From nobody Mon Feb 9 11:48:00 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 EFF55C7EE43 for ; Mon, 12 Jun 2023 20:47:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236841AbjFLUr2 (ORCPT ); Mon, 12 Jun 2023 16:47:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35820 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232473AbjFLUqv (ORCPT ); Mon, 12 Jun 2023 16:46:51 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C8281BE8 for ; Mon, 12 Jun 2023 13:46:24 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 9C60C62953 for ; Mon, 12 Jun 2023 20:45:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0B93CC433EF; Mon, 12 Jun 2023 20:45:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686602716; bh=zEjOj9DdUomfDLsrKXBstSrS7dzFFqc89ym3/GOXT1g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LE1LcIYwMJvI71eAa4GoeB4kWpGGfgWaTbiAYVXU0qUoCLzO5MmgqhfKK7P2GCkGC btl1nZaTARSST2jONdpLc4gyzl0eUp+GU+Bs6A04MhrE11HlApUNBKRYiCiH0J+etB dQ6SYNKsnA/8IKz+AsgVaDo8/NHDJqe5B1M7PVoW/xyA23SZ50QvTlDxbl1a5R+nCa YSOluy0GD5XhknNvzSU9rzNX0ydf4jSe/qv0wjeeDRXD8EtZzbjcZTlZbhFBLqOOJQ 1xfrhDRt/REVx1PmbXambLE7+1qCS9RI0uJmi3FYgVK0BgERrdYSqcmZtxwJrD3HO/ lvsDqhtAqjGtw== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id AA609CE09E7; Mon, 12 Jun 2023 13:45:15 -0700 (PDT) From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: gwml@vger.gnuweeb.org, kernel-team@meta.com, w@lwt.eu, =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= , Alexey Dobriyan , Willy Tarreau , "Paul E . McKenney" Subject: [PATCH v2 nolibc 01/53] tools/nolibc: tests: use volatile to force stack smashing Date: Mon, 12 Jun 2023 13:44:22 -0700 Message-Id: <20230612204514.292087-1-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <8b757cc0-3719-4e63-a755-9710384137bc@paulmck-laptop> References: <8b757cc0-3719-4e63-a755-9710384137bc@paulmck-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Thomas Wei=C3=9Fschuh Use a volatile pointer to write outside the buffer so the compiler can't optimize it away. Reported-by: Alexey Dobriyan Link: https://lore.kernel.org/lkml/c0584807-511c-4496-b062-1263ea38f349@p18= 3/ Signed-off-by: Thomas Wei=C3=9Fschuh Signed-off-by: Willy Tarreau Signed-off-by: Paul E. McKenney --- tools/testing/selftests/nolibc/nolibc-test.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/s= elftests/nolibc/nolibc-test.c index 21bacc928bf7..47013b78972e 100644 --- a/tools/testing/selftests/nolibc/nolibc-test.c +++ b/tools/testing/selftests/nolibc/nolibc-test.c @@ -667,17 +667,13 @@ int run_stdlib(int min, int max) return ret; } =20 -#if defined(__clang__) -__attribute__((optnone)) -#elif defined(__GNUC__) -__attribute__((optimize("O0"))) -#endif static int smash_stack(void) { char buf[100]; + volatile char *ptr =3D buf; =20 for (size_t i =3D 0; i < 200; i++) - buf[i] =3D 'P'; + ptr[i] =3D 'P'; =20 return 1; } --=20 2.40.1