Re: [PATCH 1/3] ext4: add EXT4_IOC_GETCRTIME ioctl

[Theodore Tso <tytso@mit.edu>]

On Wed, Aug 06, 2008 at 05:09:07PM +0800, Li Zefan wrote:
> +	case EXT4_IOC_GETCRTIME:
> +		return put_user(ei->i_crtime, (struct timespec __user *)arg);
> +

I'm worried about writing a struct timespec directly to user space,
because the kernel's idea of what is struct timespec might not be the
same as the userspace's understanding of struct timespec ---
specifically, because of the question of the width of time_t might be
different in the kernel and in userspace on different architectures.

I think we would be better off explicitly defining a structure, or
just returning the seconds and nanoseconds in explicit primitive
types.

Regards,

	     	 	       		 - Ted