xref: /openbmc/linux/arch/powerpc/mm/kasan/8xx.c (revision 842ed298)
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 static int __init
10 kasan_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 
35 int __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 	}
70 finish:
71 	flush_tlb_kernel_range(k_start, k_end);
72 	return 0;
73 }
74