/* Test program for getting symbol table from vdso module.

   Copyright (C) 2014 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 the GNU General Public License as published by

   the Free Software Foundation; either version 3 of the License, or

   (at your option) any later version.

   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 a copy of the GNU General Public License

   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include <config.h>

#include <assert.h>

#include <errno.h>

#include <inttypes.h>

#include <stdio.h>

#include <string.h>

#include <sys/types.h>

#include <unistd.h>

#include ELFUTILS_HEADER(dwfl)

#include "system.h"

#ifndef __linux__

int

main (int argc __attribute__ ((unused)), char **argv __attribute__ ((unused)))

{

  printf ("Getting the vdso is unsupported.\n");

  return 77;

}

#else /* __linux__ */

static int vdso_syms = 0;

static int

module_callback (Dwfl_Module *mod, void **userdata __attribute__((unused)),

		 const char *name, Dwarf_Addr start __attribute__((unused)),

		 void *arg __attribute__((unused)))

{

  /* We can only recognize the vdso by inspecting the "magic name".  */

  printf ("module name: %s\n", name);

  if (strncmp ("[vdso: ", name, 7) == 0)

    {

      vdso_syms = dwfl_module_getsymtab (mod);

      printf ("vdso syms: %d\n", vdso_syms);

      if (vdso_syms < 0)

	error (2, 0, "dwfl_module_getsymtab: %s", dwfl_errmsg (-1));

      for (int i = 0; i < vdso_syms; i++)

	{

	  GElf_Sym sym;

	  GElf_Addr addr;

	  const char *sname = dwfl_module_getsym_info (mod, i, &sym, &addr,

						       NULL, NULL, NULL);

	  assert (sname != NULL);

	  printf ("%d: '%s' %" PRIx64 " (%" PRIx64 ")\n",

		  i, sname, sym.st_value, addr);

	}

    }

  return DWARF_CB_OK;

}

int

main (int argc __attribute__ ((unused)), char **argv __attribute__ ((unused)))

{

  static char *debuginfo_path;

  static const Dwfl_Callbacks proc_callbacks =

    {

      .find_debuginfo = dwfl_standard_find_debuginfo,

      .debuginfo_path = &debuginfo_path,

      .find_elf = dwfl_linux_proc_find_elf,

    };

  Dwfl *dwfl = dwfl_begin (&proc_callbacks);

  if (dwfl == NULL)

    error (2, 0, "dwfl_begin: %s", dwfl_errmsg (-1));

  /* Take ourself as "arbitrary" process to inspect.  This should work

     even with "restricted ptrace".  */

  pid_t pid = getpid();

  int result = dwfl_linux_proc_report (dwfl, pid);

  if (result < 0)

    error (2, 0, "dwfl_linux_proc_report: %s", dwfl_errmsg (-1));

  else if (result > 0)

    error (2, result, "dwfl_linux_proc_report");

  /* Also explicitly attach for older kernels (cannot read vdso otherwise).  */

  result = dwfl_linux_proc_attach (dwfl, pid, false);

  if (result < 0)

    error (2, 0, "dwfl_linux_proc_attach: %s", dwfl_errmsg (-1));

  else if (result > 0)

    error (2, result, "dwfl_linux_proc_attach");

  if (dwfl_report_end (dwfl, NULL, NULL) != 0)

    error (2, 0, "dwfl_report_end: %s", dwfl_errmsg (-1));

  if (dwfl_getmodules (dwfl, module_callback, NULL, 0) != 0)

    error (1, 0, "dwfl_getmodules: %s", dwfl_errmsg (-1));

  /* No symbols is ok, then we haven't seen the vdso at all on this arch.  */

  return vdso_syms >= 0 ? 0 : -1;

}

#endif /* ! __linux__ */