/*  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/binfmts.h>
#include <linux/compat.h>
#include <linux/bitops.h>
#include <linux/tracehook.h>

#include <asm/uaccess.h>
#include <asm/ptrace.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)))

/* 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;

struct 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_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_sigreturn32(struct pt_regs *regs)
{
        struct signal_frame32 __user *sf;
        unsigned int psr;
        unsigned pc, npc, fpu_save;
        sigset_t set;
        unsigned seta[_COMPAT_NSIG_WORDS];
        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 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);

        /* Prevent syscall restart.  */
        pt_regs_clear_syscall(regs);

        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_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);

        /* Prevent syscall restart.  */
        pt_regs_clear_syscall(regs);

        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];
        
        /*
         * If we are on the alternate signal stack and would overflow it, don't.
         * Return an always-bogus address instead so we will die with SIGSEGV.
         */
        if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
                return (void __user *) -1L;

        /* This is the X/Open sanctioned signal stack switching.  */
        if (sa->sa_flags & SA_ONSTACK) {
                if (sas_ss_flags(sp) == 0)
                        sp = current->sas_ss_sp + current->sas_ss_size;
        }

        /* Always align the stack frame.  This handles two cases.  First,
         * sigaltstack need not be mindful of platform specific stack
         * alignment.  Second, if we took this signal because the stack
         * is not aligned properly, we'd like to take the signal cleanly
         * and report that.
         */
        sp &= ~7UL;

        return (void __user *)(sp - framesize);
}

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 setup_frame32(struct k_sigaction *ka, struct pt_regs *regs,
                          int signo, sigset_t *oldset)
{
        struct 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 = SF_ALIGNEDSZ;
        if (!(current_thread_info()->fpsaved[0] & FPRS_FEF))
                sigframe_size -= sizeof(__siginfo_fpu_t);

        sf = (struct 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);
}

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)
{
        if (ka->sa.sa_flags & SA_SIGINFO)
                setup_rt_frame32(ka, regs, signr, oldset, info);
        else
                setup_frame32(ka, regs, signr, oldset);

        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,
                 int restart_syscall, unsigned long orig_i0)
{
        struct k_sigaction ka;
        siginfo_t info;
        int signr;
        
        signr = get_signal_to_deliver(&info, &ka, regs, NULL);

        /* If the debugger messes with the program counter, it clears
         * the "in syscall" bit, directing us to not perform a syscall
         * restart.
         */
        if (restart_syscall && !pt_regs_is_syscall(regs))
                restart_syscall = 0;

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

                /* 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 TS_RESTORE_SIGMASK flag.
                 */
                current_thread_info()->status &= ~TS_RESTORE_SIGMASK;

                tracehook_signal_handler(signr, &info, &ka, regs, 0);
                return;
        }
        if (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] = orig_i0;
                regs->tpc -= 4;
                regs->tnpc -= 4;
        }
        if (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 (current_thread_info()->status & TS_RESTORE_SIGMASK) {
                current_thread_info()->status &= ~TS_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;
}