Prepare for radical source tree reorganization. zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 121 insertions, 0 deletions

diff --git a/REORG.TODO/elf/setup-vdso.h b/REORG.TODO/elf/setup-vdso.h
new file mode 100644
index 0000000000..2db597eba3
--- /dev/null
+++ b/REORG.TODO/elf/setup-vdso.h
@@ -0,0 +1,121 @@
+/* Set up the data structures for the system-supplied DSO.
+   Copyright (C) 2012-2017 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/>.  */
+
+static inline void __attribute__ ((always_inline))
+setup_vdso (struct link_map *main_map __attribute__ ((unused)),
+	    struct link_map ***first_preload __attribute__ ((unused)))
+{
+#ifdef NEED_DL_SYSINFO_DSO
+  if (GLRO(dl_sysinfo_dso) == NULL)
+    return;
+
+  /* Do an abridged version of the work _dl_map_object_from_fd would do
+     to map in the object.  It's already mapped and prelinked (and
+     better be, since it's read-only and so we couldn't relocate it).
+     We just want our data structures to describe it as if we had just
+     mapped and relocated it normally.  */
+  struct link_map *l = _dl_new_object ((char *) "", "", lt_library, NULL,
+				       0, LM_ID_BASE);
+  if (__glibc_likely (l != NULL))
+    {
+      static ElfW(Dyn) dyn_temp[DL_RO_DYN_TEMP_CNT] attribute_relro;
+
+      l->l_phdr = ((const void *) GLRO(dl_sysinfo_dso)
+		   + GLRO(dl_sysinfo_dso)->e_phoff);
+      l->l_phnum = GLRO(dl_sysinfo_dso)->e_phnum;
+      for (uint_fast16_t i = 0; i < l->l_phnum; ++i)
+	{
+	  const ElfW(Phdr) *const ph = &l->l_phdr[i];
+	  if (ph->p_type == PT_DYNAMIC)
+	    {
+	      l->l_ld = (void *) ph->p_vaddr;
+	      l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
+	    }
+	  else if (ph->p_type == PT_LOAD)
+	    {
+	      if (! l->l_addr)
+		l->l_addr = ph->p_vaddr;
+	      if (ph->p_vaddr + ph->p_memsz >= l->l_map_end)
+		l->l_map_end = ph->p_vaddr + ph->p_memsz;
+	      if ((ph->p_flags & PF_X)
+		  && ph->p_vaddr + ph->p_memsz >= l->l_text_end)
+		l->l_text_end = ph->p_vaddr + ph->p_memsz;
+	    }
+	  else
+	    /* There must be no TLS segment.  */
+	    assert (ph->p_type != PT_TLS);
+	}
+      l->l_map_start = (ElfW(Addr)) GLRO(dl_sysinfo_dso);
+      l->l_addr = l->l_map_start - l->l_addr;
+      l->l_map_end += l->l_addr;
+      l->l_text_end += l->l_addr;
+      l->l_ld = (void *) ((ElfW(Addr)) l->l_ld + l->l_addr);
+      elf_get_dynamic_info (l, dyn_temp);
+      _dl_setup_hash (l);
+      l->l_relocated = 1;
+
+      /* The vDSO is always used.  */
+      l->l_used = 1;
+
+      /* Initialize l_local_scope to contain just this map.  This allows
+	 the use of dl_lookup_symbol_x to resolve symbols within the vdso.
+	 So we create a single entry list pointing to l_real as its only
+	 element */
+      l->l_local_scope[0]->r_nlist = 1;
+      l->l_local_scope[0]->r_list = &l->l_real;
+
+      /* Now that we have the info handy, use the DSO image's soname
+	 so this object can be looked up by name.  Note that we do not
+	 set l_name here.  That field gives the file name of the DSO,
+	 and this DSO is not associated with any file.  */
+      if (l->l_info[DT_SONAME] != NULL)
+	{
+	  /* Work around a kernel problem.  The kernel cannot handle
+	     addresses in the vsyscall DSO pages in writev() calls.  */
+	  const char *dsoname = ((char *) D_PTR (l, l_info[DT_STRTAB])
+				 + l->l_info[DT_SONAME]->d_un.d_val);
+	  size_t len = strlen (dsoname) + 1;
+	  char *copy = malloc (len);
+	  if (copy == NULL)
+	    _dl_fatal_printf ("out of memory\n");
+	  l->l_libname->name = l->l_name = memcpy (copy, dsoname, len);
+	}
+
+      /* Add the vDSO to the object list.  */
+      _dl_add_to_namespace_list (l, LM_ID_BASE);
+
+# if IS_IN (rtld)
+      /* Rearrange the list so this DSO appears after rtld_map.  */
+      assert (l->l_next == NULL);
+      assert (l->l_prev == main_map);
+      GL(dl_rtld_map).l_next = l;
+      l->l_prev = &GL(dl_rtld_map);
+      *first_preload = &l->l_next;
+# else
+      GL(dl_nns) = 1;
+# endif
+
+      /* We have a prelinked DSO preloaded by the system.  */
+      GLRO(dl_sysinfo_map) = l;
+# ifdef NEED_DL_SYSINFO
+      if (GLRO(dl_sysinfo) == DL_SYSINFO_DEFAULT)
+	GLRO(dl_sysinfo) = GLRO(dl_sysinfo_dso)->e_entry + l->l_addr;
+# endif
+    }
+#endif
+}