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Message-ID: <5445d915-0c6c-b84f-158e-160e7645cbbd@gmail.com>
Date:   Wed, 13 Jul 2022 13:24:41 +0300
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Subject: Re: [PATCH] staging: r888eu: use dynamic allocation for efuse buffer
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To:     Martin Kaiser <martin@kaiser.cx>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Larry Finger <Larry.Finger@lwfinger.net>,
        Phillip Potter <phil@philpotter.co.uk>,
        Michael Straube <straube.linux@gmail.com>,
        linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org,
        Dan Carpenter <dan.carpenter@oracle.com>
References: <20220713075804.140986-1-martin@kaiser.cx>
From:   Pavel Skripkin <paskripkin@gmail.com>
In-Reply-To: <20220713075804.140986-1-martin@kaiser.cx>
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Hi Martin,

Martin Kaiser <martin@kaiser.cx> says:
> Use kmalloc to allocate the efuse buffer in ReadAdapterInfo8188EU and
> free it on exit. This is better than using a 512 byte array on the stack.
> 
> It's ok to drop the __aligned(4) qualifier. kmalloc aligns to
> ARCH_KMALLOC_MINALIGN, this is at least 8 bytes.
> 
> Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
> Suggested-by: Larry Finger <Larry.Finger@lwfinger.net>
> Signed-off-by: Martin Kaiser <martin@kaiser.cx>
> ---
>   drivers/staging/r8188eu/hal/usb_halinit.c | 8 ++++++--
>   1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/r8188eu/hal/usb_halinit.c b/drivers/staging/r8188eu/hal/usb_halinit.c
> index 8902dda7b8d8..421fe7c40390 100644
> --- a/drivers/staging/r8188eu/hal/usb_halinit.c
> +++ b/drivers/staging/r8188eu/hal/usb_halinit.c
> @@ -926,7 +926,7 @@ void ReadAdapterInfo8188EU(struct adapter *Adapter)
>   {
>   	struct eeprom_priv *eeprom = &Adapter->eeprompriv;
>   	struct led_priv *ledpriv = &Adapter->ledpriv;
> -	u8 efuse_buf[EFUSE_MAP_LEN_88E] __aligned(4);
> +	u8 *efuse_buf;
>   	u8 eeValue;
>   	int res;
>   
> @@ -937,7 +937,10 @@ void ReadAdapterInfo8188EU(struct adapter *Adapter)
>   
>   	eeprom->bautoload_fail_flag	= !(eeValue & EEPROM_EN);
>   
> -	memset(efuse_buf, 0xFF, sizeof(efuse_buf));
> +	efuse_buf = kmalloc(EFUSE_MAP_LEN_88E, GFP_KERNEL);
> +	if (!efuse_buf)
> +		return;

I think, it worth returning an error to caller. Functions right after 
the allocation do initialization, so leaving fields as-is seems to be 
dangerous


Thanks,
--Pavel Skripkin