runtime: disable async preemption on darwin/arm(64) if no cgo
On darwin, we use libc calls, and cgo is required on ARM and
ARM64 so we have TLS set up to save/restore G during C calls. If
cgo is absent, we cannot save/restore G in TLS, and if a signal
is received during C execution we cannot get the G. Therefore
don't send signals (and hope that we won't receive any signal
during C execution).
This can only happen in the go_bootstrap program (otherwise cgo
is required).
Fixes #35800.
Change-Id: I6c02a9378af02c19d32749a42db45165b578188d
Reviewed-on: https://go-review.googlesource.com/c/go/+/208818
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/src/runtime/signal_unix.go b/src/runtime/signal_unix.go
index 756467f..3861cac 100644
--- a/src/runtime/signal_unix.go
+++ b/src/runtime/signal_unix.go
@@ -349,6 +349,16 @@
// yet, so doSigPreempt won't work.
return
}
+ if GOOS == "darwin" && (GOARCH == "arm" || GOARCH == "arm64") && !iscgo {
+ // On darwin, we use libc calls, and cgo is required on ARM and ARM64
+ // so we have TLS set up to save/restore G during C calls. If cgo is
+ // absent, we cannot save/restore G in TLS, and if a signal is
+ // received during C execution we cannot get the G. Therefore don't
+ // send signals.
+ // This can only happen in the go_bootstrap program (otherwise cgo is
+ // required).
+ return
+ }
signalM(mp, sigPreempt)
}
