Re: linux-next: build warnings after merge of the tip tree

Peter Zijlstra
2022-03-21T16:51:12Z

On Mon, Mar 21, 2022 at 12:45:51PM -0400, Steven Rostedt wrote:
> On Mon, 21 Mar 2022 17:40:32 +0100
> Peter Zijlstra <peterz@infradead.org> wrote:
>
> > func_B:
> > call __fentry__ /* push func_B */
> > ...
> > call __fexit__ /* pop 1 + tails */
> > ret
> >
> > func_A:
> > call __fentry__ /* push func_A */
> > ...
> > call __ftail__ /* mark func_A tail */
> > jmp func_B
> >
> > func_C:
> > call __fentry__ /* push func_C */
> > call func_A;
> > ...
> > call __fexit__ /* pop 1 + tails */
> > ret;
>
> This also assumes that we need to trace everything that is marked. I
> mentioned in another email, what do we do if we only trace funcA?

Like I said later on; if we inhibit tail-calls to notrace, this goes
away.