xref: /aosp_15_r20/bionic/libc/private/bionic_ifuncs.h (revision 8d67ca893c1523eb926b9080dbe4e2ffd2a27ba1)
1 /*
2  * Copyright (C) 2019 The Android Open Source Project
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *  * Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  *  * Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in
12  *    the documentation and/or other materials provided with the
13  *    distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #pragma once
30 
31 #include <stdint.h>
32 #include <sys/ifunc.h>
33 
34 #include <private/bionic_call_ifunc_resolver.h>
35 
36 #if defined(__aarch64__)
37 #define IFUNC_ARGS (uint64_t hwcap __attribute__((unused)), \
38                     __ifunc_arg_t* arg __attribute__((unused)))
39 #elif defined(__arm__)
40 #define IFUNC_ARGS (unsigned long hwcap __attribute__((unused)))
41 #else
42 #define IFUNC_ARGS ()
43 #endif
44 
45 #define DECLARE_FUNC(type, name) \
46     __attribute__((visibility("hidden"))) \
47     type name
48 
49 #define RETURN_FUNC(type, name) { \
50         DECLARE_FUNC(type, name); \
51         return name; \
52     }
53 
54 #if defined(BIONIC_DYNAMIC_DISPATCH)
55 
56 // We can't have HWASAN enabled in resolvers because they may be called before
57 // HWASAN is initialized.
58 #define DEFINE_IFUNC_FOR(name)                                  \
59   name##_func_t name __attribute__((ifunc(#name "_resolver"))); \
60   __attribute__((visibility("hidden")))                         \
61   __attribute__((no_sanitize("hwaddress"))) name##_func_t* name##_resolver IFUNC_ARGS
62 
63 #define DEFINE_STATIC_SHIM(x)
64 
65 #elif defined(BIONIC_STATIC_DISPATCH)
66 
67 #define DEFINE_IFUNC_FOR(name)               \
68   name##_func_t* name##_resolver IFUNC_ARGS; \
69   __attribute__((visibility("hidden")))      \
70   __attribute__((no_sanitize("hwaddress"))) name##_func_t* name##_resolver IFUNC_ARGS
71 
72 #define DEFINE_STATIC_SHIM(x) x
73 
74 #define FORWARD(name)                                                               \
75   static name##_func_t* fn = reinterpret_cast<name##_func_t*>(                      \
76       __bionic_call_ifunc_resolver(reinterpret_cast<ElfW(Addr)>(name##_resolver))); \
77   return fn
78 
79 #else
80 #error neither dynamic nor static dispatch?!
81 #endif
82 
83 typedef void* memchr_func_t(const void*, int, size_t);
84 #define MEMCHR_SHIM()                                                  \
85   DEFINE_STATIC_SHIM(void* memchr(const void* src, int ch, size_t n) { \
86     FORWARD(memchr)(src, ch, n);                                       \
87   })
88 
89 typedef int memcmp_func_t(const void*, const void*, size_t);
90 #define MEMCMP_SHIM()                                                         \
91   DEFINE_STATIC_SHIM(int memcmp(const void* lhs, const void* rhs, size_t n) { \
92     FORWARD(memcmp)(lhs, rhs, n);                                             \
93   })
94 
95 typedef void* memcpy_func_t(void*, const void*, size_t);
96 #define MEMCPY_SHIM()                                                     \
97   DEFINE_STATIC_SHIM(void* memcpy(void* dst, const void* src, size_t n) { \
98     FORWARD(memcpy)(dst, src, n);                                         \
99   })
100 
101 typedef void* memmove_func_t(void*, const void*, size_t);
102 #define MEMMOVE_SHIM()                                                     \
103   DEFINE_STATIC_SHIM(void* memmove(void* dst, const void* src, size_t n) { \
104     FORWARD(memmove)(dst, src, n);                                         \
105   })
106 
107 typedef int memrchr_func_t(const void*, int, size_t);
108 #define MEMRCHR_SHIM()                                                \
109   DEFINE_STATIC_SHIM(int memrchr(const void* src, int ch, size_t n) { \
110     FORWARD(memrchr)(src, ch, n);                                     \
111   })
112 
113 typedef void* memset_func_t(void*, int, size_t);
114 #define MEMSET_SHIM() \
115   DEFINE_STATIC_SHIM(void* memset(void* dst, int ch, size_t n) { FORWARD(memset)(dst, ch, n); })
116 
117 typedef void* __memset_chk_func_t(void*, int, size_t, size_t);
118 #define __MEMSET_CHK_SHIM()                                                       \
119   DEFINE_STATIC_SHIM(void* __memset_chk(void* dst, int ch, size_t n, size_t n2) { \
120     FORWARD(__memset_chk)(dst, ch, n, n2);                                        \
121   })
122 
123 typedef char* stpcpy_func_t(char*, const char*);
124 #define STPCPY_SHIM() \
125   DEFINE_STATIC_SHIM(char* stpcpy(char* dst, const char* src) { FORWARD(stpcpy)(dst, src); })
126 
127 typedef char* strcat_func_t(char*, const char*);
128 #define STRCAT_SHIM() \
129   DEFINE_STATIC_SHIM(char* strcat(char* dst, const char* src) { FORWARD(strcat)(dst, src); })
130 
131 typedef char* __strcat_chk_func_t(char*, const char*, size_t);
132 #define __STRCAT_CHK_SHIM()                                                                \
133   DEFINE_STATIC_SHIM(char* __strcat_chk(char* dst, const char* src, size_t dst_buf_size) { \
134     FORWARD(__strcat_chk)(dst, src, dst_buf_size);                                         \
135   })
136 
137 typedef char* strchr_func_t(const char*, int);
138 #define STRCHR_SHIM() \
139   DEFINE_STATIC_SHIM(char* strchr(const char* src, int ch) { FORWARD(strchr)(src, ch); })
140 
141 typedef char* strchrnul_func_t(const char*, int);
142 #define STRCHRNUL_SHIM() \
143   DEFINE_STATIC_SHIM(char* strchrnul(const char* src, int ch) { FORWARD(strchrnul)(src, ch); })
144 
145 typedef int strcmp_func_t(const char*, const char*);
146 #define STRCMP_SHIM() \
147   DEFINE_STATIC_SHIM(int strcmp(char* lhs, const char* rhs) { FORWARD(strcmp)(lhs, rhs); })
148 
149 typedef char* strcpy_func_t(char*, const char*);
150 #define STRCPY_SHIM() \
151   DEFINE_STATIC_SHIM(char* strcpy(char* dst, const char* src) { FORWARD(strcpy)(dst, src); })
152 
153 typedef char* __strcpy_chk_func_t(char*, const char*, size_t);
154 #define __STRCPY_CHK_SHIM()                                                           \
155   DEFINE_STATIC_SHIM(char* __strcpy_chk(char* dst, const char* src, size_t dst_len) { \
156     FORWARD(__strcpy_chk)(dst, src, dst_len);                                         \
157   })
158 
159 typedef size_t strlen_func_t(const char*);
160 #define STRLEN_SHIM() DEFINE_STATIC_SHIM(size_t strlen(const char* s) { FORWARD(strlen)(s); })
161 
162 typedef char* strncat_func_t(char*, const char*, size_t);
163 #define STRNCAT_SHIM()                                                     \
164   DEFINE_STATIC_SHIM(char* strncat(char* dst, const char* src, size_t n) { \
165     FORWARD(strncat)(dst, src, n);                                         \
166   })
167 
168 typedef int strncmp_func_t(const char*, const char*, size_t);
169 #define STRNCMP_SHIM()                                                         \
170   DEFINE_STATIC_SHIM(int strncmp(const char* lhs, const char* rhs, size_t n) { \
171     FORWARD(strncmp)(lhs, rhs, n);                                             \
172   })
173 
174 typedef char* strncpy_func_t(char*, const char*, size_t);
175 #define STRNCPY_SHIM()                                                     \
176   DEFINE_STATIC_SHIM(char* strncpy(char* dst, const char* src, size_t n) { \
177     FORWARD(strncpy)(dst, src, n);                                         \
178   })
179 
180 typedef size_t strnlen_func_t(const char*, size_t);
181 #define STRNLEN_SHIM() \
182   DEFINE_STATIC_SHIM(size_t strnlen(const char* s, size_t n) { FORWARD(strnlen)(s, n); })
183 
184 typedef char* strrchr_func_t(const char*, int);
185 #define STRRCHR_SHIM() \
186   DEFINE_STATIC_SHIM(char* strrchr(const char* src, int ch) { FORWARD(strrchr)(src, ch); })
187