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
|
/* Copyright (C) 2000, 2003 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <sysdep.h>
#define EINVAL 22
#define ENOSYS 38
#include "kernel-features.h"
/* The mmap2 system call takes six arguments, all in registers. */
.text
ENTRY (__mmap64)
#ifdef __NR_mmap2
ldr ip, [sp, $4] @ offset low part
str r5, [sp, #-4]!
ldr r5, [sp, $12] @ offset high part
str r4, [sp, #-4]!
movs r4, ip, lsl $20 @ check that offset is page-aligned
mov ip, ip, lsr $12
moveqs r4, r5, lsr $12 @ check for overflow
bne .Linval
ldr r4, [sp, $8] @ load fd
orr r5, ip, r5, lsl $20 @ compose page offset
mov ip, r0
swi SYS_ify (mmap2)
cmn r0, $4096
# ifdef __ASSUME_MMAP2_SYSCALL
ldr r4, [sp], #4
ldr r5, [sp], #4
RETINSTR(movcc, pc, lr)
b PLTJMP(syscall_error)
# else
ldrcc r4, [sp], #4
ldrcc r5, [sp], #4
RETINSTR(movcc, pc, lr)
cmn r0, $ENOSYS
bne .Lerror
/* The current kernel does not support mmap2. Fall back to plain
mmap if the offset is small enough. */
ldr r5, [sp, $16]
mov r0, ip @ first arg was clobbered
teq r5, $0
ldreq r4, [sp], #4
ldreq r5, [sp], #4
beq PLTJMP(__mmap)
# endif
.Linval:
mov r0, $-EINVAL
.Lerror:
ldr r4, [sp], #4
ldr r5, [sp], #4
b PLTJMP(syscall_error)
#else
/* The kernel headers do not support mmap2. Fall back to plain
mmap if the offset is small enough. */
ldr ip, [sp, $8]
teq ip, $0
beq PLTJMP(__mmap)
mov r0, $-EINVAL
b PLTJMP(syscall_error)
#endif
PSEUDO_END (__mmap64)
weak_alias (__mmap64, mmap64)
|
