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>
diff --git a/cpu/cpu_arm64.go b/cpu/cpu_arm64.go
index 9c87677..7bcb36c 100644
--- a/cpu/cpu_arm64.go
+++ b/cpu/cpu_arm64.go
@@ -10,8 +10,14 @@
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
