net>
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In article <34cb7c8404110209563fc01498@mail.gmail.com> you write:
>Ok, I don't have this hardware, but dumb question:
>
>A (very) quick look at the source reveals that buffers are allocated
>via sk_rxeof()->sk_newbuf()->sk_jalloc() in the interrupt receive
>function, with the softc lock held in sk_rxeof().
>
>They're freed by the mbuf system via a call to sk_jfree(), but that
>doesn't hold the SK_LOCK. Is this possibly the source of the
>corruption problems? What am I missing?
>This compiles, anyway :-)
>
>--- /tmp/if_sk.c Tue Nov 2 17:49:26 2004
>+++ if_sk.c Tue Nov 2 17:52:20 2004
>@@ -1115,12 +1115,14 @@
> if ((i < 0) || (i >= SK_JSLOTS))
> panic("sk_jfree: asked to free buffer that we don't manage!");
>
>+ SK_LOCK(sc_if->sk_softc);
> entry = SLIST_FIRST(&sc_if->sk_jinuse_listhead);
> if (entry == NULL)
> panic("sk_jfree: buffer not in use!");
> entry->slot = i;
> SLIST_REMOVE_HEAD(&sc_if->sk_jinuse_listhead, jpool_entries);
> SLIST_INSERT_HEAD(&sc_if->sk_jfree_listhead, entry, jpool_entries);
>+ SK_UNLOCK(sc_if->sk_softc);
>
> return;
> }
Thank you very much! This patch seems to fix the network corruption
problems I have reported in kern/73038. I'll do some more testing,
because sometimes the problems only appear after some time. But for now,
I can use if_sk.c without debug.mpsafenet="0" on 5.3-RC2.
Arjan
--
Arjan de Vet, Eindhoven, The Netherlands <devet@devet.org>
URL : http://www.devet.org/ <Arjan.deVet@adv.iae.nl>
Work: http://www.madison-gurkha.com/ (Security, Open Source, Education)
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