From 047f445651360cc735a206f81a7a658fd9d01871 Mon Sep 17 00:00:00 2001
From: apio <blobs.trading@gmail.com>
Date: Sat, 19 Nov 2022 18:38:47 +0100
Subject: [PATCH] Kernel: Add helpers to validate memory addresses

---
 kernel/src/memory/MemoryManager.cpp | 15 +++++++++++++++
 kernel/src/memory/MemoryManager.h   |  3 +++
 2 files changed, 18 insertions(+)

diff --git a/kernel/src/memory/MemoryManager.cpp b/kernel/src/memory/MemoryManager.cpp
index 74357446..c8ce477b 100644
--- a/kernel/src/memory/MemoryManager.cpp
+++ b/kernel/src/memory/MemoryManager.cpp
@@ -184,6 +184,21 @@ namespace MemoryManager
         return {};
     }
 
+    bool validate_readable_page(u64 address)
+    {
+        auto rc = MMU::get_flags(address);
+        if (rc.has_error()) return false;
+        return true;
+    }
+
+    bool validate_writable_page(u64 address)
+    {
+        auto rc = MMU::get_flags(address);
+        if (rc.has_error()) return false;
+        if (rc.release_value() & MMU::ReadWrite) return true;
+        return false;
+    }
+
     u64 free()
     {
         return free_mem;
diff --git a/kernel/src/memory/MemoryManager.h b/kernel/src/memory/MemoryManager.h
index d1ca0f5f..6250b863 100644
--- a/kernel/src/memory/MemoryManager.h
+++ b/kernel/src/memory/MemoryManager.h
@@ -17,6 +17,9 @@ namespace MemoryManager
     Result<void> remap(u64 address, usize count, int flags);
     Result<void> remap_unaligned(u64 address, usize count, int flags);
 
+    bool validate_readable_page(u64 address);
+    bool validate_writable_page(u64 address);
+
     u64 free();
     u64 used();
     u64 reserved();