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changeset 2966:a218d3f3a16f

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Add HotSpot backports for 3.17.0 to the alternate Hotspot builds for Shenandoah & AArch32. 2020-10-19 Andrew John Hughes <gnu_andrew@member.fsf.org> Add HotSpot backports for 3.17.0 to the alternate Hotspot builds for Shenandoah & AArch32. * Makefile.am: (ICEDTEA_PATCHES): Add new patches. * NEWS: Updated. * patches/hotspot/aarch32/8152358-pr3800.patch, * patches/hotspot/aarch32/pr3798.patch: Link to Shenandoah versions. * patches/hotspot/shenandoah/8152358-pr3800.patch: Improve debugging output. * patches/hotspot/shenandoah/8251120-pr3793.patch: Add changeset header. * patches/hotspot/shenandoah/pr3798.patch: Fix format overflow warning from GCC 10.
author Andrew John Hughes <gnu_andrew@member.fsf.org>
date Mon, 19 Oct 2020 16:56:16 +0100
parents 442218c88539
children 7e0780d57319
files ChangeLog Makefile.am NEWS patches/hotspot/aarch32/8152358-pr3800.patch patches/hotspot/aarch32/pr3798.patch patches/hotspot/shenandoah/8152358-pr3800.patch patches/hotspot/shenandoah/8251120-pr3793.patch patches/hotspot/shenandoah/pr3798.patch
diffstat 8 files changed, 365 insertions(+), 3 deletions(-) [+]
line wrap: on
line diff
--- a/ChangeLog	Mon Aug 31 03:15:02 2020 +0100
+++ b/ChangeLog	Mon Oct 19 16:56:16 2020 +0100
@@ -1,3 +1,20 @@
+2020-10-19  Andrew John Hughes  <gnu_andrew@member.fsf.org>
+
+	Add HotSpot backports for 3.17.0 to the alternate
+	Hotspot builds for Shenandoah & AArch32.
+	* Makefile.am:
+	(ICEDTEA_PATCHES): Add new patches.
+	* NEWS: Updated.
+	* patches/hotspot/aarch32/8152358-pr3800.patch,
+	* patches/hotspot/aarch32/pr3798.patch:
+	Link to Shenandoah versions.
+	* patches/hotspot/shenandoah/8152358-pr3800.patch:
+	Improve debugging output.
+	* patches/hotspot/shenandoah/8251120-pr3793.patch:
+	Add changeset header.
+	* patches/hotspot/shenandoah/pr3798.patch:
+	Fix format overflow warning from GCC 10.
+
 2020-08-23  Andrew John Hughes  <gnu_andrew@member.fsf.org>
 
 	Bump to icedtea-3.17.0pre01.
--- a/Makefile.am	Mon Aug 31 03:15:02 2020 +0100
+++ b/Makefile.am	Mon Oct 19 16:56:16 2020 +0100
@@ -381,7 +381,9 @@
 	patches/hotspot/$(HSBUILD)/8076475-pr3696.patch \
 	patches/hotspot/$(HSBUILD)/pr3728.patch \
 	patches/hotspot/$(HSBUILD)/8222286-pr3727-s390.patch \
-	patches/hotspot/$(HSBUILD)/8251120-pr3793.patch
+	patches/hotspot/$(HSBUILD)/8251120-pr3793.patch \
+	patches/hotspot/$(HSBUILD)/8152358-pr3800.patch \
+	patches/hotspot/$(HSBUILD)/pr3798.patch
 
 # Shenandoah has the AArch64 port so should get the return value & debug build fixes
 # Shenandoah also needs some fixes to build on all architectures
--- a/NEWS	Mon Aug 31 03:15:02 2020 +0100
+++ b/NEWS	Mon Oct 19 16:56:16 2020 +0100
@@ -121,10 +121,16 @@
   - JDK-8238380, PR3798: java.base/unix/native/libjava/childproc.c "multiple definition" link errors with GCC10
   - JDK-8238386, PR3798: (sctp) jdk.sctp/unix/native/libsctp/SctpNet.c "multiple definition" link errors with GCC10
   - JDK-8238388, PR3798: libj2gss/NativeFunc.o "multiple definition" link errors with GCC10
+* Shenandoah
+  - JDK-8152358, PR3800: code and comment cleanups found during the hunt for 8077392
+  - PR3798: Fix format-overflow error on GCC 10, caused by passing NULL to a '%s' directive
 * AArch64 port
   - JDK-8183925, PR3797: [AArch64] Decouple crash protection from watcher thread
   - JDK-8199712, PR3797: [AArch64] Flight Recorder
   - JDK-8215961, PR3797: jdk/jfr/event/os/TestCPUInformation.java fails on AArch64
+* AArch32 port
+  - JDK-8152358, PR3800: code and comment cleanups found during the hunt for 8077392
+  - PR3798: Fix format-overflow error on GCC 10, caused by passing NULL to a '%s' directive
 
 New in release 3.16.0 (2020-05-02):
 
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/patches/hotspot/aarch32/8152358-pr3800.patch	Mon Oct 19 16:56:16 2020 +0100
@@ -0,0 +1,1 @@
+../shenandoah/8152358-pr3800.patch
\ No newline at end of file
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/patches/hotspot/aarch32/pr3798.patch	Mon Oct 19 16:56:16 2020 +0100
@@ -0,0 +1,1 @@
+../shenandoah/pr3798.patch
\ No newline at end of file
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/patches/hotspot/shenandoah/8152358-pr3800.patch	Mon Oct 19 16:56:16 2020 +0100
@@ -0,0 +1,281 @@
+# HG changeset patch
+# User Andrew John Hughes <gnu_andrew@member.fsf.org>
+# Date 1599349088 -3600
+#      Sun Sep 06 00:38:08 2020 +0100
+# Node ID b73ff161ed0a57a46fdb3ed51291e39c67d880f5
+# Parent  412a170785df4e95fef3622d66910b90ad2245c8
+8152358, PR3800: code and comment cleanups found during the hunt for 8077392
+
+diff --git openjdk.orig/hotspot/src/cpu/x86/vm/c1_LIRAssembler_x86.cpp openjdk/hotspot/src/cpu/x86/vm/c1_LIRAssembler_x86.cpp
+--- openjdk.orig/hotspot/src/cpu/x86/vm/c1_LIRAssembler_x86.cpp
++++ openjdk/hotspot/src/cpu/x86/vm/c1_LIRAssembler_x86.cpp
+@@ -1,5 +1,5 @@
+ /*
+- * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
++ * Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
+  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+  *
+  * This code is free software; you can redistribute it and/or modify it
+@@ -312,7 +312,7 @@
+   Register OSR_buf = osrBufferPointer()->as_pointer_register();
+   { assert(frame::interpreter_frame_monitor_size() == BasicObjectLock::size(), "adjust code below");
+     int monitor_offset = BytesPerWord * method()->max_locals() +
+-      (2 * BytesPerWord) * (number_of_locks - 1);
++      (BasicObjectLock::size() * BytesPerWord) * (number_of_locks - 1);
+     // SharedRuntime::OSR_migration_begin() packs BasicObjectLocks in
+     // the OSR buffer using 2 word entries: first the lock and then
+     // the oop.
+diff --git openjdk.orig/hotspot/src/cpu/x86/vm/interp_masm_x86_32.cpp openjdk/hotspot/src/cpu/x86/vm/interp_masm_x86_32.cpp
+--- openjdk.orig/hotspot/src/cpu/x86/vm/interp_masm_x86_32.cpp
++++ openjdk/hotspot/src/cpu/x86/vm/interp_masm_x86_32.cpp
+@@ -722,7 +722,7 @@
+     // Save (object->mark() | 1) into BasicLock's displaced header
+     movptr(Address(lock_reg, mark_offset), swap_reg);
+ 
+-    assert(lock_offset == 0, "displached header must be first word in BasicObjectLock");
++    assert(lock_offset == 0, "displaced header must be first word in BasicObjectLock");
+     if (os::is_MP()) {
+       lock();
+     }
+@@ -811,7 +811,7 @@
+     if (os::is_MP()) lock();
+     cmpxchgptr(header_reg, Address(obj_reg, 0));
+ 
+-    // zero for recursive case
++    // zero for simple unlock of a stack-lock case
+     jcc(Assembler::zero, done);
+ 
+     // Call the runtime routine for slow case.
+diff --git openjdk.orig/hotspot/src/cpu/x86/vm/interp_masm_x86_64.cpp openjdk/hotspot/src/cpu/x86/vm/interp_masm_x86_64.cpp
+--- openjdk.orig/hotspot/src/cpu/x86/vm/interp_masm_x86_64.cpp
++++ openjdk/hotspot/src/cpu/x86/vm/interp_masm_x86_64.cpp
+@@ -725,7 +725,7 @@
+     movptr(Address(lock_reg, mark_offset), swap_reg);
+ 
+     assert(lock_offset == 0,
+-           "displached header must be first word in BasicObjectLock");
++           "displaced header must be first word in BasicObjectLock");
+ 
+     if (os::is_MP()) lock();
+     cmpxchgptr(lock_reg, Address(obj_reg, 0));
+@@ -778,7 +778,7 @@
+ // Kills:
+ //      rax
+ //      c_rarg0, c_rarg1, c_rarg2, c_rarg3, ... (param regs)
+-//      rscratch1, rscratch2 (scratch regs)
++//      rscratch1 (scratch reg)
+ void InterpreterMacroAssembler::unlock_object(Register lock_reg) {
+   assert(lock_reg == c_rarg1, "The argument is only for looks. It must be rarg1");
+ 
+@@ -823,7 +823,7 @@
+     if (os::is_MP()) lock();
+     cmpxchgptr(header_reg, Address(obj_reg, 0));
+ 
+-    // zero for recursive case
++    // zero for simple unlock of a stack-lock case
+     jcc(Assembler::zero, done);
+ 
+     // Call the runtime routine for slow case.
+diff --git openjdk.orig/hotspot/src/cpu/x86/vm/macroAssembler_x86.cpp openjdk/hotspot/src/cpu/x86/vm/macroAssembler_x86.cpp
+--- openjdk.orig/hotspot/src/cpu/x86/vm/macroAssembler_x86.cpp
++++ openjdk/hotspot/src/cpu/x86/vm/macroAssembler_x86.cpp
+@@ -1078,7 +1078,7 @@
+   }
+   assert(markOopDesc::age_shift == markOopDesc::lock_bits + markOopDesc::biased_lock_bits, "biased locking makes assumptions about bit layout");
+   Address mark_addr      (obj_reg, oopDesc::mark_offset_in_bytes());
+-  Address saved_mark_addr(lock_reg, 0);
++  NOT_LP64( Address saved_mark_addr(lock_reg, 0); )
+ 
+   if (PrintBiasedLockingStatistics && counters == NULL) {
+     counters = BiasedLocking::counters();
+@@ -1699,7 +1699,7 @@
+                                RTMLockingCounters* stack_rtm_counters,
+                                Metadata* method_data,
+                                bool use_rtm, bool profile_rtm) {
+-  // Ensure the register assignents are disjoint
++  // Ensure the register assignments are disjoint
+   assert(tmpReg == rax, "");
+ 
+   if (use_rtm) {
+diff --git openjdk.orig/hotspot/src/share/vm/runtime/biasedLocking.cpp openjdk/hotspot/src/share/vm/runtime/biasedLocking.cpp
+--- openjdk.orig/hotspot/src/share/vm/runtime/biasedLocking.cpp
++++ openjdk/hotspot/src/share/vm/runtime/biasedLocking.cpp
+@@ -151,8 +151,13 @@
+   if (!mark->has_bias_pattern()) {
+     if (TraceBiasedLocking) {
+       ResourceMark rm;
+-      tty->print_cr("  (Skipping revocation of object of type %s because it's no longer biased)",
+-                    obj->klass()->external_name());
++      tty->print_cr("  (Skipping revocation of object " INTPTR_FORMAT
++                    ", mark " INTPTR_FORMAT ", type %s"
++                    ", requesting thread " INTPTR_FORMAT
++                    " because it's no longer biased)",
++                    p2i((void *)obj), (intptr_t) mark,
++                    obj->klass()->external_name(),
++                    (intptr_t) requesting_thread);
+     }
+     return BiasedLocking::NOT_BIASED;
+   }
+@@ -163,8 +168,15 @@
+ 
+   if (TraceBiasedLocking && (Verbose || !is_bulk)) {
+     ResourceMark rm;
+-    tty->print_cr("Revoking bias of object " INTPTR_FORMAT " , mark " INTPTR_FORMAT " , type %s , prototype header " INTPTR_FORMAT " , allow rebias %d , requesting thread " INTPTR_FORMAT,
+-                  p2i((void *)obj), (intptr_t) mark, obj->klass()->external_name(), (intptr_t) obj->klass()->prototype_header(), (allow_rebias ? 1 : 0), (intptr_t) requesting_thread);
++    tty->print_cr("Revoking bias of object " INTPTR_FORMAT ", mark "
++                  INTPTR_FORMAT ", type %s, prototype header " INTPTR_FORMAT
++                  ", allow rebias %d, requesting thread " INTPTR_FORMAT,
++                  p2i((void *)obj),
++                  (intptr_t) mark,
++                  obj->klass()->external_name(),
++                  (intptr_t) obj->klass()->prototype_header(),
++                  (allow_rebias ? 1 : 0),
++                  (intptr_t) requesting_thread);
+   }
+ 
+   JavaThread* biased_thread = mark->biased_locker();
+@@ -200,11 +212,17 @@
+       obj->set_mark(unbiased_prototype);
+     }
+     if (TraceBiasedLocking && (Verbose || !is_bulk)) {
+-      tty->print_cr("  Revoked bias of object biased toward dead thread");
++      tty->print_cr("  Revoked bias of object biased toward dead thread ("
++                              PTR_FORMAT ")", p2i(biased_thread));
+     }
+     return BiasedLocking::BIAS_REVOKED;
+   }
+ 
++  if (TraceBiasedLocking && (Verbose || !is_bulk)) {
++    tty->print_cr("  Revoked bias of object biased toward live thread ("
++                  PTR_FORMAT ")", p2i(biased_thread));
++  }
++
+   // Thread owning bias is alive.
+   // Check to see whether it currently owns the lock and, if so,
+   // write down the needed displaced headers to the thread's stack.
+diff --git openjdk.orig/hotspot/src/share/vm/runtime/objectMonitor.cpp openjdk/hotspot/src/share/vm/runtime/objectMonitor.cpp
+--- openjdk.orig/hotspot/src/share/vm/runtime/objectMonitor.cpp
++++ openjdk/hotspot/src/share/vm/runtime/objectMonitor.cpp
+@@ -929,7 +929,7 @@
+ // ~~~~~~~~
+ // ::exit() uses a canonical 1-1 idiom with a MEMBAR although some of
+ // the fast-path operators have been optimized so the common ::exit()
+-// operation is 1-0.  See i486.ad fast_unlock(), for instance.
++// operation is 1-0, e.g., see macroAssembler_x86.cpp: fast_unlock().
+ // The code emitted by fast_unlock() elides the usual MEMBAR.  This
+ // greatly improves latency -- MEMBAR and CAS having considerable local
+ // latency on modern processors -- but at the cost of "stranding".  Absent the
+@@ -942,7 +942,7 @@
+ //
+ // The CAS() in enter provides for safety and exclusion, while the CAS or
+ // MEMBAR in exit provides for progress and avoids stranding.  1-0 locking
+-// eliminates the CAS/MEMBAR from the exist path, but it admits stranding.
++// eliminates the CAS/MEMBAR from the exit path, but it admits stranding.
+ // We detect and recover from stranding with timers.
+ //
+ // If a thread transiently strands it'll park until (a) another
+diff --git openjdk.orig/hotspot/src/share/vm/runtime/os.cpp openjdk/hotspot/src/share/vm/runtime/os.cpp
+--- openjdk.orig/hotspot/src/share/vm/runtime/os.cpp
++++ openjdk/hotspot/src/share/vm/runtime/os.cpp
+@@ -1286,7 +1286,8 @@
+   // We initialize the serialization page shift count here
+   // We assume a cache line size of 64 bytes
+   assert(SerializePageShiftCount == count,
+-         "thread size changed, fix SerializePageShiftCount constant");
++         err_msg("JavaThread size changed; "
++                 "SerializePageShiftCount constant should be %d", count));
+   set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
+ }
+ 
+diff --git openjdk.orig/hotspot/src/share/vm/runtime/sharedRuntime.cpp openjdk/hotspot/src/share/vm/runtime/sharedRuntime.cpp
+--- openjdk.orig/hotspot/src/share/vm/runtime/sharedRuntime.cpp
++++ openjdk/hotspot/src/share/vm/runtime/sharedRuntime.cpp
+@@ -2957,7 +2957,7 @@
+   Method* moop = fr.interpreter_frame_method();
+   int max_locals = moop->max_locals();
+   // Allocate temp buffer, 1 word per local & 2 per active monitor
+-  int buf_size_words = max_locals + active_monitor_count*2;
++  int buf_size_words = max_locals + active_monitor_count * BasicObjectLock::size();
+   intptr_t *buf = NEW_C_HEAP_ARRAY(intptr_t,buf_size_words, mtCode);
+ 
+   // Copy the locals.  Order is preserved so that loading of longs works.
+diff --git openjdk.orig/hotspot/src/share/vm/runtime/synchronizer.cpp openjdk/hotspot/src/share/vm/runtime/synchronizer.cpp
+--- openjdk.orig/hotspot/src/share/vm/runtime/synchronizer.cpp
++++ openjdk/hotspot/src/share/vm/runtime/synchronizer.cpp
+@@ -184,38 +184,52 @@
+ }
+ 
+ void ObjectSynchronizer::fast_exit(oop object, BasicLock* lock, TRAPS) {
+-  assert(!object->mark()->has_bias_pattern(), "should not see bias pattern here");
+-  // if displaced header is null, the previous enter is recursive enter, no-op
++  markOop mark = object->mark();
++  // We cannot check for Biased Locking if we are racing an inflation.
++  assert(mark == markOopDesc::INFLATING() ||
++         !mark->has_bias_pattern(), "should not see bias pattern here");
++
+   markOop dhw = lock->displaced_header();
+-  markOop mark ;
+   if (dhw == NULL) {
+-     // Recursive stack-lock.
+-     // Diagnostics -- Could be: stack-locked, inflating, inflated.
+-     mark = object->mark() ;
+-     assert (!mark->is_neutral(), "invariant") ;
+-     if (mark->has_locker() && mark != markOopDesc::INFLATING()) {
+-        assert(THREAD->is_lock_owned((address)mark->locker()), "invariant") ;
++    // If the displaced header is NULL, then this exit matches up with
++    // a recursive enter. No real work to do here except for diagnostics.
++#ifndef PRODUCT
++    if (mark != markOopDesc::INFLATING()) {
++      // Only do diagnostics if we are not racing an inflation. Simply
++      // exiting a recursive enter of a Java Monitor that is being
++      // inflated is safe; see the has_monitor() comment below.
++      assert(!mark->is_neutral(), "invariant");
++      assert(!mark->has_locker() ||
++             THREAD->is_lock_owned((address)mark->locker()), "invariant");
++      if (mark->has_monitor()) {
++        // The BasicLock's displaced_header is marked as a recursive
++        // enter and we have an inflated Java Monitor (ObjectMonitor).
++        // This is a special case where the Java Monitor was inflated
++        // after this thread entered the stack-lock recursively. When a
++        // Java Monitor is inflated, we cannot safely walk the Java
++        // Monitor owner's stack and update the BasicLocks because a
++        // Java Monitor can be asynchronously inflated by a thread that
++        // does not own the Java Monitor.
++        ObjectMonitor * m = mark->monitor();
++        assert(((oop)(m->object()))->mark() == mark, "invariant");
++        assert(m->is_entered(THREAD), "invariant");
++      }
+      }
+-     if (mark->has_monitor()) {
+-        ObjectMonitor * m = mark->monitor() ;
+-        assert(((oop)(m->object()))->mark() == mark, "invariant") ;
+-        assert(m->is_entered(THREAD), "invariant") ;
+-     }
+-     return ;
++#endif
++     return;
+   }
+ 
+-  mark = object->mark() ;
+-
+-  // If the object is stack-locked by the current thread, try to
+-  // swing the displaced header from the box back to the mark.
+   if (mark == (markOop) lock) {
+-     assert (dhw->is_neutral(), "invariant") ;
+-     if ((markOop) Atomic::cmpxchg_ptr (dhw, object->mark_addr(), mark) == mark) {
+-        TEVENT (fast_exit: release stacklock) ;
+-        return;
+-     }
++    // If the object is stack-locked by the current thread, try to
++    // swing the displaced header from the BasicLock back to the mark.
++    assert (dhw->is_neutral(), "invariant") ;
++    if ((markOop) Atomic::cmpxchg_ptr(dhw, object->mark_addr(), mark) == mark) {
++      TEVENT(fast_exit: release stack-lock);
++      return;
++    }
+   }
+ 
++  // We have to take the slow-path of possible inflation and then exit.
+   ObjectSynchronizer::inflate(THREAD, object)->exit (true, THREAD) ;
+ }
+ 
--- a/patches/hotspot/shenandoah/8251120-pr3793.patch	Mon Aug 31 03:15:02 2020 +0100
+++ b/patches/hotspot/shenandoah/8251120-pr3793.patch	Mon Oct 19 16:56:16 2020 +0100
@@ -1,3 +1,13 @@
+# HG changeset patch
+# User andrew
+# Date 1598596701 -3600
+#      Fri Aug 28 07:38:21 2020 +0100
+# Node ID 7323b2187a50e3d04cdc3b0e35bac32875e34e09
+# Parent  b73ff161ed0a57a46fdb3ed51291e39c67d880f5
+8251120, PR3793: [8u] HotSpot build assumes ENABLE_JFR is set to either true or false
+Summary: Only test for ENABLE_JFR being true, and assume undefined == false
+Reviewed-by: neugens
+
 diff --git openjdk.orig/hotspot/make/aix/makefiles/buildtree.make openjdk/hotspot/make/aix/makefiles/buildtree.make
 --- openjdk.orig/hotspot/make/aix/makefiles/buildtree.make
 +++ openjdk/hotspot/make/aix/makefiles/buildtree.make
@@ -61,7 +71,7 @@
 diff --git openjdk.orig/hotspot/make/linux/makefiles/vm.make openjdk/hotspot/make/linux/makefiles/vm.make
 --- openjdk.orig/hotspot/make/linux/makefiles/vm.make
 +++ openjdk/hotspot/make/linux/makefiles/vm.make
-@@ -150,7 +150,7 @@
+@@ -158,7 +158,7 @@
  LIBJVM_DEBUGINFO   = lib$(JVM).debuginfo
  LIBJVM_DIZ         = lib$(JVM).diz
  
@@ -85,7 +95,7 @@
 diff --git openjdk.orig/hotspot/make/solaris/makefiles/vm.make openjdk/hotspot/make/solaris/makefiles/vm.make
 --- openjdk.orig/hotspot/make/solaris/makefiles/vm.make
 +++ openjdk/hotspot/make/solaris/makefiles/vm.make
-@@ -164,7 +164,7 @@
+@@ -172,7 +172,7 @@
  
  LIBJVM_DEBUGINFO   = lib$(JVM).debuginfo
  LIBJVM_DIZ         = lib$(JVM).diz
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/patches/hotspot/shenandoah/pr3798.patch	Mon Oct 19 16:56:16 2020 +0100
@@ -0,0 +1,44 @@
+# HG changeset patch
+# User Andrew John Hughes <gnu_andrew@member.fsf.org>
+# Date 1598841656 -3600
+#      Mon Aug 31 03:40:56 2020 +0100
+# Node ID 9f2ceb42dc64f72ae83997982383c30a454acdb2
+# Parent  3511db5b989804f5df37eda1dcefc28e44e964a6
+PR3798: Fix format-overflow error on GCC 10, caused by passing NULL to a '%s' directive
+
+diff --git openjdk.orig/hotspot/src/os/linux/vm/os_linux.cpp openjdk/hotspot/src/os/linux/vm/os_linux.cpp
+--- openjdk.orig/hotspot/src/os/linux/vm/os_linux.cpp
++++ openjdk/hotspot/src/os/linux/vm/os_linux.cpp
+@@ -4947,8 +4947,9 @@
+ static os_sigaction_t os_sigaction = NULL;
+ 
+ void os::Linux::check_signal_handler(int sig) {
+-  char buf[O_BUFLEN];
++  char buf[O_BUFLEN], enbuf[O_BUFLEN];
+   address jvmHandler = NULL;
++  const char* exname = os::exception_name(sig, enbuf, O_BUFLEN);
+ 
+ 
+   struct sigaction act;
+@@ -4999,7 +5000,7 @@
+   }
+ 
+   if (thisHandler != jvmHandler) {
+-    tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
++    tty->print("Warning: %s handler ", exname == NULL ? "(null)" : exname);
+     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
+     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
+     // No need to check this sig any longer
+@@ -5007,10 +5008,10 @@
+     // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
+     if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
+       tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
+-                    exception_name(sig, buf, O_BUFLEN));
++                    exname == NULL ? "(null)" : exname);
+     }
+   } else if(os::Linux::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Linux::get_our_sigflags(sig)) {
+-    tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
++    tty->print("Warning: %s handler flags ", exname == NULL ? "(null)" : exname);
+     tty->print("expected:" PTR32_FORMAT, os::Linux::get_our_sigflags(sig));
+     tty->print_cr("  found:" PTR32_FORMAT, act.sa_flags);
+     // No need to check this sig any longer