From 29cb57c5bda37f1c5a58b315fc5619835cc53467 Mon Sep 17 00:00:00 2001
From: Ian Lance Taylor <iant@golang.org>
Date: Fri, 8 Dec 2017 16:05:22 -0800
Subject: [PATCH] runtime: don't use MAP_STACK in SigStack test

On DragonFly mmap with MAP_STACK returns the top of the region, not
the bottom. Rather than try to cope, just don't use the flag anywhere.

Fixes #23061

Change-Id: Ib5df4dd7c934b3efecfc4bc87f8989b4c37555d7
Reviewed-on: https://go-review.googlesource.com/83035
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
---
 src/runtime/testdata/testprogcgo/sigstack.go | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/src/runtime/testdata/testprogcgo/sigstack.go b/src/runtime/testdata/testprogcgo/sigstack.go
index e30a5592dc..492dfeff7f 100644
--- a/src/runtime/testdata/testprogcgo/sigstack.go
+++ b/src/runtime/testdata/testprogcgo/sigstack.go
@@ -17,15 +17,11 @@ package main
 #include <stdlib.h>
 #include <sys/mman.h>
 
-#ifndef MAP_STACK
-#define MAP_STACK 0
-#endif
-
 extern void SigStackCallback();
 
 static void* WithSigStack(void* arg __attribute__((unused))) {
 	// Set up an alternate system stack.
-	void* base = mmap(0, SIGSTKSZ, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON|MAP_STACK, -1, 0);
+	void* base = mmap(0, SIGSTKSZ, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON, -1, 0);
 	if (base == MAP_FAILED) {
 		perror("mmap failed");
 		abort();