1 /* Test if an executable can read from rtld_global_ro._dl_cache_line_size.
2    Copyright (C) 2020-2021 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 <stdio.h>
20 #include <stdint.h>
21 #include <inttypes.h>
22 #include <sys/auxv.h>
23 #include <ldsodefs.h>
24 #include <errno.h>
25 
26 /* errnop is required in order to work around BZ #20802.  */
27 int
test_cache(int * errnop)28 test_cache (int *errnop)
29 {
30   int cls1 = GLRO (dl_cache_line_size);
31   errno = *errnop;
32   uint64_t cls2 = getauxval (AT_DCACHEBSIZE);
33   *errnop = errno;
34 
35   printf ("AT_DCACHEBSIZE      = %" PRIu64 " B\n", cls2);
36   printf ("_dl_cache_line_size = %d B\n", cls1);
37 
38   if (cls1 != cls2)
39     {
40       printf ("error: _dl_cache_line_size != AT_DCACHEBSIZE\n");
41       return 1;
42     }
43 
44   return 0;
45 }
46