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
9static int __init
10kasan_init_shadow_8M(unsigned long k_start, unsigned long k_end, void *block)
11{
12	pmd_t *pmd = pmd_off_k(k_start);
13	unsigned long k_cur, k_next;
14
15	for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd += 2, block += SZ_8M) {
16		pte_basic_t *new;
17
18		k_next = pgd_addr_end(k_cur, k_end);
19		k_next = pgd_addr_end(k_next, k_end);
20		if ((void *)pmd_page_vaddr(*pmd) != kasan_early_shadow_pte)
21			continue;
22
23		new = memblock_alloc(sizeof(pte_basic_t), SZ_4K);
24		if (!new)
25			return -ENOMEM;
26
27		*new = pte_val(pte_mkhuge(pfn_pte(PHYS_PFN(__pa(block)), PAGE_KERNEL)));
28
29		hugepd_populate_kernel((hugepd_t *)pmd, (pte_t *)new, PAGE_SHIFT_8M);
30		hugepd_populate_kernel((hugepd_t *)pmd + 1, (pte_t *)new, PAGE_SHIFT_8M);
31	}
32	return 0;
33}
34
35int __init kasan_init_region(void *start, size_t size)
36{
37	unsigned long k_start = (unsigned long)kasan_mem_to_shadow(start);
38	unsigned long k_end = (unsigned long)kasan_mem_to_shadow(start + size);
39	unsigned long k_cur;
40	int ret;
41	void *block;
42
43	block = memblock_alloc(k_end - k_start, SZ_8M);
44	if (!block)
45		return -ENOMEM;
46
47	if (IS_ALIGNED(k_start, SZ_8M)) {
48		kasan_init_shadow_8M(k_start, ALIGN_DOWN(k_end, SZ_8M), block);
49		k_cur = ALIGN_DOWN(k_end, SZ_8M);
50		if (k_cur == k_end)
51			goto finish;
52	} else {
53		k_cur = k_start;
54	}
55
56	ret = kasan_init_shadow_page_tables(k_start, k_end);
57	if (ret)
58		return ret;
59
60	for (; k_cur < k_end; k_cur += PAGE_SIZE) {
61		pmd_t *pmd = pmd_off_k(k_cur);
62		void *va = block + k_cur - k_start;
63		pte_t pte = pfn_pte(PHYS_PFN(__pa(va)), PAGE_KERNEL);
64
65		if (k_cur < ALIGN_DOWN(k_end, SZ_512K))
66			pte = pte_mkhuge(pte);
67
68		__set_pte_at(&init_mm, k_cur, pte_offset_kernel(pmd, k_cur), pte, 0);
69	}
70finish:
71	flush_tlb_kernel_range(k_start, k_end);
72	return 0;
73}
74