From 42dc5356388ad4c5a92c5a9cb36ab083ca8f63e6 Mon Sep 17 00:00:00 2001
From: georgemoralis <giorgosmrls@gmail.com>
Date: Mon, 10 Jul 2023 14:52:14 +0300
Subject: [PATCH] some more work on linker and added some more needed (but not
 currently used) memory functions

---
 src/Core/Memory.cpp     | 52 +++++++++++++++++++++++++++++++++++++++++
 src/Core/Memory.h       |  3 +++
 src/Core/PS4/Linker.cpp | 13 ++++++-----
 3 files changed, 62 insertions(+), 6 deletions(-)

diff --git a/src/Core/Memory.cpp b/src/Core/Memory.cpp
index 39449176..0855df7f 100644
--- a/src/Core/Memory.cpp
+++ b/src/Core/Memory.cpp
@@ -42,6 +42,17 @@ namespace Memory
 					return PAGE_NOACCESS;
 			}
 		}
+        static MemoryMode convertMemoryMode(u32 mode) {
+            switch (mode) {
+                case PAGE_NOACCESS: return MemoryMode::NoAccess;
+                case PAGE_READONLY: return MemoryMode::Read;
+                case PAGE_READWRITE: return MemoryMode::ReadWrite;
+                case PAGE_EXECUTE: return MemoryMode::Execute;
+                case PAGE_EXECUTE_READ: return MemoryMode::ExecuteRead;
+                case PAGE_EXECUTE_READWRITE: return MemoryMode::ExecuteReadWrite;
+                default: return MemoryMode::NoAccess;
+            }
+        }
 
 		u64 memory_alloc(u64 address, u64 size, MemoryMode mode)
 		{
@@ -71,5 +82,46 @@ namespace Memory
 			#endif
 			return ptr;
 		}
+        bool memory_protect(u64 address, u64 size, MemoryMode mode, MemoryMode* old_mode) {
+            DWORD old_protect = 0;
+            if (VirtualProtect(reinterpret_cast<LPVOID>(static_cast<uintptr_t>(address)), size, convertMemoryMode(mode), &old_protect) == 0) {
+                    auto err = static_cast<u32>(GetLastError());
+                    LOG_ERROR_IF(true, "VirtualProtect() failed: 0x{:X}\n", err);
+                    return false;
+            }
+            if (old_mode != nullptr) {
+                    *old_mode = convertMemoryMode(old_protect);
+            }
+            return true;
+        }
+
+		bool memory_flush(u64 address, u64 size) {
+            if (::FlushInstructionCache(GetCurrentProcess(), reinterpret_cast<LPVOID>(static_cast<uintptr_t>(address)), size) == 0) {
+                    auto err = static_cast<u32>(GetLastError());
+                    LOG_ERROR_IF(true, "FlushInstructionCache() failed: 0x{:X}\n", err);
+                    return false;
+            }
+            return true;
+        }
+        bool memory_patch(u64 vaddr, u64 value) {
+            MemoryMode old_mode{};
+            memory_protect(vaddr, 8, MemoryMode::ReadWrite, &old_mode);
+
+            auto* ptr = reinterpret_cast<uint64_t*>(vaddr);
+
+            bool ret = (*ptr != value);
+
+            *ptr = value;
+
+            memory_protect(vaddr, 8, old_mode, nullptr);
+
+			//if mode is executable flush it so insure that cpu finds it
+			if ((old_mode == MemoryMode::Execute || old_mode == MemoryMode::ExecuteRead || old_mode == MemoryMode::ExecuteWrite ||
+                 old_mode == MemoryMode::ExecuteReadWrite)) {
+                    memory_flush(vaddr, 8);
+            }
+
+            return ret;
+        }
 	}
 }
diff --git a/src/Core/Memory.h b/src/Core/Memory.h
index 7bc5ba0f..00b9d2ba 100644
--- a/src/Core/Memory.h
+++ b/src/Core/Memory.h
@@ -20,5 +20,8 @@ namespace Memory
 
 	namespace VirtualMemory {
 		u64 memory_alloc(u64 address, u64 size, MemoryMode mode);
+		bool memory_protect(u64 address, u64 size, MemoryMode mode, MemoryMode* old_mode);
+        bool memory_flush(u64 address, u64 size);
+        bool memory_patch(u64 vaddr, u64 value);
 	}
 }
\ No newline at end of file
diff --git a/src/Core/PS4/Linker.cpp b/src/Core/PS4/Linker.cpp
index efa3bc15..d1922c52 100644
--- a/src/Core/PS4/Linker.cpp
+++ b/src/Core/PS4/Linker.cpp
@@ -511,6 +511,7 @@ static void relocate(u32 idx, elf_relocation* rel, Module* m, bool isJmpRel)
 	bool  rel_isResolved = false;
 	u08   rel_sym_type = 0;
 	std::string rel_name;
+    u08 rel_bind_type = -1;//-1 means it didn't resolve
 
 	switch (type)
 	{
@@ -544,12 +545,12 @@ static void relocate(u32 idx, elf_relocation* rel, Module* m, bool isJmpRel)
 			switch (sym_bind)
 			{
 			case STB_GLOBAL:
-				if (type == R_X86_64_64) {
-					LOG_INFO_IF(debug_loader, "R_X86_64_64 sym_type {} bind STB_GLOBAL symbol : {:#010x}\n", sym_type,symbol);
-				}
-				if (type == R_X86_64_JUMP_SLOT) {
-					LOG_INFO_IF(debug_loader, "R_X86_64_JUMP_SLOT sym_type {} bind STB_GLOBAL symbol : {:#010x}\n", sym_type,symbol);
-				}
+                    rel_bind_type = STB_GLOBAL;
+                    rel_name = namesTlb + sym.st_name;
+                    if (type == R_X86_64_JUMP_SLOT) {
+                      addend = 0;
+                    }
+                    LOG_INFO_IF(debug_loader, "R_X86_64_64-R_X86_64_JUMP_SLOT sym_type {} bind STB_GLOBAL symbol : {:#010x}\n", sym_type, symbol);
 				break;
 			default:
 				LOG_INFO_IF(debug_loader, "UNK bind {}\n", sym_bind);