path: root/kernel/compat.c

/*
 *  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 <asm/uaccess.h>

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

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

static long compat_nanosleep_restart(struct restart_block *restart)
{
	unsigned long expire = restart->arg0, now = jiffies;
	struct compat_timespec __user *rmtp;

	/* Did it expire while we handled signals? */
	if (!time_after(expire, now))
		return 0;

	expire = schedule_timeout_interruptible(expire - now);
	if (expire == 0)
		return 0;

	rmtp = (struct compat_timespec __user *)restart->arg1;
	if (rmtp) {
		struct compat_timespec ct;
		struct timespec t;

		jiffies_to_timespec(expire, &t);
		ct.tv_sec = t.tv_sec;
		ct.tv_nsec = t.tv_nsec;
		if (copy_to_user(rmtp, &ct, sizeof(ct)))
			return -EFAULT;
	}
	/* The 'restart' block is already filled in */
	return -ERESTART_RESTARTBLOCK;
}

asmlinkage long compat_sys_nanosleep(struct compat_timespec __user *rqtp,
		struct compat_timespec __user *rmtp)
{
	struct timespec t;
	struct restart_block *restart;
	unsigned long expire;

	if (get_compat_timespec(&t, rqtp))
		return -EFAULT;

	if ((t.tv_nsec >= 1000000000L) || (t.tv_nsec < 0) || (t.tv_sec < 0))
		return -EINVAL;

	expire = timespec_to_jiffies(&t) + (t.tv_sec || t.tv_nsec);
	expire = schedule_timeout_interruptible(expire);
	if (expire == 0)
		return 0;

	if (rmtp) {
		jiffies_to_timespec(expire, &t);
		if (put_compat_timespec(&t, rmtp))
			return -EFAULT;
	}
	restart = &current_thread_info()->restart_block;
	restart->fn = compat_nanosleep_restart;
	restart->arg0 = jiffies + expire;
	restart->arg1 = (unsigned long) rmtp;
	return -ERESTART_RESTARTBLOCK;
}

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)) ||
		(