github.com/SagerNet/gvisor@v0.0.0-20210707092255-7731c139d75c/pkg/memutil/mmap.go (about)

     1  // Copyright 2020 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 memutil
    16  
    17  import (
    18  	"golang.org/x/sys/unix"
    19  )
    20  
    21  // MapFile returns a memory mapping configured by the given options as per
    22  // mmap(2).
    23  func MapFile(addr, len, prot, flags, fd, offset uintptr) (uintptr, error) {
    24  	m, _, e := unix.RawSyscall6(unix.SYS_MMAP, addr, len, prot, flags, fd, offset)
    25  	if e != 0 {
    26  		return 0, e
    27  	}
    28  	return m, nil
    29  }