fusl/src/signal/sigprocmask.c

#include <signal.h>
#include <errno.h>

int sigprocmask(int how, const sigset_t* restrict set, sigset_t* restrict old) {
  int r = pthread_sigmask(how, set, old);
  if (!r)
    return r;
  errno = r;
  return -1;
}