Re: [PATCH v5] init: Disable defaults if init= fails

Andy Lutomirski
2014-10-15T05:57:05Z

On Tue, Oct 14, 2014 at 10:46 PM, Frank Rowand <frowand.list@gmail.com> wrote:
> On 10/14/2014 2:21 PM, Andy Lutomirski wrote:
>> On Tue, Oct 14, 2014 at 2:00 PM, Andrew Morton
>> <akpm@linux-foundation.org> wrote:
>>> On Wed, 1 Oct 2014 11:13:14 -0700 Andy Lutomirski <luto@amacapital.net> wrote:
>>>
>>>> On Wed, Oct 1, 2014 at 11:05 AM, <josh@joshtriplett.org> wrote:
>>>>> On Tue, Sep 30, 2014 at 09:53:56PM -0700, Andy Lutomirski wrote:
>>>>>> I significantly prefer default N. Scripts that play with init= really
>>>>>> don't want the fallback, and I can imagine contexts in which it could
>>>>>> be a security problem.
>>>>>
>>>>> While I certainly would prefer the non-fallback behavior for init as
>>>>> well, standard kernel practice has typically been to use "default y" for
>>>>> previously built-in features that become configurable. And I'd
>>>>> certainly prefer a compile-time configuration option like this (even
>>>>> with default y) over a "strictinit" kernel command-line option.
>>>>>
>>>>
>>>> Fair enough.
>>>>
>>>> So: "default y" for a release or two, then switch the default? Having
>>>> default y will annoy virtme, though it's not the end of the world.
>>>> Virtme is intended to work with more-or-less-normal kernels.
>>>>
>>>
>>> Adding another Kconfig option is tiresome. What was wrong with strictinit=?
>>
>> The consensus seems to be that adding a non-default option to get
>
> ^^^^^^^^^ I do not think you know what the word consensus means. :-)
>
> I did not agree.
>
> I do agree with Andrew (but with no opinion on whether "strictinit=SOMETHING"
> or just "strictinit".
>
>> sensible behavior would be unfortunate. Also, I don't like

Even you're not disagreeing that it's ugly, though, FWIW.

> ^^^^^^^^^^^^^^^^^
> behavior that is useful in some or many contexts

Is there a context in which the current behavior is useful beyond
"whoops, I typoed my grub command line edit, and I still want my
system to boot into *something* even if it's the wrong thing"? I'm
not personally that sympathetic to that particular use case, but maybe
there's another one.

--Andy

>
>> strictinit=, since backwards-compatible setups will have to do
>> init=foo strictinit=foo. My original proposal was init=foo
>> strictinit.
>>
>> TBH, my preference would be to make strict mode unconditional.
>> http://xkcd.com/1172/
>>
>> --Andy
>>
>

--
Andy Lutomirski
AMA Capital Management, LLC