From b0a7fd4e072434d910600c62e7ce7199a2c70c81 Mon Sep 17 00:00:00 2001
From: Exzap <13877693+Exzap@users.noreply.github.com>
Date: Wed, 18 Oct 2023 10:49:12 +0200
Subject: [PATCH] Set default alignment for SysAllocator to cache-line size

Avoids memory corruptions when the memory is cleared via DCZeroRange. Seen in BotW with AX AUX buffers.
---
 src/Common/SysAllocator.h | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/src/Common/SysAllocator.h b/src/Common/SysAllocator.h
index 7930a16b3..7a11601e3 100644
--- a/src/Common/SysAllocator.h
+++ b/src/Common/SysAllocator.h
@@ -1,10 +1,10 @@
 #pragma once
 
-#include <vector>
-
 uint32 coreinit_allocFromSysArea(uint32 size, uint32 alignment);
 class SysAllocatorBase;
 
+#define SYSALLOCATOR_GUARDS		0	// if 1, create a magic constant at the top of each memory allocation which is used to check for memory corruption
+
 class SysAllocatorContainer
 {
 public:
@@ -29,9 +29,7 @@ class SysAllocatorBase
 	virtual void Initialize() = 0;
 };
 
-
-
-template<typename T, size_t count = 1, size_t alignment = 8>
+template<typename T, size_t count = 1, size_t alignment = 32>
 class SysAllocator : public SysAllocatorBase
 {
 public:
@@ -68,11 +66,17 @@ class SysAllocator : public SysAllocatorBase
 
 	T* GetPtr() const
 	{
+#if SYSALLOCATOR_GUARDS
+		cemu_assert(*(uint32*)((uint8*)m_sysMem.GetPtr()+(sizeof(T) * count)) == 0x112A33C4);
+#endif
 		return m_sysMem.GetPtr();
 	}
 
 	uint32 GetMPTR() const
 	{
+#if SYSALLOCATOR_GUARDS
+		cemu_assert(*(uint32*)((uint8*)m_sysMem.GetPtr()+(sizeof(T) * count)) == 0x112A33C4);
+#endif
 		return m_sysMem.GetMPTR();
 	}
 
@@ -130,11 +134,17 @@ class SysAllocator : public SysAllocatorBase
 	{
 		if (m_sysMem.GetMPTR() != 0)
 			return;
-
 		// alloc mem
-		m_sysMem = { coreinit_allocFromSysArea(sizeof(T) * count, alignment) };
+		uint32 guardSize = 0;
+#if SYSALLOCATOR_GUARDS
+		guardSize = 4;
+#endif
+		m_sysMem = { coreinit_allocFromSysArea(sizeof(T) * count + guardSize, alignment) };
 		// copy temp buffer to mem and clear it
 		memcpy(m_sysMem.GetPtr(), m_tempData.data(), sizeof(T)*count);
+#if SYSALLOCATOR_GUARDS
+		*(uint32*)((uint8*)m_sysMem.GetPtr()+(sizeof(T) * count)) = 0x112A33C4;
+#endif
 		m_tempData.clear();
 	}
 
@@ -197,9 +207,8 @@ class SysAllocator<T, 1> : public SysAllocatorBase
 	{
 		if (m_sysMem.GetMPTR() != 0)
 			return;
-
 		// alloc mem
-		m_sysMem = { coreinit_allocFromSysArea(sizeof(T), 8) };
+		m_sysMem = { coreinit_allocFromSysArea(sizeof(T), 32) };
 		// copy temp buffer to mem and clear it
 		*m_sysMem = m_tempData;
 	}