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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 167E7C77B72 for ; Thu, 6 Apr 2023 11:34:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238115AbjDFLeG (ORCPT ); Thu, 6 Apr 2023 07:34:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34790 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237944AbjDFLdY (ORCPT ); Thu, 6 Apr 2023 07:33:24 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 06E78A5CF; Thu, 6 Apr 2023 04:32:43 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C965A64478; Thu, 6 Apr 2023 11:32:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D823CC433D2; Thu, 6 Apr 2023 11:32:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1680780762; bh=gbj4RU+WH+JTTi3fle7TPFkxkVd8ZbwYZhG3W2bu5jA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RlNVFakRtZKVNWmlanKuFie5Mn/aBlxHtRNvZNY8FnNzpxZq6GdkykaxKuglZZSk5 MbttfqVoAP/gLubGKJ+rw63uBKuK4E8Rsy7ka20Y77lQJ9qE3ZoxHdi6b54ZhDvDgK R2lch/+bl0uF+IaAwb0zJVnltme/DeCSWrR6QvqpFoNai4xxrw/AzuFxTGarLjI39X d74fGpYew6F3Q9AoRPMH91ddrMy65Nt6nMCMkbVqd9Fx18+8VUbejzxo9b4cFYEWfw ein/AfgoKbBc3/vC+5J9TJleaBz8/dolWRdZr9HEd701W4yJRUqRD7f7Kp4D1hg0WN ECUU7Ve0Bg/Yg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: David Gow , =?UTF-8?q?Christian=20K=C3=B6nig?= , =?UTF-8?q?Ma=C3=ADra=20Canal?= , Arunpravin Paneer Selvam , Sasha Levin , airlied@gmail.com, daniel@ffwll.ch, mairacanal@riseup.net, javierm@redhat.com, djwong@kernel.org, arthurgrillo@riseup.net, Jason@zx2c4.com, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 6.1 12/17] drm: test: Fix 32-bit issue in drm_buddy_test Date: Thu, 6 Apr 2023 07:32:06 -0400 Message-Id: <20230406113211.648424-12-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230406113211.648424-1-sashal@kernel.org> References: <20230406113211.648424-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: David Gow [ Upstream commit 25bbe844ef5c4fb4d7d8dcaa0080f922b7cd3a16 ] The drm_buddy_test KUnit tests verify that returned blocks have sizes which are powers of two using is_power_of_2(). However, is_power_of_2() operations on a 'long', but the block size is a u64. So on systems where long is 32-bit, this can sometimes fail even on correctly sized blocks. This only reproduces randomly, as the parameters passed to the buddy allocator in this test are random. The seed 0xb2e06022 reproduced it fine here. For now, just hardcode an is_power_of_2() implementation using x & (x - 1). Signed-off-by: David Gow Acked-by: Christian König Reviewed-by: Maíra Canal Reviewed-by: Arunpravin Paneer Selvam Link: https://patchwork.freedesktop.org/patch/msgid/20230329065532.2122295-2-davidgow@google.com Signed-off-by: Christian König Signed-off-by: Sasha Levin --- drivers/gpu/drm/tests/drm_buddy_test.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/tests/drm_buddy_test.c b/drivers/gpu/drm/tests/drm_buddy_test.c index 62f69589a72d3..a699fc0dc8579 100644 --- a/drivers/gpu/drm/tests/drm_buddy_test.c +++ b/drivers/gpu/drm/tests/drm_buddy_test.c @@ -89,7 +89,8 @@ static int check_block(struct kunit *test, struct drm_buddy *mm, err = -EINVAL; } - if (!is_power_of_2(block_size)) { + /* We can't use is_power_of_2() for a u64 on 32-bit systems. */ + if (block_size & (block_size - 1)) { kunit_err(test, "block size not power of two\n"); err = -EINVAL; } -- 2.39.2