From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F1216C432C0 for ; Fri, 29 Nov 2019 18:03:55 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A54B82158A for ; Fri, 29 Nov 2019 18:03:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="iMe7FaBj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A54B82158A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:33334 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iakcU-000260-Mg for qemu-devel@archiver.kernel.org; Fri, 29 Nov 2019 13:03:54 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:55818) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iaka5-0000qT-0P for qemu-devel@nongnu.org; Fri, 29 Nov 2019 13:01:29 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iakZz-00023U-8V for qemu-devel@nongnu.org; Fri, 29 Nov 2019 13:01:21 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:43725 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iakZw-0001xz-84 for qemu-devel@nongnu.org; Fri, 29 Nov 2019 13:01:17 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1575050468; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=X5u1/UP9ViJmraIHgBX1gw8H4uE9NUjyP4nOUVJwPFY=; b=iMe7FaBjnn3JV+I7GOT2rDiliAERE2MChGblhAqXdSYywQMOGDCr+dAurPhB3Uq3a36XHp MFzuwtMi0i1KIOkuk+0Q3QTb66PkxcoPrI+ncLD+1NYR3qK/DpQowIPtEfuBgyldtQZ5nY oE6muigfCzKG5KyB48pUxGmS+080+rk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-20-x_j8Ii5APySfMLHZ76lc9w-1; Fri, 29 Nov 2019 13:01:07 -0500 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9CF7880183C for ; Fri, 29 Nov 2019 18:01:06 +0000 (UTC) Received: from work-vm (ovpn-117-253.ams2.redhat.com [10.36.117.253]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 730CE60904; Fri, 29 Nov 2019 18:01:05 +0000 (UTC) Date: Fri, 29 Nov 2019 18:01:03 +0000 From: "Dr. David Alan Gilbert" To: Paolo Bonzini Subject: Re: libcap vs libcap-ng mess Message-ID: <20191129180103.GA2840@work-vm> References: <20191128190408.GC3294@work-vm> <20191129093409.GB2260471@redhat.com> <98520a07-cf5d-a2a9-cfa4-944839b94c7c@redhat.com> MIME-Version: 1.0 In-Reply-To: <98520a07-cf5d-a2a9-cfa4-944839b94c7c@redhat.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-MC-Unique: x_j8Ii5APySfMLHZ76lc9w-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 205.139.110.120 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: thuth@redhat.com, Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= , qemu-devel@nongnu.org, vgoyal@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Paolo Bonzini (pbonzini@redhat.com) wrote: > On 29/11/19 10:34, Daniel P. Berrang=E9 wrote: > >> y) Should we flip over to only using one or the other - what > >> are the advantages? > > In libvirt we use libcap-ng. We picked this originally as its API > > design allows you do write simpler code than libcap in some cases > > You can see some docs & examples here: > >=20 > > https://people.redhat.com/sgrubb/libcap-ng/ > >=20 > > So I vote for changing the 9p code to use libcap-ng. >=20 > It's not entirely trivial because fsdev-proxy-helper wants to keep the > effective set and clear the permitted set; in libcap-ng you can only > apply both sets at once, and you cannot choose only one of them in > capng_clear/capng_get_caps_process. But it's doable, I'll take a look. I'm having some difficulties making the same conversion for virtiofsd; all it wants to do is drop (and later recover) CAP_FSETID from it's effective set; so I'm calling capng_get_caps_process (it used to be cap_get_proc). While libcap survives just using the capget syscall, libcap-ng wants to read /proc//status - and that's a problem because we're in a sandbox without /proc mounted at that point. Dave > In the meanwhile, if someone else wants to look at the CI I would > appreciate that. >=20 > Paolo >=20 >=20 -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK