diff --git a/src/hotspot/cpu/aarch64/immediate_aarch64.cpp b/src/hotspot/cpu/aarch64/immediate_aarch64.cpp
index 710a1f0677d..eb4cb23100c 100644
--- a/src/hotspot/cpu/aarch64/immediate_aarch64.cpp
+++ b/src/hotspot/cpu/aarch64/immediate_aarch64.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2023, 2026, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2014, 2020, Red Hat Inc. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -23,13 +23,13 @@
  *
  */
 
-#include <stdlib.h> // do not reorder
-#include <stdint.h> // do not reorder
-
+#include "cppstdlib/cstdlib.hpp"
 #include "immediate_aarch64.hpp"
 #include "metaprogramming/primitiveConversions.hpp"
 #include "utilities/globalDefinitions.hpp"
 
+#include <stdint.h>
+
 // there are at most 2^13 possible logical immediate encodings
 // however, some combinations of immr and imms are invalid
 static const unsigned  LI_TABLE_SIZE = (1 << 13);
diff --git a/src/hotspot/cpu/aarch64/immediate_aarch64.hpp b/src/hotspot/cpu/aarch64/immediate_aarch64.hpp
index 0cbdb562088..fb38995417b 100644
--- a/src/hotspot/cpu/aarch64/immediate_aarch64.hpp
+++ b/src/hotspot/cpu/aarch64/immediate_aarch64.hpp
@@ -1,4 +1,5 @@
 /*
+ * Copyright (c) 2025, 2026, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2014, Red Hat Inc. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -22,10 +23,10 @@
  *
  */
 
-#ifndef _IMMEDIATE_H
-#define _IMMEDIATE_H
+#ifndef CPU_AARCH64_IMMEDIATE_AARCH64_HPP
+#define CPU_AARCH64_IMMEDIATE_AARCH64_HPP
 
-#include <sys/types.h>
+#include <stdint.h>
 
 /*
  * functions to map backwards and forwards between logical or floating
@@ -51,4 +52,4 @@ uint32_t encoding_for_logical_immediate(uint64_t immediate);
 uint64_t fp_immediate_for_encoding(uint32_t imm8, int is_dp);
 uint32_t encoding_for_fp_immediate(float immediate);
 
-#endif // _IMMEDIATE_H
+#endif // CPU_AARCH64_IMMEDIATE_AARCH64_HPP
diff --git a/src/hotspot/os/aix/libodm_aix.cpp b/src/hotspot/os/aix/libodm_aix.cpp
index 035703a1771..38e8067181a 100644
--- a/src/hotspot/os/aix/libodm_aix.cpp
+++ b/src/hotspot/os/aix/libodm_aix.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2026, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2015, 2019 SAP SE. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -23,15 +23,15 @@
  *
  */
 
+#include "cppstdlib/cstdlib.hpp"
 #include "libodm_aix.hpp"
 #include "misc_aix.hpp"
-#include <stdlib.h>
-#include <dlfcn.h>
-#include <string.h>
 #include "runtime/arguments.hpp"
 #include "runtime/os.hpp"
 #include "utilities/permitForbiddenFunctions.hpp"
 
+#include <dlfcn.h>
+#include <string.h>
 
 dynamicOdm::dynamicOdm() {
   const char* libodmname = "/usr/lib/libodm.a(shr_64.o)";
diff --git a/src/hotspot/os/aix/libperfstat_aix.hpp b/src/hotspot/os/aix/libperfstat_aix.hpp
index 5a6ddfd8f4d..aff11cfb41f 100644
--- a/src/hotspot/os/aix/libperfstat_aix.hpp
+++ b/src/hotspot/os/aix/libperfstat_aix.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2022, 2026, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2012, 2024 SAP SE. All rights reserved.
  * Copyright (c) 2022, IBM Corp.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
@@ -32,8 +32,9 @@
 #ifndef OS_AIX_LIBPERFSTAT_AIX_HPP
 #define OS_AIX_LIBPERFSTAT_AIX_HPP
 
+#include "cppstdlib/cstdlib.hpp"
+
 #include <sys/types.h>
-#include <stdlib.h>
 
 ///////////////////////////////////////////////////////////////////////////////////////////////
 // These are excerpts from the AIX 7.1 libperfstat.h -
diff --git a/src/hotspot/os/aix/os_perf_aix.cpp b/src/hotspot/os/aix/os_perf_aix.cpp
index 8444002b871..aa8819d035f 100644
--- a/src/hotspot/os/aix/os_perf_aix.cpp
+++ b/src/hotspot/os/aix/os_perf_aix.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2026, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2022, 2024, IBM Corp.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -23,6 +23,7 @@
  *
  */
 
+#include "cppstdlib/cstdlib.hpp"
 #include "jvm.h"
 #include "libperfstat_aix.hpp"
 #include "memory/allocation.inline.hpp"
@@ -46,7 +47,6 @@
 #include <sys/resource.h>
 #include <sys/stat.h>
 #include <sys/types.h>
-#include <stdlib.h>
 #include <unistd.h>
 
 typedef struct {
diff --git a/src/hotspot/os/bsd/memMapPrinter_macosx.cpp b/src/hotspot/os/bsd/memMapPrinter_macosx.cpp
index a7ddab04d85..6fd08d63e85 100644
--- a/src/hotspot/os/bsd/memMapPrinter_macosx.cpp
+++ b/src/hotspot/os/bsd/memMapPrinter_macosx.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2023, 2026, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2023, 2024, Red Hat, Inc. and/or its affiliates.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -25,6 +25,7 @@
 
 #if defined(__APPLE__)
 
+#include "cppstdlib/cstdlib.hpp"
 #include "nmt/memMapPrinter.hpp"
 #include "runtime/os.hpp"
 #include "utilities/align.hpp"
@@ -34,7 +35,6 @@
 
 #include <limits.h>
 #include <stdio.h>
-#include <stdlib.h>
 #include <libproc.h>
 #include <unistd.h>
 
diff --git a/src/hotspot/os/linux/os_linux.cpp b/src/hotspot/os/linux/os_linux.cpp
index a28f9850495..88e5e9b582a 100644
--- a/src/hotspot/os/linux/os_linux.cpp
+++ b/src/hotspot/os/linux/os_linux.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2026, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2015, 2024 SAP SE. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -27,6 +27,7 @@
 #include "code/vtableStubs.hpp"
 #include "compiler/compileBroker.hpp"
 #include "compiler/disassembler.hpp"
+#include "cppstdlib/cstdlib.hpp"
 #include "hugepages.hpp"
 #include "interpreter/interpreter.hpp"
 #include "jvm.h"
@@ -96,7 +97,6 @@
 # include <signal.h>
 # include <stdint.h>
 # include <stdio.h>
-# include <stdlib.h>
 # include <string.h>
 # include <sys/ioctl.h>
 # include <sys/ipc.h>
diff --git a/src/hotspot/os/linux/os_perf_linux.cpp b/src/hotspot/os/linux/os_perf_linux.cpp
index 5708194521f..9f91f3b4c0d 100644
--- a/src/hotspot/os/linux/os_perf_linux.cpp
+++ b/src/hotspot/os/linux/os_perf_linux.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2026, 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
@@ -22,6 +22,7 @@
  *
  */
 
+#include "cppstdlib/cstdlib.hpp"
 #include "jvm.h"
 #include "memory/allocation.inline.hpp"
 #include "os_linux.inline.hpp"
@@ -40,7 +41,6 @@
 #include <pthread.h>
 #include <stdarg.h>
 #include <stdio.h>
-#include <stdlib.h>
 #include <string.h>
 #include <sys/resource.h>
 #include <sys/stat.h>
diff --git a/src/hotspot/os/posix/forbiddenFunctions_posix.hpp b/src/hotspot/os/posix/forbiddenFunctions_posix.hpp
index 529cf22078e..1c91e9d2599 100644
--- a/src/hotspot/os/posix/forbiddenFunctions_posix.hpp
+++ b/src/hotspot/os/posix/forbiddenFunctions_posix.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2024, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2024, 2026, 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
@@ -36,15 +36,12 @@
 #include <unistd.h>
 #endif
 
+// POSIX puts _exit in <unistd.h>.
+FORBID_IMPORTED_NORETURN_C_FUNCTION(void _exit(int), /* not noexcept */, "use os::exit")
+
 // If needed, add os::strndup and use that instead.
 FORBID_C_FUNCTION(char* strndup(const char*, size_t), noexcept, "don't use");
 
-// These are unimplementable for Windows, and they aren't useful for a
-// POSIX implementation of NMT either.
-// https://stackoverflow.com/questions/62962839/stdaligned-alloc-missing-from-visual-studio-2019
-FORBID_C_FUNCTION(int posix_memalign(void**, size_t, size_t), noexcept, "don't use");
-FORBID_C_FUNCTION(void* aligned_alloc(size_t, size_t), noexcept, "don't use");
-
 // realpath with a null second argument mallocs a string for the result.
 // With a non-null second argument, there is a risk of buffer overrun.
 PRAGMA_DIAG_PUSH
diff --git a/src/hotspot/os/posix/os_posix.cpp b/src/hotspot/os/posix/os_posix.cpp
index 07e1920c62d..4cae7d359e4 100644
--- a/src/hotspot/os/posix/os_posix.cpp
+++ b/src/hotspot/os/posix/os_posix.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2026, 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
@@ -23,6 +23,7 @@
  */
 
 #include "classfile/classLoader.hpp"
+#include "cppstdlib/cstdlib.hpp"
 #include "interpreter/interpreter.hpp"
 #include "jvm.h"
 #include "jvmtifiles/jvmti.h"
diff --git a/src/hotspot/os/posix/permitForbiddenFunctions_posix.hpp b/src/hotspot/os/posix/permitForbiddenFunctions_posix.hpp
index 3ff8c383a31..b45cede2e5f 100644
--- a/src/hotspot/os/posix/permitForbiddenFunctions_posix.hpp
+++ b/src/hotspot/os/posix/permitForbiddenFunctions_posix.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2024, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2024, 2026, 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
@@ -25,15 +25,20 @@
 #ifndef OS_POSIX_PERMITFORBIDDENFUNCTIONS_POSIX_HPP
 #define OS_POSIX_PERMITFORBIDDENFUNCTIONS_POSIX_HPP
 
+#include "cppstdlib/cstdlib.hpp"
 #include "utilities/compilerWarnings.hpp"
 #include "utilities/globalDefinitions.hpp"
 
+#include <unistd.h>
+
 // Provide wrappers for some functions otherwise forbidden from use in HotSpot.
 // See forbiddenFunctions.hpp for details.
 
 namespace permit_forbidden_function {
 BEGIN_ALLOW_FORBIDDEN_FUNCTIONS
 
+[[noreturn]] inline void _exit(int status) { ::_exit(status); }
+
 // Used by the POSIX implementation of os::realpath.
 inline char* realpath(const char* path, char* resolved_path) {
   return ::realpath(path, resolved_path);
diff --git a/src/hotspot/os/windows/os_windows.cpp b/src/hotspot/os/windows/os_windows.cpp
index 0ac05e8a435..efbd1fe7c68 100644
--- a/src/hotspot/os/windows/os_windows.cpp
+++ b/src/hotspot/os/windows/os_windows.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2026, 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
@@ -30,6 +30,7 @@
 #include "code/vtableStubs.hpp"
 #include "compiler/compileBroker.hpp"
 #include "compiler/disassembler.hpp"
+#include "cppstdlib/cstdlib.hpp"
 #include "interpreter/interpreter.hpp"
 #include "jvm.h"
 #include "jvmtifiles/jvmti.h"
diff --git a/src/hotspot/os/windows/permitForbiddenFunctions_windows.hpp b/src/hotspot/os/windows/permitForbiddenFunctions_windows.hpp
index 99e77464fbd..fbd476ceb60 100644
--- a/src/hotspot/os/windows/permitForbiddenFunctions_windows.hpp
+++ b/src/hotspot/os/windows/permitForbiddenFunctions_windows.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2024, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2024, 2026, 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
@@ -25,6 +25,7 @@
 #ifndef OS_WINDOWS_PERMITFORBIDDENFUNCTIONS_WINDOWS_HPP
 #define OS_WINDOWS_PERMITFORBIDDENFUNCTIONS_WINDOWS_HPP
 
+#include "cppstdlib/cstdlib.hpp"
 #include "utilities/compilerWarnings.hpp"
 #include "utilities/globalDefinitions.hpp"
 
@@ -34,6 +35,8 @@
 namespace permit_forbidden_function {
 BEGIN_ALLOW_FORBIDDEN_FUNCTIONS
 
+[[noreturn]] inline void _exit(int status) { ::_exit(status); }
+
 // Used by the Windows implementation of os::realpath.
 inline char* _fullpath(char* absPath, const char* relPath, size_t maxLength) {
   return ::_fullpath(absPath, relPath, maxLength);
diff --git a/src/hotspot/os/windows/vmError_windows.cpp b/src/hotspot/os/windows/vmError_windows.cpp
index 22df4d82cbf..66df38d2734 100644
--- a/src/hotspot/os/windows/vmError_windows.cpp
+++ b/src/hotspot/os/windows/vmError_windows.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2026, 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
@@ -24,6 +24,7 @@
 
 #include "cds/aotMetaspace.hpp"
 #include "cds/cdsConfig.hpp"
+#include "cppstdlib/cstdlib.hpp"
 #include "runtime/arguments.hpp"
 #include "runtime/javaThread.hpp"
 #include "runtime/os.hpp"
diff --git a/src/hotspot/os_cpu/bsd_aarch64/os_bsd_aarch64.cpp b/src/hotspot/os_cpu/bsd_aarch64/os_bsd_aarch64.cpp
index f6e2d39e315..62dba218b2f 100644
--- a/src/hotspot/os_cpu/bsd_aarch64/os_bsd_aarch64.cpp
+++ b/src/hotspot/os_cpu/bsd_aarch64/os_bsd_aarch64.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2026, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2014, Red Hat Inc. All rights reserved.
  * Copyright (c) 2021, Azul Systems, Inc. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
@@ -29,6 +29,7 @@
 #include "classfile/vmSymbols.hpp"
 #include "code/codeCache.hpp"
 #include "code/vtableStubs.hpp"
+#include "cppstdlib/cstdlib.hpp"
 #include "interpreter/interpreter.hpp"
 #include "jvm.h"
 #include "logging/log.hpp"
@@ -63,7 +64,6 @@
 # include <signal.h>
 # include <errno.h>
 # include <dlfcn.h>
-# include <stdlib.h>
 # include <stdio.h>
 # include <unistd.h>
 # include <sys/resource.h>
diff --git a/src/hotspot/os_cpu/bsd_x86/os_bsd_x86.cpp b/src/hotspot/os_cpu/bsd_x86/os_bsd_x86.cpp
index 420e7b4cd8d..f1c80594eaf 100644
--- a/src/hotspot/os_cpu/bsd_x86/os_bsd_x86.cpp
+++ b/src/hotspot/os_cpu/bsd_x86/os_bsd_x86.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2026, 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
@@ -26,6 +26,7 @@
 #include "classfile/vmSymbols.hpp"
 #include "code/codeCache.hpp"
 #include "code/vtableStubs.hpp"
+#include "cppstdlib/cstdlib.hpp"
 #include "interpreter/interpreter.hpp"
 #include "jvm.h"
 #include "logging/log.hpp"
@@ -58,7 +59,6 @@
 # include <signal.h>
 # include <errno.h>
 # include <dlfcn.h>
-# include <stdlib.h>
 # include <stdio.h>
 # include <unistd.h>
 # include <sys/resource.h>
diff --git a/src/hotspot/os_cpu/linux_aarch64/os_linux_aarch64.cpp b/src/hotspot/os_cpu/linux_aarch64/os_linux_aarch64.cpp
index e565f353382..da9e7e159f1 100644
--- a/src/hotspot/os_cpu/linux_aarch64/os_linux_aarch64.cpp
+++ b/src/hotspot/os_cpu/linux_aarch64/os_linux_aarch64.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2026, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2014, Red Hat Inc. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -28,6 +28,7 @@
 #include "code/codeCache.hpp"
 #include "code/vtableStubs.hpp"
 #include "code/nativeInst.hpp"
+#include "cppstdlib/cstdlib.hpp"
 #include "interpreter/interpreter.hpp"
 #include "jvm.h"
 #include "memory/allocation.inline.hpp"
@@ -59,7 +60,6 @@
 # include <signal.h>
 # include <errno.h>
 # include <dlfcn.h>
-# include <stdlib.h>
 # include <stdio.h>
 # include <unistd.h>
 # include <sys/resource.h>
diff --git a/src/hotspot/os_cpu/linux_arm/os_linux_arm.cpp b/src/hotspot/os_cpu/linux_arm/os_linux_arm.cpp
index f4196d89fe3..41a4dbea384 100644
--- a/src/hotspot/os_cpu/linux_arm/os_linux_arm.cpp
+++ b/src/hotspot/os_cpu/linux_arm/os_linux_arm.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2026, 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
@@ -25,6 +25,7 @@
 #include "asm/assembler.inline.hpp"
 #include "classfile/vmSymbols.hpp"
 #include "code/vtableStubs.hpp"
+#include "cppstdlib/cstdlib.hpp"
 #include "interpreter/interpreter.hpp"
 #include "jvm.h"
 #include "memory/allocation.inline.hpp"
@@ -57,7 +58,6 @@
 # include <signal.h>
 # include <errno.h>
 # include <dlfcn.h>
-# include <stdlib.h>
 # include <stdio.h>
 # include <unistd.h>
 # include <sys/resource.h>
diff --git a/src/hotspot/os_cpu/linux_ppc/os_linux_ppc.cpp b/src/hotspot/os_cpu/linux_ppc/os_linux_ppc.cpp
index 5909b5799b9..6854fb805a9 100644
--- a/src/hotspot/os_cpu/linux_ppc/os_linux_ppc.cpp
+++ b/src/hotspot/os_cpu/linux_ppc/os_linux_ppc.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2026, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2012, 2025 SAP SE. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -28,6 +28,7 @@
 #include "classfile/vmSymbols.hpp"
 #include "code/codeCache.hpp"
 #include "code/vtableStubs.hpp"
+#include "cppstdlib/cstdlib.hpp"
 #include "interpreter/interpreter.hpp"
 #include "jvm.h"
 #include "memory/allocation.inline.hpp"
@@ -62,7 +63,6 @@
 # include <signal.h>
 # include <errno.h>
 # include <dlfcn.h>
-# include <stdlib.h>
 # include <stdio.h>
 # include <unistd.h>
 # include <sys/resource.h>
diff --git a/src/hotspot/os_cpu/linux_riscv/os_linux_riscv.cpp b/src/hotspot/os_cpu/linux_riscv/os_linux_riscv.cpp
index 7a5929b0f41..d4a306d35b1 100644
--- a/src/hotspot/os_cpu/linux_riscv/os_linux_riscv.cpp
+++ b/src/hotspot/os_cpu/linux_riscv/os_linux_riscv.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2026, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2020, 2022, Huawei Technologies Co., Ltd. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -28,6 +28,7 @@
 #include "code/codeCache.hpp"
 #include "code/nativeInst.hpp"
 #include "code/vtableStubs.hpp"
+#include "cppstdlib/cstdlib.hpp"
 #include "interpreter/interpreter.hpp"
 #include "jvm.h"
 #include "memory/allocation.inline.hpp"
@@ -61,7 +62,6 @@
 # include <pthread.h>
 # include <signal.h>
 # include <stdio.h>
-# include <stdlib.h>
 # include <sys/mman.h>
 # include <sys/resource.h>
 # include <sys/socket.h>
diff --git a/src/hotspot/os_cpu/linux_s390/os_linux_s390.cpp b/src/hotspot/os_cpu/linux_s390/os_linux_s390.cpp
index 4e074512e34..9982b5860a8 100644
--- a/src/hotspot/os_cpu/linux_s390/os_linux_s390.cpp
+++ b/src/hotspot/os_cpu/linux_s390/os_linux_s390.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2026, 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.
  *
@@ -30,6 +30,7 @@
 #include "code/nativeInst.hpp"
 #include "code/vtableStubs.hpp"
 #include "compiler/disassembler.hpp"
+#include "cppstdlib/cstdlib.h"
 #include "interpreter/interpreter.hpp"
 #include "jvm.h"
 #include "memory/allocation.inline.hpp"
@@ -62,7 +63,6 @@
 # include <signal.h>
 # include <errno.h>
 # include <dlfcn.h>
-# include <stdlib.h>
 # include <stdio.h>
 # include <unistd.h>
 # include <sys/resource.h>
diff --git a/src/hotspot/os_cpu/linux_x86/os_linux_x86.cpp b/src/hotspot/os_cpu/linux_x86/os_linux_x86.cpp
index a7f4e5ef688..07f53582a76 100644
--- a/src/hotspot/os_cpu/linux_x86/os_linux_x86.cpp
+++ b/src/hotspot/os_cpu/linux_x86/os_linux_x86.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2026, 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
@@ -26,6 +26,7 @@
 #include "classfile/vmSymbols.hpp"
 #include "code/codeCache.hpp"
 #include "code/vtableStubs.hpp"
+#include "cppstdlib/cstdlib.hpp"
 #include "interpreter/interpreter.hpp"
 #include "jvm.h"
 #include "logging/log.hpp"
@@ -59,7 +60,6 @@
 # include <signal.h>
 # include <errno.h>
 # include <dlfcn.h>
-# include <stdlib.h>
 # include <stdio.h>
 # include <unistd.h>
 # include <sys/resource.h>
diff --git a/src/hotspot/os_cpu/windows_aarch64/os_windows_aarch64.cpp b/src/hotspot/os_cpu/windows_aarch64/os_windows_aarch64.cpp
index d99e0167cbd..2c2afb168fd 100644
--- a/src/hotspot/os_cpu/windows_aarch64/os_windows_aarch64.cpp
+++ b/src/hotspot/os_cpu/windows_aarch64/os_windows_aarch64.cpp
@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2020, Microsoft Corporation. All rights reserved.
- * Copyright (c) 2022, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2022, 2026, 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
@@ -28,6 +28,7 @@
 #include "code/codeCache.hpp"
 #include "code/vtableStubs.hpp"
 #include "code/nativeInst.hpp"
+#include "cppstdlib/cstdlib.hpp"
 #include "interpreter/interpreter.hpp"
 #include "jvm.h"
 #include "memory/allocation.inline.hpp"
@@ -54,7 +55,6 @@
 # include <sys/types.h>
 # include <signal.h>
 # include <errno.h>
-# include <stdlib.h>
 # include <stdio.h>
 # include <intrin.h>
 
diff --git a/src/hotspot/share/classfile/classLoader.cpp b/src/hotspot/share/classfile/classLoader.cpp
index 12fbda899b9..d9a63cd154b 100644
--- a/src/hotspot/share/classfile/classLoader.cpp
+++ b/src/hotspot/share/classfile/classLoader.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2026, 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
@@ -42,6 +42,7 @@
 #include "classfile/vmClasses.hpp"
 #include "classfile/vmSymbols.hpp"
 #include "compiler/compileBroker.hpp"
+#include "cppstdlib/cstdlib.hpp"
 #include "interpreter/bytecodeStream.hpp"
 #include "interpreter/oopMapCache.hpp"
 #include "jimage.hpp"
@@ -81,7 +82,6 @@
 #include "utilities/utf8.hpp"
 
 #include <ctype.h>
-#include <stdlib.h>
 
 // Entry point in java.dll for path canonicalization
 
diff --git a/src/hotspot/share/cppstdlib/cstdlib.hpp b/src/hotspot/share/cppstdlib/cstdlib.hpp
new file mode 100644
index 00000000000..2b58e737882
--- /dev/null
+++ b/src/hotspot/share/cppstdlib/cstdlib.hpp
@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2025, 2026, 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
+ * 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.
+ *
+ */
+
+#ifndef SHARE_CPPSTDLIB_CSTDLIB_HPP
+#define SHARE_CPPSTDLIB_CSTDLIB_HPP
+
+#include "utilities/compilerWarnings.hpp"
+
+// HotSpot usage for <cstdlib>:
+//
+// Some functions are explicitly forbidden below. That may not be a complete
+// list of all the functions we should forbid.
+//
+// We assume <cstdlib> provides definitions in the global namespace, in
+// addition to providing them in the std namespace. We prefer to use the names
+// in the global namespace.
+
+BEGIN_ALLOW_FORBIDDEN_FUNCTIONS
+#include "utilities/vmassert_uninstall.hpp"
+
+#include <cstdlib>
+
+#include "utilities/vmassert_reinstall.hpp" // don't reorder
+END_ALLOW_FORBIDDEN_FUNCTIONS
+
+// AIX may define malloc and calloc as macros when certain other features are
+// present, causing us all sorts of grief.
+// https://www.ibm.com/docs/en/openxl-c-and-cpp-aix/17.1.4?topic=compilers-memory-allocation
+// Replace the macro definitions with something we can work with.
+// AIX 7.3 no longer uses macro renaming when building with clang, instead
+// using the same asm replacement approach as used below.  This workaround can
+// be removed once earlier versions are no longer supported as build platforms.
+#if defined(AIX) && (defined(__VEC__) || defined(__AIXVEC))
+#if defined(malloc) || defined(calloc)
+#if !defined(malloc) || !defined(calloc)
+#error "Inconsistent alloc macro mappings, expected both to be mapped."
+#endif
+// Remove the macros.
+#undef malloc
+#undef calloc
+// Implement the mapping using gcc/clang asm name mapping.
+extern "C" {
+extern void* malloc(size_t) noexcept asm("vec_malloc");
+extern void* calloc(size_t, size_t) noexcept asm("vec_calloc");
+} // extern "C"
+// Because the macros are in place when <cstdlib> brings names into the std
+// namespace, macro replacement causes the expanded names to be added instead
+// of the intended names. We can't remove std::vec_malloc and std::vec_calloc,
+// but we do add the standard names in case someone uses them.
+namespace std {
+using ::malloc;
+using ::calloc;
+} // namespace std
+#endif // Macro definition for malloc or calloc
+#endif // AIX altivec allocator support
+
+// Prefer os:: variants of these.
+FORBID_IMPORTED_NORETURN_C_FUNCTION(void exit(int), noexcept, "use os::exit")
+FORBID_IMPORTED_NORETURN_C_FUNCTION(void _Exit(int), noexcept, "use os::exit")
+
+// Windows puts _exit in <stdlib.h>. POSIX puts it in <unistd.h>.
+// We can't forbid it here when using clang if it's not in <stdlib.h> - see
+// the clang definition for FORBIDDEN_FUNCTION_NORETURN_ATTRIBUTE.
+#ifdef _WINDOWS
+FORBID_IMPORTED_NORETURN_C_FUNCTION(void _exit(int), /* not noexcept */, "use os::exit")
+#endif // _WINDOWS
+
+// These functions return raw C-heap pointers or, in case of free(), take raw
+// C-heap pointers.  We generally want allocation to be done through NMT, using
+// os::malloc and friends.
+FORBID_IMPORTED_C_FUNCTION(void* malloc(size_t), noexcept, "use os::malloc");
+FORBID_IMPORTED_C_FUNCTION(void free(void*), noexcept, "use os::free");
+FORBID_IMPORTED_C_FUNCTION(void* calloc(size_t, size_t), noexcept, "use os::malloc and zero out manually");
+FORBID_IMPORTED_C_FUNCTION(void* realloc(void*, size_t), noexcept, "use os::realloc");
+
+// These are not provided (and are unimplementable?) by Windows.
+// https://stackoverflow.com/questions/62962839/stdaligned-alloc-missing-from-visual-studio-2019
+// They also aren't useful for a POSIX implementation of NMT.
+#ifndef _WINDOWS
+FORBID_C_FUNCTION(void* aligned_alloc(size_t, size_t), noexcept, "don't use");
+FORBID_C_FUNCTION(int posix_memalign(void**, size_t, size_t), noexcept, "don't use");
+#endif // !_WINDOWS
+
+#endif // SHARE_CPPSTDLIB_CSTDLIB_HPP
diff --git a/src/hotspot/share/utilities/byteswap.hpp b/src/hotspot/share/utilities/byteswap.hpp
index 371095bce49..9fc367c784e 100644
--- a/src/hotspot/share/utilities/byteswap.hpp
+++ b/src/hotspot/share/utilities/byteswap.hpp
@@ -1,4 +1,5 @@
 /*
+ * Copyright (c) 2025, 2026, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2023, 2024, Google and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -141,7 +142,7 @@ struct ByteswapImpl : public ByteswapFallbackImpl<T, N> {};
  *****************************************************************************/
 #elif defined(TARGET_COMPILER_visCPP)
 
-#include <cstdlib>
+#include "cppstdlib/cstdlib.hpp"
 
 #pragma intrinsic(_byteswap_ushort)
 #pragma intrinsic(_byteswap_ulong)
diff --git a/src/hotspot/share/utilities/forbiddenFunctions.hpp b/src/hotspot/share/utilities/forbiddenFunctions.hpp
index 47becd7b4c7..9d1b88e6233 100644
--- a/src/hotspot/share/utilities/forbiddenFunctions.hpp
+++ b/src/hotspot/share/utilities/forbiddenFunctions.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2024, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2024, 2026, 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
@@ -32,12 +32,6 @@
 #include <stdarg.h>
 #include <stddef.h>
 
-// Workaround for noreturn functions: exit, _exit, _Exit - see the clang
-// definition of FORBIDDEN_FUNCTION_NORETURN_ATTRIBUTE.
-#ifdef __clang__
-#include <stdlib.h>
-#endif
-
 #ifdef _WINDOWS
 #include "forbiddenFunctions_windows.hpp"
 #else
@@ -49,12 +43,6 @@
 // or have security concerns, either with preferred alternatives, or to be
 // avoided entirely.
 
-FORBID_IMPORTED_NORETURN_C_FUNCTION(void exit(int), noexcept, "use os::exit")
-FORBID_IMPORTED_NORETURN_C_FUNCTION(void _Exit(int), noexcept, "use os::exit")
-
-// Windows puts _exit in <stdlib.h>, POSIX in <unistd.h>.
-FORBID_IMPORTED_NORETURN_C_FUNCTION(void _exit(int), /* not noexcept */, "use os::exit")
-
 FORBID_IMPORTED_C_FUNCTION(char* strerror(int), noexcept, "use os::strerror");
 FORBID_IMPORTED_C_FUNCTION(char* strtok(char*, const char*), noexcept, "use strtok_r");
 
@@ -70,13 +58,8 @@ FORBID_C_FUNCTION(int vsprintf(char*, const char*, va_list), noexcept, "use os::
 FORBID_C_FUNCTION(int vsnprintf(char*, size_t, const char*, va_list), noexcept, "use os::vsnprintf");
 PRAGMA_DIAG_POP
 
-// All of the following functions return raw C-heap pointers (sometimes as an
-// option, e.g. realpath or getwd) or, in case of free(), take raw C-heap
-// pointers.  We generally want allocation to be done through NMT.
-FORBID_IMPORTED_C_FUNCTION(void* malloc(size_t size), noexcept, "use os::malloc");
-FORBID_IMPORTED_C_FUNCTION(void free(void *ptr), noexcept, "use os::free");
-FORBID_IMPORTED_C_FUNCTION(void* calloc(size_t nmemb, size_t size), noexcept, "use os::malloc and zero out manually");
-FORBID_IMPORTED_C_FUNCTION(void* realloc(void *ptr, size_t size), noexcept, "use os::realloc");
+// All of the following functions return raw C-heap pointers.  We generally
+// want allocation to be done through NMT.
 FORBID_IMPORTED_C_FUNCTION(char* strdup(const char *s), noexcept, "use os::strdup");
 FORBID_IMPORTED_C_FUNCTION(wchar_t* wcsdup(const wchar_t *s), noexcept, "don't use");
 
diff --git a/src/hotspot/share/utilities/globalDefinitions_gcc.hpp b/src/hotspot/share/utilities/globalDefinitions_gcc.hpp
index f82f9b1386a..302a62de6c1 100644
--- a/src/hotspot/share/utilities/globalDefinitions_gcc.hpp
+++ b/src/hotspot/share/utilities/globalDefinitions_gcc.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2026, 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
@@ -31,6 +31,8 @@
 // globally used constants & types, class (forward)
 // declarations and a few frequently used utility functions.
 
+#include "cppstdlib/cstdlib.hpp"
+
 #include <alloca.h>
 #include <ctype.h>
 #include <dlfcn.h>
@@ -44,15 +46,6 @@
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
-#include <stdlib.h>
-// In stdlib.h on AIX malloc is defined as a macro causing
-// compiler errors when resolving them in different depths as it
-// happens in the log tags. This avoids the macro.
-#if (defined(__VEC__) || defined(__AIXVEC)) && defined(AIX) \
-    && defined(__open_xl_version__) && __open_xl_version__ >= 17
-  #undef malloc
-  extern void *malloc(size_t) asm("vec_malloc");
-#endif
 #include <string.h>
 #include <time.h>
 #include <wchar.h>
diff --git a/src/hotspot/share/utilities/globalDefinitions_visCPP.hpp b/src/hotspot/share/utilities/globalDefinitions_visCPP.hpp
index b9d25096cd5..dfd6f2f1880 100644
--- a/src/hotspot/share/utilities/globalDefinitions_visCPP.hpp
+++ b/src/hotspot/share/utilities/globalDefinitions_visCPP.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2026, 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
@@ -34,6 +34,8 @@
 // Need this on windows to get the math constants (e.g., M_PI).
 #define _USE_MATH_DEFINES
 
+#include "cppstdlib/cstdlib.hpp"
+
 # include <ctype.h>
 # include <fcntl.h>
 # include <float.h> // for _isnan
@@ -45,7 +47,6 @@
 # include <stddef.h>// for offsetof
 # include <stdint.h>
 # include <stdio.h>
-# include <stdlib.h>
 # include <string.h>
 # include <sys/stat.h>
 # include <time.h>
diff --git a/src/hotspot/share/utilities/parseInteger.hpp b/src/hotspot/share/utilities/parseInteger.hpp
index 3e3eafada87..8840275a8cb 100644
--- a/src/hotspot/share/utilities/parseInteger.hpp
+++ b/src/hotspot/share/utilities/parseInteger.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2026, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2022 SAP SE. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -26,6 +26,7 @@
 #ifndef SHARE_UTILITIES_PARSE_INTEGER_HPP
 #define SHARE_UTILITIES_PARSE_INTEGER_HPP
 
+#include "cppstdlib/cstdlib.hpp"
 #include "cppstdlib/limits.hpp"
 #include "metaprogramming/enableIf.hpp"
 #include "utilities/debug.hpp"
@@ -33,7 +34,6 @@
 #include "utilities/macros.hpp"
 
 #include <errno.h>
-#include <stdlib.h>
 
 // *************************************************************************
 // ** Attention compatibility!                                            **
diff --git a/src/hotspot/share/utilities/permitForbiddenFunctions.hpp b/src/hotspot/share/utilities/permitForbiddenFunctions.hpp
index 1ba42f8e386..71719ac8a76 100644
--- a/src/hotspot/share/utilities/permitForbiddenFunctions.hpp
+++ b/src/hotspot/share/utilities/permitForbiddenFunctions.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2024, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2024, 2026, 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
@@ -25,6 +25,7 @@
 #ifndef SHARE_UTILITIES_PERMITFORBIDDENFUNCTIONS_HPP
 #define SHARE_UTILITIES_PERMITFORBIDDENFUNCTIONS_HPP
 
+#include "cppstdlib/cstdlib.hpp"
 #include "utilities/compilerWarnings.hpp"
 #include "utilities/globalDefinitions.hpp"
 
@@ -34,6 +35,9 @@
 #include "permitForbiddenFunctions_posix.hpp"
 #endif
 
+#include <stdio.h>
+#include <string.h>
+
 // Provide wrappers for some functions otherwise forbidden from use in HotSpot.
 //
 // There may be special circumstances where an otherwise forbidden function
@@ -53,7 +57,6 @@ namespace permit_forbidden_function {
 BEGIN_ALLOW_FORBIDDEN_FUNCTIONS
 
 [[noreturn]] inline void exit(int status) { ::exit(status); }
-[[noreturn]] inline void _exit(int status) { ::_exit(status); }
 
 ATTRIBUTE_PRINTF(3, 0)
 inline int vsnprintf(char* str, size_t size, const char* format, va_list ap) {
diff --git a/test/hotspot/gtest/gtestMain.cpp b/test/hotspot/gtest/gtestMain.cpp
index 842b6547b48..a1869ab5499 100644
--- a/test/hotspot/gtest/gtestMain.cpp
+++ b/test/hotspot/gtest/gtestMain.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2026, 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
@@ -22,6 +22,7 @@
  *
  */
 
+#include "cppstdlib/cstdlib.hpp"
 #include "jni.h"
 #include "runtime/os.hpp"
 #include "runtime/thread.inline.hpp"
@@ -31,7 +32,6 @@
 
 #include <stdio.h>
 #include <string.h>
-#include <stdlib.h>
 #ifdef __APPLE__
 #include <dlfcn.h>
 #endif
diff --git a/test/hotspot/gtest/unittest.hpp b/test/hotspot/gtest/unittest.hpp
index 336a2f0766e..6a2cd400cb6 100644
--- a/test/hotspot/gtest/unittest.hpp
+++ b/test/hotspot/gtest/unittest.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2026, 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
@@ -24,9 +24,9 @@
 #ifndef UNITTEST_HPP
 #define UNITTEST_HPP
 
+#include "cppstdlib/cstdlib.hpp"
 #include "utilities/globalDefinitions.hpp"
 
-#include <stdlib.h>
 #include <stdio.h>
 
 #define GTEST_DONT_DEFINE_TEST 1
diff --git a/test/hotspot/gtest/utilities/test_bitMap_setops.cpp b/test/hotspot/gtest/utilities/test_bitMap_setops.cpp
index 2b1e67533df..1def9c89cfc 100644
--- a/test/hotspot/gtest/utilities/test_bitMap_setops.cpp
+++ b/test/hotspot/gtest/utilities/test_bitMap_setops.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2026, 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
@@ -21,6 +21,7 @@
  * questions.
  */
 
+#include "cppstdlib/cstdlib.hpp"
 #include "runtime/os.hpp"
 #include "utilities/align.hpp"
 #include "utilities/bitMap.inline.hpp"
@@ -29,8 +30,6 @@
 #include "utilities/globalDefinitions.hpp"
 #include "unittest.hpp"
 
-#include <stdlib.h>
-
 typedef BitMap::idx_t idx_t;
 typedef BitMap::bm_word_t bm_word_t;