bc874d174b
Use schedule_timeout_interruptible() instead of set_current_state()/schedule_timeout() to reduce kernel size. Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
127 lines
3.0 KiB
C
127 lines
3.0 KiB
C
/* Copyright (C) 2005 Jeff Dike <jdike@addtoit.com> */
|
|
/* Much of this ripped from drivers/char/hw_random.c, see there for other
|
|
* copyright.
|
|
*
|
|
* This software may be used and distributed according to the terms
|
|
* of the GNU General Public License, incorporated herein by reference.
|
|
*/
|
|
#include <linux/module.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/delay.h>
|
|
#include <asm/uaccess.h>
|
|
#include "os.h"
|
|
|
|
/*
|
|
* core module and version information
|
|
*/
|
|
#define RNG_VERSION "1.0.0"
|
|
#define RNG_MODULE_NAME "random"
|
|
|
|
#define RNG_MISCDEV_MINOR 183 /* official */
|
|
|
|
static int random_fd = -1;
|
|
|
|
static int rng_dev_open (struct inode *inode, struct file *filp)
|
|
{
|
|
/* enforce read-only access to this chrdev */
|
|
if ((filp->f_mode & FMODE_READ) == 0)
|
|
return -EINVAL;
|
|
if (filp->f_mode & FMODE_WRITE)
|
|
return -EINVAL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t rng_dev_read (struct file *filp, char __user *buf, size_t size,
|
|
loff_t * offp)
|
|
{
|
|
u32 data;
|
|
int n, ret = 0, have_data;
|
|
|
|
while(size){
|
|
n = os_read_file(random_fd, &data, sizeof(data));
|
|
if(n > 0){
|
|
have_data = n;
|
|
while (have_data && size) {
|
|
if (put_user((u8)data, buf++)) {
|
|
ret = ret ? : -EFAULT;
|
|
break;
|
|
}
|
|
size--;
|
|
ret++;
|
|
have_data--;
|
|
data>>=8;
|
|
}
|
|
}
|
|
else if(n == -EAGAIN){
|
|
if (filp->f_flags & O_NONBLOCK)
|
|
return ret ? : -EAGAIN;
|
|
|
|
if(need_resched())
|
|
schedule_timeout_interruptible(1);
|
|
}
|
|
else return n;
|
|
if (signal_pending (current))
|
|
return ret ? : -ERESTARTSYS;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static struct file_operations rng_chrdev_ops = {
|
|
.owner = THIS_MODULE,
|
|
.open = rng_dev_open,
|
|
.read = rng_dev_read,
|
|
};
|
|
|
|
static struct miscdevice rng_miscdev = {
|
|
RNG_MISCDEV_MINOR,
|
|
RNG_MODULE_NAME,
|
|
&rng_chrdev_ops,
|
|
};
|
|
|
|
/*
|
|
* rng_init - initialize RNG module
|
|
*/
|
|
static int __init rng_init (void)
|
|
{
|
|
int err;
|
|
|
|
err = os_open_file("/dev/random", of_read(OPENFLAGS()), 0);
|
|
if(err < 0)
|
|
goto out;
|
|
|
|
random_fd = err;
|
|
|
|
err = os_set_fd_block(random_fd, 0);
|
|
if(err)
|
|
goto err_out_cleanup_hw;
|
|
|
|
err = misc_register (&rng_miscdev);
|
|
if (err) {
|
|
printk (KERN_ERR RNG_MODULE_NAME ": misc device register failed\n");
|
|
goto err_out_cleanup_hw;
|
|
}
|
|
|
|
out:
|
|
return err;
|
|
|
|
err_out_cleanup_hw:
|
|
random_fd = -1;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* rng_cleanup - shutdown RNG module
|
|
*/
|
|
static void __exit rng_cleanup (void)
|
|
{
|
|
misc_deregister (&rng_miscdev);
|
|
}
|
|
|
|
module_init (rng_init);
|
|
module_exit (rng_cleanup);
|
|
|
|
MODULE_DESCRIPTION("UML Host Random Number Generator (RNG) driver");
|
|
MODULE_LICENSE("GPL");
|