Re: Build failure on PowerPC in pf

On Wed, Feb 26, 2014 at 1:20 PM, John-Mark Gurney <jmg_at_funkthat.com> wrote:
> Justin Hibbits wrote this message on Wed, Feb 26, 2014 at 11:12 -0800:
>> On Wed, Feb 26, 2014 at 10:32 AM, Justin Hibbits <jrh29_at_alumni.cwru.edu> wrote:
>> > Building on PowerPC I see the following failure:
>> >
>> > cc1: warnings being treated as errors
>> >
>> > /home/chmeee/freebsd/head/sys/modules/pf/../../netpfil/pf/pf_ioctl.c:
>> > In function 'pfioctl':
>> > /home/chmeee/freebsd/head/sys/modules/pf/../../netpfil/pf/pf_ioctl.c:1357:warning:
>> > cast to pointer from integer of different size [-Wint-to-pointer-cast]
>> > /home/chmeee/freebsd/head/sys/modules/pf/../../netpfil/pf/pf_ioctl.c:1359:warning:
>> > cast to pointer from integer of different size [-Wint-to-pointer-cast]
>> > /home/chmeee/freebsd/head/sys/modules/pf/../../netpfil/pf/pf_ioctl.c:1361:warning:
>> > cast to pointer from integer of different size [-Wint-to-pointer-cast]
>> >
>> > struct pf_rule has counter_u64_t entries, which are actually pointers
>> > to uint64_t's.  These pointers get assigned from the result of
>> > counter_u64_fetch(), which returns a uint64_t.  Looks to me like
>> > there's a bug in here, but I have no idea what to do to fix it.  And
>> > I'm surprised this hasn't been reported against other 32-bit
>> > architectures.
>>
>> Replying to myself, it looks like this was broken by r261882.
>
> This comment says it all:
> 1352    glebius         261882  /*
> 1353                    * XXXGL: this is what happens when internal kernel
> 1354                    * structures are used as ioctl API structures.
> 1355                    */
>
> So, one way could be to use a union for the states:
> union {
>         struct {
>                 counter_u64_t states_cur;
>                 counter_u64_t states_tot;
>                 counter_u64_t src_nodes;
>         } k;
>         struct {
>                 uint64_t states_cur;
>                 uint64_t states_tot;
>                 uint64_t src_nodes;
>         } u;
> } u;
>
> The other option is to cast through uintptr_t...
>
> Even though it'd make the code a bit more ugly, I'd vote for the union,
> since it's designed for what the code is trying to do...
>
> --
>   John-Mark Gurney                              Voice: +1 415 225 5579
>
>      "All that I will do, has been done, All that I have, has not."

Casting through uintptr_t eliminated the warning.  But, like you said,
the union is the better way to go.

- Justin