8245986: AArch64: Provide information when hitting a HaltNode

Reviewed-by: adinn

src/hotspot/cpu/aarch64/aarch64.ad

@@ -15255,7 +15255,7 @@ instruct ShouldNotReachHere() %{
 
   ins_encode %{
     if (is_reachable()) {
-      __ dcps1(0xdead + 1);
+      __ stop(_halt_reason);
     }
   %}
 

src/hotspot/cpu/aarch64/macroAssembler_aarch64.cpp

@@ -60,12 +60,10 @@
 
 #ifdef PRODUCT
 #define BLOCK_COMMENT(str) /* nothing */
-#define STOP(error) stop(error)
 #else
 #define BLOCK_COMMENT(str) block_comment(str)
-#define STOP(error) block_comment(error); stop(error)
 #endif
-
+#define STOP(str) stop(str);
 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
 
 // Patch any kind of instruction; there may be several instructions.
@@ -2223,22 +2221,9 @@ void MacroAssembler::resolve_jobject(Register value, Register thread, Register t
 }
 
 void MacroAssembler::stop(const char* msg) {
-  address ip = pc();
-  pusha();
-  mov(c_rarg0, (address)msg);
-  mov(c_rarg1, (address)ip);
-  mov(c_rarg2, sp);
-  mov(c_rarg3, CAST_FROM_FN_PTR(address, MacroAssembler::debug64));
-  blr(c_rarg3);
-  hlt(0);
-}
-
-void MacroAssembler::warn(const char* msg) {
-  pusha();
-  mov(c_rarg0, (address)msg);
-  mov(lr, CAST_FROM_FN_PTR(address, warning));
-  blr(lr);
-  popa();
+  BLOCK_COMMENT(msg);
+  dcps1(0xdeae);
+  emit_int64((uintptr_t)msg);
 }
 
 void MacroAssembler::unimplemented(const char* what) {

src/hotspot/cpu/aarch64/macroAssembler_aarch64.hpp

@@ -980,9 +980,6 @@ public:
   // prints msg, dumps registers and stops execution
   void stop(const char* msg);
 
-  // prints msg and continues
-  void warn(const char* msg);
-
   static void debug64(char* msg, int64_t pc, int64_t regs[]);
 
   void untested()                                { stop("untested"); }

src/hotspot/cpu/aarch64/nativeInst_aarch64.cpp

@@ -462,6 +462,10 @@ void NativeIllegalInstruction::insert(address code_pos) {
   *(juint*)code_pos = 0xd4bbd5a1; // dcps1 #0xdead
 }
 
+bool NativeInstruction::is_stop() {
+  return uint_at(0) == 0xd4bbd5c1; // dcps1 #0xdeae
+}
+
 //-------------------------------------------------------------------
 
 // MT-safe inserting of a jump over a jump or a nop (used by

src/hotspot/cpu/aarch64/nativeInst_aarch64.hpp

@@ -76,6 +76,7 @@ class NativeInstruction {
   bool is_movz();
   bool is_movk();
   bool is_sigill_zombie_not_entrant();
+  bool is_stop();
 
  protected:
   address addr_at(int offset) const    { return address(this) + offset; }

src/hotspot/os_cpu/linux_aarch64/os_linux_aarch64.cpp

@@ -381,6 +381,21 @@ JVM_handle_linux_signal(int sig,
           }
           stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
         }
+      } else if (sig == SIGILL && nativeInstruction_at(pc)->is_stop()) {
+        // Pull a pointer to the error message out of the instruction
+        // stream.
+        const uint64_t *detail_msg_ptr
+          = (uint64_t*)(pc + NativeInstruction::instruction_size);
+        const char *detail_msg = (const char *)*detail_msg_ptr;
+        const char *msg = "stop";
+        if (TraceTraps) {
+          tty->print_cr("trap: %s: (SIGILL)", msg);
+        }
+
+        va_list detail_args;
+        VMError::report_and_die(INTERNAL_ERROR, msg, detail_msg, detail_args, thread,
+                                pc, info, ucVoid, NULL, 0, 0);
+        va_end(detail_args);
       }
       else
 
@@ -505,7 +520,7 @@ void os::print_context(outputStream *st, const void *context) {
   // point to garbage if entry point in an nmethod is corrupted. Leave
   // this at the end, and hope for the best.
   address pc = os::Linux::ucontext_get_pc(uc);
-  print_instructions(st, pc, sizeof(char));
+  print_instructions(st, pc, 4/*native instruction size*/);
   st->cr();
 }