8370176: Mixed mode jhsdb jstack cannot unwind call stack with -Xcomp

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/cdbg/CFrame.java

@@ -36,6 +36,11 @@ public interface CFrame {
   /** Returns null when no more frames on stack */
   public CFrame sender(ThreadProxy th);
 
+  /** Find sender frame with given FP and PC */
+  public default CFrame sender(ThreadProxy th, Address fp, Address pc) {
+    return sender(th);
+  }
+
   /** Get the program counter of this frame */
   public Address pc();
 

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/linux/aarch64/LinuxAARCH64CFrame.java

@@ -53,24 +53,36 @@ public Address localVariableBase() {
       return fp;
    }
 
+   @Override
    public CFrame sender(ThreadProxy thread) {
-      AARCH64ThreadContext context = (AARCH64ThreadContext) thread.getContext();
-      Address rsp = context.getRegisterAsAddress(AARCH64ThreadContext.SP);
+      return sender(thread, null, null);
+   }
 
-      if ((fp == null) || fp.lessThan(rsp)) {
-        return null;
+   @Override
+   public CFrame sender(ThreadProxy thread, Address nextFP, Address nextPC) {
+      // Check fp
+      // Skip if both nextFP and nextPC are given - do not need to load from fp.
+      if (nextFP == null && nextPC == null) {
+        if (fp == null) {
+          return null;
+        }
+
+        // Check alignment of fp
+        if (dbg.getAddressValue(fp) % (2 * ADDRESS_SIZE) != 0) {
+          return null;
+        }
       }
 
-      // Check alignment of fp
-      if (dbg.getAddressValue(fp) % (2 * ADDRESS_SIZE) != 0) {
+      if (nextFP == null) {
+        nextFP = fp.getAddressAt(0 * ADDRESS_SIZE);
+      }
+      if (nextFP == null) {
         return null;
       }
 
-      Address nextFP = fp.getAddressAt(0 * ADDRESS_SIZE);
-      if (nextFP == null || nextFP.lessThanOrEqual(fp)) {
-        return null;
+      if (nextPC == null) {
+        nextPC  = fp.getAddressAt(1 * ADDRESS_SIZE);
       }
-      Address nextPC  = fp.getAddressAt(1 * ADDRESS_SIZE);
       if (nextPC == null) {
         return null;
       }

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/linux/amd64/LinuxAMD64CFrame.java

@@ -96,19 +96,22 @@ private Address getNextPC(boolean useDwarf) {
    }
 
    private boolean isValidFrame(Address nextCFA, ThreadContext context) {
-     return (nextCFA != null) &&
-             !nextCFA.lessThan(context.getRegisterAsAddress(AMD64ThreadContext.RSP));
+     return nextCFA != null;
    }
 
-   private Address getNextCFA(DwarfParser nextDwarf, ThreadContext context) {
+   private Address getNextCFA(DwarfParser nextDwarf, ThreadContext context, Address senderFP) {
      Address nextCFA;
 
+     if (senderFP == null) {
+       senderFP = cfa.getAddressAt(0);  // RBP by default
+     }
+
      if (nextDwarf == null) { // Next frame is Java
-       nextCFA = (dwarf == null) ? cfa.getAddressAt(0) // Current frame is Java (Use RBP)
+       nextCFA = (dwarf == null) ? senderFP // Current frame is Java
                                  : cfa.getAddressAt(dwarf.getBasePointerOffsetFromCFA()); // Current frame is Native
      } else { // Next frame is Native
-       if (dwarf == null) { // Current frame is Java (Use RBP)
-         nextCFA = cfa.getAddressAt(0);
+       if (dwarf == null) { // Current frame is Java
+         nextCFA = senderFP;
        } else { // Current frame is Native
          int nextCFAReg = nextDwarf.getCFARegister();
          if (!dwarf.isBPOffsetAvailable() && // Use RBP as CFA
@@ -132,14 +135,19 @@ private Address getNextCFA(DwarfParser nextDwarf, ThreadContext context) {
    }
 
    @Override
-   public CFrame sender(ThreadProxy thread) {
+   public CFrame sender(ThreadProxy th) {
+     return sender(th, null, null);
+   }
+
+   @Override
+   public CFrame sender(ThreadProxy th, Address fp, Address pc) {
      if (finalFrame) {
        return null;
      }
 
-     ThreadContext context = thread.getContext();
+     ThreadContext context = th.getContext();
 
-     Address nextPC = getNextPC(dwarf != null);
+     Address nextPC = pc != null ? pc : getNextPC(dwarf != null);
      if (nextPC == null) {
        return null;
      }
@@ -165,7 +173,7 @@ public CFrame sender(ThreadProxy thread) {
        }
      }
 
-     Address nextCFA = getNextCFA(nextDwarf, context);
+     Address nextCFA = getNextCFA(nextDwarf, context, fp);
      return isValidFrame(nextCFA, context) ? new LinuxAMD64CFrame(dbg, nextCFA, nextPC, nextDwarf)
                                            : null;
    }

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/linux/riscv64/LinuxRISCV64CFrame.java

@@ -57,27 +57,40 @@ public Address localVariableBase() {
       return fp;
    }
 
+   @Override
    public CFrame sender(ThreadProxy thread) {
-      RISCV64ThreadContext context = (RISCV64ThreadContext) thread.getContext();
-      Address rsp = context.getRegisterAsAddress(RISCV64ThreadContext.SP);
+      return sender(thread, null, null);
+   }
 
-      if ((fp == null) || fp.lessThan(rsp)) {
-        return null;
+   @Override
+   public CFrame sender(ThreadProxy thread, Address nextFP, Address nextPC) {
+      // Check fp
+      // Skip if both nextFP and nextPC are given - do not need to load from fp.
+      if (nextFP == null && nextPC == null) {
+        if (fp == null) {
+          return null;
+        }
+
+        // Check alignment of fp
+        if (dbg.getAddressValue(fp) % (2 * ADDRESS_SIZE) != 0) {
+          return null;
+        }
       }
 
-      // Check alignment of fp
-      if (dbg.getAddressValue(fp) % (2 * ADDRESS_SIZE) != 0) {
+      if (nextFP == null) {
+        nextFP = fp.getAddressAt(C_FRAME_LINK_OFFSET * ADDRESS_SIZE);
+      }
+      if (nextFP == null) {
         return null;
       }
 
-      Address nextFP = fp.getAddressAt(C_FRAME_LINK_OFFSET * ADDRESS_SIZE);
-      if (nextFP == null || nextFP.lessThanOrEqual(fp)) {
-        return null;
+      if (nextPC == null) {
+        nextPC = fp.getAddressAt(C_FRAME_RETURN_ADDR_OFFSET * ADDRESS_SIZE);
       }
-      Address nextPC  = fp.getAddressAt(C_FRAME_RETURN_ADDR_OFFSET * ADDRESS_SIZE);
       if (nextPC == null) {
         return null;
       }
+
       return new LinuxRISCV64CFrame(dbg, nextFP, nextPC);
    }
 

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/tools/PStack.java

@@ -109,6 +109,8 @@ public void run(PrintStream out, Debugger dbg) {
                   jthread.printThreadInfoOn(out);
                }
                while (f != null) {
+                  Address senderFP = null;
+                  Address senderPC = null;
                   ClosestSymbol sym = f.closestSymbolToPC();
                   Address pc = f.pc();
                   out.print(pc + "\t");
@@ -125,13 +127,13 @@ public void run(PrintStream out, Debugger dbg) {
                      out.println();
                   } else {
                       // look for one or more java frames
-                      String[] names = null;
+                      JavaNameInfo nameInfo = null;
                       // check interpreter frame
                       Interpreter interp = VM.getVM().getInterpreter();
                       if (interp.contains(pc)) {
-                         names = getJavaNames(th, f.localVariableBase());
+                         nameInfo = getJavaNames(th, f.localVariableBase());
                          // print codelet name if we can't determine method
-                         if (names == null || names.length == 0) {
+                         if (nameInfo == null || nameInfo.names() == null || nameInfo.names().length == 0) {
                             out.print("<interpreter> ");
                             InterpreterCodelet ic = interp.getCodeletContaining(pc);
                             if (ic != null) {
@@ -154,9 +156,9 @@ public void run(PrintStream out, Debugger dbg) {
                                   }
                                   out.println(" (Native method)");
                                } else {
-                                  names = getJavaNames(th, f.localVariableBase());
+                                  nameInfo = getJavaNames(th, f.localVariableBase());
                                   // just print compiled code, if can't determine method
-                                  if (names == null || names.length == 0) {
+                                  if (nameInfo == null || nameInfo.names() == null || nameInfo.names().length == 0) {
                                     out.println("<Unknown compiled code>");
                                   }
                                }
@@ -168,17 +170,21 @@ public void run(PrintStream out, Debugger dbg) {
                          }
                       }
                       // print java frames, if any
-                      if (names != null && names.length != 0) {
-                         // print java frame(s)
-                         for (int i = 0; i < names.length; i++) {
-                             if (i > 0) {
-                                 out.print(fillerForAddress);
+                      if (nameInfo != null) {
+                         if (nameInfo.names() != null && nameInfo.names().length != 0) {
+                             // print java frame(s)
+                             for (int i = 0; i < nameInfo.names().length; i++) {
+                                 if (i > 0) {
+                                     out.print(fillerForAddress);
+                                 }
+                                 out.println(nameInfo.names()[i]);
                              }
-                             out.println(names[i]);
                          }
+                         senderFP = nameInfo.senderFP();
+                         senderPC = nameInfo.senderPC();
                       }
                   }
-                  f = f.sender(th);
+                  f = f.sender(th, senderFP, senderPC);
                }
             } catch (Exception exp) {
                exp.printStackTrace();
@@ -239,17 +245,22 @@ private void printUnknown(PrintStream out) {
       out.println("\t????????");
    }
 
-   private String[] getJavaNames(ThreadProxy th, Address fp) {
+   private static record JavaNameInfo(String[] names, Address senderFP, Address senderPC) {};
+
+   private JavaNameInfo getJavaNames(ThreadProxy th, Address fp) {
       if (fp == null) {
          return null;
       }
       JavaVFrame[] jvframes = jframeCache.get(th);
       if (jvframes == null) return null; // not a java thread
+
       List<String> names = new ArrayList<>(10);
+      JavaVFrame bottomJVFrame = null;
       for (int fCount = 0; fCount < jvframes.length; fCount++) {
          JavaVFrame vf = jvframes[fCount];
          Frame f = vf.getFrame();
          if (fp.equals(f.getFP())) {
+            bottomJVFrame = vf;
             StringBuilder sb = new StringBuilder();
             Method method = vf.getMethod();
             // a special char to identify java frames in output
@@ -280,8 +291,16 @@ private String[] getJavaNames(ThreadProxy th, Address fp) {
             names.add(sb.toString());
          }
       }
-      String[] res = names.toArray(new String[0]);
-      return res;
+
+      Address senderFP = null;
+      Address senderPC = null;
+      if (bottomJVFrame != null) {
+         Frame senderFrame = bottomJVFrame.getFrame().sender((RegisterMap)bottomJVFrame.getRegisterMap().clone());
+         senderFP = senderFrame.getFP();
+         senderPC = senderFrame.getPC();
+      }
+
+      return new JavaNameInfo(names.toArray(new String[0]), senderFP, senderPC);
    }
 
    public void setVerbose(boolean verbose) {