pkg/build: handle OOM-killed build error

Handle SIGKILL (exit code = 137) on osutil.Run() during Linux kernel image
building and return build.InfraError without reporting.

Fixes: https://github.com/google/syzkaller/issues/5317

2 files changed, 68 insertions, 1 deletions

diff --git a/pkg/build/build.go b/pkg/build/build.go
index bb6d089fd..ec47822a6 100644
--- a/pkg/build/build.go
+++ b/pkg/build/build.go
@@ -131,6 +131,18 @@ func (err *KernelError) Error() string {
 	return string(err.Report)
 }
 
+type InfraError struct {
+	Title  string
+	Output []byte
+}
+
+func (e InfraError) Error() string {
+	if len(e.Output) > 0 {
+		return fmt.Sprintf("%s: %s", e.Title, e.Output)
+	}
+	return e.Title
+}
+
 type builder interface {
 	build(params Params) (ImageDetails, error)
 	clean(kernelDir, targetArch string) error
@@ -208,6 +220,13 @@ func extractRootCause(err error, OS, kernelSrc string) error {
 	if len(reason) == 0 {
 		return err
 	}
+	// Don't report upon SIGKILL for Linux builds.
+	if OS == targets.Linux && string(reason) == "Killed" && verr.ExitCode == 137 {
+		return &InfraError{
+			Title:  string(reason),
+			Output: verr.Output,
+		}
+	}
 	kernelErr := &KernelError{
 		Report:     reason,
 		Output:     verr.Output,
@@ -313,6 +332,7 @@ var buildFailureCauses = [...]buildFailureCause{
 	{pattern: regexp.MustCompile(`^([a-zA-Z0-9_\-/.]+):[0-9]+:([0-9]+:)?.*(error|invalid|fatal|wrong)`)},
 	{pattern: regexp.MustCompile(`FAILED unresolved symbol`)},
 	{pattern: regexp.MustCompile(`No rule to make target`)},
+	{pattern: regexp.MustCompile(`^Killed$`)},
 	{weak: true, pattern: regexp.MustCompile(`: not found`)},
 	{weak: true, pattern: regexp.MustCompile(`: final link failed: `)},
 	{weak: true, pattern: regexp.MustCompile(`collect2: error: `)},
diff --git a/pkg/build/build_test.go b/pkg/build/build_test.go
index c89f63151..6aa9d9216 100644
--- a/pkg/build/build_test.go
+++ b/pkg/build/build_test.go
@@ -8,6 +8,10 @@ import (
 	"os/exec"
 	"strings"
 	"testing"
+
+	"github.com/google/syzkaller/pkg/osutil"
+	"github.com/google/syzkaller/sys/targets"
+	"github.com/stretchr/testify/assert"
 )
 
 func TestCompilerIdentity(t *testing.T) {
@@ -36,7 +40,7 @@ func TestCompilerIdentity(t *testing.T) {
 	}
 }
 
-func TestExtractRootCause(t *testing.T) {
+func TestExtractCauseInner(t *testing.T) {
 	for i, test := range rootCauseTests {
 		test := test
 		t.Run(fmt.Sprint(i), func(t *testing.T) {
@@ -51,6 +55,36 @@ func TestExtractRootCause(t *testing.T) {
 	}
 }
 
+func TestExtractRootCause(t *testing.T) {
+	targetOs := targets.TestOS
+	for i, test := range rootCauseTests {
+		var expected error
+		err := &osutil.VerboseError{Output: []byte(test.e)}
+		if test.reason == "" {
+			continue
+		} else if test.reason == "Killed" {
+			err.ExitCode = 137
+			targetOs = targets.Linux
+			expected = &InfraError{
+				Title:  test.reason,
+				Output: err.Output,
+			}
+		} else {
+			expected = &KernelError{
+				Report:     []byte(test.reason),
+				Output:     err.Output,
+				guiltyFile: test.file,
+			}
+		}
+		t.Run(fmt.Sprint(i), func(t *testing.T) {
+			got := extractRootCause(err, targetOs, test.src)
+			if got != nil {
+				assert.Equal(t, expected, got)
+			}
+		})
+	}
+}
+
 type RootCauseTest struct {
 	e      string
 	reason string
@@ -546,4 +580,17 @@ ninja: build stopped: subcommand failed.
 		"",
 		"",
 	},
+	{`
+  AR      built-in.a
+  AR      vmlinux.a
+  LD      vmlinux.o
+Killed
+make[1]: *** [scripts/Makefile.vmlinux_o:61: vmlinux.o] Error 137
+make[1]: *** Deleting file 'vmlinux.o'
+make: *** [Makefile:1231: vmlinux_o] Error 2
+`,
+		"Killed",
+		"",
+		"",
+	},
 }