From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:47944) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R0gYZ-0005Wh-Ek for qemu-devel@nongnu.org; Mon, 05 Sep 2011 17:18:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1R0gYY-0000MG-8r for qemu-devel@nongnu.org; Mon, 05 Sep 2011 17:18:15 -0400 Received: from fmmailgate03.web.de ([217.72.192.234]:53751) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R0gYX-0000M7-Ud for qemu-devel@nongnu.org; Mon, 05 Sep 2011 17:18:14 -0400 Message-ID: <4E653C6B.9010106@web.de> Date: Mon, 05 Sep 2011 23:17:31 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <1315237048-3498-1-git-send-email-stefanha@linux.vnet.ibm.com> In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigFEA1B063A20EE6D9FFB886E0" Sender: jan.kiszka@web.de Subject: Re: [Qemu-devel] [PATCH 1/2] trace: allow trace events with string arguments List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Blue Swirl Cc: Stefan Hajnoczi , qemu-devel This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigFEA1B063A20EE6D9FFB886E0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 2011-09-05 21:45, Blue Swirl wrote: > On Mon, Sep 5, 2011 at 3:37 PM, Stefan Hajnoczi > wrote: >> String arguments are useful for producing human-readable traces withou= t >> post-processing (e.g. stderr backend). Although the simple backend >> cannot handles strings all others can. Strings should be allowed and >> the simple backend can be extended to support them. >=20 > I don't think this is possible in general. Yes if the string can be > found in the executable (assuming address space randomizations don't > make that impossible post run), but not if the string happens to be > constructed in the stack or in the data segment during run time. Strings can be addressed in tracers like simpletrace by storing a fixed-size copy (e.g. 64 chars) in the log. That will work out for the majority of use cases. Jan --------------enigFEA1B063A20EE6D9FFB886E0 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.16 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk5lPG4ACgkQitSsb3rl5xR0IwCfcW+BbichPktIFKAWDwQRF3Ph sQMAn3MBLGFvd5VRIuLEiDaDZsU8tcGo =tAf9 -----END PGP SIGNATURE----- --------------enigFEA1B063A20EE6D9FFB886E0--