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