From nobody Sun Feb 8 00:34:40 2026 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 519D1EB64DC for ; Mon, 17 Jul 2023 19:58:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230136AbjGQT6z (ORCPT ); Mon, 17 Jul 2023 15:58:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49894 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229844AbjGQT6s (ORCPT ); Mon, 17 Jul 2023 15:58:48 -0400 Received: from mail-pf1-x42d.google.com (mail-pf1-x42d.google.com [IPv6:2607:f8b0:4864:20::42d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9960F136 for ; Mon, 17 Jul 2023 12:58:44 -0700 (PDT) Received: by mail-pf1-x42d.google.com with SMTP id d2e1a72fcca58-668709767b1so3568071b3a.2 for ; Mon, 17 Jul 2023 12:58:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1689623924; x=1692215924; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=rR/WXoMTQWpIUYil39t/+gnlISlq3LT4l8C56BzZmtA=; b=C9A5FyWyJdLMLcgM2nbvMhNVoYyvZsdYr3itLtwGmaidb2E+4aBz/cmsAH33eoyHHm HCpvp/J4RfFDFCtWouqvg1amXx83YA2jxeygypGCjGqAdDJQoWSg1o0iteaJhXtvF84u 8LSOvuq1XeK7ByQO2HqaeNflruX/YGmWqgRAd6Gxng5vyPTZVK/6WcGmOBvWakftPVmg 1EmdFzrKJuMdpztu4WZICYFzgPU4rq0+fV1Tp+0lHEr5oTCL7ZWi3Wh3rQHGAE0Dpy4k 1SmEf1H363eCXej7FKrpIGgv+y7x4oAgCmP0iiEd2Jce5WIQI2xfFeG9amR6qCc9lUC1 R2Zg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689623924; x=1692215924; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=rR/WXoMTQWpIUYil39t/+gnlISlq3LT4l8C56BzZmtA=; b=Hu7TWsWqwbEEPZP5b0ZnzZJl3BH/Qb3xlPdx8pA3tzrLIWyFuH6a31o31M42jHM0QH k68Gm8f530NjIRDfaOxo/RKEjB5AXT4s94RNg8uGP184AffYMi3Hc3y3z8DbLatclB2z v2XvWUQpCULl9ShyixXZPr2HfKRruOd5uIWBHG1wyvvbEsxVBT3vQzUii9Qzdf+gUb2a QOM+X/8/PdR/93K9vKYNWpiFORwf9ZFoZj+76QgsKwu4axIR9oYUUhKbt+ZGwwYKkn3v MYo5wmFck8FmltP4rLCBBhVkMXpsT5yZhVjFaxO1a3nGjawzn0WdBOl5E3S2YZb4tEjr sjpA== X-Gm-Message-State: ABy/qLZkheflaYEqJ5+H/CW0VxWM6vJHLUTaV6J0bQatMLgQkSEl4dP7 4fMUI2gsBRXESgIO89uUREDb3CmyGe/Bjw== X-Google-Smtp-Source: APBJJlFMy4/IrDNwje1azicy2QD5va5DF5szxQAAc7YOt0kfRukNidF+lJUKk5yNJi+cT6gcfNjVRQ== X-Received: by 2002:a05:6a20:3c8c:b0:133:cf5c:4d2e with SMTP id b12-20020a056a203c8c00b00133cf5c4d2emr621393pzj.20.1689623923509; Mon, 17 Jul 2023 12:58:43 -0700 (PDT) Received: from localhost ([216.228.127.128]) by smtp.gmail.com with ESMTPSA id e21-20020a170902d39500b001ac2be26340sm246556pld.222.2023.07.17.12.58.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 17 Jul 2023 12:58:43 -0700 (PDT) From: Yury Norov To: linux-kernel@vger.kernel.org, llvm@lists.linux.dev, Nick Desaulniers Cc: Yury Norov , Andy Shevchenko , Alexander Lobakin , Maxim Kuvyrkov , Rasmus Villemoes , Nathan Chancellor , Tom Rix , oe-kbuild-all@lists.linux.dev Subject: [PATCH] lib/bitmap: waive const_eval test as it breaks the build Date: Mon, 17 Jul 2023 12:58:13 -0700 Message-Id: <20230717195813.29059-1-yury.norov@gmail.com> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" When building with clang, and when KASAN and GCOV_PROFILE_ALL are both enabled, the test fails to build [1]: >> lib/test_bitmap.c:920:2: error: call to '__compiletime_assert_239' decla= red with 'error' attribute: BUILD_BUG_ON failed: !__builtin_constant_p(res) BUILD_BUG_ON(!__builtin_constant_p(res)); ^ include/linux/build_bug.h:50:2: note: expanded from macro 'BUILD_BUG_ON' BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition) ^ include/linux/build_bug.h:39:37: note: expanded from macro 'BUILD_BUG_ON= _MSG' #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) ^ include/linux/compiler_types.h:352:2: note: expanded from macro 'compile= time_assert' _compiletime_assert(condition, msg, __compiletime_assert_, __COU= NTER__) ^ include/linux/compiler_types.h:340:2: note: expanded from macro '_compil= etime_assert' __compiletime_assert(condition, msg, prefix, suffix) ^ include/linux/compiler_types.h:333:4: note: expanded from macro '__compi= letime_assert' prefix ## suffix(); \ ^ :185:1: note: expanded from here __compiletime_assert_239 Originally it was attributed to s390, which now looks seemingly wrong. The issue is also not related to bitmap code itself, but it breaks build for a given configuration. So, disabling the test unless the compiler will get fixed. [1] https://github.com/ClangBuiltLinux/linux/issues/1874 Fixes: dc34d5036692 ("lib: test_bitmap: add compile-time optimization/evalu= ations assertions") Signed-off-by: Yury Norov --- lib/test_bitmap.c | 17 +++++------------ 1 file changed, 5 insertions(+), 12 deletions(-) diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c index 187f5b2db4cf..a791fdb7a8c9 100644 --- a/lib/test_bitmap.c +++ b/lib/test_bitmap.c @@ -1163,6 +1163,9 @@ static void __init test_bitmap_print_buf(void) =20 static void __init test_bitmap_const_eval(void) { +#if defined(CONFIG_CC_IS_CLANG) && defined(CONFIG_KASAN) && defined(CONFIG= _GCOV_PROFILE_ALL) +#warning "FIXME: Clang breaks compile time evaluations when KASAN and GCOV= are enabled" +#else DECLARE_BITMAP(bitmap, BITS_PER_LONG); unsigned long initvar =3D BIT(2); unsigned long bitopvar =3D 0; @@ -1177,20 +1180,9 @@ static void __init test_bitmap_const_eval(void) * in runtime. */ =20 - /* - * Equals to `unsigned long bitmap[1] =3D { GENMASK(6, 5), }`. - * Clang on s390 optimizes bitops at compile-time as intended, but at - * the same time stops treating @bitmap and @bitopvar as compile-time - * constants after regular test_bit() is executed, thus triggering the - * build bugs below. So, call const_test_bit() there directly until - * the compiler is fixed. - */ + /* Equals to `unsigned long bitmap[1] =3D { GENMASK(6, 5), }` */ bitmap_clear(bitmap, 0, BITS_PER_LONG); -#if defined(__s390__) && defined(__clang__) - if (!const_test_bit(7, bitmap)) -#else if (!test_bit(7, bitmap)) -#endif bitmap_set(bitmap, 5, 2); =20 /* Equals to `unsigned long bitopvar =3D BIT(20)` */ @@ -1220,6 +1212,7 @@ static void __init test_bitmap_const_eval(void) /* ~BIT(25) */ BUILD_BUG_ON(!__builtin_constant_p(~var)); BUILD_BUG_ON(~var !=3D ~BIT(25)); +#endif } =20 static void __init selftest(void) --=20 2.39.2