Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 2 Aug 2012 16:46:42 +0000 (UTC)
From:      "Bjoern A. Zeeb" <bzeeb-lists@lists.zabbadoz.net>
To:        Gleb Smirnoff <glebius@FreeBSD.org>
Cc:        svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org
Subject:   Re: svn commit: r238990 - in head/sys: net netinet netinet6
Message-ID:  <alpine.BSF.2.00.1208021644320.4474@ai.fobar.qr>
In-Reply-To: <201208021357.q72DvoFJ088426@svn.freebsd.org>
References:  <201208021357.q72DvoFJ088426@svn.freebsd.org>

next in thread | previous in thread | raw e-mail | index | archive | help
On Thu, 2 Aug 2012, Gleb Smirnoff wrote:

> Author: glebius
> Date: Thu Aug  2 13:57:49 2012
> New Revision: 238990
> URL: http://svn.freebsd.org/changeset/base/238990
>
> Log:
>  Fix races between in_lltable_prefix_free(), lla_lookup(),
>  llentry_free() and arptimer():
>
>  o Use callout_init_rw() for lle timeout, this allows us safely
>    disestablish them.
>    - This allows us to simplify the arptimer() and make it
>      race safe.
>  o Consistently use ifp->if_afdata_lock to lock access to
>    linked lists in the lle hashes.
>  o Introduce new lle flag LLE_LINKED, which marks an entry that
>    is attached to the hash.
>    - Use LLE_LINKED to avoid double unlinking via consequent
>      calls to llentry_free().
>    - Mark lle with LLE_DELETED via |= operation istead of =,
>      so that other flags won't be lost.
>  o Make LLE_ADDREF(), LLE_REMREF() and LLE_FREE_LOCKED() more
>    consistent and provide more informative KASSERTs.
>
>  The patch is a collaborative work of all submitters and myself.

Quoting from 2 year old memory you just introduced a possible deadlock
on tbale (or with that networkstack) teardown adding the extra af_data
write locking to the table walk.

-- 
Bjoern A. Zeeb                                 You have to have visions!
          Stop bit received. Insert coin for new address family.



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?alpine.BSF.2.00.1208021644320.4474>