1//===-- sanitizer_wrappers.cpp ----------------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Redirect some functions to sanitizer interceptors.
10//
11//===----------------------------------------------------------------------===//
12
13#include <dlfcn.h>
14#include <errno.h>
15#include <fcntl.h>
16#include <inttypes.h>
17#include <stdarg.h>
18#include <stdio.h>
19#include <unistd.h>
20
21#include <tuple>
22
23namespace __sanitizer {
24unsigned long internal_open(const char *filename, int flags);
25unsigned long internal_open(const char *filename, int flags, unsigned mode);
26unsigned long internal_close(int fd);
27unsigned long internal_stat(const char *path, void *buf);
28unsigned long internal_lstat(const char *path, void *buf);
29unsigned long internal_fstat(int fd, void *buf);
30size_t internal_strlen(const char *s);
31unsigned long internal_mmap(void *addr, uintptr_t length, int prot, int flags,
32                            int fd, unsigned long long offset);
33void *internal_memcpy(void *dest, const void *src, unsigned long n);
34// Used to propagate errno.
35bool internal_iserror(uintptr_t retval, int *rverrno = 0);
36}  // namespace __sanitizer
37
38namespace {
39
40template <typename T>
41struct GetTypes;
42
43template <typename R, typename... Args>
44struct GetTypes<R(Args...)> {
45  using Result = R;
46  template <size_t i>
47  struct Arg {
48    using Type = typename std::tuple_element<i, std::tuple<Args...>>::type;
49  };
50};
51
52#define LLVM_SYMBOLIZER_GET_FUNC(Function) \
53  ((__interceptor_##Function)              \
54       ? (__interceptor_##Function)        \
55       : reinterpret_cast<decltype(&Function)>(dlsym(RTLD_NEXT, #Function)))
56
57#define LLVM_SYMBOLIZER_INTERCEPTOR1(Function, ...)               \
58  GetTypes<__VA_ARGS__>::Result __interceptor_##Function(         \
59      GetTypes<__VA_ARGS__>::Arg<0>::Type) __attribute__((weak)); \
60  GetTypes<__VA_ARGS__>::Result Function(                         \
61      GetTypes<__VA_ARGS__>::Arg<0>::Type arg0) {                 \
62    return LLVM_SYMBOLIZER_GET_FUNC(Function)(arg0);              \
63  }
64
65#define LLVM_SYMBOLIZER_INTERCEPTOR2(Function, ...)               \
66  GetTypes<__VA_ARGS__>::Result __interceptor_##Function(         \
67      GetTypes<__VA_ARGS__>::Arg<0>::Type,                        \
68      GetTypes<__VA_ARGS__>::Arg<1>::Type) __attribute__((weak)); \
69  GetTypes<__VA_ARGS__>::Result Function(                         \
70      GetTypes<__VA_ARGS__>::Arg<0>::Type arg0,                   \
71      GetTypes<__VA_ARGS__>::Arg<1>::Type arg1) {                 \
72    return LLVM_SYMBOLIZER_GET_FUNC(Function)(arg0, arg1);        \
73  }
74
75#define LLVM_SYMBOLIZER_INTERCEPTOR3(Function, ...)               \
76  GetTypes<__VA_ARGS__>::Result __interceptor_##Function(         \
77      GetTypes<__VA_ARGS__>::Arg<0>::Type,                        \
78      GetTypes<__VA_ARGS__>::Arg<1>::Type,                        \
79      GetTypes<__VA_ARGS__>::Arg<2>::Type) __attribute__((weak)); \
80  GetTypes<__VA_ARGS__>::Result Function(                         \
81      GetTypes<__VA_ARGS__>::Arg<0>::Type arg0,                   \
82      GetTypes<__VA_ARGS__>::Arg<1>::Type arg1,                   \
83      GetTypes<__VA_ARGS__>::Arg<2>::Type arg2) {                 \
84    return LLVM_SYMBOLIZER_GET_FUNC(Function)(arg0, arg1, arg2);  \
85  }
86
87#define LLVM_SYMBOLIZER_INTERCEPTOR4(Function, ...)                    \
88  GetTypes<__VA_ARGS__>::Result __interceptor_##Function(              \
89      GetTypes<__VA_ARGS__>::Arg<0>::Type,                             \
90      GetTypes<__VA_ARGS__>::Arg<1>::Type,                             \
91      GetTypes<__VA_ARGS__>::Arg<2>::Type,                             \
92      GetTypes<__VA_ARGS__>::Arg<3>::Type) __attribute__((weak));      \
93  GetTypes<__VA_ARGS__>::Result Function(                              \
94      GetTypes<__VA_ARGS__>::Arg<0>::Type arg0,                        \
95      GetTypes<__VA_ARGS__>::Arg<1>::Type arg1,                        \
96      GetTypes<__VA_ARGS__>::Arg<2>::Type arg2,                        \
97      GetTypes<__VA_ARGS__>::Arg<3>::Type arg3) {                      \
98    return LLVM_SYMBOLIZER_GET_FUNC(Function)(arg0, arg1, arg2, arg3); \
99  }
100
101}  // namespace
102
103// C-style interface around internal sanitizer libc functions.
104extern "C" {
105
106#define RETURN_OR_SET_ERRNO(T, res)                   \
107  int rverrno;                                        \
108  if (__sanitizer::internal_iserror(res, &rverrno)) { \
109    errno = rverrno;                                  \
110    return (T)-1;                                     \
111  }                                                   \
112  return (T)res;
113
114int open(const char *filename, int flags, ...) {
115  unsigned long res;
116  if (flags | O_CREAT) {
117    va_list va;
118    va_start(va, flags);
119    unsigned mode = va_arg(va, unsigned);
120    va_end(va);
121    res = __sanitizer::internal_open(filename, flags, mode);
122  } else {
123    res = __sanitizer::internal_open(filename, flags);
124  }
125  RETURN_OR_SET_ERRNO(int, res);
126}
127
128int close(int fd) {
129  unsigned long res = __sanitizer::internal_close(fd);
130  RETURN_OR_SET_ERRNO(int, res);
131}
132
133#define STAT(func, arg, buf)                                  \
134  unsigned long res = __sanitizer::internal_##func(arg, buf); \
135  RETURN_OR_SET_ERRNO(int, res);
136
137int stat(const char *path, struct stat *buf) { STAT(stat, path, buf); }
138
139int lstat(const char *path, struct stat *buf) { STAT(lstat, path, buf); }
140
141int fstat(int fd, struct stat *buf) { STAT(fstat, fd, buf); }
142
143// Redirect versioned stat functions to the __sanitizer::internal() as well.
144int __xstat(int version, const char *path, struct stat *buf) {
145  STAT(stat, path, buf);
146}
147
148int __lxstat(int version, const char *path, struct stat *buf) {
149  STAT(lstat, path, buf);
150}
151
152int __fxstat(int version, int fd, struct stat *buf) { STAT(fstat, fd, buf); }
153
154size_t strlen(const char *s) { return __sanitizer::internal_strlen(s); }
155
156void *mmap(void *addr, size_t length, int prot, int flags, int fd,
157           off_t offset) {
158  unsigned long res =
159      __sanitizer::internal_mmap(addr, length, prot, flags, fd, offset);
160  RETURN_OR_SET_ERRNO(void *, res);
161}
162
163LLVM_SYMBOLIZER_INTERCEPTOR3(read, ssize_t(int, void *, size_t))
164LLVM_SYMBOLIZER_INTERCEPTOR4(pread, ssize_t(int, void *, size_t, off_t))
165LLVM_SYMBOLIZER_INTERCEPTOR4(pread64, ssize_t(int, void *, size_t, off64_t))
166LLVM_SYMBOLIZER_INTERCEPTOR2(realpath, char *(const char *, char *))
167
168LLVM_SYMBOLIZER_INTERCEPTOR1(pthread_cond_broadcast, int(pthread_cond_t *))
169LLVM_SYMBOLIZER_INTERCEPTOR2(pthread_cond_wait,
170                             int(pthread_cond_t *, pthread_mutex_t *))
171LLVM_SYMBOLIZER_INTERCEPTOR1(pthread_mutex_lock, int(pthread_mutex_t *))
172LLVM_SYMBOLIZER_INTERCEPTOR1(pthread_mutex_unlock, int(pthread_mutex_t *))
173LLVM_SYMBOLIZER_INTERCEPTOR1(pthread_mutex_destroy, int(pthread_mutex_t *))
174LLVM_SYMBOLIZER_INTERCEPTOR2(pthread_mutex_init,
175                             int(pthread_mutex_t *,
176                                 const pthread_mutexattr_t *))
177LLVM_SYMBOLIZER_INTERCEPTOR1(pthread_mutexattr_destroy,
178                             int(pthread_mutexattr_t *))
179LLVM_SYMBOLIZER_INTERCEPTOR1(pthread_mutexattr_init, int(pthread_mutexattr_t *))
180LLVM_SYMBOLIZER_INTERCEPTOR2(pthread_mutexattr_settype,
181                             int(pthread_mutexattr_t *, int))
182LLVM_SYMBOLIZER_INTERCEPTOR1(pthread_getspecific, void *(pthread_key_t))
183LLVM_SYMBOLIZER_INTERCEPTOR2(pthread_key_create,
184                             int(pthread_key_t *, void (*)(void *)))
185LLVM_SYMBOLIZER_INTERCEPTOR2(pthread_once,
186                             int(pthread_once_t *, void (*)(void)))
187LLVM_SYMBOLIZER_INTERCEPTOR2(pthread_setspecific,
188                             int(pthread_key_t, const void *))
189LLVM_SYMBOLIZER_INTERCEPTOR3(pthread_sigmask,
190                             int(int, const sigset_t *, sigset_t *))
191
192}  // extern "C"
193