Re: [PATCH -v2] notifier: Return an error when a callback has already been registered

[Sebastian Andrzej Siewior]

On 2021-12-23 16:31:01 [+0100], Borislav Petkov wrote:
> From: Borislav Petkov <bp@xxxxxxx>
> 
> Return -EEXIST when a notifier callback has already been registered on a
> notifier chain.
> 
> This should avoid any homegrown registration tracking at the callsite
> like
> 
>   https://lore.kernel.org/amd-gfx/20210512013058.6827-1-mukul.joshi@xxxxxxx
> 
> for example.
> 
> This version is an alternative of
> 
>   https://lore.kernel.org/r/20211108101157.15189-1-bp@xxxxxxxxx
> 
> which needed to touch every caller not checking the registration
> routine's return value.
> 
> Signed-off-by: Borislav Petkov <bp@xxxxxxx>

Reviewed-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>

Sebastian