From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on gnuweeb.org X-Spam-Level: X-Spam-Status: No, score=-5.1 required=5.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_HI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 Authentication-Results: gnuweeb.org; dmarc=pass (p=none dis=none) header.from=kernel.org Authentication-Results: gnuweeb.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=LE1LcIYw; dkim-atps=neutral Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=139.178.84.217; helo=dfw.source.kernel.org; envelope-from=srs0=rfi9=ca=paulmck-thinkpad-p17-gen-1.home=paulmck@kernel.org; receiver= Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by gnuweeb.org (Postfix) with ESMTPS id 5855523EC25 for ; Tue, 13 Jun 2023 03:45:17 +0700 (WIB) 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 3B89D628AF; 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: 8bit List-Id: From: Thomas Weißschuh 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@p183/ Signed-off-by: Thomas Weißschuh 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/selftests/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; } -#if defined(__clang__) -__attribute__((optnone)) -#elif defined(__GNUC__) -__attribute__((optimize("O0"))) -#endif static int smash_stack(void) { char buf[100]; + volatile char *ptr = buf; for (size_t i = 0; i < 200; i++) - buf[i] = 'P'; + ptr[i] = 'P'; return 1; } -- 2.40.1