8297763: Fix missing stub code expansion before align() in shared tra…

…mpolines

Reviewed-by: fyang, luhenry

src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp

@@ -52,7 +52,14 @@ static bool emit_shared_trampolines(CodeBuffer* cb, CodeBuffer::SharedTrampoline
   bool p_succeeded = true;
   auto emit = [&](address dest, const CodeBuffer::Offsets &offsets) {
     masm.set_code_section(cb->stubs());
-    masm.align(wordSize);
+    if (!is_aligned(masm.offset(), wordSize)) {
+      if (cb->stubs()->maybe_expand_to_ensure_remaining(NativeInstruction::instruction_size) && cb->blob() == NULL) {
+        ciEnv::current()->record_failure("CodeCache is full");
+        p_succeeded = false;
+        return p_succeeded;
+      }
+      masm.align(wordSize);
+    }
 
     LinkedListIterator<int> it(offsets.head());
     int offset = *it.next();

src/hotspot/cpu/riscv/codeBuffer_riscv.cpp

@@ -53,7 +53,14 @@ static bool emit_shared_trampolines(CodeBuffer* cb, CodeBuffer::SharedTrampoline
   bool p_succeeded = true;
   auto emit = [&](address dest, const CodeBuffer::Offsets &offsets) {
     masm.set_code_section(cb->stubs());
-    masm.align(wordSize, NativeCallTrampolineStub::data_offset);
+    if (!is_aligned(masm.offset() + NativeCallTrampolineStub::data_offset, wordSize)) {
+      if (cb->stubs()->maybe_expand_to_ensure_remaining(NativeInstruction::instruction_size) && cb->blob() == NULL) {
+        ciEnv::current()->record_failure("CodeCache is full");
+        p_succeeded = false;
+        return p_succeeded;
+      }
+      masm.align(wordSize, NativeCallTrampolineStub::data_offset);
+    }
 
     LinkedListIterator<int> it(offsets.head());
     int offset = *it.next();

src/hotspot/cpu/riscv/macroAssembler_riscv.cpp

@@ -3128,6 +3128,9 @@ address MacroAssembler::emit_trampoline_stub(int insts_call_instruction_offset,
     return NULL;  // CodeBuffer::expand failed
   }
 
+  // We are always 4-byte aligned here.
+  assert_alignment(pc());
+
   // Create a trampoline stub relocation which relates this trampoline stub
   // with the call instruction at insts_call_instruction_offset in the
   // instructions code-section.