diff options
Diffstat (limited to 'libc/stdlib')
| -rw-r--r-- | libc/stdlib/Makefile | 16 | ||||
| -rw-r--r-- | libc/stdlib/atexit.c | 246 |
2 files changed, 184 insertions, 78 deletions
diff --git a/libc/stdlib/Makefile b/libc/stdlib/Makefile index 210a2eeba..49d739703 100644 --- a/libc/stdlib/Makefile +++ b/libc/stdlib/Makefile @@ -79,7 +79,10 @@ endif # wcstod wcstof wcstold MSRC2 = atexit.c -MOBJ2 = atexit.o on_exit.o __exit_handler.o exit.o +MOBJ2 = on_exit.o __cxa_atexit.o __cxa_finalize.o __exit_handler.o exit.o +ifeq ($(COMPAT_ATEXIT),y) +MOBJ2 += old_atexit.o +endif CSRC = \ abort.c getenv.c mkdtemp.c mktemp.c realpath.c mkstemp.c mkstemp64.c \ @@ -95,13 +98,20 @@ COBJS=$(patsubst %.c,%.o, $(CSRC)) OBJS=$(MOBJ) $(MOBJx) $(MOBJ1) $(MOBJ1x) $(MOBJ2) $(COBJS) +NONSHARED_OBJS=atexit.o + OBJ_LIST=../obj.stdlib -all: $(OBJ_LIST) subdirs +NONSHARED_OBJ_LIST=../nonshared_obj.stdlib + +all: $(OBJ_LIST) $(NONSHARED_OBJ_LIST) subdirs $(OBJ_LIST): $(OBJS) echo $(patsubst %, stdlib/%, $(OBJS)) > $(OBJ_LIST) +$(NONSHARED_OBJ_LIST): $(NONSHARED_OBJS) + echo $(patsubst %, stdlib/%, $(NONSHARED_OBJS)) > $(NONSHARED_OBJ_LIST) + $(MOBJ): $(MSRC) $(CC) $(CFLAGS) -DL_$* $< -c -o $*.o $(STRIPTOOL) -x -R .note -R .comment $*.o @@ -118,7 +128,7 @@ $(MOBJ1x): $(MSRC1) $(CC) $(CFLAGS) -DL_$* -D__UCLIBC_DO_XLOCALE $< -c -o $*.o $(STRIPTOOL) -x -R .note -R .comment $*.o -$(MOBJ2): $(MSRC2) +$(MOBJ2) atexit.o: $(MSRC2) $(CC) $(CFLAGS) -DL_$* $< -c -o $*.o $(STRIPTOOL) -x -R .note -R .comment $*.o diff --git a/libc/stdlib/atexit.c b/libc/stdlib/atexit.c index 1962c1b63..e9710b038 100644 --- a/libc/stdlib/atexit.c +++ b/libc/stdlib/atexit.c @@ -32,6 +32,9 @@ * August 2002 Erik Andersen * Added locking so atexit and friends can be thread safe * + * August 2005 Stephen Warren + * Added __cxa_atexit and __cxa_finalize support + * */ #define _GNU_SOURCE @@ -39,7 +42,7 @@ #include <unistd.h> #include <stdlib.h> #include <errno.h> - +#include <atomic.h> #ifdef __UCLIBC_HAS_THREADS__ #include <pthread.h> @@ -54,9 +57,12 @@ extern pthread_mutex_t mylock; typedef void (*aefuncp) (void); /* atexit function pointer */ typedef void (*oefuncp) (int, void *); /* on_exit function pointer */ +typedef void (*cxaefuncp) (void *); /* __cxa_atexit function pointer */ typedef enum { - ef_atexit, - ef_on_exit + ef_free, + ef_in_use, + ef_on_exit, + ef_cxa_atexit } ef_type; /* exit function types */ /* this is in the L_exit object */ @@ -67,13 +73,21 @@ extern int __exit_slots; extern int __exit_count; extern void __exit_handler(int); struct exit_function { - ef_type type; /* ef_atexit or ef_on_exit */ + /* + * 'type' should be of type of the 'enum ef_type' above but since we + * need this element in an atomic operation we have to use 'long int'. + */ + long int type; /* enum ef_type */ union { - aefuncp atexit; - struct { - oefuncp func; - void *arg; - } on_exit; + struct { + oefuncp func; + void *arg; + } on_exit; + struct { + cxaefuncp func; + void *arg; + void* dso_handle; + } cxa_atexit; } funcs; }; #ifdef __UCLIBC_DYNAMIC_ATEXIT__ @@ -81,46 +95,37 @@ extern struct exit_function *__exit_function_table; #else extern struct exit_function __exit_function_table[__UCLIBC_MAX_ATEXIT]; #endif +extern struct exit_function *__new_exitfn (void); -#ifdef L_atexit - /* +/* this is in the L___cxa_atexit object */ +extern int __cxa_atexit (cxaefuncp, void *arg, void *dso_handle); + + +/* remove old_atexit after 0.9.29 */ +#if defined(L_atexit) || defined(L_old_atexit) +extern void *__dso_handle __attribute__ ((__weak__)); + +/* * register a function to be called at normal program termination * (the registered function takes no arguments) - */ -int atexit(aefuncp func) -{ - struct exit_function *efp; - - LOCK; - if (func) { -#ifdef __UCLIBC_DYNAMIC_ATEXIT__ - /* If we are out of function table slots, make some more */ - if (__exit_slots < __exit_count+1) { - efp=realloc(__exit_function_table, - (__exit_slots+20)*sizeof(struct exit_function)); - if (efp==NULL) { - UNLOCK; - __set_errno(ENOMEM); - return -1; - } - __exit_function_table = efp; - __exit_slots+=20; - } + */ +#ifdef L_atexit +int attribute_hidden atexit(aefuncp func) #else - if (__exit_count >= __UCLIBC_MAX_ATEXIT) { - UNLOCK; - __set_errno(ENOMEM); - return -1; - } +int old_atexit(aefuncp func) #endif - __exit_cleanup = __exit_handler; /* enable cleanup */ - efp = &__exit_function_table[__exit_count++]; - efp->type = ef_atexit; - efp->funcs.atexit = func; - } - UNLOCK; - return 0; +{ + /* + * glibc casts aefuncp to cxaefuncp. + * This seems dodgy, but I guess callling a function with more + * parameters than it needs will work everywhere? + */ + return __cxa_atexit((cxaefuncp)func, NULL, + &__dso_handle == NULL ? NULL : __dso_handle); } +#ifndef L_atexit +weak_alias(old_atexit,atexit); +#endif #endif #ifdef L_on_exit @@ -133,41 +138,92 @@ int atexit(aefuncp func) int on_exit(oefuncp func, void *arg) { struct exit_function *efp; + + if (func == NULL) { + return 0; + } - LOCK; - if (func) { -#ifdef __UCLIBC_DYNAMIC_ATEXIT__ - /* If we are out of function table slots, make some more */ - if (__exit_slots < __exit_count+1) { - efp=realloc(__exit_function_table, - (__exit_slots+20)*sizeof(struct exit_function)); - if (efp==NULL) { - UNLOCK; - __set_errno(ENOMEM); - return -1; - } - __exit_function_table=efp; - __exit_slots+=20; - } -#else - if (__exit_count >= __UCLIBC_MAX_ATEXIT) { - UNLOCK; - __set_errno(ENOMEM); - return -1; - } + efp = __new_exitfn(); + if (efp == NULL) { + return -1; + } + + efp->funcs.on_exit.func = func; + efp->funcs.on_exit.arg = arg; + /* assign last for thread safety, since we're now unlocked */ + efp->type = ef_on_exit; + + return 0; +} #endif - __exit_cleanup = __exit_handler; /* enable cleanup */ - efp = &__exit_function_table[__exit_count++]; - efp->type = ef_on_exit; - efp->funcs.on_exit.func = func; - efp->funcs.on_exit.arg = arg; +#ifdef L___cxa_atexit +extern int __cxa_atexit (cxaefuncp func, void *arg, void *dso_handle) +{ + struct exit_function *efp; + + if (func == NULL) { + return 0; } - UNLOCK; + + efp = __new_exitfn(); + if (efp == NULL) { + return -1; + } + + efp->funcs.cxa_atexit.func = func; + efp->funcs.cxa_atexit.arg = arg; + efp->funcs.cxa_atexit.dso_handle = dso_handle; + /* assign last for thread safety, since we're now unlocked */ + efp->type = ef_cxa_atexit; + return 0; } #endif +#ifdef L___cxa_finalize +/* + * If D is non-NULL, call all functions registered with `__cxa_atexit' + * with the same dso handle. Otherwise, if D is NULL, call all of the + * registered handlers. + */ +void __cxa_finalize (void *dso_handle) +{ + struct exit_function *efp; + int exit_count_snapshot = __exit_count; + + /* In reverse order */ + while (exit_count_snapshot) { + efp = &__exit_function_table[--exit_count_snapshot]; + + /* + * We check dso_handle match before we verify the type of the union entry. + * However, the atomic_exchange will validate that we were really "allowed" + * to read dso_handle... + */ + if ((dso_handle == NULL || dso_handle == efp->funcs.cxa_atexit.dso_handle) + /* We don't want to run this cleanup more than once. */ + && !atomic_compare_and_exchange_bool_acq(&efp->type, ef_free, ef_cxa_atexit) + ) { + /* glibc passes status (0) too, but that's not in the prototype */ + (*efp->funcs.cxa_atexit.func)(efp->funcs.cxa_atexit.arg); + } + } + +#if 0 /* haven't looked into this yet... */ + /* + * Remove the registered fork handlers. We do not have to + * unregister anything if the program is going to terminate anyway. + */ +#ifdef UNREGISTER_ATFORK + if (d != NULL) { + UNREGISTER_ATFORK (d); + } +#endif +#endif +} +#endif + #ifdef L___exit_handler int __exit_count = 0; /* Number of registered exit functions */ #ifdef __UCLIBC_DYNAMIC_ATEXIT__ @@ -177,6 +233,45 @@ int __exit_slots = 0; /* Size of __exit_function_table */ struct exit_function __exit_function_table[__UCLIBC_MAX_ATEXIT]; #endif +/* + * Find and return a new exit_function pointer, for atexit, + * onexit and __cxa_atexit to initialize + */ +struct exit_function *__new_exitfn(void) +{ + struct exit_function *efp; + + LOCK; + +#ifdef __UCLIBC_DYNAMIC_ATEXIT__ + /* If we are out of function table slots, make some more */ + if (__exit_slots < __exit_count+1) { + efp=realloc(__exit_function_table, + (__exit_slots+20)*sizeof(struct exit_function)); + if (efp == NULL) { + UNLOCK; + __set_errno(ENOMEM); + return 0; + } + __exit_function_table = efp; + __exit_slots += 20; + } +#else + if (__exit_count >= __UCLIBC_MAX_ATEXIT) { + UNLOCK; + __set_errno(ENOMEM); + return 0; + } +#endif + + __exit_cleanup = __exit_handler; /* enable cleanup */ + efp = &__exit_function_table[__exit_count++]; + efp->type = ef_in_use; + + UNLOCK; + + return efp; +} /* * Handle the work of executing the registered exit functions @@ -196,11 +291,12 @@ void __exit_handler(int status) (efp->funcs.on_exit.func) (status, efp->funcs.on_exit.arg); } break; - case ef_atexit: - if (efp->funcs.atexit) { - (efp->funcs.atexit) (); - } - break; + case ef_cxa_atexit: + if (efp->funcs.cxa_atexit.func) { + /* glibc passes status too, but that's not in the prototype */ + (efp->funcs.cxa_atexit.func) (efp->funcs.cxa_atexit.arg); + } + break; } } #ifdef __UCLIBC_DYNAMIC_ATEXIT__ |