From feadea0e91ab4eb6e6c0c79e9bb63c9f2551fec4 Mon Sep 17 00:00:00 2001
From: Bananymous <oskari.alaranta@bananymous.com>
Date: Tue, 13 Aug 2024 23:44:17 +0300
Subject: [PATCH] Kernel: Fix AML unaligned integer reads and buffer shifts
 over 32

---
 kernel/include/kernel/ACPI/AML/Buffer.h  |  6 ++---
 kernel/include/kernel/ACPI/AML/Integer.h | 29 +++++++++++++++---------
 2 files changed, 21 insertions(+), 14 deletions(-)

diff --git a/kernel/include/kernel/ACPI/AML/Buffer.h b/kernel/include/kernel/ACPI/AML/Buffer.h
index 8b428d62..b1fd7911 100644
--- a/kernel/include/kernel/ACPI/AML/Buffer.h
+++ b/kernel/include/kernel/ACPI/AML/Buffer.h
@@ -38,7 +38,7 @@ namespace Kernel::ACPI::AML
 		{
 			uint64_t value = 0;
 			for (size_t i = 0; i < BAN::Math::min<size_t>(buffer.size(), 8); i++)
-				value |= buffer[i] << (8 * i);
+				value |= static_cast<uint64_t>(buffer[i]) << (8 * i);
 			return MUST(BAN::RefPtr<Integer>::create(value));
 		}
 
@@ -119,7 +119,7 @@ namespace Kernel::ACPI::AML
 			for (size_t i = 0; i < BAN::Math::min<size_t>(field_bit_size, 64); i++)
 			{
 				const size_t bit = field_bit_offset + i;
-				value |= ((buffer[bit / 8] >> (bit % 8)) & 1) << i;
+				value |= static_cast<uint64_t>((buffer[bit / 8] >> (bit % 8)) & 1) << i;
 			}
 
 			return MUST(BAN::RefPtr<Integer>::create(value));
@@ -140,7 +140,7 @@ namespace Kernel::ACPI::AML
 			for (size_t i = 0; i < field_bit_size; i++)
 			{
 				const size_t bit = field_bit_offset + i;
-				value |= ((buffer[bit / 8] >> (bit % 8)) & 1) << i;
+				value |= static_cast<uint64_t>((buffer[bit / 8] >> (bit % 8)) & 1) << i;
 			}
 
 			return MUST(BAN::RefPtr<AML::Integer>::create(value));
diff --git a/kernel/include/kernel/ACPI/AML/Integer.h b/kernel/include/kernel/ACPI/AML/Integer.h
index c9457724..baa223a1 100644
--- a/kernel/include/kernel/ACPI/AML/Integer.h
+++ b/kernel/include/kernel/ACPI/AML/Integer.h
@@ -1,6 +1,5 @@
 #pragma once
 
-#include <BAN/Endianness.h>
 #include <BAN/Optional.h>
 #include <BAN/String.h>
 #include <BAN/Vector.h>
@@ -94,7 +93,7 @@ namespace Kernel::ACPI::AML
 				{
 					if (aml_data.size() < 2)
 						return ParseResult::Failure;
-					uint8_t value = aml_data[1];
+					const uint8_t value = aml_data[1];
 					aml_data = aml_data.slice(2);
 					return ParseResult(MUST(BAN::RefPtr<Integer>::create(value)));
 				}
@@ -102,9 +101,9 @@ namespace Kernel::ACPI::AML
 				{
 					if (aml_data.size() < 3)
 						return ParseResult::Failure;
-					uint16_t value = BAN::little_endian_to_host<uint16_t>(
-						*reinterpret_cast<const uint16_t*>(&aml_data[1])
-					);
+					uint16_t value = 0;
+					value |= aml_data[1] << 0;
+					value |= aml_data[2] << 8;
 					aml_data = aml_data.slice(3);
 					return ParseResult(MUST(BAN::RefPtr<Integer>::create(value)));
 				}
@@ -112,9 +111,11 @@ namespace Kernel::ACPI::AML
 				{
 					if (aml_data.size() < 5)
 						return ParseResult::Failure;
-					uint32_t value = BAN::little_endian_to_host<uint32_t>(
-						*reinterpret_cast<const uint32_t*>(&aml_data[1])
-					);
+					uint32_t value = 0;
+					value |= static_cast<uint32_t>(aml_data[1]) <<  0;
+					value |= static_cast<uint32_t>(aml_data[2]) <<  8;
+					value |= static_cast<uint32_t>(aml_data[3]) << 16;
+					value |= static_cast<uint32_t>(aml_data[4]) << 24;
 					aml_data = aml_data.slice(5);
 					return ParseResult(MUST(BAN::RefPtr<Integer>::create(value)));
 				}
@@ -122,9 +123,15 @@ namespace Kernel::ACPI::AML
 				{
 					if (aml_data.size() < 9)
 						return ParseResult::Failure;
-					uint64_t value = BAN::little_endian_to_host<uint64_t>(
-						*reinterpret_cast<const uint64_t*>(&aml_data[1])
-					);
+					uint64_t value = 0;
+					value |= static_cast<uint64_t>(aml_data[1]) <<  0;
+					value |= static_cast<uint64_t>(aml_data[2]) <<  8;
+					value |= static_cast<uint64_t>(aml_data[3]) << 16;
+					value |= static_cast<uint64_t>(aml_data[4]) << 24;
+					value |= static_cast<uint64_t>(aml_data[5]) << 32;
+					value |= static_cast<uint64_t>(aml_data[6]) << 40;
+					value |= static_cast<uint64_t>(aml_data[7]) << 48;
+					value |= static_cast<uint64_t>(aml_data[8]) << 56;
 					aml_data = aml_data.slice(9);
 					return ParseResult(MUST(BAN::RefPtr<Integer>::create(value)));
 				}