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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham 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 0FF8AC11D00 for ; Thu, 20 Feb 2020 23:22:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DEC9220801 for ; Thu, 20 Feb 2020 23:22:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729376AbgBTXWZ (ORCPT ); Thu, 20 Feb 2020 18:22:25 -0500 Received: from mga06.intel.com ([134.134.136.31]:29032 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729330AbgBTXWW (ORCPT ); Thu, 20 Feb 2020 18:22:22 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Feb 2020 15:22:20 -0800 X-IronPort-AV: E=Sophos;i="5.70,466,1574150400"; d="scan'208";a="225026470" Received: from jbrandeb-desk.jf.intel.com ([10.166.244.152]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Feb 2020 15:22:20 -0800 From: Jesse Brandeburg To: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de Cc: Jesse Brandeburg , x86@kernel.org, linux-kernel@vger.kernel.org, linux@rasmusvillemoes.dk, andriy.shevchenko@intel.com, dan.j.williams@intel.com, peterz@infradead.org Subject: [PATCH v3 2/2] lib: make a test module with set/clear bit Date: Thu, 20 Feb 2020 15:21:55 -0800 Message-Id: <20200220232155.2123827-2-jesse.brandeburg@intel.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200220232155.2123827-1-jesse.brandeburg@intel.com> References: <20200220232155.2123827-1-jesse.brandeburg@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Test some bit clears/sets to make sure assembly doesn't change, and that the set_bit and clear_bit functions work and don't cause sparse warnings. Instruct Kbuild to build this file with extra warning level -Wextra, to catch new issues, and also doesn't hurt to build with C=1. This was used to test changes to arch/x86/include/asm/bitops.h. In particular, sparse (C=1) was very concerned when the last bit before a natural boundary, like 7, or 31, was being tested, as this causes sign extension (0xffffff7f) for instance when clearing bit 7. Recommended usage: make defconfig scripts/config -m CONFIG_TEST_BITOPS make modules_prepare make C=1 W=1 lib/test_bitops.ko objdump -S -d lib/test_bitops.ko Signed-off-by: Jesse Brandeburg --- v3: update the test to fail if bits aren't cleared, and make the test reproduce the original issue without patch 1/2, showing that the issue is fixed in patch 1/2. Thanks PeterZ! v2: correct CC: list --- lib/Kconfig.debug | 13 +++++++ lib/Makefile | 2 ++ lib/test_bitops.c | 55 ++++++++++++++++++++++++++++++ tools/testing/selftests/lib/config | 1 + 4 files changed, 71 insertions(+) create mode 100644 lib/test_bitops.c diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 69def4a9df00..61a5d00ea064 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1947,6 +1947,19 @@ config TEST_LKM If unsure, say N. +config TEST_BITOPS + tristate "Test module for compilation of clear_bit/set_bit operations" + depends on m + help + This builds the "test_bitops" module that is much like the + TEST_LKM module except that it does a basic exercise of the + clear_bit and set_bit macros to make sure there are no compiler + warnings from C=1 sparse checker or -Wextra compilations. It has + no dependencies and doesn't run or load unless explicitly requested + by name. for example: modprobe test_bitops. + + If unsure, say N. + config TEST_VMALLOC tristate "Test module for stress/performance analysis of vmalloc allocator" default n diff --git a/lib/Makefile b/lib/Makefile index 611872c06926..b18db565b355 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -89,6 +89,8 @@ obj-$(CONFIG_TEST_OBJAGG) += test_objagg.o obj-$(CONFIG_TEST_STACKINIT) += test_stackinit.o obj-$(CONFIG_TEST_BLACKHOLE_DEV) += test_blackhole_dev.o obj-$(CONFIG_TEST_MEMINIT) += test_meminit.o +obj-$(CONFIG_TEST_BITOPS) += test_bitops.o +CFLAGS_test_bitops.o += -Werror obj-$(CONFIG_TEST_LIVEPATCH) += livepatch/ diff --git a/lib/test_bitops.c b/lib/test_bitops.c new file mode 100644 index 000000000000..97339d6455b0 --- /dev/null +++ b/lib/test_bitops.c @@ -0,0 +1,55 @@ +// SPDX-License-Identifier: GPL-2.0-only +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include + +/* a tiny module only meant to compile-test set/clear_bit */ + +/* use an enum because thats the most common BITMAP usage */ +enum bitops_fun { + BITOPS_4 = 4, + BITOPS_7 = 7, + BITOPS_11 = 11, + BITOPS_31 = 31, + BITOPS_88 = 88, + BITOPS_LAST = 255 +}; + +static DECLARE_BITMAP(g_bitmap, BITOPS_LAST); + +static int __init test_bitops_startup(void) +{ + pr_warn("Loaded test module\n"); + set_bit(BITOPS_4, g_bitmap); + set_bit(BITOPS_7, g_bitmap); + set_bit(BITOPS_11, g_bitmap); + set_bit(BITOPS_31, g_bitmap); + set_bit(BITOPS_88, g_bitmap); + return 0; +} + +static void __exit test_bitops_unstartup(void) +{ + int bit_set; + + clear_bit(BITOPS_4, g_bitmap); + clear_bit(BITOPS_7, g_bitmap); + clear_bit(BITOPS_11, g_bitmap); + clear_bit(BITOPS_31, g_bitmap); + clear_bit(BITOPS_88, g_bitmap); + + bit_set = find_first_bit(g_bitmap, BITOPS_LAST); + if (bit_set != BITOPS_LAST) + pr_err("ERROR: FOUND SET BIT %d\n", bit_set); + + pr_warn("Unloaded test module\n"); +} + +module_init(test_bitops_startup); +module_exit(test_bitops_unstartup); + +MODULE_AUTHOR("Jesse Brandeburg "); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Bit testing module"); diff --git a/tools/testing/selftests/lib/config b/tools/testing/selftests/lib/config index 14a77ea4a8da..b80ee3f6e265 100644 --- a/tools/testing/selftests/lib/config +++ b/tools/testing/selftests/lib/config @@ -2,3 +2,4 @@ CONFIG_TEST_PRINTF=m CONFIG_TEST_BITMAP=m CONFIG_PRIME_NUMBERS=m CONFIG_TEST_STRSCPY=m +CONFIG_TEST_BITOPS=m -- 2.24.1