LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
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


  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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4be5c5fa-c3fd-8c86-e904-8e2e60173380@lwfinger.net \
    --to=larry.finger@lwfinger.net \
    --cc=aakashhemadri123@gmail.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-staging@lists.linux.dev \
    --cc=phil@philpotter.co.uk \
    --subject='Re: [PATCH v2 2/5] staging: r8188eu: cast to restricted __be32' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).