Re: [PATCH 26/26] kasan: rework Kconfig settings

Arnd Bergmann
2017-03-03T15:03:57Z

On Fri, Mar 3, 2017 at 3:51 PM, Andrey Ryabinin <aryabinin@virtuozzo.com> wrote:
>
>
> On 03/02/2017 07:38 PM, Arnd Bergmann wrote:
>
>>
>> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
>> index 97d62c2da6c2..27c838c40a36 100644
>> --- a/lib/Kconfig.debug
>> +++ b/lib/Kconfig.debug
>> @@ -216,10 +216,9 @@ config ENABLE_MUST_CHECK
>> config FRAME_WARN
>> int "Warn for stack frames larger than (needs gcc 4.4)"
>> range 0 8192
>> - default 0 if KASAN
>> - default 2048 if GCC_PLUGIN_LATENT_ENTROPY
>> + default 3072 if KASAN_EXTRA
>> default 1024 if !64BIT
>> - default 2048 if 64BIT
>> + default 1280 if 64BIT
>
> This looks unrelated. Also, it means that now we have 1280 with KASAN=y && KASAN_EXTRA=n.
> Judging from changelog I assume that this hunk slipped here from the follow up series.

Right, this slipped in by accident, I've already fixed it up locally.

>> help
>> Tell gcc to warn at build time for stack frames larger than this.
>> Setting this too low will cause a lot of warnings.
>> @@ -499,7 +498,7 @@ config DEBUG_OBJECTS_ENABLE_DEFAULT
>>
>> config DEBUG_SLAB
>> bool "Debug slab memory allocations"
>> - depends on DEBUG_KERNEL && SLAB && !KMEMCHECK
>> + depends on DEBUG_KERNEL && SLAB && !KMEMCHECK && !KASAN
>> help
>> Say Y here to have the kernel do limited verification on memory
>> allocation as well as poisoning memory on free to catch use of freed
>> @@ -511,7 +510,7 @@ config DEBUG_SLAB_LEAK
>>
>> config SLUB_DEBUG_ON
>> bool "SLUB debugging on by default"
>> - depends on SLUB && SLUB_DEBUG && !KMEMCHECK
>> + depends on SLUB && SLUB_DEBUG && !KMEMCHECK && !KASAN
>
> Why? SLUB_DEBUG_ON works with KASAN.

Ok, will fix. I wrongly guessed that kmemcheck and kasan had the
same reason for the two dependencies here.

Arnd