From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753647AbaCBP5O (ORCPT ); Sun, 2 Mar 2014 10:57:14 -0500 Received: from mx1.redhat.com ([209.132.183.28]:5131 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753070AbaCBP5K (ORCPT ); Sun, 2 Mar 2014 10:57:10 -0500 From: Jiri Olsa To: linux-kernel@vger.kernel.org Cc: Jiri Olsa , Peter Zijlstra , Paul Mackerras , Ingo Molnar , Arnaldo Carvalho de Melo , "H. Peter Anvin" , Vince Weaver , Steven Rostedt Subject: [PATCH 2/3] perf: Disallow user space stack dump for function trace event Date: Sun, 2 Mar 2014 16:56:39 +0100 Message-Id: <1393775800-13524-3-git-send-email-jolsa@redhat.com> In-Reply-To: <1393775800-13524-1-git-send-email-jolsa@redhat.com> References: <1393775800-13524-1-git-send-email-jolsa@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Disabling user space stack dump for function trace event. Recent issues with user space callchains processing within page fault handler tracing showed as Peter said 'there's just too much fail surface'. The user space stack dump is just another source of the this issue. Related list discussions: http://marc.info/?t=139302086500001&r=1&w=2 http://marc.info/?t=139301437300003&r=1&w=2 Suggested-by: Peter Zijlstra Signed-off-by: Jiri Olsa Cc: Peter Zijlstra Cc: Paul Mackerras Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Cc: H. Peter Anvin Cc: Vince Weaver Cc: Steven Rostedt --- kernel/trace/trace_event_perf.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index d5e01c3..c894614 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -42,6 +42,13 @@ static int perf_trace_event_perm(struct ftrace_event_call *tp_event, */ if (!p_event->attr.exclude_callchain_user) return -EINVAL; + + /* + * Same reason to disable user stack dump as for user space + * callchains above. + */ + if (p_event->attr.sample_type & PERF_SAMPLE_STACK_USER) + return -EINVAL; } /* No tracing, just counting, so no obvious leak */ -- 1.8.3.1