From patchwork Wed May 2 18:32:47 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?VmlsbGUgU3lyasOkbMOk?= X-Patchwork-Id: 10376307 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id AE83A60384 for ; Wed, 2 May 2018 18:32:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9FF7328462 for ; Wed, 2 May 2018 18:32:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 94FCB2858F; Wed, 2 May 2018 18:32:56 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 5914E28462 for ; Wed, 2 May 2018 18:32:56 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9183F6E5AB; Wed, 2 May 2018 18:32:54 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by gabe.freedesktop.org (Postfix) with ESMTPS id C55366E5A2; Wed, 2 May 2018 18:32:52 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 02 May 2018 11:32:51 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,354,1520924400"; d="scan'208";a="37918793" Received: from stinkbox.fi.intel.com (HELO stinkbox) ([10.237.72.174]) by orsmga007.jf.intel.com with SMTP; 02 May 2018 11:32:48 -0700 Received: by stinkbox (sSMTP sendmail emulation); Wed, 02 May 2018 21:32:47 +0300 From: Ville Syrjala To: dri-devel@lists.freedesktop.org Date: Wed, 2 May 2018 21:32:47 +0300 Message-Id: <20180502183247.5746-1-ville.syrjala@linux.intel.com> X-Mailer: git-send-email 2.16.1 MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH] drm/atomic: Clean old_state/new_state in drm_atomic_state_default_clear() X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx@lists.freedesktop.org, Laurent Pinchart , stable@vger.kernel.org Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP From: Ville Syrjälä Clear the old_state and new_state pointers for every object in drm_atomic_state_default_clear(). Otherwise drm_atomic_get_{new,old}_*_state() will hand out stale pointers to anyone who hasn't first confirmed that the object is in fact part of the current atomic transcation, if they are called after we've done the ww backoff dance while hanging on to the same drm_atomic_state. For example, handle_conflicting_encoders() looks like it could hit this since it iterates the full connector list and just calls drm_atomic_get_new_connector_state() for each. And I believe we have now witnessed this happening at least once in i915 check_digital_port_conflicts(). Commit 8b69449d2663 ("drm/i915: Remove last references to drm_atomic_get_existing* macros") changed the safe drm_atomic_get_existing_connector_state() to the unsafe drm_atomic_get_new_connector_state(), which opened the doors for this particular bug there as well. Cc: stable@vger.kernel.org Cc: Maarten Lankhorst Cc: Laurent Pinchart Cc: Abhay Kumar Fixes: 581e49fe6b41 ("drm/atomic: Add new iterators over all state, v3.") Signed-off-by: Ville Syrjälä Reviewed-by: Daniel Vetter Reviewed-by: Maarten Lankhorst --- drivers/gpu/drm/drm_atomic.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c index 7d25c42f22db..c825c76edc1d 100644 --- a/drivers/gpu/drm/drm_atomic.c +++ b/drivers/gpu/drm/drm_atomic.c @@ -155,6 +155,8 @@ void drm_atomic_state_default_clear(struct drm_atomic_state *state) state->connectors[i].state); state->connectors[i].ptr = NULL; state->connectors[i].state = NULL; + state->connectors[i].old_state = NULL; + state->connectors[i].new_state = NULL; drm_connector_put(connector); } @@ -169,6 +171,8 @@ void drm_atomic_state_default_clear(struct drm_atomic_state *state) state->crtcs[i].ptr = NULL; state->crtcs[i].state = NULL; + state->crtcs[i].old_state = NULL; + state->crtcs[i].new_state = NULL; } for (i = 0; i < config->num_total_plane; i++) { @@ -181,6 +185,8 @@ void drm_atomic_state_default_clear(struct drm_atomic_state *state) state->planes[i].state); state->planes[i].ptr = NULL; state->planes[i].state = NULL; + state->planes[i].old_state = NULL; + state->planes[i].new_state = NULL; } for (i = 0; i < state->num_private_objs; i++) { @@ -190,6 +196,8 @@ void drm_atomic_state_default_clear(struct drm_atomic_state *state) state->private_objs[i].state); state->private_objs[i].ptr = NULL; state->private_objs[i].state = NULL; + state->private_objs[i].old_state = NULL; + state->private_objs[i].new_state = NULL; } state->num_private_objs = 0;