host: add kallsyms parsing tests

Start with a few simple tests that can be extended when needed.

2 files changed, 88 insertions, 18 deletions

diff --git a/pkg/host/host_linux.go b/pkg/host/host_linux.go
index ca98d927b..ae8d7af85 100644
--- a/pkg/host/host_linux.go
+++ b/pkg/host/host_linux.go
@@ -67,23 +67,7 @@ func isSupported(c *prog.Syscall, target *prog.Target, sandbox string) (bool, st
 		if len(kallsyms) == 0 {
 			return
 		}
-		var re *regexp.Regexp
-		switch target.Arch {
-		case "386", "amd64":
-			re = regexp.MustCompile(` T (__ia32_|__x64_)?sys_([^\n]+)\n`)
-		case "arm64":
-			re = regexp.MustCompile(` T (__arm64_)?sys_([^\n]+)\n`)
-		case "ppc64le":
-			re = regexp.MustCompile(` T ()?sys_([^\n]+)\n`)
-		default:
-			panic("unsupported arch for kallsyms parsing")
-		}
-		matches := re.FindAllSubmatch(kallsyms, -1)
-		for _, m := range matches {
-			name := string(m[2])
-			log.Logf(2, "found in kallsyms: %v", name)
-			kallsymsSyscallSet[name] = true
-		}
+		kallsymsSyscallSet = parseKallsyms(kallsyms, target.Arch)
 	})
 	if !testFallback && len(kallsymsSyscallSet) != 0 {
 		r, v := isSupportedKallsyms(c)
@@ -92,6 +76,28 @@ func isSupported(c *prog.Syscall, target *prog.Target, sandbox string) (bool, st
 	return isSupportedTrial(c)
 }
 
+func parseKallsyms(kallsyms []byte, arch string) map[string]bool {
+	set := make(map[string]bool)
+	var re *regexp.Regexp
+	switch arch {
+	case "386", "amd64":
+		re = regexp.MustCompile(` T (__ia32_|__x64_)?sys_([^\n]+)\n`)
+	case "arm64":
+		re = regexp.MustCompile(` T (__arm64_)?sys_([^\n]+)\n`)
+	case "ppc64le":
+		re = regexp.MustCompile(` T ()?sys_([^\n]+)\n`)
+	default:
+		panic("unsupported arch for kallsyms parsing")
+	}
+	matches := re.FindAllSubmatch(kallsyms, -1)
+	for _, m := range matches {
+		name := string(m[2])
+		log.Logf(2, "found in kallsyms: %v", name)
+		set[name] = true
+	}
+	return set
+}
+
 func isSupportedKallsyms(c *prog.Syscall) (bool, string) {
 	name := c.CallName
 	if newname := kallsymsRenameMap[name]; newname != "" {
@@ -144,7 +150,7 @@ func init() {
 // Where umount is renamed to oldumount is unclear.
 var (
 	kallsymsOnce       sync.Once
-	kallsymsSyscallSet = make(map[string]bool)
+	kallsymsSyscallSet map[string]bool
 	kallsymsRenameMap  = map[string]string{
 		"umount":  "oldumount",
 		"umount2": "umount",
diff --git a/pkg/host/host_test.go b/pkg/host/host_test.go
index c8190dac5..43e063eaf 100644
--- a/pkg/host/host_test.go
+++ b/pkg/host/host_test.go
@@ -46,6 +46,70 @@ func TestDetectSupportedSyscalls(t *testing.T) {
 	}
 }
 
+func TestKallsymsParse(t *testing.T) {
+	tests := []struct {
+		Arch     string
+		Kallsyms []byte
+		Syscalls []string
+	}{
+		{
+			"amd64",
+			[]byte(`
+ffffffff817cdcc0 T __sys_bind
+ffffffff817cdda0 T __x64_sys_bind
+ffffffff817cddc0 T __ia32_sys_bind
+ffffffff817cdde0 T __sys_listen
+ffffffff817cde80 T __x64_sys_listen
+ffffffff817cde90 T __ia32_sys_listen
+ffffffff817cdea0 T __sys_accept4
+ffffffff817ce080 T __x64_sys_accept4
+ffffffff817ce0a0 T __ia32_sys_accept4
+			`),
+			[]string{"bind", "listen", "accept4"},
+		},
+		{
+			"arm64",
+			[]byte(`
+ffff000010a3ddf8 T __sys_bind
+ffff000010a3def8 T __arm64_sys_bind
+ffff000010a3df20 T __sys_listen
+ffff000010a3dfd8 T __arm64_sys_listen
+ffff000010a3e000 T __sys_accept4
+ffff000010a3e1f0 T __arm64_sys_accept4
+			`),
+			[]string{"bind", "listen", "accept4"},
+		},
+		{
+			"ppc64le",
+			[]byte(`
+c0000000011ec810 T __sys_bind
+c0000000011eca10 T sys_bind
+c0000000011eca10 T __se_sys_bind
+c0000000011eca70 T __sys_listen
+c0000000011ecc10 T sys_listen
+c0000000011ecc10 T __se_sys_listen
+c0000000011ecc70 T __sys_accept4
+c0000000011ed050 T sys_accept4
+c0000000011ed050 T __se_sys_accept4
+			`),
+			[]string{"bind", "listen", "accept4"},
+		},
+	}
+
+	for _, test := range tests {
+		syscallSet := parseKallsyms(test.Kallsyms, test.Arch)
+		if len(syscallSet) != len(test.Syscalls) {
+			t.Fatalf("wrong number of parse syscalls, expected: %v, got: %v",
+				len(test.Syscalls), len(syscallSet))
+		}
+		for _, syscall := range test.Syscalls {
+			if _, ok := syscallSet[syscall]; !ok {
+				t.Fatalf("syscall %v not found in parsed syscall list", syscall)
+			}
+		}
+	}
+}
+
 func TestCheck(t *testing.T) {
 	t.Parallel()
 	target, err := prog.GetTarget(runtime.GOOS, runtime.GOARCH)