fa7a7d185e
[ Upstream commit 3f105a742725a1b78766a55169f1d827732e62b8 ]
The EFI page table is initially created as a copy of the kernel page table.
With VMAP_STACK enabled, kernel stacks are allocated in the vmalloc area:
if the stack is allocated in a new PGD (one that was not present at the
moment of the efi page table creation or not synced in a previous vmalloc
fault), the kernel will take a trap when switching to the efi page table
when the vmalloc kernel stack is accessed, resulting in a kernel panic.
Fix that by updating the efi kernel mappings before switching to the efi
page table.
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Fixes: b91540d52a ("RISC-V: Add EFI runtime services")
Tested-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Link: https://lore.kernel.org/r/20221121133303.1782246-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
75 lines
1.8 KiB
C
75 lines
1.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Copyright (C) 2009 Chen Liqin <liqin.chen@sunplusct.com>
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* Copyright (C) 2012 Regents of the University of California
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*/
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#ifndef _ASM_RISCV_PGALLOC_H
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#define _ASM_RISCV_PGALLOC_H
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#include <linux/mm.h>
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#include <asm/tlb.h>
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#ifdef CONFIG_MMU
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#include <asm-generic/pgalloc.h>
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static inline void pmd_populate_kernel(struct mm_struct *mm,
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pmd_t *pmd, pte_t *pte)
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{
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unsigned long pfn = virt_to_pfn(pte);
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set_pmd(pmd, __pmd((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE));
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}
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static inline void pmd_populate(struct mm_struct *mm,
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pmd_t *pmd, pgtable_t pte)
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{
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unsigned long pfn = virt_to_pfn(page_address(pte));
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set_pmd(pmd, __pmd((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE));
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}
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#ifndef __PAGETABLE_PMD_FOLDED
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static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
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{
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unsigned long pfn = virt_to_pfn(pmd);
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set_pud(pud, __pud((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE));
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}
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#endif /* __PAGETABLE_PMD_FOLDED */
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static inline void sync_kernel_mappings(pgd_t *pgd)
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{
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memcpy(pgd + USER_PTRS_PER_PGD,
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init_mm.pgd + USER_PTRS_PER_PGD,
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(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
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}
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static inline pgd_t *pgd_alloc(struct mm_struct *mm)
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{
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pgd_t *pgd;
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pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
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if (likely(pgd != NULL)) {
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memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
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/* Copy kernel mappings */
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sync_kernel_mappings(pgd);
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}
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return pgd;
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}
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#ifndef __PAGETABLE_PMD_FOLDED
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#define __pmd_free_tlb(tlb, pmd, addr) pmd_free((tlb)->mm, pmd)
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#endif /* __PAGETABLE_PMD_FOLDED */
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#define __pte_free_tlb(tlb, pte, buf) \
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do { \
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pgtable_pte_page_dtor(pte); \
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tlb_remove_page((tlb), pte); \
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} while (0)
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#endif /* CONFIG_MMU */
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#endif /* _ASM_RISCV_PGALLOC_H */
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