fusl/src/thread/pthread_sigmask.c

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

int pthread_sigmask(int how,
                    const sigset_t* restrict set,
                    sigset_t* restrict old) {
  int ret;
  if ((unsigned)how - SIG_BLOCK > 2U)
    return EINVAL;
  ret = -__syscall(SYS_rt_sigprocmask, how, set, old, _NSIG / 8);
  if (!ret && old) {
    if (sizeof old->__bits[0] == 8) {
      old->__bits[0] &= ~0x380000000ULL;
    } else {
      old->__bits[0] &= ~0x80000000UL;
      old->__bits[1] &= ~0x3UL;
    }
  }
  return ret;
}