syscall: fix Getfsstat() for BSD

The buffer length should be the size in bytes
instead of the number of structs.

Fixes #6588.

LGTM=mikioh.mikioh
R=golang-codereviews, mikioh.mikioh, adg
CC=golang-codereviews
https://golang.org/cl/84830043

src/pkg/syscall/syscall_bsd_test.go

+// Copyright 2014 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.
+
+// +build darwin dragonfly freebsd openbsd
+
+package syscall_test
+
+import (
+	"syscall"
+	"testing"
+)
+
+const MNT_WAIT = 1
+
+func TestGetfsstat(t *testing.T) {
+	n, err := syscall.Getfsstat(nil, MNT_WAIT)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	data := make([]syscall.Statfs_t, n)
+	n, err = syscall.Getfsstat(data, MNT_WAIT)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	empty := syscall.Statfs_t{}
+	for _, stat := range data {
+		if stat == empty {
+			t.Fatal("an empty Statfs_t struct was returned")
+		}
+	}
+}

src/pkg/syscall/syscall_darwin.go

@@ -187,6 +187,21 @@ func Pipe(p []int) (err error) {
 	return
 }
 
+func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
+	var _p0 unsafe.Pointer
+	var bufsize uintptr
+	if len(buf) > 0 {
+		_p0 = unsafe.Pointer(&buf[0])
+		bufsize = unsafe.Sizeof(Statfs_t{}) * uintptr(len(buf))
+	}
+	r0, _, e1 := Syscall(SYS_GETFSSTAT64, uintptr(_p0), bufsize, uintptr(flags))
+	n = int(r0)
+	if e1 != 0 {
+		err = e1
+	}
+	return
+}
+
 /*
  * Wrapped
  */
@@ -224,7 +239,6 @@ func Kill(pid int, signum Signal) (err error) { return kill(pid, int(signum), 1)
 //sys	Getdtablesize() (size int)
 //sysnb	Getegid() (egid int)
 //sysnb	Geteuid() (uid int)
-//sys	Getfsstat(buf []Statfs_t, flags int) (n int, err error) = SYS_GETFSSTAT64
 //sysnb	Getgid() (gid int)
 //sysnb	Getpgid(pid int) (pgid int, err error)
 //sysnb	Getpgrp() (pgrp int)

src/pkg/syscall/syscall_dragonfly.go

@@ -101,6 +101,21 @@ func Pwrite(fd int, p []byte, offset int64) (n int, err error) {
 	return extpwrite(fd, p, 0, offset)
 }
 
+func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
+	var _p0 unsafe.Pointer
+	var bufsize uintptr
+	if len(buf) > 0 {
+		_p0 = unsafe.Pointer(&buf[0])
+		bufsize = unsafe.Sizeof(Statfs_t{}) * uintptr(len(buf))
+	}
+	r0, _, e1 := Syscall(SYS_GETFSSTAT, uintptr(_p0), bufsize, uintptr(flags))
+	n = int(r0)
+	if e1 != 0 {
+		err = e1
+	}
+	return
+}
+
 /*
  * Exposed directly
  */
@@ -129,7 +144,6 @@ func Pwrite(fd int, p []byte, offset int64) (n int, err error) {
 //sys	Getdtablesize() (size int)
 //sysnb	Getegid() (egid int)
 //sysnb	Geteuid() (uid int)
-//sys	Getfsstat(buf []Statfs_t, flags int) (n int, err error)
 //sysnb	Getgid() (gid int)
 //sysnb	Getpgid(pid int) (pgid int, err error)
 //sysnb	Getpgrp() (pgrp int)

src/pkg/syscall/syscall_freebsd.go

@@ -121,6 +121,21 @@ func Accept4(fd, flags int) (nfd int, sa Sockaddr, err error) {
 	return
 }
 
+func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
+	var _p0 unsafe.Pointer
+	var bufsize uintptr
+	if len(buf) > 0 {
+		_p0 = unsafe.Pointer(&buf[0])
+		bufsize = unsafe.Sizeof(Statfs_t{}) * uintptr(len(buf))
+	}
+	r0, _, e1 := Syscall(SYS_GETFSSTAT, uintptr(_p0), bufsize, uintptr(flags))
+	n = int(r0)
+	if e1 != 0 {
+		err = e1
+	}
+	return
+}
+
 /*
  * Exposed directly
  */
@@ -149,7 +164,6 @@ func Accept4(fd, flags int) (nfd int, sa Sockaddr, err error) {
 //sys	Getdtablesize() (size int)
 //sysnb	Getegid() (egid int)
 //sysnb	Geteuid() (uid int)
-//sys	Getfsstat(buf []Statfs_t, flags int) (n int, err error)
 //sysnb	Getgid() (gid int)
 //sysnb	Getpgid(pid int) (pgid int, err error)
 //sysnb	Getpgrp() (pgrp int)

src/pkg/syscall/syscall_openbsd.go

@@ -100,6 +100,21 @@ func sendfile(outfd int, infd int, offset *int64, count int) (written int, err e
 	return -1, ENOSYS
 }
 
+func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
+	var _p0 unsafe.Pointer
+	var bufsize uintptr
+	if len(buf) > 0 {
+		_p0 = unsafe.Pointer(&buf[0])
+		bufsize = unsafe.Sizeof(Statfs_t{}) * uintptr(len(buf))
+	}
+	r0, _, e1 := Syscall(SYS_GETFSSTAT, uintptr(_p0), bufsize, uintptr(flags))
+	n = int(r0)
+	if e1 != 0 {
+		err = e1
+	}
+	return
+}
+
 /*
  * Exposed directly
  */
@@ -126,7 +141,6 @@ func sendfile(outfd int, infd int, offset *int64, count int) (written int, err e
 //sys	Ftruncate(fd int, length int64) (err error)
 //sysnb	Getegid() (egid int)
 //sysnb	Geteuid() (uid int)
-//sys	Getfsstat(buf []Statfs_t, flags int) (n int, err error)
 //sysnb	Getgid() (gid int)
 //sysnb	Getpgid(pid int) (pgid int, err error)
 //sysnb	Getpgrp() (pgrp int)

src/pkg/syscall/zsyscall_darwin_386.go

@@ -591,23 +591,6 @@ func Geteuid() (uid int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(buf) > 0 {
-		_p0 = unsafe.Pointer(&buf[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall(SYS_GETFSSTAT64, uintptr(_p0), uintptr(len(buf)), uintptr(flags))
-	n = int(r0)
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Getgid() (gid int) {
 	r0, _, _ := RawSyscall(SYS_GETGID, 0, 0, 0)
 	gid = int(r0)

src/pkg/syscall/zsyscall_darwin_amd64.go

@@ -591,23 +591,6 @@ func Geteuid() (uid int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(buf) > 0 {
-		_p0 = unsafe.Pointer(&buf[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall(SYS_GETFSSTAT64, uintptr(_p0), uintptr(len(buf)), uintptr(flags))
-	n = int(r0)
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Getgid() (gid int) {
 	r0, _, _ := RawSyscall(SYS_GETGID, 0, 0, 0)
 	gid = int(r0)

src/pkg/syscall/zsyscall_dragonfly_386.go

@@ -585,23 +585,6 @@ func Geteuid() (uid int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(buf) > 0 {
-		_p0 = unsafe.Pointer(&buf[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall(SYS_GETFSSTAT, uintptr(_p0), uintptr(len(buf)), uintptr(flags))
-	n = int(r0)
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Getgid() (gid int) {
 	r0, _, _ := RawSyscall(SYS_GETGID, 0, 0, 0)
 	gid = int(r0)

src/pkg/syscall/zsyscall_dragonfly_amd64.go

@@ -585,23 +585,6 @@ func Geteuid() (uid int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(buf) > 0 {
-		_p0 = unsafe.Pointer(&buf[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall(SYS_GETFSSTAT, uintptr(_p0), uintptr(len(buf)), uintptr(flags))
-	n = int(r0)
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Getgid() (gid int) {
 	r0, _, _ := RawSyscall(SYS_GETGID, 0, 0, 0)
 	gid = int(r0)

src/pkg/syscall/zsyscall_freebsd_386.go

@@ -551,23 +551,6 @@ func Geteuid() (uid int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(buf) > 0 {
-		_p0 = unsafe.Pointer(&buf[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall(SYS_GETFSSTAT, uintptr(_p0), uintptr(len(buf)), uintptr(flags))
-	n = int(r0)
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Getgid() (gid int) {
 	r0, _, _ := RawSyscall(SYS_GETGID, 0, 0, 0)
 	gid = int(r0)

src/pkg/syscall/zsyscall_freebsd_amd64.go

@@ -551,23 +551,6 @@ func Geteuid() (uid int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(buf) > 0 {
-		_p0 = unsafe.Pointer(&buf[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall(SYS_GETFSSTAT, uintptr(_p0), uintptr(len(buf)), uintptr(flags))
-	n = int(r0)
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Getgid() (gid int) {
 	r0, _, _ := RawSyscall(SYS_GETGID, 0, 0, 0)
 	gid = int(r0)

src/pkg/syscall/zsyscall_freebsd_arm.go

@@ -551,23 +551,6 @@ func Geteuid() (uid int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(buf) > 0 {
-		_p0 = unsafe.Pointer(&buf[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall(SYS_GETFSSTAT, uintptr(_p0), uintptr(len(buf)), uintptr(flags))
-	n = int(r0)
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Getgid() (gid int) {
 	r0, _, _ := RawSyscall(SYS_GETGID, 0, 0, 0)
 	gid = int(r0)

src/pkg/syscall/zsyscall_openbsd_386.go

@@ -541,23 +541,6 @@ func Geteuid() (uid int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(buf) > 0 {
-		_p0 = unsafe.Pointer(&buf[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall(SYS_GETFSSTAT, uintptr(_p0), uintptr(len(buf)), uintptr(flags))
-	n = int(r0)
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Getgid() (gid int) {
 	r0, _, _ := RawSyscall(SYS_GETGID, 0, 0, 0)
 	gid = int(r0)

src/pkg/syscall/zsyscall_openbsd_amd64.go

@@ -541,23 +541,6 @@ func Geteuid() (uid int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(buf) > 0 {
-		_p0 = unsafe.Pointer(&buf[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
-	}
-	r0, _, e1 := Syscall(SYS_GETFSSTAT, uintptr(_p0), uintptr(len(buf)), uintptr(flags))
-	n = int(r0)
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Getgid() (gid int) {
 	r0, _, _ := RawSyscall(SYS_GETGID, 0, 0, 0)
 	gid = int(r0)