From patchwork Tue Feb 15 12:41:05 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 12747029 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id CB2BFC433EF for ; Tue, 15 Feb 2022 12:41:41 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6247A6B0081; Tue, 15 Feb 2022 07:41:41 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 5D4126B0082; Tue, 15 Feb 2022 07:41:41 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 44F606B0083; Tue, 15 Feb 2022 07:41:41 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0062.hostedemail.com [216.40.44.62]) by kanga.kvack.org (Postfix) with ESMTP id 33CB06B0081 for ; Tue, 15 Feb 2022 07:41:41 -0500 (EST) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id DB9938B76B for ; Tue, 15 Feb 2022 12:41:40 +0000 (UTC) X-FDA: 79144975560.10.44CF27F Received: from pegase2.c-s.fr (pegase2.c-s.fr [93.17.235.10]) by imf14.hostedemail.com (Postfix) with ESMTP id 5EFDF100007 for ; Tue, 15 Feb 2022 12:41:40 +0000 (UTC) Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4Jyggt1WdHz9sRw; Tue, 15 Feb 2022 13:41:30 +0100 (CET) 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 vinG_He-9gjD; Tue, 15 Feb 2022 13:41:30 +0100 (CET) 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 4Jyggn4KfQz9sST; Tue, 15 Feb 2022 13:41:25 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 81D548B763; Tue, 15 Feb 2022 13:41:25 +0100 (CET) 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 QTIey80vSQHy; Tue, 15 Feb 2022 13:41:25 +0100 (CET) Received: from PO20335.IDSI0.si.c-s.fr (unknown [192.168.6.174]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 7BB778B77B; Tue, 15 Feb 2022 13:41:24 +0100 (CET) Received: from PO20335.IDSI0.si.c-s.fr (localhost [127.0.0.1]) by PO20335.IDSI0.si.c-s.fr (8.17.1/8.16.1) with ESMTPS id 21FCfHOn080645 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Tue, 15 Feb 2022 13:41:17 +0100 Received: (from chleroy@localhost) by PO20335.IDSI0.si.c-s.fr (8.17.1/8.17.1/Submit) id 21FCfHeR080644; Tue, 15 Feb 2022 13:41:17 +0100 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 v4 10/13] lkdtm: Force do_nothing() out of line Date: Tue, 15 Feb 2022 13:41:05 +0100 Message-Id: X-Mailer: git-send-email 2.34.1 In-Reply-To: References: MIME-Version: 1.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1644928860; l=1269; s=20211009; h=from:subject:message-id; bh=Qfe2la9R+/icLlKyEXlhAjPyrlVNcwt2uKVNooAPO2A=; b=PUqQRJ5Z3OSO7f5BoncMZOdMS2siQUwkpBmdIn0841YNUh5b5dGI0DIvkCrh6y2Oef6Xlz1Pd1ix xp0ZhccnCwmIOMabi3CewXL6jEcMjZBNMx+WVwbOuXj2aeGJeopa X-Developer-Key: i=christophe.leroy@csgroup.eu; a=ed25519; pk=HIzTzUj91asvincQGOFx6+ZF5AoUuP9GdOtQChs7Mm0= Authentication-Results: imf14.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf14.hostedemail.com: domain of christophe.leroy@csgroup.eu designates 93.17.235.10 as permitted sender) smtp.mailfrom=christophe.leroy@csgroup.eu X-Rspam-User: X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 5EFDF100007 X-Stat-Signature: janfgqawaw3j1wdbqfp7naez8xsdb8ai X-HE-Tag: 1644928900-407458 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; }