syz-verifier/verf: add the first version of the Verifier

This checks whether the errno returned by a program's system call executed by different Runners are the same.

2 files changed, 131 insertions, 0 deletions

diff --git a/syz-verifier/verf/verifier.go b/syz-verifier/verf/verifier.go
new file mode 100644
index 000000000..2678af23b
--- /dev/null
+++ b/syz-verifier/verf/verifier.go
@@ -0,0 +1,45 @@
+// 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 verf contains utilities for verifying the execution of the same
+// program on different kernels yield the same results.
+package verf
+
+import (
+	"github.com/google/syzkaller/pkg/ipc"
+	"github.com/google/syzkaller/prog"
+)
+
+// Result stores the results of executing a program.
+type Result struct {
+	// Pool is the index of the pool.
+	Pool int
+	// Hanged is set to true when a program was killed due to hanging.
+	Hanged bool
+	// Info contains information about the execution of each system call
+	// in the generated programs.
+	Info ipc.ProgInfo
+}
+
+// Verify checks whether the Results of the same program, executed on different
+// kernels are the same. If that's the case, it returns true, otherwise it
+// returns false.
+func Verify(res []*Result, prog *prog.Prog) bool {
+	for i := 1; i < len(res); i++ {
+		if !VerifyErrnos(res[0].Info.Calls, res[i].Info.Calls) {
+			return false
+		}
+	}
+	return true
+}
+
+// VerifyErrnos checks whether the returned system call errnos of the same
+// program, executed on two different kernels, are the same.
+func VerifyErrnos(c1, c2 []ipc.CallInfo) bool {
+	for idx, c := range c1 {
+		if c.Errno != c2[idx].Errno {
+			return false
+		}
+	}
+	return true
+}
diff --git a/syz-verifier/verf/verifier_test.go b/syz-verifier/verf/verifier_test.go
new file mode 100644
index 000000000..c9a25acb5
--- /dev/null
+++ b/syz-verifier/verf/verifier_test.go
@@ -0,0 +1,86 @@
+// 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 verf
+
+import (
+	"testing"
+
+	"github.com/google/syzkaller/pkg/ipc"
+)
+
+func TestVerify(t *testing.T) {
+	tests := []struct {
+		name      string
+		res       []*Result
+		wantMatch bool
+	}{
+		{
+
+			name: "results should match",
+			res: []*Result{
+				{2, false, ipc.ProgInfo{
+					Calls: []ipc.CallInfo{{Errno: 1}, {Errno: 2}, {Errno: 3}}, Extra: ipc.CallInfo{},
+				},
+				},
+				{4, false, ipc.ProgInfo{
+					Calls: []ipc.CallInfo{{Errno: 1}, {Errno: 2}, {Errno: 3}},
+					Extra: ipc.CallInfo{},
+				},
+				},
+			},
+
+			wantMatch: true,
+		},
+		{
+			name: "results should not match",
+			res: []*Result{
+				{4, false, ipc.ProgInfo{
+					Calls: []ipc.CallInfo{{Errno: 1}, {Errno: 2}, {Errno: 5}},
+				},
+				},
+				{8, false, ipc.ProgInfo{
+					Calls: []ipc.CallInfo{{Errno: 1}, {Errno: 3}, {Errno: 5}},
+				},
+				},
+			},
+			wantMatch: false,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			if got, want := Verify(test.res, nil), test.wantMatch; got != want {
+				t.Errorf("Verify: got %v, want %v", got, want)
+			}
+		})
+	}
+}
+
+func TestVerifyErrno(t *testing.T) {
+	tests := []struct {
+		name      string
+		c1, c2    []ipc.CallInfo
+		wantMatch bool
+	}{
+		{
+			name:      "errno should match",
+			c1:        []ipc.CallInfo{{Errno: 1}, {Errno: 2}, {Errno: 5}},
+			c2:        []ipc.CallInfo{{Errno: 1}, {Errno: 2}, {Errno: 5}},
+			wantMatch: true,
+		},
+		{
+			name:      "errno should not match",
+			c1:        []ipc.CallInfo{{Errno: 1}, {Errno: 2}, {Errno: 5}},
+			c2:        []ipc.CallInfo{{Errno: 1}, {Errno: 4}, {Errno: 5}},
+			wantMatch: false,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			if got, want := VerifyErrnos(test.c1, test.c2), test.wantMatch; got != want {
+				t.Errorf("VerifyErrno: got %v, want %v", got, want)
+			}
+		})
+	}
+}