Re: [RFC][PATCH] rcu: Use typeof(p) instead of typeof(*p) *

[Linus Torvalds]

On Tue, Oct 5, 2021 at 12:40 PM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>
> I may try it, because exposing the structure I want to hide, is pulling out
> a lot of other crap with it :-p

One option is just "don't do rcu_access of a pointer that you're not
supposed to touch in a file that isn't supposed to touch it".

IOW, why are you doing that

     pid_list = rcu_dereference_sched(tr->function_pids);

in a place that isn't supposed to look at the pid_list in the first place?

Yeah, yeah, I see how you just pass it to trace_ignore_this_task() as
an argument, but maybe the real fix is to just pass that trace_array
pointer instead?

IOW, if you want to keep that structure private, maybe you really just
shouldn't have non-private users of it randomly doing RCU lookups of
it?

                  Linus