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 50FA1C7618E for ; Mon, 24 Apr 2023 13:25:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232183AbjDXNZy (ORCPT ); Mon, 24 Apr 2023 09:25:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52450 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232145AbjDXNZx (ORCPT ); Mon, 24 Apr 2023 09:25:53 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4F3535BBD for ; Mon, 24 Apr 2023 06:25:52 -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 DF1A3622B7 for ; Mon, 24 Apr 2023 13:25:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EEE00C433D2; Mon, 24 Apr 2023 13:25:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1682342751; bh=gbj4RU+WH+JTTi3fle7TPFkxkVd8ZbwYZhG3W2bu5jA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pp6u+sokPd9Ih7wSRsQn+D57qhbl/RWTRulDSjknmDjXjy+jZPAQFlD0ABW8UjjIf uLC6S2sEInUhAZOfnhDSMlIyGhVX7YlvIFZ6X+/VoxTbI95jBYvB9FkaiBaewrBaE9 PNQfiaoMYbTwTHr9pDDA57GgNRfhWyGEfu/a/QZQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, David Gow , =?UTF-8?q?Christian=20K=C3=B6nig?= , =?UTF-8?q?Ma=C3=ADra=20Canal?= , Arunpravin Paneer Selvam , Sasha Levin Subject: [PATCH 6.1 43/98] drm: test: Fix 32-bit issue in drm_buddy_test Date: Mon, 24 Apr 2023 15:17:06 +0200 Message-Id: <20230424131135.544041465@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230424131133.829259077@linuxfoundation.org> References: <20230424131133.829259077@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@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