linux-kernel - Re: [PATCH] include/linux/skbuff.h: using '0xffff' instead of '~0U'

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1369927806.2414.2.camel@bwh-desktop.uk.level5networks.com>
Date:	Thu, 30 May 2013 16:30:06 +0100
From:	Ben Hutchings <bhutchings@...arflare.com>
To:	Chen Gang <gang.chen@...anux.com>
CC:	<edumazet@...gle.com>, Pravin Shelar <pshelar@...ira.com>,
	<mgorman@...e.de>, David Miller <davem@...emloft.net>,
	Andrew Morton <akpm@...ux-foundation.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	netdev <netdev@...r.kernel.org>
Subject: Re: [PATCH] include/linux/skbuff.h: using '0xffff' instead of '~0U'

On Thu, 2013-05-30 at 14:03 +0800, Chen Gang wrote:
> Both 'transport_header' and 'mac_header' are u16, which are never equal
> to '~0U'.
> 
> So need use '0xffff' instead of '~0U'.

...and give this magic number a name?

Ben.

> The related warning (with EXTRA_CFLAGS=-W ARCH=m68k for allmodconfig)
>   include/linux/skbuff.h:1587:2: warning: comparison is always true due to limited range of data type [-Wtype-limits]
>   ...
> 
> 
> Signed-off-by: Chen Gang <gang.chen@...anux.com>
> ---
>  include/linux/skbuff.h |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
> index 2e0ced1..03ba058 100644
> --- a/include/linux/skbuff.h
> +++ b/include/linux/skbuff.h
> @@ -1581,7 +1581,7 @@ static inline void skb_set_inner_mac_header(struct sk_buff *skb,
>  }
>  static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
>  {
> -	return skb->transport_header != ~0U;
> +	return skb->transport_header != 0xffff;
>  }
>  
>  static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
> @@ -1624,7 +1624,7 @@ static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
>  
>  static inline int skb_mac_header_was_set(const struct sk_buff *skb)
>  {
> -	return skb->mac_header != ~0U;
> +	return skb->mac_header != 0xffff;
>  }
>  
>  static inline void skb_reset_mac_header(struct sk_buff *skb)

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/