1 // SPDX-License-Identifier: GPL-2.0
3 #define DISABLE_BRANCH_PROFILING
5 #include <linux/kasan.h>
6 #include <linux/printk.h>
7 #include <linux/memblock.h>
8 #include <linux/moduleloader.h>
9 #include <linux/sched/task.h>
10 #include <linux/vmalloc.h>
11 #include <asm/pgalloc.h>
12 #include <asm/code-patching.h>
13 #include <mm/mmu_decl.h>
15 static pgprot_t __init kasan_prot_ro(void)
17 if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE))
20 return PAGE_KERNEL_RO;
23 static void __init kasan_populate_pte(pte_t *ptep, pgprot_t prot)
25 unsigned long va = (unsigned long)kasan_early_shadow_page;
26 phys_addr_t pa = __pa(kasan_early_shadow_page);
29 for (i = 0; i < PTRS_PER_PTE; i++, ptep++)
30 __set_pte_at(&init_mm, va, ptep, pfn_pte(PHYS_PFN(pa), prot), 0);
33 static int __init kasan_init_shadow_page_tables(unsigned long k_start, unsigned long k_end)
36 unsigned long k_cur, k_next;
39 pmd = pmd_offset(pud_offset(pgd_offset_k(k_start), k_start), k_start);
41 for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd++) {
42 k_next = pgd_addr_end(k_cur, k_end);
43 if ((void *)pmd_page_vaddr(*pmd) != kasan_early_shadow_pte)
47 new = memblock_alloc(PTE_FRAG_SIZE, PTE_FRAG_SIZE);
51 kasan_populate_pte(new, PAGE_KERNEL);
53 smp_wmb(); /* See comment in __pte_alloc */
55 spin_lock(&init_mm.page_table_lock);
56 /* Has another populated it ? */
57 if (likely((void *)pmd_page_vaddr(*pmd) == kasan_early_shadow_pte)) {
58 pmd_populate_kernel(&init_mm, pmd, new);
61 spin_unlock(&init_mm.page_table_lock);
66 static int __init kasan_init_region(void *start, size_t size)
68 unsigned long k_start = (unsigned long)kasan_mem_to_shadow(start);
69 unsigned long k_end = (unsigned long)kasan_mem_to_shadow(start + size);
74 ret = kasan_init_shadow_page_tables(k_start, k_end);
78 block = memblock_alloc(k_end - k_start, PAGE_SIZE);
80 for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
81 pmd_t *pmd = pmd_offset(pud_offset(pgd_offset_k(k_cur), k_cur), k_cur);
82 void *va = block + k_cur - k_start;
83 pte_t pte = pfn_pte(PHYS_PFN(__pa(va)), PAGE_KERNEL);
88 __set_pte_at(&init_mm, k_cur, pte_offset_kernel(pmd, k_cur), pte, 0);
90 flush_tlb_kernel_range(k_start, k_end);
94 static void __init kasan_remap_early_shadow_ro(void)
96 pgprot_t prot = kasan_prot_ro();
97 unsigned long k_start = KASAN_SHADOW_START;
98 unsigned long k_end = KASAN_SHADOW_END;
100 phys_addr_t pa = __pa(kasan_early_shadow_page);
102 kasan_populate_pte(kasan_early_shadow_pte, prot);
104 for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
105 pmd_t *pmd = pmd_offset(pud_offset(pgd_offset_k(k_cur), k_cur), k_cur);
106 pte_t *ptep = pte_offset_kernel(pmd, k_cur);
108 if ((pte_val(*ptep) & PTE_RPN_MASK) != pa)
111 __set_pte_at(&init_mm, k_cur, ptep, pfn_pte(PHYS_PFN(pa), prot), 0);
113 flush_tlb_kernel_range(KASAN_SHADOW_START, KASAN_SHADOW_END);
116 static void __init kasan_unmap_early_shadow_vmalloc(void)
118 unsigned long k_start = (unsigned long)kasan_mem_to_shadow((void *)VMALLOC_START);
119 unsigned long k_end = (unsigned long)kasan_mem_to_shadow((void *)VMALLOC_END);
121 phys_addr_t pa = __pa(kasan_early_shadow_page);
123 if (!early_mmu_has_feature(MMU_FTR_HPTE_TABLE)) {
124 int ret = kasan_init_shadow_page_tables(k_start, k_end);
127 panic("kasan: kasan_init_shadow_page_tables() failed");
129 for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
130 pmd_t *pmd = pmd_offset(pud_offset(pgd_offset_k(k_cur), k_cur), k_cur);
131 pte_t *ptep = pte_offset_kernel(pmd, k_cur);
133 if ((pte_val(*ptep) & PTE_RPN_MASK) != pa)
136 __set_pte_at(&init_mm, k_cur, ptep, __pte(0), 0);
138 flush_tlb_kernel_range(k_start, k_end);
141 void __init kasan_mmu_init(void)
144 struct memblock_region *reg;
146 if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE)) {
147 ret = kasan_init_shadow_page_tables(KASAN_SHADOW_START, KASAN_SHADOW_END);
150 panic("kasan: kasan_init_shadow_page_tables() failed");
153 for_each_memblock(memory, reg) {
154 phys_addr_t base = reg->base;
155 phys_addr_t top = min(base + reg->size, total_lowmem);
160 ret = kasan_init_region(__va(base), top - base);
162 panic("kasan: kasan_init_region() failed");
166 void __init kasan_init(void)
168 kasan_remap_early_shadow_ro();
170 clear_page(kasan_early_shadow_page);
172 /* At this point kasan is fully initialized. Enable error messages */
173 init_task.kasan_depth = 0;
174 pr_info("KASAN init done\n");
177 void __init kasan_late_init(void)
179 if (IS_ENABLED(CONFIG_KASAN_VMALLOC))
180 kasan_unmap_early_shadow_vmalloc();
183 #ifdef CONFIG_PPC_BOOK3S_32
184 u8 __initdata early_hash[256 << 10] __aligned(256 << 10) = {0};
186 static void __init kasan_early_hash_table(void)
188 unsigned int hash = IS_ENABLED(CONFIG_VMAP_STACK) ? (unsigned int)early_hash :
191 modify_instruction_site(&patch__hash_page_A0, 0xffff, hash >> 16);
192 modify_instruction_site(&patch__flush_hash_A0, 0xffff, hash >> 16);
194 Hash = (struct hash_pte *)early_hash;
197 static void __init kasan_early_hash_table(void) {}
200 void __init kasan_early_init(void)
202 unsigned long addr = KASAN_SHADOW_START;
203 unsigned long end = KASAN_SHADOW_END;
205 pmd_t *pmd = pmd_offset(pud_offset(pgd_offset_k(addr), addr), addr);
207 BUILD_BUG_ON(KASAN_SHADOW_START & ~PGDIR_MASK);
209 kasan_populate_pte(kasan_early_shadow_pte, PAGE_KERNEL);
212 next = pgd_addr_end(addr, end);
213 pmd_populate_kernel(&init_mm, pmd, kasan_early_shadow_pte);
214 } while (pmd++, addr = next, addr != end);
216 if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE))
217 kasan_early_hash_table();