From: Ralph Wuerthner Date: Thu, 17 Apr 2008 05:46:14 +0000 (+0200) Subject: [S390] hw_random: allow rng_dev_read() to return hardware errors. X-Git-Tag: v2.6.26-rc1~1158^2~17 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=893f11286644780fc7d6d415e537644da7bdaaf8;p=linux-2.6 [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 Signed-off-by: Martin Schwidefsky Signed-off-by: Heiko Carstens --- diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index 84cdf90257..349b6edc57 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -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) {