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=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 71DFEC31E40 for ; Mon, 12 Aug 2019 16:36:10 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 3B19320679 for ; Mon, 12 Aug 2019 16:36:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="UzQg2Hzr"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=ti.com header.i=@ti.com header.b="LpKMdEDM" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3B19320679 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=ti.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:From:References:To:Subject:Reply-To:Content-ID:Content-Description :Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=zTgRQtbhJkHJCPBxsOSWB4rlkmneOlgSuEa/Qe86zJc=; b=UzQg2HzrnWRXsS zUo/ldjeRP86uQL/kGflEM4AclCUXbPywCJYk4glE1eF+nJVtDuCMEvHgERXsTztwaa5P9QCeXCSs jpSHERZXPsztMQsJwseV8p1+PAETDudRzvv7J1nvxKrm5f+rmWFEjapu2BZMy0vOmlJxzlLJVhS4e 1Nd3BtwVPmpZ0XTFqTgArIUprDC5jtjqYCUxmiWroLfzaoBCvjsVxvFmkt1Do8F2xux/LQLzNS17T q2rJ2Iheay2CJh9JitUd1OLtC47AG+hxG59nzVSHaVAPYzTe53xEUn7f9b5DxDhW7XV6Q3XvztJ4l q+qmmnqoCFXFUVWEAA9w==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hxDIn-00060F-L5; Mon, 12 Aug 2019 16:36:09 +0000 Received: from lelv0143.ext.ti.com ([198.47.23.248]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hxDIk-0005yp-Or for linux-arm-kernel@lists.infradead.org; Mon, 12 Aug 2019 16:36:08 +0000 Received: from fllv0035.itg.ti.com ([10.64.41.0]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id x7CGa5w7038570; Mon, 12 Aug 2019 11:36:05 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1565627765; bh=T2phpgm+NARzJAyCB2+UTr9p6Cxo5E7SZBGs4Cpo3zo=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=LpKMdEDMQhXB4jMb2oafcKkPFCB8q7ubinXIphDr0YOVHeNKsWh7ytwbeM5Pt5iAW NIUORjWZKvwnyPovIlEnqLTh6zJacNOGBStB6M0y7/7peLmIwqUzxTVQIxCkUdFUgY fR8O6VolvFyHcjTGLVuov7p0VMn196fLsLTp+zOs= Received: from DLEE109.ent.ti.com (dlee109.ent.ti.com [157.170.170.41]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTPS id x7CGa5xS076195 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 12 Aug 2019 11:36:05 -0500 Received: from DLEE102.ent.ti.com (157.170.170.32) by DLEE109.ent.ti.com (157.170.170.41) 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 11:36:04 -0500 Received: from fllv0040.itg.ti.com (10.64.41.20) by DLEE102.ent.ti.com (157.170.170.32) 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 11:36:04 -0500 Received: from [10.250.88.190] (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0040.itg.ti.com (8.15.2/8.15.2) with ESMTP id x7CGa4Fa112134; Mon, 12 Aug 2019 11:36:04 -0500 Subject: Re: [PATCH] rpmsg: virtio_rpmsg_bus: replace "%p" with "%pK" To: Suman Anna , Bjorn Andersson References: <20181024011909.21674-1-s-anna@ti.com> <1cc3d697-6fde-901b-2e35-2e2b53b44425@ti.com> <2ef5e274-df09-c3a0-41ed-a945d1902eaf@ti.com> From: "Andrew F. Davis" Message-ID: <92dc4403-8782-8dbf-b912-cc832ac748a7@ti.com> Date: Mon, 12 Aug 2019 12:36:04 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <2ef5e274-df09-c3a0-41ed-a945d1902eaf@ti.com> Content-Language: en-US X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190812_093606_895485_526CDD6A X-CRM114-Status: GOOD ( 18.10 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arm-kernel@lists.infradead.org, linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org, Loic Pallardy Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 8/12/19 12:28 PM, Suman Anna wrote: > 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. > Let me rephrase then, why would you ever set 'kptr_restrict' to anything other than 0, or why do you want to be able to leak this address to userspace at all? If the answer is just because you can, then all 12,000 instances of %p in kernel could be converted for the same reason. Andrew > 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 */ >>> > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel