terminate unwinding at call_stub

ddprof-lib/src/main/cpp/os.h

@@ -50,7 +50,6 @@ class JitWriteProtection {
     ~JitWriteProtection();
 };
 
-
 class OS {
   public:
     static const size_t page_size;
@@ -79,7 +78,8 @@ class OS {
     static bool isLinux();
 
     static SigAction installSignalHandler(int signo, SigAction action, SigHandler handler = NULL);
-    static SigAction replaceCrashHandler(SigAction action);
+    static SigAction replaceSigsegvHandler(SigAction action);
+    static SigAction replaceSigbusHandler(SigAction action);
     static bool sendSignalToThread(int thread_id, int signo);
 
     static void* safeAlloc(size_t size);

ddprof-lib/src/main/cpp/os_linux.cpp

@@ -244,7 +244,7 @@ SigAction OS::installSignalHandler(int signo, SigAction action, SigHandler handl
     return oldsa.sa_sigaction;
 }
 
-SigAction OS::replaceCrashHandler(SigAction action) {
+SigAction OS::replaceSigsegvHandler(SigAction action) {
     struct sigaction sa;
     sigaction(SIGSEGV, NULL, &sa);
     SigAction old_action = sa.sa_sigaction;
@@ -253,6 +253,15 @@ SigAction OS::replaceCrashHandler(SigAction action) {
     return old_action;
 }
 
+SigAction OS::replaceSigbusHandler(SigAction action) {
+    struct sigaction sa;
+    sigaction(SIGBUS, NULL, &sa);
+    SigAction old_action = sa.sa_sigaction;
+    sa.sa_sigaction = action;
+    sigaction(SIGBUS, &sa, NULL);
+    return old_action;
+}
+
 bool OS::sendSignalToThread(int thread_id, int signo) {
     return syscall(__NR_tgkill, processId(), thread_id, signo) == 0;
 }

ddprof-lib/src/main/cpp/os_macos.cpp

@@ -214,7 +214,16 @@ SigAction OS::installSignalHandler(int signo, SigAction action, SigHandler handl
     return oldsa.sa_sigaction;
 }
 
-SigAction OS::replaceCrashHandler(SigAction action) {
+SigAction OS::replaceSigsegvHandler(SigAction action) {
+    struct sigaction sa;
+    sigaction(SIGSEGV, NULL, &sa);
+    SigAction old_action = sa.sa_sigaction;
+    sa.sa_sigaction = action;
+    sigaction(SIGSEGV, &sa, NULL);
+    return old_action;
+}
+
+SigAction OS::replaceSigbusHandler(SigAction action) {
     struct sigaction sa;
     sigaction(SIGBUS, NULL, &sa);
     SigAction old_action = sa.sa_sigaction;

ddprof-lib/src/main/cpp/profiler.cpp

@@ -52,6 +52,7 @@ Profiler* const Profiler::_instance = new Profiler();
 
 static void (*orig_trapHandler)(int signo, siginfo_t* siginfo, void* ucontext);
 static void (*orig_segvHandler)(int signo, siginfo_t* siginfo, void* ucontext);
+static void (*orig_busHandler)(int signo, siginfo_t* siginfo, void* ucontext);
 
 static Engine noop_engine;
 static PerfEvents perf_events;
@@ -689,7 +690,7 @@ void Profiler::recordSample(void* ucontext, u64 counter, int tid, jint event_typ
         ASGCT_CallFrame *native_stop = frames + num_frames;
         num_frames += getNativeTrace(ucontext, native_stop, event_type, tid, &java_ctx, &truncated);
         if (_cstack == CSTACK_VM) {
-            num_frames += StackWalker::walkVM(ucontext, frames + num_frames, _max_stack_depth);
+            num_frames += StackWalker::walkVM(ucontext, frames + num_frames, _max_stack_depth, _call_stub_begin, _call_stub_end);
         } else if (event_type == BCI_CPU || event_type == BCI_WALL) {
             int java_frames = 0;
             {
@@ -841,6 +842,18 @@ void Profiler::trapHandler(int signo, siginfo_t* siginfo, void* ucontext) {
 }
 
 void Profiler::segvHandler(int signo, siginfo_t* siginfo, void* ucontext) {
+    if (!crashHandler(signo, siginfo, ucontext)) {
+        orig_segvHandler(signo, siginfo, ucontext);
+    }
+}
+
+void Profiler::busHandler(int signo, siginfo_t* siginfo, void* ucontext) {
+    if (!crashHandler(signo, siginfo, ucontext)) {
+        orig_busHandler(signo, siginfo, ucontext);
+    }
+}
+
+bool Profiler::crashHandler(int signo, siginfo_t* siginfo, void* ucontext) {
     StackFrame frame(ucontext);
     uintptr_t pc = frame.pc();
 
@@ -850,7 +863,7 @@ void Profiler::segvHandler(int signo, siginfo_t* siginfo, void* ucontext) {
         frame.pc() += length;
         frame.retval() = 0;
         Counters::increment(HANDLED_SIGSEGV_SAFEFETCH);
-        return;
+        return true;
     }
 
     length = SafeAccess::skipLoadArg(pc);
@@ -859,21 +872,21 @@ void Profiler::segvHandler(int signo, siginfo_t* siginfo, void* ucontext) {
         frame.pc() += length;
         frame.retval() = frame.arg1();
         Counters::increment(HANDLED_SIGSEGV_SAFEFETCH);
-        return;
+        return true;
     }
 
     StackWalker::checkFault();
 
     // Workaround for JDK-8313796. Setting cstack=dwarf also helps
     if (VMStructs::isInterpretedFrameValidFunc((const void*)pc) && frame.skipFaultInstruction()) {
-        return;
+        return true;
     }
 
     if (WX_MEMORY && Trap::isFaultInstruction(pc)) {
-        return;
+        return true;
     }
 
-    orig_segvHandler(signo, siginfo, ucontext);
+    return false;
 }
 
 void Profiler::setupSignalHandlers() {
@@ -883,7 +896,8 @@ void Profiler::setupSignalHandlers() {
     }
     if (VM::java_version() > 0) {
         // HotSpot and J9 tolerate interposed SIGSEGV/SIGBUS handler; other JVMs probably not
-        orig_segvHandler = OS::replaceCrashHandler(segvHandler);
+        orig_segvHandler = OS::replaceSigsegvHandler(segvHandler);
+        orig_busHandler = OS::replaceSigbusHandler(busHandler);
     }
 }
 

ddprof-lib/src/main/cpp/profiler.h

@@ -189,6 +189,8 @@ class Profiler {
     void lockAll();
     void unlockAll();
 
+    static bool crashHandler(int signo, siginfo_t* siginfo, void* ucontext);
+
     static Profiler* const _instance;
 
   public:
@@ -291,6 +293,7 @@ class Profiler {
     static void trapHandlerEntry(int signo, siginfo_t* siginfo, void* ucontext);
     void trapHandler(int signo, siginfo_t* siginfo, void* ucontext);
     static void segvHandler(int signo, siginfo_t* siginfo, void* ucontext);
+    static void busHandler(int signo, siginfo_t* siginfo, void* ucontext);
     static void setupSignalHandlers();
 
     static int registerThread(int tid);

ddprof-lib/src/main/cpp/stackWalker.cpp

@@ -217,7 +217,8 @@ int StackWalker::walkDwarf(void* ucontext, const void** callchain, int max_depth
     return depth;
 }
 
-int StackWalker::walkVM(void* ucontext, ASGCT_CallFrame* frames, int max_depth) {
+int StackWalker::walkVM(void* ucontext, ASGCT_CallFrame* frames, int max_depth,
+                        const void* _termination_frame_begin, const void* _termination_frame_end) {
     const void* pc;
     uintptr_t fp;
     uintptr_t sp;
@@ -257,6 +258,9 @@ int StackWalker::walkVM(void* ucontext, ASGCT_CallFrame* frames, int max_depth)
 
     // Walk until the bottom of the stack or until the first Java frame
     while (depth < max_depth) {
+        if (pc >= _termination_frame_begin && pc < _termination_frame_end) {
+            break;
+        }
         if (CodeHeap::contains(pc)) {
             NMethod* nm = CodeHeap::findNMethod(pc);
             if (nm == NULL) {

ddprof-lib/src/main/cpp/stackWalker.h

@@ -37,7 +37,7 @@ class StackWalker {
   public:
     static int walkFP(void* ucontext, const void** callchain, int max_depth, StackContext* java_ctx, bool *truncated);
     static int walkDwarf(void* ucontext, const void** callchain, int max_depth, StackContext* java_ctx, bool *truncated);
-    static int walkVM(void* ucontext, ASGCT_CallFrame* frames, int max_depth);
+    static int walkVM(void* ucontext, ASGCT_CallFrame* frames, int max_depth, const void* _termination_frame_begin, const void* _termination_frame_end);
 
     static void checkFault();
 };

ddprof-test/src/test/java/com/datadoghq/profiler/cpu/VMStructsBasedCpuTest.java

@@ -0,0 +1,53 @@
+package com.datadoghq.profiler.cpu;
+
+import com.datadoghq.profiler.AbstractProfilerTest;
+import com.datadoghq.profiler.Platform;
+import org.junit.jupiter.api.Test;
+import org.openjdk.jmc.common.item.IItem;
+import org.openjdk.jmc.common.item.IItemCollection;
+import org.openjdk.jmc.common.item.IItemIterable;
+import org.openjdk.jmc.common.item.IMemberAccessor;
+import org.openjdk.jmc.flightrecorder.jdk.JdkAttributes;
+
+import java.util.concurrent.ExecutionException;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+
+
+public class VMStructsBasedCpuTest extends AbstractProfilerTest {
+
+    private ProfiledCode profiledCode;
+
+    @Override
+    protected void before() {
+        profiledCode = new ProfiledCode(profiler);
+    }
+
+    @Test
+    public void test() throws ExecutionException, InterruptedException {
+        for (int i = 0, id = 1; i < 100; i++, id += 3) {
+            profiledCode.method1(id);
+        }
+        stopProfiler();
+        IItemCollection events = verifyEvents("datadog.ExecutionSample");
+        for (IItemIterable it : events) {
+            IMemberAccessor<String, IItem> stackTraceAccessor = JdkAttributes.STACK_TRACE_STRING.getAccessor(it.getType());
+            for (IItem item : it) {
+                String stacktrace = stackTraceAccessor.getMember(item);
+                assertFalse(stacktrace.contains("JavaCalls::call_virtual()"),
+                        "JavaCalls::call_virtual() (above call_stub) found in stack trace");
+                assertFalse(stacktrace.contains("call_stub()"),
+                        "call_stub() (sentinel value used to halt unwinding) found in stack trace");
+            }
+        }
+    }
+
+    @Override
+    protected String getProfilerCommand() {
+        return "cpu=10ms" + (vmstructsUnwinderSupported() ? ",cstack=vm" : "");
+    }
+
+    private boolean vmstructsUnwinderSupported() {
+        return !Platform.isJ9() && !Platform.isZing();
+    }
+}