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 X-Spam-Level: X-Spam-Status: No, score=-9.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,URIBL_SBL,URIBL_SBL_A,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3B37BC7618B for ; Fri, 26 Jul 2019 13:43:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 084AB22CD8 for ; Fri, 26 Jul 2019 13:43:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564148595; bh=YfDo/63lxPW0sH2O9DcR7uvSG7t0vwBN3OKd1Ls/sr8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=xN51K5AiyCEghrOWfE2C090keNGhFSXwbVzpF7FdbvJEwnyRsxYkaOBSbyPps5xqw UzphkoZSJp8XEdPi9ORC8gMRpIsD+Cc0HsDE5FSgTOuXciKCJC5dSETk+TwZ2MljwT CHZBy2jr8gEMK6/0ZCLYWsc+y0/At+h2lzLB1c9Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388151AbfGZNnN (ORCPT ); Fri, 26 Jul 2019 09:43:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:50582 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388130AbfGZNnG (ORCPT ); Fri, 26 Jul 2019 09:43:06 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2A4A822BF5; Fri, 26 Jul 2019 13:43:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564148585; bh=YfDo/63lxPW0sH2O9DcR7uvSG7t0vwBN3OKd1Ls/sr8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kOjKPC2cNvhvr1IU9Gp8xDqln9D4XZzzRS9W61dYioa0PTpYu4zJgg04TS24pTD/p nvKKZ6141Yh5BG7D5wSheIKDlaujnKbmbj5FMwfdmvrmfg6e4hriU/SQ+59PxPne39 FyB73b9zt+yLyuREzsIL+8zDa81irleL1fl76K9Q= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Peter Rosin , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH AUTOSEL 4.19 32/47] lib/test_string.c: avoid masking memset16/32/64 failures Date: Fri, 26 Jul 2019 09:41:55 -0400 Message-Id: <20190726134210.12156-32-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190726134210.12156-1-sashal@kernel.org> References: <20190726134210.12156-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peter Rosin [ Upstream commit 33d6e0ff68af74be0c846c8e042e84a9a1a0561e ] If a memsetXX implementation is completely broken and fails in the first iteration, when i, j, and k are all zero, the failure is masked as zero is returned. Failing in the first iteration is perhaps the most likely failure, so this makes the tests pretty much useless. Avoid the situation by always setting a random unused bit in the result on failure. Link: http://lkml.kernel.org/r/20190506124634.6807-3-peda@axentia.se Fixes: 03270c13c5ff ("lib/string.c: add testcases for memset16/32/64") Signed-off-by: Peter Rosin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- lib/test_string.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/lib/test_string.c b/lib/test_string.c index 0fcdb82dca86..98a787e7a1fd 100644 --- a/lib/test_string.c +++ b/lib/test_string.c @@ -35,7 +35,7 @@ static __init int memset16_selftest(void) fail: kfree(p); if (i < 256) - return (i << 24) | (j << 16) | k; + return (i << 24) | (j << 16) | k | 0x8000; return 0; } @@ -71,7 +71,7 @@ static __init int memset32_selftest(void) fail: kfree(p); if (i < 256) - return (i << 24) | (j << 16) | k; + return (i << 24) | (j << 16) | k | 0x8000; return 0; } @@ -107,7 +107,7 @@ static __init int memset64_selftest(void) fail: kfree(p); if (i < 256) - return (i << 24) | (j << 16) | k; + return (i << 24) | (j << 16) | k | 0x8000; return 0; } -- 2.20.1