GameList: Fix scanning of ELF files

src/core/game_list.cpp

@@ -11,6 +11,7 @@
 #include "system.h"
 
 #include "util/cd_image.h"
+#include "util/elf_file.h"
 #include "util/http_downloader.h"
 #include "util/image.h"
 #include "util/ini_settings_interface.h"
@@ -199,6 +200,18 @@ bool GameList::GetExeListEntry(const std::string& path, GameList::Entry* entry)
     // Who knows
     entry->region = DiscRegion::Other;
   }
+  else if (StringUtil::EndsWithNoCase(filename, ".elf"))
+  {
+    ELFFile::Elf32_Ehdr header;
+    if (std::fread(&header, sizeof(header), 1, fp.get()) != 1 || !ELFFile::IsValidElfHeader(header))
+    {
+      WARNING_LOG("{} is not a valid ELF.", path);
+      return false;
+    }
+
+    // Who knows
+    entry->region = DiscRegion::Other;
+  }
   else
   {
     BIOS::PSEXEHeader header;

src/util/elf_file.cpp

@@ -9,6 +9,7 @@
 
 LOG_CHANNEL(FileLoader);
 
+static constexpr const u8 EXPECTED_ELF_HEADER[4] = {'\177', 'E', 'L', 'F'};
 static constexpr s64 MAX_ELF_FILE_SIZE = 32 * 1024 * 1024;
 
 ELFFile::ELFFile() = default;
@@ -113,9 +114,8 @@ bool ELFFile::Open(DataArray data, Error* error)
 {
   m_data = std::move(data);
 
-  static constexpr const u8 EXPECTED_HEADER[4] = {'\177', 'E', 'L', 'F'};
-
-  if (m_data.size() < sizeof(Elf32_Ehdr) || std::memcmp(m_data.data(), EXPECTED_HEADER, sizeof(EXPECTED_HEADER)) != 0)
+  if (m_data.size() < sizeof(Elf32_Ehdr) ||
+      std::memcmp(m_data.data(), EXPECTED_ELF_HEADER, sizeof(EXPECTED_ELF_HEADER)) != 0)
   {
     Error::SetStringView(error, "Invalid header.");
     return false;
@@ -202,3 +202,32 @@ bool ELFFile::LoadExecutableSections(const LoadExecutableSectionCallback& callba
 
   return true;
 }
+
+bool ELFFile::IsValidElfHeader(const std::span<const u8> data, Error* error /*= nullptr*/)
+{
+  if (data.size() < sizeof(Elf32_Ehdr))
+  {
+    Error::SetStringView(error, "Invalid header.");
+    return false;
+  }
+
+  return IsValidElfHeader(reinterpret_cast<const Elf32_Ehdr&>(*data.data()), error);
+}
+
+bool ELFFile::IsValidElfHeader(const Elf32_Ehdr& header, Error* error /* = nullptr */)
+{
+  if (std::memcmp(header.e_ident, EXPECTED_ELF_HEADER, sizeof(EXPECTED_ELF_HEADER)) != 0)
+  {
+    Error::SetStringView(error, "Invalid header.");
+    return false;
+  }
+
+  if (header.e_machine != EM_MIPS)
+  {
+    Error::SetStringFmt(error, "Unsupported machine type {}.", header.e_machine);
+    return false;
+  }
+
+  // probably fine
+  return true;
+}

src/util/elf_file.h

@@ -94,6 +94,9 @@ class ELFFile
   ELFFile();
   ~ELFFile();
 
+  static bool IsValidElfHeader(const std::span<const u8> data, Error* error = nullptr);
+  static bool IsValidElfHeader(const Elf32_Ehdr& header, Error* error = nullptr);
+
   const Elf32_Ehdr& GetELFHeader() const;
   u32 GetEntryPoint() const;