base/debug/profiler.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/debug/profiler.h"
   6
   7 #include <string>
   8
   9 #include "base/process/process_handle.h"
  10 #include "base/strings/string_util.h"
  11 #include "base/strings/stringprintf.h"
  12
  13 #if defined(OS_WIN)
  14 #include "base/win/pe_image.h"
  15 #endif  // defined(OS_WIN)
  16
  17 // TODO(peria): Enable profiling on Windows.
  18 #if defined(ENABLE_PROFILING) && !defined(NO_TCMALLOC) && !defined(OS_WIN)
  19 #include "third_party/tcmalloc/chromium/src/gperftools/profiler.h"
  20 #endif
  21
  22 namespace base {
  23 namespace debug {
  24
  25 // TODO(peria): Enable profiling on Windows.
  26 #if defined(ENABLE_PROFILING) && !defined(NO_TCMALLOC) && !defined(OS_WIN)
  27
  28 static int profile_count = 0;
  29
  30 void StartProfiling(const std::string& name) {
  31   ++profile_count;
  32   std::string full_name(name);
  33   std::string pid = StringPrintf("%d", GetCurrentProcId());
  34   std::string count = StringPrintf("%d", profile_count);
  35   ReplaceSubstringsAfterOffset(&full_name, 0, "{pid}", pid);
  36   ReplaceSubstringsAfterOffset(&full_name, 0, "{count}", count);
  37   ProfilerStart(full_name.c_str());
  38 }
  39
  40 void StopProfiling() {
  41   ProfilerFlush();
  42   ProfilerStop();
  43 }
  44
  45 void FlushProfiling() {
  46   ProfilerFlush();
  47 }
  48
  49 bool BeingProfiled() {
  50   return ProfilingIsEnabledForAllThreads();
  51 }
  52
  53 void RestartProfilingAfterFork() {
  54   ProfilerRegisterThread();
  55 }
  56
  57 #else
  58
  59 void StartProfiling(const std::string& name) {
  60 }
  61
  62 void StopProfiling() {
  63 }
  64
  65 void FlushProfiling() {
  66 }
  67
  68 bool BeingProfiled() {
  69   return false;
  70 }
  71
  72 void RestartProfilingAfterFork() {
  73 }
  74
  75 #endif
  76
  77 #if !defined(OS_WIN)
  78
  79 bool IsBinaryInstrumented() {
  80   return false;
  81 }
  82
  83 ReturnAddressLocationResolver GetProfilerReturnAddrResolutionFunc() {
  84   return NULL;
  85 }
  86
  87 DynamicFunctionEntryHook GetProfilerDynamicFunctionEntryHookFunc() {
  88   return NULL;
  89 }
  90
  91 AddDynamicSymbol GetProfilerAddDynamicSymbolFunc() {
  92   return NULL;
  93 }
  94
  95 MoveDynamicSymbol GetProfilerMoveDynamicSymbolFunc() {
  96   return NULL;
  97 }
  98
  99 #else  // defined(OS_WIN)
 100
 101 // http://blogs.msdn.com/oldnewthing/archive/2004/10/25/247180.aspx
 102 extern "C" IMAGE_DOS_HEADER __ImageBase;
 103
 104 bool IsBinaryInstrumented() {
 105   enum InstrumentationCheckState {
 106     UNINITIALIZED,
 107     INSTRUMENTED_IMAGE,
 108     NON_INSTRUMENTED_IMAGE,
 109   };
 110
 111   static InstrumentationCheckState state = UNINITIALIZED;
 112
 113   if (state == UNINITIALIZED) {
 114     HMODULE this_module = reinterpret_cast<HMODULE>(&__ImageBase);
 115     base::win::PEImage image(this_module);
 116
 117     // Check to be sure our image is structured as we'd expect.
 118     DCHECK(image.VerifyMagic());
 119
 120     // Syzygy-instrumented binaries contain a PE image section named ".thunks",
 121     // and all Syzygy-modified binaries contain the ".syzygy" image section.
 122     // This is a very fast check, as it only looks at the image header.
 123     if ((image.GetImageSectionHeaderByName(".thunks") != NULL) &&
 124         (image.GetImageSectionHeaderByName(".syzygy") != NULL)) {
 125       state = INSTRUMENTED_IMAGE;
 126     } else {
 127       state = NON_INSTRUMENTED_IMAGE;
 128     }
 129   }
 130   DCHECK(state != UNINITIALIZED);
 131
 132   return state == INSTRUMENTED_IMAGE;
 133 }
 134
 135 namespace {
 136
 137 struct FunctionSearchContext {
 138   const char* name;
 139   FARPROC function;
 140 };
 141
 142 // Callback function to PEImage::EnumImportChunks.
 143 bool FindResolutionFunctionInImports(
 144     const base::win::PEImage &image, const char* module_name,
 145     PIMAGE_THUNK_DATA unused_name_table, PIMAGE_THUNK_DATA import_address_table,
 146     PVOID cookie) {
 147   FunctionSearchContext* context =
 148       reinterpret_cast<FunctionSearchContext*>(cookie);
 149
 150   DCHECK_NE(static_cast<FunctionSearchContext*>(NULL), context);
 151   DCHECK_EQ(static_cast<FARPROC>(NULL), context->function);
 152
 153   // Our import address table contains pointers to the functions we import
 154   // at this point. Let's retrieve the first such function and use it to
 155   // find the module this import was resolved to by the loader.
 156   const wchar_t* function_in_module =
 157       reinterpret_cast<const wchar_t*>(import_address_table->u1.Function);
 158
 159   // Retrieve the module by a function in the module.
 160   const DWORD kFlags = GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS |
 161                        GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT;
 162   HMODULE module = NULL;
 163   if (!::GetModuleHandleEx(kFlags, function_in_module, &module)) {
 164     // This can happen if someone IAT patches us to a thunk.
 165     return true;
 166   }
 167
 168   // See whether this module exports the function we're looking for.
 169   FARPROC exported_func = ::GetProcAddress(module, context->name);
 170   if (exported_func != NULL) {
 171     // We found it, return the function and terminate the enumeration.
 172     context->function = exported_func;
 173     return false;
 174   }
 175
 176   // Keep going.
 177   return true;
 178 }
 179
 180 template <typename FunctionType>
 181 FunctionType FindFunctionInImports(const char* function_name) {
 182   if (!IsBinaryInstrumented())
 183     return NULL;
 184
 185   HMODULE this_module = reinterpret_cast<HMODULE>(&__ImageBase);
 186   base::win::PEImage image(this_module);
 187
 188   FunctionSearchContext ctx = { function_name, NULL };
 189   image.EnumImportChunks(FindResolutionFunctionInImports, &ctx);
 190
 191   return reinterpret_cast<FunctionType>(ctx.function);
 192 }
 193
 194 }  // namespace
 195
 196 ReturnAddressLocationResolver GetProfilerReturnAddrResolutionFunc() {
 197   return FindFunctionInImports<ReturnAddressLocationResolver>(
 198       "ResolveReturnAddressLocation");
 199 }
 200
 201 DynamicFunctionEntryHook GetProfilerDynamicFunctionEntryHookFunc() {
 202   return FindFunctionInImports<DynamicFunctionEntryHook>(
 203       "OnDynamicFunctionEntry");
 204 }
 205
 206 AddDynamicSymbol GetProfilerAddDynamicSymbolFunc() {
 207   return FindFunctionInImports<AddDynamicSymbol>(
 208       "AddDynamicSymbol");
 209 }
 210
 211 MoveDynamicSymbol GetProfilerMoveDynamicSymbolFunc() {
 212   return FindFunctionInImports<MoveDynamicSymbol>(
 213       "MoveDynamicSymbol");
 214 }
 215
 216 #endif  // defined(OS_WIN)
 217
 218 }  // namespace debug
 219 }  // namespace base