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Diffstat (limited to 'gcc-4.9/libsanitizer/interception/interception.h')
| -rw-r--r-- | gcc-4.9/libsanitizer/interception/interception.h | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/gcc-4.9/libsanitizer/interception/interception.h b/gcc-4.9/libsanitizer/interception/interception.h new file mode 100644 index 000000000..7393f4c26 --- /dev/null +++ b/gcc-4.9/libsanitizer/interception/interception.h @@ -0,0 +1,255 @@ +//===-- interception.h ------------------------------------------*- C++ -*-===// +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file is a part of AddressSanitizer, an address sanity checker. +// +// Machinery for providing replacements/wrappers for system functions. +//===----------------------------------------------------------------------===// + +#ifndef INTERCEPTION_H +#define INTERCEPTION_H + +#if !defined(__linux__) && !defined(__APPLE__) && !defined(_WIN32) +# error "Interception doesn't work on this operating system." +#endif + +#include "sanitizer_common/sanitizer_internal_defs.h" + +// These typedefs should be used only in the interceptor definitions to replace +// the standard system types (e.g. SSIZE_T instead of ssize_t) +typedef __sanitizer::uptr SIZE_T; +typedef __sanitizer::sptr SSIZE_T; +typedef __sanitizer::sptr PTRDIFF_T; +typedef __sanitizer::s64 INTMAX_T; +typedef __sanitizer::OFF_T OFF_T; +typedef __sanitizer::OFF64_T OFF64_T; + +// How to add an interceptor: +// Suppose you need to wrap/replace system function (generally, from libc): +// int foo(const char *bar, double baz); +// You'll need to: +// 1) define INTERCEPTOR(int, foo, const char *bar, double baz) { ... } in +// your source file. See the notes below for cases when +// INTERCEPTOR_WITH_SUFFIX(...) should be used instead. +// 2) Call "INTERCEPT_FUNCTION(foo)" prior to the first call of "foo". +// INTERCEPT_FUNCTION(foo) evaluates to "true" iff the function was +// intercepted successfully. +// You can access original function by calling REAL(foo)(bar, baz). +// By default, REAL(foo) will be visible only inside your interceptor, and if +// you want to use it in other parts of RTL, you'll need to: +// 3a) add DECLARE_REAL(int, foo, const char*, double) to a +// header file. +// However, if the call "INTERCEPT_FUNCTION(foo)" and definition for +// INTERCEPTOR(..., foo, ...) are in different files, you'll instead need to: +// 3b) add DECLARE_REAL_AND_INTERCEPTOR(int, foo, const char*, double) +// to a header file. + +// Notes: 1. Things may not work properly if macro INTERCEPTOR(...) {...} or +// DECLARE_REAL(...) are located inside namespaces. +// 2. On Mac you can also use: "OVERRIDE_FUNCTION(foo, zoo)" to +// effectively redirect calls from "foo" to "zoo". In this case +// you aren't required to implement +// INTERCEPTOR(int, foo, const char *bar, double baz) {...} +// but instead you'll have to add +// DECLARE_REAL(int, foo, const char *bar, double baz) in your +// source file (to define a pointer to overriden function). +// 3. Some Mac functions have symbol variants discriminated by +// additional suffixes, e.g. _$UNIX2003 (see +// https://developer.apple.com/library/mac/#releasenotes/Darwin/SymbolVariantsRelNotes/index.html +// for more details). To intercept such functions you need to use the +// INTERCEPTOR_WITH_SUFFIX(...) macro. + +// How it works: +// To replace system functions on Linux we just need to declare functions +// with same names in our library and then obtain the real function pointers +// using dlsym(). +// There is one complication. A user may also intercept some of the functions +// we intercept. To resolve this we declare our interceptors with __interceptor_ +// prefix, and then make actual interceptors weak aliases to __interceptor_ +// functions. +// +// This is not so on Mac OS, where the two-level namespace makes +// our replacement functions invisible to other libraries. This may be overcomed +// using the DYLD_FORCE_FLAT_NAMESPACE, but some errors loading the shared +// libraries in Chromium were noticed when doing so. +// Instead we create a dylib containing a __DATA,__interpose section that +// associates library functions with their wrappers. When this dylib is +// preloaded before an executable using DYLD_INSERT_LIBRARIES, it routes all +// the calls to interposed functions done through stubs to the wrapper +// functions. +// As it's decided at compile time which functions are to be intercepted on Mac, +// INTERCEPT_FUNCTION() is effectively a no-op on this system. + +#if defined(__APPLE__) +#include <sys/cdefs.h> // For __DARWIN_ALIAS_C(). + +// Just a pair of pointers. +struct interpose_substitution { + const uptr replacement; + const uptr original; +}; + +// For a function foo() create a global pair of pointers { wrap_foo, foo } in +// the __DATA,__interpose section. +// As a result all the calls to foo() will be routed to wrap_foo() at runtime. +#define INTERPOSER(func_name) __attribute__((used)) \ +const interpose_substitution substitution_##func_name[] \ + __attribute__((section("__DATA, __interpose"))) = { \ + { reinterpret_cast<const uptr>(WRAP(func_name)), \ + reinterpret_cast<const uptr>(func_name) } \ +} + +// For a function foo() and a wrapper function bar() create a global pair +// of pointers { bar, foo } in the __DATA,__interpose section. +// As a result all the calls to foo() will be routed to bar() at runtime. +#define INTERPOSER_2(func_name, wrapper_name) __attribute__((used)) \ +const interpose_substitution substitution_##func_name[] \ + __attribute__((section("__DATA, __interpose"))) = { \ + { reinterpret_cast<const uptr>(wrapper_name), \ + reinterpret_cast<const uptr>(func_name) } \ +} + +# define WRAP(x) wrap_##x +# define WRAPPER_NAME(x) "wrap_"#x +# define INTERCEPTOR_ATTRIBUTE +# define DECLARE_WRAPPER(ret_type, func, ...) + +#elif defined(_WIN32) +# if defined(_DLL) // DLL CRT +# define WRAP(x) x +# define WRAPPER_NAME(x) #x +# define INTERCEPTOR_ATTRIBUTE +# else // Static CRT +# define WRAP(x) wrap_##x +# define WRAPPER_NAME(x) "wrap_"#x +# define INTERCEPTOR_ATTRIBUTE +# endif +# define DECLARE_WRAPPER(ret_type, func, ...) \ + extern "C" ret_type func(__VA_ARGS__); +# define DECLARE_WRAPPER_WINAPI(ret_type, func, ...) \ + extern "C" __declspec(dllimport) ret_type __stdcall func(__VA_ARGS__); +#else +# define WRAP(x) __interceptor_ ## x +# define WRAPPER_NAME(x) "__interceptor_" #x +# define INTERCEPTOR_ATTRIBUTE __attribute__((visibility("default"))) +# define DECLARE_WRAPPER(ret_type, func, ...) \ + extern "C" ret_type func(__VA_ARGS__) \ + __attribute__((weak, alias("__interceptor_" #func), visibility("default"))); +#endif + +#if !defined(__APPLE__) +# define PTR_TO_REAL(x) real_##x +# define REAL(x) __interception::PTR_TO_REAL(x) +# define FUNC_TYPE(x) x##_f + +# define DECLARE_REAL(ret_type, func, ...) \ + typedef ret_type (*FUNC_TYPE(func))(__VA_ARGS__); \ + namespace __interception { \ + extern FUNC_TYPE(func) PTR_TO_REAL(func); \ + } +#else // __APPLE__ +# define REAL(x) x +# define DECLARE_REAL(ret_type, func, ...) \ + extern "C" ret_type func(__VA_ARGS__); +#endif // __APPLE__ + +#define DECLARE_REAL_AND_INTERCEPTOR(ret_type, func, ...) \ + DECLARE_REAL(ret_type, func, __VA_ARGS__) \ + extern "C" ret_type WRAP(func)(__VA_ARGS__); + +// Generally, you don't need to use DEFINE_REAL by itself, as INTERCEPTOR +// macros does its job. In exceptional cases you may need to call REAL(foo) +// without defining INTERCEPTOR(..., foo, ...). For example, if you override +// foo with an interceptor for other function. +#if !defined(__APPLE__) +# define DEFINE_REAL(ret_type, func, ...) \ + typedef ret_type (*FUNC_TYPE(func))(__VA_ARGS__); \ + namespace __interception { \ + FUNC_TYPE(func) PTR_TO_REAL(func); \ + } +#else +# define DEFINE_REAL(ret_type, func, ...) +#endif + +#if !defined(__APPLE__) +#define INTERCEPTOR(ret_type, func, ...) \ + DEFINE_REAL(ret_type, func, __VA_ARGS__) \ + DECLARE_WRAPPER(ret_type, func, __VA_ARGS__) \ + extern "C" \ + INTERCEPTOR_ATTRIBUTE \ + ret_type WRAP(func)(__VA_ARGS__) + +// We don't need INTERCEPTOR_WITH_SUFFIX on non-Darwin for now. +#define INTERCEPTOR_WITH_SUFFIX(ret_type, func, ...) \ + INTERCEPTOR(ret_type, func, __VA_ARGS__) + +#else // __APPLE__ + +#define INTERCEPTOR_ZZZ(suffix, ret_type, func, ...) \ + extern "C" ret_type func(__VA_ARGS__) suffix; \ + extern "C" ret_type WRAP(func)(__VA_ARGS__); \ + INTERPOSER(func); \ + extern "C" INTERCEPTOR_ATTRIBUTE ret_type WRAP(func)(__VA_ARGS__) + +#define INTERCEPTOR(ret_type, func, ...) \ + INTERCEPTOR_ZZZ(/*no symbol variants*/, ret_type, func, __VA_ARGS__) + +#define INTERCEPTOR_WITH_SUFFIX(ret_type, func, ...) \ + INTERCEPTOR_ZZZ(__DARWIN_ALIAS_C(func), ret_type, func, __VA_ARGS__) + +// Override |overridee| with |overrider|. +#define OVERRIDE_FUNCTION(overridee, overrider) \ + INTERPOSER_2(overridee, WRAP(overrider)) +#endif + +#if defined(_WIN32) +# define INTERCEPTOR_WINAPI(ret_type, func, ...) \ + typedef ret_type (__stdcall *FUNC_TYPE(func))(__VA_ARGS__); \ + namespace __interception { \ + FUNC_TYPE(func) PTR_TO_REAL(func); \ + } \ + DECLARE_WRAPPER_WINAPI(ret_type, func, __VA_ARGS__) \ + extern "C" \ + INTERCEPTOR_ATTRIBUTE \ + ret_type __stdcall WRAP(func)(__VA_ARGS__) +#endif + +// ISO C++ forbids casting between pointer-to-function and pointer-to-object, +// so we use casting via an integral type __interception::uptr, +// assuming that system is POSIX-compliant. Using other hacks seem +// challenging, as we don't even pass function type to +// INTERCEPT_FUNCTION macro, only its name. +namespace __interception { +#if defined(_WIN64) +typedef unsigned long long uptr; // NOLINT +#else +typedef unsigned long uptr; // NOLINT +#endif // _WIN64 +} // namespace __interception + +#define INCLUDED_FROM_INTERCEPTION_LIB + +#if defined(__linux__) +# include "interception_linux.h" +# define INTERCEPT_FUNCTION(func) INTERCEPT_FUNCTION_LINUX(func) +# define INTERCEPT_FUNCTION_VER(func, symver) \ + INTERCEPT_FUNCTION_VER_LINUX(func, symver) +#elif defined(__APPLE__) +# include "interception_mac.h" +# define INTERCEPT_FUNCTION(func) INTERCEPT_FUNCTION_MAC(func) +# define INTERCEPT_FUNCTION_VER(func, symver) \ + INTERCEPT_FUNCTION_VER_MAC(func, symver) +#else // defined(_WIN32) +# include "interception_win.h" +# define INTERCEPT_FUNCTION(func) INTERCEPT_FUNCTION_WIN(func) +# define INTERCEPT_FUNCTION_VER(func, symver) \ + INTERCEPT_FUNCTION_VER_WIN(func, symver) +#endif + +#undef INCLUDED_FROM_INTERCEPTION_LIB + +#endif // INTERCEPTION_H |