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b89d82ef01
A side effect of commit c55191e96c
("arm64: mm: apply r/o permissions
of VM areas to its linear alias as well") is that the linear map is
created with page granularity, which means that transitioning the early
page table from global to non-global mappings when enabling kpti can
take a significant amount of time during boot.
Given that most CPU implementations do not require kpti, this mainly
impacts KASLR builds where kpti is forcefully enabled. However, in these
situations we know early on that non-global mappings are required and
can avoid the use of global mappings from the beginning. The only gotcha
is Cavium erratum #27456, which we must detect based on the MIDR value
of the boot CPU.
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reported-by: John Garry <john.garry@huawei.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
121 lines
4.8 KiB
C
121 lines
4.8 KiB
C
/*
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* Copyright (C) 2016 ARM Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef __ASM_PGTABLE_PROT_H
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#define __ASM_PGTABLE_PROT_H
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#include <asm/memory.h>
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#include <asm/pgtable-hwdef.h>
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#include <linux/const.h>
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/*
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* Software defined PTE bits definition.
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*/
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#define PTE_VALID (_AT(pteval_t, 1) << 0)
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#define PTE_WRITE (PTE_DBM) /* same as DBM (51) */
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#define PTE_DIRTY (_AT(pteval_t, 1) << 55)
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#define PTE_SPECIAL (_AT(pteval_t, 1) << 56)
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#define PTE_PROT_NONE (_AT(pteval_t, 1) << 58) /* only when !PTE_VALID */
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#ifndef __ASSEMBLY__
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#include <asm/pgtable-types.h>
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#define _PROT_DEFAULT (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED)
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#define _PROT_SECT_DEFAULT (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S)
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#define PTE_MAYBE_NG (arm64_kernel_use_ng_mappings() ? PTE_NG : 0)
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#define PMD_MAYBE_NG (arm64_kernel_use_ng_mappings() ? PMD_SECT_NG : 0)
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#define PROT_DEFAULT (_PROT_DEFAULT | PTE_MAYBE_NG)
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#define PROT_SECT_DEFAULT (_PROT_SECT_DEFAULT | PMD_MAYBE_NG)
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#define PROT_DEVICE_nGnRnE (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_ATTRINDX(MT_DEVICE_nGnRnE))
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#define PROT_DEVICE_nGnRE (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_ATTRINDX(MT_DEVICE_nGnRE))
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#define PROT_NORMAL_NC (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_ATTRINDX(MT_NORMAL_NC))
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#define PROT_NORMAL_WT (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_ATTRINDX(MT_NORMAL_WT))
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#define PROT_NORMAL (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_ATTRINDX(MT_NORMAL))
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#define PROT_SECT_DEVICE_nGnRE (PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PMD_ATTRINDX(MT_DEVICE_nGnRE))
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#define PROT_SECT_NORMAL (PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PMD_ATTRINDX(MT_NORMAL))
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#define PROT_SECT_NORMAL_EXEC (PROT_SECT_DEFAULT | PMD_SECT_UXN | PMD_ATTRINDX(MT_NORMAL))
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#define _PAGE_DEFAULT (_PROT_DEFAULT | PTE_ATTRINDX(MT_NORMAL))
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#define _HYP_PAGE_DEFAULT _PAGE_DEFAULT
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#define PAGE_KERNEL __pgprot(PROT_NORMAL)
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#define PAGE_KERNEL_RO __pgprot((PROT_NORMAL & ~PTE_WRITE) | PTE_RDONLY)
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#define PAGE_KERNEL_ROX __pgprot((PROT_NORMAL & ~(PTE_WRITE | PTE_PXN)) | PTE_RDONLY)
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#define PAGE_KERNEL_EXEC __pgprot(PROT_NORMAL & ~PTE_PXN)
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#define PAGE_KERNEL_EXEC_CONT __pgprot((PROT_NORMAL & ~PTE_PXN) | PTE_CONT)
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#define PAGE_HYP __pgprot(_HYP_PAGE_DEFAULT | PTE_HYP | PTE_HYP_XN)
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#define PAGE_HYP_EXEC __pgprot(_HYP_PAGE_DEFAULT | PTE_HYP | PTE_RDONLY)
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#define PAGE_HYP_RO __pgprot(_HYP_PAGE_DEFAULT | PTE_HYP | PTE_RDONLY | PTE_HYP_XN)
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#define PAGE_HYP_DEVICE __pgprot(PROT_DEVICE_nGnRE | PTE_HYP)
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#define PAGE_S2_MEMATTR(attr) \
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({ \
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u64 __val; \
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if (cpus_have_const_cap(ARM64_HAS_STAGE2_FWB)) \
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__val = PTE_S2_MEMATTR(MT_S2_FWB_ ## attr); \
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else \
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__val = PTE_S2_MEMATTR(MT_S2_ ## attr); \
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__val; \
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})
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#define PAGE_S2_XN \
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({ \
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u64 __val; \
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if (cpus_have_const_cap(ARM64_HAS_CACHE_DIC)) \
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__val = 0; \
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else \
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__val = PTE_S2_XN; \
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__val; \
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})
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#define PAGE_S2 __pgprot(_PROT_DEFAULT | PAGE_S2_MEMATTR(NORMAL) | PTE_S2_RDONLY | PAGE_S2_XN)
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#define PAGE_S2_DEVICE __pgprot(_PROT_DEFAULT | PAGE_S2_MEMATTR(DEVICE_nGnRE) | PTE_S2_RDONLY | PAGE_S2_XN)
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#define PAGE_NONE __pgprot(((_PAGE_DEFAULT) & ~PTE_VALID) | PTE_PROT_NONE | PTE_RDONLY | PTE_NG | PTE_PXN | PTE_UXN)
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#define PAGE_SHARED __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN | PTE_WRITE)
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#define PAGE_SHARED_EXEC __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_WRITE)
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#define PAGE_READONLY __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_RDONLY | PTE_NG | PTE_PXN | PTE_UXN)
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#define PAGE_READONLY_EXEC __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_RDONLY | PTE_NG | PTE_PXN)
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#define PAGE_EXECONLY __pgprot(_PAGE_DEFAULT | PTE_RDONLY | PTE_NG | PTE_PXN)
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#define __P000 PAGE_NONE
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#define __P001 PAGE_READONLY
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#define __P010 PAGE_READONLY
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#define __P011 PAGE_READONLY
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#define __P100 PAGE_EXECONLY
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#define __P101 PAGE_READONLY_EXEC
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#define __P110 PAGE_READONLY_EXEC
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#define __P111 PAGE_READONLY_EXEC
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#define __S000 PAGE_NONE
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#define __S001 PAGE_READONLY
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#define __S010 PAGE_SHARED
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#define __S011 PAGE_SHARED
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#define __S100 PAGE_EXECONLY
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#define __S101 PAGE_READONLY_EXEC
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#define __S110 PAGE_SHARED_EXEC
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#define __S111 PAGE_SHARED_EXEC
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#endif /* __ASSEMBLY__ */
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#endif /* __ASM_PGTABLE_PROT_H */
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