Re: [PATCH v1 3/5] mtd: rawnand: meson: check buffer length

[Miquel Raynal <miquel.raynal@bootlin.com>]

Hi Arseniy,

AVKrasnov@sberdevices.ru wrote on Wed, 12 Apr 2023 09:16:57 +0300:

> With this chip, buffer length is limited by hardware, so check it before
> command execution to avoid length trim.

What is "this chip"? Are you talking about the controller itself? Is
there any specific SoC version targeted?

> 
> Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
> ---
>  drivers/mtd/nand/raw/meson_nand.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
> index 45b53d420aed..f84a10238e4d 100644
> --- a/drivers/mtd/nand/raw/meson_nand.c
> +++ b/drivers/mtd/nand/raw/meson_nand.c
> @@ -543,6 +543,9 @@ static int meson_nfc_read_buf(struct nand_chip *nand, u8 *buf, int len)
>  	u32 cmd;
>  	u8 *info;
>  
> +	if (len > NFC_CMD_RAW_LEN)
> +		return -EINVAL;
> +
>  	info = kzalloc(PER_INFO_BYTE, GFP_KERNEL);
>  	if (!info)
>  		return -ENOMEM;
> @@ -571,6 +574,9 @@ static int meson_nfc_write_buf(struct nand_chip *nand, u8 *buf, int len)
>  	int ret = 0;
>  	u32 cmd;
>  
> +	if (len > NFC_CMD_RAW_LEN)
> +		return -EINVAL;
> +
>  	ret = meson_nfc_dma_buffer_setup(nand, buf, len, NULL,
>  					 0, DMA_TO_DEVICE);
>  	if (ret)
> @@ -1269,6 +1275,7 @@ static int meson_nand_attach_chip(struct nand_chip *nand)
>  	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
>  	struct mtd_info *mtd = nand_to_mtd(nand);
>  	int nsectors = mtd->writesize / 1024;
> +	int raw_writesize;
>  	int ret;
>  
>  	if (!mtd->name) {
> @@ -1280,6 +1287,13 @@ static int meson_nand_attach_chip(struct nand_chip *nand)
>  			return -ENOMEM;
>  	}
>  
> +	raw_writesize = mtd->writesize + mtd->oobsize;
> +	if (raw_writesize > NFC_CMD_RAW_LEN) {
> +		dev_err(nfc->dev, "too big write size in raw mode: %d > %ld\n",
> +			raw_writesize, NFC_CMD_RAW_LEN);
> +		return -EINVAL;
> +	}
> +
>  	if (nand->bbt_options & NAND_BBT_USE_FLASH)
>  		nand->bbt_options |= NAND_BBT_NO_OOB;
>  


Thanks,
Miquèl