From d1c6c6004be6d2c3ad030c5c1ef5ae1c84c7d293 Mon Sep 17 00:00:00 2001
From: Dmitriy Vyukov <dvyukov@google.com>
Date: Tue, 4 Mar 2014 11:42:02 +0400
Subject: [PATCH] cmd/go: fix data race on buildLdflags Fixes #7438.

LGTM=rsc
R=golang-codereviews
CC=bradfitz, golang-codereviews, iant, rsc
https://golang.org/cl/70420044
---
 src/cmd/go/build.go | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/cmd/go/build.go b/src/cmd/go/build.go
index 6c9b9f7e503..bf30be70e4d 100644
--- a/src/cmd/go/build.go
+++ b/src/cmd/go/build.go
@@ -1714,6 +1714,8 @@ func (gcToolchain) ld(b *builder, p *Package, out string, allactions []*action,
 		}
 	}
 	ldflags := buildLdflags
+	// Limit slice capacity so that concurrent appends do not race on the shared array.
+	ldflags = ldflags[:len(ldflags):len(ldflags)]
 	if buildContext.InstallSuffix != "" {
 		ldflags = append(ldflags, "-installsuffix", buildContext.InstallSuffix)
 	}