Backport 0737a5625269773dcf70b95f8b8ac90b3b6cc444

Author: duke

src/hotspot/cpu/riscv/riscv.ad

@@ -1184,6 +1184,8 @@ bool is_CAS(int opcode, bool maybe_volatile)
   }
 }
 
+constexpr uint64_t MAJIK_DWORD = 0xabbaabbaabbaabbaull;
+
 // predicate controlling translation of CAS
 //
 // returns true if CAS needs to use an acquiring load otherwise false
@@ -1363,10 +1365,15 @@ void MachPrologNode::format(PhaseRegAlloc *ra_, outputStream *st) const {
     st->print("# stack bang size=%d\n\t", framesize);
   }
 
-  st->print("sd  fp, [sp, #%d]\n\t", - 2 * wordSize);
-  st->print("sd  ra, [sp, #%d]\n\t", - wordSize);
-  if (PreserveFramePointer) { st->print("sub  fp, sp, #%d\n\t", 2 * wordSize); }
   st->print("sub sp, sp, #%d\n\t", framesize);
+  st->print("sd  fp, [sp, #%d]\n\t", framesize - 2 * wordSize);
+  st->print("sd  ra, [sp, #%d]\n\t", framesize - wordSize);
+  if (PreserveFramePointer) { st->print("add fp, sp, #%d\n\t", framesize); }
+
+  if (VerifyStackAtCalls) {
+    st->print("mv  t2, %ld\n\t", MAJIK_DWORD);
+    st->print("sd  t2, [sp, #%d]\n\t", framesize - 3 * wordSize);
+  }
 
   if (C->stub_function() == nullptr) {
     st->print("ld  t0, [guard]\n\t");
@@ -1416,6 +1423,11 @@ void MachPrologNode::emit(C2_MacroAssembler *masm, PhaseRegAlloc *ra_) const {
 
   __ build_frame(framesize);
 
+  if (VerifyStackAtCalls) {
+    __ mv(t2, MAJIK_DWORD);
+    __ sd(t2, Address(sp, framesize - 3 * wordSize));
+  }
+
   if (C->stub_function() == nullptr) {
     BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
     // Dummy labels for just measuring the code size
@@ -1437,10 +1449,6 @@ void MachPrologNode::emit(C2_MacroAssembler *masm, PhaseRegAlloc *ra_) const {
     bs->nmethod_entry_barrier(masm, slow_path, continuation, guard);
   }
 
-  if (VerifyStackAtCalls) {
-    Unimplemented();
-  }
-
   C->output()->set_frame_complete(__ offset());
 
   if (C->has_mach_constant_base_node()) {
@@ -2430,7 +2438,13 @@ encode %{
   enc_class riscv_enc_call_epilog() %{
     if (VerifyStackAtCalls) {
       // Check that stack depth is unchanged: find majik cookie on stack
-      __ call_Unimplemented();
+      int framesize = ra_->reg2offset_unchecked(OptoReg::add(ra_->_matcher._old_SP, -3 * VMRegImpl::slots_per_word));
+      Label stack_ok;
+      __ ld(t1, Address(sp, framesize));
+      __ mv(t2, MAJIK_DWORD);
+      __ beq(t2, t1, stack_ok);
+      __ stop("MAJIK_DWORD not found");
+      __ bind(stack_ok);
     }
   %}
 

src/hotspot/cpu/riscv/sharedRuntime_riscv.cpp

@@ -2486,7 +2486,7 @@ void SharedRuntime::generate_deopt_blob() {
 // EPILOG must remove this many slots.
 // RISCV needs two words for RA (return address) and FP (frame pointer).
 uint SharedRuntime::in_preserve_stack_slots() {
-  return 2 * VMRegImpl::slots_per_word;
+  return 2 * VMRegImpl::slots_per_word + (VerifyStackAtCalls ? 0 : 2) ;
 }
 
 uint SharedRuntime::out_preserve_stack_slots() {

src/hotspot/share/opto/chaitin.cpp

@@ -2375,7 +2375,7 @@ void PhaseChaitin::dump_frame() const {
         tty->print_cr("saved fp register");
       else if (return_addr == OptoReg::add(reg, 2*VMRegImpl::slots_per_word) &&
                VerifyStackAtCalls)
-        tty->print_cr("0xBADB100D   +VerifyStackAtCalls");
+        tty->print_cr("<Majik cookie>   +VerifyStackAtCalls");
       else
         tty->print_cr("in_preserve");
     } else if ((int)OptoReg::reg2stack(reg) < fixed_slots) {