dl-support.c: add tls support

Signed-off-by: Austin Foxley <austinf@cetoncorp.com>

libc/misc/elf/dl-support.c

@@ -13,6 +13,18 @@
 
 #include <link.h>
 #include <elf.h>
+#if USE_TLS
+#include <assert.h>
+#include <tls.h>
+#include <ldsodefs.h>
+#include <string.h>
+#endif
+
+#if USE_TLS
+
+void (*_dl_init_static_tls) (struct link_map *) = &_dl_nothread_init_static_tls;
+
+#endif
 
 ElfW(Phdr) *_dl_phdr;
 size_t _dl_phnum;
@@ -26,3 +38,33 @@ void internal_function _dl_aux_init (ElfW(auxv_t) *av)
    /* Get the number of program headers from the aux vect */
    _dl_phnum = (size_t) av[AT_PHNUM].a_un.a_val;
 }
+
+#if USE_TLS
+/* Initialize static TLS area and DTV for current (only) thread.
+   libpthread implementations should provide their own hook
+   to handle all threads.  */
+void
+internal_function
+_dl_nothread_init_static_tls (struct link_map *map)
+{
+# if defined(TLS_TCB_AT_TP)
+  void *dest = (char *) THREAD_SELF - map->l_tls_offset;
+# elif defined(TLS_DTV_AT_TP)
+  void *dest = (char *) THREAD_SELF + map->l_tls_offset + TLS_PRE_TCB_SIZE;
+# else
+#  error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
+# endif
+
+  /* Fill in the DTV slot so that a later LD/GD access will find it.  */
+  dtv_t *dtv = THREAD_DTV ();
+  assert (map->l_tls_modid <= dtv[-1].counter);
+  dtv[map->l_tls_modid].pointer.val = dest;
+  dtv[map->l_tls_modid].pointer.is_static = true;
+
+  /* Initialize the memory.  */
+  memset (mempcpy (dest, map->l_tls_initimage, map->l_tls_initimage_size),
+	  '\0', map->l_tls_blocksize - map->l_tls_initimage_size);
+}
+
+#endif
+