Messages in this thread | | | Date | Thu, 26 Jan 2012 18:34:44 +0100 | From | Sascha Hauer <> | Subject | Re: [alsa-devel] [PATCH 1/7 v2] dmaengine: add a simple dma library |
| |
Hi Guennadi,
On Thu, Jan 26, 2012 at 03:56:18PM +0100, Guennadi Liakhovetski wrote: > This patch adds a library of functions, helping to implement dmaengine > drivers for hardware, unable to handle scatter-gather lists natively. > The first version of this driver only supports memcpy and slave DMA > operation. > > Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> > --- >
[...]
> + > +/* > + * For slave DMA we assume, that there is a finite number of DMA slaves in the > + * system, and that each such slave can only use a finite number of channels. > + * We use slave channel IDs to make sure, that no such slave channel ID is > + * allocated more than once. > + */ > +static unsigned int slave_num = 256; > +module_param(slave_num, uint, 0444); > + > +/* A bitmask with slave_num bits */ > +static unsigned long *simple_slave_used;
You never check that the slave ids passed into this code are within the range of slave_num. Given that this is a user changeable value this is a bit flawy.
Sascha
-- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
| |