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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 0DFA6C3A5A2 for ; Tue, 3 Sep 2019 20:49:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D5CA72341F for ; Tue, 3 Sep 2019 20:49:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728460AbfICUtU (ORCPT ); Tue, 3 Sep 2019 16:49:20 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47156 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728358AbfICUtR (ORCPT ); Tue, 3 Sep 2019 16:49:17 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 32A383082141; Tue, 3 Sep 2019 20:49:17 +0000 (UTC) Received: from malachite.bss.redhat.com (dhcp-10-20-1-34.bss.redhat.com [10.20.1.34]) by smtp.corp.redhat.com (Postfix) with ESMTP id E6E5D1001B08; Tue, 3 Sep 2019 20:49:15 +0000 (UTC) From: Lyude Paul To: dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org, amd-gfx@lists.freedesktop.org Cc: Juston Li , Imre Deak , =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= , Harry Wentland , Daniel Vetter , Maarten Lankhorst , Maxime Ripard , Sean Paul , David Airlie , Daniel Vetter , linux-kernel@vger.kernel.org Subject: [PATCH v2 26/27] drm/dp_mst: Also print unhashed pointers for malloc/topology references Date: Tue, 3 Sep 2019 16:46:04 -0400 Message-Id: <20190903204645.25487-27-lyude@redhat.com> In-Reply-To: <20190903204645.25487-1-lyude@redhat.com> References: <20190903204645.25487-1-lyude@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Tue, 03 Sep 2019 20:49:17 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently we only print mstb/port pointer addresses in our malloc and topology refcount functions using the hashed-by-default %p, but unfortunately if you're trying to debug a use-after-free error caused by a refcounting error then this really isn't terribly useful. On the other hand though, everything in the rest of the DP MST helpers uses hashed pointer values as well and probably isn't useful to convert to unhashed. So, let's just get the best of both worlds and print both the hashed and unhashed pointer in our malloc/topology refcount debugging output. This will hopefully make it a lot easier to figure out which port/mstb is causing KASAN to get upset. Cc: Juston Li Cc: Imre Deak Cc: Ville Syrjälä Cc: Harry Wentland Cc: Daniel Vetter Signed-off-by: Lyude Paul --- drivers/gpu/drm/drm_dp_mst_topology.c | 34 ++++++++++++++++----------- 1 file changed, 20 insertions(+), 14 deletions(-) diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 2fe24e366925..5b5c0b3b3c0e 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1327,7 +1327,8 @@ static void drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb) { kref_get(&mstb->malloc_kref); - DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref)); + DRM_DEBUG("mstb %p/%px (%d)\n", + mstb, mstb, kref_read(&mstb->malloc_kref)); } /** @@ -1344,7 +1345,8 @@ drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb) static void drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb) { - DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1); + DRM_DEBUG("mstb %p/%px (%d)\n", + mstb, mstb, kref_read(&mstb->malloc_kref) - 1); kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device); } @@ -1379,7 +1381,8 @@ void drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port) { kref_get(&port->malloc_kref); - DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref)); + DRM_DEBUG("port %p/%px (%d)\n", + port, port, kref_read(&port->malloc_kref)); } EXPORT_SYMBOL(drm_dp_mst_get_port_malloc); @@ -1396,7 +1399,8 @@ EXPORT_SYMBOL(drm_dp_mst_get_port_malloc); void drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port) { - DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1); + DRM_DEBUG("port %p/%px (%d)\n", + port, port, kref_read(&port->malloc_kref) - 1); kref_put(&port->malloc_kref, drm_dp_free_mst_port); } EXPORT_SYMBOL(drm_dp_mst_put_port_malloc); @@ -1447,8 +1451,8 @@ drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch *mstb) int ret = kref_get_unless_zero(&mstb->topology_kref); if (ret) - DRM_DEBUG("mstb %p (%d)\n", mstb, - kref_read(&mstb->topology_kref)); + DRM_DEBUG("mstb %p/%px (%d)\n", + mstb, mstb, kref_read(&mstb->topology_kref)); return ret; } @@ -1471,7 +1475,8 @@ static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb) { WARN_ON(kref_read(&mstb->topology_kref) == 0); kref_get(&mstb->topology_kref); - DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref)); + DRM_DEBUG("mstb %p/%px (%d)\n", + mstb, mstb, kref_read(&mstb->topology_kref)); } /** @@ -1489,8 +1494,8 @@ static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb) static void drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch *mstb) { - DRM_DEBUG("mstb %p (%d)\n", - mstb, kref_read(&mstb->topology_kref) - 1); + DRM_DEBUG("mstb %p/%px (%d)\n", + mstb, mstb, kref_read(&mstb->topology_kref) - 1); kref_put(&mstb->topology_kref, drm_dp_destroy_mst_branch_device); } @@ -1546,8 +1551,8 @@ drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port *port) int ret = kref_get_unless_zero(&port->topology_kref); if (ret) - DRM_DEBUG("port %p (%d)\n", port, - kref_read(&port->topology_kref)); + DRM_DEBUG("port %p/%px (%d)\n", + port, port, kref_read(&port->topology_kref)); return ret; } @@ -1569,7 +1574,8 @@ static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port) { WARN_ON(kref_read(&port->topology_kref) == 0); kref_get(&port->topology_kref); - DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->topology_kref)); + DRM_DEBUG("port %p/%px (%d)\n", + port, port, kref_read(&port->topology_kref)); } /** @@ -1585,8 +1591,8 @@ static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port) */ static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port) { - DRM_DEBUG("port %p (%d)\n", - port, kref_read(&port->topology_kref) - 1); + DRM_DEBUG("port %p/%px (%d)\n", + port, port, kref_read(&port->topology_kref) - 1); kref_put(&port->topology_kref, drm_dp_destroy_port); } -- 2.21.0