1 files changed, 69 insertions, 0 deletions
diff --git a/src/VBox/Runtime/r0drv/nt/alloca-x86-r0drv-nt.asm b/src/VBox/Runtime/r0drv/nt/alloca-x86-r0drv-nt.asm
new file mode 100644
index 00000000..cf241ad3
--- /dev/null
+++ b/src/VBox/Runtime/r0drv/nt/alloca-x86-r0drv-nt.asm
@@ -0,0 +1,69 @@
+; $Id: alloca-x86-r0drv-nt.asm $
+;; @file
+; IPRT - Visual C++ __alloca__probe_16.
+;
+
+;
+; Copyright (C) 2020-2022 Oracle and/or its affiliates.
+;
+; This file is part of VirtualBox base platform packages, as
+; available from https://www.virtualbox.org.
+;
+; This program is free software; you can redistribute it and/or
+; modify it under the terms of the GNU General Public License
+; as published by the Free Software Foundation, in version 3 of the
+; License.
+;
+; This program 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 for more details.
+;
+; You should have received a copy of the GNU General Public License
+; along with this program; if not, see <https://www.gnu.org/licenses>.
+;
+; The contents of this file may alternatively be used under the terms
+; of the Common Development and Distribution License Version 1.0
+; (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
+; in the VirtualBox distribution, in which case the provisions of the
+; CDDL are applicable instead of those of the GPL.
+;
+; You may elect to license modified versions of this file under the
+; terms and conditions of either the GPL or the CDDL or both.
+;
+; SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
+;
+
+;*******************************************************************************
+;* Header Files                                                                *
+;*******************************************************************************
+%include "iprt/asmdefs.mac"
+
+BEGINCODE
+
+;;
+; @returns  esp with eax subtracted and aligned to 16 bytes.
+; @param    eax allocation size.
+;
+BEGINPROC _alloca_probe_16
+        ; Sanitycheck the input.
+%ifdef DEBUG
+        cmp     eax, 0
+        jne     .not_zero
+        int3
+.not_zero:
+        cmp     eax, 4096
+        jbe     .four_kb_or_less
+        int3
+.four_kb_or_less:
+%endif
+
+        ; Don't bother probing the stack as the allocation is supposed to be
+        ; a lot smaller than 4KB.
+        neg     eax
+        lea     eax, [esp + eax + 4]
+        and     eax, 0fffffff0h
+        xchg    eax, esp
+        jmp     [eax]
+ENDPROC _alloca_probe_16
+