From: Lucian Petrut <lpetrut@cloudbasesolutions.com>
Date: Thu, 2 Apr 2020 10:19:20 +0000 (+0000)
Subject: librbd: avoid broken mingw rng
X-Git-Tag: v16.1.0~652^2~7
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=70b2504671ab9ae187ab8aaec886843b03556afd;p=ceph.git

librbd: avoid broken mingw rng

std::random_device is broken when using Mingw < 9.2 [1].
It always produces the same sequence of numbers, so one critical
implication is that multiple sessions coming from different
processes will use the same identifier.

For now, we'll use boost::random::random_device when building with
Mingw.

[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85494

Signed-off-by: Lucian Petrut <lpetrut@cloudbasesolutions.com>
---

diff --git a/src/include/random.h b/src/include/random.h
index 0501a878049..f2e3e37bcd7 100644
--- a/src/include/random.h
+++ b/src/include/random.h
@@ -20,6 +20,15 @@
 #include <type_traits>
 #include <boost/optional.hpp>
 
+// Workaround for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85494
+#ifdef __MINGW32__
+#include <boost/random/random_device.hpp>
+
+using random_device_t = boost::random::random_device;
+#else
+using random_device_t = std::random_device;
+#endif
+
 // Basic random number facility (see N3551 for inspiration):
 namespace ceph::util {
 
@@ -91,7 +100,7 @@ void randomize_rng(const SeedT seed, MutexT& m, EngineT& e)
 template <typename MutexT, typename EngineT>
 void randomize_rng(MutexT& m, EngineT& e)
 {
-  std::random_device rd;
+  random_device_t rd;
  
   std::lock_guard<MutexT> lg(m);
   e.seed(rd());
@@ -107,7 +116,7 @@ void randomize_rng(const SeedT n)
 template <typename EngineT = std::default_random_engine>
 void randomize_rng()
 {
-  std::random_device rd;
+  random_device_t rd;
   detail::engine<EngineT>().seed(rd());
 }
 
@@ -232,7 +241,7 @@ template <typename NumberT>
 class random_number_generator final
 {
   std::mutex l;
-  std::random_device rd;
+  random_device_t rd;
   std::default_random_engine e;
 
   using seed_type = typename decltype(e)::result_type;
diff --git a/src/include/uuid.h b/src/include/uuid.h
index bee66c36fa3..091a0c049cb 100644
--- a/src/include/uuid.h
+++ b/src/include/uuid.h
@@ -7,6 +7,7 @@
  */
 
 #include "encoding.h"
+#include "random.h"
 
 #include <ostream>
 #include <random>
@@ -32,7 +33,7 @@ struct uuid_d {
   }
 
   void generate_random() {
-    std::random_device rng;
+    random_device_t rng;
     boost::uuids::basic_random_generator gen(rng);
     uuid = gen();
   }
diff --git a/src/librbd/Utils.cc b/src/librbd/Utils.cc
index 420f73a69bd..36e8fa353a6 100644
--- a/src/librbd/Utils.cc
+++ b/src/librbd/Utils.cc
@@ -5,6 +5,7 @@
 #include <boost/lexical_cast.hpp>
 
 #include "librbd/Utils.h"
+#include "include/random.h"
 #include "include/rbd_types.h"
 #include "include/stringify.h"
 #include "include/neorados/RADOS.hpp"
@@ -55,7 +56,7 @@ std::string generate_image_id(librados::IoCtx &ioctx) {
   librados::Rados rados(ioctx);
 
   uint64_t bid = rados.get_instance_id();
-  std::mt19937 generator{std::random_device{}()};
+  std::mt19937 generator{random_device_t{}()};
   std::uniform_int_distribution<uint32_t> distribution{0, 0xFFFFFFFF};
   uint32_t extra = distribution(generator);
 
diff --git a/src/mon/MonClient.cc b/src/mon/MonClient.cc
index edff5f50958..0840c4641a4 100644
--- a/src/mon/MonClient.cc
+++ b/src/mon/MonClient.cc
@@ -21,6 +21,7 @@
 #include <boost/range/algorithm_ext/copy_n.hpp>
 #include "common/weighted_shuffle.h"
 
+#include "include/random.h"
 #include "include/scope_guard.h"
 #include "include/stringify.h"
 
@@ -792,7 +793,7 @@ void MonClient::_add_conns(uint64_t global_id)
       auto rank_name = monmap.get_name(i);
       weights.push_back(monmap.get_weight(rank_name));
     }
-    std::random_device rd;
+    random_device_t rd;
     if (std::accumulate(begin(weights), end(weights), 0u) == 0) {
       std::shuffle(begin(ranks), end(ranks), std::mt19937{rd()});
     } else {
diff --git a/src/test/common/CMakeLists.txt b/src/test/common/CMakeLists.txt
index 4bf46a00873..6dd405e8d79 100644
--- a/src/test/common/CMakeLists.txt
+++ b/src/test/common/CMakeLists.txt
@@ -134,6 +134,7 @@ add_executable(unittest_random
   test_random.cc
   )
 add_ceph_unittest(unittest_random)
+target_link_libraries(unittest_random Boost::random)
 
 # unittest_throttle
 add_executable(unittest_throttle
diff --git a/src/tools/osdmaptool.cc b/src/tools/osdmaptool.cc
index 73ad1a535b6..afd5fe88d76 100644
--- a/src/tools/osdmaptool.cc
+++ b/src/tools/osdmaptool.cc
@@ -18,6 +18,7 @@
 #include "common/ceph_argparse.h"
 #include "common/errno.h"
 #include "common/safe_io.h"
+#include "include/random.h"
 #include "mon/health_check.h"
 #include <time.h>
 #include <algorithm>
@@ -423,7 +424,7 @@ int main(int argc, const char **argv)
     int r = clock_gettime(CLOCK_MONOTONIC, &round_start);
     assert(r == 0);
     do {
-      std::random_device rd;
+      random_device_t rd;
       std::shuffle(pools.begin(), pools.end(), std::mt19937{rd()});
       cout << "pools ";
       for (auto& i: pools)