From patchwork Tue Mar 23 20:39:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12159271 X-Patchwork-Delegate: kuba@kernel.org 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 63557C4345F for ; Tue, 23 Mar 2021 20:41:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 35B56619E0 for ; Tue, 23 Mar 2021 20:41:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233652AbhCWUkk (ORCPT ); Tue, 23 Mar 2021 16:40:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45008 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233530AbhCWUkM (ORCPT ); Tue, 23 Mar 2021 16:40:12 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B62F7C0613DF for ; Tue, 23 Mar 2021 13:40:11 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id 6so3848794ybq.7 for ; Tue, 23 Mar 2021 13:40:11 -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=pXHCPErazdX/nDg2/nb6QksjLfEFTtrkU2uTHlahGRs=; b=jFt+TBSDKrmbmcTGUS3Zh3LQfQ9h6g78j1z40AyKg7NaLPpZHn37Ldl7vtccRAf8UV GppokLpY6wTAB+Sle9DrxlzNvmD7RLVB1LrLtLP+DoPSdOHThcUhWPgZsZMHr1AypqJp 2ausF2iw7I06q65bPHkkK5uKHVdZZ+ckMEmm7IBf/pcXpGFOQXgKf2NyXu+UF4y2zTd2 ycqljJ06Wbbus0bG5F1C0bgOjXenQJWv7VPFmvmSNViXRdLRYpO43wanLsM7EnyPPUa4 y3y0OHiuMRejUijcBoHlT618Iy/tBMRleGTHHjCIOalK/zQVBqz//LPDgG2CS2s+wtjo u2Nw== 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=pXHCPErazdX/nDg2/nb6QksjLfEFTtrkU2uTHlahGRs=; b=VerKLfaR85MoVVb1FlicXditZU59mKiNrkL6wGJWXkHfHLGuPUMPmKgDiVusDkR5Gp iueKU7fq6xrVDHBNrt/X5JpLEvzFVrBq77/zdQnDuZgIj7aPQqcKXvdWzPBgGdeWzn1G IoNpR9wEEWci6jqPfSmuFN6SExL3hFk7Qh3OgJiDKB9gcsaEkrRvcSvfkGmrnaLLugBN 6EJ+HpcbWht52U/m/BDjklTqUqvyyhmTeqHGmJUEcflQdfSsvw09uokH59G5O44uduqn b6dXGtmpX+G2VLa/toUj2/OXDWVtqb+y0G12N4yWsMbnv9K1f43X13J7qEQ/BzZ76XDh Z1zA== X-Gm-Message-State: AOAM530yiFbNA96Qapxhxjz1H+PSksFgfdWgpdgj9gdytbYmJXy26de8 yJ8wdPdZbxFC7GwclXnM1OwhpvoIug7bbwKs6fA= X-Google-Smtp-Source: ABdhPJy23IA9Pmn2B2QQVPkwdw9dKjsA0O0LWinFUMBV4532ZUThiTX267nWH6v33xCXfAmR7YR5nPY/6Ir/NDlbC70= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:e9a3:260d:763b:67dc]) (user=samitolvanen job=sendgmr) by 2002:a25:d3d3:: with SMTP id e202mr58822ybf.283.1616532011040; Tue, 23 Mar 2021 13:40:11 -0700 (PDT) Date: Tue, 23 Mar 2021 13:39:41 -0700 In-Reply-To: <20210323203946.2159693-1-samitolvanen@google.com> Message-Id: <20210323203946.2159693-13-samitolvanen@google.com> Mime-Version: 1.0 References: <20210323203946.2159693-1-samitolvanen@google.com> X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: [PATCH v3 12/17] arm64: implement __va_function From: Sami Tolvanen To: Kees Cook Cc: Nathan Chancellor , Nick Desaulniers , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , "Paul E. McKenney" , Christoph Hellwig , Peter Zijlstra , bpf@vger.kernel.org, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org With CONFIG_CFI_CLANG, the compiler replaces function addresses in instrumented C code with jump table addresses. This change implements the __va_function() macro, which returns the actual function address instead. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- arch/arm64/include/asm/memory.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 0aabc3be9a75..9a4887808681 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -321,6 +321,21 @@ static inline void *phys_to_virt(phys_addr_t x) #define virt_to_pfn(x) __phys_to_pfn(__virt_to_phys((unsigned long)(x))) #define sym_to_pfn(x) __phys_to_pfn(__pa_symbol(x)) +#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 __va_function macro always returns the address of the + * actual function instead. + */ +#define __va_function(x) ({ \ + void *addr; \ + asm("adrp %0, " __stringify(x) "\n\t" \ + "add %0, %0, :lo12:" __stringify(x) : "=r" (addr)); \ + addr; \ +}) +#endif + /* * virt_to_page(x) convert a _valid_ virtual address to struct page * * virt_addr_valid(x) indicates whether a virtual address is valid