1 /*
2 * Copyright (C) 2000-2006 Erik Andersen <andersen@uclibc.org>
3 *
4 * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
5 */
6 /* Massivly hacked up for uClibc by Erik Andersen */
7
8 #include <_lfs_64.h>
9 #include <stdint.h>
10 #include <sys/syscall.h>
11 #include <errno.h>
12 #include <sys/mman.h>
13
14 #ifndef __NR_mmap2
15
16 /*
17 * This version is a stub that just chops off everything at the mmap 32 bit
18 * mmap() address space... You will probably need to add in an arch specific
19 * implementation to override this as there is not a generic way for me to
20 * implement this particular syscall if your arch lacks _syscall6...
21 *
22 */
23
mmap64(void * addr,size_t len,int prot,int flags,int fd,__off64_t offset)24 void *mmap64(void *addr, size_t len, int prot, int flags, int fd, __off64_t offset)
25 {
26 if (offset != (off_t) offset ||
27 (offset + len) != (off_t) (offset + len)) {
28 __set_errno(EINVAL);
29 return MAP_FAILED;
30 }
31
32 return mmap(addr, len, prot, flags, fd, (off_t) offset);
33 }
34
35 #else
36 # include <bits/uClibc_page.h>
37
38 /* Some architectures always use 12 as page shift for mmap2() even though the
39 * real PAGE_SHIFT != 12. Other architectures use the same value as
40 * PAGE_SHIFT...
41 */
42 # ifndef MMAP2_PAGE_SHIFT
43 # define MMAP2_PAGE_SHIFT 12
44 # endif
45
mmap64(void * addr,size_t len,int prot,int flags,int fd,__off64_t offset)46 void *mmap64(void *addr, size_t len, int prot, int flags, int fd, __off64_t offset)
47 {
48 /*
49 * Some arches check the size in INLINE_SYSCALL() and barf if it's
50 * too big (i.e. a 64bit value getting truncated to 32bit).
51 */
52 # if __WORDSIZE == 32
53 uint32_t sysoff;
54 # else
55 uint64_t sysoff;
56 # endif
57
58 if (offset & ((1 << MMAP2_PAGE_SHIFT) - 1)) {
59 __set_errno(EINVAL);
60 return MAP_FAILED;
61 }
62
63 /*
64 * We know __off64_t is always a signed 64-bit type, but need things
65 * to be unsigned before doing the shift. If it isn't, we might
66 * sign extend things and pass in the wrong value. So cast it to
67 * an unsigned 64-bit value before doing the shift.
68 */
69 sysoff = (uint64_t)offset >> MMAP2_PAGE_SHIFT;
70
71 return (void*) INLINE_SYSCALL(mmap2, 6, addr, len, prot, flags, fd, sysoff);
72 }
73
74 #endif
75