| /* |
| * Find out the size of kernel's sigset_t. |
| * |
| * Copyright (c) 2016-2017 Dmitry V. Levin <[email protected]> |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "tests.h" |
| #include <signal.h> |
| #include <unistd.h> |
| #include <asm/unistd.h> |
| |
| /* |
| * If the sigset size specified to rt_sigprocmask is not equal to the size |
| * of kernel's sigset_t, the kernel does not look at anything else and fails |
| * with EINVAL. |
| * |
| * Otherwise, if both pointers specified to rt_sigprocmask are NULL, |
| * the kernel just returns 0. |
| * |
| * This vaguely documented kernel feature can be used to probe |
| * the kernel and find out the size of kernel's sigset_t. |
| */ |
| |
| unsigned int |
| get_sigset_size(void) |
| { |
| static unsigned int set_size; |
| |
| if (!set_size) { |
| static const unsigned int big_size = 1024 / 8; |
| |
| for (set_size = big_size; set_size; set_size >>= 1) { |
| if (!syscall(__NR_rt_sigprocmask, SIG_SETMASK, |
| NULL, NULL, set_size)) |
| break; |
| } |
| |
| if (!set_size) |
| perror_msg_and_fail("rt_sigprocmask"); |
| } |
| |
| return set_size; |
| } |
