From patchwork Fri Mar 12 00:49:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12133467 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, 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 E4709C4646C for ; Fri, 12 Mar 2021 00:50:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B170F64F82 for ; Fri, 12 Mar 2021 00:50:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231373AbhCLAts (ORCPT ); Thu, 11 Mar 2021 19:49:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51960 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231247AbhCLAt1 (ORCPT ); Thu, 11 Mar 2021 19:49:27 -0500 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 267A4C061764 for ; Thu, 11 Mar 2021 16:49:27 -0800 (PST) Received: by mail-qt1-x849.google.com with SMTP id k15so16854786qtx.15 for ; Thu, 11 Mar 2021 16:49:27 -0800 (PST) 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=CeeN3xK5WAqMYQUfCf/QpaYnEzhU3e+FKSYu/FFXY8U=; b=YnzwiV3Orw5sKBr6YMDFmOYncBsKWDPtb68ypzRHMVK3VthGHiIWe4l2U/YxjypRBN wsdCMJQ8zMQ4WArlh/izxsQg9B1HPq7k4+zQzGqy/xvNVcvrOCu/A8nWO7g/+YjeuX2h jGDQ6MfChdyYhzfQCswFV9W0HW6D3ltx+MimGyrgUD1x+t+Bx9gPsDldUro2PNx4V8IN W7Zh/Yi/mTibl7LPNJ8pYn5eEyxkejmEbIYlhqwbmdNSdCR37OXx0M/R0WNI7f5943RF Jxme+nNTOcM7RlsIuIDWP8FV2CKIsNqPYMxSMUacQp9r5XEU2NLvZY8ysWVBhk0rMnGD iC0A== 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=CeeN3xK5WAqMYQUfCf/QpaYnEzhU3e+FKSYu/FFXY8U=; b=aM3BwJwtkVJ4JhlMzvqV7boqparwUCsr2F/LTHzcO417tTde25Mzhw4ltz8hg2YBSK SgUef6lzlZOCzLypUML5laFR6bXKUTR9nmFaieqe/oBkX+PXL6eqdD6x6PdTxrZ9L5ZJ lJIqHi6wYfP5doPkTWHZi8M4KBKh81Xeyq8tcNyWXe+yJPOTFdvRTIeEUZydLN89PRPj hSEB+elGm+KWj4S9KZBV3UbQ+vUID8ztVpp1SBVLYv8Uie3svTwr3ndKFJlzEd7m2TM2 6QaOUNfCACQSkYTO4ufQWXoxZHBzoIV9Zmd6wICKMOld8VtEIsuoglioD3lTKeu2JRl+ FB0A== X-Gm-Message-State: AOAM5321ISOsQhLPGa8bxGRaD8KoVWzJCpX+kOoAyZCdWU4JnbTc8j0D DxNFOVk7pmiw+lEqzcFgJPccZf+QsZuGwFqWJHQ= X-Google-Smtp-Source: ABdhPJwjquHhXc1azJY3wJx2N7E06CHn55yFR9L2LbefYUmXDDh/IrCaqT99xH2KOyCrVwPGAoCRUF+Cuh4wGPAPnqw= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:c86b:8269:af92:55a]) (user=samitolvanen job=sendgmr) by 2002:a05:6214:1144:: with SMTP id b4mr10460988qvt.12.1615510166369; Thu, 11 Mar 2021 16:49:26 -0800 (PST) Date: Thu, 11 Mar 2021 16:49:05 -0800 In-Reply-To: <20210312004919.669614-1-samitolvanen@google.com> Message-Id: <20210312004919.669614-4-samitolvanen@google.com> Mime-Version: 1.0 References: <20210312004919.669614-1-samitolvanen@google.com> X-Mailer: git-send-email 2.31.0.rc2.261.g7f71774620-goog Subject: [PATCH 03/17] mm: add generic __va_function and __pa_function macros From: Sami Tolvanen To: Kees Cook Cc: Nathan Chancellor , Nick Desaulniers , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , 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 means that __pa_symbol(function) returns the physical address of the jump table entry instead of the actual function, which may not work as the jump table code will immediately jump to a virtual address that may not be mapped. To avoid this address space confusion, this change adds generic definitions for __va_function and __pa_function, which architectures that support CFI can override. The typical implementation of the __va_function macro would use inline assembly to take the function address, which avoids compiler instrumentation. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- include/linux/mm.h | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index 77e64e3eac80..1262c4c0242c 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -116,6 +116,14 @@ extern int mmap_rnd_compat_bits __read_mostly; #define __pa_symbol(x) __pa(RELOC_HIDE((unsigned long)(x), 0)) #endif +#ifndef __va_function +#define __va_function(x) (x) +#endif + +#ifndef __pa_function +#define __pa_function(x) __pa_symbol(__va_function(x)) +#endif + #ifndef page_to_virt #define page_to_virt(x) __va(PFN_PHYS(page_to_pfn(x))) #endif