From eb04df75cd87722f396fb66583279afe5abfb1ca Mon Sep 17 00:00:00 2001
From: Dmitriy Vyukov <dvyukov@google.com>
Date: Fri, 19 Jul 2013 18:01:33 +0400
Subject: [PATCH] runtime: prevent GC from seeing the contents of a frame in
 runfinq This holds the last finalized object and arguments to its finalizer.
 Fixes #5348.

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/11454044
---
 src/pkg/runtime/mgc0.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/pkg/runtime/mgc0.c b/src/pkg/runtime/mgc0.c
index f2c5939e0a..abf93e425b 100644
--- a/src/pkg/runtime/mgc0.c
+++ b/src/pkg/runtime/mgc0.c
@@ -2274,7 +2274,11 @@ runfinq(void)
 				framesz = sizeof(uintptr) + f->nret;
 				if(framecap < framesz) {
 					runtime·free(frame);
-					frame = runtime·mal(framesz);
+					// The frame does not contain pointers interesting for GC,
+					// all not yet finalized objects are stored in finc.
+					// If we do not mark it as FlagNoPointers,
+					// the last finalized object is not collected.
+					frame = runtime·mallocgc(framesz, FlagNoPointers, 0, 1);
 					framecap = framesz;
 				}
 				*(void**)frame = f->arg;