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=-16.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 E78DCC4338F for ; Wed, 25 Aug 2021 13:18:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C9D416108F for ; Wed, 25 Aug 2021 13:18:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241173AbhHYNTl (ORCPT ); Wed, 25 Aug 2021 09:19:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53014 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232589AbhHYNTk (ORCPT ); Wed, 25 Aug 2021 09:19:40 -0400 Received: from mail-pl1-x629.google.com (mail-pl1-x629.google.com [IPv6:2607:f8b0:4864:20::629]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 60A36C061757 for ; Wed, 25 Aug 2021 06:18:54 -0700 (PDT) Received: by mail-pl1-x629.google.com with SMTP id j2so9902637pll.1 for ; Wed, 25 Aug 2021 06:18:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding:content-language; bh=4ik/eFnY7+CuzmSUYisgf/KLeW0T92g5imVQVoUtu5U=; b=SoU40/GXX37JX5ldvP7VR62In+e75SpTCrmUKETBWribIDwWB8unlY61T9fVRkSqaN 3Oxj20kczAYSVIZSKQqO5f+aqwM/oUh91yLfVngFCwQpJ9XkGpXRNTW6v1F1PM/EW/gR MI9zD+NJ5q891g4Qd5s/9MGEfuZwURR4HeLnAeJaSZmPFF08O5QjpAHHVAomTjIs2C3b DYy8nvOwIGPIv5BRtjVNrFOAsT0uKKt0QqhtZpp1frgbAZHjbMAw47OCNvuZrXFPsgf6 nXsIpbV+i+BdkgrgJTWJGJvi8/oFnmcpV0/GgR6y651VH0pOXxRMwBgC9RuoIM9y22Ix Cg5A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=4ik/eFnY7+CuzmSUYisgf/KLeW0T92g5imVQVoUtu5U=; b=ZSHReO1fVQs9l8z7WlS70aHsPUS38VJbmjBgWPSNdQjJPUPpC8813HdRyC9UpF2ooc R7hng4G5tSsSfe6OjPsHXgUiVTCWUtcgEj8m4FTE4v+YtMRZD4kNiLyt3DZMMMWp95xz k92D0RBtxXvFGgncXDu5mIHYdFsqpN8+41/GQDoivUAx4CeVunuZQ8dFSWH/HA+FLSHG h3W5Zzs5EISJOpFDUjYp8V9HVZrdj37Y36955ebG9kkJBhTlroO/WTAYaDs+dczDOggR XxY4w9Rk1Yl6fx/0kRiFhVgMLjjID2fFNMoPb7A6xa8cGVd9j/7YGes1NcCyRX/+ui07 ViTw== X-Gm-Message-State: AOAM532JLf+uQtNuVFMaS05zxs9IDqj8DAZwSin3dRjj/BT0IQghlJLi cCesrIi8W4cnSKbYElqbRN0= X-Google-Smtp-Source: ABdhPJyPzbNUVZtiPa+4RWuRZh7fvF6egYCN1AEvgYLKF7aMYWQcoURxf+5sSN8nPf9284E3+rh+ng== X-Received: by 2002:a17:90a:c88:: with SMTP id v8mr10716479pja.197.1629897533805; Wed, 25 Aug 2021 06:18:53 -0700 (PDT) Received: from owniadeMacBook-Pro.local ([103.97.201.4]) by smtp.gmail.com with ESMTPSA id p24sm6945858pfh.136.2021.08.25.06.18.51 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 25 Aug 2021 06:18:53 -0700 (PDT) Subject: Re: [PATCH 3/4] ARM: Support KFENCE for ARM To: Kefeng Wang Cc: Russell King , Alexander Potapenko , Marco Elver , Andrew Morton , Dmitry Vyukov , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kasan-dev@googlegroups.com References: <20210825092116.149975-1-wangkefeng.wang@huawei.com> <20210825092116.149975-4-wangkefeng.wang@huawei.com> From: ownia Message-ID: <51b02ecd-0f3d-99b0-c943-1d4da26174d0@gmail.com> Date: Wed, 25 Aug 2021 21:18:49 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <20210825092116.149975-4-wangkefeng.wang@huawei.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/8/25 17:21, Kefeng Wang wrote: > 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. > > Signed-off-by: Kefeng Wang > --- > arch/arm/Kconfig | 1 + > arch/arm/include/asm/kfence.h | 52 +++++++++++++++++++++++++++++++++++ > arch/arm/mm/fault.c | 9 ++++-- > 3 files changed, 60 insertions(+), 2 deletions(-) > create mode 100644 arch/arm/include/asm/kfence.h > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index 7a8059ff6bb0..3798f82a0c0d 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -73,6 +73,7 @@ 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 > 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..eae7a12ab2a9 > --- /dev/null > +++ b/arch/arm/include/asm/kfence.h > @@ -0,0 +1,52 @@ > +/* 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 & PMD_MASK))); > + 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)) > + 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 f7ab6dabe89f..9fa221ffa1b9 100644 > --- a/arch/arm/mm/fault.c > +++ b/arch/arm/mm/fault.c > @@ -17,6 +17,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -131,10 +132,14 @@ __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"; > + } I think here should do some fixup to follow upstream mainline code. > > die_kernel_fault(msg, mm, addr, fsr, regs); > }