bad_mode_bit
err |= bad_mode_bit(stbuf.st_mode, S_IRUSR, B_TRUE, rpath);
err |= bad_mode_bit(stbuf.st_mode, S_IWUSR, B_TRUE, rpath);
err |= bad_mode_bit(stbuf.st_mode, S_IXUSR, B_TRUE, rpath);
err |= bad_mode_bit(stbuf.st_mode, S_IRGRP, B_FALSE, rpath);
err |= bad_mode_bit(stbuf.st_mode, S_IWGRP, B_FALSE, rpath);
err |= bad_mode_bit(stbuf.st_mode, S_IXGRP, B_FALSE, rpath);
err |= bad_mode_bit(stbuf.st_mode, S_IROTH, B_FALSE, rpath);
err |= bad_mode_bit(stbuf.st_mode, S_IWOTH, B_FALSE, rpath);
err |= bad_mode_bit(stbuf.st_mode, S_IXOTH, B_FALSE, rpath);
err |= bad_mode_bit(stbuf.st_mode, S_IRUSR, B_TRUE, rppath);
err |= bad_mode_bit(stbuf.st_mode, S_IWUSR, B_TRUE, rppath);
err |= bad_mode_bit(stbuf.st_mode, S_IXUSR, B_TRUE, rppath);
err |= bad_mode_bit(stbuf.st_mode, S_IWGRP, B_FALSE, rppath);
err |= bad_mode_bit(stbuf.st_mode, S_IWOTH, B_FALSE, rppath);