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
191
192
193
194
195
196
|
/* 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 <endian.h>
#ifndef __UCLIBC_HAS_LFS__
# define off64_t off_t
#endif
#ifdef __NR_pread64 /* Newer kernels renamed but it's the same. */
# ifdef __NR_pread
# error "__NR_pread and __NR_pread64 both defined???"
# endif
# define __NR_pread __NR_pread64
#endif
#ifdef __NR_pread
extern __typeof(pread) __libc_pread;
# define __NR___syscall_pread __NR_pread
static __inline__ _syscall6(ssize_t, __syscall_pread, int, fd,
void *, buf, size_t, count, int, dummy, 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, 0, __LONG_LONG_PAIR(offset >> 31, offset)));
}
weak_alias(__libc_pread,pread)
# ifdef __UCLIBC_HAS_LFS__
extern __typeof(pread64) __libc_pread64;
ssize_t __libc_pread64(int fd, void *buf, size_t count, off64_t offset)
{
return(__syscall_pread(fd, buf, count, 0, __LONG_LONG_PAIR(offset >> 32, offset)));
}
weak_alias(__libc_pread64,pread64)
# endif /* __UCLIBC_HAS_LFS__ */
#endif /* __NR_pread */
#ifdef __NR_pwrite64 /* Newer kernels renamed but it's the same. */
# ifdef __NR_pwrite
# error "__NR_pwrite and __NR_pwrite64 both defined???"
# endif
# define __NR_pwrite __NR_pwrite64
#endif
#ifdef __NR_pwrite
extern __typeof(pwrite) __libc_pwrite;
# define __NR___syscall_pwrite __NR_pwrite
static __inline__ _syscall6(ssize_t, __syscall_pwrite, int, fd,
const void *, buf, size_t, count, int, dummy, 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, 0, __LONG_LONG_PAIR(offset >> 31, offset)));
}
weak_alias(__libc_pwrite,pwrite)
# ifdef __UCLIBC_HAS_LFS__
extern __typeof(pwrite64) __libc_pwrite64;
ssize_t __libc_pwrite64(int fd, const void *buf, size_t count, off64_t offset)
{
return(__syscall_pwrite(fd, buf, count, 0, __LONG_LONG_PAIR(offset >> 32, offset)));
}
weak_alias(__libc_pwrite64,pwrite64)
# endif /* __UCLIBC_HAS_LFS__ */
#endif /* __NR_pwrite */
#if ! defined __NR_pread || ! defined __NR_pwrite
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__
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);
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);
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);
ssize_t __libc_pwrite(int fd, const void *buf, size_t count, off_t offset)
{
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);
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 */
|
