xref: /openbmc/linux/include/linux/kasan.h (revision 7e5b06b8) 
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_hw_tags_enabled(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_hw_tags_enabled(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 static inline bool kasan_has_integrated_init(void)
129 {
130 	return kasan_hw_tags_enabled();
131 }
132 
133 #ifdef CONFIG_KASAN
134 
135 struct kasan_cache {
136 	int alloc_meta_offset;
137 	int free_meta_offset;
138 	bool is_kmalloc;
139 };
140 
141 slab_flags_t __kasan_never_merge(void);
142 static __always_inline slab_flags_t kasan_never_merge(void)
143 {
144 	if (kasan_enabled())
145 		return __kasan_never_merge();
146 	return 0;
147 }
148 
149 void __kasan_unpoison_range(const void *addr, size_t size);
150 static __always_inline void kasan_unpoison_range(const void *addr, size_t size)
151 {
152 	if (kasan_enabled())
153 		__kasan_unpoison_range(addr, size);
154 }
155 
156 void __kasan_poison_pages(struct page *page, unsigned int order, bool init);
157 static __always_inline void kasan_poison_pages(struct page *page,
158 						unsigned int order, bool init)
159 {
160 	if (kasan_enabled())
161 		__kasan_poison_pages(page, order, init);
162 }
163 
164 void __kasan_unpoison_pages(struct page *page, unsigned int order, bool init);
165 static __always_inline void kasan_unpoison_pages(struct page *page,
166 						 unsigned int order, bool init)
167 {
168 	if (kasan_enabled())
169 		__kasan_unpoison_pages(page, order, init);
170 }
171 
172 void __kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
173 				slab_flags_t *flags);
174 static __always_inline void kasan_cache_create(struct kmem_cache *cache,
175 				unsigned int *size, slab_flags_t *flags)
176 {
177 	if (kasan_enabled())
178 		__kasan_cache_create(cache, size, flags);
179 }
180 
181 void __kasan_cache_create_kmalloc(struct kmem_cache *cache);
182 static __always_inline void kasan_cache_create_kmalloc(struct kmem_cache *cache)
183 {
184 	if (kasan_enabled())
185 		__kasan_cache_create_kmalloc(cache);
186 }
187 
188 size_t __kasan_metadata_size(struct kmem_cache *cache);
189 static __always_inline size_t kasan_metadata_size(struct kmem_cache *cache)
190 {
191 	if (kasan_enabled())
192 		return __kasan_metadata_size(cache);
193 	return 0;
194 }
195 
196 void __kasan_poison_slab(struct page *page);
197 static __always_inline void kasan_poison_slab(struct page *page)
198 {
199 	if (kasan_enabled())
200 		__kasan_poison_slab(page);
201 }
202 
203 void __kasan_unpoison_object_data(struct kmem_cache *cache, void *object);
204 static __always_inline void kasan_unpoison_object_data(struct kmem_cache *cache,
205 							void *object)
206 {
207 	if (kasan_enabled())
208 		__kasan_unpoison_object_data(cache, object);
209 }
210 
211 void __kasan_poison_object_data(struct kmem_cache *cache, void *object);
212 static __always_inline void kasan_poison_object_data(struct kmem_cache *cache,
213 							void *object)
214 {
215 	if (kasan_enabled())
216 		__kasan_poison_object_data(cache, object);
217 }
218 
219 void * __must_check __kasan_init_slab_obj(struct kmem_cache *cache,
220 					  const void *object);
221 static __always_inline void * __must_check kasan_init_slab_obj(
222 				struct kmem_cache *cache, const void *object)
223 {
224 	if (kasan_enabled())
225 		return __kasan_init_slab_obj(cache, object);
226 	return (void *)object;
227 }
228 
229 bool __kasan_slab_free(struct kmem_cache *s, void *object,
230 			unsigned long ip, bool init);
231 static __always_inline bool kasan_slab_free(struct kmem_cache *s,
232 						void *object, bool init)
233 {
234 	if (kasan_enabled())
235 		return __kasan_slab_free(s, object, _RET_IP_, init);
236 	return false;
237 }
238 
239 void __kasan_kfree_large(void *ptr, unsigned long ip);
240 static __always_inline void kasan_kfree_large(void *ptr)
241 {
242 	if (kasan_enabled())
243 		__kasan_kfree_large(ptr, _RET_IP_);
244 }
245 
246 void __kasan_slab_free_mempool(void *ptr, unsigned long ip);
247 static __always_inline void kasan_slab_free_mempool(void *ptr)
248 {
249 	if (kasan_enabled())
250 		__kasan_slab_free_mempool(ptr, _RET_IP_);
251 }
252 
253 void * __must_check __kasan_slab_alloc(struct kmem_cache *s,
254 				       void *object, gfp_t flags, bool init);
255 static __always_inline void * __must_check kasan_slab_alloc(
256 		struct kmem_cache *s, void *object, gfp_t flags, bool init)
257 {
258 	if (kasan_enabled())
259 		return __kasan_slab_alloc(s, object, flags, init);
260 	return object;
261 }
262 
263 void * __must_check __kasan_kmalloc(struct kmem_cache *s, const void *object,
264 				    size_t size, gfp_t flags);
265 static __always_inline void * __must_check kasan_kmalloc(struct kmem_cache *s,
266 				const void *object, size_t size, gfp_t flags)
267 {
268 	if (kasan_enabled())
269 		return __kasan_kmalloc(s, object, size, flags);
270 	return (void *)object;
271 }
272 
273 void * __must_check __kasan_kmalloc_large(const void *ptr,
274 					  size_t size, gfp_t flags);
275 static __always_inline void * __must_check kasan_kmalloc_large(const void *ptr,
276 						      size_t size, gfp_t flags)
277 {
278 	if (kasan_enabled())
279 		return __kasan_kmalloc_large(ptr, size, flags);
280 	return (void *)ptr;
281 }
282 
283 void * __must_check __kasan_krealloc(const void *object,
284 				     size_t new_size, gfp_t flags);
285 static __always_inline void * __must_check kasan_krealloc(const void *object,
286 						 size_t new_size, gfp_t flags)
287 {
288 	if (kasan_enabled())
289 		return __kasan_krealloc(object, new_size, flags);
290 	return (void *)object;
291 }
292 
293 /*
294  * Unlike kasan_check_read/write(), kasan_check_byte() is performed even for
295  * the hardware tag-based mode that doesn't rely on compiler instrumentation.
296  */
297 bool __kasan_check_byte(const void *addr, unsigned long ip);
298 static __always_inline bool kasan_check_byte(const void *addr)
299 {
300 	if (kasan_enabled())
301 		return __kasan_check_byte(addr, _RET_IP_);
302 	return true;
303 }
304 
305 
306 bool kasan_save_enable_multi_shot(void);
307 void kasan_restore_multi_shot(bool enabled);
308 
309 #else /* CONFIG_KASAN */
310 
311 static inline slab_flags_t kasan_never_merge(void)
312 {
313 	return 0;
314 }
315 static inline void kasan_unpoison_range(const void *address, size_t size) {}
316 static inline void kasan_poison_pages(struct page *page, unsigned int order,
317 				      bool init) {}
318 static inline void kasan_unpoison_pages(struct page *page, unsigned int order,
319 					bool init) {}
320 static inline void kasan_cache_create(struct kmem_cache *cache,
321 				      unsigned int *size,
322 				      slab_flags_t *flags) {}
323 static inline void kasan_cache_create_kmalloc(struct kmem_cache *cache) {}
324 static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; }
325 static inline void kasan_poison_slab(struct page *page) {}
326 static inline void kasan_unpoison_object_data(struct kmem_cache *cache,
327 					void *object) {}
328 static inline void kasan_poison_object_data(struct kmem_cache *cache,
329 					void *object) {}
330 static inline void *kasan_init_slab_obj(struct kmem_cache *cache,
331 				const void *object)
332 {
333 	return (void *)object;
334 }
335 static inline bool kasan_slab_free(struct kmem_cache *s, void *object, bool init)
336 {
337 	return false;
338 }
339 static inline void kasan_kfree_large(void *ptr) {}
340 static inline void kasan_slab_free_mempool(void *ptr) {}
341 static inline void *kasan_slab_alloc(struct kmem_cache *s, void *object,
342 				   gfp_t flags, bool init)
343 {
344 	return object;
345 }
346 static inline void *kasan_kmalloc(struct kmem_cache *s, const void *object,
347 				size_t size, gfp_t flags)
348 {
349 	return (void *)object;
350 }
351 static inline void *kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags)
352 {
353 	return (void *)ptr;
354 }
355 static inline void *kasan_krealloc(const void *object, size_t new_size,
356 				 gfp_t flags)
357 {
358 	return (void *)object;
359 }
360 static inline bool kasan_check_byte(const void *address)
361 {
362 	return true;
363 }
364 
365 #endif /* CONFIG_KASAN */
366 
367 #if defined(CONFIG_KASAN) && defined(CONFIG_KASAN_STACK)
368 void kasan_unpoison_task_stack(struct task_struct *task);
369 #else
370 static inline void kasan_unpoison_task_stack(struct task_struct *task) {}
371 #endif
372 
373 #ifdef CONFIG_KASAN_GENERIC
374 
375 void kasan_cache_shrink(struct kmem_cache *cache);
376 void kasan_cache_shutdown(struct kmem_cache *cache);
377 void kasan_record_aux_stack(void *ptr);
378 void kasan_record_aux_stack_noalloc(void *ptr);
379 
380 #else /* CONFIG_KASAN_GENERIC */
381 
382 static inline void kasan_cache_shrink(struct kmem_cache *cache) {}
383 static inline void kasan_cache_shutdown(struct kmem_cache *cache) {}
384 static inline void kasan_record_aux_stack(void *ptr) {}
385 static inline void kasan_record_aux_stack_noalloc(void *ptr) {}
386 
387 #endif /* CONFIG_KASAN_GENERIC */
388 
389 #if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
390 
391 static inline void *kasan_reset_tag(const void *addr)
392 {
393 	return (void *)arch_kasan_reset_tag(addr);
394 }
395 
396 /**
397  * kasan_report - print a report about a bad memory access detected by KASAN
398  * @addr: address of the bad access
399  * @size: size of the bad access
400  * @is_write: whether the bad access is a write or a read
401  * @ip: instruction pointer for the accessibility check or the bad access itself
402  */
403 bool kasan_report(unsigned long addr, size_t size,
404 		bool is_write, unsigned long ip);
405 
406 #else /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
407 
408 static inline void *kasan_reset_tag(const void *addr)
409 {
410 	return (void *)addr;
411 }
412 
413 #endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS*/
414 
415 #ifdef CONFIG_KASAN_HW_TAGS
416 
417 void kasan_report_async(void);
418 
419 #endif /* CONFIG_KASAN_HW_TAGS */
420 
421 #ifdef CONFIG_KASAN_SW_TAGS
422 void __init kasan_init_sw_tags(void);
423 #else
424 static inline void kasan_init_sw_tags(void) { }
425 #endif
426 
427 #ifdef CONFIG_KASAN_HW_TAGS
428 void kasan_init_hw_tags_cpu(void);
429 void __init kasan_init_hw_tags(void);
430 #else
431 static inline void kasan_init_hw_tags_cpu(void) { }
432 static inline void kasan_init_hw_tags(void) { }
433 #endif
434 
435 #ifdef CONFIG_KASAN_VMALLOC
436 
437 int kasan_populate_vmalloc(unsigned long addr, unsigned long size);
438 void kasan_poison_vmalloc(const void *start, unsigned long size);
439 void kasan_unpoison_vmalloc(const void *start, unsigned long size);
440 void kasan_release_vmalloc(unsigned long start, unsigned long end,
441 			   unsigned long free_region_start,
442 			   unsigned long free_region_end);
443 
444 void kasan_populate_early_vm_area_shadow(void *start, unsigned long size);
445 
446 #else /* CONFIG_KASAN_VMALLOC */
447 
448 static inline int kasan_populate_vmalloc(unsigned long start,
449 					unsigned long size)
450 {
451 	return 0;
452 }
453 
454 static inline void kasan_poison_vmalloc(const void *start, unsigned long size)
455 { }
456 static inline void kasan_unpoison_vmalloc(const void *start, unsigned long size)
457 { }
458 static inline void kasan_release_vmalloc(unsigned long start,
459 					 unsigned long end,
460 					 unsigned long free_region_start,
461 					 unsigned long free_region_end) {}
462 
463 static inline void kasan_populate_early_vm_area_shadow(void *start,
464 						       unsigned long size)
465 { }
466 
467 #endif /* CONFIG_KASAN_VMALLOC */
468 
469 #if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \
470 		!defined(CONFIG_KASAN_VMALLOC)
471 
472 /*
473  * These functions provide a special case to support backing module
474  * allocations with real shadow memory. With KASAN vmalloc, the special
475  * case is unnecessary, as the work is handled in the generic case.
476  */
477 int kasan_module_alloc(void *addr, size_t size);
478 void kasan_free_shadow(const struct vm_struct *vm);
479 
480 #else /* (CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS) && !CONFIG_KASAN_VMALLOC */
481 
482 static inline int kasan_module_alloc(void *addr, size_t size) { return 0; }
483 static inline void kasan_free_shadow(const struct vm_struct *vm) {}
484 
485 #endif /* (CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS) && !CONFIG_KASAN_VMALLOC */
486 
487 #ifdef CONFIG_KASAN_INLINE
488 void kasan_non_canonical_hook(unsigned long addr);
489 #else /* CONFIG_KASAN_INLINE */
490 static inline void kasan_non_canonical_hook(unsigned long addr) { }
491 #endif /* CONFIG_KASAN_INLINE */
492 
493 #endif /* LINUX_KASAN_H */
494