1 //===-- asan_debugging.cc -------------------------------------------------===//
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
7 //===----------------------------------------------------------------------===//
9 // This file is a part of AddressSanitizer, an address sanity checker.
11 // This file contains various functions that are generally useful to call when
12 // using a debugger (LLDB, GDB).
13 //===----------------------------------------------------------------------===//
15 #include "asan_allocator.h"
16 #include "asan_descriptions.h"
17 #include "asan_flags.h"
18 #include "asan_internal.h"
19 #include "asan_mapping.h"
20 #include "asan_report.h"
21 #include "asan_thread.h"
24 using namespace __asan;
26 static void FindInfoForStackVar(uptr addr, const char *frame_descr, uptr offset,
27 char *name, uptr name_size,
28 uptr ®ion_address, uptr ®ion_size) {
29 InternalMmapVector<StackVarDescr> vars;
31 if (!ParseFrameDescription(frame_descr, &vars)) {
35 for (uptr i = 0; i < vars.size(); i++) {
36 if (offset <= vars[i].beg + vars[i].size) {
37 // We use name_len + 1 because strlcpy will guarantee a \0 at the end, so
38 // if we're limiting the copy due to name_len, we add 1 to ensure we copy
39 // the whole name and then terminate with '\0'.
40 internal_strlcpy(name, vars[i].name_pos,
41 Min(name_size, vars[i].name_len + 1));
42 region_address = addr - (offset - vars[i].beg);
43 region_size = vars[i].size;
49 uptr AsanGetStack(uptr addr, uptr *trace, u32 size, u32 *thread_id,
51 AsanChunkView chunk = FindHeapChunkByAddress(addr);
52 if (!chunk.IsValid()) return 0;
54 StackTrace stack(nullptr, 0);
56 if (chunk.AllocTid() == kInvalidTid) return 0;
57 stack = chunk.GetAllocStack();
58 if (thread_id) *thread_id = chunk.AllocTid();
60 if (chunk.FreeTid() == kInvalidTid) return 0;
61 stack = chunk.GetFreeStack();
62 if (thread_id) *thread_id = chunk.FreeTid();
66 size = Min(size, Min(stack.size, kStackTraceMax));
67 for (uptr i = 0; i < size; i++)
68 trace[i] = StackTrace::GetPreviousInstructionPc(stack.trace[i]);
78 SANITIZER_INTERFACE_ATTRIBUTE
79 const char *__asan_locate_address(uptr addr, char *name, uptr name_size,
80 uptr *region_address_ptr,
81 uptr *region_size_ptr) {
82 AddressDescription descr(addr);
83 uptr region_address = 0;
85 const char *region_kind = nullptr;
86 if (name && name_size > 0) name[0] = 0;
88 if (auto shadow = descr.AsShadow()) {
89 // region_{address,size} are already 0
90 switch (shadow->kind) {
92 region_kind = "low shadow";
95 region_kind = "shadow gap";
98 region_kind = "high shadow";
101 } else if (auto heap = descr.AsHeap()) {
102 region_kind = "heap";
103 region_address = heap->chunk_access.chunk_begin;
104 region_size = heap->chunk_access.chunk_size;
105 } else if (auto stack = descr.AsStack()) {
106 region_kind = "stack";
107 if (!stack->frame_descr) {
108 // region_{address,size} are already 0
110 FindInfoForStackVar(addr, stack->frame_descr, stack->offset, name,
111 name_size, region_address, region_size);
113 } else if (auto global = descr.AsGlobal()) {
114 region_kind = "global";
115 auto &g = global->globals[0];
116 internal_strlcpy(name, g.name, name_size);
117 region_address = g.beg;
118 region_size = g.size;
120 // region_{address,size} are already 0
121 region_kind = "heap-invalid";
125 if (region_address_ptr) *region_address_ptr = region_address;
126 if (region_size_ptr) *region_size_ptr = region_size;
130 SANITIZER_INTERFACE_ATTRIBUTE
131 uptr __asan_get_alloc_stack(uptr addr, uptr *trace, uptr size, u32 *thread_id) {
132 return AsanGetStack(addr, trace, size, thread_id, /* alloc_stack */ true);
135 SANITIZER_INTERFACE_ATTRIBUTE
136 uptr __asan_get_free_stack(uptr addr, uptr *trace, uptr size, u32 *thread_id) {
137 return AsanGetStack(addr, trace, size, thread_id, /* alloc_stack */ false);
140 SANITIZER_INTERFACE_ATTRIBUTE
141 void __asan_get_shadow_mapping(uptr *shadow_scale, uptr *shadow_offset) {
143 *shadow_scale = SHADOW_SCALE;
145 *shadow_offset = SHADOW_OFFSET;