Add getVmtSection() method to dynamic library classes

danielkrupinski · Jul 13, 2023 · 81fd6aa · 81fd6aa
1 parent 07d60d6
commit 81fd6aa
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Showing 3 changed files with 28 additions and 2 deletions.
diff --git a/Source/Platform/Linux/LinuxDynamicLibrary.h b/Source/Platform/Linux/LinuxDynamicLibrary.h
@@ -41,6 +41,17 @@ class LinuxDynamicLibrary {
     }
 
     [[nodiscard]] MemorySection getCodeSection() const noexcept
+    {
+        return getSection(".text");
+    }
+
+    [[nodiscard]] MemorySection getVmtSection() const noexcept
+    {
+        return getSection(".data.rel.ro");
+    }
+
+private:
+    [[nodiscard]] MemorySection getSection(const char* sectionName) const noexcept
     {
         void* base = nullptr;
         std::size_t size = 0;
@@ -57,7 +68,7 @@ class LinuxDynamicLibrary {
                         for (auto i = 0; i < ehdr->e_shnum; ++i) {
                             const auto shdr = (ElfW(Shdr)*)(std::uintptr_t(shdrs) + i * ehdr->e_shentsize);
 
-                            if (std::strcmp(strTab + shdr->sh_name, ".text") != 0)
+                            if (std::strcmp(strTab + shdr->sh_name, sectionName) != 0)
                                 continue;
 
                             base = (void*)(linkMap->l_addr + shdr->sh_offset);
@@ -75,7 +86,6 @@ class LinuxDynamicLibrary {
         return MemorySection{ std::span{ reinterpret_cast<const std::byte*>(base), size } };
     }
 
-private:
     [[nodiscard]] void* getModuleHandle(const char* libraryName)
     {
         const auto handle = PlatformApi::dlopen(libraryName, RTLD_LAZY | RTLD_NOLOAD);

diff --git a/Source/Platform/Windows/PortableExecutable.h b/Source/Platform/Windows/PortableExecutable.h
@@ -27,6 +27,15 @@ class PortableExecutable {
         return {};
     }
 
+    [[nodiscard]] MemorySection getVmtSection() const noexcept
+    {
+        for (const auto& section : getSectionHeaders()) {
+            if ((section.Characteristics & IMAGE_SCN_MEM_READ) != 0 && std::memcmp(section.Name, ".rdata", 6) == 0)
+                return MemorySection{ std::span{ base + section.VirtualAddress, section.Misc.VirtualSize } };
+        }
+        return {};
+    }
+
     [[nodiscard]] SafeAddress getExport(const char* name) const noexcept
     {
         const auto exportDataDirectory = getExportDataDirectory();

diff --git a/Source/Platform/Windows/WindowsDynamicLibrary.h b/Source/Platform/Windows/WindowsDynamicLibrary.h
@@ -34,6 +34,13 @@ class WindowsDynamicLibrary {
         return {};
     }
 
+    [[nodiscard]] MemorySection getVmtSection() const noexcept
+    {
+        if (handle)
+            return portableExecutable().getVmtSection();
+        return {};
+    }
+
     [[nodiscard]] HMODULE getHandle() const noexcept
     {
         return handle;