1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
|
/* vi: set sw=4 ts=4: */
/*
* Copyright (C) 2000-2006 Erik Andersen <andersen@uclibc.org>
*
* Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
*/
/*
* Based in part on the files
* ./sysdeps/unix/sysv/linux/pwrite.c,
* ./sysdeps/unix/sysv/linux/pread.c,
* sysdeps/posix/pread.c
* sysdeps/posix/pwrite.c
* from GNU libc 2.2.5, but reworked considerably...
*/
#include <sys/syscall.h>
#include <unistd.h>
#include <stdint.h>
extern __typeof(pread) __libc_pread;
extern __typeof(pwrite) __libc_pwrite;
#ifdef __UCLIBC_HAS_LFS__
extern __typeof(pread64) __libc_pread64;
extern __typeof(pwrite64) __libc_pwrite64;
#endif
#include <bits/kernel_types.h>
#ifdef __NR_pread
# define __NR___syscall_pread __NR_pread
static inline _syscall5(ssize_t, __syscall_pread, int, fd, void *, buf,
size_t, count, off_t, offset_hi, off_t, offset_lo);
ssize_t __libc_pread(int fd, void *buf, size_t count, off_t offset)
{
return __syscall_pread(fd, buf, count, __LONG_LONG_PAIR(offset >> 31, offset));
}
weak_alias(__libc_pread,pread)
# ifdef __UCLIBC_HAS_LFS__
ssize_t __libc_pread64(int fd, void *buf, size_t count, off64_t offset)
{
uint32_t low = offset & 0xffffffff;
uint32_t high = offset >> 32;
return __syscall_pread(fd, buf, count, __LONG_LONG_PAIR(high, low));
}
weak_alias(__libc_pread64,pread64)
# endif /* __UCLIBC_HAS_LFS__ */
#endif /* __NR_pread */
#ifdef __NR_pwrite
# define __NR___syscall_pwrite __NR_pwrite
static inline _syscall5(ssize_t, __syscall_pwrite, int, fd, const void *, buf,
size_t, count, off_t, offset_hi, off_t, offset_lo);
ssize_t __libc_pwrite(int fd, const void *buf, size_t count, off_t offset)
{
return __syscall_pwrite(fd, buf, count, __LONG_LONG_PAIR(offset >> 31, offset));
}
weak_alias(__libc_pwrite,pwrite)
# ifdef __UCLIBC_HAS_LFS__
ssize_t __libc_pwrite64(int fd, const void *buf, size_t count, off64_t offset)
{
uint32_t low = offset & 0xffffffff;
uint32_t high = offset >> 32;
return __syscall_pwrite(fd, buf, count, __LONG_LONG_PAIR(high, low));
}
weak_alias(__libc_pwrite64,pwrite64)
# endif /* __UCLIBC_HAS_LFS__ */
#endif /* __NR_pwrite */
#if ! defined __NR_pread || ! defined __NR_pwrite
libc_hidden_proto(read)
libc_hidden_proto(write)
libc_hidden_proto(lseek)
static ssize_t __fake_pread_write(int fd, void *buf,
size_t count, off_t offset, int do_pwrite)
{
int save_errno;
ssize_t result;
off_t old_offset;
/* Since we must not change the file pointer preserve the
* value so that we can restore it later. */
if ((old_offset=lseek(fd, 0, SEEK_CUR)) == (off_t) -1)
return -1;
/* Set to wanted position. */
if (lseek(fd, offset, SEEK_SET) == (off_t) -1)
return -1;
if (do_pwrite == 1) {
/* Write the data. */
result = write(fd, buf, count);
} else {
/* Read the data. */
result = read(fd, buf, count);
}
/* Now we have to restore the position. If this fails we
* have to return this as an error. */
save_errno = errno;
if (lseek(fd, old_offset, SEEK_SET) == (off_t) -1)
{
if (result == -1)
__set_errno(save_errno);
return -1;
}
__set_errno(save_errno);
return(result);
}
# ifdef __UCLIBC_HAS_LFS__
libc_hidden_proto(lseek64)
static ssize_t __fake_pread_write64(int fd, void *buf,
size_t count, off64_t offset, int do_pwrite)
{
int save_errno;
ssize_t result;
off64_t old_offset;
/* Since we must not change the file pointer preserve the
* value so that we can restore it later. */
if ((old_offset=lseek64(fd, 0, SEEK_CUR)) == (off64_t) -1)
return -1;
/* Set to wanted position. */
if (lseek64(fd, offset, SEEK_SET) == (off64_t) -1)
return -1;
if (do_pwrite == 1) {
/* Write the data. */
result = write(fd, buf, count);
} else {
/* Read the data. */
result = read(fd, buf, count);
}
/* Now we have to restore the position. */
save_errno = errno;
if (lseek64(fd, old_offset, SEEK_SET) == (off64_t) -1) {
if (result == -1)
__set_errno (save_errno);
return -1;
}
__set_errno (save_errno);
return result;
}
# endif /* __UCLIBC_HAS_LFS__ */
#endif /* ! defined __NR_pread || ! defined __NR_pwrite */
#ifndef __NR_pread
ssize_t __libc_pread(int fd, void *buf, size_t count, off_t offset)
{
return __fake_pread_write(fd, buf, count, offset, 0);
}
weak_alias(__libc_pread,pread)
# ifdef __UCLIBC_HAS_LFS__
ssize_t __libc_pread64(int fd, void *buf, size_t count, off64_t offset)
{
return __fake_pread_write64(fd, buf, count, offset, 0);
}
weak_alias(__libc_pread64,pread64)
# endif /* __UCLIBC_HAS_LFS__ */
#endif /* ! __NR_pread */
#ifndef __NR_pwrite
ssize_t __libc_pwrite(int fd, const void *buf, size_t count, off_t offset)
{
/* we won't actually be modifying the buffer,
*just cast it to get rid of warnings */
return __fake_pread_write(fd, (void*)buf, count, offset, 1);
}
weak_alias(__libc_pwrite,pwrite)
# ifdef __UCLIBC_HAS_LFS__
ssize_t __libc_pwrite64(int fd, const void *buf, size_t count, off64_t offset)
{
return __fake_pread_write64(fd, (void*)buf, count, offset, 1);
}
weak_alias(__libc_pwrite64,pwrite64)
# endif /* __UCLIBC_HAS_LFS__ */
#endif /* ! __NR_pwrite */
|
