src/hotspot/os_cpu/linux_aarch64/os_linux_aarch64.cpp

rev 53257 : Cherry-pick: 8213199: GC abstraction for Assembler::needs_explicit_null_check() plus Shenandoah parts

@@ -355,14 +355,19 @@
       os::Linux::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
       return 1;
     }
 #endif
 
-    // Handle ALL stack overflow variations here
-    if (sig == SIGSEGV) {
       address addr = (address) info->si_addr;
 
+    // Make sure the high order byte is sign extended, as it may be masked away by the hardware.
+    if ((uintptr_t(addr) & (uintptr_t(1) << 55)) != 0) {
+      addr = address(uintptr_t(addr) | (uintptr_t(0xFF) << 56));
+    }
+
+    // Handle ALL stack overflow variations here
+    if (sig == SIGSEGV) {
       // check if fault address is within thread stack
       if (thread->on_local_stack(addr)) {
         // stack overflow
         if (thread->in_stack_yellow_reserved_zone(addr)) {
           thread->disable_stack_yellow_reserved_zone();

@@ -454,11 +459,11 @@
           continuation_for_implicit_exception(thread,
                                               pc,
                                               SharedRuntime::
                                               IMPLICIT_DIVIDE_BY_ZERO);
       } else if (sig == SIGSEGV &&
-               !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
+                 MacroAssembler::uses_implicit_null_check((void*)addr)) {
           // Determination of interpreter/vtable stub/compiled code null exception
           stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
       }
     } else if (thread->thread_state() == _thread_in_vm &&
                sig == SIGBUS && /* info->si_code == BUS_OBJERR && */