From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9FC53C61DBD for ; Wed, 26 Aug 2026 17:31:54 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F2C4210E2DE; Wed, 26 Aug 2026 17:31:53 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="gyWKNkeW"; dkim-atps=neutral Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1424D10E2DE for ; Wed, 26 Aug 2026 17:31:52 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id AF358439C2; Wed, 26 Aug 2026 17:31:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0108C1F000E9; Wed, 26 Aug 2026 17:31:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787765511; bh=R2QETYhPvOkKMoNnjxG/pbHN+lDuCwiTNOHlDphWmdY=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=gyWKNkeWgxc0wmb+3f0YGy4d/OC9W2abR2lEu3C2yXoMb+Q2uvElSwaV1BOi15UIT h6XYlUqp/XTuaTbnXEiEgC/zTPF8/CTz89sq3n/RUAD1Zlw/1LJFwSd+XEyBcs0IeK tbUT0qb+VQH7Ws/pIwM6LDLR5Rr/Y+tcCjwuqbGq7oyD69LoTxPocruEkDt83NDesa c+ulnq6RoP0no6xsoZ4dnuZu5HN0OSGpTTuh4VxSE7Fgzl20I5VRioqD9jfQiJ+1Wa XZciEWJ1ElNMLjaod/TN+3NjJTihi2YbnWGYGZoKExXAFe6xuyZYiH/tDCNSNJ2Oae 4qkbl/AtgliAA== Date: Wed, 26 Aug 2026 19:31:48 +0200 From: Andi Shyti To: Sebastian Brzezinka Cc: intel-gfx@lists.freedesktop.org, andi.shyti@linux.intel.com, krzysztof.karas@intel.com, krzysztof.niemiec@intel.com, chris.p.wilson@intel.com Subject: Re: [PATCH] drm/i915/selftests: Fix unlocked mm.stolen in reset selftest Message-ID: References: <20260821134044.15908-1-sebastian.brzezinka@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260821134044.15908-1-sebastian.brzezinka@intel.com> X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Hi Sebastian, Have you checked sashiko's reviews? They look valid to me. ... > @@ -95,9 +96,12 @@ __igt_reset_stolen(struct intel_gt *gt, > ggtt->error_capture.start, > PAGE_SIZE); > > - if (!__drm_mm_interval_first(>->i915->mm.stolen, > - page << PAGE_SHIFT, > - ((page + 1) << PAGE_SHIFT) - 1)) > + mutex_lock(>->i915->mm.stolen_lock); > + unused = !__drm_mm_interval_first(>->i915->mm.stolen, > + page << PAGE_SHIFT, > + ((page + 1) << PAGE_SHIFT) - 1); > + mutex_unlock(>->i915->mm.stolen_lock); > + if (unused) this is always false. > memset_io(s, STACK_MAGIC, PAGE_SIZE); And this needs to be inside the lock. > > in = (void __force *)s; > @@ -143,10 +147,12 @@ __igt_reset_stolen(struct intel_gt *gt, > in = tmp; > x = crc32_le(0, in, PAGE_SIZE); > > - if (x != crc[page] && > - !__drm_mm_interval_first(>->i915->mm.stolen, > - page << PAGE_SHIFT, > - ((page + 1) << PAGE_SHIFT) - 1)) { > + mutex_lock(>->i915->mm.stolen_lock); > + unused = !__drm_mm_interval_first(>->i915->mm.stolen, > + page << PAGE_SHIFT, > + ((page + 1) << PAGE_SHIFT) - 1); > + mutex_unlock(>->i915->mm.stolen_lock); > + if (x != crc[page] && unused) { this is also always false and besides it needs to be included inside the locks. Thanks, Andi > pr_debug("unused stolen page %pa modified by GPU reset\n", > &page); > if (count++ == 0) > -- > 2.55.0 >