From patchwork Thu Mar 18 17:11:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12148823 X-Patchwork-Delegate: bpf@iogearbox.net 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, URIBL_BLOCKED,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 27B58C43333 for ; Thu, 18 Mar 2021 17:12:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EF7F864F68 for ; Thu, 18 Mar 2021 17:12:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232319AbhCRRMN (ORCPT ); Thu, 18 Mar 2021 13:12:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232363AbhCRRLm (ORCPT ); Thu, 18 Mar 2021 13:11:42 -0400 Received: from mail-pg1-x549.google.com (mail-pg1-x549.google.com [IPv6:2607:f8b0:4864:20::549]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1C4D6C06175F for ; Thu, 18 Mar 2021 10:11:42 -0700 (PDT) Received: by mail-pg1-x549.google.com with SMTP id l133so3310825pga.6 for ; Thu, 18 Mar 2021 10:11:42 -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=Jby0dukBhmBgpcZA/U36PC7iwDl1fv9sQJbWlIVJR6zC612oDIVCBEc9ib6jIIxa0Z h5H6tDnzD6sQrwQMtWQSrqnjf3jc+BTx3l1kMPLJSmJpjBwlNsG6Ieg3A9gk5xckevvW iDnyS60I+9Am2qOYj40KEO3FE6Xz316ybVZVYMUe9gMTHsS1+xCHi/MC2DH9I4fhZO+C d515fn/284/aSzYDxgzvA0yX3tKbC3EzzU7nrrgOVnfFeSfAsc2UQmp2/rPxZf9k5Vlq 1aqhpEgyS537j0Tsx8A/UMEZWjWvxC3GlheGZ6yYXmPEt9TCJDaVY5VxmGIulC5HNXVb 35Wg== 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=kJ+90CLVOV6H1J6i6i1gC1r5I7EHfINP2fwAcUs+VQx+rlGX2jtGYOcG7caLQ+CYfB njY7DDgOz4UOKYIKqzONGYa0/NvRwpr+0qb8QJTOurv6QfkUnXFQqPGGZ8hb2EKpu++B oq1LBelUndSYNivZz6uGh7Hceqd0x0aatPiI1iGF7g5PnX7Mf9YUsHEqm/zoHgxQKfMa mQ8shjj44+Ztta/12w0mHnDFQYpAEive+AxaUWUVYHAAqrAudNwt8LpUGKeHXrQb4Kgh wSOB6qg9xaiipor+RW7GeWt1s3QuZrfLzz6YAVT5ddvEwVuAFzCub3DEikDzpw3KkijW iOqA== X-Gm-Message-State: AOAM530YvwwgiR2g2cuKYPUPA5YkpzpGqXOhxQqBAaM839HRZ4GoBLCj gWyF3uxRL5AyKwmolpAEgEddcfxmtnTjzUM44pU= X-Google-Smtp-Source: ABdhPJz7QmlOkNqtn9QR9fE9OonDa8rHz2twqoehDg1I2GIjzKha//VEA73ZQxvmwzcKfV3ni3UGXnqikRS1ctkOawE= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:c0d7:a7ba:fb41:a35a]) (user=samitolvanen job=sendgmr) by 2002:a62:ea19:0:b029:1ee:5911:c516 with SMTP id t25-20020a62ea190000b02901ee5911c516mr4956591pfh.67.1616087501527; Thu, 18 Mar 2021 10:11:41 -0700 (PDT) Date: Thu, 18 Mar 2021 10:11:06 -0700 In-Reply-To: <20210318171111.706303-1-samitolvanen@google.com> Message-Id: <20210318171111.706303-13-samitolvanen@google.com> Mime-Version: 1.0 References: <20210318171111.706303-1-samitolvanen@google.com> X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: [PATCH v2 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 , 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