64-bit stat (or not) in 32-bit Fedora binaries

[Florian Weimer]

On 02/19/2013 04:32 PM, Jakub Jelinek wrote:
> On Tue, Feb 19, 2013 at 09:22:55AM -0600, Eric Sandeen wrote:
>>> (3) For my code that uses st_ino, I need to ensure this is never
>>> assigned to a 32 bit integer (eg. 'int', 'int32_t', 'long' on 32 bit, etc.)?
>>
>> To be safe I'd use it in an u64 type, I guess.  The *internal* kernel stat
>> structure uses u64:
>
> That would be wrong.  To store st_ino values, you should be using the ino_t
> type, like for file sizes/offsets (st_size, seeking, etc.) you should be
> using off_t.  Both of these types depend on _FILE_OFFSET_BITS macro.

You can't use ino_t and off_t in public header files because of that 
_FILE_OFFSET_BITS dependency.  At least in such header files, using 
explicit 64-bit types (uint64_t, presumably) is the way to go.

Admittedly, this has a certain yuck factor, but I don't see a way around 
that.

-- 
Florian Weimer / Red Hat Product Security Team