8xx.c

 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
11static int __init
12kasan_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
40int __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	}
75finish:
76	flush_tlb_kernel_range(k_start, k_end);
77	return 0;
78}