| // Copyright 2009 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 aix || darwin || dragonfly || freebsd || hurd || linux || netbsd || openbsd || solaris |
| |
| package syscall |
| |
| import ( |
| "internal/race" |
| "internal/unsafeheader" |
| "runtime" |
| "sync" |
| "unsafe" |
| ) |
| |
| var ( |
| Stdin = 0 |
| Stdout = 1 |
| Stderr = 2 |
| ) |
| |
| const ( |
| darwin64Bit = (runtime.GOOS == "darwin" || runtime.GOOS == "ios") && sizeofPtr == 8 |
| netbsd32Bit = runtime.GOOS == "netbsd" && sizeofPtr == 4 |
| ) |
| |
| // clen returns the index of the first NULL byte in n or len(n) if n contains no NULL byte. |
| func clen(n []byte) int { |
| for i := 0; i < len(n); i++ { |
| if n[i] == 0 { |
| return i |
| } |
| } |
| return len(n) |
| } |
| |
| // Mmap manager, for use by operating system-specific implementations. |
| // Gccgo only has one implementation but we do this to correspond to gc. |
| |
| type mmapper struct { |
| sync.Mutex |
| active map[*byte][]byte // active mappings; key is last byte in mapping |
| mmap func(addr, length uintptr, prot, flags, fd int, offset int64) (uintptr, error) |
| munmap func(addr uintptr, length uintptr) error |
| } |
| |
| func (m *mmapper) Mmap(fd int, offset int64, length int, prot int, flags int) (data []byte, err error) { |
| if length <= 0 { |
| return nil, EINVAL |
| } |
| |
| // Map the requested memory. |
| addr, errno := m.mmap(0, uintptr(length), prot, flags, fd, offset) |
| if errno != nil { |
| return nil, errno |
| } |
| |
| // Use unsafe to turn addr into a []byte. |
| var b []byte |
| hdr := (*unsafeheader.Slice)(unsafe.Pointer(&b)) |
| hdr.Data = unsafe.Pointer(addr) |
| hdr.Cap = length |
| hdr.Len = length |
| |
| // Register mapping in m and return it. |
| p := &b[cap(b)-1] |
| m.Lock() |
| defer m.Unlock() |
| m.active[p] = b |
| return b, nil |
| } |
| |
| func (m *mmapper) Munmap(data []byte) (err error) { |
| if len(data) == 0 || len(data) != cap(data) { |
| return EINVAL |
| } |
| |
| // Find the base of the mapping. |
| p := &data[cap(data)-1] |
| m.Lock() |
| defer m.Unlock() |
| b := m.active[p] |
| if b == nil || &b[0] != &data[0] { |
| return EINVAL |
| } |
| |
| // Unmap the memory and update m. |
| if errno := m.munmap(uintptr(unsafe.Pointer(&b[0])), uintptr(len(b))); errno != nil { |
| return errno |
| } |
| delete(m.active, p) |
| return nil |
| } |
| |
| var mapper = &mmapper{ |
| active: make(map[*byte][]byte), |
| mmap: mmap, |
| munmap: munmap, |
| } |
| |
| func Mmap(fd int, offset int64, length int, prot int, flags int) (data []byte, err error) { |
| return mapper.Mmap(fd, offset, length, prot, flags) |
| } |
| |
| func Munmap(b []byte) (err error) { |
| return mapper.Munmap(b) |
| } |
| |
| // Do the interface allocations only once for common |
| // Errno values. |
| var ( |
| errEAGAIN error = EAGAIN |
| errEINVAL error = EINVAL |
| errENOENT error = ENOENT |
| ) |
| |
| // errnoErr returns common boxed Errno values, to prevent |
| // allocations at runtime. |
| func errnoErr(e Errno) error { |
| switch e { |
| case 0: |
| return nil |
| case EAGAIN: |
| return errEAGAIN |
| case EINVAL: |
| return errEINVAL |
| case ENOENT: |
| return errENOENT |
| } |
| return e |
| } |
| |
| // A Signal is a number describing a process signal. |
| // It implements the os.Signal interface. |
| type Signal int |
| |
| func (s Signal) Signal() {} |
| |
| func Signame(s Signal) string |
| |
| func (s Signal) String() string { |
| return Signame(s) |
| } |
| |
| func Read(fd int, p []byte) (n int, err error) { |
| n, err = read(fd, p) |
| if race.Enabled { |
| if n > 0 { |
| race.WriteRange(unsafe.Pointer(&p[0]), n) |
| } |
| if err == nil { |
| race.Acquire(unsafe.Pointer(&ioSync)) |
| } |
| } |
| if msanenabled && n > 0 { |
| msanWrite(unsafe.Pointer(&p[0]), n) |
| } |
| if asanenabled && n > 0 { |
| asanWrite(unsafe.Pointer(&p[0]), n) |
| } |
| return |
| } |
| |
| func Write(fd int, p []byte) (n int, err error) { |
| if race.Enabled { |
| race.ReleaseMerge(unsafe.Pointer(&ioSync)) |
| } |
| if faketime && (fd == 1 || fd == 2) { |
| n = faketimeWrite(fd, p) |
| if n < 0 { |
| n, err = 0, errnoErr(Errno(-n)) |
| } |
| } else { |
| n, err = write(fd, p) |
| } |
| if race.Enabled && n > 0 { |
| race.ReadRange(unsafe.Pointer(&p[0]), n) |
| } |
| if msanenabled && n > 0 { |
| msanRead(unsafe.Pointer(&p[0]), n) |
| } |
| if asanenabled && n > 0 { |
| asanRead(unsafe.Pointer(&p[0]), n) |
| } |
| return |
| } |
| |
| var ioSync int64 |