Check vmlinux.h header up-to-dateness

Check that vmlinux.h headers in the repository are up-to-date with
respect to the checked in config. Doing so should make it clear to pull
request submitters that they should update headers after update of the
config (or targeted kernel version or similar).

We don't want to completely automate away the update, to have a human in
the loop to double check sanity, e.g., for cases where config values get
renamed.

Signed-off-by: Daniel Müller <deso@posteo.net>

Author: d-e-s-o

.github/workflows/test.yml

@@ -73,3 +73,31 @@ jobs:
           EOF
           cargo update
           cargo check --tests
+  generate-headers:
+    name: Generate vmlinux.h headers
+    uses: ./.github/workflows/vmlinux.h.yml
+  check-headers:
+    name: Check headers are up to date
+    runs-on: ubuntu-latest
+    needs: generate-headers
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Download generated headers
+        uses: actions/download-artifact@v4
+        with:
+          name: vmlinux.h
+          path: generated-headers
+
+      - name: Copy headers to include/ directory
+        shell: bash
+        run: |
+          # Copy each vmlinux.h file to the corresponding include/ subdirectory
+          for dir in generated-headers/*/; do
+            arch=$(basename "$dir")
+            cp "$dir"vmlinux.h "include/$arch/"
+          done
+
+      - name: Check for differences
+        run: git diff --exit-code ||
+             (echo "!!!! CHECKED IN vmlinux.h HEADER IS OUTDATED !!!!" && false)

.github/workflows/vmlinux.h.yml

@@ -6,6 +6,7 @@ on:
     branches:
       - main
   workflow_dispatch:
+  workflow_call:
 
 jobs:
   gen-headers:
@@ -87,8 +88,13 @@ jobs:
           for dir in vmlinux.h-*/; do
             arch="${dir#vmlinux.h-}"
             arch="${arch%/}"
-            mkdir -p "vmlinux.h/$arch"
-            mv "$dir"* "vmlinux.h/$arch/"
+            # Map architecture names to match include/ directory structure
+            target_arch="$arch"
+            case "$arch" in
+              ppc64le) target_arch="powerpc" ;;
+            esac
+            mkdir -p "vmlinux.h/$target_arch"
+            mv "$dir"* "vmlinux.h/$target_arch/"
           done
 
       - name: Upload combined headers