From patchwork Thu Oct 14 05:49:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 12557797 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 611A7C433F5 for ; Thu, 14 Oct 2021 06:24:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 47F3F61152 for ; Thu, 14 Oct 2021 06:24:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229551AbhJNG0E (ORCPT ); Thu, 14 Oct 2021 02:26:04 -0400 Received: from pegase2.c-s.fr ([93.17.235.10]:40411 "EHLO pegase2.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229530AbhJNG0E (ORCPT ); Thu, 14 Oct 2021 02:26:04 -0400 Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4HVK9T6nbXz9sSL; Thu, 14 Oct 2021 08:23:57 +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 CvtZxXja-epj; Thu, 14 Oct 2021 08:23:57 +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 4HVK9T5vlfz9sSK; Thu, 14 Oct 2021 08:23:57 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id B25FB8B788; Thu, 14 Oct 2021 08:23:57 +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 9CecoLzJnjFF; Thu, 14 Oct 2021 08:23:57 +0200 (CEST) Received: from PO20335.IDSI0.si.c-s.fr (unknown [192.168.202.231]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 670478B763; Thu, 14 Oct 2021 08:23:57 +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 19E5oQQr2266030 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Thu, 14 Oct 2021 07:50:26 +0200 Received: (from chleroy@localhost) by PO20335.IDSI0.si.c-s.fr (8.16.1/8.16.1/Submit) id 19E5oQCx2266029; Thu, 14 Oct 2021 07:50:26 +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 v2 09/13] lkdtm: Force do_nothing() out of line Date: Thu, 14 Oct 2021 07:49:58 +0200 Message-Id: <44c2261293843b71cd0a7f485f889dd51deb5fe7.1634190022.git.christophe.leroy@csgroup.eu> 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=1634190596; l=1269; s=20211009; h=from:subject:message-id; bh=nSN/ioO339qfxQaSJCJwz7QKogrcJ3f1Q+xuI0OSdUc=; b=SZl099RfUAV+FVdlnVISlQznXLCQsoqksayWb2M+8ULE2HhrQME0NQADNu3fs/gMPsgAnsTZ9Esk Np5U4MTuD2D1rOZ7sGCel7PdwzwFG+ENEKVrBlWY5U/OCStZGBJg X-Developer-Key: i=christophe.leroy@csgroup.eu; a=ed25519; pk=HIzTzUj91asvincQGOFx6+ZF5AoUuP9GdOtQChs7Mm0= Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org 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; }