From 15cf5378b306de9782adeb23b89c70b090598369 Mon Sep 17 00:00:00 2001
From: Maik Riechert <maik.riechert@arcor.de>
Date: Thu, 2 May 2019 13:46:51 +0100
Subject: [PATCH] make use of RDTSC optional as it may not be available

One example is when using seccomp with PR_SET_TSC set to PR_TSC_SIGSEGV.
---
 src/google/protobuf/map.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/google/protobuf/map.h b/src/google/protobuf/map.h
index 2750c023b9..6619fc81c4 100644
--- a/src/google/protobuf/map.h
+++ b/src/google/protobuf/map.h
@@ -937,7 +937,7 @@ class Map {
     // Return a randomish value.
     size_type Seed() const {
       size_type s = static_cast<size_type>(reinterpret_cast<uintptr_t>(this));
-#if defined(__x86_64__) && defined(__GNUC__)
+#if defined(__x86_64__) && defined(__GNUC__) && !defined(GOOGLE_PROTOBUF_NO_RDTSC)
       uint32 hi, lo;
       asm("rdtsc" : "=a"(lo), "=d"(hi));
       s += ((static_cast<uint64>(hi) << 32) | lo);