1 /* Support for dynamic linking code in static libc.
2 Copyright (C) 1996-2002, 2003, 2004, 2005 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 uint64_t _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
;
140 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
141 /* Address of the ELF headers in the vsyscall page. */
142 const ElfW(Ehdr
) *_dl_sysinfo_dso
;
145 /* During the program run we must not modify the global data of
146 loaded shared object simultanously in two threads. Therefore we
147 protect `_dl_open' and `_dl_close' in dl-close.c.
149 This must be a recursive lock since the initializer function of
150 the loaded object might as well require a call to this function.
151 At this time it is not anymore a problem to modify the tables. */
152 __rtld_lock_define_initialized_recursive (, _dl_load_lock
)
155 #ifdef HAVE_AUX_VECTOR
160 _dl_aux_init (ElfW(auxv_t
) *av
)
166 for (; av
->a_type
!= AT_NULL
; ++av
)
170 GLRO(dl_pagesize
) = av
->a_un
.a_val
;
173 GLRO(dl_clktck
) = av
->a_un
.a_val
;
176 GL(dl_phdr
) = av
->a_un
.a_ptr
;
179 GL(dl_phnum
) = av
->a_un
.a_val
;
182 GLRO(dl_hwcap
) = (unsigned long int) av
->a_un
.a_val
;
184 #ifdef NEED_DL_SYSINFO
186 GL(dl_sysinfo
) = av
->a_un
.a_val
;
189 #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
190 case AT_SYSINFO_EHDR
:
191 GL(dl_sysinfo_dso
) = av
->a_un
.a_ptr
;
195 uid
^= av
->a_un
.a_val
;
199 uid
^= av
->a_un
.a_val
;
203 gid
^= av
->a_un
.a_val
;
207 gid
^= av
->a_un
.a_val
;
212 __libc_enable_secure
= av
->a_un
.a_val
;
213 __libc_enable_secure_decided
= 1;
218 __libc_enable_secure
= uid
!= 0 || gid
!= 0;
219 __libc_enable_secure_decided
= 1;
227 _dl_non_dynamic_init (void)
230 HP_TIMING_NOW (_dl_cpuclock_offset
);
233 _dl_pagesize
= __getpagesize ();
235 _dl_verbose
= *(getenv ("LD_WARN") ?: "") == '\0' ? 0 : 1;
237 /* Initialize the data structures for the search paths for shared
239 _dl_init_paths (getenv ("LD_LIBRARY_PATH"));
241 _dl_lazy
= *(getenv ("LD_BIND_NOW") ?: "") == '\0';
243 _dl_bind_not
= *(getenv ("LD_BIND_NOT") ?: "") != '\0';
245 _dl_dynamic_weak
= *(getenv ("LD_DYNAMIC_WEAK") ?: "") == '\0';
247 _dl_profile_output
= getenv ("LD_PROFILE_OUTPUT");
248 if (_dl_profile_output
== NULL
|| _dl_profile_output
[0] == '\0')
250 = &"/var/tmp\0/var/profile"[__libc_enable_secure
? 9 : 0];
252 if (__libc_enable_secure
)
254 static const char unsecure_envvars
[] =
256 #ifdef EXTRA_UNSECURE_ENVVARS
257 EXTRA_UNSECURE_ENVVARS
260 const char *cp
= unsecure_envvars
;
262 while (cp
< unsecure_envvars
+ sizeof (unsecure_envvars
))
265 cp
= (const char *) __rawmemchr (cp
, '\0') + 1;
268 if (__access ("/etc/suid-debug", F_OK
) != 0)
269 __unsetenv ("MALLOC_CHECK_");
272 #ifdef DL_PLATFORM_INIT
276 #ifdef DL_OSVERSION_INIT
280 /* Now determine the length of the platform string. */
281 if (_dl_platform
!= NULL
)
282 _dl_platformlen
= strlen (_dl_platform
);
284 #if defined (__i386__) && !defined (USE_TLS)
285 /* Load libs not using TLS. */
286 _dl_osversion
= 0x20205;
289 /* Scan for a program header telling us the stack is nonexecutable. */
290 if (_dl_phdr
!= NULL
)
291 for (uint_fast16_t i
= 0; i
< _dl_phnum
; ++i
)
292 if (_dl_phdr
[i
].p_type
== PT_GNU_STACK
)
294 _dl_stack_flags
= _dl_phdr
[i
].p_flags
;
300 const struct r_strlenpair
*
302 _dl_important_hwcaps (const char *platform
, size_t platform_len
, size_t *sz
,
303 size_t *max_capstrlen
)
305 static struct r_strlenpair result
;
308 result
.str
= buf
; /* Does not really matter. */
316 #ifdef DL_SYSINFO_IMPLEMENTATION
317 DL_SYSINFO_IMPLEMENTATION