From nobody Fri Sep 12 00:24:01 2025 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 BBB85C636CC for ; Wed, 15 Feb 2023 13:01:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234002AbjBONBc (ORCPT ); Wed, 15 Feb 2023 08:01:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46148 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233786AbjBONB1 (ORCPT ); Wed, 15 Feb 2023 08:01:27 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0854431E33 for ; Wed, 15 Feb 2023 05:01:26 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A7164B821C4 for ; Wed, 15 Feb 2023 13:01:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4813DC433EF; Wed, 15 Feb 2023 13:01:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1676466083; bh=LCrzUXqbVxh67TyCMfdqY6tY7QeA2lgRgFNm/o1Clp0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=trjIqlwZyO+lwC6wY2BwIi2/mShc9WUDm9YrsjZ24D2fsCN/XdBERQW+gmteC8VNN YK4uldLchrzIGLzJ3nz93yG0XY7arZ3i4YgZ2Lc9Mu9lA7KxV1k4dey5CH+NCH8XPe T12gdgRSJvbK/HMFSkuKhQgI07jjONQ6YMov3TAIPRXlQM0Xh0TamEqo1+hkqCwWit A/HGHQ8tTFEqzT5Y7HhQ4ZkU+ePlRphqBw0io5rRVIm9/ye4Ja+OE3AAvycLdCH3OP m22aM8Hqp22iEmk+ci6F6qJRnjS2DdmigNWX2mZU7KKQzMWrXtKyApa/5ozRNmPlry yABFYRztl4azg== From: Arnd Bergmann To: Andrew Morton , Josh Poimboeuf , Peter Zijlstra Cc: Arnd Bergmann , Alexander Potapenko , Andrey Konovalov , Andrey Ryabinin , Dmitry Vyukov , Kuan-Ying Lee , Marco Elver , Vincenzo Frascino , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/3] [v2] objtool: add UACCESS exceptions for __tsan_volatile_read/write Date: Wed, 15 Feb 2023 14:00:58 +0100 Message-Id: <20230215130058.3836177-4-arnd@kernel.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230215130058.3836177-1-arnd@kernel.org> References: <20230215130058.3836177-1-arnd@kernel.org> 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" From: Arnd Bergmann A lot of the tsan helpers are already excempt from the UACCESS warnings, but some more functions were added that need the same thing: kernel/kcsan/core.o: warning: objtool: __tsan_volatile_read16+0x0: call to = __tsan_unaligned_read16() with UACCESS enabled kernel/kcsan/core.o: warning: objtool: __tsan_volatile_write16+0x0: call to= __tsan_unaligned_write16() with UACCESS enabled vmlinux.o: warning: objtool: __tsan_unaligned_volatile_read16+0x4: call to = __tsan_unaligned_read16() with UACCESS enabled vmlinux.o: warning: objtool: __tsan_unaligned_volatile_write16+0x4: call to= __tsan_unaligned_write16() with UACCESS enabled As Marco points out, these functions don't even call each other explicitly but instead gcc (but not clang) notices the functions being identical and turns one symbol into a direct branch to the other. Fixes: 75d75b7a4d54 ("kcsan: Support distinguishing volatile accesses") Acked-by: Marco Elver Signed-off-by: Arnd Bergmann --- tools/objtool/check.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index b0b467d9608a..da52ce861cc2 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -1237,6 +1237,8 @@ static const char *uaccess_safe_builtin[] =3D { "__tsan_atomic64_compare_exchange_val", "__tsan_atomic_thread_fence", "__tsan_atomic_signal_fence", + "__tsan_unaligned_read16", + "__tsan_unaligned_write16", /* KCOV */ "write_comp_data", "check_kcov_mode", --=20 2.39.1