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/*
* SPDX-License-Identifier: GPL-2.0-or-later
*
* test_sigstate - ...
*
* Written by Masatake YAMATO <yamato@redhat.com>
*/
#include "c.h"
#include <signal.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <err.h>
#define _U_ __attribute__((__unused__))
static enum {
HANDLER_NONE,
HANDLER_WRITE,
HANDLER_READ
} handler_state = HANDLER_NONE;
static int ERRNO;
static void handler(int signum _U_)
{
char c;
if (write(1, "USR1\n", 5) == -1) {
handler_state = HANDLER_WRITE;
goto out;
}
if (read(0, &c, 1) != -1)
_exit(0);
handler_state = HANDLER_READ;
out:
ERRNO = errno;
}
int main(int argc _U_, char **argv _U_)
{
sigset_t block_set;
sigemptyset(&block_set);
sigaddset(&block_set, SIGINT);
sigaddset(&block_set, SIGILL);
sigaddset(&block_set, SIGABRT);
sigaddset(&block_set, SIGFPE);
sigaddset(&block_set, SIGSEGV);
sigaddset(&block_set, SIGTERM);
if (sigprocmask(SIG_SETMASK, &block_set, NULL) == -1)
err(EXIT_FAILURE, "failed to mask signals");
raise(SIGINT);
raise(SIGILL);
#define sigignore(S) if (signal(S, SIG_IGN) == SIG_ERR) \
err(EXIT_FAILURE, "failed to make " #S "ignored")
sigignore(SIGHUP);
sigignore(SIGQUIT);
sigignore(SIGTRAP);
sigignore(SIGPIPE);
sigignore(SIGALRM);
signal(SIGINT, SIG_DFL);
signal(SIGBUS, SIG_DFL);
signal(SIGFPE, SIG_DFL);
signal(SIGSEGV, SIG_DFL);
signal(32, SIG_DFL);
signal(33, SIG_DFL);
if (signal(SIGUSR1, handler) == SIG_ERR)
err(EXIT_FAILURE, "failed to set a signal handler for SIGUSR1");
if (signal(SIGILL, handler) == SIG_ERR)
err(EXIT_FAILURE, "failed to set a signal handler for SIGILL");
printf("%d\n", getpid());
if (fflush(stdout) == EOF)
err(EXIT_FAILURE, "failed to flush stdout");
pause();
if (ERRNO == 0)
errx(EXIT_FAILURE, "caught an unexpected signal");
errno = ERRNO;
errx(EXIT_FAILURE, "failed in %s an ack from the command invoker",
handler_state == HANDLER_WRITE? "writing": "reading");
return 0; /* UNREACHABLE */
}
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