[PATCH v5 5/8] sandbox: rng: Add a random number generator(rng) driver

[Sughosh Ganu]

On Fri, 27 Dec 2019 at 12:29, Heinrich Schuchardt <xypron.glpk at gmx.de>
wrote:

> On 12/26/19 6:25 PM, Sughosh Ganu wrote:
> > Add a sandbox driver for random number generation. Mostly aimed at
> > providing a unit test for rng uclass.
> >
> > Signed-off-by: Sughosh Ganu <sughosh.ganu at linaro.org>
> > Reviewed-by: Patrice Chotard <patrice.chotard at st.com>
> > ---
> > Changes since V4:
> > * Return number of bytes read on a successful read, and a -ve value on
> >    error.
> > * Modify the logic of sandbox_rng_read function to use rand and srand
> >    functions to return random data, based on feedback from Heinrich
> >    Schuchardt.
> >
> >   arch/sandbox/dts/test.dts |  4 ++++
> >   drivers/rng/Kconfig       |  8 +++++++
> >   drivers/rng/Makefile      |  1 +
> >   drivers/rng/sandbox_rng.c | 56
> +++++++++++++++++++++++++++++++++++++++++++++++
> >   4 files changed, 69 insertions(+)
> >   create mode 100644 drivers/rng/sandbox_rng.c
> >
>

<snip>

> diff --git a/drivers/rng/sandbox_rng.c b/drivers/rng/sandbox_rng.c
> > new file mode 100644
> > index 0000000..5de1799
> > --- /dev/null
> > +++ b/drivers/rng/sandbox_rng.c
> > @@ -0,0 +1,56 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * Copyright (c) 2019, Linaro Limited
> > + */
> > +
> > +#include <common.h>
> > +#include <dm.h>
> > +#include <rng.h>
> > +
> > +#include <linux/string.h>
> > +
> > +static int sandbox_rng_read(struct udevice *dev, void *data, size_t len)
> > +{
> > +     int nbytes;
> > +     unsigned int i, seed;
> > +     unsigned int *buf = data;
>
> You assume here that data is 4 byte aligned which may not hold true and
> hence may lead to a crash on ARM.
>

Will fix.

-sughosh