Squashed 'third_party/elfutils/' content from commit 555e15e

Change-Id: I61cde98949e47e5c8c09c33260de17f30921be79
git-subtree-dir: third_party/elfutils
git-subtree-split: 555e15ebe8bf1eb33d00747173cfc80cc65648a4
diff --git a/libelf/elf_end.c b/libelf/elf_end.c
new file mode 100644
index 0000000..160f0b8
--- /dev/null
+++ b/libelf/elf_end.c
@@ -0,0 +1,239 @@
+/* Free resources associated with Elf descriptor.
+   Copyright (C) 1998,1999,2000,2001,2002,2004,2005,2007,2015,2016 Red Hat, Inc.
+   This file is part of elfutils.
+   Written by Ulrich Drepper <drepper@redhat.com>, 1998.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils 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
+   General Public License for more details.
+
+   You should have received copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+
+#include "libelfP.h"
+
+
+int
+elf_end (Elf *elf)
+{
+  Elf *parent;
+
+  if (elf == NULL)
+    /* This is allowed and is a no-op.  */
+    return 0;
+
+  /* Make sure we are alone.  */
+  rwlock_wrlock (elf->lock);
+
+  if (elf->ref_count != 0 && --elf->ref_count != 0)
+    {
+      /* Not yet the last activation.  */
+      int result = elf->ref_count;
+      rwlock_unlock (elf->lock);
+      return result;
+    }
+
+  if (elf->kind == ELF_K_AR)
+    {
+      /* We cannot remove the descriptor now since we still have some
+	 descriptors which depend on it.  But we can free the archive
+	 symbol table since this is only available via the archive ELF
+	 descriptor.  The long name table cannot be freed yet since
+	 the archive headers for the ELF files in the archive point
+	 into this array.  */
+      if (elf->state.ar.ar_sym != (Elf_Arsym *) -1l)
+	free (elf->state.ar.ar_sym);
+      elf->state.ar.ar_sym = NULL;
+
+      if (elf->state.ar.children != NULL)
+	return 0;
+    }
+
+  /* Remove this structure from the children list.  */
+  parent = elf->parent;
+  if (parent != NULL)
+    {
+      /* This is tricky.  Lock must be acquire from the father to
+	 the child but here we already have the child lock.  We
+	 solve this problem by giving free the child lock.  The
+	 state of REF_COUNT==0 is handled all over the library, so
+	 this should be ok.  */
+      rwlock_unlock (elf->lock);
+      rwlock_rdlock (parent->lock);
+      rwlock_wrlock (elf->lock);
+
+      if (parent->state.ar.children == elf)
+	parent->state.ar.children = elf->next;
+      else
+	{
+	  struct Elf *child = parent->state.ar.children;
+
+	  while (child->next != elf)
+	    child = child->next;
+
+	  child->next = elf->next;
+	}
+
+      rwlock_unlock (parent->lock);
+    }
+
+  /* This was the last activation.  Free all resources.  */
+  switch (elf->kind)
+    {
+    case ELF_K_AR:
+      if (elf->state.ar.long_names != NULL)
+	free (elf->state.ar.long_names);
+      break;
+
+    case ELF_K_ELF:
+      {
+	Elf_Data_Chunk *rawchunks
+	  = (elf->class == ELFCLASS32
+	     || (offsetof (struct Elf, state.elf32.rawchunks)
+		 == offsetof (struct Elf, state.elf64.rawchunks))
+	     ? elf->state.elf32.rawchunks
+	     : elf->state.elf64.rawchunks);
+	while (rawchunks != NULL)
+	  {
+	    Elf_Data_Chunk *next = rawchunks->next;
+	    if (rawchunks->dummy_scn.flags & ELF_F_MALLOCED)
+	      free (rawchunks->data.d.d_buf);
+	    free (rawchunks);
+	    rawchunks = next;
+	  }
+
+	Elf_ScnList *list = (elf->class == ELFCLASS32
+			     || (offsetof (struct Elf, state.elf32.scns)
+				 == offsetof (struct Elf, state.elf64.scns))
+			     ? &elf->state.elf32.scns
+			     : &elf->state.elf64.scns);
+
+	do
+	  {
+	    /* Free all separately allocated section headers.  */
+	    size_t cnt = list->max;
+
+	    while (cnt-- > 0)
+	      {
+		/* These pointers can be NULL; it's safe to use
+		   'free' since it will check for this.  */
+		Elf_Scn *scn = &list->data[cnt];
+		Elf_Data_List *runp;
+
+		if ((scn->shdr_flags & ELF_F_MALLOCED) != 0)
+		  /* It doesn't matter which pointer.  */
+		  free (scn->shdr.e32);
+
+		/* Free zdata if uncompressed, but not yet used as
+		   rawdata_base.  If it is already used it will be
+		   freed below.  */
+		if (scn->zdata_base != scn->rawdata_base)
+		  free (scn->zdata_base);
+
+		/* If the file has the same byte order and the
+		   architecture doesn't require overly stringent
+		   alignment the raw data buffer is the same as the
+		   one used for presenting to the caller.  */
+		if (scn->data_base != scn->rawdata_base)
+		  free (scn->data_base);
+
+		/* The section data is allocated if we couldn't mmap
+		   the file.  Or if we had to decompress.  */
+		if (elf->map_address == NULL
+		    || scn->rawdata_base == scn->zdata_base
+		    || (scn->flags & ELF_F_MALLOCED) != 0)
+		  free (scn->rawdata_base);
+
+		/* Free the list of data buffers for the section.
+		   We don't free the buffers themselves since this
+		   is the users job.  */
+		runp = scn->data_list.next;
+		while (runp != NULL)
+		  {
+		    Elf_Data_List *oldp = runp;
+		    runp = runp->next;
+		    if ((oldp->flags & ELF_F_MALLOCED) != 0)
+		      free (oldp);
+		  }
+	      }
+
+	    /* Free the memory for the array.  */
+	    Elf_ScnList *oldp = list;
+	    list = list->next;
+	    assert (list == NULL || oldp->cnt == oldp->max);
+	    if (oldp != (elf->class == ELFCLASS32
+			 || (offsetof (struct Elf, state.elf32.scns)
+			     == offsetof (struct Elf, state.elf64.scns))
+			 ? &elf->state.elf32.scns
+			 : &elf->state.elf64.scns))
+	      free (oldp);
+	  }
+	while (list != NULL);
+      }
+
+      /* Free the section header.  */
+      if (elf->state.elf.shdr_malloced  != 0)
+	free (elf->class == ELFCLASS32
+	      || (offsetof (struct Elf, state.elf32.shdr)
+		  == offsetof (struct Elf, state.elf64.shdr))
+	      ? (void *) elf->state.elf32.shdr
+	      : (void *) elf->state.elf64.shdr);
+
+      /* Free the program header.  */
+      if ((elf->state.elf.phdr_flags & ELF_F_MALLOCED) != 0)
+	free (elf->class == ELFCLASS32
+	      || (offsetof (struct Elf, state.elf32.phdr)
+		  == offsetof (struct Elf, state.elf64.phdr))
+	      ? (void *) elf->state.elf32.phdr
+	      : (void *) elf->state.elf64.phdr);
+      break;
+
+    default:
+      break;
+    }
+
+  if (elf->map_address != NULL && parent == NULL)
+    {
+      /* The file was read or mapped for this descriptor.  */
+      if ((elf->flags & ELF_F_MALLOCED) != 0)
+	free (elf->map_address);
+      else if ((elf->flags & ELF_F_MMAPPED) != 0)
+	munmap (elf->map_address, elf->maximum_size);
+    }
+
+  rwlock_unlock (elf->lock);
+  rwlock_fini (elf->lock);
+
+  /* Finally the descriptor itself.  */
+  free (elf);
+
+  return (parent != NULL && parent->ref_count == 0
+	  ? INTUSE(elf_end) (parent) : 0);
+}
+INTDEF(elf_end)