1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
|
// SPDX-License-Identifier: GPL-2.0
#define DISABLE_BRANCH_PROFILING
#include <linux/kasan.h>
#include <linux/printk.h>
#include <linux/memblock.h>
#include <linux/sched/task.h>
#include <asm/pgalloc.h>
#include <asm/code-patching.h>
#include <mm/mmu_decl.h>
static pgprot_t __init kasan_prot_ro(void)
{
if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE))
return PAGE_READONLY;
return PAGE_KERNEL_RO;
}
static void __init kasan_populate_pte(pte_t *ptep, pgprot_t prot)
{
unsigned long va = (unsigned long)kasan_early_shadow_page;
phys_addr_t pa = __pa(kasan_early_shadow_page);
int i;
for (i = 0; i < PTRS_PER_PTE; i++, ptep++)
__set_pte_at(&init_mm, va, ptep, pfn_pte(PHYS_PFN(pa), prot), 1);
}
int __init kasan_init_shadow_page_tables(unsigned long k_start, unsigned long k_end)
{
pmd_t *pmd;
unsigned long k_cur, k_next;
pmd = pmd_off_k(k_start);
for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd++) {
pte_t *new;
k_next = pgd_addr_end(k_cur, k_end);
if ((void *)pmd_page_vaddr(*pmd) != kasan_early_shadow_pte)
continue;
new = memblock_alloc(PTE_FRAG_SIZE, PTE_FRAG_SIZE);
if (!new)
return -ENOMEM;
kasan_populate_pte(new, PAGE_KERNEL);
pmd_populate_kernel(&init_mm, pmd, new);
}
return 0;
}
int __init __weak kasan_init_region(void *start, size_t size)
{
unsigned long k_start = (unsigned long)kasan_mem_to_shadow(start);
unsigned long k_end = (unsigned long)kasan_mem_to_shadow(start + size);
unsigned long k_cur;
int ret;
void *block;
ret = kasan_init_shadow_page_tables(k_start, k_end);
if (ret)
return ret;
k_start = k_start & PAGE_MASK;
block = memblock_alloc(k_end - k_start, PAGE_SIZE);
if (!block)
return -ENOMEM;
for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
pmd_t *pmd = pmd_off_k(k_cur);
void *va = block + k_cur - k_start;
pte_t pte = pfn_pte(PHYS_PFN(__pa(va)), PAGE_KERNEL);
__set_pte_at(&init_mm, k_cur, pte_offset_kernel(pmd, k_cur), pte, 0);
}
flush_tlb_kernel_range(k_start, k_end);
return 0;
}
void __init
kasan_update_early_region(unsigned long k_start, unsigned long k_end, pte_t pte)
{
unsigned long k_cur;
for (k_cur = k_start; k_cur != k_end; k_cur += PAGE_SIZE) {
pmd_t *pmd = pmd_off_k(k_cur);
pte_t *ptep = pte_offset_kernel(pmd, k_cur);
if (pte_page(*ptep) != virt_to_page(lm_alias(kasan_early_shadow_page)))
continue;
__set_pte_at(&init_mm, k_cur, ptep, pte, 0);
}
flush_tlb_kernel_range(k_start, k_end);
}
static void __init kasan_remap_early_shadow_ro(void)
{
pgprot_t prot = kasan_prot_ro();
phys_addr_t pa = __pa(kasan_early_shadow_page);
kasan_populate_pte(kasan_early_shadow_pte, prot);
kasan_update_early_region(KASAN_SHADOW_START, KASAN_SHADOW_END,
pfn_pte(PHYS_PFN(pa), prot));
}
static void __init kasan_unmap_early_shadow_vmalloc(void)
{
unsigned long k_start = (unsigned long)kasan_mem_to_shadow((void *)VMALLOC_START);
unsigned long k_end = (unsigned long)kasan_mem_to_shadow((void *)VMALLOC_END);
kasan_update_early_region(k_start, k_end, __pte(0));
#ifdef MODULES_VADDR
k_start = (unsigned long)kasan_mem_to_shadow((void *)MODULES_VADDR);
k_end = (unsigned long)kasan_mem_to_shadow((void *)MODULES_END);
kasan_update_early_region(k_start, k_end, __pte(0));
#endif
}
void __init kasan_mmu_init(void)
{
int ret;
if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE)) {
ret = kasan_init_shadow_page_tables(KASAN_SHADOW_START, KASAN_SHADOW_END);
if (ret)
panic("kasan: kasan_init_shadow_page_tables() failed");
}
}
void __init kasan_init(void)
{
phys_addr_t base, end;
u64 i;
int ret;
for_each_mem_range(i, &base, &end) {
phys_addr_t top = min(end, total_lowmem);
if (base >= top)
continue;
ret = kasan_init_region(__va(base), top - base);
if (ret)
panic("kasan: kasan_init_region() failed");
}
if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) {
ret = kasan_init_shadow_page_tables(KASAN_SHADOW_START, KASAN_SHADOW_END);
if (ret)
panic("kasan: kasan_init_shadow_page_tables() failed");
}
kasan_remap_early_shadow_ro();
clear_page(kasan_early_shadow_page);
/* At this point kasan is fully initialized. Enable error messages */
init_task.kasan_depth = 0;
pr_info("KASAN init done\n");
}
void __init kasan_late_init(void)
{
if (IS_ENABLED(CONFIG_KASAN_VMALLOC))
kasan_unmap_early_shadow_vmalloc();
}
void __init kasan_early_init(void)
{
unsigned long addr = KASAN_SHADOW_START;
unsigned long end = KASAN_SHADOW_END;
unsigned long next;
pmd_t *pmd = pmd_off_k(addr);
BUILD_BUG_ON(KASAN_SHADOW_START & ~PGDIR_MASK);
kasan_populate_pte(kasan_early_shadow_pte, PAGE_KERNEL);
do {
next = pgd_addr_end(addr, end);
pmd_populate_kernel(&init_mm, pmd, kasan_early_shadow_pte);
} while (pmd++, addr = next, addr != end);
}
|
