diff options
Diffstat (limited to 'elf/dl-open.c')
| -rw-r--r-- | elf/dl-open.c | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/elf/dl-open.c b/elf/dl-open.c index 529806cc36..113e472165 100644 --- a/elf/dl-open.c +++ b/elf/dl-open.c @@ -21,6 +21,7 @@ #include <dlfcn.h> #include <stdlib.h> #include <errno.h> +#include <libc-lock.h> extern ElfW(Addr) _dl_sysdep_start (void **start_argptr, @@ -38,6 +39,17 @@ extern char **__environ; size_t _dl_global_scope_alloc; + +/* During the program run we must not modify the global data of + loaded shared object simultanously in two threads. Therefore we + protect `_dl_open' and `_dl_close' in dl-close.c. + + This must be a recursive lock since the initializer function of + the loaded object might as well require a call to this function. + At this time it is not anymore a problem to modify the tables. */ +__libc_lock_define_initialized_recursive (, _dl_load_lock) + + struct link_map * _dl_open (const char *file, int mode) { @@ -45,11 +57,17 @@ _dl_open (const char *file, int mode) ElfW(Addr) init; struct r_debug *r; + /* Make sure we are alone. */ + __libc_lock_lock (_dl_load_lock); + /* Load the named object. */ new = _dl_map_object (NULL, file, lt_loaded, 0); if (new->l_searchlist) - /* It was already open. */ - return new; + { + /* It was already open. */ + __libc_lock_unlock (_dl_load_lock); + return new; + } /* Load that object's dependencies. */ _dl_map_object_deps (new, NULL, 0, 0); @@ -152,5 +170,8 @@ _dl_open (const char *file, int mode) has loaded a dynamic object now has competition. */ __libc_multiple_libcs = 1; + /* Release the lock. */ + __libc_lock_unlock (_dl_load_lock); + return new; } |