Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753096AbdGEV3X (ORCPT ); Wed, 5 Jul 2017 17:29:23 -0400 Received: from mail-qk0-f195.google.com ([209.85.220.195]:36519 "EHLO mail-qk0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752887AbdGEVXO (ORCPT ); Wed, 5 Jul 2017 17:23:14 -0400 From: Ram Pai To: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, khandual@linux.vnet.ibm.com, aneesh.kumar@linux.vnet.ibm.com, bsingharora@gmail.com, dave.hansen@intel.com, hbabu@us.ibm.com, linuxram@us.ibm.com, arnd@arndb.de, akpm@linux-foundation.org, corbet@lwn.net, mingo@redhat.com Subject: [RFC v5 16/38] powerpc: implementation for arch_set_user_pkey_access() Date: Wed, 5 Jul 2017 14:21:53 -0700 Message-Id: <1499289735-14220-17-git-send-email-linuxram@us.ibm.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1499289735-14220-1-git-send-email-linuxram@us.ibm.com> References: <1499289735-14220-1-git-send-email-linuxram@us.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4224 Lines: 127 This patch provides the detailed implementation for a user to allocate a key and enable it in the hardware. It provides the plumbing, but it cannot be used yet till the system call is implemented. The next patch will do so. Signed-off-by: Ram Pai --- arch/powerpc/include/asm/pkeys.h | 8 ++++- arch/powerpc/mm/Makefile | 1 + arch/powerpc/mm/pkeys.c | 66 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 74 insertions(+), 1 deletions(-) create mode 100644 arch/powerpc/mm/pkeys.c diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h index 9345767..1495342 100644 --- a/arch/powerpc/include/asm/pkeys.h +++ b/arch/powerpc/include/asm/pkeys.h @@ -2,6 +2,10 @@ #define _ASM_PPC64_PKEYS_H #define arch_max_pkey() 32 +#define AMR_AD_BIT 0x1UL +#define AMR_WD_BIT 0x2UL +#define IAMR_EX_BIT 0x1UL +#define AMR_BITS_PER_PKEY 2 #define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | \ VM_PKEY_BIT3 | VM_PKEY_BIT4) /* @@ -93,10 +97,12 @@ static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma, return 0; } +extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, + unsigned long init_val); static inline int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, unsigned long init_val) { - return 0; + return __arch_set_user_pkey_access(tsk, pkey, init_val); } static inline void pkey_mm_init(struct mm_struct *mm) diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile index 7414034..8cc2ff1 100644 --- a/arch/powerpc/mm/Makefile +++ b/arch/powerpc/mm/Makefile @@ -45,3 +45,4 @@ obj-$(CONFIG_PPC_COPRO_BASE) += copro_fault.o obj-$(CONFIG_SPAPR_TCE_IOMMU) += mmu_context_iommu.o obj-$(CONFIG_PPC_PTDUMP) += dump_linuxpagetables.o obj-$(CONFIG_PPC_HTDUMP) += dump_hashpagetable.o +obj-$(CONFIG_PPC64_MEMORY_PROTECTION_KEYS) += pkeys.o diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c new file mode 100644 index 0000000..d3ba167 --- /dev/null +++ b/arch/powerpc/mm/pkeys.c @@ -0,0 +1,66 @@ +/* + * PowerPC Memory Protection Keys management + * Copyright (c) 2015, Intel Corporation. + * Copyright (c) 2017, IBM Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + */ +#include /* PKEY_* */ +#include + +/* + * set the access right in AMR IAMR and UAMOR register + * for @pkey to that specified in @init_val. + */ +int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, + unsigned long init_val) +{ + u64 old_amr, old_uamor, old_iamr; + int pkey_shift = (arch_max_pkey()-pkey-1) * AMR_BITS_PER_PKEY; + u64 new_amr_bits = 0x0ul; + u64 new_iamr_bits = 0x0ul; + u64 new_uamor_bits = 0x3ul; + + /* Set the bits we need in AMR: */ + if (init_val & PKEY_DISABLE_ACCESS) + new_amr_bits |= AMR_AD_BIT | AMR_WD_BIT; + if (init_val & PKEY_DISABLE_WRITE) + new_amr_bits |= AMR_WD_BIT; + + /* + * By default execute is disabled. + * To enable execute, PKEY_ENABLE_EXECUTE + * needs to be specified. + */ + if ((init_val & PKEY_DISABLE_EXECUTE)) + new_iamr_bits |= IAMR_EX_BIT; + + /* Shift the bits in to the correct place in AMR for pkey: */ + new_amr_bits <<= pkey_shift; + new_iamr_bits <<= pkey_shift; + new_uamor_bits <<= pkey_shift; + + /* Get old AMR and mask off any old bits in place: */ + old_amr = read_amr(); + old_amr &= ~((u64)(AMR_AD_BIT|AMR_WD_BIT) << pkey_shift); + + old_iamr = read_iamr(); + old_iamr &= ~(0x3ul << pkey_shift); + + old_uamor = read_uamor(); + old_uamor &= ~(0x3ul << pkey_shift); + + /* Write old part along with new part: */ + write_amr(old_amr | new_amr_bits); + write_iamr(old_iamr | new_iamr_bits); + write_uamor(old_uamor | new_uamor_bits); + + return 0; +} -- 1.7.1