github.com/MerlinKodo/gvisor@v0.0.0-20231110090155-957f62ecf90e/pkg/sentry/mm/save_restore.go (about)

     1  // Copyright 2018 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package mm
    16  
    17  import (
    18  	"fmt"
    19  
    20  	"github.com/MerlinKodo/gvisor/pkg/context"
    21  )
    22  
    23  // InvalidateUnsavable invokes memmap.Mappable.InvalidateUnsavable on all
    24  // Mappables mapped by mm.
    25  func (mm *MemoryManager) InvalidateUnsavable(ctx context.Context) error {
    26  	mm.mappingMu.RLock()
    27  	defer mm.mappingMu.RUnlock()
    28  	for vseg := mm.vmas.FirstSegment(); vseg.Ok(); vseg = vseg.NextSegment() {
    29  		if vma := vseg.ValuePtr(); vma.mappable != nil {
    30  			if err := vma.mappable.InvalidateUnsavable(ctx); err != nil {
    31  				return err
    32  			}
    33  		}
    34  	}
    35  	return nil
    36  }
    37  
    38  // beforeSave is invoked by stateify.
    39  func (mm *MemoryManager) beforeSave() {
    40  	mf := mm.mfp.MemoryFile()
    41  	for pseg := mm.pmas.FirstSegment(); pseg.Ok(); pseg = pseg.NextSegment() {
    42  		if pma := pseg.ValuePtr(); pma.file != mf {
    43  			// InvalidateUnsavable should have caused all such pmas to be
    44  			// invalidated.
    45  			panic(fmt.Sprintf("Can't save pma %#v with non-MemoryFile of type %T:\n%s", pseg.Range(), pma.file, mm))
    46  		}
    47  	}
    48  }
    49  
    50  // afterLoad is invoked by stateify.
    51  func (mm *MemoryManager) afterLoad() {
    52  	mm.haveASIO = mm.p.SupportsAddressSpaceIO()
    53  	mf := mm.mfp.MemoryFile()
    54  	for pseg := mm.pmas.FirstSegment(); pseg.Ok(); pseg = pseg.NextSegment() {
    55  		pseg.ValuePtr().file = mf
    56  	}
    57  }