From owner-freebsd-dtrace@FreeBSD.ORG Wed Nov 6 02:45:56 2013 Return-Path: Delivered-To: freebsd-dtrace@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id B30E954A for ; Wed, 6 Nov 2013 02:45:56 +0000 (UTC) (envelope-from markjdb@gmail.com) Received: from mail-ie0-x230.google.com (mail-ie0-x230.google.com [IPv6:2607:f8b0:4001:c03::230]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 7F3942841 for ; Wed, 6 Nov 2013 02:45:56 +0000 (UTC) Received: by mail-ie0-f176.google.com with SMTP id u16so15904089iet.7 for ; Tue, 05 Nov 2013 18:45:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; bh=jkIJmEaHRr2VJ/7CYNmQqthHy4q365Gwi7/kaFlmvA0=; b=XHOSZBkNNWcTmnl0XWsVQEanDqE+zamjv4vwO/7OOpiEq0m0Wi+EDUZN6WnlrvuN+8 6SaMsC7TbD6Z83xTUQHtnr0V/66ZHAUBTAJcTeqJW/2lJNokPrWgwEbF3Ll9iNVvmYHc 8jx9IGlbzpg4KZCCcnWmQBWuau5+6KS8i5LXXz6mqImazHnmvRPJPctvXbzoScuNGwOX ANDuAfiJtqp/IiWPSZobMOBQYdBXOyMTE10n+0jGc1Y+CkD/A6DcwN329QB5SXE/NHo5 iZs4UKMQXtKZgJ2HD5AqXn6c7uhKMMXdCofBkwmSIAdqqydJX41RGOB9DGjt07z9QulK Afkw== X-Received: by 10.50.47.101 with SMTP id c5mr629146ign.32.1383705955758; Tue, 05 Nov 2013 18:45:55 -0800 (PST) Received: from raichu (24-212-218-13.cable.teksavvy.com. [24.212.218.13]) by mx.google.com with ESMTPSA id qi3sm11750428igc.8.2013.11.05.18.45.54 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 05 Nov 2013 18:45:54 -0800 (PST) Sender: Mark Johnston Date: Tue, 5 Nov 2013 21:45:49 -0500 From: Mark Johnston To: John Luk Subject: Re: dtrace showed matched probes but nothing in output on FreeBSD 9.1-RELEASE Message-ID: <20131106024549.GA2826@raichu> References: <20131103235936.GB15661@raichu> <20131104043519.GB8007@raichu> <20131104141105.GE8007@raichu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Cc: freebsd-dtrace@freebsd.org X-BeenThere: freebsd-dtrace@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "A discussion list for developers working on DTrace in FreeBSD." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 06 Nov 2013 02:45:56 -0000 On Tue, Nov 05, 2013 at 02:47:58PM +0800, John Luk wrote: > Hi, Mark. The gdb output is included below. I'm wondering why dtrace -l can > trace all my function correctly but the D script failed. Is it because they get > the symbol table in different way? Hm, I can't reproduce the problem using your binary on a machine running head. I suspect the problem has to do with some other DTrace bugs in the kernel which have been recently fixed - there were a couple that would corrupt the state of traced programs in various ways, and it could be that inet_makeaddr() really isn't getting called as a result. You could try adding a printf or something to see if that's the case. In general there have been quite a few DTrace fixes since 9.1, so it's worth trying out newer revisions if you're interested in trying out DTrace on FreeBSD. -Mark