Date: Wed, 1 Aug 2007 11:17:15 -0400
From: Joe Korty <joe.korty@ccur.com>
To: Paul Mackerras <paulus@samba.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
       Al Viro <viro@ftp.linux.org.uk>, Alexey Dobriyan <adobriyan@sw.ru>,
       akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
       herbert@gondor.apana.org.au
Subject: Re: WARN_ON() which sometimes sucks
Message-ID: <20070801151715.GA22431@tsunami.ccur.com>
Reply-To: Joe Korty <joe.korty@ccur.com>
References: <20070731155527.GB7253@localhost.sw.ru> <20070731160248.GK21089@ftp.linux.org.uk> <18096.949.934194.648312@cargo.ozlabs.ibm.com> <alpine.LFD.0.999.0707312101410.3582@woody.linux-foundation.org> <18096.2592.877510.221163@cargo.ozlabs.ibm.com>
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On Wed, Aug 01, 2007 at 02:20:48PM +1000, Paul Mackerras wrote:
> Linus Torvalds writes:
> 
> > Umm. The WARN_ON() might actually get a "long long" value for all we know. 
> > Ie it's perfectly possible that the WARN_ON might look like
> > 
> > 	/* Must not have high bits on */
> > 	WARN_ON(offset & 0xffffffff00000000);
> > 
> > which on a 32-bit pcc would apparently do the wrong thing entirely as it 
> > stands now. No?
> 
> Actually, because of the typeof in the powerpc WARN_ON, I think it
> would fail to build since we'd be passing a long long value to an
> inline asm, or at least I hope it would fail to build. :)


Turning the condition into an integer should work ...

	#define NEW_WARN_ON(x) OLD_WARN_ON(!!(x))

Regards,
Joe

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