1 /* Support for dynamic linking code in static libc.
2 Copyright (C) 1996-2001, 2002 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, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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>
31 #include <dl-librecon.h>
32 #include <unsecvars.h>
33 #include <hp-timing.h>
35 extern char *__progname;
36 char **_dl_argv = &__progname; /* This is checked for some error messages. */
38 /* Name of the architecture. */
39 const char *_dl_platform;
40 size_t _dl_platformlen;
44 /* XXX I know about at least one case where we depend on the old weak
45 behavior (it has to do with librt). Until we get DSO groups implemented
46 we have to make this the default. Bummer. --drepper */
50 int _dl_dynamic_weak = 1;
53 /* If nonzero print warnings about problematic situations. */
56 /* We never do profiling. */
57 const char *_dl_profile;
59 /* Names of shared object for which the RUNPATHs and RPATHs should be
61 const char *_dl_inhibit_rpath;
63 /* The map for the object we will profile. */
64 struct link_map *_dl_profile_map;
66 /* This is the address of the last stack address ever used. */
67 void *__libc_stack_end;
69 /* Path where the binary is found. */
70 const char *_dl_origin_path;
72 /* Nonzero if runtime lookup should not update the .got/.plt. */
75 /* Initially empty list of loaded objects. */
76 struct link_map *_dl_loaded;
77 /* Number of object in the _dl_loaded list. */
78 unsigned int _dl_nloaded;
80 /* Fake scope. In dynamically linked binaries this is the scope of the
81 main application but here we don't have something like this. So
82 create a fake scope containing nothing. */
83 struct r_scope_elem _dl_initial_searchlist;
84 /* Variable which can be used in lookup to process the global scope. */
85 struct r_scope_elem *_dl_global_scope[2] = { &_dl_initial_searchlist, NULL };
86 /* This is a global pointer to this structure which is public. It is
87 used by dlopen/dlclose to add and remove objects from what is regarded
88 to be the global scope. */
89 struct r_scope_elem *_dl_main_searchlist = &_dl_initial_searchlist;
91 /* Nonzero during startup. */
92 int _dl_starting_up = 1;
94 /* Get architecture specific initializer. */
95 #include <dl-procinfo.c>
97 /* We expect less than a second for relocation. */
98 #ifdef HP_SMALL_TIMING_AVAIL
99 # undef HP_TIMING_AVAIL
100 # define HP_TIMING_AVAIL HP_SMALL_TIMING_AVAIL
103 /* Initial value of the CPU clock. */
104 #ifndef HP_TIMING_NONAVAIL
105 hp_timing_t _dl_cpuclock_offset;
108 /* This is zero at program start to signal that the global scope map is
109 allocated by rtld. Later it keeps the size of the map. It might be
110 reset if in _dl_close if the last global object is removed. */
111 size_t _dl_global_scope_alloc;
115 unsigned int _dl_osversion;
117 /* All known directories in sorted order. */
118 struct r_search_path_elem *_dl_all_dirs;
120 /* All directories after startup. */
121 struct r_search_path_elem *_dl_init_all_dirs;
123 /* The object to be initialized first. */
124 struct link_map *_dl_initfirst;
126 /* Descriptor to write debug messages to. */
127 int _dl_debug_fd = STDERR_FILENO;
129 int _dl_correct_cache_id = _DL_CACHE_DEFAULT_ID;
131 struct ElfW(Phdr) *_dl_phdr;
134 #ifdef NEED_DL_SYSINFO
135 /* Needed for improved syscall handling on at least x86/Linux. */
136 uintptr_t _dl_sysinfo = DL_SYSINFO_DEFAULT;
139 /* During the program run we must not modify the global data of
140 loaded shared object simultanously in two threads. Therefore we
141 protect `_dl_open' and `_dl_close' in dl-close.c.
143 This must be a recursive lock since the initializer function of
144 the loaded object might as well require a call to this function.
145 At this time it is not anymore a problem to modify the tables. */
146 __rtld_lock_define_initialized_recursive (, _dl_load_lock)
149 #ifdef HAVE_AUX_VECTOR
154 _dl_aux_init (ElfW(auxv_t) *av)
156 for (; av->a_type != AT_NULL; ++av)
160 GL(dl_pagesize) = av->a_un.a_val;
163 GL(dl_clktck) = av->a_un.a_val;
166 GL(dl_phdr) = av->a_un.a_ptr;
169 GL(dl_phnum) = av->a_un.a_val;
178 _dl_non_dynamic_init (void)
181 HP_TIMING_NOW (_dl_cpuclock_offset);
184 _dl_pagesize = __getpagesize ();
186 _dl_verbose = *(getenv ("LD_WARN") ?: "") == '\0' ? 0 : 1;
188 /* Initialize the data structures for the search paths for shared
190 _dl_init_paths (getenv ("LD_LIBRARY_PATH"));
192 _dl_lazy = *(getenv ("LD_BIND_NOW") ?: "") == '\0';
194 _dl_bind_not = *(getenv ("LD_BIND_NOT") ?: "") != '\0';
196 _dl_dynamic_weak = *(getenv ("LD_DYNAMIC_WEAK") ?: "") == '\0';
198 if (__libc_enable_secure)
200 static const char *unsecure_envvars[] =
203 #ifdef EXTRA_UNSECURE_ENVVARS
204 EXTRA_UNSECURE_ENVVARS
210 cnt < sizeof (unsecure_envvars) / sizeof (unsecure_envvars[0]);
212 unsetenv (unsecure_envvars[cnt]);
214 if (__access ("/etc/suid-debug", F_OK) != 0)
215 unsetenv ("MALLOC_CHECK_");
218 #ifdef DL_PLATFORM_INIT
222 #ifdef DL_OSVERSION_INIT
226 /* Now determine the length of the platform string. */
227 if (_dl_platform != NULL)
228 _dl_platformlen = strlen (_dl_platform);
232 const struct r_strlenpair *
234 _dl_important_hwcaps (const char *platform, size_t platform_len, size_t *sz,
235 size_t *max_capstrlen)
237 static struct r_strlenpair result;
240 result.str = buf; /* Does not really matter. */
248 #ifdef DL_SYSINFO_IMPLEMENTATION
249 DL_SYSINFO_IMPLEMENTATION