1 files changed, 160 insertions, 0 deletions
diff --git a/pkg/build/cuttlefish.go b/pkg/build/cuttlefish.go
new file mode 100644
index 000000000..42ec8af26
--- /dev/null
+++ b/pkg/build/cuttlefish.go
@@ -0,0 +1,160 @@
+// Copyright 2022 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package build
+
+import (
+	"archive/tar"
+	"compress/gzip"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/google/syzkaller/pkg/osutil"
+)
+
+const (
+	kernelConfig = "common/build.config.gki_kasan.x86_64"
+	moduleConfig = "common-modules/virtual-device/build.config.virtual_device_kasan.x86_64"
+	bazelTarget  = "//common-modules/virtual-device:virtual_device_x86_64_dist"
+)
+
+type cuttlefish struct{}
+
+func (c cuttlefish) runBuild(kernelDir, buildConfig string) error {
+	cmd := osutil.Command("build/build.sh")
+	cmd.Dir = kernelDir
+	cmd.Env = append(cmd.Env, "OUT_DIR=out", "DIST_DIR=dist", fmt.Sprintf("BUILD_CONFIG=%s", buildConfig))
+
+	_, err := osutil.Run(time.Hour, cmd)
+	return err
+}
+
+func (c cuttlefish) runBazel(kernelDir string) error {
+	cmd := osutil.Command("tools/bazel", "run", "--kasan", bazelTarget, "--", "--dist_dir=dist")
+	cmd.Dir = kernelDir
+	_, err := osutil.Run(time.Hour, cmd)
+	return err
+}
+
+func (c cuttlefish) readCompiler(archivePath string) (string, error) {
+	f, err := os.Open(archivePath)
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+
+	gr, err := gzip.NewReader(f)
+	if err != nil {
+		return "", err
+	}
+	defer gr.Close()
+
+	tr := tar.NewReader(gr)
+
+	h, err := tr.Next()
+	for ; err == nil; h, err = tr.Next() {
+		if filepath.Base(h.Name) == "compile.h" {
+			bytes, err := ioutil.ReadAll(tr)
+			if err != nil {
+				return "", err
+			}
+			result := linuxCompilerRegexp.FindSubmatch(bytes)
+			if result == nil {
+				return "", fmt.Errorf("include/generated/compile.h does not contain build information")
+			}
+
+			return string(result[1]), nil
+		}
+	}
+
+	return "", fmt.Errorf("archive %s doesn't contain include/generated/compile.h", archivePath)
+}
+
+func (c cuttlefish) build(params Params) (ImageDetails, error) {
+	var details ImageDetails
+
+	if params.CmdlineFile != "" {
+		return details, fmt.Errorf("cmdline file is not supported for android cuttlefish images")
+	}
+	if params.SysctlFile != "" {
+		return details, fmt.Errorf("sysctl file is not supported for android cuttlefish images")
+	}
+
+	var config string
+	var err error
+	// Default to build.sh if compiler is not specified.
+	if params.Compiler == "bazel" {
+		if err := c.runBazel(params.KernelDir); err != nil {
+			return details, fmt.Errorf("failed to build kernel: %s", err)
+		}
+		// Find the .config file; it is placed in a temporary output directory during the build.
+		cmd := osutil.Command("find", ".", "-wholename", "*virtual_device_x86_64_config/out_dir/.config")
+		cmd.Dir = params.KernelDir
+		configBytes, err := osutil.Run(time.Minute, cmd)
+		if err != nil {
+			return details, fmt.Errorf("failed to find build config: %v", err)
+		}
+		config = filepath.Join(params.KernelDir, strings.TrimSpace(string(configBytes)))
+	} else {
+		if err := c.runBuild(params.KernelDir, kernelConfig); err != nil {
+			return details, fmt.Errorf("failed to build kernel: %s", err)
+		}
+		if err := c.runBuild(params.KernelDir, moduleConfig); err != nil {
+			return details, fmt.Errorf("failed to build modules: %s", err)
+		}
+		config = filepath.Join(params.KernelDir, "out", "common", ".config")
+	}
+
+	buildDistDir := filepath.Join(params.KernelDir, "dist")
+	bzImage := filepath.Join(buildDistDir, "bzImage")
+	vmlinux := filepath.Join(buildDistDir, "vmlinux")
+	initramfs := filepath.Join(buildDistDir, "initramfs.img")
+
+	details.CompilerID, err = c.readCompiler(filepath.Join(buildDistDir, "kernel-headers.tar.gz"))
+	if err != nil {
+		return details, err
+	}
+
+	if err := embedFiles(params, func(mountDir string) error {
+		homeDir := filepath.Join(mountDir, "root")
+
+		if err := osutil.CopyFile(bzImage, filepath.Join(homeDir, "bzImage")); err != nil {
+			return err
+		}
+		if err := osutil.CopyFile(vmlinux, filepath.Join(homeDir, "vmlinux")); err != nil {
+			return err
+		}
+		if err := osutil.CopyFile(initramfs, filepath.Join(homeDir, "initramfs.img")); err != nil {
+			return err
+		}
+
+		return nil
+	}); err != nil {
+		return details, err
+	}
+
+	if err := osutil.CopyFile(vmlinux, filepath.Join(params.OutputDir, "obj", "vmlinux")); err != nil {
+		return details, err
+	}
+	if err := osutil.CopyFile(initramfs, filepath.Join(params.OutputDir, "obj", "initrd")); err != nil {
+		return details, err
+	}
+	if err := osutil.CopyFile(config, filepath.Join(params.OutputDir, "kernel.config")); err != nil {
+		return details, err
+	}
+
+	details.Signature, err = elfBinarySignature(vmlinux, params.Tracer)
+	if err != nil {
+		return details, fmt.Errorf("failed to generate signature: %s", err)
+	}
+
+	return details, nil
+}
+
+func (c cuttlefish) clean(kernelDir, targetArch string) error {
+	return osutil.RemoveAll(filepath.Join(kernelDir, "out"))
+}