From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8D49326AFB; Tue, 13 Aug 2024 22:12:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723587146; cv=none; b=tsiD9R03OUoZ5m9RCRmJ5XdE6MIvI5OORlZ3EyXgHqzEz3PsFwhwWa1n7BtS9k534GISbkJwR18lKn8bh6+1eBmGHsQ5wYEAw90DfqbVeE+dJZxav6cHuoWIDVGBLF19EgHoG9RnOaFrlUGmqRTUmf8lzeCnUKv/9TSZ3oT/pA8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723587146; c=relaxed/simple; bh=nNhcw7GB8NcDgN2OIa/5pzlGkqY40T6fJOTJq7Kn/28=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=sE4mxUXbDucxoCV3FxIbBBC7yeDpClF8VbHv0ytxWhcjVl5NTEn9uUgVb3YSh67Ql7yI/VrhAA5guC0y2hmbSuTYZ58FLe9EyHSuLcdxKA4fNHWnexVkX8KXTA5tDd4JpwEbfU84YYiSu8KdKYe280aMQ2m2ZCsVDaCz/lXkISQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fhrM7kIN; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="fhrM7kIN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 701E6C32782; Tue, 13 Aug 2024 22:12:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1723587144; bh=nNhcw7GB8NcDgN2OIa/5pzlGkqY40T6fJOTJq7Kn/28=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=fhrM7kINDPMWXeggXL9i/Sehk6QeQkOlY6YuW3N0PCtlBBKKPIdacuVrDOiMpuc9R JzyV4H8XiE5h1T9b1SD6N6CiM+tRiKKT3e4rmNioBE5Qm2Bnv425bIBn3QxnpAOBsL sm+mUcJLQsA+XYULobmzec4iA5hB+F+6/VSADvIDq4DWPrGliU2+zf8pXIfovm1xhP X0cY2G+XPjBl0fMqkfYOnif8907g4bvwWg335XqYg1O2NM5mSod3aaFXtHk7hHmOGj gxLsC0ERARklGslq/Rc6ocX3dwA4dujazUkb9x4koaLeDd9GILrVoZnAVrKzonVUuK ioyfv7Jzerbyg== Date: Tue, 13 Aug 2024 15:12:21 -0700 From: Nathan Chancellor To: Yury Norov Cc: Alexander Lobakin , Kees Cook , Nick Desaulniers , oe-kbuild-all@lists.linux.dev, linux-kernel@vger.kernel.org, Przemek Kitszel , kernel test robot , llvm@lists.linux.dev, llvm-bugs@lists.llvm.org Subject: Re: lib/test_bitmap.c:1278:2: error: call to '__compiletime_assert_127' declared with 'error' attribute: BUILD_BUG_ON failed: !__builtin_constant_p(~var) Message-ID: <20240813221221.GA798176@thelio-3990X> References: <202408131601.Aj9JmK7K-lkp@intel.com> <2690861a-e726-4149-98ff-d26ec6d595ac@intel.com> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Aug 13, 2024 at 12:47:27PM -0700, Yury Norov wrote: > On Tue, Aug 13, 2024 at 04:38:10PM +0200, Alexander Lobakin wrote: > > From: Kernel Test Robot > > Date: Tue, 13 Aug 2024 17:00:56 +0800 > > > > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master > > > head: d74da846046aeec9333e802f5918bd3261fb5509 > > > commit: 7adaf37f7f104a7ee5f150af491674ccbbfc4114 lib/bitmap: add compile-time test for __assign_bit() optimization > > > date: 4 months ago > > > config: um-randconfig-r132-20240812 (https://download.01.org/0day-ci/archive/20240813/202408131601.Aj9JmK7K-lkp@intel.com/config) > > > compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project f86594788ce93b696675c94f54016d27a6c21d18) > > > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240813/202408131601.Aj9JmK7K-lkp@intel.com/reproduce) > > > > > > If you fix the issue in a separate patch/commit (i.e. not just a new version of > > > the same patch/commit), kindly add following tags > > > | Reported-by: kernel test robot > > > | Closes: https://lore.kernel.org/oe-kbuild-all/202408131601.Aj9JmK7K-lkp@intel.com/ > > > > > > All errors (new ones prefixed by >>): > > > > > >>> lib/test_bitmap.c:1278:2: error: call to '__compiletime_assert_127' declared with 'error' attribute: BUILD_BUG_ON failed: !__builtin_constant_p(~var) > > > 1278 | BUILD_BUG_ON(!__builtin_constant_p(~var)); > > > | ^ > > > include/linux/build_bug.h:50:2: note: expanded from macro 'BUILD_BUG_ON' > > > 50 | 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' > > > 39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) > > > | ^ > > > include/linux/compiler_types.h:460:2: note: expanded from macro 'compiletime_assert' > > > 460 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) > > > | ^ > > > include/linux/compiler_types.h:448:2: note: expanded from macro '_compiletime_assert' > > > 448 | __compiletime_assert(condition, msg, prefix, suffix) > > > | ^ > > > include/linux/compiler_types.h:441:4: note: expanded from macro '__compiletime_assert' > > > 441 | prefix ## suffix(); \ > > > | ^ > > > :193:1: note: expanded from here > > > 193 | __compiletime_assert_127 > > > | ^ > > > 1 error generated. > > > > > > > > > vim +1278 lib/test_bitmap.c > > > > > > 291f93ca339f5b Barry Song 2021-08-06 1227 > > > 2356d198d2b4dd Yury Norov 2023-07-17 1228 /* > > > 2356d198d2b4dd Yury Norov 2023-07-17 1229 * FIXME: Clang breaks compile-time evaluations when KASAN and GCOV are enabled. > > > 2356d198d2b4dd Yury Norov 2023-07-17 1230 * To workaround it, GCOV is force-disabled in Makefile for this configuration. > > > 2356d198d2b4dd Yury Norov 2023-07-17 1231 */ > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1232 static void __init test_bitmap_const_eval(void) > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1233 { > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1234 DECLARE_BITMAP(bitmap, BITS_PER_LONG); > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1235 unsigned long initvar = BIT(2); > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1236 unsigned long bitopvar = 0; > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1237 unsigned long var = 0; > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1238 int res; > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1239 > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1240 /* > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1241 * Compilers must be able to optimize all of those to compile-time > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1242 * constants on any supported optimization level (-O2, -Os) and any > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1243 * architecture. Otherwise, trigger a build bug. > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1244 * The whole function gets optimized out then, there's nothing to do > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1245 * in runtime. > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1246 */ > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1247 > > > 7adaf37f7f104a Alexander Lobakin 2024-03-27 1248 /* Equals to `unsigned long bitmap[1] = { GENMASK(6, 5), }` */ > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1249 bitmap_clear(bitmap, 0, BITS_PER_LONG); > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1250 if (!test_bit(7, bitmap)) > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1251 bitmap_set(bitmap, 5, 2); > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1252 > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1253 /* Equals to `unsigned long bitopvar = BIT(20)` */ > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1254 __change_bit(31, &bitopvar); > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1255 bitmap_shift_right(&bitopvar, &bitopvar, 11, BITS_PER_LONG); > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1256 > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1257 /* Equals to `unsigned long var = BIT(25)` */ > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1258 var |= BIT(25); > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1259 if (var & BIT(0)) > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1260 var ^= GENMASK(9, 6); > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1261 > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1262 /* __const_hweight<32|64>(GENMASK(6, 5)) == 2 */ > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1263 res = bitmap_weight(bitmap, 20); > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1264 BUILD_BUG_ON(!__builtin_constant_p(res)); > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1265 BUILD_BUG_ON(res != 2); > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1266 > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1267 /* !(BIT(31) & BIT(18)) == 1 */ > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1268 res = !test_bit(18, &bitopvar); > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1269 BUILD_BUG_ON(!__builtin_constant_p(res)); > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1270 BUILD_BUG_ON(!res); > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1271 > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1272 /* BIT(2) & GENMASK(14, 8) == 0 */ > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1273 res = initvar & GENMASK(14, 8); > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1274 BUILD_BUG_ON(!__builtin_constant_p(res)); > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1275 BUILD_BUG_ON(res); > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1276 > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1277 /* ~BIT(25) */ > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 @1278 BUILD_BUG_ON(!__builtin_constant_p(~var)); > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1279 BUILD_BUG_ON(~var != ~BIT(25)); > > > 7adaf37f7f104a Alexander Lobakin 2024-03-27 1280 > > > 7adaf37f7f104a Alexander Lobakin 2024-03-27 1281 /* ~BIT(25) | BIT(25) == ~0UL */ > > > 7adaf37f7f104a Alexander Lobakin 2024-03-27 1282 bitmap_complement(&var, &var, BITS_PER_LONG); > > > 7adaf37f7f104a Alexander Lobakin 2024-03-27 1283 __assign_bit(25, &var, true); > > > 7adaf37f7f104a Alexander Lobakin 2024-03-27 1284 > > > 7adaf37f7f104a Alexander Lobakin 2024-03-27 1285 /* !(~(~0UL)) == 1 */ > > > 7adaf37f7f104a Alexander Lobakin 2024-03-27 1286 res = bitmap_full(&var, BITS_PER_LONG); > > > 7adaf37f7f104a Alexander Lobakin 2024-03-27 1287 BUILD_BUG_ON(!__builtin_constant_p(res)); > > > 7adaf37f7f104a Alexander Lobakin 2024-03-27 1288 BUILD_BUG_ON(!res); > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1289 } > > > dc34d5036692c6 Alexander Lobakin 2022-06-24 1290 > > > > > > :::::: The code at line 1278 was first introduced by commit > > > :::::: dc34d5036692c614eef23c1130ee42a201c316bf lib: test_bitmap: add compile-time optimization/evaluations assertions > > > > > > :::::: TO: Alexander Lobakin > > > :::::: CC: Yury Norov > > > > + Cc Clang folks. > > > > clang-dev 20 issue? > > > > Thanks, > > Olek > > Seems like that. Looping LLVM-bugs . It's not, I bisected it to a change in the 17 release. I think this only shows up with this change because of '-fprofile-instr-generate', which ARCH=um uses for GCOV, which was only added in commit 32a84cfc6caf ("arch: um: Add Clang coverage support") from 6.8. I reported this upstream (I don't think llvm-bugs is really monitored for traffic like this) and cc'd the author of the change that broke this: https://github.com/llvm/llvm-project/issues/103479 I think there is a tangential issue with ARCH=um doing its own thing with the GCOV flags (such that it does not appear to respect GCOV_PROFILE_... := n) but that just results in not being able to remove the flags from test_bitmap.o's command. Cheers, Nathan