1 /*
2 * llseek.c -- stub calling the llseek system call
3 *
4 * Copyright (C) 1994, 1995, 1996, 1997 Theodore Ts'o.
5 *
6 * %Begin-Header%
7 * This file may be redistributed under the terms of the
8 * GNU Lesser General Public License.
9 * %End-Header%
10 */
11
12 #ifndef _LARGEFILE_SOURCE
13 #define _LARGEFILE_SOURCE
14 #endif
15 #ifndef _LARGEFILE64_SOURCE
16 #define _LARGEFILE64_SOURCE
17 #endif
18
19 #include "config.h"
20 #if HAVE_SYS_TYPES_H
21 #include <sys/types.h>
22 #endif
23
24 #if HAVE_ERRNO_H
25 #include <errno.h>
26 #endif
27 #if HAVE_UNISTD_H
28 #include <unistd.h>
29 #endif
30 #ifdef __MSDOS__
31 #include <io.h>
32 #endif
33
34 #include "blkidP.h"
35
36 #ifdef __linux__
37
38 #if defined(HAVE_LSEEK64) && defined(HAVE_LSEEK64_PROTOTYPE)
39
40 #define my_llseek lseek64
41
42 #elif defined(HAVE_LLSEEK)
43 #include <sys/syscall.h>
44
45 #ifndef HAVE_LLSEEK_PROTOTYPE
46 extern long long llseek(int fd, long long offset, int origin);
47 #endif
48
49 #define my_llseek llseek
50
51 #else /* ! HAVE_LLSEEK */
52
53 #if SIZEOF_LONG == SIZEOF_LONG_LONG
54
55 #define llseek lseek
56
57 #else /* SIZEOF_LONG != SIZEOF_LONG_LONG */
58
59 #include <linux/unistd.h>
60
61 #ifndef __NR__llseek
62 #define __NR__llseek 140
63 #endif
64
65 #ifndef __i386__
66 static int _llseek(unsigned int, unsigned long, unsigned long,
67 blkid_loff_t *, unsigned int);
68
_syscall5(int,_llseek,unsigned int,fd,unsigned long,offset_high,unsigned long,offset_low,blkid_loff_t *,result,unsigned int,origin)69 static _syscall5(int, _llseek, unsigned int, fd, unsigned long, offset_high,
70 unsigned long, offset_low, blkid_loff_t *, result,
71 unsigned int, origin)
72 #endif
73
74 static blkid_loff_t my_llseek(int fd, blkid_loff_t offset, int origin)
75 {
76 blkid_loff_t result;
77 int retval;
78
79 #ifndef __i386__
80 retval = _llseek(fd, ((unsigned long long) offset) >> 32,
81 ((unsigned long long)offset) & 0xffffffff,
82 &result, origin);
83 #else
84 retval = syscall(__NR__llseek, fd, ((unsigned long long) offset) >> 32,
85 ((unsigned long long)offset) & 0xffffffff,
86 &result, origin);
87 #endif
88 return (retval == -1 ? (blkid_loff_t) retval : result);
89 }
90
91 #endif /* __alpha__ || __ia64__ */
92
93 #endif /* HAVE_LLSEEK */
94
blkid_llseek(int fd,blkid_loff_t offset,int whence)95 blkid_loff_t blkid_llseek(int fd, blkid_loff_t offset, int whence)
96 {
97 blkid_loff_t result;
98 static int do_compat = 0;
99
100 if ((sizeof(off_t) >= sizeof(blkid_loff_t)) ||
101 (offset < ((blkid_loff_t) 1 << ((sizeof(off_t)*8) -1))))
102 return lseek(fd, (off_t) offset, whence);
103
104 if (do_compat) {
105 errno = EOVERFLOW;
106 return -1;
107 }
108
109 result = my_llseek(fd, offset, whence);
110 if (result == -1 && errno == ENOSYS) {
111 /*
112 * Just in case this code runs on top of an old kernel
113 * which does not support the llseek system call
114 */
115 do_compat++;
116 errno = EOVERFLOW;
117 }
118 return result;
119 }
120
121 #else /* !linux */
122
123 #ifndef EOVERFLOW
124 #ifdef EXT2_ET_INVALID_ARGUMENT
125 #define EOVERFLOW EXT2_ET_INVALID_ARGUMENT
126 #else
127 #define EOVERFLOW 112
128 #endif
129 #endif
130
blkid_llseek(int fd,blkid_loff_t offset,int origin)131 blkid_loff_t blkid_llseek(int fd, blkid_loff_t offset, int origin)
132 {
133 #if defined(HAVE_LSEEK64) && defined(HAVE_LSEEK64_PROTOTYPE)
134 return lseek64 (fd, offset, origin);
135 #else
136 if ((sizeof(off_t) < sizeof(blkid_loff_t)) &&
137 (offset >= ((blkid_loff_t) 1 << ((sizeof(off_t)*8) - 1)))) {
138 errno = EOVERFLOW;
139 return -1;
140 }
141 return lseek(fd, (off_t) offset, origin);
142 #endif
143 }
144
145 #endif /* linux */
146
147
148