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 with SHADOW_OFFSET == 0xd55550000;
76// (the exact location of SHADOW_OFFSET may vary depending the dynamic probing
77// by FindDynamicShadowStart).
78//
79// || `[0x1555550000, 0x3fffffffff]` || HighMem ||
80// || `[0x0fffffa000, 0x1555555fff]` || HighShadow ||
81// || `[0x0effffa000, 0x0fffff9fff]` || ShadowGap ||
82// || `[0x0d55550000, 0x0effff9fff]` || LowShadow ||
83// || `[0x0000000000, 0x0d5554ffff]` || LowMem ||
84//
85// Default Linux/AArch64 (39-bit VMA) mapping:
86// TODO: this mapping is ok, but the allocator size is too large on non-Android
87// AArch64 platforms (see asan_allocator.h)
88// || `[0x2000000000, 0x7fffffffff]` || highmem || 384GB
89// || `[0x1400000000, 0x1fffffffff]` || highshadow || 48GB
90// || `[0x1200000000, 0x13ffffffff]` || shadowgap || 8GB
91// || `[0x1000000000, 0x11ffffffff]` || lowshadow || 8GB
92// || `[0x0000000000, 0x0fffffffff]` || lowmem || 64GB
93//
94// Default Linux/AArch64 (42-bit VMA) mapping:
95// TODO: this mapping is ok, but the allocator size is too large on non-Android
96// AArch64 platforms (see asan_allocator.h)
97// || `[0x09000000000, 0x03ffffffffff]` || highmem || 3520GB
98// || `[0x02200000000, 0x008fffffffff]` || highshadow || 440GB
99// || `[0x01200000000, 0x0021ffffffff]` || shadowgap || 64GB
100// || `[0x01000000000, 0x0011ffffffff]` || lowshadow || 8GB
101// || `[0x00000000000, 0x000fffffffff]` || lowmem || 64GB
102//
103// Default Linux/AArch64 (48-bit VMA) mapping:
104// || `[0x201000000000, 0xffffffffffff]` || HighMem || 229312GB
105// || `[0x041200000000, 0x200fffffffff]` || HighShadow || 28664GB
106// || `[0x001200000000, 0x0411ffffffff]` || ShadowGap || 4096GB
107// || `[0x001000000000, 0x0011ffffffff]` || LowShadow || 8GB
108// || `[0x000000000000, 0x000fffffffff]` || LowMem || 64GB
109//
110// Default Linux/S390 mapping:
111// || `[0x30000000, 0x7fffffff]` || HighMem ||
112// || `[0x26000000, 0x2fffffff]` || HighShadow ||
113// || `[0x24000000, 0x25ffffff]` || ShadowGap ||
114// || `[0x20000000, 0x23ffffff]` || LowShadow ||
115// || `[0x00000000, 0x1fffffff]` || LowMem ||
116//
117// Default Linux/SystemZ mapping:
118// || `[0x14000000000000, 0x1fffffffffffff]` || HighMem ||
119// || `[0x12800000000000, 0x13ffffffffffff]` || HighShadow ||
120// || `[0x12000000000000, 0x127fffffffffff]` || ShadowGap ||
121// || `[0x10000000000000, 0x11ffffffffffff]` || LowShadow ||
122// || `[0x00000000000000, 0x0fffffffffffff]` || LowMem ||
123//
124// Default Linux/SPARC64 (52-bit VMA) mapping:
125// || `[0x8000000000000, 0xfffffffffffff]` || HighMem ||
126// || `[0x1080000000000, 0x207ffffffffff]` || HighShadow ||
127// || `[0x0090000000000, 0x107ffffffffff]` || ShadowGap ||
128// || `[0x0080000000000, 0x008ffffffffff]` || LowShadow ||
129// || `[0x0000000000000, 0x007ffffffffff]` || LowMem ||
130//
131// Default Linux/LoongArch64 (47-bit VMA) mapping:
132// || `[0x500000000000, 0x7fffffffffff]` || HighMem ||
133// || `[0x4a0000000000, 0x4fffffffffff]` || HighShadow ||
134// || `[0x480000000000, 0x49ffffffffff]` || ShadowGap ||
135// || `[0x400000000000, 0x47ffffffffff]` || LowShadow ||
136// || `[0x000000000000, 0x3fffffffffff]` || LowMem ||
137//
138// Shadow mapping on FreeBSD/x86-64 with SHADOW_OFFSET == 0x400000000000:
139// || `[0x500000000000, 0x7fffffffffff]` || HighMem ||
140// || `[0x4a0000000000, 0x4fffffffffff]` || HighShadow ||
141// || `[0x480000000000, 0x49ffffffffff]` || ShadowGap ||
142// || `[0x400000000000, 0x47ffffffffff]` || LowShadow ||
143// || `[0x000000000000, 0x3fffffffffff]` || LowMem ||
144//
145// Shadow mapping on FreeBSD/i386 with SHADOW_OFFSET == 0x40000000:
146// || `[0x60000000, 0xffffffff]` || HighMem ||
147// || `[0x4c000000, 0x5fffffff]` || HighShadow ||
148// || `[0x48000000, 0x4bffffff]` || ShadowGap ||
149// || `[0x40000000, 0x47ffffff]` || LowShadow ||
150// || `[0x00000000, 0x3fffffff]` || LowMem ||
151//
152// Shadow mapping on NetBSD/x86-64 with SHADOW_OFFSET == 0x400000000000:
153// || `[0x4feffffffe01, 0x7f7ffffff000]` || HighMem ||
154// || `[0x49fdffffffc0, 0x4feffffffe00]` || HighShadow ||
155// || `[0x480000000000, 0x49fdffffffbf]` || ShadowGap ||
156// || `[0x400000000000, 0x47ffffffffff]` || LowShadow ||
157// || `[0x000000000000, 0x3fffffffffff]` || LowMem ||
158//
159// Shadow mapping on NetBSD/i386 with SHADOW_OFFSET == 0x40000000:
160// || `[0x60000000, 0xfffff000]` || HighMem ||
161// || `[0x4c000000, 0x5fffffff]` || HighShadow ||
162// || `[0x48000000, 0x4bffffff]` || ShadowGap ||
163// || `[0x40000000, 0x47ffffff]` || LowShadow ||
164// || `[0x00000000, 0x3fffffff]` || LowMem ||
165//
166// Default Windows/i386 mapping:
167// (the exact location of HighShadow/HighMem may vary depending
168// on WoW64, /LARGEADDRESSAWARE, etc).
169// || `[0x50000000, 0xffffffff]` || HighMem ||
170// || `[0x3a000000, 0x4fffffff]` || HighShadow ||
171// || `[0x36000000, 0x39ffffff]` || ShadowGap ||
172// || `[0x30000000, 0x35ffffff]` || LowShadow ||
173// || `[0x00000000, 0x2fffffff]` || LowMem ||
174//
175// Default Hexagon/Linux mapping (32-bit, 4 GB VA):
176// || `[0x40000000, 0xffffffff]` || HighMem ||
177// || `[0x28000000, 0x3fffffff]` || HighShadow ||
178// || `[0x24000000, 0x27ffffff]` || ShadowGap ||
179// || `[0x20000000, 0x23ffffff]` || LowShadow ||
180// || `[0x00000000, 0x1fffffff]` || LowMem ||
181
182#define ASAN_SHADOW_SCALE 3
183
184#if SANITIZER_FUCHSIA
185# define ASAN_SHADOW_OFFSET_DYNAMIC
186#elif SANITIZER_WORDSIZE == 32
187# if SANITIZER_ANDROID
188# define ASAN_SHADOW_OFFSET_DYNAMIC
189# elif defined(__mips__)
190# define ASAN_SHADOW_OFFSET_CONST 0x0aaa0000
191# elif SANITIZER_FREEBSD
192# define ASAN_SHADOW_OFFSET_CONST 0x40000000
193# elif SANITIZER_NETBSD
194# define ASAN_SHADOW_OFFSET_CONST 0x40000000
195# elif SANITIZER_WINDOWS
196# define ASAN_SHADOW_OFFSET_CONST 0x30000000
197# elif SANITIZER_IOS
198# define ASAN_SHADOW_OFFSET_DYNAMIC
199# elif SANITIZER_AIX
200# define ASAN_SHADOW_OFFSET_CONST 0x40000000
201# elif defined(__hexagon__)
202# define ASAN_SHADOW_OFFSET_CONST 0x20000000
203# else
204# define ASAN_SHADOW_OFFSET_CONST 0x20000000
205# endif
206#else
207# if SANITIZER_IOS
208# define ASAN_SHADOW_OFFSET_DYNAMIC
209# elif SANITIZER_APPLE && defined(__aarch64__)
210# define ASAN_SHADOW_OFFSET_DYNAMIC
211# elif SANITIZER_FREEBSD && defined(__aarch64__)
212# define ASAN_SHADOW_OFFSET_CONST 0x0000800000000000
213# elif SANITIZER_RISCV64
214# define ASAN_SHADOW_OFFSET_DYNAMIC
215# elif SANITIZER_ALPHA
216# define ASAN_SHADOW_OFFSET_CONST 0x70000000000
217# elif defined(__aarch64__)
218# define ASAN_SHADOW_OFFSET_CONST 0x0000001000000000
219# elif defined(__powerpc64__)
220# if SANITIZER_AIX
221# define ASAN_SHADOW_OFFSET_CONST 0x0a01000000000000
222# else
223# define ASAN_SHADOW_OFFSET_CONST 0x0000100000000000
224# endif
225# elif defined(__s390x__)
226# define ASAN_SHADOW_OFFSET_CONST 0x0010000000000000
227# elif SANITIZER_FREEBSD
228# define ASAN_SHADOW_OFFSET_CONST 0x0000400000000000
229# elif SANITIZER_NETBSD
230# define ASAN_SHADOW_OFFSET_CONST 0x0000400000000000
231# elif SANITIZER_APPLE
232# define ASAN_SHADOW_OFFSET_CONST 0x0000100000000000
233# elif defined(__mips64)
234# define ASAN_SHADOW_OFFSET_CONST 0x0000002000000000
235# elif defined(__sparc__)
236# define ASAN_SHADOW_OFFSET_CONST 0x0000080000000000
237# elif SANITIZER_LOONGARCH64
238# define ASAN_SHADOW_OFFSET_CONST 0x0000400000000000
239# elif SANITIZER_WINDOWS64
240# define ASAN_SHADOW_OFFSET_DYNAMIC
241# else
242# if ASAN_SHADOW_SCALE != 3
243# error "Value below is based on shadow scale = 3."
244# error "Original formula was: 0x7FFFFFFF & (~0xFFFULL << SHADOW_SCALE)."
245# endif
246# define ASAN_SHADOW_OFFSET_CONST 0x000000007fff8000
247# endif
248#endif
249
250#if defined(__cplusplus)
251# include "asan_internal.h"
252
253static const u64 kDefaultShadowSentinel = ~(uptr)0;
254
255# if defined(ASAN_SHADOW_OFFSET_CONST)
256static const u64 kConstShadowOffset = ASAN_SHADOW_OFFSET_CONST;
257# define ASAN_SHADOW_OFFSET kConstShadowOffset
258# elif defined(ASAN_SHADOW_OFFSET_DYNAMIC)
259# define ASAN_SHADOW_OFFSET __asan_shadow_memory_dynamic_address
260# else
261# error "ASAN_SHADOW_OFFSET can't be determined."
262# endif
263
264# if SANITIZER_ANDROID && defined(__arm__)
265# define ASAN_PREMAP_SHADOW 1
266# else
267# define ASAN_PREMAP_SHADOW 0
268# endif
269
270# define ASAN_SHADOW_GRANULARITY (1ULL << ASAN_SHADOW_SCALE)
271
272# define DO_ASAN_MAPPING_PROFILE 0 // Set to 1 to profile the functions below.
273
274# if DO_ASAN_MAPPING_PROFILE
275# define PROFILE_ASAN_MAPPING() AsanMappingProfile[__LINE__]++;
276# else
277# define PROFILE_ASAN_MAPPING()
278# endif
279
280// If 1, all shadow boundaries are constants.
281// Don't set to 1 other than for testing.
282# define ASAN_FIXED_MAPPING 0
283
284namespace __asan {
285
286extern uptr AsanMappingProfile[];
287
288# if ASAN_FIXED_MAPPING
289// Fixed mapping for 64-bit Linux. Mostly used for performance comparison
290// with non-fixed mapping. As of r175253 (Feb 2013) the performance
291// difference between fixed and non-fixed mapping is below the noise level.
292static uptr kHighMemEnd = 0x7fffffffffffULL;
293static uptr kMidMemBeg = 0x3000000000ULL;
294static uptr kMidMemEnd = 0x4fffffffffULL;
295# else
296extern uptr kHighMemEnd, kMidMemBeg, kMidMemEnd; // Initialized in __asan_init.
297# endif
298
299} // namespace __asan
300
301# if defined(__sparc__) && SANITIZER_WORDSIZE == 64
302# include "asan_mapping_sparc64.h"
303# elif SANITIZER_AIX && SANITIZER_WORDSIZE == 64
304# include "asan_mapping_aix64.h"
305# else
306# define MEM_TO_SHADOW(mem) \
307 ((STRIP_MTE_TAG(mem) >> ASAN_SHADOW_SCALE) + (ASAN_SHADOW_OFFSET))
308# define SHADOW_TO_MEM(mem) \
309 (((mem) - (ASAN_SHADOW_OFFSET)) << (ASAN_SHADOW_SCALE))
310
311# define kLowMemBeg 0
312# define kLowMemEnd (ASAN_SHADOW_OFFSET ? ASAN_SHADOW_OFFSET - 1 : 0)
313
314# define kLowShadowBeg ASAN_SHADOW_OFFSET
315# define kLowShadowEnd MEM_TO_SHADOW(kLowMemEnd)
316
317# define kHighMemBeg (MEM_TO_SHADOW(kHighMemEnd) + 1)
318
319# define kHighShadowBeg MEM_TO_SHADOW(kHighMemBeg)
320# define kHighShadowEnd MEM_TO_SHADOW(kHighMemEnd)
321
322# define kMidShadowBeg MEM_TO_SHADOW(kMidMemBeg)
323# define kMidShadowEnd MEM_TO_SHADOW(kMidMemEnd)
324
325// If the first byte of shadow can be placed after the last byte of app mem,
326// we don't need a gap since the shadow's shadow won't be in the middle
327// of app mem.
328# if SANITIZER_APPLE
329# define kGaplessShadow (kLowShadowBeg > kHighMemEnd)
330# else
331# define kGaplessShadow (false)
332# endif
333
334// With the zero shadow base we can not actually map pages starting from 0.
335// This constant is somewhat arbitrary.
336# define kZeroBaseShadowStart 0
337# define kZeroBaseMaxShadowStart (1 << 18)
338
339# define kShadowGapBeg \
340 (kLowShadowEnd ? kLowShadowEnd + 1 : kZeroBaseShadowStart)
341# define kShadowGapEnd ((kMidMemBeg ? kMidShadowBeg : kHighShadowBeg) - 1)
342
343# define kShadowGap2Beg (kMidMemBeg ? kMidShadowEnd + 1 : 0)
344# define kShadowGap2End (kMidMemBeg ? kMidMemBeg - 1 : 0)
345
346# define kShadowGap3Beg (kMidMemBeg ? kMidMemEnd + 1 : 0)
347# define kShadowGap3End (kMidMemBeg ? kHighShadowBeg - 1 : 0)
348
349namespace __asan {
350
351static inline bool AddrIsInLowMem(uptr a) {
352 PROFILE_ASAN_MAPPING();
353 return a <= kLowMemEnd;
354}
355
356static inline bool AddrIsInLowShadow(uptr a) {
357 PROFILE_ASAN_MAPPING();
358 return a >= kLowShadowBeg && a <= kLowShadowEnd;
359}
360
361static inline bool AddrIsInMidMem(uptr a) {
362 PROFILE_ASAN_MAPPING();
363 return kMidMemBeg && a >= kMidMemBeg && a <= kMidMemEnd;
364}
365
366static inline bool AddrIsInMidShadow(uptr a) {
367 PROFILE_ASAN_MAPPING();
368 return kMidMemBeg && a >= kMidShadowBeg && a <= kMidShadowEnd;
369}
370
371static inline bool AddrIsInHighMem(uptr a) {
372 PROFILE_ASAN_MAPPING();
373 return kHighMemBeg && a >= kHighMemBeg && a <= kHighMemEnd;
374}
375
376static inline bool AddrIsInHighShadow(uptr a) {
377 PROFILE_ASAN_MAPPING();
378 return kHighMemBeg && a >= kHighShadowBeg && a <= kHighShadowEnd;
379}
380
381static inline bool AddrIsInShadowGap(uptr a) {
382 PROFILE_ASAN_MAPPING();
383 if (kMidMemBeg) {
384 if (a <= kShadowGapEnd)
385 return ASAN_SHADOW_OFFSET == 0 || a >= kShadowGapBeg;
386 return (a >= kShadowGap2Beg && a <= kShadowGap2End) ||
387 (a >= kShadowGap3Beg && a <= kShadowGap3End);
388 }
389 // In zero-based shadow mode we treat addresses near zero as addresses
390 // in shadow gap as well.
391 if (ASAN_SHADOW_OFFSET == 0)
392 return a <= kShadowGapEnd;
393 return a >= kShadowGapBeg && a <= kShadowGapEnd;
394}
395
396} // namespace __asan
397
398# endif
399
400namespace __asan {
401
402static inline uptr MemToShadowSize(uptr size) {
403 return size >> ASAN_SHADOW_SCALE;
404}
405
406static inline bool AddrIsInMem(uptr a) {
407 PROFILE_ASAN_MAPPING();
408 a = STRIP_MTE_TAG(a);
409 return AddrIsInLowMem(a) || AddrIsInMidMem(a) || AddrIsInHighMem(a) ||
410 (flags()->protect_shadow_gap == 0 && AddrIsInShadowGap(a));
411}
412
413static inline uptr MemToShadow(uptr p) {
414 PROFILE_ASAN_MAPPING();
415 CHECK(AddrIsInMem(p));
416 return MEM_TO_SHADOW(p);
417}
418
419static inline bool AddrIsInShadow(uptr a) {
420 PROFILE_ASAN_MAPPING();
421 a = STRIP_MTE_TAG(a);
422 return AddrIsInLowShadow(a) || AddrIsInMidShadow(a) || AddrIsInHighShadow(a);
423}
424
425static inline uptr ShadowToMem(uptr p) {
426 PROFILE_ASAN_MAPPING();
427 CHECK(AddrIsInShadow(p));
428 return SHADOW_TO_MEM(p);
429}
430
431static inline bool AddrIsAlignedByGranularity(uptr a) {
432 PROFILE_ASAN_MAPPING();
433 return (a & (ASAN_SHADOW_GRANULARITY - 1)) == 0;
434}
435
436static inline bool AddressIsPoisoned(uptr a) {
437 PROFILE_ASAN_MAPPING();
438 const uptr kAccessSize = 1;
439 u8 *shadow_address = (u8 *)MEM_TO_SHADOW(a);
440 s8 shadow_value = *shadow_address;
441 if (shadow_value) {
442 u8 last_accessed_byte =
443 (a & (ASAN_SHADOW_GRANULARITY - 1)) + kAccessSize - 1;
444 return (last_accessed_byte >= shadow_value);
445 }
446 return false;
447}
448
449// Must be after all calls to PROFILE_ASAN_MAPPING().
450static const uptr kAsanMappingProfileSize = __LINE__;
451
452} // namespace __asan
453
454#endif // __cplusplus
455
456#endif // ASAN_MAPPING_H
457