libsanitizer/asan/asan_debugging.cc

   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
  21 namespace __asan {
  22
  23 void 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
  48 void 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
  65 void 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
  82 uptr 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
 111 using namespace __asan;
 112
 113 SANITIZER_INTERFACE_ATTRIBUTE
 114 const 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
 123 SANITIZER_INTERFACE_ATTRIBUTE
 124 uptr __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
 128 SANITIZER_INTERFACE_ATTRIBUTE
 129 uptr __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
 133 SANITIZER_INTERFACE_ATTRIBUTE
 134 void __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 }