| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Based on arch/arm/mm/mmu.c |
| * |
| * Copyright (C) 1995-2005 Russell King |
| * Copyright (C) 2012 ARM Ltd. |
| */ |
| |
| #include <linux/cache.h> |
| #include <linux/export.h> |
| #include <linux/kernel.h> |
| #include <linux/errno.h> |
| #include <linux/init.h> |
| #include <linux/ioport.h> |
| #include <linux/kexec.h> |
| #include <linux/libfdt.h> |
| #include <linux/mman.h> |
| #include <linux/nodemask.h> |
| #include <linux/memblock.h> |
| #include <linux/memremap.h> |
| #include <linux/memory.h> |
| #include <linux/fs.h> |
| #include <linux/io.h> |
| #include <linux/mm.h> |
| #include <linux/vmalloc.h> |
| #include <linux/set_memory.h> |
| #include <linux/kfence.h> |
| |
| #include <asm/barrier.h> |
| #include <asm/cputype.h> |
| #include <asm/fixmap.h> |
| #include <asm/kasan.h> |
| #include <asm/kernel-pgtable.h> |
| #include <asm/sections.h> |
| #include <asm/setup.h> |
| #include <linux/sizes.h> |
| #include <asm/tlb.h> |
| #include <asm/mmu_context.h> |
| #include <asm/ptdump.h> |
| #include <asm/tlbflush.h> |
| #include <asm/pgalloc.h> |
| #include <asm/kfence.h> |
| |
| #define NO_BLOCK_MAPPINGS BIT(0) |
| #define NO_CONT_MAPPINGS BIT(1) |
| #define NO_EXEC_MAPPINGS BIT(2) /* assumes FEAT_HPDS is not used */ |
| |
| int idmap_t0sz __ro_after_init; |
| |
| #if VA_BITS > 48 |
| u64 vabits_actual __ro_after_init = VA_BITS_MIN; |
| EXPORT_SYMBOL(vabits_actual); |
| #endif |
| |
| u64 kimage_vaddr __ro_after_init = (u64)&_text; |
| EXPORT_SYMBOL(kimage_vaddr); |
| |
| u64 kimage_voffset __ro_after_init; |
| EXPORT_SYMBOL(kimage_voffset); |
| |
| u32 __boot_cpu_mode[] = { BOOT_CPU_MODE_EL2, BOOT_CPU_MODE_EL1 }; |
| |
| /* |
| * The booting CPU updates the failed status @__early_cpu_boot_status, |
| * with MMU turned off. |
| */ |
| long __section(".mmuoff.data.write") __early_cpu_boot_status; |
| |
| /* |
| * Empty_zero_page is a special page that is used for zero-initialized data |
| * and COW. |
| */ |
| unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss; |
| EXPORT_SYMBOL(empty_zero_page); |
| |
| static DEFINE_SPINLOCK(swapper_pgdir_lock); |
| static DEFINE_MUTEX(fixmap_lock); |
| |
| void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd) |
| { |
| pgd_t *fixmap_pgdp; |
| |
| spin_lock(&swapper_pgdir_lock); |
| fixmap_pgdp = pgd_set_fixmap(__pa_symbol(pgdp)); |
| WRITE_ONCE(*fixmap_pgdp, pgd); |
| /* |
| * We need dsb(ishst) here to ensure the page-table-walker sees |
| * our new entry before set_p?d() returns. The fixmap's |
| * flush_tlb_kernel_range() via clear_fixmap() does this for us. |
| */ |
| pgd_clear_fixmap(); |
| spin_unlock(&swapper_pgdir_lock); |
| } |
| |
| pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, |
| unsigned long size, pgprot_t vma_prot) |
| { |
| if (!pfn_is_map_memory(pfn)) |
| return pgprot_noncached(vma_prot); |
| else if (file->f_flags & O_SYNC) |
| return pgprot_writecombine(vma_prot); |
| return vma_prot; |
| } |
| EXPORT_SYMBOL(phys_mem_access_prot); |
| |
| static phys_addr_t __init early_pgtable_alloc(int shift) |
| { |
| phys_addr_t phys; |
| void *ptr; |
| |
| phys = memblock_phys_alloc_range(PAGE_SIZE, PAGE_SIZE, 0, |
| MEMBLOCK_ALLOC_NOLEAKTRACE); |
| if (!phys) |
| panic("Failed to allocate page table page\n"); |
| |
| /* |
| * The FIX_{PGD,PUD,PMD} slots may be in active use, but the FIX_PTE |
| * slot will be free, so we can (ab)use the FIX_PTE slot to initialise |
| * any level of table. |
| */ |
| ptr = pte_set_fixmap(phys); |
| |
| memset(ptr, 0, PAGE_SIZE); |
| |
| /* |
| * Implicit barriers also ensure the zeroed page is visible to the page |
| * table walker |
| */ |
| pte_clear_fixmap(); |
| |
| return phys; |
| } |
| |
| bool pgattr_change_is_safe(u64 old, u64 new) |
| { |
| /* |
| * The following mapping attributes may be updated in live |
| * kernel mappings without the need for break-before-make. |
| */ |
| pteval_t mask = PTE_PXN | PTE_RDONLY | PTE_WRITE | PTE_NG; |
| |
| /* creating or taking down mappings is always safe */ |
| if (!pte_valid(__pte(old)) || !pte_valid(__pte(new))) |
| return true; |
| |
| /* A live entry's pfn should not change */ |
| if (pte_pfn(__pte(old)) != pte_pfn(__pte(new))) |
| return false; |
| |
| /* live contiguous mappings may not be manipulated at all */ |
| if ((old | new) & PTE_CONT) |
| return false; |
| |
| /* Transitioning from Non-Global to Global is unsafe */ |
| if (old & ~new & PTE_NG) |
| return false; |
| |
| /* |
| * Changing the memory type between Normal and Normal-Tagged is safe |
| * since Tagged is considered a permission attribute from the |
| * mismatched attribute aliases perspective. |
| */ |
| if (((old & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL) || |
| (old & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL_TAGGED)) && |
| ((new & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL) || |
| (new & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL_TAGGED))) |
| mask |= PTE_ATTRINDX_MASK; |
| |
| return ((old ^ new) & ~mask) == 0; |
| } |
| |
| static void init_pte(pmd_t *pmdp, unsigned long addr, unsigned long end, |
| phys_addr_t phys, pgprot_t prot) |
| { |
| pte_t *ptep; |
| |
| ptep = pte_set_fixmap_offset(pmdp, addr); |
| do { |
| pte_t old_pte = READ_ONCE(*ptep); |
| |
| set_pte(ptep, pfn_pte(__phys_to_pfn(phys), prot)); |
| |
| /* |
| * After the PTE entry has been populated once, we |
| * only allow updates to the permission attributes. |
| */ |
| BUG_ON(!pgattr_change_is_safe(pte_val(old_pte), |
| READ_ONCE(pte_val(*ptep)))); |
| |
| phys += PAGE_SIZE; |
| } while (ptep++, addr += PAGE_SIZE, addr != end); |
| |
| pte_clear_fixmap(); |
| } |
| |
| static void alloc_init_cont_pte(pmd_t *pmdp, unsigned long addr, |
| unsigned long end, phys_addr_t phys, |
| pgprot_t prot, |
| phys_addr_t (*pgtable_alloc)(int), |
| int flags) |
| { |
| unsigned long next; |
| pmd_t pmd = READ_ONCE(*pmdp); |
| |
| BUG_ON(pmd_sect(pmd)); |
| if (pmd_none(pmd)) { |
| pmdval_t pmdval = PMD_TYPE_TABLE | PMD_TABLE_UXN; |
| phys_addr_t pte_phys; |
| |
| if (flags & NO_EXEC_MAPPINGS) |
| pmdval |= PMD_TABLE_PXN; |
| BUG_ON(!pgtable_alloc); |
| pte_phys = pgtable_alloc(PAGE_SHIFT); |
| __pmd_populate(pmdp, pte_phys, pmdval); |
| pmd = READ_ONCE(*pmdp); |
| } |
| BUG_ON(pmd_bad(pmd)); |
| |
| do { |
| pgprot_t __prot = prot; |
| |
| next = pte_cont_addr_end(addr, end); |
| |
| /* use a contiguous mapping if the range is suitably aligned */ |
| if ((((addr | next | phys) & ~CONT_PTE_MASK) == 0) && |
| (flags & NO_CONT_MAPPINGS) == 0) |
| __prot = __pgprot(pgprot_val(prot) | PTE_CONT); |
| |
| init_pte(pmdp, addr, next, phys, __prot); |
| |
| phys += next - addr; |
| } while (addr = next, addr != end); |
| } |
| |
| static void init_pmd(pud_t *pudp, unsigned long addr, unsigned long end, |
| phys_addr_t phys, pgprot_t prot, |
| phys_addr_t (*pgtable_alloc)(int), int flags) |
| { |
| unsigned long next; |
| pmd_t *pmdp; |
| |
| pmdp = pmd_set_fixmap_offset(pudp, addr); |
| do { |
| pmd_t old_pmd = READ_ONCE(*pmdp); |
| |
| next = pmd_addr_end(addr, end); |
| |
| /* try section mapping first */ |
| if (((addr | next | phys) & ~PMD_MASK) == 0 && |
| (flags & NO_BLOCK_MAPPINGS) == 0) { |
| pmd_set_huge(pmdp, phys, prot); |
| |
| /* |
| * After the PMD entry has been populated once, we |
| * only allow updates to the permission attributes. |
| */ |
| BUG_ON(!pgattr_change_is_safe(pmd_val(old_pmd), |
| READ_ONCE(pmd_val(*pmdp)))); |
| } else { |
| alloc_init_cont_pte(pmdp, addr, next, phys, prot, |
| pgtable_alloc, flags); |
| |
| BUG_ON(pmd_val(old_pmd) != 0 && |
| pmd_val(old_pmd) != READ_ONCE(pmd_val(*pmdp))); |
| } |
| phys += next - addr; |
| } while (pmdp++, addr = next, addr != end); |
| |
| pmd_clear_fixmap(); |
| } |
| |
| static void alloc_init_cont_pmd(pud_t *pudp, unsigned long addr, |
| unsigned long end, phys_addr_t phys, |
| pgprot_t prot, |
| phys_addr_t (*pgtable_alloc)(int), int flags) |
| { |
| unsigned long next; |
| pud_t pud = READ_ONCE(*pudp); |
| |
| /* |
| * Check for initial section mappings in the pgd/pud. |
| */ |
| BUG_ON(pud_sect(pud)); |
| if (pud_none(pud)) { |
| pudval_t pudval = PUD_TYPE_TABLE | PUD_TABLE_UXN; |
| phys_addr_t pmd_phys; |
| |
| if (flags & NO_EXEC_MAPPINGS) |
| pudval |= PUD_TABLE_PXN; |
| BUG_ON(!pgtable_alloc); |
| pmd_phys = pgtable_alloc(PMD_SHIFT); |
| __pud_populate(pudp, pmd_phys, pudval); |
| pud = READ_ONCE(*pudp); |
| } |
| BUG_ON(pud_bad(pud)); |
| |
| do { |
| pgprot_t __prot = prot; |
| |
| next = pmd_cont_addr_end(addr, end); |
| |
| /* use a contiguous mapping if the range is suitably aligned */ |
| if ((((addr | next | phys) & ~CONT_PMD_MASK) == 0) && |
| (flags & NO_CONT_MAPPINGS) == 0) |
| __prot = __pgprot(pgprot_val(prot) | PTE_CONT); |
| |
| init_pmd(pudp, addr, next, phys, __prot, pgtable_alloc, flags); |
| |
| phys += next - addr; |
| } while (addr = next, addr != end); |
| } |
| |
| static void alloc_init_pud(pgd_t *pgdp, unsigned long addr, unsigned long end, |
| phys_addr_t phys, pgprot_t prot, |
| phys_addr_t (*pgtable_alloc)(int), |
| int flags) |
| { |
| unsigned long next; |
| pud_t *pudp; |
| p4d_t *p4dp = p4d_offset(pgdp, addr); |
| p4d_t p4d = READ_ONCE(*p4dp); |
| |
| if (p4d_none(p4d)) { |
| p4dval_t p4dval = P4D_TYPE_TABLE | P4D_TABLE_UXN; |
| phys_addr_t pud_phys; |
| |
| if (flags & NO_EXEC_MAPPINGS) |
| p4dval |= P4D_TABLE_PXN; |
| BUG_ON(!pgtable_alloc); |
| pud_phys = pgtable_alloc(PUD_SHIFT); |
| __p4d_populate(p4dp, pud_phys, p4dval); |
| p4d = READ_ONCE(*p4dp); |
| } |
| BUG_ON(p4d_bad(p4d)); |
| |
| pudp = pud_set_fixmap_offset(p4dp, addr); |
| do { |
| pud_t old_pud = READ_ONCE(*pudp); |
| |
| next = pud_addr_end(addr, end); |
| |
| /* |
| * For 4K granule only, attempt to put down a 1GB block |
| */ |
| if (pud_sect_supported() && |
| ((addr | next | phys) & ~PUD_MASK) == 0 && |
| (flags & NO_BLOCK_MAPPINGS) == 0) { |
| pud_set_huge(pudp, phys, prot); |
| |
| /* |
| * After the PUD entry has been populated once, we |
| * only allow updates to the permission attributes. |
| */ |
| BUG_ON(!pgattr_change_is_safe(pud_val(old_pud), |
| READ_ONCE(pud_val(*pudp)))); |
| } else { |
| alloc_init_cont_pmd(pudp, addr, next, phys, prot, |
| pgtable_alloc, flags); |
| |
| BUG_ON(pud_val(old_pud) != 0 && |
| pud_val(old_pud) != READ_ONCE(pud_val(*pudp))); |
| } |
| phys += next - addr; |
| } while (pudp++, addr = next, addr != end); |
| |
| pud_clear_fixmap(); |
| } |
| |
| static void __create_pgd_mapping_locked(pgd_t *pgdir, phys_addr_t phys, |
| unsigned long virt, phys_addr_t size, |
| pgprot_t prot, |
| phys_addr_t (*pgtable_alloc)(int), |
| int flags) |
| { |
| unsigned long addr, end, next; |
| pgd_t *pgdp = pgd_offset_pgd(pgdir, virt); |
| |
| /* |
| * If the virtual and physical address don't have the same offset |
| * within a page, we cannot map the region as the caller expects. |
| */ |
| if (WARN_ON((phys ^ virt) & ~PAGE_MASK)) |
| return; |
| |
| phys &= PAGE_MASK; |
| addr = virt & PAGE_MASK; |
| end = PAGE_ALIGN(virt + size); |
| |
| do { |
| next = pgd_addr_end(addr, end); |
| alloc_init_pud(pgdp, addr, next, phys, prot, pgtable_alloc, |
| flags); |
| phys += next - addr; |
| } while (pgdp++, addr = next, addr != end); |
| } |
| |
| static void __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys, |
| unsigned long virt, phys_addr_t size, |
| pgprot_t prot, |
| phys_addr_t (*pgtable_alloc)(int), |
| int flags) |
| { |
| mutex_lock(&fixmap_lock); |
| __create_pgd_mapping_locked(pgdir, phys, virt, size, prot, |
| pgtable_alloc, flags); |
| mutex_unlock(&fixmap_lock); |
| } |
| |
| #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 |
| extern __alias(__create_pgd_mapping_locked) |
| void create_kpti_ng_temp_pgd(pgd_t *pgdir, phys_addr_t phys, unsigned long virt, |
| phys_addr_t size, pgprot_t prot, |
| phys_addr_t (*pgtable_alloc)(int), int flags); |
| #endif |
| |
| static phys_addr_t __pgd_pgtable_alloc(int shift) |
| { |
| void *ptr = (void *)__get_free_page(GFP_PGTABLE_KERNEL); |
| BUG_ON(!ptr); |
| |
| /* Ensure the zeroed page is visible to the page table walker */ |
| dsb(ishst); |
| return __pa(ptr); |
| } |
| |
| static phys_addr_t pgd_pgtable_alloc(int shift) |
| { |
| phys_addr_t pa = __pgd_pgtable_alloc(shift); |
| struct ptdesc *ptdesc = page_ptdesc(phys_to_page(pa)); |
| |
| /* |
| * Call proper page table ctor in case later we need to |
| * call core mm functions like apply_to_page_range() on |
| * this pre-allocated page table. |
| * |
| * We don't select ARCH_ENABLE_SPLIT_PMD_PTLOCK if pmd is |
| * folded, and if so pagetable_pte_ctor() becomes nop. |
| */ |
| if (shift == PAGE_SHIFT) |
| BUG_ON(!pagetable_pte_ctor(ptdesc)); |
| else if (shift == PMD_SHIFT) |
| BUG_ON(!pagetable_pmd_ctor(ptdesc)); |
| |
| return pa; |
| } |
| |
| /* |
| * This function can only be used to modify existing table entries, |
| * without allocating new levels of table. Note that this permits the |
| * creation of new section or page entries. |
| */ |
| void __init create_mapping_noalloc(phys_addr_t phys, unsigned long virt, |
| phys_addr_t size, pgprot_t prot) |
| { |
| if (virt < PAGE_OFFSET) { |
| pr_warn("BUG: not creating mapping for %pa at 0x%016lx - outside kernel range\n", |
| &phys, virt); |
| return; |
| } |
| __create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, NULL, |
| NO_CONT_MAPPINGS); |
| } |
| |
| void __init create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys, |
| unsigned long virt, phys_addr_t size, |
| pgprot_t prot, bool page_mappings_only) |
| { |
| int flags = 0; |
| |
| BUG_ON(mm == &init_mm); |
| |
| if (page_mappings_only) |
| flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; |
| |
| __create_pgd_mapping(mm->pgd, phys, virt, size, prot, |
| pgd_pgtable_alloc, flags); |
| } |
| |
| static void update_mapping_prot(phys_addr_t phys, unsigned long virt, |
| phys_addr_t size, pgprot_t prot) |
| { |
| if (virt < PAGE_OFFSET) { |
| pr_warn("BUG: not updating mapping for %pa at 0x%016lx - outside kernel range\n", |
| &phys, virt); |
| return; |
| } |
| |
| __create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, NULL, |
| NO_CONT_MAPPINGS); |
| |
| /* flush the TLBs after updating live kernel mappings */ |
| flush_tlb_kernel_range(virt, virt + size); |
| } |
| |
| static void __init __map_memblock(pgd_t *pgdp, phys_addr_t start, |
| phys_addr_t end, pgprot_t prot, int flags) |
| { |
| __create_pgd_mapping(pgdp, start, __phys_to_virt(start), end - start, |
| prot, early_pgtable_alloc, flags); |
| } |
| |
| void __init mark_linear_text_alias_ro(void) |
| { |
| /* |
| * Remove the write permissions from the linear alias of .text/.rodata |
| */ |
| update_mapping_prot(__pa_symbol(_stext), (unsigned long)lm_alias(_stext), |
| (unsigned long)__init_begin - (unsigned long)_stext, |
| PAGE_KERNEL_RO); |
| } |
| |
| #ifdef CONFIG_KFENCE |
| |
| bool __ro_after_init kfence_early_init = !!CONFIG_KFENCE_SAMPLE_INTERVAL; |
| |
| /* early_param() will be parsed before map_mem() below. */ |
| static int __init parse_kfence_early_init(char *arg) |
| { |
| int val; |
| |
| if (get_option(&arg, &val)) |
| kfence_early_init = !!val; |
| return 0; |
| } |
| early_param("kfence.sample_interval", parse_kfence_early_init); |
| |
| static phys_addr_t __init arm64_kfence_alloc_pool(void) |
| { |
| phys_addr_t kfence_pool; |
| |
| if (!kfence_early_init) |
| return 0; |
| |
| kfence_pool = memblock_phys_alloc(KFENCE_POOL_SIZE, PAGE_SIZE); |
| if (!kfence_pool) { |
| pr_err("failed to allocate kfence pool\n"); |
| kfence_early_init = false; |
| return 0; |
| } |
| |
| /* Temporarily mark as NOMAP. */ |
| memblock_mark_nomap(kfence_pool, KFENCE_POOL_SIZE); |
| |
| return kfence_pool; |
| } |
| |
| static void __init arm64_kfence_map_pool(phys_addr_t kfence_pool, pgd_t *pgdp) |
| { |
| if (!kfence_pool) |
| return; |
| |
| /* KFENCE pool needs page-level mapping. */ |
| __map_memblock(pgdp, kfence_pool, kfence_pool + KFENCE_POOL_SIZE, |
| pgprot_tagged(PAGE_KERNEL), |
| NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS); |
| memblock_clear_nomap(kfence_pool, KFENCE_POOL_SIZE); |
| __kfence_pool = phys_to_virt(kfence_pool); |
| } |
| #else /* CONFIG_KFENCE */ |
| |
| static inline phys_addr_t arm64_kfence_alloc_pool(void) { return 0; } |
| static inline void arm64_kfence_map_pool(phys_addr_t kfence_pool, pgd_t *pgdp) { } |
| |
| #endif /* CONFIG_KFENCE */ |
| |
| static void __init map_mem(pgd_t *pgdp) |
| { |
| static const u64 direct_map_end = _PAGE_END(VA_BITS_MIN); |
| phys_addr_t kernel_start = __pa_symbol(_stext); |
| phys_addr_t kernel_end = __pa_symbol(__init_begin); |
| phys_addr_t start, end; |
| phys_addr_t early_kfence_pool; |
| int flags = NO_EXEC_MAPPINGS; |
| u64 i; |
| |
| /* |
| * Setting hierarchical PXNTable attributes on table entries covering |
| * the linear region is only possible if it is guaranteed that no table |
| * entries at any level are being shared between the linear region and |
| * the vmalloc region. Check whether this is true for the PGD level, in |
| * which case it is guaranteed to be true for all other levels as well. |
| */ |
| BUILD_BUG_ON(pgd_index(direct_map_end - 1) == pgd_index(direct_map_end)); |
| |
| early_kfence_pool = arm64_kfence_alloc_pool(); |
| |
| if (can_set_direct_map()) |
| flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; |
| |
| /* |
| * Take care not to create a writable alias for the |
| * read-only text and rodata sections of the kernel image. |
| * So temporarily mark them as NOMAP to skip mappings in |
| * the following for-loop |
| */ |
| memblock_mark_nomap(kernel_start, kernel_end - kernel_start); |
| |
| /* map all the memory banks */ |
| for_each_mem_range(i, &start, &end) { |
| if (start >= end) |
| break; |
| /* |
| * The linear map must allow allocation tags reading/writing |
| * if MTE is present. Otherwise, it has the same attributes as |
| * PAGE_KERNEL. |
| */ |
| __map_memblock(pgdp, start, end, pgprot_tagged(PAGE_KERNEL), |
| flags); |
| } |
| |
| /* |
| * Map the linear alias of the [_stext, __init_begin) interval |
| * as non-executable now, and remove the write permission in |
| * mark_linear_text_alias_ro() below (which will be called after |
| * alternative patching has completed). This makes the contents |
| * of the region accessible to subsystems such as hibernate, |
| * but protects it from inadvertent modification or execution. |
| * Note that contiguous mappings cannot be remapped in this way, |
| * so we should avoid them here. |
| */ |
| __map_memblock(pgdp, kernel_start, kernel_end, |
| PAGE_KERNEL, NO_CONT_MAPPINGS); |
| memblock_clear_nomap(kernel_start, kernel_end - kernel_start); |
| arm64_kfence_map_pool(early_kfence_pool, pgdp); |
| } |
| |
| void mark_rodata_ro(void) |
| { |
| unsigned long section_size; |
| |
| /* |
| * mark .rodata as read only. Use __init_begin rather than __end_rodata |
| * to cover NOTES and EXCEPTION_TABLE. |
| */ |
| section_size = (unsigned long)__init_begin - (unsigned long)__start_rodata; |
| update_mapping_prot(__pa_symbol(__start_rodata), (unsigned long)__start_rodata, |
| section_size, PAGE_KERNEL_RO); |
| |
| debug_checkwx(); |
| } |
| |
| static void __init map_kernel_segment(pgd_t *pgdp, void *va_start, void *va_end, |
| pgprot_t prot, struct vm_struct *vma, |
| int flags, unsigned long vm_flags) |
| { |
| phys_addr_t pa_start = __pa_symbol(va_start); |
| unsigned long size = va_end - va_start; |
| |
| BUG_ON(!PAGE_ALIGNED(pa_start)); |
| BUG_ON(!PAGE_ALIGNED(size)); |
| |
| __create_pgd_mapping(pgdp, pa_start, (unsigned long)va_start, size, prot, |
| early_pgtable_alloc, flags); |
| |
| if (!(vm_flags & VM_NO_GUARD)) |
| size += PAGE_SIZE; |
| |
| vma->addr = va_start; |
| vma->phys_addr = pa_start; |
| vma->size = size; |
| vma->flags = VM_MAP | vm_flags; |
| vma->caller = __builtin_return_address(0); |
| |
| vm_area_add_early(vma); |
| } |
| |
| static pgprot_t kernel_exec_prot(void) |
| { |
| return rodata_enabled ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC; |
| } |
| |
| #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 |
| static int __init map_entry_trampoline(void) |
| { |
| int i; |
| |
| pgprot_t prot = kernel_exec_prot(); |
| phys_addr_t pa_start = __pa_symbol(__entry_tramp_text_start); |
| |
| /* The trampoline is always mapped and can therefore be global */ |
| pgprot_val(prot) &= ~PTE_NG; |
| |
| /* Map only the text into the trampoline page table */ |
| memset(tramp_pg_dir, 0, PGD_SIZE); |
| __create_pgd_mapping(tramp_pg_dir, pa_start, TRAMP_VALIAS, |
| entry_tramp_text_size(), prot, |
| __pgd_pgtable_alloc, NO_BLOCK_MAPPINGS); |
| |
| /* Map both the text and data into the kernel page table */ |
| for (i = 0; i < DIV_ROUND_UP(entry_tramp_text_size(), PAGE_SIZE); i++) |
| __set_fixmap(FIX_ENTRY_TRAMP_TEXT1 - i, |
| pa_start + i * PAGE_SIZE, prot); |
| |
| if (IS_ENABLED(CONFIG_RELOCATABLE)) |
| __set_fixmap(FIX_ENTRY_TRAMP_TEXT1 - i, |
| pa_start + i * PAGE_SIZE, PAGE_KERNEL_RO); |
| |
| return 0; |
| } |
| core_initcall(map_entry_trampoline); |
| #endif |
| |
| /* |
| * Open coded check for BTI, only for use to determine configuration |
| * for early mappings for before the cpufeature code has run. |
| */ |
| static bool arm64_early_this_cpu_has_bti(void) |
| { |
| u64 pfr1; |
| |
| if (!IS_ENABLED(CONFIG_ARM64_BTI_KERNEL)) |
| return false; |
| |
| pfr1 = __read_sysreg_by_encoding(SYS_ID_AA64PFR1_EL1); |
| return cpuid_feature_extract_unsigned_field(pfr1, |
| ID_AA64PFR1_EL1_BT_SHIFT); |
| } |
| |
| /* |
| * Create fine-grained mappings for the kernel. |
| */ |
| static void __init map_kernel(pgd_t *pgdp) |
| { |
| static struct vm_struct vmlinux_text, vmlinux_rodata, vmlinux_inittext, |
| vmlinux_initdata, vmlinux_data; |
| |
| /* |
| * External debuggers may need to write directly to the text |
| * mapping to install SW breakpoints. Allow this (only) when |
| * explicitly requested with rodata=off. |
| */ |
| pgprot_t text_prot = kernel_exec_prot(); |
| |
| /* |
| * If we have a CPU that supports BTI and a kernel built for |
| * BTI then mark the kernel executable text as guarded pages |
| * now so we don't have to rewrite the page tables later. |
| */ |
| if (arm64_early_this_cpu_has_bti()) |
| text_prot = __pgprot_modify(text_prot, PTE_GP, PTE_GP); |
| |
| /* |
| * Only rodata will be remapped with different permissions later on, |
| * all other segments are allowed to use contiguous mappings. |
| */ |
| map_kernel_segment(pgdp, _stext, _etext, text_prot, &vmlinux_text, 0, |
| VM_NO_GUARD); |
| map_kernel_segment(pgdp, __start_rodata, __inittext_begin, PAGE_KERNEL, |
| &vmlinux_rodata, NO_CONT_MAPPINGS, VM_NO_GUARD); |
| map_kernel_segment(pgdp, __inittext_begin, __inittext_end, text_prot, |
| &vmlinux_inittext, 0, VM_NO_GUARD); |
| map_kernel_segment(pgdp, __initdata_begin, __initdata_end, PAGE_KERNEL, |
| &vmlinux_initdata, 0, VM_NO_GUARD); |
| map_kernel_segment(pgdp, _data, _end, PAGE_KERNEL, &vmlinux_data, 0, 0); |
| |
| fixmap_copy(pgdp); |
| kasan_copy_shadow(pgdp); |
| } |
| |
| static void __init create_idmap(void) |
| { |
| u64 start = __pa_symbol(__idmap_text_start); |
| u64 size = __pa_symbol(__idmap_text_end) - start; |
| pgd_t *pgd = idmap_pg_dir; |
| u64 pgd_phys; |
| |
| /* check if we need an additional level of translation */ |
| if (VA_BITS < 48 && idmap_t0sz < (64 - VA_BITS_MIN)) { |
| pgd_phys = early_pgtable_alloc(PAGE_SHIFT); |
| set_pgd(&idmap_pg_dir[start >> VA_BITS], |
| __pgd(pgd_phys | P4D_TYPE_TABLE)); |
| pgd = __va(pgd_phys); |
| } |
| __create_pgd_mapping(pgd, start, start, size, PAGE_KERNEL_ROX, |
| early_pgtable_alloc, 0); |
| |
| if (IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0)) { |
| extern u32 __idmap_kpti_flag; |
| u64 pa = __pa_symbol(&__idmap_kpti_flag); |
| |
| /* |
| * The KPTI G-to-nG conversion code needs a read-write mapping |
| * of its synchronization flag in the ID map. |
| */ |
| __create_pgd_mapping(pgd, pa, pa, sizeof(u32), PAGE_KERNEL, |
| early_pgtable_alloc, 0); |
| } |
| } |
| |
| void __init paging_init(void) |
| { |
| pgd_t *pgdp = pgd_set_fixmap(__pa_symbol(swapper_pg_dir)); |
| extern pgd_t init_idmap_pg_dir[]; |
| |
| idmap_t0sz = 63UL - __fls(__pa_symbol(_end) | GENMASK(VA_BITS_MIN - 1, 0)); |
| |
| map_kernel(pgdp); |
| map_mem(pgdp); |
| |
| pgd_clear_fixmap(); |
| |
| cpu_replace_ttbr1(lm_alias(swapper_pg_dir), init_idmap_pg_dir); |
| init_mm.pgd = swapper_pg_dir; |
| |
| memblock_phys_free(__pa_symbol(init_pg_dir), |
| __pa_symbol(init_pg_end) - __pa_symbol(init_pg_dir)); |
| |
| memblock_allow_resize(); |
| |
| create_idmap(); |
| } |
| |
| #ifdef CONFIG_MEMORY_HOTPLUG |
| static void free_hotplug_page_range(struct page *page, size_t size, |
| struct vmem_altmap *altmap) |
| { |
| if (altmap) { |
| vmem_altmap_free(altmap, size >> PAGE_SHIFT); |
| } else { |
| WARN_ON(PageReserved(page)); |
| free_pages((unsigned long)page_address(page), get_order(size)); |
| } |
| } |
| |
| static void free_hotplug_pgtable_page(struct page *page) |
| { |
| free_hotplug_page_range(page, PAGE_SIZE, NULL); |
| } |
| |
| static bool pgtable_range_aligned(unsigned long start, unsigned long end, |
| unsigned long floor, unsigned long ceiling, |
| unsigned long mask) |
| { |
| start &= mask; |
| if (start < floor) |
| return false; |
| |
| if (ceiling) { |
| ceiling &= mask; |
| if (!ceiling) |
| return false; |
| } |
| |
| if (end - 1 > ceiling - 1) |
| return false; |
| return true; |
| } |
| |
| static void unmap_hotplug_pte_range(pmd_t *pmdp, unsigned long addr, |
| unsigned long end, bool free_mapped, |
| struct vmem_altmap *altmap) |
| { |
| pte_t *ptep, pte; |
| |
| do { |
| ptep = pte_offset_kernel(pmdp, addr); |
| pte = READ_ONCE(*ptep); |
| if (pte_none(pte)) |
| continue; |
| |
| WARN_ON(!pte_present(pte)); |
| pte_clear(&init_mm, addr, ptep); |
| flush_tlb_kernel_range(addr, addr + PAGE_SIZE); |
| if (free_mapped) |
| free_hotplug_page_range(pte_page(pte), |
| PAGE_SIZE, altmap); |
| } while (addr += PAGE_SIZE, addr < end); |
| } |
| |
| static void unmap_hotplug_pmd_range(pud_t *pudp, unsigned long addr, |
| unsigned long end, bool free_mapped, |
| struct vmem_altmap *altmap) |
| { |
| unsigned long next; |
| pmd_t *pmdp, pmd; |
| |
| do { |
| next = pmd_addr_end(addr, end); |
| pmdp = pmd_offset(pudp, addr); |
| pmd = READ_ONCE(*pmdp); |
| if (pmd_none(pmd)) |
| continue; |
| |
| WARN_ON(!pmd_present(pmd)); |
| if (pmd_sect(pmd)) { |
| pmd_clear(pmdp); |
| |
| /* |
| * One TLBI should be sufficient here as the PMD_SIZE |
| * range is mapped with a single block entry. |
| */ |
| flush_tlb_kernel_range(addr, addr + PAGE_SIZE); |
| if (free_mapped) |
| free_hotplug_page_range(pmd_page(pmd), |
| PMD_SIZE, altmap); |
| continue; |
| } |
| WARN_ON(!pmd_table(pmd)); |
| unmap_hotplug_pte_range(pmdp, addr, next, free_mapped, altmap); |
| } while (addr = next, addr < end); |
| } |
| |
| static void unmap_hotplug_pud_range(p4d_t *p4dp, unsigned long addr, |
| unsigned long end, bool free_mapped, |
| struct vmem_altmap *altmap) |
| { |
| unsigned long next; |
| pud_t *pudp, pud; |
| |
| do { |
| next = pud_addr_end(addr, end); |
| pudp = pud_offset(p4dp, addr); |
| pud = READ_ONCE(*pudp); |
| if (pud_none(pud)) |
| continue; |
| |
| WARN_ON(!pud_present(pud)); |
| if (pud_sect(pud)) { |
| pud_clear(pudp); |
| |
| /* |
| * One TLBI should be sufficient here as the PUD_SIZE |
| * range is mapped with a single block entry. |
| */ |
| flush_tlb_kernel_range(addr, addr + PAGE_SIZE); |
| if (free_mapped) |
| free_hotplug_page_range(pud_page(pud), |
| PUD_SIZE, altmap); |
| continue; |
| } |
| WARN_ON(!pud_table(pud)); |
| unmap_hotplug_pmd_range(pudp, addr, next, free_mapped, altmap); |
| } while (addr = next, addr < end); |
| } |
| |
| static void unmap_hotplug_p4d_range(pgd_t *pgdp, unsigned long addr, |
| unsigned long end, bool free_mapped, |
| struct vmem_altmap *altmap) |
| { |
| unsigned long next; |
| p4d_t *p4dp, p4d; |
| |
| do { |
| next = p4d_addr_end(addr, end); |
| p4dp = p4d_offset(pgdp, addr); |
| p4d = READ_ONCE(*p4dp); |
| if (p4d_none(p4d)) |
| continue; |
| |
| WARN_ON(!p4d_present(p4d)); |
| unmap_hotplug_pud_range(p4dp, addr, next, free_mapped, altmap); |
| } while (addr = next, addr < end); |
| } |
| |
| static void unmap_hotplug_range(unsigned long addr, unsigned long end, |
| bool free_mapped, struct vmem_altmap *altmap) |
| { |
| unsigned long next; |
| pgd_t *pgdp, pgd; |
| |
| /* |
| * altmap can only be used as vmemmap mapping backing memory. |
| * In case the backing memory itself is not being freed, then |
| * altmap is irrelevant. Warn about this inconsistency when |
| * encountered. |
| */ |
| WARN_ON(!free_mapped && altmap); |
| |
| do { |
| next = pgd_addr_end(addr, end); |
| pgdp = pgd_offset_k(addr); |
| pgd = READ_ONCE(*pgdp); |
| if (pgd_none(pgd)) |
| continue; |
| |
| WARN_ON(!pgd_present(pgd)); |
| unmap_hotplug_p4d_range(pgdp, addr, next, free_mapped, altmap); |
| } while (addr = next, addr < end); |
| } |
| |
| static void free_empty_pte_table(pmd_t *pmdp, unsigned long addr, |
| unsigned long end, unsigned long floor, |
| unsigned long ceiling) |
| { |
| pte_t *ptep, pte; |
| unsigned long i, start = addr; |
| |
| do { |
| ptep = pte_offset_kernel(pmdp, addr); |
| pte = READ_ONCE(*ptep); |
| |
| /* |
| * This is just a sanity check here which verifies that |
| * pte clearing has been done by earlier unmap loops. |
| */ |
| WARN_ON(!pte_none(pte)); |
| } while (addr += PAGE_SIZE, addr < end); |
| |
| if (!pgtable_range_aligned(start, end, floor, ceiling, PMD_MASK)) |
| return; |
| |
| /* |
| * Check whether we can free the pte page if the rest of the |
| * entries are empty. Overlap with other regions have been |
| * handled by the floor/ceiling check. |
| */ |
| ptep = pte_offset_kernel(pmdp, 0UL); |
| for (i = 0; i < PTRS_PER_PTE; i++) { |
| if (!pte_none(READ_ONCE(ptep[i]))) |
| return; |
| } |
| |
| pmd_clear(pmdp); |
| __flush_tlb_kernel_pgtable(start); |
| free_hotplug_pgtable_page(virt_to_page(ptep)); |
| } |
| |
| static void free_empty_pmd_table(pud_t *pudp, unsigned long addr, |
| unsigned long end, unsigned long floor, |
| unsigned long ceiling) |
| { |
| pmd_t *pmdp, pmd; |
| unsigned long i, next, start = addr; |
| |
| do { |
| next = pmd_addr_end(addr, end); |
| pmdp = pmd_offset(pudp, addr); |
| pmd = READ_ONCE(*pmdp); |
| if (pmd_none(pmd)) |
| continue; |
| |
| WARN_ON(!pmd_present(pmd) || !pmd_table(pmd) || pmd_sect(pmd)); |
| free_empty_pte_table(pmdp, addr, next, floor, ceiling); |
| } while (addr = next, addr < end); |
| |
| if (CONFIG_PGTABLE_LEVELS <= 2) |
| return; |
| |
| if (!pgtable_range_aligned(start, end, floor, ceiling, PUD_MASK)) |
| return; |
| |
| /* |
| * Check whether we can free the pmd page if the rest of the |
| * entries are empty. Overlap with other regions have been |
| * handled by the floor/ceiling check. |
| */ |
| pmdp = pmd_offset(pudp, 0UL); |
| for (i = 0; i < PTRS_PER_PMD; i++) { |
| if (!pmd_none(READ_ONCE(pmdp[i]))) |
| return; |
| } |
| |
| pud_clear(pudp); |
| __flush_tlb_kernel_pgtable(start); |
| free_hotplug_pgtable_page(virt_to_page(pmdp)); |
| } |
| |
| static void free_empty_pud_table(p4d_t *p4dp, unsigned long addr, |
| unsigned long end, unsigned long floor, |
| unsigned long ceiling) |
| { |
| pud_t *pudp, pud; |
| unsigned long i, next, start = addr; |
| |
| do { |
| next = pud_addr_end(addr, end); |
| pudp = pud_offset(p4dp, addr); |
| pud = READ_ONCE(*pudp); |
| if (pud_none(pud)) |
| continue; |
| |
| WARN_ON(!pud_present(pud) || !pud_table(pud) || pud_sect(pud)); |
| free_empty_pmd_table(pudp, addr, next, floor, ceiling); |
| } while (addr = next, addr < end); |
| |
| if (CONFIG_PGTABLE_LEVELS <= 3) |
| return; |
| |
| if (!pgtable_range_aligned(start, end, floor, ceiling, PGDIR_MASK)) |
| return; |
| |
| /* |
| * Check whether we can free the pud page if the rest of the |
| * entries are empty. Overlap with other regions have been |
| * handled by the floor/ceiling check. |
| */ |
| pudp = pud_offset(p4dp, 0UL); |
| for (i = 0; i < PTRS_PER_PUD; i++) { |
| if (!pud_none(READ_ONCE(pudp[i]))) |
| return; |
| } |
| |
| p4d_clear(p4dp); |
| __flush_tlb_kernel_pgtable(start); |
| free_hotplug_pgtable_page(virt_to_page(pudp)); |
| } |
| |
| static void free_empty_p4d_table(pgd_t *pgdp, unsigned long addr, |
| unsigned long end, unsigned long floor, |
| unsigned long ceiling) |
| { |
| unsigned long next; |
| p4d_t *p4dp, p4d; |
| |
| do { |
| next = p4d_addr_end(addr, end); |
| p4dp = p4d_offset(pgdp, addr); |
| p4d = READ_ONCE(*p4dp); |
| if (p4d_none(p4d)) |
| continue; |
| |
| WARN_ON(!p4d_present(p4d)); |
| free_empty_pud_table(p4dp, addr, next, floor, ceiling); |
| } while (addr = next, addr < end); |
| } |
| |
| static void free_empty_tables(unsigned long addr, unsigned long end, |
| unsigned long floor, unsigned long ceiling) |
| { |
| unsigned long next; |
| pgd_t *pgdp, pgd; |
| |
| do { |
| next = pgd_addr_end(addr, end); |
| pgdp = pgd_offset_k(addr); |
| pgd = READ_ONCE(*pgdp); |
| if (pgd_none(pgd)) |
| continue; |
| |
| WARN_ON(!pgd_present(pgd)); |
| free_empty_p4d_table(pgdp, addr, next, floor, ceiling); |
| } while (addr = next, addr < end); |
| } |
| #endif |
| |
| void __meminit vmemmap_set_pmd(pmd_t *pmdp, void *p, int node, |
| unsigned long addr, unsigned long next) |
| { |
| pmd_set_huge(pmdp, __pa(p), __pgprot(PROT_SECT_NORMAL)); |
| } |
| |
| int __meminit vmemmap_check_pmd(pmd_t *pmdp, int node, |
| unsigned long addr, unsigned long next) |
| { |
| vmemmap_verify((pte_t *)pmdp, node, addr, next); |
| return 1; |
| } |
| |
| int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, |
| struct vmem_altmap *altmap) |
| { |
| WARN_ON((start < VMEMMAP_START) || (end > VMEMMAP_END)); |
| |
| if (!IS_ENABLED(CONFIG_ARM64_4K_PAGES)) |
| return vmemmap_populate_basepages(start, end, node, altmap); |
| else |
| return vmemmap_populate_hugepages(start, end, node, altmap); |
| } |
| |
| #ifdef CONFIG_MEMORY_HOTPLUG |
| void vmemmap_free(unsigned long start, unsigned long end, |
| struct vmem_altmap *altmap) |
| { |
| WARN_ON((start < VMEMMAP_START) || (end > VMEMMAP_END)); |
| |
| unmap_hotplug_range(start, end, true, altmap); |
| free_empty_tables(start, end, VMEMMAP_START, VMEMMAP_END); |
| } |
| #endif /* CONFIG_MEMORY_HOTPLUG */ |
| |
| int pud_set_huge(pud_t *pudp, phys_addr_t phys, pgprot_t prot) |
| { |
| pud_t new_pud = pfn_pud(__phys_to_pfn(phys), mk_pud_sect_prot(prot)); |
| |
| /* Only allow permission changes for now */ |
| if (!pgattr_change_is_safe(READ_ONCE(pud_val(*pudp)), |
| pud_val(new_pud))) |
| return 0; |
| |
| VM_BUG_ON(phys & ~PUD_MASK); |
| set_pud(pudp, new_pud); |
| return 1; |
| } |
| |
| int pmd_set_huge(pmd_t *pmdp, phys_addr_t phys, pgprot_t prot) |
| { |
| pmd_t new_pmd = pfn_pmd(__phys_to_pfn(phys), mk_pmd_sect_prot(prot)); |
| |
| /* Only allow permission changes for now */ |
| if (!pgattr_change_is_safe(READ_ONCE(pmd_val(*pmdp)), |
| pmd_val(new_pmd))) |
| return 0; |
| |
| VM_BUG_ON(phys & ~PMD_MASK); |
| set_pmd(pmdp, new_pmd); |
| return 1; |
| } |
| |
| int pud_clear_huge(pud_t *pudp) |
| { |
| if (!pud_sect(READ_ONCE(*pudp))) |
| return 0; |
| pud_clear(pudp); |
| return 1; |
| } |
| |
| int pmd_clear_huge(pmd_t *pmdp) |
| { |
| if (!pmd_sect(READ_ONCE(*pmdp))) |
| return 0; |
| pmd_clear(pmdp); |
| return 1; |
| } |
| |
| int pmd_free_pte_page(pmd_t *pmdp, unsigned long addr) |
| { |
| pte_t *table; |
| pmd_t pmd; |
| |
| pmd = READ_ONCE(*pmdp); |
| |
| if (!pmd_table(pmd)) { |
| VM_WARN_ON(1); |
| return 1; |
| } |
| |
| table = pte_offset_kernel(pmdp, addr); |
| pmd_clear(pmdp); |
| __flush_tlb_kernel_pgtable(addr); |
| pte_free_kernel(NULL, table); |
| return 1; |
| } |
| |
| int pud_free_pmd_page(pud_t *pudp, unsigned long addr) |
| { |
| pmd_t *table; |
| pmd_t *pmdp; |
| pud_t pud; |
| unsigned long next, end; |
| |
| pud = READ_ONCE(*pudp); |
| |
| if (!pud_table(pud)) { |
| VM_WARN_ON(1); |
| return 1; |
| } |
| |
| table = pmd_offset(pudp, addr); |
| pmdp = table; |
| next = addr; |
| end = addr + PUD_SIZE; |
| do { |
| pmd_free_pte_page(pmdp, next); |
| } while (pmdp++, next += PMD_SIZE, next != end); |
| |
| pud_clear(pudp); |
| __flush_tlb_kernel_pgtable(addr); |
| pmd_free(NULL, table); |
| return 1; |
| } |
| |
| #ifdef CONFIG_MEMORY_HOTPLUG |
| static void __remove_pgd_mapping(pgd_t *pgdir, unsigned long start, u64 size) |
| { |
| unsigned long end = start + size; |
| |
| WARN_ON(pgdir != init_mm.pgd); |
| WARN_ON((start < PAGE_OFFSET) || (end > PAGE_END)); |
| |
| unmap_hotplug_range(start, end, false, NULL); |
| free_empty_tables(start, end, PAGE_OFFSET, PAGE_END); |
| } |
| |
| struct range arch_get_mappable_range(void) |
| { |
| struct range mhp_range; |
| u64 start_linear_pa = __pa(_PAGE_OFFSET(vabits_actual)); |
| u64 end_linear_pa = __pa(PAGE_END - 1); |
| |
| if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { |
| /* |
| * Check for a wrap, it is possible because of randomized linear |
| * mapping the start physical address is actually bigger than |
| * the end physical address. In this case set start to zero |
| * because [0, end_linear_pa] range must still be able to cover |
| * all addressable physical addresses. |
| */ |
| if (start_linear_pa > end_linear_pa) |
| start_linear_pa = 0; |
| } |
| |
| WARN_ON(start_linear_pa > end_linear_pa); |
| |
| /* |
| * Linear mapping region is the range [PAGE_OFFSET..(PAGE_END - 1)] |
| * accommodating both its ends but excluding PAGE_END. Max physical |
| * range which can be mapped inside this linear mapping range, must |
| * also be derived from its end points. |
| */ |
| mhp_range.start = start_linear_pa; |
| mhp_range.end = end_linear_pa; |
| |
| return mhp_range; |
| } |
| |
| int arch_add_memory(int nid, u64 start, u64 size, |
| struct mhp_params *params) |
| { |
| int ret, flags = NO_EXEC_MAPPINGS; |
| |
| VM_BUG_ON(!mhp_range_allowed(start, size, true)); |
| |
| if (can_set_direct_map()) |
| flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; |
| |
| __create_pgd_mapping(swapper_pg_dir, start, __phys_to_virt(start), |
| size, params->pgprot, __pgd_pgtable_alloc, |
| flags); |
| |
| memblock_clear_nomap(start, size); |
| |
| ret = __add_pages(nid, start >> PAGE_SHIFT, size >> PAGE_SHIFT, |
| params); |
| if (ret) |
| __remove_pgd_mapping(swapper_pg_dir, |
| __phys_to_virt(start), size); |
| else { |
| max_pfn = PFN_UP(start + size); |
| max_low_pfn = max_pfn; |
| } |
| |
| return ret; |
| } |
| |
| void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap) |
| { |
| unsigned long start_pfn = start >> PAGE_SHIFT; |
| unsigned long nr_pages = size >> PAGE_SHIFT; |
| |
| __remove_pages(start_pfn, nr_pages, altmap); |
| __remove_pgd_mapping(swapper_pg_dir, __phys_to_virt(start), size); |
| } |
| |
| /* |
| * This memory hotplug notifier helps prevent boot memory from being |
| * inadvertently removed as it blocks pfn range offlining process in |
| * __offline_pages(). Hence this prevents both offlining as well as |
| * removal process for boot memory which is initially always online. |
| * In future if and when boot memory could be removed, this notifier |
| * should be dropped and free_hotplug_page_range() should handle any |
| * reserved pages allocated during boot. |
| */ |
| static int prevent_bootmem_remove_notifier(struct notifier_block *nb, |
| unsigned long action, void *data) |
| { |
| struct mem_section *ms; |
| struct memory_notify *arg = data; |
| unsigned long end_pfn = arg->start_pfn + arg->nr_pages; |
| unsigned long pfn = arg->start_pfn; |
| |
| if ((action != MEM_GOING_OFFLINE) && (action != MEM_OFFLINE)) |
| return NOTIFY_OK; |
| |
| for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { |
| unsigned long start = PFN_PHYS(pfn); |
| unsigned long end = start + (1UL << PA_SECTION_SHIFT); |
| |
| ms = __pfn_to_section(pfn); |
| if (!early_section(ms)) |
| continue; |
| |
| if (action == MEM_GOING_OFFLINE) { |
| /* |
| * Boot memory removal is not supported. Prevent |
| * it via blocking any attempted offline request |
| * for the boot memory and just report it. |
| */ |
| pr_warn("Boot memory [%lx %lx] offlining attempted\n", start, end); |
| return NOTIFY_BAD; |
| } else if (action == MEM_OFFLINE) { |
| /* |
| * This should have never happened. Boot memory |
| * offlining should have been prevented by this |
| * very notifier. Probably some memory removal |
| * procedure might have changed which would then |
| * require further debug. |
| */ |
| pr_err("Boot memory [%lx %lx] offlined\n", start, end); |
| |
| /* |
| * Core memory hotplug does not process a return |
| * code from the notifier for MEM_OFFLINE events. |
| * The error condition has been reported. Return |
| * from here as if ignored. |
| */ |
| return NOTIFY_DONE; |
| } |
| } |
| return NOTIFY_OK; |
| } |
| |
| static struct notifier_block prevent_bootmem_remove_nb = { |
| .notifier_call = prevent_bootmem_remove_notifier, |
| }; |
| |
| /* |
| * This ensures that boot memory sections on the platform are online |
| * from early boot. Memory sections could not be prevented from being |
| * offlined, unless for some reason they are not online to begin with. |
| * This helps validate the basic assumption on which the above memory |
| * event notifier works to prevent boot memory section offlining and |
| * its possible removal. |
| */ |
| static void validate_bootmem_online(void) |
| { |
| phys_addr_t start, end, addr; |
| struct mem_section *ms; |
| u64 i; |
| |
| /* |
| * Scanning across all memblock might be expensive |
| * on some big memory systems. Hence enable this |
| * validation only with DEBUG_VM. |
| */ |
| if (!IS_ENABLED(CONFIG_DEBUG_VM)) |
| return; |
| |
| for_each_mem_range(i, &start, &end) { |
| for (addr = start; addr < end; addr += (1UL << PA_SECTION_SHIFT)) { |
| ms = __pfn_to_section(PHYS_PFN(addr)); |
| |
| /* |
| * All memory ranges in the system at this point |
| * should have been marked as early sections. |
| */ |
| WARN_ON(!early_section(ms)); |
| |
| /* |
| * Memory notifier mechanism here to prevent boot |
| * memory offlining depends on the fact that each |
| * early section memory on the system is initially |
| * online. Otherwise a given memory section which |
| * is already offline will be overlooked and can |
| * be removed completely. Call out such sections. |
| */ |
| if (!online_section(ms)) |
| pr_err("Boot memory [%llx %llx] is offline, can be removed\n", |
| addr, addr + (1UL << PA_SECTION_SHIFT)); |
| } |
| } |
| } |
| |
| static int __init prevent_bootmem_remove_init(void) |
| { |
| int ret = 0; |
| |
| if (!IS_ENABLED(CONFIG_MEMORY_HOTREMOVE)) |
| return ret; |
| |
| validate_bootmem_online(); |
| ret = register_memory_notifier(&prevent_bootmem_remove_nb); |
| if (ret) |
| pr_err("%s: Notifier registration failed %d\n", __func__, ret); |
| |
| return ret; |
| } |
| early_initcall(prevent_bootmem_remove_init); |
| #endif |
| |
| pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) |
| { |
| if (IS_ENABLED(CONFIG_ARM64_ERRATUM_2645198) && |
| cpus_have_const_cap(ARM64_WORKAROUND_2645198)) { |
| /* |
| * Break-before-make (BBM) is required for all user space mappings |
| * when the permission changes from executable to non-executable |
| * in cases where cpu is affected with errata #2645198. |
| */ |
| if (pte_user_exec(READ_ONCE(*ptep))) |
| return ptep_clear_flush(vma, addr, ptep); |
| } |
| return ptep_get_and_clear(vma->vm_mm, addr, ptep); |
| } |
| |
| void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep, |
| pte_t old_pte, pte_t pte) |
| { |
| set_pte_at(vma->vm_mm, addr, ptep, pte); |
| } |