fix(vt): alloc overflow guard, registry bounds check, whole-archive on library interface

Co-Authored-By: Claude Fable 5 <[email protected]>

Author: mudler

CMakeLists.txt

@@ -49,6 +49,12 @@ add_library(vllm STATIC
   src/vt/backend.cpp
   src/vt/cpu/cpu_backend.cpp)
 add_library(vllm::vllm ALIAS vllm)
+# Static-init registrars (e.g. the CPU backend) live in archive members no
+# consumer references directly; force-link the whole vllm archive so every
+# consumer (tests, C API shared lib, benchmarks) gets backend registration.
+if(UNIX AND NOT APPLE)
+  target_link_options(vllm INTERFACE "LINKER:--whole-archive,$<TARGET_FILE:vllm>,--no-whole-archive")
+endif()
 target_include_directories(vllm
   PUBLIC include ${CMAKE_CURRENT_BINARY_DIR}/include)
 target_include_directories(vllm SYSTEM PUBLIC third_party)

include/vt/backend.h

@@ -30,6 +30,9 @@ class Backend {
 };
 
 Backend& GetBackend(DeviceType type);
+// Threading contract: all registration must complete before main() runs
+// (backends register via static initializers). After that, GetBackend is
+// lock-free reads only; no synchronization is performed.
 void RegisterBackend(DeviceType type, Backend* backend);
 
 }  // namespace vt

src/vt/backend.cpp

@@ -17,6 +17,7 @@ std::array<Backend*, kNumDeviceTypes>& Registry() {
 }  // namespace
 
 Backend& GetBackend(DeviceType type) {
+  VT_CHECK(static_cast<size_t>(type) < kNumDeviceTypes, "invalid device type");
   Backend* b = Registry()[static_cast<size_t>(type)];
   VT_CHECK(b != nullptr, std::string("no backend registered for device type ") +
                              std::to_string(static_cast<int>(type)));

src/vt/cpu/cpu_backend.cpp

@@ -1,4 +1,5 @@
 // vllm.cpp original (vt runtime, inventory deviation §9.1); no upstream mirror.
+#include <cstdint>
 #include <cstdlib>
 #include <cstring>
 
@@ -10,6 +11,7 @@ namespace {
 class CpuBackend final : public Backend {
  public:
   void* Alloc(size_t bytes) override {
+    VT_CHECK(bytes <= SIZE_MAX - 63, "cpu alloc size overflow");
     void* p = std::aligned_alloc(64, ((bytes + 63) / 64) * 64);  // 64B-aligned, padded size
     VT_CHECK(p != nullptr, "cpu alloc failed");
     return p;

tests/CMakeLists.txt

@@ -4,11 +4,6 @@ target_include_directories(vllm_test_main SYSTEM PUBLIC ${CMAKE_SOURCE_DIR}/thir
 function(vllm_cpp_add_test name)
   add_executable(${name} ${ARGN})
   target_link_libraries(${name} PRIVATE vllm::vllm vllm_test_main)
-  # Static-init registrars (e.g. the CPU backend) live in archive members no
-  # test references directly; force-link the whole vllm archive so they run.
-  if(UNIX AND NOT APPLE)
-    target_link_options(${name} PRIVATE "LINKER:--whole-archive,$<TARGET_FILE:vllm>,--no-whole-archive")
-  endif()
   vllm_cpp_set_warnings(${name})
   add_test(NAME ${name} COMMAND ${name})
 endfunction()