1 /* Copyright (C) 1998-2012 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <http://www.gnu.org/licenses/>. */
25 extern void __libc_init_first (int argc, char **argv, char **envp);
27 extern void __libc_csu_irel (void);
30 extern int __libc_multiple_libcs;
34 # include <dl-osinfo.h>
35 extern void __pthread_initialize_minimal (void);
36 # ifndef THREAD_SET_STACK_GUARD
37 /* Only exported for architectures that don't store the stack guard canary
38 in thread local area. */
39 uintptr_t __stack_chk_guard attribute_relro;
43 #ifdef HAVE_PTR_NTHREADS
44 /* We need atomic operations. */
53 # ifdef ELF_MACHINE_IRELA
54 # define IREL_T ElfW(Rela)
55 # define IPLT_START __rela_iplt_start
56 # define IPLT_END __rela_iplt_end
57 # define IREL elf_irela
58 # elif defined ELF_MACHINE_IREL
59 # define IREL_T ElfW(Rel)
60 # define IPLT_START __rel_iplt_start
61 # define IPLT_END __rel_iplt_end
62 # define IREL elf_irel
69 /* We use weak references for these so that we'll still work with a linker
70 that doesn't define them. Such a linker doesn't support IFUNC at all
71 and so uses won't work, but a statically-linked program that doesn't
72 use any IFUNC symbols won't have a problem. */
73 extern const IREL_T IPLT_START[] __attribute__ ((weak));
74 extern const IREL_T IPLT_END[] __attribute__ ((weak));
75 for (const IREL_T *ipltent = IPLT_START; ipltent < IPLT_END; ++ipltent)
82 #ifdef LIBC_START_MAIN
83 # ifdef LIBC_START_DISABLE_INLINE
84 # define STATIC static
86 # define STATIC static inline __attribute__ ((always_inline))
90 # define LIBC_START_MAIN BP_SYM (__libc_start_main)
93 #ifdef MAIN_AUXVEC_ARG
94 /* main gets passed a pointer to the auxiliary. */
95 # define MAIN_AUXVEC_DECL , void *
96 # define MAIN_AUXVEC_PARAM , auxvec
98 # define MAIN_AUXVEC_DECL
99 # define MAIN_AUXVEC_PARAM
102 STATIC int LIBC_START_MAIN (int (*main) (int, char **, char **
105 char *__unbounded *__unbounded ubp_av,
106 #ifdef LIBC_START_MAIN_AUXVEC_ARG
107 ElfW(auxv_t) *__unbounded auxvec,
109 __typeof (main) init,
111 void (*rtld_fini) (void),
112 void *__unbounded stack_end)
113 __attribute__ ((noreturn));
116 /* Note: the fini parameter is ignored here for shared library. It
117 is registered with __cxa_atexit. This had the disadvantage that
118 finalizers were called in more than one place. */
120 LIBC_START_MAIN (int (*main) (int, char **, char ** MAIN_AUXVEC_DECL),
121 int argc, char *__unbounded *__unbounded ubp_av,
122 #ifdef LIBC_START_MAIN_AUXVEC_ARG
123 ElfW(auxv_t) *__unbounded auxvec,
125 __typeof (main) init,
127 void (*rtld_fini) (void), void *__unbounded stack_end)
129 #if __BOUNDED_POINTERS__
135 /* Result of the 'main' function. */
138 __libc_multiple_libcs = &_dl_starting_up && !_dl_starting_up;
141 char *__unbounded *__unbounded ubp_ev = &ubp_av[argc + 1];
143 INIT_ARGV_and_ENVIRON;
145 /* Store the lowest stack address. This is done in ld.so if this is
146 the code for the DSO. */
147 __libc_stack_end = stack_end;
149 # ifdef HAVE_AUX_VECTOR
150 /* First process the auxiliary vector since we need to find the
151 program header to locate an eventually present PT_TLS entry. */
152 # ifndef LIBC_START_MAIN_AUXVEC_ARG
153 ElfW(auxv_t) *__unbounded auxvec;
155 char *__unbounded *__unbounded evp = ubp_ev;
156 while (*evp++ != NULL)
158 auxvec = (ElfW(auxv_t) *__unbounded) evp;
161 _dl_aux_init (auxvec);
163 # ifdef DL_SYSDEP_OSCHECK
164 if (!__libc_multiple_libcs)
166 /* This needs to run to initiliaze _dl_osversion before TLS
167 setup might check it. */
168 DL_SYSDEP_OSCHECK (__libc_fatal);
172 /* Perform IREL{,A} relocations. */
175 /* Initialize the thread library at least a bit since the libgcc
176 functions are using thread functions if these are available and
177 we need to setup errno. */
178 __pthread_initialize_minimal ();
180 /* Set up the stack checker's canary. */
181 uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard (_dl_random);
182 # ifdef THREAD_SET_STACK_GUARD
183 THREAD_SET_STACK_GUARD (stack_chk_guard);
185 __stack_chk_guard = stack_chk_guard;
189 /* Register the destructor of the dynamic linker if there is any. */
190 if (__builtin_expect (rtld_fini != NULL, 1))
191 __cxa_atexit ((void (*) (void *)) rtld_fini, NULL, NULL);
194 /* Call the initializer of the libc. This is only needed here if we
195 are compiling for the static library in which case we haven't
196 run the constructors in `_dl_start_user'. */
197 __libc_init_first (argc, argv, __environ);
199 /* Register the destructor of the program, if any. */
201 __cxa_atexit ((void (*) (void *)) fini, NULL, NULL);
203 /* Some security at this point. Prevent starting a SUID binary where
204 the standard file descriptors are not opened. We have to do this
205 only for statically linked applications since otherwise the dynamic
206 loader did the work already. */
207 if (__builtin_expect (__libc_enable_secure, 0))
208 __libc_check_standard_fds ();
211 /* Call the initializer of the program, if any. */
213 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_IMPCALLS, 0))
214 GLRO(dl_debug_printf) ("\ninitialize program: %s\n\n", argv[0]);
217 (*init) (argc, argv, __environ MAIN_AUXVEC_PARAM);
220 /* Auditing checkpoint: we have a new object. */
221 if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
223 struct audit_ifaces *afct = GLRO(dl_audit);
224 struct link_map *head = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
225 for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
227 if (afct->preinit != NULL)
228 afct->preinit (&head->l_audit[cnt].cookie);
236 if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_IMPCALLS, 0))
237 GLRO(dl_debug_printf) ("\ntransferring control: %s\n\n", argv[0]);
240 #ifdef HAVE_CLEANUP_JMP_BUF
241 /* Memory for the cancellation buffer. */
242 struct pthread_unwind_buf unwind_buf;
245 not_first_call = setjmp ((struct __jmp_buf_tag *) unwind_buf.cancel_jmp_buf);
246 if (__builtin_expect (! not_first_call, 1))
248 struct pthread *self = THREAD_SELF;
250 /* Store old info. */
251 unwind_buf.priv.data.prev = THREAD_GETMEM (self, cleanup_jmp_buf);
252 unwind_buf.priv.data.cleanup = THREAD_GETMEM (self, cleanup);
254 /* Store the new cleanup handler info. */
255 THREAD_SETMEM (self, cleanup_jmp_buf, &unwind_buf);
257 /* Run the program. */
258 result = main (argc, argv, __environ MAIN_AUXVEC_PARAM);
262 /* Remove the thread-local data. */
264 PTHFCT_CALL (ptr__nptl_deallocate_tsd, ());
266 extern void __nptl_deallocate_tsd (void) __attribute ((weak));
267 __nptl_deallocate_tsd ();
270 /* One less thread. Decrement the counter. If it is zero we
271 terminate the entire process. */
274 unsigned int *ptr = __libc_pthread_functions.ptr_nthreads;
279 extern unsigned int __nptl_nthreads __attribute ((weak));
280 unsigned int *const ptr = &__nptl_nthreads;
283 if (! atomic_decrement_and_test (ptr))
284 /* Not much left to do but to exit the thread, not the process. */
288 /* Nothing fancy, just call the function. */
289 result = main (argc, argv, __environ MAIN_AUXVEC_PARAM);