1 files changed, 110 insertions, 0 deletions
diff --git a/libelf/gelf_getauxv.c b/libelf/gelf_getauxv.c
new file mode 100644
index 00000000..a2f04e7f
--- /dev/null
+++ b/libelf/gelf_getauxv.c
@@ -0,0 +1,110 @@
+/* Get information from auxiliary vector at the given index.
+   Copyright (C) 2007 Red Hat, Inc.
+   This file is part of elfutils.
+
+   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 <gelf.h>
+#include <string.h>
+
+#include "libelfP.h"
+
+
+GElf_auxv_t *
+gelf_getauxv (data, ndx, dst)
+     Elf_Data *data;
+     int ndx;
+     GElf_auxv_t *dst;
+{
+  Elf_Data_Scn *data_scn = (Elf_Data_Scn *) data;
+  GElf_auxv_t *result = NULL;
+  Elf *elf;
+
+  if (data_scn == NULL)
+    return NULL;
+
+  if (unlikely (data_scn->d.d_type != ELF_T_AUXV))
+    {
+      __libelf_seterrno (ELF_E_INVALID_HANDLE);
+      return NULL;
+    }
+
+  elf = data_scn->s->elf;
+
+  rwlock_rdlock (elf->lock);
+
+  /* This is the one place where we have to take advantage of the fact
+     that an `Elf_Data' pointer is also a pointer to `Elf_Data_Scn'.
+     The interface is broken so that it requires this hack.  */
+  if (elf->class == ELFCLASS32)
+    {
+      Elf32_auxv_t *src;
+
+      /* Here it gets a bit more complicated.  The format of the vector
+	 entries has to be converted.  The user better have provided a
+	 buffer where we can store the information.  While copying the data
+	 we convert the format.  */
+      if (unlikely ((ndx + 1) * sizeof (Elf32_auxv_t) > data_scn->d.d_size))
+	{
+	  __libelf_seterrno (ELF_E_INVALID_INDEX);
+	  goto out;
+	}
+
+      src = &((Elf32_auxv_t *) data_scn->d.d_buf)[ndx];
+
+      /* This might look like a simple copy operation but it's
+	 not.  There are zero- and sign-extensions going on.  */
+      dst->a_type = src->a_type;
+      dst->a_un.a_val = src->a_un.a_val;
+    }
+  else
+    {
+      /* If this is a 64 bit object it's easy.  */
+      assert (sizeof (GElf_auxv_t) == sizeof (Elf64_auxv_t));
+
+      /* The data is already in the correct form.  Just make sure the
+	 index is OK.  */
+      if (unlikely ((ndx + 1) * sizeof (GElf_auxv_t) > data_scn->d.d_size))
+	{
+	  __libelf_seterrno (ELF_E_INVALID_INDEX);
+	  goto out;
+	}
+
+      memcpy (dst, data_scn->d.d_buf + ndx * sizeof (GElf_auxv_t),
+	      sizeof (GElf_auxv_t));
+    }
+
+  result = dst;
+
+ out:
+  rwlock_unlock (elf->lock);
+
+  return result;
+}