glibc/elf/tst-audit23.c

/* Check for expected la_objopen and la_objeclose for all objects.
   Copyright (C) 2022 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
   <https://www.gnu.org/licenses/>.  */

#include <array_length.h>
#include <errno.h>
#include <getopt.h>
#include <link.h>
#include <limits.h>
#include <inttypes.h>
#include <gnu/lib-names.h>
#include <string.h>
#include <stdlib.h>
#include <support/capture_subprocess.h>
#include <support/check.h>
#include <support/xstdio.h>
#include <support/xdlfcn.h>
#include <support/support.h>

static int restart;
#define CMDLINE_OPTIONS \
  { "restart", no_argument, &restart, 1 },

static int
handle_restart (void)
{
  xdlopen ("tst-audit23mod.so", RTLD_NOW);
  xdlmopen (LM_ID_NEWLM, LIBC_SO, RTLD_NOW);

  return 0;
}

static inline bool
startswith (const char *str, const char *pre)
{
  size_t lenpre = strlen (pre);
  size_t lenstr = strlen (str);
  return lenstr >= lenpre && memcmp (pre, str, lenpre) == 0;
}

static inline bool
is_vdso (const char *str)
{
  return startswith (str, "linux-gate")
	 || startswith (str, "linux-vdso");
}

static int
do_test (int argc, char *argv[])
{
  /* We must have either:
     - One or four parameters left if called initially:
       + path to ld.so         optional
       + "--library-path"      optional
       + the library path      optional
       + the application name  */
  if (restart)
    return handle_restart ();

  char *spargv[9];
  TEST_VERIFY_EXIT (((argc - 1) + 3) < array_length (spargv));
  int i = 0;
  for (; i < argc - 1; i++)
    spargv[i] = argv[i + 1];
  spargv[i++] = (char *) "--direct";
  spargv[i++] = (char *) "--restart";
  spargv[i] = NULL;

  setenv ("LD_AUDIT", "tst-auditmod23.so", 0);
  struct support_capture_subprocess result
    = support_capture_subprogram (spargv[0], spargv);
  support_capture_subprocess_check (&result, "tst-audit22", 0, sc_allow_stderr);

  /* The expected la_objopen/la_objclose:
     1. executable
     2. loader
     3. libc.so
     4. tst-audit23mod.so
     5. libc.so (LM_ID_NEWLM).
     6. vdso (optional and ignored).  */
  enum { max_objs = 6 };
  struct la_obj_t
  {
    char *lname;
    uintptr_t laddr;
    Lmid_t lmid;
    uintptr_t cookie;
    uintptr_t namespace;
    bool closed;
  } objs[max_objs] = { [0 ... max_objs-1] = { .closed = false } };
  size_t nobjs = 0;

  /* The expected namespaces are one for the audit module, one for the
     application, and another for the dlmopen on handle_restart.  */
  enum { max_ns = 3 };
  uintptr_t acts[max_ns] = { 0 };
  size_t nacts = 0;
  int last_act = -1;
  uintptr_t last_act_cookie = -1;
  bool seen_first_objclose = false;

  FILE *out = fmemopen (result.err.buffer, result.err.length, "r");
  TEST_VERIFY (out != NULL);
  char *buffer = NULL;
  size_t buffer_length = 0;
  while (xgetline (&buffer, &buffer_length, out))
    {
      *strchrnul (buffer, '\n') = '\0';
      printf ("info: subprocess output: %s\n", buffer);

      if (startswith (buffer, "la_activity: "))
	{
	  uintptr_t cookie;
	  int this_act;
	  int r = sscanf (buffer, "la_activity: %d %"SCNxPTR"", &this_act,
			  &cookie);
	  TEST_COMPARE (r, 2);

	  if (this_act == LA_ACT_ADD && acts[nacts] != cookie)
	    {
	      /* The cookie identifies the object at the head of the
		 link map, so we only add a new namespace if it
		 changes from the previous one.  This works since
		 dlmopen is the last in the test body.  */
	      if (cookie != last_act_cookie && last_act_cookie != -1)
		TEST_COMPARE (last_act, LA_ACT_CONSISTENT);

	      acts[nacts++] = cookie;
	      last_act_cookie = cookie;
	    }
	  /* LA_ACT_DELETE is called multiple times for each
	     namespace, depending on destruction order.  */
	  else if (this_act == LA_ACT_DELETE)
	    last_act_cookie = cookie;
	  else if (this_act == LA_ACT_CONSISTENT)
	    {
	      TEST_COMPARE (cookie, last_act_cookie);
	      last_act_cookie = -1;

	      /* LA_ACT_DELETE must always be followed by an la_objclose.  */
	      if (last_act == LA_ACT_DELETE)
		TEST_COMPARE (seen_first_objclose, true);
	      else
		TEST_COMPARE (last_act, LA_ACT_ADD);
	    }

	  last_act = this_act;
	  seen_first_objclose = false;
	}
      else if (startswith (buffer, "la_objopen: "))
	{
	  char *lname;
	  uintptr_t laddr;
	  Lmid_t lmid;
	  uintptr_t cookie;
	  int r = sscanf (buffer, "la_objopen: %"SCNxPTR"  %ms %"SCNxPTR" %ld",
			  &cookie, &lname, &laddr, &lmid);
	  TEST_COMPARE (r, 4);

	  /* la_objclose is not triggered by vDSO because glibc does not
	     unload it.  */
	  if (is_vdso (lname))
	    continue;
	  if (nobjs == max_objs)
	    FAIL_EXIT1 ("non expected la_objopen: %s %"PRIxPTR" %ld",
			lname, laddr, lmid);
	  objs[nobjs].lname = lname;
	  objs[nobjs].laddr = laddr;
	  objs[nobjs].lmid = lmid;
	  objs[nobjs].cookie = cookie;
	  objs[nobjs].namespace = last_act_cookie;
	  objs[nobjs].closed = false;
	  nobjs++;

	  /* This indirectly checks that la_objopen always comes before
	     la_objclose btween la_activity calls.  */
	  seen_first_objclose = false;
	}
      else if (startswith (buffer, "la_objclose: "))
	{
	  char *lname;
	  uintptr_t laddr;
	  Lmid_t lmid;
	  uintptr_t cookie;
	  int r = sscanf (buffer, "la_objclose: %"SCNxPTR" %ms %"SCNxPTR" %ld",
			  &cookie, &lname, &laddr, &lmid);
	  TEST_COMPARE (r, 4);

	  for (size_t i = 0; i < nobjs; i++)
	    {
	      if (strcmp (lname, objs[i].lname) == 0 && lmid == objs[i].lmid)
		{
		  TEST_COMPARE (objs[i].closed, false);
		  TEST_COMPARE (objs[i].cookie, cookie);
		  if (objs[i].namespace == -1)
		    /* No LA_ACT_ADD before the first la_objopen call.  */
		    TEST_COMPARE (acts[0], last_act_cookie);
		  else
		    TEST_COMPARE (objs[i].namespace, last_act_cookie);
		  objs[i].closed = true;
		  break;
		}
	    }

	  /* la_objclose should be called after la_activity(LA_ACT_DELETE) for
	     the closed object's namespace.  */
	  TEST_COMPARE (last_act, LA_ACT_DELETE);
	  seen_first_objclose = true;
	}
    }

  for (size_t i = 0; i < nobjs; i++)
    {
      TEST_COMPARE (objs[i].closed, true);
      free (objs[i].lname);
    }

  /* la_activity(LA_ACT_CONSISTENT) should be the last callback received.
     Since only one link map may be not-CONSISTENT at a time, this also
     ensures la_activity(LA_ACT_CONSISTENT) is the last callback received
     for every namespace.  */
  TEST_COMPARE (last_act, LA_ACT_CONSISTENT);

  free (buffer);
  xfclose (out);

  return 0;
}

#define TEST_FUNCTION_ARGV do_test
#include <support/test-driver.c>