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

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

Hi Arseniy,

avkrasnov@sberdevices.ru wrote on Tue, 6 Jun 2023 10:37:43 +0300:

> On 06.06.2023 10:16, Miquel Raynal wrote:
> > Hi Arseniy,
> > 
> > AVKrasnov@sberdevices.ru wrote on Mon, 5 Jun 2023 22:10:46 +0300:
> >   
> >> Meson NAND controller has limited buffer length, so check it before
> >> command execution to avoid length trim. Also check MTD write size on
> >> chip attach.  
> > 
> > Almost there :)  
> 
> Hello Miquel!
> 
> You mean to rephrase it? :)

Not at all, I meant: there is something to change in this file (see
below) but the patch is close to be ready.

> 
> Thanks, Arseniy
> 
> >   
> >>
> >> Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
> >> ---
> >>  drivers/mtd/nand/raw/meson_nand.c | 22 +++++++++++++++++++---
> >>  1 file changed, 19 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
> >> index 074e14225c06..bfb5363cac23 100644
> >> --- a/drivers/mtd/nand/raw/meson_nand.c
> >> +++ b/drivers/mtd/nand/raw/meson_nand.c
> >> @@ -108,6 +108,8 @@
> >>  
> >>  #define PER_INFO_BYTE		8
> >>  
> >> +#define NFC_CMD_RAW_LEN	GENMASK(13, 0)
> >> +
> >>  struct meson_nfc_nand_chip {
> >>  	struct list_head node;
> >>  	struct nand_chip nand;
> >> @@ -280,7 +282,7 @@ static void meson_nfc_cmd_access(struct nand_chip *nand, int raw, bool dir,
> >>  
> >>  	if (raw) {
> >>  		len = mtd->writesize + mtd->oobsize;
> >> -		cmd = (len & GENMASK(13, 0)) | scrambler | DMA_DIR(dir);
> >> +		cmd = len | scrambler | DMA_DIR(dir);
> >>  		writel(cmd, nfc->reg_base + NFC_REG_CMD);
> >>  		return;
> >>  	}
> >> @@ -544,7 +546,7 @@ static int meson_nfc_read_buf(struct nand_chip *nand, u8 *buf, int len)
> >>  	if (ret)
> >>  		goto out;
> >>  
> >> -	cmd = NFC_CMD_N2M | (len & GENMASK(13, 0));
> >> +	cmd = NFC_CMD_N2M | len;
> >>  	writel(cmd, nfc->reg_base + NFC_REG_CMD);
> >>  
> >>  	meson_nfc_drain_cmd(nfc);
> >> @@ -568,7 +570,7 @@ static int meson_nfc_write_buf(struct nand_chip *nand, u8 *buf, int len)
> >>  	if (ret)
> >>  		return ret;
> >>  
> >> -	cmd = NFC_CMD_M2N | (len & GENMASK(13, 0));
> >> +	cmd = NFC_CMD_M2N | len;
> >>  	writel(cmd, nfc->reg_base + NFC_REG_CMD);
> >>  
> >>  	meson_nfc_drain_cmd(nfc);
> >> @@ -936,6 +938,9 @@ static int meson_nfc_exec_op(struct nand_chip *nand,
> >>  			break;
> >>  
> >>  		case NAND_OP_DATA_IN_INSTR:
> >> +			if (instr->ctx.data.len > NFC_CMD_RAW_LEN)
> >> +				return -EINVAL;  
> > 
> > You need to refuse the operation earlier. That's what the check_op
> > boolean is about. Maybe you can take inspiration from anfc_check_op()
> > in the arasan controller.  
> 
> Ok! Thanks!
> 
> >   
> >> +
> >>  			buf = meson_nand_op_get_dma_safe_input_buf(instr);
> >>  			if (!buf)
> >>  				return -ENOMEM;
> >> @@ -944,6 +949,9 @@ static int meson_nfc_exec_op(struct nand_chip *nand,
> >>  			break;
> >>  
> >>  		case NAND_OP_DATA_OUT_INSTR:
> >> +			if (instr->ctx.data.len > NFC_CMD_RAW_LEN)
> >> +				return -EINVAL;  
> > 
> > Same.
> >   
> >> +
> >>  			buf = meson_nand_op_get_dma_safe_output_buf(instr);
> >>  			if (!buf)
> >>  				return -ENOMEM;
> >> @@ -1181,6 +1189,7 @@ 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) {
> >> @@ -1192,6 +1201,13 @@ 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  


Thanks,
Miquèl

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