Re: ERR_PTR(0) in a couple of places

[Krzysztof Kozlowski]

On 24/09/2023 02:41, Dr. David Alan Gilbert wrote:
> Hi,
>   I randomly noticed there are a couple of places in the kernel that
> do
>    ERR_PTR(0);
> 
> and thought that was odd - shouldn't those just be NULL's ?
> 
> 1) i915
>   drivers/gpu/drm/i915/gt/uc/selftest_guc_multi_lrc.c : 47
> 
>     if (i <= 1)
>       return ERR_PTR(0);
> 
>   from f9d72092cb490 
> 
> 2) trf7970a
>   drivers/nfc/trf7970a.c : 896
> 
>       trf->ignore_timeout =
>          !cancel_delayed_work(&trf->timeout_work);
>       trf->rx_skb = ERR_PTR(0);

I would guess that code is relying on rx_skb being valid pointer or ERR
(if (!IS_ERR(...))).

Best regards,
Krzysztof