_COMPAT_NSIG_WORDS
(_COMPAT_NSIG_WORDS - 1) * sizeof(unsigned int));
BUILD_BUG_ON(_COMPAT_NSIG_WORDS != 2);
(_COMPAT_NSIG_WORDS - 1) * sizeof(unsigned int));
unsigned int extramask[_COMPAT_NSIG_WORDS - 1];
compat_sigset_word sig[_COMPAT_NSIG_WORDS];