[S390] hw_random: allow rng_dev_read() to return hardware errors.

The api for hardware random number generators is currently limited to
devices that never fail. If the hardware is registered as a source for
random numbers it has to work. This prevents the use of i/o based
random number devices where the i/o might fail.

Add a check for errors after the read from a hardware random number device.

This patch is required to support large random numbers retrieved
from the CEX2C cards on System z.

Signed-off-by: Ralph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
This commit is contained in:
Ralph Wuerthner 2008-04-17 07:46:14 +02:00 committed by Heiko Carstens
parent c10fde0d9e
commit 893f112866

View file

@ -116,6 +116,10 @@ static ssize_t rng_dev_read(struct file *filp, char __user *buf,
err = -EAGAIN;
if (!bytes_read && (filp->f_flags & O_NONBLOCK))
goto out;
if (bytes_read < 0) {
err = bytes_read;
goto out;
}
err = -EFAULT;
while (bytes_read && size) {