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-rw-r--r--elf/dl-libc.c74
1 files changed, 74 insertions, 0 deletions
diff --git a/elf/dl-libc.c b/elf/dl-libc.c
index 1810b13074..8fd98f08e7 100644
--- a/elf/dl-libc.c
+++ b/elf/dl-libc.c
@@ -96,6 +96,50 @@ do_dlclose (void *ptr)
_dl_close ((struct link_map *) ptr);
}
+/* This code is to support __libc_dlopen from __libc_dlopen'ed shared
+ libraries. We need to ensure the statically linked __libc_dlopen
+ etc. functions are used instead of the dynamically loaded. */
+struct dl_open_hook
+{
+ void *(*dlopen_mode) (const char *name, int mode);
+ void *(*dlsym) (void *map, const char *name);
+ int (*dlclose) (void *map);
+};
+
+#ifdef SHARED
+extern struct dl_open_hook *_dl_open_hook;
+libc_hidden_proto (_dl_open_hook);
+struct dl_open_hook *_dl_open_hook __attribute__((nocommon));
+libc_hidden_data_def (_dl_open_hook);
+#else
+static void
+do_dlsym_private (void *ptr)
+{
+ lookup_t l;
+ struct r_found_version vers;
+ vers.name = "GLIBC_PRIVATE";
+ vers.hidden = 1;
+ /* vers.hash = _dl_elf_hash (version); */
+ vers.hash = 0x0963cf85;
+ /* FIXME: Shouldn't we use libc.so.6* here? */
+ vers.filename = NULL;
+
+ struct do_dlsym_args *args = (struct do_dlsym_args *) ptr;
+ args->ref = NULL;
+ l = _dl_lookup_versioned_symbol (args->name, args->map,
+ &args->ref, args->map->l_scope,
+ &vers, 0, 0);
+ args->loadbase = l;
+}
+
+static struct dl_open_hook _dl_open_hook =
+ {
+ .dlopen_mode = __libc_dlopen_mode,
+ .dlsym = __libc_dlsym,
+ .dlclose = __libc_dlclose
+ };
+#endif
+
/* ... and these functions call dlerror_run. */
void *
@@ -105,7 +149,29 @@ __libc_dlopen_mode (const char *name, int mode)
args.name = name;
args.mode = mode;
+#ifdef SHARED
+ if (__builtin_expect (_dl_open_hook != NULL, 0))
+ return _dl_open_hook->dlopen_mode (name, mode);
return (dlerror_run (do_dlopen, &args) ? NULL : (void *) args.map);
+#else
+ if (dlerror_run (do_dlopen, &args))
+ return NULL;
+
+ struct do_dlsym_args sargs;
+ sargs.map = args.map;
+ sargs.name = "_dl_open_hook";
+
+ if (! dlerror_run (do_dlsym_private, &sargs))
+ {
+ struct dl_open_hook **hook
+ = (struct dl_open_hook **)
+ (DL_SYMBOL_ADDRESS (sargs.loadbase, sargs.ref));
+ if (hook != NULL)
+ *hook = &_dl_open_hook;
+ }
+
+ return (void *) args.map;
+#endif
}
void *
@@ -115,6 +181,10 @@ __libc_dlsym (void *map, const char *name)
args.map = map;
args.name = name;
+#ifdef SHARED
+ if (__builtin_expect (_dl_open_hook != NULL, 0))
+ return _dl_open_hook->dlsym (map, name);
+#endif
return (dlerror_run (do_dlsym, &args) ? NULL
: (void *) (DL_SYMBOL_ADDRESS (args.loadbase, args.ref)));
}
@@ -122,6 +192,10 @@ __libc_dlsym (void *map, const char *name)
int
__libc_dlclose (void *map)
{
+#ifdef SHARED
+ if (__builtin_expect (_dl_open_hook != NULL, 0))
+ return _dl_open_hook->dlclose (map);
+#endif
return dlerror_run (do_dlclose, map);
}