Re: [PATCH v8] perf record: Fix unhandled POLLHUP on non_perf_event descriptors

[Arnaldo Carvalho de Melo <acme@kernel.org>]

On Tue, Sep 15, 2026 at 01:22:24PM -0700, Ian Rogers wrote:
> On Thu, Aug 20, 2026 at 3:00 PM Ian Rogers <irogers@google.com> wrote:
> >
> > On Thu, Aug 20, 2026 at 2:47 PM <sashiko-bot@kernel.org> wrote:
> > >
> > > > When processing POLLHUP on a non_perf_event control descriptor,
> > > > evlist__finalize_ctlfd() is invoked to finalize the setup, correctly
> > > > setting the core evlist's poll array file descriptor to -1. However,
> > > > this finalized teardown state is never propagated back to the
> > > > individual thread's local replica of the pollfd array.
> > > >
> > > > Consequently, on the next iteration of the main recording loop,
> > > > record__update_evlist_pollfd_from_thread() performs a strict
> > > > equivalence check between the core evlist's array and the thread's
> > > > localized poll array, detecting that the fd values no longer match.
> > > > This causes an immediate -EINVAL abort and a premature teardown.
> > > >
> > > > Fix the underlying logic within
> > > > record__update_evlist_pollfd_from_thread() to sustainably propagate
> > > > the finalized teardown statuses (-1) originating from the core evlist
> > > > back to the thread's localized poll structure. This correctly
> > > > maintains synchronization and entirely prevents the unhandled
> > > > index mismatch crashes.
> > > >
> > > > Additionally, add a unit test that explicitly validates that
> > > > fdarray__filter() preserves its invariants regarding
> > > > fdarray_flag__nonfilterable items to guard against regressions.
> > > >
> > > > Fixes: fb4751e79c45 ("perf record: Fix teardown hang on system-wide multi-threaded sessions")
> > > > Assisted-by: Gemini:gemini-3.1-pro
> > > > Signed-off-by: Ian Rogers <irogers@google.com>
> > >
> > > Sashiko has reviewed this patch and found no issues. It looks great!
> 
> Ping. Thanks,
> Ian

Thanks, applied to perf-tools-next, for v7.4.

- Arnaldo