From 5b03e248b7c88e7ac0266ba33fd25ca8b4cd7f15 Mon Sep 17 00:00:00 2001
From: ziggoon <zackmusgrave20@gmail.com>
Date: Tue, 4 Mar 2025 22:10:49 -0600
Subject: [PATCH] add FFI & wrappers for NtAllocateVirtualMemory &
 NtFreeVirtualMemory + add missing alloction constants MEM_RESERVE_PLACEHOLDER
 / MEM_PRESERVE_PLACEHOLDER

---
 lib/std/os/windows.zig       | 34 ++++++++++++++++++++++++++++++++++
 lib/std/os/windows/ntdll.zig | 17 +++++++++++++++++
 2 files changed, 51 insertions(+)

diff --git a/lib/std/os/windows.zig b/lib/std/os/windows.zig
index 563b24cf83c390c6a62355c8b258423e685529fb..c29eb0f05a1442817ea294b4ff4bdd1a174e4040 100644
--- a/lib/std/os/windows.zig
+++ b/lib/std/os/windows.zig
@@ -1758,6 +1758,38 @@ pub fn TerminateProcess(hProcess: HANDLE, uExitCode: UINT) TerminateProcessError
     }
 }
 
+pub const NtAllocateVirtualMemoryError = error{
+    AccessDenied,
+    InvalidParameter,
+    NoMemory,
+    Unexpected,
+};
+
+pub fn NtAllocateVirtualMemory(hProcess: HANDLE, addr: ?*PVOID, zero_bits: ULONG_PTR, size: ?*SIZE_T, alloc_type: ULONG, protect: ULONG) NtAllocateVirtualMemoryError!void {
+    return switch (ntdll.NtAllocateVirtualMemory(hProcess, addr, zero_bits, size, alloc_type, protect)) {
+        .SUCCESS => return,
+        .ACCESS_DENIED => NtAllocateVirtualMemoryError.AccessDenied,
+        .INVALID_PARAMETER => NtAllocateVirtualMemoryError.InvalidParameter,
+        .NO_MEMORY => NtAllocateVirtualMemoryError.NoMemory,
+        else => |st| unexpectedStatus(st),
+    };
+}
+
+pub const NtFreeVirtualMemoryError = error{
+    AccessDenied,
+    InvalidParameter,
+    Unexpected,
+};
+
+pub fn NtFreeVirtualMemory(hProcess: HANDLE, addr: ?*PVOID, size: *SIZE_T, free_type: ULONG) NtFreeVirtualMemoryError!void {
+    return switch (ntdll.NtFreeVirtualMemory(hProcess, addr, size, free_type)) {
+        .SUCCESS => return,
+        .ACCESS_DENIED => NtFreeVirtualMemoryError.AccessDenied,
+        .INVALID_PARAMETER => NtFreeVirtualMemoryError.InvalidParameter,
+        else => NtFreeVirtualMemoryError.Unexpected,
+    };
+}
+
 pub const VirtualAllocError = error{Unexpected};
 
 pub fn VirtualAlloc(addr: ?LPVOID, size: usize, alloc_type: DWORD, flProtect: DWORD) VirtualAllocError!LPVOID {
@@ -3539,6 +3571,8 @@ pub const MEM_LARGE_PAGES = 0x20000000;
 pub const MEM_PHYSICAL = 0x400000;
 pub const MEM_TOP_DOWN = 0x100000;
 pub const MEM_WRITE_WATCH = 0x200000;
+pub const MEM_RESERVE_PLACEHOLDER = 0x00040000;
+pub const MEM_PRESERVE_PLACEHOLDER = 0x00000400;
 
 // Protect values
 pub const PAGE_EXECUTE = 0x10;
diff --git a/lib/std/os/windows/ntdll.zig b/lib/std/os/windows/ntdll.zig
index 490deaeacc5fe0df5a528ab595ece254c44a3d22..474aea3330c7a23c2a236238ce3fc3e8b1244655 100644
--- a/lib/std/os/windows/ntdll.zig
+++ b/lib/std/os/windows/ntdll.zig
@@ -5,6 +5,7 @@ const BOOL = windows.BOOL;
 const DWORD = windows.DWORD;
 const DWORD64 = windows.DWORD64;
 const ULONG = windows.ULONG;
+const ULONG_PTR = windows.ULONG_PTR;
 const NTSTATUS = windows.NTSTATUS;
 const WORD = windows.WORD;
 const HANDLE = windows.HANDLE;
@@ -358,3 +359,19 @@ pub extern "ntdll" fn NtCreateNamedPipeFile(
     OutboundQuota: ULONG,
     DefaultTimeout: *LARGE_INTEGER,
 ) callconv(.winapi) NTSTATUS;
+
+pub extern "ntdll" fn NtAllocateVirtualMemory(
+    ProcessHandle: HANDLE,
+    BaseAddress: ?*PVOID,
+    ZeroBits: ULONG_PTR,
+    RegionSize: ?*SIZE_T,
+    AllocationType: ULONG,
+    PageProtection: ULONG,
+) callconv(.winapi) NTSTATUS;
+
+pub extern "ntdll" fn NtFreeVirtualMemory(
+    ProcessHandle: HANDLE,
+    BaseAddress: ?*PVOID,
+    RegionSize: *SIZE_T,
+    FreeType: ULONG,
+) callconv(.winapi) NTSTATUS;
-- 
2.54.0