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- /*
- * Copyright (C) 2006 by Steven J. Hill <sjhill@realitydiluted.com>
- * Copyright (C) 2001 by Manuel Novoa III <mjn3@uclibc.org>
- * Copyright (C) 2000-2005 Erik Andersen <andersen@uclibc.org>
- *
- * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
- *
- * __uClibc_main is the routine to be called by all the arch-specific
- * versions of crt1.S in uClibc.
- *
- * It is meant to handle any special initialization needed by the library
- * such as setting the global variable(s) __environ (environ) and
- * initializing the stdio package. Using weak symbols, the latter is
- * avoided in the static library case.
- */
- #include <features.h>
- #include <unistd.h>
- #include <stdlib.h>
- #include <string.h>
- #include <elf.h>
- #include <link.h>
- #include <bits/uClibc_page.h>
- #include <paths.h>
- #include <errno.h>
- #include <netdb.h>
- #include <stdio.h>
- #ifndef __ARCH_HAS_NO_LDSO__
- #include <fcntl.h>
- #endif
- #ifdef __UCLIBC_HAS_THREADS_NATIVE__
- #include <not-cancel.h>
- #include <atomic.h>
- #include <tls.h>
- #endif
- #ifdef __UCLIBC_HAS_THREADS__
- #include <pthread.h>
- #endif
- #ifdef __UCLIBC_HAS_LOCALE__
- #include <locale.h>
- #endif
- /* Are we in a secure process environment or are we dealing
- * with setuid stuff? If we are dynamically linked, then we
- * already have _dl_secure, otherwise we need to re-examine
- * auxvt[] below.
- */
- int _pe_secure = 0;
- libc_hidden_data_def(_pe_secure)
- #if !defined(SHARED) && defined(__FDPIC__)
- struct funcdesc_value
- {
- void *entry_point;
- void *got_value;
- } __attribute__((__aligned__(8)));
- /* Prevent compiler optimization that removes GOT assignment.
- Due to optimization passes (block split and move), in the rare case
- where use r9 is the single instruction in a block we can have the
- following behaviour:
- - this block is marked as a forward block since use is not
- considered as an active instruction after reload pass.
- - In this case a jump in this block can be moved to the start of the
- next one and so remove use in this flow of instructions which can
- lead to a removal of r9 restoration after a call. */
- #define _dl_stabilize_funcdesc(val) \
- ({ __asm__ ("" : "+m" (*(val))); (val); })
- static void fdpic_init_array_jump(void *addr)
- {
- struct funcdesc_value *fm = (struct funcdesc_value *) fdpic_init_array_jump;
- struct funcdesc_value fd = {addr, fm->got_value};
- void (*pf)(void) = (void*) _dl_stabilize_funcdesc(&fd);
- (*pf)();
- }
- #endif
- #ifndef SHARED
- void *__libc_stack_end = NULL;
- # ifdef __UCLIBC_HAS_SSP__
- # include <dl-osinfo.h>
- static uintptr_t stack_chk_guard;
- # ifndef THREAD_SET_STACK_GUARD
- /* Only exported for architectures that don't store the stack guard canary
- * in thread local area. */
- /* for gcc-4.1 non-TLS */
- uintptr_t __stack_chk_guard attribute_relro;
- # endif
- # endif
- /*
- * Needed to initialize _dl_phdr when statically linked
- */
- void internal_function _dl_aux_init (ElfW(auxv_t) *av);
- #ifdef __UCLIBC_HAS_THREADS__
- /*
- * uClibc internal locking requires that we have weak aliases
- * for dummy functions in case a single threaded application is linked.
- * This needs to be in compilation unit that is pulled always
- * in or linker will disregard these weaks.
- */
- static int __pthread_return_0 (pthread_mutex_t *unused) { return 0; }
- weak_alias (__pthread_return_0, __pthread_mutex_lock)
- weak_alias (__pthread_return_0, __pthread_mutex_trylock)
- weak_alias (__pthread_return_0, __pthread_mutex_unlock)
- int weak_function
- __pthread_mutex_init(pthread_mutex_t *mutex, const pthread_mutexattr_t *attr)
- {
- return 0;
- }
- void weak_function
- _pthread_cleanup_push_defer(struct _pthread_cleanup_buffer *__buffer,
- void (*__routine) (void *), void *__arg)
- {
- __buffer->__routine = __routine;
- __buffer->__arg = __arg;
- }
- void weak_function
- _pthread_cleanup_pop_restore(struct _pthread_cleanup_buffer *__buffer,
- int __execute)
- {
- if (__execute)
- __buffer->__routine(__buffer->__arg);
- }
- #endif /* __UCLIBC_HAS_THREADS__ */
- #endif /* !SHARED */
- /* Defeat compiler optimization which assumes function addresses are never NULL */
- static __always_inline int not_null_ptr(const void *p)
- {
- const void *q;
- __asm__ (""
- : "=r" (q) /* output */
- : "0" (p) /* input */
- );
- return q != 0;
- }
- /*
- * Prototypes.
- */
- #ifdef __UCLIBC_HAS_THREADS__
- #if !defined (__UCLIBC_HAS_THREADS_NATIVE__) || defined (SHARED)
- extern void weak_function __pthread_initialize_minimal(void);
- #else
- extern void __pthread_initialize_minimal(void);
- #endif
- #endif
- #ifndef SHARED
- extern void __libc_setup_tls (size_t tcbsize, size_t tcbalign);
- #endif
- /* If __UCLIBC_FORMAT_SHARED_FLAT__, all array initialisation and finalisation
- * is handled by the routines passed to __uClibc_main(). */
- #if defined (__UCLIBC_CTOR_DTOR__) && !defined (__UCLIBC_FORMAT_SHARED_FLAT__)
- extern void _dl_app_init_array(void);
- extern void _dl_app_fini_array(void);
- # ifndef SHARED
- /* These magic symbols are provided by the linker. */
- extern void (*__preinit_array_start []) (void) attribute_hidden;
- extern void (*__preinit_array_end []) (void) attribute_hidden;
- extern void (*__init_array_start []) (void) attribute_hidden;
- extern void (*__init_array_end []) (void) attribute_hidden;
- extern void (*__fini_array_start []) (void) attribute_hidden;
- extern void (*__fini_array_end []) (void) attribute_hidden;
- # endif
- #endif
- #ifdef SHARED
- extern int _dl_secure;
- #endif
- extern size_t _dl_pagesize;
- const char *__uclibc_progname = "";
- #if !defined __UCLIBC_HAS___PROGNAME__ && defined __USE_GNU && defined __UCLIBC_HAS_PROGRAM_INVOCATION_NAME__
- # define __progname program_invocation_short_name
- # define __progname_full program_invocation_name
- #endif
- #if defined __UCLIBC_HAS___PROGNAME__ || (defined __USE_GNU && defined __UCLIBC_HAS_PROGRAM_INVOCATION_NAME__)
- const char *__progname = "";
- /* psm: why have a visible __progname_full? */
- const char *__progname_full = "";
- # if defined __UCLIBC_HAS___PROGNAME__ && defined __USE_GNU && defined __UCLIBC_HAS_PROGRAM_INVOCATION_NAME__
- weak_alias (__progname, program_invocation_short_name)
- weak_alias (__progname_full, program_invocation_name)
- # endif
- #endif
- /*
- * Declare the __environ global variable and create a weak alias environ.
- * This must be initialized; we cannot have a weak alias into bss.
- */
- char **__environ = 0;
- weak_alias(__environ, environ)
- size_t __pagesize = 0;
- #ifndef O_NOFOLLOW
- # define O_NOFOLLOW 0
- #endif
- #ifndef __ARCH_HAS_NO_LDSO__
- static void __check_one_fd(int fd, int mode)
- {
- /* Check if the specified fd is already open */
- if (fcntl(fd, F_GETFD) == -1)
- {
- /* The descriptor is probably not open, so try to use /dev/null */
- int nullfd = open(_PATH_DEVNULL, mode);
- /* /dev/null is major=1 minor=3. Make absolutely certain
- * that is in fact the device that we have opened and not
- * some other wierd file... [removed in uclibc] */
- if (nullfd!=fd)
- {
- abort();
- }
- }
- }
- #ifndef SHARED
- static int __check_suid(void)
- {
- uid_t uid, euid;
- gid_t gid, egid;
- uid = getuid();
- euid = geteuid();
- if (uid != euid)
- return 1;
- gid = getgid();
- egid = getegid();
- if (gid != egid)
- return 1;
- return 0; /* we are not suid */
- }
- #endif
- #endif
- /* __uClibc_init completely initialize uClibc so it is ready to use.
- *
- * On ELF systems (with a dynamic loader) this function must be called
- * from the dynamic loader (see TIS and ELF Specification), so that
- * constructors of shared libraries (which depend on libc) can use all
- * the libc code without restriction. For this we link the shared
- * version of the uClibc with -init __uClibc_init so DT_INIT for
- * uClibc is the address of __uClibc_init
- *
- * In all other cases we call it from the main stub
- * __uClibc_main.
- */
- extern void __uClibc_init(void) attribute_hidden;
- void __uClibc_init(void)
- {
- /* Don't recurse */
- if (__pagesize)
- return;
- /* Setup an initial value. This may not be perfect, but is
- * better than malloc using __pagesize=0 for atexit, ctors, etc. */
- __pagesize = PAGE_SIZE;
- #ifdef __UCLIBC_HAS_THREADS__
- #if defined (__UCLIBC_HAS_THREADS_NATIVE__) && !defined (SHARED)
- /* Unlike in the dynamically linked case the dynamic linker has not
- taken care of initializing the TLS data structures. */
- __libc_setup_tls (TLS_TCB_SIZE, TLS_TCB_ALIGN);
- #endif
- /* Before we start initializing uClibc we have to call
- * __pthread_initialize_minimal so we can use pthread_locks
- * whenever they are needed.
- */
- #if !defined (__UCLIBC_HAS_THREADS_NATIVE__) || defined (SHARED)
- if (likely(__pthread_initialize_minimal!=NULL))
- #endif
- __pthread_initialize_minimal();
- #endif
- #ifndef SHARED
- # ifdef __UCLIBC_HAS_SSP__
- /* Set up the stack checker's canary. */
- stack_chk_guard = _dl_setup_stack_chk_guard();
- # ifdef THREAD_SET_STACK_GUARD
- THREAD_SET_STACK_GUARD (stack_chk_guard);
- # else
- __stack_chk_guard = stack_chk_guard;
- # endif
- # endif
- #endif
- #ifdef __UCLIBC_HAS_LOCALE__
- /* Initialize the global locale structure. */
- if (likely(not_null_ptr(_locale_init)))
- _locale_init();
- #endif
- /*
- * Initialize stdio here. In the static library case, this will
- * be bypassed if not needed because of the weak alias above.
- * Thus we get a nice size savings because the stdio functions
- * won't be pulled into the final static binary unless used.
- */
- if (likely(not_null_ptr(_stdio_init)))
- _stdio_init();
- }
- #ifdef __UCLIBC_CTOR_DTOR__
- void attribute_hidden (*__app_fini)(void) = NULL;
- #endif
- void attribute_hidden (*__rtld_fini)(void) = NULL;
- extern void __uClibc_fini(void) attribute_hidden;
- void __uClibc_fini(void)
- {
- #ifdef __UCLIBC_CTOR_DTOR__
- /* If __UCLIBC_FORMAT_SHARED_FLAT__, all array finalisation is handled
- * by __app_fini. */
- # ifdef SHARED
- _dl_app_fini_array();
- # elif !defined (__UCLIBC_FORMAT_SHARED_FLAT__)
- size_t i = __fini_array_end - __fini_array_start;
- while (i-- > 0)
- #if !defined(SHARED) && defined(__FDPIC__)
- fdpic_init_array_jump(__fini_array_start[i]);
- #else
- (*__fini_array_start [i]) ();
- #endif
- # endif
- if (__app_fini != NULL)
- (__app_fini)();
- #endif
- if (__rtld_fini != NULL)
- (__rtld_fini)();
- }
- #ifndef SHARED
- extern void __nptl_deallocate_tsd (void) __attribute ((weak));
- extern unsigned int __nptl_nthreads __attribute ((weak));
- #endif
- /* __uClibc_main is the new main stub for uClibc. This function is
- * called from crt1 (version 0.9.28 or newer), after ALL shared libraries
- * are initialized, just before we call the application's main function.
- */
- void __uClibc_main(int (*main)(int, char **, char **), int argc,
- char **argv, void (*app_init)(void), void (*app_fini)(void),
- void (*rtld_fini)(void),
- void *stack_end attribute_unused) attribute_noreturn;
- void __uClibc_main(int (*main)(int, char **, char **), int argc,
- char **argv, void (*app_init)(void), void (*app_fini)(void),
- void (*rtld_fini)(void), void *stack_end attribute_unused)
- {
- #ifndef SHARED
- unsigned long *aux_dat;
- ElfW(auxv_t) auxvt[AT_EGID + 1];
- #endif
- #ifdef __UCLIBC_HAS_THREADS_NATIVE__
- /* Result of the 'main' function. */
- int result;
- #endif
- #ifndef SHARED
- __libc_stack_end = stack_end;
- #endif
- __rtld_fini = rtld_fini;
- /* The environment begins right after argv. */
- __environ = &argv[argc + 1];
- /* If the first thing after argv is the arguments
- * then the environment is empty. */
- if ((char *) __environ == *argv) {
- /* Make __environ point to the NULL at argv[argc] */
- __environ = &argv[argc];
- }
- #ifndef SHARED
- /* Pull stuff from the ELF header when possible */
- memset(auxvt, 0x00, sizeof(auxvt));
- aux_dat = (unsigned long*)__environ;
- while (*aux_dat) {
- aux_dat++;
- }
- aux_dat++;
- while (*aux_dat) {
- ElfW(auxv_t) *auxv_entry = (ElfW(auxv_t) *) aux_dat;
- if (auxv_entry->a_type <= AT_EGID) {
- memcpy(&(auxvt[auxv_entry->a_type]), auxv_entry, sizeof(ElfW(auxv_t)));
- }
- aux_dat += 2;
- }
- /* Get the program headers (_dl_phdr) from the aux vector
- It will be used into __libc_setup_tls. */
- _dl_aux_init (auxvt);
- #endif
- /* We need to initialize uClibc. If we are dynamically linked this
- * may have already been completed by the shared lib loader. We call
- * __uClibc_init() regardless, to be sure the right thing happens. */
- __uClibc_init();
- #ifndef __ARCH_HAS_NO_LDSO__
- /* Make certain getpagesize() gives the correct answer.
- * _dl_pagesize is defined into ld.so if SHARED or into libc.a otherwise. */
- __pagesize = _dl_pagesize;
- #ifndef SHARED
- /* Prevent starting SUID binaries where the stdin. stdout, and
- * stderr file descriptors are not already opened. */
- if ((auxvt[AT_UID].a_un.a_val == (size_t)-1 && __check_suid()) ||
- (auxvt[AT_UID].a_un.a_val != (size_t)-1 &&
- (auxvt[AT_UID].a_un.a_val != auxvt[AT_EUID].a_un.a_val ||
- auxvt[AT_GID].a_un.a_val != auxvt[AT_EGID].a_un.a_val)))
- #else
- if (_dl_secure)
- #endif
- {
- __check_one_fd (STDIN_FILENO, O_RDONLY | O_NOFOLLOW);
- __check_one_fd (STDOUT_FILENO, O_RDWR | O_NOFOLLOW);
- __check_one_fd (STDERR_FILENO, O_RDWR | O_NOFOLLOW);
- _pe_secure = 1 ;
- }
- else
- _pe_secure = 0 ;
- #endif
- __uclibc_progname = *argv;
- #if defined __UCLIBC_HAS___PROGNAME__ || (defined __USE_GNU && defined __UCLIBC_HAS_PROGRAM_INVOCATION_NAME__)
- if (*argv != NULL) {
- __progname_full = *argv;
- __progname = strrchr(*argv, '/');
- if (__progname != NULL)
- ++__progname;
- else
- __progname = *argv;
- }
- #endif
- #ifdef __UCLIBC_CTOR_DTOR__
- /* Arrange for the application's dtors to run before we exit. */
- __app_fini = app_fini;
- /* If __UCLIBC_FORMAT_SHARED_FLAT__, all array initialisation is handled
- * by __app_init. */
- # if !defined (SHARED) && !defined (__UCLIBC_FORMAT_SHARED_FLAT__)
- /* For dynamically linked executables the preinit array is executed by
- the dynamic linker (before initializing any shared object).
- For static executables, preinit happens rights before init. */
- {
- const size_t size = __preinit_array_end - __preinit_array_start;
- size_t i;
- for (i = 0; i < size; i++)
- #if !defined(SHARED) && defined(__FDPIC__)
- fdpic_init_array_jump(__preinit_array_start[i]);
- #else
- (*__preinit_array_start [i]) ();
- #endif
- }
- # endif
- /* Run all the application's ctors now. */
- if (app_init!=NULL) {
- app_init();
- }
- /* If __UCLIBC_FORMAT_SHARED_FLAT__, all array initialisation is handled
- * by __app_init. */
- # ifdef SHARED
- _dl_app_init_array();
- # elif !defined (__UCLIBC_FORMAT_SHARED_FLAT__)
- {
- const size_t size = __init_array_end - __init_array_start;
- size_t i;
- for (i = 0; i < size; i++)
- #if !defined(SHARED) && defined(__FDPIC__)
- fdpic_init_array_jump(__init_array_start[i]);
- #else
- (*__init_array_start [i]) ();
- #endif
- }
- # endif
- #endif
- /* Note: It is possible that any initialization done above could
- * have resulted in errno being set nonzero, so set it to 0 before
- * we call main.
- */
- if (likely(not_null_ptr(__errno_location)))
- *(__errno_location()) = 0;
- /* Set h_errno to 0 as well */
- if (likely(not_null_ptr(__h_errno_location)))
- *(__h_errno_location()) = 0;
- #if defined HAVE_CLEANUP_JMP_BUF && defined __UCLIBC_HAS_THREADS_NATIVE__
- /* Memory for the cancellation buffer. */
- struct pthread_unwind_buf unwind_buf;
- int not_first_call;
- not_first_call =
- setjmp ((struct __jmp_buf_tag *) unwind_buf.cancel_jmp_buf);
- if (__builtin_expect (! not_first_call, 1))
- {
- struct pthread *self = THREAD_SELF;
- /* Store old info. */
- unwind_buf.priv.data.prev = THREAD_GETMEM (self, cleanup_jmp_buf);
- unwind_buf.priv.data.cleanup = THREAD_GETMEM (self, cleanup);
- /* Store the new cleanup handler info. */
- THREAD_SETMEM (self, cleanup_jmp_buf, &unwind_buf);
- /* Run the program. */
- result = main (argc, argv, __environ);
- }
- else
- {
- /* Remove the thread-local data. */
- __nptl_deallocate_tsd ();
- /* One less thread. Decrement the counter. If it is zero we
- terminate the entire process. */
- result = 0;
- unsigned int *const ptr = &__nptl_nthreads;
- if (ptr && ! atomic_decrement_and_test (ptr))
- /* Not much left to do but to exit the thread, not the process. */
- __exit_thread_inline (0);
- }
- exit (result);
- #else
- /*
- * Finally, invoke application's main and then exit.
- */
- exit (main (argc, argv, __environ));
- #endif
- }
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