1 /*
2 * Copyright (C) 2023 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 #include <fcntl.h>
30 #include <private/bionic_ifuncs.h>
31 #include <stddef.h>
32 #include <sys/syscall.h>
33 #include <unistd.h>
34
35 extern "C" {
36
ifunc_faccessat(int dir_fd,const char * path,int mode)37 static inline __always_inline int ifunc_faccessat(int dir_fd, const char* path, int mode) {
38 register long a0 __asm__("a0") = dir_fd;
39 register long a1 __asm__("a1") = reinterpret_cast<long>(path);
40 register long a2 __asm__("a2") = mode;
41 register long a7 __asm__("a7") = __NR_faccessat;
42 __asm__("ecall" : "=r"(a0) : "r"(a0), "r"(a1), "r"(a2), "r"(a7) : "memory");
43 return a0;
44 }
45
have_fast_v()46 static bool have_fast_v() {
47 static bool result = []() {
48 // We don't want to do a full "bogomips" test, so just check for the
49 // presence of a file that would indicate that we're running in qemu.
50 return ifunc_faccessat(AT_FDCWD, "/dev/hvc0", F_OK) != 0;
51 }();
52 return result;
53 }
54
DEFINE_IFUNC_FOR(memchr)55 DEFINE_IFUNC_FOR(memchr) {
56 if (have_fast_v()) RETURN_FUNC(memchr_func_t, memchr_v);
57 RETURN_FUNC(memchr_func_t, memchr_gc);
58 }
59 MEMCHR_SHIM()
60
DEFINE_IFUNC_FOR(memcmp)61 DEFINE_IFUNC_FOR(memcmp) {
62 if (have_fast_v()) RETURN_FUNC(memcmp_func_t, memcmp_v);
63 RETURN_FUNC(memcmp_func_t, memcmp_gc);
64 }
65 MEMCMP_SHIM()
66
DEFINE_IFUNC_FOR(memcpy)67 DEFINE_IFUNC_FOR(memcpy) {
68 if (have_fast_v()) RETURN_FUNC(memcpy_func_t, memcpy_v);
69 RETURN_FUNC(memcpy_func_t, memcpy_gc);
70 }
71 MEMCPY_SHIM()
72
DEFINE_IFUNC_FOR(memmove)73 DEFINE_IFUNC_FOR(memmove) {
74 if (have_fast_v()) RETURN_FUNC(memmove_func_t, memmove_v);
75 RETURN_FUNC(memmove_func_t, memmove_gc);
76 }
77 MEMMOVE_SHIM()
78
DEFINE_IFUNC_FOR(memset)79 DEFINE_IFUNC_FOR(memset) {
80 if (have_fast_v()) RETURN_FUNC(memset_func_t, memset_v);
81 RETURN_FUNC(memset_func_t, memset_gc);
82 }
83 MEMSET_SHIM()
84
DEFINE_IFUNC_FOR(stpcpy)85 DEFINE_IFUNC_FOR(stpcpy) {
86 if (have_fast_v()) RETURN_FUNC(stpcpy_func_t, stpcpy_v);
87 RETURN_FUNC(stpcpy_func_t, stpcpy_gc);
88 }
89 STPCPY_SHIM()
90
DEFINE_IFUNC_FOR(strcat)91 DEFINE_IFUNC_FOR(strcat) {
92 if (have_fast_v()) RETURN_FUNC(strcat_func_t, strcat_v);
93 RETURN_FUNC(strcat_func_t, strcat_gc);
94 }
95 STRCAT_SHIM()
96
DEFINE_IFUNC_FOR(strchr)97 DEFINE_IFUNC_FOR(strchr) {
98 if (have_fast_v()) RETURN_FUNC(strchr_func_t, strchr_v);
99 RETURN_FUNC(strchr_func_t, strchr_gc);
100 }
101 STRCHR_SHIM()
102
DEFINE_IFUNC_FOR(strcmp)103 DEFINE_IFUNC_FOR(strcmp) {
104 if (have_fast_v()) RETURN_FUNC(strcmp_func_t, strcmp_v);
105 RETURN_FUNC(strcmp_func_t, strcmp_gc);
106 }
107 STRCMP_SHIM()
108
DEFINE_IFUNC_FOR(strcpy)109 DEFINE_IFUNC_FOR(strcpy) {
110 if (have_fast_v()) RETURN_FUNC(strcpy_func_t, strcpy_v);
111 RETURN_FUNC(strcpy_func_t, strcpy_gc);
112 }
113 STRCPY_SHIM()
114
DEFINE_IFUNC_FOR(strlen)115 DEFINE_IFUNC_FOR(strlen) {
116 if (have_fast_v()) RETURN_FUNC(strlen_func_t, strlen_v);
117 RETURN_FUNC(strlen_func_t, strlen_gc);
118 }
119 STRLEN_SHIM()
120
DEFINE_IFUNC_FOR(strncat)121 DEFINE_IFUNC_FOR(strncat) {
122 if (have_fast_v()) RETURN_FUNC(strncat_func_t, strncat_v);
123 RETURN_FUNC(strncat_func_t, strncat_gc);
124 }
125 STRNCAT_SHIM()
126
DEFINE_IFUNC_FOR(strncmp)127 DEFINE_IFUNC_FOR(strncmp) {
128 if (have_fast_v()) RETURN_FUNC(strncmp_func_t, strncmp_v);
129 RETURN_FUNC(strncmp_func_t, strncmp_gc);
130 }
131 STRNCMP_SHIM()
132
DEFINE_IFUNC_FOR(strncpy)133 DEFINE_IFUNC_FOR(strncpy) {
134 if (have_fast_v()) RETURN_FUNC(strncpy_func_t, strncpy_v);
135 RETURN_FUNC(strncpy_func_t, strncpy_gc);
136 }
137 STRNCPY_SHIM()
138
DEFINE_IFUNC_FOR(strnlen)139 DEFINE_IFUNC_FOR(strnlen) {
140 if (have_fast_v()) RETURN_FUNC(strnlen_func_t, strnlen_v);
141 RETURN_FUNC(strnlen_func_t, strnlen_gc);
142 }
143 STRNLEN_SHIM()
144
145 } // extern "C"
146