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