Re: [PATCH 01/16] CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS: set if CPUMASK_OFFSTACK.

From: Rusty Russell
Date: Mon Mar 02 2015 - 18:44:34 EST


Paul Bolle <pebolle@xxxxxxxxxx> writes:
> On Mon, 2015-03-02 at 22:05 +1030, Rusty Russell wrote:
>> Using these functions with offstack cpus is unsafe. They use all NR_CPUS
>> bits, unstead of nr_cpumask_bits.
>>
>> In particular, lustre (in staging) used cpus_ and that caused a bug.
>>
>> Reported-by: Oleg Drokin <green@xxxxxxxxxxxxxx>
>> Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
>> ---
>> lib/Kconfig | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/lib/Kconfig b/lib/Kconfig
>> index 87da53bb1fef..722427805220 100644
>> --- a/lib/Kconfig
>> +++ b/lib/Kconfig
>> @@ -398,8 +398,8 @@ config CPUMASK_OFFSTACK
>> stack overflow.
>>
>> config DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
>> - bool "Disable obsolete cpumask functions" if DEBUG_PER_CPU_MAPS
>> - depends on BROKEN
>> + bool
>> + depends on CPUMASK_OFFSTACK
>
> This removes the "prompt" from this symbol's entry. And nothing selects
> it either (not in next-20150302 nor in this series). So I think this
> just disables this Kconfig symbol entirely. Ie, it can't be set even if
> CPUMAK_OFFSTACK is set.
>
> Should this entry perhaps be using
> def_bool y
>
> instead?

You're right. In practice, I used a different patch to actually force
enable it.

The final patch deletes it altogether, so I will just squash the two
and this will never appear in the final series.

Thanks!
Rusty.
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