From 79f9f3a1ecef1f182faac3b4f700ef756c8316bf Mon Sep 17 00:00:00 2001
From: Cory Perry <killogge@gmail.com>
Date: Mon, 1 Jan 2018 10:36:02 -0800
Subject: [PATCH] Fix segfault and deadlock in CUDAMiner.

* Add stopWorking() to destructor before pause() to prevent workLoop from continuing on deleted members.
* Scope minerWork lock to just the m_miners member, preventing deadlock with collectHashRate.
* Fix race with hashrateTimer by canceling and removing after serviceThread is joined to prevent retriggering the timer in serviceThread.
* Add boost::system to target_link_libraries for devcore for those that don't compile with stratum.
---
 libdevcore/CMakeLists.txt    |  2 +-
 libethash-cuda/CUDAMiner.cpp |  3 ++-
 libethcore/Farm.h            | 16 +++++++++-------
 3 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/libdevcore/CMakeLists.txt b/libdevcore/CMakeLists.txt
index bcea5399da..a85ce7b562 100644
--- a/libdevcore/CMakeLists.txt
+++ b/libdevcore/CMakeLists.txt
@@ -4,5 +4,5 @@ file(GLOB SOURCES "*.cpp")
 find_package(Threads)
 
 add_library(devcore ${SOURCES} ${HEADERS})
-target_link_libraries(devcore PUBLIC Boost::boost)
+target_link_libraries(devcore PUBLIC Boost::boost Boost::system)
 target_link_libraries(devcore PRIVATE Threads::Threads)
diff --git a/libethash-cuda/CUDAMiner.cpp b/libethash-cuda/CUDAMiner.cpp
index e716cea624..d563144f46 100644
--- a/libethash-cuda/CUDAMiner.cpp
+++ b/libethash-cuda/CUDAMiner.cpp
@@ -96,6 +96,7 @@ CUDAMiner::CUDAMiner(FarmFace& _farm, unsigned _index) :
 
 CUDAMiner::~CUDAMiner()
 {
+	stopWorking();
 	pause();
 	delete m_miner;
 	delete m_hook;
@@ -189,7 +190,7 @@ void CUDAMiner::workLoop()
 			if (current.exSizeBits >= 0) 
 				startN = current.startNonce | ((uint64_t)index << (64 - 4 - current.exSizeBits)); // this can support up to 16 devices
 			m_miner->search(current.header.data(), upper64OfBoundary, *m_hook, (current.exSizeBits >= 0), startN);
-			
+
 			// Check if we should stop.
 			if (shouldStop())
 			{
diff --git a/libethcore/Farm.h b/libethcore/Farm.h
index aa7ce50acf..5b95b2dc21 100644
--- a/libethcore/Farm.h
+++ b/libethcore/Farm.h
@@ -135,17 +135,19 @@ class Farm: public FarmFace
 	 */
 	void stop()
 	{
-		Guard l(x_minerWork);
-		m_miners.clear();
-		m_isMining = false;
-
-		if (p_hashrateTimer) {
-			p_hashrateTimer->cancel();
+		{
+			Guard l(x_minerWork);
+			m_miners.clear();
+			m_isMining = false;
 		}
 
 		m_io_service.stop();
 		m_serviceThread.join();
-		p_hashrateTimer = nullptr;
+
+		if (p_hashrateTimer) {
+			p_hashrateTimer->cancel();
+			p_hashrateTimer = nullptr;
+		}
 	}
 
 	void collectHashRate()