more cleanup

src/hotspot/cpu/aarch64/nativeInst_aarch64.cpp

@@ -212,11 +212,6 @@ void NativeMovRegMem::verify() {
 
 void NativeJump::verify() { ; }
 
-
-void NativeJump::check_verified_entry_alignment(address entry, address verified_entry) {
-}
-
-
 address NativeJump::jump_destination() const          {
   address dest = MacroAssembler::target_addr_for_insn_or_null(instruction_address());
 
@@ -359,31 +354,6 @@ bool NativeInstruction::is_stop() {
 
 //-------------------------------------------------------------------
 
-// MT-safe inserting of a jump over a jump or a nop (used by
-// nmethod::make_not_entrant)
-
-void NativeJump::patch_verified_entry(address entry, address verified_entry, address dest) {
-
-  assert(dest == SharedRuntime::get_handle_wrong_method_stub(), "expected fixed destination of patch");
-  assert(nativeInstruction_at(verified_entry)->is_jump_or_nop()
-         || nativeInstruction_at(verified_entry)->is_sigill_not_entrant(),
-         "Aarch64 cannot replace non-jump with jump");
-
-  // Patch this nmethod atomically.
-  if (Assembler::reachable_from_branch_at(verified_entry, dest)) {
-    ptrdiff_t disp = dest - verified_entry;
-    guarantee(disp < 1 << 27 && disp > - (1 << 27), "branch overflow");
-
-    unsigned int insn = (0b000101 << 26) | ((disp >> 2) & 0x3ffffff);
-    *(unsigned int*)verified_entry = insn;
-  } else {
-    // We use an illegal instruction for marking a method as not_entrant.
-    NativeIllegalInstruction::insert(verified_entry);
-  }
-
-  ICache::invalidate_range(verified_entry, instruction_size);
-}
-
 void NativeGeneralJump::verify() {  }
 
 void NativeGeneralJump::insert_unconditional(address code_pos, address entry) {

src/hotspot/cpu/aarch64/nativeInst_aarch64.hpp

@@ -360,9 +360,6 @@ public:
 
   // Insertion of native jump instruction
   static void insert(address code_pos, address entry);
-  // MT-safe insertion of native jump at verified method entry
-  static void check_verified_entry_alignment(address entry, address verified_entry);
-  static void patch_verified_entry(address entry, address verified_entry, address dest);
 };
 
 inline NativeJump* nativeJump_at(address address) {

src/hotspot/cpu/arm/nativeInst_arm_32.cpp

@@ -282,16 +282,6 @@ void NativeMovConstReg::set_pc_relative_offset(address addr, address pc) {
   }
 }
 
-void RawNativeJump::check_verified_entry_alignment(address entry, address verified_entry) {
-}
-
-void RawNativeJump::patch_verified_entry(address entry, address verified_entry, address dest) {
-  assert(dest == SharedRuntime::get_handle_wrong_method_stub(), "should be");
-  int *a = (int *)verified_entry;
-  a[0] = not_entrant_illegal_instruction; // always illegal
-  ICache::invalidate_range((address)&a[0], sizeof a[0]);
-}
-
 void NativeGeneralJump::insert_unconditional(address code_pos, address entry) {
   int offset = (int)(entry - code_pos - 8);
   assert(offset < 0x2000000 && offset > -0x2000000, "encoding constraint");

src/hotspot/cpu/arm/nativeInst_arm_32.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2025, 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
@@ -61,10 +61,6 @@ class RawNativeInstruction {
     instr_fld_fst    = 0xd0
   };
 
-  // illegal instruction used by NativeJump::patch_verified_entry
-  // permanently undefined (UDF): 0xe << 28 | 0b1111111 << 20 | 0b1111 << 4
-  static const int not_entrant_illegal_instruction = 0xe7f000f0;
-
   static int decode_rotated_imm12(int encoding) {
     int base = encoding & 0xff;
     int right_rotation = (encoding & 0xf00) >> 7;
@@ -274,10 +270,6 @@ class RawNativeJump: public NativeInstruction {
     }
   }
 
-  static void check_verified_entry_alignment(address entry, address verified_entry);
-
-  static void patch_verified_entry(address entry, address verified_entry, address dest);
-
 };
 
 inline RawNativeJump* rawNativeJump_at(address address) {

src/hotspot/cpu/ppc/c1_MacroAssembler_ppc.cpp

@@ -46,7 +46,6 @@ void C1_MacroAssembler::explicit_null_check(Register base) {
 
 
 void C1_MacroAssembler::build_frame(int frame_size_in_bytes, int bang_size_in_bytes) {
-  // Avoid stack bang as first instruction. It may get overwritten by patch_verified_entry.
   const Register return_pc = R20;
   mflr(return_pc);
 

src/hotspot/cpu/ppc/nativeInst_ppc.cpp

@@ -39,18 +39,6 @@
 #include "c1/c1_Runtime1.hpp"
 #endif
 
-// We use an illtrap for marking a method as not_entrant
-// Work around a C++ compiler bug which changes 'this'
-bool NativeInstruction::is_sigill_not_entrant_at(address addr) {
-  if (!Assembler::is_illtrap(addr)) return false;
-  CodeBlob* cb = CodeCache::find_blob(addr);
-  if (cb == nullptr || !cb->is_nmethod()) return false;
-  nmethod *nm = (nmethod *)cb;
-  // This method is not_entrant iff the illtrap instruction is
-  // located at the verified entry point.
-  return nm->verified_entry_point() == addr;
-}
-
 #ifdef ASSERT
 void NativeInstruction::verify() {
   // Make sure code pattern is actually an instruction address.
@@ -331,25 +319,6 @@ void NativeMovConstReg::verify() {
 }
 #endif // ASSERT
 
-void NativeJump::patch_verified_entry(address entry, address verified_entry, address dest) {
-  ResourceMark rm;
-  int code_size = 1 * BytesPerInstWord;
-  CodeBuffer cb(verified_entry, code_size + 1);
-  MacroAssembler* a = new MacroAssembler(&cb);
-#ifdef COMPILER2
-  assert(dest == SharedRuntime::get_handle_wrong_method_stub(), "expected fixed destination of patch");
-#endif
-  // Patch this nmethod atomically. Always use illtrap/trap in debug build.
-  if (DEBUG_ONLY(false &&) a->is_within_range_of_b(dest, a->pc())) {
-    a->b(dest);
-  } else {
-    // The signal handler will continue at dest=OptoRuntime::handle_wrong_method_stub().
-    // We use an illtrap for marking a method as not_entrant.
-    a->illtrap();
-  }
-  ICache::ppc64_flush_icache_bytes(verified_entry, code_size);
-}
-
 #ifdef ASSERT
 void NativeJump::verify() {
   address addr = addr_at(0);
@@ -462,9 +431,7 @@ bool NativeDeoptInstruction::is_deopt_at(address code_pos) {
   if (!Assembler::is_illtrap(code_pos)) return false;
   CodeBlob* cb = CodeCache::find_blob(code_pos);
   if (cb == nullptr || !cb->is_nmethod()) return false;
-  nmethod *nm = (nmethod *)cb;
-  // see NativeInstruction::is_sigill_not_entrant_at()
-  return nm->verified_entry_point() != code_pos;
+  return true;
 }
 
 // Inserts an instruction which is specified to cause a SIGILL at a given pc

src/hotspot/cpu/ppc/nativeInst_ppc.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2025, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2012, 2024 SAP SE. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -328,15 +328,7 @@ class NativeJump: public NativeInstruction {
     }
   }
 
-  // MT-safe insertion of native jump at verified method entry
-  static void patch_verified_entry(address entry, address verified_entry, address dest);
-
   void verify() NOT_DEBUG_RETURN;
-
-  static void check_verified_entry_alignment(address entry, address verified_entry) {
-    // We just patch one instruction on ppc64, so the jump doesn't have to
-    // be aligned. Nothing to do here.
-  }
 };
 
 // Instantiates a NativeJump object starting at the given instruction

src/hotspot/cpu/riscv/nativeInst_riscv.cpp

@@ -356,18 +356,6 @@ void NativeMovRegMem::verify() {
 
 void NativeJump::verify() { }
 
-
-void NativeJump::check_verified_entry_alignment(address entry, address verified_entry) {
-  // Patching to not_entrant can happen while activations of the method are
-  // in use. The patching in that instance must happen only when certain
-  // alignment restrictions are true. These guarantees check those
-  // conditions.
-
-  // Must be 4 bytes aligned
-  MacroAssembler::assert_alignment(verified_entry);
-}
-
-
 address NativeJump::jump_destination() const {
   address dest = MacroAssembler::target_addr_for_insn(instruction_address());
 
@@ -437,45 +425,6 @@ bool NativeInstruction::is_stop() {
 
 //-------------------------------------------------------------------
 
-// MT-safe inserting of a jump over a jump or a nop (used by
-// nmethod::make_not_entrant)
-
-void NativeJump::patch_verified_entry(address entry, address verified_entry, address dest) {
-
-  assert(dest == SharedRuntime::get_handle_wrong_method_stub(), "expected fixed destination of patch");
-
-  assert(nativeInstruction_at(verified_entry)->is_jump_or_nop() ||
-         nativeInstruction_at(verified_entry)->is_sigill_not_entrant(),
-         "riscv cannot replace non-jump with jump");
-
-  check_verified_entry_alignment(entry, verified_entry);
-
-  // Patch this nmethod atomically.
-  if (Assembler::reachable_from_branch_at(verified_entry, dest)) {
-    ptrdiff_t offset = dest - verified_entry;
-    guarantee(Assembler::is_simm21(offset) && ((offset % 2) == 0),
-              "offset is too large to be patched in one jal instruction."); // 1M
-
-    uint32_t insn = 0;
-    address pInsn = (address)&insn;
-    Assembler::patch(pInsn, 31, 31, (offset >> 20) & 0x1);
-    Assembler::patch(pInsn, 30, 21, (offset >> 1) & 0x3ff);
-    Assembler::patch(pInsn, 20, 20, (offset >> 11) & 0x1);
-    Assembler::patch(pInsn, 19, 12, (offset >> 12) & 0xff);
-    Assembler::patch(pInsn, 11, 7, 0); // zero, no link jump
-    Assembler::patch(pInsn, 6, 0, 0b1101111); // j, (jal x0 offset)
-    Assembler::sd_instr(verified_entry, insn);
-  } else {
-    // We use an illegal instruction for marking a method as
-    // not_entrant.
-    NativeIllegalInstruction::insert(verified_entry);
-  }
-
-  ICache::invalidate_range(verified_entry, instruction_size);
-}
-
-//-------------------------------------------------------------------
-
 void NativeGeneralJump::insert_unconditional(address code_pos, address entry) {
   CodeBuffer cb(code_pos, instruction_size);
   MacroAssembler a(&cb);

src/hotspot/cpu/riscv/nativeInst_riscv.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2014, 2018, Red Hat Inc. All rights reserved.
  * Copyright (c) 2020, 2023, Huawei Technologies Co., Ltd. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
@@ -274,9 +274,6 @@ class NativeJump: public NativeInstruction {
 
   // Insertion of native jump instruction
   static void insert(address code_pos, address entry);
-  // MT-safe insertion of native jump at verified method entry
-  static void check_verified_entry_alignment(address entry, address verified_entry);
-  static void patch_verified_entry(address entry, address verified_entry, address dest);
 };
 
 inline NativeJump* nativeJump_at(address addr) {

src/hotspot/cpu/riscv/riscv.ad

@@ -1796,7 +1796,6 @@ void MachUEPNode::emit(C2_MacroAssembler* masm, PhaseRegAlloc* ra_) const
   // This is the unverified entry point.
   __ ic_check(CodeEntryAlignment);
 
-  // Verified entry point must be properly 4 bytes aligned for patching by NativeJump::patch_verified_entry().
   // ic_check() aligns to CodeEntryAlignment >= InteriorEntryAlignment(min 16) > NativeInstruction::instruction_size(4).
   assert(((__ offset()) % CodeEntryAlignment) == 0, "Misaligned verified entry point");
 }
@@ -8191,7 +8190,7 @@ instruct unnecessary_membar_volatile_rvtso() %{
   ins_cost(0);
 
   size(0);
-  
+ 
   format %{ "#@unnecessary_membar_volatile_rvtso (unnecessary so empty encoding)" %}
   ins_encode %{
     __ block_comment("unnecessary_membar_volatile_rvtso");

src/hotspot/cpu/s390/nativeInst_s390.cpp

@@ -167,27 +167,6 @@ bool NativeInstruction::is_illegal() {
   return halfword_at(-2) == illegal_instruction();
 }
 
-// We use an illtrap for marking a method as not_entrant.
-bool NativeInstruction::is_sigill_not_entrant() {
-  if (!is_illegal()) return false; // Just a quick path.
-
-  // One-sided error of is_illegal tolerable here
-  // (see implementation of is_illegal() for details).
-
-  CodeBlob* cb = CodeCache::find_blob(addr_at(0));
-  if (cb == nullptr || !cb->is_nmethod()) {
-    return false;
-  }
-
-  nmethod *nm = (nmethod *)cb;
-  // This method is not_entrant if the illtrap instruction
-  // is located at the verified entry point.
-  // BE AWARE: the current pc (this) points to the instruction after the
-  // "illtrap" location.
-  address sig_addr = ((address) this) - 2;
-  return nm->verified_entry_point() == sig_addr;
-}
-
 bool NativeInstruction::is_jump() {
   unsigned long inst;
   Assembler::get_instruction((address)this, &inst);
@@ -620,19 +599,6 @@ void NativeJump::verify() {
   fatal("this is not a `NativeJump' site");
 }
 
-// Patch atomically with an illtrap.
-void NativeJump::patch_verified_entry(address entry, address verified_entry, address dest) {
-  ResourceMark rm;
-  int code_size = 2;
-  CodeBuffer cb(verified_entry, code_size + 1);
-  MacroAssembler* a = new MacroAssembler(&cb);
-#ifdef COMPILER2
-  assert(dest == SharedRuntime::get_handle_wrong_method_stub(), "expected fixed destination of patch");
-#endif
-  a->z_illtrap();
-  ICache::invalidate_range(verified_entry, code_size);
-}
-
 #undef LUCY_DBG
 
 //-------------------------------------

src/hotspot/cpu/s390/nativeInst_s390.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2025, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2016, 2024 SAP SE. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -609,11 +609,6 @@ class NativeJump: public NativeInstruction {
 
   // Insertion of native jump instruction.
   static void insert(address code_pos, address entry);
-
-  // MT-safe insertion of native jump at verified method entry.
-  static void check_verified_entry_alignment(address entry, address verified_entry) { }
-
-  static void patch_verified_entry(address entry, address verified_entry, address dest);
 };
 
 //-------------------------------------

src/hotspot/cpu/zero/nativeInst_zero.cpp

@@ -1,44 +0,0 @@
-/*
- * Copyright (c) 2003, 2025, Oracle and/or its affiliates. All rights reserved.
- * Copyright 2008 Red Hat, Inc.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- *
- */
-
-#include "asm/assembler.inline.hpp"
-#include "entry_zero.hpp"
-#include "interpreter/zero/zeroInterpreter.hpp"
-#include "nativeInst_zero.hpp"
-#include "runtime/sharedRuntime.hpp"
-
-// This method is called by nmethod::make_not_entrant to
-// insert a jump to SharedRuntime::get_handle_wrong_method_stub()
-// (dest) at the start of a compiled method (verified_entry) to avoid
-// a race where a method is invoked while being made non-entrant.
-
-void NativeJump::patch_verified_entry(address entry,
-                                      address verified_entry,
-                                      address dest) {
-  assert(dest == SharedRuntime::get_handle_wrong_method_stub(), "should be");
-
-  ((ZeroEntry*) verified_entry)->set_entry_point(
-    (address) ZeroInterpreter::normal_entry);
-}

src/hotspot/cpu/zero/nativeInst_zero.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2025, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2007 Red Hat, Inc.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -177,14 +177,6 @@ class NativeJump : public NativeInstruction {
   void set_jump_destination(address dest) {
     ShouldNotCallThis();
   }
-
-  static void check_verified_entry_alignment(address entry,
-                                             address verified_entry) {
-  }
-
-  static void patch_verified_entry(address entry,
-                                   address verified_entry,
-                                   address dest);
 };
 
 inline NativeJump* nativeJump_at(address address) {

src/hotspot/os/windows/os_windows.cpp

@@ -2752,19 +2752,6 @@ LONG WINAPI topLevelExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
       }
     }
 
-#ifdef _M_ARM64
-    if (in_java &&
-        (exception_code == EXCEPTION_ILLEGAL_INSTRUCTION ||
-          exception_code == EXCEPTION_ILLEGAL_INSTRUCTION_2)) {
-      if (nativeInstruction_at(pc)->is_sigill_not_entrant()) {
-        if (TraceTraps) {
-          tty->print_cr("trap: not_entrant");
-        }
-        return Handle_Exception(exceptionInfo, SharedRuntime::get_handle_wrong_method_stub());
-      }
-    }
-#endif
-
     if (in_java) {
       switch (exception_code) {
       case EXCEPTION_INT_DIVIDE_BY_ZERO:

src/hotspot/os_cpu/aix_ppc/os_aix_ppc.cpp

@@ -229,16 +229,7 @@ bool PosixSignals::pd_hotspot_signal_handler(int sig, siginfo_t* info,
 
       CodeBlob *cb = nullptr;
       int stop_type = -1;
-      // Handle signal from NativeJump::patch_verified_entry().
-      if (sig == SIGILL && nativeInstruction_at(pc)->is_sigill_not_entrant()) {
-        if (TraceTraps) {
-          tty->print_cr("trap: not_entrant");
-        }
-        stub = SharedRuntime::get_handle_wrong_method_stub();
-        goto run_stub;
-      }
-
-      else if ((sig == (USE_POLL_BIT_ONLY ? SIGTRAP : SIGSEGV)) &&
+      if ((sig == (USE_POLL_BIT_ONLY ? SIGTRAP : SIGSEGV)) &&
                ((NativeInstruction*)pc)->is_safepoint_poll() &&
                CodeCache::contains((void*) pc) &&
                ((cb = CodeCache::find_blob(pc)) != nullptr) &&

src/hotspot/os_cpu/bsd_aarch64/os_bsd_aarch64.cpp

@@ -271,14 +271,7 @@ bool PosixSignals::pd_hotspot_signal_handler(int sig, siginfo_t* info,
       // Java thread running in Java code => find exception handler if any
       // a fault inside compiled code, the interpreter, or a stub
 
-      // Handle signal from NativeJump::patch_verified_entry().
-      if ((sig == SIGILL)
-          && nativeInstruction_at(pc)->is_sigill_not_entrant()) {
-        if (TraceTraps) {
-          tty->print_cr("trap: not_entrant");
-        }
-        stub = SharedRuntime::get_handle_wrong_method_stub();
-      } else if ((sig == SIGSEGV || sig == SIGBUS) && SafepointMechanism::is_poll_address((address)info->si_addr)) {
+      if ((sig == SIGSEGV || sig == SIGBUS) && SafepointMechanism::is_poll_address((address)info->si_addr)) {
         stub = SharedRuntime::get_poll_stub(pc);
 #if defined(__APPLE__)
       // 32-bit Darwin reports a SIGBUS for nearly all memory access exceptions.

src/hotspot/os_cpu/linux_aarch64/os_linux_aarch64.cpp

@@ -232,14 +232,7 @@ bool PosixSignals::pd_hotspot_signal_handler(int sig, siginfo_t* info,
       // Java thread running in Java code => find exception handler if any
       // a fault inside compiled code, the interpreter, or a stub
 
-      // Handle signal from NativeJump::patch_verified_entry().
-      if ((sig == SIGILL || sig == SIGTRAP)
-          && nativeInstruction_at(pc)->is_sigill_not_entrant()) {
-        if (TraceTraps) {
-          tty->print_cr("trap: not_entrant (%s)", (sig == SIGTRAP) ? "SIGTRAP" : "SIGILL");
-        }
-        stub = SharedRuntime::get_handle_wrong_method_stub();
-      } else if (sig == SIGSEGV && SafepointMechanism::is_poll_address((address)info->si_addr)) {
+      if (sig == SIGSEGV && SafepointMechanism::is_poll_address((address)info->si_addr)) {
         stub = SharedRuntime::get_poll_stub(pc);
       } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) {
         // BugId 4454115: A read from a MappedByteBuffer can fault

src/hotspot/os_cpu/linux_arm/os_linux_arm.cpp

@@ -359,11 +359,6 @@ bool PosixSignals::pd_hotspot_signal_handler(int sig, siginfo_t* info,
           stub = SharedRuntime::continuation_for_implicit_exception(
               thread, pc, SharedRuntime::IMPLICIT_NULL);
         }
-      } else if (sig == SIGILL &&
-                 *(int*)pc ==
-                     NativeInstruction::not_entrant_illegal_instruction) {
-        // Not entrant
-        stub = SharedRuntime::get_handle_wrong_method_stub();
       }
     } else if ((thread->thread_state() == _thread_in_vm ||
                 thread->thread_state() == _thread_in_native) &&

src/hotspot/os_cpu/linux_ppc/os_linux_ppc.cpp

@@ -258,15 +258,7 @@ bool PosixSignals::pd_hotspot_signal_handler(int sig, siginfo_t* info,
 
       CodeBlob *cb = nullptr;
       int stop_type = -1;
-      // Handle signal from NativeJump::patch_verified_entry().
-      if (sig == SIGILL && nativeInstruction_at(pc)->is_sigill_not_entrant()) {
-        if (TraceTraps) {
-          tty->print_cr("trap: not_entrant");
-        }
-        stub = SharedRuntime::get_handle_wrong_method_stub();
-      }
-
-      else if ((sig == (USE_POLL_BIT_ONLY ? SIGTRAP : SIGSEGV)) &&
+      if ((sig == (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

src/hotspot/os_cpu/linux_riscv/os_linux_riscv.cpp

@@ -223,14 +223,7 @@ bool PosixSignals::pd_hotspot_signal_handler(int sig, siginfo_t* info,
       // Java thread running in Java code => find exception handler if any
       // a fault inside compiled code, the interpreter, or a stub
 
-      // Handle signal from NativeJump::patch_verified_entry().
-      if ((sig == SIGILL || sig == SIGTRAP)
-          && nativeInstruction_at(pc)->is_sigill_not_entrant()) {
-        if (TraceTraps) {
-          tty->print_cr("trap: not_entrant (%s)", (sig == SIGTRAP) ? "SIGTRAP" : "SIGILL");
-        }
-        stub = SharedRuntime::get_handle_wrong_method_stub();
-      } else if (sig == SIGSEGV && SafepointMechanism::is_poll_address((address)info->si_addr)) {
+      if (sig == SIGSEGV && SafepointMechanism::is_poll_address((address)info->si_addr)) {
         stub = SharedRuntime::get_poll_stub(pc);
       } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) {
         // BugId 4454115: A read from a MappedByteBuffer can fault

src/hotspot/os_cpu/linux_s390/os_linux_s390.cpp

@@ -257,15 +257,7 @@ bool PosixSignals::pd_hotspot_signal_handler(int sig, siginfo_t* info,
       // Java thread running in Java code => find exception handler if any
       // a fault inside compiled code, the interpreter, or a stub
 
-      // Handle signal from NativeJump::patch_verified_entry().
-      if (sig == SIGILL && nativeInstruction_at(pc)->is_sigill_not_entrant()) {
-        if (TraceTraps) {
-          tty->print_cr("trap: not_entrant (SIGILL)");
-        }
-        stub = SharedRuntime::get_handle_wrong_method_stub();
-      }
-
-      else if (sig == SIGSEGV &&
+      if (sig == SIGSEGV &&
                SafepointMechanism::is_poll_address((address)info->si_addr)) {
         if (TraceTraps) {
           tty->print_cr("trap: safepoint_poll at " INTPTR_FORMAT " (SIGSEGV)", p2i(pc));

src/hotspot/share/gc/shared/barrierSetNMethod.cpp

@@ -83,7 +83,10 @@ void BarrierSetNMethod::arm_with(nmethod* nm, int value) {
   if (is_not_entrant(nm)) {
     value |= not_entrant;
   }
-  set_guard_value(nm, value);
+  if (guard_value(nm) != value) {
+    // Patch the code only if needed.
+    set_guard_value(nm, value);
+  }
 }
 
 bool BarrierSetNMethod::is_armed(nmethod* nm) {
@@ -243,7 +246,10 @@ void BarrierSetNMethod::make_not_entrant(nmethod* nm) {
   // Enter critical section.  Does not block for safepoint.
   ConditionalMutexLocker ml(NMethodEntryBarrier_lock, !NMethodEntryBarrier_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
   int value = guard_value(nm) | not_entrant;
-  set_guard_value(nm, value);
+  if (guard_value(nm) != value) {
+    // Patch the code only if needed.
+    set_guard_value(nm, value);
+  }
 }
 
 bool BarrierSetNMethod::is_not_entrant(nmethod* nm) {

src/hotspot/share/gc/shared/barrierSetNMethod.hpp

@@ -43,7 +43,6 @@ private:
   };
 
   void deoptimize(nmethod* nm, address* return_addr_ptr);
-  void arm(nmethod* nm) { arm_with(nm, armed); }
 
 protected:
   virtual int guard_value(nmethod* nm);
@@ -62,6 +61,7 @@ public:
   static int nmethod_stub_entry_barrier(address* return_address_ptr);
   bool nmethod_osr_entry_barrier(nmethod* nm);
   virtual bool is_armed(nmethod* nm);
+  void arm(nmethod* nm) { arm_with(nm, armed); }
   void disarm(nmethod* nm);
   virtual void make_not_entrant(nmethod* nm);
   virtual bool is_not_entrant(nmethod* nm);

src/hotspot/share/gc/z/zBarrierSetNMethod.cpp

@@ -113,7 +113,10 @@ void ZBarrierSetNMethod::arm_with(nmethod* nm, int value) {
   if (is_not_entrant(nm)) {
     value |= not_entrant;
   }
-  set_guard_value(nm, value);
+  if (guard_value(nm) != value) {
+    // Patch the code only if needed.
+    set_guard_value(nm, value);
+  }
 }
 
 bool ZBarrierSetNMethod::is_armed(nmethod* nm) {