[PATCH v6] kernel: add kcov code coverage

[Dmitry Vyukov]

On Tue, Feb 2, 2016 at 5:02 PM, Andrey Ryabinin <ryabinin.a.a at gmail.com> wrote:
> 2016-01-25 16:00 GMT+03:00 Dmitry Vyukov <dvyukov at google.com>:
>
>> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
>> index ecb9e75..cde6bd1 100644
>> --- a/lib/Kconfig.debug
>> +++ b/lib/Kconfig.debug
>> @@ -678,6 +678,26 @@ config DEBUG_STACKOVERFLOW
>>
>>           If in doubt, say "N".
>>
>> +config ARCH_HAS_KCOV
>> +       bool
>> +       help
>> +         KCOV does not have any arch-specific code, but currently it is enabled
>> +         only for x86_64. KCOV requires testing on other archs, and most likely
>> +         disabling of instrumentation for some early boot code.
>> +
>> +config KCOV
>> +       bool "Code coverage for fuzzing"
>> +       depends on ARCH_HAS_KCOV
>
> I think we should select DEBUG_FS here, since this useless without it.

Done in v7

> Also you placed this into 'Memory Debugging' submenu which seems wrong.

Any better suggestions?

>> +       help
>> +         KCOV exposes kernel code coverage information in a form suitable
>> +         for coverage-guided fuzzing (randomized testing).
>> +
>> +         If RANDOMIZE_BASE is enabled, PC values will not be stable across
>> +         different machines and across reboots. If you need stable PC values,
>> +         disable RANDOMIZE_BASE.
>> +
>> +         For more details, see Documentation/kcov.txt.
>> +
>>  source "lib/Kconfig.kmemcheck"
>>