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
13 extern pgd_t early_pg_dir[PTRS_PER_PGD];
kasan_early_init(void)14 asmlinkage void __init kasan_early_init(void)
15 {
16 uintptr_t i;
17 pgd_t *pgd = early_pg_dir + pgd_index(KASAN_SHADOW_START);
18
19 BUILD_BUG_ON(KASAN_SHADOW_OFFSET !=
20 KASAN_SHADOW_END - (1UL << (64 - KASAN_SHADOW_SCALE_SHIFT)));
21
22 for (i = 0; i < PTRS_PER_PTE; ++i)
23 set_pte(kasan_early_shadow_pte + i,
24 mk_pte(virt_to_page(kasan_early_shadow_page),
25 PAGE_KERNEL));
26
27 for (i = 0; i < PTRS_PER_PMD; ++i)
28 set_pmd(kasan_early_shadow_pmd + i,
29 pfn_pmd(PFN_DOWN
30 (__pa((uintptr_t) kasan_early_shadow_pte)),
31 __pgprot(_PAGE_TABLE)));
32
33 for (i = KASAN_SHADOW_START; i < KASAN_SHADOW_END;
34 i += PGDIR_SIZE, ++pgd)
35 set_pgd(pgd,
36 pfn_pgd(PFN_DOWN
37 (__pa(((uintptr_t) kasan_early_shadow_pmd))),
38 __pgprot(_PAGE_TABLE)));
39
40 /* init for swapper_pg_dir */
41 pgd = pgd_offset_k(KASAN_SHADOW_START);
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 local_flush_tlb_all();
51 }
52
populate(void * start,void * end)53 static void __init populate(void *start, void *end)
54 {
55 unsigned long i, offset;
56 unsigned long vaddr = (unsigned long)start & PAGE_MASK;
57 unsigned long vend = PAGE_ALIGN((unsigned long)end);
58 unsigned long n_pages = (vend - vaddr) / PAGE_SIZE;
59 unsigned long n_ptes =
60 ((n_pages + PTRS_PER_PTE) & -PTRS_PER_PTE) / PTRS_PER_PTE;
61 unsigned long n_pmds =
62 ((n_ptes + PTRS_PER_PMD) & -PTRS_PER_PMD) / PTRS_PER_PMD;
63
64 pte_t *pte =
65 memblock_alloc(n_ptes * PTRS_PER_PTE * sizeof(pte_t), PAGE_SIZE);
66 pmd_t *pmd =
67 memblock_alloc(n_pmds * PTRS_PER_PMD * sizeof(pmd_t), PAGE_SIZE);
68 pgd_t *pgd = pgd_offset_k(vaddr);
69
70 for (i = 0; i < n_pages; i++) {
71 phys_addr_t phys = memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
72 set_pte(&pte[i], pfn_pte(PHYS_PFN(phys), PAGE_KERNEL));
73 }
74
75 for (i = 0, offset = 0; i < n_ptes; i++, offset += PTRS_PER_PTE)
76 set_pmd(&pmd[i],
77 pfn_pmd(PFN_DOWN(__pa(&pte[offset])),
78 __pgprot(_PAGE_TABLE)));
79
80 for (i = 0, offset = 0; i < n_pmds; i++, offset += PTRS_PER_PMD)
81 set_pgd(&pgd[i],
82 pfn_pgd(PFN_DOWN(__pa(&pmd[offset])),
83 __pgprot(_PAGE_TABLE)));
84
85 local_flush_tlb_all();
86 memset(start, 0, end - start);
87 }
88
kasan_init(void)89 void __init kasan_init(void)
90 {
91 phys_addr_t _start, _end;
92 u64 i;
93
94 kasan_populate_early_shadow((void *)KASAN_SHADOW_START,
95 (void *)kasan_mem_to_shadow((void *)
96 VMALLOC_END));
97
98 for_each_mem_range(i, &_start, &_end) {
99 void *start = (void *)__va(_start);
100 void *end = (void *)__va(_end);
101
102 if (start >= end)
103 break;
104
105 populate(kasan_mem_to_shadow(start), kasan_mem_to_shadow(end));
106 };
107
108 for (i = 0; i < PTRS_PER_PTE; i++)
109 set_pte(&kasan_early_shadow_pte[i],
110 mk_pte(virt_to_page(kasan_early_shadow_page),
111 __pgprot(_PAGE_PRESENT | _PAGE_READ |
112 _PAGE_ACCESSED)));
113
114 memset(kasan_early_shadow_page, 0, PAGE_SIZE);
115 init_task.kasan_depth = 0;
116 }
117