elf/tst-gnu2-tls2.c

   1 /* Test TLSDESC relocation.
   2    Copyright (C) 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    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <dlfcn.h>
  23 #include <pthread.h>
  24 #include <support/xdlfcn.h>
  25 #include <support/xthread.h>
  26 #include <support/check.h>
  27 #include <support/test-driver.h>
  28 #include "tst-gnu2-tls2.h"
  29
  30 #ifndef IS_SUPPORTED
  31 # define IS_SUPPORTED() true
  32 #endif
  33
  34 /* An architecture can define it to clobber caller-saved registers in
  35    malloc below to verify that the implicit TLSDESC call won't change
  36    caller-saved registers.  */
  37 #ifndef PREPARE_MALLOC
  38 # define PREPARE_MALLOC()
  39 #endif
  40
  41 extern void * __libc_malloc (size_t);
  42
  43 size_t malloc_counter = 0;
  44
  45 void *
  46 malloc (size_t n)
  47 {
  48   PREPARE_MALLOC ();
  49   malloc_counter++;
  50   return __libc_malloc (n);
  51 }
  52
  53 static void *mod[3];
  54 #ifndef MOD
  55 # define MOD(i) "tst-gnu2-tls2mod" #i ".so"
  56 #endif
  57 static const char *modname[3] = { MOD(0), MOD(1), MOD(2) };
  58 #undef MOD
  59
  60 static void
  61 open_mod (int i)
  62 {
  63   mod[i] = xdlopen (modname[i], RTLD_LAZY);
  64   printf ("open %s\n", modname[i]);
  65 }
  66
  67 static void
  68 close_mod (int i)
  69 {
  70   xdlclose (mod[i]);
  71   mod[i] = NULL;
  72   printf ("close %s\n", modname[i]);
  73 }
  74
  75 static void
  76 access_mod (int i, const char *sym)
  77 {
  78   struct tls var = { -1, -1, -1, -1 };
  79   struct tls *(*f) (struct tls *) = xdlsym (mod[i], sym);
  80   /* Check that our malloc is called.  */
  81   malloc_counter = 0;
  82   struct tls *p = f (&var);
  83   TEST_VERIFY (malloc_counter != 0);
  84   printf ("access %s: %s() = %p\n", modname[i], sym, p);
  85   TEST_VERIFY_EXIT (memcmp (p, &var, sizeof (var)) == 0);
  86   ++(p->a);
  87 }
  88
  89 static void *
  90 start (void *arg)
  91 {
  92   /* The DTV generation is at the last dlopen of mod0 and the
  93      entry for mod1 is NULL.  */
  94
  95   open_mod (1); /* Reuse modid of mod1. Uses dynamic TLS.  */
  96
  97   /* Force the slow path in GNU2 TLS descriptor call.  */
  98   access_mod (1, "apply_tls");
  99
 100   return arg;
 101 }
 102
 103 static int
 104 do_test (void)
 105 {
 106   if (!IS_SUPPORTED ())
 107     return EXIT_UNSUPPORTED;
 108
 109   open_mod (0);
 110   open_mod (1);
 111   open_mod (2);
 112   close_mod (0);
 113   close_mod (1); /* Create modid gap at mod1.  */
 114   open_mod (0); /* Reuse modid of mod0, bump generation count.  */
 115
 116   /* Create a thread where DTV of mod1 is NULL.  */
 117   pthread_t t = xpthread_create (NULL, start, NULL);
 118   xpthread_join (t);
 119   return 0;
 120 }
 121
 122 #include <support/test-driver.c>