pkg/bisect: add ccache option

Add option to use ccache in kernel builds.

Signed-off-by: Jouni Hogander <jouni.hoegander@partner.bmw.de>

pkg/bisect/bisect.go

@@ -22,6 +22,7 @@ type Config struct {
 	Trace     io.Writer
 	Fix       bool
 	BinDir    string
+	Ccache    string
 	DebugDir  string
 	Timeout   time.Duration
 	Kernel    KernelConfig
@@ -448,7 +449,7 @@ func (env *env) build() (*vcs.Commit, string, error) {
 		return nil, "", fmt.Errorf("kernel clean failed: %v", err)
 	}
 	kern := &env.cfg.Kernel
-	_, kernelSign, err := env.inst.BuildKernel(bisectEnv.Compiler, kern.Userspace,
+	_, kernelSign, err := env.inst.BuildKernel(bisectEnv.Compiler, env.cfg.Ccache, kern.Userspace,
 		kern.Cmdline, kern.Sysctl, bisectEnv.KernelConfig)
 	if kernelSign != "" {
 		env.log("kernel signature: %v", kernelSign)

pkg/bisect/bisect_test.go

@@ -32,7 +32,7 @@ func (env *testEnv) BuildSyzkaller(repo, commit string) error {
 	return nil
 }
 
-func (env *testEnv) BuildKernel(compilerBin, userspaceDir, cmdlineFile, sysctlFile string,
+func (env *testEnv) BuildKernel(compilerBin, cCache, userspaceDir, cmdlineFile, sysctlFile string,
 	kernelConfig []byte) (string, string, error) {
 	commit := env.headCommit()
 	configHash := hash.String(kernelConfig)

pkg/build/build.go

@@ -26,6 +26,7 @@ type Params struct {
 	KernelDir    string
 	OutputDir    string
 	Compiler     string
+	Ccache       string
 	UserspaceDir string
 	CmdlineFile  string
 	SysctlFile   string

pkg/build/linux.go

@@ -65,7 +65,24 @@ func (linux) buildKernel(params *Params) error {
 	case "ppc64le":
 		target = "zImage"
 	}
-	if err := runMake(params.KernelDir, target, "CC="+params.Compiler); err != nil {
+
+	ccParam := params.Compiler
+	if params.Ccache != "" {
+		ccParam = params.Ccache + " " + ccParam
+		// Ensure CONFIG_GCC_PLUGIN_RANDSTRUCT doesn't prevent ccache usage.
+		// See /Documentation/kbuild/reproducible-builds.rst.
+		gccPluginsDir := filepath.Join(params.KernelDir, "scripts", "gcc-plugins")
+		if osutil.IsExist(gccPluginsDir) {
+			err := osutil.WriteFile(filepath.Join(gccPluginsDir,
+				"randomize_layout_seed.h"),
+				[]byte("const char *randstruct_seed = "+
+					"\"e9db0ca5181da2eedb76eba144df7aba4b7f9359040ee58409765f2bdc4cb3b8\";"))
+			if err != nil {
+				return err
+			}
+		}
+	}
+	if err := runMake(params.KernelDir, target, "CC="+ccParam); err != nil {
 		return err
 	}
 	vmlinux := filepath.Join(params.KernelDir, "vmlinux")

pkg/instance/instance.go

@@ -29,7 +29,7 @@ import (
 
 type Env interface {
 	BuildSyzkaller(string, string) error
-	BuildKernel(string, string, string, string, []byte) (string, string, error)
+	BuildKernel(string, string, string, string, string, []byte) (string, string, error)
 	Test(numVMs int, reproSyz, reproOpts, reproC []byte) ([]error, error)
 }
 
@@ -94,7 +94,7 @@ func (env *env) BuildSyzkaller(repo, commit string) error {
 	return nil
 }
 
-func (env *env) BuildKernel(compilerBin, userspaceDir, cmdlineFile, sysctlFile string, kernelConfig []byte) (
+func (env *env) BuildKernel(compilerBin, ccacheBin, userspaceDir, cmdlineFile, sysctlFile string, kernelConfig []byte) (
 	string, string, error) {
 	imageDir := filepath.Join(env.cfg.Workdir, "image")
 	params := &build.Params{
@@ -104,6 +104,7 @@ func (env *env) BuildKernel(compilerBin, userspaceDir, cmdlineFile, sysctlFile s
 		KernelDir:    env.cfg.KernelSrc,
 		OutputDir:    imageDir,
 		Compiler:     compilerBin,
+		Ccache:       ccacheBin,
 		UserspaceDir: userspaceDir,
 		CmdlineFile:  cmdlineFile,
 		SysctlFile:   sysctlFile,

pkg/vcs/linux.go

@@ -124,6 +124,7 @@ func (ctx *linux) EnvForCommit(binDir, commit string, kernelConfig []byte) (*Bis
 			return nil, err
 		}
 	}
+
 	return env, nil
 }
 

syz-ci/jobs.go

@@ -405,6 +405,7 @@ func (jp *JobProcessor) bisect(job *Job, mgrcfg *mgrconfig.Config) error {
 		Timeout: 8 * time.Hour,
 		Fix:     req.Type == dashapi.JobBisectFix,
 		BinDir:  jp.cfg.BisectBinDir,
+		Ccache:  jp.cfg.Ccache,
 		Kernel: bisect.KernelConfig{
 			Repo:           mgr.mgrcfg.Repo,
 			Branch:         mgr.mgrcfg.Branch,
@@ -527,8 +528,8 @@ func (jp *JobProcessor) testPatch(job *Job, mgrcfg *mgrconfig.Config) error {
 	}
 
 	log.Logf(0, "job: building kernel...")
-	kernelConfig, _, err := env.BuildKernel(mgr.mgrcfg.Compiler, mgr.mgrcfg.Userspace, mgr.mgrcfg.KernelCmdline,
+	kernelConfig, _, err := env.BuildKernel(mgr.mgrcfg.Compiler, mgr.mgrcfg.Ccache, mgr.mgrcfg.Userspace,
-		mgr.mgrcfg.KernelSysctl, req.KernelConfig)
+		mgr.mgrcfg.KernelCmdline, mgr.mgrcfg.KernelSysctl, req.KernelConfig)
 	if err != nil {
 		return err
 	}

syz-ci/manager.go

@@ -301,6 +301,7 @@ func (mgr *Manager) build(kernelCommit *vcs.Commit) error {
 		KernelDir:    mgr.kernelDir,
 		OutputDir:    tmpDir,
 		Compiler:     mgr.mgrcfg.Compiler,
+		Ccache:       mgr.mgrcfg.Ccache,
 		UserspaceDir: mgr.mgrcfg.Userspace,
 		CmdlineFile:  mgr.mgrcfg.KernelCmdline,
 		SysctlFile:   mgr.mgrcfg.KernelSysctl,

syz-ci/syz-ci.go

@@ -93,6 +93,7 @@ type Config struct {
 	// GCS path to upload coverage reports from managers (optional).
 	CoverUploadPath string           `json:"cover_upload_path"`
 	BisectBinDir    string           `json:"bisect_bin_dir"`
+	Ccache          string           `json:"ccache"`
 	Managers        []*ManagerConfig `json:"managers"`
 }
 
@@ -106,6 +107,7 @@ type ManagerConfig struct {
 	RepoAlias    string `json:"repo_alias"`
 	Branch       string `json:"branch"` // Defaults to "master".
 	Compiler     string `json:"compiler"`
+	Ccache       string `json:"ccache"`
 	Userspace    string `json:"userspace"`
 	KernelConfig string `json:"kernel_config"`
 	// Baseline config for bisection, see pkg/bisect.KernelConfig.BaselineConfig.

tools/syz-bisect/bisect.go

@@ -46,6 +46,7 @@ type Config struct {
 	// gcc versions. A working archive can be downloaded from:
 	// https://storage.googleapis.com/syzkaller/bisect_bin.tar.gz
 	BinDir        string `json:"bin_dir"`
+	Ccache        string `json:"ccache"`
 	KernelRepo    string `json:"kernel_repo"`
 	KernelBranch  string `json:"kernel_branch"`
 	SyzkallerRepo string `json:"syzkaller_repo"`
@@ -86,6 +87,7 @@ func main() {
 		Trace:    os.Stdout,
 		Fix:      *flagFix,
 		BinDir:   mycfg.BinDir,
+		Ccache:   mycfg.Ccache,
 		DebugDir: *flagCrash,
 		Kernel: bisect.KernelConfig{
 			Repo:      mycfg.KernelRepo,

tools/syz-testbuild/testbuild.go

@@ -128,7 +128,7 @@ func test(repo vcs.Repo, bisecter vcs.Bisecter, kernelConfig []byte, env instanc
 	if err := build.Clean(*flagOS, *flagArch, vmType, *flagKernelSrc); err != nil {
 		fail(err)
 	}
-	_, _, err = env.BuildKernel(bisectEnv.Compiler, *flagUserspace,
+	_, _, err = env.BuildKernel(bisectEnv.Compiler, "", *flagUserspace,
 		*flagKernelCmdline, *flagKernelSysctl, bisectEnv.KernelConfig)
 	if err != nil {
 		if verr, ok := err.(*osutil.VerboseError); ok {