ci: move to containers

This allows us to use different (and in particular, newer) Ubuntu images,
it is easier to move it to another CI and to use it locally by others.

This, in turn, gives us easy access to e.g. newer GCCs like 11.2 which may
spot other issues, like the one by the Intel CI the other day (which
I wanted to reproduce in the CI -- this commit includes enabling
the config option that triggered it).

It also allows us to drop `ci-bin`, since we get QEMU 6.0 from Ubuntu
and we can compile BusyBox too.

It should also avoid most networking issues since we rely only on content
from GitHub.

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

.github/workflows/ci.yaml

@@ -7,16 +7,15 @@ on:
 jobs:
   ci:
     runs-on: ubuntu-20.04
+    container: ghcr.io/rust-for-linux/ci
     timeout-minutes: 20
 
     strategy:
       matrix:
         arch: [arm, arm64, ppc64le, riscv64, x86_64]
         toolchain: [gcc, clang, llvm]
         config: [debug, release]
-        rustc: [1.58.0]
         output: [src] # [src, build]
-        install: [rustup] # [rustup, standalone]
         sysroot: [common] # [common, custom]
         lto: [none] # [none, thin]
 
@@ -42,71 +41,55 @@ jobs:
 
         # A few independent combinations to avoid exploding the matrix:
         #   - The other option for `output`.
-        #   - Different releases for `rustc`.
+        #   - Whether to use a custom sysroot.
         #   - Explicitly enabling `lto` on platforms which support LTO.
-        #   - The other three (`install`, `sysroot`) combinations
-        #     (they are interrelated, so the cross-product needs to be tested)
         include:
           - arch: arm64
             toolchain: gcc
             config: debug
-            rustc: 1.58.0
             output: build
-            install: rustup
             sysroot: custom
             lto: none
 
           - arch: arm64
             toolchain: llvm
             config: debug
-            rustc: 1.58.0
             output: build
-            install: rustup
             sysroot: custom
             lto: thin
 
           - arch: arm64
             toolchain: llvm
             config: release
-            rustc: 1.58.0
             output: build
-            install: rustup
             sysroot: custom
             lto: thin
 
           - arch: ppc64le
             toolchain: clang
             config: release
-            rustc: 1.58.0
             output: build
-            install: standalone
             sysroot: common
             lto: none
 
           - arch: x86_64
             toolchain: llvm
             config: debug
-            rustc: 1.58.0
             output: build
-            install: standalone
             sysroot: custom
             lto: none
 
           - arch: x86_64
             toolchain: llvm
             config: debug
-            rustc: 1.58.0
             output: src
-            install: rustup
             sysroot: common
             lto: thin
 
           - arch: x86_64
             toolchain: llvm
             config: release
-            rustc: 1.58.0
             output: src
-            install: rustup
             sysroot: common
             lto: thin
 
@@ -120,7 +103,7 @@ jobs:
       # Setup: Github cache
       - uses: actions/cache@v2
         with:
-          path: ~/.ccache
+          path: /root/.ccache
           key: ${{ env.MATRIX_NAME }}-ccache-${{ github.run_id }}
           restore-keys: |
               ${{ env.MATRIX_NAME }}-ccache-
@@ -169,7 +152,7 @@ jobs:
           echo 'QEMU_ARGS=-bios /usr/lib/riscv64-linux-gnu/opensbi/generic/fw_jump.elf' >> $GITHUB_ENV
 
       - if: matrix.toolchain == 'clang'
-        run: echo 'MAKE_TOOLCHAIN=CC=clang-12' >> $GITHUB_ENV
+        run: echo 'MAKE_TOOLCHAIN=CC=clang' >> $GITHUB_ENV
       - if: matrix.toolchain == 'llvm'
         run: echo 'MAKE_TOOLCHAIN=LLVM=1' >> $GITHUB_ENV
 
@@ -184,104 +167,36 @@ jobs:
           echo 'MAKE_OUTPUT=O=build' >> $GITHUB_ENV
           echo 'BUILD_DIR=build/' >> $GITHUB_ENV
 
+      # Setup: Rust
+      #
+      # `rustc` via `rustup` needs to find the `settings.xml` file,
+      # but GitHub overrides `$HOME` for containers. Undo it, even
+      # if it makes GitHub show some Docker warnings.
+      # See https://github.com/actions/runner/issues/863.
+      #
+      # Note that the commands need to be in their own `run` to have
+      # `$HOME` visible for the second one.
+      - run: echo 'HOME=/root' >> $GITHUB_ENV
+      - run: echo "$HOME/.cargo/bin" >> $GITHUB_PATH
+
       - if: matrix.sysroot == 'custom'
         run: |
           echo 'RUSTC_SYSROOT=--sysroot=$HOME/sysroot' >> $GITHUB_ENV
           echo "MAKE_SYSROOT=KRUSTFLAGS=--sysroot=$HOME/sysroot" >> $GITHUB_ENV
 
-      # Setup: custom pre-built binaries folder
-      - run: |
-          mkdir bin
-          echo $(pwd)/bin >> $GITHUB_PATH
-
-      # Setup: LLVM
-      - run: curl https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
-      # Retry to be resilient to intermittent network issues
-      - run: |
-          sudo add-apt-repository 'deb http://apt.llvm.org/focal/ llvm-toolchain-focal-12 main' ||
-            sudo add-apt-repository 'deb http://apt.llvm.org/focal/ llvm-toolchain-focal-12 main' ||
-            sudo add-apt-repository 'deb http://apt.llvm.org/focal/ llvm-toolchain-focal-12 main'
-      - run: sudo apt-get update -y
-      - run: sudo apt-get install -y llvm-12 clang-12 lld-12 --fix-missing
-      - run: echo $(llvm-config-12 --bindir) >> $GITHUB_PATH
-
-      # Setup: GCC
-      - if: matrix.arch == 'arm'
-        run: sudo apt-get install -y gcc-arm-linux-gnueabi lzop
-      - if: matrix.arch == 'arm64'
-        run: sudo apt-get install -y gcc-aarch64-linux-gnu
-      - if: matrix.arch == 'ppc64le'
-        run: sudo apt-get install -y gcc-powerpc64le-linux-gnu
-      - if: matrix.arch == 'riscv64'
-        run: sudo apt-get install -y gcc-riscv64-linux-gnu
-
-      # Setup OpenSBI
-      - if: matrix.arch == 'riscv64'
-        run: sudo apt-get install -y opensbi
-
-      # Setup: libelf
-      - run: sudo apt-get install -y libelf-dev
-
-      # Setup: QEMU
-      - if: matrix.arch == 'x86_64'
-        run: sudo apt-get install -y qemu-system-x86
-      - if: matrix.arch == 'arm' || matrix.arch == 'arm64'
-        run: sudo apt-get install -y qemu-system-arm
-      - if: matrix.arch == 'ppc64le'
-        run: sudo apt-get install -y qemu-system-ppc
-      - if: matrix.arch == 'riscv64'
-        run: |
-          curl -o bin/qemu-system-riscv64 https://raw.githubusercontent.com/Rust-for-Linux/ci-bin/master/qemu-6.0.0/bin/qemu-system-riscv64
-          chmod u+x bin/qemu-system-riscv64
-
-      # Setup: rustc
-      - if: matrix.install == 'rustup'
-        run: |
-          rustup default ${{ matrix.rustc }}
-          rustup component add rustfmt
-      - if: matrix.install == 'standalone'
-        run: |
-          curl https://static.rust-lang.org/dist/rust-${{ matrix.rustc }}-x86_64-unknown-linux-gnu.tar.gz | tar xz
-          rust-${{ matrix.rustc }}-x86_64-unknown-linux-gnu/install.sh --without=rust-docs --prefix=$HOME/rustc
-          echo $HOME/rustc/bin >> $GITHUB_PATH
-
       # Setup: rustc native libs
       - if: matrix.sysroot == 'custom'
         run: |
           mkdir $(rustc ${{ env.RUSTC_SYSROOT }} --print sysroot)
           ln -s $(rustc --print sysroot)/lib $(rustc ${{ env.RUSTC_SYSROOT }} --print sysroot)/lib
 
-      # Setup: rustc source
-      - if: matrix.install == 'rustup' && matrix.sysroot == 'common'
-        run: rustup component add rust-src
-      - if: matrix.install != 'rustup' || matrix.sysroot != 'common'
-        run: |
-          git clone -n https://github.com/rust-lang/rust $(rustc ${{ env.RUSTC_SYSROOT }} --print sysroot)/lib/rustlib/src/rust
-          cd $(rustc ${{ env.RUSTC_SYSROOT }} --print sysroot)/lib/rustlib/src/rust
-          git checkout $(rustc -vV | grep -F 'commit-hash' | awk '{print $2}')
-          git submodule update --init library
-
-      # Setup: clippy
-      - run: rustup component add clippy
-
-      # Setup: bindgen
-      - run: |
-          curl -o bin/bindgen https://raw.githubusercontent.com/Rust-for-Linux/ci-bin/master/bindgen-0.56.0/bin/bindgen
-          chmod u+x bin/bindgen
-
       # Setup: ccache
       - run: |
-          sudo apt-get install ccache
           echo '/usr/lib/ccache:$PATH' >> $GITHUB_PATH
 
       # Setup: Check existing ccache
       - run: ccache -s
 
-      # Setup: busybox
-      - run: git clone --depth 1 -b 1_30_1 https://github.com/mirror/busybox
-      - run: mv .github/workflows/busybox.config busybox/.config
-      - run: cd busybox && make ${{ env.MAKE_CROSS_COMPILE }} -j3
-
       # Setup: module parameters test
       - run: |
           cp samples/rust/rust_module_parameters.rs samples/rust/rust_module_parameters_builtin_default.rs
@@ -319,9 +234,12 @@ jobs:
       # Make sure `CONFIG_WERROR` was enabled
       - run: grep -F 'CONFIG_WERROR=y' ${{ env.BUILD_DIR }}.config
 
-      # Run
-      - run: ${{ env.BUILD_DIR }}usr/gen_init_cpio .github/workflows/qemu-initramfs.desc > qemu-initramfs.img
+      # Prepare image
+      - run: |
+          mv $HOME/busybox-${{ matrix.arch }} busybox
+          ${{ env.BUILD_DIR }}usr/gen_init_cpio .github/workflows/qemu-initramfs.desc > qemu-initramfs.img
 
+      # Run
       - run: |
           qemu-system-${{ env.QEMU_ARCH }} \
             ${{ env.QEMU_ARGS }} \

.github/workflows/kernel-arm-debug.config

@@ -1829,4 +1829,5 @@ CONFIG_RUST_BUILD_ASSERT_DENY=y
 # end of Rust hacking
 # end of Kernel hacking
 
-CONFIG_WERROR=y
+CONFIG_WERROR=y
+CONFIG_ZERO_CALL_USED_REGS=y

.github/workflows/kernel-arm64-debug-thinlto.config

@@ -1478,4 +1478,5 @@ CONFIG_RUST_BUILD_ASSERT_DENY=y
 # end of Rust hacking
 # end of Kernel hacking
 
-CONFIG_WERROR=y
+CONFIG_WERROR=y
+CONFIG_ZERO_CALL_USED_REGS=y

.github/workflows/kernel-arm64-debug.config

@@ -1473,4 +1473,5 @@ CONFIG_RUST_BUILD_ASSERT_DENY=y
 # end of Rust hacking
 # end of Kernel hacking
 
-CONFIG_WERROR=y
+CONFIG_WERROR=y
+CONFIG_ZERO_CALL_USED_REGS=y

.github/workflows/kernel-ppc64le-debug.config

@@ -1594,4 +1594,5 @@ CONFIG_RUST_BUILD_ASSERT_ALLOW=y
 # end of Rust hacking
 # end of Kernel hacking
 
-CONFIG_WERROR=y
+CONFIG_WERROR=y
+CONFIG_ZERO_CALL_USED_REGS=y

.github/workflows/kernel-riscv64-debug.config

@@ -1322,4 +1322,5 @@ CONFIG_RUST_BUILD_ASSERT_ALLOW=y
 # end of Rust hacking
 # end of Kernel hacking
 
-CONFIG_WERROR=y
+CONFIG_WERROR=y
+CONFIG_ZERO_CALL_USED_REGS=y

.github/workflows/kernel-x86_64-debug-thinlto.config

@@ -1545,4 +1545,5 @@ CONFIG_RUST_BUILD_ASSERT_ALLOW=y
 # end of Rust hacking
 # end of Kernel hacking
 
-CONFIG_WERROR=y
+CONFIG_WERROR=y
+CONFIG_ZERO_CALL_USED_REGS=y

.github/workflows/kernel-x86_64-debug.config

@@ -1548,4 +1548,5 @@ CONFIG_RUST_BUILD_ASSERT_ALLOW=y
 # end of Rust hacking
 # end of Kernel hacking
 
-CONFIG_WERROR=y
+CONFIG_WERROR=y
+CONFIG_ZERO_CALL_USED_REGS=y

.github/workflows/qemu-initramfs.desc

@@ -1,7 +1,7 @@
 dir     /bin                                          0755 0 0
 dir     /sys                                          0755 0 0
 dir     /dev                                          0755 0 0
-file    /bin/busybox  busybox/busybox                 0755 0 0
+file    /bin/busybox  busybox                         0755 0 0
 slink   /bin/sh       /bin/busybox                    0755 0 0
 file    /init         .github/workflows/qemu-init.sh  0755 0 0