fix: split files, add padding and return checking on disasm

CMakeLists.txt

@@ -18,6 +18,8 @@ endif()
 
 add_library(radhook
     src/radhook.cpp
+    src/memory.cpp
+    src/x64disasm.cpp
 )
 
 target_include_directories(radhook

include/radhook/api.h

@@ -41,6 +41,7 @@ enum class RadHookResult : int {
     InvalidDetour,
     InvalidHandle,
     TrampolineTooFar,
+    TargetTooSmall,
     Unknown,
 };
 

include/radhook/defines.h

@@ -0,0 +1,46 @@
+#ifndef __LIBRADHOOK_DEFINES_HPP__
+#define __LIBRADHOOK_DEFINES_HPP__
+
+#include <cstdint>
+#include <cstddef>
+
+#include <type_traits>
+
+// platform detection
+#if !defined(RADIUM_PLATFORM_WINDOWS) && !defined(RADIUM_PLATFORM_ANDROID)
+# if defined(_WIN32) || defined(_WIN64)
+#  define RADIUM_PLATFORM_WINDOWS 1
+# elif defined(__ANDROID__)
+#  define RADIUM_PLATFORM_ANDROID 1
+# else
+#  error "radhook: unsupported platform -- define RADIUM_PLATFORM_WINDOWS or RADIUM_PLATFORM_ANDROID"
+# endif
+#endif
+
+// architecture detection
+#if defined(_M_X64) || defined(__x86_64__)
+# define RADHOOK_ARCH_X64 1
+#elif defined(_M_ARM64) || defined(__aarch64__)
+# define RADHOOK_ARCH_ARM64 1
+#else
+# error "radhook: unsupported architecture -- need x86-64 or aarch64"
+#endif
+
+// api macros
+#if defined(_WIN32)
+# if defined(RADHOOK_BUILD)
+#  define RADHOOK_API __declspec(dllexport)
+# elif defined(RADHOOK_SHARED)
+#  define RADHOOK_API __declspec(dllimport)
+# else
+#  define RADHOOK_API
+# endif
+#else
+# if defined(__GNUC__) || defined(__clang__)
+#  define RADHOOK_API __attribute__((visibility("default")))
+# else
+#  define RADHOOK_API
+# endif
+#endif
+
+#endif // __LIBRADHOOK_DEFINES_HPP__

include/radhook/private/disassemble.h

@@ -0,0 +1,57 @@
+#ifndef __LIBRADHOOK_PRIVATE_DISASSEMBLE_H__
+#define __LIBRADHOOK_PRIVATE_DISASSEMBLE_H__
+
+#include "radhook/defines.h"
+
+#if defined(RADIUM_PLATFORM_WINDOWS)
+# ifndef WIN32_LEAN_AND_MEAN
+#  define WIN32_LEAN_AND_MEAN
+# endif
+# include <windows.h>
+#elif defined(RADIUM_PLATFORM_ANDROID)
+# include <sys/mman.h>
+# include <unistd.h>
+#endif
+
+#if defined(RADHOOK_ARCH_X64)
+struct X64Insn {
+    size_t length = 0;
+    bool ripRelative = false;
+    size_t dispOffset = 0;
+    bool relativeControlFlow = false;
+    bool isReturn = false;
+    bool isPadding = false;
+    bool valid = false;
+};
+
+X64Insn 
+DecodeX64(
+    const uint8_t* p, 
+    size_t avail
+    );
+
+constexpr size_t kX64StubLen = 14;      // FF25 00000000 + imm64
+constexpr size_t kX64MaxStolen = 32;
+constexpr size_t kX64MaxRipFixups = 8;
+
+enum class StolenBytesError {
+    None,
+    BadDecode,
+    RelativeControlFlow,
+    TooManyRipFixups,
+    ExceedsMaxStolen,
+    InsufficientLength,
+};
+
+StolenBytesError 
+BuildStolenBytesX64(
+    const uint8_t* target, 
+    size_t minLen,
+    uint8_t* outBytes, 
+    size_t& outLen,
+    size_t* outRipOffsets, 
+    size_t& outRipCount
+    );
+
+#endif // defined(RADHOOK_ARCH_X64)
+#endif // __LIBRADHOOK_PRIVATE_DISASSEMBLE_H__

include/radhook/private/memory.h

@@ -0,0 +1,102 @@
+#ifndef __LIBRADHOOK_PRIVATE_MEMORY_H__
+#define __LIBRADHOOK_PRIVATE_MEMORY_H__
+
+#include "radhook/defines.h"
+
+#if defined(RADIUM_PLATFORM_WINDOWS)
+# ifndef WIN32_LEAN_AND_MEAN
+#  define WIN32_LEAN_AND_MEAN
+# endif
+# include <windows.h>
+#elif defined(RADIUM_PLATFORM_ANDROID)
+# include <sys/mman.h>
+# include <unistd.h>
+#endif
+
+#if defined(RADIUM_PLATFORM_WINDOWS)
+
+size_t 
+RadMemoryPageSize();
+
+void* 
+RadAllocExec(
+    size_t size
+    );
+
+void* 
+RadAllocExecNear(
+    void* target, 
+    size_t size
+    );
+
+void 
+RadFreeExec(
+    void* p, 
+    size_t size
+    );
+
+bool 
+RadMakeWritableExecutable(
+    void* addr, 
+    size_t size, 
+    unsigned long* oldProtect
+    );
+
+void 
+RadRestoreMemoryProtection(
+    void* addr, 
+    size_t size, 
+    unsigned long oldProtect
+    );
+
+void 
+RadFlushICache(
+    void* addr, 
+    size_t size
+    );
+
+#elif defined(RADIUM_PLATFORM_ANDROID)
+
+size_t 
+RadMemoryPageSize();
+
+void* 
+RadAllocExec(
+    size_t size
+    );
+
+void* 
+RadAllocExecNear(
+    void* target, 
+    size_t size
+    );
+
+void 
+RadFreeExec(
+    void* p, 
+    size_t size
+    );
+
+bool 
+RadMakeWritableExecutable(
+    void* addr, 
+    size_t size, 
+    unsigned long* oldProtect
+    );
+
+void 
+RadRestoreMemoryProtection(
+    void* addr, 
+    size_t size, 
+    unsigned long oldProtect
+    );
+
+void 
+RadFlushICache(
+    void* addr, 
+    size_t size
+    );
+
+#endif
+
+#endif // __LIBRADHOOK_PRIVATE_MEMORY_H__

include/radhook/radhook.h

@@ -1,48 +1,7 @@
 #ifndef __LIBRADHOOK_HPP__
 #define __LIBRADHOOK_HPP__
 
-#include <cstdint>
-#include <cstddef>
-
-#include <type_traits>
-
-// platform detection
-#if !defined(RADIUM_PLATFORM_WINDOWS) && !defined(RADIUM_PLATFORM_ANDROID)
-# if defined(_WIN32) || defined(_WIN64)
-#  define RADIUM_PLATFORM_WINDOWS 1
-# elif defined(__ANDROID__)
-#  define RADIUM_PLATFORM_ANDROID 1
-# else
-#  error "radhook: unsupported platform -- define RADIUM_PLATFORM_WINDOWS or RADIUM_PLATFORM_ANDROID"
-# endif
-#endif
-
-// architecture detection
-#if defined(_M_X64) || defined(__x86_64__)
-# define RADHOOK_ARCH_X64 1
-#elif defined(_M_ARM64) || defined(__aarch64__)
-# define RADHOOK_ARCH_ARM64 1
-#else
-# error "radhook: unsupported architecture -- need x86-64 or aarch64"
-#endif
-
-// api macros
-#if defined(_WIN32)
-# if defined(RADHOOK_BUILD)
-#  define RADHOOK_API __declspec(dllexport)
-# elif defined(RADHOOK_SHARED)
-#  define RADHOOK_API __declspec(dllimport)
-# else
-#  define RADHOOK_API
-# endif
-#else
-# if defined(__GNUC__) || defined(__clang__)
-#  define RADHOOK_API __attribute__((visibility("default")))
-# else
-#  define RADHOOK_API
-# endif
-#endif
-
+#include "defines.h"
 #include "api.h"
 
 #endif // __LIBRADHOOK_HPP__

src/memory.cpp

@@ -0,0 +1,218 @@
+#include "radhook/private/memory.h"
+
+#if defined(RADIUM_PLATFORM_WINDOWS)
+# ifndef WIN32_LEAN_AND_MEAN
+#  define WIN32_LEAN_AND_MEAN
+# endif
+# include <windows.h>
+#elif defined(RADIUM_PLATFORM_ANDROID)
+# include <sys/mman.h>
+# include <unistd.h>
+#endif
+
+// platform memory backend
+#if defined(RADIUM_PLATFORM_WINDOWS)
+
+size_t RadMemoryPageSize() {
+    static size_t sz = [] {
+        SYSTEM_INFO si;
+        GetSystemInfo(&si);
+        return static_cast<size_t>(si.dwPageSize);
+    }();
+
+    return sz;
+}
+
+void* RadAllocExec(size_t size) {
+    return VirtualAlloc(nullptr, size, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);
+}
+
+void RadFreeExec(void* p, size_t /*size*/) {
+    if (p) VirtualFree(p, 0, MEM_RELEASE);
+}
+
+void* RadAllocExecNear(void* target, size_t size) {
+    SYSTEM_INFO si;
+    GetSystemInfo(&si);
+    const uintptr_t pageSize = si.dwPageSize;
+    const uintptr_t targetAddr = reinterpret_cast<uintptr_t>(target);
+    const uintptr_t margin = 0x7FFF0000ULL; // stay safely under INT32_MAX
+
+    uintptr_t minAddr = reinterpret_cast<uintptr_t>(si.lpMinimumApplicationAddress);
+    uintptr_t maxAddr = reinterpret_cast<uintptr_t>(si.lpMaximumApplicationAddress);
+    if (targetAddr > margin && targetAddr - margin > minAddr) minAddr = targetAddr - margin;
+    if (targetAddr + margin < maxAddr) maxAddr = targetAddr + margin;
+
+    uintptr_t alignedTarget = targetAddr & ~(pageSize - 1);
+
+    // search backward from target
+    for (uintptr_t addr = alignedTarget; addr >= minAddr && addr != 0; ) {
+        MEMORY_BASIC_INFORMATION mbi;
+        if (VirtualQuery(reinterpret_cast<LPCVOID>(addr), &mbi, sizeof(mbi)) == 0) break;
+        uintptr_t regionBase = reinterpret_cast<uintptr_t>(mbi.BaseAddress);
+        if (mbi.State == MEM_FREE) {
+            uintptr_t allocBase = (regionBase + pageSize - 1) & ~(pageSize - 1);
+            if (allocBase >= minAddr && allocBase + size <= regionBase + mbi.RegionSize) {
+                void* p = VirtualAlloc(reinterpret_cast<LPVOID>(allocBase), size,
+                                        MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);
+                if (p) return p;
+            }
+        }
+        if (regionBase <= minAddr || regionBase < pageSize) break;
+        addr = regionBase - pageSize;
+    }
+
+    // search forward from target
+    for (uintptr_t addr = alignedTarget; addr <= maxAddr; ) {
+        MEMORY_BASIC_INFORMATION mbi;
+        if (VirtualQuery(reinterpret_cast<LPCVOID>(addr), &mbi, sizeof(mbi)) == 0) break;
+        uintptr_t regionBase = reinterpret_cast<uintptr_t>(mbi.BaseAddress);
+        if (mbi.State == MEM_FREE) {
+            uintptr_t allocBase = (regionBase + pageSize - 1) & ~(pageSize - 1);
+            if (allocBase + size <= regionBase + mbi.RegionSize && allocBase + size <= maxAddr) {
+                void* p = VirtualAlloc(
+                    reinterpret_cast<LPVOID>(allocBase), size,
+                    MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE
+                );
+                if (p) return p;
+            }
+        }
+        if (mbi.RegionSize == 0) break;
+        addr = regionBase + mbi.RegionSize;
+    }
+
+    return nullptr;
+}
+
+bool RadMakeWritableExecutable(void* addr, size_t size, unsigned long* oldProtect) {
+    DWORD prev = 0;
+    if (!VirtualProtect(addr, size, PAGE_EXECUTE_READWRITE, &prev)) {
+        return false;
+    }
+    if (oldProtect) *oldProtect = prev;
+    return true;
+}
+
+void RadRestoreMemoryProtection(void* addr, size_t size, unsigned long oldProtect) {
+    DWORD tmp;
+    VirtualProtect(addr, size, static_cast<DWORD>(oldProtect), &tmp);
+}
+
+void RadFlushICache(void* addr, size_t size) {
+    FlushInstructionCache(GetCurrentProcess(), addr, size);
+}
+
+#elif defined(RADIUM_PLATFORM_ANDROID)
+
+size_t RadMemoryPageSize() {
+    static size_t sz = static_cast<size_t>(sysconf(_SC_PAGESIZE));
+    return sz;
+}
+
+void* RadAllocExec(size_t size) {
+    size_t pageSize = RadMemoryPageSize();
+    size_t allocSize = (size + pageSize - 1) & ~(pageSize - 1);
+    void* p = mmap(nullptr, allocSize, PROT_READ | PROT_WRITE | PROT_EXEC,
+                    MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+    return (p == MAP_FAILED) ? nullptr : p;
+}
+
+void RadFreeExec(void* p, size_t size) {
+    if (!p) return;
+    size_t pageSize = RadMemoryPageSize();
+    size_t allocSize = (size + pageSize - 1) & ~(pageSize - 1);
+    munmap(p, allocSize);
+}
+
+#ifndef MAP_FIXED_NOREPLACE
+# define MAP_FIXED_NOREPLACE 0x100000 // linux >= 4.17 defined manually for older headers
+#endif
+
+void* RadAllocExecNear(void* target, size_t size) {
+    size_t pageSize = RadMemoryPageSize();
+    uintptr_t targetAddr = reinterpret_cast<uintptr_t>(target);
+    const uintptr_t margin = 0x7FFF0000ULL;
+    uintptr_t rangeLo = (targetAddr > margin) ? targetAddr - margin : pageSize;
+    uintptr_t rangeHi = targetAddr + margin;
+
+    FILE* f = fopen("/proc/self/maps", "r");
+    if (!f) return nullptr;
+
+    struct Region { uintptr_t start, end; };
+    std::vector<Region> regions;
+    char line[512];
+    while (fgets(line, sizeof(line), f)) {
+        unsigned long long s = 0, e = 0;
+        if (sscanf(line, "%llx-%llx", &s, &e) == 2) {
+            regions.push_back({ static_cast<uintptr_t>(s), static_cast<uintptr_t>(e) });
+        }
+    }
+    fclose(f);
+    std::sort(regions.begin(), regions.end(),
+              [](const Region& a, const Region& b) { return a.start < b.start; });
+
+    std::vector<Region> gaps;
+    uintptr_t prevEnd = rangeLo;
+    for (auto& r : regions) {
+        if (r.start >= rangeHi) break;
+        uintptr_t gapStart = prevEnd;
+        uintptr_t gapEnd = std::min(r.start, rangeHi);
+        if (gapEnd > gapStart) gaps.push_back({ gapStart, gapEnd });
+        if (r.end > prevEnd) prevEnd = r.end;
+    }
+    if (prevEnd < rangeHi) gaps.push_back({ prevEnd, rangeHi });
+
+    size_t pageAlignedSize = (size + pageSize - 1) & ~(pageSize - 1);
+
+    void* best = nullptr;
+    uintptr_t bestDist = static_cast<uintptr_t>(-1);
+    for (auto& g : gaps) {
+        uintptr_t alignedStart = (g.start + pageSize - 1) & ~(pageSize - 1);
+        uintptr_t alignedEnd = g.end & ~(pageSize - 1);
+        if (alignedEnd < alignedStart + pageAlignedSize) continue;
+
+        uintptr_t lastValidStart = alignedEnd - pageAlignedSize; // already page-aligned
+        uintptr_t candidate;
+        if (targetAddr < alignedStart) candidate = alignedStart;
+        else if (targetAddr > lastValidStart) candidate = lastValidStart;
+        else candidate = targetAddr & ~(pageSize - 1);
+
+        // clamp
+        if (candidate > lastValidStart) candidate = lastValidStart;
+        if (candidate < alignedStart) candidate = alignedStart;
+
+        uintptr_t dist = (candidate > targetAddr) ? (candidate - targetAddr) : (targetAddr - candidate);
+        if (dist < bestDist) {
+            bestDist = dist;
+            best = reinterpret_cast<void*>(candidate);
+        }
+    }
+    if (!best) return nullptr;
+
+    void* p = mmap(best, pageAlignedSize, PROT_READ | PROT_WRITE | PROT_EXEC,
+                    MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED_NOREPLACE, -1, 0);
+    if (p == MAP_FAILED) return nullptr;
+    return p;
+}
+
+bool RadMakeWritableExecutable(void* addr, size_t size, unsigned long* oldProtect) {
+    if (oldProtect) *oldProtect = 0;
+    size_t pageSize = RadMemoryPageSize();
+    uintptr_t start = reinterpret_cast<uintptr_t>(addr) & ~(pageSize - 1);
+    uintptr_t end = (reinterpret_cast<uintptr_t>(addr) + size + pageSize - 1) & ~(pageSize - 1);
+    return mprotect(reinterpret_cast<void*>(start), end - start,
+                     PROT_READ | PROT_WRITE | PROT_EXEC) == 0;
+}
+
+void RadRestoreMemoryProtection(void* /*addr*/, size_t /*size*/, unsigned long /*oldProtect*/) {
+    // no-op
+}
+
+void RadFlushICache(void* addr, size_t size) {
+    __builtin___clear_cache(
+        reinterpret_cast<char*>(addr),
+        reinterpret_cast<char*>(addr) + size
+    );
+}
+
+#endif

src/radhook.cpp

@@ -1,4 +1,6 @@
 #include "radhook/radhook.h"
+#include "radhook/private/disassemble.h"
+#include "radhook/private/memory.h"
 
 #include <cstring>
 #include <cstdint>
@@ -38,6 +40,7 @@ const char* RadHookResultToString(RadHookResult result) {
         case RadHookResult::InvalidDetour:      return "InvalidDetour";
         case RadHookResult::InvalidHandle:      return "InvalidHandle";
         case RadHookResult::TrampolineTooFar:   return "TrampolineTooFar";
+        case RadHookResult::TargetTooSmall:     return "TargetTooSmall";
         default:                                return "Unknown";
     }
 }
@@ -90,374 +93,6 @@ bool IsRegisteredLocked(RadHookHandle handle) {
     return false;
 }
 
-// platform memory backend
-#if defined(RADIUM_PLATFORM_WINDOWS)
-
-void* AllocExec(size_t size) {
-    return VirtualAlloc(nullptr, size, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);
-}
-
-void FreeExec(void* p, size_t /*size*/) {
-    if (p) VirtualFree(p, 0, MEM_RELEASE);
-}
-
-void* AllocExecNear(void* target, size_t size) {
-    SYSTEM_INFO si;
-    GetSystemInfo(&si);
-    const uintptr_t pageSize = si.dwPageSize;
-    const uintptr_t targetAddr = reinterpret_cast<uintptr_t>(target);
-    const uintptr_t margin = 0x7FFF0000ULL; // stay safely under INT32_MAX
-
-    uintptr_t minAddr = reinterpret_cast<uintptr_t>(si.lpMinimumApplicationAddress);
-    uintptr_t maxAddr = reinterpret_cast<uintptr_t>(si.lpMaximumApplicationAddress);
-    if (targetAddr > margin && targetAddr - margin > minAddr) minAddr = targetAddr - margin;
-    if (targetAddr + margin < maxAddr) maxAddr = targetAddr + margin;
-
-    uintptr_t alignedTarget = targetAddr & ~(pageSize - 1);
-
-    // search backward from target
-    for (uintptr_t addr = alignedTarget; addr >= minAddr && addr != 0; ) {
-        MEMORY_BASIC_INFORMATION mbi;
-        if (VirtualQuery(reinterpret_cast<LPCVOID>(addr), &mbi, sizeof(mbi)) == 0) break;
-        uintptr_t regionBase = reinterpret_cast<uintptr_t>(mbi.BaseAddress);
-        if (mbi.State == MEM_FREE) {
-            uintptr_t allocBase = (regionBase + pageSize - 1) & ~(pageSize - 1);
-            if (allocBase >= minAddr && allocBase + size <= regionBase + mbi.RegionSize) {
-                void* p = VirtualAlloc(reinterpret_cast<LPVOID>(allocBase), size,
-                                        MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);
-                if (p) return p;
-            }
-        }
-        if (regionBase <= minAddr || regionBase < pageSize) break;
-        addr = regionBase - pageSize;
-    }
-
-    // search forward from target
-    for (uintptr_t addr = alignedTarget; addr <= maxAddr; ) {
-        MEMORY_BASIC_INFORMATION mbi;
-        if (VirtualQuery(reinterpret_cast<LPCVOID>(addr), &mbi, sizeof(mbi)) == 0) break;
-        uintptr_t regionBase = reinterpret_cast<uintptr_t>(mbi.BaseAddress);
-        if (mbi.State == MEM_FREE) {
-            uintptr_t allocBase = (regionBase + pageSize - 1) & ~(pageSize - 1);
-            if (allocBase + size <= regionBase + mbi.RegionSize && allocBase + size <= maxAddr) {
-                void* p = VirtualAlloc(
-                    reinterpret_cast<LPVOID>(allocBase), size,
-                    MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE
-                );
-                if (p) return p;
-            }
-        }
-        if (mbi.RegionSize == 0) break;
-        addr = regionBase + mbi.RegionSize;
-    }
-
-    return nullptr;
-}
-
-bool MakeWritableExecutable(void* addr, size_t size, unsigned long* oldProtect) {
-    DWORD prev = 0;
-    if (!VirtualProtect(addr, size, PAGE_EXECUTE_READWRITE, &prev)) {
-        return false;
-    }
-    if (oldProtect) *oldProtect = prev;
-    return true;
-}
-
-void RestoreProtection(void* addr, size_t size, unsigned long oldProtect) {
-    DWORD tmp;
-    VirtualProtect(addr, size, static_cast<DWORD>(oldProtect), &tmp);
-}
-
-void FlushICache(void* addr, size_t size) {
-    FlushInstructionCache(GetCurrentProcess(), addr, size);
-}
-
-#elif defined(RADIUM_PLATFORM_ANDROID)
-
-size_t PageSize() {
-    static size_t sz = static_cast<size_t>(sysconf(_SC_PAGESIZE));
-    return sz;
-}
-
-void* AllocExec(size_t size) {
-    size_t pageSize = PageSize();
-    size_t allocSize = (size + pageSize - 1) & ~(pageSize - 1);
-    void* p = mmap(nullptr, allocSize, PROT_READ | PROT_WRITE | PROT_EXEC,
-                    MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
-    return (p == MAP_FAILED) ? nullptr : p;
-}
-
-void FreeExec(void* p, size_t size) {
-    if (!p) return;
-    size_t pageSize = PageSize();
-    size_t allocSize = (size + pageSize - 1) & ~(pageSize - 1);
-    munmap(p, allocSize);
-}
-
-#ifndef MAP_FIXED_NOREPLACE
-# define MAP_FIXED_NOREPLACE 0x100000 // linux >= 4.17 defined manually for older headers
-#endif
-
-void* AllocExecNear(void* target, size_t size) {
-    size_t pageSize = PageSize();
-    uintptr_t targetAddr = reinterpret_cast<uintptr_t>(target);
-    const uintptr_t margin = 0x7FFF0000ULL;
-    uintptr_t rangeLo = (targetAddr > margin) ? targetAddr - margin : pageSize;
-    uintptr_t rangeHi = targetAddr + margin;
-
-    FILE* f = fopen("/proc/self/maps", "r");
-    if (!f) return nullptr;
-
-    struct Region { uintptr_t start, end; };
-    std::vector<Region> regions;
-    char line[512];
-    while (fgets(line, sizeof(line), f)) {
-        unsigned long long s = 0, e = 0;
-        if (sscanf(line, "%llx-%llx", &s, &e) == 2) {
-            regions.push_back({ static_cast<uintptr_t>(s), static_cast<uintptr_t>(e) });
-        }
-    }
-    fclose(f);
-    std::sort(regions.begin(), regions.end(),
-              [](const Region& a, const Region& b) { return a.start < b.start; });
-
-    std::vector<Region> gaps;
-    uintptr_t prevEnd = rangeLo;
-    for (auto& r : regions) {
-        if (r.start >= rangeHi) break;
-        uintptr_t gapStart = prevEnd;
-        uintptr_t gapEnd = std::min(r.start, rangeHi);
-        if (gapEnd > gapStart) gaps.push_back({ gapStart, gapEnd });
-        if (r.end > prevEnd) prevEnd = r.end;
-    }
-    if (prevEnd < rangeHi) gaps.push_back({ prevEnd, rangeHi });
-
-    size_t pageAlignedSize = (size + pageSize - 1) & ~(pageSize - 1);
-
-    void* best = nullptr;
-    uintptr_t bestDist = static_cast<uintptr_t>(-1);
-    for (auto& g : gaps) {
-        uintptr_t alignedStart = (g.start + pageSize - 1) & ~(pageSize - 1);
-        uintptr_t alignedEnd = g.end & ~(pageSize - 1);
-        if (alignedEnd < alignedStart + pageAlignedSize) continue;
-
-        uintptr_t lastValidStart = alignedEnd - pageAlignedSize; // already page-aligned
-        uintptr_t candidate;
-        if (targetAddr < alignedStart) candidate = alignedStart;
-        else if (targetAddr > lastValidStart) candidate = lastValidStart;
-        else candidate = targetAddr & ~(pageSize - 1);
-
-        // clamp
-        if (candidate > lastValidStart) candidate = lastValidStart;
-        if (candidate < alignedStart) candidate = alignedStart;
-
-        uintptr_t dist = (candidate > targetAddr) ? (candidate - targetAddr) : (targetAddr - candidate);
-        if (dist < bestDist) {
-            bestDist = dist;
-            best = reinterpret_cast<void*>(candidate);
-        }
-    }
-    if (!best) return nullptr;
-
-    void* p = mmap(best, pageAlignedSize, PROT_READ | PROT_WRITE | PROT_EXEC,
-                    MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED_NOREPLACE, -1, 0);
-    if (p == MAP_FAILED) return nullptr;
-    return p;
-}
-
-bool MakeWritableExecutable(void* addr, size_t size, unsigned long* oldProtect) {
-    if (oldProtect) *oldProtect = 0;
-    size_t pageSize = PageSize();
-    uintptr_t start = reinterpret_cast<uintptr_t>(addr) & ~(pageSize - 1);
-    uintptr_t end = (reinterpret_cast<uintptr_t>(addr) + size + pageSize - 1) & ~(pageSize - 1);
-    return mprotect(reinterpret_cast<void*>(start), end - start,
-                     PROT_READ | PROT_WRITE | PROT_EXEC) == 0;
-}
-
-void RestoreProtection(void* /*addr*/, size_t /*size*/, unsigned long /*oldProtect*/) {
-    // no-op
-}
-
-void FlushICache(void* addr, size_t size) {
-    __builtin___clear_cache(
-        reinterpret_cast<char*>(addr),
-        reinterpret_cast<char*>(addr) + size
-    );
-}
-
-#endif
-
-// x86-64 disassembler
-#if defined(RADHOOK_ARCH_X64)
-
-struct X64Insn {
-    size_t length = 0;
-    bool ripRelative = false;
-    size_t dispOffset = 0;
-    bool relativeControlFlow = false;
-    bool valid = false;
-};
-
-bool IsLegacyPrefix(uint8_t b) {
-    switch (b) {
-        case 0x66: case 0x67: case 0xF0: case 0xF2: case 0xF3:
-        case 0x2E: case 0x36: case 0x3E: case 0x26: case 0x64: case 0x65:
-            return true;
-        default:
-            return false;
-    }
-}
-
-X64Insn DecodeX64(const uint8_t* p, size_t avail) {
-    X64Insn insn;
-    size_t i = 0;
-    bool opSize16 = false;
-    bool rexW = false;
-
-    while (i < avail && IsLegacyPrefix(p[i])) {
-        if (p[i] == 0x66) opSize16 = true;
-        ++i;
-    }
-    if (i < avail && (p[i] & 0xF0) == 0x40) {
-        rexW = (p[i] & 0x08) != 0;
-        ++i;
-    }
-    if (i >= avail) return insn;
-
-    uint8_t opcode = p[i++];
-    bool twoByte = false;
-    if (opcode == 0x0F) {
-        if (i >= avail) return insn;
-        twoByte = true;
-        opcode = p[i++];
-    }
-
-    bool hasModRM = false;
-    int immSize = 0;
-    bool relBranch = false;
-
-    if (!twoByte) {
-        uint8_t lo = opcode & 0x0F;
-
-        if (opcode <= 0x3D && (opcode & 0xC0) == 0x00 && lo <= 0x05 &&
-            (opcode & 0x07) <= 0x05) {
-            if (lo == 0x04) { immSize = 1; }
-            else if (lo == 0x05) { immSize = opSize16 ? 2 : 4; }
-            else if (lo <= 0x03) { hasModRM = true; }
-            else { return insn; }
-        } else if (opcode >= 0x50 && opcode <= 0x5F) { /* push/pop r64, no operand bytes */ }
-        else if (opcode == 0x68) { immSize = opSize16 ? 2 : 4; }
-        else if (opcode == 0x6A) { immSize = 1; }
-        else if (opcode == 0x69) { hasModRM = true; immSize = opSize16 ? 2 : 4; }
-        else if (opcode == 0x6B) { hasModRM = true; immSize = 1; }
-        else if (opcode >= 0x70 && opcode <= 0x7F) { immSize = 1; relBranch = true; }
-        else if (opcode == 0x80) { hasModRM = true; immSize = 1; }
-        else if (opcode == 0x81) { hasModRM = true; immSize = opSize16 ? 2 : 4; }
-        else if (opcode == 0x83) { hasModRM = true; immSize = 1; }
-        else if (opcode >= 0x84 && opcode <= 0x8F) { hasModRM = true; }
-        else if (opcode >= 0x90 && opcode <= 0x97) { /* xchg/nop, no operand bytes */ }
-        else if (opcode == 0x98 || opcode == 0x99) { /* cbw/cwd family */ }
-        else if (opcode == 0xA8) { immSize = 1; }
-        else if (opcode == 0xA9) { immSize = opSize16 ? 2 : 4; }
-        else if (opcode >= 0xB0 && opcode <= 0xB7) { immSize = 1; }
-        else if (opcode >= 0xB8 && opcode <= 0xBF) { immSize = rexW ? 8 : (opSize16 ? 2 : 4); }
-        else if (opcode == 0xC0 || opcode == 0xC1) { hasModRM = true; immSize = 1; }
-        else if (opcode == 0xC2) { immSize = 2; }
-        else if (opcode == 0xC3) { /* ret */ }
-        else if (opcode == 0xC6) { hasModRM = true; immSize = 1; }
-        else if (opcode == 0xC7) { hasModRM = true; immSize = opSize16 ? 2 : 4; }
-        else if (opcode == 0xC9) { /* leave */ }
-        else if (opcode == 0xCC) { /* int3 */ }
-        else if (opcode == 0xCD) { immSize = 1; }
-        else if (opcode == 0xD0 || opcode == 0xD1 || opcode == 0xD2 || opcode == 0xD3) { hasModRM = true; }
-        else if (opcode == 0xE8) { immSize = 4; relBranch = true; }
-        else if (opcode == 0xE9) { immSize = 4; relBranch = true; }
-        else if (opcode == 0xEB) { immSize = 1; relBranch = true; }
-        else if (opcode == 0xF6) { hasModRM = true; immSize = 1; }
-        else if (opcode == 0xF7) { hasModRM = true; immSize = opSize16 ? 2 : 4; }
-        else if (opcode == 0xFE || opcode == 0xFF) { hasModRM = true; }
-        else {
-            return insn; // unrecognized opcode
-        }
-    } else {
-        if (opcode >= 0x80 && opcode <= 0x8F) { immSize = 4; relBranch = true; }
-        else if (opcode == 0x1E) { immSize = 1; }
-        else if (opcode == 0x1F) { hasModRM = true; } 
-        else if (opcode == 0x05 || opcode == 0x31 || opcode == 0x34 || opcode == 0x35 || opcode == 0xA2) { /* syscall/rdtsc/cpuid etc */ }
-        else if (opcode >= 0x40 && opcode <= 0x4F) { hasModRM = true; } // CMOVcc
-        else if (opcode == 0xAF) { hasModRM = true; } // imul
-        else if (opcode == 0xB6 || opcode == 0xB7 || opcode == 0xBE || opcode == 0xBF) { hasModRM = true; } // movzx/movsx
-        else if (opcode >= 0x10 && opcode <= 0x17) { hasModRM = true; } // movups/movaps family
-        else if (opcode >= 0x28 && opcode <= 0x2F) { hasModRM = true; }
-        else if (opcode >= 0x54 && opcode <= 0x5F) { hasModRM = true; }
-        else if (opcode == 0x6E || opcode == 0x6F || opcode == 0x7E || opcode == 0x7F || opcode == 0xD6) { hasModRM = true; }
-        else {
-            return insn;
-        }
-    }
-
-    if (hasModRM) {
-        if (i >= avail) return insn;
-        uint8_t modrm = p[i++];
-        uint8_t mod = (modrm >> 6) & 0x3;
-        uint8_t rm = modrm & 0x7;
-
-        if (mod != 3 && rm == 4) {
-            if (i >= avail) return insn;
-            uint8_t sib = p[i++];
-            uint8_t base = sib & 0x7;
-            if (mod == 0 && base == 5) {
-                i += 4;
-            }
-        }
-
-        if (mod == 0 && rm == 5) {
-            insn.ripRelative = true;
-            insn.dispOffset = i;
-            i += 4;
-        } else if (mod == 1) {
-            i += 1;
-        } else if (mod == 2) {
-            i += 4;
-        }
-    }
-
-    i += static_cast<size_t>(immSize);
-    if (i > avail) return insn;
-
-    insn.length = i;
-    insn.relativeControlFlow = relBranch;
-    insn.valid = true;
-    return insn;
-}
-
-constexpr size_t kX64StubLen = 14;   // FF25 00000000 + imm64
-constexpr size_t kX64MaxStolen = 32;
-constexpr size_t kX64MaxRipFixups = 8;
-
-bool BuildStolenBytesX64(const uint8_t* target, size_t minLen,
-                          uint8_t* outBytes, size_t& outLen,
-                          size_t* outRipOffsets, size_t& outRipCount) {
-    size_t len = 0;
-    outRipCount = 0;
-    while (len < minLen) {
-        if (len >= kX64MaxStolen) return false;
-        X64Insn insn = DecodeX64(target + len, kX64MaxStolen - len);
-        if (!insn.valid) return false;
-        if (insn.relativeControlFlow) return false;
-        if (insn.ripRelative) {
-            if (outRipCount >= kX64MaxRipFixups) return false;
-            outRipOffsets[outRipCount++] = len + insn.dispOffset;
-        }
-        len += insn.length;
-    }
-    std::memcpy(outBytes, target, len);
-    outLen = len;
-    return true;
-}
-
-#endif // RADHOOK_ARCH_X64
-
 // aarch64 prologue check
 #if defined(RADHOOK_ARCH_ARM64)
 
@@ -499,14 +134,19 @@ RadHookResult InstallHook(RadHookOpaque* h, void* target, void* detour) {
     size_t ripOffsets[kX64MaxRipFixups];
     size_t ripCount = 0;
 
-    if (!BuildStolenBytesX64(reinterpret_cast<const uint8_t*>(target), kX64StubLen,
-                            stolen, stolenLen, ripOffsets, ripCount)) {
-        return RadHookResult::DisassemblyFailed;
+    StolenBytesError sberr = BuildStolenBytesX64(
+        reinterpret_cast<const uint8_t*>(target), kX64StubLen,
+        stolen, stolenLen, ripOffsets, ripCount);
+
+    if (sberr != StolenBytesError::None) {
+        return (sberr == StolenBytesError::InsufficientLength)
+            ? RadHookResult::TargetTooSmall
+            : RadHookResult::DisassemblyFailed;
     }
 
     size_t allocSize = stolenLen + kX64StubLen;
-    void* trampolineAlloc = AllocExecNear(target, allocSize);
-    if (!trampolineAlloc) trampolineAlloc = AllocExec(allocSize); // best-effort fallback
+    void* trampolineAlloc = RadAllocExecNear(target, allocSize);
+    if (!trampolineAlloc) trampolineAlloc = RadAllocExec(allocSize); // best-effort fallback
     if (!trampolineAlloc) return RadHookResult::MemoryAllocFailed;
 
     std::memcpy(trampolineAlloc, stolen, stolenLen);
@@ -518,7 +158,7 @@ RadHookResult InstallHook(RadHookOpaque* h, void* target, void* detour) {
         uintptr_t absTarget = reinterpret_cast<uintptr_t>(target) + off + 4 + static_cast<intptr_t>(originalDisp);
         intptr_t newDisp = static_cast<intptr_t>(absTarget) - (reinterpret_cast<intptr_t>(trampolineAlloc) + off + 4);
         if (newDisp < INT32_MIN || newDisp > INT32_MAX) {
-            FreeExec(trampolineAlloc, allocSize);
+            RadFreeExec(trampolineAlloc, allocSize);
             return RadHookResult::TrampolineTooFar;
         }
         int32_t newDisp32 = static_cast<int32_t>(newDisp);
@@ -535,11 +175,11 @@ RadHookResult InstallHook(RadHookOpaque* h, void* target, void* detour) {
     }
     std::memcpy(jumpBack + 6, &backAddr, 8);
 
-    FlushICache(trampolineAlloc, allocSize);
+    RadFlushICache(trampolineAlloc, allocSize);
 
     unsigned long oldProtect = 0;
-    if (!MakeWritableExecutable(target, stolenLen, &oldProtect)) {
-        FreeExec(trampolineAlloc, allocSize);
+    if (!RadMakeWritableExecutable(target, stolenLen, &oldProtect)) {
+        RadFreeExec(trampolineAlloc, allocSize);
         return RadHookResult::MemoryProtectFailed;
     }
 
@@ -560,8 +200,8 @@ RadHookResult InstallHook(RadHookOpaque* h, void* target, void* detour) {
     h->stubLength = kX64StubLen;
 
     std::memcpy(target, hookStub, kX64StubLen);
-    RestoreProtection(target, stolenLen, oldProtect);
-    FlushICache(target, stolenLen);
+    RadRestoreMemoryProtection(target, stolenLen, oldProtect);
+    RadFlushICache(target, stolenLen);
 
     h->target = target;
     h->detour = detour;
@@ -580,18 +220,18 @@ RadHookResult InstallHook(RadHookOpaque* h, void* target, void* detour) {
     }
 
     size_t allocSize = kArm64StubLen + kArm64StubLen;
-    void* trampolineAlloc = AllocExec(allocSize);
+    void* trampolineAlloc = RadAllocExec(allocSize);
     if (!trampolineAlloc) return RadHookResult::MemoryAllocFailed;
 
     std::memcpy(trampolineAlloc, target, kArm64StubLen);
     uintptr_t backAddr = reinterpret_cast<uintptr_t>(target) + kArm64StubLen;
     WriteArm64Stub(reinterpret_cast<uint8_t*>(trampolineAlloc) + kArm64StubLen, backAddr);
 
-    FlushICache(trampolineAlloc, allocSize);
+    RadFlushICache(trampolineAlloc, allocSize);
 
     unsigned long oldProtect = 0;
-    if (!MakeWritableExecutable(target, kArm64StubLen, &oldProtect)) {
-        FreeExec(trampolineAlloc, allocSize);
+    if (!RadMakeWritableExecutable(target, kArm64StubLen, &oldProtect)) {
+        RadFreeExec(trampolineAlloc, allocSize);
         return RadHookResult::MemoryProtectFailed;
     }
 
@@ -605,8 +245,8 @@ RadHookResult InstallHook(RadHookOpaque* h, void* target, void* detour) {
     h->stubLength = kArm64StubLen;
 
     std::memcpy(target, hookStub, kArm64StubLen);
-    RestoreProtection(target, kArm64StubLen, oldProtect);
-    FlushICache(target, kArm64StubLen);
+    RadRestoreMemoryProtection(target, kArm64StubLen, oldProtect);
+    RadFlushICache(target, kArm64StubLen);
 
     h->target = target;
     h->detour = detour;
@@ -624,11 +264,11 @@ RadHookResult EnableHookInternal(RadHookOpaque* h) {
         if (h->enabled) return RadHookResult::AlreadyEnabled;
 
         unsigned long oldProtect = 0;
-        if (!MakeWritableExecutable(h->vtableSlot, sizeof(void*), &oldProtect)) {
+        if (!RadMakeWritableExecutable(h->vtableSlot, sizeof(void*), &oldProtect)) {
             return RadHookResult::MemoryProtectFailed;
         }
         *h->vtableSlot = h->detour;
-        RestoreProtection(h->vtableSlot, sizeof(void*), oldProtect);
+        RadRestoreMemoryProtection(h->vtableSlot, sizeof(void*), oldProtect);
 
         h->enabled = true;
         return RadHookResult::Success;
@@ -638,12 +278,12 @@ RadHookResult EnableHookInternal(RadHookOpaque* h) {
     if (h->enabled) return RadHookResult::AlreadyEnabled;
 
     unsigned long oldProtect = 0;
-    if (!MakeWritableExecutable(h->target, h->originalLength, &oldProtect)) {
+    if (!RadMakeWritableExecutable(h->target, h->originalLength, &oldProtect)) {
         return RadHookResult::MemoryProtectFailed;
     }
     std::memcpy(h->target, h->stubBytes, h->stubLength);
-    RestoreProtection(h->target, h->originalLength, oldProtect);
-    FlushICache(h->target, h->originalLength);
+    RadRestoreMemoryProtection(h->target, h->originalLength, oldProtect);
+    RadFlushICache(h->target, h->originalLength);
 
     h->enabled = true;
     return RadHookResult::Success;
@@ -655,11 +295,11 @@ RadHookResult DisableHookInternal(RadHookOpaque* h) {
         if (!h->enabled) return RadHookResult::AlreadyDisabled;
 
         unsigned long oldProtect = 0;
-        if (!MakeWritableExecutable(h->vtableSlot, sizeof(void*), &oldProtect)) {
+        if (!RadMakeWritableExecutable(h->vtableSlot, sizeof(void*), &oldProtect)) {
             return RadHookResult::MemoryProtectFailed;
         }
         *h->vtableSlot = h->vtableOriginalEntry;
-        RestoreProtection(h->vtableSlot, sizeof(void*), oldProtect);
+        RadRestoreMemoryProtection(h->vtableSlot, sizeof(void*), oldProtect);
 
         h->enabled = false;
         return RadHookResult::Success;
@@ -669,12 +309,12 @@ RadHookResult DisableHookInternal(RadHookOpaque* h) {
     if (!h->enabled) return RadHookResult::AlreadyDisabled;
 
     unsigned long oldProtect = 0;
-    if (!MakeWritableExecutable(h->target, h->originalLength, &oldProtect)) {
+    if (!RadMakeWritableExecutable(h->target, h->originalLength, &oldProtect)) {
         return RadHookResult::MemoryProtectFailed;
     }
     std::memcpy(h->target, h->originalBytes, h->originalLength);
-    RestoreProtection(h->target, h->originalLength, oldProtect);
-    FlushICache(h->target, h->originalLength);
+    RadRestoreMemoryProtection(h->target, h->originalLength, oldProtect);
+    RadFlushICache(h->target, h->originalLength);
 
     h->enabled = false;
     return RadHookResult::Success;
@@ -722,7 +362,7 @@ RadHookResult RadHookDestroy(RadHookHandle handle) {
     }
 
     if (handle->trampolineAlloc) {
-        FreeExec(handle->trampolineAlloc, handle->trampolineAllocSize);
+        RadFreeExec(handle->trampolineAlloc, handle->trampolineAllocSize);
         handle->trampolineAlloc = nullptr;
     }
 

src/x64disasm.cpp

@@ -0,0 +1,163 @@
+#include "radhook/private/disassemble.h"
+
+#include <cstring>
+
+// x86-64 disassembler
+#if defined(RADHOOK_ARCH_X64)
+
+bool IsLegacyPrefix(uint8_t b) {
+    switch (b) {
+        case 0x66: case 0x67: case 0xF0: case 0xF2: case 0xF3:
+        case 0x2E: case 0x36: case 0x3E: case 0x26: case 0x64: case 0x65:
+            return true;
+        default:
+            return false;
+    }
+}
+
+X64Insn DecodeX64(const uint8_t* p, size_t avail) {
+    X64Insn insn;
+    size_t i = 0;
+    bool opSize16 = false;
+    bool rexW = false;
+
+    while (i < avail && IsLegacyPrefix(p[i])) {
+        if (p[i] == 0x66) opSize16 = true;
+        ++i;
+    }
+    if (i < avail && (p[i] & 0xF0) == 0x40) {
+        rexW = (p[i] & 0x08) != 0;
+        ++i;
+    }
+    if (i >= avail) return insn;
+
+    uint8_t opcode = p[i++];
+    bool twoByte = false;
+    if (opcode == 0x0F) {
+        if (i >= avail) return insn;
+        twoByte = true;
+        opcode = p[i++];
+    }
+
+    bool hasModRM = false;
+    int immSize = 0;
+    bool relBranch = false;
+
+    if (!twoByte) {
+        uint8_t lo = opcode & 0x0F;
+
+        if (opcode <= 0x3D && (opcode & 0xC0) == 0x00 && lo <= 0x05 &&
+            (opcode & 0x07) <= 0x05) {
+            if (lo == 0x04) { immSize = 1; }
+            else if (lo == 0x05) { immSize = opSize16 ? 2 : 4; }
+            else if (lo <= 0x03) { hasModRM = true; }
+            else { return insn; }
+        } else if (opcode >= 0x50 && opcode <= 0x5F) { /* push/pop r64, no operand bytes */ }
+        else if (opcode == 0x68) { immSize = opSize16 ? 2 : 4; }
+        else if (opcode == 0x6A) { immSize = 1; }
+        else if (opcode == 0x69) { hasModRM = true; immSize = opSize16 ? 2 : 4; }
+        else if (opcode == 0x6B) { hasModRM = true; immSize = 1; }
+        else if (opcode >= 0x70 && opcode <= 0x7F) { immSize = 1; relBranch = true; }
+        else if (opcode == 0x80) { hasModRM = true; immSize = 1; }
+        else if (opcode == 0x81) { hasModRM = true; immSize = opSize16 ? 2 : 4; }
+        else if (opcode == 0x83) { hasModRM = true; immSize = 1; }
+        else if (opcode >= 0x84 && opcode <= 0x8F) { hasModRM = true; }
+        else if (opcode >= 0x90 && opcode <= 0x97) { /* xchg/nop, no operand bytes */ }
+        else if (opcode == 0x98 || opcode == 0x99) { /* cbw/cwd family */ }
+        else if (opcode == 0xA8) { immSize = 1; }
+        else if (opcode == 0xA9) { immSize = opSize16 ? 2 : 4; }
+        else if (opcode >= 0xB0 && opcode <= 0xB7) { immSize = 1; }
+        else if (opcode >= 0xB8 && opcode <= 0xBF) { immSize = rexW ? 8 : (opSize16 ? 2 : 4); }
+        else if (opcode == 0xC0 || opcode == 0xC1) { hasModRM = true; immSize = 1; }
+        else if (opcode == 0xC2) { immSize = 2; insn.isReturn = true; }
+        else if (opcode == 0xC3) { /* ret */ insn.isReturn = true; }
+        else if (opcode == 0xC6) { hasModRM = true; immSize = 1; }
+        else if (opcode == 0xC7) { hasModRM = true; immSize = opSize16 ? 2 : 4; }
+        else if (opcode == 0xC9) { /* leave */ }
+        else if (opcode == 0xCC) { /* int3 */ insn.isPadding = true; }
+        else if (opcode == 0xCD) { immSize = 1; }
+        else if (opcode == 0xD0 || opcode == 0xD1 || opcode == 0xD2 || opcode == 0xD3) { hasModRM = true; }
+        else if (opcode == 0xE8) { immSize = 4; relBranch = true; }
+        else if (opcode == 0xE9) { immSize = 4; relBranch = true; }
+        else if (opcode == 0xEB) { immSize = 1; relBranch = true; }
+        else if (opcode == 0xF6) { hasModRM = true; immSize = 1; }
+        else if (opcode == 0xF7) { hasModRM = true; immSize = opSize16 ? 2 : 4; }
+        else if (opcode == 0xFE || opcode == 0xFF) { hasModRM = true; }
+        else {
+            return insn; // unrecognized opcode
+        }
+    } else {
+        if (opcode >= 0x80 && opcode <= 0x8F) { immSize = 4; relBranch = true; }
+        else if (opcode == 0x1E) { immSize = 1; }
+        else if (opcode == 0x1F) { hasModRM = true; } 
+        else if (opcode == 0x05 || opcode == 0x31 || opcode == 0x34 || opcode == 0x35 || opcode == 0xA2) { /* syscall/rdtsc/cpuid etc */ }
+        else if (opcode >= 0x40 && opcode <= 0x4F) { hasModRM = true; } // CMOVcc
+        else if (opcode == 0xAF) { hasModRM = true; } // imul
+        else if (opcode == 0xB6 || opcode == 0xB7 || opcode == 0xBE || opcode == 0xBF) { hasModRM = true; } // movzx/movsx
+        else if (opcode >= 0x10 && opcode <= 0x17) { hasModRM = true; } // movups/movaps family
+        else if (opcode >= 0x28 && opcode <= 0x2F) { hasModRM = true; }
+        else if (opcode >= 0x54 && opcode <= 0x5F) { hasModRM = true; }
+        else if (opcode == 0x6E || opcode == 0x6F || opcode == 0x7E || opcode == 0x7F || opcode == 0xD6) { hasModRM = true; }
+        else {
+            return insn;
+        }
+    }
+
+    if (hasModRM) {
+        if (i >= avail) return insn;
+        uint8_t modrm = p[i++];
+        uint8_t mod = (modrm >> 6) & 0x3;
+        uint8_t rm = modrm & 0x7;
+
+        if (mod != 3 && rm == 4) {
+            if (i >= avail) return insn;
+            uint8_t sib = p[i++];
+            uint8_t base = sib & 0x7;
+            if (mod == 0 && base == 5) {
+                i += 4;
+            }
+        }
+
+        if (mod == 0 && rm == 5) {
+            insn.ripRelative = true;
+            insn.dispOffset = i;
+            i += 4;
+        } else if (mod == 1) {
+            i += 1;
+        } else if (mod == 2) {
+            i += 4;
+        }
+    }
+
+    i += static_cast<size_t>(immSize);
+    if (i > avail) return insn;
+
+    insn.length = i;
+    insn.relativeControlFlow = relBranch;
+    insn.valid = true;
+    return insn;
+}
+
+StolenBytesError BuildStolenBytesX64(const uint8_t* target, size_t minLen,
+                                      uint8_t* outBytes, size_t& outLen,
+                                      size_t* outRipOffsets, size_t& outRipCount) {
+    size_t len = 0;
+    outRipCount = 0;
+    while (len < minLen) {
+        if (len >= kX64MaxStolen) return StolenBytesError::ExceedsMaxStolen;
+        X64Insn insn = DecodeX64(target + len, kX64MaxStolen - len);
+        if (!insn.valid) return StolenBytesError::BadDecode;
+        if (insn.isReturn || insn.isPadding) return StolenBytesError::InsufficientLength;
+        if (insn.relativeControlFlow) return StolenBytesError::RelativeControlFlow;
+        if (insn.ripRelative) {
+            if (outRipCount >= kX64MaxRipFixups) return StolenBytesError::TooManyRipFixups;
+            outRipOffsets[outRipCount++] = len + insn.dispOffset;
+        }
+        len += insn.length;
+    }
+    std::memcpy(outBytes, target, len);
+    outLen = len;
+    return StolenBytesError::None;
+}
+
+#endif // RADHOOK_ARCH_X64