1 /*
2  * lseek() for uClibc
3  *
4  * Copyright (C) 2000-2006 Erik Andersen <andersen@uclibc.org>
5  *
6  * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
7  */
8 
9 #include <sys/syscall.h>
10 #include <unistd.h>
11 #include <cancel.h>
12 
13 #ifdef __NR_lseek
14 # define __NR___lseek_nocancel __NR_lseek
15 _syscall3(off_t, __NC(lseek), int, fd, off_t, offset, int, whence)
16 #elif !defined __NR_lseek && defined __NR_llseek
17 #include <endian.h>
18 off_t __NC(lseek)(int fd, off_t offset, int whence)
19 {
20 #if __WORDSIZE == 32
21 	__off64_t result;
22 	return INLINE_SYSCALL(llseek, 5, fd,
23 			      (long) (((uint64_t) (offset)) >> 32),
24 			      (long) offset, &result, whence) ?: result;
25 #else
26 	return lseek64(fd, offset, whence);
27 #endif
28 /* No need to handle __WORDSIZE == 64 as such a kernel won't define __NR_llseek */
29 }
30 #else
31 # include <errno.h>
32 off_t __NC(lseek)(int fd, off_t offset attribute_unused, int whence)
33 {
34 	if (fd < 0) {
35 		__set_errno(EBADF);
36 		return -1;
37 	}
38 
39 	switch(whence) {
40 		case SEEK_SET:
41 		case SEEK_CUR:
42 		case SEEK_END:
43 		case SEEK_DATA:
44 		case SEEK_HOLE:
45 			break;
46 		default:
47 			__set_errno(EINVAL);
48 			return -1;
49 	}
50 
51 	__set_errno(ENOSYS);
52 	return -1;
53 }
54 #endif
55 CANCELLABLE_SYSCALL(off_t, lseek, (int fd, off_t offset, int whence), (fd, offset, whence))
56 lt_libc_hidden(lseek)
57 #if __WORDSIZE == 64 || (!defined __NR__llseek && !defined __NR_llseek)
58 strong_alias_untyped(__NC(lseek),__NC(lseek64))
59 strong_alias_untyped(lseek,lseek64)
60 lt_strong_alias(lseek64)
61 lt_libc_hidden(lseek64)
62 #endif
63