From patchwork Mon Aug 24 18:27:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Catalin Marinas X-Patchwork-Id: 11733961 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6E98613B1 for ; Mon, 24 Aug 2020 18:28:38 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3286D206BE for ; Mon, 24 Aug 2020 18:28:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3286D206BE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 21BA38E0006; Mon, 24 Aug 2020 14:28:35 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 1CCAF8E0003; Mon, 24 Aug 2020 14:28:35 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0BCF18E0006; Mon, 24 Aug 2020 14:28:34 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0139.hostedemail.com [216.40.44.139]) by kanga.kvack.org (Postfix) with ESMTP id DAD528E0003 for ; Mon, 24 Aug 2020 14:28:34 -0400 (EDT) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 87C2F180AD820 for ; Mon, 24 Aug 2020 18:28:34 +0000 (UTC) X-FDA: 77186297748.21.toy08_4d1860a27055 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin21.hostedemail.com (Postfix) with ESMTP id 52791180442C2 for ; Mon, 24 Aug 2020 18:28:34 +0000 (UTC) X-Spam-Summary: 1,0,0,085bea7ccc44a313,d41d8cd98f00b204,cmainas@kernel.org,,RULES_HIT:2:41:355:379:541:800:960:973:988:989:1260:1311:1314:1345:1359:1431:1437:1515:1535:1605:1730:1747:1777:1792:1981:2194:2198:2199:2200:2393:2553:2559:2562:2693:2892:2895:2901:3138:3139:3140:3141:3142:3865:3866:3867:3868:3870:3871:3872:3874:4051:4120:4250:4321:4605:4641:5007:6119:6261:7903:7904:8660:8957:10004:11026:11232:11473:11657:11658:11914:12043:12291:12295:12296:12297:12438:12517:12519:12555:12683:12986:13138:13141:13148:13161:13180:13184:13229:13230:13231:13894:13972:14394:21080:21220:21230:21433:21451:21627:21795:21939:21990:30051:30054:30055:30056:30070:30075:30079:30090,0,RBL:198.145.29.99:@kernel.org:.lbl8.mailshell.net-64.100.201.201 62.2.0.100;04y8ddpynscmw36sgu69kwuq43aydocfwqjrhxhqus644sqkksboms7gd3jupfd.1fwwtfob8myskur8tp4tw5dwzm49od9dse69xnpdre5u9gmbwbup34qobgta63c.4-lbl8.mailshell.net-223.238.255.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SP F:fp,MSB X-HE-Tag: toy08_4d1860a27055 X-Filterd-Recvd-Size: 9485 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf06.hostedemail.com (Postfix) with ESMTP for ; Mon, 24 Aug 2020 18:28:33 +0000 (UTC) Received: from localhost.localdomain (unknown [95.146.230.145]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1DD052075B; Mon, 24 Aug 2020 18:28:30 +0000 (UTC) From: Catalin Marinas To: linux-arm-kernel@lists.infradead.org Cc: linux-mm@kvack.org, linux-arch@vger.kernel.org, Will Deacon , Dave P Martin , Vincenzo Frascino , Szabolcs Nagy , Kevin Brodsky , Andrey Konovalov , Peter Collingbourne , Andrew Morton Subject: [PATCH v8 13/28] arm64: mte: Add PROT_MTE support to mmap() and mprotect() Date: Mon, 24 Aug 2020 19:27:43 +0100 Message-Id: <20200824182758.27267-14-catalin.marinas@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200824182758.27267-1-catalin.marinas@arm.com> References: <20200824182758.27267-1-catalin.marinas@arm.com> MIME-Version: 1.0 X-Rspamd-Queue-Id: 52791180442C2 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 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: To enable tagging on a memory range, the user must explicitly opt in via a new PROT_MTE flag passed to mmap() or mprotect(). Since this is a new memory type in the AttrIndx field of a pte, simplify the or'ing of these bits over the protection_map[] attributes by making MT_NORMAL index 0. There are two conditions for arch_vm_get_page_prot() to return the MT_NORMAL_TAGGED memory type: (1) the user requested it via PROT_MTE, registered as VM_MTE in the vm_flags, and (2) the vma supports MTE, decided during the mmap() call (only) and registered as VM_MTE_ALLOWED. arch_calc_vm_prot_bits() is responsible for registering the user request as VM_MTE. The newly introduced arch_calc_vm_flag_bits() sets VM_MTE_ALLOWED if the mapping is MAP_ANONYMOUS. An MTE-capable filesystem (RAM-based) may be able to set VM_MTE_ALLOWED during its mmap() file ops call. In addition, update VM_DATA_DEFAULT_FLAGS to allow mprotect(PROT_MTE) on stack or brk area. The Linux mmap() syscall currently ignores unknown PROT_* flags. In the presence of MTE, an mmap(PROT_MTE) on a file which does not support MTE will not report an error and the memory will not be mapped as Normal Tagged. For consistency, mprotect(PROT_MTE) will not report an error either if the memory range does not support MTE. Two subsequent patches in the series will propose tightening of this behaviour. Co-developed-by: Vincenzo Frascino Signed-off-by: Vincenzo Frascino Signed-off-by: Catalin Marinas Cc: Will Deacon --- Notes: v2: - Add VM_MTE_ALLOWED to show_smap_vma_flags(). arch/arm64/include/asm/memory.h | 18 +++++++----- arch/arm64/include/asm/mman.h | 44 ++++++++++++++++++++++++++++-- arch/arm64/include/asm/page.h | 2 +- arch/arm64/include/asm/pgtable.h | 7 ++++- arch/arm64/include/uapi/asm/mman.h | 1 + fs/proc/task_mmu.c | 4 +++ include/linux/mm.h | 8 ++++++ 7 files changed, 72 insertions(+), 12 deletions(-) diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 1e0a78266410..e424fc3a68cb 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -126,14 +126,18 @@ /* * Memory types available. + * + * IMPORTANT: MT_NORMAL must be index 0 since vm_get_page_prot() may 'or' in + * the MT_NORMAL_TAGGED memory type for PROT_MTE mappings. Note + * that protection_map[] only contains MT_NORMAL attributes. */ -#define MT_DEVICE_nGnRnE 0 -#define MT_DEVICE_nGnRE 1 -#define MT_DEVICE_GRE 2 -#define MT_NORMAL_NC 3 -#define MT_NORMAL 4 -#define MT_NORMAL_WT 5 -#define MT_NORMAL_TAGGED 6 +#define MT_NORMAL 0 +#define MT_NORMAL_TAGGED 1 +#define MT_NORMAL_NC 2 +#define MT_NORMAL_WT 3 +#define MT_DEVICE_nGnRnE 4 +#define MT_DEVICE_nGnRE 5 +#define MT_DEVICE_GRE 6 /* * Memory types for Stage-2 translation diff --git a/arch/arm64/include/asm/mman.h b/arch/arm64/include/asm/mman.h index 081ec8de9ea6..b01051be7750 100644 --- a/arch/arm64/include/asm/mman.h +++ b/arch/arm64/include/asm/mman.h @@ -9,16 +9,51 @@ static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot, unsigned long pkey __always_unused) { + unsigned long ret = 0; + if (system_supports_bti() && (prot & PROT_BTI)) - return VM_ARM64_BTI; + ret |= VM_ARM64_BTI; - return 0; + if (system_supports_mte() && (prot & PROT_MTE)) + ret |= VM_MTE; + + return ret; } #define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey) +static inline unsigned long arch_calc_vm_flag_bits(unsigned long flags) +{ + /* + * Only allow MTE on anonymous mappings as these are guaranteed to be + * backed by tags-capable memory. The vm_flags may be overridden by a + * filesystem supporting MTE (RAM-based). + */ + if (system_supports_mte() && (flags & MAP_ANONYMOUS)) + return VM_MTE_ALLOWED; + + return 0; +} +#define arch_calc_vm_flag_bits(flags) arch_calc_vm_flag_bits(flags) + static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags) { - return (vm_flags & VM_ARM64_BTI) ? __pgprot(PTE_GP) : __pgprot(0); + pteval_t prot = 0; + + if (vm_flags & VM_ARM64_BTI) + prot |= PTE_GP; + + /* + * There are two conditions required for returning a Normal Tagged + * memory type: (1) the user requested it via PROT_MTE passed to + * mmap() or mprotect() and (2) the corresponding vma supports MTE. We + * register (1) as VM_MTE in the vma->vm_flags and (2) as + * VM_MTE_ALLOWED. Note that the latter can only be set during the + * mmap() call since mprotect() does not accept MAP_* flags. + */ + if ((vm_flags & VM_MTE) && (vm_flags & VM_MTE_ALLOWED)) + prot |= PTE_ATTRINDX(MT_NORMAL_TAGGED); + + return __pgprot(prot); } #define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags) @@ -30,6 +65,9 @@ static inline bool arch_validate_prot(unsigned long prot, if (system_supports_bti()) supported |= PROT_BTI; + if (system_supports_mte()) + supported |= PROT_MTE; + return (prot & ~supported) == 0; } #define arch_validate_prot(prot, addr) arch_validate_prot(prot, addr) diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h index d918cb1d83a6..012cffc574e8 100644 --- a/arch/arm64/include/asm/page.h +++ b/arch/arm64/include/asm/page.h @@ -43,7 +43,7 @@ extern int pfn_valid(unsigned long); #endif /* !__ASSEMBLY__ */ -#define VM_DATA_DEFAULT_FLAGS VM_DATA_FLAGS_TSK_EXEC +#define VM_DATA_DEFAULT_FLAGS (VM_DATA_FLAGS_TSK_EXEC | VM_MTE_ALLOWED) #include diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 0a205a8e91b2..057c40b6f5e0 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -681,8 +681,13 @@ static inline unsigned long p4d_page_vaddr(p4d_t p4d) static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) { + /* + * Normal and Normal-Tagged are two different memory types and indices + * in MAIR_EL1. The mask below has to include PTE_ATTRINDX_MASK. + */ const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY | - PTE_PROT_NONE | PTE_VALID | PTE_WRITE | PTE_GP; + PTE_PROT_NONE | PTE_VALID | PTE_WRITE | PTE_GP | + PTE_ATTRINDX_MASK; /* preserve the hardware dirty information */ if (pte_hw_dirty(pte)) pte = pte_mkdirty(pte); diff --git a/arch/arm64/include/uapi/asm/mman.h b/arch/arm64/include/uapi/asm/mman.h index 6fdd71eb644f..1e6482a838e1 100644 --- a/arch/arm64/include/uapi/asm/mman.h +++ b/arch/arm64/include/uapi/asm/mman.h @@ -5,5 +5,6 @@ #include #define PROT_BTI 0x10 /* BTI guarded page */ +#define PROT_MTE 0x20 /* Normal Tagged mapping */ #endif /* ! _UAPI__ASM_MMAN_H */ diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 5066b0251ed8..35172a91148e 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -653,6 +653,10 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) [ilog2(VM_MERGEABLE)] = "mg", [ilog2(VM_UFFD_MISSING)]= "um", [ilog2(VM_UFFD_WP)] = "uw", +#ifdef CONFIG_ARM64_MTE + [ilog2(VM_MTE)] = "mt", + [ilog2(VM_MTE_ALLOWED)] = "", +#endif #ifdef CONFIG_ARCH_HAS_PKEYS /* These come out via ProtectionKey: */ [ilog2(VM_PKEY_BIT0)] = "", diff --git a/include/linux/mm.h b/include/linux/mm.h index 1983e08f5906..8f4fcee185dd 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -335,6 +335,14 @@ extern unsigned int kobjsize(const void *objp); # define VM_MAPPED_COPY VM_ARCH_1 /* T if mapped copy of data (nommu mmap) */ #endif +#if defined(CONFIG_ARM64_MTE) +# define VM_MTE VM_HIGH_ARCH_0 /* Use Tagged memory for access control */ +# define VM_MTE_ALLOWED VM_HIGH_ARCH_1 /* Tagged memory permitted */ +#else +# define VM_MTE VM_NONE +# define VM_MTE_ALLOWED VM_NONE +#endif + #ifndef VM_GROWSUP # define VM_GROWSUP VM_NONE #endif