8256843: [PPC64] runtime/logging/RedefineClasses.java fails with assert: registers not saved on stack

Reviewed-by: mdoerr, lucy

Author: reinrich

src/hotspot/os_cpu/aix_ppc/os_aix_ppc.cpp

@@ -65,16 +65,7 @@
 # include <ucontext.h>
 
 address os::current_stack_pointer() {
-  address csp;
-
-#if !defined(USE_XLC_BUILTINS)
-  // inline assembly for `mr regno(csp), R1_SP':
-  __asm__ __volatile__ ("mr %0, 1":"=r"(csp):);
-#else
-  csp = (address) __builtin_frame_address(0);
-#endif
-
-  return csp;
+  return (address)__builtin_frame_address(0);
 }
 
 char* os::non_memory_address_word() {
@@ -159,13 +150,9 @@ frame os::get_sender_for_C_frame(frame* fr) {
 
 
 frame os::current_frame() {
-  intptr_t* csp = (intptr_t*) *((intptr_t*) os::current_stack_pointer());
-  // hack.
-  frame topframe(csp, (address)0x8);
-  // Return sender of sender of current topframe which hopefully
-  // both have pc != NULL.
-  frame tmp = os::get_sender_for_C_frame(&topframe);
-  return os::get_sender_for_C_frame(&tmp);
+  intptr_t* csp = *(intptr_t**) __builtin_frame_address(0);
+  frame topframe(csp, CAST_FROM_FN_PTR(address, os::current_frame));
+  return os::get_sender_for_C_frame(&topframe);
 }
 
 bool PosixSignals::pd_hotspot_signal_handler(int sig, siginfo_t* info,

src/hotspot/os_cpu/linux_ppc/os_linux_ppc.cpp

@@ -78,12 +78,7 @@
 
 
 address os::current_stack_pointer() {
-  intptr_t* csp;
-
-  // inline assembly `mr regno(csp), R1_SP':
-  __asm__ __volatile__ ("mr %0, 1":"=r"(csp):);
-
-  return (address) csp;
+  return (address)__builtin_frame_address(0);
 }
 
 char* os::non_memory_address_word() {
@@ -179,13 +174,9 @@ frame os::get_sender_for_C_frame(frame* fr) {
 
 
 frame os::current_frame() {
-  intptr_t* csp = (intptr_t*) *((intptr_t*) os::current_stack_pointer());
-  // hack.
-  frame topframe(csp, (address)0x8);
-  // Return sender of sender of current topframe which hopefully
-  // both have pc != NULL.
-  frame tmp = os::get_sender_for_C_frame(&topframe);
-  return os::get_sender_for_C_frame(&tmp);
+  intptr_t* csp = *(intptr_t**) __builtin_frame_address(0);
+  frame topframe(csp, CAST_FROM_FN_PTR(address, os::current_frame));
+  return os::get_sender_for_C_frame(&topframe);
 }
 
 bool PosixSignals::pd_hotspot_signal_handler(int sig, siginfo_t* info,

src/hotspot/share/utilities/nativeCallStack.cpp

@@ -36,7 +36,7 @@ NativeCallStack::NativeCallStack(int toSkip, bool fillStack) :
     // to call os::get_native_stack. A tail call is used if _NMT_NOINLINE_ is not defined
     // (which means this is not a slowdebug build), and we are on 64-bit (except Windows).
     // This is not necessarily a rule, but what has been obvserved to date.
-#if (defined(_NMT_NOINLINE_) || defined(_WINDOWS) || !defined(_LP64))
+#if (defined(_NMT_NOINLINE_) || defined(_WINDOWS) || !defined(_LP64) || defined(PPC64))
     // Not a tail call.
     toSkip++;
 #if (defined(_NMT_NOINLINE_) && defined(BSD) && defined(_LP64))