1 files changed, 161 insertions, 0 deletions
diff --git a/pkg/sentry/platform/ring0/pagetables/pagetables_test.go b/pkg/sentry/platform/ring0/pagetables/pagetables_test.go
new file mode 100644
index 000000000..9cbc0e3b0
--- /dev/null
+++ b/pkg/sentry/platform/ring0/pagetables/pagetables_test.go
@@ -0,0 +1,161 @@
+// Copyright 2018 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pagetables
+
+import (
+	"reflect"
+	"testing"
+
+	"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
+)
+
+type reflectTranslater struct{}
+
+func (r reflectTranslater) TranslateToPhysical(ptes *PTEs) uintptr {
+	return reflect.ValueOf(ptes).Pointer()
+}
+
+type mapping struct {
+	start     uintptr
+	length    uintptr
+	addr      uintptr
+	writeable bool
+}
+
+func checkMappings(t *testing.T, pt *PageTables, m []mapping) {
+	var (
+		current int
+		found   []mapping
+		failed  string
+	)
+
+	// Iterate over all the mappings.
+	pt.iterateRange(0, ^uintptr(0), false, func(s, e uintptr, pte *PTE, align uintptr) {
+		found = append(found, mapping{
+			start:     s,
+			length:    e - s,
+			addr:      pte.Address(),
+			writeable: pte.Writeable(),
+		})
+		if failed != "" {
+			// Don't keep looking for errors.
+			return
+		}
+
+		if current >= len(m) {
+			failed = "more mappings than expected"
+		} else if m[current].start != s {
+			failed = "start didn't match expected"
+		} else if m[current].length != (e - s) {
+			failed = "end didn't match expected"
+		} else if m[current].addr != pte.Address() {
+			failed = "address didn't match expected"
+		} else if m[current].writeable != pte.Writeable() {
+			failed = "writeable didn't match"
+		}
+		current++
+	})
+
+	// Were we expected additional mappings?
+	if failed == "" && current != len(m) {
+		failed = "insufficient mappings found"
+	}
+
+	// Emit a meaningful error message on failure.
+	if failed != "" {
+		t.Errorf("%s; got %#v, wanted %#v", failed, found, m)
+	}
+}
+
+func TestAllocFree(t *testing.T) {
+	pt := New(reflectTranslater{}, Opts{})
+	pt.Release()
+}
+
+func TestUnmap(t *testing.T) {
+	pt := New(reflectTranslater{}, Opts{})
+
+	// Map and unmap one entry.
+	pt.Map(0x400000, pteSize, true, usermem.ReadWrite, pteSize*42)
+	pt.Unmap(0x400000, pteSize)
+
+	checkMappings(t, pt, nil)
+	pt.Release()
+}
+
+func TestReadOnly(t *testing.T) {
+	pt := New(reflectTranslater{}, Opts{})
+
+	// Map one entry.
+	pt.Map(0x400000, pteSize, true, usermem.Read, pteSize*42)
+
+	checkMappings(t, pt, []mapping{
+		{0x400000, pteSize, pteSize * 42, false},
+	})
+	pt.Release()
+}
+
+func TestReadWrite(t *testing.T) {
+	pt := New(reflectTranslater{}, Opts{})
+
+	// Map one entry.
+	pt.Map(0x400000, pteSize, true, usermem.ReadWrite, pteSize*42)
+
+	checkMappings(t, pt, []mapping{
+		{0x400000, pteSize, pteSize * 42, true},
+	})
+	pt.Release()
+}
+
+func TestSerialEntries(t *testing.T) {
+	pt := New(reflectTranslater{}, Opts{})
+
+	// Map two sequential entries.
+	pt.Map(0x400000, pteSize, true, usermem.ReadWrite, pteSize*42)
+	pt.Map(0x401000, pteSize, true, usermem.ReadWrite, pteSize*47)
+
+	checkMappings(t, pt, []mapping{
+		{0x400000, pteSize, pteSize * 42, true},
+		{0x401000, pteSize, pteSize * 47, true},
+	})
+	pt.Release()
+}
+
+func TestSpanningEntries(t *testing.T) {
+	pt := New(reflectTranslater{}, Opts{})
+
+	// Span a pgd with two pages.
+	pt.Map(0x00007efffffff000, 2*pteSize, true, usermem.Read, pteSize*42)
+
+	checkMappings(t, pt, []mapping{
+		{0x00007efffffff000, pteSize, pteSize * 42, false},
+		{0x00007f0000000000, pteSize, pteSize * 43, false},
+	})
+	pt.Release()
+}
+
+func TestSparseEntries(t *testing.T) {
+	pt := New(reflectTranslater{}, Opts{})
+
+	// Map two entries in different pgds.
+	pt.Map(0x400000, pteSize, true, usermem.ReadWrite, pteSize*42)
+	pt.Map(0x00007f0000000000, pteSize, true, usermem.Read, pteSize*47)
+
+	checkMappings(t, pt, []mapping{
+		{0x400000, pteSize, pteSize * 42, true},
+		{0x00007f0000000000, pteSize, pteSize * 47, false},
+	})
+	pt.Release()
+}