UCM: Don't call ucs_status_string() from UCM modules

buildlib/az-helpers.sh

@@ -174,6 +174,23 @@ check_nv_peer_mem() {
     fi
 }
 
+# UCM modules (libucm_cuda, libucm_rocm, ...) must not call into libucs: they
+# are loaded with dlopen and do not link libucs, so when UCX itself is loaded
+# with RTLD_LOCAL the symbol is not found, and lazy binding hides this until
+# the call runs. Run from the build directory.
+check_ucm_no_ucs_symbols() {
+    ucm_modules=$(find src/ucm -path '*/.libs/libucm_*.so*' -type f)
+    if [ -z "${ucm_modules}" ]; then
+        azure_log_error "No UCM modules found in $(pwd)/src/ucm"
+        exit 1
+    fi
+
+    if nm -D --undefined-only ${ucm_modules} | grep -E '\bU ucs_'; then
+        azure_log_error "UCM modules have undefined libucs symbols"
+        exit 1
+    fi
+}
+
 #
 # try load cuda modules if nvidia driver is installed
 #

buildlib/pr/cuda/test_malloc_hook.sh

@@ -89,5 +89,6 @@ test_malloc_hook() {
 check_gpu 'gpu'
 prepare
 build
+check_ucm_no_ucs_symbols
 check_cuda_driver
 test_malloc_hook

buildlib/pr/rocm/test_malloc_hook.sh

@@ -68,5 +68,6 @@ test_malloc_hook() {
 
 prepare
 build
+check_ucm_no_ucs_symbols
 check_rocm_driver
 test_malloc_hook

src/AGENTS.md

@@ -15,7 +15,9 @@ layer boundaries below.
   specific transport backend unless the existing code already does so.
 - `ucm`: memory allocation/event interception and memory hook logic. Be careful
   with initialization order, async-signal-safety assumptions, and interactions
-  with external allocators.
+  with external allocators. UCM modules (`libucm_cuda`, `libucm_rocm`, ...)
+  must not link or call into `libucs`; use UCS headers only for macros and
+  inline functions.
 - `tools`: user-facing utilities. Keep command-line behavior and output stable
   unless the task explicitly changes it.
 

src/ucm/cuda/cudamem.c

@@ -442,7 +442,7 @@ static ucs_status_t ucm_cudamem_install(int events)
 
 out_unlock:
     if (status != UCS_OK) {
-        ucm_diag("failed to install cuda hooks: %s", ucs_status_string(status));
+        ucm_diag("failed to install cuda hooks: status %d", status);
     }
     pthread_mutex_unlock(&install_mutex);
 out:

src/ucm/rocm/rocmmem.c

@@ -243,15 +243,14 @@ static ucs_status_t ucm_rocmmem_install(int events)
     if (installed_hooks & UCM_GPU_HOOK_MODES_MASK) {
         status = UCS_OK;
         if ((bistro_status != UCS_OK) || (reloc_status != UCS_OK)) {
-            ucm_warn("rocm hooks installed with one mechanism only (bistro: %s, "
-                     "reloc: %s)", ucs_status_string(bistro_status),
-                     ucs_status_string(reloc_status));
+            ucm_warn("rocm hooks installed with one mechanism only (bistro: %d, "
+                     "reloc: %d)", bistro_status, reloc_status);
         } else {
             ucm_info("rocm hooks are ready");
         }
     } else {
         status = (bistro_status != UCS_OK) ? bistro_status : reloc_status;
-        ucm_diag("failed to install rocm hooks: %s", ucs_status_string(status));
+        ucm_diag("failed to install rocm hooks: status %d", status);
     }
 
     pthread_mutex_unlock(&install_mutex);