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1 /*
2  * Copyright (C) 2008 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 <sys/cdefs.h>
32 #include <sys/types.h>
33 #include <linux/memfd.h>
34 #include <linux/mman.h>
35 #include <linux/uio.h>
36 
37 __BEGIN_DECLS
38 
39 /** Alternative spelling of the `MAP_ANONYMOUS` flag for mmap(). */
40 #define MAP_ANON MAP_ANONYMOUS
41 
42 /** Return value for mmap(). */
43 #define MAP_FAILED __BIONIC_CAST(reinterpret_cast, void*, -1)
44 
45 /**
46  * [mmap(2)](http://man7.org/linux/man-pages/man2/mmap.2.html)
47  * creates a memory mapping for the given range.
48  *
49  * Returns the address of the mapping on success,
50  * and returns `MAP_FAILED` and sets `errno` on failure.
51  */
52 #if defined(__USE_FILE_OFFSET64)
53 void* mmap(void* __addr, size_t __size, int __prot, int __flags, int __fd, off_t __offset) __RENAME(mmap64);
54 #else
55 void* mmap(void* __addr, size_t __size, int __prot, int __flags, int __fd, off_t __offset);
56 #endif
57 
58 /**
59  * mmap64() is a variant of mmap() that takes a 64-bit offset even on LP32.
60  *
61  * See https://android.googlesource.com/platform/bionic/+/master/docs/32-bit-abi.md
62  *
63  * Available since API level 21.
64  */
65 void* mmap64(void* __addr, size_t __size, int __prot, int __flags, int __fd, off64_t __offset) __INTRODUCED_IN(21);
66 
67 /**
68  * [munmap(2)](http://man7.org/linux/man-pages/man2/munmap.2.html)
69  * deletes a memory mapping for the given range.
70  *
71  * Returns 0 on success, and returns -1 and sets `errno` on failure.
72  */
73 int munmap(void* __addr, size_t __size);
74 
75 /**
76  * [msync(2)](http://man7.org/linux/man-pages/man2/msync.2.html)
77  * flushes changes to a memory-mapped file to disk.
78  *
79  * Returns 0 on success, and returns -1 and sets `errno` on failure.
80  */
81 int msync(void* __addr, size_t __size, int __flags);
82 
83 /**
84  * [mprotect(2)](http://man7.org/linux/man-pages/man2/mprotect.2.html)
85  * sets the protection on a memory region.
86  *
87  * Returns 0 on success, and returns -1 and sets `errno` on failure.
88  */
89 int mprotect(void* __addr, size_t __size, int __prot);
90 
91 /** Flag for mremap(). */
92 #define MREMAP_MAYMOVE  1
93 
94 /** Flag for mremap(). */
95 #define MREMAP_FIXED    2
96 
97 /**
98  * [mremap(2)](http://man7.org/linux/man-pages/man2/mremap.2.html)
99  * expands or shrinks an existing memory mapping.
100  *
101  * Returns the address of the mapping on success,
102  * and returns `MAP_FAILED` and sets `errno` on failure.
103  */
104 void* mremap(void* __old_addr, size_t __old_size, size_t __new_size, int __flags, ...);
105 
106 /**
107  * [mlockall(2)](http://man7.org/linux/man-pages/man2/mlockall.2.html)
108  * locks pages (preventing swapping).
109  *
110  * Available since API level 17.
111  *
112  * Returns 0 on success, and returns -1 and sets `errno` on failure.
113  */
114 int mlockall(int __flags) __INTRODUCED_IN(17);
115 
116 /**
117  * [munlockall(2)](http://man7.org/linux/man-pages/man2/munlockall.2.html)
118  * unlocks pages (allowing swapping).
119  *
120  * Available since API level 17.
121  *
122  * Returns 0 on success, and returns -1 and sets `errno` on failure.
123  */
124 int munlockall(void) __INTRODUCED_IN(17);
125 
126 /**
127  * [mlock(2)](http://man7.org/linux/man-pages/man2/mlock.2.html)
128  * locks pages (preventing swapping).
129  *
130  * Returns 0 on success, and returns -1 and sets `errno` on failure.
131  */
132 int mlock(const void* __addr, size_t __size);
133 
134 /**
135  * [mlock2(2)](http://man7.org/linux/man-pages/man2/mlock.2.html)
136  * locks pages (preventing swapping), with optional flags.
137  *
138  * Available since API level 30.
139  *
140  * Returns 0 on success, and returns -1 and sets `errno` on failure.
141  */
142 int mlock2(const void* __addr, size_t __size, int __flags) __INTRODUCED_IN(30);
143 
144 /**
145  * [munlock(2)](http://man7.org/linux/man-pages/man2/munlock.2.html)
146  * unlocks pages (allowing swapping).
147  *
148  * Returns 0 on success, and returns -1 and sets `errno` on failure.
149  */
150 int munlock(const void* __addr, size_t __size);
151 
152 /**
153  * [mincore(2)](http://man7.org/linux/man-pages/man2/mincore.2.html)
154  * tests whether pages are resident in memory.
155  *
156  * Returns 0 on success, and returns -1 and sets `errno` on failure.
157  */
158 int mincore(void* __addr, size_t __size, unsigned char* __vector);
159 
160 /**
161  * [madvise(2)](http://man7.org/linux/man-pages/man2/madvise.2.html)
162  * gives the kernel advice about future usage patterns.
163  *
164  * Returns 0 on success, and returns -1 and sets `errno` on failure.
165  */
166 int madvise(void* __addr, size_t __size, int __advice);
167 
168 /**
169  * [process_madvise(2)](http://man7.org/linux/man-pages/man2/process_madvise.2.html)
170  * works just like madvise(2) but applies to the process specified by the given
171  * PID file descriptor.
172  *
173  * Available since API level 31. Its sibling process_mrelease() does not have a
174  * libc wrapper and should be called using syscall() instead. Given the lack of
175  * widespread applicability of this system call and the absence of wrappers in
176  * other libcs, it was probably a mistake to have added this wrapper to bionic.
177  *
178  * Returns the number of bytes advised on success, and returns -1 and sets `errno` on failure.
179  */
180 ssize_t process_madvise(int __pid_fd, const struct iovec* __iov, size_t __count, int __advice, unsigned __flags) __INTRODUCED_IN(31);
181 
182 #if defined(__USE_GNU)
183 
184 /**
185  * [memfd_create(2)](http://man7.org/linux/man-pages/man2/memfd_create.2.html)
186  * creates an anonymous file.
187  *
188  * Available since API level 30.
189  *
190  * Returns an fd on success, and returns -1 and sets `errno` on failure.
191  */
192 int memfd_create(const char* __name, unsigned __flags) __INTRODUCED_IN(30);
193 
194 #endif
195 
196 #if __ANDROID_API__ >= 23
197 
198 /*
199  * Some third-party code uses the existence of POSIX_MADV_NORMAL to detect the
200  * availability of posix_madvise. This is not correct, since having up-to-date
201  * UAPI headers says nothing about the C library, but for the time being we
202  * don't want to harm adoption of the unified headers.
203  *
204  * https://github.com/android-ndk/ndk/issues/395
205  */
206 
207 /** Flag for posix_madvise(). */
208 #define POSIX_MADV_NORMAL     MADV_NORMAL
209 /** Flag for posix_madvise(). */
210 #define POSIX_MADV_RANDOM     MADV_RANDOM
211 /** Flag for posix_madvise(). */
212 #define POSIX_MADV_SEQUENTIAL MADV_SEQUENTIAL
213 /** Flag for posix_madvise(). */
214 #define POSIX_MADV_WILLNEED   MADV_WILLNEED
215 /** Flag for posix_madvise(). */
216 #define POSIX_MADV_DONTNEED   MADV_DONTNEED
217 
218 #endif
219 
220 /**
221  * [posix_madvise(3)](http://man7.org/linux/man-pages/man3/posix_madvise.3.html)
222  * gives the kernel advice about future usage patterns.
223  *
224  * Available since API level 23.
225  * See also madvise() which is available at all API levels.
226  *
227  * Returns 0 on success, and returns a positive error number on failure.
228  */
229 int posix_madvise(void* __addr, size_t __size, int __advice) __INTRODUCED_IN(23);
230 
231 __END_DECLS
232