From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1033998AbcIVRrx (ORCPT ); Thu, 22 Sep 2016 13:47:53 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:57652 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966610AbcIVRrs (ORCPT ); Thu, 22 Sep 2016 13:47:48 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yanqiu Zhang , Jiri Olsa , Peter Zijlstra , Vikas Shivappa , Tony Luck , Thomas Gleixner Subject: [PATCH 4.7 127/184] perf/x86/intel/cqm: Check cqm/mbm enabled state in event init Date: Thu, 22 Sep 2016 19:41:01 +0200 Message-Id: <20160922174054.155757488@linuxfoundation.org> X-Mailer: git-send-email 2.10.0 In-Reply-To: <20160922174048.653794923@linuxfoundation.org> References: <20160922174048.653794923@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiri Olsa commit 79d102cbfd2e9d94257fcc7c82807ef1cdf80322 upstream. Yanqiu Zhang reported kernel panic when using mbm event on system where CQM is detected but without mbm event support, like with perf: # perf stat -e 'intel_cqm/event=3/' -a BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 IP: [] update_sample+0xbc/0xe0 ... [] __intel_mbm_event_init+0x18/0x20 [] flush_smp_call_function_queue+0x7b/0x160 [] generic_smp_call_function_single_interrupt+0x13/0x60 [] smp_call_function_interrupt+0x27/0x40 [] call_function_interrupt+0x8c/0xa0 ... The reason is that we currently allow to init mbm event even if mbm support is not detected. Adding checks for both cqm and mbm events and support into cqm's event_init. Fixes: 33c3cc7acfd9 ("perf/x86/mbm: Add Intel Memory B/W Monitoring enumeration and init") Reported-by: Yanqiu Zhang Signed-off-by: Jiri Olsa Acked-by: Peter Zijlstra Cc: Vikas Shivappa Cc: Tony Luck Link: http://lkml.kernel.org/r/1473089407-21857-1-git-send-email-jolsa@kernel.org Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- arch/x86/events/intel/cqm.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/arch/x86/events/intel/cqm.c +++ b/arch/x86/events/intel/cqm.c @@ -458,6 +458,11 @@ static void __intel_cqm_event_count(void static void init_mbm_sample(u32 rmid, u32 evt_type); static void __intel_mbm_event_count(void *info); +static bool is_cqm_event(int e) +{ + return (e == QOS_L3_OCCUP_EVENT_ID); +} + static bool is_mbm_event(int e) { return (e >= QOS_MBM_TOTAL_EVENT_ID && e <= QOS_MBM_LOCAL_EVENT_ID); @@ -1366,6 +1371,10 @@ static int intel_cqm_event_init(struct p (event->attr.config > QOS_MBM_LOCAL_EVENT_ID)) return -EINVAL; + if ((is_cqm_event(event->attr.config) && !cqm_enabled) || + (is_mbm_event(event->attr.config) && !mbm_enabled)) + return -EINVAL; + /* unsupported modes and filters */ if (event->attr.exclude_user || event->attr.exclude_kernel ||