elf/tst-auditmod22.c

   1 /* Check DTAUDIT and vDSO interaction.
   2    Copyright (C) 2021-2024 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <link.h>
  20 #include <inttypes.h>
  21 #include <stdbool.h>
  22 #include <string.h>
  23 #include <stdio.h>
  24 #include <sys/auxv.h>
  25
  26 static inline bool
  27 startswith (const char *str, const char *pre)
  28 {
  29   size_t lenpre = strlen (pre);
  30   size_t lenstr = strlen (str);
  31   return lenstr < lenpre ? false : memcmp (pre, str, lenpre) == 0;
  32 }
  33
  34 unsigned int
  35 la_version (unsigned int version)
  36 {
  37   return LAV_CURRENT;
  38 }
  39
  40 unsigned int
  41 la_objopen (struct link_map *map, Lmid_t lmid, uintptr_t *cookie)
  42 {
  43   /* The linux-gate.so is placed at a fixed address, thus l_addr being 0,
  44      and it might be the value reported as the AT_SYSINFO_EHDR.  */
  45   if (map->l_addr == 0 && startswith (map->l_name, "linux-gate.so"))
  46     fprintf (stderr, "vdso found: %p\n", NULL);
  47   else if (map->l_addr == getauxval (AT_SYSINFO_EHDR))
  48     fprintf (stderr, "vdso found: %p\n", (void*) map->l_addr);
  49
  50   return 0;
  51 }