xref: /openbmc/linux/include/linux/kasan.h (revision dd2939ef) 
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_KASAN_H
3 #define _LINUX_KASAN_H
4 
5 #include <linux/bug.h>
6 #include <linux/kernel.h>
7 #include <linux/static_key.h>
8 #include <linux/types.h>
9 
10 struct kmem_cache;
11 struct page;
12 struct vm_struct;
13 struct task_struct;
14 
15 #ifdef CONFIG_KASAN
16 
17 #include <linux/linkage.h>
18 #include <asm/kasan.h>
19 
20 /* kasan_data struct is used in KUnit tests for KASAN expected failures */
21 struct kunit_kasan_expectation {
22 	bool report_found;
23 };
24 
25 #endif
26 
27 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
28 
29 #include <linux/pgtable.h>
30 
31 /* Software KASAN implementations use shadow memory. */
32 
33 #ifdef CONFIG_KASAN_SW_TAGS
34 /* This matches KASAN_TAG_INVALID. */
35 #define KASAN_SHADOW_INIT 0xFE
36 #else
37 #define KASAN_SHADOW_INIT 0
38 #endif
39 
40 #ifndef PTE_HWTABLE_PTRS
41 #define PTE_HWTABLE_PTRS 0
42 #endif
43 
44 extern unsigned char kasan_early_shadow_page[PAGE_SIZE];
45 extern pte_t kasan_early_shadow_pte[MAX_PTRS_PER_PTE + PTE_HWTABLE_PTRS];
46 extern pmd_t kasan_early_shadow_pmd[MAX_PTRS_PER_PMD];
47 extern pud_t kasan_early_shadow_pud[MAX_PTRS_PER_PUD];
48 extern p4d_t kasan_early_shadow_p4d[MAX_PTRS_PER_P4D];
49 
50 int kasan_populate_early_shadow(const void *shadow_start,
51 				const void *shadow_end);
52 
53 static inline void *kasan_mem_to_shadow(const void *addr)
54 {
55 	return (void *)((unsigned long)addr >> KASAN_SHADOW_SCALE_SHIFT)
56 		+ KASAN_SHADOW_OFFSET;
57 }
58 
59 int kasan_add_zero_shadow(void *start, unsigned long size);
60 void kasan_remove_zero_shadow(void *start, unsigned long size);
61 
62 /* Enable reporting bugs after kasan_disable_current() */
63 extern void kasan_enable_current(void);
64 
65 /* Disable reporting bugs for current task */
66 extern void kasan_disable_current(void);
67 
68 #else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
69 
70 static inline int kasan_add_zero_shadow(void *start, unsigned long size)
71 {
72 	return 0;
73 }
74 static inline void kasan_remove_zero_shadow(void *start,
75 					unsigned long size)
76 {}
77 
78 static inline void kasan_enable_current(void) {}
79 static inline void kasan_disable_current(void) {}
80 
81 #endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
82 
83 #ifdef CONFIG_KASAN_HW_TAGS
84 
85 DECLARE_STATIC_KEY_FALSE(kasan_flag_enabled);
86 
87 static __always_inline bool kasan_enabled(void)
88 {
89 	return static_branch_likely(&kasan_flag_enabled);
90 }
91 
92 static inline bool kasan_has_integrated_init(void)
93 {
94 	return kasan_enabled();
95 }
96 
97 void kasan_alloc_pages(struct page *page, unsigned int order, gfp_t flags);
98 void kasan_free_pages(struct page *page, unsigned int order);
99 
100 #else /* CONFIG_KASAN_HW_TAGS */
101 
102 static inline bool kasan_enabled(void)
103 {
104 	return IS_ENABLED(CONFIG_KASAN);
105 }
106 
107 static inline bool kasan_has_integrated_init(void)
108 {
109 	return false;
110 }
111 
112 static __always_inline void kasan_alloc_pages(struct page *page,
113 					      unsigned int order, gfp_t flags)
114 {
115 	/* Only available for integrated init. */
116 	BUILD_BUG();
117 }
118 
119 static __always_inline void kasan_free_pages(struct page *page,
120 					     unsigned int order)
121 {
122 	/* Only available for integrated init. */
123 	BUILD_BUG();
124 }
125 
126 #endif /* CONFIG_KASAN_HW_TAGS */
127 
128 #ifdef CONFIG_KASAN
129 
130 struct kasan_cache {
131 	int alloc_meta_offset;
132 	int free_meta_offset;
133 	bool is_kmalloc;
134 };
135 
136 slab_flags_t __kasan_never_merge(void);
137 static __always_inline slab_flags_t kasan_never_merge(void)
138 {
139 	if (kasan_enabled())
140 		return __kasan_never_merge();
141 	return 0;
142 }
143 
144 void __kasan_unpoison_range(const void *addr, size_t size);
145 static __always_inline void kasan_unpoison_range(const void *addr, size_t size)
146 {
147 	if (kasan_enabled())
148 		__kasan_unpoison_range(addr, size);
149 }
150 
151 void __kasan_poison_pages(struct page *page, unsigned int order, bool init);
152 static __always_inline void kasan_poison_pages(struct page *page,
153 						unsigned int order, bool init)
154 {
155 	if (kasan_enabled())
156 		__kasan_poison_pages(page, order, init);
157 }
158 
159 void __kasan_unpoison_pages(struct page *page, unsigned int order, bool init);
160 static __always_inline void kasan_unpoison_pages(struct page *page,
161 						 unsigned int order, bool init)
162 {
163 	if (kasan_enabled())
164 		__kasan_unpoison_pages(page, order, init);
165 }
166 
167 void __kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
168 				slab_flags_t *flags);
169 static __always_inline void kasan_cache_create(struct kmem_cache *cache,
170 				unsigned int *size, slab_flags_t *flags)
171 {
172 	if (kasan_enabled())
173 		__kasan_cache_create(cache, size, flags);
174 }
175 
176 void __kasan_cache_create_kmalloc(struct kmem_cache *cache);
177 static __always_inline void kasan_cache_create_kmalloc(struct kmem_cache *cache)
178 {
179 	if (kasan_enabled())
180 		__kasan_cache_create_kmalloc(cache);
181 }
182 
183 size_t __kasan_metadata_size(struct kmem_cache *cache);
184 static __always_inline size_t kasan_metadata_size(struct kmem_cache *cache)
185 {
186 	if (kasan_enabled())
187 		return __kasan_metadata_size(cache);
188 	return 0;
189 }
190 
191 void __kasan_poison_slab(struct page *page);
192 static __always_inline void kasan_poison_slab(struct page *page)
193 {
194 	if (kasan_enabled())
195 		__kasan_poison_slab(page);
196 }
197 
198 void __kasan_unpoison_object_data(struct kmem_cache *cache, void *object);
199 static __always_inline void kasan_unpoison_object_data(struct kmem_cache *cache,
200 							void *object)
201 {
202 	if (kasan_enabled())
203 		__kasan_unpoison_object_data(cache, object);
204 }
205 
206 void __kasan_poison_object_data(struct kmem_cache *cache, void *object);
207 static __always_inline void kasan_poison_object_data(struct kmem_cache *cache,
208 							void *object)
209 {
210 	if (kasan_enabled())
211 		__kasan_poison_object_data(cache, object);
212 }
213 
214 void * __must_check __kasan_init_slab_obj(struct kmem_cache *cache,
215 					  const void *object);
216 static __always_inline void * __must_check kasan_init_slab_obj(
217 				struct kmem_cache *cache, const void *object)
218 {
219 	if (kasan_enabled())
220 		return __kasan_init_slab_obj(cache, object);
221 	return (void *)object;
222 }
223 
224 bool __kasan_slab_free(struct kmem_cache *s, void *object,
225 			unsigned long ip, bool init);
226 static __always_inline bool kasan_slab_free(struct kmem_cache *s,
227 						void *object, bool init)
228 {
229 	if (kasan_enabled())
230 		return __kasan_slab_free(s, object, _RET_IP_, init);
231 	return false;
232 }
233 
234 void __kasan_kfree_large(void *ptr, unsigned long ip);
235 static __always_inline void kasan_kfree_large(void *ptr)
236 {
237 	if (kasan_enabled())
238 		__kasan_kfree_large(ptr, _RET_IP_);
239 }
240 
241 void __kasan_slab_free_mempool(void *ptr, unsigned long ip);
242 static __always_inline void kasan_slab_free_mempool(void *ptr)
243 {
244 	if (kasan_enabled())
245 		__kasan_slab_free_mempool(ptr, _RET_IP_);
246 }
247 
248 void * __must_check __kasan_slab_alloc(struct kmem_cache *s,
249 				       void *object, gfp_t flags, bool init);
250 static __always_inline void * __must_check kasan_slab_alloc(
251 		struct kmem_cache *s, void *object, gfp_t flags, bool init)
252 {
253 	if (kasan_enabled())
254 		return __kasan_slab_alloc(s, object, flags, init);
255 	return object;
256 }
257 
258 void * __must_check __kasan_kmalloc(struct kmem_cache *s, const void *object,
259 				    size_t size, gfp_t flags);
260 static __always_inline void * __must_check kasan_kmalloc(struct kmem_cache *s,
261 				const void *object, size_t size, gfp_t flags)
262 {
263 	if (kasan_enabled())
264 		return __kasan_kmalloc(s, object, size, flags);
265 	return (void *)object;
266 }
267 
268 void * __must_check __kasan_kmalloc_large(const void *ptr,
269 					  size_t size, gfp_t flags);
270 static __always_inline void * __must_check kasan_kmalloc_large(const void *ptr,
271 						      size_t size, gfp_t flags)
272 {
273 	if (kasan_enabled())
274 		return __kasan_kmalloc_large(ptr, size, flags);
275 	return (void *)ptr;
276 }
277 
278 void * __must_check __kasan_krealloc(const void *object,
279 				     size_t new_size, gfp_t flags);
280 static __always_inline void * __must_check kasan_krealloc(const void *object,
281 						 size_t new_size, gfp_t flags)
282 {
283 	if (kasan_enabled())
284 		return __kasan_krealloc(object, new_size, flags);
285 	return (void *)object;
286 }
287 
288 /*
289  * Unlike kasan_check_read/write(), kasan_check_byte() is performed even for
290  * the hardware tag-based mode that doesn't rely on compiler instrumentation.
291  */
292 bool __kasan_check_byte(const void *addr, unsigned long ip);
293 static __always_inline bool kasan_check_byte(const void *addr)
294 {
295 	if (kasan_enabled())
296 		return __kasan_check_byte(addr, _RET_IP_);
297 	return true;
298 }
299 
300 
301 bool kasan_save_enable_multi_shot(void);
302 void kasan_restore_multi_shot(bool enabled);
303 
304 #else /* CONFIG_KASAN */
305 
306 static inline slab_flags_t kasan_never_merge(void)
307 {
308 	return 0;
309 }
310 static inline void kasan_unpoison_range(const void *address, size_t size) {}
311 static inline void kasan_poison_pages(struct page *page, unsigned int order,
312 				      bool init) {}
313 static inline void kasan_unpoison_pages(struct page *page, unsigned int order,
314 					bool init) {}
315 static inline void kasan_cache_create(struct kmem_cache *cache,
316 				      unsigned int *size,
317 				      slab_flags_t *flags) {}
318 static inline void kasan_cache_create_kmalloc(struct kmem_cache *cache) {}
319 static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; }
320 static inline void kasan_poison_slab(struct page *page) {}
321 static inline void kasan_unpoison_object_data(struct kmem_cache *cache,
322 					void *object) {}
323 static inline void kasan_poison_object_data(struct kmem_cache *cache,
324 					void *object) {}
325 static inline void *kasan_init_slab_obj(struct kmem_cache *cache,
326 				const void *object)
327 {
328 	return (void *)object;
329 }
330 static inline bool kasan_slab_free(struct kmem_cache *s, void *object, bool init)
331 {
332 	return false;
333 }
334 static inline void kasan_kfree_large(void *ptr) {}
335 static inline void kasan_slab_free_mempool(void *ptr) {}
336 static inline void *kasan_slab_alloc(struct kmem_cache *s, void *object,
337 				   gfp_t flags, bool init)
338 {
339 	return object;
340 }
341 static inline void *kasan_kmalloc(struct kmem_cache *s, const void *object,
342 				size_t size, gfp_t flags)
343 {
344 	return (void *)object;
345 }
346 static inline void *kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags)
347 {
348 	return (void *)ptr;
349 }
350 static inline void *kasan_krealloc(const void *object, size_t new_size,
351 				 gfp_t flags)
352 {
353 	return (void *)object;
354 }
355 static inline bool kasan_check_byte(const void *address)
356 {
357 	return true;
358 }
359 
360 #endif /* CONFIG_KASAN */
361 
362 #if defined(CONFIG_KASAN) && defined(CONFIG_KASAN_STACK)
363 void kasan_unpoison_task_stack(struct task_struct *task);
364 #else
365 static inline void kasan_unpoison_task_stack(struct task_struct *task) {}
366 #endif
367 
368 #ifdef CONFIG_KASAN_GENERIC
369 
370 void kasan_cache_shrink(struct kmem_cache *cache);
371 void kasan_cache_shutdown(struct kmem_cache *cache);
372 void kasan_record_aux_stack(void *ptr);
373 
374 #else /* CONFIG_KASAN_GENERIC */
375 
376 static inline void kasan_cache_shrink(struct kmem_cache *cache) {}
377 static inline void kasan_cache_shutdown(struct kmem_cache *cache) {}
378 static inline void kasan_record_aux_stack(void *ptr) {}
379 
380 #endif /* CONFIG_KASAN_GENERIC */
381 
382 #if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
383 
384 static inline void *kasan_reset_tag(const void *addr)
385 {
386 	return (void *)arch_kasan_reset_tag(addr);
387 }
388 
389 /**
390  * kasan_report - print a report about a bad memory access detected by KASAN
391  * @addr: address of the bad access
392  * @size: size of the bad access
393  * @is_write: whether the bad access is a write or a read
394  * @ip: instruction pointer for the accessibility check or the bad access itself
395  */
396 bool kasan_report(unsigned long addr, size_t size,
397 		bool is_write, unsigned long ip);
398 
399 #else /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
400 
401 static inline void *kasan_reset_tag(const void *addr)
402 {
403 	return (void *)addr;
404 }
405 
406 #endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS*/
407 
408 #ifdef CONFIG_KASAN_HW_TAGS
409 
410 void kasan_report_async(void);
411 
412 #endif /* CONFIG_KASAN_HW_TAGS */
413 
414 #ifdef CONFIG_KASAN_SW_TAGS
415 void __init kasan_init_sw_tags(void);
416 #else
417 static inline void kasan_init_sw_tags(void) { }
418 #endif
419 
420 #ifdef CONFIG_KASAN_HW_TAGS
421 void kasan_init_hw_tags_cpu(void);
422 void __init kasan_init_hw_tags(void);
423 #else
424 static inline void kasan_init_hw_tags_cpu(void) { }
425 static inline void kasan_init_hw_tags(void) { }
426 #endif
427 
428 #ifdef CONFIG_KASAN_VMALLOC
429 
430 int kasan_populate_vmalloc(unsigned long addr, unsigned long size);
431 void kasan_poison_vmalloc(const void *start, unsigned long size);
432 void kasan_unpoison_vmalloc(const void *start, unsigned long size);
433 void kasan_release_vmalloc(unsigned long start, unsigned long end,
434 			   unsigned long free_region_start,
435 			   unsigned long free_region_end);
436 
437 #else /* CONFIG_KASAN_VMALLOC */
438 
439 static inline int kasan_populate_vmalloc(unsigned long start,
440 					unsigned long size)
441 {
442 	return 0;
443 }
444 
445 static inline void kasan_poison_vmalloc(const void *start, unsigned long size)
446 { }
447 static inline void kasan_unpoison_vmalloc(const void *start, unsigned long size)
448 { }
449 static inline void kasan_release_vmalloc(unsigned long start,
450 					 unsigned long end,
451 					 unsigned long free_region_start,
452 					 unsigned long free_region_end) {}
453 
454 #endif /* CONFIG_KASAN_VMALLOC */
455 
456 #if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \
457 		!defined(CONFIG_KASAN_VMALLOC)
458 
459 /*
460  * These functions provide a special case to support backing module
461  * allocations with real shadow memory. With KASAN vmalloc, the special
462  * case is unnecessary, as the work is handled in the generic case.
463  */
464 int kasan_module_alloc(void *addr, size_t size);
465 void kasan_free_shadow(const struct vm_struct *vm);
466 
467 #else /* (CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS) && !CONFIG_KASAN_VMALLOC */
468 
469 static inline int kasan_module_alloc(void *addr, size_t size) { return 0; }
470 static inline void kasan_free_shadow(const struct vm_struct *vm) {}
471 
472 #endif /* (CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS) && !CONFIG_KASAN_VMALLOC */
473 
474 #ifdef CONFIG_KASAN_INLINE
475 void kasan_non_canonical_hook(unsigned long addr);
476 #else /* CONFIG_KASAN_INLINE */
477 static inline void kasan_non_canonical_hook(unsigned long addr) { }
478 #endif /* CONFIG_KASAN_INLINE */
479 
480 #endif /* LINUX_KASAN_H */
481