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// Copyright 2018 The gVisor Authors.
//
// 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 mm
import (
"testing"
"gvisor.googlesource.com/gvisor/pkg/sentry/arch"
"gvisor.googlesource.com/gvisor/pkg/sentry/context"
"gvisor.googlesource.com/gvisor/pkg/sentry/context/contexttest"
"gvisor.googlesource.com/gvisor/pkg/sentry/limits"
"gvisor.googlesource.com/gvisor/pkg/sentry/memmap"
"gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc"
"gvisor.googlesource.com/gvisor/pkg/sentry/platform"
"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
"gvisor.googlesource.com/gvisor/pkg/syserror"
)
func testMemoryManager(ctx context.Context) *MemoryManager {
p := platform.FromContext(ctx)
mfp := pgalloc.MemoryFileProviderFromContext(ctx)
mm := NewMemoryManager(p, mfp)
mm.layout = arch.MmapLayout{
MinAddr: p.MinUserAddress(),
MaxAddr: p.MaxUserAddress(),
BottomUpBase: p.MinUserAddress(),
TopDownBase: p.MaxUserAddress(),
}
return mm
}
func (mm *MemoryManager) realUsageAS() uint64 {
return uint64(mm.vmas.Span())
}
func TestUsageASUpdates(t *testing.T) {
ctx := contexttest.Context(t)
mm := testMemoryManager(ctx)
defer mm.DecUsers(ctx)
addr, err := mm.MMap(ctx, memmap.MMapOpts{
Length: 2 * usermem.PageSize,
})
if err != nil {
t.Fatalf("MMap got err %v want nil", err)
}
realUsage := mm.realUsageAS()
if mm.usageAS != realUsage {
t.Fatalf("usageAS believes %v bytes are mapped; %v bytes are actually mapped", mm.usageAS, realUsage)
}
mm.MUnmap(ctx, addr, usermem.PageSize)
realUsage = mm.realUsageAS()
if mm.usageAS != realUsage {
t.Fatalf("usageAS believes %v bytes are mapped; %v bytes are actually mapped", mm.usageAS, realUsage)
}
}
func TestBrkDataLimitUpdates(t *testing.T) {
limitSet := limits.NewLimitSet()
limitSet.Set(limits.Data, limits.Limit{}, true /* privileged */) // zero RLIMIT_DATA
ctx := contexttest.WithLimitSet(contexttest.Context(t), limitSet)
mm := testMemoryManager(ctx)
defer mm.DecUsers(ctx)
// Try to extend the brk by one page and expect doing so to fail.
oldBrk, _ := mm.Brk(ctx, 0)
if newBrk, _ := mm.Brk(ctx, oldBrk+usermem.PageSize); newBrk != oldBrk {
t.Errorf("brk() increased data segment above RLIMIT_DATA (old brk = %#x, new brk = %#x", oldBrk, newBrk)
}
}
// TestIOAfterUnmap ensures that IO fails after unmap.
func TestIOAfterUnmap(t *testing.T) {
ctx := contexttest.Context(t)
mm := testMemoryManager(ctx)
defer mm.DecUsers(ctx)
addr, err := mm.MMap(ctx, memmap.MMapOpts{
Length: usermem.PageSize,
Private: true,
Perms: usermem.Read,
MaxPerms: usermem.AnyAccess,
})
if err != nil {
t.Fatalf("MMap got err %v want nil", err)
}
// IO works before munmap.
b := make([]byte, 1)
n, err := mm.CopyIn(ctx, addr, b, usermem.IOOpts{})
if err != nil {
t.Errorf("CopyIn got err %v want nil", err)
}
if n != 1 {
t.Errorf("CopyIn got %d want 1", n)
}
err = mm.MUnmap(ctx, addr, usermem.PageSize)
if err != nil {
t.Fatalf("MUnmap got err %v want nil", err)
}
n, err = mm.CopyIn(ctx, addr, b, usermem.IOOpts{})
if err != syserror.EFAULT {
t.Errorf("CopyIn got err %v want EFAULT", err)
}
if n != 0 {
t.Errorf("CopyIn got %d want 0", n)
}
}
// TestIOAfterMProtect tests IO interaction with mprotect permissions.
func TestIOAfterMProtect(t *testing.T) {
ctx := contexttest.Context(t)
mm := testMemoryManager(ctx)
defer mm.DecUsers(ctx)
addr, err := mm.MMap(ctx, memmap.MMapOpts{
Length: usermem.PageSize,
Private: true,
Perms: usermem.ReadWrite,
MaxPerms: usermem.AnyAccess,
})
if err != nil {
t.Fatalf("MMap got err %v want nil", err)
}
// Writing works before mprotect.
b := make([]byte, 1)
n, err := mm.CopyOut(ctx, addr, b, usermem.IOOpts{})
if err != nil {
t.Errorf("CopyOut got err %v want nil", err)
}
if n != 1 {
t.Errorf("CopyOut got %d want 1", n)
}
err = mm.MProtect(addr, usermem.PageSize, usermem.Read, false)
if err != nil {
t.Errorf("MProtect got err %v want nil", err)
}
// Without IgnorePermissions, CopyOut should no longer succeed.
n, err = mm.CopyOut(ctx, addr, b, usermem.IOOpts{})
if err != syserror.EFAULT {
t.Errorf("CopyOut got err %v want EFAULT", err)
}
if n != 0 {
t.Errorf("CopyOut got %d want 0", n)
}
// With IgnorePermissions, CopyOut should succeed despite mprotect.
n, err = mm.CopyOut(ctx, addr, b, usermem.IOOpts{
IgnorePermissions: true,
})
if err != nil {
t.Errorf("CopyOut got err %v want nil", err)
}
if n != 1 {
t.Errorf("CopyOut got %d want 1", n)
}
}
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