From patchwork Tue Oct 21 10:51:13 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dheeraj Jamwal X-Patchwork-Id: 5117871 Return-Path: X-Original-To: patchwork-ltsi-dev@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 719CB9F349 for ; Tue, 21 Oct 2014 11:37:23 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id A66A820138 for ; Tue, 21 Oct 2014 11:37:22 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C861420121 for ; Tue, 21 Oct 2014 11:37:21 +0000 (UTC) Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 02FA0C43; Tue, 21 Oct 2014 11:06:26 +0000 (UTC) X-Original-To: ltsi-dev@lists.linuxfoundation.org Delivered-To: ltsi-dev@mail.linuxfoundation.org Received: from smtp2.linuxfoundation.org (smtp2.linux-foundation.org [172.17.192.36]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 08C55FA0 for ; Tue, 21 Oct 2014 11:06:23 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by smtp2.linuxfoundation.org (Postfix) with ESMTP id A73551DD41 for ; Tue, 21 Oct 2014 11:06:22 +0000 (UTC) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga101.fm.intel.com with ESMTP; 21 Oct 2014 04:06:22 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,761,1406617200"; d="scan'208";a="617796471" Received: from ubuntu-desktop.png.intel.com ([10.221.122.25]) by fmsmga002.fm.intel.com with ESMTP; 21 Oct 2014 04:06:21 -0700 From: Dheeraj Jamwal To: ltsi-dev@lists.linuxfoundation.org Date: Tue, 21 Oct 2014 18:51:13 +0800 Message-Id: <1413889294-31328-474-git-send-email-dheerajx.s.jamwal@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1413889294-31328-1-git-send-email-dheerajx.s.jamwal@intel.com> References: <1413889294-31328-1-git-send-email-dheerajx.s.jamwal@intel.com> X-Spam-Status: No, score=-5.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org Subject: [LTSI-dev] [PATCH 0473/1094] drm/i915: Do not dereference pointers from ring buffer in evict event X-BeenThere: ltsi-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: "A list to discuss patches, development, and other things related to the LTSI project" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: ltsi-dev-bounces@lists.linuxfoundation.org Errors-To: ltsi-dev-bounces@lists.linuxfoundation.org X-Virus-Scanned: ClamAV using ClamSMTP From: Steven Rostedt The TP_printk() should never dereference any pointers, because the ring buffer can be read at some unknown time in the future. If a device no longer exists, it can cause a kernel oops. This also makes this event useless when saving the ring buffer in userspaces tools such as perf and trace-cmd. The i915_gem_evict_vm dereferences the vm pointer which may also not exist when the ring buffer is read sometime in the future. Link: http://lkml.kernel.org/r/1395095198-20034-3-git-send-email-artagnon@gmail.com Reported-by: Ramkumar Ramachandra Cc: stable@vger.kernel.org # 3.13+ Fixes: bcccff847d1f "drm/i915: trace vm eviction instead of everything" Signed-off-by: Steven Rostedt [danvet: Try to make it actually compile] Signed-off-by: Daniel Vetter (cherry picked from commit 9297ebf29ad9118edd6c0fedc84f03e35028827d) Signed-off-by: Dheeraj Jamwal --- drivers/gpu/drm/i915/i915_trace.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h index b95a380..23c26f1 100644 --- a/drivers/gpu/drm/i915/i915_trace.h +++ b/drivers/gpu/drm/i915/i915_trace.h @@ -238,14 +238,16 @@ TRACE_EVENT(i915_gem_evict_vm, TP_ARGS(vm), TP_STRUCT__entry( + __field(u32, dev) __field(struct i915_address_space *, vm) ), TP_fast_assign( + __entry->dev = vm->dev->primary->index; __entry->vm = vm; ), - TP_printk("dev=%d, vm=%p", __entry->vm->dev->primary->index, __entry->vm) + TP_printk("dev=%d, vm=%p", __entry->dev, __entry->vm) ); TRACE_EVENT(i915_gem_ring_sync_to,