1 // SPDX-License-Identifier: GPL-2.0 2 // Copyright (C) 2019 Andes Technology Corporation 3 4 #include <linux/pfn.h> 5 #include <linux/init_task.h> 6 #include <linux/kasan.h> 7 #include <linux/kernel.h> 8 #include <linux/memblock.h> 9 #include <linux/pgtable.h> 10 #include <asm/tlbflush.h> 11 #include <asm/fixmap.h> 12 #include <asm/pgalloc.h> 13 14 static __init void *early_alloc(size_t size, int node) 15 { 16 void *ptr = memblock_alloc_try_nid(size, size, 17 __pa(MAX_DMA_ADDRESS), MEMBLOCK_ALLOC_ACCESSIBLE, node); 18 19 if (!ptr) 20 panic("%pS: Failed to allocate %zu bytes align=%zx nid=%d from=%llx\n", 21 __func__, size, size, node, (u64)__pa(MAX_DMA_ADDRESS)); 22 23 return ptr; 24 } 25 26 extern pgd_t early_pg_dir[PTRS_PER_PGD]; 27 asmlinkage void __init kasan_early_init(void) 28 { 29 uintptr_t i; 30 pgd_t *pgd = early_pg_dir + pgd_index(KASAN_SHADOW_START); 31 32 for (i = 0; i < PTRS_PER_PTE; ++i) 33 set_pte(kasan_early_shadow_pte + i, 34 mk_pte(virt_to_page(kasan_early_shadow_page), 35 PAGE_KERNEL)); 36 37 for (i = 0; i < PTRS_PER_PMD; ++i) 38 set_pmd(kasan_early_shadow_pmd + i, 39 pfn_pmd(PFN_DOWN 40 (__pa((uintptr_t) kasan_early_shadow_pte)), 41 __pgprot(_PAGE_TABLE))); 42 43 for (i = KASAN_SHADOW_START; i < KASAN_SHADOW_END; 44 i += PGDIR_SIZE, ++pgd) 45 set_pgd(pgd, 46 pfn_pgd(PFN_DOWN 47 (__pa(((uintptr_t) kasan_early_shadow_pmd))), 48 __pgprot(_PAGE_TABLE))); 49 50 /* init for swapper_pg_dir */ 51 pgd = pgd_offset_k(KASAN_SHADOW_START); 52 53 for (i = KASAN_SHADOW_START; i < KASAN_SHADOW_END; 54 i += PGDIR_SIZE, ++pgd) 55 set_pgd(pgd, 56 pfn_pgd(PFN_DOWN 57 (__pa(((uintptr_t) kasan_early_shadow_pmd))), 58 __pgprot(_PAGE_TABLE))); 59 60 local_flush_tlb_all(); 61 } 62 63 static void kasan_populate_pte(pmd_t *pmd, unsigned long vaddr, unsigned long end) 64 { 65 phys_addr_t phys_addr; 66 pte_t *ptep, *base_pte; 67 68 if (pmd_none(*pmd)) 69 base_pte = memblock_alloc(PTRS_PER_PTE * sizeof(pte_t), PAGE_SIZE); 70 else 71 base_pte = (pte_t *)pmd_page_vaddr(*pmd); 72 73 ptep = base_pte + pte_index(vaddr); 74 75 do { 76 if (pte_none(*ptep)) { 77 phys_addr = memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); 78 set_pte(ptep, pfn_pte(PFN_DOWN(phys_addr), PAGE_KERNEL)); 79 } 80 } while (ptep++, vaddr += PAGE_SIZE, vaddr != end); 81 82 set_pmd(pmd, pfn_pmd(PFN_DOWN(__pa(base_pte)), PAGE_TABLE)); 83 } 84 85 static void kasan_populate_pmd(pgd_t *pgd, unsigned long vaddr, unsigned long end) 86 { 87 phys_addr_t phys_addr; 88 pmd_t *pmdp, *base_pmd; 89 unsigned long next; 90 91 base_pmd = (pmd_t *)pgd_page_vaddr(*pgd); 92 if (base_pmd == lm_alias(kasan_early_shadow_pmd)) 93 base_pmd = memblock_alloc(PTRS_PER_PMD * sizeof(pmd_t), PAGE_SIZE); 94 95 pmdp = base_pmd + pmd_index(vaddr); 96 97 do { 98 next = pmd_addr_end(vaddr, end); 99 100 if (pmd_none(*pmdp) && IS_ALIGNED(vaddr, PMD_SIZE) && (next - vaddr) >= PMD_SIZE) { 101 phys_addr = memblock_phys_alloc(PMD_SIZE, PMD_SIZE); 102 if (phys_addr) { 103 set_pmd(pmdp, pfn_pmd(PFN_DOWN(phys_addr), PAGE_KERNEL)); 104 continue; 105 } 106 } 107 108 kasan_populate_pte(pmdp, vaddr, next); 109 } while (pmdp++, vaddr = next, vaddr != end); 110 111 /* 112 * Wait for the whole PGD to be populated before setting the PGD in 113 * the page table, otherwise, if we did set the PGD before populating 114 * it entirely, memblock could allocate a page at a physical address 115 * where KASAN is not populated yet and then we'd get a page fault. 116 */ 117 set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa(base_pmd)), PAGE_TABLE)); 118 } 119 120 static void kasan_populate_pgd(unsigned long vaddr, unsigned long end) 121 { 122 phys_addr_t phys_addr; 123 pgd_t *pgdp = pgd_offset_k(vaddr); 124 unsigned long next; 125 126 do { 127 next = pgd_addr_end(vaddr, end); 128 129 /* 130 * pgdp can't be none since kasan_early_init initialized all KASAN 131 * shadow region with kasan_early_shadow_pmd: if this is stillthe case, 132 * that means we can try to allocate a hugepage as a replacement. 133 */ 134 if (pgd_page_vaddr(*pgdp) == (unsigned long)lm_alias(kasan_early_shadow_pmd) && 135 IS_ALIGNED(vaddr, PGDIR_SIZE) && (next - vaddr) >= PGDIR_SIZE) { 136 phys_addr = memblock_phys_alloc(PGDIR_SIZE, PGDIR_SIZE); 137 if (phys_addr) { 138 set_pgd(pgdp, pfn_pgd(PFN_DOWN(phys_addr), PAGE_KERNEL)); 139 continue; 140 } 141 } 142 143 kasan_populate_pmd(pgdp, vaddr, next); 144 } while (pgdp++, vaddr = next, vaddr != end); 145 } 146 147 static void __init kasan_populate(void *start, void *end) 148 { 149 unsigned long vaddr = (unsigned long)start & PAGE_MASK; 150 unsigned long vend = PAGE_ALIGN((unsigned long)end); 151 152 kasan_populate_pgd(vaddr, vend); 153 154 local_flush_tlb_all(); 155 memset(start, KASAN_SHADOW_INIT, end - start); 156 } 157 158 void __init kasan_shallow_populate(void *start, void *end) 159 { 160 unsigned long vaddr = (unsigned long)start & PAGE_MASK; 161 unsigned long vend = PAGE_ALIGN((unsigned long)end); 162 unsigned long pfn; 163 int index; 164 void *p; 165 pud_t *pud_dir, *pud_k; 166 pgd_t *pgd_dir, *pgd_k; 167 p4d_t *p4d_dir, *p4d_k; 168 169 while (vaddr < vend) { 170 index = pgd_index(vaddr); 171 pfn = csr_read(CSR_SATP) & SATP_PPN; 172 pgd_dir = (pgd_t *)pfn_to_virt(pfn) + index; 173 pgd_k = init_mm.pgd + index; 174 pgd_dir = pgd_offset_k(vaddr); 175 set_pgd(pgd_dir, *pgd_k); 176 177 p4d_dir = p4d_offset(pgd_dir, vaddr); 178 p4d_k = p4d_offset(pgd_k, vaddr); 179 180 vaddr = (vaddr + PUD_SIZE) & PUD_MASK; 181 pud_dir = pud_offset(p4d_dir, vaddr); 182 pud_k = pud_offset(p4d_k, vaddr); 183 184 if (pud_present(*pud_dir)) { 185 p = early_alloc(PAGE_SIZE, NUMA_NO_NODE); 186 pud_populate(&init_mm, pud_dir, p); 187 } 188 vaddr += PAGE_SIZE; 189 } 190 } 191 192 void __init kasan_init(void) 193 { 194 phys_addr_t _start, _end; 195 u64 i; 196 197 kasan_populate_early_shadow((void *)KASAN_SHADOW_START, 198 (void *)kasan_mem_to_shadow((void *) 199 VMEMMAP_END)); 200 if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) 201 kasan_shallow_populate( 202 (void *)kasan_mem_to_shadow((void *)VMALLOC_START), 203 (void *)kasan_mem_to_shadow((void *)VMALLOC_END)); 204 else 205 kasan_populate_early_shadow( 206 (void *)kasan_mem_to_shadow((void *)VMALLOC_START), 207 (void *)kasan_mem_to_shadow((void *)VMALLOC_END)); 208 209 for_each_mem_range(i, &_start, &_end) { 210 void *start = (void *)__va(_start); 211 void *end = (void *)__va(_end); 212 213 if (start >= end) 214 break; 215 216 kasan_populate(kasan_mem_to_shadow(start), kasan_mem_to_shadow(end)); 217 }; 218 219 for (i = 0; i < PTRS_PER_PTE; i++) 220 set_pte(&kasan_early_shadow_pte[i], 221 mk_pte(virt_to_page(kasan_early_shadow_page), 222 __pgprot(_PAGE_PRESENT | _PAGE_READ | 223 _PAGE_ACCESSED))); 224 225 memset(kasan_early_shadow_page, KASAN_SHADOW_INIT, PAGE_SIZE); 226 init_task.kasan_depth = 0; 227 } 228