From 1e063eea38fe3ecc8bea4e35bc0482fa8100ea80 Mon Sep 17 00:00:00 2001
From: Dmitriy Vyukov <dvyukov@google.com>
Date: Wed, 20 Feb 2013 21:17:56 +0400
Subject: [PATCH] runtime: prepare for M's running w/o mcache Can not happen
 ATM. In preparation for the new scheduler.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7388043
---
 src/pkg/runtime/panic.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/pkg/runtime/panic.c b/src/pkg/runtime/panic.c
index a0651e4ad55..603ff62eb3c 100644
--- a/src/pkg/runtime/panic.c
+++ b/src/pkg/runtime/panic.c
@@ -382,6 +382,8 @@ nomatch:
 void
 runtime·startpanic(void)
 {
+	if(m->mcache == nil)  // can happen if called from signal handler or throw
+		m->mcache = runtime·allocmcache();
 	if(m->dying) {
 		runtime·printf("panic during panic\n");
 		runtime·exit(3);