1/* Test for large alignment in TLS blocks (extern case), BZ#18383.
2 Copyright (C) 2015-2022 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 <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
31extern __thread int tdata1;
32extern __thread int tdata2;
33extern __thread int tdata3;
34extern __thread int tbss1;
35extern __thread int tbss2;
36extern __thread int tbss3;
37
38static int
39test_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 (format: "%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 (format: "%s value %d should be %d\n", which, got, value);
51 return 1;
52 }
53
54 return misalign != 0;
55}
56
57static int
58do_test (void)
59{
60 int fail = 0;
61
62 fail |= test_one (which: "tdata1", alignment: 4, var: &tdata1, value: 1);
63 fail |= test_one (which: "tdata2", alignment: 0x10, var: &tdata2, value: 2);
64 fail |= test_one (which: "tdata3", alignment: 0x1000, var: &tdata3, value: 4);
65
66 fail |= test_one (which: "tbss1", alignment: 4, var: &tbss1, value: 0);
67 fail |= test_one (which: "tbss2", alignment: 0x10, var: &tbss2, value: 0);
68 fail |= test_one (which: "tbss3", alignment: 0x1000, var: &tbss3, value: 0);
69
70 return fail ? EXIT_FAILURE : EXIT_SUCCESS;
71}
72
73#include <support/test-driver.c>
74

source code of glibc/elf/tst-tlsalign-extern.c