libdwfl/argp-std.c

/* Standard argp argument parsers for tools using libdwfl.
   Copyright (C) 2005, 2007, 2008 Red Hat, Inc.
   This file is part of Red Hat elfutils.

   Red Hat elfutils 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; version 2 of the License.

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   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.

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   with Red Hat elfutils; if not, write to the Free Software Foundation,
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   this file solely under the GPL without exception.

   Red Hat elfutils is an included package of the Open Invention Network.
   An included package of the Open Invention Network is a package for which
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#include "libdwflP.h"
#include <argp.h>
#include <stdlib.h>
#include <assert.h>
#include <libintl.h>
#include <fcntl.h>
#include <unistd.h>

/* gettext helper macros.  */
#define _(Str) dgettext ("elfutils", Str)


#define OPT_DEBUGINFO	0x100
#define OPT_COREFILE	0x101

static const struct argp_option options[] =
{
  { NULL, 0, NULL, 0, N_("Input selection options:"), 0 },
  { "executable", 'e', "FILE", 0, N_("Find addresses in FILE"), 0 },
  { "core", OPT_COREFILE, "COREFILE", 0,
    N_("Find addresses from signatures found in COREFILE"), 0 },
  { "pid", 'p', "PID", 0,
    N_("Find addresses in files mapped into process PID"), 0 },
  { "linux-process-map", 'M', "FILE", 0,
    N_("Find addresses in files mapped as read from FILE"
       " in Linux /proc/PID/maps format"), 0 },
  { "kernel", 'k', NULL, 0, N_("Find addresses in the running kernel"), 0 },
  { "offline-kernel", 'K', "RELEASE", OPTION_ARG_OPTIONAL,
    N_("Kernel with all modules"), 0 },
  { "debuginfo-path", OPT_DEBUGINFO, "PATH", 0,
    N_("Search path for separate debuginfo files"), 0 },
  { NULL, 0, NULL, 0, NULL, 0 }
};

static char *debuginfo_path;

static const Dwfl_Callbacks offline_callbacks =
  {
    .find_debuginfo = INTUSE(dwfl_standard_find_debuginfo),
    .debuginfo_path = &debuginfo_path,

    .section_address = INTUSE(dwfl_offline_section_address),

    /* We use this table for core files too.  */
    .find_elf = INTUSE(dwfl_build_id_find_elf),
  };

static const Dwfl_Callbacks proc_callbacks =
  {
    .find_debuginfo = INTUSE(dwfl_standard_find_debuginfo),
    .debuginfo_path = &debuginfo_path,

    .find_elf = INTUSE(dwfl_linux_proc_find_elf),
  };

static const Dwfl_Callbacks kernel_callbacks =
  {
    .find_debuginfo = INTUSE(dwfl_standard_find_debuginfo),
    .debuginfo_path = &debuginfo_path,

    .find_elf = INTUSE(dwfl_linux_kernel_find_elf),
    .section_address = INTUSE(dwfl_linux_kernel_module_section_address),
  };

static error_t
parse_opt (int key, char *arg, struct argp_state *state)
{
  inline void failure (Dwfl *dwfl, int errnum, const char *msg)
    {
      if (dwfl != NULL)
	dwfl_end (dwfl);
      if (errnum == -1)
	argp_failure (state, EXIT_FAILURE, 0, "%s: %s",
		      msg, INTUSE(dwfl_errmsg) (-1));
      else
	argp_failure (state, EXIT_FAILURE, errnum, "%s", msg);
    }
  inline error_t fail (Dwfl *dwfl, int errnum, const char *msg)
    {
      failure (dwfl, errnum, msg);
      return errnum == -1 ? EIO : errnum;
    }

  switch (key)
    {
    case OPT_DEBUGINFO:
      debuginfo_path = arg;
      break;

    case 'e':
      {
	Dwfl *dwfl = state->hook;
	if (dwfl == NULL)
	  {
	    dwfl = INTUSE(dwfl_begin) (&offline_callbacks);
	    if (dwfl == NULL)
	      return fail (dwfl, -1, arg);
	    state->hook = dwfl;

	    /* Start at zero so if there is just one -e foo.so,
	       the DSO is shown without address bias.  */
	    dwfl->offline_next_address = 0;
	  }
	if (dwfl->callbacks == &offline_callbacks)
	  {
	    if (INTUSE(dwfl_report_offline) (dwfl, "", arg, -1) == NULL)
	      return fail (dwfl, -1, arg);
	    state->hook = dwfl;
	  }
	else
	  {
	  toomany:
	    argp_error (state, "%s",
			_("only one of -e, -p, -k, -K, or --core allowed"));
	    return EINVAL;
	  }
      }
      break;

    case 'p':
      if (state->hook == NULL)
	{
	  Dwfl *dwfl = INTUSE(dwfl_begin) (&proc_callbacks);
	  int result = INTUSE(dwfl_linux_proc_report) (dwfl, atoi (arg));
	  if (result != 0)
	    return fail (dwfl, result, arg);
	  state->hook = dwfl;
	}
      else
	goto toomany;
      break;

    case 'M':
      if (state->hook == NULL)
	{
	  FILE *f = fopen (arg, "r");
	  if (f == NULL)
	  nofile:
	    {
	      int code = errno;
	      argp_failure (state, EXIT_FAILURE, code,
			    "cannot open '%s'", arg);
	      return code;
	    }
	  Dwfl *dwfl = INTUSE(dwfl_begin) (&proc_callbacks);
	  int result = INTUSE(dwfl_linux_proc_maps_report) (dwfl, f);
	  fclose (f);
	  if (result != 0)
	    return fail (dwfl, result, arg);
	  state->hook = dwfl;
	}
      else
	goto toomany;
      break;

    case OPT_COREFILE:
      {
	Dwfl *dwfl = state->hook;
	if (dwfl == NULL)
	  state->hook = dwfl = INTUSE(dwfl_begin) (&offline_callbacks);
	/* Permit -e and --core together.  */
	else if (dwfl->callbacks != &offline_callbacks)
	  goto toomany;

	int fd = open64 (arg, O_RDONLY);
	if (fd < 0)
	  goto nofile;

	Elf *core = elf_begin (fd, ELF_C_READ_MMAP_PRIVATE, NULL);
	if (core == NULL)
	  {
	    close (fd);
	    argp_failure (state, EXIT_FAILURE, 0,
			  _("cannot read ELF core file: %s"),
			  elf_errmsg (-1));
	    return EIO;
	  }

	GElf_Ehdr ehdr;
	int result = INTUSE(dwfl_core_file_report) (dwfl, core,
						    gelf_getehdr (core, &ehdr));
	if (result < 0)
	  {
	    elf_end (core);
	    close (fd);
	    return fail (dwfl, result, arg);
	  }

	/* From now we leak FD and CORE.  */

	if (result == 0)
	  {
	    argp_failure (state, EXIT_FAILURE, 0,
			  _("No modules recognized in core file"));
	    return ENOENT;
	  }
      }
      break;

    case 'k':
      if (state->hook == NULL)
	{
	  Dwfl *dwfl = INTUSE(dwfl_begin) (&kernel_callbacks);
	  int result = INTUSE(dwfl_linux_kernel_report_kernel) (dwfl);
	  if (result != 0)
	    return fail (dwfl, result, _("cannot load kernel symbols"));
	  result = INTUSE(dwfl_linux_kernel_report_modules) (dwfl);
	  if (result != 0)
	    /* Non-fatal to have no modules since we do have the kernel.  */
	    failure (dwfl, result, _("cannot find kernel modules"));
	  state->hook = dwfl;
	}
      else
	goto toomany;
      break;

    case 'K':
      if (state->hook == NULL)
	{
	  Dwfl *dwfl = INTUSE(dwfl_begin) (&offline_callbacks);
	  int result = INTUSE(dwfl_linux_kernel_report_offline) (dwfl, arg,
								 NULL);
	  if (result != 0)
	    return fail (dwfl, result, _("cannot find kernel or modules"));
	  state->hook = dwfl;
	}
      else
	goto toomany;
      break;

    case ARGP_KEY_SUCCESS:
      {
	Dwfl *dwfl = state->hook;

	if (dwfl == NULL)
	  {
	    /* Default if no -e, -p, or -k, is "-e a.out".  */
	    arg = "a.out";
	    dwfl = INTUSE(dwfl_begin) (&offline_callbacks);
	    if (INTUSE(dwfl_report_offline) (dwfl, "", arg, -1) == NULL)
	      return fail (dwfl, -1, arg);
	    state->hook = dwfl;
	  }

	/* One of the three flavors has done dwfl_begin and some reporting
	   if we got here.  Tie up the Dwfl and return it to the caller of
	   argp_parse.  */

	int result = INTUSE(dwfl_report_end) (dwfl, NULL, NULL);
	assert (result == 0);
      }
      break;

    case ARGP_KEY_ERROR:
      dwfl_end (state->hook);
      state->hook = NULL;
      break;

    default:
      return ARGP_ERR_UNKNOWN;
    }

  /* Update the input all along, so a parent parser can see it.  */
  *(Dwfl **) state->input = state->hook;
  return 0;
}

static const struct argp libdwfl_argp =
  { .options = options, .parser = parse_opt };

const struct argp *
dwfl_standard_argp (void)
{
  return &libdwfl_argp;
}

#ifdef _MUDFLAP
/* In the absence of a mudflap wrapper for argp_parse, or a libc compiled
   with -fmudflap, we'll see spurious errors for using the struct argp_state
   on argp_parse's stack.  */

void __attribute__ ((constructor))
__libdwfl_argp_mudflap_options (void)
{
  __mf_set_options ("-heur-stack-bound");
}
#endif