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
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
|
/* Support for memory-mapped windows into a BFD.
Copyright (C) 1995-2022 Free Software Foundation, Inc.
Written by Cygnus Support.
This file is part of BFD, the Binary File Descriptor library.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
MA 02110-1301, USA. */
#include "sysdep.h"
#include "bfd.h"
#include "libbfd.h"
/* Currently, if USE_MMAP is undefined, none of the window stuff is
used. Enabled by --with-mmap. */
#ifdef USE_MMAP
#undef HAVE_MPROTECT /* code's not tested yet */
#if HAVE_MMAP || HAVE_MPROTECT || HAVE_MADVISE
#include <sys/mman.h>
#endif
#ifndef MAP_FILE
#define MAP_FILE 0
#endif
static int debug_windows;
/* The idea behind the next and refcount fields is that one mapped
region can suffice for multiple read-only windows or multiple
non-overlapping read-write windows. It's not implemented yet
though. */
/*
INTERNAL_DEFINITION
.struct _bfd_window_internal {
. struct _bfd_window_internal *next;
. void *data;
. bfd_size_type size;
. int refcount : 31; {* should be enough... *}
. unsigned mapped : 1; {* 1 = mmap, 0 = malloc *}
.};
*/
void
bfd_init_window (bfd_window *windowp)
{
windowp->data = 0;
windowp->i = 0;
windowp->size = 0;
}
void
bfd_free_window (bfd_window *windowp)
{
bfd_window_internal *i = windowp->i;
windowp->i = 0;
windowp->data = 0;
if (i == 0)
return;
i->refcount--;
if (debug_windows)
fprintf (stderr, "freeing window @%p<%p,%lx,%p>\n",
windowp, windowp->data, (unsigned long) windowp->size, windowp->i);
if (i->refcount != 0)
return;
if (i->mapped)
{
#ifdef HAVE_MMAP
munmap (i->data, i->size);
goto no_free;
#else
abort ();
#endif
}
#ifdef HAVE_MPROTECT
mprotect (i->data, i->size, PROT_READ | PROT_WRITE);
#endif
free (i->data);
#ifdef HAVE_MMAP
no_free:
#endif
i->data = 0;
/* There should be no more references to i at this point. */
free (i);
}
static int ok_to_map = 1;
bool
bfd_get_file_window (bfd *abfd,
file_ptr offset,
bfd_size_type size,
bfd_window *windowp,
bool writable)
{
static size_t pagesize;
bfd_window_internal *i = windowp->i;
bfd_size_type size_to_alloc = size;
if (debug_windows)
fprintf (stderr, "bfd_get_file_window (%p, %6ld, %6ld, %p<%p,%lx,%p>, %d)",
abfd, (long) offset, (long) size,
windowp, windowp->data, (unsigned long) windowp->size,
windowp->i, writable);
/* Make sure we know the page size, so we can be friendly to mmap. */
if (pagesize == 0)
pagesize = getpagesize ();
if (pagesize == 0)
abort ();
if (i == NULL)
{
i = bfd_zmalloc (sizeof (bfd_window_internal));
if (i == NULL)
return false;
i->data = NULL;
}
#ifdef HAVE_MMAP
if (ok_to_map
&& (i->data == NULL || i->mapped == 1)
&& (abfd->flags & BFD_IN_MEMORY) == 0)
{
file_ptr file_offset, offset2;
size_t real_size;
int fd;
/* Find the real file and the real offset into it. */
while (abfd->my_archive != NULL
&& !bfd_is_thin_archive (abfd->my_archive))
{
offset += abfd->origin;
abfd = abfd->my_archive;
}
offset += abfd->origin;
/* Seek into the file, to ensure it is open if cacheable. */
if (abfd->iostream == NULL
&& (abfd->iovec == NULL
|| abfd->iovec->bseek (abfd, offset, SEEK_SET) != 0))
goto free_and_fail;
fd = fileno ((FILE *) abfd->iostream);
/* Compute offsets and size for mmap and for the user's data. */
offset2 = offset % pagesize;
if (offset2 < 0)
abort ();
file_offset = offset - offset2;
real_size = offset + size - file_offset;
real_size = real_size + pagesize - 1;
real_size -= real_size % pagesize;
/* If we're re-using a memory region, make sure it's big enough. */
if (i->data != NULL && i->size < size)
{
munmap (i->data, i->size);
i->data = NULL;
}
i->data = mmap (i->data, real_size,
writable ? PROT_WRITE | PROT_READ : PROT_READ,
(writable
? MAP_FILE | MAP_PRIVATE
: MAP_FILE | MAP_SHARED),
fd, file_offset);
if (i->data == (void *) -1)
{
/* An error happened. Report it, or try using malloc, or
something. */
bfd_set_error (bfd_error_system_call);
windowp->data = 0;
if (debug_windows)
fprintf (stderr, "\t\tmmap failed!\n");
goto free_and_fail;
}
if (debug_windows)
fprintf (stderr, "\n\tmapped %ld at %p, offset is %ld\n",
(long) real_size, i->data, (long) offset2);
i->size = real_size;
windowp->data = (bfd_byte *) i->data + offset2;
windowp->size = size;
i->mapped = 1;
i->refcount = 1;
windowp->i = i;
return true;
}
else if (debug_windows)
{
if (ok_to_map)
fprintf (stderr, _("not mapping: data=%lx mapped=%d\n"),
(unsigned long) i->data, (int) i->mapped);
else
fprintf (stderr, _("not mapping: env var not set\n"));
}
#else
ok_to_map = 0;
#endif
#ifdef HAVE_MPROTECT
if (!writable)
{
size_to_alloc += pagesize - 1;
size_to_alloc -= size_to_alloc % pagesize;
}
#endif
if (debug_windows)
fprintf (stderr, "\n\t%s(%6ld)",
i->data ? "realloc" : " malloc", (long) size_to_alloc);
i->data = bfd_realloc_or_free (i->data, size_to_alloc);
if (debug_windows)
fprintf (stderr, "\t-> %p\n", i->data);
if (i->data == NULL)
{
if (size_to_alloc == 0)
{
windowp->i = i;
return true;
}
goto free_and_fail;
}
i->refcount = 1;
if (bfd_seek (abfd, offset, SEEK_SET) != 0)
goto free_and_fail;
i->size = bfd_bread (i->data, size, abfd);
if (i->size != size)
goto free_and_fail;
i->mapped = 0;
#ifdef HAVE_MPROTECT
if (!writable)
{
if (debug_windows)
fprintf (stderr, "\tmprotect (%p, %ld, PROT_READ)\n", i->data,
(long) i->size);
mprotect (i->data, i->size, PROT_READ);
}
#endif
windowp->data = i->data;
windowp->size = i->size;
windowp->i = i;
return true;
free_and_fail:
/* We have a bfd_window_internal, but an error occurred. Free it. */
free (i);
return false;
}
#endif /* USE_MMAP */
|
