add support for init/finit (constructors and destructors)

[musl] / src / ldso / dynlink.c

diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c
index 057a4cd..ca49f43 100644 (file)
--- a/src/ldso/dynlink.c
+++ b/src/ldso/dynlink.c
@@ -49,6 +49,7 @@ struct dso
        ino_t ino;
        int global;
        int relocated;
+       int constructed;
        struct dso **deps;
        char *name;
        char buf[];
@@ -471,6 +472,20 @@ static size_t find_dyn(Phdr *ph, size_t cnt, size_t stride)
        return 0;
 }
 
+static void do_init_fini(struct dso *p)
+{
+       size_t dyn[DYN_CNT] = {0};
+       for (; p; p=p->prev) {
+               if (p->constructed) return;
+               decode_vec(p->dynv, dyn, DYN_CNT);
+               if (dyn[0] & (1<<DT_FINI))
+                       atexit((void (*)(void))(p->base + dyn[DT_FINI]));
+               if (dyn[0] & (1<<DT_INIT))
+                       ((void (*)(void))(p->base + dyn[DT_INIT]))();
+               p->constructed = 1;
+       }
+}
+
 void *__dynlink(int argc, char **argv)
 {
        size_t *auxv, aux[AUX_CNT] = {0};
@@ -520,6 +535,7 @@ void *__dynlink(int argc, char **argv)
        }
        app->name = argv[0];
        app->global = 1;
+       app->constructed = 1;
        app->dynv = (void *)(app->base + find_dyn(
                (void *)aux[AT_PHDR], aux[AT_PHNUM], aux[AT_PHENT]));
        decode_dyn(app);
@@ -577,6 +593,9 @@ void *__dynlink(int argc, char **argv)
         * error. If the dynamic loader (dlopen) will not be used, free
         * all memory used by the dynamic linker. */
        runtime = 1;
+
+       do_init_fini(tail);
+
        if (!rtld_used) {
                free_all(head);
                free(sys_path);