github.com/MerlinKodo/gvisor@v0.0.0-20231110090155-957f62ecf90e/pkg/fsutil/fsutil_arm64_unsafe.go (about)

     1  // Copyright 2019 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  //go:build arm64
    16  // +build arm64
    17  
    18  package fsutil
    19  
    20  import (
    21  	"unsafe"
    22  
    23  	"golang.org/x/sys/unix"
    24  	"github.com/MerlinKodo/gvisor/pkg/syserr"
    25  )
    26  
    27  // StatAt is a convenience wrapper around fstatat(2).
    28  func StatAt(dirFd int, name string) (unix.Stat_t, error) {
    29  	nameBytes, err := unix.BytePtrFromString(name)
    30  	if err != nil {
    31  		return unix.Stat_t{}, err
    32  	}
    33  	namePtr := unsafe.Pointer(nameBytes)
    34  
    35  	var stat unix.Stat_t
    36  	statPtr := unsafe.Pointer(&stat)
    37  
    38  	if _, _, errno := unix.Syscall6(
    39  		unix.SYS_FSTATAT,
    40  		uintptr(dirFd),
    41  		uintptr(namePtr),
    42  		uintptr(statPtr),
    43  		unix.AT_SYMLINK_NOFOLLOW,
    44  		0,
    45  		0); errno != 0 {
    46  
    47  		return unix.Stat_t{}, syserr.FromHost(errno).ToError()
    48  	}
    49  	return stat, nil
    50  }