From patchwork Fri Dec 18 22:03:26 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 11983097 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=-15.8 required=3.0 tests=BAYES_00,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 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 34950C4361B for ; Fri, 18 Dec 2020 22:03:30 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D8E5F23BA9 for ; Fri, 18 Dec 2020 22:03:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D8E5F23BA9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 824FB6B0092; Fri, 18 Dec 2020 17:03:29 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 7857A6B0093; Fri, 18 Dec 2020 17:03:29 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 626196B0095; Fri, 18 Dec 2020 17:03:29 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0215.hostedemail.com [216.40.44.215]) by kanga.kvack.org (Postfix) with ESMTP id 44B1E6B0092 for ; Fri, 18 Dec 2020 17:03:29 -0500 (EST) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 0D8A352AC for ; Fri, 18 Dec 2020 22:03:29 +0000 (UTC) X-FDA: 77607780138.04.rub24_170ab3a27440 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin04.hostedemail.com (Postfix) with ESMTP id E49A9801D1CB for ; Fri, 18 Dec 2020 22:03:28 +0000 (UTC) X-HE-Tag: rub24_170ab3a27440 X-Filterd-Recvd-Size: 8669 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf26.hostedemail.com (Postfix) with ESMTP for ; Fri, 18 Dec 2020 22:03:28 +0000 (UTC) Date: Fri, 18 Dec 2020 14:03:26 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1608329007; bh=76oWDf5f4w1BlWSph6gBIkwhthhPKhw/sXWIAqJa58Y=; h=From:To:Subject:In-Reply-To:From; b=wflsU9xZULkd8PO57ZZv2QYJMa+lCYBLDvSgTiD+oQOHbqiFif7aVnL1EnOqPw/Id nPcRiLHFEVxYzK9XEzRYh1Z4sOU2Z+nJq2lgFIEHAKKDHtZ3ac5UeDAJ3lWqrvACE8 V//KC7KzR+btvXoCKUeE2IS0VPxRzq1U48y7DP58= From: Andrew Morton To: akpm@linux-foundation.org, andreyknvl@google.com, aryabinin@virtuozzo.com, Branislav.Rankov@arm.com, catalin.marinas@arm.com, dvyukov@google.com, elver@google.com, eugenis@google.com, glider@google.com, gor@linux.ibm.com, kevin.brodsky@arm.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, vincenzo.frascino@arm.com, will.deacon@arm.com Subject: [patch 37/78] arm64: mte: add in-kernel MTE helpers Message-ID: <20201218220326.MNvex-upo%akpm@linux-foundation.org> In-Reply-To: <20201218140046.497484741326828e5b5d46ec@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Vincenzo Frascino Subject: arm64: mte: add in-kernel MTE helpers Provide helper functions to manipulate allocation and pointer tags for kernel addresses. Low-level helper functions (mte_assign_*, written in assembly) operate tag values from the [0x0, 0xF] range. High-level helper functions (mte_get/set_*) use the [0xF0, 0xFF] range to preserve compatibility with normal kernel pointers that have 0xFF in their top byte. MTE_GRANULE_SIZE and related definitions are moved to mte-def.h header that doesn't have any dependencies and is safe to include into any low-level header. Link: https://lkml.kernel.org/r/c31bf759b4411b2d98cdd801eb928e241584fd1f.1606161801.git.andreyknvl@google.com Signed-off-by: Vincenzo Frascino Co-developed-by: Andrey Konovalov Signed-off-by: Andrey Konovalov Reviewed-by: Catalin Marinas Tested-by: Vincenzo Frascino Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Branislav Rankov Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Kevin Brodsky Cc: Marco Elver Cc: Vasily Gorbik Cc: Will Deacon Signed-off-by: Andrew Morton --- arch/arm64/include/asm/esr.h | 1 arch/arm64/include/asm/mte-def.h | 15 +++++++ arch/arm64/include/asm/mte-kasan.h | 56 +++++++++++++++++++++++++++ arch/arm64/include/asm/mte.h | 20 ++++++--- arch/arm64/kernel/mte.c | 48 +++++++++++++++++++++++ arch/arm64/lib/mte.S | 16 +++++++ 6 files changed, 150 insertions(+), 6 deletions(-) --- a/arch/arm64/include/asm/esr.h~arm64-mte-add-in-kernel-mte-helpers +++ a/arch/arm64/include/asm/esr.h @@ -106,6 +106,7 @@ #define ESR_ELx_FSC_TYPE (0x3C) #define ESR_ELx_FSC_LEVEL (0x03) #define ESR_ELx_FSC_EXTABT (0x10) +#define ESR_ELx_FSC_MTE (0x11) #define ESR_ELx_FSC_SERROR (0x11) #define ESR_ELx_FSC_ACCESS (0x08) #define ESR_ELx_FSC_FAULT (0x04) --- /dev/null +++ a/arch/arm64/include/asm/mte-def.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2020 ARM Ltd. + */ +#ifndef __ASM_MTE_DEF_H +#define __ASM_MTE_DEF_H + +#define MTE_GRANULE_SIZE UL(16) +#define MTE_GRANULE_MASK (~(MTE_GRANULE_SIZE - 1)) +#define MTE_TAG_SHIFT 56 +#define MTE_TAG_SIZE 4 +#define MTE_TAG_MASK GENMASK((MTE_TAG_SHIFT + (MTE_TAG_SIZE - 1)), MTE_TAG_SHIFT) +#define MTE_TAG_MAX (MTE_TAG_MASK >> MTE_TAG_SHIFT) + +#endif /* __ASM_MTE_DEF_H */ --- a/arch/arm64/include/asm/mte.h~arm64-mte-add-in-kernel-mte-helpers +++ a/arch/arm64/include/asm/mte.h @@ -5,14 +5,16 @@ #ifndef __ASM_MTE_H #define __ASM_MTE_H -#define MTE_GRANULE_SIZE UL(16) -#define MTE_GRANULE_MASK (~(MTE_GRANULE_SIZE - 1)) -#define MTE_TAG_SHIFT 56 -#define MTE_TAG_SIZE 4 +#include +#include + +#define __MTE_PREAMBLE ARM64_ASM_PREAMBLE ".arch_extension memtag\n" #ifndef __ASSEMBLY__ +#include #include +#include #include @@ -45,7 +47,9 @@ long get_mte_ctrl(struct task_struct *ta int mte_ptrace_copy_tags(struct task_struct *child, long request, unsigned long addr, unsigned long data); -#else +void mte_assign_mem_tag_range(void *addr, size_t size); + +#else /* CONFIG_ARM64_MTE */ /* unused if !CONFIG_ARM64_MTE, silence the compiler */ #define PG_mte_tagged 0 @@ -80,7 +84,11 @@ static inline int mte_ptrace_copy_tags(s return -EIO; } -#endif +static inline void mte_assign_mem_tag_range(void *addr, size_t size) +{ +} + +#endif /* CONFIG_ARM64_MTE */ #endif /* __ASSEMBLY__ */ #endif /* __ASM_MTE_H */ --- /dev/null +++ a/arch/arm64/include/asm/mte-kasan.h @@ -0,0 +1,56 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2020 ARM Ltd. + */ +#ifndef __ASM_MTE_KASAN_H +#define __ASM_MTE_KASAN_H + +#include + +#ifndef __ASSEMBLY__ + +#include + +/* + * The functions below are meant to be used only for the + * KASAN_HW_TAGS interface defined in asm/memory.h. + */ +#ifdef CONFIG_ARM64_MTE + +static inline u8 mte_get_ptr_tag(void *ptr) +{ + /* Note: The format of KASAN tags is 0xF */ + u8 tag = 0xF0 | (u8)(((u64)(ptr)) >> MTE_TAG_SHIFT); + + return tag; +} + +u8 mte_get_mem_tag(void *addr); +u8 mte_get_random_tag(void); +void *mte_set_mem_tag_range(void *addr, size_t size, u8 tag); + +#else /* CONFIG_ARM64_MTE */ + +static inline u8 mte_get_ptr_tag(void *ptr) +{ + return 0xFF; +} + +static inline u8 mte_get_mem_tag(void *addr) +{ + return 0xFF; +} +static inline u8 mte_get_random_tag(void) +{ + return 0xFF; +} +static inline void *mte_set_mem_tag_range(void *addr, size_t size, u8 tag) +{ + return addr; +} + +#endif /* CONFIG_ARM64_MTE */ + +#endif /* __ASSEMBLY__ */ + +#endif /* __ASM_MTE_KASAN_H */ --- a/arch/arm64/kernel/mte.c~arm64-mte-add-in-kernel-mte-helpers +++ a/arch/arm64/kernel/mte.c @@ -13,10 +13,13 @@ #include #include #include +#include #include +#include #include #include +#include #include #include @@ -72,6 +75,51 @@ int memcmp_pages(struct page *page1, str return ret; } +u8 mte_get_mem_tag(void *addr) +{ + if (!system_supports_mte()) + return 0xFF; + + asm(__MTE_PREAMBLE "ldg %0, [%0]" + : "+r" (addr)); + + return mte_get_ptr_tag(addr); +} + +u8 mte_get_random_tag(void) +{ + void *addr; + + if (!system_supports_mte()) + return 0xFF; + + asm(__MTE_PREAMBLE "irg %0, %0" + : "+r" (addr)); + + return mte_get_ptr_tag(addr); +} + +void *mte_set_mem_tag_range(void *addr, size_t size, u8 tag) +{ + void *ptr = addr; + + if ((!system_supports_mte()) || (size == 0)) + return addr; + + /* Make sure that size is MTE granule aligned. */ + WARN_ON(size & (MTE_GRANULE_SIZE - 1)); + + /* Make sure that the address is MTE granule aligned. */ + WARN_ON((u64)addr & (MTE_GRANULE_SIZE - 1)); + + tag = 0xF0 | tag; + ptr = (void *)__tag_set(ptr, tag); + + mte_assign_mem_tag_range(ptr, size); + + return ptr; +} + static void update_sctlr_el1_tcf0(u64 tcf0) { /* ISB required for the kernel uaccess routines */ --- a/arch/arm64/lib/mte.S~arm64-mte-add-in-kernel-mte-helpers +++ a/arch/arm64/lib/mte.S @@ -149,3 +149,19 @@ SYM_FUNC_START(mte_restore_page_tags) ret SYM_FUNC_END(mte_restore_page_tags) + +/* + * Assign allocation tags for a region of memory based on the pointer tag + * x0 - source pointer + * x1 - size + * + * Note: The address must be non-NULL and MTE_GRANULE_SIZE aligned and + * size must be non-zero and MTE_GRANULE_SIZE aligned. + */ +SYM_FUNC_START(mte_assign_mem_tag_range) +1: stg x0, [x0] + add x0, x0, #MTE_GRANULE_SIZE + subs x1, x1, #MTE_GRANULE_SIZE + b.gt 1b + ret +SYM_FUNC_END(mte_assign_mem_tag_range)