[PATCH] Infinite loop/always true check possible with unsigned counter.

[Andreas Schwab]

Paul Mackerras <paulus at samba.org> writes:

> Andreas Schwab writes:
>> Paul Mackerras <paulus at samba.org> writes:
>> 
>> > Manish Ahuja writes:
>> >
>> >> Repost to fix my email id.
>> >> 
>> >> 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.
>> 
>> ??? There is no rgn->cnt involved in the comparison.
>
> Look further down in lmb_add_region; there is a second for loop that
> does
>
> 	for (i = rgn->cnt-1; i >= 0; i--)

Which is exactly the one quoted above.  I still don't see your point.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab at suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
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