1//===-- hwasan.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 HWAddressSanitizer.
10//
11// Private Hwasan header.
12//===----------------------------------------------------------------------===//
13
14#ifndef HWASAN_H
15#define HWASAN_H
16
17#include "hwasan_flags.h"
18#include "hwasan_interface_internal.h"
19#include "hwasan_mapping.h"
20#include "sanitizer_common/sanitizer_common.h"
21#include "sanitizer_common/sanitizer_flags.h"
22#include "sanitizer_common/sanitizer_internal_defs.h"
23#include "sanitizer_common/sanitizer_stacktrace.h"
24#include "ubsan/ubsan_platform.h"
25
26#ifndef HWASAN_CONTAINS_UBSAN
27# define HWASAN_CONTAINS_UBSAN CAN_SANITIZE_UB
28#endif
29
30#ifndef HWASAN_WITH_INTERCEPTORS
31#define HWASAN_WITH_INTERCEPTORS 0
32#endif
33
34#ifndef HWASAN_REPLACE_OPERATORS_NEW_AND_DELETE
35#define HWASAN_REPLACE_OPERATORS_NEW_AND_DELETE HWASAN_WITH_INTERCEPTORS
36#endif
37
38typedef u8 tag_t;
39
40#if defined(HWASAN_ALIASING_MODE)
41# if !defined(__x86_64__)
42# error Aliasing mode is only supported on x86_64
43# endif
44// Tags are done in middle bits using userspace aliasing.
45constexpr unsigned kAddressTagShift = 39;
46constexpr unsigned kTagBits = 3;
47
48// The alias region is placed next to the shadow so the upper bits of all
49// taggable addresses matches the upper bits of the shadow base. This shift
50// value determines which upper bits must match. It has a floor of 44 since the
51// shadow is always 8TB.
52// TODO(morehouse): In alias mode we can shrink the shadow and use a
53// simpler/faster shadow calculation.
54constexpr unsigned kTaggableRegionCheckShift =
55 __sanitizer::Max(kAddressTagShift + kTagBits + 1U, 44U);
56#elif defined(__x86_64__)
57// Tags are done in upper bits using Intel LAM.
58constexpr unsigned kAddressTagShift = 57;
59constexpr unsigned kTagBits = 6;
60#else
61// TBI (Top Byte Ignore) feature of AArch64: bits [63:56] are ignored in address
62// translation and can be used to store a tag.
63constexpr unsigned kAddressTagShift = 56;
64constexpr unsigned kTagBits = 8;
65#endif // defined(HWASAN_ALIASING_MODE)
66
67// Mask for extracting tag bits from the lower 8 bits.
68constexpr uptr kTagMask = (1UL << kTagBits) - 1;
69
70// Mask for extracting tag bits from full pointers.
71constexpr uptr kAddressTagMask = kTagMask << kAddressTagShift;
72
73// Minimal alignment of the shadow base address. Determines the space available
74// for threads and stack histories. This is an ABI constant.
75const unsigned kShadowBaseAlignment = 32;
76
77const unsigned kRecordAddrBaseTagShift = 3;
78const unsigned kRecordFPShift = 48;
79const unsigned kRecordFPLShift = 4;
80const unsigned kRecordFPModulus = 1 << (64 - kRecordFPShift + kRecordFPLShift);
81
82static inline bool InTaggableRegion(uptr addr) {
83#if defined(HWASAN_ALIASING_MODE)
84 // Aliases are mapped next to shadow so that the upper bits match the shadow
85 // base.
86 return (addr >> kTaggableRegionCheckShift) ==
87 (__hwasan::GetShadowOffset() >> kTaggableRegionCheckShift);
88#endif
89 return true;
90}
91
92static inline tag_t GetTagFromPointer(uptr p) {
93 return InTaggableRegion(addr: p) ? ((p >> kAddressTagShift) & kTagMask) : 0;
94}
95
96static inline uptr UntagAddr(uptr tagged_addr) {
97 return InTaggableRegion(addr: tagged_addr) ? (tagged_addr & ~kAddressTagMask)
98 : tagged_addr;
99}
100
101static inline void *UntagPtr(const void *tagged_ptr) {
102 return reinterpret_cast<void *>(
103 UntagAddr(tagged_addr: reinterpret_cast<uptr>(tagged_ptr)));
104}
105
106static inline uptr AddTagToPointer(uptr p, tag_t tag) {
107 return InTaggableRegion(addr: p) ? ((p & ~kAddressTagMask) |
108 ((uptr)(tag & kTagMask) << kAddressTagShift))
109 : p;
110}
111
112namespace __hwasan {
113
114extern int hwasan_inited;
115extern bool hwasan_init_is_running;
116extern int hwasan_report_count;
117
118bool InitShadow();
119void InitializeOsSupport();
120void InitThreads();
121void InitializeInterceptors();
122
123void HwasanAllocatorInit();
124void HwasanAllocatorLock();
125void HwasanAllocatorUnlock();
126
127void *hwasan_malloc(uptr size, StackTrace *stack);
128void *hwasan_calloc(uptr nmemb, uptr size, StackTrace *stack);
129void *hwasan_realloc(void *ptr, uptr size, StackTrace *stack);
130void *hwasan_reallocarray(void *ptr, uptr nmemb, uptr size, StackTrace *stack);
131void *hwasan_valloc(uptr size, StackTrace *stack);
132void *hwasan_pvalloc(uptr size, StackTrace *stack);
133void *hwasan_aligned_alloc(uptr alignment, uptr size, StackTrace *stack);
134void *hwasan_memalign(uptr alignment, uptr size, StackTrace *stack);
135int hwasan_posix_memalign(void **memptr, uptr alignment, uptr size,
136 StackTrace *stack);
137void hwasan_free(void *ptr, StackTrace *stack);
138
139void InstallAtExitHandler();
140
141#define GET_MALLOC_STACK_TRACE \
142 BufferedStackTrace stack; \
143 if (hwasan_inited) \
144 stack.Unwind(StackTrace::GetCurrentPc(), GET_CURRENT_FRAME(), \
145 nullptr, common_flags()->fast_unwind_on_malloc, \
146 common_flags()->malloc_context_size)
147
148#define GET_FATAL_STACK_TRACE_PC_BP(pc, bp) \
149 BufferedStackTrace stack; \
150 if (hwasan_inited) \
151 stack.Unwind(pc, bp, nullptr, common_flags()->fast_unwind_on_fatal)
152
153void HwasanTSDInit();
154void HwasanTSDThreadInit();
155void HwasanAtExit();
156
157void HwasanOnDeadlySignal(int signo, void *info, void *context);
158
159void HwasanInstallAtForkHandler();
160
161void InstallAtExitCheckLeaks();
162
163void UpdateMemoryUsage();
164
165void AppendToErrorMessageBuffer(const char *buffer);
166
167void AndroidTestTlsSlot();
168
169// This is a compiler-generated struct that can be shared between hwasan
170// implementations.
171struct AccessInfo {
172 uptr addr;
173 uptr size;
174 bool is_store;
175 bool is_load;
176 bool recover;
177};
178
179// Given access info and frame information, unwind the stack and report the tag
180// mismatch.
181void HandleTagMismatch(AccessInfo ai, uptr pc, uptr frame, void *uc,
182 uptr *registers_frame = nullptr);
183
184// This dispatches to HandleTagMismatch but sets up the AccessInfo, program
185// counter, and frame pointer.
186void HwasanTagMismatch(uptr addr, uptr pc, uptr frame, uptr access_info,
187 uptr *registers_frame, size_t outsize);
188
189} // namespace __hwasan
190
191#if HWASAN_WITH_INTERCEPTORS
192// For both bionic and glibc __sigset_t is an unsigned long.
193typedef unsigned long __hw_sigset_t;
194// Setjmp and longjmp implementations are platform specific, and hence the
195// interception code is platform specific too.
196# if defined(__aarch64__)
197constexpr size_t kHwRegisterBufSize = 22;
198# elif defined(__x86_64__)
199constexpr size_t kHwRegisterBufSize = 8;
200# elif SANITIZER_RISCV64
201// saving PC, 12 int regs, sp, 12 fp regs
202# ifndef __riscv_float_abi_soft
203constexpr size_t kHwRegisterBufSize = 1 + 12 + 1 + 12;
204# else
205constexpr size_t kHwRegisterBufSize = 1 + 12 + 1;
206# endif
207# endif
208typedef unsigned long long __hw_register_buf[kHwRegisterBufSize];
209struct __hw_jmp_buf_struct {
210 // NOTE: The machine-dependent definition of `__sigsetjmp'
211 // assume that a `__hw_jmp_buf' begins with a `__hw_register_buf' and that
212 // `__mask_was_saved' follows it. Do not move these members or add others
213 // before it.
214 //
215 // We add a __magic field to our struct to catch cases where libc's setjmp
216 // populated the jmp_buf instead of our interceptor.
217 __hw_register_buf __jmpbuf; // Calling environment.
218 unsigned __mask_was_saved : 1; // Saved the signal mask?
219 unsigned __magic : 31; // Used to distinguish __hw_jmp_buf from jmp_buf.
220 __hw_sigset_t __saved_mask; // Saved signal mask.
221};
222typedef struct __hw_jmp_buf_struct __hw_jmp_buf[1];
223typedef struct __hw_jmp_buf_struct __hw_sigjmp_buf[1];
224constexpr unsigned kHwJmpBufMagic = 0x248ACE77;
225#endif // HWASAN_WITH_INTERCEPTORS
226
227#define ENSURE_HWASAN_INITED() \
228 do { \
229 CHECK(!hwasan_init_is_running); \
230 if (!hwasan_inited) { \
231 __hwasan_init(); \
232 } \
233 } while (0)
234
235#endif // HWASAN_H
236