/*  $Id: signal32.c,v 1.74 2002/02/09 19:49:30 davem Exp $
 *  arch/sparc64/kernel/signal32.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
 *  Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
 *  Copyright (C) 1997 Eddie C. Dost   (ecd@skynet.be)
 *  Copyright (C) 1997,1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
 */

#include <linux/sched.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/mm.h>
#include <linux/tty.h>
#include <linux/smp_lock.h>
#include <linux/binfmts.h>
#include <linux/compat.h>
#include <linux/bitops.h>

#include <asm/uaccess.h>
#include <asm/ptrace.h>
#include <asm/svr4.h>
#include <asm/pgtable.h>
#include <asm/psrcompat.h>
#include <asm/fpumacro.h>
#include <asm/visasm.h>
#include <asm/compat_signal.h>

#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))

/* Signal frames: the original one (compatible with SunOS):
 *
 * Set up a signal frame... Make the stack look the way SunOS
 * expects it to look which is basically:
 *
 * ---------------------------------- <-- %sp at signal time
 * Struct sigcontext
 * Signal address
 * Ptr to sigcontext area above
 * Signal code
 * The signal number itself
 * One register window
 * ---------------------------------- <-- New %sp
 */
struct signal_sframe32 {
	struct reg_window32 sig_window;
	int sig_num;
	int sig_code;
	/* struct sigcontext32 * */ u32 sig_scptr;
	int sig_address;
	struct sigcontext32 sig_context;
	unsigned int extramask[_COMPAT_NSIG_WORDS - 1];
};

/* This magic should be in g_upper[0] for all upper parts
 * to be valid.
 */
#define SIGINFO_EXTRA_V8PLUS_MAGIC	0x130e269
typedef struct {
	unsigned int g_upper[8];
	unsigned int o_upper[8];
	unsigned int asi;
} siginfo_extra_v8plus_t;

/* 
 * And the new one, intended to be used for Linux applications only
 * (we have enough in there to work with clone).
 * All the interesting bits are in the info field.
 */
struct new_signal_frame32 {
	struct sparc_stackf32	ss;
	__siginfo32_t		info;
	/* __siginfo_fpu32_t * */ u32 fpu_save;
	unsigned int		insns[2];
	unsigned int		extramask[_COMPAT_NSIG_WORDS - 1];
	unsigned int		extra_size; /* Should be sizeof(siginfo_extra_v8plus_t) */
	/* Only valid if (info.si_regs.psr & (PSR_VERS|PSR_IMPL)) == PSR_V8PLUS */
	siginfo_extra_v8plus_t	v8plus;
	__siginfo_fpu_t		fpu_state;
};

typedef struct compat_siginfo{
	int si_signo;
	int si_errno;
	int si_code;

	union {
		int _pad[SI_PAD_SIZE32];

		/* kill() */
		struct {
			compat_pid_t _pid;		/* sender's pid */
			unsigned int _uid;		/* sender's uid */
		} _kill;

		/* POSIX.1b timers */
		struct {
			compat_timer_t _tid;			/* timer id */
			int _overrun;			/* overrun count */
			compat_sigval_t _sigval;		/* same as below */
			int _sys_private;		/* not to be passed to user */
		} _timer;

		/* POSIX.1b signals */
		struct {
			compat_pid_t _pid;		/* sender's pid */
			unsigned int _uid;		/* sender's uid */
			compat_sigval_t _sigval;
		} _rt;

		/* SIGCHLD */
		struct {
			compat_pid_t _pid;		/* which child */
			unsigned int _uid;		/* sender's uid */
			int _status;			/* exit code */
			compat_clock_t _utime;
			compat_clock_t _stime;
		} _sigchld;

		/* SIGILL, SIGFPE, SIGSEGV, SIGBUS, SIGEMT */
		struct {
			u32 _addr; /* faulting insn/memory ref. */
			int _trapno;
		} _sigfault;

		/* SIGPOLL */
		struct {
			int _band;	/* POLL_IN, POLL_OUT, POLL_MSG */
			int _fd;
		} _sigpoll;
	} _sifields;
}compat_siginfo_t;

struct rt_signal_frame32 {
	struct sparc_stackf32	ss;
	compat_siginfo_t	info;
	struct pt_regs32	regs;
	compat_sigset_t		mask;
	/* __siginfo_fpu32_t * */ u32 fpu_save;
	unsigned int		insns[2];
	stack_t32		stack;
	unsigned int		extra_size; /* Should be sizeof(siginfo_extra_v8plus_t) */
	/* Only valid if (regs.psr & (PSR_VERS|PSR_IMPL)) == PSR_V8PLUS */
	siginfo_extra_v8plus_t	v8plus;
	__siginfo_fpu_t		fpu_state;
};

/* Align macros */
#define SF_ALIGNEDSZ  (((sizeof(struct signal_sframe32) + 7) & (~7)))
#define NF_ALIGNEDSZ  (((sizeof(struct new_signal_frame32) + 7) & (~7)))
#define RT_ALIGNEDSZ  (((sizeof(struct rt_signal_frame32) + 7) & (~7)))

int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
{
	int err;

	if (!access_ok(VERIFY_WRITE, to, sizeof(compat_siginfo_t)))
		return -EFAULT;

	/* If you change siginfo_t structure, please be sure
	   this code is fixed accordingly.
	   It should never copy any pad contained in the structure
	   to avoid security leaks, but must copy the generic
	   3 ints plus the relevant union member.
	   This routine must convert siginfo from 64bit to 32bit as well
	   at the same time.  */
	err = __put_user(from->si_signo, &to->si_signo);
	err |= __put_user(from->si_errno, &to->si_errno);
	err |= __put_user((short)from->si_code, &to->si_code);
	if (from->si_code < 0)
		err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
	else {
		switch (from->si_code >> 16) {
		case __SI_TIMER >> 16:
			err |= __put_user(from->si_tid, &to->si_tid);
			err |= __put_user(from->si_overrun, &to->si_overrun);
			err |= __put_user(from->si_int, &to->si_int);
			break;
		case __SI_CHLD >> 16:
			err |= __put_user(from->si_utime, &to->si_utime);
			err |= __put_user(from->si_stime, &to->si_stime);
			err |= __put_user(from->si_status, &to->si_status);
		default:
			err |= __put_user(from->si_pid, &to->si_pid);
			err |= __put_user(from->si_uid, &to->si_uid);
			break;
		case __SI_FAULT >> 16:
			err |= __put_user(from->si_trapno, &to->si_trapno);
			err |= __put_user((unsigned long)from->si_addr, &to->si_addr);
			break;
		case __SI_POLL >> 16:
			err |= __put_user(from->si_band, &to->si_band);
			err |= __put_user(from->si_fd, &to->si_fd);
			break;
		case __SI_RT >> 16: /* This is not generated by the kernel as of now.  */
		case __SI_MESGQ >> 16:
			err |= __put_user(from->si_pid, &to->si_pid);
			err |= __put_user(from->si_uid, &to->si_uid);
			err |= __put_user(from->si_int, &to->si_int);
			break;
		}
	}
	return err;
}

/* CAUTION: This is just a very minimalist implementation for the
 *          sake of compat_sys_rt_sigqueueinfo()
 */
int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
{
	if (!access_ok(VERIFY_WRITE, from, sizeof(compat_siginfo_t)))
		return -EFAULT;

	if (copy_from_user(to, from, 3*sizeof(int)) ||
	    copy_from_user(to->_sifields._pad, from->_sifields._pad,
			   SI_PAD_SIZE))
		return -EFAULT;

	return 0;
}

static int restore_fpu_state32(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
{
	unsigned long *fpregs = current_thread_info()->fpregs;
	unsigned long fprs;
	int err;
	
	err = __get_user(fprs, &fpu->si_fprs);
	fprs_write(0);
	regs->tstate &= ~TSTATE_PEF;
	if (fprs & FPRS_DL)
		err |= copy_from_user(fpregs, &fpu->si_float_regs[0], (sizeof(unsigned int) * 32));
	if (fprs & FPRS_DU)
		err |= copy_from_user(fpregs+16, &fpu->si_float_regs[32], (sizeof(unsigned int) * 32));
	err |= __get_user(current_thread_info()->xfsr[0], &fpu->si_fsr);
	err |= __get_user(current_thread_info()->gsr[0], &fpu->si_gsr);
	current_thread_info()->fpsaved[0] |= fprs;
	return err;
}

void do_new_sigreturn32(struct pt_regs *regs)
{
	struct new_signal_frame32 __user *sf;
	unsigned int psr;
	unsigned pc, npc, fpu_save;
	sigset_t set;
	unsigned seta[_COMPAT_NSIG_WORDS];
	int err, i;
	
	regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
	sf = (struct new_signal_frame32 __user *) regs->u_regs[UREG_FP];

	/* 1. Make sure we are not getting garbage from the user */
	if (!access_ok(VERIFY_READ, sf, sizeof(*sf)) ||
	    (((unsigned long) sf) & 3))
		goto segv;

	get_user(pc, &sf->info.si_regs.pc);
	__get_user(npc, &sf->info.si_regs.npc);

	if ((pc | npc) & 3)
		goto segv;

	if (test_thread_flag(TIF_32BIT)) {
		pc &= 0xffffffff;
		npc &= 0xffffffff;
	}
	regs->tpc = pc;
	regs->tnpc = npc;

	/* 2. Restore the state */
	err = __get_user(regs->y, &sf->info.si_regs.y);
	err |= __get_user(psr, &sf->info.si_regs.psr);

	for (i = UREG_G1; i <= UREG_I7; i++)
		err |= __get_user(regs->u_regs[i], &sf->info.si_regs.u_regs[i]);
	if ((psr & (PSR_VERS|PSR_IMPL)) == PSR_V8PLUS) {
		err |= __get_user(i, &sf->v8plus.g_upper[0]);
		if (i == SIGINFO_EXTRA_V8PLUS_MAGIC) {
			unsigned long asi;

			for (i = UREG_G1; i <= UREG_I7; i++)
				err |= __get_user(((u32 *)regs->u_regs)[2*i], &sf->v8plus.g_upper[i]);
			err |= __get_user(asi, &sf->v8plus.asi);
			regs->tstate &= ~TSTATE_ASI;
			regs->tstate |= ((asi & 0xffUL) << 24UL);
		}
	}

	/* User can only change condition codes in %tstate. */
	regs->tstate &= ~(TSTATE_ICC|TSTATE_XCC);
	regs->tstate |= psr_to_tstate_icc(psr);

	err |= __get_user(fpu_save, &sf->fpu_save);
	if (fpu_save)
		err |= restore_fpu_state32(regs, &sf->fpu_state);
	err |= __get_user(seta[0], &sf->info.si_mask);
	err |= copy_from_user(seta+1, &sf->extramask,
			      (_COMPAT_NSIG_WORDS - 1) * sizeof(unsigned int));
	if (err)
	    	goto segv;
	switch (_NSIG_WORDS) {
		case 4: set.sig[3] = seta[6] + (((long)seta[7]) << 32);
		case 3: set.sig[2] = seta[4] + (((long)seta[5]) << 32);
		case 2: set.sig[1] = seta[2] + (((long)seta[3]) << 32);
		case 1: set.sig[0] = seta[0] + (((long)seta[1]) << 32);
	}
	sigdelsetmask(&set, ~_BLOCKABLE);
	spin_lock_irq(&current->sighand->siglock);
	current->blocked = set;
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);
	return;

segv:
	force_sig(SIGSEGV, current);
}

asmlinkage void do_sigreturn32(struct pt_regs *regs)
{
	struct sigcontext32 __user *scptr;
	unsigned int pc, npc, psr;
	sigset_t set;
	unsigned int seta[_COMPAT_NSIG_WORDS];
	int err;

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

	synchronize_user_stack();
	if (test_thread_flag(TIF_NEWSIGNALS)) {
		do_new_sigreturn32(regs);
		return;
	}

	scptr = (struct sigcontext32 __user *)
		(regs->u_regs[UREG_I0] & 0x00000000ffffffffUL);
	/* Check sanity of the user arg. */
	if (!access_ok(VERIFY_READ, scptr, sizeof(struct sigcontext32)) ||
	    (((unsigned long) scptr) & 3))
		goto segv;

	err = __get_user(pc, &scptr->sigc_pc);
	err |= __get_user(npc, &scptr->sigc_npc);

	if ((pc | npc) & 3)
		goto segv; /* Nice try. */

	err |= __get_user(seta[0], &scptr->sigc_mask);
	/* Note that scptr + 1 points to extramask */
	err |= copy_from_user(seta+1, scptr + 1,
			      (_COMPAT_NSIG_WORDS - 1) * sizeof(unsigned int));
	if (err)
	    	goto segv;
	switch (_NSIG_WORDS) {
		case 4: set.sig[3] = seta[6] + (((long)seta[7]) << 32);
		case 3: set.sig[2] = seta[4] + (((long)seta[5]) << 32);
		case 2: set.sig[1] = seta[2] + (((long)seta[3]) << 32);
		case 1: set.sig[0] = seta[0] + (((long)seta[1]) << 32);
	}
	sigdelsetmask(&set, ~_BLOCKABLE);
	spin_lock_irq(&current->sighand->siglock);
	current->blocked = set;
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);
	
	if (test_thread_flag(TIF_32BIT)) {
		pc &= 0xffffffff;
		npc &= 0xffffffff;
	}
	regs->tpc = pc;
	regs->tnpc = npc;
	err = __get_user(regs->u_regs[UREG_FP], &scptr->sigc_sp);
	err |= __get_user(regs->u_regs[UREG_I0], &scptr->sigc_o0);
	err |= __get_user(regs->u_regs[UREG_G1], &scptr->sigc_g1);

	/* User can only change condition codes in %tstate. */
	err |= __get_user(psr, &scptr->sigc_psr);
	if (err)
		goto segv;
	regs->tstate &= ~(TSTATE_ICC|TSTATE_XCC);
	regs->tstate |= psr_to_tstate_icc(psr);
	return;

segv:
	force_sig(SIGSEGV, current);
}

asmlinkage void do_rt_sigreturn32(struct pt_regs *regs)
{
	struct rt_signal_frame32 __user *sf;
	unsigned int psr, pc, npc, fpu_save, u_ss_sp;
	mm_segment_t old_fs;
	sigset_t set;
	compat_sigset_t seta;
	stack_t st;
	int err, i;
	
	/* Always make any pending restarted system calls return -EINTR */
	current_thread_info()->restart_block.fn = do_no_restart_syscall;

	synchronize_user_stack();
	regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
	sf = (struct rt_signal_frame32 __user *) regs->u_regs[UREG_FP];

	/* 1. Make sure we are not getting garbage from the user */
	if (!access_ok(VERIFY_READ, sf, sizeof(*sf)) ||
	    (((unsigned long) sf) & 3))
		goto segv;

	get_user(pc, &sf->regs.pc);
	__get_user(npc, &sf->regs.npc);

	if ((pc | npc) & 3)
		goto segv;

	if (test_thread_flag(TIF_32BIT)) {
		pc &= 0xffffffff;
		npc &= 0xffffffff;
	}
	regs->tpc = pc;
	regs->tnpc = npc;

	/* 2. Restore the state */
	err = __get_user(regs->y, &sf->regs.y);
	err |= __get_user(psr, &sf->regs.psr);
	
	for (i = UREG_G1; i <= UREG_I7; i++)
		err |= __get_user(regs->u_regs[i], &sf->regs.u_regs[i]);
	if ((psr & (PSR_VERS|PSR_IMPL)) == PSR_V8PLUS) {
		err |= __get_user(i, &sf->v8plus.g_upper[0]);
		if (i == SIGINFO_EXTRA_V8PLUS_MAGIC) {
			unsigned long asi;

			for (i = UREG_G1; i <= UREG_I7; i++)
				err |= __get_user(((u32 *)regs->u_regs)[2*i], &sf->v8plus.g_upper[i]);
			err |= __get_user(asi, &sf->v8plus.asi);
			regs->tstate &= ~TSTATE_ASI;
			regs->tstate |= ((asi & 0xffUL) << 24UL);
		}
	}

	/* User can only change condition codes in %tstate. */
	regs->tstate &= ~(TSTATE_ICC|TSTATE_XCC);
	regs->tstate |= psr_to_tstate_icc(psr);

	err |= __get_user(fpu_save, &sf->fpu_save);
	if (fpu_save)
		err |= restore_fpu_state32(regs, &sf->fpu_state);
	err |= copy_from_user(&seta, &sf->mask, sizeof(compat_sigset_t));
	err |= __get_user(u_ss_sp, &sf->stack.ss_sp);
	st.ss_sp = compat_ptr(u_ss_sp);
	err |= __get_user(st.ss_flags, &sf->stack.ss_flags);
	err |= __get_user(st.ss_size, &sf->stack.ss_size);
	if (err)
		goto segv;
		
	/* It is more difficult to avoid calling this function than to
	   call it and ignore errors.  */
	old_fs = get_fs();
	set_fs(KERNEL_DS);
	do_sigaltstack((stack_t __user *) &st, NULL, (unsigned long)sf);
	set_fs(old_fs);
	
	switch (_NSIG_WORDS) {
		case 4: set.sig[3] = seta.sig[6] + (((long)seta.sig[7]) << 32);
		case 3: set.sig[2] = seta.sig[4] + (((long)seta.sig[5]) << 32);
		case 2: set.sig[1] = seta.sig[2] + (((long)seta.sig[3]) << 32);
		case 1: set.sig[0] = seta.sig[0] + (((long)seta.sig[1]) << 32);
	}
	sigdelsetmask(&set, ~_BLOCKABLE);
	spin_lock_irq(&current->sighand->siglock);
	current->blocked = set;
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);
	return;
segv:
	force_sig(SIGSEGV, current);
}

/* Checks if the fp is valid */
static int invalid_frame_pointer(void __user *fp, int fplen)
{
	if ((((unsigned long) fp) & 7) || ((unsigned long)fp) > 0x100000000ULL - fplen)
		return 1;
	return 0;
}

static void __user *get_sigframe(struct sigaction *sa, struct pt_regs *regs, unsigned long framesize)
{
	unsigned long sp;
	
	regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
	sp = regs->u_regs[UREG_FP];
	
	/* This is the X/Open sanctioned signal stack switching.  */
	if (sa->sa_flags & SA_ONSTACK) {
		if (!on_sig_stack(sp) && !((current->sas_ss_sp + current->sas_ss_size) & 7))
			sp = current->sas_ss_sp + current->sas_ss_size;
	}
	return (void __user *)(sp - framesize);
}

static void
setup_frame32(struct sigaction *sa, struct pt_regs *regs, int signr, sigset_t *oldset, siginfo_t *info)
{
	struct signal_sframe32 __user *sframep;
	struct sigcontext32 __user *sc;
	unsigned int seta[_COMPAT_NSIG_WORDS];
	int err = 0;
	void __user *sig_address;
	int sig_code;
	unsigned long pc = regs->tpc;
	unsigned long npc = regs->tnpc;
	unsigned int psr;

	if (test_thread_flag(TIF_32BIT)) {
		pc &= 0xffffffff;
		npc &= 0xffffffff;
	}

	synchronize_user_stack();
	save_and_clear_fpu();

	sframep = (struct signal_sframe32 __user *)
		get_sigframe(sa, regs, SF_ALIGNEDSZ);
	if (invalid_frame_pointer(sframep, sizeof(*sframep))){
		/* Don't change signal code and address, so that
		 * post mortem debuggers can have a look.
		 */
		do_exit(SIGILL);
	}

	sc = &sframep->sig_context;

	/* We've already made sure frame pointer isn't in kernel space... */
	err = __put_user((sas_ss_flags(regs->u_regs[UREG_FP]) == SS_ONSTACK),
			 &sc->sigc_onstack);
	
	switch (_NSIG_WORDS) {
	case 4: seta[7] = (oldset->sig[3] >> 32);
	        seta[6] = oldset->sig[3];
	case 3: seta[5] = (oldset->sig[2] >> 32);
	        seta[4] = oldset->sig[2];
	case 2: seta[3] = (oldset->sig[1] >> 32);
	        seta[2] = oldset->sig[1];
	case 1: seta[1] = (oldset->sig[0] >> 32);
	        seta[0] = oldset->sig[0];
	}
	err |= __put_user(seta[0], &sc->sigc_mask);
	err |= __copy_to_user(sframep->extramask, seta + 1,
			      (_COMPAT_NSIG_WORDS - 1) * sizeof(unsigned int));
	err |= __put_user(regs->u_regs[UREG_FP], &sc->sigc_sp);
	err |= __put_user(pc, &sc->sigc_pc);
	err |= __put_user(npc, &sc->sigc_npc);
	psr = tstate_to_psr(regs->tstate);
	if (current_thread_info()->fpsaved[0] & FPRS_FEF)
		psr |= PSR_EF;
	err |= __put_user(psr, &sc->sigc_psr);
	err |= __put_user(regs->u_regs[UREG_G1], &sc->sigc_g1);
	err |= __put_user(regs->u_regs[UREG_I0], &sc->sigc_o0);
	err |= __put_user(get_thread_wsaved(), &sc->sigc_oswins);

	err |= copy_in_user((u32 __user *)sframep,
			    (u32 __user *)(regs->u_regs[UREG_FP]),
			    sizeof(struct reg_window32));
		       
	set_thread_wsaved(0); /* So process is allowed to execute. */
	err |= __put_user(signr, &sframep->sig_num);
	sig_address = NULL;
	sig_code = 0;
	if (SI_FROMKERNEL (info) && (info->si_code & __SI_MASK) == __SI_FAULT) {
		sig_address = info->si_addr;
		switch (signr) {
		case SIGSEGV:
			switch (info->si_code) {
			case SEGV_MAPERR: sig_code = SUBSIG_NOMAPPING; break;
			default: sig_code = SUBSIG_PROTECTION; break;
			}
			break;
		case SIGILL:
			switch (info->si_code) {
			case ILL_ILLOPC: sig_code = SUBSIG_ILLINST; break;
			case ILL_PRVOPC: sig_code = SUBSIG_PRIVINST; break;
			case ILL_ILLTRP: sig_code = SUBSIG_BADTRAP(info->si_trapno); break;
			default: sig_code = SUBSIG_STACK; break;
			}
			break;
		case SIGFPE:
			switch (info->si_code) {
			case FPE_INTDIV: sig_code = SUBSIG_IDIVZERO; break;
			case FPE_INTOVF: sig_code = SUBSIG_FPINTOVFL; break;
			case FPE_FLTDIV: sig_code = SUBSIG_FPDIVZERO; break;
			case FPE_FLTOVF: sig_code = SUBSIG_FPOVFLOW; break;
			case FPE_FLTUND: sig_code = SUBSIG_FPUNFLOW; break;
			case FPE_FLTRES: sig_code = SUBSIG_FPINEXACT; break;
			case FPE_FLTINV: sig_code = SUBSIG_FPOPERROR; break;
			default: sig_code = SUBSIG_FPERROR; break;
			}
			break;
		case SIGBUS:
			switch (info->si_code) {
			case BUS_ADRALN: sig_code = SUBSIG_ALIGNMENT; break;
			case BUS_ADRERR: sig_code = SUBSIG_MISCERROR; break;
			default: sig_code = SUBSIG_BUSTIMEOUT; break;
			}
			break;
		case SIGEMT:
			switch (info->si_code) {
			case EMT_TAGOVF: sig_code = SUBSIG_TAG; break;
			}
			break;
		case SIGSYS:
			if (info->si_code == (__SI_FAULT|0x100)) {
				/* See sys_sunos32.c */
				sig_code = info->si_trapno;
				break;
			}
		default:
			sig_address = NULL;
		}
	}
	err |= __put_user(ptr_to_compat(sig_address), &sframep->sig_address);
	err |= __put_user(sig_code, &sframep->sig_code);
	err |= __put_user(ptr_to_compat(sc), &sframep->sig_scptr);
	if (err)
		goto sigsegv;

	regs->u_regs[UREG_FP] = (unsigned long) sframep;
	regs->tpc = (unsigned long) sa->sa_handler;
	regs->tnpc = (regs->tpc + 4);
	if (test_thread_flag(TIF_32BIT)) {
		regs->tpc &= 0xffffffff;
		regs->tnpc &= 0xffffffff;
	}
	return;

sigsegv:
	force_sigsegv(signr, current);
}


static int save_fpu_state32(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
{
	unsigned long *fpregs = current_thread_info()->fpregs;
	unsigned long fprs;
	int err = 0;
	
	fprs = current_thread_info()->fpsaved[0];
	if (fprs & FPRS_DL)
		err |= copy_to_user(&fpu->si_float_regs[0], fpregs,
				    (sizeof(unsigned int) * 32));
	if (fprs & FPRS_DU)
		err |= copy_to_user(&fpu->si_float_regs[32], fpregs+16,
				    (sizeof(unsigned int) * 32));
	err |= __put_user(current_thread_info()->xfsr[0], &fpu->si_fsr);
	err |= __put_user(current_thread_info()->gsr[0], &fpu->si_gsr);
	err |= __put_user(fprs, &fpu->si_fprs);

	return err;
}

static void new_setup_frame32(struct k_sigaction *ka, struct pt_regs *regs,
			      int signo, sigset_t *oldset)
{
	struct new_signal_frame32 __user *sf;
	int sigframe_size;
	u32 psr;
	int i, err;
	unsigned int seta[_COMPAT_NSIG_WORDS];

	/* 1. Make sure everything is clean */
	synchronize_user_stack();
	save_and_clear_fpu();
	
	sigframe_size = NF_ALIGNEDSZ;
	if (!(current_thread_info()->fpsaved[0] & FPRS_FEF))
		sigframe_size -= sizeof(__siginfo_fpu_t);

	sf = (struct new_signal_frame32 __user *)
		get_sigframe(&ka->sa, regs, sigframe_size);
	
	if (invalid_frame_pointer(sf, sigframe_size))
		goto sigill;

	if (get_thread_wsaved() != 0)
		goto sigill;

	/* 2. Save the current process state */
	if (test_thread_flag(TIF_32BIT)) {
		regs->tpc &= 0xffffffff;
		regs->tnpc &= 0xffffffff;
	}
	err  = put_user(regs->tpc, &sf->info.si_regs.pc);
	err |= __put_user(regs->tnpc, &sf->info.si_regs.npc);
	err |= __put_user(regs->y, &sf->info.si_regs.y);
	psr = tstate_to_psr(regs->tstate);
	if (current_thread_info()->fpsaved[0] & FPRS_FEF)
		psr |= PSR_EF;
	err |= __put_user(psr, &sf->info.si_regs.psr);
	for (i = 0; i < 16; i++)
		err |= __put_user(regs->u_regs[i], &sf->info.si_regs.u_regs[i]);
	err |= __put_user(sizeof(siginfo_extra_v8plus_t), &sf->extra_size);
	err |= __put_user(SIGINFO_EXTRA_V8PLUS_MAGIC, &sf->v8plus.g_upper[0]);
	for (i = 1; i < 16; i++)
		err |= __put_user(((u32 *)regs->u_regs)[2*i],
				  &sf->v8plus.g_upper[i]);
	err |= __put_user((regs->tstate & TSTATE_ASI) >> 24UL,
			  &sf->v8plus.asi);

	if (psr & PSR_EF) {
		err |= save_fpu_state32(regs, &sf->fpu_state);
		err |= __put_user((u64)&sf->fpu_state, &sf->fpu_save);
	} else {
		err |= __put_user(0, &sf->fpu_save);
	}

	switch (_NSIG_WORDS) {
	case 4: seta[7] = (oldset->sig[3] >> 32);
	        seta[6] = oldset->sig[3];
	case 3: seta[5] = (oldset->sig[2] >> 32);
	        seta[4] = oldset->sig[2];
	case 2: seta[3] = (oldset->sig[1] >> 32);
	        seta[2] = oldset->sig[1];
	case 1: seta[1] = (oldset->sig[0] >> 32);
	        seta[0] = oldset->sig[0];
	}
	err |= __put_user(seta[0], &sf->info.si_mask);
	err |= __copy_to_user(sf->extramask, seta + 1,
			      (_COMPAT_NSIG_WORDS - 1) * sizeof(unsigned int));

	err |= copy_in_user((u32 __user *)sf,
			    (u32 __user *)(regs->u_regs[UREG_FP]),
			    sizeof(struct reg_window32));
	
	if (err)
		goto sigsegv;

	/* 3. signal handler back-trampoline and parameters */
	regs->u_regs[UREG_FP] = (unsigned long) sf;
	regs->u_regs[UREG_I0] = signo;
	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
	regs->u_regs[UREG_I2] = (unsigned long) &sf->info;

	/* 4. signal handler */
	regs->tpc = (unsigned long) ka->sa.sa_handler;
	regs->tnpc = (regs->tpc + 4);
	if (test_thread_flag(TIF_32BIT)) {
		regs->tpc &= 0xffffffff;
		regs->tnpc &= 0xffffffff;
	}

	/* 5. return to kernel instructions */
	if (ka->ka_restorer) {
		regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
	} else {
		/* Flush instruction space. */
		unsigned long address = ((unsigned long)&(sf->insns[0]));
		pgd_t *pgdp = pgd_offset(current->mm, address);
		pud_t *pudp = pud_offset(pgdp, address);
		pmd_t *pmdp = pmd_offset(pudp, address);
		pte_t *ptep;
		pte_t pte;

		regs->u_regs[UREG_I7] = (unsigned long) (&(sf->insns[0]) - 2);
	
		err  = __put_user(0x821020d8, &sf->insns[0]); /*mov __NR_sigreturn, %g1*/
		err |= __put_user(0x91d02010, &sf->insns[1]); /*t 0x10*/
		if (err)
			goto sigsegv;

		preempt_disable();
		ptep = pte_offset_map(pmdp, address);
		pte = *ptep;
		if (pte_present(pte)) {
			unsigned long page = (unsigned long)
				page_address(pte_page(pte));

			wmb();
			__asm__ __volatile__("flush	%0 + %1"
					     : /* no outputs */
					     : "r" (page),
					       "r" (address & (PAGE_SIZE - 1))
					     : "memory");
		}
		pte_unmap(ptep);
		preempt_enable();
	}
	return;

sigill:
	do_exit(SIGILL);
sigsegv:
	force_sigsegv(signo, current);
}

/* Setup a Solaris stack frame */
static void
setup_svr4_frame32(struct sigaction *sa, unsigned long pc, unsigned long npc,
		   struct pt_regs *regs, int signr, sigset_t *oldset)
{
	svr4_signal_frame_t __user *sfp;
	svr4_gregset_t  __user *gr;
	svr4_siginfo_t  __user *si;
	svr4_mcontext_t __user *mc;
	svr4_gwindows_t __user *gw;
	svr4_ucontext_t __user *uc;
	svr4_sigset_t setv;
	unsigned int psr;
	int i, err;

	synchronize_user_stack();
	save_and_clear_fpu();
	
	regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
	sfp = (svr4_signal_frame_t __user *)
		get_sigframe(sa, regs,
			     sizeof(struct reg_window32) + SVR4_SF_ALIGNED);

	if (invalid_frame_pointer(sfp, sizeof(*sfp)))
		do_exit(SIGILL);

	/* Start with a clean frame pointer and fill it */
	err = clear_user(sfp, sizeof(*sfp));

	/* Setup convenience variables */
	si = &sfp->si;
	uc = &sfp->uc;
	gw = &sfp->gw;
	mc = &uc->mcontext;
	gr = &mc->greg;
	
	/* FIXME: where am I supposed to put this?
	 * sc->sigc_onstack = old_status;
	 * anyways, it does not look like it is used for anything at all.
	 */
	setv.sigbits[0] = oldset->sig[0];
	setv.sigbits[1] = (oldset->sig[0] >> 32);
	if (_NSIG_WORDS >= 2) {
		setv.sigbits[2] = oldset->sig[1];
		setv.sigbits[3] = (oldset->sig[1] >> 32);
		err |= __copy_to_user(&uc->sigmask, &setv, sizeof(svr4_sigset_t));
	} else
		err |= __copy_to_user(&uc->sigmask, &setv,
				      2 * sizeof(unsigned int));
	
	/* Store registers */
	if (test_thread_flag(TIF_32BIT)) {
		regs->tpc &= 0xffffffff;
		regs->tnpc &= 0xffffffff;
	}
	err |= __put_user(regs->tpc, &((*gr)[SVR4_PC]));
	err |= __put_user(regs->tnpc, &((*gr)[SVR4_NPC]));
	psr = tstate_to_psr(regs->tstate);
	if (current_thread_info()->fpsaved[0] & FPRS_FEF)
		psr |= PSR_EF;
	err |= __put_user(psr, &((*gr)[SVR4_PSR]));
	err |= __put_user(regs->y, &((*gr)[SVR4_Y]));
	
	/* Copy g[1..7] and o[0..7] registers */
	for (i = 0; i < 7; i++)
		err |= __put_user(regs->u_regs[UREG_G1+i], (&(*gr)[SVR4_G1])+i);
	for (i = 0; i < 8; i++)
		err |= __put_user(regs->u_regs[UREG_I0+i], (&(*gr)[SVR4_O0])+i);

	/* Setup sigaltstack */
	err |= __put_user(current->sas_ss_sp, &uc->stack.sp);
	err |= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &uc->stack.flags);
	err |= __put_user(current->sas_ss_size, &uc->stack.size);

	/* Save the currently window file: */

	/* 1. Link sfp->uc->gwins to our windows */
	err |= __put_user(ptr_to_compat(gw), &mc->gwin);
	    
	/* 2. Number of windows to restore at setcontext (): */
	err |= __put_user(get_thread_wsaved(), &gw->count);

	/* 3. We just pay attention to the gw->count field on setcontext */
	set_thread_wsaved(0); /* So process is allowed to execute. */

	/* Setup the signal information.  Solaris expects a bunch of
	 * information to be passed to the signal handler, we don't provide
	 * that much currently, should use siginfo.
	 */
	err |= __put_user(signr, &si->siginfo.signo);
	err |= __put_user(SVR4_SINOINFO, &si->siginfo.code);
	if (err)
		goto sigsegv;

	regs->u_regs[UREG_FP] = (unsigned long) sfp;
	regs->tpc = (unsigned long) sa->sa_handler;
	regs->tnpc = (regs->tpc + 4);
	if (test_thread_flag(TIF_32BIT)) {
		regs->tpc &= 0xffffffff;
		regs->tnpc &= 0xffffffff;
	}

	/* Arguments passed to signal handler */
	if (regs->u_regs[14]){
		struct reg_window32 __user *rw = (struct reg_window32 __user *)
			(regs->u_regs[14] & 0x00000000ffffffffUL);

		err |= __put_user(signr, &rw->ins[0]);
		err |= __put_user((u64)si, &rw->ins[1]);
		err |= __put_user((u64)uc, &rw->ins[2]);
		err |= __put_user((u64)sfp, &rw->ins[6]);	/* frame pointer */
		if (err)
			goto sigsegv;

		regs->u_regs[UREG_I0] = signr;
		regs->u_regs[UREG_I1] = (u32)(u64) si;
		regs->u_regs[UREG_I2] = (u32)(u64) uc;
	}
	return;

sigsegv:
	force_sigsegv(signr, current);
}

asmlinkage int
svr4_getcontext(svr4_ucontext_t __user *uc, struct pt_regs *regs)
{
	svr4_gregset_t  __user *gr;
	svr4_mcontext_t __user *mc;
	svr4_sigset_t setv;
	int i, err;
	u32 psr;

	synchronize_user_stack();
	save_and_clear_fpu();
	
	if (get_thread_wsaved())
		do_exit(SIGSEGV);

	err = clear_user(uc, sizeof(*uc));

	/* Setup convenience variables */
	mc = &uc->mcontext;
	gr = &mc->greg;

	setv.sigbits[0] = current->blocked.sig[0];
	setv.sigbits[1] = (current->blocked.sig[0] >> 32);
	if (_NSIG_WORDS >= 2) {
		setv.sigbits[2] = current->blocked.sig[1];
		setv.sigbits[3] = (current->blocked.sig[1] >> 32);
		err |= __copy_to_user(&uc->sigmask, &setv, sizeof(svr4_sigset_t));
	} else
		err |= __copy_to_user(&uc->sigmask, &setv, 2 * sizeof(unsigned));

	/* Store registers */
	if (test_thread_flag(TIF_32BIT)) {
		regs->tpc &= 0xffffffff;
		regs->tnpc &= 0xffffffff;
	}
	err |= __put_user(regs->tpc, &uc->mcontext.greg[SVR4_PC]);
	err |= __put_user(regs->tnpc, &uc->mcontext.greg[SVR4_NPC]);

	psr = tstate_to_psr(regs->tstate) & ~PSR_EF;		   
	if (current_thread_info()->fpsaved[0] & FPRS_FEF)
		psr |= PSR_EF;
	err |= __put_user(psr, &uc->mcontext.greg[SVR4_PSR]);

	err |= __put_user(regs->y, &uc->mcontext.greg[SVR4_Y]);
	
	/* Copy g[1..7] and o[0..7] registers */
	for (i = 0; i < 7; i++)
		err |= __put_user(regs->u_regs[UREG_G1+i], (&(*gr)[SVR4_G1])+i);
	for (i = 0; i < 8; i++)
		err |= __put_user(regs->u_regs[UREG_I0+i], (&(*gr)[SVR4_O0])+i);

	/* Setup sigaltstack */
	err |= __put_user(current->sas_ss_sp, &uc->stack.sp);
	err |= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &uc->stack.flags);
	err |= __put_user(current->sas_ss_size, &uc->stack.size);

	/* The register file is not saved
	 * we have already stuffed all of it with sync_user_stack
	 */
	return (err ? -EFAULT : 0);
}


/* Set the context for a svr4 application, this is Solaris way to sigreturn */
asmlinkage int svr4_setcontext(svr4_ucontext_t __user *c, struct pt_regs *regs)
{
	svr4_gregset_t  __user *gr;
	mm_segment_t old_fs;
	u32 pc, npc, psr, u_ss_sp;
	sigset_t set;
	svr4_sigset_t setv;
	int i, err;
	stack_t st;
	
	/* Fixme: restore windows, or is this already taken care of in
	 * svr4_setup_frame when sync_user_windows is done?
	 */
	flush_user_windows();
	
	if (get_thread_wsaved())
		goto sigsegv;

	if (((unsigned long) c) & 3){
		printk("Unaligned structure passed\n");
		goto sigsegv;
	}

	if (!__access_ok(c, sizeof(*c))) {
		/* Miguel, add nice debugging msg _here_. ;-) */
		goto sigsegv;
	}

	/* Check for valid PC and nPC */
	gr = &c->mcontext.greg;
	err = __get_user(pc, &((*gr)[SVR4_PC]));
	err |= __get_user(npc, &((*gr)[SVR4_NPC]));
	if ((pc | npc) & 3)
		goto sigsegv;
	
	/* Retrieve information from passed ucontext */
	/* note that nPC is ored a 1, this is used to inform entry.S */
	/* that we don't want it to mess with our PC and nPC */
	
	err |= copy_from_user(&setv, &c->sigmask, sizeof(svr4_sigset_t));
	set.sig[0] = setv.sigbits[0] | (((long)setv.sigbits[1]) << 32);
	if (_NSIG_WORDS >= 2)
		set.sig[1] = setv.sigbits[2] | (((long)setv.sigbits[3]) << 32);
	
	err |= __get_user(u_ss_sp, &c->stack.sp);
	st.ss_sp = compat_ptr(u_ss_sp);
	err |= __get_user(st.ss_flags, &c->stack.flags);
	err |= __get_user(st.ss_size, &c->stack.size);
	if (err)
		goto sigsegv;
		
	/* It is more difficult to avoid calling this function than to
	   call it and ignore errors.  */
	old_fs = get_fs();
	set_fs(KERNEL_DS);
	do_sigaltstack((stack_t __user *) &st, NULL, regs->u_regs[UREG_I6]);
	set_fs(old_fs);
	
	sigdelsetmask(&set, ~_BLOCKABLE);
	spin_lock_irq(&current->sighand->siglock);
	current->blocked = set;
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);
	regs->tpc = pc;
	regs->tnpc = npc | 1;
	if (test_thread_flag(TIF_32BIT)) {
		regs->tpc &= 0xffffffff;
		regs->tnpc &= 0xffffffff;
	}
	err |= __get_user(regs->y, &((*gr)[SVR4_Y]));
	err |= __get_user(psr, &((*gr)[SVR4_PSR]));
	regs->tstate &= ~(TSTATE_ICC|TSTATE_XCC);
	regs->tstate |= psr_to_tstate_icc(psr);

	/* Restore g[1..7] and o[0..7] registers */
	for (i = 0; i < 7; i++)
		err |= __get_user(regs->u_regs[UREG_G1+i], (&(*gr)[SVR4_G1])+i);
	for (i = 0; i < 8; i++)
		err |= __get_user(regs->u_regs[UREG_I0+i], (&(*gr)[SVR4_O0])+i);
	if (err)
		goto sigsegv;

	return -EINTR;
sigsegv:
	return -EFAULT;
}

static void setup_rt_frame32(struct k_sigaction *ka, struct pt_regs *regs,
			     unsigned long signr, sigset_t *oldset,
			     siginfo_t *info)
{
	struct rt_signal_frame32 __user *sf;
	int sigframe_size;
	u32 psr;
	int i, err;
	compat_sigset_t seta;

	/* 1. Make sure everything is clean */
	synchronize_user_stack();
	save_and_clear_fpu();
	
	sigframe_size = RT_ALIGNEDSZ;
	if (!(current_thread_info()->fpsaved[0] & FPRS_FEF))
		sigframe_size -= sizeof(__siginfo_fpu_t);

	sf = (struct rt_signal_frame32 __user *)
		get_sigframe(&ka->sa, regs, sigframe_size);
	
	if (invalid_frame_pointer(sf, sigframe_size))
		goto sigill;

	if (get_thread_wsaved() != 0)
		goto sigill;

	/* 2. Save the current process state */
	if (test_thread_flag(TIF_32BIT)) {
		regs->tpc &= 0xffffffff;
		regs->tnpc &= 0xffffffff;
	}
	err  = put_user(regs->tpc, &sf->regs.pc);
	err |= __put_user(regs->tnpc, &sf->regs.npc);
	err |= __put_user(regs->y, &sf->regs.y);
	psr = tstate_to_psr(regs->tstate);
	if (current_thread_info()->fpsaved[0] & FPRS_FEF)
		psr |= PSR_EF;
	err |= __put_user(psr, &sf->regs.psr);
	for (i = 0; i < 16; i++)
		err |= __put_user(regs->u_regs[i], &sf->regs.u_regs[i]);
	err |= __put_user(sizeof(siginfo_extra_v8plus_t), &sf->extra_size);
	err |= __put_user(SIGINFO_EXTRA_V8PLUS_MAGIC, &sf->v8plus.g_upper[0]);
	for (i = 1; i < 16; i++)
		err |= __put_user(((u32 *)regs->u_regs)[2*i],
				  &sf->v8plus.g_upper[i]);
	err |= __put_user((regs->tstate & TSTATE_ASI) >> 24UL,
			  &sf->v8plus.asi);

	if (psr & PSR_EF) {
		err |= save_fpu_state32(regs, &sf->fpu_state);
		err |= __put_user((u64)&sf->fpu_state, &sf->fpu_save);
	} else {
		err |= __put_user(0, &sf->fpu_save);
	}

	/* Update the siginfo structure.  */
	err |= copy_siginfo_to_user32(&sf->info, info);
	
	/* Setup sigaltstack */
	err |= __put_user(current->sas_ss_sp, &sf->stack.ss_sp);
	err |= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &sf->stack.ss_flags);
	err |= __put_user(current->sas_ss_size, &sf->stack.ss_size);

	switch (_NSIG_WORDS) {
	case 4: seta.sig[7] = (oldset->sig[3] >> 32);
		seta.sig[6] = oldset->sig[3];
	case 3: seta.sig[5] = (oldset->sig[2] >> 32);
		seta.sig[4] = oldset->sig[2];
	case 2: seta.sig[3] = (oldset->sig[1] >> 32);
		seta.sig[2] = oldset->sig[1];
	case 1: seta.sig[1] = (oldset->sig[0] >> 32);
		seta.sig[0] = oldset->sig[0];
	}
	err |= __copy_to_user(&sf->mask, &seta, sizeof(compat_sigset_t));

	err |= copy_in_user((u32 __user *)sf,
			    (u32 __user *)(regs->u_regs[UREG_FP]),
			    sizeof(struct reg_window32));
	if (err)
		goto sigsegv;
	
	/* 3. signal handler back-trampoline and parameters */
	regs->u_regs[UREG_FP] = (unsigned long) sf;
	regs->u_regs[UREG_I0] = signr;
	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
	regs->u_regs[UREG_I2] = (unsigned long) &sf->regs;

	/* 4. signal handler */
	regs->tpc = (unsigned long) ka->sa.sa_handler;
	regs->tnpc = (regs->tpc + 4);
	if (test_thread_flag(TIF_32BIT)) {
		regs->tpc &= 0xffffffff;
		regs->tnpc &= 0xffffffff;
	}

	/* 5. return to kernel instructions */
	if (ka->ka_restorer)
		regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
	else {
		/* Flush instruction space. */
		unsigned long address = ((unsigned long)&(sf->insns[0]));
		pgd_t *pgdp = pgd_offset(current->mm, address);
		pud_t *pudp = pud_offset(pgdp, address);
		pmd_t *pmdp = pmd_offset(pudp, address);
		pte_t *ptep;

		regs->u_regs[UREG_I7] = (unsigned long) (&(sf->insns[0]) - 2);
	
		/* mov __NR_rt_sigreturn, %g1 */
		err |= __put_user(0x82102065, &sf->insns[0]);

		/* t 0x10 */
		err |= __put_user(0x91d02010, &sf->insns[1]);
		if (err)
			goto sigsegv;

		preempt_disable();
		ptep = pte_offset_map(pmdp, address);
		if (pte_present(*ptep)) {
			unsigned long page = (unsigned long)
				page_address(pte_page(*ptep));

			wmb();
			__asm__ __volatile__("flush	%0 + %1"
					     : /* no outputs */
					     : "r" (page),
					       "r" (address & (PAGE_SIZE - 1))
					     : "memory");
		}
		pte_unmap(ptep);
		preempt_enable();
	}
	return;

sigill:
	do_exit(SIGILL);
sigsegv:
	force_sigsegv(signr, current);
}

static inline void handle_signal32(unsigned long signr, struct k_sigaction *ka,
				   siginfo_t *info,
				   sigset_t *oldset, struct pt_regs *regs,
				   int svr4_signal)
{
	if (svr4_signal)
		setup_svr4_frame32(&ka->sa, regs->tpc, regs->tnpc,
				   regs, signr, oldset);
	else {
		if (ka->sa.sa_flags & SA_SIGINFO)
			setup_rt_frame32(ka, regs, signr, oldset, info);
		else if (test_thread_flag(TIF_NEWSIGNALS))
			new_setup_frame32(ka, regs, signr, oldset);
		else
			setup_frame32(&ka->sa, regs, signr, oldset, info);
	}
	spin_lock_irq(&current->sighand->siglock);
	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
	if (!(ka->sa.sa_flags & SA_NOMASK))
		sigaddset(&current->blocked,signr);
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);
}

static inline void syscall_restart32(unsigned long orig_i0, struct pt_regs *regs,
				     struct sigaction *sa)
{
	switch (regs->u_regs[UREG_I0]) {
	case ERESTART_RESTARTBLOCK:
	case ERESTARTNOHAND:
	no_system_call_restart:
		regs->u_regs[UREG_I0] = EINTR;
		regs->tstate |= TSTATE_ICARRY;
		break;
	case ERESTARTSYS:
		if (!(sa->sa_flags & SA_RESTART))
			goto no_system_call_restart;
		/* fallthrough */
	case ERESTARTNOINTR:
		regs->u_regs[UREG_I0] = orig_i0;
		regs->tpc -= 4;
		regs->tnpc -= 4;
	}
}

/* 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.
 */
void do_signal32(sigset_t *oldset, struct pt_regs * regs,
		 unsigned long orig_i0, int restart_syscall)
{
	siginfo_t info;
	struct signal_deliver_cookie cookie;
	struct k_sigaction ka;
	int signr;
	int svr4_signal = current->personality == PER_SVR4;
	
	cookie.restart_syscall = restart_syscall;
	cookie.orig_i0 = orig_i0;

	signr = get_signal_to_deliver(&info, &ka, regs, &cookie);
	if (signr > 0) {
		if (cookie.restart_syscall)
			syscall_restart32(orig_i0, regs, &ka.sa);
		handle_signal32(signr, &ka, &info, oldset,
				regs, svr4_signal);

		/* 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);
		return;
	}
	if (cookie.restart_syscall &&
	    (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
	     regs->u_regs[UREG_I0] == ERESTARTSYS ||
	     regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
		/* replay the system call when we are done */
		regs->u_regs[UREG_I0] = cookie.orig_i0;
		regs->tpc -= 4;
		regs->tnpc -= 4;
	}
	if (cookie.restart_syscall &&
	    regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
		regs->u_regs[UREG_G1] = __NR_restart_syscall;
		regs->tpc -= 4;
		regs->tnpc -= 4;
	}

	/* 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);
	}
}

struct sigstack32 {
	u32 the_stack;
	int cur_status;
};

asmlinkage int do_sys32_sigstack(u32 u_ssptr, u32 u_ossptr, unsigned long sp)
{
	struct sigstack32 __user *ssptr =
		(struct sigstack32 __user *)((unsigned long)(u_ssptr));
	struct sigstack32 __user *ossptr =
		(struct sigstack32 __user *)((unsigned long)(u_ossptr));
	int ret = -EFAULT;

	/* First see if old state is wanted. */
	if (ossptr) {
		if (put_user(current->sas_ss_sp + current->sas_ss_size,
			     &ossptr->the_stack) ||
		    __put_user(on_sig_stack(sp), &ossptr->cur_status))
			goto out;
	}
	
	/* Now see if we want to update the new state. */
	if (ssptr) {
		u32 ss_sp;

		if (get_user(ss_sp, &ssptr->the_stack))
			goto out;

		/* If the current stack was set with sigaltstack, don't
		 * swap stacks while we are on it.
		 */
		ret = -EPERM;
		if (current->sas_ss_sp && on_sig_stack(sp))
			goto out;
			
		/* Since we don't know the extent of the stack, and we don't
		 * track onstack-ness, but rather calculate it, we must
		 * presume a size.  Ho hum this interface is lossy.
		 */
		current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ;
		current->sas_ss_size = SIGSTKSZ;
	}
	
	ret = 0;
out:
	return ret;
}

asmlinkage long do_sys32_sigaltstack(u32 ussa, u32 uossa, unsigned long sp)
{
	stack_t uss, uoss;
	u32 u_ss_sp = 0;
	int ret;
	mm_segment_t old_fs;
	stack_t32 __user *uss32 = compat_ptr(ussa);
	stack_t32 __user *uoss32 = compat_ptr(uossa);
	
	if (ussa && (get_user(u_ss_sp, &uss32->ss_sp) ||
		    __get_user(uss.ss_flags, &uss32->ss_flags) ||
		    __get_user(uss.ss_size, &uss32->ss_size)))
		return -EFAULT;
	uss.ss_sp = compat_ptr(u_ss_sp);
	old_fs = get_fs();
	set_fs(KERNEL_DS);
	ret = do_sigaltstack(ussa ? (stack_t __user *) &uss : NULL,
			     uossa ? (stack_t __user *) &uoss : NULL, sp);
	set_fs(old_fs);
	if (!ret && uossa && (put_user(ptr_to_compat(uoss.ss_sp), &uoss32->ss_sp) ||
		    __put_user(uoss.ss_flags, &uoss32->ss_flags) ||
		    __put_user(uoss.ss_size, &uoss32->ss_size)))
		return -EFAULT;
	return ret;
}