8026775: nsk/jvmti/RedefineClasses/StressRedefine crashes due to EXCEPTION_ACCESS_VIOLATION

Summary: Uncommon trap blob did not bang all the stack shadow pages
Reviewed-by: kvn, twisti, iveresov, jrose

src/cpu/sparc/vm/macroAssembler_sparc.cpp

@@ -3526,8 +3526,12 @@ void MacroAssembler::bang_stack_size(Register Rsize, Register Rtsp,
   delayed()->sub(Rtsp, Roffset, Rtsp);
 
   // Bang down shadow pages too.
-  // The -1 because we already subtracted 1 page.
-  for (int i = 0; i< StackShadowPages-1; i++) {
+  // At this point, (tmp-0) is the last address touched, so don't
+  // touch it again.  (It was touched as (tmp-pagesize) but then tmp
+  // was post-decremented.)  Skip this address by starting at i=1, and
+  // touch a few more pages below.  N.B.  It is important to touch all
+  // the way down to and including i=StackShadowPages.
+  for (int i = 1; i <= StackShadowPages; i++) {
     set((-i*offset)+STACK_BIAS, Rscratch);
     st(G0, Rtsp, Rscratch);
   }

src/cpu/x86/vm/macroAssembler_x86.cpp

@@ -1381,8 +1381,12 @@ void MacroAssembler::bang_stack_size(Register size, Register tmp) {
   jcc(Assembler::greater, loop);
 
   // Bang down shadow pages too.
-  // The -1 because we already subtracted 1 page.
-  for (int i = 0; i< StackShadowPages-1; i++) {
+  // At this point, (tmp-0) is the last address touched, so don't
+  // touch it again.  (It was touched as (tmp-pagesize) but then tmp
+  // was post-decremented.)  Skip this address by starting at i=1, and
+  // touch a few more pages below.  N.B.  It is important to touch all
+  // the way down to and including i=StackShadowPages.
+  for (int i = 1; i <= StackShadowPages; i++) {
     // this could be any sized move but this is can be a debugging crumb
     // so the bigger the better.
     movptr(Address(tmp, (-i*os::vm_page_size())), size );

src/share/vm/asm/assembler.cpp

@@ -122,7 +122,7 @@ void AbstractAssembler::bind(Label& L) {
 void AbstractAssembler::generate_stack_overflow_check( int frame_size_in_bytes) {
   if (UseStackBanging) {
     // Each code entry causes one stack bang n pages down the stack where n
-    // is configurable by StackBangPages.  The setting depends on the maximum
+    // is configurable by StackShadowPages.  The setting depends on the maximum
     // depth of VM call stack or native before going back into java code,
     // since only java code can raise a stack overflow exception using the
     // stack banging mechanism.  The VM and native code does not detect stack