#include <u.h>#include <signal.h>#include <libc.h>#include "9proc.h"#undef fork intp9fork(void){	int pid;	sigset_t all, old; 	sigfillset(&all);	sigprocmask(SIG_SETMASK, &all, &old);	pid = fork();	if(pid == 0){		_clearuproc();		_p9uproc(0);	}	sigprocmask(SIG_SETMASK, &old, nil);	return pid;}