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Date: Tue, 10 Jul 2007 02:41:21 +0200
From: Felix Domke <tmbinc@elitedvb.net>
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To: ppc-dev <linuxppc-dev@ozlabs.org>
Subject: Re: [PATCH] Infinite loop/always true check possible with unsigned
	counter.
References: <469270F3.4070206@austin.ibm.com> <46928691.2040008@austin.ibm.com>
	<18066.53384.449544.952545@cargo.ozlabs.ibm.com>
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Paul Mackerras wrote:
>> Fix to correct a possible infinite loop or an always true check when the 
>> unsigned long counter "i" is used in
>> lmb_add_region() in the following for loop:
>> for (i = rgn->cnt-1; i >= 0; i--)
> Unfortunately this won't fix the bug.  Since rgn->cnt is unsigned
> long, the comparison will be done as an unsigned comparison even if i
> is signed.
> Instead, change the loop to go from rgn->cnt down to 1, and in the
> loop body, change all instances of "i+1" to "i", and "i" to "i-1".
What's about

i = rgn->cnt;
while (i--)
...
?

(or  for (i=rgn->cnt; i--; ), if you want a for-loop)


Felix