/* *  arch/s390/kernel/signal.c * *  S390 version *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation *    Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com) * *    Based on Intel version *  *  Copyright (C) 1991, 1992  Linus Torvalds * *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson */#include <linux/config.h>#include <linux/sched.h>#include <linux/mm.h>#include <linux/smp.h>#include <linux/smp_lock.h>#include <linux/kernel.h>#include <linux/signal.h>#include <linux/errno.h>#include <linux/wait.h>#include <linux/ptrace.h>#include <linux/unistd.h>#include <linux/stddef.h>#include <linux/tty.h>#include <linux/personality.h>#include <linux/binfmts.h>#include <asm/ucontext.h>#include <asm/uaccess.h>#include <asm/lowcore.h>#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))typedef struct {	__u8 callee_used_stack[__SIGNAL_FRAMESIZE];	struct sigcontext sc;	_sigregs sregs;	int signo;	__u8 retcode[S390_SYSCALL_SIZE];} sigframe;typedef struct {	__u8 callee_used_stack[__SIGNAL_FRAMESIZE];	__u8 retcode[S390_SYSCALL_SIZE];	struct siginfo info;	struct ucontext uc;} rt_sigframe;int do_signal(struct pt_regs *regs, sigset_t *oldset);/* * Atomically swap in the new signal mask, and wait for a signal. */asmlinkage intsys_sigsuspend(struct pt_regs * regs, int history0, int history1,	       old_sigset_t mask){	sigset_t saveset;	mask &= _BLOCKABLE;	spin_lock_irq(&current->sighand->siglock);	saveset = current->blocked;	siginitset(&current->blocked, mask);	recalc_sigpending();	spin_unlock_irq(&current->sighand->siglock);	regs->gprs[2] = -EINTR;	while (1) {		set_current_state(TASK_INTERRUPTIBLE);		schedule();		if (do_signal(regs, &saveset))			return -EINTR;	}}asmlinkage longsys_rt_sigsuspend(struct pt_regs *regs, sigset_t __user *unewset,						size_t sigsetsize){	sigset_t saveset, newset;	/* XXX: Don't preclude handling different sized sigset_t's.  */	if (sigsetsize != sizeof(sigset_t))		return -EINVAL;	if (copy_from_user(&newset, unewset, sizeof(newset)))		return -EFAULT;	sigdelsetmask(&newset, ~_BLOCKABLE);	spin_lock_irq(&current->sighand->siglock);	saveset = current->blocked;	current->blocked = newset;	recalc_sigpending();	spin_unlock_irq(&current->sighand->siglock);	regs->gprs[2] = -EINTR;	while (1) {		set_current_state(TASK_INTERRUPTIBLE);		schedule();		if (do_signal(regs, &saveset))			return -EINTR;	}}asmlinkage longsys_sigaction(int sig, const struct old_sigaction __user *act,	      struct old_sigaction __user *oact){	struct k_sigaction new_ka, old_ka;	int ret;	if (act) {		old_sigset_t mask;		if (verify_area(VERIFY_READ, act, sizeof(*act)) ||		    __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||		    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))			return -EFAULT;		__get_user(new_ka.sa.sa_flags, &act->sa_flags);		__get_user(mask, &act->sa_mask);		siginitset(&new_ka.sa.sa_mask, mask);	}	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);	if (!ret && oact) {		if (verify_area(VERIFY_WRITE, oact, sizeof(*oact)) ||		    __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||		    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))			return -EFAULT;		__put_user(old_ka.sa.sa_flags, &oact->sa_flags);		__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);	}	return ret;}asmlinkage longsys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,					struct pt_regs *regs){	return do_sigaltstack(uss, uoss, regs->gprs[15]);}/* Returns non-zero on fault. */static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs){	unsigned long old_mask = regs->psw.mask;	int err;  	save_access_regs(current->thread.acrs);	/* Copy a 'clean' PSW mask to the user to avoid leaking	   information about whether PER is currently on.  */	regs->psw.mask = PSW_MASK_MERGE(PSW_USER_BITS, regs->psw.mask);	err = __copy_to_user(&sregs->regs.psw, &regs->psw,			     sizeof(sregs->regs.psw)+sizeof(sregs->regs.gprs));	regs->psw.mask = old_mask;	if (err != 0)		return err;	err = __copy_to_user(&sregs->regs.acrs, current->thread.acrs,			     sizeof(sregs->regs.acrs));	if (err != 0)		return err;	/* 	 * We have to store the fp registers to current->thread.fp_regs	 * to merge them with the emulated registers.	 */	save_fp_regs(&current->thread.fp_regs);	return __copy_to_user(&sregs->fpregs, &current->thread.fp_regs,			      sizeof(s390_fp_regs));}/* Returns positive number on error */static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs){	unsigned long old_mask = regs->psw.mask;	int err;	/* Alwys make any pending restarted system call return -EINTR */	current_thread_info()->restart_block.fn = do_no_restart_syscall;	err = __copy_from_user(&regs->psw, &sregs->regs.psw,			       sizeof(sregs->regs.psw)+sizeof(sregs->regs.gprs));	regs->psw.mask = PSW_MASK_MERGE(old_mask, regs->psw.mask);	regs->psw.addr |= PSW_ADDR_AMODE;	if (err)		return err;	err = __copy_from_user(&current->thread.acrs, &sregs->regs.acrs,			       sizeof(sregs->regs.acrs));	if (err)		return err;	restore_access_regs(current->thread.acrs);	err = __copy_from_user(&current->thread.fp_regs, &sregs->fpregs,			       sizeof(s390_fp_regs));	current->thread.fp_regs.fpc &= FPC_VALID_MASK;	if (err)		return err;	restore_fp_regs(&current->thread.fp_regs);	regs->trap = -1;	/* disable syscall checks */	return 0;}asmlinkage long sys_sigreturn(struct pt_regs *regs){	sigframe __user *frame = (sigframe __user *)regs->gprs[15];	sigset_t set;	if (verify_area(VERIFY_READ, frame, sizeof(*frame)))		goto badframe;	if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))		goto badframe;	sigdelsetmask(&set, ~_BLOCKABLE);	spin_lock_irq(&current->sighand->siglock);	current->blocked = set;	recalc_sigpending();	spin_unlock_irq(&current->sighand->siglock);	if (restore_sigregs(regs, &frame->sregs))		goto badframe;	return regs->gprs[2];badframe:	force_sig(SIGSEGV, current);	return 0;}asmlinkage long sys_rt_sigreturn(struct pt_regs *regs){	rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15];	sigset_t set;	if (verify_area(VERIFY_READ, frame, sizeof(*frame)))		goto badframe;	if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))		goto badframe;	sigdelsetmask(&set, ~_BLOCKABLE);	spin_lock_irq(&current->sighand->siglock);	current->blocked = set;	recalc_sigpending();	spin_unlock_irq(&current->sighand->siglock);	if (restore_sigregs(regs, &frame->uc.uc_mcontext))		goto badframe;	/* It is more difficult to avoid calling this function than to	   call it and ignore errors.  */	do_sigaltstack(&frame->uc.uc_stack, NULL, regs->gprs[15]);	return regs->gprs[2];badframe:	force_sig(SIGSEGV, current);	return 0;}/* * Set up a signal frame. *//* * Determine which stack to use.. */static inline void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size){	unsigned long sp;	/* Default to using normal stack */	sp = regs->gprs[15];	/* This is the X/Open sanctioned signal stack switching.  */	if (ka->sa.sa_flags & SA_ONSTACK) {		if (! on_sig_stack(sp))			sp = current->sas_ss_sp + current->sas_ss_size;	}	/* This is the legacy signal stack switching. */	else if (!user_mode(regs) &&		 !(ka->sa.sa_flags & SA_RESTORER) &&		 ka->sa.sa_restorer) {		sp = (unsigned long) ka->sa.sa_restorer;	}	return (void __user *)((sp - frame_size) & -8ul);}static inline int map_signal(int sig){	if (current_thread_info()->exec_domain	    && current_thread_info()->exec_domain->signal_invmap	    && sig < 32)		return current_thread_info()->exec_domain->signal_invmap[sig];	else		return sig;}static void setup_frame(int sig, struct k_sigaction *ka,			sigset_t *set, struct pt_regs * regs){	sigframe __user *frame;	frame = get_sigframe(ka, regs, sizeof(sigframe));	if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe)))		goto give_sigsegv;	if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))		goto give_sigsegv;	if (save_sigregs(regs, &frame->sregs))		goto give_sigsegv;	if (__put_user(&frame->sregs, &frame->sc.sregs))		goto give_sigsegv;	/* Set up to return from userspace.  If provided, use a stub	   already in userspace.  */	if (ka->sa.sa_flags & SA_RESTORER) {                regs->gprs[14] = (unsigned long)			ka->sa.sa_restorer | PSW_ADDR_AMODE;	} else {                regs->gprs[14] = (unsigned long)			frame->retcode | PSW_ADDR_AMODE;		if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn,	                       (u16 __user *)(frame->retcode)))			goto give_sigsegv;	}	/* Set up backchain. */	if (__put_user(regs->gprs[15], (addr_t __user *) frame))		goto give_sigsegv;	/* Set up registers for signal handler */	regs->gprs[15] = (unsigned long) frame;	regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;	regs->gprs[2] = map_signal(sig);	regs->gprs[3] = (unsigned long) &frame->sc;	/* We forgot to include these in the sigcontext.	   To avoid breaking binary compatibility, they are passed as args. */	regs->gprs[4] = current->thread.trap_no;	regs->gprs[5] = current->thread.prot_addr;	/* Place signal number on stack to allow backtrace from handler.  */	if (__put_user(regs->gprs[2], (int __user *) &frame->signo))		goto give_sigsegv;	return;give_sigsegv:	force_sigsegv(sig, current);}static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,			   sigset_t *set, struct pt_regs * regs){	int err = 0;	rt_sigframe __user *frame;	frame = get_sigframe(ka, regs, sizeof(rt_sigframe));	if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe)))		goto give_sigsegv;	if (copy_siginfo_to_user(&frame->info, info))		goto give_sigsegv;	/* 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->gprs[15]),			  &frame->uc.uc_stack.ss_flags);	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);	err |= save_sigregs(regs, &frame->uc.uc_mcontext);	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));	if (err)		goto give_sigsegv;	/* Set up to return from userspace.  If provided, use a stub	   already in userspace.  */	if (ka->sa.sa_flags & SA_RESTORER) {                regs->gprs[14] = (unsigned long)			ka->sa.sa_restorer | PSW_ADDR_AMODE;	} else {                regs->gprs[14] = (unsigned long)			frame->retcode | PSW_ADDR_AMODE;		err |= __put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,	                          (u16 __user *)(frame->retcode));	}	/* Set up backchain. */	if (__put_user(regs->gprs[15], (addr_t __user *) frame))		goto give_sigsegv;	/* Set up registers for signal handler */	regs->gprs[15] = (unsigned long) frame;	regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;	regs->gprs[2] = map_signal(sig);	regs->gprs[3] = (unsigned long) &frame->info;	regs->gprs[4] = (unsigned long) &frame->uc;	return;give_sigsegv:	force_sigsegv(sig, 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){	/* 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_NODEFER)) {		spin_lock_irq(&current->sighand->siglock);		sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);		sigaddset(&current->blocked,sig);		recalc_sigpending();		spin_unlock_irq(&current->sighand->siglock);	}}/* * 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){	unsigned long retval = 0, continue_addr = 0, restart_addr = 0;	siginfo_t info;	int signr;	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;	/* Are we from a system call? */	if (regs->trap == __LC_SVC_OLD_PSW) {		continue_addr = regs->psw.addr;		restart_addr = continue_addr - regs->ilc;		retval = regs->gprs[2];		/* Prepare for system call restart.  We do this here so that a		   debugger will see the already changed PSW. */		if (retval == -ERESTARTNOHAND ||		    retval == -ERESTARTSYS ||		    retval == -ERESTARTNOINTR) {			regs->gprs[2] = regs->orig_gpr2;			regs->psw.addr = restart_addr;		} else if (retval == -ERESTART_RESTARTBLOCK) {			regs->gprs[2] = -EINTR;		}	}	/* Get signal to deliver.  When running under ptrace, at this point	   the debugger may change all our registers ... */	signr = get_signal_to_deliver(&info, &ka, regs, NULL);	/* Depending on the signal settings we may need to revert the	   decision to restart the system call. */	if (signr > 0 && regs->psw.addr == restart_addr) {		if (retval == -ERESTARTNOHAND		    || (retval == -ERESTARTSYS			 && !(current->sighand->action[signr-1].sa.sa_flags			      & SA_RESTART))) {			regs->gprs[2] = -EINTR;			regs->psw.addr = continue_addr;		}	}	if (signr > 0) {		/* Whee!  Actually deliver the signal.  */#ifdef CONFIG_S390_SUPPORT		if (test_thread_flag(TIF_31BIT)) {			extern void handle_signal32(unsigned long sig,						    struct k_sigaction *ka,						    siginfo_t *info,						    sigset_t *oldset,						    struct pt_regs *regs);			handle_signal32(signr, &ka, &info, oldset, regs);			return 1;	        }#endif		handle_signal(signr, &ka, &info, oldset, regs);		return 1;	}	/* Restart a different system call. */	if (retval == -ERESTART_RESTARTBLOCK	    && regs->psw.addr == continue_addr) {		regs->gprs[2] = __NR_restart_syscall;		set_thread_flag(TIF_RESTART_SVC);	}	return 0;}