[PATCH] arch/x86/um: Disable UBSAN sanitization

[Roberto Sassu]

From: Roberto Sassu <roberto.sassu at huawei.com>

Disable UBSAN sanitization on UML, since UML does not support it.

This fixes the error message when building the kernel:

  CALL    scripts/checksyscalls.sh
  VDSO    arch/x86/um/vdso/vdso.so.dbg
arch/x86/um/vdso/vdso.so.dbg: undefined symbols found

Signed-off-by: Roberto Sassu <roberto.sassu at huawei.com>
---
 arch/x86/um/vdso/Makefile | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/um/vdso/Makefile b/arch/x86/um/vdso/Makefile
index b86d634730b2..ca79c0de582e 100644
--- a/arch/x86/um/vdso/Makefile
+++ b/arch/x86/um/vdso/Makefile
@@ -3,8 +3,10 @@
 # Building vDSO images for x86.
 #
 
-# do not instrument on vdso because KASAN is not compatible with user mode
+# do not instrument on vdso because KASAN/UBSAN are not compatible with user
+# mode
 KASAN_SANITIZE			:= n
+UBSAN_SANITIZE			:= n
 
 # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
 KCOV_INSTRUMENT                := n
-- 
2.34.1