From patchwork Thu Oct 14 05:50:00 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 12557799 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 42E36C433FE for ; Thu, 14 Oct 2021 06:24:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 283D06117A for ; Thu, 14 Oct 2021 06:24:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229538AbhJNG0J (ORCPT ); Thu, 14 Oct 2021 02:26:09 -0400 Received: from pegase2.c-s.fr ([93.17.235.10]:45337 "EHLO pegase2.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229746AbhJNG0G (ORCPT ); Thu, 14 Oct 2021 02:26:06 -0400 Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4HVK9V2XGPz9sST; Thu, 14 Oct 2021 08:23:58 +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 ywvM8ua99sUG; Thu, 14 Oct 2021 08:23:58 +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 4HVK9V1df3z9sSK; Thu, 14 Oct 2021 08:23:58 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 2155E8B788; Thu, 14 Oct 2021 08:23:58 +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 LEgVpphJSeUz; Thu, 14 Oct 2021 08:23:58 +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 D44DA8B763; 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 19E5oQBY2266038 (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 19E5oQ4u2266037; 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 11/13] lkdtm: Fix lkdtm_EXEC_RODATA() Date: Thu, 14 Oct 2021 07:50:00 +0200 Message-Id: <44946ed0340013a52f8acdee7d6d0781f145cd6b.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=1315; s=20211009; h=from:subject:message-id; bh=rb6s8T8RzgppuRF6clvJIPiZDvSiUgRo2Ftj9cKfCbI=; b=IomnMzuLREpm22pqHiUGM7GaxjWQw6U4JqCv8E/AD7rCX5OHbqBvUX0igIGbFZcJnsdwgmpcgCOZ V9VbVBWuCT2ksy6IfSzsaHiA2GEOl5ZkQT1MMB8AK72+hu6d6ibU 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 Behind its location, lkdtm_EXEC_RODATA() executes lkdtm_rodata_do_nothing() which is a real function, not a copy of do_nothing(). So executes it directly instead of using execute_location(). This is necessary because following patch will fix execute_location() to use a copy of the function descriptor of do_nothing() and function descriptor of lkdtm_rodata_do_nothing() might be different. And fix displayed addresses by dereferencing the function descriptors. Signed-off-by: Christophe Leroy --- drivers/misc/lkdtm/perms.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c index 035fcca441f0..5266dc28df6e 100644 --- a/drivers/misc/lkdtm/perms.c +++ b/drivers/misc/lkdtm/perms.c @@ -153,7 +153,14 @@ void lkdtm_EXEC_VMALLOC(void) void lkdtm_EXEC_RODATA(void) { - execute_location(lkdtm_rodata_do_nothing, CODE_AS_IS); + pr_info("attempting ok execution at %px\n", + dereference_function_descriptor(do_nothing)); + do_nothing(); + + pr_info("attempting bad execution at %px\n", + dereference_function_descriptor(lkdtm_rodata_do_nothing)); + lkdtm_rodata_do_nothing(); + pr_err("FAIL: func returned\n"); } void lkdtm_EXEC_USERSPACE(void)