From d0111efeada9f21db085e0cc27abd94d408ddaa9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Duval?= <jerome.duval@gmail.com>
Date: Mon, 17 Dec 2018 17:19:34 +0100
Subject: [PATCH] runtime_loader: Add missing locking around resizing the TLS
 DTV.
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* Fixes crashes when the DTV is concurrently resized by multiple threads.
* Fixes JVM crash or endless loop when building OpenJDK.
* Should help with #13154, #14129, #14304, #14342.

Change-Id: I132600315d76a1a86236c6c70db09a3cdf0a8743
Reviewed-on: https://review.haiku-os.org/771
Reviewed-by: Stephan Aßmus <superstippi@gmx.de>
---
 src/system/runtime_loader/elf_tls.cpp | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/system/runtime_loader/elf_tls.cpp b/src/system/runtime_loader/elf_tls.cpp
index f534cecc00..251467c70d 100644
--- a/src/system/runtime_loader/elf_tls.cpp
+++ b/src/system/runtime_loader/elf_tls.cpp
@@ -12,9 +12,14 @@
 
 #include <tls.h>
 
+#include <locks.h>
 #include <util/kernel_cpp.h>
 
 
+static const char* const kLockName = "runtime loader tls";
+static mutex sLock = MUTEX_INITIALIZER(kLockName);
+
+
 class TLSBlock {
 public:	
 	inline				TLSBlock();
@@ -280,6 +285,13 @@ DynamicThreadVector::_ResizeVector(unsigned minimumSize)
 	if (size <= oldSize)
 		return B_OK;
 
+	MutexLocker _(sLock);
+
+	// If the size has changed in the meantime, we're done.
+	oldSize = _Size();
+	if (size <= oldSize)
+		return B_OK;
+
 	void* newVector = realloc(*fVector, (size + 1) * sizeof(TLSBlock));
 	if (newVector == NULL)
 		return B_NO_MEMORY;