From: Larry Finger <Larry.Finger@lwfinger.net>
To: Aakash Hemadri <aakashhemadri123@gmail.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Phillip Potter <phil@philpotter.co.uk>
Cc: linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 2/5] staging: r8188eu: cast to restricted __be32
Date: Fri, 20 Aug 2021 16:44:49 -0500 [thread overview]
Message-ID: <4be5c5fa-c3fd-8c86-e904-8e2e60173380@lwfinger.net> (raw)
In-Reply-To: <602aefc30b0d979dc6e402d52da2f096ea5c67cf.1629360917.git.aakashhemadri123@gmail.com>
On 8/19/21 3:17 AM, Aakash Hemadri wrote:
> Fix sparse warning:
>> rtw_br_ext.c:836:54: warning: cast to restricted __be32
>
> Unnecessary double cast, remove them.
>
> Signed-off-by: Aakash Hemadri <aakashhemadri123@gmail.com>
> ---
> drivers/staging/r8188eu/core/rtw_br_ext.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/staging/r8188eu/core/rtw_br_ext.c b/drivers/staging/r8188eu/core/rtw_br_ext.c
> index 404fa8904e47..6a0462ce6230 100644
> --- a/drivers/staging/r8188eu/core/rtw_br_ext.c
> +++ b/drivers/staging/r8188eu/core/rtw_br_ext.c
> @@ -671,7 +671,7 @@ void dhcp_flag_bcast(struct adapter *priv, struct sk_buff *skb)
> (udph->dest == __constant_htons(SERVER_PORT))) { /* DHCP request */
> struct dhcpMessage *dhcph =
> (struct dhcpMessage *)((size_t)udph + sizeof(struct udphdr));
> - u32 cookie = be32_to_cpu((__be32)dhcph->cookie);
> + u32 cookie = dhcph->cookie;
>
> if (cookie == DHCP_MAGIC) { /* match magic word */
> if (!(dhcph->flags & htons(BROADCAST_FLAG))) {
>
This patch is wrong. All the documentation I could find tells me that the
multi-byte entries in dhcph are big-endian, thus the new line should read:
u32 cookie = be32_to_cpu(dhcph->cookie);
combined with:
@@ -649,7 +650,7 @@ struct dhcpMessage {
u_int8_t chaddr[16];
u_int8_t sname[64];
u_int8_t file[128];
- u_int32_t cookie;
+ __be32 cookie;
u_int8_t options[308]; /* 312 - cookie */
};
The old code was, in fact, correct, but not in a way that satisfied Sparse.
Larry
next prev parent reply other threads:[~2021-08-20 21:44 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-19 8:17 [PATCH v2 0/5] staging: r8188eu: fix sparse warnings Aakash Hemadri
2021-08-19 8:17 ` [PATCH v2 1/5] staging: r8188eu: restricted __be16 degrades to int Aakash Hemadri
2021-08-19 8:17 ` [PATCH v2 2/5] staging: r8188eu: cast to restricted __be32 Aakash Hemadri
2021-08-19 12:58 ` Fabio M. De Francesco
2021-08-19 17:19 ` Greg Kroah-Hartman
2021-08-20 11:40 ` Aakash Hemadri
2021-08-20 21:44 ` Larry Finger [this message]
2021-08-21 14:21 ` Aakash Hemadri
2021-08-22 21:30 ` David Laight
2021-08-23 8:26 ` Aakash Hemadri
2021-08-23 14:19 ` Larry Finger
2021-08-19 8:17 ` [PATCH v2 3/5] staging: r8188eu: incorrect type in csum_ipv6_magic Aakash Hemadri
2021-08-20 21:38 ` Larry Finger
2021-08-21 14:19 ` Aakash Hemadri
2021-08-20 21:48 ` Larry Finger
2021-08-19 8:17 ` [PATCH v2 4/5] staging: r8188eu: restricted __be16 degrades to int Aakash Hemadri
2021-08-19 17:20 ` Greg Kroah-Hartman
2021-08-20 15:10 ` Fabio M. De Francesco
2021-08-21 14:18 ` Aakash Hemadri
2021-08-19 8:17 ` [PATCH v2 5/5] staging: r8188eu: incorrect type in assignment Aakash Hemadri
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