RFR 8191278: MappedByteBuffer bulk access memory failures are not handled gracefully

[Jamsheed]

Hi Nick,

i think release and fastdebug should crash

basically because, atomic_copy64 get inlined, and get generated as post 
increment, on sigbus, from doesn't get incremented and it loop forever 
and crash.

Best regards,

Jamsheed

[1]

void _Copy_conjoint_jlongs_atomic(jlong* from, jlong* to, size_t count) {
     if (from > to) {
       jlong *end = from + count;
       while (from < end)
         os::atomic_copy64(from++, to++);
     }
     else if (from < to) {
       jlong *end = from;
       from += count - 1;
       to   += count - 1;
       while (from >= end)
         os::atomic_copy64(from--, to--);
     }
   }

   static void atomic_copy64(const volatile void *src, volatile void 
*dst) {
       *(jlong *) dst = *(const jlong *) src;
    }


On 11/04/19 3:33 PM, Nick Gasson wrote:
> Does the segfault only happen on release builds? I tried webrev.04 
> again on an AArch64 system with release, fastdebug, and slowdebug but 
> I still don't see this crash :-/.