/*
 *  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/migrate.h>
#include <linux/posix-timers.h>
#include <linux/module.h>

#include <asm/uaccess.h>

int get_compat_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;
}

int put_compat_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;
}

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) {
                rmtp = restart->nanosleep.compat_rmtp;

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

        return ret;
}

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

        if (get_compat_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);

        if (ret) {
                struct restart_block *restart
                        = &current_thread_info()->restart_block;

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

                if (rmtp && put_compat_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)));
}

asmlinkage long compat_sys_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;
}

asmlinkage long compat_sys_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;
}

asmlinkage long compat_sys_times(struct compat_tms __user *tbuf)
{
        /*
         *      In the SMP world we might just be unlucky and have one of
         *      the times increment as we use it. Since the value is an
         *      atomically safe type this is just fine. Conceptually its
         *      as if the syscall took an instant longer to occur.
         */
        if (tbuf) {
                struct compat_tms tmp;
                struct task_struct *tsk = current;
                struct task_struct *t;
                cputime_t utime, stime, cutime, cstime;

                read_lock(&tasklist_lock);
                utime = tsk->signal->utime;
                stime = tsk->signal->stime;
                t = tsk;
                do {
                        utime = cputime_add(utime, t->utime);
                        stime = cputime_add(stime, t->stime);
                        t = next_thread(t);
                } while (t != tsk);

                /*
                 * While we have tasklist_lock read-locked, no dying thread
                 * can be updating current->signal->[us]time.  Instead,
                 * we got their counts included in the live thread loop.
                 * However, another thread can come in right now and
                 * do a wait call that updates current->signal->c[us]time.
                 * To make sure we always see that pair updated atomically,
                 * we take the siglock around fetching them.
                 */
                spin_lock_irq(&tsk->sighand->siglock);
                cutime = tsk->signal->cutime;
                cstime = tsk->signal->cstime;
                spin_unlock_irq(&tsk->sighand->siglock);
                read_unlock(&tasklist_lock);

                tmp.tms_utime = compat_jiffies_to_clock_t(cputime_to_jiffies(utime));
                tmp.tms_stime = compat_jiffies_to_clock_t(cputime_to_jiffies(stime));
                tmp.tms_cutime = compat_jiffies_to_clock_t(cputime_to_jiffies(cutime));
                tmp.tms_cstime = compat_jiffies_to_clock_t(cputime_to_jiffies(cstime));
                if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
                        return -EFAULT;
        }
        return compat_jiffies_to_clock_t(jiffies);
}

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

asmlinkage long compat_sys_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;
}

asmlinkage long compat_sys_sigprocmask(int how, compat_old_sigset_t __user *set,
                compat_old_sigset_t __user *oset)
{
        old_sigset_t s;
        long ret;
        mm_segment_t old_fs;

        if (set && get_user(s, set))
                return -EFAULT;
        old_fs = get_fs();
        set_fs(KERNEL_DS);
        ret = sys_sigprocmask(how,
                              set ? (old_sigset_t __user *) &s : NULL,
                              oset ? (old_sigset_t __user *) &s : NULL);
        set_fs(old_fs);
        if (ret == 0)
                if (oset)
                        ret = put_user(s, oset);
        return ret;
}

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

        if (resource >= RLIM_NLIMITS)
                return -EINVAL;

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

#ifdef COMPAT_RLIM_OLD_INFINITY

asmlinkage long compat_sys_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, &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

asmlinkage long compat_sys_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_getrlimit(resource, (struct rlimit __user *) &r);
        set_fs(old_fs);
        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;
}

asmlinkage long compat_sys_getrusage(int who, struct compat_rusage __user *ru)
{
        struct rusage r;
        int ret;
        mm_segment_t old_fs = get_fs();

        set_fs(KERNEL_DS);
        ret = sys_getrusage(who, (struct rusage __user *) &r);
        set_fs(old_fs);

        if (ret)
                return ret;

        if (put_compat_rusage(&r, ru))
                return -EFAULT;

        return 0;
}

asmlinkage long
compat_sys_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;
        }
}

asmlinkage long compat_sys_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) {
                ret = put_compat_rusage(&ru, uru);
                if (ret)
                        return ret;
        }

        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, cpumask_t *new_mask)
{
        unsigned long *k;

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

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

asmlinkage long compat_sys_sched_setaffinity(compat_pid_t pid,
                                             unsigned int len,
                                             compat_ulong_t __user *user_mask_ptr)
{
        cpumask_t new_mask;
        int retval;

        retval = compat_get_user_cpu_mask(user_mask_ptr, len, &new_mask);
        if (retval)
                return retval;

        return sched_setaffinity(pid, &new_mask);
}

asmlinkage long compat_sys_sched_getaffinity(compat_pid_t pid, unsigned int len,
                                             compat_ulong_t __user *user_mask_ptr)
{
        int ret;
        cpumask_t mask;
        unsigned long *k;
        unsigned int min_length = sizeof(cpumask_t);

        if (NR_CPUS <= BITS_PER_COMPAT_LONG)
                min_length = sizeof(compat_ulong_t);

        if (len < min_length)
                return -EINVAL;

        ret = sched_getaffinity(pid, &mask);
        if (ret < 0)
                return ret;

        k = cpus_addr(mask);
        ret = compat_put_bitmap(user_mask_ptr, k, min_length * 8);
        if (ret)
                return ret;

        return min_length;
}

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

long compat_sys_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);
}

long compat_sys_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;
}

long compat_sys_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;
}

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

        if (get_compat_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;
}

long compat_sys_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 && put_compat_timespec(&ts, tp))
                return -EFAULT;
        return err;
}

long compat_sys_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 && put_compat_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 *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 &&
            put_compat_timespec(&tu, rmtp))
                return -EFAULT;

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

long compat_sys_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 (get_compat_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 &&
            put_compat_timespec(&out, rmtp))
                return -EFAULT;

        if (err == -ERESTART_RESTARTBLOCK) {
                restart = &current_thread_info()->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-- > 0) {
                                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-- > 0) {
                                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, 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 );
        }
}

asmlinkage long
compat_sys_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;
        int sig;
        struct timespec t;
        siginfo_t info;
        long ret, timeout = 0;

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

        if (copy_from_user(&s32, uthese, sizeof(compat_sigset_t)))
                return -EFAULT;
        sigset_from_compat(&s, &s32);
        sigdelsetmask(&s,sigmask(SIGKILL)|sigmask(SIGSTOP));
        signotset(&s);

        if (uts) {
                if (get_compat_timespec (&t, uts))
                        return -EFAULT;
                if (t.tv_nsec >= 1000000000L || t.tv_nsec < 0
                                || t.tv_sec < 0)
                        return -EINVAL;
        }

        spin_lock_irq(&current->sighand->siglock);
        sig = dequeue_signal(current, &s, &info);
        if (!sig) {
                timeout = MAX_SCHEDULE_TIMEOUT;
                if (uts)
                        timeout = timespec_to_jiffies(&t)
                                +(t.tv_sec || t.tv_nsec);
                if (timeout) {
                        current->real_blocked = current->blocked;
                        sigandsets(&current->blocked, &current->blocked, &s);

                        recalc_sigpending();
                        spin_unlock_irq(&current->sighand->siglock);

                        timeout = schedule_timeout_interruptible(timeout);

                        spin_lock_irq(&current->sighand->siglock);
                        sig = dequeue_signal(current, &s, &info);
                        current->blocked = current->real_blocked;
                        siginitset(&current->real_blocked, 0);
                        recalc_sigpending();
                }
        }
        spin_unlock_irq(&current->sighand->siglock);

        if (sig) {
                ret = sig;
                if (uinfo) {
                        if (copy_siginfo_to_user32(uinfo, &info))
                                ret = -EFAULT;
                }
        }else {
                ret = timeout?-EINTR:-EAGAIN;
        }
        return ret;

}

#ifdef __ARCH_WANT_COMPAT_SYS_TIME

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

asmlinkage long compat_sys_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))
                        i = -EFAULT;
        }
        return i;
}

asmlinkage long compat_sys_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 */

#ifdef __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND
asmlinkage long compat_sys_rt_sigsuspend(compat_sigset_t __user *unewset, compat_size_t sigsetsize)
{
        sigset_t newset;
        compat_sigset_t newset32;

        /* XXX: Don't preclude handling different sized sigset_t's.  */
        if (sigsetsize != sizeof(sigset_t))
                return -EINVAL;

        if (copy_from_user(&newset32, unewset, sizeof(compat_sigset_t)))
                return -EFAULT;
        sigset_from_compat(&newset, &newset32);
        sigdelsetmask(&newset, sigmask(SIGKILL)|sigmask(SIGSTOP));

        spin_lock_irq(&current->sighand->siglock);
        current->saved_sigmask = current->blocked;
        current->blocked = newset;
        recalc_sigpending();
        spin_unlock_irq(&current->sighand->siglock);

        current->state = TASK_INTERRUPTIBLE;
        schedule();
        set_restore_sigmask();
        return -ERESTARTNOHAND;
}
#endif /* __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND */

asmlinkage long compat_sys_adjtimex(struct compat_timex __user *utp)
{
        struct timex txc;
        int ret;

        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;

        ret = do_adjtimex(&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))
                ret = -EFAULT;

        return ret;
}

#ifdef CONFIG_NUMA
asmlinkage long compat_sys_move_pages(pid_t pid, unsigned long 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);
}

asmlinkage long compat_sys_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

struct compat_sysinfo {
        s32 uptime;
        u32 loads[3];
        u32 totalram;
        u32 freeram;
        u32 sharedram;
        u32 bufferram;
        u32 totalswap;
        u32 freeswap;
        u16 procs;
        u16 pad;
        u32 totalhigh;
        u32 freehigh;
        u32 mem_unit;
        char _f[20-2*sizeof(u32)-sizeof(int)];
};

asmlinkage long
compat_sys_sysinfo(struct compat_sysinfo __user *info)
{
        struct sysinfo s;

        do_sysinfo(&s);

        /* Check to see if any memory value is too large for 32-bit and scale
         *  down if needed
         */
        if ((s.totalram >> 32) || (s.totalswap >> 32)) {
                int bitcount = 0;

                while (s.mem_unit < PAGE_SIZE) {
                        s.mem_unit <<= 1;
                        bitcount++;
                }

                s.totalram >>= bitcount;
                s.freeram >>= bitcount;
                s.sharedram >>= bitcount;
                s.bufferram >>= bitcount;
                s.totalswap >>= bitcount;
                s.freeswap >>= bitcount;
                s.totalhigh >>= bitcount;
                s.freehigh >>= bitcount;
        }

        if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) ||
            __put_user (s.uptime, &info->uptime) ||
            __put_user (s.loads[0], &info->loads[0]) ||
            __put_user (s.loads[1], &info->loads[1]) ||
            __put_user (s.loads[2], &info->loads[2]) ||
            __put_user (s.totalram, &info->totalram) ||
            __put_user (s.freeram, &info->freeram) ||
            __put_user (s.sharedram, &info->sharedram) ||
            __put_user (s.bufferram, &info->bufferram) ||
            __put_user (s.totalswap, &info->totalswap) ||
            __put_user (s.freeswap, &info->freeswap) ||
            __put_user (s.procs, &info->procs) ||
            __put_user (s.totalhigh, &info->totalhigh) ||
            __put_user (s.freehigh, &info->freehigh) ||
            __put_user (s.mem_unit, &info->mem_unit))
                return -EFAULT;

        return 0;
}

/*
 * 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);