From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 91F5EC4320A for ; Mon, 23 Aug 2021 17:13:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7CCA461425 for ; Mon, 23 Aug 2021 17:13:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231679AbhHWRO2 (ORCPT ); Mon, 23 Aug 2021 13:14:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40018 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231653AbhHWROU (ORCPT ); Mon, 23 Aug 2021 13:14:20 -0400 Received: from mail-qt1-x849.google.com (mail-qt1-x849.google.com [IPv6:2607:f8b0:4864:20::849]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 157EAC0617AE for ; Mon, 23 Aug 2021 10:13:36 -0700 (PDT) Received: by mail-qt1-x849.google.com with SMTP id j23-20020ac86657000000b0029cb70967ebso3571456qtp.14 for ; Mon, 23 Aug 2021 10:13:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=OjHgDJUvJmMOnMd0mi83Z9bddC5eVI/HUOS0aA/fCjo=; b=Dna0EQXkdpMIYwRPENTuTtD45Xxz00+bPzyOn6DWxIcwL0q6aW6lkwtVlDnuMZuAEA 8sIkWePDkiji5yZon0dVb8HXmOr7mEzoHZ5lQQHdTzgZHGUhTEo6QEZ5jHCtKwjZa60J uNEz1aSczSOjajbuJjU/0lZ4076zCEjFHCzb/GzyleOAAJDdTiLueqUl6x5XGftohdwu U+8rspiV1W6jiMa8ujDzD710tDfqTvVPsz9/JR2Koyb14Kfwnn4SUA3EIPZ4b92ksJBL iYBJb7esO6wqajz4QMQjRtUQg/vPUrnXPvvvgrq2KcZy+42G0jJwrxzNFIPxfUOLIkFT QDMg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=OjHgDJUvJmMOnMd0mi83Z9bddC5eVI/HUOS0aA/fCjo=; b=Ms7xYEOr1tUAh82HYrwrbvS/p/OsatPlmvOJwrffAcsTMtvKzdodXYo1gb8/GZuH3j RTsc9wW0ooC+j1cV//I1L7foDYLPvT1vgxtbKQ4l4Gup4dLQifgRFl4BlSbPgwfJA2Ny nCtjIgpmTKlEQB2JKmRvpWjFsGwVbNJCSCUq5MZedJ+Lq8OXzkf16053coP4EF61kwyM U8g8XmLPVE3dyNoLtMM41IypouNJ6iwh2nErraQ+Y4pzDJpRmQ5c72xRz1r4Oy9uGCbq ygIM+CKUBAD25XuIbFOhJ3vA1skN+mgmo4OVASWkOkXgRl1hG5leFVr2lvzOA1a43Mzm S9Cg== X-Gm-Message-State: AOAM533JaUfAqNjwBd0lPlZyNkPypuubcSAGpcSmK8GbGIK7awqj/rMF GclO1+GTMRdmefElQS/f9FPbD8a+8uBxgh36M8M= X-Google-Smtp-Source: ABdhPJzi9cvrwOFBpM3xgvXo+JzAAlmiz1LkJnW74n84Ibws5mGYLA0Os3m+2on4AveQflOlFROtCJbTM/5knrZQjsg= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:cc48:aa6a:f4ec:7d19]) (user=samitolvanen job=sendgmr) by 2002:a05:6214:1142:: with SMTP id b2mr34567008qvt.0.1629738815199; Mon, 23 Aug 2021 10:13:35 -0700 (PDT) Date: Mon, 23 Aug 2021 10:13:10 -0700 In-Reply-To: <20210823171318.2801096-1-samitolvanen@google.com> Message-Id: <20210823171318.2801096-7-samitolvanen@google.com> Mime-Version: 1.0 References: <20210823171318.2801096-1-samitolvanen@google.com> X-Mailer: git-send-email 2.33.0.rc2.250.ged5fa647cd-goog Subject: [PATCH v2 06/14] lkdtm: Use an opaque type for lkdtm_rodata_do_nothing From: Sami Tolvanen To: x86@kernel.org Cc: Kees Cook , Josh Poimboeuf , Peter Zijlstra , Nathan Chancellor , Nick Desaulniers , Sedat Dilek , linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Sami Tolvanen Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Use an opaque type for lkdtm_rodata_do_nothing to stop the compiler from generating a CFI jump table entry that jumps to .rodata. Signed-off-by: Sami Tolvanen --- drivers/misc/lkdtm/lkdtm.h | 2 +- drivers/misc/lkdtm/perms.c | 2 +- drivers/misc/lkdtm/rodata.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/misc/lkdtm/lkdtm.h b/drivers/misc/lkdtm/lkdtm.h index 6a30b60519f3..90d92eb92c16 100644 --- a/drivers/misc/lkdtm/lkdtm.h +++ b/drivers/misc/lkdtm/lkdtm.h @@ -129,7 +129,7 @@ void lkdtm_REFCOUNT_TIMING(void); void lkdtm_ATOMIC_TIMING(void); /* rodata.c */ -void lkdtm_rodata_do_nothing(void); +DECLARE_ASM_FUNC_SYMBOL(lkdtm_rodata_do_nothing); /* usercopy.c */ void __init lkdtm_usercopy_init(void); diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c index 2dede2ef658f..fa2bd90bd8ee 100644 --- a/drivers/misc/lkdtm/perms.c +++ b/drivers/misc/lkdtm/perms.c @@ -151,7 +151,7 @@ void lkdtm_EXEC_VMALLOC(void) void lkdtm_EXEC_RODATA(void) { - execute_location(lkdtm_rodata_do_nothing, CODE_AS_IS); + execute_location((void *)lkdtm_rodata_do_nothing, CODE_AS_IS); } void lkdtm_EXEC_USERSPACE(void) diff --git a/drivers/misc/lkdtm/rodata.c b/drivers/misc/lkdtm/rodata.c index baacb876d1d9..17ed0ad4e6ae 100644 --- a/drivers/misc/lkdtm/rodata.c +++ b/drivers/misc/lkdtm/rodata.c @@ -3,7 +3,7 @@ * This includes functions that are meant to live entirely in .rodata * (via objcopy tricks), to validate the non-executability of .rodata. */ -#include "lkdtm.h" +void lkdtm_rodata_do_nothing(void); void noinstr lkdtm_rodata_do_nothing(void) { -- 2.33.0.rc2.250.ged5fa647cd-goog