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
|
/* Storage management for the chain of loaded shared objects.
Copyright (C) 1995-2016 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 <errno.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <ldsodefs.h>
#include <assert.h>
/* Add the new link_map NEW to the end of the namespace list. */
void
internal_function
_dl_add_to_namespace_list (struct link_map *new, Lmid_t nsid)
{
/* We modify the list of loaded objects. */
__rtld_lock_lock_recursive (GL(dl_load_write_lock));
if (GL(dl_ns)[nsid]._ns_loaded != NULL)
{
struct link_map *l = GL(dl_ns)[nsid]._ns_loaded;
while (l->l_next != NULL)
l = l->l_next;
new->l_prev = l;
/* new->l_next = NULL; Would be necessary but we use calloc. */
l->l_next = new;
}
else
GL(dl_ns)[nsid]._ns_loaded = new;
++GL(dl_ns)[nsid]._ns_nloaded;
new->l_serial = GL(dl_load_adds);
++GL(dl_load_adds);
__rtld_lock_unlock_recursive (GL(dl_load_write_lock));
}
/* Allocate a `struct link_map' for a new object being loaded,
and enter it into the _dl_loaded list. */
struct link_map *
internal_function
_dl_new_object (char *realname, const char *libname, int type,
struct link_map *loader, int mode, Lmid_t nsid)
{
size_t libname_len = strlen (libname) + 1;
struct link_map *new;
struct libname_list *newname;
#ifdef SHARED
/* We create the map for the executable before we know whether we have
auditing libraries and if yes, how many. Assume the worst. */
unsigned int naudit = GLRO(dl_naudit) ?: ((mode & __RTLD_OPENEXEC)
? DL_NNS : 0);
size_t audit_space = naudit * sizeof (new->l_audit[0]);
#else
# define audit_space 0
#endif
new = (struct link_map *) calloc (sizeof (*new) + audit_space
+ sizeof (struct link_map *)
+ sizeof (*newname) + libname_len, 1);
if (new == NULL)
return NULL;
new->l_real = new;
new->l_symbolic_searchlist.r_list = (struct link_map **) ((char *) (new + 1)
+ audit_space);
new->l_libname = newname
= (struct libname_list *) (new->l_symbolic_searchlist.r_list + 1);
newname->name = (char *) memcpy (newname + 1, libname, libname_len);
/* newname->next = NULL; We use calloc therefore not necessary. */
newname->dont_free = 1;
/* When we create the executable link map, or a VDSO link map, we start
with "" for the l_name. In these cases "" points to ld.so rodata
and won't get dumped during core file generation. Therefore to assist
gdb and to create more self-contained core files we adjust l_name to
point at the newly allocated copy (which will get dumped) instead of
the ld.so rodata copy. */
new->l_name = *realname ? realname : (char *) newname->name + libname_len - 1;
new->l_type = type;
/* If we set the bit now since we know it is never used we avoid
dirtying the cache line later. */
if ((GLRO(dl_debug_mask) & DL_DEBUG_UNUSED) == 0)
new->l_used = 1;
new->l_loader = loader;
#if NO_TLS_OFFSET != 0
new->l_tls_offset = NO_TLS_OFFSET;
#endif
new->l_ns = nsid;
#ifdef SHARED
for (unsigned int cnt = 0; cnt < naudit; ++cnt)
{
new->l_audit[cnt].cookie = (uintptr_t) new;
/* new->l_audit[cnt].bindflags = 0; */
}
#endif
/* new->l_global = 0; We use calloc therefore not necessary. */
/* Use the 'l_scope_mem' array by default for the 'l_scope'
information. If we need more entries we will allocate a large
array dynamically. */
new->l_scope = new->l_scope_mem;
new->l_scope_max = sizeof (new->l_scope_mem) / sizeof (new->l_scope_mem[0]);
/* Counter for the scopes we have to handle. */
int idx = 0;
if (GL(dl_ns)[nsid]._ns_loaded != NULL)
/* Add the global scope. */
new->l_scope[idx++] = &GL(dl_ns)[nsid]._ns_loaded->l_searchlist;
/* If we have no loader the new object acts as it. */
if (loader == NULL)
loader = new;
else
/* Determine the local scope. */
while (loader->l_loader != NULL)
loader = loader->l_loader;
/* Insert the scope if it isn't the global scope we already added. */
if (idx == 0 || &loader->l_searchlist != new->l_scope[0])
{
if ((mode & RTLD_DEEPBIND) != 0 && idx != 0)
{
new->l_scope[1] = new->l_scope[0];
idx = 0;
}
new->l_scope[idx] = &loader->l_searchlist;
}
new->l_local_scope[0] = &new->l_searchlist;
/* Don't try to find the origin for the main map which has the name "". */
if (realname[0] != '\0')
{
size_t realname_len = strlen (realname) + 1;
char *origin;
char *cp;
if (realname[0] == '/')
{
/* It is an absolute path. Use it. But we have to make a
copy since we strip out the trailing slash. */
cp = origin = (char *) malloc (realname_len);
if (origin == NULL)
{
origin = (char *) -1;
goto out;
}
}
else
{
size_t len = realname_len;
char *result = NULL;
/* Get the current directory name. */
origin = NULL;
do
{
char *new_origin;
len += 128;
new_origin = (char *) realloc (origin, len);
if (new_origin == NULL)
/* We exit the loop. Note that result == NULL. */
break;
origin = new_origin;
}
while ((result = __getcwd (origin, len - realname_len)) == NULL
&& errno == ERANGE);
if (result == NULL)
{
/* We were not able to determine the current directory.
Note that free(origin) is OK if origin == NULL. */
free (origin);
origin = (char *) -1;
goto out;
}
/* Find the end of the path and see whether we have to add a
slash. We could use rawmemchr but this need not be
fast. */
cp = (strchr) (origin, '\0');
if (cp[-1] != '/')
*cp++ = '/';
}
/* Add the real file name. */
cp = __mempcpy (cp, realname, realname_len);
/* Now remove the filename and the slash. Leave the slash if
the name is something like "/foo". */
do
--cp;
while (*cp != '/');
if (cp == origin)
/* Keep the only slash which is the first character. */
++cp;
*cp = '\0';
out:
new->l_origin = origin;
}
return new;
}
|
