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
222static const u64 kDefaultShadowSentinel = ~(uptr)0;
223
224# if defined(ASAN_SHADOW_OFFSET_CONST)
225static 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
253namespace __asan {
254
255extern 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.
261static uptr kHighMemEnd = 0x7fffffffffffULL;
262static uptr kMidMemBeg = 0x3000000000ULL;
263static uptr kMidMemEnd = 0x4fffffffffULL;
264# else
265extern 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
307namespace __asan {
308
309static inline bool AddrIsInLowMem(uptr a) {
310 PROFILE_ASAN_MAPPING();
311 return a <= kLowMemEnd;
312}
313
314static inline bool AddrIsInLowShadow(uptr a) {
315 PROFILE_ASAN_MAPPING();
316 return a >= kLowShadowBeg && a <= kLowShadowEnd;
317}
318
319static inline bool AddrIsInMidMem(uptr a) {
320 PROFILE_ASAN_MAPPING();
321 return kMidMemBeg && a >= kMidMemBeg && a <= kMidMemEnd;
322}
323
324static inline bool AddrIsInMidShadow(uptr a) {
325 PROFILE_ASAN_MAPPING();
326 return kMidMemBeg && a >= kMidShadowBeg && a <= kMidShadowEnd;
327}
328
329static inline bool AddrIsInHighMem(uptr a) {
330 PROFILE_ASAN_MAPPING();
331 return kHighMemBeg && a >= kHighMemBeg && a <= kHighMemEnd;
332}
333
334static inline bool AddrIsInHighShadow(uptr a) {
335 PROFILE_ASAN_MAPPING();
336 return kHighMemBeg && a >= kHighShadowBeg && a <= kHighShadowEnd;
337}
338
339static 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
358namespace __asan {
359
360static inline uptr MemToShadowSize(uptr size) {
361 return size >> ASAN_SHADOW_SCALE;
362}
363
364static 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
370static inline uptr MemToShadow(uptr p) {
371 PROFILE_ASAN_MAPPING();
372 CHECK(AddrIsInMem(p));
373 return MEM_TO_SHADOW(p);
374}
375
376static inline bool AddrIsInShadow(uptr a) {
377 PROFILE_ASAN_MAPPING();
378 return AddrIsInLowShadow(a) || AddrIsInMidShadow(a) || AddrIsInHighShadow(a);
379}
380
381static inline uptr ShadowToMem(uptr p) {
382 PROFILE_ASAN_MAPPING();
383 CHECK(AddrIsInShadow(p));
384 return SHADOW_TO_MEM(p);
385}
386
387static inline bool AddrIsAlignedByGranularity(uptr a) {
388 PROFILE_ASAN_MAPPING();
389 return (a & (ASAN_SHADOW_GRANULARITY - 1)) == 0;
390}
391
392static 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().
406static const uptr kAsanMappingProfileSize = __LINE__;
407
408} // namespace __asan
409
410#endif // __cplusplus
411
412#endif // ASAN_MAPPING_H
413

source code of compiler-rt/lib/asan/asan_mapping.h