Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935677AbcJRP3U (ORCPT ); Tue, 18 Oct 2016 11:29:20 -0400 Received: from mailapp02.imgtec.com ([217.156.133.132]:20298 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S935077AbcJRP3L (ORCPT ); Tue, 18 Oct 2016 11:29:11 -0400 Date: Tue, 18 Oct 2016 16:29:08 +0100 From: Eric Engestrom To: Arnd Bergmann CC: Daniel Vetter , Jani Nikula , David Airlie , "Ander Conselvan de Oliveira" , Daniel Vetter , , , Subject: Re: [PATCH] i915: don't call drm_atomic_state_put on invalid pointer Message-ID: <20161018152908.GI3759@imgtec.com> References: <20161018151652.2690201-1-arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20161018151652.2690201-1-arnd@arndb.de> User-Agent: Mutt/1.7.1 (2016-10-04) X-Originating-IP: [10.60.4.28] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1801 Lines: 48 On Tuesday, 2016-10-18 17:16:23 +0200, Arnd Bergmann wrote: > The introduction of reference counting on the state structures caused > sanitize_watermarks() in i915 to break in the error handling case, > as pointed out by gcc -Wmaybe-uninitialized > > drivers/gpu/drm/i915/intel_display.c: In function ‘intel_modeset_init’: > include/drm/drm_atomic.h:224:2: error: ‘state’ may be used uninitialized in this function [-Werror=maybe-uninitialized] > > This changes the function back to only drop the reference count > when it was successfully allocated first. > > Fixes: 0853695c3ba4 ("drm: Add reference counting to drm_atomic_state") > Cc: Chris Wilson > Cc: Daniel Vetter > Signed-off-by: Arnd Bergmann Reviewed-by: Eric Engestrom > --- > drivers/gpu/drm/i915/intel_display.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c > index 6d168685bbda..6a26da143aa6 100644 > --- a/drivers/gpu/drm/i915/intel_display.c > +++ b/drivers/gpu/drm/i915/intel_display.c > @@ -16314,7 +16314,7 @@ static void sanitize_watermarks(struct drm_device *dev) > * BIOS-programmed watermarks untouched and hope for the best. > */ > WARN(true, "Could not determine valid watermarks for inherited state\n"); > - goto fail; > + goto put_state; > } > > /* Write calculated watermark values back */ > @@ -16325,8 +16325,9 @@ static void sanitize_watermarks(struct drm_device *dev) > dev_priv->display.optimize_watermarks(cs); > } > > -fail: > +put_state: > drm_atomic_state_put(state); > +fail: > drm_modeset_drop_locks(&ctx); > drm_modeset_acquire_fini(&ctx); > } > -- > 2.9.0