[RFC] enable UBSAN for automation tests

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

Hi all,

I would like to propose to enable the UBSAN config option in our Gitlab
pipelines. The attached patch (just for testing, do not commit) enables
UBSAN on the Xen build jobs used for most of the ARM and x86 tests. The
pipeline passes.

https://gitlab.com/xen-project/people/sstabellini/xen/-/pipelines/1656001157

Cheers,

Stefano

diff --git a/automation/gitlab-ci/build.yaml b/automation/gitlab-ci/build.yaml
index bc4a8a5ad2..92790648aa 100644
--- a/automation/gitlab-ci/build.yaml
+++ b/automation/gitlab-ci/build.yaml
@@ -333,6 +333,8 @@ alpine-3.18-gcc-debug:
       CONFIG_EXPERT=y
       CONFIG_UNSUPPORTED=y
       CONFIG_ARGO=y
+      CONFIG_UBSAN=y
+      CONFIG_UBSAN_FATAL=y
 
 debian-12-x86_64-gcc-debug:
   extends: .gcc-x86-64-build-debug
@@ -419,6 +421,11 @@ alpine-3.18-gcc-debug-arm64:
   extends: .gcc-arm64-build-debug
   variables:
     CONTAINER: alpine:3.18-arm64v8
+    EXTRA_XEN_CONFIG: |
+      CONFIG_EXPERT=y
+      CONFIG_UNSUPPORTED=y
+      CONFIG_UBSAN=y
+      CONFIG_UBSAN_FATAL=y
 
 alpine-3.18-gcc-arm64-randconfig:
   extends: .gcc-arm64-build