syscall: fix mkall.sh, mksyscall_linux.pl, and regen for Linux/ARM

CL 3075041 says ARM is not little-endian, but my test suggests otherwise.
My test program is:

    package main
    import ("fmt"; "syscall"; "os")
    func main() {
       err := syscall.Fallocate(1, 1/*FALLOC_FL_KEEP_SIZE*/, 0, int64(40960));
       fmt.Fprintln(os.Stderr, err)
    }

Without this CL, ./test > testfile will show: file too large; and strace shows:
    fallocate(1, 01, 0, 175921860444160)    = -1 EFBIG (File too large)
With this CL, ./test > testfile will show: <nil>; and strace shows:
    fallocate(1, 01, 0, 40960)              = 0

Quoting rsc:
"[It turns out that] ARM syscall ABI requires 64-bit arguments to use an
(even, odd) register pair, not an (odd, even) pair. Switching to "big-endian"
worked because it ended up using the high 32-bits (always zero in the tests
we had) as the padding word, because the 64-bit argument was the last one,
and because we fill in zeros for the rest of the system call arguments, up to
six. So it happened to work."

I updated mksyscall_linux.pl to accommodate the register pair ABI requirement,
and removed all hand-tweaked syscall routines in favor of the auto-generated
ones. These including: Ftruncate, Truncate, Pread and Pwrite.

Some recent Linux/ARM distributions do not bundle kernel asm headers,
so instead we always get latest asm/unistd.h from git.kernel.org (just like
what we do for FreeBSD).

R=ken, r, rsc, r, dave, iant
CC=golang-dev
https://golang.org/cl/5726051

src/pkg/syscall/mkall.sh

@@ -144,8 +144,8 @@ linux_amd64)
 	;;
 linux_arm)
 	mkerrors="$mkerrors"
-	mksyscall="./mksyscall.pl -b32"
-	mksysnum="./mksysnum_linux.pl /usr/include/asm/unistd.h"
+	mksyscall="./mksyscall.pl -l32 -arm"
+	mksysnum="curl -s 'http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob_plain;f=arch/arm/include/asm/unistd.h;hb=HEAD' | ./mksysnum_linux.pl"
 	mktypes="GOARCH=$GOARCH go tool cgo -godefs"
 	;;
 netbsd_386)

src/pkg/syscall/mksyscall.pl

@@ -27,6 +27,7 @@ my $_32bit = "";
 my $plan9 = 0;
 my $openbsd = 0;
 my $netbsd = 0;
+my $arm = 0; # 64-bit value should use (even, odd)-pair
 
 if($ARGV[0] eq "-b32") {
 	$_32bit = "big-endian";
@@ -47,6 +48,10 @@ if($ARGV[0] eq "-netbsd") {
 	$netbsd = 1;
 	shift;
 }
+if($ARGV[0] eq "-arm") {
+	$arm = 1;
+	shift;
+}
 
 if($ARGV[0] =~ /^-/) {
 	print STDERR "usage: mksyscall.pl [-b32 | -l32] [file ...]\n";
@@ -135,6 +140,11 @@ while(<>) {
 				push @args, "uintptr($name)";
 			}
 		} elsif($type eq "int64" && $_32bit ne "") {
+			if(@args % 2 && $arm) {
+				# arm abi specifies 64-bit argument uses 
+				# (even, odd) pair
+				push @args, "0"
+			}
 			if($_32bit eq "big-endian") {
 				push @args, "uintptr($name>>32)", "uintptr($name)";
 			} else {

src/pkg/syscall/syscall_linux_arm.go

@@ -4,8 +4,6 @@
 
 package syscall
 
-import "unsafe"
-
 func Getpagesize() int { return 4096 }
 
 func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
@@ -23,52 +21,6 @@ func NsecToTimeval(nsec int64) (tv Timeval) {
 	return
 }
 
-// Pread and Pwrite are special: they insert padding before the int64.
-
-func Pread(fd int, p []byte, offset int64) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(p) > 0 {
-		_p0 = unsafe.Pointer(&p[0])
-	}
-	r0, _, e1 := Syscall6(SYS_PREAD64, uintptr(fd), uintptr(_p0), uintptr(len(p)), 0, uintptr(offset), uintptr(offset>>32))
-	n = int(r0)
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-func Pwrite(fd int, p []byte, offset int64) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(p) > 0 {
-		_p0 = unsafe.Pointer(&p[0])
-	}
-	r0, _, e1 := Syscall6(SYS_PWRITE64, uintptr(fd), uintptr(_p0), uintptr(len(p)), 0, uintptr(offset), uintptr(offset>>32))
-	n = int(r0)
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-func Ftruncate(fd int, length int64) (err error) {
-	// ARM EABI requires 64-bit arguments should be put in a pair
-	// of registers from an even register number.
-	_, _, e1 := Syscall6(SYS_FTRUNCATE64, uintptr(fd), 0, uintptr(length), uintptr(length>>32), 0, 0)
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-func Truncate(path string, length int64) (err error) {
-	_, _, e1 := Syscall6(SYS_TRUNCATE64, uintptr(unsafe.Pointer(StringBytePtr(path))), 0, uintptr(length), uintptr(length>>32), 0, 0)
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
 // Seek is defined in assembly.
 
 func Seek(fd int, offset int64, whence int) (newoffset int64, err error)
@@ -118,6 +70,11 @@ func Seek(fd int, offset int64, whence int) (newoffset int64, err error)
 //sysnb	Gettimeofday(tv *Timeval) (err error)
 //sysnb	Time(t *Time_t) (tt Time_t, err error)
 
+//sys   Pread(fd int, p []byte, offset int64) (n int, err error) = SYS_PREAD64
+//sys   Pwrite(fd int, p []byte, offset int64) (n int, err error) = SYS_PWRITE64
+//sys	Truncate(path string, length int64) (err error) = SYS_TRUNCATE64
+//sys	Ftruncate(fd int, length int64) (err error) = SYS_FTRUNCATE64
+
 //sys	mmap2(addr uintptr, length uintptr, prot int, flags int, fd int, pageOffset uintptr) (xaddr uintptr, err error)
 
 func mmap(addr uintptr, length uintptr, prot int, flags int, fd int, offset int64) (xaddr uintptr, err error) {

src/pkg/syscall/zsyscall_linux_arm.go

-// mksyscall.pl -b32 syscall_linux.go syscall_linux_arm.go
+// mksyscall.pl -l32 -arm syscall_linux.go syscall_linux_arm.go
 // MACHINE GENERATED BY THE COMMAND ABOVE; DO NOT EDIT
 
 package syscall
@@ -287,7 +287,7 @@ func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func Fallocate(fd int, mode uint32, off int64, len int64) (err error) {
-	_, _, e1 := Syscall6(SYS_FALLOCATE, uintptr(fd), uintptr(mode), uintptr(off>>32), uintptr(off), uintptr(len>>32), uintptr(len))
+	_, _, e1 := Syscall6(SYS_FALLOCATE, uintptr(fd), uintptr(mode), uintptr(off), uintptr(off>>32), uintptr(len), uintptr(len>>32))
 	if e1 != 0 {
 		err = e1
 	}
@@ -784,7 +784,7 @@ func Sysinfo(info *Sysinfo_t) (err error) {
 
 func Tee(rfd int, wfd int, len int, flags int) (n int64, err error) {
 	r0, r1, e1 := Syscall6(SYS_TEE, uintptr(rfd), uintptr(wfd), uintptr(len), uintptr(flags), 0, 0)
-	n = int64(int64(r0)<<32 | int64(r1))
+	n = int64(int64(r1)<<32 | int64(r0))
 	if e1 != 0 {
 		err = e1
 	}
@@ -1458,6 +1458,60 @@ func Time(t *Time_t) (tt Time_t, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Pread(fd int, p []byte, offset int64) (n int, err error) {
+	var _p0 unsafe.Pointer
+	if len(p) > 0 {
+		_p0 = unsafe.Pointer(&p[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	r0, _, e1 := Syscall6(SYS_PREAD64, uintptr(fd), uintptr(_p0), uintptr(len(p)), 0, uintptr(offset), uintptr(offset>>32))
+	n = int(r0)
+	if e1 != 0 {
+		err = e1
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func Pwrite(fd int, p []byte, offset int64) (n int, err error) {
+	var _p0 unsafe.Pointer
+	if len(p) > 0 {
+		_p0 = unsafe.Pointer(&p[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	r0, _, e1 := Syscall6(SYS_PWRITE64, uintptr(fd), uintptr(_p0), uintptr(len(p)), 0, uintptr(offset), uintptr(offset>>32))
+	n = int(r0)
+	if e1 != 0 {
+		err = e1
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func Truncate(path string, length int64) (err error) {
+	_, _, e1 := Syscall6(SYS_TRUNCATE64, uintptr(unsafe.Pointer(StringBytePtr(path))), 0, uintptr(length), uintptr(length>>32), 0, 0)
+	if e1 != 0 {
+		err = e1
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func Ftruncate(fd int, length int64) (err error) {
+	_, _, e1 := Syscall6(SYS_FTRUNCATE64, uintptr(fd), 0, uintptr(length), uintptr(length>>32), 0, 0)
+	if e1 != 0 {
+		err = e1
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func mmap2(addr uintptr, length uintptr, prot int, flags int, fd int, pageOffset uintptr) (xaddr uintptr, err error) {
 	r0, _, e1 := Syscall6(SYS_MMAP2, uintptr(addr), uintptr(length), uintptr(prot), uintptr(flags), uintptr(fd), uintptr(pageOffset))
 	xaddr = uintptr(r0)

src/pkg/syscall/zsysnum_linux_arm.go

-// mksysnum_linux.pl /usr/include/asm/unistd.h
+// mksysnum_linux.pl 
 // MACHINE GENERATED BY THE ABOVE COMMAND; DO NOT EDIT
 
 package syscall
@@ -338,5 +338,17 @@ const (
 	SYS_PWRITEV                = 362
 	SYS_RT_TGSIGQUEUEINFO      = 363
 	SYS_PERF_EVENT_OPEN        = 364
+	SYS_RECVMMSG               = 365
 	SYS_ACCEPT4                = 366
+	SYS_FANOTIFY_INIT          = 367
+	SYS_FANOTIFY_MARK          = 368
+	SYS_PRLIMIT64              = 369
+	SYS_NAME_TO_HANDLE_AT      = 370
+	SYS_OPEN_BY_HANDLE_AT      = 371
+	SYS_CLOCK_ADJTIME          = 372
+	SYS_SYNCFS                 = 373
+	SYS_SENDMMSG               = 374
+	SYS_SETNS                  = 375
+	SYS_PROCESS_VM_READV       = 376
+	SYS_PROCESS_VM_WRITEV      = 377
 )

src/pkg/syscall/ztypes_linux_arm.go

@@ -233,7 +233,7 @@ type Cmsghdr struct {
 	Len          uint32
 	Level        int32
 	Type         int32
-	X__cmsg_data [0]byte
+	X__cmsg_data [0]uint8
 }
 
 type Inet4Pktinfo struct {
@@ -301,7 +301,7 @@ const (
 	IFLA_LINKINFO     = 0x12
 	IFLA_NET_NS_PID   = 0x13
 	IFLA_IFALIAS      = 0x14
-	IFLA_MAX          = 0x14
+	IFLA_MAX          = 0x1c
 	RT_SCOPE_UNIVERSE = 0x0
 	RT_SCOPE_SITE     = 0xc8
 	RT_SCOPE_LINK     = 0xfd
@@ -435,7 +435,7 @@ type InotifyEvent struct {
 	Mask   uint32
 	Cookie uint32
 	Len    uint32
-	Name   [0]byte
+	Name   [0]uint8
 }
 
 const SizeofInotifyEvent = 0x10