int signal;	frame = get_sigframe(ka, regs, sizeof(*frame));	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))		goto give_sigsegv;	signal = current->exec_domain		&& current->exec_domain->signal_invmap		&& sig < 32		? current->exec_domain->signal_invmap[sig]		: sig;	err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);	if (_NSIG_WORDS > 1) {		err |= __copy_to_user(frame->extramask, &set->sig[1],				      sizeof(frame->extramask));	}	/* Set up to return from userspace.  If provided, use a stub	   already in userspace.  */	if (ka->sa.sa_flags & SA_RESTORER) {		regs->gpr[GPR_LP] = (unsigned long) ka->sa.sa_restorer;	} else {		/* Note, these encodings are _little endian_!  */		/* addi  __NR_sigreturn, r0, r12  */		err |= __put_user(0x6600 | (__NR_sigreturn << 16),				  frame->tramp + 0);		/* trap 0 */		err |= __put_user(0x010007e0,				  frame->tramp + 1);		regs->gpr[GPR_LP] = (unsigned long)frame->tramp;		flush_cache_sigtramp (regs->gpr[GPR_LP]);	}	if (err)		goto give_sigsegv;	/* Set up registers for signal handler */	regs->gpr[GPR_SP] = (unsigned long) frame;	regs->gpr[GPR_ARG0] = signal; /* Arg for signal handler */	regs->pc = (unsigned long) ka->sa.sa_handler;	set_fs(USER_DS);#if DEBUG_SIG	printk("SIG deliver (%s:%d): sp=%p pc=%08lx ra=%08lx\n",		current->comm, current->pid, frame, regs->pc, );#endif	return;give_sigsegv:	if (sig == SIGSEGV)		ka->sa.sa_handler = SIG_DFL;	force_sig(SIGSEGV, current);}static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,			   sigset_t *set, struct pt_regs *regs){	struct rt_sigframe *frame;	int err = 0;	int signal;	frame = get_sigframe(ka, regs, sizeof(*frame));	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))		goto give_sigsegv;	signal = current->exec_domain		&& current->exec_domain->signal_invmap		&& sig < 32		? current->exec_domain->signal_invmap[sig]		: sig;	err |= __put_user(&frame->info, &frame->pinfo);	err |= __put_user(&frame->uc, &frame->puc);	err |= copy_siginfo_to_user(&frame->info, info);	/* Create the ucontext.  */	err |= __put_user(0, &frame->uc.uc_flags);	err |= __put_user(0, &frame->uc.uc_link);	err |= __put_user((void *)current->sas_ss_sp,			  &frame->uc.uc_stack.ss_sp);	err |= __put_user(sas_ss_flags(regs->gpr[GPR_SP]),			  &frame->uc.uc_stack.ss_flags);	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);	err |= setup_sigcontext(&frame->uc.uc_mcontext,			        regs, set->sig[0]);	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));	/* Set up to return from userspace.  If provided, use a stub	   already in userspace.  */	if (ka->sa.sa_flags & SA_RESTORER) {		regs->gpr[GPR_LP] = (unsigned long) ka->sa.sa_restorer;	} else {		/* Note, these encodings are _little endian_!  */		/* addi  __NR_sigreturn, r0, r12  */		err |= __put_user(0x6600 | (__NR_sigreturn << 16),				  frame->tramp + 0);		/* trap 0 */		err |= __put_user(0x010007e0,				  frame->tramp + 1);		regs->gpr[GPR_LP] = (unsigned long)frame->tramp;		flush_cache_sigtramp (regs->gpr[GPR_LP]);	}	if (err)		goto give_sigsegv;	/* Set up registers for signal handler */	regs->gpr[GPR_SP] = (unsigned long) frame;	regs->gpr[GPR_ARG0] = signal; /* Arg for signal handler */	regs->pc = (unsigned long) ka->sa.sa_handler;	set_fs(USER_DS);#if DEBUG_SIG	printk("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",		current->comm, current->pid, frame, regs->pc, regs->pr);#endif	return;give_sigsegv:	if (sig == SIGSEGV)		ka->sa.sa_handler = SIG_DFL;	force_sig(SIGSEGV, current);}/* * OK, we're invoking a handler */	static voidhandle_signal(unsigned long sig, struct k_sigaction *ka,	      siginfo_t *info, sigset_t *oldset, struct pt_regs * regs){	/* Are we from a system call? */	if (PT_REGS_SYSCALL (regs)) {		/* If so, check system call restarting.. */		switch (regs->gpr[GPR_RVAL]) {			case -ERESTARTNOHAND:				regs->gpr[GPR_RVAL] = -EINTR;				break;			case -ERESTARTSYS:				if (!(ka->sa.sa_flags & SA_RESTART)) {					regs->gpr[GPR_RVAL] = -EINTR;					break;				}			/* fallthrough */			case -ERESTARTNOINTR:				regs->gpr[12] = PT_REGS_SYSCALL (regs);				regs->pc -= 4; /* Size of `trap 0' insn.  */		}		PT_REGS_SET_SYSCALL (regs, 0);	}	/* Set up the stack frame */	if (ka->sa.sa_flags & SA_SIGINFO)		setup_rt_frame(sig, ka, info, oldset, regs);	else		setup_frame(sig, ka, oldset, regs);	if (ka->sa.sa_flags & SA_ONESHOT)		ka->sa.sa_handler = SIG_DFL;	if (!(ka->sa.sa_flags & SA_NODEFER)) {		spin_lock_irq(&current->sigmask_lock);		sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);		sigaddset(&current->blocked,sig);		recalc_sigpending(current);		spin_unlock_irq(&current->sigmask_lock);	}}/* * Note that 'init' is a special process: it doesn't get signals it doesn't * want to handle. Thus you cannot kill init even with a SIGKILL even by * mistake. * * Note that we go through the signals twice: once to check the signals that * the kernel can handle, and then we build all the user-level signal handling * stack-frames in one go after that. */int do_signal(struct pt_regs *regs, sigset_t *oldset){	siginfo_t info;	struct k_sigaction *ka;	/*	 * We want the common case to go fast, which	 * is why we may in certain cases get here from	 * kernel mode. Just return without doing anything	 * if so.	 */	if (!user_mode(regs))		return 1;	if (!oldset)		oldset = &current->blocked;	for (;;) {		unsigned long signr;		spin_lock_irq(&current->sigmask_lock);		signr = dequeue_signal(&current->blocked, &info);		spin_unlock_irq(&current->sigmask_lock);		if (!signr)			break;		if ((current->ptrace & PT_PTRACED) && signr != SIGKILL) {			/* Let the debugger run.  */			current->exit_code = signr;			current->state = TASK_STOPPED;			notify_parent(current, SIGCHLD);			schedule();			/* We're back.  Did the debugger cancel the sig?  */			if (!(signr = current->exit_code))				continue;			current->exit_code = 0;			/* The debugger continued.  Ignore SIGSTOP.  */			if (signr == SIGSTOP)				continue;			/* Update the siginfo structure.  Is this good?  */			if (signr != info.si_signo) {				info.si_signo = signr;				info.si_errno = 0;				info.si_code = SI_USER;				info.si_pid = current->p_pptr->pid;				info.si_uid = current->p_pptr->uid;			}			/* If the (new) signal is now blocked, requeue it.  */			if (sigismember(&current->blocked, signr)) {				send_sig_info(signr, &info, current);				continue;			}		}		ka = &current->sig->action[signr-1];		if (ka->sa.sa_handler == SIG_IGN) {			if (signr != SIGCHLD)				continue;			/* Check for SIGCHLD: it's special.  */			while (sys_wait4(-1, NULL, WNOHANG, NULL) > 0)				/* nothing */;			continue;		}		if (ka->sa.sa_handler == SIG_DFL) {			int exit_code = signr;			/* Init gets no signals it doesn't want.  */			if (current->pid == 1)				continue;			switch (signr) {			case SIGCONT: case SIGCHLD: case SIGWINCH:				continue;			case SIGTSTP: case SIGTTIN: case SIGTTOU:				if (is_orphaned_pgrp(current->pgrp))					continue;				/* FALLTHRU */			case SIGSTOP:				current->state = TASK_STOPPED;				current->exit_code = signr;				if (!(current->p_pptr->sig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDSTOP))					notify_parent(current, SIGCHLD);				schedule();				continue;			case SIGQUIT: case SIGILL: case SIGTRAP:			case SIGABRT: case SIGFPE: case SIGSEGV:			case SIGBUS: case SIGSYS: case SIGXCPU: case SIGXFSZ:				if (do_coredump(signr, regs))					exit_code |= 0x80;				/* FALLTHRU */			default:				sigaddset(&current->pending.signal, signr);				recalc_sigpending(current);				current->flags |= PF_SIGNALED;				do_exit(exit_code);				/* NOTREACHED */			}		}		/* Whee!  Actually deliver the signal.  */		handle_signal(signr, ka, &info, oldset, regs);		return 1;	}	/* Did we come from a system call? */	if (PT_REGS_SYSCALL (regs)) {		/* Restart the system call - no handlers present */		if (regs->gpr[GPR_RVAL] == -ERESTARTNOHAND ||		    regs->gpr[GPR_RVAL] == -ERESTARTSYS ||		    regs->gpr[GPR_RVAL] == -ERESTARTNOINTR) {			regs->gpr[12] = PT_REGS_SYSCALL (regs);			regs->pc -= 4; /* Size of `trap 0' insn.  */		}	}	return 0;}