/*
 *  linux/kernel/compat.c
 *
 *  Kernel compatibililty routines for e.g. 32 bit syscall support
 *  on 64 bit kernels.
 *
 *  Copyright (C) 2002-2003 Stephen Rothwell, IBM Corporation
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 */

#include <linux/linkage.h>
#include <linux/compat.h>
#include <linux/errno.h>
#include <linux/time.h>
#include <linux/signal.h>
#include <linux/sched.h>        /* for MAX_SCHEDULE_TIMEOUT */
#include <linux/syscalls.h>
#include <linux/unistd.h>
#include <linux/security.h>
#include <linux/timex.h>
#include <linux/export.h>
#include <linux/migrate.h>
#include <linux/posix-timers.h>
#include <linux/times.h>
#include <linux/ptrace.h>
#include <linux/gfp.h>

#include <asm/uaccess.h>

static int compat_get_timex(struct timex *txc, struct compat_timex __user *utp)
{
        memset(txc, 0, sizeof(struct timex));

        if (!access_ok(VERIFY_READ, utp, sizeof(struct compat_timex)) ||
                        __get_user(txc->modes, &utp->modes) ||
                        __get_user(txc->offset, &utp->offset) ||
                        __get_user(txc->freq, &utp->freq) ||
                        __get_user(txc->maxerror, &utp->maxerror) ||
                        __get_user(txc->esterror, &utp->esterror) ||
                        __get_user(txc->status, &utp->status) ||
                        __get_user(txc->constant, &utp->constant) ||
                        __get_user(txc->precision, &utp->precision) ||
                        __get_user(txc->tolerance, &utp->tolerance) ||
                        __get_user(txc->time.tv_sec, &utp->time.tv_sec) ||
                        __get_user(txc->time.tv_usec, &utp->time.tv_usec) ||
                        __get_user(txc->tick, &utp->tick) ||
                        __get_user(txc->ppsfreq, &utp->ppsfreq) ||
                        __get_user(txc->jitter, &utp->jitter) ||
                        __get_user(txc->shift, &utp->shift) ||
                        __get_user(txc->stabil, &utp->stabil) ||
                        __get_user(txc->jitcnt, &utp->jitcnt) ||
                        __get_user(txc->calcnt, &utp->calcnt) ||
                        __get_user(txc->errcnt, &utp->errcnt) ||
                        __get_user(txc->stbcnt, &utp->stbcnt))
                return -EFAULT;

        return 0;
}

static int compat_put_timex(struct compat_timex __user *utp, struct timex *txc)
{
        if (!access_ok(VERIFY_WRITE, utp, sizeof(struct compat_timex)) ||
                        __put_user(txc->modes, &utp->modes) ||
                        __put_user(txc->offset, &utp->offset) ||
                        __put_user(txc->freq, &utp->freq) ||
                        __put_user(txc->maxerror, &utp->maxerror) ||
                        __put_user(txc->esterror, &utp->esterror) ||
                        __put_user(txc->status, &utp->status) ||
                        __put_user(txc->constant, &utp->constant) ||
                        __put_user(txc->precision, &utp->precision) ||
                        __put_user(txc->tolerance, &utp->tolerance) ||
                        __put_user(txc->time.tv_sec, &utp->time.tv_sec) ||
                        __put_user(txc->time.tv_usec, &utp->time.tv_usec) ||
                        __put_user(txc->tick, &utp->tick) ||
                        __put_user(txc->ppsfreq, &utp->ppsfreq) ||
                        __put_user(txc->jitter, &utp->jitter) ||
                        __put_user(txc->shift, &utp->shift) ||
                        __put_user(txc->stabil, &utp->stabil) ||
                        __put_user(txc->jitcnt, &utp->jitcnt) ||
                        __put_user(txc->calcnt, &utp->calcnt) ||
                        __put_user(txc->errcnt, &utp->errcnt) ||
                        __put_user(txc->stbcnt, &utp->stbcnt) ||
                        __put_user(txc->tai, &utp->tai))
                return -EFAULT;
        return 0;
}

COMPAT_SYSCALL_DEFINE2(gettimeofday, struct compat_timeval __user *, tv,
                       struct timezone __user *, tz)
{
        if (tv) {
                struct timeval ktv;
                do_gettimeofday(&ktv);
                if (compat_put_timeval(&ktv, tv))
                        return -EFAULT;
        }
        if (tz) {
                if (copy_to_user(tz, &sys_tz, sizeof(sys_tz)))
                        return -EFAULT;
        }

        return 0;
}

COMPAT_SYSCALL_DEFINE2(settimeofday, struct compat_timeval __user *, tv,
                       struct timezone __user *, tz)
{
        struct timeval user_tv;
        struct timespec new_ts;
        struct timezone new_tz;

        if (tv) {
                if (compat_get_timeval(&user_tv, tv))
                        return -EFAULT;
                new_ts.tv_sec = user_tv.tv_sec;
                new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC;
        }
        if (tz) {
                if (copy_from_user(&new_tz, tz, sizeof(*tz)))
                        return -EFAULT;
        }

        return do_sys_settimeofday(tv ? &new_ts : NULL, tz ? &new_tz : NULL);
}

static int __compat_get_timeval(struct timeval *tv, const struct compat_timeval __user *ctv)
{
        return (!access_ok(VERIFY_READ, ctv, sizeof(*ctv)) ||
                        __get_user(tv->tv_sec, &ctv->tv_sec) ||
                        __get_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
}

static int __compat_put_timeval(const struct timeval *tv, struct compat_timeval __user *ctv)
{
        return (!access_ok(VERIFY_WRITE, ctv, sizeof(*ctv)) ||
                        __put_user(tv->tv_sec, &ctv->tv_sec) ||
                        __put_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
}

static int __compat_get_timespec(struct timespec *ts, const struct compat_timespec __user *cts)
{
        return (!access_ok(VERIFY_READ, cts, sizeof(*cts)) ||
                        __get_user(ts->tv_sec, &cts->tv_sec) ||
                        __get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
}

static int __compat_put_timespec(const struct timespec *ts, struct compat_timespec __user *cts)
{
        return (!access_ok(VERIFY_WRITE, cts, sizeof(*cts)) ||
                        __put_user(ts->tv_sec, &cts->tv_sec) ||
                        __put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
}

int compat_get_timeval(struct timeval *tv, const void __user *utv)
{
        if (COMPAT_USE_64BIT_TIME)
                return copy_from_user(tv, utv, sizeof(*tv)) ? -EFAULT : 0;
        else
                return __compat_get_timeval(tv, utv);
}
EXPORT_SYMBOL_GPL(compat_get_timeval);

int compat_put_timeval(const struct timeval *tv, void __user *utv)
{
        if (COMPAT_USE_64BIT_TIME)
                return copy_to_user(utv, tv, sizeof(*tv)) ? -EFAULT : 0;
        else
                return __compat_put_timeval(tv, utv);
}
EXPORT_SYMBOL_GPL(compat_put_timeval);

int compat_get_timespec(struct timespec *ts, const void __user *uts)
{
        if (COMPAT_USE_64BIT_TIME)
                return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0;
        else
                return __compat_get_timespec(ts, uts);
}
EXPORT_SYMBOL_GPL(compat_get_timespec);

int compat_put_timespec(const struct timespec *ts, void __user *uts)
{
        if (COMPAT_USE_64BIT_TIME)
                return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0;
        else
                return __compat_put_timespec(ts, uts);
}
EXPORT_SYMBOL_GPL(compat_put_timespec);

int compat_convert_timespec(struct timespec __user **kts,
                            const void __user *cts)
{
        struct timespec ts;
        struct timespec __user *uts;

        if (!cts || COMPAT_USE_64BIT_TIME) {
                *kts = (struct timespec __user *)cts;
                return 0;
        }

        uts = compat_alloc_user_space(sizeof(ts));
        if (!uts)
                return -EFAULT;
        if (compat_get_timespec(&ts, cts))
                return -EFAULT;
        if (copy_to_user(uts, &ts, sizeof(ts)))
                return -EFAULT;

        *kts = uts;
        return 0;
}

static long compat_nanosleep_restart(struct restart_block *restart)
{
        struct compat_timespec __user *rmtp;
        struct timespec rmt;
        mm_segment_t oldfs;
        long ret;

        restart->nanosleep.rmtp = (struct timespec __user *) &rmt;
        oldfs = get_fs();
        set_fs(KERNEL_DS);
        ret = hrtimer_nanosleep_restart(restart);
        set_fs(oldfs);

        if (ret == -ERESTART_RESTARTBLOCK) {
                rmtp = restart->nanosleep.compat_rmtp;

                if (rmtp && compat_put_timespec(&rmt, rmtp))
                        return -EFAULT;
        }

        return ret;
}

COMPAT_SYSCALL_DEFINE2(nanosleep, struct compat_timespec __user *, rqtp,
                       struct compat_timespec __user *, rmtp)
{
        struct timespec tu, rmt;
        mm_segment_t oldfs;
        long ret;

        if (compat_get_timespec(&tu, rqtp))
                return -EFAULT;

        if (!timespec_valid(&tu))
                return -EINVAL;

        oldfs = get_fs();
        set_fs(KERNEL_DS);
        ret = hrtimer_nanosleep(&tu,
                                rmtp ? (struct timespec __user *)&rmt : NULL,
                                HRTIMER_MODE_REL, CLOCK_MONOTONIC);
        set_fs(oldfs);

        /*
         * hrtimer_nanosleep() can only return 0 or
         * -ERESTART_RESTARTBLOCK here because:
         *
         * - we call it with HRTIMER_MODE_REL and therefor exclude the
         *   -ERESTARTNOHAND return path.
         *
         * - we supply the rmtp argument from the task stack (due to
         *   the necessary compat conversion. So the update cannot
         *   fail, which excludes the -EFAULT return path as well. If
         *   it fails nevertheless we have a bigger problem and wont
         *   reach this place anymore.
         *
         * - if the return value is 0, we do not have to update rmtp
         *    because there is no remaining time.
         *
         * We check for -ERESTART_RESTARTBLOCK nevertheless if the
         * core implementation decides to return random nonsense.
         */
        if (ret == -ERESTART_RESTARTBLOCK) {
                struct restart_block *restart = &current->restart_block;

                restart->fn = compat_nanosleep_restart;
                restart->nanosleep.compat_rmtp = rmtp;

                if (rmtp && compat_put_timespec(&rmt, rmtp))
                        return -EFAULT;
        }
        return ret;
}

static inline long get_compat_itimerval(struct itimerval *o,
                struct compat_itimerval __user *i)
{
        return (!access_ok(VERIFY_READ, i, sizeof(*i)) ||
                (__get_user(o->it_interval.tv_sec, &i->it_interval.tv_sec) |
                 __get_user(o->it_interval.tv_usec, &i->it_interval.tv_usec) |
                 __get_user(o->it_value.tv_sec, &i->it_value.tv_sec) |
                 __get_user(o->it_value.tv_usec, &i->it_value.tv_usec)));
}

static inline long put_compat_itimerval(struct compat_itimerval __user *o,
                struct itimerval *i)
{
        return (!access_ok(VERIFY_WRITE, o, sizeof(*o)) ||
                (__put_user(i->it_interval.tv_sec, &o->it_interval.tv_sec) |
                 __put_user(i->it_interval.tv_usec, &o->it_interval.tv_usec) |
                 __put_user(i->it_value.tv_sec, &o->it_value.tv_sec) |
                 __put_user(i->it_value.tv_usec, &o->it_value.tv_usec)));
}

COMPAT_SYSCALL_DEFINE2(getitimer, int, which,
                struct compat_itimerval __user *, it)
{
        struct itimerval kit;
        int error;

        error = do_getitimer(which, &kit);
        if (!error && put_compat_itimerval(it, &kit))
                error = -EFAULT;
        return error;
}

COMPAT_SYSCALL_DEFINE3(setitimer, int, which,
                struct compat_itimerval __user *, in,
                struct compat_itimerval __user *, out)
{
        struct itimerval kin, kout;
        int error;

        if (in) {
                if (get_compat_itimerval(&kin, in))
                        return -EFAULT;
        } else
                memset(&kin, 0, sizeof(kin));

        error = do_setitimer(which, &kin, out ? &kout : NULL);
        if (error || !out)
                return error;
        if (put_compat_itimerval(out, &kout))
                return -EFAULT;
        return 0;
}

static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
{
        return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
}

COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf)
{
        if (tbuf) {
                struct tms tms;
                struct compat_tms tmp;

                do_sys_times(&tms);
                /* Convert our struct tms to the compat version. */
                tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
                tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
                tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
                tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
                if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
                        return -EFAULT;
        }
        force_successful_syscall_return();
        return compat_jiffies_to_clock_t(jiffies);
}

#ifdef __ARCH_WANT_SYS_SIGPENDING

/*
 * Assumption: old_sigset_t and compat_old_sigset_t are both
 * types that can be passed to put_user()/get_user().
 */

COMPAT_SYSCALL_DEFINE1(sigpending, compat_old_sigset_t __user *, set)
{
        old_sigset_t s;
        long ret;
        mm_segment_t old_fs = get_fs();

        set_fs(KERNEL_DS);
        ret = sys_sigpending((old_sigset_t __user *) &s);
        set_fs(old_fs);
        if (ret == 0)
                ret = put_user(s, set);
        return ret;
}

#endif

#ifdef __ARCH_WANT_SYS_SIGPROCMASK

/*
 * sys_sigprocmask SIG_SETMASK sets the first (compat) word of the
 * blocked set of signals to the supplied signal set
 */
static inline void compat_sig_setmask(sigset_t *blocked, compat_sigset_word set)
{
        memcpy(blocked->sig, &set, sizeof(set));
}

COMPAT_SYSCALL_DEFINE3(sigprocmask, int, how,
                       compat_old_sigset_t __user *, nset,
                       compat_old_sigset_t __user *, oset)
{
        old_sigset_t old_set, new_set;
        sigset_t new_blocked;

        old_set = current->blocked.sig[0];

        if (nset) {
                if (get_user(new_set, nset))
                        return -EFAULT;
                new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP));

                new_blocked = current->blocked;

                switch (how) {
                case SIG_BLOCK:
                        sigaddsetmask(&new_blocked, new_set);
                        break;
                case SIG_UNBLOCK:
                        sigdelsetmask(&new_blocked, new_set);
                        break;
                case SIG_SETMASK:
                        compat_sig_setmask(&new_blocked, new_set);
                        break;
                default:
                        return -EINVAL;
                }

                set_current_blocked(&new_blocked);
        }

        if (oset) {
                if (put_user(old_set, oset))
                        return -EFAULT;
        }

        return 0;
}

#endif

COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource,
                       struct compat_rlimit __user *, rlim)
{
        struct rlimit r;

        if (!access_ok(VERIFY_READ, rlim, sizeof(*rlim)) ||
            __get_user(r.rlim_cur, &rlim->rlim_cur) ||
            __get_user(r.rlim_max, &rlim->rlim_max))
                return -EFAULT;

        if (r.rlim_cur == COMPAT_RLIM_INFINITY)
                r.rlim_cur = RLIM_INFINITY;
        if (r.rlim_max == COMPAT_RLIM_INFINITY)
                r.rlim_max = RLIM_INFINITY;
        return do_prlimit(current, resource, &r, NULL);
}

#ifdef COMPAT_RLIM_OLD_INFINITY

COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
                       struct compat_rlimit __user *, rlim)
{
        struct rlimit r;
        int ret;
        mm_segment_t old_fs = get_fs();

        set_fs(KERNEL_DS);
        ret = sys_old_getrlimit(resource, (struct rlimit __user *)&r);
        set_fs(old_fs);

        if (!ret) {
                if (r.rlim_cur > COMPAT_RLIM_OLD_INFINITY)
                        r.rlim_cur = COMPAT_RLIM_INFINITY;
                if (r.rlim_max > COMPAT_RLIM_OLD_INFINITY)
                        r.rlim_max = COMPAT_RLIM_INFINITY;

                if (!access_ok(VERIFY_WRITE, rlim, sizeof(*rlim)) ||
                    __put_user(r.rlim_cur, &rlim->rlim_cur) ||
                    __put_user(r.rlim_max, &rlim->rlim_max))
                        return -EFAULT;
        }
        return ret;
}

#endif

COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource,
                       struct compat_rlimit __user *, rlim)
{
        struct rlimit r;
        int ret;

        ret = do_prlimit(current, resource, NULL, &r);
        if (!ret) {
                if (r.rlim_cur > COMPAT_RLIM_INFINITY)
                        r.rlim_cur = COMPAT_RLIM_INFINITY;
                if (r.rlim_max > COMPAT_RLIM_INFINITY)
                        r.rlim_max = COMPAT_RLIM_INFINITY;

                if (!access_ok(VERIFY_WRITE, rlim, sizeof(*rlim)) ||
                    __put_user(r.rlim_cur, &rlim->rlim_cur) ||
                    __put_user(r.rlim_max, &rlim->rlim_max))
                        return -EFAULT;
        }
        return ret;
}

int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru)
{
        if (!access_ok(VERIFY_WRITE, ru, sizeof(*ru)) ||
            __put_user(r->ru_utime.tv_sec, &ru->ru_utime.tv_sec) ||
            __put_user(r->ru_utime.tv_usec, &ru->ru_utime.tv_usec) ||
            __put_user(r->ru_stime.tv_sec, &ru->ru_stime.tv_sec) ||
            __put_user(r->ru_stime.tv_usec, &ru->ru_stime.tv_usec) ||
            __put_user(r->ru_maxrss, &ru->ru_maxrss) ||
            __put_user(r->ru_ixrss, &ru->ru_ixrss) ||
            __put_user(r->ru_idrss, &ru->ru_idrss) ||
            __put_user(r->ru_isrss, &ru->ru_isrss) ||
            __put_user(r->ru_minflt, &ru->ru_minflt) ||
            __put_user(r->ru_majflt, &ru->ru_majflt) ||
            __put_user(r->ru_nswap, &ru->ru_nswap) ||
            __put_user(r->ru_inblock, &ru->ru_inblock) ||
            __put_user(r->ru_oublock, &ru->ru_oublock) ||
            __put_user(r->ru_msgsnd, &ru->ru_msgsnd) ||
            __put_user(r->ru_msgrcv, &ru->ru_msgrcv) ||
            __put_user(r->ru_nsignals, &ru->ru_nsignals) ||
            __put_user(r->ru_nvcsw, &ru->ru_nvcsw) ||
            __put_user(r->ru_nivcsw, &ru->ru_nivcsw))
                return -EFAULT;
        return 0;
}

COMPAT_SYSCALL_DEFINE4(wait4,
        compat_pid_t, pid,
        compat_uint_t __user *, stat_addr,
        int, options,
        struct compat_rusage __user *, ru)
{
        if (!ru) {
                return sys_wait4(pid, stat_addr, options, NULL);
        } else {
                struct rusage r;
                int ret;
                unsigned int status;
                mm_segment_t old_fs = get_fs();

                set_fs (KERNEL_DS);
                ret = sys_wait4(pid,
                                (stat_addr ?
                                 (unsigned int __user *) &status : NULL),
                                options, (struct rusage __user *) &r);
                set_fs (old_fs);

                if (ret > 0) {
                        if (put_compat_rusage(&r, ru))
                                return -EFAULT;
                        if (stat_addr && put_user(status, stat_addr))
                                return -EFAULT;
                }
                return ret;
        }
}

COMPAT_SYSCALL_DEFINE5(waitid,
                int, which, compat_pid_t, pid,
                struct compat_siginfo __user *, uinfo, int, options,
                struct compat_rusage __user *, uru)
{
        siginfo_t info;
        struct rusage ru;
        long ret;
        mm_segment_t old_fs = get_fs();

        memset(&info, 0, sizeof(info));

        set_fs(KERNEL_DS);
        ret = sys_waitid(which, pid, (siginfo_t __user *)&info, options,
                         uru ? (struct rusage __user *)&ru : NULL);
        set_fs(old_fs);

        if ((ret < 0) || (info.si_signo == 0))
                return ret;

        if (uru) {
                /* sys_waitid() overwrites everything in ru */
                if (COMPAT_USE_64BIT_TIME)
                        ret = copy_to_user(uru, &ru, sizeof(ru));
                else
                        ret = put_compat_rusage(&ru, uru);
                if (ret)
                        return -EFAULT;
        }

        BUG_ON(info.si_code & __SI_MASK);
        info.si_code |= __SI_CHLD;
        return copy_siginfo_to_user32(uinfo, &info);
}

static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr,
                                    unsigned len, struct cpumask *new_mask)
{
        unsigned long *k;

        if (len < cpumask_size())
                memset(new_mask, 0, cpumask_size());
        else if (len > cpumask_size())
                len = cpumask_size();

        k = cpumask_bits(new_mask);
        return compat_get_bitmap(k, user_mask_ptr, len * 8);
}

COMPAT_SYSCALL_DEFINE3(sched_setaffinity, compat_pid_t, pid,
                       unsigned int, len,
                       compat_ulong_t __user *, user_mask_ptr)
{
        cpumask_var_t new_mask;
        int retval;

        if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
                return -ENOMEM;

        retval = compat_get_user_cpu_mask(user_mask_ptr, len, new_mask);
        if (retval)
                goto out;

        retval = sched_setaffinity(pid, new_mask);
out:
        free_cpumask_var(new_mask);
        return retval;
}

COMPAT_SYSCALL_DEFINE3(sched_getaffinity, compat_pid_t,  pid, unsigned int, len,
                       compat_ulong_t __user *, user_mask_ptr)
{
        int ret;
        cpumask_var_t mask;

        if ((len * BITS_PER_BYTE) < nr_cpu_ids)
                return -EINVAL;
        if (len & (sizeof(compat_ulong_t)-1))
                return -EINVAL;

        if (!alloc_cpumask_var(&mask, GFP_KERNEL))
                return -ENOMEM;

        ret = sched_getaffinity(pid, mask);
        if (ret == 0) {
                size_t retlen = min_t(size_t, len, cpumask_size());

                if (compat_put_bitmap(user_mask_ptr, cpumask_bits(mask), retlen * 8))
                        ret = -EFAULT;
                else
                        ret = retlen;
        }
        free_cpumask_var(mask);

        return ret;
}

int get_compat_itimerspec(struct itimerspec *dst,
                          const struct compat_itimerspec __user *src)
{
        if (__compat_get_timespec(&dst->it_interval, &src->it_interval) ||
            __compat_get_timespec(&dst->it_value, &src->it_value))
                return -EFAULT;
        return 0;
}

int put_compat_itimerspec(struct compat_itimerspec __user *dst,
                          const struct itimerspec *src)
{
        if (__compat_put_timespec(&src->it_interval, &dst->it_interval) ||
            __compat_put_timespec(&src->it_value, &dst->it_value))
                return -EFAULT;
        return 0;
}

COMPAT_SYSCALL_DEFINE3(timer_create, clockid_t, which_clock,
                       struct compat_sigevent __user *, timer_event_spec,
                       timer_t __user *, created_timer_id)
{
        struct sigevent __user *event = NULL;

        if (timer_event_spec) {
                struct sigevent kevent;

                event = compat_alloc_user_space(sizeof(*event));
                if (get_compat_sigevent(&kevent, timer_event_spec) ||
                    copy_to_user(event, &kevent, sizeof(*event)))
                        return -EFAULT;
        }

        return sys_timer_create(which_clock, event, created_timer_id);
}

COMPAT_SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
                       struct compat_itimerspec __user *, new,
                       struct compat_itimerspec __user *, old)
{
        long err;
        mm_segment_t oldfs;
        struct itimerspec newts, oldts;

        if (!new)
                return -EINVAL;
        if (get_compat_itimerspec(&newts, new))
                return -EFAULT;
        oldfs = get_fs();
        set_fs(KERNEL_DS);
        err = sys_timer_settime(timer_id, flags,
                                (struct itimerspec __user *) &newts,
                                (struct itimerspec __user *) &oldts);
        set_fs(oldfs);
        if (!err && old && put_compat_itimerspec(old, &oldts))
                return -EFAULT;
        return err;
}

COMPAT_SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
                       struct compat_itimerspec __user *, setting)
{
        long err;
        mm_segment_t oldfs;
        struct itimerspec ts;

        oldfs = get_fs();
        set_fs(KERNEL_DS);
        err = sys_timer_gettime(timer_id,
                                (struct itimerspec __user *) &ts);
        set_fs(oldfs);
        if (!err && put_compat_itimerspec(setting, &ts))
                return -EFAULT;
        return err;
}

COMPAT_SYSCALL_DEFINE2(clock_settime, clockid_t, which_clock,
                       struct compat_timespec __user *, tp)
{
        long err;
        mm_segment_t oldfs;
        struct timespec ts;

        if (compat_get_timespec(&ts, tp))
                return -EFAULT;
        oldfs = get_fs();
        set_fs(KERNEL_DS);
        err = sys_clock_settime(which_clock,
                                (struct timespec __user *) &ts);
        set_fs(oldfs);
        return err;
}

COMPAT_SYSCALL_DEFINE2(clock_gettime, clockid_t, which_clock,
                       struct compat_timespec __user *, tp)
{
        long err;
        mm_segment_t oldfs;
        struct timespec ts;

        oldfs = get_fs();
        set_fs(KERNEL_DS);
        err = sys_clock_gettime(which_clock,
                                (struct timespec __user *) &ts);
        set_fs(oldfs);
        if (!err && compat_put_timespec(&ts, tp))
                return -EFAULT;
        return err;
}

COMPAT_SYSCALL_DEFINE2(clock_adjtime, clockid_t, which_clock,
                       struct compat_timex __user *, utp)
{
        struct timex txc;
        mm_segment_t oldfs;
        int err, ret;

        err = compat_get_timex(&txc, utp);
        if (err)
                return err;

        oldfs = get_fs();
        set_fs(KERNEL_DS);
        ret = sys_clock_adjtime(which_clock, (struct timex __user *) &txc);
        set_fs(oldfs);

        err = compat_put_timex(utp, &txc);
        if (err)
                return err;

        return ret;
}

COMPAT_SYSCALL_DEFINE2(clock_getres, clockid_t, which_clock,
                       struct compat_timespec __user *, tp)
{
        long err;
        mm_segment_t oldfs;
        struct timespec ts;

        oldfs = get_fs();
        set_fs(KERNEL_DS);
        err = sys_clock_getres(which_clock,
                               (struct timespec __user *) &ts);
        set_fs(oldfs);
        if (!err && tp && compat_put_timespec(&ts, tp))
                return -EFAULT;
        return err;
}

static long compat_clock_nanosleep_restart(struct restart_block *restart)
{
        long err;
        mm_segment_t oldfs;
        struct timespec tu;
        struct compat_timespec __user *rmtp = restart->nanosleep.compat_rmtp;

        restart->nanosleep.rmtp = (struct timespec __user *) &tu;
        oldfs = get_fs();
        set_fs(KERNEL_DS);
        err = clock_nanosleep_restart(restart);
        set_fs(oldfs);

        if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
            compat_put_timespec(&tu, rmtp))
                return -EFAULT;

        if (err == -ERESTART_RESTARTBLOCK) {
                restart->fn = compat_clock_nanosleep_restart;
                restart->nanosleep.compat_rmtp = rmtp;
        }
        return err;
}

COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
                       struct compat_timespec __user *, rqtp,
                       struct compat_timespec __user *, rmtp)
{
        long err;
        mm_segment_t oldfs;
        struct timespec in, out;
        struct restart_block *restart;

        if (compat_get_timespec(&in, rqtp))
                return -EFAULT;

        oldfs = get_fs();
        set_fs(KERNEL_DS);
        err = sys_clock_nanosleep(which_clock, flags,
                                  (struct timespec __user *) &in,
                                  (struct timespec __user *) &out);
        set_fs(oldfs);

        if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
            compat_put_timespec(&out, rmtp))
                return -EFAULT;

        if (err == -ERESTART_RESTARTBLOCK) {
                restart = &current->restart_block;
                restart->fn = compat_clock_nanosleep_restart;
                restart->nanosleep.compat_rmtp = rmtp;
        }
        return err;
}

/*
 * We currently only need the following fields from the sigevent
 * structure: sigev_value, sigev_signo, sig_notify and (sometimes
 * sigev_notify_thread_id).  The others are handled in user mode.
 * We also assume that copying sigev_value.sival_int is sufficient
 * to keep all the bits of sigev_value.sival_ptr intact.
 */
int get_compat_sigevent(struct sigevent *event,
                const struct compat_sigevent __user *u_event)
{
        memset(event, 0, sizeof(*event));
        return (!access_ok(VERIFY_READ, u_event, sizeof(*u_event)) ||
                __get_user(event->sigev_value.sival_int,
                        &u_event->sigev_value.sival_int) ||
                __get_user(event->sigev_signo, &u_event->sigev_signo) ||
                __get_user(event->sigev_notify, &u_event->sigev_notify) ||
                __get_user(event->sigev_notify_thread_id,
                        &u_event->sigev_notify_thread_id))
                ? -EFAULT : 0;
}

long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
                       unsigned long bitmap_size)
{
        int i, j;
        unsigned long m;
        compat_ulong_t um;
        unsigned long nr_compat_longs;

        /* align bitmap up to nearest compat_long_t boundary */
        bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);

        if (!access_ok(VERIFY_READ, umask, bitmap_size / 8))
                return -EFAULT;

        nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);

        for (i = 0; i < BITS_TO_LONGS(bitmap_size); i++) {
                m = 0;

                for (j = 0; j < sizeof(m)/sizeof(um); j++) {
                        /*
                         * We dont want to read past the end of the userspace
                         * bitmap. We must however ensure the end of the
                         * kernel bitmap is zeroed.
                         */
                        if (nr_compat_longs) {
                                nr_compat_longs--;
                                if (__get_user(um, umask))
                                        return -EFAULT;
                        } else {
                                um = 0;
                        }

                        umask++;
                        m |= (long)um << (j * BITS_PER_COMPAT_LONG);
                }
                *mask++ = m;
        }

        return 0;
}

long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
                       unsigned long bitmap_size)
{
        int i, j;
        unsigned long m;
        compat_ulong_t um;
        unsigned long nr_compat_longs;

        /* align bitmap up to nearest compat_long_t boundary */
        bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);

        if (!access_ok(VERIFY_WRITE, umask, bitmap_size / 8))
                return -EFAULT;

        nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);

        for (i = 0; i < BITS_TO_LONGS(bitmap_size); i++) {
                m = *mask++;

                for (j = 0; j < sizeof(m)/sizeof(um); j++) {
                        um = m;

                        /*
                         * We dont want to write past the end of the userspace
                         * bitmap.
                         */
                        if (nr_compat_longs) {
                                nr_compat_longs--;
                                if (__put_user(um, umask))
                                        return -EFAULT;
                        }

                        umask++;
                        m >>= 4*sizeof(um);
                        m >>= 4*sizeof(um);
                }
        }

        return 0;
}

void
sigset_from_compat(sigset_t *set, const compat_sigset_t *compat)
{
        switch (_NSIG_WORDS) {
        case 4: set->sig[3] = compat->sig[6] | (((long)compat->sig[7]) << 32 );
        case 3: set->sig[2] = compat->sig[4] | (((long)compat->sig[5]) << 32 );
        case 2: set->sig[1] = compat->sig[2] | (((long)compat->sig[3]) << 32 );
        case 1: set->sig[0] = compat->sig[0] | (((long)compat->sig[1]) << 32 );
        }
}
EXPORT_SYMBOL_GPL(sigset_from_compat);

void
sigset_to_compat(compat_sigset_t *compat, const sigset_t *set)
{
        switch (_NSIG_WORDS) {
        case 4: compat->sig[7] = (set->sig[3] >> 32); compat->sig[6] = set->sig[3];
        case 3: compat->sig[5] = (set->sig[2] >> 32); compat->sig[4] = set->sig[2];
        case 2: compat->sig[3] = (set->sig[1] >> 32); compat->sig[2] = set->sig[1];
        case 1: compat->sig[1] = (set->sig[0] >> 32); compat->sig[0] = set->sig[0];
        }
}

COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait, compat_sigset_t __user *, uthese,
                struct compat_siginfo __user *, uinfo,
                struct compat_timespec __user *, uts, compat_size_t, sigsetsize)
{
        compat_sigset_t s32;

        sigset_t s;
        struct timespec t;
        siginfo_t info;
        long ret;

        if (sigsetsize != sizeof(sigset_t))
                return -EINVAL;

        if (copy_from_user(&s32, uthese, sizeof(compat_sigset_t)))
                return -EFAULT;
        sigset_from_compat(&s, &s32);

        if (uts) {
                if (compat_get_timespec(&t, uts))
                        return -EFAULT;
        }

        ret = do_sigtimedwait(&s, &info, uts ? &t : NULL);

        if (ret > 0 && uinfo) {
                if (copy_siginfo_to_user32(uinfo, &info))
                        ret = -EFAULT;
        }

        return ret;
}

#ifdef __ARCH_WANT_COMPAT_SYS_TIME

/* compat_time_t is a 32 bit "long" and needs to get converted. */

COMPAT_SYSCALL_DEFINE1(time, compat_time_t __user *, tloc)
{
        compat_time_t i;
        struct timeval tv;

        do_gettimeofday(&tv);
        i = tv.tv_sec;

        if (tloc) {
                if (put_user(i,tloc))
                        return -EFAULT;
        }
        force_successful_syscall_return();
        return i;
}

COMPAT_SYSCALL_DEFINE1(stime, compat_time_t __user *, tptr)
{
        struct timespec tv;
        int err;

        if (get_user(tv.tv_sec, tptr))
                return -EFAULT;

        tv.tv_nsec = 0;

        err = security_settime(&tv, NULL);
        if (err)
                return err;

        do_settimeofday(&tv);
        return 0;
}

#endif /* __ARCH_WANT_COMPAT_SYS_TIME */

COMPAT_SYSCALL_DEFINE1(adjtimex, struct compat_timex __user *, utp)
{
        struct timex txc;
        int err, ret;

        err = compat_get_timex(&txc, utp);
        if (err)
                return err;

        ret = do_adjtimex(&txc);

        err = compat_put_timex(utp, &txc);
        if (err)
                return err;

        return ret;
}

#ifdef CONFIG_NUMA
COMPAT_SYSCALL_DEFINE6(move_pages, pid_t, pid, compat_ulong_t, nr_pages,
                       compat_uptr_t __user *, pages32,
                       const int __user *, nodes,
                       int __user *, status,
                       int, flags)
{
        const void __user * __user *pages;
        int i;

        pages = compat_alloc_user_space(nr_pages * sizeof(void *));
        for (i = 0; i < nr_pages; i++) {
                compat_uptr_t p;

                if (get_user(p, pages32 + i) ||
                        put_user(compat_ptr(p), pages + i))
                        return -EFAULT;
        }
        return sys_move_pages(pid, nr_pages, pages, nodes, status, flags);
}

COMPAT_SYSCALL_DEFINE4(migrate_pages, compat_pid_t, pid,
                       compat_ulong_t, maxnode,
                       const compat_ulong_t __user *, old_nodes,
                       const compat_ulong_t __user *, new_nodes)
{
        unsigned long __user *old = NULL;
        unsigned long __user *new = NULL;
        nodemask_t tmp_mask;
        unsigned long nr_bits;
        unsigned long size;

        nr_bits = min_t(unsigned long, maxnode - 1, MAX_NUMNODES);
        size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
        if (old_nodes) {
                if (compat_get_bitmap(nodes_addr(tmp_mask), old_nodes, nr_bits))
                        return -EFAULT;
                old = compat_alloc_user_space(new_nodes ? size * 2 : size);
                if (new_nodes)
                        new = old + size / sizeof(unsigned long);
                if (copy_to_user(old, nodes_addr(tmp_mask), size))
                        return -EFAULT;
        }
        if (new_nodes) {
                if (compat_get_bitmap(nodes_addr(tmp_mask), new_nodes, nr_bits))
                        return -EFAULT;
                if (new == NULL)
                        new = compat_alloc_user_space(size);
                if (copy_to_user(new, nodes_addr(tmp_mask), size))
                        return -EFAULT;
        }
        return sys_migrate_pages(pid, nr_bits + 1, old, new);
}
#endif

COMPAT_SYSCALL_DEFINE2(sched_rr_get_interval,
                       compat_pid_t, pid,
                       struct compat_timespec __user *, interval)
{
        struct timespec t;
        int ret;
        mm_segment_t old_fs = get_fs();

        set_fs(KERNEL_DS);
        ret = sys_sched_rr_get_interval(pid, (struct timespec __user *)&t);
        set_fs(old_fs);
        if (compat_put_timespec(&t, interval))
                return -EFAULT;
        return ret;
}

/*
 * Allocate user-space memory for the duration of a single system call,
 * in order to marshall parameters inside a compat thunk.
 */
void __user *compat_alloc_user_space(unsigned long len)
{
        void __user *ptr;

        /* If len would occupy more than half of the entire compat space... */
        if (unlikely(len > (((compat_uptr_t)~0) >> 1)))
                return NULL;

        ptr = arch_compat_alloc_user_space(len);

        if (unlikely(!access_ok(VERIFY_WRITE, ptr, len)))
                return NULL;

        return ptr;
}
EXPORT_SYMBOL_GPL(compat_alloc_user_space);