pkg/host: use unix.Utsname instead of syscall.Utsname

syscall.Utsname is hard to use portably, see:
https://github.com/google/syzkaller/pull/2418#issuecomment-774858512
Switch to unix.Utsname which does not have this problem.

2 files changed, 29 insertions, 11 deletions

diff --git a/pkg/host/features_linux.go b/pkg/host/features_linux.go
index ab8c2fc48..fc925c00c 100644
--- a/pkg/host/features_linux.go
+++ b/pkg/host/features_linux.go
@@ -14,6 +14,7 @@ import (
 	"github.com/google/syzkaller/pkg/osutil"
 	"github.com/google/syzkaller/prog"
 	"github.com/google/syzkaller/sys/linux"
+	"golang.org/x/sys/unix"
 )
 
 func init() {
@@ -233,21 +234,15 @@ func checkWifiEmulation() string {
 }
 
 func requireKernel(x, y int) string {
-	info := new(syscall.Utsname)
-	if err := syscall.Uname(info); err != nil {
+	info := new(unix.Utsname)
+	if err := unix.Uname(info); err != nil {
 		return fmt.Sprintf("uname failed: %v", err)
 	}
-	var ver []byte
-	for _, b := range info.Release {
-		if b == 0 {
-			break
-		}
-		ver = append(ver, byte(b))
-	}
-	if ok, bad := matchKernelVersion(string(ver), x, y); bad {
+	ver := string(info.Release[:])
+	if ok, bad := matchKernelVersion(ver, x, y); bad {
 		return fmt.Sprintf("failed to parse kernel version (%v)", ver)
 	} else if !ok {
-		return fmt.Sprintf("kernel %v.%v required (have %s)", x, y, ver)
+		return fmt.Sprintf("kernel %v.%v required (have %v)", x, y, ver)
 	}
 	return ""
 }
diff --git a/pkg/host/features_linux_test.go b/pkg/host/features_linux_test.go
new file mode 100644
index 000000000..35d6197c1
--- /dev/null
+++ b/pkg/host/features_linux_test.go
@@ -0,0 +1,23 @@
+// Copyright 2021 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 host
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestRequireKernel(t *testing.T) {
+	if what := requireKernel(2, 999); what != "" {
+		t.Fatalf("requireKernel(2, 999) failed: %v", what)
+	}
+	if what := requireKernel(3, 0); what != "" {
+		t.Fatalf("requireKernel(3, 0) failed: %v", what)
+	}
+	if what := requireKernel(99, 1); what == "" {
+		t.Fatalf("requireKernel(99, 1) succeeded")
+	} else if !strings.HasPrefix(what, "kernel 99.1 required") {
+		t.Fatalf("requireKernel(99, 1) failed: %v", what)
+	}
+}