DockerCLI/vendor/golang.org/x/sys/unix/mremap.go

41 lines
1.1 KiB
Go

// Copyright 2023 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build linux
// +build linux
package unix
import "unsafe"
type mremapMmapper struct {
mmapper
mremap func(oldaddr uintptr, oldlength uintptr, newlength uintptr, flags int, newaddr uintptr) (xaddr uintptr, err error)
}
func (m *mremapMmapper) Mremap(oldData []byte, newLength int, flags int) (data []byte, err error) {
if newLength <= 0 || len(oldData) == 0 || len(oldData) != cap(oldData) || flags&MREMAP_FIXED != 0 {
return nil, EINVAL
}
pOld := &oldData[cap(oldData)-1]
m.Lock()
defer m.Unlock()
bOld := m.active[pOld]
if bOld == nil || &bOld[0] != &oldData[0] {
return nil, EINVAL
}
newAddr, errno := m.mremap(uintptr(unsafe.Pointer(&bOld[0])), uintptr(len(bOld)), uintptr(newLength), flags, 0)
if errno != nil {
return nil, errno
}
bNew := unsafe.Slice((*byte)(unsafe.Pointer(newAddr)), newLength)
pNew := &bNew[cap(bNew)-1]
if flags&MREMAP_DONTUNMAP == 0 {
delete(m.active, pOld)
}
m.active[pNew] = bNew
return bNew, nil
}