1#include <signal.h>
 2#include <errno.h>
 3
 4int sigprocmask(int how, const sigset_t *restrict set, sigset_t *restrict old)
 5{
 6	int r = pthread_sigmask(how, set, old);
 7	if (!r) return r;
 8	errno = r;
 9	return -1;
10}