Move arm from ports to libc.

I've moved the ARM port from ports to the main sysdeps hierarchy.
Beyond the README update, the move of the files was simply

git mv ports/sysdeps/arm sysdeps/arm
git mv ports/sysdeps/unix/arm sysdeps/unix/arm
git mv ports/sysdeps/unix/sysv/linux/arm sysdeps/unix/sysv/linux/arm

and in addition to the ChangeLog entries here, I put a note at the top
of ports/ChangeLog.arm similar to that at the top of
ChangeLog.powerpc.  There is deliberately no NEWS change, as I think
it makes the most sense to put in a general note above all ports
having moved if we can achieve that for 2.20.

Tested that disassembly of installed shared libraries for arm is the
same before and after this patch, except for data (not instructions)
in ld.so (there are assertions in sysdeps/arm/dl-machine.h, and the
path by which that file is found, and so by which it appears in the
assertion message, changes as a result of the move).

	* sysdeps/arm: Move directory from ports/sysdeps/arm.
	* sysdeps/unix/arm: Move directory from ports/sysdeps/unix/arm.
	* sysdeps/unix/sysv/linux/arm: Move directory from
	ports/sysdeps/unix/sysv/linux/arm.
	* README: Update listing for arm-*-linux-gnueabi.

ports/ChangeLog.arm:
	* sysdeps/arm: Move directory to ../sysdeps/arm.
	* sysdeps/unix/arm: Move directory to ../sysdeps.arm.
	* sysdeps/unix/sysv/linux/arm: Move directory to
	../sysdeps/unix/sysv/linux/arm.

1 files changed, 160 insertions, 0 deletions

diff --git a/sysdeps/arm/tlsdesc.c b/sysdeps/arm/tlsdesc.c
new file mode 100644
index 0000000..fc754d6
--- /dev/null
+++ b/sysdeps/arm/tlsdesc.c
@@ -0,0 +1,160 @@
+/* Manage TLS descriptors.  ARM version.
+   Copyright (C) 2005-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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, 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 <tlsdeschtab.h>
+
+/* This function is used to lazily resolve TLS_DESC REL relocations
+   Besides the TLS descriptor itself, we get the module's got address
+   as the second parameter. */
+
+void
+attribute_hidden
+_dl_tlsdesc_lazy_resolver_fixup (struct tlsdesc volatile *td,
+				 Elf32_Addr *got)
+{
+  struct link_map *l = (struct link_map *)got[1];
+  lookup_t result;
+  unsigned long value;
+
+  if (_dl_tlsdesc_resolve_early_return_p
+      (td, (void*)(D_PTR (l, l_info[ADDRIDX (DT_TLSDESC_PLT)]) + l->l_addr)))
+    return;
+
+  if (td->argument.value & 0x80000000)
+    {
+      /* A global symbol, this is the symbol index.  */
+      /* The code below was borrowed from _dl_fixup().  */
+      const Elf_Symndx symndx = td->argument.value ^ 0x80000000;
+      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[symndx];
+
+      /* 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[symndx] & 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);
+	  if (sym)
+	    value = sym->st_value;
+	  else
+	    {
+	      td->entry = _dl_tlsdesc_undefweak;
+	      goto done;
+	    }
+	}
+      else
+	{
+	  /* We already found the symbol.  The module (and therefore its load
+	     address) is also known.  */
+	  result = l;
+	  value = sym->st_value;
+	}
+    }
+  else
+    {
+      /* A local symbol, this is the offset within our tls section.
+	 */
+      value = td->argument.value;
+      result = l;
+    }
+
+#ifndef SHARED
+  CHECK_STATIC_TLS (l, result);
+#else
+  if (!TRY_STATIC_TLS (l, result))
+    {
+      td->argument.pointer = _dl_make_tlsdesc_dynamic (result, value);
+      td->entry = _dl_tlsdesc_dynamic;
+    }
+  else
+#endif
+    {
+      td->argument.value = value + result->l_tls_offset;
+      td->entry = _dl_tlsdesc_return;
+    }
+
+ done:
+  _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 volatile *td,
+				void *caller)
+{
+  /* Maybe we're lucky and can return early.  */
+  if (caller != 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.  */
+
+void
+internal_function
+_dl_unmap (struct link_map *map)
+{
+  __munmap ((void *) (map)->l_map_start,
+	    (map)->l_map_end - (map)->l_map_start);
+
+#if SHARED
+  /* _dl_unmap is only called for dlopen()ed libraries, for which
+     calling free() is safe, or before we've completed the initial
+     relocation, in which case calling free() is probably pointless,
+     but still safe.  */
+  if (map->l_mach.tlsdesc_table)
+    htab_delete (map->l_mach.tlsdesc_table);
+#endif
+}