Re: [perf] perf_event_open() sometimes returning 0
From: Vince Weaver
Date: Thu Jan 02 2020 - 14:22:57 EST
On Thu, 2 Jan 2020, Vince Weaver wrote:
> so I was tracking down some odd behavior in the perf_fuzzer which turns
> out to be because perf_even_open() sometimes returns 0 (indicating a file
> descriptor of 0) even though as far as I can tell stdin is still open.
error is triggered if aux_sample_size has non-zero value.
seems to be this line in kernel/events/core.c:
if (perf_need_aux_event(event) && !perf_get_aux_event(event, group_leader))
goto err_locked;
(note, err is never set)
Vince