From owner-freebsd-net@FreeBSD.ORG Mon Apr 22 18:48:49 2013 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id 50405507; Mon, 22 Apr 2013 18:48:49 +0000 (UTC) (envelope-from jmojica@gmail.com) Received: from mail-wi0-x230.google.com (mail-wi0-x230.google.com [IPv6:2a00:1450:400c:c05::230]) by mx1.freebsd.org (Postfix) with ESMTP id B8C751DEB; Mon, 22 Apr 2013 18:48:48 +0000 (UTC) Received: by mail-wi0-f176.google.com with SMTP id hj19so4987612wib.3 for ; Mon, 22 Apr 2013 11:48:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:x-received:in-reply-to:references:date:message-id :subject:from:to:cc:content-type; bh=Tt+pwKm68o1oasOqlSFkSVJzE1mitstJjg9rhp0HEus=; b=zq1ppOk74wZ7RDUC+OKz+3nEa28kD9YPMA2mG7IrjqhqykwAU+9rmWXqS9PVeneYLB mFte0S7xlLfTMVfrLYpurm0p61TBepaGD4KxyF+rAgNu8dh/Vz4Yzey3fOYJqBiM+Hgu xfnwxtOCJRYxJzjnLOI3rPIioDJrL5ynVhz+MK0hxZrLhIR1QWzQJP4UO6/6CyzqI54A 4JsxkA4jJ2V/xuFWLBV41Uc+QMuY2o5f2REgg5q8bV/68YG19I33nw5ohnc/Exue0HcC jvVh7zFv1AI/LmHm1oPvnpyi44c8+fnoQKedA45gZfkTI0r3fni+DZypLsZoO4gw3xb9 h8kg== MIME-Version: 1.0 X-Received: by 10.194.81.71 with SMTP id y7mr55150760wjx.19.1366656527810; Mon, 22 Apr 2013 11:48:47 -0700 (PDT) Received: by 10.194.122.73 with HTTP; Mon, 22 Apr 2013 11:48:47 -0700 (PDT) In-Reply-To: <20130422095759.GC76816@FreeBSD.org> References: <20130422095759.GC76816@FreeBSD.org> Date: Mon, 22 Apr 2013 14:48:47 -0400 Message-ID: Subject: Re: ARP: Error Message in if_ether.c "arprequest: cannot find matching address" From: Juan Mojica To: Gleb Smirnoff Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.14 Cc: FreeBSD Net X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 22 Apr 2013 18:48:49 -0000 Thanks Gleb. I do not believe this path can triggered by an incoming frame. I am planning on adding a KASSERT here to get a core when we exercise this code in our debug images. -Juan On Mon, Apr 22, 2013 at 5:57 AM, Gleb Smirnoff wrote: > On Wed, Apr 17, 2013 at 08:46:42AM -0400, Juan Mojica wrote: > J> We manage to hit the following message with some regularity. > J> > J> arprequest: cannot find matching address > J> > J> The code shows a printf: > J> > J> printf("%s: cannot find matching address\n", __func__); > J> > J> > J> Any reason this is a printf and not a > J> > J> log(LOG_ERR, > J> > J> The only things I can come up with are: > J> > J> a) it is a really severe and should be printed out, which if that is the > J> case why isn't there an assert there? > J> b) whoops, that should probably be a log(LOG_ERR, > J> On our end we need to figure out exactly why we're intermittently > hitting > J> this patch of code. > > Can you please try this patch? Let's see what's going on. > > printf()ing in kernel is especially unsafe when the event can be triggered > remotely. The arprequest() is called on output path of a packet, however > I'm not sure that it can't be triggered by incoming packet. > > -- > Totus tuus, Glebius. > -- Juan Mojica Email: jmojica@gmail.com