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
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
#include "efence.h"
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
/*
* Lots of systems are missing the definition of PROT_NONE.
*/
#ifndef PROT_NONE
#define PROT_NONE 0
#endif
/*
* 386 BSD has MAP_ANON instead of MAP_ANONYMOUS.
*/
#if ( !defined(MAP_ANONYMOUS) && defined(MAP_ANON) )
#define MAP_ANONYMOUS MAP_ANON
#endif
/*
* For some reason, I can't find mprotect() in any of the headers on
* IRIX or SunOS 4.1.2
*/
/* extern C_LINKAGE int mprotect(void * addr, size_t len, int prot); */
//#ifdef _64BIT_PLATFORM
static caddr_t startAddr = (caddr_t) 0xc00000000000;
//#else
//static caddr_t startAddr = (caddr_t) 0;
//#endif
#if ( !defined(sgi) && !defined(_AIX) )
extern int sys_nerr;
/*extern char * sys_errlist[];*/
#endif
static const char *
stringErrorReport(void)
{
#if ( defined(sgi) )
return strerror(oserror());
#elif ( defined(_AIX) )
return strerror(errno);
#else
//if ( errno > 0 && errno < sys_nerr )
return "Unknown error.\n";
//return sys_errlist[errno];
//else
//return "Unknown error.\n";
#endif
}
/*
* Create memory.
*/
#if defined(MAP_ANONYMOUS)
void *
Page_Create(size_t size)
{
caddr_t allocation;
/*
* In this version, "startAddr" is a _hint_, not a demand.
* When the memory I map here is contiguous with other
* mappings, the allocator can coalesce the memory from two
* or more mappings into one large contiguous chunk, and thus
* might be able to find a fit that would not otherwise have
* been possible. I could _force_ it to be contiguous by using
* the MMAP_FIXED flag, but I don't want to stomp on memory mappings
* generated by other software, etc.
*/
allocation = (caddr_t) mmap(
startAddr
,size
,PROT_READ|PROT_WRITE
,MAP_PRIVATE|MAP_ANONYMOUS
,-1
,0);
#ifndef __hpux
/*
* Set the "address hint" for the next mmap() so that it will abut
* the mapping we just created.
*
* HP/UX 9.01 has a kernel bug that makes mmap() fail sometimes
* when given a non-zero address hint, so we'll leave the hint set
* to zero on that system. HP recently told me this is now fixed.
* Someone please tell me when it is probable to assume that most
* of those systems that were running 9.01 have been upgraded.
*/
startAddr = allocation + size;
#endif
if ( allocation == (caddr_t)-1 )
EF_Exit("mmap() failed: %s", stringErrorReport());
return (void *)allocation;
}
#else
void *
Page_Create(size_t size)
{
static int devZeroFd = -1;
caddr_t allocation;
if ( devZeroFd == -1 ) {
devZeroFd = open("/dev/zero", O_RDWR);
if ( devZeroFd < 0 )
EF_Exit(
"open() on /dev/zero failed: %s"
,stringErrorReport());
}
/*
* In this version, "startAddr" is a _hint_, not a demand.
* When the memory I map here is contiguous with other
* mappings, the allocator can coalesce the memory from two
* or more mappings into one large contiguous chunk, and thus
* might be able to find a fit that would not otherwise have
* been possible. I could _force_ it to be contiguous by using
* the MMAP_FIXED flag, but I don't want to stomp on memory mappings
* generated by other software, etc.
*/
allocation = (caddr_t) mmap(
startAddr
,size
,PROT_READ|PROT_WRITE
,MAP_PRIVATE
,devZeroFd
,0);
startAddr = allocation + size;
if ( allocation == (caddr_t)-1 )
EF_Exit("mmap() failed: %s", stringErrorReport());
return (void *)allocation;
}
#endif
static void
mprotectFailed(void)
{
EF_Exit("mprotect() failed: %s", stringErrorReport());
}
void
Page_AllowAccess(void * address, size_t size)
{
if ( mprotect((caddr_t)address, size, PROT_READ|PROT_WRITE) < 0 )
mprotectFailed();
}
void
Page_DenyAccess(void * address, size_t size)
{
if ( mprotect((caddr_t)address, size, PROT_NONE) < 0 )
mprotectFailed();
}
void
Page_Delete(void * address, size_t size)
{
Page_DenyAccess(address, size);
}
#if defined(_SC_PAGESIZE)
size_t
Page_Size(void)
{
return (size_t)sysconf(_SC_PAGESIZE);
}
#elif defined(_SC_PAGE_SIZE)
size_t
Page_Size(void)
{
return (size_t)sysconf(_SC_PAGE_SIZE);
}
#else
/* extern int getpagesize(); */
size_t
Page_Size(void)
{
return getpagesize();
}
#endif
|
