Re: [PATCH] powerpc/powernv/sriov: fix unsigned int win compared to less than zero

From: Michael Ellerman
Date: Mon Nov 16 2020 - 22:07:58 EST


Andrew Donnellan <ajd@xxxxxxxxxxxxx> writes:

> On 10/11/20 10:19 pm, xiakaixu1987@xxxxxxxxx wrote:
>> From: Kaixu Xia <kaixuxia@xxxxxxxxxxx>
>>
>> Fix coccicheck warning:
>>
>> ./arch/powerpc/platforms/powernv/pci-sriov.c:443:7-10: WARNING: Unsigned expression compared with zero: win < 0
>> ./arch/powerpc/platforms/powernv/pci-sriov.c:462:7-10: WARNING: Unsigned expression compared with zero: win < 0
>>
>> Reported-by: Tosk Robot <tencent_os_robot@xxxxxxxxxxx>
>> Signed-off-by: Kaixu Xia <kaixuxia@xxxxxxxxxxx>
>
> This seems like the right fix, the value assigned to win can indeed be
> -1 so it should be signed. Thanks for sending the patch.
>
> Reviewed-by: Andrew Donnellan <ajd@xxxxxxxxxxxxx>

I'll add:

Fixes: 39efc03e3ee8 ("powerpc/powernv/sriov: Move M64 BAR allocation into a helper")

Which I think is the culprit as it changed:

if (win >= phb->ioda.m64_bar_idx + 1)

to:

if (win < 0)


cheers