From 10b39a5124aea509dfeef2f39a0835adb0fb2296 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Fri, 9 Oct 2020 10:13:14 +0200 Subject: [PATCH] elf: Add library search path information to ld.so --help Reviewed-by: Adhemerval Zanella --- elf/dl-usage.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) diff --git a/elf/dl-usage.c b/elf/dl-usage.c index 1003a435bf..8d39bc9d54 100644 --- a/elf/dl-usage.c +++ b/elf/dl-usage.c @@ -46,6 +46,61 @@ PARTICULAR PURPOSE.\n\ _exit (EXIT_SUCCESS); } +/* Print part of the library search path (from a single source). */ +static void +print_search_path_for_help_1 (struct r_search_path_elem **list) +{ + if (list == NULL || list == (void *) -1) + /* Path is missing or marked as inactive. */ + return; + + for (; *list != NULL; ++list) + { + _dl_write (STDOUT_FILENO, " ", 2); + const char *name = (*list)->dirname; + size_t namelen = (*list)->dirnamelen; + if (namelen == 0) + { + /* The empty string denotes the current directory. */ + name = "."; + namelen = 1; + } + else if (namelen > 1) + /* Remove the trailing slash. */ + --namelen; + _dl_write (STDOUT_FILENO, name, namelen); + _dl_printf (" (%s)\n", (*list)->what); + } +} + +/* Prints the library search path. See _dl_init_paths in dl-load.c + how this information is populated. */ +static void +print_search_path_for_help (struct dl_main_state *state) +{ + if (__rtld_search_dirs.dirs == NULL) + /* The run-time search paths have not yet been initialized. */ + _dl_init_paths (state->library_path, state->library_path_source); + + _dl_printf ("\nShared library search path:\n"); + + /* The print order should reflect the processing in + _dl_map_object. */ + + struct link_map *map = GL(dl_ns)[LM_ID_BASE]._ns_loaded; + if (map != NULL) + print_search_path_for_help_1 (map->l_rpath_dirs.dirs); + + print_search_path_for_help_1 (__rtld_env_path_list.dirs); + + if (map != NULL) + print_search_path_for_help_1 (map->l_runpath_dirs.dirs); + + _dl_printf (" (libraries located via %s)\n", LD_SO_CACHE); + + print_search_path_for_help_1 (__rtld_search_dirs.dirs); +} + void _dl_help (const char *argv0, struct dl_main_state *state) { @@ -80,5 +135,6 @@ setting environment variables (which would be inherited by subprocesses).\n\ This program interpreter self-identifies as: " RTLD "\n\ ", argv0); + print_search_path_for_help (state); _exit (EXIT_SUCCESS); }