syscall: move uses of Syscall to libSystem on darwin

Miscellaneous additional conversions from raw syscalls
to using their libc equivalent.

Update #17490

Change-Id: If9ab22cc1d676c1f20fb161ebf02b0c28f71585d
Reviewed-on: https://go-review.googlesource.com/c/148257
Run-TryBot: Keith Randall <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>
Reviewed-by: Brad Fitzpatrick <[email protected]>
Reviewed-by: Ian Lance Taylor <[email protected]>

Author: randall77

src/syscall/bpf_bsd.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin dragonfly freebsd netbsd openbsd
+// +build dragonfly freebsd netbsd openbsd
 
 // Berkeley packet filter for BSD variants
 

src/syscall/bpf_darwin.go

@@ -0,0 +1,185 @@
+// Copyright 2018 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.
+
+// Berkeley packet filter for Darwin
+
+package syscall
+
+import (
+	"unsafe"
+)
+
+// Deprecated: Use golang.org/x/net/bpf instead.
+func BpfStmt(code, k int) *BpfInsn {
+	return &BpfInsn{Code: uint16(code), K: uint32(k)}
+}
+
+// Deprecated: Use golang.org/x/net/bpf instead.
+func BpfJump(code, k, jt, jf int) *BpfInsn {
+	return &BpfInsn{Code: uint16(code), Jt: uint8(jt), Jf: uint8(jf), K: uint32(k)}
+}
+
+// Deprecated: Use golang.org/x/net/bpf instead.
+func BpfBuflen(fd int) (int, error) {
+	var l int
+	err := ioctlPtr(fd, BIOCGBLEN, unsafe.Pointer(&l))
+	if err != nil {
+		return 0, err
+	}
+	return l, nil
+}
+
+// Deprecated: Use golang.org/x/net/bpf instead.
+func SetBpfBuflen(fd, l int) (int, error) {
+	err := ioctlPtr(fd, BIOCSBLEN, unsafe.Pointer(&l))
+	if err != nil {
+		return 0, err
+	}
+	return l, nil
+}
+
+// Deprecated: Use golang.org/x/net/bpf instead.
+func BpfDatalink(fd int) (int, error) {
+	var t int
+	err := ioctlPtr(fd, BIOCGDLT, unsafe.Pointer(&t))
+	if err != nil {
+		return 0, err
+	}
+	return t, nil
+}
+
+// Deprecated: Use golang.org/x/net/bpf instead.
+func SetBpfDatalink(fd, t int) (int, error) {
+	err := ioctlPtr(fd, BIOCSDLT, unsafe.Pointer(&t))
+	if err != nil {
+		return 0, err
+	}
+	return t, nil
+}
+
+// Deprecated: Use golang.org/x/net/bpf instead.
+func SetBpfPromisc(fd, m int) error {
+	err := ioctlPtr(fd, BIOCPROMISC, unsafe.Pointer(&m))
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// Deprecated: Use golang.org/x/net/bpf instead.
+func FlushBpf(fd int) error {
+	err := ioctlPtr(fd, BIOCFLUSH, nil)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+type ivalue struct {
+	name  [IFNAMSIZ]byte
+	value int16
+}
+
+// Deprecated: Use golang.org/x/net/bpf instead.
+func BpfInterface(fd int, name string) (string, error) {
+	var iv ivalue
+	err := ioctlPtr(fd, BIOCGETIF, unsafe.Pointer(&iv))
+	if err != nil {
+		return "", err
+	}
+	return name, nil
+}
+
+// Deprecated: Use golang.org/x/net/bpf instead.
+func SetBpfInterface(fd int, name string) error {
+	var iv ivalue
+	copy(iv.name[:], []byte(name))
+	err := ioctlPtr(fd, BIOCSETIF, unsafe.Pointer(&iv))
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// Deprecated: Use golang.org/x/net/bpf instead.
+func BpfTimeout(fd int) (*Timeval, error) {
+	var tv Timeval
+	err := ioctlPtr(fd, BIOCGRTIMEOUT, unsafe.Pointer(&tv))
+	if err != nil {
+		return nil, err
+	}
+	return &tv, nil
+}
+
+// Deprecated: Use golang.org/x/net/bpf instead.
+func SetBpfTimeout(fd int, tv *Timeval) error {
+	err := ioctlPtr(fd, BIOCSRTIMEOUT, unsafe.Pointer(tv))
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// Deprecated: Use golang.org/x/net/bpf instead.
+func BpfStats(fd int) (*BpfStat, error) {
+	var s BpfStat
+	err := ioctlPtr(fd, BIOCGSTATS, unsafe.Pointer(&s))
+	if err != nil {
+		return nil, err
+	}
+	return &s, nil
+}
+
+// Deprecated: Use golang.org/x/net/bpf instead.
+func SetBpfImmediate(fd, m int) error {
+	err := ioctlPtr(fd, BIOCIMMEDIATE, unsafe.Pointer(&m))
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// Deprecated: Use golang.org/x/net/bpf instead.
+func SetBpf(fd int, i []BpfInsn) error {
+	var p BpfProgram
+	p.Len = uint32(len(i))
+	p.Insns = (*BpfInsn)(unsafe.Pointer(&i[0]))
+	err := ioctlPtr(fd, BIOCSETF, unsafe.Pointer(&p))
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// Deprecated: Use golang.org/x/net/bpf instead.
+func CheckBpfVersion(fd int) error {
+	var v BpfVersion
+	err := ioctlPtr(fd, BIOCVERSION, unsafe.Pointer(&v))
+	if err != nil {
+		return err
+	}
+	if v.Major != BPF_MAJOR_VERSION || v.Minor != BPF_MINOR_VERSION {
+		return EINVAL
+	}
+	return nil
+}
+
+// Deprecated: Use golang.org/x/net/bpf instead.
+func BpfHeadercmpl(fd int) (int, error) {
+	var f int
+	err := ioctlPtr(fd, BIOCGHDRCMPLT, unsafe.Pointer(&f))
+	if err != nil {
+		return 0, err
+	}
+	return f, nil
+}
+
+// Deprecated: Use golang.org/x/net/bpf instead.
+func SetBpfHeadercmpl(fd, f int) error {
+	err := ioctlPtr(fd, BIOCSHDRCMPLT, unsafe.Pointer(&f))
+	if err != nil {
+		return err
+	}
+	return nil
+}

src/syscall/exec_unix.go

@@ -248,7 +248,8 @@ func runtime_AfterExec()
 
 // execveLibc is non-nil on OS using libc syscall, set to execve in exec_libc.go; this
 // avoids a build dependency for other platforms.
-var execveLibc func(path uintptr, argv uintptr, envp uintptr) (err Errno)
+var execveLibc func(path uintptr, argv uintptr, envp uintptr) Errno
+var execveDarwin func(path *byte, argv **byte, envp **byte) error
 
 // Exec invokes the execve(2) system call.
 func Exec(argv0 string, argv []string, envv []string) (err error) {
@@ -266,13 +267,16 @@ func Exec(argv0 string, argv []string, envv []string) (err error) {
 	}
 	runtime_BeforeExec()
 
-	var err1 Errno
+	var err1 error
 	if runtime.GOOS == "solaris" || runtime.GOOS == "aix" {
 		// RawSyscall should never be used on Solaris or AIX.
 		err1 = execveLibc(
 			uintptr(unsafe.Pointer(argv0p)),
 			uintptr(unsafe.Pointer(&argvp[0])),
 			uintptr(unsafe.Pointer(&envvp[0])))
+	} else if runtime.GOOS == "darwin" {
+		// Similarly on Darwin.
+		err1 = execveDarwin(argv0p, &argvp[0], &envvp[0])
 	} else {
 		_, _, err1 = RawSyscall(SYS_EXECVE,
 			uintptr(unsafe.Pointer(argv0p)),

src/syscall/flock.go

@@ -1,4 +1,4 @@
-// +build linux darwin freebsd openbsd netbsd dragonfly
+// +build linux freebsd openbsd netbsd dragonfly
 
 // Copyright 2014 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/syscall/flock_darwin.go

@@ -0,0 +1,13 @@
+// Copyright 2018 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.
+
+package syscall
+
+import "unsafe"
+
+// FcntlFlock performs a fcntl syscall for the F_GETLK, F_SETLK or F_SETLKW command.
+func FcntlFlock(fd uintptr, cmd int, lk *Flock_t) error {
+	_, err := fcntlPtr(int(fd), cmd, unsafe.Pointer(lk))
+	return err
+}

src/syscall/mkasm_darwin.go

@@ -33,6 +33,8 @@ func main() {
 	}
 	in := string(in1) + string(in2) + string(in3)
 
+	trampolines := map[string]bool{}
+
 	var out bytes.Buffer
 
 	fmt.Fprintf(&out, "// go run mkasm_darwin.go %s\n", strings.Join(os.Args[1:], " "))
@@ -43,8 +45,11 @@ func main() {
 			continue
 		}
 		fn := line[5 : len(line)-13]
-		fmt.Fprintf(&out, "TEXT ·%s_trampoline(SB),NOSPLIT,$0-0\n", fn)
-		fmt.Fprintf(&out, "\tJMP\t%s(SB)\n", fn)
+		if !trampolines[fn] {
+			trampolines[fn] = true
+			fmt.Fprintf(&out, "TEXT ·%s_trampoline(SB),NOSPLIT,$0-0\n", fn)
+			fmt.Fprintf(&out, "\tJMP\t%s(SB)\n", fn)
+		}
 	}
 	err = ioutil.WriteFile(fmt.Sprintf("zsyscall_darwin_%s.s", arch), out.Bytes(), 0644)
 	if err != nil {

src/syscall/mksyscall.pl

@@ -99,6 +99,9 @@ ($)
 	return ($1, $2);
 }
 
+# set of trampolines we've already generated
+my %trampolines;
+
 my $text = "";
 while(<>) {
 	chomp;
@@ -338,14 +341,17 @@ ($)
 	$text .= "\treturn\n";
 	$text .= "}\n\n";
 	if($darwin) {
-		# The assembly trampoline that jumps to the libc routine.
-		$text .= "func ${funcname}_trampoline()\n";
-		# Map syscall.funcname to just plain funcname.
-		# (The jump to this function is in the assembly trampoline, generated by mksyscallasm_darwin.go.)
-		$text .= "//go:linkname $funcname $funcname\n";
-		# Tell the linker that funcname can be found in libSystem using varname without the libc_ prefix.
-		my $basename = substr $funcname, 5;
-		$text .= "//go:cgo_import_dynamic $funcname $basename \"/usr/lib/libSystem.B.dylib\"\n";
+		if (not exists $trampolines{$funcname}) {
+			$trampolines{$funcname} = 1;
+			# The assembly trampoline that jumps to the libc routine.
+			$text .= "func ${funcname}_trampoline()\n";
+			# Map syscall.funcname to just plain funcname.
+			# (The jump to this function is in the assembly trampoline, generated by mksyscallasm_darwin.go.)
+			$text .= "//go:linkname $funcname $funcname\n";
+			# Tell the linker that funcname can be found in libSystem using varname without the libc_ prefix.
+			my $basename = substr $funcname, 5;
+			$text .= "//go:cgo_import_dynamic $funcname $basename \"/usr/lib/libSystem.B.dylib\"\n";
+		}
 	}
 }
 

src/syscall/syscall_darwin.go

@@ -339,9 +339,15 @@ func Kill(pid int, signum Signal) (err error) { return kill(pid, int(signum), 1)
 //sys   munmap(addr uintptr, length uintptr) (err error)
 //sysnb fork() (pid int, err error)
 //sysnb ioctl(fd int, req int, arg int) (err error)
-//sysnb execve(path *byte, argv *byte, envp *byte) (err error)
+//sysnb ioctlPtr(fd int, req uint, arg unsafe.Pointer) (err error) = SYS_ioctl
+//sysnb execve(path *byte, argv **byte, envp **byte) (err error)
 //sysnb exit(res int) (err error)
 //sys	sysctl(mib []_C_int, old *byte, oldlen *uintptr, new *byte, newlen uintptr) (err error)
+//sys	fcntlPtr(fd int, cmd int, arg unsafe.Pointer) (val int, err error) = SYS_fcntl
+
+func init() {
+	execveDarwin = execve
+}
 
 func readlen(fd int, buf *byte, nbuf int) (n int, err error) {
 	r0, _, e1 := syscall(funcPC(libc_read_trampoline), uintptr(fd), uintptr(unsafe.Pointer(buf)), uintptr(nbuf))