/*  $Id: signal.c,v 1.110 2002/02/08 03:57:14 davem Exp $
 *  linux/arch/sparc/kernel/signal.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)
 */

#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.h>
#include <linux/binfmts.h>      /* do_coredum */
#include <linux/bitops.h>

#include <asm/uaccess.h>
#include <asm/ptrace.h>
#include <asm/svr4.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/cacheflush.h>     /* flush_sig_insns */

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

extern void fpsave(unsigned long *fpregs, unsigned long *fsr,
                   void *fpqueue, unsigned long *fpqdepth);
extern void fpload(unsigned long *fpregs, unsigned long *fsr);

/* 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_sframe {
        struct reg_window       sig_window;
        int                     sig_num;
        int                     sig_code;
        struct sigcontext __user *sig_scptr;
        int                     sig_address;
        struct sigcontext       sig_context;
        unsigned int            extramask[_NSIG_WORDS - 1];
};

/* 
 * 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_frame {
        struct sparc_stackf     ss;
        __siginfo_t             info;
        __siginfo_fpu_t __user  *fpu_save;
        unsigned long           insns[2] __attribute__ ((aligned (8)));
        unsigned int            extramask[_NSIG_WORDS - 1];
        unsigned int            extra_size; /* Should be 0 */
        __siginfo_fpu_t         fpu_state;
};

struct rt_signal_frame {
        struct sparc_stackf     ss;
        siginfo_t               info;
        struct pt_regs          regs;
        sigset_t                mask;
        __siginfo_fpu_t __user  *fpu_save;
        unsigned int            insns[2];
        stack_t                 stack;
        unsigned int            extra_size; /* Should be 0 */
        __siginfo_fpu_t         fpu_state;
};

/* Align macros */
#define SF_ALIGNEDSZ  (((sizeof(struct signal_sframe) + 7) & (~7)))
#define NF_ALIGNEDSZ  (((sizeof(struct new_signal_frame) + 7) & (~7)))
#define RT_ALIGNEDSZ  (((sizeof(struct rt_signal_frame) + 7) & (~7)))

static int _sigpause_common(old_sigset_t set)
{
        set &= _BLOCKABLE;
        spin_lock_irq(&current->sighand->siglock);
        current->saved_sigmask = current->blocked;
        siginitset(&current->blocked, set);
        recalc_sigpending();
        spin_unlock_irq(&current->sighand->siglock);

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

        return -ERESTARTNOHAND;
}

asmlinkage int sys_sigpause(unsigned int set)
{
        return _sigpause_common(set);
}

asmlinkage int sys_sigsuspend(old_sigset_t set)
{
        return _sigpause_common(set);
}

static inline int
restore_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
{
        int err;
#ifdef CONFIG_SMP
        if (test_tsk_thread_flag(current, TIF_USEDFPU))
                regs->psr &= ~PSR_EF;
#else
        if (current == last_task_used_math) {
                last_task_used_math = NULL;
                regs->psr &= ~PSR_EF;
        }
#endif
        set_used_math();
        clear_tsk_thread_flag(current, TIF_USEDFPU);

        if (!access_ok(VERIFY_READ, fpu, sizeof(*fpu)))
                return -EFAULT;

        err = __copy_from_user(&current->thread.float_regs[0], &fpu->si_float_regs[0],
                               (sizeof(unsigned long) * 32));
        err |= __get_user(current->thread.fsr, &fpu->si_fsr);
        err |= __get_user(current->thread.fpqdepth, &fpu->si_fpqdepth);
        if (current->thread.fpqdepth != 0)
                err |= __copy_from_user(&current->thread.fpqueue[0],
                                        &fpu->si_fpqueue[0],
                                        ((sizeof(unsigned long) +
                                        (sizeof(unsigned long *)))*16));
        return err;
}

static inline void do_new_sigreturn (struct pt_regs *regs)
{
        struct new_signal_frame __user *sf;
        unsigned long up_psr, pc, npc;
        sigset_t set;
        __siginfo_fpu_t __user *fpu_save;
        int err;

        sf = (struct new_signal_frame __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)))
                goto segv_and_exit;

        if (((unsigned long) sf) & 3)
                goto segv_and_exit;

        err = __get_user(pc,  &sf->info.si_regs.pc);
        err |= __get_user(npc, &sf->info.si_regs.npc);

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

        /* 2. Restore the state */
        up_psr = regs->psr;
        err |= __copy_from_user(regs, &sf->info.si_regs, sizeof(struct pt_regs));

        /* User can only change condition codes and FPU enabling in %psr. */
        regs->psr = (up_psr & ~(PSR_ICC | PSR_EF))
                  | (regs->psr & (PSR_ICC | PSR_EF));

        err |= __get_user(fpu_save, &sf->fpu_save);

        if (fpu_save)
                err |= restore_fpu_state(regs, fpu_save);

        /* This is pretty much atomic, no amount locking would prevent
         * the races which exist anyways.
         */
        err |= __get_user(set.sig[0], &sf->info.si_mask);
        err |= __copy_from_user(&set.sig[1], &sf->extramask,
                                (_NSIG_WORDS-1) * sizeof(unsigned int));
                           
        if (err)
                goto segv_and_exit;

        sigdelsetmask(&set, ~_BLOCKABLE);
        spin_lock_irq(&current->sighand->siglock);
        current->blocked = set;
        recalc_sigpending();
        spin_unlock_irq(&current->sighand->siglock);
        return;

segv_and_exit:
        force_sig(SIGSEGV, current);
}

asmlinkage void do_sigreturn(struct pt_regs *regs)
{
        struct sigcontext __user *scptr;
        unsigned long pc, npc, psr;
        sigset_t set;
        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 (current->thread.new_signal) {
                do_new_sigreturn(regs);
                return;
        }

        scptr = (struct sigcontext __user *) regs->u_regs[UREG_I0];

        /* Check sanity of the user arg. */
        if (!access_ok(VERIFY_READ, scptr, sizeof(struct sigcontext)) ||
            (((unsigned long) scptr) & 3))
                goto segv_and_exit;

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

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

        /* This is pretty much atomic, no amount locking would prevent
         * the races which exist anyways.
         */
        err |= __get_user(set.sig[0], &scptr->sigc_mask);
        /* Note that scptr + 1 points to extramask */
        err |= __copy_from_user(&set.sig[1], scptr + 1,
                                (_NSIG_WORDS - 1) * sizeof(unsigned int));
        
        if (err)
                goto segv_and_exit;

        sigdelsetmask(&set, ~_BLOCKABLE);
        spin_lock_irq(&current->sighand->siglock);
        current->blocked = set;
        recalc_sigpending();
        spin_unlock_irq(&current->sighand->siglock);

        regs->pc = pc;
        regs->npc = 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 %psr. */
        err |= __get_user(psr, &scptr->sigc_psr);
        if (err)
                goto segv_and_exit;
                
        regs->psr &= ~(PSR_ICC);
        regs->psr |= (psr & PSR_ICC);
        return;

segv_and_exit:
        force_sig(SIGSEGV, current);
}

asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
{
        struct rt_signal_frame __user *sf;
        unsigned int psr, pc, npc;
        __siginfo_fpu_t __user *fpu_save;
        mm_segment_t old_fs;
        sigset_t set;
        stack_t st;
        int err;

        synchronize_user_stack();
        sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP];
        if (!access_ok(VERIFY_READ, sf, sizeof(*sf)) ||
            (((unsigned long) sf) & 0x03))
                goto segv;

        err = __get_user(pc, &sf->regs.pc);
        err |= __get_user(npc, &sf->regs.npc);
        err |= ((pc | npc) & 0x03);

        err |= __get_user(regs->y, &sf->regs.y);
        err |= __get_user(psr, &sf->regs.psr);

        err |= __copy_from_user(&regs->u_regs[UREG_G1],
                                &sf->regs.u_regs[UREG_G1], 15 * sizeof(u32));

        regs->psr = (regs->psr & ~PSR_ICC) | (psr & PSR_ICC);

        err |= __get_user(fpu_save, &sf->fpu_save);

        if (fpu_save)
                err |= restore_fpu_state(regs, fpu_save);
        err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
        
        err |= __copy_from_user(&st, &sf->stack, sizeof(stack_t));
        
        if (err)
                goto segv;
                
        regs->pc = pc;
        regs->npc = npc;
        
        /* 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((const stack_t __user *) &st, NULL, (unsigned long)sf);
        set_fs(old_fs);

        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 inline int invalid_frame_pointer(void __user *fp, int fplen)
{
        if ((((unsigned long) fp) & 7) ||
            !__access_ok((unsigned long)fp, fplen) ||
            ((sparc_cpu_model == sun4 || sparc_cpu_model == sun4c) &&
             ((unsigned long) fp < 0xe0000000 && (unsigned long) fp >= 0x20000000)))
                return 1;
        
        return 0;
}

static inline void __user *get_sigframe(struct sigaction *sa, struct pt_regs *regs, unsigned long framesize)
{
        unsigned long sp;

        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 inline void
setup_frame(struct sigaction *sa, struct pt_regs *regs, int signr, sigset_t *oldset, siginfo_t *info)
{
        struct signal_sframe __user *sframep;
        struct sigcontext __user *sc;
        int window = 0, err;
        unsigned long pc = regs->pc;
        unsigned long npc = regs->npc;
        struct thread_info *tp = current_thread_info();
        void __user *sig_address;
        int sig_code;

        synchronize_user_stack();
        sframep = (struct signal_sframe __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.
                 */
                goto sigill_and_return;
        }

        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);
        err |= __put_user(oldset->sig[0], &sc->sigc_mask);
        err |= __copy_to_user(sframep->extramask, &oldset->sig[1],
                              (_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);
        err |= __put_user(regs->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(tp->w_saved, &sc->sigc_oswins);
        if (tp->w_saved)
                for (window = 0; window < tp->w_saved; window++) {
                        put_user((char *)tp->rwbuf_stkptrs[window],
                                 &sc->sigc_spbuf[window]);
                        err |= __copy_to_user(&sc->sigc_wbuf[window],
                                              &tp->reg_window[window],
                                              sizeof(struct reg_window));
                }
        else
                err |= __copy_to_user(sframep, (char *) regs->u_regs[UREG_FP],
                                      sizeof(struct reg_window));

        tp->w_saved = 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_sunos.c */
                                sig_code = info->si_trapno;
                                break;
                        }
                default:
                        sig_address = NULL;
                }
        }
        err |= __put_user((unsigned long)sig_address, &sframep->sig_address);
        err |= __put_user(sig_code, &sframep->sig_code);
        err |= __put_user(sc, &sframep->sig_scptr);
        if (err)
                goto sigsegv;

        regs->u_regs[UREG_FP] = (unsigned long) sframep;
        regs->pc = (unsigned long) sa->sa_handler;
        regs->npc = (regs->pc + 4);
        return;

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


static inline int
save_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
{
        int err = 0;
#ifdef CONFIG_SMP
        if (test_tsk_thread_flag(current, TIF_USEDFPU)) {
                put_psr(get_psr() | PSR_EF);
                fpsave(&current->thread.float_regs[0], &current->thread.fsr,
                       &current->thread.fpqueue[0], &current->thread.fpqdepth);
                regs->psr &= ~(PSR_EF);
                clear_tsk_thread_flag(current, TIF_USEDFPU);
        }
#else
        if (current == last_task_used_math) {
                put_psr(get_psr() | PSR_EF);
                fpsave(&current->thread.float_regs[0], &current->thread.fsr,
                       &current->thread.fpqueue[0], &current->thread.fpqdepth);
                last_task_used_math = NULL;
                regs->psr &= ~(PSR_EF);
        }
#endif
        err |= __copy_to_user(&fpu->si_float_regs[0],
                              &current->thread.float_regs[0],
                              (sizeof(unsigned long) * 32));
        err |= __put_user(current->thread.fsr, &fpu->si_fsr);
        err |= __put_user(current->thread.fpqdepth, &fpu->si_fpqdepth);
        if (current->thread.fpqdepth != 0)
                err |= __copy_to_user(&fpu->si_fpqueue[0],
                                      &current->thread.fpqueue[0],
                                      ((sizeof(unsigned long) +
                                      (sizeof(unsigned long *)))*16));
        clear_used_math();
        return err;
}

static inline void
new_setup_frame(struct k_sigaction *ka, struct pt_regs *regs,
                int signo, sigset_t *oldset)
{
        struct new_signal_frame __user *sf;
        int sigframe_size, err;

        /* 1. Make sure everything is clean */
        synchronize_user_stack();

        sigframe_size = NF_ALIGNEDSZ;
        if (!used_math())
                sigframe_size -= sizeof(__siginfo_fpu_t);

        sf = (struct new_signal_frame __user *)
                get_sigframe(&ka->sa, regs, sigframe_size);

        if (invalid_frame_pointer(sf, sigframe_size))
                goto sigill_and_return;

        if (current_thread_info()->w_saved != 0)
                goto sigill_and_return;

        /* 2. Save the current process state */
        err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs));
        
        err |= __put_user(0, &sf->extra_size);

        if (used_math()) {
                err |= save_fpu_state(regs, &sf->fpu_state);
                err |= __put_user(&sf->fpu_state, &sf->fpu_save);
        } else {
                err |= __put_user(0, &sf->fpu_save);
        }

        err |= __put_user(oldset->sig[0], &sf->info.si_mask);
        err |= __copy_to_user(sf->extramask, &oldset->sig[1],
                              (_NSIG_WORDS - 1) * sizeof(unsigned int));
        err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
                              sizeof(struct reg_window));
        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->pc = (unsigned long) ka->sa.sa_handler;
        regs->npc = (regs->pc + 4);

        /* 5. return to kernel instructions */
        if (ka->ka_restorer)
                regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
        else {
                regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);

                /* mov __NR_sigreturn, %g1 */
                err |= __put_user(0x821020d8, &sf->insns[0]);

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

                /* Flush instruction space. */
                flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
        }
        return;

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

static inline void
new_setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
                   int signo, sigset_t *oldset, siginfo_t *info)
{
        struct rt_signal_frame __user *sf;
        int sigframe_size;
        unsigned int psr;
        int err;

        synchronize_user_stack();
        sigframe_size = RT_ALIGNEDSZ;
        if (!used_math())
                sigframe_size -= sizeof(__siginfo_fpu_t);
        sf = (struct rt_signal_frame __user *)
                get_sigframe(&ka->sa, regs, sigframe_size);
        if (invalid_frame_pointer(sf, sigframe_size))
                goto sigill;
        if (current_thread_info()->w_saved != 0)
                goto sigill;

        err  = __put_user(regs->pc, &sf->regs.pc);
        err |= __put_user(regs->npc, &sf->regs.npc);
        err |= __put_user(regs->y, &sf->regs.y);
        psr = regs->psr;
        if (used_math())
                psr |= PSR_EF;
        err |= __put_user(psr, &sf->regs.psr);
        err |= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs));
        err |= __put_user(0, &sf->extra_size);

        if (psr & PSR_EF) {
                err |= save_fpu_state(regs, &sf->fpu_state);
                err |= __put_user(&sf->fpu_state, &sf->fpu_save);
        } else {
                err |= __put_user(0, &sf->fpu_save);
        }
        err |= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t));
        
        /* 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);
        
        err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
                              sizeof(struct reg_window));       

        err |= copy_siginfo_to_user(&sf->info, info);

        if (err)
                goto sigsegv;

        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->regs;

        regs->pc = (unsigned long) ka->sa.sa_handler;
        regs->npc = (regs->pc + 4);

        if (ka->ka_restorer)
                regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
        else {
                regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);

                /* mov __NR_sigreturn, %g1 */
                err |= __put_user(0x821020d8, &sf->insns[0]);

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

                /* Flush instruction space. */
                flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
        }
        return;

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

/* Setup a Solaris stack frame */
static inline void
setup_svr4_frame(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;
        struct thread_info *tp = current_thread_info();
        int window = 0, err;

        synchronize_user_stack();
        sfp = (svr4_signal_frame_t __user *)
                get_sigframe(sa, regs, SVR4_SF_ALIGNED + sizeof(struct reg_window));

        if (invalid_frame_pointer(sfp, sizeof(*sfp)))
                goto sigill_and_return;

        /* 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[1];
        if (_NSIG_WORDS >= 4) {
                setv.sigbits[2] = oldset->sig[2];
                setv.sigbits[3] = oldset->sig[3];
                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 */
        err |= __put_user(regs->pc, &((*gr)[SVR4_PC]));
        err |= __put_user(regs->npc, &((*gr)[SVR4_NPC]));
        err |= __put_user(regs->psr, &((*gr)[SVR4_PSR]));
        err |= __put_user(regs->y, &((*gr)[SVR4_Y]));
        
        /* Copy g[1..7] and o[0..7] registers */
        err |= __copy_to_user(&(*gr)[SVR4_G1], &regs->u_regs[UREG_G1],
                              sizeof(long) * 7);
        err |= __copy_to_user(&(*gr)[SVR4_O0], &regs->u_regs[UREG_I0],
                              sizeof(long) * 8);

        /* 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(gw, &mc->gwin);
            
        /* 2. Number of windows to restore at setcontext(): */
        err |= __put_user(tp->w_saved, &gw->count);

        /* 3. Save each valid window
         *    Currently, it makes a copy of the windows from the kernel copy.
         *    David's code for SunOS, makes the copy but keeps the pointer to
         *    the kernel.  My version makes the pointer point to a userland 
         *    copy of those.  Mhm, I wonder if I shouldn't just ignore those
         *    on setcontext and use those that are on the kernel, the signal
         *    handler should not be modyfing those, mhm.
         *
         *    These windows are just used in case synchronize_user_stack failed
         *    to flush the user windows.
         */
        for (window = 0; window < tp->w_saved; window++) {
                err |= __put_user((int __user *) &(gw->win[window]), &gw->winptr[window]);
                err |= __copy_to_user(&gw->win[window],
                                      &tp->reg_window[window],
                                      sizeof(svr4_rwindow_t));
                err |= __put_user(0, gw->winptr[window]);
        }

        /* 4. We just pay attention to the gw->count field on setcontext */
        tp->w_saved = 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->pc = (unsigned long) sa->sa_handler;
        regs->npc = (regs->pc + 4);

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

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

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

sigill_and_return:
        do_exit(SIGILL);
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 err = 0;

        synchronize_user_stack();

        if (current_thread_info()->w_saved)
                return -EFAULT;

        err = clear_user(uc, sizeof(*uc));
        if (err)
                return -EFAULT;

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

        setv.sigbits[0] = current->blocked.sig[0];
        setv.sigbits[1] = current->blocked.sig[1];
        if (_NSIG_WORDS >= 4) {
                setv.sigbits[2] = current->blocked.sig[2];
                setv.sigbits[3] = current->blocked.sig[3];
                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 */
        err |= __put_user(regs->pc, &uc->mcontext.greg[SVR4_PC]);
        err |= __put_user(regs->npc, &uc->mcontext.greg[SVR4_NPC]);
        err |= __put_user(regs->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 */
        err |= __copy_to_user(&(*gr)[SVR4_G1], &regs->u_regs[UREG_G1],
                              sizeof(uint) * 7);
        err |= __copy_to_user(&(*gr)[SVR4_O0], &regs->u_regs[UREG_I0],
                              sizeof(uint) * 8);

        /* 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;
        unsigned long pc, npc, psr;
        mm_segment_t old_fs;
        sigset_t set;
        svr4_sigset_t setv;
        int 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 (current_thread_info()->w_saved)
                goto sigsegv_and_return;

        if (((unsigned long) c) & 3)
                goto sigsegv_and_return;

        if (!__access_ok((unsigned long)c, sizeof(*c)))
                goto sigsegv_and_return;

        /* 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_and_return;

        /* 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 */

        /* This is pretty much atomic, no amount locking would prevent
         * the races which exist anyways.
         */
        err |= __copy_from_user(&setv, &c->sigmask, sizeof(svr4_sigset_t));
        
        err |= __get_user(st.ss_sp, &c->stack.sp);
        err |= __get_user(st.ss_flags, &c->stack.flags);
        err |= __get_user(st.ss_size, &c->stack.size);
        
        if (err)
                goto sigsegv_and_return;
                
        /* 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((const stack_t __user *) &st, NULL,
                       regs->u_regs[UREG_I6]);
        set_fs(old_fs);
        
        set.sig[0] = setv.sigbits[0];
        set.sig[1] = setv.sigbits[1];
        if (_NSIG_WORDS >= 4) {
                set.sig[2] = setv.sigbits[2];
                set.sig[3] = setv.sigbits[3];
        }
        sigdelsetmask(&set, ~_BLOCKABLE);
        spin_lock_irq(&current->sighand->siglock);
        current->blocked = set;
        recalc_sigpending();
        spin_unlock_irq(&current->sighand->siglock);
        regs->pc = pc;
        regs->npc = npc | 1;
        err |= __get_user(regs->y, &((*gr)[SVR4_Y]));
        err |= __get_user(psr, &((*gr)[SVR4_PSR]));
        regs->psr &= ~(PSR_ICC);
        regs->psr |= (psr & PSR_ICC);

        /* Restore g[1..7] and o[0..7] registers */
        err |= __copy_from_user(&regs->u_regs[UREG_G1], &(*gr)[SVR4_G1],
                              sizeof(long) * 7);
        err |= __copy_from_user(&regs->u_regs[UREG_I0], &(*gr)[SVR4_O0],
                              sizeof(long) * 8);
        return (err ? -EFAULT : 0);

sigsegv_and_return:
        force_sig(SIGSEGV, current);
        return -EFAULT;
}

static inline void
handle_signal(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_frame(&ka->sa, regs->pc, regs->npc, regs, signr, oldset);
        else {
                if (ka->sa.sa_flags & SA_SIGINFO)
                        new_setup_rt_frame(ka, regs, signr, oldset, info);
                else if (current->thread.new_signal)
                        new_setup_frame(ka, regs, signr, oldset);
                else
                        setup_frame(&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_restart(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->psr |= PSR_C;
                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->pc -= 4;
                regs->npc -= 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.
 */
asmlinkage void do_signal(struct pt_regs * regs, unsigned long orig_i0, int restart_syscall)
{
        siginfo_t info;
        struct sparc_deliver_cookie cookie;

        struct k_sigaction ka;
        int signr;
        sigset_t *oldset;

        /*
         * XXX Disable svr4 signal handling until solaris emulation works.
         * It is buggy - Anton
         */
#define SVR4_SIGNAL_BROKEN 1
#ifdef SVR4_SIGNAL_BROKEN
        int svr4_signal = 0;
#else
        int svr4_signal = current->personality == PER_SVR4;
#endif

        cookie.restart_syscall = restart_syscall;
        cookie.orig_i0 = orig_i0;

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

        signr = get_signal_to_deliver(&info, &ka, regs, &cookie);
        if (signr > 0) {
                if (cookie.restart_syscall)
                        syscall_restart(cookie.orig_i0, regs, &ka.sa);
                handle_signal(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->pc -= 4;
                regs->npc -= 4;
        }
        if (cookie.restart_syscall &&
            regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
                regs->u_regs[UREG_G1] = __NR_restart_syscall;
                regs->pc -= 4;
                regs->npc -= 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);
        }
}

asmlinkage int
do_sys_sigstack(struct sigstack __user *ssptr, struct sigstack __user *ossptr,
                unsigned long sp)
{
        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) {
                char *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;
}

void ptrace_signal_deliver(struct pt_regs *regs, void *cookie)
{
        struct sparc_deliver_cookie *cp = cookie;

        if (cp->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] = cp->orig_i0;
                regs->pc -= 4;
                regs->npc -= 4;
                cp->restart_syscall = 0;
        }

        if (cp->restart_syscall &&
            regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
                regs->u_regs[UREG_G1] = __NR_restart_syscall;
                regs->pc -= 4;
                regs->npc -= 4;
                cp->restart_syscall = 0;
        }
}