[U-Boot] [PATCH] mtd: pxa3xx_nand: Correct allocation and init bug

[Scott Wood]

On Fri, 2015-10-23 at 17:49 +0000, Kevin Smith wrote:
> Correct a null pointer dereference in board_nand_init().  Zeroed
> memory was allocated, then immediately dereferenced, which is a
> null dereference.  The dereference is completely removed, since
> this pointer is later initialized in alloc_nand_resources.
> 
> The allocation size is reduced from what was introduced from the
> Linux kernel, as U-boot uses the statically allocated nand_info
> instead of needing to dynamically allocate an mtd_info instance.
> 
> Also, some pointer math was corrected in the initialization of
> the nand_chip pointer.
> 
> Signed-off-by: Kevin Smith <kevin.smith at elecsyscorp.com>
> Cc: Stefan Roese <sr at denx.de>
> Cc: Luka Perkov <luka.perkov at sartura.hr>
> Cc: Scott Wood <scottwood at freescale.com>
> ---
>  drivers/mtd/nand/pxa3xx_nand.c | 17 +++++------------
>  1 file changed, 5 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c
> index 1565a9a..e5ea5c2 100644
> --- a/drivers/mtd/nand/pxa3xx_nand.c
> +++ b/drivers/mtd/nand/pxa3xx_nand.c
> @@ -1486,8 +1486,8 @@ static int alloc_nand_resource(struct 
> pxa3xx_nand_info *info)
>       info->variant = pxa3xx_nand_get_variant();
>       for (cs = 0; cs < pdata->num_cs; cs++) {
>               mtd = &nand_info[cs];
> -             chip = (struct nand_chip *)info +
> -                     sizeof(struct pxa3xx_nand_host);
> +             chip = (struct nand_chip *)
> +                     ((u8 *)&info[1] + sizeof(*host) * cs);

Yuck.  Could you please rework this driver to not play games with pointers 
and one giant allocation?  Why can't this function allocate each region it 
needs separately?

-Scott