src/hotspot/os_cpu/linux_ppc/os_linux_ppc.cpp

rev 48405 : 8194258: PPC64 safepoint mechanism: Fix initialization on AIX and support SIGTRAP
Summary: Use mmap on AIX to allocate protected page. Use trap instructions for polling if UseSIGTRAP is enabled.
Reviewed-by:

@@ -44,10 +44,11 @@
 #include "runtime/interfaceSupport.hpp"
 #include "runtime/java.hpp"
 #include "runtime/javaCalls.hpp"
 #include "runtime/mutexLocker.hpp"
 #include "runtime/osThread.hpp"
+#include "runtime/safepointMechanism.hpp"
 #include "runtime/sharedRuntime.hpp"
 #include "runtime/stubRoutines.hpp"
 #include "runtime/thread.inline.hpp"
 #include "runtime/timer.hpp"
 #include "utilities/events.hpp"

@@ -380,22 +381,23 @@
           tty->print_cr("trap: zombie_not_entrant (%s)", (sig == SIGTRAP) ? "SIGTRAP" : "SIGILL");
         }
         stub = SharedRuntime::get_handle_wrong_method_stub();
       }
 
-      else if (sig == SIGSEGV &&
+      else if (sig == ((SafepointMechanism::uses_thread_local_poll() && USE_POLL_BIT_ONLY) ? SIGTRAP : SIGSEGV) &&
                // A linux-ppc64 kernel before 2.6.6 doesn't set si_addr on some segfaults
                // in 64bit mode (cf. http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.6),
                // especially when we try to read from the safepoint polling page. So the check
                //   (address)info->si_addr == os::get_standard_polling_page()
                // doesn't work for us. We use:
                ((NativeInstruction*)pc)->is_safepoint_poll() &&
                CodeCache::contains((void*) pc) &&
                ((cb = CodeCache::find_blob(pc)) != NULL) &&
                cb->is_compiled()) {
         if (TraceTraps) {
-          tty->print_cr("trap: safepoint_poll at " INTPTR_FORMAT " (SIGSEGV)", p2i(pc));
+          tty->print_cr("trap: safepoint_poll at " INTPTR_FORMAT " (%s)", p2i(pc),
+                        (SafepointMechanism::uses_thread_local_poll() && USE_POLL_BIT_ONLY) ? "SIGTRAP" : "SIGSEGV");
         }
         stub = SharedRuntime::get_poll_stub(pc);
       }
 
       // SIGTRAP-based ic miss check in compiled code.