cpu: avoid illegal instruction on netbsd/arm64

On NetBSD, this package tries to read a privileged register,
which results in a SIGILL. Use the same workaround as Android and
iOS. In the future, we could use sysctl(3) instead.

Update golang/go#30824

Change-Id: Ifd9aa2a2cf4dac43341d013602d1ccb4b8d6eb6d
Reviewed-on: https://go-review.googlesource.com/c/sys/+/235097
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This commit is contained in:
Benny Siegert
2020-05-23 20:33:20 +02:00
committed by Tobias Klauser
parent fe76b779f2
commit 0598657881

View File

@@ -10,8 +10,14 @@ const cacheLineSize = 64
func init() {
switch runtime.GOOS {
case "android", "darwin":
case "android", "darwin", "netbsd":
// Android and iOS don't seem to allow reading these registers.
//
// NetBSD:
// ID_AA64ISAR0_EL1 is a privileged register and cannot be read from EL0.
// It can be read via sysctl(3). Example for future implementers:
// https://nxr.netbsd.org/xref/src/usr.sbin/cpuctl/arch/aarch64.c
//
// Fake the minimal features expected by
// TestARM64minimalFeatures.
ARM64.HasASIMD = true