lock user-mode and semantic-bugs

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diff --git a/results/classifier/user-mode-bugs/1836558 b/results/classifier/user-mode-bugs/1836558
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+
+
+Qemu-ppc Memory leak creating threads
+
+When creating c++ threads (with c++ std::thread), the resulting binary has memory leaks when running with qemu-ppc.
+
+Eg the following c++ program, when compiled with gcc, consumes more and more memory while running at qemu-ppc. (does not have memory leaks when compiling for Intel, when running same binary on real powerpc CPU hardware also no memory leaks).
+
+(Note I used function getCurrentRSS to show available memory, see https://stackoverflow.com/questions/669438/how-to-get-memory-usage-at-runtime-using-c; calls commented out here)
+
+Compiler: powerpc-linux-gnu-g++ (Debian 8.3.0-2) 8.3.0 (but same problem with older g++ compilers even 4.9)
+Os: Debian 10.0 ( Buster) (but same problem seen on Debian 9/stetch)
+qemu: qemu-ppc version 3.1.50
+
+
+
+---
+
+#include <iostream>
+#include <thread>
+#include <chrono>
+
+
+using namespace std::chrono_literals;
+
+// Create/run and join a 100 threads.
+void Fun100()
+{
+//    auto b4 = getCurrentRSS();
+//    std::cout << getCurrentRSS() << std::endl;
+    for(int n = 0; n < 100; n++)
+    {
+        std::thread t([]
+        {
+            std::this_thread::sleep_for( 10ms );
+        });
+//        std::cout << n << ' ' << getCurrentRSS() << std::endl;
+        t.join();
+    }
+    std::this_thread::sleep_for( 500ms ); // to give OS some time to wipe memory...
+//    auto after = getCurrentRSS();
+    std::cout << b4 << ' ' << after << std::endl;
+}
+
+
+int main(int, char **)
+{
+    Fun100();
+    Fun100();  // memory used keeps increasing
+}
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