8302158: PPC: test/jdk/jdk/internal/vm/Continuation/Fuzz.java: Assert…

…ionError: res: false shouldPin: false

Reviewed-by: goetz, mdoerr

src/hotspot/cpu/ppc/frame_ppc.cpp

@@ -421,8 +421,12 @@ void frame::describe_pd(FrameValues& values, int frame_no) {
 #endif
 
 intptr_t *frame::initial_deoptimization_info() {
-  // unused... but returns fp() to minimize changes introduced by 7087445
-  return fp();
+  // `this` is the caller of the deoptee. We want to trim it, if compiled, to
+  // unextended_sp. This is necessary if the deoptee frame is the bottom frame
+  // of a continuation on stack (more frames could be in a StackChunk) as it
+  // will pop its stack args. Otherwise the recursion in
+  // FreezeBase::recurse_freeze_java_frame() would not stop at the bottom frame.
+  return is_compiled_frame() ? unextended_sp() : sp();
 }
 
 #ifndef PRODUCT

src/hotspot/cpu/ppc/sharedRuntime_ppc.cpp

@@ -3092,6 +3092,13 @@ void SharedRuntime::generate_deopt_blob() {
 
   // stack: (caller_of_deoptee, ...).
 
+  // Freezing continuation frames requires that the caller is trimmed to unextended sp if compiled.
+  // If not compiled the loaded value is equal to the current SP (see frame::initial_deoptimization_info())
+  // and the frame is effectively not resized.
+  Register caller_sp = R23_tmp3;
+  __ ld_ptr(caller_sp, Deoptimization::UnrollBlock::initial_info_offset_in_bytes(), unroll_block_reg);
+  __ resize_frame_absolute(caller_sp, R24_tmp4, R25_tmp5);
+
   // Loop through the `UnrollBlock' info and create interpreter frames.
   push_skeleton_frames(masm, true/*deopt*/,
                        unroll_block_reg,
@@ -3227,6 +3234,13 @@ void SharedRuntime::generate_uncommon_trap_blob() {
   __ asm_assert_eq("SharedRuntime::generate_deopt_blob: expected Unpack_uncommon_trap");
 #endif
 
+  // Freezing continuation frames requires that the caller is trimmed to unextended sp if compiled.
+  // If not compiled the loaded value is equal to the current SP (see frame::initial_deoptimization_info())
+  // and the frame is effectively not resized.
+  Register caller_sp = R23_tmp3;
+  __ ld_ptr(caller_sp, Deoptimization::UnrollBlock::initial_info_offset_in_bytes(), unroll_block_reg);
+  __ resize_frame_absolute(caller_sp, R24_tmp4, R25_tmp5);
+
   // Allocate new interpreter frame(s) and possibly a c2i adapter
   // frame.
   push_skeleton_frames(masm, false/*deopt*/,