| // 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 |
| } |