#define _GNU_SOURCE
#include <stdio.h>
#include <signal.h>
#include <errno.h>
#include <sys/syscall.h>


#if 0

/* The sigprocmask syscall works correctly */
_syscall3(int, sigprocmask, int, how, const sigset_t *, set,
	sigset_t *, oldset);

#else

/* The rt_sigprocmask syscall currently fails */
_syscall4(int, rt_sigprocmask, int, how, const sigset_t *, set,
	sigset_t *, oldset, size_t, size);
int sigprocmask(int how, const sigset_t *set, sigset_t *oldset)
{
	return rt_sigprocmask(how, set, oldset, _NSIG/8);
}

#endif

int main(void)
{
	sigset_t set;
	sigset_t oset;
	int r;

	sigemptyset(&set);
	sigemptyset(&oset);

	/* Block no signals since set is empty.
	 * oset will be set to the app default. */
	errno = 0;
	r = sigprocmask(SIG_SETMASK, &set, &oset);
	if (r != 0) {
		printf("r=%d : %m\n", r);
	}

	/* Block no signals since set is empty.
	 * oset will now also be empty. */
	errno = 0;
	r = sigprocmask(SIG_SETMASK, &set, &oset);
	if (r != 0) {
		printf("r=%d : %m\n", r);
	}

	/* * SuSv3 says:
	 *	"The * argument how indicates the way in which the set is
	 *	changed, and the application shall ensure it consists of one
	 *	of [SIG_BLOCK, SIG_UNBLOCK, SIG_SETMASK] ... If sigprocmask()
	 *	fails, the thread's signal mask shall not be changed."
	 *
	 * Attempt to block SIGHUP with a bogus 'how'.  This should fail,
	 * and return EINVAL, and oset should should still be empty. */
	errno = 0;
	r = sigaddset(&set, SIGHUP);
	if (r != 0) {
		printf("r=%d : %m\n", r);
	}
	errno = 0;
	r = sigprocmask(0xdeadbeef, &set, &oset);
	if (r != 0) {
		printf("Expected failure: %m\n");
	}

	/* Query the value of oset.  It should still be empty */
	errno = 0;
	r = sigprocmask(SIG_SETMASK, (sigset_t *)0, &oset);
	if (r != 0) {
		printf("r=%d : %m\n", r);
	}

	/* But oset is not empty!  This is contrary to SuSv3! */
	if (sigismember(&oset, SIGHUP)==1) {
		printf("FAIL -- oset was changed when we supplied an invalid 'how'\n");
		return 1;
	} else {
		printf("PASS\n");
	}

	return 0;
}