148 lines · cpp
1//===-- asan_debugging.cpp ------------------------------------------------===//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-exception6//7//===----------------------------------------------------------------------===//8//9// This file is a part of AddressSanitizer, an address sanity checker.10//11// This file contains various functions that are generally useful to call when12// using a debugger (LLDB, GDB).13//===----------------------------------------------------------------------===//14 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"22#include "sanitizer_common/sanitizer_stackdepot.h"23 24namespace {25using namespace __asan;26 27static void FindInfoForStackVar(uptr addr, const char *frame_descr, uptr offset,28 char *name, uptr name_size,29 uptr *region_address, uptr *region_size) {30 InternalMmapVector<StackVarDescr> vars;31 vars.reserve(16);32 if (!ParseFrameDescription(frame_descr, &vars)) {33 return;34 }35 36 for (uptr i = 0; i < vars.size(); i++) {37 if (offset <= vars[i].beg + vars[i].size) {38 // We use name_len + 1 because strlcpy will guarantee a \0 at the end, so39 // if we're limiting the copy due to name_len, we add 1 to ensure we copy40 // the whole name and then terminate with '\0'.41 internal_strlcpy(name, vars[i].name_pos,42 Min(name_size, vars[i].name_len + 1));43 *region_address = addr - (offset - vars[i].beg);44 *region_size = vars[i].size;45 return;46 }47 }48}49 50uptr AsanGetStack(uptr addr, uptr *trace, u32 size, u32 *thread_id,51 bool alloc_stack) {52 AsanChunkView chunk = FindHeapChunkByAddress(addr);53 if (!chunk.IsValid()) return 0;54 55 StackTrace stack(nullptr, 0);56 if (alloc_stack) {57 if (chunk.AllocTid() == kInvalidTid) return 0;58 stack = StackDepotGet(chunk.GetAllocStackId());59 if (thread_id) *thread_id = chunk.AllocTid();60 } else {61 if (chunk.FreeTid() == kInvalidTid) return 0;62 stack = StackDepotGet(chunk.GetFreeStackId());63 if (thread_id) *thread_id = chunk.FreeTid();64 }65 66 if (trace && size) {67 size = Min(size, Min(stack.size, kStackTraceMax));68 for (uptr i = 0; i < size; i++)69 trace[i] = StackTrace::GetPreviousInstructionPc(stack.trace[i]);70 71 return size;72 }73 74 return 0;75}76 77} // namespace78 79SANITIZER_INTERFACE_ATTRIBUTE80const char *__asan_locate_address(uptr addr, char *name, uptr name_size,81 uptr *region_address_ptr,82 uptr *region_size_ptr) {83 AddressDescription descr(addr);84 uptr region_address = 0;85 uptr region_size = 0;86 const char *region_kind = nullptr;87 if (name && name_size > 0) name[0] = 0;88 89 if (auto shadow = descr.AsShadow()) {90 // region_{address,size} are already 091 switch (shadow->kind) {92 case kShadowKindLow:93 region_kind = "low shadow";94 break;95 case kShadowKindGap:96 region_kind = "shadow gap";97 break;98 case kShadowKindHigh:99 region_kind = "high shadow";100 break;101 }102 } else if (auto heap = descr.AsHeap()) {103 region_kind = "heap";104 region_address = heap->chunk_access.chunk_begin;105 region_size = heap->chunk_access.chunk_size;106 } else if (auto stack = descr.AsStack()) {107 region_kind = "stack";108 if (!stack->frame_descr) {109 // region_{address,size} are already 0110 } else {111 FindInfoForStackVar(addr, stack->frame_descr, stack->offset, name,112 name_size, ®ion_address, ®ion_size);113 }114 } else if (auto global = descr.AsGlobal()) {115 region_kind = "global";116 auto &g = global->globals[0];117 internal_strlcpy(name, g.name, name_size);118 region_address = g.beg;119 region_size = g.size;120 } else {121 // region_{address,size} are already 0122 region_kind = "heap-invalid";123 }124 125 CHECK(region_kind);126 if (region_address_ptr) *region_address_ptr = region_address;127 if (region_size_ptr) *region_size_ptr = region_size;128 return region_kind;129}130 131SANITIZER_INTERFACE_ATTRIBUTE132uptr __asan_get_alloc_stack(uptr addr, uptr *trace, uptr size, u32 *thread_id) {133 return AsanGetStack(addr, trace, size, thread_id, /* alloc_stack */ true);134}135 136SANITIZER_INTERFACE_ATTRIBUTE137uptr __asan_get_free_stack(uptr addr, uptr *trace, uptr size, u32 *thread_id) {138 return AsanGetStack(addr, trace, size, thread_id, /* alloc_stack */ false);139}140 141SANITIZER_INTERFACE_ATTRIBUTE142void __asan_get_shadow_mapping(uptr *shadow_scale, uptr *shadow_offset) {143 if (shadow_scale)144 *shadow_scale = ASAN_SHADOW_SCALE;145 if (shadow_offset)146 *shadow_offset = ASAN_SHADOW_OFFSET;147}148