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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B17E1C433EF for ; Mon, 15 Nov 2021 13:39:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 97D5A6322C for ; Mon, 15 Nov 2021 13:39:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231911AbhKONmF (ORCPT ); Mon, 15 Nov 2021 08:42:05 -0500 Received: from szxga02-in.huawei.com ([45.249.212.188]:26314 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231845AbhKONk3 (ORCPT ); Mon, 15 Nov 2021 08:40:29 -0500 Received: from dggemv711-chm.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4Ht99357WXzbhDY; Mon, 15 Nov 2021 21:32:23 +0800 (CST) Received: from dggpemm500001.china.huawei.com (7.185.36.107) by dggemv711-chm.china.huawei.com (10.1.198.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Mon, 15 Nov 2021 21:37:17 +0800 Received: from localhost.localdomain.localdomain (10.175.113.25) by dggpemm500001.china.huawei.com (7.185.36.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Mon, 15 Nov 2021 21:37:17 +0800 From: Kefeng Wang To: , , CC: , , , Kefeng Wang Subject: [PATCH Resend v2 3/3] ARM: Support KFENCE for ARM Date: Mon, 15 Nov 2021 21:48:48 +0800 Message-ID: <20211115134848.171098-4-wangkefeng.wang@huawei.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20211115134848.171098-1-wangkefeng.wang@huawei.com> References: <20211115134848.171098-1-wangkefeng.wang@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.113.25] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpemm500001.china.huawei.com (7.185.36.107) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add architecture specific implementation details for KFENCE and enable KFENCE on ARM. In particular, this implements the required interface in . KFENCE requires that attributes for pages from its memory pool can individually be set. Therefore, force the kfence pool to be mapped at page granularity. Testing this patch using the testcases in kfence_test.c and all passed with or without ARM_LPAE. Acked-by: Marco Elver Signed-off-by: Kefeng Wang --- arch/arm/Kconfig | 1 + arch/arm/include/asm/kfence.h | 53 +++++++++++++++++++++++++++++++++++ arch/arm/mm/fault.c | 9 ++++-- 3 files changed, 61 insertions(+), 2 deletions(-) create mode 100644 arch/arm/include/asm/kfence.h diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index f0f9e8bec83a..321b0a1c2820 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -69,6 +69,7 @@ config ARM select HAVE_ARCH_AUDITSYSCALL if AEABI && !OABI_COMPAT select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU + select HAVE_ARCH_KFENCE if MMU && !XIP_KERNEL select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL select HAVE_ARCH_MMAP_RND_BITS if MMU diff --git a/arch/arm/include/asm/kfence.h b/arch/arm/include/asm/kfence.h new file mode 100644 index 000000000000..7980d0f2271f --- /dev/null +++ b/arch/arm/include/asm/kfence.h @@ -0,0 +1,53 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __ASM_ARM_KFENCE_H +#define __ASM_ARM_KFENCE_H + +#include + +#include +#include + +static inline int split_pmd_page(pmd_t *pmd, unsigned long addr) +{ + int i; + unsigned long pfn = PFN_DOWN(__pa(addr)); + pte_t *pte = pte_alloc_one_kernel(&init_mm); + + if (!pte) + return -ENOMEM; + + for (i = 0; i < PTRS_PER_PTE; i++) + set_pte_ext(pte + i, pfn_pte(pfn + i, PAGE_KERNEL), 0); + pmd_populate_kernel(&init_mm, pmd, pte); + + flush_tlb_kernel_range(addr, addr + PMD_SIZE); + return 0; +} + +static inline bool arch_kfence_init_pool(void) +{ + unsigned long addr; + pmd_t *pmd; + + for (addr = (unsigned long)__kfence_pool; is_kfence_address((void *)addr); + addr += PAGE_SIZE) { + pmd = pmd_off_k(addr); + + if (pmd_leaf(*pmd)) { + if (split_pmd_page(pmd, addr & PMD_MASK)) + return false; + } + } + + return true; +} + +static inline bool kfence_protect_page(unsigned long addr, bool protect) +{ + set_memory_valid(addr, 1, !protect); + + return true; +} + +#endif /* __ASM_ARM_KFENCE_H */ diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index 1207ed925039..49148b675b43 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include @@ -136,10 +137,14 @@ __do_kernel_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, /* * No handler, we'll have to terminate things with extreme prejudice. */ - if (addr < PAGE_SIZE) + if (addr < PAGE_SIZE) { msg = "NULL pointer dereference"; - else + } else { + if (kfence_handle_page_fault(addr, is_write_fault(fsr), regs)) + return; + msg = "paging request"; + } die_kernel_fault(msg, mm, addr, fsr, regs); } -- 2.26.2