From d1015f3e58e50c3e6f958391a9174fc15e030e83 Mon Sep 17 00:00:00 2001
From: Cherry Zhang <cherryyz@google.com>
Date: Fri, 26 Jun 2020 11:57:08 -0400
Subject: [PATCH] runtime: don't preempt if preemption is disabled

If asyncpreemptoff is set, don't preempt upon receiving a SIGURG.

Fixes #38531.

Change-Id: I6d9a828b45c199d3e479cbdfe17a896a40d540f9
Reviewed-on: https://go-review.googlesource.com/c/go/+/240121
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
---
 src/runtime/signal_unix.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/runtime/signal_unix.go b/src/runtime/signal_unix.go
index ba3e21ae2e..dd6d79f8ec 100644
--- a/src/runtime/signal_unix.go
+++ b/src/runtime/signal_unix.go
@@ -536,7 +536,7 @@ func sighandler(sig uint32, info *siginfo, ctxt unsafe.Pointer, gp *g) {
 		return
 	}
 
-	if sig == sigPreempt {
+	if sig == sigPreempt && debug.asyncpreemptoff == 0 {
 		// Might be a preemption signal.
 		doSigPreempt(gp, c)
 		// Even if this was definitely a preemption signal, it
-- 
2.50.0