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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 5E42CC31E40 for ; Mon, 12 Aug 2019 16:28:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 329602075B for ; Mon, 12 Aug 2019 16:28:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="k1vjYN/u" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726987AbfHLQ2h (ORCPT ); Mon, 12 Aug 2019 12:28:37 -0400 Received: from fllv0015.ext.ti.com ([198.47.19.141]:41740 "EHLO fllv0015.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725843AbfHLQ2g (ORCPT ); Mon, 12 Aug 2019 12:28:36 -0400 Received: from lelv0266.itg.ti.com ([10.180.67.225]) by fllv0015.ext.ti.com (8.15.2/8.15.2) with ESMTP id x7CGSSO6082982; Mon, 12 Aug 2019 11:28:28 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1565627308; bh=IsKWgqgOglbaA6eYIe/r12Zf5tXCWsmgx1YMeflw7pY=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=k1vjYN/uiF81v43522pzxwnJM4QIt1smtzfCqAKw3TsOp5y3pigH2fwmguZGIpBV0 f4F4jQPxhApuQ/gfhORnEtUSVrccfREOb7LHI4URSZ7wcH7fgQyDF5rULGOY5kJqf4 OMgA6bShR1TPvJNx2CNByzAdBdw6d0sdEM4e2DY4= Received: from DFLE108.ent.ti.com (dfle108.ent.ti.com [10.64.6.29]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id x7CGSSbf067422 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 12 Aug 2019 11:28:28 -0500 Received: from DFLE114.ent.ti.com (10.64.6.35) by DFLE108.ent.ti.com (10.64.6.29) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Mon, 12 Aug 2019 11:28:27 -0500 Received: from lelv0327.itg.ti.com (10.180.67.183) by DFLE114.ent.ti.com (10.64.6.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5 via Frontend Transport; Mon, 12 Aug 2019 11:28:27 -0500 Received: from [128.247.58.153] (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0327.itg.ti.com (8.15.2/8.15.2) with ESMTP id x7CGSRX0093082; Mon, 12 Aug 2019 11:28:27 -0500 Subject: Re: [PATCH] rpmsg: virtio_rpmsg_bus: replace "%p" with "%pK" To: "Andrew F. Davis" , Bjorn Andersson CC: , Loic Pallardy , , References: <20181024011909.21674-1-s-anna@ti.com> <1cc3d697-6fde-901b-2e35-2e2b53b44425@ti.com> From: Suman Anna Message-ID: <2ef5e274-df09-c3a0-41ed-a945d1902eaf@ti.com> Date: Mon, 12 Aug 2019 11:28:27 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <1cc3d697-6fde-901b-2e35-2e2b53b44425@ti.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/12/19 10:47 AM, Andrew F. Davis wrote: > On 10/23/18 9:19 PM, Suman Anna wrote: >> The virtio_rpmsg_bus driver uses the "%p" format-specifier for >> printing the vring buffer address. This prints only a hashed >> pointer even for previliged users. Use "%pK" instead so that >> the address can be printed during debug using kptr_restrict >> sysctl. >> > > > s/previliged/privileged Bjorn, Can you fix this up when applying. > > You describe what the code does, but not why you need this. %pK is used > for only about 1% of pointer printing, why do you want to leak this > address to userspace at all? Andrew, Default behavior of %pK is same as %p, but it does allow you to control the print. The reason is clearly mentioned in the last sentence in the patch description. regards Suman > > Andrew > > >> Signed-off-by: Suman Anna >> --- >> drivers/rpmsg/virtio_rpmsg_bus.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c >> index f29dee731026..1345f373a1a0 100644 >> --- a/drivers/rpmsg/virtio_rpmsg_bus.c >> +++ b/drivers/rpmsg/virtio_rpmsg_bus.c >> @@ -950,7 +950,7 @@ static int rpmsg_probe(struct virtio_device *vdev) >> goto vqs_del; >> } >> >> - dev_dbg(&vdev->dev, "buffers: va %p, dma %pad\n", >> + dev_dbg(&vdev->dev, "buffers: va %pK, dma %pad\n", >> bufs_va, &vrp->bufs_dma); >> >> /* half of the buffers is dedicated for RX */ >>