/* *  linux/kernel/signal.c * *  (C) 1991  Linus Torvalds */#include <linux/sched.h>#include <linux/kernel.h>#include <asm/segment.h>#include <signal.h>volatile void do_exit(int error_code);int sys_sgetmask(){	return current->blocked;}int sys_ssetmask(int newmask){	int old=current->blocked;	current->blocked = newmask & ~(1<<(SIGKILL-1));	return old;}static inline void save_old(char * from,char * to){	int i;	verify_area(to, sizeof(struct sigaction));	for (i=0 ; i< sizeof(struct sigaction) ; i++) {		put_fs_byte(*from,to);		from++;		to++;	}}static inline void get_new(char * from,char * to){	int i;	for (i=0 ; i< sizeof(struct sigaction) ; i++)		*(to++) = get_fs_byte(from++);}int sys_signal(int signum, long handler, long restorer){	struct sigaction tmp;	if (signum<1 || signum>32 || signum==SIGKILL)		return -1;	tmp.sa_handler = (void (*)(int)) handler;	tmp.sa_mask = 0;	tmp.sa_flags = SA_ONESHOT | SA_NOMASK;	tmp.sa_restorer = (void (*)(void)) restorer;	handler = (long) current->sigaction[signum-1].sa_handler;	current->sigaction[signum-1] = tmp;	return handler;}int sys_sigaction(int signum, const struct sigaction * action,	struct sigaction * oldaction){	struct sigaction tmp;	if (signum<1 || signum>32 || signum==SIGKILL)		return -1;	tmp = current->sigaction[signum-1];	get_new((char *) action,		(char *) (signum-1+current->sigaction));	if (oldaction)		save_old((char *) &tmp,(char *) oldaction);	if (current->sigaction[signum-1].sa_flags & SA_NOMASK)		current->sigaction[signum-1].sa_mask = 0;	else		current->sigaction[signum-1].sa_mask |= (1<<(signum-1));	return 0;}void do_signal(long signr,long eax, long ebx, long ecx, long edx,	long fs, long es, long ds,	long eip, long cs, long eflags,	unsigned long * esp, long ss){	unsigned long sa_handler;	long old_eip=eip;	struct sigaction * sa = current->sigaction + signr - 1;	int longs;	unsigned long * tmp_esp;	sa_handler = (unsigned long) sa->sa_handler;	if (sa_handler==1)		return;	if (!sa_handler) {		if (signr==SIGCHLD)			return;		else			do_exit(1<<(signr-1));	}	if (sa->sa_flags & SA_ONESHOT)		sa->sa_handler = NULL;	*(&eip) = sa_handler;	longs = (sa->sa_flags & SA_NOMASK)?7:8;	*(&esp) -= longs;	verify_area(esp,longs*4);	tmp_esp=esp;	put_fs_long((long) sa->sa_restorer,tmp_esp++);	put_fs_long(signr,tmp_esp++);	if (!(sa->sa_flags & SA_NOMASK))		put_fs_long(current->blocked,tmp_esp++);	put_fs_long(eax,tmp_esp++);	put_fs_long(ecx,tmp_esp++);	put_fs_long(edx,tmp_esp++);	put_fs_long(eflags,tmp_esp++);	put_fs_long(old_eip,tmp_esp++);	current->blocked |= sa->sa_mask;}