Re: [PATCH 2/4] staging: r8188eu: add error handling of rtw_read16

[Dan Carpenter <dan.carpenter@xxxxxxxxxx>]

On Thu, May 19, 2022 at 01:11:56AM +0300, Pavel Skripkin wrote:
> diff --git a/drivers/staging/r8188eu/hal/rtl8188e_hal_init.c b/drivers/staging/r8188eu/hal/rtl8188e_hal_init.c
> index e67ecbd1ba79..22661c66cc18 100644
> --- a/drivers/staging/r8188eu/hal/rtl8188e_hal_init.c
> +++ b/drivers/staging/r8188eu/hal/rtl8188e_hal_init.c
> @@ -249,11 +249,14 @@ static void efuse_read_phymap_from_txpktbuf(
>  		hi32 = cpu_to_le32(rtw_read32(adapter, REG_PKTBUF_DBG_DATA_H));
>  
>  		if (i == 0) {
> +			int res;
> +			u16 reg;
>  			/* Although lenc is only used in a debug statement,

Blank line after declarations.

I think it's better to put "int res" declarations at the start of the
function.  That's where people will expect to see it.

>  			 * do not remove it as the rtw_read16() call consumes
>  			 * 2 bytes from the EEPROM source.
>  			 */
> -			rtw_read16(adapter, REG_PKTBUF_DBG_DATA_L);
> +			res = rtw_read16(adapter, REG_PKTBUF_DBG_DATA_L, &reg);
> +			(void) res;
>  
>  			len = le32_to_cpu(lo32) & 0x0000ffff;
>  

[ snip ]

> diff --git a/drivers/staging/r8188eu/include/rtw_io.h b/drivers/staging/r8188eu/include/rtw_io.h
> index 1198d3850a6d..ce3369e33d66 100644
> --- a/drivers/staging/r8188eu/include/rtw_io.h
> +++ b/drivers/staging/r8188eu/include/rtw_io.h
> @@ -221,7 +221,7 @@ void _rtw_attrib_read(struct adapter *adapter, u32 addr, u32 cnt, u8 *pmem);
>  void _rtw_attrib_write(struct adapter *adapter, u32 addr, u32 cnt, u8 *pmem);
>  
>  int __must_check rtw_read8(struct adapter *adapter, u32 addr, u8 *data);
> -u16 rtw_read16(struct adapter *adapter, u32 addr);
> +int __must_check rtw_read16(struct adapter *adapter, u32 addr, u16 *data);
>  u32 rtw_read32(struct adapter *adapter, u32 addr);
>  void _rtw_read_mem(struct adapter *adapter, u32 addr, u32 cnt, u8 *pmem);
>  u32 rtw_read_port(struct adapter *adapter, u8 *pmem);
> diff --git a/drivers/staging/r8188eu/os_dep/ioctl_linux.c b/drivers/staging/r8188eu/os_dep/ioctl_linux.c
> index 66aac2cbe3a9..1b35951a53cb 100644
> --- a/drivers/staging/r8188eu/os_dep/ioctl_linux.c
> +++ b/drivers/staging/r8188eu/os_dep/ioctl_linux.c
> @@ -1919,7 +1919,10 @@ static int rtw_wx_read32(struct net_device *dev,
>  		sprintf(extra, "0x%02X", data32 & 0xff);
>  		break;
>  	case 2:
> -		data32 = rtw_read16(padapter, addr);
> +		ret = rtw_read16(padapter, addr, (u16 *) &data32);

Checkpatch.

I have an unpublished Smatch warning for casts like this.  You can't
pass a data32 pointer to something which is takes a u16 pointer and
expect it to work.  The last two bytes are uninitialized.

And even if you zero out the bytes, it is a bug on big endian systems.

> +		if (ret)
> +			goto err_free_ptmp;
> +
>  		sprintf(extra, "0x%04X", data32);
>  		break;
>  	case 4:

regards,
dan carpenter