From 34d413f562fb4de78a8ea84ec3fed252c3667820 Mon Sep 17 00:00:00 2001
From: Russ Cox <rsc@golang.org>
Date: Thu, 23 Sep 2010 23:04:32 -0400
Subject: [PATCH] runtime: fix unwindstack crash

Bug and fix identified by Alexey Gokhberg.
Fixes #1135.

R=r, brainman
CC=golang-dev
https://golang.org/cl/2198046
---
 src/pkg/runtime/proc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/pkg/runtime/proc.c b/src/pkg/runtime/proc.c
index 1d1b05969c..9483e4c290 100644
--- a/src/pkg/runtime/proc.c
+++ b/src/pkg/runtime/proc.c
@@ -956,7 +956,8 @@ unwindstack(G *gp, byte *sp)
 			break;
 		gp->stackbase = top->stackbase;
 		gp->stackguard = top->stackguard;
-		free(stk);
+		if(top->free)
+			stackfree(stk);
 	}
 
 	if(sp != nil && (sp < gp->stackguard - StackGuard || gp->stackbase < sp)) {
-- 
2.50.0