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=-20.4 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 8C3EEC43463 for ; Mon, 21 Sep 2020 13:27:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 52F0F21D7A for ; Mon, 21 Sep 2020 13:27:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="CTsRusC0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726456AbgIUN0t (ORCPT ); Mon, 21 Sep 2020 09:26:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59738 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727203AbgIUN0p (ORCPT ); Mon, 21 Sep 2020 09:26:45 -0400 Received: from mail-qk1-x749.google.com (mail-qk1-x749.google.com [IPv6:2607:f8b0:4864:20::749]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AFB1DC0613D1 for ; Mon, 21 Sep 2020 06:26:44 -0700 (PDT) Received: by mail-qk1-x749.google.com with SMTP id j5so10861958qka.7 for ; Mon, 21 Sep 2020 06:26:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=Ix66qFhKSgSVrZqQyJftp2TjE15R0Twg+sH9CEm53D4=; b=CTsRusC0VpfrH6AP4frLdYd+UeeyjPQTPYZLk3YPw3dPpyo7SVxAO26BpWE11ZWSPQ uSC4T0QWzrWUS2WxaRekysQJlBp37jl2hGNZJyQiHllh7tx90+s6iCZvxCt/Hw4sdLkj u2SP6GCtU9pcT3lGTbYBmTyFmj+ooqG0galP6OV/pxSrwP3s+/NDH1w5Y247XTomei5m PCP6mD1gKGwqIwMDIO6OhwY/Qq2TJK2Avxj5GH0yF9w8VlxUxiPzKbIM1b2V2nh3NnuU KMg8ZakQBuHdW6HsF2NcpHVedeue1I4YGmMMVdgF+74bp98dlDO3TxRI3rmhxBWz3k/X Z81g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=Ix66qFhKSgSVrZqQyJftp2TjE15R0Twg+sH9CEm53D4=; b=TEEmxuJJ4AYIMTl6kwghuT19xoa3uIXBjvDlrsyEYdyU9mTTCGApM8RE+8H1v57kic K4Dx6Tf7/N0lztfBpWZ5MFEmADfaE4rDZsTV9pvsgsaZq7MNKn5IeuGUj7vrgDbCoT22 6zNXrr5ZJrrcqFzl6mndmNN7o47WsI3BFWJVNnKxA6ImjWZzjeqzjEQkRDtsWYnlfps2 PNEeHJqIf/brh5kJwIJJUefM/iuc3OCDnN7W2GBclgRgxDhAyMstbfr6hLah7sF83v1N a87cL0NsTtA8/GOckwHhu4eVbp3DcEbfmhKos7UcnDfWxq6IvTeViPjoXV4PqHawRlLc EJpQ== X-Gm-Message-State: AOAM531B/Vr18XbTp8kHIWKsAkIxobR2/Q6KpfHlVgvEyehSoOVS3gAl QhD4auhN7Tt/NGdVi+n6WiVPXmLBbg== X-Google-Smtp-Source: ABdhPJxr8iWU9tcA8f9QiW5hksbb0r4GfT178XXuYvyfsn71Bb1lS4SgSL5HWA6YlCdJxbWk836ueVS2jg== Sender: "elver via sendgmr" X-Received: from elver.muc.corp.google.com ([2a00:79e0:15:13:f693:9fff:fef4:2449]) (user=elver job=sendgmr) by 2002:ad4:4b34:: with SMTP id s20mr30490550qvw.51.1600694803653; Mon, 21 Sep 2020 06:26:43 -0700 (PDT) Date: Mon, 21 Sep 2020 15:26:04 +0200 In-Reply-To: <20200921132611.1700350-1-elver@google.com> Message-Id: <20200921132611.1700350-4-elver@google.com> Mime-Version: 1.0 References: <20200921132611.1700350-1-elver@google.com> X-Mailer: git-send-email 2.28.0.681.g6f77f65b4e-goog Subject: [PATCH v3 03/10] arm64, kfence: enable KFENCE for ARM64 From: Marco Elver To: elver@google.com, akpm@linux-foundation.org, glider@google.com Cc: hpa@zytor.com, paulmck@kernel.org, andreyknvl@google.com, aryabinin@virtuozzo.com, luto@kernel.org, bp@alien8.de, catalin.marinas@arm.com, cl@linux.com, dave.hansen@linux.intel.com, rientjes@google.com, dvyukov@google.com, edumazet@google.com, gregkh@linuxfoundation.org, hdanton@sina.com, mingo@redhat.com, jannh@google.com, Jonathan.Cameron@huawei.com, corbet@lwn.net, iamjoonsoo.kim@lge.com, keescook@chromium.org, mark.rutland@arm.com, penberg@kernel.org, peterz@infradead.org, sjpark@amazon.com, tglx@linutronix.de, vbabka@suse.cz, will@kernel.org, x86@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org Add architecture specific implementation details for KFENCE and enable KFENCE for the arm64 architecture. In particular, this implements the required interface in . Currently, the arm64 version does not yet use a statically allocated memory pool, at the cost of a pointer load for each is_kfence_address(). Reviewed-by: Dmitry Vyukov Co-developed-by: Alexander Potapenko Signed-off-by: Alexander Potapenko Signed-off-by: Marco Elver --- For ARM64, we would like to solicit feedback on what the best option is to obtain a constant address for __kfence_pool. One option is to declare a memory range in the memory layout to be dedicated to KFENCE (like is done for KASAN), however, it is unclear if this is the best available option. We would like to avoid touching the memory layout. --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/kfence.h | 39 +++++++++++++++++++++++++++++++++ arch/arm64/mm/fault.c | 4 ++++ 3 files changed, 44 insertions(+) create mode 100644 arch/arm64/include/asm/kfence.h diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 6d232837cbee..1acc6b2877c3 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -132,6 +132,7 @@ config ARM64 select HAVE_ARCH_JUMP_LABEL_RELATIVE select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN + select HAVE_ARCH_KFENCE if (!ARM64_16K_PAGES && !ARM64_64K_PAGES) select HAVE_ARCH_KGDB select HAVE_ARCH_MMAP_RND_BITS select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT diff --git a/arch/arm64/include/asm/kfence.h b/arch/arm64/include/asm/kfence.h new file mode 100644 index 000000000000..608dde80e5ca --- /dev/null +++ b/arch/arm64/include/asm/kfence.h @@ -0,0 +1,39 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __ASM_KFENCE_H +#define __ASM_KFENCE_H + +#include +#include +#include + +#include + +#define KFENCE_SKIP_ARCH_FAULT_HANDLER "el1_sync" + +/* + * FIXME: Support HAVE_ARCH_KFENCE_STATIC_POOL: Use the statically allocated + * __kfence_pool, to avoid the extra pointer load for is_kfence_address(). By + * default, however, we do not have struct pages for static allocations. + */ + +static inline bool arch_kfence_initialize_pool(void) +{ + const unsigned int num_pages = ilog2(roundup_pow_of_two(KFENCE_POOL_SIZE / PAGE_SIZE)); + struct page *pages = alloc_pages(GFP_KERNEL, num_pages); + + if (!pages) + return false; + + __kfence_pool = page_address(pages); + return true; +} + +static inline bool kfence_protect_page(unsigned long addr, bool protect) +{ + set_memory_valid(addr, 1, !protect); + + return true; +} + +#endif /* __ASM_KFENCE_H */ diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index f07333e86c2f..d5b72ecbeeea 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include #include @@ -310,6 +311,9 @@ static void __do_kernel_fault(unsigned long addr, unsigned int esr, "Ignoring spurious kernel translation fault at virtual address %016lx\n", addr)) return; + if (kfence_handle_page_fault(addr)) + return; + if (is_el1_permission_fault(addr, esr, regs)) { if (esr & ESR_ELx_WNR) msg = "write to read-only memory"; -- 2.28.0.681.g6f77f65b4e-goog