Re: Linux 5.3-rc8

[Matthew Garrett]

On 16 September 2019 18:05:57 GMT-07:00, Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>On Mon, Sep 16, 2019 at 4:29 PM Ahmed S. Darwish <darwish.07@xxxxxxxxx>
>wrote:
>>
>> Linus, in all honesty, the other case is _not_ a hypothetical .
>
>Oh yes it is.
>
>You're confusing "use" with "breakage".
>
>The _use_ of getrandom(0) for key generation isn't hypothetical.
>
>But the _breakage_ from the suggested patch that makes it time out is.
>
>See the difference?
>
>The thing is, to break, you have to
>
> (a) do that key generation at boot time
>
> (b) do it on an idle machine that doesn't have entropy

Exactly the scenario where you want getrandom() to block, yes. 

>in order to basically reproduce the current boot-time hang situation
>with the broken gdm, except with an actual "generate key".
>
>Then you have to ignore the big warning too.

The big warning that's only printed in dmesg? 


-- 
Matthew Garrett | mjg59@xxxxxxxxxxxxx