diff options
Diffstat (limited to 'libc/misc/internals')
| -rw-r--r-- | libc/misc/internals/__uClibc_main.c | 167 |
1 files changed, 111 insertions, 56 deletions
diff --git a/libc/misc/internals/__uClibc_main.c b/libc/misc/internals/__uClibc_main.c index 53f897d9f..aa4655cec 100644 --- a/libc/misc/internals/__uClibc_main.c +++ b/libc/misc/internals/__uClibc_main.c @@ -20,8 +20,6 @@ * Prototypes. */ extern int main(int argc, char **argv, char **envp); -extern void weak_function _init(void); -extern void weak_function _fini(void); extern void weak_function _stdio_init(void); extern int *weak_const_function __errno_location(void); extern int *weak_const_function __h_errno_location(void); @@ -36,10 +34,11 @@ extern void weak_function __pthread_initialize_minimal(void); + /* * Declare the __environ global variable and create a weak alias environ. - * Note: Apparently we must initialize __environ for the weak environ - * symbol to be included. + * Note: Apparently we must initialize __environ to ensure that the weak + * environ symbol is also included. */ char **__environ = 0; @@ -47,68 +46,124 @@ weak_alias(__environ, environ); +/* __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_start_main. + */ -void __attribute__ ((__noreturn__)) -__uClibc_main(int argc, char **argv, char **envp) +void __uClibc_init(void) { - /* If we are dynamically linked the shared lib loader - * already did this for us. But if we are statically - * linked, we need to do this for ourselves. */ - if (__environ==NULL) { - /* Statically linked. */ - __environ = envp; - } + static int been_there_done_that = 0; + + if (been_there_done_that) + return; + been_there_done_that++; #ifdef __UCLIBC_HAS_THREADS__ - if (likely(__pthread_initialize_minimal!=NULL)) - __pthread_initialize_minimal(); + /* Before we start initialzing uClibc we have to call + * __pthread_initialize_minimal so we can use pthread_locks + * whenever they are needed. + */ + if (likely(__pthread_initialize_minimal!=NULL)) + __pthread_initialize_minimal(); #endif #if 0 - /* Some security at this point. Prevent starting a SUID binary - * where the standard file descriptors are not opened. We have - * to do this only for statically linked applications since - * otherwise the dynamic loader did the work already. */ - if (unlikely (__libc_enable_secure!=NULL)) - __libc_check_standard_fds (); + /* Some security at this point. Prevent starting a SUID binary + * where the standard file descriptors are not opened. We have + * to do this only for statically linked applications since + * otherwise the dynamic loader did the work already. */ + if (unlikely (__libc_enable_secure!=NULL)) + __libc_check_standard_fds (); #endif #ifdef __UCLIBC_HAS_LOCALE__ - /* Initialize the global locale structure. */ - if (likely(_locale_init!=NULL)) - _locale_init(); + /* Initialize the global locale structure. */ + if (likely(_locale_init!=NULL)) + _locale_init(); #endif - /* - * Initialize stdio here. In the static library case, this will - * be bypassed if not needed because of the weak alias above. - */ - if (likely(_stdio_init != NULL)) - _stdio_init(); - - /* Arrange for dtors to run at exit. */ - if (likely(_fini!=NULL && atexit)) { - atexit (&_fini); - } - - /* Run all ctors now. */ - if (likely(_init!=NULL)) - _init(); - - /* - * 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(__errno_location!=NULL)) - *(__errno_location()) = 0; - - /* Set h_errno to 0 as well */ - if (likely(__h_errno_location!=NULL)) - *(__h_errno_location()) = 0; - - /* - * Finally, invoke application's main and then exit. - */ - exit(main(argc, argv, envp)); + /* + * Initialize stdio here. In the static library case, this will + * be bypassed if not needed because of the weak alias above. + */ + if (likely(_stdio_init != NULL)) + _stdio_init(); + +} + + +/* __uClibc_start_main is the new main stub for uClibc. This function is + * called from crt0 (version 0.9.16 or newer), after ALL shared libraries + * are initialized, just before we call the application's main function. + */ +void __attribute__ ((__noreturn__)) +__uClibc_start_main(int argc, char **argv, char **envp, + void (*app_init)(void), void (*app_fini)(void)) +{ + + /* If we are dynamically linked the shared lib loader already + * did this for us. But if we are statically linked, we need + * to do this for ourselves. */ + if (__environ==NULL) { + /* Statically linked. */ + __environ = envp; + } + + /* 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(); + + /* Arrange for the application's dtors to run before we exit. */ + if (app_fini!=NULL && atexit) { + atexit (app_fini); + } + + /* Run all the application's ctors now. */ + if (app_init!=NULL) { + app_init(); + } + + /* 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(__errno_location!=NULL)) + *(__errno_location()) = 0; + + /* Set h_errno to 0 as well */ + if (likely(__h_errno_location!=NULL)) + *(__h_errno_location()) = 0; + + /* + * Finally, invoke application's main and then exit. + */ + exit(main(argc, argv, envp)); +} + + +/* __uClibc_main is the old main stub of the uClibc. This + * function is called from crt0 (uClibc 0.9.15 and older) after + * ALL shared libraries are initialized, and just before we call + * the application's main() function. + * + * Attention: This stub does not call the .init/.fini sections of + * the application. If you need this, please fix your uClibc port + * so that __uClibc_start_main is called by your crt0.S with + * _init and _fini properly set. +*/ +void __attribute__ ((__noreturn__)) +__uClibc_main(int argc, char **argv, char ** envp) +{ + __uClibc_start_main(argc, argv, envp, NULL, NULL); } + |