Whether to validate flags/options?

[xxchan]

from_bits_truncate() is used in some syscalls in linux-syscall and zircon-syscall, so it is possible that the input flag has an invalid bit set. Should this return Err? I'm not sure of the behavior of linux and zircon when this situation happens.

[wangrunji0408]

This should return Err(LxError::EINVAL) or Err(ZxError::INVALID_ARGS). And make sure that the bitflags contains all valid bits.

[xxchan]

This should return Err(LxError::EINVAL) or Err(ZxError::INVALID_ARGS).

OK, I can fix this.

bitflags contains all valid bits

What do you mean by this? Isn't that already ensured?

[wangrunji0408]

I'm not sure. Maybe need to check again...