On Tue, Oct 28, 2014 at 04:56:03PM +0000, Daniel Stone wrote:
Hi,
On 17 October 2014 01:36, Jiang, Fei fei.jiang@intel.com wrote:
Thanks for Emil's suggestion. You are right, we need make sure structure size aligned on 8 bytes, which is important for 32bit-64bit compatible case.
While you're at it, please don't use enum as a type inside ioctls, since the size can vary by compiler. Please use a uint32_t or whatever instead, assigning enum values to that.
Quick correction: You must use __u32 and friends, since using the standard C typesdef might collide with some program which defines them a different way. The double underscore ones are explicit ok per the C standard as private types for the system library. So they're the only ones we can use in userspace headers.
I've thought checkpatch would bitch about this if you get it wrong, now that we have the uapi split ... -Daniel