Commit 893f1128 authored Apr 17, 2008 by Ralph Wuerthner Committed by Heiko Carstens Apr 17, 2008

[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>

parent c10fde0d

drivers/char/hw_random/core.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -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) {

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