From 92e3da3cf193fd27996909956c12a23c0333da44 Mon Sep 17 00:00:00 2001 From: Ram Pai Date: Thu, 18 Jan 2018 17:50:24 -0800 Subject: [PATCH] powerpc: initial pkey plumbing Basic plumbing to initialize the pkey system. Nothing is enabled yet. A later patch will enable it once all the infrastructure is in place. Signed-off-by: Ram Pai [mpe: Rework copyrights to use SPDX tags] Signed-off-by: Michael Ellerman --- arch/powerpc/Kconfig | 15 ++++++++++ arch/powerpc/include/asm/mmu_context.h | 1 + arch/powerpc/include/asm/pkeys.h | 51 ++++++++++++++++++++++++++++++++++ arch/powerpc/mm/Makefile | 1 + arch/powerpc/mm/hash_utils_64.c | 1 + arch/powerpc/mm/pkeys.c | 29 +++++++++++++++++++ 6 files changed, 98 insertions(+) create mode 100644 arch/powerpc/include/asm/pkeys.h create mode 100644 arch/powerpc/mm/pkeys.c diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index c51e6ce42e7a..c9660a18c093 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -867,6 +867,21 @@ config SECCOMP If unsure, say Y. Only embedded should say N here. +config PPC_MEM_KEYS + prompt "PowerPC Memory Protection Keys" + def_bool y + depends on PPC_BOOK3S_64 + select ARCH_USES_HIGH_VMA_FLAGS + select ARCH_HAS_PKEYS + help + Memory Protection Keys provides a mechanism for enforcing + page-based protections, but without requiring modification of the + page tables when an application changes protection domains. + + For details, see Documentation/vm/protection-keys.txt + + If unsure, say y. + endmenu config ISA_DMA_API diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h index 6177d43f0ce8..fb5e6a3ce127 100644 --- a/arch/powerpc/include/asm/mmu_context.h +++ b/arch/powerpc/include/asm/mmu_context.h @@ -192,5 +192,6 @@ static inline bool arch_vma_access_permitted(struct vm_area_struct *vma, /* by default, allow everything */ return true; } + #endif /* __KERNEL__ */ #endif /* __ASM_POWERPC_MMU_CONTEXT_H */ diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h new file mode 100644 index 000000000000..dadea7d4324d --- /dev/null +++ b/arch/powerpc/include/asm/pkeys.h @@ -0,0 +1,51 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * PowerPC Memory Protection Keys management + * + * Copyright 2017, Ram Pai, IBM Corporation. + */ + +#ifndef _ASM_POWERPC_KEYS_H +#define _ASM_POWERPC_KEYS_H + +#include + +DECLARE_STATIC_KEY_TRUE(pkey_disabled); +#define ARCH_VM_PKEY_FLAGS 0 + +static inline bool mm_pkey_is_allocated(struct mm_struct *mm, int pkey) +{ + return false; +} + +static inline int mm_pkey_alloc(struct mm_struct *mm) +{ + return -1; +} + +static inline int mm_pkey_free(struct mm_struct *mm, int pkey) +{ + return -EINVAL; +} + +/* + * Try to dedicate one of the protection keys to be used as an + * execute-only protection key. + */ +static inline int execute_only_pkey(struct mm_struct *mm) +{ + return 0; +} + +static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma, + int prot, int pkey) +{ + return 0; +} + +static inline int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, + unsigned long init_val) +{ + return 0; +} +#endif /*_ASM_POWERPC_KEYS_H */ diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile index 8d271bfe2d94..f06f3577d8d1 100644 --- a/arch/powerpc/mm/Makefile +++ b/arch/powerpc/mm/Makefile @@ -44,3 +44,4 @@ 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_PPC_MEM_KEYS) += pkeys.o diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index 64e704eefad1..8cd31ea9b243 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -36,6 +36,7 @@ #include #include #include +#include #include #include diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c new file mode 100644 index 000000000000..a11afba584b9 --- /dev/null +++ b/arch/powerpc/mm/pkeys.c @@ -0,0 +1,29 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * PowerPC Memory Protection Keys management + * + * Copyright 2017, Ram Pai, IBM Corporation. + */ + +#include + +DEFINE_STATIC_KEY_TRUE(pkey_disabled); +bool pkey_execute_disable_supported; + +int pkey_initialize(void) +{ + /* + * Disable the pkey system till everything is in place. A subsequent + * patch will enable it. + */ + static_branch_enable(&pkey_disabled); + + /* + * Disable execute_disable support for now. A subsequent patch will + * enable it. + */ + pkey_execute_disable_supported = false; + return 0; +} + +arch_initcall(pkey_initialize); -- 2.11.0