1/* Test disabling of rseq registration via tunable.
2 Copyright (C) 2021-2024 Free Software Foundation, Inc.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <errno.h>
19#include <stdio.h>
20#include <support/check.h>
21#include <support/namespace.h>
22#include <support/xthread.h>
23#include <sysdep.h>
24#include <thread_pointer.h>
25#include <sys/rseq.h>
26#include <unistd.h>
27
28#ifdef RSEQ_SIG
29
30/* Check that rseq can be registered and has not been taken by glibc. */
31static void
32check_rseq_disabled (void)
33{
34 struct pthread *pd = THREAD_SELF;
35
36 TEST_COMPARE (__rseq_flags, 0);
37 TEST_VERIFY ((char *) __thread_pointer () + __rseq_offset
38 == (char *) &pd->rseq_area);
39 TEST_COMPARE (__rseq_size, 0);
40 TEST_COMPARE ((int) pd->rseq_area.cpu_id, RSEQ_CPU_ID_REGISTRATION_FAILED);
41
42 int ret = syscall (__NR_rseq, &pd->rseq_area, sizeof (pd->rseq_area),
43 0, RSEQ_SIG);
44 if (ret == 0)
45 {
46 ret = syscall (__NR_rseq, &pd->rseq_area, sizeof (pd->rseq_area),
47 RSEQ_FLAG_UNREGISTER, RSEQ_SIG);
48 TEST_COMPARE (ret, 0);
49 pd->rseq_area.cpu_id = RSEQ_CPU_ID_REGISTRATION_FAILED;
50 }
51 else
52 {
53 TEST_VERIFY (errno != -EINVAL);
54 TEST_VERIFY (errno != -EBUSY);
55 }
56}
57
58static void *
59thread_func (void *ignored)
60{
61 check_rseq_disabled ();
62 return NULL;
63}
64
65static void
66proc_func (void *ignored)
67{
68 check_rseq_disabled ();
69}
70
71static int
72do_test (void)
73{
74 puts (s: "info: checking main thread");
75 check_rseq_disabled ();
76
77 puts (s: "info: checking main thread (2)");
78 check_rseq_disabled ();
79
80 puts (s: "info: checking new thread");
81 xpthread_join (thr: xpthread_create (NULL, thread_func, NULL));
82
83 puts (s: "info: checking subprocess");
84 support_isolate_in_subprocess (callback: proc_func, NULL);
85
86 return 0;
87}
88#else /* !RSEQ_SIG */
89static int
90do_test (void)
91{
92 FAIL_UNSUPPORTED ("glibc does not define RSEQ_SIG, skipping test");
93}
94#endif
95
96#include <support/test-driver.c>
97

source code of glibc/sysdeps/unix/sysv/linux/tst-rseq-disable.c