1 /* Support for dynamic linking code in static libc.
2 Copyright (C) 1996-2002, 2003, 2004 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 ElfW(Addr
) _dl_use_load_bias
= -2;
47 /* If nonzero print warnings about problematic situations. */
50 /* We never do profiling. */
51 const char *_dl_profile
;
52 const char *_dl_profile_output
;
54 /* Names of shared object for which the RUNPATHs and RPATHs should be
56 const char *_dl_inhibit_rpath
;
58 /* The map for the object we will profile. */
59 struct link_map
*_dl_profile_map
;
61 /* This is the address of the last stack address ever used. */
62 void *__libc_stack_end
;
64 /* Path where the binary is found. */
65 const char *_dl_origin_path
;
67 /* Nonzero if runtime lookup should not update the .got/.plt. */
70 /* Namespace information. */
71 struct link_namespaces _dl_ns
[DL_NNS
];
73 /* Incremented whenever something may have been added to dl_loaded. */
74 unsigned long long _dl_load_adds
;
76 /* Fake scope. In dynamically linked binaries this is the scope of the
77 main application but here we don't have something like this. So
78 create a fake scope containing nothing. */
79 struct r_scope_elem _dl_initial_searchlist
;
81 #ifndef HAVE_INLINED_SYSCALLS
82 /* Nonzero during startup. */
83 int _dl_starting_up
= 1;
86 /* Get architecture specific initializer. */
87 #include <dl-procinfo.c>
89 /* We expect less than a second for relocation. */
90 #ifdef HP_SMALL_TIMING_AVAIL
91 # undef HP_TIMING_AVAIL
92 # define HP_TIMING_AVAIL HP_SMALL_TIMING_AVAIL
95 /* Initial value of the CPU clock. */
96 #ifndef HP_TIMING_NONAVAIL
97 hp_timing_t _dl_cpuclock_offset
;
101 void (*_dl_init_static_tls
) (struct link_map
*) = &_dl_nothread_init_static_tls
;
106 unsigned int _dl_osversion
;
108 /* All known directories in sorted order. */
109 struct r_search_path_elem
*_dl_all_dirs
;
111 /* All directories after startup. */
112 struct r_search_path_elem
*_dl_init_all_dirs
;
114 /* The object to be initialized first. */
115 struct link_map
*_dl_initfirst
;
117 /* Descriptor to write debug messages to. */
118 int _dl_debug_fd
= STDERR_FILENO
;
120 int _dl_correct_cache_id
= _DL_CACHE_DEFAULT_ID
;
122 ElfW(Phdr
) *_dl_phdr
;
124 unsigned long int _dl_hwcap
__attribute__ ((nocommon
));
126 /* Prevailing state of the stack, PF_X indicating it's executable. */
127 ElfW(Word
) _dl_stack_flags
= PF_R
|PF_W
|PF_X
;
129 /* If loading a shared object requires that we make the stack executable
130 when it was not, we do it by calling this function.
131 It returns an errno code or zero on success. */
132 int (*_dl_make_stack_executable_hook
) (void **) internal_function
133 = _dl_make_stack_executable
;
136 #ifdef NEED_DL_SYSINFO
137 /* Needed for improved syscall handling on at least x86/Linux. */
138 uintptr_t _dl_sysinfo
= DL_SYSINFO_DEFAULT
;
139 /* Address of the ELF headers in the vsyscall page. */
140 const ElfW(Ehdr
) *_dl_sysinfo_dso
;
143 /* During the program run we must not modify the global data of
144 loaded shared object simultanously in two threads. Therefore we
145 protect `_dl_open' and `_dl_close' in dl-close.c.
147 This must be a recursive lock since the initializer function of
148 the loaded object might as well require a call to this function.
149 At this time it is not anymore a problem to modify the tables. */
150 __rtld_lock_define_initialized_recursive (, _dl_load_lock
)
153 #ifdef HAVE_AUX_VECTOR
158 _dl_aux_init (ElfW(auxv_t
) *av
)
164 for (; av
->a_type
!= AT_NULL
; ++av
)
168 GLRO(dl_pagesize
) = av
->a_un
.a_val
;
171 GLRO(dl_clktck
) = av
->a_un
.a_val
;
174 GL(dl_phdr
) = av
->a_un
.a_ptr
;
177 GL(dl_phnum
) = av
->a_un
.a_val
;
180 GLRO(dl_hwcap
) = av
->a_un
.a_val
;
182 #ifdef NEED_DL_SYSINFO
184 GL(dl_sysinfo
) = av
->a_un
.a_val
;
188 uid
^= av
->a_un
.a_val
;
192 uid
^= av
->a_un
.a_val
;
196 gid
^= av
->a_un
.a_val
;
200 gid
^= av
->a_un
.a_val
;
205 __libc_enable_secure
= av
->a_un
.a_val
;
206 __libc_enable_secure_decided
= 1;
211 __libc_enable_secure
= uid
!= 0 || gid
!= 0;
212 __libc_enable_secure_decided
= 1;
220 _dl_non_dynamic_init (void)
223 HP_TIMING_NOW (_dl_cpuclock_offset
);
226 _dl_pagesize
= __getpagesize ();
228 _dl_verbose
= *(getenv ("LD_WARN") ?: "") == '\0' ? 0 : 1;
230 /* Initialize the data structures for the search paths for shared
232 _dl_init_paths (getenv ("LD_LIBRARY_PATH"));
234 _dl_lazy
= *(getenv ("LD_BIND_NOW") ?: "") == '\0';
236 _dl_bind_not
= *(getenv ("LD_BIND_NOT") ?: "") != '\0';
238 _dl_dynamic_weak
= *(getenv ("LD_DYNAMIC_WEAK") ?: "") == '\0';
240 _dl_profile_output
= getenv ("LD_PROFILE_OUTPUT");
241 if (_dl_profile_output
== NULL
|| _dl_profile_output
[0] == '\0')
243 = &"/var/tmp\0/var/profile"[__libc_enable_secure
? 9 : 0];
245 if (__libc_enable_secure
)
247 static const char unsecure_envvars
[] =
249 #ifdef EXTRA_UNSECURE_ENVVARS
250 EXTRA_UNSECURE_ENVVARS
253 const char *cp
= unsecure_envvars
;
255 while (cp
< unsecure_envvars
+ sizeof (unsecure_envvars
))
258 cp
= (const char *) __rawmemchr (cp
, '\0') + 1;
261 if (__access ("/etc/suid-debug", F_OK
) != 0)
262 __unsetenv ("MALLOC_CHECK_");
265 #ifdef DL_PLATFORM_INIT
269 #ifdef DL_OSVERSION_INIT
273 /* Now determine the length of the platform string. */
274 if (_dl_platform
!= NULL
)
275 _dl_platformlen
= strlen (_dl_platform
);
277 #if defined (__i386__) && !defined (USE_TLS)
278 /* Load libs not using TLS. */
279 _dl_osversion
= 0x20205;
282 /* Scan for a program header telling us the stack is nonexecutable. */
283 if (_dl_phdr
!= NULL
)
284 for (uint_fast16_t i
= 0; i
< _dl_phnum
; ++i
)
285 if (_dl_phdr
[i
].p_type
== PT_GNU_STACK
)
287 _dl_stack_flags
= _dl_phdr
[i
].p_flags
;
293 const struct r_strlenpair
*
295 _dl_important_hwcaps (const char *platform
, size_t platform_len
, size_t *sz
,
296 size_t *max_capstrlen
)
298 static struct r_strlenpair result
;
301 result
.str
= buf
; /* Does not really matter. */
309 #ifdef DL_SYSINFO_IMPLEMENTATION
310 DL_SYSINFO_IMPLEMENTATION