Introduce TLS descriptors for i386 and x86_64.

	* include/inline-hashtab.h: New file, copied from 2005's
	libiberty, with fix for memory leak imported afterwards by
	Glauber de Oliveira Costa.
	* elf/tlsdeschtab.h: New file.
	* elf/dl-reloc.c (_dl_try_allocate_static_tls): Extract from...
	(_dl_allocate_static_tls): ... here.  Rearrange failure path.
	(CHECK_STATIC_TLS): Move to...
	* elf/dynamic-link.h: ... this file.
	(TRY_STATIC_TLS): New macro.
	* elf/dl-conflict.c (CHECK_STATIC_TLS, TRY_STATIC_TLS): Override.
	* elf/elf.h (R_386_TLS_GOTDESC, R_386_TLS_DESC_CALL,
	R_386_TLS_DESC): Define.
	(R_X86_64_PC64, R_X86_GOTOFF64, R_X86_64_GOTPC32): Merge from
	binutils.
	(R_X86_64_GOTPC32_TLSDESC, R_X86_64_TLSDESC_CALL,
	R_X86_64_TLSDESC): Define.
	(R_386_NUM, R_X86_64_NUM): Adjust.
	* sysdeps/i386/Makefile (sysdep-dl-routines, sysdep_routines,
	systep-rtld-routines): Add tlsdesc and dl-tlsdesc for elf subdir.
	(gen-as-const-headers): Add tlsdesc.sym to csu subdir.
	* sysdeps/i386/dl-lookupcfg.h: New file.  Introduce _dl_unmap to
	release tlsdesc_table.
	* sysdeps/i386/dl-machine.h: Include dl-tlsdesc.h.
	(elf_machine_type_class): Mark R_386_TLS_DESC as PLT class.
	(elf_machine_rel): Handle R_386_TLS_DESC.
	(elf_machine_rela): Likewise.
	(elf_machine_lazy_rel): Likewise.
	(elf_machine_lazy_rela): Likewise.
	* sysdeps/i386/dl-tls.h (struct dl_tls_index): Name it.
	* sysdeps/i386/dl-tlsdesc.S: New file.
	* sysdeps/i386/dl-tlsdesc.h: New file.
	* sysdeps/i386/tlsdesc.c: New file.
	* sysdeps/i386/tlsdesc.sym: New file.
	* sysdeps/i386/bits/linkmap.h (struct link_map_machine): Add
	tlsdesc_table.
	* sysdeps/x86_64/Makefile (sysdep-dl-routines, sysdep_routines,
	systep-rtld-routines): Add tlsdesc and dl-tlsdesc for elf subdir.
	(gen-as-const-headers): Add tlsdesc.sym to csu subdir.
	* sysdeps/x86_64/dl-lookupcfg.h: New file.  Introduce _dl_unmap to
	release tlsdesc_table.
	* sysdeps/x86_64/dl-machine.h: Include dl-tlsdesc.h.
	(elf_machine_runtime_setup): Set up lazy TLSDESC GOT entry.
	(elf_machine_type_class): Mark R_X86_64_TLSDESC as PLT class.
	(elf_machine_rel): Handle R_X86_64_TLSDESC.
	(elf_machine_rela): Likewise.
	(elf_machine_lazy_rel): Likewise.
	* sysdeps/x86_64/dl-tls.h (struct dl_tls_index): Name it.
	(__tls_get_addr): Do not declare for non-shared compiles.
	* sysdeps/x86_64/dl-tlsdesc.S: New file.
	* sysdeps/x86_64/dl-tlsdesc.h: New file.
	* sysdeps/x86_64/tlsdesc.c: New file.
	* sysdeps/x86_64/tlsdesc.sym: New file.
	* sysdeps/x86_64/bits/linkmap.h (struct link_map_machine): Add
	tlsdesc_table for both 32- and 64-bit structs.

1 files changed, 157 insertions, 0 deletions

diff --git a/elf/tlsdeschtab.h b/elf/tlsdeschtab.h
new file mode 100644
index 0000000..c3cbc3f
--- /dev/null
+++ b/elf/tlsdeschtab.h
@@ -0,0 +1,157 @@
+/* Hash table for TLS descriptors.
+   Copyright (C) 2005, 2008 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Alexandre Oliva  <aoliva@redhat.com>
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#ifndef TLSDESCHTAB_H
+# define TLSDESCHTAB_H 1
+
+# ifdef SHARED
+
+#  include <inline-hashtab.h>
+
+inline static int
+hash_tlsdesc (void *p)
+{
+  struct tlsdesc_dynamic_arg *td = p;
+
+  /* We know all entries are for the same module, so ti_offset is the
+     only distinguishing entry.  */
+  return td->tlsinfo.ti_offset;
+}
+
+inline static int
+eq_tlsdesc (void *p, void *q)
+{
+  struct tlsdesc_dynamic_arg *tdp = p, *tdq = q;
+
+  return tdp->tlsinfo.ti_offset == tdq->tlsinfo.ti_offset;
+}
+
+inline static int
+map_generation (struct link_map *map)
+{
+  size_t idx = map->l_tls_modid;
+  struct dtv_slotinfo_list *listp = GL(dl_tls_dtv_slotinfo_list);
+
+  /* Find the place in the dtv slotinfo list.  */
+  do
+    {
+      /* Does it fit in the array of this list element?  */
+      if (idx < listp->len)
+	{
+	  /* We should never get here for a module in static TLS, so
+	     we can assume that, if the generation count is zero, we
+	     still haven't determined the generation count for this
+	     module.  */
+	  if (listp->slotinfo[idx].gen)
+	    return listp->slotinfo[idx].gen;
+	  else
+	    break;
+	}
+      idx -= listp->len;
+      listp = listp->next;
+    }
+  while (listp != NULL);
+
+  /* If we get to this point, the module still hasn't been assigned an
+     entry in the dtv slotinfo data structures, and it will when we're
+     done with relocations.  At that point, the module will get a
+     generation number that is one past the current generation, so
+     return exactly that.  */
+  return GL(dl_tls_generation) + 1;
+}
+
+void *
+internal_function
+_dl_make_tlsdesc_dynamic (struct link_map *map, size_t ti_offset)
+{
+  struct hashtab *ht;
+  void **entry;
+  struct tlsdesc_dynamic_arg *td, test;
+
+  /* FIXME: We could use a per-map lock here, but is it worth it?  */
+  __rtld_lock_lock_recursive (GL(dl_load_lock));
+
+  ht = map->l_mach.tlsdesc_table;
+  if (! ht)
+    {
+      ht = htab_create ();
+      if (! ht)
+	{
+	  __rtld_lock_unlock_recursive (GL(dl_load_lock));
+	  return 0;
+	}
+      map->l_mach.tlsdesc_table = ht;
+    }
+
+  test.tlsinfo.ti_module = map->l_tls_modid;
+  test.tlsinfo.ti_offset = ti_offset;
+  entry = htab_find_slot (ht, &test, 1, hash_tlsdesc, eq_tlsdesc);
+  if (*entry)
+    {
+      td = *entry;
+      __rtld_lock_unlock_recursive (GL(dl_load_lock));
+      return td;
+    }
+
+  *entry = td = malloc (sizeof (struct tlsdesc_dynamic_arg));
+  /* This may be higher than the map's generation, but it doesn't
+     matter much.  Worst case, we'll have one extra DTV update per
+     thread.  */
+  td->gen_count = map_generation (map);
+  td->tlsinfo = test.tlsinfo;
+
+  __rtld_lock_unlock_recursive (GL(dl_load_lock));
+  return td;
+}
+
+# endif /* SHARED */
+
+/* The idea of the following two functions is to stop multiple threads
+   from attempting to resolve the same TLS descriptor without busy
+   waiting.  Ideally, we should be able to release the lock right
+   after changing td->entry, and then using say a condition variable
+   or a futex wake to wake up any waiting threads, but let's try to
+   avoid introducing such dependencies.  */
+
+inline static int
+_dl_tlsdesc_resolve_early_return_p (struct tlsdesc volatile *td, void *caller)
+{
+  if (caller != td->entry)
+    return 1;
+
+  __rtld_lock_lock_recursive (GL(dl_load_lock));
+  if (caller != td->entry)
+    {
+      __rtld_lock_unlock_recursive (GL(dl_load_lock));
+      return 1;
+    }
+
+  td->entry = _dl_tlsdesc_resolve_hold;
+
+  return 0;
+}
+
+inline static void
+_dl_tlsdesc_wake_up_held_fixups (void)
+{
+  __rtld_lock_unlock_recursive (GL(dl_load_lock));
+}
+
+#endif