Files
sys/cpu/cpu_linux.go
Michael Munday 153ac47618 cpu: unexport HWCap and HWCap2
These are an implementation detail and should not have been
exported. This only affects Linux on platforms other than 386 and
amd64.

Fixes golang/go#30255.

Change-Id: Ib23b42a7309fd6093b6b9d8b6628de222a3928be
Reviewed-on: https://go-review.googlesource.com/c/163004
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
2019-02-19 09:28:55 +00:00

56 lines
1.0 KiB
Go

// 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.
//+build !amd64,!amd64p32,!386
package cpu
import (
"io/ioutil"
)
const (
_AT_HWCAP = 16
_AT_HWCAP2 = 26
procAuxv = "/proc/self/auxv"
uintSize = int(32 << (^uint(0) >> 63))
)
// For those platforms don't have a 'cpuid' equivalent we use HWCAP/HWCAP2
// These are initialized in cpu_$GOARCH.go
// and should not be changed after they are initialized.
var hwCap uint
var hwCap2 uint
func init() {
buf, err := ioutil.ReadFile(procAuxv)
if err != nil {
panic("read proc auxv failed: " + err.Error())
}
bo := hostByteOrder()
for len(buf) >= 2*(uintSize/8) {
var tag, val uint
switch uintSize {
case 32:
tag = uint(bo.Uint32(buf[0:]))
val = uint(bo.Uint32(buf[4:]))
buf = buf[8:]
case 64:
tag = uint(bo.Uint64(buf[0:]))
val = uint(bo.Uint64(buf[8:]))
buf = buf[16:]
}
switch tag {
case _AT_HWCAP:
hwCap = val
case _AT_HWCAP2:
hwCap2 = val
}
}
doinit()
}