Re: [PATCH 1/2] ubsan: allow to disable the null sanitizer

Heiko Carstens
2016-09-13T06:46:22Z

On Mon, Sep 12, 2016 at 02:37:19PM +0200, Christian Borntraeger wrote:
> Some architectures use a hardware defined struct at address zero.
> Checking for a null pointer will result in many ubsan reports.
> Let users disable the null sanitizer.
>
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> ---
> lib/Kconfig.ubsan | 11 +++++++++++
> scripts/Makefile.ubsan | 5 ++++-
> 2 files changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan
> index 39494af..851c3f2 100644
> --- a/lib/Kconfig.ubsan
> +++ b/lib/Kconfig.ubsan
> @@ -1,6 +1,9 @@
> config ARCH_HAS_UBSAN_SANITIZE_ALL
> bool
>
> +config ARCH_WANTS_UBSAN_NO_NULL
> + def_bool n
> +
> config UBSAN
> bool "Undefined behaviour sanity checker"
> help
> @@ -34,3 +37,11 @@ config UBSAN_ALIGNMENT
> This option enables detection of unaligned memory accesses.
> Enabling this option on architectures that support unaligned
> accesses may produce a lot of false positives.
> +
> +config UBSAN_NULL
> + bool "Enable checking of null pointers"
> + depends on UBSAN
> + default y if UBSAN && !ARCH_WANTS_UBSAN_NO_NULL

I removed the not needed UBSAN from the "default y" and applied both
patches to the s390 tree.

Thanks!