Factor out tar-artifacts action

.github/workflows/kernel-build.yml

@@ -45,7 +45,6 @@ jobs:
     runs-on: ${{ fromJSON(inputs.runs_on) }}
     timeout-minutes: 100
     env:
-        ARCHIVE_MAKE_HELPERS: ${{ github.repository != 'kernel-patches/bpf' && 'true' || '' }}
         KERNEL: ${{ inputs.kernel }}
         REPO_ROOT: ${{ github.workspace }}
         REPO_PATH: ""
@@ -140,9 +139,17 @@ jobs:
           max-make-jobs: 32
           llvm-version: ${{ inputs.llvm-version }}
       - name: Tar artifacts
-        working-directory: ${{ env.REPO_ROOT }}
-        run: |
-          bash .github/scripts/tar-artifact.sh ${{ inputs.arch }} ${{ inputs.toolchain_full }}
+        id: tar-artifacts
+        uses: ./tar-artifacts
+        env:
+          ARCHIVE_BPF_SELFTESTS: 'true'
+          ARCHIVE_MAKE_HELPERS: ${{ github.repository != 'kernel-patches/bpf' && 'true' || '' }}
+          ARCHIVE_SCHED_EXT_SELFTESTS: ${{ env.BUILD_SCHED_EXT_SELFTESTS }}
+        with:
+          kbuild-output: ${{ env.KBUILD_OUTPUT }}
+          repo-root: ${{ env.REPO_ROOT }}
+          arch: ${{ inputs.arch }}
+          toolchain: ${{ inputs.toolchain }}
       - if: ${{ github.event_name != 'push' }}
         name: Remove KBUILD_OUTPUT content
         shell: bash
@@ -155,4 +162,4 @@ jobs:
         with:
           name: vmlinux-${{ inputs.arch }}-${{ inputs.toolchain_full }}${{ inputs.release && '-release' || '' }}
           if-no-files-found: error
-          path: vmlinux-${{ inputs.arch }}-${{ inputs.toolchain_full }}.tar.zst
+          path: ${{ steps.tar-artifacts.outputs.archive-name }}

tar-artifacts/action.yml

@@ -0,0 +1,28 @@
+name: 'Tar build artifacts'
+inputs:
+  kbuild-output:
+    description: 'Path to the kernel build output'
+    required: true
+  repo-root:
+    description: "Path to the root of the kernel repository"
+    required: true
+  arch:
+    required: true
+  toolchain:
+    required: true
+outputs:
+  archive-name:
+    description: 'Artifacts tarball name'
+    value: ${{ steps.run-script.outputs.archive-name }}
+
+runs:
+  using: "composite"
+  steps:
+    - name: Run tar-artifacts.sh
+      id: run-script
+      env:
+        KBUILD_OUTPUT: ${{ inputs.kbuild-output }}
+        REPO_ROOT: ${{ inputs.repo-root }}
+      shell: bash
+      run:
+        ${GITHUB_ACTION_PATH}/tar-artifacts.sh "${{ inputs.arch }}" "${{ inputs.toolchain }}"

tar-artifacts/tar-artifacts.sh

@@ -0,0 +1,79 @@
+#!/bin/bash
+
+set -eux -o pipefail
+
+if [ ! -d "${REPO_ROOT:-}" ]; then
+  echo "REPO_ROOT must be a directory: ${REPO_ROOT}"
+  exit 1
+fi
+
+if [ ! -d "${KBUILD_OUTPUT:-}" ]; then
+  echo "KBUILD_OUTPUT must be a directory: ${KBUILD_OUTPUT}"
+  exit 1
+fi
+
+ARCHIVE_BPF_SELFTESTS="${ARCHIVE_BPF_SELFTESTS:-true}"
+ARCHIVE_MAKE_HELPERS="${ARCHIVE_MAKE_HELPERS:-}"
+ARCHIVE_SCHED_EXT_SELFTESTS="${ARCHIVE_SCHED_EXT_SELFTESTS:-}"
+
+arch="${1}"
+toolchain="${2}"
+
+tarball="vmlinux-${arch}-${toolchain}.tar"
+
+source "${GITHUB_ACTION_PATH}/../helpers.sh"
+
+# Strip debug information, which is excessively large (consuming
+# bandwidth) while not actually being used (the kernel does not use
+# DWARF to symbolize stacktraces).
+"${arch}"-linux-gnu-strip --strip-debug "${KBUILD_OUTPUT}"/vmlinux
+
+image_name=$(make ARCH="$(platform_to_kernel_arch "${arch}")" -s image_name)
+kbuild_output_file_list=(
+  ".config"
+  "${image_name}"
+  "include/config/auto.conf"
+  "include/generated/autoconf.h"
+  "vmlinux"
+)
+
+tar -rf "${tarball}" -C "${KBUILD_OUTPUT}" \
+    --transform "s,^,kbuild-output/,"      \
+    "${kbuild_output_file_list[@]}"
+
+# In case artifacts are restored not to the kernel repo root,
+# package up a bunch of additional infrastructure to support running
+# 'make kernelrelease' and bpf tool checks later on.
+if [[ -n "${ARCHIVE_MAKE_HELPERS}" ]]; then
+  find "${REPO_ROOT}" -iname Makefile -printf '%P\n' \
+    | tar -rf "${tarball}" -C "${REPO_ROOT}" -T -
+  tar -rf "${tarball}" -C "${REPO_ROOT}" \
+    --exclude '*.o'                      \
+    --exclude '*.d'                      \
+    "scripts/"                           \
+    "tools/testing/selftests/bpf/"       \
+    "tools/include/"                     \
+    "tools/bpf/bpftool/"
+fi
+
+if [[ -n "${ARCHIVE_BPF_SELFTESTS}" ]]; then
+  # add .bpf.o files
+    find "${REPO_ROOT}/tools/testing/selftests/bpf" -name "*.bpf.o" -printf 'selftests/bpf/%P\n' \
+        | tar -rf "${tarball}" -C "${REPO_ROOT}/tools/testing" -T -
+  # add other relevant files
+  tar -rf "${tarball}" -C "${REPO_ROOT}/tools/testing" \
+      --exclude '*.cmd'    \
+      --exclude '*.d'      \
+      --exclude '*.h'      \
+      --exclude '*.o'      \
+      --exclude '*.output' \
+      selftests/bpf/
+fi
+
+if [[ -n "${ARCHIVE_SCHED_EXT_SELFTESTS}" ]]; then
+  tar -rf "${tarball}" -C "${REPO_ROOT}/tools/testing" selftests/sched_ext/
+fi
+
+zst_tarball="vmlinux-${arch}-${toolchain}.tar.zst"
+zstd -T0 -19 -i "${tarball}" -o "${zst_tarball}"
+echo "archive-name=$(realpath "${zst_tarball}")" >> $GITHUB_OUTPUT