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

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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
This commit is contained in:
Shenghou Ma 2012-03-06 03:12:11 +08:00
parent 1042d7d5ef
commit 6e211225d7
7 changed files with 149 additions and 64 deletions
Download patch file Download diff file Expand all files Collapse all files

53
src/pkg/syscall/syscall_linux_arm.go
View file

@ -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) {