Messages in this thread | | | Date | Tue, 25 May 2021 14:46:54 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH v2 1/2] lib/math/rational.c: Fix divide by zero |
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On Tue, 25 May 2021 07:42:49 -0700 Trent Piepho <tpiepho@gmail.com> wrote:
> If the input is out of the range of the allowed values, either larger > than the largest value or closer to zero than the smallest non-zero > allowed value, then a division by zero would occur. > > In the case of input too large, the division by zero will occur on the > first iteration. The best result (largest allowed value) will be found > by always choosing the semi-convergent and excluding the denominator > based limit when finding it. > > In the case of the input too small, the division by zero will occur on > the second iteration. The numerator based semi-convergent should not be > calculated to avoid the division by zero. But the semi-convergent vs > previous convergent test is still needed, which effectively chooses > between 0 (the previous convergent) vs the smallest allowed fraction > (best semi-convergent) as the result.
Is there any known userspace workload which can trigger this?
IOW, should it be backported into -stable and fast-tracked into 5.13 or will a 5.14 merge suffice?
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