Re: [PATCH 8/8] mtd: rawnand: qcom: Fix address parsing within ->exec_op()

From: Manivannan Sadhasivam <mani@kernel.org>
To: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Md Sadre Alam <quic_mdalam@quicinc.com>,
	Sricharan Ramabadhran <quic_srichara@quicinc.com>,
	Richard Weinberger <richard@nod.at>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	Tudor Ambarus <tudor.ambarus@linaro.org>,
	Pratyush Yadav <pratyush@kernel.org>,
	Michael Walle <michael@walle.cc>,
	linux-mtd@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org,
	kernel test robot <lkp@intel.com>
Subject: Re: [PATCH 8/8] mtd: rawnand: qcom: Fix address parsing within ->exec_op()
Date: Mon, 17 Jul 2023 12:08:43 +0530	[thread overview]
Message-ID: <20230717063843.GA7062@thinkpad> (raw)
In-Reply-To: <20230716144612.32132-9-miquel.raynal@bootlin.com>

On Sun, Jul 16, 2023 at 04:46:12PM +0200, Miquel Raynal wrote:
> The naddrs variable is initialized but not used. Fixing this could have
> been a matter of dropping the variable, but the right way to do it looks
> a bit more complex: we can avoid useless writes to the q_op structure by
> using it. In practice we could even have possible out-of-bound bugs with
> the existing implementation. Let's fix all that by just performing the
> right number of assignments in the addr{1,2}_reg fields.
> 
> Fixes: 89550beb098e ("mtd: rawnand: qcom: Implement exec_op()")
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202307131959.PdPSC86K-lkp@intel.com/
> Closes: https://lore.kernel.org/oe-kbuild-all/202307131730.NOYbcjBr-lkp@intel.com/
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

LGTM! But I'm relying on Sadre to test it.

Acked-by: Manivannan Sadhasivam <mani@kernel.org>

- Mani

> ---
>  drivers/mtd/nand/raw/qcom_nandc.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
> index 4fc8dafa8f03..dc8ca60fc2e2 100644
> --- a/drivers/mtd/nand/raw/qcom_nandc.c
> +++ b/drivers/mtd/nand/raw/qcom_nandc.c
> @@ -2616,12 +2616,13 @@ static void qcom_parse_instructions(struct nand_chip *chip,
>  			offset = nand_subop_get_addr_start_off(subop, op_id);
>  			naddrs = nand_subop_get_num_addr_cyc(subop, op_id);
>  			addrs = &instr->ctx.addr.addrs[offset];
> -			for (i = 0; i < MAX_ADDRESS_CYCLE; i++) {
> -				if (i < 4)
> -					q_op->addr1_reg |= (u32)addrs[i] << i * 8;
> -				else
> -					q_op->addr2_reg |= addrs[i];
> -			}
> +
> +			for (i = 0; i < min_t(unsigned int, 4, naddrs); i++)
> +				q_op->addr1_reg |= addrs[i] << (i * 8);
> +
> +			if (naddrs > 4)
> +				q_op->addr2_reg |= addrs[4];
> +
>  			q_op->rdy_delay_ns = instr->delay_ns;
>  			break;
>  
> -- 
> 2.34.1
> 

-- 
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