From patchwork Tue Jul 1 18:17:39 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 4461141 Return-Path: X-Original-To: patchwork-intel-gfx@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id DE39EBEEAA for ; Tue, 1 Jul 2014 18:18:13 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 09B9820395 for ; Tue, 1 Jul 2014 18:18:13 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id B003D202F0 for ; Tue, 1 Jul 2014 18:18:11 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DB4B76E1F5; Tue, 1 Jul 2014 11:18:09 -0700 (PDT) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by gabe.freedesktop.org (Postfix) with ESMTP id DE4D16E1E0 for ; Tue, 1 Jul 2014 11:18:08 -0700 (PDT) Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga101.jf.intel.com with ESMTP; 01 Jul 2014 11:18:07 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,583,1400050800"; d="scan'208";a="537317958" Received: from ironside.jf.intel.com ([10.7.197.210]) by orsmga001.jf.intel.com with ESMTP; 01 Jul 2014 11:17:53 -0700 From: Ben Widawsky To: Intel GFX Date: Tue, 1 Jul 2014 11:17:39 -0700 Message-Id: <1404238671-18760-5-git-send-email-benjamin.widawsky@intel.com> X-Mailer: git-send-email 2.0.1 In-Reply-To: <1404238671-18760-1-git-send-email-benjamin.widawsky@intel.com> References: <1404238671-18760-1-git-send-email-benjamin.widawsky@intel.com> Cc: Ben Widawsky , Ben Widawsky Subject: [Intel-gfx] [PATCH 04/16] drm/i915: Fix another another use-after-free in do_switch X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_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 X-Virus-Scanned: ClamAV using ClamSMTP See the following for many more details. commit acc240d41ea1ab9c488a79219fb313b5b46265ae Author: Daniel Vetter Date: Thu Dec 5 15:42:34 2013 +0100 drm/i915: Fix use-after-free in do_switch In this case, the issue is only for full PPGTT: do_switch context_unref ppgtt_release i915_gpu_idle switch_to_default from changes to default context This could be backported to the pre do_switch cleanup I did in this series. However, it's much cleaner and more obvious as a patch on top, so I'd really like to do this as a post cleanup patch. Signed-off-by: Ben Widawsky --- drivers/gpu/drm/i915/i915_gem_context.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c index 601a58f..0e6e743 100644 --- a/drivers/gpu/drm/i915/i915_gem_context.c +++ b/drivers/gpu/drm/i915/i915_gem_context.c @@ -745,13 +745,21 @@ static int do_switch_rcs(struct intel_engine_cs *ring, from->obj->dirty = 1; BUG_ON(from->obj->ring != ring); - /* obj is kept alive until the next request by its active ref */ - i915_gem_object_ggtt_unpin(from->obj); } uninitialized = !to->is_initialized && from == NULL; to->is_initialized = true; do_switch_fini_common(ring, from, to); + /* From may have disappeared again after thecontext unref */ + from = ring->last_context; + if (from != NULL) { + /* obj is kept alive until the next request by its active ref. + * XXX: The context needs to be unpinned last, or else we risk + * hitting evict/idle on the ppgtt free, which will call back + * into this, and we'll get a double unpin on this context + */ + i915_gem_object_ggtt_unpin(from->obj); + } if (uninitialized) { ret = i915_gem_render_state_init(ring);