From: David Laight <David.Laight@ACULAB.COM>
To: 'Aakash Hemadri' <aakashhemadri123@gmail.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>,
Bjorn Helgaas <bjorn@helgaas.com>,
"linux-staging@lists.linux.dev" <linux-staging@lists.linux.dev>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH 2/2] staging: rtl8723bs: fix cast to restricted __le32
Date: Thu, 19 Aug 2021 09:43:37 +0000 [thread overview]
Message-ID: <eb38f6e0ae60489ca396de32d64f0513@AcuMS.aculab.com> (raw)
In-Reply-To: <1be80f0196bed681bf55bfe3155f564b4ebf3b76.1629135143.git.aakashhemadri123@gmail.com>
From: Aakash Hemadri
> Sent: 16 August 2021 18:35
>
> Fix sparse warning:
> warning: cast to restricted __le32
How many different copies of this crappy copy are there?
>
...
> diff --git a/drivers/staging/rtl8723bs/core/rtw_security.c
> b/drivers/staging/rtl8723bs/core/rtw_security.c
> index 381deeea99d0..5320b1a46dfb 100644
> --- a/drivers/staging/rtl8723bs/core/rtw_security.c
> +++ b/drivers/staging/rtl8723bs/core/rtw_security.c
> @@ -122,7 +122,7 @@ void rtw_wep_decrypt(struct adapter *padapter, u8 *precvframe)
> arc4_crypt(ctx, payload, payload, length);
>
> /* calculate icv and compare the icv */
> - *((u32 *)crc) = le32_to_cpu(~crc32_le(~0, payload, length - 4));
> + *((u32 *)crc) = ~crc32_le(~0, payload, length - 4);
You've removed a byteswap which is needed on BE architectures.
> }
> }
> @@ -621,7 +621,7 @@ u32 rtw_tkip_decrypt(struct adapter *padapter, u8 *precvframe)
> arc4_setkey(ctx, rc4key, 16);
> arc4_crypt(ctx, payload, payload, length);
>
> - *((u32 *)crc) = le32_to_cpu(~crc32_le(~0, payload, length - 4));
> + *((u32 *)crc) = ~crc32_le(~0, payload, length - 4);
>
> if (crc[3] != payload[length - 1] || crc[2] != payload[length - 2] ||
> crc[1] != payload[length - 3] || crc[0] != payload[length - 4])
As above - crc32_le() does a 'little-endian crc' but returns a host-ordered value.
The (horrid) array cast means you need to store a LE value.
There are a dozen better ways to do this - I'm bored of quoting them.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2021-08-19 9:43 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-16 17:35 [PATCH 0/2] staging: rtl8732bs: Fix sparse warnings Aakash Hemadri
2021-08-16 17:35 ` [PATCH 1/2] staging: rtl8732bs: incorrect type in assignment Aakash Hemadri
2021-08-16 22:43 ` kernel test robot
2021-08-16 17:35 ` [PATCH 2/2] staging: rtl8723bs: fix cast to restricted __le32 Aakash Hemadri
2021-08-19 9:43 ` David Laight [this message]
2021-08-16 18:48 ` [PATCH 0/2] staging: rtl8732bs: Fix sparse warnings Fabio M. De Francesco
2021-08-18 5:58 ` Fabio M. De Francesco
-- strict thread matches above, loose matches on Subject: below --
2021-08-16 17:30 Aakash Hemadri
2021-08-16 17:30 ` [PATCH 2/2] staging: rtl8723bs: fix cast to restricted __le32 Aakash Hemadri
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