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557dbbac8e
Currently, almost all of the shared libraries of MIPS, rely on $t9 to get the address of current function, instead of PCREL instructions, even on MIPSr6. So we have to set $t9 properly. To get the address of preemptible function, we need the help of GOT. MIPS/O32 has .cpload, which can help to generate 3 instructions to get GOT. For __mips64, we can get GOT by: lui $t8, %hi(%neg(%gp_rel(SANITIZER_STRINGIFY(TRAMPOLINE(func))))) daddu $t8, $t8, $t9 daddiu $t8, $t8, %hi(%neg(%gp_rel(SANITIZER_STRINGIFY(TRAMPOLINE(func))))) And then get the address of __interceptor_func, and jump to it ld $t9, %got_disp(_interceptor" SANITIZER_STRINGIFY(func) ")($t8) jr $t9 Upstream-Commit: 0a64367a72f1634321f5051221f05f2f364bd882 libsanitizer * interception/interception.h (substitution_##func_name): Use macro C_ASM_TAIL_CALL. * sanitizer_common/sanitizer_asm.h: Define C_ASM_TAIL_CALL for MIPS with help of t9.
377 lines
17 KiB
C++
377 lines
17 KiB
C++
//===-- interception.h ------------------------------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file is a part of AddressSanitizer, an address sanity checker.
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//
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// Machinery for providing replacements/wrappers for system functions.
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//===----------------------------------------------------------------------===//
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#ifndef INTERCEPTION_H
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#define INTERCEPTION_H
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#include "sanitizer_common/sanitizer_asm.h"
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#include "sanitizer_common/sanitizer_internal_defs.h"
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#if !SANITIZER_LINUX && !SANITIZER_FREEBSD && !SANITIZER_APPLE && \
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!SANITIZER_NETBSD && !SANITIZER_WINDOWS && !SANITIZER_FUCHSIA && \
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!SANITIZER_SOLARIS
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# error "Interception doesn't work on this operating system."
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#endif
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// These typedefs should be used only in the interceptor definitions to replace
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// the standard system types (e.g. SSIZE_T instead of ssize_t)
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typedef __sanitizer::uptr SIZE_T;
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typedef __sanitizer::sptr SSIZE_T;
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typedef __sanitizer::sptr PTRDIFF_T;
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typedef __sanitizer::s64 INTMAX_T;
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typedef __sanitizer::u64 UINTMAX_T;
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typedef __sanitizer::OFF_T OFF_T;
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typedef __sanitizer::OFF64_T OFF64_T;
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// How to add an interceptor:
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// Suppose you need to wrap/replace system function (generally, from libc):
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// int foo(const char *bar, double baz);
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// You'll need to:
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// 1) define INTERCEPTOR(int, foo, const char *bar, double baz) { ... } in
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// your source file. See the notes below for cases when
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// INTERCEPTOR_WITH_SUFFIX(...) should be used instead.
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// 2) Call "INTERCEPT_FUNCTION(foo)" prior to the first call of "foo".
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// INTERCEPT_FUNCTION(foo) evaluates to "true" iff the function was
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// intercepted successfully.
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// You can access original function by calling REAL(foo)(bar, baz).
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// By default, REAL(foo) will be visible only inside your interceptor, and if
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// you want to use it in other parts of RTL, you'll need to:
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// 3a) add DECLARE_REAL(int, foo, const char*, double) to a
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// header file.
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// However, if the call "INTERCEPT_FUNCTION(foo)" and definition for
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// INTERCEPTOR(..., foo, ...) are in different files, you'll instead need to:
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// 3b) add DECLARE_REAL_AND_INTERCEPTOR(int, foo, const char*, double)
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// to a header file.
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// Notes: 1. Things may not work properly if macro INTERCEPTOR(...) {...} or
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// DECLARE_REAL(...) are located inside namespaces.
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// 2. On Mac you can also use: "OVERRIDE_FUNCTION(foo, zoo)" to
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// effectively redirect calls from "foo" to "zoo". In this case
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// you aren't required to implement
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// INTERCEPTOR(int, foo, const char *bar, double baz) {...}
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// but instead you'll have to add
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// DECLARE_REAL(int, foo, const char *bar, double baz) in your
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// source file (to define a pointer to overriden function).
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// 3. Some Mac functions have symbol variants discriminated by
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// additional suffixes, e.g. _$UNIX2003 (see
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// https://developer.apple.com/library/mac/#releasenotes/Darwin/SymbolVariantsRelNotes/index.html
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// for more details). To intercept such functions you need to use the
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// INTERCEPTOR_WITH_SUFFIX(...) macro.
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// How it works on Linux
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// ---------------------
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//
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// To replace system functions on Linux we just need to declare functions with
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// the same names in our library and then obtain the real function pointers
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// using dlsym().
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//
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// There is one complication: a user may also intercept some of the functions we
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// intercept. To allow for up to 3 interceptors (including ours) of a given
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// function "func", the interceptor implementation is in ___interceptor_func,
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// which is aliased by a weak function __interceptor_func, which in turn is
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// aliased (via a trampoline) by weak wrapper function "func".
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//
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// Most user interceptors should define a foreign interceptor as follows:
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//
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// - provide a non-weak function "func" that performs interception;
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// - if __interceptor_func exists, call it to perform the real functionality;
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// - if it does not exist, figure out the real function and call it instead.
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//
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// In rare cases, a foreign interceptor (of another dynamic analysis runtime)
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// may be defined as follows (on supported architectures):
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//
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// - provide a non-weak function __interceptor_func that performs interception;
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// - if ___interceptor_func exists, call it to perform the real functionality;
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// - if it does not exist, figure out the real function and call it instead;
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// - provide a weak function "func" that is an alias to __interceptor_func.
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//
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// With this protocol, sanitizer interceptors, foreign user interceptors, and
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// foreign interceptors of other dynamic analysis runtimes, or any combination
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// thereof, may co-exist simultaneously.
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//
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// How it works on Mac OS
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// ----------------------
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//
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// This is not so on Mac OS, where the two-level namespace makes our replacement
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// functions invisible to other libraries. This may be overcomed using the
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// DYLD_FORCE_FLAT_NAMESPACE, but some errors loading the shared libraries in
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// Chromium were noticed when doing so.
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//
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// Instead we create a dylib containing a __DATA,__interpose section that
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// associates library functions with their wrappers. When this dylib is
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// preloaded before an executable using DYLD_INSERT_LIBRARIES, it routes all the
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// calls to interposed functions done through stubs to the wrapper functions.
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//
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// As it's decided at compile time which functions are to be intercepted on Mac,
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// INTERCEPT_FUNCTION() is effectively a no-op on this system.
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#if SANITIZER_APPLE
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#include <sys/cdefs.h> // For __DARWIN_ALIAS_C().
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// Just a pair of pointers.
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struct interpose_substitution {
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const __sanitizer::uptr replacement;
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const __sanitizer::uptr original;
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};
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// For a function foo() create a global pair of pointers { wrap_foo, foo } in
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// the __DATA,__interpose section.
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// As a result all the calls to foo() will be routed to wrap_foo() at runtime.
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#define INTERPOSER(func_name) __attribute__((used)) \
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const interpose_substitution substitution_##func_name[] \
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__attribute__((section("__DATA, __interpose"))) = { \
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{ reinterpret_cast<const uptr>(WRAP(func_name)), \
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reinterpret_cast<const uptr>(func_name) } \
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}
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// For a function foo() and a wrapper function bar() create a global pair
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// of pointers { bar, foo } in the __DATA,__interpose section.
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// As a result all the calls to foo() will be routed to bar() at runtime.
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#define INTERPOSER_2(func_name, wrapper_name) __attribute__((used)) \
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const interpose_substitution substitution_##func_name[] \
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__attribute__((section("__DATA, __interpose"))) = { \
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{ reinterpret_cast<const uptr>(wrapper_name), \
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reinterpret_cast<const uptr>(func_name) } \
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}
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# define WRAP(x) wrap_##x
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# define TRAMPOLINE(x) WRAP(x)
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# define INTERCEPTOR_ATTRIBUTE
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# define DECLARE_WRAPPER(ret_type, func, ...)
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#elif SANITIZER_WINDOWS
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# define WRAP(x) __asan_wrap_##x
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# define TRAMPOLINE(x) WRAP(x)
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# define INTERCEPTOR_ATTRIBUTE __declspec(dllexport)
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# define DECLARE_WRAPPER(ret_type, func, ...) \
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extern "C" ret_type func(__VA_ARGS__);
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# define DECLARE_WRAPPER_WINAPI(ret_type, func, ...) \
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extern "C" __declspec(dllimport) ret_type __stdcall func(__VA_ARGS__);
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#elif !SANITIZER_FUCHSIA // LINUX, FREEBSD, NETBSD, SOLARIS
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# define INTERCEPTOR_ATTRIBUTE __attribute__((visibility("default")))
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# if ASM_INTERCEPTOR_TRAMPOLINE_SUPPORT
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// Weak aliases of weak aliases do not work, therefore we need to set up a
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// trampoline function. The function "func" is a weak alias to the trampoline
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// (so that we may check if "func" was overridden), which calls the weak
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// function __interceptor_func, which in turn aliases the actual interceptor
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// implementation ___interceptor_func:
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//
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// [wrapper "func": weak] --(alias)--> [TRAMPOLINE(func)]
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// |
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// +--------(tail call)-------+
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// |
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// v
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// [__interceptor_func: weak] --(alias)--> [WRAP(func)]
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//
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// We use inline assembly to define most of this, because not all compilers
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// support functions with the "naked" attribute with every architecture.
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# define WRAP(x) ___interceptor_ ## x
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# define TRAMPOLINE(x) __interceptor_trampoline_ ## x
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# if SANITIZER_FREEBSD || SANITIZER_NETBSD
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// FreeBSD's dynamic linker (incompliantly) gives non-weak symbols higher
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// priority than weak ones so weak aliases won't work for indirect calls
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// in position-independent (-fPIC / -fPIE) mode.
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# define __ASM_WEAK_WRAPPER(func) ".globl " #func "\n"
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# else
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# define __ASM_WEAK_WRAPPER(func) ".weak " #func "\n"
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# endif // SANITIZER_FREEBSD || SANITIZER_NETBSD
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# if defined(__arm__) || defined(__aarch64__)
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# define ASM_TYPE_FUNCTION_STR "%function"
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# else
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# define ASM_TYPE_FUNCTION_STR "@function"
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# endif
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// Keep trampoline implementation in sync with sanitizer_common/sanitizer_asm.h
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# define DECLARE_WRAPPER(ret_type, func, ...) \
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extern "C" ret_type func(__VA_ARGS__); \
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extern "C" ret_type TRAMPOLINE(func)(__VA_ARGS__); \
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extern "C" ret_type __interceptor_##func(__VA_ARGS__) \
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INTERCEPTOR_ATTRIBUTE __attribute__((weak)) ALIAS(WRAP(func)); \
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asm( \
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".text\n" \
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__ASM_WEAK_WRAPPER(func) \
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".set " #func ", " SANITIZER_STRINGIFY(TRAMPOLINE(func)) "\n" \
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".globl " SANITIZER_STRINGIFY(TRAMPOLINE(func)) "\n" \
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".type " SANITIZER_STRINGIFY(TRAMPOLINE(func)) ", " \
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ASM_TYPE_FUNCTION_STR "\n" \
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SANITIZER_STRINGIFY(TRAMPOLINE(func)) ":\n" \
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SANITIZER_STRINGIFY(CFI_STARTPROC) "\n" \
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C_ASM_TAIL_CALL(SANITIZER_STRINGIFY(TRAMPOLINE(func)), \
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"__interceptor_" \
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SANITIZER_STRINGIFY(ASM_PREEMPTIBLE_SYM(func))) "\n" \
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SANITIZER_STRINGIFY(CFI_ENDPROC) "\n" \
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".size " SANITIZER_STRINGIFY(TRAMPOLINE(func)) ", " \
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".-" SANITIZER_STRINGIFY(TRAMPOLINE(func)) "\n" \
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);
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# else // ASM_INTERCEPTOR_TRAMPOLINE_SUPPORT
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// Some architectures cannot implement efficient interceptor trampolines with
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// just a plain jump due to complexities of resolving a preemptible symbol. In
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// those cases, revert to just this scheme:
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//
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// [wrapper "func": weak] --(alias)--> [WRAP(func)]
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//
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# define WRAP(x) __interceptor_ ## x
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# define TRAMPOLINE(x) WRAP(x)
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# if SANITIZER_FREEBSD || SANITIZER_NETBSD
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# define __ATTRIBUTE_WEAK_WRAPPER
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# else
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# define __ATTRIBUTE_WEAK_WRAPPER __attribute__((weak))
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# endif // SANITIZER_FREEBSD || SANITIZER_NETBSD
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# define DECLARE_WRAPPER(ret_type, func, ...) \
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extern "C" ret_type func(__VA_ARGS__) \
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INTERCEPTOR_ATTRIBUTE __ATTRIBUTE_WEAK_WRAPPER ALIAS(WRAP(func));
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# endif // ASM_INTERCEPTOR_TRAMPOLINE_SUPPORT
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#endif
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#if SANITIZER_FUCHSIA
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// There is no general interception at all on Fuchsia.
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// Sanitizer runtimes just define functions directly to preempt them,
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// and have bespoke ways to access the underlying libc functions.
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# include <zircon/sanitizer.h>
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# define INTERCEPTOR_ATTRIBUTE __attribute__((visibility("default")))
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# define REAL(x) __unsanitized_##x
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# define DECLARE_REAL(ret_type, func, ...)
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#elif !SANITIZER_APPLE
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# define PTR_TO_REAL(x) real_##x
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# define REAL(x) __interception::PTR_TO_REAL(x)
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# define FUNC_TYPE(x) x##_type
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# define DECLARE_REAL(ret_type, func, ...) \
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typedef ret_type (*FUNC_TYPE(func))(__VA_ARGS__); \
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namespace __interception { \
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extern FUNC_TYPE(func) PTR_TO_REAL(func); \
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}
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# define ASSIGN_REAL(dst, src) REAL(dst) = REAL(src)
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#else // SANITIZER_APPLE
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# define REAL(x) x
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# define DECLARE_REAL(ret_type, func, ...) \
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extern "C" ret_type func(__VA_ARGS__);
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# define ASSIGN_REAL(x, y)
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#endif // SANITIZER_APPLE
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#if !SANITIZER_FUCHSIA
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# define DECLARE_REAL_AND_INTERCEPTOR(ret_type, func, ...) \
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DECLARE_REAL(ret_type, func, __VA_ARGS__) \
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extern "C" ret_type TRAMPOLINE(func)(__VA_ARGS__); \
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extern "C" ret_type WRAP(func)(__VA_ARGS__);
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// Declare an interceptor and its wrapper defined in a different translation
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// unit (ex. asm).
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# define DECLARE_EXTERN_INTERCEPTOR_AND_WRAPPER(ret_type, func, ...) \
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extern "C" ret_type TRAMPOLINE(func)(__VA_ARGS__); \
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extern "C" ret_type WRAP(func)(__VA_ARGS__); \
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extern "C" ret_type func(__VA_ARGS__);
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#else
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# define DECLARE_REAL_AND_INTERCEPTOR(ret_type, func, ...)
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# define DECLARE_EXTERN_INTERCEPTOR_AND_WRAPPER(ret_type, func, ...)
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#endif
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// Generally, you don't need to use DEFINE_REAL by itself, as INTERCEPTOR
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// macros does its job. In exceptional cases you may need to call REAL(foo)
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// without defining INTERCEPTOR(..., foo, ...). For example, if you override
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// foo with an interceptor for other function.
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#if !SANITIZER_APPLE && !SANITIZER_FUCHSIA
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# define DEFINE_REAL(ret_type, func, ...) \
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typedef ret_type (*FUNC_TYPE(func))(__VA_ARGS__); \
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namespace __interception { \
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FUNC_TYPE(func) PTR_TO_REAL(func); \
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}
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#else
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# define DEFINE_REAL(ret_type, func, ...)
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#endif
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#if SANITIZER_FUCHSIA
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// We need to define the __interceptor_func name just to get
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// sanitizer_common/scripts/gen_dynamic_list.py to export func.
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// But we don't need to export __interceptor_func to get that.
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#define INTERCEPTOR(ret_type, func, ...) \
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extern "C"[[ gnu::alias(#func), gnu::visibility("hidden") ]] ret_type \
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__interceptor_##func(__VA_ARGS__); \
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extern "C" INTERCEPTOR_ATTRIBUTE ret_type func(__VA_ARGS__)
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#elif !SANITIZER_APPLE
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#define INTERCEPTOR(ret_type, func, ...) \
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DEFINE_REAL(ret_type, func, __VA_ARGS__) \
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DECLARE_WRAPPER(ret_type, func, __VA_ARGS__) \
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extern "C" INTERCEPTOR_ATTRIBUTE ret_type WRAP(func)(__VA_ARGS__)
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// We don't need INTERCEPTOR_WITH_SUFFIX on non-Darwin for now.
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#define INTERCEPTOR_WITH_SUFFIX(ret_type, func, ...) \
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INTERCEPTOR(ret_type, func, __VA_ARGS__)
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#else // SANITIZER_APPLE
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#define INTERCEPTOR_ZZZ(suffix, ret_type, func, ...) \
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extern "C" ret_type func(__VA_ARGS__) suffix; \
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extern "C" ret_type WRAP(func)(__VA_ARGS__); \
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INTERPOSER(func); \
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extern "C" INTERCEPTOR_ATTRIBUTE ret_type WRAP(func)(__VA_ARGS__)
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#define INTERCEPTOR(ret_type, func, ...) \
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INTERCEPTOR_ZZZ(/*no symbol variants*/, ret_type, func, __VA_ARGS__)
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#define INTERCEPTOR_WITH_SUFFIX(ret_type, func, ...) \
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INTERCEPTOR_ZZZ(__DARWIN_ALIAS_C(func), ret_type, func, __VA_ARGS__)
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// Override |overridee| with |overrider|.
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#define OVERRIDE_FUNCTION(overridee, overrider) \
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INTERPOSER_2(overridee, WRAP(overrider))
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#endif
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#if SANITIZER_WINDOWS
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# define INTERCEPTOR_WINAPI(ret_type, func, ...) \
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typedef ret_type (__stdcall *FUNC_TYPE(func))(__VA_ARGS__); \
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namespace __interception { \
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FUNC_TYPE(func) PTR_TO_REAL(func); \
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} \
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extern "C" INTERCEPTOR_ATTRIBUTE ret_type __stdcall WRAP(func)(__VA_ARGS__)
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#endif
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// ISO C++ forbids casting between pointer-to-function and pointer-to-object,
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// so we use casting via an integral type __interception::uptr,
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// assuming that system is POSIX-compliant. Using other hacks seem
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// challenging, as we don't even pass function type to
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// INTERCEPT_FUNCTION macro, only its name.
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namespace __interception {
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#if defined(_WIN64)
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typedef unsigned long long uptr;
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#else
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typedef unsigned long uptr;
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#endif // _WIN64
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} // namespace __interception
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#define INCLUDED_FROM_INTERCEPTION_LIB
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#if SANITIZER_LINUX || SANITIZER_FREEBSD || SANITIZER_NETBSD || \
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SANITIZER_SOLARIS
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# include "interception_linux.h"
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# define INTERCEPT_FUNCTION(func) INTERCEPT_FUNCTION_LINUX_OR_FREEBSD(func)
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# define INTERCEPT_FUNCTION_VER(func, symver) \
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INTERCEPT_FUNCTION_VER_LINUX_OR_FREEBSD(func, symver)
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#elif SANITIZER_APPLE
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# include "interception_mac.h"
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# define INTERCEPT_FUNCTION(func) INTERCEPT_FUNCTION_MAC(func)
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# define INTERCEPT_FUNCTION_VER(func, symver) \
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INTERCEPT_FUNCTION_VER_MAC(func, symver)
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#elif SANITIZER_WINDOWS
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# include "interception_win.h"
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# define INTERCEPT_FUNCTION(func) INTERCEPT_FUNCTION_WIN(func)
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# define INTERCEPT_FUNCTION_VER(func, symver) \
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INTERCEPT_FUNCTION_VER_WIN(func, symver)
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#endif
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#undef INCLUDED_FROM_INTERCEPTION_LIB
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#endif // INTERCEPTION_H
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