1 /* Support for dynamic linking code in static libc.
2 Copyright (C) 1996, 97, 98, 99, 2000, 2001 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 Library General Public License as
7 published by the Free Software Foundation; either version 2 of the
8 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 Library General Public License for more details.
15 You should have received a copy of the GNU Library General Public
16 License along with the GNU C Library; see the file COPYING.LIB. If not,
17 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA. */
20 /* This file defines some things that for the dynamic linker are defined in
21 rtld.c and dl-sysdep.c in ways appropriate to bootstrap dynamic linking. */
28 #include <dl-machine.h>
29 #include <bits/libc-lock.h>
30 #include <dl-librecon.h>
31 #include <unsecvars.h>
33 extern char *__progname;
34 char **_dl_argv = &__progname; /* This is checked for some error messages. */
36 /* Name of the architecture. */
37 const char *_dl_platform;
38 size_t _dl_platformlen;
41 int _dl_debug_impcalls;
42 int _dl_debug_bindings;
43 int _dl_debug_symbols;
44 int _dl_debug_versions;
48 /* XXX I know about at least one case where we depend on the old weak
49 behavior (it has to do with librt). Until we get DSO groups implemented
50 we have to make this the default. Bummer. --drepper */
54 int _dl_dynamic_weak = 1;
57 /* If nonzero print warnings about problematic situations. */
60 /* Structure to store information about search paths. */
61 struct r_search_path *_dl_search_paths;
63 /* We never do profiling. */
64 const char *_dl_profile;
66 /* Names of shared object for which the RUNPATHs and RPATHs should be
68 const char *_dl_inhibit_rpath;
70 /* The map for the object we will profile. */
71 struct link_map *_dl_profile_map;
73 /* This is the address of the last stack address ever used. */
74 void *__libc_stack_end;
76 /* Path where the binary is found. */
77 const char *_dl_origin_path;
79 /* Nonzero if runtime lookup should not update the .got/.plt. */
82 /* Initially empty list of loaded objects. */
83 struct link_map *_dl_loaded;
84 /* Number of object in the _dl_loaded list. */
85 unsigned int _dl_nloaded;
87 /* Fake scope. In dynamically linked binaries this is the scope of the
88 main application but here we don't have something like this. So
89 create a fake scope containing nothing. */
90 struct r_scope_elem _dl_initial_searchlist;
91 /* Variable which can be used in lookup to process the global scope. */
92 struct r_scope_elem *_dl_global_scope[2] = { &_dl_initial_searchlist, NULL };
93 /* This is a global pointer to this structure which is public. It is
94 used by dlopen/dlclose to add and remove objects from what is regarded
95 to be the global scope. */
96 struct r_scope_elem *_dl_main_searchlist = &_dl_initial_searchlist;
98 /* Nonzero during startup. */
99 int _dl_starting_up = 1;
101 /* During the program run we must not modify the global data of
102 loaded shared object simultanously in two threads. Therefore we
103 protect `_dl_open' and `_dl_close' in dl-close.c.
105 This must be a recursive lock since the initializer function of
106 the loaded object might as well require a call to this function.
107 At this time it is not anymore a problem to modify the tables. */
108 __libc_lock_define_initialized_recursive (, _dl_load_lock)
111 # define DL_FIND_AUXV(auxp, envp) \
114 for (_tmp = (void **) (envp); *_tmp; ++_tmp) \
116 (auxp) = (void *) ++_tmp; \
120 extern int _dl_clktck;
122 static void non_dynamic_init (int argc, char **argv, char **envp)
123 __attribute__ ((unused));
126 non_dynamic_init (int argc, char **argv, char **envp)
130 DL_FIND_AUXV (av, envp);
132 for (; av->a_type != AT_NULL; ++av)
136 _dl_pagesize = av->a_un.a_val;
139 _dl_platform = av->a_un.a_ptr;
142 _dl_clktck = av->a_un.a_val;
147 _dl_pagesize = __getpagesize ();
149 _dl_verbose = *(getenv ("LD_WARN") ?: "") == '\0' ? 0 : 1;
151 /* Initialize the data structures for the search paths for shared
153 _dl_init_paths (getenv ("LD_LIBRARY_PATH"));
155 _dl_lazy = *(getenv ("LD_BIND_NOW") ?: "") == '\0';
157 _dl_bind_not = *(getenv ("LD_BIND_NOT") ?: "") != '\0';
159 _dl_dynamic_weak = *(getenv ("LD_DYNAMIC_WEAK") ?: "") == '\0';
161 if (__libc_enable_secure)
163 static const char *unsecure_envvars[] =
166 #ifdef EXTRA_UNSECURE_ENVVARS
167 EXTRA_UNSECURE_ENVVARS
173 cnt < sizeof (unsecure_envvars) / sizeof (unsecure_envvars[0]);
175 unsetenv (unsecure_envvars[cnt]);
177 if (__access ("/etc/suid-debug", F_OK) != 0)
178 unsetenv ("MALLOC_CHECK_");
181 #ifdef DL_PLATFORM_INIT
185 /* Now determine the length of the platform string. */
186 if (_dl_platform != NULL)
187 _dl_platformlen = strlen (_dl_platform);
189 text_set_element (__libc_subinit, non_dynamic_init);
191 const struct r_strlenpair *
193 _dl_important_hwcaps (const char *platform, size_t platform_len, size_t *sz,
194 size_t *max_capstrlen)
196 struct r_strlenpair *result;
198 /* XXX We don't try to find the capabilities in this case. */
199 result = (struct r_strlenpair *) malloc (sizeof (*result));
201 _dl_signal_error (ENOMEM, NULL, N_("cannot create capability list"));
203 result[0].str = (char *) result; /* Does not really matter. */