michael@0: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: #include "base/debug/profiler.h"
michael@0: 
michael@0: #include <string>
michael@0: 
michael@0: #include "base/process/process_handle.h"
michael@0: #include "base/strings/string_util.h"
michael@0: #include "base/strings/stringprintf.h"
michael@0: 
michael@0: #if defined(OS_WIN)
michael@0: #include "base/win/pe_image.h"
michael@0: #endif  // defined(OS_WIN)
michael@0: 
michael@0: #if defined(ENABLE_PROFILING) && !defined(NO_TCMALLOC)
michael@0: #include "third_party/tcmalloc/chromium/src/gperftools/profiler.h"
michael@0: #endif
michael@0: 
michael@0: namespace base {
michael@0: namespace debug {
michael@0: 
michael@0: #if defined(ENABLE_PROFILING) && !defined(NO_TCMALLOC)
michael@0: 
michael@0: static int profile_count = 0;
michael@0: 
michael@0: void StartProfiling(const std::string& name) {
michael@0:   ++profile_count;
michael@0:   std::string full_name(name);
michael@0:   std::string pid = StringPrintf("%d", GetCurrentProcId());
michael@0:   std::string count = StringPrintf("%d", profile_count);
michael@0:   ReplaceSubstringsAfterOffset(&full_name, 0, "{pid}", pid);
michael@0:   ReplaceSubstringsAfterOffset(&full_name, 0, "{count}", count);
michael@0:   ProfilerStart(full_name.c_str());
michael@0: }
michael@0: 
michael@0: void StopProfiling() {
michael@0:   ProfilerFlush();
michael@0:   ProfilerStop();
michael@0: }
michael@0: 
michael@0: void FlushProfiling() {
michael@0:   ProfilerFlush();
michael@0: }
michael@0: 
michael@0: bool BeingProfiled() {
michael@0:   return ProfilingIsEnabledForAllThreads();
michael@0: }
michael@0: 
michael@0: void RestartProfilingAfterFork() {
michael@0:   ProfilerRegisterThread();
michael@0: }
michael@0: 
michael@0: #else
michael@0: 
michael@0: void StartProfiling(const std::string& name) {
michael@0: }
michael@0: 
michael@0: void StopProfiling() {
michael@0: }
michael@0: 
michael@0: void FlushProfiling() {
michael@0: }
michael@0: 
michael@0: bool BeingProfiled() {
michael@0:   return false;
michael@0: }
michael@0: 
michael@0: void RestartProfilingAfterFork() {
michael@0: }
michael@0: 
michael@0: #endif
michael@0: 
michael@0: #if !defined(OS_WIN)
michael@0: 
michael@0: bool IsBinaryInstrumented() {
michael@0:   return false;
michael@0: }
michael@0: 
michael@0: ReturnAddressLocationResolver GetProfilerReturnAddrResolutionFunc() {
michael@0:   return NULL;
michael@0: }
michael@0: 
michael@0: DynamicFunctionEntryHook GetProfilerDynamicFunctionEntryHookFunc() {
michael@0:   return NULL;
michael@0: }
michael@0: 
michael@0: AddDynamicSymbol GetProfilerAddDynamicSymbolFunc() {
michael@0:   return NULL;
michael@0: }
michael@0: 
michael@0: MoveDynamicSymbol GetProfilerMoveDynamicSymbolFunc() {
michael@0:   return NULL;
michael@0: }
michael@0: 
michael@0: #else  // defined(OS_WIN)
michael@0: 
michael@0: // http://blogs.msdn.com/oldnewthing/archive/2004/10/25/247180.aspx
michael@0: extern "C" IMAGE_DOS_HEADER __ImageBase;
michael@0: 
michael@0: bool IsBinaryInstrumented() {
michael@0:   enum InstrumentationCheckState {
michael@0:     UNINITIALIZED,
michael@0:     INSTRUMENTED_IMAGE,
michael@0:     NON_INSTRUMENTED_IMAGE,
michael@0:   };
michael@0: 
michael@0:   static InstrumentationCheckState state = UNINITIALIZED;
michael@0: 
michael@0:   if (state == UNINITIALIZED) {
michael@0:     HMODULE this_module = reinterpret_cast<HMODULE>(&__ImageBase);
michael@0:     base::win::PEImage image(this_module);
michael@0: 
michael@0:     // Check to be sure our image is structured as we'd expect.
michael@0:     DCHECK(image.VerifyMagic());
michael@0: 
michael@0:     // Syzygy-instrumented binaries contain a PE image section named ".thunks",
michael@0:     // and all Syzygy-modified binaries contain the ".syzygy" image section.
michael@0:     // This is a very fast check, as it only looks at the image header.
michael@0:     if ((image.GetImageSectionHeaderByName(".thunks") != NULL) &&
michael@0:         (image.GetImageSectionHeaderByName(".syzygy") != NULL)) {
michael@0:       state = INSTRUMENTED_IMAGE;
michael@0:     } else {
michael@0:       state = NON_INSTRUMENTED_IMAGE;
michael@0:     }
michael@0:   }
michael@0:   DCHECK(state != UNINITIALIZED);
michael@0: 
michael@0:   return state == INSTRUMENTED_IMAGE;
michael@0: }
michael@0: 
michael@0: namespace {
michael@0: 
michael@0: struct FunctionSearchContext {
michael@0:   const char* name;
michael@0:   FARPROC function;
michael@0: };
michael@0: 
michael@0: // Callback function to PEImage::EnumImportChunks.
michael@0: bool FindResolutionFunctionInImports(
michael@0:     const base::win::PEImage &image, const char* module_name,
michael@0:     PIMAGE_THUNK_DATA unused_name_table, PIMAGE_THUNK_DATA import_address_table,
michael@0:     PVOID cookie) {
michael@0:   FunctionSearchContext* context =
michael@0:       reinterpret_cast<FunctionSearchContext*>(cookie);
michael@0: 
michael@0:   DCHECK_NE(static_cast<FunctionSearchContext*>(NULL), context);
michael@0:   DCHECK_EQ(static_cast<FARPROC>(NULL), context->function);
michael@0: 
michael@0:   // Our import address table contains pointers to the functions we import
michael@0:   // at this point. Let's retrieve the first such function and use it to
michael@0:   // find the module this import was resolved to by the loader.
michael@0:   const wchar_t* function_in_module =
michael@0:       reinterpret_cast<const wchar_t*>(import_address_table->u1.Function);
michael@0: 
michael@0:   // Retrieve the module by a function in the module.
michael@0:   const DWORD kFlags = GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS |
michael@0:                        GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT;
michael@0:   HMODULE module = NULL;
michael@0:   if (!::GetModuleHandleEx(kFlags, function_in_module, &module)) {
michael@0:     // This can happen if someone IAT patches us to a thunk.
michael@0:     return true;
michael@0:   }
michael@0: 
michael@0:   // See whether this module exports the function we're looking for.
michael@0:   FARPROC exported_func = ::GetProcAddress(module, context->name);
michael@0:   if (exported_func != NULL) {
michael@0:     // We found it, return the function and terminate the enumeration.
michael@0:     context->function = exported_func;
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   // Keep going.
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: template <typename FunctionType>
michael@0: FunctionType FindFunctionInImports(const char* function_name) {
michael@0:   if (!IsBinaryInstrumented())
michael@0:     return NULL;
michael@0: 
michael@0:   HMODULE this_module = reinterpret_cast<HMODULE>(&__ImageBase);
michael@0:   base::win::PEImage image(this_module);
michael@0: 
michael@0:   FunctionSearchContext ctx = { function_name, NULL };
michael@0:   image.EnumImportChunks(FindResolutionFunctionInImports, &ctx);
michael@0: 
michael@0:   return reinterpret_cast<FunctionType>(ctx.function);
michael@0: }
michael@0: 
michael@0: }  // namespace
michael@0: 
michael@0: ReturnAddressLocationResolver GetProfilerReturnAddrResolutionFunc() {
michael@0:   return FindFunctionInImports<ReturnAddressLocationResolver>(
michael@0:       "ResolveReturnAddressLocation");
michael@0: }
michael@0: 
michael@0: DynamicFunctionEntryHook GetProfilerDynamicFunctionEntryHookFunc() {
michael@0:   return FindFunctionInImports<DynamicFunctionEntryHook>(
michael@0:       "OnDynamicFunctionEntry");
michael@0: }
michael@0: 
michael@0: AddDynamicSymbol GetProfilerAddDynamicSymbolFunc() {
michael@0:   return FindFunctionInImports<AddDynamicSymbol>(
michael@0:       "AddDynamicSymbol");
michael@0: }
michael@0: 
michael@0: MoveDynamicSymbol GetProfilerMoveDynamicSymbolFunc() {
michael@0:   return FindFunctionInImports<MoveDynamicSymbol>(
michael@0:       "MoveDynamicSymbol");
michael@0: }
michael@0: 
michael@0: #endif  // defined(OS_WIN)
michael@0: 
michael@0: }  // namespace debug
michael@0: }  // namespace base