From 841584ccbd15b128214df51c7f206ac5b1299f24 Mon Sep 17 00:00:00 2001
From: Bananymous <bananymousosq@gmail.com>
Date: Tue, 6 Jun 2023 02:03:23 +0300
Subject: [PATCH] Kernel: get_free_contiguous_pages works with non-page aligned
 addresses

also fix bug in ordering
---
 kernel/arch/x86_64/PageTable.cpp | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/kernel/arch/x86_64/PageTable.cpp b/kernel/arch/x86_64/PageTable.cpp
index dae2c104..071d3355 100644
--- a/kernel/arch/x86_64/PageTable.cpp
+++ b/kernel/arch/x86_64/PageTable.cpp
@@ -188,9 +188,6 @@ namespace Kernel
 	{
 		LockGuard _(m_lock);
 
-		ASSERT(is_canonical(vaddr));
-		vaddr = uncanonicalize(vaddr);
-
 		vaddr &= PAGE_ADDR_MASK;
 
 		if (is_page_free(vaddr))
@@ -199,6 +196,9 @@ namespace Kernel
 			return;
 		}
 
+		ASSERT(is_canonical(vaddr));
+		vaddr = uncanonicalize(vaddr);
+
 		uint64_t pml4e = (vaddr >> 39) & 0x1FF;
 		uint64_t pdpte = (vaddr >> 30) & 0x1FF;
 		uint64_t pde   = (vaddr >> 21) & 0x1FF;
@@ -384,7 +384,8 @@ namespace Kernel
 
 	vaddr_t PageTable::get_free_contiguous_pages(size_t page_count, vaddr_t first_address) const
 	{
-		ASSERT(first_address % PAGE_SIZE == 0);
+		if (first_address % PAGE_SIZE)
+			first_address = (first_address + PAGE_SIZE - 1) & PAGE_ADDR_MASK;
 
 		LockGuard _(m_lock);