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src/hotspot/cpu/ppc/frame_ppc.cpp
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rev 51053 : JFR profiling for PPC64
* * *
PPC64: jfr profiling
*** 47,64 ****
}
#endif // ASSERT
bool frame::safe_for_sender(JavaThread *thread) {
bool safe = false;
! address cursp = (address)sp();
! address curfp = (address)fp();
! if ((cursp != NULL && curfp != NULL &&
! (cursp <= thread->stack_base() && cursp >= thread->stack_base() - thread->stack_size())) &&
! (curfp <= thread->stack_base() && curfp >= thread->stack_base() - thread->stack_size())) {
! safe = true;
}
! return safe;
}
bool frame::is_interpreted_frame() const {
return Interpreter::contains(pc());
}
--- 47,196 ----
}
#endif // ASSERT
bool frame::safe_for_sender(JavaThread *thread) {
bool safe = false;
! address sp = (address)_sp;
! address fp = (address)_fp;
! address unextended_sp = (address)_unextended_sp;
!
!
! // consider stack guards when trying to determine "safe" stack pointers
! static size_t stack_guard_size = os::uses_stack_guard_pages() ?
! JavaThread::stack_red_zone_size() + JavaThread::stack_yellow_zone_size() : 0;
! size_t usable_stack_size = thread->stack_size() - stack_guard_size;
!
! // sp must be within the usable part of the stack (not in guards)
! bool sp_safe = (sp < thread->stack_base()) &&
! (sp >= thread->stack_base() - usable_stack_size);
!
!
! if (!sp_safe) {
! return false;
! }
!
! // unextended sp must be within the stack and above or equal sp
! bool unextended_sp_safe = (unextended_sp < thread->stack_base()) && (unextended_sp >= sp);
!
! if (!unextended_sp_safe) {
! return false;
! }
!
! // an fp must be within the stack and above (but not equal) sp
! bool fp_safe = (fp <= thread->stack_base()) && (fp > sp) && ((fp - sp) >= (ijava_state_size + top_ijava_frame_abi_size));
!
! // We know sp/unextended_sp are safe only fp is questionable here
!
! // If the current frame is known to the code cache then we can attempt to
! // to construct the sender and do some validation of it. This goes a long way
! // toward eliminating issues when we get in frame construction code
!
! if (_cb != NULL ) {
! // First check if frame is complete and tester is reliable
! // Unfortunately we can only check frame complete for runtime stubs and nmethod
! // other generic buffer blobs are more problematic so we just assume they are
! // ok. adapter blobs never have a frame complete and are never ok.
! if (!_cb->is_frame_complete_at(_pc)) {
! if (_cb->is_compiled() || _cb->is_adapter_blob() || _cb->is_runtime_stub()) {
! return false;
! }
! }
!
! // Could just be some random pointer within the codeBlob
! if (!_cb->code_contains(_pc)) {
! return false;
! }
!
! // Entry frame checks
! if (is_entry_frame()) {
! // an entry frame must have a valid fp.
! return fp_safe && is_entry_frame_valid(thread);
! }
!
! if (is_interpreted_frame() && !fp_safe) {
! return false;
! }
!
! abi_minframe* sender_abi = (abi_minframe*) fp;
! intptr_t* sender_sp = (intptr_t*) fp;
! address sender_pc = (address) sender_abi->lr;;
!
! // We must always be able to find a recognizable pc
! CodeBlob* sender_blob = CodeCache::find_blob_unsafe(sender_pc);
! if (sender_pc == NULL || sender_blob == NULL) {
! return false;
! }
!
! // Could be a zombie method
! if (sender_blob->is_zombie() || sender_blob->is_unloaded()) {
! return false;
! }
!
! // It should be safe to construct the sender though it might not be valid
!
! frame sender(sender_sp, sender_pc);
!
! // Do we have a valid fp?
! address sender_fp = (address) sender.fp();
!
! // an fp must be within the stack and above (but not equal) current frame's _FP
!
! bool sender_fp_safe = (sender_fp <= thread->stack_base()) && (sender_fp > fp);
!
! if (!sender_fp_safe) {
! return false;
! }
!
! // If the potential sender is the interpreter then we can do some more checking
! if (Interpreter::contains(sender_pc)) {
! return sender.is_interpreted_frame_valid(thread);
! }
!
! // Could just be some random pointer within the codeBlob
! if (!sender.cb()->code_contains(sender_pc)) {
! return false;
! }
!
! // We should never be able to see an adapter if the current frame is something from code cache
! if (sender_blob->is_adapter_blob()) {
! return false;
! }
!
! if (sender.is_entry_frame()) {
! // Validate the JavaCallWrapper an entry frame must have
!
! address jcw = (address)sender.entry_frame_call_wrapper();
!
! bool jcw_safe = (jcw <= thread->stack_base()) && (jcw > sender_fp);
! return jcw_safe;
}
!
! // If the frame size is 0 something (or less) is bad because every nmethod has a non-zero frame size
! // because you must allocate window space
! if (sender_blob->frame_size() <= 0) {
! return false;
! }
!
! // Could put some more validation for the potential non-interpreted sender
! // frame we'd create by calling sender if I could think of any. Wait for next crash in forte...
!
! // One idea is seeing if the sender_pc we have is one that we'd expect to call to current cb
!
! // We've validated the potential sender that would be created
!
! return true;
!
! }
!
! // Must be native-compiled frame. Since sender will try and use fp to find
! // linkages it must be safe
!
! if (!fp_safe) return false;
!
! // could try and do some more potential verification of native frame if we could think of some...
!
! return true;
}
bool frame::is_interpreted_frame() const {
return Interpreter::contains(pc());
}
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