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Diffstat (limited to 'gcc-4.8/libsanitizer/interception/interception.h')
| -rw-r--r-- | gcc-4.8/libsanitizer/interception/interception.h | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/gcc-4.8/libsanitizer/interception/interception.h b/gcc-4.8/libsanitizer/interception/interception.h new file mode 100644 index 000000000..c4c5026c7 --- /dev/null +++ b/gcc-4.8/libsanitizer/interception/interception.h @@ -0,0 +1,194 @@ +//===-- 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; +// WARNING: OFF_T may be different from OS type off_t, depending on the value of +// _FILE_OFFSET_BITS. This definition of OFF_T matches the ABI of system calls +// like pread and mmap, as opposed to pread64 and mmap64. +// Mac and Linux/x86-64 are special. +#if defined(__APPLE__) || (defined(__linux__) && defined(__x86_64__)) +typedef __sanitizer::u64 OFF_T; +#else +typedef __sanitizer::uptr OFF_T; +#endif +typedef __sanitizer::u64 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. +// 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 INTERCEPT(...) {...} 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 +// DEFINE_REAL(int, foo, const char *bar, double baz) in your +// source file (to define a pointer to overriden function). + +// 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. + +#if defined(__APPLE__) +# 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, ...) +#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 + +#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__) + +#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(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) +#elif defined(__APPLE__) +# include "interception_mac.h" +# define OVERRIDE_FUNCTION(old_func, new_func) \ + OVERRIDE_FUNCTION_MAC(old_func, new_func) +# define INTERCEPT_FUNCTION(func) INTERCEPT_FUNCTION_MAC(func) +#else // defined(_WIN32) +# include "interception_win.h" +# define INTERCEPT_FUNCTION(func) INTERCEPT_FUNCTION_WIN(func) +#endif + +#undef INCLUDED_FROM_INTERCEPTION_LIB + +#endif // INTERCEPTION_H |