[OpenAFS-devel] Re: Problem with IP address based ACL?

[Derrick J Brashear]

On Wed, 21 Jun 2006, Joe Buehler wrote:

> Jeffrey Altman wrote:
>
>> ubik_Call() does provide a prototype because it is used as a
>> pseudo-vararg function.
>>
>> afs_int32
>> ubik_Call(int (*aproc) (), struct ubik_client *aclient,
>>      afs_int32 aflags, long p1, long p2, long p3, long p4,
>>      long p5, long p6, long p7, long p8, long p9,
>>      long p10, long p11, long p12, long p13, long p14,
>>      long p15, long p16)
>>
>> But what happens when the parameters that are being passed into
>> ubik_Call for later use by 'aproc' do not have the same size as
>> a 'long'?  In that case the alignment of parameters on the stack
>
> This is perilous for other reasons.  On AIX, for example, my recollection
> is that the first 8 parameters of a given type (float or int) are passed
> in registers -- and floats and ints go into different registers.  If there
> are floats involved the above method of doing varargs may fail badly because
> the registers will get all confused.
>
> I would say that the faster this sort of thing gets removed, the better --
> it is based on ABI assumptions that are not valid for all machines.

I have a patch to kill it in testing now.

Derrick