From patchwork Sun Oct 17 12:38:22 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 12564205 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3C603C433F5 for ; Sun, 17 Oct 2021 12:39:17 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E058760F36 for ; Sun, 17 Oct 2021 12:39:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org E058760F36 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=csgroup.eu Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 717716B0073; Sun, 17 Oct 2021 08:39:16 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6C7696B0074; Sun, 17 Oct 2021 08:39:16 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5680C900002; Sun, 17 Oct 2021 08:39:16 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0125.hostedemail.com [216.40.44.125]) by kanga.kvack.org (Postfix) with ESMTP id 48A146B0073 for ; Sun, 17 Oct 2021 08:39:16 -0400 (EDT) Received: from smtpin38.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id F151F180AD81A for ; Sun, 17 Oct 2021 12:39:15 +0000 (UTC) X-FDA: 78705884670.38.D7AD80C Received: from pegase2.c-s.fr (pegase2.c-s.fr [93.17.235.10]) by imf04.hostedemail.com (Postfix) with ESMTP id DCF6D50000B4 for ; Sun, 17 Oct 2021 12:39:13 +0000 (UTC) Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4HXKM11gWJz9sSt; Sun, 17 Oct 2021 14:39:09 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase2.c-s.fr ([172.26.127.65]) by localhost (pegase2.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id SMYjPKjGtC6s; Sun, 17 Oct 2021 14:39:09 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase2.c-s.fr (Postfix) with ESMTP id 4HXKLz6ZWqz9sSf; Sun, 17 Oct 2021 14:39:07 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id C9E668B76C; Sun, 17 Oct 2021 14:39:07 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id 4TN_i876SSxm; Sun, 17 Oct 2021 14:39:07 +0200 (CEST) Received: from PO20335.IDSI0.si.c-s.fr (unknown [192.168.203.38]) by messagerie.si.c-s.fr (Postfix) with ESMTP id C62568B773; Sun, 17 Oct 2021 14:39:06 +0200 (CEST) Received: from PO20335.IDSI0.si.c-s.fr (localhost [127.0.0.1]) by PO20335.IDSI0.si.c-s.fr (8.16.1/8.16.1) with ESMTPS id 19HCcugL2946765 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Sun, 17 Oct 2021 14:38:56 +0200 Received: (from chleroy@localhost) by PO20335.IDSI0.si.c-s.fr (8.16.1/8.16.1/Submit) id 19HCcunV2946764; Sun, 17 Oct 2021 14:38:56 +0200 X-Authentication-Warning: PO20335.IDSI0.si.c-s.fr: chleroy set sender to christophe.leroy@csgroup.eu using -f From: Christophe Leroy To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Andrew Morton , "James E.J. Bottomley" , Helge Deller , Arnd Bergmann , Kees Cook , Greg Kroah-Hartman Cc: Christophe Leroy , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-ia64@vger.kernel.org, linux-parisc@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v3 09/12] lkdtm: Force do_nothing() out of line Date: Sun, 17 Oct 2021 14:38:22 +0200 Message-Id: X-Mailer: git-send-email 2.31.1 In-Reply-To: References: MIME-Version: 1.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1634474303; l=1269; s=20211009; h=from:subject:message-id; bh=nSN/ioO339qfxQaSJCJwz7QKogrcJ3f1Q+xuI0OSdUc=; b=sCrxbtxbBdfHhd/haIYDYBas/MSiSTksFFeVvm9lJzxKhfTqzoZ/VjxacZGgBbQrQZvazP2UCOfF S4UNCePRCervGfGfrQA52l5dOI3WJAh2pGnG4EIl6xfjZ3HDXx15 X-Developer-Key: i=christophe.leroy@csgroup.eu; a=ed25519; pk=HIzTzUj91asvincQGOFx6+ZF5AoUuP9GdOtQChs7Mm0= X-Rspamd-Queue-Id: DCF6D50000B4 Authentication-Results: imf04.hostedemail.com; dkim=none; spf=pass (imf04.hostedemail.com: domain of christophe.leroy@csgroup.eu designates 93.17.235.10 as permitted sender) smtp.mailfrom=christophe.leroy@csgroup.eu; dmarc=none X-Stat-Signature: df4chq56wdua6gmm5rxkycmxpoomzmy3 X-Rspamd-Server: rspam05 X-HE-Tag: 1634474353-243610 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: LKDTM tests display that the run do_nothing() at a given address, but in reality do_nothing() is inlined into the caller. Force it out of line so that it really runs text at the displayed address. Acked-by: Kees Cook Signed-off-by: Christophe Leroy --- drivers/misc/lkdtm/perms.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c index 2dede2ef658f..60b3b2fe929d 100644 --- a/drivers/misc/lkdtm/perms.c +++ b/drivers/misc/lkdtm/perms.c @@ -21,7 +21,7 @@ /* This is non-const, so it will end up in the .data section. */ static u8 data_area[EXEC_SIZE]; -/* This is cost, so it will end up in the .rodata section. */ +/* This is const, so it will end up in the .rodata section. */ static const unsigned long rodata = 0xAA55AA55; /* This is marked __ro_after_init, so it should ultimately be .rodata. */ @@ -31,7 +31,7 @@ static unsigned long ro_after_init __ro_after_init = 0x55AA5500; * This just returns to the caller. It is designed to be copied into * non-executable memory regions. */ -static void do_nothing(void) +static noinline void do_nothing(void) { return; }