From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Engestrom Subject: Re: [PATCH] i915: don't call drm_atomic_state_put on invalid pointer Date: Tue, 18 Oct 2016 16:29:08 +0100 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-Transfer-Encoding: base64 Return-path: Content-Disposition: inline In-Reply-To: <20161018151652.2690201-1-arnd@arndb.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Arnd Bergmann Cc: Ander Conselvan de Oliveira , David Airlie , Daniel Vetter , intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Daniel Vetter List-Id: dri-devel@lists.freedesktop.org T24gVHVlc2RheSwgMjAxNi0xMC0xOCAxNzoxNjoyMyArMDIwMCwgQXJuZCBCZXJnbWFubiB3cm90 ZToKPiBUaGUgaW50cm9kdWN0aW9uIG9mIHJlZmVyZW5jZSBjb3VudGluZyBvbiB0aGUgc3RhdGUg c3RydWN0dXJlcyBjYXVzZWQKPiBzYW5pdGl6ZV93YXRlcm1hcmtzKCkgaW4gaTkxNSB0byBicmVh ayBpbiB0aGUgZXJyb3IgaGFuZGxpbmcgY2FzZSwKPiBhcyBwb2ludGVkIG91dCBieSBnY2MgLVdt YXliZS11bmluaXRpYWxpemVkCj4gCj4gZHJpdmVycy9ncHUvZHJtL2k5MTUvaW50ZWxfZGlzcGxh eS5jOiBJbiBmdW5jdGlvbiDigJhpbnRlbF9tb2Rlc2V0X2luaXTigJk6Cj4gaW5jbHVkZS9kcm0v ZHJtX2F0b21pYy5oOjIyNDoyOiBlcnJvcjog4oCYc3RhdGXigJkgbWF5IGJlIHVzZWQgdW5pbml0 aWFsaXplZCBpbiB0aGlzIGZ1bmN0aW9uIFstV2Vycm9yPW1heWJlLXVuaW5pdGlhbGl6ZWRdCj4g Cj4gVGhpcyBjaGFuZ2VzIHRoZSBmdW5jdGlvbiBiYWNrIHRvIG9ubHkgZHJvcCB0aGUgcmVmZXJl bmNlIGNvdW50Cj4gd2hlbiBpdCB3YXMgc3VjY2Vzc2Z1bGx5IGFsbG9jYXRlZCBmaXJzdC4KPiAK PiBGaXhlczogMDg1MzY5NWMzYmE0ICgiZHJtOiBBZGQgcmVmZXJlbmNlIGNvdW50aW5nIHRvIGRy bV9hdG9taWNfc3RhdGUiKQo+IENjOiBDaHJpcyBXaWxzb24gPGNocmlzQGNocmlzLXdpbHNvbi5j by51az4KPiBDYzogRGFuaWVsIFZldHRlciA8ZGFuaWVsLnZldHRlckBmZndsbC5jaD4KPiBTaWdu ZWQtb2ZmLWJ5OiBBcm5kIEJlcmdtYW5uIDxhcm5kQGFybmRiLmRlPgoKUmV2aWV3ZWQtYnk6IEVy aWMgRW5nZXN0cm9tIDxlcmljLmVuZ2VzdHJvbUBpbWd0ZWMuY29tPgoKPiAtLS0KPiAgZHJpdmVy cy9ncHUvZHJtL2k5MTUvaW50ZWxfZGlzcGxheS5jIHwgNSArKystLQo+ICAxIGZpbGUgY2hhbmdl ZCwgMyBpbnNlcnRpb25zKCspLCAyIGRlbGV0aW9ucygtKQo+IAo+IGRpZmYgLS1naXQgYS9kcml2 ZXJzL2dwdS9kcm0vaTkxNS9pbnRlbF9kaXNwbGF5LmMgYi9kcml2ZXJzL2dwdS9kcm0vaTkxNS9p bnRlbF9kaXNwbGF5LmMKPiBpbmRleCA2ZDE2ODY4NWJiZGEuLjZhMjZkYTE0M2FhNiAxMDA2NDQK PiAtLS0gYS9kcml2ZXJzL2dwdS9kcm0vaTkxNS9pbnRlbF9kaXNwbGF5LmMKPiArKysgYi9kcml2 ZXJzL2dwdS9kcm0vaTkxNS9pbnRlbF9kaXNwbGF5LmMKPiBAQCAtMTYzMTQsNyArMTYzMTQsNyBA QCBzdGF0aWMgdm9pZCBzYW5pdGl6ZV93YXRlcm1hcmtzKHN0cnVjdCBkcm1fZGV2aWNlICpkZXYp Cj4gIAkJICogQklPUy1wcm9ncmFtbWVkIHdhdGVybWFya3MgdW50b3VjaGVkIGFuZCBob3BlIGZv ciB0aGUgYmVzdC4KPiAgCQkgKi8KPiAgCQlXQVJOKHRydWUsICJDb3VsZCBub3QgZGV0ZXJtaW5l IHZhbGlkIHdhdGVybWFya3MgZm9yIGluaGVyaXRlZCBzdGF0ZVxuIik7Cj4gLQkJZ290byBmYWls Owo+ICsJCWdvdG8gcHV0X3N0YXRlOwo+ICAJfQo+ICAKPiAgCS8qIFdyaXRlIGNhbGN1bGF0ZWQg d2F0ZXJtYXJrIHZhbHVlcyBiYWNrICovCj4gQEAgLTE2MzI1LDggKzE2MzI1LDkgQEAgc3RhdGlj IHZvaWQgc2FuaXRpemVfd2F0ZXJtYXJrcyhzdHJ1Y3QgZHJtX2RldmljZSAqZGV2KQo+ICAJCWRl dl9wcml2LT5kaXNwbGF5Lm9wdGltaXplX3dhdGVybWFya3MoY3MpOwo+ICAJfQo+ICAKPiAtZmFp bDoKPiArcHV0X3N0YXRlOgo+ICAJZHJtX2F0b21pY19zdGF0ZV9wdXQoc3RhdGUpOwo+ICtmYWls Ogo+ICAJZHJtX21vZGVzZXRfZHJvcF9sb2NrcygmY3R4KTsKPiAgCWRybV9tb2Rlc2V0X2FjcXVp cmVfZmluaSgmY3R4KTsKPiAgfQo+IC0tIAo+IDIuOS4wCl9fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fCkludGVsLWdmeCBtYWlsaW5nIGxpc3QKSW50ZWwtZ2Z4 QGxpc3RzLmZyZWVkZXNrdG9wLm9yZwpodHRwczovL2xpc3RzLmZyZWVkZXNrdG9wLm9yZy9tYWls bWFuL2xpc3RpbmZvL2ludGVsLWdmeAo= From mboxrd@z Thu Jan 1 00:00:00 1970 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 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