1 /* Storage management for the chain of loaded shared objects.
2 Copyright (C) 1995-2017 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
28 /* Add the new link_map NEW to the end of the namespace list. */
30 _dl_add_to_namespace_list (struct link_map
*new, Lmid_t nsid
)
32 /* We modify the list of loaded objects. */
33 __rtld_lock_lock_recursive (GL(dl_load_write_lock
));
35 if (GL(dl_ns
)[nsid
]._ns_loaded
!= NULL
)
37 struct link_map
*l
= GL(dl_ns
)[nsid
]._ns_loaded
;
38 while (l
->l_next
!= NULL
)
41 /* new->l_next = NULL; Would be necessary but we use calloc. */
45 GL(dl_ns
)[nsid
]._ns_loaded
= new;
46 ++GL(dl_ns
)[nsid
]._ns_nloaded
;
47 new->l_serial
= GL(dl_load_adds
);
50 __rtld_lock_unlock_recursive (GL(dl_load_write_lock
));
54 /* Allocate a `struct link_map' for a new object being loaded,
55 and enter it into the _dl_loaded list. */
57 _dl_new_object (char *realname
, const char *libname
, int type
,
58 struct link_map
*loader
, int mode
, Lmid_t nsid
)
60 size_t libname_len
= strlen (libname
) + 1;
62 struct libname_list
*newname
;
64 /* We create the map for the executable before we know whether we have
65 auditing libraries and if yes, how many. Assume the worst. */
66 unsigned int naudit
= GLRO(dl_naudit
) ?: ((mode
& __RTLD_OPENEXEC
)
68 size_t audit_space
= naudit
* sizeof (new->l_audit
[0]);
70 # define audit_space 0
73 new = (struct link_map
*) calloc (sizeof (*new) + audit_space
74 + sizeof (struct link_map
*)
75 + sizeof (*newname
) + libname_len
, 1);
80 new->l_symbolic_searchlist
.r_list
= (struct link_map
**) ((char *) (new + 1)
83 new->l_libname
= newname
84 = (struct libname_list
*) (new->l_symbolic_searchlist
.r_list
+ 1);
85 newname
->name
= (char *) memcpy (newname
+ 1, libname
, libname_len
);
86 /* newname->next = NULL; We use calloc therefore not necessary. */
87 newname
->dont_free
= 1;
89 /* When we create the executable link map, or a VDSO link map, we start
90 with "" for the l_name. In these cases "" points to ld.so rodata
91 and won't get dumped during core file generation. Therefore to assist
92 gdb and to create more self-contained core files we adjust l_name to
93 point at the newly allocated copy (which will get dumped) instead of
94 the ld.so rodata copy. */
95 new->l_name
= *realname
? realname
: (char *) newname
->name
+ libname_len
- 1;
97 /* If we set the bit now since we know it is never used we avoid
98 dirtying the cache line later. */
99 if ((GLRO(dl_debug_mask
) & DL_DEBUG_UNUSED
) == 0)
101 new->l_loader
= loader
;
102 #if NO_TLS_OFFSET != 0
103 new->l_tls_offset
= NO_TLS_OFFSET
;
108 for (unsigned int cnt
= 0; cnt
< naudit
; ++cnt
)
110 new->l_audit
[cnt
].cookie
= (uintptr_t) new;
111 /* new->l_audit[cnt].bindflags = 0; */
115 /* new->l_global = 0; We use calloc therefore not necessary. */
117 /* Use the 'l_scope_mem' array by default for the 'l_scope'
118 information. If we need more entries we will allocate a large
119 array dynamically. */
120 new->l_scope
= new->l_scope_mem
;
121 new->l_scope_max
= sizeof (new->l_scope_mem
) / sizeof (new->l_scope_mem
[0]);
123 /* Counter for the scopes we have to handle. */
126 if (GL(dl_ns
)[nsid
]._ns_loaded
!= NULL
)
127 /* Add the global scope. */
128 new->l_scope
[idx
++] = &GL(dl_ns
)[nsid
]._ns_loaded
->l_searchlist
;
130 /* If we have no loader the new object acts as it. */
134 /* Determine the local scope. */
135 while (loader
->l_loader
!= NULL
)
136 loader
= loader
->l_loader
;
138 /* Insert the scope if it isn't the global scope we already added. */
139 if (idx
== 0 || &loader
->l_searchlist
!= new->l_scope
[0])
141 if ((mode
& RTLD_DEEPBIND
) != 0 && idx
!= 0)
143 new->l_scope
[1] = new->l_scope
[0];
147 new->l_scope
[idx
] = &loader
->l_searchlist
;
150 new->l_local_scope
[0] = &new->l_searchlist
;
152 /* Don't try to find the origin for the main map which has the name "". */
153 if (realname
[0] != '\0')
155 size_t realname_len
= strlen (realname
) + 1;
159 if (realname
[0] == '/')
161 /* It is an absolute path. Use it. But we have to make a
162 copy since we strip out the trailing slash. */
163 cp
= origin
= (char *) malloc (realname_len
);
166 origin
= (char *) -1;
172 size_t len
= realname_len
;
175 /* Get the current directory name. */
182 new_origin
= (char *) realloc (origin
, len
);
183 if (new_origin
== NULL
)
184 /* We exit the loop. Note that result == NULL. */
188 while ((result
= __getcwd (origin
, len
- realname_len
)) == NULL
193 /* We were not able to determine the current directory.
194 Note that free(origin) is OK if origin == NULL. */
196 origin
= (char *) -1;
200 /* Find the end of the path and see whether we have to add a
201 slash. We could use rawmemchr but this need not be
203 cp
= (strchr
) (origin
, '\0');
208 /* Add the real file name. */
209 cp
= __mempcpy (cp
, realname
, realname_len
);
211 /* Now remove the filename and the slash. Leave the slash if
212 the name is something like "/foo". */
218 /* Keep the only slash which is the first character. */
223 new->l_origin
= origin
;