1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright 2021 Jessica Clarke <jrtc27@FreeBSD.org> 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #pragma once 29 30 /* 31 * glibc's sys/wait.h and stdlib.h both define various wait-related constants, 32 * depending on __USE_XOPEN(2K8) and if the other header has been included. 33 * Since they each probe the other's include guard to determine that, there is 34 * a window between a header defining its include guard and checking for the 35 * other's within which, if the other is included for the first time, they both 36 * believe the other has already defined the relevant macros etc, and so 37 * neither ends up doing so. This was not previously hit, and is still not hit 38 * when using glibc normally (though seems extremely fragile). However, as of 39 * glibc 2.34, signal.h, included by sys/wait, includes a new bits/sigstksz, 40 * which in turn includes unistd.h (when _SC_SIGSTKSZ_SOURCE is defined, which 41 * is implied by _GNU_SOURCE), which we wrap and include stdlib.h from, 42 * creating the exact aforementioned situation that breaks. Thus, forcefully 43 * include stdlib.h first whenever sys/wait.h is as a workaround, since that 44 * way round still works. 45 */ 46 #include <stdlib.h> 47 #include_next <sys/wait.h> 48