From: Ralph Wuerthner 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 --- drivers/char/hw_random/core.c | 4 ++++ 1 file changed, 4 insertions(+) Index: quilt-2.6/drivers/char/hw_random/core.c =================================================================== --- quilt-2.6.orig/drivers/char/hw_random/core.c +++ quilt-2.6/drivers/char/hw_random/core.c @@ -116,6 +116,10 @@ static ssize_t rng_dev_read(struct file 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) { -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/