Re: [PATCH 1/1] Fix kill(-1,s) returning 0 on 0 kills

[Oleg Nesterov]

On 11/23, Petr Skocik wrote:
>
> On 11/23/22 11:30, Oleg Nesterov wrote:
> >
> >But I fail to understand the /*either all 0 or all -EINVAL*/ comment above..
> >
> >Oleg.
> >
> 
> Thanks. The comment is explained in my reply to Kees Cook:
> https://lkml.org/lkml/2022/11/22/1327.
> I felt like making it because without it to me it suspiciously looks like
> the
> `if ( err != -EPERM) ret = err;` (or `if ( err != -EPERM) retval = err;` in
> the original) could be masking
> a non-EPERM failure with a later success, but it isn't because in this
> context, all the non-EPERM return vals should either ALL be 0 or ALL be
> -EINVAL.

Ah, now I see what did you mean, thanks.

Well, you are probably right, __send_signal_locked() won't fail even if
__sigqueue_alloc() fails, because si_code = SI_USER.

Not sure we should rely on this, but I won't argue.

Oleg.