Re: [Qemu-arm] [Qemu-devel] [PATCH for 2.10 21/35] arm/sysbus-fdt: fix null pointer dereference

[Philippe Mathieu-Daudé]

Hi Eric,

On 07/24/2017 06:57 PM, Eric Blake wrote:
> On 07/24/2017 04:52 PM, Eric Blake wrote:
>> On 07/24/2017 04:48 PM, Philippe Mathieu-Daudé wrote:
>>> On 07/24/2017 06:09 PM, Peter Maydell wrote:
>>>> On 24 July 2017 at 19:27, Philippe Mathieu-Daudé <address@hidden> wrote:
>>>>> Use error_report() + exit() instead of error_setg(&error_fatal).
>>>>>
>>>>> hw/arm/sysbus-fdt.c:322:9: warning: Array access (from variable
>>>>> 'node_path') results in a null pointer dereference
>>>>>      if (node_path[1]) {
>>>>>          ^~~~~~~~~~~~
>>>>
>>>> I don't understand what this warning is trying to say.
>>>> We can't get to this point with a NULL node_path,
>>>> because of the previous conditional, which is using
>>>> error_setg(&error_fatal).
>>>
>>> Ok I see, Clang is unaware than error_setg(&error_fatal) is a noreturn.
>>
>> Indeed, and that's because error_setg(&error_fatal) is not in preferred
>> form.
>>
>>>
>>> Patch dropped.
>>
>> That's a shame.  Rather, we should patch this file (and others) to avoid
>> all the inconsistent uses of error_setg(&error_*), to comply with the
>> error.h documentation.

I started to port/clean this up.
To avoid future inconsistencies, do you think we should/can enforce this
check in checkpatch (which is stricter than human review)?
Is the "Qemu error function tests" section a good place to put this check?

> 
> In other words, switching to the preferred spelling in the following files:
> device_tree.c
> hw/arm/sysbus-fdt.c
> hw/block/fdc.c
> hw/ppc/spapr_drc.c
> 
> is desirable, and has the added benefit of also silencing a Coverity
> false positive.  But it should be done in terms of switching to the
> preferred spelling, as it touches more instances than just the one that
> shuts up Coverity.
>