From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f172.google.com (mail-pf1-f172.google.com [209.85.210.172]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 79682C2CE; Mon, 17 Jul 2023 19:58:44 +0000 (UTC) Received: by mail-pf1-f172.google.com with SMTP id d2e1a72fcca58-6686a05bc66so3567622b3a.1; 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=U50dj3TwkieSlNYe7wh2X1bE3iYLDkUOrP2vosGQSZD7nnclCrFdGELW1fxGP/FOuw sJicM1a8qCP4VOc8Y1y0RU7l6oNsYltwqyFRqWyJxucfrRKW8xMZGDvSkXzYvF7/1Gph OBhO6Xq+c3C8fME5vYH5zgAHifnD32qaj2J7jctpuX8zCW5qoPTZZSkkrvGdAzFyZSIZ cneMMZ/HJqx9j2wv9gAvNKbYFdhPylBgnUH1h0M1FdTsaLGNdNyh9C76VmvEFs5SjKbo /yZCb144a4ximrzXekprl1PNnKibYj+RCzXHagEDJVPNvYO2xAYcPhznxDC1Q7r1+TL6 MFqw== X-Gm-Message-State: ABy/qLZFSehPzVBzQzsiwrjdncrvNAFB5Xje5xclOnoBmB9ZuZRhEKkc YdblHgPg9GJMGlqQtMn7Ou4= 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 Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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' declared 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 'compiletime_assert' _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) ^ include/linux/compiler_types.h:340:2: note: expanded from macro '_compiletime_assert' __compiletime_assert(condition, msg, prefix, suffix) ^ include/linux/compiler_types.h:333:4: note: expanded from macro '__compiletime_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/evaluations 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) 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 = BIT(2); unsigned long bitopvar = 0; @@ -1177,20 +1180,9 @@ static void __init test_bitmap_const_eval(void) * in runtime. */ - /* - * Equals to `unsigned long bitmap[1] = { 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] = { 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); /* Equals to `unsigned long bitopvar = 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 != ~BIT(25)); +#endif } static void __init selftest(void) -- 2.39.2