/*
   *  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/times.h>

  #include <linux/ptrace.h>

  #include <linux/gfp.h>

  
  #include <asm/uaccess.h>

  /*
   * Note that the native side is already converted to a timespec, because
   * that's what we want anyway.
   */
  static int compat_get_timeval(struct timespec *o,
  		struct compat_timeval __user *i)
  {
  	long usec;
  
  	if (get_user(o->tv_sec, &i->tv_sec) ||
  	    get_user(usec, &i->tv_usec))
  		return -EFAULT;
  	o->tv_nsec = usec * 1000;
  	return 0;
  }
  
  static int compat_put_timeval(struct compat_timeval __user *o,
  		struct timeval *i)
  {
  	return (put_user(i->tv_sec, &o->tv_sec) ||
  		put_user(i->tv_usec, &o->tv_usec)) ? -EFAULT : 0;
  }

  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;
  }

  asmlinkage long compat_sys_gettimeofday(struct compat_timeval __user *tv,
  		struct timezone __user *tz)
  {
  	if (tv) {
  		struct timeval ktv;
  		do_gettimeofday(&ktv);
  		if (compat_put_timeval(tv, &ktv))
  			return -EFAULT;
  	}
  	if (tz) {
  		if (copy_to_user(tz, &sys_tz, sizeof(sys_tz)))
  			return -EFAULT;
  	}
  
  	return 0;
  }
  
  asmlinkage long compat_sys_settimeofday(struct compat_timeval __user *tv,
  		struct timezone __user *tz)
  {
  	struct timespec kts;
  	struct timezone ktz;
  
  	if (tv) {
  		if (compat_get_timeval(&kts, tv))
  			return -EFAULT;
  	}
  	if (tz) {
  		if (copy_from_user(&ktz, tz, sizeof(ktz)))
  			return -EFAULT;
  	}
  
  	return do_sys_settimeofday(tv ? &kts : NULL, tz ? &ktz : NULL);
  }

  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;
  }

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

  asmlinkage long compat_sys_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);
  }
  
  /*
   * 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;

  
  	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
  
  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;

  	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;
  }
  
  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, 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);
  }
  
  asmlinkage long compat_sys_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;

  }
  
  asmlinkage long compat_sys_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 (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_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;
  }

  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;

  	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 (get_compat_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;
  
  }

  asmlinkage long
  compat_sys_rt_tgsigqueueinfo(compat_pid_t tgid, compat_pid_t pid, int sig,
  			     struct compat_siginfo __user *uinfo)
  {
  	siginfo_t info;
  
  	if (copy_siginfo_from_user32(&info, uinfo))
  		return -EFAULT;
  	return do_rt_tgsigqueueinfo(tgid, pid, sig, &info);
  }

  #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))

  			return -EFAULT;

  	}

  	force_successful_syscall_return();

  	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 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
  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);