Add temporary gotcha build workaround for glibc 2.34+ (LLNL#405)

Author: daboehme

ext/gotcha/src/gotcha_dl.c

@@ -5,7 +5,13 @@
 #include "elf_ops.h"
 #include <dlfcn.h>
 
+#if defined(__GLIBC__) && __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 34
+#    define GOTCHA_DL_SYM_WORKAROUND 1
+#endif
+
+#ifndef GOTCHA_DL_SYM_WORKAROUND
 void* _dl_sym(void* handle, const char* name, void* where);
+#endif
 
 gotcha_wrappee_handle_t orig_dlopen_handle;
 gotcha_wrappee_handle_t orig_dlsym_handle;
@@ -17,13 +23,13 @@ static int per_binding(hash_key_t key, hash_data_t data, void *opaque KNOWN_UNUS
 
    debug_printf(3, "Trying to re-bind %s from tool %s after dlopen\n",
                 binding->user_binding->name, binding->associated_binding_table->tool->tool_name);
-   
+
    while (binding->next_binding) {
       binding = binding->next_binding;
       debug_printf(3, "Selecting new innermost version of binding %s from tool %s.\n",
                    binding->user_binding->name, binding->associated_binding_table->tool->tool_name);
    }
-   
+
    result = prepare_symbol(binding);
    if (result == -1) {
       debug_printf(3, "Still could not prepare binding %s after dlopen\n", binding->user_binding->name);
@@ -45,7 +51,7 @@ static void* dlopen_wrapper(const char* filename, int flags) {
 
    debug_printf(2, "Updating GOT entries for new dlopened libraries\n");
    update_all_library_gots(&function_hash_table);
-  
+
    return handle;
 }
 
@@ -55,13 +61,17 @@ static void* dlsym_wrapper(void* handle, const char* symbol_name){
   int result;
   debug_printf(1, "User called dlsym(%p, %s)\n", handle, symbol_name);
 
-  if(handle == RTLD_NEXT){
-    return _dl_sym(RTLD_NEXT, symbol_name ,__builtin_return_address(0));
-  }
-  if(handle == RTLD_DEFAULT) {
-    return _dl_sym(RTLD_DEFAULT, symbol_name,__builtin_return_address(0));
+  if (handle == RTLD_DEFAULT || handle == RTLD_NEXT) {
+#if defined GOTCHA_DL_SYM_WORKAROUND
+  /* Workaround as _dl_sym isn't exported in glibc 2.34+ anymore.
+     This probably breaks dlsym() wrapping for RTLD_NEXT: need to
+     wait for real fix in Gotcha.
+  */
+    return orig_dlsym(handle, symbol_name);
+#else
+    return _dl_sym(handle, symbol_name ,__builtin_return_address(0));
+#endif
   }
-  
   result = lookup_hashtable(&function_hash_table, (hash_key_t) symbol_name, (hash_data_t *) &binding);
   if (result == -1)
      return orig_dlsym(handle, symbol_name);
@@ -72,7 +82,7 @@ static void* dlsym_wrapper(void* handle, const char* symbol_name){
 struct gotcha_binding_t dl_binds[] = {
   {"dlopen", dlopen_wrapper, &orig_dlopen_handle},
   {"dlsym", dlsym_wrapper, &orig_dlsym_handle}
-};     
+};
 void handle_libdl(){
   gotcha_wrap(dl_binds, 2, "gotcha");
 }