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Diffstat (limited to 'security/sandbox/chromium/base/debug/profiler.h')
-rw-r--r-- | security/sandbox/chromium/base/debug/profiler.h | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/security/sandbox/chromium/base/debug/profiler.h b/security/sandbox/chromium/base/debug/profiler.h new file mode 100644 index 000000000..7cce7b08f --- /dev/null +++ b/security/sandbox/chromium/base/debug/profiler.h @@ -0,0 +1,91 @@ +// Copyright (c) 2012 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#ifndef BASE_DEBUG_PROFILER_H_ +#define BASE_DEBUG_PROFILER_H_ + +#include <stddef.h> + +#include <string> + +#include "base/base_export.h" + +// The Profiler functions allow usage of the underlying sampling based +// profiler. If the application has not been built with the necessary +// flags (-DENABLE_PROFILING and not -DNO_TCMALLOC) then these functions +// are noops. +namespace base { +namespace debug { + +// Start profiling with the supplied name. +// {pid} will be replaced by the process' pid and {count} will be replaced +// by the count of the profile run (starts at 1 with each process). +BASE_EXPORT void StartProfiling(const std::string& name); + +// Stop profiling and write out data. +BASE_EXPORT void StopProfiling(); + +// Force data to be written to file. +BASE_EXPORT void FlushProfiling(); + +// Returns true if process is being profiled. +BASE_EXPORT bool BeingProfiled(); + +// Reset profiling after a fork, which disables timers. +BASE_EXPORT void RestartProfilingAfterFork(); + +// Returns true iff this executable is instrumented with the Syzygy profiler. +BASE_EXPORT bool IsBinaryInstrumented(); + +// There's a class of profilers that use "return address swizzling" to get a +// hook on function exits. This class of profilers uses some form of entry hook, +// like e.g. binary instrumentation, or a compiler flag, that calls a hook each +// time a function is invoked. The hook then switches the return address on the +// stack for the address of an exit hook function, and pushes the original +// return address to a shadow stack of some type. When in due course the CPU +// executes a return to the exit hook, the exit hook will do whatever work it +// does on function exit, then arrange to return to the original return address. +// This class of profiler does not play well with programs that look at the +// return address, as does e.g. V8. V8 uses the return address to certain +// runtime functions to find the JIT code that called it, and from there finds +// the V8 data structures associated to the JS function involved. +// A return address resolution function is used to fix this. It allows such +// programs to resolve a location on stack where a return address originally +// resided, to the shadow stack location where the profiler stashed it. +typedef uintptr_t (*ReturnAddressLocationResolver)( + uintptr_t return_addr_location); + +// This type declaration must match V8's FunctionEntryHook. +typedef void (*DynamicFunctionEntryHook)(uintptr_t function, + uintptr_t return_addr_location); + +// The functions below here are to support profiling V8-generated code. +// V8 has provisions for generating a call to an entry hook for newly generated +// JIT code, and it can push symbol information on code generation and advise +// when the garbage collector moves code. The functions declarations below here +// make glue between V8's facilities and a profiler. + +// This type declaration must match V8's FunctionEntryHook. +typedef void (*DynamicFunctionEntryHook)(uintptr_t function, + uintptr_t return_addr_location); + +typedef void (*AddDynamicSymbol)(const void* address, + size_t length, + const char* name, + size_t name_len); +typedef void (*MoveDynamicSymbol)(const void* address, const void* new_address); + + +// If this binary is instrumented and the instrumentation supplies a function +// for each of those purposes, find and return the function in question. +// Otherwise returns NULL. +BASE_EXPORT ReturnAddressLocationResolver GetProfilerReturnAddrResolutionFunc(); +BASE_EXPORT DynamicFunctionEntryHook GetProfilerDynamicFunctionEntryHookFunc(); +BASE_EXPORT AddDynamicSymbol GetProfilerAddDynamicSymbolFunc(); +BASE_EXPORT MoveDynamicSymbol GetProfilerMoveDynamicSymbolFunc(); + +} // namespace debug +} // namespace base + +#endif // BASE_DEBUG_PROFILER_H_ |