aarch64: Remove barriers from TLS descriptor functions

Remove ldar synchronization and most lazy TLSDESC initialization
related code.

	* sysdeps/aarch64/dl-machine.h (elf_machine_runtime_setup): Remove
	DT_TLSDESC_GOT initialization.
	* sysdeps/aarch64/dl-tlsdesc.S (_dl_tlsdesc_return_lazy): Remove.
	(_dl_tlsdesc_resolve_rela): Likewise.
	(_dl_tlsdesc_resolve_hold): Likewise.
	(_dl_tlsdesc_undefweak): Remove ldar.
	(_dl_tlsdesc_dynamic): Likewise.
	* sysdeps/aarch64/dl-tlsdesc.h (_dl_tlsdesc_return_lazy): Remove.
	(_dl_tlsdesc_resolve_rela): Likewise.
	(_dl_tlsdesc_resolve_hold): Likewise.
	* sysdeps/aarch64/tlsdesc.c (_dl_tlsdesc_resolve_rela_fixup): Remove.
	(_dl_tlsdesc_resolve_hold_fixup): Likewise.
	(_dl_tlsdesc_resolve_rela): Likewise.
	(_dl_tlsdesc_resolve_hold): Likewise.

1 files changed, 1 insertions, 126 deletions

diff --git a/sysdeps/aarch64/tlsdesc.c b/sysdeps/aarch64/tlsdesc.c
index 4c8a5a81d1..bd1356fa8e 100644
--- a/sysdeps/aarch64/tlsdesc.c
+++ b/sysdeps/aarch64/tlsdesc.c
@@ -18,137 +18,12 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <link.h>
 #include <ldsodefs.h>
-#include <elf/dynamic-link.h>
 #include <tls.h>
 #include <dl-tlsdesc.h>
 #include <dl-unmap-segments.h>
+#define _dl_tlsdesc_resolve_hold 0
 #include <tlsdeschtab.h>
-#include <atomic.h>
-
-/* The following functions take an entry_check_offset argument.  It's
-   computed by the caller as an offset between its entry point and the
-   call site, such that by adding the built-in return address that is
-   implicitly passed to the function with this offset, we can easily
-   obtain the caller's entry point to compare with the entry point
-   given in the TLS descriptor.  If it's changed, we want to return
-   immediately.  */
-
-/* This function is used to lazily resolve TLS_DESC RELA relocations.
-   The argument location is used to hold a pointer to the relocation.  */
-
-void
-attribute_hidden
-_dl_tlsdesc_resolve_rela_fixup (struct tlsdesc *td, struct link_map *l)
-{
-  const ElfW(Rela) *reloc = atomic_load_relaxed (&td->arg);
-
-  /* After GL(dl_load_lock) is grabbed only one caller can see td->entry in
-     initial state in _dl_tlsdesc_resolve_early_return_p, other concurrent
-     callers will return and retry calling td->entry.  The updated td->entry
-     synchronizes with the single writer so all read accesses here can use
-     relaxed order.  */
-  if (_dl_tlsdesc_resolve_early_return_p
-      (td, (void*)(D_PTR (l, l_info[ADDRIDX (DT_TLSDESC_PLT)]) + l->l_addr)))
-    return;
-
-  /* The code below was borrowed from _dl_fixup(),
-     except for checking for STB_LOCAL.  */
-  const ElfW(Sym) *const symtab
-    = (const void *) D_PTR (l, l_info[DT_SYMTAB]);
-  const char *strtab = (const void *) D_PTR (l, l_info[DT_STRTAB]);
-  const ElfW(Sym) *sym = &symtab[ELFW(R_SYM) (reloc->r_info)];
-  lookup_t result;
-
-   /* Look up the target symbol.  If the normal lookup rules are not
-      used don't look in the global scope.  */
-  if (ELFW(ST_BIND) (sym->st_info) != STB_LOCAL
-      && __builtin_expect (ELFW(ST_VISIBILITY) (sym->st_other), 0) == 0)
-    {
-      const struct r_found_version *version = NULL;
-
-      if (l->l_info[VERSYMIDX (DT_VERSYM)] != NULL)
-	{
-	  const ElfW(Half) *vernum =
-	    (const void *) D_PTR (l, l_info[VERSYMIDX (DT_VERSYM)]);
-	  ElfW(Half) ndx = vernum[ELFW(R_SYM) (reloc->r_info)] & 0x7fff;
-	  version = &l->l_versions[ndx];
-	  if (version->hash == 0)
-	    version = NULL;
-	}
-
-      result = _dl_lookup_symbol_x (strtab + sym->st_name, l, &sym,
-				    l->l_scope, version, ELF_RTYPE_CLASS_PLT,
-				    DL_LOOKUP_ADD_DEPENDENCY, NULL);
-    }
-  else
-    {
-      /* We already found the symbol.  The module (and therefore its load
-	 address) is also known.  */
-      result = l;
-    }
-
-  if (!sym)
-    {
-      atomic_store_relaxed (&td->arg, (void *) reloc->r_addend);
-      /* This release store synchronizes with the ldar acquire load
-	 instruction in _dl_tlsdesc_undefweak.  */
-      atomic_store_release (&td->entry, _dl_tlsdesc_undefweak);
-    }
-  else
-    {
-#  ifndef SHARED
-      CHECK_STATIC_TLS (l, result);
-#  else
-      if (!TRY_STATIC_TLS (l, result))
-	{
-	  void *p = _dl_make_tlsdesc_dynamic (result, sym->st_value
-					      + reloc->r_addend);
-	  atomic_store_relaxed (&td->arg, p);
-	  /* This release store synchronizes with the ldar acquire load
-	     instruction in _dl_tlsdesc_dynamic.  */
-	  atomic_store_release (&td->entry, _dl_tlsdesc_dynamic);
-	}
-      else
-#  endif
-	{
-	  void *p = (void*) (sym->st_value + result->l_tls_offset
-			     + reloc->r_addend);
-	  atomic_store_relaxed (&td->arg, p);
-	  /* This release store synchronizes with the ldar acquire load
-	     instruction in _dl_tlsdesc_return_lazy.  */
-	  atomic_store_release (&td->entry, _dl_tlsdesc_return_lazy);
-	}
-    }
-
-  _dl_tlsdesc_wake_up_held_fixups ();
-}
-
-/* This function is used to avoid busy waiting for other threads to
-   complete the lazy relocation.  Once another thread wins the race to
-   relocate a TLS descriptor, it sets the descriptor up such that this
-   function is called to wait until the resolver releases the
-   lock.  */
-
-void
-attribute_hidden
-_dl_tlsdesc_resolve_hold_fixup (struct tlsdesc *td, void *caller)
-{
-  /* Maybe we're lucky and can return early.  */
-  if (caller != atomic_load_relaxed (&td->entry))
-    return;
-
-  /* Locking here will stop execution until the running resolver runs
-     _dl_tlsdesc_wake_up_held_fixups(), releasing the lock.
-
-     FIXME: We'd be better off waiting on a condition variable, such
-     that we didn't have to hold the lock throughout the relocation
-     processing.  */
-  __rtld_lock_lock_recursive (GL(dl_load_lock));
-  __rtld_lock_unlock_recursive (GL(dl_load_lock));
-}
-
 
 /* Unmap the dynamic object, but also release its TLS descriptor table
    if there is one.  */