[linux-2.6-block.git] / arch / s390 / kernel / signal.c

/*
 *  arch/s390/kernel/signal.c
 *
 *    Copyright (C) IBM Corp. 1999,2006
 *    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/sched.h>
#include <linux/mm.h>
#include <linux/smp.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 <linux/tracehook.h>
#include <linux/syscalls.h>
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#include <asm/lowcore.h>
#include "entry.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;

/*
 * Atomically swap in the new signal mask, and wait for a signal.
 */
SYSCALL_DEFINE3(sigsuspend, int, history0, int, history1, old_sigset_t, mask)
{
	mask &= _BLOCKABLE;
	spin_lock_irq(&current->sighand->siglock);
	current->saved_sigmask = current->blocked;
	siginitset(&current->blocked, mask);
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);

	current->state = TASK_INTERRUPTIBLE;
	schedule();
	set_thread_flag(TIF_RESTORE_SIGMASK);

	return -ERESTARTNOHAND;
}

SYSCALL_DEFINE3(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 (!access_ok(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) ||
		    __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
		    __get_user(mask, &act->sa_mask))
			return -EFAULT;
		siginitset(&new_ka.sa.sa_mask, mask);
	}

	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);

	if (!ret && oact) {
		if (!access_ok(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) ||
		    __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
		    __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
			return -EFAULT;
	}

	return ret;
}

SYSCALL_DEFINE2(sigaltstack, const stack_t __user *, uss,
		stack_t __user *, uoss)
{
	struct pt_regs *regs = task_pt_regs(current);
	return do_sigaltstack(uss, uoss, regs->gprs[15]);
}

/* Returns non-zero on fault. */
static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
{
	_sigregs user_sregs;

	save_access_regs(current->thread.acrs);

	/* Copy a 'clean' PSW mask to the user to avoid leaking
	   information about whether PER is currently on.  */
	user_sregs.regs.psw.mask = PSW_MASK_MERGE(psw_user_bits, regs->psw.mask);
	user_sregs.regs.psw.addr = regs->psw.addr;
	memcpy(&user_sregs.regs.gprs, &regs->gprs, sizeof(sregs->regs.gprs));
	memcpy(&user_sregs.regs.acrs, current->thread.acrs,
	       sizeof(sregs->regs.acrs));
	/* 
	 * 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);
	memcpy(&user_sregs.fpregs, &current->thread.fp_regs,
	       sizeof(s390_fp_regs));
	return __copy_to_user(sregs, &user_sregs, sizeof(_sigregs));
}

/* Returns positive number on error */
static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
{
	int err;
	_sigregs user_sregs;

	/* Alwys make any pending restarted system call return -EINTR */
	current_thread_info()->restart_block.fn = do_no_restart_syscall;

	err = __copy_from_user(&user_sregs, sregs, sizeof(_sigregs));
	if (err)
		return err;
	regs->psw.mask = PSW_MASK_MERGE(regs->psw.mask,
					user_sregs.regs.psw.mask);
	regs->psw.addr = PSW_ADDR_AMODE | user_sregs.regs.psw.addr;
	memcpy(&regs->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
	memcpy(&current->thread.acrs, &user_sregs.regs.acrs,
	       sizeof(sregs->regs.acrs));
	restore_access_regs(current->thread.acrs);

	memcpy(&current->thread.fp_regs, &user_sregs.fpregs,
	       sizeof(s390_fp_regs));
	current->thread.fp_regs.fpc &= FPC_VALID_MASK;

	restore_fp_regs(&current->thread.fp_regs);
	regs->svcnr = 0;	/* disable syscall checks */
	return 0;
}

SYSCALL_DEFINE0(sigreturn)
{
	struct pt_regs *regs = task_pt_regs(current);
	sigframe __user *frame = (sigframe __user *)regs->gprs[15];
	sigset_t set;

	if (!access_ok(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;
}

SYSCALL_DEFINE0(rt_sigreturn)
{
	struct pt_regs *regs = task_pt_regs(current);
	rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15];
	sigset_t set;

	if (!access_ok(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;

	if (do_sigaltstack(&frame->uc.uc_stack, NULL,
			   regs->gprs[15]) == -EFAULT)
		goto badframe;
	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];

	/* Overflow on alternate signal stack gives SIGSEGV. */
	if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
		return (void __user *) -1UL;

	/* This is the X/Open sanctioned signal stack switching.  */
	if (ka->sa.sa_flags & SA_ONSTACK) {
		if (! sas_ss_flags(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 int 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 (frame == (void __user *) -1UL)
		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 0;

give_sigsegv:
	force_sigsegv(sig, current);
	return -EFAULT;
}

static int 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 (frame == (void __user *) -1UL)
		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(NULL, &frame->uc.uc_link);
	err |= __put_user((void __user *)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;
		if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_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->info;
	regs->gprs[4] = (unsigned long) &frame->uc;
	return 0;

give_sigsegv:
	force_sigsegv(sig, current);
	return -EFAULT;
}

/*
 * OK, we're invoking a handler
 */	

static int
handle_signal(unsigned long sig, struct k_sigaction *ka,
	      siginfo_t *info, sigset_t *oldset, struct pt_regs * regs)
{
	int ret;

	/* Set up the stack frame */
	if (ka->sa.sa_flags & SA_SIGINFO)
		ret = setup_rt_frame(sig, ka, info, oldset, regs);
	else
		ret = setup_frame(sig, ka, oldset, regs);

	if (ret == 0) {
		spin_lock_irq(&current->sighand->siglock);
		sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
		if (!(ka->sa.sa_flags & SA_NODEFER))
			sigaddset(&current->blocked,sig);
		recalc_sigpending();
		spin_unlock_irq(&current->sighand->siglock);
	}

	return ret;
}

/*
 * 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.
 */
void do_signal(struct pt_regs *regs)
{
	unsigned long retval = 0, continue_addr = 0, restart_addr = 0;
	siginfo_t info;
	int signr;
	struct k_sigaction ka;
	sigset_t *oldset;

	/*
	 * 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;

	if (test_thread_flag(TIF_RESTORE_SIGMASK))
		oldset = &current->saved_sigmask;
	else
		oldset = &current->blocked;

	/* Are we from a system call? */
	if (regs->svcnr) {
		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. */
		switch (retval) {
		case -ERESTARTNOHAND:
		case -ERESTARTSYS:
		case -ERESTARTNOINTR:
			regs->gprs[2] = regs->orig_gpr2;
			regs->psw.addr = restart_addr;
			break;
		case -ERESTART_RESTARTBLOCK:
			regs->gprs[2] = -EINTR;
		}
		regs->svcnr = 0;	/* Don't deal with this again. */
	}

	/* 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.  */
		int ret;
#ifdef CONFIG_COMPAT
		if (test_thread_flag(TIF_31BIT)) {
			ret = handle_signal32(signr, &ka, &info, oldset, regs);
	        }
		else
#endif
			ret = handle_signal(signr, &ka, &info, oldset, regs);
		if (!ret) {
			/*
			 * A signal was successfully delivered; the saved
			 * sigmask will have been stored in the signal frame,
			 * and will be restored by sigreturn, so we can simply
			 * clear the TIF_RESTORE_SIGMASK flag.
			 */
			if (test_thread_flag(TIF_RESTORE_SIGMASK))
				clear_thread_flag(TIF_RESTORE_SIGMASK);

			/*
			 * If we would have taken a single-step trap
			 * for a normal instruction, act like we took
			 * one for the handler setup.
			 */
			if (current->thread.per_info.single_step)
				set_thread_flag(TIF_SINGLE_STEP);

			/*
			 * Let tracing know that we've done the handler setup.
			 */
			tracehook_signal_handler(signr, &info, &ka, regs,
					 test_thread_flag(TIF_SINGLE_STEP));
		}
		return;
	}

	/*
	 * If there's no signal to deliver, we just put the saved sigmask back.
	 */
	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
		clear_thread_flag(TIF_RESTORE_SIGMASK);
		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
	}

	/* 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);
	}
}

void do_notify_resume(struct pt_regs *regs)
{
	clear_thread_flag(TIF_NOTIFY_RESUME);
	tracehook_notify_resume(regs);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* arch/s390/kernel/signal.c
	3	*
54dfe5dd	4	* Copyright (C) IBM Corp. 1999,2006
1da177e4 LT	5	* Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
	6	*
	7	* Based on Intel version
	8	*
	9	* Copyright (C) 1991, 1992 Linus Torvalds
	10	*
	11	* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
	12	*/
	13
1da177e4 LT	14	#include <linux/sched.h>
	15	#include <linux/mm.h>
	16	#include <linux/smp.h>
1da177e4 LT	17	#include <linux/kernel.h>
	18	#include <linux/signal.h>
	19	#include <linux/errno.h>
	20	#include <linux/wait.h>
	21	#include <linux/ptrace.h>
	22	#include <linux/unistd.h>
	23	#include <linux/stddef.h>
	24	#include <linux/tty.h>
	25	#include <linux/personality.h>
	26	#include <linux/binfmts.h>
753c4dd6	27	#include <linux/tracehook.h>
26689452	28	#include <linux/syscalls.h>
1da177e4 LT	29	#include <asm/ucontext.h>
	30	#include <asm/uaccess.h>
	31	#include <asm/lowcore.h>
a806170e	32	#include "entry.h"
1da177e4 LT	33
	34	#define _BLOCKABLE (~(sigmask(SIGKILL) \| sigmask(SIGSTOP)))
	35
	36
	37	typedef struct
	38	{
	39	__u8 callee_used_stack[__SIGNAL_FRAMESIZE];
	40	struct sigcontext sc;
	41	_sigregs sregs;
	42	int signo;
	43	__u8 retcode[S390_SYSCALL_SIZE];
	44	} sigframe;
	45
	46	typedef struct
	47	{
	48	__u8 callee_used_stack[__SIGNAL_FRAMESIZE];
	49	__u8 retcode[S390_SYSCALL_SIZE];
	50	struct siginfo info;
	51	struct ucontext uc;
	52	} rt_sigframe;
	53
1da177e4 LT	54	/*
	55	* Atomically swap in the new signal mask, and wait for a signal.
	56	*/
26689452	57	SYSCALL_DEFINE3(sigsuspend, int, history0, int, history1, old_sigset_t, mask)
1da177e4	58	{
1da177e4 LT	59	mask &= _BLOCKABLE;
1da177e4 LT	60	spin_lock_irq(&current->sighand->siglock);
54dfe5dd	61	current->saved_sigmask = current->blocked;
1da177e4 LT	62	siginitset(&current->blocked, mask);
	63	recalc_sigpending();
	64	spin_unlock_irq(&current->sighand->siglock);
1da177e4	65
54dfe5dd HC	66	current->state = TASK_INTERRUPTIBLE;
	67	schedule();
	68	set_thread_flag(TIF_RESTORE_SIGMASK);
1da177e4	69
54dfe5dd	70	return -ERESTARTNOHAND;
1da177e4 LT	71	}
1da177e4 LT	72
26689452 HC	73	SYSCALL_DEFINE3(sigaction, int, sig, const struct old_sigaction __user *, act,
26689452 HC	74	struct old_sigaction __user *, oact)
1da177e4 LT	75	{
	76	struct k_sigaction new_ka, old_ka;
	77	int ret;
	78
	79	if (act) {
	80	old_sigset_t mask;
	81	if (!access_ok(VERIFY_READ, act, sizeof(*act)) \|\|
	82	__get_user(new_ka.sa.sa_handler, &act->sa_handler) \|\|
12bae235 HC	83	__get_user(new_ka.sa.sa_restorer, &act->sa_restorer) \|\|
	84	__get_user(new_ka.sa.sa_flags, &act->sa_flags) \|\|
	85	__get_user(mask, &act->sa_mask))
1da177e4	86	return -EFAULT;
1da177e4 LT	87	siginitset(&new_ka.sa.sa_mask, mask);
	88	}
	89
	90	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
	91
	92	if (!ret && oact) {
	93	if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) \|\|
	94	__put_user(old_ka.sa.sa_handler, &oact->sa_handler) \|\|
12bae235 HC	95	__put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) \|\|
	96	__put_user(old_ka.sa.sa_flags, &oact->sa_flags) \|\|
	97	__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
1da177e4	98	return -EFAULT;
1da177e4 LT	99	}
	100
	101	return ret;
	102	}
	103
26689452 HC	104	SYSCALL_DEFINE2(sigaltstack, const stack_t __user *, uss,
26689452 HC	105	stack_t __user *, uoss)
1da177e4	106	{
03ff9a23	107	struct pt_regs *regs = task_pt_regs(current);
1da177e4 LT	108	return do_sigaltstack(uss, uoss, regs->gprs[15]);
	109	}
	110
1da177e4 LT	111	/* Returns non-zero on fault. */
	112	static int save_sigregs(struct pt_regs regs, _sigregs __user sregs)
	113	{
6837a8c3 GS	114	_sigregs user_sregs;
6837a8c3 GS	115
1da177e4 LT	116	save_access_regs(current->thread.acrs);
	117
	118	/* Copy a 'clean' PSW mask to the user to avoid leaking
	119	information about whether PER is currently on. */
c1821c2e	120	user_sregs.regs.psw.mask = PSW_MASK_MERGE(psw_user_bits, regs->psw.mask);
b05e3703 MS	121	user_sregs.regs.psw.addr = regs->psw.addr;
b05e3703 MS	122	memcpy(&user_sregs.regs.gprs, &regs->gprs, sizeof(sregs->regs.gprs));
6837a8c3 GS	123	memcpy(&user_sregs.regs.acrs, current->thread.acrs,
6837a8c3 GS	124	sizeof(sregs->regs.acrs));
1da177e4 LT	125	/*
	126	* We have to store the fp registers to current->thread.fp_regs
	127	* to merge them with the emulated registers.
	128	*/
	129	save_fp_regs(&current->thread.fp_regs);
6837a8c3 GS	130	memcpy(&user_sregs.fpregs, &current->thread.fp_regs,
	131	sizeof(s390_fp_regs));
	132	return __copy_to_user(sregs, &user_sregs, sizeof(_sigregs));
1da177e4 LT	133	}
	134
	135	/* Returns positive number on error */
	136	static int restore_sigregs(struct pt_regs regs, _sigregs __user sregs)
	137	{
1da177e4	138	int err;
6837a8c3	139	_sigregs user_sregs;
1da177e4 LT	140
	141	/* Alwys make any pending restarted system call return -EINTR */
	142	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	143
6837a8c3	144	err = __copy_from_user(&user_sregs, sregs, sizeof(_sigregs));
1da177e4 LT	145	if (err)
1da177e4 LT	146	return err;
b05e3703 MS	147	regs->psw.mask = PSW_MASK_MERGE(regs->psw.mask,
	148	user_sregs.regs.psw.mask);
	149	regs->psw.addr = PSW_ADDR_AMODE \| user_sregs.regs.psw.addr;
	150	memcpy(&regs->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
6837a8c3 GS	151	memcpy(&current->thread.acrs, &user_sregs.regs.acrs,
6837a8c3 GS	152	sizeof(sregs->regs.acrs));
1da177e4 LT	153	restore_access_regs(current->thread.acrs);
1da177e4 LT	154
6837a8c3 GS	155	memcpy(&current->thread.fp_regs, &user_sregs.fpregs,
6837a8c3 GS	156	sizeof(s390_fp_regs));
1da177e4	157	current->thread.fp_regs.fpc &= FPC_VALID_MASK;
1da177e4 LT	158
1da177e4 LT	159	restore_fp_regs(&current->thread.fp_regs);
59da2139	160	regs->svcnr = 0; /* disable syscall checks */
1da177e4 LT	161	return 0;
	162	}
	163
26689452	164	SYSCALL_DEFINE0(sigreturn)
1da177e4	165	{
03ff9a23	166	struct pt_regs *regs = task_pt_regs(current);
1da177e4 LT	167	sigframe __user frame = (sigframe __user )regs->gprs[15];
	168	sigset_t set;
	169
	170	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	171	goto badframe;
	172	if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
	173	goto badframe;
	174
	175	sigdelsetmask(&set, ~_BLOCKABLE);
	176	spin_lock_irq(&current->sighand->siglock);
	177	current->blocked = set;
	178	recalc_sigpending();
	179	spin_unlock_irq(&current->sighand->siglock);
	180
	181	if (restore_sigregs(regs, &frame->sregs))
	182	goto badframe;
	183
	184	return regs->gprs[2];
	185
	186	badframe:
	187	force_sig(SIGSEGV, current);
	188	return 0;
	189	}
	190
26689452	191	SYSCALL_DEFINE0(rt_sigreturn)
1da177e4	192	{
03ff9a23	193	struct pt_regs *regs = task_pt_regs(current);
1da177e4 LT	194	rt_sigframe __user frame = (rt_sigframe __user )regs->gprs[15];
	195	sigset_t set;
	196
	197	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	198	goto badframe;
	199	if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
	200	goto badframe;
	201
	202	sigdelsetmask(&set, ~_BLOCKABLE);
	203	spin_lock_irq(&current->sighand->siglock);
	204	current->blocked = set;
	205	recalc_sigpending();
	206	spin_unlock_irq(&current->sighand->siglock);
	207
	208	if (restore_sigregs(regs, &frame->uc.uc_mcontext))
	209	goto badframe;
	210
4e3df37e CLG	211	if (do_sigaltstack(&frame->uc.uc_stack, NULL,
	212	regs->gprs[15]) == -EFAULT)
	213	goto badframe;
1da177e4 LT	214	return regs->gprs[2];
	215
	216	badframe:
	217	force_sig(SIGSEGV, current);
	218	return 0;
	219	}
	220
	221	/*
	222	* Set up a signal frame.
	223	*/
	224
	225
	226	/*
	227	* Determine which stack to use..
	228	*/
	229	static inline void __user *
	230	get_sigframe(struct k_sigaction ka, struct pt_regs regs, size_t frame_size)
	231	{
	232	unsigned long sp;
	233
	234	/* Default to using normal stack */
	235	sp = regs->gprs[15];
	236
de553438 HC	237	/* Overflow on alternate signal stack gives SIGSEGV. */
	238	if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
	239	return (void __user *) -1UL;
	240
1da177e4 LT	241	/* This is the X/Open sanctioned signal stack switching. */
	242	if (ka->sa.sa_flags & SA_ONSTACK) {
	243	if (! sas_ss_flags(sp))
	244	sp = current->sas_ss_sp + current->sas_ss_size;
	245	}
	246
	247	/* This is the legacy signal stack switching. */
	248	else if (!user_mode(regs) &&
	249	!(ka->sa.sa_flags & SA_RESTORER) &&
	250	ka->sa.sa_restorer) {
	251	sp = (unsigned long) ka->sa.sa_restorer;
	252	}
	253
	254	return (void __user *)((sp - frame_size) & -8ul);
	255	}
	256
	257	static inline int map_signal(int sig)
	258	{
	259	if (current_thread_info()->exec_domain
	260	&& current_thread_info()->exec_domain->signal_invmap
	261	&& sig < 32)
	262	return current_thread_info()->exec_domain->signal_invmap[sig];
	263	else
	264	return sig;
	265	}
	266
54dfe5dd HC	267	static int setup_frame(int sig, struct k_sigaction *ka,
54dfe5dd HC	268	sigset_t set, struct pt_regs regs)
1da177e4 LT	269	{
	270	sigframe __user *frame;
	271
	272	frame = get_sigframe(ka, regs, sizeof(sigframe));
	273	if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe)))
	274	goto give_sigsegv;
	275
de553438 HC	276	if (frame == (void __user *) -1UL)
	277	goto give_sigsegv;
	278
1da177e4 LT	279	if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
	280	goto give_sigsegv;
	281
	282	if (save_sigregs(regs, &frame->sregs))
	283	goto give_sigsegv;
	284	if (__put_user(&frame->sregs, &frame->sc.sregs))
	285	goto give_sigsegv;
	286
	287	/* Set up to return from userspace. If provided, use a stub
	288	already in userspace. */
	289	if (ka->sa.sa_flags & SA_RESTORER) {
	290	regs->gprs[14] = (unsigned long)
	291	ka->sa.sa_restorer \| PSW_ADDR_AMODE;
	292	} else {
	293	regs->gprs[14] = (unsigned long)
	294	frame->retcode \| PSW_ADDR_AMODE;
	295	if (__put_user(S390_SYSCALL_OPCODE \| __NR_sigreturn,
	296	(u16 __user *)(frame->retcode)))
	297	goto give_sigsegv;
	298	}
	299
	300	/* Set up backchain. */
	301	if (__put_user(regs->gprs[15], (addr_t __user *) frame))
	302	goto give_sigsegv;
	303
	304	/* Set up registers for signal handler */
	305	regs->gprs[15] = (unsigned long) frame;
	306	regs->psw.addr = (unsigned long) ka->sa.sa_handler \| PSW_ADDR_AMODE;
	307
	308	regs->gprs[2] = map_signal(sig);
	309	regs->gprs[3] = (unsigned long) &frame->sc;
	310
	311	/* We forgot to include these in the sigcontext.
	312	To avoid breaking binary compatibility, they are passed as args. */
	313	regs->gprs[4] = current->thread.trap_no;
	314	regs->gprs[5] = current->thread.prot_addr;
	315
	316	/* Place signal number on stack to allow backtrace from handler. */
	317	if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
	318	goto give_sigsegv;
54dfe5dd	319	return 0;
1da177e4 LT	320
	321	give_sigsegv:
	322	force_sigsegv(sig, current);
54dfe5dd	323	return -EFAULT;
1da177e4 LT	324	}
1da177e4 LT	325
54dfe5dd	326	static int setup_rt_frame(int sig, struct k_sigaction ka, siginfo_t info,
1da177e4 LT	327	sigset_t set, struct pt_regs regs)
	328	{
	329	int err = 0;
	330	rt_sigframe __user *frame;
	331
	332	frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
	333	if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe)))
	334	goto give_sigsegv;
	335
de553438 HC	336	if (frame == (void __user *) -1UL)
	337	goto give_sigsegv;
	338
1da177e4 LT	339	if (copy_siginfo_to_user(&frame->info, info))
	340	goto give_sigsegv;
	341
	342	/* Create the ucontext. */
	343	err \|= __put_user(0, &frame->uc.uc_flags);
c2814476 AV	344	err \|= __put_user(NULL, &frame->uc.uc_link);
c2814476 AV	345	err \|= __put_user((void __user *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
1da177e4 LT	346	err \|= __put_user(sas_ss_flags(regs->gprs[15]),
	347	&frame->uc.uc_stack.ss_flags);
	348	err \|= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
	349	err \|= save_sigregs(regs, &frame->uc.uc_mcontext);
	350	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	351	if (err)
	352	goto give_sigsegv;
	353
	354	/* Set up to return from userspace. If provided, use a stub
	355	already in userspace. */
	356	if (ka->sa.sa_flags & SA_RESTORER) {
	357	regs->gprs[14] = (unsigned long)
	358	ka->sa.sa_restorer \| PSW_ADDR_AMODE;
	359	} else {
	360	regs->gprs[14] = (unsigned long)
	361	frame->retcode \| PSW_ADDR_AMODE;
b44df334 HC	362	if (__put_user(S390_SYSCALL_OPCODE \| __NR_rt_sigreturn,
	363	(u16 __user *)(frame->retcode)))
	364	goto give_sigsegv;
1da177e4 LT	365	}
	366
	367	/* Set up backchain. */
	368	if (__put_user(regs->gprs[15], (addr_t __user *) frame))
	369	goto give_sigsegv;
	370
	371	/* Set up registers for signal handler */
	372	regs->gprs[15] = (unsigned long) frame;
	373	regs->psw.addr = (unsigned long) ka->sa.sa_handler \| PSW_ADDR_AMODE;
	374
	375	regs->gprs[2] = map_signal(sig);
	376	regs->gprs[3] = (unsigned long) &frame->info;
	377	regs->gprs[4] = (unsigned long) &frame->uc;
54dfe5dd	378	return 0;
1da177e4 LT	379
	380	give_sigsegv:
	381	force_sigsegv(sig, current);
54dfe5dd	382	return -EFAULT;
1da177e4 LT	383	}
	384
	385	/*
	386	* OK, we're invoking a handler
	387	*/
	388
54dfe5dd	389	static int
1da177e4 LT	390	handle_signal(unsigned long sig, struct k_sigaction *ka,
	391	siginfo_t info, sigset_t oldset, struct pt_regs * regs)
	392	{
54dfe5dd HC	393	int ret;
54dfe5dd HC	394
1da177e4 LT	395	/* Set up the stack frame */
1da177e4 LT	396	if (ka->sa.sa_flags & SA_SIGINFO)
54dfe5dd	397	ret = setup_rt_frame(sig, ka, info, oldset, regs);
1da177e4	398	else
54dfe5dd HC	399	ret = setup_frame(sig, ka, oldset, regs);
	400
	401	if (ret == 0) {
	402	spin_lock_irq(&current->sighand->siglock);
	403	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
	404	if (!(ka->sa.sa_flags & SA_NODEFER))
	405	sigaddset(&current->blocked,sig);
	406	recalc_sigpending();
	407	spin_unlock_irq(&current->sighand->siglock);
	408	}
1da177e4	409
54dfe5dd	410	return ret;
1da177e4 LT	411	}
	412
	413	/*
	414	* Note that 'init' is a special process: it doesn't get signals it doesn't
	415	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	416	* mistake.
	417	*
	418	* Note that we go through the signals twice: once to check the signals that
	419	* the kernel can handle, and then we build all the user-level signal handling
	420	* stack-frames in one go after that.
	421	*/
54dfe5dd	422	void do_signal(struct pt_regs *regs)
1da177e4 LT	423	{
	424	unsigned long retval = 0, continue_addr = 0, restart_addr = 0;
	425	siginfo_t info;
	426	int signr;
	427	struct k_sigaction ka;
54dfe5dd	428	sigset_t *oldset;
1da177e4 LT	429
	430	/*
	431	* We want the common case to go fast, which
	432	* is why we may in certain cases get here from
	433	* kernel mode. Just return without doing anything
	434	* if so.
	435	*/
	436	if (!user_mode(regs))
54dfe5dd	437	return;
1da177e4	438
54dfe5dd HC	439	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	440	oldset = &current->saved_sigmask;
	441	else
1da177e4 LT	442	oldset = &current->blocked;
	443
	444	/* Are we from a system call? */
59da2139	445	if (regs->svcnr) {
1da177e4 LT	446	continue_addr = regs->psw.addr;
	447	restart_addr = continue_addr - regs->ilc;
	448	retval = regs->gprs[2];
	449
	450	/* Prepare for system call restart. We do this here so that a
	451	debugger will see the already changed PSW. */
54dfe5dd HC	452	switch (retval) {
	453	case -ERESTARTNOHAND:
	454	case -ERESTARTSYS:
	455	case -ERESTARTNOINTR:
1da177e4 LT	456	regs->gprs[2] = regs->orig_gpr2;
1da177e4 LT	457	regs->psw.addr = restart_addr;
54dfe5dd HC	458	break;
54dfe5dd HC	459	case -ERESTART_RESTARTBLOCK:
1da177e4 LT	460	regs->gprs[2] = -EINTR;
1da177e4 LT	461	}
59da2139	462	regs->svcnr = 0; /* Don't deal with this again. */
1da177e4 LT	463	}
	464
	465	/* Get signal to deliver. When running under ptrace, at this point
	466	the debugger may change all our registers ... */
	467	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	468
	469	/* Depending on the signal settings we may need to revert the
	470	decision to restart the system call. */
	471	if (signr > 0 && regs->psw.addr == restart_addr) {
	472	if (retval == -ERESTARTNOHAND
	473	\|\| (retval == -ERESTARTSYS
	474	&& !(current->sighand->action[signr-1].sa.sa_flags
	475	& SA_RESTART))) {
	476	regs->gprs[2] = -EINTR;
	477	regs->psw.addr = continue_addr;
	478	}
	479	}
	480
	481	if (signr > 0) {
	482	/* Whee! Actually deliver the signal. */
0ac30be4	483	int ret;
347a8dc3	484	#ifdef CONFIG_COMPAT
1da177e4	485	if (test_thread_flag(TIF_31BIT)) {
0ac30be4	486	ret = handle_signal32(signr, &ka, &info, oldset, regs);
1da177e4	487	}
0ac30be4	488	else
1da177e4	489	#endif
0ac30be4 RM	490	ret = handle_signal(signr, &ka, &info, oldset, regs);
0ac30be4 RM	491	if (!ret) {
54dfe5dd HC	492	/*
	493	* A signal was successfully delivered; the saved
	494	* sigmask will have been stored in the signal frame,
	495	* and will be restored by sigreturn, so we can simply
	496	* clear the TIF_RESTORE_SIGMASK flag.
	497	*/
	498	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	499	clear_thread_flag(TIF_RESTORE_SIGMASK);
0ac30be4 RM	500
	501	/*
	502	* If we would have taken a single-step trap
	503	* for a normal instruction, act like we took
	504	* one for the handler setup.
	505	*/
	506	if (current->thread.per_info.single_step)
	507	set_thread_flag(TIF_SINGLE_STEP);
753c4dd6 MS	508
	509	/*
	510	* Let tracing know that we've done the handler setup.
	511	*/
	512	tracehook_signal_handler(signr, &info, &ka, regs,
	513	test_thread_flag(TIF_SINGLE_STEP));
54dfe5dd HC	514	}
	515	return;
	516	}
	517
	518	/*
	519	* If there's no signal to deliver, we just put the saved sigmask back.
	520	*/
	521	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
	522	clear_thread_flag(TIF_RESTORE_SIGMASK);
	523	sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
1da177e4 LT	524	}
	525
	526	/* Restart a different system call. */
	527	if (retval == -ERESTART_RESTARTBLOCK
	528	&& regs->psw.addr == continue_addr) {
	529	regs->gprs[2] = __NR_restart_syscall;
	530	set_thread_flag(TIF_RESTART_SVC);
	531	}
1da177e4	532	}
753c4dd6 MS	533
	534	void do_notify_resume(struct pt_regs *regs)
	535	{
	536	clear_thread_flag(TIF_NOTIFY_RESUME);
	537	tracehook_notify_resume(regs);
	538	}