1//===-- asan_debugging.cc -------------------------------------------------===//
2//
3// This file is distributed under the University of Illinois Open Source
4// License. See LICENSE.TXT for details.
5//
6//===----------------------------------------------------------------------===//
7//
8// This file is a part of AddressSanitizer, an address sanity checker.
9//
10// This file contains various functions that are generally useful to call when
11// using a debugger (LLDB, GDB).
12//===----------------------------------------------------------------------===//
13
14#include "asan_allocator.h"
15#include "asan_flags.h"
16#include "asan_internal.h"
17#include "asan_mapping.h"
18#include "asan_report.h"
19#include "asan_thread.h"
20
21namespace __asan {
22
23void GetInfoForStackVar(uptr addr, AddressDescription *descr, AsanThread *t) {
24  descr->name[0] = 0;
25  descr->region_address = 0;
26  descr->region_size = 0;
27  descr->region_kind = "stack";
28
29  AsanThread::StackFrameAccess access;
30  if (!t->GetStackFrameAccessByAddr(addr, &access))
31    return;
32  InternalMmapVector<StackVarDescr> vars(16);
33  if (!ParseFrameDescription(access.frame_descr, &vars)) {
34    return;
35  }
36
37  for (uptr i = 0; i < vars.size(); i++) {
38    if (access.offset <= vars[i].beg + vars[i].size) {
39      internal_strncat(descr->name, vars[i].name_pos,
40                       Min(descr->name_size, vars[i].name_len));
41      descr->region_address = addr - (access.offset - vars[i].beg);
42      descr->region_size = vars[i].size;
43      return;
44    }
45  }
46}
47
48void GetInfoForHeapAddress(uptr addr, AddressDescription *descr) {
49  AsanChunkView chunk = FindHeapChunkByAddress(addr);
50
51  descr->name[0] = 0;
52  descr->region_address = 0;
53  descr->region_size = 0;
54
55  if (!chunk.IsValid()) {
56    descr->region_kind = "heap-invalid";
57    return;
58  }
59
60  descr->region_address = chunk.Beg();
61  descr->region_size = chunk.UsedSize();
62  descr->region_kind = "heap";
63}
64
65void AsanLocateAddress(uptr addr, AddressDescription *descr) {
66  if (DescribeAddressIfShadow(addr, descr, /* print */ false)) {
67    return;
68  }
69  if (GetInfoForAddressIfGlobal(addr, descr)) {
70    return;
71  }
72  asanThreadRegistry().Lock();
73  AsanThread *thread = FindThreadByStackAddress(addr);
74  asanThreadRegistry().Unlock();
75  if (thread) {
76    GetInfoForStackVar(addr, descr, thread);
77    return;
78  }
79  GetInfoForHeapAddress(addr, descr);
80}
81
82uptr AsanGetStack(uptr addr, uptr *trace, uptr size, u32 *thread_id,
83                  bool alloc_stack) {
84  AsanChunkView chunk = FindHeapChunkByAddress(addr);
85  if (!chunk.IsValid()) return 0;
86
87  StackTrace stack(nullptr, 0);
88  if (alloc_stack) {
89    if (chunk.AllocTid() == kInvalidTid) return 0;
90    stack = chunk.GetAllocStack();
91    if (thread_id) *thread_id = chunk.AllocTid();
92  } else {
93    if (chunk.FreeTid() == kInvalidTid) return 0;
94    stack = chunk.GetFreeStack();
95    if (thread_id) *thread_id = chunk.FreeTid();
96  }
97
98  if (trace && size) {
99    size = Min(size, Min(stack.size, kStackTraceMax));
100    for (uptr i = 0; i < size; i++)
101      trace[i] = StackTrace::GetPreviousInstructionPc(stack.trace[i]);
102
103    return size;
104  }
105
106  return 0;
107}
108
109}  // namespace __asan
110
111using namespace __asan;
112
113SANITIZER_INTERFACE_ATTRIBUTE
114const char *__asan_locate_address(uptr addr, char *name, uptr name_size,
115                                  uptr *region_address, uptr *region_size) {
116  AddressDescription descr = { name, name_size, 0, 0, 0 };
117  AsanLocateAddress(addr, &descr);
118  if (region_address) *region_address = descr.region_address;
119  if (region_size) *region_size = descr.region_size;
120  return descr.region_kind;
121}
122
123SANITIZER_INTERFACE_ATTRIBUTE
124uptr __asan_get_alloc_stack(uptr addr, uptr *trace, uptr size, u32 *thread_id) {
125  return AsanGetStack(addr, trace, size, thread_id, /* alloc_stack */ true);
126}
127
128SANITIZER_INTERFACE_ATTRIBUTE
129uptr __asan_get_free_stack(uptr addr, uptr *trace, uptr size, u32 *thread_id) {
130  return AsanGetStack(addr, trace, size, thread_id, /* alloc_stack */ false);
131}
132
133SANITIZER_INTERFACE_ATTRIBUTE
134void __asan_get_shadow_mapping(uptr *shadow_scale, uptr *shadow_offset) {
135  if (shadow_scale)
136    *shadow_scale = SHADOW_SCALE;
137  if (shadow_offset)
138    *shadow_offset = SHADOW_OFFSET;
139}
140