diff options
Diffstat (limited to 'elf/dl-lookup.c')
| -rw-r--r-- | elf/dl-lookup.c | 33 |
1 files changed, 23 insertions, 10 deletions
diff --git a/elf/dl-lookup.c b/elf/dl-lookup.c index 019278c..a6a9584 100644 --- a/elf/dl-lookup.c +++ b/elf/dl-lookup.c @@ -1,5 +1,5 @@ /* Look up a symbol in the loaded objects. - Copyright (C) 1995-2005, 2006 Free Software Foundation, Inc. + Copyright (C) 1995-2005, 2006, 2007 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -25,6 +25,7 @@ #include <ldsodefs.h> #include <dl-hash.h> #include <dl-machine.h> +#include <sysdep-cancel.h> #include <bits/libc-lock.h> #include <tls.h> @@ -85,7 +86,7 @@ dl_new_hash (const char *s) /* Add extra dependency on MAP to UNDEF_MAP. */ static int internal_function -add_dependency (struct link_map *undef_map, struct link_map *map) +add_dependency (struct link_map *undef_map, struct link_map *map, int flags) { struct link_map **list; struct link_map *runp; @@ -98,8 +99,18 @@ add_dependency (struct link_map *undef_map, struct link_map *map) if (undef_map == map) return 0; - /* Make sure nobody can unload the object while we are at it. */ - __rtld_lock_lock_recursive (GL(dl_load_lock)); + /* Make sure nobody can unload the object while we are at it. + If we hold a scope lock drop it now to avoid ABBA locking problems. */ + if ((flags & DL_LOOKUP_SCOPE_LOCK) != 0 && !RTLD_SINGLE_THREAD_P) + { + __rtld_mrlock_unlock (undef_map->l_scope_lock); + + __rtld_lock_lock_recursive (GL(dl_load_lock)); + + __rtld_mrlock_lock (undef_map->l_scope_lock); + } + else + __rtld_lock_lock_recursive (GL(dl_load_lock)); /* Avoid references to objects which cannot be unloaded anyway. */ if (map->l_type != lt_loaded @@ -226,9 +237,10 @@ _dl_lookup_symbol_x (const char *undef_name, struct link_map *undef_map, bump_num_relocations (); - /* No other flag than DL_LOOKUP_ADD_DEPENDENCY is allowed if we look - up a versioned symbol. */ - assert (version == NULL || flags == 0 || flags == DL_LOOKUP_ADD_DEPENDENCY); + /* No other flag than DL_LOOKUP_ADD_DEPENDENCY and DL_LOOKUP_SCOPE_LOCK + is allowed if we look up a versioned symbol. */ + assert (version == NULL || (flags & ~(DL_LOOKUP_ADD_DEPENDENCY + | DL_LOOKUP_SCOPE_LOCK)) == 0); size_t i = 0; if (__builtin_expect (skip_map != NULL, 0)) @@ -338,12 +350,13 @@ _dl_lookup_symbol_x (const char *undef_name, struct link_map *undef_map, runtime lookups. */ && (flags & DL_LOOKUP_ADD_DEPENDENCY) != 0 /* Add UNDEF_MAP to the dependencies. */ - && add_dependency (undef_map, current_value.m) < 0) + && add_dependency (undef_map, current_value.m, flags) < 0) /* Something went wrong. Perhaps the object we tried to reference was just removed. Try finding another definition. */ return _dl_lookup_symbol_x (undef_name, undef_map, ref, - symbol_scope, version, type_class, - flags, skip_map); + (flags & DL_LOOKUP_SCOPE_LOCK) == 0 + ? symbol_scope : undef_map->l_scope, version, + type_class, flags, skip_map); /* The object is used. */ current_value.m->l_used = 1; |