Build the latest LTS kernel versions in CI

Author: gsingh93

.github/workflows/build.yml

@@ -8,7 +8,7 @@ jobs:
       matrix:
         # TODO: Add 20.04
         os: [ubuntu-22.04]
-        kernel: [{ack: 0, version: 5.10.164}, {ack: 0, version: 5.15.89}, {ack: 0, version: 6.1.7}, {ack: 1, version: android13-5.10-lts}]
+        kernel: [{ack: 0, version: 5.10.y}, {ack: 0, version: 5.15.y}, {ack: 0, version: 6.1.y}, {ack: 1, version: android13-5.10-lts}]
         arch: [arm64, x86_64]
     runs-on: ${{ matrix.os }}
     timeout-minutes: 100
@@ -49,11 +49,28 @@ jobs:
         echo "KERNEL_TYPE=$KERNEL_TYPE" >> $GITHUB_OUTPUT
         echo "KERNEL_IMAGE=$KERNEL_IMAGE" >> $GITHUB_OUTPUT
 
+    - name: Get real kernel version
+      run: |
+        LINUX_URL=https://cdn.kernel.org/pub/linux/kernel
+        VERSION="${{ matrix.kernel.version }}"
+        first_char=${VERSION:0:1}
+        last_char=${VERSION: -1:1}
+        if [ $last_char == y ]; then
+          major_minor=${VERSION: 0:-1}
+          VERSION=$(curl -s $LINUX_URL/v${first_char}.x/ \
+            | sed -e 's/<[^>]*>//g' \
+            | grep -oP "linux-${major_minor}[0-9]+" \
+            | sort -r -V \
+            | head -n1 \
+            | cut -d '-' -f2)
+        fi
+        echo "VERSION=$VERSION" >> $GITHUB_ENV
+
     - name: Cache kernel image
       id: cache-kernel
       uses: actions/cache@v3
       with:
-        key: ${{ matrix.kernel.version }}-${{ matrix.arch }}
+        key: ${{ env.VERSION }}-${{ matrix.arch }}
         path: |
           ${{ steps.vars.outputs.KERNEL_IMAGE }}
           ${{ steps.vars.outputs.OUT_DIR }}/vmlinux
@@ -68,11 +85,11 @@ jobs:
         os: ${{ matrix.os }}
         arch: ${{ matrix.arch }}
         ack: ${{ matrix.kernel.ack }}
-        kernel-version: ${{ matrix.kernel.version }}
+        kernel-version: ${{ env.VERSION }}
 
     - name: Rename kernel images
       run: |
-        SUFFIX=${{ steps.vars.outputs.KERNEL_TYPE }}-${{ matrix.kernel.version }}-${{ matrix.arch }}
+        SUFFIX=${{ steps.vars.outputs.KERNEL_TYPE }}-${{ env.VERSION }}-${{ matrix.arch }}
         cp ${{ steps.vars.outputs.KERNEL_IMAGE }} ${{ steps.vars.outputs.KERNEL_IMAGE }}-$SUFFIX
         cp ${{ steps.vars.outputs.OUT_DIR }}/vmlinux ${{ steps.vars.outputs.OUT_DIR }}/vmlinux-$SUFFIX
 
@@ -95,7 +112,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        kernel: [{ack: 0, version: 5.10.164}, {ack: 0, version: 5.15.89}, {ack: 0, version: 6.1.7}, {ack: 1, version: android13-5.10-lts}]
+        kernel: [{ack: 0, version: 5.10.y}, {ack: 0, version: 5.15.y}, {ack: 0, version: 6.1.y}, {ack: 1, version: android13-5.10-lts}]
         arch: [arm64, x86_64]
     runs-on: ubuntu-22.04
     env:
@@ -117,6 +134,23 @@ jobs:
       shell: bash
       run: sudo apt update && sudo apt install -y qemu-system-arm
 
+    - name: Get real kernel version
+      run: |
+        LINUX_URL=https://cdn.kernel.org/pub/linux/kernel
+        VERSION="${{ matrix.kernel.version }}"
+        first_char=${VERSION:0:1}
+        last_char=${VERSION: -1:1}
+        if [ $last_char == y ]; then
+          major_minor=${VERSION: 0:-1}
+          VERSION=$(curl -s $LINUX_URL/v${first_char}.x/ \
+            | sed -e 's/<[^>]*>//g' \
+            | grep -oP "linux-${major_minor}[0-9]+" \
+            | sort -r -V \
+            | head -n1 \
+            | cut -d '-' -f2)
+        fi
+        echo "VERSION=$VERSION" >> $GITHUB_ENV
+
     - name: Set output variables
       id: vars
       run: |
@@ -128,7 +162,7 @@ jobs:
           KERNEL_TYPE=ack
         fi
 
-        SUFFIX=$KERNEL_TYPE-${{ matrix.kernel.version }}-${{ matrix.arch }}
+        SUFFIX=$KERNEL_TYPE-${{ env.VERSION }}-${{ matrix.arch }}
 
         if [ $ARCH == x86_64 ]; then
           IMAGE_NAME=bzImage-$SUFFIX

scripts/download_linux.sh

@@ -28,7 +28,12 @@ if [ $ACK -eq 0 ]; then
     last_char=${VERSION: -1:1}
     if [ $last_char == y ]; then
         major_minor=${VERSION: 0:-1}
-        VERSION=$(curl -s $LINUX_URL/v${first_char}.x/ | sed -e 's/<[^>]*>//g' | grep -oP "linux-${major_minor}[0-9]+" | sort -r -V | head -n1 | cut -d '-' -f2)
+        VERSION=$(curl -s $LINUX_URL/v${first_char}.x/ \
+                      | sed -e 's/<[^>]*>//g' \
+                      | grep -oP "linux-${major_minor}[0-9]+" \
+                      | sort -r -V \
+                      | head -n1 \
+                      | cut -d '-' -f2)
     fi
 
     echo "Downloading kernel version $VERSION"