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  • compat.c 30.48 KiB
    /*
     *  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>
    
    /*
     * Get/set struct timeval with struct timespec on the native side
     */
    static int compat_get_timeval_convert(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_convert(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_convert(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_convert(&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_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;
    }
    EXPORT_SYMBOL_GPL(get_compat_timeval);
    
    int put_compat_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;
    }
    EXPORT_SYMBOL_GPL(put_compat_timeval);
    
    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;
    }
    EXPORT_SYMBOL_GPL(get_compat_timespec);
    
    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;
    }
    EXPORT_SYMBOL_GPL(put_compat_timespec);
    
    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 get_compat_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 put_compat_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 get_compat_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 put_compat_timespec(ts, uts);
    }
    EXPORT_SYMBOL_GPL(compat_put_timespec);
    
    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);
    }
    
    #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().
     */
    
    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;
    }
    
    #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));
    }
    
    asmlinkage long compat_sys_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
    
    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 );
    	}
    }
    EXPORT_SYMBOL_GPL(sigset_from_compat);
    
    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));
    
    	current->saved_sigmask = current->blocked;
    	set_current_blocked(&newset);
    
    	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);