From: Dmitriy Vyukov <dvyukov@google.com>
Date: Sun, 7 Apr 2013 03:00:45 +0000 (-0700)
Subject: runtime: reset typed dangling pointer
X-Git-Tag: go1.1rc2~163
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=77354c39f9b9b35537951c4d98868b88214bf8dd;p=gostls13.git

runtime: reset typed dangling pointer
If for whatever reason seh points into Go heap region,
the dangling pointer will cause memory corruption during GC.
Update #5193.

R=golang-dev, alex.brainman, iant
CC=golang-dev
https://golang.org/cl/8402045
---

diff --git a/src/pkg/runtime/proc.c b/src/pkg/runtime/proc.c
index eec7531e15..438de78b09 100644
--- a/src/pkg/runtime/proc.c
+++ b/src/pkg/runtime/proc.c
@@ -695,6 +695,7 @@ runtime·dropm(void)
 
 	// Undo whatever initialization minit did during needm.
 	runtime·unminit();
+	m->seh = nil;  // reset dangling typed pointer
 
 	// Clear m and g, and return m to the extra list.
 	// After the call to setmg we can only call nosplit functions.