[PATCH] riscv: Enable Undefined Behavior Sanitizer UBSAN

[Palmer Dabbelt]

On Wed, 04 Aug 2021 09:30:59 PDT (-0700), jszhang3 at mail.ustc.edu.cn wrote:
> From: Jisheng Zhang <jszhang at kernel.org>
>
> Select ARCH_HAS_UBSAN_SANITIZE_ALL in order to allow the user to
> enable CONFIG_UBSAN_SANITIZE_ALL and instrument the entire kernel for
> ubsan checks.
>
> VDSO is excluded because its build doesn't include the
> __ubsan_handle_*() functions from lib/ubsan.c, and the VDSO has no
> sane way to report errors even if it has definitions of these functions.
>
> Passed lib/test_ubsan.c test.
>
> Signed-off-by: Jisheng Zhang <jszhang at kernel.org>
> ---
>  arch/riscv/Kconfig              | 1 +
>  arch/riscv/kernel/vdso/Makefile | 1 +
>  2 files changed, 2 insertions(+)
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index f133ac72572f..cccb95bf8331 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -28,6 +28,7 @@ config RISCV
>  	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
>  	select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
>  	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
> +	select ARCH_HAS_UBSAN_SANITIZE_ALL
>  	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
>  	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
>  	select ARCH_STACKWALK
> diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile
> index 24d936c147cd..30a5335bd317 100644
> --- a/arch/riscv/kernel/vdso/Makefile
> +++ b/arch/riscv/kernel/vdso/Makefile
> @@ -36,6 +36,7 @@ CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os
>  GCOV_PROFILE := n
>  KCOV_INSTRUMENT := n
>  KASAN_SANITIZE := n
> +UBSAN_SANITIZE := n
>
>  # Force dependency
>  $(obj)/vdso.o: $(obj)/vdso.so

Thanks, this is on for-next.