1 //===-- asan_mapping.h ------------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file is a part of AddressSanitizer, an address sanity checker.
10 //
11 // Defines ASan memory mapping.
12 //===----------------------------------------------------------------------===//
13 #ifndef ASAN_MAPPING_H
14 #define ASAN_MAPPING_H
15
16 #include "sanitizer_common/sanitizer_platform.h"
17
18 // The full explanation of the memory mapping could be found here:
19 // https://github.com/google/sanitizers/wiki/AddressSanitizerAlgorithm
20 //
21 // Typical shadow mapping on Linux/x86_64 with SHADOW_OFFSET == 0x00007fff8000:
22 // || `[0x10007fff8000, 0x7fffffffffff]` || HighMem ||
23 // || `[0x02008fff7000, 0x10007fff7fff]` || HighShadow ||
24 // || `[0x00008fff7000, 0x02008fff6fff]` || ShadowGap ||
25 // || `[0x00007fff8000, 0x00008fff6fff]` || LowShadow ||
26 // || `[0x000000000000, 0x00007fff7fff]` || LowMem ||
27 //
28 // When SHADOW_OFFSET is zero (-pie):
29 // || `[0x100000000000, 0x7fffffffffff]` || HighMem ||
30 // || `[0x020000000000, 0x0fffffffffff]` || HighShadow ||
31 // || `[0x000000040000, 0x01ffffffffff]` || ShadowGap ||
32 //
33 // Special case when something is already mapped between
34 // 0x003000000000 and 0x005000000000 (e.g. when prelink is installed):
35 // || `[0x10007fff8000, 0x7fffffffffff]` || HighMem ||
36 // || `[0x02008fff7000, 0x10007fff7fff]` || HighShadow ||
37 // || `[0x005000000000, 0x02008fff6fff]` || ShadowGap3 ||
38 // || `[0x003000000000, 0x004fffffffff]` || MidMem ||
39 // || `[0x000a7fff8000, 0x002fffffffff]` || ShadowGap2 ||
40 // || `[0x00067fff8000, 0x000a7fff7fff]` || MidShadow ||
41 // || `[0x00008fff7000, 0x00067fff7fff]` || ShadowGap ||
42 // || `[0x00007fff8000, 0x00008fff6fff]` || LowShadow ||
43 // || `[0x000000000000, 0x00007fff7fff]` || LowMem ||
44 //
45 // Default Linux/i386 mapping on x86_64 machine:
46 // || `[0x40000000, 0xffffffff]` || HighMem ||
47 // || `[0x28000000, 0x3fffffff]` || HighShadow ||
48 // || `[0x24000000, 0x27ffffff]` || ShadowGap ||
49 // || `[0x20000000, 0x23ffffff]` || LowShadow ||
50 // || `[0x00000000, 0x1fffffff]` || LowMem ||
51 //
52 // Default Linux/i386 mapping on i386 machine
53 // (addresses starting with 0xc0000000 are reserved
54 // for kernel and thus not sanitized):
55 // || `[0x38000000, 0xbfffffff]` || HighMem ||
56 // || `[0x27000000, 0x37ffffff]` || HighShadow ||
57 // || `[0x24000000, 0x26ffffff]` || ShadowGap ||
58 // || `[0x20000000, 0x23ffffff]` || LowShadow ||
59 // || `[0x00000000, 0x1fffffff]` || LowMem ||
60 //
61 // Default Linux/MIPS32 mapping:
62 // || `[0x2aaa0000, 0xffffffff]` || HighMem ||
63 // || `[0x0fff4000, 0x2aa9ffff]` || HighShadow ||
64 // || `[0x0bff4000, 0x0fff3fff]` || ShadowGap ||
65 // || `[0x0aaa0000, 0x0bff3fff]` || LowShadow ||
66 // || `[0x00000000, 0x0aa9ffff]` || LowMem ||
67 //
68 // Default Linux/MIPS64 mapping:
69 // || `[0x4000000000, 0xffffffffff]` || HighMem ||
70 // || `[0x2800000000, 0x3fffffffff]` || HighShadow ||
71 // || `[0x2400000000, 0x27ffffffff]` || ShadowGap ||
72 // || `[0x2000000000, 0x23ffffffff]` || LowShadow ||
73 // || `[0x0000000000, 0x1fffffffff]` || LowMem ||
74 //
75 // Default Linux/RISCV64 Sv39 mapping:
76 // || `[0x1555550000, 0x3fffffffff]` || HighMem ||
77 // || `[0x0fffffa000, 0x1555555fff]` || HighShadow ||
78 // || `[0x0effffa000, 0x0fffff9fff]` || ShadowGap ||
79 // || `[0x0d55550000, 0x0effff9fff]` || LowShadow ||
80 // || `[0x0000000000, 0x0d5554ffff]` || LowMem ||
81 //
82 // Default Linux/AArch64 (39-bit VMA) mapping:
83 // || `[0x2000000000, 0x7fffffffff]` || highmem ||
84 // || `[0x1400000000, 0x1fffffffff]` || highshadow ||
85 // || `[0x1200000000, 0x13ffffffff]` || shadowgap ||
86 // || `[0x1000000000, 0x11ffffffff]` || lowshadow ||
87 // || `[0x0000000000, 0x0fffffffff]` || lowmem ||
88 //
89 // Default Linux/AArch64 (42-bit VMA) mapping:
90 // || `[0x10000000000, 0x3ffffffffff]` || highmem ||
91 // || `[0x0a000000000, 0x0ffffffffff]` || highshadow ||
92 // || `[0x09000000000, 0x09fffffffff]` || shadowgap ||
93 // || `[0x08000000000, 0x08fffffffff]` || lowshadow ||
94 // || `[0x00000000000, 0x07fffffffff]` || lowmem ||
95 //
96 // Default Linux/S390 mapping:
97 // || `[0x30000000, 0x7fffffff]` || HighMem ||
98 // || `[0x26000000, 0x2fffffff]` || HighShadow ||
99 // || `[0x24000000, 0x25ffffff]` || ShadowGap ||
100 // || `[0x20000000, 0x23ffffff]` || LowShadow ||
101 // || `[0x00000000, 0x1fffffff]` || LowMem ||
102 //
103 // Default Linux/SystemZ mapping:
104 // || `[0x14000000000000, 0x1fffffffffffff]` || HighMem ||
105 // || `[0x12800000000000, 0x13ffffffffffff]` || HighShadow ||
106 // || `[0x12000000000000, 0x127fffffffffff]` || ShadowGap ||
107 // || `[0x10000000000000, 0x11ffffffffffff]` || LowShadow ||
108 // || `[0x00000000000000, 0x0fffffffffffff]` || LowMem ||
109 //
110 // Default Linux/SPARC64 (52-bit VMA) mapping:
111 // || `[0x8000000000000, 0xfffffffffffff]` || HighMem ||
112 // || `[0x1080000000000, 0x207ffffffffff]` || HighShadow ||
113 // || `[0x0090000000000, 0x107ffffffffff]` || ShadowGap ||
114 // || `[0x0080000000000, 0x008ffffffffff]` || LowShadow ||
115 // || `[0x0000000000000, 0x007ffffffffff]` || LowMem ||
116 //
117 // Default Linux/LoongArch64 (47-bit VMA) mapping:
118 // || `[0x500000000000, 0x7fffffffffff]` || HighMem ||
119 // || `[0x4a0000000000, 0x4fffffffffff]` || HighShadow ||
120 // || `[0x480000000000, 0x49ffffffffff]` || ShadowGap ||
121 // || `[0x400000000000, 0x47ffffffffff]` || LowShadow ||
122 // || `[0x000000000000, 0x3fffffffffff]` || LowMem ||
123 //
124 // Shadow mapping on FreeBSD/x86-64 with SHADOW_OFFSET == 0x400000000000:
125 // || `[0x500000000000, 0x7fffffffffff]` || HighMem ||
126 // || `[0x4a0000000000, 0x4fffffffffff]` || HighShadow ||
127 // || `[0x480000000000, 0x49ffffffffff]` || ShadowGap ||
128 // || `[0x400000000000, 0x47ffffffffff]` || LowShadow ||
129 // || `[0x000000000000, 0x3fffffffffff]` || LowMem ||
130 //
131 // Shadow mapping on FreeBSD/i386 with SHADOW_OFFSET == 0x40000000:
132 // || `[0x60000000, 0xffffffff]` || HighMem ||
133 // || `[0x4c000000, 0x5fffffff]` || HighShadow ||
134 // || `[0x48000000, 0x4bffffff]` || ShadowGap ||
135 // || `[0x40000000, 0x47ffffff]` || LowShadow ||
136 // || `[0x00000000, 0x3fffffff]` || LowMem ||
137 //
138 // Shadow mapping on NetBSD/x86-64 with SHADOW_OFFSET == 0x400000000000:
139 // || `[0x4feffffffe01, 0x7f7ffffff000]` || HighMem ||
140 // || `[0x49fdffffffc0, 0x4feffffffe00]` || HighShadow ||
141 // || `[0x480000000000, 0x49fdffffffbf]` || ShadowGap ||
142 // || `[0x400000000000, 0x47ffffffffff]` || LowShadow ||
143 // || `[0x000000000000, 0x3fffffffffff]` || LowMem ||
144 //
145 // Shadow mapping on NetBSD/i386 with SHADOW_OFFSET == 0x40000000:
146 // || `[0x60000000, 0xfffff000]` || HighMem ||
147 // || `[0x4c000000, 0x5fffffff]` || HighShadow ||
148 // || `[0x48000000, 0x4bffffff]` || ShadowGap ||
149 // || `[0x40000000, 0x47ffffff]` || LowShadow ||
150 // || `[0x00000000, 0x3fffffff]` || LowMem ||
151 //
152 // Default Windows/i386 mapping:
153 // (the exact location of HighShadow/HighMem may vary depending
154 // on WoW64, /LARGEADDRESSAWARE, etc).
155 // || `[0x50000000, 0xffffffff]` || HighMem ||
156 // || `[0x3a000000, 0x4fffffff]` || HighShadow ||
157 // || `[0x36000000, 0x39ffffff]` || ShadowGap ||
158 // || `[0x30000000, 0x35ffffff]` || LowShadow ||
159 // || `[0x00000000, 0x2fffffff]` || LowMem ||
160
161 #define ASAN_SHADOW_SCALE 3
162
163 #if SANITIZER_FUCHSIA
164 # define ASAN_SHADOW_OFFSET_CONST (0)
165 #elif SANITIZER_WORDSIZE == 32
166 # if SANITIZER_ANDROID
167 # define ASAN_SHADOW_OFFSET_DYNAMIC
168 # elif defined(__mips__)
169 # define ASAN_SHADOW_OFFSET_CONST 0x0aaa0000
170 # elif SANITIZER_FREEBSD
171 # define ASAN_SHADOW_OFFSET_CONST 0x40000000
172 # elif SANITIZER_NETBSD
173 # define ASAN_SHADOW_OFFSET_CONST 0x40000000
174 # elif SANITIZER_WINDOWS
175 # define ASAN_SHADOW_OFFSET_CONST 0x30000000
176 # elif SANITIZER_IOS
177 # define ASAN_SHADOW_OFFSET_DYNAMIC
178 # else
179 # define ASAN_SHADOW_OFFSET_CONST 0x20000000
180 # endif
181 #else
182 # if SANITIZER_IOS
183 # define ASAN_SHADOW_OFFSET_DYNAMIC
184 # elif SANITIZER_APPLE && defined(__aarch64__)
185 # define ASAN_SHADOW_OFFSET_DYNAMIC
186 # elif SANITIZER_FREEBSD && defined(__aarch64__)
187 # define ASAN_SHADOW_OFFSET_CONST 0x0000800000000000
188 # elif SANITIZER_RISCV64
189 # define ASAN_SHADOW_OFFSET_CONST 0x0000000d55550000
190 # elif defined(__aarch64__)
191 # define ASAN_SHADOW_OFFSET_CONST 0x0000001000000000
192 # elif defined(__powerpc64__)
193 # define ASAN_SHADOW_OFFSET_CONST 0x0000100000000000
194 # elif defined(__s390x__)
195 # define ASAN_SHADOW_OFFSET_CONST 0x0010000000000000
196 # elif SANITIZER_FREEBSD
197 # define ASAN_SHADOW_OFFSET_CONST 0x0000400000000000
198 # elif SANITIZER_NETBSD
199 # define ASAN_SHADOW_OFFSET_CONST 0x0000400000000000
200 # elif SANITIZER_APPLE
201 # define ASAN_SHADOW_OFFSET_CONST 0x0000100000000000
202 # elif defined(__mips64)
203 # define ASAN_SHADOW_OFFSET_CONST 0x0000002000000000
204 # elif defined(__sparc__)
205 # define ASAN_SHADOW_OFFSET_CONST 0x0000080000000000
206 # elif SANITIZER_LOONGARCH64
207 # define ASAN_SHADOW_OFFSET_CONST 0x0000400000000000
208 # elif SANITIZER_WINDOWS64
209 # define ASAN_SHADOW_OFFSET_DYNAMIC
210 # else
211 # if ASAN_SHADOW_SCALE != 3
212 # error "Value below is based on shadow scale = 3."
213 # error "Original formula was: 0x7FFFFFFF & (~0xFFFULL << SHADOW_SCALE)."
214 # endif
215 # define ASAN_SHADOW_OFFSET_CONST 0x000000007fff8000
216 # endif
217 #endif
218
219 #if defined(__cplusplus)
220 # include "asan_internal.h"
221
222 static const u64 kDefaultShadowSentinel = ~(uptr)0;
223
224 # if defined(ASAN_SHADOW_OFFSET_CONST)
225 static const u64 kConstShadowOffset = ASAN_SHADOW_OFFSET_CONST;
226 # define ASAN_SHADOW_OFFSET kConstShadowOffset
227 # elif defined(ASAN_SHADOW_OFFSET_DYNAMIC)
228 # define ASAN_SHADOW_OFFSET __asan_shadow_memory_dynamic_address
229 # else
230 # error "ASAN_SHADOW_OFFSET can't be determined."
231 # endif
232
233 # if SANITIZER_ANDROID && defined(__arm__)
234 # define ASAN_PREMAP_SHADOW 1
235 # else
236 # define ASAN_PREMAP_SHADOW 0
237 # endif
238
239 # define ASAN_SHADOW_GRANULARITY (1ULL << ASAN_SHADOW_SCALE)
240
241 # define DO_ASAN_MAPPING_PROFILE 0 // Set to 1 to profile the functions below.
242
243 # if DO_ASAN_MAPPING_PROFILE
244 # define PROFILE_ASAN_MAPPING() AsanMappingProfile[__LINE__]++;
245 # else
246 # define PROFILE_ASAN_MAPPING()
247 # endif
248
249 // If 1, all shadow boundaries are constants.
250 // Don't set to 1 other than for testing.
251 # define ASAN_FIXED_MAPPING 0
252
253 namespace __asan {
254
255 extern uptr AsanMappingProfile[];
256
257 # if ASAN_FIXED_MAPPING
258 // Fixed mapping for 64-bit Linux. Mostly used for performance comparison
259 // with non-fixed mapping. As of r175253 (Feb 2013) the performance
260 // difference between fixed and non-fixed mapping is below the noise level.
261 static uptr kHighMemEnd = 0x7fffffffffffULL;
262 static uptr kMidMemBeg = 0x3000000000ULL;
263 static uptr kMidMemEnd = 0x4fffffffffULL;
264 # else
265 extern uptr kHighMemEnd, kMidMemBeg, kMidMemEnd; // Initialized in __asan_init.
266 # endif
267
268 } // namespace __asan
269
270 # if defined(__sparc__) && SANITIZER_WORDSIZE == 64
271 # include "asan_mapping_sparc64.h"
272 # else
273 # define MEM_TO_SHADOW(mem) \
274 (((mem) >> ASAN_SHADOW_SCALE) + (ASAN_SHADOW_OFFSET))
275 # define SHADOW_TO_MEM(mem) \
276 (((mem) - (ASAN_SHADOW_OFFSET)) << (ASAN_SHADOW_SCALE))
277
278 # define kLowMemBeg 0
279 # define kLowMemEnd (ASAN_SHADOW_OFFSET ? ASAN_SHADOW_OFFSET - 1 : 0)
280
281 # define kLowShadowBeg ASAN_SHADOW_OFFSET
282 # define kLowShadowEnd MEM_TO_SHADOW(kLowMemEnd)
283
284 # define kHighMemBeg (MEM_TO_SHADOW(kHighMemEnd) + 1)
285
286 # define kHighShadowBeg MEM_TO_SHADOW(kHighMemBeg)
287 # define kHighShadowEnd MEM_TO_SHADOW(kHighMemEnd)
288
289 # define kMidShadowBeg MEM_TO_SHADOW(kMidMemBeg)
290 # define kMidShadowEnd MEM_TO_SHADOW(kMidMemEnd)
291
292 // With the zero shadow base we can not actually map pages starting from 0.
293 // This constant is somewhat arbitrary.
294 # define kZeroBaseShadowStart 0
295 # define kZeroBaseMaxShadowStart (1 << 18)
296
297 # define kShadowGapBeg \
298 (kLowShadowEnd ? kLowShadowEnd + 1 : kZeroBaseShadowStart)
299 # define kShadowGapEnd ((kMidMemBeg ? kMidShadowBeg : kHighShadowBeg) - 1)
300
301 # define kShadowGap2Beg (kMidMemBeg ? kMidShadowEnd + 1 : 0)
302 # define kShadowGap2End (kMidMemBeg ? kMidMemBeg - 1 : 0)
303
304 # define kShadowGap3Beg (kMidMemBeg ? kMidMemEnd + 1 : 0)
305 # define kShadowGap3End (kMidMemBeg ? kHighShadowBeg - 1 : 0)
306
307 namespace __asan {
308
AddrIsInLowMem(uptr a)309 static inline bool AddrIsInLowMem(uptr a) {
310 PROFILE_ASAN_MAPPING();
311 return a <= kLowMemEnd;
312 }
313
AddrIsInLowShadow(uptr a)314 static inline bool AddrIsInLowShadow(uptr a) {
315 PROFILE_ASAN_MAPPING();
316 return a >= kLowShadowBeg && a <= kLowShadowEnd;
317 }
318
AddrIsInMidMem(uptr a)319 static inline bool AddrIsInMidMem(uptr a) {
320 PROFILE_ASAN_MAPPING();
321 return kMidMemBeg && a >= kMidMemBeg && a <= kMidMemEnd;
322 }
323
AddrIsInMidShadow(uptr a)324 static inline bool AddrIsInMidShadow(uptr a) {
325 PROFILE_ASAN_MAPPING();
326 return kMidMemBeg && a >= kMidShadowBeg && a <= kMidShadowEnd;
327 }
328
AddrIsInHighMem(uptr a)329 static inline bool AddrIsInHighMem(uptr a) {
330 PROFILE_ASAN_MAPPING();
331 return kHighMemBeg && a >= kHighMemBeg && a <= kHighMemEnd;
332 }
333
AddrIsInHighShadow(uptr a)334 static inline bool AddrIsInHighShadow(uptr a) {
335 PROFILE_ASAN_MAPPING();
336 return kHighMemBeg && a >= kHighShadowBeg && a <= kHighShadowEnd;
337 }
338
AddrIsInShadowGap(uptr a)339 static inline bool AddrIsInShadowGap(uptr a) {
340 PROFILE_ASAN_MAPPING();
341 if (kMidMemBeg) {
342 if (a <= kShadowGapEnd)
343 return ASAN_SHADOW_OFFSET == 0 || a >= kShadowGapBeg;
344 return (a >= kShadowGap2Beg && a <= kShadowGap2End) ||
345 (a >= kShadowGap3Beg && a <= kShadowGap3End);
346 }
347 // In zero-based shadow mode we treat addresses near zero as addresses
348 // in shadow gap as well.
349 if (ASAN_SHADOW_OFFSET == 0)
350 return a <= kShadowGapEnd;
351 return a >= kShadowGapBeg && a <= kShadowGapEnd;
352 }
353
354 } // namespace __asan
355
356 # endif
357
358 namespace __asan {
359
MemToShadowSize(uptr size)360 static inline uptr MemToShadowSize(uptr size) {
361 return size >> ASAN_SHADOW_SCALE;
362 }
363
AddrIsInMem(uptr a)364 static inline bool AddrIsInMem(uptr a) {
365 PROFILE_ASAN_MAPPING();
366 return AddrIsInLowMem(a) || AddrIsInMidMem(a) || AddrIsInHighMem(a) ||
367 (flags()->protect_shadow_gap == 0 && AddrIsInShadowGap(a));
368 }
369
MemToShadow(uptr p)370 static inline uptr MemToShadow(uptr p) {
371 PROFILE_ASAN_MAPPING();
372 CHECK(AddrIsInMem(p));
373 return MEM_TO_SHADOW(p);
374 }
375
AddrIsInShadow(uptr a)376 static inline bool AddrIsInShadow(uptr a) {
377 PROFILE_ASAN_MAPPING();
378 return AddrIsInLowShadow(a) || AddrIsInMidShadow(a) || AddrIsInHighShadow(a);
379 }
380
ShadowToMem(uptr p)381 static inline uptr ShadowToMem(uptr p) {
382 PROFILE_ASAN_MAPPING();
383 CHECK(AddrIsInShadow(p));
384 return SHADOW_TO_MEM(p);
385 }
386
AddrIsAlignedByGranularity(uptr a)387 static inline bool AddrIsAlignedByGranularity(uptr a) {
388 PROFILE_ASAN_MAPPING();
389 return (a & (ASAN_SHADOW_GRANULARITY - 1)) == 0;
390 }
391
AddressIsPoisoned(uptr a)392 static inline bool AddressIsPoisoned(uptr a) {
393 PROFILE_ASAN_MAPPING();
394 const uptr kAccessSize = 1;
395 u8 *shadow_address = (u8 *)MEM_TO_SHADOW(a);
396 s8 shadow_value = *shadow_address;
397 if (shadow_value) {
398 u8 last_accessed_byte =
399 (a & (ASAN_SHADOW_GRANULARITY - 1)) + kAccessSize - 1;
400 return (last_accessed_byte >= shadow_value);
401 }
402 return false;
403 }
404
405 // Must be after all calls to PROFILE_ASAN_MAPPING().
406 static const uptr kAsanMappingProfileSize = __LINE__;
407
408 } // namespace __asan
409
410 #endif // __cplusplus
411
412 #endif // ASAN_MAPPING_H
413