From 56616f832e1e28f228f26e96028bc56b770224d5 Mon Sep 17 00:00:00 2001
From: georgemoralis <giorgosmrls@gmail.com>
Date: Wed, 5 Apr 2023 20:21:44 +0300
Subject: [PATCH] finished elf header validation

---
 emulator/Loader/Elf.cpp | 65 +++++++++++++++++++++++++++++++++++++++--
 emulator/Loader/Elf.h   | 37 ++++++++++++++++++-----
 2 files changed, 91 insertions(+), 11 deletions(-)

diff --git a/emulator/Loader/Elf.cpp b/emulator/Loader/Elf.cpp
index dc6c9c15..b783dc60 100644
--- a/emulator/Loader/Elf.cpp
+++ b/emulator/Loader/Elf.cpp
@@ -151,10 +151,69 @@ bool Elf::isElfFile() const
     {
         return false;
     }
-    if (m_elf_header->e_ident[0] != '\x7f' || m_elf_header->e_ident[1] != '\x45' || m_elf_header->e_ident[2] != '\x4c' ||
-        m_elf_header->e_ident[3] != '\x46')
+    if (m_elf_header->e_ident[EI_MAG0] != ELFMAG0 || m_elf_header->e_ident[EI_MAG1] != ELFMAG1 || m_elf_header->e_ident[EI_MAG2] != ELFMAG2 ||
+        m_elf_header->e_ident[EI_MAG3] != ELFMAG3)
     {
-        printf("Not an ELF file magic is wrong!\n");
+        printf("ERROR:Not an ELF file magic is wrong!\n");
+        return false;
+    }
+    if (m_elf_header->e_ident[EI_CLASS] != ELFCLASS64)
+    {
+        printf("ERROR:e_ident[EI_CLASS] expected 0x02 is (0x%x)\n", m_elf_header->e_ident[EI_CLASS]);
+        return false;
+    }
+
+    if (m_elf_header->e_ident[EI_DATA] != ELFDATA2LSB)
+    {
+        printf("ERROR:e_ident[EI_DATA] expected 0x01 is (0x%x)\n", m_elf_header->e_ident[EI_DATA]);
+        return false;
+    }
+
+    if (m_elf_header->e_ident[EI_VERSION] != EV_CURRENT)
+    {
+        printf("ERROR:e_ident[EI_VERSION] expected 0x01 is (0x%x)\n", m_elf_header->e_ident[EI_VERSION]);
+        return false;
+    }
+
+    if (m_elf_header->e_ident[EI_OSABI] != ELFOSABI_FREEBSD)
+    {
+        printf("ERROR:e_ident[EI_OSABI] expected 0x09 is (0x%x)\n", m_elf_header->e_ident[EI_OSABI]);
+        return false;
+    }
+
+    if (m_elf_header->e_ident[EI_ABIVERSION] != ELFABIVERSION_AMDGPU_HSA_V2)
+    {
+        printf("ERROR:e_ident[EI_ABIVERSION] expected 0x00 is (0x%x)\n", m_elf_header->e_ident[EI_ABIVERSION]);
+        return false;
+    }
+
+    if (m_elf_header->e_type != ET_DYNEXEC && m_elf_header->e_type != ET_DYNAMIC)
+    {
+        printf("ERROR:e_type expected 0xFE10 OR 0xFE18 is (%04x)\n", m_elf_header->e_type);
+        return false;
+    }
+
+    if (m_elf_header->e_machine != EM_X86_64)
+    {
+        printf("ERROR:e_machine expected 0x3E is (%04x)\n", m_elf_header->e_machine);
+        return false;
+    }
+
+    if (m_elf_header->e_version != EV_CURRENT)
+    {
+        printf("ERROR:m_elf_header->e_version expected 0x01 is (0x%x)\n", m_elf_header->e_version);
+        return false;
+    }
+
+    if (m_elf_header->e_phentsize != sizeof(elf_program_header))
+    {
+        printf("ERROR:e_phentsize (%d) != sizeof(elf_program_header)\n", m_elf_header->e_phentsize);
+        return false;
+    }
+
+    if (m_elf_header->e_shentsize > 0 && m_elf_header->e_shentsize != sizeof(elf_section_header)) //commercial games doesn't appear to have section headers
+    {
+        printf("ERROR:e_shentsize (%d) != sizeof(elf_section_header)\n", m_elf_header->e_shentsize);
         return false;
     }
 
diff --git a/emulator/Loader/Elf.h b/emulator/Loader/Elf.h
index 5740535f..bcc40d4c 100644
--- a/emulator/Loader/Elf.h
+++ b/emulator/Loader/Elf.h
@@ -34,14 +34,35 @@ struct self_segment_header
 };
 
 
-constexpr 	int EI_MAG0 = 0;/* e_ident[] indexes */
-constexpr 	int EI_MAG2 = 2;
-constexpr 	int EI_MAG3 = 3;
-constexpr 	int EI_CLASS = 4;
-constexpr 	int EI_DATA = 5;
-constexpr 	int EI_VERSION = 6;
-constexpr 	int EI_OSABI = 7;
-constexpr	int EI_PAD = 8;
+constexpr u08 EI_MAG0 = 0;/* e_ident[] indexes */
+constexpr u08 EI_MAG1 = 1;
+constexpr u08 EI_MAG2 = 2;
+constexpr u08 EI_MAG3 = 3;
+constexpr u08 EI_CLASS = 4;
+constexpr u08 EI_DATA = 5;
+constexpr u08 EI_VERSION = 6;
+constexpr u08 EI_OSABI = 7;
+constexpr u08 EI_ABIVERSION = 8;
+
+// Magic number
+constexpr u08 ELFMAG0 = 0x7F;
+constexpr u08 ELFMAG1 = 'E';
+constexpr u08 ELFMAG2 = 'L';
+constexpr u08 ELFMAG3 = 'F';
+
+//other ident fields , only ps4 neccesary ones
+constexpr u08 ELFCLASS64 = 2;
+constexpr u08 ELFDATA2LSB = 1;
+constexpr u08 ELFOSABI_FREEBSD = 9;  // FreeBSD
+constexpr u08 EV_CURRENT = 1;
+constexpr u08 ELFABIVERSION_AMDGPU_HSA_V2 = 0;
+
+//type fields PS4 specific
+constexpr u16 ET_DYNEXEC = 0xFE10; // Executable file
+constexpr u16 ET_DYNAMIC = 0xFE18; // Shared
+
+//machine field
+constexpr u16 EM_X86_64 = 62; // Advanced Micro Devices X86-64 processor
 
 struct elf_header
 {