Re: [PATCH 103/104] mm: remove depends on CONFIG_EXPERIMENTAL

From: Kees Cook
Date: Tue Nov 06 2012 - 09:55:37 EST


On Mon, Nov 5, 2012 at 9:57 PM, David Rientjes <rientjes@xxxxxxxxxx> wrote:
> On Mon, 5 Nov 2012, Kees Cook wrote:
>
>> >>> diff --git a/mm/Kconfig b/mm/Kconfig
>> >>> index a3f8ddd..679945e 100644
>> >>> --- a/mm/Kconfig
>> >>> +++ b/mm/Kconfig
>> >>> @@ -1,6 +1,5 @@
>> >>> config SELECT_MEMORY_MODEL
>> >>> def_bool y
>> >>> - depends on EXPERIMENTAL || ARCH_SELECT_MEMORY_MODEL
>> >>>
>> >>> choice
>> >>> prompt "Memory model"
>> >>
>> >> I thought you agreed to only drop EXPERIMENTAL here in
>> >> http://marc.info/?l=linux-kernel&m=135103415901094 and leave
>> >> ARCH_SELECT_MEMORY_MODEL, which you've orphaned with the above, for phase
>> >> two of your effort?
>> >
>> > Ah! Yes, thanks. I'll restore that.
>>
>> Wait, no. This is an "OR". ARCH_SELECT_MEMORY_MODEL has no affect on
>> SELECT_MEMORY_MODEL if EXPERIMENTAL is always considered on. My
>> proposal was to deal with ARCH_SELECT_MEMORY_MODEL separately. Did I
>> misunderstand something?
>>
>
> We're rehashing the same discussion as before? I left the earlier thread
> with the understanding that this would become
>
> depends on ARCH_SELECT_MEMORY_MODEL
>
> and then fix ARCH_SELECT_MEMORY_MODEL when people complain for
> configurations that actually allow you to configure the memory model. It
> never should have been short-circuited by EXPERIMENTAL in the first place,
> but enabling it to be configurable for everybody and orphaning
> ARCH_SELECT_MEMORY_MODEL doesn't sound appropriate. I think we should do
> some due diligence in actually making ARCH_SELECT_MEMORY_MODEL work so
> people are presented with a config that will work on their machines.
>
> (This is independent of the rest of the series, we can certainly remove
> EXPERIMENTAL regardless of this decision, I simply think we should be
> leaving ARCH_SELECT_MEMORY_MODEL to prevent users with
> CONFIG_EXPERIMENTAL=n from being presented with a new ability to change
> their memory model that actually doesn't work for them.)

Okay, that's cool. I misunderstood what you'd wanted here. I'll leave
ARCH_SELECT_MEMORY_MODEL in place.

Thanks!

-Kees

--
Kees Cook
Chrome OS Security
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/