elf/tst-audit22.c

   1 /* Check DTAUDIT and vDSO interaction.
   2    Copyright (C) 2021-2022 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 <errno.h>
  20 #include <getopt.h>
  21 #include <limits.h>
  22 #include <inttypes.h>
  23 #include <string.h>
  24 #include <stdlib.h>
  25 #include <support/capture_subprocess.h>
  26 #include <support/check.h>
  27 #include <support/xstdio.h>
  28 #include <support/support.h>
  29 #include <sys/auxv.h>
  30
  31 static int restart;
  32 #define CMDLINE_OPTIONS \
  33   { "restart", no_argument, &restart, 1 },
  34
  35 static uintptr_t vdso_addr;
  36
  37 static int
  38 handle_restart (void)
  39 {
  40   fprintf (stderr, "vdso: %p\n", (void*) vdso_addr);
  41   return 0;
  42 }
  43
  44 static uintptr_t
  45 parse_address (const char *str)
  46 {
  47   void *r;
  48   TEST_COMPARE (sscanf (str, "%p\n", &r), 1);
  49   return (uintptr_t) r;
  50 }
  51
  52 static inline bool
  53 startswith (const char *str, const char *pre)
  54 {
  55   size_t lenpre = strlen (pre);
  56   size_t lenstr = strlen (str);
  57   return lenstr >= lenpre && memcmp (pre, str, lenpre) == 0;
  58 }
  59
  60 static int
  61 do_test (int argc, char *argv[])
  62 {
  63   vdso_addr = getauxval (AT_SYSINFO_EHDR);
  64   if (vdso_addr == 0)
  65     FAIL_UNSUPPORTED ("getauxval (AT_SYSINFO_EHDR) returned 0");
  66
  67   /* We must have either:
  68      - One our fource parameters left if called initially:
  69        + path to ld.so         optional
  70        + "--library-path"      optional
  71        + the library path      optional
  72        + the application name  */
  73   if (restart)
  74     return handle_restart ();
  75
  76   char *spargv[9];
  77   int i = 0;
  78   for (; i < argc - 1; i++)
  79     spargv[i] = argv[i + 1];
  80   spargv[i++] = (char *) "--direct";
  81   spargv[i++] = (char *) "--restart";
  82   spargv[i] = NULL;
  83
  84   setenv ("LD_AUDIT", "tst-auditmod22.so", 0);
  85   struct support_capture_subprocess result
  86     = support_capture_subprogram (spargv[0], spargv);
  87   support_capture_subprocess_check (&result, "tst-audit22", 0, sc_allow_stderr);
  88
  89   /* The respawned process should always print the vDSO address (otherwise it
  90      will fails as unsupported).  However, on some architectures the audit
  91      module might see the vDSO with l_addr being 0, meaning a fixed mapping
  92      (linux-gate.so).  In this case we don't check its value against
  93      AT_SYSINFO_EHDR one.  */
  94   uintptr_t vdso_process = 0;
  95   bool vdso_audit_found = false;
  96   uintptr_t vdso_audit = 0;
  97
  98   FILE *out = fmemopen (result.err.buffer, result.err.length, "r");
  99   TEST_VERIFY (out != NULL);
 100   char *buffer = NULL;
 101   size_t buffer_length = 0;
 102   while (xgetline (&buffer, &buffer_length, out))
 103     {
 104       if (startswith (buffer, "vdso: "))
 105         vdso_process = parse_address (buffer + strlen ("vdso: "));
 106       else if (startswith (buffer, "vdso found: "))
 107         {
 108           vdso_audit = parse_address (buffer + strlen ("vdso found: "));
 109           vdso_audit_found = true;
 110         }
 111     }
 112
 113   TEST_COMPARE (vdso_audit_found, true);
 114   if (vdso_audit != 0)
 115     TEST_COMPARE (vdso_process, vdso_audit);
 116
 117   free (buffer);
 118   xfclose (out);
 119
 120   return 0;
 121 }
 122
 123 #define TEST_FUNCTION_ARGV do_test
 124 #include <support/test-driver.c>