1 // SPDX-License-Identifier: GPL-2.0
2
3 #define DISABLE_BRANCH_PROFILING
4
5 #include <linux/kasan.h>
6 #include <linux/memblock.h>
7 #include <linux/hugetlb.h>
8
9 #include <asm/pgalloc.h>
10
11 static int __init
12 kasan_init_shadow_8M(unsigned long k_start, unsigned long k_end, void *block)
13 {
14 pmd_t *pmd = pmd_off_k(k_start);
15 unsigned long k_cur, k_next;
16
17 for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd++, block += SZ_4M) {
18 pte_t *ptep;
19 int i;
20
21 k_next = pgd_addr_end(k_cur, k_end);
22 if ((void *)pmd_page_vaddr(*pmd) != kasan_early_shadow_pte)
23 continue;
24
25 ptep = memblock_alloc(PTE_FRAG_SIZE, PTE_FRAG_SIZE);
26 if (!ptep)
27 return -ENOMEM;
28
29 for (i = 0; i < PTRS_PER_PTE; i++) {
30 pte_t pte = pte_mkhuge(pfn_pte(PHYS_PFN(__pa(block + i * PAGE_SIZE)), PAGE_KERNEL));
31
32 __set_pte_at(&init_mm, k_cur, ptep + i, pte, 1);
33 }
34 pmd_populate_kernel(&init_mm, pmd, ptep);
35 *pmd = __pmd(pmd_val(*pmd) | _PMD_PAGE_8M);
36 }
37 return 0;
38 }
39
40 int __init kasan_init_region(void *start, size_t size)
41 {
42 unsigned long k_start = (unsigned long)kasan_mem_to_shadow(start);
43 unsigned long k_end = (unsigned long)kasan_mem_to_shadow(start + size);
44 unsigned long k_cur;
45 int ret;
46 void *block;
47
48 block = memblock_alloc(k_end - k_start, SZ_8M);
49 if (!block)
50 return -ENOMEM;
51
52 if (IS_ALIGNED(k_start, SZ_8M)) {
53 kasan_init_shadow_8M(k_start, ALIGN_DOWN(k_end, SZ_8M), block);
54 k_cur = ALIGN_DOWN(k_end, SZ_8M);
55 if (k_cur == k_end)
56 goto finish;
57 } else {
58 k_cur = k_start;
59 }
60
61 ret = kasan_init_shadow_page_tables(k_start, k_end);
62 if (ret)
63 return ret;
64
65 for (; k_cur < k_end; k_cur += PAGE_SIZE) {
66 pmd_t *pmd = pmd_off_k(k_cur);
67 void *va = block + k_cur - k_start;
68 pte_t pte = pfn_pte(PHYS_PFN(__pa(va)), PAGE_KERNEL);
69
70 if (k_cur < ALIGN_DOWN(k_end, SZ_512K))
71 pte = pte_mkhuge(pte);
72
73 __set_pte_at(&init_mm, k_cur, pte_offset_kernel(pmd, k_cur), pte, 0);
74 }
75 finish:
76 flush_tlb_kernel_range(k_start, k_end);
77 return 0;
78 }
79
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