sysdeps/unix/sysv/linux/tst-rseq-disable.c

   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.  */
  31 static void
  32 check_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
  58 static void *
  59 thread_func (void *ignored)
  60 {
  61   check_rseq_disabled ();
  62   return NULL;
  63 }
  64
  65 static void
  66 proc_func (void *ignored)
  67 {
  68   check_rseq_disabled ();
  69 }
  70
  71 static int
  72 do_test (void)
  73 {
  74   puts ("info: checking main thread");
  75   check_rseq_disabled ();
  76
  77   puts ("info: checking main thread (2)");
  78   check_rseq_disabled ();
  79
  80   puts ("info: checking new thread");
  81   xpthread_join (xpthread_create (NULL, thread_func, NULL));
  82
  83   puts ("info: checking subprocess");
  84   support_isolate_in_subprocess (proc_func, NULL);
  85
  86   return 0;
  87 }
  88 #else /* !RSEQ_SIG */
  89 static int
  90 do_test (void)
  91 {
  92   FAIL_UNSUPPORTED ("glibc does not define RSEQ_SIG, skipping test");
  93 }
  94 #endif
  95
  96 #include <support/test-driver.c>