Re:Re:[PATCH 6/6] irq: Potentially 'offset out of size' bug

From: Jiasheng Jiang
Date: Tue Sep 14 2021 - 04:48:36 EST

> On Fri, Sep 10 2021 at 03:26, Jiasheng Jiang wrote:
> The find_next_bit() use nr_irqs as size, and using it without
> any check might cause its returned value out of the sizei

On Fri, Sep 10 2021 at 18:28, tglx wrote:
> Why exactly is this a problem? The return value has to be checked at the
> call site anyway.

There is really a check at the call site, but the annotation of the
irq_get_next_irq() is 'Returns next irq number after offset or nr_irqs
if none is found', which tells the programmer should not check the
return value of it. In case of a programmer write a new call for the
irq_get_next_irq(), he may not check the return value because of the
annotation said. Therefore, it had better to add the check inside of
irq_get_next_irq() to fit for the annotation.


Jiasheng Jiang