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From: David Miller <davem@davemloft.net>
To: ebiederm@xmission.com
Cc: kirill@shutemov.name, netdev@vger.kernel.org,
	pablo@netfilter.org, ldv@altlinux.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] netlink: fix gcc -Wconversion compilation warning
Date: Fri, 17 Dec 2010 12:02:34 -0800 (PST)	[thread overview]
Message-ID: <20101217.120234.59681524.davem@davemloft.net> (raw)
In-Reply-To: <m1sjy1uzj6.fsf@fess.ebiederm.org>

From: ebiederm@xmission.com (Eric W. Biederman)
Date: Mon, 13 Dec 2010 13:35:25 -0800

> "Kirill A. Shutsemov" <kirill@shutemov.name> writes:
> 
>> From: Dmitry V. Levin <ldv@altlinux.org>
>>
>> $ cat << EOF | gcc -Wconversion -xc -S -o/dev/null -
>> unsigned f(void) {return NLMSG_HDRLEN;}
>> EOF
>> <stdin>: In function 'f':
>> <stdin>:3:26: warning: negative integer implicitly converted to unsigned type
>>
> This doesn't look like a bad fix, but I believe things will fail if
> we give NLMSG_ALIGN an unsigned long like size_t.  Say like sizeof.

What are you talking about? That's exactly his test case,
look at what NLMSG_HDRLEN is defined to, it's exactly the
case you're worried "will fail", it passes sizeof() to
NLMSG_ALIGN.

I think I'll apply Kirill's original patch, it's good enough
and simpler.

  parent reply	other threads:[~2010-12-17 20:02 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-12-13 17:05 [PATCH] netlink: fix gcc -Wconversion compilation warning Kirill A. Shutsemov
2010-12-13 21:35 ` Eric W. Biederman
2010-12-14 11:27   ` Kirill A. Shutemov
2010-12-17 20:02   ` David Miller [this message]
2010-12-18  6:58     ` Eric W. Biederman

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