8350182: [s390x] Relativize locals in interpreter frames

Reviewed-by: lucy, rrich

Author: offamitkumar

src/hotspot/cpu/s390/frame_s390.cpp

@@ -185,7 +185,8 @@ bool frame::is_interpreted_frame() const {
 
 void frame::interpreter_frame_set_locals(intptr_t* locs)  {
   assert(is_interpreted_frame(), "interpreted frame expected");
-  ijava_state_unchecked()->locals = (uint64_t)locs;
+  // set relativized locals
+  *addr_at(_z_ijava_idx(locals)) = (intptr_t) (locs - fp());
 }
 
 // sender_sp
@@ -340,7 +341,7 @@ bool frame::is_interpreted_frame_valid(JavaThread* thread) const {
   if (MetaspaceObj::is_valid(cp) == false) return false;
 
   // validate locals
-  address locals = (address)(ijava_state_unchecked()->locals);
+  address locals = (address)interpreter_frame_locals();
   return thread->is_in_stack_range_incl(locals, (address)fp());
 }
 

src/hotspot/cpu/s390/frame_s390.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2025, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2016, 2024 SAP SE. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -330,6 +330,10 @@
 #define _z_ijava_state_neg(_component) \
          (int) (-frame::z_ijava_state_size + offset_of(frame::z_ijava_state, _component))
 
+// Frame slot index relative to fp
+#define _z_ijava_idx(_component) \
+        (_z_ijava_state_neg(_component) >> LogBytesPerWord)
+
   // ENTRY_FRAME
 
   struct z_entry_frame_locals {

src/hotspot/cpu/s390/frame_s390.inline.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2025, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2016, 2024 SAP SE. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -180,7 +180,8 @@ inline intptr_t* frame::link_or_null() const {
 }
 
 inline intptr_t* frame::interpreter_frame_locals() const {
-  return (intptr_t*) (ijava_state()->locals);
+  intptr_t n = *addr_at(_z_ijava_idx(locals));
+  return &fp()[n]; // return relativized locals
 }
 
 inline intptr_t* frame::interpreter_frame_bcp_addr() const {

src/hotspot/cpu/s390/interp_masm_s390.cpp

@@ -104,7 +104,15 @@ void InterpreterMacroAssembler::dispatch_base(TosState state, address* table, bo
   }
   { Label OK;
     // check if the locals pointer in Z_locals is correct
-    z_cg(Z_locals, _z_ijava_state_neg(locals), Z_fp);
+
+    // _z_ijava_state_neg(locals)) is fp relativized, so we need to
+    // extract the pointer.
+
+    z_lg(Z_R1_scratch, Address(Z_fp, _z_ijava_state_neg(locals)));
+    z_sllg(Z_R1_scratch, Z_R1_scratch, Interpreter::logStackElementSize);
+    z_agr(Z_R1_scratch, Z_fp);
+
+    z_cgr(Z_locals, Z_R1_scratch);
     z_bre(OK);
     reentry = stop_chain_static(reentry, "invalid locals pointer Z_locals: " FILE_AND_LINE);
     bind(OK);
@@ -684,6 +692,8 @@ void InterpreterMacroAssembler::save_mdp(Register mdp) {
 void InterpreterMacroAssembler::restore_locals() {
   asm_assert_ijava_state_magic(Z_locals);
   z_lg(Z_locals, Address(Z_fp, _z_ijava_state_neg(locals)));
+  z_sllg(Z_locals, Z_locals, Interpreter::logStackElementSize);
+  z_agr(Z_locals, Z_fp);
 }
 
 void InterpreterMacroAssembler::get_method(Register reg) {

src/hotspot/cpu/s390/templateInterpreterGenerator_s390.cpp

@@ -1134,7 +1134,11 @@ void TemplateInterpreterGenerator::generate_fixed_frame(bool native_call) {
   __ z_agr(Z_locals, Z_esp);
   // z_ijava_state->locals - i*BytesPerWord points to i-th Java local (i starts at 0)
   // z_ijava_state->locals = Z_esp + parameter_count bytes
-  __ z_stg(Z_locals, _z_ijava_state_neg(locals), fp);
+
+  __ z_sgrk(Z_R0, Z_locals, fp); // Z_R0 = Z_locals - fp();
+  __ z_srlg(Z_R0, Z_R0, Interpreter::logStackElementSize);
+  // Store relativized Z_locals, see frame::interpreter_frame_locals().
+  __ z_stg(Z_R0, _z_ijava_state_neg(locals), fp);
 
   // z_ijava_state->oop_temp = nullptr;
   __ store_const(Address(fp, oop_tmp_offset), 0);