On 6/30/25 3:15 AM, Alan Maguire wrote:
Sometimes changes can be introduced that modify the set of functions
encoded in BTF, or change aspects of that encoding. Add a non-fatal
comparison job to compare between the change and the base branch,
by default the "next" branch.
Signed-off-by: Alan Maguire <alan.maguire@xxxxxxxxxx>
---
.github/scripts/compare-functions.sh | 30 ++++++++++++++++++++++++++++
.github/workflows/vmtest.yml | 4 ++++
2 files changed, 34 insertions(+)
create mode 100755 .github/scripts/compare-functions.sh
Hi Alan. That's a good addition. See a couple of comments below.
diff --git a/.github/scripts/compare-functions.sh b/.github/scripts/compare-functions.sh
new file mode 100755
index 0000000..062f15c
--- /dev/null
+++ b/.github/scripts/compare-functions.sh
@@ -0,0 +1,30 @@
+#!/usr/bin/bash
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Copyright (c) 2025, Oracle and/or its affiliates.
+#
+
+GITHUB_WORKSPACE=${GITHUB_WORKSPACE:-$(pwd)}
+REPO_TARGET=${GITHUB_WORKSPACE}/.kernel
+VMLINUX=${GITHUB_WORKSPACE}/.kernel/vmlinux
+SELFTESTS=${GITHUB_WORKSPACE}/tests
nit: SELFTESTS isn't used
+export PATH=${GITHUB_WORKSPACE}/install/usr/local/bin:${PATH}
+which pahole
+pahole --version
+cd $REPO_TARGET
+pfunct --all --format_path=btf $VMLINUX > functions_latest
+# now use baseline pahole for comparison
+export PAHOLE=/usr/local/bin/pahole
So we assume that the baseline is installed at this path?
And that would be an installation done by
libbpf/ci/setup-build-env action?
I would not rely on that behavior. I think a better approach is to
build and use master (or whatever is the baseline) explicitly.
+rm -f vmlinux vmlinux.o
+export PATH=/usr/local/bin:${PATH}
+make oldconfig
+make -j $((4*$(nproc))) all
+pfunct --all --format_path=btf $VMLINUX > functions_base
+echo "Comparing vmlinux BTF functions generated with this change vs baseline."
+echo "Differences are non-fatal to the workflow, but should be examined for correctness."
You might find it useful to dump a formatted diff to
$GITHUB_STEP_SUMMARY, to get a rendered output in github UI.
See here:
https://docs.github.com/en/actions/reference/workflow-commands-for-github-actions?versionId=free-pro-team%40latest&productId=actions#adding-a-job-summary
+set +e
+diff functions_base functions_latest
+if [[ $? -eq 0 ]]; then
+ echo "Function lists are identical."
+fi
+set -e
diff --git a/.github/workflows/vmtest.yml b/.github/workflows/vmtest.yml
index 0f66eed..54bb92e 100644
--- a/.github/workflows/vmtest.yml
+++ b/.github/workflows/vmtest.yml
@@ -60,3 +60,7 @@ jobs:
shell: bash
run: .github/scripts/run-selftests.sh
+ - name: Compare functions generated
+ shell: bash
+ run: .github/scripts/compare-functions.sh
+
