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 CD56FC433B4 for ; Fri, 16 Apr 2021 20:39:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B4FD3613D4 for ; Fri, 16 Apr 2021 20:39:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343837AbhDPUj0 (ORCPT ); Fri, 16 Apr 2021 16:39:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41248 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343674AbhDPUjW (ORCPT ); Fri, 16 Apr 2021 16:39:22 -0400 Received: from mail-qt1-x84a.google.com (mail-qt1-x84a.google.com [IPv6:2607:f8b0:4864:20::84a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4FA41C061760 for ; Fri, 16 Apr 2021 13:38:57 -0700 (PDT) Received: by mail-qt1-x84a.google.com with SMTP id o17-20020ac869910000b02901a7c59f1c14so6787729qtq.13 for ; Fri, 16 Apr 2021 13:38:57 -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=aY+by2sfCpbHCEdjbOQBS7MTkTUc3k2rkTxgoQckLqo=; b=Im3IocGwO9YFJ6VH4rQo49yBHnqdFgUpUQkTVi3qo3NST/5NgsJMQ+TdzIgMyhSR8G rg/5oHXno1DRk5pL5yWYCIpRVtvwMr5wdg/7sZ/JqHuSyh0K/nZbH+YizOcnfLZxjA9y a27XL33qn9FWiBLzgHnpUQxZCnEfIOgSia0itNtO4ddbDCSmpBCSKTtEuY1Mp86G55QT vdFJnGKPYlhn/1Iwc+xO2PMBZUTtHD38L+UVruq8H5+wxNDe06AnJ48kzsjfgpCSou+H yY02a8UGk9QItfJJC0uJ5MBAMRRsEna+d0rX3x+BUYzD6rNzLWfAaOK2FUJpD9GuN9r7 1tWw== 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=aY+by2sfCpbHCEdjbOQBS7MTkTUc3k2rkTxgoQckLqo=; b=cG16HYBzsV1YgsJznZOZ9L68fRn1JRRSLpegKk9Oa+FCKFHcCkdu/sWE0eQi6v3AIC r5kKCUqxyqLlR1jayZrI6N4lqc67I98PvqNE2+rM0Auo2+TfsMm+S/v8miSmFlPNkvcf cPdjZt/6uPDKpPktzms9R351qCO6jttmxitxURSqc51HIOFrykLamQXQWvVtkEjPhraA qPabB4ZZeqR7tEuTZRNpaoyM8LG8uXGo++7wZVlfqxMyAWJBiaFaGL6ZWpWtybpdjN1D BnhCJBATichXTbmZ6WixcZ553YjDG6Sm4IyczQOjYhPA8HIb/4oSh8RM8wJT5VL4AG5N tf3A== X-Gm-Message-State: AOAM530LT7+D1svOnvHUs/LxKBAsEO4G0kRnO/WmITPnGnyfM1/zc6Gn uqprf4pYaxzkQzVH9ThoHQPmCZ7fIwekZoaxjps= X-Google-Smtp-Source: ABdhPJx7jRoAmenzmCcYKAbuR9t5VWv3GmzLBrBMyxEX6XR7mV3d/eNvgwQ9FHrSdjficlJTFqDpjw96mfSrHX0SvdI= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:e262:3d8e:cbf:6164]) (user=samitolvanen job=sendgmr) by 2002:ad4:420a:: with SMTP id k10mr10548306qvp.50.1618605536511; Fri, 16 Apr 2021 13:38:56 -0700 (PDT) Date: Fri, 16 Apr 2021 13:38:34 -0700 In-Reply-To: <20210416203844.3803177-1-samitolvanen@google.com> Message-Id: <20210416203844.3803177-6-samitolvanen@google.com> Mime-Version: 1.0 References: <20210416203844.3803177-1-samitolvanen@google.com> X-Mailer: git-send-email 2.31.1.368.gbe11c130af-goog Subject: [PATCH 05/15] x86: Implement function_nocfi 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 With CONFIG_CFI_CLANG, the compiler replaces function addresses in instrumented C code with jump table addresses. This change implements the function_nocfi() macro, which returns the actual function address instead. Signed-off-by: Sami Tolvanen --- arch/x86/include/asm/page.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/arch/x86/include/asm/page.h b/arch/x86/include/asm/page.h index 7555b48803a8..5499a05c44fc 100644 --- a/arch/x86/include/asm/page.h +++ b/arch/x86/include/asm/page.h @@ -71,6 +71,20 @@ static inline void copy_user_page(void *to, void *from, unsigned long vaddr, extern bool __virt_addr_valid(unsigned long kaddr); #define virt_addr_valid(kaddr) __virt_addr_valid((unsigned long) (kaddr)) +#ifdef CONFIG_CFI_CLANG +/* + * With CONFIG_CFI_CLANG, the compiler replaces function address + * references with the address of the function's CFI jump table + * entry. The function_nocfi macro always returns the address of the + * actual function instead. + */ +#define function_nocfi(x) ({ \ + void *addr; \ + asm("leaq " __stringify(x) "(%%rip), %0\n\t" : "=r" (addr)); \ + addr; \ +}) +#endif + #endif /* __ASSEMBLY__ */ #include -- 2.31.1.368.gbe11c130af-goog