xref: /openbmc/linux/arch/powerpc/mm/kasan/8xx.c (revision 55fd7e02)
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 #include <asm/pgalloc.h>
9 
10 static int __init
11 kasan_init_shadow_8M(unsigned long k_start, unsigned long k_end, void *block)
12 {
13 	pmd_t *pmd = pmd_off_k(k_start);
14 	unsigned long k_cur, k_next;
15 
16 	for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd += 2, block += SZ_8M) {
17 		pte_basic_t *new;
18 
19 		k_next = pgd_addr_end(k_cur, k_end);
20 		k_next = pgd_addr_end(k_next, k_end);
21 		if ((void *)pmd_page_vaddr(*pmd) != kasan_early_shadow_pte)
22 			continue;
23 
24 		new = memblock_alloc(sizeof(pte_basic_t), SZ_4K);
25 		if (!new)
26 			return -ENOMEM;
27 
28 		*new = pte_val(pte_mkhuge(pfn_pte(PHYS_PFN(__pa(block)), PAGE_KERNEL)));
29 
30 		hugepd_populate_kernel((hugepd_t *)pmd, (pte_t *)new, PAGE_SHIFT_8M);
31 		hugepd_populate_kernel((hugepd_t *)pmd + 1, (pte_t *)new, PAGE_SHIFT_8M);
32 	}
33 	return 0;
34 }
35 
36 int __init kasan_init_region(void *start, size_t size)
37 {
38 	unsigned long k_start = (unsigned long)kasan_mem_to_shadow(start);
39 	unsigned long k_end = (unsigned long)kasan_mem_to_shadow(start + size);
40 	unsigned long k_cur;
41 	int ret;
42 	void *block;
43 
44 	block = memblock_alloc(k_end - k_start, SZ_8M);
45 	if (!block)
46 		return -ENOMEM;
47 
48 	if (IS_ALIGNED(k_start, SZ_8M)) {
49 		kasan_init_shadow_8M(k_start, ALIGN_DOWN(k_end, SZ_8M), block);
50 		k_cur = ALIGN_DOWN(k_end, SZ_8M);
51 		if (k_cur == k_end)
52 			goto finish;
53 	} else {
54 		k_cur = k_start;
55 	}
56 
57 	ret = kasan_init_shadow_page_tables(k_start, k_end);
58 	if (ret)
59 		return ret;
60 
61 	for (; k_cur < k_end; k_cur += PAGE_SIZE) {
62 		pmd_t *pmd = pmd_off_k(k_cur);
63 		void *va = block + k_cur - k_start;
64 		pte_t pte = pfn_pte(PHYS_PFN(__pa(va)), PAGE_KERNEL);
65 
66 		if (k_cur < ALIGN_DOWN(k_end, SZ_512K))
67 			pte = pte_mkhuge(pte);
68 
69 		__set_pte_at(&init_mm, k_cur, pte_offset_kernel(pmd, k_cur), pte, 0);
70 	}
71 finish:
72 	flush_tlb_kernel_range(k_start, k_end);
73 	return 0;
74 }
75