[PATCH] riscv: Enable Undefined Behavior Sanitizer UBSAN

[Jisheng Zhang <jszhang3@mail.ustc.edu.cn>]

From: Jisheng Zhang <jszhang@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@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
-- 
2.32.0