Add cross-compilation to CI

Updates the README to use cargo target config instead of RUSTFLAGS to
avoid setting the linker for ebpf in cargo-in-cargo.

.github/workflows/ci.yml

@@ -21,12 +21,12 @@ concurrency:
 
 jobs:
   build:
-    runs-on: ubuntu-22.04
     strategy:
       fail-fast: false
       matrix:
+        runner:
+          - ubuntu-latest # x86
         rust:
-          - stable
           - 1.80.1
         program:
           - kprobe
@@ -48,6 +48,15 @@ jobs:
           - raw_tracepoint
           - tp_btf
           - tracepoint
+        include:
+          - runner: macos-13 # x86
+            rust: 1.80.1
+            program: kprobe
+          - runner: macos-14 # arm64
+            rust: 1.80.1
+            program: kprobe
+
+    runs-on: ${{ matrix.runner }}
 
     steps:
       - uses: actions/checkout@v4
@@ -57,6 +66,21 @@ jobs:
           components: rust-src,rustfmt
 
       - uses: dtolnay/rust-toolchain@master
+        if: runner.os == 'macOS' && runner.arch == 'X64'
+        with:
+          toolchain: ${{ matrix.rust }}
+          targets: x86_64-unknown-linux-musl
+          components: clippy
+
+      - uses: dtolnay/rust-toolchain@master
+        if: runner.os == 'macOS' && runner.arch == 'ARM64'
+        with:
+          toolchain: ${{ matrix.rust }}
+          targets: aarch64-unknown-linux-musl
+          components: clippy
+
+      - uses: dtolnay/rust-toolchain@master
+        if: runner.os == 'Linux'
         with:
           toolchain: ${{ matrix.rust }}
           components: clippy
@@ -65,8 +89,18 @@ jobs:
 
       - uses: taiki-e/install-action@v2
         with:
-          tool: bpf-linker,cargo-generate
+          tool: cargo-generate
+
+      - run: brew install filosottile/musl-cross/musl-cross llvm
+        if: runner.os == 'macos'
+
+      - run: cargo install bpf-linker --git https://github.com/aya-rs/bpf-linker.git --no-default-features
+        if: runner.os == 'macos'
+
+      - run: cargo install bpf-linker --git https://github.com/aya-rs/bpf-linker.git
+        if: runner.os == 'Linux'
+
+      - run: sudo apt update && sudo apt install expect
+        if: runner.os == 'Linux'
 
-      - run: sudo apt update
-      - run: sudo apt install expect
       - run: ./test.sh ${{ github.workspace }} ${{ matrix.program }}

README.md

@@ -21,11 +21,10 @@ experience; this compromise necessitates the use of `xtask` to actually build th
 
 Cross compilation should work on both Intel and Apple Silicon Macs.
 
-```bash
+```shell
-AYA_BUILD_EBPF=true \
+AYA_BUILD_EBPF=true CC=${ARCH}-linux-musl-gcc cargo build --package {{project-name}} --release \
-CC=${ARCH}-linux-musl-gcc \
+  --target=${ARCH}-unknown-linux-musl \
-RUSTFLAGS="-C linker=${ARCH}-linux-musl-gcc" \
+  --config=target.${ARCH}-unknown-linux-musl.linker=\"${ARCH}-linux-musl-gcc\"
-  cargo build --package {{project-name}} --release --target=${ARCH}-unknown-linux-musl
 ```
 The cross-compiled program `target/${ARCH}-unknown-linux-musl/release/{{project-name}}` can be
 copied to a Linux server or VM and run there.

test.sh

@@ -14,7 +14,7 @@ if [ -z "${PROG_TYPE}" ]; then
 fi
 CRATE_NAME=aya-test-crate
 
-case "${PROG_TYPE}" in
+case ${PROG_TYPE} in
 "cgroup_sockopt")
   ADDITIONAL_ARGS=(-d sockopt_target=getsockopt)
   ;;
@@ -61,6 +61,18 @@ pushd "${TMP_DIR}"
 cargo generate --path "${TEMPLATE_DIR}" -n "${CRATE_NAME}" -d program_type="${PROG_TYPE}" "${ADDITIONAL_ARGS[@]}"
 pushd "${CRATE_NAME}"
 
+OS=$(uname)
+case $OS in
+"Darwin")
+  ARCH=$(uname -m)
+  if [[ "$ARCH" == "arm64" ]]; then
+    ARCH="aarch64"
+  fi
+  AYA_BUILD_EBPF=true CC=${ARCH}-linux-musl-gcc cargo build --package "${CRATE_NAME}" --release \
+    --target="${ARCH}"-unknown-linux-musl \
+    --config=target."${ARCH}"-unknown-linux-musl.linker=\""${ARCH}"-linux-musl-gcc\"
+  ;;
+"Linux")
   cargo +nightly fmt --all -- --check
   cargo build --package "${CRATE_NAME}"
   cargo build --package "${CRATE_NAME}" --release
@@ -93,3 +105,9 @@ expect <<EOF
       eof { }
     }
 EOF
+  ;;
+*)
+  echo "Unsupported OS: ${OS}"
+  exit 1
+  ;;
+esac

{{project-name}}/src/main.rs

@@ -205,8 +205,9 @@ async fn main() -> anyhow::Result<()> {
     program.attach("{{tracepoint_name}}")?;
     {%- endcase %}
 
+    let ctrl_c = signal::ctrl_c();
     println!("Waiting for Ctrl-C...");
-    signal::ctrl_c().await?;
+    ctrl_c.await?;
     println!("Exiting...");
 
     Ok(())