elf/tst-tlsalign-extern.c

   1 /* Test for large alignment in TLS blocks (extern case), BZ#18383.
   2    Copyright (C) 2015-2024 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 <stdint.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22
  23 /* This is the same as tst-tlsalign-static.c, except that it uses
  24    TLS variables that are defined in a separate translation unit
  25    (ts-tlsalign-vars.c).  It turned out that the cause of BZ#18383
  26    on ARM was actually an ARM assembler bug triggered by the ways of
  27    using .tdata/.tbss sections and relocs referring to them that GCC
  28    chooses when the variables are defined in the same translation
  29    unit that contains the references.  */
  30
  31 extern __thread int tdata1;
  32 extern __thread int tdata2;
  33 extern __thread int tdata3;
  34 extern __thread int tbss1;
  35 extern __thread int tbss2;
  36 extern __thread int tbss3;
  37
  38 static int
  39 test_one (const char *which, unsigned int alignment, int *var, int value)
  40 {
  41   uintptr_t addr = (uintptr_t) var;
  42   unsigned int misalign = addr & (alignment - 1);
  43
  44   printf ("%s TLS address %p %% %u = %u\n",
  45           which, (void *) var, alignment, misalign);
  46
  47   int got = *var;
  48   if (got != value)
  49     {
  50       printf ("%s value %d should be %d\n", which, got, value);
  51       return 1;
  52     }
  53
  54   return misalign != 0;
  55 }
  56
  57 static int
  58 do_test (void)
  59 {
  60   int fail = 0;
  61
  62   fail |= test_one ("tdata1", 4, &tdata1, 1);
  63   fail |= test_one ("tdata2", 0x10, &tdata2, 2);
  64   fail |= test_one ("tdata3", 0x1000, &tdata3, 4);
  65
  66   fail |= test_one ("tbss1", 4, &tbss1, 0);
  67   fail |= test_one ("tbss2", 0x10, &tbss2, 0);
  68   fail |= test_one ("tbss3", 0x1000, &tbss3, 0);
  69
  70   return fail ? EXIT_FAILURE : EXIT_SUCCESS;
  71 }
  72
  73 #include <support/test-driver.c>