Re: [PATCH v3 33/39] kasan, x86, s390: update undef CONFIG_KASAN

elver
2020-10-01T17:59:31Z

On Fri, Sep 25, 2020 at 12:50AM +0200, Andrey Konovalov wrote:
> With the intoduction of hardware tag-based KASAN some kernel checks of
> this kind:
>
> ifdef CONFIG_KASAN
>
> will be updated to:
>
> if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
>
> x86 and s390 use a trick to #undef CONFIG_KASAN for some of the code
> that isn't linked with KASAN runtime and shouldn't have any KASAN
> annotations.
>
> Also #undef CONFIG_KASAN_GENERIC with CONFIG_KASAN.
>
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

Reviewed-by: Marco Elver <elver@google.com>

> ---
> Change-Id: I2a622db0cb86a8feb60c30d8cb09190075be2a90
> ---
> arch/s390/boot/string.c | 1 +
> arch/x86/boot/compressed/misc.h | 1 +
> 2 files changed, 2 insertions(+)
>
> diff --git a/arch/s390/boot/string.c b/arch/s390/boot/string.c
> index b11e8108773a..faccb33b462c 100644
> --- a/arch/s390/boot/string.c
> +++ b/arch/s390/boot/string.c
> @@ -3,6 +3,7 @@
> #include <linux/kernel.h>
> #include <linux/errno.h>
> #undef CONFIG_KASAN
> +#undef CONFIG_KASAN_GENERIC
> #include "../lib/string.c"
>
> int strncmp(const char *cs, const char *ct, size_t count)
> diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
> index 726e264410ff..2ac973983a8e 100644
> --- a/arch/x86/boot/compressed/misc.h
> +++ b/arch/x86/boot/compressed/misc.h
> @@ -12,6 +12,7 @@
> #undef CONFIG_PARAVIRT_XXL
> #undef CONFIG_PARAVIRT_SPINLOCKS
> #undef CONFIG_KASAN
> +#undef CONFIG_KASAN_GENERIC
>
> /* cpu_feature_enabled() cannot be used this early */
> #define USE_EARLY_PGTABLE_L5
> --
> 2.28.0.681.g6f77f65b4e-goog
>