1 files changed, 122 insertions, 0 deletions
diff --git a/arch/um/drivers/random.c b/arch/um/drivers/random.c
new file mode 100644
index 000000000000..d43e9fab05a7
--- /dev/null
+++ b/arch/um/drivers/random.c
@@ -0,0 +1,122 @@
+/* Much of this ripped from hw_random.c */
+
+#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_DRIVER_NAME   RNG_MODULE_NAME " virtual driver " RNG_VERSION
+#define PFX RNG_MODULE_NAME ": "
+
+#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()){
+                                current->state = TASK_INTERRUPTIBLE;
+                                schedule_timeout(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 PFX "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);