1 /* Tests of signal delivery on an alternate stack (_Exit).
2 Copyright (C) 2019-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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.
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.
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/>. */
19 #include <support/xsignal.h>
20 #include <support/support.h>
21 #include <support/check.h>
24 /* C2011 7.4.1.1p5 specifies that only the following operations are
25 guaranteed to be well-defined inside an asynchronous signal handler:
26 * any operation on a lock-free atomic object
27 * assigning a value to an object declared as volatile sig_atomic_t
28 * calling abort, _Exit, quick_exit, or signal
29 * signal may only be called with its first argument equal to the
30 number of the signal that caused the handler to be called
32 We use this list as a guideline for the set of operations that ought
33 also to be safe in a _synchronous_ signal delivered on an alternate
34 signal stack with only MINSIGSTKSZ bytes of space.
36 This test program tests calls to _Exit. */
38 #define EXPECTED_STATUS 3
43 _Exit (EXPECTED_STATUS);
49 void *sstk = xalloc_sigstack (0);
52 sa.sa_handler = handler;
53 sa.sa_flags = SA_RESTART | SA_ONSTACK;
54 sigfillset (&sa.sa_mask);
55 if (sigaction (SIGUSR1, &sa, 0))
56 FAIL_RET ("sigaction (SIGUSR1, handler): %m\n");
60 xfree_sigstack (sstk);
61 FAIL_RET ("test process was not terminated by _Exit in signal handler");
64 #include <support/test-driver.c>