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 #include <errno.h>
30 #include <fcntl.h>
31 #include <stdarg.h>
32 #include <sys/resource.h>
33 #include <sys/types.h>
34 #include <sys/vfs.h>
35 #include <unistd.h>
36
37 #if __LP64__
38 #error This code is only needed on 32-bit systems!
39 #endif
40
41 // System calls we need.
42 extern "C" int __fcntl64(int, int, void*);
43 extern "C" int __fstatfs64(int, size_t, struct statfs*);
44 extern "C" int __llseek(int, unsigned long, unsigned long, off64_t*, int);
45 extern "C" int __statfs64(const char*, size_t, struct statfs*);
46
47 // For fcntl we use the fcntl64 system call to signal that we're using struct flock64.
fcntl(int fd,int cmd,...)48 int fcntl(int fd, int cmd, ...) {
49 va_list ap;
50
51 va_start(ap, cmd);
52 void* arg = va_arg(ap, void*);
53 va_end(ap);
54
55 return __fcntl64(fd, cmd, arg);
56 }
57
58 // For fstatfs we need to add the extra argument giving the kernel the size of the buffer.
fstatfs(int fd,struct statfs * stat)59 int fstatfs(int fd, struct statfs* stat) {
60 return __fstatfs64(fd, sizeof(*stat), stat);
61 }
62 __strong_alias(fstatfs64, fstatfs);
63
64 // For statfs we need to add the extra argument giving the kernel the size of the buffer.
statfs(const char * path,struct statfs * stat)65 int statfs(const char* path, struct statfs* stat) {
66 return __statfs64(path, sizeof(*stat), stat);
67 }
68 __strong_alias(statfs64, statfs);
69
70 // For lseek64 we need to use the llseek system call which splits the off64_t in two and
71 // returns the off64_t result via a pointer because 32-bit kernels can't return 64-bit results.
lseek64(int fd,off64_t off,int whence)72 off64_t lseek64(int fd, off64_t off, int whence) {
73 off64_t result;
74 unsigned long off_hi = static_cast<unsigned long>(off >> 32);
75 unsigned long off_lo = static_cast<unsigned long>(off);
76 if (__llseek(fd, off_hi, off_lo, &result, whence) < 0) {
77 return -1;
78 }
79 return result;
80 }
81
82 // There is no pread for 32-bit off_t, so we need to widen and call pread64.
pread(int fd,void * buf,size_t byte_count,off_t offset)83 ssize_t pread(int fd, void* buf, size_t byte_count, off_t offset) {
84 return pread64(fd, buf, byte_count, static_cast<off64_t>(offset));
85 }
86
87 // There is no pwrite for 32-bit off_t, so we need to widen and call pwrite64.
pwrite(int fd,const void * buf,size_t byte_count,off_t offset)88 ssize_t pwrite(int fd, const void* buf, size_t byte_count, off_t offset) {
89 return pwrite64(fd, buf, byte_count, static_cast<off64_t>(offset));
90 }
91
92 // There is no fallocate for 32-bit off_t, so we need to widen and call fallocate64.
fallocate(int fd,int mode,off_t offset,off_t length)93 int fallocate(int fd, int mode, off_t offset, off_t length) {
94 return fallocate64(fd, mode, static_cast<off64_t>(offset), static_cast<off64_t>(length));
95 }
96
97 // There is no getrlimit64 system call, so we need to use prlimit64.
getrlimit64(int resource,rlimit64 * limits64)98 int getrlimit64(int resource, rlimit64* limits64) {
99 return prlimit64(0, resource, NULL, limits64);
100 }
101
102 // There is no setrlimit64 system call, so we need to use prlimit64.
setrlimit64(int resource,const rlimit64 * limits64)103 int setrlimit64(int resource, const rlimit64* limits64) {
104 return prlimit64(0, resource, limits64, NULL);
105 }
106