/*
   *  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_thread_info()->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_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, 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);