Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753262AbbBSRDk (ORCPT ); Thu, 19 Feb 2015 12:03:40 -0500 Received: from [198.137.202.9] ([198.137.202.9]:33097 "EHLO bombadil.infradead.org" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751568AbbBSRDi (ORCPT ); Thu, 19 Feb 2015 12:03:38 -0500 Date: Thu, 19 Feb 2015 18:03:11 +0100 From: Peter Zijlstra To: Vince Weaver Cc: linux-kernel@vger.kernel.org, Paul Mackerras , Ingo Molnar , Arnaldo Carvalho de Melo , Jiri Olsa , Steven Rostedt Subject: Re: perf: fuzzer gets CPU stuck in perf_callchain() Message-ID: <20150219170311.GH21418@twins.programming.kicks-ass.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2175 Lines: 58 On Thu, Feb 19, 2015 at 11:54:40AM -0500, Vince Weaver wrote: > [ 7938.802139] [] perf_tp_event+0xc4/0x210 > [ 7938.861174] [] perf_trace_lock+0x12a/0x160 > [ 7938.882197] [] lock_release+0x130/0x260 > [ 7938.888754] [] _raw_spin_unlock_irqrestore+0x24/0x40 > [ 7938.896510] [] do_send_sig_info+0x5d/0x80 > [ 7938.903240] [] send_sigio_to_task+0x12f/0x1a0 > [ 7938.923894] [] send_sigio+0xae/0x100 > [ 7938.930132] [] kill_fasync+0x97/0xf0 > [ 7938.942707] [] perf_event_wakeup+0xd4/0xf0 > [ 7938.956367] [] perf_pending_event+0x33/0x60 > [ 7938.963199] [] irq_work_run_list+0x4c/0x80 > [ 7938.969932] [] irq_work_run+0x18/0x40 > [ 7938.976212] [] smp_trace_irq_work_interrupt+0x3f/0xc0 > [ 7938.983957] [] trace_irq_work_interrupt+0x6d/0x80 Ah, it looks like the never ending irq_work.. Could you try this? --- kernel/events/core.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/kernel/events/core.c b/kernel/events/core.c index f04daabfd1cf..088e81ae43cb 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4574,6 +4574,13 @@ static void perf_pending_event(struct irq_work *entry) { struct perf_event *event = container_of(entry, struct perf_event, pending); + int rctx; + + rctx = perf_swevent_get_recursion_context(); + /* + * If we 'fail' here, that's OK, it means recursion is already disabled + * and we won't recurse 'further'. + */ if (event->pending_disable) { event->pending_disable = 0; @@ -4584,6 +4591,9 @@ static void perf_pending_event(struct irq_work *entry) event->pending_wakeup = 0; perf_event_wakeup(event); } + + if (rctx >= 0) + perf_swevent_put_recursion_context(rctx); } /* -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/