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17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18#define DISABLE_BRANCH_PROFILING
19
20#include <linux/export.h>
21#include <linux/interrupt.h>
22#include <linux/init.h>
23#include <linux/kasan.h>
24#include <linux/kernel.h>
25#include <linux/kmemleak.h>
26#include <linux/linkage.h>
27#include <linux/memblock.h>
28#include <linux/memory.h>
29#include <linux/mm.h>
30#include <linux/module.h>
31#include <linux/printk.h>
32#include <linux/sched.h>
33#include <linux/sched/task_stack.h>
34#include <linux/slab.h>
35#include <linux/stacktrace.h>
36#include <linux/string.h>
37#include <linux/types.h>
38#include <linux/vmalloc.h>
39#include <linux/bug.h>
40
41#include "kasan.h"
42#include "../slab.h"
43
44
45
46
47
48
49
50static __always_inline bool memory_is_poisoned_1(unsigned long addr)
51{
52 s8 shadow_value = *(s8 *)kasan_mem_to_shadow((void *)addr);
53
54 if (unlikely(shadow_value)) {
55 s8 last_accessible_byte = addr & KASAN_SHADOW_MASK;
56 return unlikely(last_accessible_byte >= shadow_value);
57 }
58
59 return false;
60}
61
62static __always_inline bool memory_is_poisoned_2_4_8(unsigned long addr,
63 unsigned long size)
64{
65 u8 *shadow_addr = (u8 *)kasan_mem_to_shadow((void *)addr);
66
67
68
69
70
71 if (unlikely(((addr + size - 1) & KASAN_SHADOW_MASK) < size - 1))
72 return *shadow_addr || memory_is_poisoned_1(addr + size - 1);
73
74 return memory_is_poisoned_1(addr + size - 1);
75}
76
77static __always_inline bool memory_is_poisoned_16(unsigned long addr)
78{
79 u16 *shadow_addr = (u16 *)kasan_mem_to_shadow((void *)addr);
80
81
82 if (unlikely(!IS_ALIGNED(addr, KASAN_SHADOW_SCALE_SIZE)))
83 return *shadow_addr || memory_is_poisoned_1(addr + 15);
84
85 return *shadow_addr;
86}
87
88static __always_inline unsigned long bytes_is_nonzero(const u8 *start,
89 size_t size)
90{
91 while (size) {
92 if (unlikely(*start))
93 return (unsigned long)start;
94 start++;
95 size--;
96 }
97
98 return 0;
99}
100
101static __always_inline unsigned long memory_is_nonzero(const void *start,
102 const void *end)
103{
104 unsigned int words;
105 unsigned long ret;
106 unsigned int prefix = (unsigned long)start % 8;
107
108 if (end - start <= 16)
109 return bytes_is_nonzero(start, end - start);
110
111 if (prefix) {
112 prefix = 8 - prefix;
113 ret = bytes_is_nonzero(start, prefix);
114 if (unlikely(ret))
115 return ret;
116 start += prefix;
117 }
118
119 words = (end - start) / 8;
120 while (words) {
121 if (unlikely(*(u64 *)start))
122 return bytes_is_nonzero(start, 8);
123 start += 8;
124 words--;
125 }
126
127 return bytes_is_nonzero(start, (end - start) % 8);
128}
129
130static __always_inline bool memory_is_poisoned_n(unsigned long addr,
131 size_t size)
132{
133 unsigned long ret;
134
135 ret = memory_is_nonzero(kasan_mem_to_shadow((void *)addr),
136 kasan_mem_to_shadow((void *)addr + size - 1) + 1);
137
138 if (unlikely(ret)) {
139 unsigned long last_byte = addr + size - 1;
140 s8 *last_shadow = (s8 *)kasan_mem_to_shadow((void *)last_byte);
141
142 if (unlikely(ret != (unsigned long)last_shadow ||
143 ((long)(last_byte & KASAN_SHADOW_MASK) >= *last_shadow)))
144 return true;
145 }
146 return false;
147}
148
149static __always_inline bool memory_is_poisoned(unsigned long addr, size_t size)
150{
151 if (__builtin_constant_p(size)) {
152 switch (size) {
153 case 1:
154 return memory_is_poisoned_1(addr);
155 case 2:
156 case 4:
157 case 8:
158 return memory_is_poisoned_2_4_8(addr, size);
159 case 16:
160 return memory_is_poisoned_16(addr);
161 default:
162 BUILD_BUG();
163 }
164 }
165
166 return memory_is_poisoned_n(addr, size);
167}
168
169static __always_inline bool check_memory_region_inline(unsigned long addr,
170 size_t size, bool write,
171 unsigned long ret_ip)
172{
173 if (unlikely(size == 0))
174 return true;
175
176 if (unlikely((void *)addr <
177 kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) {
178 kasan_report(addr, size, write, ret_ip);
179 return false;
180 }
181
182 if (likely(!memory_is_poisoned(addr, size)))
183 return true;
184
185 kasan_report(addr, size, write, ret_ip);
186 return false;
187}
188
189bool check_memory_region(unsigned long addr, size_t size, bool write,
190 unsigned long ret_ip)
191{
192 return check_memory_region_inline(addr, size, write, ret_ip);
193}
194
195void kasan_cache_shrink(struct kmem_cache *cache)
196{
197 quarantine_remove_cache(cache);
198}
199
200void kasan_cache_shutdown(struct kmem_cache *cache)
201{
202 if (!__kmem_cache_empty(cache))
203 quarantine_remove_cache(cache);
204}
205
206static void register_global(struct kasan_global *global)
207{
208 size_t aligned_size = round_up(global->size, KASAN_SHADOW_SCALE_SIZE);
209
210 kasan_unpoison_shadow(global->beg, global->size);
211
212 kasan_poison_shadow(global->beg + aligned_size,
213 global->size_with_redzone - aligned_size,
214 KASAN_GLOBAL_REDZONE);
215}
216
217void __asan_register_globals(struct kasan_global *globals, size_t size)
218{
219 int i;
220
221 for (i = 0; i < size; i++)
222 register_global(&globals[i]);
223}
224EXPORT_SYMBOL(__asan_register_globals);
225
226void __asan_unregister_globals(struct kasan_global *globals, size_t size)
227{
228}
229EXPORT_SYMBOL(__asan_unregister_globals);
230
231#define DEFINE_ASAN_LOAD_STORE(size) \
232 void __asan_load##size(unsigned long addr) \
233 { \
234 check_memory_region_inline(addr, size, false, _RET_IP_);\
235 } \
236 EXPORT_SYMBOL(__asan_load##size); \
237 __alias(__asan_load##size) \
238 void __asan_load##size##_noabort(unsigned long); \
239 EXPORT_SYMBOL(__asan_load##size##_noabort); \
240 void __asan_store##size(unsigned long addr) \
241 { \
242 check_memory_region_inline(addr, size, true, _RET_IP_); \
243 } \
244 EXPORT_SYMBOL(__asan_store##size); \
245 __alias(__asan_store##size) \
246 void __asan_store##size##_noabort(unsigned long); \
247 EXPORT_SYMBOL(__asan_store##size##_noabort)
248
249DEFINE_ASAN_LOAD_STORE(1);
250DEFINE_ASAN_LOAD_STORE(2);
251DEFINE_ASAN_LOAD_STORE(4);
252DEFINE_ASAN_LOAD_STORE(8);
253DEFINE_ASAN_LOAD_STORE(16);
254
255void __asan_loadN(unsigned long addr, size_t size)
256{
257 check_memory_region(addr, size, false, _RET_IP_);
258}
259EXPORT_SYMBOL(__asan_loadN);
260
261__alias(__asan_loadN)
262void __asan_loadN_noabort(unsigned long, size_t);
263EXPORT_SYMBOL(__asan_loadN_noabort);
264
265void __asan_storeN(unsigned long addr, size_t size)
266{
267 check_memory_region(addr, size, true, _RET_IP_);
268}
269EXPORT_SYMBOL(__asan_storeN);
270
271__alias(__asan_storeN)
272void __asan_storeN_noabort(unsigned long, size_t);
273EXPORT_SYMBOL(__asan_storeN_noabort);
274
275
276void __asan_handle_no_return(void) {}
277EXPORT_SYMBOL(__asan_handle_no_return);
278
279
280void __asan_alloca_poison(unsigned long addr, size_t size)
281{
282 size_t rounded_up_size = round_up(size, KASAN_SHADOW_SCALE_SIZE);
283 size_t padding_size = round_up(size, KASAN_ALLOCA_REDZONE_SIZE) -
284 rounded_up_size;
285 size_t rounded_down_size = round_down(size, KASAN_SHADOW_SCALE_SIZE);
286
287 const void *left_redzone = (const void *)(addr -
288 KASAN_ALLOCA_REDZONE_SIZE);
289 const void *right_redzone = (const void *)(addr + rounded_up_size);
290
291 WARN_ON(!IS_ALIGNED(addr, KASAN_ALLOCA_REDZONE_SIZE));
292
293 kasan_unpoison_shadow((const void *)(addr + rounded_down_size),
294 size - rounded_down_size);
295 kasan_poison_shadow(left_redzone, KASAN_ALLOCA_REDZONE_SIZE,
296 KASAN_ALLOCA_LEFT);
297 kasan_poison_shadow(right_redzone,
298 padding_size + KASAN_ALLOCA_REDZONE_SIZE,
299 KASAN_ALLOCA_RIGHT);
300}
301EXPORT_SYMBOL(__asan_alloca_poison);
302
303
304void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom)
305{
306 if (unlikely(!stack_top || stack_top > stack_bottom))
307 return;
308
309 kasan_unpoison_shadow(stack_top, stack_bottom - stack_top);
310}
311EXPORT_SYMBOL(__asan_allocas_unpoison);
312
313
314#define DEFINE_ASAN_SET_SHADOW(byte) \
315 void __asan_set_shadow_##byte(const void *addr, size_t size) \
316 { \
317 __memset((void *)addr, 0x##byte, size); \
318 } \
319 EXPORT_SYMBOL(__asan_set_shadow_##byte)
320
321DEFINE_ASAN_SET_SHADOW(00);
322DEFINE_ASAN_SET_SHADOW(f1);
323DEFINE_ASAN_SET_SHADOW(f2);
324DEFINE_ASAN_SET_SHADOW(f3);
325DEFINE_ASAN_SET_SHADOW(f5);
326DEFINE_ASAN_SET_SHADOW(f8);
327
