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

   1 /* Test disabling of rseq registration via tunable.
   2    Copyright (C) 2021-2023 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 <unistd.h>
  26
  27 #ifdef RSEQ_SIG
  28
  29 /* Check that rseq can be registered and has not been taken by glibc.  */
  30 static void
  31 check_rseq_disabled (void)
  32 {
  33   struct pthread *pd = THREAD_SELF;
  34
  35   TEST_COMPARE (__rseq_flags, 0);
  36   TEST_VERIFY ((char *) __thread_pointer () + __rseq_offset
  37                == (char *) &pd->rseq_area);
  38   TEST_COMPARE (__rseq_size, 0);
  39   TEST_COMPARE ((int) pd->rseq_area.cpu_id, RSEQ_CPU_ID_REGISTRATION_FAILED);
  40
  41   int ret = syscall (__NR_rseq, &pd->rseq_area, sizeof (pd->rseq_area),
  42                      0, RSEQ_SIG);
  43   if (ret == 0)
  44     {
  45       ret = syscall (__NR_rseq, &pd->rseq_area, sizeof (pd->rseq_area),
  46                      RSEQ_FLAG_UNREGISTER, RSEQ_SIG);
  47       TEST_COMPARE (ret, 0);
  48       pd->rseq_area.cpu_id = RSEQ_CPU_ID_REGISTRATION_FAILED;
  49     }
  50   else
  51     {
  52       TEST_VERIFY (errno != -EINVAL);
  53       TEST_VERIFY (errno != -EBUSY);
  54     }
  55 }
  56
  57 static void *
  58 thread_func (void *ignored)
  59 {
  60   check_rseq_disabled ();
  61   return NULL;
  62 }
  63
  64 static void
  65 proc_func (void *ignored)
  66 {
  67   check_rseq_disabled ();
  68 }
  69
  70 static int
  71 do_test (void)
  72 {
  73   puts ("info: checking main thread");
  74   check_rseq_disabled ();
  75
  76   puts ("info: checking main thread (2)");
  77   check_rseq_disabled ();
  78
  79   puts ("info: checking new thread");
  80   xpthread_join (xpthread_create (NULL, thread_func, NULL));
  81
  82   puts ("info: checking subprocess");
  83   support_isolate_in_subprocess (proc_func, NULL);
  84
  85   return 0;
  86 }
  87 #else /* !RSEQ_SIG */
  88 static int
  89 do_test (void)
  90 {
  91   FAIL_UNSUPPORTED ("glibc does not define RSEQ_SIG, skipping test");
  92 }
  93 #endif
  94
  95 #include <support/test-driver.c>