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)
{
	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.