Re: [RESEND PATCH bpf-next v6 2/8] bpf: Introduce css_task open-coded iterator kfuncs

[Chuyi Zhou <zhouchuyi@bytedance.com>]

Hello,

在 2023/10/30 01:09, Guenter Roeck 写道:
> On Wed, Oct 18, 2023 at 02:17:40PM +0800, Chuyi Zhou wrote:
>> This patch adds kfuncs bpf_iter_css_task_{new,next,destroy} which allow
>> creation and manipulation of struct bpf_iter_css_task in open-coded
>> iterator style. These kfuncs actually wrapps css_task_iter_{start,next,
>> end}. BPF programs can use these kfuncs through bpf_for_each macro for
>> iteration of all tasks under a css.
>>
>> css_task_iter_*() would try to get the global spin-lock *css_set_lock*, so
>> the bpf side has to be careful in where it allows to use this iter.
>> Currently we only allow it in bpf_lsm and bpf iter-s.
>>
>> Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
>> Acked-by: Tejun Heo <tj@kernel.org>
> 
> With this patch in linux-next:
> 
> Building m68k:defconfig ... failed
> --------------
> Error log:
> kernel/bpf/task_iter.c: In function 'bpf_iter_css_task_new':
> kernel/bpf/task_iter.c:917:14: error: 'CSS_TASK_ITER_PROCS' undeclared (first use in this function)
>    917 |         case CSS_TASK_ITER_PROCS | CSS_TASK_ITER_THREADED:
>        |              ^~~~~~~~~~~~~~~~~~~
> kernel/bpf/task_iter.c:917:14: note: each undeclared identifier is reported only once for each function it appears in
> kernel/bpf/task_iter.c:917:36: error: 'CSS_TASK_ITER_THREADED' undeclared (first use in this function)
>    917 |         case CSS_TASK_ITER_PROCS | CSS_TASK_ITER_THREADED:
> 
> My apologies for the noise if this has already been reported and/or fixed.
> 
> Guenter

Here is the previous discussion link:
https://lore.kernel.org/lkml/20231020132749.1398012-1-arnd@kernel.org/

We can talk this issue on that maillist.

thanks.