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

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