syscall: add utimensat and use it for UtimesNano on BSD and Solaris

All the BSDs and Solaris support the utimensat syscall, but Darwin
doesn't. Account for that by adding the //sys lines not to
syscall_bsd.go but the individual OS's syscall_*.go files and implement
utimensat on Darwin as just returning ENOSYS, such that UtimesNano will
fall back to use utimes as it currently does unconditionally.

This also adds the previously missing utimensat syscall number for
FreeBSD and Dragonfly.

Fixes #16480

Change-Id: I367454c6168eb1f7150b988fa16cf02abff42f34
Reviewed-on: https://go-review.googlesource.com/55130Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>

src/syscall/syscall_bsd.go

@@ -507,11 +507,13 @@ func Utimes(path string, tv []Timeval) (err error) {
 }
 
 func UtimesNano(path string, ts []Timespec) error {
-	// TODO: The BSDs can do utimensat with SYS_UTIMENSAT but it
-	// isn't supported by darwin so this uses utimes instead
 	if len(ts) != 2 {
 		return EINVAL
 	}
+	err := utimensat(_AT_FDCWD, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])))
+	if err != ENOSYS {
+		return err
+	}
 	// Not as efficient as it could be because Timespec and
 	// Timeval have different types in the different OSes
 	tv := [2]Timeval{

src/syscall/syscall_darwin.go

@@ -186,6 +186,11 @@ func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
 	return
 }
 
+func utimensat(dirfd int, path string, times *[2]Timespec) error {
+	// Darwin doesn't support SYS_UTIMENSAT
+	return ENOSYS
+}
+
 /*
  * Wrapped
  */

src/syscall/syscall_dragonfly.go

@@ -211,6 +211,7 @@ func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
 //sys	readlen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_READ
 //sys	writelen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_WRITE
 //sys	accept4(fd int, rsa *RawSockaddrAny, addrlen *_Socklen, flags int) (nfd int, err error)
+//sys	utimensat(dirfd int, path string, times *[2]Timespec) (err error)
 
 /*
  * Unimplemented

src/syscall/syscall_freebsd.go

@@ -222,6 +222,7 @@ func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
 //sys	readlen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_READ
 //sys	writelen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_WRITE
 //sys	accept4(fd int, rsa *RawSockaddrAny, addrlen *_Socklen, flags int) (nfd int, err error)
+//sys	utimensat(dirfd int, path string, times *[2]Timespec) (err error)
 
 /*
  * Unimplemented

src/syscall/syscall_netbsd.go

@@ -202,6 +202,7 @@ func sendfile(outfd int, infd int, offset *int64, count int) (written int, err e
 //sys	munmap(addr uintptr, length uintptr) (err error)
 //sys	readlen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_READ
 //sys	writelen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_WRITE
+//sys	utimensat(dirfd int, path string, times *[2]Timespec) (err error)
 
 /*
  * Unimplemented

src/syscall/syscall_openbsd.go

@@ -183,6 +183,7 @@ func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
 //sys	munmap(addr uintptr, length uintptr) (err error)
 //sys	readlen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_READ
 //sys	writelen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_WRITE
+//sys	utimensat(dirfd int, path string, times *[2]Timespec) (err error)
 
 /*
  * Unimplemented
@@ -278,6 +279,5 @@ func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
 // thrsleep
 // thrwakeup
 // unlinkat
-// utimensat
 // vfork
 // writev

src/syscall/syscall_solaris.go

@@ -510,6 +510,7 @@ func SendmsgN(fd int, p, oob []byte, to Sockaddr, flags int) (n int, err error)
 //sys	recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, err error) = libsocket.recvfrom
 //sys	recvmsg(s int, msg *Msghdr, flags int) (n int, err error) = libsocket.__xnet_recvmsg
 //sys	getexecname() (path unsafe.Pointer, err error) = libc.getexecname
+//sys	utimensat(dirfd int, path string, times *[2]Timespec) (err error)
 
 func Getexecname() (path string, err error) {
 	ptr, err := getexecname()

src/syscall/types_darwin.go

@@ -238,6 +238,12 @@ type BpfInsn C.struct_bpf_insn
 
 type BpfHdr C.struct_bpf_hdr
 
+// Misc
+
+const (
+	_AT_FDCWD = C.AT_FDCWD
+)
+
 // Terminal handling
 
 type Termios C.struct_termios

src/syscall/types_dragonfly.go

@@ -237,6 +237,12 @@ type BpfInsn C.struct_bpf_insn
 
 type BpfHdr C.struct_bpf_hdr
 
+// Misc
+
+const (
+	_AT_FDCWD = C.AT_FDCWD
+)
+
 // Terminal handling
 
 type Termios C.struct_termios

src/syscall/types_freebsd.go

@@ -337,6 +337,12 @@ type BpfHdr C.struct_bpf_hdr
 
 type BpfZbufHeader C.struct_bpf_zbuf_header
 
+// Misc
+
+const (
+	_AT_FDCWD = C.AT_FDCWD
+)
+
 // Terminal handling
 
 type Termios C.struct_termios

src/syscall/types_netbsd.go

@@ -223,6 +223,12 @@ type BpfHdr C.struct_bpf_hdr
 
 type BpfTimeval C.struct_bpf_timeval
 
+// Misc
+
+const (
+	_AT_FDCWD = C.AT_FDCWD
+)
+
 // Terminal handling
 
 type Termios C.struct_termios

src/syscall/types_openbsd.go

@@ -239,6 +239,12 @@ type BpfHdr C.struct_bpf_hdr
 
 type BpfTimeval C.struct_bpf_timeval
 
+// Misc
+
+const (
+	_AT_FDCWD = C.AT_FDCWD
+)
+
 // Terminal handling
 
 type Termios C.struct_termios

src/syscall/types_solaris.go

@@ -224,6 +224,12 @@ type BpfTimeval C.struct_bpf_timeval
 
 type BpfHdr C.struct_bpf_hdr
 
+// Misc
+
+const (
+	_AT_FDCWD = C.AT_FDCWD
+)
+
 // Terminal handling
 
 type Termios C.struct_termios

src/syscall/zsyscall_dragonfly_amd64.go

@@ -1298,3 +1298,18 @@ func accept4(fd int, rsa *RawSockaddrAny, addrlen *_Socklen, flags int) (nfd int
 	}
 	return
 }
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func utimensat(dirfd int, path string, times *[2]Timespec) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall(SYS_UTIMENSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(times)))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}

src/syscall/zsyscall_freebsd_386.go

@@ -1308,3 +1308,18 @@ func accept4(fd int, rsa *RawSockaddrAny, addrlen *_Socklen, flags int) (nfd int
 	}
 	return
 }
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func utimensat(dirfd int, path string, times *[2]Timespec) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall(SYS_UTIMENSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(times)))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}

src/syscall/zsyscall_freebsd_amd64.go

@@ -1308,3 +1308,18 @@ func accept4(fd int, rsa *RawSockaddrAny, addrlen *_Socklen, flags int) (nfd int
 	}
 	return
 }
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func utimensat(dirfd int, path string, times *[2]Timespec) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall(SYS_UTIMENSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(times)))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}

src/syscall/zsyscall_freebsd_arm.go

@@ -1308,3 +1308,18 @@ func accept4(fd int, rsa *RawSockaddrAny, addrlen *_Socklen, flags int) (nfd int
 	}
 	return
 }
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func utimensat(dirfd int, path string, times *[2]Timespec) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall(SYS_UTIMENSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(times)))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}

src/syscall/zsyscall_netbsd_386.go

@@ -1224,3 +1224,18 @@ func writelen(fd int, buf *byte, nbuf int) (n int, err error) {
 	}
 	return
 }
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func utimensat(dirfd int, path string, times *[2]Timespec) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall(SYS_UTIMENSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(times)))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}

src/syscall/zsyscall_netbsd_amd64.go

@@ -1224,3 +1224,18 @@ func writelen(fd int, buf *byte, nbuf int) (n int, err error) {
 	}
 	return
 }
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func utimensat(dirfd int, path string, times *[2]Timespec) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall(SYS_UTIMENSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(times)))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}

src/syscall/zsyscall_netbsd_arm.go

-// mksyscall.pl -l32 -arm -tags netbsd,arm syscall_bsd.go syscall_netbsd.go syscall_netbsd_arm.go
+// mksyscall.pl -l32 -netbsd -arm -tags netbsd,arm syscall_bsd.go syscall_netbsd.go syscall_netbsd_arm.go
 // MACHINE GENERATED BY THE COMMAND ABOVE; DO NOT EDIT
 
 // +build netbsd,arm
@@ -1224,3 +1224,18 @@ func writelen(fd int, buf *byte, nbuf int) (n int, err error) {
 	}
 	return
 }
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func utimensat(dirfd int, path string, times *[2]Timespec) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall(SYS_UTIMENSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(times)))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}

src/syscall/zsyscall_openbsd_386.go

@@ -1262,3 +1262,18 @@ func writelen(fd int, buf *byte, nbuf int) (n int, err error) {
 	}
 	return
 }
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func utimensat(dirfd int, path string, times *[2]Timespec) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall(SYS_UTIMENSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(times)))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}

src/syscall/zsyscall_openbsd_amd64.go

@@ -1262,3 +1262,18 @@ func writelen(fd int, buf *byte, nbuf int) (n int, err error) {
 	}
 	return
 }
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func utimensat(dirfd int, path string, times *[2]Timespec) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall(SYS_UTIMENSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(times)))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}

src/syscall/zsyscall_openbsd_arm.go

@@ -1262,3 +1262,18 @@ func writelen(fd int, buf *byte, nbuf int) (n int, err error) {
 	}
 	return
 }
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func utimensat(dirfd int, path string, times *[2]Timespec) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall(SYS_UTIMENSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(times)))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}

src/syscall/zsyscall_solaris_amd64.go

@@ -90,6 +90,7 @@ import "unsafe"
 //go:cgo_import_dynamic libc_recvfrom recvfrom "libsocket.so"
 //go:cgo_import_dynamic libc___xnet_recvmsg __xnet_recvmsg "libsocket.so"
 //go:cgo_import_dynamic libc_getexecname getexecname "libc.so"
+//go:cgo_import_dynamic libc_utimensat utimensat "libc.so"
 
 //go:linkname libc_Getcwd libc_Getcwd
 //go:linkname libc_getgroups libc_getgroups
@@ -174,6 +175,7 @@ import "unsafe"
 //go:linkname libc_recvfrom libc_recvfrom
 //go:linkname libc___xnet_recvmsg libc___xnet_recvmsg
 //go:linkname libc_getexecname libc_getexecname
+//go:linkname libc_utimensat libc_utimensat
 
 type libcFunc uintptr
 
@@ -260,7 +262,8 @@ var (
 	libc_setsockopt,
 	libc_recvfrom,
 	libc___xnet_recvmsg,
-	libc_getexecname libcFunc
+	libc_getexecname,
+	libc_utimensat libcFunc
 )
 
 func Getcwd(buf []byte) (n int, err error) {
@@ -1084,3 +1087,16 @@ func getexecname() (path unsafe.Pointer, err error) {
 	}
 	return
 }
+
+func utimensat(dirfd int, path string, times *[2]Timespec) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := sysvicall6(uintptr(unsafe.Pointer(&libc_utimensat)), 3, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(times)), 0, 0, 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}

src/syscall/zsysnum_dragonfly_amd64.go

@@ -301,5 +301,6 @@ const (
 	SYS_LPATHCONF              = 533 // { int lpathconf(char *path, int name); }
 	SYS_VMM_GUEST_CTL          = 534 // { int vmm_guest_ctl(int op, struct vmm_guest_options *options); }
 	SYS_VMM_GUEST_SYNC_ADDR    = 535 // { int vmm_guest_sync_addr(long *dstaddr, long *srcaddr); }
+	SYS_UTIMENSAT              = 539 // { int utimensat(int fd, const char *path, const struct timespec *ts, int flags); }
 	SYS_ACCEPT4                = 541 // { int accept4(int s, caddr_t name, int *anamelen, int flags); }
 )

src/syscall/zsysnum_freebsd_386.go

@@ -347,4 +347,5 @@ const (
 	SYS_ACCEPT4                  = 541 // { int accept4(int s, \
 	SYS_PIPE2                    = 542 // { int pipe2(int *fildes, int flags); }
 	SYS_PROCCTL                  = 544 // { int procctl(idtype_t idtype, id_t id, \
+	SYS_UTIMENSAT                = 547 // { int utimensat(int fd, \
 )

src/syscall/zsysnum_freebsd_amd64.go

@@ -347,4 +347,5 @@ const (
 	SYS_ACCEPT4                  = 541 // { int accept4(int s, \
 	SYS_PIPE2                    = 542 // { int pipe2(int *fildes, int flags); }
 	SYS_PROCCTL                  = 544 // { int procctl(idtype_t idtype, id_t id, \
+	SYS_UTIMENSAT                = 547 // { int utimensat(int fd, \
 )

src/syscall/zsysnum_freebsd_arm.go

@@ -347,4 +347,5 @@ const (
 	SYS_ACCEPT4                  = 541 // { int accept4(int s, \
 	SYS_PIPE2                    = 542 // { int pipe2(int *fildes, int flags); }
 	SYS_PROCCTL                  = 544 // { int procctl(idtype_t idtype, id_t id, \
+	SYS_UTIMENSAT                = 547 // { int utimensat(int fd, \
 )

src/syscall/ztypes_darwin_386.go

@@ -437,6 +437,10 @@ type BpfHdr struct {
 	Pad_cgo_0 [2]byte
 }
 
+const (
+	_AT_FDCWD = -0x2
+)
+
 type Termios struct {
 	Iflag  uint32
 	Oflag  uint32

src/syscall/ztypes_darwin_amd64.go

@@ -446,6 +446,10 @@ type BpfHdr struct {
 	Pad_cgo_0 [2]byte
 }
 
+const (
+	_AT_FDCWD = -0x2
+)
+
 type Termios struct {
 	Iflag     uint64
 	Oflag     uint64

src/syscall/ztypes_darwin_arm.go

@@ -438,6 +438,10 @@ type BpfHdr struct {
 	Pad_cgo_0 [2]byte
 }
 
+const (
+	_AT_FDCWD = -0x2
+)
+
 type Termios struct {
 	Iflag  uint32
 	Oflag  uint32

src/syscall/ztypes_darwin_arm64.go

@@ -446,6 +446,10 @@ type BpfHdr struct {
 	Pad_cgo_0 [2]byte
 }
 
+const (
+	_AT_FDCWD = -0x2
+)
+
 type Termios struct {
 	Iflag     uint64
 	Oflag     uint64

src/syscall/ztypes_dragonfly_amd64.go

@@ -432,6 +432,10 @@ type BpfHdr struct {
 	Pad_cgo_0 [6]byte
 }
 
+const (
+	_AT_FDCWD = -0x64
+)
+
 type Termios struct {
 	Iflag  uint32
 	Oflag  uint32

src/syscall/ztypes_freebsd_386.go

@@ -483,6 +483,10 @@ type BpfZbufHeader struct {
 	X_bzh_pad  [5]uint32
 }
 
+const (
+	_AT_FDCWD = -0x64
+)
+
 type Termios struct {
 	Iflag  uint32
 	Oflag  uint32

src/syscall/ztypes_freebsd_amd64.go

@@ -486,6 +486,10 @@ type BpfZbufHeader struct {
 	X_bzh_pad  [5]uint32
 }
 
+const (
+	_AT_FDCWD = -0x64
+)
+
 type Termios struct {
 	Iflag  uint32
 	Oflag  uint32

src/syscall/ztypes_freebsd_arm.go

@@ -486,6 +486,10 @@ type BpfZbufHeader struct {
 	X_bzh_pad  [5]uint32
 }
 
+const (
+	_AT_FDCWD = -0x64
+)
+
 type Termios struct {
 	Iflag  uint32
 	Oflag  uint32

src/syscall/ztypes_netbsd_386.go

@@ -372,6 +372,10 @@ type BpfTimeval struct {
 	Usec int32
 }
 
+const (
+	_AT_FDCWD = -0x64
+)
+
 type Termios struct {
 	Iflag  uint32
 	Oflag  uint32

src/syscall/ztypes_netbsd_amd64.go

@@ -379,6 +379,10 @@ type BpfTimeval struct {
 	Usec int64
 }
 
+const (
+	_AT_FDCWD = -0x64
+)
+
 type Termios struct {
 	Iflag  uint32
 	Oflag  uint32

src/syscall/ztypes_netbsd_arm.go

@@ -377,6 +377,10 @@ type BpfTimeval struct {
 	Usec int32
 }
 
+const (
+	_AT_FDCWD = -0x64
+)
+
 type Termios struct {
 	Iflag  uint32
 	Oflag  uint32

src/syscall/ztypes_openbsd_386.go

@@ -430,6 +430,10 @@ type BpfTimeval struct {
 	Usec uint32
 }
 
+const (
+	_AT_FDCWD = -0x64
+)
+
 type Termios struct {
 	Iflag  uint32
 	Oflag  uint32

src/syscall/ztypes_openbsd_amd64.go

@@ -437,6 +437,10 @@ type BpfTimeval struct {
 	Usec uint32
 }
 
+const (
+	_AT_FDCWD = -0x64
+)
+
 type Termios struct {
 	Iflag  uint32
 	Oflag  uint32

src/syscall/ztypes_openbsd_arm.go

@@ -423,6 +423,10 @@ type BpfTimeval struct {
 	Usec uint32
 }
 
+const (
+	_AT_FDCWD = -0x64
+)
+
 type Termios struct {
 	Iflag  uint32
 	Oflag  uint32

src/syscall/ztypes_solaris_amd64.go

@@ -358,6 +358,10 @@ type BpfHdr struct {
 	Pad_cgo_0 [2]byte
 }
 
+const (
+	_AT_FDCWD = 0xffd19553
+)
+
 type Termios struct {
 	Iflag     uint32
 	Oflag     uint32