about summary refs log tree commit diff
path: root/sysdeps/unix/sysv/linux/i386/mmap64.S
blob: 72e216a5ae2a9cfcce322a132e0206ece6e7d8e0 (plain) (blame)
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
/* Copyright (C) 1995,96,97,98,99,2000,2002,2005,2006
	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, see
   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>
#include <bp-sym.h>
#include <bp-asm.h>

#include <kernel-features.h>

#define EINVAL	22
#define ENOSYS	38

#define SVRSP	16		/* saved register space */
#define PARMS	LINKAGE+SVRSP	/* space for 4 saved regs */
#define ADDR	PARMS
#define LEN	ADDR+PTR_SIZE
#define PROT	LEN+4
#define FLAGS	PROT+4
#define FD	FLAGS+4
#define OFFLO	FD+4
#define OFFHI	OFFLO+4

	.text
ENTRY (BP_SYM (__mmap64))

#ifdef __NR_mmap2

	/* Save registers.  */
	pushl %ebp
	cfi_adjust_cfa_offset (4)
	pushl %ebx
	cfi_adjust_cfa_offset (4)
	pushl %esi
	cfi_adjust_cfa_offset (4)
	pushl %edi
	cfi_adjust_cfa_offset (4)

	movl OFFLO(%esp), %edx
	movl OFFHI(%esp), %ecx
	testl $0xfff, %edx
	jne L(einval)
	shrdl $12, %ecx, %edx		/* mmap2 takes the offset in pages.  */
	shrl $12, %ecx
	jne L(einval)
	movl %edx, %ebp
	cfi_rel_offset (ebp, 12)

	movl ADDR(%esp), %ebx
	cfi_rel_offset (ebx, 8)
	movl LEN(%esp), %ecx
	movl PROT(%esp), %edx
	movl FLAGS(%esp), %esi
	cfi_rel_offset (esi, 4)
	movl FD(%esp), %edi
	cfi_rel_offset (edi, 0)

	movl $SYS_ify(mmap2), %eax	/* System call number in %eax.  */

	/* Do the system call trap.  */
L(do_syscall):
	ENTER_KERNEL

	/* Restore registers.  */
	popl %edi
	cfi_adjust_cfa_offset (-4)
	cfi_restore (edi)
	popl %esi
	cfi_adjust_cfa_offset (-4)
	cfi_restore (esi)
	popl %ebx
	cfi_adjust_cfa_offset (-4)
	cfi_restore (ebx)
	popl %ebp
	cfi_adjust_cfa_offset (-4)
	cfi_restore (ebp)

#ifndef __ASSUME_MMAP2_SYSCALL
2:
	cmp $-ENOSYS, %eax
	je 3f
#endif

	/* If 0 > %eax > -4096 there was an error.  */
	cmpl $-4096, %eax
	ja SYSCALL_ERROR_LABEL

	/* Successful; return the syscall's value.  */
L(pseudo_end):
	ret

	cfi_adjust_cfa_offset (16)
	cfi_rel_offset (ebp, 12)
	cfi_rel_offset (ebx, 8)
	cfi_rel_offset (esi, 4)
	cfi_rel_offset (edi, 0)
	/* This means the offset value is too large.  */
L(einval):
	popl %edi
	cfi_adjust_cfa_offset (-4)
	cfi_restore (edi)
	popl %esi
	cfi_adjust_cfa_offset (-4)
	cfi_restore (esi)
	popl %ebx
	cfi_adjust_cfa_offset (-4)
	cfi_restore (ebx)
	popl %ebp
	cfi_adjust_cfa_offset (-4)
	cfi_restore (ebp)
	movl $-EINVAL, %eax
	jmp SYSCALL_ERROR_LABEL
#endif

#if !defined __ASSUME_MMAP2_SYSCALL || !defined __NR_mmap2
3:
	/* Save registers.  */
	movl %ebx, %edx
	cfi_register (ebx, edx)

	cmpl $0, OFFHI-SVRSP(%esp)
	jne L(einval2)

	movl $SYS_ify(mmap), %eax	/* System call number in %eax.  */

	lea ADDR-SVRSP(%esp), %ebx	/* Address of args is 1st arg.  */

	/* Do the system call trap.  */
	ENTER_KERNEL

	/* Restore registers.  */
	movl %edx, %ebx
	cfi_restore (ebx)

	/* If 0 > %eax > -4096 there was an error.  */
	cmpl $-4096, %eax
	ja SYSCALL_ERROR_LABEL

	/* Successful; return the syscall's value.  */
#ifndef __NR_mmap2
L(pseudo_end):
#endif
	ret

	cfi_register (ebx, edx)
L(einval2):
	movl %edx, %ebx
	cfi_restore (ebx)
	movl $-EINVAL, %eax
	jmp SYSCALL_ERROR_LABEL
#endif

PSEUDO_END (BP_SYM (__mmap64))

weak_alias (BP_SYM (__mmap64), BP_SYM (mmap64))