Add in-kernel test runner
This adds a way to run tests inside the Smalltown kernel.
Improvements to the Bazel part of this are tracked in T726
Test Plan: Tested by intentionally failing the test.
X-Origin-Diff: phab/D485
GitOrigin-RevId: e4aad7f28d122d82a7fcb6699e678cbe022e2f73
diff --git a/core/tools/ktest/BUILD b/core/tools/ktest/BUILD
new file mode 100644
index 0000000..e139a18
--- /dev/null
+++ b/core/tools/ktest/BUILD
@@ -0,0 +1,62 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
+load("//core/tools/kconfig-patcher:kconfig-patcher.bzl", "kconfig_patch")
+
+go_library(
+ name = "go_default_library",
+ srcs = ["main.go"],
+ importpath = "git.monogon.dev/source/nexantic.git/core/tools/ktest",
+ visibility = ["//visibility:private"],
+)
+
+go_binary(
+ name = "ktest",
+ embed = [":go_default_library"],
+ pure = "on",
+ visibility = ["//visibility:public"],
+)
+
+kconfig_patch(
+ name = "testing-config",
+ src = "//third_party/linux:kernel-config",
+ out = "testing.config",
+ override_configs = {
+ # Unlock command line
+ "CONFIG_CMDLINE_OVERRIDE": "n",
+ "CONFIG_CMDLINE_BOOL": "n",
+ # Shave off 1 second from boot time
+ "CONFIG_SERIO_I8042": "",
+ "CONFIG_KEYBOARD_ATKBD": "",
+ "CONFIG_RTC_DRV_CMOS": "",
+ # Shave off an additional 18ms (half of the boot time)
+ "CONFIG_DEBUG_WX": "",
+ },
+)
+
+genrule(
+ name = "linux-testing",
+ srcs = [
+ "@linux//:all",
+ ":testing-config",
+ ],
+ outs = [
+ "linux-testing.elf",
+ ],
+ cmd = """
+ DIR=external/linux
+
+ mkdir $$DIR/.bin
+
+ cp $(location :testing-config) $$DIR/.config
+
+ (cd $$DIR && make -j $$(nproc) vmlinux >/dev/null)
+
+ cp $$DIR/vmlinux $@
+ """,
+ visibility = ["//visibility:public"],
+)
+
+filegroup(
+ name = "test-script",
+ srcs = ["run_ktest.sh"],
+ visibility = ["//visibility:public"],
+)
diff --git a/core/tools/ktest/ktest.bzl b/core/tools/ktest/ktest.bzl
new file mode 100644
index 0000000..03a7d5c
--- /dev/null
+++ b/core/tools/ktest/ktest.bzl
@@ -0,0 +1,61 @@
+# Copyright 2020 The Monogon Project Authors.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+Ktest provides a simple macro to run tests inside the normal Smalltown kernel
+"""
+
+def ktest(deps, tester, initramfs_extra, cmdline):
+ native.genrule(
+ name = "test_initramfs",
+ srcs = [
+ "//core/tools/ktestinit",
+ ] + deps + [tester],
+ outs = [
+ "initramfs.cpio.lz4",
+ ],
+ testonly = True,
+ cmd = """
+ $(location @linux//:gen_init_cpio) - <<- 'EOF' | lz4 -l > \"$@\"
+dir /dev 0755 0 0
+nod /dev/console 0600 0 0 c 5 1
+nod /dev/null 0644 0 0 c 1 3
+file /init $(location //core/tools/ktestinit) 0755 0 0
+file /tester $(location """ + tester + """) 0755 0 0
+""" + initramfs_extra + """
+EOF
+ """,
+ tools = [
+ "@linux//:gen_init_cpio",
+ ],
+ )
+
+ native.sh_test(
+ name = "ktest",
+ args = [
+ "$(location //core/tools/ktest)",
+ "$(location :test_initramfs)",
+ "$(location //core/tools/ktest:linux-testing)",
+ cmdline,
+ ],
+ size = "small",
+ srcs = ["//core/tools/ktest:test-script"],
+ data = [
+ "//core/tools/ktest",
+ ":test_initramfs",
+ "//core/tools/ktest:linux-testing",
+ ],
+ )
\ No newline at end of file
diff --git a/core/tools/ktest/main.go b/core/tools/ktest/main.go
new file mode 100644
index 0000000..67ad21a
--- /dev/null
+++ b/core/tools/ktest/main.go
@@ -0,0 +1,101 @@
+// Copyright 2020 The Monogon Project Authors.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// ktest is a test launcher for running tests inside a custom kernel and passes the results
+// back out.
+package main
+
+import (
+ "crypto/rand"
+ "flag"
+ "fmt"
+ "io"
+ "log"
+ "net"
+ "os"
+ "os/exec"
+ "path/filepath"
+)
+
+var (
+ kernelPath = flag.String("kernel-path", "", "Path of the Kernel ELF file")
+ initrdPath = flag.String("initrd-path", "", "Path of the initrd image")
+ cmdline = flag.String("cmdline", "", "Additional kernel command line options")
+)
+
+func main() {
+ flag.Parse()
+
+ // Create a temporary socket for passing data (currently only exit code)
+ // TODO: Land https://patchwork.ozlabs.org/project/qemu-devel/patch/1357671226-11334-1-git-send-email-alexander_barabash@mentor.com/
+ tmpDir := os.TempDir()
+ token := make([]byte, 16)
+ if _, err := io.ReadFull(rand.Reader, token); err != nil {
+ log.Fatal(err)
+ }
+
+ socketPath := filepath.Join(tmpDir, fmt.Sprintf("qemu-io-%x", token))
+ l, err := net.Listen("unix", socketPath)
+ if err != nil {
+ log.Fatal(err)
+ }
+ defer l.Close()
+ defer os.Remove(socketPath)
+
+ // Start a QEMU microvm (https://github.com/qemu/qemu/blob/master/docs/microvm.rst) with only
+ // a RNG and two character devices (one for console, one for OOB communication) attached.
+ cmd := exec.Command("qemu-system-x86_64", "-nodefaults", "-no-user-config", "-nographic", "-no-reboot",
+ "-accel", "kvm", "-cpu", "host",
+ "-M", "microvm,x-option-roms=off,pic=off,pit=off,rtc=off,isa-serial=off",
+ "-kernel", *kernelPath,
+ "-append", "reboot=t console=hvc0 quiet "+*cmdline,
+ "-initrd", *initrdPath,
+ "-device", "virtio-rng-device,max-bytes=1024,period=1000",
+ "-device", "virtio-serial-device,max_ports=2",
+ "-chardev", "stdio,id=con0", "-device", "virtconsole,chardev=con0",
+ "-chardev", "socket,id=io,path="+socketPath, "-device", "virtserialport,chardev=io",
+ )
+
+ cmd.Stdout = os.Stdout
+ cmd.Stderr = os.Stderr
+
+ exitCodeChan := make(chan uint8, 1)
+
+ go func() {
+ conn, err := l.Accept()
+ if err != nil {
+ log.Fatal(err)
+ }
+ defer conn.Close()
+
+ returnCode := make([]byte, 1)
+ if _, err := conn.Read(returnCode); err != nil && err != io.EOF {
+ log.Fatalf("Failed to read socket: %v", err)
+ }
+ exitCodeChan <- returnCode[0]
+ }()
+
+ if err := cmd.Run(); err != nil {
+ log.Fatalf("Failed to run QEMU: %v", err)
+ }
+ select {
+ case exitCode := <-exitCodeChan:
+ os.Exit(int(exitCode))
+ default:
+ log.Printf("Failed to get an error code back")
+ os.Exit(1)
+ }
+}
diff --git a/core/tools/ktest/run_ktest.sh b/core/tools/ktest/run_ktest.sh
new file mode 100755
index 0000000..02920a1
--- /dev/null
+++ b/core/tools/ktest/run_ktest.sh
@@ -0,0 +1,2 @@
+#!/bin/bash
+exec "$1" -initrd-path "$2" -kernel-path "$3" -cmdline "$4"
\ No newline at end of file